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1.
BMC Health Serv Res ; 24(1): 502, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654340

RESUMO

BACKGROUND: A new interprofessional model incorporating non-dispensing pharmacists in general practice teams can improve the quality of pharmaceutical care. However, results of the model are dependent on the context. Understanding when, why and how the model works may increase chances of successful broader implementation in other general practices. Earlier theories suggested that the results of the model are achieved by bringing pharmacotherapeutic knowledge into general practices. This mechanism may not be enough for successful implementation of the model. We wanted to understand better how establishing new interprofessional models in existing healthcare organisations takes place. METHODS: An interview study, with a realist informed evaluation was conducted. This qualitative study was part of the Pharmacotherapy Optimisation through Integration of a Non-dispensing pharmacist in primary care Teams (POINT) project. We invited the general practitioners of the 9 general practices who (had) worked closely with a non-dispensing pharmacist for an interview. Interview data were analysed through discussions about the coding with the research team where themes were developed over time. RESULTS: We interviewed 2 general practitioners in each general practice (18 interviews in total). In a context where general practitioners acknowledge the need for improvement and are willing to work with a non-dispensing pharmacist as a new team member, the following mechanisms are triggered. Non-dispensing pharmacists add new knowledge to current general practice. Through everyday talk (discursive actions) both general practitioners and non-dispensing pharmacists evolve in what they consider appropriate, legitimate and imaginable in their work situations. They align their professional identities. CONCLUSIONS: Not only the addition of new knowledge of non-dispensing pharmacist to the general practice team is crucial for the success of this interprofessional healthcare model, but also alignment of the general practitioners' and non-dispensing pharmacists' professional identities. This is essentially different from traditional pharmaceutical care models, in which pharmacists and GPs work in separate organisations. To induce the process of identity alignment, general practitioners need to acknowledge the need to improve the quality of pharmaceutical care interprofessionally. By acknowledging the aspect of interprofessionality, both general practitioners and non-dispensing pharmacists will explore and reflect on what they consider appropriate, legitimate and imaginable in carrying out their professional roles. TRIAL REGISTRATION: The POINT project was pre-registered in The Netherlands National Trial Register, with Trial registration number NTR-4389.


Assuntos
Medicina Geral , Clínicos Gerais , Relações Interprofissionais , Entrevistas como Assunto , Farmacêuticos , Pesquisa Qualitativa , Humanos , Clínicos Gerais/psicologia , Medicina Geral/organização & administração , Atitude do Pessoal de Saúde , Equipe de Assistência ao Paciente/organização & administração , Feminino , Masculino , Papel Profissional
2.
Nature ; 580(7803): 409-412, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32296172

RESUMO

Mycobacterium tuberculosis (Mtb) is an obligate human pathogen and the causative agent of tuberculosis1-3. Although Mtb can synthesize vitamin B12 (cobalamin) de novo, uptake of cobalamin has been linked to pathogenesis of tuberculosis2. Mtb does not encode any characterized cobalamin transporter4-6; however, the gene rv1819c was found to be essential for uptake of cobalamin1. This result is difficult to reconcile with the original annotation of Rv1819c as a protein implicated in the transport of antimicrobial peptides such as bleomycin7. In addition, uptake of cobalamin seems inconsistent with the amino acid sequence, which suggests that Rv1819c has a bacterial ATP-binding cassette (ABC)-exporter fold1. Here, we present structures of Rv1819c, which reveal that the protein indeed contains the ABC-exporter fold, as well as a large water-filled cavity of about 7,700 Å3, which enables the protein to transport the unrelated hydrophilic compounds bleomycin and cobalamin. On the basis of these structures, we propose that Rv1819c is a multi-solute transporter for hydrophilic molecules, analogous to the multidrug exporters of the ABC transporter family, which pump out structurally diverse hydrophobic compounds from cells8-11.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas de Bactérias/metabolismo , Bleomicina/metabolismo , Mycobacterium tuberculosis/metabolismo , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Transporte Biológico , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Mycobacterium tuberculosis/química , Mycobacterium tuberculosis/genética , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína
3.
Br J Clin Pharmacol ; 85(10): 2321-2331, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31240722

RESUMO

AIMS: To evaluate the effect of non-dispensing pharmacists (NDPs) integrated in general practice on medication-related hospitalisations, drug burden index and costs in patients at high risk of medication problems (being 65 years or older and using 5 or more chronic medications). METHODS: This was a multicentre, nonrandomised, controlled intervention study with pre-post comparison (2013 vs June 2014 to May 2015) in 25 general practices in the Netherlands, comparing NDP-led care (intervention) with 2 current pharmaceutical care models (usual care and usual care plus). In the intervention group, 10 specially trained NDPs were employed in general practices to take integral responsibility for the pharmaceutical care. They provided a broad range of medication therapy management services both on patient level (e.g. clinical medication review) and practice level (e.g. quality improvement projects). In the control groups, pharmaceutical care was provided as usual by general practitioners and community pharmacists, or as usual plus, when pharmacists were additionally trained in performing medication reviews. RESULTS: Overall, 822 medication-related hospitalisations were identified among 11 281 high-risk patients during the intervention period. After adjustment for clustering and potential confounders, the rate ratio of medication-related hospitalisations in the intervention group compared to usual care was 0.68 (95% confidence interval: 0.57-0.82) and 1.05 (95% confidence interval: 0.73-1.52) compared to usual care plus. No differences in drug burden index or costs were found. CONCLUSIONS: In general practices with an integrated NDP, the rate of medication-related hospitalisations is lower compared to usual care. No differences with usual care plus were found.


Assuntos
Hospitalização/estatística & dados numéricos , Conduta do Tratamento Medicamentoso/organização & administração , Assistência Farmacêutica/organização & administração , Farmacêuticos/organização & administração , Idoso , Idoso de 80 Anos ou mais , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Feminino , Medicina Geral/organização & administração , Humanos , Masculino , Países Baixos , Papel Profissional
4.
Nat Commun ; 9(1): 3038, 2018 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-30072686

RESUMO

Uptake of vitamin B12 is essential for many prokaryotes, but in most cases the membrane proteins involved are yet to be identified. We present the biochemical characterization and high-resolution crystal structure of BtuM, a predicted bacterial vitamin B12 uptake system. BtuM binds vitamin B12 in its base-off conformation, with a cysteine residue as axial ligand of the corrin cobalt ion. Spectroscopic analysis indicates that the unusual thiolate coordination allows for decyanation of vitamin B12. Chemical modification of the substrate is a property other characterized vitamin B12-transport proteins do not exhibit.


Assuntos
Proteínas de Bactérias/metabolismo , Cisteína/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Vitamina B 12/metabolismo , Proteínas de Bactérias/química , Biocatálise , Cristalografia por Raios X , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Cinética , Proteínas de Membrana Transportadoras/química , Modelos Moleculares , Thiobacillus/metabolismo , Vitamina B 12/farmacologia
5.
PLoS One ; 12(6): e0179156, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28650956

RESUMO

Kisspeptins (KPs) and their receptor (GPR54 or KiSS1R) play a key-role in regulation of the hypothalamic-pituitary-gonadal axis and are therefore interesting targets for therapeutic interventions in the field of reproductive endocrinology. As dogs show a rapid and robust LH response after the administration of KP10, they can serve as a good animal model for research concerning KP signaling. The aims of the present study were to test the antagonistic properties of KP analogs p234, p271, p354, and p356 in vitro, by determining the intracellular Ca2+ response of CHEM1 cells that stably express human GPR54, and to study the in vivo effects of these peptides on basal plasma LH concentration and the KP10-induced LH response in female dogs. Exposure of the CHEM1 cells to KP-10 resulted in a clear Ca2+ response. P234, p271, p354, and p356 did not prevent or lower the KP10-induced Ca2+ response. Moreover, the in vivo studies in the dogs showed that none of these supposed antagonists lowered the basal plasma LH concentration and none of the peptides lowered the KP10-induced LH response. In conclusion, p234, p271, p354, and p356 had no antagonistic effects in vitro nor any effect on basal and kisspeptin-stimulated plasma LH concentration in female dogs.


Assuntos
Cálcio/metabolismo , Kisspeptinas/farmacologia , Hormônio Luteinizante/sangue , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Animais , Cães , Feminino , Humanos , Ratos , Receptores de Kisspeptina-1
6.
Theriogenology ; 86(5): 1376-81, 2016 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-27242177

RESUMO

Determining the presence of functional gonadal tissue in dogs can be challenging, especially in bitches during anestrus or not known to have been ovariectomized, or in male dogs with nonscrotal testes. Furthermore, in male dogs treated with deslorelin, a slow-release GnRH agonist implant for reversible chemical castration, the verification of complete downregulation of the hypothalamic-pituitary-gonadal (HPG) axis can be difficult, especially if pretreatment parameters such as the size of the testes or prostate gland are not available. The aims of this study were to validate an immunoradiometric assay for measurement of FSH in canine urine, to determine if the urinary FSH to creatinine ratio can be used to verify the neuter status in bitches and male dogs, as an alternative to the plasma FSH concentration, and to determine if downregulation of the HPG axis is achieved in male dogs during deslorelin treatment. Recovery of added canine FSH and serial dilutions of urine reported that the immunoradiometric assay measures urinary FSH concentration accurately and with high precision. Plasma FSH concentrations (the mean of two samples, taken 40 minutes apart) and the urinary FSH to creatinine ratio were determined before gonadectomy and 140 days (median, range 121-225 days) and 206 days (median, range 158-294 days) after gonadectomy of 13 bitches and five male dogs, respectively, and in 13 male dogs before and 132 days (median, range 117-174 days) after administration of a deslorelin implant. In both bitches and male dogs, the plasma FSH concentration and the urinary FSH to creatinine ratio were significantly higher after gonadectomy, with no overlapping of their ranges. Receiver operating characteristic analysis of the urinary FSH to creatinine ratio revealed a cut-off value of 2.9 in bitches and 6.5 in males to verify the presence or absence of functional gonadal tissue. In male dogs treated with deslorelin, the plasma FSH concentrations and urinary FSH to creatinine ratios were significantly lower after administration of the implant, but their ranges overlapped. We conclude that the urinary FSH to creatinine ratio can be used to verify the neuter status of bitches and male dogs. However, it cannot be used for the assessment of complete downregulation of the HPG axis after administration of a deslorelin implant. The urinary FSH to creatinine ratio is preferable over the plasma FSH concentration because it involves only one sample that can be collected relatively easy and noninvasively.


Assuntos
Creatinina/urina , Hormônio Foliculoestimulante/urina , Histerectomia/veterinária , Ensaio Imunorradiométrico/veterinária , Orquiectomia/veterinária , Ovariectomia/veterinária , Animais , Creatinina/sangue , Cães , Feminino , Hormônio Foliculoestimulante/sangue , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
7.
Theriogenology ; 86(2): 589-95, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-27020879

RESUMO

Kisspeptin (KP) plays a key role in the regulation of the hypothalamic-pituitary-gonadal axis via the release of GnRH. As normal KP signaling is essential for reproductive function, it could be an interesting new target for therapeutic interventions, e.g., nonsurgical contraception in dogs. The aims of the present study were to investigate the effect of KP-10 administration on plasma LH concentration in different stages of the reproductive cycle and to investigate the suitability of p271 as KP antagonist in the bitch. Two groups of six adult Beagle bitches were used. In one group, plasma LH concentration was determined before (40 and 0 minutes) and 10, 20, 40, and 60 minutes after the intravenous administration of 0.5-µg/kg body weight (BW) canine KP-10. In the other group, the bitches received a continuous intravenous infusion with p271 (50 µg/kg BW/h) for 3 hours, and 0.5-µg/kg BW canine KP-10 was administered intravenously 2 hours after the start of the p271 infusion. Their plasma LH concentration was determined before (-40 and 0 minutes) and 30, 60, 90, 120, 130, 140, 160, and 180 minutes after the start of the p271 infusion. In both groups, the experiments were performed during the follicular phase, the first and second half of the luteal phase, and during anestrus. Canine KP-10 induced an increase of plasma LH concentration during all estrous cycle stages and anestrus. There was no difference in LH response between the two groups. The lowest LH response was seen during the follicular phase and the highest response during anestrus. The area under the curve (AUC) for LH and LH increment in the follicular phase were lower than those in anestrus. The AUC LH and LH increment in the first half of the luteal phase were lower than those in the second half of the luteal phase and anestrus. The AUC LH and LH increment in the second half of the luteal phase were not different from those in anestrus. Continuous administration of the antagonist p271 did not alter basal plasma LH concentration and could not prevent or lower the LH response to KP-10 in any of the cycle stages and anestrus. It can be concluded that the LH response to KP-10 is dependent on estrous cycle stage and that peripheral administrated p271 cannot be used as KP antagonist in the dog. This provides new insight in reproductive endocrinology of the bitch, which is important when KP signaling is considered for therapeutic interventions, such as for estrus induction or nonsurgical contraception in the bitch.


Assuntos
Cães/fisiologia , Ciclo Estral/efeitos dos fármacos , Kisspeptinas/antagonistas & inibidores , Hormônio Luteinizante/sangue , Animais , Ciclo Estral/fisiologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Kisspeptinas/farmacologia , Peptídeos/antagonistas & inibidores
8.
Res Social Adm Pharm ; 10(5): 731-40, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24661800

RESUMO

BACKGROUND: Medication review procedures have been developed in many countries to improve rational and safe medication use. The similarities, comprehensiveness, and effectiveness of these procedures has not been assessed, or compared. OBJECTIVE: The aim of this study was to explore medication review practices in European countries. METHODS: An online survey was sent to 32 European countries (all 28 European Union countries and 4 other European countries) by email to one person in each country known to be aware of medication review practices in their country in May 2011. The informants were identified through Pharmaceutical Group of European Union. To complement and validate the information received through Pharmaceutical Group of European Union, medication review experts involved in Pharmaceutical Care Network Europe were contacted. The survey assessed comprehensiveness of the medication review procedures classified according to 3 types in terms of settings; access to patient clinical information; patient involvement; availability of documentation and information; collaboration with the physician; quality control, and training required. RESULTS: Almost two thirds (64%) of the 25 European countries which responded (response rate 78%) indicated having at least one type of medication review procedure in their country. In the community setting prescription (type I) and adherence (type II) medication reviews were the most common (established in 9 and 11 countries, respectively). More comprehensive type III clinical medication reviews requiring access to clinical patient information were still rare, and just being established in 6 countries. CONCLUSIONS: Medication review procedures are becoming common in health care throughout Europe, however improving their comprehensiveness would require better access to patient information for those professionals conducting clinical medication reviews. In addition to benchmarking, the inventory can enhance cooperation between countries and stakeholders involved in medication review practice development nationally and internationally.


Assuntos
Reconciliação de Medicamentos , Coleta de Dados , Europa (Continente) , Humanos , Adesão à Medicação , Reconciliação de Medicamentos/métodos
9.
Int J Pharm Pract ; 22(2): 159-62, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23683068

RESUMO

OBJECTIVE: Worldwide pharmacists play an increasingly important role in pharmacovigilance. Lareb Intensive Monitoring (LIM) in the Netherlands is a new form of active pharmacovigilance where pharmacists play a key role. Patients using drugs which are monitored are identified in the pharmacy and invited to participate in the active monitoring. Not all invited patients participate. This study aimed to investigate non-response bias in LIM, as well as reasons for non-response in order to identify barriers to participation. METHODS: The study population consisted of patients who received a first dispensation of an antidiabetic drug monitored with LIM between 1 July 2010 and 28 February 2011. Possible non-response bias was investigated by comparing age, gender and the number of drugs used as co-medication. Reasons for non-response were investigated using a postal questionnaire. KEY FINDINGS: Respondents were on average 4.5 years younger than non-respondents and used less co-medication. There were no differences regarding gender. The main reason for non-response was that information in the pharmacy was lacking. CONCLUSION: Differences between respondents and non-respondents should be taken into account when analysing and generalising data collected through LIM, as this might contribute to non-response bias. The relatively high response to the postal questionnaire, together with the answers about reasons for non-response, show that patients are willing to participate in a web-based intensive monitoring system, when they are informed and invited in the pharmacy.


Assuntos
Monitoramento de Medicamentos/métodos , Pacientes , Farmacêuticos , Adulto , Sistemas de Notificação de Reações Adversas a Medicamentos , Fatores Etários , Idoso , Viés , Bases de Dados Factuais , Quimioterapia Combinada , Feminino , Humanos , Hipoglicemiantes/uso terapêutico , Masculino , Pessoa de Meia-Idade , Países Baixos , Farmacovigilância , Fatores Sexuais
10.
Int J Clin Pharm ; 36(2): 336-44, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24293335

RESUMO

BACKGROUND: Pharmacists can play an important role in identifying and instructing pulmonary patients on their inhalation techniques in their patient contacts when dispensing inhalation medication. Pharmacy dispensing data can be used to identify inappropriate drug use in asthma and chronic obstructive pulmonary disease (COPD) patients. Recent studies found beneficial effects of pharmacy care services in improving drug adherence of pulmonary patients. However, large-scale and rigorous evaluations on pharmacist-led interventions in community care settings to enhance evidence-based drug treatment in patients with asthma and COPD seems to be lacking and results from studies on pharmacist-led interventions for pharmacotherapy improvements are inconsistent. This study evaluated the effectiveness of pharmacist-led interventions on suboptimal drug use patterns with asthma or COPD medication with substantial numbers of pharmacies and patients involved. SETTING: A prospective cohort study in a group of community pharmacies (intervention group) with a matched control group of Dutch community pharmacies was conducted between May 2011 and February 2012. Algorithms on 19 potential problems with asthma or COPD medication in a national dispensing database were used to signal patients to pharmacists of the intervention group (IG). METHODS: IG pharmacists selected patients for comprehensive care by a structured program. Changes in problems were measured during 10 months in selected and all users of asthma and COPD medication of IG pharmacies and in compared to a control pharmacies (CG) without the structured program. Primary outcome was reduction of oral high dosage corticosteroids or antibiotics (HDT). Secondary outcomes were changes in the persistence of 19 potential problems in the IG compared to CG. RESULTS: In the 107 IG pharmacies, 3,757 patients were selected for comprehensive care from totally 102,497 asthma or COPD patients and compared with 105,507 patients from 105 CG pharmacies. The mean number of HDT decreased in selected IG patients by an additional 0.54 (95 % CI 0.21-0.86) HDT treatments. From the problems with specific COPD and asthma medication, all problems decreased additionally to the CG within the total asthma or COPD population from the IG. Within the selected IG population the following problems decreased additionally for obsolete medication by 35 % (95 % CI 6-54 %), contra-indicated medication by 61 % (95 % CI 38-75 %) and lower use of powder inhalers in elderly patients by 29 % (95 % CI 13-42 %). CONCLUSION: Community pharmacists actively providing comprehensive pharmacy care could improve effective treatment in asthma and COPD patients and thereby decrease the number of prescriptions for exacerbations for these patients.


Assuntos
Asma/tratamento farmacológico , Serviços Comunitários de Farmácia , Farmacêuticos , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
11.
Reprod Domest Anim ; 48(5): 840-3, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23565694

RESUMO

Subinvolution of placental sites (SIPS) is the major cause of persistent sanguineous vaginal discharge after parturition in the bitch. Spontaneous remission is common but may take several months, and hence, medical therapy to end the discharge is often requested. In this retrospective study, we evaluated the effect of treatment for SIPS with low oral doses of a progestagen. Nine bitches with SIPS, but otherwise clinically healthy, were found in the computer database of the Department of Clinical Sciences of Companion Animals. Seven of these bitches were treated with low oral doses of a progestagen (megestrol acetate, 0.1 mg/kg body weight (bw) once daily for the 1st week, then 0.05 mg/kg bw once daily for the 2nd week). The other two bitches were untreated. Treatment results were evaluated by a telephone questionnaire. Progestagen treatment was successful in all of the treated dogs; sanguineous vaginal discharge stopped within the treatment period. One of the two untreated dogs remained symptomatic until the next oestrus, approximately 120 days after parturition, and the other remained symptomatic until 6 weeks before the start of the next pro-oestrus, 270 days after parturition. No side effects of the progestagen treatment were observed. Subsequent gestations, parturitions and puerperal periods of 5 mated bitches were uneventful. One bitch did not become pregnant after mating. In conclusion, the results of this study indicate that oral administration of low doses of progestagen for 2 weeks is effective in stopping persistent sanguineous vaginal discharge in bitches with SIPS, with neither side effects nor reduced subsequent fertility.


Assuntos
Doenças do Cão/tratamento farmacológico , Acetato de Megestrol/uso terapêutico , Transtornos Puerperais/veterinária , Administração Oral , Animais , Antineoplásicos Hormonais/administração & dosagem , Antineoplásicos Hormonais/farmacologia , Antineoplásicos Hormonais/uso terapêutico , Doenças do Cão/patologia , Cães , Relação Dose-Resposta a Droga , Feminino , Acetato de Megestrol/administração & dosagem , Acetato de Megestrol/farmacologia , Parto , Período Pós-Parto , Gravidez , Transtornos Puerperais/tratamento farmacológico
12.
Theriogenology ; 78(7): 1618-26, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22980090

RESUMO

Normal sexual differentiation depends on completion of chromosomal sex determination, gonadal differentiation, and development of the phenotypic sex. An irregularity in any of these three steps can lead to a disorder in sexual development (DSD). We examined nine dogs with DSD by abdominal ultrasonography, laparotomy, histologic examination of the gonads, and reproductive tract, cytogenetic analysis, and mRNA expression of the SRY gene. We also determined the plasma concentrations of luteinizing hormone (LH), estradiol-17ß, and testosterone before and after administration of gonadotropin-releasing hormone (GnRH) and compared these results with those obtained in anestrous bitches and male control dogs. The gonads of three dogs with DSD contained both testicular and ovarian tissue, while in the other six only testicular tissue was found. Each of the dogs had a uterus. Based on gynecologic examination, cytogenetic analysis, and the histology of the gonads, seven of the nine dogs appeared to be XX sex reversals. Three of these were XX true hermaphrodites and four were XX males; the other two dogs had incomplete XY gonadal dysgenesis. All seven XX sex-reversed dogs were found to be negative for the SRY gene by polymerase chain reaction. The basal plasma luteinizing hormone (LH) concentration was significantly higher in dogs with DSD than in anestrous bitches but not significantly different from that in male dogs. The basal plasma LH concentration increased significantly after GnRH administration in all dogs with DSD. The basal plasma estradiol concentration was significantly higher in dogs with DSD than in anestrous bitches but not significantly different from that in male dogs. The basal plasma testosterone concentration was lower in dogs with DSD than in male dogs. In all dogs with DSD both the basal and GnRH-induced plasma testosterone concentrations were above the upper limit of their respective ranges in the anestrous bitches. In conclusion, the secretion of LH and estradiol in these dogs with DSD, all of which had testicular tissue in their gonads, was similar to that in male control dogs. These results indicate that the basal and/or GnRH-stimulated plasma testosterone concentration might be used to detect the presence of testicular tissue in dogs with DSD.


Assuntos
Transtornos do Desenvolvimento Sexual/veterinária , Doenças do Cão/fisiopatologia , Ovário/fisiopatologia , Hipófise/fisiopatologia , Testículo/fisiopatologia , Animais , Transtornos do Desenvolvimento Sexual/patologia , Transtornos do Desenvolvimento Sexual/fisiopatologia , Cães , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Genes sry/genética , Disgenesia Gonadal/veterinária , Hormônio Liberador de Gonadotropina , Hormônio Luteinizante/sangue , Masculino , Ovário/patologia , Transtornos Ovotesticulares do Desenvolvimento Sexual/veterinária , Progesterona/sangue , RNA Mensageiro/análise , Testículo/patologia , Testosterona/sangue
13.
Theriogenology ; 77(5): 967-78, 2012 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-22153274

RESUMO

GnRH-stimulation tests were performed in 14 female and 14 male client-owned dogs of several breeds, before and 4 to 5 mo after gonadectomy. The aim of the study was to obtain more insight into the pituitary-gonadal axis in intact and neutered dogs and to establish reference values. Basal plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations were increased significantly after gonadectomy in both bitches and male dogs. In both males and females ranges of the basal plasma FSH concentrations, before and after gonadectomy, did not overlap as opposed to the overlap in ranges of the basal plasma LH concentrations. Before gonadectomy basal plasma LH concentrations were lower and basal plasma FSH concentrations were higher in bitches than in male dogs. After gonadectomy these basal values did not differ significantly. GnRH administration before gonadectomy resulted in an increase in plasma LH and FSH concentrations in both genders. GnRH administration after gonadectomy produced an increase only in plasma LH concentrations in both genders, and a just significant increase in plasma FSH in castrated male dogs. GnRH administration before gonadectomy resulted in a significant increase in plasma testosterone concentration in both genders. In males ranges of basal and GnRH-stimulated plasma testosterone concentrations before and after gonadectomy did not overlap. Basal plasma estradiol concentrations were significantly higher in intact males than in castrated males and their ranges did not overlap. The basal estradiol concentrations in bitches before and after ovariectomy were not significantly different. At 120 min after GnRH administration, ranges of plasma estradiol concentration of intact and ovariectomized bitches no longer overlapped. In conclusion, basal plasma FSH concentration appears to be more reliable than basal plasma LH concentration for verification of neuter status in both male and female dogs. The basal plasma testosterone concentration appears to be reliable for verification of neuter status in male dogs. The plasma estradiol concentration at 120 min after GnRH administration can be used to discriminate between bitches with and without functional ovarian tissue.


Assuntos
Castração , Hormônio Liberador de Gonadotropina/farmacologia , Gônadas/efeitos dos fármacos , Hipófise/efeitos dos fármacos , Animais , Cães , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Gônadas/fisiologia , Hormônio Luteinizante/sangue , Masculino , Orquiectomia/veterinária , Ovariectomia/veterinária , Ovário/efeitos dos fármacos , Ovário/fisiologia , Hipófise/fisiologia , Testículo/efeitos dos fármacos , Testículo/fisiologia , Testosterona/sangue
14.
Reprod Domest Anim ; 47 Suppl 6: 313-7, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23279527

RESUMO

Progesterone exerts its effect by binding to specific progesterone receptors (PR) within the cell. In dogs and cats, no data are available on PR isoforms as found in other species. We therefore investigated the sequence of the PR gene and encoded protein in dogs and cats, the expression of PR isoforms in mammary tissue using Western blots and the presence of PR in mammary tissue using immunohistochemistry. Comparison of the amino acid sequence of the canine and feline PR with human PR revealed major differences in the PR-B-specific upstream segment (BUS). However, the essential activation function 3 (AF3) domain was intact in the cat but mutated in the dog. The DNA and ligand-binding domains were highly similar among the species. In cats with fibroadenomatous hyperplasia (FAH), high expression of PR mRNA together with growth hormone (GH), GH receptor (GHR) and IGF-I mRNA was found in comparison with feline mammary carcinomas. Immunohistochemical analysis showed strong nuclear as well as cytoplasmic staining for PR in FAH. Western blot analysis revealed expression of the PR-A and PR-B isoforms in the feline mammary gland. In canine mammary tissue, the most abundant PR staining was found in proliferative zones of the mammary gland. Western blot analyses showed mainly staining for PR-A with lower PR-B staining. It is concluded that in dogs and cats both PR isoforms are expressed. The role of mutations found in the canine PR-B is discussed.


Assuntos
Gatos/metabolismo , Cães/metabolismo , Glândulas Mamárias Animais/metabolismo , Receptores de Progesterona/metabolismo , Sequência de Aminoácidos , Animais , Feminino , Dados de Sequência Molecular , Isoformas de Proteínas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Progesterona/classificação , Especificidade da Espécie
15.
J Mol Biol ; 414(1): 75-85, 2011 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-21983341

RESUMO

The Escherichia coli peptide binding protein OppA is an essential component of the oligopeptide transporter Opp. Based on studies on its orthologue from Salmonella typhimurium, it has been proposed that OppA binds peptides between two and five amino acids long, with no apparent sequence selectivity. Here, we studied peptide binding to E. coli OppA directly and show that the protein has an unexpected preference for basic peptides. OppA was expressed in the periplasm, where it bound to available peptides. The protein was purified in complex with tightly bound peptides. The crystal structure (up to 2.0 Å) of OppA liganded with the peptides indicated that the protein has a preference for peptides containing a lysine. Mass spectrometry analysis of the bound peptides showed that peptides between two and five amino acids long bind to the protein and indeed hinted at a preference for positively charged peptides. The preference of OppA for peptides with basic residues, in particular lysines, was corroborated by binding studies with peptides of defined sequence using isothermal titration calorimetry and intrinsic protein fluorescence titration. The protein bound tripeptides and tetrapeptides containing positively charged residues with high affinity, whereas related peptides without lysines/arginines were bound with low affinity. A structure of OppA in an open conformation in the absence of ligands was also determined to 2.0 Å, revealing that the initial binding site displays a negative surface charge, consistent with the observed preference for positively charged peptides. Taken together, E. coli OppA appears to have a preference for basic peptides.


Assuntos
Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Lipoproteínas/química , Lipoproteínas/metabolismo , Oligopeptídeos/metabolismo , Sítios de Ligação , Transporte Biológico , Proteínas de Transporte/genética , Cristalografia por Raios X , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Immunoblotting , Lipoproteínas/genética , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Salmonella typhimurium/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Especificidade por Substrato
16.
Theriogenology ; 75(9): 1596-601, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21295830

RESUMO

The lack of scientific data concerning whether parturition in the queen proceeds normally or not may prevent veterinarians and cat owners from recognizing parturition problems in time. A questionnaire-based study of parturition in 197 queens was performed to determine several parameters of parturition and their influence on its progress. The mean length of gestation was 65.3 days (range 57 to 72 days) and it decreased with increasing litter size (P = 0.02). The median litter size was 4.5 kittens (range 1 to 9), with more males (53%) than females (46%) (P = 0.05). Sixty-nine percent of the kittens were born in anterior presentation and 31% in posterior presentation, indicating that either can be considered normal in the cat. Males were born in posterior position (34%) more often than females (26%) (P = 0.03). The mean birth weight was 98 g (range of 35 to 167 g) and decreased with increasing litter size (P < 0.01). Mean birth weight was higher in males and kittens born in posterior presentation (P < 0.01). Forty-four (5%) of the 887 kittens were stillborn. This was not correlated with the presentation at expulsion but stillborn kittens were more often female (P = 0.02) and weighed less than those born alive (P = 0.04). The median interkitten time was 30 min (range 2 to 343 min) and 95% were born within 100 min after expulsion of the preceding kitten. The interkitten time as a measure of the progress of parturition was not influenced by the kitten's gender, presentation at expulsion, birth weight, or stillbirth, or by the parity of the queen. The results of this study can be used to develop reference values for parturition parameters in the queen, both to determine whether a given parturition is abnormal and as the basis for a parturition protocol.


Assuntos
Gatos/fisiologia , Parto/fisiologia , Prenhez/fisiologia , Animais , Peso ao Nascer , Feminino , Tamanho da Ninhada de Vivíparos , Masculino , Gravidez , Valores de Referência , Razão de Masculinidade , Natimorto/veterinária , Fatores de Tempo
17.
Theriogenology ; 75(7): 1271-9, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21295836

RESUMO

Interference with the pregnancy-maintaining influence of progesterone is the basis of most methods for termination of unwanted pregnancy in dogs. The currently available methods are based on induction of luteolysis or blocking of the progesterone receptor. Inhibition of progesterone synthesis using a competitive inhibitor of 3ß-hydroxysteroid dehydrogenase (3ß-HSD) could be another strategy to terminate unwanted pregnancies. In this study we investigated the effects of the 3ß-HSD inhibitor trilostane on corpus luteum function in non-pregnant bitches. Trilostane was administered orally for seven consecutive days in either the pituitary-independent part of the luteal phase (PIP, start of treatment on D11 after ovulation, n = 6) or the pituitary-dependent part (PDP, start of treatment on D31 after ovulation, n = 6), in an oral dose of about 4.5 mg/kg bw, twice daily. Results were compared with those obtained in control bitches (n = 6). ACTH stimulation tests were performed to assess adrenocortical reserve capacity. Trilostane caused no apparent side effects and ACTH stimulation tests revealed good suppression of cortisol secretion. Trilostane also caused a significant decrease in plasma progesterone concentration. When it was stopped during PIP, progesterone secretion was completely restored and there was no difference in the length of the luteal phase between those dogs and control dogs (99 days, range 70-138 d and 99 d, range 60-112 d, respectively). When trilostane was stopped during PDP there was no post-treatment recovery of progesterone secretion and although the luteal phase tended to be shorter (66 d, range 41-101 d) the difference was not significant (P = 0.09). Plasma prolactin concentration did not increase after the trilostane-induced decrease in plasma progesterone. The interoestrous interval in dogs treated during PIP (234 d, range 175-269 d) or PDP (198 d, range 120-287 d) was not significantly shorter than the control interval (247 d, range 176-313 d). In conclusion, trilostane treatment was effective in decreasing plasma progesterone concentration in bitches during the luteal phase, but the dose regimen used in this study produced less clear-cut inhibition of ovarian steroidogenesis than have other strategies to decrease plasma progesterone concentration. Further studies are warranted to determine whether trilostane can be used to terminate unwanted pregnancy in the bitch without inducing adrenocortical insufficiency.


Assuntos
Di-Hidrotestosterona/análogos & derivados , Cães , Fase Luteal/efeitos dos fármacos , Progesterona/metabolismo , 17-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Córtex Suprarrenal/efeitos dos fármacos , Córtex Suprarrenal/metabolismo , Córtex Suprarrenal/fisiologia , Animais , Di-Hidrotestosterona/farmacologia , Inibidores Enzimáticos/farmacologia , Feminino , Fase Luteal/sangue , Fase Luteal/metabolismo , Fase Luteal/fisiologia , Ovulação/sangue , Ovulação/efeitos dos fármacos , Ovulação/metabolismo , Ovulação/fisiologia , Gravidez , Progesterona/sangue , Prolactina/sangue , Prolactina/metabolismo , Fatores de Tempo
18.
Theriogenology ; 75(4): 742-51, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21144564

RESUMO

It can be difficult to confirm the presence of remnant ovarian tissue (ROT) in bitches that are presumed to be ovariohysterectomised. A GnRH stimulation test can be used to distinguish ovariectomised bitches from those in anoestrus, but it is uncertain whether the GnRH-induced changes in plasma LH and oestradiol concentrations that occur in intact bitches also occur in ROT-bitches. We report here eighteen ROT-bitches and compare the results of GnRH stimulation tests with those of six ovariectomised and six bitches in anoestrus. The basal (n = 17) and/or GnRH-stimulated (n = 18) plasma oestradiol concentration was above the detection limit of the assay, i.e., < 7 pmol/l, in all ROT-bitches but below the detection limit in all ovariectomised bitches. Basal plasma LH concentration was significantly higher in ROT-bitches (4.1 ± 0.7 µg/L) than those in anoestrus (0.64 ± 0.04 µg/L), and significantly lower than in ovariectomised bitches (20.2 ± 3.6 µg/L). Basal plasma LH concentration was relatively high in bitches in which there was a long interval between ovariectomy and appearance of oestrus. GnRH administration resulted in a significant increase in plasma LH and oestradiol concentrations in ROT-bitches. The GnRH-induced increase and subsequent decline in plasma LH concentration were significantly less in ROT-bitches than in either ovariectomised bitches or those in anoestrus. The GnRH-induced increase in plasma oestradiol concentration was significantly smaller in ROT-bitches than in those in anoestrus. In conclusion, the results of this study demonstrate that in dogs ROT is associated with noticeable changes in the pituitary-ovarian axis and suggest that a GnRH stimulation test may be used to distinguish between completely ovariectomised bitches and those with ROT.


Assuntos
Cães/fisiologia , Ovário/patologia , Hipófise/fisiologia , Animais , Estradiol/sangue , Ciclo Estral/sangue , Feminino , Hormônio Liberador de Gonadotropina/farmacologia , Hormônio Luteinizante/sangue , Ovariectomia/veterinária , Ovário/diagnóstico por imagem , Ovário/cirurgia , Progesterona/sangue , Ultrassonografia
19.
Theriogenology ; 73(1): 11-9, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19818999

RESUMO

Information on the pituitary-ovarian axis in dogs with a granulosa cell tumor (GCT) is lacking. Therefore, we investigated the plasma concentrations of luteinizing hormone (LH) and estradiol before and after gonadotropin-releasing hormone (GnRH) administration in seven bitches with a functional GCT (GCT-total), of which three were intact (GCT-intact) and four had remnant ovarian tissue (GCT-ROT). The results of the GnRH stimulation test were compared with those in six anestrous and six ovariectomized bitches. The most noteworthy results were as follows. The basal plasma LH concentrations of the GCT-ROT bitches were higher (P<0.05) than those of the anestrous bitches. The increment in the plasma LH concentration after GnRH administration in the GCT-total bitches was lower (P<0.001) than the increments in both the anestrous and ovariectomized bitches. The basal plasma estradiol concentrations in the GCT-total bitches were higher (P<0.001) than those in the anestrous and ovariectomized bitches. In conclusion, the pituitary-ovarian axis is affected in bitches with a functional GCT and is characterized by relatively high plasma LH concentrations in GCT-ROT bitches and a subnormal LH response to GnRH stimulation in all GCT bitches compared with those in anestrous and ovariectomized bitches. The relatively high proportion of dogs with remnant ovarian tissue among the GCT bitches suggests a pathogenetic role for elevated gonadotropin secretion in the pathogenesis of GCT.


Assuntos
Doenças do Cão/metabolismo , Tumor de Células da Granulosa/veterinária , Neoplasias Ovarianas/veterinária , Ovário/metabolismo , Hipófise/metabolismo , Animais , Cães , Estradiol/sangue , Feminino , Hormônio Liberador de Gonadotropina/farmacologia , Tumor de Células da Granulosa/diagnóstico por imagem , Tumor de Células da Granulosa/metabolismo , Hormônio Luteinizante/sangue , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/metabolismo , Ovariectomia , Ovário/efeitos dos fármacos , Ovário/patologia , Hipófise/efeitos dos fármacos , Ultrassonografia
20.
Reprod Domest Anim ; 44(5): 751-6, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18992091

RESUMO

Normal mammalian sex differentiation takes place in three genetically controlled steps: chromosomal sex determination (XX or XY), gonadal differentiation and development of the phenotypic sex. Animals are considered to be sex reversed if chromosomal sex determination and gonadal development are not in agreement. In this report, sex reversal is described in a 1.5-year-old Podenco dog that was referred because of suspected recurrent growth of a previously removed os clitoridis in the vulva. With that exception the dog was phenotypically female, but had never been in oestrus and exhibited male behaviour. Abdominal ultrasonography showed a small tubular structure dorsal to the bladder, consistent with a uterus. An ovoid structure resembling a gonad was visible between the right kidney and inguinal canal. Plasma testosterone concentrations before and after GnRH administration indicated the presence of functional testicular tissue. Two testes, each with its epididymis and ductus deferens, and a complete bicornuate uterus were removed surgically. Cytogenetic analysis of peripheral blood lymphocytes showed a normal female karyotype (78, XX). These findings are consistent with the diagnosis of an XX male. PCR analysis of genomic DNA revealed that the SRY gene was absent. In summary, this report describes the first SRY-negative XX male Podenco dog with an almost complete female phenotype despite high basal and stimulated plasma testosterone concentrations. It is hypothesized that the clinical observations in this dog may have been caused by reduced and delayed Müllerian-inhibiting substance secretion and the absence of conversion of testosterone to dihydrotestosterone due to 5alpha-reductase deficiency.


Assuntos
Cães/genética , Diferenciação Sexual , Proteína da Região Y Determinante do Sexo/análise , Animais , DNA/análise , Transtornos do Desenvolvimento Sexual , Estradiol/sangue , Feminino , Genitália Feminina/anatomia & histologia , Genitália Feminina/diagnóstico por imagem , Hormônio Liberador de Gonadotropina/administração & dosagem , Hormônio Luteinizante/sangue , Masculino , Fenótipo , Reação em Cadeia da Polimerase , Processos de Determinação Sexual , Diferenciação Sexual/genética , Proteína da Região Y Determinante do Sexo/genética , Testículo/anatomia & histologia , Testículo/crescimento & desenvolvimento , Testosterona/sangue , Ultrassonografia
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