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1.
Tijdschr Psychiatr ; 66(1): 42-45, 2024.
Article in Dutch | MEDLINE | ID: mdl-38380487

ABSTRACT

A 29-year-old man developed priapism following the (re)administration of zuclopentixol. In the previous days, a significant amount of alcohol was consumed, presumably in combination with amphetamine and cannabis. Priapism is a rare but serious side effect of various psychoactive medications and recreational drugs, leading to permanent loss of erectile function if not treated in time. In this case the side effect was discovered in a late stage, at which curative treatment was no longer viable. A clear guideline for choosing an alternative antipsychotic agent is currently lacking, but an antipsychotic with low alfa-adrenergic affinity seems preferable. To prevent erectile disfunction following priapism, awareness of its severity is essential, for both doctor and patient.


Subject(s)
Antipsychotic Agents , Priapism , Male , Humans , Adult , Priapism/chemically induced , Priapism/drug therapy , Antipsychotic Agents/adverse effects , Clopenthixol
2.
Genomics ; 115(3): 110625, 2023 05.
Article in English | MEDLINE | ID: mdl-37068644

ABSTRACT

Precise regulation of transcription in gene expression is critical for all aspects of normal organism form, fitness, and function and even minor alterations in the level, location, and timing of gene expression can result in phenotypic variation within and between species including evolutionary innovations and human disease states. Eukaryotic transcription is regulated by a complex interplay of multiple factors working both at a physical and molecular levels influencing this process. In Saccharomyces cerevisiae, the TF with the greatest number of putative regulatory targets is the essential gene Repressor Activator Protein 1 (RAP1). While much is known about the roles of Rap1 in gene regulation and numerous cellular processes, the response of Rap1 target genes to systematic titration of RAP1 expression level remains unknown. To fill this knowledge gap, we used a strain with a tetracycline-titratable promoter replacing wild-type regulatory sequences of RAP1 to systematically reduce the expression level of RAP1 and followed this with RNA sequencing (RNA-seq) to measure genome-wide gene expression responses. Previous research indicated that Rap1 plays a significant regulatory role in particular groups of genes including telomere-proximal genes, homothallic mating (HM) loci, glycolytic genes, DNA repair genes, and ribosomal protein genes; therefore, we focused our analyses on these groups and downstream targets to determine how they respond to reductions in RAP1 expression level. Overall, despite being known as both an activator and as a repressor of its target genes, we found that Rap1 acts as an activator for more target genes than as a repressor. Additionally, we found that Rap1 functions as an activator of ribosomal protein genes and a repressor for HM loci genes consistent with predictions from the literature. Unexpectedly, we found that Rap1 functions as a repressor of glycolytic enzyme genes contrary to prior reports of it having the opposite effect. We also compared the expression of RAP1 to five different genes related to DNA repair pathway and found that decreasing RAP1 downregulated four of those five genes. Finally, we found no effect of RAP1 depletion on telomere-proximal genes despite its functioning to silence telomeric repeat-containing RNAs. Together our results enrich our understanding of this important transcriptional regulator.


Subject(s)
Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae , Humans , Saccharomyces cerevisiae/genetics , Transcription Factor AP-1/genetics , Saccharomyces cerevisiae Proteins/genetics , Shelterin Complex , Telomere-Binding Proteins/genetics , Telomere-Binding Proteins/metabolism , Ribosomal Proteins/genetics , Gene Expression , Gene Expression Regulation, Fungal , Fungal Proteins/genetics , Transcription Factors/metabolism
3.
Inorg Chem ; 61(19): 7217-7221, 2022 May 16.
Article in English | MEDLINE | ID: mdl-35510902

ABSTRACT

Here we show that the praseodymium N,N-dimethylaminodiboranate complex Pr(H3BNMe2BH3)3 and the 2,2,6,6-tetramethylheptane-3,5-dionate complex Pr(thd)3 can serve as volatile carriers for 225Ac. The actinium coordination complexes Ac(H3BNMe2BH3)3 and Ac(thd)3 are the likely species subliming with the carrier material. A sample of 225Ac-doped Pr(H3BNMe2BH3)3 was used to deposit amorphous 225Ac-doped praseodymium boride films on glass and Si(100) at 300 °C. The α emission spectra of the refractory films are well-resolved, suggesting that they could be used as radioactive implants for brachytherapy and related treatments.


Subject(s)
Brachytherapy , Praseodymium , Actinium , Boron Compounds
4.
Tijdschr Psychiatr ; 62(5): 340-350, 2020.
Article in Dutch | MEDLINE | ID: mdl-32484562

ABSTRACT

BACKGROUND: In the Netherlands, unemployed people in sick leave, can get sickness payment from the Employee Insurance Agency (UWV), so called 'vangnetters' (users of a safety net). They participated in a day-care program for people with psychological work-related complaints together with people in sick leave who were employed by an employer who were referred to a university psychiatric center (UCP).
AIM: Comparison of both groups on initial complaints and treatment outcome.
METHOD: A retrospective explorative study (during an 11-years period) comparing start and follow-up measurements by using questionnaires.
RESULTS: The UWV group (n = 111) differed from the UCP group (n = 254) at the start of the program: longer sickness leave, more severe initial complaints and a few other coping strategies. One year after finishing the program, 61% of the UWV group and 83% of the UCP group were in paid employment. People who were not in paid employment after a year already had more initial complaints compared to people who were back at work. The length of sickness leave was not a limiting factor for reintegration in work.
CONCLUSION: Differences in initial symptoms and coping strategies did not really lead to differences in perspective of reintegration in work. Cooperation with the UWV for employed as well as unemployed people in sick leave led to good treatment results.


Subject(s)
Employment , Sick Leave , Humans , Netherlands , Retrospective Studies , Surveys and Questionnaires
5.
J Affect Disord ; 265: 185-192, 2020 03 15.
Article in English | MEDLINE | ID: mdl-32090740

ABSTRACT

AIMS: Earlier studies show that participation in mind and body exercises (MBE) is cross-sectionally associated with high levels of depressive symptoms and antidepressants. This study investigates the longitudinal interrelationship between depressive symptoms, MBE and antidepressants. METHODS: 3269 men and 4318 women aged 24-74 years participated in the Swedish Longitudinal Occupational Survey of Health (SLOSH). Measures of MBE practice and depressive symptoms were drawn from the SLOSH questionnaire, data on prescription drugs were obtained from the Swedish Prescribed Drug Register. Structural Equation Modeling (SEM) was used to analyze temporal relationships. RESULTS: Both MBE practice and antidepressants in 2012 was associated with higher levels of depressive symptoms two years later. Depressive symptoms in turn were associated with higher levels of later MBE practice and antidepressants. These relationships seemed to be explained by confounding by indication and were of higher magnitude for antidepressants than for MBE. CONCLUSION: Overall, SEM analysis shows that MBE and antidepressant treatment were both bi-directionally associated with depressive symptoms over time. Part of the explanation is likely to be confounding by indication: those with symptoms of depression more likely to undertake treatment, and MBE alone may be more common among those with less severe depression. The results clarify some of our findings from earlier studies and give some important, new information on what people are doing to manage depressive symptoms on a societal level, regarding self-care, medication, and the combination of both.


Subject(s)
Antidepressive Agents , Depression , Adult , Aged , Antidepressive Agents/therapeutic use , Depression/epidemiology , Exercise , Female , Humans , Longitudinal Studies , Male , Middle Aged , Sweden/epidemiology , Young Adult
6.
J Autism Dev Disord ; 50(8): 2973-2986, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32052317

ABSTRACT

We compared the presence of autistic and comorbid psychopathology and functional impairments in young adults who received a clinical diagnosis of Pervasive Developmental Disorders Not Otherwise Specified or Asperger's Disorder during childhood to that of a referred comparison group. While the Autism Spectrum Disorder group on average scored higher on a dimensional ASD self- and other-report measure than clinical controls, the majority did not exceed the ASD cutoff according to the Autism Diagnostic Observation Schedule. Part of the individuals with an ASD diagnosis in their youth no longer show behaviors that underscribe a clinical ASD diagnosis in adulthood, but have subtle difficulties in social functioning and a vulnerability for a range of other psychiatric disorders.


Subject(s)
Asperger Syndrome/epidemiology , Autism Spectrum Disorder/epidemiology , Autism Spectrum Disorder/psychology , Adolescent , Adult , Asperger Syndrome/diagnosis , Autism Spectrum Disorder/diagnosis , Child , Comorbidity , Female , Humans , Male , Mental Disorders , Young Adult
7.
Appl Radiat Isot ; 140: 18-23, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29936271

ABSTRACT

This work presents a complete scheme for the selective separation of actinium and radium isotopes from bulk 232Th target material, in a process that may be applied in a separation scheme for the production of 225Ac by proton spallation on thorium. Thorium metal is dissolved in sulfuric acid with small amounts of HF. Actinium and radium are retained on cation exchange resin from the sulfate medium, while neutral and anionic thorium sulfate complexes are rejected. Following rinsing steps to remove residual thorium, actinium and radium are recovered from the cation exchange resin using 5 M HNO3. Further separations of actinium via extraction chromatography with UTEVA and DGA resins yield actinium in >92% yield, while providing additional decontamination from thorium and other spallation byproducts. The radium fraction can be further processed following ingrowth of 225Ac from 225Ra to produce additional 225Ac free from any potential 227Ac impurity.

8.
Scand J Prim Health Care ; 35(3): 286-292, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28768444

ABSTRACT

OBJECTIVE: A validated measure to gather patient feedback on physicians' empathy is not available in Swedish. The objective for this study was to examine the psychometric characteristics of a Swedish version of the Consultation and Relational Empathy (CARE) measure (widely used in English). DESIGN, SETTING AND PATIENTS: The CARE measure was translated into Swedish and tested on 554 unselected patients visiting physicians in two primary care clinics in northwestern Stockholm, Sweden. MAIN OUTCOME MEASURES: Adequate translation, as well as reliability and validity of the Swedish CARE measure. RESULTS: The Swedish CARE measure seemed to demonstrate high acceptability and face validity when consulting a physician. The mean CARE score 41.5 (SD 8.9) over all 10 item was not significantly influenced by seasonality, age or gender. Scores were somewhat negatively distributed, but corrected item-total correlations were high (0.86-0.91) suggesting homogeneity. Internal reliability was very high (Cronbach's alpha 0.975). Factor analysis implied a one-dimensional structure with factor loadings between 0.89 and 0.93. CONCLUSIONS: The Swedish CARE measure appears to be psychometrically valid and reliable enough in physicians.


Subject(s)
Empathy , Physician-Patient Relations , Surveys and Questionnaires/standards , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Psychometrics , Referral and Consultation , Reproducibility of Results , Sweden , Translating , Translations , Young Adult
9.
Ann Oncol ; 28(2): 400-407, 2017 02 01.
Article in English | MEDLINE | ID: mdl-27831506

ABSTRACT

Background: The purpose of our study was to characterize the causes of death among cancer patients as a function of objectives: (i) calendar year, (ii) patient age, and (iii) time after diagnosis. Patients and methods: US death certificate data in Surveillance, Epidemiology, and End Results Stat 8.2.1 were used to categorize cancer patient death as being due to index-cancer, nonindex-cancer, and noncancer cause from 1973 to 2012. In addition, data were characterized with standardized mortality ratios (SMRs), which provide the relative risk of death compared with all persons. Results: The greatest relative decrease in index-cancer death (generally from > 60% to < 30%) was among those with cancers of the testis, kidney, bladder, endometrium, breast, cervix, prostate, ovary, anus, colorectum, melanoma, and lymphoma. Index-cancer deaths were stable (typically >40%) among patients with cancers of the liver, pancreas, esophagus, and lung, and brain. Noncancer causes of death were highest in patients with cancers of the colorectum, bladder, kidney, endometrium, breast, prostate, testis; >40% of deaths from heart disease. The highest SMRs were from nonbacterial infections, particularly among <50-year olds (e.g. SMR >1,000 for lymphomas, P < 0.001). The highest SMRs were typically within the first year after cancer diagnosis (SMRs 10-10,000, P < 0.001). Prostate cancer patients had increasing SMRs from Alzheimer's disease, as did testicular patients from suicide. Conclusion: The risk of death from index- and nonindex-cancers varies widely among primary sites. Risk of noncancer deaths now surpasses that of cancer deaths, particularly for young patients in the year after diagnosis.


Subject(s)
Heart Diseases/mortality , Neoplasms/mortality , Cause of Death , Follow-Up Studies , Humans , Risk Factors , SEER Program , Time Factors , United States/epidemiology
11.
Autism ; 19(7): 842-9, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26088060

ABSTRACT

While various screening instruments for autism spectrum disorders are widely used in diagnostic assessments, their psychometric properties have not been simultaneously evaluated in the outpatient setting where these instruments are used most. In this study, we tested the Ritvo Autism Asperger Diagnostic Scale-Revised and two short versions of the Autism-Spectrum Quotient, the AQ-28 and AQ-10, in 210 patients referred for autism spectrum disorder assessment and in 63 controls. Of the 210 patients, 139 received an autism spectrum disorder diagnosis and 71 received another psychiatric diagnosis. The positive predictive values indicate that these tests correctly identified autism spectrum disorder patients in almost 80% of the referred cases. However, the negative predictive values suggest that only half of the referred patients without autism spectrum disorder were correctly identified. The sensitivity and specificity of each of these instruments were much lower than the values reported in the literature. In this study, the sensitivity of the Ritvo Autism Asperger Diagnostic Scale-Revised was the highest (73%), and the Autism-Spectrum Quotient short forms had the highest specificity (70% and 72%). Based on the similar area under the curve values, there is no clear preference for any of the three instruments. None of these instruments have sufficient validity to reliably predict a diagnosis of autism spectrum disorder in outpatient settings.


Subject(s)
Autism Spectrum Disorder/diagnosis , Adolescent , Adult , Autism Spectrum Disorder/psychology , Female , Humans , Male , Middle Aged , Reproducibility of Results , Self Report , Surveys and Questionnaires , Young Adult
12.
Brachytherapy ; 14(3): 316-21, 2015.
Article in English | MEDLINE | ID: mdl-25454576

ABSTRACT

PURPOSE: To determine whether computed tomography/magnetic resonance imaging-based day 0 (d0) dosimetry is a meaningful predictor of day 21 (d21) dosimetry in low-dose-rate brachytherapy for localized prostate cancer. METHODS AND MATERIALS: The study population consisted of 277 men with localized (T1-2 N0 M0), low-/intermediate-risk prostate cancer treated with low-dose-rate brachytherapy. Computed tomography/magnetic resonance imaging fusion was used for postimplant dosimetry at d0 and d21. Logistic regression was used to construct receiver operating characteristic curves for achieving each constraint at d21, based on d0 D90 and V100, and Youden's index was used to evaluate cutpoints. Freedom from biochemical failure (FBCF) was estimated with the Kaplan-Meier method. RESULTS: The median d0 D90 increased from 133 to 150 Gy at d21, and median d0 V100 increased from 87% to 91%. For achieving the D90 constraint at d21, the optimal cut-point for d0 D90 was 135 Gy, with 84% of these patients maintaining a d21 D90 > 145 Gy. For achieving the D90 constraint at d21, the optimal cut-point for d0 V100 was 87%, with 83% of these patients maintained a d21 V100 > 90%. There was no improvement in FBCF in patients with a d0 D90 > 135 Gy or D90 > 145 Gy. Similarly, there was no improvement in FBCF in patients with a d0 V100 > 87% or V100 > 90%. CONCLUSIONS: Meeting dosimetric constraints on d0 does not obviate d21 dosimetric analysis. Constraints used for dose prescriptions on d0 are not the ideal predictors of d21 dosimetry.


Subject(s)
Brachytherapy/methods , Prostatic Neoplasms/radiotherapy , Quality Assurance, Health Care , Radiometry/standards , Adult , Aged , Aged, 80 and over , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/pathology , Radiotherapy Dosage , Tomography, X-Ray Computed
13.
Dalton Trans ; 44(2): 515-21, 2015 Jan 14.
Article in English | MEDLINE | ID: mdl-25310364

ABSTRACT

The synthesis, stoichiometry, and structural characterization of a homoleptic, cationic europium(III) complex with three neutral tetraalkyldiglycolamide ligands are reported. The tri(bismuth tetrachloride)tris(N,N,N',N'-tetra-n-octyldiglycolamide)Eu salt, [Eu(TODGA)3][(BiCl4)3] obtained from methanol was examined by Eu L3-edge X-ray absorption spectroscopy (XAS) to reveal an inner-sphere coordination of Eu(3+) that arises from 9 O atoms and two next-nearest coordination spheres that arise from 6 carbon atoms each. A structural model is proposed in which each TODGA ligand with its O=Ca-Cb-O-Cb-Ca=O backbone acts as a tridentate O donor, where the two carbonyl O atoms and the one ether O atom bond to Eu(3+). Given the structural rigidity of the tridentate coordination motif in [Eu(TODGA)3](3+) with six 5-membered chelate rings, the six Eu-Ca and six Eu-Cb interactions are readily resolved in the EXAFS (extended X-ray absorption fine structure) spectrum. The three charge balancing [BiCl4](-) anions are beyond the cationic [Eu(TODGA)3](3+) cluster in an outer sphere environment that is too distant to be detected by XAS. Despite their sizeable length and propensity for entanglement, the four n-octyl groups of each TODGA (for a total of twelve) do not perturb the Eu(3+) coordination environment over that seen from previously reported single-crystal structures of tripositive lanthanide (Ln(3+)) complexes with tetraalkyldiglycolamide ligands (of the same 1:3 metal-to-ligand ratio stoichiometry) but having shorter i-propyl and i-butyl groups. The present results set the foundation for understanding advanced solvent extraction processes for the separation of the minor, tripositive actinides (Am, Cm) from the Ln(3+) ions in terms of the local structure of Eu(3+) in a solid state coordination complex with TODGA.

14.
Infection ; 41(5): 991-7, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23653428

ABSTRACT

PURPOSE: Colistin is increasingly used as the last-resort treatment option against infections caused by multidrug-resistant (MDR) Gram-negative pathogens, but its nephrotoxicity is of concern, especially in severely ill patients. The aim of this study was to analyze the toxicity of colistin therapy in adults and children with hematological malignancies (HM) and hematopoietic stem cell transplantation (HSCT) recipients. METHODS: Data on HSCT recipients and HM patients, treated with intravenous colistin (2.5-5 mg/kg/day in children and 3-6 million international units (IU) in adults, adjusted to renal function) during the period 2008-2011 in our center, were retrospectively collected and analyzed. Nephrotoxicity was defined according to the RIFLE criteria (Risk, Injury, Failure, Loss, and End-stage kidney disease). RESULTS: Twenty-nine children and adults received 38 courses of intravenous colistin (2.5-5 mg/kg/day in children and 3-6 × 10(6) IU in adults, adjusted to renal function) [allogeneic HSCT (22 courses) and HM (16 courses)] for 3-28 days (median 10 days) for empirical therapy for nosocomial clinical sepsis (28) or local infection (6), and bacteremia with MDR Gram-negative rods (4). Nephrotoxicity was observed at the end of 4 (10.5%) courses. In 32 (84%) courses, nephrotoxic medications were concomitantly administered. Two patients had convulsions, probably unrelated to colistin. Seven patients (18%) died while on colistin therapy. No death was attributed to an adverse effect of colistin. CONCLUSIONS: Treatment with intravenous colistin, with dosage adjusted to renal function, was relatively safe for HM/HSCT patients, even with concomitantly administered nephrotoxic medications. Concern about nephrotoxicity should not justify a delay in initiating empirical colistin treatment in situations where infection with MDR Gram-negative rods is likely.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/adverse effects , Colistin/administration & dosage , Colistin/adverse effects , Gram-Negative Bacterial Infections/drug therapy , Hematologic Neoplasms/microbiology , Hematopoietic Stem Cell Transplantation , Adolescent , Adult , Aged , Bacteremia/drug therapy , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Retrospective Studies , Treatment Outcome
15.
Pediatr Blood Cancer ; 60(9): E85-7, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23589280

ABSTRACT

X-linked lymphoproliferative syndrome (XLP) is caused by mutations in SH2D1A, and is associated with overwhelming infectious mononucleosis, aplastic anemia, hypogammaglobulinemia, and B-cell lymphomas. However, the frequency of SH2D1A mutations in males who present with B NHL is unknown. Five cases of XLP were diagnosed among 158 males presenting with B NHL (approximately 3.2%). Four of the patients had two episodes of B NHL and one had a single episode of B NHL followed by aggressive infectious mononucleosis. Prospective screening for XLP in males with B-cell lymphoma at the time of initial diagnosis should be considered.


Subject(s)
Intracellular Signaling Peptides and Proteins/genetics , Lymphoproliferative Disorders/genetics , Mutation , Registries , Follow-Up Studies , Humans , Lymphoma, Large B-Cell, Diffuse , Lymphoproliferative Disorders/diagnosis , Lymphoproliferative Disorders/pathology , Lymphoproliferative Disorders/therapy , Male , Retrospective Studies , Signaling Lymphocytic Activation Molecule Associated Protein
17.
Bone Marrow Transplant ; 47(11): 1448-54, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22426752

ABSTRACT

Fifty-eight consecutive children with high-risk malignancies were treated with CY, and targeted topotecan followed by autologous hematopoietic cell transplantation (AHCT) in a phase I/II Institutional Review Board-approved study. Twelve participants enrolled in phase I; 5 received dose level 1 of topotecan 3 mg/m(2) per day, with subsequent doses targeted to total systemic exposure of 100±20 ng h/mL and CY 750 mg/m(2) per day. Seven participants received dose level 2. CY dose escalation to 1 g/m(2) per day was considered excessively toxic; one died from irreversible veno-occlusive disease and two experienced reversible hepatotoxicity. These adverse events halted further dose escalation. A total of 46 participants were enrolled in phase II; results are on the 51 participants who received therapy at dose level 1, the maximum tolerated dose. Diagnoses included neuroblastoma (26), sarcoma (9), lymphoma (8), brain tumors (5), Wilms (2) and retinoblastoma (1). Twenty participants (39.3%) were in CR1 at enrollment; median age was 5.1 years. Most common non-hematological grade III-IV toxicity was gastrointestinal (n=37). Neutrophil and platelet engraftment occurred at a median of 15 and 24 days, respectively. Twenty-six (51%) participants remain alive at a median of 6.4 years after AHCT. CY 3.75 g/m(2), and targeted topotecan followed by AHCT are feasible and produce acceptable toxicity in children with high-risk malignancies.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Hematopoietic Stem Cell Transplantation/methods , Neoplasms/drug therapy , Neoplasms/surgery , Adolescent , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Child , Child, Preschool , Combined Modality Therapy , Cyclophosphamide/administration & dosage , Cyclophosphamide/adverse effects , Humans , Risk Factors , Survival Rate , Topoisomerase I Inhibitors/administration & dosage , Topoisomerase I Inhibitors/adverse effects , Topotecan/administration & dosage , Topotecan/adverse effects , Transplantation, Autologous
18.
Health Phys ; 101(2): 176-9, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21709506

ABSTRACT

Rapid methods for the isolation and analysis of individual actinides (Th, U, Pu, Am/Cm) and Sr, Tc and Po from small volumes of raw urine have been developed. The methods involve acidification of the sample and the addition of aluminum nitrate or aluminum chloride salting-out agent prior to isolation of the desired analyte using a tandem combination of prefilter material and extraction chromatographic resin. The method has been applied to the separation of individual analytes from spiked urine samples. Analytes were recovered in high yield and radionuclide purity with separation times as low as 30 min. The chemistry employed is compatible with automation on the ARSIIe instrument.


Subject(s)
Radiation Monitoring/methods , Radioisotopes/isolation & purification , Urinalysis/methods , Actinoid Series Elements/isolation & purification , Actinoid Series Elements/urine , Aluminum Chloride , Aluminum Compounds/chemistry , Automation/methods , Chlorides/chemistry , Chromatography/methods , Humans , Limit of Detection , Nitrates/chemistry , Polonium/isolation & purification , Polonium/urine , Radioisotopes/urine , Resins, Synthetic/chemistry , Scintillation Counting/methods , Strontium/isolation & purification , Strontium/urine , Technetium/isolation & purification , Technetium/urine , Time Factors
19.
J Vet Pharmacol Ther ; 34(5): 487-93, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21198678

ABSTRACT

Beta-lactam antimicrobials, commonly used in both veterinary and human medicine, generally present short biologic half-lives, whereas their activity is enhanced as pathogen exposure is prolonged. These properties necessitate multiple-dose regimens of standard dosage forms, thereby hampering pet owner adherence, frequently resulting in therapeutic failure. This study presents a novel controlled-release gastroretentive oral drug delivery system for beta-lactams with which single-dose administration provides an effective antimicrobial course, optimizing pharmacokinetic (PK)-pharmacodynamic (PD) profiles, minimizing adverse effects and emergence of antimicrobial resistance and facilitating adherence. Our prototype sustained-delivery swelling-tablet (SDST), based on a degradable hydrophilic polymeric matrix, was designed to enable continuous input of these drugs to their absorption sites over several days. Several SDST formulations of the beta-lactam amoxicillin were evaluated in in vitro dissolution studies. Two formulations were selected for further in vivo canine studies, for determination of gastric retention and PK-PD profiling. Prolonged gastric retention times maintaining allowed for maintained effective drug concentrations against many clinically relevant pathogens for more than 48 h for one formulation and more than 5 days for the other. Both SDST formulations offer significant advantages over standard immediate-release therapy in achieving PK-PD goals and enhancing adherence. The prototypical formulations represent a novel platform which may be modified to meet various clinical requirements.


Subject(s)
Absorbable Implants/veterinary , Amoxicillin/administration & dosage , Amoxicillin/pharmacokinetics , Goats/blood , Amoxicillin/blood , Animals , Area Under Curve , Delayed-Action Preparations , Goats/metabolism , Half-Life
20.
J Vet Pharmacol Ther ; 34(5): 494-8, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21198679

ABSTRACT

Dosage forms of antimicrobials play a critical role in facilitating the attainment of pharmacokinetic-pharmacodynamic (PK-PD) targets as well as adherence in both veterinary and human medicine. The purpose of this study was to develop and evaluate a controlled-release subcutaneous amoxicillin implant for single-dose therapy of large ruminants such as goats, sheep, and deer. The degradable implant, designed to attain PK-PD targets following single administration, was evaluated for amoxicillin release rate and time-concentration profile. In vitro release studies demonstrated constant-rate release of approximately 40% of amoxicillin content within 96 h. In an in vivo study in goats, serving as a model for target animals, a serum concentration of approximately 0.4 mg/L was achieved within 8 h of implant insertion and maintained for >6 days. In comparison, in control goats given a standard single intramuscular amoxicillin dose of 15 mg/kg, amoxicillin peaked at 1.2 mg/L after 1 h, rapidly dropping to below detection level at 8 h. These results suggest that the proposed implant offers a unique modality for animal caregivers to conveniently administer a full antimicrobial course following a single dose of an efficient PK-PD-optimized dosage form. Furthermore, modifications of implant composition may allow for tailoring of its characteristics to various PK, PD, microbiological, and clinical requirements.


Subject(s)
Absorbable Implants/veterinary , Amoxicillin/administration & dosage , Amoxicillin/pharmacokinetics , Goats/blood , Animals , Delayed-Action Preparations , Goats/metabolism
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