RESUMO
BACKGROUND: The first 90 of UNAIDS 90-90-90 targets to have 90% of the people living with HIV know their status is an important entry point to the HIV treatment cascade and care continuum, but evidence shows that there is a large gap between males and females in this regard. It is therefore important to understand barriers and facilitators of achieving the first 90 target. This study examined determinants of the first 90 target among females and males in order to inform strategies aimed at improving the HIV cascade in South Africa. METHODS: The data used in the analysis were obtained from a 2017 household-based cross-sectional nationally representative survey conducted using a multi-stage stratified cluster random sampling design. A series of hierarchical multiple logistic regression models were fitted to identify the determinants of the first 90 target by gender. RESULTS: Overall, 84.8% of HIV-positive individuals aged 15 years and older were aware of their HIV status. Females were significantly more aware of their HIV status compared to males (88.7% vs 78.2%, p < 0.001). Both females aged 25 to 49 years [aOR = 3.20 (95% CI 1.35-7.57), p = 0.008], and 50 years and older [aOR = 3.19 (95% CI 1.04-9.76), p = 0.042] and males aged 25 to 49 years [aOR = 3.00 (95% CI 1.13-7.97), p = 0.028], and 50 years and older [aOR = 7.25 (95% CI 2.07-25.36), p = 0.002] were significantly more likely to know their HIV status compared to those aged 15 to 19 years. Males with tertiary education level were significantly more likely to be aware of their HIV positive status [aOR = 75.24 (95% CI 9.07-624.26), p < 0.001] compared to those with no education or with primary level education. Females with secondary [aOR = 3.28 (95% CI 1.20-8.99), p = 0.021] and matric [aOR = 4.35 (95% CI 1.54-12.37), p = 0.006] educational levels were significantly more likely to be aware of their HIV positive status, compared to those with no education or with primary level education. CONCLUSION: Significant progress has been made with regards to reaching the UNAIDS first 90 target. In this context achieving the first 90 target is feasible but there is a need for additional interventions to reach the males especially youth including those with no education or low levels of education.
Assuntos
Infecções por HIV , Adolescente , Estudos Transversais , Características da Família , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Masculino , Prevalência , África do Sul/epidemiologiaRESUMO
BACKGROUND AND OBJECTIVES: Pathogen reduction technology using amustaline (S-303) was developed to reduce the risk of transfusion-transmitted infection and adverse effects of residual leucocytes. In this study, the viability of red blood cells (RBCs) prepared with a second-generation process and stored for 35 days was evaluated in two different blood centres. MATERIALS AND METHODS: In a single-blind, randomized, controlled, two-period crossover study (n = 42 healthy subjects), amustaline-treated (Test) or Control RBCs were prepared in random sequence and stored for 35 days. On day 35, an aliquot of 51 Cr/99m Tc radiolabeled RBCs was transfused. In a subgroup of 26 evaluable subjects, 24-h RBC post-transfusion recovery, mean life span, median life span (T50 ) and life span area under the curve (AUC) were analysed. RESULTS: The mean 24-h post-transfusion recovery of Test and Control RBCs was comparable (83·2 ± 5·2 and 84·9 ± 5·9%, respectively; P = 0·06) and consistent with the US Food and Drug Administration (FDA) criteria for acceptable RBC viability. There were differences in the T50 between Test and Control RBCs (33·5 and 39·7 days, respectively; P < 0·001), however, these were within published reference ranges of 28-35 days. The AUC (per cent surviving × days) for Test and Control RBCs was similar (22·6 and 23·1 per cent surviving cells × days, respectively; P > 0·05). Following infusion of Test RBCs, there were no clinically relevant abnormal laboratory values or adverse events. CONCLUSION: RBCs prepared using amustaline pathogen reduction meet the FDA criteria for post-transfusion recovery and are metabolically and physiologically appropriate for transfusion following 35 days of storage.
Assuntos
Acridinas/farmacologia , Preservação de Sangue , Eritrócitos/efeitos dos fármacos , Compostos de Mostarda Nitrogenada/farmacologia , Acridinas/química , Adulto , Idoso , Área Sob a Curva , Sobrevivência Celular/efeitos dos fármacos , Isótopos do Cromo/química , Estudos Cross-Over , Contagem de Eritrócitos , Transfusão de Eritrócitos/efeitos adversos , Eritrócitos/química , Eritrócitos/citologia , Eritrócitos/metabolismo , Feminino , Meia-Vida , Hematoma/etiologia , Humanos , Marcação por Isótopo , Masculino , Viabilidade Microbiana/efeitos dos fármacos , Pessoa de Meia-Idade , Compostos de Mostarda Nitrogenada/química , Curva ROC , Método Simples-Cego , Tecnécio/química , Fatores de Tempo , Inativação de Vírus/efeitos dos fármacos , Adulto JovemRESUMO
BACKGROUND: Human papillomavirus (HPV) vaccination is recommended for routine administration at ages 11-12 years. However, uptake is lower than for other vaccines that are also routinely recommended for adolescents (MCV4 and Tdap). Understanding parental perceptions of HPV vaccine compared with other vaccines may help to inform strategies to increase uptake. METHODS: Parents and caregivers (n = 45) of adolescents ages 10-18 years from a low-income, ethnic minority population participated in a qualitative study. Interviews were transcribed verbatim and coded for emergent themes. RESULTS: Many participants perceived the HPV vaccine to be similar to other routine vaccines. Noted similarities included the vaccines' ability to prevent disease, similar methods of administration and belief in health care providers' recommendation. Some parents noted the greater benefit of HPV vaccine in preventing cancer, which was viewed as a serious disease. Parents also noted the different mode of transmission (sexual) for HPV, which evoked mixed opinions. CONCLUSION: Overall, most participants viewed the HPV vaccine in a positive light and similar to other adolescent vaccines with the added benefit of cancer prevention. Strategies that treat all three vaccines equally such as presenting them similarly as a 'bundle' to parents or considering policy initiatives such as school entry requirements might help increase raise coverage for HPV vaccine.
Assuntos
Serviços de Saúde do Adolescente/organização & administração , Conhecimentos, Atitudes e Prática em Saúde , Promoção da Saúde/organização & administração , Programas de Imunização/organização & administração , Papillomaviridae/imunologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus , Pais/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Adolescente , Tomada de Decisões , Etnicidade/psicologia , Feminino , Humanos , Programas de Imunização/métodos , Masculino , Infecções por Papillomavirus/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Pesquisa Qualitativa , Estados Unidos/epidemiologia , VacinaçãoRESUMO
This case represents only the 15th reported incidence of IgG4-related disease (IgG4-RD) affecting the laryngopharynx, adding diagnostic and therapeutic data for this rare condition and helping to inform the future management of these patients. A 66-year-old man presented with airway symptoms, and investigations by otolaryngology, cardiology and respiratory teams did not provide a clear diagnosis. Repeat biopsies of the laryngopharynx eventually confirmed a clinicopathological diagnosis of IgG4-RD. Treatment with prednisolone and methotrexate was successful. When infective and malignant causes of adult stridor have been excluded, inflammatory causes should be considered. The diagnosis of IgG4-RD isolated to the laryngopharynx may be delayed when using the widely accepted American College of Rheumatology classification criteria because it excludes upper aerodigestive tract features. IgG4-RD isolated to the laryngopharynx is extremely rare. This means a multidisciplinary approach is vital in ensuring timely diagnosis and treatment. Better diagnostic criteria are also needed.
Assuntos
Doença Relacionada a Imunoglobulina G4 , Masculino , Adulto , Humanos , Estados Unidos , Idoso , Doença Relacionada a Imunoglobulina G4/diagnóstico , Hipofaringe , Sons Respiratórios/etiologia , Sons Respiratórios/diagnóstico , Imunoglobulina G , Diagnóstico DiferencialRESUMO
Non-islet cell tumour hypoglycaemia (NICTH) results from paraneoplastic insulin-like growth factor-II (IGF-II) secretion and its potent insulin-like effect. It causes recurrent, often severe, hypoglycaemic episodes, which is detrimental to quality of life. There is limited evidence regarding best supportive care in unresectable tumours. A 76-year-old woman presented with hypoglycaemic collapse. A new diagnosis of unresectable hepatocellular carcinoma (HCC) was made. The IGF-II:IGF-I ratio was 11.0, which confirmed NICTH. The octreoscan showed avid disease. The main problem was symptomatic nocturnal hypoglycaemia. Curative treatment options were not possible in this case and treatment focused on preventing symptomatic hypoglycaemia. Inpatient treatment was with high carbohydrate nasogastric (NG) feeds, prednisolone and somatostatin analogue (octreotide) infusion. Once stabilised, the patient was discharged with NG feeds, prednisolone and a long-acting somatostatin analogue (sandostatin). The patient received successful end-of-life care with her family as per her wishes, without requiring readmission. The treatments were well-tolerated and effective in preventing symptomatic hypoglycaemic episodes. The combination of high carbohydrate NG feed with prednisolone and somatostatin analogues was effective in preventing symptomatic hypoglycaemia. Somatostatin analogues had a useful steroid sparing role. Larger case series are warranted to clarify the management of NICTH patients with placebo-controlled studies to determine the role of somatostatin analogues.
Assuntos
Carcinoma Hepatocelular , Hipoglicemia , Neoplasias Hepáticas , Idoso , Carboidratos , Carcinoma Hepatocelular/tratamento farmacológico , Feminino , Glucocorticoides/uso terapêutico , Humanos , Hipoglicemia/induzido quimicamente , Hipoglicemia/patologia , Hipoglicemiantes , Fator de Crescimento Insulin-Like II , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/tratamento farmacológico , Octreotida , Cuidados Paliativos , Prednisolona/uso terapêutico , Qualidade de Vida , Somatostatina/uso terapêuticoRESUMO
Recent evidence on the distribution of desmosomal glycoprotein isoforms that shows their combined expression in individual desmosomes has strengthened the belief that the latter are involved in epithelial differentiation and morphogenesis. It has been shown that cellular interactions and protein kinase C can modulate the adhesive properties of desmosomes in epithelial cell sheets. Genetic studies indicate the involvement of desmosomal components in cancer and epidermal diseases.
Assuntos
Desmossomos/metabolismo , Transdução de Sinais/fisiologia , Animais , Cálcio/metabolismo , Adesão Celular , Diferenciação Celular , Epitélio/metabolismo , Glicoproteínas/classificação , Humanos , Neoplasias/etiologia , Dermatopatias/etiologiaRESUMO
A pathogen inactivation (PI) process has been developed using the frangible anchor linker effector (FRALE) compound S-303. A series of experiments were performed in whole blood (WB) to measure the level of viral and bacterial inactivation. The results showed that 0.2mM S-303 and 2mM glutathione (GSH) inactivated >6.5 logs of HIV, >5.7 logs of Bluetongue virus, >7.0 logs of Yersinia enterocolitica, 4.2 logs of Serratia marcescens, and 7.5 logs of Staphylococcus epidermidis. Recent development for S-303 is focused on optimization of the PI process for red blood cell concentrates (RBC). A series of studies in RBC showed that 0.2mM S-303 and 20mM GSH inactivated approximately 5 logs or greater of Y. enterocolitica, E. coli, S. marcescens, S. aureus, HIV, bovine viral diarrhoea virus, bluetongue virus and human adenovirus 5. In both applications of the S-303 process, in vitro parameters of RBC function and physiology were retained compared to conventional RBC. Results from these studies indicate that S-303 can be applicable for PI of RBC and WB.
Assuntos
Acridinas/farmacologia , Preservação de Sangue/métodos , Patógenos Transmitidos pelo Sangue , Sangue/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Compostos de Mostarda Nitrogenada/farmacologia , Alquilantes/farmacologia , Animais , Sangue/microbiologia , Sangue/virologia , Patógenos Transmitidos pelo Sangue/isolamento & purificação , Bovinos , Células Cultivadas , Contagem de Colônia Microbiana , Desinfetantes/farmacologia , Desinfecção/métodos , Eritrócitos/microbiologia , Eritrócitos/virologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Estudos de Viabilidade , Humanos , Análise por Pareamento , Controle de Qualidade , Staphylococcaceae/efeitos dos fármacos , Staphylococcaceae/fisiologia , Yersinia enterocolitica/efeitos dos fármacos , Yersinia enterocolitica/fisiologiaRESUMO
The British Association of Head and Neck Oncologists (BAHNO) hosts an annual meeting at which research from all specialties involved in the management of head and neck oncology is presented. We have analysed the rate of publication of the abstracts presented, and reviewed the finalised programmes from the meetings between 2009 and 2015. The 2014 meeting was excluded as it was a combined international meeting. Key terms were searched in PubMed and Google Scholar to identify publications in peer-reviewed journals. If none was identified, these platforms were searched for the authors' names. Published abstracts were excluded. Study and journal demographic data were extracted. A total of 363 abstracts were presented, including 75 oral, 271 poster, and 17 of unclear presentation method. The total publication rate was 31.1%, representing 46.7% of oral abstracts and 27.3% of poster presentations. The mean time to publication was 16.5 months. Research was published in 45 individual journals with a mean (range) impact factor of 2.559 (0.886-36.418). There was a trend towards an increasing number of presentations over time with a decreasing publication rate. However, there was no trend in mean impact factor by year. The publication rate of abstracts presented at the BAHNO annual meetings is comparable with that of other large otolaryngology and head and neck conferences. The mean impact factor has not previously been utilised within this field, but may prove a useful metric that enables monitoring of the quality of presented research and comparison of the impact of the conferences.
RESUMO
BACKGROUND: The intersection of violence exposure and mental health problems is a public health crisis for South African (SA) adolescents. Understanding the impact of community violence on adolescent mental health can inform future interventions. OBJECTIVES: To assess pathways between community violence exposure and internalising and externalising problems in SA adolescents receiving mental healthcare, and the roles of parent and peer relationships in these associations. METHODS: Participants (N=120 parent-adolescent pairs) were recruited from four mental health clinics in Western Cape Province to participate in a pilot test of a family-based HIV prevention study. Adolescents reported on their exposure to community violence, parental attachment, peer support of risk behaviour, and mental health. Parents reported on adolescents' internalising and externalising mental health problems. Participants received transport money (ZAR30 = USD3) and a shopping voucher or cash (ZAR50 = USD5) for their time. RESULTS: Adolescents were 12 - 18 years old (mean (standard deviation) 14.39 (1.82) years), 53% were male, and 67% and 33% reported black African and mixed-race ethnicity, respectively. Parents were 94% female and reported an average monthly income of ZAR3â 973 (USD397). Boys reported significantly higher rates of witnessing community violence than girls. Among boys, significant paths emerged from community violence and low parent attachment to externalising symptoms and from community violence to peer support of risky behaviour. For girls, the only significant path was from low parent attachment to peer support of risky behaviour. CONCLUSIONS: This cross-sectional study sheds new light on the possible pathways from witnessing community violence to mental health problems among SA adolescents. Identifying factors that drive and mitigate psychological distress in the context of persistent community violence is critical to SA's future and can inform the selection and delivery of appropriate and targeted evidence-based interventions.
Assuntos
Comportamento do Adolescente/psicologia , Transtornos Mentais/epidemiologia , Saúde Mental , Violência/psicologia , Adolescente , Saúde do Adolescente , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Relações Pais-Filho , Pais/psicologia , Grupo Associado , Projetos Piloto , Assunção de Riscos , Fatores Sexuais , África do SulRESUMO
Bladder symptoms in multiple sclerosis (MS) are common and distressing but also highly amenable to treatment. A meeting of stakeholders involved in patients' continence care, including neurologists, urologists, primary care, MS nurses and nursing groups was recently convened to formulate a UK consensus for management. National Institute for Health and Clinical Excellence (NICE) criteria were used for producing recommendations based on a review of the literature and expert opinion. It was agreed that in the majority of cases, successful management could be based on a simple algorithm which includes using reagent sticks to test for urine infection and measurement of the post micturition residual urine volume. This is in contrast with published guidelines from other countries which recommend cystometry. Throughout the course of their disease, patients should be offered appropriate management options for treatment of incontinence, the mainstay of which is antimuscarinic medications, in combination, if necessary, with clean intermittent self-catheterisation. The evidence for other measures, including physiotherapy, alternative strategies aimed at improving bladder emptying, other medications and detrusor injections of botulinum toxin A was reviewed. The management of urinary tract infections as well as the bladder problems as part of severe disability were discussed and recommendations agreed.
Assuntos
Esclerose Múltipla/complicações , Doenças da Bexiga Urinária/etiologia , Doenças da Bexiga Urinária/terapia , Adulto , Conferências de Consenso como Assunto , Ingestão de Líquidos , Humanos , Pessoa de Meia-Idade , Esclerose Múltipla/epidemiologia , Antagonistas Muscarínicos/uso terapêutico , Reino Unido/epidemiologia , Doenças da Bexiga Urinária/tratamento farmacológico , Doenças da Bexiga Urinária/epidemiologia , Doenças da Bexiga Urinária/cirurgia , Doenças da Bexiga Urinária/urina , Bexiga Urinária Hiperativa/etiologia , Bexiga Urinária Hiperativa/terapia , Infecções Urinárias/complicações , Infecções Urinárias/terapia , Transtornos Urinários/etiologia , Transtornos Urinários/terapia , Urodinâmica , Adulto JovemRESUMO
The sarcolemma of the smooth muscle cell displays two alternating structural domains in the electron microscope: densely-staining plaques that correspond to the adherens junctions and intervening uncoated regions which are rich in membrane invaginations, or caveolae. The adherens junctions serve as membrane anchorage sites for the actin cytoskeleton and are typically marked by antibodies to vinculin. We show here by immunofluorescence and immunoelectron microscopy that dystrophin is specifically localized in the caveolae-rich domains of the smooth muscle sarcolemma, together with the caveolae-associated molecule caveolin. Additional labeling experiments revealed that beta 1 integrin and fibronectin are confined to the adherens junctions, as indicated by their codistribution with vinculin and tensin. Laminin, on the other hand, is distributed around the entire cell perimeter. The sarcolemma of the smooth muscle cell is thus divided into two distinct domains, featuring different and mutually exclusive components. This simple bipartite domain organization contrasts with the more complex organization of the skeletal muscle sarcolemma: smooth muscle thus offers itself as a useful system for localizing, among other components, potential interacting partners of dystrophin.
Assuntos
Caveolinas , Distrofina/metabolismo , Músculo Liso/ultraestrutura , Sarcolema/ultraestrutura , Vinculina/metabolismo , Animais , Caveolina 1 , Compartimento Celular , Galinhas , Proteínas da Matriz Extracelular/metabolismo , Cobaias , Imuno-Histoquímica , Integrinas/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Musculares/metabolismo , Espectrina/metabolismoRESUMO
The desmosomal cadherin desmocollin (Dsc)1 is expressed in upper epidermis where strong adhesion is required. To investigate its role in vivo, we have genetically engineered mice with a targeted disruption in the Dsc1 gene. Soon after birth, null mice exhibit flaky skin and a striking punctate epidermal barrier defect. The epidermis is fragile, and acantholysis in the granular layer generates localized lesions, compromising skin barrier function. Neutrophils accumulate in the lesions and further degrade the tissue, causing sloughing (flaking) of lesional epidermis, but rapid wound healing prevents the formation of overt lesions. Null epidermis is hyperproliferative and overexpresses keratins 6 and 16, indicating abnormal differentiation. From 6 wk, null mice develop ulcerating lesions resembling chronic dermatitis. We speculate that ulceration occurs after acantholysis in the fragile epidermis because environmental insults are more stringent and wound healing is less rapid than in neonatal mice. This dermatitis is accompanied by localized hair loss associated with formation of utriculi and dermal cysts, denoting hair follicle degeneration. Possible resemblance of the lesions to human blistering diseases is discussed. These results show that Dsc1 is required for strong adhesion and barrier maintenance in epidermis and contributes to epidermal differentiation.
Assuntos
Epiderme/fisiologia , Epiderme/ultraestrutura , Glicoproteínas de Membrana/metabolismo , Envelhecimento , Alopecia/patologia , Animais , Antígenos CD/metabolismo , Caderinas/metabolismo , Diferenciação Celular , Divisão Celular , Dermatite/patologia , Desmocolinas , Desmossomos/química , Desmossomos/metabolismo , Epiderme/patologia , Pálpebras/patologia , Marcação de Genes , Imuno-Histoquímica , Integrina beta4 , Queratinas/metabolismo , Antígeno Ki-67/metabolismo , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Transgênicos , Fenótipo , Isoformas de Proteínas , Recombinação Genética , Dermatopatias/patologiaRESUMO
Nitrogen regulatory protein C (NtrC) contacts a bacterial RNA polymerase from distant enhancers by means of DNA loops and activates transcription by allowing polymerase to gain access to the template DNA strand. It was shown that NtrC from Salmonella typhimurium must build large oligomers to activate transcription. In contrast to eukaryotic enhancer-binding proteins, most of which must bind directly to DNA, some NtrC dimers were bound solely by protein-protein interactions. NtrC oligomers were visualized with scanning force microscopy. Evidence of their functional importance was provided by showing that some inactive non-DNA-binding and DNA-binding mutant forms of NtrC can cooperate to activate transcription.
Assuntos
Proteínas de Bactérias , DNA Bacteriano/metabolismo , Proteínas de Ligação a DNA/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Fator sigma/metabolismo , Transativadores , Fatores de Transcrição/metabolismo , Transcrição Gênica , Ativação Transcricional , Adenosina Trifosfatases/metabolismo , Proteínas de Ligação a DNA/química , Dimerização , Elementos Facilitadores Genéticos , Proteínas PII Reguladoras de Nitrogênio , Fosforilação , Regiões Promotoras Genéticas , RNA Polimerase Sigma 54 , Salmonella typhimurium/genética , Salmonella typhimurium/metabolismo , Fatores de Transcrição/químicaRESUMO
Bladder symptoms in multiple sclerosis (MS) are common and distressing but also highly amenable to treatment. A meeting of stakeholders involved in patients' continence care, including neurologists, urologists, primary care, MS nurses and nursing groups was recently convened to formulate a UK consensus for management. National Institute for Health and Clinical Excellence (NICE) criteria were used for producing recommendations based on a review of the literature and expert opinion. It was agreed that in the majority of cases, successful management could be based on a simple algorithm which includes using reagent sticks to test for urine infection and measurement of the post micturition residual urine volume. This is in contrast with published guidelines from other countries which recommend cystometry. Throughout the course of their disease, patients should be offered appropriate management options for treatment of incontinence, the mainstay of which is antimuscarinic medications, in combination, if necessary, with clean intermittent self-catheterisation. The evidence for other measures, including physiotherapy, alternative strategies aimed at improving bladder emptying, other medications and detrusor injections of botulinum toxin A was reviewed. The management of urinary tract infections as well as the bladder problems as part of severe disability were discussed and recommendations agreed.
Assuntos
Esclerose Múltipla/terapia , Bexiga Urinária Hiperativa/terapia , Incontinência Urinária/terapia , Infecções Urinárias/terapia , Feminino , Humanos , Masculino , Esclerose Múltipla/complicações , Esclerose Múltipla/fisiopatologia , Reino Unido , Bexiga Urinária Hiperativa/etiologia , Bexiga Urinária Hiperativa/fisiopatologia , Incontinência Urinária/etiologia , Incontinência Urinária/fisiopatologia , Infecções Urinárias/etiologia , Infecções Urinárias/fisiopatologia , Urodinâmica/fisiologiaRESUMO
A number of prokaryotic enhancer-binding proteins activate transcription by specialized forms of RNA polymerase. The enhancer-binding proteins catalyse isomerization of the initial complex formed between RNA polymerase and a promoter from the closed to the open state. To do so, one class of enhancer-binding proteins contacts its cognate polymerase by DNA loop formation but the other, which is represented by a single member, does not. Despite this difference, both classes of enhancer-binding proteins must hydrolyse ATP to catalyse open complex formation.
Assuntos
Bactérias/genética , Proteínas de Ligação a DNA/genética , Elementos Facilitadores Genéticos , Fatores de Transcrição , Sequência de Aminoácidos , Dados de Sequência MolecularRESUMO
Prostacyclin (PGI2) is a key mediator of pulmonary vasomotor tone during late gestation and in the newborn, and its production in whole lung increases during that period. We investigated the developmental regulation of PGI2 synthesis in ovine intrapulmonary artery (PA) segments from 110 to 115 d (F1) and 125 to 135 d gestation fetal lambs (F2, term = 144 d) and 1- and 4-wk-old newborn lambs (NB1 and NB2). Basal PGI2 rose fourfold from F1 to F2, fourfold from F2 to NB1, and twofold from NB1 to NB2. In all age groups 66-72% of PGI2 was derived from the endothelium. Similar fold increases in PGI2 were observed with maturation in intact and endothelium-denuded segments. In intact PA from F2, NB1, and NB2, basal PGI2 synthesis and synthesis maximally stimulated by bradykinin, A23187, or arachidonic acid rose with development in a comparable manner. In contrast, PGI2 synthesis stimulated by exogenous PGH2, the product of cyclooxygenase, was similar at all ages. Immunoblot analyses of PA from F2, NB1, and NB2 revealed that there is a sixfold maturational increase in cyclooxygenase-1 protein; the cyclooxygenase-2 isoform was not detectable. Cyclooxygenase-1 mRNA abundance in whole lung also rose with development. Thus, PGI2 synthesis in ovine PA endothelium and vascular smooth muscle increases markedly during late fetal and early newborn life; the increase is due to a rise in cyclooxygenase activity related to enhanced expression of cyclooxygenase-1. We conclude that there is developmental regulation of PA cyclooxygenase-1 gene expression, and that this may be critical to successful cardiopulmonary transition and function in the newborn.
Assuntos
Epoprostenol/biossíntese , Regulação Enzimológica da Expressão Gênica , Pulmão/enzimologia , Prostaglandina-Endoperóxido Sintases/biossíntese , Artéria Pulmonar/enzimologia , Envelhecimento/metabolismo , Animais , Animais Recém-Nascidos , Ácido Araquidônico/farmacologia , Bradicinina/farmacologia , Calcimicina/farmacologia , Embrião de Mamíferos/metabolismo , Endotélio Vascular/metabolismo , Técnicas In Vitro , Pulmão/irrigação sanguínea , Pulmão/crescimento & desenvolvimento , Artérias Mesentéricas/enzimologia , Músculo Liso Vascular/metabolismo , Prostaglandinas/biossíntese , Artéria Pulmonar/crescimento & desenvolvimento , OvinosRESUMO
Nitric oxide (NO) is an important mediator of physiologic and inflammatory processes in the lung. To better understand the role of NO in the airway, we examined constitutive NO synthase (NOS) gene expression and function in NCI-H441 human bronchiolar epithelial cells, which are believed to be of Clara cell lineage. NOS activity was detected by [3H]arginine to [3H]citrulline conversion (1,070 +/- 260 fmol/mg protein per minute); enzyme activity was inhibited 91% by EGTA, consistent with the expression of a calcium-dependent NOS isoform. Immunoblot analyses with antisera directed against neuronal, inducible, or endothelial NOS revealed expression solely of endothelial NOS protein. Immunocytochemistry for endothelial NOS revealed staining predominantly in the cell periphery, consistent with the association of this isoform with the cellular membrane. To definitively identify the NOS isoform expressed in H441 cells, NOS cDNA was obtained by degenerate PCR. Sequencing of the H441 NOS cDNA revealed 100% identity with human endothelial NOS at the amino acid level. Furthermore, the H441 NOS cDNA hybridized to a single 4.7-kb mRNA species in poly(A)+ RNA isolated from H441 cells, from rat, sheep, and pig lung, and from ovine endothelial cells, coinciding with the predicted size of 4.7 kb for endothelial NOS mRNA. Guanylyl cyclase activity in H441 cells, assessed by measuring cGMP accumulation, rose 6.6- and 5.4-fold with calcium-mediated activation of NOS by thapsigargin and A23187, respectively. These findings indicate that endothelial NOS is expressed in select bronchiolar epithelial cells, where it may have autocrine effects through activation of guanylyl cyclase. Based on these observations and the previous identification of endothelial NOS in a kidney epithelial cell line, it is postulated that endothelial NOS may be expressed in unique subsets of epithelial cells in a variety of organs, serving to modulate ion flux and/or secretory function.
Assuntos
Aminoácido Oxirredutases/biossíntese , Brônquios/enzimologia , Isoenzimas/biossíntese , Aminoácido Oxirredutases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Brônquios/patologia , Clonagem Molecular , Endotélio Vascular/enzimologia , Epitélio/enzimologia , Epitélio/patologia , Guanilato Ciclase/análise , Humanos , Immunoblotting , Imuno-Histoquímica , Isoenzimas/genética , Dados de Sequência Molecular , Óxido Nítrico Sintase , Reação em Cadeia da Polimerase , Ratos , Ovinos , Especificidade da Espécie , Células Tumorais CultivadasRESUMO
BACKGROUND: beta-Lactoglobulin (beta-Lg) is the major whey protein in the milk of ruminants and many other mammals. Its function is not known, but it undergoes at least two pH-dependent conformational changes which may be important. Bovine beta-Lg crystallizes in several different lattices, and medium-resolution structures of orthorhombic lattice Y and trigonal lattice Z have been published. Triclinic lattice X and lattice Z crystals grow at pH values either side of the pH at which one of the pH-induced conformational changes occurs. A full understanding of the structure is needed to help explain both the conformational changes and the different denaturation behaviour of the genetic variants. RESULTS: We have redetermined the structure of beta-Lg lattice Z at 3.0 A resolution by multiple isomorphous replacement and have partially refined it (R factor = 24.8%). Using the dimer from this lattice Z structure as a search model, the triclinic crystal form grown at pH 6.5 (lattice X) has been solved by molecular replacement. Refinement of lattice X at 1.8 A resolution gave an R factor of 18.1%. The structure we have determined differs from previously published structures in several ways. CONCLUSIONS: Incorrect threading of the sequence in the published structures of beta-Lg affects four of the nine beta strands. The basic lipocalin fold of the polypeptide chain is unchanged, however. The relative orientation of the monomers in the beta-Lg dimer differs in the two lattices. On raising the pH, there is a rotation of approximately 5 degrees, which breaks a number of intersubunit hydrogen bonds. It is not yet clear, however, why the stability of the structure should depend so heavily upon the external loop around residue 64 or the beta strand with the free thiol, each of which shows genetic variation.
Assuntos
Lactoglobulinas/química , Modelos Moleculares , Estrutura Secundária de Proteína , Sequência de Aminoácidos , Animais , Sítios de Ligação , Bovinos , Simulação por Computador , Cristalografia por Raios X/métodos , Dimerização , Ligação de Hidrogênio , Ligantes , Substâncias Macromoleculares , Dados de Sequência Molecular , Homologia de Sequência de AminoácidosRESUMO
BACKGROUND: We have previously reported that measurement of non-invasive blood pressure during caesarean section under spinal anaesthesia fails in over 50% of cases. We felt that errors would be less likely if blood pressure could be measured at the ankle as it is immobile during caesarean section. The purpose of our study was to determine whether blood pressure measurement at the ankle was equivalent to the arm. METHOD: Following ethical approval, informed consent was obtained from 30 women scheduled for elective caesarean section. Two non-invasive blood pressure cuffs, one on the upper arm and one on the ankle, were used to measure blood pressures at three timed intervals: before spinal insertion, before surgery and after delivery of the neonate. RESULTS: Using the method of Bland and Altman we found that there was only marginal agreement between the two methods. On eight out of 15 occasions where there was a greater than 20% fall in arm systolic blood pressure, this was not detected at the ankle. CONCLUSION: We cannot recommend the use of the ankle to measure blood pressure during caesarean section.
Assuntos
Pressão Sanguínea , Cesárea , Anestesia Obstétrica , Raquianestesia , Tornozelo , Braço , Determinação da Pressão Arterial , Feminino , Humanos , GravidezRESUMO
A three-dimensional profile method of detecting amino-acid sequences compatible with the tertiary structure of any protein has been applied to the lipocalin family of 8-stranded beta-barrels. Profiles derived from six well-resolved lipocalin crystal structures were used to search a comprehensive, non-redundant protein sequence database. Each profile identified a sub-group of lipocalin sequences although no single profile was sufficient to identify the whole family. The alpha-1-acid glycoprotein sub-family was not identified by any lipocalin profile, indicating that known sequence differences in otherwise well conserved regions of these proteins may be reflected in structural differences. The predicted similarity between the beta-lactoglobulin and alpha-2u-globulin structures was much more marked than the similarity between their sequences, and alpha-1-microglobulin sequences were found to be compatible with the structure of epididymal retinoic acid binding protein which has an additional long C-terminal helix. Proteins of unknown structure which were predicted to be compatible with the lipocalin fold include a human mucin. In cases where a large protein family of low overall sequence similarity contains a small number of known structures, this technique can be useful in determining or confirming subtle structural relationships between family members.