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1.
Nat Commun ; 13(1): 570, 2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35091572

RESUMO

Hall effect and quantum oscillation measurements on high temperature cuprate superconductors show that underdoped compositions have small Fermi surface pockets whereas when heavily overdoped, a single much larger pocket is found. The origin of this change in electronic structure has been unclear, but may be related to the high temperature superconductivity. Here we show that the clean overdoped single-layer cuprate Tl2Ba2CuO6+δ (Tl2201) displays CDW order with a remarkably long correlation length ξ ≈ 200 Å which disappears above a hole doping of pCDW ≈ 0.265. We show that the evolution of the electronic properties of Tl2201 as the doping is lowered may be explained by a Fermi surface reconstruction which accompanies the emergence of the CDW below pCDW. Our results demonstrate importance of CDW correlations in understanding the electronic properties of overdoped cuprates.

2.
Hong Kong Med J ; 25(5): 356-362, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31619577

RESUMO

INTRODUCTION: Total ischaemic time should be shortened as much as possible in patients with ST-segment elevation myocardial infarction (STEMI). This study evaluated whether prehospital 12-lead electrocardiogram (ECG) could shorten system delay in STEMI management. METHODS: From November 2015 to November 2017, 15 ambulances equipped with X Series Monitor/ Defibrillator (Zoll Medical Corporation) were used in the catchment area of Queen Mary Hospital, Hong Kong. Prehospital ECG was performed for patients with chest pain; the data were tele-transmitted to attending emergency physicians at the Accident and Emergency Department (AED) for rapid assessment. Data from patients with STEMI who were transported by these 15 ambulances were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or who used self-arranged transport. RESULTS: Data were analysed from 197 patients with STEMI. The median patient delay for activation of the emergency response system was 90 minutes; 12% of patients experienced a delay of >12 hours. There was a significant difference in delay between patients transported by ambulance and those who used self-arranged transport (P<0.001). For system delay, the use of prehospital ECG shortened the median time from ambulance on scene to first ECG (P<0.001). When performed upon ambulance on scene, prehospital ECG was available 5 minutes earlier than if performed in ambulance compartment before departure. Use of prehospital ECG significantly shortened AED door-to-triage time, AED door-to-first AED ECG time, AED door-to-physician consultation time, and length of stay in the AED (P<0.001 for all comparisons). CONCLUSION: Prehospital ECG shortened ischaemic time prior to hospital admission.


Assuntos
Ambulâncias/estatística & dados numéricos , Eletrocardiografia , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Tempo para o Tratamento , Idoso , Angioplastia Coronária com Balão , Dor no Peito/etiologia , Serviço Hospitalar de Emergência , Feminino , Hong Kong , Humanos , Masculino , Estudos Retrospectivos , Fatores de Tempo , Triagem
3.
Hong Kong Med J ; 24(5): 484-491, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30262677

RESUMO

INTRODUCTION: After ST-segment elevation myocardial infarction (STEMI), it is vital to shorten reperfusion time. This study examined data from a pilot project to shorten the door-to-balloon (D2B) time by using prehospital 12-lead electrocardiogram (ECG). METHODS: Fifteen ambulances equipped with X Series® Monitor/Defibrillator (Zoll Medical Corporation) were deployed to the catchment area of Queen Mary Hospital, Hong Kong, from November 2015 to December 2016. For patients with chest pain, prehospital 12-lead ECG was performed and tele-transmitted to attending physicians at the accident and emergency department for immediate interpretation. The on-call cardiologist was called before patient arrival if STEMI was suspected. Data from this group of patients with STEMI were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or by self-arranged transport. RESULTS: From 841 patients with chest pain, 731 gave verbal consent and prehospital ECG was performed and transmitted. Of these, 25 patients with clinically diagnosed STEMI required emergency coronary angiogram with or without primary percutaneous coronary intervention. The mean D2B time for these 25 patients (93 minutes) was significantly shorter (P=0.003) than that for 58 patients with STEMI transported by ambulances without prehospital ECG (112 minutes) and that for 41 patients with STEMI with self-arranged transport (138 minutes). However, shorter reperfusion time was only recorded during daytime hours (08:00-17:59). No statistically significant difference in 30-day mortality was found. CONCLUSION: Prehospital ECG is technologically feasible in Hong Kong and shortens the D2B time. However, shorter reperfusion time was only recorded during daytime hours.


Assuntos
Eletrocardiografia/instrumentação , Serviços Médicos de Emergência/normas , Infarto do Miocárdio/diagnóstico , Avaliação de Resultados em Cuidados de Saúde , Idoso , Dor no Peito/etiologia , Árvores de Decisões , Feminino , Hong Kong , Humanos , Masculino , Infarto do Miocárdio/complicações , Infarto do Miocárdio/fisiopatologia , Projetos Piloto , Estudos Retrospectivos
4.
Clin Chim Acta ; 478: 45-50, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29247634

RESUMO

BACKGROUND: CYP2C19, a member of cytochrome P450 enzymes, is involved in various drug metabolisms, such as Clopidogrel. Common Single Nucleotide Polymorphisms (SNPs) of CYP2C19 gene, CYP2C19*2 and CYP2C19*3, are liable for the poor metabolism of Clopidogrel. It is crucial to identify poor metabolizers for alternative treatment as poor metabolism of Clopidogrel has been shown to correlate with worse clinical outcome in acute coronary syndrome (ACS) patients. METHOD: A genotyping method, Loop-mediated isothermal amplification (LAMP) was employed in this study. CYP2C19*2 and CYP2C19*3 were adapted from Iwasaki M. et al. with modifications in the reaction mixtures and end-point detection method where simpler visual detection using SYBR® Safe was employed instead of a more technical and equipment demanding real-time PCR. Real-time PCR melting curve analysis is a common method for SNPs analysis and hence chosen as a reference for results obtained from the LAMP assay. RESULTS: The CYP2C19-LAMP assay successfully detected CYP2C19*2 and CYPC19*3 mutants. The typing results of CYP2C19-LAMP assay, performed in triplicates, were concordant with the real-time PCR melting curve analysis results. CONCLUSION: CYP2C19-LAMP assay using SYBR® Safe dye for visual detection of end-point result is a simple, rapid and cost-effective method for CYP2C19 genotyping.


Assuntos
Citocromo P-450 CYP2C19/genética , Técnicas de Genotipagem , Técnicas de Amplificação de Ácido Nucleico/normas , Farmacogenética/métodos , Polimorfismo de Nucleotídeo Único , Síndrome Coronariana Aguda/tratamento farmacológico , Síndrome Coronariana Aguda/genética , Clopidogrel , Genótipo , Humanos , Preparações Farmacêuticas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Ticlopidina/análogos & derivados , Ticlopidina/metabolismo , Ticlopidina/uso terapêutico , Temperatura de Transição
5.
Epidemiol Infect ; 141(8): 1625-39, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23013659

RESUMO

By building reconstruction models for a case of gastroenteritis in the general population moving through different steps of the surveillance pyramid we estimated that millions of illnesses occur annually in the European population, leading to thousands of hospitalizations. We used data on the healthcare system in seven European Union member states in relation to pathogen characteristics that influence healthcare seeking. Data on healthcare usage were obtained by harmonized cross-sectional surveys. The degree of under-diagnosis and underreporting varied by pathogen and country. Overall, underreporting and under-diagnosis were estimated to be lowest for Germany and Sweden, followed by Denmark, The Netherlands, UK, Italy and Poland. Across all countries, the incidence rate was highest for Campylobacter spp. and Salmonella spp. Incidence estimates resulting from the pyramid reconstruction approach are adjusted for biases due to different surveillance systems and are therefore a better basis for international comparisons than reported data.


Assuntos
Infecções por Campylobacter/epidemiologia , Criptosporidiose/epidemiologia , Infecções por Enterobacteriaceae/epidemiologia , Gastroenterite/epidemiologia , Vigilância da População , Animais , Campylobacter/isolamento & purificação , Infecções por Campylobacter/microbiologia , Criptosporidiose/parasitologia , Cryptosporidium/isolamento & purificação , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Europa (Continente)/epidemiologia , União Europeia , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/parasitologia , Gastroenterite/microbiologia , Gastroenterite/parasitologia , Humanos , Incidência , Modelos Biológicos , Zoonoses/epidemiologia , Zoonoses/microbiologia , Zoonoses/parasitologia
6.
Epidemiol Infect ; 139(11): 1676-86, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21205382

RESUMO

The objective of this study was to investigate risk factors for norovirus-associated infectious intestinal disease (IID) and asymptomatic norovirus infection. Individuals with IID and healthy controls were recruited in a community-based study in England (1993-1996). This is the first risk-factor study to use viral load measurements, generated by real-time RT-PCR, to identify cases of norovirus-associated IID and asymptomatic infections. Using multivariable logistic regression the main risk factor identified for norovirus-associated IID was contact with a person with IID symptoms. Infectious contacts accounted for 54% of norovirus cases in young children and 39% of norovirus cases in older children and adults. For young children, contacts outside the household presented the highest risk; for older children and adults, the highest risk was associated with child contacts inside the household. Foreign travel and consumption of shellfish increased the risk of norovirus-associated IID. Lifestyle and dietary factors were associated with a decreased risk of both norovirus-associated IID and asymptomatic infection. No risk factors were identified for asymptomatic norovirus infection.


Assuntos
Infecções Assintomáticas/epidemiologia , Infecções por Caliciviridae/epidemiologia , Infecções Comunitárias Adquiridas/epidemiologia , Gastroenterite/epidemiologia , Norovirus/isolamento & purificação , Adolescente , Adulto , Infecções por Caliciviridae/virologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/virologia , Inglaterra/epidemiologia , Características da Família , Comportamento Alimentar , Gastroenterite/virologia , Humanos , Lactente , Análise Multivariada , Fatores de Risco , Viagem
8.
Neurology ; 75(10): 924-32, 2010 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-20820004

RESUMO

BACKGROUND: The threat of emerging infections and recognition of novel immune-mediated forms of encephalitis has raised the profile of this condition in recent years. Incidence is poorly defined and most cases have an unknown cause. There is currently much interest in identification of new microbial agents of encephalitis, but no work has investigated systematically reasons for lack of pathogen identification in studies. METHODS: We systematically reviewed published literature on incidence and etiology of encephalitis in non-outbreak settings and explored possible explanations for the large number of cases of unknown etiology. RESULTS: Annual incidence ranged from 0.07 to 12.6 cases per 100,000 population with an evident decrease over time (p = 0.01). The proportion of cases with unknown etiology was high across studies (>50% in 26 of 41 studies), with strong evidence of heterogeneity in study findings (p < 0.001). Our meta-regression identified study period, setting, and subsyndrome to be the main contributors to between-study variation, rather than methodologic factors such as study design, case definitions, sample types, and testing strategies. CONCLUSIONS: Our findings support the hypothesis that new and emerging infectious agents, or new forms of immune-mediated encephalitis, may be responsible for cases currently of unknown cause and encourage the ongoing global effort to identify these. Our review highlights research areas that might lead to a better understanding of the causes of encephalitis and ultimately reduce the morbidity and mortality associated with this devastating condition.


Assuntos
Surtos de Doenças , Encefalite/epidemiologia , Encefalite/etiologia , Humanos , Incidência
9.
Epidemiol Infect ; 138(10): 1454-8, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20196905

RESUMO

Norovirus is a major cause of infectious intestinal disease, and a substantial prevalence of asymptomatic infection has been reported. We describe the prevalence, seasonality and characteristics of asymptomatic norovirus infection in England. Healthy individuals were recruited at random from the general population during the Study of Infectious Intestinal Disease (1993-1996). Norovirus was identified using real-time RT-PCR. The age-adjusted prevalence of asymptomatic norovirus infection was 12%; prevalence was highest in children aged <5 years and showed wintertime seasonality. More work is needed to understand whether asymptomatic infections are important for norovirus transmission leading to sporadic illness and outbreaks.


Assuntos
Infecções por Caliciviridae/epidemiologia , Infecções Comunitárias Adquiridas/epidemiologia , Gastroenterite/epidemiologia , Norovirus/isolamento & purificação , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Infecções por Caliciviridae/virologia , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/virologia , Inglaterra/epidemiologia , Fezes/virologia , Feminino , Gastroenterite/virologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estações do Ano , Adulto Jovem
10.
Proc Biol Sci ; 277(1683): 933-42, 2010 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-19939844

RESUMO

In Europe, rotavirus gastroenteritis peaks in late winter or early spring suggesting a role for weather factors in transmission of the virus. In this study, multivariate regression models adapted for time-series data were used to investigate effects of temperature, humidity and rainfall on reported rotavirus infections and the infection-rate parameter, a derived measure of infection transmission that takes into account population immunity, in England, Wales, Scotland and The Netherlands. Delayed effects of weather were investigated by introducing lagged weather terms into the model. Meta-regression was used to pool together country-specific estimates. There was a 13 per cent (95% confidence interval (CI), 11-15%) decrease in reported infections per 1 degrees C increase in temperature above a threshold of 5 degrees C and a 4 per cent (95% CI, 3-5%) decrease in the infection-rate parameter per 1 degrees C increase in temperature across the whole temperature range. The effect of temperature was immediate for the infection-rate parameter but delayed by up to four weeks for reported infections. There was no overall effect of humidity or rainfall. There is a direct and simple relationship between cold weather and rotavirus transmission in Great Britain and The Netherlands. The more complex and delayed temperature effect on disease incidence is likely to be mediated through the effects of weather on transmission.


Assuntos
Surtos de Doenças , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/transmissão , Rotavirus/crescimento & desenvolvimento , Pré-Escolar , Humanos , Incidência , Lactente , Análise Multivariada , Países Baixos/epidemiologia , Análise de Regressão , Infecções por Rotavirus/virologia , Estações do Ano , Reino Unido/epidemiologia , Tempo (Meteorologia)
11.
Euro Surveill ; 14(20)2009 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-19460285

RESUMO

Two rotavirus vaccines have recently been licensed in Europe. Rotavirus surveillance data in many European countries are based on reports of laboratory-confirmed rotavirus infections. If surveillance data based on routine laboratory testing data are to be used to evaluate the impact of vaccination programmes, it is important to determine how the data are influenced by differences in testing practices, and how these practices are likely to affect the ability of the surveillance data to represent trends in rotavirus disease in the community. We conducted a survey of laboratory testing policies for rotavirus gastroenteritis in England and Wales in 2008. 60% (94/156) of laboratories responded to the survey. 91% of reporting laboratories offered routine testing for rotavirus all year round and 89% of laboratories offered routine rotavirus testing of all stool specimens from children under the age of five years. In 96% of laboratories, rotavirus detection was presently done either by rapid immunochromatographic tests or by enzyme-linked immunosorbent assay. Currently, rotavirus testing policies among laboratories in England and Wales are relatively homogenous. Therefore, surveillance based on laboratory testing data is likely to be representative of rotavirus disease trends in the community in the most frequently affected age groups (children under the age of five years) and could be used to help determine the impact of a rotavirus vaccine.


Assuntos
Técnicas de Laboratório Clínico , Infecções por Rotavirus/epidemiologia , Vacinas contra Rotavirus , Rotavirus/efeitos dos fármacos , Rotavirus/isolamento & purificação , Inglaterra/epidemiologia , Política de Saúde , Humanos , Programas de Imunização , Vigilância da População/métodos , Infecções por Rotavirus/prevenção & controle , Infecções por Rotavirus/virologia , Inquéritos e Questionários , Resultado do Tratamento , País de Gales/epidemiologia
12.
Epidemiol Infect ; 137(7): 957-60, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19144248

RESUMO

This study investigates whether a child's risk of rotavirus diarrhoea is associated with season of birth in England and Wales, countries where rotavirus infections are highly seasonal. Poisson regression models were fitted to weekly counts of laboratory-confirmed rotavirus infections from children aged <5 years born between 1998 and 2007. In the first year of life, the risk of a laboratory-confirmed rotavirus infection was significantly higher for children born in summer compared with winter [relative risk (RR) 2.13, 95% confidence interval (CI) 2.07-2.19]. In the second to fifth years of life, the pattern reversed (second year of life: RR 0.73, 95% CI 0.71-0.75). The cumulative risk up to age 5 years remained significantly higher for children born in summer compared with winter due to the increased risk for summer births during their first year of life. Maternal immunity and age-specific levels of exposure to rotavirus could explain our findings.


Assuntos
Diarreia/epidemiologia , Diarreia/virologia , Parto , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/etiologia , Estações do Ano , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Fatores de Risco
13.
Epidemiol Infect ; 134(1): 119-25, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16409658

RESUMO

Campylobacter is the most common bacterial cause of gastroenteritis in England and Wales, with 45000 cases reported annually. Campylobacter incidence is highly seasonal; the consistent peak in late spring suggests a role for meteorological factors in the epidemiology of this organism. We investigated the relationship between ambient temperature and Campylobacter enteritis using time-series analysis to study short-term associations between temperature and number of Campylobacter reports adjusted for longer-term trend and seasonal patterns. We found a linear relationship between mean weekly temperature and reported Campylobacter enteritis, with a 1 degrees C rise corresponding to a 5% increase in the number of reports up to a threshold of 14 degrees C. There was no relationship outside this temperature range. Our findings provide evidence that ambient temperature influences Campylobacter incidence, and suggest that its effect is likely to be indirect, acting through other intermediate pathways.


Assuntos
Infecções por Campylobacter/epidemiologia , Enterite/epidemiologia , Enterite/microbiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Inglaterra/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Estações do Ano , Temperatura
15.
J Infect ; 47(1): 28-32, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12850159

RESUMO

OBJECTIVES: Campylobacters are the most common bacterial cause of infectious intestinal disease (IID) in temperate countries. C. jejuni is the predominant cause of campylobacter IID, but the impact of other, less prevalent species has largely been ignored. Here, we present estimates of the burden of indigenously acquired foodborne disease (IFD) due to Campylobacter coli, the second most common cause of human campylobacteriosis. METHODS: Data from surveillance sources and specific epidemiologic studies were used to calculate the number of illnesses, presentations to general practice (GP), hospital admissions, hospital occupancy and deaths due to indigenous foodborne C. coli IID in England and Wales for the year 2000. RESULTS: We estimate that in the year 2000, C. coli accounted for over 25,000 cases of IFD. This organism was responsible for more than 12,000 presentations to GP, 1000 hospital admissions, nearly 4000 bed days of hospital occupancy and 11 deaths. The cost to patients and the National Health Service was estimated at nearly pound 4 million. CONCLUSIONS: Although C. coli comprises a minority of human campylobacter disease, its health burden is considerable and greater than previously thought. Targeted research on this organism is required for its successful control.


Assuntos
Infecções por Campylobacter/epidemiologia , Campylobacter coli/isolamento & purificação , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/microbiologia , Inglaterra/epidemiologia , Humanos , Enteropatias/epidemiologia , Enteropatias/microbiologia , Vigilância da População , Fatores de Risco , País de Gales/epidemiologia
16.
Epidemiol Infect ; 130(3): 367-75, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12825720

RESUMO

Despite being the commonest bacterial cause of infectious intestinal disease (IID) in England and Wales, outbreaks of campylobacter infection are rarely reported. However, data from the Campylobacter Sentinel Surveillance Scheme suggested that outbreaks might be more common than was previously suspected, since a high proportion of cases reported other illness in the home or in the community at the same time as their illness. To identify factors that might lead to these apparent outbreaks, the exposures of cases of Campylobacter jejuni infection reporting other illness, either in the home or the community, were compared with those for cases not reporting other illness using case-case methodology. Illness in the home was associated with consuming organic meats in the winter, having contact with a pet suffering from diarrhoea or visiting a farm in the 2 weeks before the onset of symptoms. Illness in the community was associated with the consumption of foods in restaurants or drinking unpasteurized milk. Prevention of campylobacter infection requires that better methods of outbreak detection and investigation are developed, which in turn should lead to a better understanding of risk factors.


Assuntos
Infecções por Campylobacter/transmissão , Campylobacter jejuni , Surtos de Doenças/prevenção & controle , Enteropatias/prevenção & controle , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Agricultura , Animais , Animais Domésticos , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/prevenção & controle , Criança , Pré-Escolar , Inglaterra/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Enteropatias/epidemiologia , Enteropatias/microbiologia , Modelos Logísticos , Masculino , Carne/microbiologia , Pessoa de Meia-Idade , Leite/microbiologia , Estudos Retrospectivos , Fatores de Risco , País de Gales/epidemiologia
18.
Commun Dis Public Health ; 4(3): 194-9, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11732359

RESUMO

Infections due to Campylobacter spp. are the most commonly reported bacterial cause of human gastrointestinal illness, and reports of campylobacteriosis in the UK and other temperate countries have been increasing. An all-time peak of 58,059 cases of campylobacter infectious intestinal disease (IID) were reported to the Communicable Disease Surveillance Centre in 1998. An analysis of the age, gender and seasonal and geographical distribution of cases reported in 1998 is presented here, together with population-based estimates of reported incidence. The frequency of reports was highest in late Spring. Reported incidence was highest in males under 1 year of age (214/100,000 population), with a secondary peak in adults aged 25 to 34 years (140/100,000 population). Reported incidence was higher in males than females for all age groups. The highest reported incidence occurred in the South West region (140/100,000 population), while the lowest was observed in London (54/100,000 population). Campylobacter is a major cause of human gastrointestinal illness. Work towards its control must be a priority if the burden of human infectious intestinal disease is to be reduced.


Assuntos
Infecções por Campylobacter/epidemiologia , Notificação de Doenças/estatística & dados numéricos , Surtos de Doenças , Vigilância da População , Adulto , Distribuição por Idade , Animais , Criança , Feminino , Humanos , Incidência , Masculino , Estações do Ano , Distribuição por Sexo , Reino Unido/epidemiologia
19.
J Morphol ; 217(2): 219-27, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8371276

RESUMO

The morphogenesis of glandular architecture of the three lobes of prostate gland of the guinea pig, lateral, dorsal, and coagulating gland was studied from 35 days gestation to 90 postnatal days. Epithelial ductal tubules of various lobes of the gland were microdissected after treatment by collagenase and displayed two dimensionally. The number of ductal tips was counted, and the volume of the ductal network was quantified using a graphic tablet. The results show that the growth and ductal morphogenesis fall into two phases: prenatal and postnatal. The first outgrowth of prostatic buds begins at 35 days gestation (gestational length is 65 days). Ductal growth and branching continues over the next 15-20 days and by 55 days gestation, approximately 60%, 79%, and 71% of the adult number of ductal tips of the lateral and dorsal lobes and coagulating gland respectively, are formed. The figures increase to 89%, 84%, and 106%, respectively, by birth. There is little increase in number of ductal tips thereafter. Postnatal growth is accomplished mainly by elongation of existing ductal network with a little additional branching but with an increase in size (volume) of the tubules. Canalization of ductal tubules occurs prenatally in all lobes but postnatal functional cytodifferentiation takes a slightly different pace among them. Ductal morphogenesis of the guinea pig prostate gland differs significantly in time-course from that of the mouse in which ductal development occurs mainly postnatally.


Assuntos
Envelhecimento/fisiologia , Animais Recém-Nascidos/anatomia & histologia , Cobaias/embriologia , Cobaias/crescimento & desenvolvimento , Próstata/anatomia & histologia , Próstata/embriologia , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Masculino
20.
Histochem J ; 25(1): 77-85, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8432665

RESUMO

Ultrastructural localization of thiamine pyrophosphatase (TPPase) activity was studied in secretory cells of the lateral prostate and seminal vesicle of normal and castrated guinea pigs and castrates treated with 17 beta-oestradiol benzoate. The present study has demonstrated that TPPase reaction product is consistently localized in the three to four trans cisternae of Golgi complexes in both the lateral prostate and the seminal vesicle. The reaction was intense and the reaction product often filled the cisternae completely. After castration there was a decrease in TPPase activity in both glands as revealed by the reduction in the amount of the reaction product which was found mainly in one to two trans cisternae of the regressed Golgi complex. The reaction product changed from a dense to a more particulate or granular pattern or to discrete deposits of high electron-density. Administration of 17 beta-oestradiol benzoate to the castrates caused changes in the localization and patterns of distribution of TPPase. In the lateral prostate there was an apparent increase in TPPase activity. The reaction product was found in two to four trans cisternae and occasionally in the trans-most cisternae of the dilated Golgi complex. The reaction product appeared as discrete, dense coarse precipitates. In the seminal vesicle TPPase reaction product was consistently found in one to two trans cisternae in cells with larger Golgi complexes. However, almost all cisternae of the smaller Golgi complexes were TPPase-positive.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Castração , Estradiol/análogos & derivados , Próstata/enzimologia , Glândulas Seminais/enzimologia , Tiamina Pirofosfatase/metabolismo , Animais , Estradiol/farmacologia , Complexo de Golgi/enzimologia , Complexo de Golgi/ultraestrutura , Cobaias , Masculino , Microscopia Eletrônica , Próstata/efeitos dos fármacos , Próstata/ultraestrutura , Glândulas Seminais/efeitos dos fármacos , Glândulas Seminais/ultraestrutura
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