RESUMEN
A national cross-sectional seroprevalence survey was conducted in order to evaluate the current seroepidemiology of hepatitis A among 1,383 children, aged 0-14 years, residing in Greece. Stratification of the study population was conducted according to age and area of residence. Sera from study participants were tested for the presence of anti-HAV IgG antibodies. Immigrant children, as well as children residing in rural areas, had lower immunization rates. Among unvaccinated children, the seroprevalence rate of anti-HAV was 17.1%. Nationality was shown to have a marginally significant effect since non-immunized immigrant children had a higher seroprevalence rate (22.4% vs. 15.9%, OR = 1.52, P = 0.064). Significant differences between geographic areas for both vaccination coverage and natural immunity were observed. The study findings indicate that hepatitis A is prevalent in Greece and therefore universal infant hepatitis A immunization should be implemented.
Asunto(s)
Anticuerpos de Hepatitis A/sangre , Virus de la Hepatitis A/inmunología , Hepatitis A/epidemiología , Adolescente , Niño , Preescolar , Femenino , Grecia/epidemiología , Hepatitis A/inmunología , Hepatitis A/prevención & control , Anticuerpos de Hepatitis A/inmunología , Vacunas contra la Hepatitis A/administración & dosificación , Humanos , Lactante , Recién Nacido , Masculino , Prevalencia , Estudios Seroepidemiológicos , Vacunación/estadística & datos numéricosRESUMEN
The seroepidemiology of hepatitis B in children living in Greece 6 years post-implementation of universal infant immunization (1998) was studied. We collected 90-100 sera/year of age, stratified by geographic region. The prevalence of HbsAg(+) was 0.6% (95% CI 0.3-1.3) whereas 4.5% (95% CI 3.4-5.9%) of children over 12 months of age had evidence of past HBV infection. A significant decline in the prevalence of past infection between children born before and after 1998 (5.5% vs 2.9%; RR = 1.9, 95% CI 1.03-3.5) was noted. Conversely, the prevalence of past HBV infection did not change significantly among immigrant children. Reinforcement of early vaccination of immigrant population is necessary.
Asunto(s)
Anticuerpos contra la Hepatitis B/sangre , Antígenos de Superficie de la Hepatitis B/análisis , Vacunas contra Hepatitis B/administración & dosificación , Virus de la Hepatitis B/inmunología , Hepatitis B/epidemiología , Vacunación Masiva , Estudios Seroepidemiológicos , Adolescente , Análisis de Varianza , Distribución de Chi-Cuadrado , Niño , Preescolar , Grecia/epidemiología , Hepatitis B/prevención & control , Antígenos del Núcleo de la Hepatitis B/inmunología , Vacunas contra Hepatitis B/inmunología , Humanos , Lactante , Recién Nacido , Estudios LongitudinalesRESUMEN
AIM: The aim of this study is the evaluation of the cellular activity of the embryonal mesenchyme in order to investigate if the primitive lymph vessels are derived from clefts of the mesenchyme or from capillary offshoots from the endothelium of the veins. For this reason we applied the quantitative estimation of nucleolar organizer regions (NORs) in the endothelial cells of the lymph and blood vessels, as well as in the mesenchymal cells that surround these vessels. METHODS: Our material consisted of the histological sections from the proper mesenterium of 30 embryos in different stages of development (10th, 12th, 15th, 20th, 23th and 30th week). RESULTS: A statistically significant difference in the average AgNORs value in the endothelial (ANOVA, p<0.0001) and the mesenchymal cells (ANOVA, p<0.0001) between lymph vessels, blood vessels at close and blood vessels at distant regions (10th, 12th, 15th week) was found. There was no statistically significant difference of the average AgNORs value in the endothelial (ANOVA, p=0.55) and the mesenchymal cells (ANOVA, p=0.49) between lymph vessels, blood vessels at close and blood vessels at distant regions (20th, 23th, 30th week). CONCLUSION: The above results suggest that the development of the lymph vessels follows that of the blood vessels. Furthermore, the intense protein synthesis that is expressed by means of NORs in the mesenchymal cells surrounding lymph vessels from the 10th to the 15th week of development is an additional proof of the view that the primitive lymph vessels are derived from clefts into the embryonal mesenchyma and not from capillary offshoots of the endothelium of the blood vessels.
Asunto(s)
Sistema Linfático/embriología , Región Organizadora del Nucléolo/ultraestructura , Edad Gestacional , Humanos , Mesodermo/ultraestructura , Coloración y EtiquetadoRESUMEN
Differentiating mesenchymal cells and the extracellular matrix that these cells produce constitute the structural basis for developing organs. The splanchnopleuric mesenchyme surrounding the developing gut and respiratory tubes provides connective tissue cells to the lamina propria/submucosa and smooth muscle cells to the muscularis musosae/muscularis externa. In human fetal intestine, the identity of the matrix-producing cell or cells has begun to be elucidated. The smooth muscle cell is one of the sources of collagen fibers in the extracellular matrix in the developing human fetal intestine and collagen production is a significant function of smooth muscle cells during intestinal organogenesis. The aim of the current study was the quantitative investigation of collagen production by human fetal intestinal smooth muscle cells in various stages of development (10 to 23 weeks of gestational age). Identification of the mesenchymal cells/extracellular matrix was confirmed by immunohistochemical techniques using the following monoclonal antibodies: actin, desmin, vimentin, collagen IV and fibronectin. Histochemical stains for the presence of extracellular matrix components were also performed. Immunohistochemical analysis and the results of the histochemistry of the fetal human intestine in various stages of development revealed that the muscle cells of the muscularis externa contribute to the production of collagen in collaboration with the mesenchymal cells. This is more evident between 10 to 14 weeks of gestational age.
Asunto(s)
Colágeno/biosíntesis , Matriz Extracelular/metabolismo , Intestinos/embriología , Miocitos del Músculo Liso/metabolismo , Actinas/metabolismo , Anticuerpos Monoclonales , Colágeno Tipo IV/metabolismo , Desmina/metabolismo , Humanos , Inmunohistoquímica , Vimentina/metabolismoRESUMEN
A rare case of sirenomelia at 38 weeks of gestation is reported. Fusion of the lower extremities and incomplete development of the bony pelvis was associated with agenesis of the urinary and genital systems, anorectal atresia and a single large umbilical artery. There was complete situs inversus of the single lower limb. This was composed of two partially fused femurs, a common tibia without fibula, and a rudimentary foot having three metatarsal bones and their corresponding toes. The present case was also interesting for its association with hypoplasia of the lungs. The pathogenesis of sirenomelia is discussed.
Asunto(s)
Anomalías Múltiples , Ectromelia , Anomalías Múltiples/patología , Adulto , Ectromelia/complicaciones , Ectromelia/patología , Femenino , Muerte Fetal , Humanos , Oligohidramnios/complicaciones , Embarazo , Arterias Umbilicales/anomalíasRESUMEN
Most spontaneous abortions occur before 12 weeks' gestation, and most are due to chromosomal errors in the conceptus. Relatively few truly spontaneous abortions take place between 12 and 20 weeks' gestation. Thereafter, between 20 and 30 weeks another type of premature spontaneous termination due to ascending infection becomes prevalent. The number of cells expressing the various lymphocytic markers changes throughout pregnancy. In the present study, we investigated the immunohistochemical expression of mononuclear infiltrations in paraffin-embedded placentas, from fetuses after spontaneous abortion (8th, 10th, and 12th week of gestational age), and those after therapeutic abortion at the same time, using a panel of monoclonal antibodies for the identification of leukocytes (CD45/LCA), B-lymphocytes (CD20/L-26), T-lymphocytes (CD45RO/UCHL1) and CD5 cells. Immunologic factors in human reproductive failure are plausible mechanisms of infertility and spontaneous abortion. Approximately 25% of cases of premature ovarian failure appear to result from an autoimmune etiology. Unfortunately, current therapeutic options for these women are limited to exogenous hormone or gamete substitution. Local inflammation at the sites of endometriosis implants are postulated to mediate the pain and reduce fecundability associated with this clinical syndrome. The recruitment of immune cells, particularly monocytes and T cells, neovascularization around foci of invading peritoneal lesions, and the possible development of antiendometrial autoantibodies support an immunologic basis of this disorder. To date, treatment of pain and infertility associated with endometriosis is primarily surgical, although immune-based adjuvants are theoretical possibilities for the future. Finally, although hypotheses supporting immunologic mechanisms of recurrent pregnancy loss have been popular over the past decade, most clinical investigations in this area do not provide compelling evidence for this position. Reputable specialists in reproductive medicine use experimental immunotherapies judiciously in selected cases of repetitive abortion. For example, the use of anticoagulation therapy can be beneficial in cases with documented antiphospholipid antibodies. At present, however, efficacious immunotherapy protocols for general application have not been established. Despite these caveats, continued strides in our understanding of human reproductive immunology, should yield considerable future progress in this field. We conclude that, 1) maternal cells, probably CD45RO/UCHL1 positive cells, cross the maternofetal barrier and participate in spontaneous (involuntary) abortions, 2) a small proportion of maternal cells (approximately 30%), probably CD5 positive cells, also cross the maternal fetal barrier and cause growth delay and recurrent reproductive failure. The results were statistically significant (p < 0.0001, Student's t-test).
Asunto(s)
Aborto Espontáneo/inmunología , Antígenos CD5/análisis , Placenta/metabolismo , Anticuerpos Monoclonales , Femenino , Humanos , Técnicas para Inmunoenzimas , Inmunohistoquímica , Placenta/inmunología , Placenta/patología , Embarazo , Primer Trimestre del EmbarazoRESUMEN
Standing height and peak expiratory flow rate (PEFR) were measured in 339 British schoolchildren aged 7-16 years. Enquiry was made into a past history of wheeze or atopy, a family history of asthma or atopy, or a cold within the preceding 2 weeks. A strong correlation was found between PEFR and height, expressed by the equation PEFR = 5.640 Ht - 472.5 (r = 0.89). Neither a recent cold nor a positive personal or family history of wheeze or atopy had any significant effect on the regression equation. Sex was also unimportant. Further examination of the data revealed that age had an effect on peak expiratory flow rate independent of height. The effect of age was linear in girls and curvilinear in boys. Five hundred and sixty-nine Greek schoolchildren were also studied and similar age effects were found on the regression of peak expiratory flow rate on height. The implication of these findings is that any population study of peak expiratory flow rates in children should ensure a normal age distribution at each height interval. Significant error in the prediction of the PEFR will result if the effect of age is ignored, particularly in pubertal boys.
Asunto(s)
Flujo Espiratorio Forzado , Ápice del Flujo Espiratorio , Adolescente , Factores de Edad , Asma/fisiopatología , Estatura , Niño , Femenino , Humanos , Masculino , Hipersensibilidad Respiratoria/fisiopatología , Ruidos Respiratorios/fisiopatologíaRESUMEN
Peak expiratory flow rate (PEFR) and standing height (Ht) were measured in 522 healthy Greek children aged 7-16 years. The regression equation of PEFR on height in centimetres was PEFR = 5.34 Ht--380.8. This demonstrated markedly higher values for PEFR in Greek children compared to previously published data from other countries. A sample of 339 British children was examined similarly. The regression equation of PEFR on height in centimetres was PEFR = 5.64 Ht--472.5. This was similar to previously published data. No cause for this discrepancy was found after close examination of population sampling, measurement error or calibration error in the Greek study. It is therefore concluded that Greek children appear to have an unexpectedly high PEFR for height.