Argininosuccinate lyase in enterocytes protects from development of necrotizing enterocolitis.

Necrotizing enterocolitis (NEC), the most common neonatal gastrointestinal emergency, results in significant mortality and morbidity, yet its pathogenesis remains unclear. Argininosuccinate lyase (ASL) is the only enzyme in mammals that is capable of synthesizing arginine. Arginine has several homeostatic roles in the gut and its deficiency has been associated with NEC. Because enterocytes are the primary sites of arginine synthesis in neonatal mammals, we evaluated the consequences of disruption of arginine synthesis in the enterocytes on the pathogenesis of NEC. We devised a novel approach to study the role of enterocyte-derived ASL in NEC by generating and characterizing a mouse model with enterocyte-specific deletion of Asl (Asl(flox/flox); VillinCre(tg/+), or CKO). We hypothesized that the presence of ASL in a cell-specific manner in the enterocytes is protective in the pathogenesis of NEC. Loss of ASL in enterocytes resulted in an increased incidence of NEC that was associated with a proinflammatory state and increased enterocyte apoptosis. Knockdown of ASL in intestinal epithelial cell lines resulted in decreased migration in response to lipopolysaccharide. Our results show that enterocyte-derived ASL has a protective role in NEC.

A rare occurrence of hairy cell leukemia in a congolese child: a presentation and challenge of diagnosis in low resource settings.

BACKGROUND: Hairy cell leukemia is a rare form of leukemia and has been rarely reported in African and pediatric population. OBSERVATION: We are reporting a 4-year-old child who was received for investigation for persistent anemia, prolonged fever, and thrombocytopenia. Bone marrow aspiration showed hypercellular marrow with cells characterized by irregular windblown-appearing cell borders with pseudopod-like projections. Our patient presented with hairy cell leukemia. CONCLUSION: The diagnosis was thought to be most consistent with hairy cell leukemia based on the distinctive morphology of the cells.

Helper-dependent adenoviral gene therapy mediates long-term correction of the clotting defect in the canine hemophilia A model.

BACKGROUND: Adenoviral vector-mediated gene therapy might have potential for long-term correction of the monogenic disease hemophilia A. OBJECTIVE: In this study, we tested the efficacy of administering a helper-dependent adenoviral vector (HDV) designed for maximal liver-restricted canine factor VIII (cFVIII) expression on three out-bred hemophilia A dogs. METHODS: Three FVIII-deficient animals from the University of North Carolina colony were injected with 1 x 10(12) (Dog A), and 3 x 10(12) (Dog B and C) vp kg(-1) helper-dependent adenoviral vector, and we performed systematic analysis of toxicity, persistence of therapeutic gene expression, and molecular analysis of gene transfer. RESULTS: We observed acute dose-dependent elevation in liver enzymes and thrombocytopenia after injection, although both were transient and resolved within 2 weeks. The whole blood clotting time (WBCT), plasma FVIII concentration, FVIII activity, and activated partial thromboplastin time in all animals improved significantly after treatment, and two animals receiving a higher dose reached near normal WBCT with low-level FVIII activity until terminal sacrifice at 3 months, and 2 years. Importantly, the treated dogs suffered no bleeding events after injection. Moreover, we observed persistent vector-specific DNA and RNA in liver tissue collected from one high-dose animal at days 18 and 79, and could not detect the formation of inhibitory antibodies. CONCLUSION: Although vector-associated toxicity remains an obstacle, a single injection of HDV led to long-term transgene expression and vector persistence in two FVIII-deficient animals with conversion of their severe phenotype to a moderate one.

Prevention of acute NSAID-related gastroduodenal damage: a meta-analysis of controlled clinical trials.

No consensus exists as to whether cotherapy is effective in the short-term prevention of severe NSAID-related gastroduodenal damage. The aim of this study was to provide a quantitative systematic review of the efficacy of gastroprotective drugs, such as misoprostol, H2-blockers, and proton pump inhibitors (PPI) in preventing the severe acute NSAID-related gastroduodenal damage. Placebo-controlled randomized clinical trials on the use of misoprostol, H2-blockers, and PPIs as preventative agents published between January 1986 and May 1999 were identified through Medline and reference lists from clinical reviews. Studies on patients or healthy subjects were considered to be eligible for data pooling if they were performed in acute NSAID users (not longer than 30 days) and with at least one endoscopic evaluation during therapy that reported results specifically for gastric and duodenal damage. Risk difference (RD), heterogeneity chi2 test, publication bias assessment and number needed to treat (NnT) were calculated for each meta-analysis by a customized program. Twenty-one trials met the inclusion criteria evaluating a total of 636 healthy subjects and 1904 patients with arthritis randomized to active drug or placebo. The baseline risk of NSAID-related gastric (68% vs 16.6%, P < 0.001) and duodenal (22% vs 8.5%, P < 0.001) damage was higher in healthy subjects compared to patients with arthritis. Meta-analysis demonstrated a significant heterogeneity between trials performed in the two populations (P < 0.0001). In healthy subjects the active drug treatment induced a significant prevention of severe gastric (misoprostol RD = 69%, 95% CI = 60.3-77.7, H2-blocker RD = 38.3%, 95% CI = 17.8-58.9 and PPI RD = 43%, 95% CI = 28.2-57.7) and duodenal damage (misoprostol RD = 22.3%, 95% CI = 13.6-31, H2-blocker RD = 13.2%, 95% CI = 5.2-21.3 and PPI RD = 17.7%, 95% CI = 3.5-31.8). NnT values were, respectively, 1, 3, and 2 for gastric and 4, 8, and 6 for duodenal damage. In patients with arthritis lower RD and higher NnT values were found compared to healthy subjects. In conclusions, cotreatment with gastroprotective drugs for short-term prevention of severe gastroduodenal NSAID-related damage was more effective in healthy subjects than in patients with arthritis; misoprostol and PPIs were more effective than H2-blockers in the prevention of both gastric and duodenal severe damage; more studies need to evaluate the role of short-term prevention in patients with arthritis who require acute NSAID treatment.

Integrin expression on neutrophils and mononuclear cells in blood and induced sputum in stable asthma.

BACKGROUND: We speculated that the expression of integrins in the airway lumen of asthmatic subjects might be altered compared with normal subjects during cell recruitment from circulation. METHODS: To test this hypothesis, we investigated the expression of integrin alpha-chains (CD11a, CD11b, and CD11c) in hypertonic saline-induced sputum and peripheral blood leukocytes in mild to moderate stable asthmatic and control subjects. Immunoreactivity for integrin alpha-chains was assessed by immunocytology on cytospin preparations of sputum and blood. RESULTS: In comparison of the percentages of CD11a+, CD11b+ and CD11c+ mononuclear cells in sputum with their blood counterparts, no significant differences were observed in control subjects, whereas CD11a and CD11b in asthmatic subjects were less expressed on sputum cells. In both control and asthmatic subjects, sputum neutrophils tended to decrease their expression of integrin alpha-chains compared with circulating neutrophils. CONCLUSIONS: We showed that the sputum of asthmatics, unlike normal subjects, is characterized by decreased expression of integrins on mononuclear cells compared with their blood counterparts. The results suggest that downregulation of integrins occurs in asthmatic airways after cell recruitment from circulation.

Integrin upregulation on sputum neutrophils in smokers with chronic airway obstruction.

To determine the relationship between the expression of leukocyte-specific integrins in the airways and the airway obstruction in smokers, we analyzed hypertonic saline-induced sputum in 33 male subjects, age 64.7 +/- 0.5 yr (mean +/- SEM), with a smoking history of 12 to 94 pack-years, at the end of a 15-yr follow-up study. Average FEV1/VC ratio was 69 +/- 1% at the beginning of the study and 66 +/- 2% at the end of the follow-up period, and annual decline of FEV1 was 20 +/- 3 ml/yr. Fourteen individuals exhibited airway obstruction as assessed by a FEV1/VC ratio lower than 63.3%. Differential leukocyte count was performed on cytospin preparations and the expression of integrin alpha (CD11a, CD11b, CD11c) and beta (CD18) chains was assessed on granulocytes and mononuclear cells by immunocytology. The numbers of neutrophils expressing CD11b and CD18, but not CD11c or CD11a, were increased in the subjects with airway obstruction compared with those without airway obstruction. CD11b- and CD18-positive neutrophils were negatively correlated with FEV1/VC ratio (p < 0.01). No significant correlations were found between CD11a-, CD11b-, CD11c-, CD18-positive mononuclear cells and lung function measurements. In conclusion, our results suggest that leukocyte-specific integrin CD11b/CD18 expressed on sputum polymorphonuclear leukocytes represents a marker for the smokers who develop chronic airway obstruction.

Two different dosages of yeast derived recombinant hepatitis B vaccines: a comparison of immunogenicity.

The efficacy of a 10 or 20 micrograms antigen load of HB recombinant vaccines is still being debated. A comparison of anti-HBs titres in two groups of healthy subjects vaccinated by the same schedule (0, 1 and 6 months) employing recombinant HB vaccines with different antigen loads, 20 micrograms (group A, 251 subjects) and 10 micrograms (group B, 256 subjects) was carried out. A seroprotection rate of 99.6 and 99.2% was observed for group A and group B, respectively, at the end of primary immunization. No statistically significant difference in seroprotection rate was observed. Group A showed significantly higher GMTs than group B for all age groups and for both sexes except for males above 25 years. The difference was more marked for younger age groups and for the female sex. These data support the higher immunogenicity of vaccine with 20 micrograms antigen load as compared to vaccines with 10 micrograms antigen load.

[Epidemiological study of mortality in a cohort of rayon industry employees]. / Studio epidemiologico di mortalità in una coorte di addetti alla produzione del rayon viscosa.

A cohort of 166 employees in the SNIA viscosa rayon production plant in Padua was followed up for mortality up to 1989. The study detected a statistically significant increase in total mortality mainly due to an excess of deaths from ischaemic heart diseases (ICD 410-414). Workers affected by occupational disease in the age group 50-64 years had the highest risk with a threefold increase in mortality compared to the general population. An increasing pattern of lung cancer mortality with time since first exposure was observed. The SMR for lung cancer was 192 for smokers with occupational disease.

Variability of expression in tuberous sclerosis.

We present three families in whom a diagnosis of tuberous sclerosis is difficult to secure and we review published reports about similar cases. Tuberous sclerosis has been reported to affect as many as 1 in 9400 subjects in the population. The manifestations of this disease vary not only between but also within families. Currently no reliable method of prenatal diagnosis is available. For these reasons, subjects known to be at 50% risk should be assessed scrupulously to clarify their status. These cases illustrate the difficulties in the clinical diagnosis of tuberous sclerosis and further reinforce the need for a molecular method of determining whether an at risk subject has the disease.

Are homes for the elderly still a risk area for HBV infection?

To verify whether improvements in hygiene affect the risk of HBV infection, a seroepidemiological survey on HBV infection was carried out in a home for the elderly with continuous-care accommodation. HBV serum markers were tested in 315 subjects and the results of HBV infection were compared to those observed in two different types of nursing homes for the elderly from an earlier seroepidemiological study carried out in 1978. In addition, results from a cohort of a pre-geriatric population living in their own homes in the same geographical area surveyed in 1980 were compared to the present study. A statistically significant lower prevalence of HBV serum markers in the new home for the elderly compared to the two types studied in 1978 was observed. No difference was found between the new institutionalized study group and the cohort of a pre-geriatric population surveyed in 1980. These results reflect the improved sanitation in homes for the elderly and show that the elderly have very few opportunities to become infected, even in a close cohabitation system.

Hepatitis C virus infection, HBsAg carrier state and hepatocellular carcinoma: relative risk and population attributable risk from a case-control study in Italy.

In 1990, a case-control study was conducted in Italy to investigate the possible association between HCV infection and hepatocellular carcinoma (HCC). Serum samples from 65 subjects with newly diagnosed hepatocellular carcinoma and 99 hospital control subjects were tested for the presence of anti-HCV by second-generation ELISA test; positive sera were assayed by RIBA anti-HCV second-generation test. In addition, samples were tested for hepatitis B surface antigen (HBsAg), antibodies to the hepatitis B core antigen (anti-HBc), and antibodies to HBsAg (anti-HBs). The presence of HCV and/or HBsAg serologic markers was significantly associated with hepatocellular carcinoma risk: the relative risk (RR) of HCC was 21.3 (95% CI = 8.8-51.5) for anti-HCV positivity in the absence of HBsAg; the relative risk of HCC was 13.3 (95% CI = 5.5-32.2) for the presence of HBsAg in the absence of anti-HCV. A higher risk (77.0) was observed when both markers were present. These findings indicate that HCV and HBsAg are independent risk factors for HCC. The results of multivariate analysis showed that the adjusted RR linking anti-HCV and HCC was 26.9 (95% CI = 9.9-72.5), the adjusted RR linking HBsAg and HCC was 11.4 (95% CI = 3.1-41.4), whereas no association (RR 1.5; 95% CI = 0.6-3.6) was found to link HCC with anti-HBc and/or anti-HBs positivity. Through the computation of population attributable risk we estimate that 25% of HCC cases occurring in Italy could be attributed to anti-HCV positivity alone and 20% to HBsAg carrier state alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Gene diversity and estimation of genetic admixture among Mexican-Americans of Starr County, Texas.

The Mexican-Americans of Starr County, Texas, classified by sex and birthplace, were studied to determine the extent of genetic variation and contributions from ancestral populations such as Spanish, Amerindian and West African. Using 21 genetic marker systems, genetic distance and diversity analyses indicate that subpopulations of Mexican-Americans in Starr County are similar, and that more than 99% of the total gene diversity (HT) can be attributed to individual variation within the population. Genetic admixture analysis shows the predominant influence comes from the Spanish, a lesser contribution from Amerindians and a slight one from the West Africans. The contribution of the ancestral population to various subpopulations of the Mexican-Americans of Starr County is similar. The Mexican-Americans of Starr County are similar to the Mexican population from northeastern Mexico. The history of admixture is apparently old enough to have brought the entire Mexican-American gene pool to Hardy-Weinberg equilibrium. There is no non-random association of alleles among the genetic marker systems considered in the present study, in spite of the fact that this population is of admixed origin. These results, in aggregate, suggest genetic homogeneity of the Mexican-Americans of Starr County, Texas, and point towards the utility of this population for genetic and epidemiological studies.

Juxtaposed short sequence repeat types and haplotypes near exon 3 of the insulin receptor locus among Mexican Americans.

The insulin receptor has been sequenced on numerous occasions and reports suggest several potential polymorphisms, as do a number of reports of single base changes. Examining these reports identifies five potential polymorphisms at or near exon 3. Three of these--codon 233 (CTG to CCG), codon 234 (GAC to GAT), and codon 276 (CAG to CAA)--predict restriction site differences. Just 5' of exon 3, the sequence suggests the presence of two short sequence repeats (SSRs), one with ATTT repeats and one with TC dinucleotide repeats. Amplification of exon 3 using the polymerase chain reaction followed by appropriate restriction digestion demonstrated no variation in a sample of 50 Mexican Americans. The codon 276 results were surprising given several reports showing the putative differences. An additional 91 mixed samples were examined and no variation was detected, suggesting that the reported differences likely resulted from sequencing artifacts. Amplification of a smaller fragment demonstrated 10 phenotypes and 7 alleles for the SSR region. Digestion with MnlI permitted scoring each motif separately and when coupled with the uncut results permits unequivocal classification of haplotypes without familial data. These juxtaposed SSRs should be useful for linkage analysis and investigations of gene structure and evolution.

Confirmation of anti-HCV EIA reactivities by RIBA and neutralization assay among blood donors and patients with chronic liver disease and hepatocellular carcinoma.

The aim of our study was to confirm by Recombinant Immunoblot Assay (RIBA) and by neutralization assay the repeat positive reactions found by two commercially available EIAs (Ortho and Abbott) when testing samples from volunteer blood donors, patients with chronic liver disease and with hepatocellular carcinoma. Our data show a high confirmatory rate among patients with chronic viral NANBH and HCC, while among donors and patients with CLD other than NANBH the percentage of presumptive EIA positive reactions confirmed by RIBA and/or neutralization assay is much lower. In our experience, the neutralization assay appears to be somewhat more sensitive than RIBA, especially when samples show low EIA optical densities.

Anti-hepatitis C virus in the elderly: a seroepidemiological study in a home for the aged.

A seroepidemiological survey of anti-hepatitis C virus (anti-HCV) was carried out in 315 institutionalized elderly people. HBV serum markers were tested in the same sera. Clinical details were also studied in the anti-HCV-positive subjects. The overall prevalence of anti-HCV was 2.2%, while the prevalence of HBV serum markers was 36.8% (the HBsAg prevalence was 0.6%). In 1 subject anti-HCV was found in association with HBsAg positivity. Serum transaminase levels were found within the normal range in all 315 subjects (either anti-HCV+ve and anti-HCV-ve), except in the subject who was found to be HBsAg-positive and anti-HCV+ve. In conclusion we found in the institutionalized elderly people a similar prevalence of anti-HCV compared to blood donors of the same geographical area; homes for the aged appear to bring together subjects with previously acquired infections.

Origins of U.S. Hispanics. Implications for diabetes.

The purpose of this article was to characterize the origins of the United States Hispanic population and discuss the implications of these origins in the context of diabetes risk. Particular attention was focused on the genetic origins of the three major U.S. Hispanic groups, i.e., Mexican Americans, Puerto Ricans, and Cubans. The U.S. Census figures provided basic demographic information. Genetic marker data for ancestral populations were taken from a review of the literature and compendia. Genetic marker data for the Puerto Rican and Cuban populations were extracted from the literature. Genetic markers determined on approximately 1000 randomly selected Mexican Americans from Starr County, Texas, were taken as representative of the Mexican-American population. The Hispanic population is the second largest and fastest growing minority in the U.S. Estimates of the Hispanic population in 1988 indicated some 19.4 million residents, of whom 62% were classified as Mexican, 13% as Puerto Rican, and the remaining 25% as Cubans and others. Various lines of evidence can be used to characterize the Hispanic population and its origins. These include ethnohistory, self-assessment of ancestry, surname distributions, speech and cultural characteristics, quantitative traits, and genetic structure. Genetic data were used to estimate the contribution of putative ancestral populations to the contemporary gene pool. For Mexican Americans, 31% of the contemporary gene pool is estimated to be Native American derived, whereas 61 and 8% are Spanish and African derived, respectively. In Puerto Rico, the percentage of contributions of Spanish, Native American, and African admixture to the population are 45, 18, and 37%, respectively. For Cuba, the parallel estimates are 62, 18, and 20%. The high frequency of Native American-derived genes in the contemporary Hispanic population predict a higher frequency of non-insulin-dependent diabetes mellitus (NIDDM) under the assumption that genes are important in NIDDM etiology. Our results are consistent with the finding of the significant role of genes in determining risk.

Changing epidemiology of hepatitis A virus (HAV) infection: a comparative seroepidemiological study (1979 vs 1989) in north-east Italy.

A comparative seroepidemiological study (1979 vs 1989) on HAV infection, was carried out in children and adolescents from North-East Italy. Anti-HAV was tested in 850 subjects 6 to 8 years of age and the results were compared to those observed in 1979, in 462 subjects of the same age range and from the same geographical area. Overall anti-HAV prevalence was 1.9% (ranging from 0.5 to 5.2) in 1989 vs 32.5% (ranging from 7.8 to 70.7) in 1979. This dramatic decline of HAV infection in children and adolescents reflects the improved sanitation standard of our country but, on the other hand, indicates that the number of non-immune adults is increasing, with a higher risk of symptomatic infection in the near future.

Changing pattern of hepatitis B infection in children: a comparative seroepidemiological study (1979 vs 1989) in north-east Italy.

Hepatitis B infection was endemic in Italy and household transmission has been considered to be the main mode of HBV spread. Prevalence of HBsAg positive subjects was therefore higher in children than in adults. Serum samples from 500 children (aged 6-15 year) without overt liver disease were tested for HBV serum markers in 1979. Serological evidence of HBV infection was present in 16% of the subjects. To verify a possible decline of HBV infection we designed a seroepidemiological study in school children from the same town. Three classes of age (6 yrs, 10 yrs, 14 yrs) were selected. Children were recruited from those attending primary and secondary schools using a systematic cluster sampling. After parents' informed consent sera were collected in May 1989. All were tested for anti-HBc: anti-HBc + ve sera were then tested for HBsAg and anti-HBs (EIA Abbott Lab., Chicago, Ill. USA). Of the 1635 children one was HBsAg positive and 21 were positive for any HBV marker. Both the prevalence of HBsAg and that of any HBV marker were significantly lower (p less than 0.001) in 1989 when compared to the corresponding age-class of 1979.