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.

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.

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.

[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.

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.

Erythrocyte phosphoglucomutase: a family study of a PGM1 deficient allele.

We have observed a large Mexican American family segregating for a low activity allele at the phosphoglucomutase-1 locus. The deficient allele is detectable by starch gel electrophoresis and by direct activity determination. The presence of the deficient allele in either the homozygous or heterozygous condition is not associated with any other phenotypic finding.

The Multinational Andean Genetic and Health Program. IX. Gene frequencies and rare variants of 20 serum proteins and erythrocyte enzymes in the Aymara of Chile.

Electrophoretic variants at 22 genetic loci in the Aymara, mestizo, and Spanish populations of northern Chile are presented, and their possible role in adaptation to hypoxic environments are discussed. Some apparently unique variants were found.

The Nubians of Kom Ombo: serum and red cell protein types.

Phenotype and gene frequencies are presented for eight polymorphic systems among the Nubians of South Egypt, namely, acid phosphatase, glucose-6-phosphate dehydrogenase, adenylate kinase, 6-phosphogluconate dehydrogenase, esterase D, phosphoglucomutase I, peptidase A, and haptoglobin. Eleven systems, namely, albumin, ceruloplasmin, hemoglobin, lactate dehydrogenase, isocitrate dehydrogenase, phosphohexose isomerase, malate dehydrogenase, peptidase B and C, phosphoglucomutase II, and transferrin were found to be monomorphic. A single electrophoretic variant of phosphohexose isomerase were observed.

The blacks of Panama: their genetic diversity as assessed by 15 inherited biochemical systems.

Panama's black citizens are culturally and historically divisible into two groups, the Spanish-speaking coloniales and the English-speaking anglos or afro-antillanos. Until recently these groups have been geographically as well as culturally isolated one from the other, although both are predominantly of West and Southwest African origin. Assessment of the genetic diversity within-villages and within language groups reveals as much, possibly somewhat more, diversity in 15 inherited biochemical markers within villages and language groups as that which obtains between villages and language groups. A number of rare variants at the 6-phosphogluconate dehydrogenase, lactate dehydrogenase, and esterase D loci were encountered and are described.

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.

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.

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.

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.

The Aymara of Western Bolivia. IV. Gene frequencies for eight blood groups and 19 protein and erythrocyte enzyme systems.

A total of 315 individuals, mainly of Aymara origin, from western Bolivia were examined for genetic variation at eight red cell antigen and 19 serum protein and red cell enzyme loci. The gene frequencies for polymorphic loci and the discovery of several rare variants are discussed in terms of previous work among the Aymara and the closely related Quechua. The effect of inclusion of related individuals in the sample on gene frequency, variance of gene frequency and genetic distance, is discussed.

Effects of the apolipoprotein E polymorphism on levels of lipids, lipoproteins, and apolipoproteins among Mexican-Americans in Starr County, Texas.

Genetic variability has been implicated as a significant contributor to the variation in levels of lipids, lipoproteins, and apolipoproteins (apos) through a variety of direct and indirect investigations. Among the direct investigations, apo E has been shown to be polymorphic and to explain a small but statistically significant proportion of the variability in cholesterol. The apo E polymorphism was typed in 964 randomly selected Mexican-Americans from Starr County, Tex., and its effects determined on levels of cholesterol, triglycerides, total high density lipoprotein (HDL) cholesterol, subfractions (HDL2 and HDL3), alpha- and beta-lipoprotein cholesterol, low density lipoprotein (LDL) cholesterol, and apos A-I, A-II, B, C-II, C-III, and E. Effects are reported for the entire sample and in each of three groups, namely, premenopausal females, postmenopausal women, and males. In the entire sample, significant effects were observed on cholesterol, beta-lipoprotein cholesterol, LDL, apo B, and apo E. There is evidence for significant physiological interaction of the apo E polymorphism effect in females by menopausal status. This is most evident for apo E levels, in which 5.9% of the variability in the entire sample is explained by the apo E polymorphism. In premenopausal females, however, the polymorphism accounts for 27.5% of the variability. In postmenopausal women and males, there is no significant effect. It is shown that the apo E polymorphism can be treated as a two-locus, two-allele system. Doing so identifies substitutions in amino acid position 158 as the mediators of most of the observed effects of this polymorphism.

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.