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Biomedical subjects

E Adam

Publications and source records attributed to E Adam.

At least 91 records · Page 5Linked to original sources
PubMed1994

Standardization of staining in glycosaminoglycan histochemistry: alcian blue, its analogues, and diamine methods.

Glycosaminoglycans are identified in tissue sections by various histochemical techniques including staining with alcian blue and its analogues, such as cuprolinic blue and cupromeronic blue, or with high and low iron diamine methods. The variation in staining results in particularly confusing in the case of alcian blue, where not only are several different brands of alcian blue available but also several different staining protocols are used. If the results obtained by these techniques are compared, they often do not match. We have developed a dot blot technique for quality control of glycosaminoglycan histochemistry to standardize the staining protocols. This staining technique enables histochemists to test particular batches of alcian blue or its analogues for selective glycosaminoglycan staining, thus improving control of histochemical results. The results obtained using the dot blot assay indicate that it is necessary to test each batch of dye individually to obtain valid results in glycosaminoglycan histochemistry.

Acetates↗
PubMed1993

Ondine-Hirschsprung syndrome (Haddad syndrome). Further delineation in two cases and review of the literature.

Two unrelated children with congenital central hypoventilation syndrome (CCHS-Ondine syndrome) and long segment Hirschsprung disease are reported. Patient 1, a girl, is still alive at 3 years. Patient 2, a boy, died of viral pneumonia at 5.5 years. Continuous mechanical ventilation was necessary for months and those children could never be weaned from the respirator during sleep. Seventeen cases of this complex neurocristopathy are reviewed. Only six children (including our cases) survived beyond 2 years of age. Hypotonia, delay in developmental milestones or epilepsy were frequently observed. Ventilator dependency does not improve with time. Multifocal congenital neuroblastoma occurred in two children. Aetiology is unknown.

Abnormalities, Multiple↗
PubMed1993

Neuraminic acid specific lectins as markers of early cortical plate neurons.

Early cortical plate and subplate cells in the developing neocortex of many animal species and humans contain one specific plasma protein, fetuin. Fetuin is heavily glycosylated and it is possible that due to the large amount of sugars, this molecule may play a part in cellular recognition during brain development. Cellular and extracellular carbohydrates in the developing brain of the sheep were studied histochemically using a battery of fluorescein-labelled lectins. Two neuraminic acid specific lectins, Sambucus nigra and Maackia amurensis, labelled consistently the fetuin-positive cells as demonstrated by double labelling with lectins and antifetuin antibodies. Brain sections from other species, known to contain fetuin-positive cells (fetal cow, postnatal tammar wallaby) showed a similar lectin staining pattern to that of the sheep fetus. Additionally, sections from species thought to contain fetuin in their developing brains that failed to cross-react with available antifetuin antibodies (postnatal Monodelphis, fetal cat) also demonstrated lectin-positive staining in the same neuronal cell population. Thus, neuraminic acid is a common and well conserved terminal carbohydrate in cortical plate and subplate neurons of the developing brain. Neuraminic-specific lectins are useful markers for these neurons in addition to the more traditional use of immunocytochemical methods in studies of formation of the neocortex.

Animals↗
PubMed1993

Analysis of lectin binding sites in the gut of hooded Lister rats with special emphasis on recently detected lectins.

Seven recently isolated lectins were tested for their ability to bind to tissue sections of rat gut. Binding sites for N-Acetylgalactosamine specific lectins were found in mucins, in the brush border membrane and in goblet cells. Non-reducing terminal mannose residues were absent from cell surface membranes but were detected in the supranuclear region of goblet cells and enterocytes. The results of lectin binding obtained in this study were generally similar to lectin-gut interactions observed in vivo.

Acetylgalactosamine↗
PubMed1993

Effects of hypophysectomy on galaninergic neurons in the rat hypothalamus.

To understand better the relationship between hypothalamic galaninergic neurons and the pituitary gland, we studied the effects of hypophysectomy on hypothalamic galanin (GAL) content and distribution by radioimmunoassay and immunohistochemistry, and on GAL mRNA by Northern blot analysis. Three weeks after hypophysectomy, performed at 5 or 8 weeks of age, the hypothalamic concentrations of GAL and GAL mRNA were reduced by 30-50% in both male and female rats, compared to age- and sex-matched controls. Similar reverse-phase HPLC retention times of hypothalamic GAL were observed in intact and hypophysectomized rats. The reduction of hypothalamic GAL concentration following hypophysectomy was time-dependent, as peptide levels were unaffected one week after surgery. Immunohistochemistry showed regional differences in the effect of hypophysectomy on galaninergic neurons. In the hypophysiotropic hypothalamus, the scarce GAL immunoreactivity normally observed in the arcuate nuclei was no longer detectable in hypophysectomized rats, and the intense GAL immunoreactivity of the external zone of the median eminence progressively decreased and completely disappeared 3 and 6 weeks after hypophysectomy. In contrast, in the neurohypophyseal system, there was an increase of GAL labelling of the perikarya and emerging axons in the supraoptic and lateral-paraventricular nuclei, 1 and 3 weeks after hypophysectomy, that disappeared 6 weeks after hypophysectomy. An increase of GAL immunoreactivity was also observed in the internal zone of the median eminence 1 week but not 3 weeks after hypophysectomy. We conclude that hypophysectomy reduces the content of GAL and GAL mRNA in the rat hypothalamus. These changes are time-dependent and clearly detected after 3 weeks. The neurohypophyseal and hypophysiotropic galaninergic systems respond differently to hypophysectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Monoclonal antibodies to bovine growth hormone potentiate hormonal activity in vivo by enhancing growth hormone binding to hepatic somatogenic receptors.

Administration of GH complexed with monoclonal antibodies (MABs) potentiates the in vivo actions of the hormone. In particular, growth and serum IGF-I concentrations of GH-treated hypophysectomized rats are increased by concomitant injection of anti-GH MABs. Among 37 anti-bovine GH (bGH) MABs, we selected one MAB with the most potentiating effects to investigate the mechanisms responsible for this phenomenon. Hypophysectomized rats were killed 18 h after a single s.c. injection of bGH (100 micrograms/rat), alone or complexed with increasing doses of MAB (4, 40, 400 micrograms/rat; MAB:bGH molar ratio: 0.005, 0.05, 0.5). IGF-I was measured by radioimmunoassay in acid-extracted sera and livers, whereas liver IGF-I mRNA was quantified by Northern blot hybridization. The in vivo occupancy of liver somatogenic (GH) receptors was derived from the determinations of total and free 125I-labelled bGH binding to liver homogenates treated with 4 mol MgCl2/l or water. Injection of MAB-bGH complexes enhanced body weight gain and raised serum IGF-I, liver IGF-I and liver IGF-I mRNA more than bGH alone (1.6-, 6-, 10- and 7-fold increases at the highest dose of MAB, compared with bGH alone; P < 0.001). These potentiating effects of the MAB were dose-dependent and significant potentiation of the growth response was already observed with the lowest dose of MAB. In vivo occupancy of liver GH receptors was markedly higher 18 h after injection of MAB-bGH complexes than after bGH alone, and this effect was also dose-dependent (receptor occupancy of 28%, 37% and 83% after 4, 40 and 400 micrograms of MAB respectively compared with 6% after bGH alone; P < 0.05, 0.05 and 0.001 respectively). In contrast, the in vitro binding of 125I-labelled bGH to liver homogenates was decreased in the presence of high doses of MAB. We conclude that low amounts of MABs complexed with bGH potentiate the stimulation by the hormone of liver IGF-I synthesis and secretion in a dose-dependent manner. These effects are mediated, at least in part, through changes in hormone-receptor interaction in vivo, leading to enhanced and/or prolonged binding of bGH to its somatogenic receptors.

Animals↗
PubMed1993

Cytomegalovirus and atherosclerosis.

An avian herpesvirus is known to cause atherosclerosis in chickens. The same virus can induce a proliferative disease, malignant lymphoma, suggesting that this agent may also have transforming potential and thus stimulate the proliferation of arterial smooth muscle cells, a prominent feature of atherogenesis. The evidence for involvement of cytomegalovirus (CMV), a member of the human herpesvirus family, in atherosclerosis is much more circumstantial. The finding of CMV antigen and nucleic acid sequences in arterial smooth muscle cells of humans suggests that viral infection of the arterial wall may be common in the general population, including patients with severe atherosclerosis. In seroepidemiological studies, high levels of CMV antibodies were found to be associated with clinically manifest atherosclerotic disease, suggesting that a periodically activated latent infection or a continuously active infection is present in patients with atherosclerosis. Since the viral genome but not infectious virus is found in arterial cells, the artery itself may be the site of CMV latency. Of particular significance is the recent finding that heart transplant recipients, who are immunosuppressed, and who are also actively infected with CMV, are prone to develop accelerated atherosclerosis in the transplanted organ. Although suggestive, these observations by themselves do not demonstrate that viruses have a role in the pathogenesis of atherosclerosis, but they support a working hypothesis of the steps involved.

Animals↗
PubMed1992

A dot blot technique for the analysis of interactions of lectins with glycosaminoglycans.

Glycosaminoglycans are polysaccharides which are widely distributed throughout connective tissue, where they form an essential part of the extracellular matrix. Connective tissue is often stained by lectins, and it is not known whether this staining is due to the interaction of lectins with the glycosaminoglycans or due to the binding of lectins to other glycoconjugates within the matrix. A dot blot technique is presented by which the interaction of lectins with glycosaminoglycans can be analysed.

Glycosaminoglycans↗
PubMed1992

Differential regulation by growth hormone (GH) of insulin-like growth factor I and GH receptor/binding protein gene expression in rat liver.

We have reported that female hypophysectomized (hypox) rats replaced with T4 and cortisone and treated for 7 days with GH injections (4 x 12.5 micrograms/day) had significantly greater growth and increase in serum insulin-like growth factor-I (IGF-I) than did hypox rats continuously infused with GH (50 and 250 micrograms/day), whereas GH binding to liver membranes was increased only by infusion. We now report the effects of hypophysectomy, T4 and cortisone replacement, and the aforementioned continuous vs. intermittent GH treatment on liver IGF-I and GH receptor (GHR)/binding protein (GHBP) gene expression in female rats. Concentrations of IGF-I peptide were measured in acid-extracted sera and liver tissues. Total GH binding to liver membranes was determined in MgCl2-treated homogenates and serum GH binding activity was assessed by gel filtration of serum incubated with 125I-bovine GH. The abundance of messenger RNA (mRNA) transcripts encoding IGF-I, the GHR, and the GHBP was quantified by Northern hybridization analysis of liver poly(A)+ RNA. Hypophysectomy in female animals decreased serum IGF-I and liver IGF-I mRNA concentrations by 95% and 87%, respectively, serum GHBP activity, and total liver GH binding by 50% (P less than 0.001 compared with intact controls), and liver GHR and GHBP mRNA abundance by 30-35% (P less than 0.05 vs. controls). These changes were not reversed by T4 and cortisone treatment. Repeated injections of GH produced a 13-fold increase in liver IGF-I peptide and a 5-fold increase in liver IGF-I mRNA concentrations (vs. saline-treated hypox rats), whereas continuous GH infusions induced only 7-fold and 2-fold increases in IGF-I peptide and mRNA, respectively. Serum GHBP activity was not changed in the GH-injected animals, but rose 2- to 3-fold in the GH-infused rats, an increase similar to that reported for their liver GH binding sites. No major change in liver concentrations of GHR and GHBP mRNAs was seen after repeated GH injections. Differential regulation of the two GHR/GHBP gene products was observed after continuous infusion of GH, with a net 60-70% increase in liver GHBP mRNA abundance contrasting with no apparent change in the GHR mRNA transcript. These results indicate that pulsatile GH administration is more effective than continuous GH infusion in stimulating liver IGF-I gene expression, and this effect is not mediated by an increase in GHR mRNA or protein.(ABSTRACT TRUNCATED AT 400 WORDS)

Analysis of Variance↗
PubMed1992

Vulvar vestibulitis: significant clinical variables and treatment outcome.

The subject of vulvar vestibulitis was reviewed in regard to clinical variables that may be associated with this problem as well as the success of available treatment modalities. Questionnaires were returned by 71 patients diagnosed as having vulvar vestibulitis. Identical information was obtained from a comparison group of individuals with no clinical or physical findings suggesting this diagnosis. A history of recurrent candidiasis and previous condyloma acuminatum were the only variables noted more frequently in patients with vestibulitis. Among the patients treated by perineoplasty, 66% reported complete or significant alleviation of vulvar pain; 78% of the women noted a significant decrease in dyspareunia. Of the patients treated with intralesional interferon, six (50%) reported significant improvement in dyspareunia. Vulvar vestibulitis is a puzzling clinical entity whose etiology is not well understood. Perineoplasty still appears to be the treatment of choice in properly selected individuals.

Adolescent↗
PubMed1991

Seroepidemiology of Helicobacter pylori infection in India. Comparison of developing and developed countries.

Helicobacter pylori (previously Campylobacter pylori) is now accepted as the major cause of type B gastritis and thus what is known about the epidemiology of type B gastritis can reasonably be transferred to H. pylori. We used a specific ELISA for anti-H. pylori IgG to study the prevalence of H. pylori infection in a population of lower socioeconomic class from Hyderabad, India. The results from India were compared to studies from other parts of the world. Two hundred thirty-eight individuals ages 3 to 70 participated. The frequency of H. pylori infection increased with age (P less than 0.01) and was greater than 80% by age 20. H. pylori infection was present in 79% of the population studied; there was no gender-related difference in prevalence of H. pylori infection. IgG antibody against hepatitis A (HAV) was rapidly acquired in Hyderabad; in a subset of 58 children between the ages of 3 and 21 tested, the frequency of anti-HAV was 98.2%. The prevalence of H. pylori infection increases with age in both developed and developing countries. The high age-specific prevalence of H. pylori infection in developing countries is probably a reflection of the lower socioeconomic level of those areas.

Developing Countries↗
PubMed1991

Epidemiology of Helicobacter pylori in an asymptomatic population in the United States. Effect of age, race, and socioeconomic status.

A causative role is now accepted for Helicobacter (formerly Campylobacter) pylori in type B gastritis, and evidence is accumulating that H. pylori infection plays a major contributory role in peptic ulcer disease. Preliminary studies have reported that the prevalence of H. pylori infection increases with age, but detailed information on the prevalence of the bacteria in any defined population and on the factors that may influence the pattern of distribution remains scanty. In the present study, a sensitive enzyme-linked immunosorbent assay and a [13C] urea breath test were used to investigate the prevalence of H. pylori infection among 485 healthy asymptomatic volunteers between the ages of 15 and 80 residing in the Houston metropolitan area. H. pylori infection was present in 52%. The prevalence of H. pylori infection increased rapidly with age at 1%/yr for the overall population. The frequency of H. pylori infection was higher in blacks (70%) than whites (34%) (P less than 0.001); this difference remained after adjustments were made for age, gender, educational level, income, and use of tobacco or alcohol. H. pylori infection was independent of gender but was closely correlated with socioeconomic class. There were significant inverse correlations between age-adjusted frequency of H. pylori infection and income and between educational level and H. pylori infection. There was no association between H. pylori infection and consumption of alcohol or nonsteroidal antiinflammatory drug use or smoking. Having pets was associated with a lower frequency of H. pylori infection, but this was highly associated with higher socioeconomic status. The mode(s) of transmission of H. pylori is unknown, but the social patterns of H. pylori infection are consistent with fecal-oral transmission as one important pathway. Socioeconomic factors seem to determine the age of acquisition.

Adolescent↗
PubMed1991

Transmission of Helicobacter pylori infection. Studies in families of healthy individuals.

Helicobacter pylori is accepted as the commonest cause of type-B gastritis. Detailed information about the mode of transmission remains scanty. We investigated the frequency of H. pylori infection within families, defined as consisting of a husband and wife with at least one biologic child, all living in the same household. Inclusion criteria required that both the parents and the children had been born in the United States, had used no antibiotic or bismuth for the previous 2 months, had no recent major illness or surgical operation, and had no symptoms referable to the upper gastrointestinal tract. H. pylori infection was identified with a 13C-urea breath test and an enzyme-linked immunosorbent assay for anti-H. pylori IgG. Forty-one families (151 healthy individuals) were enrolled. Before the results of the H. pylori tests were known, one parent was selected as the index subject. H. pylori infection clustered; that is, 68% of spouses of H. pylori-infected index subjects were also H. pylori-infected, compared with 9% of spouses of H. pylori-negative index subjects (p less than 0.0001). The children of infected index parents were also more likely to be infected than children of uninfected index parents--40% versus 3%, respectively (p less than 0.0001)--and the results in the children were independent of whether the father or the mother was the index subject. Clustering of H. pylori infection within families suggests person-to-person transmission or common source exposure. The high frequency of H. pylori infection in spouses suggests that genetic factors are less important than living conditions for transmission of H. pylori infection.

Adolescent↗
PubMed1991

Human papillomavirus DNA in tissue biopsy specimens of vulvar vestibulitis patients treated with interferon.

Thirteen women with the diagnosis of vulvar vestibulitis based on clinical symptoms, presence of vestibular tenderness on physical examination, and acetowhite changes of the vulvar vestibule were treated with intradermal injection of alpha-interferon. Biopsies of the acetowhite areas were analyzed for human papillomavirus (HPV) DNA using polymerase chain reaction amplification and dot blot hybridization. Eleven of 13 subjects harbored one of the HPV DNA types; six of these were type 16 and/or 18 and the others were unidentified. Five subjects (all HPV DNA-positive) reported resolution of symptoms with interferon therapy. Our results indicate the presence of HPV DNA in a subset of patients with vulvar vestibulitis, but its presence is not predictive of response to interferon therapy.

Adult↗
PubMed1990

A 268 bp upstream sequence mediates the circadian clock-regulated transcription of the wheat Cab-1 gene in transgenic plants.

We previously reported that the expression of the wheat Cab-1 gene is regulated by an endogenous circadian rhythm and by the photoreceptor phytochrome both in wheat and in transgenic tobacco plants. To define regulatory elements necessary for the circadian rhythm-regulated Cab-1 gene expression, we now analysed the fluctuation of steady-state mRNA levels in a series of 5' deletion mutants in transgenic tobacco plants. We found that the expression of a deletion mutant containing 211 bp upstream sequence still exhibited circadian rhythm. Furthermore we show that an enhancer-like sequence of the Cab-1 promoter (from -357 to -90) can endow a chimaeric gene consisting of a truncated 35S promoter (from -90 to +8) and the bacterial beta-glucuronidase (GUS) gene with circadian clock-regulated gene expression. Finally we demonstrate by nuclear run-off experiments that the transcription rates of the Cab genes in wheat oscillate in a rhythmic manner, with a periodicity of approximately 24 hours. Consistent with our previous findings these results (i) indicate that the expression of the wheat Cab-1 gene is regulated mainly at the transcription level and (ii) identify a short promoter region between -211 and -90 that is responsible for the circadian clock-regulated gene expression.

Amino Acid Oxidoreductases↗