Search PubMed⌕ Search

Biomedical subjects

A Sommer

Publications and source records attributed to A Sommer.

At least 181 records · Page 10Linked to original sources
PubMed1994

Biochemical analysis of prostate specific antigen-proteolyzed insulin-like growth factor binding protein-3.

Prostate specific antigen (PSA) has been shown to proteolyze IGFBP-3. However, the cleavage sites and mechanism of proteolysis are unknown. In this study, we proteolyzed recombinant human IGFBP-3 with PSA bound to a solid phase support. The reaction mixture was separated by centrifugation, with PSA remaining in the solid phase and the proteolyzed IGFBP-3 in the aqueous phase. The IGFBP-3 fragments were functionally analyzed by affinity labeling and Western ligand blotting (WLB). Further biochemical analyses were provided by silver staining of total protein and Western immunoblotting (WIB) of immunoreactive fragments with an IGFBP-3 specific antiserum (alpha-BP-3 g1). N-terminal sequence analysis was performed on filter-immobilized IGFBP-3 fragments, following size separation by SDS-polyacrylamide electrophoresis. PSA proteolyzed IGFBP-3 into at least 7 fragments (M(r) of 26 kDa to 13 kDa) as identified by silver staining and WIB. At least 3 fragments were visible by affinity labeling with radiolabeled IGF-I or IGF-II and 4 were weakly visible by WLB. These data indicate that some IGFBP-3 fragments retain their ability to bind IGF. N-terminal sequence analysis revealed at least 5 different proteolytic recognition sites for PSA in IGFBP-3. Three of the 5 sites were consistent with a 'kallikrein-like' enzymatic activity and 2 sites were consistent with a 'chymotryptic-like' enzymatic activity. The chymotryptic activity of PSA was further confirmed by the ability of alpha-1-antichymotrypsin and chymostatin to block PSA cleavage of radiolabeled IGFBP-3.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1994

[CT diagnosis of acute mesenteric vein thrombosis with intestinal infarction].

Imaging methods provide an important diagnostic basis to clarify mesenteric ischemia. Angiography is the definitive method of investigation in such cases. Other noninvasive methods such as ultrasonography, computed tomography, and magnetic resonance imaging must still prove their importance. We describe three cases of unspecific abdominal pain where the CT shows a mesenteric venous thrombosis with an infarcted bowel. The venous infarcted bowel is clearly demonstrated by CT when other signs for MTV such as ascites, bowel wall thickening, bowel dilatation, and pneumatosis intestinalis are present. CT seems to be a good procedure in order to identify unspecific abdominal pain as being caused by a vascular insufficiency.

Adult↗
PubMed1994

The spectrum of "complicated spastic paraplegia, MASA syndrome and X-linked hydrocephalus". Contribution of DNA linkage analysis in genetic counseling of individual families.

X-linked hydrocephalus and the X-linked MASA syndrome (Mental retardation. Adducted thumbs, Shuffling gait and Aphasia) both have a variable clinical spectrum with great overlap. Data from DNA linkage analysis placed the locus for both conditions at Xq28. On clinical and molecular grounds it has been hypothesized that both MASA syndrome and X-linked hydrocephalus are caused by a mutation in the same gene at Xq28. There is no significant clinical marker in the obligate female carriers and prenatal diagnosis by ultrasound is not reliable; DNA analysis can offer an improved genetic counseling for the families and more reliable prenatal diagnosis. In the gene encoding for Ll, a neural cell adhesion molecule and located at Xq28, several different mutations have been reported in X-linked hydrocephalus families and in a MASA family. We report data on DNA linkage analysis in 6 families with X-linked hydrocephalus/MASA syndrome. These data illustrate the importance of DNA linkage analysis in the individual family; they also show, however, the problem of studying small families. Genetic heterogeneity cannot be excluded.

Abortion, Eugenic↗
PubMed1993

Estimation of design effects and diarrhea clustering within households and villages.

The degree to which diarrheal disease clustered within households and within villages among preschool age children was examined using data from four population-based prevalence surveys undertaken in Malawi, Zambia, Indonesia, and Nepal over the past decade. The design effect for each cluster survey was calculated using the diarrhea prevalence, the cluster sizes, and the magnitude of diarrhea clustering within the sampling unit (villages). A recently developed statistical method, alternating logistic regression, was used to estimate disease associations within households of up to nine preschool age children residing within villages of up to 589 such children. Pairwise odds ratios estimating diarrhea clustering within villages ranged from 1.03 (95% confidence interval (CI) 1.01-1.07) in Zambia to 2.19 (95% CI 1.73-2.78) in Indonesia. The design effects ranged from 2.07 (95% CI 1.26-3.19) in Zambia to 7.93 (95% CI 5.16-11.52) in Indonesia. Design effects were strongly dependent on cluster size. The design effects for clusters of size 50 would have ranged from 1.38 to 4.73. Pairwise odds ratios for diarrhea clustering within households ranged from 1.88 (95% CI 1.61-2.19) in Nepal to 10.05 (95% CI 8.46-11.94) in Indonesia. Household odds ratios were always larger than village odds ratios. The village and household pairwise odds ratios adjusted for age, the type of latrine used by the household, and presence of a market in the village were slightly higher than the unadjusted odds ratios. Alternating logistic regression provided useful estimates of disease clustering within villages and household while allowing for covariate adjustment.

Child, Preschool↗
PubMed1993

Occurrence of the Sandifer complex in the Brachmann-de Lange syndrome.

Gastroesophageal reflux is a common occurrence in infancy. The most severe complications of reflux include torticollis, opisthotonus, and paroxysmal dystonic posture (known as the Sandifer complex). We examined 17 patients now ranging in age from 9 months to 19 years (mean age 11 years) with the Brachmann-de Lange syndrome for evidence of gastroesophageal reflux and found that 13 had not only reflux, but also posturing and behavior consistent with the Sandifer complex. We propose that early recognition of gastroesophageal reflux in these patients may prevent the full picture of the Sandifer complex and allow for medical treatment rather than surgical intervention.

Adolescent↗
PubMed1993

Aicardi syndrome, metastatic angiosarcoma of the leg, and scalp lipoma.

An infant girl with Aicardi syndrome, scalp lipomas, and angiosarcoma of a limb is reported. The cavernous hemangioma of the leg was benign when biopsied at age 5 months but became malignant at 11 months. Angiosarcoma caused multiple distant metastases which were evident at autopsy at age 19 months. This is the first case of Aicardi syndrome associated with lipoma and metastatic angiosarcoma.

Eye Abnormalities↗
PubMed1993

Abnormal T-cell subset proportions in vitamin-A-deficient children.

Although vitamin A deficiency in children seems to increase susceptibility to infection and community trials have shown that vitamin A supplementation can reduce childhood mortality from infectious diseases, the underlying biological mechanisms are largely unknown. We conducted a randomised, double-masked, placebo-controlled clinical trial among children in West Java, Indonesia, to determine whether vitamin A deficiency is associated with abnormalities in T-cell subsets and whether vitamin A supplementation affects T-cell subsets. We studied 55 children aged 3-6 years--30 with xerophthalmia and 25 without. Acutely malnourished children (< 80% of reference weight-for-height) were excluded. CD4/CD8 ratios and the proportions of circulating CD4 naive, CD4 memory, CD8, CD45RA, and CD8, CD45RO T-cell subsets were measured. Children with xerophthalmia had lower CD4/CD8 ratios (p < 0.08), lower proportions of CD4 naive T cells (p < 0.03), and higher proportions of CD8, CD45RO T cells (p < 0.04) than those without xerophthalmia. 26 children were given vitamin A supplementation (60 mg retinol equivalent) and 29 received placebo. 5 weeks later the vitamin A group had higher CD4/CD8 ratios (p < 0.001), higher proportions of CD4 naive T cells (p < 0.01), and lower proportions of CD8, CD45RO T cells (p < 0.05) than the placebo group. Vitamin-A-deficient children have underlying immune abnormalities in T-cell subsets and these abnormalities are reversible with vitamin A supplementation.

Analysis of Variance↗
PubMed1993

Vision change and quality of life in the elderly. Response to cataract surgery and treatment of other chronic ocular conditions.

OBJECTIVE: Evaluation of health care in older populations has increasingly focused on quality of life as a critical outcome of treatment. Vision is assumed to be central to functioning. Data suggest that aging, in itself, is associated with a decline in visual functioning, which, in turn, is related to a decline in physical and mental functioning. Other studies indicate that cataract surgery is followed by significant improvement in vision and visual function. Our objective was to test these assumptions. DESIGN: Prospective study of 1021 patients, consecutively drawn from 76 randomly selected ophthalmologists' offices in three cities. Structured interviews were completed at baseline, 2 months, and 1 year after entry. PATIENTS: Six hundred thirteen patients with cataracts and 408 other ophthalmic patients drawn from the same offices but treated for other chronic ocular disorders. All received refractive services as needed. SETTING: Patients from three cities (Baltimore, Md, St Louis, Mo, and San Diego, Calif) were interviewed once in their homes and twice by telephone. INTERVENTIONS: The study involved the measurement of the effects of usual treatment for cataracts and other degenerative eye diseases. MAJOR OUTCOME MEASURES: Visual, social, and psychological functioning. RESULTS: Within 1 year of treatment, change in visual function was accompanied by significant changes, in the same direction, in quality of life functions: night-time driving, daytime driving, community activities, home activities, mental health, and life satisfaction. In addition, the patients with cataracts showed significantly greater improvement in measures of vision than did the noncataract group. CONCLUSIONS: Regardless of treatment, improvement across quality of life functions occurred when visual function improved. Thus, many types of functional degeneration observed in older populations, attributed to a decline in vision, can be slowed, or even reversed, when visual function is improved. Cataract surgery was effective in improving vision and quality of life functions.

Aged↗
PubMed1993

Inequivalence of fluorescent choline and ethanolamine phospholipids in the erythrocyte membrane: fluorescence lifetime determination in the frequency and time domain.

The fluorescence decay of 1-palmitoyl-2-diphenyl-hexatrienyl-propionyl-sn-glycero-3-phosphocholine and the respective ethanolamine derivative were determined in human erythrocyte ghost membranes by phase and modulation fluorometry. The obtained bimodal distribution decay model could independently be confirmed by pulse fluorometry and data analysis by the exponential series method. Distributional widths of labeled choline and ethanolamine phospholipids were different in ghost membranes but identical in phospholipid vesicles. Thus, it is concluded that both lipid classes containing the same fluorophore experience environments of different heterogeneity in the biological system.

Erythrocyte Membrane↗
PubMed1993

Development of rumen metabolism and ruminal epithelium in lambs.

The concentrations of volatile fatty acids and the development of rumen epithelium and microflora adhered to rumen wall in suckling lambs were observed. Total VFA concentration increased with age. The differences between the 1st (28.5 mmol.l-1) and 4th week of age (78.7 mmol.l-1) and between 6th (82.1 mmol.l-1 and 10th week of age (117.4 mmol.l-1) were significant (p < 0.01). The highest molar proportion of acetic acid (71.2 mol%) was observed in 1 week-old lambs and the highest molar proportion of propionic acid in 6 week-old lambs (20.8 mol%). Length and surface characteristics of papillae changed dramatically over the 10-week period. In samples from 1-week and 4-week-old lambs, the papilla surface was relatively smooth and epithelial cells were relatively thin and flat. In samples from 6-week and 10-week-old lambs the tissue topography was typically rough. In the 1-week-old lambs the cocci, single rods and short rods in pairs were present at very low population levels. At 4 weeks the epimural community became notably more complex and bacteria were present at a higher population level. The dominant morphotype at 6 weeks was a rod-shaped end-on attached bacterium. The epimural microflora became the most complex at 10 weeks.

Animals↗
PubMed1993

Influence of Avotan on the microflora and concentrations of ammonia and volatile fatty acids in the rumen.

The influence of Avotan (Firm Cyanamid) was studied on VFA concentration, pH, dynamics of NH3 and on numbers of chosen species of rumen microorganisms in physiological experiments with four young bulls and two wethers with rumen cannulas. It was found no marked physiological change in pH of rumen fluid under the influence of Avotan. Difference between groups were statistical significant. Avotan caused significant (P < or = 0.01) decrease of molar % of acetic acid (from 67.0 to 62.1) and an increase of propionic acid (from 16.41 to 28.21 mol %) in wethers. These changes were nonsignificant with bulls. The acetate: propionate ratio decreased significantly from 4.1 to 2.2 in wethers. Avotan decreased highly significantly (P < or = 0.01) the level of NH3 in the rumen fluid during the observed period (0, 1.5, 3, 4.5 and 6 hours after feeding) in bulls. It was observed the similar effect in wethers 3 hours after feeding (from 170 mmol to 81 mmol/l). Decrease of the total number of microorganisms in the rumen fluid was observed in animals which received Avotan (on the average 3.5 times in young bulls, and 4.5 times in wethers). The number of enterococci decreased significantly (2.8-4.5 times), number of amylolytic bacteria decreased less significantly.

Acetates↗
PubMed1993

The effect of diet composition on the development of rumen digestion in lambs.

The effect of composition of feed concentrate on the development of rumen digestion in suckling lambs was investigated. The experimental group of lambs was offered special concentrate diets (SCD I and SCD II), which, compared to routinely produced commercial mixtures CCD 1 and CCD 2, were completely cleared of milk protein, enriched with legumes and alfalfa meal and supplemented with cut alfalfa of the particle size 1 cm. Significantly higher concentrations of total volatile fatty acids (VFA) were recorded in experimental lambs at the age of 7, 9 and 11 weeks. The highest concentration of total VFA was observed at the age of 11 weeks (118.2 mmol.l-1 in the experimental group and 110.2 mmol.l-1 in the control group). The cellulase activity (endoglucanase E.C.3.2.1.4. and cellobiohydralase E.C 3.2.1.91.) of the rumen content of experimental lambs was significantly higher at the age of 9, 11 and 15 weeks, in comparison with the control animals, reaching the highest values at 11 weeks of age (19.32 micrograms.ml-1 in the experimental group, 15.84 micrograms.ml-1 in the control group), while the increase of number of cellulolytic bacteria in experimental lambs was insignificant. Scanning electron microscopy showed more pronounced colonization of the rumen epithelium by adherent rumen microflora in experimental lambs. Average daily weight gains over the whole investigated period reached 0.235 kg in the experimental group and 0.221 kg in the control group.

Animal Feed↗
PubMed1993

[Effect of growth rate of lucerne on the degradability of crude protein in the rumen and on in vitro digestibility of non-degraded crude protein].

The influence of growth rate of lucerne was investigated on the content of crude protein, NDF, ADF and the in situ degradability of crude protein and organic matter in the rumen of bulls. The content of crude protein decreased significantly (P < 0.05) with the increasing growth rate of lucerne, simultaneously the part of soluble N as per cent of total N decreased also. The effective degradability of crude protein decreased about 10% and the same value of organic matter about 5% in relation to the increasing content of NDF and ADF (P < 0.01) in dependence of the increasing growth rate of lucerne. The digestibility of non degraded crude protein in the rumen was investigated in vitro with pepsin, trypsin and chymotrypsin. The highest value resulted with 75.0% digestibility for this crude protein fraction in the stage of the start of flowering of lucerne.

Animal Feed↗
PubMed1993

Clustering of xerophthalmia within households and villages.

The clustering of xerophthalmia within households and villages was estimated among preschool age children using data from studies conducted in Malawi, Zambia, Indonesia and Nepal over the past decade. Pairwise odds ratios (OR) were used to measure the magnitude of clustering. This OR measures the risk of xerophthalmia for a preschool child given that another randomly chosen preschool child from the same household (or same village but different household) had xerophthalmia, relative to the risk if that randomly chosen preschool child did not have xerophthalmia. Village pairwise OR ranged from 1.2 in Malawi to 2.2 in Nepal. Household pairwise OR ranged from 4.4 in Malawi to 9.7 in Indonesia, indicating that xerophthalmia clustering was much greater within households than villages. The magnitude of this clustering was as large, or larger than, infectious outcomes such as diarrhoea, fever and cough. Although xerophthalmia was associated with a weekly history of infectious morbidity, the clustering of diarrhoea, fever and cough explained very little of the xerophthalmia clustering observed in each of these studies, Hence, other household factors such as food availability and dietary practices should be examined for their role in the clustering of xerophthalmia within certain households.

Child, Preschool↗
PubMed1993

Vitamin A, infectious disease, and childhood mortality: a 2 solution?

Vitamin A was first discovered in 1913. Its deficiency was soon associated in animal models and case reports with stunting, infection, and ocular changes (xerophthalmia) resulting in blindness. The ocular consequences dominated clinical interest through the early 1980s. A longitudinal prospective study of risk factors contributing to vitamin A deficiency and xerophthalmia revealed a close, dose-response relationship between the severity of mild preexisting vitamin A deficiency and the subsequent incidence of respiratory and diarrheal infection (relative risk [RR], 2.0-3.0) and, most dramatically, death (RR, 3.0-10.0). Subsequent community-based prophylaxis trials of varying design confirmed that vitamin A supplementation of deficient populations could reduce childhood (1-5 years old) mortality by an average of 35%. Concurrent hospital-based treatment trials with vitamin A in children with measles revealed a consistent reduction in measles-associated mortality in Africa of at least 50%. It is now estimated that improving the vitamin A status of all deficient children worldwide would prevent 1-3 million childhood deaths annually.

Africa↗
PubMed1993

A priming dose of oral vitamin A given to preschool children may extend protection conferred by a subsequent large dose of vitamin A.

A randomized trial tested whether a priming dose of vitamin A would extend the protection of a subsequent 60,000-micrograms retinol equivalent (RE) oral dose. Seventy-five xerophthalmic and 74 age- and neighborhood-matched non-xerophthalmic preschool children were randomized to one of three oral regimens of vitamin A, receiving peanut oil only (Group A), 7500 micrograms RE (Group B) or 60,000 micrograms RE (Group C), followed in all instances by 60,000 micrograms RE 1 wk later. Serum retinol was measured 2, 4, 6 and 12 mo following the second dose by technicians unaware of the children's treatment status. Among xerophthalmic children, mean values differed across treatment groups at 2 mo (C > A) and tended to be different at 12 mo (C > A and B > A). Among non-xerophthalmic children mean retinol concentrations differed across treatment groups at 6 mo, but not in a consistent way (A > C > B), and at 12 mo (C > A and B > A). Xerophthalmic children reverted to biochemical deficiency faster than non-xerophthalmic children. A small or large priming dose may extend the protection conferred by a 60,000-micrograms RE dose, supporting the use of repeated, spaced doses of vitamin A for treating xerophthalmia. Similar retinol concentrations in Groups B and C at 12 mo suggest the 60,000-micrograms RE prophylactic dose currently recommended by the World Health Organization need not be increased.

Administration, Oral↗