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Biomedical subjects

L Keller

Publications and source records attributed to L Keller.

At least 19 recordsLinked to original sources
PubMed1992

Elastase-type enzymes and their relation to blood lipids in atherosclerotic patients.

Serum elastase-type activity, elastase inhibitory capacity and their relation to lipids were examined in 140 male patients with ischemic vascular disease (coronary, cerebral, peripheral) and in 60 control subjects. In a further 24 patients with acute myocardial infarction elastase activity, inhibitory capacity and lipids during the course of the illness have also been investigated. Serum elastase-type activity was found to be significantly lower and inhibitory capacity significantly higher in the groups of patients than in the controls. HDL- and HDL2-cholesterol as well as apo A concentration showed significant negative correlation with elastase inhibitory capacity both in atherosclerotic and in control subjects. During the course of myocardial infarction a significant elevation of serum elastase-type activity could be observed at the end of the first week; serum triglyceride levels increased, HDL- and HDL2-concentrations decreased significantly in the first 3 weeks, than gradually approached the initial values. In the patients with an elevation of serum elastase-like activity by more than 30% in the first week, there was a significantly higher elevation of serum GOT and LDH1 and a greater occurrence of transmural (Q) infarction than in those with a smaller variation of elastase-like activity.

Adult↗
PubMed1991

[Serum elastinolytic activity and blood lipids in various clinical forms of arteriosclerosis and in acute myocardial infarct].

Serum elastase-type activity, elastase inhibitory capacity and their relation to lipids were examined in 140 male patients with ischemic vascular disease (coronary, cerebral, peripheral) and in 60 control subjects. In further 24 patients with acute myocardial infarction dynamics of elastase activity, inhibitory capacity and of lipids during the course of the illness have also been investigated. Serum elastase-type activity was found to be significantly lower, inhibitory capacity significantly higher in the groups of patients than in the controls. HDL- and HDL2 cholesterol and apo-A concentrations showed significant negative correlations with elastase inhibitory capacity both in atherosclerotic and in control subjects. During the course of myocardial infarction a significant elevation of serum elastase-type activity could be observed at the end of the first week; serum triglyceride levels increased, HDL- and HDL2 concentrations decreased significantly in the first 3 weeks, then gradually approached the initial values. In the subgroup of patients with an elevation of serum elastase-like activity by more than 30% in the first week, there was a significantly higher elevation of serum GOT and LDH1 and a greater occurrence of transmural (Q) infarction than in those with a smaller variation of elastase-like activity.

Arteriosclerosis↗
PubMed1991

A quantitative approach to the characterization of cumulative and average solvent exposure in paint manufacturing plants.

Previous reports have attributed a range of neurobehavioral effects to low-level, occupational solvent exposure. These studies have generally been limited in their exposure assessments and have specifically lacked good estimates of exposure intensity. In the present study, the authors describe the development of two exposure variables that quantitatively integrate industrial hygiene sampling data with estimates of exposure duration--a cumulative exposure (CE) estimate and a lifetime weighted average exposure (LWAE) estimate. Detailed occupational histories were obtained from 187 workers at two paint manufacturing plants. Historic industrial hygiene sampling data for total hydrocarbons (a composite variable of the major neurotoxic solvents present) were grouped according to 20 uniform, temporally stable exposure zones, which had been defined during plant walk-through surveys. Sampling at the time of the study was used to characterize the few zones for which historic data were limited or unavailable. For each participant, the geometric mean total hydrocarbon level for each exposure zone worked in was multiplied by the duration of employment in that zone; the resulting products were summed over the working lifetime to create the CE variable. The CE variable was divided by the total duration of employment in solvent-exposed jobs to create the LWAE variable. The explanatory value of each participant's LWAE estimate in the regression of simple visual reaction time (a neurobehavioral test previously shown to be affected by chronic solvent exposure) on exposure was compared with that of several other exposure variables, including exposure duration and an exposure variable based on an ordinal ranking of the exposure zones.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemical Industry↗
PubMed1991

Serum elastase-type enzymes and their correlation to blood lipids in male patients with atherosclerosis.

Serum elastase-type activity, elastase inhibitory capacity and their relation to lipids were examined in 140 male patients with ischaemic vascular disease (coronary, cerebral, peripheral) and in 60 control subjects. Serum elastase-type activity was found to be significantly lower, inhibitory capacity significantly higher, in the groups of patients than in the controls. HDL- and HDL2 cholesterol as well as apo A concentration showed significant negative correlation with elastase inhibitory capacity both in atherosclerotic and in control subjects.

Apolipoproteins A↗
PubMed1989

Eimeria tenella and E. acervulina: lymphokines secreted by an avian T cell lymphoma or by sporozoite-stimulated immune T lymphocytes protect chickens against avian coccidiosis.

The role of avian lymphokines as nonspecific immunomodulators of host immunity against the intracellular parasite Eimeria was investigated. Prophylactic treatment of normal chickens with crude cell-free supernatants obtained from JMV-1 culture, concanavalin A (Con A)-stimulated normal spleen cells, or sporozoite-stimulated immune T cells prior to inoculation with E. tenella or E. acervulina conferred significant protection. These crude cell-free culture supernatants also inhibited intracellular development of eimerian parasites in vitro. Avian macrophages pretreated with these supernatant preparations showed inhibitory activity against Eimeria. This inhibitory activity could not be ascribed to anti-Eimeria antibody, complement, or cell-free Marek's disease virus and was therefore considered to be due to immunomodulating lymphokines present in the culture supernatants. These results suggest that JMV-1-transformed T lymphoblastoid cells, immune T lymphocytes, and Con A-stimulated normal spleen cells secrete lymphokines that can enhance host immunity in a nonspecific manner and implicate cell-mediated immunity as a major mechanism of the protective host immune response against eimerian infections.

Animals↗
PubMed1989

Methods for the reduction of AIDS social anxiety and social stigma.

A cognitive-social model is proposed for the study of AIDS social attitudes. Features of the ambivalent (fear and compassion) public belief system toward PWAs are outlined and ways to increase altruism and reduce fear are specified. Three studies are reported using cognitive-social methods for the reduction of AIDS social anxiety and social stigma. Study 1 found that cognitive inoculation and abbreviated group desensitization equally reduced AIDS social anxiety measured by a verbal scale. One form of brief group desensitization was superior to basic factual, counterphobic inoculation in reducing desire for social restriction of persons with AIDS (PWAs). In Study 2 subject improvisational role playing of PWAs increased positive attitudes toward PWAs and desire for altruistic actions but did not reduce measured fear. Knowledge of AIDS was negatively correlated with AIDS social anxiety and desire for patient restriction. AIDS social anxiety was negatively correlated with altruism and positively correlated with homophobia. In Study 3, three forms of experimenter-guided mastery imagery reduced AIDS social anxiety and increased AIDS altruism. Results of these studies may have relevance to reducing high-risk contagious behavior, as well as to reducing AIDS social stigma and social anxiety. A componential model of AIDS education is described.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Glycosylation and secretion of acid phosphatase in Schizosaccharomyces pombe.

We have purified secreted acid phosphatase of Schizosaccharomyces pombe. The enzyme is N-glycosylated, the associated carbohydrate accounts for 90% of the total molecular mass and the protein moiety has a molecular mass of 54 kDa. The deglycosylated enzyme still exhibits enzymatic activity. Using antibodies recognizing the protein moiety of the enzyme we have identified two intracellular precursors of acid phosphatase: an unglycosylated membrane-bound 54-kDa form that accumulates in the presence of tunicamycin and a partially glycosylated 72-kDa form that accumulates mostly in membranes of cells grown in rich medium. We further showed that the conversion of the 54-kDa and 72-kDa forms to partially glycosylated and fully glycosylated acid phosphatase is a regulated process. Growth conditions determine how much of translated 54-kDa acid phosphatase is glycosylated to the 72-kDa form and how much remains unglycosylated in membranes. When cells are grown in a rich medium, 5% of the total acid phosphatase protein remains as unglycosylated enzyme and 8% as partially glycosylated 72-kDa form. In cells grown in the minimal medium, however, all of the 54-kDa and 72-kDa forms of acid phosphatase are rapidly processed to fully glycosylated enzyme. The 72-kDa form and the unglycosylated form of acid phosphatase are not secreted or transported to the plasma membrane.

Acid Phosphatase↗
PubMed1984

Elastase-type activity, elastase inhibitory capacity, lipids and lipoproteins in the sera of patients with ischemic vascular disease.

Elastase-type activity and elastase inhibitory capacity were determined in the sera of 130 atherosclerotic patients, suffering from ischemic vascular disease (IVD) localized at various sites, and of 60 control subjects. The concentrations of serum lipoprotein constituents (triglycerides, total cholesterol, HDL cholesterol, apo-A, apo-B) have also been investigated. HDL cholesterol and apo-A levels were decreased at every site on IVD. Plasma HDL concentration in men was lower than that in women. There was a sex-related difference in the elastase-type activity of the sera: within every atherosclerotic group, elastase-type activity in women was significantly higher than in men. Elastase-type activity did not appear to vary with age and did not show any correlation with the concentration of serum lipoprotein constituents. Pancreatic elastase inhibitory capacity of sera was significantly elevated in the sera of atherosclerotic patients. There was a significant negative correlation between the inhibitory capacity and the HDL cholesterol and apo-A content of sera, respectively. Inhibitory capacity did not show sex-, or age-related variation. There was a significant positive correlation between elastase-type activity and elastase inhibitory capacity measured in control sera. In the sera of atherosclerotic patients this correlation could not be established.

Adult↗
PubMed1983

Waste-related cadmium cycle in Switzerland.

The anthropogenic contribution to the global cadmium flux exceeds natural sources by a factor of three. The most important pathway is the atmosphere; therefore, high cadmium concentrations can be found even in remote areas. On a local level, the increase in cadmium consumption can be observed in increasing concentrations in the soil, plants, and food. The question arises as to what extent the soil-plant-man-waste-soil cycle can be loaded with cadmium in order to function without negative impact on the environment. In Switzerland, 120 tons (t) of cadmium are consumed per year. Of this amount, 25 t end up in municipal solid waste, 3 t in wastewater, and 19 t in precipitation and dry fallout. As a consequence of today's waste management practice (75% incineration, 20% sanitary landfill, 5% composting; 75% of all sewage is purified), the annual input to the soil is 40 t: 18 t concentrated in landfills, 19 t dissipated via the atmosphere, and 3 t directly spread via sewage sludge, compost, and fertilizer on agricultural land. If even distribution were possible, the cadmium content of the soil would theoretically double in 150 years. The accumulation in the soil will increase the cadmium content of plants grown on such a soil. According to a simple model, the level of 3 ppm cadmium in soils should not be surpassed. At such concentrations, plants are likely to contain greater than 0.4 mg Cd/kg, a concentration which can cause toxic effects in long-term experiments. The safe level in food might be even lower. In reality, cadmium is not evenly distributed over Switzerland. According to today's practice, it must be assumed that in only 14 years the use of compost will have enriched soils to such an extent that its cadmium content will prohibit the production of food for human consumption. For sewage sludge, this timespan is 130 years. If heavy metal limits in food are to be observed, the input of such metals to the soil has to be limited. In a steady state, the cadmium input to the soil should be equal to its output via plants, leachate, and erosion. This implies that today's dissipative use of cadmium must be stopped.

Air Pollutants↗
PubMed1981

Generalized dermal melanocytosis.

A female infant was born with generalized blue-gray discoloration of the skin. Light microscopy demonstrated the diffuse distribution of dihydroxyphenylalanine-positive, dermal melanocytes. Electron microscopy confirmed the identification of the pigment-bearing cells as melanocytes and demonstrated individual melanocytes to be invested with a filamentous extracellular sheath. To our knowledge, comparable, generalized, dermal melanocytosis has not previously been reported in a newborn.

Female↗
PubMed1979

Diffuse neonatal hemangiomatosis. A case with heart failure and thrombocytopenia.

An examination of the skin in a nine day old infant revealed multiple cherry-red superficial hemangiomas, which progressively increased in size and number. At the age of three weeks these skin lesions involved the scalp, trunk, extremities, palms, soles, and buccal mucous membranes. In addition, similar lesions of the liver and gastrointestinal tract were found. Steroids and irradiation were tried with limited success. Finally, hepatic artery ligation was successful in eliminating the heart failure.

Female↗
PubMed1979

Feedback inhibition of insulin in healthy and overweight subjects studied by use of an artificial endocrine pancreas.

Insulin self-inhibition is still a controversial subject. The majority of data is in favour of an inhibition; however, whether this mechanism is of physiologic relevance in the regulation of insulin secretion is open to discussion. We examined the effect of exogenous insulin on beta cell secretion in 16 volunteers, including 3 who were overweight. Blood glucose (BG) was clamped by means of the dextrose infusion unit of the artificial beta cell, and the secretion of the pancreatic beta cell was monitored by immunomeasureable C-peptide (IMCP) before, during, and after infusion of insulin. The subjects were divided into 3 experimental groups. The inhibition of the basal insulin secretion was examined in group I by clamping BG at the fasting level. The inhibition of the glucose-stimulated insulin secretion was examined in group II by clamping BG at a raised level. The stimulation of insulin secretion by glucose during insulin infusion was examined in group III by stepwise BG rises from the fasting level. An inhibition of the basal insulin secretion was observed in all volunteers examined according to the protocol for group I (n = 9, including 3 overweight volunteers). The lowest insulin infusion rate applied was 1.75 U/h. An inhibition occurred at this low infusion rate corresponding to 44 mu U immunomeasurable insulin (IMI) per ml of serum. However the inhibition was impaired in the overweight participants, who, in addition, were the only ones showing a rebound rise of IMCP after stopping the insulin infusion. An inhibiting effect of exogenous insulin appeared as likely in only 1 of 5 participants examined according to the protocol for group II. Sudden rises of BG abolished the inhibition, while a total or partial inhibition was found at a constantly raised BG level in both participants examined according to protocol III. We conclude that exogenous insulin inhibits beta cell secretion, depending on the BG level, the mode of glucose stimulation, and the time relation between glucose and insulin application. Physiologically occuring IMI levels in peripheral serum were sufficient to cause an inhibition. A disturbance of the negative feedback inhibition of insulin should be discussed as a pathogenetic factor of adipositas.

Adult↗