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Biomedical subjects

P Werner

Publications and source records attributed to P Werner.

At least 199 records · Page 11Linked to original sources
PubMed1982

Playground injuries and voluntary product standards for home and public playgrounds.

Accidents on home and public playgrounds account for more than 150,000 injuries per year. The Division of Hazard Identification and Analysis in the Bureau of Epidemiology has studied playground injuries. Swings, climbing apparatus, gliders, slides, and seesaws were listed as apparatuses associated with the highest percentages of injuries. Falls to the surface also accounted for a large percentage of injuries. Absorbent surfaces other than concrete or asphalt were recommended to reduce the severity of injuries. In addition to making recommendations on playground surfaces, the Consumer Product Safety Commission has developed voluntary product safety standards for home and public playgrounds. Guidelines for safe playgrounds are discussed as well as suggestions concerning people to contact at local, state, and national levels for advice on playground design and safety.

Accident Prevention↗
PubMed1982

Warning mat to signal air seat cushion failure.

A warning mat that signals partial or total deflation of a pneumatic wheelchair cushion has been developed. The purpose of this device is to prevent pressure sores that occur when an inflatable seat cushion loses air gradually and causes ischial tuberosities of a spinal cord injured patient to "bottom out," ie, to come to rest on the hard wheelchair seat. Resulting ischemic necrosis in this anesthetized area is prevented when localized high seating pressure triggers a pressure sensitive warning mat under the wheelchair cushion to produce a high-pitched audio signal warning the patient to reinflate the cushion or leave the chair. Efficacy of this device has been demonstrated in clinical trials, but prevention of decubiti will need to be substantiated by a long-term controlled study.

Equipment Safety↗
PubMed1981

Studies of the interaction between human transferrin and specific receptors on the trophoblast membrane.

The concept of specific receptors for maternal transferrin on the human syncytiotrophoblast membrane has been generally accepted for many years, but definitive evidence of their existence has been established only recently. In this study, experiments were performed to characterize transferrin receptors further, both on intact membranes and after solubilization. Intact, isolated membrane fragments were examined for transferrin binding, both qualitatively by immunofluorescence and quantitatively by radiobinding. The amounts of ligand bound varied inversely with the quantities of residual maternal transferrin remaining at the time of testing. Scatchard plots revealed that the calculated affinity (K alpha) and the number of receptors increased substantially when transferrin was removed by initial washing with chaotropic agents. After dissociation from the membrane by detergents, occupied receptors largely retained bound transferrin, and transferrin binding by unoccupied receptors was also preserved. The stability of such ligand:receptor complexes was considerably enhanced at pH 5.0, and was apparently unaffected by prior treatment with chaotropic agents. Specific immunoprecipitation of solubilized radioiodinated membrane with rabbit antiserum to human transferrin, followed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate under reducing conditions, indicated a relative molecular mass for the unoccupied receptor of 90,000. These results confirm the existence of high-affinity receptors for transferrin on the trophoblast, and also delineate certain potential pitfalls in studies of their interactions with ligand.

Chemical Precipitation↗
PubMed1981

Nursing care of an osteogenesis imperfecta infant and child.

Because the child with osteogenesis imperfecta is hospitalized in the same setting many times throughout his childhood, the nursing staff become well acquainted with him and his family, and are able to assess the child's and parents' understanding of this chronic debilitating disease. The staff can help them to develop a realistic attitude toward their life and future plans. The family should be encouraged to see that the OI child attends a regular school whenever possible so that their active, excellent minds can develop. The family and child should be assured that an OI child can be educated to become a self-supporting adult.

Child, Preschool↗
PubMed1980

Transferrin binding to peripheral blood lymphocytes activated by phytohemagglutinin involves a specific receptor. Ligand interaction.

Immunohistological studies have indicated that membrane sites binding transferrin are present upon activated human peripheral blood lymphocytes. In this study, we have investigated transferrin uptake in human lymphocytes exposed to phytohemagglutinin (PHA), by quantitative radiobinding and immunofluorescence in parallel. In stimulated lymphocytes, binding was maximal after a 30-min incubation, being greatest at 37 degrees C, and greater at 22 degrees C than at 4 degrees C. Although some shedding and endocytosis of transferrin occurred at 22 degrees and 37 degrees C, these factors, and resulting synthesis of new sites, did not affect measurement of binding which was found to be saturable, reversible, and specific for transferrin (K(a) 0.5-2.5 x 10(8) M(-1)). Binding was greater after a 48-h exposure to PHA than after 24 h, and was maximal at 66 h. Sequential Scatchard analysis revealed no significant elevation in affinity of interaction. However, although the total number of receptors increased, the proportion of cells in which binding of ligand was detected immunohistologically increased in parallel, and after appropriate correction, the cellular density of receptors remained relatively constant throughout (60,000-80,000 sites/cell). Increments in binding during the culture period were thus due predominantly to expansion of a population of cells bearing receptors. Similar differences in binding were apparent upon comparison of cells cultured in different doses of PHA, and in unstimulated cells binding was negligible. Transferrin receptors appear, therefore, to be readily detectable only upon lymphocytes that have been activated.

Dose-Response Relationship, Drug↗
PubMed1980

[Immunoprophylaxis against Marek's disease and its perspectives].

An account is given of the present international position in immunoprophylactic control of Marek's disease. An assessment is made of the method used for immunisation in the GDR. In that context, reference is made to problems for which solutions will have to be found in the long run.

Animals↗
PubMed1979

Reduction of plasma triglyceride concentration by acute stress in man.

Three different forms of stress all resulted in acute reduction of plasma triglyceride concentrations. Pyrogen reactions in two hypertriglyceridemic men resulted in the lowering of very-low-density lipoprotein (VLDL) triglyceride levels by 93% and 73% due to decreased secretion of this lipoprotein into plasma. More modest reductions in plasma triglycerides were observed after 2-deoxyglucose-induced intracellular glucopenia and insulin-induced hypoglycemia. With hypoglycemia, the lowering of plasma triglyceride concentration correlated significantly with the stimulation of urinary epinephrine output (r = 0.86) but with neither the urinary norepinephrine response nor with the increase in plasma immunoreactive glucagon levels. To further test whether these changes in plasma triglyceride levels were mediated via the sympathetic nervous system, hypoglycemia was evoked by insulin in subjects with traumatic spinal cord transactions. Two such subjects, who demonstrated sympathetic stimulation in response to hypoglycemia, had evidence of reduced VLDL secretion into plasma, while in two who had no evidence of an adrenergic response. VLDL secretion was not inhibited. Thus, acute lowering of plasma triglyceride concentrations by certain forms of stress appears to be mediated via the sympathetic nervous system.

Acute Disease↗
PubMed1979

Calculated deposition of inhaled particles in the airway generations of normal subjects.

Detailed regional deposition of inhaled particles in the human lung is calculated for individual airway generations. The calculations are based on Landahl's deposition model as applied to the morphometric lung model of Weibel. We consider primarily deposition patterns of iron oxide particles with diameters ranging between 1 and 10 micrometers, but we also calculate patterns of deposition for bis(2-ethylhexyl) sebacate particles with diameters as small as 0.2 micrometers. We obtain good agreement between predicted values and observed values for alveolar retention of inhaled iron oxide particles with 64 and 20% of total deposition predicted to occur in nonciliated airways for 2- and 5-micrometer particles, respectively. This is compared with 48 +/- 9 and 27 +/- 10% for the measured values. Calculated values for total lung deposition of small bis(2-ethylhexyl) sebacate particles agree well with experimental data. The calculations show a minimum in deposition occurring for particle diameters of 0.5 micrometers, which is in agreement with observations. A calculation of surface concentration of deposited 7.9-micrometer aerodynamic particles reveals a very large concentration occurring at airway generation four. This observation is considered in light of observations that bronchial carcinomas occur in this vicinity of the lung.

Aerosols↗
PubMed1979

Protease inhibitor variants in children and young adults with chronic asthma.

The results of systematic medical histories and pulmonary function tests on 26 children and young adults, 10 with Pi variant alpha1-antitrypsin phenotypes and 16 Pi normals, are reported. These subjects were selected from 57 consecutive patients who had chronic asthma. The incidence of Pi variants was 20.4% among 46 Caucasian subjects (ages seven to 21 years). The Pi variant patients required more bronchodilators and long-term corticosteroid therapy. Among the parents and siblings, 50% of those with abnormal Pi type had chronic obstructive lung disease. Grandparents of the Pi abnormal probands had greater incidence of chronic obstructive lung disease (P less than 0.05). Baseline specific airways conductance and maximal midexpiratory flow rates did not discriminat between the two groups. However, bronchodilator inhalation showed the Pi variant group to be significantly less responsive than the Pi normal group. Pi heterozygous state, particularly Pi MZ, should be considered when a young person with chronic asthma is unresponsive to adequate doses of bronchodilators and needs prolonged use of corticosteroids.

Adolescent↗
PubMed1976

Technetium Tc 99m macroaggregated albumin lung scans. Use in chronic childhood asthma.

Serial roentgenograms and technetium Tc 99m macroaggregated albumin lung scans were done simultaneously in 30 bronchodilator-dependent asthmatic children and young adults during both relative remission and attacks of status asthmaticus. When chest roentgenograms showed air trapping and increased peribronchial vascular marking associated with persistent perfusion defects, the children benefited from further laboratory studies and continuous comprehensive therapy. Serial scans provided information about underperfusion that was not discernible either by roentgenograms or by usual blood gas studies. Also, lung scans are easier to obtain in children with long-standing asthma than are detailed pulmonary tests. In our study, technetium Tc 99m macroaggregated albumin scans showed persistent regional perfusion defects in 20 children wiht chronic asthma during relative remission and exacerbations.

Acute Disease↗
PubMed1976

Dose-related dilatation of airways after inhalation of metaproterenol sulfate.

Studies concerning the ability of an inhaled beta2-agonist to produce dose-related bronchodilatation are conflicting. In five asthmatic, five bronchitic, and five normal subjects, specific airway conductance (Gaw/VL), flow-volume curves, and single-breath nitrogen washout were recorded after noncummulative inhalation of 0.65 mg, 1.30 mg, 1.95 mg, and, in some subjects, 2.60 mg of metaproterenol sulfate. Bronchodilatation appeared to be dose-related and was best assessed by using Gaw/VL; in all but one subject with chronic bronchitis, there was a significant linear relationship between log dose and precent change in Gaw/VL. Measurements of flow rate could demonstrate significant log dose-responses in eight subjects, maximum midexpiratory flow being the most sensitive measurement of flow rate, followed in order by forced expiratory volume in one second, flow at 50 percent of forced vital capacity, peak expiratory flow rate, and flow at 75 percent of forced vital capacity. No log dose-respone curve could be observed by using the single-breath nitrogen-washout technique. This demonstration of significant log dose-responses to inhaled metaproterenol is consistent with the response to drugs acting upon receptors and suggests that patients may benefit from increasing doses of bronchodilators.

Asthma↗
PubMed1975

[Is there a variation of death causes in diabetic patients].

On the basis of the post-mortem records of the Institute of Pathology of the University and District Hospital Rostock taking into consideration the clinical records the cause of 355 diabetics who died in the Rostock clinics from 1956 to 1972 were established and analysed. The results were compared with similar examinations of previous years, in which cases among others we established an increase of the mortality of diabetes and an increase of pyogenic infections and sclerosing vascular diseases as causes of death in diabetics. Special attention is paid to the factors of risk for the development of complications dangerous to life in diabetics and it is referred to the prophylactic and therapeutic consequences, respectively, resulting from this.

Cardiovascular Diseases↗
PubMed1975

Effect of glucose infusion on venous blood levels of immunoreactive proinsulin activity, insulin activity and fat parameters in healthy and protodiabetic subjects.

Concentrations of immunoreactive insulin activity (IRI) and proinsulin activity (IRP), blood glucose, free fatty acids (FFA), glycerol, cholesterol, triglycerides were analyzed in 140 subjects suspect of protodiabetes and 50 healthy persons before, during and after a glucose infusion test (GIT). The protodiabetic subjects were classified into normweight, overweight, obese, hyperlipemic groups with diet or with Regadrin therapy and each of them subdivided into such with normal and such with pathological carbohydrate tolerance. Norm- and overweight subjects with asymptomatic diabetes were characterized by a significant reduction of insulin secretion during both phases. Obese patients with or without hyperlipoproteinemia demonstrated an increased IRI reaction during the late phase of secretion. Carbohydrate intolerance was associated with an enhancement of basal triglyceride levels and a reduced depression of glycerol and FFA during the GIT. There were no differences in fasting or reactive IRP concentrations between healthy and protodiabetic subjects with normal carbohydrate tolerance. In asymptomatic diabetes the IRP levels were increased during the late secretion phase, but the percentage of IRP in total IRI was normal or--in existing high response--significantly reduced in comparison to norm response. The results do not support an enhanced IRP secretion as the cause of carbohydrate intolerance.

Adult↗