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Biomedical subjects

A Berlin

Publications and source records attributed to A Berlin.

At least 37 records · Page 2Linked to original sources
PubMed1992

Neuroendocrine response to psychological performance testing.

Neuroendocrine changes associated with performance testing requiring sustained attention were assessed in eight normal male subjects. To verify whether the hormonal pattern was modified by chronic stimulation of opiate receptors, eight heroin addicts also were studied. Reaction times were similar in normal and addict subjects. In normal individuals, consistent and significant increases in plasma ACTH and beta-endorphin and in urinary epinephrine and norepinephrine were observed, whereas serum prolactin (PRL) progressively decreased over the testing period. Despite maintained performance capabilities, heroin addicts showed a blunted response of ACTH and a paradoxical decrease in endorphin levels. As the normal subjects, both epinephrine and norepinephrine in urine showed the same significant increase over baseline values. Serum PRL showed a similar trend towards decreased values over the testing period in both groups.

Adrenocorticotropic Hormone↗
PubMed1992

Audit of deaths in general practice: pilot study of the critical incident technique.

OBJECTIVE: To develop and pilot a method for conducting an audit of deaths in general practice by the critical incident technique. DESIGN: Prospective use of the technique within a primary health care team, with the aid of a facilitator, to analyse the events surrounding patients' deaths. SETTING: One inner city academic general practice. PARTICIPANTS: Practice team, comprising general practitioners, trainee, practice manager, practice nurse, and attached health visitor and district nurses. MAIN MEASURES: Identification and classification of critical incidents associated with the case studies of eight recently decreased patients in the practice and subsequent impact on the practice. RESULTS: Among the eight case studies, 57 critical incidents were identified (mean 7.1 per case, range 2 to 15). A failure of communication was the most common factor identified in incidents giving rise to concern, but positive factors in patient care were also identified. Changes in practice included developing protocols for follow up of bereaved relatives and carers and a checklist to ensure completion of administrative follow up tasks resulting from the patient's death; cases of recent deaths and terminally ill patients were reviewed monthly. The practice team found the method acceptable and felt that the discussions had provided useful opportunities for reflecting on their role in patient care. CONCLUSIONS: The critical incident technique fulfils the needs of an audit of deaths in general practice; however, further evaluation based on more cases from different practices is now required.

Cause of Death↗
PubMed1992

Trace elements in dialysis fluids and assessment of the exposure of patients on regular hemodialysis, hemofiltration and continuous ambulatory peritoneal dialysis.

Forty-four elements (Al, Sb, As, Ba, Be, B, Br, Cd, Ce, Co, Cr, Cs, Cu, Eu, Ga, Au, Hf, In, Ir, Fe, La, Lu, Mn, Hg, Mo, Nd, Ni, Pb, Rb, Sm, Sc, Se, Ag, Sr, Ta, Tb, Tl, Th, Sn, W, U, V, Zn, Zr) have been determined in the dialysate for hemodialysis (HD) and fluids for hemofiltration (HF) and continuous ambulatory peritoneal dialysis (CAPD). Multiple determinations have been performed for each dialysis fluid. Several trace elements (TE) showed remarkably elevated average levels; moreover, different bathes of the same commercial product may present a wide variability in TE concentration. The data point out the pivotal role of dialysis fluids in contributing to TE imbalance in dialysis patients and allow the assessment of the potential element exposure of patients on regular dialytic treatment. Patients on HD treatment would be exposed on a weekly basis to milligrams of Al, B, Ba, Br, Cu, Fe, Ni, Pb, Rb, Sr and Zn; on HF, the highest exposures are due to Al, B, Br, Fe, Pb and Zn; on CAPD to B, Br, Fe and Zn. The weekly exposure for several TE appears to be 50- to 12,000-fold higher than the corresponding values on the amount absorbed via the diet (HD: Au, Ba, Be, Ce, Ga, La, Sc, Ta, Th, V, Zr; HF: Be, Ce, Ta, Th, V, Zr; CAPD: Au, Be, Ce, Ga, V, Zr).(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodialysis Solutions↗
PubMed1992

Long-lasting impairment of neuroendocrine response to psychological stress in heroin addicts.

Performance in a vigilance task and the associated neuroendocrine changes during the performance in the task were examined in healthy subjects and in three groups of male heroin-addicts both before undergoing rehabilitation programmes and at various intervals from withdrawal (5 days, 1 to 2 mon, and 3 to 48 mon, respectively). Plasma levels of ACTH, beta-endorphin (EP) and prolactin (PRL) were measured every 10 min before and during performance. In drug addicts, simple reaction times never showed any significant difference as compared to control values. Despite similar baseline levels, ACTH exhibited a markedly depressed response to psychological testing in drug-addicts as compared to controls. Whereas a three-fold increase in ACTH was observed in 'normal' subjects during the performance (from 17 to 54 ng/l), mean values from drug-addicts remained unchanged. EP levels showed a wide scatter of individual values and inconsistent time courses over performance testing: after short-term abstinence, EP showed a three-fold increase over baseline control values but, contrary to what seen in 'normal' subjects, no changes over time were recorded. After long-term abstinence, basal EP was close to control values, but its increase during the testing period was still blunted. PRL levels decreased over the testing period both in controls and in heroin addicts. Thus, despite the lack of obvious signs of neurotoxicity, drug abusers show neuroendocrine changes consistent with a long-lasting selective impairment of the hypothalamic modulation of pituitary secretion.

Adrenocorticotropic Hormone↗
PubMed1990

Pulmonary compliance: early assessment of evolving lung injury after onset of sepsis.

We compared the sensitivity of dynamic (Cdyn) and static lung compliance (CL) with indicators of permeability injury in a model of septic porcine adult respiratory distress syndrome. Two groups of anesthetized ventilated swine (15-25 kg) were studied. Septic animals (Ps, n = 13) received Pseudomonas aeruginosa intravenously for 1 h, which resulted in severe adult respiratory distress syndrome. Controls (C, n = 13) received 0.9% NaCl. Cdyn, CL, bronchoalveolar lavage for protein estimation, and thermal cardiogreen extravascular lung water (EVLW) measurements were performed in seven C and eight Ps animals. Six C and five Ps animals underwent gamma camera measurement of lung-to-heart ratio (slope index) of 99Tc-labeled human serum albumin. Both Cdyn and CL decreased significantly (P less than 0.01) at 30 min and thereafter in Ps vs. C. EVLW, slope index, and bronchoalveolar protein content increased significantly (P less than 0.05) in Ps vs. C at 120, 150, and 300 min, respectively. Cdyn and CL decreased well before onset of permeability injury. These early changes may be due to release of vasoactive mediators and sequestration of neutrophils in the pulmonary capillaries and later to increases in EVLW. Measurement of Cdyn and CL represents an early means of assessing evolving lung injury in this acute septic porcine model.

Animals↗
PubMed1989

Salts as a source of metals in dialysis fluids: an assessment study by means of neutron activation analysis.

Thirty-nine trace metals were determined by neutron activation analysis (NAA) in nine salts (glucose, NaCl, KCl, CaCl2, MgCl2, Na-lactate, Na-acetate, NaHCO3 and NaOH), from different European producers, used in the preparation of dialysis fluids. Metal concentrations vary widely from less than 1 ng g-1 to several micrograms per gram. The data are used to assess the potential metal contribution of the salts to a hypothetical dialysis fluid. A comparison of these calculations with NAA of commercial haemodialysis solutions, and water used for their preparation, suggests that salts are the main source of metal contamination of the dialysate. Despite this, the chemical purity of the salts analyzed is considered to be good and it would be unrealistic to expect a clearly better chemical quality on a commercial scale. In order to protect the health of dialysis patients against abnormal metal exposure, toxicological research directed towards the estimation of the effective daily metal exposure and the determination of possible metal overloads in dialysis patients is necessary. A standardization of the dialysis systems actually used is also an important aspect if uncontrolled metal contamination of the dialysis fluid is to be avoided.

Humans↗
PubMed1988

Preventing percutaneous absorption of industrial chemicals: the "skin" denotation.

Percutaneous absorption has received comparatively little attention in occupational health, although this route of entry has repeatedly caused occupation-related intoxications. In practice, the evaluation of skin penetration rates is far from simple. Much evidence has been obtained from studies of chemicals used for cosmetics and topical therapeutics, but the information available on compounds encountered in occupational health is limited. The data obtained from experimental studies have confirmed that the concentration, type of vehicle, skin area, skin condition, and extent of occlusion are important factors in determining the degree of percutaneous absorption, but no general model has been developed. Also, too little is known about the basic chemical properties governing the rate of penetration. Thus, prediction is difficult and bound to be rather inaccurate. Current preventive practice follows the procedure used by ACGIH and is mainly based on a "skin" denotation in official listings of chemicals to which exposure limits have been allocated. The number of substances and groups of chemicals which have received skin denotation in 17 selected countries varies between 24 and 179 and a total of 275 are listed as a skin hazard in one or more countries; ACGIH lists 143. Thus, the denotation practice varies. As an unfortunate result of these discrepancies and the dichotomy of skin denotation, the absence of skin denotation may erroneously indicate that efforts to protect the skin are unnecessary. Thus, an evaluation of skin penetration potentials should be incorporated in occupational health practice as a supplement to the official denotations.

Humans↗
PubMed1987

Testing of chemicals, safety evaluation and regulation at European Community level.

Regulations regarding safety of chemicals are covered by the following main programmes: health and safety at work, internal market and technical harmonization, environmental and consumer protection. The elaboration of draft Community legislation by the Commission for transmission to Council and the European Parliament requires an evaluation of the scientific data together with a determination of the technical possibilities and economic impact. Studies, scientific committees, national experts and tripartite advisory committees are used. For new chemicals premarketing testing is required for labelling. The testing scheme is described. From the legislative point of view chemical safety is considered essentially in terms of six broad categories: air and water pollution and handling of toxic wastes, classification and labelling of dangerous chemicals and preparations, limitations of use of dangerous substances and preparations, occupational health and safety measures, prevention of major industrial chemical accidents, public health measures related to dangerous chemicals. The classification and labelling of carcinogens and the regulation of the various facets of the use of lead will illustrate these regulatory procedures.

Accident Prevention↗
PubMed1986

[Epidemiology and prevention of occupational health hazards within the European Community].

Since 1978 the European Community has had an action programme on safety and health at work covering all 120 million workers in the Community. On the basis of this programme, directives (instruments of Community legislations) have been adopted by the Council of Ministers and new directives are being drafted. The aim of these directives is to improve safety at work and to protect the health of workers from mechanical, physical, chemical and biological hazards. The drafting of proposals by the Commission for presentation to the Council necessitates detailed and critical examination of the scientific data available, such as epidemiological studies, statistical data and the results of experiments. Epidemiological studies of cases of mesothelioma have led us to propose more stringent limit values for crocidolite than for other asbestos fibres in the air at the place of work. At present, in order to gain a clearer idea of the carcinogenicity of the various compounds of nickel, efforts are being made to collate and update all the epidemiological studies conducted on this subject throughout the world. Finally, particular attention is being paid to the opportunities provided by the anti-poison centres for developing clinical toxicology and epidemiology.

Asbestosis↗
PubMed1985

Reliability of urinary creatinine as a parameter used to adjust values of urinary biological indicators.

The values of biological indicators used in biological monitoring are usually determined on spot samples of urine. In order to reduce the variations due to dilution, it is common practice to correct the values according to reference parameters, such as urinary creatinine concentration and specific gravity. The aim of the present study was to verify whether creatinine possesses the necessary characteristics for adjustment. The levels of creatinine were not influenced by diuresis, but, contrary to what was expected, the values of the metabolite showed marked intra- and interindividual variations. These data raise serious doubts as to the validity of creatinine as a parameter that can be used for adjustment purposes, and suggest that it would be advisable to ascertain for each biological indicator whether in fact adjustment is of any use. Lastly, since there was only a slight correlation between creatinine levels and specific gravity values, it is concluded that these two parameters cannot be used indifferently for adjustment.

Adult↗
PubMed1985

Problems concerning the usefulness of adjustment of urinary cadmium for creatinine and specific gravity.

A previous study concluded that there are some doubts as to the validity of creatinine as a parameter for adjusting the values of biological indicators determined on spot samples of urine, since it is subject to marked inter- and intraindividual variations. Furthermore, since there was only a moderate correlation between creatinine levels and specific density, it can be assumed that these two parameters cannot be used indifferently for adjustment. Nevertheless, it seemed advisable to verify whether correction of cadmium values determined from spot samples offers any practical advantages. For this purpose, 105 subjects with occupational exposure to cadmium were examined. They collected their 24-h urine and spot samples separately at 8.00 h. There was a close correlation between CdU/spot samples and CdU/24 h. The correlation index was very similar both for CdU/spot values expressed in microgram/l and for values adjusted according to creatinine or 1024 specific gravity. These results show that no particular advantages are offered by adjusting CdU according to creatinine or specific gravity.

Adult↗
PubMed1982

[Subvesicular obstruction in the girl and the female. 2. Therapy].

Treatment of subvesical obstructions in girls and women is indicated by specific clinical symptoms and secondary changes in the upper urinary tract. Relative urgency in time should be decided by urodynamic measurement of quantitative severity of the given voiding disorder. - In cases of distal urethral stenosis, good results proved to be obtainable from dilatation and urethrotomy. Hormonal treatment and chemotherapy may be used as flanking approaches. Conservative action should be given priority for all forms of neuromuscular bladder outlet obstructions. Several groups of pharmaceuticals are available for conservative treatment, once causes have been elucidated. In patients the micturitional disorders due to faulty micturitional education, growing importance must be attached to methods aimed at positive biofeedback mechanisms. Surgical action comes at the bottom of the therapy list for patients with neuromuscular subvesical obstructions.

Adolescent↗
PubMed1982

[Behavior during the work week of biological indicators of exposure to lead].

The AA. have studied the weekly changes of haematic and urinary parameters of lead occupational exposure. For this aim, they have collected in 14 ceramic workers 3 blood samples for day and all urine samples for day and all urine samples from monday to friday. The PbB and FEP levels did not show significant variations during working week. The measurement of ALA in single urines shows that this parameter is characterized by remarkable fluctuations within the same day in all subjects examined. The correction of values by density gave negative results while the correction by creatinine decreases the daily fluctuations but only in some cases. The execution of test in urine of 24 hours seems to give the most reliable correlation with lead exposure levels because of its relative constancy during week.

Adult↗