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Biomedical subjects

B Sangster

Publications and source records attributed to B Sangster.

At least 37 records · Page 2Linked to original sources
PubMed1989

The role of Poison Control Centers in radiation accidents.

In the days after the nuclear reactor accident at Chernobyl (USSR) in April 1986, the Dutch Poison Control Center had to answer questions concerning possible health effects caused by (over)exposure to ionizing radiation. These questions were similar to questions asked regarding exposure to toxic agents after chemical accidents. It is obvious that the experience and practical approach of a Poison Control Center in handling toxicological problems can be used in problems concerning ionizing radiation.

Accidents↗
PubMed1988

Poison Control Centre and environmental pollution health care and risk assessment.

In the past two decades several incidents of environmental pollution have become known in which people might have been exposed to the contaminating substances. In the Netherlands the National Poison Control Centre, a department of the National Institute of Public Health and Environmental Protection, plays a distinct role in dealing with the health problems arising from these incidencts. The health risk assessment of an environmental incident may be facilitated by utilizing a logical predetermined sequence of decision steps in order to avoid inappropriate responses which could induce many untoward effects within the population of the contaminated area. As an example of this general approach, the handling of a recent incident with mercuric chloride is described.

Environmental Exposure↗
PubMed1988

The use of atropine and oximes in organophosphate intoxications: a modified approach.

Usually intoxications with cholinesterase inhibitors are treated with large dosages of atropine. Furthermore oxime treatment, if applicable, is generally discontinued after one to two days. Two cases of severe anticholinesterase intoxication are presented. In both cases administration of oximes were part of the treatment. The first patient showed relapse cholinergic symptoms when administration of oximes was stopped after one day. In the second patient, where oximes were administered continuously during six days, no relapse cholinergic symptoms occurred. Based on pharmacological as well as on toxicokinetic considerations, and supported by animal experimental data, a continued oxime treatment, if appropriate, can be advocated, whereas the use of atropine should be minimized.

Adult↗
PubMed1988

Skin lesions due to exposure to methyl bromide.

Six patients were occupationally exposed to high concentrations of methyl bromide during a fumigation procedure using adequate airway protection. Within a few hours all patients developed skin lesions, consisting of sharply demarcated erythema with multiple vesicles and large bullae. There was a striking predisposition for parts of the skin that were relatively moist or subject to mechanical pressure, such as axillae, groin, and abdomen. Microscopically, early skin lesions revealed necrosis of keratinocytes, severe edema of the upper dermis, subepidermal blistering, and diffuse infiltration of neutrophils and, to a lesser degree, eosinophils. Two patients developed an urticarial rash approximately one week after the exposure. On histologic examination, these late lesions showed combined features of a spongiotic dermatitis and urticaria. No immunopathologic manifestations were observed. In all patients, the skin returned to normal after four weeks, except for some residual hyperpigmentation. Plasma bromide levels after exposure strongly suggested percutaneous absorption of methyl bromide.

Administration, Topical↗
PubMed1988

Acute intoxications during work.

Information on acute intoxications during work in the Netherlands has been gathered from 4 sources during a 1-year period: 1. The registration of occupational accidents of the Directorate-General of Labour, by reviewing reports on accidents involving chemicals; 2. The Netherlands Poison Control Centre of the National Institute for Public Health and Environmental Hygiene, by tracing back consulting physicians; 3. The Dutch Centre for Health Care Information, by searching their data base for hospital admissions with relevant admission diagnoses and 4. A large Occupational Health Service, which for this purpose recorded incident cases in the population under care. During the period of investigation 5 deaths were reported: 1 case of hydrogen cyanide intoxication, 1 case of carbon dioxide intoxication, and 3 cases of hydrogen sulfide intoxication in combination with oxygen deficiency (nearby a liquid manure tank). At least 690 (supposed) acute intoxications during work occurred, which in 84 cases resulted in hospital admission. The total number of hospital admissions for supposed unintentional acute intoxications by chemicals, usually encountered in workplaces, in the Netherlands in 1984 was at least 477. Substances most often involved belonged to the groups of pesticides, lung and/or skin irritant liquids/vapors/gases and asphyxiants. The working branches most often involved were agriculture and market gardening sectors, (chemical) industries, repair and retail trade and some governmental services (police, fire brigade, defense personnel). The results show considerable underreporting in official statistics on acute intoxications during work.

Female↗
PubMed1987

Central origin of respiratory arrest in beta-blocker intoxication in rats.

Propranolol HCl (7.5 mg X kg-1), timolol maleate (7.0 mg X kg-1), and sotalol HCl (10 mg X kg-1) were administered intracerebroventricularly (icv) to spontaneously breathing (SB) rats. The respiratory rate declined until the rats all died from respiratory arrest. Artificial ventilation resulted in survival of the rats for a 3-hr observation period. Intravenous (iv) administration of the same doses of the three beta blockers to SB rats did not result in either respiratory depression or death. Except for a decrease in heart rate (HR) the hemodynamic and respiratory parameters remained almost constant during the 3-hr observation period after iv administration to SB rats. After icv administration to SB as well as to ventilated rats no significant differences could be observed in the initial decrease in HR in comparison with iv administration. In SB rats at the end of the experiments a further decrease in HR was observed which might be ascribed to hypoxia since it did not occur in ventilated rats. After icv administration of each drug to the ventilated rats, mean arterial blood pressure showed a significantly greater decrease at the end of the 3-hr observation period than after iv administration. Plasma concentrations of the three drugs were determined just before death after icv administration in SB rats. In the other two groups they were measured at mean survival time and at the end of the experimental period. The plasma concentrations showed that the route of administration rather than the concentration of the beta blocker in plasma determines the occurrence of respiratory arrest. It was concluded that an overdose of propranolol, timolol, or sotalol can cause a centrally mediated respiratory arrest. Furthermore, a central mechanism appears to be implicated in the decrease in blood pressure.

Animals↗
PubMed1987

Exposure of the skin to methyl bromide: a study of six cases occupationally exposed to high concentrations during fumigation.

1 The effects of exposure of the skin to high concentrations of methyl bromide were studied in 6 cases, who had been unintentionally exposed. 2 Exposure to high concentrations of methyl bromide (approximately 40 g/m3) for 40 min can lead to redness and blistering of the skin. This cannot be prevented by wearing standard protective clothing. 3 Skin lesions show a preference for relatively moist skin areas. 4 Plasma bromide levels were highest immediately following exposure (mean 9.0 +/- 1.4 mg/l) and fell in subsequent hours (mean 6.8 +/- 2.3 mg/l 12 h after the exposure), suggesting absorption of (methyl) bromide through the skin. 5 No systemic effects were noted in this series. 6 Fumigation with methyl bromide should not be done in such a way as to require the presence of workers inside closed areas, where methyl bromide is released.

Adult↗
PubMed1987

The toxicology of bromide ion.

Inorganic bromide is widely distributed in nature. Its natural physiological role in animal life is unknown. More than a century ago bromide was introduced in medicine as an antiepileptic drug. Nowadays, man is primarily exposed to bromide via food as the result of use of bromide-containing fumigants in intensive horticulture and in the treatment of food stocks. In this review exposure of man to bromide is described, and the pharmacological and toxicological effects of bromide ion are discussed.

Animals↗
PubMed1987

Biocompatibility of hemodialysis using cuprophane membranes.

In a controlled study of the influence of hemodialysis on hemodynamics, complement system, leucocyte- and thrombocyte concentration was studied in two groups of five non-uremic dogs each. During the initial 30 min of dialysis with the commonly used cuprophane membrane, a transient but significant decrease of the mean aortic pressure and cardiac output occurred while simultaneously heart rate and systemic vascular resistance decreased. Thrombocyte concentration decreased significantly during the initial 60 min of dialysis due to sequestration in the dialyzer. Transient leucopenia due to pulmonary leucostasis occurred without decrease of the arterial oxygen tension. The simultaneous occurrence and transient character of the hemodynamic changes, leucopenia and thrombocytopenia suggest a relationship between these phenomena. These results indicate that the biocompatibility of cuprophane dialysis membranes is of importance not only with regard to changes in the leucocyte- and thrombocyte-count but also with regard to hemodynamic changes.

Animals↗
PubMed1986

Biocompatibility of haemoperfusion.

To evaluate the influence of haemoperfusion on haemodynamics, complement system, leucocyte and thrombocyte concentration, a controlled study was performed in three groups of five dogs each. During the first 30 min of haemoperfusion with columns containing cellulose-coated activated charcoal, a significant decrease of mean aortic pressure, cardiac output and stroke volume was observed, while heart rate and total systemic resistance decreased. A comparable phenomenon, although to a much lesser extent, was observed during perfusion using columns containing polystyrene resin. Perfusion with columns containing cellulose-coated activated charcoal caused a significant decrease in total haemolytic complement, indicating activation of the complement system. A significant decrease in the leucocyte and thrombocyte concentration due to sequestration of granulocytes and thrombocytes in the columns was observed during the first 30 min of perfusion in both groups. Pulmonary leucostasis, without decrease of arterial oxygen tension, occurred during perfusion with columns containing cellulose-coated activated charcoal. Both the simultaneous occurrence and the transient character of the haemodynamic changes, complement activation and sequestration of granulocytes and thrombocytes in the perfusion column suggest a relationship between these various changes. The results stress the importance of close monitoring of the haemodynamic parameters of the intoxicated patient, particularly during the early phase of haemoperfusion.

Animals↗
PubMed1986

Calcium interferes with the cardiodepressive effects of beta-blocker overdose in isolated rat hearts.

Propranolol, timolol and sotalol were compared with respect to their cardiotoxic properties in isolated, spontaneously beating rat hearts. Propranolol and timolol induced a dose-dependent decrease in myocardial contractility. A high dose of sotalol had only modest negative inotropic effects. Similar reductions in myocardial contractility were observed in isolated, ventricle-stimulated rat hearts. These observations were similar to those in a previous study in which spontaneously beating and ventricle-stimulated reserpinized rat hearts were investigated. Spontaneously beating rat hearts were perfused with a high-, a normal- and a low-Ca++ medium, each with and without propranolol, timolol and sotalol. Addition of each beta-blocker to a normal-Ca++ medium induced a decrease of myocardial contractility and of heart rate and an increase of AV-conduction time when compared with the drug-free medium. In a high-Ca++ medium containing the same concentration of each beta-blocker, a less pronounced decrease of myocardial contractility was observed. Heart rate decreased and AV-conduction time increased to the same extent as after perfusion with the drug containing normal-Ca++ medium. With respect to the corresponding drug-free medium perfusion with a low-Ca++ medium with each beta-blocker enhanced the decline in myocardial contractility, most pronounced in propranolol and timolol containing media. For propranolol and sotalol the decrease in heart rate and increase in AV-conduction time were similar to the results after administration of the same beta-blocker in a high- and a normal-Ca++ perfusion media. Timolol caused an electromechanical dissociation. It was concluded that in beta-blocker intoxication the negative-inotropic phenomena cannot be explained by an action of the drugs on the beta-receptor since the results in reserpinized and non-reserpinized rat hearts were similar. Other effects have to be responsible for the observed cardiotoxic phenomena. The present results indicate that these phenomena can be influenced by Ca++ and or can be attributed to differences in lipophilicity.

Adrenergic beta-Antagonists↗