The dynamics of leukocyte adhesion to the endothelium pial venules under massive blood loss

The dynamics of leukocytes adhesion to brain microvenules endothelium of Wistar rats were studied under acute massive blood loss. Using the method of vital videomicroscope study of the influence of the influence of the blood volume reduction on the leukocyte-endothelium interaction is investigated. We studied vessels of the diameter under 30 mcm. It is shown that under progressing reduction of the system arterial pressure under 60 mm Hg, the number of leukocytes adhesion to venules' wall reached 20 +/- 3 on 100 mcm, but in terminal stage such acts are the greatest. It is supposed that as a result massive blood loss leukocytes turn out to be the direct reason of the deep pathological disturbances of microcirculation in the brain.     

Regeneration of the gastric mucosa under conditions of massive blood loss]

The autoradiographic method was used for a comparative study of regeneration of the gastric mucosa after wounding the rat with a preliminary loss of blood and without it. The H3-thymidin label index was determined in the portions of the mucosa of the wound edge and far from it. A histological analysis of healing the wounds failed to reveal any difference in terms of this process in rats with a loss of blood and without it. A momentary massive loss of blood did not influence the strain and intracellular regeneration processes in the healing wound of the stomach: the amount of cells synthesizing DNA at the edges of the gastrotonic wound proved to be the same in experiments both with a loss of blood and without it. The authors believe that it may serve as an indirect evidence of a somewhat exaggerated danger of surgery at the height of gastroduodenal bleeding.     

Effect of pyruvate on metabolic processes in erythrocytes after acute massive blood loss

It is shown in the in vitro experiments that addition into the incubation medium of 10 mumol pyruvate is accompanied by the inhibition of the lactate dehydrogenase activity. The level of 2.3-biphosphoglycerate, ATP, lactate and hemoglobin increases by 92%, 265%, 93% and 56%, respectively. The acute massive haemorrhage against a background of infusion of 0.065% solution of pyruvate does not evoke a decrease in the hemoglobin level, which is observed after infusion of the physiological solution. The value of hematocrit proved to be higher to some extent. The 2,3-biphosphoglycerate level and the activity of glucoso-6-phosphate dehydrogenase are not changed in comparison with the results of intact rats. The glutathione reductase activity rises by 38%. The lactate level diminishes by 34%. Pyruvate is established to exert a therapeutic effect in acute massive haemorrhage. The survival rate of rats after infusion of pyruvate increases by 65%.     

Faecal blood loss in response to exercise.

Recently qualitative tests have indicated that gastrointestinal bleeding during exercise may be an important contributory factor in sports anaemia. In six healthy men who walked 37 km on four consecutive days faecal haemoglobin content remained normal (reference range 0.10-2.53 mg/g faeces) with no significant differences between values. In 28 marathon runners who refrained from taking drugs or food containing blood the median faecal haemoglobin content increased by 0.42 mg/g faeces (95% confidence interval 0.12 to 0.83 mg/g) from 1.06 (0.86 to 1.31) mg/g before the race. In 13 runners who had taken drugs before the race the corresponding increase in the median faecal haemoglobin content was 0.87 (-0.03 to 2.20) mg/g from the value before the race of 0.93 (0.46 to 1.55) mg/g. Prolonged walking had no effect on gastrointestinal blood loss. Intense endurance exercise in the form of marathon running induced a significant but clinically unimportant increase. This may be exaggerated by the ingestion of drugs and assume importance in causing iron deficiency and sports anaemia. The use of drugs, particularly analgesics, by marathon runners should be actively discouraged.     

Ultrastructural and functional changes in the myocardium and coronary vessels after massive blood loss

The ultrastructure of cardiomyocytes and circulatory bed has been compared to transmembrane cAMP-dependent Ca2+ transport in experiments on the hearts of 14 dogs immediately after massive blood loss. The results an hour after non-compensatory hemorrhage have shown extra- and intracellular myocardial edema, central destruction of sarcomers, steep increase in the volume of agranular sarcomplasmic reticulum and T-system, different degree of damage of other organoids, and also disturbances in the ultrastructure of venous capillary and postcapillary section. The biochemical techniques used have shown a decrease in Ca2+ transporting ability of sarcolemma due to its AMP-dependent regulation of cardiomyocytes. Excessive Ca2+ storage in cytosole promoted the appearance of "constriction bands" in myofibrils.     

Defining plant functional groups to guide rare plant management

To effectively manage plant populations for conservation, there is a need to provide reliable information on the conditions required for maintaining viable populations. This is particularly true for the management of populations of rare plant taxa. Western Australia contains over 45% of Australia’s gazetted rare or threatened flora, 80% of which are found within the highly fragmented southwest region. Resources do not exist to undertake comprehensive studies on the population dynamics and demographics for every rare plant of this diverse region. Here, we describe a method of classifying rare plant taxa into functional groups as a basis for guiding rare flora conservation and management. Data on four floral and two life-history traits were collected for each of the 351 declared rare flora taxa of Western Australia. A hierarchical, agglomerative clustering method was applied to the resulting taxa by traits matrix to extract emergent groupings of plant taxa. The resulting polythetic groups were analysed to determine the variation in traits, including response to disturbance and recorded flower visitors, and how these may affect population persistence in a fragmented landscape. Multivariate methods were used to define emergent groups based on a combination of floral structure and life-history traits of the declared rare flora of Western Australia. Seven emergent functional groups were identified and were largely differentiated by flower shape and life form. These seven functional groupings varied significantly in their response to disturbance. By deriving these functional groups, we plan to develop models for each group on how rates of pollination, seed production and seed fitness are affected by population size and landscape context. The rationale would be to use these profiles to determine whether there are thresholds in population size or position in the landscape at which reproductive rates severely decline. General management guidelines could then be developed for each functional group. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Nomenclature Paczkowska and Chapman (2000).     

Noise-induced hearing loss and blood pressure.

From a group of industrial workers who had a noise-induced hearing loss of at least 30 dB at 4000 Hz 62 were randomly selected after stratification. Controls matched for age and duration of employment were also selected. Resting blood pressures were measured and audiometry was repeated. The findings are presented by age group and for the two groups as a whole. No relation between systolic or diastolic blood pressure and hearing loss was found, and equal proportions of each group had blood pressures exceeding 140/90 mm Hg. Persons with greater hearing loss (more than 60 dB at 4000 Hz) did not have significantly higher blood pressures than their matched controls.     

Parabrachial nucleus modulates cardiovascular responses to blood loss

The goal of this study was to determine the role of the pontine lateral parabrachial nucleus (LPBN) in the compensatory responses to blood loss. Conscious unrestrained rats with complete, partial, or sham bilateral ibotenic acid lesions of the LPBN were subjected to a hypotensive 16-ml/kg blood withdrawal via arterial catheter. Complete lesions (LPBNx) encompassed the entire LPBN and extended into the ventrolateral parabrachial region to encroach on the Kolliker-Fuse nucleus. Partial lesions were restricted to the body of the LPBN and spared the outer rim of the external lateral subnucleus of the LPBN. In all three groups, serum corticosterone concentration and plasma renin activity increased four- to fivefold after hemorrhage (P < 0.01), and immunocytochemistry demonstrated numerous Fos-positive neurons in the hypothalamic supraoptic nucleus. However, the cardiovascular responses to hypotensive blood loss differed for complete and partial lesions. Blood pressure failed to recover in LPBNx rats and was significantly lower in LPBNx (66 +/- 4 mmHg) than in rats with partial or sham lesions (98 +/- 4 and 85 +/- 5 mmHg, respectively) at 40 min posthemorrhage. In contrast, rats with partial lesions had a significant attenuation of the posthemorrhage bradycardia. This implies that a population of neurons within the body of the LPBN is essential for full expression of the bradycardia that accompanies hemorrhagic hypotension, whereas the ventrolateral parabrachial region is essential for normal restoration of arterial pressure after hypotensive hemorrhage.     

Effect of epinephrine on blood loss during liposuction.

Noncaseating granulomas present as a delayed foreign-body reaction to retained pencil-core fragments. The clinical appearance of the lesion can closely resemble melanoma. Surgeons who use pencils as surgical marking implements should be aware that there is a potential risk of developing late pencil-core granulomas. This risk can be reduced by carefully removing any pieces of pencil lead from the wound.