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Biomedical subjects

J Hattingh

Publications and source records attributed to J Hattingh.

At least 37 records · Page 2Linked to original sources
PubMed1988

Comparative quantitation of the physiological response to acute stress in impala and roan antelope.

1. The concentrations of 8 variables in the blood of impala and roan antelope exposed to acute stress were investigated. 2. An objective measure of the acute stress response, based on the % maximal change of the 8 variables, is suggested. 3. The method takes into account the species specificity of the stress response and is based on changes in the concentration of variables which reflect the (general) hormonal and (neuro-) endocrine balance of an animal at a given time. 4. The species-specific experimental response to stress (SSERTS), thus obtained, is time and procedure dependent.

Animals↗
PubMed1988

Remote controlled sampling of cattle and buffalo blood.

1. Blood samples were obtained from cattle and buffaloes over extended periods of time by remote controlled methods at 4-hourly intervals. 2. Initial handling of the animals and deliberate exposure to stress at the end of the experimental times resulted in increased plasma concentrations of a number of variables. 3. Between initial handling and applied stress, the concentration of all variables investigated showed little change and no evidence of rhythms. 4. The results obtained reflect true plasma composition of free ranging cattle and buffaloes at rest.

Animals↗
PubMed1988

Effects of chemical immobilisation on the blood composition of impala (Aepyceros melampus (Lichtenstein).

The effects of chemical immobilisation on impala (Aepyceros melampus) were investigated. The results indicate that etorphine HCl or Carfentanil should not be used in isolation but that xylazine should be included in the immobilisation "cocktail". The highest dose possible, commensurate with safety, should be used in order to minimise time and distance to recumbency. Body temperature should be monitored and if cooling measures are not effective the animal should be aroused. Either diprenorphine HCl alone or in combination with yohimbine and 4-aminopyridine should be used as antidote/s.

Animals↗
PubMed1987

Salivary immunoglobulins in healthy white and black adults compared with oesophageal cancer patients.

Saliva is a readily accessible mucosal secretion and salivary antibodies reflect the repertoire of gut-associated antigens; it therefore appears to be ideal for the study of gastro-intestinal disease. A study of salivary immunoglobulins in healthy white and black adults and patients with oesophageal cancer showed that salivary immunoglobulin A levels were higher (but not significantly) in whites than blacks. The levels, however, were similar in healthy blacks and oesophageal cancer patients. There is a wide variation in normal levels of salivary immunoglobulins. Also, immunoglobulins are readily influenced by physiological factors and so at present are unreliable indices of gastro-intestinal disease.

Adult↗
PubMed1987

Hematologic, iron-related, and acute-phase protein responses to sustained strenuous exercise.

This study was undertaken to gain insight into the mechanisms responsible for the hypoferremia occurring after severe exercise. To this end, 18 athletes who were competing in a 160-km triathlon involving canoeing, cycling, and running were evaluated before the race, immediately after the finish, and thereafter at 30 min, 24 h, and 48 h. The evaluation included plasma iron, total iron-binding capacity, lactoferrin, ferritin, haptoglobin, cortisol, various enzymes, and white cell count. The cortisol, white cell count, and lactoferrin were significantly increased immediately after the race, while the plasma iron and transferrin saturation were significantly decreased. There was a 40% but nonsignificant rise in the plasma ferritin at the completion of the race, while the C-reactive protein was raised by nearly 300% at 24 h. In contrast, haptoglobin declined significantly by 24 h but was normal again 24 h later. Quantitative considerations suggested that the lactoferrin was not responsible for removing transferrin iron from circulation and hence causing the hypoferremia. Instead, it seemed more likely that the iron-related changes were occurring as part of an acute phase response initiated by muscle injury.

Acute-Phase Proteins↗
PubMed1986

The response of runners to arduous triathlon competition.

As very few of the competitors in a triathlon are truly specialist in more than one of the three disciplines, high levels of physical (and mental) stress may result during the course of the event. We investigated some of the physiological responses occurring in runners participating in an "Iron Man" triathlon consisting of canoeing (20 km), cycling (90 km) and running (42 km), in that sequence. Twenty-one male entrants volunteered as subjects for the study. Prior to the competition, maximal oxygen consumption (VO2max) was determined. Basal venous blood samples were collected on the day prior to the competition and post-exercise venous blood samples were collected within 5 minutes of completion of the race. Serum iron was significantly reduced from a mean basal value of 20.6 mumol X l-1 to a mean value of 8.4 mumol X l-1 after the race. Cortisol levels showed a 3 fold increase after the race. Gross VO2max (l X min-1) and mass standardised VO2max (ml X min-1 X kg-1) were both negatively correlated to cortisol levels after the race (p less than 0.05). Total performance time was not related to gross VO2max (l X min-1) but was well correlated to mass corrected VO2max (ml X min-1 X kg-1). The marked fall in serum iron may have been related to heavy sweating or prelatent iron deficiency. Chronic iron deficiency (without frank anaemia) can impair physical performance, although we were unable to show any significant correlation between serum iron level after the race and time taken to complete the event.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

The effect of hydrocortisone and albumin on the synthesis and secretion of soluble proteins by isolated hepatocytes.

Monolayer cultures of hepatocytes were prepared. Supplementation of the incubation medium with bovine serum albumin increasing from 150 mg% to 6% resulted in an increase in retained and total newly synthesised proteins. No clear effects on secretion of soluble proteins were observed. Hydrocortisone supplementation of the medium at 13.75 and 27.50 nmol/l resulted in both enhanced synthesis and secretion of soluble proteins, an effect found not to be a function of concentration. Serum inhibited the effect. Hydrocortisone supplementation resulted in enhanced [3H]leucine uptake by the cells, inhibited in the presence of anti-rat albumin serum. Hydrocortisone supplementation had no effect on the inhibition of synthesis and secretion that resulted from supplementation of the medium with anti-rat albumin serum.

Animals↗
PubMed1986

Arterial blood gas composition, consciousness and death in rabbits.

Conscious rabbits were exposed to environments with low oxygen and/or high carbon dioxide. The electroencephalogram and arterial blood pressure were recorded. Arterial blood samples were taken sequentially. Rabbits became 'unconscious' at an arterial blood PO2 of 25 +/- 1 mm Hg and PCO2 of 99 +/- 27 mm Hg, when simultaneously the environmental oxygen was decreased and carbon dioxide increased. Brain death occurred at a PO2 of 23 +/- 1 mm Hg and PCO2 of 113 +/- 32 mm Hg. Cerebral perfusion was still adequate. In rabbits, the margin between 'unconsciousness' and 'death' is narrow so far as PO2 is concerned. If these results apply generally, animals culled with muscle relaxants may perceive stress involved until shortly before death.

Animals↗
PubMed1985

Effects of anti-albumin sera on the synthesis and secretion of soluble proteins by monolayers of hepatocytes.

Hepatocytes were isolated from male Sprague-Dawley rats and monolayer cultures prepared. The effects of supplementation of the incubation medium with homologous and heterologous antisera directed against albumin on the synthesis and secretion of soluble proteins were ascertained. Supplementation of the medium with antisera generally resulted in a time related decrease in the synthesis and secretion of soluble proteins. The observed inhibition did not appear to be due to deficient amino acid uptake and the cell membranes remained intact in the presence of antisera. The results are discussed in relation to findings obtained with malignant cells.

Animals↗
PubMed1985

Plasma constituents in Nguni cows over forty-eight hours.

Plasma constituents were investigated at ninety minute intervals over a forty-eight hour period on four unrestrained Nguni cows (in small cubicles) in order to study the presence or absence of rhythms. No circadian, ultradian or diurnal rhythm was found for any of the parameters investigated. Basal values over a forty-eight hour period were obtained for certain plasma constituents. These values are of use for studies relating to the effects of stress in cattle.

Adrenocorticotropic Hormone↗
PubMed1984

Blood composition in culled elephants and buffaloes.

Blood composition of succinyldicholine culled elephants and buffaloes was compared with that of undisturbed animals shot in the brain. The results show statistically significant differences in a number of variables including plasma ACTH and cortisol concentrations. The observed changes are attributed to stress induced by a combination of herding and darting with succinyldicholine and asphyxia. Extrapolation from blood oxygen tensions suggests that this stress may be perceived for an undetermined period which is probably longer in elephants than buffaloes.

Acid-Base Equilibrium↗
PubMed1983

Concentration and composition of plasma proteins in wild mammals.

Total protein concentrations from a variety of wild mammalian species were measured by the Lowry and Biuret techniques and compared with results obtained or derived by refractometry. Values obtained with the Lowry method were the highest and certain derived refractometry results, the lowest. It is suggested that the Biuret method provides the most acceptable values but that care should be exercised in using the correct standard. The percentage composition of plasma from 22 species of wild mammals is also presented and the observations discussed with relation to methodology and A/G ratio.

Animal Population Groups↗
PubMed1983

The composition of plasma and interstitial fluid of sheep with the 'wet carcass' syndrome.

Carcasses of sheep from various areas in South Africa and South West Africa (Namibia) show a wet glistening appearance immediately after slaughter. The subcutaneous interstitial fluid of these sheep has a significantly lower protein concentration and colloid osmotic pressure and a significantly higher albumin/globulin ratio than that of normal sheep. These results imply the presence of an oedema and an increased capillary permeability to protein. They suggest that histamine, or an histamine-like substance, mediates the changes.

Abattoirs↗
PubMed1983

The composition of plasma and interstitial fluid of goats with swelling disease.

Angora goats may develop a characteristic ventral oedema of the subcutaneous tissue which is not unlike the 'wet-carcass syndrome' of sheep. The plasma of oedematous goats shows a lower total protein concentration, a lower colloid osmotic pressure and a lower albumin: globulin ratio than that of normal goats. Similarly, interstitial fluid of oedematous goats has a lower protein concentration, osmolality and colloid osmotic pressure than the fluid from normal but a similar albumin:globulin ratio. These results suggest that, unlike the 'wet-carcass syndrome' of sheep, the most likely explanation for the oedema is hypoproteinaemia which leads to filtration of fluid and an increased capillary permeability.

Animals↗