Canoeists' disorientation following cold immersion

As an initial step to a broader study of the disorientating effects of cold water immersions on top class competitive canoeists a survey was made of the incidence of hazardous immersions amongst a majority sample of the better canoeists in the country. Virtually the entire entry to one of the most important national competitive meets was canvassed. A total of 288 canoeists in the 1st and 2nd divisions were identified and asked to participate. Replies were received from 247 (86%).

All those responding had had extensive experience of canoeing in winter spate and were capable of fast and efficient first-time canoe rolls in cases of capsize. Particular interest was focussed on the 85 (34%) who had experienced at least one capsize in cold water during training or competition in mid-winter.

Respondents viewed the winter capsize seriously. Despite their familiarity with the conditions in which they trained all 85, recalling their capsize experiences, reported being concerned, most (79%) only modestly so, but a significant proportion (21%) confessed to feelings of extreme alarm.

A number of marked physical symptoms that regularly attend on a capsize were widely reported, the most usual of which was severe pain in the forehead (89%) and breathing and speaking difficulties when afloat (64%). Additionally 62% reported sensory problems including visual difficulties, dizziness and disorientation. Five canoeists admitted fainting.

Despite these hazards few preventive measures were taken and clothing with negligible thermal insulation properties was commonly worn. It is concluded that transient cold immersions can be disturbing, and can disorientate the canoeist, but that although conscious of this and to his own potentially high cost, he takes little notice of it in his desire to compete successfully.

Gelfoam paste in experimental laminectomy and cranial trephination: hemostasis and bone healing

The hemostatic properties and effect on osteogenesis of gelatin foam paste and bone wax were compared on surgical bone lesions in experimental animals. Thirty rabbits each received four trephine craniotomies and four lumbar laminectomies. Alternate bone incisions in each animal were treated with either gelatin foam paste or bone wax. Blood loss was measured by absorbing the blood into dry surgical cottonoids weighed before and after use. Bone healing sites of three rabbits were examined histologically to assess the effect of each agent on osteogenesis. The trephination sites of eight rabbits were subjected to fracture force testing at 6 weeks postoperatively to compare the effect ot the two agents on bone healing. No significant difference was found between gelatin foam paste and bone wax in either effectiveness of hemostasis or effect on osteogenesis.

Biochemical genetics of trehalose metabolism in Saccharomyces cerevisiae

Different strains of Saccharomyces cerevisiae exhibit alternative patterns of trehalose accumulation during growth on a glucose medium. The active pattern is designated as TAC(+) phenotype and the alternative, low-activity pattern as tac(-) phenotype. The tac(-) phenotype is expressed only during growth, since tac(-) strains actively accumulate trehalose during incubation in a glucose medium lacking a nitrogen source. The tac(-) phenotype appears to be determined by a single, recessive gene tac1. The quantitative expression of the dominant, alternative allele TAC1 is subject to wide variation. A highly active pattern of trehalose accumulation requires TAC1 and an amplification factor, TAM, which consists of one or more dominant gene(s). TAM does not appear to alter significantly the expression of tac1. Highly amplified TAC(+) strains may contain a labile factor not present in a TAC(+) strain which accumulates intermediate levels of trehalose.

Role of calcium and albumin in the autoregulation of renal perfusate flow

1. We investigated the role of calcium and albumin on the perfusate flow in isolated perfused rat kidneys. The initial perfusion medium was Krebs-Henseleit bicarbonate solution with 1.82 mm-calcium without albumin. Perfusate flow autoregulation occurred above 100 mmHg.2. Raising albumin concentration to 20 and 60 g/l. abolished autoregulation and increased perfusate flow.3. Keeping ionized calcium at 1.82 mm restored autoregulation in medium containing 20 and 60 g albumin/l. However, in 60 g albumin/l. autoregulation occurred at a significantly higher flow.4. 1.82 mm-ionized calcium appears to be a critical level for autoregulation of flow in these experiments, for autoregulation was not obtained in 60 g albumin/l. medium containing 1.80 mm-ionized calcium. On the other hand, autoregulation occurred in medium containing 1.83 mm-ionized calcium, but at a lower perfusate flow.5. Raising albumin concentration to 120 g/l. increased perfusate flow from 14.6+/-0.8 to 20.8+/-0.7 ml./min.g (n = 5, P < 0.01) in the presence of 1.82 mm-total calcium, and from 11.6+/-1.0 to 15.8+/-0.7 ml./min.g (n = 5, P < 0.01) in 1.82 mm-ionized calcium. The effect of raising albumin concentration was reversible.6. Removing the capsule from the kidneys abolished the increased flow in response to raising albumin concentration.7. We conclude that (a) the mechanism for the autoregulation of renal perfusate flow in isolated perfused kidneys is critically dependent on an extremely narrow range of ionized calcium concentration in the perfusion medium, below this range, autoregulation is not achieved; above it, however, autoregulation is achieved, but during intense vasoconstriction; (b) raising albumin concentration in the perfusion medium increases perfusate flow and abolishes autoregulation by lowering extracellular ionized calcium and by raising intrarenal tissue pressure.

Failure to induce reactive hypoglycaemia by drinking a starch-based alcohol beverage (sorghum beer)

Alcohol is a well-recognised cause of fasting hypoglycaemia but may also provoked reactive hypoglycaemia when drunk together with a carbohydratee mixer. In this study the ability of sorghum beer (an 'in-built' alcohol-starch beverage widely enjoyed in Southern Africa) to induce reactive hypoglycaemia was compared with "gin and tonic' in eight non-obese health African men. After an overnight fast, each subject drank, in random sequence on their different occasions, 2 litres of sorghum beer (carbohydrat content approximately 5% and alcohol concentration 2.24 g/dl-2.8% v/v), the same volume of a control solution providing a similar carbohydrate load, or a gin and standard tonic water mixture. No evidence of reactive hypoglycaemia was apparent during the 5 hours after the beginning of the sorghum beer tolerance tests, despite a mean peak blood alcohol level reaching 80 mg/dl. both the peak and total plasma insulin responses were significantly reduced (p less than or equal to 0.05) when compared to the brisk responses elicited by the carbohydrate solution alone and the gin and tonic drinks, with consequent hypoglycaemia. These data suggest that African home-brews are not potent causes of reactive hypoglycaemia, although they may be implicated in the development of ethanol-induced hypoglycaemia in the fasting state.

Comparison of cefotaxime and moxalactam pharmacokinetics and tissue levels

The pharmacokinetics of cefotaxime and moxalactam were compared in six healthy male volunteers aftr the administration of 1-g doses intravenously. Penetration of the compounds into tissue fluid was studied in cantharides-induced blisters. Both serum and tissue fluid levels of moxalactam were higher than those of cefotaxime. The elimination half-life of cefotaxime was 1.2 h, and that of moxalactam was 2.85 h. On the average, 50.5% of cefotaxime and 87.5% of moxalactam were recovered in the urine in 24 h.

Methylmethacrylate onlay implants in the treatment of forehead deformities secondary to craniosynostosis

Craniosynostosis (Cruzon's, Pfeiffer's and Apert's Syndrome, etc.) can cause forehead deformities that frequently need reconstruction. In general, osteotomies and/or bone grafting are the preferred methods for obtaining proper orbital protection from above and a good aesthetic appearance. In certain cases however, osteotomies and/or bone grafting are not possible or a patient may refuse to have such an extensive procedure. Preformed methylmethacrylate prostheses have in such cases been implanted in patients with significant skull deformities with only minimal morbidity. The ease of this technique coupled with the shortened operative time, minimal hospitalization, and few, minor complications offer the reconstructive surgeon another and relatively simple method for treatment of extensive forehead and supraorbital deformities.

The influence of protein binding upon tissue fluid levels of six beta-lactam antibiotics

The effect of protein binding upon the penetration of six-beta-lactam (three penicillins and three cephalosporins) antibiotics into tissue fluid was studied in humans. A cantharides blister technique was used. It was found that there was a linear relationship between the percentage of protein binding and the penetration into the blister fluid of the antibiotic as measured by the area under the curve of the protein-free fraction. This finding is further evidence that protein binding may have important influence upon the likely efficacy of an antimicrobial agent.

Comparison of mutagenesis and malignant transformation by dihydrodiols from benz[a]anthracene and 7,12-dimethylbenz[a]anthracene

Five dihydrodiols derived from benz[a]anthracene (BA) and 4 dihydrodiols derived from 7,12-dimethylbenz[a]anthracene (DMBA) have been tested, together with the parent hydrocarbons, for their abilities to induce mutations to 8-azaguanine resistance in V79 (Chinese hamster cells and malignant transformation in M2 mouse fibroblasts. The syn- and anti-isomers of benz[a]anthracene 8,9-diol 10,11-oxide were also tested for biological activity in these two systems. The non-K-region 1,2- and 3,4-dihydrodiols of BA induced mutations but the non-K-region 8,9-dihydrodiol and the K-region 5,6-dihydrodiol were inactive as mutagens; none of these BA diols transformed M2 mouse fibroblasts. The 3,4- and the 8,9-dihydrodiols derived from 7,12-dimethylbenz[a]anthracene induced mutations in V79 cells and malignant transformation in M2 mouse fibroblasts and both were more active than the hydrocarbon itself. The K-region 5,6-dihydrodiol and the non-K-region 10,11-dihydrodiol of DMBA were inactive in both test systems. The results are not inconsistent with other data suggesting that the metabolic activation of both BA and DMBA occurs through conversion of the respective 3,4-dihydrodiols into the related vicinal diol-epoxides, although other dihydrodiols may also be involved in vivo. Both the BA diol-epoxides tested were mutagenic, but although the anti-isomer transformed M2 fibroblasts, the syn-isomer was inactive.

Rheumatoid polyarthritis after rubella

A 21-year-old woman developed persistent polyarthritis indistinguishable from rheumatoid arthritis after rubella. The arthritis persisted for approximately 30 months and was associated with high levels of antibody to rubella virus and with rheumatoid factor. The antibody titres declined pari passu with clinical improvement which progressed to complete resolution. Fractionation of serial serum specimens showed a substantial and persistent IgM antibody response to rubella virus. Rubella antigen was not demonstrated in the synovial exudate.

Incontinentia pigmenti in a Black baby: a case report

This is a case report of a Black baby girl who presented at the age of 7 days with incontinentia pigmenti. While the classic 3 phases of inflammation, hyperkeratosis, and irregular pigmentation are the rule, this patient demonstrates an accepted variation, presenting with irregular pigmentation without having gone through the other phases. Ninety-five per cent of the described cases have been in females. A negative family history, as in this case, is not unusual.

The T gamma chain of human fetal hemoglobin at birth and in several abnormal hematologic conditions

The T gamma chain of human fetal hemoglobin has a threonyl in stead of an isoleucyl residue in position 75. When the cord bloods from infants from varied ethnic backgrouds and geographic areas were tested for the presence of the T gamma chain, it was present in 28 or 98 samples. In some groups as many as 40% had the T gamma chain whereas none was detected in other. When the T gamma chain was present, its quantity was about 20% of the total gamma chains, but one case had 35%. Among beta-thalassemia homozygotes of the Mediterranean region, 70% and the T gamma chain in the amount of 20-50% of the total gamma chains, but seven Black beta-thalassemia homozygotes were negative for the T gamma chain. The fetal hemoglobin of 16 adult patients with sickle cell anemia had no T gamma chains, but 2 of 9 newborn children with sickle cell anemia had the T gamma chain. The frequency of the T gamma gene (16), the relationship of the T gamma gene to the G gamma and A gamma genes, and the significance of the T gamma gene are discussed.

Malignant transformation and mutagenesis in mammalian cells induced by vicinal diol-epoxides derived from benzo(a)pyrene

Benzo[a] pyrene and the syn- and anti-isomers of the 7,8-diol 9,10-oxide and of the 9,10-diol 7,8-oxide derived from this hydrocarbon have been tested for their abilities to induce malignant transformation in M2 mouse fibroblasts and mutagenesis in V79 Chinese hamster cells. The anti-isomer of the 7,8-diol 9,10-oxide induced more mutations and transformation than did the other three vicinal diol-epoxides. The two 9,10-diol 7,8-oxides were moderately mutagenic but did not induce any transformation. In contrast, benzo[a]-pyrene induced transformation in M2 fibroblasts but was not mutagenic in the V79 cells.

Ultrasonic evaluation of salivary glands

Diagnostic ultrasound was used to study 40 patients undergoing excision of a major salivary gland for various disease entities. Findings were as follows: Malignant lesions showed low reflectivity and attenuation with poorly outlined or diffuse borders. Inflammation demonstrated high reflectivity and attentuation with diffuse borders. Echographic patterns from mixed tumors showed either high or medium to low reflectivity; all demonstrated low to medium attenuation and were well outlined. It appears that various diseases of the major salivary glands have different echographic patterns. An attempt to correlate the echographic patterns with the histology of the disease process was made.

The metabolic activation of 7-methylbenz(a)anthracene: the induction of malignant transformation and mutation in mammalian cells by non-K-region dihydrodiols

Four different dihydrodiols derived from 7-methylbenz(a)anthracene have been tested, together with the parent hydrocarbon, for their ability to induce the in vitro malignant transformation of mouse M2 fibroblasts and mutations in V79 Chinese hamster cells. In the transformation tests withe the non-K-region dihydrodiols, the 3,4-diol was the most active dihydrodiol tested and the 8,9-diol was also more active than 7-methylbenz(a)anthracene itself; the 1,2-diol showed only slight activity. The K-region dihydrodiol, the 5,6-diol, which cannot be directly metabolized to a vicinal diol-epoxide, was inactive. These differences in biological activity were similar to those apparent in the results from the mutagenicity tests. The data support the general hypothesis that non-I-region dihydrodiols, which can be metabolized to vicinal diol-epoxides, are important in the metabolic activation of the carcinogenic polycyclic hydrocarbons and, when taken together with other results, indicate that 3,4-dihydro-3,4-dihydroxy-7-methylbenz(a)anthracene is most probably involved in the metabolic activation of 7-methylbenz(a)anthracene presumably following conversion into the related diol-epoxide, 3,4-dihydro-3,4-dihydroxy-7-methylbenz(a)anthracene 1,2,-oxide.

Mucosal recovery in treated childhood celiac disease (gluten-sensitive enteropathy)

Follow-up studies on 36 children, in whom celiac disease (gluten-sensitive enteropathy) was established by gluten challenge, were carried out after management on gluten-free diets for a mean of six years. Evaluations included measurement of height and weight, which for the group approximated normal distributions, and histologic examination of the duodenal or jejunal mucosa. Mucosal morphology was regarded as normal in 16, and there were minimal changes in 20. Epithelial cell height was within the normal range in all the children. Interepithelial lymphocytes were within normal range in the majority and lymphoid cells in the lamina propria were not different from those in control subjects. Mucosal lactase was significantly lower in patients than in control subjects in the duodenum and the jejunum, whereas sucrase and alkaline phosphatase values were significantly lower in the jejunum but not in the duodenum. Low content of mucosal lactase and increased numbers of interepithelial lymphocytes may be sensitive indicators of persisting ingestion of gluten in mucosa that is otherwise normal or approximately so in appearance.

Progressive myelopathy due to radiation

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