Tetrazolium medium as an aid in the routine diagnosis in Candida.

The tetrazolium medium described is easily prepared and serves as a rapid, relatively accurate and simple means of differentiating Candida species, particularly C. albicans, from other yeasts. Culture on this medium does not replace other techniques used for yeast identification. No one test alone will suffice and final identification must rest on an overall pattern of characteristics. In the screening of 1,822 yeast isolates in this laboratory, culture on this medium has proved a valuable adjunct to other recognized techniques, and is now in regular use.

Kidney structure and function of desert kangaroos.

The structure and function of the kidneys of two species of desert kangaroos, the red kangaroo (Megaleia rufa) and the euro (Macropus robustus), were examined. Both kangaroos had glomerular filtration rates (GFR), renal plasma flows, and urine flow rates, when hydrated and dehydrated, which were lower than those of similarly sized eutherian mammals. The differences observed between the two species of marsupials were both structural and functional. The GFR of the red kangaroo was higher than that of the euro, under hydrated and dehydrated conditions, and this was correlated with the occurrence of larger and more numerous glomeruli, particularly juxtamedullary glomeruli, in the red kangaroo. Although the kidney of the euro had a greater relative medullary thickness than that of the red kangaroo, the latter had better urine-concentrating abilities. As opposed to this the euros reabsorbed significantly more urea from the filtrate when dehydrated (89.0%) than did the red kangaroos (69.2%). This ability of the euro to resorb more urea may be related to their tendency to overgraze their restricted home ranges during drought.

Comparative metabolism of tritiated water by macropodid marsupials.

The total body-water content (TBW) and rate of water turnover were measured usingtritiated water in five species of macropodod marsupials (kangaroos), which ranged in weight from 1 to 50 kg. Animals fitted with rumen cannulas were used to estimate the time required for tritiated water to equilibrate within the body of large kangaroos. In hydrated kangaroos this was 6 h, during the time 2.7% of the injected tritiated waterwas lost from the body. During dehydration, the equilibrium time was extended to 10h. Values up to 78% of body weight were found for TBW in the larger species of kangaroo, and these values were similiar to those found for other ruminantlike mammals, particularly those with a low body-fat content. The smaller macropodids had a TBW (about 60% of body weight) similiar to that of most laboratory mammals. The rates of waterturnover of the macropodids were related to body weights by the expression 1/day = 0.09kg-0.80. Macropodid marsupials have a daily water usage shich is about two-thirds ofthat found for eitherians and this may be related to the lower metabolic rate of marsupials.

Effects of dehydration on body-water distribution in desert kangaroos.

The effect of dehydration on the distribution of water in the bodies of two species of desert kangaroos, the red kangaroo Megaleia rufa and the euro Macropus robustus, has been examined. The volumes of various body-fluid compartments were determined in normally hydrated animals and then after the kangaroos had been dehydrated until body weight declined to 80% of the initial weight. The fluid compartments examined were total body water, plasma volume, intracellular volume (cellular and gut water), and extracellular volume. Both species were camel-like in their response to dehydration in that plasma volume was maintained in both species, falling by only 8.3% in red kangaroos and 7.4% in euros. The pattern of water loss from other compartments differed between species, particularly gut water loss. This compartment, which includes the large rumenlike fore stomach, contributed 56% of the total water loss of red kangaroos but only 22% of the loss from euros. The ecological implications of the preferential maintenance of gut water by the sedentary, cave-dwelling euros have been discussed.

Genital yeast infections.

Genital yeast infection was studied in 533 women seen in a department of venereology. Yeasts were recovered in culture from 138 patients (26% of the total). Candida albicans accounted for 112 (81%) of the isolates and Torulopsis glabrata for 22 (16%); other yeasts were uncommon. There was no evidence that the presence of yeasts was related to age. 32% of the women who were taking an oral contraceptive harboured yeasts, compared with 18% of those who were not.The symptoms and signs of the women with yeast infections were compared with those with vaginal trichomoniasis and those with no evidence of genital infection. It seems that a clinical diagnosis of vaginal mycosis cannot be made with accuracy and that positive identification of yeasts is necessary; for this, cultural methods are the most satisfactory.

Prediction of cardiac events after uncomplicated myocardial infarction: a prospective study comparing predischarge exercise thallium-201 scintigraphy and coronary angiography.

The ability of predischarge quantitative exercise thallium-201 (201T1) scintigraphy to predict future cardiac events was evaluated prospectively in 140 consecutive patients with uncomplicated acute myocardial infarction; the results were compared with those of submaximal exercise treadmill testing and coronary angiography. High risk was assigned if scintigraphy detected 201T1 defects in more than one discrete vascular region, redistribution, or increased lung uptake, if exercise testing caused ST segment depression greater than or equal to 1 mm or angina or if angiography revealed multivessel disease. Low risk was designated if scintigraphy detected a single-region defect, no redistribution, or no increase in lung uptake, if exercise testing caused no ST segment depression or angina, or if angiography revealed single-vessel disease or no disease. By 15 +/- 12 months, 50 patients had experienced a cardiac event; seven died (five suddenly), nine suffered recurrent myocardial infarction, and 34 developed severe class III or IV angina pectoris. Compared with that of patients at low risk, the cumulative probability of a cardiac event was greater in high-risk patients identified by scintigraphy (p less than .001), exercise testing (p = .011), or angiography (p = .007). Scintigraphy predicted low-risk status better than exercise testing (p = .01) or angiography (p = .05). Each predicted mortality with equal accuracy. However, scintigraphy was more sensitive in detecting patients who experienced reinfarction or who developed class III or IV angina. When all 50 patients with events were combined, scintigraphy identified 47 high-risk patients (94%), whereas exercise-induced ST segment depression or angina detected only 28 (56%) (p less than .001). The presence of multivessel disease as assessed by angiography identified nine more patients with events than exercise testing (p = .06). However, the overall sensitivity of angiography was lower than that of scintigraphy (71% vs 94%; p less than .01) because three patients who experienced reinfarction and 10 who developed class III or IV angina had single-vessel disease. Importantly, 12 (92%) of these 13 patients with single-vessel disease who had an event exhibited redistribution on scintigraphy. These results indicate that (1) submaximal exercise 201T1 scintigraphy can distinguish high- and low-risk groups after uncomplicated acute myocardial infarction before hospital discharge; (2) 201T1 defects in more than one discrete vascular region, presence of delayed redistribution, or increased lung thallium uptake are more sensitive predictors of subsequent cardiac events than ST segment depression, angina, or extent of angiographic disease; and (3) low-risk patients are best identified by a single-region 201T1 defect without redistribution and no increased lung uptake.