Fibrinolytic response to standardized venous occlusion in different age groups

The purpose of this study was to find out the range and distribution of fibrinolytic response to standardized venous occlusion in healthy volunteers and to determine whether there were any differences according to age and sex. In 118 healthy volunteers (55 males, 63 females) of various age groups, the total fibrinolytic activity in euglobulin fractions was measured by a well controlled fibrin plate method before and after venous occlusion of 5 minutes at 100 mmHg. The difference between our method and previous methods is that we occluded for a relatively shorter duration than that of previous studies (15-20 minutes) at constant pressure (100 mmHg), instead of midway between systolic and diastolic pressure. This method was reliable and reproducible as a tool to qualify and assess the fibrinolytic activity capacity of individuals. The results showed that there was no difference in basal fibrinolytic activity and the response to stimuli in various age groups (p greater than 0.25) and in male and female groups (0.1 less than p less than 0.375).

Determination of methylated amino acids in human serum by high-performance liquid chromatography

Employing high-performance liquid chromatography with isocratic elution using a two-column system (mu Bondapak C18 and mu Bondapak CN) and phenyl isothiocyanate as a fluorogenic reagent, NG-monomethylarginine (MMA). NG-dimethylarginines, and epsilon-N-trimethyllysine (TML) can be quatitatively separated from human serum samples. The recoveries of these amino acids were over 90%. It was observed that the serum concentrations of MMA, DMA and TML were significantly elevated in sera obtained from patients suffering from diabetes mellitus, hepatitis or hyperthyroidism, particularly the last condition.

Changes in thermal insulation during underwater exercise in Korean female wet-suit divers

The present work was undertaken to examine the effect of wet suits on the pattern of heat exchange during immersion in cold water. Four Korean women divers wearing wet suits were immersed to the neck in water of critical temperature (Tcw) while resting for 3 h or exercising (2-3 met on a bicycle ergometer) for 2 h. During immersion both rectal (Tre) and skin temperatures and O2 consumption (VO2) were measured, from which heat production (M = 4.83 VO2), skin heat loss (Hsk = 0.92 M +/- heat store change based on delta Tre), and thermal insulation were calculated. The average Tcw of the subjects with wet suits was 16.5 +/- 1.2 degrees C (SE), which was 12.3 degrees C lower than that of the same subjects with swim suits (28.8 +/- 0.4 degrees C). During the 3rd h of immersion, Tre and mean skin temperatures (Tsk) averaged 37.3 +/- 0.1 and 28.0 +/- 0.5 degrees C, and skin heat loss per unit surface area 42.3 +/- 2.66 kcal X m-2 X h. The calculated body insulation [Ibody = Tre - Tsk/Hsk] and the total shell insulation [Itotal = (Tre - TW)/Hsk] were 0.23 +/- 0.02 and 0.5 +/- 0.04 degrees C X kcal-1 X m2 X h, respectively. During immersion exercise, both Itotal and Ibody declined exponentially as the exercise intensity increased. Surprisingly, the insulation due to wet suit (Isuit = Itotal - Ibody) also decreased with exercise intensity, from 0.28 degrees C X kcal-1 X m2 X h at rest to 0.12 degrees C X kcal-1 X m2 X h at exercise levels of 2-3 met.(ABSTRACT TRUNCATED AT 250 WORDS)

A new HPLC analytical method for o-hydroxyhippuric acid in uremic serum

o-Hydroxyhippuric acid (HHA) is formed in liver during the process of detoxication of salicylic acid which arises from either salicylic-containing dietary vegetables or hydrolysis of aspirin. Recently, HHA has also been shown as one of the so-called 'uremic toxins'. By derivatization of HHA with o-phthaldialdehyde (OPA), the resulting fluorescent product can easily be measured with the limit of measurement somewhere below 3 pmol on high performance liquid chromatography. Using the method described, an approximately 85% recovery of added HHA in human sera was obtained. This analytical system is now being employed to determine the concentration of HHA in human sera of uremic patients. Determination of HHA content in human uremic patients is very important, since uremia is associated with defective binding of many acidic drugs to serum protein(s) and HHA replaces these drugs by tightly binding to these proteins. This could potentially affect the therapeutic effectiveness of various pharmacologic agents.

Studies on naturally occurring proteinous inhibitor for transmethylation reactions

An inhibitor for S-adenosyl-L-methionine (AdoMet)-dependent methyltransferases has been purified from rat liver particulate fraction to apparent homogeneity, as judged by high-performance liquid chromatography, two-dimensional paper electrophoresis and isoelectric focusing chromatography. This inhibitor molecule, which is composed of 27 amino acid residues with an additional fluorescent chromophore, is rich in glycine, contains no basic amino acid, and has an isoelectric point (pI) of 3.70. A single absorption peak was observed at 248 nm in acidic as well as in neutral media, while two peaks were detected in alkaline medium at 206 nm and 248 nm. The former peak was found to be quite labile. The fluorescent spectra with excitation peak at 285 nm and emission peak at 358 nm are greatly influenced by the pH, being the highest in alkaline medium. The purified inhibitor inhibits all the AdoMet-dependent methyltransferases examined.

Patterns of wet suit diving in Korean women breath-hold divers

Work shifts, diving pattern, diving lung volumes, and counterweights were studied in professional Korean women breath-hold divers wearing wet suits. One of the major differences, compared with their diving pattern only a few years ago when wearing cotton suits, is the prolongation of the diving shifts from 70 to 180 min in the summer and 10 to 120 min in the winter. In sustained diving the average dive and surface times in a 5-m dive are 32 and 46 s, and in a 10-m dives, 43 and 85 s, respectively. During a 3-h shift the total bottom time for harvesting is 37 min in 5-m dives and 17 min in 10-m dives. Rates of descent and ascent are 0.55 and 0.84 m/s. The wet suit divers adjust their counterweights to obtain a 12% positive buoyancy at the surface of sea water in contrast to the 8% positive buoyancy of cotton suit divers. The average lung volumes before and after a dive are 79% and 64% of their vital capacities, values similar to those of previous cotton suit divers.

Time course of deacclimatization to cold water immersion in Korean women divers

Seasonal basal metabolic rates (BMR), critical water temperature (Tcw), maximal body insulations (Imax), and finger blood flow during hand immersion in 6 degrees C water (Q finger) were measured periodically during the course of a 3-yr longitudinal study (1980-1982) of modern Korean diving women (ama), who have been wearing wet suits since 1977 to avoid cold stress during work. Methods and protocols were identical to previous studies of cotton-suited ama from 1961-1974. The BMR of modern ama did not undergo seasonal fluctuation (1980-1981) and was within the DuBois standard and comparable to nondivers year around Tcw of ama was still reduced by 2-3 degrees C in 1980 but increased progressively to equal that of nondivers in 1982, when compared at comparable subcutaneous fat thickness (SFT). Since modern ama and nondivers have 2.4 times thicker SFT (i.e., 4-13 mm) than in 1962 the absolute Tcw is significantly reduced. Q finger of ama was also significantly lower than controls in 1980 but in 1981-1982 was identical to controls. Imax of modern ama was identical to controls of comparable SFT in 1980-1982. The time course of cold deacclimatization thus was BMR, 3 yr; Imax, 3 yr; Q finger, 4 yr; and Tcw, 5 yr. This longitudinal study provides further evidence that acclimatization to cold did at one time exist in these diving women.

Energetics of wet-suit diving in Korean women breath-hold divers

Contemporary Korean women divers wear wet suits during diving work to avoid the cold water stress. The present study was undertaken to evaluate the effect of wearing wet suits on the daily thermal balance of divers and on the duration of diving work. Rectal (TR) and skin temperatures and O2 consumption (VO2) were measured in four divers before and during diving work in summer (22.5 degrees C water) and winter (10 degrees C water). Subjects wore either wet suits (protected) or cotton suits (unprotected) for comparison. TR decreased 0.4 degrees C in summer and 0.6 degrees C in winter after 2 h of diving work in protected divers, while it decreased to 35 degrees C in 60 min in summer and in 30 min in winter in unprotected divers. Mean skin temperature of protected divers decreased to 31 degrees C in summer and 28 degrees C in winter, while that of unprotected divers decreased to 24 degrees C in summer and 13 degrees C in winter. VO2 toward the end of the diving work period increased by 80 (summer) and 140% (winter) in protected divers and by 160 (summer) and 250% (winter) in unprotected divers. From these values total thermal cost of diving work was estimated to be 260 and 370 kcal . day-1 in summer and winter, respectively.