Nutrient intake of elite sailors during a solitary long-distance offshore race

The purpose of the present study was to determine the nutritional intake of 11 skippers during the four stages of a solitary long-distance offshore race. Body weight significantly decreased during the race (-1.31 +/- 0.32 kg, range 3.5 to 0.1 kg, p <.01). Total daily energy intake was 18.53 +/- 0.71 MJ x day-1 during the race, and it correlated negatively with the rate duration of each leg. Energy intake during the race was 19% greater than that determined for a subgroup of 5 sailors during a control period 2 months after the race. Nutrient intake expressed as percentage calories of total energy was estimated at 50%, 35%, and 15% for carbohydrate, fat, and protein, respectively. Voluntary fluid intake decreased with increasing race duration (p<.001). Despite high energy intakes, sailors lost body weight during the solitary offshore race. It was not possible to conclude that this change in body weight was related to fluid loss and/or a discrepancy between energy intake and energy expenditure.     

Thyroid function during a prolonged stay in Antarctica

Adaptation of the thyroid gland to the Antarctic environment was studied in nine healthy euthyroid tropical men of the Sixth Indian Antarctic Expedition during 1 year of their residence at polar latitudes. Circulatory concentrations of thyroid hormones, total T4 (TT4), total T3 (TT3), free T4 (FT4), free T3 (FT3), reverse T3 (rT3), thyroxine binding globulin (TBG), T3 uptake and thyroid stimulating hormone (TSH) were estimated in New Delhi and during the first week of each month of the stay in Antarctica. At the end of the Austral summer in March, the TT3 concentrations were found to be significantly lower (P < 0.01) compared to values recorded in New Delhi and showed a significant increase (P < 0.05) during the Austral winter in August. The mean TT3 concentrations from May to December were found to be significantly higher than the March or April values. Plasma TT4 and rT3 concentrations tended to decline in March but remained unaltered during the entire period in Antarctica. The FT4, FT3, TBG and T3 uptake did not show any appreciable change. Though, the TT3:TT4 ratio tended to decline in March and April suggesting decreased peripheral conversion of T4 to T3 as the possible mechanism for a decline in TT3 in March. physical exertion and prolonged exposure to extreme cold appeared to be the major contributory factors. The TSH concentration in March, April, November and December were found to be significantly higher than the New Delhi values. The morning as well as evening cortisol concentrations during the Austral winter were higher than the March values suggesting that cortisol rhythmicity was well maintained in Antarctica, albeit at a higher level. These observations indicated that the subtle changes in thyroid hormones during a prolonged stay at polar latitudes are related not only to the extreme cold but also to other factors such as physical activity, polar days and polar nights.     

The assessment of human body composition during weight reduction: evaluation of a new model for clinical studies

Adipose tissue, the logical target component in weight reduction regimens, was measured in five obese subjects during weight reduction, and in four normal weight controls. The two compartment model of Ljunggren, consisting of adipose tissue (AT) and adipose tissue-free mass (AFM), was further developed by finding experimental values for total water, extracellular water (ECW), lipid, and cell solids in 16 biopsied subjects. The AFM was estimated from body potassium content (40K counting) by use of an age/sex specific constant for the K content in the fat free body. Five obese subjects maintained for 46 days on regimens averaging 800 kcal/day had initial AT from 48% to 60% of body weight compared with AT 27% to 46% in four normal controls. Weight reductions averaged 17.4 kg (12% of initial weight), with approximately equal reductions in adipose tissue, adipose-free mass, and water. Initial fluid compartment ratios in the obese were unusually high (ECW:ICW in AFM was 0.74 +/- 0.23 [S.D.] compared with 0.42 +/- 0.05 in normals); these values returned toward normal (to 0.59 +/- 0.06) with weight reduction. The fact that it was possible to disclose a hitherto unappreciated abnormality of hydration in the adipose-free mass of obese subjects and its change toward normal with weight reduction, suggests that the adipose:adipose-free model may have a special utility when body composition measurements are used to monitor the effects of weight reduction regimens on various body constituents.     

The effect of estradiol on carbohydrate utilization during prolonged exercise in rats

Female--castrated and male-sham operated rats were subjected to five hours of swimming. It was found that estradiol administered to female rats promotes a supercompensatory pattern of glycogen recovery in the myocardium at the end of the fifth hour of exercise. The hormone markedly delayed the glycogen mobilization from the liver during the first hour of swimming. Glycogen level in m. biceps femoris was essentially unchanged by estradiol both at rest and during exercise. Estradiol signifcantly increased glycogen level in m. masseter of resting rats. Hypoglycaemia developing at the end of the fifth hour of exercise was less pronounced in the estradiol--treated female rats than in the animals from other groups. It may be concluded that estradiol exerts a "sparing" effect on carbohydrate reserves during exercise in rats.     

The development of adaptive body reactions after intensive physical loading]

The dependence between the activity parameters of muscarine antagonists in the prevention of haloperidol catalepsy in rats and those in tests characterizing the interaction of ligands and various subtypes of m-cholinoceptors was studied. It was established by constructing the mathematical dependence that blockade of m1-cholinoceptors increases, while that of m2-cholinoceptors reduces the antiparkinsonian activity of the drugs. The activity of the muscarine antagonist pentiphan in the prevention of haloperidol-induced catalepsy in rats exceeds the activity of such traditional antiparkinsonian drugs as cyclodol and amedin.     

Thyroiditic reactions during a course of thyroid cancer

The clinical, immunological, and immunoistochemical features of 10 thyroid cancers associated with intra and extra tumoral thyroiditis are described. These cases have been obtained from a review of 806 thyroidectomies. A proper distinction of the described pathology from the immunological and histological point of view, is emphasized, especially if compared with the prognosis of other thyroid cancers.     

The rate of movement of the topochemical interface during gas-solid reactions

The rate of recession of the topochemical interface between a porous core and the product layer is shown to be given by wherer _c is radial position of the interface,R(r_c) the rate of the chemical reaction at the interface and (dC _s/dr)|_{r s} is the gradient of concentration profile of solid reactant in the porous core at the interface. The integration of the above equation can sometimes be achieved analytically but can always be done numerically for even highly complex reaction mechanisms. The equation correctly reduces to previously known solutions when the inner core is impervious to gas diffusion. The utility of the equation is demonstrated by applying it to the industrially important multistage reduction process Mn₃O₄ → MnO — > Mn. The predictions from the theoretical model are compared successfully with experimental data for this reaction. Formerly Student in Department of Metallurgy, University of Strathclyde, Scotland.     

Tingible body macrophages in regulation of germinal center reactions

Tingible body macrophages (TBM), long thought simply as scavengers of apoptotic lymphocytes, are located in the unique microenvironment of germinal centers in close proximity to antigen-retaining follicular dendritic cells (FDC). Observations that TBM endocytose FDC-iccosomal (immune-complex coated bodies) antigen suggested that TBM might present this antigen and help regulate the germinal center reaction. To test for antigen presentation, the ovalbumin (OVA)-specific T(H) hybridoma, 3DO-54.8, which produces IL-2 on receiving effective presentation of OVA, were used as responders to OVA-bearing TBM. Results showed that OVA-bearing TBM failed to induce IL-2 production. Furthermore, addition of TBM to IL-2-inducing positive controls (B cells) not only failed to augment IL-2 production, but rather TBM significantly (55-90%) reduced B-cell induction of IL-2. We found that TBM were rich in prostaglandin by comparison with other nongerminal center lymph node macrophages and that addition of indomethacin to the cultures reversed the inhibitory effect of TBM. Depletion of TBM from enriched preparations, prior to addition to positive control cultures, also abrogated the inhibitory effect on IL-2 production. These data support the concept that TBM, within the unique microenvironment of germinal centers, may be specialized to downregulate the germinal center reaction.     

Alternate activity in the synergistic muscles during prolonged low-level contractions

The purpose of this study was to investigate the functional interrelationship between synergistic muscle activities during low-level fatiguing contractions. Six human subjects performed static and dynamic contractions at an ankle joint angle of 110 degrees plantar flexion and within the range of 90-110 degrees (anatomic position = 90 degrees) under constant load (10% maximal voluntary contraction) for 210 min. Surface electromyogram records from lateral gastrocnemius (LG), medial gastrocnemius (MG), and soleus (Sol) muscles showed high and silent activities alternately in the three muscles and a complementary and alternate activity between muscles in the time course. In the second half of all exercise times, the number of changes in activity increased significantly (P < 0.05) in each muscle. The ratios of active to silent periods of electromyogram activity were significantly higher (P < 0.05) in MG (4.5 +/- 2.2) and Sol (4.3 +/- 2.8) than in the LG (0.4 +/- 0.1), but no significant differences were observed between MG and Sol. These results suggest that the relative activation of synergistic motor pools are not constant during a low-level fatiguing task.     

The effect of sodium thiosulfate on nonspecific body resistance and on the immune reactions in acute acrylonitrile poisoning

Experiments on noninbred Wistar mice and rats showed that acute acrylonitrile (0.5 LD50) intoxication leads to decrease of nonspecific resistance of the organism and humoral and cellular immunity responses. The antidote sodium thiosulfate increases suppression of the responses under study.     

Incidence of adverse drug reactions in hospitalized patients: a meta-analysis of prospective studies

OBJECTIVE: To estimate the incidence of serious and fatal adverse drug reactions (ADR) in hospital patients. DATA SOURCES: Four electronic databases were searched from 1966 to 1996. STUDY SELECTION: Of 153, we selected 39 prospective studies from US hospitals. DATA EXTRACTION: Data extracted independently by 2 investigators were analyzed by a random-effects model. To obtain the overall incidence of ADRs in hospitalized patients, we combined the incidence of ADRs occurring while in the hospital plus the incidence of ADRs causing admission to hospital. We excluded errors in drug administration, noncompliance, overdose, drug abuse, therapeutic failures, and possible ADRs. Serious ADRs were defined as those that required hospitalization, were permanently disabling, or resulted in death. DATA SYNTHESIS: The overall incidence of serious ADRs was 6.7% (95% confidence interval [CI], 5.2%-8.2%) and of fatal ADRs was 0.32% (95% CI, 0.23%-0.41%) of hospitalized patients. We estimated that in 1994 overall 2216000 (1721000-2711000) hospitalized patients had serious ADRs and 106000 (76000-137000) had fatal ADRs, making these reactions between the fourth and sixth leading cause of death. CONCLUSIONS: The incidence of serious and fatal ADRs in US hospitals was found to be extremely high. While our results must be viewed with circumspection because of heterogeneity among studies and small biases in the samples, these data nevertheless suggest that ADRs represent an important clinical issue.     

The structure of the variability in operator psychophysiological indices at different levels of body work stress under conditions of prolonged activity]

It is shown in experimental investigations that variability of the task solution time (TST), intersystolic interval (ISI), pulse wave propagation time (PWPT), skin-galvanic reaction (SGR) decrease with an increase of the organism work tension. Specificity of the organism work tension in different analysis epochs (2 min, 30 min, 180 min) reflecting activity of inertia-different groups of regulator mechanisms in formation of dynamics of corresponding parameters is described. It is found that states of the organism in the "work-relax" terms differ most of all in changes of the decaminute variability of psychophysiological parameters (30- and 180-min analysis epochs), whereas information loading intensity differs in changes of a decasecond variability (2-min. epoch). It is shown that variability of TST and SGR of the 2-min analysis epoch and variability of ISI and PWPT of the 2- and 180-min epochs are the largest ones with different levels of the work tension. A significant expressiveness of 90-min-long periodicity of ISI, PWPT and sometimes of TST, SGR which exceeds expressiveness of quicker fluctuations is detected. A decrease of manifestation of naturally generated variability of psychophysiological parameters, including 90-min-long periodicity is connected with a decrease of rehabilitation processes in an organism. Under conditions of long-term (3h) continuous work the best productivity was revealed with a free work regime (in comparison with conditions of time scarcity and monotony), naturally generated variability of TST, including 90-min-long periodicity, being the most expressive.     

Right atrial pressure and forearm blood flow during prolonged exercise in a hot environment

Right atrial pressure (RAP) at rest is known to be reduced by an increase in skin blood flow (SkBF) in a hot environment. However, there is no clear evidence that this is so during exercise. To clarify the effect of the increase in SkBF on RAP during exercise, we measured forearm blood flow (FBF) (as an index of SkBF) and RAP continuously using a Swan-Ganz catheter in five male volunteers exercising on a cycle ergometer at 60% of peak aerobic power for 50 min in a hot environment (30 degrees C, relative humidity 20%). Cardiac output increased from 5.5 +/- 0.2 l/min at rest to 17.9 +/- 1.2 l/min (mean +/- SE, P < 0.01) in the first 10 min of exercise and then remained steady until the end of exercise. FBF did not change significantly during the first 5 min, but then increased from 2.7 +/- 0.5 ml/100 ml per min at rest to 10.8 +/- 1.7 ml/100 ml per min (P < 0.001) by 25 min as pulmonary arterial blood temperature (Tb) rose from 37.0 +/- 0.1 degrees C to 38.1 +/- 0.1 degrees C (P < 0.001). FBF then reached a plateau, despite a continuing increase in Tb. RAP increased significantly from 4.3 +/- 0.8 to 7.6 +/- 1.2 mm Hg (P < 0.001) during the first 5 min of exercise and then gradually declined to 6.1 +/- 1.0 mm Hg by 25 min (P < 0.001 vs. 5 min) and further to 5.7 +/- 1.0 mm Hg by 50 min, a value not significantly higher than at rest.(ABSTRACT TRUNCATED AT 250 WORDS)