动态观察PSA和F PSA/PSA对诊断前列腺癌的临床价值

为了评价游离前列腺抗原（F PSA）／前列腺抗原（PSA）比值和PSA动态变化（年变化率）在前列腺癌诊断中的应用价值。本文应用ELISA追踪检测PSA在4～10μg／L范围患者在不同时段内PSA水平，并与正常人进行对照，利用ROC曲线，评价FPSA／PSA比值和PSA年变化率两项指标在前列腺癌诊断时的预示价值。结果表明：前列腺癌患者的FPSA／PSA比值和PSA年变化率与非前列腺癌组之间具有显著性差异（P〈0．001），当FPSA／PSA比值的临床判断值为0．21时，诊断灵敏度为93．5％，特异性为91.4％；当PSA年变化率的临床判断值为0．85％。诊断灵敏度为82．6％，诊断特异性为97．9％。前列腺增生患者FPSA／PSA比值与正常人之间无显著性差异（P〉0．05），而PSA年变化率与正常人比较具有显著性差异（P＜0．001）。提示FPSA／PSA比值和PSA年变化率有助于PSA在4～10μg／L范围的患者前列腺癌的诊断。     

Efficiency of work performance and contraction velocity in isotonic tetani of frog sartorius

Mechanical work, ATP, ADP, PC, free creatine and lactate concentrations were determined on IAA poisoned frog sartorii tetanically stimulated in humidified N, at 10°C in isotonic conditions (0.25 or 0.45 P₀). Tetanus duration was 0.35 s, number of tetani was varied from 0 (rest) to 25 (exhaustion). The mechanical work performed per mole ATP+PC split (W _P ^* ) amounted on the average to 16.7 kJ/mol. It was observed, however, that w _p ^* increased from about 13 to about 24 kJ/mol with decreasing ATP concentration from about 2 (resting value) to about 1 mol/g and that this decrease in ATP was associated with a decrease of the shortening (and relaxation) speed of the muscle to about 30% of the values observed on the first tetanus. It is concluded that the thermodynamic efficiency of muscle contraction, calculated from the ratio of w _P ^* (measured) to the thermodynamic affinity (free energy change) of ATP hydrolysis (estimated) increases from about 0.3 to about 0.5 with decreasing ATP concentration and shortening speed.This work was supported by the Fonds National Suisse de la Recherche Scientifique, Grants 3.332.78 and 3.364.0.82     

Reducing the time of sperm-oocyte interaction in human in-vitro fertilization improves the implantation rate

Human oocyte development was evaluated after a reduced timeexposure to spermatozoa in vitro. A total of 119 patients wereassigned to two study groups in a randomized prospective studyin which each patient‘s oocytes were exposed to spermatozoafor either 1 h (group 1 – 58 patients) or the standard16 h incubation period (group 2 – 61 patients). The fertilizationrate obtained in group 1 was higher than in group 2 (285/393,73%, and 272/410, 66% respectively), suggesting that the spermatozoa-oocyteinteraction occurs within 1 h. This was confirmed in a studyin vitro using fluorescently labelled spermatozoa and normaloocyte-cumulus complexes. Spermatozoa enter the cumulus complexwithin 15 min, traverse the cumulus layer within 3 h, and firstappear in the oocyte cortex at 4 h post-insemination. The incidenceof polyspermy was higher in oocytes exposed to spermatozoa for16 h (3%) than for 1 h (1%). There was no difference in thecleavage rate or morphological characteristics of embryos fromboth study groups. However, when evaluating the timing of embryodevelopment, group 1 generated a significantly higher percentageof four to five cell embryos when compared to group 2 (55 versus39%; P < 0.001), documented at 40 h post-insemination. Theimplantation and pregnancy rates for group 1 were 11 and 28%,while the corresponding rates for group 2 were 8 and 15%. Thissuggests that a reduced exposure of oocyte to spermatozoa favoursembryo viability, possibly due to a decrease in potential damagefrom sperm metabolic waste products.     

Calcium homeostasis and glucose uptake of murine myotubes exposed to insulin,caffeine and 4‐chloro‐m‐cresol

The modulation of glucose uptake by cytosolic calcium and the role of insulin on calcium homeostasis in insulin‐target cells are incompletely understood and results are contradictory. To address this issue, we used the C2C12 murine skeletal muscle cell line model and examined the influence of caffeine and 4‐chloro‐m‐cresol, two ryanodine receptor agonists known to mobilize intracellular calcium stores and increase cytosolic free calcium concentration. We followed ⁴⁵calcium efflux, a validated indicator of cytosolic calcium concentration, and 3‐O‐methyl‐[1–³H]‐d ‐glucose uptake in parallel. We also determined if insulin incubation affected ⁴⁵calcium influx rate. A 30‐min treatment by 1 μm insulin highly significantly increased ⁴⁵calcium efflux by 8.5% (P = 0.0014), despite a significant reduction of ⁴⁵Ca²⁺ influx already measurable after 20 and 30 min of insulin stimulation (?16.6%, P = 0.0119 and ?21.3%, P = 0.0047, respectively). Caffeine (1–20 mm ) and 4‐chloro‐m‐cresol (0.05–10 mm ) concentration‐dependently increased ⁴⁵calcium efflux, the latter being more potent and efficacious. These agents, in a concentration‐dependent manner, inhibited both basal and, more potently, insulin‐stimulated glucose uptake. This resulted in a negative correlation of glucose uptake and ⁴⁵calcium efflux (r > 0.95, P < 0.001). This effect was ～5 times greater for caffeine than for 4‐chloro‐m‐cresol, suggesting a calcium‐independent part of the glucose uptake inhibition by caffeine. In our in vitro model of cultured muscle cells, insulin appears to prevent calcium overload by both stimulating efflux and inhibiting cell storage. This effect, taken together with the observed inhibitory, inverse relationship between ⁴⁵calcium efflux and glucose uptake, contributes to describing the complex insulin–calcium interplay involved in target cells.     

Effect of skin temperature on the ion reabsorption capacity of sweat glands during exercise in humans

The effect of skin temperature on the ion reabsorption capacity of sweat glands during exercise in humans is unknown. In this study, eight healthy subjects performed a 60-min cycling exercise at a constant intensity (60% VO_2max) under moderate (25°C) and cool (15°C) ambient temperatures at a constant relative humidity of 40%. The sweating rate (SR), index of sweat ion concentration (ISIC) by using sweat conductivity, esophageal temperature (Tes), mean skin temperature, and heart rate (HR) were measured continuously under both ambient temperatures. The SR and ISIC were significantly lower at the cool ambient temperature versus the moderate temperature. There were no significant differences in the changes in HR and esophageal temperature between these ambient temperature conditions, while the mean skin temperature was significantly lower at the cool ambient temperature by almost 3°C (P<0.05). The slopes of the relationships between Tes and the SR and ISIC were significantly lower and the thresholds of these relationships were significantly higher at the cool ambient temperature (P<0.05). The ion reabsorption capacity of the sweat glands was significantly lower (P<0.05) in a cool environment (0.21±0.04 vs. 0.52±0.06 mg/cm²/min at 15 and 25°C, respectively) as evaluated using the relationships for SR and ISIC. The results suggest that the ion reabsorption capacity of the sweat glands is influenced by skin temperature during exercise in humans.     

Mechanisms of antagonistic action of internal Ca2+ on serotonin-induced potentiation of Ca2+ currents in Helix neurones

The influence of internal Ca²⁺ ions has been investigated during intracellular perfusion of isolated neurones from pedal ganglia of Helix pomatia in which serotonin (5-HT) induces a cyclic-adenosine-monophosphate-(cAMP)-dependent enhancement of high-threshold Ca²⁺ current (I _Ca). Internal free Ca²⁺ ([Ca²⁺]_i) was varied between 0.01 and 10 M by addition of Ca²⁺-EGTA [ethylenebis(oxonitrilo)tetraacetate] buffer. Elevation of [Ca²⁺]_i depressed the 5-HT effect. The dose/ effect curve for the Ca²⁺ blockade had a biphasic character and could be described by the sum of two Langmuir's isotherms for tetramolecular binding with dissociation constants K _d1=0.063 M and K _d2=1 M. Addition of calmodulin (CM) antagonists (50 M trifluoperazine or 50 M chlorpromazine), phosphodiesterase (PDE) antagonists [100 M isobutylmethylxanthine (IBMX) or 5 mM theophylline] and protein phosphatase antagonists [2 M okadaic acid (OA)] in the perfusion solution caused anticalcium action and modified the Ca²⁺ binding isotherm. Using the effect of OA and IBMX, two components of the total Ca²⁺ inhibition were separated and evaluated. In the presence of one of these blockers tetramolecular curves with K _d1=0.04 M and K _d2=0.69 M were obtained describing the activation of the retained unblocked enzyme — PDE or calcineurin (CN) correspondingly. The sum of these isotherms gave a biphasic curve similar to that in control. Leupeptin (100 M), a blocker of Ca²⁺-dependent proteases did not influence the amplitude of 5-HT effect, indicating that channel proteolysis is not involved in the depression. Our findings show that the molecular mechanism of Ca²⁺-induced suppression of the cAMP-dependent upregulation of Ca²⁺ channels is due to involvement of two Ca²⁺-CM-dependent enzymes: PDE reducing the cAMP level, and CN causing channel dephosphorylation. No other processes are involved in the investigated phenomenon at a Ca²⁺ concentration of less than or equal to 10 M.     

Role of the kallikrein-kinin system of the kidneys in sodium and water transport and its modification by indomethacin

Direct correlation was found in intact rats between the kallikrein activity of the urine, on the one hand, and the diuresis, sodium excretion, and ability of the kidneys to concentrate the urine on the other hand. Small doses of indomethacin (2 mg/kg for 5 days) increased the kallikrein activity of the urine four-fold and, at the same time, increased the diuresis; large doses (5 mg/kg for 5 days) lowered the kallikrein activity of the urine and halved the diuresis, reduced the sodium excretion by two-thirds, and depressed the ability of the kidneys to concentrate the urine. Indomethacin may perhaps modify the synthesis not only of prostaglandins, but also of kallikrein, and this is reflected in the state of the kidney function.All-Union Cardiological Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR E. I. Chazor.) Translated from Byulleten' Éxperimental'noi Biologii i Meditsiny, Vol. 83, No. 4, pp. 399–400, April, 1977.     

Origin of olfacto-gustatory alliesthesia: Intestinal sensitivity to carbohydrate concentration?

Gustatory and olfactory alliesthesia was observed in nine healthy adult humans who received on three different days an intragastric load of 50 g glucose dissolved into various amounts of water in order to make 100, 200 and 400 ml of solution. Maximal alliesthesia to sweet stimuli was observed with the smallest volume, i.e., highest concentration. Comparison of these results with previous results [7], obtained not by varying the volume but by varying the glucose mass, shows identity. Maximal alliesthesia to olfactory anchovy and Viandox^R was also observed after ingestion of the most concentrated gastric load. Maximal negative alliesthesia was observed about 45 min after the gastric load; thereafter alliesthesia tended to decrease. A gastric 200 ml load containing 40 g Mannitol, a nonabsorbed sugar, was followed by a strong negative alliesthesia to alimentary stimuli. Ten g glucose in 20 ml solution produced a more intense and rapid alliesthesia when injected into the duodenum than when injected into the stomach. It may be concluded that postinjective negative alliesthesia for alimentary stimuli can be caused by intraduodenal concentration of nutrients, probably sensed by duodenal nervous chemoreceptors.