Nutrition-aging influence of catecholamine-promoted lipolysis

Male SPF Fischer 344 rats were fed ad lib. (group A) or 60% ad lib. intake (group R) from 6 wk of age. The group R rats had a markedly increased median length of life. Starting at 6 mo of age, rats were periodically killed and free adipocytes prepared from the epididymal and perirenal depots. The free adipocytes were used for the in vitro study of the effects of age on the promotion of lipolysis by catecholamines. At 6 mo of age, the response of the adipocytes from group A and group R rats was similar when the data are expressed as μmole glycerol released/10⁶ adipocytes. With increasing age, however, this lipolytic response to catecholamines of group A rats markedly declined. The catecholamine-stimulated lipolysis/10⁶ adipocytes from group R rats changed little between 6 and 18 mo of age, and the decline noted after 18 mo of age was less marked than that occurring in adipocytes from group A rats. The data based on rates of lipolysis/10⁶ adipocytes indicate that it is the lifelong nutritional history of a rat population that determines the age-related changes in responsiveness of adipocytes to catecholamines. However, if the data are expressed per sq mm of adipocyte surface, a somewhat different picture emerges. These data are presented and their relevance is discussed.     

Apolipoprotein B immunochemical heterogeneity in dialysed patients with chronic renal failure and patients with coronary artery stenosis

Serum cholesterol, triglyceride, apolipoprotein B (apo B) and the cholesterol and phospholipid content of apo-B-containing particles was determined in 41 male patients on dialysis for chronic renal failure, in 41 male patients with coronary artery disease selected on the basis of a total cholesterol level below 6.72 mmol/l and in 41 male control subjects of similar age. Apo B was assessed as total B protein determined using polyclonal antibodies and also by measuring the expression of epitopes recognized by three different monoclonal antibodies (BL3, BL5 and BL7). Triglyceride was increased (p less than 0.01) and cholesterol was decreased (p less than 0.01) in the dialysed patients with chronic renal failure. Total apo B was similar in the three tested groups while the expression of the BL7 epitope was increased in the group of dialysed patients with chronic renal failure (p less than 0.001). The expression of BL3 and BL5 epitopes was increased in patients with coronary artery disease (BL3: p less than 0.05; BL5: p less than 0.02) but not in dialysed patients with chronic renal failure. These results suggest an abnormal composition and an immunological heterogeneity of apo-B-containing lipoprotein particles in patients with coronary artery stenosis and in dialysed patients with chronic renal failure.     

Improvement of diaphragmatic function by a thoracic extradural block after upper abdominal surgery

The effects on diaphragmatic function of a thoracic epidural block were assessed in 13 patients after upper abdominal surgery (UAS). Lung volumes and tidal changes in chest wall circumferences and gastric (delta Pgas) and esophageal (delta Pes) pressures were measured pre- and postoperatively. Volume displacement of the abdomen divided by tidal volume (delta VAB/VT) and delta Pgas/delta Pes were taken as indices of the diaphragmatic contribution to tidal breathing. These respiratory variables were obtained in the postoperative period, before and after epidural injection of 0.5% plain bupivacaine to achieve a block up to the T4 segment. UAS was constantly associated with a decrease in VT, delta VAB/VT, delta Pgas/delta Pes, and forced vital capacity (FVC). Epidural block was associated with an increase in VT, delta VAB/VT, and FVC. delta Pgas and delta Pgas/delta Pes returned to their preoperative values. It is concluded that: 1) diaphragmatic dysfunction observed after UAS is partially reversed by thoracic epidural block; and 2) that inhibitory reflexes of phrenic activity arising from the abdominal compartment (abdominal wall and/or viscera) could be involved in this diaphragmatic dysfunction.     

Refractory metastatic breast cancer: salvage therapy with fluorouracil and high-dose continuous infusion leucovorin calcium

Sixty women with metastatic breast cancer refractory to at least one chemotherapeutic regimen were treated with fluorouracil (FUra) and high-dose continuous infusion folinic acid (leucovorin calcium). One complete remission lasting 8.7 months and nine partial remissions ranging in duration from 1.3 to 12.8 months were observed, for an objective response rate of 17% (95% confidence interval for response, 8% to 27%). Nine of the ten responding patients had metastatic disease that had objectively progressed on previous chemotherapy with a FUra-containing regimen. This program was well tolerated, with toxicities consisting mainly of stomatitis and granulocytopenia. These results suggest that augmentation of the reduced folate levels of metastatic breast carcinomas may enhance the effectiveness of the fluoropyrimidines in this disease.     

The protection of creatine kinase MM sub-bands by EDTA during storage

We examined the effect of a 5 mmol/1 concentration of EDTA on the stabilization of the five serum creatine kinase MM isoenzymes, resolved by thin-layer isoelectric focusing.In patient sera, total CK and CK-MB activities were stable during storage of the samples for two months at 4° C even in the absence of EDTA. However, EDTA stabilized the labile MM and MM1 sub-bands, which are the first to appear in the blood after the release from the damaged tissue and its addition to blood samples intended for determining the MM sub-band pattern is recommended.The stabilizing effect of EDTA was emphasized at higher temperatures. EDTA protected the CK-MM pattern in myocardium extracts made in normal serum and incubated at 37°C during 40 h, but was unnecessary when myocardium was homogenized in heat-inactivated serum. It is thought that EDTA could act by inhibiting a heat-labile component of human serum.     

BAEP latency changes during nocturnal sleep are not correlated with sleep stages but with body temperature variations

Serial BAEPs and polysomnograms were recorded during nocturnal sleep in 8 normal subjects. Wave V latency and the I-V interval were found to increase significantly during stages II, III + IV and paradoxical sleep when compared to waking. Trend curves of BAEP latencies showed that these shifts were independent of sleep stages and reversed at the end of the night. BAEP changes were found to be related to physiological hypothermia during the night.