Alterations in contractility and intracellular Ca2+ transients in isolated bundles of skeletal muscle fibers from rats with chronic heart failure

To determine if chronic heart failure (CHF) leads to functional or structural alterations of skeletal muscle, we compared intracellular Ca2+ signaling, contractility, and the rate of fatigue development, together with electron microscopy (EM), in skeletal muscle preparations from rats with myocardial infarction-induced CHF versus sham-operated control rats. Bundles of 100 to 200 cells were dissected from the extensor digitorum longus (EDL) muscle of control (n = 13) and CHF (n = 19) rats and were either loaded with aequorin or fixed for EM. Muscles from CHF rats exhibited depressed tension development compared with control muscles during twitches (1.4 +/- 0.2 versus 2.8 +/- 0.7 g/mm2, P < .05) and maximal tetani (5.3 +/- 1.4 versus 10.7 +/- 2.4 g/mm2, P < .05). Depressed tension in CHF was accompanied by reduced quantitative [Ca2+]i release during twitches (0.7 +/- 0.1 versus 0.4 +/- 0.1 microM, P < .05) and during maximal tetani (1.8 +/- 0.3 versus 0.9 +/- 0.2 microM, P < .05). Skeletal muscle from CHF rats also demonstrated prolonged intracellular Ca2+ transients during twitches and tetani and accelerated fatigue development. EM revealed a lack of cellular atrophy in the CHF rats. In conclusion, EDL skeletal muscle from rats with CHF had intrinsic abnormalities in excitation-contraction coupling unrelated to cellular atrophy. These findings indicate that CHF is a condition accompanied by EDL skeletal muscle dysfunction.     

The effect of intermittent pneumatic compression devices on intraoperative blood loss during radical prostatectomy and radical cystectomy

Intermittent pneumatic compression devices are a widely used, effective and presumed risk-free method of deep venous thrombosis prophylaxis, presumably by increasing peak venous blood velocity, and stimulating local and systemic fibrinolysis. We investigated whether intermittent pneumatic compression devices had any effect on intraoperative blood loss or transfusion during radical pelvic urological surgery. To our knowledge no previous study has addressed these issues. Records were reviewed for patients undergoing radical retropubic prostatectomy or radical cystectomy with diversion from 1985 to 1990. A total of 91 cases was reviewed: 38 radical retropubic prostatectomies and 53 radical cystectomies with diversion (34 male and 19 female patients). There were 59 patients with intermittent pneumatic compression devices (29 radical retropubic prostatectomies and 30 radical cystectomies with diversion) and 32 without intermittent pneumatic compression devices (9 radical retropubic prostatectomies and 23 radical cystectomies with diversion). Intraoperative blood loss and transfusions were calculated for each group with and without intermittent pneumatic compression devices. No clinically apparent lower extremity deep venous thrombosis or pulmonary embolus was diagnosed in any patient. For the group with intermittent pneumatic compression devices mean intraoperative blood loss was 2,541 ml. (range 700 to 8,850) versus 1,807 ml. (range 450 to 5,100) without a device, for a statistically significant difference of 734 ml. (p = 0.005). When 5 patients with excessive intraoperative blood loss (more than 5,000 ml.) were excluded the statistically significant difference was maintained. When comparing radical retropubic prostatectomy and radical cystectomy with diversion, with and without intermittent pneumatic compression devices, blood loss was greater for the group with a device for each procedure. Differences in intraoperative blood loss were independent of sex or tumor stage. Intraoperative transfusions were increased by approximately 0.6 units per patient with the device. Our study suggests that intermittent pneumatic compression devices may increase blood loss during a radical pelvic operation.     

HIV seroprevalence in sexually transmitted disease clients in a low-prevalence southern state. Evidence of endemic sexual transmission

Seventy male Fischer 344 (F-344) rats were treated with s.c. injection of (-)deprenyl (0.5 mg/kg, n = 35) or physiological saline (n = 35) 3 times a week from the age of 18 months until the time of their natural death. The fifty percent survival time was 28 months in control animals and 30 months in the deprenyl treated group. The mean survival time after the start of treatment (18 months) and after 24 months were 378.3 +/- 97.4 days (mean +/- SD) and 196.3 +/- 97.4 days, respectively, in deprenyl treated rats and 328.7 +/- 108.8 days and 146.7 +/- 108.7 days in control rats. The increases in average life expectancies caused by deprenyl treatment (15% from 18 months and 34% from 24 months) were both statistically significant (P < 0.05, two-tailed t-test). The average body weights were comparable for both groups but the variation of body weight was greater in control groups, thus excluding the possibility that the life prolonging effect of deprenyl results from reduced dietary intake. The results confirm those of two previous studies (1,2) which reported a significant life prolonging effect of deprenyl in aged rats and lend added support to the results of a study on male F-344 rats where the effect was only marginally significant (16% increase after 24 months, P = 0.048 by one-tailed t test) (2).     

Medullary carcinoma of the thyroid

Medullary carcinoma is an unusual malignant neoplasm. The cell of origin is considered to be the C-cell which is derived from the ultimobranchial body and neural crest. The tumor is solid and has characteristic amyloid in the stroma. The lesion usually presents as a neck mass, and multicentricity is not unusual. In some patients diarrhea may be an important presenting symptom. Serum calcitonin is typically elevated and is important in the diagnostic confirmation. About 10 percent of the cases are part of a familial endocrine syndrome which includes pheochromocytomas, mucosal neuromas, and other endocrine gland adenomas. Frequent multicentricity and early cervical lymphatic and systemic metastases necessitate total thyroidectomy and radical neck dissection. Prognosis varies from a rapid demise to long term survival.     

Vasodilation with adenosine or sodium nitroprusside after coronary artery bypass surgery: a comparative study on myocardial blood flow and metabolism

The effects of adenosine and sodium nitroprusside (SNP) on central hemodynamics and myocardial blood flow and metabolism were investigated postoperatively after elective coronary artery bypass (CABG) surgery in ten sedated and mechanically ventilated patients in the intensive care unit. During three consecutive 15-min periods, SNP (0.8 +/- 0.1 micrograms.kg-1 x min-1), adenosine (88.9 +/- 13.3 micrograms.kg-1 x min-1), and then again SNP (0.7 +/- 0.1 micrograms.kg-1 x min-1) were infused to control postoperative hypertension at a mean arterial pressure of approximately 80 mm Hg. Systemic and pulmonary hemodynamics and global (coronary sinus flow, CSF) as well as regional (great cardiac vein flow, GCVF) myocardial blood flow and metabolic variables were measured. During adenosine infusion, in comparison to SNP, heart rate was unchanged, stroke volume index and cardiac index increased (24% and 32%, respectively), and the systemic vascular resistance index decreased (-26%). Mean pulmonary arterial pressure (24%) as well as pulmonary capillary wedge pressure (27%) and central venous pressure (18%) were higher with adenosine compared to SNP. Adenosine also increased CSF and GCVF (108% and 103%, respectively) without altering the CSF/GCVF flow ratio compared to SNP. Furthermore, adenosine increased the coronary oxygen content (51%) and decreased the arterio-great cardiac vein oxygen content difference (-48%) without changing regional myocardial oxygen consumption, indicating a more pronounced hyperkinetic myocardial circulation compared to SNP. In addition, adenosine infusion decreased arterial PO2 (-11%) and increased the intrapulmonary shunt fraction (57%). The PR interval time of the electrocardiogram was prolonged (12%) and the ST segment was more depressed during adenosine infusion compared to SNP.(ABSTRACT TRUNCATED AT 250 WORDS)