Acetylcholinesterase Adaptation to Voluntary Wheel Running is Proportional to the Volume of Activity in Fast, but not Slow, Rat Hindlimb Muscles

Chronic enhancement of neuromuscular activity by forced exercise training programmes results in selective adaptation of the G₄ acetylcholinesterase (AChE) molecular form in hindlimb fast muscles of the rat, with only minor and non-selective AChE changes in the soleus. In order to shed further light on the physiological significance of this G₄ adaptation to training, we turned to a voluntary exercise model. The impact of 5 days and 4 weeks of voluntary wheel cage running on AChE molecular forms was examined in four hindlimb fast muscles and the slow-twitch soleus from two rat strains. Inbred Fisher and Sprague– Dawley rats, placed in live-in wheel cages, exercised spontaneously for distances which progressively increased up to an average of ∼3 and 18 km/day, respectively, by the end of week 4. Fast muscles responded to this voluntary activity by massive G₄ increases (up to 420%) with almost no changes in A₁₂, so that by week 4 the tetramer became the main AChE component of these muscles. The additional G₄ was composed primarily of amphiphilic molecules, suggesting a membrane-bound state. The G₄ content of fast muscles was highly correlated with the distance covered by the rats during the 5 days before they were killed ( r = 0.850-0.879, P < 0.001 in three muscles). The soleus muscle, in turn, responded to wheel cage activity by a marked selective reduction of its asymmetric forms—up to 45% for A₁₂. This A₁₂ decline, already maximal by day 5 of wheel cage running, showed no relationship with the distance covered. The present results constitute strong new evidence suggesting that the role of AChE in neuromuscular transmission is not limited solely to the rapid inactivation of just-released acetylcholine.     

Psoas abscess: Difficulties encountered

From 1961 to 1989, 67 patients underwent various surgical procedures for psoas abscess. Retrospective analysis was undertaken in an effort to determine optimal surgical therapy. Forty patients were cured with one operation. Twenty-one patients required two operations, four patients required three operations, and two patients required more than three operations. The reason for failure of treatment was failure to resect the diseased bowel or to drain the psoas abscess adequately. A technique to recognize and treat the abscess definitively will be illustrated. The most common etiologies were Crohn's disease in 49 patients, postoperative sepsis in eight patients, and complications of renal disease in four patients. The length of hospital stay ranged from 5 to 392 days (mean, 26 days). There were two deaths. Failure to recognize and treat psoas abscess results in considerable morbidity.Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, St. Louis, Missouri, April 29 to May 4, 1990.     

Biochemical changes after a qigong program: lipids, serum enzymes, urea, and creatinine in healthy subjects.

BACKGROUND: The aim of the present study was to analyze the effects of a qigong training program on blood biochemical parameters. MATERIAL/METHODS: Twenty-nine healthy subjects participated in the study of whom 16 were randomly assigned to the experimental group and 13 to the control. The experimental subjects underwent daily qigong training for one month. Blood samples for the quantification of biochemical parameters (total cholesterol, HDL, LDL, triglycerides, phospholipids, GOT, GPT, GGT, urea, creatinine) were taken before and after the training program. As statistical analysis, ANCOVA was performed. RESULTS: Statistically significant differences were found showing that the experimental group had lower serum levels of GOT (glutamic-oxaloacetic transaminase), GPT (glutamic-pyruvic transaminase), and urea and that there was a trend towards significance in GGT (gamma-glutamyltransferase). CONCLUSIONS: This study demonstrates that after practicing qigong for the short period of one month, noteworthy changes in several blood biochemical parameters were induced. While it is tempting to speculate on the relevance and implications of these biochemical variations, further investigation is needed to elucidate the scope of these findings.     

Chemotherapy and cardiotoxicity in older breast cancer patients: a population-based study.

PURPOSE: Adjuvant chemotherapy, especially with anthracyclines, is known to cause acute and chronic cardiotoxicity in breast cancer patients. We studied the cardiac effects of chemotherapy in a population-based sample of breast cancer patients aged > or = 65 years with long-term follow-up. PATIENTS AND METHODS: In the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, we analyzed treatments and outcomes among women > or = 65 years of age who were diagnosed with stage I to III breast cancer from January 1, 1992 to December 31, 1999. Propensity scores were used to control for baseline heart disease (HD) and other known predictors of chemotherapy, and Cox proportional hazards models were used to estimate the risk of cardiomyopathy (CM), congestive heart failure (CHF), and HD after chemotherapy. RESULTS: Of 31,748 women with stage I to III breast cancer, 5,575 (18%) received chemotherapy. Chemotherapy was associated with younger age, fewer comorbidities, hormone receptor negativity, multiple primary tumors, and advanced disease. Patients who received chemotherapy were less likely than other patients to have pre-existing HD (45% v 55%, respectively; P < .001). The hazard ratios for CM, CHF, and HD for patients treated with doxorubicin (DOX) compared with patients who received no chemotherapy were 2.48 (95% CI, 2.10 to 2.93), 1.38 (95% CI, 1.25 to 1.52), and 1.35 (95% CI, 1.26 to 1.44), respectively. The relative risk of cardiotoxicity among patients who received DOX compared with untreated patients remained elevated 5 years after diagnosis. CONCLUSION: When baseline HD was taken into account, chemotherapy, especially with anthracyclines, was associated with a substantially increased risk of CM. As the number of long-term survivors grows, identifying and minimizing the late effects of treatment will become increasingly important.     

Antifibrinolytics in orthotopic liver transplantation: current status and controversies.

This article reviews the current status and controversies of the 3 commonly used antifibrinolytics-epsilon-aminocaproic acid, tranexamic acid and aprotinin-during liver transplantation. There is no general consensus on how, when or which antifibrinolytics should be used in liver transplantation. Although these drugs appear to reduce blood loss and decrease transfusion requirements during liver transplantation, their use is not supported uniformly in clinical trials. Aprotinin has been studied more extensively in clinical trials and appear to offer more advantages compared to two other antifibrinolytics. Because of the diverse population of liver transplant recipients and the potential adverse effects of antifibrinolytics, especially life-threatening thromboembolism, careful patient selection and close monitoring is prudent. Further studies addressing the risks and benefits of antifibrinolytics in the setting of liver transplantation are warranted.     

Transplantation for adults with congenital heart disease.

Heart transplantation is a recognised treatment for end-stage heart failure of any cause including congenital heart disease. Congenital heart disease has contributed relatively little to the adult heart transplant activities in the past two decades. However, this is likely to change as an increasing number of children with congenital heart disease reach adulthood because of the advances in paediatric cardiology and surgery. Some of these grown-ups with congenital heart disease (GUCH patients) will need transplantation for late myocardial dysfunction either secondary to uncorrected lesions, or despite previous repair or palliative surgery. These patients are managed along the same clinical principles as those with cardiac failure of other aetiologies, despite the lack of any evidence to support this approach. Nevertheless, they introduce new challenges. First, some may have pulmonary vascular disease and require heart-lung transplantation, or lung transplantation combined with repair of their cardiac defects. Second, those with failing Fontan circulation are usually much sicker than other transplant candidates, with protein-losing enteropathy along with renal and hepatic dysfunction. Third, a suitable donor organ may not be found due to elevated levels of antibodies in response to previous blood transfusions and possibly the previous implantation of homografts. Fourth, the operation may be technically difficult because of the presence of adhesions secondary to previous operations, collaterals, and unusual anatomy. Fifth, postoperative care may be complicated because of predisposition to bleeding, infection and pulmonary hypertension, and the presence of residual aortopulmonary collaterals resulting in a significant left-to-right shunt. Despite a higher early mortality, the overall results of heart transplantation so far have been encouraging with survivals similar to that of adults with acquired heart disease and that of the paediatric population. However, this may change as the proportion of high-risk patients (failing Fontans) increases. GUCH patients with Eisenmenger's syndrome may be offered lung transplantation with repair of the cardiac defect or heart-lung transplantation. However, because of the limited success of these approaches, and improved management of pulmonary hypertension, patient selection remains difficult.     

Laryngeal edema associated with the ProSeal™ laryngeal mask airway in upper respiratory tract infection

PURPOSE: We report an unusual case of vocal cord edema associated with the use of a ProSeal laryngeal mask airway (PLMA) in an adult patient with an undiagnosed upper respiratory tract infection (URTI). CLINICAL FEATURES: A 55-yr-old woman had fixation of a radial fracture under general anesthesia with muscle relaxation. She developed audible wheezing 30 min after PLMA insertion. Bronchoscopic examination revealed significant vocal cord edema. Adequate ventilation was possible at increased airway pressures, and the administration of dexamethasone 4 mg iv produced clinical resolution of the stridor and airway obstruction. The patient admitted to having mild symptoms of an URTI on postoperative questioning. CONCLUSION: Airway hyperreactivity secondary to the URTI is the most likely etiological factor; other possibilities include trauma from insertion and chemical irritation. Although pediatric studies suggest that the LMA-Classic carries less risk than endotracheal intubation in the presence of URTI, this case report demonstrates that caution is still warranted when using supraglottic airways. The PLMA permitted effective ventilation despite increased airway resistance; nevertheless its role in patients with URTI is unclear. It is possible that the bulkier cuff design of the PLMA, compared to that of the LMA-Classic, may have partly contributed to the development of edema in this setting.