Retroperitoneal Laparoscopic Nephrectomy in Children

Retroperitoneal pediatric laparoscopic nephrectomy is described in 3 patients requiring 3 to 5 hours with an estimated blood loss of 10 to 60 cc. The children returned to school within 7 days postoperatively. Advantages of this procedure include the avoidance of intraoperative repositioning of the patient and easy conversion to an open lumbodorsal approach, if necessary; early laparoscopic visualization of the renal artery; applicability in cases of previous abdominal surgery, and avoidance of intraperitoneal adhesion.     

Intracellular Ca2+ buffers disrupt muscarinic suppression of Ca2+ current and M current in rat sympathetic neurons.

The role of intracellular Ca2+ concentration ([Ca2+]i) in the muscarinic suppression of Ca2+ current and M-type K+ current has been investigated in isolated rat sympathetic neurons using the whole-cell patch-clamp technique and fura-2 fluorescence measurements. Muscarinic stimulation suppressed currents without raising [Ca2+]i. Nonetheless, intracellular bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetate (BAPTA) (11-12 mM), a Ca2+ chelator, reduced Ca2(+)-current suppression from 82 to 15%. For the latter, we explain the BAPTA action by a requirement for a certain minimum [Ca2+]i for continued operation of the pathway coupling muscarinic receptors to M-type K+ channels. The pathway coupling muscarinic receptors to Ca channels also showed some dependence on [Ca2+]i, but there may also be a blocking action of BAPTA that is independent of Ca2+ chelation.     

Effects of a long-distance run on cardiac markers in healthy athletes.

BACKGROUND: Running a marathon is a stressful event for athletes. Limited research exists on the role of cardiac markers during such a strenuous event. The aim of this study was to investigate detailed changes in cardiac markers before and after a long-distance run. METHODS: We studied 25 male and 2 female runners (age 34-64 years) who were running the Visé-Maastricht-Visé marathon. Blood samples were drawn just before and immediately after finishing the marathon. An additional blood sample was collected 24 h later. RESULTS: Running the marathon led to a significant increase in cortisol. This returned to baseline values 24 h after the marathon. There was a slight increase in brain natriuretic peptide (BNP); however, this was not statistically significant. On the contrary, the N-terminal fragment of BNP (NT-pro-BNP) was significantly increased immediately after the run and was normalized 24 h later in 26 out of 27 runners (96%). The magnitude of the transient elevations in BNP and NT-pro-BNP increased with the age of the athletes. Furthermore, in 9 out of 27 runners there was a significant increase in troponin T. However, in all these runners this increase was transient and troponin-T levels returned to baseline values 24 h after the marathon. CONCLUSIONS: Running a marathon significantly increases NT-pro-BNP levels in healthy adults. This increase could be partially attributed to cardiac stress. The transient increases in BNP, NT-pro-BNP and troponin T are more likely to reflect myocardial stunning than cardiomyocyte damage. It seems that the magnitude of the increase in BNP could serve as a marker of the biological age of the myocardium.     

Training and assessment of laparoscopic skills.

Laparoscopic surgery is gaining popularity among the surgical community. While its prevalence expands, the need for reliable training and assessment tools is becoming increasingly important. Laparoscopic skills are not an innate behavior, nor can they be easily mimicked, and can only be acquired through hands-on training. A consensus exists among physicians that establishment and evaluation of technical skill in surgical training programs are inadequate and in need of improvement. A validated, reliable bench model that could train and assess could be standardized and provide numerous benefits including determination of which medical students should consider a career in surgery, valuable feedback to residents, a tracking mechanism of resident performance, a possible certification and recertification tool, and to allow for interinstitutional comparison. To this end, several potentially successful bench models testing dexterity, hand-eye coordination, and depth perception have been developed. A few models have been proven to be both valid and reliable indicators of technical skill. Although the future remains uncertain, enough groundwork has been laid to begin incorporating technical skill training and assessment into surgical training programs.     

Buserelin-mediated osteoporosis: Effects of restoring estrogen on bone resorption and whole body calcium content in the rat

Summary In the rat, prolonged administration of the luteinizing, hormone-releasing hormone agonist buserelin (25 μg/kg body wt/day s.c.) lowers blood estradiol, raises bone resorption, and induces osteopenia. The present study was undertaken to determine whether withdrawal of buserelin normalizes blood estradiol, slows bone resorption, and corrects buserelin-mediated osteopenia. Four groups of female rats with⁴⁵Ca-labeled bones were studied: group 1A received 0.2 ml saline s.c. daily for 4 weeks; group 2A received 0.2 ml buserelin s.c. daily for 4 weeks; group 1B received 0.2 ml saline s.c. daily for 8 weeks; group 2B received 0.2 ml buserelin s.c. daily for 4 weeks followed by 0.2 ml saline s.c. daily for 4 weeks. Bone resorption was monitored by measuring urinary⁴⁵Ca and hydroxyproline. The rats in groups 1A and 2A were killed after 4 weeks and those in groups 1B and 2B after 8 weeks. The mineral contents of the femoral bones and the whole skeletons were measured. Buserelin lowered blood estradiol, elevated urinary⁴⁵Ca and urinary hydroxyproline, and lowered femur and total body calcium and⁴⁵Ca in group 2A vs. 1A (P<0.05). By contrast all these measurements became similar in groups 2B and 1B. Thus, osteopenia generated by a 4-week period of buserelin-mediated hypo-estrogenism is reversible by withdrawing buserelin for 4 weeks. Consequently, buserelin administration and withdrawal may be used to study effects of inducing and reversing estrogen-deficiency bone loss in the rat.     

The hepatic arterial blood flow response to portal vein occlusion in the dog

The acute effect of portal vein occlusion on hepatic arterial blood flow was studied in a group of nine anaesthetised dogs. The influence of hepatic artery denervation and total liver denervation on the hepatic arterial flow response was determined subsequently. Blood flows in the hepatic artery and portal vein were measured with electromagnetic flowmeters, and hepatic tissue perfusion with⁸⁵Krypton clearance. A side-to-side mesocaval shunt was constructed to provide a drainage channel for the mesenteric venous blood during the periods of portal vein occlusion.Occlusion of the portal vein produced an immediate and significant increase in hepatic arterial flow which was sustained at approximately 80% above control for the 6 min period of observation. Total liver blood flow and hepatic tissue perfusion were both significantly reduced by about 40%. Denervation either of the hepatic artery alone or the entire liver produced no change in the response, and it is concluded that there is no neurogenic component either initiating or modifying the early changes in hepatic arterial flow.     

Barriers and Facilitators to Effective Implementation of the NAMWEZA Intervention in Dar es Salaam,Tanzania

Prevention Science - The NAMWEZA intervention was implemented, using a ten-session group format, to build skills targeting psychosocial vulnerabilities and enhancing HIV prevention among people...