The influence of different levels of dietary fat on the incidence and growth of MNU-induced mammary carcinoma in rats

This study describes the influence of isocalorically fed diets (containing different amounts of fat) on tumor incidence and parameters of fat metabolism in female Sprague-Dawley rats. Comparisons are made between rats induced with methylnitrosourea (25 mg/kg body wt) and untreated controls (Group I). The animals received either control diets (3.9% fat by weight, Groups I and II) or fat-enriched diets (10.7%, Group III; 15.6%, Group IV; 21.4%, Group V) over a period of 180 days. At the termination of the experiment, intake of the diet containing 10.7% fat by weight (24% fat per total calories) was associated with the highest tumor incidence. Comparing the different diets, liver lipid concentrations in the individual groups increased with increasing dietary fat, whereas the total lipid in plasma decreased. During the feeding period, total lipid of the liver and plasma, and plasma cholesterol, increased in all groups, but triglycerides of plasma decreased. However, when plasma cholesterol and triglycerides were calculated as a relative amount of total lipid in plasma, cholesterol was found to be significantly decreased in Groups III and IV, and triglycerides were increased in Group III but decreased significantly in Groups I, II, and V at the end of the experiment.     

Update on the management of neuromuscular block: focus on sugammadex

Steroidal neuromuscular blocking agents (NMBAs), such as rocuronium, are widely used in clinical anesthesia and emergency medicine to facilitate endotracheal intubation and artificial ventilation and to allow surgical access to body cavities. Reversal of neuromuscular blockade is important for the acceleration of patient recovery and prevention of postoperative residual neuromuscular blockade and reduces the incidence of severe morbidity and mortality associated with anesthesia management. Sugammadex is the first selective relaxant binding agent (SRBA) and has been designed to reverse the steroidal neuromuscular blocking drug rocuronium. Encapsulation of the rocuronium molecule by sugammadex results in a rapid decrease in free rocuronium in the plasma and subsequently at the nicotinic receptor at the motor endplate. After encapsulation, rocuronium is not available to bind to the nicotinic receptor in the neuromuscular junction. This promotes the liberation of acetylcholine receptors, and muscle activity reappears. This new concept of reversal of neuromuscular block induced by rocuronium (or vecuronium) led to impressive results in animal and phase 1 and 2 studies. Sugammadex is currently in phase 3 clinical studies and may be commercially available by 2008.     

Aesthetic aspects in reconstructive microsurgery

The reconstruction of a part of the body that has lost or inhibited function has been the most important aspect of reconstructive surgery in the past. Because of the existence of better techniques and the patient's wish for social reintegration, the plastic surgeon today is forced to consider the aesthetic results of his work more than in the past. Sometimes microsurgical procedures in reconstructive surgery are the only chance for the patient to be healed or palliated. Experience with more than 350 free tissue transfers gave us the opportunity to estimate the value of a donor flap with respect to the requirements of the receiving site. To satisfy the high aesthetic demands in these cases, it was necessary for the right place and shape the flap to fit as closely as possible, even if further corrections were necessary to achieve a satisfactory result. The transfer of latissimus dorsi and radial forearm flaps to the face and lower leg is discussed in cases of tumorus diseases and severe injuries of young and old patients.Presented to the IXth Congress of the International Society of Aesthetic Plastic Surgery, New York, October 13, 1987     

Tropical spastic paraparesis-like illness occurring in a patient dually infected with HIV-1 and HTLV-II

We describe a 34-year-old man from southern Florida with a history of intravenous drug use, dually infected with human immunodeficiency virus type 1 (HIV-1) and human T-lymphotropic virus type II (HTLV-II), who developed a myelopathy clinically indistinguishable from HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). This myelopathy was characterized by spastic lower extremity weakness, distal paresthesias, sensory loss with a discrete thoracic level to pinprick, back pain, impotence, and sphincter disturbances. Nerve conduction studies revealed an associated mixed axonal and demyelinative neuropathy. Despite a lack of response to 10 months of zidovudine therapy, the myeloneuropathy improved dramatically 2 years after its onset in the absence of any therapeutic intervention.     

Effects of Intermittent Femoral Nerve Injections of Bupivacaine, Levobupivacaine, and Ropivacaine on Mitochondrial Energy Metabolism and Intracellular Calcium Homeostasis in Rat Psoas Muscle

Background: Long-acting local anesthetics cause muscle damage. Moreover, long-acting local anesthetics act as uncoupler of oxidative phosphorylation in isolated mitochondria and enhance sarcoplasmic reticulum Ca2+ release. The aim of the study was to evaluate effects of perineural injections of local anesthetics on mitochondrial energetic metabolism and intracellular calcium homeostasis in vivo.

Methods: Femoral nerve block catheters were inserted in adult male Wistar rats. Rats were randomized and received seven injections (1 ml/kg) of bupivacaine, levobupivacaine, ropivacaine, or isotonic saline at 8-h intervals. Rats were killed 8 h after the last injection. Psoas muscle was quickly dissected from next to the femoral nerve. Local anesthetic concentrations in muscle were determined. Oxidative capacity was measured in saponin-skinned fibers. Oxygen consumption rates were measured, and mitochondrial adenosine triphosphate synthesis rate was determined. Enzymatic activities of mitochondrial respiratory chain complexes were evaluated. Local calcium release events (calcium sparks) were analyzed as well as sarcoplasmic reticulum calcium content in saponin-skinned fibers.

Results: Eight hours after the last injection, psoas muscle concentration of local anesthetics was less than 0.3 [mu]g/g tissue. Adenosine triphosphate synthesis and adenosine triphosphate-to-oxygen ratio were significantly decreased in the muscle of rats treated with local anesthetics. A global decrease (around 50%) in all of the enzyme activities of the respiratory chain was observed. Levobupivacaine increased the amplitude and frequency of the calcium sparks, whereas lower sarcoplasmic reticulum calcium content was shown.     

Retrospective patient outcome evaluation after semi-rigid stabilization without fusion for degenerative lumbar instability

Postero-lateral fusion by means of rod-and-screws/hooks constructs is still the gold standard in the treatment of lumbar degenerative spinal diseases. However, fusion remains fraught with a high risk of adjacent levels degeneration, sometimes leading to suboptimal clinical outcomes. Dynamic stabilization is supposed to compensate for disadvantages associated with rigid fusion. Preliminary results of spinal stabilization by means of dynamic devices show encouraging results. Therefore, the aim of the present study is to retrospectively evaluate the overall long term outcome and the condition of the adjacent discs to fused segments in an active population of 33 patients with back pain associated with lumbar instability, who underwent postero-lateral dynamic stabilization by means of a dynamic rod-and-screws construct, without fusion. The mean follow-up was 45 months. Clinical and radiological data, pain, function, return to work rate and patient satisfaction index were recorded to assess the overall patient outcome. The results show a very low rate of post-operative complications. No spontaneous fusion was noted in any patient. Pain, both lumbar and radicular, was totally relieved in most of the patients and the functional results were good or excellent in 76% of patients. Most of the patients resumed their previous activities; the return to previous work rate was 87.5%. Ninety-four percent of the patients were fully satisfied with the results. The preservation of both instrumented levels and the adjacent ones was observed in 90% of patients. Although the present series is rather limited in number, the results of the study are encouraging and in agreement with most findings in the literature. As the results are sustained at a mid and long term, the authors believe that the stabilization without fusion by means of semi-rigid/dynamic systems is an interesting alternative to classical fusion as long as the indications are strictly defined.     

Generation of cell diversity and segmental pattern in the embryonic central nervous system of Drosophila.

Development of the central nervous system (CNS) involves the transformation of a two-dimensional epithelial sheet of uniform ectodermal cells, the neuroectoderm, into a highly complex three-dimensional structure consisting of a huge variety of different neural cell types. Characteristic numbers of each cell type become arranged in reproducible spatial patterns, which is a prerequisite for the establishment of specific functional contacts. The fruitfly Drosophila is a suitable model to approach the mechanisms controlling the generation of cell diversity and pattern in the developing CNS, as it allows linking of gene function to individually identifiable cells. This review addresses aspects of the formation and specification of neural stem cells (neuroblasts) in Drosophila in the light of recent studies on their segmental diversification.