The role of platelet activating factor (PAF) in physiology and pathology of the central nervous system

This review describes the role of platelet activating factor (PAF) in the central nervous system injury. Cerebral ischaemia, traumatic injury of central nervous system, metabolic, toxic and degenerative neuropathy, and also the increase in Ca2+ concentration in the cell, are strong stimulators of PAF synthesis and its release from cell membranes. Neurons, glial and microglial cells, monocyte cell populations, macrophages and endothelial cells of blood vessels are the targets of platelet activating factor. The release of PAF leads to ischaemia of nervous tissue, acute traumatic or nontraumatic injuries, degenerative and metabolic nervous system disorders in adults. The use of PAF receptor antagonists prevents partially cell injury in central nervous system and leukocyte adhesion to endothelial cells.     

Biomechanical evaluation of braces used for the treatment of epicondylitis

The purpose of the study was to investigate the biomechanical effects of different types of braces that are used in the treatment of patients with epicondylitis radialis. Vibration and acceleration of the forearm and the elbow were measured with sensors taped to defined anatomic points on the skin surface. The impact-induced vibration of the racket-arm system was analyzed while the subjects were playing tennis. Different designed brace systems were investigated with respect to acceleration amplitudes and acceleration integrals. Clasp-based brace systems showed a slight reduction of acceleration amplitudes (-6%) and acceleration integrals (-8%). Braces with pads at the lateral epicondyle reduced acceleration amplitudes by 20% and acceleration integrals by 22%. Braces with pads placed at the forearm showed the highest reduction of acceleration amplitudes (-46%) and acceleration integrals (-42%). Overload of the wrist extensors, which is considered to be a major pathogenic factor in lateral epicondylitis, can be reduced by braces. There is a significant difference in the effects among different biomechanical principles of braces.     

The relationship between features of metabolic syndrome and blood adipocytokine concentrations in the morbid obese patients during dynamic weight loss

Bariatric surgery is the most effective method to achieve weight loss in obese subjects. The aim of this study was to evaluate some adipocytokines and insulin, as well as parameters of metabolic syndrome of the obese patients, for three and six months after vertical banded gastroplasty, in the time of dynamic weight loss. Seven males and two females aged 28 to 49 years, with long lasting simple obesity and the presence of metabolic syndrome, were studied. After surgical treatment the values of the body mass index, waist circumference, systolic and diastolic blood pressure, total cholesterol, LDL cholesterol, triglycerides, and blood concentrations of leptin decreased significantly. Before surgical operation of all obese patients no statistically significant correlations between studied parameters were noted. Three and six months later a lot of correlations between studied parameters appeared. In conclusion, (a) vertical-banded gastroplasty is a valuable method in treatment of obese subjects, leading to a significant decrease in body weight and improvement in some parameters of metabolic syndrome in a few months after surgery, (b) adipocytokines, together with an unknown gastric factor, may be key factors in the control of some features of the metabolic syndrome.     

Captopril-associated cholestasis complicating the management of pancreatic cancer

Cholestatic jaundice is a rare complication associated with the use of the angiotensin -converting enzyme inhibitor captopril. The severity of the disease may range from cholestasis on liver histology to overt fulminant hepatic failure. This diagnosis is seldom considered in patients with pancreatic or biliary tract malignancy. We present a patient with unresectable adenocarcinoma of the pancreas whose jaundice decreased slowly over many weeks despite establishment of adequate endoscopic biliary drainage. The presence of captopril-associated cholestasis confounded confirmation of adequate biliary drainage. The absence of observed hepatic bile secretion at duodenoscopy, as seen in this patient, is a previously unreported endoscopic feature of this syndrome.     

Endoscopic hernia repair]

A laparoscopic procedure for surgical hernia repair is reported. In comparison to other methods we do not only remove the peritoneal sac, but close although the inguinal canal with a nonresorbable marlex mesh. Up to now we practiced this technique in 35 patients. First post-operative results are encouraging but nothing can be said about longterm results, especially the recurrence rate.     

A relationship between repression of dimethylnitrosamine-demethylase by polycyclic aromatic hydrocarbons and their shape

The quantitative relationship between the ability of polycyclic aromatic hydrocarbons to repress the mixed-function oxidase, dimethylnitrosamine-demethylase, and a parameter expressing the shape of the hydrocarbon molecules, has been studied. The shape parameter represents the ratio of the longer to shorter sides of the minimum rectangular envelope around the structure, drawn proportionally to atomic dimensions. The shape parameter allows the prediction of the relative biological activity of 23 active and 4 inactive compounds.     

The fate of synaptic membranes of degenerating optic nerve terminals, and their role in the mechanism of trans-synaptic changes

Summary The fate of synaptic membranes of degenerating optic nerve terminals has been studied in the lateral geniculate nucleus of Rhesus monkey after eye enucleation. It was shown that pre-synaptic and post-synaptic membranes remain in close apposition to each other during all stages of degeneration and phagocytosis of affected terminals. As a result of this, fragments of presynaptic terminals were engulfed within glial processes, together with synaptic thickenings and parts of post-synaptic dendrites. On occasion small pieces of the degenerating terminals together with the synaptic membranes were engulfed by the post-synaptic dendrite. It is proposed that this pattern of removal of degenerating optic terminals results in injury to the post-synaptic cells, and triggers the transneuronal degeneration.     

Serotonin-related enhancement of recovery of hind limb motor functions in spinal rats after grafting of embryonic raphe nuclei

Recently, we demonstrated improvements in hind limb locomotor-like movements following grafting of embryonic raphe nuclei cells into the spinal cord below the level of total transection in adult rats. The purpose of the present study was to clarify whether this improvement was due to newly established serotonergic innervation between the graft and the host. Two months after intraspinal grafting of the embryonic raphe nuclei, the spinalized rats, when put on a treadmill, could be induced to walk with regular alternating hind limb movements with the plantar contact with the ground during the stance phase, and ankle dorsiflexion during the swing phase of each step cycle. In the same situation the spinal rats, that did not receive the graft, were not able to initiate the dorsiflexion of the ankle joint during the swing phase and very often the dorsal surface of the foot was dragged along the ground. Intraperitoneal application of directly acting 5-HT2 antagonist Cyproheptadine (1 mg/kg) impaired reversibly the hind limb locomotor-like movements in grafted rats. This impairment lasted for 2-3 h. The same procedure in control rats did not markedly alter the hind limb locomotor-like movements. The effect of Cyproheptadine in grafted rats was reversed by i.p. injections of the 5-HT2 agonist Quipazine (0.5 mg/kg). These results show that the graft-induced restitution of hind limb locomotor abilities in adult spinal rats is brought about by the new serotonergic innervation of the host spinal cord circuitry from the grafted neurons and is mediated by 5-HT2 receptors.