Evidence for the existence of different receptor sites for algesic agents at the endings of muscular group IV afferent units

Summary The hypothesis that different receptor sites for algesic agents exist at free nerve endings in skeletal muscle has been tested by administering bradykinin and 5-hydroxytryptamine (5-HT) repeatedly in anaesthetized cats and evaluating the response behaviour of single group IV afferent units from the gastrocnemius-soleus muscle.Repeated intraarterial administration of bradykinin at intervals of 1 and 2 min usually elicited fibre responses without tachyphylaxis. Injections of equieffective doses of 5-HT, however, given in the same manner evoked fibre reactions that were strongly tachyphylactic. In units responding to both bradykinin and 5-HT a refractoriness to 5-HT could be induced by repeated injections of this agent without impairing the stimulating potency of bradykinin on the same nerve ending. Such a lack of cross-tachyphylaxis seems to apply also to the effects of histamine on one side and bradykinin or 5-HT on the other.These findings suggest that bradykinin, 5-HT and probably histamine exert their excitatory action on muscular group IV afferent units via different receptor sites.     

Corpora amylacea in mesothelioma of the atrioventricular node.

Rounded or polyhedral, acellular, dense lamellated structures were seen within gland-like spaces in a case of atrioventricular mesothelioma. These structures exhibited many of the histochemical characteristics of amyloid, viz., pink colour with green birefringence and bright red fluorescence with alkaline Congo red; ortochromasia and red birefringence with standardised toluidine blue; positive DMAB-nitrite and diazotisation coupling reactions and spontaneous autofluorescence. It is suggested that these bodies are derived from spontaneous assembly or polymerisation of microfibrils of desquamated cells lining the cystic spaces of the tumour as occurs in prostatic corpora amylacea. The peculiar intramyofibre proliferation of tumour cells in the peripheral part of the tumour suggests that viable tumour cells can penetrate, survive and proliferate within atrial or nodal myofibres leaving an intact sarcolemmal sheath. The slow tumour cell growth and the successive degeneration of central tumour cells may explain the tubular and/or glandular pattern constantly seen in this tumour.     

A morphological,biochemical, and radioautographic study in rats

Splenectomy has long been an establishmd surgical procedure in various conditions, including trauma. Because total splenectomy has often been correlated with sepsis, every surgeon tries to preserve as much of the injured spleen as possible. Contradictory reports have been published as to whether regeneration of the remaining splenic tissue is possible. In the present study, 28 Sprague-Dawley rats ( 100 g) were divided into four groups. They underwent two-thirds partial splenectomy; the remaining splenic tissue was examined after 1 day, 1 week, 1 month and 3 months postoperatively. The following parameters were determined: weight, length, and protein and deoxyribonucleic acid (DNA) content of the remaining spleen. The incorporation of ³H-thymidine into the remaining spleen tissue was also measured. Histology and radioautography were studied in parallel. Results were compared with control animals that were operated upon but with no partial splenectomy. One day, 1 week, and 1 month following partial splenectomy, a slight increase in weight, length, protein, and DNA content as well as incorporation of the radioisotope into cellular DNA was found. By 3 months after the operation, there was no difference in the above parameters between the experimental animals and controls.Radioautographs indicated that most of the cells containing the isotope were situated in the perinodular areas in the red pulp, accompanied by an increased number of inflammatory cells. We found this cell proliferation mainly along the cut surface of the spleen. The slight increase that was found in all the parameters examined up to 1 month after partial splenectomy is an inflammatory response and not regeneration of the spleen.     

Development and validation of the Diabetes Care Profile

To determine the reliability and the validity of the Diabetes Care Profile (DCP), an instrument that assesses the social and psychological factors related to diabetes and its treatment, two studies with separate populations and methodologies were conducted. In the first study, the DCP was administered to, and physiologic measures collected from, individuals with diabetes being cared for in a community setting (n = 440). In the second study, the DCP and several previously validated scales were administered to individuals with diabetes receiving care at a university medical center (n = 352). Cronbach's alphas of individual DCP scales ranged from .60 to .95 (Study 1) and from .66 to .94 (Study 2). Glycohemoglobin levels correlated with three DCP scales (Study 1). Several DCP scales discriminated among patients with different levels of disease severity. The results of the studies indicate that the DCP is a reliable and valid instrument for measuring the psychosocial factors related to diabetes and its treatment.     

Aortic dissection in a young woman with Turner's syndrome

Aortic dissection is an extremely rare occurrence often associated with fatal consequences. Among women suffering from Turner's syndrome, a mosaic of cardiovascular anomalies, some congenital, are often reported. Among these abnormalities, the conjunction of dilatation of the aorta with hypertension may lead to aortic dissection. A high level of clinical follow-up is necessary on a lifetime basis in order to diagnose such patients on time, which will allow preventive surgical intervention. Successive echocardiographic surveillance of these patients is recommended in addition to aggressive antihypertensive therapy in order to minimize potential morbidity and mortality as much as possible. If aortic dissection is diagnosed on time, surgical intervention can be lifesaving. In this communication, we report on a patient whose diagnosis was missed and consequently expired due to severe aortic dissection.     

Resection of brain lesions with a neuroendoscopic ultrasonic aspirator — a systematic literature review

Neurosurgical Review - The development of minimally invasive neuroendoscopy has advanced in recent years. The introduction of the neuroendoscopic ultrasonic aspirator (NUA) increased the treatment...     

Minimally invasive surgery for axillary dissection

Axillary dissection is the major cause of morbidity in breast cancer and primary cutaneous melanoma of the extremity. In the present study, we examine the potential benefits and advantages of endoscopic axillary lymph node dissection over conventional surgery. Twenty endoscopic axillary dissections and 10 lymph node samplings were performed in 10 cadavers (four male, six female). A preperitoneal distention balloon (PDB) system was used to dissect the axilla. In four of the cadavers, the procedure was followed by open surgery. The axillary contents were examined for lymphatic tissue by a pathologist. The endoscopic technique offered easy access to the axilla and clear visualization of the axillary vein, as well as the long thoracic and thoracodorsal nerves. Results were comparable to those achieved with the classic surgical dissection. Endoscopy is feasible for axillary lymph node dissection and sampling in cases of breast cancer and primary cutaneous melanoma of the extremity. Further studies in patients are needed to reach definitive conclusions. Received: 31 December 1996/Accepted: 12 September 1997     

The alpha-defensins stimulate proteoglycan-dependent catabolism of low-density lipoprotein by vascular cells: a new class of inflammatory apolipoprotein and a possible contributor to atherogenesis

Inflammation may contribute to the pathogenesis of atherosclerosis. On the basis of previous reports that human atherosclerotic lesions contain alpha-defensins, a class of cationic proteins released by activated neutrophils, the study was designed to ask whether defensins modulate the binding and catabolism of low-density lipoprotein (LDL) by human vascular cells. The results of the study demonstrated that defensin stimulated the binding of (125)I-LDL to cultured human umbilical vein endothelial cells, smooth muscle cells, and fibroblasts approximately 5-fold in a dose-dependent and saturable manner. Defensin and LDL formed stable complexes in solution and on cell surfaces. Stimulation of LDL binding by defensin was not inhibited by antibodies against the LDL-receptor (LDL-R), or by recombinant receptor-associated protein, which blocks binding of ligands to the alpha(2)-macroglobulin receptor/LDL-R-related protein and other LDL-R family members. Furthermore, defensin stimulated the binding, endocytosis, and degradation of LDL by fibroblasts lacking LDL-R. Stimulation of LDL degradation by defensin was inhibited approximately 75% by low concentrations of heparin (0.2 units/mL) and was similarly reduced in CHO cells lacking heparan-sulfate-containing proteoglycans. The effect of defensin was substantially increased in cells overexpressing the core protein of the syndecan-1 heparan sulfate proteoglycan. The alpha-defensins released from activated neutrophils may provide a link between inflammation and atherosclerosis by changing the pattern of LDL catabolism from LDL-R to the less efficient LDL-R-independent, proteoglycan-dependent pathway. (Blood. 2000;96:1393-1398)     

Suicide in Israel: 1985-1997

OBJECTIVE: To examine trends in suicide rates in Israel over a 13-year period. METHOD: All cases of autopsy-confirmed suicide in Israel from 1985 to 1997 were retrospectively reviewed. RESULTS: An overall annual increase in suicide rates, with rates in men 3 times higher than those in women, was observed. Suicide rates were highest in the second and third decades of life. Unlike Western countries where gunshot wounds are the most common method of suicide for men and poisoning is most common for women, asphyxiation by hanging was the most common method used by men in Israel, followed by firearm wounds and jumping from heights. In women, however, jumping from heights was the most common method, followed by hanging and poisoning. CONCLUSION: Increasing rates of suicide may be associated with waves of immigration to Israel, increased substance abuse and depression and the political and social climate. Further study to examine the precipitating factors is warranted.