The influence of age on neurotransmitter turnover in the rat's superior colliculus.

Measurements of the turnover of dopamine, noradrenaline and serotonin and their metabolites have been performed in the superior colliculus of adult and aged rats. The turnover of dopamine, noradrenaline and their metabolites after pargyline treatment was significantly lower in aged rats than in adults. On the contrary, the synthesis rate of serotonin (measured by accumulation of 5-hydroxytryptophan after decarboxylase blockade) and the turnover rate of serotonin (after pargyline treatment) did not change during aging. These findings suggest that aging has a different effect on catecholamines and serotonin turnover in the superior colliculus of the aged rats.     

Electron microscopy renders the diagnostic capabilities of cytopathology more precise: an approach to everyday practice

Cytology is a powerful diagnostic tool but to make definitive diagnoses, the use of ancillary techniques is imperative. By combining immunohistochemistry (IHC) and electron microscopy (EM), cytologic diagnoses can be as precise as those of surgical pathology. In the authors' daily practice of cytopathology they use all ancillary techniques available to them: histochemistry, IHC, EM, flow cytometry, and molecular pathology. IHC is frequently used as an ancillary technique in their daily practice but EM is many times their technique of choice. By the use of EM the authors can make specific final diagnoses, make the diagnosis more definitive, narrow the differential diagnosis, or determine the origin of a neoplasm with unknown primary site. Specimens obtained by fine-needle aspiration as well as all body fluids are suitable for EM. The limiting factor is to obtain the appropriate material with the diagnostic cells for ultrastructural examination. The common diagnostic dilemmas in the everyday practice of cytology are the following: mesothelioma vs. adenocarcinoma, neuroendocrine differentiation or not, the distinction of melanoma from adenocarcinoma and sarcoma, hepatocellular carcinoma vs. adenocarcinoma, and the origin of adenocarcinomas of unknown primary. The authors discuss how they approach these diagnostic problems in their everyday practice and how they incorporate EM in solving them.     

Role of laparoscopy with ultrasound in the staging process of pancreatic and ampullary tumors

Computarized tomography allows proper identification and evaluation of stage in the majority patients with periampullary tumors. However, 30% of peritoneal metastases cannot be seen in image studies. The aim of the present study was to evaluate the role of laparoscopy with laparoscopic ultrasound in the staging process of pancreatic and ampullary tumor. Diagnostic laparoscopy was performed on 20 patients included in the study Mean age was 58.35 +/- 13.4 years. Twelve were males and eight females. In two patients, laparoscopy showed peritoneal metastases and ultrasound did not show extrapancreatic involvement. In five patients, there was vascular invasion without metastases. In three patients, both peritoneal metastases and vascular invasion were found, and in five there was neither vascular invasion nor metastasis. Laparoscopic findings were confirmed in a but one patient. In 14 of the 16 patients In whom peritoneal lavage was performed, microscopic exam showed a sufficient number of cells to make a diagnosis. We concluded that laparoscopy with ultrasound is useful in staging of patients with duodeno-bilio-pancreatic malignancies.     

Impacto del nivel socioeconómico sobre el perfil del paciente amputado de miembro inferior por causa no traumática

IntroductionTo analyse the influence of socioeconomic status on the clinical profile of patients undergoing non-traumatic lower-limb amputation.MethodsRetrospective study of 697 lower-limb amputee patients in an Angiology and Vascular Surgery Department during a 5-year period. Patients were classified according to their socioeconomic status (low, medium and high). We analysed demographic (age and gender) and clinical variables (cause of amputation, comorbidity, cardiovascular risk factors and amputation level).ResultsMean age was 70.5 ± 11.9 years, and the median was 72 years. The low socioeconomic status group presented a higher frequency of amputations in men. Cardiovascular risks factors were more frequent in this socioeconomic group, and the difference was statistically significant for diabetes (85.8% low, 69.3% medium, 65% high; P<.01) and obesity (31.4% low, 22.6% medium, 12.5% high, P<.01). Diabetic retinopathy was the only comorbidity with a significant association with low socioeconomic status (21.1% low, 15.3% medium, 12.5% high, P<.03). Regarding the cause for amputation, there was no difference in terms of socioeconomic status. The low socioeconomic level showed a higher frequency of major amputation, which was a significant difference (63.6% low, 41.2% medium, 55% high, P<.04) and a higher predisposition for this amputation level.ConclusionsThe low socioeconomic status has been shown to determine an unfavourable vascular risk profile in lower-limb non-traumatic amputees and a higher predisposition of a major amputation. This socioeconomic level demonstrates a negative influence on these patients’ diabetes, obesity and diabetic retinopathy.     

The use and effects of vital fluorescent dyes: observation of motor nerve terminals and satellite cells in living frog muscles

Summary Several different fluorescent mitochondrial dyes were tested as vital stains for motor nerve terminals and other cells in frog skeletal muscles. It was found that 3,3diethyloxadicarbocyanine iodide and 4-(4-diethylaminostyryl)-N-methylpyridinium iodide were most useful. Both dyes labelled motor nerve terminals with high reliability. Electrophysiological and morphological control experiments showed that these dyes could be used to repeatedly observe neuromuscular junctions in living animals without affecting synaptic growth or remodelling. The importance of appropriate controls was emphasized by the finding that illumination, if excessively intense or prolonged, can cause physiological and structural damage to nerve terminals. Additional observations indicated that these dyes may be useful for determining the mitochondrial content, and therefore oxidative capacity, of living muscle fibres. It was also found that the fluorescent dyes labelled cells identified as muscle satellite cells, and that these myoblast precursors could be visualized in fixed whole mounts with a nitroblue tetrazolium stain. Both methods were used to study reactive cells that were closely associated with muscle fibres in lesioned muscles. Mitochondrial dyes also labelled the microvasculature, associated axons and other cells.     

The prevalence of serological markers for the human immunodeficiency virus and the hepatitis B virus in a psychiatric hospital

OBJECTIVES: To estimate the prevalence of antibodies to human immunodeficiency virus (HIV), antibodies to hepatitis B core antigen (anti-HBc), hepatitis B surface antigen (HBsAg), and antibodies to delta virus (anti-DV). DESIGN: Cross-sectional (prevalence) study. A non-proportional (stratified by length of stay) random sample of 20% of admitted patients was selected. CLINICAL SETTING: The Hospital Psiquiátrico Nuestra Se?ora de Montserrat (Sant Boi de Llobregat, Barcelona, Spain) admits about 670 patients in its short-term, rehabilitation (mid-term) and long-term wards. SUBJECTS: 139 patients were selected: 91% were males, mean age was 55 years, and 10% belonged to an HIV risk group; mean length of hospitalization since last discharge was 13 years. MEASUREMENTS: Blood samples were drawn in October, 1988. Anti-HBc, HBsAg and anti-DV were determined by competitive enzyme immunoassay (EIA). Anti-HIV-1 were determined by sandwich EIA; negativity of results with high absorbency but below the cut-off point was confirmed by Western blot. RESULTS: None of the sampled patients had circulating anti-HIV-1 antibodies. Four cases showing high absorbency (below the "cut-off" point) were ruled out by Western-blot. Overall, the prevalence of anti-HBc was 52.8% (54.4% in long-term wards, 35.0% in mid-term wards, and 13.8% in short-term wards). The prevalence of HBsAg was 2.3%, of anti-DV 1.5%, and of HDAg 0%. CONCLUSIONS: Prevalence of anti-HIV is null in the studied institution. Current efforts to prevent HIV infection must continue; a hepatitis B vaccination program is highly warranted among patients and professionals of the studied hospital.     

Utilisation of organs proceeding from donors with heart failure: review of the pathogenesis of organic damage and the possible mechanisms of prevention

There is an evident imbalance between the number of patients awaiting a kidney transplant and the availability of organs proceeding from donors with brain death. A high number of patients die each day from heart failure, whose organs could be used for transplants if specific care is employed. Although centres do exist where these methods of extraction are established, the problems of organic damage have yet to be resolved, since one third of the organs are still lost, besides the increase in the need for early dialysis, and the number of dysfunctioning grafts two years after the transplant, when this type or organ is employed. There is increasingly detailed knowledge of the pathogenesis of organic damage following heart failure and reanimation, as well as of the damage following the conservation and reimplantation of the kidney. Knowledge of the maximum time of hot ischemic that an organ can withstand is of crucial importance if organs are not to be unduly discarded. Besides, the increasing understanding of the physiopathology of oxidative stress could make it possible for us, through the use of antioxidants, to attempt to improve the utilisation of the organs and diminish the incidence of dysfunctions and rejections.     

Autoradiographic localization of dopamine D2-like receptors in the rabbit pulmonary vascular tree

In the present study, the pharmacological characteristics and the anatomical localization of dopamine D₂-like receptor sites in the extraparenchymal and in the intraparenchymal portion of the rabbit pulmonary artery were investigated using combined radioligand binding and light microscope autoradiography with [³H]-spiroperidol (spiperone) as a ligand. The ligand was bound to sections of the pulmonary artery in a manner consistent with the labelling of dopamine D₂-like receptors with an equilibrium dissociation constant (K _d) of about 2.4±0.07 nmol/l and a maximum density of binding sites of 65±4.5 fmol/mg tissue. In contrast, binding experiments made with sections of rabbit lung did not allow the evaluation of specific binding. Light microscope autoradiography showed the development of specific silver grains within the tunica adventitia of extraparenchymal branches of rabbit pulmonary artery and of large and, to a lesser extent, of medium-sized intraparenchymal branches of the pulmonary artery. No silver grains were found within small branches of the pulmonary artery or of the pulmonary vein. Development of adventitial silver grains was inhibited by compounds active at dopamine receptors. The greater sensitivity to displacement by domperidone, haloperidol, (–)-sulpiride and bromocriptine than to displacement byN-propyl-norapomorphine, quinpirole or clozapine suggests that the [³H]-spiroperidol binding sites observed in extraparenchymal, large and medium-sized branches of the pulmonary artery belong, probably, to the dopamine D₂ receptor subtype. The possible pre-junctional localization of these sites is discussed. Correspondence to: R Amenta     

‘Hybrid’ Bariatric Surgery: Bilio-pancreatic Diversion and Duodenal Switch - Preliminary Experience

Background: Hybrid, combined or mixed bariatric surgery is the combination of a degree of ‘malabsorption’ (as achieved by the intestinal bypass) with a ‘rrestriction’ (as achieved by gastric bypass or gastroplasty), thereby simultaneously reducing the absorption of fats in the small bowel and decreasing the intake of food. Methods: A modification of the bilio-pancreatic diversion (BPD) with a duodenal switch procedure, vertical lineal gastrectomy and preservation of the pylorus, has been used in 23 patients. The antropyloric pump and 4 cm of the duodenum are left intact to preserve physiologic gastric emptying and to prevent anastomotic ulcer. The use of staplers and continuous running sutures reduces surgical risks and operative time. Results: One patient, converted from a vertical gastroplasty, had an intrathoracic esophageal perforation and died of multisystemic organ failure, a mortality rate of 4.5%. One patient had a partial dehiscence of the laparotomy wound. Three patients developed subcutaneous seromas. Mean weight losses during the first 4 months were 13, 11, 6 and 5 kg, with a loss of 70% of excess weight in patients approaching 1 year. No patient needs treatment for diarrhea. No serious secondary side-effects have been detected. Conclusion: This operation appears to result in very satisfactory weight loss, improved quality of life, and a low incidence of complications.