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OBJECTIVES: To evaluate the impact of implementation of guidelines aimed at reducing the use of laboratory and diagnostic preoperative tests in patients with low anesthesiologic risk, admitted to six public hospital of Ente Ospedaliero Cantonale in Cantone Ticino (Switzerland). DESIGN: Observational study. METHODS: Time series analysis of patterns of use of preoperative tests, on 14,585 patients admitted to public hospitals form March 1996 to June 1998. PRINCIPAL OUTCOME MEASURE: Proportion of patients undergoing a laboratory or other diagnostic tests during three six months periods before guidelines implementation (baseline), during the six months of the implementation phase and during the following four months of adoption of the guidelines in the participating centres. RESULTS: During the four months following the implementation, we observed a reduction of 15% (95% CI: 1%-27%) in the use of azotemia, and a reduction of 34% (95% CI: 18%-50%) for coagulation tests. Corresponding figures for glycemia and chest x-ray indicated a reduction of 44% (95% CI: 32%-54%) and of 22% (95% CI: 8%-34%), respectively. As for other tests (creatinine, ECG), no statistically significant reduction was observed. Most of the observed effect was explained by a reduction in use in patients at a low risk (ASA 1 and 2). In addition, guidelines appeared to have a greater impact in the four small (i.e. < 200 beds) hospitals, as compared with the two centres of greater size. CONCLUSIONS: Consistently with the empirical evidence available in this area, this study suggests that guidelines can change clinical practice, when they are implemented through a strategy taking into account adaptation of the recommendations to local circumstances and involvement of health professionals.

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We have studied the effects of hypocapnia on cerebrovascular changes in two MAC-equivalent anaesthetic regimens, using the transcranial Doppler technique as an index of cerebral blood flow (CBF) in 24 healthy ASA I patients undergoing spinal surgery. Eight of the patients were subjected to carbon dioxide reactivity challenges in the awake state. Before surgery, the other 16 patients received, in random order, either 1.15% isoflurane in oxygen or 0.5% isoflurane with 70% nitrous oxide. Carbon dioxide reactivity was calculated for each group as the increase in flow velocity per kPa change in PE'CO2 (cm s-1 kPa-1). It was significantly greater for the isoflurane group (14.09 (SD 2.44) cm s-1 kPa-1) and significantly less for the isoflurane-nitrous oxide group (7.95 (1.32) cm s-1 kPa-1) compared with the awake group (11.24 (0.95) cm s-1 kPa-1). We conclude that cerebrovascular responsiveness to changes in arterial carbon dioxide concentration is influenced markedly by the anaesthetic procedure. Hyperventilation is more likely to affect CBF during isoflurane anaesthesia than during an MAC-equivalent isoflurane-nitrous oxide anaesthesia.

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The distribution of protein 7B2, a protein with structural characteristics of GTP-binding proteins, has been studied in normal pancreatic islets and in a series of 70 pancreatic endocrine tumours with emphasis on the co-localization of 7B2 and the different pancreatic hormones. Although all cell types of normal islets were found to store 7B2, variations from intense expression to absence of reaction were seen within each cell type. In particular, B cells showed intense immunostaining for 7B2 in small compact islets and weak or no staining in larger islets with lobular arrangement. Pancreatic polypeptide (PP) cells expressed 7B2 intensely in the PP-rich area of ventral embryological origin, but were mostly non-reactive in the PP-poor area. The A cells, located along intralobular blood vessels, were more frequently immunoreactive for 7B2 than those at the periphery of the islets. Immuno-electron microscopy revealed a preferential localization of 7B2 in secretory granules of islet cells, with more intense localization in the peripheral halo of alpha granules. Benign islet cell tumours more frequently expressed 7B2 than their malignant counterparts. Although often expressed in a lower number of tumour cells than the tumour-specific hormone, 7B2 was usually co-localized with the latter. In contrast, no relationship was found with the localization of proinsulin. It is concluded that 7B2 is a non-permanent component of the cell granule compartment, probably involved in events related to exocytosis and without relationship to intracellular prohormone processing.

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A histologic and immunohistochemical study was carried out in 23 unselected nonantral gastric carcinoids and their precursor lesions classified according to Solcia et al. None of the patients showed Zollinger-Ellison syndrome. Two variants of carcinoids showing distinctive pathologic and pathogenetic characteristics were identified on the basis of presence or absence of associated chronic atrophic gastritis type A (A-CAG). Chronic atrophic gastritis type A was found in 19 cases showing either single or multiple neoplasms, tumor extension limited to the mucosa or submucosa, consistent endocrine cell precursor changes in extratumoral mucosa, and consistent hypergastrinemia and/or G cell hyperplasia. Associated precursor lesions were only hyperplastic in all but two cases with single carcinoids whereas they were also dysplastic in all but one case with multiple carcinoids. The four tumors arising in nonatrophic mucosa were all single, more aggressive, and not associated with extratumoral endocrine cell proliferations or with signs of gastrin hypersecretion. Tumor cells were diffusely immunoreactive for chromogranin A and synaptophysin but usually negative for chromogranin B or HISL-19. Scattered serotonin cells were found in ten carcinoids. They were more frequent in infiltrating than in intramucosal tumors as were the less represented pancreatic polypeptide cells whereas the reverse was found for alpha-subunit-containing cells. These results are of relevance for tumor pathogenesis and may provide the rationale for a less aggressive therapeutic approach in the patients.

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A case of mandibular leiomyoma in a 8-month-old baby is reported. This is the 5th case of intrabony leiomyoma of the jaws reported so far. The tumor presented as a symptomless swelling of the mandibular ramus and required a limited resection. The pertinent literature is reviewed and the histological features discussed.

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The endocrine cells of the oxyntic mucosa of five patients with longstanding Zollinger-Ellison syndrome were quantitatively investigated with electron microscopy and two light microscopic methods (Grimelius and immunostaining for chromogranin A). Ultrastructurally, the volume density of endocrine cells was 3.2% +/- 1.1% of the mucosal epithelial component, a 168% increase (P less than 0.001) over the value found in normal subjects. Of the six endocrine cell types of human oxyntic mucosa, only enterochromaffinlike cells increased in cell density (65% +/- 15% of the total endocrine cell mass), size, and number of cell profiles per unit area. The enterochromaffinlike cells also underwent morphological changes of secretory granules with a decrease in vacuolated forms, increase in elongated profiles, and appearance of granules with a punctate structure of the core. The latter variety of granules was previously observed only in carcinoid tumors of the oxyntic mucosa and is possibly related to the enterochromaffinlike cell hyperplasia-neoplasia sequence seen in hypergastrinemic patients. A positive relationship was found between endocrine cell densities evaluated ultrastructurally and with chromogranin A immunostaining. It is concluded that in Zollinger-Ellison syndrome, the trophic effects induced by longstanding hypergastrinemia are strictly selective for enterochromaffinlike cells and are associated with ultrastructural features typical for enterochromaffinlike cell tumors.

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Expression of the alpha-subunit of glycoprotein hormones is an acquired feature of the endocrine cells of the oxyntic mucosa in patients with sustained serum levels of gastrin, and may be related to the hyperplasia-carcinoid sequence occurring in these patients. In the present study we have investigated the intragastric cellular localization and the circulating levels of alpha-subunit in a patient with Zollinger-Ellison syndrome. In this patient we have found that: 1) Endocrine cells accounted for 2.29% +/- 1.44% of the total oxyntic mucosal volume (normal value: 0.9% +/- 0.4%), with the ECL cells representing 63.22% +/- 10.9% of the total endocrine cell volume (normal value: 29.8 +/- 8.8%). 2) Cells immunoreactive for the alpha-subunit were found to correspond ultrastructurally to a subpopulation of enterochromaffin-like cells, indistinguishable from similar cells devoid of significant immuno-electron microscopic labeling. 3) Immunoreactive cells included a portion of oxyntic endocrine cells with punctate granules, a feature previously observed only in carcinoid tumors of the oxyntic mucosa. 4) In consecutive sections of freeze-dried vapor-fixed biopsies a fraction of alpha-subunit storing cells was found to co-express histamine. 5) The serum alpha-subunit levels were abnormally elevated and paralleled those of gastrin in a secretin-stimulation test. Analysis of similar curves in two other patients with Zollinger-Ellison syndrome, and five patients with hypergastrinemic atrophic gastritis, all presenting alpha-subunit containing oxyntic endocrine cells, showed significant alpha-subunit elevations only in the patients with ulcerogenic syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

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A case of multiple gastric carcinoids and nonantral atrophic gastritis in which the larger tumor was a composite carcinoid-adenocarcinoma is presented. The two components of the composite tumor immunohistochemically showed clear-cut diverging functional differentiations although the available evidence supported a common histogenesis from the metaplastic intestinal epithelium of the gastric mucosa. The carcinoid tissue of the composite tumor, which showed "atypical" features, also differed from the other, pure carcinoids, in which the histologic appearance was "typical." Total gastrectomy performed 1 month after the original gastric resection with antrectomy disclosed regressive changes in the endocrine cell proliferations of the gastric stump consistent with the withdrawal of a stimulating effect of the antral gastrin.

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The morphological and functional characteristics of the endocrine cells of the oxyntic (acid-secreting) mucosa of the human stomach, a target of the trophic effect of gastrin, are reviewed. In healthy subjects these cells account for 0.90 +/- 0.35% of the volume of the entire mucosa and for 1.21 +/- 0.44% of the volume of the epithelial mucosal component alone. The cells show no extension to the glandular lumen and show an intimate anatomic relationship with contiguous non-endocrine epithelial cells. This configuration indicates undefined local functions of the paracrine type not influenced by the gastric lumen content. Seven cell types were identified ultrastructurally, three of which (enterochromaffin-like (ECL), P and D) cumulatively account for more than 75% of the total endocrine cell mass. The secretory product(s) of the endocrine cells has not been demonstrated definitively with the exception of minor cell populations producing glucagon (only in the fetal life), somatostatin and 5-HT. Recently, production of histamine and glycoprotein hormone alpha-subunit by oxyntic endocrine cells of man have been reported. However, histamine seems to occur in these cells normally, whereas the production of glycoprotein hormone alpha-subunit appears to be virtually restricted to cells of patients with hypergastrinaemic conditions.

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The actions of dopamine, apomorphine and serotonin on the membrane potential of cultured astrocytes from rat spinal cord and striatum were examined. All three compounds caused a hyperpolarization of the majority of astrocytes tested. A small number of cells was depolarized and on a relatively large number of cells the amines had no effect. The dopamine antagonists cis-flupenthixol and domperidone reversibly blocked the effects of dopamine whereas the action of serotonin was antagonized by ketanserin. It is therefore concluded that the effect of both amines are due to activation of specific dopamine and serotonin receptors, respectively. Our electrophysiological data together with autoradiographic binding studies provide evidence that astrocytes possess receptors for dopamine and serotonin in addition to adrenoceptors and histamine receptors.

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We studied serum lipids and post-heparin triglyceride lipase activities in 8 patients with Beta-Thalassaemia Major, under high transfusion programme and regular chelation therapy and in 8 control subjects. Total cholesterol and HDL-cholesterol were significantly lower in patients with Cooley's anaemia, whereas triglyceride levels did not differ in the two groups. Post-heparin triglyceride lipase activities were determined according with the method of Krauss et A1. using glyceryl-tri-(1-14C)oleate as substrate and NaCl to inactivate the extrahepatic lipase. These enzymatic activities (both hepatic and extrahepatic) resulted significantly lower in thalassaemic patients. We suppose that the decreased levels of these enzymatic activities could play a role in determining the decrease of HDL-cholesterol that we observed in our thalassaemic patients.

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In order to further investigate the behaviour of high density lipoproteins in diabetes mellitus, we studied HDL subclasses, HDL2 and HDL3, in 10 patients with newly detected, untreated insulin-deficient diabetes before starting insulin treatment and after getting a good metabolic control. We used the extractive method of Abell to determine HDL-cholesterol after LDL and VLDL precipitation with polyanions and HDL3-cholesterol after HDL2 precipitation with dextransulphate 15,000 m.w. After insulin therapy, we observed a significant increase in HDL-cholesterol and a decrease in serum triglycerides. Only HDL2-cholesterol, but not HDL3-cholesterol, raised; moreover, we found a significant inverse relationship between HDL-cholesterol (and also HDL2-cholesterol) and triglycerides. So, we think that an increase of lipoprotein lipase activity, owing to insulin treatment, could account for our results.

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