Intracerebroventricularly administered corticotropin-releasing factor releases somatostatin through a cholinergic,vagal pathway in freely fed rats

The aim of this study was to investigate whether corticotropin-releasing factor influences the plasma levels of somatostatin, gastrin or cholecystokinin when administered intracerebroventricularly to rats, and if such an effect could be vagally mediated, and dependent on the animals feeding states. Anaesthetized, freely fed rats were given 5 μl intracerebroventricular injections of corticotropin-releasing factor in four doses; 10 pmol-1.28 nmol. Immediately following death, trunk blood was collected for subsequent peptide analysis with radioimmunoassay (RIA). The three higher doses of corticotropin-releasing factor elevated the plasma levels of somatostatin (P < 0.01) after 20 min but left the plasma levels of gastrin and cholecystokinin unchanged. Intraperitoneal injections of 60 and 320 pmol of corticotropin-releasing factor did not influence the somatostatin levels. Further, intracerebroventricular injections of 60 pmol of corticotropin-releasing factor produced a peak increase in somatostatin after 20 min (P < 0.01). After 60 min the somatostatin levels were still increased (P < 0.05). Gastrin and cholecystokinin remained unaltered at these timepoints. Intracerebroventricular administration of 10 nmol of a-helical corticotropin-releasing factor 9–41 attenuated the basal levels of somatostatin and blocked the corticotropin-releasing factor-induced rise in somatostatin. Bilateral truncal vagotomy, as well as pretreatment with atropine (0.05 mg kg^-1, subcutaneously) abolished the effects of corticotropin-releasing factor on somatostatin. In animals which were food-deprived for 24 h, corticotropin-releasing factor did not influence somatostatin, gastrin or cholecystokinin. Pretreatment with cholecystokinin did not potentiate corticotropin-releasing factor-induced somatostatin release in food-deprived rats. These findings suggest that corticotropin-releasing factor acting within the central nervous system may regulate gastrointestinal functions partially through a cholinergic, vagally mediated release of somatostatin in freely fed, but not in food-deprived rats.     

Immunogenetic association in patients with antineutrophil cytoplasmic antibodies (ANCA) from Mumbai, Maharashtra, India

Considerable genetic evidence exit for ANCA-associated vasculitis and pathogenesis. HLA A and B alleles identified serologically from 84 ANCA-positive patients were compared with 101 controls. Further subtyping were done in the 27 "pauci-immune" vasculitis patients using the polymerase chain reaction based PCR-SSOP technique and compared with controls (67). The results revealed that HLA A1 (OR=4.00; p value 2.72E-05), B17 (OR=3.38; p value 0.0008) and HLA B40 (OR=2.74; p value 0.001) were significantly increased among ANCA-positive patients when compared with the controls. Further, the molecular subtypes A*0101 (OR=5.04; p value 0.0005), B*5801 (OR=4.47; p value 0.0002) and haplotype A*0101-B*5801 (OR=4.47; p value 0.0001) were significantly increased among the autoimmune patients. The study revealed that HLA A1, B17 and B40 alleles are associated in production of antineutrophil autoantibodies and A*0101-B*5801 haplotype is significantly associated with autoimmune diseases and they may be invariably involved in disease pathogenesis in India.     

Non-Hodgkin's lymphomas presenting with gastrointestinal involvement

Summary Between 1978 and 1983 a total of 33 patients with non-Hodgkin's lymphoma (NHL) involving the gastrointestinal tract were seen in our institution. Pathological classification was performed according to Kiel. Low grade NHL was diagnosed in 17, high grade NHL in 16 patients. The most frequent histological entity was lymphoplasmocytoid immunocytoma (11 patients). The most common sites of origin were the stomach (23 patients) and the ileocecal region (6 patients). The majority of patients presented with stage I and II disease (20 of 33 patients). As a rule primary therapy consisted of surgery with curative intent. Most of the patients received additional chemotherapy or radiotherapy. Patients with limited disease and complete tumour resection showed long-term survival from 12+ to 57+ months (mean 32.9+ months). Patients with advanced disease (stage III and IV) and only palliative surgery or with lymphoblastic lymphoma had a probability of survival of less than 12 months.Abbreviations NHL non-Hodgkin's lymphoma - IC lymphoplasmocytoid immunocytoma - CC centrocytic lymphoma - CB/CC centroblastic/centrocytic lymphoma - CB centroblastic lymphoma - IB immunoblastic lymphoma - LB lymphoblastic lymphoma - NWDL nodular well-differentiated lymphocytic lymphoma - NPDL nodular poorly differentiated lymphocytic lymphoma - NM nodular mixed lymphoma - NH nodular histiocytic lymphoma - DWDL diffuse well-differentiated lymphocytic lymphoma - DPDL diffuse poorly differentiated lymphocytic lymphoma - DM diffuse mixed lymphoma - DH diffuse histiocytic lymphoma - DU diffuse undifferentiated lymphoma - CT computerized tomography - GI gastrointestinal     

Real-time 3-D dark-field microscopy for the validation of the cross-linking process of alginate microcapsules

Alginate-based microencapsulation is a promising method for long-term maintenance of cellular and membrane function of the cells and tissue fragments required for in vitro and in vivo biosensors, for tissue engineering and particularly for immunoisolation of non-autologous transplants. Microcapsules of high mechanical strength and optimum permeability can be produced by injection of BaCl2 crystals into alginate droplets before they come into contact with external Ba2+. A key requirement is that the system parameters (number of crystals, speed of the crystal stream etc.) are properly adjusted according to the mannuronic and guluronic acid ratio and the average molecular mass of the alginate as well as to the diameter of the microcapsules. Robust, reliable, rapid and low-cost validation tools are, therefore, needed for assurance of the microcapsule quality. Here, we describe a novel three-dimensional (3-D) dark-field microscopy that allows the real-time measurement of the number and spatial distribution of the injected Ba2+ ions throughout the microcapsules after treatment with sulphate. This novel method requires only a conventional microscope equipped with three polarising filters and a double aperture stop. In contrast to confocal laser scanning microscopy images, peripherally attached BaSO4 precipitates can clearly be distinguished from internal ones. The data also demonstrate that several steps of the alginate gelling process must be improved before such immunoisolation can be used in patients.