Design of a simple, in vitro method for evaluating the efficiency of crude Clostridium histolyticum collagenase and its components for porcine islet isolation

Abstract: The wide variability of different batches of crude collagenase is one of the major factors influencing the isolation of porcine islets of Langerhans. In order to enable the production of reproducible collagenase batches, however, it is first necessary to determine which of the many components of crude collagenase are required for porcine islet isolation. For this to be done, experiments must control for the inter-pancreatic variation seen with porcine pancreata, and this requires methodology that enables many different crude collagenases or collagenase components to be tested on any one pancreas. The aim of this study was to assess four different in vitro methods for evaluating different batches of crude collagenase. Each of the methods involved placing blocks of either distended or undistended pancreas in centrifuge tubes, adding crude collagenase in various concentrations dissolved in Hanks' and incubating the tubes in a waterbath at 35°C. The remainder of the pancreas was simultaneously processed using the semi-automated method. Every 10 min, samples were taken from both the semi-automated circuit and the relevant centrifuge tubes and assessed for number of cleaved islets, cleavage index, degree of fragmentation and quality of exocrine digestion. A correlation was made between each in vitro method and the "gold standard" semi-automated method. We conclude that it is possible to use an in vitro method to evaluate crude collagenase that correlates well with the digestion occurring in the Ricordi chamber and that enables the testing of many batches or components of crude collagenase on any one porcine pancreas.     

Evaluation of a training curriculum for nursing assistants

This is the report of a study undertaken as part fulfilment of the nurse tutor's course at Huddersfield Polytechnic. The purpose of the study was to evaluate nursing assistant training programmes at a mental illness unit in the Trent Region. The results suggest that the training curriculum in the unit where the study took place is effective in terms of teaching methods, lesson contents and consumer satisfaction (nursing assistants and charge nurses). The questionnaire survey supplied helpful comments on the training needs of nursing assistants. The conclusion is that it is not a waste of time to teach some elementary notions of nursing to nursing assistants.     

Sclerosing cholangitis: CT findings

The value of computed tomography (CT) in the detection of primary sclerosing cholangitis (PSC) in the intrahepatic and extrahepatic biliary systems was assessed by comparing CT scans of 20 cases of PSC with cholangiographic findings. In 16 of 19 cases of extrahepatic duct disease demonstrated with cholangiography, CT demonstrated abnormalities of the common hepatic duct, or bile duct, including duct stenosis, mural nodularity, duct dilatation, wall thickening, and mural enhancement. CT demonstrated intrahepatic disease in all 20 cases, including duct dilatation, duct stenosis, pruning, and beading. CT was superior to cholangiography in characterization of the status of the intrahepatic duct system in 11 of 20 cases. In addition, CT demonstrated extrabiliary complications of PSC in 12 cases and superimposed cholangiocarcinoma in three cases. While cholangiography remains the standard for diagnosis and follow-up of PSC, CT can provide valuable information about the extent and complications of the disease.     

TREATMENT OF COLD URTICARIA

Background. The etiology of cold contact urticaria is unknown and the therapy is therefore usually rather disappointing. Methods. This study reports therapeutic data on 42 patients with cold urticaria treated with a combination of terbutaline (3 × 5 mg a week, later 3 × 2.5 mg) and aminophylline-containing drugs (3 × 150 mg). Results. Complete remission of the urticarial response was achieved in 37 of the 42 patients. Conclusions. The therapy was tolerated relatively well and the results are promising.     

At which 'sigma' site are the spinal actions of ketamine mediated?

Electrophysiological experiments have been performed on rat spinal nociceptive reflexes to examine whether the spinal actions of ketamine are mediated at the haloperidol-sensitive sigma-site (which is particularly concentrated in the spinal ventral horn) or at the other site which has been referred to as sigma and which is characterized by phencyclidine (PCP), an antagonist of N-methylaspartate (NMA). The effects of ketamine on nociceptive reflexes were not affected by haloperidol 1-100 micrograms/kg i.v. The anticonvulsive agent MK-801, which is active at the PCP site but relatively inactive at the haloperidol-sensitive sigma-site, behaved like ketamine in reducing nociceptive reflexes at NMA-blocking doses; its actions were not affected by haloperidol at up to 1 mg/kg. Ketamine thus appears to manifest its spinal actions at the PCP site, a finding supportive of these spinal nociceptive reflexes being mediated by NMA receptors.