Gastric persorption of bismuth from ranitidine bismuth citrate.

AIM: To determine whether bismuth penetrates the gastric mucosa after dosing with ranitidine bismuth citrate. METHODS: Twelve patients presenting with dyspepsia were randomized to receive either ranitidine bismuth citrate or placebo, 20-40 min prior to endoscopy. Biopsies were taken from four sites during endoscopy: the first and second parts of the duodenum, the antrum, and the body of the stomach. Biopsies were analysed by electron microscopy and X-ray microanalysis. RESULTS: Bismuth particles were found to be interposed between epithelial cells in the antral mucosa of three of eight patients who were dosed with ranitidine bismuth citrate. Columns of bismuth particles could be tracked down the lamina propria and were seen to be surrounding blood vessels. Bismuth particles were observed in the inter- and intra-cellular channels of the endothelial cells of the blood vessels in the lamina propria and also close to the luminal surface of the endothelial cell. This process of persorption was similar to that described in a previous report of electron microscopy appearances of the gastric antrum after dosing with tripotassium dicitrato bismuthate, but was quantifiably smaller and not observed in all the patients dosed with ranitidine bismuth citrate. No penetration of the mucosa by bismuth particles was seen in the body of the stomach or the duodenum. CONCLUSION: Penetration of bismuth particles into the gastric mucosa may occur after oral dosing with ranitidine bismuth citrate.

Gold granuloma after accidental implantation.

A case, in a 66 year old man, of a florid granulomatous reaction to gold dental alloy presenting about 20 years after accidental implantation in the oral mucosa of the lip is reported. Subsequent energy dispersive analysis confirmed the presence of a high nobility gold dental alloy. Florid granulomatosis has only rarely been reported in association with gold. Possible explanations for the delay in presentation include alteration of immune status or the development of hypersensitivity with components of the gold dental alloy acting as haptens.

Computer storage of toxicology methods and postmortem drug determinations.

Two data bases have been developed by toxicologists from the Department of Scientific and Industrial Research in New Zealand. The data bases are designed to store and retrieve postmortem drug and poison levels (TOXFILE) and methods used in drug and poison determinations (TOXMETH). TOXFILE contains a list of all the analytical results determined in toxicological cases received by the three laboratories. This method of storing the data has been found superior to the previously used card systems. The file also contains a reference to the analytical method which is very important for the interpretation of the results. TOXMETH contains a list of the analytical methods which have been developed and are in use in one or more of the three Chemistry Division toxicology laboratories. Methods can be added, modified and superseded as approaches change. A Chemistry Division Report (Pannell, L.K. et al., Chemistry Division Report No. CD: 2195, 1983) has been published containing all the programs and instructions. Copies of this are available from the authors on request. Computer magnetic tapes of the programs, the report and the data are also available. The names of the deceased on the TOXFILE data file are encrypted to provide increased security of the information. The TOXFILE data file which will be supplied on magnetic tape to overseas laboratories will have the name file on all records changed to 'CD' to provide complete confidentiality.

Determination of potentially toxic metals in human livers in New Zealand.

Ninety-six human liver samples from persons who died as a result of physical injuries in New Zealand have been analysed for arsenic, cadmium, chromium, cobalt, copper, mercury, lead, manganese, nickel, selenium, silver, and zinc. The levels found were generally lower than those found in similar studies outside New Zealand. Cadmium and lead levels showed a positive correlation with age and there did not appear to be any major regional variations within New Zealand.

Minimizing sample error in transmission electron microscopy.

The last few years have seen an increase in the use of electron microscopy, both for research and as a diagnostic tool in pathology. With the increase in the number of specimens being used for diagnostic purposes, limitations due to sampling error have become apparent. The method described is designed to help overcome this problem.

Transmucosal penetration of bismuth particles in the human stomach.

Electron microscopic examination of upper gastrointestinal biopsies with x-ray microanalysis was used to detect electron-dense particles of bismuth in the mucosa of the upper gastrointestinal tract, 30-60 minutes after oral dosing with either tripotassium dicitrato bismuthate [De-Noltab; Brocades (Great Britain) Ltd., Weybridge, UK; five patients] or bismuth salicylate (Pepto-Bismol; Richardson Vicks Ltd., Egham, UK; five patients), or without dosing (two patients). Transmucosal penetration of bismuth particles was observed in the gastric antral mucosa of all patients who had been dosed with tripotassium dicitrato bismuthate, but there was no penetration after oral dosing with bismuth salicylate. Persorption of bismuth particles through the gastric mucosa to the vascular endothelium provides an explanation for the rapid rise of plasma bismuth concentration observed only after oral dosing with tripotassium dicitrato bismuthate.

'Neuroendocrine' differentiation in primary neoplasms of the liver.

Thirty primary liver neoplasms (16 hepatocellular, nine biliary, and five epithelioid haemangioendotheliomas) were studied for the expression of the general 'neuroendocrine' markers, neurone specific enolase (NSE) and protein gene product 9.5 (PGP 9.5). Grimelius silver staining for neurosecretory granules and immunostaining for S100 protein, HMB-45, vasoactive intestinal polypeptide (VIP), and calcitonin were also performed. Eleven of the 16 hepatocellular carcinomas stained positively for PGP 9.5, four for NSE, six for HMB-45, and two for S100 protein. Seven exhibited granular staining by the Grimelius method; eight showed immunostaining for VIP, and two for calcitonin. Three of the five haemangioendotheliomas demonstrated positive immunostaining for PGP 9.5, and two for NSE; of the nine biliary carcinomas, two showed staining for PGP 9.5 and NSE, and four contained cells staining with the Grimelius technique. Primary neoplasms of liver may show 'neuroendocrine' differentiation and this aspect of their phenotypic expression has to be considered before predicting the site of origin of a tumour in the liver.

Pathological and microbiological findings from incidents of unusual mortality of the common frog (Rana temporaria).

In 1992 we began an investigation into incidents of unusual and mass mortalities of the common frog (Rana temporaria) in Britain which were being reported unsolicited to us in increasing numbers by members of the public. Investigations conducted at ten sites of unusual mortality resulted in two main disease syndromes being found: one characterized by skin ulceration and one characterized by systemic haemorrhages. However, frogs also were found with lesions common to both of these syndromes and microscopic skin lesions common to both syndromes were seen. The bacterium Aeromonas hydrophila, which has been described previously as causing similar lesions, was isolated significantly more frequently from haemorrhagic frogs than from those with skin ulceration only. However, as many of the latter were euthanased, this may have been due to differences in post mortem bacterial invasion. An iridovirus-like particle has been identified on electron microscopical examination of skin lesions from frogs with each syndrome and iridovirus-like inclusions have been detected in the livers of frogs with systemic haemorrhages. Also, an adenovirus-like particle has been cultured from one haemorrhagic frog. A poxvirus-like particle described previously from diseased frogs has now been found also in control animals and has been identified as a melanosome. Both the prevalence of the iridovirus-like particle and its association with lesions indicate that it may be implicated in the aetiology of the disease syndromes observed. Specifically, we hypothesize that primary iridovirus infection, with or without secondary infection with opportunistic pathogens such as A. hydrophila, may cause natural outbreaks of 'red-leg', a disease considered previously to be due to bacterial infection only.