Arteriovenous Malformation of the Stomach

Of the multitude of sources capable of producing massive hemorrhage from the gastrointestinal tract, one of the rarest forms is arteriovenous malformation (AVM) of the stomach. The typical patient is a middle-aged male who presents with recurrent painless massive hematemesis and an unremarkable past medical history. Until recently the diagnostic work-up has often presented a dilemma, with the lesion rarely being confirmed prior to laparotomy. The patient whom we have encountertd with AVM of the stomach confirms our belief in the use of visceral angiography as a vital tool in the diagnosis of obscure gastrointestinal bleeding. We present this case as one which is unusual in its diagnostic work-up, therapeutic approach and pathologic findings.     

Elevation of gastric pH heals peptic oesophagitis - A role for omeprazole

The aim of this study was to investigate the hypothesis that the prolonged and substantial elevation of gastric pH which can be achieved with the antisecretory agent omeprazole will result in healing of peptic oesophagitis. Eight patients with erosive or ulcerative peptic oesophagitis were treated with omeprazole (30 mg daily) for 8 weeks. Complete healing occurred in seven patients after 8 weeks of omeprazole therapy. Only a small area of residual ulceration persisted in one unhealed patient. Heartburn resolved within the first 2 weeks of therapy in all but one patient. Specific food intolerances also were eliminated in most cases. Post-prandial oesophageal pH monitoring during omeprazole administration showed abolition of acid reflux episodes (pH < 4). This effect appeared to be due solely to the antisecretory effect of omeprazole, since motility measurements demonstrated a continued high frequency of reflux while concurrent gastric pH monitoring showed sustained elevation of gastric pH above 4. These results support the hypothesis that a prolonged and potent inhibition of gastric acid secretion renders refluxed gastric juice sufficiently innocuous to allow healing of severe peptic oesophagitis.     

BRUCELLOSIS COMPLICATED BY AORTIC VALVE ENDOCARDITIS

A 30 year old veterinary surgeon developed a febrile illness with serological evidence of Brucellosis. He was known to have aortic valve disease and during the course of the illness, the clinical features of endocarditis became evident, with a vegetation visible echocardiographically on the aortic valve. Because of persisting fever despite appropriate antibiotic therapy, aortic valve replacement with a viable cryopreserved allograft aortic valve was undertaken. Organisms consistent with Brucella species were demonstrated in the excised vegetation. The patient received a six week course of antibiotics and his post-operative course was uneventful.     

DESIGNING STUDIES FOR DOSE RESPONSE

‘Dose response’ refers to the regression of a response on a stimulus. We review a number of options for dose–response designs, and compare various designs which may be used in practice. We start with two group designs. Next, we introduce basic optimal approximate design theory for simple linear and quadratic regression illustrating different criteria of optimality and their effect on the allocation of the levels of the dose. Then we obtain the efficiencies of these optimal approximate designs and some simple designs which have intuitive appeal (symmetry, equal spacing of treatments, reduced numbers of observations at the highest and lowest doses).     

MUTATION OF THE VHL GENE IS ASSOCIATED EXCLUSIVELY WITH THE DEVELOPMENT OF NON-PAPILLARY RENAL CELL CARCINOMAS

To define the possible role of the VHL gene in the development of sporadic renal cell carcinomas, 91 different parenchymal tumours of the kidney have been investigated for mutation of the VHL gene by single strand conformation polymorphism (SSCP) and/or heteroduplex (HD) techniques. Chromosome 3p deletion was detected in 98 per cent of non-papillary renal cell carcinomas and in 25 per cent of chromophobe renal cell carcinomas. In 22 of the 43 non-papillary renal cell carcinomas, abnormally migrating DNA bands were detected by SSCP and/or HD analysis. No mobility shift was seen in any of the 23 chromophobe renal cell carcinomas. In addition, 15 papillary renal cell tumours and ten renal oncocytomas, which are characterized by genetic changes other than loss of chromosome 3p sequences, were analysed for mutation of the VHL gene. None of these tumours showed abnormal migration patterns. The results indicate that mutation of the VHL gene is associated exclusively with the development of non-papillary renal cell carcinoma.     

IMMUNOHISTOCHEMICAL ASSAY FOR OESTROGEN RECEPTORS IN PARAFFIN WAX SECTIONS OF BREAST CARCINOMA USING A NEW MONOCLONAL ANTIBODY

The aim of this study was to evaluate the utility of a new monoclonal antibody (AER311) that targets the oestrogen receptor (ER) in an immunohistochemical assay (IHA) applied to breast cancers. Ninety-seven cases of invasive ductal carcinoma were studied by AER311-IHA using a pressure-cooking antigen retrieval technique applied to formaldehyde-fixed, paraffin-embedded tissue sections; immunostaining was assessed by semi-quantitative scoring ( H score). There was 80 per cent concordance between the ER status measured by dextran-coated charcoal (DCC) assay and AER311-IHA, with 63/97 (65 per cent) tumours positive and 15/97 (15 per cent) tumours negative by both assays. Of the 12 DCC-positive cases that were negative by AER311-IHA, 11 were borderline positive (3–8 fmol/mg). Similarly, six of seven DCC-negative cases that scored positive by AER311-IHA had only borderline positive H scores (<50). When AER311-IHA was compared with 1D5-IHA, there was good concordance in ER status (77 per cent) and a significant correlation ( r =0·7, P <0·001) between H scores. Nevertheless, the correlation between ER level determined by AER311-IHA and that measured by DCC ( r =0·53, P <0·001) was higher than that for 1D5-IHA ( r =0·32, P =0·002). AER311-IHA can therefore provide reliable information about the ER status of breast carcinoma on paraffin sections and is an acceptable alternative to other commercially available monoclonal antibodies.