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Biomedical subjects

J Piris

Publications and source records attributed to J Piris.

At least 19 recordsLinked to original sources
PubMed1991

Linked DNA markers for presymptomatic diagnosis of familial adenomatous polyposis.

41 symptom-free individuals aged 0-39 years who were at risk of familial adenomatous polyposis (FAP) were genotyped with six linked DNA probes. 28 individuals were informative for probes flanking the gene and 14 people assigned a probe-derived risk of over 0.93 were subsequently shown to be affected by clinical screening. 4 individuals who had been discharged from follow-up were designated high risk by this method. In those screened negative, risk was calculated from genotypic, colonic, and CHRPE findings and 89% of subjects had a risk below 0.003. An integrated risk analysis may have an important place in screening programmes for FAP.

Adenomatous Polyposis Coli↗
PubMed1991

MCC, a candidate familial polyposis gene in 5q.21, shows frequent allele loss in colorectal and lung cancer.

MCC is a gene located within human chromosome band 5q.21 that shows somatically acquired mutations in colorectal cancer, and may be identical to the gene responsible for inheritance of familial adenomatous polyposis. Here we demonstrate that alleles contiguous with or within MCC are deleted in a high proportion of sporadic colorectal carcinomas. Of 106 carcinomas that were informative concurrently at close-flanking sites both centromeric and telomeric to MCC, 41.5% showed acquired allele loss contiguous with MCC. Evidence is presented to show that the true frequency of loss of MCC alleles is higher still. In contrast, allele losses in chromosome 5 that were incompatible with involvement of MCC were very rare (2% of a total series of 201 informative tumours). Interstitial deletion was the commonest mechanism of allele loss, and L5.71-3, a probe known to include coding sequences of MCC, marks the most consistently deleted site. Moreover mapping of chromosome breakpoints with six probes within 5q.21 sited the common critical deletion in a 2.5 Mb region which included L5.71-3. However use of L5.71-3 itself suggested that critical deleted regions may lie on either side of the probed sequence. The simplest explanation for this unexpected finding is that MCC itself is the essential deleted gene, the lost exons lying sometimes centromeric to, sometimes telomeric to and occasionally within the region detected by L5.71-3. Tumours in which MCC-related alleles were lost by interstitial deletion were in general larger than those with other mechanisms of acquired homozygosity (e.g. mitotic recombination), but there were no other obvious associations with clinicopathological features. Between 20% and 25% of lung cancers also showed acquired allele losses contiguous with MCC. The significance of this observation is still to be determined, as lung tumours show allele losses at many other sites, but the specificity of the probes used in this study does establish that the 5q.21 losses in these tumours are compatible with involvement of MCC.

Adenomatous Polyposis Coli↗
PubMed1991

p53 expression in colorectal tumors.

The expression of the nuclear phosphoprotein p53 was studied immunohistochemically in a series of 150 benign and malignant colorectal tumors. Using monoclonal antibody PAb1801, tumors divided unequivocally into two groups on the basis of immunohistochemistry. Forty of the carcinomas (46.5%) showed positive staining but only 4 of the adenomas (8.7%) were positive (P less than 0.001). The few positive adenomas always showed moderate or severe dysplasia. Metaplastic polyps (n = 9) and small familial adenomatous polyposis-related adenomas (n = 9) were uniformly negative. Carcinomas with p53 expression did not differ from those without in terms of site, differentiation or the prognostic indicators of Dukes' stage, DNA ploidy, or tumor histology. The improved morphologic resolution available in periodate lysine paraformaldehyde dichromate (PLPD)-fixed, paraffin-embedded tissue permitted several conclusions to be made: p53 is confined to neoplastic nuclei; staining in positive tumors is heterogeneous and often more marked at the infiltrative margins; and staining intensity is dramatically reduced in mitotic cells. It is concluded that expression of immunohistochemically detectable p53 (probably representing mutated forms of the protein) occurs in some adenomas around the time of transition to carcinoma. Therefore there is an association with the appearance of infiltrative behavior but not with degree of tumor progression (including metastasis) at the time of resection.

Adenomatous Polyposis Coli↗
PubMed1990

Immunohistochemical demonstration of altered intracellular localization of the C-Myc oncogene product in human colorectal neoplasms.

The distribution of the c-myc oncogene product p62 was examined by immunohistochemistry using the monoclonal antibody Mycl-9E10 in a series of 50 colorectal resections for carcinoma. The specimens were specially handled to ensure rapid fixation in formalin, and a significant improvement was shown in the quality and localization of staining compared with routinely handled specimens. Non-neoplastic mucosa showed the presence of nuclear staining of epithelial cells in 93 per cent of the samples, whilst all carcinomas showed cytoplasmic staining and infrequent nuclear staining. Adenomas showed an intermediate pattern, with significantly more frequent cytoplasmic distribution than non-neoplastic mucosa, but less than carcinomas. The results show that whilst fixation conditions are important in the immunolocalization of the c-myc protein product, there may be a consistent difference between non-neoplastic mucosa and carcinoma in the manner of association of p62 with the nucleus.

Carcinoma↗
PubMed1989

Pharyngoesophageal dysmotility in globus sensation.

Ambulatory esophageal pH monitoring, radiologic examination, endoscopy, and manometry were undertaken in 142 patients with globus. The results demonstrate that abnormal gastroesophageal reflux occurred in 23% of patients, implying that, while reflux may be responsible for globus in some patients, it is not the cause of globus sensation in the majority of individuals with this symptom. Comparing patients with globus and control subjects, there were no differences in lower esophageal sphincter pressures, esophageal body motility, or tonic upper esophageal sphincter pressures, but patients with globus exhibited higher pharyngeal and upper esophageal sphincter after-contraction pressures during deglutition. The physiological significance of this pharyngeal and upper esophageal dysmotility is not clear and it may be no more than a secondary phenomenon. Alternatively, it may contribute to the generation of globus, perhaps in combination with other physical and psychological triggers.

Diagnosis, Differential↗
PubMed1989

Gastroesophageal reflux and posterior laryngitis.

Esophageal acid exposure was assessed by 23-hour ambulatory pH monitoring and compared with a biopsy of the posterior larynx and proximal esophagus in 97 patients with hoarseness, burning pharyngeal discomfort, or globus sensation. Patient results were compared with normal acid exposure times obtained in 54 control subjects. In 24 patients there were laryngeal abnormalities but both esophageal biopsy results and acid exposure times were normal. Laryngeal disease was found in association with prolonged acid exposure time or esophagitis in only 17 of the 97 patients (17.5%) studied. Recent reports appear to have overestimated the importance of acid reflux as a cause of posterior laryngitis.

Adult↗
PubMed1988

Optimal preservation of p21 ras immunoreactivity and morphology in paraffin-embedded tissue.

Specific immunostaining of p21 ras protein by the well-characterized pan-ras antibody Y13-259 is achieved in paraffin sections of human and animal tissues fixed in periodate-lysine-paraformaldehyde-dichromate (PLPD). Intensity of staining is as good as in cryostat sections, with superior histological detail. Localization to plasma membrane is demonstrated in rodent cells genetically manipulated to express abundant p21 ras (the FHO5T1 cell line), both in preparations suspended in agar after culture in vitro and in those growing as tumour in vivo. Strong positive staining is observed in neoplasms of human breast and colon, tissues in which there is independent evidence of elevated ras gene expression. The superior morphology afforded by this technique allows clear characterization of p21 ras expression in small premalignant lesions for which other methods of detection of oncogene expression are not appropriate.

Animals↗
PubMed1979

Comparison of disodium cromoglycate and sulphasalazine as maintenance therapy for ulcerative colitis.

In a trial lasting six months disodium cromoglycate (800 mg daily), sulphasalazine (2 g daily), and these two agents in combination were compared in 120 patients as maintenance treatment for ulcerative colitis. Relapse was defined as recurrence of colitic symptoms accompanied by sigmoidoscopic evidence of inflammation. The patients receiving disodium cromoglycate had a much higher relapse-rate than those taking sulphasalazine and the results with the two agents combined were little different from those with sulphasalazine alone. Disodium cromoglycate in the dose employed is greatly inferior to sulphasalazine as maintenance treatment for the prevention of relapse in ulcerative colitis.

Administration, Oral↗
PubMed1979

Small bowel strictures after blunt abdominal trauma.

Two patients with strictures of the small intestine after blunt abdominal trauma are reported. In the first there were multiple severe injuries and the ileal stricture due to a mesenteric tear was not diagnosed until 6 weeks later. In the second an apparently minor injury was responsible for direct damage to the wall of the jejunum and a subsequent stricture.

Adult↗
PubMed1979

Campylobacter colitis.

A patient is described in whom a campylobacter enteritis closely resembled ulcerative colitis on clinical, sigmoidoscopic, and histological grounds. Selective stool culture techniques may be necessary to differentiate campylobacter colitis from ulcerative colitis proper.

Adult↗
PubMed1979

Gastin cells and fasting gastrin levels in duodenal ulcer patients: a quantitative study based on multiple biopsy specimens.

The number of gastrin-producing cells in biopsy specimens from the gastric and duodenal mucosae in 19 duodenal ulcer patients was quantitated using a morphometric method. The level of immunoreactive gastrin in a sample of fasting serum obtained at the time of the biopsy was measured by radioimmunoassay. The results show no significant difference when compared with those from a group of normal control volunteers. Moreover, there was no correlation between the numbers of gastrin-producing cells and the fasting serum gastrin level in either controls or duodenal ulcer patients.

Adolescent↗
PubMed1979

Tissue eosinophils in ulcerative colitis.

A morphometric method has been used to quantitate eosinophils in the rectal lamina propria. The results from examination of paired biopsy specimens indicate that eosinophil distribution is uniform in the rectum. The number of eosinophils in specimens from patients with long-standing ulcerative colitis is significantly greater than that found in control subjects and increases with increasing clinical activity of the disease. In contrast, when biopsies are obtained from patients in a severe first attack of ulcerative colitis, eosinophil counts are not higher than in controls. The possible significance of these findings is discussed.

Cell Count↗
PubMed1978

Is bird fancier's lung associated with coeliac disease?

Precipitin responses to different avian serum antigens occur in bird fancier's lung (BFL) and coeliac disease. Failure to distinguish between them could encourage an erroneous diagnosis of BFL in patients with coeliac disease, and the recent suggestion that these two disorders are strongly associated may be questioned, partly for this reason. In the present study small bowel biopsy specimens were obtained from 12 of a series of 14 patients proved to have BFL by inhalation provocation tests. None was suggestive of coeliac disease. Of a further 61 patients with biopsy-proved coeliac disease, seven were found to be exposed currently and 33 formerly to birds. As a result of clinical evaluation, BFL was considered a possible cause of undue breathlessness reported by three of the current bird fanciers only, and all underwent inhalation provocation tests. One alone gave positive results. We conclude that if a real association does exist between these two disorders, its clinical importance has been greatly exaggerated.

Alveolitis, Extrinsic Allergic↗
PubMed1978

The role of various cereals in coeliac disease.

It is well established that the consumption of wheat gluten will produce the characteristic mucosal lesion of coeliac disease in subjects who are predisposed to it. The role of other cereals in the pathogenesis of this disease is less certain. In the present study, four different cereals (rye, barley, maize and rice) have been tested by feeding them to volunteer coeliac subjects who had shown good mucosal recovery on a gluten free diet and assessing the effect by serial jejunal biopsy. The biopsy specimens obtained before and after challenge were compared in terms of histology and disaccharidase activity. The results indicate that rye and barley are harmful but that maize and rice are harmless.

Adolescent↗
PubMed1977

An experiment to determine the active therapeutic moiety of sulphasalazine.

Sulphasalazine (S.A.S.P.) is of proven value in the treatment of ulcerative colitis, but its mode of action is unknown. When it is taken by mouth, nearly all the dose reaches the colon intact, where it is split by bacteria into sulphapyridine (S.P.) and 5-aminosalicylic acid (5-A.S.A.). An experiment was devised to determine whether the therapeutic property of S.A.S.P. is a function of the parent molecule or of these two principal metabolites. Retention enemas of S.A.S.P., S.P., and 5-A.S.A. were administered to volunteer patients with sigmoidoscopic evidence of active ulcerative colitis. The experiment was conducted as a blind controlled therapeutic trial, each patient having one of the test enemas daily for two weeks. Pronounced histological improvement was observed in approximately 30% of the patients receiving S.A.S.P. or 5-A.S.A., and in only 5% of those receiving S.P. It is concluded that the active therapeutic moiety of S.A.S.P. IS 5-A.S.A. and that the S.P. functions as a carrier ensuring that the 5-A.S.A. is liberated within the colon.

Administration, Topical↗