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Biomedical subjects

J Beynon

Publications and source records attributed to J Beynon.

At least 55 records · Page 3Linked to original sources
PubMed1995

A case of pneumatosis coli managed by restorative proctectomy and ileal pouch-anal anastomosis.

Pneumatosis coli is a rare condition in which gas filled cysts occur in the wall of the intestines. Most symptomatic patients can be managed conservatively but those who fail medical management or who develop bowel obstruction will require surgery. Surgery usually involves a limited colectomy with a potential for recurrence. We describe a case of pneumatosis coli managed successfully by restorative proctocolectomy and ileal pouch-anal anastomosis.

Anastomosis, Surgical↗
PubMed1994

Alfalfa yield response to inoculation with recombinant strains of Rhizobium meliloti with an extra copy of dctABD and/or modified nifA expression.

The construction of rhizobial strains which increase plant biomass under controlled conditions has been previously reported. However, there is no evidence that these newly constructed strains increase legume yield under agricultural conditions. This work tested the hypothesis that carefully manipulating expression of additional copies of nifA and dctABD in strains of Rhizobium meliloti would increase alfalfa yield in the field. The rationale for this hypothesis is based on the positive regulatory role that nifA plays in the expression of the nif regulon and the fact that a supply of dicarboxylic acids from the plant is required as a carbon and energy source for nitrogen fixation by the Rhizobium bacteroids in the nodule. These recombinant strains, as well as the wild-type strains from which they were derived, are ideal tools to examine the effects of modifying or increasing the expression of these genes on alfalfa biomass. The experimental design comprised seven recombinant strains, two wild-type strains, and an uninoculated control. Each treatment was replicated eight times and was conducted at four field sites in Wisconsin. Recombinant strain RMBPC-2, which has an additional copy of both nifA and dctABD, increased alfalfa biomass by 12.9% compared with the yield with the wild-type strain RMBPC and 17.9% over that in the uninoculated control plot at the site where soil nitrogen and organic matter content was lowest. These increases were statistically significant at the 5% confidence interval for each of the three harvests made during the growing season. Strain RMBPC-2 did increase alfalfa biomass at the Hancock site; however, no other significant increases or decreases in alfalfa biomass were observed with the seven other recombinant strains at that site. At three sites where this experiment was conducted, either native rhizobial populations or soil nitrogen concentrations were high. At these sites, none of the recombinant strains affected yield. We conclude that RMBPC -2 can increase alfalfa yields under field conditions of nitrogen limitation, low endogenous rhizobial competitors, and sufficient moisture.

Base Sequence↗
PubMed1994

Rectum.

Explore the source record for details and available documents.

Humans↗
PubMed1993

Anal endosonography and correlation with in vitro and in vivo anatomy.

The endosonographic anatomy of the anal sphincters was studied by in vivo and in vitro correlation with anatomical dissection. Fourteen fresh anorectal specimens (eight abdominoperineal resection, six post mortem) were scanned in a water-bath with sequential dissection and correlation with the ultrasonographic images. Accurate anatomical identification of the layers during dissection was confirmed histologically. Anal endosonography was performed during operation in 12 patients to validate the in vitro findings. The in vivo study confirmed the in vitro results. Basic endosonographic anatomy has been clarified and inaccuracies in the previous description of the longitudinal muscle and external anal sphincter corrected.

Adult↗
PubMed1993

Spontaneous rupture of the oesophagus (Boerhaave's syndrome).

Five cases of spontaneous rupture of the oesophagus are reported. All cases had surgery within 12 hours, and all survived, illustrating the value of early diagnosis in this rare condition. None had their diagnosis made before admission to the hospital. Myocardial infarction is the commonest misdiagnosis and frequently results in delayed treatment. We believe that a simple direct question to enquire of the patient whether or not vomiting preceded the onset of the severe pain would significantly reduce the rate of misdiagnosis.

Adult↗
PubMed1992

Rectal endosonography accurately predicts depth of penetration in rectal cancer.

Sixty-three patients with primary rectal adenocarcinomas have been examined prior to surgery with rectal endosonography (ES). Maximum depths of tumour penetration measured endosonographically have been compared with subsequent maximum depths measured on the fixed resected specimen (n = 30) and the histological slide (n = 61). In both cases there was a good degree of correlation between the ultrasonic estimations of depth and the histological ones (r = 0.36, p = 0.05, CI = 95% and r = 0.46, p less than 0.001, CI = 99% respectively). In 12 cases ultrasonic depths of tumour were also measured in the laboratory and then compared with depths from fixed (n = 12) and fresh specimens (n = 5) with a good correlation (r = 0.75, p = 0.005, CI = 99% and r = 0.79, p = 0.036, CI = 95% respectively). Rectal endosonographic estimation of rectal cancer depth of invasion is an accurate measure of tumour penetration and may help distinguish between fixation due to inflammatory tissue and tumour fixity.

Adenocarcinoma↗
PubMed1989

Preoperative assessment of mesorectal lymph node involvement in rectal cancer.

One hundred patients with rectal adenocarcinoma were examined preoperatively with rectal endosonography (ES) and 50 were also examined with computed tomography (CT). ES predicted mesorectal lymph node involvement with an accuracy of 83 per cent, sensitivity of 88 per cent, specificity of 79 per cent, positive predictive value of 78 per cent and negative predictive value of 89 per cent. CT in comparison had an accuracy of 57 per cent, sensitivity of 25 per cent, specificity of 91 per cent, positive predictive value of 75 per cent and negative predictive value of 53 per cent. No particular histological architectural feature could be identified as responsible for false positive diagnosis though nodal size was significantly larger in the true positive and false positive group when compared with the true negatives (P less than 0.001 and P less than 0.01 respectively).

Adenocarcinoma↗
PubMed1989

Perioperative blood transfusion increases the risk of recurrence in colorectal cancer.

A retrospective study was conducted on 519 patients undergoing curative resection for colorectal carcinoma between 1969 and 1980. Recurrence was diagnosed in 214 patients (41.2 percent), 179 of whom (34.5 percent) had received blood transfusions and 35 of whom (6.7 percent) had not (P less than .001). Exclusion of the right-sided colonic tumors still showed that recurrence was more common in transfused than nontransfused patients (135 [47.2 percent] vs. 25 [22.5 percent]; P less than .001). Recurrence in patients transfused only during surgery (N = 201) was higher than in nontransfused patients (P less than .001) and, similarly, all patients transfused during surgery (N = 297) had an increased risk (P less than .001). Among patients with rectal cancer, transfusion increased the risk of recurrence in those treated by abdominoperineal resection (P less than .02), but this was not the case in those treated by sphincter-saving resection (P = .2). Hierarchical log linear analysis of all dependent factors (Dukes' stage, histologic grade, age, sex, site, elective, or emergency procedure) showed that Dukes' stage and blood transfusion had the most significant effects on the development of recurrence (chi 2 = 54.04, df = 6, P less than .0001 and chi 2 = 13.93, df = 3, P less than .003). The risk of recurrence following curative surgery for colorectal cancer is markedly increased by blood transfusion on the day of operation.

Adult↗
PubMed1989

The detection and evaluation of locally recurrent rectal cancer with rectal endosonography.

Eighty-five patients treated surgically for rectal cancer have been followed up by conventional clinical examination, sigmoidoscopy, and endosonography. Local recurrence was diagnosed in 22 patients. Nineteen of these had either sigmoidoscopic or digital evidence of recurrence and three were diagnosed solely by endosonography. In all cases endosonography gave additional information on which to base management decisions. Routine use of endosonography should allow the detection of early recurrence in a larger number of patients.

Adult↗
PubMed1989

Vaginal endosonography in the post-operative assessment of colposuspension.

Vaginal endosonography has been used to investigate the post-operative results of colposuspension. The anatomical relationships of the bladder neck, proximal urethra and symphysis pubis can be demonstrated with this technique. A successful symptomatic and anatomical result was observed in 29/40 women; 11/40 had persistent or recurrent symptoms at varying intervals after the operation. Four different anatomical configurations were associated with these symptoms, which included "early" and "late" recurrent stress incontinence, persistent incontinence, voiding difficulties and the frequency-urgency syndrome. Persistent or recurrent urinary symptoms were associated with a variety of anatomical configurations after colposuspension. Vaginal endosonography is a simple and convenient method to investigate the early and late post-operative results of operations for urinary stress incontinence.

Adult↗
PubMed1989

Physical and genetic map of the major nif gene cluster from Azotobacter vinelandii.

Determination of a 28,793-base-pair DNA sequence of a region from the Azotobacter vinelandii genome that includes and flanks the nitrogenase structural gene region was completed. This information was used to revise the previously proposed organization of the major nif cluster. The major nif cluster from A. vinelandii encodes 15 nif-specific genes whose products bear significant structural identity to the corresponding nif-specific gene products from Klebsiella pneumoniae. These genes include nifH, nifD, nifK, nifT, nifY, nifE, nifN, nifX, nifU, nifS, nifV, nifW, nifZ, nifM, and nifF. Although there are significant spatial differences, the identified A. vinelandii nif-specific genes have the same sequential arrangement as the corresponding nif-specific genes from K. pneumoniae. Twelve other potential genes whose expression could be subject to nif-specific regulation were also found interspersed among the identified nif-specific genes. These potential genes do not encode products that are structurally related to the identified nif-specific gene products. Eleven potential nif-specific promoters were identified within the major nif cluster, and nine of these are preceded by an appropriate upstream activator sequence. A + T-rich regions were identified between 8 of the 11 proposed nif promoter sequences and their upstream activator sequences. Site-directed deletion-and-insertion mutagenesis was used to establish a genetic map of the major nif cluster.

Amino Acid Sequence↗
PubMed1989

An evaluation of the role of rectal endosonography in rectal cancer.

The applications of rectal endosonography (ES) in the preoperative staging and follow-up of patients with rectal cancer have been investigated. Endosonography is an accurate method of staging local invasion (93%) preoperatively and is superior to digital examination (58%) and computed tomography (CT) (74%). In addition, ES can predict mesorectal lymph node involvement with an accuracy of 83% which compares favourably with CT (57%). Extrarectal, locally recurrent cancer can be detected using ES and established recurrence assessed more objectively.

Humans↗