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Biomedical subjects

I Taylor

Publications and source records attributed to I Taylor.

At least 253 records · Page 14Linked to original sources
PubMed1986

Effects of alcohol on hepatic haemodynamics in the rat.

The effects of varying rates of alcohol infusion (0.015-0.12 mg/g body weight/min) on hepatic haemodynamics were studied in male Wistar rats. An infusion of 0.015 mg/g body weight/min alcohol had no significant effect on portal pressure (PP) or wedged hepatic venous pressure (WHVP). However, increasing rates of infusion of alcohol (0.03-0.12 mg/g body weight/min) progressively increased PP and WHVP, the maximum increase in PP occurring following an infusion of 0.12 mg/g body weight/min (6.5 +/- 0.5 - 10.3 +/- 0.6 mm Hg). The effect of varying rates of alcohol infusion on portal venous flow and liver blood flow was biphasic. Thus following an infusion of 0.03 mg/g body weight/min alcohol, liver blood flow (40.6 +/- 4.9 - 54.3 +/- 5.8 ml/100 g/min) and portal venous flow (28.6 +/- 2.9 - 41.3 +/- 4.1 ml/min) were increased. However, following infusions of 0.06 and 0.12 mg/g body weight/min alcohol, liver blood flow and portal venous flow were decreased. The results suggest that previous conflicting reports on the effects of alcohol on hepatic haemodynamics may be related to the dose of alcohol administered.

Animals↗
PubMed1986

Symptomatic and incidental mammary duct ectasia.

The histology obtained from 1256 female patients undergoing breast surgery was reviewed. Mammary duct ectasia was noted in 51 (4.2%) patients who had associated symptoms and in 103 (8.1%) patients where duct ectasia was recognized as an incidental finding. The syndrome is defined by primary (nipple change or sepsis) and secondary (pain and lump) symptoms. Formal duct excision gives good results for symptomatic duct ectasia. It is postulated that many women have nonsymptomatic mammary duct ectasia. Secondary infection gives rise to nipple change, lump and pain. In the severe form abscess and fistula formation occurs which necessitates repeated surgical treatment, and rarely mastectomy.

Adult↗
PubMed1986

The quick-freezing of single intact skeletal muscle fibers at known time intervals following electrical stimulation.

Single intact frog skeletal muscle fibers quick-frozen after known time intervals following electrical stimulation are examined electron microscopically in thin sections, after freeze-substitution, in freeze-fracture/etch preparations, and in cryosections prepared for x-ray microprobe analysis. Techniques are described to perform these operations on a single fiber. Notable morphological differences between conventionally fixed and cryopreserved muscle fibers, and between fibers quick-frozen at different post-stimulation intervals are demonstrated.

Animals↗
PubMed1986

The accuracy of ultrasound in the diagnosis of breast disease.

The accuracy of breast ultrasound using all purpose static beta-scanning equipment has been compared with mammography. Ultrasound was found to be both more sensitive (93%:82%) and specific (95%:89%) in a large retrospective series of 1000 patients undergoing investigation for symptomatic breast disease. In a smaller prospective and consecutive series of 142 patients undergoing surgery where histological proof was obtained ultrasound was also found to be more sensitive (91%:81%) and specific (81%:69%). In both studies, the greater accuracy of ultrasound was attributed to its ability to diagnose lesions hidden in X-ray dense breasts and where mammography had revealed featureless asymmetical densities of uncertain nature. In these instances ultrasound may have a significant role to play as an adjunct to mammography in the preoperative assessment of breast lesions.

Breast Diseases↗
PubMed1986

Mastalgia; is this commonly associated with operable breast cancer?

A detailed analysis by questionnaire of breast pain in 460 newly referred patients at a specialized breast clinic revealed that only 1.5% of patients with pain had an early breast cancer. Of all 44 cancers 8 were painful but only 4 considered early. All these had nipple retraction. We conclude that although breast pain is rarely associated with cancer, localized pain must be fully investigated to exclude this diagnosis.

Breast Diseases↗
PubMed1985

A randomized controlled trial of adjuvant portal vein cytotoxic perfusion in colorectal cancer.

In this randomized trial adjuvant cytotoxic portal vein perfusion in patients undergoing surgery for colorectal cancer without liver metastases was assessed to determine whether the incidence of metachronous liver metastases could be reduced and survival thereby improved. There were 127 control patients and 117 patients who received adjuvant perfusion. A further 13 patients were excluded following randomization because of cirrhosis in 1, liver metastases at laparotomy in 3 and technical problems with cannulation in 9. Dukes' staging and degree of differentiation were similar in the two groups. There were fewer liver metastases in the perfusion patients and overall survival was improved. However, the benefit appears to be greatest in patients with Dukes' B colon cancer.

Aged↗
PubMed1985

Dynamic liver scanning in cirrhosis.

Dynamic liver scanning using 99mTc sulphur colloid has been used in assessing 41 patients with cirrhosis and the data compared with 33 control subjects. The mesenteric fraction (MF) was significantly reduced in cirrhotics (0.30 +/- 0.17) compared with controls (0.58 +/- 0.09), P less than 0.001. The liver: spleen ratio (L:S) was also significantly different (1.6 +/- 0.95 compared with 4.9 +/- 1.4), P less than 0.001. Those patients who had undergone a recent variceal bleed had values less than patients who had not bled. Dynamic scintigraphy may be of value in monitoring the progress of disease and response to treatment.

Adult↗
PubMed1985

Changes in colonic motility during the development of chronic large bowel obstruction.

The effect of chronic progressive distal large bowel obstruction on colonic motility was studied in six mini-pigs. Motility was detected in vivo during the development of obstruction with chronically implanted Ag/AgCl electrodes using an impedance technique. When the obstruction was complete the segments of bowel were resected and spontaneous contractile activity and response to cholinergic stimulation were studied in an organ bath. Any hypermotility resulting from obstruction was shortlived and a gradual state of hypomotility supervened proximal to the obstruction. Decompression of the bowel did not result in the immediate return of motility and the resected bowel was unresponsive to carbachol. These results suggest that spontaneous resolution of large bowel obstruction is unlikely and that motility disturbances are unlikely to be a cause of anastomotic dehiscence.

Animals↗
PubMed1985

An assessment of occult blood testing to determine which patients with large bowel symptoms require urgent investigation.

One hundred and fifty-two consecutive patients with symptoms suggestive of colorectal disease were offered occult blood testing before undergoing barium enema examination or colonoscopy; one hundred and thirty-nine successfully completed the test. Thirty-four had positive results of whom thirteen had a cancer and eight an adenomatous polyp (diagnostic yield for neoplasia of 59 per cent). No false negative results occurred, a sensitivity of 100 per cent, and only 21 false positives occurred, a specificity for malignancy of 84 per cent. Subjects attending outpatients should be offered occult blood testing; those with a positive test should undergo colonoscopy. The cost-benefit of such a scheme is emphasized.

Aged↗
PubMed1985

Accuracy of aspiration cytology in the diagnosis of breast disease.

The accuracy of fine needle aspiration cytology has been assessed in 480 consecutive breast lesions where definitive histology was later available. The results in terms of specificity and sensitivity have also been compared to mammography and clinical examination. With adequate smears aspiration cytology was 100 per cent specific with no false positive diagnosis. This compares with 15 false positive mammograms and 12 false positive diagnoses on clinical examination. Cytology was unsatisfactory in 36 per cent of benign lesions owing to poor cellularity of the sample but when considered with mammography and examination led to a reduction in biopsies for benign disease. A definitive cytological diagnosis of malignant tumours resulted in a reduction in frozen sections with a substantial saving of resources and improvement in patient counselling. No mastectomy was performed for benign disease.

Biopsy, Needle↗
PubMed1985

Modulation of transferrin receptor expression by inhibitors of nucleic acid synthesis.

We investigated the effects of the iron chelator desferrioxamine on the expression of transferrin receptors (TfR) by CCRF-CEM human T-cell leukaemia and B16 mouse melanoma cells growing in tissue culture. Desferrioxamine (DFOA) enhanced TfR expression when added in the dose range of 10(-5)-10(-4) to CCRF-CEM cells, but was toxic to these cells, the lower concentrations producing a slowing of cell growth with a build up in S-phase, while higher concentrations caused cell death with a block at the G1/S-phase interface. These toxic effects are compatible with its previously reported inhibition of the non-haem iron containing (M2) subunit of ribonucleotide reductase. In marked contrast, DFOA caused the growth of B16 melanoma cells to arrest in G1, without loss of cloning efficiency, and resulted in a fall in TfR expression to approximately 50% of control values. These results suggested that the effects of DFOA on TfR expression were linked to DNA synthesis rather than to a more generalised inhibition of iron-dependent cellular processes. It was subsequently found that inhibition of the M2 subunit of ribonucleotide reductase in CCRF-CEM cells with 5 X 10(-5) M hydroxyurea, which is not an iron chelator, also enhanced TfR expression, as did thymidine and cytosine arabinoside, which have different enzyme targets. By measuring cellular DNA and RNA content simultaneously it was shown that all of these agents caused unbalanced growth, i.e., inhibited DNA synthesis more than RNA synthesis. In contrast, 6-thioguanine was more inhibitory to RNA synthesis, and treatment with this drug caused a fall in TfR expression. Thus, although CCRF-CEM cells treated with DFOA show enhanced TfR expression, similar effects are also seen with other inhibitors of DNA synthesis, provided that RNA synthesis is allowed to continue. These results provide further evidence that the regulation of TfR expression by proliferating cells is specifically linked to DNA synthesis rather than to the iron requirements of other cellular processes.

Animals↗
PubMed1985

The effects of vasopressin on hepatic haemodynamics in the cirrhotic and non-cirrhotic rat.

Liver blood flow (xenon-133 clearance method) and portal venous flow were measured in cirrhotic and non cirrhotic rats following the infusion of vasopressin at varying rates. At low rates of infusion, vasopressin had no significant effect on portal venous flow or liver blood flow in cirrhotic or non-cirrhotic rats. Infusion of vasopressin at a rate of 0.08 microU/g body wt/min in non-cirrhotic rats and 0.04 and 0.08 microU/g body wt/min in cirrhotic rats decreased portal venous flow and increased liver blood flow. At higher rates of infusion (0.2 microU/g body wt/min in non-cirrhotic rats and 0.16 microU/g body wt/min in cirrhotic rats) these effects were reversed. Furthermore, an infusion of 0.08 microU/g body wt/min vasopressin significantly reduced portal pressure in the cirrhotic rat. However, portal pressure was not significantly altered following an infusion of 0.16 microU/g body wt vasopressin. The implications of these findings in relation to the possible deleterious effects of high rates of vasopressin infusion in the management of portal hypertension and bleeding oesophageal varices is discussed.

Animals↗
PubMed1985

A dimethylnitrosamine-induced model of cirrhosis and portal hypertension in the rat.

A method of producing cirrhosis consistently in rats by the administration of dimethylnitrosamine (DMNA) is described. Two weeks following the cessation of DMNA treatment there was distortion of the lobular architecture of the liver and some focal nodule formation. This 'pre-cirrhotic' state was accompanied by portal hypertension, biochemical abnormalities and the development of ascites. The mortality 2 weeks after cessation of DMNA was 42%. Twenty-four weeks after DMNA treatment cirrhosis had developed with diffuse nodularity and fibrosis, marked portal hypertension, and accumulation of ascites. There was also a deterioration in liver function, with hypoproteinaemia and jaundice. The overall mortality 24 weeks after the cessation of DMNA treatment had risen to 52%. This model of cirrhosis in the rat may be useful in evaluating the efficacy of drugs in the long-term management of portal hypertension in man.

Animals↗
PubMed1985

The prognostic value of the monoclonal antibodies HMFG1 and HMFG2 in breast cancer.

The monoclonal antibodies HMFG1 and HMFG2 identify antigens of the milk fat globule membrane which are also found on breast epithelial cells. Immunohistochemical staining was performed using both antibodies on formalin fixed, paraffin embedded sections of 93 breast carcinoma, 36 histologically benign lesions and 29 histologically normal breast tissue blocks. In both normal and benign breast disease the staining was largely extracellular whilst in malignant tissue the staining was variable and often intracellular. Nine carcinomas did not stain with either antibody. The staining patterns of malignant tissues were graded and no correlation was found between the grades and survival or indices of prognosis, (the oestrogen receptor status, Bloom's grade and the presence or absence of metastases to the axillary nodes.) This study indicates that with the present methods available for grading staining patterns, although of diagnostic value, these monoclonal antibodies are unlikely to assist in determining either the degree of tumour differentiation or prognosis in breast carcinoma.

Antibodies, Monoclonal↗
PubMed1985

The clearance of Xenon-133 following its parenchymal injection: a rapid method for estimating functional liver blood-flow.

Portal venous flow, total hepatic blood-flow and hepatic artery flow were measured in healthy dogs by electromagnetic flowmetry and a double indicator dilution technique. Functional liver blood-flow was measured by the double indicator dilution technique. Functional hepatic blood-flow did not correlate with portal venous flow, total hepatic blood-flow or hepatic artery flow, measured by either electromagnetic flowmetry or a double indicator dilution technique. There was a good correlation (r = 0.83, P less than 0.001) between functional hepatic blood-flow and liver blood-flow, measured by the clearance of Xenon-133 injected directly into the liver parenchyma. It is concluded that the clearance of Xenon-133, injected directly into the liver parenchyma, is a rapid and simple method for measuring functional hepatic blood-flow.

Animals↗