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Biomedical subjects

M Corcoran

Publications and source records attributed to M Corcoran.

12 recordsLinked to original sources
PubMed1991

Urinary cytology in the detection of bladder carcinoma.

We have analysed the accuracy of cytological examination of voided urine in a population of 265 patients presenting with suspected bladder lesions. Bladder carcinoma was confirmed by tissue histopathology in 51 patients. Of these, 42 were identified correctly by urinary cytology examination. Overall 34 patients were labelled as frankly malignant on cytology, of whom 2 were negative on final histology. 13 patients had been designated as suspicious however with 3 benign on final histological diagnosis. These data give a sensitivity for diagnosis of bladder cancer by urinary cytology of 82%, a specificity of 97%, a positive predictive value of 94%, and a negative predictive value of 96%.

Adolescent↗
PubMed1991

Automated image-based cytometry with fluorescence-stained specimens.

The combination of digitized microscopy, algorithms for object recognition and fluorescent labeling is a promising approach for reliable, quick, automated and cost-effective screening of clinical specimens. We describe two conceptually different algorithms for detecting objects in fluorescence microscopic images. One, which is partially automated, compares a mask that represents a typical object with every position in the image; the other, which is fully automated, calculates threshold intensities to segment the image into regions of objects and background. Applications of the algorithms in conjunction with a prototype image-based cytometer are demonstrated for determining the DNA ploidy distribution of cultured human endometrial cells and determining the DNA ploidy distribution and the fraction of cells expressing the E6 antigen of human papilloma virus serotypes 16 and 18 in a PAP smear. The encouraging results from this study suggest that automated image-based cytometry utilizing fluorescent stains will be a valuable asset for clinical screening.

Algorithms↗
PubMed1990

Effect of dipyridamole on transport and phosphorylation of thymidine and 3'-azido-3'-deoxythymidine in human monocyte/macrophages.

Dipyridamole (DPM), a commonly used coronary vasodilator and antithrombotic drug, was shown recently to potentiate the antiviral effect of 3'-azido-3'-deoxythymidine (AZT) in HIV-1 infected human monocyte-derived macrophages (M/M) in vitro. We report in the present study that in uninfected M/M, DPM markedly inhibited cellular uptake of [3H]thymidine (dThd) and its incorporation into the nucleotide pools, particularly the dThd-triphosphate pool. In contrast, DPM did not affect cellular uptake and phosphorylation of [3H]AZT. Since dThd counteracts the phosphorylation and antiviral action of AZT, these findings support the hypothesis that the potentiation of the anti-HIV effect of AZT is due, at least in part, to differential inhibition of nucleoside salvage.

Biological Transport↗
PubMed1990

Conditioned taste aversion and motion sickness in cats and squirrel monkeys.

The relationship between vomiting and conditioned taste aversion was studied in intact cats and squirrel monkeys and in cats and squirrel monkeys in which the area postrema was ablated by thermal cautery. In cats conditioned 7-12 months after ablation of the area postrema, three successive treatments with xylazine failed to produce either vomiting or conditioned taste aversion to a novel fluid. Intact cats, however, vomited and formed a conditioned aversion. In squirrel monkeys conditioned 6 months after ablation of the area postrema, three treatments with lithium chloride failed to produce conditioned taste aversion. Intact monkeys did condition with these treatments. Neither intact nor ablated monkeys vomited or evidenced other signs of illness when injected with lithium chloride. When the same ablated cats and monkeys were exposed to a form of motion that produced vomiting prior to surgery, conditioned taste aversion was produced and some animals vomited. These findings confirm other studies indicating motion can produce vomiting in animals with the area postrema destroyed and demonstrate that motion-induced conditioned taste aversion can be produced after ablation of the area postrema. The utility of conditioned taste aversion as a measure of subemetic motion sickness is discussed by examining agreement and disagreement between identifications of motion sickness by conditioned taste aversion and vomiting. It is suggested that a convincing demonstration of the utility of conditioned taste aversion as a measure of nausea requires the identification of physiological correlates of nausea, and caution should be exercised when attempting to interpret conditioned taste aversion as a measure of nausea.

Animals↗
PubMed1990

Urethral valves--treatment, results and urodynamic assessment.

Posterior urethral valves is an uncommon condition, but it poses many diagnostic and therapeutic problems. Long term follow up of these patients revealed that the majority of these boys have long term problems. In depth assessment of 10 boys with this problem revealed that their upper urinary tracts remained stable whereas urodynamic studies showed gross micturition abnormalities. Most methods of assessing the urinary tracts in these boys are invasive (eg. Intravenous urography, micturating cystography) and may indeed show no change in upper tract radiology despite marked abnormalities of micturition detected by urodynamics and which may require further investigation and treatment. We therefore recommend regular urodynamic assessment of these boys as it is accurate and initially non-invasive. Those boys with a detectable abnormality can progress to further studies.

Child↗
PubMed1987

Indications for investigation of post-micturition dribble in young adults.

The endoscopic and urodynamic findings in eight male patients in whom post-micturition urinary dribble (PMD) was either the sole or predominant urinary symptom have been reviewed. In three patients whose only symptom was PMD, both endoscopic and videocystometric examinations were normal. In the remaining five patients with additional urinary symptoms, a functional or anatomical abnormality of the lower urinary tract was found in every patient. We conclude that in the assessment of patients with PMD, endoscopic and/or urodynamic investigation is of value only in those patients with multiple urinary symptoms.

Adolescent↗
PubMed1984

Computer programs for handling nucleic acid sequences.

Programs have been developed that will accurately display restriction enzyme maps, open translational reading frames and the results of specific searches on a high resolution graphics terminal (Retrographics VT640). Many of our earlier programs have been upgraded to allow online access to GENBANK, the NIH data bank of DNA sequences and also to deal with sequences of any length. Progress has also been made in the automation of the DNA assembly programs.

Amino Acid Sequence↗
PubMed1984

Surgical excision of first cleft branchial fistulae.

Three patients were studied who had fistulae in the neck derived from the first branchial cleft. Evidence is presented to show that although these fistulae usually pass superficial to the facial nerve they may also pass deep to one or both main divisions of the nerve. We conclude that a formal superficial conservative parotidectomy with full exposure of the facial nerve is the safest operative course when excising these fistulae.

Branchial Region↗
PubMed1983

Diagnosis of Bernard-Soulier syndrome and Glanzmann's thrombasthenia with a monoclonal assay on whole blood.

Two hereditary platelet disorders, Bernard-Soulier syndrome and Glanzmann's thrombasthenia, are characterized by selective deficiencies of platelet membrane glycoproteins. Murine monoclonal antibodies were developed against platelet membrane glycoprotein Ib and against the glycoprotein IIb/IIIa complex. A rapid whole blood assay for the deficiency of these glycoproteins was developed and used to study whole blood samples from six patients with Glanzmann's thrombasthenia and three patients with Bernard-Soulier syndrome. Patients with type I and type II Glanzmann's thrombasthenia were easily detectable with this assay. This permits the diagnosis of these disorders on 200 microliters of whole blood within 2 h of blood sampling.

Animals↗