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Biomedical subjects

T Wheeler

Publications and source records attributed to T Wheeler.

At least 91 records · Page 5Linked to original sources
PubMed1988

Salvage radical prostatectomy for radiorecurrent adenocarcinoma of the prostate.

A total of 16 patients with persistent or recurrent prostate cancer 1 to 10 years after definitive treatment with radiotherapy underwent salvage radical prostatectomy. Patients considered to be candidates for the procedure were in excellent health, with a life expectancy of at least 10 years and with no evidence of extension of tumor beyond the prostate. There was no operative mortality but major complications included rectal injury in 3 patients (19 per cent, 1 requiring colostomy), ureteral transection in 1 (6 per cent), anastomotic stricture in 4 (25 per cent), ureterovesical junction stricture in 1 (6 per cent) and persistent urinary incontinence in 4. Whole organ step-section of the surgical specimen revealed positive surgical margins in 6 patients (37.5 per cent). Margins usually were positive at the apex and not at the bladder neck, so that cystoprostatectomy would not have altered the positive margin rate. Although the followup is too short for analysis of tumor recurrence or patient survival rates, the results indicate that salvage radical prostatectomy, although technically demanding, is feasible and that in the majority of properly selected patients the tumor can be removed completely.

Adenocarcinoma↗
PubMed1988

Isolated renal artery dissection secondary to medial degeneration.

Renal artery aneurysms can have variable presentations, often resulting in a therapeutic dilemma to the clinician. We review the causes, clinical features, pathological conditions and treatment options for this problem. We report a case of a thrombus in 1 of 2 left renal arteries, which resulted in uncontrollable hypertension. At nephrectomy the angiographically normal vessel had medial degeneration, demonstrating the diffuse nature of this disease. Conservative renal-sparing management should be considered whenever possible.

Adult↗
PubMed1987

Cost-benefit evaluation of body computed tomography.

Cambridge Health Authority accepted the gift of a whole body computed tomography (CT) scanner and radiotherapy planning system for Addenbrooke's Hospital (AH) from a local charity in 1981. The charity was to provide funds for the maintenance and all running costs for the first 5 years. Acceptance of the gift was conditional on an evaluation of the use of body CT before any decision about subsequent funding was made. The results of this evaluation are presented here. A detailed assessment fo 150 consecutive CT studies was performed together with an audit of CT use. The costs of running the CT unit and an indirect measurement of the benefits brought about by body CT were evaluated. In 86% of patients the CT findings were considered likely to have a great contribution to clinical management; in less than 10% was little or no benefit likely. In most patients (68%) CT was considered to have been more useful than any alternative test(s) would have been. The total cost of CT during the financial year 1983-84 was 219,163 pounds and the average cost per CT study was 73 pounds. The assessment indicated annual benefits fo 673,385 pounds including the saving of 3,880 inpatient bed days, 760 outpatient visits and alternative tests costing 290,684 pounds p.a. Some corroborative evidence that these benefits have occurred is presented. This study suggests a cost benefit ratio of 1:3.07.

Cost-Benefit Analysis↗
PubMed1987

Detection of fetal movement using Doppler ultrasound.

Using conventional cardiotocographic equipment with the ultrasound transducer placed to detect the fetal heart, we obtained unprocessed Doppler signals in the frequency range 13-70 Hz and used them to detect movements of the fetal trunk. In an assessment of maternal perception of fetal activity, we found that Doppler signals were associated with 739 of 780 appreciated movements (95%); however, 36% of all the Doppler signals were unaccounted for. A separate comparison of the Doppler signals against real-time ultrasound observations of fetal activity showed that 913 of 970 visualized trunk movements (94%) were associated with Doppler signals. Other Doppler signals were found to be due principally to fetal breathing and fetal hiccups. Appropriate processing of the Doppler signals obtained during antenatal cardiotocography may allow an objective assessment of fetal activity to be added to the fetal heart rate recording.

Female↗
PubMed1987

Testicular biopsy. Its use and limitations.

The need to distinguish ductal obstruction from ablative testicular pathology in the azoospermic patient is the primary indication for testis biopsy. Correct surgical technique and proper tissue processing are crucial to gaining the maximum amount of information from the biopsy specimen. The authors discuss the indications and techniques of testis biopsy and then review the major pathologic entities encountered clinically. Quantitative methods for describing the abnormal states of spermatogenesis are considered.

Adult↗
PubMed1986

Endodermal sinus tumor of the mediastinum. A report of seven cases and review of the literature.

Primary mediastinal endodermal sinus tumor is rare, and to date only 49 cases have been described in the English-language literature. Seven new cases are reported. Light microscopic examination showed characteristic features including papillary, reticular, tubular and solid growth patterns, complete or incomplete Schiller-Duval bodies and intracellular or extracellular periodic acid-Schiff-positive material. Immunohistochemical studies showed alpha-1-antitrypsin in seven, alpha-fetoprotein in seven, keratin in six, and carcinoembryonic antigen in four cases. The beta subunit of human chorionic gonadotropin, albumin, fibronectin, and transferrin were not found in any case. Electron microscopic studies performed in four cases showed intracellular and extracellular basement membrane-like material, multiple large multivesicular bodies, desmosomes and microvilli. Mediastinal endodermal sinus tumor can and must be differentiated from poorly differentiated adenocarcinoma metastatic or extending to the mediastinum because of the distinctly different prognoses and therapies. In spite of modern chemotherapy, the prognosis of mediastinal endodermal sinus tumor remains poor. The single most important prognostic indicator is whether the tumor mass can be completely excised before or after chemotherapy.

Adolescent↗
PubMed1984

Recombinant interferon in advanced breast cancer.

Fifteen patients with locally advanced refractory breast cancer have been treated with recombinant leucocyte interferon ( rIFN -alpha A) for up to 12 weeks. Toxicity was considerable with the initial dosage schedule employed but became acceptable after reducing the starting dose by 50%. Minor side effects occurred in all patients and major CNS toxicity in six. Nine patients showed some evidence of tumour regression at 4 weeks. Only two of these were still responding at 12 weeks. Response was unrelated to the length of previous history, oestrogen receptor status or previous responsiveness to cytotoxic or hormone therapy.

Adult↗
PubMed1983

Influence of Doppler ultrasound on fetal activity.

A randomised and double blind study of 100 subjects and 50 controls was performed to confirm or refute a report from Cardiff in 1975 that continuous Doppler ultrasound, as used in fetal heart rate monitoring, increases fetal movement by over 90%. The results showed such an effect to be most unlikely (power greater than 0.99). A total of 150 pregnant mothers recorded fetal movements for 30 minutes while connected to a specially modified cardiotocograph, the ultrasound being switched on at random for either the first or second 15 minutes in 100 of the patients. The mean difference in 15 minute movement count, with and without ultrasound, among the 100 patients was 0.2 of a movement (SD 12.7; p greater than 0.6 by two tailed Wilcoxon matched pairs signed ranks test). The control group showed a mean difference of 2.6 movements (SD 12.1; p greater than 0.2). Results of a pilot study suggested that the observations in the earlier report may have been influenced by mechanisms unrelated to ultrasound.

Double-Blind Method↗
PubMed1983

Neurological effects of recombinant human interferon.

Ten women with advanced locally recurrent breast cancer who had failed to respond to radiation and hormonal and cytotoxic agents were given up to 12 weeks of recombinant leucocyte interferon 20 X 10(6) U/m2 daily or 50 X 10(6) U/m2 three times a week. Within one hour of administration influenza-like symptoms began, which one week later were superseded by lethargy, anorexia, and nausea, with a consequent loss of weight in most patients. Other side effects included profound somnolence, confusion, paraesthesia, and (in one patient) signs of an upper motor neurone lesion in the legs. All these effects together with increased slow wave activity in electroencephalograms from all patients during treatment disappeared when interferon was withdrawn and did not recur on reintroducing the drug at a lower dosage. Studies are continuing to determine the mechanisms of these effects.

Adult↗
PubMed1982

Transforming gene of a human leukaemia cell is unrelated to the expressed tumour virus related gene of the cell.

The virally encoded oncogenes (v-onc) of avian and mammalian retroviruses are the recombinant products of normal cellular genes (c-onc) and a retroviral genome. These cellular homologues have been highly conserved during evolution and are found in human DNA. The expression of at least one c-onc under the control of a viral promoter results in transformation of cells in a manner resembling that displayed by the v-onc counterpart; the inappropriate expression of c-onc in the absence of viral influences could likewise result in the malignant state. This proposal would be strongly supported by the presence of c-onc RNAs in a variety of human tumours were they not also demonstrable in normal tissues. The role of these RNAs in the oncogenic process remains unclear. Here we report that RNA homologous to the oncogene (v-abl) of Abelson murine leukaemia virus (A-MLV) is expressed in a unique human leukaemia in a fashion different from that of other human tissues and tumours. In addition, DNA from this tumour transforms NIH-3T3 cells at a high efficiency in a transfection assay. The transfected sequences are not related to the v-abl gene, but the NIH-3T3 transformants manufacture a transforming growth factor which behaves similarly to factors produced by A-MLV-transformed NIH-3T3 fibroblasts.

Abelson murine leukemia virus↗
PubMed1982

Cells transformed by RNA and DNA tumor viruses produce transforming factors.

The RNA tumor viruses, Kirsten murine sarcoma virus (KiMSV) and Abelson murine leukemia virus, are shown to produce transforming factors (TFs) similar to sarcoma growth factor (SGF) produced by Moloney murine sarcoma virus-transformed 3T3 cells. TF production by KiMSV-transformed cells is dependent on the presence of a functional viral genome. TFs from KiMSV-transformed cells induce the transformed phenotype in normal cells, which suggests that the TFs play a integral role in transformation. We have extended TF production to DNA tumor viruses by demonstrating that cells transformed by simian virus 40 (SV40) and polyoma virus produce a growth factor or factors that render Rat-1 cells anchorage independent. The SV40-induced TF is not related to the KiMSV-induced TF. Last we demonstrate that cells vary in their sensitivity to TFs and propose that tumor cells have an increased responsiveness to TF-induced anchorage-independent growth.

Cell Transformation, Viral↗
PubMed1980

Changes in the fetal heart rate associated with fetal breathing and fetal movement.

Thirty-eight recordings of fetal heart rate and fetal activity were made from 21 normal patients between 36 and 41 weeks gestation. Each recording lasted for an average of 39 minutes. The heart rate was measured from beat to beat using the R-wave of the fetal electrocardiogram as the indicator of each heart-beat. Fetal breathing movements and fetal body movements were detected using either A-mode or B-mode ultrasound systems. The relation of fetal breathing and fetal movement to the fetal heart rate was studied both by cardiotachography and computer analysis of the R--R intervals. Fetal body movements (kicking and rolling) were usually associated with a brief tachycardia, the latter typically occurring every two to three minutes. In 14 recordings, the periods of fetal activity were interrupted by periods of fetal rest with an average duration of 12.5 minutes. Fetal breathing was seen in 26 of the 34 recordings analysed and occurred principally during the periods of fetal activity. Fetal breathing was associated with a significant increase in heart rate variation measured as the standard deviation of the R--R intervals and the mean absolute R--R interval difference. Sometimes a pattern of respiratory sinus arrhythmia was seen.

Electrocardiography↗
PubMed1979

Computer analysis of fetal heart rate variation during normal pregnancy.

Ninety-seven one-hour recordings of the abdominal fetal electrocardiogram (ECG) were made from 59 normal patients between 21 and 41 weeks of gestation. The heart intervals, measured between successive R-waves, were analysed by computer. The signal-to-noise ratio of the fetal ECG limited the precision of the interval measurements to approximately one millisecond. The characteristics of the baseline heart rate changed significantly as gestation advanced, the mean R-R interval, the standard deviation of the intervals and the standard deviation of the interval differences all increasing with gestation (p less than 0.001). In later gestation the baseline heart rate during periods of fetal rest differed significantly from that during periods of fetal activity; during rest the mean R-R interval was greater (p smaller than 0.001) and the standard deviations of the intervals and interval differences were smaller (p smaller than 0.001). Examination of the coefficient of variation of the heart intervals gave a result which contradicted the significance of this measurement as an index of fetal welfare as proposed by Curran and MacGregor (1970).

Analysis of Variance↗