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Biomedical subjects

G Read

Publications and source records attributed to G Read.

At least 37 records · Page 2Linked to original sources
PubMed1993

Audit: the use of radiotherapy for NSCLC in the UK.

A questionnaire on the management of NSCLC was sent to all clinical oncologists in the UK. Responses were received from 121 individuals with at least one representative response from each of 54 British radiotherapy units. Results were then discussed at an open meeting attended by a cross section of clinical oncologists; a synopsis of responses to the questionnaire and discussion at this meeting is contained in this report. A majority of respondents estimated treatment of NSCLC to make up 10%-25% of their work-load. Radical and palliative treatments could be clearly distinguished, and aims of treatment, selection criteria and radiotherapy schedules were consistent with recommendations in the published literature. More than 90% of treatments were with palliative rather than radical intent. Radical treatment schedules could be divided according to dose (< 50 Gy, 50-55 Gy and >55 Gy), number of fractions (< 20, 20, > 20 fractions), overall time < 4/52, 4/52, > 4/52), dose per fraction (> 2.75 Gy, 2.1-2.75 Gy, < or = 2 Gy) and target volume (tumour alone, tumour and hilar nodes, or tumour, hilar and mediastinal nodes). Divided thus, radical techniques fell into three broad groups, each of the three techniques supported by a body of literature. Choice of schedule could be related to a heterogeneous referral pattern and unresolved controversies, identified as debate on the value of treating mediastinal lymphadenopathy with high dose radiation, the value of 'subradical doses' of radiation for microscopic disease, and the relative importance of volume treated, total dose, dose per fraction and overall treatment time in achieving an optimal therapeutic ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Non-Small-Cell Lung↗
PubMed1993

Standardization of hapten immunoprocedures: total cortisol.

The broad objectives of this report are to enhance the clinical utility of the results of hapten measurement immunoprocedures by encouraging standardization of the procedures. It was decided to restrict the subject of the report to one analyte, and cortisol was chosen because of its diagnostic importance, the need for improved comparability with routine procedures, and its relevance to many other analytes. Therefore, the immediate objectives are to improve the clinical utility of total serum cortisol concentrations measured on different occasions and in different laboratories, to make diagnostic reference intervals more reliable and widely applicable, and to improve diagnostic accuracy by: Improving the agreement between results from reference measurement procedures and the results obtained with normal routine immunoprocedures for the measurement of total serum cortisol, and hence the comparability of routine results; and Reducing the susceptibility of the immunoprocedures to crossreactivity and interference. It is recognized that good comparability of results depends on procedures which are specific, properly calibrated and validated, and that the most important factors are resistance to crossreactants and interferants. Analytical goals for cortisol immunoprocedures are zero bias for 'all' samples with respect to a reference procedures, with the total analytical standard deviation equal to, or less than, half the within-individual standard deviation for cortisol, or 7.6% according to a recent estimate. To these ends the group proposes the following measures: 1. An international network of reference laboratories for cortisol measurement should be established, and progressively developed to include other hapten analytes. The service of the participating laboratories would be necessary to make feasible other recommendations listed below. 2. Procedures should be comprehensively validated, including a thorough crossreactivity study with the results presented to indicate the possible significance of each crossreactivity, a direct comparison of results with those obtained by a reference procedure for an adequate number of varied fresh/frozen patient samples, and suitable clinical validation studies. 3. External quality assessment schemes should assess participating laboratory performance against reference procedure values, and not consensus values related to values determined by any group of participating procedures. They should also assess the ability to determine added standard and to resist common interferants. 4. Master calibrators for use in the production of calibrators included in commercial kits, and formulated identically to these, should be certified with at least one reference measurement procedure, so that the concentrations of analyte in calibrators can be traced back to concentrations determined by a reference procedure.(ABSTRACT TRUNCATED AT 400 WORDS)

Humans↗
PubMed1992

The role of the renal nerves in renin synthesis.

1. Renin synthesis and secretion were studied in Balb/c mice with a denervated left kidney. 2. Denervation inhibited renin secretion. 3. Denervation reduced the renal renin content. 4. Denervation reduced renal renin mRNA. 5. Renal denervation inhibits renin secretion by blocking the synthetic system prior to mRNA formation.

Animals↗
PubMed1992

Salivary testosterone levels and major depressive illness in men.

Studies of testosterone levels in patients with major depressive illness have produced varying results, plasma levels usually being reported. Saliva levels reflect 'free' plasma testosterone, and a pilot study of 11 men with major depression with melancholia, who underwent a standard dexamethasone suppression test, is described. There were no significant differences in testosterone levels compared with an age-matched control group. In the patient group, pre-dexamethasone levels correlated significantly and negatively with depression ratings on the 21-item Hamilton and the Montgomery and Asberg depression scales, and also with state anxiety measured on the Spielberger scale.

Adult↗
PubMed1992

Medical Research Council prospective study of surveillance for stage I testicular teratoma. Medical Research Council Testicular Tumors Working Party.

PURPOSE: A prospective study of surveillance after orchidectomy alone in patients with stage I nonseminomatous germ cell testicular tumor (NSGCT) was performed to determine the relapse-free rate and to identify the histologic criteria that predict for relapse. PATIENTS AND METHODS: Three hundred ninety-six patients from 16 United Kingdom and one Norwegian centers were entered onto the study between January 1, 1984 and October 1, 1987 of whom 373 were eligible for analysis. In a previous retrospective study, we defined a prognostic index based on histologic criteria that identified a group of patients with a high risk of relapse. This index was based on the presence of venous and lymphatic invasion, undifferentiated cells, and the absence of yolk sac elements in the primary tumor. RESULTS: The 2-year actuarial relapse-free rate after orchidectomy was 75% (95% confidence interval, 71% to 79%), and the rate at 5 years was 73%. Five patients died of tumor or treatment-related complications, which resulted in a 5-year survival of 98%. The relapse-free rate in patients with three or four risk factors was 54%. CONCLUSIONS: This study confirms the safety of surveillance as a method of management and identifies a group of patients with a high risk of relapse. A prospective phase II study has been initiated to determine whether two courses of platinum-based adjuvant chemotherapy will prevent relapse in these high-risk patients.

Adult↗
PubMed1991

Determination of 25-hydroxyvitamin D3 in human serum by fluorescence labelling and high-performance liquid chromatography.

A method is described for the determination of 25-hydroxyvitamin D3 in human blood serum. The problems of sensitivity and selectivity encountered with previous techniques were avoided by the formation of a highly fluorescent Diels-Alder adduct following solid-phase extraction of the vitamin. After excess of reagent had been eliminated, quantification was achieved by high-performance liquid chromatography. The recovery of the vitamin from serum was 76.4 +/- 1.76%. The precision of the method was determined, and the relative standard deviations were 8.38% at a concentration of 47.0 x 10(-9) mol dm-3, 6.74% at a concentration of 99.8 x 10(-9) mol dm-3 and 3.79% at a concentration of 146.8 x 10(-9) mol dm-3. The detection limit for the adduct was 2.93 x 10(-14) mol injected, for a signal-to-noise ratio of 3:1, and serum concentrations of 0.25 x 10(-9) mol dm-3 could easily be quantified. No interference from endogenous or exogenous substances was observed.

Calcifediol↗
PubMed1990

Seasonal variation and the results of the dexamethasone suppression test.

There is controversy over the presence of a circannual rhythm in cortisol values in samples provided by depressed patients after a standard dexamethasone suppression test (DST). Post-DST cortisol values from patients admitted to an acute psychiatric ward over a 2-year period have therefore been analysed by appropriate statistical tests. No evidence was found for significant seasonal variation.

Depressive Disorder↗
PubMed1990

Accuracy in staging carcinoma of the bladder by magnetic resonance imaging.

Thirty-four patients with a presumptive diagnosis of carcinoma of the bladder diagnosed at EUA and cystoscopy have been staged by MRI and the findings correlated with pathology in 15 patients and clinical follow-up, including repeat cystoscopy, in the remainder. MRI is accurate in identifying tumours confined to the bladder wall or extending beyond the wall to involve perivesical fat or adjacent organs. Whilst it is not possible to distinguish between T1, T2 or early T3a tumours they can be distinguished from advanced T3a lesions and this may affect management. MRI is superior to clinical staging, particularly in detecting lymphadenopathy and provides information for optimal radiotherapy planning. The problem of distinguishing between the effects of radiotherapy and suspected recurrent tumour is discussed.

Aged↗
PubMed1989

Retrospective study of radiotherapy in early carcinoma of the prostate.

During the years 1978 to 1983 there was a 10-fold increase in the number of patients with T1-T4 NX M0 carcinoma of the prostate referred to the Christie Hospital for radical radiotherapy. A retrospective survey of 170 patients treated during this period showed an overall age-corrected 5-year survival rate of 49%. The survival of patients in whom referral for radiotherapy had been delayed was 37% compared with 56% for those given immediate treatment. Patients with poorly differentiated tumours had a significantly reduced survival compared with those with well differentiated tumours. The overall complication rate from radiotherapy was 4% and this low rate is attributed to the small volume used uniformly for treatment.

Aged↗
PubMed1989

The hormonal environment of post-natal depression.

The incidence of post-natal depression is high, and dramatic changes in steroid hormones and prolactin occur in the post-partum period. In an attempt to correlate these events, 147 mothers, six to eight weeks after delivery of a healthy infant, completed standard psychological tests, including the Edinburgh, Montgomery-Asberg, and Raskin scales. They also provided matched samples of plasma for assay of cortisol, oestradiol, progesterone and prolactin, and saliva for assay of cortisol and progesterone. All steroid concentrations were within the appropriate normal ranges. Of the mothers, 14.9% were depressed on all three scales. Significant correlations were seen between depression ratings and salivary progesterone and prolactin. In bottle-feeders, salivary progesterone was positively associated with depression, whereas in breast-feeders it was negatively associated. Plasma prolactin levels were inappropriately low in depressed breast-feeders. These data indicate that differing therapies may be appropriate for depression in breast- and bottle-feeders.

Adolescent↗
PubMed1989

Vulnerability of the human Leydig cell to radiation damage is dependent upon age.

Testicular function was studied in three groups of patients previously treated for malignant disease, and a control group of adult males. The adult patients in groups one and two underwent unilateral orchidectomy for a testicular tumour but only in group two was this followed by post-operative high-dose irradiation (30 Gy) to the remaining testis. Four of the five boys in group three had a unilateral orchidectomy between the ages of 1 and 4 years and all five received a similar dose of irradiation (27.5-30 Gy) to the scrotum as in group two. The five subjects in group three were studied between the ages of 12 and 34 years. In group one the median basal testosterone level (16.0 nmol/l) was normal and the basal gonadotrophin levels mildly but significantly increased, reflecting a resetting of the pituitary-testicular axis following unilateral orchidectomy. In group two the median basal testosterone level (12.5 nmol/l) was significantly lower and the median basal FSH and LH levels were significantly higher than the respective values in group one, indicating that irradiation to the testis in adult life may damage both the germinal epithelium and the Leydig cells. All five males in group three showed grossly increased FSH and LH levels, with a median basal testosterone level (less than 2.5 nmol/l) significantly lower than groups one and two. None of the five showed a testosterone response to a stimulation test with human chorionic gonadotrophin or underwent puberty spontaneously.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Pseudo malonaldehyde activity in the thiobarbituric acid test.

In the thiobarbituric acid test for malonaldehyde, 2-hexenal, 2,4-hexadienal and 13-hydroperoxy-9Z,11E-octadecadienoic acid are found to form the characteristic 532 nm chromogen, at pH = 2.7 and at elevated iron(III) levels, faster than malonaldehyde itself. Under the same conditions, but in the presence of EDTA, the chromogen formation is dramatically suppressed. The findings show that malonaldehyde cannot be generated in situ and are interpreted in terms of chromogen formation via an iron catalysed fragmentation of TBA-aldehyde intermediates.

Chemical Phenomena↗
PubMed1988

The treatment of advanced seminoma with chemotherapy and radiotherapy.

Between 1979 and 1984 thirty-seven patients were treated with combination chemotherapy for metastatic seminoma; 27 of these had relapsed following initial radiotherapy for stage I and IIA disease and 10 patients with stage IIB-IV disease received chemotherapy de novo followed by radiotherapy to sites of bulk disease. Treatment consisted of either a cis-platinum containing combination (25 patients), or cyclophosphamide and etoposide (12 patients). The overall survival of all patients at 5 years was 49%, 34 patients were assessable for response; a CR was obtained in 8 (24%) and a GPR in 19 (56%), the 5 year survival of this group being 66% at 5 years. No difference in survival was seen in relation to age, previous irradiation, serum HCG or LDH; bulk disease however, was an adverse prognostic factor. Survival was similar for both chemotherapy schedules but neutropenia and life-threatening sepsis was less with the cyclophosphamide etoposide combination.

Adult↗
PubMed1987

Histopathology in the prediction of relapse of patients with stage I testicular teratoma treated by orchidectomy alone.

259 patients with stage I non-seminomatous germ-cell testicular teratoma who were treated by orchidectomy alone and monitored at one often centres in the United Kingdom were followed for a median of 30 months. 62 of the 70 relapses occurred in the first 18 months after orchidectomy. The 2-year relapse-free rate was 74%, falling to 68% at 4 years. Histological sections from 233 of the orchidectomy specimens were reviewed centrally. Four features independently predicted relapses: invasion of testicular veins, invasion of testicular lymphatics, absence of yolk-sac elements, and presence of undifferentiated tumour. An index, based on the number of these features observed, identified a high-risk subgroup of 55 patients who had a 42% relapse-free rate at 2 years.

Follow-Up Studies↗
PubMed1987

Abdominal computed tomography in teratoma of the testis: its accuracy in stage I disease and an assessment of the distribution of retroperitoneal lymph-node metastases in other stages of the disease.

One hundred and one patients with Stage I teratoma of the testis have had an abdomino-pelvic computed tomography (CT) scan. These patients have been followed up for a minimum of 18 months and only eight patients have relapsed in the abdomen alone. The abdomino-pelvic CT scan has a negative predictive value of 92%. In those shown by CT to have retroperitoneal lymphadenopathy, the distribution of disease correlates closely with that reported in the literature following retroperitoneal lymphadenectomy. The CT scan provides information about the amount of tumour present and this influences treatment. Computed tomography is the imaging modality of choice for staging patients with teratoma of the testis and invasive techniques do not appear to be justified.

Humans↗