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Biomedical subjects

M Booth

Publications and source records attributed to M Booth.

At least 55 records · Page 3Linked to original sources

Production of hemopoietic growth factors and gamma-interferon by large granular lymphocytes from patients with T gamma lymphocytosis.

Two patients with T gamma lymphocytosis in whom expanded large granular lymphocyte (LGL) populations were detected in peripheral blood and bone marrow are described. The surface antigen phenotypes of the LGL from these patients were similar with a major portion of cells carrying T3, T8, T11 and Leu7 markers. However, whereas fresh LGL from both patients demonstrated antibody-dependent cell cytotoxicity (ADCC), natural killer (NK) cell function was present in one case but absent in the other. Supernatants from enriched suspensions of the LGL unstimulated by exogenous antigen or mitogens were shown to contain significant amounts of hemopoietic growth factors colony-stimulating activity (CSA) and burst-promoting activity (BPA). In one case gamma-interferon was also detected. This study contributes to the accumulating evidence that LGL are able to generate factors which have the capacity to influence the proliferation of hemopoietic progenitor cells in vitro.

Colony-Forming Units Assay

Further assessment of the effects of occupational radiation exposure in the United Kingdom Atomic Energy Authority mortality study.

The United Kingdom Atomic Energy Authority mortality study was designed to investigate the relation between exposure to ionising radiation and mortality among the authority's employees. The present paper describes some of the problems encountered in assessing occupational exposure to low dose radiation and examines whether the study's conclusions about the relation between exposure and mortality could be affected by the methods used. The study covered the years 1946 to 1979 during which time the frequency with which personal film dosimeters were issued changed from weekly to monthly, and the threshold level below which measurements were not made decreased 20-fold. Exposure from "below threshold" readings made an important contribution to total exposure in the early years. Estimates, based on the remeasurement of a sample of old films, indicated that the average whole body exposure before 1961 may have been about double that which was measured. Furthermore, although records were kept of when dosimeters were lost or damaged, the associated exposures were unknown and could only be estimated. Workers whose dosimeter readings were missing for more than 5% of the time during which they were monitored had higher all cause mortality (p = 0.04) and higher mortality from accidents and violence (p = 0.05) than other radiation workers. The results of analyses of mortality in relation to whole body exposure were compared when the exposures included estimates of the below threshold and missing exposures and when these exposures were assumed to be zero. Some of the findings differed, but none changed sufficiently to alter the general conclusions. Although the trend in mortality from all cancers changed from one in which the increase with exposure was far from statistically significant (p = 0.3) when the below threshold and missing values were assumed to be zero to one that approached significance (p = 0.06) after they were estimated, calculations of the annual excess deaths from cancer per unit dose resulted in broadly similar estimates. Studies of workers exposed to ionising radiation usually focus on mortality in relation to whole body exposure. In the present paper its relation to neutron and surface exposure is also examined. Workers with measured neutron exposures had significantly lower all cause mortality than other workers with a radiation record (p = 0.03). Surface exposure was significantly related to mortality from all cancers (p = 0.02) and prostatic cancer (p less than 0.001). Some data on cancer registration are presented but these cannot be readily interpreted because cancer registration details were available only for ex-employees who may not be typical of the workforce as a whole.

Humans

Enrichment of progenitor cells from human marrow.

Suspensions enriched for myeloid and erythroid colony-forming cells were prepared from human marrow by simultaneous treatment of low-density cells with the monoclonal antibodies Campath-1 and 80H.3, followed by immune-rosetting; lymphocytes and monocytes were successfully removed by this method. The final suspension contained 22% of blasts and 70% primitive myeloid-monocytic cells. GM-CFCs, counted after 14 days of culture, were enriched 21-fold. Of all cells present in the final suspension, 10.8% were day 8 GM cluster-forming cells, 2.3% were day 8 GM colony-forming cells, 2.4% were day 7 CFU-E, 0.9% were day 14 GM cluster-forming cells, 1.1% were day 14 GM colony-forming cells, and 0.6% were day 14 BFU-E. After enrichment, BFU-E became markedly more dependent on the addition of 5637-conditioned medium as a source of growth factors, suggesting that lymphocytes and/or monocytes support erythroid progenitor growth in cultures of unfractionated marrow. By removing these cells, we obtained a sensitive assay for burst-promoting activities in conditioned media. This procedure can be used to study the roles of marrow lymphocytes and monocytes in hemopoiesis as well as providing a basis for the purification of normal and aberrant progenitors.

Bone Marrow Cells

Collection and validation of data in the United Kingdom Atomic Energy Authority mortality study.

The United Kingdom Atomic Energy Authority mortality study investigated the relation between mortality and recorded exposure to ionising radiation among employees working at the authority's seven establishments between 1946 and 1979. This report examines the design of the study and methods of data collection and validation. The completeness of the study population was deemed to be unsatisfactory at two establishments, where records of employment before 1965 had been destroyed. Assessment of the magnitude of the deficit led to the conclusion that the data from these establishments were too incomplete for inclusion in the mortality analysis. At the other establishments validation showed that the data collected were accurate and unbiased. Certain characteristics of the 39 546 employees included in the mortality analysis were identified which were relevant in interpreting the findings.

Data Collection

Mortality of employees of the United Kingdom Atomic Energy Authority, 1946-1979.

An analysis was conducted of 3373 deaths among 39 546 people employed by the United Kingdom Atomic Energy Authority between 1946 and 1979, the population having been followed up for an average of 16 years. Overall the death rates were below those prevailing in England and Wales but consistent with those expected in a normal workforce. At ages 15-74 years the standardised mortality ratios (SMRs) were 74 for deaths from all causes and 79 for deaths from all cancers. Mortality from only four causes was above the national average--namely, testicular cancer (SMR 153; 10 deaths), leukaemia (SMR 123; 35 deaths), thyroid cancer (SMR 122; three deaths), non-Hodgkin's lymphoma (SMR 107; 20 deaths)--but in none was the increase significant at the 5% level. Half of the authority's employees were recorded as having been monitored for exposure to radiation, their collective recorded exposure being 660 Sv (65 954 rem). Among these prostatic cancer was the only condition with a clearly increased mortality in relation to exposure. Of the 19 men who had a radiation record and died from prostatic cancer at ages 15-74 years, nine had been monitored for several different sources of exposure to radiation. The standardised mortality ratios were 889 (six deaths) in employees monitored for contamination by tritium, 254 (nine deaths) in those monitored for contamination by other radionuclides, and 385 (nine deaths) in those with dosimeter readings totalling more than 50 mSv (5 rem); but the same nine subjects tended to account for each of these significantly raised ratios. Because multiple exposures were common and other relevant information was not available the reason for the increased mortality from prostatic cancer in this population could not be determined and requires further investigation. Excess mortality rates of 2.2 and 12.5 deaths per million person years per 10 mSv (1 rem) were estimated for leukaemia and all cancers, respectively. The confidence limits around these estimates were wide, included zero, and made it unlikely that the International Commission on Radiological Protection's cancer risk coefficients were underestimated by more than 15-fold. Thus despite this being the largest British workforce whose mortality has been reported in relation to low level ionising radiation exposure, even larger populations will need to be followed up over longer periods before narrower ranges of risk estimates can be derived.

Adolescent

Management of adenocarcinoma in a columnar-lined esophagus.

Of 89 patients diagnosed between 1973 and 1983 as having at least 3 cm of columnar-lined esophagus, 22 were found to have adenocarcinoma. There was no difference in sex ratio, smoking, or the use of alcohol between the benign and adenocarcinoma groups. The patients with adenocarcinoma were older (63 years versus 57 years) and had a higher frequency of dysphagia (64% versus 46%), gastrointestinal bleeding (36% versus 24%), extended columnar-lined esophagus (94% versus 28%), and epithelial dysplasia (68% versus 10%). Heartburn was less frequent in the adenocarcinoma group (59% versus 79%), but when it occurred, it was of longer duration (mean, 18.8 years versus 10.9 years). In 2 patients, progression from benign columnar-lined esophagus to early adenocarcinoma was observed. Of the patients with adenocarcinoma, 2 received palliative treatment without resection and died four and nine months later. Six underwent partial esophagogastrectomy with 1 postoperative death. Four had residual columnar-lined esophagus at the resection margins. In one of them, stricture developed and in one, anastomotic recurrence of adenocarcinoma; 1-year survival was 50%. Fourteen patients underwent total thoracic esophagectomy with no operative deaths, strictures, or anastomotic recurrences; 1-year survival was 5 of 6. Surgical staging revealed that 63% had transmural spread and 55%, lymph node involvement.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma

Pregnancy after cytotoxic chemotherapy for gestational trophoblastic tumours.

To examine the possibility that cytotoxic drugs may cause sterility or congenital malformations in the offspring of women of childbearing age who are cured of cancer a study was conducted of the obstetric histories of 445 long term survivors treated in this unit with chemotherapy for gestational trophoblastic tumours between 1958 and 1978. After completing treatment 97% of those who wished for a pregnancy (49% of all women studied) conceived and 86% had at least one live birth. All these women had received methotrexate. Of the 47 women who wished to conceive and whose combination therapy included cyclophosphamide, 37 (79%) had a live birth. Women who received three or more drugs were less likely to have a live birth than those who received methotrexate alone or with only one other drug (p less than 0.001). There was no statistically significant excess of congenital malformations. These results are strong evidence that the cytotoxic drug regimens used in this unit for treating gestational trophoblastic tumours are compatible with the preservation of fertility in most women and not associated with any increase in congenital abnormalities.

Abnormalities, Drug-Induced

No increase in second tumors after cytotoxic chemotherapy for gestational trophoblastic tumors.

We investigated the incidence of second tumors after cytotoxic chemotherapy in 457 long-term survivors treated for choriocarcinoma or an invasive mole between 1958 and 1978. Treatment was given according to regular intermittent schedules and over a mean period of four months, with no maintenance. Methotrexate was given to all but two patients, and 261 (57 per cent) also received other cytotoxic drugs, most commonly dactinomycin, vincristine, cyclophosphamide, mercaptopurine, and 6-azauridine. After a mean period of 7.8 years since the beginning of treatment and a total of 3522 patient-years of risk, second neoplasms had developed in only two women (acute leukemia in one and carcinoma of the breast in the other). This figure is less than the number of cases of cancer that would have been expected (3.5) in this group and suggests that the use of methotrexate as chemotherapy for choriocarcinoma is not carcinogenic in the medium term.

Adult

Side effects of danazol compared with an ethinyloestradiol/norgestrel combination when used for postcoital contraception.

A postcoital contraceptive with a lower incidence of nausea and vomiting than oestrogen-progestogen combinations would be a significant advance. During a nine-month period, 101 women were treated at the Margaret Pyke Centre in London with either an oestrogen-progestogen combination or with danazol. A comparison of the side effects of each drug is reported. Those treated with danazol were six times less likely to experience nausea and none vomited. With the exception of breast symptoms, other side effects were five times less common in women receiving danazol. These differences give danazol a clear advantage in terms of patient acceptability. Further experience will enable the efficacy of danazol to be evaluated and so determine whether this drug should become the preferred hormonal postcoital treatment.

Adult

Tetracosactrin for the management of asthmatic patients after long-term corticosteroids.

Thirty-five of 41 asthmatic patients, who had been taking oral corticosteroids regularly for between one and 12 years, recovered their adrenal function after courses of depot tetracosactrin, even those with apparently complete adrenal suppression. They all showed benefit by transfer to depot tetracosactrin, though steroid withdrawal symptoms could be troublesome. Skin pigmentation in three, and two severe reactions to tetracosactrin were encountered. We believe that it is advisable to give depot tetracosactrin when converting severe asthmatics to the use of beclomethasone dipropionate aerosols who have previously been treated by long-term steroids with consequent adrenal suppression.

Adolescent