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Biomedical subjects

R L Prentice

Publications and source records attributed to R L Prentice.

At least 73 records · Page 4Linked to original sources
PubMed1983

Marrow transplantation from HLA-identical siblings for treatment of aplastic anemia: is exposure to marrow donor blood products 24 hours before high-dose cyclophosphamide needed for successful engraftment?

The present study in patients with aplastic anemia was undertaken to determine whether exposure of recipients to donor blood products 24 hr before preparation with cyclophosphamide (1) enhanced the rate of sustained engraftment of marrow from HLA-identical siblings as suggested by animal experiments, (2) increased the rejection rate, in particular in transfused patients who may already have been exposed to donor antigens by blood products, or (3) was of no relevance to the outcome of transplantation of marrow from HLA-identical siblings. One-hundred fifty-five patients were studied, of whom 78 received blood products from the marrow donor 24 hr before cyclophosphamide and 77 did not. A binary logistic regression analysis was applied to the data, simultaneously considering five previously known risk factors for rejection. Results showed that preceding transfusion of donor blood products had neither a significant beneficial nor detrimental effect on the incidence of sustained engraftment.

Anemia, Aplastic↗
PubMed1983

Relationship of cigarette smoking and radiation exposure to cancer mortality in Hiroshima and Nagasaki.

Cancer mortality among 40,498 Hiroshima and Nagasaki residents was examined in relation to cigarette smoking habits and estimated atomic bomb radiation exposure level. Relative risk (RR) models that are either multiplicative or additive in the two exposures were emphasized. Most analyses were directed toward all nonhematologic (ANH) cancer, stomach cancer, lung cancer, or digestive tract cancer other than stomach cancer, for which there were, respectively, 1,725, 658, 281, and 338 deaths in the follow-up period for this study. Persons heavily exposed to both cigarette smoke and radiation were found to have significantly lower cancer mortality than multiplicative RR models would suggest for ANH cancer, stomach cancer, and digestive tract cancer other than stomach cancer. Surprisingly, the RR function appeared not only to be submultiplicative for some of these cancer site categories but also may be subadditive. The lung cancer RR function could not be distinguished from either a multiplicative or an additive form. The number of deaths was sufficient to permit some more detailed study of ANH cancer mortality: RR functions appeared to be consistent between males and females, though a paucity of heavy smoking females limits the precision of this comparison. The submultiplicative nature of the RR function mentioned above was particularly pronounced among persons who were relatively young (less than or equal to 30 yr of age) at the time of radiation exposure. The RR function for these younger subjects depends strongly on both radiation and cigarette smoke exposure levels. Even light smoking (approximately 5 cigarettes/day) for an extended period of time was associated with a large estimated RR. Implications of these findings are discussed in relation to human carcinogenesis models. As a byproduct, cancer mortality of several sites is significantly related to radiation exposure in this population, after accommodation for the possible confounding effects of cigarette smoking.

Adult↗
PubMed1983

Investigation of circular asymmetry in cancer mortality of Hiroshima and Nagasaki A-bomb survivors.

Data on Hiroshima and Nagasaki A-bomb survivors are used to investigate, for each city, possible circular asymmetry in cancer mortality around the hypocenter. Using the Cox regression method and controlling for age ATB, sex, followup year, distance from the hypocenter, and type of shielding, it is found that in Hiroshima cancer mortality was significantly higher in the westerly direction from the hypocenter. Mortality from stomach cancer, leukemia, and colon cancer were higher in the westerly direction. In Nagasaki, only lung cancer exhibited circular asymmetry, and was significantly higher in the westerly direction. For various reasons, the results tend to support the possibility of an asymmetry in radiation dose in Hiroshima, but not in Nagasaki. Also, possible asymmetry in nondose variables associated with cancer is suggested in both cities, particularly in variables associated with lung cancer. Indications for future work and implications for future dose-mortality investigations are discussed.

Age Factors↗
PubMed1982

Leukocyte counts and cerebrovascular disease.

Elevated total leukocyte count in a biennial examination period is shown to be a significant (p = 0.001) predictor of cerebral infarction (CI) incidence in the subsequent 2 yr examination period, in a large Japanese cohort study. This association is not explainable on the basis of corresponding age, sex or blood pressure levels. The extent to which the association might be attributable to cigarette smoking habits could not be thoroughly examined with available data. Relative risks associated with a specific elevated leukocyte count may be larger among persons less than 65 yr of age than among older persons. When counts of specific leukocyte cell lines are considered a significant (p = 0.0006) role for neutrophil count emerges, while an additional predictive role for other leukocyte cell types could not be detected. In contrast, there is a suggestion that cerebral hemorrhage (CH) risk may be lower following an elevated leukocyte count. In particular, a negative association between lymphocyte count and CH incidence in the subsequent biennial examination cycle, is nearly significant (p = 0.07), in spite of a rather small number of CH cases in the sample.

Adult↗
PubMed1982

Serial blood pressure measurements and cardiovascular disease in a Japanese cohort.

A cohort of 16,711 residents of Hiroshima and Nagasaki have participated in a program of biennial clinical examination and history taking that began in 1958. During 1958-1974, a total of 621 confirmed cases of cerebrovascular disease and 218 confirmed cases of coronary heart disease were incident. This study makes a detailed examination of the relationship between a series of biennial examination blood pressure (BP) measurements and cardiovascular disease risk. Two aspects are emphasized: the quantitative relationship between risk and both systolic blood pressure (SBP) and diastolic blood pressure (DBP), and the predictive value of BP levels some years in the past, given more recent BP determinations. Cerebral hemorrhage incidence is shown to depend markedly on recent DBP level, while earlier DBP levels make an additional important contribution to risk prediction. Corresponding SBP levels have little additional predictive value. With cerebral infarction, SBP is the more important predictor, though elevated DBP conveys some additional risk at high SBP levels. Recent BP levels are more strongly predictive for cerebral infarction than are BP levels some years earlier. Elevated SBP is also an important predictor of coronary heart disease risk in this population, while elevated DBP does not appear to be predictive at specified SBP. SBP levels several years in the past are more closely associated with coronary heart disease risk than are recent SBP readings. The dependence of BP relative risk functions on sex and age is examined and some departures from the results just listed are noted at younger ages. Implications for disease mechanism and hypertensive therapy are discussed.

Adult↗
PubMed1982

Leukocyte counts and coronary heart disease in a Japanese cohort.

Coronary heart disease incidence during 1958-1974, in a cohort of Hiroshima and Nagasaki residents, was found to relate significantly (p = 0.01) to total leukocyte count, taken an average of two years earlier. Relative risks, as a function of leukocyte count, did not appear to depend on sex or cigarette smoking status, but may be larger for subjects less than 65 years of age than for older persons. This study examines, for the first time, differential leukocyte counts and percentages in relation to coronary heart disease incidence. Both neutrophil count and eosinophil count significantly relate to coronary heart disease incidence, while there is also a suggestion for a relationship with monocyte count. A possible immunopathologic basis for such associations is mentioned. It will be important for other studies to confirm these relationships, however, as the present data do not allow one to clearly show the relative risk, at a specified total leukocyte count, to depend on the differential leukocyte fractions. Available data also leave uncertainty concerning the "independence" of leukocyte counts in the specification of coronary heart disease risk, relative to such known risk factors as cigarette smoking habits and serum cholesterol levels.

Adult↗
PubMed1982

Radiation exposure and thyroid cancer incidence among Hiroshima and Nagasaki residents.

The dependence of thyroid cancer incidence on radiation exposure level is examined with the use of tumor registry follow-up data on a life-span cohort of 98,610 Hiroshima and Nagasaki residents. The sample includes 112 clinically evident thyroid cancer cases: 62 in Hiroshima and 50 in Nagasaki. A clear, predominantly linear, increase in thyroid cancer incidence corresponds to increasing levels of gamma radiation to the thyroid gland, whereas neutron exposure could not be shown to contribute further to thyroid cancer risk. The relative risk associated with gamma ray exposure is particularly high among persons who were less than 30 years old at the time of radiation exposure. Limitations on the incidence and dosimetry data are discussed, as well as the ability of the Cox regression method to accommodate some of these limitations.

Aged↗
PubMed1981

Sideroblastic anaemia in association with malignant histiocytosis.

A 69-year-old women died of malignant histiocytosis in association with sideroblastic anaemia. Respiratory insufficiency was a prominent clinical feature and was found to be due to obstruction of pulmonary capillaries by malignant histiocytes. It is possible that the same abnormal myeloid clone gave rise to malignant histiocytosis and sideroblastic anaemia.

Aged↗
PubMed1981

Endometrial carcinoma: histopathology, survival, and exogenous estrogens.

Pathologic material was reviewed and survival data were obtained on 182 of the endometrial cancer patients reported in our previous study (1975) to compare histopathologic characteristics and clinical behavior (survival) between endometrial adenocarcinoma in estrogen users and nonusers. In addition, relative risk estimates of estrogen-associated endometrial carcinoma were calculated from review results. This work identifies estrogen users as having a significant higher frequency of low-grade tumor with an associated improved survival even when numerous clinical parameters are taken into account. Other histologic or clinical characteristics of the disease did not relate significantly to estrogen use after taking account of histologic grade. The marked increase in endometrial cancer risk among estrogen users was confirmed by the pathology review (relative risk 6.44) and is evident even when attention is restricted to disease that has invaded the myometrium (relative risk 6.09).

Adenocarcinoma↗
PubMed1980

Varicella-zoster virus infection after marrow transplantation for aplastic anemia or leukemia.

Nearly one-half of marrow transplant recipients who survive at least 6 months develop varicella-zoster virus (VZV) infection. Of 92 cases studied, 82 occurred within the first 12 months after transplant. Only one patient had recurrent infection. Seventy-seven patients had herpes zoster, 22 with subsequent cutaneous dissemination, and 15 had varicella. The overall mortality rate was 8%, and all deaths occurred within 9 months of transplant. Twenty-six of 32 patients studied had significant rises in VZV antibody during recovery. Among patients with acute leukemia, those with syngeneic transplants had a significantly lower incidence of VZV infection than those with allogeneic transplants. Incidence was slightly, but not significantly, decreased among patients with aplastic anemia. In contrast to other infections, the incidence of VZV infection was not influenced by graft-versus-host disease or predicted by the results of dinitrochlorobenzene skin testing.

Adolescent↗
PubMed1980

Analysis of cytotoxic effector cell function in patients with leukemia or aplastic anemia before and after marrow transplantation.

Cytotoxic effector cells mediating natural killing (NK), antibody-dependent cellular cytotoxicity (ADCC), and lectin-dependent cellular cytotoxicity (LDCC) were studied in patients with leukemia or aplastic anemia before and/or after marrow transplantation. Before transplantation, about one-third to one-half of the patients were deficient in cytotoxic activity. In patients with leukemia, this was most likely due to large numbers of circulating blast cells diluting or replacing the effector cells. In patients with aplastic anemia there was an apparent absence of the effector cells in a proportion of the patients. After marrow transplantation, cytotoxic activity in all three systems returned to normal rapidly, by 30 days, and remained so through 100 days. However, about 20% of patients studied beyond 1 year were deficient in these functions. There were no significant associations between cytotoxic activity and important clinical parameters including infections, graft-vs-host disease, and recurrence of leukemia. Our findings do not support an immunosurveillance role for NK against leukemia after marrow transplantation. Furthermore, they point out the need for new in vitro approaches for meaningful monitoring of marrow transplant patients. Finally, our results showed a significant discordance between NK, ADCC, and LDCC activities in these immunologically perturbed individuals, indicating that either different cell populations or different cellular mechanisms are involved in these cytotoxic functions.

Anemia, Aplastic↗
PubMed1980

A new definition of the nonstress test.

The nonstress portions of 42 abnormal oxytocin challenge tests (OCT) and 50 negative OCT tracings were redefined by 9 criteria in the literature. The results showed that the criteria of Trierweiler et al are the most predictive of fetal outcome but would lead to unnecessary OCTs in 46% of cases. However, the criteria of Trierweiler et al in combination with a new criteria modified from thos of Paul and Miller and Evertson et al are the most predictive and lead to unnecessary OCTs in only 14% of cases.

Female↗