Immunological unresponsiveness in leprosy

The various forms of leprosy form a clinical and immunological spectrum which offers extraordinary possibilities for insight into immunoregulatory mechanisms in man. At one pole, tuberculoid leprosy, patients develop high levels of cell-mediated immunity which ultimately results in killing of bacilli in the tissues, albeit often with damage to nerves. At the lepromatous pole, patients exhibit selective immunological unresponsiveness to antigens of M. leprae. Even though all currently known protein species of M. leprae and BCG are cross-reactive, lepromatous patients unreactive to M. leprae antigens frequently respond strongly to tuberculin. In vitro experiments suggest the existence of lepromin-induced suppressor activity, mediated by both monocytes and T cells. The T suppressor cells have the T8 phenotype of which 50% express the activation markers, Ia and FcR. The one unique species of antigen of the leprosy bacillus is a phenolic glycolipid, and it appears that the TS cells largely recognize the terminal trisaccharide of this unique antigen. Depletion of the TS cells restores in vitro reactivity of lymphocytes to lepromin in a portion of lepromatous patients, and addition of IL-2-containing supernatants partially restores responsiveness to M. leprae antigens. Vaccination of lepromatous patients with a mixture of M. leprae and live BCG restores cell-mediated immunity in the majority of lepromatous patients, and concomitantly reduces the in vitro suppressor activity and number of activated T8 cells. These experiments suggest the existence of stage-of-disease related suppressor cells in leprosy which appear to block the responsiveness of TH capable of responding to either specific or cross-reactive mycobacterial antigens. The mode of action of these TS appears to be the inhibition of production of IL-2 and other lymphokines. Successful immunotherapeutic vaccination appears to overcome this block in the majority of patients.

Viral infections of the nervous system

Neurotropic viruses cause a number of important infectious syndromes including encephalitis, myelitis, meningitis, and radiculopathy. In this review, the biology of conventional and unconventional viruses is examined. The host immune response to viruses is discussed, and patterns of viral pathogenesis are explained. The clinical features, laboratory findings, management of important viral infections, such as herpes simplex encephalitis and epidemic encephalitis, are presented. Post-infection syndromes, such as the Guillain-Barré syndrome, and chronic viral infections, such as those causing progressive multifocal leukoencephalopathy and subacute sclerosing panencephalitis, are discussed. Current knowledge concerning the nature of unconventional virus-like agents of the spongiform encephalopathies, including kuru and Creutzfeldt-Jakob disease, is summarized. Finally, viral infections of immunocompromised patients and the possible role of viruses in the newly described acquired immunodeficiency syndrome (AIDS) are examined.

Social factors, diet and breast cancer in a northern Italian population

The relation of breast cancer to social and dietary variables was evaluated in a case-control study of 368 women with breast cancer admitted to the General Hospital of Pordenone (a town in the eastern side of Northern Italy) and 373 age-matched controls. Occupation was related to the risk of breast cancer, housewives and non-manual workers (teachers and other professionals, clerical workers, etc.) showing relative risks of 1.7 and 2.4 respectively when compared to women occupied in agriculture. The role of education was apparently less important, and not statistically significant. The risk was higher in women who were obese, the trend of increasing risk with increasing body mass index being confined to post-menopausal women. When indicators of dietary fat intake were analysed, a significantly increased risk was found with more frequent consumption of milk and dairy products but the risk estimates were only slightly above unity with reference to meat consumption. Women who drank alcoholic beverages showed a relative risk of 2.5 compared to women who had never drunk, when allowance was made for all identified potential confounding factors. The association between alcohol and breast cancer was not explained by the other dietary variables considered, and the risk estimates were higher for women who drank more wine, or more than one type of alcoholic beverage. Thus, the findings of the present study give evidence in favour of the hypothesis that alcohol consumption is related to the risk of breast cancer.

Oral contraceptives and benign breast disease: a case-control study

The relationship between benign breast disease and use of oral contraceptives was analyzed in a case-control study conducted in Milan with 288 cases of clinically relevant and histologically confirmed benign breast disease and 285 age-matched controls with a spectrum of acute conditions apparently unrelated to use of oral contraceptives. Compared to the risk for women who had never used oral contraceptives, the relative risk for users was 1.0 (95% confidence interval: 0.6 to 1.5). There was no significant association with duration of use; however, a significantly lower relative risk was found in women using oral contraceptives during the year before breast biopsy (relative risk: 0.4; 95% confidence interval: 0.2 to 0.8). The protection in current users increased with increasing duration of use. In spite of this finding, the overall results of the present study do not support the hypothesis that oral contraceptive use protects against development of histologically confirmed and clinically relevant benign breast disease.

Legal abortion and placenta previa

Legal abortion has been postulated to be a risk factor for placenta previa in subsequent pregnancies. To examine this hypothesis, we analyzed the deliveries of 28,665 women. We identified 68 women who had had placenta previa and compared their obstetric histories with those of 68 controls randomly selected from the same group of deliveries. The crude risk ratio for women with a history of one or more legal abortions was 1.4 (95% confidence interval, 0.5 to 3.6; p greater than 0.05). Standardizing the crude risk ratio for the effects of age and gravidity reduced the risk ratio to 1.1 (95% confidence interval, 0.4 to 2.8). In this predominantly black population legal abortion does not appear to have a significant association with placenta previa in subsequent pregnancies.

Bordetella pertussis whole cell vaccines--efficacy and toxicity

The literature concerning efficacy and side effects of pertussis vaccines is reviewed. With few exceptions, most vaccines induce a protective immunity lasting for 2 to 5 years. The large-scale use of pertussis vaccines has markedly contributed to the decrease in pertussis morbidity in small children but in some countries the incidence has increased in older children. Not even countries with immunisation rates of 90-95% have managed to eradicate pertussis or prevent disease in infants below the age of immunisation. The pertussis-associated mortality is currently very low in the industrialised countries and no differences can be discerned when countries with high, low and zero immunisation rates are compared. Local and benign systemic reactions are commonly seen after immunisation. The vaccines also sometimes cause convulsions, a shock-like state and, rarely, serious neurological reactions.

The prevalence of nuclear, cortical, and posterior subcapsular lens opacities in a general population sample

Data from the 1973 to 1975 Framingham Eye Study were used to estimate the prevalence rates of nuclear, cortical, and posterior subcapsular lens opacities in persons between ages 52 and 85 years. The rates for each of the opacities increased rapidly with age, so that for the oldest age group, 75 years and over, nuclear, cortical, and posterior subcapsular opacities were found in 65.5%, 27.7% and 19.7% of persons, respectively. Nuclear opacities were the most commonly diagnosed lens change. Each of the opacities was found more often in women than in men. Among persons with senile lens changes, the proportion with more than one type of change increased from 26.5% for ages 52 to 64 years, to 47.1% for ages 75 to 85 years. The high prevalence rates for senile lens opacities (over 75% for persons aged 75 to 85 years) and the frequent occurrence of opacities in combination create methodological problems for epidemiologic studies of lens opacities.

Exogenous estrogen and breast cancer after bilateral oophorectomy

Estrogen use in 119 women in whom breast cancer developed after surgically induced menopause was compared to use among an equal number of controls matched for age, date of bilateral oophorectomy, and duration of follow-up. No increased risk for estrogen use versus no use was evident (relative risk = 0.7). When the authors examined three measures of estrogen dose--number of chart notations of estrogen use, time since first use, and duration between first and last use--only those with greater than or equal to 5 notations had any significantly elevated risk (relative risk = 2.1; confidence limits 1.2-3.6), and there was a significant trend toward increasing risk with more notations (P = 0.03). Use specifically of conjugated estrogens was also associated with an increasing risk with more notation of estrogen use (P = 0.07). However, the other two measures of dose did not confirm this trend. Matched multiple logistic analysis suggested that number of notations of estrogen use conferred increased breast cancer risk (relative risk = 1.7), in dose-response relationships, but this result could have occurred by chance. Because of a lack of consistency, the generally low and statistically nonsignificant relative risks, and the lack of consistent effect modification in high-risk groups, the authors were unable to demonstrate a clear increased risk of breast cancer associated with replacement estrogen use.

Childhood nonovarian female genital tract cancers in Britain, 1962-1978. Descriptive epidemiology and long-term survival

The files of the Childhood Cancer Research Group ( CCRG ) and of the Oxford Survey of Childhood Cancers ( OSCC ) were scrutinized for all malignant genital neoplasms other than ovarian tumor registered in England, Scotland, and Wales in the period 1962 to 1978. After a review of the records and of the available pathologic reports, a total of 55 cases were confirmed, indicating an average incidence of about 0.5 cases per million female children per year, with no obvious trend over the study period. These included 9 (16.4%) cases originating from the vulva, 28 (50.9%) from the vagina, 3 (5.5%) from the cervix, 12 (21.8%) from the corpus uteri, and also 3 (5.5%) cancers of unspecified pelvic sites. A total of 45 (81.8%) cases were sarcomas, most frequently of the botryoid type, 7 (11.7%) were carcinomas, and 3 (5.5%) were germ cell neoplasms. Fifteen cases (27.3%) occurred in children younger than 1 year of age, and incidence showed a declining trend over age. Long-term survival was more common in tumors of the external genitalia, vagina, or cervix, and significantly better in carcinomas (100%) than in germ cell neoplasms (67%), or sarcomas (34%). A significant improvement in survival was noted over the period of time considered (5-year survival rates were 23% in the cases diagnosed in the 1960s, but 52% for those diagnosed in the 1970s), suggesting that a more rational integrated therapeutic approach may appreciably improve the prognosis of these rare neoplasms.

Sporadic Legionnaires' disease: clinical observations on 87 nosocomial and community-acquired cases

To add information about sporadic Legionnaires' disease, 87 cases of L. pneumophila pneumonia were reviewed. Twenty cases were nosocomial infections and 67 cases were community-acquired. Most cases (64%) occurred between July and October. The mean age of patients was 51.4 years and males outnumbered females 2.5:1.0. Thirty-one percent of patients were receiving corticosteroid, immunosuppressive, or antineoplastic chemotherapy when illness began. Immunosuppression at onset of illness was more common in nosocomial infections (90%) than in community-acquired infections (14%). Seventy percent of patients had underlying diseases. Malignancies, renal failure, and transplantation were the most common conditions underlying nosocomial infections. Chronic lung disease and malignancies were the most common diseases underlying community-acquired infections. The case-fatality rate in nosocomial infection (70%) was greater than that in community-acquired disease (22%). Clinical, laboratory, and radiologic features of the cases were examined. Illness ranged from mild to severe. Extrapulmonary findings of encephalopathy and renal failure were more common in fatal than in non-fatal cases. Indirect immunofluorescent and microagglutination antibody responses plateaued by the fourth week of illness. Twenty-nine patients died. The case-fatality rate of patients receiving erythromycin (6%) was less than that of patients receiving penicillin (36%), ampicillin (28%), cephalosporin (32%), or aminoglycosides (41%). Despite erythromycin therapy, the case fatality rate for nosocomial L. pneumophilia pneumonia was unacceptably high (25%).

Systematic investigation of enrichment media for wild-type Campylobacter jejuni strains

Of the media examined, thioglycolate broth supplemented with 5% lysed sheep blood, Butzler antibiotic mixture, and 0.1% lauryl sulfate was the most sensitive enrichment medium for recovery of wild-type strains of Campylobacter jejuni from cecal contents of chickens and chicken livers. It allowed the retrieval of 1 CFU as did solid media but permitted the screening of 50-times larger volumes. Double-strength enrichment medium required 5 to 10 CFU for growth. Omission of lauryl sulfate reduced the sensitivity. Replacement of Butzler antibiotic mixture with Blaser antibiotic mixture increased overgrowth and, therefore, decreased retrieval of C. jejuni.

Nonmedical costs to patients and their families associated with outpatient chemotherapy

One hundred thirty-nine patients receiving outpatient chemotherapy kept diaries of nonmedical expenses resulting from their disease and its treatment. Diaries were kept for both treatment and nontreatment weeks. Results showed that the mean cost to patients and their families for treatment weeks was $72.81, and for nontreatment weeks it was $45.88. Approximately 45% of these costs were out-of-pocket expenses, and 55% were wages lost. Transportation and food were the largest out-of-pocket expenses. Patients living at greater distance from treatment had higher out-of-pocket costs, and younger patients reported more wages lost. Fourteen percent of the patients were estimated to be spending more than 50% of their weekly incomes on nonmedical expenses, and these patients were found largely in the lower-income categories. A method is proposed for using these data to estimate total nonmedical expenses for different treatment regimens, and also for estimating cancer patients' total nonmedical costs nationally.

Subacute and chronic action of acrylonitrile on adrenals and gastrointestinal tract: biochemical, functional and ultrastructural studies in the rat

A single dose of acrylonitrile can produce fatal adrenal apoplexy within approximately 2 h. Our previous studies also indicate that multiple injections of the chemical cause acute hemorrhagic and occasional nonperforating duodenal ulcers. Other authors have reported increase in gut and lung neoplasia after chronic exposure. The present study was designed to elucidate the subacute and chronic actions of acrylonitrile on the adrenals, stomach and duodenum by correlating biochemical, functional and morphologic investigations, as well as to gain insight into the mechanisms of action of acrylonitrile. Rats were exposed to 0, 0.0001% (1 ppm), 0.002%, 0.01%, 0.05% or 0.2% acrylonitrile in drinking water, or to the same amount of the chemical given through daily gavage, for 7, 21 or 60 days. Acrylonitrile caused a time- and dose-dependent decrease in plasma corticosterone levels; aldosterone was affected only by the 'high' dose and prolonged time of exposure. Young rats were more susceptible than adults to this action of acrylonitrile. The adrenal cortex, especially the zona fasciculata, was atrophic in rats that had ingested the nitrile through drinking water. At 0.05% and 0.2%, it also caused decreased food intake and body weight gain. The adrenals were enlarged with a hyperplastic zona fasciculata after daily doses of a bolus of acrylonitrile. Ingestion of the chemical did not interfere with compensatory enlargement of the adrenal gland following unilateral adrenalectomy. On the other hand, the ACTH-induced elevation of corticosterone plasma concentration was significantly attenuated by acrylonitrile in drinking water. Electron microscopy of the adrenal glands revealed no consistent changes in the steroid-producing cells. We thus postulate that accelerated turnover of circulating corticoids and/or interference with the secretion or action of ACTH may primarily be responsible for the decreased plasma levels of corticosterone and aldosterone in rats that ingest acrylonitrile. The mucosa in the stomach at the junction of the forestomach and glandular region of animals that had ingested acrylonitrile was hyperplastic. The corpus also showed regional mucosal hyperplasia with the appearance of 'cobble-stoning'. These changes were preceded and associated with an elevated concentration of non-protein sulfhydryls mostly in the mucosa of the glandular stomach. A similar, less prominent elevation also occurred in the proximal duodenum. These alterations may resemble the preneoplastic combination of elevated glutathione and focal hyperplasia described in the liver with hepatocarcinogens.(ABSTRACT TRUNCATED AT 400 WORDS)

Toxocara canis infection in dogs in Beersheba, Israel

In the desert city of Beersheba, Israel, a survey was made of the infection rate of Toxocara canis in dogs. 3.0% of dogs destroyed at the municipal dog pound had intestinal T. canis. 7% of faecal samples gathered from day care centres throughout the city were shown to contain T. canis eggs. This low rate of infection could possibly be explained by the hot, arid climatic conditions which may render eggs non-infective or by the sandy soil in the area that may cover faeces containing T. canis ova and make the eggs unavailable to other dogs.

Humoral immune response to Epstein-Barr virus antigens and immunoglobulin allotypes in African Burkitt lymphoma patients

We examined whether any immunoglobulin allotype was associated with an elevated risk of Burkitt's lymphoma because of the association between Burkitt's lymphoma and abnormalities of the immunoglobulin-bearing chromosomes. The distribution of Gm and Km phenotypes among 56 Burkitt lymphoma cases and 25 age-matched controls was unremarkable. Burkitt's lymphoma has also been associated with the Epstein-Barr virus, and we therefore sought a relationship between immunoglobulin allotypes and antibody response to the component antigens of the Epstein-Barr virus, VCA, EA-D, EA-R and EBNA. No immunoglobulin phenotype was associated with higher antibody titers against any antigen, but there appeared to be an interactive effect in which persons homozygous at both Gm and Km loci had elevated titers against several of the component antigens of the Epstein-Barr virus. This is the first report of an interactive effect between immunoglobulin allotypes and viruses. Antibody titers against antigens of the Epstein-Barr virus were higher in cases than in controls, as expected. However, female cases had significantly higher titers than male cases, a finding similar to that previously reported in healthy persons.

Detection, isolation, and continuous production of cytopathic retroviruses (HTLV-III) from patients with AIDS and pre-AIDS

A cell system was developed for the reproducible detection of human T-lymphotropic retroviruses (HTLV family) from patients with the acquired immunodeficiency syndrome (AIDS) or with signs or symptoms that frequently precede AIDS (pre-AIDS). The cells are specific clones from a permissive human neoplastic T-cell line. Some of the clones permanently grow and continuously produce large amounts of virus after infection with cytopathic (HTLV-III) variants of these viruses. One cytopathic effect of HTLV-III in this system is the arrangement of multiple nuclei in a characteristic ring formation in giant cells of the infected T-cell population. These structures can be used as an indicator to detect HTLV-III in clinical specimens. This system opens the way to the routine detection of HTLV-III and related cytopathic variants of HTLV in patients with AIDS or pre-AIDS and in healthy carriers, and it provides large amounts of virus for detailed molecular and immunological analyses.

Notification of workers at high risk: an emerging public health problem

During the last two decades, an increasing number of epidemiologic studies have found cohorts of workers to be at high risk of work-related chronic diseases, especially cancers. These studies frequently have led to the broad recognition of occupational hazards and eventually to the prevention of exposures to such hazards. Generally, however, the individual cohort members found to be at high risk have not been notified of study results, and programs of medical intervention or of palliative services directed at these individual workers have not been developed. Recently, the issue of whether or not workers have a right to be notified more directly about known health hazards to which they may have been exposed has emerged as a major, unresolved question in public health policy. Issues of concern include the criteria that should guide notifications; whom, when, and how to notify; and who should pay for notification and follow-up services. This commentary discusses the scientific, ethical, economic, and institutional aspects of worker notification, and describes three new demonstration projects that have provided notification and intervention for workers at high risk of bladder, colon, and lung cancer.

CVD mortality, 1968-1978: observations and implications

U.S. multiple cause of death data were examined for the period 1968-1978. Specifically, the role of cerebrovascular disease mortality as an underlying and associated cause of death was studied. The number of deaths where cerebrovascular disease was cited as the underlying cause of death declined much faster than the number of deaths where cerebrovascular disease was cited as the associated cause of death. This trend is indicative of a possible change in the role of cerebrovascular disease as an associated cause of death. Cause elimination life tables were constructed for cerebrovascular disease as the underlying cause of death and as any cause of death. In the general population, eliminating stroke as a cause of death is projected to have less impact in 1978 than in 1968, for men than for women, and for whites than for nonwhites. Tables were also constructed to examine the life expectancy gains for the group of individuals who died of cerebrovascular disease. For these individuals, the gain in life expectancy at birth ranges from 9 years for white males to 18 years for nonwhite females.

Increased estrogen-16 alpha-hydroxylase activity in women with breast and endometrial cancer

We have measured the three principal oxidative transformations of estradiol by means of a radiometric procedure in women with breast or endometrial cancer and in age matched controls. No difference between the 17 beta-ol oxidation or 2-hydroxylation of the hormone was observed between the study groups. In contrast, 16 alpha-hydroxylation was strikingly elevated in the women with breast and endometrial cancer relative to the age matched controls. Evidence is presented that this increased activity precedes the clinical evidence of the disease and that it represents a significant risk factor for these estrogen dependent tumors. This risk may be mediated by one of the products of 16 alpha-hydroxylation, 16 alpha-hydroxyestrone, which exhibits unique biological properties.

Epidemiology, genetics and sociology

In the course of this century man's control over his natural environment and its effects has vastly increased. As a result, death rates from many illnesses caused by environmental factors have fallen markedly. This is very evident in the field of infant mortality. In 1906–10, of every 1000 babies born alive in this country, 117 died before their first birthday. By 1971–75 this figure had dropped to less than 17.

Age at first birth and breast atypia

The relation between age at first birth and the occurrence of fibrocystic breast disease of different atypia subtypes was evaluated using data from a cohort study of the health effects of oral-contraceptive use. Multivariate case-control analysis was performed on 218 parous women with biopsied fibrocystic disease and 928 parous controls. Fibrocystic breast disease, as a whole and as atypia subtypes, was found to be unrelated to age at first birth. Furthermore, the estimated effect of age at first birth did not vary from one atypia subtype to another. Women with high parity were found to be at decreased risk of fibrocystic breast disease compared to those with low parity. Age at completion of education, used as an indicator of socioeconomic status, was found to be moderately associated with fibrocystic breast disease. The estimated effect of parity and age at completion of education also did not vary among subtypes. More epidemiologic studies specific to histopathologic classifications of benign breast disease are called for.

Clinical features and prognosis of Reye's syndrome

Twenty three sporadic cases of Reye's syndrome diagnosed according to widely accepted criteria were seen between 1979 and 1982. The patients were younger than those reported from North America (median age 9 months), girls were twice as common as boys, and the syndrome presented twice as frequently in the summer 6 months. The annual incidence was 1.4 cases/100 000 among children aged less than 4 years. The prodrome consisted of upper respiratory symptoms in 61% of the children and even less specific features in more than 25%; two patients had varicella. Six of the 23 patients presented after a prodrome of less than 24 hours with 'acute collapse', simulating 'near miss' cot death associated with profound hypoglycaemia, and in four of these there was an unfavourable outcome. Intensive care methods including judicious fluid restriction coupled with 'prophylactic' hyperventilation (87%), direct monitoring of intracranial pressure (70%), and barbiturate coma (52%) achieved neurologically intact survival in 74% of patients. Failure to recognise the syndrome early enough or to manage it appropriately resulted in four deaths. To help reduce overall mortality in the United Kingdom paediatricians have a duty to acquaint family doctors and emergency department staff of the earliest clinical features of Reye's syndrome and of the need for immediate hospital referral.

Class II HLA-DC beta-chain DNA restriction fragments differentiate among HLA-DR2 individuals in insulin-dependent diabetes and multiple sclerosis

HLA-DR2 allele is negatively associated with insulin-dependent diabetes and positively associated with multiple sclerosis (MS). A 2.2-kilobase-pair EcoRI DNA restriction fragment detected with a beta-chain HLA-DC cDNA probe was found to be strongly correlated with HLA-DR2 in the normal population, but was absent in HLA-DR2 insulin-dependent diabetic patients. This fragment was found in HLA-DR2 multiple sclerosis patients with the same frequency as in controls. A beta-chain HLA-DC 12-kilobase-pair BamHI fragment might differentiate multiple sclerosis patients from healthy individuals.

Ocular toxocariasis. A review

This review is an update on the subject of ocular toxocariasis. An introductory section is designed to familiarize the clinician with the epidemiology, characteristics of the organism, the life cycle in dogs and the systemic human disease known as visceral larval migrans ( VLM ). The more comprehensive second section considers the historical aspects of the ocular involvement, the clinical variations of ocular toxocariasis, pathology, differential diagnosis, diagnostic approaches, and treatment. Emphasis is placed upon new diagnostic techniques such as the enzyme-linked immunosorbent assay (ELISA) and cytologic diagnosis of intraocular aspirates. Newer therapeutic techniques such as vitrectomy are also considered. The review includes 200 references on systemic and ocular toxocariasis.

Predictors of stroke-associated mortality in the elderly

Although stroke is a major cause of death in older adults, few studies have examined the independent contribution of cardiovascular disease risk factors to stroke mortality in the geriatric age group. We report here a nine-year followup of a Southern California community of 2107 men and women aged 65 to 84 years. In this older cohort, age was the most significant independent risk factor for stroke-associated mortality in both sexes. Systolic blood pressure was weakly but significantly associated with stroke mortality in this older age group. Cigarette smoking was positively related and educational level of head of household negatively related to stroke mortality in both sexes, with the predominant effect in women. No significant independent effect of cholesterol, fasting plasma glucose or obesity was discernible. Both blood pressure and cigarette smoking are potentially remedial risk factors for stroke after age 65.

A case-control study of risk indicators among women with premenopausal and early postmenopausal breast cancer

Among 714 premenopausal and 130 postmenopausal breast cancer cases matched with 8440 controls for age in years and menopausal status, risk indicators for breast cancer were similar, although most associations were stronger in the premenopausal women. Compared with nulliparous women, the relative risk (RR) for those with first birth before age 25 years was 0.7 (95% confidence limits [CL] from 0.5 to 0.9) among premenopausal women, and 0.7 (0.4-1.4) for postmenopausal women. In the premenopausal cases, a history of breast cancer in a sister gave a RR of 3.0 (2.1-4.1) and in a mother 1.9 (1.4-2.5), whereas for the postmenopausal women the RRs were 1.4 (0.6-3.1) and 1.3 (0.6-2.6), respectively. Fibrocystic breast disease was also a significant predictor of subsequent breast cancer in the premenopausal and postmenopausal women. In relation to women having a single birth, premenopausal women with six or more births had a risk of breast cancer of 0.6 (0.4-1.0), which was present even after adjustment for age at first birth.

Acute viral hepatitis in Lebanon: evidence for a HAV-like non-A non-B hepatitis

Ninety-three cases of acute viral hepatitis in adult Lebanese patients were followed-up prospectively for a period ranging from 6 to 18 months. These included 33 hepatitis A (HAV), 32 hepatitis B (HBV) and 21 non-A, non-B hepatitis (NANB) cases. The clinical and seroepidemiologic characteristics of the three types were evaluated. HAV was characterized by a short prodroma (less than 1 week) and a high IgM level. HBV did not differ from similar cases reported in the Western world except for a complete absence of male homosexuals and drug addicts as a possible route of transmission. NANB hepatitis in Lebanon is mainly a sporadic infection similar to HAV except that the prodromal phase is prolonged (greater than 14 days) and IgM levels are within normal limits. The failure to develop chronicity in NANB suggests that the virus of sporadic NANB may be different from that which causes post-transfusional (PTH) NANB.

Fibroblasts from patients with hereditary cutaneous malignant melanoma are abnormally sensitive to the mutagenic effect of simulated sunlight and 4-nitroquinoline 1-oxide

Because of a possible etiologic link between mutations and carcinogenesis, we compared fibroblasts derived from skin biopsies of several patients with hereditary cutaneous malignant melanoma and the dysplastic nevus syndrome for sensitivity to the mutagenic and/or cytotoxic effect of broad-spectrum simulated sunlight and of a UV mimetic carcinogen, 4-nitroquinoline 1-oxide (4NQO). The genetic marker was resistance to 6-thioguanine; loss of colony-forming ability was the assay for cytotoxicity. All five strains tested were more sensitive than normal to the killing effect of 4NQO (slopes of survival curves were 2- to 3-fold steeper), but only one strain was hypersensitive to killing by Sun Lamp radiation. Two strains were tested for mutagenicity. The response of each to the mutagenic action of these agents corresponded to its response to cell killing. Both strains were hypermutable after exposure to 4NQO, but only one showed a higher than normal frequency of mutants induced by simulated sunlight. The finding that nonmalignant fibroblasts from patients with a hereditary variant of malignant melanoma are abnormally susceptible to carcinogen-induced mutations suggests that hypersensitivity to mutagens contributes to risk of melanoma in patients. It also supports the somatic cell mutation hypothesis for the origin of cancer.

The epidemiology of pertussis and pertussis immunization in the United Kingdom and the United States: a comparative study

Pertussis is a common serious illness of childhood that can be controlled by immunization. It is a unique disease in that it is clinically manifested more often in females than in males. In the 20th century the mortality from pertussis has decreased steadily in both the United Kingdom and the United States. This decline in death rate was well underway prior to the introduction of pertussis vaccine but was accelerated after vaccine use became widespread. In recent years the case fatality rate in the United States has been considerably greater than that in the United Kingdom. One obvious reason for this difference is the difference in age-specific attack rates in the two nations. Available data also suggest that recent pertussis deaths in infants in England and Wales may frequently be reported as due to respiratory diseases other than pertussis. Although it is frequently suggested by some observers, there is no evidence that the incidence of pertussis was declining prior to the widespread use of vaccine. All available evidence indicates that pertussis vaccine use in both the United Kingdom and the United States was responsible for a drastic reduction in the magnitude of both endemic and epidemic pertussis. Decreased utilization of pertussis vaccine in England and Wales beginning in 1975 resulted in two major epidemics of pertussis in 1977-1979 and 1982-1983. Moderate local and systemic reactions commonly occur following pertussis immunization. These reactions appear to be less common and less severe in the United Kingdom than in the United States, but in contrast to recent studies in the United States, there are no recent quantitative studies in the United Kingdom. There are virtually no data available in the United States on the incidence of serious neurologic disease resulting from pertussis immunization. In contrast, the recently published findings of the NCES, a case-control study of national scope, have allowed attributable risk estimates of serious neurologic disease to be made. Although the NCES was a carefully controlled study, its findings in regard to attributable risk were surprisingly similar to those of several other studies in which no allowance was made for background encephalopathy due to other causes.(ABSTRACT TRUNCATED AT 400 WORDS)

Diet and the epidemiology of human breast cancer

There are substantial data on breast tumorigenesis in animals that suggest that diet may be an important factor in human breast cancer etiology. The promotional effects of dietary fat, and, in particular, unsaturated fats, on mammary tumors in rodents is well established. The geographic distribution of breast cancer in humans correlates with international differences in average fat intake. Differences in dietary habits among populations in the United States and their breast cancer risk also have been observed. In the United States, the trend has been toward increased total fat consumption and increased use of polyunsaturated fats. However, breast cancer incidence among white women in the United States has changed very little. Case-control studies of dietary intake and breast cancer risk have shown inconsistent results, and prospective studies of breast cancer mortality and serum cholesterol and serum lipids show no differences in risk between women with high levels of cholesterol and serum lipids compared with women with low levels. Laboratory studies also suggest the possibility that natural inhibitors of breast cancer may occur in the diet as well. Antioxidants, inducers of microsomal enzyme activity, and retinoids, all have been implicated in the metabolic epidemiology of breast cancer. Research results at Roswell Park memorial Institute have associated lower levels of intake of dietary vitamin A with a slightly elevated risk of breast cancer. To date, the epidemiologic data do not indicate with confidence that any specific dietary risk factor may be associated with breast cancer risk in the United States population. Additional epidemiologic studies on inhibition or promotion of breast cancer following the leads of previous laboratory research may clarify the nature and practical significance of the relationship between diet and breast cancer.