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Biomedical subjects

F Davis

Publications and source records attributed to F Davis.

At least 37 records · Page 2Linked to original sources
PubMed1996

Ethnic variation in the incidence of stomach cancer in Illinois, 1986-1988.

Wide ethnic and geographic variation in stomach cancer incidence has been reported in Eastern and Western countries. Stomach cancer is reported to be the most common malignant neoplasm in Asia, specifically, China, Japan, and Korea. In contrast, stomach cancer incidence in the United States among Caucasians is low and among blacks, moderate to low. Only one other study has directly compared the rates of stomach cancer in the three ethnic groups (i.e., white, African American, and immigrant Korean) living in the same region. The authors extend their investigation by comparing the incidence rate of stomach cancer among the same three ethnic groups in the state of illinois from 1986 to 1988. In this study, the incidence of stomach cancer was observed to be lowest in whites, intermediate in African Americans, and highest in immigrant Koreans. The overall 3-year cumulative incidence rate from 1986 to 1988 was 62.6/100,000 (95% confidence interval (CI) 38.6-86.7), 28.2/100,000 (95% CI 25.7-31), and 22.5/100,000 (95% CI 21.5-23.5) for immigrant Koreans, African Americans, and whites, respectively. The 3-year age-adjusted cumulative incidence rate for immigrant Koreans (172/100,000) was approximately four-and eightfold higher than for African Americans (41/100,000) and whites (21/100,000). The incidence of stomach cancer increased as a function of age in both sexes. Although a higher rate was observed in males than in females, these rates were four-and eightfold higher in African Americans and immigrant Koreans, when compared with their white counterparts in both sexes. Despite a substantial reduction of stomach cancer incidence in the United States and other Western countries, it remains the most frequent malignancy in native and immigrant Koreans. The high rate of stomach cancer in immigrant Koreans compared with African Americans and white populations residing in Illinois indicates either a drastically disproportionate undercount of immigrant Koreans in the 1990 census or a profound genetic-environmental interaction.

Adolescent↗
PubMed1996

Applying the realized probability of dying to cancer survival.

Age comparisons of survival in cancer cohorts generally utilize relative survival rates, which are based on indicators of the probability of survival for a given number of years after diagnosis. Cancer relative survival rates for the same number of years tend to decline as age at diagnosis increases. However, the same number of years of survival reflects higher relative longevity at older ages than at younger ages. The realized probability of dying (RPD) is a survival measure that expresses individual survival time after diagnosis relative to the survival distribution of an age-, race-, and sex-specific reference population, in effect weighing individual survival time more heavily as age at diagnosis increases. The purpose of this study was to apply the RPD as a survival measure in cancer epidemiology. Two cohorts of cancer patients, white males with prostate cancer and white females with breast cancer, aged 55 years and over at diagnosis, were followed for 15 years. Although older subjects survived less time after diagnosis than younger subjects, they achieved more favorable RPD values. We present survival analysis methods for analyzing the RPD in this population, an approach not previously used with this measure. The implications for use of the RPD in cancer epidemiology are discussed.

Breast Neoplasms↗
PubMed1996

Cocaine and cigarettes: a comparison of risks.

In order to provide additional data and perspective to current clinical, policy, and legal debates surrounding the prenatal use of cocaine in the USA, a retrospective cohort study was conducted to examine effects of cocaine on selected perinatal outcomes, and to compare the relative risks of adverse perinatal outcomes among users of cocaine and users of cigarettes. Using data from a large urban perinatal registry, relative risks of selected perinatal outcomes were determined for maternal cocaine users who were non-smokers of cigarettes, and used no marijuana, heroin, amphetamines, or alcohol (n = 64), and for cigarette smokers who do not use illicit drugs or alcohol during pregnancy (n = 3209). When compared with women with no recorded prenatal exposure to drugs or cigarettes (n = 13,043), cocaine users had higher risks than smokers for the following adverse outcomes: low birthweight [Relative Risk (RR) 5.3, 95% Confidence Interval (CI) 3.0-9.3], small-for-gestational age (SGA) [RR 4.2, 95% CI 2.4-7.3], prematurity [RR 4.0, 95% CI 2.3-7.0], abruptio placentae [RR 10.0, 95% CI 3.5-29.0], placenta praevia [RR = 2.4, 95% CI 0.3-17.8] and perinatal death [RR = 5.3, 95% CI 1.9-15.2]. Smokers who did not use any drugs experienced most of the same adverse perinatal outcomes as cocaine users, but the magnitude of risk was greater in cocaine users than in smokers for all outcomes. However, given the greater numbers of cigarette smokers than cocaine users in the population the numbers of infants in the population suffering these adverse outcomes is likely to be greater among offspring of cigarette smokers. The data support the current concern about the risk of cocaine, and current efforts to provide treatment to pregnant cocaine users. The data also underline the continued substantial risks of cigarette smoking to large numbers of pregnant women.

Adult↗
PubMed1996

Myogenic and central neurogenic factors in fatigue in multiple sclerosis.

Short episodes of electrical stimulation were applied to the right quadriceps muscle of patients with multiple sclerosis (MS) and healthy subjects at different times during 60 sec sustained voluntary muscle contractions at 0 to 100% levels of maximal voluntarily generated joint torque. The amplitude of electrically induced increments of torque (delta T) has been shown to depend upon both the level of muscular contraction and time from the beginning of the contraction. The dependence of delta T upon the time from the beginning of contraction has been assumed to reflect muscle fatigue. Patients with MS demonstrated an apparent involvement of central neurogenic mechanisms in fatigue manifested as a drop in muscle torque during sustained contractions at 75 and 100% levels when electrical stimulation was able to induce considerable increments in muscle torque. These patients also demonstrated a dependence of delta T upon the contraction level suggesting that they did not produce maximal voluntary contraction torque in the pre-trial. Fatigue in MS is due to central, neurogenic factors and does not seem to involve any myogenic factors such as might be related to secondary muscle changes due to the long-standing disorder. The subjective feeling of tiredness ('fatigue') may be related to a dissociation between central motor commands ('effort') and their mechanical consequences.

Adult↗
PubMed1995

Mortality ascertainment in the veteran population: alternatives to the National Death Index.

Veterans of the US military service constitute a dynamic cohort that is suitable for epidemiologic investigations. However, the ability to ascertain vital status is paramount to the value of this population in studies having mortality as a primary endpoint. The purpose of this study was to estimate and compare the mortality ascertainment obtained from the Department of Veterans Affairs Patient Treatment File and Beneficiary Identification and Record Locator System (BIRLS) with that obtained from the National Death Index on a cohort of 17,118 male veterans hospitalized in 1970 or 1971. Based on the 4,246 deaths identified in this cohort between 1979 and 1988, the sensitivities of BIRLS, the Patient Treatment File, and the National Death Index were 94.5%, 33.0%, and 96.7%, respectively. BIRLS was comparable with the National Death Index regarding mortality ascertainment and allowed for central acquisition of 89% of the death certificates from the Department of Veterans Benefits. There was no difference detected in the completeness of the BIRLS file before and after passage of the Omnibus Act in 1981. The Patient Treatment File served as a complement to BIRLS, providing additional mortality data and identification of hospitals for recall of medical records. The National Death Index provided the best mortality ascertainment, but acquistion of death certificates from individual states was extremely time consuming and expensive. The authors recommend greater consideration by investigators of sampling the veteran population and utilizing available Veterans Affairs databases for large studies in which mortality is the primary endpoint of interest.

Adult↗
PubMed1994

Large bowel cancer following gastric surgery for benign disease: a cohort study.

Early studies suggested that gastric surgery for benign ulcer disease was associated with a subsequent increase in the risk of large bowel cancer. Dietary fats, altered bacterial flora, and secondary bile acids are considered to play a major role in the disease etiology. Gastric surgery is known to alter bile salt metabolism as well as bacterial flora in the colon. This cohort study was designed to investigate the risk of large bowel cancer following gastric surgery for benign ulcer disease and to identify potential patient and treatment characteristics that may be associated with this risk. A cohort of 15,983 males was selected from Department of Veterans Affairs hospital admissions in 1970 and 1971. The exposed group (n = 7,609) included all males treated with gastric surgery (resection or vagotomy and drainage) for benign ulcer disease. The unexposed group (n = 8,374) was a random sample of all other male patients from the same time period and database. All subjects were followed through 1989 to identify vital status and cause of death. Deaths were identifiable by computerized linkage of the subjects' social security numbers with the Department of Veterans Affairs Beneficiary Identification Record Locator System and the National Death Index. The cause of death was documented by two certified nosologists from the death certificates of 99% of the deceased patients. Statistical analyses included estimations of risk based on standardized mortality ratios and standardized risk ratios. In this selected cohort, no increase in large bowel cancer risk was detected (risk ratio = 0.81, 95% confidence interval 0.62-1.05). The type of surgical procedure, ulcer diagnosis, age at the time of surgery, and length of follow-up did not alter the risk estimates. Unlike the previously identified increase in gastric cancer risk following ulcer surgery, no elevation in the risk of large bowel cancer following such surgery was detected in this study. Factors that may alter gastric surgery sequelae and resultant site-specific cancer risks deserve further investigations.

Adult↗
PubMed1994

Urinary tract infection during pregnancy: its association with maternal morbidity and perinatal outcome.

OBJECTIVES: The effects of antepartum urinary tract infection on adverse maternal and perinatal outcomes were examined. Antepartum urinary tract infection has been previously implicated as a risk factor for numerous outcomes. METHODS: Crude and multivariable analyses were performed with a perinatal registry cohort of 25,746 mother/infant pairs. RESULTS: Elevated risks were observed for exposure to urinary tract infection and low birthweight, prematurity, preterm low birthweight, premature labor, hypertension/preeclampsia, maternal anemia, and amnionitis. Urinary tract infection was associated with perinatal death only among subjects 20 to 29 years of age. CONCLUSIONS: These findings underscore the importance of antepartum urine screening to identify patients at risk for adverse outcomes.

Adult↗
PubMed1993

A cohort study of stomach cancer risk in men after gastric surgery for benign disease.

BACKGROUND: For the past 40 years, investigators have suggested that there exists an increased risk of stomach cancer following gastric surgery for benign disease. Recent cohort studies have consistently identified an increased risk of stomach cancer beginning 20 years or more following gastric surgery. Validation of this association and elucidation of risk factors related to gastric cancer have been complicated by variability in study designs. PURPOSE: This cohort study was designed to investigate the risk of stomach cancer following gastric surgery and to identify patient and treatment characteristics that may alter this risk. METHODS: Medical admission records of 17077 male military veterans hospitalized during 1970-1971 in U.S. Department of Veterans Affairs (VA) hospitals were examined. From this initial cohort, 1094 patients who died within the 1st year following gastric surgery were excluded. Data analysis was performed on the final cohort consisting of 15,983 patients divided into the following two groups: 1) an exposed group (gastric surgery group) that included 7609 patients receiving gastric surgery for a documented benign disorder and 2) an unexposed group (comparison group) that included 8374 male patients randomly selected from all other hospitalized male patients in the patient database. The comparison group was matched to the gastric surgery group by age (within 10 years), race, hospital, and year of admission. Mortality follow-up utilized the following three sources to identify vital status: 1) the VA Patient Treatment File (1970-1988), 2) the VA Beneficiary Identification Record Linkage System (1970-1989), and 3) the National Death Index (1979-1988). Death certificates were obtained for 99% of the deceased patients. Analyses included estimations of risk using standardized rate ratios (SRRs) and proportional hazards techniques. RESULTS: A statistically significant increase in risk of stomach cancer was demonstrated among males during the 20 years following gastric surgery (SRR = 1.9; 95% confidence interval [CI] = 1.3-2.4; P = .0001). The risk of developing gastric cancer was greatest during the 2nd to 5th postoperative years (SRR = 2.8; 95% CI = 1.6-4.5; P < .01) and during years 11-15 (SRR = 2.5; 95% CI = 1.2-4.8; P < .01). Also, the risk of developing gastric cancer was greatest among those treated by gastrectomy for any type of ulcer (SRR = 2.6; 95% CI = 1.2-4.9; P < .01) and those having any type of gastric surgery when the primary diagnosis was gastric ulcer (SRR = 2.9, 95% CI = 1.4-5.3; P < .01). CONCLUSIONS: This study confirms that men undergoing gastrectomy for benign disease and men receiving any gastric surgery for gastric ulcer are at increased risk for developing gastric cancer. Unlike earlier studies, we find that the increased risk is not delayed for 20 years.

Adult↗
PubMed1993

Sexual risk for HIV transmission among gay/bisexual men in substance-abuse treatment.

A sample of San Francisco gay/bisexual men in substance-abuse treatment (N = 314) was compared to the San Francisco Men's Health Study (SFMHS) cohort to compare levels of sexual behaviors that are high-risk for HIV transmission. Quantitative data were supplemented by analysis of transcripts of focus group discussions with gay men in treatment at the same agency. Sexual risk for HIV infection was significantly higher for gay/bisexual men in substance-abuse treatment than among the community-based (SFMHS) sample of gay/bisexual men. Among those entering outpatient alcohol/drug treatment, 21% reported unprotected insertive and sex, 23% reported unprotected receptive anal sex, and 32% reported unprotected insertive and/or receptive anal sex during the previous 3 months. In comparison, in the SFMHS cohort, 17% reported unprotected insertive and sex, 15% reported unprotected receptive anal sex, and 22% reported unprotected insertive and/or receptive anal sex during the previous 6 months. Substance abusers in focus groups identified a number of factors that made it difficult to reduce their sexual risk behavior, including the perceived disinhibiting effects of alcohol and other drugs, learned patterns of association between substance use and sex (especially methamphetamine use and anal sex), low self-esteem, lack of assertiveness and negotiating skills, and perceived powerlessness.

Alcoholism↗
PubMed1992

Anaerobic bacterial infections causing osteomyelitis/arthritis in a dog.

A 3-year-old German Shepherd Dog was examined for lameness, signs of pain, swelling, a draining fistulous tract, and osteolysis after a dog bite on the left carpus. After failure of the lesion to respond to several antibiotics, Peptostreptococcus sp and Propionibacterium sp were isolated from swab specimens and then from surgically collected bone and soft tissue specimens. The bone fragments had mild purulent osteomyelitis associated with numerous gram-positive rods and cocci. The dog was successfully treated by surgical debridement of the lesion and clindamycin administration.

Animals↗
PubMed1991

Cocaine use during pregnancy: perinatal outcomes.

The relation between maternal cocaine use and perinatal outcomes was investigated among 17,466 non-Asian singleton deliveries in 1988 from the University of Illinois Perinatal Network data base in the metropolitan Chicago area. Elevated adjusted relative risks (RR) of low birth weight (RR = 2.8, 95% confidence interval (CI) 2.2-3.7), prematurity (RR = 2.4, 95% CI 1.9-3.1), abruptio placentae (RR = 4.5, 95% CI 2.4-8.5), and perinatal death (RR = 2.1, 95% CI 1.1-4.0) were observed for "any" cocaine users (n = 408) compared with women who did not use cocaine or any other drugs or alcohol (n = 17,058). There was an increased (although unstable) risk of intrapartum placenta previa not previously reported (RR = 2.3, 95% CI 1.0-5.1). The relative risk of small-for-gestational-age births for cocaine users who did not smoke (RR = 3.4, 95% CI 1.8-6.5) was greater than that for cocaine users who did (RR = 2.1, 95% CI 1.1-4.1). Irrespective of smoking status, cocaine use during pregnancy increased the risk of small-for-gestational-age births.

Abruptio Placentae↗
PubMed1991

The reinforcing and subjective effects of morphine in post-addicts: a dose-response study.

The reinforcing and subjective effects of morphine were determined in five human volunteers with histories of i.v. heroin abuse. Subjects responded under a second-order schedule of i.m. injection. Under this schedule, every 100 lever presses produced a brief stimulus light [fixed ratio (FR) 100:s]; the 30th completion of the FR 100 requirement turned on the light for 15 min and the subject received an i.m. injection of morphine [FR 30 (FR 100:s)]. Once each weekday morphine or placebo was available under this schedule. Each drug dose was available for 1 week. Under these conditions placebo did not maintain responding; 3.75 mg of morphine maintained responding in four of five subjects, and higher morphine doses (7.5, 15 and 30 mg) maintained responding in all five subjects. Subjective effects were measured concurrently: these included measures of drug liking, the Morphine Benzedrine Group scale of the Addiction Research Center Inventory, drug detection and identification. Subjects did not report subjective effects different from placebo for the lowest dose of morphine; the intermediate doses of morphine produced inconsistent effects, and the highest dose of morphine occasioned reports of drug liking and "dope" identifications. These results indicate that there can be a significant dissociation of the reinforcing and the subjective effects of opioids, which has implications for theories of opioid abuse, particularly those assuming that the reinforcing effects are causally related to the euphoric effects of opioids. Furthermore, these results confirm that measures of reinforcing effects and measures of subjective effects do not necessarily lead to identical predictions when used to assess the liability for abuse of a substance.

Analgesia, Patient-Controlled↗
PubMed1990

Recent time trends in uterine cancer.

Recent trends in corpus uterine cancer incidence rates were explored using 1979-86 data from the Surveillance and End Results Program (SEER); recent trends in hospitalizations for corpus uterine cancer were explored using 1979-86 data from National Hospital Discharge Surveys (NHDS); and recent trends in exogenous hormone use were delineated using data from the 1980, 1981, and 1985 National Ambulatory Medical Care Surveys (NAMCS). Uterine cancer incidence rates using SEER data have continued to decline since 1979. An acceleration in the decline since 1983-84 is suggested in all women and in women with intact uteri ages 45-64. Hospitalizations for uterine cancer have also declined since 1979, with a marked acceleration in the decline since 1983-84 for all women and for women ages 40-79 has increased 22 percent and use of unopposed exogenous estrogens in women of similar age has increased 7 percent, while use of exogenous progesterones have shown much more substantial increases of approximately 700 percent. Possible relationships between trends in exogenous hormone use and incidence rates of corpus uterine cancer are discussed.

Adult↗
PubMed1989

The relationship of smoking and ectopic pregnancy.

A case-control study, using data abstracted between 1983 and 1987 from a large perinatal registry, was conducted to explore the relationship between smoking and ectopic pregnancy. Women with ectopic pregnancy (n = 634) seen at University of Illinois Perinatal Network Hospitals were compared to women who were delivered of a single live-born infant (n = 4287). Adjusted for age and race, women who reported smoking during pregnancy had a greater than twofold risk of ectopic pregnancy (Odds Ratio = 2.5, 95% confidence interval = 1.9, 3.2) compared to women who never smoked. The estimated relative risk rose from 1.4 (95% CI = 0.8, 2.5) for a woman smoking fewer than 10 cigarettes a day to 5.0 (95% CI = 2.9, 8.7) at one and a half or more packs of cigarettes per day (p-value for trend less than 0.001). Although further basic and epidemiologic research is necessary, the observed dose-response relation strengthens the argument that smoking may be a causal factor in the development of ectopic pregnancy.

Abortion, Spontaneous↗
PubMed1988

Organ donation in three major American cities with large Latino and black populations.

It has been suggested that areas with large inner-city Black and Latino populations have worse organ donation rates than those with large suburban and rural White populations. Yet data are sparse. We studied family refusal rates (FRRs) to cadaver organ donation between 1/84 and 5/87 in three United States city-areas (New York, Los Angeles, and Miami) with large Black and distinct Latino populations. Blacks are at least 18% and Latinos at least 25% of the combined general population of the three cities, totaling over three and four million people, respectively. In addition, Blacks and Latinos represent 42% of cadaver transplant recipients, 49% of patients on waiting lists, and 57% of the patients on dialysis in the three cities. Combining the data from the three cities, Black (45%) and Latino (43%) FRRs were similar (P = .78), and each was significantly higher than that in the White population (17%) (P less than 0.0001). The overall refusal rate in NYC (42%) was significantly higher (P less than .0001) than in LA (26%) or Miami (21%), and LA's refusal rate was significantly higher than Miami (P = .03). The refusal rates for the White (31%) and Black (55%) populations in NYC were each significantly higher than their respective populations in LA (14% and 33%) or Miami (11% and 36%) (P less than .05). Although Miami Latinos had a lower FRR (35%) than Latinos in NYC (46%) or LA (45%), the difference was not statistically significant (P = .19 and P = .20, respectively). In the three cities combined, 515 of a possible 1772 medically and legally eligible organ donors were lost during the 40 months studied due to families' refusal of consent. This represents approximately 1000 transplantable kidneys and large numbers of extrarenal organs. Further studies are needed to elucidate the reasons for differences in donation rate among groups and regions in the United States.

Black or African American↗