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Biomedical subjects

F Davis

Publications and source records attributed to F Davis.

At least 19 recordsLinked to original sources
PubMed1999

The role of ultrasound in patients with possible penetrating cardiac wounds: a prospective multicenter study.

BACKGROUND: Ultrasound is quickly becoming part of the trauma surgeon's practice, but its role in the patient with a penetrating truncal injury is not well defined. The purpose of this study was to evaluate the accuracy of emergency ultrasound as it was introduced into five Level I trauma centers for the diagnosis of acute hemopericardium. METHODS: Surgeons or cardiologists (four centers) and technicians (one center) performed pericardial ultrasound examinations on patients with penetrating truncal wounds. By protocol, patients with positive examinations underwent immediate operation. Vital signs, base deficit, time from examination to operation, operative findings, treatment, and outcome were recorded. RESULTS: Pericardial ultrasound examinations were performed in 261 patients. There were 225 (86.2%) true-negative, 29 (11.1%) true-positive, 0 false-negative, and 7 (2.7%) false-positive examinations, resulting in sensitivity of 100%, specificity of 96.9%, and accuracy of 97.3%. The mean time from ultrasound to operation was 12.1+/-5 minutes. CONCLUSION: Ultrasound should be the initial modality for the evaluation of patients with penetrating precordial wounds because it is accurate and rapid.

Acute Disease↗
PubMed1998

Radiologic evaluation of the acute abdomen in the patient with acquired immunodeficiency syndrome (AIDS): the role of CT scanning.

Abdominal complaints are common in the HIV-infected patient, and the signs and symptoms of disease may be masked by concurrent illness and a weak immune response, making accurate diagnosis difficult. Patients with acquired immunodeficiency syndrome (AIDS) are susceptible to diseases common to the general population; however, their generalized state of immunodeficiency places them at increased risk for many unusual disorders, predominately infectious and neoplastic. Radiologic evaluation, in particular, computed tomography (CT) with its ability to image the entire abdomen and pelvis, plays a crucial role in the prompt and accurate diagnosis and treatment of these patients.

AIDS-Related Opportunistic Infections↗
PubMed1998

Musculoskeletal complications of the patient with acquired immunodeficiency syndrome (AIDS): CT evaluation.

Musculoskeletal disorders are infrequent complications of HIV infection in this country. However, AIDS patients are susceptible to a wide range of musculoskeletal complications, from the common to the otherwise uncommon. The following is a summary of some of the more frequently encountered musculoskeletal manifestations of these disorders within the HIV-positive community and their associated imaging characteristics.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Brain tumor survival: results from the National Cancer Data Base.

Hospital-based data reported to the National Cancer Data Base (NCDB) were available for over 60,000 patients with a primary brain tumor diagnosed from 1985-1988 and 1990-1992. The most common histologies were glioblastomas, astrocytomas and meningiomas. Five-year survival rates for these tumors were 2%, 30% and 70% respectively. Histology, age at diagnosis, behavior, and location were important variables in estimating survival. Comparisons with population-based registry data suggest that the malignant tumors are well represented in NCDB, but the benign histologies are under-reported. Survival estimates for the malignant tumors are comparable to previously reported studies. The NCDB provides recent information on brain tumor distribution and survival patterns not available in other large databases.

Adolescent↗
PubMed1998

The descriptive epidemiology of craniopharyngioma.

OBJECT: In this report the authors describe the epidemiology of craniopharyngioma. METHODS: The incidence of craniopharyngioma in the United States was estimated from two population-based cancer registries that include brain tumors of benign and borderline malignancy: the Central Brain Tumor Registry of the United States (CBTRUS) and the Los Angeles county Cancer Surveillance Program. Information on additional pediatric tumors was available from the Greater Delaware Valley Pediatric Tumor Registry (GDVPTR). The overall incidence of craniopharyngioma was 0.13 per 100,000 person years and did not vary by gender or race. A bimodal distribution by age was noted with peak incidence rates in children (aged 5-14 years) and among older adults (aged 65-74 years in CBTRUS and 50-74 years in Los Angeles county). Survival information was available from GDVPTR and the National Cancer Data Base (NCDB), a hospital-based reporting system. In the NCDB, the 5-year survival rate was 80% and decreased with older age at diagnosis. Survival is higher among children and has improved in recent years. CONCLUSIONS: Craniopharyngioma is a rare brain tumor of uncertain behavior that occurs at a rate of 1.3 per million person years. Approximately 338 cases of this disease are expected to occur annually in the United States, with 96 occurring in children from 0 to 14 years of age.

Adolescent↗
PubMed1998

Managing care in an integrated delivery system via an Intranet.

The CareGroup Provider Service Network is a managed care contracting organization which provides central administrative services for over 1800 physicians and 200,000 managed care lives. Services include utilization management, disease management and credentialing for the entire network. The management model of the Provider Service Network empowers local physician groups with information and education. To meet the managed care information needs of the network, we implemented an intranet-based executive information system, PSNWeb, which retrieves data from a managed care data warehouse. The project required the integration of diverse technologies and development of a complex security/confidentiality infrastructure to deliver information to 8 major clinician groups, each with different information needs.

Computer Security↗
PubMed1997

The effect of intravenous administration of a chimeric anti-IgE antibody on serum IgE levels in atopic subjects: efficacy, safety, and pharmacokinetics.

CGP 51901 is a non-anaphylactogenic mouse/human chimeric anti-human IgE antibody that binds to free IgE and surface IgE of IgE-expressing B cells but not to IgE bound to high affinity IgE receptors (Fc epsilonR1) on mast cells and basophils or low affinity IgE receptors (Fc epsilonR2) on other cells. A phase 1 double-blind, placebo-controlled, single dose study with doses of 3, 10, 30, and 100 mg of CGP 51901 was conducted in 33 pollen-sensitive subjects who had raised levels of serum IgE and received either intravenous CGP 51901 or placebo. The administration of CGP 51901 was well tolerated and resulted in a decrease of serum free IgE levels in a dose-dependent manner, with suppression after 100 mg of CGP 51901 reaching > 96%. Time of recovery to 50% of baseline IgE correlated with the dose of administered antibody and ranged from a mean of 1.3 d for the 3 mg to 39 d for the 100 mg dose. Total IgE, comprised of free and complexed IgE, increased as stored and newly synthesized IgE bound to CGP 51901. Complexed IgE was eliminated at a rate comparable with the terminal half-life of free CGP 51901 (11-13 d at all doses). Only one subject showed a weak antibody response against CGP 51901. We conclude that the use of anti-human IgE antibody is safe and effective in reducing serum IgE levels in atopic individuals and provides a potential therapeutic approach to the treatment of atopic diseases.

Adolescent↗
PubMed1997

Evaluation of internal alpha-particle radiation exposure and subsequent fertility among a cohort of women formerly employed in the radium dial industry.

This study examined the effect of internal exposure to alpha-particle radiation on subsequent fertility among women employed in the radium dial industry prior to 1930, when appreciable amounts of radium were often ingested through the practice of pointing the paint brush with the lips. The analysis was limited to women for whom a radium body burden measurement had been obtained and who were married prior to age 45 (n = 603). Internal radiation dose to the ovary was calculated based on initial intakes of radium-226 and radium-228, average ovarian mass, number and energy of alpha particles emitted, fraction of energy absorbed within the ovary, effective retention integrals and estimated photon irradiation. Time between marriage and pregnancy, number of pregnancies and number of live births served as surrogates for fertility. Radiation appeared to have no effect on fertility at estimated cumulative ovarian dose equivalents below 5 Sv; above this dose, however, statistically significant declines in both number of pregnancies and live births were observed. These trends persisted after multivariable adjustment for potential confounding variables and after exclusion of subjects contributing a potential classification or selection bias to the study. Additionally, the high-dose group experienced fewer live births than would have been expected based on population rates. There were no differences in time to first pregnancy between high- and low-dose groups. These results are consistent with earlier studies of gamma-ray exposures and suggest that exposure to high doses of radiation from internally deposited radium reduces fertility rather than inducing sterility.

Abortion, Spontaneous↗
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↗