Biomedical subjects

V C Arena

Publications and source records attributed to V C Arena.

At least 19 recordsLinked to original sources

PubMed1995

Variation in the use of red blood cell transfusions. A study of four common medical and surgical conditions.

This study assessed variation in red cell transfusion practice among adult patients hospitalized with ulcer disease (ULCER), and those undergoing coronary artery bypass grafting (CABG), hip surgery (HIP), or total knee replacement (KNEE). The study design was a retrospective analysis of the 1989 MedisGroups Hospital Comparative Database, and the participants were adult patients presenting for their first admission with ULCER (N = 4,664), CABG (N = 6,812), HIP (N = 4,131) or KNEE (N = 3,042) in the MedisGroups Hospital Comparative Database. Outcome measures were whether a patient was transfused, and the number of units transfused. Logistic regression was used to analyze the decision to transfuse, and linear regression to analyze the number of units transfused. In these analyses, patient characteristics, hospital characteristics, and unique hospital identity were used as independent variables. The percentage of patients transfused was ULCER 50%, CABG 81%, HIP 69%, and KNEE 51%. The range among hospitals in the percentage of patients transfused was ULCER 11% to 76%, CABG 51% to 100%, HIP 36% to 95%, and KNEE 9% to 97%. When only patient characteristics were entered in the linear regression analyses, the R2 values were ULCER 0.33, CABG 0.11, HIP 0.11, and KNEE 0.07. When hospital was added, the R2 increased to ULCER 0.38, CABG 0.29, HIP 0.19, and KNEE 0.20 (P < 0.0001 for the change for all analyses). The results of the logistic regression analyses of the probability of transfusion were similar. There is substantial interhospital variation in the proportion of patients transfused and number of units transfused in the four conditions studied. Patient demographic and clinical characteristics explain a substantial proportion of the variation in transfusion practices for ulcer patients, but little of the variation in the three surgical conditions.

Adult↗

PubMed1991

Failure to alter the course of acute myelogenous leukemia in the rat with subcutaneous deferoxamine.

Deferoxamine (DFO) is an iron chelator that is known to inhibit acute non-lymphocytic leukemia cells in vitro. To explore the possibility that this drug has cytotoxic activity in vivo, rats were inoculated with a small lethal dose (10(2] of tumor cells from the transplantable BN acute myelogenous leukemia model. Animals were then treated with one of several regimens of bolus subcutaneous DFO: 10 mg/day x 5; 20 mg/day x 5; 10 mg/day x approximately 5 weeks; or no DFO. There were no consistently significant differences in survival between any of the DFO and untreated groups. Because the short plasma half-life of DFO was thought to be a potential reason for this lack of protection, a high molecular weight polymeric conjugate of DFO that is known to provide sustained intravascular drug levels was also studied. However, hydroxyethyl starch conjugated with DFO in amounts equivalent to 100 mg free drug (intraperitoneally for 5 days) also failed to have major impact on survival. These findings suggest that it may not be possible to achieve levels of this chelating agent in vivo that are cytotoxic for this disease.

Animals↗

PubMed1991

Survival of patients with well-differentiated astrocytomas diagnosed in the era of computed tomography.

We report 25 verified cases of well-differentiated cerebral astrocytomas in adults treated between 1978 and 1988. All patients were diagnosed by computed tomographic (CT) scans, with 5 undergoing a craniotomy for debulking and 20 undergoing a biopsy alone. The median survival for the entire group was 8.2 years, the longest survival yet reported for a series of patients with these tumors. A review of the literature suggests that the longer survival observed in more recent series is the result of the earlier diagnosis of tumors afforded by modern brain imaging. Twenty of our patients presented with seizures in the absence of any other focal findings and would probably not have had a biopsy in the era before CT scans until their tumors had progressed. Only 8% of our patients had papilledema at the time of presentation, in contrast to almost half of the patients with low-grade astrocytomas reported before 1975, supporting the hypothesis that patients in the CT era are diagnosed earlier. None of our patients died from progressive low-grade disease. One patient died from a squamous cell cancer, and 7 died as a consequence of their tumors dedifferentiating into a more malignant astrocytoma or glioblastoma multiforme, with a median time of approximately 5 years after the diagnosis. Our findings, together with the available data in the literature, suggest that death from a focal low-grade astrocytoma, in the absence of malignant degeneration, may be a rare event. Consequently, future therapeutic efforts should be targeted at preventing dedifferentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

Histocompatibility and other risk factors for histological rejection of human cardiac allografts during the first three months following transplantation.

A histological analysis of 2564 endomyocardial biopsies was conducted in 349 cardiac transplant patients to determine potential risk factors for acute cellular rejection during the first three months following transplantation. This analysis dealt with the frequency, time of onset, and duration of cellular rejection. Patients on perioperative RATG experienced significantly less rejection than patients on OKT3 or without antilymphocyte antibody immunoprophylaxis. A trend was noted toward increased rejection in recipients diagnosed originally with chronic myocarditis compared with patients in other disease categories including ischemic heart disease and dilated cardiomyopathy. No significant differences were seen in histological rejection between male and female recipients. On the other hand, patients over 55 years of age were found at lower risk of histological rejection. The results of this analysis have demonstrated quite clearly, but not unexpectedly, that a greater degree of HLA mismatching correlates with increased cellular rejection. This effect was noted not only for the HLA-A,B and DR antigens, but also HLA-DQ and HLA-DRw52/53 antigens. In multivariate analysis, the highest level of statistical significance was obtained for the combined HLA-A,B,DR and DQ group. Sensitized patients with panel-reactive lymphocytotoxic antibodies of greater than 10% experienced more histological rejection than nonsensitized patients. On the other hand, a positive lymphocytotoxic crossmatch did not appear to influence cellular rejection of cardiac allografts. Also, no differences were seen in histological rejection between ABO-identical and compatible heart transplants. These findings further support the concept that donor HLA compatibility and pretransplant sensitization represent significant risk factors for cellular rejection in cardiac transplantation.

Adolescent↗

PubMed1990

Wood-burning stoves and lower respiratory tract infection in American Indian children.

Some studies suggest that home use of wood-burning stoves is an independent risk factor for lower respiratory tract infection in young children. To test this hypothesis in a population with a high prevalence of wood-burning stove use, we studied Navajo children with diagnosed pneumonia or bronchiolitis. We matched each case (less than or equal to 24 months of age) with a child of identical sex and age who was seen for well-child care or a minor health problem, and we interviewed an adult caretaker about family history and environmental exposures. Analyzing 58 case-control pairs, we found that home wood-burning stove use, recent respiratory illness exposure, family history of asthma, dirt floors, and lack of running water in the home increased the risk of lower respiratory tract infection. On multiple logistic regression analysis, however, only wood-burning stove use and respiratory illness exposure were independently associated with higher risk.

Bronchiolitis↗

PubMed1990

Depressive symptomatology and medical co-morbidity in a primary care clinic.

Most primary care patients exhibiting significant depressive symptomatology fail to meet DSM-III criteria for a major depressive disorder (MDD). Yet, such patients have substantial morbidity and dysfunction attributable to their affective syndrome. Since surprisingly little is known about this group's clinical characteristics, we studied 618 general medicine patients aged eighteen to sixty-four years. In this population, fifty-seven (9.2%) scored quite high when screened on the Center for Epidemiological Studies Depression Scale (greater than or equal to 27) while not meeting MDD criteria on the Diagnostic Interview Schedule. Membership in the "depression symptoms only" (DSO) group was predicted by a logistic regression model including female gender, more severe medical illness, higher likelihood of operative procedures, and less frequent cardiovascular diagnoses. Our findings suggest that the DSO state is associated with substantial "medical" morbidity. Prospective studies of subclinical depression in the primary care setting are urged to clarify etiologic and treatment concerns.

Adjustment Disorders↗

PubMed1990

Determinants of blood pressure in Navajo adolescents.

Hypertension is becoming more common among Navajo people, especially among young men. In a group of 580 Navajo adolescents, we looked for factors associated with variations in blood pressure level. Using our criteria, 11.1% of adolescent males and 1.6% of females had an elevated screening blood pressure. In males, blood pressure was a function of age only, and not significantly related either to obesity (body mass index) or measures of acculturation and personal adjustment. In females, blood pressure was not related to age, but was associated with body mass index. Systolic pressure in females was also associated with poor personal adjustment. Level of acculturation (by our index) had no bearing on blood pressure level in this population.

Acculturation↗

PubMed1990

Prognosis of patients hospitalized with community-acquired pneumonia.

PURPOSE: Our purpose was to determine which clinical features predict short-term mortality in patients with community-acquired pneumonia. PATIENTS AND METHODS: We conducted a prospective multicenter study of 347 patients hospitalized in Pittsburgh (the derivation cohort) and 253 hospitalized and ambulatory patients in Boston (the validation cohort) with clinical and radiographic evidence of pneumonia. Patients in the derivation cohort underwent an extensive microbiologic evaluation including bacteriologic sputum culture, blood cultures, direct fluorescent antibody testing for Legionella species, and serologic testing for Mycoplasma pneumoniae, Legionella species, and Chlamydia TWAR. RESULTS: The overall mortality was 18% in the derivation cohort and 13.2% in the validation cohort. We identified five independent predictors of mortality in the derivation cohort: pleuritic chest pain (risk ratio, 0.4; 95% confidence interval [CI], 0.17 to 0.99), mental status changes (risk ratio, 2.6; 95% CI, 1.4 to 4.6), a severe vital sign abnormality (risk ratio, 2.1; 95% CI 1.2 to 3.6), neoplastic disease (risk ratio, 5.0; 95% CI, 2.7 to 9.1), and "high-risk" pneumonia etiology (risk ratio, 2.8; 95% CI, 1.6 to 5.0). A mortality index based on these factors accurately classified patients into five risk classes of increasing mortality. In the derivation cohort, the 6-week mortality rates were 0% in class I, 2.9% in class II, 13.1% in class III, 32.7% in class IV, and 89.5% in class V. There was little deterioration in the predictive accuracy of the model when tested in the validation cohort: mortality was 2.2% in class I, 0% in class II, 13.5% in class III, 33.3% in class IV, and 55.6% in class V. CONCLUSIONS: This prognostic classification may help direct triage decisions, assess appropriateness of care, and guide the design and analysis of therapeutic trials in patients with community-acquired pneumonia.

Adolescent↗

PubMed1990

Medical comorbidity of major depressive disorder in a primary medical practice.

Despite much speculation about the relationship between depression and medical comorbidity in primary care settings, few investigators have examined this issue empirically. Using a two-stage screening procedure, we assessed 618 patients aged 18 to 64 years in an academic general medicine clinic. Forty-one patients (6.6%) suffered from a current episode of major depressive disorder (MDD). We compared this group with a 20% random sample of nondepressed patients. While patients with MDD were younger (mean age, 41.1 vs 47.2 years), they were assessed by the Duke University Severity of Illness Scale as having more severe medical illness. Patients with MDD were more likely to have malignant tumors and "ill-defined conditions" than nondepressed patients. The 18 patients with MDD (44%) who were correctly diagnosed by their physicians had less severe medical illness than those whose depression was clinically undetected. A logistic regression model predicting MDD group membership included female gender, younger age, higher Duke University Severity of Illness Scale score, and more frequent inactive ill-defined diagnoses. These findings are consistent with assertions: (1) patients with MDD have more physical illness than nondepressed patients and/or (2) somatic symptoms and disability caused by MDD add to the burden of physical illness.

Adult↗

PubMed1990

The duration of Holter monitoring in patients with syncope. Is 24 hours enough?

To determine the incremental yield of ambulatory monitoring in the evaluation of syncope, three serial 24-hour Holter recordings were obtained in a consecutive series of 95 patients with syncope, the cause of which was not explained by history, physical examination, or 12-lead electrocardiogram. The mean age of patients was 61 years and 41% were men. Major electrocardiographic abnormalities were found in 26 patients (27%), including unsustained ventricular tachycardia (19 patients), pauses of at least 2 seconds (8 patients), profound bradycardia (1 patient), and complete heart block (1 patient). The first 24-hour Holter recording had at least one major abnormality in 14 patients (15%) (95% confidence interval, 8.3% to 23.4%). Of the 81 patients without a major abnormality on the first Holter recording, the second Holter recording had major abnormalities in 9 (11%) (95% confidence interval, 5.1% to 20.0%). Of the 72 patients without a major abnormality on the first two Holter recordings, only 3 patients (4.2%) had a major abnormality on the third Holter recording (95% confidence interval, 0.8% to 11.7%). Four factors were significantly associated with an increased likelihood of a major abnormality on 72 hours of monitoring: age above 65 years (relative risk, 2.2), male gender (relative risk, 2.0), history of heart disease (relative risk, 2.2), and an initial nonsinus rhythm (relative risk, 3.5). These results suggest that 24 hours of Holter monitoring is not enough to identify all potentially important arrhythmias in patients with syncope. Monitoring may need to be extended to 48 hours if the first 24-hour Holter recording is normal.

Adolescent↗

PubMed1989

Relationships between serum testosterone, fasting insulin and lipoprotein levels among elderly men.

We have previously reported the existence of an association between endogenous male sex hormone and lipoprotein levels in elderly men confined to a nursing home. In a further attempt to elucidate the significance of the association mentioned, we studied the relationship existing in that population between serum testosterone and fasting insulin levels, and between fasting insulin level and lipoprotein pattern. The data were analysed by means of stepwise multiple regression analyses. Serum testosterone and fasting insulin were found to be strongly correlated; this is consistent with the notion that androgen secretion affects directly circulating insulin level. But no independent relationship was demonstrable between fasting insulin and the three lipid-lipoprotein categories studied, namely total serum cholesterol, triglyceride and HDL-cholesterol, suggesting that in this particular population, the effect of male sex hormones upon lipoproteins is not mediated through insulin. Together, these various observations support the belief that androgen secretion affects significantly CAD risk factor levels in elderly men.

Aged↗

PubMed1989

The relationship between women's attitudes about condoms and their use: implications for condom promotion programs.

A survey of 759 women attending contraceptive care clinics revealed that a majority of women endorsed condom use as an important way to reduce the spread of AIDS (acquired immunodeficiency syndrome); 82 per cent reported past use of condoms, but only 14 per cent reported using condoms in addition to another form of contraception to prevent infection with sexually transmitted pathogens, including HIV (human immunodeficiency virus). Acceptance of condom advertisement, perceived male and peer acceptance of condoms, and the effect of condom use on the enjoyment of sexual intercourse predicted condom use.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Long-term prognosis of patients undergoing electrophysiologic studies for syncope of unknown origin.

Long-term prognosis was determined in 70 patients with unexplained syncope who underwent electrophysiologic testing between April 1981 and April 1986. The electrophysiologic study had positive results in 37 patients--31 with ventricular tachycardia, 3 with supraventricular tachycardia and 3 with abnormal conduction. There was no significant difference in the 3-year actuarial recurrence rate between the positive and negative outcomes (32 vs 24%, respectively). At 3 years, patients with positive outcomes had higher rates of sudden death than patients with negative results (48 vs 9%, respectively, p less than 0.002). The 3-year total mortality rate was also markedly higher in patients with positive results than among those with negative outcomes (61 vs 15%, respectively, p less than 0.001). Multivariate analyses showed mortality to be independently associated with unsustained ventricular tachycardia on prolonged electrocardiographic monitoring. It was concluded that patients with electrophysiologically positive results had high rates of sudden death and total mortality that have not been previously well recognized.

Bundle-Branch Block↗

PubMed1988

More frequent diagnosis of acute myocardial infarction among Navajo Indians.

In an earlier study, we failed to confirm a clinical impression that the incidence of acute myocardial infarction (AMI) was increasing in Navajo men. Extending our data collection an additional three years, through 1986, we observed that the attack rate in men more than doubled and there was a gradual increase among women. Most Navajos who sustain AMI are hypertensive (51 per cent), diabetic (50 per cent) or both (31 per cent), but few smoke cigarettes.

Adult↗

PubMed1987

A controlled study of survival with dementia.

Widely conflicting data exist regarding the relationship of dementia to mortality and the relative risk of senile dementia of the Alzheimer type vs multi-infarct dementia with respect to mortality. In a historic prospective study, 202 patients with dementia were matched by age and sex with 202 nondemented controls attending the same geriatric assessment clinic and receiving comparable medical and psychiatric care. The three-year survival rate was 70% for patients with dementia and 84% for controls. Patients with multi-infarct dementia survived more poorly than patients with senile dementia of the Alzheimer type, but the difference did not reach statistical significance. The relative risk associated with dementia in the context of a multivariate analysis was 1.92 (95% confidence [1.25, 2.97]). We conclude that dementia carries a significantly increased risk of mortality but that the survival of patients with dementia may be better than previous reports would suggest.

Aged↗

PubMed1985

Simultaneous measurements of cerebral blood flow by the xenon/CT method and the microsphere method. A comparison.

Simultaneous measurements of cerebral blood flow have been performed in baboons to assess the correlation between the acute and invasive nondiffusible microsphere technique and the noninvasive xenon-enhanced CT method. Blood flows in small tissue volumes (approximately 1 cm3) were directly compared. The results of these studies demonstrate a statistically significant association between the two methods (P less than .001). Similar correlations were obtained by both the Kendall tau (tau) and the Spearman (r) methods. The problems and limitations of such correlations are discussed.

Animals↗

PubMed1983

Mortality studies of aluminum reduction plant workers: potroom and carbon department.

The purpose of this study was to investigate mortality patterns of aluminum reduction plant workers. A cohort was formed of 21,829 workers with five or more years employment in 14 reduction plants. Progress of the study was reported quarterly to a Tripartite Committee consisting of representatives from labor, management and government. Although the results of other studies relative to an excess of lung cancer in aluminum workers were not confirmed, there were indications of a higher than expected mortality in pancreatic cancer, lymphohematopoietic cancers, genitourinary cancer, nonmalignant respiratory disease and benign and unspecified neoplasms.

Aluminum↗

PubMed1980

Herpes zoster after splenectomy. A study of patients without malignancy.

Follow-up information was obtained on 102 unselected patients who had undergone splenectomy for nonmalignant disease (ie, trauma, surgical complications, and hematologic indications). In 422 postsplenectomy years, three cases of herpes zoster were observed, two of which were associated with generalized cutaneous dissemination. This incidence is no greater than that reported elsewhere for age-matched normal population. We conclude that in patients without malignancy, splenectomy does not predispose to herpes zoster, but may play a role in cutaneous dissemination.

Adult↗