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Biomedical subjects

B Simmons

Publications and source records attributed to B Simmons.

At least 37 records · Page 2Linked to original sources
PubMed1989

Coronary arteriography and coronary bypass survey among whites and other racial groups relative to hospital-based incidence rates for coronary artery disease: findings from NHDS.

To assess racial differences in health care utilization for coronary artery disease (CAD) the data of the National Hospital Discharge Survey (NHDS) from 1979-84 were examined. Discharge rates for acute myocardial infarction (AMI) were utilized as a measure of hospital-based incidence and relative need for the designated cardiac procedures. Although 35-74 year old Black men had discharge rates of AMI that were 77 per cent of those observed for White men, they underwent coronary arteriography half as often and were only a third as likely to have coronary artery bypass graft (CABG) surgery. Black women in this age range were hospitalized at a slightly higher rate than White women for AMI, yet experienced a 19 per cent lower rate of coronary arteriography and a 52 per cent lower rate of CABG surgery. These data suggest a racial bias in the pattern of care delivered for CAD in US hospitals at the present time.

Adult↗
PubMed1988

Description of case-mix adjusters by the Severity of Illness Working Group of the Society of Hospital Epidemiologists of America (SHEA).

Hospitals, insurance companies, and federal and state governments are increasingly concerned about reducing patient cost expenditures while maintaining high quality patient care. One method of reducing expenditures has been to tie hospital reimbursement with a prospective payment system based on diagnosis-related groups (DRGs). However, reimbursement under the DRG system is not acceptable for all patients in all hospitals because it is neither an accurate predictor of costs nor of clinical outcome. This deficiency poses significant problems for hospitals because DRGs are used nationwide as the prospective payment system for inpatients covered by Medicare. Several case-mix adjusters have been proposed to modify DRGs to improve their accuracy in predicting costs and outcome. We reviewed five of the most widely available indices: Acute Physiologic and Chronic Health Evaluation (APACHE II), Coded Disease Staging, Computerized Severity Index (CSI), Medical Illness Severity Group System (MEDISGROUPS), and Patient Management Categories (PMC). Recommendations for the use of a single case-mix adjuster cannot be made at this time because all indices have not been compared in sufficiently diverse settings and because some are better predictors of costs while others are better predictors of clinical outcome. Hospital epidemiologists and other infection control practitioners should be informed about these indices and their potential applications as they expand their role beyond infection control problems to issues concerning cost containment, quality assurance, and reimbursement.

Cost Control↗
PubMed1988

Sex differences in high density lipoprotein cholesterol in urban blacks.

Descriptive data on high density lipoprotein (HDL) cholesterol in the black urban population of the United States are limited. We examined 119 men and 130 women aged 21-70 years who were attending a screening clinic at Cook County Hospital in Chicago, Illinois, in 1985-1986 for minor complaints; all participants were black. For men, lipid values were: total cholesterol, 209.5 +/- 50.6, HDL cholesterol, 55.2 +/- 16.5; for women, values were: total cholesterol, 215.6 +/- 47.4, HDL cholesterol, 59.2 +/- 17.2. Correlates of HDL cholesterol were different in men and women. Alcohol consumption and body mass index were significantly related to HDL cholesterol in men; however, education was the only significant factor among women. It was anticipated that the increased obesity among the women in this sample (mean body mass index, 31 kg/m2; range, 18.4-50.0 kg/m2) compared with men (mean body mass index, 27 kg/m2; range, 19.4-45.0 kg/m2) would explain part of the narrowing of the gap between the sexes in HDL cholesterol values. The association between HDL cholesterol and body mass index among women, however, was weak and nonsignificant. The increased susceptibility of black women to coronary artery disease has not been adequately explained and undoubtedly reflects a complicated interaction of epidemiologic factors.

Adult↗
PubMed1988

Regulation of cellular and humoral immune responses to collagen type I or collagen type II.

We have investigated the characteristics of antigen-specific reductions in murine immune responses to rat collagen type I (R-CI), chick collagen type II (C-CII) or bovine collagen type II (B-CII). Intravenous pretreatment with the appropriate soluble collagen or collagen-coupled spleen cells led to the development of antigen-specific reduced immune responses, the former treatment being more effective than the latter. In the case of CII, pretreatment with R-CI or non-related antigens was ineffective. However, pretreatment with denatured bovine-CII, native bovine-CII or chick-CII led to immune hyporesponsiveness for either the homologous or heterologous CII molecule. A delayed development of the diminished immune responses was observed for the cell-mediated immune response (CMI), as measured by in vivo delayed-type hypersensitivity (DTH), in that no reduction was evident at Day 7 but a significantly decreased response was observed at Day 14. Collagen-specific IgG and IgM antibody responses were consistently reduced by the pretreatment and remained reduced during the study period. The antigen-specific hyporesponsive state was not sensitive to cyclophosphamide treatment and was not transferable with hyporesponsive spleen cells. Additionally, we have induced unresponsiveness to CII by treating mice with an antibody directed to T helper cells (GK1.5). This treatment led to profound reductions in CII CMI responses as well as CII antibody levels. However, this unresponsive state is not permanent and not transferable with spleen cells from treated mice. These two types of procedures, soluble B-CII i.v. or GK1.5 treatment, not only resulted in CII hyporesponsive states, but also produced delayed onset and decreased incidence of arthritis in the appropriate strains.

Animals↗
PubMed1987

Avascular necrosis of the proximal carpal row. A case report.

Avascular necrosis of bone has been described in many sites, including the carpal bones. The case history of a patient with avascular necrosis of the entire proximal row, previously undescribed, is detailed. Numerous contributing factors, including steroid administration, hyperlipidemia, and systemic lupus erythematosus are noted. Occult wrist pain in any patient with known risk factors for avascular necrosis is a warning sign; early bone scan may help prevent late complications.

Adult↗
PubMed1987

In-hospital mortality rates from acute myocardial infarction by race in U.S. hospitals: findings from the National Hospital Discharge Survey.

Mortality rates in the United States from coronary artery disease are higher among blacks than whites at younger ages, with a crossover to lower rates above the age of 70. The factors that determine this crossover of age-specific death rates have not been elucidated. Selection from the black population of younger individuals who are sicker by virtue of being more coronary prone might leave a relatively healthier group of older persons. Support for this hypothesis would consist in part of evidence that coronary artery disease has an earlier onset in the black population. We examined data from the National Hospital Discharge Survey for the years 1973-1984 to determine if age-related differences in case-fatality rates existed between whites and nonwhites. In-hospital case fatality rates were 10% to 70% higher for each of the 10 year age groups for nonwhites up to age 70, at which time a crossover occurred. The median age at death from myocardial infarction was approximately 5 years younger in nonwhites compared with whites. National estimates of hospitalization rates for myocardial infarction from these data likewise suggest that nonwhites receive less health care for coronary artery disease than whites relative to recorded fatal events. The age-specific trends in case-fatality support the hypothesis that a cohort selection effect in part determines the black/white differentials in coronary artery disease. Relative susceptibility of the black and white population is thus not appropriately estimated by age-adjusted rates, but should be examined on an age-specific basis within the framework of selection effects on a cohort.

Adult↗
PubMed1986

Survival rates and prehospital delay during myocardial infarction among black persons.

Over a 12-month period, a consecutive series of 111 black patients admitted to a municipal hospital in Chicago was studied. The 2-week mortality rate for the entire group was 19% (95% confidence intervals, 11.7 to 26.3), and the rate was twice as high for women as for men. A history of systemic hypertension was encountered in 75% of the patients, and diabetes mellitus was present in 33%, although they were not significant predictors of mortality within this group. The delay time from onset of symptoms to arrival at the hospital was markedly prolonged compared with studies of predominantly white populations--twice as long at the median and 3 times as long at the mean. Preventive campaigns aimed at this population should include educating patients on the symptoms of coronary artery disease and encouraging them to seek prompt medical care. Attention must also be given to eliminating obstacles to access to care in this group.

Adult↗
PubMed1986

Characteristics of cellular immune responses to collagen type I or collagen type II.

We have examined the murine cell-mediated immune (CMI) response to collagens type I (CI) and type II (CII) as measured by in vivo delayed-type hypersensitivity responses. We have verified the histopathology and kinetics of the cell-mediated immune responses. Predominant cell-mediated responses were obtained 7, 10, or 14 days following immunization. A presumed antibody-mediated reaction was observed at later times (e.g., greater than 21 days following immunization). The CMI responses to the collagens show a strain-dependent relationship. For CI, the CMI response profile shows H-2b greater than or equal to H-2k = H-2q much greater than H-2d. For bovine CII, the response profile is H-2d greater than H-2b = H-2k = H-2q; the chick CII response profile is H-2q = H-2k greater than H-2b = H-2d, and in limited testing, only the H-2q strain could generate murine CII-specific cell-mediated immune responses. The CII-specific CMI response is cross-reactive with CII from several species of animals, but not with CI. Further, the collagen-specific CMI response can be elicited with certain cyanogen-bromide fragments of bovine CII. Finally, our study also demonstrates that there is a non-H-2-linked locus(i) involved in the development of CII-induced arthritis.

Animals↗
PubMed1985

Protection from guanethidine-induced neuronal destruction by nerve growth factor: effect of NGF on immune function.

The chronic administration of guanethidine causes an immune-mediated destruction of sympathetic neurons in rats. Destruction can be prevented by various immunosuppressive agents, including gamma-irradiation and cyclophosphamide, as well as by administration with nerve growth factor (NGF). Experiments were conducted to determine whether: (1) NGF prevented accumulation of guanethidine within sympathetic neurons; and (2) NGF caused an inhibition of immune function by either blocking proliferation of immune-competent cells or by blocking effector function even in the presence of antigen and activated immune cells. NGF did not prevent accumulation of guanethidine within sympathetic ganglia in vivo, a necessary prerequisite for neuronal destruction, nor was it inhibitory on immune function using several assay systems. NGF, purified by either conventional methods or additionally by HPLC ("ultrapure'), did not inhibit either proliferation of cloned cytotoxic T lymphocytes (CTL) to antigen (class I major histocompatibility antigens) or lysis of target cells bearing the appropriate antigens. In addition, NGF did not exhibit growth stimulating effects in this assay system (i.e. it could not substitute for T cell growth factor). NGF also did not cause an inhibition of either murine or rat allogeneic mixed lymphocyte responses measured by lysis of appropriate target cells or proliferation, respectively. Finally, NGF did not inhibit, but rather appeared to stimulate the antibody response to sheep red blood cells generated in vivo in young rats. Thus NGF does not appear to prevent the immune-mediated neural destruction induced by guanethidine by acting as an immunosuppressive agent, but rather acts by some other mechanism such as preventing expression or recognition of antigen(s) on the sympathetic neuron.

Animals↗
PubMed1983

The effects of a communication task upon the representation of depth relationships in young children's drawings.

Attempts to represent the occlusion of a farther object by a nearer one are infrequent in young children's drawings. Instead they typically draw the objects side by side or one above the other. This does not appear to reflect a limitation of skill, but rather a concern with the array of objects per se as opposed to the child's own particular view. Two experiments are reported which attempt to assess children's ability to produce view-specific drawings by creating a context that clearly demands such drawings. In a "communication game," drawings were produced by one child so that another could identify the chair he had been sitting on. In a first experiment, compared to a control condition this game produced significantly more view-specific drawings from 7- and 8-year-olds, but not from 5- and 6-year-olds. A second experiment with 5- and 6-year-olds was also ineffective in promoting view-specific drawings at this age.

Age Factors↗
PubMed1982

Children and nocturnal snoring: evaluation of the effects of sleep related respiratory resistive load and daytime functioning.

Twenty-five children, age range 2 to 14 years (mean age = 7), were referred to the Stanford University Sleep Disorders Clinic for various clinical symptoms, including excessive daytime somnolence, heavy nocturnal snoring, and abnormal daytime behavior. All children (10 girls and 15 boys) were polygraphically monitored during sleep. No sleep apnea syndrome or oxygen desaturation was revealed. However, each child presented significant respiratory resistive load during sleep associated with electrocardiographic R-R interval and endoesophageal pressure swings. The most laborious breathing occurred during REM sleep. Second degree atrioventricular blocks were also noted. Tonsillectomy and/or adenoidectomy was performed in every case and resulted in a complete disappearance or substantial amelioration of the reported symptoms. Objective evaluation by Multiple Sleep Latency Test and Wilkinson Addition Test confirmed the beneficial effect of surgery.

Adenoidectomy↗
PubMed1977

Mechanical properties of tracheal smooth muscle: effects of temperature.

The effect of temperature on the isometric tetanic myogram was studied in isolated canine tracheal smooth muscle (TSM). At 37 degrees C and 27 degrees C no significant change occurred in maximum tetanic tension (PO). At 17 degrees C a significant reduction was seen Values of Q10 for contraction time (tPO) were almost halved, whereas those for rate of tension development (dP/dt) were almost doubled. The effect of the same temperatures on the force-velocity (F-v) relationships was also studied. All three F-v curves were described by the Hill equation, (P + a) (v + b) = (PO + a)b. Vmax and b decreased with decreased temperature, with Q10's demonstrating they were dependent on active processes. Finally, the decreased dP/dt of the myogram at lower temperatures was felt to be the probable result of decreased contractile element velocity because no decrease in series elastic component stiffness was demonstrable, there being instead an increase in stiffness at lower temperatures.

Animals↗