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Biomedical subjects

R L Bauer

Publications and source records attributed to R L Bauer.

At least 19 recordsLinked to original sources
PubMed2004

Bone mineral density, carotid artery intimal medial thickness, and the vitamin D receptor BsmI polymorphism in Mexican American women.

Low bone mineral density (BMD) is a predictor of cardiovascular mortality, suggesting that osteoporosis and cardiovascular disease may share common risk factors. We assessed the relationship between BMD and intimal medial thickening (IMT) of the common carotid artery, a marker of sub-clinical atherosclerosis, in 471 women examined as part of the San Antonio Family Osteoporosis Study, a population-based study of osteoporosis risk conducted in Mexican American families. Because of the documented role of vitamin D metabolism in bone metabolism and its possible role in cardiovascular function, we further evaluated whether allelic variation at the vitamin D receptor locus (VDR) influenced joint variation in BMD and IMT. The association of BMD with IMT depended on age, with low BMD being correlated with high IMT in older women, but with low IMT in younger women [age by IMT interaction effects significant at the spine (P = 0.042), radius ultradistal (P = 0.010), and hip (P = 0.006)]. In all women, the VDR BsmI BB genotype was associated with significantly higher forearm BMD (P = 0.005 for both radius ultradistal and midpoint), higher IMT (P = 0.05), and higher spine BMD in older women (P = 0.06), but not with hip BMD. The association of the VDR genotype with IMT was independent of its association with BMD. Although a functional consequence of the BsmI polymorphism on vitamin D metabolism has not been established, these findings support a possible biological relationship among VDR, bone metabolism, and atherosclerosis. We conclude that VDR polymorphisms may be one of multiple factors influencing the joint risk of atherosclerosis and osteoporosis.

Adult↗
PubMed2000

Genes influencing variation in serum osteocalcin concentrations are linked to markers on chromosomes 16q and 20q.

Osteocalcin (OC) is an important constituent of bone that is synthesized by osteoblasts. Serum levels of OC have been used as a biochemical marker of bone turnover. To identify the genes influencing variation in serum OC levels, we conducted a genome-wide scan in 429 individuals comprising 10 large multigenerational families. OC levels were measured by immunoassay, and genetic markers were typed at approximately 10-cM intervals across the genome. Quantitative trait linkage was tested using a multipoint analysis based on variance component methodology, adjusting for the effects of age, sex, and oral contraceptive use. Significance levels for linkage were obtained empirically, by Monte Carlo simulation. The heritability of OC levels in this population was 62 +/- 8%. We detected significant evidence for linkage between a quantitative trait locus influencing serum OC levels and markers on chromosome 16q, and suggestive evidence for linkage of OC levels with markers on chromosome 20q. The multipoint lod scores peaked at 3.35 on chromosome 16 and 2.78 on chromosome 20, corresponding to P values of 0.00004 and 0.00017, respectively. A potential candidate gene for bone formation in the linked region on chromosome 20 is CDMP1, which encodes cartilage-derived morphogenetic protein 1. Future studies should evaluate whether variation in CDMP1 or in other genes in the linked regions on chromosomes 16 and 20 influence the rate of bone turnover.

Adolescent↗
PubMed1998

Lobular carcinoma in situ with microinvasion.

Six patients with lobular carcinoma in situ with microinvasion were described in this report. Lobular carcinoma in situ is not known to progress to microinvasive disease. Although this feature is rare, the current under standing that lobular carcinoma in situ is a marker needs to be revised.

Adult↗
PubMed1997

Comparison of histologic diagnosis between stereotactic core needle biopsy and open surgical biopsy.

BACKGROUND: This study correlates the histologic findings of stereotactic core needle biopsy (SCNB) with open surgical biopsy (OSB) and identifies which lesions can be treated definitively based only on the SCNB histology. METHODS: Women who underwent SCNB between July 1, 1993, and January 1, 1969, were identified by retrospective chart review. Mammographic (MGM) lesions found by SCNB to be ductal or lobular hyperplasia with atypia, or carcinoma underwent OSB. When the histologic findings by SCNB were inconsistent with the MGM findings, the lesion also underwent OSB. RESULTS: 799 women underwent SCNB with 96 (12%) of these going on to OSB. MGM findings in the 92 who presented without a palpable mass included microcalcifications (MCS) in 39, mass in 47, MCS and mass in 7, and tissue distortion in 3. One hundred one breast lesions biopsied first by SCNB, then by OSB were correlated histologically. Sensitivity of SCNB is 89%, with a specificity of 94%. Eight-four women (88%) were able to have definitive treatment at time of OSB because of prior SCNB, and 703/799 (88%) of women were spared OSB entirely. CONCLUSION: SCNB accurately identifies benign breast histology and invasive cancers in women with MGM abnormalities, a distinct advantage over fine needle aspiration cytology. SCNB does not reliably identify women with DCIS and invasion. All women with SCNB diagnosis of ductal or lobular atypia should also undergo OSB.

Adult↗
PubMed1997

The effect of an ambulatory internal medicine rotation on students' career choices.

PURPOSE: To assess the effect of an ambulatory care experience on medical students' perceptions of internal medicine and their choices of careers (as measured by residency selections). METHOD: In 1990-91, the 196 third-year students enrolled in the 12-week internal medicine clerkship at the University of Texas Medical School at San Antonio were randomized to a curriculum that included a three-week ambulatory care component or to a traditional, exclusively inpatient curriculum. The ambulatory curriculum included the evaluation of walk-in-patients, exposure to community internists, and a lecture series. The students' perceptions of internal medicine were surveyed before and after the clerkship. Their career choices were determined by their residency selections at graduation. Data analysis employed chi-square tests, t-tests, and logistic regression. RESULTS: Of the 196 students, 184 (76 in the ambulatory and 108 in the traditional curricula) provided complete data. The ambulatory care students were somewhat more likely to enter an internal medicine residency (odds ratio = 1.49; 95% CI, 0.72 to 3.09) than were the traditional students. The ambulatory care students' perceptions of internal medicine did not change significantly from before to after the clerkship. CONCLUSION: The ambulatory curriculum had a modest but favorable effect on the students' selections of careers in internal medicine, but was not associated with changes in their perceptions of internal medicine.

Ambulatory Care↗
PubMed1995

Therapy for inflammatory breast cancer: impact of doxorubicin-based therapy.

BACKGROUND: Inflammatory breast cancer (IBC) carries an ominous prognosis. Before 1988, women with IBC at our institution were treated with neoadjuvant cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) with or without vincristine and prednisone (CMF/VP). After 1988, women with IBC were treated with cyclophosphamide, doxorubicin, and 5-fluorouracil (FAC). This study compares these two regimens with regard to response and survival. METHODS: The records of all women presenting between January 1973 and December 1991 with a stage IIIB (T4d, any N, MO) breast cancer with proven dermal lymphatic invasion by tumor cells were reviewed retrospectively. RESULTS: The study comprised 38 women; 28 received CMF (22 CMF, 6 CMF/VP), and 10 received FAC. The overall response rate to induction chemotherapy in the CMF/VP group was 57% (40% PR, 17% CR), and 100% (60% PR, 40% CR) in the FAC group. The median overall survival for women receiving CMF/VP was 18 months compared with 30 months for women receiving FAC (p = 0.02). The median disease-free survivals for the CMF/VP and FAC groups were 6 and 24 months, respectively (p < 0.001). When comparing responders and nonresponders with CMF/VP induction therapy, the responders had a significantly longer overall median survival (24 versus 10 months) (p < 0.001) and disease-free median survival (8 versus 2 months) (p < 0.001). All of the five patients remaining alive received FAC with 80% (four of five) having a complete response. These four patients subsequently underwent mastectomy and radiation. CONCLUSION: This study suggests that a doxorubicin-containing chemotherapy regimen improves overall and disease-free median survivals when compared with the previously used CMF combination in the treatment of IBC. A favorable response to induction chemotherapy also appeared to be associated with an improved survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Adenocarcinoma of the small intestine: 21-year review of diagnosis, treatment, and prognosis.

BACKGROUND: The purpose of this study was to evaluate the tumor characteristics and treatment associated with an improved overall survival in patients with adenocarcinoma of the small intestine. METHODS: The records of all patients with primary adenocarcinoma of the small bowel seen between January 1971 and December 1991 were reviewed retrospectively. The study comprised 38 patients, 22 (58%) with duodenal tumors, 11 (29%) with jejunal tumors, and five (13%) with ileal tumors. RESULTS: Although not statistically significant, the patients with duodenal adenocarcinoma lived longer than the patients with jejunal or ileal lesions (p = 0.77). The overall survival was 23% and seemed to correlate best with absence of lymph node metastases (p = 0.04) and pancreaticoduodenectomy for localized duodenal tumors (p = 0.04). The patient's age, duration of symptoms, disease-free interval, tumor location, type of recurrence, and histologic grade did not significantly influence survival. CONCLUSIONS: The lethality of small-intestinal adenocarcinoma appears to be related to a delay in diagnosis and treatment. When a definitive surgical procedure is performed before lymph node metastases appear, the patient's chance for long-term survival is greatly improved.

Adenocarcinoma↗
PubMed1993

The association of obesity and glucose and insulin concentrations with bone density in premenopausal and postmenopausal women.

Obese subjects have increased bone density relative to non-obese subjects, yet this relationship is not fully understood. We examined whether alterations in glucose or insulin concentrations might explain the effect of obesity on bone density in 317 women from the San Antonio Heart Study, a population-based study of diabetes. We measured fasting and 2-hour plasma glucose and fasting and 2-hour serum insulin levels. Bone density was assessed by a Hologic dual-photon absorptiometer. Lumbar spine and femoral neck density were positively correlated with body mass index (BMI). Femoral neck density also was positively correlated with fasting insulin level in younger women after adjustment for age (r = .214, P < .01). After further adjustment for BMI, femoral neck density was not significantly correlated with fasting insulin level (P = .08). The magnitude of the estimated femoral neck density difference for a 32.2-microU/mL decrease in fasting insulin level (the difference in insulin concentrations between nondiabetics and diabetics) was 0.13 g/cm2. Adjustment for glucose and insulin concentrations does not explain the association between bone density and obesity.

Adult↗
PubMed1992

Excess androgenicity only partially explains the relationship between obesity and bone density in premenopausal women.

Obese subjects have increased bone density relative to non-obese subjects yet this relationship is not fully understood. We examined whether alterations in sex hormones or binding proteins might explain the effect of obesity on osteoporosis in 83 premenopausal women from the San Antonio Heart Study, a population-based study of diabetes. We measured total testosterone, oestradiol, oestrone, sex hormone binding globulin (SHBG), and serum dehydroepiandrosterone sulphate (DHEA-SO4). Bone density was assessed by a Hologic dual photon absorptometer. Lumbar spine and femoral neck density were positively correlated with body mass index (BMI). In addition, femoral neck density was positively correlated with DHEA-SO4. BMI was negatively correlated with SHBG. After adjustment for sex hormones by multiple linear regression a positive association between bone density and obesity still exists suggesting that the association between obesity and bone density is at least partially independent of sex steroids in premenopausal women.

Adult↗
PubMed1990

Impact of legal liability, family wishes, and other "external factors" on physicians' life-support decisions.

PURPOSE: The purpose of this study was to determine the impact of external factors on physicians' life-support decisions. "External factors" are those factors that promote the interests of people other than the patient. Examples of external factors include physician legal liability and family wishes about patient care. SUBJECTS AND METHODS: A nationwide sample consisted of 300 randomly selected physician-members from the American Society of Law and Medicine (ASLM) and 300 from the Society for Critical Care Medicine (SCCM); 179 ASLM physicians (60%) and 165 SCCM physicians (55%) responded. A mailed questionnaire presented three cases, each requiring the physician to make a life-support decision. For each case, the physician chose one of several life-support options and rated the importance to his or her decision of specific "decision factors," including some external factors. We assumed the physician would choose the management option supported by the decision factors that the physician considered most important. For this reason, we used discriminant analysis to identify the factors whose importance ratings best predicted management choices. RESULTS: In the first case, 46% of ASLM respondents and 55% of SCCM respondents chose to stop the ventilator of a chronically comatose patient with unknown preferences about life support. Thirty-one percent of ASLM and 27% of SCCM respondents chose to continue the ventilator, and 21% of ASLM and 14% of SCCM respondents chose to apply for a judicial decision. Importance ratings for the external factor, physician legal liability, best predicted management choices. In the second case, 95% of ASLM and 94% of SCCM respondents chose to resuscitate a cancer patient at the patient's request; 3% of ASLM and 4% of SCCM respondents chose no resuscitation. Importance ratings for patient preferences best predicted management choices. In the third case, 38% of ASLM and 35% of SCCM respondents honored a stroke patient's previous refusal of tube feedings, but 59% of ASLM and 62% of SCCM respondents authorized tube feedings in order to secure nursing home placement. Importance ratings for patient preferences best predicted management choices in this case. External factors impacted management choices considerably in the first case and more modestly in the second and third cases. CONCLUSION: External factors impact the life-support decisions of physicians. Physician legal liability may have an especially great impact on these decisions when patients' preferences are not known.

Decision Making↗
PubMed1988

Ethnic differences in hip fracture: a reduced incidence in Mexican Americans.

To confirm a previous report of lower risks of hip fracture in Mexican Americans, we calculated the incidence of hip fractures among Hispanics, blacks, and non-Hispanic whites residing in Bexar County, Texas, during 1980. A total of 576 residents with hip fracture not due to severe trauma were identified. The 1980 census data were used to calculate ethnic-specific incidence rates which were age-adjusted using the entire 1980 US population as the standard. Hip fractures were more common among non-Hispanic white women (139 per 100,000; 95% confidence interval (CI) = 124-153) than among Mexican-American (67 per 100,000; 95% CI = 51-82) or black (55 per 100,000; 95% CI = 27-83) women. Thus, Mexican Americans and blacks are relatively protected from hip fractures, and they may benefit less than whites from prophylactic therapies for osteoporosis.

Adolescent↗
PubMed1987

Correlates of medication compliance in non-insulin-dependent diabetes mellitus.

Maintaining compliance with medications is important in the management of patients with non-insulin-dependent diabetes mellitus. We examined correlates of medication compliance in 77 patients followed up prospectively for 24 weeks. Of the demographic, socioeconomic, and clinical variables examined, only older age and greater education were related to compliance. While statistically significant, the differences observed were small and unlikely to be useful to clinicians. Factors reflecting the process of care, including frequency of appointments, minutes spent with the provider, and patient satisfaction were not related to compliance. Symptoms associated with poor glucose control and fasting glucose levels were also not significantly related. The patient's report of his own compliance, however, was strongly associated with our independent measures of medication taking. We conclude that rather than attempting to predict compliance from sociodemographic characteristics, symptoms, or glucose values, the physician should directly inquire about medication taking in a nonthreatening manner.

Age Factors↗
PubMed1987

Low risk of vertebral fracture in Mexican American women.

Ethnicity is important in assessing risk for osteoporotic fractures, and should be considered in decision-making about the use of prophylactic treatments. Few data are available, however, on fracture risks among Hispanic patients. To assess the risk of vertebral fracture in Mexican Americans, we determined the prevalence of vertebral fracture among 822 patients, aged 15 to 86 years, who underwent spinal roentgenography in a study of low-back pain. After adjusting for age, use of steroids, drug or alcohol abuse, and recent trauma, the odds ratio for Mexican American women compared with non-Hispanic whites was 0.55 (95% confidence interval, 0.32 to 0.95), indicating a substantially lower risk. These results are concordant with earlier data documenting a reduced risk of hip fracture among Mexican American women. Thus, recommendations for prophylactic treatments for osteoporosis may be different for Mexican Americans than for non-Hispanic whites.

Adult↗
PubMed1986

Area variation in mortality from diseases amenable to medical intervention: the contribution of differences in morbidity.

Several conditions, whose timely and appropriate therapy should decrease case fatality, have been proposed as indicators of medical care quality for the National Health Service. Mortality rates for these diseases vary widely within the UK. To evaluate the contribution of varying incidence rates to these mortality differences, routinely collected morbidity and mortality data for 1974-1978 were analysed for 98 Area Health Authorities (AHAs) in England and Wales. Although differences in morbidity (as measured by hospital discharge and disease registration rates) and socioeconomic factors account for some of the area variation in mortality, significant heterogeneity persists after these factors are taken into account. This finding suggests that morbidity and socioeconomic factors are not the only determinants of mortality variation among areas for these particular diseases. Variation in quality of medical care may account for this result, although regional diagnostic and reporting differences and variation in disease severity among areas must also be considered.

Analysis of Variance↗
PubMed1986

Private physicians in ambulatory care training in U.S. medical schools.

The contribution of private physicians to medical student education in ambulatory care was determined by a questionnaire directed to departments of family practice, internal medicine, and pediatrics in 124 U.S. medical schools and their branch campuses. The response rate was 84 percent. Of the responding departments, 82 percent offered an ambulatory care course in curricular years three and/or four, and 56 percent utilized private physicians in their courses. Departments of internal medicine were least likely to offer such a course, and their courses less frequently included teaching by private physicians (p less than 0.0001). When offered, internal medicine courses in ambulatory care were least likely to be required for graduation and involved the fewer students. Departments of family practice were most likely to offer ambulatory care courses and were most likely to utilize private physicians in their courses.

Ambulatory Care↗
PubMed1986

Risk of postmenopausal hip fracture in Mexican American women.

To assess the risk of hip fracture in Mexican Americans, the ethnicity of 80 women aged 50 years and over admitted with hip fractures to a Texas hospital was compared with that of age-matched women hospitalized for other reasons. The risk of fracture for Mexican Americans was only 35 per cent that of Whites (95% CI = 19 per cent, 65 per cent). This finding was confirmed in a chart survey performed in a second hospital population. These results suggest that Mexican American women may receive less potential benefit from preventive measures for hip fracture than Whites.

Aged↗