Dietary calcium intake and bone loss from the spine in healthy postmenopausal women

Controversy exists over the relationship between calcium intake and axial bone loss. We measured bone density of the spine (L2-4) by dual photon absorptiometry (DPA) two times, 7 mo apart, in 76 healthy postmenopausal women aged 40-70 y. Ca intake was assessed by food-frequency questionnaire. Women with a Ca intake less than 405 mg/d lost spine density at a rate that was significantly greater than that of women with an intake greater than 777 mg/d, p = 0.026. There appears to be a threshold of Ca intake below which increased Ca in the diet is likely to be beneficial in reducing spine mineral loss.     

Precision of dual-photon absorptiometry

Summary Precision of dual-photon absorptiometry (DPA) measurements was determined in a lumbar spine phantom and in humans. Approximately half of the measurements were made before and half after a¹⁵³gadolinium source change. The phantom was measured with different amounts of acrylic, which simulates human soft tissue, in order to evaluate the influence of body thickness on bone mineral density (BMD). Results of scans analyzed with two software versions from Lunar Radiation Corp., the widely used 08B and a prototype 08C, are compared. DPA with a cold source significantly overestimated BMD in the phantom in the presence of large amounts (more than 25 cm) of soft tissue equivalent with version 08B but not with the newer version 08C. Similiarly, in nine subjects, there was a significant decrease in spine BMD after a source change when scans were analyzed with version 08B (mean difference 0.026 g/cm²,P=0.002) but not with 08C (0.01 g/cm²,P=0.234). No systematic effect of source change on femoral BMD measurements was observed. The SD of the mean difference of two measurements of the nine subjects was 0.019 g/cm² (1.6% of the mean value) for the spine with software version 08B and 0.024 g/cm² (2.0%) with version 08C, 0.03 g/cm² (3.3%) for the femur neck, 0.03 g/cm² (4.0%) for the greater trochanter, and 0.04 g/cm² (4.9%) for Ward's triangle region of the proximal femur. The spine phanton was scanned on two other commercial bone densitometers in order to assess inter-instrument variation. Phantom measurements of L2-4 BMD made on two Lunar Radiation Corp model DP3 scanners which differed by 2% were 10 and 12% higher than those with a Norland Corp. model 2600 scanner.     

1987 survey of military optometrists: activities, roles and attitudes

A worldwide survey of active duty military optometrists (Air Force, Army and Navy) was conducted in the spring of 1987. The survey response rate was 79%. Statistically significant differences (alpha = 0.01) in their roles, activities and attitudes are presented and discussed. Significant interservice differences were found in: types of duties, profession/status of immediate supervisors, work assignments, frequency and types of patient encounters, awareness of therapeutic drug policies, access to specific clinical instruments, and frequency of routine clinical tests. Attitude and opinion tabulations suggest an overall satisfaction with professional experiences and interprofessional working relationships. However, there was a common perception that optometrists did not receive appropriate promotional consideration or career opportunities within this multidisciplinary setting. Implications of survey results for non-military multidisciplinary health care institutions are also discussed.     

Reduced high-energy phosphate levels in rat hearts. I. Effects of alloxan diabetes.

Significant alterations in heart carbohydrate and lipid metabolism are present 48 h after intravenous injection of alloxan (60 mg/kg) in rats. It has been suggested that uncoupling of oxidative phosphorylation occurs in the alloxanized rat heart in vivo, whereas normal oxidative metabolism has been demonstrated in alloxan-diabetic rat hearts perfused in vitro under conditions of adequate oxygen delivery. We examined the hypothesis that high-energy phosphate metabolism might be adversely affected in the alloxan-diabetic rat heart in vivo. Phosphocreatine and ATP were reduced by 58 and 45%, respectively (P is less than 0.001). Also, oxygen-dissociation curves were shifted to the left by 4 mmHg, and the rate of oxygen release from blood was reduced by 21% (P is less than 0.01). Insulin administration normalized heart high-energy phosphate compounds. ATP production was accelerated in diabetic hearts perfused in vitro with a well-oxygenated buffer. These studies support the hypothesis that oxidative ATP production in the alloxan-diabetic rat heart is reduced and suggest that decreased oxygen delivery may have a regulatory role in the oxidative metabolism of the diabetic rat heart.     

Giardia lamblia produces alanine anaerobically but not in the presence of oxygen

Proton nuclear magnetic resonance was used to follow glucose metabolism in Giardia lamblia. Under strictly anaerobic conditions this organism produces equimolar ethanol and alanine as well as CO2 and some acetate. Aerobically the production of both alanine and ethanol are inhibited and more acetate and CO2 are formed. These changes in the balance of products are reversible over the range 0-46 microM O2. In the presence of 46 microM O2, alanine was not detectable. The O2-sensitivity of alanine production may highlight the necessity for redox-balancing reactions in an organism exposed in situ to fluctuating concentrations of O2.     

A comparison of the Charlson comorbidity index derived from medical record data and administrative billing data

The objective of this article is to compare the Charlson comorbidity index derived from medical record data (Chart Index) with the same index derived from billing data (ICD-9 Index) to determine how well each predicted inpatient and 30-day mortality, length of stay, and complications among Medicare beneficiaries hospitalized for carotid endarterectomy. Economic and time constraints have increased the need for risk adjusters derived from administrative data, yet few studies have compared these measures with those derived from chart review. Using logistic regression, the Chart Index was found to be a significant predictor of inpatient mortality, 30-day mortality, length of stay, and complications, after controlling for age, gender, and neurologic and medical risk factors (P values = 0.004, 0.056, 0.0001, and 0.042, respectively). The ICD-9 Index approached significance as a predictor of the outcomes (P values = 0.092, 0.100, 0.093, and 0.080, respectively). The Chart Index was shown to be superior to the ICD-9 Index within this patient sample.     

Identification of major prognostic subgroups of patients with large-cell lymphoma treated with m-BACOD or M-BACOD

One hundred twenty-one patients with diffuse large-cell lymphoma treated with m- or M-BACOD (methotrexate, bleomycin, doxorubicin, cyclophosphamide, vincristine, and dexamethasone) were evaluated for pretreatment characteristics predictive for response and survival. Two characteristics, poor performance status and massive bulky disease, were negatively associated with response rate in a multivariate analysis. These two characteristics were also negatively associated with survival in multivariate analysis, as was another factor, an increased number of extranodal sites of disease. These three pretreatment characteristics were used to construct a model containing 12 categories of patients at increasing risk for relapse and shortened survival. These categories divided naturally into three broad groups of patients with respective 5-year survival rates of 68%, 55%, and 24%.     

Drug enterocyte adducts: possible causal factor for diclofenac enteropathy in rats

BACKGROUND & AIMS: Enteropathy is a frequent complication of diclofenac and other nonsteroidal anti-inflammatory drugs, yet little is known about the underlying mechanism. One possibility is that reactive metabolites of diclofenac form adducts with enterocyte macromolecules, as previously shown for liver. We addressed this possibility by using immunohistochemistry to detect diclofenac adducts. METHODS: Rats were treated orally with diclofenac (10-100 mg/kg) and killed after 1-24 hours, and their gastrointestinal (GI) tracts were evaluated for ulcer number and area. Adduct distribution and intensity were assessed by immunohistochemistry by using a technique to simultaneously process and stain multiple intestinal rings. RESULTS: Drug treatment led to dose-dependent formation of both adducts and ulcers only in small intestine and only in animals with intact enterohepatic circulation. Adducts formed within enterocytes by 1 hour, translocated to the brush border, preceded ulceration and vascular protein leakage, and were intense at sites of ulceration. Adducts and ulcers exhibited a parallel distribution within intestinal quintiles: 3rd > 5th > 1st. CONCLUSIONS: Diclofenac treatment resulted in the formation of drug adducts in enterocytes. Because this molecular change occurred before ulceration, was dose dependent, and exhibited concordant distribution with extent of ulceration, the results suggest a causal role for drug adduct formation in diclofenac enteropathy.     

Synthesis and Biological Evaluations of Electrophilic Steroids Inspired by the Taccalonolides

Natural products have served as inspirational scaffolds for the design and synthesis of novel antineoplastic agents. Here we present our preliminary efforts on the synthesis and biological evaluation of a new class of electrophilic steroids inspired by the naturally occurring taccalonolides. We demonstrate that these simplified analogs exhibit highly persistent antiproliferative properties similar to the taccalonolides and retain activity against resistant cancer cell lines that warrants further preclinical development.