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Biomedical subjects

D E Meier

Publications and source records attributed to D E Meier.

16 recordsLinked to original sources
PubMed1992

Combined carotid-vertebral arterial trauma.

Eight patients with simultaneous penetrating trauma to the carotid and vertebral arteries among 129 carotid and 53 vertebral arterial injuries have been treated in the last 14 years. In contrast to a 10% mortality with isolated carotid or vertebral trauma, the mortality associated with this injury complex was 50%. This high mortality directly related to the overall complexity of the trauma sustained by these patients. The liberal use of arteriography to assess penetrating cervical trauma has enhanced the diagnosis of these injuries. We recommend simultaneous surgical management of the carotid and vertebral arterial injury through an extended anterior cervical approach.

Angiography↗
PubMed1992

Racial differences in pre- and postmenopausal bone homeostasis: association with bone density.

The disparity in fracture incidence and bone mass in women of European (white) and African (black) ancestry is of unknown etiology. To determine if racial differences in bone mass reflected racial differences in the mechanisms of bone turnover underlying bone mineral loss, we measured serum osteocalcin, serum alkaline phosphatase, fasting urinary calcium and hydroxyproline excretion, 24 h urinary excretion of calcium and sodium, and dietary intakes of calcium and vitamin D in 263 healthy pre-, peri-, and postmenopausal white and black women. In addition, radial and spinal bone density were measured cross-sectionally for comparison with biochemical measures of bone turnover. The biochemical parameters thought to reflect bone resorption (fasting urinary calcium and hydroxyproline excretions) were lower in black than in white women throughout the age and menopausal stages studied. The parameters thought to reflect bone formation (alkaline phosphatase and osteocalcin), were similar in the two racial groups among the premenopausal women, but osteocalcin was significantly lower among the peri- and postmenopausal blacks. Cross sectionally measured radial bone density increased with age in premenopausal black women, but it did not change with age in the white premenopausal subjects, a statistically significant difference. In peri- and postmenopausal women radial density declined significantly with years after menopause in both racial groups, but the rate of decline was significantly slower in the black women. Lumbar bone density in premenopausal white and black women did not change with age. After menopause lumbar bone density declined significantly and similarly in both racial groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Substituted judgment: how accurate are proxy predictions?

Substituted judgment has been proposed as a method of promoting the autonomy of the mentally incapacitated patient, but little is known about the accuracy of surrogate decision makers in reflecting the true wishes of patients. In this study, surrogate decision makers' views (those of primary care providers and close family members) were compared with the decisions of currently competent chronically ill elderly patients, using a hypothetic cardiopulmonary resuscitation scenario under circumstances of current health and progressive dementia. Concordance between patients and their surrogates was evaluated by assessing percent agreement, kappa coefficient (for concordance beyond chance), and directionality of discrepant responses. Most patient respondents chose to be resuscitated in both scenarios. Although patients predicted that both their physicians (90%) and family members (87%) would accurately represent their wishes, neither family members nor physicians, in fact, were able to adequately predict patients' wishes in both scenarios (kappa less than or equal to 0.3 in all scenarios; percent agreement range, 59% to 88%). Few patients had ever discussed their resuscitation preferences with either their family member (16%) or their physician (7%). These results cast doubt on the usefulness of a strict substituted judgment standard as an approach to medical decision making for patients with diminished mental capacity.

Aged↗
PubMed1991

Calcium, vitamin D, and parathyroid hormone status in young white and black women: association with racial differences in bone mass.

The etiology of the racial disparity in bone mass and fracture rate is unknown. Since the PTH-vitamin D endocrine system is a major regulator of calcium metabolism and bone turnover, this cross-sectional study examined the relationship of radial and lumbar bone density to vitamin D metabolite and PTH concentrations and to calcium intake and excretion in 67 white and 70 black highly comparable, healthy, premenopausal women. Bone density at both radial and lumbar sites was higher in blacks than in whites. Serum 25-hydroxyvitamin D was slightly but not statistically significantly (P = 0.08), lower in blacks than in whites, but there were no racial differences in 1,25-dihydroxyvitamin D, PTH, or renal tubular maximum for reabsorption of phosphate. The mean 25-hydroxyvitamin D concentration in blacks was well within the normal range and was not associated with evidence of secondary hyperparathyroidism. There were no correlations of bone density to vitamin D or PTH concentrations. Although there were no racial differences in dietary intake of calcium and vitamin D or in sodium excretion, 24-h urinary calcium excretion was significantly lower in blacks than in whites, and calcium excretion was inversely associated with radial bone density. In contrast to previous reports, in healthy, normal weight, premenopausal black women there is no evidence of vitamin D deficiency or secondary hyperparathyroidism, suggesting that factors other than the vitamin D-PTH axis are responsible for racial differences in bone mass.

Adult↗
PubMed1989

Perforated typhoid enteritis: operative experience with 108 cases.

A retrospective review of 108 consecutive patients with perforated typhoid enteritis managed operatively over a 4-year period at Baptist Medical Centre, Ogbomoso, Nigeria is presented. There were 75 males and 33 females with an average age of 19.7 years. Presenting symptoms were fever, abdominal pain, vomiting, and either diarrhea or constipation. One hundred patients (93 percent) underwent debridement of the perforation and two-layer bowel closure. Postoperative morbidity included intraabdominal abscess, wound dehiscence, and subsequent bowel perforation. Most of the 35 deaths (32 percent mortality) were attributed to overwhelming sepsis which progressed despite aggressive operative management and antibiotic administration. The key to improved survival in this deadly disease lies not in a better operation or improved perioperative care but in the prevention of typhoid fever by providing safe drinking water and improved sanitation methods for all of the global community.

Adolescent↗
PubMed1989

Radial and vertebral bone density in white and black women: evidence for racial differences in premenopausal bone homeostasis.

The reasons for a different incidence of osteoporotic fractures in white and black women are unknown. Previous racial comparisons of bone mass have been limited by racial differences in body weight and socioeconomic, health, and nutritional status. This cross-sectional study examined bone density in 105 black and 114 white healthy nonobese women, 24-65 yr old, using dual photon absorptiometry of the lumbar spine and single photon absorptiometry of the distal radius. Bone density at both sites was higher in blacks at all ages than in whites. When adjusted for age and body mass index, mean bone density was 6.5% higher in blacks at both spine and radius (P less than 0.0001). The cross-sectional rate of decline of vertebral bone density was similar between races; however, radial density increased 3.8%/decade (P = 0.03) in premenopausal blacks under age 46 yr, while it declined 3.2%/decade (P = 0.09) in premenopausal whites. The racial difference in slopes in these premenopausal women is significant (P = 0.002). These findings suggest that attainment of higher peak bone mass and delayed onset of bone loss contribute to the lower incidence of osteoporotic fractures in black women.

Adult↗
PubMed1989

Effect of source strength and attenuation on dual photon absorptiometry.

A systematic error in dual photon absorptiometry (DPA) measurements of bone mineral density (BMD) related to source strength has been previously described and attributed to an erroneous algorithm for deadtime correction. Since detected counts (or photon flux) is a product of source strength and attenuation, the effect of various source activities and attenuation depths on BMD calculations were evaluated using a phantom. Ten DPA scans were acquired at two source strengths, 0.3 and 1.0 Ci, and at each of two water depths, 16.4 and 24.5 cm. These activities and depths are within the range encountered clinically. Scans were acquired and processed using a commercially available lumbar spine scanner and software, and were reanalyzed with two upgraded versions of software. Mean BMD obtained with the initial software varied by 2 to 14% with changes in both sources strength and attenuating depth. Software revisions reduced but did not entirely eliminate these differences. The remaining 6% discrepancy is of sufficient magnitude to influence both patient management and research investigations.

Absorptiometry, Photon↗
PubMed1987

Diagnosis of penetrating cervical esophageal injuries.

Arterial injuries pose the greatest early threat to the patient with penetrating neck trauma and esophageal injuries, the greatest late threat. Clinical evaluation reliably identifies 80 percent of esophageal injuries, which, in our opinion, is not adequate. In 118 minimally symptomatic or asymptomatic patients with penetrating neck trauma, the combination of esophagography with esophagoscopy identified all 10 esophageal injuries in 118 patients with penetrating neck trauma. These data suggest that patients with penetrating neck trauma and minimal clinical findings should be initially evaluated with arteriography and esophagography. If the results of arteriography or esophagography are positive, then neck exploration should be performed. If the results of esophagography are equivocal, then rigid esophagoscopy should be performed. If all test results are negative, then observation is justified.

Adult↗
PubMed1987

Serum protein concentrations and bone mineral content in aging normal men.

Low serum protein levels and low dietary protein intakes possibly influence bone metabolism. To evaluate the relationships among serum protein concentrations, protein intakes, and bone mineral content (BMC), we have examined two populations of normal men. BMC was measured at two radial sites and a vertebral site. Aging was associated with a fall in BMC at all sites. Serum albumin levels also fell with age and were related to BMC. Albumin concentrations were associated with BMC when other variables (calcium and protein intake, vitamin D levels, parathyroid hormone, and urinary calcium) also were considered. Thus, alterations in protein metabolism may affect BMC and may play a role in the genesis of senile osteopenia.

Adult↗
PubMed1986

Selected bibliography of recent articles in ethics and geriatrics.

The disciplines of bioethics and geriatrics have had parallel development in recent years. From small and relatively esoteric fields 15 or 20 years ago, both have grown enormously. Although the numbers of geriatricians and ethicists in practice or in academic centers have increased substantially, these disciplines represent areas in which better understanding is sorely needed. This bibliography is intended to assist the clinician in locating salient literature concerning bioethical issues in geriatric medicine and research. It is highly selective; it does not attempt to cover all the literature on bioethics. There are several excellent general bioethics bibliographies for clinicians in the recent literature, as well (not limited to clinical journals or clinical topics), some of which are included in section 13 for the reader's further information. The ethical issues that arise in geriatric medicine are similar to those that arise in the care of younger patients, but certain kinds of problems happen with far greater frequency. Dilemmas concerning decisions about care at the end of life are particularly relevant in geriatrics, as persons of extreme old age are often presented with choices about life-sustaining therapy when critical illness occurs. This includes decisions about cardiopulmonary resuscitation and nutritional support. When these clinical decisions arise in the care of patients who cannot decide for themselves, the question arises as to what role the assessment of "quality of life" ought to play in decisions to pursue or to forego life-sustaining therapy. Informed consent to treatment and to participation in research has been an important area of ethical investigation. Dilemmas about consent to treatment are complicated in some elderly populations because of the higher incidence of cognitive impairment and the higher incidence of the clinician's suspicion (or assumption) of cognitive impairment. In consent to research, there are additional issues of voluntariness and equitable selection, especially when subjects are residents of nursing homes. Because of the increasing numbers of elderly persons in our society, and because of the role of social resources (federal, state, and local) in acute and long-term medical major concern in gerontologic bioethics. The topic headings for this bibliography reflect these common issues which arise in the care of the elderly.+2

Bibliographies as Topic↗
PubMed1986

Alterations in calcium, vitamin D, and parathyroid hormone physiology in normal men with aging: relationship to the development of senile osteopenia.

The effects of aging on calcium and bone metabolism have not been systematically examined in men. To identify age-related alterations in vitamin D and PTH physiology and to assess their impact on skeletal health, we studied 62 normal men, aged 30-92 yr. The men were in excellent health, and none had any evidence of metabolic bone disease and/or known risk factors for osteopenia. Serum 25-hydroxyvitamin D (25OHD) concentrations declined steadily with advancing age (r = -0.47; P less than 0.001), and there was a corresponding decline in serum 24,25-dihydroxyvitamin D [24,25-(OH)2D] levels (r = -0.41; P less than 0.001). Serum 1,25-(OH)2D concentrations, however, did not vary over this age range (r = -0.07; P = NS). Plasma PTH levels increased with aging (r = -0.24; P less than 0.001), and there was a concomitant increase in urinary cAMP excretion (r = 0.38; P less than 0.001). Renal function (creatinine clearance) clearly declined with increasing age (r = -0.71; P less than 0.001). In conjunction with these changes in calcium metabolism, radial and vertebral bone mineral content declined. Whereas the fall in radial bone mineral content (single photon absorptiometry) at both proximal and distal sites was slight, there was a marked decrease in vertebral bone mineral content, as measured by quantitative computed tomography (r = -0.72; P less than 0.0001). The fall in vertebral bone mineral content correlated well with the declines in serum 25OHD and 24,25-(OH)2D concentrations (r = 0.47; P less than 0.001 and r = 0.51; P less than 0.001, respectively) and with the decline in renal function (r = 0.46; P less than 0.001). Multiple regression analysis revealed that the effects of aging on bone mineral content could be accounted for in large part by concomitant changes in mineral metabolism. Both the decline in renal function and the fall in serum 24,25-(OH)2D levels were closely associated with the fall in bone mineral content. These results indicate that a decline in renal function and alterations in vitamin D metabolism occur with aging in normal men. These changes contribute to, if not cause, the associated decline in skeletal mineral content in aging men.

Adult↗