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J R Buchanan

Publications and source records attributed to J R Buchanan.

At least 37 records · Page 2Linked to original sources
PubMed1988

Effect of excess endogenous androgens on bone density in young women.

To determine whether endogenous androgens influence bone density in young women, we studied 27 normal women and 19 women with androgen excess, as defined by increased serum bioavailable testosterone (bio T) concentrations. The women ranged from 21-48 yr of age. The 2 groups were comparable with respect to age, anthropomorphic measures, nutrition, gynecological history, and serum cortisol and estradiol levels. Trabecular (lumbar) and cortical (radial) bone density were quantitated by computerized tomography and single photon absorptiometry, respectively. Serum obtained during the follicular phase of the cycle was assayed for bio T, total T, dehydroepiandrosterone sulfate, androstenedione (Adione), and 3 alpha-androstanediol glucuronide (3-Adiol-G). Trabecular bone density was significantly higher in the androgen excess group [172 +/- 7 (+/- SE) vs. 153 +/- 5 mg/mL; P = 0.03]; controlling for serum Adione (but not for serum bio T, total T, dehydroepiandrosterone sulfate, or 3 alpha-androstanediol glucuronide, or 3-Adiol-G) abolished this difference. Similarly, serum Adione correlated more strongly than the other androgens with trabecular bone density (r = 0.31; P = 0.03). Average cortical bone density was not higher in the androgen excess group (0.740 +/- 0.014 vs. 0.722 +/- 0.008 g/cm2; P = 0.27). Among the 27 normal women, cortical density was correlated to serum bio T (r = 0.47; P = 0.01) and total T (r = 0.53; P = 0.004), but not to the other androgens. We conclude that supraphysiological levels of endogenous androgens are associated with increased trabecular bone density in young women. Serum Adione appeared to be the best marker for the impact of androgen on trabecular density. Among normal women, cortical bone density was related to serum T.

Adult↗
PubMed1988

Should the patella be resurfaced in total knee arthroplasty? Efficacy of patellar resurfacing.

To assess the long-term efficacy of patellar resurfacing, 100 knees were evaluated in 84 patients. The operations were performed between 1978 and 1982. The follow-up period ranged from 60 to 103 months. The diagnosis was degenerative joint disease (DJD) in 83%, rheumatoid arthritis in 12%, and miscellaneous in 5% of the knees. The implant (47 knees) and nonimplant (53 knees) groups were comparable with respect to age, body size, and length of follow-up period. The analysis revealed equivocal results. Considering all diagnostic categories combined, rest pain was marginally better in the resurfaced group (p = 0.04), but this difference resulted from an unequal distribution of subjects between mild and zero pain categories. Pain with walking, maximum walking distance, ability to climb stairs and rise from a chair, active arc of motion, extensor lag, and quadriceps strength were similar in the two groups. When the DJD group was considered separately, no significant difference emerged. There was little evidence to support a recommendation for routine patellar resurfacing in total knee arthroplasty.

Activities of Daily Living↗
PubMed1988

Complex fracture-dislocation of the metacarpophalangeal joint. Case report.

A complex fracture-dislocation involving the fifth metacarpophalangeal (MCP) joint occurred in a 16-year-old boy approaching skeletal maturity. Roentgenographic examination demonstrated a widened MCP joint and a dorsally displaced Salter-Harris Type III fracture of the metacarpal head. Attempted manipulative closed reduction was unsuccessful. To achieve successful reduction and fixation it was necessary to make a dorsal approach, incise the interposed volar plate longitudinally, and lever it to the anatomic volar position. Successful fixation of the fracture would have been impossible through a volar approach. The Salter-Harris Type III fracture is a surgical problem.

Adult↗
PubMed1988

A comparison of the risk of vertebral fracture in menopausal osteopenia and other metabolic disturbances.

The risk of atraumatic compression fracture in postmenopausal women increases as vertebral trabecular bone density decreases. To determine whether the risk is similar for patients who have other metabolic disorders, we compared eight-nine patients who had various disturbances affecting bone and sixty-three postmenopausal women who had no evidence of underlying disease. Trabecular bone density was measured by quantitative computed tomography of the lumbar spine. The relationship between frequency of fracture and bone density was modeled mathematically with spline threshold, quadratic polynomial, and decaying exponential functions. Analysis of covariance showed that the diagnostic category did not influence the relationship between frequency of fracture and bone density in any of the three models. We concluded that the risk of atraumatic compression fracture, as assessed by measurement of vertebral trabecular bone density using quantitative computerized tomography, is independent of the underlying metabolic disturbance.

Adult↗
PubMed1988

Collegiate women athletes with irregular menses during adolescence have decreased bone density.

We studied six eumenorrheic and 13 oligomenorrheic collegiate women athletes who were matched in all respects other than menstrual histories. There was a significant (P less than .05) association between menstrual regularity and bone density. The severely oligomenorrheic subjects had modestly decreased plasma estrogen levels. These findings support the notion that plasma estrogen levels during adolescence play a significant role in the development of peak adult bone density in women.

Adolescent↗
PubMed1987

Adrenal androgens, sex-hormone binding globulin and bone density in osteoporotic menopausal women: is there a relationship?

The relationships among sex steroids, sex hormone binding globulin (SHBG) and vertebral bone density as measured by computerized tomography were studied in 18 post-menopausal women. A significant negative correlation was found between SHBG binding capacity (SHBG-BC) and bone density. Bone density and the adrenal androgen dehydroepiandrosterone sulfate (DHEAS) declined with age, and SHBG-BC was correlated significantly with DHEAS concentrations. The relationship between SHBG-BC and bone density may be affected by adrenal androgen output.

Adrenal Cortex Hormones↗
PubMed1987

Interrelationships of diet, athletic activity, menstrual status, and bone density in collegiate women.

We undertook a case-control study to examine the effect of nutritional factors on menstrual function and bone density in collegiate athletes. Three groups, matched with respect to age, height, and weight, were studied: eumenorrheic collegiate athletes, oligomenorrheic collegiate athletes, and eumenorrheic sedentary collegiate control subjects. Menarche was delayed in the eumenorrheic (13.1 y) and oligomenorrheic (14.3 y) athletic groups compared with the sedentary control subjects (12.2 y) (p less than 0.05). Average bone density tended (p = 0.10) to be lower in the oligomenorrheic athletes (158 mg/mL) compared with the eumenorrheic athletes (184 mg/mL) or sedentary control subjects (173 mg/mL). Dietary fiber intake was significantly elevated (p less than 0.05) in the oligomenorrheic athletes (5.74 g/d) compared with the eumenorrheic athletes (3.62 g/d) or sedentary control subjects (2.97 g/d). We conclude that increased dietary fiber intake is associated with menstrual dysfunction of these collegiate athletes. These factors may contribute to decreased bone density.

Adult↗
PubMed1987

Declining adrenal androgens: an association with bone loss in aging women.

Bone loss in aging women is a major contributing factor to the onset of osteoporosis. To determine whether a decline in adrenal androgen output might be important in the loss of bone with age, we studied a highly selected group of 14 women, average age 70, and measured adrenal androgens in relationship to trabecular bone density. Dehydroepiandrosterone sulfate (DHEAS) levels were used as a marker of adrenal sex steroid output while quantitative, computerized tomography was used to determine trabecular bone density. Our results showed that both bone density (r = -0.69, P less than 0.01) and DHEAS levels (r = -0.68, P less than 0.01) declined with age, and that DHEAS was positively correlated with bone density (r = 0.66, P = 0.01). These data emphasize the association of declining adrenal sex steroid production with declining bone density during the process of aging.

Adrenal Cortex↗
PubMed1987

Assessment of the risk of vertebral fracture in menopausal women.

The decision to institute prophylaxis in women with menopausal osteopenia is hampered by the absence of quantitative criteria for appraising the risk of fracture in the individual. We have developed standards for assessing the risk of fracture by relating the prevalence of atraumatic vertebral compression fractures to bone density in sixty-five menopausal women, forty-nine to ninety-two years old. To define the upper limit of the spectrum of bone density, we also studied thirty-one young women, seventeen to twenty-two years old. The density of trabecular bone in a vertebral body was determined by quantitative computed tomography and expressed in terms of milligrams per milliliter of dipotassium hydrogen phosphate. Twenty-five of the menopausal women exhibited at least one fracture (range, one to six fractures), and forty had no fracture. The bone density ranged from -9 to sixty-nine milligrams per milliliter in those with fractures and from twelve to 122 milligrams per milliliter in those without a fracture. The densities in the young women averaged 173 milligrams per milliliter and ranged from ninety-five to 248 milligrams per milliliter. The percentage of subjects with fractures increased as the bone density decreased. It was zero per cent in women with a density of seventy milligrams per milliliter or more, 38 per cent in women with a density between fifty and less than seventy milligrams per milliliter, 71 per cent in those with a density between thirty and less than fifty milligrams per milliliter, and 82 per cent in women with a density of less than thirty milligrams per milliliter.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

The effect of endogenous estrogen fluctuation on metabolism of 25-hydroxyvitamin D.

To test the hypothesis that estrogen modulates the metabolism of 25-hydroxyvitamin D (25(OH)D) to 1,25-dihydroxyvitamin D (1,25(OH)2D) and 24,25-dihydroxyvitamin D (24,25(OH)2D), we studied 20 normal premenopausal women at four consecutive weekly intervals during one menstrual cycle. Estrogen stimulation was semiquantitatively defined into baseline, low-grade, or medium-grade categories, based on endogenous estrone and estradiol concentrations. 1,25(OH)2D increased incrementally from baseline levels of 34 +/- 3(SE) pg/ml to 39 +/- 3 pg/ml (P = 0.2) with low-grade estrogen stimulation and to 43 +/- 3 pg/ml (P less than 0.05) with medium-grade estrogen stimulation, while 25(OH)D, 24,25(OH)2D, vitamin D binding protein, parathyroid hormone, calcium, and phosphate did not change. 24,25(OH)2D was correlated to 25(OH)D at baseline (r = 0.65, P less than 0.01) and with low-grade estrogen stimulation (r = 0.62, P less than 0.01), but not with medium-grade stimulation (r = 0.13); these relationships are consistent with the concepts that 25(OH)D is metabolized predominantly to 24,25(OH)2D at low estrogen levels, but not at higher estrogen levels. We conclude that endogenous estrogen elevation promotes formation of 1,25(OH)2D from 25(OH)D, and that it may reciprocally inhibit synthesis of 24,25(OH)2D.

24,25-Dihydroxyvitamin D 3↗
PubMed1986

Interaction between parathyroid hormone and endogenous estrogen in normal women.

It has been hypothesized that estrogens conserve bone substance by blocking the resorbing effect of parathyroid hormone (PTH). We evaluated this hypothesis by examining the relation of circulating PTH to endogenous estrogen fluctuation during four quarters of a single menstrual cycle in 20 normal women. The hypothesis predicts that PTH should vary directly with estrogen, since PTH should increase following estrogen elevation to satisfy physiologic demands for calcium. Contrary to the predicted direct variation, PTH remained constant throughout the menstrual cycle despite sharply fluctuating estrogen levels. Furthermore, PTH was negatively associated with estrone during the early follicular (r = -.65, P less than 0.005) and late follicular (r = -.84, P less than 0.0001) phases. We attempted to determine whether this unexpected relationship between estrone and PTH signified a direct physiologic link, by excluding factors which could have spuriously engendered the inverse correlation. Stepwise multiple regression and partial correlation showed that estrone contributed significantly to circulating PTH independent of the effects of dietary calcium, 25-hydroxyvitamin D, serum calcium, 1,25-dihydroxyvitamin D, phosphate, estradiol, progesterone, and body weight. Therefore, it is possible that the inverse correlation between estrone and PTH signified a direct physiologic link, as an artifactual cause for the relationship could not be identified. These data imply that estrone interacts with PTH, but not by blocking PTH-mediated bone resorption. We conclude that estrone is associated with reduced circulating PTH through an as yet undetermined mechanism.

Adult↗
PubMed1984

Distal ulnar growth arrest.

Four cases of arrest of distal ulnar physeal growth occurring in children ages 7 to 13 years had follow-up for 2 to 10 years. Each patient developed bowing of the radial diaphysis, ulnar translation of the distal radial epiphysis, and increased ulnar angulation of the distal radiocarpal joint surface. Growth discrepancies were documented in both the ulna (range 2.2 to 3.9 cm) and to a lesser extent the radius (range 0.2 to 1.6 cm) when compared to the opposite forearm in each patient. The progression of deformity appeared to be greatest during adolescence. Radial deviation and pronation were limited to varying degrees in each case. No patient had significant pain or functional impairment, but the cosmetic appearance was always displeasing. Indications for surgical treatment include increasing ulnar angulation of the distal radial articular surface, progressive loss of motion, and displeasing cosmetic appearance.

Adolescent↗
PubMed1984

Surgical treatment of plantar fasciitis.

Ten patients were operated on for plantar fasciitis (12 heels) by stripping the plantar fascia and superficial plantar muscles from the calcaneus. All patients were refractory to conservative treatment for an average of 12.4 months prior to operation and were followed up for a minimum of 24 months after operation. Complete symptomatic relief was obtained in all patients despite the presence of massive obesity in six. Hypoesthesia of the heel, which was present in five feet after operation, may have enhanced pain relief. Three patients who were receiving workmen's compensation returned to work within 16 weeks of surgery. One deep wound infection occurred and required surgical debridement before healing could occur. Surgical treatment is efficacious in selected cases of plantar fasciitis that are refractory to conservative measures.

Adult↗
PubMed1981

Hereditary multiple exostoses: report of a kindred.

In a large family with 37 members with multiple exostoses, only one person has developed sarcomatous degeneration of a lesion. Our review of published reports revealed great variation in the incidence of malignancy in multiple exostoses (10 to 25%). Most studies had sampling errors leading to the apparent overstatement of risk. In large pedigrees with essentially complete ascertainment of affected subjects, the risk of malignancy is nearer 3% or less. This lower risk for malignancy may be more appropriate in counselling affected subjects.

Adolescent↗
PubMed1981

Management strategy for prevention of avascular necrosis during treatment of congenital dislocation of the hip.

We retrospectively analyzed the cases of fifty children with unilateral congenital dislocation of the hip in an attempt to determine what factors in treatment were associated with the prevention of avascular necrosis of the femoral head. All children were less than thirty-six months old at the initiation of treatment, had no other anomalies, had their entire treatment rendered at the same institution, and were followed for at least one year after reduction. Avascular necrosis occurred in 36% of the patients; in all cases definite roentgenographic signs were apparent within twelve months of reduction. No patient whose hip had grown normally during the first twelve months after reduction later had avascular necrosis. The management strategy for congenital dislocation of the hip in the child who is less than thirty-six months old should include a minimum two-week period of traction until achievement of the +2 traction station and immobilization in the so-called human position following reduction. Skeletal traction, gradually increased over several weeks to an average of 39% of body weight, usually was required to attain the +2 station. Observation of these principles should decrease the incidence of avascular necrosis and increase the probability of obtaining a normal hip.

Adolescent↗
PubMed1980

Gas gangrene in a wound treated without skin closure: a case report.

Clostridial myonecrosis developed in a compound tibial fracture wound left open after extensive surgical debridement. The patient survived after having a below-knee amputation and postoperative erythromycin. Prophylactically administered cephalothin failed to prevent the clostridial infection.

Adult↗