The prevalence of radiographic vertebral fractures in Latin American countries: the Latin American Vertebral Osteoporosis Study (LAVOS).

UNLABELLED: In the first population-based study of vertebral fractures in Latin America, we found a 11.18 (95% CI 9.23-13.4) prevalence of radiographically ascertained vertebral fractures in a random sample of 1,922 women from cities within five different countries. These figures are similar to findings from studies in Beijing, China, some regions of Europe, and slightly lower than those found in the USA using the same standardized methodology. INTRODUCTION: We report the first study of radiographic vertebral fractures in Latin America. METHODS: An age-stratified random sample of 1,922 women aged 50 years and older from Argentina, Brazil, Colombia, Mexico, and Puerto Rico were included. In all cases a standardized questionnaire and lateral X-rays of the lumbar and thoracic spine were obtained after informed consent. RESULTS: A standardized prevalence of 11.18 (95% CI 9.23-13.4) was found. The prevalence was similar in all five countries, increasing from 6.9% (95% CI 4.6-9.1) in women aged 50-59 years to 27.8% (95% CI 23.1-32.4) in those 80 years and older (p for trend < 0.001). Among different risk factors, self-reported height loss OR = 1.63 (95% CI: 1.18-2.25), and previous history of fracture OR = 1.52 (95% CI: 1.14-2.03) were significantly (p < 0.003 and p < 0.04 respectably) associated with the presence of radiographic vertebral fractures in the multivariate analysis. In the bivariate analyses HRT was associated with a 35% lower risk OR = 0.65 (95% CI: 0.46-0.93) and physical activity with a 27% lower risk of having a vertebral fracture OR = 0.73 (95% CI: 0.55-0.98), but were not statistically significant in multivariate analyses CONCLUSION: We conclude that radiographically ascertained vertebral fractures are common in Latin America. Health authorities in the region should be aware and consider implementing measures to prevent vertebral fractures.

Assessment of the educational experience in the Neurosurgery Residency Program of the University of Puerto Rico Medical Sciences Campus

OBJECTIVE: In 2003, the American Council of Graduate Medical Education (ACGME) made significant changes in the medical postgraduate training policies, especially the 80 Duty Hours per Week regulation. The Neurological Surgery Department at Mayo Clinic performed a national survey regarding the perceptions of program directors and residents on how compliance with the ACGME requirements has changed neurosurgery training. Using a similar methodology, we analyzed the University of Puerto Rico's Medical Sciences Campus, Neurological Surgery Division's resident and faculty staff perceptions with regard the way its training is currently performed. METHODS: Anonymous questionnaires were distributed among the neurosurgery division's resident and faculty staff at the University of Puerto Rico Medical Sciences Campus. Performance on the American Neurological Surgery Board (ANSB) written examinations was obtained from residents' records. The quantity and types of surgeries performed by residents was retrieved from neurosurgery section computer files. The relevant data was entered into a database and descriptive analysis and frequency distributions were performed. RESULTS: Surveys showed some concerns from both residents and attending physicians on the topics of inpatient and outpatient facilities, research activities, duty hours and the number of residents currently in the program. An upward trend in the residents' ANSB written examination performance was observed over the years. The residents' yearly number and diversity of surgical procedures were adequate. CONCLUSIONS: Considering the results from the surveys, the performance of residents in the Board examination, and their surgical experience, it is concluded that the general perception of the educational experience in neurosurgery is satisfactory but improvements could be made.

Osteopenia in Puerto Ricans with Crohn's disease.

BACKGROUND: Osteopenia has been reported in association to Inflammatory Bowel Disease, and in particular Crohn's disease. The use of corticosteroids, resection of the ileum, malabsorption, poor calcium intake, and the effect of inflammatory cytokines have all been considered as contributing factors. As Crohn's disease is more prevalent in young people, when peak bone mass is achieved, the presence of osteopenia is especially significant. OBJECTIVES: The aim of this study was to evaluate the bone density of patients with Crohn's disease in the University of Puerto Rico IBD Clinic; to determine the prevalence of osteopenia in these patients and to correlate bone mineral density with risk factors for osteopenia. METHODS: Sixty-six patients, 30 males and 36 females were included. After informed consent, demographic, clinical and metabolic data was obtained. Serum albumin, calcium, inorganic phosphorus and alkaline phosphatase were measured. Body mass index (BMI) was calculated. Bone density was determined by DEXA of the lumbar spine and femur and expressed as the Z score (standard deviations from normal correlated with sex and age). Severe osteopenia was a Z score > or = -2 and osteopenia was Z < or = -1.99 or > or = 1.01. Results were expressed in means. Pearson correlation coefficient was used for quantitative variables and Pearson chi-square for categorical values. RESULTS: Osteopenia was present in the hip in 69% and in the lumbar spine in 68%. Most patients had received steroids; the difference between treated and not treated patients was not significant. Osteopenia did not correlate with ileal resection, gender, BMI, disease characteristics or biochemical parameters. CONCLUSIONS: Low bone density was frequent in patients with Crohn's disease, but no specific risk factors could be identified. Bone density should be determined in patients with Crohn's disease in order to institute appropriate therapeutic measures.

Chronic inhalation carcinogenicity study of commercial hexane solvent in F-344 rats and B6C3F1 mice.

The carcinogenic and chronic toxicity potential of commercial hexane solvent was evaluated in F-344 rats and B6C3F1 mice (50/sex/concentration/species) exposed by inhalation for 6 h/day, 5 days/week for 2 years. Target hexane vapor concentrations were 0, 900, 3000, and 9000 ppm. There were no significant differences in survivorship between control and hexane-exposed groups, and clinical observations were generally unremarkable. Small, but statistically significant decreases in body weight gain were seen in rats of both sexes in the mid- and high-exposure groups and in high-expsoure female mice. The only noteworthy histopathological finding in rats was epithelial cell hyperplasia in the nasoturbinates and larynx of exposed groups. This response was judged to be indicative of upper respiratory tract tissue irritation. No significant differences in tumor incidence between control and hexane-exposed rats were found. In mice, uterine tissue from the high-exposure females exhibited a significant decrease in the severity of cystic endometrial hyperplasia compared to controls. An increase in the combined incidence of hepatocellular adenomas and carcinomas was observed in high-exposure female mice. The incidence of liver tumors was not increased in the mid- or low-exposure female mice or in male mice exposed to hexane. An increased incidence of pituitary adenomas was observed in female, but not male mice. This finding was not believed to have been treatment-related because the incidence in the control group was unusually low, and the incidence in exposed groups was not dose-related and was within the historical control range. No other neoplastic changes judged to be treatment-related were observed in tissues from male or female mice. In conclusion, chronic exposure to commercial hexane solvent at concentrations up to 9000 ppm was not carcinogenic to F-344 rats or to male B6C3F1 mice, but did result in an increased incidence of liver tumors in female mice.

Clinical profile of 128 subjects operated for primary hyperparathyroidism.

From 1960 to 1990, one hundred twenty eight (128) subjects with primary hyperparathyroidism were operated in the University Hospital. The medical records were reviewed. Serum and urine chemistries were done by conventional methods, serum PTH was done by RIA's (N-, C-, and midregion) and intact by IRMA and 1,25 dihydroxycholecalciferol by a non equilibrium receptor assay from calf thymus and preceded by double Sep-Pak chromatography. The distal third of the radius (nondominant arm) was used to evaluate radial bone density (RBD), using single photon absorptiometry (Norland) and the lumbar bone density (LBD) was measured by dual energy X Ray absorptiometry (DEXA). The RBD was done in 41 females and 15 males and the LBD in 12 females and 4 males. The series comprised 95 females, age range from 15 to 79 years, and 33 males, age range from 14 to 69 years. Prominent clinical features included nephrolithiasis in 72 subjects (56%), osteitis fibrosa cystica in 2, isolated familial hyperparathyroidism in 4 subjects in one family, 7 subjects with MEN-1 in 3 families, and 4 subjects with MEN-2 in one family. Only 7 subjects were asymptomatic. Serum calcium was elevated in all, serum alkaline phosphatase was elevated in 24% and urinary hydroxiproline was increased in 48%. Serum phosphorus was low in 92%. PTH assay was either elevated or inappropriately normal for the serum calcium in all patients tested. Serum 1,25 D was elevated in 57%. The PTH level was positively correlated with the serum calcium (r = 0.70), but had no significant correlation with the serum phosphorus and the 1,25 D. The RBD expressed as the standard deviation from that of the mean for age and sex matched controls was > or = 2 SD below the mean in 39% of females and in 40% of males. In contrast to the RBD none of the subjects tested had a LBD > or = 2 SD below the age and sex adjusted mean. 103 subjects had adenomas, 20 primary hyperplasia, 2 carcinomas and in 3 surgical exploration was unsuccessful. As to the outcome of Surgery, 117 (93%) were cured. Thus, in this series, successful surgery for primary hyperparathyroidism is the rule. Primary hyperparathroidism is rarely asymptomatic and appendicular bone disease and nephrolithiasis are commonly seen.

Prevalence of osteopenia and osteoporosis in a normal female Puerto Rican population.

The World Health Organization criteria for the diagnosis of Osteopenia and Osteopoposis was applied to a control group of 33 females ages 50 to 59 years and 24 females ages 60 to 69 years. The general exclusion criteria for the selection of subjects included early menopause and diseases, use of drugs and toxic habits such as smoking and alcoholism, known to affect bone and mineral metabolism. Bone mineral densities were measured with a DEXA Hologic, model 1000. In the reference population mean peak bone mineral density expressed in g/cm2 was 1.051 (SD = 0.119) for the lumbar spine at age 30 to 39 years and for the femoral neck 0.861 (SD = 0.098) at age 20 to 29 years. Bone densities below 1 to 2.5 SD from mean peak bone mass ranged from 0.932 to 0.754 g/cm2 in the lumbar spine and 0.763 to 0.616 g/cm2 for the femoral neck. The mean age of the pooled group was 58.4 years. The prevalence of osteopenia in the pooled group was 42 % for the lumbar spine and 56% for the femoral neck and of osteoporosis, 12% for the lumbar spine and 8.7% for the femoral neck. A similar prevalence has been found by other investigators in hispanic populations. Such a high percentage of females with osteopenia implicates that bone densitometry must be done in the perimenopausal years and in young individuals at risk so as to proceed with early medical intervention to prevent osteoporosis.

The lumbar and femoral bone mineral densities in a normal female Puerto Rican population.

The aim of this study was to establish the reference values of the bone mineral density (BMD) of the lumbar spine and the proximal femur in a normal adult female Puerto Rican population. In the selection of the population, exclusion criteria included diseases, use of drugs and toxic habits (smoking and alcoholism) known to affect bone and mineral metabolism. The study population comprised 131 healthy females, ages 20 to 69 years. Spinal radiographs were taken of women age 60 or more to exclude spinal defects or artifacts. The bone mineral densities were measured using the dual energy X Ray absorptiometer (DEXA, Hologic model 1000). The peak BMD was found in the lumbar spine at the age 30 to 39 years and at the age 20 to 29 years in the femoral neck, trochanter and Ward's triangle. The decrease in BMD from peak values to those at age 60 to 69 years were 18% for the lumbar spine, 16.3% for the femoral neck, 30.1% for the Ward's triangle and 12.4% for the trochanter. The major fall in the BMD was related to the menopause and compares with that of other series. There was no statistical difference from Hologic reference values in a mixed population of the USA.

Unusual cases of hyperparathyroidism.

The history, physical and radiologic findings, treatment and pathology in five unusual cases of hyperparathyroidism is presented. The hyperparathyroidism was caused by a large (113 grams) mediastinal adenoma in the first patient, who is alive 25 years after surgery. A parathyroid carcinoma with compression of the esophagus was documented in the second patient. This patient is alive and normocalcemic 23 years after surgical treatment. A third patient with hyperplasia returned with hypercalcemia 20 years postsurgery requiring reoperation. A fourth patient with advanced bone findings was found to have a parathyroid adenoma. The fifth case is a patient with tertiary hyperparathyroidism secondary to hypophosphatemic rickets.

Increased erythrocyte calcium pump activity in a kindred with familial benign hypercalcaemia.

The hypothesis that a global defect in cellular calcium transport may be critical in the development of familial benign hypercalcaemia (FBH) was investigated. Nine hypercalcaemic patients from a kindred with FBH and nine normal subjects were evaluated. Our results indicate that calcium pump activity in the FBH kindred was significantly higher (28%, P < 0.005) when compared to normal subjects. These findings suggest that alterations in calcium pump activity in target tissues may play a role in the development of FBH.

Two-generation reproduction study on commercial hexane solvent.

The reproductive effects of inhalation exposure to commercial hexane vapors were evaluated in Sprague-Dawley rats. Males and females were exposed to commercial hexane vapor at target concentrations of 0, 900, 3000 or 9000 ppm for 6 h a day, 5 or 7 days a week, over two generations. In addition to pre-breed exposures of 10 weeks' duration, exposures continued through mating, gestation and lactation. At both the F0 breed to produce F1 litters and the F1 breed to produce F2 litters, reproductive parameters were unaffected by commercial hexane exposure. The mating, fertility and gestational indices, as well as litter size and postnatal survival, were not significantly different between exposure groups. However, reductions in body weight and body weight gain were observed in both F1 and F2 litters exposed to 9000 ppm. Effects on body weight were not observed in offspring exposed to the two lower concentrations of commercial hexane. Histopathological examination of selected tissues revealed hyaline droplet nephropathy in adult F0 and F1 males exposed to 9000 ppm. This finding was anticipated and is not believed to be relevant for the assessment of human health effects. No other treatment-related histopathological lesions were observed. Thus, exposure of rats to commercial hexane for two generations resulted in reduced body weight gains at 9000 ppm but no adverse effects on reproduction. These findings suggest that occupational exposure to commercial hexane vapors at currently recommended threshold limit value concentrations (i.e. TLV for n-hexane is 50 ppm and TLV for other hexane isomers is 500 ppm) should not pose a reproductive hazard.

Pheochromocytoma: a twenty year experience at the University Hospital.

During the past 20 years (1970-90), we had 24 patients with pheochromocytoma: 19 diagnosed clinically and 5 post-mortem. Their ages ranged from 17 to 74 (mean, 43.2 years). Males (n = 14) outnumbered females (n = 10), a 1.41:1 M:F ratio. A majority were symptomatic (95%), with a typical triad of headaches, palpitations and diaphoresis. Most frequent finding was hypertension (95%). It was sustained in 60% and paroxysmal in 35%. In 6 patients (25%) pheochromocytomas were bilateral, all familial. Fifteen were solitary adrenal tumors (63%); 3 (12.5%) were extra-adrenal: 2 intra-abdominal, and 1 cardiac paraganglioma of right atrium. Of 6 familial cases, 4 were associated to Von Hippel-Lindau (VHL) disease, while 2 were multiple endocrine neoplasia (MEN-II) patients. All familial cases were bilateral and in the adrenals. There were no malignancies. Among the 19 clinical cases pre-operative Dx was made by positive urine VMA or catecholamines urine levels: (95 and 100% sensitivity respectively). Preoperative visualization by CT or MRI was done in 62% of the most recent patients. In 5 earlier cases the diagnosis was made post mortem: 3 died of cerebral hemorrhage, 1 with a pons infarct and 1 with congestive heart failure (CHF). There were 2 post-operative deaths and another died 13 years later from thyroid medullary carcinoma. Of the 19 operated, 13 (68%) were cured. Thus pheochromocytomas retain considerable morbidity and some mortality. These rare tumors constitute a clinical diagnostic challenge yet a rewarding therapeutic experience for the alert physician.

Prevalence rates for diabetes mellitus in Puerto Rico.

The aim of this study was to analyze prevalence data for diabetes mellitus obtained from a household interview of a random sample of the general population by the Department of Health of the Commonwealth of Puerto Rico for the years 1975-1986. Details of the prevalence rate by sex and age were analyzed for the years 1981, 1984, 1985, and 1986 and for the urban and rural population in 1985. The mean prevalence rate of known cases of diabetes showed a tendency to increase from 3.1% in 1975 to 5.1% in 1986. Prevalence rates adjusted for age and sex showed an increase in the mean prevalence for 1986 compared with that of 1981. The prevalence rate was significantly higher for the rural population for the age-group 45-64 yr old and for the urban population for the age-group greater than or equal to 65 yr. The prevalence rate compares with that of Mexican Americans and Puerto Ricans in the New York City area. On the basis of the prevalence data, approximately 90% of the diabetic population is non-insulin dependent and 10% are insulin dependent. Major risk factors thought to explain the increased prevalence of non-insulin-dependent diabetes are increasing longevity of the Puerto Rican population, genetic predisposition, obesity, and changes in life-styles. In conclusion, Puerto Ricans, as other Hispanic Americans, have a higher prevalence of diabetes than the white American population.

Efficacy of 1, alpha 25-dihidroxyvitamin D (Calcitriol) in the treatment of psoriasis vulgaris: an open study.

Several reports have appeared in the literature suggesting that Vitamin D metabolites and analogues may be useful for the treatment of psoriasis. This is a report of an open study in which the efficacy of 1, Alpha-25-dihydroxyvitamin D (Calcitriol) is evaluated in cases of moderate to severe psoriasis. Study of ten cases showed moderate improvement in four when using calcitriol at a daily dose of 0.5 microgram for a period of three months. All Vitamin D metabolites were within normal limits during and after the trial. Further trials with calcitriol as an adjuvant therapy to topical steroids or photochemotherapy, as well as the development of topical Vitamin D analogues may be the future of this novel therapeutic alternative for psoriasis.

Premature thelarche in Puerto Rico. A search for environmental factors.

Pediatric endocrinologists in Puerto Rico reported a threefold increase in the number of patients with premature thelarche seen between 1978 and 1981. A matched-pairs case-control study was conducted to evaluate associations with potential environmental exposures to substances with estrogenic activity, as well as with familial factors. Analysis was performed on 120 pairs, the case subjects of which were selected from those diagnosed between 1978 and 1982. In subjects 2 years of age or older at the onset of thelarche, no significant associations were found. In subjects with onset before 2 years of age, significant positive associations were found with a maternal history of ovarian cysts, consumption of soy-based formula, and consumption of various meat products. A statistically significant negative association was found with consumption of corn products. These statistical associations are probably not sufficient to explain the reported increase because in over 50% of the case subjects there was no exposure to any of the risk factors for which statistical associations were found. Exposure to other substances with possible estrogenic effect, such as waste products from pharmaceutical factories and pesticides, was also excluded as a possible cause. These findings suggest that better diagnosis and reporting, or conceivably the presence of entirely new, unsuspected factors, could account for the reported increase.

The kinetics of D3-3H metabolism in tropical sprue.

The metabolism of vitamin D3-3H was studied in a small group of controls and subjects with tropical sprue after the oral or intravenous administration of 8 to 10 microCi of D3-3H. The biological half life of D3-3H upon the administration of the isotope by the intravenous route was normal in 2 controls, very low in a subject with tropical sprue who had steatorrhea, and decreased in a subject with tropical sprue who did not present steatorrhea. After the administration of the isotope by the oral route, the biological half life was 35 hours in the control and no radioactivity could be detected in the plasma of the subject with tropical sprue who had steatorrhea. Twenty four hours after the intravenous dose the percentage of radioactivity in the plasma as HCC-3H was two times higher in the tropical sprue subjects than in the controls. When the dose was given orally the net absorption was 50.5% in the subject with tropical sprue and steatorrhea and 86.8% in the subject with tropical sprue who was partially treated. These results showed rapid clearance of the D3-3H in the subject with tropical sprue and steatorrhea indicating depletion of vitamin D stores in the tissues and decrease in the net absorption of the dose when given orally. The presence of a higher percentage of the dose in the plasma as HCC-3H after the intravenous and oral administrations in the tropical sprue subjects when compared to controls indicates that the diseased state does not alter vitamin D3 metabolism.