The effect of teriparatide compared with risedronate on reduction of back pain in postmenopausal women with osteoporotic vertebral fractures.

UNLABELLED: The effect of teriparatide and risedronate on back pain was tested, and there was no difference in the proportion of patients experiencing a reduction in back pain between groups after 6 or 18 months. Patients receiving teriparatide had greater increases in bone mineral density and had fewer vertebral fractures. INTRODUCTION: This study aimed to understand the effect of teriparatide in reducing back pain in patients with prevalent back pain and vertebral fracture compared to risedronate. METHODS: In an 18-month randomized, double-blind, double-dummy trial, we investigated the effects of teriparatide (20 µg/day) vs. risedronate (35 mg/week) in postmenopausal women with back pain likely due to vertebral fracture. The primary objective was to compare the proportion of subjects reporting ≥30% reduction in worst back pain severity from baseline to 6 months as assessed by a numeric rating scale in each treatment group. Pre-specified secondary and exploratory outcomes included assessments of average and worst back pain at additional time points, disability and quality of life, bone mineral density, incidence of fractures, and safety. RESULTS: At 6 months, 59% of teriparatide and 57% of risedronate patients reported ≥30% reduction in worst back pain and there were no differences between groups in the proportion of patients experiencing reduction in worst or average back pain at any time point, disability, or quality of life. There was a greater increase from baseline in bone mineral density at the lumbar spine (p = 0.001) and femoral neck (p = 0.02) with teriparatide compared to risedronate and a lower incidence of vertebral fractures at 18 months (4% teriparatide and 9% risedronate; p = 0.01). Vertebral fractures were less severe (p = 0.04) in the teriparatide group. There was no difference in the overall incidence of adverse events. CONCLUSIONS: Although there were no differences in back pain-related endpoints, patients receiving teriparatide had greater skeletal benefit than those receiving risedronate.

Reduced incidence and severity of experimental autoimmune arthritis in mice expressing catalytically inactive A disintegrin and metalloproteinase 8 (ADAM8).

A disintegrin and metalloproteinase 8 (ADAM8), a catalytically active member of the ADAMs family of enzymes, is expressed primarily on immune cells and thus probably involved in inflammatory responses. ADAM8 is also produced by chondrocytes, and recombinant ADAM8 can induce cartilage catabolism. We therefore decided to test the role of ADAM8 in autoimmune inflammatory arthritis using transgenic mice expressing catalytically inactive ADAM8. Transgenic DBA/1J mice expressing an inactivating point mutation in the ADAM8 gene to change Glu330 to Gln330 (ADAM8(EQ)) were generated to evaluate the proteolytic function of ADAM8 in an lipopolysaccharide-synchronized collagen-induced arthritis (LPS-CIA) model of autoimmune arthritis. The systemic inflammatory reaction to LPS was also evaluated in these mice. Expression profiling of paw joints from wild-type mice revealed that ADAM8 mRNA levels increased at the onset of clinical arthritis and correlated well with cellular macrophage markers. When subjected to LPS-CIA, ADAM8(EQ) mice demonstrated decreased incidence and severity of clinical arthritis compared to wild-type mice. Histological examination of paw joints from ADAM8(EQ) mice confirmed marked attenuation of synovial inflammation, cartilage degradation and bone resorption when compared to wild-type mice. However, transgenic mice and wild-type mice responded similarly to LPS-induced systemic inflammation with regard to mortality, organ weights, neutrophil sequestration and serum cytokine/chemokine production. We conclude that ADAM8 proteolytic activity plays a key role in the development of experimental arthritis and may thus be an attractive target for the treatment of arthritic disorders while minimizing risk of immunocompromise.

Severity of prevalent vertebral fractures and the risk of subsequent vertebral and nonvertebral fractures: results from the MORE trial.

Prevalent vertebral fractures and baseline bone mineral density (BMD) predict subsequent fracture risk. The objective of this analysis is to examine whether baseline vertebral fracture severity can predict new vertebral and nonvertebral fracture risk. In the randomized, double-blind 3-year Multiple Outcomes of Raloxifene Evaluation (MORE) trial, 7705 postmenopausal women with osteoporosis (low BMD or prevalent vertebral fractures) were randomly assigned to placebo, raloxifene 60 mg/day, or raloxifene 120 mg/day. Post hoc analyses studied the association between baseline fracture severity and new fracture risk in the placebo group and the effects of placebo, raloxifene 60 mg/day, and raloxifene 120 mg/day on new fracture risk in women with the most severe prevalent vertebral fractures (n = 614). Vertebral fracture severity was visually assessed using semiquantitative analysis of radiographs and categorized by estimated decreases in vertebral heights. Reported new nonvertebral fractures were radiographically confirmed. Baseline vertebral fracture severity predicted vertebral and nonvertebral fracture risk at 3 years. In women without prevalent vertebral fractures, 4.3 and 5.5% had new vertebral and nonvertebral fractures, respectively. In women with mild, moderate, and severe prevalent vertebral fractures, 10.5, 23.6, and 38.1% respectively had new vertebral fractures, whereas 7.2, 7.7, and 13.8% respectively experienced new nonvertebral fractures. Number of prevalent vertebral fractures and baseline BMD also predicted vertebral fracture risk, but the severity of prevalent vertebral fractures was the only predictor of nonvertebral fracture risk and remained a significant predictor after adjustment for baseline characteristics, including baseline BMD. In patients with severe baseline vertebral fractures, raloxifene 60 mg/day decreased the risks of new vertebral [RR 0.74 (95% Cl 0.54, 0.99); P = 0.048] and nonvertebral (clavicle, humerus, wrist, pelvis, hip, and leg) fractures [RH 0.53 (95% CI 0.29, 0.99); P = 0.046] at 3 years. To prevent one new fracture at 3 years in women with severe baseline vertebral fractures with raloxifene 60 mg/day, the number needed to treat (NNT) was 10 for vertebral and 18 for nonvertebral fractures. Similar results were observed in women receiving raloxifene 120 mg/day. In summary, baseline vertebral fracture severity was the best independent predictor for new vertebral and nonvertebral fracture risk. Raloxifene decreased new vertebral and nonvertebral fracture risk in the subgroup of women with severe vertebral fractures at baseline. These fractures may reflect architectural deterioration, independent of BMD, leading to increased skeletal fragility.

Inducible, brain region-specific expression of a dominant negative mutant of c-Jun in transgenic mice decreases sensitivity to cocaine.

Administration of cocaine induces the Fos family of transcription factors in the striatum, including the nucleus accumbens (NAc), a brain region important for the rewarding effects of addictive drugs. Several Fos proteins are induced acutely by cocaine, with stable isoforms of DeltaFosB predominating after chronic drug administration. However, it has been difficult to study the functional consequences of these Fos responses in vivo. Fos proteins heterodimerize with members of the Jun family to form active AP-1 transcription factor complexes. In the present study, we took advantage of this property and generated transgenic mice, using the tetracycline gene regulation system, that support the inducible, brain region-specific expression of a dominant negative mutant form of c-Jun (Deltac-Jun), which can antagonize the actions of Fos proteins. Expression of Deltac-Jun in the striatum and certain other brain regions of adult mice decreases their development of cocaine-induced conditioned place preference, suggesting reduced sensitivity to the rewarding effects of cocaine. In contrast, Deltac-Jun expression had no effect on cocaine-induced locomotor activity or sensitization. However, expression of Deltac-Jun in adult mice blocked the ability of chronic cocaine administration to induce three known targets for AP-1 in the NAc: the AMPA glutamate receptor subunit GluR2, the cyclin-dependent protein kinase Cdk5, and the transcription factor nuclear factor-kappaB (NFkappaB), without affecting several other proteins examined for comparison. Taken together, these results provide further support for an important role of AP-1-mediated transcription in some of the behavioral and molecular mechanisms underlying cocaine addiction.

The prostaglandin E2 EP1 receptor mediates pain perception and regulates blood pressure.

The lipid mediator prostaglandin E2 (PGE2) has diverse biological activity in a variety of tissues. Four different receptor subtypes (EP1-4) mediate these wide-ranging effects. The EP-receptor subtypes differ in tissue distribution, ligand-binding affinity, and coupling to intracellular signaling pathways. To identify the physiological roles for one of these receptors, the EP1 receptor, we generated EP1-deficient (EP1-/-) mice using homologous recombination in embryonic stem cells derived from the DBA/1lacJ strain of mice. The EP1-/- mice are healthy and fertile, without any overt physical defects. However, their pain-sensitivity responses, tested in two acute prostaglandin-dependent models, were reduced by approximately 50%. This reduction in the perception of pain was virtually identical to that achieved through pharmacological inhibition of prostaglandin synthesis in wild-type mice using a cyclooxygenase inhibitor. In addition, systolic blood pressure is significantly reduced in EP1 receptor-deficient mice and accompanied by increased renin-angiotensin activity, especially in males, suggesting a role for this receptor in cardiovascular homeostasis. Thus, the EP1 receptor for PGE2 plays a direct role in mediating algesia and in regulation of blood pressure.

Development and validation of the mini-osteoporosis quality of life questionnaire (OQLQ) in osteoporotic women with back pain due to vertebral fractures. Osteoporosis Quality of Life Study Group.

The objective of the study was to evaluate a shortened osteoporosis quality of life questionnaire (OQLQ) in osteoporotic women with back pain due to vertebral fractures. From the longer 30-item OQLQ (four to nine items per domain) we created the mini-OQLQ by choosing the two items with the highest impact in each of five domains (symptoms, physical function, activities of daily living, emotional function, leisure). We administered the OQLQ, the Sickness Impact Profile, the SF-36 and the Brief Pain Index to patients at baseline, after 2 weeks and after 6 months. The intraclass correlations between baseline and the 2-week follow-up for the five mini-OQLQ domains ranged from 0.72 to 0.86. Cross-sectional correlations between the domains of the mini-OQLQ and other health instruments were moderate to large (0.35-0.80) and greater than predicted. The mini-OQLQ items showed moderate to large correlations with items omitted from the shortened questionnaire (0. 44-0.88). Correlations between the OQLQ domains and the other three instruments were greater than those of the mini-OQLQ, and partial correlations between OQLQ items omitted from the mini-OQLQ and the other three instruments after considering mini-OQLQ items were substantial (0.19-0.71) and statistically significant. Sample sizes of less than 200 per group should be required to detect minimally important differences in parallel-group clinical trials. Longitudinal correlations between the mini-OQLQ and the other measures were often significant but generally lower than predicted (0.10-0.49). The partial correlations revealed that the omitted items explained a significant portion of the longitudinal variance in each domain. We conclude that in a selected group of patients with back pain caused by vertebral fractures, the mini-OQLQ demonstrated good discriminative and adequate evaluative properties. The mini-questionnaire should be useful in clinical settings.

Identification of specific EP receptors responsible for the hemodynamic effects of PGE2.

To identify the E-prostanoid (EP) receptors that mediate the hemodynamic actions of PGE2, we studied acute vascular responses to infusions of PGE2 using lines of mice in which each of four EP receptors (EP1 through EP4) have been disrupted by gene targeting. In mixed groups of males and females, vasodepressor responses after infusions of PGE2 were significantly diminished in the EP2 -/- and EP4 -/- lines but not in the EP1 -/- or EP3 -/- lines. Because the actions of other hormonal systems that regulate blood pressure differ between sexes, we compared the roles of individual EP receptors in males and females. We found that the relative contribution of each EP-receptor subclass was strikingly different in males from that in females. In females, the EP2 and EP4 receptors, which signal by stimulating adenylate cyclase, mediate the major portion of the vasodepressor response to PGE2. In males, the EP2 receptor has a modest effect, but most of the vasodepressor effect is mediated by the phospholipase C-coupled EP1 receptor. Finally, in male mice, the EP3 receptor actively opposes the vasodepressor actions of PGE2. Thus the hemodynamic actions of PGE2 are mediated through complex interactions of several EP-receptor subtypes, and the role of individual EP receptors differs dramatically in males from that in females. These differences may contribute to sexual dimorphism of blood pressure regulation.

Autosomal dominant hypoparathyroidism associated with short stature and premature osteoarthritis.

Familial hypoparathyroidism is an unusual and genetically heterogeneous group of disorders that may be isolated or may be associated with congenital or acquired abnormalities in other organs or glands. We have evaluated a family with a novel syndrome of autosomal dominant hypoparathyroidism, short stature, and premature osteoarthritis. A 74-yr-old female (generation I) presented with hypoparathyroidism, a movement disorder secondary to ectopic calcification of the cerebellum and basal ganglia, and a history of knee and hip replacements for osteoarthritis. Two members of generation II and one member of generation III were also documented with hypoparathyroidism, short stature, and premature osteoarthritis evident as early as 11 yr. Because of the known association between autosomal dominant hypoparathyroidism and activating mutations of the calcium-sensing receptor (CaR) gene, further studies were performed. Sequencing of PCR-amplified genomic DNA revealed a leucine to valine substitution at position 616 in the first transmembrane domain of the CaR, which cosegregated with the disorder. However, this amino acid sequence change did not affect the total accumulation of inositol phosphates as a function of extracellular calcium concentrations in transfected HEK-293 cells. In conclusion, a sequence alteration in the coding region of the CaR gene was identified, but is not conclusively involved in the etiology of this novel syndrome. The cosegregation of hypoparathyroidism, short stature, and osteoarthritis in this kindred does suggest a genetic abnormality involving a common molecular mechanism in parathyroid, bone, and cartilage.

Calvarial doughnut lesions associated with high-turnover osteoporosis presenting in childhood.

Osteogenesis imperfecta and juvenile osteoporosis are two well-described syndromes of osteoporosis presenting in childhood. There are also several references in the radiology literature to calvarial doughnut lesions (CDLs), areas of radiolucency surrounded by a dense and well-defined area of sclerotic bone, either as an incidental finding or associated with childhood fracture. We have characterized the metabolic abnormalities in a 13-yr-old boy with CDLs and multiple fractures and followed him during his progression through puberty. The patient's paternal grandmother; father; and paternal aunt, uncle, and first cousin were similarly affected, and a mandibular lesion in the uncle was pathologically described as fibrous dysplasia. The subject's physical examination was significant for bony protuberances of the skull and normal hearing, sclearal hue, dentition, and joint flexibility. Radiographs revealed calvarial CDLs and osteopenia which was confirmed by bone mineral density (BMD) testing. Biochemical markers of bone formation and resorption were elevated compared to normal adult and a transiliac crest bone biopsy confirmed high-turnover osteoporosis. Over 6 yr, with no specific therapy, BMD gradually normalized, but the CDLs increased in size, bone turnover remained elevated by biochemical markers, and he continued to fracture. The subject's affected father and maternal grandmother had normal BMD and no history of adult fracture. CDLs with high-turnover osteoporosis should be considered in the differential diagnosis of pediatric osteoporosis. During puberty the BMD normalizes but the high-turnover state persists, and the propensity to fracture eventually decreases in older affected adults. The CDLs may be a variant of fibrous dysplasia, and further study is necessary in order to elucidate the stimulus for increased bone turnover and the familial nature of this syndrome.

Effects of human lymphocyte-conditioned medium on MG-63 human osteosarcoma cell function.

Lymphocytes are implicated in the pathogenesis of bone disease in chronic inflammation, osteoporosis, transplantation and osteopetrosis. The effects of lymphocytes and lymphocyte-conditioned medium on bone-resorbing activity and osteoclast function have been well studied, but there are few studies of the effects of LCM on bone formation and osteoblast function. The effects of LCM on the function of the MG-63 human osteosarcoma cell line were studied, which, when stimulated with 1,25-(OH)2D3, demonstrates many of the properties of the mature human osteoblast. Lymphocytes contain oestrogen receptors and the model was also used to test the hypothesis that the effects of oestrogen on bone cells may be mediated indirectly via lymphokines. Lymphokines were measured by ELISA in human lymphocyte conditioned medium (LCM) collected following incubation of mixed lymphocytes with or without stimulation for 72 h. Unstimulated LCM increased proliferation of MG-63 cells and this increase was not affected by neutralization of interleukin 1 (IL-1), IL-3, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), tumour necrosis factor (TNF), lymphotoxin alpha, or interferon gamma (IFN-gamma). Phytohaemagglutinin-stimulated LCM decreased proliferation of MG-63 cells, as well as induced expression of IL-6 mRNA, increased alkaline phosphatase production, and inhibited osteocalcin production. The decrease in proliferation was abolished by neutralization of IFN-gamma but was unaffected by neutralization of IL-1, IL-2, IL-3, IL-4, IL-6, GM-CSF, TNF, or lymphotoxin alpha. Neutralization of IFN-gamma in stimulated LCM also partially inhibited the increase in alkaline phosphatase production but had no effects on the decrease in osteocalcin production. Although oestrogen inhibited lymphocyte proliferation, the effects of LCM collected from lymphocytes in the presence of oestrogen on MG-63 cell proliferation and function was no different than the effects of LCM collected in the absence of oestrogen. LCM has multiple effects on MG-63 cell function and gene expression. Lymphocyte stimulation during the preparation of LCM further modulates these effects. Although partially mediated by IFN-gamma, the effects of LCM on these cells cannot be completely explained by individual component lymphokines. This may have implications for understanding the pathophysiology of bone loss in inflammatory disorders as well as possible feedback loops of locally generated cytokines in bone.

Clinical reporting to primary care physicians leads to increased use and understanding of bone densitometry and affects the management of osteoporosis. A randomized trial.

BACKGROUND: A major barrier to wider use of bone densitometry has been a lack of reports that are comprehensible to primary care physicians. OBJECTIVE: To compare the effect of short technical reports and longer clinical reports on use, understanding, and acceptance of bone densitometry by primary care physicians and on management of osteoporosis. DESIGN: Randomized trial. SETTING: Osteoporosis center of a community teaching hospital. SUBJECTS: 57 primary care physicians ordering bone mineral density tests with dual x-ray absorptiometry. INTERVENTION: Physicians were randomly assigned to receive short technical reports or long clinical reports written by endocrinologists with access to clinical information. MEASUREMENTS: Physicians were interviewed by telephone after receiving at least two reports. RESULTS: Before being interviewed, physicians receiving short reports ordered a mean +/- SD of 0.72 +/- 0.71 tests per month; those receiving long reports ordered 1.30 +/- 1.21 tests per month (P = 0.002). At the first interview, 30% of physicians receiving short reports and 86% of those receiving long reports understood the bone mineral density definition of osteoporosis (P < 0.001). Receiving long reports led to more modifications in the pharmacologic treatment of osteoporosis by gynecologists (19% of patients whose reports were short and 61% of patients whose reports were long; P = 0.021) and less confusion about reports by all physicians (36% of physicians receiving short reports and 1% of those receiving long reports; P = 0.003). CONCLUSIONS: Clinical reporting of bone densitometry to primary care physicians increased use and understanding of bone densitometry, changed management of osteoporosis, and was well accepted. It may help achieve appropriate use of bone densitometry and may allow convenient dissemination of information on osteoporosis.

Adolescent pregnancy and sexual risk-taking among sexually abused girls.

Data on 3,128 girls in grades eight, 10 and 12 who participated in the 1992 Washington State Survey of Adolescent Health Behaviors were used to analyze the association of a self-reported history of sexual abuse with teenage pregnancy and with sexual behavior that increases the risk of adolescent pregnancy. In analyses adjusting for grade level, respondents who had been sexually abused were 3.1 times as likely as those who had not been abused to say they had ever been pregnant; in multivariate analyses, respondents who had experienced abuse were 2.3 times as likely as others to have had intercourse but were not more likely than other sexually active respondents to have been pregnant. However, those with a history of sexual abuse were more likely to report having had intercourse by age 15 (odds ratio, 2.1), not using birth control at last intercourse (2.0) and having had more than one sexual partner (1.4). Thus, an association between sexual abuse and teenage pregnancy appears to be the result of high-risk behavior exhibited by adolescent girls who have been abused.

PIP: The association between a self-reported history of child sexual abuse and adolescent pregnancy was investigated in the 1992 Washington State (US) Survey of Adolescent Health Behaviors. Enrolled in the study were 3128 girls from 70 school districts in grades 8, 10, and 12. In these 3 grades, the prevalence of sexual abuse was 18%, 24%, and 28%, respectively. Sexual abuse was reported by 48% of students who had been pregnant at least once and 21% of those who had never been pregnant. After adjustment for grade level, girls who had been sexually abused were 3.1 times as likely to have ever been pregnant than those without such a history. In multivariate analysis controlled for other risk factors, sexually abused girls were 2.3 times more likely than others to have had sexual intercourse, but were not more likely than other sexually active girls to have been pregnant. However, those with a history of sexual abuse were more likely to have had intercourse by age 15 years (odds ratio (OR), 2.1), not to have used birth control at last intercourse (OR, 2.0), and to have had more than 1 sexual partner (OR, 1.4). These findings suggest that the association between sexual abuse and adolescent pregnancy results from the high-risk sexual behaviors of girls with an abuse history. Although the private nature of child sexual abuse impedes efforts at primary prevention, school counselors are urged to discuss child sexual abuse openly and target self-reported victims for pregnancy prevention.

Increments in bone mineral density of the lumbar spine and hip and suppression of bone turnover are maintained after discontinuation of alendronate in postmenopausal women.

PURPOSE: Previously we have reported a significant increase in bone mineral density (BMD) of the spine and the hip and reductions in biochemical indices of bone turnover in postmenopausal women with osteoporosis treated with alendronate at various doses over 1 to 2 years. We have followed BMD and biochemical parameters in these patients for 1 or 2 years after discontinuation of alendronate to determine resolution of alendronate effects. PATIENTS AND METHODS: Participants received daily oral doses of placebo, 5 or 10 mg of alendronate for 2 years, or 20 or 40 mg of alendronate for 1 year followed by 1 year of placebo. No treatment was given in the third year of study. RESULTS: Lumbar spine BMD changes in the 5- and 10-mg groups (-1.4 and -0.4%) were similar to those in the placebo group (-1.2%) 1 year after discontinuation of drug and lumbar spine BMD changes in the 20- and 40-mg groups (-1.2% and 0.8%) were similar to those in the placebo group (-0.9%) 2 years after discontinuation of drug. BMD of the total hip followed the same pattern of resolution. The difference in BMD between alendronate and placebo groups at the end of alendronate treatment was maintained up to 2 years. Residual reductions in the bone resorption markers urinary deoxypyridinoline (D-Pyr) and collagen type 1 cross-linked N telopeptides and the bone formation markers serum bone-specific alkaline phosphatase and osteocalcin remained for 1 year after discontinuation of 5 and 10 mg of alendronate and for 2 years after discontinuation of 20 and 40 mg of alendronate, other than return of D-Pyr to baseline 1 year after cessation of treatment with the 5- and 10-mg doses. CONCLUSIONS: A residual decrease in bone turnover may be found up to 2 years after discontinuation of alendronate. Accelerated bone loss is not observed when treatment is discontinued. However, continuous therapy with alendronate is required to achieve a continuous gain in BMD.

Collagen-induced arthritis is reduced in 5-lipoxygenase-activating protein-deficient mice.

Collagen-induced arthritis in the DBA/1 mouse is an experimental model of human rheumatoid arthritis. To examine the role of leukotrienes in the pathogenesis of this disease, we have developed embryonic stem (ES) cells from this mouse strain. Here, we report that DBA/1 mice made deficient in 5-lipoxygenase-activating protein (FLAP) by gene targeting in ES cells develop and grow normally. Zymosan-stimulated leukotriene production in the peritoneal cavity of these mice is undetectable, whereas they produce substantial amounts of prostaglandins. The inflammatory response to zymosan is reduced in FLAP-deficient mice. The severity of collagen-induced arthritis in the FLAP-deficient mice was substantially reduced when compared with wild-type or heterozygous animals. This was not due to an immunosuppressive effect, because anti-collagen antibody levels were similar in wild-type and FLAP-deficient mice. These data demonstrate that leukotrienes play an essential role in both the acute and chronic inflammatory response in mice.

A kindred with a variant of multiple endocrine neoplasia type 1 demonstrating frequent expression of pituitary tumors but not linked to the multiple endocrine neoplasia type 1 locus at chromosome region 11q13.

Acromegaly is uncommon in kindreds with multiple endocrine neoplasia type 1 (MEN1), whereas primary hyperparathyroidism (PHP) has the highest penetrance of any endocrinopathy. We report an unusual MEN1 kindred with frequent expression of pituitary tumors and a low penetrance of PHP. Four members were found to have disease: PHP in generation I, acromegaly (2 cases) in generation II, and hyperprolactinemia associated with a pituitary tumor in generation III. There was no evidence for PHP in 1 patient with acromegaly (age 60 yr), the patient with hyperprolactinemia and the pituitary tumor (age 22 yr), and 1 asymptomatic obligate carrier (age 50 yr). Screening of 26 members revealed the possible diagnosis of PHP in 1 family member in generation II and possible early acromegaly in 2 members of generation III with elevated serum concentrations of insulin-like growth factor I and insulin-like growth factor-binding protein-3 but normal patterns of pulsatile GH release. Although the predisposing genetic defect in typical MEN1 families has previously been mapped to chromosome location 11q13 without evidence of heterogeneity among the 87 families analyzed, linkage of disease in this family to the MEN1 region is unlikely based on haplotype analysis. Localization of the gene(s) responsible for disease in such atypical families may aid in the understanding of the pathogenesis of MEN1. In addition, further study of the earliest changes in patterns of pulsatile GH release in familial acromegaly may allow more insight into the pathogenesis and natural history of this disease.

A new embryonic stem cell line from DBA/1lacJ mice allows genetic modification in a murine model of human inflammation.

The development of embryonic stem (ES) cells and their capacity to generate mice with mutations at specific loci has provided a powerful resource for functional analysis of genes in pathological processes. However, the ability to combine this technology with the large number of existing murine models of human genetic disease has been complicated by the inability to routinely generate ES cell lines from strains other than 129. Here, we report the production of a novel ES cell line derived from an inbred mouse, DBA/1lacJ. This new ES cell line undergoes homologous recombination and efficient colonization of the germline of male chimeric offspring with ES cell microinjection into C57B1/6 embryos. The DBA/1lacJ mouse is a murine model of human inflammation, therefore genetic modifications in the DBA ES cells will allow evaluation of the target gene's role in the inflammatory process.

Alendronate treatment of the postmenopausal osteoporotic woman: effect of multiple dosages on bone mass and bone remodeling.

BACKGROUND: The effects of the aminobisphosphonate alendronate sodium on bone mass and markers of bone remodeling were investigated. PATIENTS AND METHODS: In a multicenter, randomized, double-blind, placebo-controlled, 2-year study, 188 postmenopausal women, aged 42 to 75 years, with low bone mineral density (BMD) of the lumbar spine were randomly assigned to 1 of 6 daily treatment groups: placebo for 2 years, alendronate 5 or 10 mg for 2 years, alendronate 20 or 40 mg for 1 year followed by placebo for 1 year, or alendronate 40 mg for 3 months followed by 2.5 mg for 21 months. All subjects were given 500 mg/d of elemental calcium as calcium carbonate. RESULTS: At each dose, alendronate produced significant reductions in markers of bone resorption and formation, and significantly increased bone mass at the lumbar spine, hip, and total body, as compared with decreases (significant at lumbar spine) in subjects receiving placebo. In the 10-mg group, mean urinary deoxypyridinoline/creatinine had declined by 47% at 3 months, and mean serum osteocalcin by 53% at 6 months. Mean changes in BMD over 24 months with 10 mg alendronate were +7.21% +/- 0.49% for the lumbar spine, +5.27% +/- 0.70% for total hip, and +2.53% +/- 0.68% for total body (each P < 0.01) compared to changes of -1.35% +/- 0.61%, -1.20% +/- 0.64% and -0.31% +/- 0.44% at these sites, respectively, with placebo treatment. Progressive increases in BMD of both lumbar spine and total hip were observed in the second year of treatment with 10 mg alendronate (both P < 0.05). CONCLUSION: Alendronate, a potent inhibitor of bone resorption, reduces markers of bone remodeling and significantly increases BMD at the lumbar spine, hip, and total body, and is well tolerated at therapeutic doses (5 or 10 mg daily) in the treatment of osteoporosis in postmenopausal women.

Gsh-1: a novel murine homeobox gene expressed in the central nervous system.

We report the characterization of Gsh-1, a novel murine homeobox gene. Northern blot analysis revealed a transcript of approximately 2 kb in size present at embryonic days 10.5, 11.5, and 12.5 of development. The cDNA sequence encoded a proline rich motif, a polyalanine tract, and a homeodomain with strong homology to those encoded by the clustered Hox genes. The Gsh-1 expression pattern was determined for days E8.5 to E13.5 by whole mount and serial section in situ hybridizations. Gsh-1 transcription was restricted to the central nervous system. Expression is present in the neural tube and hindbrain as two continuous, bilaterally symmetrical stripes within neural epithelial tissue. In the mesencephalon, expression is seen as a band across the most anterior portion. There is also diencephalon expression in the anlagen of the thalamus and the hypothalamus as well as in the optic stalk, optic recess, and the ganglionic eminence. Moreover, through the use of fusion proteins containing the Gsh-1 homeodomain, we have determined the consensus DNA binding site of the Gsh-1 homeoprotein to be GCT/CA/CATTAG/A.

Glycemic improvement in diabetic db/db mice by overexpression of the human insulin-regulatable glucose transporter (GLUT4).

The effects of increased GLUT4 (insulin-regulatable muscle/fat glucose transporter) expression on glucose homeostasis in a genetic model of non-insulin-dependent diabetes mellitus were determined by expressing a human GLUT4 transgene (hGLUT4) in diabetic C57BL/KsJ-db/db mice. A genomic hGLUT4 construct was microinjected directly into pronuclear murine embryos of db/+ matings to maintain the inbred background. Four lines of hGLUT4 transgenic mice were bred to homozygosity at the db locus and all showed a marked reduction of both fasted and fed plasma glucose levels (to approximately 50 and 360 mg/dl, respectively) compared with age-matched nontransgenic db/db mice (approximately 215 and 550 mg/dl, respectively), as well as an enhanced disposal of an oral glucose challenge. In situ immunocytochemical localization of GLUT4 protein in muscle from hGLUT4 db/db mice showed elevated plasma membrane-associated GLUT4 protein in the basal state, which markedly increased after an insulin/glucose injection. In contrast, nontransgenic db/db mice had low levels of plasma membrane-associated GLUT4 protein in the basal state with a relatively small increase after an insulin/glucose challenge. Since the intracellular GLUT4 levels in db/db mice were similar to nontransgenic db/+ mice, the glucose transport defect in db/db mice is at the level of glucose transporter translocation. Together, these data demonstrate that GLUT4 upregulation overcomes the glucose transporter translocation defect and alleviates insulin resistance in genetically diabetic mice, thus resulting in markedly improved glycemic control.

Tamoxifen and estrogen lower circulating lipoprotein(a) concentrations in healthy postmenopausal women.

Data in the literature suggest that circulating levels of lipoprotein(a) [Lp(a)] and insulinlike growth factor I (IGF-I) respond similarly to therapy with growth hormone, estrogen, or tamoxifen. To more clearly document these relations, we designed a randomized, double-blind, placebo-controlled study of the effects of tamoxifen and continuous estrogen on circulating levels of Lp(a), IGF-I, and IGF binding protein 3 (IGFBP-3) in healthy postmenopausal women. Both estrogen and tamoxifen decreased serum levels of IGF-I to 30% below baseline during the 3 months of treatment, while IGFBP-3 levels were unchanged. Plasma Lp(a) levels decreased to 24% below baseline after 1 month of treatment with either estrogen or tamoxifen (P < .05 for estrogen only); after 3 months Lp(a) decreased to 34% below baseline with tamoxifen therapy (P < .05) but returned to only 16% below baseline with estrogen. The correlation between Lp(a) and IGF-I was highly significant (P < .0001). We conclude that (1) tamoxifen lowers plasma Lp(a) levels in healthy postmenopausal women, (2) the suppressive effects of tamoxifen and estrogen on circulating Lp(a) concentration diverge after the first month of therapy, and (3) circulating levels of Lp(a) and IGF-I are strongly correlated with each other, an indication that they may share regulatory influences.