Unbalanced diet to lower serum cholesterol level is a risk factor for postmenopausal osteoporosis and distal forearm fracture.

The purpose of this study was to assess whether dietary changes aimed at reducing serum cholesterol can increase the risk of osteoporosis (OP) and fracture. The study group consisted of 311 postmenopausal women with high serum cholesterol levels and following a diet low in dairy products (calcium intake estimated at less than 300 mg/day) for 27.3 +/- 29.1 months. This sample was compared with a case-control group of 622 healthy postmenopausal women paired for age and age at menopause and with a calcium intake estimated at more than 1 g/day. Bone mineral density was measured at the lumbar spine by dual-energy X-ray absorptiometry. Prevalence of OP was significantly higher in women with a low dairy calcium intake (42.1% vs 22.3%; p < 0.0001), as was the number of Colles' fractures occurring after menopause (4.5% vs 1.6%; p = 0.008). Multiple logistic regression analyses demonstrated that a diet low in dairy calcium was a risk factor for OP (OR = 2.52, 95% CI 1.84-3.45) and Colles' fracture (OR = 2.72, 95% CI 1.18-6.26). In the low dairy calcium group, diet duration significantly influenced the risk of OP (OR = 1.13, 95% CI 1.01-1.25 for 1 year of diet). No differences in further risk factors for coronary heart disease were found between the groups, but the proportion of women physically active was lower in the women with high serum cholesterol levels. A diet that severely limits calcium intake from dairy products in an attempt to correct raised serum cholesterol levels is a risk factor for postmenopausal OP and Colles' fracture. Dietary intervention methods to lower serum cholesterol in postmenopausal women should maintain an adequate calcium intake by providing calcium from low-fat dairy products or calcium supplements.

Characterization of human group C rotavirus in Argentina.

A survey was conducted for identification of human group C rotaviruses in stool specimens taken from children suffering diarrhea in suburban Buenos Aires regions. Among 90 true negative group A samples as defined by ELISA, RT-PCR and PAGE, five were positive by group C specific RT-PCR (VP7 and VP6 genes) and three of these samples exhibited the characteristic 4-3-2-2 dsRNA pattern of group C rotavirus. These results were further confirmed by electron microscopy and by ELISA for detection of group C VP6 specific antigens. Sequence analysis of the VP7 gene from one of these isolates revealed a 97.3-98.6% nucleotide identity and up to 99.1% protein homology with human group C rotavirus strains found scattered throughout the last ten years in other countries. Conversely, similar analysis performed with porcine strains showed a much lower homology degree both at the nucleotide (75.5% nucleotide identity) and amino acid level (85.5% protein homology). Detection of group C rotavirus in children with acute diarrhea in Argentina extends the identification range of this agent in the region and is consistent with previous reported data that demonstrate a global distribution of this virus.

Intravenous clodronate in the treatment of reflex sympathetic dystrophy syndrome. A randomized, double blind, placebo controlled study.

OBJECTIVE: To evaluate the efficacy of intravenous (i.v.) clodronate in patients with reflex sympathetic dystrophy syndrome (RSDS) and to assess the urinary excretion of type I collagen crosslinked N-telopeptide (NTx) before and after the treatment. METHODS: Thirty-two patients with RSDS were randomized to receive either i.v. clodronate 300 mg daily for 10 consecutive days or placebo. Forty days later, the placebo treated patients received the clodronate treatment. Outcome measures included as a primary endpoint the visual analog scale of pain (VAS, range 0-100); secondary endpoints were a clinical global assessment (CGA, range 0-3) and an efficacy verbal score (EVS, range 0-3). Clinical and biochemical assessments were performed before the treatment, 40 (T40), 90 (T90), and 180 (T180) days later. RESULTS: At T40 the 15 patients randomized to clodronate treatment showed significant decreases of VAS and CGA (p = 0.002, p = 0.001, respectively). Compared with the placebo group (17 patients), significant differences were found in all clinical variables (VAS: p = 0.001; CGA: p = 0.001; EVS: p<0.0001). A further clinical improvement was observed throughout the study. Pooling the results of all 32 patients after clodronate treatment, at T180 the overall percentage decrease of VAS was 93.2+/-15.6%, with 30 patients significantly improved or asymptomatic. Significant inverse correlations between baseline NTx values and decreases of VAS were found at T90 (p = 0.03) and T180 (p = 0.01). No adverse events related to treatment occurred. CONCLUSION: A 10 day i.v. clodronate course is better than placebo and effective in the treatment of RSDS. NTx seems to be a predictive factor for clodronate efficacy.

Prevalence of osteoporosis by educational level in a cohort of postmenopausal women.

To evaluate whether the prevalence of osteoporosis and related risk factors might be influenced by the level of education, as has been demonstrated for many other chronic diseases, 6160 postmenopausal women at their first densitometric referral were interviewed about reproductive variables, past and current use of estrogens, prevalence of chronic diseases, and lifestyle factors such as calcium intake, physical activity, smoking and overweight. This sample was stratified by years of formal education. Densitometric evaluation was performed by dual-energy X-ray absorptiometry. Age at menarche, past exposure to oral contraceptives, use of hormone replacement therapy, prevalence of chronic diseases, physical activity, overweight and smoking showed significant trends according to the years of education. The prevalence of osteoporosis showed an inverse relationship with level of education, ranging from 18.3% for the most educated to 27.8% for the least educated women. Multiple logistic regression analysis demonstrated a predictive role toward osteoporosis by age, age at menarche and menopause, hormone replacement therapy, calcium intake, physical activity and body mass index. Using the lowest educational level as reference category, increases in educational status were associated with a significantly reduced risk for osteoporosis (OR = 0.76, 95% CI 0.65-0.90 for 6-8 years of schooling; OR = 0.68, 95% CI 0.57-0.82 for 9 years or more). This study shows differences in the prevalence of osteoporosis among educational classes and the protective role played by increases in formal education. If these results are confirmed in other population studies, public health intervention programs will have to consider the socioeconomic and cultural background of the population strata that run a greater risk of osteoporosis.

Bone mineralization and body composition in young patients with celiac disease.

OBJECTIVES: The aim of the study was to establish whether body composition in patients with celiac disease is normal and influenced by the age at diagnosis or by the duration of the gluten free diet. METHODS: A group of 66 children with celiac disease and 76 healthy controls were studied by dual energy x-ray absorptiometry. We compared celiac patients with the control group, and within the celiac disease group, we compared patients with different age at diagnosis (28 diagnosed in the first 24 months vs 38 later) and with different duration of the diet (16 in gluten free diet for less than 12 months, 11 for less than 24 months, and 39 for more than 24 months). RESULTS: Overall we did not find any significant difference in body composition between overall celiac patients and controls. However the fat mass, the body mass index, and the spine bone mineral density values in late diagnosed celiac patients were significantly lower than in early diagnosed patients (significance values were p < 0.009; p < 0.002; p < 0.002, respectively). Patients on diet for less than 12 months showed significantly lower bone mineral content and density than those on diet for more than 24 months (significance values were, respectively, p < 0.011 and p < 0.022). Spine mineral density was the only parameter significantly influenced both by age at diagnosis (p < 0.03) and duration of gluten free diet (p < 0.008). CONCLUSIONS: Only an early diagnosis of celiac disease in pediatric age and a strict gluten free diet, lasting more than 12 months, allow celiac patients to reach a normal mineralization.

Expression of properly folded human glutamate decarboxylase 65 as a fusion protein in Escherichia coli.

Autoantibodies to the islet-cell 65-kDa variant of glutamate decarboxylase (GAD65) are found in most insulin-dependent diabetes mellitus (IDDM) patients many years before the appearance of clinical symptoms of the disease. As IDDM-preventive therapies may be available in the future, an international effort is taking place to develop widely applicable anti-GAD immunochemical tests. These tests would help to detect individuals at risk before the full installation of the disease and to enroll them in prevention programs. Autoantibodies to GAD65 are mostly directed to conformational epitopes, and the enzyme is a complex molecule with a prosthetic group and 15 cysteine residues. Thus, the conformational integrity of GAD65 is essential for an appropriate anti-GAD assay. Isolation of large amounts of GAD65 from pancreas or other tissues is impractical, and no successful production of properly folded GAD65 has been reported in bacteria. Native recombinant GAD65 for immunochemical tests is usually obtained from eukaryotic expression systems. Since the large-scale production of a recombinant protein in an eukaryotic system is expensive and technically difficult, we investigated the expression of GAD65 in Escherichia coli as an alternative. A number of DNA constructs intended to export the enzyme to the periplasmic space or to improve its cytoplasmic solubility were designed and tested. Our results provide a solution to the two main problems associated with the expression of GAD65 in E. coli: misfolding, leading to the formation of inclusion bodies; and the presence of alternative initiation sites for translation that causes the preferential production of truncated variants of GAD65. We describe here the production of properly folded, fully active, and immunochemically competent GAD65 as an N-terminal fusion protein with thioredoxin. An account of the reactivity of the produced protein with sera of six IDDM patients is also presented.

Computational characterisation of potential RNA-binding sites in arenavirus nucleocapsid proteins.

A nucleocapsid protein of an RNA virus was characterised using computational methods. Similarity searches using standard algorithms and more sensitive methods based on profiles were performed. Also, secondary structure prediction and statistical methods were used. The results show that the protein belongs to a unique well-characterised family, with three regions with potential RNA binding capacity. The amino-terminal region is found to contain a mixed-charge segment similar to proteins that bear nucleic acid-protein interaction capacity. The middle-region has a slight homology to the nucleolar protein Fibrillarin containing an atypical RNP-1 conserved octamer. Finally, the carboxyl-terminal region has a putative zinc-finger.

Short courses of intravenous clodronate in the treatment of Paget's disease of bone: a long-term follow-up trial.

The effect of short-term treatment with intravenous clodronate (300 mg daily for 10 days) was assessed in 12 patients with active Paget's disease of bone. The treatment was found to be associated with a marked reduction in serum alkaline phosphatase levels, from 330 U/l +/- 247 (S.D.) at baseline to 225 +/- 86 on day 11. These levels decreased further during the subsequent 2 months, to stabilize thereafter within the normal range (30-100 U/l)during the entire 1-year follow-up period. No changes were observed in serum calcium and phosphorus levels, whereas serum parathyroid hormone increased significantly on day 11. It is concluded that short-term i.v. treatment with clodronate provides an effective alternative to oral treatment and achieves complete remission of Paget's disease for at least 1 year.

Electron impact mass spectrometry of maleimycin.

The mass spectrometric behaviour of maleimycin, a bicyclic maleimide antibiotic, is discussed in detail with the aid of exact mass measurements, metastables (linked scans B/E and B2/E), ionization and appearance energy measurements and deuterium labelling experiments. The unusual loss of NH3 from the molecular ion is highlighted and a possible mechanism is proposed.

On the synthesis of serine and homoserine samples asymmetrically labelled with tritium and deuterium in the hydroxymethylene group.

(1R) [1-3H, 2H1] 3-Phenylpropanol, the key intermediate in the synthesis of (4R) [4-3H, 2H1] D,L-homoserine and of the (4S)-isomer, is obtained from (1S) [1-2H1] 3-phenylpropanol and (1RS) [1-3H] ethanol upon incubation with yeast alcohol dehydrogenase and NAD+; under similar conditions 2-phenylethanol undergoes very small exchange with [1-2H2] ethanol.