Effects of oral contraceptive use on body mass index and blood pressure among female villagers in north-east Thailand

The use of contraceptives has become prevalent among females in Thailand in the past 20 years, and oral contraceptive use has been suggested to trigger changes in fat intake, energy expenditure, fat metabolism and blood pressure. Based on field investigations of 391 married women aged 20 years or over in Yasothon Province, North-east Thailand, this study aims to elucidate the effects of oral contraceptive use on body mass index (BMI: kg/m2) and blood pressure, taking into account reproductive histories and socioeconomic conditions. The proportion of obese (BMI > or = 25) subjects was high in the age groups 30-39, 40-49 and 50-59, accounting for, respectively, 39.4%, 51.1% and 48.5% of these populations. The proportion of women with hypertension (90/140 mmHg) was 23.7%, 18.5% and 26.2% in the 40-49, 50-59 and 60-69 age groups. Current contraceptive practices in the studied population included sterilization by operation, oral contraception and injection. These methods accounted for 43.0%, 12.8% and 8.2% of the population, respectively. Sociodemographic factors such as reproductive history, years of education and household income were not significantly related to BMI or to blood pressure (ANOVA with age adjustment). In contrast, oral contraceptive users had significantly higher BMIs and diastolic blood pressures (p<0.01, ANOVA with age adjustment). Multiple regression analysis also revealed that oral contraceptive use was a weak but significant contributing factor to both high BMI and blood pressure when sociodemographic factors were taken into account and controlled for statistically. It can thus be concluded that the use of contraceptive pills, which contain oestrogen and progestin and are provided free of charge to Thai women, tend to increase BMI and to elevate blood pressure.     

Cryptic epitopes in N-terminally truncated prion protein are exposed in the full-length molecule: dependence of conformation on pH

Prion diseases are diseases of protein conformation. Structure-dependent antibodies have been sought to probe conformations of the prion protein (PrP) resulting from environmental changes, such as differences in pH. Despite the absence of such antibodies for full-length PrP, a recombinant Fab (D13) and a Fab derived from mAb 3F4 showed pH-dependent reactivity toward epitopes within the N-terminus of N-terminally truncated PrP(90-231). Refolding and maintaining this protein at pH > or =5.2 before immobilization on an ELISA plate inhibited reactivity relative to protein exposed to pH < or =4.7. The reactivity was not affected by pH changes after immobilization, showing retention of conformation after binding to the plate surface, although guanidine hydrochloride at 1.5-2 M was able to expose the cryptic epitopes after immobilization at pH > or =5.2. The alpha-helical CD spectrum of PrP(90-231) refolded at pH 5.5 was reduced somewhat by these pH changes, with a minor shift toward beta-sheet at pH 4 and then toward coil at pH 2. No covalent changes were caused by the pH differences. This pH dependence suggests titration of an acidic region that might inhibit the N-terminal epitopes. A similar pH dependence for a monoclonal antibody reactive to the central region identified an acidic region incorporating Glu152 as a significant participant.     

Mutation of an arginine biosynthesis gene causes reduced pathogenicity in Fusarium oxysporum f. sp. melonis

Restriction enzyme-mediated integration (REMI) mutagenesis was used to tag genes required for pathogenicity of Fusarium oxysporum f. sp. melonis. Of the 1,129 REMI transformants tested, 13 showed reduced pathogenicity on susceptible melon cultivars. One of the mutants, FMMP95-1, was an arginine auxotroph. Structural analysis of the tagged site in FMMP95-1 identified a gene, designated ARG1, which possibly encodes argininosuccinate lyase, catalyzing the last step for arginine biosynthesis. Complementation of FMMP95-1 with the ARG1 gene caused a recovery in pathogenicity, indicating that arginine auxotrophic mutation causes reduced pathogenicity in this pathogen.     

Distribution of interstitial telomere-like repeats and their adjacent sequences in a dioecious plant, <Emphasis Type="Italic">Silene latifolia</Emphasis>

The dioecious plant Silene latifolia has large, heteromorphic X and Y sex chromosomes that are thought to be derived from rearrangements of autosomes. To reveal the origin of the sex chromosomes in S. latifolia, we isolated and characterized telomere-homologous sequences from intra-chromosomal regions (interstitial telomere-like repeats; ITRs) and ITR-adjacent sequences (IASs). Nine genomic DNA fragments with degenerate 84- to 175-bp ITRs were isolated from a genomic library and total genome of male plants. Comparing the nucleotide sequences, the IASs of the nine ITRs were classified into seven elements (IAS-a, IAS-b, IAS-c, IAS-d, IAS-e, IAS-f, and IAS-g) by sequence similarity. The ITRs were grouped into two classes (class-I and -II ITRs) according to the classification of IASs. The class-I ITRs were sub-grouped into three subclasses (subclasses-IA, -IB, and -IC ITRs) based on the arrangement of IAS elements. By contrast, the class-II ITR was located between two different IASs (IAS-f and IAS-g). Genomic Southern analyses showed that both the male and female genomes contained six (IAS-f) to 153 (IAS-d) copies of each IAS per haploid genome. Fluorescence in situ hybridization analyses showed that one IAS element, IAS-d, was distributed in the interstitial and proximal regions of the sex chromosomes of S. latifolia. The distribution of IAS-d is important evidence for past telomere-mediated chromosome rearrangements during the evolution of the sex chromosomes of S. latifolia.     

Time of day improves efficacy and reduces adverse reactions of vitamin D3 in 5/6 nephrectomized rat

Time-dependent differences in adverse reactions and efficacy by a repeated administration of 1,25(OH)2 vitamin D3 (vit D, 0.3 microg/Kg/day for 12 weeks) were examined in 5/6 nephrectomized rats under a condition of 12-hour light-dark cycle. The 5/6 nephrectomy increased serum concentrations of phosphate, osteocalcin and PTH, and urinary excretions of phosphate and deoxypyridinoline (DPD) while the maneuver reduced serum Ca concentration and its urinary excretion. Animals with a dosing of the drug at 2 hours after light on (HALO) had more grade of hypercalcemia and hyperphosphatemia than those at 14 HALO. Reduction of serum intact PTH and increase of serum vit D were observed in both groups with a similar extent. Increase of osteocalcin by the drug was greater in 14 HALO trial. Urinary excretion of DPD was not influenced by the treatment. The increase in bone density of femur was greater in 14 HALO than in 2 HALO trials. These results suggest that adverse reactions of vit D were ameliorated and its efficacy was enhanced after the repeated dosing of the drug at 14 HALO. Time-dependent variation in the sensitivity of the drug to osteoblast was involved in the mechanism of these events, while the roles of pharmacokinetic alteration and renal response were small, if any.     

A case of acute gastric mucosal lesions associated with Helicobacter heilmannii infection

A 69-year-old-woman presented with acute epigastric pain, nausea, vomiting and heartburn. Endoscopy disclosed acute gastric mucosal lesions including mucosal edema, erosions, and ulcers with blood crusts in the antrum. Touch cytology and histological assessment obtained from the affected mucosa revealed acute neutrophilic gastritis and single longer and more coiled organisms than Helicobacter pylori, suggesting Helicobacter heilmannii. Electron micropragh confirmed the characteristic morphology. Despite a positive rapid urease test, H. pylori was not isolated by culture or detected by histology and Gram smears. Based on these findings, a diagnosis of acute gastric mucosal lesions associated with H. heilmannii infection was established. This was successfully treated with a 2-week triple therapy consisting of lansoprazole, clarithromycin and metronidazole with persistent endoscopic and histological remission. This is a rare case of H. heilmannii-associated acute gastric mucosal lesions, diagnosed by morphology using touch cytology and histology. The patient might benefit from antimicrobial treatment employing the regimen effective for H. pylori.     

DNA aqueous solution used for dialytical removal and enrichment of dioxin derivatives

In the present study, a dialytic method that uses a DNA aqueous solution to remove and enrich dioxins from polluted water was proposed. Circular dichroism (CD) and fluorescent spectra indicated that dibenzo-p-dioxin (DD), dibenzofuran (DF) and biphenyl (BP), which are dioxin derivatives, form complexes with DNA. Their experimental dialytic sorption coefficients were measured by quantifying the concentrations of DD, DF, and BP in aqueous solutions before and after dialysis of the DNA solution, and the values were 2.1×10⁵, 1.3×10⁵, and 1.5×10⁷, respectively. As a simulated water treatment model, DNA solution was dialyzed in an aqueous mixture of DD, DF, and BP for 96 h, the HPLC studies showed that the dioxin derivatives have been concentrated in the DNA solution about 200 times. The dialyzed DNA solution was reusable by an extraction with hexane.     

A gene for a Class II DNA photolyase from<Emphasis Type="Italic"> Oryza sativa</Emphasis>: cloning of the cDNA by dilution-amplification

Ultraviolet radiation induces the formation of two classes of photoproducts in DNA-the cyclobutane pyrimidine dimer (CPD) and the pyrimidine [6-4] pyrimidone photoproduct (6-4 product). Many organisms produce enzymes, termed photolyases, which specifically bind to these lesions and split them via a UV-A/blue light-dependent mechanism, thereby reversing the damage. These photolyases are specific for either CPDs or 6-4 products. Two classes of photolyases (class I and class II) repair CPDs. A gene that encodes a protein with class II CPD photolyase activity in vitro has been cloned from several plants including Arabidopsis thaliana, Cucumis sativus and Chlamydomonas reinhardtii. We report here the isolation of a homolog of this gene from rice (Oryza sativa), which was cloned on the basis of sequence similarity and PCR-based dilution-amplification. The cDNA comprises a very GC-rich (75%) 5; region, while the 3; portion has a GC content of 50%. This gene encodes a protein with CPD photolyase activity when expressed in E. coli. The CPD photolyase gene encodes at least two types of mRNA, formed by alternative splicing of exon 5. One of the mRNAs encodes an ORF for 506 amino acid residues, while the other is predicted to code for 364 amino acid residues. The two RNAs occur in about equal amounts in O. sativa cells.