Compliance and its Determinants Regarding Iron and Folic Acid Supplementation during Pregnancy in Kathmandu, Nepal.

Background Iron deficiency anemia is one of the major public health problems mostly affecting pregnant women of developing countries like Nepal. Kathmandu, the capital city of Nepal, has considerably high prevalence of anemia, which is attributed to inadequate dietary iron and problems of compliance to iron and folic acid supplementation. Objective This descriptive study aimed to identify the levels of and determinants associated with compliance regarding Iron and folic acid supplementation among pregnant women in Kathmandu, Nepal. Method The study was conducted in Paropakar Maternity and Women's Hospital in Kathmandu. Systematic random sampling was done to select a total of 406 samples that were either handed questionnaire for self-administration or interviewed. The χ2 test and multiple linear regressions were used for statistical analysis. Result The findings showed 73.2% of the respondents had high compliance, 12.8% moderate compliance, and 14% low compliance to iron and folic acid supplementation. More than half of the respondents had insufficient knowledge regarding anemia, iron deficiency and iron and folic acid supplementation. Multiple linear regression revealed that perceived severity, perceived barriers and social support were determinants of compliance to iron and folic acid supplementation (p<0.05). Conclusion This study infers that there is a lack of knowledge and awareness regarding anemia, iron deficiency, and iron and folic acid supplementation among pregnant women, and improvement in social support and perception of severity of the disease, and minimization of associated barriers may lead to better outcome in terms of compliance to iron and folic acid supplementation among pregnant women.

Comparison of long-term results of laparoscopic and endoscopic exploration of common bile duct.

BACKGROUND: To compare long term results of laparoscopic and endoscopic exploration of common bile duct, to assess post-procedure quality of life. MATERIALS AND METHODS: From September 1992 to August 2003, we performed 4058 cholecystectomies, out of which 479 (11.80%) patients had choledocholithiasis. There were 163 males and 316 females. Mean age was 63.65 ± 5.5 years. These patients were put in two groups. In the first group of 240 patients, a majority of patients underwent two-stage procedures. ERCP/ES was performed in 210 (87.50%) cases. In the second group of 239 patients, a majority of patients underwent single-stage procedures. ERCP/ES was done in 32 (13.38%) cases. RESULTS: Mortality was zero in both groups. Morbidity was 15.1% in first group and 7.5% in second group. Mean hospital stay was 11.7 ± 3.2 days in first group and 6.2 ± 2.1 days in second group. Average operative time was 95.6 ± 20 minutes in first group and 128.4 ± 32 minutes in second group. Completed questionnaires received from 400 (83.50%) patients revealed better long-term results in the second group. Clinical features of low-grade cholangitis were seen in 20% of patients who underwent ES. Hence the post-procedure quality of life in patients who underwent single-stage procedures was definitely much better, because of minimal damage of sphincter of Oddi. CONCLUSIONS: Single-stage laparoscopic operations provide better results and shorter hospital stay. Damage to sphincter of Oddi should be minimal, to avoid long-term low-grade cholangitis. In young patients, the operation of choice should be single-stage laparoscopic procedure with absolutely no damage to sphincter of Oddi.

Conformational dynamics of a transposition repressor in modulating DNA binding.

The repressor of bacteriophage Mu functions in the establishment and maintenance of lysogeny by binding to Mu operator DNA to shut down transposition. A domain at its N terminus functions in DNA binding, and temperature-sensitive mutations in this domain can be suppressed by truncations at the C terminus. To understand the role of the C-terminal tail in DNA binding, a fluorescent probe was attached to the C terminus to examine its environment and its movement with respect to the DNA binding domain. The emission spectrum of this probe indicated that the C terminus was in a relatively hydrophobic environment, comparable to the environment of the probe attached within the DNA-binding domain. Fluorescence of two tryptophan residues located within the DNA-binding domain was quenched by the probe attached to the C terminus, indicating that the C terminus is in close proximity to this domain. Addition of DNA, even when it did not contain operator DNA, reduced quenching of tryptophan fluorescence, indicating that the tail moves away from the DNA-binding domain as it interacts with DNA. The presence of the tail also produced a trypsin hypersensitive site within the DNA-binding domain; mutant repressors with an altered or truncated C terminus were relatively resistant to cleavage at this site. Interaction of the wild-type repressor with DNA greatly reduced cleavage at the site. A repressor with a temperature-sensitive mutation in the DNA-binding domain was especially sensitive to cleavage by trypsin even in the presence of DNA, and the C-terminal tail failed to move in the presence of DNA at elevated temperatures. These results indicate that the tail sterically inhibits DNA binding and that it moves during establishment of repression. Such conformational changes are likely to be involved in communication between repressor protomers for cooperative DNA binding.

Brain blood flow changes in depressed patients treated with interpersonal psychotherapy or venlafaxine hydrochloride: preliminary findings.

BACKGROUND: Functional brain imaging studies in major depression have suggested abnormalities of areas, including the frontal cortex, cingulate gyrus, basal ganglia, and temporal cortex. We hypothesized that venlafaxine hydrochloride and interpersonal psychotherapy (IPT) might each alter brain blood flow in some or all of these areas on sequential single photon emission computed tomography (SPECT) scans. METHODS: Twenty-eight men and women aged 30 to 53 years with a DSM-IV major depressive episode, a 17-item Hamilton Rating Scale for Depression (HAM-D) rating of 18 or higher, and antidepressant-naive for at least 6 months were studied. After baseline (99m)technetium-hexa-methyl-propylene-amine-oxime scan, 1-T magnetic resonance imaging, and psychometric ratings, patients were assigned to different treatments. Thirteen patients had 1-hour weekly sessions of IPT from the same supervised therapist (E.M.). Fifteen patients took 37.5 mg twice-daily of venlafaxine hydrochloride. Single-photon emission computed tomography scans and ratings were repeated at 6 weeks. RESULTS: Both treatment groups improved substantially, more so with venlafaxine (mean [SD] HAM-D scores at pretreatment: IPT, 22.7 [2.7], and venlafaxine, 22.4 [3.1]; and posttreatment: IPT, 16.2 [7.1], and venlafaxine, 10.9 [8.6]). No patients had structural brain abnormalities. On analysis with statistical parametric mapping 96, the venlafaxine group showed right posterior temporal and right basal ganglia activation (P =.01), while the IPT group had limbic right posterior cingulate and right basal ganglia activation (P =.01). CONCLUSIONS: This preliminary investigation has shown limbic blood flow increase with IPT yet not venlafaxine, while both treatments demonstrated increased basal ganglia blood flow. This was, however, a short trial with a small sample, no control group, and different symptom reduction in the 2 groups.

Localization of critical histidyl residues required for vinblastine-induced tubulin polymerization and for microtubule assembly.

Vinblastine-induced tubulin polymerization is electrostatically regulated and shows pH dependence with a pI approximately 7.0 suggesting the involvement of histidyl residues. Modification of histidyl residues of tubulin with diethylpyrocarbonate (DEPC) at a mole ratio of 0.74 (DEPC/total His residues) for 3 min at 25 degreesC completely inhibited vinblastine-induced polymerization with little effect on microtubule assembly. Under these conditions DEPC reacts only with histidyl residues. For complete inhibition two histidyl residues have to be modified. Demodification of the carboxyethyl histidyl derivatives by hydroxylamine led to nearly complete recovery of polymerization competence. Labeling with [14C]DEPC localized both of these histidyl residues on beta-tubulin at beta227 and beta264. Similarly, tubulin modification with DEPC for longer times (8 min) resulted in complete inhibition of microtubule assembly, at which time approximately 4 histidyl residues had been modified. This inhibition by DEPC was also reversed by hydroxylamine. The third histidyl residue was found on alpha-tubulin at alpha88. Thus, two charged histidyl residues are obligatorily involved in vinblastine-induced polymerization, whereas a different histidyl residue on a different tubulin monomer is involved in microtubule assembly.

The C terminus of beta-tubulin regulates vinblastine-induced tubulin polymerization.

Oligoanions such as sodium triphosphate or GTP prevent and/or reverse vinblastine-induced polymerization of tubulin. We now show that the anions of glutamate-rich extreme C termini of tubulin are similarly involved in the regulation of the vinblastine effect. Cleavage of the C termini by limited proteolysis with subtilisin enhances vinblastine-induced tubulin polymerization and abolishes the anion effect. Only the beta-tubulin C terminus needs to be removed to achieve these changes and the later cleavage of the alpha-tubulin C terminus has little additional effect. In fact, vinblastine concentrations >20 microM block cleavage of the alpha-tubulin C terminus in the polymer, whereas cleavage of the beta-tubulin C terminus proceeds unimpeded over the time used. The vinblastine effect on tubulin polymerization is also highly pH-dependent between pH 6.5 and 7.5; this is less marked, but not absent, after subtilisin treatment. A working model is proposed wherein an anionic domain proximal to the extreme C terminus must interact with a cationic domain to permit vinblastine to promote polymerization. Both exogenous and extreme C-terminal anions compete for the cationic domain with the proximal anionic domain to prevent vinblastine-induced polymerization. We conclude that the electrostatic regulation of tubulin polymerization induced by vinblastine resides primarily in the beta-tubulin C terminus but that additional regulation proximal in the tubulin molecule also plays a role.

Dissociation of tubulin assembly-inhibiting and aggregation-promoting activities by a vinblastine derivative.

A fluorescent vinblastine analogue, vinblastine-4'-anthranilate (Antvin), that binds to the vinca site on tubulin, inhibits tubulin assembly but does not lead to spiral or other large aggregate formation at concentrations up to 1.6 mM. As judged by turbidity, 90 degrees light scattering and fluorescence anisotropy, little aggregation could be detected. This is in marked contrast to vinblastine and suggests that inhibition of assembly and aggregate formation can be dissociated from each other by suitable substitution in vinblastine.

Vinblastine-induced formation of tubulin polymers is electrostatically regulated and nucleated.

Vinblastine promotes tubulin polymerization as measured by turbidity at 400 nm. Unlike microtubule assembly, this mode of polymerization does not require GTP and, in fact, GTP inhibits polymerization, as do other G nucleotides in the potency order: GtetraP > or = GTP > GDP > GMP > no nucleotide. Inhibition is not nucleoside-specific as ATP, ADP, and CTP also inhibit, and inorganic oligophosphates are as inhibitory as nucleotides in the order tetraphosphate approximately triphosphate > pyrophosphate >> phosphate. Inhibition of polymerization is a rough function of the number of anionic charges and can be mimicked by suramin or tartrate. It is not due to sequestration of magnesium or to debinding of vinblastine. The anion-induced decrease in turbidity generation is reflected in the amount of tubulin that is pelletable, but even in the absence of turbidity significant pelletable tubulin persists which can be assessed by 90 degree light scattering. Formation of this polymer is less sensitive to anions. Shearing of GTP-inhibited and vinblastine-induced samples promotes turbidity and addition of seeds made from vinblastine polymers leads to rapid increases in turbidity in a concentration-dependent manner. Adjustment of the vinblastine concentration permits the demonstration of a latent period for polymerization that can be shortened by polymer seeds. Vinblastine-induced polymerization shows a critical concentration, and, in the presence of GTP, two distinct critical concentrations can be identified. We conclude that charge-charge interactions play a significant role in the formation of vinblastine-induced polymers, and that their formation is a two-step process resembling a nucleation/elongation mechanism.

Localization of the vinblastine-binding site on beta-tubulin.

A fluorescent vinblastine derivative, vinblastine-4'-anthranilate, has been shown to inhibit polymerization of rat brain tubulin (IC50 = 4.8 microM). Binding of the drug to tubulin increases fluorescence intensity, causes a small emission blue shift, and has a quantum yield of 0.037. Fluorescence increases as a function of drug concentration, with a high affinity site and an undetermined number of lower affinity sites. Photolabeling, by exciting the fluorescent drug-tubulin complex at the absorption maximum of anthranilate, yields a covalent adduct confined to beta-tubulin. Its formation is specific in that it is blocked by maytansine or vinblastine. Tryptic hydrolysis identifies a single fluorescent beta-peptide coinciding with residues 175-213. The interactions between various ligands at this central portion of beta-tubulin are discussed.

Nucleotide binding to tubulin-investigations by nuclear magnetic resonance spectroscopy.

In an attempt to distinguish between the interaction of GTP and ATP with tubulin dimer, high-resolution 1H- and 31P-NMR experiments have been carried out on the nucleotides in the presence of tubulin. The location of the ATP binding sites on the protein in relation to the GTP sites is still not clear. Using NMR spectroscopy, we have tried to address this question. Evidence for the existence of a site labelled as X-site and another site (labelled as L-site) for both the nucleotides on tubulin has been obtained. It is suggested that this X-site is possibly the putative E-site. In order to gain further insight into the nature of these sites, the Mg(II) at the N-site has been replaced by Mn(II) and the paramagnetic effect of Mn(II) on the linewidth of the proton resonances of tubulin-bound ATP and GTP has been studied. The results show that the L-site nucleotide is closer to the N-site metal ion compared to the X-site nucleotide. On the basis of these results, it is suggested that the L-site of ATP is distinct from the L-site of GTP while the X-site of both the nucleotides seems to be same. By using the paramagnetic effect of the metal ion, Mn(II), at the N-site on the relaxation rates of tubulin-bound ATP at L-site, distances of the protons of the base, sugar and phosphorous nuclei of the phosphorous moiety of ATP, from the N-site metal ion have been mapped. The base protons are approximately equal to 0.8-1 nm from this metal ion site. On the other hand, the phosphorous nuclei of the phosphate groups are somewhat nearer (approximately equal to 0.4-0.5 nm) from the N-site metal ion.

Interaction of Ant-ATP with tubulin: evidence for ATP competition for the GTP E-site on tubulin.

The interaction of the ribose-modified ATP analogue 3'-O-anthraniloyl adenosine 5'-triphosphate (Ant-ATP) with tubulin has been studied using steady-state fluorescence techniques. This analogue inhibits the polymerization of tubulin induced by ATP or GTP. When this analogue binds to tubulin, an increase in the fluorescence intensity of the analogue and a blue shift of about 10 nm in the emission maximum have been observed. It has been found that Ant-ATP binds to tubulin at a single binding site in the hydrophobic region with a dissociation constant of 0.5-1.0 microM. It has been possible to restore the fluorescence emission intensity of the tubulin-bound analogue to that of the free ligand with a concomitant shift in the wavelength of emission maximum to that of the free analogue by displacing the analogue with ATP or GTP. These results can be interpreted to suggest that ATP and GTP compete for the Ant-ATP binding site and that ATP binds at the GTP exchangeable site (E-site).