Tomoki Yabutani

Alterations in serum levels of trace elements in tuberculosis and HIV infections

Objective:To evaluate serum concentrations of trace elements in tuberculosis (TB) patients with or with out human immunodeficiency virus (HIV) coinfection before and after anti-TB chemotherapy.Subjects:A total of 155 TB patients, 74 of which were coinfected with HIV, and 31 healthy controls from Gondar, Ethiopia.Methods:Serum levels of copper, zinc, selenium and iron were determined using an inductively coupled plasma mass spectrometer from all subjects at baseline and from 44 TB patients (22 with HIV coinfection) at the end of an intensive phase of anti-TB chemotherapy.Results:Compared with the control group, the concentrations of iron, zinc and selenium were significantly lower (P<0.05) while that of copper and copper/zinc ratio was significantly higher (P<0.05) in the serum of TB patients. TB patients with HIV coinfection had significantly lower serum zinc and selenium concentrations and significantly higher copper/zinc ratio compared to that in TB patients without HIV coinfection (P<0.05). The serum concentration of zinc had significantly increased at the end of intensive phase of anti-TB chemotherapy in patients without HIV coinfection (P<0.05). An increase in serum selenium level was observed in TB patients with or without HIV coinfection after therapy. On the contrary, serum copper concentration and copper/zinc ratio declined significantly after anti-TB chemotherapy irrespective of HIV serostatus (P<0.05).Conclusions:The results indicate that TB patients have altered profile of trace elements in their sera. This warrants the need for further investigations so that strategies for trace elements supplementation can be planned in addition to their potential as diagnostic parameters in monitoring responses to anti-TB chemotherapy.

Micronutrient levels and nutritional status of school children living in Northwest Ethiopia

BackgroundSeveral micronutrients are essential for adequate growth of children. However, little information is available on multiple micronutrient status of school children in Ethiopia. The present study was designed to evaluate the relationship between multiple micronutrient levels and nutritional status among school children.MethodIn this cross-sectional study, anthropometric data, blood and stool samples were collected from 100 children at Meseret Elementary School in Gondar town, Northwest Ethiopia. Serum concentration of magnesium, calcium, iron, copper, zinc, selenium and molybdenum were measured by inductively coupled plasma mass spectrometer. Anthropometric indices of weight-for-age, height-for-age and BMI-for-age were used to estimate the childrens nutritional status. Stool samples were examined by standard microscopic methods for intestinal parasites.ResultsThe prevalence of stunting, underweight, wasting and intestinal parasitoses among school children was 23%, 21%, 11% and18%, respectively. The mean serum levels of magnesium, calcium, iron, copper, zinc, selenium and molybdenum were 2.42±0.32 (mg/dl), 15.31±2.14 (mg/dl), 328.19±148.91 (μg/dl), 191.30±50.17 (μg/dl), 86.40±42.40 (μg/dl), 6.32±2.59 (μg/dl), and 0.23±0.15 (μg/dl), respectively. Selenium deficiency, zinc deficiency and magnesium deficiency occurred in 62%, 47%, and 2% of the school children, respectively. Height-for-age showed significant positive correlation with the levels of copper and molybdenum (p = 0.01) and with the levels of magnesium (p = 0.05).ConclusionDeficiencies of selenium and zinc were high among the school children although the deficiencies were not significantly related with their nutritional status. The prevalence of both malnutrition and intestinal parasitism was not negligible. These calls for the need to undertake multicentre studies in various parts of the country to substantiate the data obtained in the present study so that appropriate and beneficial strategies for micronutrient supplementation and interventions on nutritional deficiencies can be planned.

Serum Zinc, Copper, Selenium, Calcium, and Magnesium Levels in Pregnant and Non-Pregnant Women in Gondar, Northwest Ethiopia

Pregnant women in developing countries are vulnerable to multiple micronutrient deficiencies. Studies assessing serum levels of the micronutrients and magnitude of their deficiencies are very scarce in African subjects. This study was aimed at determining serum levels of micronutrients in 375 pregnant (42 HIV seropositive) and 76 non-pregnant women (20 HIV seropositive) who visited the University of Gondar Hospital, Gondar, Ethiopia. Serum concentrations of zinc,\ copper, selenium, calcium, and magnesium were determined using an inductively coupled plasma mass spectrometer. Irrespective of HIV serostatus, pregnant women had significantly higher serum concentrations of copper and copper/zinc ratio and significantly lower magnesium compared to those in non-pregnant women (P < 0.05). Except for selenium, which was significantly lower in HIV-seropositive pregnant women (P < 0.05), the mean serum concentrations of zinc, copper, calcium, and magnesium were not significantly different between pregnant women by HIV serostatus. The prevalence of deficiency in zinc, magnesium, selenium, and calcium in the pregnant women, irrespective of their HIV serostatus, was 66.7%, 25.6%, 21.9%, and 9.3%, respectively. The magnitude of deficiency in zinc, magnesium, and selenium was significantly higher in HIV seropositive pregnant women (76.2%, 52.4%, and 45.2%) than that in HIV-seronegative pregnant women (65.5%, 22.2%, and 18.9%) and in HIV-seronegative non-pregnant women (42.9%, 8.1%, and 30.4%; P < 0.05). Deficiency in one, two, three, or four mineral elements was observed in 44.8%, 14.4%, 9.9%, and 5.1% of the pregnant women, respectively. Only 25.9% of the pregnant women and 44.7% of the non-pregnant women were not deficient in any of the micronutrients. The high prevalence of micronutrient deficiencies in pregnant and non-pregnant women in Gondar, Ethiopia warrants the need for strategies on prevention and control of the deficiencies.

Serum levels of trace elements and iron-deficiency anemia in adult Vietnamese.

This study was aimed at assessing the serum levels of vitamin A, copper, zinc, selenium, and iron among adult Vietnamese with and without iron-deficiency anemia. Blood was collected from adult Vietnamese living in the midland of northern Vietnam. One hundred twenty-three subjects in the age range 20–60 yr were included in the study. Anemia, where the concentration of hemoglobin in whole blood is less than 120 g/L in females and 130 g/L in males, was found in 30% (37/123) of the study population. The levels of vitamin A and selenium in the sera of anemic subjects (n=37) were significantly lower than that in nonanemic group (n=86). On the other hand, no significant differences were observed in the concentrations of copper and zinc between the two groups. This study was the first to show serum levels of trace elements in adult Vietnamese, providing useful baseline information for further studies.

Catalytic properties and crystal structure of quinoprotein aldose sugar dehydrogenase from hyperthermophilic archaeon Pyrobaculum aerophilum

We identified a gene encoding a soluble quinoprotein glucose dehydrogenase homologue in the hyperthermophilic archaeon Pyrobaculum aerophilum. The gene was overexpressed in Escherichia coli, after which its product was purified and characterized. The enzyme was extremely thermostable, and the activity of the pyrroloquinoline quinone (PQQ)-bound holoenzyme was not lost after incubation at 100 degrees C for 10 min. The crystal structure of the enzyme was determined in both the apoform and as the PQQ-bound holoenzyme. The overall fold of the P. aerophilum enzyme showed significant similarity to that of soluble quinoprotein aldose sugar dehydrogenase (Asd) from E. coli. However, clear topological differences were observed in the two long loops around the PQQ-binding sites of the two enzymes. Structural comparison revealed that the hyperthermostability of the P. aerophilum enzyme is likely attributable to the presence of an extensive aromatic pair network located around a beta-sheet involving N- and C-terminal beta-strands.

Removal of Phosphate in Water to Layered Double Hydroxide

Layered double hydroxide (LDH) has been used to remove phosphate ion in water as an effective adsorbent of this anion at low concentration. LDH which contains Mg2+ and Al3+ as divalent and trivalent metals respectively was prepared as has been published by many authors. A fixed portion of this LDH was suspended in the weakly basic solution containing phosphate. The suspension was stirred moderately followed by filtration. The concentration of phosphate ion in the filtrate was determined by the molybdenum blue method. The result indicates that the LDH used in this experiment was effective in removing phosphate from water. Furthermore, it was also certified that the phosphate anions removed from water were quantitatively transferred onto the solid of LDH.

Development of a D-amino acids electrochemical sensor based on immobilization of thermostable D-Proline dehydrogenase within agar gel membrane

A novel biosensor for determination of d-amino acids (DAAs) in biological samples by using an electrode based on immobilization of a thermostable d-Proline dehydrogenase (d-Pro DH) within an agar gel membrane was developed. The electrode was simply prepared by spin-coating the agar solution with the d-Pro DH on a glassy carbon (GC) electrode. An electrocatalytic oxidation current of 2,6-dichloroindophenol (DCIP) was observed at -100mV vs. Ag/AgCl with the addition of 5 and 20mmolL(-1)d-proline. The current response and its relative standard deviation were 0.15muA and 7.6% (n=3), respectively, when it was measured in a pH 8.0 phosphate buffer solution containing 10mmolL(-1)d-proline and 0.5mmolL(-1) DCIP at 50 degrees C. The current response of d-proline increased with increase of the temperature of the sample solution up to 70 degrees C. The electrocatalytic response at the d-Pro DH/agar immobilized electrode subsequently maintained for 80 days. Finally, the d-Pro DH/agar immobilized electrode was applied to determination of DAAs in a human urine sample. The determined value of DAAs in the human urine and its R.S.D. were 1.39+/-0.12mmolL(-1) and 8.9% (n=3), respectively.

RECOVERY AND EXTRACTION OF HEAVY METAL IONS USING IONIC LIQUID AS GREEN SOLVENT

Ionic liquids are expected to replace conventional organic solvents in organic synthesis, solvent extraction and electrochemistry due to their unique characters such as low volatility, high stability and so on. In this work, N,N,-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethansulfonyl)imide was used as an alternative solvent to extract heavy metal ions. As the extracting conditions, the additional effect of 8-hydroxyquinoline (8-HQ) as metal chelating agent into ionic liquids, shaking time and volume ratio were investigated. As extraction efficiency depended on 8-HQ concentration significantly, in order to extract high concentrated metal ions the solubility of 8-HQ into ionic liquid was tested. N,N,-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethansulfonyl)imide had good solubility of 8-HQ. Consequently, 5 μmol of copper, zinc, cadmium and manganese could be completely recovered with 100 μl of ionic liquid.

Association of low serum selenium with anemia among adolescent girls living in rural Vietnam.

OBJECTIVE We investigated the prevalence of anemia and deficiency in trace elements in adolescent girls living in rural Vietnam. METHODS Two hundred forty-five adolescent girls 11-17 y of age from three schools in rural province of Ha Nam, Vietnam, were assessed. RESULTS The prevalence of anemia was 20.4%. The incidences of low serum selenium (Se), zinc, and copper in subjects were 15.9%, 26.5%, and 4.1%, respectively. The parameter significantly associated with anemia was the low serum levels of Se and vice versa (odds ratio [OR] 5.36, 95% confidence interval [CI] 2.57-11.18, P < 0.0001). Other risk factors for anemia were a body mass index <17.00 kg/m(2) (OR 2.72, 95% CI 1.37-5.37, P = 0.004) and years of age (OR 1.35, 95% CI 1.14-1.59, P < 0.001). A body mass index <17.00 kg/m(2) (OR 2.65, 95% CI 1.25-5.61, P = 0.011) was also found to be a risk factor for low serum Se. CONCLUSION The findings of the present study demonstrate that low serum Se is independently associated with anemia in adolescent girls living in rural Vietnam. Interventions are required to gain insight into the potential role of Se on prevention and control of anemia.

Serum Concentration of Selenium in Diarrheic Patients with and without HIV/AIDS in Gondar, Northwest Ethiopia

Background: Selenium deficiency is known to be a major public health problem, associated with increased risk of mortality with AIDS and AIDS-related complex, diarrhea included compared to those of healthy controls. In Ethiopia, there are no studies conducted on serum selenium status diarrheic patients with and without HIV infection. Therefore, the present study was aimed at determining the level of serum selenium in HIV infected and sex and aged matched HIV negative diarrheic patients.. Methods: This was a cross-sectional study of 206 (97 HIV seronegative and 109 HIV seropositive) diarrheic patients of both genders seen at University of Gondar Hospital, Gondar, Ethiopia. Serum selenium was measured by inductively coupled plasma-mass spectrometer. Results: The mean and standard deviation of serum selenium levels in HIV seropositives was 5.90 ± 2.78 μg/dl and in HIV seronegatives was 6.99 ± 4.26 μg/dl. Deficiency of selenium was seen in 95.9% and 71.56% of diarrheic patients with and without HIV co-infection, respectively. The over all selenium deficiency was observed in 83.0% of patients included in the study irrespective of their HIV serostatus while 85.3%of the patients infected with HIV and 80.4% of patients without HIV infection had serum selenium level below 7μg/dl. The low serum selenium level was not associated with presence or absence of intestinal parasites neither with sociodemographic variables such as age, residence, marital status, occupation, monthly income. The mean serum selenium level of all male cases was statistically significantly lower than that of the females (P<0.05). Conclusion: Our results show high prevalence of selenium deficiencies in HIV seropositive and seronegative diarrheic patients in Gondar, Ethiopia. Although this is a small group of study subjects, the findings may be used as a tool to suggest further in-depth prospective clinical trials to determine whether selenium supplements may be of public health benefit among HIV-infected populations as a stand-alone therapeutic approach and potentially as an adjuvant to antiretroviral therapy.