Structure of a 7Fe ferredoxin from Azotobacter vinelandii

The structure of the 7Fe ferredoxin from Azotobacter vinelandii has been solved from a 3.0-A multiple isomorphous replacement map. The crystals belong to space group P43212 with a = 55.22, c = 95.20 A, and Z = 1. Heavy-atom derivatives were prepared with K2PtCl4,K2[OsO2(OH)4], and Na3RhCl6. Anomalous scattering data were collected for native (Fe) and Pt derivative crystals. The figure of merit for 3,322 reflections to 3.0 A is 0.74. The structure consists of an NH2-terminal core of residues 1-50 which form the Fe-S cluster sites, and a COOH-terminal chain of residues 51-107 which wraps around this core. The [3Fe-3S] cluster is ligated by cysteines 8, 11, 16, 20, and 49 and a sixth ligand which is either glutamic acid 18 or an exogenous small molecule. The [4Fe-4S] cluster is ligated by cysteines 24, 39, 42, and 45. The coordination of both Fe-S centers has been confirmed by fitting of the cluster atoms and residues 1-50 to unbiased 2Fo-Fc Fourier maps at 2.5-A resolution. The structure of the 3Fe center has also been confirmed with anomalous scattering difference Fourier maps using both isomorphous replacement and refined phases. The partially refined structure at 2.5 A (3,490 reflections, 6.0 sigma(F)) has R = 35%.

Assessment with TLD of radiation exposure to staff during radium insertions in cancer of cervix

A radiation protection survey has been carried out using TLD to assess the radiation exposure to staff during radium insertions for cancer of the cervix. The staff monitored were the radiotherapist, anaesthetist and operating theatre assistant. The radiotherapist, who received the highest exposure, had on the average 160 muGy (16 mrad) whole body (chest) dose while the finger tip doses were around 600 muGy (60 mrad) from the insertion of 60 mg radium. TLD was found to be convenient and sensitive for this purpose, including estimation of finger-tip doses. It helps to maintain the confidence of the staff that their doses are "as low as readily achievable" and also offers a means of checking improvements in practice where found necessary.

Iron-sulfur clusters in Azotobacter ferredoxin at 2.5 A resolution

X-ray crystallographic study of the ferredoxin-like protein (iron-sulfur protein III) from Azotobacter vinelandii has been extended to 2.5-A resolution. A 4.0-A resolution electron density map revealed that the molecule contains two Fe-S clusters of differing size and shape separated by 12 A (Stout, C.D. (1979) Nature 279, 83-84). Recent Mössbauer results by Emptage et al. (Emptage, M.H., Kent, T.A., Huynh, B.H., Rawlings, J., Orme-Johnson, W.H., and Münck, E. (1980) J. Biol. Chem. 255, 1793-1796) have shown that the molecule contains 7 iron atoms as a high potential iron protein-like Fe4 center and a novel 3-Fe center. The 2.5-A electron density map shows two distinctly different Fe-S clusters. The larger cluster consists of a tetranuclear [4Fe-4S] core ligated to the protein at each iron atom. The smaller cluster is distinctly planar and cannot be modeled with [2Fe-2S] or [4Fe-4S] structures. The best model for this cluster is a [3Fe-3S] core. The protein makes six contacts with this cluster.

Antibodies to Herpes simplex virus types 1 and 2 in patients with squamous-cell carcinoma of uterine cervix in India

Antibody activity to Herpes simplex virus type-1 (HSV-1) and type-2 (HSV-2) was measured by the indirect hemagglutination (IHA) test in sera from 124 women with squamous-cell carcinoma of the uterine cervix, 46 women with non-cervical cancer and 116 matched normal women. The type-specific antibodies were assayed by IHA inhibition test. The proportion of cervical cancer cases positive for HSV-2 infection was significantly greater than that of non-cervical cancer cases and matched control women. No difference was observed in the percentages positive for HSV-1 infection among the three study groups. The mean titers of antibodies to HSV-1 as well as HSV-2 were significantly higher than the respective titers in the other two study groups. However, determination of type-specific antibodies did not help in establishing evidence for past infection by HSV-2 in patients with cervical cancer, as no type-specific HSV-2 antibodies were produced in 58% of the cases. The cervical cancer cases were also analysed according to clinical staging (Stages 0 to IV) and histological differentiation of squamous-cell carcinoma. Neither the percentage of positives for HSV-2 infection nor HSV-antibody titers varied, either in clinical staging or in histological differentiation of cervical cancer. These findings suggest that HSV-2 may be related to cervical cancer as an etiological agent but not as a passenger virus of carcinomatous tissue.

A Comparative Study on Nutritional Status of Urban and Rural Early Adolescent School Girls of West Bengal, India

Objectives: Adolescents remain largely neglected and especially girl from a deprived section in our society. The present study is an attempt to evaluate the nutritional status of early adolescent school girl from rural and urban areas. The study was, therefore, carried out to determine and compare the nutritional status of adolescent girl attending urban and rural secondary schools in Paschim Medinipur district of West Bengal, India. Methods: Cross-sectional data based on anthropometric measurements (height, weight) was collected from 2545 girls aged 10 to 14 years attending Govt. approved schools in Kharagpur town and Dantan-II block. The nutritional status has been assessed with the help of some anthropometric indices. The weight and height were recorded for each girl, and converted to nutritional indices (weightfor- age, height-for-height, BMI-for-age Z-scores of the National Center for Health Statistics reference standrads). Results: The mean nutritional indices (underweight, stunting and thinness) were found to be much lower among the rural girl than urban girl. The overall prevalent rates of underweight, stunting and thinness were 27.9%, 32.5% and 20.2% respectively. In the rural area these were 35.4%, 35.7% and 26.3%, while in the urban they were 19.6%, 29.0% and 13.6% respectively. Conclusions: The present study shows that undernutrition constituted major health problems among early adolescent school girls in rural areas of India. Hence, the special emphases are needed to formulate various developmental and healthcare programmes for rural communities to prevent undernutrition. Key words: Nutritional status; Early Adolescent girls; Rural; Urban DOI: http://dx.doi.org/10.3126/jnps.v31i3.5352 J Nep Paedtr Soc 2011;31(3):169-174