Maternal serum zinc deficiency in cases of neural tube defect in Gorgan, north Islamic Republic of Iran

Previous studies have shown a high rate of neural tube defects (NTD) in Gorgan, northern Islamic Republic of Iran. This case-control study during 2003-04 compared serum zinc levels and other variables in 23 mothers of neonates affected with NTD and 36 mothers with normal healthy neonates in Dezyani hospital in Gorgan. Mean serum zinc levels in the case and control groups were 13.43 μmol/L (SD 6.3) and 11.41 μmol/L (SD 6.3) respectively. Zinc deficiency was found in 13 (36.5%) of the cases and 7 (19.4%) of the controls. Logistic regression analysis showed an association between the presence of NTD and zinc deficiency (OR 5.06; 95% CI: 1.51-16.94)

Epidemiology of neural tube defects in northern Iran, 1998-2003

We determined the rates of neural tube defects at a referral hospital in Gorgan, north Islamic Republic of Iran, and the relations of these abnormalities to sex, maternal ethnicity, maternal age and season. During 1998-2003, there were 109 cases among 37951 births, a prevalence of 28.7 per 10000 (24.8 and 32.8 per 10000 among males and females respectively). The rates in Turkmen, native Fars and Sistani ethnic groups were 40.5, 25.2 and 30.8 per 10000 respectively. The rates of spina bifida and anencephaly were 16.3 and 11.3 per 10000 respectively. The rate of affected newborns was highest in mothers aged over 35 years (50.7 per 10000). The peak prevalence was in December

Effective mass suppression upon complete spin-polarization in an isotropic two-dimensional electron system

We measure the effective mass (m*) of interacting two-dimensional electrons confined to a 4.5 nm-wide AlAs quantum well. The electrons in this well occupy a single out-of-plane conduction band valley with an isotropic in-plane Fermi contour. When the electrons are partially spin polarized, m* is larger than its band value and increases as the density is reduced. However, as the system is driven to full spin-polarization via the application of a strong parallel magnetic field, m* is suppressed down to values near or even below the band mass. Our results are consistent with the previously reported measurements on wide AlAs quantum wells where the electrons occupy an in-plane valley with an anisotropic Fermi contour and effective mass, and suggest that the effective mass suppression upon complete spin polarization is a genuine property of interacting two-dimensional electrons.Comment: 6 pages, 7 figures, accepted for publication in Phys. Rev.

Dependence of spin susceptibility of a two-dimensional electron system on the valley degree of freedom

We report measurements of the spin susceptibility, $\chi\propto g_v g^*m^*$, in an AlAs two-dimensional electron system where, via the application of in-plane stress, we transfer electrons from one conduction-band valley to another ($g_v$ is the valley degeneracy, and $m^*$ and $g^*$ are the electron effective mass and g-factor). At a given density, when the two valleys are equally populated ($g_v=2$), the measured $g^*m^*$ is smaller than when only one valley is occupied ($g_v=1$). This observation counters the common assumption that a two-valley two-dimensional system is effectively more dilute than a single-valley system because of its smaller Fermi energy.Comment: 4 pages, 3 figure

Discrimination of Entamoeba spp. in children with dysentery

Aim: The present study was performed in order to differentiate E. histolytica and E. dispar in children from Gorgan city, using a PCR method. Background: Differential detection of two morphologically indistinguishable protozoan parasites Entamoeba histolytica and E. dispar has a great clinical and epidemiological importance because of potential invasive pathogenic E. histolytica and non-invasive parasite E. dispar. Patients and methods: One hundred and five dysentery samples were collected from children hospitalized in Taleghani hospital in Gorgan city. The fecal specimens were examined by light microscopy (10X then 40X) to distinguish Entamoeba complex. A single round PCR amplifying partial small-subunit rRNA gene was performed on positive microscopy samples to differentiate E. histolytica/ E. dispar and E. moshkovskii from each other. Results: Twenty-five specimens (23.8%) were positive for Enramoeba complex in direct microscopic examination. PCR using positive controls indicated E. histolytica and E. dispar in two (2/25, 8%) and three (3/25, 12%) samples, respectively. Conclusion: There is a warrant to performing molecular diagnosis for stool examination at least in hospitalized children in order to prevent incorrect reports from laboratories and consequently mistreating by physicians. © 2014 RIGLD, Research Institute for Gastroenterology and Liver Diseases

Group a streptococcal serotypes isolated from healthy schoolchildren in iran

Serotypes of group A streptococci are still a major cause of pharyngitis and some post-infectious sequelae such as rheumatic fever. As part of the worldwide effort to clarify the epidemiological pattern of group A streptococci in different countries, the present study was conducted to assess the prevalence of Streptococcus pyogenes serotypes in Iran. A total of 1588 throat swabs were taken from healthy school children in the city of Gorgan during February and March 1999. Of those isolates, 175 resulted positive for group A streptococci. The distribution pattern was similar for girls and boys, with 10.8 and 11.2, respectively. Urban school children showed a higher rate of colonization compared to those in rural areas. Serotyping was performed on 65 of the positive isolates using standard techniques, and only 21 (32) were M-type isolates. Their profiles fell into four types with M1 predominating, which could reflect the presence of rheumatic fever in the region. However, when isolates were challenged for T-antigen types, nearly all were positive (94). The pattern of T types was diverse (18 types), with the most common T types being T1 (26), TB3264 (15), TB\1-19 & B\25\1-19 (9.2) and T2 & 2\28 (7.7). When isolates were tested for opacity factor, only 23 (35) were positive while 34 (52) responded to the serum opacity reaction test. Although the number of isolates in this study was not sufficient to make any epidemiological conclusions, the scarcity of serotyping studies in Iran could render these data useful for future attempts to develop a streptococcal vaccine