Rotavirus survival on human hands and transfer of infectious virus to animate and nonporous inanimate surfaces.

We tested the survival of the Wa strain of human rotavirus on the hands of volunteers and also studied infectious virus transfer between animate and inanimate (stainless steel disks) surfaces. The virus was diluted in a 10% suspension of feces, and 10 microliters (1 X 10(3) to 4 X 10(4) PFU) was placed on each of the four fingerpads of the left hand. One milliliter of 20% tryptose phosphate broth in Earle balanced salt solution was used for virus elution from each fingerpad, and the hands were disinfected with 70% ethanol before they were washed with an antiseptic soap and water. At 20, 60, and 260 min after inoculation, approximately 57, 43, and 7%, respectively, of the input infectious virus could be recovered. For virus transfer, the inoculum (2 X 10(4) to 8 X 10(4) PFU) was allowed to dry, and the donor surface was kept in contact with the recipient surface for 10 s at a pressure of approximately 1 kg/cm2. At 20 and 60 min after virus inoculation, 16.1 and 1.8%, respectively, of the input infectious virus could be transferred from the contaminated hand to a clean disk; when a clean hand was pressed against a contaminated disk, virus transfer was 16.8 and 1.6%, respectively. Contact between a contaminated and a clean hand 20 and 60 min after virus inoculation resulted in the transfer of 6.6 and 2.8%, respectively, of the input infectious virus. These findings indicate the potential vehicular role for human hands in the spread of rotaviral infections.     

Depression and social stress in Pakistan

BACKGROUND: The high prevalence of depression in developing countries is not well understood. This study aimed to replicate the previous finding of a high prevalence of depression in Pakistan and assess in detail the associated social difficulties. METHOD: A two-phase survey of a general population sample in a Pakistani village was performed. The first-phase screen used the Personal Health Questionnaire (PHQ) and the self-rating questionnaire (SRQ). A one in two sample of high scorers and a one in three sample of the low scorers were interviewed using the Psychiatric Assessment Schedule (PAS) and Life Events and Difficulties Schedule (LEDS). RESULTS: A total of 259 people were screened (96% response rate). The second stage yielded 55 cases, of whom 54 had depressive disorder, and 48 non-cases. The adjusted prevalence of depressive disorders was 44-4% (95% CI 35.3 to 53.6): 25.5% in males and 57.5% in females. Nearly all cases had lasted longer than 1 year. Comparison of the cases and non-cases indicated that cases were less well educated, had more children and experienced more marked, independent chronic difficulties. Multivariate analysis indicated that severe financial and housing difficulties, large number of children and low educational level were particularly closely associated with depression. CONCLUSION: This study confirms the high prevalence of depressive disorders in Pakistan and suggests that this may be higher than other developing countries because of the high proportion of the population who experience social adversity.     

Concentrations of serum total protein and protein fractions during diestrus and pregnancy in Makuii ewes

The aim of this study was to determine the blood protein changes during different stages of pregnancy and to compare with prepregnancy diestrus in ewes. A total of 90 blood samples were taken from ten Makuii ewes (the native sheep breed in Iran) at diestrus and on days 8, 14, 28, 45, 60, 90, 125, and 145 of pregnancy. Serum protein electrophoresis of samples exhibited four fractions: albumin, α, β, and γ fractions in Makuii ewes, which in α- and γ-globulin bands were divided to α1 and α2; and γ1 and γ2, respectively. The mean concentrations (in gram per deciliter) of total serum proteins, albumin, α1-, α2-, β-, γ1-, and γ2-globulin at diestrus period were 7.03, 3.77, 0.18, 0.74, 0.41, 1.56, and 0.41, respectively. Those values fluctuated nonsignificantly throughout gestation until the 125th day of pregnancy. Thereafter, a significant decrease (p < 0.01) in serum protein levels occurred at the 145th day of pregnancy compared to prepregnancy and other gestational time points. It was concluded that blood protein levels declined sharply during late gestation when the nutrient demands of the fetus were maximal.     

The development of mouse APECED models provides new insight into the role of AIRE in immune regulation

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy is a rare recessive autoimmune disorder caused by a defect in a single gene called AIRE (autoimmune regulator). Characteristics of this disease include a variable combination of autoimmune endocrine tissue destruction, mucocutaneous candidiasis and ectodermal dystrophies. The development of Aire-knockout mice has provided an invaluable model for the study of this disease. The aim of this review is to briefly highlight the strides made in APECED research using these transgenic murine models, with a focus on known roles of Aire in autoimmunity. The findings thus far are compelling and prompt additional areas of study which are discussed.     

Association of class II DNA restriction fragments with responsiveness to Ambrosia artemisiifolia (short ragweed)-pollen allergen Amb a V in ragweed-allergic patients

Human IgE and IgG antibody responsiveness to the short ragweed-pollen allergen Amb a V (formerly known as Ra5) has been found to be strongly associated with HLA-D specificities Dw2 and DR2 in ragweed-allergic white individuals. To study the molecular basis of these associations, restriction fragment length polymorphism (RFLP) mapping was performed on a group of 45 white ragweed-allergic patients with full-length HLA-DR beta, DQ beta, and DQ alpha cDNA probes. The data on 41 of these subjects were used for the purposes of statistical analysis. With the DR beta probe, we found that the presence of three polymorphic restriction fragments correlated with responsiveness to Amb a V and with the DR2 specificity, namely, a 6.5 kb Eco RI fragment, a 9.4 kb Hind III fragment, and a 2.2 kb Hind III fragment. The presence of four fragments detected with the DQ beta probe correlated with responsiveness to Amb a V and with Dw2 specificity: a 2.3 kb Eco RI fragment, a 13.0 kb Pst I fragment, a 2.9 kb Taq I fragment, and a 5.2 kb Eco RV fragment. The DR beta Eco RI 6.5 kb and the DQ beta Eco RI 2.3 kb fragments were studied in detail; the concordant presence of these fragments was even more strongly associated with responsiveness to Amb a V. Fifteen of 17 responders had both fragments, whereas only one of 24 nonresponders had both fragments (p = 5 x 10(-7). This is the first time that such an association has been found between a person's immune response to a well-defined antigen and a set of HLA class II DNA restriction fragments.     

A novel frame shift mutation in the HMG box of the SRY gene in a patient with complete 46,XY pure gonadal dysgenesis.

Pure gonadal dysgenesis or Swyer syndrome is a sex-reversal disorder resulting from embryonic testicular regression sequences especially during the first few weeks of fetal life and is induced by mutations in the SRY gene. In the present report, we describe a nonmosaic XY sex-reversed female with pure gonadal dysgenesis. Molecular analysis using sequential PCR to detect Y chromosomal microdeletions showed the presence of SRY, ZFY and AZFa, b and c regions. Automated sequencing of the SRY region revealed a new mutation (deletion of A (adenine) in codon 82 at position +244), leading to a frame shift mutation within the helix I of the HMG-box domain. This mutation generates a truncated protein and is very likely to produce an impairment of SRY DNA binding activity. The present findings further support the functional importance of the putative DNA binding activity of the SRY HMG-box domain.     

Using a photon phase-space source for convolution/superposition dose calculations in radiation therapy

For a given linac design, the dosimetric characteristics of a photon beam are determined uniquely by the energy and radial distributions of the electron beam striking the x-ray target. However, in the usual commissioning of a beam from measured data, a large number of variables can be independently tuned, making it difficult to derive a unique and self-consistent beam model. For example, the measured dosimetric penumbra in water may be attributed in various proportions to the lateral secondary electron range, the focal spot size and the transmission through the tips of a non-divergent collimator; the head-scatter component in the tails of the transverse profiles may not be easy to resolve from phantom scatter and head leakage; and the head-scatter tails corresponding to a certain extra-focal source model may not agree self-consistently with in-air output factors measured on the central axis. To reduce the number of adjustable variables in beam modelling, we replace the focal and extra-focal sources with a single phase-space plane scored just above the highest adjustable collimator in a EGS/BEAM simulation of the linac. The phase-space plane is then used as photon source in a stochastic convolution/superposition dose engine. A photon sampled from the uncollimated phase-space plane is first propagated through an arbitrary collimator arrangement and then interacted in the simulation phantom. Energy deposition kernel rays are then randomly issued from the interaction points and dose is deposited along these rays. The electrons in the phase-space file are used to account for electron contamination. 6 MV and 18 MV photon beams from an Elekta SL linac are used as representative examples. Except for small corrections for monitor backscatter and collimator forward scatter for large field sizes (<0.5% with <20 x 20 cm2 field size), we found that the use of a single phase-space photon source provides accurate and self-consistent results for both relative and absolute dose calculations.     

Toxicokinetics and molecular interaction of [14C]-formaldehyde in rats

The excretion, tissue distribution, and binding of [¹⁴C]-formaldehyde were studied at different time intervals in male rats following a single intraperitoneal injection of 72 mg CH₂O (14.7 Ci)/ kg body weight. Within 30 min, 10% of the total dose was recovered in expired air as¹⁴CO₂ and by the end of 72 hr, 41% of the administered dose was eliminated through expired air. The total elimination of¹⁴CH₂O activity in urine and feces in 72 hr was 15%. Erythrocytes retained significant amounts of radioactivity, even at the end of 72 hr. Substantial levels of radioactivity were detected in most tissues one hr after administration, indicating a fast absorption and rapid distribution. Subcellular fractionation of the tissues showed that the highest levels of relative percent binding was in the microsomal fraction, whereas cytosol fractions contained lowest levels of bound radioactivity. DNA, RNA, protein and lipid fractions of liver and spleen tissues showed significantly elevated levels of¹⁴C-incorporation as compared to other tissues. Thein vivo incorporation of¹⁴C-activity showed an increased association of¹⁴CH₂O with RNA in all the tissues. The maximum registration of radioactivity in RNA was at 48 hr after administration. Significantly higher amounts of¹⁴C-activity were registered in DNA of all tissues. The maximum registration of radiolabel in DNA of most tissues was at 12 hr after the¹⁴CH₂O administration. The liver DNA showed maximal levels at 3 hr with a second peak at 48 hr.Substantial amounts of bound radioactivity in nucleic acids of all the tissues were observed even 72 hr after dosing. The relationship between macromolecular association and formaldehyde toxicity has been discussed.