The "2 + 1" mechanism as the basis for synergism in the neutron-photon irradiation of the spermatozoal genome in Drosophila melanogaster

Cytogenetic analysis of polytene chromosomes of Drosophila melanogaster locus-specific mutants induced by consecutive neutron-photon irradiation has shown that their genome contains multiple intra- and inter-chromosome exchanges, including triradials, evidencing the synergistic action of such combined exposure. The appearance of the triradials may be only possible on the base of an interaction between a double and a single DNA strand breaks. The important significance of such interaction as the general mechanism for production of chromosome aberrations in irradiated cells of higher eucaryotes had been postulated by N. V. Luchnik as early as 10 years ago, but only nowadays it has been confirmed experimentally.     

HIV, but not murine leukemia virus, vectors mediate high efficiency gene transfer into freshly isolated G0/G1 human hematopoietic stem cells

Recent studies have opened the possibility that quiescent, G0/G1 hematopoietic stem cells (HSC) can be gene transduced; lentiviruses (such as HIV type 1, HIV) encode proteins that permit transport of the viral genome into the nucleus of nondividing cells. We and others have recently demonstrated efficient transduction by using an HIV-1-based vector gene delivery system into various human cell types including human CD34(+) cells or terminally differentiated neurons. Here we compare the transduction efficiency of two vectors, HIV-based and murine leukemia virus (MuLV)-based vectors, on untreated and highly purified human HSC subsets that are virtually all in G0/G1. The HIV vector, but not MuLV vector supernatants, transduced freshly isolated G0/G1 HSC from mobilized peripheral blood. Single-step transduction using replication-defective HIV resulted in HSC that expressed the green fluorescent protein (GFP) transgene while retaining their stem cell phenotype; clonal outgrowths of these GFP+ HSC on bone marrow stromal cells fully retained GFP expression for at least 5 weeks. MuLV-based vectors did not transduce resting HSC, as measured by transgene expression, but did so readily when the HSC were actively cycling after culture in vitro for 3 days in a cytokine cocktail. These results suggest that resting HSC may be transduced by lentiviral-based, but not MuLV, vectors and maintain their primitive phenotype, pluripotentiality, and at least in vitro, transgene expression.     

Viral hepatitis delta in the republic of Belarus

26,740 blood donors and persons of high risk groups with respect to HBV infection, residing in different regions of Belarus, were examined for the presence of HBsAg in 1983-1997. Of these, 1372 persons (5.1%) were found to have HBsAg, and out of 1081 HBsAg-positive persons anti-HDV antibodies (Ab) were detected in 96 persons (8.9%). In spite of a decrease in acute virus hepatitis B morbidity and in HBsAg carriership, the occurrence of anti-HBV Ab remained stable during the period of 16 years and was equal, on the average, about 4% among asymptomatic HBsAg carriers. Patients having tuberculosis, rheumatoid arthritis, diabetes mellitus, hematological diseases, chronic hepatitides and cirrhosis of the liver were an important reservoir of HBV and HDV infections for regions with the low level of the spread of HBV. A decrease in the detection rate of anti-HDV Ab in patients with cirrhosis of the liver from 47.6% to 15.4% was noted. In 1991-1997 a decrease in the detection rate of anti-HDV Ab in patients with chronic hepatic lesions in comparison with 1983-1990 was observed, and in the age group older than 50 years this decrease was from 33.3% to 8.3%. This difference was particularly pronounces in patients with cirrhosis of the liver: 53.9% and 7.7% respectively.     

Compliance issues with the geriatric population: complexity with aging

Nonadherence with the prescribed treatment regimen is a major issue in health care. This article focuses specifically on adherence issues in the geriatric population. The strengths and weaknesses of measurement methods to assess nonadherence with medication regimens are discussed. Determinants of noncompliance with special emphasis on risk factors for geriatric patients are described. Finally, an overview of preventative and restorative compliance interventions is given.     

Initial characterization of a protochordate histocompatibility locus

The colonial protochordate, Botryllus schlosseri, undergoes a natural transplantation reaction which is controlled by a single, highly polymorphic locus called the Fu/HC. We are using map-based cloning to identify Fu/HC gene(s), and have currently delineated their location to an approximately 1-cM region of the B. schlosseri genome. The Fu/HC physical map currently consists of 85 sequence-tagged sites mapped on a minimum tiling path of 800 kb which consists of five contigs, with four gaps remaining to be crossed, and is estimated to be 75% completed. Approximately half this region has been sequenced throughout the locus, allowing the first analysis of a metazoan histocompatibility locus outside of vertebrates. This has resulted in the identification of 18 predicted genes, a number of which have been found to be expressed. Several of these genes are well conserved among the chordates; however, none of the predicted or expressed genes are linked within the genome of any organism in the databases. In addition, the Fu/HC is one of the most polymorphic loci ever described, and physical mapping has revealed that the locus is quite dynamic, and includes features such as hotspots of recombination.     

Surface‐Mountable 10 Gbps Photoreceiver Module Using Inductive Compensation Method

We propose an inductive compensation method for a surface‐mountable 10 Gbps photoreceiver module. Since many typical 10 Gbps photoreceiver modules consist of a photodetector and low‐noise pre‐amplifier, the impedance mismatch between the photodetector and preamplifier, as well as package parasitics, may reduce the frequency bandwidth. In this paper, we inserted an inductive component between the photodetector and pre‐amplifier in order to create frequency bandwidth expansion. From the measurement results, we have found that the proposed technique can increase the ?3 dB bandwidth about 4.2 GHz wider compared with an uncompensated module. And, from a bit‐error rate (BER) test, we observed ?15.7 dB sensitivity at 10^?12 BER. This inductive compensation can be implemented easily and is compatible with common manufacturing processes of photoreceiver modules.     

Ultrafast Discharge/Charge Rate and Robust Cycle Life for High‐Performance Energy Storage Using Ultrafine Nanocrystals on the Binder‐Free Porous Graphene Foam

A hierarchical architecture fabricated by integrating ultrafine titanium dioxide (TiO₂) nanocrystals with the binder‐free macroporous graphene (PG) network foam for high‐performance energy storage is demonstrated, where mesoporous open channels connected to the PG facilitate rapid ionic transfer during the Li‐ion insertion/extraction process. Moreover, the binder‐free conductive PG network in direct contact with a current collector provides ultrafast electronic transfer. This structure leads to unprecedented cycle stability, with the capacity preserved with nearly 100% Coulombic efficiency over 10 000 Li‐ion insertion/extraction cycles. Moreover, it is proven to be very stable while cycling 10 to 100‐fold longer compared to typical electrode structures for batteries. This facilitates ultrafast charge/discharge rate capability even at a high current rate giving a very short charge/discharge time of 40 s. Density functional theory calculations also clarify that Li ions migrate into the TiO₂–PG interface then stabilizing its binder‐free interface and that the Li ion diffusion occurs via a concerted mechanism, thus resulting in the ultrafast discharge/charge rate capability of the Li ions into ultrafine nanocrystals.     

Hyperinsulinemia and clustering of cardiovascular risk factors in middle-aged hypertensive Finnish men and women

OBJECTIVE: To examine the relationship between hyperinsulinemia and clusters of cardiovascular risk factors in middle-aged hypertensive patients. DESIGN: A population-based study. SETTING: Pieks?m?ki District Health Center, and the Community health Center of the city of Tampere, in central Finland. SUBJECTS: Hypertensive men and women aged 36, 41, 46, and 51 years (n = 18) in the town of Pieks?m?ki, and a normotensive control population of 177 subjects aged 40 and 45 years in the city of Tampere. MAIN OUTCOME MEASURES: Clusters of obesity (body mass index > 30.0 kg/m2), abdominal adiposity (waist:hip ratio > 1.00 for men and > 0.88 for women), hypertriglyceridemia (> 1.70 mmol/l), a low level of high-density lipoprotein cholesterol (< 1.0 mmol/l in men and < 1.20 mmol/l in women) and abnormal glucose metabolism (impaired glucose tolerance or noninsulin-dependent diabetes as defined by World Health Organization criteria) according to statistical quartiles of the fasting plasma insulin concentration. RESULTS: Among the hypertensives, there was a 2.0- to 3.6-fold higher risk of having a clustering of the insulin-resistance associated cardiovascular risk factors compared with that of the normotensives. Among the hypertensive subjects in the highest quartile of fasting plasma insulin there was a six- to 12-fold increase in risk associated with having two or more insulin resistance-associated cardiovascular risk factors compared with the subjects in the lowest quartile. There was a positive correlation between a high number of ascertained risk factors and high levels of fasting plasma insulin. CONCLUSION: In clinical practice, knowledge of the close relationship between risk-factor cluster status and fasting plasma insulin levels offers a tool to evaluate the occurrence of hyperinsulinemia in middle-aged hypertensive men and women.