High resolution allele genotyping and haplotype frequencies for NGS based HLA 11 loci of 5266 Hong Kong Chinese bone marrow donors.

Next-generation sequencing (NGS) at the HLA-A, -B, -C, -DRB1, -DRB3/4/5, -DQA1, -DQB1, -DPA1, and -DPB1 loci was performed on 5,266 southern Chinese unrelated donors of the Hong Kong Bone Marrow Donor Registry. High-resolution HLA genotypes defined by full sequencing of class I loci and extended coverage of class II loci were attained to determine allele frequencies and estimate haplotype frequencies. This study provides allele and haplotype frequencies on 11 loci estimated for the first time in the Hong Kong Chinese population. These results describe extended haplotypes including the less frequently typed HLA-DPA1, -DPB1 and -DQA1 loci and distinctive haplotype associations. The present data are timely in that they allow the permissible matching in HLA-DPB1 for Chinese patients awaiting haematopoietic stem cell transplantation upon applying the latest requirement of NMDP matching guidelines. Overall, these results provide a useful reference source for population genetics studies, HLA-disease association studies and for improving donor recruitment and selection strategies of bone marrow registries. The allele and haplotype data are available in the Allele Frequencies Net Database under the population name ''Hong Kong Chinese HKBMDR, HLA 11 loci'' and the identifier (AFND3724) [1].

HLA-DQB1, -DQA1, -DPB1, and -DPA1 genotyping and haplotype frequencies for a Hong Kong Chinese population of 1064 individuals.

HLA-DQB1, -DQA1, -DPB1, and -DPA1 genotyping and haplotype frequencies have been calculated from 1064 southern Chinese unrelated donors in a Hong Kong Bone Marrow Donor Registry. This is the first paper to report the distribution of DQB1-DQA1 and DPB1-DPA1 alleles in Hong Kong Chinese. Due to the Hardy-Weinberg equilibrium proportions (HWEP) deviation in DPB1 loci, this information may be of limited use for phylogenetic, comparative studies but will be useful for the permissible matching in HLA-DPB1 for Chinese patients awaiting haematopoietic stem cell transplantation in the near future due to the new recommendation of NMDP matching guidelines. The allele and haplotype data are available in the Allele Frequencies Net Database under the population name ''Hong Kong Chinese HKBMDR, DQ and DP'' and the identifier (AFND3667).

Origin of abnormal structural transformation in a (BiPb)FeO3/SrRuO3/SrTiO3 hetero-structure probed by Rutherford backscattering.

Scientific efforts are growing to understand artificial BiFeO3/SrRuO3/SrTiO3-heterostructures, wherein an altered environment at each interface, caused by epitaxial strains, broken symmetry, off-stoichiometry and charge transfer, can generate a rich spectrum of exotic properties. Herein, (BiPb)FeO3/SrRuO3/SrTiO3-heterostructures were sputtered with various top (BiPb)FeO3-layers at different growth temperatures (T g). Strain relaxation at each interface changes with T g and generates an additional peak alongside with (BiPb)FeO3 at a high T g of 700 °C. Rutherford backscattering (RBS) was employed to understand this unusual behavior as to whether it is a mixture of two phases, layer splitting or inter-diffusion of elements. Surprisingly, complete overlapping of random and aligned RBS spectra from the sample with T g = 700 °C indicates the presence of a large amount of defects/distortions at the interfaces. The RBS compositional analysis gives clear evidence of Fe and Ru vacancies to an extent that the structural integrity may not be maintained. This abnormal condition can be explained by the inter-diffusion of Pb and Bi elements into whole films and even into the top layer of the SrTiO3 substrate, which compensates for these vacancies by substitutional replacement and is responsible for the generation of the additional SrTi(BiPb)O3-peak. Below T cSrRuO3, the magnetic properties change significantly with T g .

Resveratrol-induced p53-independent apoptosis of human nasopharyngeal carcinoma cells is correlated with the downregulation of ΔNp63.

ΔNp63, the N-terminal truncated isoform of p63, has been found to be overexpressed in several human epithelial cancers, including nasopharyngeal carcinomas (NPCs), suggesting a function in carcinogenesis. Trans-resveratrol (RSV) has been shown to exert proapoptotic activities through a p53-dependent or p53-independent pathway in various cancer cells. However, the effects of RSV on NPC are still unexplored. In this study, we investigated the apoptotic effects of RSV on ΔNp63-overexpressing NPC cell lines. We showed that RSV (12-100 µ) induced dose-dependent growth suppression, cell-cycle arrest in the S phase and caspase-dependent apoptosis in NPC-TW076 and NPC-TW039 cells. The RSV effect was accompanied by the downregulation of ΔNp63 and the upregulation of p53 protein in a dose-dependent manner. By using small-interfering RNA (siRNA) technology, we found that the targeted silencing of ΔNp63 induced apoptosis and sensitized the NPC cells to RSV-induced apoptosis through caspase-3 activation, whereas suppression of p53 by siRNA did not inhibit RSV-induced apoptosis. Furthermore, transfection with p53 siRNA or pretreatment with caspase inhibitors (Z-VAD-fmk or Z-DEVD-fmk) had no influence on the RSV downregulation of ΔNp63. Interestingly, ecoptic expression of ΔNp63 did not significantly block RSV-induced cell death and was also downregulated after RSV treatment. Downregulation of ΔNp63 by RSV was shown to occur at the mRNA transcript and post-translational levels. Importantly, RSV enhanced chemotheraptic drug-induced apoptosis in NPC and two human carcinoma cell lines, HT1376 and Hep3B cells. These results suggested that ΔNp63, but not p53, is a molecular target of RSV-induced apoptosis and the regulation of ΔNp63 expression by RSV may provide a therapeutic effect of RSV in human NPC.

BLM has early and late functions in homologous recombination repair in mouse embryonic stem cells.

BLM is a RecQ family helicase that is defective in individuals with the cancer predisposition disorder, Bloom's syndrome (BS). At the cellular level, BS is characterized by hyper-recombination manifested as excessive sister chromatid exchange and loss of heterozygosity. However, the precise function of BLM remains unclear. Multiple roles have been proposed for BLM in the homologous recombination (HR) repair pathway, including 'early' functions, such as the stimulation of resection of DNA double-strand break ends or displacement of the invading strand of DNA displacement loops, and 'late' roles, such as dissolution of double Holliday junctions. However, most of the evidence for these putative roles comes from in vitro biochemical data. In this study, we report the characterization of mouse embryonic stem cells with disruption of Blm and/or Rad54 genes. We show that Blm has roles both upstream and downstream of the Rad54 protein, a core HR factor. Disruption of Rad54 in the Blm-mutant background reduced the elevated level of gene targeting and of sister chromatid exchanges, implying that Blm primarily functions downstream of Rad54 in the HR pathway. Conversely, however, mutation of Blm in Rad54(-/-) cells rescued their mitomycin C (MMC) sensitivity, and decreased both the level of DNA damage and cell cycle perturbation induced by MMC, suggesting an early role for Blm. Our data are consistent with Blm having at least two roles in HR repair in mammalian cells.

The role of phospholipase D and phosphatidic acid in the mechanical activation of mTOR signaling in skeletal muscle.

Signaling by the mammalian target of rapamycin (mTOR) has been reported to be necessary for mechanical load-induced growth of skeletal muscle. The mechanisms involved in the mechanical activation of mTOR signaling are not known, but several studies indicate that a unique [phosphotidylinositol-3-kinase (PI3K)- and nutrient-independent] mechanism is involved. In this study, we have demonstrated that a regulatory pathway for mTOR signaling that involves phospholipase D (PLD) and the lipid second messenger phosphatidic acid (PA) plays a critical role in the mechanical activation of mTOR signaling. First, an elevation in PA concentration was sufficient for the activation of mTOR signaling. Second, the isozymes of PLD (PLD1 and PLD2) are localized to the z-band in skeletal muscle (a critical site of mechanical force transmission). Third, mechanical stimulation of skeletal muscle with intermittent passive stretch ex vivo induced PLD activation, PA accumulation, and mTOR signaling. Finally, pharmacological inhibition of PLD blocked the mechanically induced increase in PA and the activation of mTOR signaling. Combined, these results indicate that mechanical stimuli activate mTOR signaling through a PLD-dependent increase in PA. Furthermore, we showed that mTOR signaling was partially resistant to rapamycin in muscles subjected to mechanical stimulation. Because rapamycin and PA compete for binding to the FRB domain on mTOR, these results suggest that mechanical stimuli activate mTOR signaling through an enhanced binding of PA to the FRB domain on mTOR.

Accumulation, distribution and transformation of DDT and PCBs by Phragmites australis and Oryza sativa L.: II. Enzyme study.

Two wetland plant species, Phragmites australis and Oryza sativa, were grown in a glasshouse under hydroponics conditions. Enzyme extracts from different parts of the plants were used to determine the transformation rate of o,p'-DDT, p,p'-DDT and PCBs. The organic pollutants were directly spiked into the enzyme extracts, and samples were collected every 30 min and analyzed with a GC-ECD. Root extracts of P. australis readily degraded and transformed DDT and some PCB congeners with a low degree of chlorination. In contrast, crude extracts of O. sativa showed no appreciable degradation or transformation of DDT or PCBs. Inhibition studies indicated that the degradation and transformation of both DDT and PCBs by P. australis enzymes were partly mediated by peroxidase and the plant P-450 system. PCBs with a high degree of chlorination were highly resistant to transformation or degradation by plant enzymes. Both wetland plant species accumulated substantial quantities of the persistent organic chemicals but had different degradation capacities. The enzyme systems in P. australis were much more effective that those in rice in the degradation and transformation of the organic pollutants.

Accumulation, distribution and transformation of DDT and PCBs by Phragmites australis and Oryza sativa L.: I. Whole plant study.

Glasshouse experiments were conducted to determine the accumulation, distribution and transformation of o,p'-DDT, p,p'-DDT and PCBs by common reed (Phragmites australis) and rice (Oryza sativa L.) under hydroponic conditions. The culture solution was spiked with the organic pollutants and samples were collected daily. Analysis of the plants at harvest showed that both species had removed DDT and PCBs from the solution. DDT appeared to have accumulated within P. australis by both passive adsorption and active absorption. Both o,p'-DDT and p,p'-DDT were transformed within P. australis. DDD was the major metabolite and the transformation was mediated by reductive dehalogenation. Plant long-distance transportation systems may be involved in the translocation of PCBs within P. australis and the affinity of the PCBs for lipids is one of the major factors affecting their uptake and translocation within the plants. Similar but less pronounced results were found in O. sativa and suggest that these wetland plants may be used for the plant-mediated remediation of persistent organic pollutants.

Angular-dependent I-V characteristics in borocarbide superconductor YNi(2)B(2)C.

We present angular-dependent current-voltage (I-V) measurements in borocarbide YNi(2)B(2)C single crystals near the vortex-glass irreversible line. External magnetic fields are applied along the angle θ with respect to the c-axis. The nonlinear I-V curves reveal scaling behaviour near the transition. Using the scaling analysis, the relevant critical exponents and vortex transition temperatures are determined for all orientations. The data agrees well with the vortex-glass (VG) model. No evidence was found that supports the existence of a Bose-glass (BG) type of transition.

Inhibition of vascular endothelial cell morphogenesis in cultures by limbal epithelial cells.

PURPOSE: To study the in vitro angiogenic activity of human conjunctival and limbal epithelial cells and conjunctival, limbal, and corneal fibroblasts in a three-cell-type coculture model. METHODS: Human umbilical vein endothelial cells (EC) were cocultured with epithelial cells, fibroblasts, or epithelial cells and fibroblasts to test their effect on EC morphogenesis. Neutralizing antibodies to some known angiogenic factors were added to the culture to see whether the EC morphogenesis may be blocked by a particular antibody. RESULTS: Conjunctival and limbal epithelial cells exhibited very little or no stimulatory effect on EC tube formation when examined in an EC- epithelial cell coculture system. In contrast, conjunctival, limbal, and corneal fibroblasts all promoted EC morphogenesis when examined under the same culture conditions. Fibroblast-induced EC morphogenesis was inhibited by addition of anti-vascular endothelial growth factor (VEGF) and/or anti-basic fibroblast growth factor (bFGF) antibodies to the culture medium. In the three-cell-type coculture system consisting of ECs, fibroblasts, and epithelial cells, limbal epithelial cells (but not conjunctival epithelial cells) exhibited a strong inhibitory effect on fibroblast-induced EC tube formation. CONCLUSIONS: The proangiogenic activity of ocular surface fibroblasts is probably mediated through a paracrine mechanism by VEGF and bFGF. Limbal epithelial cells, but not conjunctival epithelial cells, inhibit fibroblast-stimulated angiogenesis.

A review of digital image networking technologies for radiation oncology treatment planning.

Dosimetrists, physicists, and physicians rely heavily upon digital imaging modalities in their daily work. In the current healthcare marketplace, many radiotherapy facilities operate satellite centers or may be undergoing mergers with other service providers in their community. As a consequence, the development of network-based radiotherapy image communication may yield a significant impact on the clinical operation of such centers. Digital image networking will become an everyday tool in radiotherapy treatment planning in the near future. As responsible users of this technology, an accurate perception of what the network does is essential and enhances our ability to utilize it. This article presents a review of the network architecture and transmission standards necessary for understanding and developing a radiotherapy image network.

An examination of radiation exposure to clinical staff from patients implanted with 137Cs and 192Ir for the treatment of gynecologic malignancies.

The treatment of cancers by placement of radioactive materials within or adjacent to a tumor is clinically known as brachytherapy. Although the intracavitary treatment of gynecologic cancers using 137Cs has been in widespread use for nearly a century, interstitial techniques using 192Ir have developed within the last decade. Both procedures are performed as temporary implants and typically require a hospital stay of approximately 48 h. Significant differences in source strengths, loading conditions, and patient care requirements are visible between the intracavitary and interstitial techniques. Facilities that are experienced in the use of intracavitary techniques may lack clinical experience in the use of newer interstitial procedures. An examination of radiation exposure to the radiation oncology staff administering the treatment, exposure rate at frequently occupied points in the patient room, and exposure to the nursing staff will be of value to those institutions considering integration of interstitial brachytherapy techniques into their department.

An application of digital network technology to medical image management.

With the advent of network technology, there is considerable interest within the medical community to manage the storage and distribution of medical images by digital means. Higher workflow efficiency leading to better patient care is one of the commonly cited outcomes [1,2]. However, due to the size of medical image files and the unique requirements in detail and resolution, medical image management poses special challenges. Storage requirements are usually large, which implies expenses or investment costs make digital networking projects financially out of reach for many clinical institutions. New advances in network technology and telecommunication, in conjunction with the decreasing cost in computer devices, have made digital image management achievable. In our institution, we have recently completed a pilot project to distribute medical images both within the physical confines of the clinical enterprise as well as outside the medical center campus. The design concept and the configuration of a comprehensive digital image network is described in this report.

An analysis of the elements essential in the development of a customized TBI program.

Bone marrow transplant, once a procedure carried out at a relatively small number of large medical centers, is being employed at an increasing number of non-academic hospitals. The use of total body photon irradiation for the purpose of marrow ablation and immunosuppression can be expected to accompany the outward growth of bone marrow transplantation at these same hospitals. An analysis of the fundamental physical factors associated with total body photon irradiation (TBI) should be of value to facilities considering the incorporation of a total body irradiation program into an existing radiation oncology department. By examining the existing resources of a radiotherapy center and the clinical objectives of the treatment, a facility considering TBI may determine whether or not their center already fulfills the necessary criteria, in addition to the avoidance of potential pitfalls in project implementation.

Proton spectroscopy of brain glutamine in acute liver failure.

Evidence indicates that the accumulation of glutamine in the brain plays an important role in the pathogenesis and severity of the encephalopathy of acute liver failure (ALF). This study uses in vivo proton magnetic resonance spectroscopy (1H MRS) to assess brain glutamine (GLN) in five cases of acute liver failure. The findings are consistent with prior investigations and suggest that the alpha 1H of the GLN molecule can be used for noninvasive spectroscopic quantitation of brain GLN in patients with ALF.

Prospective utility of cerebral proton magnetic resonance spectroscopy in monitoring HIV infection and its associated neurological impairment.

Neurological manifestations of HIV disease occur in most adults and children with AIDS. Many of those affected will inevitably suffer clinical neurological deficits involving mental function, movement, and sensation. Surprisingly, there are not as yet adequate monitoring systems to predict the onset and/or progression of HIV infection of the CNS. Neurological, neuropsychological, CSF, and magnetic resonance imaging (MRI) analyses cannot accurately detect mental deterioration during advancing HIV disease. Reports suggest that in vivo proton MR spectroscopy (1H MRS) of the brain could be a predictor of virus-induced neurological deterioration. H MRS can measure N-acetylaspartate (NAA), a metabolite present only in neurons. Decreased NAA reflects neuronal loss seen during HIV infection of brain. To uncover possible associations between NAA levels and HIV-induced neurological disease we performed serial 1H MRS brain tests in HIV-infected patients with or at risk for encephalopathy. Serial testing, for 1 year, of 10 patients showed that brain NAA levels decreased in all HIV-infected subjects. The most severe NAA reductions were associated with progressive neurological impairment. These findings suggest that NAA can be used as a noninvasive measure of neuronal loss in patients with HIV disease. Most important, the results suggest that 1H MRS could be used to monitor therapeutics directed against HIV infection within the CNS.

Role of brachytherapy in the management of the skull base meningioma. Treatment of skull base meningiomas.

BACKGROUND: The treatment of primary and recurrent skull base meningiomas presents a formidable surgical problem. METHODS: Fifteen patients with primary and recurrent skull base meningiomas were treated by means of interstitial irradiation with iodine 125 (125I) seed implantation. The physical characteristics of 125I enabled the authors to administer a minimum tumor dose ranging from 100 to 500 Gy at a low dose rate of 0.05-0.25 Gy per hour. RESULTS: All 15 patients are alive at a median follow-up of 29 months. Of the 15 patients, 2 with calcification and 2 without calcification achieved only partial responses. The remaining 11 patients achieved a complete response. No early or late complications were observed. CONCLUSIONS: From these data, the authors conclude that interstitial irradiation with 125I seeds is an effective, safe, and simple method in the treatment of both recurrent and primary skull base meningiomas.

Continuous low dose rate brachytherapy with high activity iodine-125 seeds in the management of meningiomas.

The purpose of this study was to evaluate if meningiomas can be effectively treated with brachytherapy using permanent implantation of high activity I-125 seeds. Thirteen patients with intracranial meningiomas were treated by means of permanent stereotactic implantation of one or more high-activity I-125 seeds. The physical characteristics of I-125 enabled us to deliver a minimum tumor dose ranging from 100 Gy to 500 Gy at a low dose rate of 5 cGy to 25 cGy per hr. Indications for this procedure included recurrence after initial surgery or as primary modality of treatment in patients who were not candidates for surgery. All 13 patients are alive at a median follow-up of 25 months. Nine of 13 patients achieved complete resolution of the tumor and in the remaining four, more than 50% reduction in tumor volume was noted at the last follow-up. No late complications were observed. We conclude from this initial data that localized high dose irradiation delivered at a low dose rate using I-125 permanent implantation is an effective, safe, and simple method in the treatment of both recurrent and primary intracranial meningiomas.

Hypertrophic response to unilateral concentric isokinetic resistance training.

The purposes of this study were to 1) determine the effect of concentric isokinetic training on strength and cross-sectional area (CSA) of selected extensor and flexor muscles of the forearm and leg, 2) examine the potential for preferential hypertrophy of individual muscles within a muscle group, 3) identify the location (proximal, middle, or distal level) of hypertrophy within an individual muscle, and 4) determine the effect of unilateral concentric isokinetic training on strength and hypertrophy of the contralateral limbs. Thirteen untrained male college students [mean age 25.1 +/- 6.1 (SD) yr] volunteered to perform six sets of 10 repetitions of extension and flexion of the nondominant limbs three times per week for 8 wk, using a Cybex II isokinetic dynamometer. Pretraining and posttraining peak torque and muscle CSA measurements for both the dominant and nondominant limbs were determined utilizing a Cybex II isokinetic dynamometer and magnetic resonance imaging scanner, respectively. The results indicated significant (P less than 0.0008) hypertrophy in all trained muscle groups as well as preferential hypertrophy of individual muscles and at specific levels. None of the muscles of the contralateral limbs increased significantly in CSA. In addition, significant (P less than 0.0008) increases in peak torque occurred for trained forearm extension and flexion as well as trained leg flexion. There were no significant increases in peak torque, however, for trained leg extension or for any movement in the contralateral limbs. These data suggest that concentric isokinetic training results in significant strength and hypertrophic responses in the trained limbs.

Estimation of the mean effective organ doses for total body irradiation from Rando phantom measurements.

For the total body irradiation (TBI) procedure, it is necessary to compare the mean dose obtained from the tissue or organs and the estimated dose equivalent value from the computer program. Due to the easy-access of the Rando phantom and repeatability of TLDs and its output, the results from the experiment are quite encouraging for the verification of the dose distributions from total body irradiation at the given prescribed monitor units. The estimation of effective dose equivalent particularly across the lung sections was studied by combinations of using arms as the scatter volume to compensate for the inhomogeneity across the breast portion, as well as using the spoiler for skin-sparing purposes. The results were based upon various beam quality such as 4 MV, 6 MV, and 10 MV X rays. One series of experiments performed for this survey to ascertain the dose equivalent of the tissues was conducted. This paper describes the method and procedure for comparison between the measured data and computed data as a reference in the dosimetry of total body irradiation. Comparison of the measured and computed data for the largest collimated field shows that the calculated dose rates do not differ by more than 2% from the measured data. Because uncertainty is inherent in non-patient-like phantoms, the calculated data may be served as a reference for the dosimetry. For the total body irradiation setup, considering the radiation field size and treatment distances commonly employed, we conclude that the best combination of the patient setup will be (1) laying both arms down as compensation for lung inhomogeneity, and (2) the spoiler, which is made of acrylic about 8 mm thick and functions like a bolus, is needed to reduce the skin sparing effects and contribute the uniform dose distribution. The beam spoiler with the frame stands near the patient during the treatment.