Infectious transmission of human T-cell leukemia virus to rabbits

A rabbit lymphoid cell line (Ra-1) was established by co-cultivation with a human T-cell line (MT-2) carrying human T-cell leukemia virus (HTLV). The Ra-1 cell line is chromosomally male and is persistently infected with HTLV. Ra-1 cells, with or without mitomycin C treatment, were inoculated intravenously (i.v.) into 3 female rabbits. All 3 animals responded with the production of antibodies to HTLV antigens. Lymphocytes from one of these seroconverters were cultured in the presence of T-cell growth factor (TCGF) and HTLV particles were detected in the TCGF-grown lymphocytes which were chromosomally female. Co-cultivation of lymphocytes from the 2 other seroconverters with lymphocytes from 2 anti-HTLV-negative healthy men gave rise to the establishment of an HTLV-producing T-cell line derived from each individual. Blood transfusion from one of the HTLV-infected rabbits into 2 female rabbits also resulted in the seroconversion of both recipients. An HTLV-carrying lymphoid cell line (Ra-2) was established from one of the transfusion-related seroconverters. The Ra-2 cell line was initially TCGF-dependent but later became TCGF-independent. There results indicate that HTLV can be transmitted to rabbits. These animals may provide a suitable model system for studying the mode of transmission and pathogenicity of HTLV.     

Adjusted relative survival rate and causes of death after resection of gastric cancer

To estimate how many of 1,302 patients with curative resection of gastric cancer died of recurrence or other diseases, the cumulative survival rate (act), relative survival rate (rl) and adjusted relative survival rate (adj) were analyzed. Adj was computed excluding gastric cancer death, because the death rate of this disease can not be ignored in the Japanese population. The death rate from gastric cancer can be estimated by [1.0-(adj)] and that from other causes by [(adj)-(act)]. It is more appropriate to calculate adj for the patients with mucosal or submucosal cancer, and rl can be substituted for adj for those with deeper invasion.     

Fabrication of porous particulate for the scaffold by applying solution spraying method

A simple and novel method--in the form of solution spraying--was developed to fabricate biodegradable, porous poly(L-lactic acid) (PLLA) particulates for scaffold. PLLA pellets were dissolved in an organic solvent. Then, 5 % PLLA-dioxane solution was sprayed using an air-assisted atomizer with a nozzle diameter of 2.5 mm at an air flow rate of 15 L/min. After the sprayed solution solidified in liquid nitrogen, spherical particulates with median diameter of 225microm were obtained. Morphology of sprayed products could be altered by varying the fabrication conditions. When nozzle diameter was reduced to 1.5 mm, sprayed products became fibrous. When the concentration of PLLA-dioxane solution was increased, the diameter of particulates increased too. On the other hand, when air flow rate was increased, the diameter of particulates decreased. Likewise, solidification conditions also affected the morphology of sprayed products, such that they were either thin film-like or in particulate form. Based on the results of the present study, we concluded that PLLA particulates of varying morphologies could be obtained by adjusting the fabrication conditions.     

Downregulation of laminin alpha4 chain expression inhibits glioma invasion in vitro and in vivo

The laminin family is a structural constituent of the extracellular matrix that plays an essential role in promoting the motility of infiltrative tumor cells. We investigated the role of laminin alpha4 chain, a subset of laminin-8, -9 and -14, in the motile and invasive activities of human glioma cells. All malignant glioma cell lines examined expressed more mRNA for the laminin alpha4 and beta1 chains than for the beta2 chain, indicating that these cells predominantly express the laminin-8 isoform. Introducing an antisense oligonucleotide for laminin alpha4 chain (AS-Ln-alpha4) into the glioma cells resulted in downregulation of laminin alpha4 expression. AS-Ln-alpha4 also significantly suppressed glioma cell adhesion and migration. Furthermore, invasiveness was significantly reduced in cells transfected with AS-Ln-alpha4 compared to those transfected with the sense oligonucleotide (S-Ln-alpha4). Indeed, when glioma spheroids were implanted into rat brain slices, AS-Ln-alpha4-transfected cells failed to invade surrounding normal brain tissues. In addition, intracerebral injection of glioma cells transfected with AS-Ln-alpha4 into nude mice resulted in the formation of a noninvasive tumor, whereas injection of cells transfected with S-Ln-alpha4 resulted in diffuse invasion of brain tissue. These results suggest that mainly laminin-8 is essential for the invasive activity of human glioma cells; thus, a novel therapeutic strategy could target this molecule to treat patients with malignant glioma.     

Neuronally expressed Ras-family GTPase Di-Ras modulates synaptic activity in Caenorhabditis elegans

Ras‐family GTPases regulate a wide variety of cellular functions including cell growth and differentiation. Di‐Ras, which belongs to a distinct subfamily of Ras‐family GTPases, is expressed predominantly in brain, but the role of Di‐Ras in nervous systems remains totally unknown. Here, we report that the Caenorhabditis elegans Di‐Ras homologue drn‐1 is expressed specifically in neuronal cells and involved in synaptic function at neuromuscular junctions. Loss of function of drn‐1 conferred resistance to the acetylcholinesterase inhibitor aldicarb and partially suppressed the aldicarb‐hypersensitive phenotypes of heterotrimeric G‐protein mutants, in which acetylcholine release is up‐regulated. drn‐1 mutants displayed no apparent defects in the axonal distribution of the membrane‐bound second messenger diacylglycerol (DAG), which is a key stimulator of acetylcholine release. Finally, we have identified EPAC‐1, a C. elegans Epac homologue, as a binding partner for DRN‐1. Deletion mutants of epac‐1 displayed an aldicarb‐resistant phenotype as drn‐1 mutants. Genetic analysis of drn‐1 and epac‐1 showed that they acted in the same pathway to control acetylcholine release. Furthermore, DRN‐1 and EPAC‐1 were co‐immunoprecipitated. These findings suggest that DRN‐1 may function cooperatively with EPAC‐1 to modulate synaptic activity in C. elegans.     

Liquid-based urine cytology as a tool for detection of human papillomavirus, Mycoplasma spp., and Ureaplasma spp. in men

Liquid-based urine cytology (LB-URC) was evaluated for cytological diagnosis and detection of human papillomavirus (HPV), Mycoplasma, and Ureaplasma. Midstream urine samples were collected from 141 male patients with urethritis and 154 controls without urethritis, and sediment cells were preserved in liquid-based cytology solution. Urethral swabs from urethritis patients were tested for the presence of Neisseria gonorrhoeae and Chlamydia trachomatis. Papanicolaou tests were performed for cytological evaluation. HPV, Mycoplasma, and Ureaplasma genomes were determined by PCR-based methods, and localization of HPV DNA in urothelial cells was examined by in situ hybridization (ISH). The β-globin gene was positive in 97.9% of LB-URC samples from urethritis patients and in 97.4% of control samples, suggesting that high-quality cellular DNA was obtained from the LB-URC samples. HPV DNA was detected in 29 (21.0%) urethritis cases and in five (3.3%) controls (P < 0.05). HPV type 16 (HPV 16) was most commonly found in urethritis patients. Cytological evaluations could be performed for 92.1% of urethritis patients and 64.3% of controls. Morphological changes suggestive of HPV infection were seen in 20.7% of the HPV-positive samples, and ISH demonstrated the presence of HPV DNA in both squamous and urothelial cells in HPV-positive samples. Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum were detected in 14.5%, 10.9%, 6.5%, and 12.3% of urethritis patients, respectively. The prevalence rates of these microorganisms (except Ureaplasma parvum) were significantly higher in urethritis cases than controls (P < 0.05). LB-URC is applicable for detection of HPV, Mycoplasma, and Ureaplasma. HPV infection occurs in urothelial cells, especially in gonococcal urethritis.     

Recent advances in diagnostic approaches for sub-arachnoid hemorrhage

Sub-arachnoid hemorrhage (SAH) has been easily one of the most debilitating neurosurgical entities as far as stroke related case mortality and morbidity rates are concerned. To date, it has case fatality rates ranging from 32-67%. Advances in the diagnostic accuracy of the available imaging methods have contributed significantly in reducing morbidity associated with this deadly disease. We currently have computed tomography angiography (CTA), magnetic resonance angiography (MRA) and the digital subtraction angiography (DSA) including three dimensional DSA as the mainstay diagnostic techniques. The non-invasive angiography in the form of CTA and MRA has evolved in the last decade as rapid, easily available, and economical means of diagnosing the cause of SAH. The role of three dimensional computed tomography angiography (3D-CTA) in management of aneurysms has been fairly acknowledged in the past. There have been numerous articles in the literature regarding its potential threat to the conventional "gold standard" DSA. The most recent addition has been the introduction of the fourth dimension to the established 3D-CT angiography (4D-CTA). At many centers, DSA is still treated as the first choice of investigation. Although, CT angiography still has some limitations, it can provide an unmatched multi-directional view of the aneurysmal morphology and its surroundings including relations with the skull base and blood vessels. We study the recent advances in the diagnostic approaches to SAH with special emphasis on 3D-CTA and 4D-CTA as the upcoming technologies.