Activation of particulate guanylyl cyclase by Vibrio vulnificus hemolysin

Recently we reported that Vibrio vulnificus hemolysin, an exotoxin produced by V. vulnificus, dilates rat thoracic aorta via elevated cGMP levels without affecting nitric oxide synthase. We investigated the mechanism further by observing the guanylyl cyclase activities in cytosolic, membrane, unfractionated, or reconstituted preparations. Hemolysin did not activate guanylyl cyclase in the membrane or cytosolic fraction, while it activated guanylyl cyclase in unfractionated or reconstituted preparation. The increased activity was not inhibited by the HS-142-1, a microbial polysaccharide which antagonizes atrial natriuretic peptide receptor, or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a soluble guanylyl cyclase inhibitor. However, it was attenuated by 6-(phenylamino)-5,8-quinolinedione (LY 83.583), which inhibits the catalytic domain of both guanylyl cyclases, and by cholesterol, which blocks hemolysin-incorporation into the membrane. Removing ATP, a cofactor of particulate guanylyl cyclase, attenuated the activation and ATPgammaS, a non-phosphorylating analog, restored it. These results suggest that V. vulnificus hemolysin activates particulate guanylyl cyclase via hemolysin incorporation into the vascular smooth muscle cell membrane in cooperation with certain unidentified cytosolic component(s).     

Recorded audio prompts. A strategy to increase independent prevocational task completion in individuals with dual diagnosis

This research was conducted to teach two adults with schizophrenia and mental retardation to respond to recorded audio prompts in order to eliminate the need for instructor assistance in completing routine prevocational tasks. Studying individuals with dual diagnosis is an important step in moving toward success in community living and vocational placement. A multiple probe design across tasks was conducted. Prior to the investigation, both individuals demonstrated low levels of independent task completion. Following the implementation of the audio prompts, both individuals' task completion performances dramatically increased. These findings suggest that audio prompts may serve as an efficient alternative to instructor promoting, which is often required by individuals with dual diagnosis in prevocational job settings.     

Expression of the HGF/SF receptor, c-met, and its ligand in human colorectal cancers

To characterize the clinical features of childhood tuberculosis, we analyzed the symptoms, signs, and laboratory findings of the 89 children with tuberculosis admitted to the Yokohama City University Hospital from 1975 to 1994. Compared with the numbers of patients admitted from 1975 to 1979, those of patients of the past 5 years (from 1990 to 1994) were reduced by half. Of the 89 subjects, 56.2% were below 3 years of age and 24.7% were under 1 year of age. 51.7% had primary complex and 20.2% had serious tuberculosis (tuberculous meningitis 14.6%, miliary tuberculosis 3.4%, and bone and joint tuberculosis 2.2%). Tuberculous children below 3 years of age consisted of primary complex (60.0%) and serious tuberculosis (32.0%). The majority (86.0%) of tuberculous children below 3 years of age had not received BCG vaccination. In 55 (61.8%) of 89 subjects, the sources of tuberculosis were clarified. Of these subjects, 83.6% were infected in the family. The rate of BCG inocluation tended to decrease with decreasing age, especially that of children below 3 years of age was 14.0%. Of the 89 subjects, only 16.9% proved to be smear-positive. Taken together, in order to eliminate tuberculous children below 3 years of age, the following is necessary; (1) BCG inoculation in early infancy, (2) early diagnosis of index cases with adult tuberculosis, and (3) prompt and appropriate family contact examination.     

Common patterns of genetic evolution in human solid tumors

Microscopy is a basic tool for cell biologists. Recent progress of electronics and computer science made powerful methodologies for digital processing of microscopic images easily available. These methods allowed impressive increase of the power of conventional microscopy. Dramatic image enhancement may be achieved by combination of filtering techniques, computer-based deblurring and contrast enhancement. Quantitative treatment of digitized images allows absolute determination of the density of different components of the observed sample, including antigens, intracellular calcium and pH. Morphometric studies are also greatly facilitated by image processing techniques. The capture of fast phenomena may be performed by transfer of small portion of microscopic images into computer memory as well as particular use of confocal microscopy. Finally, improved display of experimental data through coded colors or other procedures may enhance the amount of information that can be conveyed by visual examination of microscopical images. The purpose of the present review is to describe the basic principles of image processing and exemplify the power of this approach with a variety of illustrated applications to conventional, fluorescence or electron microscopy as well as confocal microscopy.     

Chronic oral etoposide and tamoxifen in the treatment of far-advanced hepatocellular carcinoma

BACKGROUND: Hepatocellular carcinoma (HCC) is a chemoresistant tumor that frequently expresses a high level of p 170 glycoprotein of the multidrug-resistance (MDR) gene. Preliminary data suggested that VP-16 showed modest activity in HCC. Recently, schedule-dependent cytotoxicity of VP-16 has been demonstrated. In this study, we tested the therapeutic efficacy of chronic oral VP-16 plus tamoxifen, a potential MDR-reversing agent, in patients with far-advanced HCC. METHODS: A prospective single-arm study was conducted in the National Taiwan University Hospital. To be eligible, patients must have had unresectable and non-embolizable HCC, objectively measurable tumors, adequate hemogram with absolute granulocyte count greater than or equal to 2,000/mm3, and platelet count greater than or equal to 1x10 (5)/mm3, total serum bilirubin less than or equal to 3.0 mg/dl, age less than or equal to 75 years, and a Karnofsky performance status of greater then or equal to 50%. The treatment included VP-16 (Bristol-Myers-Squibb, Princeton, NJ), 50 mg/m2/day, orally, Days 1 to 21, and tamoxifen (Pharmachemie B.V. Haarlem, Netherlands), 40 mg/day, orally, Days 1 to 21; repeated every 5 weeks. RESULTS: Between December 1990 and December 1993, a total of 33 patients were enrolled in the study. There were 28 men and 5 women, with a median age of 51 years. They received an average of 3.2 (range: 1-10) courses of chemotherapy. ECOG (Eastern Cooperative Oncology Group) Grade 3 and Grade 4 leucopenia developed in 6 patients (18.2%) and 4 (12.1%) patients, respectively. Grade 3 and 4 thrombocytopenia developed in 2 patients (6.1%). Treatment-related death occurred in one patient due to sepsis. Mild gastrointestinal toxicities were common with Grade 1 and 2 nausea. Grade 1 and 2 vomiting, Grade 1 and 2 diarrhea, and Grade 1 and 2 stomatitis, developed in 13 (39.4%), 7 (21.2%), 12 (36.4%), and 16 (48.5%) patients, respectively. Grade 3 and 4 gastrointestinal toxicities were rare. Deep vein thrombosis occurred in one patient (3.0%). Eight patients (24.2%, 95% confidence interval 11%-42%) had achieved a partial remission, with a median time-to-progression of 6 months (2-11). Median survivals of the responders and non-responders were 8.0 and 3.0 months, respectively (P < 0.05). The median Karnofsky performance status of the responders improved from 70% to 80%. CONCLUSIONS: Chronic oral VP-16 and tamoxifen has modest activity and acceptable toxicity in far-advanced HCC, and is a useful palliative treatment in about a quarter of such patients.     

HLA-DRB1 genes and disease severity in rheumatoid arthritis. The MIRA Trial Group. Minocycline in Rheumatoid Arthritis

OBJECTIVE: To examine the effect of alleles encoding the "shared"/"rheumatoid" epitope on rheumatoid arthritis (RA) disease severity in patients who participated in the minocycline in RA (MIRA) trial. METHODS: Of 205 patients with a week-48 visit, blood was available for typing of HLA-DRB1 and HLA-DQB1 in 174 (85%) and successfully completed in 169 (82%). Baseline erosions were used to assess disease severity and new erosions at the last visit served as a proxy for progression. RESULTS: At baseline, there was no association between the presence of erosive disease or rheumatoid factor status and the dose of rheumatoid epitope (homozygous, heterozygous, none) or the specific alleles identified. At the final visit, a gradient was observed for the 3 allelic subgroups (and their gene doses) in the occurrence of new erosions among the Caucasian placebo-treated, but not the minocycline-treated, patients. A treatment group/HLA-DR4 epitope interaction was demonstrated in multivariate analyses. Approximately two-thirds of African-American patients did not have the rheumatoid epitope. CONCLUSION: HLA-DRB1 oligotyping may be useful in predicting the progression of disease in some Caucasian patients. Our study corroborates the infrequency of the epitope among African-American patients with RA.