Ipsilesional neglect: behavioural and anatomical features

OBJECTIVE

To learn more about the behavioural and anatomical features of ipsilesional neglect.

METHODS

Thirty consecutive patients with spatial neglect were tested on cancellation and line bisection tasks. To learn if patients with ipsilesional neglect demonstrate the sensory-attentional or motor-intentional type of neglect, a video apparatus was used that dissociates these determinants.

RESULTS

Five patients showed evidence of ipsilesional neglect. This phenomenon was seen only on the line bisection task. All patients with ipsilesional neglect had lesions involving frontal-subcortical regions. Although ipsilesional neglect evolved from early in three of five cases, the other patients displayed ipsilesional neglect without initial contralateral neglect, suggesting that ipsilesional neglect cannot be fully attributed to a compensatory strategy. The results of the tests that used the video apparatus indicate that right sided frontal or subcortical injury may induce contralateral attentional or intentional "approach" behaviours.

CONCLUSIONS

Ipsilesional neglect is most often associated with frontal-subcortical lesions, cannot be entirely attributed to a compensatory strategy, and may be induced by an attentional bias, an intentional bias, or both.

Antitumor agents. 194. Synthesis and biological evaluations of 4-beta-mono-, -di-, and -trisubstituted aniline-4'-O-demethyl-podophyllotoxin and related compounds with improved pharmacological profiles

As a continuation of our structure-activity relationship studies, several new 4-beta-substituted 4'-O-demethyl-4-desoxypodophyllotoxins bearing mono-, di-, or trisubstituted anilines have been synthesized and evaluated as inhibitors of DNA topoisomerase II and tumor cell growth in tissue culture. Selected compounds were further evaluated as cytotoxic agents using a clonogenic survival assay. The target compounds include 4'-O-demethyl-4beta-[(4' '-(benzimidazol-2' '-yl)anilino]-4-desoxypodophyllotoxin (21), 4'-O-demethyl-4beta-(-)-(4' '-camphanamido-anilino)-4-desoxypodophyllotoxin (25), 4-beta-disubstituted-anilino-4'-demethyl-4-desoxypodophyllotoxins (18-20, 26), 4-alpha-disubstituted-anilino-4'-demethyl-4-desoxypodophyllotoxin (27), 4-beta-trisubstituted-anilino-4'-demethyl-desoxypodophyllotoxin (22, 23), and 4'-O-demethyl-4beta-[4' '-(benzimidazol-2' '-yl)amino]-4-desoxypodophyllotoxin (24). Among the target series, 19, 21, and 24 displayed significant growth inhibitory action against a panel of tumor cell lines including human epidermoid carcinoma of the nasopharynx (KB) and its etoposide-resistant (KB7B) and vincristine-resistant (vin20c KB) subclones, lung carcinoma (A549), human ileocecal carcinoma (HCT-8), human kidney carcinoma (CAKI-1), breast adenocarcinoma (MCF-7), and human malignant melanoma (SK-MEL-2) cells. Compounds 19, 21, 24, and 25 were "cleavable-complex"-forming DNA topoisomerase II inhibitors with either improved or similar activity compared with the prototype drug etoposide (VP-16). Compound 21 was the most active analogue, being 10-fold more potent than etoposide in both cell killing and topoisomerase II inhibition in vitro assays. Using mouse models of antitumor activity, 21 was effective against (P388/0) leukemia but not against the growth of a (MCF7) mammary tumor.

In vitro antifungal activity and cytotoxicity of a novel membrane-active peptide

In the present study, we investigated the antifungal activity and cytotoxicity of a novel membrane-active peptide, KKVVFKVKFKK (MP). MP inhibited the growth of various pathogenic fungi isolated from patients and of fluconazole-resistant fungi at concentrations of 2 to 32 microg/ml. MP had potent fungicidal activity; the minimal fungicidal concentrations of the peptide were no more than fourfold greater than the MICs. Time course experiments of MP-induced killing of Candida albicans ATCC 36232 showed that the rate of killing was rapid and depended on the concentration of MP. MP had a strong synergism with other antifungal drugs; the fractional inhibitory concentration index values of MP with amphotericin B and fluconazole for C. albicans were 0.16 and 0.02, respectively. The 50% inhibitory concentrations of MP for NIH 3T3 and Jurkat cells were approximately 100 times higher than the MIC for C. albicans ATCC 36232, indicating that MP had high selectivity between the fungal and mammalian cells. These results suggest that MP has great advantages in the development of antifungal agents.

Biodegradable nanoparticles containing doxorubicin-PLGA conjugate for sustained release

PURPOSE

Doxorubicin was chemically conjugated to a terminal end group of poly(D,L-lactic-co-glycolic acid) [PLGA] and the doxorubicin-PLGA conjugate was formulated into nanoparticles to sustain the release of doxorubicin.

METHODS

A hydroxyl terminal group of PLGA was activated by p-nitrophenyl chloroformate and reacted with a primary amine group of doxorubicin for conjugation. The conjugates were fabricated into ca. 300 nm size nanoparticles by a spontaneous emulsion-solvent diffusion method. The amount of released doxorubicin and its PLGA oligomer conjugates was quantitated as a function of time. The cytotoxicity of the released species was determined using a HepG2 cell line.

RESULTS

Loading efficiency and loading percentage of doxorubicin-PLGA conjugate within the nanoparticles were 96.6% and 3.45 (w/w) %, respectively while those for unconjugated doxorubicin were 6.7% and 0.26 (w/w) %, respectively. Both formulation parameters increased dramatically due to the hydrophobically modified doxorubicin by the conjugation of PLGA. The nanoparticles consisting of the conjugate exhibited sustained release over 25 days, whereas those containing unconjugated free doxorubicin showed rapid doxorubicin release in 5 days. A mixture of doxorubicin and its PLGA oligomer conjugates released from the nanoparticles had comparable IC50 value in a HepG2 cell line compared to that of free doxorubicin. Sustained drug release was attributed to the chemical degradation of conjugated PLGA backbone, which permitted water solubilization and subsequent release of doxorubicin conjugated PLGA oligomers into the medium.

CONCLUSIONS

The conjugation approach of doxorubicin to PLGA was potentially useful for nanoparticle formulations that require high drug loading and sustained release. The doxorubicin-PLGA oligomer conjugate released in the medium demonstrated a slightly lower cytotoxic activity than free doxorubicin in a HepG2 cell line.

Assessment of body composition using dual energy x-ray absorptiometry in patients with liver cirrhosis: comparison with anthropometry

OBJECTIVES

The aim of this study was to evaluate changes of body composition in cirrhotic patients. Dual energy x-ray absorptiometry (DEXA) and anthropometry were used, and the values obtained were compared.

METHODS

Mid-arm fat and muscle areas were calculated by anthropometry in 66 cirrhotic patients and 94 healthy controls. In 37 of the cirrhotic patients and 39 of the controls, fat mass, lean soft tissue mass and bone mineral contents were measured with DEXA.

RESULTS

The number of cirrhotic patients with measured values below the fifth percentile of normal controls was 21 (31.8%) by mid-arm fat area, six (9.1%) by mid-arm muscle area, 15 (40.5%) by fat mass and 0 (0%) by lean soft tissue mass. The fat mass in cirrhotic patients was less than in controls, whereas lean soft tissue mass and bone mineral content were not different. Fat depletion was severe in Child-class C patients and with severe ascites. Mid-arm fat area and fat mass showed close correlation (r = 0.85, p < 0.01), but mid-arm muscle area and lean soft tissue mass showed poor correlation (r = 0.32, p < 0.05).

CONCLUSION

Cirrhotic patients showed lower fat component, with preserved lean soft tissue mass and bone mineral content. In clinical practice, the measurement of mid-arm fat area was useful for the assessment of fat mass.

Effect of eradication of Helicobacter pylori on the benign gastric ulcer recurrence--a 24 month follow-up study

OBJECTIVES

To evaluate the effect of eradication of Helicobacter pylori (H. pylori) on the recurrence of benign gastric ulcer (BGU) in the patients with BGU.

METHODS

This study was performed for 40 H. pylori-positive BGU patients cured of BGU and H. pylori eradicated, and for 25 H. pylori-positive patients (non-eradicated group) who were not treated with H. pylori eradication regimen or H. pylori was not eradicated. Four different methods--CLOtest, microscopy of Gram stained mucosal smear, culture and histology of modified Giemsa staining--were taken for identifying colonization of H. pylori before treatment, and 4 weeks after completion of triple therapy. For the control group in which triple therapy was not tried, follow-up gastroscopy was done to confirm the healing of the ulcer. To detect BGU recurrence, the gastroscopy was performed at 6, 12, 18, and 24 months after therapy.

RESULTS

In the non-eradicated group, the BGU recurrence rate was 16% within 6 months, 40% within 1 year, 56% within 18 months and 60% within 2 years. The respective recurrence rates in the 40 patients in whom the bacteria had been eradicated were 0%, 7.5%, 10% and 10% (4 patients), respectively. Among the four BGU-recurred patients in whom H. pylori had been eradicated, one patient was found to have BGU recurring with H. pylori positive again in one year, and another two patients had NSAIDs ingestion history.

CONCLUSION

The eradication of H. pylori in patients with BGU reduces the recurrence of BGU. In addition, the major causes of BGU recurrence look like NSAIDs ingestion and reinfection of H. pylori.

The cytoplasmic domain of HIV-1 gp41 interacts with the carboxyl-terminal region of alpha-catenin

To know the cellular protein interactions with the viral protein can give an insight into the molecular mechanisms of the virus life cycle. As the function of the cytoplasmic domain of human immunodeficiency virus type 1 (HIV-1) gp41 is not known clearly, we searched for a cellular protein that interacts with the cytoplasmic domain of the HIV-1 gp41 using the yeast two-hybrid assay system. Screening of HeLa cell cDNA library yielded alpha-catenin cDNA. The cytoplasmic domain of the HIV-1 gp41 and the simian immunodeficiency virus (SIV) gp41 were able to interact with the carboxyl-terminal region of alpha-catenin specifically. Mapping of the interaction sites revealed that the interaction between the domain containing the second helix structure from the carboxyl-terminus of HIV-1 gp41 and the carboxyl-terminal region of alpha-catenin was stronger than other domains of gp41.

A novel cytolysis assay using fluorescent labeling and quantitative fluorescent scanning technology

A novel cellular cytotoxicity assay using Calcein acetoxymethyl (Calcein-AM), a cytoplasmic fluorescent label, has been developed as an alternative to the standard 51Chromium (Cr)-release. Target cells were loaded with Calcein-AM and then co-incubated with effector cells. An additional reagent, FluoroQuench, is added to extinguish fluorescence of dying target cells and of the culture media. Assay plates are read on a quantitative fluorescent scanner for determination of viable target cells. Percent lysis is calculated as one minus the percent viable cells as compared to fluorescent-labeled targets-only wells. The assay was tested to demonstrate the lytic activity of cytotoxic T lymphocyte (CTL) cultures, lymphokine-activated killer (LAK), and natural killer (NK) cell line effectors against peptide-pulsed and melanoma targets. In addition to the acquisition of results comparable to the 51Cr-release assay, the Calcein assay reliably measures cell-mediated cytotoxicity with little variance among replicates. The fluorescent assay represents a simple and useful alternative to the use of radioactive materials and adds the additional benefit of digital images and analysis.

Effects of antioxidants and gamma irradiation on the shelf life of beef patties

To improve the storage safety of two types of ground beef patty popular in Korea (general beef patties and bulgogi patties), we added various antioxidants (200 ppm; including butylated hydroxyanisole, ascorbyl palmitate, alpha-tocopherol, and beta-carotene) to typical formulations of patties, cooked the patties to 70 degrees C, and irradiated them at a dose of 1.5 or 3 kGy. During 30 d of storage at 5 degrees C, the number of aerobic bacteria and lactic acid bacteria were determined using total aerobic plate count and phenyl ethyl alcohol-sucrose agar, respectively. The concentration of thiobarbituric acid was also determined in each type of patty. No colonies were observed in patties irradiated at 3 kGy regardless of which antioxidant was added. In control patties and patties with butylated hydroxyanisole that were irradiated at a dose of 1.5 kGy, growth of microorganisms appeared to be more rapid than in patties with natural antioxidants. The microbiological safety of nonirradiated patties could not be ensured for a period of 20 d. Lipid oxidation was retarded in both types of patty when an antioxidant was added. Ascorbyl palmitate had the strongest antioxidant effect among the natural antioxidants. However, butylated hydroxyanisole was more effective than ascorbyl palmitate when used in an equal amount.

Treatment of delayed partial bronchial rupture with expandable metallic stent

Traumatic bronchial rupture is a rare entity. The severity of the trauma often causes lethal injury to other thoracic organs. The incidence in patients with blunt chest trauma admitted to the hospital ranges from 1.5% to 3%. As a rule, early diagnosis and surgical treatment are important to facilitate successful repair of the disruption. We describe an unusual case of bronchial rupture which was diagnosed 15 days after blunt chest trauma and was treated by bronchial stenting. The success of this case involving the left main bronchial rupture provides a feasible alternative to the repair of partial airway disruption and greatly reduces the morbidity.

Synthesis and cytotoxicity of methyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione derivatives

2- and 3-Methyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione and related derivatives were synthesized and evaluated in vitro by NCI against eight cancer types. Compounds 12-15 showed significant activity against melanoma, NCI-H23 non-small cell lung cancer, and MDA-MB-435 and MDA-N breast cancer cell lines; 2-hydroxymethyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dion e (13) showed the highest activity against melanoma (mean log GI50 = -7.74) and the highest overall potency (mean log GI50 = -6.99).

Neuregulin stimulates myogenic differentiation in an autocrine manner

During myogenesis, mononucleated myoblasts form multinucleated myotubes by membrane fusion. Efficiency of this intercellular process can be maximized by a simultaneous progress, with a time window, of other neighboring myoblasts in the differentiation program. This phenomenon has been described as the community effect. It proposes the existence of a molecule that acts as a differentiation-inducing signal to a group of identical cells. Here, we show that neuregulin is a strong candidate for this molecule in myoblast differentiation. The expression of neuregulin increased rapidly but transiently at early stage of differentiation of rat L6 cells. Neuregulin showed a potent differentiation-promoting activity in membrane fusion and expression of myosin heavy chain. The antibodies raised against neuregulin and its cognate receptor ErbB3, which were capable of neutralizing the signal pathway, inhibited myotube formation and expression of myosin heavy chain in both L6 cells and primary rat myoblasts. The progress of differentiation was mostly halted after the expression of myogenin and cell cycle arrest. These results suggest that the activation of an autocrine signaling of neuregulin may provide a basic mechanism for the community effect observed in the differentiation of the embryonic muscle cells.

Short dysfunctional telomeres impair tumorigenesis in the INK4a(delta2/3) cancer-prone mouse

Maintenance of telomere length is predicted to be essential for bypass of senescence and crisis checkpoints in cancer cells. The impact of telomere dysfunction on tumorigenesis was assessed in successive generations of mice doubly null for the telomerase RNA (mTR) and the INK4a tumor suppressor genes. Significant reductions in tumor formation in vivo and oncogenic potential in vitro were observed in late generations of telomerase deficiency, coincident with severe telomere shortening and associated dysfunction. Reintroduction of mTR into cells significantly restored the oncogenic potential, indicating telomerase activation is a cooperating event in the malignant transformation of cells containing critically short telomeres. The results described here demonstrate that loss of telomere function in a cancer-prone mouse model possessing intact DNA damage responses impairs, but does not prevent, tumor formation.

Motor perseverative behavior on a line cancellation task

OBJECTIVES

To study the behavioral and neuroanatomic characteristics of perseverative behavior encountered on a target cancellation task in patients with neglect.

METHODS

Motor perseverative behavior during line cancellation task was evaluated retrospectively in 60 patients with left hemispatial neglect from right hemispheric stroke.

RESULTS

More than 30% of the patients (21 of 60) showed perseveration, manifested as either repetitive cancellation of the same target (18/21) or cancelling extra lines created by the patients themselves (3/21). Neglect severity correlated positively with the frequency of perseverative errors. Perseveration was most prominent in the rightmost portion of the array. Anterior lesions or massive lesions involving anterior and posterior regions were more likely to be associated with motor perseveration than were lesions restricted to posterior areas.

CONCLUSIONS

Although the mechanism of motor perseveration remains to be elucidated, our findings suggest that the combination of aberrant approach behaviors associated with frontal lobe injury and an attentional or intentional bias toward the rightsided targets might explain the behavior.

Enhancement of DNA damage and involvement of reactive oxygen species after exposure to bitumen with UVA irradiation

This study was carried out to evaluate whether bitumen cytotoxicity is enhanced when bitumen treatment is combined with UVA exposure. We also evaluated the oxidative processes in bitumen-induced DNA damage, and attempted to identify the DNA damage caused by bitumen and UVA exposures, either alone or in combination. The effects of bitumen and UVA on cell proliferation were examined using HL 60 cells. DNA-protein crosslinks (DPCs) were assessed using a K-SDS assay, and reactive oxygen species formation was detected by 8-OH-dG formation. We evaluated the formations of double-strand breaks (DSB) using lambdaDNA/HindIII and single-strand breaks (SSB) using PM2 DNA. The cytotoxicity assay showed enhanced suppression of cell proliferation when bitumen exposure and UVA exposure were combined. Combined exposure caused significant increases in DPCs over either exposure alone. Incubation of deoxyguanosine (dG) with bitumen or UVA showed an increase in 8-hydroxy-2'-deoxyguanosine (8-OH-dG) levels when compared with controls, and combined exposure enhanced this effect. An evaluation of agarose gel bands showed that DSB and SSB were not formed following exposure to bitumen and UVA. This fact indicates that bitumen and UVA may be involved in genotoxic processes by producing oxygen free radicals and that combined exposure enhances these effects.

Hospitalised low-risk community-acquired pneumonia: outcome and potential for cost-savings

Fine et al. from USA have identified a sub-group of patients with community-acquired pneumonia (CAP) with a low risk of mortality and suggested that it may be cost-effective to manage them as outpatients. The aims of this study were: to evaluate the outcome of low risk CAP patients that were hospitalised in our local setting, and to gauge the number of such patients in order to estimate the potential cost-savings by treating them as outpatients, as well as the safety of such an approach. All patients with CAP admitted to our hospital from 1 April 1997 to 1 March 1998 were enrolled into this prospective cohort study. Low-risk patients were identified, and their hospital outcome compared with other patients. Hospitalisation charges were obtained from the Finance Department. There were 226 patients with CAP. The average age was 64 years with a range of 12 to 96 years. The median hospital stay was 6 days. Mortality was 13.7%. 16.8% required admission to the ICU; none of these were low-risk patients. There were 47 (21%) low-risk patients, and there was no mortality in this group. They had significantly shorter hospital stay (6.4 days versus 10 days) and lower hospitalisation charges ($2,160 versus $5,770) compared to other CAP patients. Only one low-risk patient had a positive blood culture. In conclusion, nearly one-fifth of our CAP admissions consisted of low-risk patients that experienced no mortality, and required a significantly shorter hospitalisation. The management of such patients who are young (< or = 50 years), with no serious co-morbidities in an outpatient setting may be a cost-effective strategy, and this group of patients consumed 9% of the total hospitalisation charges for CAP.

High-resolution HLA-A*0201 subtyping using directed heteroduplex analysis

HLA-A02* has become an important target for cytotoxic T lymphocyte-based immunotherapy reflecting the high prevalence of this allele in patient populations. There are at least 26 different A*02 alleles, and their subtype specificity has significant functional implications for T-cell-mediated recognition of immunologic targets. We have developed a novel method for HLA-A*02 allelic screening using directed heteroduplex analysis (DHDA). DNA samples from Epstein-Barr virus (EBV)-transformed B lymphoblastoid cell lines (EBV-B) representing 10 different HLA-A*02 alleles (0201, 0202, 0204, 0205, 0206, 0208, 0210, 0211, 0216, 0217) were prepared. In addition, DNA was prepared from 81 individuals representing a wide variety of A*02 subtypes previously determined by sequence specific primer (SSP) polymerase chain reaction (PCR) including individuals heterozygous for two A*02 specificities. Probes and samples were generated by PCR amplification using HLA-A*02 specific primers encompassing exons 2 and 3, where most of the functionally significant allelic polymorphism is clustered. DHDA was performed by generating heteroduplex molecules composed of a fluorescein-labeled allelic probe sequence and an unlabeled allelic PCR product. Gel retardation was consistent for allele-probe combinations. We were able to identify several A*02 alleles prepared from EBV-B cell lines that, when used as probes, had very impressive specificity and sensitivity. Combinations of two probes were identified (0205 + 0211 and 0208 + 0211) that allowed differentiation of A*0201 alleles from all other A*02 alleles tested. All samples typed by probe combinations had DHDA typing and SSP typing confirmed by DNA sequencing. This study expands the molecular typing repertoire available to the modern HLA laboratory, and shows that DHDA has significant promise as a reliable screening method for HLA A*02 subtyping.

Comparisons of prognostic scoring systems for myelodysplastic syndromes: a Korean multicenter study

We have conducted a multicenter collaborative retrospective analysis to evaluate clinical characteristics and to compare prognostic scoring systems of 149 Korean patients with myelodysplastic syndromes (MDS). The median age of the patients was 53 years (range 17-82 years) with high of the patients being younger than 40 years. Median survival was 22.6 months, and 25 patients (17%) progressed to acute myelogenous leukemia (AML) with a median interval of 6 months (range 1-45 months). Major independent variables assessed by multivariate analysis were FAB subtypes and bone marrow (BM) blast percentages for survival and BM blast percentages for AML transformation. To compare the various scoring systems in the prediction for survival and transformation to AML, FAB, Sanz and Bournemouth scoring systems were applied to all patients, while the international prognostic scoring system (IPSS), Lille and Toyama scoring systems were applied to 91 patients. The Sanz scoring system (P < 0.0001), FAB classification (P < 0.0001), IPSS (P < 0.001), and Toyama scoring system (P < 0.005) were highly predictive for survival showed greater discrimination than that of the other systems. For AML transformation, the IPSS (P < 0.0001), Toyama scoring system (P < 0.0001), FAB classification (P < 0.0001), and Lille scoring system (P < 0.005) successfully discriminated risk groups. Although the prognostic factors and the distribution of age were different from those in Western reports, the IPSS and Toyama scoring system were applicable for predicting survival and leukemic transformation in Korean patients with MDS.

A sensitive fluorescence in situ hybridization technique for detection of porcine reproductive and respiratory syndrome virus

A sensitive fluorescence in situ hybridization (ISH) for detecting porcine reproductive and respiratory syndrome virus (PRRSV) RNA in viral infected tissue was developed using digoxigenin-labeled RNA probes targeted on the nucleocapsid gene of PRRSV. In situ RNA/RNA hybrids were detected with an anti-digoxigenin antibody alkaline phosphatase conjugate and further revealed with Fast Red TR salt/naphthol AS-MX phosphate using a fluorescent microscope. Viral nucleic acid was readily demonstrated within macrophages, known to be the major target of PRRSV. In addition, positively stained cells were found in the salivary gland and skin tissues which have not been reported to contain PRRSV infected cells before. In conclusion, the fluorescence ISH used in this study provides a fast and sensitive means for screening virus-infected tissues in which relatively few cells are affected. This advantage will be especially beneficial for studying viral persistence and for routine diagnosis of PRRSV infection.

Proteomics: theoretical and experimental considerations

Cellular engineering relies on the ability to decipher the genetic basis of various phenotypes. Emerging technologies for analyzing the biological function of the information encoded in the genome of particular organisms and/or tissues focus on the monitoring of transcription (mRNA) and translation (protein) processes. Elementary theoretical considerations presented in this article strongly suggest that a combination of mRNA and protein expression patterns should be simultaneously considered to fully develop a conceptual understanding of the functional architecture of genomes and gene networks. We propose a framework of experimental and mathematical methods for acquiring and analyzing quantitative proteomic information and discuss recent developments in proteome analytical technology.

Acute and chronic phase platelet aggregability studies in Chinese patients after implantation of a permanent transvenous pacemaker

It has been suggested that the incidence of thromboembolic events always increases in patients after insertion of a transvenous pacemaker. Blood samples from twenty consecutive patients (fifteen males and five females) before and after pacemaker implantation was retained for platelet aggregability studies which were analyzed separately with ADP, collagen, epinephrine and arachidonic acid. The maximal amplitude of platelet aggregatory curve was detected by an aggregometer. The samples collected the day before pacemaker implantation (day 0) were used as self-control. Day 1 and day 3 after pacemaker implantation were defined as the acute phase, while day 30 was defined as the chronic phase. The maximal amplitude of platelet aggregatory curve was observed to be lowest on day 1 and then return to normal on day 3 and day 30. The results of platelet aggregability, however, showed no significant difference (P>0.05) between self-control and post-implantation samples. In conclusion, there was no significant change in platelet aggregability for either acute or chronic phases after pacemaker implantation. Antiplatelet medications may not be necessary for the prevention of thromboembolic events after the implantation of a pacemaker.

Oxamflatin is a novel antitumor compound that inhibits mammalian histone deacetylase

Oxamflatin [(2E)-5-[3-[(phenylsufonyl) aminol phenyl]-pent-2-en-4-ynohydroxamic acid] induces transcriptional activation of junD and morphological reversion in various NIH3T3-derived transformed cell lines. We found that oxamflatin showed in vitro antiproliferative activity against various mouse and human tumor cell lines with drastic changes in the cell morphology and in vivo antitumor activity against B16 melanoma. Oxamflatin caused an elongated cell shape with filamentous protrusions as well as arrest of the cell cycle at the G1 phase in HeLa cells. These phenotypic changes of HeLa cells were apparently similar to those by trichostatin A (TSA), a specific inhibitor of histone deacetylase (HDAC). The effect of oxamflatin on the transcriptional activity of the cytomegalovirus (CMV) promoter was examined and compared with known HDAC inhibitors, TSA, sodium n-butyrate, and FR901228. Oxamflatin as well as all these inhibitors greatly enhanced the transcriptional activity of the CMV promoter in a dose-dependent manner. Oxamflatin, like TSA, inhibited intracellular HDAC activity, as a result of which marked amounts of acetylated histone species accumulated. Finally, effects on expression of several endogenous genes involved in cell morphology and cell cycle control in HeLa cells were analysed. Expression of gelsolin, cyclin E and Cdk inhibitors including p21WAF1/Cip1 was highly augmented, while that of cyclin A and cyclin D1 was decreased by oxamflatin. These results suggest that changes in the expression pattern of the genes regulating cell morphology and the cell cycle due to histone hyperacetylation are responsible for the antitumor activity, the morphological change and the cell cycle arrest induced by oxamflatin.

Behçet's disease sera containing antiendothelial cell antibodies promote adhesion of T lymphocytes to cultured human dermal microvascular endothelial cells

Antiendothelial cell antibodies (AECA) have been detected in the sera of patients of autoimmune diseases showing vasculitis. Using IgM-ELISA, we found AECA in 42 (56%) of 75 sera samples from patients with Behçet's disease in a previous study. All of the 15 AECA-positive sera of Behçet's disease patients had an increased expression of the intercellular cell adhesion molecule-1 (ICAM-1), 93.3% of the sera induced the vascular cell adhesion molecule-1 (VCAM-1), and 100% of the serum induced the E-selectin molecule on human dermal microvascular endothelial cells (HDMEC). After stimulation of HDMEC with AECA-positive sera of Behçet's disease patients, the expression of ICAM-1 and VCAM-1 on HDMEC increased significantly at 4 hours, reaching a peak at 16 hours. Expression of E-selectin was induced at 1 hour after stimulation with a peak at 4 hours and it decreased thereafter. Adherence of T lymphocytes to HDMEC increased significantly after stimulation with AECA-positive sera from Behçet's disease patients. Also, the adherence of T lymphocytes to HDMEC increased at 4 hours and returned to its normal level at 48 hours. These results show that AECA-positive sera of Behçet's disease patients are capable of activating HDMEC to promote the adherence of T lymphocytes to increase the expression of ICAM-1, VCAM-1, and E-selectin on the cell surfaces. The whole process may play an important role in the pathogenesis of vasculitis in Behçet's disease.

Phenotyping of flavin-containing monooxygenase using caffeine metabolism and genotyping of FMO3 gene in a Korean population

Flavin-containing monooxygenase (FMO) activity was determined in 82 Korean volunteers by taking molar concentration ratio of theobromine and caffeine present in the 1 h urine (between 4 and 5 h) samples collected after administration of a cup of coffee containing 110 mg of caffeine. Among 82 volunteers, there were 19 women and 63 men (30 smokers and 52 non-smokers). Volunteers were divided into two groups comprising low (0.53-2.99) and high (3.18-11.95) FMO activities separated by an antimode of 3.18. Peripheral bloods were sampled from these volunteers and their genomic DNAs were amplified by polymerase chain reaction with oligonucleotides designed from intronic sequences of human FMO3 gene. Comparing nucleotide sequences of the amplified FMO3 gene originating from randomly selected individuals with low and high FMO activities, nine point mutations were identified in the open reading frame sequences. Among these nine mutations, three FMO3 mutant types (FMO3/Stop148, Lys158 and Gly308) were selected and correlated with FMO activities observed in our Korean population. A rare FMO3/Stop148 mutant allele originating from FMO3/Gly148 occurred by substitution of G442T in exon 4 and yielded a premature TGA stop codon. The stop codon was detected in one individual having the second lowest FMO activity and he had the mutation in heterozygous state. In a pedigree study, he was found to have inherited the mutation from his mother who also had a heterozygous stop codon and equally low FMO activity. In our volunteers, two other common mutations were detected in exons 4 and 7. The one in exon 4 resulted from a G472A change eliminating a HinfI restriction site and produced an amino acid substitution from Glu158 to Lys. The other mutation in exon 7 resulted from an A923G change generating a DraII restriction site and produced a non-conservative replacement of Glu308 to Gly. Based on the secondary structure maps of FMO3 enzyme proteins for these two mutant types, FMO3/Gly308 mutation transformed the helix structure into a sheet shape and indicated that dysfunctional FMO3 may be produced. FMO3/Lys158 mutation did not alter the secondary structure. Approximately 80% of volunteers with homozygous and/or heterozygous mutations on either one or two of these mutations had low FMO activities. Thus, individuals with these FMO3 gene mutations may have defective metabolic activity for many clinically used drugs and dietary plant alkaloids which are oxidized primarily by hepatic FMO3.

Generation of HLA-DP transgenic pigs for the study of xenotransplantation

The shortage of human organs has prompted scientists to seek xenogeneic sources of donors. To date, DAF, MCP, and CD59 transgenic pigs have been generated to inhibit hyperacute rejection. However, besides hyperacute rejection, acute and chronic rejection must also be considered in the use of porcine organs for xenotransplantation. The role of HLA-II in transgenic xeno-organ transplantation remains to be elucidated. By microinjecting 1655 embryos, we have generated one stillborn HLA-DR and two live HLA-DP transgenic pigs: P113-7 (male, carrying one copy of exogene) and P113-8 (female, carrying 2-3 copies of exogenes). The gene status of the live transgenic pigs was confirmed by PCR, Southern blot, and PCR product sequencing analysis. The expression of transgenes in these transgenic pigs were confirmed by RT-PCR analysis and immunohistochemical staining of frozen sections of ear tissue.