Risk of clot formation with ionic and nonionic contrast media in cerebral angiography. Tama Contrast Media Study Group

RATIONALE AND OBJECTIVES

The introduction of low-osmolality contrast media has improved patient tolerance to angiographic procedures. However, nonionic contrast media may be associated with an increase in the risk of clot formation. The objective of this study was to test whether there is more clotting with nonionic agents than with ionic agents.

METHODS

Ninety-eight patients undergoing transfemoral cerebral angiography were randomly assigned to receive ionic (ioxaglate) (n = 62) or nonionic (iopamidol or iohexol) (n = 36) contrast material. Incidence of clot formation was examined by observation of catheters.

RESULTS

Clot formation was found in 4.8% of patients in the ionic contrast material group and 22.2% of patients in the nonionic contrast material group (P < .05).

CONCLUSION

Nonionic contrast media resulted in a statistically significantly higher incidence of clot formation than ionic media during cerebral catheter angiography. These results suggest that ionic contrast media are preferable in patients with risk of thrombosis.

[Atherosclerosis and clinical examination: epidemiology of stroke and ischemic heart disease]

We discussed the risk factors for stroke and ischemic heart disease (IHD) as a main atherosclerotic disease. We showed that hypertension was the most principal risk factor for both cerebral hemorrhage and cerebral infarction, and the increase of total cholesterol (TCH) was inversely related with the incidence of cerebral hemorrhage. Many of the cerebral infarctions occurred where a large number of the cerebral hemorrhages did. We indicated that the mechanism of occurrence was different between stroke and IHD. In Japan, TCH has been recognized as a risk factor for IHD as same as western countries, but there are not many IHD. The mean of TCH was lower before one or two decade. But, it has increased in the last decade, and recently is nearing the level of American people in the thirties and forties. Death statistics of IHD became more accurate in Japan by reason for revision of the death certificate form from ICD-9 to ICD-10. The recognition of IHD death statistics will be changed. Incidence of stroke has been decreasing because of the decrease of hypertension. However, we will have to reconsider a preventive measure of IHD.

Identification of two Xenopus laevis genes, xMCM2 and xCDC46, with sequence homology to MCM genes involved in DNA replication

The Schizosaccharomyces pombe genes, nda1 and nda4, are essential for the normal regulation of DNA replication and belong to the MCM gene family. This gene family includes Saccharomyces cerevisiae MCM2, MCM3, MCM5/CDC46 and CDC47, S. pombe nda1, nda4, cdc21 and mis5, and genes encoding human BM28, P1MCM3 and P1.1MCM3 and mouse P1MCM3, most of which are considered to be required for the initiation of DNA replication. We isolated two homologues of the MCM genes, xMCM2 and xCDC46, from a Xenopus laevis cDNA library using the polymerase chain reaction (PCR) method. The predicted amino acid (aa) sequences of xMCM2 and xCDC46 are most similar to those of human BM28 (78% identity) and S. pombe Nda4 (48% identity), respectively. By Western blot analysis using anti-xMCM2 and anti-xCDC46 polyclonal antibodies (Ab) raised against glutathione S-transferase (GST)::xMCM2 or GST::xCDC46 fusion proteins, xMCM2 and xCDC46 were identified as 120- and 95-kDa proteins, respectively. When either xMCM2 or xCDC46 was immunoprecipitated with the specific Ab, the other was also co-precipitated. These results suggest that xMCM2 and xCDC46 physically interact with each other.

Prevalence of Mycoplasma genitalium in men with gonococcal urethritis

A significant association of Mycoplasma genitalium with non-gonococcal urethritis has been reported, but the prevalence of this mycoplasma in men with gonococcal urethritis has not been so well studied. In this study, we examined urethral swab specimens from 45 Japanese male patients with gonococcal urethritis for the presence of M. genitalium by using a polymerase chain reaction-based assay. We also sought Chlamydia trachomatis by an enzyme immunoassay (Chlamydiazyme). Of the 45 specimens, 2 (4.4%) were positive for the mycoplasma and 12 (26.7%) were positive for C. trachomatis. The findings suggest that M. genitalium may be a cause not only of non-gonococcal urethritis but also of postgonococcal urethritis.

Catalytic activities of hammerhead ribozymes with a triterpenoid linker instead of stem/loop II

A minizyme is a hammerhead ribozyme with short oligonucleotide linkers instead of stem/loop II. In a previous study we demonstrated that a minizyme with high-level activity forms a dimeric structure with a common stem II (Amontov and Taira, J. Am. Chem. Soc., 118 (1996) 1624-1628). As a continuation of this study, we recently examined whether a short oligonucleotide linker at stem/loop II could be replaced by a triterpenoid linker and whether the resulting minizymes with bulky hydrophobic groups would form dimeric structures. In contrast to the minizyme with high-level activity that we characterized in the previous study, minizymes that contained a triterpenoid group had low cleavage activities. The nature of the dependence of the activity on the concentration of ribozyme revealed that these minizymes with a triterpenoid group do not form dimeric structures. Thus, the low activities of these structures can be attributed to their failure to form dimers.

Rapid detection of point mutations of the Neisseria gonorrhoeae gyrA gene associated with decreased susceptibilities to quinolones

Mutations in the gyrA gene resulting in amino acid changes at Ser-91 and Asp-95 are significantly associated with decreased susceptibilities to quinolones in Neisseria gonorrhoeae. To detect these mutations, we developed a rapid and simple assay based on amplification of the region of the gyrA gene containing the mutation sites by PCR and digestion of the PCR product with a restriction enzyme. A naturally occurring HinfI restriction site was present in the region containing the Ser-91 codon, and an artificial HinfI restriction site was created in the region containing the Asp-95 codon by the method of primer-specified restriction site modification. The mutations generating alterations at Ser-91 and Asp-95 were detected as restriction fragment length polymorphisms of the PCR products digested with HinfI. Fifty-five clinical strains of N. gonorrhoeae were examined for mutations in the gyrA gene by this method. Mutations at Ser-91 and/or Asp-95 were detected in all the 31 strains in which the mutations had been confirmed by DNA sequencing. Our method allows simultaneous testing of a large number of strains and provides results within 8 h. This rapid and simple assay could be a useful screening device for genetic alterations associated with decreased susceptibilities to quinolones in N. gonorrhoeae and could facilitate epidemiological studies on clinical isolates of N. gonorrhoeae with decreased susceptibilities to quinolones.

Effect of mitochondrial and/or cytosolic glycerol 3-phosphate dehydrogenase overexpression on glucose-stimulated insulin secretion from MIN6 and HIT cells

The glycerol phosphate shuttle consists of FAD-linked mitochondrial glycerol 3-phosphate dehydrogenase (mGPDH) and its cytosolic NAD-linked isoform (cGPDH). Impaired mGPDH activity has recently been suggested to be one of the primary causes of insulin secretory defects in beta-cells. We found that mGPDH and cGPDH activities in MIN6 cells are comparable to those of isolated islets and higher than those in HIT cells by eightfold and threefold, respectively. Therefore, we selected the MIN6 cell line as a beta-cell model with normally regulated insulin secretion and normal shuttle enzyme activities and the HIT cell line as a beta-cell model with impaired insulin secretion and lower activities of these enzymes. The role of these dehydrogenases in glucose-stimulated insulin secretion was addressed by examining the effects of overexpression of mGPDH and/or cGPDH via recombinant adenoviruses in these cells. Infection with recombinant adenovirus with a cDNA encoding the Escherichia coli beta-galactosidase gene resulted in expression of its gene in 90% of MIN6 and HIT cells. Infection with a recombinant adenovirus with mGPDH cDNA (Adex1CAmGPDH) caused 2.1-fold and 5.7-fold increases in dehydrogenase activity as compared with those of control MIN6 and HIT cells, respectively. Infection with a recombinant adenovirus with cGPDH cDNA (Adex1CAcGPDH) caused a more than 50-fold increase in activity in both cell lines. Glycerol phosphate shuttle flux, as estimated by [2-3H]glycerol conversion to [3H]H2O, was increased to 120-130% by infection with Adex1CAmGPDH, but not with Adex1CAcGPDH infection, in both MIN6 and HIT cells. No further increase in flux through the glycerol phosphate shuttle was detected when the cells were infected with Adex1CAmGPDH together with Adex1CAcGPDH. Furthermore, neither [U-14C]glucose oxidation nor the insulin secretory response to glucose was affected in either cell line. Thus, mGPDH abundance in MIN6 and HIT cells is not directly related to their insulin secretory capacity in response to glucose, and reduced expression of mGPDH is not the primary cause of abnormal insulin secretory responses in HIT cells. The present data indicate that the emerging hypothesis pointing to mGPDH deficiency as a possible cause of NIDDM needs to be carefully evaluated.

Short-term clinical trial of 1-(1-[4-(3-acetylaminopropoxy)-benzoyl]-4-piperidyl)-3, 4-dihydro-2(1H)-quinolinone in patients with diabetic nephropathy. Possible effectiveness of the specific vasopressin V1 receptor antagonist for reducing albuminuria in patients with non-insulin dependent diabetes mellitus

We investigated the role of arginine vasopressin (AVP) in the development of diabetic nephropathy and the effect of specific vasopressin V1 receptor antagonist of 1-(1-[4-(3-acetylaminopropoxy)-benzoyl]-4-piperidyl)-3, 4-dihydro-2(1H)-quinolinone (CAS 131631-89-5, OPC-21268) on albuminuria in patients with non-insulin dependent diabetes mellitus. Basal levels of AVP in diabetic patients showing microalbuminuria were significantly high compared to diabetics without any complications, suggesting that in those patients abnormally high amounts of AVP seem to be secreted. Three-week treatment with OPC-21268 demonstrated that albuminuria significantly decreased without affecting renal function. Increased secretion of AVP may induce proliferation of renal mesangial cells and modify blood flows in the glomerular capillaries. The present data suggest that OPC-21268 may be useful for preventing the development of diabetic nephropathy, although its long-term effects should be examined. In conclusion, AVP may play a crucial role in the pathophysiology of diabetic nephropathy and that OPC-21268 seems to prevent further progression of nephropathy in non-insulin dependent diabetes mellitus.

Use of von Willebrand factor promoter to transduce suicidal gene to human endothelial cells, HUVEC

Angiogenesis is an essential component of multifactorial carcinogenesis and thus a potential target of therapeutic intervention. To develop a novel cancer gene therapy strategy based on suppression of tumor angiogenesis, we examined the feasibility of targeting and preferential killing of proliferating endothelial cells by use of the von Willebrand factor (vWf) promoter and herpes simplex virus thymidine kinase gene (HSV-TK). Based on previous reports on the vWf promoter, we tested two putative vWf promoter regions. The luciferase assay showed that the shorter region, which encompasses most of the first noncoding exon, had stronger activity in endothelial cells. Although the promoter activity was low when employed as an internal promoter for retroviral and adenoviral vectors, endothelial cell specificity was suggested; the promoter, when used to drive the HSV-TK gene, could preferentially suppress endothelial cell growth in the presence of prodrug ganciclovir, suggesting the feasibility of designing an anti-angiogenesis gene therapy using the vWf promoter and the suicide gene/prodrug strategy.

Generation and characterization of mutant mice lacking ryanodine receptor type 3

The ryanodine receptor type 3 (RyR-3) functions as a Ca2+-induced Ca2+ release (CICR) channel and is distributed in a wide variety of cell types including skeletal muscle and smooth muscle cells, neurons, and certain non-excitable cells. However, the physiological roles of RyR-3 are totally unclear. To gain an insight into the function of RyR-3 in vivo, we have generated mice lacking RyR-3 by means of the gene targeting technique. The mutant mice thus obtained showed apparently normal growth and reproduction. Although Ca2+-induced Ca2+ release from intracellular Ca2+ stores of the mutant skeletal muscle differed in Ca2+ sensitivity from that of wild-type muscle, excitation-contraction coupling of the mutant muscle seemed to be normal. Moreover, we could not find any significant disturbance in the smooth muscle and lymphocytes from the mutant mice. On the other hand, the mutant mice showed increased locomotor activity, which was about 2-fold greater than that of the control mice. These results indicate that the loss of RyR-3 causes no gross abnormalities and suggest that the lack of RyR-3-mediated Ca2+ signaling results in abnormalities of certain neurons in the central nervous system.

Anti-atherosclerotic effect of E5324, an inhibitor of acyl-CoA:cholesterol acyltransferase, in Watanabe heritable hyperlipidemic rabbits

E5324, n-butyl-N'-[2-[3-(5-ethyl-4-phenyl-1H-imidazol-1-yl)propoxy]-6- methylphenyl]urea, a novel and potent inhibitor of acyl-CoA:cholesterol acyltransferase (ACAT), was evaluated for its anti-atherosclerotic and lipid-lowering effects in Watanabe heritable hyperlipidemic (WHHL) rabbits. At 3 months of age, 40 male WHHL rabbits were divided into 4 groups. The rabbits were fed a standard rabbit chow (control group), or standard rabbit chow containing E5324 (0.1% or 0.02%) or 1% probucol for 16 weeks. Even the high dose of E5324 did not lower the plasma total cholesterol levels throughout the experiment. Probucol slightly reduced the plasma cholesterol levels, and showed anti-atherosclerotic activity, i.e., reductions of atherosclerotic plaque formation and cholesterol content in the aorta. Although E5324 did not lower plasma cholesterol, atherosclerotic plaque formation in the aortic arch and thoracic aorta was reduced (by about 34% and 41%, respectively, at the high dose; P < 0.05). Cholesterol content in the aortic arch and thoracic aorta was also reduced (by about 59% and 62% at the high dose, respectively) compared with the control. These results suggest that E5324 acts directly on the arterial wall through ACAT inhibition, and prevents the progression of atherosclerosis in WHHL rabbits.

Transgenesis by adenovirus-mediated gene transfer into mouse zona-free eggs

Zona-free mouse eggs at the pronucleus stage were infected with a replication-defective adenovirus vector containing a nuclear-targeted lacZ gene. Exogenous beta-galactosidase activity was detected in almost all eggs at the two-cell stage. Of 27 mice that developed from infected eggs, three carried the integrated exogenous gene mediated by the adenovirus. Two of the three expressed the lacZ gene, and all three mice transmitted the adenovirus-mediated transgene to F1 progeny Southern blot analysis was consistent with single copy integration. This finding should accelerate the development of new strategies for transgenesis and assist studies on the function of cloned genes in vivo.

Probucol downregulates E-selectin expression on cultured human vascular endothelial cells

Probucol, which inhibits monocyte adhesion, is a potent antioxidant to vascular endothelium in the cholesterol-fed rabbit. The accumulation of macrophages in the lesion is influenced by increased expression of specific adhesion molecules on vascular endothelial cells. We investigated the effect of probucol on the expression of cell adhesion molecules in cultured human umbilical vein endothelial cells (HUVECs). HUVECs were treated with lipopolysaccharide in the presence or absence of probucol (0 to 5 mumol/L) and assayed for the expression of adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) and E-selectin by cell-enzyme-linked immunosorbent assay. Probucol significantly downregulated the expression of E-selectin on HUVECs in a dose-dependent manner. In contrast, the expression of ICAM-1 was not affected. E-selectin but not ICAM-1 mRNA expression on HUVECs was also significantly inhibited by probucol in a dose-dependent manner. We also examined whether probucol affects cellular binding between the human monocytic cell line U937 and lipopolysaccharide-stimulated HUVECs by using an in vitro binding assay and found that probucol significantly suppressed their mutual binding in a dose-dependent manner. These data indicate a novel mechanism of action for probucol to reduce the development of atherosclerotic lesions in hyperlipidemic states.

Induction of intercellular adhesion molecule-1 in human nasal epithelial cells during respiratory syncytial virus infection

The effects of infection with respiratory syncytial virus (RSV) on expression of intercellular adhesion molecule (ICAM)-1 was determined in vitro in nasal epithelial cell cultures. Functional consequences of changes in ICAM-1 expression were assessed by measuring adhesion of a human leukaemic T-cell line to RSV-infected epithelial cells. Also, adhesion of phytohaemagglutinin-activated tonsillar lymphocytes (TL) to RSV-infected epithelial cells caused a significant increase in interleukin (IL)-4 or IL-5 production. Release of these cytokines was adhesion dependent as non-adherent TL produced significantly less IL-4 or IL-5. However, no significant difference was observed for IL-2 or interferon-gamma (IFN-gamma) production. These observations suggest that RSV-infected epithelial cells may induce T-helper type-2 (Th2)-like cytokines by mucosal lymphocytes during mucosal infection in vivo.

Upregulated expression of chemokines in herniated nucleus pulposus resorption

STUDY DESIGN

Immunohistologic examination was performed on surgically removed samples of herniated nucleus pulposus.

OBJECTIVES

To determine what cell types predominate in the granulation tissues of herniated nucleus pulposus, and to elucidate whether chemokines are involved in the resorption process of herniated nucleus pulposus. SUMMARY OF BACKGROUND DATA. The study population consisted of 30 patients suffering from herniated nucleus pulposus. Five macroscopically normal discs were obtained from spinal cord tumor and spinal cord injury managed with anterior discectomy (age range, 27-63 years) as a healthy control group.

METHODS

Immunohistochemical analysis was used to analyze the expression of chemokines.

RESULTS

A marked infiltration of macrophage and vascular proliferation was identified with a T lymphocyte infiltration of mild degree in the granulation tissues. This tendency was more prominent in the exposed group compared with the nonexposed group. Infiltrating macrophages, fibroblasts, and endothelial cells in the granulation tissues strongly expressed monocyte chemotactic protein-1 and macrophage inflammatory protein-1 alpha. Statistical analysis demonstrated that the exposed group was more abundant in Factor VIII, monocyte chemotactic protein-1, and macrophage inflammatory protein-1 alpha positive cells than the unexposed group.

CONCLUSIONS

Inflammatory cells and their positivity for chemokines, such as monocyte chemotactic protein-1 and macrophage inflammatory protein-1 alpha, are associated with blood vessels. Chemokines, such as monocyte chemotactic protein-1 and macrophage inflammatory protein-1 alpha, were overexpressed in macrophages, fibroblasts, and endothelial cells, suggesting that these chemokines contribute to activation and recruitment of macrophages in a paracrine or autocrine fashion.

Shared amino acid motifs in T-cell receptor beta junctional regions of bronchoalveolar T cells in patients with pulmonary sarcoidosis

To clarify the nature of the accumulated lung T cells of pulmonary sarcoidosis, we studied bronchoalveolar and peripheral blood (PB) lymphocytes from Japanese patients for expressed T-cell receptor beta-chain variable (TCR V beta) gene usage. Quantitative polymerase chain reaction technique revealed that the V beta repertoires of bronchoalveolar and PB T cells were heterogeneous. However, the bronchoalveolar lymphocytes from five out of 10 patients showed overrepresentation of T cells, with a few TCR V beta families, which varied among individuals, possibly reflecting a difference in the human leukocyte antigen (HLA) backgrounds. Nucleotide sequence analysis of third complementarity determining region (CDR3) segments in overrepresented V beta families demonstrated limited diversity of the transcripts. Two HLA-DR 12(5)+ individuals with overrepresented V beta 6 gene transcripts in the lungs shared a common amino acid motif within their CDR3. By contrast, non-overrepresented TCR V beta transcripts did not show clonal expansion, and the oligoclonal clones in the lung were not found in PB of the corresponding patient. These results showed that, at least in subsets of Japanese patients with pulmonary sarcoidosis, a limited number of T-cell clones are accumulated in the lung in response to a specific antigen. They may mediate an immune response to shape pathology of the disease.

Thromboxane synthetase inhibitor ameliorates delayed neuronal death in the CA1 subfield of the hippocampus after transient global ischemia in gerbils

Thromboxane A2 accumulates in the hippocampus after global ischemia and may play a key role in postischemic hypoperfusion. Thromboxane synthetase inhibitor (OKY-046) inhibits the accumulation of thromboxane A2 and promotes prostacycline production. Therefore, we set out to determine whether the inhibition of thromboxane synthesis would ameriolate postischemic neuronal death. Three groups of six Mongolian gerbils were subjected to different treatments: untreated control, untreated ischemia, and treated ischemia. Immediately after forebrain ischemia, OKY-046 (10 mg/kg) was injected intraperitoneally into the treated group. After 7 days of survival, the histopathology of the brain was examined. Pyramidal cell density in the CA1 sector in the treated group was 147 +/- 70 nuclei/mm (mean +/- SD), which was significantly (p < 0.05) higher than than in the untreated group (33 +/- 10 (nuclei/mm). The findings were 231 +/- 7 nuclei/mm for the control group. No significant difference was seen in the profile of temporal muscle temperature before and after ischemia between the groups. Ultrastructurally, the vessels in the CAI sector showed lumen patency in the treated group, whereas occluded vessels with an extended perivascular space were observed in the untreated group. Thromboxane synthetase inhibitor thus partly ameliorates the selective vulnerability of the hippocampus after forebrain ischemia, suggesting that thromboxane A2 is involved in the development of delayed neuronal death, independently of any thermal effect.

Morphometrical analysis of nucleolin immunohistochemistry in meningiomas

Nucleolin (110 kDa) is a major nucleolar protein in eukaryotic cells and one of the nucleolar organizer region (NOR)-associated proteins. We studied immunohistochemically 32 cases of meningioma, using specific antisera against nucleolin, and analyzed various nucleolin parameters, such as the number of regions and the total area of nucleolin staining per nucleus. The mean number and area of nucleolin stainings per nucleus were compared with the histological malignancy and Ki-67/MIB-1 proliferation index; the correlation with parameters of silver-stained NOR (AgNOR) was also studied. The results showed that there were statistically significant differences in the mean number and area of nucleolin stainings per nucleus between meningiomas and other two groups, atypical and anaplastic meningiomas (P < 0.05), although there was no difference between atypical and anaplastic meningiomas. The mean number and area of nucleolin stainings per nucleus were correlated with the incidence of Ki-67 positivity and AgNOR area. In view of the technical problems inherent in AgNOR staining, immunohistochemistry for nucleolin may represent a more specific and reproducible means for NOR visualization and be a promising technique for assessing cell proliferation.

Comparison among performances of a ligase chain reaction-based assay and two enzyme immunoassays in detecting Chlamydia trachomatis in urine specimens from men with nongonococcal urethritis

We evaluated the performances of a ligase chain reaction (LCR)-based assay and two enzyme immunoassays (Chlamydiazyme and IDEIA) in the detection of Chlamydia trachomatis in urine specimens. We compared the results of testing urine specimens by these assays with those of urethral swab culture by examining samples from 131 men with nongonococcal urethritis. Discrepant results were analyzed by testing urethral swab specimens for C. trachomatis by a PCR-based assay. After the resolution of discrepant results, the sensitivity of urethral swab culture was 85.3%, whereas those of the LCR assay, Chlamydiazyme, and IDEIA with urine specimens were 94.1, 82.4, and 94.1%, respectively. The LCR assay and IDEIA were more sensitive than was urethral swab culture. In addition, the LCR assay, with a sensitivity equal to that of IDEIA, was more specific. Overall, the LCR assay proved to be superior to the enzyme immunoassays in detecting C. trachomatis in urine specimens. Testing urine specimens by LCR assay should be a helpful alternative method for diagnosing C. trachomatis urethral infection in men with nongonococcal urethritis.

Mechanisms of satigrel (E5510), a new anti-platelet drug, in inhibiting human platelet aggregation. Selectivity and potency against prostaglandin H synthases isozyme activities and phosphodiesterase isoform activities

Satigrel (E5510, 4-cyano-5,5-bis(4-methoxyphenyl)-4-pentenoic acid) is a potent inhibitor of platelet aggregation. Like cyclooxygenase/prostaglandin H synthase (PGHS) inhibitors such as aspirin, which suppress platelet aggregation by inhibiting thromboxane A2 production, satigrel inhibits collagen- and arachidonic acid-induced aggregation of human platelets. In contrast to other PGHS inhibitors, satigrel, like cyclic nucleotide phosphodiesterase (PDE) inhibitors such as cilostazol, shows inhibitory activity against thrombin-induced platelet aggregation. To investigate the mechanism of the anti-platelet activity of satigrel, we examined the selectivity and potency of satigrel against PGHS isozyme activities and PDE isoform activities. Two isozymes of PGHS are known; constitutive enzyme (PGHS1) and inducible enzyme (PGHS2). Satigrel showed inhibitory activity against PGHS1 (IC50: 0.081 microM) and PGHS2 (IC50: 5.9 microM), suggesting the selective inhibition of PGHS1. Indomethacin, which is a selective inhibitor of PGHS1, showed similar selectivity against PGHS isozymes (IC50: 0.12 microM and 1.4 microM, respectively). These results support that satigrel suppresses thromboxane A2 production by inhibiting PGHS1. It is known that three isozymes of PDE exist in human platelets: Type V, which specifically hydrolyzes guanosine 3',5'-cyclic monophosphate (cGMP), Type III, which mainly hydrolyzes cAMP, and Type II, which hydrolyzes both cGMP and cAMP. We separated these three isozymes from human platelets and examined the inhibitory activity of satigrel against each enzyme. Of the three isozymes, the inhibitory activity of satigrel was the most potent against Type III PDE (IC50: 15.7 microM). The IC50 value for Type III corresponded with that for thrombin-induced platelet aggregation. Type V and Type II were also inhibited by satigrel (IC50: 39.8 and 62.4 microM, respectively). In human platelets, satigrel increased both cAMP and cGMP levels in a dose-dependent manner (100, 300 microM). In conclusion, satigrel inhibits collagen- and arachidonic acid-induced platelet aggregation through preventing thromboxane A2 synthesis by selective inhibition of the target enzyme, PGHS1, which exists in platelets. The anti-aggregating activity of satigrel against thrombin-induced aggregation may be due to elevation of the cyclic nucleotide levels through the inhibition of PDE isozymes.

Gene therapy for alpha-fetoprotein-producing human hepatoma cells by adenovirus-mediated transfer of the herpes simplex virus thymidine kinase gene

We have developed a recombinant replication-defective adenovirus containing human alpha-fetoprotein (AFP) promoter/enhancer to direct cell type-specific expression of the herpes simplex virus thymidine kinase (HSVtk) gene to AFP-producing hepatocellular carcinoma (HCC) cells. After an in vitro infection by a recombinant adenovirus carrying the lacZ gene under the control of human AFP promoter/enhancer (AdAFPlacZ), an expression of the lacZ gene was demonstrated efficiently in AFP-producing HuH-7 and HepG2 cell lines, but not in AFP-nonproducing HLE and HLF cell lines, although lacZ gene expression was demonstrated in all these cell lines when infected with adenovirus vector carrying lacZ gene driven by the beta-actin-based promoter. Expression of the HSVtk gene by adenovirus, from AFP promoter/enhancer (AdAFPtk) induced the cells sensitive to ganciclovir (GCV) in the AFP-producing cell line efficiently, but not in AFP-nonproducing HLF hepatoma cells. An in vitro bystander effect was observed when only 10% of the cells were infected with AdAFPtk. These findings suggest that the AFP promoter/enhancer sequence can provide the tumor-specific activity for the therapeutic gene expression, and that the AdAFPtk vector induces the selective growth inhibition by GCV in the adenovirus-infected human hepatoma cells in vitro. Recombinant adenovirus transfer of the HSVtk gene under the control of tumor-specific promoter followed by GCV may have promise as a targeted in situ treatment for solid neoplasms.

Insulin resistance syndrome in adolescents and adults

This study was designed to investigate the possibility of sex and age differences in the insulin-blood pressure relationship in a general Japanese population with a wide age range. Fasting serum insulin, lipids, plasma glucose, blood pressure and anthropometric measurements were made on 1,537 men and 843 women aged 16 to 65 years. Of the 2,380 subjects in the present analysis, 290 (184 men, 106 women) were hypertensive. When divided into four age groups (16 to 17, 21 to 22, 30 to 49 and 50 to 65 years), the male hypertensive subjects were found to have significantly higher fasting insulin levels, triglycerides levels and body mass index and lower glucose/insulin ratios than normotensive male subjects in all age groups. In the women, there was no significant difference in serum insulin levels or glucose insulin ratios between the hypertensive and normotensive groups in any age group. Simple correlation analysis showed that blood pressure was statistically significantly correlated with serum insulin levels and body mass index in the men in all age groups. In women, the correlation between blood pressure and serum insulin was insignificant in the 21- to 22-year-old age group. In men but not women, multivariate analysis showed that blood pressure was significantly and independently correlated with fasting serum insulin levels. The results of this study suggests the existence of sex and age differences in the insulin-blood pressure relationship in a Japanese population.