The coagulofibrinolytic state of patients with primary varicose veins of the lower legs

The relationship between a local hypercoagulable state and primary varicose veins of the lower legs was investigated by measuring the plasma levels of D-dimer (DD) and the thrombin-antithrombin-III complex (TAT) in 122 consecutive patients before treatment, and in 46 patients after surgical intervention and compression sclerotherapy. Elevated levels of DD and TAT were found in 25% and 20%, respectively, of the 122 patients, being significantly elevated in the patients with thrombophlebitis compared to the patients with no dermal symptoms, pigmentation, or stasis dermatitis. There was no significant difference in either parameter among eight groups of patients classified according to their valvular incompetence. The levels of DD and TAT were elevated before treatment in 25% and 20%, respectively, of 45 treated patients, but became significantly reduced after treatment. These results indicate that even though the local hypercoagulable state in varicose veins without thrombophlebitis is too subtle to be detected by systemic parameters such as DD and TAT, a local hypercoagulable state can be detected in a certain proportion of patients with venous stasis by these parameters.

Coordinated Regulation of the Genes Participating in Starch Biosynthesis by the Rice Floury-2 Locus

The recessive floury-2 (flo-2) locus of rice (Oryza sativa L.), which is located on chromosome 4, causes a strong reduction in expression of the gene encoding an isoform of branching enzyme RBE1 in immature seeds 10 d after flowering. Mapping of the RBE1 gene demonstrated the localization on rice chromosome 6, suggesting that the wild-type Floury-2 (Flo-2) gene regulates RBE1 gene expression in trans. However, reduced expression of the genes encoding some other starch-synthesizing enzymes, including another isoform of branching enzyme RBE3 and granule-bound starch synthase, was also found in the flo-2 seeds. In spite of the low level of RBE1 gene expression in the immature seeds of the flo-2 mutants, the RBE1 gene was equally expressed in the leaves of the wild type and flo-2 mutants. Thus, these results imply that the Flo-2 gene may co-regulate expression of some of the genes participating in starch synthesis possibly in a developing seed-specific manner.

Effects of acute and chronic ethanol administration on hepatic hemodynamics and hepatic oxygen consumption in awake rats

BACKGROUND/AIMS AND METHODS

We investigated the effects of acute and chronic ethanol administration on hepatic hemodynamics and hepatic oxygen delivery and consumption in awake rats, using the radiolabeled microsphere technique and measurement of oxygen content in blood.

RESULTS

Acute oral and intraarterial ethanol administration produced a significant increase in liver blood flow and hepatic oxygen delivery, but resulted in a significant (25-41%) decrease in hepatic oxygen consumption. These changes lasted up to 5 h after ethanol administration. At 24 h, hepatic oxygen consumption was significantly increased by 33% over control values. During withdrawal in rats fed liquid diets containing alcohol for 6 weeks, hepatic oxygen delivery was maintained at the same level as control pair-fed rats, while hepatic oxygen consumption increased by 28%. Further, in abstinent rats, acute ethanol readministration resulted in a 41% increase in hepatic oxygen delivery but a 32% decrease in hepatic oxygen consumption.

CONCLUSIONS

These findings demonstrate, in awake animals, a biphasic response of hepatic oxygen consumption following acute ethanol administration and an increase in hepatic oxygen consumption following chronic ethanol intake. Furthermore, acute ethanol treatment reduced hepatic oxygen consumption in spite of an increase in hepatic oxygen delivery.

Isolation and characterization of the rabbit cytochrome b5 gene

In mammals, two forms of cytochrome b5 (b5) are present and they are called according to their subcellar distribution as the microsomal-form and the soluble-form. These two forms of b5 s were encoded by separate mRNAs. In order to elucidate the mechanism of the expression of these two mRNAs, we isolated genomic clones that cover the gene for b5 from the rabbit genomic library. Analysis of these clones revealed that b5 gene spans over 20kbase pairs. A solube-form specific exon was found to be present between the two exons, which are in common to both forms of b5s. These observation demonstrate that the two forms of b5 mRNA are derived from the same gene by the alternative exon skip splicing.

In vivo evaluation of DX-9065a, a synthetic factor Xa inhibitor, in experimental vein graft

An in vivo effect of a novel synthetic Xa inhibitor, DX-9065a, was evaluated in a highly thrombogenic venous graft model. A woven Tetron tube graft was interposed in the inferior vena cava of rabbits. All the grafts were completely occluded within 5 hours after a bolus injection of heparin (50 U/kg) given just prior to the grafting. The following agents were continuously given to the respective group of rabbits for 2 h after the bolus injection of heparin; heparin (50 U/kg/h, UFH-group), DX-9065a (0.05 mg/kg/h, DX-group) and argatroban (32 microG/kg/h, MD-group). During a 5-h observation period, the anti-Xa activity in circulating blood between the UFH- and DX-group and the anti-thrombin activity between the UFH- and MD-group were not significantly different. The graft patency in the DX-group (4/4) and MD-group (4/4) was significantly better than that in the UFH-group (3/10). Ultrastructural analysis of the luminal surface of the harvested graft by scanning electron microscopy revealed the reduced formation of fibrin networks entrapping erythrocytes in the DX- and MD-group in comparison with the patent UFH-group. In conclusion, a novel synthetic Xa inhibitor DX-9065a exerts a potent in vivo antithrombotic effect, which was comparable with argatroban, a synthetic thrombin inhibitor.

Prevalence of impaired responsiveness to epinephrine in platelets among Japanese

The responsiveness of platelets only to epinephrine was markedly impaired in 23/140 (16%) healthy Japanese. The impaired responsiveness was not altered by changes in time and environment. Circulating level of catecholamines did not affect the responsiveness of platelets to epinephrine. A pilot family study indicated a possible familial nature of the defect. 3H methyl-yohimbine binding studies indicated that this defect was due to the decreased number of alpha 2 adrenergic receptor. Despite the defect, the potentiating effect of epinephrine on platelet aggregation stimulated by a low dose of ADP was normal. This abnormality is not apparently associated with any bleeding disorders and the clinical implication is unknown at present. It is, however, essential to acknowledge the prevalence of such defect in pursuing research on platelets stimulated by epinephrine.

The long-term effect of eicosapentaenoic acid on serum levels of lipoprotein (a) and lipids in patients with vascular disease

The effects of eicosapentaenoic acid (EPA) on serum lipoprotein (a) (Lp(a)) and other lipid levels in patients with vascular disease were examined. The serum levels of Lp(a), total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL) were measured in 24 patients with vascular disease. An elevated serum Lp(a) level (39 +/- 22 mg/dl) was noted in 9 patients, elevated total cholesterol level (263 +/- 31 mg/dl) in 12 patients, elevated triglyceride level (240 +/- 98 mg/dl) in 10 patients and elevated LDL level (651 +/- 88 mg/dl) in 6 patients before administration of EPA. EPA (1,800 mg/day) was given to these patients for long periods ranging from 6 to 24 months. The serum levels of Lp(a), TC, TG and LDL were lowered significantly (p < 0.05) after EPA administration for 12 and 18 months, for 6, 12, 18 and 24 months, for 18 months and for 12 and 18 months, respectively. These findings indicated that long-term administration of EPA may lower Lp(a) and serum lipids, which is beneficial for patients with various arterial diseases in terms of preventing progression of the disease.

Structure-antitumor activity relationship of semi-synthetic Spicamycin derivatives

New derivatives of spicamycin modified at the fatty acid moieties of the molecule were synthesized and their structure-activity relationships were examined. The antitumor activity was greatly influenced by modification of the fatty acid moieties to tetradecadienoyl or dodecadienoyl analogues exhibiting better antitumor activity against COL-1 human colon cancer xenograft than SPM VIII.

[A case of cerebral aneurysm located at the leptomeningeal artery associated with occlusion of the middle cerebral artery]

A case is presented of a ruptured aneurysm located at a leptomeningeal artery associated with an occlusion of the anterior trunk of the middle cerebral artery. A 60-year-old male had a sudden onset of severe headache and hemiplegia. CT showed a left frontal subcortical hematoma. Cerebral angiograms demonstrated an occlusion of the anterior trunk of the left middle cerebral artery with moyamoya phenomenon. In addition, an aneurysm was found arising from the leptomeningeal artery. The parent artery was filled with contrast medium from the middle internal frontal artery. We have reviewed literature and discussed the cause of an aneurysm located at the leptomeningeal artery. Hemodynamic factors were strongly suggested as the reason for the aneurysmal formation in this case.

Contained rupture of infected abdominal aortic aneurysm due to systemic candidiasis

A case is reported of contained rupture of an infected abdominal aortic aneurysm as a result of vascular catheter-associated candidiasis. Candida was identified in the mural thrombus taken from the aneurysm during surgery. Since Candida has played an important role in nosocomial infection and catheter-associated sepsis during the past decade, it is becoming an increasingly significant pathogen in microbial arteritis. Successful treatment included axillobifemoral bypass grafting followed by a complete excision of the infected aneurysm, retroperitoneal drainage and long-term antifungal therapy. Although infected abdominal aortic aneurysm is not common, without surgical intervention it may lead to serious consequences, such as rupture or uncontrollable sepsis. As the clinical symptoms of this disease are minimal and non-specific during the early stages, a high index of suspicion for this condition is essential for precise diagnosis and successful treatment. Moreover, initial treatment of candidiasis is especially important to prevent this rare but fatal late complication, infected abdominal aortic aneurysm.

Natural antibodies against the immunoglobulin F(ab')2 fragment cause elimination of antigens recognized by the F(ab')2 from the circulation

A humanized monoclonal IgG1 antibody, designated hC4G1, recognizes the fibrinogen receptor glycoprotein (GP)IIb/IIIa on platelets and inhibits platelet aggregation. When the F(ab')2 fragment of hC4G1 (F(ab')2 hC4G1) was administered to cynomolgus monkeys, all the monkeys showed inhibition of platelet aggregation ex vivo. Unexpectedly, a significant decrease in platelet count was observed in 5 of 18 monkeys. Antibodies against F(ab')2 hC4G1 were detected in the plasma of these monkeys by ELISA. Antibody activity in the plasma of these monkeys was significantly correlated with the intensity of platelet decrease (r = 0.84). The natural monkey antibodies to F(ab')2 hC4G1 were directed against the C-terminal region of F(ab')2 fragment common to all human and humanized IgG antibodies. Natural homo-reactive antibodies were also detected in human plasma from 15 of 40 healthy volunteers. Specificity was closely similar to that of the monkey antibodies. Affinity-purified human homoreactive antibodies enhanced phagocytosis of platelets treated with the F(ab')2 hC4G1. Monkey plasma with high homo-reactive antibody activity was confirmed to decrease platelet count when administered together with F(ab')2 hC4G1 to a monkey with low antibody activity. These results suggest that F(ab')2 of humanized and human antibodies causes elimination of the corresponding antigens from the circulation by homo-reactive antibodies.

Involvement of protein phosphatase-1 in cytoskeletal organization of cultured endothelial cells

The phosphorylation and dephosphorylation of cytoskeletal proteins regulate the shape of eukaryotic cells. To elucidate the role of serine/threonine protein phosphatases (PP) in this process, we studied the effects of calyculin A (CLA), a potent and specific inhibitor of protein phosphatases 1 (PP-1) and 2A (PP-2A) on the cytoskeletal structure of cultured human umbilical vein endothelial cells (HUVECs). The addition of CLA (5 min) caused marked alterations in cell morphology, such as cell constriction and bleb formation. Microtubules and F-actin were reorganized, becoming markedly condensed around the nucleus. Although the fluorescence intensity of phosphoamino acids was not significantly different according to immunocytochemistry between cells with and without CLA, polypeptides of 135, 140, 158, and 175 kDa were specifically phosphorylated on serine and/or threonine residues. There was no significant effect on tyrosine residues. The effects of CLA on cytoskeletal changes and protein phosphorylation were almost completely inhibited by the non-selective kinase inhibitor, K-252a. The effect of CLA on cell morphology was at least 100 times more potent than that of okadaic acid, consistent with the inhibitory potency against PP-1. The catalytic subunit of PP-1 was also identified in HUVECs by Western blotting with its monoclonal antibody antibody. These results suggest that PP-1 is closely involved in sustaining the normal structure of the cytoskeleton.

Shear stress induces expression of CNP gene in human endothelial cells

To elucidate the effect of blood flow on gene transcription of C-type natriuretic peptide (CNP), human umbilical vein endothelial cells were exposed to shear stress in a cone-plate viscometer. Expression of CNP mRNA, evaluated by reverse transcription-polymerase chain reaction, was markedly increased by exposure to shear stress of 24 dyne/cm2 at 3 h. The CNP mRNA level was maintained until 12 h. Thus, the present study demonstrated for the first time that shear stress induces expression of CNP gene in human endothelial cells.

Human T-lymphotropic virus type-I, and hepatitis A, B and C viruses in Nepal: a serological survey

In 1987, 676 blood samples were collected from inhabitants of the Bhadrakali and Kotyang villages in Nepal. The samples were tested for the prevalence of antibody to hepatitis A virus (anti-HAV), hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti-HBc), second-generation antibody to hepatitis C virus (anti-HCV) and antibody to human T-lymphotropic virus type-I (anti-HTLV-I). Anti-HAV was present in 99.3% of the people surveyed. The prevalence of anti-HAV reached 100% in the < 25 age group and was as high or only slightly lower in all other age groups. The prevalence of HBsAg was 0.3% and of anti-HBc 7.7%. Anti-HCV was found in 0.1% of the residents. No significant difference by gender or village was noted in the prevalence of anti-HAV, HBsAg, anti-HBc, or anti-HCV. No anti-HTLV-I-positive persons were identified. These data suggest that the prevalence of hepatitis B and C virus infections in Nepal is low in contrast to hepatitis A virus infection, and that human T-lymphotropic type-I infection may be absent in this population.

Hepatocellular carcinoma associated with lupoid hepatitis: a review of Japanese reports

A 66-year-old woman was diagnosed as having lupoid hepatitis due to the presence of hypergammaglobulinemia, lupus erythematosus cells, and positivity for antinuclear, anti-DNA, and anti-smooth muscle antibodies. None of the serum hepatitis B markers were positive. Symptomatic relief was obtained by prednisolone administration. Five years after the diagnosis of lupoid hepatitis, hepatocellular carcinoma (HCC) was detected by ultrasonography and computed tomography, after which hepatectomy was performed. Although transcatheter arterial embolization was done on two occasions and repeat hepatectomy was performed twice for recurrent HCC, her liver function remained good with the prednisolone treatment. Antibody for hepatitis C virus has been negative since our first check in 1992. As of this writing, the patient has been alive and well 6 years and 2 months after the first hepatectomy. There have been no previous reports of 6-year survival after hepatectomy for HCC associated with lupoid hepatitis.

Interferon-alpha 2a for chronic hepatitis B with e antigen or antibody:comparable antiviral effects on wild-type virus and precore mutant

Recombinant interferon-alpha 2a (IFN-alpha 2a) in a total dose of 702 MU was given to 31 patients: nine with wild-type hepatitis B virus (HBV) and hepatitis B e antigen (HBeAg) (A); four with HBeAg and a mixed infection with wild-type HB and precore mutants (B); 11 with antibody to HBeAg (HBeAb) and a mixed infection (C); and seven with HBeAb and precore mutants alone (D). HBV DNA was not cleared in any patient in groups A and B. By contrast, in patients with HBeAb, HBV DNA was ultimately lost in four patients in group C, as well as in 10 patients in group D. Thus, patients with HBeAb and infected with precore mutants alone (D) lost serum HBV DNA more often than those with HBeAg and wild-type HBV (A). Patients with low pretreatment levels of HBV DNA cleared virus more frequently, and the response of precore mutant to IFN was comparable with that of wild-type HBV in patients who had a mixed infection. Based on these results, precore mutants do respond to IFN, and therefore, IFN is indicated in patients with HBeAb, especially those with low serum HBV DNA levels.

Seasonal variation in 24-h blood pressure pattern of young normotensive women

To investigate the seasonal variations in ambulatory blood pressure patterns, 24-h blood pressure was measured every 15 minutes noninvasively in ten young normotensive women. Urine was collected every 4 hours. The examinations were repeated in spring, summer, autumn, and winter in a standardized living environment. The 24-h average systolic and diastolic blood pressures did not differ significantly among the seasons. Similarly, there were no significant differences in the average values of either daytime or nighttime blood pressure. In contrast, the average pulse rate during nighttime was significantly higher in winter than in summer (64 +/- 2 beats/min vs. 59 +/- 2 beats/min, p < 0.05). The variabilities of either blood pressure or pulse rate did not change significantly among the seasons. The mesors and acrophases of both systolic and diastolic blood pressures, determined by a single cosinor method, were not significantly different among the seasons. On the other hand, the acrophase of pulse rate appeared significantly later in winter (16:19) compared with those in spring (14:54), summer (14:42), and autumn (14:21). Urine volume and urinary excretion of norepinephrine were significantly greater in winter than in summer. These results indicate that the 24-h pattern of blood pressure is reproducible and shows no seasonal difference in young normotensive women.

Isolation and characterization of jararaca GPIb-BP, a snake venom antagonist specific to platelet glycoprotein Ib

A platelet glycoprotein Ib-binding protein (GPIb-BP) was isolated from the snake venom of Bothrops jararaca. Jararaca GPIb-BP showed a single band with M(r) of 30,000, and two distinct bands with M(r) of 17,000/13,000 under non-reducing and reducing conditions, respectively, on SDS-polyacrylamide gel electrophoresis. Jararaca GPIb-BP itself induced neither platelet aggregation nor serotonin release from platelets, but specifically bound to GPIb (40,629 +/- 2,521 molecules per normal platelet, with Kd 39.1 +/- 2.4 nM at saturation). The purified venom protein completely inhibited ristocetin- or botrocetin-induced von Willebrand factor (vWF) binding, and blocked the bovine vWF binding to GPIb, with IC50 values ranging from 28 to 42 nM, without affecting the platelet aggregation induced by ADP or alpha-thrombin. 125I-jararaca GPIb-BP binding to GPIb was not altered by the presence of human alpha-thrombin. Jararaca GPIb-BP at a final concentration of 104 nM totally abolished vWF-dependent shear-induced platelet aggregation (SIPA) at a high shear stress, but had no effect on SIPA at a low shear stress. Reduced and S-carboxyamido-methylated jararaca GPIb-BP lost its inhibitory activity on SIPA. The NH2-terminal amino acid sequences of the subunits revealed a high degree of homology with those of several Ca(2+)-dependent lectins, especially to those of two functionally opposite venom proteins, botrocetin (a vWF-modulator) and alboaggregin-B (a GPIb-modulator).

Calsequestrin is essential for the Ca2+ release induced by myotoxin alpha in skeletal muscle sarcoplasmic reticulum

Myotoxin alpha (MYTX), a polypeptide toxin purified from the venom of prairie rattlesnakes (Crotalus viridis viridis), induced Ca2+ release from the heavy fraction of skeletal sarcoplasmic reticulum (HSR), using a Ca2+ electrode. The effect of MYTX was nearly abolished by pretreatment with ryanodine, an alkaloid-based Ca2+ channel blocker. In the stopped-flow experiments, MYTX increased the choline+ permeability of HSR in the presence of calsequestrin (CS). Single channel recording experiments showed that in the presence of CS, the channel currents were markedly enhanced by MYTX applied to the cis side, but not to the trans side. However, in the absence of CS, MYTX failed to cause the excitatory effect in both the experiments. These results suggest that CS is essential for MYTX-induced Ca2+ release through the Ca2+ release channels in skeletal HSR.

Antihypertensive effects of angiotensin fragments in SHR

When angiotensin fragments, Val-Tyr and Angiotensin III (ANG III), with potent ACE inhibitory activity were intravenously administered to spontaneously hypertensive rat (SHR), a significant reduction of diastolic blood pressure was observed. After incubation of ANG III with SHR plasma, four fragments with ACE inhibitory activity, Val-Tyr (ANG (3-4)) (IC50 = 26.0 microM), Ile-His-Pro-Phe (ANG (5-8)) (11.6 microM), Tyr-Ile-His-Pro-Phe (ANG (4-8)) (457.5 microM), and Val-Tyr-Ile-His-Pro-Phe (ANG (3-8)) (6.55 microM), were confirmed to generate in SHR plasma. Compared the metabolic behavior of ANG II in SHR plasma with that in normotensive Wistar plasma, the initial degradation rate (3.07 nmol/ml/min) in Wistar plasma was about 2-fold higher than that in the SHR one (1.75 nmol/ml/min).

PGI2 analogue, sodium beraprost, suppresses superoxide generation in human neutrophils by inhibiting p47phox phosphorylation

Sodium beraprost, a newly synthesized PGI2 analogue inhibited in a dose-dependent manner formyl-methionyl-leucyl-phenylalanine (fMLP) induced superoxide generation of human neutrophils, but it had no effect on the superoxide synthesis by phorbol myristate acetate (PMA) or A23187. Sodium beraprost inhibited Ca2+ influx in fMLP stimulated neutrophils employing fluorometry and confocal microscopy. These findings suggested that the inhibitory effect of sodium beraprost on fMLP induced superoxide generation was due to suppression of Ca2+ influx. To examine the relationship between the effect of sodium beraprost and phosphorylation of p47phox (the 47kDa cytosolic phagocyte oxidase factor), immuno-precipitation of p47phox and western blotting for phospho-amino acids were performed. Phosphorylation of serine residues of p47phox induced by fMLP was reduced in the presence of sodium beraprost in a dose-dependent manner. The reduction in phosphorylation was accompanied by a reduction in p47phox and p67phox translocation to the plasma membrane and superoxide generation. These findings suggested that p47phox phosphorylation was necessary for translocation and superoxide generation in fMLP activated neutrophils, and that p47phox phosphorylation was regulated by a Ca2+ dependent mechanism. These observations suggested that sodium beraprost inhibited fMLP induced superoxide generation of human neutrophils by the inhibition of p47phox phosphorylation and translocation by a Ca2+ dependent mechanism.

Clearance of serum hepatitis C virus RNA after interferon therapy in relation to virus genotype

The effect of recombinant interferon-alfa on serum HCV RNA levels in Japanese patients with chronic hepatitis C was investigated. At 24 weeks of treatment, 41 (32.5%) of 126 patients lost HCV RNA from serum, and aminotransferases were normalized in 31 (75.6%) of these 41 cases. HCV genotypes were categorized into four types (Type I, II, III, IV); the frequencies among the patients were: Type I: 0%, Type II: 70.6%, Type III: 20.6%, and Type IV: 6.3%. At the end of the 24-week treatment, HCV RNA levels were remarkably decreased in Type III patients and became undetectable in 18 (69.2%) of 26. In contrast, only 18 (20.2%) of 89 patients with Type II and two of eight with Type IV lost HCV RNA from sera. The relation between HCV genotype (Type III) and response to IFN therapy was also confirmed using a logistic regression model. HCV genotype seems to be an important factor in determining the response to IFN in patients with chronic hepatitis C.

Suppression of pseudointimal hyperplasia by a novel prostacyclin analogue: beraprost

The aim of this study was to evaluate the effect of a novel prostaglandin I2 analogue, beraprost (BPT), on the pseudointimal hyperplasia (PIH) of polytetrafluoroethylene (PTFE) prostheses. A total of 12 rabbits were equally divided into three groups. The control group was given a placebo daily, group 1 was given BPT orally 2 mg/kg per day, and group 2 was given BPT orally 4 mg/kg b.i.d. Exactly 1 cm of the inferior vena cava was resected and replaced by a 3-cm PTFE tube graft. All the grafts were patent when harvested 4 weeks after implantation, but the lumens were narrowed to various extents by PIH. PIH, determined by the dry weight of the intraluminal tissue deposit, was significantly (P < 0.01) suppressed in groups 1 and 2 compared with the control group. High-magnification light microscopy with various staining methods revealed the PIH to be composed mainly of smooth muscle cells (SMCs) and collagen fibrils in all three groups. Transmission electron microscopy revealed that the majority of SMCs in groups 1 and 2 were contractile in form, in contrast with the synthetic form seen in the control group. In conclusion, BPT attenuated the PIH of PTFE grafts by inhibiting the phenotype change in the SMCs.