Real-world efficacy and safety of 12-week sofosbuvir/velpatasvir treatment for patients with decompensated liver cirrhosis caused by hepatitis C virus infection

AIM

This study aimed to evaluate the real-world efficacy and safety of 12-week sofosbuvir/velpatasvir (SOF/VEL) treatment for patients with decompensated liver cirrhosis caused by hepatitis C virus (HCV) infection.

METHODS

A total 72 of patients with Child-Pugh (CP) class B or C were enrolled. We evaluated the sustained virologic response at 12 weeks after the end of treatment (SVR12), adverse events (AEs), and changes in the liver function.

RESULTS

All participants had genotype 1 or 2 HCV infection. At baseline, the numbers of patients with CP class B and C were 59 and 13, respectively. The overall SVR12 rate was 95.8% (69/72); 94.9% (56/59) in CP class B and 100% (13/13) in CP class C. The serum albumin level, prothrombin time and ascites were significantly improved (P < 0.01); however, the serum bilirubin level and encephalopathy did not improve. Among patients who achieved SVR12, 75.0% showed an improvement in their CP score, while 5.9% showed a worsening. The presence of large portosystemic shunt (diameter ≥6 mm) and hyperbilirubinemia (≥2.0 mg/dL) were independent factors that interfered with the improvement in the CP score (P < 0.05). The most common AEs were encephalopathy (15.3%) and skin symptoms (7.9%). Two patients discontinued SOF/VEL due to AEs.

CONCLUSIONS

Treatment with SOF/VEL for 12 weeks was relatively safe and effective for patients with decompensated cirrhosis. An SVR provided an improvement of the liver function in the majority of patients. However, large portosystemic shunt and hyperbilirubinemia were independent factors that interfered with the improvement in the CP score.

REACTOR PHYSICS EXPERIMENT IN A GRAPHITE-MODERATION SYSTEM FOR HTGR

The Japan Atomic Energy Agency (JAEA) started the Research and Development (R&D) to improve nuclear prediction techniques for High Temperature Gas-cooled Reactors (HTGRs). The objectives are to introduce a generalized bias factor method to avoid full mock-up experiment for the first commercial HTGR and to introduce reactor noise analysis to High Temperature Engineering Test Reactor (HTTR) experiment to observe sub-criticality. To achieve the objectives, the reactor core of graphite-moderation system named B7/4”G2/8”p8EUNU+3/8”p38EU(1) was newly composed in the B-rack of Kyoto University Critical Assembly (KUCA). The core is composed of the fuel assembly, driver fuel assembly, graphite reflector, and polyethylene reflector. The fuel assembly is composed of enriched uranium plate, natural uranium plate and graphite plates to realize the average fuel enrichment of HTTR and it’s spectrum. However, driver fuel assembly is necessary to achieve the criticality with the small-sized core. The core plays a role of the reference core of the bias factor method, and the reactor noise was measured to develop the noise analysis scheme. In this study, the overview of the criticality experiments is reported. The reactor configuration with graphite moderation system is rare case in the KUCA experiments, and this experiment is expected to contribute not only for an HTGR development but also for other types of a reactor in the graphite moderation system such as a molten salt reactor development.

Efficacy and safety of glecaprevir and pibrentasvir combination therapy in old-aged patients with chronic hepatitis C virus infection

Objective: Combination therapy with glecaprevir and pibrentasvir (G/P) has been shown to provide a sustained virologic response (SVR) rate of >97% in patients with chronic hepatitis C virus (HCV) infection in the first published real-world Japanese data. However, a recently published study showed that the treatment was often discontinued in patients ≥75 years old, resulting in low SVR in intention-to-treat (ITT) analysis. Thus, our aim was to evaluate real-world data for G/P therapy in patients ≥75 years of age, the population density of which is high in “rural” regions.

Patients and Methods: We conducted a multicenter study to assess the efficacy and safety of G/P therapy for chronic HCV infection, in the North Kanto area in Japan.

Results: Of the 308 patients enrolled, 294 (95.5%) completed the treatment according to the protocol. In ITT and per-protocol analyses, the overall SVR12 rate was 97.1% and 99.7%, respectively. The old-aged patients group consisted of 59 participants, 56 of whom (94.9%) completed the scheduled protocol. Although old-aged patients tended to have non-SVR factors such as liver cirrhosis, history of HCC, and prior DAA therapies, the SVR12 rates in old-aged patients were 98.3% and 100% in the ITT and PP analyses, respectively. Of 308 patients enrolled, adverse events were observed in 74 patients (24.0%), with grade ≥3 events in 8 patients (2.6%). There was no significant difference in any grade and grade ≥3 adverse events between the old-aged group and the rest of the study participants. Only one patient discontinued the treatment because of adverse events.

Conclusion: G/P therapy is effective and safe for old-aged patients.

Impact of serum albumin levels on the body fluid response to tolvaptan in chronic kidney disease patients

PURPOSE

Tolvaptan exerts an aquaretic effect by blocking vasopressin V2 receptor. Although tolvaptan ameliorates body fluid retention even in patients with chronic kidney disease (CKD), predictors of body fluid reduction induced by tolvaptan remain unclear. We, therefore, examined the clinical parameters associated with the effect of tolvaptan on fluid volume in CKD patients.

METHODS

Twelve CKD patients (stage 3-5) with fluid retention were treated with tolvaptan in addition to conventional diuretic treatment. Patients were divided into low and high responders by the median change in total body water (TBW) for 1 week measured by a bioimpedance analysis (BIA) device, and clinical parameters were compared between the groups.

RESULTS

The body weight significantly decreased by 2.0 ± 2.3 kg (p = 0.005), but the estimated glomerular filtration rate (eGFR) was not significantly changed (16.9 ± 11.9 vs. 17.4 ± 12.4 mL/min/1.73 m², p = 0.139) after 1 week. The BIA showed that the intracellular water (ICW) decreased by 6.0% ± 4.7% (p < 0.001), the extracellular water (ECW) decreased by 6.7% ± 5.4% (p = 0.001), and the TBW decreased by 6.3% ± 4.9% (median value - 6.02%, p < 0.001). The serum albumin level in the high responders was significantly lower than in the low responders (2.3 ± 0.5 vs. 3.3 ± 0.8 g/dL, p = 0.013). Significant partial correlations adjusted for the eGFR were observed between the baseline serum albumin level and changes in the ICW (r = 0.440, p = 0.048), ECW (r = 0.593, p = 0.009) and TBW (r = 0.520, p = 0.020).

CONCLUSIONS

Serum albumin levels predict the body fluid response to tolvaptan in CKD patients. Tolvaptan may be a promising therapeutic option for ameliorating body fluid retention, especially in patients with hypoalbuminemia.

No Regional Disparities in Sofosbuvir Plus Ribavirin Therapy for HCV Genotype 2 Infection in Tochigi Prefecture and Its Vicinity

Objective Regional disparities were observed in the outcomes of interferon (IFN)-based therapy for chronic hepatitis C virus (HCV) infection in a Japanese nationwide study. However, whether or not these regional disparities are observed in the outcomes of direct-acting antiviral drugs, including sofosbuvir (SOF) plus ribavirin (RBV) therapy, remains unclear. Methods We conducted a multicenter study to assess the efficacy of SOF plus RBV therapy for HCV genotype 2 infection in Tochigi Prefecture and its vicinity, in which IFN-based therapy yielded a low sustained virologic response (SVR) rate. In addition, we divided Tochigi Prefecture into six regions to examine regional disparities in the SVR. Patients We enrolled patients with chronic HCV genotype 2 infection. Results Of the 583 patients enrolled, 569 (97.6%) completed the treatment, and 566 (97.1%) also complied with post-treatment follow-up for 12 weeks. The overall SVR12 rate was 96.1% by per protocol and 93.7% by intention-to-treat analyses. No marked differences were observed in the SVR12 between subjects ≥65 and <65 years of age. Although large gaps were observed in the characteristics of patients and accessibility to medical resources, there was no significant difference in the SVR12 rate among the six regions in Tochigi Prefecture. Conclusion SOF plus RBV therapy was effective for HCV genotype 2 infection in an area where IFN-based therapy had previously shown unsatisfactory results. In addition, no regional disparities in the SVR12 were observed in Tochigi Prefecture.

Structure determination of the rutile-TiO2(110)-(1 × 2) surface using total-reflection high-energy positron diffraction (TRHEPD)

Detailed structure of the rutile-TiO₂(110)-(1 × 2) has been determined using the newly developed technique of total-reflection high-energy positron diffraction (TRHEPD).

Charge-to-Spin Conversion and Spin Diffusion in Bi/Ag Bilayers Observed by Spin-Polarized Positron Beam

Charge-to-spin conversion induced by the Rashba-Edelstein effect was directly observed for the first time in samples with no magnetic layer. A spin-polarized positron beam was used to probe the spin polarization of the outermost surface electrons of Bi/Ag/Al2O3 and Ag/Bi/Al2O3 when charge currents were only associated with the Ag layers. An opposite surface spin polarization was found between Bi/Ag/Al2O3 and Ag/Bi/Al2O3 samples with the application of a charge current in the same direction. The surface spin polarizations of both systems decreased exponentially with the outermost layer thickness, suggesting the occurrence of spin diffusion from the Bi/Ag interface to the outermost surfaces. This work provides a new technique to measure spin diffusion length.

Dietary γ-aminobutyric acid affects the brain protein synthesis rate in young rats

The purpose of this study was to determine whether the gamma-aminobutyric acid (GABA) affects the rate of brain protein synthesis in male rats. Two experiments were done on five or three groups of young rats (5 wk) given the diets containing 20% casein administrated 0 mg, 25 mg, 50 mg, 100 mg or 200 mg/100 g body weight GABA dissolved in saline by oral gavage for 1 day (d) (Experiment 1), and given the diets contained 0%, 0.25% or 0.5% GABA added to the 20% casein diet (Experiment 2) for 10 d. The plasma concentration of growth hormone (GH) was the highest in rats administrated 50 mg and 100 mg/100 g body weight GABA. The concentration of serum GABA increased significantly with the supplementation groups. The fractional (Ks) rates of protein synthesis in brain regions, liver and gastrocnemius muscle increased significantly with the 20% casein + 0.25% GABA diet and still more 20% casein + 0.5% GABA compared with the 20% casein diet. In brain regions, liver and gastrocnemius muscle, the RNA activity [g protein synthesized/(g RNA . d)] significantly correlated with the fractional rate of protein synthesis. The RNA concentration (mg RNA/g protein) was not related to the fractional rate of protein synthesis in any organ. Our results suggest that the treatment of GABA to young male rats are likely to increase the concentrations of plasma GH and the rate of protein synthesis in the brain, and that RNA activity is at least partly related to the fractional rate of brain protein synthesis.

Effect of adding dietary L-lysine, L-threonine and L-methionine to a low gluten diet on urea synthesis in rats

We have shown that urinary urea excretion increased in rats fed a low quality protein. The purpose of present study was to determine whether an addition of dietary limiting amino acids affected urea synthesis in rats fed a low gluten diet. Experiments were done on three groups of rats given diets containing 10% gluten, 10% gluten +0.5% L-lysine or 10% gluten+0.5% L-lysine, 0.2% L-threonine and 0.2% L-methionine for 10 d. The urinary excretion of urea, and the liver concentrations of serine and ornithine decreased with the addition of dietary L-lysine, L-threonine and L-methionine. The fractional and absolute rates of protein synthesis in tissues increased with the treatment of limiting amino acids. The activities of hepatic urea-cycle enzymes was not related to the urea excretion. These results suggest that the addition of limiting amino acids for the low gluten diet controls the protein synthesis in tissues and hepatic ornithine and decline urea synthesis.

Phase transition from asymmetric to symmetric dimer structure on the Si(001) surface at high temperature

The dimer configurations on the Si(001) surface at high temperatures have been investigated using the rocking curve of reflection high-energy electron diffraction. The Si(001) surface shows a displacive phase transition around 900 K, where a well-known asymmetric (tilted) dimer structure on the Si(001) at room temperature transforms to a symmetric dimer structure around 900 K. The metallic feature of the Si(001) surface above 900 K can be explained by the phase transition.

[Minimally invasive direct coronary artery bypass in a patient with idiopathic thrombocytopenic purpura; report of a reoperative case]

A 77-year-old man who had undergone coronary artery bypass grafting (CABG) to segment 3, 7 and 12-14 with saphenous vein grafts (SVG) 15 years before, and ligation of coronary arteriovenous (AV) fistula 8 years before was admitted to our hospital, and diagnosed as acute heart failure and idiopathic thrombocytopenic purpura. Coronary angiography showed multiple stenosis of three vessels, and the grafts to segment 3 and 7 were occluded. The area of left anterior descending (LAD) had no viability, but the inferior wall had viability on dobutamine load echocardiography. The platelet count was about 5.0 x 10(4)/mm3. Minimally invasive direct coronary artery bypass (MIDCAB) for right coronary artery (RCA) using right internal thoracic artery (RITA) was performed through right parasternotomy. Operative and postoperative bleeding was slight, and postoperative course was uneventful. Reoperative MIDCAB can be safely performed in a patient with idiopathic thrombocytopenic purpura, and should be considered a viable alternative for highrisk patients.

Effects of topical latanoprost on optic nerve head circulation in rabbits, monkeys, and humans

PURPOSE

To evaluate the effect of topically administrated latanoprost on optic nerve head (ONH) circulation in Dutch rabbits, cynomolgus monkeys, and normal humans.

METHODS

The ONH tissue blood velocity (NB(ONH)) was determined using the laser speckle method. Latanoprost (0.005%, 30 microl) was instilled into one eye, and vehicle into the other eye as a control. In rabbits, NB(ONH) was measured for 90 minutes after a single instillation and before and after a 7-day once-daily instillation regimen. In monkeys, NB(ONH) was measured before and after 1, 4, and 7 days of a once-daily instillation regimen. The effect of intravenous indomethacin on the latanoprost-induced NB(ONH) change was also studied in rabbits and monkeys. In humans, the time-course changes in NB(ONH) were measured for 4.5 hours before and after a 7-day once-daily instillation regimen. Intraocular pressure (IOP) and systemic parameters were simultaneously studied in each experiment. All measurements were performed by investigators masked to the experimental condition.

RESULTS

Latanoprost significantly increased NB(ONH) 10% to 19% in treated eyes after a single instillation (P = 0.035) or 7-day instillation regimen (P = 0.035) in rabbits, after a 4-day (P = 0.035) or 7-day (P = 0.035) instillation regimen in monkeys, and after a 7-day (P = 0.013) instillation regimen in humans, whereas there were no significant changes in the vehicle-treated eyes in any of the experiments (P > 0.5). Pretreatment with indomethacin (5 mg/kg) abolished the NB(ONH) increase but not the IOP reduction in latanoprost-treated eyes in rabbits and monkeys. IOP remained unchanged in both eyes in rabbits (P > 0.4), whereas it significantly decreased only in latanoprost-treated eyes in monkeys (P < 0.05) and humans (P < 0.05).

CONCLUSIONS

Topical latanoprost significantly increased ONH blood velocity only in treated eyes in rabbits, monkeys, and humans. This effect was independent of the IOP-reducing effect of latanoprost and probably was associated with local penetration of the drug and the production of endogenous prostaglandins.

[Effects of signals on memory and comprehension of history text: insertion of signals that relate the main text with corresponding information in the margins]

History texts for elementary school children have unique discourse structures that involve variety of information and style. This study investigated the effects of signals that relate the main text with corresponding information in the margins on memory and comprehension of the text. One hundred thirty-five undergraduate students were assigned to read the text being divided into two groups: texts with signals, and texts without signals. The text with signals contained four signals, for example, "look at the picture above". After reading the text, subjects recalled the text content (written information only) and took a comprehension test. The result of recall task suggested that students who read the text with signals remembered more information in the margins than those who read the text without signals. In the comprehension test, those in the former group indicated integrated comprehension of the two parts of the text.

New phase and surface melting of Si(111) at high temperature above the (7x7)-(1x1) phase transition

The surface structure of Si(111) at high temperatures (950-1380 degrees C) has been studied with reflection high-energy electron diffraction. We have found three different surface structures: (1) A relaxed bulklike structure with adatoms of 0.25 monolayer (ML) is formed (950-1210 degrees C); (2) there is a new phase where the adatom coverage decreases to 0.20 ML (1250-1270 degrees C); (3) the surface melting occurs over 1290 degrees C. The crystalline structure below the melting layer can be explained by the vacancy model missing all adatoms and 0.45 ML of atoms in the first-double layer.

Clinical experience of a vacuum-assisted nonroller extra-corporeal circulation system

We designed a nonroller extra-corporeal circulation system (NRECC) to minimize space requirements and to improve the safety and ease of cardiopulmonary bypass. The NRECC includes a circuit, a centrifugal pump, and a vacuum regulator. The vacuum regulator has five channels, each of which can control negative pressure independently. Negative pressure is applied to suctions, a vent, and a venous reservoir. Auto Vent-SV and one-way valves were placed between the suctions/vent and the reservoir. The total space required for the NRECC with a heat exchanger was 0.49 m2, which is much smaller than that of our current roller pump system. The maximum volume through the suction/vent was 2.5 L/min at -100 mmHg measured in a simulated system. We used the NRECC for six CABG cases and compared results with those of five CABG cases managed by traditional roller pump extra-corporeal circulation (RECC). The two systems were compared in terms of set-up time and stability/accuracy of the suction/vent. The set-up time of the NRECC (5.3 +/- 1.9 min) was significantly shorter than that of RECC (29 +/- 3.4 min) (p < .01). Stable and accurate blood flow were achieved with the NRECC operating between -15 mmHg and -25 mmHg. In conclusion, NRECC can run a bypass easily and safely and has the benefit of reducing space requirements and shortening set-up time.

Effects of semotiadil, a novel calcium antagonist, on the retina and optic nerve head circulation

The effects of semotiadil, a novel benzothiazine calcium antagonist, on the retinal and optic nerve head (ONH) tissue circulation were evaluated using the noninvasive laser speckle method. In urethane-anesthetized Dutch or albino rabbits, before and up to 90 min following intravenous injection of 400 microg/kg semotiadil fumarate (semotiadil group) or vehicle (control group), normalized blur value, a quantitative index of tissue blood velocity, in the retina (NB(retina)) or ONH (NB(onh)), was serially obtained with monitoring intraocular pressure (IOP) and systemic parameters: arterial pressure, pulse rate, arterial blood gas, and body temperature. There were no significant differences in IOP and the systemic parameters except arterial pressure between semotiadil and control groups during the experiments. Arterial pressure showed an acute and transient drop during the first 5 min after semotiadil administration. The time courses of the normalized blur value were significantly different between semotiadil and control groups in the retina (P = 0.0001, repeated measures two-way ANOVA), but not in the ONH (P = 0.6724). Changes in NB(retina) from the baseline in the semotiadil group was significantly greater than those in the control group 50 min or later after the administration (P < 0.0500, Mann-Whitney test). NB(onh) showed no significant differences between the two groups except during the first few min when arterial pressure acutely decreased in the semotiadil group. In conclusion, intravenously injected semotiadil increased the tissue blood velocity in the retina, but not in the ONH. This vascular selectivity in the ocular neural tissues differs from those of other calcium antagonists, such as nicardipine.

Effect of naloxone on the bladder activity of rabbits with acute spinal injury

BACKGROUND

Naloxone enhances bladder activity in patients with chronic spinal cord injury. However, there are few reports on naloxone for bladder morbidity in acute spinal cord injury.

METHODS

We performed a prospective, controlled study of the effects of naloxone on bladder function in rabbits with and without surgical transection of the spinal cord at the 10th thoracic vertebra. Acute and chronic stages of injury were defined according to bladder function. Naloxone was given intravenously at both stages, and intrathecally at the acute stage. Bladder activity was monitored by cystometry. Blood concentrations of methionine-enkephalin were measured by radioimmunoassay.

RESULTS

Spinal cord injuries were acute 1 or 2 days after surgery, and chronic after 1 or 2 weeks. Bladder capacity significantly decreased after 0.01 mg of intravenous naloxone in uninjured control rabbits, and after 0.03 mg of intravenous naloxone in rabbits with chronic-phase injuries. During the acute-injury phase, 0.3 mg of intravenous naloxone, or 0.02 mg of intrathecal naloxone, was necessary to evoke the micturition reflex. No significant changes in blood enkephalin levels were seen before or after spinal cord injury.

CONCLUSION

In rabbits with acute spinal cord injury, intrathecal naloxone evoked the micturition reflex at a much lower dose than did intravenous naloxone. Intrathecal naloxone promises to become a new therapy for the acute stage of spinal cord injury for active recovery of bladder function, and could replace current therapy.

Combined therapies for composite graft infection after Bentall's procedure

We present a patient who suffered from composite graft infection and mediastinitis. After replacement of the infected composite graft, in addition to administration of antibiotics, continuous irrigation of the mediastinum with solutions containing povidone-iodine and cefazolin sodium and transposition of the greater omentum were performed. His postoperative course was uneventful. Combined therapies including mediastinal irrigation and omental transposition should be considered after an operation for composite graft infection complicated with mediastinitis.

[A case of a successfully treated subclavian aneurysm complicated by a brachiocephalic aneurysm, and the left vertebral artery occlusion]

The patient was a 67-year-old male. Preoperative DSA study revealed a right subclavian aneurysm, a brachiocephalic aneurysm, stenosis of the left common carotid artery and the left subclavian artery, and occlusion of the left vertebral artery. An intraoperative occlusion test of the right vertebral artery showed a decline of the brainstem auditory evoked responses (BAER) seven minutes after the start of the procedure. Cardiopulmonary bypass was established by femoral arterial and bicaval cannulation. Under selective cerebral perfusion by cannulation of both common caroid arteries, a partial aortic arch replacement was performed using a graft patch with 3 branches. These three branches were connected to the right subclavian artery and to both common carotid arteries, respectively. Under deep hypothermia the right vertebral artery was reconstructed with the saphenous vein graft. Proximal anastomosis between the saphenous vein graft and the right caroid graft was done perfusion from a branch of the saphenous vein graft in order to shorten ischemic time of basilar arterial region. The patient was weaned from bypass without problems. After weaning the BAER test was again performed and found to be normal. The postoperative course was uneventful. Postoperative DSA examination showed good blood flow in all the reconstructed vessels. This study suggests that deep hypothermia and shortening of ischemic time of the basilar arterial region are effective in preventing ischemic injury of the brain stem and the cerebellum.

Echocardiographic diagnosis of subepicardial aneurysm ruptured into the right ventricle after inferior myocardial infarction

A subepicardial aneurysm is a rare complication of myocardial infarction that sometimes causes a left to right shunt at the ventricular level. We report on echocardiographic observations in two recent cases of inferior myocardial infarction complicated by rupture of a subepicardial aneurysm into the right ventricle (RV). Two-dimensional and color flow Doppler images in several planes offered diagnostic characteristics of the lesion, including discontinuity of the myocardium at the neck of the aneurysm, a narrow neck relative to the diameter of the aneurysm, and a back and forth flow at the neck of the aneurysm. These techniques also provided new findings, such as a two-chambered structure of the aneurysm and a circular flow pattern within the inner aneurysmal cavity. In addition, color flow Doppler imaging showed multiple shunt flows from the aneurysm to the RV. Echocardiographically diagnosed abnormalities were verified by and successfully treated with surgery in both cases. In conclusion, echocardiography with color flow Doppler imaging may have the potential to diagnose the anatomic and hemodynamic condition of a subepicardial aneurysm.

[Injury to ascending aorta by cross-clamp--histologic evaluation]

To evaluate the injury to ascending aorta by cross-clamp, the trauma to the vessel wall was examined microscopically and the occlusive intensity of the vascular clamp was measured. Six patients were underwent total replacement of the ascending aorta and the aortic arch for aortic dissection. The ascending aorta and the aortic arch were resected during operation, the clamped regions of the ascending aorta were cut into the four pieces (the distal site, two part of the medial site, the proximal site applied by the vascular clamp) after operation. The four pieces of the ascending aorta were examined microscopically. The occlusive intensity of the vascular clamp were measured at the distal site, the medial site, and the proximal site by the load-measuring scale. The trauma to the vessel wall were classified to three degrees (grade 1 to grade 3). Grade 1 showed the minimal changes--narrowing of interstices between collagen fibers and muscle fibers in the media. Grade 2 showed the moderate changes--decrease of collagen fibers, atrophy and disruption of smooth muscle and elastic fiber in the media. Grade 3 showed the severe changes--disruption of the intima and defluvium of endothelial cells. The occlusive intensity of the vascular clamp were 1.0 kg at the distal site, 1.9 kg at the medial site and 3.6 kg at the proximal site, respectively. In the microscopic examinations, grade 1 changes were most frequent at the distal site, grade 1 and grade 2 changes were observed equally at the medial site, grade 3 change was observed only at the proximal site. The degree of the trauma to the vessel wall becomes severer in proportion to increase of the occlusive intensity of the vascular clamp.

Acetylcholine- and flow-induced production and release of nitric oxide in arterial and venous endothelial cells

To study flow-mediated responses in a conduit vein, we investigated the physiological characteristics of endothelium-dependent acetylcholine (ACh)- and flow-induced relaxations using a conventional bioassay cascade. Cylindrical segments isolated from canine common carotid arteries and external jugular veins were perfused at a constant mean flow rate ranging from 1 to 8 ml/min. Endothelium-derived nitric oxide (NO) activity in perfusion effluent through the arterial and venous segments was measured by relaxation of endothelium-denuded arterial rings and arterial and/or venous rings precontracted by prostaglandin F2 alpha, respectively. Stimulation by a flow rate of 8 ml/min on the arterial and venous endothelial cells produced approximately 60 and 20% of the maximum relaxation in the arterial and venous rings, respectively. ACh (10(-6) and 10(-5) M) perfused through the arterial and venous segments with endothelium caused dose-related relaxations of both bioassay rings. The ACh- and flow-induced relaxations were completely reduced by mechanical removal of the endothelial cells. Pretreatment with 5 x 10(-5) M NG-nitro-L-arginine methyl ester (L-NAME) produced a significant reduction of the ACh- and flow-induced vasodilation. Additional treatment with 10(-4) M L-arginine significantly reversed the L-NAME-induced inhibition of ACh-induced relaxation but had no effect on flow-induced relaxation. When the flow rate was increased from 2 to 4 ml/min, the same concentrations of ACh produced larger dose-related relaxations than those obtained at a flow rate of 2 ml/min. Pretreatment with 25 U/ml superoxide dismutase caused no significant effect on the flow-mediated potentiation of ACh-induced relaxation. These findings suggest that venous endothelial cells of canine large vein are able to produce and release NO by stimulation of increased flow or ACh to a significantly lesser extent compared with the artery and that ACh-induced vasodilation is potentiated by an increase in shear stress up to approximately 4 dyn/cm2 loaded on the endothelial cells.

[Relationship between vibratory sense threshold and blood lead concentration in ceramic color workers and transfer printing manufacturers]

We measured vibratory sense thresholds (VSTs) at 63Hz and 125Hz on the third fingertip of the right hand and on the third toe of the right foot of 74 male workers. The subjects were workers engaged in manufacturing ceramic color and transfer printing paper, whose blood lead (Pb-B) levels were 2-58 micrograms/dl. They were divided into three groups according to the Pb-B levels, namely, below 9, 10-19, and 20 micrograms/dl or more. For statistical analysis, simple and partial correlations, and Scheffé's multiple comparison between the least squares means were used. The VSTs on the fingertip as well as on the toe showed a significant correlation with age. The VSTs at 125Hz on the fingertip were also significantly correlated with alcohol consumption and cigarette smoking. Controlling for age, systolic blood pressure, alcohol consumption and smoking habit, a significant dose-effect relationship was observed between the VSTs at not only 63Hz but at 125Hz on the fingertip, and each of the corresponding Pb-B levels. A similar tendency was also observed at the two frequencies on the toe. The measurement of VSTs was considered to be an effective screening test for sensory nerve disorders caused by lead poisoning.

Health status of the workers using mechanized hand tools in an electric parts' maker

The aim was to clarify the relations between the health status of the workers operating mechanized hand tools (MT). MT included electric drivers and air drivers, and the working conditions in an electric parts' maker. Fifty-nine female workers underwent the special examination for vibration hazards, made up of 39 MT operators (Group A) and 20 controls (Group B) who worked without MT at the same plant. The authors made questions about their health and working conditions and physical examinations. The measured items of the peripheral nervous system were the vibratory sensation and sensory nerve conduction velocity (SNCV) in the hand and arm. Those of the musculoskeletal function were pinching power, grasping power, back strength, and tapping ability. The frequency of the complaints "tingling of hands" and "numbness of hands" and "difficulty of finger extension" in Group A was significantly higher than in Group B. The frequency of "swelling of hands" and "heavy feeling of arms" in Group A had a higher tendency than in Group B. There was no difference in the results of physical examinations and vibratory sensation. Pinching power and grasping power (both hands) and back strength in Group A was greater than in Group B. Median SNCV in the hand in Group A was significantly slower than in Group B. The maximum vibration acceleration level (0.56-1.8 m/s2) of the MT used at the plant did not exceed the exposure guideline of ISO. The results suggest that although the vibration level was low enough, physiological changes appeared in the workers with MT.

Determination of 3,4-dimethylhippuric acid as a biological monitoring index for trimethylbenzene exposure in transfer printing workers

The relationship between exposure to 1,2,4-trimethylbenzene (1,2,4-TMB) and urinary concentration of 3,4-dimethylhippuric acid (3,4-DMHA), one of its metabolites, was studied in workers involved in transfer printing. Airborne TMBs were sampled by an organic vapor monitoring badge and analyzed by capillary gas chromatography. Urinary 3,4-DMHA and creatinine were analyzed under the same conditions of high-performance liquid chromatography. The exposure concentration of 1,2,4-TMB among workers was around 25 ppm, the threshold limit value (TLV). The urinary concentration of 3,4-DMHA was low at the start of each shift and high at the end. Exposure to the TLV (25 ppm) of 1,2,4-TMB results in a urinary 3,4-DMHA concentration of 410 mg/g creatinine (r = 0.897, P < 0.001). Urinary 3,4-DMHA concentration could be used as a biological monitoring index for 1,2,4-TMB exposure.

Surgical management of left main coronary artery aneurysm

To date only 7 patients with left main coronary artery aneurysm associated with atherosclerosis have undergone surgical treatment. This report reviews a case of atherosclerotic aneurysm of the left main coronary artery with concurrent stenotic coronary artery disease that was successfully treated by direct approach to the left main coronary artery aneurysm and establishment of coronary artery bypass grafts.

[Lead exposure of workers in the ceramics industry and relevant factors]

To clarify lead exposure and factors relevant to it, an occupational health survey and air lead-concentration survey were conducted among 425 workers in the ceramics industry in the Seto region in Aichi Prefecture. As for biological monitoring, blood lead level was measured according to sex, job, product, factory size and duration of lead exposure. The following major findings were obtained in the present analysis. Workers making dolomite novelties showed higher blood lead levels than those making porcelain novelties, semi-porcelain novelties and tableware. The difference in blood lead level by job was statistically significant, but not that by factory size. In males, the highest blood lead level was found for spray painting work (28.7 micrograms/dl), followed by glazing work (28.0 micrograms/dl), kiln work (23.3 micrograms/dl) and painting work (22.3 micrograms/dl). In females, the blood lead level for painting work (13.5 micrograms/dl) was lower than those for glazing work (26.1 micrograms/dl) and kiln work (31.4 micrograms/dl). The blood lead level was significantly increased with the number of years of lead exposure in females (painting work). It was coincidentally clarified that the environmental lead concentration varied according to the job in which workers were engaged. As protective measures against lead exposure for workers in the ceramics industry, the development of nonlead paint and glaze and the introduction of more effective dust collectors at the workplace should be established.

Isolated pulmonary valve endocarditis without cardiac anomaly in an infant

A patient with isolated pulmonary valve infective endocarditis without congenital heart disease was diagnosed at an early stage. Simple valvulectomy without replacement was successfully performed during the active stage of infection.

[Experimental study on the hydrodynamic performance of "valved pericardial roll"]

Optimal configuration and hydrodynamic performance of "Valved Pericardial Roll (VPR)" as an external conduit was studied using a mock circulatory system which was able to simulate a right cardiac function of infants. Results were as follows: 1) Cardiac output produced by VPR was consistently higher than that by non valved pericardial roll. This result showed the hemodynamic effectiveness of VPR at early stage of operation. 2) Cardiac output by VPR tended to decreased as an elevation of afterload and/or an increment of pulse rate. This result exhibited that VPR had a comparable performance to the Ionescu-Sihley pericardial valve, a satisfactory performance of which was recognized clinically. 3) The optimal configuration related to the length of valve leaflet (LVL) were obtained from the simulation data. VPR with two leaflets produced the best performance when each LVL was design to be 95% of the roll diameter. Among the VPR with three leaflets, the best LVL was 85%. Thus far, VPR which was developed based on the above fundamental studies, indicated satisfactory performance as compared to the conventional surgical treatment.

Relations between lead exposure and peripheral neuromuscular functions of lead-exposed workers--results of tapping test

In this study, four experiments using the tapping test were conducted to evaluate the possible subclinical effects of lead exposure on the neuromuscular systems of lead workers at some transfer printing factories in Japan. Decreases in the tapping ability appeared coincidentally with higher blood lead levels. The recovery of the tapping ability after 30 sec rest in the groups of 30-45 micrograms/dl and above 45 micrograms/dl PbB was worse than that in the group with less than 29 micrograms/dl PbB. The recovery of the decreased tapping ability after 60 sec rest was better even in the group with 30-45 micrograms/dl PbB. The tapping ability for 0-10 sec at the first tapping test was sustained after 30 or 60 sec rest in the group with the PbB below 29 micrograms/dl; however, the tapping ability at the second and third tapping test decreased in the two groups with the PbB level above 30 micrograms/dl. The decreased finger tapping speed may be functional evidence of low-grade motor neuropathy among the workers with higher levels of lead absorption.

Improvement of cardiac function impaired by repeated ischemic arrests in isolated rat hearts

We investigated the effects of coenzyme Q10 and verapamil, either alone or in combination, on cardiac function impaired by repeated ischemic arrests and reperfusion in the isolated rat heart. In the group with a single ischemic arrest, the aortic flow, cardiac output, stroke volume, coronary flow, and heart rate recovered well (72% to 100% of the prearrest values). In the repeated-arrest group, the recovery of aortic flow (24%), cardiac output (30%), stroke volume (40%), or coronary flow (63%) was much poorer than that in the single-arrest group. Pretreatment with coenzyme Q10 given intraperitoneally improved aortic flow, cardiac output, stroke volume, coronary flow, and heart rate. The addition of verapamil to the reperfusion solution also protected the cardiac function with a decrease in heart rate. However, combination therapy with coenzyme Q10 and verapamil further increased the recoveries of aortic flow, cardiac output, stroke volume, and coronary flow to 57%, 61%, 77%, and 84%, respectively, which were better than the values after treatment with coenzyme Q10 or verapamil alone. We, therefore, suggest that treatment with coenzyme Q10 or verapamil, alone or in combination, in addition to St. Thomas' Hospital solution effectively protects cardiac function impaired by repeated ischemic arrests and reperfusion.

Recording the bladder electromyogram for bladder activity evaluation during post-operative urinary urgency

When the intravesical pressure cannot be measured because of continuous drainage, bladder electromyography is an alternative means of evaluating the functional condition of the urinary bladder. However, many problems that accompany this procedure have not been solved. In the present study we tried bladder electromyography with a newly-developed carbon fiber electrode in a patient who underwent an open prostatectomy. It was helpful in recognizing the relationship between urinary urgency and the spasmic activity of the vesicular detrusor muscle.

[The surgical treatment for the Stanford type A aortic dissection]

Twenty-nine patients who underwent operation at Shinshu University Hospital for the Stanford type A dissecting aneurysm were analysed. The patients were operated on in the acute stage within 2 weeks after onset. In 13 of these 26 acute cases, the graft replacement of the ascending and arch of the aorta was performed (group A). The patients were operated under a separate perfusion to the brain and the distal anastomosis to the proximal portion of the descending aorta was performed using the method of open distal anastomosis. In other 13 cases, the graft replacement of the ascending aorta was performed (group B). Operative mortality rate was 19% in this series (group A: 23%, group B: 15%). There was no significant difference in their operative mortality of acute stage. And there was also no significant difference in their post operative course of acute stage operations. We concluded that the graft replacement of the ascending and arch of the aorta was better than the graft replacement of the ascending aorta alone for the patients with Stanford type A acute aortic dissection.

[A case of aortic valve stenosis and regurgitation with idiopathic thrombocytopenic purpura]

A patient of aortic valvular disease with idiopathic thrombocytopenic purpura underwent aortic valvular replacement. We report a preventive measure against the intra and postoperative bleeding. The patient was a 67-year-old man. He was diagnosed as aortic valvular stenosis with regurgitation. There was no abnormal data about the coagulation test. Thrombocyte count was 8.2 x 10(4)/mm3, but thrombocytopenic life span had shortened 3.8 days. So, we used gamma-globulin 400 mg/kg/day for 5 days before the day of operation and infused blood platelets on the day of operation. There was no problem intra and postoperative period. On the 14th postoperative day thrombocyte count increased to 22.9 x 10(4)/mm3, and thrombocytopenic life span returned to normal range (7.6 days). But on the 45th day of postoperation, thrombocyte count decreased to 11.0 x 10(4)/mm3. We think that many gamma-globulin medication is a useful method to prevent intra and postoperative bleeding resulting from idiopathic thrombocytopenic purpura.

Improved patency of an elastomeric vascular graft by hybridization

A newly devised hybrid graft with high antithrombogenicity for small caliber vascular grafts was developed. The design concept was based on the incorporation of a compliant open cell structured graft, autogenous endothelial cells (ECs), and artificial basement membrane. The latter, a gel complex of type I collagen and dermatan sulfate that showed enhanced adhesion and growth of ECs but reduced platelet adhesion, was coated onto a microporous polyurethane graft (internal diameter, 3 mm; length, 4.5 cm), with near-natural compliance. Ten seeded grafts were implanted bilaterally into the carotid arteries of dogs; anticoagulant or antiplatelet therapy was not administered. This hybrid graft showed a marked improvement in patency at 1 month compared with that of simply preclotted grafts (control specimens). This result was explained by the almost complete endothelialization when the graft was implanted, a high degree of adherent strength resistance to shear stress, and a high proliferative potential. Thus, this approach of combining biomechanical and cellular engineering designs may lead to an important functional small caliber graft.