Intracellular alkalinization augments platelet aggregation due to increase in cytosolic free-Ca2+

Intracellular pH is known to increase during agonist-induced platelet activation. In order to elucidate the role of intracellular alkalinization in platelet activation, the effects of NH4Cl, as a tool to induce intracellular alkalinization, on ionomycin-induced platelet activation were investigated. NH4Cl (2.5-10 mM) concentration-dependently induced intracellular alkalinization. Platelet aggregation induced by ionomycin (0.1 microM) was augmented by treatment with NH4Cl (2.5-10 mM). Ionomycin-induced platelet aggregation in the absence of extraplatelet Ca2+, which was markedly attenuated compared to that in the presence of extraplatelet Ca2+, was also augmented by NH4Cl. NH4Cl treatment increased the number of large aggregates after ionomycin stimulation, while it decreased the number of small aggregates. Both transplasmalemmal Ca2+ entry and intracellular Ca2+ release induced by ionomycin were increased by treatment with NH4Cl (10 mM). SKF-96365 (100 microM), an inhibitor of receptor-operated Ca2+ channels, did not affect ionomycin-induced Ca2+ entry but abolished the effect of NH4Cl on Ca2+ entry. Thus, NH4Cl augments receptor-operated Ca2+ channels and intracellular Ca2+ release. These findings suggest that intracellular alkalinization plays a significant role in agonist-induced platelet activation.     

Gore-Tex jump graft for portal vein thrombosis following living donor liver transplantation

Portal vein thrombosis is a rare surgical complication following liver transplantation, which remains a cause of graft loss and death. We describe here the treatment of portal vein thrombosis following living donor liver transplantation using an extended left lobe graft. The patient was treated with a Gore-Tex vascular jump graft extra-anatomically interposed between the recipient superior mesenteric vein and the donor umbilical vein. This technique allowed the hepatic hilum to be left untouched and supplied suitable blood flow to the hepatic allograft. Our experience suggests that this innovative technical solution can be helpful in the effort to rescue cases of hepatic allograft with vascular complications.     

The utility of intra‐operative three‐dimensional transoesophageal echocardiography for dynamic measurement of stroke volume

Measurement of left ventricular stroke volume and cardiac output is very important for managing haemodynamically unstable or critically ill patients. The aims of this study were to compare stroke volume measured by three‐dimensional transoesophageal echocardiography with stroke volume measured using a pulmonary artery catheter, and to examine the ability of three‐dimensional transoesophageal echocardiography to track stroke volume changes induced by haemodynamic interventions. This study included 40 cardiac surgery patients. Haemodynamic variables were measured before and 2 min after haemodynamic interventions, which consisted of phenylephrine 100 μg or ephedrine 5 mg. We used Bland–Altman analysis to assess the agreement between the stroke volume measured by three‐dimensional transoesophageal echocardiography and by the pulmonary artery catheter. Polar‐plot and 4‐quadrant plot analyses were used to assess the trending ability of three‐dimensional transoesophageal echocardiography compared with the pulmonary artery catheter. Bias and percentage error were ?1.2 ml and 20%, respectively. The concordance rate in the 4‐quadrant analysis after phenylephrine and ephedrine administration was 75% and 84%, respectively. In the polar‐plot analysis, the angular concordance rate was 66% and 73% after phenylephrine and ephedrine administration, respectively. Three‐dimensional transoesophageal echocardiography was clinically acceptable for measuring stroke volume; however, it was not sufficiently reliable for tracking stroke volume changes after haemodynamic interventions.     

Clinical outcomes of a novel therapeutic vaccine with Tax peptide‐pulsed dendritic cells for adult T cell leukaemia/lymphoma in a pilot study

Adult T cell leukaemia/lymphoma (ATL) is a human T cell leukaemia virus type‐I (HTLV‐I)‐infected T cell malignancy with poor prognosis. We herein developed a novel therapeutic vaccine designed to augment an HTLV‐I Tax‐specific cytotoxic T lymphocyte (CTL) response that has been implicated in anti‐ATL effects, and conducted a pilot study to investigate its safety and efficacy. Three previously treated ATL patients, classified as intermediate‐ to high‐risk, were subcutaneously administered with the vaccine, consisting of autologous dendritic cells (DCs) pulsed with Tax peptides corresponding to the CTL epitopes. In all patients, the performance status improved after vaccination without severe adverse events, and Tax‐specific CTL responses were observed with peaks at 16–20 weeks. Two patients achieved partial remission in the first 8 weeks, one of whom later achieved complete remission, maintaining their remission status without any additional chemotherapy 24 and 19 months after vaccination, respectively. The third patient, whose tumour cells lacked the ability to express Tax at biopsy, obtained stable disease in the first 8 weeks and later developed slowly progressive disease although additional therapy was not required for 14 months. The clinical outcomes of this pilot study indicate that the Tax peptide‐pulsed DC vaccine is a safe and promising immunotherapy for ATL.     

Association of interleukin-10 promoter single nucleotide polymorphisms -819 T/C and -592 A/C with aging

Increased inflammatory activity is known to accompany aging. Single nucleotide polymorphisms of inflammatory mediator genes might therefore affect the aging process. Relation of eight SNPs (tumor necrosis factor-alpha [TNF-alpha] -1031 T/C, interleukin-10 [IL-10] -819 T/C, IL-1beta -511 C/T, IL-6 -634 C/G, IL-18 -607 A/C, transforming growth factor-beta [TGF-beta] +869 C/T, matrix metalloproteinase-1 [MMP-1] -1607 1G/2G, and MMP-3 -1171 5A/6A) with age or gender was evaluated in 500 Japanese persons (mean age: 56.7 years old, range: 19-100) by the chi-square test. There was a significant association of IL-10 -819 T/C with age (p =.0026). The association remained significant after multivariate logistic regression analysis (odds ratio for an age interval for 1 year, 1.009; 95% CI, 1.002-1.016). Furthermore, the genotype distribution of IL-10 -819 T/C was completely consistent with that of -592 A/C. These data suggest that IL-10 -819 T/C and -592 A/C may be a promising candidate for an aging-related gene in a Japanese population.     

Doppel induces degeneration of cerebellar Purkinje cells independently of Bax

Doppel (Dpl) is a prion protein paralog that causes neurodegeneration when expressed ectopically in the brain. To investigate the cellular mechanism underlying this effect, we analyzed Dpl-expressing transgenic mice in which the gene for the proapoptotic protein Bax had been deleted. We found that Bax deletion does not alter either clinical symptoms or Purkinje cell degeneration in Dpl transgenic mice. In addition, we observed that degenerating Purkinje cells in these animals do not display DNA fragmentation or caspase-3 activation. Our results suggest that non-Bax-dependent pathways mediate the toxic effects of Dpl in Purkinje cells, highlighting a possible role for nonapoptotic mechanisms in the death of these neurons.     

Bilateral video-assisted thoracoscopic surgery in the supine position for primary spontaneous pneumothorax

On the basis of the bilateral nature of bullous lesions of the lung, the authors have performed single-stage bilateral video-assisted thoracoscopic surgery (VATS) in the supine position for primary spontaneous pneumothorax in five patients since October 1999. All five patients were males with a mean age of 23 years (range 19 to 29 years). The presenting pneumothorax was ipsilateral (right-sided) in four patients and simultaneous bilateral in the one remaining patient. Apart from the one case of simultaneous bilateral spontaneous pneumothorax (SBSP), all patients had a history of at least one pneumothorax episode requiring tube thoracotomy. Bilateral bullae were confirmed in all patients on preoperative chest computed tomography (CT). Bilateral bullectomy was performed by endo-stapler with no difficulties. Mean operating time was 111 minutes (range 85 to 140 minutes). All patients were returned to the surgical ward in good condition from the operating room immediately after extubation. No complications were observed, and duration of postoperative hospital stay was two to four days. All patients were alive without recurrence of pneumothorax after a mean follow-up period of 25 months (range, 9 to 43 months). Single-stage bilateral VATS in the supine position has shown itself to be an excellent approach for the treatment of bilateral bullous lesions, combining both efficacy and low morbidity.     

Relationships between polymorphisms of the human serum paraoxonase gene and insulin sensitivity in Japanese patients with type 2 diabetes

Human serum paraoxonase (PON1), which is associated with HDL, is an esterase and has been shown to reduce the susceptibility of LDL to lipid peroxidation. The objective of the study was to determine whether genetic polymorphisms of the PON1 gene are associated with insulin sensitivity. Forty-eight Japanese patients with type 2 diabetes were recruited, and euglycemic hyperinsulinemic clamp was performed to assess insulin sensitivity. The PON1 promoter polymorphism C(-108)T was determined by direct sequencing, and the coding region polymorphism Q192R was determined by polymerase chain reaction and digestion of the amplified fragments. No association was observed between the Q192R polymorphism and the glucose infusion rate (GIR), whereas GIR increased with the following order of genotypes: -108TT < -108CT < and -108CC (4.2+/-1.6, 5.1+/-2.5, and 6.9+/-2.5 mg kg(-1) min(-1), respectively; P<0.02, ANCOVA). Stepwise regression analysis revealed that the C(-108)T polymorphism significantly contributed to the GIR. It has been reported that oxidative stress attenuates insulin signaling in vitro. The PON1 promoter polymorphism C(-108)T may influence insulin sensitivity by modulating serum antioxidant capacity.