Reduced coronary flow reserve in familial hypercholesterolemia

Familial hypercholesterolemia (FH) presents the highest risk for coronary artery disease (CAD) among patients with hyperlipidemia. Therefore, early detection of coronary arterial atherosclerosis is important for the treatment of FH patients. The aim of this study was to detect early coronary arterial abnormalities that may relate to future atherosclerosis in asymptomatic FH patients by measuring coronary flow reserve (CFR) using PET and 13N-ammonia.

METHODS

Twenty-five patients with FH (14 men, 11 women) without a history of myocardial ischemia and 14 control subjects (9 men, 5 women) were studied. Total serum cholesterol (mmole/liter) was 5.33 +/- 0.66 in control subjects and 7.90 +/- 0.77 in FH patients (p < 0.01 versus control subjects).

RESULTS

Myocardial blood flow (MBF) at rest and during dipyridamole loading was measured using PET, and CFR was calculated. MBF (ml/min/100 g weight heart) at rest in the FH group (79.0 +/- 20.0) was comparable to that in control subjects (70.0 +/- 17.0). However, MBF during dipyridamole loading was significantly lower in FH patients (163.0 +/- 67.0) than in control subjects (286.0 +/- 120.0, p < 0.01). CFR in FH patients (2.09 +/- 0.62) was also significantly lower than that in control subjects (4.13 +/- 1.38, p < 0.01). CFR showed a gender-specific variance in FH patients (1.85 +/- 0.40 in men versus 2.55 +/- 0.74 in women p < 0.05) but not in control subjects. Significant inverse correlations between CFR and the total plasma cholesterol level as well as plasma LDL cholesterol were observed.

CONCLUSION

The CFR was reduced in patients with FH. This abnormality was more prominent in men than in women patients. Noninvasive assessment of CFR by 13N-ammonia PET was useful to detect early abnormalities of the coronary arteries in asymptomatic patients with FH.

Increase in hepatic tissue blood flow by teprenone

The major objective of the present study was to evaluate mechanisms by which teprenone, a gastric mucosal protecting agent, increases hepatic mucosal blood flow using male Sprague-Dawley rats. Hepatic and gastric blood flow was measured using a laser blood flow meter after administration of teprenone, dissolved in Tween 80, into the inferior vena cava. Teprenone itself increased hepatic and gastric blood flow. It also increased hepatic and gastric blood flow in rats with acute hepatic disorders due to carbon tetrachloride (CCL4) and improved histological changes, such as inflammatory cell infiltration and fatty changes in the liver. The fact that blood endothelin (ET) concentrations increased after administration of teprenone suggest that teprenone has great affinity for ET beta receptors and shows ET beta-receptor antagonist-like effects. Hepatic blood flow decreased after administration of N-nitro-L-arginine methyl ester, a nitric oxide (NO) synthetase inhibitor, suggesting that teprenone increase NO activity. Teprenone was thought to increase hepatic and gastric blood flow by different mechanisms, because it increased gastric mucosal prostaglandin E2 concentrations.

Malignant lymphoma of the gastric stump developing 25 years after a distal gastrectomy for benign gastric disease: report of a case

We report herein the case of a 57-year-old man in whom malignant lymphoma originating in the gastric remnant was confirmed 25 years after a subtotal gastrectomy with Billroth II reconstruction had been performed for gastric ptosis. Gastroscopy revealed an ulcerated tumor on the fornix, and histologic examination of the endoscopic biopsy specimens demonstrated malignant lymphoma. Thus, total gastrectomy with splenectomy, pancreatectomy, and resection of the previously anastomosed jejunal stoma were performed. Histologic examination of the stomach remnant confirmed a diagnosis of B-cell lymphoma of the large-cell type. Although we were unable to study the surgical specimen from the initial operation, the possible relationship between pseudolymphoma and malignant lymphoma has been presented in the literature, which is reviewed following this case report.

Role of Fc fragments in inhibition of xenogenic hyperacute rejection by intravenous immunoglobulin

It has been shown that a high dose administration of human intravenous immunoglobulin G (IVIG) prolonged the survival time of xenografted guinea pig heart in the rat. In this study, we compared the effectiveness of intact IVIG (I-IVIG), Fc fragments of IVIG (Fc-IVIG), and F(ab') fragments of IVIG (Fab-IVIG) in preventing xenogenic hyperacute rejection in the guinea pig-to-rat heart transplantation model. Relatively high dose administration of IVIG (0.6 g/kg body weight) induced xenograft survival times of 32.0 +/- 13.0 min and 33.2 +/- 16.8 min with I-IVIG and Fab-IVIG, respectively, which were significantly longer than times for animals treated with Fc-IVIG or for untreated control animals (survival times of 12.6 +/- 7.4 min and 10.4 +/- 7.6 min, respectively). The in vitro inhibitory effect of guinea pig red blood cell hemolysis by fresh rat serum correlated with the results of in vivo study. On the other hand, the in vitro inhibitory effect of IVIG on pig red blood cell hemolysis by fresh human serum showed that Fc-IVIG, which had little effect in the guinea pit-to-rat combination, had a higher inhibitory effect than Fab-IVIG, or I-IVIG. Fc-IVIG and I-IVIG achieved a complete inhibition of in vitro hemolysis in the pig-to-human combination. It is suspected that an interference with the complement classical pathway by the Fc portion of IVIG could be an attractive tool for inhibition of hyperacute rejection in the pig-to-human combination.

Simple method to quantify myocardial glucose metabolism from MB ratio in myocardial FDG PET

To provide a simple means of quantifying myocardial glucose metabolism, we tried to estimate the K complex (KC) from the myocardium to background ratio (MB ratio), which was obtained with a single static FDG scan and single venous sampling. In 48 fasting subjects and 74 subjects under oral glucose loading or insulin clamp, the reference KC was obtained from Patlak analysis by using an input function. We compared the reference KC with the MB ratio at 35 min 45 sec, 45 min 45 sec, and 55 min 45 sec, and with the FDG uptake index (FUI) reported by Tamaki. The correlation between KC and each index was very close during fasting (r = 0.97, 0.98, 0.98 and 0.97, respectively n = 48), and clinically acceptable during oral glucose loading and insulin clamp (r = 0.92, 0.91, 0.90 and 0.93, respectively n = 74). The average differences between the reference KC and KC estimated from the simple method were 13%, 10%, 8%, and 13%, respectively, during fasting, and 15%, 14%, and 16%, respectively, during oral glucose loading and insulin clamp. Both the MB ratio and FDG uptake index can be used for the simple estimation of myocardial glucose metabolism not only during fasting but also during oral glucose loading and insulin clamp, although the MB ratios at 45 min and at 55 min were slightly better than MB that at 35 min and the FDG uptake index during fasting.

Measurement of metallothionein in rat tissues by a chromatographic method using the fluorometry of thiol groups

The estimation of metallothionein (MT) levels in a biological sample is required to study the physiological role or the induction of MT, which is a multifunctional protein. MT contains 61 amino acids with 20 homologous cysteines. The high selectivity, sensitivity and stability of N-[4-(dimethylamino-2-benzofuranyl)phenyl]maleimide (DBPM) for the determination of SH groups was very useful for the determination of MT. The detection limit of MT by this method was 10 ng/0.5 ml. This method made it possible to measure MT levels in normal tissues in combination with gel filtration chromatography. The age-dependent change in MT levels in normal rat tissues was also investigated by the present method. MT levels in normal rat tissues vary with age. It is thought that this fact is correlated with the biological roles of MT.

Liver transplantation and hepatocellular carcinoma

Liver transplantation for advanced hepatocellular carcinoma (HCC) continues to be a subject of debate mostly due to a uniformly high failure rate secondary to recurrence. However, accumulating experiences have enabled detailed analysis of the prognostic factors affecting patient outcome. Clinicopathological factors affecting survival have been reported to include tumor size, number, lobar distribution, vascular invasion, lymphnode metastasis, and histologic type such as fibrolamellar variant of HCC. Poor prognosis has been associated with advanced stage of the tumor, particularly pTNM stage IV. Many transplant centers now use a protocol of adjuvant chemotherapy with reasonable success, although experiences are limited. Better understanding in tumor biology, particularly of the role of immunosuppression affecting tumor growth, will provide further success in the treatment of HCC by liver transplantation.

Inhibitory effect of double transfection to xenoendothelial cells using both decay accelerating factor and homologous restriction factor 20 genes on complement dependent cytolysis

Hyperacute rejection in discordant xenotransplantation occurs due to the complement activation via classical and/or alternative pathway. Regulator of complement activation (RCA) molecules inhibit species-specific complement dependent cytolysis. To confirm the effect of gene engineering using double RCA molecules on xenogeneic cells, the inhibitory effect on complement dependent cytolysis was compared between bovine aortic endothelial cells (BAEC) doubly transfected with both decay accelerating factor (DAF) and homologous restriction factor (HRF) 20 cDNA and BAEC singly transfected with DAF alone using retroviral vector. The positive percent expression of DAF and HRF20 antigen on double transfectant (BAEC/D+H) was 97.0% and 95.0%, respectively, whereas that of DAF antigen on single transfectant (BAEC/D) was 97.0%. After incubated with 25% human serum and anti-BAEC antibody, the viability of double transfectant (BAEC/ D+H) was significantly preserved, compared with that of single transfectant (BAEC/D). These findings demonstrated that xenoendothelial cells doubly transfected with both DAF and HRF20 cDNA could be protected from complement dependent cytolysis more effectively than those singly transfected with DAF alone in the presence of antixenoendothelial antibody.

Factors affecting graft function in cadaveric renal transplantation from non-heart-beating donors using a double balloon catheter

Experiences in 145 cadaveric kidney transplantation from non-heart-beating donors showed that not only donor age and WIT but also recipient body weight and duration of hemodialysis dependency were the determining factors affecting posttransplant kidney function analyzed with the use of a stepwise logistic regression model. This suggests that the fluid burden on the graft provides an additional insult on the recovery of the grafts from ischemic injury.

Human superoxide dismutase cDNA transfection and its in vitro effect on cold preservation

In order to elucidate the role of superoxide dismutase (SOD on ischemia-reperfusion injury, bovine and porcine aortic endothelial cells were transfected with retroviral vector LSODRNL containing human Cu,Zn-SOD cDNA and their SOD activities were evaluated by measuring superoxide scavenging capability. Successful augmentation of Cu,Zn-SOD up to 2.7-fold in bovine and 1.9-fold in porcine cells was obtained. After 24 h cold preservation followed by 4 h rewarming, cell viability compared with that of pre-preservation was significantly increased in both types of cells (P < 0.01). Moreover, after exposure to superoxide, viability of the porcine cells with high SOD activity was significantly improved compared to control cells. We consider that transfection of human Cu,Zn-SOD cDNA to arterial endothelial cells is useful for preventing from cold preservation-rewarming or ischemia-reperfusion injury.