New mechanism to reduce the size of the monopivot magnetic suspension blood pump: direct drive mechanism

Size reduction of the monopivot magnetic suspension blood pump has been achieved by reducing the size of the magnetic suspension and employing a direct drive mechanism in place of a brushless DC motor and a magnetic coupling. The flow has also been improved using a closed hollow impeller to remove flow obstruction at the inlet and using radial straight vanes to reduce the impeller speed by 30%. Hemolysis testing was conducted for the new models. Results showed that model DD1 presented only a slightly higher level of hemolysis than a regular extracorporeal centrifugal pump.

Importance of intra-abdominal visceral fat accumulation to coronary atherosclerosis in heterozygous familial hypercholesterolaemia

OBJECTIVES

Hyper-low-density lipoprotein (LDL)-cholesterolaemia is a potent risk factor for coronary atherosclerosis. We have recently demonstrated that a cluster of risk factors including insulin resistance, glucose intolerance, hypertriglyceridaemia, and hypertension based on intra-abdominal visceral fat accumulation are closely related to coronary artery disease. In the current study, we evaluated the relationship between visceral fat accumulation and the severity and distribution of coronary atherosclerosis in familial hypercholesterolaemia (FH).

DESIGN

The effect of visceral fat accumulation on coronary lesions and risk factors in patients with FH was investigated.

SUBJECTS

Thirty-one male patients with heterozygous FH who underwent coronary angiography.

MEASUREMENTS

Abdominal fat distribution was estimated by a cross-sectional computed tomographic scan at the umbilical level. Plasma lipid, glucose and insulin concentrations and blood pressure were measured. A 75 g oral glucose tolerance test was also performed.

RESULTS

The patients were divided into two groups according to the degree of visceral fat accumulation. Fifteen patients had high visceral fat accumulation (High VF group) and 16 patients had normal visceral fat accumulation (Normal VF group). Body mass index (BMI) and subcutaneous fat area were significantly higher in the high VF group. Baseline serum triglyceride was significantly higher and baseline low-density lipoprotein (LDL)-cholesterol and reduction of LDL-cholesterol during treatment were significantly lower in High VF group. Fasting plasma glucose and insulin concentrations, and systolic and diastolic pressures were significantly higher in the High VF group. Significant correlations were found between visceral fat area and the sum of the glucose and insulin concentration during an oral glucose tolerance test. Visceral fat area was significantly correlated with the severity of coronary stenosis index. Distal coronary lesions were significantly more frequent in the High VF group. Moreover, the correlation between the visceral fat area and coronary stenosis index was found to be independent of age, BMI, and subcutaneous fat area by multiple regression analysis.

CONCLUSIONS

Visceral fat accumulation is a potent cardiovascular risk factor in heterozygous FH.

Using acoustic radiation force as a concentration method for erythrocytes

We investigated the potential damage inflicted on erythrocytes by acoustic radiation force when the cells are concentrated by a 500-kHz ultrasonic standing wave at the pressure node. The extent of the damage was estimated from the concentrations of potassium ions, iron complexes, and lactate dehydrogenase released from the cells. After 2 min of ultrasound irradiation at 12.8 mJ/m3, the cells concentrated on the pressure node, with a cell distribution half-width of 138 microns; no significant release of intracellular components was detected, even after 15 min of irradiation. The results indicate that even small ions like potassium are not released as a result of ultrasound irradiation on cell membranes without cavitation, and they demonstrate the potential use of acoustic radiation force for concentrating living cells in biomedical applications.

Detection of interleukin 6-producing cells among various organs in normal mice with an improved enzyme-linked immunospot (ELISPOT) assay

The enzyme-linked immunospot (ELISPOT) assay is an efficient technique for the enumeration of single cells secreting antibodies or cytokines. To assess mice interleukin 6 (IL-6)-secreting cells at a single cell level, a highly sensitive ELISPOT assay with 5-bromo-4-chloro-3-indolylphosphate p-toluidine salt and nitroblue tetrazolium chloride (BCIP/NBT) as a gel-substrate has been developed. The IL-6 specific ELISPOT assay thus developed with an ordinary plastic ELISA plate is as efficient as the previous IL-6 specific ELISPOT assay system which uses a nitrocellulose coated plate, and is much more economic and convenient. We demonstrated with this newly devised ELISPOT assay that the ratio of IL-6 producing cells in the resident peritoneal exuded cells was highest in normal BALB/c mice, and a few IL-6 secreting cells were detected in all organs we tested, namely the spleen, bone marrow, Peyer's patch, axillary lymph node and thymus.

Effects of preconditioning with ebselen on glutathione metabolism and stress protein expression

Selenium induces several proteins, including glutathione and stress proteins. These proteins have been shown to be cardioprotective against oxidative injury. To determine whether ebselen, a seleno-organic compound, can also induce these proteins and exert cardioprotective action, we examined the effects of preconditioning with ebselen on glutathione metabolism and stress protein expression and on myocyte injury induced by oxidative stress. Treatment of cultured cardiac myocytes with ebselen (0.3-30 microM) for 24 hr increased the reduced glutathione content. Glutathione reductase activity, but not glutathione peroxidase activity, was significantly elevated in a dose-dependent manner. Pretreatment with ebselen increased the expression of such stress proteins as heat shock protein 70 and heme oxygenase-1 (heat shock protein 32) in cardiac myocytes, as assessed by Western blotting. Expression of heat shock protein 70 was increased only at a higher dose of ebselen (30 microM), whereas expression of heme oxygenase-1 was markedly increased at a lower dose of ebselen (3 microM). Under these conditions, the myocyte injury induced by hydrogen peroxide or simulated ischemia/reperfusion, assessed by the release of lactate dehydrogenase into the culture medium, was reduced by ebselen pretreatment in a dose-dependent manner. Results indicated that cardiac myocytes pharmacologically preconditioned with ebselen for 24 hr exhibited resistance to oxidative injury, possibly via the up-regulation of glutathione metabolism and the expression of stress proteins.

[Simplification of on-line connection of analyzers and standardization problems]

On-line connection of automated analyzers to laboratory information system (LIS) reduces mistakes in inputing data for each samples. It also makes reporting faster in clinical laboratory. Moreover, connection of these instruments with sample transporting system enables analyses without touching samples directly. It, however, costs extremely high to construct such a system. It is because every automated analyzer uses different connecting protocol, so that we have to make a different program for each machine. For solving this problem, we have to make a standard for connecting protocol. It is very difficult to make a standard protocol fitting on all of the analyzers, considering its cost and other things. Furthermore, it must take a few decades to spreading the standard through the end users. ICCLS and NCCLS has been taking a central role for this problem since 1996, with a five-year plan to make an international standard. Until the standard will be laid, each clinical laboratories have to pay high costs to construct their systems, connecting different manufacturers' analyzers each other. Thus, we have developed a novel system which enables us to construct a laboratory automation system in a shorter time. For realizing this new system, we have reduced the number of connecting protocols for analyzers. Moreover, we have corrected the flow of laboratory works in order. Each programs are put together into a system as parts, or modules. This software system is now in operation in the clinical laboratory of Kochi Medical School. In this report, we describe the construction of this novel software system, and the effect obtained by using this system. Furthermore, we would show problems and things to be improved for making international standards for communication protocols between host and analyzing instruments.

[Study of diarrhea-inducing strains of Escherichia coli mainly isolated in Kanto area between June and September 1996]

A total of 21,609 faecal specimens obtained from patients with diarrhea mainly in Kanto area between June and September 1996 were investigated to identify the causative pathogens for diarrhea. One-hundred fifty-seven strains of Escherichia coli of 29 different O-serotypes were isolated as the causative pathogens, which were previously recognized to induce severe abdominal cramps and diarrhea. Of these, 114 strains, in which the possibility of enterohemorrhagic E. coli due to their O-serotypes was predicted, were examined for the producibility of Vero toxins. Twenty-six (76.5%) of the 34 strains of E. coli O157 produced the Vero toxins, and other 8 strains were the non-producers. Twenty of the 26 producers produced both VT1 and VT2, whereas the other 6 strains produced VT2 only. Furthermore, 4 strains of E. coli O26, and 1 strain each of E. coli O125 and O126 produced Vero toxins. Thirty-two of the 114 strains, isolated from the patients with diarrhea and selected as the enterohemorrhagic E. coli according to the specific O-serotypes, were actually confirmed produce Vero toxins. Thirty-four strains of E. coli O157 tested were susceptible to all antibiotics such as ampicillin, doxycylin, levofloxacin, fosfomycin, chloramphenicol and polymyxin B, and no strains resistant to levofloxacin, polymyxin B and fosfomycin were found.

Vascular angiotensin-converting enzyme activity in cholesterol-fed rabbits: effects of enalapril

Many reports have shown inhibitory effects of angiotensin-converting enzyme (ACE) inhibitors on the progression of atherosclerotic plaque lesions in vascular tissue of experimental models. However, no report has shown alterations of ACE activity in vascular tissue during the process of atherosclerosis. We measured ACE activity in plasma and aortic tissue in rabbits fed a cholesterol-rich (1%) or normal diet for 10 weeks. We also evaluated the blood pressure response to angiotensin (Ang) I and II. These data were compared in untreated rabbits and in rabbits receiving chronic treatment with an ACE inhibitor, enalapril (3 mg/kg/day for 10 weeks). ACE activity in aortic tissue, but not in plasma, in cholesterol-fed rabbits was gradually but significantly increased compared with that in noncholesterol-fed rabbits even after the 4-week feeding period, when no atherosclerotic lesion was observed in the aortic tissue. Treatment with enalapril for 10 weeks, but not 4 weeks, significantly reduced the ACE activity in aortic tissue in association with the reductions in the elevated Ang II level and the atherosclerotic plaque area of the aortic tissue. These results indicated that ACE activity in aortic tissue was increased during the early phase of atherosclerotic process.

[Gentamicin-induced alteration in drug susceptibility and lipopolysaccharide-composition of Pseudomonas aeruginosa isolates]

Emergency of multi-drug resistance in Pseudomonas aeruginosa isolates after exposure to gentamicin was investigated with reference to their LPS-compositions. Three strains each of P. aeruginosa, different in LPS-compositions (long- and short-LPS strains, and LPS-deficient strain) were once or repeatedly incubated overnight at 35 degrees C in Mueller-Hinton broth including different concentrations of gentamicin, a poly-cationic antibiotic. LPS-compositions of the bacteria which survived and were grown after exposure to gentamicin were analyzed and the susceptibility to some of anti-pseudomonal drugs was determined. Of the test 9 strains after single exposure, No. 4 (long-LPS) and No. 41 (short-LPS) formed the LPS-deficient mutants. The resistance to ceftazidime and gentamicin was found in No. 4 strain, but not in No. 41 strain. Drug resistance in different patterns was also found in Nos. 43, 29, 45 and 52 strains without any change in their LPS-compositions. Contrary to these results, the susceptibility to norflxacin increased in Nos. 21 and 45 strains without any change in their LPS-compositions. After repeated exposures to gentamicin, the LPS-compositions of Nos. 4 and 14 (short-LPS) were altered and formed the LPS-deficient and the Intermediate-LPS (between short and long compositions) mutants, respectively. The LPS-alteration in both strains were accompanied by the development of resistance to ceftazidime and gentamicin, respectively. The drug resistance in different patterns were also found in Nos. 43, 156, 29, 41, 21, 45 and 52 strains, without any change in the LPS-compositions, whereas the increase in susceptibility to norfloxacin was simultaneously found in No. 45 strain. The ionic-binding of [3H]-gentamicin to the cell surfaces of two LPS-deficient mutants of P. aeruginosa decreased markedly, in comparison with that of the respective parents, and these results might lead to the drug resistance in the LPS-deficient mutants. However, the gentamicin-induced resistance of some strains of P. aeruginosa (but no change in the LPS-compositions) to the test drugs including gentamicin indicates a possibility that negative charges on the bacterial surface were decreased by the drug exposure. The drug resistance and LPS-compositions in the gentamicin-induced mutants of P. aeruginosa were stable during or after the 15th in vitro serial transfers.

Large sixth nerve neuroma involving the prepontine region: case report

OBJECTIVE AND IMPORTANCE

Tumors originating from the cranial nerves are uncommon, except for the acoustic and trigeminal neuromas. The sixth nerve, however, has the potential to generate neuromas with characteristic clinical features.

CLINICAL PRESENTATION

A 54-year-old woman presented with diplopia and increased intracranial pressure. Magnetic resonance imaging showed a large mass in the prepontine region. Surgery was performed via a condylar approach and demonstrated a tumor originating from the prepontine portion of the sixth nerve.

CONCLUSION

The sixth nerve neuroma at the pontomedullary junction showed characteristic clinical features and could be successfully removed via a condylar approach.

Early increase of gut intraepithelial mast cell precursors following Strongyloides venezuelensis infection in mice

The time-course of differentiation/proliferation of mast cells in gut epithelium was investigated in mice infected with the nematode Strongyloides venezuelensis. After infection, expression of proliferating cell nuclear antigen increased in gut intraepithelial mast cells on days 7 to 11, followed by an increase in the number of intraepithelial mast cells from days 11 to 14. Mast cell precursors were defined as cells that formed mast cell colonies in methylcellulose culture. After infection, the numbers of mast cell precursors in the population of gut intraepithelial mononuclear cells (IEMNC) increased significantly on day 3 and returned to the pre-infection level by day 7. Mast cell precursors in Peyer's patches, mesenteric lymph nodes (MLN), and spleen also increased from day 7 p.i. Production of IL-3 and IL-4 in MLN and spleen were increased between 7 and 11 days p.i. These results show that murine intestinal mastocytosis is initiated by an early increase in mast cell precursor number in the gut epithelium followed by proliferation/differentiation of mast cells. Mast cell precursor numbers increased even before the production of IL-3 and IL-4 in MLN and spleen, suggesting that some local factors might be involved in this phenomenon.

Early morphologic changes of atherosclerosis induced by ventromedial hypothalamic lesion in the spontaneously diabetic Goto-Kakizaki rat

It is generally thought that typical atherosclerotic lesions do not develop in the rodent. The Goto-Kakizaki (GK) rat is a nonobese strain in which a spontaneous type of non-insulin-dependent diabetes mellitus develops without apparent macroangiopathy. In our previous study, making ventromedial hypothalamic (VMH) lesions in GK rats induced hyperphagia and a further deterioration in glucose metabolism. In the current study, male GK rats in which VMH lesions were made were examined for vascular changes, with special reference to atherosclerotic lesions. Marked hyperglycemia in GK rats with VMH lesions (hereafter referred to as VMH lesion rats) was revealed over an observation period (plasma glucose levels 16 weeks after the operation: VMH lesion GK rats, 19.3 +/- 2.0 mmol/L, vs sham-operated GK rats, 10.1 +/- 1.3 mmol/L; p < 0.0001). Light microscopic observation of the descending aorta in VMH lesion GK rats 16 weeks after the surgery revealed that the intimal thickening and the number of infiltrating cells into the intima were significantly increased as compared with sham-operated GK rats (17531 +/- 3747 microm2 vs 3072 +/- 1192 microm2, p < 0.0001; 15.6 +/- 3.1 per one transverse section vs 6.8 +/- 2.5 per one transverse section, p < 0.0005). Electron microscopic observations demonstrated an increased number of microvilli and lysosomes in endothelial cells, infiltration of macrophages and lymphocytes into the intima, and migration of medial smooth muscle cells into the intima that are considered to be early events in atherosclerosis. These morphologic changes could be induced by a deterioration in glucose metabolism. This rat may thus be useful for studying the process of the initiation of atherosclerosis in diabetes mellitus.

The presence of a manganese-rich particle in lysosome of rat pancreas due to excess manganese treatment

Manganese (Mn) accumulates at a higher level in the pancreas than in any other organs when excess Mn is administered to the rat. The present study is carried out to analyze the intracellular localization of Mn existed in the pancreatic cell of Mn-treated rats. Transmission electron microscope and X-ray micro-analysis connected with a rapid freezing fixation technique showed that a large amount of Mn was localized in lysosomal particles of the pancreatic cell of Mn-treated rats. The Mn-rich particles disappeared when the element-administration was discontinued, showing that the accumulation of Mn is reversible. To confirm that Mn is in the lysosomes, a centrifugal subcellular-fractionation and a neutron activation analysis were carried out. The result indicated that much Mn existed in the lysosomal fraction.

Visceral fat accumulation as an important risk factor for obstructive sleep apnoea syndrome in obese subjects

OBJECTIVES

It is well known that obstructive sleep apnoea-(OSA) is frequently associated with obesity. In the current study, we investigated the correlation between abdominal visceral fat accumulation and the presence of OSA in obese subjects.

SUBJECTS

A consecutive series of 37 patients (17 men and 20 women) with primary obesity who were admitted to the Second Department of Internal Medicine. Osaka University Hospital, were investigated Patients with OSA were designated as those whose apnoea index (number of apnoea h-1 of sleep) was more than 5.

MAIN OUTCOME MEASURES

The distribution of body fat was determined using computed tomographic sections. The upper airway dimensions were evaluated with indices obtained by cephalometry in both inspiratory and expiratory phases.

RESULTS

Visceral adipose tissue (AT) area which was measured at the level of the umbilicus, and its ratio to total AT area were both significantly greater in OSA patients as compared with those in non-OSA patients. All subjects whose visceral AT area measured more than 220 cm2 manifested OSA. These two parameters also closely correlated with an increase in apnoea index. A multiple linear regression analysis revealed that the visceral AT area significantly correlated to apnoea index when age, AT mass and lean body mass were taken into account. The fluctuations of the upper airway were significantly greater in the large visceral fat group than in the small visceral fat group.

CONCLUSIONS

These results suggest that visceral fat accumulation is an important risk indicator for OSA in obese subjects.

Effects of swimming training on brown-adipose-tissue activity in obese ob/ob mice: GDP binding and UCP m-RNA expression

Brown adipose tissue (BAT) of obese animals is generally in a relatively atrophied and thermogenically quiescent state. The aim of the current study was to investigate the effect of swimming training on BAT activity in lean and obese (ob/ob) mice. The trained mice underwent a 6-week endurance swimming training (1 h/day, 5 days/week) in water at 35-36 degrees C. The swimming training significantly increased BAT mass and its protein content in both the lean and obese mice, suggesting hypertrophy. After swimming training, the amounts of protein and guanosine 5'-diphosphate binding in the mitochondria recovered from BAT of both mice increased significantly as compared with the respective sedentary groups, whereas the uncoupling protein (UCP) content increased significantly only in lean mice. After swimming training, the level of UCP mRNA expression did not change substantially in lean mice but appeared to increase in obese mice. The results obtained here suggest that swimming training leads to an increase in the nonshivering thermogenesis of obese mice in addition to lean mice.

Inactivation of p16/CDKN2 and p15/MTS2 genes in different histological types and clinical stages of primary ovarian tumors

To define the involvement of p16/CDKN2 and p15/MTS2 inactivation in ovarian tumorigenesis and the association of these inactivation events with histological types and clinical stages of ovarian tumors, we analyzed homozygous deletion and somatic mutation of p16/CDKN2 and p15/MTS2 genes, as well as hypermethylation of the 5'-CpG island of the p16/CDKN2 gene, in 49 primary ovarian tumors and 6 ovarian carcinoma cell lines. We found homozygous deletions of p16/CDKN2 and p15/MTS2 in 6 (12%) and 5 (10%) primary tumors, respectively. Somatic mutation of p16/CDKN2 was found in only 1 primary tumor, but mutation of p15/MTS2 was not detected in any sample. None of the 28 primary tumors or 6 cell lines was hypermethylated at the 5'-CpG island of p16/CDKN2. The incidence of inactivation of p16/CDKN2 in primary tumors was significantly higher in the advanced stages (7 of 29) than in the early stages (0 of 14). Seven of 9 alterations in p16/CDKN2 and p15/MTS2 were observed in serous (3 of 12), endometrioid (3 of 9) and clear-cell (1 of 4) carcinomas. However, only normal sequences of these genes were detected in mucinous carcinomas. Loss of heterozygosity (LOH) at the IFNA locus was detected in 1 of 19 (5%) tumors, but no change at the D9S171 locus was observed in 17 tumors. These results suggest that: (i) homozygous deletion is the main mechanism of inactivation of p16/CDKN2 and p15/MTS2 in ovarian tumorigenesis; (ii) inactivation of p16/CDKN2 and p15/MTS2 may be the histological type-specific events involved in ovarian tumorigenesis; and (iii) inactivation of p16/CDKN2 is potentially involved in the progression of ovarian tumors in advanced stages.

Localization of heparin-binding epidermal growth factor-like growth factor in human coronary arteries. Possible roles of HB-EGF in the formation of coronary atherosclerosis

BACKGROUND

Heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) is a newly identified member of the EGF family. Our previous in vitro studies showed that HB-EGF is a potent mitogen and chemoattractant for vascular smooth muscle cells (SMCs), suggesting the role of HB-EGF in the pathogenesis of atherosclerosis. The purposes of the present study were to investigate the localization of HB-EGF in both normal and atherosclerotic human coronary arteries and to elucidate the possible roles of this growth factor in the formation of atherosclerotic lesions.

METHODS AND RESULTS

The immunohistochemical localization of HB-EGF, SMCs, macrophages, and EGF receptors (EGFRs) was examined in human coronary arteries obtained at autopsy. The medial SMCs of coronary arteries in neonates, infants, and children consistently synthesized HB-EGF protein. In normal adults, however, the relative number of HB-EGF-positive medial SMCs decreased gradually with age after about 30 years of age. In nonatherosclerotic coronary arteries with diffuse intimal thickening, SMCs of the intima, especially those located in the area of the medial side of the intima, were strongly positive for HB-EGF protein. In atherosclerotic plaques of coronary arteries with eccentric intimal thickening, both SMCs and macrophages in and around the core lesions, in addition to the intimal and medial SMCs located adjacent to the plaque, produced HB-EGF protein. A strong immunostaining of EGFRs was observed in these SMCs, suggesting a close association of HB-EGF and EGFR expression.

CONCLUSIONS

These data suggest that HB-EGF might play important roles in the migration of SMCs from the media to the intima, the proliferation of intimal SMCs, and the interaction between SMCs and macrophages in the process of coronary atherogenesis.

[A case of Sparganosis mansoni with a painless mass in the inguinal region and the scrotum]

Sparganosis mansoni rarely occurs in the inguinal and perineal regions in Japan. A case of Sparganosis mansoni with a painless mass in the left inguinal region is presented. A 67-year-old male visited our hospital with a complaint of a painless mass in the left inguinal region in May, 1995, and another mass appeared in the scrotum two days after the first visit. Ultrasonography revealed a solid subcutaneous mass 2 cm in diameter. These masses were surgically excised by an inguinal approach and a parasite, 10 cm in length, was found in the mass. The parasite was diagnosed histologically as Sparganosis mansoni, which is a larva of the genus Diphyllobothrium.

Preparation of anti-human thymidine phosphorylase monoclonal antibodies useful for detecting the enzyme levels in tumor tissues

The antitumor activity of cytostatic 5'-deoxy-5-fluorouridine (5'-dFUrd) depends on its being converted to 5-fluorouracil (5-FUra) by the enzyme thymidine phosphorylase (dThdPase, EC 2.42.4). We prepared mouse anti-human dThdPase monoclonal antibodies to serve as tools for clinical studies with this drug. Partially purified dThdPase obtained form HCT116 human colon cancer cells grown in athymic mice was used as and antigen for the immunization of mice. Six hybridomas were cloned which produced anti-human dThdPase antibodies, as detected by Western blot analysis with human dThdPase. With these antibodies, we developed an ELISA method sensitive enough to measure dThdPase levels, even in tumor tissue samples weighing as little as 10 mg. In addition, one monoclonal antibody was suitable for immunologically staining the enzyme in tumor tissues. Thus, these anti-human dThdPase monoclonal antibodies could be used to measure levels of the enzyme in tumor cells, which is essential for the activation of 5'-dFUrd.