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Biomedical subjects

H Nishida

Publications and source records attributed to H Nishida.

At least 253 records · Page 14Linked to original sources
PubMed1995

[Experimental study on organ perfusion by intraaortic balloon counterpulsation with double balloon catheter].

Newly-developed catheter for the intraaortic balloon counterpulsation with cardio-renal assist was examined on animal model. The catheter consists of two balloon segments between which the celiac trunk, the superior mesenteric artery and the renal artery are to be placed. Statistical comparison on each hemodynamic element was carried out between the catheter (DBC), conventional single balloon catheter (SBC) of the same balloon volume as DBC and no assist (None) groups. There were no significant changes between SBC and DBC in cardiac output, femoral arterial flow and central venous pressure. Renal arterial flow and urinary output were significantly increased in DBC (None 14.4 +/- 3.9, SBC 22.6 +/- 5.6, DBC 31.0 +/- 6.9 ml/min in renal arterial flow, None 33 +/- 9, SBC 64 +/- 14, DBC 78 +/- 20 ml/h in urinary output, p < or = 0.05). After the remodeling adjust to the human stature, a clinical application would be considered.

Animals↗
PubMed1995

[Surgical results of aortitis syndrome (Takayasu disease) combined with annuloaortic ectasia].

From March 1973 to December 1994, 8 patients (2 males and 6 females) aged 34.4 +/- 7.8 years, underwent composite graft replacement (CGR) for aortitis syndrome combined with annuloaortic ectasia (AAE) in our institute. Five patients showed active aortitis syndrome and steroid therapy was administrated to 2 of them. The mean value of the C-reactive protein (CRP) was 1.6 +/- 1.8 before the operation. The maximum diameter of the ascending aorta was 67.1 +/- 10.3 mm (range 53 to 85 mm). Stenosis and/or ectasia of the neck vessels were recognized in 5 cases, as well as the coronary artery in 2 cases. Isolated CGR was performed in 6 cases, and combined with single CABG to LAD in 1 case and with total arch replacement in 1 case. The enlarged ascending aorta was replaced with main graft using the exclusion method and interposed grafts for coronary arteries were sutured with pledgetted mattress sutures all around the coronary ostia. In patients with stenosis of neck vessels, oxygen saturation of the jugular vein was monitored during extracorporeal circulation for surveillance of cerebral ischemia. There was 1 early death due to pulmonary failure. Seven cases survived without any complications during 4-132 months (mean 83.4 months) of the follow-up period. After the operation, 3 cases required steroid therapy during 4-50 months. We concluded that preoperative control of active inflammation, selection of operative procedures, timing for the operation, and the long-term precise management of the intractable disease were essential for successful treatment of aortitis syndrome with AAE.

Adult↗
PubMed1994

Existence of an enzymatic pathway furnishing arachidonic acid for prostaglandin synthesis from arachidonoyl CoA in rabbit kidney medulla.

We examined whether arachidonoyl CoA (AA-CoA) can be a possible supplier of arachidonic acid (AA) for prostaglandin (PG) synthesis in rabbit kidney medulla. AA-CoA was preincubated with or without the 105,000 g supernatant (cytosol) fraction from the kidney medulla for 5 min at 37 degrees C followed by the incubation with the microsomal fraction (0.5 mg protein) (a rich source of PG synthesizing enzymes) in the presence of reduced glutathione and hydroquinone for 5 min at 37 degrees C, and the formed PGE2, F2 alpha and D2 were measured by high-pressure liquid chromatography using 9-anthryldiazomethane for derivatization. The addition of AA-CoA (20 nmol) alone changed the total PG formation (the sum of PGE2, F2 alpha and D2) from 0.14 to 1.55 ng. When the cytosolic fraction (10-100 microliters) was added together with 20 nmol-AA-CoA in the preincubation mixture, total PG formation was further increased 2- to 3-fold compared to AA-CoA alone. Experiments utilizing AA, instead of AA-CoA and boiled cytosolic fraction revealed that the stimulatory action of the cytosolic fraction on the AA-CoA-induced PG synthesis may not be due to the effect on cyclooxygenase activity and due to long-chain acyl CoA hydrolase. These results show that long-chain acyl CoA hydrolase which hydrolyzes AA-CoA to AA is present in the cytosol of rabbit kidney medulla and suggest that this enzyme activity is a potential mediator of supply of AA for PG synthesis in this region.

Acyl Coenzyme A↗
PubMed1994

Severe B cell depletion in newborns from renal transplant mothers taking immunosuppressive agents.

There have been several reports of successful pregnancies of kidney transplant mothers receiving immunosuppressive agents such as CsA and/or AZA. However, few papers have investigated immune function of neonates from those mothers. We investigated the lymphocyte subpopulations and T cell subsets in cord blood of newborn infants from those mothers. The subjects were 6 infants born to mothers following renal transplantation, who all were receiving CsA, AZA, and methylprednisolone. Cord blood and peripheral blood at 1 month and 3 months of age were obtained from the subjects. Control samples were obtained from 5 normal newborns. The polyclonal antibody used to investigate B cells was anti-F(ab')2 fragment of human immunoglobulin. Direct immunofluorescence staining and flow cytometry were used for the investigation. The number of B cells and the percentage of B cell in total mononuclear cells were significantly lower in the subjects than in normal controls. There was no significant difference between numbers of CD2+, CD4+, or CD8+ cells in the subjects and the controls. This severe B cell depletion remained low at 1 month and 3 months of life in many cases. From our result, it is very possible that the B cell line is more sensitive to immunosuppressants in utero than the T cell line. Infants of mothers taking immunosuppressive agents during their pregnancy should be followed carefully for possible insufficiency of immune function.

Adult↗
PubMed1994

Induction of notochord during ascidian embryogenesis.

The tadpole larva of solitary ascidians has 40 notochord cells in its tail. Of these cells, 32 in the anterior and middle part of the tail are derived from the A-line blastomeres, while 8 in the posterior part of the tail originate from the B-line blastomeres. Previous experiments involving continuous dissociation of daughter blastomeres from the first cleavage to the 110-cell stage suggested that cellular interactions may be involved in the formation of notochord cells. In the present study, the presumptive-notochord blastomeres isolated from the 32-cell embryos did not develop features of notochord. These results suggest that cellular interactions may be required for the fate specification of notochord, that is to say, notochord formation occurs as a result of inductive interaction between blastomeres. In order to confirm the involvement of induction in the determination of notochord and to identify the inducer blastomeres, the presumptive-notochord blastomeres at the 32-cell stage were coisolated or recombined with one of the surrounding blastomeres in a series of experiments. The results suggested that, for the A-line precursors, notochord differentiation occurs as the result of an inductive influence from vegetal blastomeres that include the presumptive-endoderm blastomeres and the presumptive-notochord blastomeres themselves. It was also suggested that induction of notochord is complete by the 64-cell stage and that inductive interactions have to be initiated before the decompaction of blastomeres during the 32-cell stage. Ascidians are Urochordata and are closely related to vertebrates. In vertebrates, it is well known that inductive interactions play a crucial role in the determination of notochord. It appears, therefore, that induction of notochord is common throughout the phylum Chordata.

Alkaline Phosphatase↗
PubMed1994

Effect of 13-hydroperoxy-9,11-octadecadienoic acid (13-HPODE) on arachidonic acid metabolism in rabbit platelets.

1. The effect of 13-hydroperoxy-9,11-octadecadienoic acid (13-HPODE) on the formation of thromboxane (TX) B2, 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) and 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) from exogenous arachidonic acid in washed rabbit platelets was examined. 2. 13-HPODE inhibited TXB2 and HHT formation without affecting 12-HETE production. 3. 13-Hydroxy-9,11-octadecadienoic acid which was produced rapidly from 13-HPODE, did not suppress the formation of TXB2 and HHT, indicating the requirement of the hydroperoxy moiety for the inhibitory effect of 13-HPODE on TXB2 and HHT formation. 4. Experiments utilizing mannitol and dimethyl sulfoxide (hydroxy radical scavengers) revealed that the action of 13-HPODE is not due to hydroxy radicals which are expected to be formed from 13-HPODE. 5. These results suggest that 13-HPODE is a selective inhibitor of platelet cyclo-oxygenase and may have functional effects within platelets.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1994

Inhibition of 15-hydroxy prostaglandin dehydrogenase activity in rabbit gastric antral mucosa by 13-hydroperoxyoctadecadienoic acid.

The effect of 13-hydroperoxyoctadecadienoic acid (13-HPODE), a hydroperoxy adduct of linoleic acid (LA), on the activities of prostaglandin (PG) synthesizing and catabolizing enzymes in rabbit gastric antral mucosa was examined. 13-HPODE had no effect on the synthesis of PGE2, PGF2 alpha and PGD2 from exogenous arachidonic acid in the microsomal fraction of the gastric mucosa at concentrations ranging from 5-20 microM. On the other hand, at 1-10 microM, it inhibited the activity of 15-hydroxy PG dehydrogenase (PGDH), which catalyzes the initial step of catabolism of PGs, in a dose-dependent manner. The concentration required for 50% inhibition was approximately 1 microM. Experiments utilizing LA, 13-hydroperoxyoctadecadienoic acid and Fe2+ indicated the requirement of the hydroperoxy moiety for the inhibitory effect of 13-HPODE on the PGDH activity. These results suggest that 13-HPODE has the potential to increase the levels of biologically active PGs in gastric mucosa by preventing their inactivation and may have functional effects within the stomach.

Animals↗
PubMed1994

Coronary artery bypass grafting in chronic renal dialysis patients: intensive perioperative dialysis and extensive usage of arterial grafts.

Twenty-three chronic renal dialysis patients underwent coronary artery bypass grafting (CABG). Eighteen patients were maintained on hemodialysis and 5 patients received continuous ambulatory peritoneal dialysis. Eighteen patients (78%) had triple vessel disease or left main disease. The mean number of revascularized vessels was 2.2 +/- 0.8, and the graft materials used were left internal thoracic artery (21), right internal thoracic artery (7), right gastroepiploic artery (7), and saphenous vein (15). The utilization index of arterial grafts (percentage of patients with at least one arterial graft) was 95.7%. Intraoperative hemodialysis (HD) was performed during cardiopulmonary bypass in all patients. In 17 patients on HD preoperatively, peritoneal dialysis (PD) was initiated immediately after the operation, and maintained until the hemodynamics stabilized sufficiently to resume HD (mean: 5.7 +/- 3.4 days after operation). In the patients with a gastroepiploic artery pedicle, PD could be established without leakage of dialysis fluid into the pericardial cavity by means of making a smaller hole in the diaphragm, passing the skeletonized portion of the graft through the hole and sealing the hole using fibrin glue. There were no hospital deaths. Angiography revealed an overall graft patency rate of 95.8% (46/48), and all arterial grafts were patent. There were 4 late deaths (1 cardiac, 3 cerebral hemorrhage). In conclusion, CABG can be accomplished in chronic renal dialysis patients with excellent early and long-term results through an intensive perioperative dialysis program and extensive usage of arterial grafts.

Adult↗
PubMed1994

Inhibitory effects of (-)-epigallocatechin gallate on spontaneous hepatoma in C3H/HeNCrj mice and human hepatoma-derived PLC/PRF/5 cells.

The inhibitory effect of (-)-epigallocatechin gallate (EGCG), a main constituent of Japanese green tea, on spontaneous hepatoma in C3H/HeNCrj mice was investigated. A total of 72 mice were divided into three groups; the control group without EGCG, and two experimental groups receiving 0.05% (w/w) or 0.1% EGCG in drinking water. EGCG reduced the incidence of hepatoma-bearing mice from 83.3% (control) to 56.0% (0.05% EGCG) and 52.2% (0.1% EGCG), and also reduced the average number of hepatomas per mouse from 1.83 (control) to 0.72 (0.05% EGCG) and 0.91 (0.1% EGCG) at week 65. Ridit analysis of the distribution of the number of hepatomas in each group revealed that EGCG significantly increased the rate of mice without hepatoma in the two EGCG groups as compared to the control. EGCG did not affect body weight gain, food consumption or any serum biochemical parameter. EGCG inhibited the growth and secretion of alpha-fetoprotein by human hepatoma-derived PLC/PRF/5 cells without decreasing their viability. These results indicate that EGCG may be a practical, nontoxic preventive agent against human hepatoma.

Animals↗
PubMed1994

Water balance, electrolytes and acid-base balance in extremely premature infants.

There are few reported studies of water balance and electrolyte abnormalities in extremely low birthweight (ELBW) infants weighing < 1000 g nursed in high humidity. We retrospectively analyzed water balance, electrolyte and acid-base balance in 100 ELBW infants, of whom 72 were appropriate for gestational age (AGA) and 28 were small for gestational age (SGA). They were cared for in closed incubators at almost full ambient humidity. Fluid intake was restricted to 50-60 mL/kg on the first day of life and was adjusted to maintain normal serum Na concentration. Weight loss in AGA and SGA infants was 21.6 and 16.7%, respectively, and was associated with large urine volume rather than insensible water loss. The incidence of hypernatremia (> 150 mEq/L) and hyponatremia (< 130 mEq/L) was 8.0 and 33.3%, respectively. The incidence of hyperkalemia in AGA infants was 37.0%, and 14.8% in the SGA group. However, hyperkalemia requiring treatment was rare. The incidence of late metabolic acidosis in AGA and SGA infants was 84.6 and 37.5%, respectively (P < 0.01). The difference in water balance and electrolyte abnormalities in AGA and SGA infants needs to be taken into account in managing ELBW infants.

Acid-Base Equilibrium↗
PubMed1994

Overview of sudden infant death syndrome in Japan.

In spite of rapid medical advancement in the care of infants and children, not only the general public but also many medical personnel have remained unaware of sudden infant death syndrome (SIDS) until very recently in Japan. In 1981, a research project team on SIDS financed by the Ministry of Health and Welfare was founded. Current incidence of SIDS is estimated to be about 0.5 per 1000 live births. The SIDS Family Association was organized in 1993 in Japan and began to publicize the social importance of SIDS and to support SIDS families by training befrienders. A series of article on current achievements from SIDS research projects and from the SIDS Family Association are submitted to this issue. The present paper summarizes the status of SIDS in Japan by overviewing the activities of the research team and the SIDS Family Association.

Family↗
PubMed1994

Epidemiology of sudden infant death syndrome in Japan.

An epidemiological survey was carried out to examine the present situation with respect to sudden infant death syndrome (SIDS) in Kanagawa Prefecture. Questionnaires on sudden unexpected death of infants aged < 1 year in 1990-91 were sent to the hospitals and clinics in Kanagawa Prefecture which may take care of such infants. By analysing information from 10,485 replies, 48 out of 73 reported sudden infant deaths were confirmed to be SIDS, although autopsy was not performed in 13 cases (27%). The incidence of SIDS per 1000 live births in Kanagawa Prefecture was 0.29 in 1990 and 0.31 in 1991; and if limited to autopsy cases 0.19 and 0.25, respectively. Sudden infant death syndrome cases in Japan were found to occur more frequently when infants were < 6 months old, at home and sleeping alone, but less in the winter and between midnight and early morning. There was little difference between the numbers in prone and supine sleeping positions at discovery. It was not clear whether SIDS occurred more often to babies sleeping prone than supine, because there were no controls matched with the SIDS cases. In future, continuous epidemiological surveys of SIDS in Japan should be carried out.

Age Factors↗
PubMed1994

Comparative study of five types of IABP balloons in terms of incidence of balloon rupture and other complications: a multi-institutional study.

The Multi-Institutional IABP Balloon Study Group in Japan (14 institutions) conducted a retrospective nonrandomized study to elucidate the incidence and type of IABP balloon-related complications relative to design and durability of five different clinically available balloons: TMP (n = 960), Kontron (n = 943). Datascope (n = 485), Mansfield (n = 226), and Aries (n = 189) balloons. A total of 2,803 patients (1,973 males, 830 females, mean age 62.1 years) spent a total of 243,856 h on the pump. Forty-nine balloons (1.7%) ruptured as recognized by the appearance of blood in the catheter (39 cases) or console alarm (4 cases). Ten patients required surgical removal of the balloon due to entrapment. Other IABP balloon-related complications requiring surgical intervention or with a lethal outcome occurred in 89 patients (3.2%). They included lower limb ischemia (61 cases), hematoma (11 cases), extensive dissection (6 cases), perforation (5 cases), entrapment without balloon rupture (3 cases), and mesenteric infarction (3 cases). The incidence of rupture, other major complications, and total complications, respectively, for each balloon was 0, 2.7, and 2.7 for TMP, 1.6, 4.3, and 5.9% for Kontron, 4.1, 1.9, and 6.0% for Datascope, 1.3, 2.7, and 4.0% for Mansfield, and 5.8, 3.7, and 9.5% for Aries. In conclusion, the TMP balloon demonstrates a significantly lower rate of rupture while the incidence of other complications for the 5 balloons is not significantly different.

Equipment Failure↗
PubMed1994

Pulsatile flow and simple flow control method during weaning period in centrifugal pump: toward more expanded usage in open heart surgery.

To expand the usage of the centrifugal pump (CP) in open heart surgery, we performed two studies. In the first, we evaluated pulsatile flow in the CP. In vitro pump performance of the Terumo Capiox pump (TCP) and the Sarns Delphin pump (SDP) and increase of free hemoglobin (mg/dl) after driving 6 h were investigated using bovine blood. A roller pump (RP) was used as a comparison. Equally effective pulsatile flow was obtained in both CPs. Hemolysis was less severe in TCP (120 mg/dl) than SDP (210 mg/dl) and RP (320 mg/dl). In the second study, we evaluated a simple flow control method. Flow rate was easily controlled with step-wise clamping of 3-pronged tubing (Triple-flow) without changing rotational speed, regardless of afterload. Fluctuation of flow was much less with this method than with the rotational speed change method. The use of pulsatile flow of TCP, with its minimum increase of hemolysis and the easier flow control method during the weaning process, may expand the usage of CP in open heart surgery.

Animals↗
PubMed1994

Less platelet damage in the curved vane centrifugal pump: a comparative study with the roller pump in open heart surgery.

The centrifugal pump with the curved vane (Lifestream Centrifugal Pump [LCP]) was applied to cardiopulmonary bypass (CPB) in 10 patients who underwent elective coronary artery bypass grafting. Serum hemoglobin levels, platelet counts, and serum beta-thromboglogulin (beta-TG) levels were measured during CPB. The results were compared with those for a comparative roller pump (RP) group (n = 10). There was no difference in CPB time between LCP (112 +/- 22 min) and RP (121 +/- 22 min) groups. Serum beta-TG levels (ng/ml) were lower in the LCP group than in the RP group (34 +/- 9 vs. 101 +/- 80, 5 min; 81 +/- 33 vs. 236 +/- 112, 30 min; 120 +/- 53 vs. 314 +/- 100, 60 min after initiation of CPB; p < 0.05). There were no significant differences in hemolysis and platelet depletion. The LCP showed excellent hemodynamic performance with less blood trauma in clinical application to open heart surgery.

Cardiopulmonary Bypass↗
PubMed1994

Induction of the conversion of xanthine dehydrogenase to oxidase in rabbit liver by Cu2+,Zn2+ and selenium ions.

Effects of Cu2+,Zn2+,Fe2+ and selenium ions on the conversion of xanthine dehydrogenase to oxidase in rabbit liver were examined. Under basal conditions, xanthine oxidase activity represented only 16% of the total xanthine oxidase plus dehydrogenase activity. Cu2+ (2-10 microM), Zn2+ (5-30 microM) and selenium ions (5-100 microM) brought about the conversion of xanthine dehydrogenase to oxidase in a dose-dependent manner. The concentrations of Cu2+,Zn2+ and selenium ions required for increasing xanthine oxidase activity by 50% was approximately 4, 10 and 20 microM, respectively. On the other hand, Fe2+ had no effect on the conversion of the enzyme up to 100 microM. These results suggest that Cu2+,Zn2+ and selenium ions have the potential to modulate the conversion of xanthine dehydrogenase to oxidase in rabbit liver.

Allopurinol↗