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Biomedical subjects

M Imanishi

Publications and source records attributed to M Imanishi.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Cerebral infarction due to bacterial emboli associated with methamphetamine abuse].

The number of stimulant-drug addicts has recently been on the rise again, and they are being increasingly encountered in the emergency room. There are also frequent reports of cerebrovascular disorders complicating drug toxicity. These cerebrovascular disorders have included subarachnoid hemorrhage, intracranial hematoma, and a few cases of cerebral infarction. Here, we report the case of a 37-year-old male with drug toxicity, consciousness disorder, and hyperthermia. He was in a coma with a temperature of 43.1 degrees C and blood pressure of 58/35 mmHg when brought to our hospital. His condition worse rapidly deteriorated, and he died the same day. Cerebral infarction caused by gram-positive bacillus embolism, not necrotizing angiitis, was found at autopsy. Because drug addicts, especially stimulant-drug addicts, tend to inject themselves drug under unsanitary conditions, the possibility of this type of complication is always present. This is the first such case ever reported, and is therefore regarded as a rare complication of stimulant-drug intoxication.

Adult↗
PubMed1997

Mechanism of decreased albuminuria caused by angiotensin converting enzyme inhibitor in early diabetic nephropathy.

The mechanism of decreased albuminuria caused by an inhibitor of angiotensin converting enzyme (ACE) was investigated in patients with early diabetic nephropathy. The subjects were 10 patients with non-insulin-dependent diabetes mellitus without azotemia but with albuminuria (less than 650 mg/day). First, a two-week study was done: one week with a diet with ordinary sodium levels and one week with a sodium-restricted diet, in random order. The systemic blood pressure and urinary excretion of sodium and albumin were measured daily. Intrarenal hemodynamics, in terms of the resistance of afferent and efferent arterioles (RA and RE) and glomerular capillary pressure (PGC), were calculated from renal clearance, the plasma total protein concentration, and the pressure-natriuresis relationship. Results obtained before and two weeks after starting the ACE inhibitor cilazapril (2 mg/day) were compared. Urinary excretion of albumin was decreased by cilazapril in 8 of the 10 patients. Cilazapril decreased the RE [6830 (3680, 14,750) to 4660 (1750, 10,790) dynes.sec.cm-5, P < 0.05, mean (minimum, maximum)] and PGC (53 +/- 5 to 43 +/- 9 mm Hg, P < 0.02, mean +/- SD) in these 8 patients, but not in the two other patients. The RA was not significantly changed in any patient. The percent change caused by cilazapril in the urinary excretion of albumin was significantly correlated with the change in PGC (N = 10, r = 0.875, P < 0.01), but not with changes in the systemic blood pressure. In conclusion, the mechanism by which an ACE inhibitor caused a short-term decrease in albuminuria in early diabetic nephropathy involved a glomerular hemodynamic change, namely, a decrease in PGC.

Aged↗
PubMed1997

New multi zinc finger protein: biosynthetic design and characteristics of DNA recognition.

New six zinc finger protein DSp1 was created by connecting two Sp1 DNA binding domains. The DNA recognition characteristics of DSp1 demonstrate that (1) this multi finger protein binds eighteen contiguous base pairs of DNA sequence, (2) each zinc finger wraps around DNA major groove, and (3) two Sp1 domains have nonequivalent contribution to the DNA binding of DSp1.

Amino Acid Sequence↗
PubMed1996

Decreased prostaglandin E2 synthesis by lens epithelial cells cultured on heparin-surface-modified poly(methyl methacrylate).

PURPOSE: To evaluate whether heparin surface modification reduces prostaglandin E2 (PGE2) synthesis by lens epithelial cells (LECs) after intraocular lens (IOL) implantation. SETTING: Nishi Eye Hospital, Jinshikai Medical Foundation, Osaka, Japan. METHODS: The prostaglandin E2 (PGE2) concentration was determined in an incubation medium of human cataract LECs cultured on heparin-surface-modified (HSM) poly(methyl methacrylate) (PMMA) plates at 1, 2, 3, and 4 weeks of culture. A medium without heparin served as a control. RESULTS: The PGE2 concentration was significantly lower in the HSM than in the control medium at 3 and 4 weeks of culture. CONCLUSION: The results are consistent with the clinical observation of significantly decreased inflammation in eyes with HSM IOLs, indicating that such modification increases PMMA's biocompatibility with LECs.

Cataract↗
PubMed1996

Role of platelet-activating factor and prostanoids in hemodynamic changes in rat experimental endotoxic shock.

The present experiments were conducted to elucidate the role of platelet-activating factor (PAF) and cyclooxygenase products in the cardiovascular responses to endotoxin in anesthetized rats. Endotoxin (10 mg/kg, i.v.) induced hypotension that was accompanied by a decrease in cardiac output and an increase in calculated total peripheral resistance, suggesting that this hypotension mainly resulted from the reduced cardiac output. The endotoxin-induced decrease in cardiac output and hemoconcentration was significantly attenuated by TCV-309 (a PAF receptor antagonist), ibuprofen (a cyclooxygenase inhibitor) or S-1452 (a thromboxane A2/prostaglandin H2-receptor antagonist). During the 3-hr observation period following endotoxin administration, ibuprofen and S-1452 showed only early protection and TCV-309 showed late attenuation of the endotoxin-induced hypotension. Tachycardiac responses to endotoxin were only blocked by ibuprofen but not by TCV-309 or S-1452. These results suggest that both PAF and cyclooxygenase product(s), including thromboxane A2, mediate the decrease in cardiac output and hypotension in rat experimental endotoxic shock. Cyclooxygenase product(s) other than thromboxane A2 or prostaglandin endoperoxide may be involved in the endotoxin-induced increase in heart rate.

Animals↗
PubMed1996

Pressor and depressor hormones during alcohol-induced blood pressure reduction in hypertensive patients.

Alcohol acutely causes vasodilation and hypotension in Orientals. To study the mechanisms responsible for the alcohol-induced blood pressure (BP) reduction, we examined levels of various vasoactive hormones after a single intake of alcohol in twelve Japanese men with mild hypertension. On the alcohol intake day, they consumed 1 ml/kg of alcohol with an evening meal, while on the control day they took an isocaloric control drink. BP and vasoactive hormone levels were determined before and 2 h after intake of the alcohol or the control drink. BP after alcohol ingestion was significantly lower than that before drinking or on the control day. This alcohol-induced hypotension was associated with significant increases in heart rate, plasma catecholamines and plasma renin activity (PRA). The changes in heart rate and plasma noradrenaline were inversely related to the changes in BP. Plasma levels of vasopressin and insulin were lower in the alcohol period than in the control period, but these changes were not correlated with the changes in BP. Levels of aldosterone, cortisol, atrial natriuretic peptide, prostaglandin (PG) E2, 6-keto-PGF1 alpha, beta-endorphin, and cyclic GMP were not significantly different between the alcohol and the control periods. These results suggest that changes in pressor hormones may not contribute to the acute hypotensive effect of alcohol, and that the sympathetic nervous system is activated by the BP reduction. The levels of the depressor hormones measured also appear to play no role in alcohol-induced hypotension.

Adult↗
PubMed1996

[A case of renal cell carcinoma of the native kidney following cadaveric renal transplantation].

A case of renal cell carcinoma of the right native kidney following cadaveric renal transplantation is reported. A 44-year old male underwent cadaveric renal transplantation in 1993 and had stable graft function, but he had suffered from hypertension before the renal transplantation and multiple antihypertensive medications were not effective. Abdominal computed tomography demonstrated bilateral contracted kidneys, but we could not rule out renal cell carcinoma of the right kidney, completely. Angiography of the graft artery revealed no stenosis and venous sampling suggested that plasma renin activity was increased in the left renal vein. Thus we performed bilateral native nephrectomy. Histology of the right kidney was renal cell carcinoma, clear cell subtype, grade 1, pT2, and the left kidney was end stage of renal disease. Because of high incidence of malignant neoplasia after renal transplantation, routine careful examination is quite important.

Adult↗
PubMed1995

Effects of intravenous nitroglycerin combined with dopamine on intracranial pressure and cerebral arteriovenous oxygen difference in patients with acute subarachnoid haemorrhage.

The effects of intravenous nitroglycerin (NTG) combined with dopamine on intracranial pressure (ICP) and cerebral arteriovenous oxygen difference (AVDO2) were studied in 11 patients with acute subarachnoid haemorrhage (SAH). The study was performed on Days 1 to 3 of SAH after aneurysmal clipping. Treatment consisted of an intravenous drip infusion of NTG in increasing incremental doses of 0.5, 1.0, 1.5, 2.0, and 2.5 micrograms/kg/min at one-hour intervals. Dopamine (5 to 10 micrograms/kg/min) was also given concurrently to maintain systemic blood pressure. ICP values before NTG administration ranged from 7 to 24 mmHg (mean. 11.91 +/- 5.30 mmHg). ICP began to increase immediately after the administration of NTG 0.5 microgram/kg/min and peaked at 14.64 +/- 5.93 mmHg 10 minutes after onset of infusion. Thereafter, ICP gradually returned to pretreatment levels. Increasing the dose of NTG failed to induce further significant rises in ICP. Mean AVDO2 before NTG administration was 4.69 +/- 0.62 ml/dl. This parameter showed no significant change during NTG infusion, although cerebral perfusion pressure decreased to between 75% to 94% of the control value after NTG administration. These results indicate that continuous NTG infusion combined with dopamine does not have adverse effects on ICP (the ICP increase is minimal and transient) and may even have beneficial effects on CBF in patients with acute SAH.

Adult↗
PubMed1995

Short-term increase in prostaglandin I2 synthesis caused by cicletanine in patients with essential hypertension.

Cicletanine is a new antihypertensive drug that stimulates renal and vascular synthesis of prostaglandin (PG) I2 in experimental animals. However, there is little evidence that cicletanine increases the level of PGI2 in systemic blood of human subjects. To investigate the short-term antihypertensive mechanism of cicletanine, we measured serially the systemic blood pressure, the levels of 6-keto-PGF1 alpha (a stable metabolite of PGI2) and PGE2, and renin activity in plasma after administration of the drug. Nine patients with essential hypertension on a diet without severe sodium restriction took 100 mg of the drug by mouth. Systemic blood pressure was measured hourly for 24 h before and after cicletanine administration. The two PGs of interest were extracted, purified by high pressure liquid chromatography, and measured by radioimmunoassay. Cicletanine decreased blood pressure 3 and 6 h after administration and increased the plasma level of 6-keto-PGF1 alpha. The increase in 6-keto-PGF1 alpha was small but significant (mean +/- SD, from 3.21 +/- 1.26 to 3.88 +/- 1.44 and later 4.15 +/- 1.08 pg/mL by 3 and 6 h after administration; P < .05 and .01, respectively). The level of PGE2 had increased at 3 h after administration but returned to baseline by 6 h. Plasma renin activity was increased only at 24 h after administration. Cicletanine increased systemic PGI2 levels short-term, producing an antihypertensive effect in patients with essential hypertension.

6-Ketoprostaglandin F1 alpha↗
PubMed1995

Effect of the cytokines on the prostaglandin E2 synthesis by lens epithelial cells of human cataracts.

BACKGROUND: Lens epithelial cells (LECs) derived from human cataracts have been reported to produce various cytokines and prostaglandin E2 (PGE2) in culture. The effects of IL-1, TGF-beta, and b-FGF on the PGE2 synthesis by LECs have been studied. METHODS: A circular piece of the anterior capsule with attached LECs was obtained by capsulotomy during cataract surgery and cultured. The primary, almost confluent, cultures were used for the study. The PGE2 concentration of the culture media for 24 h was measured after the addition of recombinant human IL-1 alpha, TGF-beta 2, or b-FGF at various concentrations. The PGE2 concentration was also measured in the media to which each cytokine and rabbit polyclonal anti-human antibodies against the corresponding cytokine had been added. RESULTS: The PGE2 concentration of the culture media after addition of IL-1 alpha at the concentration of 100 or 500 pg/ml (1765 (768) and 3071 (1121) pg/10(4) cells) or TGF-beta 2 at the concentration of 10 or 100 ng/ml (689 (264) and 750 (189) pg/10(4) cells) was significantly increased compared with that in the controls (67 (20) pg/10(4) cells). These effects were suppressed by the corresponding anticytokine antibodies. Basic FGF and anti-human b-FGF showed no significant effect on the PGE2 concentration. IL-1 and TGF-beta increased but b-FGF did not affect the PGE2 synthesis by LECs in culture. CONCLUSION: IL-1 and TGF-beta may participate in postoperative inflammation after cataract surgery by increasing PGE2 synthesis by residual LECs.

Cataract↗
PubMed1995

Collaborative work to determine an optimal administration period and optimal parameters for detection of effects on male fertility in rats--male reproductive toxicity study of haloperidol.

Haloperidol, a neuroleptic, was orally administered at 0, 3, 10, 30 and 60 mg/kg/day in a 4-week dosing study, and 0, 3, 10 and 30 mg/kg/day in a 9-week dosing study, to Sprague-Dawley male rats which were then sacrificed for histopathological examination or mated with untreated females. The males in the mating groups were continuously treated during the mating period. Sperm positive females were sacrificed on day 20 of gestation. The males in the histopathology groups were sacrificed after 4- or 9-week dosing and their testes were fixed in Bouin's fluid and sections stained with HE or PAS. The mated males were sacrificed and reproductive organ weights were determined. At 3 mg/kg or more, reduced spontaneous motor activity was observed and body weights were lowered. The absolute weight of testes was decreased with 60 mg/kg in the 4-week dosing study, and was decreased with 10 and 30 mg/kg in the 9-week dosing study. However, the relative weight was increased or showed a tendency to increase. In the 4-week dosing study, decrease in the fertility index with 60 mg/kg and increase in pre-implantation loss with 30 mg/kg or more were noted. However, there were no adverse effects on the copulation index in any of the treated groups. The males given 60 mg/kg showed slight changes in the testes (necrosis of pachytene spermatocytes in seminiferous tubules of stage VII, exfoliation of round spermatids in the lumina and atrophy of Leydig cells) and seminal vesicles (atrophy of epithelial cells). Atrophy of Leydig cells was also observed at 30 mg/kg in the 4-week dosing study. In the 9-week dosing study, neither male reproductive ability nor histopathological parameters were affected by haloperidol up to 30 mg/kg. From the results detailed above, it may be concluded that 4-weeks dosing before mating is suitable for detection of effects of haloperidol on male reproductive ability, and that histopathological changes together provide an optimal parameter for predicting male reproductive disorders.

Animals↗
PubMed1995

Lipoma in the quadrigeminal cistern--case report.

A 65-year-old male presented with a rare lipoma in the quadrigeminal cistern manifesting as left abducens nerve paresis which was effectively treated by total extirpation. The usual neurological symptoms of lipoma in the quadrigeminal cistern are intracranial hypertension and hydrocephalus which can be successfully treated by shunt operation. Direct surgery is indicated when the symptoms are ascribed to localized symptoms, but tumor removal should be partial if the superior cerebellar arteries are involved.

Aged↗
PubMed1995

[Tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) in transplanted kidneys].

We have studied the involvement of fibrinolysis in acute rejection after kidney transplantation by analyzing changes in urinary levels of substances such as FDP, D-dimer, tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI). Fibrinolytic activity was found to be low (that is, PAI is dominant) during acute rejection, and it was elevated (that is, PA became dominant) as acute rejection subsided. It appears that the dominance of PA leads to an increase in the products of fibrinolysis and an elevation in the D-dimer/FDP ratio, resulting in disappearance of the acute rejection. Based on these findings, we thought it necessary to administer t-PA to kidney recipients so that PA becomes dominant earlier and the acute rejection can be reduced. It is necessary for us to directly study the phenomena within the kidneys. Therefore, we recently conducted a histochemical study of the distribution of t-PA, Urokinase type PA (u-PA) and PAI in transplanted kidneys. Transplanted kidney, which functioned well or showed signs of acute or chronic rejection, were biopsied. These renal samples as well as control samples (biopsied from normal nongrafted kidney) were examined as to distribution of t-PA, u-PA and PAI by the indirect enzyme complement method. In conclusion, t-PA, u-PA and PAI were detected in the glomeruli, arterioles, tubule and interstices of the control kidneys, well functioning grafts, acutely rejected grafts chronically rejected grafts. All samples showed intense chromatic responses in the arterioles and part of the tubules. On the whole, the chromatic response tended to be more intense in the acute rejection group than in the other group.

Fibrinolysis↗
PubMed1995

[A huge idiopathic brain stone in the posterior fossa].

We report a case of idiopathic brain stone occurring in the posterior fossa. A 72-year-old woman with a huge calcified mass in the posterior fossa on plain craniogram was referred to us. She had suffered from intractable tinnitus and mild cerebellar ataxia for twenty years. CT scan revealed a dense bony mass in the posterior fossa. Angiogram only showed an avascular huge mass in the posterior fossa. MRI clearly revealed the shape, heterogenous composition and anatomical relation to the surrounding structure of the mass. The mass was totally removed uneventfully under ABR and SEP monitoring. The patient was discharged with improvement of subjective symptoms. The mass was histologically diagnosed as an idiopathic brain stone because its components were mainly calcified tissues and collagen fiber of unknown etiology; no viable cells were found in any of the specimens. Idiopathic brain stones are very rare and only eight cases have been reported in the literature. The etiology and clinical symptoms of this condition are briefly discussed.

Aged↗
PubMed1995

[Dural AVF of the posterior fossa associated with sinus occlusion presenting as intracerebral hemorrhage: case report].

A 69-year-old man was admitted because of sudden onset of consciousness disturbance. Neurological examination on admission revealed slightly disturbed consciousness, sensory aphasia and right hemiparesis. CT scan disclosed a hematoma in the left posterior temporal lobe. Left carotid angiograms showed dural AVF of the transverse/sigmoid sinus fed mainly by the left occipital and posterior auricular arteries. On the angiograms the left sigmoid sinus was completely occluded. This was associated with retrograde venous flow into the cortical veins, the superior petrosal sinus and the contralateral traverse sinus. After stabilizing the condition, we totally resected the dural AVF including the left transverse sinus. The postoperative course was uneventful. Histopathological examination of the surgically resected specimen revealed that the dural A-V fistula per se existed in the sinus wall.

Aged↗
PubMed1995

[Clinical statistics of 67 cadaveric renal transplantation at the Department of Urology, Kinki University School of Medicine].

A statistic survey was made on the patients undergoing cadaveric renal transplantation between June, 1980 and December, 1993. The total number of patients was sixty-seven. The number of patients per year increased annually. The graft survival rate was 73.8% at 1 year and 63.1% at 5 years. Some transition was seen in immunosuppressive regimens using cyclosporin.

Adolescent↗