Biomedical subjects

Y Kamijo

Publications and source records attributed to Y Kamijo.

At least 19 recordsLinked to original sources

PubMed2001

Effect of neutral endopeptidase inhibitor on bradykinin-induced bronchoconstriction.

To evaluate whether neutral endopeptidase (NEP) inhibitors have adverse respiratory effects, the influence of a NEP inhibitor on bradykinin (BK)-induced bronchoconstriction was investigated. In anesthetized and artificially ventilated guinea pigs, changes in airway opening pressure (Pao) were measured as an index of bronchoconstriction. An infusion of phosphoramidon (3 mg kg(-1) h(-1)), a NEP inhibitor, significantly enhanced the bronchoconstriction induced by high-dose BK (30 nmol kg(-1), i.v.). Capsaicin (0.1 mg kg(-1), i.v.) and SR48968 (0.3 mg kg(-1), i.v.), an NK2 receptor antagonist, significantly inhibited the phosphoramidon-induced enhancement of BK-induced bronchoconstriction, although FK888 (3 mg kg(-1), i.v.), an NK1 receptor antagonist, did not. Both neurokinin A (NKA) (0.1-3 nmol kg(-1), i.v.) and substance P (SP) (0.1-3 nmol kg(-1), i.v.) induced dose-dependent bronchoconstriction which was enhanced by phosphoramidon infusion, although these enhancements were more prominent in the NKA series. Phosphoramidon partially inhibited BK degradation in lung homogenate, and both NKA and SP degradation in the lung homogenate were significantly suppressed by phosphoramidon. In bronchoalveolar lavage fluid (BALF), levels of NKA and SP were significantly elevated after a bolus of BK with a phosphoramidon infusion. These results suggest that NEP inhibitors may have adverse respiratory effects resulting from inhibition of the degradation of neurokinins, but mainly of NKA, when a large amount of BK is generated.

Animals↗

PubMed2001

Alkaline esophagitis evaluated by endoscopic ultrasound.

CASE REPORT: Two patients with corrosive esophagitis caused by alkaline household agents were examined with endoscopic ultrasound using a 20-MHz probe. In the first case, endoscopic ultrasound revealed circumferentially thickened mucosa and muscularis propria, and lack of differentiation between the mucosa and submucosa. However, esophageal stricture did not develop during 3 months of follow-up, suggesting that the deep lesion may have involved a narrow section of esophagus only. In the second case, a markedly thickened mucosa was seen, resulting in no sequelae. Endoscopic ultrasound offers a more accurate evaluation of the depth of the lesions in alkaline esophagitis compared to standard endoscopy or computed tomography. Longitudinal studies are needed to identify lesions at greatest risk for progression to stricture.

Adult↗

PubMed2001

Acute mercuric chloride poisoning: effect of co-ingested milk on outcome and continued hyperamylasemia.

Thirty-six h after intentionally ingesting 25 g of mercuric chloride powder mixed with 5O mL of milk, an elderly woman presented to the emergency department with diffuse upper gastrointestinal erosions and acute renal failure. The patient was treated with dimercaprol and hemodialysis, and was discharged from the hospital without clinically apparent sequelae. However, elevated serum concentrations of amylase and proteases persisted for several months despite normal findings by computed tomography including contrast administration. Delayed absorption and weakened corrosive effect may have resulted from the binding of mercuric chloride to thiol-containing proteins in milk, improving the clinical outcome.

Administration, Oral↗

PubMed2000

Constitutive regulation of cardiac fatty acid metabolism through peroxisome proliferator-activated receptor alpha associated with age-dependent cardiac toxicity.

The peroxisome proliferator-activated receptor alpha (PPARalpha) is a member of the nuclear receptor superfamily and mediates the biological effects of peroxisome proliferators. To determine the physiological role of PPARalpha in cardiac fatty acid metabolism, we examined the regulation of expression of cardiac fatty acid-metabolizing proteins using PPARalpha-null mice. The capacity for constitutive myocardial beta-oxidation of the medium and long chain fatty acids, octanoic acid and palmitic acid, was markedly reduced in the PPARalpha-null mice as compared with the wild-type mice, indicating that mitochondrial fatty acid catabolism is impaired in the absence of PPARalpha. In contrast, constitutive beta-oxidation of the very long chain fatty acid, lignoceric acid, did not differ between the mice, suggesting that the constitutive expression of enzymes involved in peroxisomal beta-oxidation is independent of PPARalpha(.) Indeed, PPARalpha-null mice had normal levels of the peroxisomal beta-oxidation enzymes except the D-type bifunctional protein. At least seven mitochondrial fatty acid-metabolizing enzymes were expressed at much lower levels in the PPARalpha-null mice, whereas other fatty acid-metabolizing enzymes were present at similar or slightly lower levels in the PPARalpha-null, as compared with wild-type mice. Additionally, lower constitutive mRNA expression levels of fatty acid transporters were found in the PPARalpha-null mice, suggesting a role for PPARalpha in fatty acid transport and catabolism. Indeed, in fatty acid metabolism experiments in vivo, myocardial uptake of iodophenyl 9-methylpentadecanoic acid and its conversion to 3-methylnonanoic acid were reduced in the PPARalpha-null mice. Interestingly, a decreased ATP concentration after exposure to stress, abnormal cristae of the mitochondria, abnormal caveolae, and fibrosis were observed only in the myocardium of the PPARalpha-null mice. These cardiac abnormalities appeared to proceed in an age-dependent manner. Taken together, the results presented here indicate that PPARalpha controls constitutive fatty acid oxidation, thus establishing a role for the receptor in cardiac fatty acid homeostasis. Furthermore, altered expression of fatty acid-metabolizing proteins seems to lead to myocardial damage and fibrosis, as inflammation and abnormal cell growth control can cause these conditions.

Aging↗

PubMed2000

Enantioselective determination of bromoisovalerylurea by liquid chromatography on chiral stationary phase in reversed- or normal-phase partition mode.

Bromoisovalerylurea (bromvalerylurea) is a sedative-hypnotic given orally as a racemate. Enantiomers of this drug could be separated by high-performance liquid chromatography on the three chiral stationary phases (a vancomycin-bonded, beta-cyclodextrin derivative-bonded, or urea derivative-bonded phase). Biological fluids of human subjects who had ingested toxic or therapeutic doses of the racemate were chromatographed after liquid-liquid extraction. The (+)-enantiomer concentration was almost equal to the (-)-enantiomer concentration in the serum of one overdosed patient. In all the other subjects, the (+)-enantiomer was less than the (-)-enantiomer in their sera and saliva. The data suggest that the drug is absorbed non-stereoselectively from the gastrointestinal tract and eliminated from the blood stereoselectively.

Adult↗

PubMed2000

The effect of a hemofilter during extracorporeal circulation on hemodynamics in patients with SIRS.

OBJECTIVE: To evaluate the hypothesis that extracorporeal hemopurification with a hemofilter contributes to the stabilization of hemodynamics in patients with systemic inflammatory response syndrome (SIRS) due to a mechanism other than the removal of cytokines. DESIGN: Prospective study. SETTING: Intensive care unit (ICU) in a university hospital. PATIENTS: Seven critically ill patients who met criteria for SIRS with unstable hemodynamics requiring vasopressors after emergency surgery. INTERVENTIONS: Before initiation of continuous hemofiltration (CHF) extracorporeal circulation through the hemofilter (ECC) with a hollow-fiber polyacrylonitrile hemofilter was performed for 6 h. MEASUREMENTS AND RESULTS: Vital signs were monitored continuously and hemodynamics were evaluated intermittently. The blood level of endotoxin and the plasma levels of cytokines were measured at 0 and 6 h. Changes in plasma levels of cytokines passing through the hemofilter were evaluated at 3 h. A significant decrease of body temperature (P < 0.05 at 3 and 6 h vs 0 h), a significant elevation of mean arterial pressure (P < 0.05 at 0.5 h, P < 0.01 at 3 and 6 h vs 0 h), and a significant increase of urinary flow rate (P < 0.05 at 0 to 3 h vs -3 to 0 h) were observed with ECC. Neither the blood level of endotoxin nor the plasma levels of cytokines decreased. A significant increase of plasma IL-6 as it passed through the hemofilter was noted. CONCLUSIONS: The beneficial effects of hemopurification with a hemofilter on SIRS patients are possibly due to mechanisms other than the elimination of cytokines with ultrafiltration, diffusion, or adsorption.

Aged↗

PubMed2000

Pulse steroid therapy in adult respiratory distress syndrome following petroleum naphtha ingestion.

CASE REPORT: A suicide attempt by a 23-year-old woman involved ingestion of 1000 mL of petroleum naphtha. Early chemical pneumonitis was complicated by life-threatening, diffuse interstitial lung consolidation with pneumatoceles. Pulse steroid therapy beginning on day 17 was associated with remarkable resolution of interstitial consolidation, although an enlarging secondarily infected pneumatocele ruptured to produce a bronchopleural fistula. Thoracic surgery and antibiotic therapy resulted in improvement of the patient's respiratory condition, and she was discharged with no residual respiratory symptoms. High-dose corticosteroid therapy appears to be a useful addition to aggressive supportive treatment in late adult respiratory distress syndrome following hydrocarbon ingestion.

Adult↗

PubMed2000

Sex-dependent regulation of hepatic peroxisome proliferation in mice by trichloroethylene via peroxisome proliferator-activated receptor alpha (PPARalpha).

The mechanism of trichloroethylene-induced liver peroxisome proliferation and the sex difference in response was investigated using wild-type Sv/129 and peroxisome proliferator-activated receptor alpha (PPARalpha)-null mice. Trichloroethylene treatment (0.75 g/kg for 2 weeks by gavage) resulted in liver peroxisome proliferation in wild-type mice, but not in PPARalpha-null mice, suggesting that trichloroethylene-induced peroxisome proliferation is primarily mediated by PPARalpha. No remarkable sex difference was observed in induction of peroxisome proliferation, as measured morphologically, but a markedly higher induction of several enzymes and PPARalpha protein and mRNA was found in males. On the other hand, trichloroethylene induced liver cytochrome P450 2E1, the principal enzyme responsible for metabolizing trichloroethylene to chloral hydrate, only in males, which resulted in similar expression levels in both sexes after the treatment. Trichloroethylene influenced neither the level of catalase, an enzyme involved in the reduction of oxidative stress, nor aldehyde dehydrogenase, the main enzyme catalyzing the conversion to trichloroacetic acid. These results suggest that trichloroethylene treatment causes a male-specific PPARalpha-dependent increase in cellular oxidative stress.

Animals↗

PubMed2000

Cardiovascular response and stress reaction to flumazenil injection in patients under infusion with midazolam.

OBJECTIVES: To evaluate the cardiovascular response and acute stress reaction after arousal induced by a benzodiazepine antagonist, flumazenil, in patients sedated with midazolam. DESIGN: Prospective study. SETTING: Emergency center in a university hospital. PATIENTS: A total of 12 patients were ventilated mechanically under sedation with midazolam. INTERVENTIONS: We monitored the consciousness level, heart rate, systemic blood pressure, pulmonary artery pressure, and pulmonary artery occlusion pressure before and after a bolus injection of 0.5 mg of flumazenil. The score for the consciousness level represents the sum of the scores for eye opening and best motor response, as determined by the Glasgow Coma Scale. We measured the cardiac output, concentrations of norepinephrine, epinephrine, and 3-methoxy-4-hydroxyphenylethyleneglycol in plasma, and concentration of cortisol in serum. We calculated the left ventricular ejection fraction, cardiac index, systemic vascular resistance index, pressure-rate product, systemic oxygen delivery, and systemic oxygen consumption at 0, 10, 30, and 60 mins after injection of flumazenil. MEASUREMENTS AND MAIN RESULTS: The serum benzodiazepine's receptor binding activity in serum was in the range from 50 to 1000 ng/mL before injection of flumazenil. Flumazenil improved the consciousness level from 6.7+/-2.0 to 8.9+/-1.6 and induced transient elevations in heart rate, blood pressure, systolic pulmonary artery pressure, and pulmonary artery occlusion pressure. Left ventricular ejection fraction, oxygen delivery index, and pressure-rate product increased significantly, from 61%+/-8%, 640+/-170 mL/min/m2, and 13,300+/-2600 mm Hg/min at 0 mins to 67% +/-5%, 710+/-220 mL/min/m2, and 16,500+/-4400 mm Hg/min at 10 mins, respectively. Concentrations of norepinephrine and epinephrine in plasma increased significantly, from 890+/-840 pg/mL and 220+/-360 pg/mL, respectively, at 0 mins to 990+/-850 pg/mL and 270+/-300 pg/mL, respectively, at 10 mins. There were no significant changes in the plasma concentration of 3-methoxy-4-hydroxyphenylethyleneglycol, the serum concentration of cortisol after the administration of flumazenil. CONCLUSIONS: Flumazenil did not result in a significant acute stress reaction in midazolam-sedated patients, but it increased myocardial oxygen consumption by enhancing sympathetic nervous activity or antagonizing cardiovascular depression induced by midazolam.

Acute Disease↗

PubMed2000

Plasma lactate concentration and muscle blood flow during dynamic exercise with negative-pressure breathing.

This study assessed the hypothesis that increasing cardiac filling pressure (CFP) would enhance contracting muscle blood flow (MBF) by stretching cardiopulmonary baroreceptors and attenuate the increase in plasma lactate concentration ([Lac(-)](p)) during dynamic exercise. Continuous negative-pressure breathing (CNPB) (-15 cmH(2)O) was used to increase the CFP by accelerating the venous return to the heart. In the first series of experiments, 10 men performed a graded exercise seated on a cycle ergometer with (N1) and without CNPB (C1). The increase in [Lac(-)](p) for N1 was attenuated at 60%, 90%, and 100% of maximal exercise intensity compared with that in C1 (P < 0.001). Also, the increases in mean arterial pressure (MAP) and plasma catecholamine concentrations were attenuated in N1 compared with those in C1 throughout the graded exercise (P < 0.05). However, heart rate and pulse pressure were not significantly influenced by CNPB. Second, we studied the impact of CNPB on forearm MBF during a rhythmic handgrip exercise in 5 of the 10 subjects. Forearm MBF was measured immediately after cessation of the exercise by venous occlusion plethysmography at rest, 30%, 50%, and 70% of maximal work load (WL(max)) with (N2) and without CNPB (C2). Forearm MBF and vascular conductance for both trials increased with the increase in intensity, but forearm skin blood flow measured by laser-Doppler flowmetry remained unchanged. MBF and vascular conductance in N2, however, increased more than in C2 at every intensity (P < 0.01) except for MBF at 70% WL(max), whereas the increase in MAP for N2 was attenuated compared with that in C2 (P < 0.05). Thus augmented active muscle vasodilation occurred in N2 with a lower increase in MAP compared with that in C2. These findings suggest that the stretch of intrathoracic baroreceptors, such as cardiopulmonary mechanoreceptors, by CNPB increased MBF by suppressing sympathetic nerve activity. The attenuation of the increase in [Lac(-)](p) might be caused, at least partially, by the increased MBF.

Adult↗

PubMed2000

Massive noninflammatory periportal liver necrosis following concentrated acetic acid ingestion.

In a fatal occurrence of massive liver necrosis following ingestion of concentrated (90%) acetic acid, the patient showed evidence of hemolysis, disseminated intravascular coagulation, and liver dysfunction at only 45 minutes after exposure. With refractory to vigorous supportive care, the patient s condition deteriorated until death occurred 39 hours after ingestion, despite some improvement of coagulopathy. Autopsy revealed corrosive injuries in the upper gastrointestinal tract and massive hepatic necrosis in a periportal distribution without significant inflammation. A direct effect of the noxious agent on hepatocytes involving the portal circulation is suggested.

Acetic Acid↗

PubMed2000

Myocardial infarction with acute insulin poisoning--a case report.

A 36-year-old woman without overt coronary risk factors was admitted to hospital with coma about 9 hours after mass self-injection of insulin (1,500 units). Laboratory investigation revealed severe hypoglycemia and hyperinsulinemia. During the treatment of her hypoglycemia, circulatory collapse occurred. The ECG, echocardiogram, and elevation in troponin T suggested a diagnosis of myocardial infarction. Although the patient became apallic and developed systemic spasticity due to hypoglycemic brain damage, her hemodynamics improved with supportive care alone. Coronary angiography and myocardial scintigraphy performed later demonstrated a broad area of myocardial damage despite intact coronary artery circulation. The authors hypothesize that temporary coronary arterial narrowing or coronary arterial vasospasm induced by severe hyperinsulinemia contributed to the pathogenesis of the myocardial infarction. The possibility of myocardial infarction should be considered in patients with acute insulin poisoning.

Adult↗

PubMed2000

[A case of intrathoracic schwannoma derived from the left vagus nerve].

We report a case of schwannoma asymptomatic for 9 years, derived from the left vagus nerve in the middle mediastinum. This spindle-shaped tumor caused paralysis of the left recurrent nerve as an initial clinical manifestation with cough. T2-weighted magnetic resonance imaging (MRI) showed a neurogenic tumor with a characteristic target appearance and with constituents of different intensities: mucinous material in the peripheral zone and solitary tissue in the central zone. But, this different intensity is not directly reflected by the histopathologic features of Antoni types A and B. These findings suggest that MRI is useful for determining the parent nerve of a neurogenic tumor and is helpful for the diagnosis.

Adult↗

PubMed1999

Internal carotid-posterior communicating artery aneurysm associated with unusually short posterior communicating artery.

We report two cases of a ruptured internal carotid-posterior communicating artery aneurysm in which the ipsilateral posterior communicating artery is short and the P1 and P2 segments of the posterior cerebral artery are long. Unique angiographic and operative findings are described. Vertebral angiography with carotid compression is recommended to diagnose this rare variation. Recognition of this variation is important to avoid an inadvertent occlusion of arteries behind the aneurysm at the time of clipping. Copyright 1999 Harcourt Publishers Ltd.

Journal Article↗

PubMed1999

Effect of charcoal hemoperfusion on clearance of cibenzoline succinate (cifenline) poisoning.

BACKGROUND: Management of cibenzoline succinate (cifenline) poisoning by symptomatic treatment is recommended because it has been reported cibenzoline succinate is not effectively removed by hemodialysis. The use of charcoal hemoperfusion for patients with cibenzoline succinate poisoning has not been reported previously. CASE REPORT: An 80-year-old woman with permanent right ventricular pacing was admitted to our hospital with general fatigue and clouding of consciousness. She had been receiving cibenzoline succinate for 1 month. The patient was clearly in shock on admission. Electrocardiogram showed a prolonged QRS and QTc interval and pacing failure. Hemodynamic failure, electrocardiographic abnormalities including pacing failure, and liver and renal dysfunction were compatible with cibenzoline succinate poisoning. Symptomatic treatment was provided. On day 4, charcoal hemoperfusion was initiated because of the development of hypoglycemia accompanied by liver and renal dysfunction. After charcoal hemoperfusion, the hypoglycemia, liver and renal dysfunction, prolonged QRS and QTc interval, and pacing threshold resolved. She was discharged on digoxin. We present a case of cibenzoline succinate poisoning treated with charcoal hemoperfusion which resulted in a rapid reduction of cibenzoline plasma concentrations with a significant clinical improvement.

Aged↗

PubMed1999

Rabbit syndrome following phenol ingestion.

CASE REPORT: An elderly Japanese woman ingested a massive quantity of phenol in a suicide attempt. She was admitted to the Emergency Department in respiratory arrest and deep coma. Duodenogastritis was evident endoscopically. With the return of spontaneous respiration and consciousness, fine, rapid rhythmic perioral movements developed together with Parkinsonian findings. The abnormal movements were aggravated by administration of a neuroleptic and ameliorated by discontinuing the drug; they disappeared completely by hospital day 15. In addition to neuroleptic drugs, phenol intoxication may cause the rabbit syndrome by inducing cholinergic dominance with relative dopamine hypofunction in the central nervous system.

Aged↗

PubMed1999

A case of serious organophosphate poisoning treated by percutaneus cardiopulmonary support.

We report a case of respiratory arrest, refractory circulatory collapse, and severe hypothermia following ingestion of an organophosphate insecticide. In addition to conventional management, including mechanical ventilation, administration of vasopressors, enteral lavage, charcoal hemoperfusion and administration of antidotes, extracorporeal cardiopulmonary support in the form of percutaneous cardiopulmonary support was successfully employed. Percutaneous cardiopulmonary support may be used for severe but potentially reversible pulmonary or cardiovascular toxicity induced by organophosphates as well as complicated severe hypothermia.

Extracorporeal Circulation↗

PubMed1999

Severe rhabdomyolysis following massive ingestion of oolong tea: caffeine intoxication with coexisting hyponatremia.

A 36-y-o patient with schizophrenia, who had consumed gradually increasing quantities of oolong tea that eventually reached 15 L each day, became delirious and was admitted to a psychiatric hospital. After abstinence from oolong tea his delirium resolved. He was transferred to our hospital when he was discovered to have acute renal failure with hyponatremia (118 mEq/L) and severe rhabdomyolysis (creatine phosphokinase, 227,200 IU/L). On admission rhabdomyolysis had begun to improve despite a worsening of the hyponatremia (113 mEq/L). With aggressive supportive therapy, including hypertonic saline administration and hemodialysis, the patient fully recovered without detectable sequelae. The clinical course suggests that caffeine, which is present in oolong tea, was mainly responsible for the rhabdomyolysis as well as the delirium, although severe hyponatremia has been reported to cause rhabdomyolysis on rare occasions. We hypothesize that caffeine toxicity injured the muscle cells, which were fragile due to the potassium depletion induced by the coexisting hyponatremia, to result in unusually severe rhabdomyolysis. The possibility of severe rhabdomyolysis should be considered in a patient with water intoxication due to massive ingestion of caffeine-containing beverages.

Acute Kidney Injury↗