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Biomedical subjects

S Kikuchi

Publications and source records attributed to S Kikuchi.

At least 325 records · Page 18Linked to original sources
PubMed1993

An anatomic study of foraminal nerve root lesions in the lumbar spine.

An anatomic study of lumbar nerve root lesions in the foraminal zone was performed on 35 cadavers. Two morphologic abnormalities of the nerve roots in the intervertebral foramen were found. The first was an abnormal transverse course of the nerve roots. The second was an indentation on the dorsal root ganglia caused by compression of the superior articular facet, degenerative bulging discs, or both. The incidence of indentation on the dorsal root ganglia was dependent on location of the ganglia or age. For details, at the L5 root level, the ganglia located in the proximal part of neuroforamen had the highest incidence, and extraforaminally located ganglia have the lowest incidence of indentation. The incidence of indented dorsal root ganglia increased with age. The possible correlation between these observed anatomic abnormalities and clinical symptoms must be further elucidate.

Aged↗
PubMed1993

High serum lipoprotein(a) levels are an independent risk factor for cerebral infarction.

BACKGROUND AND PURPOSE: This study was conducted to evaluate the role of high serum lipoprotein(a) levels in a group of patients with a relatively early onset of cerebral infarction as a whole and in a subgroup with the perforating artery occlusion subtype of cerebral infarction. METHODS: Fifty-four patients with cerebral infarction, the onset of which was before age 65 years (37 men, 17 women; mean age, 61.9 +/- 7.7 years) were examined in this study. When patients with atrial fibrillation were excluded to omit cardiac embolic strokes from analysis, the group consisted of 45 patients. The patients were classified into two subtype groups, the perforating artery occlusion group and the cortical artery occlusion group, by using magnetic resonance imaging. Lipoprotein(a) levels were measured by an enzyme-linked immunosorbent assay. Four biochemical variables (serum levels of lipoprotein(a), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides) and other potential risk factors such as hypertension, diabetes mellitus, smoking habits, alcohol intake, and family history were analyzed by stepwise logistic regression to determine the independent and significant risk factors for cerebral infarction without atrial fibrillation. RESULTS: The incidence of subjects with serum lipoprotein(a) levels > or = 42.6 mg/dL, which is the 95th percentile level of the control subjects, was significantly increased in the total cerebral infarction group (P < .025) and the perforating artery occlusion group (P < .025) compared with the control group. In addition, by using stepwise logistic regression analysis in the total and perforating artery occlusion patient groups we identified three independent and significant risk factors: hypertension, a low high-density lipoprotein cholesterol level, and a high serum lipoprotein(a) level. In the cortical artery occlusion group, the sample size was not large enough for the statistical analysis. Diabetes mellitus is the only known factor that correlates with serum lipoprotein(a) levels, but there were no significant correlations between serum lipoprotein(a) levels and history of diabetes mellitus or fasting blood sugar. CONCLUSIONS: These findings indicate that high serum lipoprotein(a) levels are an independent risk factor in the development of cerebral infarction when subjects with atrial fibrillation were excluded from the total group and the perforating artery occlusion subtype group.

Adult↗
PubMed1993

Sudden sensorineural hearing loss associated with slow blood flow of the vertebrobasilar system.

To determine the characteristics of sudden deafness associated with slow blood flow (SBF) within the vertebrobasilar arteries, we evaluated 57 patients with sudden deafness using magnetic resonance imaging (MRI). We detected SBF in 12 (21%) patients, predominantly men over 50 years of age. A second MRI performed in 5 patients 2 months after the onset of symptoms showed recovery of blood flow. All 12 patients complained of vertigo. Audiological and neurotologic tests suggested that hearing loss mainly involved the inner ear. Our findings suggest that unless central lesions are detected, headache, hypoesthesia of the external ear canal, and electronystagmographic abnormalities are signs of SBF. Because sudden deafness may recur in patients who have SBF, they should be monitored and treated to prevent recurrence.

Adolescent↗
PubMed1993

Slow blood flow of the vertebrobasilar system in patients with dizziness and vertigo.

We evaluated 102 patients with dizziness or vertigo who were 50 years of age and over, using magnetic resonance imaging (MRI). Slow blood flow (SBF) in the vertebrobasilar system was detected in 36 patients (35%). The patients with SBF experienced dizziness or vertigo for a longer period than those without SBF. The apogeotrophic type of direction-changing nystagmus was observed in 10 of 36 patients with SBF. No significant differences were found between patients with and without SBF with other neurotological tests. Because MRI can detect both infarcts in the hind-brain and SBF in the vertebral and basilar arteries it is recommended for evaluation of vascular disorders in older patients with vestibular symptoms.

Aged↗
PubMed1993

[Surgical treatment of double-outlet right ventricle with left ventricular outflow tract obstruction].

Three patients with double-outlet right ventricle (DORV) and left ventricular outflow tract obstruction (LVOTO) were described. In each patient, LVOTO was produced by restrictive VSD which resulted from malalignment of the conal musculature and a discrete subaortic membrane. All patients underwent surgical repair with enlargement of the ventricular septal defect and rerouting of the outflow tract from the left ventricle to the aorta. One patient died of congestive heart failure three months postoperatively. Causes of LVOTO and surgical management of DORV with LVOTO were discussed.

Cardiac Surgical Procedures↗
PubMed1993

[A case of constrictive pericarditis--adjuvant techniques of operation and evaluation of the perioperative cardiac function].

A 43-year-old male diagnosed as constrictive pericarditis with dyspnea, fatigability and substantial pericardial calcification on chest roentgenogram underwent pericardiectomy through median sternotomy. The heavily calcified pericardium which was adherent to the anterior and diaphragmatic surface of the heart was successfully resected by the combined use of ultrasonic surgical aspirator (CUSA) and argon beam coagulator (ABC). Intraoperative bleeding was minimal because the adhesion between the pericardium and myocardium, coronary arteries or inferior vena cava were easily dissected with CUSA. Intraoperative hemostasis was also satisfactory with ABC. Perioperative measurements of right ventricular ejection fraction were also effective in evaluating the right ventricular function.

Adult↗
PubMed1993

[A case report of combined aortic and mitral regurgitation associated with ankylosing spondylitis].

We reported a case of ankylosing spondylitis which successfully underwent aortic valve replacement for combined aortic and mitral regurgitation. A 42-year-old man was admitted with symptoms of shortness of breath and anginal pain. He was previously diagnosed ankylosing spondylitis by an orthopedician A grade III/VI to and fro murmur was audible at the left sternal border. Retrograde aortography revealed severe aortic regurgitation and mild mitral regurgitation. Cardiac catheterization showed moderately pulmonary hypertension and high pulmonary artery wedge pressure. He underwent aortic valve replacement with SJM prosthetic valve. His postoperative course was uneventful. In Japan, ankylosing spondylitis is rare disease, and cardiac lesions associated with these conditions is seldom met to us. The surgical problems and management of these lesions are discussed.

Adult↗
PubMed1992

Leukemia inhibitory factor (LIF) mediated increase of choline acetyltransferase activity in mouse spinal cord neurons in culture.

The effects of leukemia inhibitory factor (LIF) on choline acetyltransferase (ChAT) enzyme activity in cultured mouse spinal cord neurons were examined. The administration of LIF to cultures at concentrations of 10 U/ml and higher enhanced ChAT activity approximately 3- to 4-fold in cultured spinal cord neurons. Among neurotrophic factors tested, basic fibroblast growth factor (bFGF) and insulin-like growth factor I (IGF-I) stimulated the development of ChAT activity but to a smaller extent than LIF, while interleukin 3 (IL-3), interleukin 6 (IL-6) and nerve growth factor (NGF) showed no apparent effect on ChAT development. Our results indicate that LIF, which has not been known to have any trophic effect on mammalian central nervous system neurons to date, acts as a potent differentiation factor for ChAT in cholinergic neurons of mouse spinal cord in culture.

Animals↗
PubMed1992

Study of low molecular weight heparin effect on the relation between anticoagulant activity and antithrombin III affinity.

Low molecular weight heparin (FR-860), and conventional unfractionated heparin (UF-heparin) were fractionated by rabbit antithrombin III (AT III)-Sepharose, and the effects of each affinity fraction on the coagulation and fibrinolytic activities were investigated. FR-860 was fractionated to no-affinity, low-affinity (LA) and high-affinity (HA) fractions, and UF-heparin to LA and HA fractions. The HA fractions showed higher activities regarding the prolongation of activated partial thromboplastin time, anti-factor Xa activity and antithrombin activity compared with those of LA. The HA and LA fractions exhibited the enhancement of heparin cofactor II (HC II) activity and fibrinolytic activity in a dose-dependent manner. These results suggest that the antithrombotic activity of FR-860 is exerted through AT III and other mechanism such as HC II-mediated system.

Animals↗
PubMed1992

Recombinant human erythropoietin for autologous blood donation: effects on perioperative red-blood-cell and serum erythropoietin production.

To speed collection of blood for autologous transfusion during elective surgery, patients may be given recombinant human erythropoietin (r-HuEPO). In a controlled trial, we evaluated the effects of r-HuEPO on perioperative red-blood-cell and serum erythropoietin (s-EPO) production in patients donating blood before elective orthopaedic surgery. Patients were assigned randomly to receive no r-HuEPO (12 patients), or 3000 U (4), 6000 U (5), or 9000 U (4) of r-HuEPO intravenously twice a week from the time of the first blood donation. All patients received iron sulphate. 1200 ml blood was collected from each patient in three weekly donations of 400 ml. The 3000, 6000, and 9000 U treatment groups produced 284, 350, and 383 ml, respectively, of red cells during donation, and the untreated controls produced 211 ml. s-EPO concentrations were within the normal range during donation. After surgery, s-EPO concentrations peaked on postoperative day 1 in untreated patients and on day 7 in treated patients; therefore, r-HuEPO may suppress endogenous erythropoietin secretion. Although administration of r-HuEPO increases production of red blood cells, the preoperative anaemia induced by repeated phlebotomy without r-HuEPO may accelerate the postoperative secretion of endogenous erythropoietin.

Adolescent↗
PubMed1992

Improved serodiagnosis of non-A, non-B hepatitis by an assay detecting antibody to hepatitis C virus core antigen.

We examined sequential serum samples from 12 patients with well-characterized posttransfusion non-A, non-B hepatitis who had an acute, resolving self-limited type of clinical course for the presence of antibody to the hepatitis C virus nucleocapsid (core) protein (p22) expressed by a recombinant baculovirus. These sera were simultaneously examined for antibody to the hepatitis C virus nonstructural protein (C100-3) that is presently used for blood screening worldwide. In three patients, both anti-p22 and anti-C100-3 antibodies were detected, but anti-p22 was detected much earlier. In four patients, only anti-p22 was detected. Two other patients were considered to be hepatitis C virus carriers who had been already infected with hepatitis C virus. In one patient, only anti-C100-3 was detected, and it was transient. In two patients, neither antibody was detected. Anti-p22 was detected in at least one of eight samples of transfused blood. Of the nine samples of donated blood that were positive for anti-p22, only four were positive for anti-C100-3. This new assay detecting the antibody to the p22 protein is thus useful for the serodiagnosis of non-A, non-B hepatitis in the acute phase and for blood screening.

Antigens, Viral↗
PubMed1992

Purification and characterization of an unusually large fatty acid synthase from Mycobacterium tuberculosis var. bovis BCG.

Fatty acid synthase was purified from Mycobacterium tuberculosis var. bovis BCG. The method developed gave a 23% yield of the synthase and also yielded purified mycocerosic acid synthase. The fatty acid synthase is of unusually large size and composed of two 500-kDa monomers. The amino acid composition of the two synthases was not identical; the N-terminus of the fatty acid synthase was blocked, whereas that of the mycocerosic acid synthase was not. Western blot analysis of crude mycobacterial extracts with polyclonal antibodies prepared against each synthase showed a single band in each case with no cross-reactivity with the other synthase. Fatty acid synthase required both NADH (Km, 11 microM) and NADPH (Km, 14 microM). The Km for acetyl-CoA and malonyl-CoA were 5 and 6 microM, respectively. Fatty acids were released from the synthase as CoA esters. A bimodal distribution of fatty acids was obtained at around C16 and C26. The primer utilization also reflects the de novo synthesis and elongation capabilities of the enzyme; acetyl-CoA was the preferred primer but CoA esters up to C8 but not C12 and C14 could serve as primers, whereas C16 was readily used as a primer for elongation. Addition of CoA and CoA ester-binding oligosaccharides caused enhanced release of C16. Since this mycobacterial fatty acid synthase is twice as large as other multifunctional fatty acid synthases, it is tempting to suggest that this synthase represents a head to tail fusion of two fatty acid synthase genes coding for a double size protein with one-half producing C16 acid and the other elongating the C16 acid to a C26 acid. The monomer of fatty acid synthase from M. smegmatis was immunologically similar and equal in size to the synthase from M. tuberculosis.

Acetyl Coenzyme A↗
PubMed1992

Impaired NK response of cancer patients to IFN-alpha but not to IL-2: correlation with serum immunosuppressive acidic protein (IAP) and role of suppressor macrophage.

In vitro NK responses of cancer patients (N = 21) to rIFN-alpha A and rIL-2 were examined. The serum concentration of IAP (immunosuppressive acidic protein) was determined in parallel. Five out of seven patients whose serum IAP contents were within the normal range (270 micrograms/ml to 470 micrograms/ml), had their NK activities significantly augmented by rIFN-alpha A and rIL-2. On the other hand, NK cells from ten out of fifteen patients whose serum IAP concentrations were 650 micrograms/ml or more, were not activated by rIFN-alpha A. NK cells of these fifteen patients yet were capable of responding to rIL-2. NK cells from cancer patients, however, became responsive to rIFN-alpha A by either removal of adherent cells or treatment with indomethacin. Therefore, macrophages in PBMC of cancer patients with high serum IAP levels seem to selectively suppress NK response to rIFN-alpha A by an indomethacin-sensitive mechanisms. It was further shown that PGE2 was not the mediator of this suppression.

Adult↗
PubMed1992

[Effect of tranilast, an anti-allergic drug, on the human keloid tissues].

We studied the inhibitory effects of tranilast, an anti-allergic drug, on the human keloid tissues implanted into the dorsal skin of athymic nude mice and on the growth of keloid fibroblast in vitro. In the keloid tissue-implanted model, tranilast (50-200 mg/kg, p.o.) decreased the weight of the keloid tissue as triamcinolone (25 mg/kg, p.o.) did. Tranilast (200 mg/kg, p.o.) reduced the hydroxyproline content of implanted tissues. Tranilast (3-300 microM) also inhibited the collagen synthesis by keloid fibroblast in vitro. Only a high concentration of tranilast (300 microM) suppressed the glycosaminoglycan synthesis and cell proliferation of keloid fibroblasts. Moreover, tranilast scarcely affected the fibronectin production. Triamcinolone (10 microM) also inhibited glycosaminoglycan synthesis and cell proliferation. These results suggest that the inhibitory effect of tranilast on the keloid tissues is related to its inhibition of the collagen synthesis of fibroblasts. Tranilast would be useful as a therapeutic drug for the treatment of keloids.

Animals↗
PubMed1992

[Effect of tranilast, an anti-allergic drug, on carrageenin-induced granulation and capillary permeability in rats].

We studied the effect of tranilast on the growth of carrageenin-induced granulation and the increase in capillary permeability induced by inflammatory agents in rats. In the carrageenin-induced granulation model, tranilast (50 or 100-200 mg/kg, p.o.) decreased significantly and dose-dependently the weight and the hydroxyproline content of the granulation tissue. Tranilast, however, showed no effect on the healing day of locally wounded dorsal skin of rats. Triamcinolone (10 mg/kg, p.o.) also showed an inhibitory effect on the carrageenin-induced granulation model. Tranilast (50-400 mg/kg, p.o.) dose-dependently inhibited the enhancement of capillary permeability induced by the Ca ionophore A23187, bradykinin and xanthine oxidase. Moreover, tranilast (30 and 300 microM) suppressed superoxide production induced by FMLP in human neutrophils, but did not act as a superoxide scavenger. Considering that hypertrophic scar and keloid are conditions characterized by abnormal cell proliferation and excessive collagen accumulation accompanied with itch and pain, these results suggest that tranilast is useful as a therapeutic drug for hypertrophic scars and keloids.

Adult↗