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Biomedical subjects

H Nagao

Publications and source records attributed to H Nagao.

At least 19 recordsLinked to original sources
PubMed1992

Tea catechins decrease micellar solubility and intestinal absorption of cholesterol in rats.

A(-)-epicatechin (EC) and (-)-epigallocatechin (EGC) mixture and a mixture of their gallates (ECG and EGCG, respectively) markedly lowered lymphatic cholesterol absorption in rats with a cannulated thoracic duct. A mixture of ECG and EGCG was more effective in reducing cholesterol absorption than the EC and EGC mixture. These catechins also tended to decrease lymphatic absorption of triacylglycerols, although not so pronounced as in cholesterol absorption. An in vitro study on micellar solubility of cholesterol showed that these catechin mixtures precipitated cholesterol solubilized in mixed bile salt micelles in a dose-dependent manner. A mixture of ECG and EGCG more effectively precipitated micellar cholesterol than a mixture of EC and EGC. When purified EC, EGC, ECG and EGCG were used, EGCG was more effective in precipitating micellar cholesterol than ECG. The effect of EC and EGC was comparable and weaker than their gallate esters. The bile acid concentration in the micelles was not affected by these catechins. A positive correlation was observed between the amount of coprecipitated EGCG and cholesterol. These results clearly show that tea catechins, in particular their gallate esters, effectively reduce cholesterol absorption from the intestine by reducing solubility of cholesterol in mixed micelles. The observation accounts for the hypocholesterolemic effect of tea catechins.

Animals↗
PubMed1992

MRI in poliomyelitis-like syndrome.

We report the MRI findings in a patient with poliomyelitis-like syndrome. MRI demonstrated a lesion extending from the dorsal region of the pons to the upper level of the thoracic spinal cord. The spinal cord was particularly affected in a region involving the bilateral anterior horns. Although its pathology is unknown, the lesion of the spinal cord seemingly reflects the pathological features of this disease.

Humans↗
PubMed1992

Three types of hyperthermic seizures in rats.

Three types of rat hyperthermic seizures were observed. The first comprised generalized clonic convulsions preceded by intermittent myoclonus. Ictal EEG showed diffuse intermittent spikes and sequential rapid spike-wave bursts (type 1 seizures). In the other types of seizures, the paroxysmal discharges originated in the occipital region without (type 2a seizures) or with (type 2b seizures) secondary generalization. Type 2a seizures involved no convulsive movement whereas type 2b seizures involved clonic convulsions. The threshold temperatures for type 1, 2a and 2b seizures were 44.1 +/- 0.60, 40.9 +/- 1.47 and 42.1 +/- 0.75 degrees C, respectively. Of these seizures, the type 2 seizures (2a and 2b) did not severely affect the general condition of rats and thus may be an appropriate model for the investigation of febrile seizures.

Animals↗
PubMed1992

A female patient with Lesch-Nyhan syndrome.

The authors report the second case of a female with typical Lesch-Nyhan syndrome. She exhibited athetoid movement, self-multilation, mental retardation and spasticity. Laboratory investigations revealed hyperuricaemia, hyperuricosuria and decreased erythrocyte hypoxanthine guanine phosphoribosyl transferase activity. She has normal female external genitalia and karyotype. Her parents are non-consanguineous and there is no family member with gout, nephropathy or any psychoneurological disorder. To prevent self-stimulation, it was necessary to fix the patient's upper extremities to the backrest of her wheelchair. The authors also describe an apparatus that limits elbow flexion.

Child↗
PubMed1992

[Neurophysiologic and histopathologic studies in a case of congenital sensory neuropathy with anhidrosis].

A three year-old boy with congenital sensory neuropathy with anhidrosis (CSNA) was described. Sural nerve biopsy specimens revealed an almost complete absence of unmyelinated fibers and a marked decrease of the density of small myelinated fibers with preservation of the density of large myelinated fibers. No evidence of active degeneration of unmyelinated or myelinated fibers was found. Skin biopsy specimens revealed the absence of nerve terminals and fibers innervating sweat glands, although sweat glands seemed to be apparently normal in their morphological findings. Therefore, it was concluded that the absence of pain and temperature sensations with preservation of touch sensation in our patient was compatible with the morphometric findings of nerve fibers of the sural nerve described. Similarly anhidrosis was concluded to be well explained by the absence of the innervation of sweat glands and the vessels around them. On the other hand, electrophysiologic studies, such as motor and sensory nerve conduction, short latency somatosensory evoked potential and auditory brainstem response, in which the function of the large myelinated fibers is presumably tested, were all normal. Therefore, the structure and function of such large myelinated fibers were spared in this case. From clinical viewpoints, electrophysiologic studies described above are useful to differentiate CSNA from other types of congenital sensory neuropathies, in which large myelinated fibers are affected.

Electrophysiology↗
PubMed1992

[The first case of infantile type neuronal ceroid-lipofuscinosis in Japan].

We reported the first case of typical infantile-type neuronal ceroid-lipofuscinosis (INCL) in Japan. The patient was a 1-year-old girl presenting with rapidly progressive psychomotor deterioration and blindness. Muscular hypotonia, microcephaly and myoclonic jerks became marked with the progression of her disease. Diminution in amplitude of EEG, VEP and ERG was prominent in the initial stage, but ABR was normal. MRI showed progressive brain atrophy. Electron microscopic examination of the biopsied skin revealed granular matrix, the specific inclusion bodies, in the epithelial cell of sweet glands. Many sea-blue histiocytes were demonstrated in her bone marrow samples. INCL is a common progressive encephalopathy in the Scandinavian countries, but a typical case had not yet been fully reported in Japan. This prompted us to report our case. Future reports are need for the study of INCL in Japan.

Biopsy↗
PubMed1992

[Clinical evaluation of prostaglandin E1 during anesthesia in non-elderly and elderly patients].

The effects of prostaglandin E1 (PGE1) on blood pressure during anesthesia and the postoperative changes in organ functions were examined and compared in 358 cases. Two hundred and eighty patients were under 64 years of age and 128 patients were over 65 years. It was possible to control blood pressure satisfactorily with PGE1 in both non-elderly and elderly groups. However in the elderly group, it was more difficult to control blood pressure with PGE1 under NLA as compared with enflurane anesthesia. In both groups, urinary flow increased during and after the administration of PGE1, and the livers and kidneys showed neither dysfunction nor deterioration after operation. We had very few incidences of side effects with this drug. PGE1 is also considered safe and useful for elderly people during and after surgery.

Adolescent↗
PubMed1991

Structure/activity relationship of eel calcitonin. A study using a newly devised method for designing analogs.

A series of analogs of eel calcitonin (eCT) was synthesized according to a newly devised scheme, 'the insertion-inactivation method', to clarify the structure/activity relationship of a given peptide. This method consists of two steps: the deletion of a residue of the peptide is first chosen and then a series of analogs with the residue reinserted into serial positions is synthesized and biological activities are assessed in each step. An analog lacking Lys18 (dK), selected as a deleted analog for the first step, showed marked loss of activities determined by inhibition of 125I-eCT binding, growth inhibition, and cAMP production in a porcine kidney cell line LLC-PK1. Activities of a set of 20 analogs with the reinserted lysine residue at serial positions from 12 to 32 (K12-K32) were then evaluated. The results showed the following three patterns of the expression of activities according to the position of the reinsertion: (a) analogs K12-K16 (positions 12-16) and K25 (position 25) showed lower activities than eCT in all assays; (b) K17-K24 (positions 17-24) showed slightly lower activities than eCT in the receptor binding and the growth inhibition and similar level in cAMP production; (c) K26-K32 (positions 26-32) showed considerably lower activities in the former two assays and slightly lower activity in cAMP production. Further, analogs considerably less active than eCT showed unchanged alpha-helix contents and destroyed amphiphilicity by the insertion of a lysine residue, indicating that amphiphilicity is one of important factors for expressing the activity. The results obtained here lead to a conclusion on the significance of each region of eCT molecule as follows: (a) the presence of Lys18 is necessary for the complete expression of biological activity; (b) the length of amphiphilic alpha-helix to be required for the activity is at most 10 residues ranging from position 8 to position 17; (c) the receptor binding region is located within 9 residues ranging from position 24 to position 32.

Amino Acid Sequence↗
PubMed1991

[A case of Behçet's disease complicated with acute myocardial infarction].

A 23-year-old-man was admitted to our department complaining of chest oppression. He had had a diagnosis of intestinal-Behçet because of a 7-year history of recurrent oral and genital ulcers, arthritis, cutaneous folliculitis and ulcer in the ileocecal region. Cardiac catheterization revealed total occlusion at the proximal portion of the left anterior descending artery (LAD) without aneurysm formation at other coronary trees. During medical follow-up, this case showed vasospastic angina probably associated with active coronary vasculitis. The incidence of vascular involvement in the total number of cases of Behçet's disease reported in the literature is 3.6-7.7%. Overall, thrombophlebitis and arterial aneurysm formation is relatively common and frequently reported in cases of vasculo-Behçet. Our case demonstrated the following uncommon pattern as vasculo-Behçet; 1) initial clinicopathologic manifestation at the coronary artery without any other vascular lesion, 2) abrupt total occlusion (clear cut lesion) at LAD, 3) complication of vasospastic angina, which has not yet been reported in medical literature.

Adult↗
PubMed1991

[Magnetic resonance imaging of skeletal muscle in patients with Duchenne muscular dystrophy--serial axial and sagittal section studies].

Magnetic resonance imaging of skeletal muscles in thirteen patients with Duchenne muscular dystrophy was performed to estimate pathological changes. Serial axial and sagittal sections of the right lower extremity were recorded. In the early stage, the T1 values of gastrocnemius and soleus muscles were slightly lower than the control values, and in the late stage, the values were much lower in all muscles examined. In sagittal sections, the gastrocnemius muscles in the early stage showed a high density area at the distal region adjacent to soleus muscle, and the soleus muscle showed a high density area adjacent to the gestrocnemius muscle. In serial axial sections, high density areas of the anterior and posterior tibialis muscles appeared first at their proximal and peripheral regions. It was concluded that the sequence of appearance of pathological changes was different not only among individual muscles but also among various regions of each muscle; the high density changes appeared first at myotendon junctions.

Adolescent↗
PubMed1990

Hyperthermia-induced seizures with a servo system: neurophysiological roles of age, temperature elevation rate and regional GABA content in the rat.

A servo system including a microwave generator was applied to raise a rat's body temperature at a pre-set rate. Using this system the effects of age and the temperature elevation rate upon febrile seizures in rats were studied. The relationship between the brain GABA content and hyperthermia was also studied. From the results of the present study, the seizure occurrence rate was found to be highest at the age of 20 days, brain damage was speculated to be severe after hyperthermia-induced seizures with a slow temperature rise, and the regional GABA concentration in subcortical structures was found to increase during hyperthermia. These data indicate that a servo system with a microwave generator is useful for experimental febrile convulsions, and that GABA neurotransmission in subcortical structures might contribute to feed-back regulation against seizures during hyperthermia.

Aging↗
PubMed1990

The circadian rhythm of typical absence seizures--the frequency and duration of paroxysmal discharges.

Twelve patients with typical absence seizures, aged five years two months to 10 years, were examined to clarify the circadian rhythm of 3 c/s spike-and-wave paroxysms (s-w paroxysms), by means of video-electroencephalography with telemetry. S-w paroxysms combined with clinical symptoms and continuing for more than four seconds were fewer during the afternoon than the morning and, moreover, during sleep. The correlation ratio between the frequency and duration of s-w paroxysms was r = -0.74, which was statistically significant (p less than 0.02). The duration of s-w paroxysms evoked by hyperventilation or photic stimulation did not differ from that of spontaneous s-w paroxysms. The s-w paroxysms were shorter and deformed in sleep. Therefore, the observation of typical absence seizures during the morning should be regarded as important. In patients with modified s-w paroxysms during sleep, it is important that electroencephalographic recording with stimulation, such as hyperventilation, is performed sufficiently.

Brain↗
PubMed1990

Significant myocardial pathology and increase of alpha 1-adrenergic receptor number affecting the arrhythmogenic condition in cases with ventricular tachycardia.

To study the pathogenesis of idiopathic ventricular tachycardia with left bundle branch block morphology (LBBB-VT), histopathological findings in 34 patients and adrenergic receptor (AR) density obtained by micro-autoradiography in 11 patients were analyzed, using endomyocardial biopsy samples. According to the ventricular volume, we divided the patients into 3 groups. Group A patients (n = 8) were diagnosed as having arrhythmogenic right ventricular dysplasia (ARVD) showing right ventricular enlargement, group B patients (n = 7) showed decreased left ventricular function and/or enlarged left ventricle, and group C (n = 19) included patients with idiopathic ventricular tachycardia (VT) without enlargement or dysfunction of either ventricle. Histologically, there was a high incidence of significant pathology showing myocardial hypertrophy, degeneration, abnormal branching, and interstitial fibrosis in all groups (group A, 100%; group B, 86%; group C, 56%). There was a higher incidence of fatty tissue infiltration in groups A (100%), B (71%), C (48%) than in the control groups. As for AR, specific grains of alpha 1- and beta-AR were 23.0, and 18.3 (grains/25 x 25 mm square) respectively, in patients with LBBB-VT. The number of alpha 1 grains in patients with LBBB-VT was apparently higher than in the control group, sick sinus syndrome (SSS; 11.2), and the beta-AR density in the LBBB-VT group was the same as in the control group (SSS; 15.4). We concluded that the significant pathology in cases with VT might affect the arrhythmogenic condition. Moreover, these results suggested that the increase in the number of alpha 1-AR might have a great influence in idiopathic VT.

Adult↗
PubMed1989

[Direct percutaneous transluminal coronary angioplasty (PTCA) for treatment of acute myocardial infarction: comparison with PTCA immediately after thrombolysis].

We studied 73 patients with acute myocardial infarction (AMI) treated by percutaneous transluminal coronary angioplasty (PTCA) without thrombolysis (direct PTCA) and 52 patients with AMI treated by PTCA immediately after thrombolysis (PTCR + PTCA). The initial results, angiographic findings and preservation of ventricular functions of the direct PTCA group were compared with those of the PTCR + PTCA group. 1. The success rate of coronary recanalization was higher in the direct PTCA group than in the PTCR + PTCA group, but there was no statistical significance (89% vs 77%; p = NS). 2. Major complications occurred in 4.1% of the direct PTCA group and in 5.8% of the PTCR + PTCA group (p = NS). 3. The incidence of acute coronary reocclusion was higher in the PTCR + PTCA group than in the direct PTCA group (7.4% vs 22%; p less than 0.05). 4. Angiographic haziness at the dilated site following PTCA was seen more frequently in patients in the PTCR + PTCA group than in those of the direct PTCA group (43% vs 23%; p less than 0.05). 5. Patients with haziness at the dilated site had a significantly higher incidence of acute coronary reocclusion than did the patients without such haziness (28% vs 6.3%; p less than 0.05). 6. Left ventricular ejection fraction and regional wall motion were better preserved in the direct PTCA group than in the PTCR + PTCA group, but there was not statistical significance. It was suggested that direct PTCA is safe and can be performed with good success rates. It is superior to PTCR + PTCA in avoiding acute coronary reocclusion, and thus we supposed that the response of lesions to angioplasty may be altered by the administration of thrombolytic agents.

Adult↗
PubMed1989

[Effects of early myocardial reperfusion on left ventricular function in patients with acute myocardial infarction].

The effect of early myocardial reperfusion (within six hours after the onset of symptoms) on left ventricular (LV) function in 106 patients with acute myocardial infarction was studied. The subjects consisting of 26 with conventional therapy, 19 with percutaneous transluminal coronary recanalization (PTCR), 16 with percutaneous transluminal coronary angioplasty (PTCA) after PTCR, 32 with direct-PTCA and 13 with coronary artery bypass graft (CABG) were randomly observed after 1981. In these patients, left ventricular ejection fraction (LVEF), regional wall motion, end-diastolic pressure and the contractility index were measured as the indices of LV function. 1. Compared to the conventional therapy group, LVEF and regional wall motion improved significantly in all groups with reperfusion therapy except in the PTCR group. This LV function in patients with subtotal obstruction or good initial collaterals significantly improved compared to patients with total obstruction and no collateral circulation. Patients with a 75 percent or more residual stenosis after reperfusion therapy had significantly decreased LV function compared to those with residual stenosis of less than 75 percent. These findings support the potential role for reperfusion therapy in patients with acute myocardial infarction.

Aged↗
PubMed1989

[Effect of continuous epidural infusion of morphine for postoperative analgesia on pituitary-adrenocortical function].

Plasma levels of cortisol, ACTH and beta-endorphin like immunoreactivity (beta-ELI) were measured to evaluate postoperative pain relief with epidural morphine and systemic analgesics in conjunction with endocrine functions in 16 patients who underwent gastrectomy. Eight of these patients (epidural morphine group) obtained postoperative analgesia with continuous epidural infusion of morphine with a pump as in our previous report. A bolus of epidural morphine was administered through an indwelling thoracic (Th8,9) catheter at 3 hrs prior to the proposed end of the surgery, which was followed with continuous epidural infusion of morphine at a rate of 0.167-0.042 mg.hr-1 with a pump (CADD-PCA, Model 5200P, Pharmacia) during and after anesthesia and surgery with gradual decrease in dose until the third postoperative day. The remaining eight patients (systemic analgesics group) repeatedly received systemic pentazocine and buprenorphine when needed. Plasma cortisol levels increased significantly at the end of surgery and after in both groups. However plasma concentrations of cortisol in the epidural morphine group were significantly lower than those in the systemic analgesics group on the first and second postoperative days. Plasma levels of ACTH and beta-ELI increased significantly at the end of surgery but returned to levels of the previous day in both groups postoperatively. Our study suggests that continuous epidural infusion of morphine is adequate for postoperative pain relief and has suppressing effect on plasma cortisol levels as compared with systemic analgesics regimen.

Adult↗