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Biomedical subjects

M Hatta

Publications and source records attributed to M Hatta.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Sutureless aortic valve replacement for peri-annular pseudoaneurysm and perivalvular leakage due to prosthetic valve endocarditis].

A 49-year-old man who had undergone AVR entered our hospital with congestive heart failure and continuing slight fever. By cardiac imaging, he was diagnosed prosthetic valve endocarditis with periannular pseudoaneurysm and perivalvular leakage. He underwent a new translocation method using a composite valve (a prosthetic valve directly sutured a ring prosthesis, which was separated from an intraluminal ringed graft). Post operative course was uneventful. He recovered well after the operation.

Aneurysm, False↗
PubMed1992

Preparation and pharmacological evaluation of 4-(1,4-benzoquinon-2-yl)-4-phenylbutanamides as potential cerebral protective agents.

A new series of 4-(1,4-benzoquinon-2-yl)-4-phenylbutanamides (2) were synthesized for evaluation of their pharmacological activities. All these compounds synthesized showed significant antilipidperoxidation (ALP) activities with brain homogenate in rats and some of them possessed a protective effect against hypobaric hypoxia in mice. Especially, a thiomorpholine derivative (2l, SUN-4757) showed a wide efficacy spectrum to a variety of experimental screening assays designed for cerebral protective agents, and it had a high LD50 value.

Animals↗
PubMed1992

[EEG findings in hip fracture of the elderly].

Twenty three patients with hip fractures, over 70 years old of age, who had surgical treatment and medical rehabilitation in the Yokufukai Geriatric Hospital were studied to evaluate changes of EEG findings at the time of hip fracture. In all cases, the pre-fracture ambulation status were independent. EEG findings were graded as normal, abnormal (minor degree, moderate-to-severe degree) and states of ambulation after hip fracture were graded good or poor. Good ambulation was defined as total independence and poor ambulation was defined as dependent on assistance or bedridden. In 11 cases of good ambulation, nine had an EEG which was normal or abnormal to a minor degree during pre- and post-fracture periods. In 12 cases of poor ambulation, seven had an EEG which was normal or abnormal to a minor degree in the pre-fracture period, but in the post-fracture period, only two of them were in the same grade and five showed moderate-to-severe abnormal EEG findings. Five out of 12 cases of poor ambulation demonstrated moderate-to-severe EEG abnormality in pre- and post-fracture periods. The present study suggests that the response to hip fractures in the elderly are divided into two types based on their brain functions. One group can maintain good brain function immediately after hip fractures, while the other can not maintain sufficient brain function and lose their ambulatory ability.

Aged↗
PubMed1991

Genomic organization and chromosomal mapping of the mouse P-cadherin gene.

Cadherins are a family of Ca(2+)-dependent cell adhesion molecules, that includes P-cadherin, E-cadherin, N-cadherin and L-CAM. In this study, the genomic organization of the mouse P-cadherin gene was determined by analyzing overlapping DNA clones obtained from a mouse genomic library. The results showed that this gene spans over 45 kb and consists of 15 exons. A marked feature of this gene is that the first intron is 23 kbp long accounting for half its length. Comparisons of this structure with that of L-CAM, a chicken cadherin, revealed that the exon-intron boundaries are conserved between the two genes except that the P-cadherin first exon includes the correspoding first and second exons of the L-CAM gene. This gene was also similar to the other in that the second intron, which corresponds to the P-cadherin first intron, is exceptionally longer than other introns. These results suggest that the exon-intron pattern conserved in these genes is of significance for generation of domain structure of cadherin molecules or for their transcriptional regulation. We also determined the chromosomal localization of the P-cadherin gene by interspecific backcross analysis, and found that this gene is located in the central region of mouse chromosome 8 and linked with the E-cadherin locus. This is the first evidence for the linkage of different cadherin genes.

Amino Acid Sequence↗
PubMed1989

Neural cadherin: role in selective cell-cell adhesion.

Cadherins are a family of Ca2+-dependent intercellular adhesion molecules. Complementary DNAs encoding mouse neural cadherin (N-cadherin) were cloned, and the cell binding specificity of this molecule was examined. Mouse N-cadherin shows 92 percent similarity in amino acid sequence to the chicken homolog, while it shows 49 percent and 43 percent similarity to epithelial cadherin and to placental cadherin of the same species, respectively. In cell binding assays, mouse N-cadherin did not cross-react with other mouse cadherins, but it did cross-react with chicken N-cadherin. The results indicate that each cadherin type confers distinct adhesive specificities on different cells, and also that the specificity of N-cadherin is conserved between mammalian and avian cells.

Amino Acid Sequence↗
PubMed1989

[The relationship between the physical features and medications in Reye-like syndrome in elderly patients].

With the increase in the aged population, it is expected that the number of debilitated aged people will increase and that the number of patients receiving many medications will increase. However, there have been few reports of clinical pharmacological studies on blood pharmacokinetics, metabolism, adverse effects, etc, of drugs used in debilitated aged people who have lowered physical and mental functions complicated by many diseases. Thus, for the large part, pharmacokinetics in these patients remains unelucidated. We experienced eight cases of marked hypoglycemia of unknown cause in patients who had not taken any hypoglycemic drugs or insulin and examined the relationships between the event and the physical features and medications of the patients. The eight patients included both males and females aged 66 to 88 years (mean: 78.5 years). The eight patients were all aged and showed cerebral infarction, reduced volition, etc. The onset of hypoglycemia was preceded by decreased appetite and an abrupt manifestation of severely disturbed consciousness a few days previously. Laboratory tests revealed marked hypoglycemia in 8 cases, leucocytosis in 7 cases (not examined in one case), metabolic acidosis in 3 cases, elevated GOT in 5 cases, elevated GPT in 2 cases, increased BUN in 1 case, and positive CRP in 4 cases. The patients had been taking an agent to activate brain metabolism/improve mental symptoms (Hopantene calcium: 7 cases; Idebenone: 1 case). The Idebenone-treated patient had received Hopantene calcium for eleven months prior to receiving Idebenone. Furthermore, the findings resembled those of Reye's syndrome often noted in children.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

General pharmacological studies on N-(2,6-dimethylphenyl)-8-pyrrolizidineacetamide hydrochloride hemihydrate. 1st communication: effect on the central nervous system.

The pharmacological actions of N-(2,6-dimethylphenyl)-8-pyrrolizidineacetamide hydrochloride hemihydrate (SUN 1165), a new antiarrhythmic agent, on the central nervous system were studied in various experimental animals as compared with those of disopyramide, mexiletine and lidocaine, and the following results were obtained. 1. Acute toxicity of SUN 1165 in mice was similar to that of mexiletine, and twice as potent as compared with that of disopyramide and lidocaine. Main acute toxic symptoms of SUN 1165 were muscle relaxation, ataxia, clonic convulsions, tremor and a decrease in spontaneous activity in mice, rats and rabbits. In addition to these symptoms, vomiting in dogs was observed. These toxic symptoms were similar to those of lidocaine. In the case of disopyramide, ataxia, tremor and a decrease in spontaneous activity were observed in mice and rats. On the other hand, mexiletine caused central nervous excitatory symptoms, that is, tremor, Straub tail, clonic convulsions, jumping, running and opisthotonus in mice and rats, and vomiting in dogs. 2. SUN 1165 even at large doses (50-100 mg/kg p.o.) exerted no significant effects on the following changes: hexobarbital-induced induced hypnosis, oxotremorine-induced tremor, apomorphine-induced hypothermia, reserpine-induced ptosis and hypothermia, 5-hydroxytryptophan syndrome and fighting behavior in mice, and conditioned avoidance response in rats. 3. An ineffective dose of SUN 1165 (12.5 mg/kg p.o.) on spontaneous locomotor activity was lower than of disopyramide and lidocaine, however, higher than that of mexiletine. 4. SUN 1165 at large doses showed antagonistic action on toxic extensor seizures induced by maximal electroshock, picrotoxin, or strychnine in mice, but anticonvulsive effects of SUN 1165 were less potent than those of mexiletine and lidocaine. SUN 1165 had no effect on clonic convulsions induced by pentetrazol and pictrotoxin in mice, while both mexiletine and lidocaine prolonged the duration of clonic convulsions. 5. The muscle relaxant effect of SUN 1165 (50%-toxic dose, TD50 = 30 mg/kg p.o.) was more marked than that of lidocaine (TD50 = 92 mg/kg p.o.) on traction test in mice. However, effect of SUN 1165 (TD50 = 62 mg/kg p.o.) on motor incoordination was similar to that of disopyramide, mexiletine and lidocaine on the rotarod test in mice. 6. The analgesic effect of SUN 1165 was as weak as that of disopyramide, mexiletine and lidocaine on chemically and mechanically-induced pain response in mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1988

General pharmacological studies on N-(2,6-dimethylphenyl)-8-pyrrolizidineacetamide hydrochloride hemihydrate. 2nd communication: effect on the peripheral nervous system and peripheral organs.

The pharmacological actions of N-(2,6-dimethylphenyl)-8-pyrrolizidineacetamide hydrochloride hemihydrate (SUN 1165), a new antiarrhythmic agent, on the peripheral nervous system and peripheral organs were studied in various laboratory animals in comparison with those of disopyramide and mexiletine, and the following results were obtained. 1. Large doses (50 or 100 mg/kg p.o.) of SUN 1165 as well as mexiletine had little effects on the pilocarpine-induced hypersalivation and the pupil size in mice. At higher concentration (10(-5) g/ml), SUN 1165 had no effects on the various spasmogen acetylcholine (ACh)-, histamine- or BaCl2-induced contractions in the isolated guinea pig ileum, tracheal smooth muscle and urinary bladder. Disopyramide caused mydriasis, inhibited the pilocarpine-induced hypersalivation at antiarrhythmic doses (10-30 mg/kg p.o.), and suppressed ACh-induced contractions in the various organs. 2. SUN 1165, like disopyramide and mexiletine, decreased the contractile amplitude and diastolic tone of the isolated rabbit ileum. SUN 1165 as well as disopyramide had no effect on the intestinal propulsion even at a large dose (100 mg/kg p.o.). Mexiletine inhibited it at antiarrhythmic doses (10-30 mg/kg p.o.). SUN 1165 only at a large dose (100 mg/kg i.d. or p.o.) inhibited volume of pepsin output in the gastric juice in pylorus-ligated rats and caused a damage to the gastric mucosa. 3. SUN 1165, like disopyramide and mexiletine, slightly potentiated the norepinephrine-induced contraction of the rat vas deferens in vitro. Moreover, SUN 1165 as well as disopyramide and mexiletine slightly potentiated the serotonin-induced contraction of the rat isolated fundus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

[Historical course of surgery in rectal cancer in Japan].

Rectal cancer surgery in Japan started to first step of Lisfranc type resection by T. Sato in 1887. Since H. Ito (1902) published in success of three cases of abdominosacral excision (ASE), ASE occupied the main position of rectal cancer surgery in Japan. In 1944, however, M. Kuru reported the superiority of abdominoperineal resection (APR), an orient of surgery had changed to APR from ASE with time. His operative mortality was 2.0% or less, and 5-year survival rate was more than 50%. D. Jinnai (1961) introduced endorectal pull-through operation, and in 1972 he exhibited an excellent survival and satisfying function following sphincter preserving operation, such as anterior resection and pull-through, for mid and upper rectal cancer. T. Kajitani (1975) and Y. Koyama (1977) improved the survivals through an extended pelvic nodes dissection. Today, the principle of rectal cancer surgery in Japan is a limited resection for early cancer, sphincter preserving operations for upper and mid-rectal cancer and extended pelvic nodes dissection for advanced lower rectal cancer.

Autonomic Nervous System↗
PubMed1985

Hemorrheological effects of colloidal plasma substitutes infusion. A comparative study.

Our objective was to investigate experimentally the easily overlooked effect of the clinical use of colloidal plasma substitutes on tissue perfusion. The experimental animals were dogs, and the study was carried out using several independent rheological experimental methods. The following are the principal findings: 1) Based on the observations made under a microscope, the stability of blood suspensions was best maintained by dextran-40 (Dex 40) and hydroxyethyl starch (HES0.55; Hespander), both of which cause little rouleaux formation by erythrocytes. In addition, the electronegativity of the erythrocyte membrane was simultaneously elevated. 2) The blood viscosity was greatly affected by the hematocrit and the serum protein concentration. 3) At a high shear rate, the blood viscosity among these colloidal plasma substitutes showed no great difference after infusion; in contrast, at a low shear rate, the blood viscosity after infusion of Dex 40 or HES0.55 was lower than after other substitutes. 4) The ratio of the viscosity at a low shear rate to the viscosity at a high shear rate is more significant and useful as a clinical indicator. On the basis of the preceding findings, Dex 40 and HES0.55 were generally superior to the other substitutes, especially HES0.55.

Blood Proteins↗