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Biomedical subjects

Y Koike

Publications and source records attributed to Y Koike.

At least 19 recordsLinked to original sources
PubMed1992

Multicentric development of pancreatic intraductal carcinoma through atypical papillary hyperplasia.

We report a case of multiple intraductal carcinomas of the pancreas associated with diffuse atypical papillary hyperplasia. A 67-year-old Japanese man with a complaint of epigastric pain was examined by endoscopic retrograde pancreatography, which demonstrated multiple dilated branches of the pancreatic duct in the body and tail of the pancreas. Histologic examination on the resected pancreas showed diffuse atypical papillary hyperplasia in multiple dilated ducts associated with multiple intraductal carcinomas. Histologic features are described and multicentric carcinogenesis through atypical papillary hyperplasia is discussed.

Aged↗
PubMed1992

Growth of a giant aneurysm following complete thrombosis by detachable balloon occlusion.

A giant basilar artery aneurysm demonstrating growth and causing neurological deterioration even after complete detachable balloon occlusion is reported. Autopsy revealed total thrombosis of the aneurysm and a hemiconcentric, onion skin-like, laminated structure. Numerous vascular channels and multiple fresh intramural hemorrhages were noted within the outer margin of the aneurysmal wall. Repeated intramural hemorrhages appeared to have been responsible for the aneurysmal laminated structure and contributed to progressive aneurysmal growth. This case demonstrates that the growth of some giant aneurysms is not dependent upon the continuity with the parent artery, and progressive enlargement cannot always be prevented by balloon occlusion.

Basilar Artery↗
PubMed1992

Susceptibility to, tolerance to, and physical dependence on ethanol and barbital in two inbred strains of rats.

1. Ethanol-induced sleep time was significantly longer in F344 than LEW rats. However, there is no difference in barbital-induced sleep time between F344 and LEW. 2. Development of tolerance to ethanol-induced motor impairment was slightly faster in F344 than in LEW rats. While, LEW rats more easily developed tolerance to the impairment by barbital in comparison with F344 rats. 3. F344 and LEW rats were chronically treated with liquid diet containing ethanol or with barbital-admixed food. After the termination of ethanol and barbital treatments, various withdrawal signs occurred in F344 rats, including tremor and convulsions, whereas LEW rats showed no convulsions. Withdrawal scores of ethanol and barbital were significantly higher in F344 than in LEW rats. 4. These results suggest that strain differences in physical dependence on ethanol and barbital may be mainly influenced by the susceptibility to ethanol and the development of tolerance to barbital, respectively.

Animals↗
PubMed1992

Sex differences in physical dependence on pentobarbital in four inbred strains of rats.

1. In Lewis (LEW), Fischer 344 (F344), Spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats, pentobarbital (PB)-induced sleep time was much longer in female than in male rats. 2. At the time of awakening, brain levels of PB were significantly higher in the female F344 than in the male rats, but there was no sex differences in other strains. 3. Each strain of rats was treated with PB-admixed food for 47 days. There were significant sex differences in mean drug intake of the SHR and LEW strains, but not the WKY and F344 strains during the final concentration. 4. Only female rats exhibited moderate to severe motor impairment by PB. 5. After PB treatment ended, various signs of PB withdrawal occurred in female, but not male, rats. These marked sex differences were observed in all four inbred strains. 6. The sex differences in physical dependence on PB may be due mainly to differences in rates of drug metabolism for the LEW, SHR and WKY rats, and to differences in CNS sensitivity for the F344 rats.

Animals↗
PubMed1992

Binding parameters of valproic acid to serum protein in healthy adults at steady state.

Two hundred milligrams of valproic acid (VPA) was administered orally to seven healthy adults at 9:00 and 21:00 h for 5 consecutive days, including the morning dose on day 6. On the sixth day, blood samples were drawn at 0, 0.17, 0.33, 0.5, 0.75, 1, 1.5, 3, and 6 h after the morning dose. Binding of VPA to serum protein was evaluated by ultrafiltration, and total and unbound VPA concentrations were determined by fluorescence polarization immunoassay. Binding parameters of VPA to serum protein were calculated for each subject by the Scatchard analysis. The binding parameters obtained from seven subjects showed that the mean association constant (K) was 2.72 x 10(4) L/mol while the total number of binding sites (nPt) was 789 mumol/L. There were marked interindividual variations and the coefficient of variation was 42% for K and 28% for nPt. These results show that endogenous free fatty acids (FFAs) significantly reduce the binding affinity of VPA to serum albumin (p less than 0.05). In addition, they suggest the possibility that the primary binding sites for VPA can be strongly reduced by FFAs. Therefore, we consider that interindividual differences in binding parameters may be clinically important.

Adult↗
PubMed1992

Heterotopic brain tissue of the soft palate.

Heterotopic brain tissue is an unusual substance which is very difficult to diagnose correctly preoperatively. We report on a 7-month-old male infant with heterotopic brain tissue of the soft palate, and describe the results of preoperative examinations including brain scintigraphy, angiography, brain computed tomography and magnetic resonance imaging (MRI). MRI was found useful to show that the tumor had no junction with the intracranial space. The patient was treated successfully without complication or recurrence after 1.5 years follow-up.

Brain↗
PubMed1992

Diagnosis of the ossicular chain in the middle ear by high-resolution CT.

This study was conducted to assess the usefulness and limitations of high-resolution CT for diagnosing the ossicular chain in the middle ear. The CT images in this study were obtained in as much detail as possible and 2 direction images. Preoperative CT findings of the ossicular chain were compared with operative findings in 26 patients with ossicular defects. Preoperative detection of the complete defect of the malleus head and the body and long process of the incus by high-resolution CT was possible in all cases, while detection of the defect of the manubrium of the malleus and superstructure of the stapes could be made in 33.3 and 60%, respectively. The defect of the incudostapedial joint (1 case) and partial defect of the stapes crus (2 cases) could not be diagnosed correctly by preoperative estimation.

Cholesteatoma↗
PubMed1992

Renin inhibitors. II. Synthesis and structure-activity relationships of N-terminus modified inhibitors containing a homostatine analogue.

The synthesis and structure-activity relationships of N-terminus modified renin inhibitors containing the homostatin analogue, (2RS,4S,5S)-5-amino-2-ethyl-4-hydroxy-7-methyloctanoic acid, are described. The compounds having a 3-alkyl (or aryl)sulfonylpropionyl residue at the N-terminus are found to be potent inhibitors which contain two amino acids. (2RS,4S,5S)-N-Isobutyl-5-[N-[(2S)-3-ethylsulfonyl-2-(1- naphthylmethyl)propionyl]-L-norleucyl]-amino-2-ethyl-4-hydroxy-7- methyloctanamide (20) has an IC50 of 0.5 nM against human plasma renin and the oral bioavailability of 20 is 0.73% in rats. Interaction between renin and the N-terminus of 1 and 20 is discussed in molecular modeling studies.

Amino Acids↗
PubMed1992

Renin inhibitors. I. Synthesis and structure-activity relationships of transition-state inhibitors containing homostatine analogues at the scissile bond.

The synthesis and structure-activity relationships of transition-state renin inhibitors containing the homostatine analogues at the scissile bond are described. These inhibitors incorporate the amino acid side chains corresponding to positions 7-12 (P4-P2') of angiotensinogen. Ethyl, 2-hydroxyethyl and 3-hydroxypropyl groups at position 2 of the homostatine analogues (P1') are more effective for increasing potency than the isopropyl group. A combination of residues at P1, P3 and P4 is important for potency and this result suggests that S1, S3 and S4 form a huge hydrophobic core together in renin.

Humans↗
PubMed1992

Dural arteriovenous malformation and sinus thromboses in a patient with prostate cancer: an autopsy case.

A 67-year old man with prostate cancer showed Balint's syndrome, memory disturbance, anosognosia and hallucinations after having been comatose. Radiological findings indicated bilateral dural arteriovenous malformation (DAVM) and thrombosis at the bilateral transverse sinuses and superior sagittal sinus. Pathological findings showed abnormally dilated veins, diffuse neuron loss and gliosis in the parieto-occipital lobe. The chlormadinone and prostate cancer are speculated to have caused the dural sinus thrombosis which probably induced the DAVM.

Adenocarcinoma↗
PubMed1992

A case of anorexia nervosa with acute renal failure induced by rhabdomyolysis; possible involvement of hypophosphatemia or phosphate depletion.

A 16-year-old girl with anorexia nervosa first presented with malnutrition, liver dysfunction, and rhabdomyolysis. Administration of fluid and nutrition saved her from the initial critical state, but acute renal failure followed. Laboratory examination revealed intrinsic renal failure induced by rhabdomyolysis. Latent phosphate depletion and refeeding-induced hypophosphatemia was implicated as the cause of rhabdomyolysis; however coexisting hypotension, dehydration, and liver dysfunction may have contributed to the renal failure. The patient recovered from azotemia by hemodialysis. This is the first reported case of anorexia nervosa with acute renal failure resulting from rhabdomyolysis induced by hypophosphatemia or phosphate depletion.

Acute Kidney Injury↗
PubMed1992

[Conservative treatment of idiopathic facial palsy--effects of the administration of high-dose steroids in Bell's palsy].

The etiology of Bell's palsy is still obscure and its treatment remains controversial. As a conservative treatment for Bell's palsy, Stennert developed a new treatment method for the purpose of improving microcirculation, and reported an extremely high cure rate of 96%, drawing a great deal of attention. However, since the electrophysiological findings and side effects in these patients were not described satisfactorily in his report, this method has not yet come into wide clinical use. In the present study the efficacy of Stennert's method was assessed by electrophysiological examination in patients, and was compared with patients treated by conventional methods. The subjects of this study were 157 patients with Bell's palsy who were treated with a modification of Stennert's method between September 1987 and August 1990. The treatment protocol for the modified Stennert's method was as follows: hydroxyethyl starch 40 with 20% mannitol is given instead of Dextran 40 and prednisolone is stopped depending on the findings of electrical examinations. Fifty-three patients with Bell's palsy treated by the conventional method used in our clinic between November 1983 and August 1987 were used for the control group. The most remarkable difference between these two methods was the initial dose of prednisolone. In the group treated by the modified Stennert's method, 111 patients (70.7%) showed complete recovery within 1 month, and 154 patients presented (98.1%) showed complete recovery within 6 months, 3 cases presented slight sequelae. In the conventional treatment group, on the other hand, only 2 patients (3.8%) recovered within 1 month, and 43 patients (81.0%) recovered within 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Diagnosis of ossicular chain in the middle ear by high-resolution CT].

This study was conducted to assess the usefulness and limitation of high-resolution CT for evaluating the condition of ossicular chain in the middle ear. Preoperative CT findings of the ossicular chain were compared with the operative findings of ossicles in 26 patients with chronic otitis media or congenital ossicular anomaly who underwent tympanoplasty. Total defect of head of the malleus, body of the incus and long process of the incus were completely detected by high-resolution CT. But the reliability in detecting the defect of handle of the malleus and superstructure of the stapes were 33.3% and 60%, respectively. Defect of the I-S joint (1 case) and partial defect of stapes crus (2 cases) could not be diagnosed correctly in the preoperative estimation. Although these findings demonstrate the limitations of high-resolution CT in the diagnosis of ossicular chain, it will be diminished by the advanced space resolution of CT in the future.

Ear Diseases↗
PubMed1992

[Effect of combined therapy with selective beta 1- and alpha 1-adrenergic agonists upon postprandial hypotension in patients with progressive autonomic failure].

Food ingestion increases mesenteric blood flow, and then results in a decrease of total vascular resistance (VR). Postprandial hypotension (PPH) may be caused by a lack of compensatory increase in cardiac output (CO) together with a lack of reflex peripheral vasoconstriction to the decrease in total VR. In order to increase CO and VR, we orally administered both denopamine 10 mg (a selective beta 1-adrenergic agonist) and midodrine HCl 4 mg (a selective alpha 1-adrenergic agonist) to six patients with progressive autonomic failure (AF). PPH was well prevented by concomitant administration of both denopamine and midodrine HCl 30 min before oral ingestion of 75 g of glucose, i.e., CO and portal blood flow as well as VR in the lower legs increased. These hemodynamic reactions after oral ingestion of 75 g of glucose were very similar to those in the control subjects. The marked increase in heart rate after drug administration may be the result of cardiac supersensitivity in patients with AF. Combined oral administration of both denopamine and midodrine HCl is a safe and useful management of PPH in patients with AF.

Administration, Oral↗
PubMed1992

[Usefulness of selective endoscopic retrograde pancreatography (selective ERP) and endoscopic pancreatic biopsy (EPB) in the diagnosis of mucin-producing tumor of the pancreas].

Selective ERP and EPB were employed in the diagnosis of mucin-producing tumor (MPT) of the pancreas and their usefulness was evaluated. Thirty five cases of MPTs were subdivided into three subtypes, i.e., 1) main duct type, 2) branch duct type and 3) peripheral type (mucinous cystadenoma/cystadenocarcinoma). Selective ERP was proved to be useful in demonstrating precise and whole pancreatograms, especially in revealing multiple lesions, when compared with standard ERP. Selective ERP could demonstrate communication between cystic tumors of the peripheral type and the pancreatic duct in seven (88%) of eight cases of the peripheral type, which suggests high frequency of the communication in the peripheral type. For preoperative tissue diagnosis, EPB was shown to be a useful method to yield sufficient tissue materials for histopathological evaluation and may be used as an adjunction method to diagnose the intraductal extent of the tumorous lesion.

Adenocarcinoma, Mucinous↗