Biomedical subjects

K Ishihara

Publications and source records attributed to K Ishihara.

At least 433 records · Page 24Linked to original sources

PubMed1993

[Chemotherapy of malignant melanoma].

Malignant melanoma is among the malignant tumors which still have the poorest prognosis. Thus, malignant melanoma of stage II and the more advanced stages. At present, chemotherapeutic combinations used as the first choice in Japan are two regimens of postoperative adjuvant therapy for stage II and III patients, that aim at preventing recurrence. One of the regimens is a DAV combination (Dacarbazine, ACNU, vincristine), and another is PAV combination (Pepleomycin, ACNU, vincristine). For stage IV patients, the major therapeutic procedure is a CDV combination (cisplatin, dacarbazine, vindesine). The efficacy of CDV treatment has been approximately 30 per cent in our studies. It has shown comparable effects for metastatic lesion in the lymph nodes, mucous membrane (nasal cavity) and brain, while lesions in other organs are largely unaffected in many instances. Studies of new drugs and combinations must be undertaken for the treatment of malignant melanoma.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1993

[Pre and postoperative left ventricular volume and function in infants and children with total anomalous pulmonary venous return].

From January, 1989, to December, 1991, 36 consecutive patients with total anomalous pulmonary venous return (TAPVR) underwent intracardiac repair (ICR) in our institute. We studied the relationship between the size of atrial septal defect (ASD), age and preoperative left ventricular end-diastolic diameter (LVEDD) in 28 patients with regression analysis. There was no statistical relationship between the size of ASD, age and LVEDD. We measured LVEDD, RV to LV pressure ratio (RVP/LVP) and LV fractional shortening (LVFS) using two dimensional echocardiography in 15 patients, prior to and following ICR. LVEDD increased from 1.16 +/- 0.40 cm to 1.62 +/- 0.28 cm immediately following ICR, and then increased to 1.79 +/- 0.34 cm one month following ICR again. LVFS decreased from 38% to 35% immediately following ICR but still remained within normal range (normal range 28-45%). RVP/LVP decreased from 1.0 to 0.69 immediately following ICR, and to 0.39 one month following ICR. We concluded that the decrease of preoperative LV end-diastolic volume in TAPVR was not due to the decrease of LV preload but to anterior deviation of the ventricular septum caused by high RV pressure. There was significant increase of LV volume immediately following ICR, but LVFS maintained in normal range. This study suggested that small LV volume in patients with TAPVR did not influence the surgical results.

Echocardiography↗

PubMed1993

[Ultrasonographic study of low-lying placenta and its clinical significance].

Low-lying placenta is reported to cause PROM, preterm labor, and abnormal bleeding during pregnancy and labor, but it has not been clearly defined how low the placenta has to be implanted to categorize it as "low-lying". In the present investigation, using ultrasonography, the distance between the placental implantation site and the internal cervical os in relation to gestational outcome was investigated to clarify the diagnosis and clinical significance of low-lying placenta. 1. Placental implantation site in normal gestation 1) In none of the cases at week 28 of gestation or later, the distance was 2cm or less between the lower edge of the placenta and the internal cervical os. At week 32 or later, the distance was 3cm or less in none. 2) At week 36 or later, it was 5 cm or more in all cases. 2. Low-lying placenta in association with gestational or labor outcome When "low-lying placenta" was tentatively defined as the placenta implanted within 2cm from the internal os and "normal placenta" as one implanted 2.1 cm or more from the internal os, the following findings were obtained. 1) The incidence of low-lying placenta was 2.8% (49/1,771) at gestational weeks 20 < or = - < 24, 0.96% (17/1,771) up to gestational week 29, and 0.73% (13/1,771) up to 1 week prior to labor. 2) The incidence of bleeding during gestation, preterm labor, PROM and emergency C/S was higher in the 13 cases with low-lying placenta remaining until labor than in 1,749 cases (p < 0.05) normally sited.(ABSTRACT TRUNCATED AT 250 WORDS)

Cesarean Section↗

PubMed1993

[Progressive course of nephropathy with non-insulin-dependent diabetes mellitus--structural-functional relationship].

We studied quantitatively a morphological change in diabetic nephropathy by light microscopy. The renal biopsy specimens were examined using color image processor in 53 patients with non-insulin-dependent diabetes mellitus (NIDDM). These patients, aged 22 to 69 years, had been NIDDM for 2 months to 27 years. Glomerular area (GA), mesangial rate (MR) and length of capillary filtration (CFL) were used as the morphological parameters. Duration of diabetes, urinary albumin excretion and creatinine clearance (Ccr) were chosen as clinical manifestations. Duration of diabetes was correlated with MR (r = 0.55, p < 0.01), but not GA. Glomerular hypertrophy could not be found. A significant relationship between Ccr and CFL were noticed (r = 0.64, p < 0.01).

Adult↗

PubMed1993

[Measurement of cardiac output by Doppler echocardiography: clinical validation in pediatric patients after open heart surgery].

We compared the cardiac output obtained by pulsed Doppler echocardiography (COPW) with simultaneous thermodilution measurements (COTD) in 13 children for 33 times after open heart surgery. Good correlation (r = 0.84, slope = 1.15) of cardiac output was obtained when direct measurements of aortic diameter during operation were used in the calculations. Cardiac output was overestimated (r = 0.89, slope = 1.42) when 2 DE measurements of aortic diameter were used. Nineteen measurements of 8 VSD patients revealed good correlation (r = 0.89, slope 0.85) using direct measurement of aortic diameter, whereas 14 measurements of TOF patients showed somewhat overestimation of cardiac output (r = 0.90, slope = 1.31). In serial determinations, percent change change in COPW well correlated with COTD (r = 0.75, slope = 1.08). We conclude that accurate cardiac output can be obtained by pulsed Doppler echocardiography after pediatric cardiac surgery by measuring aortic diameter directly in operation room. Accuracy in percent change in cardiac output proved that COPW is useful especially in hemodynamically unstable patients after pediatric cardiac surgery.

Age Factors↗

PubMed1993

[A case report of pulmonary valve blood cyst].

A six-year-old boy with pulmonary stenosis was hospitalized in order to examine the cause of pulmonary stenosis. The right-ventriculography showed a large shadow defect in the right ventricular outflow tract. But the echocardiography showed the cystic tumor, which was covered with thin wall and had echo-free space in it, in the right ventricular outflow tract. We made a diagnosis of pulmonary blood cyst. After cardiopulmonary bypass was established, the main pulmonary artery was incised longitudinally. There were two blood cysts at the left pulmonary cusp which were 1.5 x 1.5 cm and 0.7 x 0.5 cm in size. The cysts were resected and the pulmonary cusp was plicated. Histologically, the wall of the cysts was consisted thick valvular tissues. No pulmonary valve pressure gradient was detected with the echocardiography following the operation.

Child↗

PubMed1993

[Surgical treatment of double orifice mitral valve in atrioventricular septal defect].

Ten patients with double orifice mitral valve and atrioventricular septal defect (AVSD) were examined. There were four cases with incomplete type, three with intermediate type and three with complete type AVSD. All patients with incomplete type AVSD were doing well after the mitral cleft repair, Leaving the accessory orifice untouched. Various valve repair procedures and prosthetic valve replacement were performed in the patients with intermediate and complete types of AVSD with left-sided atrioventricular valve regurgitation. There were three operative deaths, which included one patient with the intermediate type and two with the complete type. All of them were one-month old babies and were operated on emergency. Their general operative findings were hypoplasia of the common atrioventricular valve leaflets, abnormal attachment of the chorda tendineae and papillary muscle dysplasia. These findings increased the difficulty of the valve plasty to control mitral regurgitation.

Child↗

PubMed1993

Anatomic correction of atrioventricular discordance.

Between June 1989 and September 1991, 11 patients underwent anatomic correction of atrioventricular discordance. Their ages at operation ranged from 1 to 11 years (mean 6.7 years) and their weights ranged from 7.1 to 31.8 kg (mean 19.1 kg). Atrial situs was solitus in nine and inversus in two patients. Ventriculoarterial connection was discordant in five and was double-outlet right ventricle in six patients. Associated congenital heart defects were seen in all patients, including 10 with ventricular septal defect, eight with atrial septal defect, nine with pulmonary stenosis or pulmonary atresia, seven with tricuspid regurgitation, and four with mitral regurgitation. Five patients had prior Blalock-Taussig shunts. One patient with an intact ventricular septum had repeated pulmonary banding. Anatomic correction consisted of the Senning and Rastelli procedures in three, the Mustard and Rastelli procedures in five, the Senning and arterial switch operations in two, and the Mustard and arterial switch operations in one patient. In addition, mitral valvuloplasty or valvular annuloplasty was performed in three patients. We did not encounter kinking or torsion of the translocated coronary arteries in our three patients with the arterial switch operation. There was one surgical death. The other patients pursued satisfactory postoperative courses (mean follow-up period of 12.6 months). We recommend that anatomic correction for atrioventricular discordance should be indicated, especially in patients with any sign of systemic right ventricular dysfunction.

Cardiac Surgical Procedures↗

PubMed1992

Antiepileptic effects of CNK-602A, a novel thyrotropin-releasing hormone analog, on absence-like and tonic seizures of spontaneously epileptic rats.

The effects of CNK-602A (N-[(6-methyl-5-oxo-3-thiomorpholinyl) carbonyl]-L-histidyl-L-prolinamide), a novel thyrotropin-releasing hormone related analog, were investigated on absence-like seizure and tonic convulsion in the spontaneously epileptic rat (SER), which is a genetically defined double-mutant. When CNK-602A of 0.2-1 mg/kg was given intravenously to the animal, there were no changes in the background EEG except for an increase in low-voltage fast waves concomitant with behavioral alertness. However, CNK-602A suppressed absence-like seizure and tonic convulsion in a dose-dependent manner for over 1 h. These antiepileptic effects of CNK-602A on both seizures were antagonized by pretreatment with haloperidol (1 mg/kg, i.p.). It was found, using a brain in vivo microdialysis method, that CNK-602A at a dose of 1 mg/kg, which inhibits the seizures, increased the release of dopamine in the caudate nucleus. These results suggest that CNK-602A inhibits the seizures of SER in a similar manner to thyrotropin-releasing hormone (TRH), probably by increasing the release of dopamine in the central nervous system. In addition, the antiepileptic effects of CNK-602A were more potent and lasted longer than those of TRH.

Animals↗

PubMed1992

Molecular cloning in Escherichia coli, expression, and nucleotide sequence of the gene for the ethylene-forming enzyme of Pseudomonas syringae pv. phaseolicola PK2.

The gene for the ethylene-forming enzyme of Pseudomonas syringae pv. phaseolicola PK2 was found to be encoded by an indigenous plasmid, designated pPSP1. The gene for the ethylene-forming enzyme was cloned and expressed in Escherichia coli JM109. Nucleotide sequence analysis of the clone revealed an open reading frame that encodes 350 amino acids (mol. wt. 39,444). In a comparison with other proteins, the homology score for the entire amino-acid sequence of the ethylene-forming enzyme of Pseudomonas syringae versus ethylene-forming enzymes from plants and 2-oxoglutarate-dependent dioxygenases was low. However, functionally significant regions are conserved.

Amino Acid Sequence↗

PubMed1992

[A clinical trial of whole liver simultaneous dynamic MR imaging and its usefulness].

A clinical trial of whole liver simultaneous dynamic MRI was done. In 23 second whole liver was able to be scanned using parameters of filed echo method as follows: TR = 315 msec, TE = 7 msec, Flip angle = 70 degrees or 90 degrees, MAT = 50%, ECD = 60%, FOV 40 cm and no presaturation. Even 2-3 mm nodules of metastatic tumors and small daughter nodules of hepatocellular carcinoma such as 5 mm were demonstrated in the arterial phase clearly.

Adult↗

PubMed1992

B29 gene products complex with immunoglobulins on B lymphocytes.

B29 is a B-lineage-specific gene predicted from sequence information to be a transmembrane member of the immunoglobulin (Ig) superfamily, with a single extracellular Ig-like domain. Its presumptive cytoplasmic region contains a peptide motif present in CD3 and other molecules involved in lymphocyte activation. Affinity-purified goat antibodies were prepared to a TrpE fusion protein of B29 and used to study B29 expression on lymphoid cells. The antiserum precipitated surface-labeled heterodimers from B lymphoma cells. One was 65-88 kDa (unreduced) or 36-47 plus 32-34 kDa (reduced) by SDS/PAGE analysis, regardless of detergent. A smaller heterodimer was detected only with Triton detergent extraction. IgM molecules were coprecipitated by the B29 antiserum when the weak detergent digitonin was used. In addition, cocapping experiments revealed that most B29 molecules codistribute with Ig on the cell surface. Although early B-lineage cells and plasma cells contain B29 mRNA, surface expression was detectable only on B cells that had significant amounts of surface Ig. The surface expression was B-lineage-specific and included cells from mutant xid mice and B-cell lines representing mu, delta, gamma, and alpha heavy-chain isotypes and both kappa and lambda light-chain types. The density of surface B29 protein correlated directly with surface mu heavy-chain density on subclones of a B-cell lymphoma and lipopolysaccharide-stimulated pre-B cells. These findings show that B29 is covalently linked in a heterodimer and are consistent with a recently proposed model of surface Ig complexes.

Animals↗

PubMed1992

Adhesive bone cement containing hydroxyapatite particle as bone compatible filler.

Acrylic bone cement containing hydroxyapatite (HA) as a filler was developed using 4-methacryloyloxyethyl trimellitate anhydride (4-META) to promote adhesion both to bone and HA. The mechanical strengths of the cement did not decrease significantly with increasing HA in the cement by 4-META. However, strengths decreased with increasing HA content in the absence of 4-META. Scanning electron micrographic examination of fractured surfaces of the cement clearly showed that the HA particles adhered to the matrix resin when 4-META was added. Thus, it was important to maintain the original mechanical strengths for 4-META. The HA particles along the surface increased with increased HA content in the cement. The cement adhered to bone with a tensile bond strength was higher than 10 MPa.

Acrylic Resins↗

PubMed1992

Hemocompatibility of human whole blood on polymers with a phospholipid polar group and its mechanism.

The hemocompatibility of a polymer containing a phospholipid polar group, poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate(BMA)), with human whole blood was evaluated. When human whole blood without an anticoagulant was contacted with polymers, the blood cell adhesion and aggregation on the polymer without the MPC moiety was extensive, and considerable fibrin deposition was observed. This phenomenon was suppressed with an increase in the polymer MPC composition. Thus, the MPC moiety in the copolymer plays an important role in the nonthrombogenic behavior of the copolymer. These results were also confirmed by the whole blood coagulation time on the polymer surface which was determined by Lee-White method. The adsorption of phospholipids and proteins from human plasma on poly(MPC-co-BMA) was investigated to clarify the mechanism of the nonthrombogenicity observed with the polymer. The amount of phospholipids was increased; whereas, adsorbed proteins were decreased with an increase in the MPC composition. From these results, we concluded that the phospholipids adsorbed on poly(MPC-co-BMA) play the most important role in the nonthrombogenicity of the MPC copolymer.

Adsorption↗

PubMed1992

Proliferative activity of cutaneous melanocytic neoplasms defined by a proliferating cell nuclear antigen labelling index.

To evaluate the proliferative activity of benign, borderline and malignant cutaneous melanocytic neoplasms, 30 cases of malignant melanoma (MM) and 41 cases of naevi were studied by immunostaining using a monoclonal antibody against proliferating cell nuclear antigen (PCNA). PCNA is a nuclear antigen expressed in the late G1 and S phase and serves as a marker of proliferating cells. Invasive MM and MM in situ showed much higher PCNA positivity rates than melanocytic naevi (invasive MM, 18.0%; MM in situ, 11.3%; ordinary melanocytic naevi, 2.6%). The PCNA positivity rate did not increase significantly with the thickness of MM. Among ordinary melanocytic naevi, junctional naevi had a higher PCNA positivity rate than compound or intradermal naevi. Mean PCNA positivity rates for Spitz's naevi and sporadic dysplastic naevi were within the range for ordinary melanocytic naevi, indicating the benign nature of both types of naevus. Contrary to some previous studies, MM in situ showed high proliferative activity, indicating that cells of MM in situ are actively proliferating. This study clearly demonstrates that MM and various types of naevi can be separated according to differences in proliferative activity defined by the PCNA labeling index.

Antibodies, Monoclonal↗

PubMed1992

Effects of tetragastrin on mucus glycoprotein in rat gastric mucosal protection.

The effects of tetragastrin on mucus glycoprotein (mucin) metabolism and mucosal protection in rat gastric mucosa were investigated. Rats were administered with various doses of tetragastrin (12, 120, or 400 micrograms/kg body weight; s.c.), followed by 50% ethanol-induced gastric injury. Tetragastrin caused a significant increase in mucin content in the corpus mucosa and prevented 50% ethanol-induced gastric mucosal damage in a dose-dependent manner. For assessment of the effects of tetragastrin on the metabolism of gastric mucin in detail, changes in mucin distribution in the three different layers of rat gastric mucosa were examined one hour after single administration of tetragastrin. A significant increase in the mucin content was noted in the mucus gel and surface mucosal layer. Mucin content in the deep mucosa corresponding mainly to the mucus neck cell mucin underwent virtually no change by this treatment. An increase in mucin in the mucus gel and surface mucosa would thus appear due to the administration of tetragastrin and may possibly be related to the protective action of the gastric mucosa against injury. The data demonstrate a possibility that gastrin may have potential for enhancing gastric mucosal protection associated with mucus secretion and/or mucus synthesis on the surface mucosa of rat gastric mucosa.

Animals↗

PubMed1992

A separating method for quantifying mucus glycoprotein localized in the different layer of rat gastric mucosa.

A method was devised for separating rat gastric mucosa into three layers each containing a different mucin species. The mucus gel (first layer) was removed by stirring the gastric mucosa in a solution of phosphate-buffered saline containing 2% N-acetylcysteine. The surface mucosa (second layer), rich in surface mucus cells, was then separated from the deep mucosa (third layer) containing mucus neck cells, by scraping with forceps. The effectiveness of this method was confirmed by light microscopical observation after GOCTS-PCS (dual staining by the galactose oxidase-cold thionin Schiff method and paradoxical concanavalin A method) and AB-PAS staining (dual staining with alcian blue and the periodic acid Schiff method). The fixed specimen of scraped mucus and cell debris was rich in AB-PAS and GOCTS positive mucus, but was hardly stained by PCS, indicating mucus derived from surface mucus cells to have been efficiently recovered from this preparation. The residual mucosa could be stained by PCS but hardly at all by AB-PAS or GOCTS. The lyophilized powder specimens obtained from the three different layers of rat gastric mucosa were used to extract and quantify mucus glycoprotein (mucin). This was done to examine changes in mucin content in the three layers of gastric mucosa one hour following the oral administration of 20% ethanol or 0.35 N hydrochloric acid, both mild irritants. Mucin content was noted to significantly increase in the first layer but hardly at all in the second layer. In the third layer, it decreased significantly by 0.35 N hydrochloric acid, but changed only slightly by 20% ethanol administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

A biocompatible needle-type glucose sensor based on platinum-electroplated carbon electrode.

A biocompatible needle-type glucose sensor with a 3-electrode configuration was constructed. A platinum-electroplated carbon stick was used as the working electrode, Ag/AgCl as the reference electrode, and a disposable hypodermic needle made of stainless steel as the counter electrode. A Nafion membrane, an immobilized glucose oxidase (GOD) membrane, and a biocompatible membrane with diffusion-limiting effect were coated successively onto the working electrode. The sensor showed a rapid response (< 120 s in batch operation), good reproducibility (RE < 3%), good stability (over 36 h in control serum), a wide dynamic range (5-600 mg/dL glucose), and superior biocompatibility. It was used to determine glucose in serum. The data obtained from the sensor showed good agreement with that from a clinical autoanalyzer (R > 0.95).

Biocompatible Materials↗