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Biomedical subjects

N Kikuchi

Publications and source records attributed to N Kikuchi.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Electrophysiological evaluation of polyneuropathy in juvenile insulin dependent diabetics].

Thirty patients with juvenile insulin dependent diabetes mellitus (IDDM) were electrophysiologically evaluated. In addition to the conventional motor and sensory nerve conduction studies, intrafascicular microneurography was performed in the median nerve. In this method a tungsten microelectrode was inserted into the median nerve trunk at the elbow, and a compound nerve action potential (CNAP) was recorded with supramaximal electrical stimulation at the wrist. The subjects' age ranged from 8 to 31 years with an average (SD) of 15.4 (6.2) years; the disease duration varied from 1 to 23 years with an average (SD) of 8.3 (5.8) years. Polyneuropathy index (PNI), expressed as a mean percentage of the normal for twelve indices over the four nerves obtained by motor conduction studies, was 93.9% on the average in patients with IDDM. The mean amplitude of CNAP obtained by intrafascicular microneurography was 417 microV. These results indicate that neuropathy in IDDM is milder than that in adult non-insulin dependent diabetes mellitus (NIDDM). The mean value of PNI decreased at a rate of 0.56% per year; the mean glycosylated hemoglobin (A1c) level was as high as 8.2 +/- 0.9%, findings consistent with those of the previous analysis of adult patients with NIDDM. The PNI value had a significant negative correlation with the duration of diabetes mellitus (p < 0.001) and with mean glycosylated hemoglobin (A1c) level (p < 0.01). CNAP amplitude had a tendency to correlate with duration of diabetes mellitus (p < 0.1). In patients with IDDM we can tell exactly when the disease occurred. Progression of neuropathy in juvenile IDDM was identical to that of adult NIDDM. Careful management of diabetes mellitus is of importance to prevent the progression of neuropathy.

Action Potentials↗
PubMed1996

Prolonged survival of rat hepatic allografts pretreated with a single donor-specific blood transfusion: the distribution of donor cells expressing class I major histocompatibility complex antigens in the recipient.

We previously reported that a pretransplant transfusion of either ACI strain rat donor blood or PVG.r1 strain blood, which shares only the RT1.A class I major histocompatibility complex (MHC) region with an ACI donor, significantly prolonged the survival of ACI-to-LEW rat hepatic allografts, suggesting that the class I MHC antigens can be immunosuppressive in rat hepatic allografts. The distribution of the donor cells expressing RT1.Aa class I MHC antigens in the recipients was investigated using a MN4-91-6 mouse anti-rat class I (RT1.Aa) MHC monoclonal antibody. The donor class I MHC-positive cells accumulated mainly in the splenic white pulp and lymph nodes at 12 and 24 hr after blood transfusion, while very few cells were seen in the thymus, liver, lungs, and kidneys. The number of cells began to decrease in the splenic white pulp and lymph nodes at 24 hr after transfusion. This may indicate the destruction of donor cells by the recipient cells. Within 48 hr after transfusion, most cells disappeared from the recipient tissue. In an attempt to study the role of the spleen in inducing immunological unresponsiveness, a splenectomy was performed at the time of transplantation and this abrogated the prolongation of hepatic allograft survival in the recipients which received the donor blood. These findings suggest that the presence of class I MHC-positive cells in the splenic white pulp, a T-dependent area, may play an important role in inducing immunological unresponsiveness.

Animals↗
PubMed1996

Suppression of hepatic allograft rejection in the rat by mitomycin C-treated donor splenocytes: in situ splenic distribution of donor class I major histocompatibility complex antigen-positive cells in the recipient.

A single intravenous injection of 3 x 10(6) donor splenocytes treated with mitomycin C (MMC) 7 days before hepatic transplantation prolongs survival of hepatic allografts in the ACI(RT1a) to LEW(RT1(1)) rat combination. This effect is donor specific. The in situ distribution in the recipient of the donor cells administered preoperatively was investigated using intracellularly fluorescence-labeled donor splenocytes. The donor cells were accumulated mainly in the splenic white pulp and lymph nodes at 12 and 24 hr after injection. Contrarily, very few cells were seen in the thymus, liver, kidney, and lung. The number of cells with dull and weak fluorescence began to increase in the splenic white pulp and lymph nodes at 24 hr after injection. This may indicate the breakdown of donor cells by recipient cells. In contrast, a number of donor cells could be detected even after 48 hr and a few cells at 7 days after splenocyte injection in the LEW-to-LEW isogeneic combination. As we previously revealed the role of class I major histocompatibility complex (MHC) antigens in prolonging hepatic allograft survival in the rat, the splenic distribution of donor class I MHC-positive cells in the recipient after intravenous administration of MMC-treated donor splenocytes was studied using immunostaining with a MN4-91-6 mouse anti-rat RT1.Aa class I MHC monoclonal antibody. The donor class I-positive cells accumulated mainly in the splenic white pulp at 12 and 24 hr after injection. This is similar to that observed in the fluorescence study. Within 48 hr after injection, most cells had disappeared from the recipient tissue. These findings suggest that the splenic white pulp, a T-dependent area, may play an important role in inducing immunological unresponsiveness.

Animals↗
PubMed1996

Papillary fibroelastoma of the tricuspid valve in association with an atrial septal defect: report of a case.

Although papillary fibroelastoma is rare, it is the most common primary tumor of the heart valves. We describe herein the case of a 64-year-old woman scheduled to undergo atrial septal defect (ASD) repair, in whom a papillary fibroelastoma of the tricuspid valve was diagnosed by transesophageal echocardiography (TEE). Surgical resection of the papillary fibroelastoma at the time of ASD repair prevented the fatal embolization sometimes associated with this lesion. Thus, intraoperative TEE played an important role in identifying the location of the tumor and its anatomic attachment, and in assessing the adequacy of surgical treatment.

Echocardiography, Transesophageal↗
PubMed1996

Technique for orthotopic reduced-size hepatic transplantation combined with ex vivo liver cut down in the rat.

A technique is described for orthotopic reduced-size hepatic transplantation combined with ex vivo liver cut down in the rat. Following perfusion of the donor liver with cold heparinized saline, the portal veins, bile ducts, and hepatic arteries to the median and left lobes together were dissected in situ, encircled, and divided. After harvesting the donor liver, a hepatectomy was performed by ex vivo liver cut down of the median and left lobes. The remnant amounted to 32% of the whole liver. As a result, the suprahepatic vena cava could be well visualized with adequate exposure for vascular anastomosis. Orthotopic reduced-size hepatic transplantation was performed using the right and caudate lobes of the liver. The suprahepatic vena cava was anastomosed with a 7-0 silk running suture. A simplified cuff without processes was made with an obliquely cut polyethylene tube and used for the portal and infrahepatic caval anastomoses. A Teflon tube stent was used for the biliary anastomosis. The newly devised angled clamp and flexible arm were used for the cuff attachment and operative procedure. Transplant survival following ex vivo liver cut down was as good as that with whole liver transplantation. Reestablishment of the hepatic artery restores liver function following transplantation. The maximum hepatocyte labeling index (LI) occurs 24 hr after a 68% hepatectomy, and at 36 hr following a reduced-size hepatic transplantation with or without hepatic arterialization. Possible explanations for the slight delay in achieving the maximal LI may include damage that is induced by the operation itself, pregraft preservation, and reperfusion injuries. In conclusion, the anatomical features of the hepatic lobes in rats are well suited to successful completion of ex vivo liver cut down.

Animals↗
PubMed1996

A mutant trypsin-like enzyme from Streptomyces fradiae, created by site-directed mutagenesis, improves affinity chromatography for protein trypsin inhibitors.

The Ser-170 residue of a trypsin-like enzyme from Streptomyces fradiae (SFT), which is considered to be the active-site serine, was replaced with alanine by site-directed mutagenesis to improve the affinity chromatography step for a Kazal-type trypsin inhibitor pancreatic secretory trypsin inhibitor (PSTI). The resulting mutant SFT, designated as [S170A]SFT, was expressed in Streptomyces lividans and purified to homogeneity. [S170A]SFT was catalytically inactive, but still had the ability to bind tightly to PSTI and to soybean trypsin inhibitor with dissociation constants of 3.1 x 10(-7) M and 1.9 x 10(-8) M respectively. We further demonstrated that recombinant human PSTI secreted into Saccharomyces cerevisiae culture broth could be purified to homogeneity with a one-step [S170A]SFT-affinity column. The purified PSTI contained no molecules intramolecularly cleaved by active trypsin, which are found when trypsin-affinity chromatography is used for the purification. This eliminated the need for further separation of intact PSTI from intramolecularly cleaved PSTI by high-performance liquid chromatography, thus simplifying and improving its purification process.

Chromatography, Affinity↗
PubMed1996

Distribution of Corynebacterium renale among apparently healthy rats.

We examined the distribution of Corynebacterium renale, a causative agent of urinary calculus, in clinically normal rats at 6 animal facilities in Japan. Swabs of the vulva and vaginal vestibule or prepuce of the rats were cultured for isolation of the organisms. C. renale has been isolated at only one animal facility, where cases of urinary calculus were reported several years ago. In this facility, 32% of female (43/135) and 22% of male (18/82) rats, 4-28 weeks old, were positive for C. renale. In contrast, 92 female and 169 male rats at other facilities without a history of the disease were negative for the organisms.

Animals↗
PubMed1996

Absorbable and nonabsorbable buried sutures for primary cleft lip repair.

Absorbable and nonabsorbable buried sutures were studied in primary cleft lip repair. Group 1 (N = 56) consisted of patients repaired with buried nonabsorbable material (monofilament nylon). Group 2 (N = 47) consisted of patients repaired with absorbable materials (polyglyconate, polydioxanone). All patients were monitored for 12 months. There were stitch abscesses in Group 1 (14%). There were no abscesses in Group 2. This difference was significant (p = 0.007). Abscesses were located in the suture line with no identifiable distribution. There was no significant difference in the cosmetic appearance of the scars in Groups 1 and 2. These results support the view that absorbable sutures are preferable to nonabsorbable sutures for primary cleft lip repair.

Abscess↗
PubMed1996

Free temporal fascial flap for coverage and extensor tendon reconstruction.

An improved method for reconstructing injured tendons of the dorsum of the hand is presented. We transferred a two-layered temporal fascial flap to the hand and inserted the rolled, deep temporal fascia between the stump of the extensor tendons. This procedure can improve extensor tendon function with minimal scarring in spite of the limitation of available tissue.

Adult↗
PubMed1996

A novel proteinaceous Kex 2 proteinase inhibitor, kexstatin, from Streptomyces platensis Q268.

We found a novel proteinaceous Kex 2 proteinase inhibitor, named kexstatin, in the culture supernatant of Streptomyces platensis Q268. The purified kexstatin was homogeneous by SDS-PAGE and the molecular weight was estimated to be 13,000. The N-terminal amino acid sequence of kexstatin has high similarity to Streptomyces subtilisin inhibitor (SSI), suggesting that kexstatin belongs to the SSI family. Kexstatin was a strong inhibitor of Kex 2 proteinase and subtilisin but not thermolysin, trypsin, or chymotrypsin. The IC50 value of kexstatin against 1 microgram of Kex 2 proteinase was 1.4 micrograms.

Amino Acid Sequence↗
PubMed1996

Biochemical changes in fowl serum during infection with Salmonella typhimurium.

Two groups of White Leghorns were inoculated with Salmonella Typhimurium in the breast muscle. One group was injected with amikacin every 9 hr (8 times) from 24 to 96 hr after the bacterial inoculation and the other group was given no amikacin. In both groups, a significant increase in the levels of aspartate aminotransferase and creatine kinase, and a significant decrease in the levels of alkaline phosphatase, total cholesterol and glucose were found 96 hr after inoculation. There were, however, no significant differences in the blood chemical values between the amikacin-treated group and non-treated group. The results from the present study may provide basic data for further investigation of blood chemical values during Salmonella infection and amikacin therapy in fowls.

Alkaline Phosphatase↗
PubMed1996

Comparative preparation methods of sialylated capsule antigen from Streptococcus suis type 2 with type specific antigenicity.

The capsular polysaccharide (CPS) of Streptococcus (S.) suis type 2 was isolated from a type strain of S. suis NCTC 10234 by three different preparative methods: (A) lysozyme treatment method, (B) autoclave extraction method, and (C) HCl-extraction method. The structural characteristics of the three CPS (CPS-A, B and C) were examined by gel permeation chromatography, reactivity against rabbit antiserum and proton-nuclear magnetic resonance (1H-NMR). N-Acetylneuraminic acid (NeuAc) residues as sialic acid in CPS-C were partially dissociated or degraded during preparation with a remarkable decrease in the molecular mass and the antigen activity. Although both methods A and B produced intact CPS without releasing NeuAc residues, method B was considered to be a more suitable procedure for preparing the CPS antigen because of time-saving and safety factors. Sugar analysis by high performance liquid chromatography and gas liquid chromatography showed that CPS-B consisted of five kinds of sugars: Rhamnose (Rha), Glucose (Glc). Galactose (Gal), N-acetylglucosamine (GlcNAc) and NeuAc, in a molar ratio of 1.00:0.95:3.68:0.80:1.31. After complete removal of NeuAc residues by mild acid hydrolysis of CPS-B, the reactivity with anti-type 2 serum was not detected. The NeuAc residue in CPS of S. suis type 2 strain was thought to be the antigen epitope portion.

Antigens, Bacterial↗
PubMed1996

Antimicrobial effects of amikacin therapy on experimentally induced Salmonella typhimurium infection in fowls.

The antimicrobial effects of amikacin on Salmonella Typhimurium were investigated in fowls using pharmacokinetic parameters of amikacin and the minimum inhibitory concentration (MIC) of the drug for the bacteria. Pharmacokinetic parameters of amikacin after the intramuscular administration into the fowls were measured using the fluorescence polarization immunoassay. As there was no protein binding amikacin, the total concentration was identical to the free concentration. After inoculation of the bacteria, the following intramuscular dosage regimens were carried out to test the antimicrobial effects: injection with 20 mg/kg of amikacin sulfate every 9 hr for 72 hr, injection with 20 mg/kg every 18 hr for 72 hr, injection with 20 mg/kg every 36 hr for 72 hr, and injection with 10 mg/kg every 12 hr for 72 hr. The control birds were not injected with amikacin. Abdominal organs were collected from each bird after the treatment ended. The organs were cultured and the number of colonies on each plate was calculated. No significant differences were detected among the four amikacin-treated groups, whereas the number of colonies in the control group was significantly higher than that in the amikacin-treated groups. An antimicrobial drug concentration exceeding the bacterium's MIC for at least 1/4 of the administration interval might be effective for the treatment of the infection, and the degree of peak drug concentration had no effect on antibacterial activity as long as the duration of the drug concentration above the MIC value remained the same.

Amikacin↗
PubMed1996

Detection of leptospiral plasmid and comparison of plasmid profiles between virulent and avirulent leptospires.

Detection of plasmid from leptospires and a comparison of the plasmid profiles between virulent and avirulent strains were performed to investigate whether leptospires contained plasmid(s) associated with virulence. Virulent strains of Leptospira interrogans serovars copenhageni, lai, canicola and pomona, which were virulent for the guinea pig and/or hamster and which showed chemotaxis toward hemoglobin, contained approximately 370 kilobases (kb) plasmid. Avirulent strains of L. interrogans also contained identical plasmid. Similar plasmid profiles in virulent and avirulent strains of L. interrogans were observed. These data showed that no plasmids associated with virulence or chemotaxis were detected. Strains of saprophytic leptospires, L. biflexa and Leptonema illini, did not possess any plasmid.

Animals↗
PubMed1996

Effect of estrogen replacement therapy on hepatic triglyceride lipase, lipoprotein lipase and lipids including apolipoprotein E in climacteric and elderly women.

Estrogen provides beneficial effects on hyperlipidemia in climacteric and elderly women. In this study of 68 women (37 to 67 years old), hepatic triglyceride lipase (HTGL), lipoprotein lipase (LpL) serum lipids and apolipoproteins were analyzed to investigate the effects of estrogen replacement therapy (ERT). After menopause, LpL, total cholesterol, low-density lipoprotein (LDL)-cholesterol, and apolipoprotein B increased. But ERT suppressed total cholesterol, LDL-cholesterol, apolipoprotein B, and especially apolipoprotein E in menopausal women. The mechanism was thought that ERT significantly suppressed HTGL, but LpL was not affected. Estrogen also increases hepatic LDL receptors and accelerates transfer of serum LDL-C (and TC). It was said that HTGL accelerates conversion of intermediate-density lipoprotein (IDL) to LDL. The suppression of HTGL by the ERT may decrease conversion of IDL to LDL and lower LDL-C (and TC). These estrogen's beneficial effects on lipids, may prevent the atherosclerosis. In addition, apolipoprotein E increases senile plaques in senile dementia-Alzheimer's type. The decrease in apolipoprotein E with ERT may be related to cognitive functions of elderly women.

Adult↗
PubMed1996

Prevalence of hypertension and rate of blood pressure control as assessed by home blood pressure measurements in a rural Japanese community, Ohasama.

A cross-sectional community survey using home blood pressure measurements was performed in northern Japan to estimate the prevalence of definite hypertension, white coat hypertension and the success of blood pressure control in patients receiving antihypertensive drugs. A total of 1334 subjects (mean age +/- SD, 53.8 +/- 17.3 years; 8-91 years) participated in the screening and home blood pressure measurement program. They measured blood pressure at home at least 3 times (mean measurement frequency, 20.8 +/- 8.3 times). Of these 1334 subjects, 314 (65.1 +/- 8.9 years) were taking drugs (treated group) while 1020 (50.3 +/- 17.8 years) were not (untreated group). The WHO criteria were used to categorize screening blood pressure. Criteria for diagnosis of hypertension by home blood pressure measurements were as follows: definitely hypertensive (systolic blood pressure > or = 144 mmHg and/or diastolic blood pressure > or = 89 mmHg) and normotensive (104 < systolic blood pressure < or = 131 mmHg and 60 < diastolic blood pressure < or = 79 mmHg). Of the 1018 subjects identified as normotensive on screening measurements, home measurements indicated that 73 (7.2%) were hypertensive and 765 (74.7%) were normotensive or lower. Of the 112 subjects identified as hypertensive on screening measurements, home measurements showed that 42 (37.5%) were hypertensive and 30 (26.8%) were normotensive or lower. Of the 314 treated subjects, 45 (14.3%) were identified as hypertensive by screening measurements and 88 (28.0%) as hypertensive by home measurements. Only 20 (44.4%) of the former 45 subjects were also defined as definitely hypertensive by home measurements. Of the 1020 untreated subjects, 67 (6.6%) were hypertensive by screening measurements and 84 (8.2%) by home measurements. Only 22 (32.8%) of the former 67 subjects were classified as hypertensive by home measurements. Of the 67 untreated subjects identified as hypertensive by screening measurements, 20 (29.9%) were normotensive or lower by home measurements, suggesting that these subjects were "white coat" hypertensives. The study first confirmed based on the large community data that there are large discrepancies between screening (casual) blood pressure and home blood pressure measurements for recognition of hypertension and normotension. Determination of blood pressure levels by home blood pressure measurements may predict prognosis of hypertension differently from that by screening blood pressure measurements. Further prospectively study is needed to validate the prognostic value of home blood pressure measurements.

Adolescent↗