PubMed Health⌕ Search

Biomedical subjects

K Numata

Publications and source records attributed to K Numata.

At least 19 recordsLinked to original sources
PubMed1992

Electrophysiologic findings in optic nerve dysfunction associated with multiple evanescent white-dot syndrome.

Electrophysiologic findings in a case of multiple evanescent white-dot syndrome were studied. A 37-year-old woman presented with multiple white dots, granularity of the macula, and optic disc swelling in her left fundus. The electroretinogram and electro-oculogram revealed abnormal findings indicative of changes in the retinal pigment epithelium and photoreceptors. In addition, relative afferent pupillary defect, enlargement of the blind spot, a decrease in the critical fusion frequency, staining of the optic disc on fluorescein angiography and prolonged latency of the P100 component with decreased amplitude in pattern-reversal visual evoked cortical potential strongly suggested dysfunction of the optic nerve in this patient.

Adult↗
PubMed1992

Serial measurement of urinary VMA and HVA levels from one infant: a study for neuroblastoma mass screening.

Urinary vanillylmandelic acid (VMA), homovanillic acid (HVA), and creatinine in 188 samples from one infant during the ages of 1 to 12 months were measured serially by high-performance liquid chromatography (HPLC). The mean VMA and HVA levels of the total 188 samples in this study were 11.9 +/- 1.39 and 22.9 +/- 2.92 micrograms/mg creatinine with coefficients of variation (CVs) 11.7% and 12.8%, respectively; and of 76 samples from 5 to 12 months of age, 12.3 +/- 0.84 and 23.1 +/- 2.03 micrograms/mg creatinine with CVs 6.8% and 8.8%. The CVs of VMA and HVA levels expressed in microgram per milligram of creatinine had decreased after 6 months of age (VMA, 5.0% to 8.3%, HVA, 5.3% to 8.4%). Chromatograms demonstrated the similar pattern from 1 to 12 months of age, although the infant had been fed foods typical in Japan, which included breast milk, seasonal fruits, vegetables, fish, chicken, and meat. Diurnal fluctuations of VMA and HVA levels in urine were not significant. When HPLC is used for measurement of VMA, HVA, and creatinine, it is not necessary to restrict foods that cause false-positive results in the qualitative VMA test from the infant's diet. Furthermore, random urine samples obtained throughout the 12 months could be effectively used for the measurement of these substances.

Chromatography, High Pressure Liquid↗
PubMed1992

Crystallization and preliminary X-ray studies of a Bacillus subtilis and Thermus thermophilus HB8 chimeric 3-isopropylmalate dehydrogenase and thermostable mutants of it.

A new type of chimeric 3-isopropylmalate dehydrogenase (2T2M6T) was produced by expressing the fused gene of Bacillus subtilis and Thermus thermophilus. The enzyme shows heat stability intermediate between those of the parents. The crystal of the enzyme belongs to the space group of P3(2)21, with cell dimensions of a = b = 78.9 A and c = 158.9 A. Two thermostable mutants of the chimeric enzyme were prepared by site-directed mutagenesis and then crystallized.

3-Isopropylmalate Dehydrogenase↗
PubMed1992

Hepatocellular carcinoma: treatment with percutaneous ethanol injection and transcatheter arterial embolization.

The therapeutic effectiveness of a new combination therapy--pretreatment with transcatheter arterial embolization (TAE) and subsequent percutaneous ethanol injection (PEI)--for solitary large (> 3.0 cm in diameter) primary hepatocellular carcinoma lesions was compared with that of TAE alone. With TAE alone, a partial response of the tumor was seen in only 10% of the patients, and the 1-, 2-, and 3-year survival rates were calculated to be 68%, 37%, and 0%, respectively. Histologic examination of specimens obtained at hepatectomy showed that TAE alone caused complete necrosis in only 20% of the tumors. In contrast, PEI combined with TAE significantly (P < .05) increased the partial response rate (45%) and significantly (P < .01) prolonged the 1-, 2-, and 3-year survival rates (100%, 85%, and 85%, respectively). Combination therapy caused complete histologic necrosis in 83% of the tumors. It also was significantly (P < .05) better than TAE alone in terms of rate of primary tumor recurrence during follow-up.

Aged↗
PubMed1992

Color Doppler sonography of hepatocellular carcinoma before and after treatment by transcatheter arterial embolization.

Color Doppler sonographic findings on 38 lesions in 31 patients who had primary hepatocellular carcinoma were evaluated before and after transcatheter arterial embolization and compared with dynamic CT and hepatic arteriographic findings. All lesions that were observed with dynamic CT or arteriography were correctly identified on color Doppler sonography. Peritumoral pulsatile flow was the predominant color Doppler flow seen in all lesions. Mixed pulsatile and continuous flow were noted in larger tumors and in tumors with a higher degree of vascularity, as determined by arteriography. Two weeks after treatment, color Doppler flow was still identified in 18 lesions (47%), corresponding to dynamic CT or arteriographic findings documenting residual tumor. Histopathologic examination, performed in 10 other lesions, showed that the tumor was completely necrotic in five. These five necrotic tumors were not visible on color Doppler flow images after treatment. Viable tumor was observed in the five remaining lesions, all of which were shown on color Doppler flow images after treatment. During the 6- to 16-month follow-up period, color Doppler flow images showed recurrence of 13 (50%) of 26 lesions, corresponding to tumor recurrence as shown by CT and arteriography. We conclude that color Doppler sonography is useful for imaging hepatocellular carcinoma, for evaluating residual tumor after treatment, and for imaging tumor recurrence during follow-up.

Aged↗
PubMed1992

Studies on cephalosporin antibiotics. VI. Synthesis, antibacterial activity and oral efficacy in mice of new 7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-(hydroxyimino)-acetamido]-3- (substituted alkylthio)cephalosporins.

A series of new 7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-(hydroxyimino)acetamido] cephalosporins (1) having various substituted alkylthio groups at the C-3 position of the cephem nucleus were prepared and evaluated for antibacterial activity and oral absorption in rats. Of these, the cephalosporin with a cyanomethylthio group (1a) showed the greatest activity against Staphylococcus aureus and Gram-negative bacteria. Its pivaloyloxymethyl ester (6a), a representative prodrug, exhibited good in vivo efficacy in mice by oral administration. The structure-activity relationships of 1 are also presented.

Administration, Oral↗
PubMed1992

Studies on cephalosporin antibiotics. V. Synthesis, antibacterial activity and oral absorption of new 3-[(Z)-2-methoxycarbonylvinylthio]-7 beta- [(Z)-2-(2-aminothiazol-4-yl)-2-(oxyimino)acetamido]cephalosporins.

A series of new 3-[(Z)-2-methoxycarbonylvinylthio]-7 beta-[(2- aminothiazol-4-yl)acetamido]-cephalosporins (1) having various oxyimino groups (Z-form) at the alpha position of the C-7 side chain was synthesized and evaluated for antibacterial activity and oral absorption in rats. Of these, the cephalosporin (1a) with a hydroxyimino group in the C-7 side chain showed a potent antibacterial activity against Gram-negative bacteria and Gram-positive Staphylococcus aureus as well as good oral absorption in rats. The structure-activity relationships of 1 are also presented.

Absorption↗
PubMed1992

[Studies on ocular alkali burn estimated by the component change of tear fluid and aqueous humor].

In this report, we aimed at examining biochemically the ocular surface damage caused by alkali burn. We used a low concentration of NaOH (less than 0.1 N) and examined the relationship between the ocular surface damage and the concentration of NaOH by examining the changes in components that have been released from corneoconjunctival tissues to the tear fluids by alkali burns, and we also examined the effects of eye rinsing and using topical ophthalmic agents. As a result, NaOH of more than 0.03 N was proven to cause the ocular surface damage. The changes of glutathione in tear fluids showed two peaks during the repair process and that coincided with the morphological changes. By measuring the released quantities of three components (glutathione, ascorbic acid and protein) with the use of three methods of alkali burns (corneoconjunctival pooling method, corneal cylinder method and conjunctival pooling method), we could estimate the slight corneoconjunctival damage using one sample biochemically. Moreover, the importance of eye rinsing was quantitatively demonstrated.

Alkalies↗
PubMed1991

Age-related decrease in plasma growth hormone: response to growth hormone-releasing hormone, arginine, and L-dopa in obesity.

Aging is associated with a reduction in plasma growth hormone (GH) secretion in non-obese subjects. To determine whether or not age-related changes in plasma GH secretion exist in obese subjects, we measured (a) plasma GH response to growth hormone-releasing hormone (GRH; 1 microgram/kg body wt), arginine (0.5 g/kg body wt), L-dopa (500 mg), and (b) plasma glucose, insulin, and free fatty acids (FFAs) in 26 fasted obese subjects of various ages ranging from 16 to 71 years. Only subjects with a body mass index (BMI; kg/m2) between 30.0 and 39.0 were studied. Six subjects were adolescents, 9 were in their 20s, and 11 were 30 years or older. The mean peak levels of plasma GH in response to GRH, arginine, and L-dopa in obese subjects were 11.3 +/- 2.1, 21.9 +/- 4.4, and 5.2 +/- 0.3 ng/mL in adolescents, 8.2 +/- 1.6, 9.1 +/- 1.5, and 3.1 +/- 0.6 ng/mL in those in their 20s, and 4.5 +/- 0.4, 7.3 +/- 1.4, and 2.8 +/- 0.3 ng/mL in those 30 years or older, respectively, showing a significant decrease in peak GH level with advancing age (P less than .05 to P less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Effects of isoflurane and fentanyl on ischemic myocardium in dogs: assessment by end-systolic measurements.

The effect of anesthetics on ischemic myocardium to which blood was supplied by a stenotic coronary artery was investigated in dogs. The ischemia was assessed by regional wall motion (ultrasonic dimension technique) using fractional shortening (FS) [(EDL - ESL)/EDL x 100] and end-systolic pressure-segment length relationships (ESPLR). The latter is considered to be a more load-independent measure of regional myocardial function. Isoflurane and fentanyl were chosen as anesthetics of current interest. On reducing the left circumflex coronary artery (LCX) flow to approximately 50% of its resting value, a decrease in FS and a rightward shift in ESPLR were observed in myocardium perfused by the LCX. Simultaneously, increases in FS were observed in the nonischemic area perfused by the left anterior descending coronary artery (LAD), which was most likely due to the intraventricular unloading effect. No significant changes of ESPLR were observed in the area supplied by LAD. Isoflurane induced a dose-dependent decrease in FS and a rightward shift in ESPLR in the ischemic myocardial segment, whereas fentanyl caused an increase in FS and tended to shift ESPLR leftward in the same area. The results suggest that isoflurane may have deleterious effects on preexisting myocardial ischemia, whereas fentanyl may not when loading conditions are taken into consideration. Fractional shortening and ESPLR seem to provide similar information about regional myocardial function.

Anesthesia, Inhalation↗
PubMed1991

[Usefulness of recombinant human erythropoietin in cardiac surgery with autologous blood transfusion].

The efficacy and method of administration of recombinant human erythropoietin (EPO) in adult cardiac surgical patients when given preoperatively was evaluated. We used EPO intravenously (iv) with 40 mg ferric oxide for a total of consecutive 47 patients. The patients were divided into group A (n = 14; EPO 200 IU/kg iv 3 times a week from 3 weeks prior to surgery to 2 weeks after surgery, donation of 800 ml) and group B (n = 33; EPO 200 IU/kg iv everyday from 8 days prior to surgery to 2 weeks after surgery, donation of 400 ml). Control groups were group AO (n = 11; donation of 835 +/- 33 ml from 14.8 days prior to surgery) and group BO (n = 7; donation of 406 +/- 34 ml at 7.3 days prior to surgery). All the EPO-treated patients received no homologous blood transfusion while 2 of patients in group BO received some homologous blood transfusion. A hemoglobin change between pre-donation and surgery was +0.14 +/- 1.3 (g/dl) in group A, +0.04 +/- 1.0 (g/dl) in group B, -1.7 +/- 1.3 (g/dl) in group AO and -1.0 +/- 0.6 (g/dl) in group BO. In a comparison of post-surgical hemoglobin levels between group A and group B, we demonstrated that the level in group B, +2.1 +/- 1.8 (g/dl) was significantly higher than that in group A, +11.1 +/- 1.6 (g/dl) 2 weeks after surgery. There was no evidence to show an aggravation of anemia in the pre-surgical period in EPO-treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia↗
PubMed1990

Very-low-calorie diet-induced weight reduction reverses impaired growth hormone secretion response to growth hormone-releasing hormone, arginine, and L-dopa in obesity.

To determine whether impaired growth hormone (GH) secretion in obese subjects is a consequence of obesity or a pre-existing pituitary-hypothalamic disorder, we measured (1) plasma GH response to growth hormone-releasing hormone (GRH; 1 microgram/kg body weight [BW]), arginine (0.5 g/kg BW), and L-dopa (500 mg); and (2) plasma glucose, insulin, and free fatty acids (FFA) in obese subjects before and after weight reduction due to very-low-calorie diet therapy using Optifast (240 kcal/d for 8 to 12 weeks). Body weight and body mass index (BMI) values before and after weight reduction were 87.2 +/- 4.1 kg and 34.5 +/- 0.9 kg/m2, and 67.8 +/- 2.7 kg and 27.0 +/- 0.4 kg/m2, respectively. GH response to GRH, arginine, and L-dopa in obese subjects was markedly impaired before weight reduction, whereas significantly increased responses were noted after weight reduction (P less than .01). Impaired integrated GH response to GRH, arginine, and L-dopa in obese subjects was significantly restored after weight reduction (P less than .01). Plasma glucose levels did not change, while plasma insulin and FFA levels decreased significantly after weight reduction (P less than .01, P less than .05). There was no significant correlation between integrated GH response to these three stimuli and plasma levels of glucose, insulin, and FFA, respectively. The reversibility of GH response to all three stimuli after weight reduction suggests that impaired GH secretion is a consequence of obesity rather than a pre-existing pituitary-hypothalamic disorder.

Adolescent↗
PubMed1990

The susceptibility of Campylobacter pylori to antiulcer agents and antibiotics.

The antibacterial activities of antiulcer agents and antibiotics against Campylobacter pylori were studied. The MIC90 values of three kinds of antibiotics--macrolides, beta-lactams, and metronidazole--were 0.05-0.78, 0.39-1.56, and 12.5 micrograms/ml, respectively. They were more active than antiulcer agents such as H2-blockers and cetraxate with MIC90 values of greater than or equal to 1,600 and greater than 1,600 micrograms/ml, respectively. Especially, clarithromycin, a new derivative of erythromycin, showed an MIC90 of 0.05 microgram/ml. However, the other antiulcer agents such as sofalcone and tripotassium dicitrate bismuthate (TDB) also had MIC90 values of 50 and 6.25 micrograms/ml, respectively. Clarithromycin, sofalcone, and TDB showed bactericidal activity against C. pylori CLO2. The bactericidal actions of these drugs could be observed under electron microscopy.

Anti-Bacterial Agents↗
PubMed1990

Chemical modification of erythromycins. III. In vitro and in vivo antibacterial activities of new semisynthetic 6-O-methylerythromycins A, TE-031 (clarithromycin) and TE-032.

The in vitro and in vivo antibacterial activities of 6-O-methylerythromycin A (TE-031, A-56268, or clarithromycin) and 6,11-di-O-methylerythromycin A (TE-032) have been compared with those of erythromycin A (EM) and josamycin (JM). TE-031 and TE-032, having the same antibacterial spectra as EM, are active against aerobic Gram-positive bacteria, some Gram-negative bacteria, anaerobic bacteria, L-form bacteria and Mycoplasma pneumoniae. The activity of TE-031 against clinical isolates is equal to or two times more potent than that of EM, whereas TE-032 is slightly less active than EM. The activities of TE-031 and TE-032 are pH dependent (more active at pH 8 than at 5) and are increased by adding serum to medium. TE-031 and TE-032 show dose-related bactericidal activities against Haemophilus influenzae. The therapeutic efficacies of TE-031 and TE-032 against systemic and subcutaneous infections provoked by Gram-positive bacteria in mice are 4- to 35-fold superior to those of EM and JM. TE-031 and TE-032 have demonstrated higher and longer-lasting plasma levels than EM when administered orally to mice, rats or dogs.

Animals↗