Biomedical subjects

Y Kondo

Publications and source records attributed to Y Kondo.

At least 271 records · Page 15Linked to original sources

PubMed1998

2-(3-Pyridyl)thiazolidine-4-carboxamide derivatives. II. Structure-activity relationships and active configuration of 2-(3-pyridyl)thiazolidine-4-carboxamides as platelet-activating factor receptor antagonists.

Conversion of the 2-(3-pyridyl)thiazolidine part of 1-(3-phenylpropyl)-4-[2-(3-pyridyl)thiazolidine-4-carbonyl]piperazine (YM461), which is a potent platelet-activating factor (PAF) antagonist, to other rings was performed, and PAF antagonistic activities evaluated. The 2-(3-pyridyl)thiazolidine skeleton, which exists as a mixture of cis and trans diastereomers, played an important role in the potency of PAF antagonism. In this study, new effective skeletons were not uncovered, however, 2-(4-pyridyl)thiazolidine-4-carboxamides (1n and 1z) showed potent PAF antagonistic activities equal to the 3-pyridyl derivatives. From the results obtained for 1a, 1a(S), 1g and 1i, a cis-(2R,4R)-2-(3-pyridyl)thiazolidine-4-carboxamide was assumed to be the active configuration for PAF antagonism.

Animals↗

PubMed1998

Coronary-pulmonary artery fistulae depicted by multiplanar reconstruction using magnetic resonance imaging.

We compared the imaging capability of magnetic resonance angiography (MRA) with that of conventional coronary angiography in a patient with coronary-pulmonary fistulae. Using the latter procedure, it is difficult to measure abnormal tortuous blood vessels in one section. However, the course of blood vessels could be evaluated quite well by rearranging serial cross-sectional MRA images using multiplanar reconstruction (MPR). This procedure allowed us to determine the anatomic positional relationship of these vessels to the peripheral cardiac great vascular system. MPR may detect sites of influx and outflow of abnormal blood vessels.

Adult↗

PubMed1998

Use of fluid-attenuated inversion recovery (FLAIR) pulse sequences in perinatal hypoxic-ischaemic encephalopathy.

The purpose of this study was to evaluate the usefulness of fluid-attenuated inversion recovery (FLAIR) techniques in patients with perinatal hypoxic-ischaemic encephalopathy. 13 patients with a history of perinatal hypoxic-ischaemic encephalopathy (age range 1 month to 3.6 years) underwent T1 and T2 weighted spin echo and FLAIR imaging with a 1.5 T superconducting unit. FLAIR images were qualitatively evaluated in comparison with T1 and T2 weighted images by three experienced radiologists. Quantitative analysis (contrast and contrast-to-noise ratio) was also performed. FLAIR images were preferred to T1 and T2 weighted images in the demonstration of periventricular leukomalacia (PVL), cystic PVL and subcortical lesions near the brain surface. On T1 and T2 weighted images, almost all lesions were demonstrated as hypointense or hyperintense areas, respectively. However, FLAIR images could differentiate cystic lesions by their signal intensities. FLAIR images were not diagnostic in two cases with PVL. In conclusion FLAIR sequences provide useful information in patients with perinatal hypoxic-ischaemic encephalopathy.

Child, Preschool↗

PubMed1998

Vascular responsiveness in alloxan-induced diabetes-susceptible (ALS) and resistant (ALR) mice.

Changes in reactivity of vascular smooth muscles of male alloxan-induced diabetes-susceptible (ALS) and resistant (ALR) mice aorta were investigated at 2 weeks, 1, 2 and 4 month(s) after the injection of alloxan (45 mg/kg, i.v.). The glucose levels in blood and urine of all the alloxan-treated ALS mice were markedly elevated while those in alloxan-treated ALR and non-treated ALS and ALR mice were not altered. The magnitude of high K+ (65.4 mM)-induced contractions were not affected by the treatment of alloxan. Norepinephrine-induced contractions in vascular smooth muscles of ALS mice in a diabetic state for 2 or 4 months were significantly potentiated. The contractile sensitivity to prostaglandin F2 alpha (PGF2 alpha) was increased in the 4-month-diabetic state. Responsiveness to 5-HT did not vary in the diabetic mouse. Vasorelaxation induced by nitroprusside was attenuated in 2 weeks, 2 or 4 month-diabetic ALS mice. Similarly the inhibitory effects of levcromakalim were attenuated at 2 and 4 months. The influences of diabetes on the inhibitory effects of forskolin or verapamil were very small or not detected. The effects of the vasomodulators used in this study on the vascular smooth muscles of alloxan-treated ALR mice did not differ from those of untreated ALR mice. The results from using ALS and ALR mice suggest that the vasoreactivities to some vasomodulators are changed especially in the long-term diabetic state and that when diabetes was not induced the dose of alloxan does not have any effect on vascular smooth muscle.

Alloxan↗

PubMed1998

Temporal coincidence between the excitation of ventromedial hypothalamic efferents and the induction of lordosis reflex in ovariectomized estrogen-primed rats.

The temporal changes in excitability in ventromedial hypothalamic neurons which project to the midbrain central gray caused by chronic estrogen exposure were measured in ovariectomized rats. In 66 urethane-anesthetized animals which had either no capsule, or had a capsule containing estrogen implanted for 24 h, 48 h, 72 h or 96 h, 189 antidromic action potentials were recorded in the ventromedial hypothalamus (VMN) in response to stimulation of the midbrain central gray (CG). The antidromic activation threshold was lower in 40 recordings made from the VMN in the 72-h or 96-h group than in 67 from the no-treatment, 24-h or 48-h group. The decrease in the threshold coincided with the emergence of the lordosis reflex. In a separate cohort of ovariectomized rats, any absence of estrogen for 2-48 h before and during the measuring abolished the neuronal as well as the behavioral effects at 72 h. The results suggest that the lordosis reflex induced by estrogen alone depends on the excitation of VMN efferents to the CG. In addition, the indispensability of estrogen at the time of electrophysiological and behavioral evaluation indicates that a certain direct neural action of estrogen is involved in the behavioral activation.

Animals↗

PubMed1998

Effects of intravenous administration of L-arginine on autonomic nervous activities. Analysis of heart rate variability.

We studied the differences between isosorbide dinitrate (ISDN) and L-arginine (L-Arg), the precursor of nitric oxide, regarding autonomic nervous function by assessing changes in heart rate variability and blood levels of various vasoactive substances. Healthy volunteers received infused L-arginine (L-Arg group) or isosorbide dinitrate (ISDN group). ECGs were monitored and analyzed. Blood levels of catecholamines, endothelin, renin activity, angiotensin, human atrial natriuretic peptide, aldosterone, arginine, and citrulline were examined. Time-domain analyses of heart rate variability showed no significant changes in occurrence of R-R variability or coefficient of R-R variability, indicators of parasympathetic activity, after administration of ISDN. By contrast, both measures showed significantly more variation following administration of L-Arg. Frequency-domain analyses showed that high frequency power, an indicator of parasympathetic activity, was significantly elevated in the L-Arg group, whereas there was no significant change in the ISDN group. The blood levels of the measured vasoactive substances in L-Arg and ISDN groups were significantly different. The differences in autonomic nervous function and various kinds of vasoactive substances between the L-Arg and ISDN groups suggest that L-Arg had other actions on humoral factors in addition to vasodilation. Thus, arginine/nitric oxide may act as a neurotransmitter, altering parasympathetic nervous tension.

Adult↗

PubMed1998

A comparative genetic map of rat, mouse and human genomes.

The increasing availability of molecular markers and the development of highly efficient gene mapping strategies for the mouse, rat and human genomes have generated vast quantities of information allowing for the progressive refinement of comparative maps. In this publication we report on an updated version of our rat/mouse/human comparative genetic map, based on the mouse map. Databases for mouse, rat and human gene mapping were used for the collection of homologs mapped in the species. The comparative map was constructed with a total of 1,235 mouse loci having known homologs in the rat and/or human: 16 having homologs only in the rat, 884 having only in the human and 335 both in the rat and human. The combined length of the segments conserved between the rat and mouse spans 758 cM on the mouse map. This indicates that about 47% of the mouse genome is now covered by known rat homologous regions. Five novel regions homologous for the rat and mouse were identified. This comparative genetic map should be useful for researchers working on genetic studies in the rat, mouse and human.

Animals↗

PubMed1998

Mutations in CLCN5 chloride channel in Japanese patients with low molecular weight proteinuria.

Mutations in the CLCN5 gene have been demonstrated in three disorders of hypercalciuric nephrolithiasis, i.e., Dent's disease, X-linked recessive nephrolithiasis, and X-linked recessive hypophosphatemic rickets. Recently, a number of Japanese children with low molecular weight proteinuria (LMWP) showing symptoms similar to those shown by patients with Dent's disease in British families have also been reported to have mutations in the CLCN5 gene. The present study examines five unrelated Japanese families with LMWP, two of which lacked any signs other than LMWP, and three of which had several signs other than LMWP, i.e., hypercalciuria, aminoaciduria, hypophosphatemia, and rickets. One nonsense (E118X) and one missense (W22G) mutation were found in three patients in the two families having only LMWP. One genomic deletion including exons 5 to 8 in the CLCN5 gene was found in a patient with hypophosphatemic rickets, and a nonsense mutation (R347X) was found in one patient with LMWP and slight hypercalciuria. No mutations of the exons and exon-intron boundaries in the CLCN5 gene were found in one patient with LMWP, aminoaciduria, and hypokalemia. In addition to the predicted loss of chloride channel function in these nonsense and deletion mutations, the loss of function in the missense mutation W22G was confirmed in the Xenopus oocyte expression system. These results clarified four novel mutations in the CLCN5 genes, and additionally suggested that the loss-of-function mutation of the CLCN5 does not necessarily lead to hypercalciuria and nephrocalcinosis in the early stage of the disease, and that LMWP is an early and essential manifestation of disorders of the CLC-5 chloride channel.

Adult↗

PubMed1998

Cerebrospinal ascites developed 3 years after ventriculoperitoneal shunting in a hydrocephalic patient.

We report a 23-year-old woman who developed ascites 3 years after ventriculoperitoneal shunting. Revision of the shunt to ventricular drainage followed by ventriculo-atrial shunting was required for resolution of ascites. In our patient the pathophysiology of this rare shunt complication most likely involved impaired absorption of fluid within the peritoneum associated with multiple shunt reconstructions and tube extensions resulting in chronic inflammation. Cerebrospinal ascites must be suspected irrespective of post-shunt intervals in similar patients.

Adult↗

PubMed1998

GB virus C/hepatitis G virus infection among Colombian native Indians.

To elucidate the prevalence of GB virus C/hepatitis G virus (GBV-C/HGV) infection in Colombian native Indians, serum GBV-C/HGV RNA was assayed in 163 native Indians and 67 members of the general population in Colombia. The native Indians (males:females = 40:123) and the members of the general population (males:females = 20:47) were tested by reverse transcription-semi-nested polymerase chain reaction. Of the 163 native Indians, 10 (6.1%) were positive for GBV-C/HGV RNA, compared with one (1.5%) of 67 from the general population. All Indians were negative for hepatitis B surface antigen and antibody to hepatitis C virus. Of 10 Indians with GBV-C/HGV RNA, the genotype of nine subjects was the Asian type. These data indicated that 1) the prevalence of GBV-C/HGV RNA in Colombian native Indians is high, and 2) GBV-C/HGV was probably brought from Asia and inherited for generations in some native Indian groups.

Adolescent↗

PubMed1998

[Irreversible airflow limitation in asthmatics].

To evaluate irreversible airflow limitation in asthmatics, we studied 168 patients admitted to our hospital with acute exacerbation of asthma. All patients were given intravenous methylprednisolone for at least 7 days to maximum 14 days and the best of PEF (% of predicted) was evaluated. In all subjects, the best of PEF showed significant correlations with both the patients' age (r = -0.411, p < 0.0001) and the duration of asthma (r = -0.494, p < 0.0001). A significant correlations between the best of PEF and the duration of asthma were also observed in both patients over 60 years old (r = -0.157, p < 0.0001) and non-smokers (r = -0.568, p < 0.0001). We conclude that asthma may develop irreversible airflow limitation in itself and the degree of impairment of lung function correlated with the duration of the disease.

Airway Obstruction↗

PubMed1998

[Cure by THP-COP therapy in patients with perforated T-cell type malignant lymphoma of the jejunum].

A 52-year-old man had suffered abdominal pain from Dec. 15, 1992. On Jan. 1993, he was admitted to our hospital for a diagnosis of T-cell malignant lymphoma of stomach of diffuse large cell type by gastroendoscopical biopsy. On the following day, he underwent emergency an operation with a diagnosis of panperitonitis. A perforation site had been found at the jejunum 60 cm distant from the Treitz ligament. It was resected and sutured concomitant with omental patch. The pathological diagnosis was the same. After the operation, we started THP-COP therapy on Jan. 25, 1993. During the admission, he was given THP-COP therapy 6 times, and had a complete remission. He was discharged Feb. 26, 1994, and shows no evidence of disease at this writing.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1998

Comparison of calculated nasal resistance from Röhrer's equation with measured resistance at delta P150Pa.

Values of nasal resistance at delta P150Pa have been recommended by the International Standardization Committee for clinical use. However, this point seems somewhat high for quiet nasal breathing. To determine the usefulness of calculated nasal resistance at delta P150Pa from Röhrer's equation when transnasal pressure fails to reach the point, the values at delta P150Pa calculated from the method have been compared with actually measured nasal resistances at delta P150Pa by active anterior rhinomanometry with a nasal nozzle. The mean value of measured unilateral nasal resistance in 75 patients is 0.513 +/- 0.511 Pa/cm3/s on expiration and 0.335 +/- 0.193Pa/cm3/s on inspiration. The mean value of calculated nasal resistance from Röhrer's equation is 0.511 +/- 0.515Pa/cm3/s on expiration and 0.337 +/- 0.207Pa/cm3/s on inspiration. Correlations between measured and calculated nasal resistances have been assessed and are almost identical in both expiration and inspiration. Calculated nasal resistance at delta P150Pa from Röhrer's equation seems to be suitable for evaluation when transnasal pressure fails to attain the point.

Adolescent↗

PubMed1998

Importance of the medial amygdala in rat penile erection evoked by remote stimuli from estrous females.

Effects of medial amygdala lesions (MAL) were examined on rat penile erection in three different experimental situations. Only sexually vigorous males, as identified by preoperative mating tests, were used. Bilateral radiofrequency lesions were confined to the posterior medial amygdala, with little systematic damage to anterior medial amygdala or to adjacent structures. Lesion electrodes were withdrawn without current application in sham-operated animals (SHAM). After recovery for brain surgery, males were tested for (1) noncontact erection (NCE) that occurs when males were placed in proximity to inaccessible estrous females, (2) reflexive erection evoked in supine males by retraction of the penile sheath, and (3) copulatory behaviour with receptive females. In the NCE test, none of the MAL males showed penile erection during the 20 min observation, whereas 70% of the SHAM males showed it (P < 0.001). In contrast, no erectile dysfunction in the MAL males was detected in the other two tests. MAL males displayed more penile-body erections (flips) than SHAM males in the reflexive-erection test (P <0.05). In the copulation test, most of the MAL males achieved intromission, but their intromission ratio, a partial measure of erectile function, was marginally lower than that of SHAM males (P = 0.051). MAL males had longer intervals between intromissions (P < 0.001); as a result, none of them ejaculated during the 30 min period that followed the first intromission. The results suggest that the posterior medial amygdala plays an essential role in the regulation of NCE, and it may also contribute to the regulation of erection in other contexts.

Amygdala↗

PubMed1998

[Adrenal pheochromocytoma associated with renal cell carcinoma: report of two cases].

Two cases of adrenal pheochromocytoma associated with renal cell carcinoma are reported. The first case was in a 56-year-old woman who had been treated for hypertension. Computerized tomography (CT) scan revealed a right renal tumor and a right adrenal mass. Endocrinological examination and 131I-MIBG scintigraphy confirmed the diagnosis of pheochromocytoma. Right radical nephrectomy was performed under stable blood pressure. The second case was in a 45-year-old man who had been treated for gastric ulcers. CT scan incidentally revealed a right renal tumor and a left adrenal mass. He was normotensive and endocrinologically normal. Right radical nephrectomy and left adrenalectomy were performed, followed by corticosteroid supplementation. In both cases, histopathological diagnosis was renal cell carcinoma and adrenal pheochromocytoma. Both patients had no clinical evidence for von Hippel-Lindau disease such as tumorous lesions of the central nervous system, spinal cord and retina, and cystic lesions of the kidney and pancreas.

Adrenal Gland Neoplasms↗

PubMed1998

Heterogeneity in E2 region of GBV-C/hepatitis G virus and hepatitis C virus.

GB virus C/hepatitis G virus (GBV-C/HGV) is related distantly to hepatitis C virus (HCV). HCV has a hypervariable region (HVR), and exists as quasispecies in vivo. Although GBV-C/HGV also has replaceable amino acids in the presumed antigenic region, the existence and fluctuation of population of heterogeneous virus have not been evaluated. In this study, the heterogeneity of GBV-C/HGV and HCV was investigated by the single-strand conformation polymorphism (SSCP) analysis in six concomitantly infected patients. Two patients were observed for 4 years without any treatment, and four were treated with interferon-alpha (IFN). By SSCP analysis, amplicons of GBV-C/HGV RNA were separated into 1-5 bands on gels for each patient. The amplicons had different nucleotide but the same amino acid sequences in the presumed antigenic region. The amplicons of HCV RNA, separated into 1-4 bands, had different nucleotide and amino acid sequences in the HVR. In the two patients without treatment, the predominant strain of GBV-C/HGV was unchanged for the 4 years. In the four patients administered IFN, some strains of GBV-C/HGV disappeared after IFN therapy, whereas other strains persisted. The mean genetic distance among GBV-C/HGV strains represented by SSCP analysis was significantly lower than that of HCV (P < 0.05). The data indicate that: 1) GBV-C/HGV can be devoid of antigenic drift unlike HCV; 2) GBV-C/HGV has no HVR as seen in HCV in the presumed antigenic region; and 3) the sensitivity to IFN differs among GBV-C/HGV strains in the same hosts, as with HCV.

Adult↗

PubMed1998

A frequency-doubling perimetric study in normal-tension glaucoma with hemifield defect.

PURPOSE: The authors prospectively compare perimetric results obtained by conventional differential light sensitivity (DLS) perimetry and frequency-doubling perimetry (FDP) in normal-tension glaucoma (NTG) with a hemifield visual field defect, assuming that some of these eyes already have early glaucomatous changes in the "intact" hemifield. METHODS: Eleven eyes of 11 patients with NTG who met the enrollment criteria were studied. Seven eyes had an upper hemifield defect and four had a lower defect, determined by DLS with a Humphrey Field Analyzer (Zeiss-Humphrey, Inc., San Leandro, CA, U.S.A.). Frequency-doubling perimetry and DLS perimetry were conducted less than 7 days apart. To quantitatively detect nerve fiber layer defect (NFLD), scanning laser ophthalmoscopy was also performed. RESULTS: Of the 11 intact hemifields, seven showed NFLD. Of the seven, six also showed visual field defects by FDP. Of the four eyes without NFLD, two showed no defects in the intact hemifield by FDP. The threshold values of FDP and DLS perimetry did not significantly correlate in either the intact or the defective hemifields, or in the total field. The average test time of FDP was approximately 6 minutes. CONCLUSIONS: Frequency-doubling perimetry may detect early glaucomatous visual field defects.

Adult↗

PubMed1998

[Age-related changes of electrocardiographic wave].

Magnetocardiograms (MCGs) were recorded by means of a second-derivative SQUID (superconducting quantum interference device) magnetometer in 150 normal subjects (25-34 years old, 30 cases; 35-44 years old, 30 cases; 45-54 years old, 30 cases; 55-64 years old, 30 cases; 65-74 years old, 30 cases) to investigate whether cardiac current would change with age. Based on these MCG records at 36 points on the anterior chest wall, isomagnetic maps during QRS wave were constructed, and dipole moments was calculated mathematically. The amplitude of RV5 and SV1 + RV5 in ECG were larger in 65-74-year-old women compared to those in women of other ages, and SV1 + RV5 was smaller in 45-74-year-old men compared to those in 25-44-year-old men. However, dipole moments deduced from MCG did not differ with age. These results suggest that age-related changes in the amplitude of QRS wave in ECG do not affect the change in electromotive force with aging.

Adult↗