Search PubMed⌕ Search

Biomedical subjects

H Okada

Publications and source records attributed to H Okada.

At least 415 records · Page 23Linked to original sources
PubMed1997

Image cytometry for quantitative analysis of DNA in the testes of infertile men with varicocele: comparison with flow cytometry.

PURPOSE: The first aim of this study is to evaluate the usefulness of image cytometry comparing flow cytometry to analyze the spermatogenesis using testicular biopsy specimens obtained from infertile male. The second is to investigate the spermatogenesis of infertile men with varicocele by image cytometry. MATERIALS AND METHODS: A total of 76 biopsy specimens of testicular tissue were obtained from 38 infertile men with varicocele and 6 specimens of normal testicular tissue controls were obtained from 6 volunteers at vasectomy. They were evaluated by image cytometry and pathohistological examination. Out of 76 specimens, 21 biopsy tissues were also analyzed by flow cytometry, and the results by both image cytometry and flow cytometry were compared. Two specimens from Sertoli cell only testes were also examined by image and flow cytometry. RESULTS: In comparative study, image cytometry revealed a decrease in the proportion of haploid and diploid cells (18.8 +/- 6.6% and 32.4 +/- 7.4%), and an increase in that of tetraploid cells (21.8 +/- 5.6%) vs. the flow cytometry findings (haploid, 25.9 +/- 9.2%; diploid, 36.8 +/- 6.5% and tetraploid, 15.1 +/- 5.9%). Image cytometric analysis of the testes of varicocele patients showed 15.9 +/- 5.6% haploid, 31.7 +/- 7.9% diploid and 16.2 +/- 8.9% tetraploid cells in the left testis of infertile men, while their right testis showed 16.6 +/- 5.4% haploid, 30.0 +/- 7.6% diploid and 17.2 +/- 6.4% tetraploid cells. The testes of normal men showed 37.6 +/- 8.3% haploid, 19.4 +/- 4.8% diploid and 17.4 +/- 5.8% tetraploid cells. The left and the right testes of the patients with varicocele showed a lower proportion of haploid cells and a higher proportion of diploid cells vs. the testes from normal men. The proportions of the haploid and diploid cells are correlated with sperm concentration. CONCLUSION: Image cytometry could exclude interstitial cells, Sertoli cells, and sperm on the static image, so produced an accurate assessment of spermatogenesis. The alteration in the germ cell population in the testes of infertile men with varicocele suggested that the impairment mostly affected the cells in the meiotic stage.

Adult↗
PubMed1997

Anti-asthma effect of an antiviral drug, acyclovir: a clinical case and experimental study.

BACKGROUND: Although acyclovir (9-(2-hydroxyethoxymethyl) guanine) is an antiviral drug that inhibits DNA polymerase of herpes virus, we have had the experience of an asthmatic patient's peak flow rate being improved by oral administration of acyclovir. OBJECTIVE: The aim of this experiment is whether acyclovir has anti-asthma effects using an asthma model in guinea-pigs. METHODS: The airway response was induced by a single inhalation of calcium ionophore A23187 (2 mg/mL). The airway obstruction was estimated by the ratio of expiration to inspiration time (E/I). The peribronchial eosinophil infiltration and eosinophil influx into bronchoalveolar lavage (BAL) fluid 7 h after the inhalation were also examined. To assess the effects of acyclovir (1, 10, and 100 mg/kg), aminophylline (20 mg/kg) and pemirolast potassium (TBX, 20 mg/kg) on A23187-induced asthmatic response, the drugs were intraperitoneally administered before the inhalation. RESULTS: The immediate airway obstruction was significantly suppressed by acyclovir (10 mg/kg) and aminophylline, whereas different doses of acyclovir (1 and 100 mg/kg) and TBX showed only a small inhibitory effect on the airway obstruction. On the other hand, the peribronchial eosinophilia was most successfully inhibited by TBX. Acyclovir (10 mg/kg) and aminophylline also suppressed the eosinophilia significantly. Furthermore, acyclovir significantly suppressed eosinophil influx into BAL fluid, whereas aminophylline and TBX weakly suppressed the influx. CONCLUSION: These results suggest that acyclovir exhibits not only antiviral but also antiasthma activity.

Acyclovir↗
PubMed1997

[Protection afforded by a novel K channel opener (Y-26763), against glycerol-induced acute renal failure (ARF) in rats].

Y-26763, a benzopyran derivative, is a newly developed ATp-sensitive K channel opener and has been reported to protect against ischemic acute renal failure (ARF). We examined the effects of Y-26763 on glycerol-induced myoglobinuric ARF in the rats. ARf was induced in 28 adult male Sprague-Dawley rats by hind-limb intramuscular injection of 50% glycerol (5 ml/kg) after 18 hrs of water deprivation. Y-26763, 7 micrograms/kg (GY group, n = 10) of vehicle (G group, n = 12) was given intravenously 15 min before glycerol injection. Glibenclamide (20 mg/kg), a K channel blocker was given prior to Y-26763 injection to see of the effects was due to the K-channel opener (GYG group, n = 6). Animals were sacrificed 24 or 96 hrs after glycerol injection. Y-26763 partially, but significantly, restored renal dysfunction 24 hrs after ARF. Pcr (mg/dl) and Ccr (ml/min), respectively were as follows: G group, 5.7 +/- 0.4, 0.015 +/- 0.006; GY group, 4.1 +/- 0.4, 0.061 +/- 0.027 (p < 0.05). These favorable effects were antagonized by glibenclamide (Pcr in GYG group, 5.4 +/- 0.3 mg/dl, p < 0.05). Renal calcium content was not statistically significant (3.5 +/- 1.2 vs. 3.4 +/- 1.2 micrograms/mg dry weight). Histological examinations revealed that extensive tubular necrosis and cast formation seen in the G group were reduced in the GY group. At the recovery phase, 96 hrs after glycerol injection, Y-26763 accelerated the recovery from ARF as shown in Pcr (mg/dl) and Ccr (ml/min): 4.3 +/- 0.2, 0.05 +/- 0.01 in the G group, 2.8 +/- 0.2, 0.13 +/- 0.02) in the GY group (p < 0.01). In conclusion, Y-26763 partially protected against glycerol-induced ARF.

Acute Kidney Injury↗
PubMed1997

[Comparison of side effects caused by intra-arterial and intravenous infusion of M-VAC (methotrexate, vinblastine, adriamycin and cisplatin) for urothelial cancer].

We retrospectively studied the toxic effects in 14 patients with urothelial cancer who had undergone intra-arterial M-VAC chemotherapy (Group A) and 13 patients who had received intravenous M-VAC chemotherapy (Group V) between February 1991 and August 1995. No statistically significant differences were found in the white blood cell count nadir, liver function, renal function or appetite between the groups. While the platelet count nadir for intra-arterial infusion (14.0 x 10(4)/mm3) was larger than for intravenous infusion (9.0 x 10(4)), the median days to nadir for this count was shorter in the intra-arterial group (9.1 days) than in the intravenous group (13.5). In addition, the difference between the beginning hemoglobin level and the nadir level was larger in the intra-arterial infusion group (2.55 g/dl) than in the intravenous infusion group (1.95 g/dl). Additionally peculiar side effects were noted in the intra-arterial infusion group which included local erythema and nerve paralysis. Side effects should be managed for intra-arterial M-VAC as well as for intravenous infusion.

Aged↗
PubMed1997

[Low flow anesthesia using a fresh gas flow of 600 ml.min-1 for 5 hours].

Low flow anesthesia (LFA) using a fresh gas flow (FGF) of 600 ml.min-1 with oxygen and nitrous oxide flow each set at 300 ml.min-1, and dial setting of sevoflurane 3% was administered to 30 patients for a duration of 5 hours. There were no problems such as unsuitable concentrations of nitrous oxide and sevoflurane in inspired and expired gases or low FIO2 below 0.3 during anesthesia in 15 patients of group A. Their body weight was 53 +/- 5 kg. FIO2 decreased below 0.29 at about 4 hours in 7 patients of group B weighing 62 +/- 6 kg, and at about 1 h in 8 patients of group C weighing 71 +/- 7 kg. In group A and B, the sum of concentrations of oxygen, nitrous oxide and sevoflurane in inspired gas decreased for a moment and recovered as anesthesia progressed, but in group C, it kept decreasing without recovery. The body weight was significantly different among the 3 groups (P < 0.05). It was suggested that in group A the FGF per body weight was suitable; in group B though oxygen flow was larger than oxygen consumption, hypoxia occurred due to saturation of nitrous oxide in the body; and in group C the FGF was insufficient. The compound A was detected in the breathing circuit, and the concentration was around 20 ppm and it did not depend on the duration of LFA. It was concluded in this study that LFA using the FGF of 600 ml.min-1 with setting of 3% sevoflurane, 50% oxygen and nitrous oxide, could be performed safely without risks such as hypoxia and severe delay of induction for patients weighing 53 +/- 5 kg for a duration of 5 hours.

Adult↗
PubMed1997

Neuroendocrine cells in the prostatic carcinomas after neoadjuvant hormonal therapy.

Prostate cancer is a malignant tumor that is likely to increase in incidence in Japan. The most troublesome facet of this tumor is its conversion from a hormone-sensitive status to an insensitive one. Neuroendocrine differentiation may help explain this phenomenon. We studied the prevalence of neuroendocrine cells in prostate carcinoma after androgen ablation therapy. Radical prostatectomy specimens from 28 patients who had undergone neoadjuvant endocrine therapy with luteinizing hormone-releasing hormone analogue were retrospectively studied. Immunohistochemical staining was used to assess the localization of neuroendocrine cells. Neuroendocrine differentiation index, defined as the sum of the immunoreactivity scores of the specimens against anti-chromogranin A and anti-neuron specific enolase antibodies, was developed. Overall, 46.4% and 53.6% of the prostate carcinomas contained chromogranin A and neuron-specific enolase positive cells, respectively. Localization of these neuroendocrine cells in tumors was patchy. Two specific types of neuroendocrine cells were identified: a closed type and an open type based on the location of the neuroendocrine cells. The neuroendocrine differentiation index correlated with tumor grade, but not with tumor stage. The prevalence of neuroendocrine cells in higher grade prostatic carcinoma may help to explain the insensitivity of these cancers to hormonal therapy.

Adenocarcinoma↗
PubMed1997

Effects of antiendothelin treatment on the early hemodynamic changes in hyperdynamic endotoxemia.

We have performed a series of experiments to study the effects of a newly developed antisense homology box-derived endothelin (ET) antagonist peptide (ETR-P1/fl) on the early hemodynamic changes in a hyperdynamic endotoxemic dog model. Mean arterial pressure (MAP), cardiac output (CO) and myocardial contractility (MC) were measured in closed-chest animals. Plasma levels of ET-1,2 were determined by radioimmunassay. A hyperdynamic circulatory response was elicited with a 2-hour infusion of 5.3 micrograms/kg of E. coli endotoxin (ETX). Control and ETX-treated animals received an infusion of ETR-P1/fl (0.1 mg/kg) i.v. ETX treatment decreased MAP and MC, increased initially CO, and a long lasting elevation in the plasma ET level was observed. In ETX-treated animals the administration of ETR-P1/fl significantly prolonged the increase in CO and inhibited the depression of MC. Our results suggest that treatment with the ET antagonist ETR-P1/fl may be advantageous in the early phase of endotoxemia.

Animals↗
PubMed1997

Endothelin-1-induced circulatory response in the rat: the role of ETA and ETB receptors.

Production of the powerful vasoconstrictor endothelin-1 (ET1) is increased in a number of pathological conditions. This study was performed 1. to assess the effects of a twofold elevation of circulating ET1 on global hemodynamics and cardiac function, and 2. to determine the ET receptor subtypes that are responsible for this action. We have used the ETA receptor-selective antagonist BQ 610, the novel ETA receptor antagonist ETR-Pl/fl peptide and the specific ETB receptor antagonist IRL 1038 to investigate the role of these receptor subtypes in mediating circulatory changes induced by ET1 in anesthetized Wistar rats. ET1 infusion produced a significant rise in mean arterial pressure (MAP), elevated total peripheral resistance (TPR), and decreased cardiac output (CO). BQ 610 and ETR-Pl/fl pretreatment significantly attenuated the ET1-induced hemodynamic changes. Pretreatment with IRL 1038 had no effect on CO, but significantly reduced MAP and TPR elevation 20 min after ET1 infusion. These results suggest that ET1 may contribute to circulatory failure in conditions with increased ET1 production via a mechanism involving ETA receptors. ETB receptors, albeit to a lesser extent than ETA receptors, are also involved in mediating ET1-induced peripheral vasoconstriction in the rat.

Animals↗
PubMed1997

[Two cases of cystic fibrosis in Japanese/German twins].

We report a case of twins with cystic fibrosis. The twins are of mixed parentage, having a Japanese mother and a German father. One case presented with meconium ileus as a neonate. The other twin was relatively healthy until the age of 6, when she was first hospitalized with a diagnosis of pulmonary aspergillosis. They have been receiving standard therapies in the United States, including digestive enzymes, vitamins, and periodic antibiotics. At the age of 19 both patients received home intravenous antibiotic therapy, and began to use an inhaled DNase at the age of 20. When the patients were 19 they were screened for the common mutations causing cystic fibrosis, and the delta F508 CFTR mutation was identified. We analyzed their CFTR genes, as well as those of their Japanese mother and grandmother. Missense mutations at exon 7 (R347H) and exon 16 were found (D979A) in the twins and in their Japanese mother.

Adult↗
PubMed1997

Design and in vitro activity of ribozymes against mRNA of a rat membrane inhibitor of complement.

Mammalian cells are usually protected from the complement-mediated injury by a number of complement regulatory proteins. A rat protein designated as 512 antigen is thought to be such a complement regulatory protein. A cDNA of 512 antigen has been cloned and analyzed. To investigate the function of 512 antigen, we plan to construct a ribozyme system against 512 antigen expression. We have designed two hammerhead ribozymes targeted to the 512 antigen mRNA and tested the ribozyme activities in vitro. Both hammerhead ribozymes efficiently cleaved the 512 antigen mRNA in vitro. We have also designed a hairpin ribozyme against this mRNA. The activity of the hairpin ribozyme will also be discussed.

Animals↗
PubMed1996

Molecular cloning of guinea pig membrane cofactor protein: preferential expression in testis.

Human membrane cofactor protein (MCP) is a widely distributed cell-associated complement-regulatory protein, and recent findings suggest that MCP may be involved in sperm-egg interaction. We have isolated four cDNA clones and one reverse transcriptase-PCR product homologous to human MCP from guinea pig testis. These clones defined five isoform classes generated from a single copy gene by alternative splicing. Reverse transcriptase-PCR revealed that two classes for the clones termed GMP1 and GM2 were predominant. GMP1 consisted of four short consensus repeats (SCRs), regions corresponding to the human serine/threonine/proline-rich C (STP(C)) domain and a human region of unknown significance, a hydrophobic region presumed to be a transmembrane domain, and a cytoplasmic region. Identity with human MCP in the SCR region was 56% at the amino acid level and 71% at the nucleotide level. GM2 had the same structure as GMP1, except that it lacked the fourth SCR, which is presumed to be essential for C3b binding of human MCP. Northern blotting analysis of various tissues revealed a significant level of MCP transcripts in testis. Guinea pig MCP is likely to have only one STP domain that is homologous to human STP(C) and is similar in this respect to human spermatozoa MCP. Gene analysis revealed a single base deletion and a lack of consensus sequences for splicing in the guinea pig regions corresponding to human STP(A) and STP(B), respectively. These results suggest that guinea pig MCP plays a more restricted role in reproduction than does human MCP.

Amino Acid Sequence↗
PubMed1996

Antisense homology boxes in C5a receptor and C5a anaphylatoxin: a new method for identification of potentially active peptides.

A computer program was designed to locate regions termed antisense homology boxes (AHB), i.e., 8-15 amino acid regions corresponding to complementary DNA strands. Two AHBs were found in C5a and eight within the C5a receptor. The majority of intermolecular AHBs were found to overlap those found in the intramolecular AHBs. Several AHB peptides were synthesized and tested for their ability to interfere with C5a receptor functions. A peptide fragment of the C5a receptor corresponding to the loop between the fifth and sixth hypothetical transmembrane regions (amino acids 226-245) antisense to C5a and an intramolecular AHB in C5a receptor proved to be an antagonist of C5a when preincubated with C5a at high concentrations (>0.5 microM). However, when U937 cells bearing the C5a receptor were preincubated with this peptide at a much lower concentration (even as little as 40 pmol), the AHB peptide behaved as an agonist. Another AHB peptide corresponding to region 10-27 in the C5a receptor bound to two of its corresponding antisense peptides derived from C5a anaphylatoxin, corresponding to amino acids 37-43 and 61-74. This observation raises the possibility that the C5a receptor may bind C5a with two distinct orientations. Two other AHB peptides derived from C5a, PL12 (amino acids 12-27), and PL61 (amino acids 61-74), were also shown to inhibit activity. Incubation of dibutyryl cyclic AMP-stimulated U937 cells with PL37 (amino acids 37-51) resulted in increased intracellular Ca2+ levels and an anergy to subsequent challenge with C5a. Locating regions with sense-antisense relationships in proteins might help in identification of peptides that can interfere with the function of target proteins.

Amino Acid Sequence↗
PubMed1996

Splenic B-cell activation in lipopolysaccharide-non-responsive C3H/HeJ mice by lipopolysaccharide of Porphyromonas gingivalis.

Porphyromonas gingivalis 381 lipopolysaccharide (LPS) definitely exhibited mitogenic activity in purified B-cells, separated from spleens of LPS-responsive C3H/HeN mice and LPS-non-responsive C3H/HeJ mice by using a magnetic cell sorting system. The mitogenic activity induced by P. gingivalis LPS was incompletely inhibited by polymyxin B. P. gingivalis LPS also induced a higher production of interleukin-6 (IL-6) in splenic B-cells of C3H/HeN mice as compared with Escherichia coli LPS. Furthermore, P. gingivalis LPS, but not E. coli LPS, induced definite IL-6 production in C3H/HeJ mice. P. gingivalis LPS increased tyrosine, serine/threonine phosphorylation of proteins with various major induced bands in splenic B-cells of both C3H/HeN and C3H/HeJ mice. Additionally, radioiodinated P. gingivalis LPS, similarly to E. coli LPS, bound to a 73-kDa protein on C3H/HeJ as well as C3H/HeN B-cells. Thus P. gingivalis LPS may activate B-cells of C3H/HeJ as well as C3H/HeN mice via the LPS-specific binding protein on the cells.

Acute-Phase Proteins↗
PubMed1996

Skin sympathetic nerve activity and event-related potentials during auditory oddball paradigms.

Skin sympathetic nerve activity (SSNA) from the tibial nerve and event-related brain potentials (ERPs) were recorded simultaneously during auditory oddball paradigms with a counting task in 10 healthy subjects to elucidate the relationships between the autonomic nervous system and the cognitive process. After the target tones. SSNA bursts were observed more frequently than after the non-target tones. Moreover, the amplitudes of SSNA bursts elicited after the target tones were higher than those elicited after the non-target tones. However, when subjects ignored the series of tones, there was no significant difference between the incidence of SSNA bursts after rare tones and frequent tones. The P300 latencies for the target trials with SSNA bursts were shorter than those for the target trials without SSNA bursts. The average ERP wave forms for the target trials with SSNA bursts showed larger positive deflection in the early part of the P300 component than those for the target trials without SSNA bursts. We conclude that SSNA is generated in relation to the conscious cognitive process, as well as to the reactive automatic process to changes in repeating stimuli. The early part of the P300 component, possibly P3a, may be related to the mechanisms that generate SSNA.

Adult↗
PubMed1996

Loss of cerebellar Purkinje cells in aged mice homozygous for a disrupted PrP gene.

Prion protein (PrP) is a glycoprotein constitutively expressed on the neuronal cell surface. A protease-resistant isoform of prion protein is implicated in the pathogenesis of a series of transmissible spongiform encephalopathies. We have developed a line of mice homozygous for a disrupted PrP gene in which the whole PrP-coding sequence is replaced by a drug-resistant gene. In keeping with previous results, we find that homozygous loss of the PrP gene has no deleterious effect on the development of these mice and renders them resistant to prion. The PrP-null mice grew normally after birth, but at about 70 weeks of age all began to show progressive symptoms of ataxia. Impaired motor coordination in these ataxic mice was evident in a rotorod test. Pathological examination revealed an extensive loss of Purkinje cells in the vast majority of cerebellar folia, suggesting that PrP plays a role in the long-term survival of Purkinje neurons.

Animals↗
PubMed1996

Suppression of CD44 expression decreases migration and invasion of human glioma cells.

We have reported high expression of CD44H in human glioma cells. To investigate the role of CD44H in the invasion of human glioma, we established a CD44-anti-sense-gene-expression glioma cell line named U-251A1. The expression of CD44H in the G-418-selected U-251A1 cells was reduced to 20% of that in the parental U-251SP cells, as determined by flow-cytometry analysis. We first examined the migratory responses of U-251A1 cells in vitro by time-lapse video-microscopic sparse cell-migration assay on hyaluronic acid or on chondroitin 6 sulfate. U-251A1 cells did not show significant differences in motility on any substrate, while U-251SP and other CD44H-positive cells showed dose-dependent increase of migration specifically on hyaluronic acid. To examine the physiologic function of CD44H in gliomas in vivo, U-251A1 and its control cells, U-251S1, which retain CD44-sense-expression vector, were injected stereotactically into the brains of nude mice. U-251A1 cells were localised in the region of the injection site, with relatively well demarcated borders between tumour and brain tissue, while the control cells demonstrated a cell-infiltration pattern. Our data suggest that CD44H may be required for infiltration of glioma cells through its interaction with hyaluronic acid, a major component of the brain extracellular matrix.

Animals↗
PubMed1996

Alteration of extracellular matrix in dilated cardiomyopathic hamster heart.

The purpose of this study was to characterize the collagen in hereditary dilated cardiomyopathic hamster hearts, and to examine the participation of the collagen in the occurrence and progression of cardiomyopathy. BIO 53.58 hamsters (5, 10, 20 weeks old) were used as the model of dilated cardiomyopathy. Flb hamsters were used as controls. The collagen content was almost constant at any age in the Flb hamsters, but increased with age in BIO 53.58 hamsters. Type III collagen increased significantly in BIO 53.58 hamsters at 10 weeks. The acetic acid solubility of collagen decreased in BIO 53.58 hamsters as the fibrosis progressed, but was unchanged in controls. Reducible crosslinks showed a tendency to decrease progressively in BIO 53.58 hamsters. There were no differences between Flb and BIO 53.58 hamsters at 5 weeks, but its expression in BIO 53.58 hamsters at 10 and 20 weeks of age increased compared to Flb controls. These findings indicate that in the early phase of cardiomyopathy the extracellular matrix of the myocardium is rich in type III collagen. In the later phase, the matrix resembles that of hard tissues, whose collagen is mainly of type I collagen and is insoluble. These data suggest that the increased collagen synthesis may impair the cardiac function in the development of cardiomyopathy.

Animals↗