Search PubMed⌕ Search

Biomedical subjects

K Kondo

Publications and source records attributed to K Kondo.

At least 433 records · Page 24Linked to original sources
PubMed1995

Stimulation of cyclic AMP formation by pituitary adenylate cyclase-activating polypeptide is attenuated by glutamate in rat brain slices.

In rat hippocampal slices, pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38) stimulated cyclic AMP formation in dose- and time-dependent manners. The PACAP-38 action was dose-dependently attenuated by L-glutamate in the hippocampus; L-glutamate at the concentration of 1 mM attenuated PACAP-38-stimulated cyclic AMP formation by approximately 30%. The inhibitory effect of L-glutamate is also observed in rat cerebellar slices. In contrast, the inhibitory effect of a prostanoid EP3-receptor agonist on PACAP-38-stimulated cyclic AMP formation was brain region-specific; the inhibitory action was observed in the cerebellum but not in the hippocampus.

Adenylyl Cyclases↗
PubMed1995

Micro-assay to measure the allergenicity of a Kunitz-type soybean trypsin inhibitor toward Balb/c mice by using RBL-2H3 cells.

The allergenicity of a Kunitz-type soybean trypsin inhibitor (KSTI) was investigated by a micro-assay of beta-N-acetylhexosaminidase released from RBL-2H3 cells primed with the anti-KSTI serum. KSTI stimulated the release of beta-N-acetylhexosaminidase from RBL-2H3 cells primed with the antiserum. The response of RBL-2H3 cells to the reaginic activity of the mouse anti-KSTI serum correlates fairly well with that by the passive cutaneous anaphylaxis (PCA) test, the sensitivity of both assays appearing to be similar. These results suggest that measuring the beta-N-acetylhexosaminidase released from RBL-2H3 is a convenient way for studying the allergen or the reaginic activity of a murine serum in place of the PCA test.

Allergens↗
PubMed1995

Flow cytometric analysis and immunohistochemistry of delayed-type hypersensitivity responses in mice immunized with rat hepatocytes.

Delayed-type hypersensitivity (DTH) responses to rat hepatocytes (HCs) in mice were investigated by flow cytometric analysis and immunohistochemistry with monoclonal antibodies directed against murine class II, CD4, and CD8 antigens. Mice were immunized subcutaneously (s.c.) with 10(6) rat HCs (referred to as s.c.-immunized mice), and control mice were injected s.c. with sterile Hanks' solution (non-immunized mice). Four days later, 10(5) rat HCs were injected into the footpad of s.c.-immunized mice and non-immunized mice. The DTH response in s.c.-immunized mice significantly increased after challenge when compared to that in non-immunized mice. The numbers of class II+, CD4+, and CD8+ cells in the footpad, and CD4+ and CD8+ cells in the inguinal lymph node of s.c.-immunized mice significantly increased during the DTH response. An increase in the number of CD4+ cells in the footpad of s.c.-immunized mice after challenge was more significant than that of non-immunized mice. The number of CD4+ cells increased more markedly in the footpad of s.c.-immunized mice as compared to that of CD8+ cells. Furthermore, immunohistochemical studies of the footpad of s.c.-immunized mice showed more severe infiltration of CD4+ cells rather than CD8+ cells at the injection site of rat HCs. These results suggest that the DTH response in the footpad of mice immunized with rat HCs is associated with severe infiltration of CD4+ cells.

Animals↗
PubMed1995

Effects of atrioventricular intervals on right atrial monophasic action potential duration during pacing or reciprocating tachycardia.

We evaluated the relationship between changes in the atrioventricular (AV) intervals and right atrial monophasic action potential duration at 90% repolarization (RA-MAPD90) in humans. In 4 patients, RA-MAPD90 was measured during AV reciprocating tachycardia (AVRT, n = 2) or AV node reentrant tachycardia (AVNRT, n = 2) and atrial or ventricular pacing at similar cycle lengths. In 10 patients, RA-MAPD90 was measured during continuous atrioventricular sequential pacing at AV intervals of 0, 50, 100, 150, 200, 250, 300, 350 msec for 90 sec at a cycle length of 333-400 msec. In patients with AVRT, the RA-MAPD90 during tachycardia was shorter than RA-MAPD90 during RA or RV pacing. In patients with AVNRT, RA-MAPD90 during tachycardia was similar or longer than RA-MAPD90 during RA or RV pacing. As the AV interval was increased from 0 msec to 150 msec, the peak right atrial pressure decreased from 8-12 mmHg to 2-3 mmHg. RA-MAPD90 decreased to its minimal value at an AV interval of 150 msec. The maximal difference in the RA-MAPD90 obtained by changing the AV interval was 22.5 +/- 3.0 msec. We conclude that 1) a very short AV or VA interval causes an increase in RA-MAPD90 which correlates with an increase in RA pressure, and 2) RA-MAPD90 during supraventricular tachycardia is different from RA-MAPD90 during atrial or ventricular pacing. Thus, a contraction-excitation feedback mechanism may exist in the human atrium.

Action Potentials↗
PubMed1995

[Molecular genetic analysis of a family with von Hippel-Lindau disease].

We analyzed germline mutations of the von Hippel-Lindau (VHL) gene located at chromosome 3p25 in a family of VHL disease by using single strand conformational polymorphism (SSCP) and Southern blot analyses. In 10 individuals including 2 patients with multiple renal cell carcinomas, multiple pancreatic cysts and cerebellar hemangioblastoma, there are no positive results in SSCP analysis. However, in 2 patients and one kindred, same abnormal band was observed in Southern blot analysis. Moreover, in this one kindred of 17 years old girl, multiple pancreatic cysts were found by computerized tomography (CT). These results shows the alteration in the VHL gene is a major rearrangement but not a small mutation and this alteration caused VHL disease in this family. Furthermore, presymptomatic diagnosis by direct mutation analysis seems to be very useful for early detection of this disease.

Adolescent↗
PubMed1995

[Results of mutation analyses of von Hippel-Lindau disease gene in Japanese patients: comparison with results in United States and United Kingdom].

Recently the gene responsible for the von Hippel-Lindau (VHL) disease was identified as a tumor suppressor gene. Our ongoing studies on the mutation of the VHL gene in Japanese 28 VHL families with single strand conformational analyses of DNA and Southern blot analyses revealed 6 cases of insertion or deletion, 1 cases of splice site mutation and 9 cases of missense mutation, and 3 possible intragenic deletions. Our analytical findings are essentially similar to those observed in the western countries. The VHL families associated with pheochromocytoma had the same mutational hot spot as those in the western countries. Molecular analyses of the VHL gene in the Japanese VHL disease substantially improved the understanding of this disease and its inheritance character.

Blotting, Southern↗
PubMed1995

[A synchronous double cancer of esophagus and stomach treated with 5-fluorouracil and consecutive low-dose cisplatin].

We report a case of double cancer of esophagus and stomach treated with 5-fluorouracil and consecutive low-dose cisplatin. The patient was a 58-year-old man with liver cirrhosis. Using upper gastrointestinal fiberscopy, a superficial depressed lesion (O-IIc) in the middle thoracic part of the esophagus and Borrmann 2 type lesion in the fundus of the stomach were also detected. Microscopic examination of the biopsy specimen revealed moderately differentiated squamous cell carcinoma and adenocarcinoma. But laparotomy could not be done due to impaired liver function (KICG 0.051, ICGR15 45.2%). The patient was treated for 28 days with continuous 24 hour infusion 5-FU, 250 mg/body/day plus low dose CD-DP, 10 mg/body daily by bolus infusion d1-5, 8-12, 15-19, 22-26. One month after the chemotherapy, both the gastric cancer and the esophageal cancer were remarkably reduced (diagnosis: PR), and showed no malignancy in the histology. There was no change in the histological findings of the esophageal lesion at 31 months after the chemotherapy. This therapy is effective for patients with gastric cancer and esophageal cancer.

Adenocarcinoma↗
PubMed1995

Retinoblastoma gene mutation in primary human renal cell carcinoma.

We searched for possible mutations in the E2F-binding region of retinoblastoma gene in primary human renal cell carcinomas, using polymerase chain reaction and single-strand conformational polymorphism analysis of RNA. Retinoblastoma gene mutation was detected in 1 of 21 cases (5%). DNA sequencing of the polymerase chain reaction product verified that this case had a 6-base deletion at the beginning of exon 8. Our findings suggest that mutation of the retinoblastoma gene is involved in only a subgroup of sporadic human renal cell carcinomas.

Base Sequence↗
PubMed1995

[Coronary artery-to-pulmonary artery fistula with aneurysm: two cases report].

We performed the operation for coronary artery-to-pulmonary artery fistula with aneurysm in two patients. The coronary angiograms of one patient, who was a 63-year-old female, revealed coronary artery-to-pulmonary artery fistula originated from the left coronary artery with 3 aneurysms of 2 cm in diameter, respectively. The angiogram of another patient, who was a 77-year-old female, revealed coronary artery-to-pulmonary artery fistula originated from both coronary arteries with the giant aneurysm of 7 cm in diameter. We decided to operate by the reason of possibility of rupture of the aneurysms, and performed resection of the fistulas and the aneurysms with the closure of the drainage openings into the pulmonary artery with the aid of cardiopulmonary bypass. It was recommended to resect the coronary aneurysm before growing big in the patient with the coronary artery-to-pulmonary artery fistula.

Aged↗
PubMed1995

Automated homogeneous liposome-based assay system for total complement activity.

We developed an automated homogeneous immunoassay, based on immune lysis of dinitrophenyl (DNP)-labeled liposomes, for measuring total complement activity. Liposome lysis caused by complement activity was detected spectrophotometrically from entrapped glucose-6-phosphate dehydrogenase activity. Complement activity in human sera was quantified by comparison with a calibration curve. For ease of application to fully automated routine clinical analyzers, we adopted a two-reagent system, one reagent containing a homogeneous population of small DNP-labeled liposomes and one containing antibody/substrate. This system required calibration only once a week. Within-run and between-run CVs were 0.4-1.3% (n = 10) and 1.8-4.7% (n = 10), respectively. Serum results were linear upon dilution (with saline) over a twofold range. Bilirubin, hemoglobin, Intrafat, and serum proteins such as rheumatoid factor, M protein, IgG, and IgA did not affect the assay results. The results (y) correlated well with those from a hemolytic complement activity test (x): y = 1.05x - 1.14, r = 0.92, on 66 samples in the range < 10- > 50 kU/L. This method should therefore be of great use for the determination of complement activity.

Adolescent↗
PubMed1995

Synchronous circadian rhythms of mRNA levels and activities of cholesterol 7 alpha-hydroxylase in the rabbit and rat.

Cholesterol 7 alpha-hydroxylase, the key enzyme in a series of metabolic changes for the production of bile acids from cholesterol, shows circadian rhythms. The mechanism of the circadian rhythms is the subject of controversy; moreover, few pieces of information are presently available. Because the rabbit is a good animal model for the study of human cholesterol-bile acid metabolism, in the present study we isolated a complete cDNA encoding rabbit cholesterol 7 alpha-hydroxylase (3022 base pairs (bp) long and 1503 bp open-reading frame encoding 501 amino acid residues). Using this isolate rabbit cDNA and the rat cDNA as probes, the circadian rhythms of this enzyme were studied in normal male rabbits and rats. The animals were maintained on a 12-h light-dark cycle. Three subjects each were then killed every 3 h for 1 day. The livers were harvested, and the mRNA levels and the activities of the enzyme were measured. Both mRNA levels and activities of the enzyme showed remarkable circadian rhythms, with higher values during the dark phase and lower values reaching minimum during the light phase. The enzyme activities correlated well with the mRNA levels. There was no shift in the cycles of the enzyme activities and the mRNA levels. These findings suggest that pretranslational regulation is the most likely mechanism for the circadian rhythms of cholesterol 7 alpha-hydroxylase. Because the rhythms of mRNA levels and activities of this enzyme are synchronous, the turnover of the enzyme should be as fast as that of the mRNA, and we can hereafter measure the mRNA levels instead of the enzyme.

Amino Acid Sequence↗
PubMed1995

Early gastric carcinoma after gastrojejunostomy: clinical and pathological aspects.

Two rare cases of early gastric carcinoma that followed gastrojejunostomy without gastrectomy are reported. The time intervals between the initial gastrojejunostomy and resection of the distal stomach with the formation of a gastrojejunal stoma were 30 yr and 33 yr, respectively. The Japanese classification confirmed both lesions as type IIc type mucosal early gastric cancer. In these two cases, with coexisting gastric ulcers, atrophic gastritis and diffuse intestinal metaplasia were observed in the lesions of the carcinomas. The potential correlation between the exposure of tissue to duodenal juice and the subsequent development of a gastric carcinoma is discussed. Literature regarding gastric carcinoma after gastrojejunostomy is reviewed.

Carcinoma↗
PubMed1995

Cytomegalovirus latency and latency-specific transcription in hematopoietic progenitors.

Latency-associated transcripts have been detected in human cytomegalovirus (CMV)-infected granulocyte-macrophage progenitors and have been shown to be encoded from both DNA strands in the ie1/ie2 region of the viral genome. One class includes differentially spliced transcripts that extends exon 1 by initiating at two novel start sites 292 and 356 nucleotides in the ie1/ie2 promoter/enhancer region, upstream of the start site used during productive infection. The other class includes an unspliced transcript antisense to ie1 exons 2,3, and 4. These transcripts are specific to latently infected cells and are not detected during productive infection of human fibroblast cells. Several open reading frames are found within these cytomegalovirus latency-specific transcripts (CLTs), including one 94 codons long that begins in the extended exon 1 region and is predicted to remain open through the exon1/2 and exon 2/3 splice junctions. Expression of latent transcripts was detected in bone marrow-derived hematopoietic samples from CMV-seropositive healthy donors but not from seronegative donors.

Base Sequence↗
PubMed1995

Infrequent somatic mutations of the p16 and p15 genes in human bladder cancer: p16 mutations occur only in low-grade and superficial bladder cancers.

A recently identified gene, p16, located on chromosome 9p21, has been shown to be deleted and/or mutated in various types of human cancers. To investigate structural alterations of p16 and a neighboring gene, p15, we examined human bladder cancers for mutations in the entire coding region of these genes using polymerase chain reaction and single-strand conformational polymorphism analysis. Of 50 samples obtained from patients with bladder cancer, 3 (6%), all low-grade and superficial tumors, were found to have p16 gene alterations. The alterations included 1 missense mutation and 2 single-base deletions. We found no p15 gene mutations in these 50 bladder cancers. Our results suggested that p16 gene mutations, although they occurred at low frequency, are involved in some low-grade and early stage bladder cancers.

Base Sequence↗
PubMed1994

Human cytomegalovirus latent infection of granulocyte-macrophage progenitors.

We have investigated the interaction of human cytomegalovirus (CMV) with cultured primary granulocyte-macrophage progenitors, a suspected natural site of viral latency, and have established conditions for latent infection and reactivation in this cell population. Progenitor cells from human fetal liver or bone marrow maintained a CD14+, CD15+, CD33+ cell surface phenotype during propagation in suspension culture. Exposure to human CMV did not reduce growth or alter the phenotype of these cells during a 4-week culture period. Viral replication was not detectable in these cells, although viral DNA, as measured by PCR analysis, persisted in a high proportion of cultured cells in the absence of delayed early (beta) gene expression. Viral gene expression was restricted such that only ie1 region transcripts were detected by PCR analysis of cDNA, and these transcripts were estimated to be present in no less than 2-5% of latently infected cells. Most of these transcripts remained unspliced, a result that strikingly contrasts with the splicing pattern normally seen during viral replication in permissive cells. Latent virus reactivated after prolonged, 16- to 21-day cocultivation of infected granulocyte-macrophage progenitors with permissive cells, results that support a role for the myelomonocytic cell population as a biological reservoir of latent human CMV and suggest that these cells may be the source of CMV DNA PCR-positive monocytes found in the peripheral blood of healthy carriers.

Antigens, CD↗