Biomedical subjects

J Hashimoto

Publications and source records attributed to J Hashimoto.

At least 19 recordsLinked to original sources

PubMed1992

Analysis of carrot genes for proliferating cell nuclear antigen homologs with the aid of the polymerase chain reaction.

We designed a polymerase chain reaction-based strategy to obtain information about the origin and distribution of a newly discovered proliferating cell nuclear antigen (PCNA) homolog. Carrot genomic segments were amplified using degenerate primers for two conserved regions of known PCNA homologs. The genes encoding the larger PCNA as well as typical PCNA contained introns. Thus, unlike processed PCNA pseudogenes in mammals, the larger homolog is not generated through reverse transcription of a typical PCNA mRNA. Moreover, introns of the larger PCNA homolog were positioned at the characteristic sites in plant PCNA genes. Attempts to amplify cDNA for an additional PCNA homolog from mammalian cells have been unsuccessful. These results suggest that the larger PCNA homolog was generated, presumably through gene duplication, after the divergence of the Planta and Animalia.

Amino Acid Sequence↗

PubMed1992

Identification of carrot cDNA clones encoding a second putative proliferating cell-nuclear antigen, DNA polymerase delta auxiliary protein.

The proliferating cell-nuclear antigen (PCNA) plays a key role in the control of eukaryotic DNA replication. We have isolated two cross-hybridizing groups of cDNA encoding carrot homologs of PCNA. Sequence analysis and Southern-blot experiments showed that the cDNA were derived from two distinct genes. One corresponded to the typical PCNA, which is known to be highly conserved in eukaryotes from yeast to man; its mRNA is 1.2 kb in size and the calculated molecular mass of the protein is 29 kDa. The other encoded a larger PCNA homolog which has not previously been reported; the mRNA is 1.5 kb in size, the N-terminal three quarters (calculated molecular mass, 29 kDa) of the protein product is 88% identical at the amino acid level to the typical PCNA, but the protein has an extra C-terminal domain of 11 kDa. Both PCNA homologs were apparently coexpressed concomitant with somatic embryogenesis. The mRNA level of the novel homolog is 10-20% that of the typical PCNA in the embryos. The presence of the second putative PCNA may provide new insight into studies on the mechanism of DNA replication in eukaryotes.

Amino Acid Sequence↗

PubMed1992

Immunohistochemical, autoradiographic and electron microscopic studies on the transformation of fibroblasts into chondrocytes in the mouse subfascia induced by bone morphogenetic protein.

Functional morphology on the transformation of fibroblasts into chondrocytes induced by bone morphogenetic protein (BMP) was studied by light and electron microscopy using 35S autoradiography and immunohistochemistry for S-100 protein and type-II collagen. A pellet containing BMP obtained from a murine osteosarcoma was transplanted into the mouse subfascia. By 3 days after implantation, many typical fibroblasts, which were free of the silver grains for 35S and devoid of both S-100 protein and type-II collagen, entered the pellet region. By 5 days, the fibroblasts in the pellet region became polygonal in shape, and cytoplasmic vesicles and vacuoles appeared, both containing a homogeneous substance of low electron density. At 5 days, autoradiography revealed many silver grains for 35S over the Golgi apparatus and vesicles and vacuoles of the cells in the pellet region as well as over the surrounding extracellular matrix. Moreover, the cells at 5 days displayed immunoreactivity to both proteins. The extracellular matrix around the cell began to show clear metachromasia and increased in amount with time. At 9 days all the cells in the pellet region were round or oval in shape and surrounded by an abundant cartilaginous matrix. The rough endoplasmic reticulum and Golgi apparatus were extremely well developed, and a large number of vacuoles and vesicles were seen in the cytoplasm. These cells showed intense immunoreactivity to both proteins, and strong accumulation of sulfur was visualized in the extracellular matrix by autoradiography. These results suggest that the fibroblasts in the pellet region change into chondroblasts by 5 days, and become typical chondrocytes by 9 days.

Animals↗

PubMed1992

Isolation and characterization of cDNA clones encoding cdc2 homologues from Oryza sativa: a functional homologue and cognate variants.

Using probes obtained by PCR amplification, we have isolated two cognate rice cDNAs (cdc2Os-1 and cdc2Os-2) encoding structural homologues of the cdc2+/CDC28 (cdc2) protein kinase from a cDNA library prepared from cultured rice cells. Comparison of the deduced amino acid sequences of cdc2Os-1 and cdc2Os-2 showed that they are 83% identical. They are 62% identical to CDC28 of Saccharomyces cerevisiae and much more similar to the yeast and mammalian p34cdc2 kinases than to rice R2, a cdc2-related kinase isolated previously by screening the same rice cDNA library with a different oligonucleotide probe. Southern blot analysis indicated that the three rice clones (cdc2Os-1, cdc2Os-2 and R2) are derived from distinct genes and are each found in a single copy per rice haploid genome. RNA blot analysis revealed that these genes are expressed in proliferating rice cells and in young rice seedlings. cdc2Os-1 could complement a temperature-sensitive yeast mutant of cdc28. However, despite the similarity in structure, both cdc2Os-2 and R2 were unable to complement the same mutant. Thus, the present results demonstrate the presence of structurally related, but functionally distinct cognates of the cdc2 cell cycle kinase in rice.

Amino Acid Sequence↗

PubMed1992

Neuron-specific enolase reduction in irradiated salivary glands of the rat--an immunohistochemical study.

Neuron-specific enolase (NSE) in the salivary glands of normal and irradiated rats was studied by immunohistochemical methods. The normal salivary gland of Sprague-Dawley rats (465 g) showed positive staining for NSE in striated ducts and granular convoluted tubule (GCT) cells. A single radiation, TDF (time, dose, fractionation factor) 100 and 200 (18.82 Gy and 27.97 Gy, respectively) was done, and 4 groups (1, 2, 3 and 4 weeks after radiation) of 5 rats each were used. Irradiated salivary glands indicated a remarkable reduction of NSE staining in GCT cells and a reduction but to a lesser degree in the striated duct of the submandibular gland. Immunohistochemical deposition of NSE was not changed in the sublingual glands of irradiated rats. The reduction of NSE immunodeposition was irradiation dose dependent.

Animals↗

PubMed1992

The accuracy and performance of the A&D TM 2421, a new ambulatory blood pressure monitoring device based on the cuff-oscillometric method and the Korotkoff sound technique.

The accuracy and performance of the A&D TM 2421, a new ambulatory blood pressure (BP) monitoring device using both the cuff-oscillometric method (O) and the Korotkoff sound method (K) were evaluated. The device was tested for accuracy under static and dynamic conditions by simultaneous comparison with two observers using a standard mercury column sphygmomanometer (standard method) and by the objective recording method (ORM). The performance of the device was also evaluated under ordinary ambulatory conditions. The mean differences in BP of standard method from K-method were -1.2 +/- 4.7 mm Hg systole and 1.3 +/- 4.7 mm Hg diastole (n = 323, mean +/- SD) and those of standard method from O-method were -0.4 +/- 5.3 mm Hg systole and 1.4 +/- 5.1 mm Hg diastole (n = 323). The agreement between each of the two methods of the device and the standard method was within 10 mm Hg for more than 90% of both systolic and diastolic readings. During bicycle exercise, the mean differences in BP of standard method from K-method were -3.4 +/- 4.8 mm Hg systole and 1.8 +/- 5.2 mm Hg diastole (n = 71) and those of standard method from O-method were -1.1 +/- 7.3 mm Hg systole and 1.7 +/- 7.8 mm Hg diastole (n = 67). There was a greater scatter in the individual comparisons of the device and the standard method during exercise, especially in diastolic BP. The relation between the device and ORM was almost similar to that between the device and the standard method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Immunoreaction of keratin, actin, S-100 protein and rat-EGF in duct-ligated rat salivary glands.

Duct-ligated submandibular and sublingual glands of rats were evaluated immunohistochemically for changes in keratin (MoAb 1164), actin, S-100 protein and rat-EGF (rEGF). Normal salivary glands were reactive for keratin, S-100 protein and rEGF in the granular convoluted tubule (GCT) and duct cells, and for actin in the myoepithelium. Submandibular glands showed a marked reduction of S-100 protein and rEGF staining following duct ligation, and no increased staining of proliferating epithelial cells of the late stage in duct ligated glands. Sublingual glands revealed no marked changes for actin staining in myoepithelial cells, irrespective of atrophic changes occurring in acinar and duct cells after duct ligation. Immunohistochemical patterns differed for each type of gland; changes associated with the obstructive lesion were more prominent in the submandibular gland.

Actins↗

PubMed1992

The influence of antihypertensive agents on circadian rhythms of blood pressure and heart rate in patients with essential hypertension.

The effects of once-daily administration of calcium (Ca) channel blockers, beta-blockers and and angiotensin-converting enzyme (ACE) inhibitors on circadian rhythms of blood pressure (BP) and heart rate (HR) were studied using the cosinor method. Sixty-two recruited patients with essential hypertension (WHO stage I or II) were divided into three groups based on the class of administered drugs. In the Ca channel blocker group (n = 37, age 54 +/- 9.0 years), 18 patients were given YM 730 at a mean dose of 11 +/- 4.0 mg/day (mean +/- S.D.), 8 were given nitrendipine (11 +/- 6.7 mg/day), and 11 were given nisoldipine (8 +/- 6.4 mg/day). In the beta-blocker group (n = 15, age 42 +/- 13.5 years), 13 patients were given atenolol (44 +/- 11.0 mg/day), 1 was given nadolol (30 mg/day), and 1 was given sustained-release propranolol (60 mg/day). In the ACE inhibitor group (n = 10, age 56 +/- 8.7 years), 7 patients were given enalapril (6 +/- 2.8 mg/day), and 3 were given lisinopril (20 mg/day). Ambulatory BP monitoring (ABPM) was performed before and during treatment. Mean arterial pressure (MAP) and HR were monitored under ambulatory conditions every five minutes for 24 hr with a finger volume oscillometric device. In all three groups, the mesor of MAP decreased significantly, while the amplitude and acrophase did not change during treatment. beta-Blockers reduced the amplitude as well as the mesor of HR. Ca channel blockers increased the amplitude of HR without influencing the mesor. ACE inhibitors had no effect on the circadian rhythm parameters of HR. These results suggest that Ca channel blockers, beta-blockers and ACE inhibitors lowered BP throughout the day without changing the circadian BP rhythm. However, the three drug classes may have different influences on the autonomic nervous system that regulates circadian cardiac rhythm.

Adrenergic beta-Antagonists↗

PubMed1992

Circadian blood pressure variation in patients with renovascular hypertension or primary aldosteronism.

Circadian blood pressure (BP) variation were studied in patients with renovascular hypertension (RVH) and primary aldosteronism (PA). Ambulatory BP (ABP) was monitored every 5 min for 24 hrs in a ward setting in 23 patients with PA and 17 patients with RVH (13 patients with unilateral renal arterial stenosis and 4 with bilateral stenosis). In patients with RVH, ABP was monitored before and after treatment with a converting enzyme inhibitor or percutaneous transluminal angioplasty. Plasma renin activity (PRA) was high before percutaneous transluminal angioplasty in almost all patients with RVH and low in those with PA. Ordinary circadian BP variation, i.e. nocturnal fall and diurnal rise in BP, was confirmed in the patients with unilateral or bilateral renal artery stenosis. Percutaneous transluminal angioplasty successfully normalized both BP and PRA in those with RVH. Normal circadian BP variation was observed in those with RVH before the treatment with a converting enzyme inhibitor or percutaneous transluminal angioplasty as well as during treatment with the former and after treatment with the latter. Circadian BP variation in the patients with RVH was affected by the pathogenesis of renal artery stenosis alone, i.e, fibromuscular hyperplasia and atherosclerosis; with fibromuscular hyperplasia normal circadian BP variation was observed, while with atherosclerosis, nocturnal BP fall was restricted or eliminated. Circadian BP variation in those with PA before and after excision of adrenal adenoma was essentially similar to that in normal subjects and essential hypertensive patients. From these it seems that in patients with RVH or PA, circadian BP variation is not affected by hypertension per se or by pathogenesis of hypertension.

Adenoma↗

PubMed1992

Effect of slow release nifedipine tablets in patients with essential hypertension.

The antihypertensive effect of slow release nifedipine (CAS 21829-25-4) tablets (20 mg, Adalat) administered once or twice daily was studied in patients with essential hypertension of WHO stage I or II. Ambulatory blood pressure was monitored by a finger volume oscillometric device every 5 min for 24 h before and during the treatment with nifedipine. Whether administered once or twice daily, nifedipine tablets dit not change the pattern of circadian blood pressure variation; i.e. diurnal rise and nocturnal fall. Twice daily administration induced a significant downward shift in the blood pressure pattern. In other words, further hypotensive effect was observed during the night when the blood pressure was already low. On the other hand, administration once daily in the morning lowered daytime blood pressure without affecting blood pressure during the night. The duration of action of nifedipine tablets administered once daily was 12 h or more. In the acute experiment using 20 mg tablets of nifedipine, plasma concentration of nifedipine was well correlated with the percentage change in mean blood pressure. The minimal effective plasma concentration of nifedipine was estimated to be 13.4 ng/ml. However, in chronic treatment, nifedipine lowered blood pressure at the plasma concentration of 10 ng/ml. The results indicate that nifedipine tablets administered once daily provide an effective antihypertensive regimen for controlling daytime hypertension with minimal antihypertensive effect during the night.

Adult↗

PubMed1992

[Study of postgastrectomy fatty liver].

Fatty liver was often found concomitantly by the ultrasound during the follow up study of the gastric cancer operation. By ultrasound, development of postgastrectomy fatty liver was seen in 29 out of 176 patients (16.5%) with several gastrectomies. The number of the patients with postgastrectomy fatty liver was 12 out of 104 patients (11.5%) with distal partial gastrectomy with B-I reconstruction, while that was 17 of 72 patients (23.6%) with total gastrectomy with several reconstructions. The incidence of postoperative fatty liver change was significantly higher in the patients under 59 years old compared to the elders. Seventy-five g oral glucose test induced oxyhyperglycemia and hyperinsulinemia in patients with gastrectomy, especially with total gastrectomy. Integrated plasma insulin and triglyceride responses during first one hour in postgastrectomy patients were significantly higher than preoperative values. Moreover, plasma insulin and blood sugar in response to oral glucose test were significantly higher in patients with postgastrectomy fatty liver, compared to those in patients without fatty liver. These results suggested that the postgastrectomy fatty liver was resulted from the abnormality of the glucose metabolism.

Age Factors↗

PubMed1992

Immunoreactivity of calmodulin, S-100 protein alpha and beta subunits in rat submandibular glands.

The calcium-binding proteins calmodulin and S-100 protein alpha and beta subunits were studied in Rat submandibular salivary gland using monoclonal antibodies and immunoperoxidase staining. Histologically, Rat submandibular gland consists of acinar and ductal components. The latter include intercalated, granular convoluted tubule, striated and excretory ducts. Ultrastructural studies of adult Rat granular convoluted tubule show granular cells, pillar cells and transition cells. Immunostaining for S-100 alpha and calmodulin was observed in granular convoluted tubule pillar cells and transition cells, whereas cells of striated ducts and intercalated ducts stained positive for calmodulin. S-100 beta staining in acinar cells was visible as a fine granular pattern. Although immunohistochemical localization in rat submandibular gland differed for S-100 alpha and beta subunits, expression was similar for S-100 alpha and calmodulin in the granular convoluted tubule segment. No immunodeposition of calmodulin, S-100 alpha or S-100 beta was found in granular cells, which contain growth factors such as EGF and NGF.

Animals↗

PubMed1992

[Phase I clinical trial of a new myocardial imaging agent, 99mTc-PPN1011].

A new myocardial imaging agent, 99mTc-1,2-bis[bis(2-ethoxyethyl) phosphino]ethane (99mTc-PPN1011) was administered to healthy male volunteers to evaluate its safety and kinetics. No significant drug-related events were observed. After intravenous injection, blood clearance was rapid. Prompt heart uptake (1.8% of the injected dose after 5 minutes) was followed by relatively slow wash-out (1.0% remained after 3 hours). Liver and lung uptake was observed but the clearance was more rapid than in the heart. 4.7-24.0% of the injected 99mTc-PPN1011 was excreted into urine until 4 hours after injection. 99mTc-PPN1011 also seemed to be excreted through hepato-biliary system. Excellent and low-background myocardial images were obtained using either SPECT or planar imaging. We conclude that 99mTc-PPN1011 could be useful for myocardial perfusion imaging.

Adult↗

PubMed1992

[Thallium-201 and gallium-67 scintigraphies in the diagnosis of pneumoconiosis combined with lung cancer].

Thallium-201 (201Tl) and Gallium-67 (67Ga) scintigraphies were performed on 62-year-old male with silicosis combined with lung cancer (squamous cell carcinoma). In 67Ga and early 201Tl images, radiotracer uptakes were observed in both sites of cancer and silicosis, and thus, it was impossible to differentiate cancer mass from the large opacity of pneumoconiosis. On the other hand, in the 201Tl delayed images, 201Tl was localized only in cancer mass, while it was washed out from the large opacity. Our findings indicated that 201Tl early and delayed scintigraphy findings were very useful to differentiate lung cancer from silicosis.

Carcinoma, Squamous Cell↗

PubMed1992

Evaluation of polylactic acid homopolymers as carriers for bone morphogenetic protein.

Polylactic acid (PLA) homopolymers with molecular weights of 105,000; 21,000; 3300; 650; and 160d (PLA105000, PLA21000, PLA3300, PLA650, and PLA160, respectively) were prepared and evaluated as carriers for bone morphogenetic protein (BMP). Composites consisting of 4 mg of water-soluble, semipurified BMP and 100 mg of one of the PLA homopolymers were implanted into the dorsal muscles of mice. PLA105000/BMP, PLA21000/BMP, PLA3300/BMP, and PLA160/BMP composites failed to induce new bone formation; PLA105000, PLA21000, and PLA3300 elicited foreign-body reactions or chronic inflammation (or both), and PLA160 produced tissue necrosis. PLA650/BMP composites induced cartilage formation within one week and induced bone with hematopoietic marrow at three weeks postimplantation. PLA650/BMP composites were completely absorbed and replaced by new bone. The results suggest that within this group of PLA homopolymers, PLA650 may be the only type suitable for use as a BMP carrier.

Animals↗

PubMed1991

Highly conserved structure of proliferating cell nuclear antigen (DNA polymerase delta auxiliary protein) gene in plants.

In a previous paper [Suzuka, I., Daidoji, H., Matsuoka, M., Kadowaki, K., Takasaki, Y., Nakane, P. K. & Moriuchi, T. (1989) Proc. Natl Acad. Sci. USA 86, 3189-3193], we demonstrated the presence of a rice genomic-DNA fragment which hybridized with a rat proliferating-cell nuclear antigen (PCNA) cDNA probe, and proposed that plants possess the homolog of the PCNA gene which plays an essential role in DNA replication in mammals. Here we show that the sequence of the rice PCNA gene supports this proposal. The rice gene consists of four exons. The 5'-flanking region contains a variety of sequences similar to several consensus sequences believed to be important for the regulation of gene expression in eukaryotes. Determination of the transcription-start site and the structure of the 3'-flanking region of the gene indicated that the coded mRNA is 1073 bases. The rice PCNA genomic and cDNA clones are composed of 789 nucleotides; they encode a putative protein of 263 amino acids having a molecular mass of 29275 Da. Comparison of the coding regions of rice PCNA and rat PCNA revealed about 64% similarity at the nucleotide level and about 62% similarity at the amino acid level. Furthermore, comparison of the predicted amino acid sequence of the soybean PCNA with the rice PCNA sequence indicated a high degree of similarity (88%). The structural similarity between PCNA from plants and animals, despite the distant evolutionary relationship, indicates a strong selection pressure for conservation of this structure and suggests the presence of conserved DNA-replication mechanisms throughout the eukaryotes.

Amino Acid Sequence↗

PubMed1991

Production of interleukin-1 beta-like factor with synovial cell growth promoting activity from adult T-cell leukemia cells.

We observed a case of adult T-cell leukemia (ATL) with proliferative synovitis. Culture supernatants from ATL cells (ATL-SN) obtained from the peripheral blood constitutively produced an interleukin-1 (IL-1)-like factor in vitro, as shown by the growth inhibition factor (GIF) assay using the A375 melanoma cell line and the lymphocyte activating factor (LAF) assay using C3H/HeJ thymocytes. Neutralization studies indicated that polyclonal antibodies against IL-1 beta blocked most (80%) of the activity in ATL-SN. In addition, increased amounts of IL-1 beta mRNA were found in the ATL cells by dot blot analysis. Sephacryl S-200 chromatography showed that the molecular weight of this factor was approximately 17.5 kDa, and Western blot analysis revealed that this factor reacted with polyclonal anti-IL-1 beta antibody under the reduced condition. The isoelectric point was 7.5. Furthermore, ATL-SN showed significant activity in promoting the growth of synovial cells in parallel with IL-1 activity. These data suggest that the constitutive production of this IL-1 beta-like factor might be responsible for proliferative synovitis in this case.

Aged↗

PubMed1991

Preservation of ectopically induced bone in the mouse by estradiol.

The effects of estrogen on bone formation and bone resorption were examined in an experimental model of ectopic bone induction. In this experimental model, ectopic ossicles of uniform size were elicited reproducibly in three weeks by implanting pellets containing murine osteosarcoma derived bone morphogenetic protein (BMP), into the muscles of mice. Thereafter the induced ossicles showed a gradual reduction in bone mass due to negative bone balance. To estimate the effects of estrogen on bone formation and bone resorption, beta-estradiol-3-benzoate was administered exogenously to host mice from day 21 to day 41 (0.45 micrograms/g body weight, on alternate days, 10 treatments). Radiologic and histologic analysis confirmed the positive effect of estradiol on preserving bone mass over this period. Quantitative analysis showed an increase in the Ca content in ossicles after 21 days of estradiol treatment (139.1% of the baseline value on day 21). In the control group, the bone mass was reduced (47.4% of that on day 21). Bone resorption was determined by the reduction in 45Ca radioactivity from ossicles prelabeled with this radioisotope before estradiol administration. The rate of loss of the prelabeled 45Ca radioactivity was suppressed by estradiol (68.8% of prelabeled value in estradiol treated group and 87.7% in control group). The effect of exogenous estrogen on the bone forming phase of bone turnover in the ossicles was quantified by incorporation of 45Ca and 3H-proline. These bone formation parameters were increased to 2.2 and 1.9 times higher than those of the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗