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Biomedical subjects

H Kaji

Publications and source records attributed to H Kaji.

At least 19 recordsLinked to original sources
PubMed1992

The activation of cAMP-dependent protein kinase is directly linked to the stimulation of bone resorption by parathyroid hormone.

The present study was performed to characterize the direct involvement of cAMP in the stimulation of bone resorption by parathyroid hormone (PTH), using Sp-cAMPS and Rp-cAMPS, which were the direct agonist and antagonist in the activation of cAMP-dependent protein kinase (PKA), respectively. Bone resorbing activity was estimated as the number of pits formed on the dentine slice and total area of pits per slice in bone marrow cells derived from 2 week-old mice. Dibutyryl cAMP (dbcAMP)(10(-4)M) and Sp-cAMPS (10(-4)M) caused the remarkable stimulation of bone resorption. Although Rp-cAMPS (10(-4)M) did not affect bone resorption by itself, it significantly inhibited dbcAMP- and Sp-cAMPS-induced stimulation of bone resorption. Moreover, Rp-cAMPS (10(-4)M) antagonized 10(-7)M human PTH-(1-34)-induced stimulation of bone resorption, although it did not affect 10(-8)M 1,25(OH)2D3-induced stimulation of bone resorption. Present study indicates the direct involvement of PKA in the stimulation of bone resorption by PTH.

Animals↗
PubMed1992

Effects of gastric inhibitory polypeptide and glucagon on portal venous and hepatic arterial flow in conscious dogs.

Gastric inhibitory polypeptide (GIP) has considerable structural homology with glucagon, which is known to increase liver blood flow. We compared the effects of GIP on portal venous and hepatic arterial flow with those of glucagon in conscious dogs. Injection of GIP significantly increased portal venous flow in a dose-related manner (by 7%, 15%, and 46% at doses of 1, 100, and 500 pmol/kg, respectively). The increase in portal venous flow induced by GIP and glucagon was comparable; however, the increase in portal venous flow after GIP injection reached its peak significantly earlier than that after glucagon injection. Hepatic arterial flow decreased after GIP injection (by 17%, 21%, and 35% at doses of 1, 100, and 500 pmol/kg, respectively), whereas it was not altered by glucagon. Thus, GIP causes significant changes in both portal venous and hepatic arterial flow in conscious dogs. Although structurally related, GIP and glucagon may influence liver blood flow through different mechanisms.

Animals↗
PubMed1992

HIV-1 reverse transcriptase inhibitor from Phyllanthus niruri.

An aqueous extract of Phyllanthus niruri (Euphorbiaceae) inhibited human immunodeficiency virus type-1 reverse transcriptase (HIV-1-RT). The inhibitor against HIV-1-RT in this plant was purified by combination of three column chromatographies, Sephadex LH-20, cellulose, and reverse-phase high-performance liquid chromatography. The inhibitor was then identified by nuclear magnetic resonance (NMR) spectra as repandusinic acid A monosodium salt (RA) which was originally isolated from Mallotus repandus. The 50% inhibitory doses (ID50) of RA on HIV-1-RT and DNA polymerase alpha (from HeLa cells) were 0.05 microM and 0.6 microM, respectively, representing approximately a 10-fold more sensitivity of HIV-1-RT compared with DNA polymerase alpha. RA was shown to be a competitive inhibitor with respect to the template-primer while it was a noncompetitive inhibitor with respect to the substrate. RA as low as 10.1 microM inhibited HIV-1-induced cytopathogenicity in MT-4 cells. In addition, 4.5 microM of RA inhibited HIV-1-induced giant cell formation of SUP-T1 approximately 50%. RA (2.5 microM) inhibited up to 90% of HIV-1 specific p24 antigen production in a Clone H9 cell system.

Antigens, Viral↗
PubMed1992

Qualitative and quantitative changes in islet cells of autotransplanted pancreas in dogs in relation to glucose metabolism.

This study was conducted to clarify the quantitative and qualitative changes in the cells of the islets of Langerhans in the autotransplanted pancreas in dogs and to correlate these changes with alterations of glucose tolerance. The left lobe of a canine pancreas was transplanted into the left iliac fossa. The splenic vessels were anastomosed to the left iliac vessels. The pancreatic duct was left open to the peritoneal cavity. Open biopsies of the autotransplanted pancreas were performed 3, 7, 11, and 14 weeks after transplantation. The islets in the transplanted pancreas were examined ultrastructurally; B-cells, A-cells, and D-cells were identified immunohistochemically and their percentages were determined. Intravenous glucose tolerance tests were performed 3, 5, 7, 11, and 14 weeks after operation, and several indexes (K values and integrated response and increased values for baseline serum and immunoreactive insulin) were calculated. Fibrosis of the transplanted pancreas progressed after transplantation. The percentage of B-cells fell significantly (p < 0.01), whereas that of A- and D-cells did not have significant changes. The ultrastructural study revealed an increase in collagen bundles, degranulation of B-cells, and marked preservation of A-cell granules 3 weeks after transplantation. B-Cells with dark cytoplasm were found 7 weeks after operation. In contrast, clusters of immature B-cells were seen in some sections of the pancreas 14 weeks after autotransplantation. The integrated response in baseline serum was increased significantly (p < 0.01), and the K value was decreased significantly (p < 0.01) 11 weeks after autotransplantation when compared with the initial posttransplant period.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Effects of ethanol and wine on hepatic arterial and portal venous flows in conscious dogs.

The effects of ethanol and wine on hepatic arterial and portal venous flows were examined in conscious dogs. Ethanol was given intravenously or intragastrically, and red wine (ethanol: 14%) was given intragastrically over 30 min. Intravenous ethanol (0.8 g/kg) and intragastric ethanol (14% vol/vol) increased hepatic arterial flow, which remained elevated for 60 min after the cessation of ethanol administration. Ethanol also increased portal venous flow. Portal venous flow returned gradually toward basal levels after the cessation of intravenous ethanol infusion, whereas it remained elevated even after the cessation of intragastric ethanol. Intragastric wine increased hepatic arterial and portal venous flows. In contrast to intragastric ethanol, hepatic arterial flow continued to rise after the cessation of intragastric wine infusion, while portal venous flow returned toward basal levels. We conclude that, though both ethanol and wine increase hepatic blood flow, the responses of hepatic arterial and portal venous flows differ substantially among intravenous ethanol, intragastric ethanol and intragastric wine.

Animals↗
PubMed1992

[Immunohistochemical and ultrastructural study on the islet of autotransplanted pancreas in dogs].

This study was conducted to clarify the quantitative and qualitative changes of the islet cells of Langerhans in the autotransplanted pancreas. The left lobe of the canine pancreas was autotransplanted to the left iliac fossa with pancreatic duct left open to the peritoneal cavity. Fibrosis of transplanted pancreas progressed after transplantation. B-cell ratio was decreased significantly (p less than 0.01) whereas A-cell ratio and D-cell ratio showed no significant changes. Ultrastructural study revealed the increase of collagen/bundle, degranulation of B-cells and well preservation of A-cell granules at 3 weeks after operation. B-cells with dark cytoplasm were found at 7 weeks after operation which indicate the dysfunction of B-cells. In contrast, clusters of immature B-cells appeared on some sections obtained from the pancreas 14 weeks after autotransplantation. On the other hand, K-values were decreased significantly 7 weeks after operation (p less than 0.05). sigma BS (integrated response value of serum glucose level during IVGTT) was increased significantly (p less than 0.01) in addition to the decrease of K-values (p less than 0.01) at 11 weeks after operation. It proved that any indices at 14 weeks after operation showed no significant changes from the control group. It might be possible to speculate that relatively well preservation of glucose tolerance at 14 weeks after operation is associated with some clusters of immature B-cells observed ultrastructurally.

Animals↗
PubMed1992

[Morphometric study on islet of Langerhans in relation to glucose tolerance in chronic obstructive pancreatitis due to pancreatoduodenal cancer].

Twenty one specimens of the pancreas in the patients who underwent pancreatoduodenectomy or total pancreatectomy for pancreatoduodenal cancer were divided into 4 groups according to the extent of fibrosis (Grade 0-Grade III). Islet cells of serial sections were stained immunohistochemically with calculation of the proportion of B-cells, A-cells, D-cells and PP-cells in the islets of Langerhans. In the pancreatic tissue with the most severe fibrosis (Grade III), B-cell ratio was significantly decreased (p less than 0.01), whereas A-cell ratio was significantly increased (p less than 0.01). Based on the data of oral glucose tolerance test (OGTT) and insulin response test, some indices were calculated (delta IRI/delta BS, sigma IRI/sigma BS, sigma delta IRI/sigma delta BS). In Grade III, sigma delta IRI/sigma delta BS was significantly decreased. A significant positive correlation was observed between B-cell ratio and both delta IRI/delta BS or sigma delta IRI/sigma delta BS, whereas a significant negative correlation was seen between A-cell ratio and sigma delta IRI/sigma delta BS. The present study first demonstrates the significant correlation between the endocrine secretory function of the islets and quantitative changes of the endocrine cells of islets in chronic obstructive pancreatitis due to pancreatoduodenal cancer. The present data strongly suggest that it is possible to estimate the degree of fibrosis and quantitative changes of the islet cells in the patients with pancreatoduodenal cancer by means of calculating the above mentioned indices, especially sigma delta IRI/sigma delta BS.

Blood Glucose↗
PubMed1991

Determination of dimethyl sulphide in blood and adipose tissue by headspace gas analysis.

A method for the headspace analysis of dimethyl sulphide in blood and adipose tissue has been established. Blood (0.2 ml) or adipose tissue (0.5 g) with added dimethyl sulphide was sealed in a 10-ml vial using PTFE sheet to prevent escape of dimethyl sulphide from the headspace. Equilibration was performed at 60 degrees C for 4 h, and 20 microliters of gaseous phase sampled from the headspace was subjected to gas chromatography (with flame photometric detection). Calibration curves were prepared for the two samples. Linearity was observed in the range from 5-10 micrograms to 2 mg.

Adipose Tissue↗
PubMed1991

Ostrich crystallins. Structural characterization of delta-crystallin with enzymic activity.

Lens crystallins from the African ostrich (Struthio camelus) were isolated and characterized. Four crystallin fractions corresponding to alpha-, delta/beta- and beta-crystallins similar to those of duck crystallins were isolated, but epsilon-crystallin was found to be absent. The native molecular masses and subunit structures of the purified fractions were analysed by gel filtration. SDS/PAGE and isoelectric focusing, revealing various extents of heterogeneity in each orthologous crystallin class. An ion-exchange chromatographic method was used for the large-scale preparation of delta-crystallin suitable for structural and enzymic studies. It was unexpectedly found that the purified native delta-crystallin of ostrich lens possessed high argininosuccinate lyase activity, in contrast with chicken delta-crystallin. The c.d. spectra indicated a predominant beta-sheet structure in alpha- and beta-crystallins, and a significant contribution of alpha-helical structure in the delta-crystallin fraction. The estimate of secondary structures from c.d. spectroscopy for each crystallin class bears a resemblance to that of duck crystallins, except that ostrich delta-crystallin possesses much less helical content than duck delta-crystallin. Comparison of crystallin compositions and structures from aquatic and terrestrial birds revealed distinct differences.

Amino Acids↗
PubMed1991

Relationship between glucose tolerance and quantitative changes of islet cells in chronic obstructive pancreatitis due to pancreatoduodenal cancer.

This study was conducted to clarify the relationship between indicators of preoperative glucose tolerance and quantitative changes of endocrine cells in the islet of Langerhans in patients with chronic obstructive pancreatitis due to pancreatoduodenal cancer. Twenty-one specimens of pancreatic tissue obtained from patients who underwent pancreatoduodenectomy or total pancreatectomy for pancreatoduodenal cancer were divided into four groups according to the degree of fibrosis (Grades 0-III). Islet cells in serial sections were stained immunohistochemically to determine the proportions of B-, A-, D-, and PP-cells in the islets of Langerhans. In patients with pancreatic tissue with the most severe fibrosis, of several preoperative glucose metabolism indices measured, it was found that the ratio of integrated value of change in serum insulin to that of serum glucose (sigma delta IRI:sigma delta BS) was significantly decreased. There was a significant positive correlation between proportion of B-cells, and both the ratio of change in insulin to that of glucose (delta IRI:delta BS) and sigma delta IRI:sigma delta BS. On the other hand, there was a significant negative correlation between proportion of A-cells and sigma delta IRI:sigma delta BS. The present data strongly suggest that it is possible to estimate the degree of fibrosis and to quantify changes of the islet cells prior to surgery in patients with obstructive pancreatitis due to pancreatoduodenal cancer by calculating these glucose metabolism indices, and that sigma delta IRI:sigma delta BS is a particularly useful index.

Chronic Disease↗
PubMed1991

[A case of pulmonary leiomyoma].

We report a case of pulmonary parenchymal leiomyoma. The patient was a 35- year-old female with a tumor in anterobasal segment of the left lung. Enucleation was performed. The tumor was ball type and 2 cm in diameter, showing smooth and reddish brown cut surface. Microscopic and electron microscopic histology proved it to be leiomyoma.

Adult↗
PubMed1990

Comparison of the gamma-crystallins isolated from eye lenses of shark and carp. Unique secondary and tertiary structure of shark gamma-crystallin.

gamma-Crystallin isolated from the shark of cartilaginous fishes was compared with the cognate gamma-crystallin from the carp of bony fishes. Distinct differences in amino acid compositions, primary, secondary and tertiary structures were found. The most salient features of shark gamma-crystallin lie in the fact that this crystallin possessed a significant alpha-helical structure in the peptide backbone as revealed by circular dichroism study, in contrast to those orthologous gamma-crystallins from other vertebrate species including bony fishes which all show a predominant beta-sheet secondary structure. The tertiary structure as reflected in the intrinsic microenvironments of various aromatic amino acids in the native crystallins also shows unambiguous differences between these two classes of gamma-crystallins. N-Terminal sequence analysis corroborates the structural differences between shark and carp gamma-crystallins. gamma-Crystallin from the more primitive shark seems to be more in line with the main evolutionary phylogeny leading to the modern mammalian gamma-crystallin.

Amino Acid Sequence↗
PubMed1990

Effect of human epidermal growth factor (hEGF) on splanchnic circulation in dogs.

The effect of intravenous administration of human epidermal growth factor on the splanchnic blood flows was examined in anesthetized dogs, using an ultrasonic transit-time volume flow meter. Human epidermal growth factor (0.1, 0.5 and 1 microgram/kg) significantly increased blood flows in the portal vein (36.9 +/- 7.4% at 1 microgram/kg) and the superior mesenteric artery (49.0 +/- 16.8% at 1 microgram/kg). Systemic blood pressure monitored simultaneously was significantly decreased (8.4 +/- 1.2% at 1 microgram/kg). This study is the first to demonstrate that intravenous administration of epidermal growth factor increases the portal venous blood flow.

Animals↗