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H Kitamura

Publications and source records attributed to H Kitamura.

At least 469 records · Page 26Linked to original sources
PubMed1986

Analysis of growth fractions and stem cell compartments in transformed rat tracheal epithelial cell colonies.

The purpose of the studies described here was to define the biological behavior of the various clonally transformed colonies observed in cultures of carcinogen-exposed rat tracheal epithelial cells. As described in the preceding paper (H. Kitamura et al., Cancer Res., 46: 4631-4641, 1986), these colonies fall into four morphologically distinct categories. In the studies reported here we found that type I colonies had the smallest growth fraction (7%) and contained the lowest frequency of clonogenic cells (approximately 10(-3)). Colonies of types II to IV had mean growth fractions of 21 to 28%, and the frequency of clonogenic cells was 2 to 5 X 10(-2) when measured under growth-permissive conditions (3T3 feeders). When the clonogenic cell assays were performed under selective conditions to identify cell variants which can grow without feeder support, the average frequency of such clonogenic cells in type I colonies was less than 4 X 10(-5) and in colonies of types II to IV, between 5 X 10(-4) and 10(-2). In type IV colonies, the total number of cells per colony increased 8-fold between 5 and 12 wk postcarcinogen, but the clonogenic cell compartment increased 42-fold; the compartment of variant clonogenic cells, which are able to replicate on plastic, increased 139-fold during the same period of time. This indicated that major changes in the self-renewal capacity of the clonogenic cells were taking place during this early stage of transformation. Examination of the daughter colonies produced by replating colonies of types I to IV revealed that clonogenic cells with different growth potential existed within the same parent colony. Comparison of transformed colonies of the same type showed a marked degree of heterogeneity in the sizes of growth fractions and clonogenic cell fractions. These studies further indicated that, within all colonies, including the most advanced transformants, the majority of the cells were nonreplicating, terminal cells, suggesting that, at least during early stages of transformation, the transformed characteristics were not transferred from parent to daughter cells. With the exception of type I colonies, most of the colonies recognizable at 5 wk after carcinogen exposure progressed with time and acquired the morphological characteristics of type IV colonies, which were the most transformed phenotype. We conclude that transformation of rat tracheal epithelial cells is an asynchronous process and that the morphologically distinct types of rat tracheal epithelial cell colonies represent different stages of the clonal evolution of transformants.

Animals↗
PubMed1986

The activation of C5 in the fluid phase and in the absence of C3 through the classical pathway of the complement system.

Unsensitized guinea-pig erythrocytes (Egp) were lysed by a combination of eight isolated, human-derived complement components, Cls, C4, C2, C5, C6, C7, C8 and C9 (Cls-C9exC3), even in the presence of anti-C3. It was determined that a factor was generated in the reaction mixture of Cls, C4, C2, C5 and C6, which had a lytic activity against Egp when C7, C8 and C9 were added. The lytic factor was similar to C56 in the following properties: the activity of the lytic factor decreased when incubated with C7 prior to its reaction with Egp, the lytic factor did not bind to Egp by itself but it did bind in the presence of C7, EDTA did not have any inhibitory effect on the lytic factor, and the activity of the lytic factor was lost by treatment with anti-C5 or anti-C6 but not by treatment with anti-C4. Furthermore, C5a, a cleavage product of C5, was clearly detected in the reaction mixture of Cls, C4, C2 and C5. These findings indicate that C5 can be activated proteolytically into C5a and C5b in the fluid phase solely by the classical pathway C3 convertase, C42, without any participation of C3.

Animals↗
PubMed1986

C3-independent immune haemolysis: mechanism of membrane attack complex formation.

The isolated active complex of C5 and C6, C56, was found to bind to EAC142 in the absence of C3 or C7, and to form a unique intermediate, EAC14256, which is susceptible to lysis by the addition of C7, C8 and C9. Further studies revealed that C56 alone could bind to EAC142 but not to E, EA, EAC1 or EAC4, nor to EAC14 in the absence of C7, that the C56 binding to EAC142 was highly dependent on temperature and on the ionic strength of the buffer, and that the degree of EAC14256 formation from EAC142 and C56 depended on the amount of C2 on EAC142 and on the amount of added C56. These findings suggest that C2 or C42 on EAC142 may be an acceptor for C56. In addition, C56 appears to bind to EAC142 much more efficiently than to unsensitized erythrocytes, even in the presence of C7. Thus, binding of C56 to EAC142 is likely to be an initial step of membrane attack complex formation in C3-independent immune haemolysis.

Animals↗
PubMed1986

[Cardiac inotropic reserve examined by postextrasystolic potentiation and redistribution of exercise thallium-201 scintigraphy].

Evaluation of regional contractile reserve and the viability of an infarcted segment of the myocardium is very important in determining the indications for aorto-coronary bypass after myocardial infarction and in predicting the prognosis. Regional wall motion of the left ventricle after postextrasystolic potentiation (PESP) was studied in 18 patients with old myocardial infarction, and compared with indices of redistribution of thallium after exercise. Equilibrium radionuclide angiocardiography (RNA) using Tc99m HSA was performed at rest and after PESP produced by a programmable cardiac stimulator via a right ventricular catheter. Regional ejection fractions (REF) were determined, and wall motion was observed visually. The relative thallium activity (RTA) and washout rate (WOR) were obtained from exercise myocardial scintigraphy performed 10 minutes, and 3 hours after thallium-201 injections. Wall motion improved in 12 of 23 infarcted segments after PESP. Regional ejection fraction and relative thallium activity (in three hours, or the difference between the activities of the initial and three hours after exercise) in the improved segments were significantly higher (p less than 0.001) than in the unchanged segments. Washout rate was lower (p less than 0.02) in the improved segments. Significant correlation was observed between the change in regional ejection fraction and relative thallium activity (3 hours after exercise) (r = 0.654, p less than 0.05). Thus, the wall motion of some infarcted regions of the myocardium improved after PESP, and thallium was redistributed during three hours after exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise Test↗
PubMed1986

NK cell activity in asbestosis.

Natural killer (NK) cell activity was studied in 40 asbestos workers with chest roentgenographic signs of asbestosis and 54 sex- and age-matched healthy controls. NK cell activity in asbestosis was 32.3 +/- 18.2%, significantly higher than that in healthy controls (17.4 +/- 12.2%). We also examined the relationship between NK cell activity and the duration of exposure, and that between NK cell activity and the ILO U/C classification of radiographs. NK cell activity tended to decrease relatively in the presence of lung cancer.

Adenocarcinoma↗
PubMed1985

A sensitive method for the histochemical demonstration of vicinal diols of carbohydrates.

A new sensitive method has been established for the histochemical demonstration of vicinal diols of carbohydrates in light microscopy. It consists of a periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) sequence followed by physical development. The new method is more sensitive than the PA-TCH-SP and periodic acid-Schiff (PAS) methods employed hitherto. Its specificity is sufficient.

Alcohols↗
PubMed1985

Three-dimensional network of microtubules in secretory ameloblasts of rat incisors.

Secretory ameloblasts appear to contain isolated microtubules and microtubules arranged in bundles associated with filaments or sheets of filaments. The relation between isolated and bundled microtubules in secretory ameloblasts was investigated by serial sections. Some isolated microtubules entered microtubule bundles in adjacent sections. Microtubules which diverged from a bundle sometimes converged into another bundle in other sections. Microtubules were associated with filaments or sheets of filaments for varying distances. It is concluded that isolated microtubules frequently form bundles by joining with other microtubules, and thus, microtubules make a three-dimensional network throughout the whole cytoplasm which is probably concerned with the transport of secretion granules.

Ameloblasts↗
PubMed1985

Actin filaments in the terminal webs of secretory ameloblasts of rats.

Actin filaments decorated with heavy meromyosin in enamel-secreting ameloblasts of rat incisors were examined. Proximal and distal terminal webs contained actin filaments; some were arrayed in diverse directions to each other. Some were associated with coated and uncoated vesicles. These actin filaments may relate to the sideways movement of secreting ameloblasts, suggesting that the distal terminal web is an apparatus generating a force by which ameloblasts can slide over each other.

Actins↗
PubMed1985

Mechanisms of growth inhibition by propionate and restoration of the growth by sodium bicarbonate or acetate in Rhodopseudomonas sphaeroides S.

Mechanisms of growth inhibition by propionate on the growth of Rhodopseudomonas sphaeroides were studied. Partially purified pyruvate dehydrogenase complex (PDC) from R. sphaeroides was inhibited by propionyl-CoA, one of the metabolic intermediates of propionate, while propionate itself did not inhibit the enzyme. This suggests that the inhibitor of the growth in vivo is not propionate but propionyl-CoA. The inhibition by propionyl-CoA was competitive with respect to coenzyme A concentration. The K1 value for propionyl-CoA was 0.84 mM. Addition of NaHCO3, which restored the growth of this bacterium in the presence of propionate, increased the rate of propionate incorporation by 1.7-fold and decreased the intracellular level of propionyl-CoA by half. These findings suggest that HCO3-ion lowers the level of propionyl-CoA by accelerating its carboxylation reaction, which is catalyzed by propionyl-CoA carboxylase. Effects of NaHCO3 and acetate on the growth restoration were also studied by the use of propionyl-CoA carboxylase-deficient mutants. NaHCO3 did not restore the growth of the mutants, indicating an essential role of propionyl-CoA carboxylase on the restoration of growth by NaHCO3 as suggested above. Addition of acetate restores the growth of the mutants in the presence of propionate. Acetate probably restores the growth by supplying acetyl-CoA.

Acetates↗
PubMed1985

PaO2 change during progressive pulmonary edema in dogs.

We observed the changes of PaO2, pulmonary shunt (Qsp/Qt), effective compliance, and direct lung impedance after induction of hydrostatic pulmonary edema in five mongrel dogs. Edema was induced by elevating left atrial pressure in a stepwise manner while the dogs were ventilated with continuous positive pressure. Corresponding morphologic changes in the lung were examined by light and electron microscopy. PaO2 changed little or slightly until mean left atrial pressure reached 40 to 60 mm Hg. PaO2 then rapidly decreased from 411 +/- 61 to 89 +/- 19 torr, accompanied by an increase in Qsp/Qt from 33 +/- 6% to 57 +/- 14%. Effective compliance decreased gradually and direct lung impedance decreased rather steeply at first and then gradually. Lung specimens taken before the abrupt fall of PaO2 revealed froth on the cut surface, indicating that alveolar pulmonary edema preceded the PaO2 decrease. Electron microscopy showed widening and splitting of the thin portion of the alveolar-capillary interstitium when PaO2 fell abruptly. This widening of the thin portion may have been one of the causes of an abrupt PaO2 fall in the dog subjected to volume overload and increased afterload.

Animals↗
PubMed1985

Primary signet-ring cell carcinoma of the urinary bladder. Report of two cases with histochemical studies.

Two cases of primary signet-ring cell carcinoma of the urinary bladder are presented with histochemical studies. The signet-ring cell carcinoma of the bladder is a rare variant of mucus-producing vesical adenocarcinoma: sixteen cases have been reported in the Occidental and two other cases in Japanese literature. Most of the cases were discovered in the advanced stage and the prognosis was poor: necessity of early detection by cytological examination and treatment with surgery is stressed. The histochemical evidence for the similarity of the neoplasm to colonic epithelium in mucus production is illustrated and the grade of malignancy is discussed from the view of mucus production by the neoplasms.

Adenocarcinoma↗
PubMed1985

Systemic lupus erythematosus with multiple calcified fibrous nodules of the spleen.

An autopsy case of systemic lupus erythematosus (SLE) in a 39-year-old woman with peculiar multiple splenic nodules is reported. Multiple calcific nodular shadows were incidentally found in the left hypochondrial region on chest and abdominal X-ray films taken at admission. The patient died of chronic heart failure due to massive pericardial effusion as one of the manifestations of SLE with 2 and a half years' clinical course. Lupus nephritis and terminal miliary tuberculosis were the other conspicuous autopsy findings. The splenic nodules were almost evenly distributed on each cut-surface of the spleen at the density of about 5/cm2. Each nodule was spherical in shape and 1 to 3 mm in diameter. Most of the nodules were calcified in variable degrees. Semi-serial sectionings and reconstruction procedure of the nodules disclosed that they were formed around the central or penicillary arteries and had a close relation to so called "onion-skin lesion" of the spleen in SLE. The true nature, pathogenesis, and relation of the nodules to SLE are discussed.

Adult↗
PubMed1985

Light and electron microscopic studies on capillaries of the goat cardiac muscle with special reference to the topographical relationship between the vessels and Purkinje fibers.

The capillaries of the cardiac muscle were investigated in the goat by means of light microscopy, transmission electron microscopy and scanning electron microscopy, and the following results were obtained. The capillaries of the working cardiac muscles were numerous, arranged mainly parallel to the long axis of muscle cells and formed dense elongated networks. On the contrary, those of the terminal Purkinje fibers were relatively few in number, oriented in various directions and formed loose and circularly meshed networks surrounding the fibers. Such findings were discussed in correlation with the physiology and functional morphology of various types of the cardiac muscle cells.

Animals↗
PubMed1985

C6 polymorphism in Japanese: typing by agarose gel isoelectric focusing-immunofixation.

Agarose gel isoelectric focusing was used to investigate the genetic polymorphism of the sixth component of complement (C6) in Japanese. C6 patterns were visualized by the immunofixation procedure. The allele frequencies calculated from 135 individuals were as follows: C6*A = 0.467, C6*B = 0.481, C6*B2 = 0.037, and C6*B3 = 0.015. It is suggested that C6*B3 is the fourth common allele characterizing the Japanese population.

Adult↗
PubMed1985

C3 variants in Japanese.

By high-voltage agarose gel electrophoresis, seven phenotypes of C3 were found in Japanese. The allele frequencies for C3*S, C3*S025, C3*S02, C3*F, C3*F06, C3*F065, and C3*F08 were 0.9943, 0.0003, 0.0003, 0.0006, 0.0003, 0.0021, and 0.0021, respectively. CH50, C3/C3c protein concentrations, and C3 hemolytic activities in fresh sera with variant C3 phenotypes were within the normal ranges.

Adult↗