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Biomedical subjects

T Kitagawa

Publications and source records attributed to T Kitagawa.

At least 685 records · Page 38Linked to original sources
PubMed1981

Natural history of gastric carcinoma with special reference to the "early cancer" stage: a mitotic index study on original and recurrent carcinomas.

The natural history of gastric carcinoma, especially during the "early cancer" stage, was investigated in terms of chronological changes in the mitotic indices of the carcinoma. Nine cases of gastric carcinoma which recurred after long periods of time were analyzed. In seven cases in which a second operation was performed after 2 approximately 14 years, the mitotic indices of the recurrent carcinomas were about the same as or slightly higher than those of the original ones. On the other hand, in 3 cases in which second operations were done within 2 years, the mitotic indices were lower in the recurrent carcinomas. No general trend toward a change in mitotic indices, relative to either the surface topography or the depth of the stomach wall at the site of the carcinoma, was observed, although there was one exceptional case in which a distinctly elevated mitotic index was obtained at the site of the nodular down-growth of the carcinoma associated with apparent morphological features of progression. In 5 out of 7 cases with lymph node metastasis, the mitotic indices in the metastatic site were slightly higher than in the original carcinoma. The overall impression gained from the present study was of the unchangeability of the cell kinetics of gastric carcinomas during the long early cancer stage, although the results also indicate the gradual or abrupt progression of carcinomas during their natural history. The mechanisms which produced reduction in the growth rates of carcinomas within 2 years after operations are discussed.

Adult↗
PubMed1980

Resonance Raman evidence for cleavage of the Fe-N epsilon(His-F8) bond in the alpha subunit of the T-structure nitrosylhemoglobin.

Resonance Raman spectra are observed for hybrid nitrosylhemoglobins (NO-Hb) reconstituted from normal and meso-deuterated hemes and also for penta- and hexa-coordinated NO-heme complexes. Upon meso deuteration of both hemes of the alpha and beta subunits [alpha(D)2NO beta(D)2NO], the Raman lines of stripped NO-Hb at 1636 (dp), 1584 (ap), and 1502 (p) cm-1 are shifted by -10, -20, and -7 cm-1, respectively, and those at 1306 (ap) and 1228 (dp) cm-1 disappear. The spectral changes caused by meso deuteration are in good agreement with those observed previously for (octaethyl-porphyrinato)nickel(II), for which the vibrational assignments of resonance Raman lines have been established. Accordingly, the 1636-, 1584-, 1502-, 1306-, and 1228-cm-1 lines of NO-Hb are assigned to nu 10, nu 19, nu 3, nu 21, and nu 13, respectively. Upon conversion from the R to the T structure, both nu 19 and nu 3 are shifted to higher frequencies by 4 cm-1 and nu 10 is split into two lines at 1645 and 1637 cm-1. The 1645-cm-1 line remains unshifted after meso deuteration of the beta heme [alpha(H)2NO beta-(D)2NO], and, conversely, the 1637-cm-1 line remains unshifted after meso deuteration of the alpha heme [alpha(D)2NO beta(H)2NO]. On the basis of the Raman spectra of the model NO-heme complexes, the 1645- and 1637-cm-1 lines are assigned to the penta- and hexacoordinated NO-heme complexes. Consequently, we conclude that the Fe-N epsilon(His-F8) of the alpha subunit within NO-Hb is disrupted in the T structure, while the NO-heme of the beta subunit adopts the hexacoordinated structures, in good agreement with our previous electron paramagnetic resonance work. The Raman spectra of the isolated alpha NO and beta NO chains are appreciably different. The Raman lines of the isolated alpha NO chain at 1606 (p), 1587 (ap), and 1504 (p) cm-1 are shifted by -6, +5, and +4 cm-1 when it is incorporated into the T-structure tetramer. In contrast, all the Raman lines of the isolated beta NO chain are not shifted in the T-structure tetramer.

Chemical Phenomena↗
PubMed1980

Resonance Raman spectra of octopus acid and alkaline metarhodopsins.

The resonance Raman spectra of acid and alkaline metarhodopsins of octopus were measured. The acid metarhodopsin exhibited the Schiff base C = N stretching band at 1655 cm-1 in H2O and at 1625 cm-1 in 2H2O, and therefore the Schiff base is shown to be protonated. The C = C stretching band was observed at 1548 and 1572 cm-1 for acid and alkaline metarhodopsins, respectively. Other Raman lines of octopus acid metarhodopsin were assigned from the data of Cookingham et al. (Cookingham, R.E., Lewis, A. and Lemley, A.T. (1978) Biochemistry 17, 4699-4711). Frequencies of some structure-sensitive Raman lines differed among octopus, squid and bovine metarhodopsins; such differences may be important in interpreting the presence of optical activity in octopus metarhodopsins but its absence in squid metarhodopsins.

Animals↗
PubMed1980

Influence of quaternary structure on the state of the haem in carp and human methaemoglobins studied by resonance Raman scattering.

the resonance Raman spectra of carp and human methaemoglobin (metHb) derivatives in the T and R quaternary structures were measured in the frequency regions of 1200-1700 cm-1 and 100-600 cm-1. Conversion of carp and human fluoro metHb's to the T structure was accompanied by a frequency shift of the Raman line at 348 cm-1 to lower frequency by 5 cm-1, but all other lines were unaffected by the R-T transition. As the 348 cm-1 line was assigned to a porphyrin mode (v8) involving a bending motion of peripheral groups, the frequency change may be attributable to a change in van der Waals' interaction between haem and globin. On addition of inositol hexaphosphate to carp azide metHb, the intensity ratios of Raman lines (cm-1/cm-1), 1588/1567, 1641/1606, and 349/377, decreased. This indicates a shift of the high-spin/low-spin equilibrium towards high-spin side, in agreement with the rise in magnetic susceptibility. No distinct change was detected for the Raman spectra of aquo and cyano met Hb's on the R-T transition, even in the lower frequency region.

Animals↗
PubMed1980

Protein synthesis in transformed 3T3 cells permeabilized by exogenous ATP.

Exogenous ATP has been shown to cause a rapid and reversible increase in permeability in transformed 3T3 cells (3T6 and SV3T3) but not in untransformed 3T3 cells. The cells remain viable, but lose intracellular acid-soluble pools. Treatment of transformed cells with ATP greatly reduces incorporation of 14C-leucine into protein, which is restored by the incubation of the cells with Dulbecco's modified Eagle's medium or by the external additions of certain ions and energy sources. tRNA is not required for the restoration of protein synthesis. In the permeabilized cells the energy for protein synthesis can be provided by glycolysis, oxidative phosphorylation, or direct addition of ATP. These studies demonstrate the usefulness of this method for studying the control of metabolism and macromolecular synthesis in monolayer cultures of transformed mammalian cells.

Adenosine Diphosphate↗
PubMed1980

Prenatal diagnosis of I-cell disease by measuring altered alpha-mannosidase activity in amniotic fluid.

Prenatal diagnoses of I-cell disease were carried out by examination of the amniotic fluid and cultured amniotic cells in four cases of high-risk pregnancy in three different families. Three of the four fetuses were diagnosed as having I-cell disease, on the basis of observation of abnormally increased activity of lysosomal acid hydrolases in the amniotic fluid and their decreased activity in cultured amniotic cells, thus leading to therapeutic abortion. alpha-Mannosidase in the amniotic fluid of the fetuses with I-cell disease exhibited significant alterations in pH profile Km value, thermal stability and isoelectric focusing pattern, compared with the enzyme in normal controls. The results indicate that prenatal diagnosis of I-cell disease may be accomplished by demonstration of altered enzymological characteristics of alpha-mannosidase in the supernatant of amniotic fluid. The significance of the alteration of alpha-mannosidase in the amniotic fluid is not known.

Amniotic Fluid↗
PubMed1980

Differences in Fe(II)-N epsilon(His-F8) stretching frequencies between deoxyhemoglobins in the two alternative quaternary structures.

Resonance Raman spectra have been obtained of the alpha deoxy and beta deoxy subunits within valency hybrid hemoglobins both in the high-affinity (R) and low-affinity (T) structures. Upon conversion from the R to the T structure, the vibrational frequency of the Fe(II)-N epsilon(His-F8) bond changes from 223 to 207 or 203 cm-1 in the alpha deoxy subunit and from 224 to 220 or 217 cm-1 in the beta deoxy subunit. We estimate that the Fe(II)-N epsilon(His-F8) bond is stretched by the R leads to T transition 3 times more in the alpha subunit (0.024 A) than in the beta subunit (0.0085 A) and, accordingly, the strain energy developed in that bond is 8 times larger in the alpha than in the beta subunit. Hence, the oxygen affinity of the alpha and beta subunits may be regulated by different mechanisms.

Allosteric Regulation↗
PubMed1980

Proton nuclear-magnetic-resonance and resonance Raman studies of thermophilic cytochrome c-552 from Thermus thermophilus HB8.

The pH and temperature dependences of the 270-MHz proton nuclear magnetic resonance and resonance Raman spectra of Thermus thermophilus cytochrome c-552 were studied. Observation of the NMR methyl signal of the iron-bound methionine indicates that a methionine residue is the sixth ligand of heme iron in both ferric and ferrous states, although the environment of this methionine is not similar to that in mitochondrial cytochrome c. The NMR methyl signal of the coordinated methionine in the ferrous state was observed even at 87 degrees C, indicating the retention of the methionine ligand at the sixth coordination position. None of resonance Raman lines in ferrous cytochrome c-552 at higher temperatures showed a prominant temperature-dependent frequency shift, which implies that the heme iron was still bound with strong ligands and retained the low-spin state. In either redox state overall thermal denaturation did not occur even at 87 degrees C, although the ferric form existed in thermal spin mixture of the low-spin and high-spin species at higher temperatures. The hyperfine-shifted NMR resonances of the ferric form indicated rapid exchange of the sixth ligand at alkaline pH in the process of a single-step alkaline isomerization.

Cytochrome c Group↗
PubMed1980

Biologic and therapeutic effects of 1 alpha-hydroxycholecalciferol in different types of Fanconi syndrome.

The plasma 1,25-(OH)2VD3 level in Fanconi syndrome was low but rose rapidly following the administration of 1 alpha-OHVD3. 1 alpha-OHVD3 was administered to 6 patients with different types of Fanconi syndrome. The effect of 1 alpha-OHVD3 proved to be 200-250 times as great as that of vitamin D2. From our results it was suggested that Ca malabsorption due to failure of 1 alpha-hydroxylation of vitamin D in the kidney, together with renal tubular acidosis and hypophosphatemia, is involved in the pathogenesis of the rickets of Fanconi syndrome.

Adolescent↗