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Biomedical subjects

K Iriyama

Publications and source records attributed to K Iriyama.

At least 73 records · Page 4Linked to original sources
PubMed1985

Unique electronic property of a Langmuir-Blodgett film of dioleyl lecithin deposited on a porous membrane.

The current-controlled voltage characteristics across a Langmuir-Blodgett film of dioleyl lecithin deposited on a fine-pore membrane between equimolar aqueous solutions of NaC1 and KC1 were studied. This membrane was found to exhibit the properties of switching and differential negative-resistance. These unique electronic properties are interesting in relation to excitable phenomena in biomembranes.

Electrochemistry↗
PubMed1985

Rectoanal pressures and rectal compliance in children with rectal prolapse.

The results of anorectal manometry in 11 children with complete rectal prolapse were evaluated. Abnormalities of sphincter control or bowel movements occurred in 8 out of these 11 patients. Anal canal pressure of the patients was lower than in the controls, but there was no significant difference of resting pressure profiles of the anorectum between the patients and the controls. Rectoanal reflex was present in all the patients and in the controls. Rectal compliance was significantly lower in the patients, but there was no correlation between rectal compliance and sphincter control of the patients.

Anal Canal↗
PubMed1985

Nitrogen-sparing effect of lipid emulsion in septic dogs.

Effects of intravenously administered lipid emulsion on the nitrogen balance in dogs with intraabdominal infection were investigated. The nitrogen balance in dogs supported by parenteral nutrition (PN) with glucose alone was superior to that in dogs supported by PN with glucose and lipid emulsion, in the absence of intraabdominal infection. On the other hand, the nitrogen balance in dogs supported by PN with glucose and lipid emulsion was superior to that with glucose alone, in the presence of intraabdominal infection. Dogs with intraabdominal infection had an insulin-resistance inability to effectively utilize glucose.

Animals↗
PubMed1985

Cytophotometric DNA analysis of rectal mucosa of patients with ulcerative colitis.

Cytophotometric DNA analysis of rectal mucosa was carried out in 11 patients with ulcerative colitis, in attempt to determine the proliferative activity of rectal mucosa. There was no significant difference in the mean DNA value, modal DNA value, total variation of DNA content and population of over 3c cells of rectal mucosa between controls and the patients. However, the differential determination of the proliferative activity in the upper, middle and lower thirds of the crypt disclosed that a population of over 3c cells in the upper and middle thirds of the crypt was significantly larger in the patients with longstanding disease than in the controls.

Adult↗
PubMed1985

Tissue CEA determination and cytophotometric DNA analysis of colorectal mucosa in patients with colorectal cancer.

Determination of tissue CEA content and cytophotometric DNA analysis of colorectal mucosa were carried out in 45 patients. Tissue CEA content in mucosa of tumor-bearing patients was significantly higher than in mucosa of the controls. In mucosa of the patients, tissue CEA content of transitional mucosa was significantly higher than that of background mucosa. Cytophotometric DNA analysis of colorectal mucosa disclosed that over 3c cells were not found in the upper third of the crypt in the controls, whereas appearance of these cells in the luminal surface of the crypt was characteristic in tumor-bearing patients. The population of over 3c cells in the upper third of the crypt was significantly larger in patients with multiple cancers or cancer accompanied by adenomas, than in the patients with solitary colorectal cancer.

Adenocarcinoma↗
PubMed1985

[Clinical assessment of sulbactam/cefoperazone in comparison with ceftizoxime in patients with postoperative infections by well controlled method].

The clinical effectiveness in postoperative infections of sulbactam/cefoperazone (SBT/CPZ, (SBT 0.5 g+ CPZ 0.5 g) X 2/day) was compared to that of ceftizoxime (CZX, 1.0 g X 2/day) by a well controlled comparative study, to have the following results. The overall effectiveness rate of SBT/CPZ and CZX as judged by Judgement Committee was 84.0% (63/75) and 80.6% (50/62), respectively, and the effectiveness of SBT/CPZ and CZX as assessed by the attending surgeons was 84.0% (63/75) and 71.0% (44/62), respectively. No significant difference was noted in both assessments. In a total of 36 SBT/CPZ-treated patients with intraabdominal infections, the clinical efficacy was judged by attending surgeons to be excellent in 13 patients (36.1%), and to be excellent or good in 31 (86.1%). In the 30 CZX treated patients, it was judged to be excellent in 6 patients (20.0%), and to be excellent or good in 19 (63.3%). These results presented a significant difference (P less than 0.05, U-test) between the 2 drug groups. The final global improvement ratio judged by attending surgeons was 85.3% (64/75) for SBT/CPZ, and 79.0% (49/62) for CZX with no significant difference. In assessment of time-course improvement, the improvement ratio of SBT/CPZ on day 4 was significantly better than that of CZX (P less than 0.05, U-test). The usefulness rate of SBT/CPZ and CZX was 84.0% (63/75) and 73.0% (46/63), respectively. There was no significant difference between the 2 drug groups. To assess the bacteriological efficacy, the eradication rate of SBT/CPZ was compared to that of CZX. There was no significant difference between 85.7% (36/42) for SBT/CPZ and 73.5% (25/34) for CZX. After SBT/CPZ administration, 2 patients (2.5%) complained of side effects. In the clinical laboratory tests, abnormality related to SBT/CPZ medication was observed in 6 patients (7.5%), and that related to CZX, in 5 patients (6.4%). As to the types of side effects and frequency, no significant difference was observed between SBT/CPZ and CZX. It is concluded from the above assessments that SBT/CPZ is a useful drug in the treatment of post-operative infections.

Adolescent↗
PubMed1985

[Adenosquamous carcinoma of the stomach].

The appearance of adenosquamous structures in cancer of the stomach was studied in 385 resected specimens. Such structures were observed in 9.1% of the specimens. However, they were not found in cases in which the invasion was limited to the mucosa. The frequency of the appearance increased in correlation with the extent of the cancerous invasion. The type of adenocarcinoma that coexisted with the squamous changes was the intestinal type of Lauren in 68% of the specimens. This indicates that the squamous structures, seen in gastric cancer result from secondary metaplasia of the intestinal type in this condition.

Adenocarcinoma↗
PubMed1984

Postmortem changes of uric acid in various rat tissues: determination of uric acid by reversed-phase high-performance liquid chromatography with electrochemical detection.

As a function of time after decapitation, postmortem changes of uric acid in various rat tissues have been studied by reversed-phase high-performance liquid chromatography with electrochemical detection. The chromatographic examination revealed that uric acid in rat tissues such as brain, liver, musculus rectus abdominis, and femoral muscle tends to increase after decapitation as a function of time between the sacrifice and homogenization in a 2.0% metaphosphoric acid solution.

Animals↗
PubMed1984

Oscillation of electrical potential in a porous-membrane doped with triolein induced by an Na+/K+ concentration gradient.

The electrical potential across a fine pore membrane doped with trioleoyl glyceride (triolein) and separating aqueous solutions of 0.5M NaCl and 0.5M KCl, respectively, was studied. It was found that this system showed rhythmic and sustained oscillations of electrical potential between the two aqueous solutions. These oscillations were attributed to the change of permeability of Na+ and K+ ions across the membrane, which originated from the phase-transition of triolein molecules within the fine pores.

Mathematics↗
PubMed1984

Simultaneous determination of uric and ascorbic acids in human serum by reversed-phase high-performance liquid chromatography with electrochemical detection.

A rapid, easy, and accurate method for the determination of uric acid and ascorbic acid in human serum by reversed-phase high-performance liquid chromatography with electrochemical detection has been developed. Human serum (0.5 ml) was mixed with 1.5 ml of an aqueous solution containing 2.0% metaphosphoric acid and the mixture was centrifuged at 3000g for 30 min. The supernatant was passed through a membrane filter to remove the particulate matter. Ten microliters of the filtrate was injected into the chromatographic system employed in this study. Complete separation of uric acid and ascorbic acid was achieved in about 2 min. The assay limit for quantitation was about 10 pg for uric acid and ascorbic acid under the present chromatographic conditions. The analytical recoveries of uric acid and ascorbic acid in human serum samples were found to be almost 100%.

Ascorbic Acid↗
PubMed1984

Raman spectroscopic evidence for the microenvironmental change of some tyrosine residues of lens proteins in cold cataract.

Reversible "cold cataract" phenomenon of a SD-strain rat lens (29 days old) was studied by Raman spectroscopy in the temperature range of 35-17.5 degrees C. Cold cataract appeared in the lens nucleus below 26 degrees C. The Raman spectra did not show any detectable change in the 300-800 cm-1 and 900-4000 cm-1 regions as the temperature decreased. However lens opacification caused a significant change in the intensity ratio of tyrosine doublet near 840 cm-1, suggesting that some tyrosine residues in lens proteins undergo a change in their hydrogen bonding environment during the cold cataract formation. It was also found that the intensity ratio of the tyrosine doublet band provides a practical indicator of phase transition temperature of cold cataract.

Animals↗
PubMed1983

Raman spectroscopic study of age-related structural changes in the lens proteins of an intact mouse lens.

Age-related structural changes in the lens proteins of a normal mouse lens have been monitored in situ by laser Raman spectroscopy. The Raman spectrum of an ICR-strain mouse lens nucleus showed virtually no change in the 550-850- and 900-1800-cm-1 regions as the mouse aged. Lens aging, however, did cause a significant intensity decrease of the Raman band at 880 cm-1 due to tryptophan residues, and the intensity decrease seems to be stepwise. This observation implies that a microenvironmental change of tryptophan residues takes place twice at different places of the lens proteins during normal aging. Particularly striking is that the intensity decrease of the band at 880 cm-1 proceeds in parallel with that of the Raman band at 2579 cm-1 due to a SH stretching mode for the first 4 months. Thus, the first microenvironmental change of tryptophan residues seems to be correlated with the formation of S-S bonds. In contrast to tryptophan residues, no evidence was observed of a microenvironmental change in tyrosine residues. In this respect, the structural changes of lens proteins in aging are sharply distinct from those in lens opacification, in which tyrosine as well as tryptophan residues undergo microenvironmental changes [Itoh, K., Ozaki, Y., Mizuno, A., & Iriyama, K. (1983) Biochemistry 22, 1773-1778]. The relative intensity of the band at 3390 cm-1 due to an OH stretching mode of lens water fell rapidly for the first 4 months and then decreased very gradually. The observation clearly exhibits the process of lens dehydration.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1983

Structural changes in the lens proteins of hereditary cataracts monitored by Raman spectroscopy.

Raman spectra have been measured for the lenses from cac-strain mice. These mice possess a hereditary defect and provide lenses at various stages of opacification. The Raman spectra of normal mouse lenses have been obtained also for comparison purposes. The amide I and III bands appear in very similar positions in the Raman spectra of cataractous and normal lenses, suggesting that the peptide backbone of main lens proteins does not undergo a major conformational change upon lens opacification. However, lens opacification causes significant changes in the intensity ratio of the tyrosine doublet near 840 cm-1 and in that of the Raman bands at 881 and 760 cm-1 due to tryptophan residues. These changes could be observed even in the incipient stage of hereditary cataract and became more pronounced with cataract development. These observations indicate that in the course of lens opacification some tyrosine residues undergo a change in their hydrogen-bonding environment and some buried tryptophan residues became exposed. In addition, the present Raman spectroscopic study provides insight into the 2SH leads to S-S conversion in lens proteins. It was found that the conversion proceeded at a faster rate in a hereditary cataractous lens than in a normal lens; however, this difference was fairly small at the early stage of cataract development. Importantly, the 2SH leads to S-S conversion was accelerated after nuclear cataract formation. These observations support the hypothesis that the formation of S-S linkages is not a predominant factor for initiating lens opacification. Probably the formation of S-S linkages plays an important role in stabilizing the protein aggregates which are the cause of lens opacification. The intensity of the SH stretching mode (2579 cm-1) was very weak or absent in the Raman spectrum of a well-developed cataractous lens, suggesting that most sulfhydryl groups form disulfide bonds. Moreover, the fact that this occurs without major conformational changes of peptide backbones implies that most cysteine residues in lens crystallins are accessible to solvent or are clustered closely together.

Aging↗
PubMed1983

Experimental ischemic colitis in dogs.

Experimental ischemic colitis was produced in 42 dogs by either ligation (ligation group, n=18) or temporary occlusion of the mesenteric vessels (temporary occlusion group, n=24) and changes in the local blood flow in the bowel were measured by the hydrogen clearance method. Tissue damage similar to damage seen in patients with ischemic colitis were produced in both of these groups. There was a close correlation between the severity of the ischemia and the ensuing tissue damages. In the ligation group, the tissue damages ranging from erosions or minute ulcerations to diffuse ulcerations occurred when the local blood flow was measured at 30 minutes after the ligation and was below 50 per cent of the basal flow. In the temporary occlusion group, the tissue damages were observed when the local blood flow was below 40 per cent of the basal flow and the occlusion was maintained for over two hours.

Animals↗
PubMed1983

Effects of hemodynamic changes induced by hyper- or hypothermia on intravenous lipid clearance rate and lipoprotein lipase activity in dogs.

Hyper- and hypothermia was induced in dogs by peritoneal perfusion with warm or cold Lactate-Ringer's solution, the objective being to alter cardiac output. Changes in cardiac index, intravenous lipid clearance rate (K-value), and lipoprotein lipase (LPL) activity, concomitantly with changes of the temperature of the mixed venous blood were investigated. The cardiac index increased significantly with the hyperthermia and there was a close correlation between the cardiac index and the K-value. The LPL activity did not change significantly with changes in blood temperature, and the correlation between the LPL activity and the K-value was not significant. The hemodynamics has to be considered when attempting to discuss the intravenous lipid clearance rate.

Animals↗