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K Sugihara

Publications and source records attributed to K Sugihara.

At least 181 records · Page 10Linked to original sources
PubMed1992

Phospholipid asymmetry during erythrocyte deformation: maintenance of the unit membrane.

To assess the red blood cell (RBC) membrane's ability to maintain normal phospholipid orientation in the face of deforming stress, we examined RBC subjected to elliptical, tank-treading deformation. As determined by accessibility to phospholipase digestion and by labelling with fluorescamine, normal RBC are able to fully preserve their phospholipid asymmetry despite attaining over 96% of their maximal possible deformation. Phospholipid orientation is unchanged during deformation even for RBC that are ATP-depleted or vanadate-treated and for RBC that already have destabilized phospholipids due to treatment with t-butyl hydroperoxide. These data indicate that maintenance of phospholipid organization during marked deforming stress and tank-treading motion of the membrane is ascribable predominantly to the passive stabilizing effect of membrane proteins. This provides additional evidence for the concept of a unit membrane characterized by intimate associations between lipid and protein.

Cations↗
PubMed1992

An in vitro thymidine incorporation assay for human cancers: technical details revisited.

Among the choices of laboratory methods for in vitro testing of human tumor chemosensitivity, a thymidine incorporation assay (TIA) has been described. Advantages of a TIA over a colony-forming assay include greater probability of tumor growth, requirement for fewer tumor cells, less dependence on an absolute single-cell suspension, shorter time to completion, and the ability to measure up to three logs cell-kill. Specific technical details which are reported in the literature for performing a TIA are incomplete and/or conflicting between one laboratory and another. This paper reports details of methods designed to remove unbound 3[H]-thymidine from the agarose, standardize background counts, and determine optimal cell-plating densities, labeling time, optimal concentration of 3[H]-thymidine, and the best day after seeding cultures to add the 3[H]-thymidine. Care has been taken to compare the end point of drug sensitivity determinations following these methodologic changes, both among serial TIAs as well as with colony-forming assays.

Cisplatin↗
PubMed1992

Enhancement by monocytes of perforin production and its gene expression by human CD8+ T cells stimulated with interleukin-2.

Pore-forming protein (PFP) is an important effector molecule for cytotoxicity mediated by cytotoxic T cells and NK cells. In the present study, the effect of monocytes on PFP production by interleukin-2 (IL-2)-stimulated T lymphocytes was examined. Highly purified lymphocytes (> 99%) and monocytes (> 90%) were isolated by centrifugal elutriation from peripheral blood of healthy donors, and, CD4+ and CD8+ cells were isolated from the purified lymphocytes by using antibody-bound magnetic beads. PFP production was quantitated with a universal microspectrophotometer in combination with immunostaining using anti-PFP antibody. Monocytes did not produce any PFP. High levels of PFP production were observed in CD8+ cells, but not CD4+ cells after incubation for 4 days with IL-2. Addition of monocytes to cultures of CD8+ cells resulted in significant augmentation of PFP production after 3 days' stimulation with IL-2. Monokines (TNF alpha and IL-6) caused a significant increase in PFP production by IL-2-stimulated CD8+ cells. Northern blot analysis revealed that the PFP mRNA levels was enhanced by stimulation with IL-2, and that addition of monocytes to cultures of CD8+ cells plus IL-2 augmented their PFP mRNA expression. These observations suggest that monocytes are important in in situ regulation of the CD8+ T cell-mediated cytotoxic response through production of PFP.

Adult↗
PubMed1992

Endometrial metaplasia associated with endometrial carcinoma.

OBJECTIVE: To clarify the relationship of metaplasia to endometrial carcinoma. METHODS: Between 1984-1990, 73 cases of stage I-II endometrial carcinoma treated initially by hysterectomy were reviewed histologically. The metaplasias were classified as squamous, syncytial papillary, ciliated-cell, eosinophilic, mucinous, clear-cell, or hobnail. We assessed the histologic type and grade of the carcinoma, depth of myometrial invasion, presence or absence of lymph-vascular space invasion, and presence or absence of lymph node metastases. RESULTS: Forty of 73 patients (55%) had one or more areas of metaplasia in the endometrium adjacent to the carcinoma. Ciliated-cell metaplasia (28 of 73; 38%) was the most common type encountered. Women with both endometrial carcinoma and metaplasia were significantly younger than those with carcinoma without metaplasia (P < .05). Compared with carcinomas without metaplasia, those with metaplasia were well differentiated (P < .01) and lacked myometrial invasion (P < .01) and pelvic lymph node metastases (P < .05). The presence of metaplasia was also significantly correlated with the presence of endometrial hyperplasia (P < .01). CONCLUSION: In endometrial carcinomas, the presence of endometrial metaplasia suggests a favorable prognosis.

Adult↗
PubMed1992

[Therapeutic modality for esophago-gastric varices analyzed by endoscopic ultrasonography].

For 64 cases with portal hypertensive disease, we investigated the intramural and extramural structure of the stomach and esophagus by endoscopic ultrasonography (EUS). Variously developed intra- or extra-mural vascular structures had a relationship to the endoscopic variceal form, and the communicating (inflow) vessels to varices were found in 35 of 50 primary treated cases (70%). We classified the esophago-gastric varices into three types according to the vascular structure, such as the esophageal type, the esophago-gastric type and the solitary gastric type. From the analyses of these collateral structures, we should select a treatment as follows. In the esophageal type which has a few inflow vessels, it is easy to eliminate the varices by obturating the inflow vessels by endoscopic injection sclerotherapy (EIS). In the esophago-gastric type, which has many enlarged inflow vessels, the Hassab operation is effective to devascularize extramural inflow vessels, and the combination of EIS is necessary to sclerous the intramural varices. In the solitary gastric type which is a part of the downward porto-systemic shunt, Hassab operation is recommended to prevent the rupture of varices for the subtype with intramural running vessels, but conservative therapy is enough for the subtype without intramural running vessel.

Collateral Circulation↗
PubMed1992

[Methionine-deprived amino acid solution-induced biochemical modulation of 5-FU and augmentation of the antitumor activity].

A randomized study of the effects of methionine-deprived amino acid solution (AO-90) on the metabolism of 5-FU was performed in patients with advanced gastric or colorectal cancers. Continuous intravenous hyperalimentation with either AO-90 or conventional amino acid solution (control group) in combination with 5-FU was performed for 7 days preoperatively under the fasting condition. The administration of AO-90 showed a decreased level of serum methionine and resulted in the subsequent increased tendency in the intratumorous levels of both folic acid and methylene tetrahydrofolate compared to those of the control group. In the AO-90 group, the inhibition rate of thymidilate synthase in the tumor was significantly higher than that of the control group. These results indicate that AO-90 plays an important role in the metabolism of 5-FU and seems to contribute to the increased antitumor effect of 5-FU as a biochemical modulator.

Amino Acids↗
PubMed1991

Preservation of urine voiding and sexual function after rectal cancer surgery.

In order to decrease the urinary and sexual morbidity which follows radical pelvic lymphadenectomy for rectal cancer, we began selective preservation of the pelvic autonomic nerves. Between 1985 and 1987, 134 patients with rectal cancer underwent a curative resection (52 abdominoperineal resections, 82 sphincter-saving resections) with extended pelvic lymphadenectomy and selective pelvic autonomic nerve preservation (PANP). PANP was classified into five degrees depending on the extent of pelvic dissection. First-degree PANP indicates complete preservation of the nerves; second-degree PANP indicates destruction of the hypogastric plexus: third-degree PANP indicates partial preservation of the pelvic autonomic plexus; fourth-degree PANP indicates bilateral or unilateral preservation of only the fourth pelvic parasympathetic nerve; and fifth-degree PANP indicates complete destruction of the pelvic autonomic nerves. Most patients with first-degree PANP were able to spontaneously void 7-10 days following the operation. However, 78 percent (28/36) of patients with fifth-degree PANP had not regained bladder sensation by the third postoperative week and were discharged with an indwelling catheter; 58 percent (21/36) had not regained bladder sensation by the 60th postoperative day. The cystometric data indicate a progressive decline in bladder sensation and function with increasingly extensive pelvic dissection. However, preservation of only the fourth parasympathetic nerve (fourth-degree PANP) resulted in partial sparing of bladder sensation and voiding function. Evaluation of sexual function in males under 60 years of age revealed that only 31 percent (12/39) recovered erectile function and only 19 percent (6/39) recovered normal ejaculatory function in the first postoperative year. Most of these patients had complete preservation of their pelvic autonomic plexus (i.e., first-degree PANP). Four patients with partial PANP have recovered erectile function. Complete PANP is the best way to prevent urinary and sexual morbidity after rectal resection. The opposing goals of maximizing the chance for cure and minimizing morbidity must be individualized and balanced in each patient. Our data demonstrate that it is now possible to perform radical pelvic lymphadenectomy in the majority of patients with advanced rectal cancer with a minimum of voiding dysfunction. Preservation of sexual function in males is more difficult and depends on complete PANP and, as such, should be restricted to the group of patients with Dukes' A and B carcinomas.

Adult↗
PubMed1991

Interleukin-4 downregulates interleukin-6 production by human alveolar macrophages at protein and mRNA levels.

Effects of interleukin-4 (IL-4) on IL-6 production by human alveolar macrophages (AM) obtained by bronchoalveolar lavage from healthy donors was examined at the protein and gene levels. IL-6 production was quantitated by enzyme immunoassay (EIA) and bioassay using the IL-6 dependent murine hybridoma cell line MH60.BSF2. Results showed that when activated with LPS, AM released significantly more biologically active IL-6 than blood monocytes. Human rIL-4 significantly suppressed IL-6 production by AM and monocytes stimulated with LPS. Northern blot analysis revealed that IL-4 reduced the expression of IL-6 mRNA in LPS-stimulated AM and monocytes. The inhibitory effect was most pronounced when IL-4 was added with LPS or within the first 4 hr after LPS to AM or monocytes. The suppressive effect of IL-4 was completely neutralized by pretreatment with anti-IL-4 antibody. IL-4 also showed a suppressive effect on IL-6 production by macrophages generated in vitro by maturation of blood monocytes with granulocyte-macrophage colony stimulating factor (GM-CSF). These observations suggest that IL-4 may play a critical role in in situ regulation of immune responses through suppression of IL-6 production.

Adult↗
PubMed1991

Adjuvant hepatic intra-arterial chemotherapy after potentially curative hepatectomy for liver metastases from colorectal cancer: a pilot study.

The site most at risk of recurrence after hepatectomy is the remaining liver. Therefore a study was conducted of the use of hepatic intra-arterial and oral chemotherapy for colorectal metastases to prevent intrahepatic recurrence. Our regimen consisted of intra-arterial 5-fluorouracil (5-FU), mitomycin C (MMC) and oral 1-hexylcarbamoyl-5-fluorouracil (HCFU). Sixteen patients were treated. Median total dose of 5-FU was 8.1 g, MMC was 43 mg, and HCFU was 54 g, respectively. Median follow-up period was 21 months. The recurrence rate of the remaining liver was 31%. With respect to the number of hepatic metastases, there was no recurrence in patients with a single deposit. On the other hand, the intrahepatic recurrence rate of patients with multiple deposits was 45%. Of six patients with more than five hepatic deposits, however, only one patient had developed recurrent disease in the liver. Chemical sclerosing cholangitis (19%) was the most serious complication. Consequently, we propose that a prospective randomized trial should be carried out to establish the effects of this type of adjuvant chemotherapy to reduce possible recurrences in the remaining liver.

Adult↗
PubMed1991

[Effect of intramuscular pethidine on cardiovascular and endocrine functions in dogs].

Effect of intramuscular administration of pethidine on cardiovascular and endocrine functions were studied as judged by cardiac variables and plasma hormone levels in dogs under 1% enflurane anesthesia. Twenty-four mongrel dogs were divided into three groups. Seven dogs receiving physiological saline only served as the control group. Pethidine 2 mg.kg-1 was given to each of nine dogs (2 mg.kg-1 group), and in the remaining eight dogs 6 mg.kg-1 of the drug was administered (6 mg.kg-1 group). Swan-Ganz catheter was used for measurement of cardiac variables such as central venous pressure, cardiac output, pulmonary capillary wedge pressure and etc. In the 6 mg.kg-1 group, mean arterial pressure, heart rate and cardiac index decreased significantly, but no significant changes in cardiac variables were observed in the 2 mg.kg-1 group. Plasma levels of cortisol and ACTH decreased significantly in the 6 mg.kg-1 group and tended to decrease in the 2 mg.kg-1 group. No significant changes were observed in plasma levels of catecholamines, aldosterone, renin activity, antidiuretic hormone and insulin in both groups. These findings suggest that in dogs under 1% enflurane anesthesia intramuscular administration of pethidine 6 mg.kg-1 would depress cardiac functions and intramuscular administration of pethidine more than 2 mg.kg-1 would also depress adrenocortical function.

Anesthesia, Inhalation↗
PubMed1990

Heterotopic central neural tissue of the tongue.

A rare case is reported of a pedunculated tumor containing heterotopic central neural tissue in the tongue of a 3-month-old girl. The lesion was located near the foramen caecum and was composed of glial cells, ependymal cells, a small number of neuronal cells and a relatively thick peripheral nerve.

Cell Nucleus↗
PubMed1990

Eosinophilic granuloma showing rapid regression. Report of a mandibular case with application of a modified PNA staining method for demonstration of Langerhans-type histiocytes.

A mandibular eosinophilic granuloma in a 16-year-old male is reported. This case showed rapid regression, which was clearly demonstrated by histopathological examinations of both preoperative biopsy and surgical materials. Transformation from an eosinophilic granuloma to a xanthomatous granuloma with multinucleated giant cells was observed after only 26 days. Special staining of paraffin sections with peanut agglutinin (PNA) and use of electron microscopy showed that the main component of the lesion in the biopsy material was Langerhans-type histiocytes. These cells had disappeared from the lesion by the time of the operation. At the same time, the number of infiltrating eosinophils was also markedly reduced. It seems appropriate to consider that the rapid regression of this disease was correlated with the rapid reduction in the number of Langerhans-type histiocytes appearing in the granulomatous foci, as well as the number of infiltrating eosinophils.

Adolescent↗
PubMed1990

Molluscum contagiosum associated with AIDS: a case report with ultrastructural study.

The clinical features of perioral molluscum contagiosum in a patient with the acquired immunodeficiency syndrome are described. Light microscopy and thin section electron microscopy revealed epidermal cells in different stages of degeneration showing two types of cytoplasmic inclusions. The basement membrane exhibited discontinuities and multiple laminations which may be a response to viral-induced cytotoxic effects.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Negative staining EM for the detection of Epstein-Barr virus in oral hairy leukoplakia.

The performance of two different EM techniques applied for the detection of Epstein-Barr Virus (EBV) in oral hairy leukoplakia (HL) was assessed, i.e. the conventional two-step method of negative staining (CNS) and negative staining after Airfuge enrichment (ANS). Scrape specimens from the lateral borders of tongue of 66 HIV-positive patients with or without HL, of 3 patients with infectious mononucleosis and of 10 HIV-negative patients were evaluated. While CNS resulted in virus detection only in 25% of clinically diagnosed HL cases, EBV was detected by ANS in 85% of clinically suspected cases of HL. Scrape specimens of individuals negative for HIV were negative in EM while 2 of 3 mononucleosis patients were positive without clinical evidence for HL. Due to this high sensitivity the method of negative staining after Airfuge enrichment appears to be useful in the diagnosis of HL. The finding of EBV in clinically normal oral mucosa in HIV-seropositive individuals is interesting and indicates that EBV expression may precede the clinical appearance of HL.

Adult↗
PubMed1990

Isolation of Staphylococcus species from the tonsils of healthy cattle and phage patterns of isolates.

Staphylococci were found in the tonsils of 121 (75.2%) of 161 cattle. There were 15 different species, 10 belonging to novobiocin-sensitive species. The most predominant species was S. simulans (79.3% of the 121 carriers), followed by S. aureus (20.7%), S. chromogenes (10.7%) and S. epidermidis (8.3%). The other 11 species were present in 0.8 to 5.8%. Twenty-six unidentifiable isolates were isolated from 26 (21.5%) carriers. Sixty-two (51.2%) of the 121 carriers yielded two to five Staphylococcus species together while only one species could be found in each of the other 59 (48.8%). Combinations of S. simulans and other species were most frequently encountered in 50 (41.3%) of the 121 carriers. Twenty-four (96.0%) out of 25 S. aureus isolates, 3 (42.9%) of 7 S. hyicus isolates and 45 (25.4%) of 177 coagulase-negative staphylococci (13 species and unidentifiable isolates) isolates were phage typable. Most of S. aureus isolates were lysed by bovine phages 119 (n = 16) or 116 (n = 5). Thirty-three (25.4%) of 45 coagulase-negative staphylococci typable isolates with Pulverer's phage set showed the phage pattern ph5/ph9/ph10/ph12/ph13/U4/U14/U16/++ +U20/U46. The tonsils of cattle thus appear to be a suitable environment for Staphylococcus species, particularly novobiocin-sensitive species.

Animals↗
PubMed1990

Leucine dehydrogenase from Corynebacterium pseudodiphtheriticum: purification and characterization.

Leucine dehydrogenase [EC 1.4.1.9] was purified to homogeneity from Corynebacterium pseudodiphtheriticum ICR 2210. The enzyme consisted of a single polypeptide with a molecular weight of about 34,000. Stepwise Edman degradation provided the N-terminal sequence of the first 24 amino acids, and carboxypeptidase Y digestion provided the C-terminal sequence of the last 2 amino acids. Although the enzyme catalyzed the reversible deamination of various branched-chain L-amino acids, L-valine was the best substrate for oxidative deamination at pH 10.9 and the saturated concentration. The enzyme, however, had higher reactivity for L-leucine, and the kcat/Km value for L-leucine was higher than that for L-valine. The enzyme required NAD+ as a natural coenzyme. The NAD+ analogs 3-acetylpyridine-NAD+ and deamino-NAD+ were much better coenzymes than NAD+. The enzyme activity was significantly reduced by sulfhydryl reagents and pyridoxal 5'-phosphate. D-Enantiomers of the substrate amino acids competitively inhibited the oxidation of L-valine.

Amino Acid Oxidoreductases↗