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Biomedical subjects

T Sugai

Publications and source records attributed to T Sugai.

At least 73 records · Page 4Linked to original sources
PubMed1998

Osseointegrated implants and orbital defects: U.C.L.A. experience.

PURPOSE: A clinical study of 23 craniofacial implants placed in 8 irradiated and nonirradiated orbital detects was conducted over a 7-year period. MATERIAL AND METHODS: Implant-retained orbital prostheses were fabricated, implant success rate was determined, and the soft tissue responses were recorded at 6-month intervals. As a result of patient death, no data were gathered on three implants. A five-point scale was used to record the health of the peri-implant soft tissues and the patients were followed from 9 to 72 months. The unit of measure was a visit/site that was assigned for each instance an implant site was evaluated. Evaluations were conducted at 6-month intervals, and for the study period, there were 80 visit/sites. RESULTS: The study revealed that 42.5% (34/80) of the visit/sites demonstrated an absence of inflammation; 23.7% (19/80) of visit/sites demonstrated slight redness; 13.8% (11/80) demonstrated peri-implant red and moist tissues; 6.2% (5/80) demonstrated granulation tissue associated with the implants; and 13.8% (11/80) infection of the peri-implant soft tissues was noted. Implant success rate was 35% (7/20); implant success rate in the nonradiated patients was 37.5% (3/8) and the success rate for radiated patients was 33.3% (4/12). Implants placed in the orbital region demonstrated a high failure rate. Most implant failures occurred late as opposed to early in the study period. CONCLUSION: Orbital implants should be placed in patients who understand that long-term success rates may be low and require meticulous hygiene maintenance.

Adult↗
PubMed1998

Cellular injury score for multiple organ failure severity scoring system.

BACKGROUND: Cellular Injury Score (CIS) is an index of cellular injury, being calculated from three parameters of intracellular metabolism: arterial ketone body ratio, osmolality gap, and blood lactate. METHODS: The usefulness of CIS as a severity scoring system for patients with multiple organ failure was prospectively evaluated in 157 consecutive patients with MOF (58 survivors, 99 nonsurvivors). RESULTS: CISs in nonsurvivors were significantly higher compared with those in survivors throughout the clinical courses. CIS was significantly correlated with the number of failing organs and mortality rate. The optimal cutoff point of CIS from receiver operating characteristics curve analysis was 4 for the maximal value during the clinical course. The changes in CIS well reflected the severity of injury in survivors and nonsurvivors who died within 2 weeks. CONCLUSION: CIS could be a useful index for mortality risk prediction and is potentially applicable as a severity scoring system for individual patients with MOF.

3-Hydroxybutyric Acid↗
PubMed1998

High-performance liquid chromatography-electrospray tandem mass spectrometry for the measurement of 1-(3,4-dichlorobenzyl)-5-octylbiguanide in human serum.

1-(3,4-dichlorobenzyl)-5-octylbiguanide (OPB-2045) is a new biguanide antimicrobial agent currently in clinical use as a topical bactericidal antiseptic. A method combining high-performance liquid chromatography (HPLC) with electrospray ionization (triple and quadruple stage) tandem mass spectrometry (ESI-MS/MS) was developed to quantify OPB-2045 in human serum. Solid phase extraction was performed on 0.2 ml of sample to ensure a high level of sensitivity before HPLC-ESI-MS/MS analysis. The limit of quantitation for the method was set at 0.05 ng/ml. Intra-assay and interassay precision were less than 13.7%, with a deviation from the expected value of no greater than 10.5% at a concentration range of 0.05 ng/ml to 5 ng/ml. Decomposition of OPB-2045 in human serum did not occur after storage for 15 months at -20 degrees C, even after three repetitions of freezing and thawing. Application of this method was demonstrated in a pharmacokinetic study of OPB-2045 in healthy patient subjects after a single topical application of 5 g/L preparation of its liquid formulation.

Adult↗
PubMed1998

Correlation of histologic morphology and tumor stage with molecular genetic analysis using microdissection in gastric carcinomas.

Precise correlation of histomorphology with the results of molecular genetic analysis is difficult in gastric cancer tissue composed of intestinal and diffuse types. A novel microdissection procedure was applied to correlate p53 and APC allelic loss with histologic type and tumor stage (mucosal vs. invasive cancer) in formalin-fixed, paraffin-embedded specimens of 25 gastric cancers. In addition, mucosal and invasive lesions were dissected from each of 11 invasive gastric cancers to study progression, and allelic loss of the p53 and APC genes was assessed. The p53 gene underwent loss of heterozygosity (LOH) in 4 of 4 informative cases of intestinal-type gastric cancer with mucosal lesions associated with invasion. By contrast, no p53 LOH was found among 6 informative cases with mucosal cancer. LOH of the APC gene in both intestinal and diffuse types of cancer was detected in 4 of 7 and 5 of 6 informative cases, respectively. These data suggest that allelic deletion of the p53 gene in intestinal-type gastric carcinoma predicts the invasive potential of mucosal cancer, and that inactivation of the APC gene plays a role in the genetic tumorigenesis of both intestinal and diffuse types of gastric cancer. Microdissection can correlate genetic alterations with histologic morphology in gastric cancer.

Adenocarcinoma↗
PubMed1998

The first reported case of intestinal spirochaetosis in Japan.

A 65-year-old Japanese male consulted Ozuchi Prefectural Hospital (Iwate, Japan) on 19 January 1994 complaining of weight loss. Cecal mucosal biopsy material, which was stained with hematoxylin-eosin revealed a thick, basophilic fuzzy fringe covering the surface epithelium. Transmission and scanning electron microscopy observations demonstrated the presence of slightly wavy spirochaetes with tapered ends, which were attached to the surface epithelium of the colonic mucosa via one of these ends. The patient did not display any clinical symptoms of inflammatory bowel disease, and laboratory tests eliminated an immunodeficiency condition. Thus, in the present case, the intestinal spirochaetes appear to be harmless commensals. This paper presents the first reported case of intestinal spirochaetosis in Japan.

Aged↗
PubMed1997

Subdivisions of the guinea-pig accessory olfactory bulb revealed by the combined method with immunohistochemistry, electrophysiological, and optical recordings.

The presence of subgroups in vomeronasal sensory neurons has been known in various animals. To elucidate possible functional subdivisions in the guinea-pig accessory olfactory bulb, the combined studies with GTP-binding protein immunohistochemistry, electrophysiological and optical recordings were carried out. Gi2 alpha and Go alpha proteins were immunohistochemically localized, respectively, in the anterior and posterior regions of the vomeronasal nerve and glomerular layers, indicating that the guinea-pig accessory olfactory bulb receives at least two different inputs. This suggests that an anatomical boundary exists in these two layers. A mapping study of field potentials in sagittal slice preparations demonstrated that stimulation of the anterior vomeronasal nerve layer elicited field potentials with weak oscillatory responses exclusively in the anterior region of the external plexiform layer, whereas shocks to the posterior vomeronasal nerve layer provoked distinct oscillatory responses within the posterior one. The damping factors of oscillations in the anterior and posterior regions were 0.064+/-0.028 and 0.025+/-0.014, respectively. These electrophysiological results suggest that the accessory olfactory bulb consists of two functionally different subdivisions. Real-time optical imaging showed that anterior vomeronasal nerve layer shocks produced neural activity which spread horizontally from anterior to posterior only within the anterior region of the external plexiform and mitral cell layers, whereas shocks to the posterior vomeronasal nerve layer evoked periodic neural activity which spread horizontally from posterior to anterior only within the posterior region. Furthermore, the most posterior extent of the optical response evoked in the anterior region immediately adjoined the most anterior extent of that evoked in the posterior region. The maximal distance of signal propagation in the granule cell layer corresponded to that in the overlying external plexiform and mitral cell layers, indicating that the granule cell layer also has a similar boundary. Thus, these optical imaging studies not only demonstrated a precise boundary in each layer of the accessory olfactory bulb, which was positioned right beneath the boundary defined by GTP-binding protein immunohistochemistry, but also confirmed the observations from electrophysiological mapping that evoked field potentials are independently distributed in each of two subdivisions. The presence of the functional subdivision in each layer leads us to conclude that the accessory olfactory bulb in the guinea-pig is distinctly segregated into the anterior and posterior subdivisions, and to suggest that there are at least two different input output pathways in the vomeronasal system.

Action Potentials↗
PubMed1997

Hyperplastic (metaplastic) polyposis of the colorectum associated with adenomas and an adenocarcinoma.

Hyperplastic (metaplastic) polyposis associated with adenoma and adenocarcinoma of the colorectum is rare. We describe a 55-year-old man with hyperplastic polyposis associated with multiple adenomas and an adenocarcinoma who underwent total colectomy. We found at least 200 polyps in the surgical specimen. Nearly all of the polyps were hyperplastic, and some were adenomas. Furthermore, some hyperplastic polyps had adenomatous areas. This indicates the transformational sequence of a hyperplastic polyp to adenoma to adenocarcinoma.

Adenocarcinoma↗
PubMed1997

Efficacy and limitation of apheresis therapy in critical care.

Apheresis therapy such as plasma exchange and plasma adsorption has become therapeutic tools in critical care. The indications for apheresis therapy in ICU patients include fulminant hepatic failure, thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS), autoimmune disease, and sepsis. During the past 11 years, 150 patients with various kinds of critical illnesses were treated with apheresis therapy in our ICU, and the overall survival rate was 50%. Apheresis therapy is especially useful in the treatment of a patient with fulminant hepatic failure because liver transplantation is seldom performed in Japan; therefore, the patient should be treated with artificial liver support. When plasma exchange is performed on the critically ill, continuous hemodiafiltration should be performed simultaneously to overcome the adverse effects of plasma exchange such as hypernatremia, metabolic alkalosis, and abrupt changes in colloid osmotic pressure and to enhance the removal rate of the causative middle molecular weight substances of hepatic failure or hepatic coma.

Autoimmune Diseases↗
PubMed1996

DNA ploidy heterogeneity in early and advanced gastric cancers.

To evaluate the clinical utility of flow cytometric DNA analysis in gastric cancers, four or more fresh tissue specimens were systematically taken from gastric cancers in 127 consecutive patients including 68 early cancers. DNA ploidy and its variation in individual tumors were determined, and the data were related to clinicopathologic findings. DNA aneuploidy was detected frequently (84.3%) irrespective of tumor progression and correlated significantly with histologic grade (G1-2 [89.6%] vs. G3-4 [76.0%], P < 0.05). DNA ploidy heterogeneity was found in 67.7% of tumors and correlated with invasion depth (mucosa [40.5%] vs. submucosa-serosa [81.2%], P < 0.001), regional lymph node metastases (negative [58.4%] vs. positive [82.0%], P < 0.01), and stage grouping (I [58.8%] vs. II-IV [86.0%], P < 0.01). The maximum DNA index of a tumor correlated significantly with invasion depth (mucosa [1.16, median] vs. submucosa [1.82], P < 0.01) and lymph node metastases (negative [1.22] vs. positive [1.86], P < 0.001). The DNA index of the subpopulation that was the most widely distributed within the tumor was significantly associated with lymph node metastases (negative [1.14, median] vs. positive [1.44], P < 0.001) and histologic grade (G1-2 [1.37] vs. G3-4 [1.12], P < 0.001). More than 80% of the diploid and/or single aneuploid stemline tumors were stage I, whereas more than half of diploid and multiple aneuploid stemline tumors were stage IV. Variation in DNA ploidy rather than presence of DNA aneuploidy correlates best with progression of gastric cancer.

Aneuploidy↗
PubMed1996

DNA ploidy and S-phase fraction of neoplastic and non-neoplastic lesions of the human gallbladder.

Studies on the cell kinetics of the human gallbladder are difficult because of epithelial degeneration by bile. Using the epithelial isolation technique, however, we were able to determine the degree of degeneration and to examine the cell kinetics of gallbladder lesions in freshly resected surgical specimens. Normal and neoplastic epithelia were isolated nonenzymatically from freshly resected gallbladder. The nuclear DNA content and S-phase fraction were estimated in 110 patients with gallbladder lesions by flow cytometry (FCM). Normal tissues and all lesions except carcinomas were diploid. The S-phase fraction of gallstone cases was significantly higher (1.47 +/- 0.70%; mean +/- SD) than normal (0.79 +/- 0.39%) (P < 0.0006). All gallbladder carcinomas were multiploid, and their S-phase fraction was 11.63 +/- 3.65%. Cell renewal of normal gallbladder is low. In the gallstone cases, the S-phase fraction was increased, possibly correlated with carcinogenesis.

Adult↗
PubMed1996

Blood purification for prevention and treatment of multiple organ failure.

Blood purification has been applied conventionally as an artificial kidney or artificial liver in the management of patients with multiple organ failure (MOF), and most blood purifications have been performed intermittently. Recent advances in medical engineering made it possible to perform such blood purifications continuously (i. e., 24 hours a day, 7 days a week if necessary) even in critically ill patients. This modality is referred to as continuous renal replacement therapy (CRRT) or continuous blood purification (CBP). Among many kinds of CBP, continuous hemodiafiltration (CHDF) is most useful for management of MOF, as it can be performed without serious or hazardous side effects, and improvement can be expected with it. Recently, CHDF and polymyxin B immobilized endotoxin adsorption columns were used for the prevention or treatment of MOF, with the expectation that such therapy can be effective as a countermeasure against the pathophysiologic causes of MOF. Our data and that of others clearly indicate that continuous blood purification, such as with CHDF and endotoxin adsorption, can remove or decrease the blood levels of humoral mediators, including proinflammatory cytokines, and can improve tissue oxygenation, especially oxygen consumption (VO2) among critically ill patients including those with MOF. Blood purification is also useful in the careful management of fluid, electrolytes, and acid-base balance and for the removal of metabolic wastes. Blood purification is now considered to be one of the basic therapeutic tools of critical care, equal to nutritional support with total parenteral nutrition and respiratory support without a ventilator.

Critical Care↗
PubMed1996

Nasal defects and osseointegrated implants: UCLA experience.

A clinical study of 23 craniofacial implants placed in 11 nasal defects was conducted over a 7-year period. Implant-retained nasal prostheses were fabricated, implant success rate was determined, and the soft tissue responses were recorded at 6-month intervals. No data were gathered on two implants because of patient death. The implant success rate was 71.4% (15/21) but varied significantly by anatomic site. The implant success rate in the glabella was 0% (0/4), whereas the success rate in the anterior nasal floor was 88.1% (15/17). All implant failures occurred within the first year of loading. A five-point scale was used to record the health of the peri-implant soft tissues, and the patients were followed up from 6 to 74 months. The unit of measure was a visit/site, and a unit was assigned for each instance an implant site was evaluated. Evaluations were conducted at 6-month intervals for a total of 76 visit/sites for the study period. The results revealed that 85.5% (65/76) of the visit/sites demonstrated an absence of inflammation; 10.5% (8/76) of the visit/sites demonstrated slight redness; 1.3% (1/76) demonstrated peri-implant red and moist tissues; 2.6% (2/76) demonstrated granulation tissue associated with the implants; and 0% (0/76) demonstrated infection of the peri-implant soft tissues. Severe soft tissue reactions around implants placed in the anterior nasal floor are rare.

Aged↗
PubMed1996

Cell proliferation and p53 protein expressions in cutaneous epithelial neoplasms.

We investigated correlations between cell proliferation, p53 overexpression, and degree of malignancy in cutaneous epithelial neoplasms. One hundred and fourteen cases of epithelial neoplasms, including seborrheic keratosis (SEB), basal cell carcinomas (BCCs), solar keratosis (SK), Bowen's disease (BD), and squamous cell carcinomas (SCCs) were examined using argyrophilic nucleolar organizer region (AgNOR) staining. In addition, immunohistochemical analysis using the Ki-67 (MIB-1) and anti-p53 (DO-7) monoclonal antibodies was performed. The ratio of tumorous to normal cells according to AgNOR staining was defined as the AgNOR rate, and the ratio of tumorous to normal cells according to Ki-67 recognition was defined as the Ki-67 rate. SCC lesions showed the highest AgNOR rate among the investigated epithelial neoplasms, followed in order by BD, BCC, SK, and SEB lesions. The Ki-67 rate was highest in BD lesions, followed in order by SK, SCC, BCC, and SEB lesions. Expression of p53 protein was highest in SK lesions. SCC is generally considered to be the most malignant neoplasm, followed in order by BCC, BD, and SK. Thus, our results suggest that the Ki-67 rate and overexpression of p53 protein do not always reflect the degree of malignancy in neoplasms.

Adult↗
PubMed1996

Involvement of active cellular mechanisms on the disorganization of oral apparatus in amicronucleate cells in Tetrahymena thermophila.

Ciliated protozoa, a group of unicellular eukaryotes, have two kinds of nuclei, a macronucleus (somatic nucleus) and a micronucleus (germinal nucleus) in a single cell. We previously reported that amicronucleate cells of Tetrahymena thermophila induced by nocodazole gradually lost their oral apparatus (OA) and ciliary rows but that amacronucleate cells did not. Since the macronucleus is responsible for the gene expression in the vegetative phase, the effects of actinomycin D and cycloheximide on the disorganization of the OA in amicronucleate cells induced by nocodazole were investigated. These inhibitors prevented the disorganization of the OA in amicronucleate cells. Amicronucleate cells did not grow even in the medium supplemented with high concentration of Fe, Cu and folinic acid which allow cells to grow without formation of food vacuoles. The results suggest that the macronucleus in the amicronucleate cells plays an active role in the induction of disorganization of the OA and malfunctions of nutrient uptake from the cell surface and/or in the fundamental cell division mechanisms, resulting in the death of amicronucleate cells.

Animals↗
PubMed1996

Efficient lipase-catalyzed preparation of long-chain fatty acid esters of bile acids: biological activity and synthetic application of the products.

A highly regioselective (3-position) and efficient (quantitative yield) acylation of bile acids catalyzed by immobilized Candida antarctica lipase was established. Methyl cholate derivatives acylated with long-chain fatty acids (C12-C16) showed an inhibitory effect on the growth of some strains of Gram-positive and -negative bacteria (27-400 micrograms/ml). The anti-bacterial activity was slightly weaker than has been observed for methyl cholate, while the increased lipophilicity and lower melting points of the present derivatives are well suited for a potential germicide which would be safe and be topically applied. This enzyme-catalyzed transesterification is also demonstrated as an expeditious route to ursodeoxycholic acid, in respect of the regioselective introduction of acyl protecting groups on the hydroxyl groups of the intermediates. 7-Ketolithocholic acid, a known direct precursor of ursodeoxycholic acid, was obtained from cholic acid via chenodeoxycholic acid in a 46% yield and 9 steps.

Acylation↗
PubMed1996

A novel method for gene analysis of colorectal carcinomas using a crypt isolation technique.

Genetic studies of tumor masses require relatively pure populations of tumor cells. Substantial contamination by stromal cells, however, usually prevents detailed analysis of tumor cells. To improve the accuracy of gene analysis of tumor cells, a crypt isolation technique was introduced to separate neoplastic crypts from nonneoplastic stromal cells. Thirty-five specimens of colorectal carcinomas were examined for genetic alterations by using a PCR-based method combined with crypt isolation. K-ras gene mutations were detected by single-strand conformation polymorphism analysis. Allelic deletions of the p53 loci were estimated quantitatively based on loss of heterozygosity as determined by an automated DNA sequencer. Mutations of K-ras genes and allelic deletions at the p53 loci were detected in 18 (51%) and 15(68%) of 22 cases, respectively. The crypt isolation technique reduced ambiguity and provided quantitatively better results than conventional procedures. Evaluation of the allelic ratio for cases with loss of heterozygosity revealed that isolated neoplastic crypts were an almost pure population of tumor cells at the DNA level (>90%). Crypt isolation allowed sensitive and reliable analysis of the genetic alterations in colorectal carcinomas. This technique is applicable to biologic studies of colorectal tumorigenesis and genetic heterogeneities. To our knowledge, this is the first study in which genetic information has been derived directly from surgically resected primary colorectal carcinomas.

Alleles↗