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Biomedical subjects

T Shigematsu

Publications and source records attributed to T Shigematsu.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Evaluation of nutritional status of patients on continuous ambulatory peritoneal dialysis (CAPD) by dual photon energy X-ray absorptiometry (DEXA)].

Malnutrition is a serious complication in patients on long-term CAPD treatment. Accordingly, quantitative evaluation of nutritional status is a critical issue. This study aimed to assess nutritional status by dual photon energy x-ray absorptiometry (DEXA) in CAPD patients. Total lean body mass (D-TBM), right arm lean mass (D-RAM) and body fat percent (D-% FAT) measured by DEXA were compared with mid-arm muscle circumference (MAMC) and body fat percent (AP-% FAT) measured by anthropometrics (AP) in 51 CAPD patients. The subjects were stratified into groups by gender, age, duration on CAPD, and diabetes mellitus or non-diabetes. There was significant correlation between D-TBM, D-RAM and MAMC (r = 0.519, p = 0.001, r = 0.545, p = 0.001) or D-% FAT and AP-% FAT (r = 0.763, p = 0.0001). However, in the groups of females with over 50 years and over 48 months of dialysis duration, there was no correlation between D-TBM, D-RAM and MAMC. The DEXA method is useful in the quantitative evaluation of nutritional status of dialysis patients serially.

Absorptiometry, Photon↗
PubMed1996

Long-term stability following surgical orthodontic treatment of mandibular prognathisms: investigation by means of lateral X-ray cephalogram.

The purpose of this study was to investigate the long-term stability of jaw relations and occlusion following surgical orthodontic treatment of mandibular prognathisms and skeletal openbites. Subjects consisted of fifteen adult patients. Ten patients underwent the sagittal split ramus osteotomy (SSRO) of the mandible and five patients underwent two jaw surgery (Le Fort I osteotomy of the maxilla and SSRO of the mandible). They were observed over five years after the end of active treatment, and lateral X-ray cephalograms were taken at each stage. In the SSRO group, pogonion was retrograded an average of 8.7mm due to the operation and it was further replaced 0.4mm backward after the end of active treatment. Although the vertical distance between nasion and menton decreased 2.9mm between the operative period, it increased 1.8mm after the end of active treatment. On the other hand, in the two jaw surgery group, point A was advanced 4.0mm forward and < SNA increased 3.1 degrees between the operative period. Pogonion was retrograded 11.4mm between the same period, but moved 0.7mm forward after the end of active treatment. A comparison of the osteosynthesis methods revealed that pogonion in the wiring group was retrograded 8.3mm backward between the operative period, but moved 2.1mm forward during the postsurgical orthodontic treatment. Pogonion in the rigid group was retrograded 12.6mm backward between the operative period, but moved 1.6mm forward during the postsurgical orthodontic treatment. However, both groups were stabilized completely after the end of active treatment. A comparison of the differences in the orthodontic treatment method revealed that < Ul-SN in the extraction group inclined 8.3 degrees lingually during presurgical orthodontic treatment, but it tipped 7.0 degrees labially during the postsurgical orthodontic treatment and inclined 3.4 degrees lingually after the end of active treatment. < Ul-SN in the non-extraction group inclined 5.5 degrees lingually during the presurgical orthodontic treatment, but it tipped 2.0 degrees labially during the postsurgical orthodontic treatment and inclined 1.9 degrees lingually after the end of active treatment.

Adult↗
PubMed1996

Functioning survival rate of fixtures and superstructures of osseointegrated implants: ten years of progress in Tokyo Dental College Hospital (second report).

Osseointegrated implant bridges (OIB) have shown excellent results in the majority of cases. Since 1983, 1,022 fixtures has been applied to 241 superstructures in Tokyo Dental College Hospital. The aim of present study was to examine their functioning survival rate during recent ten years. The functioning survival rate of the superstructure of OIB has been almost 100% in both maxilla and mandible. Although 13.0% of these fixtures had to be removed in maxillary complete cases, only 3.3% of fixtures were removed in other cases. In maxillary complete cases, the functioning survival rate of OIB fixtures gradually decreases from 91% to 74% (91%, less than 3 years; 84%, between 3 and 7 years; 74%, more than 7 years), but it remained at about 97% for all periods in other cases. Apparently, the functioning survival rate of OIB fixture is generally determined within the period of one year, so almost the same rate is maintained thereafter. It is suggested that if more fixture numbers in the superstructure were applied to maxillary complete cases, the functional survival rate might improve.

Adolescent↗
PubMed1995

Modulation of collagen synthesis and cell proliferation by retinoids in human skin fibroblasts.

The effect of the retinoids, 13-cis-retinoic acid (-RA), etretinate and all-trans-RA on collagen synthesis and cell proliferation of human skin fibroblasts was studied. These compounds all inhibited collagen synthesis at concentrations between 10(-8) and 10(-5) M after 48 h treatments. The inhibitory effect of 13-cis-RA was the most pronounced. Both all-trans-RA and etretinate inhibited DNA synthesis, to 60% and 53% of control value, respectively, at 10(-5) M. In contrast, 13-cis-RA did not show any significant effect on DNA synthesis at the concentrations used. 13-cis-RA appears to be a unique drug showing a pronounced inhibitor effect on collagen synthesis without affecting DNA synthesis and may prove a useful tool for the treatment of fibrotic diseases.

Adult↗
PubMed1995

Potential role of IGF-1 in parathyroid hormone-related renal growth induced by high protein diet in uninephrectomized rats.

Recent studies indicate that parathyroidectomy (PTX) prevents the progression of kidney damage due to high protein diet in the subtotal nephrectomized rat model of chronic renal failure. Associated with this protection, the difference in the renal "compensatory" growth induced by high (HPr) as compared to normal protein diet (NPr) is completely abolished by PTX. To understand the physiological mechanism responsible for this protection, the changes in both circulating level and kidney content of IGF-1, a growth factor capable of influencing renal "compensatory" growth, was analyzed after unilateral nephrectomy (UNX). In UNX rats, HPr as compared to NPr diet given for five days significantly increased the kidney/body weight ratio (0.48 +/- 0.01%, N = 11 vs. 0.44 +/- 0.01%, N = 11, P < 0.005) and the plasma level of IGF-1 (365 +/- 10 ng/ml vs. 306 +/- 10 ng/ml, P < 0.001). In UNX rats fed HPr, PTX completely abolished the renal "compensatory" growth (0.38 +/- 0.02%, N = 7, P < 0.001) and the increased plasma level of IGF-1 (246 +/- 14 ng/ml, N = 7, P < 0.001). In PTX-UNX rats treated with physiological doses of 1,25-dihydroxyvitamin D3 which nearly normalized the calcemia, the renal growth and the increased plasma level of IGF-1 induced by HPr were restored towards those recorded in SHAM-UNX rats fed the HPr diet. Similar effects were observed in PTX-UNX rats in which the plasma calcium concentration was increased by the chronic administration of a retinoid derivative, used as an agent where the calcemic effect is essentially mediated by a stimulation of bone resorption.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗
PubMed1995

Current issues of continuous ambulatory peritoneal dialysis.

This paper concerns the overall median technical survival of chronic continuous ambulatory peritoneal dialysis (CAPD) patients and treatment in the 6 years since the commencement of CAPD at the Jikei University Hospital. Diabetic end-stage renal disease (ESRD) patients showed 5 years' survival, apparently shorter than that of nondiabetic ESRD which was 7 years. From this fact, the question of whether CAPD is the best dialytic option in diabetic ESRD should be reevaluated. Although a remarkable reduction in the incidence of peritonitis has been seen, generally ranging from 1 episode/40 patient months to 60 patient months or more in Japan, one serious issue still to be addressed is exit site/skin tunnel infection. The incidence is around 1 episode/30 patient months in our hospital. Discovering how to prevent this infection is a matter of some urgency. Peritoneal dialysis is a limiting dialytic modality as far as the biomembrane used. Although the precise mechanisms deteriorating the peritoneal function are still obscure, the treatment of sclerosing encapsulated peritonitis is also an urgent matter. Regarding bone disease and metastatic calcification, adynamic bone disease is frequently observed in ESRD patients: However, the pathogenesis of this morbidity has not been clarified. Treatment of extraosseous calcification in vessels and periarticular, and visceral organs should be developed. New dialytic alternatives to glucose and/or lactate-based solutions have been under experimental study. Until a new solution is delivered commercially, CAPD will remain a transient therapy. Our large study of CAPD patients revealed that 26% were malnourished. The biochemical parameters, amount of daily protein intake, and KT/V did not show significant differences between those patients identified as well nourished versus malnourished. The causes of malnutrition should be considered from other points of view such as endocrinological circumstances. Newer therapeutic approaches to malnutrition are also required.

Adult↗
PubMed1995

[Relative hypoparathyroidism associated with CAPD treatment using normo-calcemic (3.5mEq/1) dialysate: an approach from transperitoneal calcium balance].

We investigated factors affecting net transperitoneal calcium balance (Ca-BL) and the level of parathyroid hormone in relation to stepwise changes in serum calcium, by short PET (peritoneal equibrium test during 240 min: using 2000 ml of 2.5% dextrose dialysate containing 1.75 mmol/L Ca) in uremic patients undergoing stable CAPD. We calculated Ca-BL (mg/effluent/PET) of 244 effluents obtained from 90 patients receiving calcium carbonate as a phosphate binder without vitamin D supplementation. Their serum calcium level corrected with albumin (cSCa), alkaline phosphatase activity (ALP) and intact-PTH level was 9.7 +/- 0.9 mg/dl, 236 +/- 83 mIU/ml and 153.0 +/- 172.4 pg/ml, respectively. We proposed two statistic significant regression lines between Ca-BL and total drainage effluent volume (Ca-BL = 133X - 0.056: r = 0.981, P < 0.001), cSCa (Ca-BL = -12.9X + 123.6: r = 0.941, P < 0.01). Total drainage volume (TDV) and cSCa were two major factors affecting Ca-BL. A TDV level of 2430 ml/240 min-PET or more was required for positive Ca-BL in cases with 9.5-10.0 mg/dl of cSCa, using this linear regression analysis. A cSCa level of 9.6 mg/dl or more was also required for positive Ca-BL in cases with 2400-2600 ml/240min-PET. We also proposed a significant linear regression line between the intact-PTH level and cSCa (i-PTH = -90.5X + 1015.8, r = 0.973, P < 0.01). This line suggest that 200 pg/ml of intact PTH was obtained by 9.0 mg/dl or less of cSCa level in 90 CAPD uremic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Suprahyoid myotomy from an extraoral approach.

On several occasions, the suprahyoid muscles have been detached from the lingual surface of the mandible at the same time as sagittal split advancement procedures in treatment of class II malocclusion and/or open bite patients. We usually perform suprahyoid myotomy through a degloving type incision (the Steinhauser technique) when genioplasty is planned. However, sometimes genioplasty is not necessary. In such cases, we perform the myotomy through a small submental skin incision. This method has some advantages: 1. Surgical stress is less and operating time is shorter than the Steinhauser method. 2. The risk of detachment of the major portion of the genioglossus muscles is lower than in the Allison method. We present this procedure of suprahyoid myotomy carried out from an external approach.

Humans↗
PubMed1994

Inhibition of collagen hydroxylation by lithospermic acid magnesium salt, a novel compound isolated from Salviae miltiorrhizae Radix.

We have screened several chinese medicinal herbs for the presence of antifibrotic agents. An aqueous extract of Salviae miltorrhizae Radix was found to inhibit collagen secretion by human skin fibroblasts without affecting DNA or noncollagen protein synthesis. We have subsequently purified the material exhibiting the inhibitory activity and identified it as magnesium lithospermate. From its chemical structure this compound was predicted to be an inhibitor of the post-translational modifying enzymes prolyl and lysyl hydroxylases in collagen biosynthesis. Accordingly, it decreased the extent of prolyl and lysyl hydroxylations in collagen by approx. 50%. Added to cell extracts it inhibited both prolyl and lysyl hydroxylase activities, but only lysyl hydroxylase activity when added to intact cells. Oral administration of this compound to mice led to a significant reduction of prolyl hydroxylation in newly-synthesized skin collagen. This naturally-occurring compound thus offers a potential means for treating fibrotic diseases, such as systemic scleroderma and keloid.

Animals↗
PubMed1994

Elastase gene expression in non-elastase-producing Pseudomonas aeruginosa strains using novel shuttle vector systems.

In order to determine whether non-elastase-producing strains of Pseudomonas aeruginosa such as N-10, PA103 and IFO3080 can express foreign elastase genes, we introduced elastase genes from P. aeruginosa IFO3455 (elastase-producing) as well as from PA103 and N-10 into non-elastase-producing P. aeruginosa strains. Results suggested that gene expression, secretion, and precursor processing systems of elastase were essentially normal in P. aeruginosa N-10 and IFO3080. Our studies using various elastase genes showed that both the elastase structural gene and 5'-upstream regions of P. aeruginosa PA103 were also normal. This was confirmed by the finding that P. aeruginosa N-10 and IFO3080 which carry the PA103 elastase gene produced elastase. Several deleted or chimeric genes were constructed using the 5'-upstream regions of elastase genes from P. aeruginosa N-10 or PA103 and studies of expression revealed that two individual DNA bases seem to be important in suppressing P. aeruginosa N-10 elastase gene expression. Possible reasons for the lack of elastase expression in these non-elastase-producing strains are discussed.

Base Sequence↗
PubMed1994

Hepatitis B surface antigen, hepatitis C virus antibody, body mass index, and alcohol drinking among workers with elevated serum alanine aminotransferase.

METHODS: We conducted a case-control study on liver diseases among Japanese workers to examine associations between elevated serum alanine aminotransferase (alanine aminotransferase value > or = 50 IU/liter) and selected factors such as hepatitis B surface antigen positive, hepatitis C virus antibody positive, body mass index, and alcohol drinking. Out of 3,738 workers (1,477 males and 2,261 females) in a supermarket chain, 91 workers with an elevated serum alanine aminotransferase value (> or = 50 IU/liter) were classified as cases and 182 workers with normal serum alanine aminotransferase value and without an episode of blood transfusion were randomly selected as controls. RESULTS: Prevalence rates of hepatitis B surface antigen positive and hepatitis C virus antibody positive were 4.4 and 23.1% among the overall cases, 2.9 and 11.8% among the cases with 100 > alanine aminotransferase value > or = 50, and 8.7 and 56.5% among the cases with alanine aminotransferase value > or = 100. A logistic regression analysis was conducted. Odds ratios were 4.94 for hepatitis B surface antigen positive (P < 0.05) and 77.19 for hepatitis C virus antibody positive (P < 0.001). Odds ratios for body mass index increased with increasing body mass index values; 3.32 for 26 > body mass index > or = 24 (P < 0.01) and 5.03 for body mass index > or = 26 (P < 0.001). No increased risk was observed among regular drinkers of less than 27 g/day of ethanol (odds ratio is 0.23) or of 27-53 g/day of ethanol (odds ratio is 0.47). A slightly increased odds ratio of 1.35 was observed among regular drinkers of 54-81 g/day of ethanol, but this was not statistically significant. CONCLUSIONS: Our results suggest that hepatitis C virus and high body mass index are predominant factors in elevated serum alanine aminotransferase levels among Japanese workers, while alcohol drinking is a minor factor.

Adult↗
PubMed1994

Nasal intubation with Bullard laryngoscope: a useful approach for difficult airways.

Since the original technique using the Bullard laryngoscope requires considerable practice to be reliable, we have developed an easier method with a directional-tip endotracheal tube through the nostril. We first examined the feasibility of our method in patients with or without difficult airways. All 26 patients with difficult airways were successfully tracheally intubated with our method, and times for visualization and intubation were not different from those in 10 patients with normal airways. We further examined the direction of the tips of endotracheal tubes through the nostril in 128 patients with normal airways using four combinations of two kinds of both laryngoscopes (Bullard and Macintosh) and endotracheal tubes (directional-tip tube: Endotrol, Mallinckrodt Laboratories, Athlone, Ireland; or straight distal-end tube: Blue Line, Portex Ltd., Hythe Kent, United Kingdom). We found that a combination of the Bullard laryngoscope and the Endotrol tube had a higher probability of accessing the center of the glottis than the others. In conclusion, nasal insertion of a directional-tip tube assisted by the Bullard laryngoscope is an assured and prompt procedure for intubating the tracheas of patients with difficult airways.

Adult↗
PubMed1994

Vascular endothelial dysfunction in patients on regular dialysis treatment.

Circulating plasma immunoreactive thrombomodulin (i-TM) reflects the injury of vascular endothelium, and desmopressin stimulates tissue plasminogen activator (tPA) release from endothelium. Therefore, in order to estimate the damage of vascular endothelium in patients on regular dialysis treatment (RDT), we studied 1) basal plasma levels of i-TM and 2) a capability to release tPA by desmopressin. The basal plasma i-TM levels of the patients (n = 23) were significantly higher than those of the normal controls (p < 0.001). The basal plasma tPA levels of the patients (n = 8) were significantly lower than those of the controls (p < 0.05). The maximum increments of tPA from the basal levels by desmopressin in the patients were significantly reduced compared to those of the controls (p < 0.001). There was a significant inverse correlation in those cases between the maximum increments of tPA and the basal plasma levels of i-TM (p < 0.05, r = -0.75). The results actually suggested that there is a vascular endothelial damage in patients on RDT.

Adult↗
PubMed1993

Metastatic adenocarcinoma to the uterine cervix from gastric cancer. A clinicopathologic analysis of 16 cases.

BACKGROUND: Metastatic adenocarcinoma to the uterine cervix from gastric cancer is rare, and the clinicopathologic features of this metastasis are unclear. METHODS: A clinicopathologic review of 16 patients with metastatic adenocarcinoma to the uterine cervix from gastric cancer was performed. RESULTS: The ages of the patients ranged from 29 to 57 years, and 81.3% of the patients were premenopausal. Nine of the patients had undergone gastrectomy previously. In 11 patients the histologic type of the gastric cancer was poorly differentiated adenocarcinoma and, in 5 patients, signet ring cell carcinoma. The cervical metastasis was diagnosed 11-121 months (mean, 57.5 months) after the diagnosis of the gastric cancer in 10 of the patients. In six patients, the cervical metastasis was discovered synchronously or before the diagnosis of the gastric cancer. The colposcopic findings were normal in 57.1%, but 56.3% had abnormal cervical smears. In all patients, tumor cells were present in the dilated lymphatics of the cervix. Metastases to the uterine body and bilateral ovaries were common, and half of the patients had metastases to the paraaortic lymph nodes. Extirpation of the cervix was performed in six patients. The prognosis was poor, regardless of the treatment method. CONCLUSIONS: The route of metastasis to the cervix is surmised to be retrograde lymphatic, and this extension is often slow. Periodic gynecologic examinations should be performed indefinitely for premenopausal female patients with advanced gastric cancer.

Adenocarcinoma↗
PubMed1993

Effects of the bisphosphonate tiludronate on bone resorption, calcium balance, and bone mineral density.

Bone resorption inhibitors, such as bisphosphonates, are potentially useful in treatments aimed at increasing bone mass. Among bisphosphonates, tiludronate has proven efficacious in preventing bone loss in postmenopausal women. However, it is not clearly established whether bisphosphonates are more potent when given intermittently or continuously. We investigated the effects of tiludronate on (1) retinoid-stimulated bone resorption in thyroparathyroidectomized rats, (2) calcium balance in intact rats, and (3) bone mineral density (BMD) as measured by dual-energy x-ray absorptiometry at the levels of the lumbar spine, tail, and tibia in 6-month-old rats made osteoporotic by ovariectomy (OVX), in which an intermittent cyclic schedule of treatment was compared to continuous administration. Tiludronate induced a dose-dependent decrease in retinoid-stimulated bone resorption. It increased the intestinal absorption and body retention of calcium. In OVX rats it caused a time- and dose-dependent increase in BMD at the level of the three investigated sites, the effects being maintained for at least 8 weeks after the end of therapy. Continuous and intermittent cyclic regimens appeared to induce similar increases in BMD. These results indicate that tiludronate is efficacious in decreasing bone resorption and increasing calcium balance and bone mineral density in rats.

Animals↗
PubMed1993

Strong immunogenicity of a multicomponent peptide vaccine developed with the branched lysine oligopeptide method for human immunodeficiency virus infection.

We synthesized one V3 peptide each from HTLV-IIIB, Thai A and Thai B, conjugating them to the T cell epitope of the env region, and we also synthesized a p17 protein peptide of the gag region (HGP-30). These peptides were then coupled to 8-lysine copolymers using N-succinimidyl maleimido carboxylate (M(r) = ca 60,000). We designated this the branched lysine oligopeptide method. The large peptide complexes constructed from these four macromolecular peptides were used with aluminium hydroxide or complete Freund's adjuvant to immunize mice and rabbits four times. ELISA assay showed high titres of anti-peptide antibodies to each V3 loop peptide and the HGP-30 peptide. Strong inhibition of CD4+ dependent cell fusion was obtained with these antisera when IIIB, Thai A and Thai B strains of the human immunodeficiency virus (HIV) were used. Strong anti-fusion inhibition was also observed with two other HIV strains. In addition, an increase of the anti-HIV effect was observed when we used sera obtained by multicomponent vaccine immunization. The same kind of inhibition was also observed in p24 assay systems using these immunized antisera. Activation of IL-2 production in lymphocytes was observed in mice immunized with this vaccine. These results suggest that immunization with macromolecular peptide complexes can result in strong immunogenicity towards HIV-1.

AIDS Vaccines↗