Biomedical subjects

T Uchida

Publications and source records attributed to T Uchida.

At least 379 records · Page 21Linked to original sources

PubMed1996

Diagnosis of borderline adenomas of the stomach by endoscopic mucosal resection.

BACKGROUND AND STUDY AIMS: The correct histological diagnosis of gastric borderline adenomas is often difficult, especially in excluding malignancy, since the usual diagnostic methods, such as radiography and histological examination of forceps biopsy specimens, are of limited accuracy. The aim of this study was to retrospectively analyze the value of endoscopic mucosal resection in establishing the correct diagnosis of borderline adenomas. RESULTS: Fourteen borderline adenomas were finally diagnosed as containing early gastric cancer type IIa (well-differentiated tubular adenocarcinoma) after endoscopic mucosal resection, of the remaining 36 tubular adenomas, six represented mild dysplasia, 24 moderate dysplasia, and six severe dysplasia. Most parts of the 14 adenomas containing early gastric cancers had regions of structural atypia, and cellular atypia was moderate in all. Seven of 14 cancers were completely resected, all patients being tumor-free after a follow-up of 33-61 months. CONCLUSIONS: These results suggest that diagnosing borderline adenoma on the basis of radiographic and endoscopic-bioptic findings is generally unreliable, because biopsy specimens may not be representative of the entire lesion. Borderline adenomas of the stomach should be completely resected by endoscopic mucosal resection to obtain a final diagnosis and - depending on the size and type of the lesion - possibly also definitive treatment.

Adenoma↗

PubMed1996

Significance of preoperative parameters for predicting tumor volume in nonpalpable prostate cancer.

Preoperative parameters were assessed for their usefulness in predicting tumor volume in 26 cases of nonpalpable prostate cancer. The number of positive biopsy cores was found to be the parameter which predicted most accurately tumor volume in surgical specimens. All 14 patients with multiple positive cores had an index tumor of 0.5 cm3 or more in radical prostatectomy specimens. Only six tumors with a single positive core were substantial. Three of the patients showed a serum level of prostate specific antigen (PSA) of 4.0 ng/ml or more. The pathological stage and prostatectomy Gleason sum could not be predicted accurately by this variable (P>0.05). To predict index tumor volumes of 1.0 cm3 or greater, stepwise logistic regression analysis was conducted, and on the basis of the results it was possible to single out multiple positive biopsies as the only significant variable. The number of positive biopsies appeared reliable for predicting tumor volume of surgical specimens in cases of nonpalpable disease. The presence of significant tumors despite "normal" levels of PSA warrants further investigation of variables that can predict such prostate cancers. An adequate model for predicting significant tumors in oriental male populations should be established using samples of larger size.

Biopsy, Needle↗

PubMed1996

Preoperative serum prostate-specific antigen, clinical stage and Gleason sum as basis for predicting final pathological stage in Japanese patients with prostate cancer.

By logistic regression analysis and log-likelihood ratio chi-square test, the usefulness of preoperative variables (prostate specific antigen [PSA], clinical stage and biopsy Gleason sum) for predicting the final pathological stage was assessed in 77 patients with clinically resectable prostate cancers. Pathologically, 32 (41.6%) had organ-confined disease. Extracapsular extension was found in 41 (53.2%), seminal vesicle involvement in 30 (39.0%), positive pelvic lymph nodes in 10 (13.0%) and a positive surgical margin in 27 (35.1%). Each preoperative variable was found to be significantly associated with the final pathological stage. Any combination of these variables was more predictive for extraprostatic disease, compared with each individual variable. Extraprostatic spread was found more frequently in patients with lower serum PSA in this Japanese elderly male population compared with North American males. These preoperative variables considered in combination may provide valuable information for management decisions related to prostate cancer. Serum PSA alone cannot reliably predict pathological stage on an individual basis except in patients with a PSA level of 20 ng/ml or greater. The high incidence of extraprostatic spread at intermediate PSA underscores the importance of selecting an ideal cutoff value for PSA-based screening in a Japanese male population.

Aged↗

PubMed1996

Validation in volunteers of a near-infrared spectroscope for monitoring brain oxygenation in vivo.

Cerebral oximeters based on near-infrared spectroscopy may provide a continuous, noninvasive assessment of cerebral oxygenation. We evaluated a prototype cerebral oximeter (Invos 3100; Somanetics, Troy, MI) in 22 conscious, healthy volunteers breathing hypoxic gas mixtures. Using the first 12 subjects (training group), we developed an algorithm based on the mathematic relationship that converts detected light from the field surveyed by the probe to cerebral hemoglobin oxygen saturation (CSfO2). To develop the algorithm, we correlated the oximeter result with the estimated combined brain hemoglobin oxygen saturation (CScombO2, where CScombO2 = SaO2 x 0.25 + SjO2 x 0.75 and SjO2 = jugular venous saturation). We then validated the algorithm in the remaining 10 volunteers (validation group). A close association (r2 = 0.798-0.987 for individuals in the training group and r2 = 0.794-0.992 for individuals in the validation group) existed between CSfO2 and CScombO2. We conclude that continuous monitoring with cerebral oximetry may accurately recognize decreasing cerebral hemoglobin oxygen saturation produced by systemic hypoxemia.

Adult↗

PubMed1996

The influence of carbon dioxide and body position on near-infrared spectroscopic assessment of cerebral hemoglobin oxygen saturation.

Near-infrared spectroscopy may allow continuous and noninvasive monitoring of regional brain hemoglobin oxygen saturation by measuring the differential absorption of infrared light by oxyhemoglobin and deoxyhemoglobin. We have previously examined the correlation between the spectroscopic signal generated by a prototype cerebral oximeter (Invos 3100; Somanetics, Troy, MI), and global brain hemoglobin oxygen saturation calculated from arterial and jugular venous bulb oxygen saturations. Because the technology does not distinguish between arterial and venous hemoglobin saturation, changes in the proportion of cerebral arterial and venous blood volume, which may result from changes in blood flow or venous distending pressure, may confound measurements. In eight conscious volunteers breathing hypoxic oxygen mixtures, we examined the influence of supine, 20 degrees Trendelenburg, and 20 degrees reverse Trendelenburg positions on the correlation of the spectroscopic measurement of cerebral oxygen saturation in the field assessed by the probe (CSfO2) and the calculated brain hemoglobin oxygen saturation (CScombO2), estimated as 0.25 x arterial saturation plus 0.75 x jugular venous bulb oxygen saturation. We found that changes in position did not influence the association between CSfO2 and CScombO2 (r2 = 0.69-0.885) during hypoxic challenge. In a second set of eight volunteers, we studied the influence of hypercapnia and hypocapnia and body position on the association between CSfO2 and CScombO2, and found that they were less well correlated (r2 = 0.366-0.976) in individual patients. Because changes in body position and Paco2 confound the relationship between CSfO2 and CScombO2, changes in CSfO2 can best be assessed if position and Paco2 are constant.

Adult↗

PubMed1996

Antithrombin III prevents renal dysfunction and hypertension induced by enhanced intravascular coagulation in pregnant rats: pharmacological confirmation of the benefits of treatment with antithrombin III in preeclampsia.

We tested the hypothesis that enhanced intravascular coagulation in pregnancy could produce clinical symptoms similar to those of preeclampsia, such as hypertension, proteinuria, and edema. Having confirmed this, we then examined whether the pathological changes caused by intravascular coagulation could be suppressed by administration of antithrombin III (AT III), an endogenous inhibitor active to thrombin and factor X a. Intravascular coagulation was induced in Wistar rats on day 16-20 of pregnancy by 1-h arterial infusion of tissue thromboplastin (TP) through the left ventricle of the heart. One hour after the end of the infusion period, organ blood flows were measured by the radioactive ((57)Co-labeled) microsphere method, and fibrin deposition in organs was measured by radiolabeling with [(125)I] fibrinogen injected before TP infusion. Infusion of TP produced fibrin deposition in the kidney, lung, and liver, but not in the myometrium and placenta, as well as an 80% decrease in renal blood flow (RBF), with oliguria and proteinuria. TP also caused an increase in blood pressure (BP) accompanied by an increase in plasma renin activity (PRA), both of which were suppressed by bilateral nephrectomy before TP infusion. The prophylactic administration of AT III concentrates (60 or 300 U/kg intravenously (i.v.), followed by infusion of 30 or 150 U/kg/2 h, respectively) prevented all pathological changes in a dose-dependent manner. AT III increased placental blood flow regardless of the state of coagulation. These findings suggest that intravascular coagulation plays a significant part in the pathophysiology of preeclampsia and that AT III concentrates may have therapeutic potential in the treatment of this condition.

Animals↗

PubMed1996

Demonstration of a heat-stable 120-kilodalton protein of Rickettsia japonica as a spotted fever group-common antigen.

Genomic libraries of Rickettsia japonica were cloned into an expression vector lambda gt11. A clone expressing a protein reactive with antiserum against 120-kilodalton (kDa) proteins, a mixture of heat-modifiable and heat-stable polypeptides, was selected and designated as lambda Rj120-1. The expressed protein has a molecular mass of 180 kDa. Western immunoblotting demonstrated that the expressed protein was a fusion protein with beta-galactosidase. The antiserum against 120-kDa proteins was absorbed by the induced lysogen, resulting in the removal of reactivity to the heat-stable 120-kDa polypeptide. The antiserum against the expressed protein reacted with heat-stable 120- to 130-kDa polypeptides of spotted fever group (SFG) rickettsiae in addition to R. japonica. The findings indicated that the protein expressed from the cloned gene of R. japonica possessed the antigenicity group-common to SFG rickettsiae. Primers designed from the gene coding for R. conorii heat-stable 120-kDa protein (Schuenke, K.W., and Walker, D.H., Infect. Immun. 62: 904-909, 1994) and lambda gt11 lacZ gene amplified the lambda Rj120-1 DNA by the polymerase chain reaction (PCR). Analysis of restriction fragment length polymorphism (RFLP) of the PCR-amplified products revealed that the cloned DNA corresponds to a portion of the gene coding for the heat-stable 120-kDa protein of R. conorii with 2,519 nucleotides beginning at nucleotide 190 of the open reading frame. RFLP demonstrated that the cloned gene was highly homologous to the corresponding gene of R. conorii.

Animals↗

PubMed1996

Treatment of gastric fundal varices by balloon-occluded retrograde transvenous obliteration.

Although less common than oesophageal varices in portal hypertension, gastric fundal varices carry a higher mortality rate when they rupture. They are less amenable to sclerotherapy. We have developed a minimally invasive balloon-occluded retrograde transverse obliteration (B-RTO) procedure to treat gastric fundal varices. B-RTO involves inserting a balloon catheter into an outflow shunt (gastric-renal or gastric-vena caval inferior) via the femoral or internal jugular vein. Blood flow is then blocked by inflating the balloon, and 5% ethanolamine oleate iopamidol is injected in a retrograde manner. The embolized gastric varix subsequently disappears. B-RTO was performed in 32 patients with gastric varices. Follow-up endoscopies were performed at intervals of 2-4 months for an average observation period of 14 months. Eradication of the varices has been confirmed in 31 of 32 patients. No recurrence occurred in any patients in the follow-up period. There were no significant changes in liver function after the procedure. We conclude that B-RTO is a safe and effective procedure for the treatment of gastric fundal varices.

Adult↗

PubMed1996

Endemicity and clinical picture of liver disease due to obstruction of the hepatic portion of the inferior vena cava in Nepal.

Obstructive lesion of the hepatic portion of the inferior vena cava is common in Nepal. The clinical data on 150 patients who were seen at the Liver Unit, Bir Hospital, Kathmandu, in three years from 1990 to 1992 were analysed. Although the majority of patients were over 20 years of age, 25 patients were below 10 years of age; there were more males than females in this study. This disease accounted for 17% of 866 patients with chronic liver disease and for nearly one quarter of 267 biopsies performed on this patient group during the same period. Obstructive lesions of the inferior vena cava seem to be more common among poor people with malnutrition. Clinically, our patient group could be divided into acute (n = 27), subacute (n = 43) and chronic (n = 80) cases. The important clinical features are hepatomegaly and/or ascites and, in chronic cases, prominent dilated superficial veins over the body trunk with cephalad flow. Ultrasound is the most helpful diagnostic procedure, especially in subacute and chronic cases, as it frequently demonstrates caval obstruction, thrombosis, dilated hepatic veins and intrahepatic collaterals. Diagnosis is confirmed by cavography, which shows a caval obstruction of varying lengths at the cavo-atrial junction or a marked narrowing of the hepatic portion of the vena cava. In subacute and chronic cases cavography also demonstrates collateral veins, such as the ascending lumbar, hemiazygos and azygos that drain into the superior vena cava. Chronic cases had periods of exacerbation often associated with bacterial infection. The aetiology of inferior vena cava obstruction at its hepatic portion is not known, but there seems to be a frequent association of bacterial infection with the disease.

Acute Disease↗

PubMed1996

Transient elevation of nerve growth factor content in the rat hippocampus and frontal cortex by chronic ethanol treatment.

The nerve growth factor (NGF) content in the hippocampus and frontal cortex of chronic ethanol-treated rats was measured and compared with that of control rats, using a two-site enzyme immunoassay (EIA) system. The different time periods of chronic ethanol treatment caused transient elevation of the NGF content in both the hippocampus and frontal cortex. The NGF content in the hippocampus was significantly elevated in rats undergoing ethanol treatment of 2 weeks and 1 month. Nerve growth factor content of the 1 month treatment was higher than that of the 2 week treatment. However, a 3 month administration of ethanol reduced the NGF content to the control level. The NGF content in the frontal cortex increased significantly in the 2 week administration, but decreased to the control level in the 1 month administration. The increase of NGF may be caused by the proliferation of glial cells or the enhancement of neuronal production of NGF.

Animals↗

PubMed1996

A non-randomized comparative study of visual laser ablation and transurethral resection of the prostate in benign prostatic hyperplasia.

BACKGROUND: Transurethral resection of the prostate (TURP) has been the preferred surgical treatment for benign prostatic hyperplasia (BPH) for the past 50 years. Alternative methods for treating BPH such as visual laser ablation (VLAP) have been established during the past decade. In order to assess the safety and efficacy of VLAP, this alternative method was performed using a Urolase fiber and neodymium: yttrium-aluminum-garnet laser, and compared to results obtained in patients treated with TURP for BPH. METHODS: In this non-randomized comparative study, 100 BPH patients were equally split between treatment with VLAP or TURP, and their cases compared. The efficacy was assessed using an International Prostate Symptom Score, urinary flow rates, post-void residual urinary volume and an estimated prostate volume. RESULTS: There was a clinically significant improvement in all parameters in both groups. In the VLAP and TURP groups, 92.0% and 81.6%, 90.2% and 86.2 and 93.1% and 100.0% were categorized as effectively-treated cases at 3, 6 and 12 months post-operatively, respectively. No severe side effect was seen in VLAP group. The total and post-operative lengths of hospitalization in the VLAP group were shorter, but the duration of post-operative bladder irrigation was longer in these patients. CONCLUSIONS: Although TURP remains the standard surgical treatment for BPH, VLAP is associated with less morbidity and the clinical outcome is similar compared to patients treated with TURP. VLAP in conjunction with TURP may result in less risk of postoperative urinary retention and vesical irritability.

Aged↗

PubMed1996

Giant retroperitoneal cyst in an adult male.

This paper presents a case of a symptomatic giant retroperitoneal cyst in an adult male. The unilocular cyst was excised successfully with resolution of the attendant symptoms. Histological findings of the cyst wall suggested a lymphangiomatous etiology. Any good risk patient found to harbor such a cyst should undergo complete excision in view of the potential for the development of symptoms and complications.

Cysts↗

PubMed1996

In-vitro metabolism of YM17E, an inhibitor of acyl coenzyme A:cholesterol acyltransferase, by liver microsomes in man.

Because YM17E (1,3-bis[[1-cycloheptyl-3-(p-dimethylaminophenyl) ureido]methyl]benzene dihydrochloride) inhibits acyl coenzyme A:cholesterol acyltransferase (ACAT) it has potential application in the treatment of hypercholesterolaemia. In man and animals YM17E is extensively metabolized, via N-demethylation, to five active metabolites (M1, M2-a, M2-b, M3 and M4). The main objectives of this study were to examine inhibition of YM17E metabolism by the products and identify the cytochrome P450 isoforms in liver microsomes which catalyse in-vitro YM17E metabolism in man. In microsomes in man N-demethylation of YM17E to M1 occurred enzymatically; for up to 45 s the rate was linearly proportional to the microsomal protein concentration. This reaction was inhibited by metabolites M2-a, M2-b, M3 and M4. Further, N-demethylation of [14C]-YM17E was also inhibited by its product, M1. These results showed that primary metabolism of YM17E was inhibited by its products, and supported the finding that the non-linear increase in plasma concentration of the parent drug and metabolites observed in an in-vivo study was due to inhibition by these products. Metabolic activity in microsomes from ten individual human livers demonstrated that YM17E N-demethylase activity correlated closely with testosterone 6 beta-hydroxylase activity. When cytochrome P450 isozyme-specific substrates and chemical inhibitors were used to inhibit YM17E N-demethylase activity, CYP3A-specific substrate and inhibitors such as nifedipine, ketoconazole and triacetyloleandomycin strongly inhibited this activity, whereas CYP1A-specific substrate or inhibitor, ethoxyresorufin and alpha-naphthoflavone, inhibited weakly. Other CYP inhibitors, in contrast, had few or no effects. An inhibition study using anti-rat CYP1A1, CYP2B1, CYP2C11, CYP2E1 and CYP3A2 antibodies demonstrated that only anti-rat CYP3A2 antibody inhibited YM17E metabolism, to 40% of control level, with no other antibodies showing an inhibitory effect. Of seven cDNA-expressed P450 isoforms in man (CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2D6, CYP2E1 and CYP3A4), CYP3A4, CYP2D6 and CYP1A2 isozyme exhibited substantial catalytic activity of N-demethylation of YM17E. These results indicate the predominant role of CYP3A4 in liver metabolism of YM17E in man.

Chromatography, High Pressure Liquid↗

PubMed1996

Urinary excretion profile of torasemide and its diuretic action in dogs.

The plasma concentration profile, urinary excretion rate and diuretic response were studied in anaesthetized dogs after an intravenous administration of torasemide or furosemide. The urinary excretion rate of furosemide decreased rapidly after administration. The plasma concentration, which is related to the urinary excretion profile, also decreased rapidly. The diuretic response, which reflected the excretion rate, occurred rapidly after administration but lasted for a short time. The urinary excretion rate of torasemide was much lower than that of furosemide and decreased slowly after administration. The plasma concentration also decreased slowly. The diuretic response to torasemide occurred more slowly but lasted longer than the response to furosemide. These results suggest that the diuretic response profile of either diuretic depends on their urinary excretion rate, and that the difference in the diuretic response between torasemide and furosemide may be explained by the different transfer rate of the drugs from the plasma to the nephron.

Animals↗

PubMed1996

Fluid compartments in hemorrhaged rats after hyperosmotic crystalloid and hyperoncotic colloid resuscitation.

Postresuscitation organ failure may be associated with detrimental changes in body fluid compartments. We measured how shock and resuscitation acutely alters the interstitial, cellular, and plasma compartments in different organs. Nephrectomized, anesthetized rats were bled to 50 mmHg mean arterial pressure for 1 h, followed by 60 min of resuscitation to restore blood pressure using 0.9% normal saline (NS,n = 10), 7.5% hypertonic saline (HS,n = 8), 10% hyperoncotic albumin (HA, n = 8), or 7.5% hypertonic saline and 10% hyperoncotic albumin (HSA, n = 7). A 2-h 51Cr-EDTA distribution space estimated extracellular fluid volume (ECFV), and a 5-min 125I-labeled albumin distribution space measured plasma volume (PV). Total tissue water (TW) was measured from wet and dry weights; interstitial fluid volume (ISFV) and cell water were calculated. NS resuscitation required 7 times more fluid (50.9 +/- 7.7 vs. 8.6 +/- 0.7 for HA, 5.9 +/- 0.4 for HS, and 3.9 +/- 0.5 ml/kg for HSA), but there were no differences between solutions in whole animal PV, ECFV, or ISFV. Fluid shifts within tissues depended on resuscitation solution and type of tissue. TW was significantly reduced by hypertonic saline groups in heart, muscle, and liver (P < 0.05). ISFV was significantly reduced by HA groups in the skin. In all tissues, mean cell water in groups receiving HS was smaller; this was significant for heart, lung, muscle, and skin. In conclusion, 1) HS solutions mobilize fluid from cells while expanding both PV and ISFV, and 2) TW and cellular water increase with both isotonic crystalloids and hyperoncotic colloids in many tissues.

Albumins↗

PubMed1996

Ovalbumin-liposome conjugate induces IgG but not IgE antibody production.

Antibody response after immunization with surface-coupled ovalbumin (OVA) of liposomes was investigated in mice. OVA was coupled to the surface of liposome via amino groups using glutaraldehyde. OVA-liposome conjugate induced a significant anti-OVA IgG antibody production in mice. However, no IgE antibody production specific for OVA was observed. Immunization with OVA-liposome induced IgE-specific unresponsiveness even after the subsequent challenge with OVA adsorbed with with aluminium hydroxide (OVA-alum), which induces a high level of IgE antibody production. Furthermore, following the primary immunization with OVA-alum, a secondary challenge with OVA-liposome boosted anti-OVA IgG but not anti-OVA IgE antibody production. These results show the potential of the antigen-liposome conjugate for the development of a vaccine with the least allergic reaction and also for the application of immunotherapy.

Aluminum Hydroxide↗

PubMed1996

Common carotid artery wall properties in Takayasu's arteritis.

The vessel wall properties of the common carotid artery have been noninvasively and quantitatively assessed with an ultrasonic instrument. Stiffness parameter beta, which represents the mechanical properties of the vessel, was calculated from the relationship between blood pressure and the diameter of the artery. There are no reports that quantitatively assess wall properties in Takayasu's arteritis. The authors compared, in vivo, the vessel wall properties of the common carotid artery in 14 patients with Takayasu's arteritis versus those in 60 normal subjects (controls). They measured changes in the inner diameter of the artery between systole and diastole with an ultrasonic, phase-locked, echo-tracking system. Beta was significantly higher in Takayasu's arteritis than in normal subjects (better than a 99% confidence interval). The findings for each decade were as follows: 3rd decade (20s): 35.7 +/- 28.9 vs 5.01-6.46, P=0.0001; 4th decade (30s): 19.5 +/- 9.71 vs 6.09-7.80, P=0.02; 5th decade (40s): 26.2 +/- 11.3 vs 7.26-9.28, P = 0.0001; 6th decade (50s): 19.1 +/- 4.27 vs 8.66-11.25, P = 0.0001. Takayasu's arteritis significantly impaired the mechanical performance of the common carotid artery. Thus, beta shows promise as a useful diagnostic indicator of Takayasu's arteritis.

Adult↗

PubMed1996

Role of leukotriene B4 and interleukin-8 in acute bacterial and viral otitis media.

In order to evaluate the role of polymorphonuclear leukocytes (PMNs) in acute otitis media (AOM), levels of leukotriene B4 (LTB4), a potent inflammatory product of PMNs, and interleukin-8 (IL-8), a PMN chemotactic cytokine, were measured in 271 middle ear fluid (MEF) samples from 106 children with AOM. Forty-two percent of the patients had evidence of respiratory viral infection. At the time of diagnosis, levels of both LTB4 and IL-8 were higher in the MEFs from patients with AOM associated with bacterial or bacterial and viral infection than those MEFs containing no pathogen (p < .05). Antibiotic treatment was not associated with a significant change in levels of LTB4 or IL-8 in the MEFs obtained 2 to 5 days into treatment, compared to those obtained at diagnosis. Bacteriologic failure after 2 to 5 days of treatment was associated with high LTB4 levels in the initial MEFs (p = .05). Recurrence of AOM within 1 month was associated with high IL-8 levels in the initial MEF (p = .04). Our findings suggest that LTB4 and IL-8 are produced during acute infection of the middle ear, and these PMN-related inflammatory substances may play an important role in delaying recovery or in recurrence of AOM. Effective treatment of AOM may require eradication of bacteria by antibiotics, as well as pharmacologic agents that modulate PMN functions.

Bacterial Infections↗