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Biomedical subjects

H Maeda

Publications and source records attributed to H Maeda.

At least 1,549 records · Page 86Linked to original sources

Immunogenetics of uveitis in leprosy.

PURPOSE: To identify any possible determinants in the development of uveitis in leprosy patients. METHODS: Human leukocyte antigen (HLA) class I and II antigen, and HLA class II genotypings were analyzed among Japanese leprosy patients. Ninety-three unrelated Japanese leprosy patients (46 patients with a history of uveitis and 47 patients without uveitis) and 114 healthy control subjects were investigated. RESULTS: The occurrence of HLA-DR2 was significantly higher in patients with uveitis (78.3%) than in those without uveitis (57.4%; odds ratio = 2.7, P<.05) and in the controls (33.3%; odds ratio = 7.2, P<.0000005, Pc<.00005). The occurrence of HLA-DR4 was significantly lower in patients with uveitis (15.2%) than in those without it (38.3%; odds ratio = 0.29, P<.05) and in the controls (46.5%; odds ratio = 0.21, P<.0005, Pc<.05). Furthermore, the frequencies of DR2-positive and DR4-negative genotypes were significantly higher in patients with uveitis (69.6%) than in those without it (38.3%; odds ratio = 3.7, P<.005) and in the controls (21.9%; odds ratio = 8.1, P<.00000005). At the genomic level, the occurrence of HLA-DQB1*0302 was significantly lower in the patients with uveitis (8.7%) than in those without it (25.5%; odds ratio = 0.28, P<.05). The distribution of HLA-DRB1 and DQA1 alleles was not significantly different between the patients with and those without uveitis. However, the frequencies of DRB1*1501-positive, as well as DRB1*0405- and DQB1*0302-negative genotypes were significantly higher in the patients with uveitis (47.8%) than in those without it (25.5%; odds ratio = 2.7, P<.05) and in the controls (8.8%; odds ratio = 9.5, P<.00000005). CONCLUSIONS: Our results suggest that HLA Class II genes confer susceptibility to or protection from leprous uveitis.

Adolescent↗

Morphometric features of laminar pores in lamina cribrosa observed by scanning laser ophthalmoscopy.

PURPOSE: To describe a method for making morphometric analysis of the pores in the lamina cribrosa with a confocal scanning laser ophthalmoscope (SLO). METHODS: Sixteen consecutive images were acquired with an SLO from the retinal surface to the bottom of the optic disc in +0.25-diopter increments. An He-Ne laser (633 nm) with a 20 degrees field of view was used. The images from each section were processed and combined with the aid of Macintosh software. RESULTS: Eyes with physiological cupping showed uniformly round or nearly round pores, whereas eyes with primary open-angle glaucoma frequently had compressed pores. CONCLUSIONS: In vivo morphometry of the surface of the internal lamina cribrosa can be performed by this technique, which should be useful for evaluating the progression of glaucomatous changes of the optic nerve head.

Glaucoma, Open-Angle↗

Video viewing as an alternative to sedation for young subjects who have cardiac ultrasound examinations.

Sedation is often required for extended or quantitative echocardiographic examination of young patients. To test the hypothesis that patient viewing of entertaining videotapes during echocardiographic examinations would reduce the need for sedation and that Doppler pressure gradients so obtained would correspond satisfactorily with subsequent catheterization pressure gradients, 38 patients (age, 5 to 64 months; mean age, 18.6 months) with a variety of cardiac defects were studied. Because of excessive activity, resistance, fear, or crying, all of these patients would have normally been sedated. Instead, an age-appropriate videotape was used for patient viewing. In 35 of 38 patients, complete examinations were obtained with video viewing with no sedation. Twelve study patients later underwent catheterization while receiving sedation. The Doppler pressure gradients obtained while patients were viewing videotapes corresponded well with catheterization (r = 0.94). However, those pressure gradients were higher than those obtained with catheterization (mean, 8.3 mm Hg), but there was only one significant discrepancy of 22 mm Hg. In this series, complete examinations were obtained without sedation in 92% of subjects who would have normally required sedation (p less than 0.001), with minimal reduction in the accuracy of prediction of subsequent sedated catheterization pressure gradients. This suggests that near baseline conditions existed while patients were viewing television. Video viewing during echocardiographic examinations appears to be advantageous.

Cardiac Catheterization↗

Effects of dietary arginine supplementation on protein turnover and tissue protein synthesis in scald-burn rats.

We assessed the effects of dietary arginine supplementation on protein turnover and organ protein synthesis in burned rats. Male Wistar rats weighing about 200 g underwent catheter jejunostomy and received scald burns covering 30% of the whole-body surface area. Animals were divided into a control group (n = 9) and an arginine group (n = 9) and continuously received total enteral nutrition for 7 d (250 kcal.kg-1.d-1, 1.72 gN.kg-1.d-1). Changes in body weight, plasma total protein, plasma albumin, urinary excretion of polyamines, nitrogen balance, whole-body protein kinetics, and tissue protein synthesis rates were determined. Whole-body protein kinetics and tissue fractional protein synthetic rates (Ks, percent/d) were estimated using a 24-h constant enteral infusion of 15N glycine on the last day. The changes in body weight were not different between the control and arginine groups. The urinary excretion of polyamines was higher in the arginine group than in the control group (P < 0.01). Burned rats enterally fed arginine-supplemented diet yielded significantly greater cumulative and daily nitrogen balance on days 3 and 5 than those fed a control diet (cumulative, P < 0.05; day 3, P < 0.01; day 5, P < 0.01). Whole-body protein turnover rate was significantly elevated in the arginine group as compared to that in the control group (P < 0.05). The Ks of rectus abdominis muscles were significantly increased in the arginine group in comparison to the control group (P < 0.01). We have shown that dietary arginine supplementation improved protein anabolism and attenuated muscle protein catabolism after thermal injury.

Animals↗

A survey of autologous blood collection and transfusion in Japan in 1997.

BACKGROUND: In spite of the fact that autologous blood is safest for a patient to receive, it is not generally appreciated that adverse reactions during donation and transfusion may occur. This study was conducted to assess the state and the risk of autologous blood transfusion in Japan in 1997. STUDY DESIGN AND METHODS: Results of a nation-wide questionnaire-based survey are presented. The questionnaire assessed the number of autologous blood donations, donation procedures, and the adverse reactions associated with donation, preservation, recombination erythropoietin administration and transfusion. RESULTS: Between November 1996 and October 1997, 10,697,000 ml (or 53,485 units, 200 ml = 1 unit) prestorage blood donation were made by 14,200 patients (averages; 1.9 donations/patient, 753 ml/patient, 398 ml/donation). Of these, 87% were transfused to the patients and the remainder were discarded. Using hemodilution and blood salvage intra- or postoperatively some 2,540,000 ml of blood was collected and > 70% of patient-donors received such blood. Adverse reactions were observed with 1.6% (428/26,905) of donations including 6 angina and 2 asthma attacks. There were 63 (0.2%) problems with 28,705 donations and 117 (0.5%) errors/problems reported for 24,929 units transfused; the most frequent problems were clotting on the units and breakage of the bags during storage. Hypotension using hemodilution (3.7%), coagulation (0.9%) or bacterial contamination (0.4%) using salvage were often observed. A 10-20 ml volume of autologous fresh-frozen plasma was transfused to the wrong recipient. CONCLUSION: Autologous blood transfusion accounts for at least 1.1% (2.8% estimated) of the red cell supply in Japan. Errors and adverse reactions are not infrequent in autologous blood programmes. By introducing systematic safety policies, we will be able to make autologous blood transfusion safer.

Adolescent↗

Dose-dependency of hepatocellular necrosis in a canine model of chemoembolization.

PURPOSE: The degree of local tissue toxicity from hepatic arterial chemoembolization relative to the dose of anticancer drugs was evaluated in 13 dogs. MATERIALS AND METHODS: Animals were divided into four groups. Group 1 was the control group in which embolization was performed with gelatin sponge particles only (n = 4); group 2 animals underwent embolization with 0.4 mg/kg of Adriamycin (ADR) and 0.2 mg/kg of mitomycin C (MMC) (n = 4); group 3, with 0.8 mg/kg of ADR and 0.4 mg/kg of MMC (n = 2); and group 4, with 1.6 mg/kg of ADR and 0.8 mg/kg of MMC (n = 3). RESULTS: Animals were killed 1 week after embolization, and histopathologic evaluation was performed. The average percentage liver necrosis in the embolized lobe was 0% in group 1, 1% in group 2, 85% in group 3, and 92% in group 4. CONCLUSION: Hepatic arterial chemoembolization with high doses of anticancer drugs causes severe liver damage, but 0.4 mg/kg of ADR and 0.2 mg/kg of MMC is relatively safe, causing only minimal changes in this canine model.

Animals↗

Conjugation of Cu,Zn-superoxide dismutase with succinylated gelatin: pharmacological activity and cell-lubricating function.

Superoxide dismutase (SOD) and succinylated gelatin (succinyl gelatin) were conjugated to improve in vivo pharmacological activity of SOD. Lysyl residues of human recombinant Cu,Zn-SOD were cross-linked with carboxyl residues of succinyl gelatin using 1-ethyl-3-[3- (dimethylamino)propyl]carbodiimide. Various chemical and pharmacokinetic parameters of the conjugate were determined. Analysis by atomic absorption spectrometry and amino acid composition revealed that the conjugate was composed of about 2.9 mol of succinyl gelatin (with a mean molecular weight of 23,000) to 1 mol of SOD and exhibited an apparent mean molecular weight of 98,000. The conjugate retained almost 100% of its original activity on a molar basis. When the succinyl gelatin-conjugated Cu,Zn-SOD (Suc-gel-SOD) was administered intravenously to mice, its plasma half-life was prolonged to 29.7 min compared with 4.5 min for native SOD. Tissue distribution analysis revealed that intravenously administered Suc-gel-SOD showed a much greater accumulation than native SOD in the liver followed by in decreasing order the kidney, the lung, and the spleen; native SOD was excreted more rapidly into urine before it accumulated in tissues. Furthermore, Suc-gel-SOD exhibited lower antigenicity and immunogenicity than native SOD, and it had a better therapeutic effect against ischemic edema of the foot pad in mice. The conjugate was found to accumulate more than native SOD in the ischemic foot pad. A newly added property of the conjugate is cell-lubricating activity, which facilitated cell passage through micropores and reduced hemolysis during cell passage in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Pegylated zinc protoporphyrin: a water-soluble heme oxygenase inhibitor with tumor-targeting capacity.

Heme oxygenase (HO) is a key enzyme in heme metabolism; it oxidatively degrades heme to biliverdin, accompanied by formation of free iron and carbon monoxide. Biliverdin is subsequently reduced by cytosolic biliverdin reductase to form bilirubin, a potent antioxidant. We recently found that tumor cells utilize HO to protect themselves from oxidative stress by producing the antioxidant bilirubin. This result suggested an important potential therapeutic strategy: suppression of bilirubin production with the use of HO inhibitors; hence, cancer cells become vulnerable to oxidative stress induced by anticancer drugs or leukocytes of the host. This concept was validated by using the intraarterial administration of an HO inhibitor, zinc protoporphyrin, in nonphysiological solution. In the present study, zinc protoporphyrin (ZnPP) was conjugated with poly(ethylene glycol) (PEG) with molecular weight of 5000, to make ZnPP, a water-soluble compound (PEG-ZnPP), and to improve its tumor-targeting efficiency. PEG was conjugated to ZnPP through newly introduced amino groups, where ethylenediamine residues were added at C6 and C7 of protoporphyrin. The divalent zinc cation was chelated into the protoporphyrin ring to obtain PEG-ZnPP. PEG-ZnPP did become highly water-soluble, and it formed multimolecular associations with molecules larger than 70 kDa in aqueous media. PEG-ZnPP inhibited splenic microsomal HO activity in vitro in a competitive manner in the presence of hemin, with an apparent inhibitory constant of 0.12 microM. Most important, PEG-ZnPP injected intravenously significantly suppressed intratumor HO activity in a murine solid tumor model, which suggests that tumor-targeted inhibition of HO is possible with the use of PEG-ZnPP.

Animals↗

Detection of doxorubicin cardiotoxicity by using iodine-123 BMIPP early dynamic SPECT: quantitative evaluation of early abnormality of fatty acid metabolism with the Rutland method.

BACKGROUND: To evaluate the possibility of predicting the development of doxorubicin-induced cardiomyopathy, we performed quantitative assessment of the early kinetics of iodine-123 beta-methyl-iodophenyl-pentadecanoic acid (I-123 BMIPP) by means of dynamic myocardial SPECT. METHODS: Thirty-six patients with various malignancies were examined. I-123 BMIPP dynamic myocardial SPECT was performed before chemotherapy, after chemotherapy, or both. Immediately after the injection of I-123 BMIPP (111 MBq), 30-second dynamic SPECT data were acquired successively for 15 minutes. The left ventricular (LV) myocardium was divided into 8 segments in short-axial and vertical slices. By using the time-activity curve (TAC) of each myocardial segment [Mo(t)] as an output function and the TAC of the LV cavity [B(t)] as an input function, the Rutland equation, Mo(t)/B(t)= F + K Integral of(B(t)dt/B(t)), was used as a means of assessing all segments. RESULTS: Mo(t)/B(t) showed a good linear correlation with Integral of(B(t)dt/B(t)) from 30 seconds to 4 minutes in all 456 segments. The mean K value of 8 LV segments was significantly lower after chemotherapy than before chemotherapy (0.071+/-0.019 [n = 21] vs. 0.095+/-0.025 [n = 36], P<.001). In 21 patients in whom dynamic SPECT was performed both before and after chemotherapy, the mean K values of left ventricle showed a significant decrease, from 0.101+/-0.024 to 0.071 +/-0.019 (P<.0001). The fractional change in the value of K after chemotherapy showed a significant linear correlation with the administered dose of doxorubicin (r = 0.648, P<.002). CONCLUSION: I-123 BMIPP dynamic myocardial SPECT may be clinically useful, because it permits the early detection of doxorubicin-induced cardiomyopathy.

Adult↗

In vitro evaluation of metabolic functions of a bioartificial liver.

The purpose of this study is to develop a bioartificial liver (BAL) with such a simple structure that it can be prepared within several hours and through which whole blood can be perfused as in current hemodialyzers. Hepatocytes were isolated from 37 pigs; each liver weighed 300 to 400 g. The average yield of hepatocytes was 2.4 +/- 0.6 x 10(10) cells per liver, with a cell viability of 89.6 +/- 3.9%. To prepare a BAL device, a cartridge, composed of hollow fibers made of cellulose diacetate was used. Nominal cut-off molecular weight of the hollow fibers was 68 kDa, and the internal diameter was 195 microm. One hundred milliliters of hepatocyte suspension, containing 1 x 10(10) cells, was inoculated into the inner space of the hollow fibers, and both the inlet and outlet of the hollow fiber cartridge were closed. It took only 3 hrs from administration of the pig's anesthesia to the start of an in vitro evaluation of the prepared BAL device. To evaluate the functions of this BAL quantitatively, using a pharmacokinetic method, a mixture of fresh human blood and Dulbecco's modified Eagle medium was circulated in the shell space of the hollow fibers at 200 ml/min. Chemicals (lidocaine, ammonia, and galactose) were then loaded into the perfusion medium. The average intrinsic clearance of the BAL device was found to be 46 ml/min for lidocaine and 8.8 ml/min for ammonia. The galactose elimination capacity of the BAL device was 1.34 mg/min. The metabolic function of the BAL device decreased by 81%, 49%, and 64% of the initial function for lidocaine, ammonia, and galactose, respectively, after 10 days of in vitro circulation.

Animals↗

Computed tomography in amyloid goiter.

Two cases of amyloid goiter showed diffuse decreased density of enlarged thyroid on CT. The diffuse decreased density of amyloid goiter on CT is thought to represent large amount of adipose tissue often found in amyloid goiter. When diffuse decreased density of the enlarged thyroid is recognized on CT, amyloid goiter should enter into differential diagnosis.

Adult↗

Thickened gastric walls showing diffuse low attenuation on CT.

Thickened gastric walls of diffusely low attenuation were observed on CT of three of eight patients with mucinous adenocarcinoma in a retrospective review of 141 cases of gastric carcinoma. On pathologic examination the low attenuation correlated with large amounts of mucin in the pathologic specimens. Mucinous adenocarcinoma with abundant mucin should be included in the differential diagnosis of thickened gastric walls of diffusely low attenuation.

Adenocarcinoma, Mucinous↗

CT diagnosis of catheter-induced septic thrombus of vena cava.

Two cases of septic thrombosis of the vena cava induced by central venous catheterization are reported. Computed tomography showed thrombi containing gas bubbles in the venae cavae; one involving the superior vena cava and the other the left-sided inferior vena cava. Computed tomography also demonstrated surrounding inflammatory infiltrations in the upper mediastinum or retroperitoneum.

Catheterization, Central Venous↗

The protective effect of pyrroloquinoline quinone and its derivatives against carbon tetrachloride-induced liver injury of rats.

Pyrroloquinoline quinone (PQQ) and its derivative, oxazo pyrroloquinoline (OPQ-G), protected rats from experimental liver injury induced by carbon tetrachloride (CCl4) in vivo. This effect was observed after an intraperitoneal injection of 5 mg/kg PQQ or OPQ-G, which was given twice, 10 min and 1 h before CCl4 administration. Pyrroloquinoline quinone protected primary cultured rat hepatocytes from CCl4 toxicity in vitro. This protection was most effective at a concentration of 3 mumol/L PQQ. Pyrroloquinoline quinone derivatives (oxazo pyrroloquinoline, methyl-thioethyl oxazo pyrroloquinoline and PQQ-allylester) also protected the hepatocytes from CCl4 toxicity. Pyrroloquinoline quinone and its derivatives inhibited the lucigenin-enhanced chemiluminescence from isolated hepatocytes initiated by CCl4. These results suggest that eliminating free radicals is one of the protective mechanisms of PQQ and its derivatives against CCl4-induced liver injury.

Acridines↗

Acute transverse myelitis caused by Coxsackie virus B5 infection.

A 6-year-old boy developed symptoms of rapidly progressive paraplegia, associated with bowel and urinary dysfunction, but without sensory loss. Magnetic resonance imaging (MRI) examination showed diffuse swelling of the lower spinal cord on T1-weighted images. Based on the clinical presentation and MRI findings, a diagnosis of acute transverse myelitis was made. The serum titer of neutralizing antibody against Coxsackie virus B5 rose from 1/4 on admission to 1/256 1 month later and Coxsackie virus B5 was isolated from stool samples. This case serves as a reminder that acute transverse myelitis can be a rare clinical manifestation of Coxsackie virus B5 infection.

Antibodies, Viral↗

Whole-body positron emission tomography and tumor marker CA125 for detection of recurrence in epithelial ovarian cancer.

We evaluated the clinical role of the combination of positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) and tumor marker CA125, in the detection of recurrence after initial therapy for epithelial ovarian cancer. The indication is the cases that cannot be confirmed the recurrence by conventional imaging modalities. Ninety patients underwent PET and computed tomography, including the measurement of specific tumor markers. FDG-PET confirmed recurrence in 46 patients (51%), and the recurrent site was confirmed by PET alone in 17 (37%). PET had high sensitivity for detecting both intraperitoneal and retroperitoneal metastases (93.9 and 92.9%, respectively). PET imaging was able to detect normal-sized metastases in the lymph nodes in 14 (50%) of the 28 patients with retroperitoneal metastasis. PET could show 87.5% positive rate of recurrent patients with asymptomatic rise of CA125 who had no sign of recurrence by conventional imaging methods. Of the 46 recurrent patients, 41 (89%) had specific elevated titers of CA125 at the first treatment. PET imaging was able to detect recurrence at relatively low titers (a median 68 U/mL) of CA125. In 8 (19.5%) of these 41 patients, recurrence with normal CA125 levels could be confirmed only by PET. The sensitivity of the combination of PET and CA125 was 97.8% with only one false-negative case. The combination of FDG-PET and CA125 titer is useful for the accurate detection of recurrence.

Adenocarcinoma↗

Whole-body positron emission tomography with F-18 fluorodeoxyglucose for the detection of recurrence in uterine sarcomas.

We evaluated the usefulness of whole-body positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG-PET) for the detection of recurrence in follow-up patients after primary treatment of uterine sarcoma. Eight patients with pathologically proven uterine sarcoma underwent FDG-PET, computed tomography (CT), and ultrasonography (US). Final diagnoses of recurrence were established in five cases (three carcinosarcomas and two leiomyosarcomas). PET revealed recurrent sites in the intraperitoneum, liver, lung, bone, and retroperitoneal lymph nodes. However, the minimum size of the tumor detected by PET depended on the sites of recurrence. CT and US images showed two false-negative cases of intraperitoneal tumors. PET was able to detect a solitary small intraperitoneal tumor, which was very difficult to detect by CT and US. Positive PET findings did not affect the prognosis in three of the five recurrent patients; however, the remaining two patients consequently underwent the combination therapy consisting of surgery and chemotherapy and survived for more than 1 year after the positive FDG-PET results. Application of PET imaging for the early detection of recurrent sites was useful for the decision of treatment strategy for patients with recurrent uterine sarcoma.

Adult↗