Relationship between autoantibodies against glutamic acid decarboxylase, thyroglobulin/thyroid microsome and DNA topoisomerase II in the clinical manifestation of patients with type 1 diabetes mellitus in Taiwan

OBJECTIVE: In a preliminary cross-sectional study, we discovered that DNA topoisomerase II autoantibodies (anti-TopII) were detected in 49.2% of 195 Chinese type 1 diabetes mellitus (type 1 DM) patients with a mean age of 14.5 years and a mean duration of disease of 4.6 years. In order to demonstrate the relationship between anti-TopII and other immunological characteristics in Chinese type 1 DM patients, and to evaluate its putative prediction efficacy in Chinese patients, we simultaneously examined the frequency of anti-glutamic acid decarboxylase autoantibodies (anti-GAD), anti-TopII, antithyroglobulin/antimicrosomal autoantibodies (ATA/AMiA) and C-peptide concentrations in our patients in the present study. DESIGN AND METHODS: The frequency of anti-GAD and C-peptide levels, anti-TopII, and ATA/AMiA were examined in our patients by radioimmunoassay, enzyme-linked immunosorbant assay and hemagglutination respectively. Univariate comparisons were performed using Student's t-test for normal distributed data and Chi-square test for diclomatous data. Multivariate analysis was used for interpreting the independent risk factors which increased the incidence of anti-TopII. RESULTS AND CONCLUSIONS: The positivities for anti-GAD, anti-TopII, ATA/AMiA and C-peptide were 45.8%, 50.2%, 13.4% and 11.4% respectively. Anti-GAD and anti-TopII frequencies in our patients were similar when we stratified the patients by age, age at onset and duration. These observations imply that anti-GAD and anti-TopII remain persistent in Chinese patients with long-term type 1 DM duration. The most interesting finding is that anti-TopII frequency is more persistent than anti-GAD in our patients, especially when the diabetic duration is longer than 11 years. This indicates that anti-TopII, rather than anti-GAD, might act as a better indicator for monitoring the pathogenesis of Chinese type 1 DM patients especially in patients with a long-standing duration of disease. The late age of onset (>18 years) is a risk factor which increased the incidence of anti-TopII according to multivariate analysis. We further analyzed different manifestations between the youth- and adult-onset type 1 DM and found that adult-onset type 1 DM is characterized by better preservation of residual beta-cell function and higher frequencies of autoantibodies.     

Mice immunized with DNA encoding a modified Pseudomonas aeruginosa exotoxin A develop protective immunity against exotoxin intoxication

A recombinant plasmid, which contains the Pseudomonas aeruginosa exotoxin A (PE) gene with a C-terminal deletion, was inserted into expression vector pSecTag Xpress. The expression of this bacterial exotoxin in an animal cell was first demonstrated in 3T3 cell by transient transfection and western blot assay. Recombinant plasmid DNA was then injected intramuscularly to BALB/c mice, anti-PE specific antibodies were found in all animals vaccinated with plasmid containing the PE gene and with 'detoxicated' recombinant PE protein. Mice vaccinated with DNA were protected from the intoxication of lethal dosage of P. aeruginosa exotoxin A. Our results indicated that mice vaccinated with DNA encoding the PE gene could express PE protein in vivo, induced specific immune response, and provided sufficient protective immunity that safeguarded mice from the injection of lethal dosage of PE toxin.     

Preclinical assessment of anti-CD40 Mab 5D12 in cynomolgus monkeys

Monoclonal antibody (Mab) 5D12 is a potent antagonist of the CD40-CD40L pathway. This cellular interaction has been validated in a large number of experimental animal models where dys-regulation of the immune system plays a role. Chimeric 5D12 (ch5D12) was constructed to reduce the potential immunogenicity and enhance the in vivo half-life when used in humans. ch5D12 is a molecularly engineered human IgG(4) antibody containing the variable domains of the heavy and light chains of the murine version of 5D12 (mu5D12). This new chimeric Mab was tested in a marmoset experimental autoimmune encephalomyelitis model and was shown to effectively prevent disease symptoms. The results of this in vivo evaluation supported clinical use of ch5D12 for immune targeted diseases. Therefore GMP material was prepared and a GLP-compliant tissue cross-reactivity study on human tissues (3 donors/37 tissues) and cynomolgus tissues (2 donors/37 tissues) was performed. ch5D12 stained on the surface of B cells and selected dendritic cells and no unexpected cross-reactivity was observed. The identical staining patterns in human and cynomolgus tissues justified the use of cynomolgus monkeys as a relevant model for humans. A GLP-compliant safety and tolerability evaluation for ch5D12 in cynomolgus monkeys was performed using the GMP produced material. Weekly administration of ch5D12 at two dose levels for 4 weeks was shown to be safe and without any side effects in all monkeys.     

Stereotactic radiosurgery for the treatment of dural arteriovenous fistulas involving the transverse-sigmoid sinus

OBJECT: The aim of this study was to assess the efficacy and safety of radiosurgery for the treatment of dural arteriovenous fistulas (DAVFs) located in the region of the transverse-sigmoid sinus. METHODS: A series of 20 patients with DAVFs located in the transverse-sigmoid sinus, who were treated with gamma knife surgery between June 1995 and June 2000, was evaluated. According to the Cognard classification, the DAVF was Type I in four patients. Type IIa in seven, Type IIb in two, and combined Type IIa+b in seven. Nine patients had previously been treated with surgery and/or embolization, whereas 11 patients underwent radiosurgery alone. Radiosurgery was performed using multiple-isocenter irradiation of the delineated DAVF nidus. The target volume ranged from 1.7 to 40.7 cm3. The margin dose delivered to the nidus ranged from 16.5 to 19 Gy at a 50 to 70% isodose level. Nineteen patients were available for follow-up review, the duration of which ranged from 6 to 58 months (median 19 months). Of the 19 patients, 14 (74%) were cured of their symptoms. At follow up, magnetic resonance imaging and/or angiography demonstrated complete obliteration of the DAVF in 11 patients (58%), subtotal obliteration (95% reduction of the nidus) in three (16%), and partial obliteration in another five (26%). There was no neurological complication related to the treatment. One patient experienced a recurrence of the DAVF 18 months after angiographic confirmation of total obliteration, and underwent a second course of radiosurgery. CONCLUSIONS: Stereotactic radiosurgery provides a safe and effective option for the treatment of DAVFs involving the transverse and sigmoid sinuses. For some aggressive DAVFs with extensive retrograde cortical venous drainage, however, a combination of endovascular embolization and surgery may be necessary.     

The influences of blood glucose and duration of fasting on myocardial glucose uptake of [18F]fluoro-2-deoxy-D-glucose

During the study of chest using positron emission tomography (PET) with [18F]fluoro-2-deoxy-d-glucose (FDG), a significant myocardial FDG uptake can prevent detection of the lesion that is located either behind or closely attached to the heart border. Two well-known and possible factors of myocardial FDG uptake are blood glucose level and fasting duration before FDG PET scanning. This study investigates whether the two factors are related to myocardial FDG uptake. Our study also explores the possibility of eliminating myocardial FDG uptake by controlling patients' blood glucose level and/or fasting duration. Whole-body FDG PET scans performed on 270 consecutive patients performed were reviewed. The study subjects were classified into four grades of myocardial FDG uptake according to the visual interpretation of the FDG PET image hard-copy films. For all study subjects, the blood sugar level and fasting duration before FDG injection were recorded. Then, the blood sugar levels and fasting duration were compared to the visual grade of myocardial FDG uptake for each study subject. About half of the study subjects showed graded 0 myocardial FDG uptake when the blood glucose levels were < or = 120 mg x dl(-1) or when the fasting duration was between 5 and 12 h. One hundred and thirty-one of the 142 (92%) patients with graded 0 uptake were asked to fast for > or = 4 h and had blood glucose levels < or = 120 mg x dl(-1). Based on our findings, we conclude that controlling the patients' blood glucose levels to < or = 120 mg x dl(-1) and at least 5 h fasting should be recommended to decrease myocardial FDG uptake.     

Evidence of gallbladder function changes in hepatoma after transcatheter arterial embolization by quantitative Tc-99m DISIDA cholescintigraphy

BACKGROUND/AIMS: Transcatheter arterial embolization is the treatment of choice for inoperable hepatocellular carcinoma. Gallbladder infarction following transcatheter arterial embolization has been reported, therefore, the gallbladder functions were studied using the quantitative Tc-99m DISIDA cholescintigraphy in the present study. METHODOLOGY: The gallbladder functions which were presented as the filling fraction and the ejection fraction in 24 patients with hepatoma before and after transcatheter arterial embolization. The patients were separated into two groups. Group 1: 12 patients received precystic artery transcatheter arterial embolization and group 2: 12 patients received postcystic artery transcatheter arterial embolization. RESULTS: After transcatheter arterial embolization, significantly decreased both gallbladder functions of filling fraction (61.2 +/- 7.4% and 48.3 +/- 6.5%) and ejection fraction (47.8 +/- 6.0% and 36.5 +/- 5.3%) were found in group 1 patients. However, no significant change of filling fraction (59.0 +/- 5.0% and 58.8 +/- 7.4%) and ejection fraction (49.9 +/- 2.4% and 49.3 +/- 5.7%) in group 2 patients. CONCLUSIONS: Impaired gallbladder functions were common in hepatoma patients who received precystic artery transcatheter arterial embolization, and Tc-99m DISIDA cholescintigraphy may be useful for evaluating the gallbladder functions in hepatoma patients who received transcatheter arterial embolization.     

Plasma antioxidant vitamins, chronic hepatitis B virus infection and urinary aflatoxin B1-DNA adducts in healthy males

Epidemiological evidence indicates that aflatoxin B1 (AFB1) intake is associated with an increased risk of hepatocellular carcinoma (HCC). The hepatocarcinogenesis is initiated by covalent binding of AFB1 to cellular DNA. To determine whether nutritional factors and hormonal status may influence the binding of AFB1 to hepatic DNA, a cross- sectional study was performed on a total of 42 male asymptomatic hepatitis B surface antigen (HBsAg) carriers and 43 male non-carriers in a cohort study on the multistage development of HCC in Taiwan. The major AFB1-DNA adduct in vivo, AFB1-N7-guanine, was measured by high- performance liquid chromatography in urine. Urinary AFB1-N7-guanine was detectable in 40% of the subjects. HBsAg carriers had a higher detection rate of urinary AFB1-DNA adducts than non-carriers and the difference was statistically significant after multivariate adjustment. After taking into account the total AFB1 urinary metabolite level, chronic HBsAg carrier status, and other potential confounders, plasma levels of cholesterol, alpha-tocopherol, and alpha- and beta-carotene were positively associated with the detection rate of the AFB1-DNA adducts in a dose-dependent manner, whereas plasma lycopene level was inversely related to the presence of the adducts in urine. The association of urinary AFB1-DNA adducts with the plasma levels of cholesterol, alpha-tocopherol, lycopene, and alpha- and beta-carotene was observed at both low and high exposure levels of AFB1. There was a synergistic interaction of plasma alpha-tocopherol with alpha- and beta- carotene on the adduct levels. No association with the adducts was found for plasma levels of retinol and testosterone. This study demonstrated different associations of antioxidant vitamins with AFB1- DNA adduct formation. The data consistent with our previous finding in cultured woodchuck hepatocytes that alpha-tocopherol and beta-carotene enhanced AFB1-DNA adduct formation suggest that prospective investigation of the relationship between plasma micronutrients and risk of AFB1-related HCC is warranted.      

Pharmacology of scorpion toxin II in the skeletal muscle

1. Scorpion toxin II is potent in inducing contracture and spontaneous contractions of the chick biventer cervicis muscle. In addition, this toxin induces membrane depolarization and blockade of neuromuscular transmission in this muscle preparation. The purpose of the present study is to explore the possible mechanism of actions of toxin II. 2. The muscle contracture induced by toxin II is moderately accelerated by Ca2+-free Krebs solution, delayed by high Ca2+ (10 mM), high Mg2+ (10 mM) and low Na+ (60mM) Krebs solution. Moreover, this action is inhibited slightly by d-tubocurarine and completely by either procaine or tetrodotoxin, but unaffected by beta-bungarotoxin. All these findings suggest that toxin II induces contracture mainly by increasing the Na+ permeability of the muscle membrane. 3. Spontaneous contractions induced by toxin II are abolished by Ca2+-free Krebs solution, inhibited partially by either d-tubocurarine or beta-bungarotoxin and completely by tetrodotoxin or procaine. These results suggest that toxin II induces spontaneous contractions partially by releasing acetylcholine from nerve endings and partially by increasing the Na+ permeability of the muscle membrane.     

Intrapartum spontaneous uterine rupture following uncomplicated resectoscopic treatment of Asherman's syndrome

Since Asherman first published his series of intrauterine synechiae in 1948, only a few physicians have described the obstetric complications of patients who conceived following surgical treatment of intrauterine synechiae. We present a woman with a history of resectoscopic resection of intrauterine adhesions with a term pregnancy and spontaneous uterine rupture that occurred during the intrapartum period. At emergent cesarean section, hemoperitoneum of approximately 1500 mL was noted and a 10-cm defect was present in the lateral uterine wall; the edges of the defect were bleeding actively. Because of the potential for a disastrous outcome in the rupture of the pregnant uterus, patients treated for Asherman's syndrome should be identified early and appropriate precautions should be taken in their obstetric management.     

Toward normal perfusion after radiosurgery: perfusion MR Imaging with independent component analysis of brain arteriovenous malformations

BACKGROUND AND PURPOSE: Brain perfusion is disturbed by cerebral arteriovenous malformations (AVMs). Our study was conducted to determine the radiosurgical effects on this disturbed perfusion. METHODS: MR perfusion imaging with independent component analysis was performed in five healthy subjects and 19 patients with AVM before and after radiosurgery (every 6 months up to 2 years). Perfusion map relative cerebral blood volume (rCBV), cerebral blood flow (rCBF), and mean transient time (rMTT) were assessed. Regions of interest (ROIs) on AVM target sections were defined as follows: N, AVM nidus; H, the rest of the ipsilateral hemisphere; P, immediately posterior to the nidus; A, immediately anterior to the nidus; Ar, anterior remote; Pr, posterior remote. Similar ROIs in the contralateral hemisphere (N1, H1, P1, A1, Pr1, and Ar1) served as internal references. Perfusion ratios of ROI-ROI1 were defined. Nonparameteric Mann-Whitney U tests and generalized linear models were used for statistical analysis. RESULTS: Before radiosurgery, patients' H/H1 rCBV and rCBF ratios were significantly higher than those of healthy subjects (P < .005), indicating AVM steal. Three types of perilesional perfusion disturbance were observed. From the first postradiosurgical follow-up at 6 months, N/N1 rCBV and rCBF ratios gradually decreased to 1.0 (both P < .001), whereas rMTT ratios gradually increased to 1.0 (P < .015); H/H1, A/A1, and P/P1 rCBV and rCBF ratios decreased after radiosurgery (P < .005), indicating reversal of steal toward normal perfusion. CONCLUSION: Initial high transnidal flow and perinidal perfusion disturbances were demonstrated. They gradually changed toward normal perfusion after radiosurgery. This explains, in part, the pathophysiologic factors of AVM and therapeutic effects.