Clinicopathological characteristics of myelodysplastic syndromes with del(5q) in Taiwan

BACKGROUND

Myelodysplastic syndromes (MDS) are a group of clonal haematopoietic stem cell disorders characterised by ineffective haematopoiesis and cytopenia. Studies have reported differences in MDS between Asian and Western countries, but data from Taiwan are scarce.

MATERIALS AND METHODS

In this study we analysed the clinical and pathological features of 32 Taiwanese MDS patients with del(5q) (ie, del(5q) alone [Group A, n = 11], del(5q) with one additional cytogenetic abnormality other than monosomy 7 or del(7q) [Group B, del(5q)+1; n = 6], and del(5q) with ≥2 additional cytogenetic abnormalities [Group C, n = 15]).

RESULTS

Progression-free survival (PFS) and overall survival (OS) were more favourable for Group A than for Groups B (p < 0.05) and C (p ≤ 0.001). Multivariate analysis showed that age >70 years, thrombocytopenia, and karyotype other than del(5q) alone were poor prognostic factors. Among the patients that had World Health Organization (WHO)-defined MDS with isolated del(5q), one patient (9%) had a typical marrow morphology of 5q minus syndrome with erythroid hypoplasia and four patients (36%) had hypolobated megakaryocytes. In addition, PFS and OS were significantly more favorable for the patients with del(5q) alone than for those with del(5q)+1 (p < 0.05).

CONCLUSION

The bone marrow morphology, clinical features, and prognosis of Taiwanese MDS patients with del(5q) were different from those associated with MDS with isolated del(5q) as defined in the current WHO classification. Researchers should compare different geographic regions and racial populations to determine whether geographic and racial differences exist with respect to MDS with del(5q).

[Research advances on the prevention and treatment of burn infection in the elderly]

Infection is a common complication after burns and the major cause of death in patients suffering severe burn injury. The infection of the elderly after burns is more serious due to their decreased immune function that is complicated with factors such as multiple chronic diseases and dysfunction of various organs. In addition, the burn infection in the elderly lacks the specific symptoms and signs, which brings great challenges to its diagnosis and treatment. To effectively prevent and control infection is very important for the treatment of elderly burn patients. Combined the clinical characteristics of burn infection in the elderly, this paper summarized the research advances of prevention and treatment for burn infection in the elderly from fluid resuscitation, wound treatment, antibiotic using, organ protection, nutritional support, and infection prevention, aiming to provide reference for clinical practice.

Novel halogen-free flame retardants based on adamantane for polycarbonate

The surface of PC/FR compositions presents a continuous and protective carbon layer with several bubbles and folds.

[Research and development of Lipin family.]

Lipin family including at least three members Lipin 1, Lipin 2, and Lipin 3 is a critical regulatory enzyme identified recently, which plays dual roles in lipid metabolisms. Lipin family has physiological effects not only on regulating lipid metabolism, but also on maintaining normal peripheral nervous functions, liver lipoprotein secretion, cell morphous, reproductive functions, and energy homeostasis. Since mutations in Lipin gene express may be associated with AIDS, insulin resistance, obesity, diabetes mellitus, and the other diseases of metabolic syndrome, Lipin may be a new useful target in treatment of above-mentioned clinical-related diseases. In this article, we focused on discovery, construction features, expression, regulatory mechanism, and biological functions of Lipin, as well as its correlation research with clinical-related diseases.

Single-walled carbon nanotube based pH sensors on a flexible parylene-C substrate

In this paper, we present a suspended Single-Walled Carbon Nanotube (SWNT) based pH sensor utilizing a low temperature Dielectrophoretic (DEP) assembly process on a flexible parylene-C substrate. Parylene-C, a light weight, flexible and inert material, is compatible with many microfabrication processes. Furthermore, utilizing parylene-C as a flexible substrate, one can readily create a suspended microplatform utilizing an O2 plasma etch process. Suspended nanobridges have larger exposed surface areas and may potentially have enhanced sensitivity for sensing applications. Fabricating these structures on a thin (10 microm) parylene-C substrate allows their utilization as flexible devices or in wearable sensor applications. We have successfully assembled suspended SWNT nanobridges across a spacing of 4 microm. The electrical characterization results from the assembled SWNTs yield ohmic behavior with a measured two-terminal resistance of approximately 17Komega. Furthermore, the conductometric measurements of the SWNT sensors have demonstrated that corresponding to an increase in pH value, the resistance of SWNTs has decreased due to the OH- group that attached on to the wall of the SWNTs and changed the electrical properties of the SWNTs. These novel suspended nanostructures can be used as potential candidates in nanosensor applications.

Increasing TB case detection through intensive referral of TB suspects by village doctors to county TB dispensaries

OBJECTIVE

To explore new approaches to increase the detection of tuberculosis cases (TB).

DESIGN

Thirty counties participated in the study. Patients with TB symptoms were surveyed and referred by trained village doctors to county dispensaries, designated township health centres or general hospitals for free sputum examination. TB patients and suspects notified by general hospitals were traced by TB staff if they defaulted during the transfer.

RESULTS

A total of 12,091 new smear-positive TB cases were detected. The registration rate of new smear-positives increased from 36.2 per 100,000 population before the project to 49.9/100,000 after the project, and the case detection rate under the DOTS strategy reached 86%. Of 43,464 registered TB suspects, 15,363 (35.3%) were referred by village and hospital doctors. The referral rate increased significantly (P < 0.01). Of the 15,363 referred patients, 3870 were diagnosed as new smear-positive TB cases. Among three different microscopy centres, there was a statistically significant difference in the sputum examination rates of TB suspects and in the smear-positive rates among the suspects examined. The follow-up rate was 70.9%, but the follow-up success rate was only 33.1%.

CONCLUSIONS

Intensive referral of patients with TB symptoms by village doctors to TB dispensaries is an effective way of increasing detection. At the same time, incentives are necessary for patients and village doctors.

Toxicity assessment of polycyclic aromatic hydrocarbons using an air-tight algal toxicity test

The existing toxicity data on the effects of polycyclic aromatic hydrocarbons (PAHs) on Pseudokirchneriella subcapitata (green alga) are quite insufficient. These data were derived using different test techniques (e.g. conventional batch test, closed-system test, semi-static test). The relative toxicity relationship for various PAHs is thus difficult to interpret. Consequently, the current toxicity database is insufficient and also inadequate for analyses of the effects of PAHs on P. subcapitata. This study evaluated the toxicity of eleven PAHs using an air-tight test technique. The relative toxicity relationship was determined on a uniform basis, and was different from the relationship based on current available data. P. subcapitata. was found to be more susceptible to PAHs than Daphnia magna, fathead minnow, and Scenedesmus subspicatus. Quantitative structure-activity relationship (QSAR) was established based on the chemical's hydrophobicity with R(2) equal to 0.88. Photo-induced toxicity for various PAHs was also explored by exposing PAHs under UV-photoactivation. Toxicity of anthracene, benzanthrone, and benzo[a]anthracene was found to increase 3.5 to 25 times after UV exposure. Phototoxicity was observed when the HOMO-LUMO gap varied between 6.8 and 8.0 eV.

Mucopolysaccharidosis type VI: Report of two Taiwanese patients and identification of one novel mutation

Mucopolysaccharidosis type VI (MPS VI) is an autosomal recessive lysosomal storage disease caused by a deficiency of N-acetylgalactosamine-4-sulphatase (arylsulfatase B, ASB). We report the clinical investigation and mutation analysis of two Taiwanese patients with severe (Case 1) and intermediate (Case 2) phenotypes of MPS VI. Three missense mutations and one polymorphism were identified. Case 1 was found to have a novel heteroallelic C-to-G transversion at nucleotide 1197 causing a phenylalanine to leucine substitution at residue 399 (Phe399Leu), and a heteroallelic Gln239Arg mutation. In Case 2, a heterozygous Cys192Arg mutation and a Val358Met polymorphism were identified. Among these three mutations, the Gln239Arg and Phe399Leu substitutions have so far been observed only in the Taiwanese population. The correlation between genotype and phenotype contributes to molecular pre- and post-natal diagnosis for MPS VI patients.

Intramedullary spinal cryptococcoma: a case report

Intramedullary spinal cryptococcosis is very rare. We describe a case of intramedullary spinal cryptococcoma at the T12 level in a 60-year-old man who presented with a 3-month history of progressive bilateral lower limb weakness and no obvious immunocompromise. Magnetic resonance (MR) imaging revealed a 1.2 cm diameter mass within the spinal cord at T12 with intermediate signal intensity on T1-weighted images, a slight degree of homogeneous low signal intensity on T2-weighted images, and intense enhancement after infusion of gadopentetate dimeglumine. These findings led to a preoperative diagnosis of intramedullary tumor. After 2 months of postoperative antifungal treatment, the patient's clinical condition had markedly improved. Cryptococcoma should be considered when an enhancing lesion of the spinal cord is found on MR imaging, even in apparently immunocompetent patients. A careful lumbar puncture for cerebrospinal fluid analysis to diagnose cryptococcosis of the central nervous system should be made promptly, as early treatment is associated with a good prognosis.

Adsorptive behavior and electrochemical determination of the anti-fungal agent ketoconazole

The adsorptive properties and electrochemical behavior of ketoconazole, an oral anti-fungal agent, are demonstrated at a glassy carbon electrode. The adsorption of the compound obeys the Frumkin isotherm with an interaction factor (alpha) of 0.985 and adsorptive coefficient (beta) of 1.98 x 10(6) L mol(-1). The Gibbs energy of adsorption (deltaG) is -3.59 x 10(4) J mol(-1) at 25 degrees C. A very sensitive electroanalytical method has been developed for determination of the drug with a detection limit of 4.0 x 10(-11) mol L(-1). Relationships between stripping current and concentration of ketoconazole were linear in the range 10(-6)-10(-10) mol L(-1) with different preconcentration periods. The method has been used to measure the ketoconazole content of tablets.

In vivo proton MR spectroscopy of chorea-ballismus in diabetes mellitus

The most common cause of chorea-ballismus (CB) is a vascular lesion; it is also associated with nonketotic hyperglycaemia in diabetes mellitus (DM) and may be the first manifestation of this disorder. We describe the CT, MRI and proton MR spectroscopy (1H-MRS) of CB in eight patients. Six had hemichorea-hemiballismus (HC-HB) and two bilateral CB. Single-voxel (SV) 1H-MRS was performed using point-resolved spectroscopy (PRESS). Voxels were positioned in the basal ganglia of the patients and control subjects. PRESS was also used to obtain spectroscopic imaging (1H-MRSI) of the slice of interest in two patients. CT showed a slightly dense striatum in all the patients with CB, and T1-weighted images revealed high signal. The CB correlated well with the neuroimaging findings. SV 1H-MRS showed the mean (+/- SD) N-acetylaspartate (NAA)/ creatine (Cr) ratio to be 1.45 +/- 0.19 in HC-HB and 1.82 +/- 0.06 on the opposite normal side (P = 0.01). The choline (Cho)/ Cr ratio was 1.3 +/- 0.12 in HC-HB and 1.11 +/- 0.13 on the opposite normal side (P = 0.005). A lactate peak was seen in seven patients. The NAA/Cr ratio was 1.44 +/- 0.15 in bilateral CB and 1.74 +/- 0.16 in the controls (P = 0.017); the Cho/Cr ratios were 1.36 +/- 0.1 and 1.19 +/- 0.07 (P = 0.015). The low NAA/Cr suggests neuronal loss or damage and the high Cho/Cr probably indicates gliosis. The presence of lactate may suggest mild ischaemia due to acute vascular events during hyperglycaemia and underlying chronic focal cerebrovascular diseases in DM.

Protection of salvia miltiorrhiza against aflatoxin-B1-induced hepatocarcinogenesis in Fischer 344 rats dual mechanisms involved

Extract of Salvia Miltiorrhiza (SM) has been widely used in traditional Chinese medicine for treating liver diseases. Recent experimental evidence indicates that it has anti-tumor potential. In this study, the effect of SM on alfatoxin B1 (AFB1)-induced hepatocarcinogenesis was investigated in male Fischer 344 rats. AFB1 (40 microg/100 g body wt, by gavage) was administered once a week for 24 weeks. In SM treatment group, rats were given SM (0.25g/100g body wt, 5 days/week by gavage) for a total of 28 weeks, including 4 weeks before and 24 weeks during AFB1 exposure. Results showed that the elevation of serum alanine aminotransferase and aspartate aminotransferase activities due to AFB1 dosing was almost completely abolished by the treatment of SM, indicating that SM could prevent AFB1-induced liver cell injury. It was further observed that SM substantially reduced glutathione S-transferase placenta form (GST-P) positive foci formation and GST-P mRNA expression caused by AFB1, which clearly suggests that SM is effective in preventing AFB1-induced hepatocarcinogenesis. Furthermore, the inhibition on AFB1 hepatocarcinigenesis was associated with a corresponding decrease in AFB1-DNA adducts formation as well as AFB1-induced oxidative DNA damage (8-hydroxydeoxyguanosine) in rat liver. Our results also indicate that the protective effect of SM might be mediated through dual mechanisms: (i) the enhancement of AFB1 detoxification pathway, especially the induction of GST-Yc2 mRNA expression, and (ii) the antioxidant property of SM.

Mutation analysis of Crouzon syndrome and identification of one novel mutation in Taiwanese patients

BACKGROUND

Crouzon syndrome is an autosomal dominant disorder causing premature fusion of the cranial suture. Mutations have been reported in exon IIIa or IIIc of the fibroblast growth factor receptor 2 (FGFR2) gene.

METHODS

In the present study, nine unrelated Crouzon syndrome patients were screened for mutations in the two exons of FGFR2 by polymerase chain reaction and direct sequencing.

RESULTS

Mutations were detected in 67% (6/9) of all cases. More than half the studied Crouzon patients carried a mutation resulting in either the loss or gain of a cysteine residue. A novel mutation, Tyr281Cys substitution, was discovered at exon IIIa.

CONCLUSIONS

The mechanisms by which the same genotypes cause different phenotypes for each type of craniosynostosis syndrome in still uncertain. However, the molecular identification of the FGFR gene has made a great impact on the clinical classification of craniosynostosis syndromes; a new classification based on genotypes seems to be unavoidable.

Detection of Kaposi sarcoma-associated herpesvirus in bone marrow biopsy samples from patients with multiple myeloma

BACKGROUND

Kaposi sarcoma-associated herpesvirus (KSHV) recently has been identified in the bone marrow (BM) dendritic cell of multiple myeloma (MM) patients. However, whether or not KSHV is associated with MM remains controversial because many studies have failed to detect the presence of KSHV DNA sequences in the BM of their MM patients.

METHODS

We have assayed for KSHV DNA sequences in the BM biopsy samples from 49 patients with MM and from 8 patients with normal BM, using nested polymerase chain reaction and dot blot analysis. The polymerase chain reaction product of KSHV was further determined by single-strand conformation polymorphism and sequence analyses.

RESULTS

KSHV DNA was detectable in 22 of 49 patients (44.9%) with MM but was not detectable in normal BM cells. Single-strand conformation polymorphism and sequence analyses showed that there were interpatient specific mutations. Sixteen out of 22 KSHV DNA sequences belonged to a previously defined subgroup, and the other 6 remain unclassified and may represent distinct strains of KSHV in Taiwan.

CONCLUSIONS

Data strongly supported that KSHV infection did exist in the BM of the current study patients with MM. However, the role of KSHV in the pathogenesis of multiple myeloma remains to be determined.

Molecular analysis of Wilson disease in Taiwan: identification of one novel mutation and evidence of haplotype-mutation association

Wilson disease (WND) is caused by a deficiency of the copper-transporting enzyme, P-type ATPase (ATP7B). Twelve different mutations have previously been identified in Taiwan Chinese with Wilson disease. We, herein, report another 4 missense mutations, 1 of which is novel. We did haplotype analysis of Taiwanese WND chromosomes, using three well characterized short tandem repeat markers (haplotype was assigned in the order of D13S314-D13S301-D13S316). Association correlation was found between the mutations and their respective haplotypes. Haplotype-deduced pedigree analysis was shown to be helpful in the mutation analysis of WND chromosomes and in the molecular assessment of both pre-symptomatic WND patients and carriers. Given the complexity and heterogeneity of the mutation spectrum of ATP7B, we suggest that haplotype analysis should be performed before full-scale mutation analysis.

Superoxide radical-initiated apoptotic signalling pathway in selenite-treated HepG(2) cells: mitochondria serve as the main target

The exact role of superoxide radicals (O(2)(*)(-)) in apoptosis is still a matter of debate. The main objective of the present study is to evaluate the apoptotic signalling pathway initiated by O(2)(*)(-). The reductive reaction of sodium selenite with glutathione was used as the intracellular O(2)(*)(-)-generating system. When cells were exposed to 5 to 25 microM selenite, a temporal pattern of apoptotic events was observed following the elevation of O(2)(*)(-), in which cytochrome c release and mitochondrial depolarization preceded caspase-3 activation and DNA fragmentation. The simultaneous treatment with N-acetylcysteine and 4-hydroxy-2,2,6, 6-tetramethylpiperidine-N-oxyl markedly reduced O(2)(*)(-) level and suppressed the mitochondrial changes and the downstream apoptotic events. Moreover, pretreatment with cyclosporin A plus trifluoperazine, two mitochondrial permeability transition (MPT) inhibitors, was capable of attenuating O(2)(*)(-)-mediated cytochrome c release and mitochondrial depolarization, and subsequently inhibiting apoptosis. Thus, the present results provide convincing evidence that O(2)(*)(-) generated from the reductive reaction of selenite with GSH is capable of triggering a mitochondria-dependent apoptotic pathway. Such knowledge may not only help to obtain a better understanding of the apoptotic effect of selenite per se, but of the role of O(2)(*)(-) in initiation and execution of apoptosis.

Non-point pollution from China's rural areas and its countermeasures

Most lakes in the eastern part of China are eutrophic and non-point pollution accounts for more than half of the nutrient load to the lakes and reservoirs. Some efforts have been made to reduce the non-point source pollution in the catchments of sensitive water bodies. Technologies for the control of non-point pollution in Chinese rural areas are multipond systems, biogas fermentation, hilly area ecological agriculture, constructed wetlands, ecotone engineering and others. They are effective in the removal of nutrients from the runoff water or reduction of waste, and they are used with multi-purposes. To control non-point pollution, the cooperation with farmers and other residents in the countryside is the key to success, and the program has to consider their benefits. There are still many difficulties with its control, and more efforts are needed to develop suitable technologies and environmental education.

Pathologic studies of fatal cases in outbreak of hand, foot, and mouth disease, Taiwan

In 1998, an outbreak of enterovirus 71-associated hand, foot, and mouth disease occurred in Taiwan. Pathologic studies of two fatal cases with similar clinical features revealed two different causative agents, emphasizing the need for postmortem examinations and modern pathologic techniques in an outbreak investigation.

Inhibition of ebselen on aflatoxin B(1)-induced hepatocarcinogenesis in Fischer 344 rats

Aflatoxin B(1) (AFB(1)), a potent hepatocarcinogen, enhances ROS formation and causes oxidative DNA damage, which may play a role in its carcinogenicity. We have demonstrated recently that ebselen, an organic selenium compound, protects against the cytotoxicity of AFB(1) through its antioxidant capability. The present study was designed to investigate the effect of ebselen on AFB(1)-induced hepatocarcinogenesis in an animal model. Fischer 344 rats were first treated with either deionized water or ebselen (5 mg/kg, 5 days/week) via gavage for 4 weeks, then given AFB(1) (0.4 mg/kg, gavage, once a week) or AFB(1) plus ebselen (5 mg/kg, 5 days/week) for another 24 weeks. The results showed that the hepatocarcinogenicity of AFB(1) in rats was significantly reduced by ebselen treatment as indicated by a decrease in: (i) serum gamma-glutamyl transpeptidase activity; (ii) expression of mRNAs of liver alpha-fetoprotein and the placental form of glutathione S-transferase (GST-P); and (iii) the area and mean density of staining of liver GST-P foci. Ebselen treatment significantly reduced the formation of hepatic AFB(1)-DNA adducts and 8-hydroxydeoxyguanosine caused by AFB(1) exposure. These findings suggest that ebselen can inhibit the carcinogenicity of AFB(1). In addition to the reduction of AFB(1)-DNA adduct formation, the protective effect of ebselen against AFB(1)-induced oxidative DNA damage may also, at least in part, contribute to its anticarcinogenic property.

Carpal tunnel syndrome caused by tophaceous gout: CT and MR imaging features in 20 patients

OBJECTIVE

The objective of this study is to describe the CT and MR imaging findings of gouty tophi in the wrist and present this entity as a cause of carpal tunnel syndrome.

MATERIALS AND METHODS

Retrospective review of the CT (n = 18) and MR imaging (n = 20) studies of the wrist in patients with a documented diagnosis of gout who presented with gout-related carpal tunnel syndrome was performed; images of 24 wrists were collected over a 5-year period. Patient population included 20 men, who ranged in age from 35 to 76 years. All images were reviewed by two musculoskeletal radiologists who reached a consensus opinion. Surgical correlation was available in 12 patients.

RESULTS

Tophi were found in the floor of the carpal tunnel (n = 18), carpal bones (n = 17), radiocarpal joint (n = 17), and extensor tendons or tendon sheaths (n = 16) of the wrist. All tophi showed similar signal characteristics (from low to intermediate signal intensity on T1-weighted images with heterogeneous signal intensity on T2-weighted images) with the exception of tophi in the floor of the carpal tunnel (low signal intensity on T2-weighted images). Varying degrees of calcification were noted on CT and MR imaging studies. Gadolinium-enhanced MR studies showed heterogeneous enhancement.

CONCLUSION

Gouty tophi should be entertained as a cause of carpal tunnel syndrome in the appropriate patient population. Familiarity with this entity and its imaging characteristics may prove helpful in diagnosis and preoperative planning.

Intracellular thiol depletion causes mitochondrial permeability transition in ebselen-induced apoptosis

Ebselen, a selenoorganic compound, has recently been shown to display a novel property of inducing apoptosis through rapid depletion of intracellular thiols in human hepatoma cells, HepG(2). The present study was thus designed to explore the mechanism of how ebselen triggers apoptosis upon depletion of intracellular thiols. The results demonstrated that ebselen treatment triggered mitochondrial permeability transition rather rapidly as revealed by redistribution of calcein green fluorescence from cytosol into mitochondria. Ebselen treatment also caused a dose- and time-dependent loss of mitochondrial membrane potential (MMP) and release of cytochrome c. Pretreatment with N-acetylcysteine, a precursor of intracellular reduced glutathione (GSH) synthesis, significantly attenuated the ebselen-induced MMP disruption and subsequently inhibited the apoptosis. In contrast, pretreatment with buthionine sulfoximine, a specific inhibitor of intracellular GSH synthesis, significantly augmented the ebselen-induced MMP alteration, and enhanced the apoptosis. Although ebselen treatment significantly increased the intracellular superoxide radical and calcium concentrations, superoxide dismutase, and BAPTA (a calcium chelator), however, failed to prevent ebselen-induced MMP loss and apoptosis. Neither caspase-9 nor caspase-3 activation was detected in ebselen-treated cells. Z-VAD-FMK, a general caspase inhibitor, also had no effect on ebselen-induced MMP decrease and apoptosis. The overall findings thus suggest that mitochondrial permeability transition resulted from intracellular thiol depletion is a critical event in ebselen-induced apoptosis.

Effect of strenuous arm exercise on oxidized-LDL-potentiated platelet activation in individuals with spinal cord injury

This study investigates how strenuous arm exercise affects oxidized-low density lipoprotein (O(X)-LDL) mediated-platelet activation in patients with SCI. Ten patients with SCI and ten age- and sex-matched healthy subjects exercised strenuously using an arm crank ergometer. The following measurements were taken both when the subjects were at rest, and immediately after exercise: plasma lipid profile, O(X)-LDL mediated platelet aggregability and [Ca(2+)]i, urinary 11-dehydro-thromboxane B2 (11-dehydro-TXB2) and 8-iso-prostaglandin F(2alpha), (8-iso-PG F(2alpha)) contents, and plasma NO metabolite (nitrite plus nitrate) level. Based on these measurements, the major findings of this study can be summarized as follows: 1) the SCI group had higher urinary 8-iso-PGF(2alpha) and 11-dehydro-TXB2 contents, but a lower plasma nitrite plus nitrate level than the control group; 2) at rest, the SCI group had a higher platelet aggregability and [Ca(2+)]i, and O(X)-LDL-potentiated platelet activation than the control group; 3) O(X)-LDL-potentiated platelet aggregation was enhanced by strenuous arm exercise in both groups, but the effect of exercise was more pronounced in the SCI group than in the control group; 4) treating the platelet with L-arginine inhibited O(X)-LDL-potentiated platelet activation in both groups. The study concludes that individuals with SCI had more extensive resting and exercise-enhanced O(X)-LDL-potentiated platelet activation and greater amounts of preformed lipid peroxides than those without SCI. Therefore, supplementation therapy with antioxidants may be needed for patients with SCI, especially in a strenuous arm exercise period.

Mutation analysis of Wilson disease in Taiwan and description of six new mutations

Wilson disease is an autosomal recessive disorder of copper metabolism. Mutation screening in Wilson disease has led to the detection of at least 89 disease-specific mutations. Some mutations appear to be population specific, while others are common to many populations. In this study, 38 Taiwanese patients with Wilson disease were screened using single-strand conformation polymorphism analysis, followed by direct DNA sequencing. We found 12 different mutations, six of which were novel. All our detected mutations were found to be in eight exons. Four mutations in three loci (Arg778Gln, Arg778Leu, Gly943Asp, and Pro992Leu) accounted for about 58% of the mutant alleles we detected. Using an RNA transcriptional assay, we confirmed that both of our detected splice-site mutations resulted in exon skipping.

Unusual signs for dural arteriovenous fistulas with diffuse basal ganglia and cerebral calcification

We present a case of multiple dural arteriovenous fistulas (AVFs) in a 60-year-old man with the chief complaint of worsening headache, altered mental status and progressively unsteady gait over the course of one year. Computerized tomography revealed diffuse, symmetric calcification in the bilateral basal ganglia and bilateral periventricular and subcortical white matter. Magnetic resonance imaging revealed multiple, enhanced, punctate and linear vessels. These images were due to reflux into the parenchymal veins in the dural AVF of the superior sagittal sinus within the basal ganglia and deep white matter of both cerebral hemispheres. Cerebral angiography disclosed multiple dural AVFs. The exact mechanism of basal ganglia and subcortical calcification is proposed to be an arterial steal phenomenon or persistent venous congestion, with calcification occurring in a chronic hypoperfused state or with dystrophic changes in the walls of congested veins.

Protective effect of ebselen on aflatoxin B1-induced cytotoxicity in primary rat hepatocytes

Recent studies have shown that aflatoxin B1 enhances reactive oxygen species formation and causes oxidative damage, which may ultimately contribute to the cytotoxicity and carcinogenic effect of aflatoxin B1. Ebselen, 2-phenyl-1,2-benzoisoseleazol-3(H)-one, a synthetic seleno-organic compound has been shown to possess glutathione peroxidase-like activity and free radical scavenging ability. Thus present study was designed to investigate the protective effect of ebselen on aflatoxin B1-induced cytotoxicity in primary rat hepatocytes. Aflatoxin B1-induced cytotoxicity and lipid peroxidation were determined by lactate dehydrogenase leakage and malondialdehyde generation, respectively. Intracellular reactive oxygen species level was measured using the fluorescent probe 2',7'-dichlorofluorescin diacetate, and the intracellular reduced glutathione concentration was determined with a fluorometric method. Ebselen was found to display a dose-dependent protective effect on lactate dehydrogenase leakage and malondialdehyde generation caused by aflatoxin B1 exposure. The results also demonstrate that ebselen efficiently inhibits the intracellular reactive oxygen species formation in aflatoxin B1-treated hepatocytes in a dose and time-dependent manner. It was also noted that ebselen was able to increase the intracellular reduced glutathione concentration, both in the control and in aflatoxin B1-treated hepatocytes. The protection of ebselen against aflatoxin B1 cytotoxicity, however, was not affected by lowering the concentration of intracellular reduced glutathione. The overall data indicate that ebselen possesses a potent protective effect against aflatoxin B1-induced cytotoxicity, and the main mechanism involved in the protection may be its strong capability in inhibiting intracellular reactive oxygen species formation and preventing oxidative damage.

Resolution of the pathways of poliovirus type 1 transmission during an outbreak

An outbreak of poliomyelitis with 20 cases occurred in Israel, Gaza, and the West Bank from October 1987 to October 1988. The wild type 1 poliovirus associated with the outbreak was most closely related to viruses found in the Nile Delta. The epidemiologic links among patients involved in the outbreak and patients with community-acquired infections during the outbreak were inferred from the evolutionary relationships among isolates of the outbreak virus. Complete VP1 sequences (906 nucleotides) were determined for 12 clinical and 4 sewage isolates. A total of 58 nucleotide differences were found among the 16 isolates; 74% of all substitutions were synonymous third-position transitions. An evolutionary tree, representing both the pathways of VP1 sequence evolution and the inferred chains of virus transmission during the outbreak, was constructed under the assumption that each substitution had occurred only once. The combined epidemiologic and molecular data suggest that a single founder strain was introduced into Israel from the vicinity of Gaza in the fall of 1987. Poliovirus circulation was apparently localized to southern communities during the winter and spread north by the following summer into the Hadera subdistrict of Israel, where it radiated via multiple chains of transmission into other communities in northern Israel and the West Bank. The close sequence matches (>99%) between clinical and sewage isolates from the same communities confirm the utility of environmental sampling as a tool for monitoring wild poliovirus circulation.

Small hepatocellular carcinoma: safety and efficacy of single high-dose percutaneous acetic acid injection for treatment

PURPOSE

To evaluate the safety and efficacy of single high-dose percutaneous acetic acid injection (PAI) for treatment of small (<3-cm-diameter) hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Eighteen patients with HCC (22 nodules; diameter range, 1.5-3.0 cm) underwent single PAI. With ultrasonographic or computed tomographic (CT) guidance, 4-11 mL of 50% acetic acid was slowly injected into the center of the nodule through a skinny multiple-side-hole needle. Follow-up was performed with helical contrast material-enhanced CT. Complications of high-dose PAI were recorded.

RESULTS

Seventeen nodules showed no local recurrence (follow-up, 6-29 months) after single PAI. At a mean follow-up of 15.6 months, mean tumor diameter was 2.1 cm and mean injected volume was 6.4 mL. Four nodules showed residual tumor (mean tumor diameter, 2.6 cm; mean injected volume, 5.8 mL). The mean ratio of injected to estimated volume of acetic acid was 1.21 in cases of successful single PAI and 0.72 in cases of local recurrence (P < .001). One patient with preexistent right portal venous thrombosis died of hepatic failure 37 days after PAI. Other complications included severe pain (11%), high fever (4%), and segmental wedge infarction (4%).

CONCLUSION

Single high-dose PAI is safe and effective for treatment of small HCC.

Ebselen induces apoptosis in HepG(2) cells through rapid depletion of intracellular thiols

Ebselen, 2-phenyl-1,2-benzisoselenazol-3(2H)-one, is a synthetic seleno-organic compound with antioxidant capability. In the present study, we systematically examined the ability of ebselen to induce apoptosis in a human hepatoma cell line, HepG(2). Ebselen-induced apoptosis was evaluated by (i) TdT-mediated dUTP nick end labeling assay; (ii) analysis of sub-G1 cells; (iii) cell morphology, including cell size and granularity examination; and (iv) DNA gel electrophoresis. The results showed that ebselen was able to induce typical apoptosis in HepG(2) cells in a dose- and time-dependent manner. In order to explore the possible mechanisms involved in ebselen-induced apoptosis, the effect of ebselen on intracellular thiol concentrations including reduced glutathione (GSH) and protein thiols and the effect of N-acetylcysteine (NAC) and buthionine sulfoximine (BSO) pretreatment on ebselen-induced apoptosis were investigated. It was found that (i) ebselen rapidly depleted intracellular GSH and protein thiols, moreover, the depletion preceded the occurrence of apoptosis; (ii) NAC, a precursor of intracellular GSH synthesis, significantly alleviated ebselen-induced apoptosis; and (iii) BSO, a specific inhibitor of intracellular GSH synthesis, augmented ebselen-induced apoptosis significantly. Taken together, the present study demonstrates that ebselen is able to induce apoptosis in HepG(2) cells, most probably through rapid depletion of intracellular thiols.

Experimental corneal neovascularization by basic fibroblast growth factor incorporated into gelatin hydrogel

The study was designed to investigate the feasibility of using an acidic gelatin hydrogel as a biodegradable vehicle for basic fibroblast growth factor (bFGF). bFGF was incorporated by polyion complexation into a biodegradable hydrogel prepared by cross-linking acidic gelatin with the isoelectric point of 4.9. The dried hydrogel (sized to 2x1 mm) was hydrated with bFGF aqueous solution including different doses of bFGF (20, 50, 125, 250 and 500 ng) and implanted into a rabbit corneal pocket (2.5x2 mm). As a control group, the gelatin hydrogel without bFGF or bFGF alone (500 ng) was used. Corneal angiogenesis was evaluated by biomicroscopy, corneal fluorescein angiography and histology for 21 days. Photographs were taken and corneal angiogenesis was evaluated by image analysis. The hydrogel degraded with time after its implantation into the corneal pocket. Experimental eyes receiving the hydrogel containing more than 50 ng of bFGF demonstrated significant corneal angiogenesis. Control eyes and eyes receiving the hydrogel containing 20 ng of bFGF showed no corneal angiogenesis. Corneal angiogenesis, which occurred on the 3rd or 4th day after implantation, reached maximal growth on about day 7 and regressed from day 10 after implantation. The area of angiogenesis showed a dose-dependency on bFGF. The gelatin hydrogel itself induced neither angiogenesis nor inflammation. These results suggested that acidic gelatin hydrogel releases bioactive bFGF with its biodegradation, resulting in corneal neovascularization.

Modulation transfer function and critical flicker frequency in high-myopia patients

BACKGROUND AND PURPOSE

Critical flicker frequency (CFF) decreases due to optic nerve and retinal damage in patients with optic neuritis or glaucoma. Because retinal degeneration is also found in high myopia, we investigated whether the modulation transfer function (MTF) and CFF are altered in patients with high myopia.

METHODS

Forty-six patients with high myopia (< -8 diopters, D) were recruited from our outpatient department. The control group comprised 21 young volunteers with myopia of 0 to -2 D. The myopic and control groups were similar in terms of age and sex.

RESULTS

At all frequencies tested, the myopic group had lower CFF and higher modulation values than the control group. The mean CFF was significantly lower in myopic patients (46.8 +/- 9.0 Hz) than in control subjects (52.5 +/- 4.4 Hz). Patients with extremely high myopia (< -10 D) had significantly greater modulation values at 5, 10, 15, 55 and 60 Hz than those with moderately high myopia (-8 D to -10 D). The CFF did not differ significantly between those with extremely high (46.3 +/- 8.8 Hz) and those with moderately high (49.0 +/- 6.9 Hz) myopia.

CONCLUSIONS

The findings of this study support that the CFF decreases and MTF increases in patients with high myopia, and that the alternation of MTF is related to the degree of myopia. CFF and MTF may, therefore, have potential as indexes to evaluate the severity of retinal degeneration in patients with high myopia.

Insertion/deletion mutations of type I oculocutaneous albinism in chinese patients from Taiwan

Type I oculocutaneous albinism (OCA1) is an autosomal recessive disorder, which is caused by the reduction or the absence of tyrosinase activity in melanocytes of the skin, hair and eyes. Although tyrosinase mutations of OCA1 have been extensively analyzed in most populations worldwide, there is no systemic study of OCA1 mutation in Chinese patients. By use of single strand conformation polymorphism and direct sequencing, we had detected 21 mutant alleles out of 24 OCA1 chromosomes screened (87.5%). Detected mutant alleles include one splicing site, three insertion/deletion and five missense mutations, of which the splicing site nucleotide alteration (IVS 1-3C>G) and two each of the insertion/deletion (232-233 ins GGG and 861-862 del TT) and missense mutations (Cys 289 Gly and Trp 400 Leu) are novel. The ins/del mutations accounts for about 37.5% in Chinese OCA1 alleles. The 232-233 ins GGG, one of the novel mutations, was found to be most frequent (25%) among the OCA1 alleles in Chinese. Through this study, we found that while some of the OCA mutant alleles were identified in other populations, ethnic difference still exists. Hum Mutat 14:542, 1999.

Effect of Salvia miltiorrhiza on aflatoxin B1-induced oxidative stress in cultured rat hepatocytes

Recent findings have suggested that oxidative damage might contribute to the cytotoxicity and carcinogenicity of aflatoxin B1 (AFB1). Salvia miltiorrhiza (Sm), a herbal plant that has been used extensively in traditional Chinese medicine for treating cardiovascular and liver diseases, is believed to have some antioxidative capabilities. In this study, the protective effect of Sm against AFB1-induced cytotoxicity was investigated in cultured primary rat hepatocytes. AFB1-induced cytotoxicity and lipid peroxidation (LPO) were estimated by determination of lactate dehydrogenase (LDH) leakage and thiobarbituric acid reactive substances (TBARS) formation, respectively. Intracellular reactive oxygen species (ROS) formation was measured using a fluorescent probe 2',7'-dichlorofluorescein diacetate (DCFH-DA). In addition, changes of intracellular glutathione (GSH) content were also studied. Results showed that Sm was able to suppress the LDH leakage induced by AFB1 in a dose-dependent manner. A dose-dependent inhibitory effect of Sm on AFB1-induced LPO was also found in hepatocytes treated with Sm. It was further observed that Sm produced an inhibitory effect on ROS formation caused by AFB1. Concomitantly, the GSH content in Sm-treated groups increased substantially compared to those without Sm treatment. These findings suggest that Sm can inhibit the cytotoxicity of AFB1 through decreasing ROS formation, inhibiting LPO and preventing GSH depletion. The major component of the aqueous extract of Sm was identified by using high performance liquid chromatography (HPLC), proton magnetic resonance (1H-NMR) and mass spectrum (MS). Analytical results suggested that D(+)beta3,4-dihydroxyphenol lactic acid (DA) is the main compound of the aqueous extract of Sm.

Design of synthetic hexapeptide substrates for prostate-specific antigen using single-position minilibraries

Prostate-specific antigen (PSA), a serine endoprotease with chymotrypsin-like substrate specificity, is a marker used widely for detection of prostate cancer and other prostate diseases, catalyzing hydrolysis of the gel-forming proteins semenogelins I and II, which are synthesized and secreted by the seminal vesicle. In this study we report the use of two single-position minilibraries and RP-HPLC selection to optimize a hexapeptide substrate for PSA, spanning substrate positions P3 to P3'. PSA has been shown previously to prefer tyrosine in position P1 [Denmeade et al. (1997) Cancer Research, 57, 4924-4930]. Here we demonstrate preference for serine in position P1' and strong preference for phenylalanine in position P2. Based on these results we have designed and demonstrated the utility of the optimized fluorogenic PSA substrate 7-methoxy-coumarin-4-acetylGlnPheTyrSerSerAsnLys(epsilon-2,4-dinit rophenyl)amide, 1, which permits continuous monitoring of PSA endopeptidase activity at high sensitivity.

Small functional adrenal cortical adenoma: treatment with CT-guided percutaneous acetic acid injection--report of three cases

Two patients with Conn syndrome and one patient with Cushing syndrome underwent computed tomography (CT)-guided tumor ablation with a total of 5-11 mL of 50% acetic acid injected into their adrenal nodule (1.3-3.3 cm in diameter). No major complications were encountered during or after the procedure. All patients were symptom free with normal laboratory test results for at least 1-year follow-up. CT images showed complete cystic change with tumor size regression. Our preliminary results suggest that percutaneous acetic acid injection is a safe and effective alternative for treatment of small functional adrenal cortical adenoma.

Detection and assessment of circle of Willis aneurysms in acute subarachnoid hemorrhage with three-dimensional computed tomographic angiography: correlation with digital substraction angiography findings

In this retrospective study, we examined the usefulness of computed tomographic angiography (CTA) for the detection and assessment of circle of Willis aneurysms in patients with acute nontraumatic subarachnoid hemorrhage (SAH), using selective digital substraction angiography (DSA) as the gold standard. Thirty-five patients who presented with acute, nontraumatic SAH, diagnosed on the basis of unenhanced computed tomography or lumbar puncture findings or both, underwent both CTA and DSA. The CTA images were interpreted for the presence, location, size, and shape of the aneurysm, presence of a neck, and relationship of the aneurysm to adjacent arterial branches. The CTA and DSA images were then compared, with the latter images serving as the gold standard. DSA revealed 37 aneurysms in 32 patients and ruled out intracranial aneurysms in the remaining three. The sensitivity and specificity of CTA for aneurysm detection were 97% and 100%, respectively. The size of the smallest aneurysm shown was 4 mm, and the largest aneurysm was 21 mm. The size and lobularity of the aneurysms estimated from CTA images corresponded well with those estimated from DSA images. In addition, CTA provided a three-dimensional representation of the aneurysmal lesion, which was considered useful for surgical planning. Our results confirm the accuracy of CTA in comparison with DSA. Because of its reliability, minimal invasiveness, and rapidity, CTA may become the technique of choice for neuroradiologic work-up of SAH patients. DSA then would be used to diagnose intracranial aneurysms only in selected, questionable cases.

Recurrent inverted papilloma: diagnosis with pharmacokinetic dynamic gadolinium-enhanced MR imaging

BACKGROUND AND PURPOSE

Dynamic gadolinium-enhanced MR imaging has been used successfully to identify post-treatment recurrence or postoperative changes in rectal and cervical carcinoma. Our purpose was to evaluate the usefulness of dynamic gadolinium-enhanced MR imaging for distinguishing recurrent inverted papilloma (IP) from postoperative changes.

METHODS

Fifteen patients with 20 pathologically proved lesions (recurrent IP, 12; fibrosis or granulation tissue, eight) were enrolled in the study. Three observers, blinded to pathologic results, independently evaluated conventional MR images, including T1-weighted (unenhanced and postcontrast), proton-density-weighted, and T2-weighted spin-echo images. Results then were determined by consensus. Dynamic images were obtained using fast spin-echo sequences at 5, 30, 60, 90, 120, 150, 180, and 300 seconds after the injection of gadolinium-diethylene-triamine penta-acetic acid. Time-signal intensity curves of suspected lesions were analyzed by a pharmacokinetic model. The calculated amplitude and tissue distribution time were used to characterize tissue, and their values were displayed as a color-coded overlay.

RESULTS

T2-weighted images yielded a sensitivity of 67%, a specificity of 75%, and an accuracy of 70% in the diagnosis of recurrent IP. Contrast-enhanced T1-weighted images yielded a sensitivity of 75%, a specificity of 50%, and an accuracy of 65%. Pharmacokinetic analysis showed that recurrent IP had faster (distribution time, 41 versus 88 seconds) and higher (amplitude, 2.4 versus 1.2 arbitrary units) enhancement than did fibrosis or granulation tissue. A cut-off of 65 seconds for distribution time and 1.6 units for amplitude yielded a sensitivity of 100% and a specificity of 100% for diagnosing recurrent IP.

CONCLUSION

Dynamic MR imaging can differentiate accurately recurrent IP from postoperative changes and seems to be a valuable diagnostic tool.

Imaging diagnosis of insufficiency fracture of the sacrum

BACKGROUND

Insufficiency fracture of the sacrum has been recognized as a major cause of lower back pain, especially in elderly osteoporotic patients with or without underlying malignancy and/or prior pelvic radiotherapy. Its diagnosis cannot be readily made from its nonspecific clinical features. Consequently some cases may be mistaken for bone metastases, causing patients to receive inappropriate diagnostic measures and management. Recognition of the spectrum of imaging features is the basis of correct diagnosis and treatment.

METHODS

The imaging studies of 14 cases (12 women and 2 men; age range, 60-84 years; mean age, 70 years) of sacral insufficiency fracture were reviewed retrospectively. These included 14 radiographs, six bone scintigraphs, eight computerized tomography (CT) scans and 12 magnetic resonance (MR) imaging studies. Six patients had a history of malignancy. Diagnosis was made by characteristic imaging findings, and clinical and radiographic follow-up for one to 3.5 years.

RESULTS

Five cases of sacral insufficiency fracture were suspected based on radiographic findings of fracture lines (2 cases) and focal sclerosis (3 cases). Seven cases were diagnosed by CT findings of linear fractures (7 cases) and focal sclerosis (2 cases). Nine MR examinations demonstrated characteristic vertical bands of marrow edema. A hypointense fracture line was identified in eight cases. The remaining two MR imaging studies disclosed nonspecific focal marrow edema. An early case, which appeared normal on CT scan, showed marrow edema on MR imaging. The positive and diagnostic rates were both 36% for plain radiographs, 88% for CT scans, and 100% and 83%, respectively, for MR images.

CONCLUSIONS

Plain radiographs are often unrewarding. Although MR imaging is the most sensitive tool, fracture lines are best demonstrated and diagnosed using CT. Due to the better diagnostic rate, popularity and cost effectiveness, CT is recommended as the definitive modality for confirming diagnosis of insufficiency fracture of the sacrum.

Rapid diagnosis of common aneuploidies by quantitative fluorescent polymerase chain reaction

The most frequent autosomal aneuploidies in newborns involve chromosomes 21, 18, and 13. The pre- and postnatal detection of chromosome abnormalities has been almost exclusively performed by cytogenetic analysis. In this paper, we assess the diagnostic value of fluorescent polymerase chain reaction (PCR) using polymorphic small tandem repeats (STR). PCR products are distinguished via both size and fluorescence intensity to confirm the trisomy by either triallelic signals with similar fluorescence intensities or diallelic pattern with double-dose response. Compared with the relatively time-consuming and laborious classic cytogenetic analysis, this technique is rapid, inexpensive, and sensitive for the detection of trisomies 21, 18 and 13, particularly when the numbers of cells obtained from the prenatal diagnosis is limited or where cell culture fails. With greater samples tested and more STR markers available, this method will become more reliable. This study investigates the detection of aneuploides involving chromosomes 21, 18, and 13 by comparing quantitative fluorescent PCR with karyotyping performed by conventional cytogenetics. The results obtained by the two techniques were concordant in all trisomy cases of this study.

Central nervous pathway for acupuncture stimulation: localization of processing with functional MR imaging of the brain--preliminary experience

PURPOSE

To characterize the central nervous system (CNS) pathway for acupuncture stimulation in the human brain by using functional magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Functional MR imaging of the whole brain was performed in two groups of nine healthy subjects during four stimulation paradigms: real acupuncture at acupoints ST.36 (on the leg) and LI.4 (on the hand) and control stimulations (minimal acupuncture and superficial pricking on the leg). Stimulations were performed in semirandomized, balanced order nested within two experiments. Psychophysical responses (pain, De-Qi effect [characteristic acupuncture effect of needle-manipulation sensation], anxiety, and unpleasantness) and autonomic responses were assessed. Talairach coordinates-transformed imaging data were averaged for a group analysis.

RESULTS

Acupuncture at LI.4 and ST.36 resulted in significantly higher scores for De-Qi and in substantial bradycardia. Acupuncture at both acupoints resulted in activation of the hypothalamus and nucleus accumbens and deactivation of the rostral part of the anterior cingulate cortex, amygdala formation, and hippocampal complex; control stimulations did not result in such activations and deactivations.

CONCLUSION

Functional MR imaging can demonstrate the CNS pathway for acupuncture stimulation. Acupuncture at ST.36 and LI.4 activates structures of descending antinociceptive pathway and deactivates multiple limbic areas subserving pain association. These findings may shed light on the CNS mechanism of acupuncture analgesia and form a basis for future investigations of endogenous pain modulation circuits in the human brain.

Suppression of experimental corneal angiogenesis by focal X-ray irradiation

PURPOSE

To investigate the effect of focal X-ray irradiation on experimental corneal angiogenesis in the rabbit.

METHODS

A gelatin hydrogel sheet impregnated with basic fibroblast growth factor was implanted into the corneal stroma of rabbits; this induced corneal angiogenesis. After the first sign of corneal angiogenesis was noted, the corneal region was irradiated with a dose of 10 Gy or 20 Gy. The control rabbits received no irradiation. The eyes were examined by slitlamp biomicroscopy and photographed, over a period of 28 days. The maximum length and total surface area of corneal angiogenesis were quantified by computerized image analysis.

RESULTS

Corneal angiogenesis was noted on day 3 following implantation of the hydrogel sheet. In the rabbits irradiated with 10 Gy, the maximum length and total surface area of corneal angiogenesis were both significantly lower on day 4 and 7 following irradiation, compared to the respective measurement in the controls. In the rabbits irradiated with 20 Gy, the maximum length and total surface area of corneal angiogenesis were significantly lower between days 4 and 21, and between days 4 and 14, respectively, compared to the respective measurement in the controls.

CONCLUSIONS

Focal X-ray irradiation to the corneal region suppressed corneal angiogenesis in a dose-dependent manner. Focal X-ray irradiation may be beneficial in treating ocular angiogenesis.

Sodium selenite-induced oxidative stress and apoptosis in human hepatoma HepG2 cells

The mechanisms involved in the anti-carcinogenic activity of selenium remain to be elucidated. In the present study, we examined sodium selenite-induced oxidative stress and apoptosis in a human hepatoma cell line (HepG2). Sodium selenite (10 microM) exerted clear cytotoxic effect, as shown by the significant increase of lactate dehydrogenase leakage. Selenite-induced DNA alterations in apoptosis were studied by: 1. comet assay; 2. TdT-mediated dUTP nick end-labeling assay. In addition, characteristic apoptotic morphological alterations were also observed in selenite-treated cells. Our results clearly show that Se-induced cell death occurs predominantly in the form of apoptosis. Selenite-induced oxidative stress was evaluated by the measurement of reactive oxygen species production using lucigenin-dependent chemiluminescence. The involvement of glutathione in selenite-induced oxidative stress was further demonstrated by the concurrent decline of intracellular reduced glutathione and increase of oxidized glutathione contents in Se-treated cells. Moreover, the finding that selenite-induced oxidative stress and apoptosis was significantly attenuated by superoxide dismutase, catalase and deferoxamine provides additional evidence to suggest that Se-induced oxidative stress mediates the induction of apoptosis, a mechanism related to the anti-carcinogenic and chemopreventive effect of Se.

Mutation analysis of Wilson disease in Taiwan and description of six new mutations

Wilson disease is an autosomal recessive disorder of copper metabolism. Mutation screening in Wilson disease has led to the detection of at least 89 disease-specific mutations. Some mutations appear to be population specific, while others are common to many populations. In this study, 38 Taiwanese patients with Wilson disease were screened using single-strand conformation polymorphism analysis, followed by direct DNA sequencing. We found 12 different mutations, six of which were novel. All our detected mutations were found to be in eight exons. Four mutations in three loci (Arg778Gln, Arg778Leu, Gly943Asp, and Pro992Leu) accounted for about 58% of the mutant alleles we detected. Using an RNA transcriptional assay, we confirmed that both of our detected splice-site mutations resulted in exon skipping.

Sodium selenite-induced oxidative stress and apoptosis in human hepatoma HepG2 cells

The mechanisms involved in the anti-carcinogenic activity of selenium remain to be elucidated. In the present study, we examined sodium selenite-induced oxidative stress and apoptosis in a human hepatoma cell line (HepG2). Sodium selenite (10 microM) exerted clear cytotoxic effect, as shown by the significant increase of lactate dehydrogenase leakage. Selenite-induced DNA alterations in apoptosis were studied by: 1. comet assay; 2. TdT-mediated dUTP nick end-labeling assay. In addition, characteristic apoptotic morphological alterations were also observed in selenite-treated cells. Our results clearly show that Se-induced cell death occurs predominantly in the form of apoptosis. Selenite-induced oxidative stress was evaluated by the measurement of reactive oxygen species production using lucigenin-dependent chemiluminescence. The involvement of glutathione in selenite-induced oxidative stress was further demonstrated by the concurrent decline of intracellular reduced glutathione and increase of oxidized glutathione contents in Se-treated cells. Moreover, the finding that selenite-induced oxidative stress and apoptosis was significantly attenuated by superoxide dismutase, catalase and deferoxamine provides additional evidence to suggest that Se-induced oxidative stress mediates the induction of apoptosis, a mechanism related to the anti-carcinogenic and chemopreventive effect of Se.

Intra-articular gouty tophi of the knee: CT and MR imaging in 12 patients

OBJECTIVE

To define the imaging characteristics of intra-articular tophi of the knee.

DESIGN AND PATIENTS

Twelve patients with intra-articular tophi in the knee were studied with routine MR imaging, gadolinium (Gd)-enhanced MR imaging, and CT over a 4-year period. There were 11 men and one woman, 25-82 years of age (mean age 48 years). Four patients did not have a documented history of gout at the time of the MR examination. The diagnosis of intra-articular tophi was provided by arthroscopy and histological examination (5 patients), by microscopic study of joint fluid (5 patients), or by characteristic clinical, laboratory and imaging findings (2 patients).

RESULTS

In 15 MR examinations the tophi were located purely intra-articularly in 10 knees. In the remaining five MR studies, periarticular soft tissues or bone, or both, were involved. All the intra-articular tophi manifested low to intermediate signal intensity on both T1- and T2-weighted images. All five Gd-enhanced MR examinations demonstrated a heterogeneous peripheral enhancement. All 10 CT scans showed varying degrees of stippled calcifications within the tophi. The nature of the calcifications was confirmed on histological examination in three patients.

CONCLUSION

Presenting clinical manifestations of gout may relate to intra-articular tophaceous deposits. Such deposits present as masses on MR images with low to intermediate signal intensity on both T1- and T2-weighted images and a characteristic enhancement pattern following intravenous Gd administration. These features relate primarily to internal calcifications, which are most evident on CT images. MR evaluation (including Gd administration) supplemented, in some cases, with CT scanning allows accurate diagnosis of intra-articular tophaceous deposits.