A novel anti-HBeAg homolignan, taiwanschirin D from Kadsura matsudai

A novel C19 homolignan, taiwanschirin D (1), possessing a 3,4-(1-[(Z)-2-methoxy-2-oxoethylidenel)pentano (2,3-dihydrobenzo[b]furan)-3(2-oxoacetate) skeleton, was isolated from the stem of Kadsura matsudai Hayata. Its structure was determined from physical and spectral data including 2D NMR spectra. The Anti-HBeAg test revealed that taiwanschirin D (1) had moderate activity at a concentration of 94.3 microM (50 microg/ml).

Exposure to and actions against passive smoking in non-smoking pregnant women in Guangzhou, China

BACKGROUND

The objective was to describe the extent of passive smoking exposure and preventive actions against passive smoking in non-smoking pregnant women and to analyze factors associated with preventive actions.

METHODS

This was a cross-sectional survey on 1449 never-smoking pregnant women who made their first prenatal visit to the Women and Children's Hospital of Guangzhou, China during 1996-97.

RESULTS

60.2% (95% Confidence Interval 57.7%-62.7%) of the never-smoking pregnant women had a husband who currently smoked. Women with smoking husbands (n=872) were more exposed to ETS than those with non-smoking husbands (n=577) at home (71% vs. 33%), in public places (77% vs. 66%) and at work (60% vs. 50% of working women), and they took less actions against passive smoking in public places. Women with better education and knowledge on smoking and passive smoking had stronger preventive actions.

CONCLUSIONS

Non-smoking pregnant women in China are often exposed to passive smoking and their preventive actions are weak. Passive smoking is an important obstetric and public health problem in developing countries and deserves urgent international attention.

Direct visualization of the genomic distribution and organization of two cervid centromeric satellite DNA families

Several repetitive DNA fragments were generated from PCR amplifications of caribou DNA using primer sequences derived from the white-tailed deer satellite II DNA clone OvDII. Two fragments, designated Rt-0.5 and Rt-0.7, were sequenced and found to have 96% sequence similarity. These caribou clones also had 85% sequence similarity with OvDII. Multiple-colored fluorescence in situ hybridization (FISH) studies with satellite I and satellite II DNA probes to caribou metaphase chromosomes and extended chromatin fibers provided direct visualization of the genomic organization of these two satellite DNA families, with the following findings: (1) Cervid satellite I DNA is confined to the centromeric regions of the acrocentric autosomes, whereas satellite II DNA is found at the centromeric regions of all chromosomes except for the Y. (2) For most acrocentric chromosomes, the satellite I signal appeared to be medially located at the primary constriction, in contrast to that of satellite II, which appeared to be oriented toward the lateral sides as two separate fluorescent dots. (3) The satellite II clone Rt-0.7 appeared to be enriched in the centromeric region of the caribou X chromosome, a pair of biarmed autosomes, and a number of other acrocentric autosomes. (4) Fiber-FISH demonstrated that the satellite I and satellite II arrays were juxtaposed. On highly extended chromatin fibers, the total length of the hybridization signals for the two satellite DNA arrays often reached 300-400 microm. The length of a given satellite II array usually reached 200 microm, corresponding to 2 x 10(3) kb of DNA in a given centromere.

Protein N-arginine methylation in subcellular fractions of lymphoblastoid cells

Arginine methylation in RNA-binding proteins containing arginine- and glycine-rich RGG motifs is catalyzed by specific protein arginine N-methyltransferase in cells. We previously showed that lymphoblastoid cells grown in the presence of an indirect methyltransferase inhibitor, adenosine dialdehyde (AdOx), accumulated high level of hypomethylated protein substrates for the endogenous protein methyltransferases or recombinant yeast arginine methyltransferase [Li, C. et al. (1998) Arch. Biochem. Biophys. 351, 53-59]. In this study we fractionated the lymphoblastoid cells to locate the methyltransferases and the substrates in cells. Different sets of hypomethylated methyl-accepting polypeptides with wide range of molecular masses were present in cytosolic, ribosomal, and nucleus fractions. The methylated amino acid residues of the methyl-accepting proteins in these fractions were determined. In all three fractions, dimethylarginine was the most abundant methylated amino acid. The protein-arginine methyltransferase activities in the three fractions were analyzed using recombinant fibrillarin (a nucleolar RGG protein) as the methyl-accepting substrate. Fibrillarin methylation was strongest in the presence of the cytosolic fraction, followed by the ribosomal and then the nucleus fractions. The results demonstrated that protein-arginine methyltransferases as well as their methyl-accepting substrates were widely distributed in different subcellular fractions of lymphoblastoid cells.

Identification of the spinocerebellar ataxia type 7 mutation in Taiwan: application of PCR-based Southern blot

Spinocerebellar ataxia (SCA) type 7 is an autosomal dominant disorder characterized by neural loss, mainly in the cerebellum and regions of the brainstem and particularly the inferior olivary complex. This neurodegeneration disease is associated with expansion of unstable CAG repeats within the 5'-translated region of the SCA7 gene, located on chromosome 3p. We conducted a local survey of the normal population and candidate patients for the analysis of the CAG repeats in the SCA7 gene. The distributions of the CAG repeat units of SCA7 gene in the normal population in Taiwan were established in this study by using the radioactive genomic polymerase chain reaction (PCR). The normal range of CAG repeats is from 6 to 17 repeats, with the more common being around 8-13 repeats. The range is narrower than that reported for other ethnic groups (7-35 CAGs). Meanwhile, by the use of a combination of PCR and Southern blot analysis, one SCA7 family was identified and is reported here. A marked instability of the CAG repeat number during transmission from father to son (41 vs. 100) was observed in the SCA7 family. Clinical anticipation is significant in this family including an infantile case, who was found to have nystagmus from the age of 1 month. To date, the SCA7 mutation has been detected in one of 73 families with autosomal dominant cerebellar ataxia phenotypes, which is about 1.4% of the ataxia families referred to us, compared to 1.4% SCA1, 9.6% SCA2, and 27.3% SCA3/Machado-Joseph disease in our collection. In addition, we demonstrate that the PCR-based Southern blot analysis, with the advantages of sensitivity of PCR and specificity of Southern blot, is a reliable diagnostic method for SCA7 mutation screening. The molecular analysis technique makes possible the quick and accurate diagnosis of SCA7 patients and in the future will hopefully be applied to prenatal screening for SCA7 families.

Novel point mutation within intron 10 of FMR-1 gene causing fragile X syndrome

The majority of cases involving fragile X syndrome are due to expansion of a (CGG)n trinucleotide repeat at the 5' untranslated region of the FMR-1 gene. Deletion and intragenic loss of function mutations of the FMR-1 gene also have been reported. Here, we report a C to T point mutation at the 14th nucleotide in intron 10 of the FMR-1 gene in three unrelated fragile X patients. However, the (CGG)n repeat of FMR-1 in those patients does not expand. To determine the effect of this mutation on the patients' FMR-1 transcripts, total RNA from peripheral blood cells was reverse transcribed and amplified by polymerase chain reaction (RT-PCR). Direct and subcloned sequencing of the RT-PCR products revealed that the transcripts from the allele with C to T mutation skip exon 10 entirely, resulting in a joining of exons 9 and 11. Deletion of exon 10 results in frame-shift and premature termination of translation, which removes the highly conserved region that encoding the KH2 and RGG box domains of FMRP. Interestingly, a male of the three patients has another G to A substitution in exon 15. However, the intron 10 mutation is sufficient for development of fragile X syndrome.

Molecular diagnosis of fragile X syndrome and distribution of CGG repeats in the FMR-1 gene in Taiwanese

BACKGROUND AND PURPOSE

Fragile X syndrome, the most frequent form of inherited mental retardation, is caused by abnormal expansion of the CGG trinucleotide repeats in the 5' untranslated region of the FMR-1 gene. In this study, we describe the prenatal diagnosis of fragile X syndrome and the distribution of CGG repeat numbers in the FMR-1 gene, which has not been previously reported in Taiwanese.

METHODS

Using polymerase chain reaction (PCR), we determined the range of the CGG repeats in the FMR-1 gene in 316 normal individuals (350 X chromosomes) and 349 mentally retarded patients (429 X chromosomes). For prenatal diagnosis of fragile X syndrome, DNA extracted from amniotic fluid cells was used for PCR determination of CGG repeats.

RESULTS

Because there were no significant differences between the distribution of the (CGG)n alleles between the mentally retarded and normal subjects, the data were pooled. Among the 779 X chromosomes studied, 24 different alleles were identified with a low of 16 and a high of 45 CGG repeats. The 29 repeat allele was the most common, followed by the 30 and the 28 repeat alleles. We effectively amplified slightly expanded premutation alleles of up to about 90 CGG repeats. In the prenatally diagnosed fetus, a normal 29 repeat allele was found.

CONCLUSIONS

Determination of the distribution of the CGG repeats in the FMR-1 gene in Taiwanese is useful in genetic counseling regarding fragile X syndrome. Prenatal molecular diagnosis of the syndrome can be successfully performed using amniotic fluid cells.

Distribution of CAG repeat size in the dentatorubral and pallidoluysian atrophy (DRPLA) gene in a normal population in Taiwan

Dentatorubral and pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder with expansion of trinucleotide CAG repeats in the coding region of the gene. Expansion of the repeat tract beyond the normal range produces gene products with extended polyglutamine tracts. In this study, we analyzed the distribution of the CAG repeats in the DRPLA alleles in a normal Taiwanese population. We observed 15 different alleles and found that the range of the CAG repeat number was from 7-21. The most frequent allele contained 15 CAG repeats that represented 20% of the total analyzed alleles, followed by the 17 repeats (15.8%). The heterozygosity rate of this locus was 88%. Twelve parents-to-children transmissions of the DRPLA alleles in a Machado-Joseph disease family appeared to be normal without any alteration of the CAG repeat numbers. Phenotypes of DRPLA overlapped those of autosomal dominant cerebellar ataxia (ADCA). In order to identify DRPLA patients in Taiwan, we screened six autosomal dominant cerebellar ataxia patients without expansion in known spinocerebellar ataxia genes. All six patients had the repeat numbers within the normal range; thus, the possibility of DRPLA could be excluded.

Automated high throughput human CYP isoform activity assay using SPE-LC/MS method: application in CYP inhibition evaluation

1. A high throughput screening (HTS) method for the evaluation of the seven major human hepatic CYP isoform activities was developed on a 96-well format, with automation. The method utilized pooled human liver microsomes and seven probe substrates, generic conditions for incubation, reaction termination and metabolite extraction with solid phase extraction (SPE) plates. Metabolites from the seven reactions were pooled and quantified using a generic liquid chromatography and tandem mass spectrometry (LCMS/MS) method. 2. The HTS method was validated based on Km values obtained, which were in agreement with literature data. 3. The isoform inhibition profiles of ketoconazole, quinidine, sulfaphenazole, tranylcypromine, alpha-naphthoflavone, and 4-methylpyrazole against CYPs 3A4, 2D6, 2C9, 2A6 land 2C19), 1A2 and 2E1, respectively, were obtained by this HTS method. Graphically obtained IC50 values are in agreement with literature reported values. 4. The HTS method represents a significant efficiency and selectivity improvement over traditional methods, and can be used for CYP inhibition assay and can be extended for liver activity profiling.

Plan-view imaging of oxygen-induced reconstruction on Ag(110) surface. II. Effect of high-energy electron thinning

The feasibility and the limitation of the 'high-energy electron thinning' method for the production of surface-science-grade samples in situ in the electron microscope are studied. Exploiting the electron beam supplied by high-voltage electron gun in electron microscope, this method can be readily realized. An obvious advantage of this method is that we can monitor the sample surface concurrently. However, this sample preparation method depends strongly on the sample material and the local environment within the electron microscope. Factors relating to the electron thinning speed are briefly discussed.

[The influence on oxgen-carrying capacity of procine hemoglobin while attached PEG to increase its total molecular weight]

Increasing the total molecular weight of hemoglobin through PEG modification has been proved to be a better choice in prolonging vascular retention time. As a long, linear, hydrophilic molecular, PEG exerts significant influence on the oxygen-carrying properties of porcine hemoglobin (pHb) when attached. PEG-hemoglobins exhibit a wide range of differences in their properties depending on which molecular weight PEG is selected, how many PEGs are bound and whether the allosteric cofactors exist or not. Furthermore, DBBF intracross-linked pHbs are bound to various active PEG. As a result, with the combination of the three methods: DBBF intracross-linking, allosteric cofactors involving and PEG conjugating, a tetramer stable and high oxygen-carrying capacity pHb derivitive with large molecular weight is obtained.

Effects of Veratrum nigrum alkaloids on central catecholaminergic neurons of renal hypertensive rats

AIM

To study the central hypotensive mechanism of Veratrum nigrum L var ussurience Nakai alkaloids (VnA) in renal hypertensive rats(RHR).

METHODS

The quantitative method of immunocytochemistry (ICC) was used to observe and detect the effect of VnA (30 micrograms.kg-1, i.v.) on activity of central catecholaminergic (CA) neurons of C1, C2, A1, and A5 areas in RHR.

RESULTS

VnA increased the immunoreactivity (IR) of tyrosine 3-monooxygenase (TM)-immunopositive (IP) neurons of C1, C2, and A5 areas in RHR experimental group compared with RHR control group [positive units: (1.9 +/- 0.4), (1.18 +/- 0.23), (1.2 +/- 0.4) vs (0.15 +/- 0.22), (0.31 +/- 0.16), (0.69 +/- 0.20), respectively]; IR of TM-IP neurons of C1 and C2 areas in RHR control group was decreased compared with sham-operated group [positive units: (0.15 +/- 0.22), (0.31 +/- 0.16) vs (1.45 +/- 0.29), (1.36 +/- 0.25), respectively].

CONCLUSION

VnA increased the activity of central CA neurons in RHR to exert its hypotensive effect.

Plan-view imaging of oxygen-induced reconstruction on Ag(110) surface. I. The possibility of imaging surface oxygen

Surface reconstruction on Ag(110) induced by oxygen adsorption was studied by the plan-view imaging technique of high-resolution electron microscopy (HREM). Systematic multislice simulations were carried out to find the optimal experimental conditions for imaging the surface oxygen. It was found theoretically that there exist a series of characteristic values of objective lens defoci and sample thicknesses under which the surface and the bulk can be imaged clearly and simultaneously. These optimal imaging conditions were used to interpret the experimental micrographs. While the basic features of the surface reconstruction of O/Ag(110) in the HREM images are consistent with those revealed by scanning tunnelling microscopy (STM), there are some new features that have not been reported with STM. These phenomena give some evidence to the existence of subsurface oxygen.

Adaptive role of caloric intake on the degenerative disease processes

Carcinogenicity and aging are characterized by a set of complex endpoints, which appear as a series of molecular events. Many of these events can be modified by caloric intake. Since most of these processes determine an organism's ability to cope with various environmental stressors, it is not surprising that a relationship (in the presence of a constant nutrient density) exists between caloric intake and time-to-tumor and/or life span. Our studies have clearly shown that generally, the greater the caloric intake, the greater the body weight, the higher the incidence of spontaneous tumor occurrence, the greater the susceptibility to chemical carcinogens, and the shorter the life span. It is also recognized that variables other than body weight influence the life span and carcinogenesis. We have focused our attention on the questions of how and to what extent caloric intake modifies those homeostatic processes believed to be critical in determining the ability of an organism to cope with endogenous and exogenous stresses such as chemical, physical, and biological carcinogens. The response of an organism to its environment can be divided into four categories--physiological, metabolic, molecular, and cellular. We have found that, from a physiological perspective, decreasing caloric intake causes body temperature in rodents to be decreased by 0.5 to 1.8 degrees C and water consumption to be increased by 80%, as is running activity. However, metabolic output per gram of lean body mass is not altered. Reproductive capacity declines, whereas the ECG waveform is preserved as caloric intake decreases. Alterations in these and other physiological functions suggests that energy intake serves as a signal to up-regulate or down-regulate functions related to the flight-or-fight response observed in placental mammals. A number of key metabolic pathways are altered as a function of lowered caloric intake, even though the rate of food consumption per gram of lean body mass remains steady during body weight decreases caused by decreasing caloric intake. Pharmacological compartmentalization, however, is altered. As caloric intake declines, changes occur in the expression of a number of drug-metabolizing enzymes, with the most striking effect seen in sex-specific growth hormones and liver-dependent phase I and phase II enzymes. Additionally, oxidative stress (free-radical and mediated damage to macromolecules) appears to decrease as a function of reduced caloric intake. A number of molecular processes also change with changes in energy consumption. Our studies have shown that, regardless of the source and nature of DNA damage, DNA repair is better preserved and/or enhanced when caloric consumption decreases. In addition, the fidelity of DNA replication increases and oncogene expression is stabilized, P53 gene expression is increased, and apoptosis is elevated by up to 500% with decreased caloric intake. At the cellular level, cell proliferation is decreased in direct proportion to lower energy intake in some but not all tissues. Studies have also shown an enhancement in immune capacity, changes in IGF1, and accelerated rates of wound healing proportionate to declines in energy consumption. Our most recent findings, however, have shown that the benefits associated with decreases in caloric intake only occur in the presence of sufficient nutrient quality and density. In the absence of proper nutrition, however, sensitivity to carcinogens and toxic substances appears to be enhanced. These findings are supported by independent studies. These observations have led us to conclude that, in certain organisms, when caloric intake is decreased, there is an up-regulation of those processes that modulate the responses to a wide range of environmental stressors. This response allows for a better survival rate and a down-regulation of reproductive activity. It is our belief that, during periods of environmental stress, these systems may be essential to perpetu

A non-radioactive polymerase chain reaction method for diagnosis of Machado-Joseph disease

Machado-Joseph disease (MJD)/spinocerebellar ataxia type 3 (SCA3) is caused by unstable CAG trinucleotide repeat expansion in the coding region of the MJD gene. In this study, we describe a non-radioactive polymerase chain reaction (PCR) method to detect the CAG repeat range of the MJD gene. This technique allows direct visualization of the PCR products on ethidium bromide-stained agarose gels within hours. In this study, genomic DNA samples isolated from peripheral lymphocytes, amniotic fluid cells, and chorionic villi were tested with two sets of commonly used MJD primers. PCR conditions were optimized, which resulted in clear visualization of both the primer sets on 3% agarose gels. Ten out of 25 candidate MJD patients have been identified with this method to date, with no false-positive or false-negative diagnoses. This simple, reliable, and cost-effective method can be used for patient diagnosis, pre-symptomatic diagnosis, and prenatal diagnosis.

Identification of five spinocerebellar ataxia type 2 pedigrees in patients with autosomal dominant cerebellar ataxia in Taiwan

OBJECTIVES

The autosomal dominant cerebellar ataxias (ADCAs) are a group of genetically diverse neurological conditions linked by progressive deterioration in balance and coordination. Spinocerebellar Ataxia Type 2 (SCA2) is one of the ADCAs and also belongs to a special group caused by the expansion of an unstable CAG repeat encoding a polyglutamine tract. We aimed to investigate the frequency of SCA2 mutation in the ataxia patients referred to the clinic.

MATERIALS AND METHODS

We screened 58 families with inherent cerebellar ataxia and 57 normal individuals by the use of radioactive genomic polymerase chain reaction (PCR) method. A simple non-radioactive PCR for rapid detection of the expanded SCA2 alleles via agarose gel electrophoresis was also employed.

RESULTS

Eight SCA2 affected patients and 1 at-risk individual in 5 unrelated SCA2 families were identified. The CAG repeats of normal alleles in the sample studied range in size from 16 to 30 repeat units, while those of SCA2 chromosomes are expanded to 34 to 49 repeat units. Our results also showed that unlike SCA 1 and SCA3/MJD, the size distribution of the normal alleles showed few polymorphisms, with the 22 repeat allele accounting for 90.1%. Homozygosity in normal individuals was 80.2%. No overlap in ataxin-2 allele size between normal and expanded chromosomes was observed.

CONCLUSION

This is the first report of the SCA2 gene distributions in the population of Taiwan. The SCA2 mutation accounts for 8.6% of ADCA type I families referred to us, intermediate between SCA1(1.7%) and SCA3/MJD (24%) of the ADCA type I families in our collection.

A new anti-HBeAg lignan, kadsumarin A, from Kadsura matsudai and Schizandra arisanensis

A new C18 dibenzocyclooctadiene lignan, kadsumarin A (1) was isolated from Kadsura matsudai Hayata and Schizandra arisanensis Hayata. The anti-HBeAg test revealed that kadsumarin A had activity at a concentration of 40 micrograms/ml (= 90.1 microM). Its structural elucidation by spectral analysis was discussed in this note.

Prenatal fragile X detection using cytoplasmic and nuclear-specific monoclonal antibodies

We have been carrying out studies aimed at improving prenatal detection of the fragile X chromosome/mutation. Our current protocol requires a turnaround time (TAT) of several days. In an attempt to reduce the TAT, we have turned to the use of monoclonal antibodies (mAbs). Monoclonal antibody 1A1 (provided by Dr. Mandel of INSERM) immunostaining was performed according to a modified three-step immunocytochemical procedure. We found that cytoplasmic staining intensities, using mAb 1A1/avidin biotinylated complex/diaminobenzidine, varied from light to heavy within each sample, with controls exhibiting a majority of heavily stained cells in both chorionic villus (CV) sample and amniotic fluid cultured cells. Using mAb 1A1 and a new nuclear-specific antibody, mAb 3F11, we found that CV cultured cells harboring the FMR1 full mutation could be distinguished from controls as early as 10 weeks of gestation in both male and female specimens. Western blot analysis showed that the antibodies have similar staining patterns but that mAb 3F11 has fewer background/nonspecific bands. Our results demonstrate that it is feasible to detect fragile X full mutations within one day after obtaining cells from CV specimens taken as early as 10 weeks of gestation.

[Secretory expression of salmon calcitonin in Streptomyces lividans]

A gene coding for salmon calcitonin precursor (sCT-Gly) was amplified from salmon genomic DNA by Polymerase Chain Reaction (PCR) and fused to the expression and secretion signals of melC1 amplified by PCR. The fusion gene was cloned into the Streptomyces vector pIJ680 and expressed under the control of aminoglycoside phosphotransferase gene (aph) promoter. Streptomyces lividans TK54 transformed with the expression plasmid (pMS680) secreted biologically active sCT-Gly into the culture medium which was confirmed by Enzyme Immunoassay (EIA) and bioassay. Production of sCT-Gly by the recombinant strain in YEME medium reached a maximum of 100 micrograms/L culture at about 96 h. The recombinant sCT-Gly had almost the same HPLC retention time as the standard sCT obtained from Sigma.

Protein N-arginine methylation in adenosine dialdehyde-treated lymphoblastoid cells

Protein arginine methyltransferase was recently identified to be associated with some proteins in signal transduction pathways. N-Arginine methylation in RNA binding proteins with arginine- and glycine-rich RGG motifs is known to be the major protein methylation in cells. Considering that arginine methylation might be involved in certain human disorders, we used human lymphoblastoid cells that can be easily prepared from lymphocytes as a model system to study the methylation. Lymphoblastoid cells grown in the presence of 20 microM indirect methyltransferase inhibitor adenosine dialdehyde (AdOx) for 72 h appeared to accumulate high levels of hypomethylated proteins for the endogenous protein methyltransferase or recombinant glutathion S-transferase-fused yeast arginine methyltransferase (RMT1). Analysis of methyl-accepting polypeptides in AdOx-treated lymphoblastoid cells by SDS-PAGE and fluorography showed that many polypeptides between 29,000 and 90,000 Da were methylated by the endogenous methyltransferase. A few polypeptides could be methylated to a higher extent upon the addition of yeast GST-RMT1 fusion protein. A peptide (GGRGRGGGF) could compete for the majority of the methyl-accepting protein substrates in the AdOx-treated lymphoblastoid cell extracts, whether or not exogenous yeast RMT1 was included in the reaction. When the arginine residues in the peptide were replaced by lysine, no competition was observed. The results indicated that the protein methyl acceptors in lymphoblastoid cells share similar RGG motifs and that arginine residues should be the site of methylation.

Familial dup(5)(q15q21) associated with normal and abnormal phenotypes

We studied a familial dup(5q) present in a phenotypically normal father and his monozygotic twin daughters with different abnormal phenotypes. High-resolution chromosome analysis suggested that the duplicated segment was of region q15-21, which seems to be the smallest dup(5q) reported thus far. This dup(5q) was confirmed by fluorescence in situ hybridization with a chromosome 5 painting library and 5q cosmid clones. The presence of the dup(5q) in a normal father suggested that the duplication itself may be harmless. The anomalies in the twins may be due to processes other than this chromosome change.

Studies of the CAG repeat in the Machado-Joseph disease gene in Taiwan

Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar degeneration characterized by cerebellar ataxia and pyramidal signs associated in varying degrees with a dystonic-rigid extrapyramidal syndrome or peripheral amyotrophy. Unstable CAG trinucleotide repeat expansion in the MJD gene on the long arm of chromosome 14 has been identified as the pathological mutation for MJD. While investigating the distribution of CAG repeat lengths of the MJD gene in Taiwan's population, we have identified 18 MJD-affected patients and 12 at-risk individuals in seven families. In addition, we have analyzed the range of CAG repeat lengths in 96 control individuals. The CAG repeat number ranged from 13 to 44 in the controls and 72-85 in the affected and at-risk individuals. Our results indicated that the CAG repeat number was inversely correlated with the age of onset. The differences in CAG repeat length between parent and child and between siblings are greater with paternal transmission than maternal transmission. Our data show a tendency towards the phenomenon of anticipation in the MJD families but do not support unidirectional expansion of CAG repeats during transmission. We also demonstrated that PCR amplification of the CAG repeats in the MJD gene from villous DNA was possible and might prove useful as a diagnostic tool for affected families in the future.

Cytotoxic constituents from the stems of Diospyros maritima

One novel coumaric acid ester of lupeol, dioslupecin A (1), three naphthoquinones, 8'-hydroxyisodiospyrin (2), isodiospyrin (3), and plumbagin (4), three triterpenes, lupeol, lupenone and taraxerone, and four sterols, beta-sitosterol, stigmasterol, stigmast-4-en-3-one and ergosta-4,6,8(14),22-tetraen-3-one were isolated from the n-hexane extract of the stems of Diospyros maritima Blume. The structural determination of 1 was based on 1D and 2D NMR spectra (including 1H-1H COSY, 1H-13C COSY, and HMBC). All compounds were evaluated for in vitro cytotoxicity in 4 cancer cell lines. Compound 2 showed similar cytotoxicity against hepatoma (HEPA-3B, ED50 = 1.72 micrograms/ml), nasopharynx carcinoma (KB, ED50 = 1.85 micrograms/ml), colon carcinoma (COLO-205, ED50 = 2.24 micrograms/ml) and cervical carcinoma (HELA, ED50 = 1.92 micrograms/ml). Compounds 3 and 4 exhibited strong cytotoxicity against HEPA-3B, KB, COLO-205 and HELA (ED50 = 0.25, 1.81, 0.13 and 0.27 micrograms/ml for 3; ED50 = 0.87, 3.27, 0.56 and 0.35 micrograms/ml for 4, respectively.

Incidence of JC viruria is higher than that of BK viruria in Taiwan

To investigate the prevalence of human polyomaviruses in Taiwan, urine samples from immunocompetent (healthy), transient immunocompromised (pregnant), and prolonged immunosuppressed (autoimmune disease) individuals were collected throughout the island. The viral DNA in the urine was detected by the polymerase chain reaction (PCR) and Southern blot. The viral genotypes were determined by DNA sequencing within the regulatory region. The overall results, including cases reported previously, show that 13.3% (10/75) of immunocompetent individuals, 26.0% (20/77) of pregnant women, and 37.5% (18/48) of autoimmune disease patients are JCV positive. All of the immunocompetent individuals are BKV negative, but 3.9% (3/77) of the pregnant women and 6.2% (3/48) of autoimmune disease patients are BKV positive. Twenty-four percent (48/200) of the examined urine samples were JCV positive, but only 3% (6/200) were BKV positive. JCV positive individuals were mainly infected with CY (42%) and TW-1 (52%) subtypes. These results suggest that the incidence of urinary excretion of human polyomaviruses in immunosuppressed individuals is higher than that of immunocompetent individuals. The prevalence of JCV appears to be higher than that of BKV in Taiwan. In addition, CY and TW-1 are the predominant subtypes of JCV prevalent in the Taiwanese population.