NbPsbO1 Interacts Specifically with the Bamboo Mosaic Virus (BaMV) Subgenomic RNA (sgRNA) Promoter and Is Required for Efficient BaMV sgRNA Transcription

Many positive-strand (+) RNA viruses produce subgenomic RNAs (sgRNAs) in the infection cycle through the combined activities of viral replicase and host proteins. However, knowledge about host proteins involved in direct sgRNA promoter recognition is limited. Here, in the partially purified replicase complexes from Bamboo mosaic virus (BaMV)-infected tissue, we have identified the Nicotiana benthamiana photosystem II oxygen-evolving complex protein, NbPsbO1, which specifically interacted with the promoter of sgRNA but not that of genomic RNA (gRNA). Silencing of NbPsbO1 expression suppressed BaMV accumulation in N. benthamiana protoplasts without affecting viral gRNA replication. Overexpression of wild-type NbPsbO1 stimulated BaMV sgRNA accumulation. Fluorescent microscopy examination revealed that the fluorescence associated with NbPsbO1 was redistributed from chloroplast granal thylakoids to stroma in BaMV-infected cells. Overexpression of a mislocalized mutant of NbPsbO1, dTPPsbO1-T7, inhibited BaMV RNA accumulation in N. benthamiana, whereas overexpression of an NbPsbO1 derivative, sPsbO1-T7, designed to be targeted to chloroplast stroma, upregulated the sgRNA level. Furthermore, depletion of NbPsbO1 in BaMV RdRp preparation significantly inhibited sgRNA synthesis in vitro but exerted no effect on (+) or (-) gRNA synthesis, which indicates that NbPsbO1 is required for efficient sgRNA synthesis. These results reveal a novel role for NbPsbO1 in the selective enhancement of BaMV sgRNA transcription, most likely via direct interaction with the sgRNA promoter. IMPORTANCE Production of subgenomic RNAs (sgRNAs) for efficient translation of downstream viral proteins is one of the major strategies adapted for viruses that contain a multicistronic RNA genome. Both viral genomic RNA (gRNA) replication and sgRNA transcription rely on the combined activities of viral replicase and host proteins, which recognize promoter regions for the initiation of RNA synthesis. However, compared to the cis-acting elements involved in the regulation of sgRNA synthesis, the host factors involved in sgRNA promoter recognition mostly remain to be elucidated. Here, we found a chloroplast protein, NbPsbO1, which specifically interacts with Bamboo mosaic virus (BaMV) sgRNA promoter. We showed that NbPsbO1 is relocated to the BaMV replication site in BaMV-infected cells and demonstrated that NbPsbO1 is required for efficient BaMV sgRNA transcription but exerts no effect on gRNA replication. This study provides a new insight into the regulating mechanism of viral gRNA and sgRNA synthesis.

Nicotiana benthamiana Argonaute10 plays a pro-viral role in Bamboo mosaic virus infection

RNA silencing is a major defense mechanism against invading viruses in plants. Argonaute proteins (AGOs) are the key players in RNA silencing. The number of AGO family members involved varies depending on the plant species and they play distinct or sometimes redundant roles in antiviral defense. By using a virus-induced gene silencing technique, it was found that Nicotiana benthamiana AGO1 restricted Bamboo mosaic virus (BaMV) accumulation, but NbAGO10, the closest paralog of NbAGO1, positively regulated BaMV accumulation. Immunoprecipitation assay revealed BaMV virus-derived small interfering RNAs (vsiRNAs) in NbAGO10 complexes. Transient overexpression of NbAGO10 increased BaMV RNA accumulation, but with co-expression of NbAGO1, BaMV RNA accumulation was reduced, which suggests that NbAGO10 may have competed with NbAGO1 for sequestering BaMV vsiRNA and prevented the formation of RNA-induced silencing complexes. In addition, overexpression of NbAGO10 decreased BaMV vsiRNA accumulation. A host enzyme, small RNA degrading nuclease 1 (SDN1), also was found to interact with NbAGO10 on in vivo pull-down assay. Silencing of SDN1 elevated BaMV vsiRNA level and decreased BaMV RNA accumulation in N. benthamiana, indicating that NbAGO10 might recruit SDN1 for BaMV vsiRNA degradation. The results herein suggested that NbAGO10 plays a pro-viral role by BaMV vsiRNA sequestration and degradation.

Chloroplast Hsp70 Isoform Is Required for Age-Dependent Tissue Preference of Bamboo mosaic virus in Mature Nicotiana benthamiana Leaves

Plant viruses may exhibit age-dependent tissue preference in their hosts but the underlying mechanisms are not well understood. In this study, we provide several lines of evidence to reveal the determining role of a protein of the Nicotiana benthamiana chloroplast Hsp70 (NbcpHsp70) family, NbcpHsp70-2, involved in the preference of Bamboo mosaic virus (BaMV) to infect older tissues. NbcpHsp70 family proteins were identified in complexes pulled down with BaMV replicase as the bait. Among the isoforms of NbcpHsp70, only the specific silencing of NbcpHsp70-2 resulted in the significant decrease of BaMV RNA in N. benthamiana protopalsts, indicating that NbcpHsp70-2 is involved in the efficient replication of BaMV RNA. We further identified the age-dependent import regulation signal contained in the transit peptide of NbcpHsp70-2. Deletion, overexpression, and substitution experiments revealed that the signal in the transit peptide of NbcpHsp70-2 is crucial for both the import of NbcpHsp70-2 into older chloroplasts and the preference of BaMV for infecting older leaves of N. benthamiana. Together, these data demonstrated that BaMV may exploit a cellular age-dependent transportation mechanism to target a suitable environment for viral replication.

Evaluation of salivary function by sialoscintigraphy in locally advanced nasopharyngeal cancer patients after intensity modulated radiotherapy

PURPOSE

This study aimed to evaluate the salivary gland function changes by sialoscintigraphy in locally advanced nasopharyngeal cancer (NPC) after intensity modulated radiotherapy (IMRT).

MATERIALS AND METHODS

Salivary function was assessed by sialoscintigraphy. Quantitative sialoscintigraphy was performed in 24 NPC patients prior to and after IMRT. Results were categorized in four groups according to the duration of treatment. The sialoscintigraphy parameters were examined.

RESULTS

Sialoscintigraphy showed a significant difference in the secretion of each interval groups. The parameters of scintigraphy, except maximum accumulation (MA) of submandibular glands, decreased first after radiotherapy, and then recovered. However, the MA of submandibular glands was continuously downhill after radiation.

CONCLUSIONS

The sialoscintigraphy parameters of each gland changed with the different radiation dose and follow-up intervals. The salivary function was influenced after radiotherapy in locally advanced NPC, especially, in the submandibular gland. Strategies to improve the salivary function should be assessed.

Charge separation in donor-acceptor spiro compounds at metal and metal oxide surfaces investigated by surface photovoltage

Molecules with donor (diphenylamine) and acceptor moieties (dicyano or cyanoacrylic acid moieties) were linked by fluorene or spirobisfluorene cores and the chain length has been changed by introducing a thiophene group between fluorene and diphenylamine. Four different kinds of fluorene and spirobisfluorene compounds were adsorbed from highly diluted solutions at ultra-thin nanoporous TiO2 (np-TiO2), Au and ITO surfaces. Charge separation has been investigated by surface photovoltage spectroscopy in the fixed capacitor and Kelvin probe arrangements in vacuum. Striking differences between the interaction of linking (dicyano or cyanoacrylic moieties) and different substrates were observed. Intra-molecular charge separation and electron injection have been distinguished and the directed adsorption of spiro compounds was deduced.

Genetic variability in copper-transporting P-type adenosine triphosphatase (ATP7B) is associated with Alzheimer's disease in a Chinese population

Previous experiments demonstrated that transgenic mice carrying both amyloid precursor protein and mutant ATP7B transgenes reduce amyloid plaques and diminish plasma Abeta levels. These experiments showed that a structural change of ATP7B may affect Alzheimer’s disease (AD) susceptibility. In this study three missense SNPs in ATP7B gene (rs1801243, rs1801244, and rs1801249) were chosen to test whether they were associated with AD. We tested this hypothesis using a case control design. The experimental data showed that there was a significant deviation from Hardy-Weinberg equilibrium (HWE) for SNP rs1801249 (c.3419 T greater than C, Val1140Ala) in the case group (p = 0.014) but not in the control group and that there was an association between SNP rs1801249 and AD under a recessive model (p = 0.003). The data also showed that the genotype frequency distribution of the ATP7B c.1366 G greater than C polymorphism (rs1801244, Val456Leu) differed significantly between the AD patients and the normal subjects (p = 0.012). In addition, the frequency of the TGC haplotype of SNPs rs1801243, rs1801244, and rs1801249 was significantly higher in the AD patients compared with the normal subjects (p = 8.49×10-7). These observations suggested that genetic variations in the copper transporter gene ATP7B might contribute to AD pathogenesis in the Taiwanese population.

Association analysis of dopaminergic gene variants (Comt, Drd4 And Dat1) with Alzheimer s disease

Defects in dopaminergic transmission play important roles in the disturbance of synaptic plasticity and even in advanced cognitive behavior. However, the relationship between genes involved in the regulation of dopamine levels and predisposition for Alzheimer s disease (AD) remains unclear. The potential association of dopamine-modulating gene polymorphisms with AD was evaluated. We performed a case-control study with 120 patients and 86 healthy controls. Two catechol-O-methyltransferase (COMT) single-nucleotide polymorphisms (SNPs) (rs2020917 and rs4646312), two dopamine D4 receptor (DRD4) SNPs (rs3758653 and rs916455), and four dopamine transporter (DAT1) SNPs (rs2937639, rs6347, rs12516948 and rs11133762) were investigated. The T allele at the DRD4 SNP (rs3758653) was found to be significantly associated with AD. Our results also showed that haplotype frequencies, observed from the analyzed SNPs, were distributed significantly differently in AD patients vs control subjects. Moreover, a strong association was observed between the A allele at rs6347 of DAT1 and moderate stage of dementia. These observations suggest that genetic variations in the dopamine-modulating genes, COMT, DRD4 and DAT1, may contribute to AD pathogenesis in the Taiwanese population.

Hsp90 interacts specifically with viral RNA and differentially regulates replication initiation of Bamboo mosaic virus and associated satellite RNA

Host factors play crucial roles in the replication of plus-strand RNA viruses. In this report, a heat shock protein 90 homologue of Nicotiana benthamiana, NbHsp90, was identified in association with partially purified replicase complexes from BaMV-infected tissue, and shown to specifically interact with the 3' untranslated region (3' UTR) of BaMV genomic RNA, but not with the 3' UTR of BaMV-associated satellite RNA (satBaMV RNA) or that of genomic RNA of other viruses, such as Potato virus X (PVX) or Cucumber mosaic virus (CMV). Mutational analyses revealed that the interaction occurs between the middle domain of NbHsp90 and domain E of the BaMV 3' UTR. The knockdown or inhibition of NbHsp90 suppressed BaMV infectivity, but not that of satBaMV RNA, PVX, or CMV in N. benthamiana. Time-course analysis further revealed that the inhibitory effect of 17-AAG is significant only during the immediate early stages of BaMV replication. Moreover, yeast two-hybrid and GST pull-down assays demonstrated the existence of an interaction between NbHsp90 and the BaMV RNA-dependent RNA polymerase. These results reveal a novel role for NbHsp90 in the selective enhancement of BaMV replication, most likely through direct interaction with the 3' UTR of BaMV RNA during the initiation of BaMV RNA replication.

Remodeling of rabbit abdominal aorta and Cx43 gap junctions after stent placement: effect of balloon injury plus cholesterol-enriched diet

AIM

To examine the effect of stenting and cholesterol-enriched diet (CED) on vascular remodeling, including the expression of connexin43 (Cx43) gap junctions in smooth muscle cells (SMC).

METHODS

Rabbits abdominal aortae were either implanted stent made of 316 stainless steel (group 1) or denuded followed by stent placement 28 days later (groups 2 and 3). Animals were given normal chow except those of group 3, which were fed CED after the denudation. Eight weeks later, the development of neointima and the expression of connexin43 (Cx43) were examined. In parallel, human aortic SMC were grown on 316 stainless steel or treated with C-reactive protein (CRP) followed by analysis of Cx43.

RESULTS

The results showed that, serum CRP levels became transiently elevated after denudation and stent implantation. For the stented aortic segments, the dimensions of neointima were group 3 > group 2 > group 1 (P<0.05). In groups 1 and 2, Cx43 gap junctions are less in amount in neointima of the stented segment, compared to the unstented upstream neointima or medial layer (all P<0.01). In culture experiments, Cx43 in SMC grown on stent material was up-regulated in growth medium but down-regulated in differentiation medium, and CRP did not affect Cx43 expression.

CONCLUSION

Vascular remodeling post stent implantation varied according to the presence of balloon injury, CED, or both. Cx43 expression in SMC is altered after exposure to stent and the regulation depended on the milieu.

Matrix metalloproteinase-12 leads to elastin degradation in BALB/c mice with eosinophilic meningitis caused by Angiostrongylus cantonensis

The rat lugworm Angiostrongylus cantonensis can cause eosinophilic meningitis. The purpose of this study was to determine whether matrix metalloproteinase (MMP)-12 and its substrate elastin participate in this inflammatory response. We showed that the MMP-12/tissue inhibitor of metalloproteinase-1 ratio was significantly increased in the CSF of A. cantonensis-infected mice from day 10 p.i., and reached high levels on days 20 and 25 p.i. MMP-12 production was correlated with elastin degradation, eosinophil count, blood-CSF barrier permeability and pathological changes in the subarachnoid space. Also, MMP-12 might contribute to elastin degradation in the meningeal vessel of the subarachnoid space. Simultaneous administration of albendazole and doxycycline significantly reduced the levels of MMP-12, elastin and Evans blue in mice with meningitis. These results imply that MMP-12 contributes to the elastin degradation that occurs in angiostrongyliasis meningitis, and doxycycline can reverse related inflammatory events by inhibition of MMP-12.

Genetic polymorphisms of the DNA repair gene MPG may be associated with susceptibility to rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease and can lead to deformities and severe disabilities, due to irreversible damage of tendons, joints, and bones. A previous study indicated that a DNA repair system was involved in the development of RA. In this study, we investigated the association of four N-methylpurine-DNA glycosylase (MPG) gene polymorphisms (rs3176364, rs710079, rs2858056, and rs2541632) with susceptibility to RA in 384 Taiwanese individuals (192 RA patients and 192 control subjects). Our data show a statistically significant difference in genotype frequency distributions at rs710079 and rs2858056 SNPs between RA patients and control groups (P = 0.040 and 0.029, respectively). Our data also indicated that individuals with the GG genotype at rs2858056 SNP may have a higher risk of developing RA. In addition, compared with the haplotype frequencies between case and control groups, individuals with the GCGC haplotype appeared to be at a greater risk of RA progression (P = 0.003, OR = 1.75; 95&percnt; CI = 1.20-1.55). Our results suggest that rs710079 and rs2858056 polymorphisms and the GCGC haplotype in the MPG gene are associated with the risk of RA progression, and thus may be used as molecular markers of RA if they are confirmed by further research.

Faceted ice growth in hydrophilic and hydrophobic channels

This study is motivated by the cryo-preservation for tissues, which is related to the solidification of blood in a confined space. The morphological behavior of growing ice facet in 1.3 mm hydrophilic and hydrophobic channels is the focus of this study. Both DI water and KCl solution were solidified without seeds in the channels and the growing front facet was discussed in regards to contact angle, in-situ morphology, conductivity difference between two phases and solute segregation. For DI water, the formation of facets was observed during ice growth in both hydrophilic and hydrophobic channels and could be classified into two modes according to the local curvature of the interface. The facet was formed at different positions of the interface in hydrophilic and hydrophobic channels. Solutal segregation effect was taken into consideration to partially govern the interface morphology and the facet formation during solidification of the KCl solution. In addition, the growth rates of the ice growth with a facet were also compared and discussed.

The involvement of insulin receptor genotypes in pre- and co-obese acanthosis Nigricans children and adolescent

Acanthosis nigricans (AN) is most commonly related to obesity as a manifestation of cutaneous insulin resistance in children and adolescents, while the interaction and time course between AN and obesity and detailed mechanism for the pre- and co-obese appearance of AN (PCOAN) in child are unclear. In this study, the involvement of insulin receptor in child PCOAN was investigated via studying the association of polymorphisms of INSR gene with PCOAN. In total, 99 children with PCOAN and 100 healthy controls recruited were genotyped and analyzed by PCR-RFLP method. Significantly different distributions were found in the frequency of the INSR His1085His genotypes, but not in other INSR genotypes, between the two groups. Our results provide not only the evidence that the T allele of INSR His1085His is correlated with the appearance of PCOAN but revealed that the insulin receptor pathway may play an important role in this PCOAN.

Analysis of ERCC2/XPD functional polymorphisms in systemic lupus erythematosus

Sunlight/ultraviolet (UV) irradiation has been recognized as an important risk factor for developing systemic lupus erythematosus (SLE). However, the interpretation of genetic variations involved in UV-light sensitivity is largely unknown. Recent studies indicated that two genetic variations of ERCC2/XPD gene (rs1799793 in exon 10 and rs13181 in exon 23) have been found to exert negative influences on nucleotide excision repair system. To analyse the possible contribution of the ERCC2/XPD functional single nucleotide polymorphisms in genetic susceptibility to SLE, the rs13181 and rs1799793 SNPs in ERCC2/XPD were genotyped by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Association was studied by case-control analyses using samples from 172 SLE patients and 160 healthy controls. Haplotype analysis was performed to detect the association with genetic predisposition to SLE and the clinical features. Although these two functional genetic variations are linked to several immune dysfunction-induced diseases, no statistically significant differences in allele or genotype frequencies were observed between SLE patients and controls. Haplotype analysis showed that none of ERCC2/XPD haplotypes was associated with the incidence of SLE disease, nor the preference of clinical features. In conclusion, the ERCC2/XPD functional polymorphisms analysed in this study showed no association in genetic susceptibility to SLE.

Morphology and mechanical behavior of TTCP-derived calcium phosphate cement subcutaneously implanted in rats

A pre-hardened, TTCP-derived CPC was immersed in Hanks' solution as well as subcutaneously implanted into abdomen of rats. The implant-soft tissue interfacial morphology was examined and properties of the CPC were evaluated and compared under in vitro and in vivo conditions. The results indicate that the surface of immersed samples appeared rougher and more porous than that of implanted samples and was covered with a layer of fine apatite crystals. The CPC samples implanted for 4 weeks or longer were surrounded by a layer of fibrous tissue, which was further surrounded by a soft tissue capsule comprising numerous fat cells. The soft tissue capsule had a non-uniform distribution in thickness, which increased most significantly between 4 weeks and 12 weeks after implantation. None of polymorphic cells, osteoblast cells or bone cells adjacent to the implant were observed. The majority of original TTCP powder was transformed into apatite after 1 day of either immersion in Hanks' solution or implantation. The average porosity values of samples immersed in Hanks' solution for 4 weeks or longer were significantly larger than those immersed for 1 day or 1 week. The porosity values of samples implanted for different times were not significantly different. The DTS values of Hanks' solution-immersed samples largely decreased after a few weeks of immersion. The implanted samples maintained their strengths throughout the study.

Intrapericardial isolation of the inferior vena cava through a transdiaphragmatic pericardial window for tumor resection without sternotomy or thoracotomy

AIMS

The prognosis for patients with advanced tumors invading the inferior vena cava (IVC) is dismal and surgical treatments for these tumors are challenging. A surgical approach that avoids sternotomy and thoracotomy for tumors invading the IVC even to the level of the hepatocaval junction would be extremely helpful.

METHODS

The intrapericardial IVC was isolated via a transdiaphragmatic pericardial window using a transabdominal approach. Hepatectomy was then applied via an anterior approach until the IVC was seen. Total hepatic vascular exclusion was achieved by clamping the portal triad, intrapericardial IVC and infrahepatic IVC. We removed the primary tumor, the liver portion involved and the tumor thrombi, with segmental resection of the IVC. Vascular continuity was reestablished using a 20-mm-diameter polytetrafluoroethylene graft.

RESULTS

Four patients with tumors invading the IVC were treated with this method. All underwent gross en-bloc tumor resections and all survived.

CONCLUSION

This method for the resection of IVC tumors could avoid emboli dislodging from the tumor thrombi, prevent the complications of sternotomy, cardiopulmonary bypass and shorten operative times.

Amino acid concentrations in cerebrospinal fluid in children with acute lymphoblastic leukemia undergoing chemotherapy

Cerebrospinal fluid (CSF) amino acid concentrations were measured in 45 children with acute lymphoblastic leukemia (ALL). Central nervous system (CNS) disease was absent in 34 and present in 11 (Groups L and M, respectively) at diagnosis. Thirty-two otherwise healthy children with febrile convulsions were studied for comparison. Results from this study show that glutamine levels at Day 0 were significantly higher in patients than in controls. Patients in Group M had elevated glutamine levels compared to Group L. In comparison, at Day 14, concentrations of glutamine and asparagine decreased, while glutamic acid amounts increased significantly in Group L. Glutamine levels fell at Day 42 in Group M, which may have resulted from more intensive treatment. From this study we hypothesise that higher baseline glutamine levels are indicative of a greater risk for CNS leukemia. Large-scale prospective trials are required to confirm increased baseline CSF glutamine levels in ALL patients, to identify glutamine as a marker for CNS disease and to clarify underlying mechanisms regulating glutamine in ALL.

Increase in laminin expression in allergic airway remodelling and decrease by dexamethasone

Lung expression of the extracellular matrix protein, laminin, and its receptor, laminin-1 receptor, were examined in a mouse model of asthma with airway remodelling. Ovalbumin (OVA) was administered to BALB/c mice, intraperitoneally on days 0 and 14, and intranasally periodically between days 14 and 75. The mice developed airway eosinophil and mononuclear inflammatory cell infiltration and fibrosis. On day 76, a marked increase in total laminin was seen in the airways of OVA-treated mice compared to controls by Western blot analysis. The increased laminin expression was detected immunocytochemically in the thickened subepithelial basement membrane and around airways and blood vessels. The OVA-treated mice showed increased expression of the alpha1, beta1, and gamma1 chains of the laminin-1 isoform in monocytes, macrophages and eosinophils infiltrating the airways. Laminin-1 receptor expression was increased in inflammatory and endothelial cells in the lungs of OVA-treated mice compared to controls. Treatment of OVA-sensitised/challenged mice with dexamethasone reduced airway expression of laminin and laminin-1 receptor in OVA-treated mice but not airway hyperresponsiveness to methacholine. Laminin deposition may be an important component of the airway remodelling observed in chronic allergic lung inflammation and is a process modulated by corticosteroids.

Usefulness of 99mTc ethyl cysteinate dimer brain SPECT to detect abnormal regional cerebral blood flow in patients with acute carbon monoxide poisoning

99mTc ethyl cysteinate dimer (99mTc-ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in patients with acute carbon monoxide (CO) poisoning. Ten patients with acute CO poisoning and no past histories of psychoneurological disorders were enrolled in this study. After oxygen treatment, all of the 10 patients were investigated using 99mTc-ECD brain SPECT and brain computed tomography (CT) scan. Brain CT scan findings were normal in all of the 10 patients. 99mTc-ECD brain SPECT showed the hypoperfusion lesions of the basal ganglia and brain cortex in five and seven patients, respectively. Only three of the 10 patients had normal 99mTc-ECD brain SPECT findings. This study suggests that, in comparison with brain CT scan, 99mTc-ECD brain SPECT is a better tool for the early detection of hypoperfusion brain lesions in acute CO poisoning in patients with normal brain CT findings.

Interleukin-1 receptor antagonist gene polymorphism in Taiwanese patients with gout

OBJECTIVE

The purpose of this study was to examine whether interleukin-1 receptor antagonist (IL-1Ra) gene polymorphism is a marker of susceptibility to or of the clinical characteristics of gout in Taiwanese patients.

METHODS

196 Taiwanese patients with gout and 103 unrelated normal healthy control subjects living in central Taiwan were studied. Polymorphism of the gene for IL-1Ra was typed from genomic DNA. Allelic frequencies and carriage rates were compared between gout patients and control subjects. The relationship between IL-1Ra genotypes and the clinical characteristics of gout was also evaluated.

RESULTS

No significant differences were observed in genetic and allelic frequencies of the IL-1Ra gene polymorphism between patients with gout and healthy control subjects. Furthermore, we did not detect any association of IL-1Ra genotype with the clinical and laboratory profiles in patients with gout.

CONCLUSION

The results from the present study suggest that the interleukin-1 receptor antagonist gene polymorphism is not a genetic marker of susceptibility to gout for Taiwanese. Furthermore, our study also suggests that the IL-1Ra gene polymorphism is unrelated to the clinical characteristics of gout.

Two novel mutations of the glycine receptor gene in a Taiwanese hyperekplexia family

The authors report a Taiwanese family with autosomal recessive hyperekplexia. Two novel mutations, W96C (from the paternal allele) and R344X (from the maternal allele), which are located in exon 4 and exon 7 of the GLRA1 gene, were identified in this family. A series of electrophysiologic investigations were conducted in one of the probands, and the results suggest that the "startle center" is located subcortically.

Comparison of quantitative 99mTc-HMPAO and 67Ga citrate lung scans in patients with active diffuse infiltrative lung disease

Diffuse infiltrative lung disease (ILD) is a heterogeneous group of disorders that predominantly affect the lung parenchyma and spare the airway. To objectively assess the degree of pulmonary vascular endothelium damage in active ILD, lung/liver uptake ratios (L/L ratios) on 99mTc hexamethylpropylene amine oxime (99mTc-HMPAO) lung scans were determined in 21 patients with active ILD. Meanwhile, the 67Ga citrate uptake index (GUI) on 67Ga lung scans was measured in order to evaluate the severity of lung inflammation in active ILD. The results show there were statistically significant differences between normal controls and patients with active ILD, as shown in the L/L ratio and GUI. However, when the patients were divided into two groups: (1) eight patients with normal chest X-ray findings, and (2) 13 patients with abnormal X-ray findings, there was no significant difference between groups 1 and 2 for the results of L/L ratio and GUI. In addition, no correlation between the degree of damage to the pulmonary vascular endothelium and the severity of lung inflammation was found. In conclusion, L/L ratios on 99mTc-HMPAO lung scans and GUI on 67Ga lung scans are different to the findings of chest X-rays and have the potential to objectively detect the degree of damage to the pulmonary vascular endothelium and the severity of lung inflammation in active IDL. However, the relationship between L/L ratio and GUI in active ILD is not significant.

Association between urokinase gene 3'-UTR T/C polymorphism and Chinese patients with rheumatoid arthritis in Taiwan

OBJECTIVES

The purpose of this study was to investigate whether the urokinase gene 3'-UTR C/T polymorphism is a marker of susceptibility to or severity of rheumatoid arthritis (RA) in Chinese patients.

METHODS

A total of 145 RA patients and 134 healthy control subjects were enrolled in this study. We identified the C/T polymorphism of the urokinase gene, which is mapped on the 3'-untranslated region (3'-UTR) on chromosome 10 by polymerase chain reaction (PCR).

RESULTS

There were significant differences in the distribution of the urokinase gene 3'-UTR C/T polymorphism frequency between RA patients and subjects in the control group. However, we did not detect an, association between the urokinase gene 3'-UTR C/T polymorphism and rheumatoid factor (RF), extraarticular involvement or bone erosion in RA patients.

CONCLUSION

The urokinase gene 3'-UTR "T" allele was associated with RA in Chinese patients in Taiwan.

Simultaneously evaluating the effects of one-week fluticasone propionate inhalation therapy on lung ventilation and permeability in children with asthma

This study evaluated the effects of fluticasone propionate inhalation therapy on lung ventilation and alveolar permeability by quantitative Tc-99m DTPA radioaerosol inhalation lung scintigraphy in 15 children with asthma. Lung ventilation was evaluated as the distribution percentage (D%) of Tc-99m DTPA radioaerosols in the central, intermediate and peripheral regions of the right lung. Alveolar permeability was measured by the rate of Tc-99m DTPA radioaerosol clearance curve from the peripheral alveoli of the right lung and represented as slope. The D% and slopes were calculated before and after one-week inhalation therapy (100 microg fluticasone propionate two times daily for one-week) to evaluate the effects of inhalation therapy on lung ventilation and alveolar permeability. The preliminary results revealed statistically significantly improved lung ventilation but no significant change of alveolar permeability in the right lung after one-week fluticasone propionate inhalation therapy in children with asthma. We suggest that the widely available and noninvasive Tc-99m DTPA radioaerosol inhalation lung scintigraphy can simultaneously evaluate lung ventilation and alveolar permeability in one study and should contribute to any disorder involving both alveoli and airways.

Combined therapy with deferiprone and desferrioxamine successfully regresses severe heart failure in patients with beta-thalassemia major

Cardiac complications caused by iron deposition are major causes of death in patients with beta-thalassemia major. Deferiprone (L1) was found to have greater efficacy at depleting myocardial iron than desferrioxamine (DFX). Furthermore, combined therapy with L1 and DFX produced an additive or synergistic iron chelating effect. We report the successful treatment of severe heart failure in two patients with beta-thalassemia major with the combined therapy. Magnetic resonance images showed a marked recovery of signal intensity in the heart, indicating a significant reduction of iron load in the heart. No significant adverse effects were noted. Therefore, combined therapy with L1 and DFX should be considered in patients with beta-thalassemia major and cardiac complications.

Detecting abnormal regional cerebral blood flow in patients with primary Sjögren's syndrome by technetium-99m ethyl cysteinate dimer single photon emission computed tomography of the brain--a preliminary report

Technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in 32 female patients with primary Sjögren's syndrome (PSS) showing definite neuropsychiatric symptoms/signs and normal brain magnetic resonance imaging (MRI) findings. It demonstrated hypoperfusion brain lesions in 18 (56.3%) of the patients, most frequently in the parietal lobes, and appears to be a sensitive tool for this clinical application.

Hydrops foetalis caused by anti-Mur in first pregnancy--a case report

Anti-'Mia' is the most common alloantibody of potential clinical significance in the Taiwanese population. The Mi.III phenotype is rare among Caucasians but has a high incidence in various Oriental populations. We describe a nulliparous woman with no history of transfusions, who had hydrops foetalis at 28 weeks gestation. Foetal haemoglobin was 4.4 g dL-1, and a positive direct antiglobulin test was positive in the foetal blood. Intrauterine intravascular transfusion was given, and the baby was discharged healthy. Anti-'Mia' was identified in the maternal serum, the cord blood serum and the eluate from red cells of the cord blood. Anti-'Mia' in the maternal serum was confirmed to be anti-Mur. The polymerase chain reaction-restriction fragment length polymorphism method confirmed that both the baby and her father had the Mi.III gene. Therefore, our report documents that anti-Mur has the potential to cause hydrops foetalis.

Objective evidence of abnormal regional cerebral blood flow in patients with systemic lupus erythematosus on Tc-99m ECD brain SPECT

Technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in 78 SLE patients with neuropsychiatric manifestations. These patients were separated into two subgroups: group 1 including 48 cases with definite neuropsychiatric symptoms/signs and group 2 with 30 cases having no neuropsychiatric symptoms/signs. Tc-99m ECD brain SPECT demonstrated hypoperfusion brain lesions in 90% and 20% of patients in groups 1 and 2, respectively. In both groups, parietal lobe and cerebellum are the most and least common areas with hypoperfusion lesions, respectively. This study suggests that Tc-99m ECD brain SPECT may provide objective information for detection of hypoperfusion brain lesions in SLE patients.

Environmental risk factors of young onset Parkinson's disease: a case-control study

While the cause of Parkinson's disease (PD) remains unknown, recent evidence suggests certain environmental factors, such as well water drinking, herbicides and pesticides exposure, and neurotoxins, may trigger the chain of oxidative reactions culminating in the death of dopaminergic neurons in substantia nigra to cause parkinsonism. Most studies to date focused on PD with old age onset. However, there is a peculiar group of parkinsonian patients, the young onset Parkinson's disease (YOPD), in whom the age of onset is before 40. It is intriguing to know whether earlier exposure to the putative neurotoxin(s) may contribute to the earlier onset. We therefore conducted this case-control study in which 60 PD patients, 30 YOPD patients and the same number of age- and sex-matched young controls were included. Using logistic regression, we found well water drinking and head injury were risk factors for the development of YOPD. When YOPD patients were compared with PD, we found head injury and exercise were the significant predictors. Keeping all other variables constant, head injury was a risk factor and exercise appeared to be a protective factor. We conclude early exposure to well water drinking and head trauma may trigger and expedite the appearance of parkinsonian features, but such acceleration may be prevented through regular exercise.

Heterogeneity of myocardial sleeve morphology and gap junctions in canine superior vena cava

BACKGROUND

The myocardial sleeve of the superior vena cava (SVC) has been identified as a potential initiating focus in atrial fibrillation, but information on cell-to-cell linkage at this site is lacking.

METHODS AND RESULTS

We examined the SVC in 8 dogs by immunoconfocal and electron microscopy. Cardiomyocytes outlined with vinculin and bearing striations positive for alpha-actinin are found in the proximal segment of the SVC. These cells, grouped in bundles of various orientations according to location, extend cephalically as far as 3 cm from the right atrium (RA)-SVC junction. Comparison between the junctional level and the level 2 cm distal shows that the myocardial layer in the latter is thinner and not as compact and is composed of longer cells (87.3+/-15.7 versus 71.6+/-14.4 micrometer, P<0.01). Gap junctions made of connexin43 (Cx43), Cx40, and Cx45 are aggregated mainly at the intercalated disks, and colocalization of connexins is a common feature throughout the myocardial sleeve. Areas of atypical expression exist, however, characterized by a center of abundant Cx43 labels surrounded by a periphery of scattered tiny Cx40-labeled spots. Although in the ventral subluminal compact myocardial layer, individual cells at both levels are surrounded by similar numbers of cells, the number of aggregation of labeled gap junctions at the distal level is less (2.3+/-0.6 versus 3.7+/-0.9, P<0.01). In addition, electron-microscopic examination demonstrates that the gap junctions at the distal level are smaller in size (0.37+/-0.30 versus 0.55+/-0.34 micrometer, P<0.01).

CONCLUSIONS

The myocardial sleeve in the canine SVC is a heterogeneous structure, which could potentially form a substrate for heterogeneity of electrical coupling.

Relation of BsmI vitamin D receptor gene polymorphism to bone mineral density and occurrence of osteoporosis in postmenopausal Chinese women in Taiwan

Osteoporosis is a common disorder with a strong genetic component. Our aim was to evaluate the correlation of the vitamin D receptor gene intron 8 BsmI polymorphism with bone mineral density (BMD) and their relationship to osteoporosis. We determined the vitamin D receptor gene intron 8 BsmI polymorphfsm using polymerase chain reaction-based restriction analysis in 171 postmenopausal Chinese women in Taiwan. The polymorphism was detected using the restriction enzyme BsmI, where the B allele indicated absence of the cuttable site and the b allele its presence. BMD of the lumbar spine and proximal femur were measured using dual-energy X-ray absorptiometry. The allelic frequencies for postmenopausal Chinese women in Taiwan were 12.3% for B and 87.7% for b in BsmI restriction fragment length polymorphisms. The prevalence of each genotype in the study population was: 6.4% BB, 11.7% Bb and 81.9% bb. The three genotypic groups differed significantly in BMD at the lumbar spine and the femoral neck. These differences corresponded to significant gene-dose effects at the lumbar spine and femoral neck (p<0.001 for both sites). The relative risk for the development of osteoporosis was about 2-3 times as great as that predicted by the differences between genotypes in BMD, and remained significant even after adjustment for age, height and weight. The vitamin D receptor gene intron 8 BsmI polymorphism is associated with reduced BMD and predisposes women to osteoporosis.

Syntactic priming of nouns and verbs in Chinese

Syntactic priming of Chinese nouns and verbs was investigated in word recognition (cued shadowing of auditory targets) and production (picture naming). Disyllabic compound words were presented after syntactically congruent, incongruent, or neutral auditory contexts, with a zero delay between offset of the context and onset of the target. Significant priming was observed in both tasks, including facilitation as well as inhibition. Post hoc analyses showed that reaction times were also affected by sublexical variables that are especially relevant for Chinese, including syllable density (number of word types and tokens in the language with the same first or second syllable) and semantic transparency (whether the meaning of the whole word is predictable from the separate meanings of the two syllables within the compound). These patterns suggest competitive effects at the sublexical level. Implications for interactive models of lexical access are discussed.

Mutation analysis of a family with hereditary hemorrhagic telangiectasia associated with hepatic arteriovenous malformation

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by multisystemic vascular dysplasia. Two related genes, endoglin and activin receptor-like kinase (ALK-1), have been mapped to chromosomes 9q34 and 12q13, respectively. We describe a Taiwanese HHT family with hepatic arteriovenous malformation. Clinical and molecular evaluations were performed in eight members of this family, and HHT symptoms were found in three adults. Short tandem repeat markers were used to perform linkage analysis, and this family was classified as HHT type 2 (ALK-1 gene). The exons of ALK-1 were amplified using the polymerase chain reaction and subjected to direct DNA sequencing. The mutation causing the disease was located at ALK-1 codon 411, causing an arginine to glutamine substitution. Five members of this family carried the mutated ALK-1 gene. This investigation successfully used linkage and sequencing techniques to perform molecular diagnosis of HHT.

Connexin37 gene polymorphism and coronary artery disease in Taiwan

BACKGROUND

A recent study shows that a C1019T polymorphism of the gene encoding the gap junction protein connexin37 contributes to the genesis of atherosclerotic plaques in human carotid artery. However, whether such a polymorphism can be used as a prognostic marker in atherosclerotic disease of other arterial sites, such as coronary artery disease, is not known.

METHODS

We analyzed the allelic status in 177 subjects with coronary artery disease (age, 61+/-11 years; male/female, 120/57) and 102 controls (60+/-11 years; male/female, 70/32). Both groups were matched, before genotype analysis, for a variety of other traditional risk factors, including body mass index, smoking status, levels of blood pressure, sugar, creatinine, and lipid profiles, in addition to age and sex.

RESULTS

The T allele was less frequently seen in the control group, compared to the disease group (10.7 vs. 20.1%, TT+TC vs. CC, P<0.01). Subsequent analysis demonstrated that a significant difference existed in the male (9.2 vs. 22.8%, TT+TC vs. CC, P<0.005), but not in the female. Another finding was that the T allele frequency in all participants was less than 15%, markedly lower than that reported in non-Taiwanese.

CONCLUSIONS

The observation indicates that the polymorphism in the connexin37 gene potentially plays a role in the manifestation of coronary atherosclerosis in Taiwan.

Relation of the estrogen receptor alpha gene microsatellite polymorphism to bone mineral density and the susceptibility to osteoporosis in postmenopausal Chinese women in Taiwan

OBJECTIVE

Osteoporosis is a common disorder with a strong genetic component. Our aim was to investigate the correlation of the estrogen receptor alpha gene microsatellite polymorphism (TA dinucleotide repeat polymorphism 5' upstream of exon 1) with bone mineral density and their relationship to osteoporosis.

METHODS

We determined the estrogen receptor alpha gene microsatellite polymorphism using polymerase chain reaction-based microsatellite analysis in postmenopausal Chinese women in Taiwan. Bone mineral density of the lumbar spine and proximal femur were measured using dual-energy X-ray absorptiometry.

RESULTS

The ERalpha genotype was classified into '12' through '27' according to the number of TA dinucleotide repeats they contained, as a 'signpost'. After adjustment for potential confounding factors including age, height, and weight, subjects with genotype 18+ (n=4) had lower bone mineral density values and a 54.5 times greater risk for osteoporosis when compared with subjects with genotype 18- (n=170) at the lumbar spine. This should be interpreted with caution because of the small number of subjects with the unfavorable genotype 18+. According to mean number of TA dinucleotide repeats, women with a high number of repeats (TA > or =20) (n=38) had the lowest bone mineral density and a 6.1 times greater risk for osteoporosis than women with a low number of repeats (TA < or =15) (n=61) at the femoral neck, after adjustment for potential confounding factors such as age, height, and weight.

CONCLUSION

The present study suggests that the estrogen receptor alpha gene microsatellite polymorphism may be a candidate genetic marker for risk of osteoporosis in postmenopausal Chinese women in Taiwan.

The partial purified RNA-dependent RNA polymerases from bamboo mosaic potexvirus and potato virus X infected plants containing the template-dependent activities

RNA-dependent RNA polymerases (RdRp) isolated from bamboo mosaic potexvirus (BaMV) and potato virus X infected Nicotiana benthamiana plants and solubilized with the detergent NP-40, generated a full-length genomic and two subgenomic double-stranded RNAs of respective viruses in an in vitro RdRp assay containing endogenous RNA templates. Template-dependent and species-specific RdRp activity could be detected after the removal of endogenous RNA templates. The 3' untranslated regions (UTR) containing a stretch of 40 adenylate residues were shown to be an efficient exogenous RNA template for in vitro RdRp reactions. Solution hybridization and nuclease digestion studies revealed that the products transcribed in vitro were minus-sense. Besides using the 3' UTR for minus-sense RNA synthesis, the BaMV RdRp can also recognize 3' terminal 77 nucleotides of the minus-strand for plus-sense RNA synthesis. Promoter studies with BaMV RdRp showed that domain D containing the potexviral hexamer motif of the 3' UTR would be the major contributor of minus-sense RNA synthesis in vitro. On the other hand, the pseudoknot domain containing the poly(A) sequences would be sufficient for minus-sense RNA synthesis.

Effect of pravastatin on myocardial protection during coronary angioplasty and the role of adenosine

Pravastatin has been shown, in an experimental model of ischemia reperfusion, to increase adenosine levels, which exert a potent and protective effect on the heart. The purpose of this study was to investigate whether pravastatin can provide cardioprotection by increased production of adenosine in patients undergoing coronary angioplasty, a clinical model of ischemia reperfusion. Thirty-five hyperlipidemic patients who underwent elective angioplasty for a major epicardial coronary artery were randomly allocated to either 3-month pravastatin or placebo before catheterization. In the placebo group, the mean ST-segment shift during the second balloon inflation was similar that observed during the first inflation, whereas in the preconditioned patients, the shift was significantly less, which is consistent with ischemic preconditioning. In the pravastatin-treated patients, the changes of ST-segment shift were similar between the first and second balloon inflations. In contrast, the patients who received aminophylline developed higher ST-segment shifts during the first and second inflations than those in the pravastatin-treated group alone. Measurements of chest pain score and myocardial lactate extraction ratios during inflation mirrored those of the ST-segment shift. The present study demonstrates that administration of pravastatin results in a significant gain in tolerance to ischemia during angioplasty. The effect of pravastatin was abolished by aminophylline, suggesting that the cardioprotective effect of pravastatin may result from activation of adenosine receptors.

Probing the importance of the amino-terminal sequence of the beta- and gamma-chains to the properties of normal adult and fetal hemoglobins

A recombinant mutant of human fetal hemoglobin (Hb F), named rHb Oscar, has been constructed to explore the importance of the sequence of the amino-terminal region of the gamma-chain to the structural and functional properties of Hb F as compared to human normal adult hemoglobin (Hb A). Substitutions in the N-terminal region of Hb A have shown this region to be important to its structural and functional properties. Recent studies of recombinant mutants of Hb A with gamma-chain mutations have been used to probe the significance of the N-terminal sequence to the properties of Hb F. One of these mutants of Hb A, called rHb Felix, contains eight substitutions in the N-terminal region of the beta-chain corresponding to the sequence of the gamma-chain in that region [Dumoulin et al. (1998) J. Biol. Chem. 273, 35032-35038]. rHb Felix exhibits a 2,3-bisphosphoglycerate (2,3-BPG) response like that of Hb A, but its tetramer-dimer dissociation constant is similar to that of Hb F. In contrast, rHb Oscar contains a gamma-chain with eight mutations at the N-terminal end corresponding to the sequence of the beta-chain of Hb A in that region. (1)H NMR studies of rHb Oscar indicate a global structure like that of Hb F. rHb Oscar is not as stable against alkaline denaturation as Hb F but is more stable than Hb A, and it exhibits a stronger response to 2,3-BPG and inositol hexaphosphate as compared to Hb F. The 2,3-BPG effect in rHb Oscar also appears to be slightly enhanced compared to that in Hb A. Subzero isoelectric focusing experiments suggest that rHb Oscar does not have dissociation properties like those of Hb A. These results along with those of rHb Felix illustrate that the effects of the N-terminal region on structure and function of the Hb molecule are complicated by interactions with the rest of the molecule that are not yet well defined. However, studies of complementary mutations of Hb A and Hb F may eventually help to define such interactions and lead to a better understanding of the relationship between the amino acid sequence and the properties of the Hb molecule.

The correlation between alteration of p16 gene and clinical status in oral squamous cell carcinoma

The purpose of the study was to evaluate the presence of alteration of the tumor suppressor gene p16 and to correlate these changes with the clinical status of the patients in oral squamous cell carcinoma. Forty-eight oral squamous cell carcinomas were included in the analyses. Deletion analysis was performed by the polymerase chain reaction (PCR). Mutation analysis was restricted to exon 1 and exon 2 of the p16 gene, previously shown to have a high incidence of mutations. The sequences containing exon 1 and exon 2 were amplified by PCR and screened with a single-strand conformation polymorphism (SSCP) technique. Samples showing band shifts in SSCP were sequenced by PCR direct sequencing. Western blots were used to detect the protein expression of the p16 gene, and the results were evaluated with regard to their biological relevance in correlation with clinicopathological factors. Seven (14.6%) deletions were found; 5 (10.4%) mutations were discovered and located in different codons; 26 (54%) specimens had no p16 protein expression; in 11 specimens with p16 deletion or mutation, p16 protein could not be detected. One mutation was non-sense. The p16 gene alterations showed no relationship with location and clinical stage of cancer; however, a close relationship between p16 alterations and cancer metastasis to neck lymph node was found. The alteration rate gradually elevated from well to poorly differentiated grades. We perceive two results. First, the alterations of the p16 gene are common in oral squamous cell carcinoma. Second, the alterations of the p16 gene may attribute to the metastatic behavior or histological grade of cancer cells.

Relation of polymorphism in the promotor region for the human osteocalcin gene to bone mineral density and occurrence of osteoporosis in postmenopausal Chinese women in Taiwan

Osteoporosis is a common disorder with a strong genetic component. Our aim was to evaluate the correlation of the HindIII osteocalcin gene polymorphism to bone mineral density (BMD) and their relationship to osteoporosis. We determined the HindIII osteocalcin gene polymorphism using polymerase chain reaction (PCR)-based restriction analysis in postmenopausal Chinese women in Taiwan. The osteocalcin gene polymorphism was detected by the restriction enzyme HindIII, where the H allele indicated the absence of the cuttable site and the h allele indicated its presence. We then related the genotypes to BMD and occurrence of osteoporosis in these women. The allelic frequencies for postmenopausal Chinese women in Taiwan were 64% for h and 36% for H in HindIII restriction fragment length polymorphisms. The prevalence of each genotype in the study population was 37.7% hh, 52.6% Hh, and 9.7% HH. The subjects with genotype hh had the greatest BMD at the lumbar spine and the femoral neck, and those with HH had the smallest BMD at the femoral neck, but these differences did not reach statistical significance. The HindIII osteocalcin genotype showed a significant effect on the prevalence of osteoporosis in the subjects at the femoral neck, that is, women with genotype HH had a 6.4 times greater risk for osteoporosis (P < 0.05), and those with genotype Hh had a 1.2 times greater risk than women with genotype hh. In conclusion, the HindIII osteocalcin gene polymorphism is associated with reduced BMD and predisposes women to osteoporosis at the femoral neck.

Molecular analysis of SMN, NAIP and P44 genes of SMA patients and their families

Mutations of the telomeric survival motor neuron gene (SMN1) are related to spinal muscular atrophy (SMA). However, no phenotype-genotype correlation has been observed since the SMN1 gene is lacking in the majority of patients affected with either the severe form (type I) or the milder forms (types II and III). Here, we analyze the SMN, NAIP and P44 genes in 132 Chinese SMA patients and their families. At least three types of normal allele, and four types of mutant allele were found in this study. The combination of one normal allele with one mutant allele resulted in carriers of different types, and the combination of different mutant alleles accounted for the different genotypes among different types of SMA. Deletions of mutant alleles can be further subgrouped into four types, which includes involving SMN1, SMN1 and NAIP(T) (telomeric portion of NAIP gene), SMN1 and NAIP(T) and P44(T) (telomeric portion of P44 gene), and SMN1 and SMN2 (centromeric portion of SMN gene). Some of the severe (type I) SMA cases correlated with the extent of deletions in the SMN, NAIP and P44 genes or the dosage of SMN gene when both SMN1 and SMN2 are deleted. We also found two novel point mutations, an A insertion at codon 8 (AGT-->AAGT) and an A substitution at codon 228 (TTA-->TAA).