What happens post-pilot testing? A model for revising a disability awareness and competency training program

Disability awareness and competency trainings are an important component of addressing ableism and health equity in the health promotion context. This commentary describes our process of developing, implementing, and refining a disability competency training, the Inclusive Community Exercise Training, for community-based group exercise instructors. The training originated from a partnership between academic researchers, community organizations, and individuals with disabilities. After initial pilot testing, we used feedback from participants to enhance the training. To optimize successful dissemination of this training, we utilized the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework, which is widely used in public health. The revision process focused on generalizing content to suit a wider audience, utilizing an eLearning platform for dissemination, and optimizing interactivity to improve learning effectiveness. The commentary emphasizes the lessons learned and the significance of systematic program revision, considering diverse expertise, content tailoring, and the benefits of accessible eLearning platforms.

A Rare Bird: Diagnosis of Psittacosis Meningitis by Clinical Metagenomic Next-Generation Sequencing

Psittacosis is a zoonotic infectious disease caused by the transmission of Chlamydia psittaci; it often presents as a pulmonary infection but rarely as disseminated disease. Because diagnoses of psittacosis are often underreported due to infrequent pathogen-specific testing, clinical metagenomic next-generation sequencing may be helpful to diagnose such an uncommon syndrome.

Establishment and cryptic transmission of Zika virus in Brazil and the Americas

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.

A hospital-wide screening programme to control an outbreak of vancomycin-resistant enterococci in a large tertiary hospital in Hong Kong

INTRODUCTION

Apart from individual small-scale outbreaks, infections with vancomycin-resistant enterococci are uncommon in Hong Kong. A major outbreak of vancomycin-resistant enterococci, however, occurred at a large tertiary hospital in 2013. We describe the successful control of this outbreak and share the lessons learned.

METHODS

In 2013, there was an abnormal increase in the incidence of vancomycin-resistant enterococci carriage compared with baseline in multiple clinical departments at Queen Elizabeth Hospital. A multipronged approach was adopted that included a 10-week hospital-wide active screening programme, which aimed to identify and isolate hidden vancomycin-resistant enterococci carriers among all in-patients. The identified carriers were completely segregated in designated wards where applicable. Other critical infection control measures included directly observed hand hygiene and environmental hygiene. A transparent and open disclosure approach was adopted throughout the outbreak.

RESULTS

The infection control measures were successfully implemented. The active screening of vancomycin-resistant enterococci was conducted between 30 September and 10 November 2013. A total of 7053 rectal swabs were collected from patients in 46 hospital wards from 11 departments. The overall carriage rate of vancomycin-resistant enterococci was 2.8% (201/7053). Pulsed-field gel electrophoresis showed a predominant outbreak clone. We curbed the outbreak and kept the colonisation of vancomycin-resistant enterococci among patients at a pre-upsurge low level.

CONCLUSIONS

We report the largest cohesive effort to control spread of vancomycin-resistant enterococci in Hong Kong. Coupled with other infection control measures, we successfully controlled vancomycin-resistant enterococci to the pre-outbreak level. We have demonstrated that the monumental tasks can be achieved with meticulous planning, and thorough communication and understanding between all stakeholders.

Novel mutation of RUNX2 gene in a patient with cleidocranial dysplasia

BACKGROUND

Cleidocranial dysplasia is a rare hereditary skeletal disorder due to heterozygous loss of function mutations in the RUNX2 gene that encodes runt-related transcription factor 2 (RUNX2). Here we report a 52 year-old woman with cleidocranial dysplasia due to a novel RUNX2 mutation.

CASE DESCRIPTION

A 52 year-old Han Chinese woman presented with short stature and skeletal dysplasia that was first noted during early childhood. She was 153 cm in height and 40 kg in weight. Her skull was deformed with hypertelorism, midface hypoplasia, protrusion of chin, and dental abnormalities. Radiological examination revealed shortened clavicles and depressed skull bone and that were consistent with the clinical diagnosis of cleidocranial dysplasia. There was no family history of a similar skeletal disorder. We sequenced the RUNX2 gene and discovered a novel heterozygous mutation in exon 3 (c.476 del G, p.G159fs175X) that is predicted to cause a frameshift and premature termination that leads to the loss of the final 347 amino acid residues. This severely truncated protein is expected to be inactive.

LITERATURE REVIEW

RUNX2 gene controls osteoblast differentiation and chondrocyte maturation. Around 90 RUNX2 mutations have been discovered in patients with cleidocranial dysplasia.

CLINICAL RELEVANCE

We identified a case of cleidocranial dysplasia due to a novel mutation of RUNX2 gene at exon 3 (c.476 del G).

Nutrient intake among US adults with disabilities

BACKGROUND

Physical, mental and financial barriers among persons with disabilities limit their access to healthier diet. The present study investigated the relationship between disabilities and nutrient intake among US adults.

METHODS

Data originated from National Health and Nutrition Examination Survey 2007-2008 and 2009-2010 waves (n = 11,811). Five disability categories include activities of daily living (ADLs), instrumental activities of daily living (IADLs), leisure and social activities (LSAs), lower extremity mobility (LEM) and general physical activities (GPAs). Nutrient intakes from food and dietary supplements were calculated from 24-h dietary recalls. Adherence to dietary reference intakes and dietary guideline recommendations was compared between people with and without disabilities and across disability categories in the statistical analysis.

RESULTS

GPAs, IADLs, LSAs, LEM and ADLs occupied 24.5%, 13.3%, 9.9%, 9.2% and 9.2% of US adults, respectively (not mutually exclusive). Only 42.3%, 11.3%, 63.8%, 47.7%, 48.7%, 9.7%, 48.7%, 90.7%, 21.7% and 4.7% of adults had saturated fat, fibre, cholesterol, vitamin A, vitamin C, vitamin D, calcium, iron, sodium and potassium intakes from food within recommended levels, respectively. Dietary supplement use moderately improved vitamin C, vitamin D and calcium intakes. People with disabilities were less likely to meet recommended levels on saturated fat, fibre (except GPAs), vitamin A (except GPAs), vitamin C (except GPAs), calcium and potassium intakes than persons without disability. Nutrient intake differed across disability categories, with ADLs least likely to meet recommended intakes.

CONCLUSIONS

Interventions targeting persons with disabilities through nutrition education and financial assistance are warranted to promote healthy diet and reduce disparities.

A novel mutation of KCNJ11 gene in a patient with permanent neonatal diabetes mellitus

A 4-month-old male baby was diagnosed with Permanent Neonatal Diabetes Mellitus. We identified a novel missense heterogeneous mutation in the KCNJ11 gene at codon 167 (aTC→tTC) in a region that corresponds to a predicted intracellular gate of the ATP-sensitive potassium channel.

A Novel mutation in the SLC26A4 gene in a Chinese family with Pendred syndrome

OBJECTIVE

To investigate the mutations in the SLC26A4 gene in a Chinese patient with Pendred syndrome.

METHODS

The diagnosis of Pendred syndrome was confirmed by the family history, pure tone audiogram, perchlorate discharge test (PDT), and computed tomography (CT) of the temporal bone. DNA extraction, PCR and DNA sequencing were performed according to standard procedures. Mutations in the SLC26A4 gene were compared with 100 unrelated subjects to exclude common polymorphism. Splice-site mutation was further confirmed by restriction enzyme length polymorphism (RFLP) with the specifically designed primers.

RESULTS

The proband presented with typical features of bilateral sensorineural deafness since childhood and goiter development in the early adulthood. Thyroid studies disclosed euthyroidism with elevated thyroglobulin, but negative for PDT. Marked enlargement of bilateral vestibular aqueduct (>1.5 mm) was found by CT of the temporal bone. A novel SLC26A4 splice-site mutation c.1263+1G>A (IVS10+1G>A) was identified in compound heterozygosity with the missense mutation c.1079C>T (p.A360V) in the proband. Both mutations were not found in the 100 unrelated Chinese.

CONCLUSIONS

Our results support previous findings that Pendred syndrome can be caused by compound heterozygous mutation in the SLC26A4 gene, in which IVS10+1G>A is a novel pathogenic mutation.

Three novel mutations in the PHEX gene in Chinese subjects with hypophosphatemic rickets extends genotypic variability

Mutations in the phosphate-regulating endopeptidase homolog, X-linked, gene (PHEX), which encodes a zinc-dependent endopeptidase that is involved in bone mineralization and renal phosphate reabsorption, cause the most common form of hypophosphatemic rickets, X-linked hypophosphatemic rickets (XLH). The distribution of PHEX mutations is extensive, but few mutations have been identified in Chinese with XLH. We extracted genomic DNA and total RNA from leukocytes obtained from nine unrelated Chinese subjects (three males and six females, age range 11-36 years) who were living in Taiwan. The PHEX gene was amplified from DNA by PCR, and the amplicons were directly sequenced. Expression studies were performed by reverse-transcription PCR of leukocyte RNA. Serum levels of FGF23 were significantly greater in the patients than in normal subjects (mean 69.4 ± 18.8 vs. 27.2 ± 8.4 pg/mL, P < 0.005), and eight of the nine patients had elevated levels of FGF23. Germline mutations in the PHEX gene were identified in five of 9 patients, including novel c.1843 delA, donor splice site mutations c.663+2delT and c.1899+2T>A, and two previously reported missense mutations, p.C733Y and p.G579R. These data extend the spectrum of mutations in the PHEX gene in Han Chinese and confirm variability for XLH in Taiwan.

Deoxyelephantopin, a novel multifunctional agent, suppresses mammary tumour growth and lung metastasis and doubles survival time in mice

BACKGROUND AND PURPOSE

Elephantopus scaber L. (Asteraceae) is a traditional herbal medicine with anti-cancer effects. We evaluated the in vitro and in vivo efficacy of a major sesquiterpene lactone constituent of E. scaber, deoxyelephantopin (DET), against mammary adenocarcinoma and the underlying molecular mechanism.

EXPERIMENTAL APPROACH

A variety of cellular assays, immunoblotting and immunohistochemistry, as well as both orthotopic and metastatic TS/A tumour models in BALB/c mice, were used. Test mice were pretreated and post-treated with DET or paclitaxel and mammary tumour growth evaluated.

KEY RESULTS

DET (< or =2 microg x mL(-1)) significantly inhibited colony formation, cell proliferation, migration and invasion of TS/A cells and induced G(2)/M arrest and apoptosis in TS/A cells. c-Jun N-terminal kinase-mediated p21(Waf1/Cip1) expression and caspase activation cascades were up-regulated by DET, effects suppressed by N-acetyl-L-cysteine. Moreover, tumour necrosis factor alpha-induced matrix metalloproteinase-9 enzyme activity and expression and nuclear factor-kappa B activation were abolished by DET. Pretreatment with DET was more effective than paclitaxel, for profound suppression of orthotopic tumour growth (99% vs. 68% reduction in tumour size) and lung metastasis of TS/A cells (82% vs. 63% reduction in metastatic pulmonary foci) and prolonged median survival time (56 vs. 37 days, P < 0.01) in mice. The levels of cyclooxygenase-2 and vascular endothelial growth factor in metastatic lung tissues of TS/A-bearing mice were attenuated by DET.

CONCLUSIONS AND IMPLICATIONS

Our data provide evidence for the suppression of mammary adenocarcinoma by DET with several mechanisms and suggest that DET has potential as a chemopreventive agent for breast cancer.

Analysis of the RET gene in subjects with sporadic Hirschsprung's disease

BACKGROUND

Hirschsprung's disease (HSCR), or aganglionic megacolon, is a hereditable disease of the enteric nervous system. It is an embryonic developmental disorder characterized by the absence of ganglion cells in the lower enteric plexus. Gut motility is compromised in HSCR, with consequent risk of intestinal obstruction.

METHODS

We sequenced the RET gene and characterized the clinical manifestations in 15 unrelated Chinese patients (9 males, 6 females; age range, 2-21 years) with sporadic HSCR. Genomic DNA extraction, PCR and DNA sequence analysis were performed according to standard procedures.

RESULTS

We identified heterozygous RET gene mutations in 2 patients. The mutations included a missense mutation in exon 2 (CGC --> CAC) resulting in a substitution of arginine by histidine at codon 67 (patient 1), and a missense mutation in exon 3 (TAC --> AAC) resulting in a substitution of tyrosine by asparagine at codon 146 (patient 2). The pathological findings disclosed short-segment HSCR in patient 1 and long-segment HSCR in patient 2, respectively.

CONCLUSION

We identified RET gene mutations in 2 of 15 patients with HSCR in Taiwan. The Y146N mutation we identified was novel.

Hepatoprotective phytocompounds from Cryptomeria japonica are potent modulators of inflammatory mediators

Cryptomeria japonica is an important plantation conifer tree in Asia. This study aimed to characterize the anti-inflammatory and hepatoprotective activities of the phytocompounds from C. japonica wood on LPS- or TPA-induced activation of proinflammatory mediators and CCl(4)-induced acute liver injury in mice. A CJH7-2 fraction was purified from C. japonica extracts following bioactivity-guided fractionation, and it exhibited significant activities on inhibition of NO production and iNOS expression as well as up-regulating HO-1 expression in LPS-stimulated macrophages. CJH7-2 also potently inhibits COX-2 enzymatic activity (IC(50)=5 microg/mL) and TPA-induced COX-2 protein expression in mouse skin (1mg/200 microL/site). CJH7-2 (10 mg/kg BW) can prevent CCl(4)-induced liver injury and aminotransferases activities in mice. Chemical fingerprinting analysis showed that terpenes are the major bioactive compounds in the CJH7-2 fraction. This is the first study to demonstrate that chemical constituents from the wood extract of C. japonica possess anti-inflammatory activities in vitro and in vivo that may play a role in hepatoprotection.

Diterpenes from Cryptomeria japonica inhibit androgen receptor transcriptional activity in prostate cancer cells

We identified eight diterpenes from Cryptomeria japonica (Taxodiaceae), which inhibit the activity of the androgen receptor (AR) in human prostate cancer (PCa) 22Rv1-derived 103E cells. The compounds 6,12-dihydroxyabieta-5,8,11,13-tetraen-7-one ( 2), sugiol ( 3), ferruginol ( 4), and 5-epixanthoperol ( 7) have near 100 % AR inhibition efficacy at concentrations of 10, 5, 25, and 25 microM, respectively. Because these compounds have very similar structures, analysis of their differential activity may aid in the design of inhibitors for PCa treatment.

Analysis of the SLC26A4 gene in patients with Pendred syndrome in Taiwan

Pendred syndrome (PS) is an autosomal recessive disease that is characterized by congenital sensorineural hearing loss, goiter, and a partial iodine organification defect. In this study, we characterized the thyroid status and identified mutations in the SLC26A4 gene in Chinese subjects with PS. We evaluated 7 unrelated Chinese subjects who had PS. Biochemical analysis, formal audiogram, ultrasonography of the thyroid gland, perchlorate discharge test, computerized tomography scan of the vestibular aqueducts, and DNA sequence analysis of SLC26A4 were performed. Levels of thyroid hormones were essentially normal in all patients: 2 patients had goiters and/or elevated serum thyroglobulin levels, whereas 2 other patients had positive thyroid antibodies and a positive perchlorate discharge test. We identified SLC26A4 gene mutations in 6 of 7 probands and their affected relatives. The affected subjects in family I was compound heterozygous for 2 missense mutations: a mutation in exon 9 (1079C>T) that resulted in the replacement of alanine by valine at codon 360 (A360V) and a mutation in exon 19 (2168A>G) that resulted in the replacement of histidine by arginine at codon 723 (H723R). The affected subjects in families II and III all were homozygous for a mutation in intron 7. The probands IV and V were compound heterozygotes for the mutation in intron 7 and in exon 19, and the proband VI was compound heterozygous for the intron 7 mutation and a missense mutation in exon 12 (1343C>T) that resulted in the replacement of serine by leucine at codon 448 (S448L). One novel mutation was identified (A360V). We identified biallelic mutations in the SLC26A4 gene in 6 of 7 probands with PS in Taiwan, including a novel missense mutation. The mild thyroid dysfunction in these patients suggests that PS should be considered in all patients with congenital or early-onset hearing impairment.

A potential dating technique using 228Th/228Ra ratio for tracing the chronosequence of elemental concentrations in plants

We propose a radiometric method based on measurement of the radioactivity of the naturally occurring radionuclides (228)Ra and 228)Th and the derived (228)Th/(228)Ra ratios in plant samples to estimate plant age and the corresponding nutritional conditions in a field-growing fern, Dicranopteris linearis. Plant age (tissue age) was associated with the (228)Th/(228)Ra ratio in fronds, which implies the accumulation time of immobile elements in the plant tissue or the life span of the fronds. Results indicated that the accumulation of alkaline earth elements in D. linearis is relatively constant with increased age, while the K concentration is reversed with age because of translocation among plant tissues. Estimation of dating uncertainty based on measurement conditions revealed that the radiometric technique can be applied to trace chronosequential changes of elemental concentrations and environmental pollutants in plants with ages of less than 10-15 years.

A compound heterozygous mutation in the CYP17 (17alpha-hydroxylase/17,20-lyase) gene in a Chinese subject with congenital adrenal hyperplasia

Mutations in the CYP17 gene impair steroid biosynthesis in the adrenals and gonads, resulting in 17alpha-hydroxylase/17,20-lyase (P450c17) deficiency, leading to amenorrhea, sexual infantilism, hypokalemia, and hypertension. To date, more than 50 mutations in the CYP17 gene associated with congenital adrenal hyperplasia have been described. In this study, we analyzed a 36-year-old phenotypic female, genotypic male, with P450c17 deficiency to compare with an additional group of 50 Chinese subjects without P450c17 deficiency in Taiwan. DNA sequence analysis of the CYP17 gene was performed. The result showed that the proband had a compound heterozygous mutations in exon 6 (CGC-->TGC) that resulted in the substitution of arginine by cysteine at codon 362, and in exon 7 (CCG-->CGG) that resulted in the substitution of proline by arginine at codon 409. In conclusion, we have identified a compound heterozygous mutation in the CYP17 gene in one patient with congenital adrenal hyperplasia in Taiwan.

Two novel mutations in the MEN1 gene in subjects with multiple endocrine neoplasia-1

Multiple endocrine neoplasia type 1 (MEN1) is characterized by parathyroid, enteropancreatic endocrine and pituitary adenomas as well as germline mutation of the MEN1 gene. We describe 2 families with MEN1 with novel mutations in the MEN1 gene. One family was of Turkish origin, and the index patient had primary hyperparathyroidism (PHPT) plus a prolactinoma; three relatives had PHPT only. The index patient in the second family was a 46-yr-old woman of Chinese origin living in Taiwan. This patient presented with a complaint of epigastric pain and watery diarrhea over the past 3 months, and had undergone subtotal parathyroidectomy and enucleation of pancreatic islet cell tumor about 10 yr before. There was also a prolactinoma. Sequence analysis of the MEN1 gene from leukocyte genomic DNA revealed heterozygous mutations in both probands. The Turkish patient and her affected relatives all had a heterozygous A to G transition at codon 557 (AAG-->GAG) of exon 10 of MEN1 that results in a replacement of lysine by glutamic acid. The Chinese index patient and one of her siblings had a heterozygous mutation at codon 418 of exon 9 (GAC-->TAT) that results in a substitution of aspartic acid by tyrosine. In conclusion, we have identified 2 novel missense mutations in the MEN1 gene.

Measurement of 224Ra uptake in a fern actively accumulating radium

A method is proposed for determining the level of 224Ra in plant samples by measuring its descendant nuclide 212Pb at 239 keV by gamma-ray spectrometry. Variations of 224Ra and 212Pb over time during sample preparation and counting were delineated prior to gamma-ray measurement. The 224Ra concentrations in plant samples were measured by their direct uptake from soil, which could be determined and distinguished from that resulting from decay of 228Th inside the plants. We propose that a field-growing Dicranopteris linearis, which actively accumulates radium, can be used as an indicator of the nutritional transportation and metabolic rate of radium and other alkaline earth elements. We investigated the influence of rainfall on 224Ra concentrations in fronds of D. linearis and the corresponding uptake rates. 224Ra could serve as a natural tracer of growth in plants over a several days. Its presence and content in plants implies a temporal mineral metabolic rate, which can provide useful information for plant physiological and environmental investigations.

Mutations in low-density lipoprotein receptor gene as a cause of hypercholesterolemia in Taiwan

Familial hypercholesterolemia (FH) is inherited as an autosomal dominant trait that has been associated with more than 920 different mutations in the low-density lipoprotein receptor (LDLR) gene. To characterize LDLR gene mutations in the Chinese of Han descent with FH, we isolated genomic DNA from peripheral blood samples of 20 affected subjects and 50 healthy subjects with no family history of hypercholesterolemia. We used polymerase chain reaction and long polymerase chain reaction to amplify the 18 coding exons and the minimal promoter of the LDLR gene, and subjected amplicons to direct sequence analysis. We identified 6 mutations in LDLR gene, including heterozygous missense mutations I420T (ATC-->ACC), C660W (TGC-->TGG), H562Y (CAC-->TAC), and A606T (GCC-->ACC), and a heterozygous and a homozygous mutation in codon P664L (CCG-->CTG) as well as a homozygous large deletion of exons 6 to 8. The FH homozygotes manifested generalized xanthomatosis. One of the mutations we identified (C660W) was novel. In conclusion, we identified 5 missense mutations and 1 large deletion in LDLR gene, including 1 novel mutation in Han Chinese with FH in Taiwan.

Novel mutations in the MEN1 gene in subjects with multiple endocrine neoplasia-1

OBJECTIVE

To identify MEN1 gene mutations and characterize clinical manifestations in Chinese kindred with multiple endocrine neoplasia type 1 (MEN1) in Taiwan.

PATIENTS AND METHODS

Eight unrelated subjects (one male and seven females, age range 26-70 years) with clinical manifestations of MEN1 were analysed. In addition, 45 relatives that included 10 affected (three males and seven females, age range 32-53 years) and 35 unaffected (17 males and 18 females, age range 15-80 years) subjects were evaluated. Genomic DNA extraction, polymerase chain reaction (PCR) and DNA sequence analysis were performed according to standard procedures.

RESULTS

We identified heterozygous MEN1 gene mutations in all eight probands and 10 affected subjects as well as in 13 clinically asymptomatic relatives. Novel mutations included a missense mutation in a heterozygous mutation in exon 9 (GAC --> CAC) resulting in a substitution of aspartic acid by histidine at codon 418 (family 1); a nonsense mutation at codon 556 of exon 10 (GAG --> TAG) resulting in a stop codon and termination (family 2); a missense mutation in exon 2 (GGG --> GAG) causing the substitution of glycine by glutamic acid at codon 110 (family 3); and a deletion/insertion mutation in nucleotide 1200 of exon 8 resulting in frameshift and early termination (family 4). Affected subjects in families 5-7 shared the same C insertion at nucleotide 1650 of exon 10, similar to that previously described as a hotspot for mutation, and proband 8 had a previously described mutation in intron 4 of the MEN1 gene (IVS4-9 G --> A). We also found that 18 (58%) of our 31 MEN1 mutant carriers had clinical symptoms, whereas four (13%) had biochemical abnormalities without clinical symptoms, and nine (29%) were unaffected both clinically and biochemically.

CONCLUSIONS

We have identified four novel mutations in the MEN1 gene in patients with MEN1 in Taiwan.

Constituents of Leaves of Phellodendron japonicum MAXIM. and Their Antioxidant Activity

Three new flavonoid derivatives, 6'''-O-acetyl amurensin (1), 6'''-O-acetyl phellamurin (3) and (2R)-phellodensin-F (5), together with thirty known compounds have been isolated from the leaves of Phellodendron japonicum MAXIM. Their structures were established by means of spectroscopic analysis, including extensive 2D NMR and Mass spectra. The known compounds were identified by comparison with published physical and spectral data. The isolated compounds were screened for their in vitro antioxidant activity through DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging assay. Compounds quercetin and phellodenin-A demonstrated significant radical scavenging activity.

Decomposition of 2-mercaptothiazoline in aqueous solution by ozonation

This study investigates the ozonation of 2-mercaptothiazoline (2-MT). The 2-MT is one of the important organic additives for the electroplating solution of the printed wiring board industry and has been widely used as a corrosion inhibitor in many industrial processes. It is of concern for the aquatic pollution control especially in the wastewaters. Semibatch ozonation experiments in the completely stirred tank reactor are performed under various concentrations of input ozone. The concentrations of 2-MT, sulfate, and ammonium are analyzed at specified time intervals to elucidate the decomposition of 2-MT during the ozonation. In addition, the time variation of the dissolved ozone concentration (C(ALb)) is continuously monitored in the course of experiments. Total organic carbon (TOC) is chosen and measured as a mineralization index of the ozonation of 2-MT. The results indicate that the decomposition of 2-MT is efficient, while the mineralization of TOC is limited via the ozonation only. Simultaneously, the yield of sulfate with the maximum value of about 47% is characterized by the increases of TOC removal and ozone consumption. These results can provide some useful information for assessing the feasibility of the treatment of 2-MT in the aqueous solution by the ozonation.

Mutations in the lipoprotein lipase gene as a cause of hypertriglyceridemia and pancreatitis in Taiwan

INTRODUCTION

Familial lipoprotein lipase (LPL) deficiency is inherited as an autosomal recessive trait and is characterized by chylomicronemia, eruptive xanthoma, hepatosplenomegaly, and recurrent pancreatitis.

AIMS AND METHODOLOGY

Two unrelated Chinese of Han descent with hypertriglyceridemia were enrolled in this study, and another six Han Chinese with no family history of hypertriglyceridemia and diabetes were recruited as normal controls. LPL activity was determined with use of an artificial substrate of 14C-trioleine and Arabic gum, and release of 14C free fatty acid was determined by the liquid-liquid partitioning system. LPL mass was measured by enzyme immunoassay. Genomic DNA was extracted from EDTA-preserved whole blood, and PCR was used to amplify the nine coding exons and the minimal promoter of the LPL gene.

RESULTS

DNA sequence analysis revealed that mutations were identified in both patients; one patient had compound heterozygous mutations in codon 252 [CTG(Leu) --> GTG(Val)] and in codon 264 [TGC(Cys) --> TGa(Ter)] of exon 6, and the other patient had homozygous L252V mutation. These subjects had > or =90% reduction in LPL mass and > or =60% reduction in LPL activity.

CONCLUSION

The mutated and truncated LPLs caused hypertriglyceridemia in these patients in Taiwan with hypertriglyceridemia and pancreatitis.

Dynamic behavior of ozonation with pollutant in a countercurrent bubble column with oxygen mass transfer

The dynamic behavior of ozonation with pollutants in a countercurrent bubble column is studied for the model establishment. Bubble columns have been widely used for an ozonation system in the plants and laboratories. In addition, a countercurrent bubble column has been commonly recommended than a cocurrent one because it has a higher ozone transfer efficiency. Therefore, the investigation of this paper focuses on the countercurrent bubble column. As an ozonation process starts, the gas mixture of ozone and oxygen is introduced into the bottom of a column, and then transferred into the liquid. The pollutants in the wastewater are eliminated subsequently via oxidation by the dissolved ozone. There certainly exists a temporary and unsteady period before the ozonation system reaches steady state. However, available ozonation models employed to describe ozone and pollutant profiles have commonly been developed for steady state. The treating qualities of wastewater in the early stage of ozonation are usually not predicted, and the time required for the steady-state establishment remains to be determined. Moreover, oxygen mass transfer is usually neglected in previous ozonation models so that the increase of dissolved oxygen is uncertain. These information is desirable for the proper design and operation of ozonation system in a bubble column. Thus, the aim of this study is to model and investigate the dynamic processes of ozonation with pollutants including oxygen mass transfer. The dynamic axial dispersion model proposed is employed to predict the variation of the ozone, pollutant, and oxygen concentrations profiles. The validity of the model was demonstrated by comparing the predicted results with the experimental data. The o-cresol was chosen as the model pollutant. The temporal concentration variations of the residual o-cresol and dissolved oxygen in the effluent liquid, and the off-gas ozone in the free volume were measured accordingly. Furthermore, the variation of the enhancement factor of ozone and the amount of off-gas were predicted. Note that it usually needs 2-5 hydraulic retention times to approach steady state under the conditions of this study. Further, the effects of dimensionless system parameters on the performance of the ozonation processes are examined. As a result, the proposed dynamic model of ozonation with pollutants is useful for proper prediction of the variables of an ozonation system in a countercurrent bubble column.

Two novel mutations in the gene encoding thyroxine-binding globulin (TBG) as a cause of complete TBG deficiency in Taiwan

OBJECTIVE

Thyroxine-binding globulin (TBG) encoded by the TBG gene on chromosome Xq22 is the major transport protein, carrying approximately 75% of circulating T4. Inherited defects in TBG are associated with three phenotypes based on the level of TBG in serum of affected hemizygous males: complete TBG deficiency (TBG-CD), partial TBG deficiency (TBG-PD) and TBG excess (TBG-E). In this study, we report two unrelated Han Chinese males with complete TBG deficiency who carry different mutations in the TBG gene.

PATIENTS

Two index cases of Han males who were diagnosed as having TBG deficiency on the basis of undetectable serum TBG and an additional 75 (50 males and 25 females) normal Han Chinese.

MEASUREMENT

Serum thyroid hormones were measured by chemiluminescent immunoassay, thyroid autoantibodies by an agglutination test, and TSH receptor antibody and TBG by radioimmunoassay. Genomic DNA extraction, polymerase chain reaction (PCR) and DNA sequence analysis of the TBG gene were performed with standard methods.

RESULTS

One index case had one missense mutation in his copy of the gene, a G --> A transition in codon 52 that results in the replacement of serine by asparagine, and a known polymorphism in codon 283 (TTG --> TTt) that results in the replacement of leucine by phenylalanine. The allelic frequency of TBG-Poly allele in 75 normal Han Chinese (100 chromosomes) was 31%. A second index case was hemizygous for a nonsense mutation in codon 280 of exon 3 (TGG --> TGa). This mutation, located in the C-terminal of TBG, predicts a markedly truncated protein.

CONCLUSIONS

This is the first report of complete thyroxine-binding globulin deficiency (TBG-CDT1 and TBG-CDT2) due to TBG gene mutations in Taiwan.

Decomposition of 2-naphthalenesulfonate in aqueous solution by ozonation with UV radiation

This study investigates the ozonation of 2-naphthalenesulfonate (2-NS) combined with ultraviolet (UV) radiation. Naphthalenesulfonic acids are of importance as dye intermediates for the dye and textile auxiliary industries. Its derivatives, such as 2-NS, have been found in rivers and tannery effluents causing pollution problems. Thus, the 2-NS is of concern for the aquatic pollution control especially in the surface and waste waters. Ozonation combined with UV radiation is employed for the removal of 2-NS in the aqueous solution. Semibatch ozonation experiments were proceeded under different reaction conditions to study the effects of ozone dosage and UV radiation on the oxidation of 2-NS. The concentrations of 2-NS and sulfate are analyzed at specified time intervals to elucidate the decomposition of 2-NS. In addition, values of pH and oxidation reduction potential are continuously measured in the course of experiments. Total organic carbon is chosen as a mineralization index of the ozonation of 2-NS. The mineralization of 2-NS via the ozonation is remarkably enhanced by the UV radiation. These results can provide useful information for the proper removal of 2-NS in the aqueous solution by the ozonation with UV radiation.

Combination gemcitabine and cisplatin chemotherapy for metastatic or recurrent nasopharyngeal carcinoma: report of a phase II study

BACKGROUND

To evaluate the efficacy and toxicity of combination gemcitabine plus cisplatin (GC) chemotherapy in metastatic or recurrent nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS

Forty-four patients of Chinese ethnicity with metastatic or recurrent NPC received ambulatory GC chemotherapy every 28 days (gemcitabine 1000 mg/m(2) days 1, 8 and 15; cisplatin 50 mg/m(2) days 1 and 8). There were 40 male and four female patients with a mean age of 47.4 years. More than half (54.5%) of the patients had received either prior platinum-based chemotherapy and/or radiotherapy to target lesions.

RESULTS

There were nine complete responses and 23 partial responses in the 44 patients, achieving an overall response rate of 73% (78% for the 41 assessable patients). The mean duration of response was 5.3 months. Improved subjective symptom-control scores were found in 78% of patients with pre-existing symptoms, while 64% of patients experienced improved general well-being scores. Toxicity was mainly hematological: grade III/IV anemia, granulocytopenia and thrombocytopenia were found in 11, 37 and 16% of cycles, respectively. With a median follow-up of 17.2 months, 62% survived 1 year while 36% were alive and progression free.

CONCLUSIONS

Gemcitabine plus cisplatin chemotherapy offers a satisfactory overall response rate, subjective patient improvement and safety profile for metastatic and recurrent NPC.

A novel mutation in the intron 1 splice donor site of the cholesterol ester transfer protein (CETP) gene as a cause of hyperalphalipoproteinemia

The exchange of cholesterol ester (CE) between lipoproteins occurs through the action of cholesterol ester transfer protein (CETP). The human CETP gene is composed of 16 exons encompassing 25 kbp on chromosome 16q13. The objective of this study was to determine whether a mutation in the CETP gene accounted for severe hyperalphalipoproteinemia in an 80-year-old subject. As a secondary objective, we also investigated the allelic frequency of D442G and Int14A mutation in 224 random Han Chinese subjects. DNA sequence analysis of the CETP gene in the patient revealed a peculiar nucleotide pattern in intron 1. To determine whether this peculiarity results in abnormally spliced mRNA, we used reverse-transcriptase polymerase chain reaction (RT-PCR) to amplify and sequence the patient's cDNA using CETP-specific primers that spanned this splice junction. Both the wild-type and mutant cDNA were detected, and the mutant cDNA showed that its 5'-splice site shifted 4 nucleotides upstream. This change results in a frame-shift and premature termination at amino acid residue 22, and thus predicts a markedly truncated protein product. Although this patient did not have either the D442G or Int14A allele, we found that the allelic frequency of D442G in 224 subjects was 4.46%. No subjects had the Int14A allele. In conclusion, a novel intron 1 splice site mutation in the CETP gene in 1 patient with hyperalphalipoproteinemia and D442G allelic frequency of 4.46% was found among a normal population in Taiwan.

Discriminative facility and its role in the perceived quality of interactional experiences

Discriminative facility refers to an individual's sensitivity to subtle cues about the psychological meaning of a situation. This research aimed at examining (a) the conceptual distinctiveness of discriminative facility, (b) the situation-appropriate aspect of this construct, and (c) the relationship between discriminative facility and interpersonal experiences. Discriminative facility was assessed by a new measure of situation-appropriate behaviors across a variety of novel stressful situations. Results from study 1 showed that discriminative facility had weak positive relationships with cognitive complexity and nonsignificant relationships with self-monitoring and social desirability, indicating that discriminative facility is a unique construct. Results from Study 2 revealed that higher levels of discriminative facility were associated with higher levels of perceived social support and a greater number of pleasant interpersonal events experienced, thus providing support for the theoretical proposition that discriminative facility is an aspect of social intelligence.

Prospective, randomized, placebo-controlled evaluation of the safety and immunogenicity of three lots of intranasal trivalent influenza vaccine among young children

BACKGROUND

Trivalent formulations of an experimental, cold-adapted, intranasal influenza (CAIV) vaccine have been shown to be safe, immunogenic and efficacious in young children.

METHODS

We evaluated the safety and immunogenicity of three consistency lots of CAIV in children 12 to 36 months of age randomized to one of five groups: Groups 1, 2 and 3 received separate lots containing A/Shenzhen/227/95 (H1N1), A/Wuhan/359/95(H3N2) and B/Harbin/7/94-like viral strains. Group 4 received an earlier efficacy trial lot which included a different H1N1 strain (A/Texas/36/91-like); and Group 5 received placebo. We performed strain-specific serum hemagglutination inhibition antibody levels against type A (H3N2 or H1N1) or type B as appropriate.

RESULTS

Overall 474 children received 2 doses, 2 months apart. Each lot was well-tolerated, and there were no significant group differences between consistency lots in the proportion of children with fever and local or systemic reactions after vaccination. The 3 consistency lots were not statistically different with regard to immunogenicity as measured by seroconversion or absolute geometric mean titer. Immune responses were more robust among initially seronegative children and for H3N2 and B strains than for H1N1 strains. After 2 doses of vaccine 97, 84 and 62% had hemagglutination inhibition titers > or = 1/32 against A/H3N2, B and H1N1 strains, respectively. For A/H3N2 only, immune responses after 1 dose of vaccine are similar to those seen after 2 doses.

CONCLUSIONS

Each consistency lot of CAIV is as or more immunogenic than a lot used in a large efficacy trial.

Staffing exercise sessions in pulmonary rehabilitation

INTRODUCTION

There is no published standard for the ratio of staff to patients during exercise sessions in outpatient pulmonary rehabilitation. This lack of a standard raises concern about patient safety and the ability to monitor patients adequately.

OBJECTIVE

Determine a staff-to-patient ratio standard by examining current practice.

METHODS

The directors of the 46 outpatient pulmonary rehabilitation programs in Ohio were surveyed. Directors of 40 (87%) programs responded, and the responses from the 36 programs that conducted pulmonary exercise sessions separately from cardiac sessions were analyzed.

RESULTS

The maximum number of staff in an exercise session was 2, with a median of 1. The maximum number of patients in a session was 20, with median of 4. Directors were also asked to rank the importance of 8 factors in determining the reported ratio. From highest to lowest importance, the factors were patient safety, severity of pulmonary disease, availability of space or equipment, entry test data, pulmonary diagnosis, presence of cardiac problems, convenience, and other. Sixty percent of programs restricted the number of patients per session based on staff-to-patient ratio.

CONCLUSIONS

Statewide practice for staff-to-patient ratio in Ohio was described. The most common staff-to-patient ratio during exercise sessions was 1:4 or less (78%). Exercise staff work with small groups in order to assure patient safety, to deal with patients' health problems, and to provide adequate facilities. A majority of programs restrict the number of patients per session so as to enforce the reported ratio.

The association of heterotrimeric GTP-binding protein (Go) with microtubules

The heterotrimeric GTP-binding regulatory proteins (G proteins) play an important role in the regulation of membrane signal transduction. Recently, we identified the association of Go protein with mitotic spindles. Here we have investigated the relationship between Go protein and microtubules. We used temperature-dependent reversible assembly and taxol methods to purify microtubules from bovine brains. Goalpha and Gbeta proteins were identified in the microtubular fraction by both methods. The Goalpha subunit in the microtubular fraction could be ADP ribosylated by pertussis toxin. Co-immunoprecipitation data also revealed that Go protein can interact with microtubules. Exogenous Go protein could be incorporated into the assembled microtubular fraction, and 5 microg/ml (60 nM) of Go protein inhibited 40% of microtubule assembly. Western blot analysis of Goalpha-1 and Goalpha-2 in microtubular fractions showed that only Goalpha-1 is associated with microtubules. We conclude that the Goalpha-1betagamma proteins are associated with microtubules and may play some role in regulating the assembly and disassembly of microtubules.

G protein beta2 subunit antisense oligonucleotides inhibit cell proliferation and disorganize microtubule and mitotic spindle organization

The association of G protein beta2 subunit (Gbeta2) with mitotic spindles in various mammalian cells has been demonstrated previously. Recently, we have identified the association of Gbeta2 protein with microtubules (Wu et al., [1998] J. Cell. Biochem. 70: 552-562). In the present experiment we have demonstrated the possible functional role of Gbeta2 in microtubule and mitotic spindle organization in mammalian cells. When Gbeta2 antisense phosphorothioate oligonucleotides were transfected into mammalian cells, inhibition of cell proliferation with cell death after a 4-day treatment was observed. If the transfected cells were incubated for two days and their Gbeta2 and microtubules were examined by Western blotting and immunofluorescence localization, marked reduction of the Gbeta2 protein, fragmentation and disassembly of cytoplasmic microtubules, and disorganized mitotic spindles were found. We conclude that the Gbeta2 protein is closely associated with microtubule assembly and may play a potential role in the regulation of cell proliferation and microtubule and mitotic spindle organization in mammalian cells.

Structural analysis of a fiber-pseudotyped adenovirus with ocular tropism suggests differential modes of cell receptor interactions

Adenovirus (Ad) entry into cells is initiated by the binding of the fiber knob to a cell surface receptor. The coxsackie- and adenovirus receptor (CAR) functions as the attachment receptor for many, but not all, Ad serotypes. Ad type 37 (Ad37), a subgroup D virus that causes keratoconjunctivitis in humans, does not infect cells via CAR despite demonstrated binding of the Ad37 knob to CAR. We have pseudotyped a fiber deletion Ad5 vector with the Ad37 fiber (Ad37f), and this vector retains the ocular tropism of Ad37. Here we present a cryo-electron microscopy reconstruction of Ad37f that shows the entire Ad37 fiber, including the shaft and knob domains. We have previously proposed that Ad37 may not utilize CAR for cell entry because of the geometric constraints imposed by a rigid fiber (E. Wu, J. Fernandez, S. K. Fleck, D. Von Seggern, S. Huang, and G. R. Nemerow, Virology 279:78-89, 2001). Consistent with this hypothesis, our structural results show that the Ad37 fiber is straight and rigid. Modeling of the interaction between Ad37f and host cell receptors indicates that fiber flexibility or rigidity, as well as length, can affect receptor usage and cellular tropism.

Uterine artery embolisation for treatment of fibroids: experience in Chinese women

Twelve women with symptomatic fibroids were treated with transcatheter uterine artery embolisation with the use of polyvinyl alcohol (PVA) particles. For the nine women who were due for follow-up, reduction in uterine volume and dominant fibroid size were observed on magnetic resonance imaging. All the nine women had normal luteinising hormone (LH) and follicle stimulating hormone (FSH) levels before the procedure and during the follow-up. Seven of the nine women reported noticeable symptomatic improvement during the follow-up. Pain experienced was of variable level, but well controlled. Adequate analgesia is essential for the procedure. Longer follow-up and prospective fertility studies are required to evaluate the long-term effects before this procedure could be safely extended to younger age groups.

Paradoxical vocal cord adduction mimicking as acute asthma in a pediatric patient

We report an adolescent girl with paradoxical vocal cord adduction who presented with acute onset of hyperventilation, wheezing and stridor that did not respond to bronchodilator and anti-inflammation therapy. The paradoxical vocal cord motion was confirmed by flexible fiberoptic bronchoscopic examination. We found the stridor was induced by hyperventilation, and was caused by paradoxical vocal cord movement. The abnormal cord motion may be psychogenic and could be misdiagnosed as asthma. It is important to investigate the underlying background and social history and to avoid unnecessary use of beta-agonists, steroids, and even endotracheal intubation or tracheostomy.

Specificity of auditory implicit and explicit memory: is perceptual priming for environmental sounds exemplar specific?

Previous research (Stuart & Jones, 1995) has suggested that identification of environmental sounds may be mediated by abstract sound recognition units. This article reports the results of four repetition priming experiments that find evidence to the contrary. Participants attempted to identify environmental sounds from the initial sound stems (Experiments 1 and 2) or when the sounds were embedded in white noise (Experiments 3 and 4). Repetition of an identical exemplar sound led to more priming than did exposure to a different exemplar, provided that the perceptual difference between the two different exemplars was sufficiently large. Such an exemplar specificity effect was independent of the depth of prior encoding. A similar exemplar specificity effect was also found in explicit stem-cued recall (Experiments 1 and 2) and recognition (Experiment 3). Depth of encoding dissociated performance on tests of repetition priming and explicit memory. These results suggest that a significant amount of specific information is remembered, both implicitly and explicitly, to characterize individual exemplars of a sound category.

Multicultural minds. A dynamic constructivist approach to culture and cognition

The authors present a new approach to culture and cognition, which focuses on the dynamics through which specific pieces of cultural knowledge (implicit theories) become operative in guiding the construction of meaning from a stimulus. Whether a construct comes to the fore in a perceiver's mind depends on the extent to which the construct is highly accessible (because of recent exposure). In a series of cognitive priming experiments, the authors simulated the experience of bicultural individuals (people who have internalized two cultures) of switching between different cultural frames in response to culturally laden symbols. The authors discuss how this dynamic, constructivist approach illuminates (a) when cultural constructs are potent drivers of behavior and (b) how bicultural individuals may control the cognitive effects of culture.

Multicultural minds. A dynamic constructivist approach to culture and cognition

The authors present a new approach to culture and cognition, which focuses on the dynamics through which specific pieces of cultural knowledge (implicit theories) become operative in guiding the construction of meaning from a stimulus. Whether a construct comes to the fore in a perceiver's mind depends on the extent to which the construct is highly accessible (because of recent exposure). In a series of cognitive priming experiments, the authors simulated the experience of bicultural individuals (people who have internalized two cultures) of switching between different cultural frames in response to culturally laden symbols. The authors discuss how this dynamic, constructivist approach illuminates (a) when cultural constructs are potent drivers of behavior and (b) how bicultural individuals may control the cognitive effects of culture.

Digitally collected cryo-electron micrographs for single particle reconstruction

Several advantages and disadvantages have been cited for image collection with a slow-scan CCD camera. Here we explore its use for cryo-EM single particle reconstruction and present two practical examples. The icosahedral adenovirus (Ad) type 2 ( approximately 150 MDa) was reconstructed from 396 particle images. The Fourier shell correlation (FSC) 0.5 threshold and the Fourier shell phase residual (FSPR) 45 degrees criterion yielded 17 AA resolution for the ordered viral capsid. Visual comparison with the filtered Ad2 crystallographic hexon confirmed a resolution range of 15-17 A. The asymmetric DNA-PKcs protein (470 kDa) was reconstructed from 9,473 particle images, using a previously published reconstruction based on class-sum images as an orientational search model [Chiu et al. (1998) J. Mol. Biol. 284:1075-1081]. FSC and FSPR methods yielded 17 A resolution for the new DNA-PKcs reconstruction, indicating a small but noticeable improvement over that of the class-sum based reconstruction. Despite the lack of symmetry for DNA-PKcs and its lower image contrast compared to Ad2 (0.8% vs. 2.5%), the same resolution was obtained for both particles by averaging significantly more DNA-PKcs images. Use of the CCD camera enables the microscopist to adjust the electron beam strength interactively and thereby maximize the image contrast for beam sensitive samples. On-line Fourier transformation also allows routine monitoring of drift and astigmatism during image collection, resulting in a high percentage of micrographs suitable for image processing. In conclusion, our results show that digital image collection with the YAG-scintillator slow-scan CCD camera is a viable approach for 3D reconstruction of both symmetric and asymmetric particles.

Motivated cultural cognition: the impact of implicit cultural theories on dispositional attribution varies as a function of need for closure

The authors propose that need for closure (NFC) leads attributors to respond to an ambiguous social event by increasing reliance on implicit theories received from acculturation. Hence, the influence of NFC should be shaped by chronically accessible knowledge structures in a culture, and, likewise, the influence of culture should be moderated by epistemic motives such as NFC. The specific hypotheses drew on past findings that North American and Chinese attributors possess differing implicit social theories, North Americans conceiving of individuals as autonomous agents and Chinese conceiving of groups as autonomous. The present studies found the predicted pattern that among North American participants, NFC increased attributions to personal but not group dispositions. Among Chinese participants, NFC increased attributions to group but not personal dispositions. The findings are discussed in light of an emerging dynamic account of culture and cognition.

Motivated cultural cognition: the impact of implicit cultural theories on dispositional attribution varies as a function of need for closure

The authors propose that need for closure (NFC) leads attributors to respond to an ambiguous social event by increasing reliance on implicit theories received from acculturation. Hence, the influence of NFC should be shaped by chronically accessible knowledge structures in a culture, and, likewise, the influence of culture should be moderated by epistemic motives such as NFC. The specific hypotheses drew on past findings that North American and Chinese attributors possess differing implicit social theories, North Americans conceiving of individuals as autonomous agents and Chinese conceiving of groups as autonomous. The present studies found the predicted pattern that among North American participants, NFC increased attributions to personal but not group dispositions. Among Chinese participants, NFC increased attributions to group but not personal dispositions. The findings are discussed in light of an emerging dynamic account of culture and cognition.

Review: resolution issues in single-particle reconstruction

Specific factors that affect the resolution of single-particle reconstructions are discussed. We present reconstructions of six particles (DNA-dependent protein kinase catalytic subunit, alphaB-crystallin, the ribonucleoprotein vault, hepatitis A virus, adenovirus type 2, and the adenovirus type 12/alpha(v)beta5 integrin complex), which have a variety of symmetries (asymmetric to 60-fold) and a wide range of molecular masses (470 kDa to 150 MDa). In the case of icosahedral viruses, we have found that applying a "soft" mask to remove regions of disordered density improves the resolution given by the Fourier shell correlation 0.5 criterion. This masking procedure is also useful during refinement to improve the quality of the reference model and thus aid in precise alignment of the particle images. For asymmetric particles, we note that image classification, although often a necessary step to generate a first reconstruction, can limit the achievable resolution. The diameter of the particle and the available computational power can also affect the resolution, as can structural variability within the particle.

Cloning and characterization of T-cell lymphoma invasion and metastasis 2 (TIAM2), a novel guanine nucleotide exchange factor related to TIAM1

TIAM1 is a guanine nucleotide exchange factor that was identified in a screen for genes that increase the invasiveness of T lymphoma cell lines (Habets et al., 1994, Cell 77(4): 537-549). We have identified a gene, T-cell lymphoma invasion and metastasis 2 (HGMW-approved symbol TIAM2), with significant identity to the carboxyl-terminal region of the TIAM1 and mapped it to 6q25. TIAM2 is expressed as an approximately 3.3-kb transcript in cerebrum and as an approximately 4.4-kb transcript in the cerebellum and testis. The approximately 4. 4-kb message encodes a longer form of the approximately 3.3-kb mRNA predicted protein, and both contain homology to the Dbl-homologous region (70%) and Pleckstrin-homologous (54%) regions of TIAM1. We have purified TIAM2 and shown it to have GDP-GTP exchange activity. In situ hybridizations demonstrate TIAM2 expression in the E13.5 telencephalon of mouse embryos and in the cerebral cortex, hippocampus, and ependyma of adult mouse brains.

Structure of adenovirus complexed with its internalization receptor, alphavbeta5 integrin

The three-dimensional structure of soluble recombinant integrin alphavbeta5 bound to human adenovirus types 2 and 12 (Ad2 and -12) has been determined at approximately 21-A resolution by cryoelectron microscopy (cryo-EM). The alphavbeta5 integrin is known to promote Ad cell entry. Cryo-EM has shown that the integrin-binding RGD (Arg-Gly-Asp) protrusion of the Ad2 penton base protein is highly mobile (P. L. Stewart, C. Y. Chiu, S. Huang, T. Muir, Y. Zhao, B. Chait, P. Mathias, and G. R. Nemerow, EMBO J. 16:1189-1198, 1997). Sequence analysis indicated that the Ad12 RGD surface loop is shorter than that of Ad2 and probably less flexible, hence more suitable for structural characterization of the Ad-integrin complex. The cryo-EM structures of the two virus-receptor complexes revealed a ring of integrin density above the penton base of each virus serotype. As expected, the integrin density in the Ad2 complex was diffuse while that in the Ad12 complex was better defined. The integrin consists of two discrete subdomains, a globular domain with an RGD-binding cleft approximately 20 A in diameter and a distal domain with extended, flexible tails. Kinetic analysis of Ad2 interactions with alphavbeta5 indicated approximately 4.2 integrin molecules bound per penton base at close to saturation. These results suggest that the precise spatial arrangement of five RGD protrusions on the penton base promotes integrin clustering and the signaling events required for virus internalization.

A helper-independent adenovirus vector with E1, E3, and fiber deleted: structure and infectivity of fiberless particles

The adenovirus (Ad) fiber protein largely determines viral tropism through interaction with specific cell surface receptors. This molecule may also be involved in virion assembly or maturation, as some previously characterized fiber mutants were defective for processing of viral structural proteins. We previously described packaging cell lines that express Ad type 5 (Ad5) fiber and can complement the temperature-sensitive Ad fiber mutant H5ts142. We have now used these packaging cells to construct a new adenoviral vector (Ad5.betagal.DeltaF) with E1, E3, and L5 (fiber) deleted and analyzed the fiber null phenotype. Ad5.betagal.DeltaF growth was completely helper independent, and fiberless particles were produced by a single final round of growth in 293 cells. Cryoelectron microscopic studies and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that the structure and composition of these particles was nearly identical to those of first-generation Ad vectors. As expected, fiberless particles had reduced infectivity on epithelial cells, but they retained the ability to infect monocytic cells via an integrin-dependent pathway. These studies provide a novel approach to developing retargeted Ad gene therapy vectors.

Cryo-EM imaging of the catalytic subunit of the DNA-dependent protein kinase

The DNA-dependent protein kinase (DNA-PK) plays an important role in mammalian DNA double-strand break repair and immunoglobulin gene rearrangement. The DNA-PK holoenzyme is activated by assembly at DNA ends and is comprised of DNA-PKcs, a 460 kDa protein kinase catalytic subunit, and Ku, a 70 kDa/80 kDa heterodimeric DNA-targeting component. We have solved the three-dimensional structure of DNA-PKcs to approximately 21 A resolution by analytically combining images of nearly 9500 individual particles extracted from cryo-electron micrographs. The DNA-PKcs protein has an open, pseudo 2-fold symmetric structure with a gap separating a crown-shaped top from a rounded base. Columns of density are observed to protrude into the gap from both the crown and the base. Measurements of the enclosed volume indicate that the interior of the protein is largely hollow. The structure of DNA-PKcs suggests that its association with DNA may involve the internalization of double-stranded ends.

Modification of a receptor-binding surface of epidermal growth factor (EGF): analogs with enhanced receptor affinity at low pH or at neutrality

Six mutants of human epidermal growth factor (EGF), which carry single point substitutions within a surface patch proposed to juxtapose the bound receptor, were prepared and characterized for receptor affinity and mitogenicity. Receptor affinities relative to EGF are G12Q > H16D > Y13W > Q43A approximately = H16A approximately = EGF >> L15A. Notably, the reduced receptor affinity of mutant L15A indicates that Leu15 probably contributes substantially to receptor binding whereas unaltered receptor affinities observed for analogs H16A and Q43A indicate that neither His16 nor Gln43 contributes significantly to this interaction. On the other hand, the observed enhanced receptor affinities of analogs G12Q, Y13W and H16D highlight surface loci where additional productive receptor-binding contacts can be introduced. Interestingly, at acidic pH analog H16A reveals substantially greater receptor affinity than that of EGF, a property which may offer enhanced therapeutic utility in acidic environments in vivo.