[The prognosis and clinicopathological characteristics of 70 gastric cancer patients with elevated serum AFP]

Objective: This study aimed to review the clinicopathological characteristics and prognosis of advanced gastric cancer patients with elevated serum Alpha-fetoprotein (AFP). Methods: From August 2006 to May 2016, 70patients with advanced gastric cancer were enrolled retrospectively. All these patients had pathologically confirmed gastric adenocarcinoma, had a serum AFP level of more than 20 ng/ml, and received at least first-line treatment. The clinicopathological data and follow-up data were collected for analysis. Results: Liver metastasis was more common in patients with AFP≥1 000 ng/ml, compared with AFP<1 000 ng/ml patients (78.6% vs 57.1%, P=0.064). In patients whose AFP level decreased ≥50% after first-line chemotherapy, the disease control rate and overall survival were both better than those in patients with AFP decreased <50%(96.3% vs 56.7%, P=0.001; 17.2 m vs 8.8 m P=0.007). The overall survival of all these 70 patients ranged from 0.5-50.0 months. 31 patients received chemotherapy only, and 39 patients received combined therapy modality. The overall survival of these two groups were similar(11.0 m and 15.6 m, respectively, P=0.070). Conclusions: Serum AFP-elevated gastric cancer is a special subtype of gastric cancer. It's a heterogeneous cancer with different clinical outcomes. The extent of decrease of serum AFP level during follow-up may be a sensitive prognostic and predictive biomarker. Liver metastasis were more common in these patients, and combined treatment may improve survival.

[Tracing hepatitis C virus transmission by using high-throughput sequencing technique]

OBJECTIVE

An approach for analysis of hepatitis C virus (HCV) quasispecies using Hiseq high-throughput sequencing (hereinafter referred to as Hiseq sequencing) technique was developed and then applied to investigate a possible case of HCV needle sharing transmission.

METHODS

One case of HCV antibody seroconversion (P1) was found in a methadone clinic on January 15, 2015. Four HCV antibody positive injecting drug users (IDUs), P2 to P5, suspected to be involved in needle sharing transmission with P1 during the period (after March 24, 2014) that P1 may be infected with HCV were investigated, and another 28 HCV antibody positive IDUs were selected as controls (C1 to C28). These controls came from the same methadone clinic or lived in the same town with P1. The RNAs were extracted from the plasma specimens and then reverse-transcribed into cDNA. After HCV subtyping, Hiseq sequencing was performed to detect and sequence the HCV quasispecies (263 bp) in the specimens with the same subtype as P1. The frequency of quasispecies was counted and ranked. Intrapersonal and interpersonal genetic distance and phylogenetic tree were calculated.

RESULTS

The HCV subtype of specimen P1 was 3b. All the other specimens with the same subtype were P2, C7, C12, C14, C15, C16, C19, C20 and C28. Hiseq sequencing was successfully performed in 9 out of these 10 specimens, and 249 753 to 1 086 333 (average 869 608) cleaned sequences representing 3 to 172 (average 48) unique HCV quasispecies were obtained. The medians (P50) of intrapersonal genetic diversities from the 9 specimens were 0.4% to 12.3%. The P50 (P25, P75) of genetic diversities between P1 and the other 8 specimens were 19.0% (18.4%, 19.8%), 10.4% (2.8%, 18.3%), 19.6% (17.8%, 21.4%),24.9% (23.8%, 26.1%), 19.8% (18.7%, 20.7%), 20.1% (18.9%, 21.2%), 20.6% (20.0%, 21.1%), 23.6% (22.4%, 24.8%). There were no significant difference between the genetic diversities of P1 and P2 and those of P1 and other 7 specimens (H=9.40, P=0.100). The genetic diversities between few HCV quasispecies from P1 and few ones from C7 were 0. Phylogenetic tree analysis indicated that there was no HCV transmission relationship between P1 and P2, but there was HCV transmission relationship between P1 and C7.

CONCLUSION

With the feature of high-throughput, easier operation and lower cost, Hiseq sequencing technique has high practical value in tracing HCV transmission at the quasispecies level.

Prevalence of Helicobacter pylori infection and its association with lipid profiles

OBJECTIVE

To evaluate the prevalence of Helicobacter pylori (H. pylori, HP) infection in subjects receiving routine physical examination and its associations with age, sex, body mass index (BMI) and lipid profiles.

MATERIALS AND METHODS

Clinical information of 22,103 individuals who took routine physical examinations, including that on age, gender, height, weight, triglyceride, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and data of HP infection were collected and analyzed.

RESULTS

H. pylori infection rate in 22,103 subjects taking routine physical examination was 44.5 %. More men tended to be infected with H. pylori than women (45.9 % vs 42.8 %; p < 0.01). The highest positive rate group was in the age group of 30-39 years (46.8 %) and the lowest rate was in the age group younger than 30 years (40.5 %). The obese had higher infection rate than the non-obese (p < 0.01). Mann-Whitney U test was used to explore the relationships between lipid profiles and H. pylori infection. There were significant associations among HDL, triglyceride and HP infection (p < 0.01). However, significant differences were not confirmed between cholesterol, LDL and H. pylori infection.

CONCLUSION

H. pylori infection was common among subjects receiving physical examination in Shanghai and it was most significantly associated with HDL and triglyceride, indicating that H. pylori might be a new cardiovascular risk factor (Tab. 3, Ref. 23).

[Study on the threshold of HIV-1 drug resistance in Dehong prefecture of Yunnan province in 2014]

OBJECTIVE

To study the HIV-1 genotypes and transmitted drug resistance (TDR) in Dehong prefecture of Yunnan province in 2014.

METHODS

A total of 70 plasma samples of recently reported HIV-infected individuals between 16 and 25 years old were collected in Dehong prefecture from January to August 2014. Among them, 58 samples which met the criterion of HIV drug resistance threshold survey (HIVDR-TS) were subjected to genetic drug resistance detection.

RESULTS

50 plasma samples were successfully sequenced and analyzed. Among them, 34.0% were Chinese and 66.0% were Burmese. Based on pol sequences, all the identified HIV genotypes would include CRF01_AE (28.0%), subtype C(20.0%), URF(20.0% ), CRF62_BC(10.0% ), CRF08_BC(8.0% ), CRF07_BC (4.0%), CRF64_BC(4.0%), subtype B(4.0%) and CRF55_01B(2.0%). One drug, which resistant mutation to proteinase inhibitors had been detected in one sequence. Based on the statistical method of HIVDR-TS, the prevalence of transmitted HIV-1 drug resistance was adjusted as <5%.

CONCLUSION

The proportion of Burmese was relatively higher among those newly reported HIV-infected individuals aged 16 to 25 in Dehong. We noticed that the novel circulating recombinant forms began to function. However, the level of transmission through HIV-1 drug resistant strains still kept low in Dehong.

[Intervention of systolic pressure and left ventricular hypertrophy in rats under cold stress]

OBJECTIVE

To investigate the effects of different drugs on systolic blood pressure (SBP) and left ventricular hypertrophy (LVH) in spontaneously hypertensive rats under cold stress.

METHODS

A total of 40 male spontaneously hypertensive rats aged 10 weeks (160~200 g) were given adaptive feeding for 7 days at a temperature of 20±1°C and then randomly divided into control group, cold stress group, metoprolol group, amlodipine group, and benazepril group, with 8 rats in each group. SBP, body weight, and heart rate were measured once a week. After the rats were sacrificed by exsanguination, left ventricular weight (LVW) was measured, and left ventricular weight index (LVWI; mg/g) was calculated. Radioimmunoassay was used to measure the concentrations of endothelin-1 (ET-1) and angiotensin-II (Ang-II) in plasma and myocardium, and the chemical method was used to measure the concentrations of nitric oxide (NO) in plasma and myocardium. RT-PCR was used to measure the mRNA expression of endothelin-A receptor.

RESULTS

Compared with the cold stress group, all medication groups showed significant reductions in SBP since week 5 (P<0.05). The cold stress group showed a significant increase in LVWI compared with the control group (3.38±0.27 mg/g vs 2.89±0.19 mg/g, P<0.05). The amlodipine group showed a significant reduction in LVWI compared with the cold stress group (2.98±0.28 mg/g vs 3.38±0.27 mg/g, P<0.05). The cold stress group showed a significant reduction in plasma NO concentration compared with the control group (104.9±19.5 μmol/L vs 129.3±17.8 μmol/L, P<0.05) ; compared with the cold stress group, all the medication groups showed significant increases in blood NO concentration (P<0.05). The cold stress group showed a significant increase in myocardial ET-1 concentration compared with the control group (6.3±1.5 pg/100 mg vs 4.5±1.9 pg/100 mg, P<0.05) ; compared with the cold stress group, the amlodipine group showed a significant reduction in myocardial ET-1 concentration (4.4±1.0 pg/100 mg vs 6.3±1.5 pg/100 mg, P<0.05). The cold stress group had significantly higher mRNA expression of endothelin-A receptor than the control group (0.86±0.23 vs 0.45±0.16, P<0.01) ; compared with the cold stress group, the amlodipine group showed a significant reduction in the mRNA expression of endothelin-A receptor (0.41±0.14 vs 0.86±0.23, P<0.01).

CONCLUSION

Amlodipine can reduce the increase in SBP and inhibit LVH in spontaneously hypertensive rats under cold stress.

[Correlation of hepatitis B virus X antigen expression with liver cell apoptosis]

OBJECTIVE

To study the roles of hepatitis B virus (HBV) X antigen (HBxAg) in development of HBV-related liver diseases and carcinogenesis.

METHODS

Liver tissues were collected from patients with HBV infection (HBV carriers, n = 14; chronic hepatitis B (CHB), n = 24), HBV-related liver cirrhosis (LC, n = 20), or hepatocellular carcinoma (HCC, n = 20). Immunohistochemistry was used to detect the expression of HBxAg and the host apoptosis-related genes Fas and Fas ligand (Fas-L). The correlations of HBxAg with HBV DNA level in serum, inflammation grade, and fibrosis stage were statistically analyzed. Liver inflammation grade and fibrosis stage were in accordance with Knodell standard. x2test and Fisher's exact test were adopted in count data, x2split method was adopted in pariwise comparisons between multiple samples, Rank-sum test was adopted in ranked data, Spearman rank correlation analysis was adopted in correlation analysis.

RESULTS

The rates of HBxAg-positivity were similar between the patients with HBV infection (71.1%), LC (60.0%), and HCC (65.0%) (x2= 0.754, P = 0.686). The rates of Fas- and Fas-L-positivity in liver cells were also similar between the three groups (Fas: 28.9% vs. 20.0% vs. 5.0%, x2= 4.667, P = 0.101; Fas-L: 36.8% vs. 50.0% vs. 60.0%, x2= 2.988, P = 0.225). However, the positive rate of Fas in lymphocytes of liver tissue was significantly higher in the HCC patients than in the HBV-infected patients (90.0% vs. 68.4%, Z = -4.360, P = 0.00001). The expressions of HBxAg and Fas-L corresponded to regions of severe inflammation in tissues from LC patients and some HCC patients. Furthermore, the expression of HBxAg was positively correlated with Fas (r = 0.304, P = 0.02) and Fas-L (r = 0.368, P = 0.004) in the HBV-infected patients and LC patients, and the expression of Fas was positively correlated with that of Fas-L (r = 0.448, P = 0.0004). Patients with high and medium loads of HBV DNA showed significantly higher rates of HBxAg-positivity than those with low loads (88.9% and 69.2% vs. 26.7%, P less than 0.05).

CONCLUSION

In the early stage of chronic HBV infection, HBxAg may induce liver cell apoptosis by up-regulating Fas expression, and in the later stage, HBxAg may induce immune escape by up-regulating Fas-L expression in liver cells. Together, HBxAg and high HBV DNA load may promote chronic HBV infection and progression to hepatocarcinogenesis.

Value of ecosystem hydropower service and its impact on the payment for ecosystem services

Hydropower is an important service provided by ecosystems. We surveyed all the hydropower plants in the Zagunao River Basin, Southwest China. Then, we assessed the hydropower service by using the InVEST (The Integrated Value and Tradeoff of Ecosystem Service Tools) model. Finally, we discussed the impact on ecological compensation. The results showed that: 1) hydropower service value of ecosystems in the Zagunao River Basin is 216.29 Euro/hm(2) on the average, of which the high-value area with more than 475.65 Euro/hm(2) is about 750.37 km(2), accounting for 16.12% of the whole watershed, but it provides 53.47% of the whole watershed service value; 2) ecosystem is an ecological reservoir with a great regulation capacity. Dams cannot completely replace the reservoir water conservation function of ecosystems, and has high economic and environmental costs that must be paid as well. Compensation for water conservation services should become an important basis for ecological compensation of hydropower development. 3) In the current PES cases, the standard of compensation is generally low. Cascade development makes the value of upstream ecosystem services become more prominent, reflecting the differential rent value, and the value of ecosystem services should be based on the distribution of differentiated ecological compensation.

Mutation effects of C2+ ion irradiation on the greasy Nitzschia sp

Screening and nurturing algae with high productivity, high lipid content and strong stress resistance are very important in algae industry. In order to increase the lipid content, the Nitzschia sp. was irradiated with a 3MeV C(2+) beam. The sample pretreatment method was optimized to obtain the best mutagenic condition and the survival ratio curve. The positive mutants with a significant improvement in lipid content were screened and their C(2+) mutagenic effects were analyzed by comparing the greasiness and growth characteristics with the wild type algae. Results showed that when the Nitzschia sp. was cultivated in nutritious medium containing 10% glycerol solution, and dried on the filter for 5 min after centrifugation, the realization of the microalgae heavy ion mutagenesis could be done. The survival ratio curve caused by C(2+) irradiation was proved to be "saddle-shaped". A positive mutant was screened among 20 survivals after irradiation, the average lipid content of the mutation increased by 9.8% than the wild type after 4 generations. But the growth rate of the screened mutation didn't change after the heavy ion implantation compared to the wild type algae.

Synthesis and antitumor activity of novel 2-(1-substituted-piperidin-4-ylamino)quinazolines as antitumor agents

A variety of novel 2-(1-substituted-piperidine-4-ylamino)quinazoline derivatives were prepared and their antiproliferative activities on five cancer cell lines were evaluated by MTT assay. Quinazolines 4j-4l, 5a, 5b and 5d bearing a small hydrophobic alkyl group on piperidine ring exhibited potent antitumor activities with IC50 values at micromolar level. Compound 41 displayed significant in vivo antitumor activity with 72.9% inhibition on H22 tumor growth and 80% inhibition on Lewis lung cancer growth at a dose of 200 mg x kg(-1).

Artificial permeability and antibonding magnetic resonance in a copper-structured metamaterial with symmetry-broken ring-plate resonators

We numerically investigate the antibonding magnetic resonance in a metamaterial composed of rings and plates, with a particular attention to the influence of broken structural symmetry on the Fano-type transmission spectrum as well as the resonant artificial permeability. From the simulation results, it is obvious that the antibonding magnetic resonance with strong magnetic-dipole coupling is responsible for the Fano-type profile, since an increase of the structural asymmetry extent to reduce the magnetic field confinement in one of the gaps will form, in contrary, a Lorentzian resonance dip. The dual excitation pathways, i.e., electric and magnetic resonances, at destructive interference are the underlying reason of the Fano-type transmission response. Additionally, the structural-asymmetry dependence of the artificial permeability shows that the broken symmetry can strongly modify the effective permeability due to the altering magnetic-dipole interactions. It is found that an anti-resonant curve of permeability versus frequency will be resulted in if significant symmetry-broken structure is introduced.

[The cloning, expression, purification and immunological identification of wild-type and mutant hepatitis B virus X gene in pGEX-6P-2 system]

To settle the foundation for the future research on the influence of wild and mutant (A1762T/ G1764A) HBV X gene on the progress of chronic HBV infection and hepatic tumorigenicity, wild and mutant (A1762T/G1764A) HBxAgs expression system was constructed. The wild and mutant (A1762T/ G1764A) HBV X genes were amplified with polymerase chain reaction (PCR) from HBV genome were inserted into pGEX-6P-2 and confirmed by sequencing respectively. Prokaryotic expression vectors pGEX-6P-2-hbvx(w) and pGEX-6P-2-hbvx(m) (A1762T/G1764A) were constructed and transformed to Trans1-blue; wild and mutant HBxAgs were expressed through IPTG induction respectively; after refolding of inclusion body, the wild and mutant HBxAgs were purified with GSTrap FF; and analysised by SDS-PAGE, Western blot and ELISA. SDS-PAGE analysis showed that the expression system was able to express target protein efficiently; the concentrations of purified wild HBxAg and mutant HBxAg were 4.88 mg/mL and 5.07 mg/mL respectively; Western blot analysis certified both the wild HBxAg and the mutant HBxAg could be recognized by the same monoclonal antibody against HBxAg; the two expressed fusion antigens coated in microtiter plate were able to react with the sera of HBV infected patients but not with the sera from healthy donors in ELISA. Results demonstrated that we successfully established a system for expression of hepatitis B x antigen and lay the foundation for further research on the role and molecular mechanisms of the mutant HBxAg in the progress of chronic HBV infection and hepatic tumorigenicity.

Activation of Akt and MAPK pathways enhances the tumorigenicity of CD133+ primary colon cancer cells

Cancer stem cells (CSCs) play an important role in carcinogenesis, resistance to treatment and may lead to cancer recurrence and metastasis. However, the molecular mechanism of CSC involved in these events needs to be further elucidated. In this study, CD133(+) colon cancer cells were cultured, which showed CSC properties both in vitro and in vivo from metastatic tissue. Upstream molecules in Akt and mitogen-activated protein kinase (MAPK) pathways were preferentially expressed in these CD133(+) cells, as revealed by a global gene chip. The kinase activities of Akt and extracellular signal-regulated kinase (Erk)1/2 were also significantly upregulated in CD133(+) cells. In addition, the clonogenic growth of CD133(+) cell was reduced greatly by inhibiting the activity of Akt and Erk1/2. The results revealed the Akt and MAPK pathways were involved in the tumorigenesis of CD133(+) colon cancer cells, suggesting that molecules in these two pathways might be potential targets in the future therapy.

Myocardial material parameter estimation: a comparison of invariant based orthotropic constitutive equations

This study investigated a number of invariant based orthotropic and transversely isotropic constitutive equations for their suitability to fit three-dimensional simple shear mechanics data of passive myocardial tissue. A number of orthotropic laws based on Green strain components and one microstructurally based law have previously been investigated to fit experimental measurements of stress-strain behaviour. Here we extend this investigation to include several recently proposed functional forms, i.e. invariant based orthotropic and transversely isotropic constitutive relations. These laws were compared on the basis of (i) 'goodness of fit': how well they fit a set of six shear deformation tests, (ii) 'variability': how well determined the material parameters are over the range of experiments. These criteria were utilised to discuss the advantages and disadvantages of the constitutive laws. It was found that a specific form of the polyconvex type as well as the exponential Fung-type law from the previous study were most suitable for modelling the orthotropic behaviour of myocardium under simple shear.

Combination of short CAG and GGN repeats in the androgen receptor gene is associated with acne risk in North East China

BACKGROUND

Acne vulgaris is one of the most common skin disorders, and androgen is known to play a key role in the development of acne. However, the exact genetic mechanism by which androgen receptor (AR) gene affects acne development is still unclear.

OBJECTIVE

Our study aimed to investigate whether CAG and GGN polymorphism of the AR gene are associated with acne risk.

PATIENTS AND METHODS

Two hundred thirty-eight patients and 207 controls were included in the study. The repeat lengths of the AR gene were determined by GeneScan analysis.

RESULTS

Men with CAG < 23 and women with CAG < 24 had significant risk compared to those men with CAG > or = 23 [odds ratio (OR), 2.07; 95% confidence interval (95% CI), 1.21-3.54] and women with CAG > or = 24 (OR, 2.05; 95% CI, 1.18-3.56). In males, GGN repeats, considered independently of the CAG repeat, have no significant effect on the acne risk; however, when combined with CAG repeats, the acne patients exhibited significantly higher frequency of the haplotypes CAG < 23/GGN < or = 23 (OR, 3.33; 95% CI, 1.10-10.07; P < 0.05) compared with the controls.

CONCLUSION

Our results of this study strongly indicated that a shorter CAG repeat length and specific haplotypes of AR attributed to the risk of acne development and thus could serve as a susceptibility marker.

Optimization of the anti-(human CD3) immunotoxin DT389-scFv(UCHT1) N-terminal sequence to yield a homogeneous protein

The production and regulatory approval processes for biopharmaceuticals require detailed characterization of potential products. Therapeutic proteins should preferably be homogeneous, although limited, reproducible, heterogeneity may be tolerated. A diphtheria toxin-based anti-(human CD3) immunotoxin, DT389-scFv(UCHT1), was expressed in Escherichia coli and purified following refolding [DT389 corresponds to amino acids 1-389 of diphtheria toxin, scFv is single-chain variable-region antibody fragment and UCHT1is an anti-(human CD3) monoclonal antibody]. Biochemical characterization of this molecule by MS and N-terminal sequencing by Edman degradation revealed that the protein was heterogeneous at the N-terminus, containing species both with (60%) and without (40%) the initiator methionine residue. In an attempt to generate an N-terminally homogeneous molecule, a panel of seven N-terminal variants was designed, based on the published specificity of bacterial methionine aminopeptidase. Following bacterial expression, partial purification and separation on SDS/PAGE, these proteins were subjected to N-terminal sequencing by Edman degradation. Three of the mutants yielded a 100% homogeneous amino acid sequence. By contrast, the original DT389-scFv(UCHT1) protein and four variant proteins yielded two sequences with varying ratios corresponding to species with and without methionine. The N-terminal sequences of the three homogeneous clones were MLADD and MLDD, where the methionine was completely retained, and SADD, where the methionine was completely removed. One of the homogeneous mutants (SADD) was expressed, refolded and purified and found to be equipotent with the parent immunotoxin. Thus, using a rational mutagenesis approach, three N-terminally homogeneous variants of DT389-scFv(UCHT1) have been identified, at least one of which is functionally indistinguishable from the parent immunotoxin. This approach is generally applicable to biopharmaceutical production and immunotoxin development in particular.

frizzled 9 is expressed in neural precursor cells in the developing neural tube

The wnt signaling pathway has important functions in nervous system development. To better understand this process we have cloned and analyzed the expression of the wnt receptor, frizzled 9, in the developing nervous system in mouse, chick and zebrafish. The earliest expression of mouse frizzled 9 mRNA expression begins at E8.5 with expression throughout the entire rostral-caudal neuraxis. This early expression pattern within the neural tube appears to be conserved between chick and zebrafish. Expression becomes restricted to a ventral domain in the mouse ventricular zone at E11.5, a region specified to give rise to neurons and glia. Using a polyclonal antibody to MFZ9 further shows expression limited to neural restricted precursors cells.

Inverse 18O labeling mass spectrometry for the rapid identification of marker/target proteins

Systematic analysis of proteins is essential in understanding human diseases and their clinical treatments. To achieve the rapid and unambiguous identification of marker or target proteins, a new procedure termed "inverse labeling" is proposed. With this procedure, to evaluate protein expression of a diseased or a drug-treated sample in comparison with a control sample, two converse labeling experiments are performed in parallel. The perturbed sample (by disease or by drug treatment) is labeled in one experiment, whereas the control is labeled in the second experiment. When mixed and analyzed with its unlabeled counterpart for differential comparison using mass spectrometry, a characteristic inverse labeling pattern of mass shift will be observed between the two parallel analyses for proteins that are differentially expressed. In this study, protein labeling is achieved through 18O incorporation into peptides by proteolysis performed in [18O]water. Once the peptides are identified with the characteristic inverse labeling pattern of 18O/16O ion intensity shift, MS data of peptide fingerprints or peptide sequence information can be used to search a protein database for protein identification. The methodology has been applied successfully to two model systems in this study. It permits quick focus on the signals of differentially expressed proteins. It eliminates the detection ambiguities caused by the dynamic range of detection on proteins of extreme changes in expression. It enables the detection of protein modifications responding to perturbation. This strategy can also be extended to other protein-labeling methods, such as chemical or metabolic labeling, to realize the same benefits.

Collagen gel overlay induces two phases of apoptosis in MDCK cells

We previously demonstrated that collagen gel overlay induced cell remodeling to form lumen and apoptosis in Madin-Darby canine kidney cells. In the present study, we established that collagen gel overlay-induced apoptosis was initiated at areas exclusive of cell remodeling within 24 h (first phase) and extended into areas of cell remodeling within 48 h (second phase). Collagen gel overlay-induced apoptosis was accompanied by selective proteolysis of focal adhesion kinase (FAK), talin, p130cas, and c- src. Upon collagen gel overlay, FAK was initially degraded into a 90-kDa product during the first phase and subsequently into a 80-kDa product during the second phase. Collagen gel overlay-induced apoptosis of focal adhesion complex proteins and apoptosis of the first phase could be blocked only by a protease inhibitor cocktail. In addition, we found that both DEVD-fmk and ZVAD-fmk inhibited secondary proteolysis of FAK, but only ZVAD-fmk blocked collagen gel overlay-induced apoptosis of the second phase. Finally, collagen gel overlay-induced apoptosis and proteolysis of focal adhesion complex proteins were completely inhibited by the combination of protease inhibitor cocktail and ZVAD-fmk. Taken together, collagen gel overlay induces two phases of apoptosis; the first phase is dependent on proteolysis of focal adhesion complex proteins, and the second phase on activation of caspases.

TBL2, a novel transducin family member in the WBS deletion: characterization of the complete sequence, genomic structure, transcriptional variants and the mouse ortholog

Williams-Beuren syndrome (WBS) is a developmental disorder with multi-system manifestations caused by haploinsufficiency for contiguous genes deleted in chromosome region 7q11.23. The size of the deletion is similar in most patients due to a genomic duplication that predisposes to unequal meiotic crossover events. While hemizygosity at the elastin locus is responsible for the cardiovascular features, the contribution of other genes to the WBS phenotype remains to be demonstrated. We have identified a novel gene, TBL2, in the common WBS deletion. TBL2 is expressed as a 2. 4-kb transcript predominantly in testis, skeletal muscle, heart and some endocrine tissues, with a larger approximately 5-kb transcript detected ubiquitously at lower levels. TBL2 encodes a protein with four putative WD40-repeats. An alternatively spliced transcript in TBL2 introduces a novel second exon with an in frame stop codon. This mRNA encodes a 75 amino acid protein with 43 amino acids identical to TBL2 at the N-terminus and no known functional domain. The mouse homolog, Tbl2, shows 84% sequence identity at the nucleotide level and 92% similarity at the amino acid level. Comparison of the mouse and human sequences identifies a conserved region that extends upstream of the previously published sequence with an initiation codon common to both species that adds 21 amino acids at the N-terminus. The Tbl2 gene has been mapped to mouse chromosome 5 in a region of conserved synteny with human 7q11.23. Since haploinsufficiency has been shown for other WD-repeat containing proteins, hemizygosity of TBL2 may contribute to some of the aspects of the complex WBS phenotype.

Specific chromosome alterations in fluconazole-resistant mutants of Candida albicans

The exposure of Candida albicans to fluconazole resulted in the nondisjunction of two specific chromosomes in 17 drug-resistant mutants, each obtained by an independent mutational event. The chromosomal changes occurred at high frequencies and were related to the duration of the drug exposure. The loss of one homologue of chromosome 4 occurred after incubation on a fluconazole medium for 7 days. A second change, the gain of one copy of chromosome 3, was observed after exposure for 35 or 40 days. We found that the mRNA levels of ERG11, CDR1, CDR2, and MDR1, the candidate fluconazole resistance genes, remained either the same or were diminished. The lack of overexpression of putative drug pumps or the drug target indicated that some other mechanism(s) may be operating. The fluconazole resistance phenotype, electrophoretic karyotypes, and transcript levels of mutants were stable after growth for 112 generations in the absence of fluconazole. This is the first report to demonstrate that resistance to fluconazole can be dependent on chromosomal nondisjunction. Furthermore, we suggest that a low-level resistance to fluconazole arising during the early stages of clinical treatment may occur by this mechanism. These results support our earlier hypothesis that changes in C. albicans chromosome number is a common means to control a resource of potentially beneficial genes that are related to important cellular functions.

Analysis of diagnostic metabolites by capillary electrophoresis-mass spectrometry

We describe here a procedure by capillary electrophoresis-mass spectrometry (CE-MS) for the direct analysis of urine samples on diagnostic metabolites, which are present in patient urine with metabolic disorders. The method was demonstrated using urine samples spiked with diagnostic metabolites, including glutathione for gamma-glutamyl transpeptidase deficiency, pyroglutamate for generalized glutathione deficiency, adenylosuccinate for adenylosuccinase deficiency, omithine for gyrate atrophy, histidine for histidinemia, and homogentisic acid for alcaptonuria, at concentrations similar to those found in patients' urine. A coaxial sheath liquid flow was used for coupling CE and MS in electrospray ionization mode. Identification of the metabolites is based on their molecular weights and fragmentation patterns. The CE-MS method is highly specific and sensitive comparing to the previously reported method using migration time and UV absorption for identification. It should find broad application in clinical and pharmaceutical research and development.