Association of single-nucleotide polymorphisms in HLA class II/III region with knee osteoarthritis

OBJECTIVE

A genome-wide association study and a replication using Japanese, Spanish and Greek Caucasian populations have recently indicated two single-nucleotide polymorphisms (SNPs) (rs7775228 and rs10947262) associated with knee Osteoarthritis (OA) susceptibility. We have further evaluated the association in knee OA subjects from Han Chinese and Australian Caucasian origin.

METHODS

Two independent case-control association studies were performed using Han Chinese and Australian Caucasian populations. The two SNPs were genotyped in patients who had primary symptomatic knee OA with radiographic confirmation and/or received total knee replacement surgery as well as in matched controls. They were subjected to statistic analyses.

RESULTS

A total of 991 OA patients and 1536 controls were genotyped. No significant difference was detected in genotype or allele frequencies of the two SNPs between knee OA and control groups in the two populations (all P>0.05). The association was also negative even after stratification by sex, body mass index (BMI) and Kellgren/Lawrence scores. The significant heterogeneity was detected between Chinese and Japanese (both P<0.05). In the Caucasian samples, no significant heterogeneity was detected (both P>0.05). The result of meta-analysis showed significant association between knee OA and rs10947262 in total subjects [summary OR=1.26, 95%confidence intervals (CI)=1.07-1.27, P=3 × 10(-8)] and in Caucasian samples (summary OR=1.28, 95%CI=1.04-1.57, P=0.02).

CONCLUSION

We demonstrated no association between the two SNPs in human leukocyte antigen (HLA) class II/III region and knee OA in Han Chinese population. A significant association was detected between SNP rs10947262 and knee OA in Caucasian subjects. Further replication studies are required to identify the impact of controversial association.

Effects of TGF-beta3 and preculture period of osteogenic cells on the chondrogenic differentiation of rabbit marrow mesenchymal stem cells encapsulated in a bilayered hydrogel composite

In this work, injectable, biodegradable hydrogel composites of crosslinked oligo(poly(ethylene glycol) fumarate) and gelatin microparticles (MPs) were used to fabricate a bilayered osteochondral construct. Rabbit marrow mesenchymal stem cells (MSCs) were encapsulated with transforming growth factor-beta3 (TGF-beta3)-loaded MPs in the chondrogenic layer and cocultured with cells of different periods of osteogenic preculture (0, 3, 6 and 12 days) in the osteogenic layer to investigate the effects of TGF-beta3 delivery and coculture on the proliferation and differentiation of cells in both layers. The results showed that, in the chondrogenic layer, TGF-beta3 significantly stimulated chondrogenic differentiation of MSCs. In addition, cells of various osteogenic preculture periods in the osteogenic layer, along with TGF-beta3, enhanced gene expression for MSC chondrogenic markers to different extents. In the osteogenic layer, cells maintained their alkaline phosphatase activity during the coculture; however, mineralization was delayed by the presence of TGF-beta3. Overall, this study demonstrated the fabrication of bilayered hydrogel composites which mimic the structure and function of osteochondral tissue, along with the application of these composites as cell and growth factor carriers, while illustrating that encapsulated cells of different degrees of osteogenic differentiation can significantly influence the chondrogenic differentiation of cocultured progenitor cells in both the presence and absence of chondrogenic growth factors.

Mechanism-based inhibition of CYP1A2 by antofloxacin, an 8-NH2 derivative of levofloxacin in rats

A recent focus was to investigate whether antofloxacin, an 8-NH(2) derivative of levofloxacin, inhibited cytochrome P450 (CYP) 1A2 activity in rats. Phenacetin, the representative substrate of CYP1A2, was used as the model drug to evaluate the activity of CYP1A2. In an in vivo study, an oral single dose of antofloxacin (20 mg kg(-1)) did not affect the pharmacokinetic behaviour of phenacetin, but a multidose (20 mg kg(-1) twice daily for 7.5 days) significantly increased phenacetin's area under the curve (AUC). In an in vitro study, only when pre-incubated with beta-nicotinamide adenine dinucleotide phosphate, a reduced form (NADPH) system in rat liver microsomes, did antofloxacin inhibit phenacetin O-deethylation. The inhibition was NADPH-, pre-incubation time-, and antofloxacin concentration-dependent. A physiologically based pharmacokinetic model with mechanism-based inhibition was successfully developed for predicting the interaction between antofloxacin and phenacetin in vivo from the in vitro data. The simulated AUC was 1.4-fold of the control, which was near the observed value of 1.6-fold. From the results, it can be concluded that the inhibition of CYP1A2 by antofloxacin is mechanism-based.

Altered structural and mechanical properties in decellularized rabbit carotid arteries

Recently, major achievements in creating decellularized whole tissue scaffolds have drawn considerable attention to decellularization as a promising approach for tissue engineering. Decellularized tissues are expected to have mechanical strength and structure similar to the native tissues from which they are derived. However, numerous studies have shown that mechanical properties change after decellularization. Often, tissue structure is observed by histology and electron microscopy, but the structural alterations that may have occurred are not always evident. Here, a variety of techniques were used to investigate changes in tissue structure and relate them to altered mechanical behavior in decellularized rabbit carotid arteries. Histology and scanning electron microscopy revealed that major extracellular matrix components were preserved and fibers appeared intact, although collagen appeared looser and less crimped after decellularization. Transmission electron microscopy confirmed the presence of proteoglycans (PG), but there was decreased PG density and increased spacing between collagen fibrils. Mechanical testing and opening angle measurements showed that decellularized arteries had significantly increased stiffness, decreased extensibility and decreased residual stress compared with native arteries. Small-angle light scattering revealed that fibers had increased mobility and that structural integrity was compromised in decellularized arteries. Taken together, these studies revealed structural alterations that could be related to changes in mechanical properties. Further studies are warranted to determine the specific effects of different decellularization methods on the structure and performance of decellularized arteries used as vascular grafts.

Positive margins in laparoscopic partial nephrectomy in 855 cases: a multi-institutional survey from the United States and Europe

PURPOSE

Open partial nephrectomy has emerged as the standard of care in the management of renal tumors smaller than 4 cm. While laparoscopic radical nephrectomy has been shown to be comparable to open radical nephrectomy with respect to long-term outcomes, important questions remain unanswered regarding the oncological efficacy of laparoscopic partial nephrectomy. We examined the practice patterns and pathological outcomes following laparoscopic partial nephrectomy.

MATERIALS AND METHODS

A survey was sent to academic medical centers in the United States and in Europe performing laparoscopic partial nephrectomy. The total number of laparoscopic partial nephrectomies, positive margins, indications for intraoperative frozen biopsy as well as tumor size and position were queried.

RESULTS

Surveys suitable for analysis were received from 17 centers with a total of 855 laparoscopic partial nephrectomy cases. Mean tumor size was 2.7 cm (+/-0.6). There were 21 cases with positive margins on final pathology, giving an overall positive margin rate of 2.4%. Intraoperative frozen sections were performed selectively at 10 centers based on clinical suspicion of positive margins on excised tumor. Random biopsies were routinely performed on the resection bed at 5 centers. Frozen sections were never performed at 2 centers. Of the 21 cases with positive margins 14 underwent immediate radical nephrectomy based on the frozen section and 7 were followed expectantly.

CONCLUSIONS

Early experience with laparoscopic partial nephrectomy in this multicenter study demonstrates oncological efficacy comparable to that of open partial nephrectomy with respect to the incidence of positive margins. The practice of intraoperative frozen sections varied among centers and is not definitive in guiding the optimal surgical treatment.

Complications of laparoscopic living donor nephrectomy and their management: the UCLA experience

OBJECTIVES

Because of the shortage of cadaveric kidneys, laparoscopic living donor nephrectomy (LLDN) has become a more common option for transplant recipients. The complication rate has been reported at 6.4% to 16.5%. We present the initial University of California, Los Angeles experience with the complications and their management during LLDN.

METHODS

From January 2000 to December 2005, a single surgeon performed 300 consecutive LLDNs at our institution. A committee of urologists, nephrologists, and support staff approved each donor before surgery. After LLDN was completed, the patients received 30 mg of ketorolac intravenously every 6 hours until discharge. We reviewed the intraoperative and postoperative complications and their management at our institution.

RESULTS

Three patients required open conversion, for an overall conversion rate of 1%. Two of the three conversions were a result of a major vascular complication (0.6%). The first major vascular complication resulted from an endovascular stapler malfunction during transection of an accessory left renal artery. The second vascular complication was a Veress needle injury to the left common iliac artery. Three postoperative major complications (1%) occurred, including 1 case of rhabdomyolysis and 2 cases of chylous ascites. Also, 7 minor postoperative complications (2.3%) occurred. Our overall complication rate was 4%. No patients died, and the mean hospital stay was 1.1 days.

CONCLUSIONS

Our results have shown that LLDN is a safe procedure associated with low morbidity and a quick recovery. Appropriate patient selection is essential to ensure the safety of this procedure.

The 22q11 deletion syndrome candidate gene Tbx1 determines thyroid size and positioning

Thyroid dysgenesis is the major cause of congenital hypothyroidism in humans. The underlying molecular mechanism is in most cases unknown, but the frequent co-incidence of cardiac anomalies suggests that the thyroid morphogenetic process may depend on proper cardiovascular development. The T-box transcription factor TBX1, which is the most probable gene for the 22q11 deletion syndrome (22q11DS/DiGeorge syndrome/velo-cardio-facial syndrome), has emerged as a central player in the coordinated formation of organs and tissues derived from the pharyngeal apparatus and the adjacent secondary heart field from which the cardiac outflow tract derives. Here, we show that Tbx1 impacts greatly on the developing thyroid gland, although it cannot be detected in the thyroid primordium at any embryonic stage. Specifically, in Tbx1-/- mice, the downward translocation of Titf1/Nkx2.1-expressing thyroid progenitor cells is much delayed. In late mutant embryos, the thyroid fails to form symmetric lobes but persists as a single mass approximately one-fourth of the normal size. The hypoplastic gland mostly attains a unilateral position resembling thyroid hemiagenesis. The data further suggest that failure of the thyroid primordium to re-establish contact with the aortic sac is a key abnormality preventing normal growth of the midline anlage along the third pharyngeal arch arteries. In normal development, this interaction may be facilitated by Tbx1-expressing mesenchyme filling the gap between the pharyngeal endoderm and the detached thyroid primordium. The findings indicate that Tbx1 regulates intermediate steps of thyroid development by a non-cell-autonomous mechanism. Thyroid dysgenesis related to Tbx1 inactivation may explain an overrepresentation of hypothyroidism occurring in patients with the 22q11DS.

[Comparison of IgA/VCA, IgA/EA, IgG/EA in immunoenzyme methods and ZEBRA ELISA in early diagnosis of nasopharyngeal carcinoma.]

BACKGROUND

To develop an ELISA method using Herpesvirus hominis type 4 (EBV) IgG/Zebra as capture antigen for large population screening.

METHODS

The ELISA method used purified ZEBRA antigen to detect the IgG/ZEBRA antibody from serum in nasopharyngeal carcinoma (NPC) and normal healthy subjects.

RESULTS

Of 288 NPC sera, 262 were detected positive, the sensitivity was 91%, while 5 of 96 normal sera were detected positive, the specificity was 94.8% and the results of NPC group and healthy group displayed significant difference (P less than 0.001). IgA/VCA, IgA/EA, IgG/EA in immunoenzyme methods and ZEBRA ELISA were compared during the NPC screening in two cities: Huizhou, Guangdong and Guiping, Guangxi, 5463 and 2017 samples respectively were tested and 5 earlier NPC patients were found.

CONCLUSION

The results indicate that this method has high specificity and sensitivity, and can be used for large population screening to assist early phase NPC diagnosis.

Development of a xenogeneic DNA vaccine program for canine malignant melanoma at the Animal Medical Center

INTRODUCTION

Canine malignant melanoma (CMM) is an aggressive neoplasm treated with surgery and/or fractionated RT; however, metastatic disease is common and chemoresistant. Preclinical and clinical studies by our laboratory and others have shown that xenogeneic DNA vaccination with tyrosinase family members can produce immune responses resulting in tumor rejection or protection and prolongation of survival. These studies provided the impetus for development of a xenogeneic DNA vaccine program in CMM.

MATERIALS AND METHODS

Cohorts of three dogs each received increasing doses of xenogeneic plasmid DNA encoding either human tyrosinase (huTyr; 100/500/1500 mcg), murine GP75 (muGP75; 100/500/1500 mcg), murine tyrosinase (muTyr; 5 dogs each at 100/500 mcg), muTyr+/-HuGM-CSF (9 dogs at 50 mcg muTyr, 3 dogs each at 100/400/800 mcg HuGM-CSF, or 3 dogs each at 50 mcg muTyr with 100/400/800 mcg HuGM-CSF), or 50 mcg MuTyr intramuscularly biweekly for a total of four vaccinations.

RESULTS

The Kaplan-Meier median survival time (KM MST) for all stage II-IV dogs treated with huTyr, muGP75 and muTyr are 389, 153 and 224 days, respectively. Preliminarily, the KM MST for stage II-IV dogs treated with 50 mcg MuTyr, 100/400/800 mcg HuGM-CSF or combination MuTyr/HuGM-CSF are 242, 148 and >402 (median not reached) days, respectively. Thirty-three stage II-III dogs with loco-regionally controlled CMM across the xenogeneic vaccine studies have a KM MST of 569 days. Minimal to mild pain was noted on vaccination and one dog experienced vitiligo. We have recently investigated antibody responses in dogs vaccinated with HuTyr and found 2- to 5-fold increases in circulating antibodies to human tyrosinase.

CONCLUSIONS

The results of these trials demonstrate that xenogeneic DNA vaccination in CMM: (1) is safe, (2) leads to the development of anti-tyrosinase antibodies, (3) is potentially therapeutic, and (4) is an attractive candidate for further evaluation in an adjuvant, minimal residual disease Phase II setting for CMM.

Use of traditional drugs in a hospital of Chinese medicine in Germany

The frequency of use of traditional Chinese drugs was investigated in relation to Western and Chinese diagnostic classifications in a hospital for traditional Chinese medicine in Germany. All 1597 in-patients treated in the hospital between February 1992 and August 1993 entered a prospective observational study. About two thirds of the patients suffered from chronic pain syndromes, the most frequent single diagnosis being migraine (n=244). All patients were treated with at least one of four Chinese therapies (traditional Chinese drugs, acupuncture, Tuina-massage, Qi-gong). 95.1% of all patients received traditional Chinese drug treatment, prescribed in complex prescriptions including 3 to 12 single drugs from a total of 305. Drug patterns prescribed to patients with the same Western diagnosis tended to be similar, but could differ strongly for single drugs in subgroups with distinct Chinese diagnoses. Studies evaluating traditional Chinese treatment strategies in patients classified according to Western nosology should take into account possible diagnostic differences according to Chinese nosology. The development of a reliable coding system for Chinese diagnostic classifications is a precondition for further cross-cultural studies.

Use of traditional drugs in a hospital of Chinese medicine in Germany

The frequency of use of traditional Chinese drugs was investigated in relation to Western and Chinese diagnostic classifications in a hospital for traditional Chinese medicine in Germany. All 1597 in-patients treated in the hospital between February 1992 and August 1993 entered a prospective observational study. About two thirds of the patients suffered from chronic pain syndromes, the most frequent single diagnosis being migraine (n=244). All patients were treated with at least one of four Chinese therapies (traditional Chinese drugs, acupuncture, Tuina-massage, Qi-gong). 95.1% of all patients received traditional Chinese drug treatment, prescribed in complex prescriptions including 3 to 12 single drugs from a total of 305. Drug patterns prescribed to patients with the same Western diagnosis tended to be similar, but could differ strongly for single drugs in subgroups with distinct Chinese diagnoses. Studies evaluating traditional Chinese treatment strategies in patients classified according to Western nosology should take into account possible diagnostic differences according to Chinese nosology. The development of a reliable coding system for Chinese diagnostic classifications is a precondition for further cross-cultural studies.

Induction of hypoxic root metabolism results from physical limitations in O2 bioavailability in microgravity

Numerous spaceflight experiments have noted changes in the roots that are consistent with hypoxia in the root zone. These observations include general ultrastructure analysis and biochemical measurements to direct measurements of stress specific enzymes. In experiments that have monitored alcohol dehydrogenase (ADH), the data shows this hypoxically responsive gene is induced and is associated with increased ADH activity in microgravity. These changes in ADH could be induced either by spaceflight hypoxia resulting from inhibition of gravity mediated O2 transport, or by a non-specific stress response due to inhibition of gravisensing. We tested these hypotheses in a series of two experiments. The objective of the first experiment was to determine if physical changes in gravity-mediated O2 transport can be directly measured, while the second series of experiments tested whether disruption of gravisensing can induce a non-specific ADH response. To directly measure O2 bioavailability as a function of gravity, we designed a sensor that mimics metabolic oxygen consumption in the rhizosphere. Because of these criteria, the sensor is sensitive to any changes in root O2 bioavailability that may occur in microgravity. In a KC-135 experiment, the sensor was implanted in a moist granular clay media and exposed to microgravity during parabolic flight. The resulting data indicated that root O2 bioavailability decreased in phase with gravity. In experiments that tested for non-specific induction of ADH, we compared the response of transgenic Arabidopsis plants (ADH promoted GUS marker gene) exposed to clinostat, control, and waterlogged conditions. The plants were grown on agar slats in a growth chamber before being exposed to the experimental treatments. The plants were stained for GUS activity localization, and subjected to biochemical tests for ADH, and GUS enzyme activity. These tests showed that the waterlogging treatment induced significant increases in GUS and ADH enzyme activities, while the control and clinostat treatments showed no response. This work demonstrates: (1) the inhibition of gravity-driven convective transport can reduce the O2 bioavailability to the root tip, and (2) the perturbation of gravisensing by clinostat rotation does not induce a nonspecific stress response involving ADH. Together these experiments support the microgravity convection inhibition model for explaining changes in root metabolism during spaceflight.

Acupuncture versus placebo versus sumatriptan for early treatment of migraine attacks: a randomized controlled trial

OBJECTIVES

To investigate whether acupuncture is superior to placebo and equivalent to sumatriptan for the early treatment of an acute migraine attack.

DESIGN

Randomized, partly double-blind (sumatriptan versus placebo) trial.

SETTING

Two hospitals in Germany (one specialized in traditional Chinese medicine and one in the treatment of headache).

SUBJECTS

A total of 179 migraineurs experiencing the first symptoms of a developing migraine attack.

INTERVENTIONS

Traditional Chinese acupuncture, sumatriptan (6 mg subcutaneously) or placebo injection.

MAIN OUTCOME MEASURE

Number of patients in whom a full migraine attack (defined as severe migraine headache) within 48 h was prevented. In patients who developed a migraine attack in spite of early treatment, acupuncture and sumatriptan were applied a second time, whilst patients initially randomized to placebo received sumatriptan.

RESULTS

A full migraine attack was prevented in 21 of 60 (35%) patients receiving acupuncture, 21 of 58 (36%) patients receiving sumatriptan and 11 of 61 (18%) patients receiving placebo (relative risk of having a full attack 0.79 (95% CI, 0.64-0.99) for acupuncture versus placebo, and 0.78 (95% CI, 0.62-0.98) for sumatriptan versus placebo). Response to the second intervention in patients who developed a full attack was better with sumatriptan (17/31 patients who received sumatriptan twice and 37/46 patients who had had placebo first) than with acupuncture (4/31). The number of patients reporting side-effects was 14 in the acupuncture group, 23 in the sumatriptan group and 10 in the placebo group.

CONCLUSIONS

In this trial acupuncture and sumatriptan were more effective than a placebo injection in the early treatment of an acute migraine attack. When an attack could not be prevented, sumatriptan was more effective than acupuncture at relieving headache.

Mice overexpressing genes from the 22q11 region deleted in velo-cardio-facial syndrome/DiGeorge syndrome have middle and inner ear defects

Velo-cardio-facial syndrome/DiGeorge syndrome (VCFS/DGS) is a congenital anomaly disorder associated with hemizygous 22q11 deletions. We previously showed that bacterial artificial chromosome (BAC) transgenic mice overexpressing four transgenes, PNUTL1, (CDCrel-1), GP1B beta, TBX1 and WDR14, had reduced viability, cardiovascular malformations and thymus gland hypoplasia. Since these are hallmark features of VCFS/DGS, we analyzed the mice for additional anomalies. We found that the mice have important defects in the middle and inner ear that are directly relevant to the disorder. The most striking defect was the presence of chronic otitis media, a common finding in VCFS/DGS patients. In addition, the mice had a hyperactive circling behavior and sensorineural hearing loss. This was associated with middle and inner ear malformations, analogous to Mondini dysplasia in humans reported to occur in VCFS/DGS patients. We propose that overexpression of one or more of the transgenes is responsible for the etiology of the ear defects in the mice. Based upon its pattern of expression in the ear and functional studies of the gene, TbX1 likely plays a central role. Haploinsufficiency of TBX1 may be responsible for ear disorders in VCFS/DGS patients.

Effect of steroid-liposome on immunohistopathology of IgA nephropathy in ddY mice

Immunopathological studies were performed to determine whether glomerular injuries in ddY mice, a spontaneous animal model for IgA nephropathy, are influenced by treatment with a newly developed liposome loaded with prednisolone phosphate (PSL-liposome). The newly synthesized novel cationic lipid 3,6-dipentadeciroxy-1-amizino-benzene (TRX-20) was employed to obtain selective affinity to the anionic cell surface and extracellular matrices in glomerular mesangial lesions. ddY mice were treated intravenously with 1.0 mg/kg of PSL-liposome once a week for 16 weeks (from 45 weeks to 61 weeks of age). ddY mice were also intravenously treated with 1.0 mg/kg of ordinary PSL once a week for the same duration. On immunofluorescence, depositions of IgA and C3 in the glomerular mesangial areas and capillary walls of PSL-liposome-treated ddY mice were markedly decreased as compared with those of ordinary PSL-treated and untreated control ddY mice. The mean intensity of IgA and C3 in glomeruli of PSL-liposome-treated ddY mice was decreased as compared with that in ordinary PSL-treated and untreated control ddY mice. Glomerular mesangial expansion in PSL-liposome-treated ddY mice was milder than that found in ordinary PSL-treated ddY mice or untreated control ddY mice. It appears that treatment with PSL-liposome is effective in improving glomerular IgA and C3 depositions and glomerular expansion in IgA nephropathy of ddY mice.

DNA hypermethylation is a mechanism for loss of expression of the HLA class I genes in human esophageal squamous cell carcinomas

The three human leukocyte antigen (HLA) class I antigens, HLA-A, HLA-B and HLA-C, play important roles in the elimination of transformed cells by cytotoxic T cells. Frequent loss of expression of these antigens at the cell surface has been observed in many human cancers. Various mechanisms for post-transcriptional regulation have been proposed and tested but the molecular mechanisms for transcriptional regulation are not clear. We show by immunohistochemistry that the HLA class I antigens are absent in 26 of 29 (89%) samples of human esophageal squamous cell carcinomas (ESCC). Eleven of the 26 ESCC samples lost mRNA expression for at least one of the HLA genes, as shown by RT-PCR. DNA from the 29 pairs of ESCC and neighboring normal epithelium were examined for CpG island hypermethylation, homozygous deletion, microsatellite instability (MSI) and loss of heterozygosity (LOH). DNA from normal epithelial tissues had no detectable methylation of the CpG islands of any of these gene loci. Thirteen of 29 ESCC samples (45%) exhibited methylation of one or more of the three HLA loci and six samples (21%) exhibited methylation of all three loci. The HLA-B gene locus was most frequently methylated (38%). HLA-B mRNA expression in an ESCC cell line, where HLA-B was hypermethylated and did not express mRNA, was activated after treatment with 5-aza-2'-deoxycytidine. Homozygous deletion of these three gene loci was not observed. Relatively low rates of LOH and MSI were observed for the microsatellite markers D6S306, D6S258, D6S273 and D6S1666, close to the HLA-A, -B and -C loci, although a high ratio of LOH was observed at a nearby locus (represented by the markers D6S1051 and D6S1560), where the tumor suppressor gene p21(Waf1) resides. A strong correlation between genetic alterations and mRNA inactivation was observed in the ESCC samples. Our results indicate that HLA class I gene expression was frequently down-regulated in ESCC at both the protein and mRNA levels and that hypermethylation of the promoter regions of the HLA-A, -B and -C genes is a major mechanism of transcriptional inactivation.

[Antisense RNA for urokinase receptor inhibits the invasiveness and metastasis of lung carcinoma]

OBJECTIVE

To inhibit invasion and metastasis of human lung carcinoma cell line 95D by antisense RNA for urokinase receptor (uPAR).

METHODS

Antisense RNA expression plasmid for uPAR was introduced into the highly metastatic human lung carcinoma cells 95D. Modified Boyden's chamber was used to detect the invasion ability, and nude mice were used to determine metastasis.

RESULTS

Two transfected clones were found to integrate the antisense expression plasmid into genomic DNA and to express antisense RNA for uPAR. Antisense RNA blocked the uPAR expression in the transfected clones. The evident reductions of the invasiveness of antisense clones were observed by comparison with control cells, 95D cells and cells transfected with pcDNA3 vector. The metastatic potential of these two antisense clones decreased significantly in comparison with the controls (P < 0.05).

CONCLUSIONS

The results suggest that antisense RNA for uPAR inhibits uPAR expression and leads to a decrease of metastatic potential of 95D cells. Antisense RNA technique may have a valuable application in anti-metastatic therapy of human lung carcinoma.

Escherichia coli poly(A)-binding proteins that interact with components of degradosomes or impede RNA decay mediated by polynucleotide phosphorylase and RNase E

The multifunctional ribonuclease RNase E and the 3'-exonuclease polynucleotide phosphorylase (PNPase) are major components of an Escherichia coli ribonucleolytic "machine" that has been termed the RNA degradosome. Previous work has shown that poly(A) additions to the 3' ends of RNA substrates affect RNA degradation by both of these enzymes. To better understand the mechanism(s) by which poly(A) tails can modulate ribonuclease action, we used selective binding in 1 m salt to identify E. coli proteins that interact at high affinity with poly(A) tracts. We report here that CspE, a member of a family of RNA-binding "cold shock" proteins, and S1, an essential component of the 30 S ribosomal subunit, are poly(A)-binding proteins that interact functionally and physically, respectively, with degradosome ribonucleases. We show that purified CspE impedes poly(A)-mediated 3' to 5' exonucleolytic decay by PNPase by interfering with its digestion through the poly(A) tail and also inhibits both internal cleavage and poly(A) tail removal by RNase E. The ribosomal protein S1, which is known to interact with sequences at the 5' ends of mRNA molecules during the initiation of translation, can bind to both RNase E and PNPase, but in contrast to CspE, did not affect the ribonucleolytic actions of these enzymes. Our findings raise the prospect that E. coli proteins that bind to poly(A) tails may link the functions of degradosomes and ribosomes.

[A clinical evaluation on reconstruction in extended partial laryngectomy for transglottic cancer]

OBJECTIVE

Transglottic cancer has been a definite indication for total laryngectomy in decades, compromising function of the larynx. The purpose of this study is to present a new radical surgery of extended partial laryngectomy and reconstruction to restore the essential function of larynx.

METHODS

Forty-one cases of transglottic cancer were treated by extended vertical laryngectomy (26/41), extended frontolateral laryngectomy (5/41) and subtotal laryngectomy (10/41); the defects of larynx were reconstructed by rotary door myocutaneous flap in twenty-seven cases, by sternohyoideus flap in seven cases, by osteomuscular flap in five cases and by sternocleidomastoid flap in two cases.

RESULTS

The 3 and 5 year survival rates were 85.7% (30/35) and 74.1% (20/27) respectively, those for stage III were 84.6% (22/26) and 76.2% (16/21), for stage IV were 3/4 and 1/2 respectively. All cases resumed acceptable voice, 92.7% (38/41) and enjoyed satisfactory phonation. The over-all decannulation rate was 87.8% (36/41), those with rotary door myocutaneous flap was 96.3% (26/27), with sternohyoideus flap was 5/7, with osteomuscular flap was 4/5 and with sternocleidomastoid flap was 1/2. All patients had normal swallow function.

CONCLUSION

Extended partial laryngectomy is a kind of radical operation in selected cases of transglottic cancer. The method of reconstruction with rotary door myocutaneous flap can improve curative effect and the essential functions of the larynx.

Constitutive association of c-N-Ras with c-Raf-1 and protein kinase C epsilon in latent signaling modules

Phorbol ester stimulation of the MAPK cascade is believed to be mediated through the protein kinase C (PKC)-dependent activation of Raf-1. Although several studies suggest that phorbol ester stimulation of MAPK is insensitive to dominant-negative Ras, a requirement for Ras in Raf-1 activation by PKC has been suggested recently. We now demonstrate that in normal, quiescent mouse fibroblasts, endogenous c-N-Ras is constitutively associated with both c-Raf-1 and PKC epsilon in a biochemically silent, but latent, signaling module. Chemical inhibition of novel PKCs blocks phorbol 12-myristate 13-acetate (PMA)-mediated activation of MAPKs. Down-regulation of PKC epsilon protein levels by antisense oligodeoxyribonucleotides blocks MAPK activation in response to PMA stimulation, demonstrating that PKC epsilon activity is required for MAPK activation by PMA. c-Raf-1 activity in immunoprecipitated c-N-Ras.c-Raf-1.PKC epsilon complexes is stimulated by PMA and is inhibited by GF109203X, thereby linking c-Raf-1 activation in this complex to PKC activation. These observations suggest that in quiescent cells Ras is organized into ordered, inactive signaling modules. Furthermore, the regulation of the MAPK cascade by both Ras and PKC is intimately linked, converging at the plasma membrane through their association with c-Raf-1.

[The effect of ischemic preconditioning on adenosine phosphate content after spinal cord ischemia in rabbits]

AIM

To study the effect of ischemic preconditioning (IP) on adenosine phosphate content after spinal cord ischemia in rabbits.

METHODS

We established a lumbar spinal cord ischemia model by inflating the balloon of a 4F Swan-Ganz catheter positioned in the abdominal aorta of the rabbits. All rabbits were divided into sham-operated group, ischemic group and IP group. Adenosine phosphate content in spinal cord of all rabbits was determined at 4 hours, 2 days and 5 days after spinal cord ischemia by using reverse phase HPLC.

RESULTS

ATP content in lumbar spinal cord of rabbits in ischemic group was markedly reduced (P < 0.01 vs sham-operated group). But in IP group, it was obviously elevated at each time point compared with ischemic group (P < 0.01).

CONCLUSION

IP can significantly elevated ATP content in postischemic lumbar spinal cord in rabbits. This may be one of the mechanisms that IP can protect spinal cord from ischemic injury.

Melanoma differentiation associated gene-7 (mda-7): a novel anti-tumor gene for cancer gene therapy

BACKGROUND

The mda-7 gene (melanoma differentiation associated gene-7) is a novel tumor suppressor gene. The anti-proliferative activity of MDA-7 has been previously reported. In this report, we analyze the anti-tumor efficacy of Ad-mda7 in a broad spectrum of cancer lines.

MATERIALS AND METHODS

Ad-mda7-transduced cancer or normal cell lines were assayed for cell proliferation (tritiated thymidine incorporation assay, Alamar blue assay, and trypan-blue exclusion assay), apoptosis (TUNEL, and Annexin V staining visualized by fluorescent microscopy or FACs analysis), and cell cycle regulation (Propidium Iodide staining and FACs analysis).

RESULTS

Ad-mda7 treatment of tumor cells resulted in growth inhibition and apoptosis in a temporal and dose-dependent manner. The anti-tumor effects were independent of the genomic status of p53, RB, p16, ras, bax, and caspase 3 in these cells. In addition, normal cell lines did not show inhibition of proliferation or apoptotic response to Ad-mda7. Moreover, Ad-mda7-transduced cancer cells secreted a soluble form of MDA-7 protein. Thus, Ad-mda7 may represent a novel gene-therapeutic agent for the treatment of a variety of cancers.

CONCLUSIONS

The potent and selective killing activity of Ad-mda7 in cancer cells but not in normal cells makes this vector a potential candidate for cancer gene therapy.

Heterologous expression of the single-mutation glucose isomerase (GIG138P) gene in Streptomyces lividans and its genetic instability

A 1.3-kb PstI-BamHI fragment containing the single-mutation glucose isomerase (GIG138P, GI1) gene and its natural promoter was inserted into PstI-BglII linearized Streptomyces vector pIJ702. The ligation mixture was then introduced into Streptomyces lividans TK54 protoplasts; transformants were identified based on their thiostrepton resistance (ThR) and insertional inactivation of the melanin phenotype; and three white colonies, XY-2, 6, and 9, harboring recombinant expression plasmid pYH703, were obtained. Enzyme assay and SDS-PAGE analysis indicated that the GI1 gene was expressed, the intracellular GI1 specific activity was 6 U/mg, and GI1 accounted for 20% of the soluble proteins in S. lividans. Restriction analysis and Southern blot of pYH703 showed the existence of plasmid deletion, presumably owing to the interaction between the mel and GI1 sequences. Continuous liquid cultures of the recombinant strain demonstrated that the GI1 specific activity and GI1 expression in S. lividans decreased, and more obviously under non-selective conditions.

A TSG101/MDM2 regulatory loop modulates MDM2 degradation and MDM2/p53 feedback control

The p53 tumor suppressor protein and the MDM2 oncoprotein form a feedback-control loop that up-regulates cellular MDM2 production, blocks p53 activity, and promotes p53 decay. tsg101 was discovered as a gene whose deficiency results in neoplastic transformation of NIH 3T3 cells and the ability to generate metastatic tumors in nude mice. Its protein product contains a domain, Ubc, characteristic of the catalytic domain of ubiquitin conjugase (E2) enzymes but lacking an active-site cysteine crucial for ubiquitin conjugase activity. Here we report that TSG101 participates with MDM2 in an autoregulatory loop that modulates the cellular levels of both proteins, and also of p53, by affecting protein decay. We show that the Ubc domain of TSG101 interferes with ubiquitination of MDM2, that TSG101 inhibits MDM2 decay and elevates its steady-state level, and that these events are associated with down-regulation of p53 protein. Conversely, pulse-chase and Western blot experiments in wild-type and mutant fibroblasts indicate that elevation of MDM2 by overexpression of wild-type p53, by amplification of the endogenous MDM2 gene, or by transfection of MDM2-expressing constructs promotes TSG101 loss, which we show occurs by 26S proteasome-dependent decay. Our results identify TSG101 as both a regulator of, and target of, MDM2/p53 circuitry.

Function of the heterocercal tail in white sturgeon: flow visualization during steady swimming and vertical maneuvering

Basal ray-finned fishes possess a heterocercal tail in which the dorsal lobe containing the extension of the vertebral column is longer than the ventral lobe. Clarifying the function of the heterocercal tail has proved elusive because of the difficulty of measuring the direction of force produced relative to body position in the aquatic medium. We measured the direction of force produced by the heterocercal tail of the white sturgeon (Acipenser transmontanus) by visualizing flow in the wake of the tail using digital particle image velocimetry (DPIV) while simultaneously recording body position and motion using high-speed video. To quantify tail function, we measured the vertical body velocity, the body angle and the path angle of the body from video recordings and the vortex ring axis angle and vortex jet angle from DPIV recordings of the wake downstream from the tail. These variables were measured for sturgeon exhibiting three swimming behaviors at 1.2 L s(−)(1), where L is total body length: rising through the water column, holding vertical position, and sinking through the water column. For vertical body velocity, body angle and path angle values, all behaviors were significantly different from one another. For vortex ring axis angle and vortex jet angle, rising and holding behavior were not significantly different from each other, but both were significantly different from sinking behavior. During steady horizontal swimming, the sturgeon tail generates a lift force relative to the path of motion but no rotational moment because the reaction force passes through the center of mass. For a rising sturgeon, the tail does not produce a lift force but causes the tail to rotate ventrally in relation to the head since the reaction force passes ventral to the center of mass. While sinking, the direction of the fluid jet produced by the tail relative to the path of motion causes a lift force to be created and causes the tail to rotate dorsally in relation to the head since the reaction force passes dorsal to the center of mass. These data provide evidence that sturgeon can actively control the direction of force produced by their tail while maneuvering through the water column because the relationship between vortex jet angle and body angle is not constant.

Effect of black and green tea polyphenols on c-jun phosphorylation and H(2)O(2) production in transformed and non-transformed human bronchial cell lines: possible mechanisms of cell growth inhibition and apoptosis induction

The biological activities of theaflavin (TF), theaflavin gallate (TFG) and theaflavin digallate (TFdiG) from black tea and (-)-epigallocatechin 3-gallate (EGCG) and (-)-epigallocatechin (EGC) from green tea were investigated using SV40-immortalized (33BES) and Ha-ras gene transformed (21BES) human bronchial epithelial cell lines. Growth inhibition and cell viability were measured by trypan blue dye exclusion assay following 24 h treatment with the tea polyphenols. TFdiG, EGC and EGCG displayed comparable inhibitory effects on the growth of 21BES cells, with estimated IC(50) values of 22-24 microM. TFG exhibited a lower inhibitory activity (IC(50) 37 microM) and TF was even less effective (IC(50) 47 microM) in this cell line. A similar effect was also observed in 33BES cells. These results suggest that the gallate structure of theaflavins is important for growth inhibition. Exposure of 21BES cells to 25 microM TFdiG, EGC and EGCG for 24 h led to induction of cell apoptosis/death as determined by the Annexin V apoptosis assay. With TFdiG treatment cell death occurred early, and quickly peaked at 8-12 h. Morphological observations showed that TFdiG-treated cells appeared irregular in shape, with cytoplasmic granules, suggesting a cytotoxic effect. On the other hand, EGC and EGCG showed a lag phase before a rapid increase in apoptosis between 16 and 24 h, without any marked morphological changes, which was similar to that induced by H(2)O(2). TFdiG, EGC and EGCG induced similar amounts of H(2)O(2) formation in 21BES cells. Exogenously added catalase significantly prevented EGC- and EGCG-induced cell apoptosis, but did not prevent TFdiG-induced cell death, suggesting that H(2)O(2) is involved in the apoptosis induced by EGCG and EGC, but not in TFdiG-induced cell death. EGCG and TFdiG were shown to decrease c-jun protein phosphorylation in 21BES cells. Such inhibition is expected to result in lowered AP-1 activity, which may contribute to the growth inhibitory activity of tea polyphenols.