miR-151a induces partial EMT by regulating E-cadherin in NSCLC cells.

miR-151a and its host gene, focal adhesion kinase, FAK, are located in a region of chromosome 8q that is frequently amplified in solid tumors, including lung cancer. Lung cancer is the leading cause of cancer deaths worldwide and metastasis remains the major challenge in battling lung cancer mortality. Here, we demonstrate that miR-151a is overexpressed in non-small cell lung cancer (NSCLC) patient specimens, as compared to healthy lung. In addition, miR-151a overexpression promotes proliferation, epithelial-to-mesenchymal transition (EMT) and induces tumor cell migration and invasion of NSCLC cells. Blocking miR-151a expression using anti-miR-151a approaches significantly reduced NCSLC cell proliferative and motility potential. Furthermore, we determined that miR-151a significantly regulates E-cadherin expression. Finally, functional rescue experiments determined that overexpression of E-cadherin in miR-151a NSCLC cell lines potently repressed miR-151a-induced partial EMT and cell migration of NSCLC cells. In conclusion, our findings suggest that miR-151a functions as an oncomiR in NSCLC by targeting E-cadherin mRNA and inducing proliferation, migration and partial EMT.

Forskolin-induced immunoreactive atrial natriuretic peptide (ANP) secretion and pro-ANP messenger ribonucleic acid expression of hypothalamic neurons in culture: modulation by glucocorticoids.

In the present studies the chronic effects of glucocorticoids and drugs activating cAMP-dependent pathways on the production and secretion of immunoreactive (ir) ANP from long term monolayer cultures of neonatal rat hypothalamic neurons were examined. Forskolin treatment increased ir-ANP release in a time-dependent and dose-related manner, with an EC50 of approximately 30 microM; at a lower dose of 10 microM, forskolin doubled ir-ANP release (P less than 0.01) compared to that in control cultures (mean +/- SEM, 9.6 +/- 0.3 pg/well; n = 4). While dexamethasone (DM) alone did not affect basal secretion of ir-ANP, 10 nM of the glucocorticoid significantly enhanced the effect of forskolin (10 microM) by raising ir-ANP release approximately 3 times that induced by forskolin alone (P less than 0.001). This potentiation of DM was both time dependent and dose responsive, with an EC50 of 1 nM; this effect was significantly suppressed by 100 nM RU38486, a glucocorticoid or type II receptor antagonist, but not by RU28318, a mineralocorticoid receptor antagonist. In addition, forskolin (10 microM) or DM (10 nM) alone significantly increased ir-ANP production approximately 1.4 times (P less than 0.05) and 1.3 times (P less than 0.05) over that of control cultures, respectively, whereas concurrent treatment with forskolin and DM increased ir-ANP production by approximately 1.8 times (P less than 0.01). These changes were reflected by a corresponding increment in the abundance of pro-ANP mRNA in the cultures, as demonstrated by Northern blot analysis. We conclude from the present findings that glucocorticoid- and cAMP-dependent pathways may modulate the function of ANP neurons in rat hypothalami by regulating the secretion and production of the neuropeptide at the genomic level.

Molecular cloning and characterization of ovine homeo-box-containing genes.

The sheep genome contains at least eleven homeo-boxes (hox). Using two hox-specific 36-mer oligodeoxynucleotides to screen a sheep genomic library, constructed in lambda Charon28, clones of nine of the hox were identified. Six of the hox clones were analysed by nucleotide sequencing, Southern-blot hybridization and Northern-blot analysis. Two of the hox appear to be cognates of the human Hu-1 (or mouse Hox 2.1) and the mouse Hox 1-3, while another is closely related to the mouse Hox 1-4. These results suggest that there is strong sequence conservation in the hox-containing genes of different mammals, and highlight the possible occurrence of an ubiquitous set of hox-containing genes in mammals. Northern-blot analysis of four sheep hox-containing genes indicates that they are all expressed during embryogenesis and that expression is temporally regulated allowing hierarchical-regulatory interaction. Interestingly, none of the cloned hox-containing sequences contain repetitive sequences.

Developmental expression of proenkephalin A mRNA and phenylethanolamine N-methyltransferase mRNA in foetal sheep adrenal medulla.

The ontogenic expression of proenkephalin A (ProEnk A) mRNA and phenylethanolamine N-methyltransferase (PNMT) mRNA was examined in the foetal sheep adrenal medulla by the use of specific oligodeoxyribonucleotide probes. Northern blot analysis of RNA extracts from foetal adrenals demonstrated that ProEnk A mRNA was expressed as early as 60 days of gestation, a time at which the foetal adrenal is not functionally innervated. In situ hybridization on sections of foetal adrenals revealed that at 110-140 days gestation ProEnk A mRNA was expressed in chromaffin cells at the outer margin of the adrenal medulla but at earlier stages of gestation (e.g. 95 days) appeared to be expressed homogeneously throughout the whole of the adrenal medulla. In comparison, PNMT mRNA was expressed preferentially in cells at the outer margin of the adrenal medulla from the earliest stage detectable. Both PNMT mRNA and ProEnk A mRNA co-localized in cells at the outer margin of foetal adrenal of late gestations (110-140 days), a similar pattern to that seen in the adult adrenal medulla. These results indicate that, as with adult animals, in foetuses of late gestation, adrenal enkephalins are co-stored within adrenaline cells. It is likely therefore that enkephalins are co-released from the foetal adrenal with adrenaline in response to intra-uterine stress.

Synthesis of a specific oligodeoxyribonucleotide probe and its use for studying proenkephalin A gene expression.

A 44-mer, complementary to the coding region of bovine adrenal medullary proenkephalin A mRNA (ProEnkA mRNA) has been synthesized as a specific probe for this mRNA. Northern-blot hybridization analysis identified a single band in an RNA extract from bovine, ovine and porcine adrenal medullae. The molecular size of these hybridized bands (1400-1600 nucleotides) was in excellent agreement with that reported previously using cloned cDNA probes. In situ hybridization on bovine and ovine adrenal sections revealed that ProEnkA mRNA was localized selectively in cells at the outer margin of the medulla, a region rich in adrenaline-containing cells. This study both confirms and extends previous findings with cloned cDNA probes on the presence of high concentrations of ProEnkA mRNA in cells at the periphery of the adrenal medulla. In addition, it demonstrates the usefulness of synthetic oligodeoxyribonucleotides as specific and sensitive probes for the study of proenkephalin A gene expression.

Biochemical and molecular analysis of sheep MHC class II molecules.

A panel of monoclonal antibodies was used for structural and immunodepletion analysis of sheep MHC class II molecules. The results indicate the antibodies recognize molecules of molecular weight 32-34,000 (alpha chain) and 26-28,000 (beta chain). Immunodepletion analysis indicates that the antibodies may recognize up to four distinct class II molecules some of which are structurally distinguishable using SDS-PAGE. Southern blot analysis using HLA-D region DR, DQ, DP, DO and DZ cDNA probes showed that a number of the cDNA probes hybridized specifically to sheep DNA indicating the presence of closely related genes in sheep. Together the results suggest that the sheep MHC class II region contains distinct MHC class II genes similar to those found in man.

Epigenetic dysregulation of Wnt signaling pathway in multiple myeloma.

Wnt signaling has recently been implicated in carcinogenesis. We studied the activity of Wnt signaling and the methylation status of WIF1, DKK3, APC, SFRP1, SFRP2, SFRP4 and SFRP5 by methylation-specific PCR in myeloma cell lines and primary myeloma samples. Of the four cell lines, Wnt signaling was constitutively activated in LP1 and WL2, correlating with hypermethylation and hence silencing. Moreover, 5-aza-2'-deoxycytidine treatment of these two cell lines showed progressive demethylation of methylated Wnt inhibitors, re-expression of transcripts and downregulation of Wnt signaling. In both LP1 and WL2 cells, multiple Wnts and Fzs were simultaneously expressed. Treatment of WL2, in which SFRP1 was completely methylated, with recombinant secreted Frizzled-related protein 1 (SFRP1) induced downregulation of Wnt signaling and inhibition of proliferation. In primary myeloma samples, 42% patients had methylation of at least one of these seven genes, of which 61.9% had > or = 2 genes methylated. In conclusion, Wnt signaling is constitutively activated in myeloma, associated with methylation silencing of one or multiple soluble Wnt antagonists. An autocrine loop regulating Wnt signaling was demonstrated in the myeloma plasma cells, in which cellular proliferation was efficiently inhibited by recombinant SFRP1. Methylation study of a panel of genes, regulating a cellular pathway instead of isolated genes, is important.

Predictors of peptic ulcer rebleeding after scheduled second endoscopy: clinical or endoscopic factors?

BACKGROUND AND STUDY AIMS: In a previous study we demonstrated the efficacy of second-look endoscopy with therapy within 16 - 24 hours after index endoscopy in reducing major recurrent peptic ulcer bleeding. In this study, we sought to identify factors that might predict further rebleeding after this scheduled second-look endoscopy. PATIENTS AND METHODS: We studied 249 patients (181 men, 68 women) with acute bleeding peptic ulcers who were treated at the United Christian Hospital, Hong Kong from 1999 to 2002 and who underwent a scheduled second endoscopy. Those patients who developed rebleeding after the second endoscopy were evaluated, and possible predictive factors for rebleeding were analyzed using a logistic regression model. RESULTS: Of the 249 patients who underwent scheduled second-look endoscopy, 17 patients (6.8 %) developed rebleeding: seven of these patients were treated by another endoscopic therapy; ten patients required surgery. The overall mortality rate was 3.1 %. A logistic regression analysis performed on the possible predictive factors for rebleeding found that the following factors were associated with a significant risk of further rebleeding after scheduled second endoscopy: American Society of Anesthesiologists (ASA) grade III or grade IV status (odds ratio 3.81, 95 % CI 1.27 - 11.44), ulcer size greater than 1.0 cm (odds ratio 4.69, 95 % CI 1.60 - 13.80), and a finding of persistent stigmata of recent hemorrhage at the scheduled second endoscopy (odds ratio 6.65, 95 % CI 2.11 - 20.98). CONCLUSIONS: Endoscopic factors, including large ulcer size and the persistence of endoscopic stigmata of recent hemorrhage are important predictors for recurrent bleeding after scheduled second endoscopy.

An investigation into the use of the FDI tooth notation system by dental schools in the UK.

This study investigated the use of the FDI tooth notation system in UK dental schools. In addition, the notation system used by dentists referring patients to Manchester Dental Hospital was recorded. A questionnaire was sent to the Deans of all Dental Schools in the UK and letters of referral to Manchester Dental Hospitals Paediatric GA Service were monitored for 1 month. The results showed that only Manchester University Dental School used the FDI system but 6 other schools instructed students in its use. The Palmer system was used by all the other schools for recording clinical information. 136 referral letters were received, only one used the FDI notation, 15 used both FDI and Palmer and the remainder (120) requested extractions using the Palmer notation. The FDI notation system is not used in the majority of UK dental schools. Despite the fact the Dental School in Manchester has been teaching and using the FDI system for over 10 years, it has not been adopted by General Dental Practitioners referring patients into the hospital. The FDI should review the use of their system in other countries, to ascertain whether it has fulfilled its role as an international notation system.

Genetic organization of the ovine MHC class II region.

To study the class II genes of the major histocompatibility region of the sheep genome, human HLA class II genes corresponding to the known subregions in man (DR, DQ, DP, DO, and DZ) were used for Southern hybridization analysis of sheep DNA and to probe a sheep genomic library. Hybridizing bands were noted for all probes except DP alpha. DQ alpha and beta and DR beta appear to be present as multicopy genes, while DR alpha-, DZ alpha-, and DO beta- like genes appear to be single copy. All bands detected with the DP beta probe were also detectable with other beta chain probes. From eight lambda-bacteriophage clones of a sheep genomic library nine distinct class II genes were identified. These genes were characterized by differential hybridization analysis and restriction mapping. Two genes were DR beta-like, three DQ alpha-like and four DQ beta-like. The extensive cross-hybridization observed with beta chain probes was not seen with alpha chain probes. The results of this study suggest that the major histocompatibility complex class II region of the sheep has a similar genetic organization to that of man, with the provisional exception of the DP subregion.

Laser therapy for multiple biliary papillomatosis via choledochoscopy.

BACKGROUND: Multiple biliary papillomatosis is a rare tumour of the biliary tract but is capable of multicentric malignant transformation. The complete removal of these tumours is difficult because it involves a field change of the biliary tract. METHODS: Exploration with choledochoscopy is a prerequisite for thorough assessment of the extent of involvement. Incorporation of laser ablation via a laser-delivering fibre with choledochoscopy permits complete removal of the tumour. RESULTS: Repeated laser therapy via choledochoscopy through the T-tube tract enables complete ablation of the tumour which changes the outlook of the prognosis. This is confirmed on subsequent cholangiography. CONCLUSIONS: Laser therapy via choledochoscopy is a satisfactory mode of treatment for multiple biliary papillomatosis. It enables complete and precise ablation of the tumour which certainly changes the prognosis of this condition.

Skin metastasis from nasopharyngeal carcinoma in four Chinese patients.

Nasopharyngeal carcinoma (NPC) is a common malignancy among southern Chinese. The tumours are mostly undifferentiated carcinomas and are associated with Epstein-Barr virus. Patients present with a blood-stained postnasal discharge, impaired hearing, tinnitus or cervical lymph node enlargement. Radiotherapy with or without chemotherapy is the standard treatment. Though metastatic lung, bone or liver disease is not uncommon on relapse, skin metastasis is rarely reported. The small number of reports in the literature are either brief or have only a few patients. In this report, we describe our series of four Hong Kong Chinese patients with NPC who had distant cutaneous metastases.

Characterisation of Tn501, a transposon determining resistance to mercuric ions.

The transposon encoding resistance to mercuric ions, Tn501, is 5.2 (+/-0.1) x 10(6) daltons and is bounded by small inverted repeats. The restriction sites for the restriction endonucleases EcoRI, HindIII and SalGI have been mapped on the element.

Nucleotide sequences at the ends of the mercury resistance transposon, Tn501.

The nucleotide sequences at the ends of the mercury-resistance transposon, Tn501, have been determined. The terminal sequences are inverted repeated sequences 38 nucleotide pairs in length, which differ in 3 nucleotide pairs. The transposon is flanked by directly repeated sequences of 5 nucleotide pairs, originating from a single pentanucleotide sequence in the recipient replicon. There is no obvious homology between recipient replicons at the site of insertion of the transposon. The structures of the ends of Tn501 are compared with those of other transposons and insertion sequences. The use of Tn501 to locate an EcoRI site within a genetically defined sequence of interest is discussed.

Clinicopathological features and prognostic factors of cutaneous melanoma among Hong Kong Chinese.

Cutaneous melanoma is rare among Chinese people. The clinicopathologic features and prognostic factors of 63 Hong Kong ethnic Chinese cases were analysed. We found that the mean age of onset was 65.5 years with a female : male ratio of 1 : 1.33. Forty-two (66.7%) patients had their tumours on their feet. More than 50% had the acral lentiginous histologic subtype. The mean tumour thickness was 5.73 mm with 92.1% (n = 58) having a Clark's level of III or more. Of the tumours, 57.1% were ulcerated. Stage I and II tumours comprised 73% (n = 46) while stage III and IV tumours made up of 26% (n = 17). The 1-, 3- and 5-year survival rates were 75%, 30% and 17%, respectively. Univariate analysis for overall survival showed that advanced clinical staging (stage III and IV), tumour ulceration and thicker tumour (>4 mm) had a significantly poorer prognosis. Multivariate analysis demonstrated that advanced clinical staging was the most decisive prognostic factor followed by tumour ulceration. Our study showed that cutaneous melanoma in Chinese people is a disease predominantly of an older age group with the acral lentiginous histologic type located mainly on the feet. The prognosis depends on clinical staging and ulceration status.

Anal and perianal tuberculosis: a report of three cases in 10 years.

From the computerized pathology record, three cases of anal and perianal tuberculosis were encountered in the Prince of Wales Hospital, Hong Kong during the last 10 years. The clinical history, examination findings and relevant investigations were reviewed retrospectively. Comparison was made with previous literature. Emphasis was put on the diversity of clinical presentations including acute perianal abscess, chronic anal ulcer and fistula in ano. It is concluded that a high index of suspicion is important to ensure an early diagnosis.

Co-localization of RNAs coding for phenylethanolamine N-methyltransferase and proenkephalin A in bovine and ovine adrenals.

A 29-mer oligodeoxyribonucleotide probe, complementary to the coding region of bovine phenylethanolamine N-methyltransferase (PNMT) mRNA was synthesized. Characterization of this probe by Northern blot hybridization showed that it hybridized to a single band in RNA extracted from bovine and ovine adrenal medullae. The molecular size of this hybridized band was approximately 1.0-1.2 kb which is consistent with recently reported data on the molecular weight of bovine PNMT mRNA. In situ hybridization histochemistry was carried out with this probe on bovine and ovine adrenal sections and results compared on adjacent sections with a probe against proenkephalin A (ProEnk A) mRNA synthesized previously. Both showed a similar localization to the outer margin of cells in the adrenal medulla. The results of this study provide strong evidence at the level of mRNA expression that ProEnk A mRNA is expressed preferentially in the adrenaline synthesizing cells within the adrenal medulla. Further, it demonstrates the usefulness of a synthetic oligodeoxyribonucleotide probe for the study of PNMT gene expression.

Diagnosis of Helicobacter pylori infection after gastric surgery for peptic ulcer: is the rapid urease test useful?

BACKGROUND: The usefulness of the rapid urease test (RUT) in diagnosing Helicobacter pylori infection after peptic ulcer surgery is unknown. METHODS: Patients who had undergone peptic ulcer surgery were offered endoscopic examination if they presented with dyspepsia or gastrointestinal bleeding. Biopsy specimens were taken for RUT and histology from the corpus and the stoma in patients who had undergone partial gastrectomy or from the corpus and the antrum in patients who had undergone vagotomy. Histologic examination using haematoxylin and eosin stain and Warthin-Starry stain were used as the gold standard. RESULTS: Ninety patients were studied (69 had partial gastrectomy and 21 had vagotomy). Forty-three patients (32 in the partial gastrectomy group and 11 in the vagotomy group) were positive for H. pylori by histology. The respective sensitivity of RUT was 59% (stoma) and 75% (corpus) in the partial gastrectomy group (P = 0.36) and 55% (antrum) and 73% (corpus) in the vagotomy group (P = 0.51). CONCLUSIONS: RUT is not sensitive for detecting H. pylori after acid reduction surgery.

Salt-thermal zeolitization of fly ash.

The molten-salt method has been recently proposed as a new approach to zeolitization of fly ash. Unlike the hydrothermal method, this method employs salt mixtures as the reaction medium without any addition of water. In this study, systematic investigation has been conducted on zeolitization of fly ash in a NaOH-NaNO3 system in order to elucidate the mechanism of zeolite formation and to achieve its optimization. Zeolitization of fly ash was conducted by thermally treating a powder mixture of fly ash, NaOH, and NaNO3. Zeolitization of fly ash took place above 200 degrees C, a temperature lower than the melting points of salt and base in the NaOH-NaNO3 system. However, it was uncertain whether the reactions took place in a local molten state or in a solid state. Therefore, the proposed method is renamed the "salt-thermal" method rather than the "molten-salt" method. Mainly because of difficulty in mobility of components in salt mixtures, zeolitization seems to occur within a local reaction system. In situ rearrangement of activated components seems to lead to zeolite formation. Particle growth, rather than crystal growth through agglomeration, resulted in no distinct morphologies of zeolite phases. Following are the optimal zeolitization conditions of the salt-thermal method: temperature, 250-350 degrees C; time, 3-12 h; weight ratio of NaOH/NaNO3, 0.3-0.5; weight ratio of NaNO3/fly ash, 0.7-1.4. Therefore, it is clear from this work that the salt-thermal method could be applied to massive zeolitization of fly ash as a new alternative method for recycling this waste.