Integrated clinical coding in urology – a novel way of working

Objectives:

The objective of this article is to report a completed cycle of audit of coding co-morbidities for bladder outlet surgery. We also present a novel way of working to achieve better accuracy in capturing admitted patient care data and coding in urology.

Materials and methods:

We undertook a retrospective case note and coding review of all bladder outlet surgeries performed in a single month. After initiating several measures to improve data recording and capture, we re-audited our results prospectively and analysed the results.

Results:

The initial accuracy of coding co-morbidities was 73%. This improved to 100% at re-audit. However, we found that procedure coding errors remained. We have devised a novel working model to improve all coding issues related to urology.

Conclusion:

It is possible to improve accuracy of coding by educating clinicians working alongside our integrated model of a team of a clinician with an interest in coding with coding and finance personnel.

Recurrent Perianal Sinus in Young Girl Due To Pre-sacral Epidermoid Cyst

Pre-sacral epidermoid cysts are rare development cysts resulting from dysembryogenesis mostly diagnosed in middle aged women. We report a case of pre-sacral epidermoid cyst presenting with recurrent perianal sinus in young girl. Generally pre-sacral epidermoid cysts are seen in adult age group but it is rare presentation in young age group. We report a rare case of presacral epidermoid cyst occurring in a young female.

A single injection of kisspeptin-54 temporarily increases luteinizing hormone pulsatility in healthy women

BACKGROUND

Kisspeptin is a novel hypothalamic peptide which stimulates endogenous gonadotrophin releasing hormone (GnRH) secretion. A single subcutaneous bolus injection of kisspeptin-54 increases circulating luteinizing hormone (LH) levels in women, but its acute effects on LH pulsatility are not known.

AIMS

To investigate the effects of a single subcutaneous (sc) injection of kisspeptin-54 administration on LH pulsatility in healthy female volunteers.

METHODS

Six healthy female adult volunteers underwent 10-minute blood sampling for serum LH measurement for 8 h during the follicular phase of menstrual cycle. Sc bolus injection of saline or kisspeptin-54 (0·15, 0·30 or 0·60 nmol/kg) was administered 4 h after commencing the study. A previously described, blinded deconvolution method was used to detect LH pulses.

RESULTS

Mean number of LH pulses was increased significantly following 0·30 and 0·60 nmol/kg kisspeptin-54 when compared with saline (mean increase in number of LH pulses per 4 h, following injection: -0·17 ± 0·54, saline; +2·33 ± 0·56, 0·30 nmol/kg kisspeptin-54, P < 0·05 vs saline; +2·33 ± 0·80, 0·60 nmol/kg kisspeptin-54, P < 0·05 vs saline). LH pulse secretory mass increased following injection of 0·60 nmol/kg in five of six subjects, but the mean change in all subjects was non-significant when compared with saline (mean increase in pulse secretory mass in IU/l following injection: +0·35 ± 0·40, saline; +2·61 ± 1·17, 0·60 nmol/kg kisspeptin-54, P = 0·10 vs saline).

CONCLUSIONS

A single injection of kisspeptin-54 temporarily stimulates the number of LH pulses in healthy women. Further studies are required to investigate the therapeutic potential of kisspeptin-54 injection to restore LH pulsatility in patients with reproductive disorders caused by impaired GnRH secretion.

Design and performance of an ultra-high vacuum scanning tunneling microscope operating at dilution refrigerator temperatures and high magnetic fields

We describe the construction and performance of a scanning tunneling microscope capable of taking maps of the tunneling density of states with sub-atomic spatial resolution at dilution refrigerator temperatures and high (14 T) magnetic fields. The fully ultra-high vacuum system features visual access to a two-sample microscope stage at the end of a bottom-loading dilution refrigerator, which facilitates the transfer of in situ prepared tips and samples. The two-sample stage enables location of the best area of the sample under study and extends the experiment lifetime. The successful thermal anchoring of the microscope, described in detail, is confirmed through a base temperature reading of 20 mK, along with a measured electron temperature of 250 mK. Atomically resolved images, along with complementary vibration measurements, are presented to confirm the effectiveness of the vibration isolation scheme in this instrument. Finally, we demonstrate that the microscope is capable of the same level of performance as typical machines with more modest refrigeration by measuring spectroscopic maps at base temperature both at zero field and in an applied magnetic field.

Metallic sewing needle ingestion presenting as acute abdomen

We reported an unusual case of a 26-year-old man presenting to surgical emergency as generalized peritonitis following an ingestion of multiple metallic sewing needles. The X-ray of his abdomen showed pneumoperitoneum and multiple metallic foreign bodies in the abdominal cavity. An ultrasonogram of his abdomen showed multiple metallic foreign bodies in the abdominal cavity and urinary bladder. Emergency exploratory laparotomy was performed. On laparotomy, gastric and duodenal perforation was found through which metallic sewing needles were protruding out. A peritoneal lavage was done, and all the sewing needles were extracted from the perforation site, paracolic gutter, liver parenchyma, and urinary bladder. The primary repair of the perforation with omental patching was done with the drainage of subhepatic space and pelvic cavity. These multiple ingested sewing needles led to the perforation of the stomach and the duodenum, which resulted in perforation peritonitis.

Vitamin C Modulation of Cisplatin-Induced Cytogenotoxicity in Bone Marrow, Spermatogonia and its Transmission in the Male Germline of Swiss Mice

Relative modulatory effects of three different doses of vitamin C (VC), 10, 20 and 40 mg/kg, on cytogenotoxicity induced by cisplatin (CP) 5 mg/kg were assessed from the comparison of chromosomal aberrations (CAs) and mitotic index in bone marrow cells, micronucleus test (MNT) in polychromatic erythrocytes from the somatic cell line and spermatogonial chromosome aberrations (SCAs), primary spermatocytic chromosome analysis and sperm morphology assay from the male germline of VC-pretreated and CP-alone treated mice. Each pretreatment dose of VC protected bone marrow cells from the CP-induced cytogenotoxicity by decreasing the aberrant metaphases, CAs and MN significantly, particularly the lower doses. The protection was inversely proportional to the pretreated dose of VC i.e., the higher the dose of VC the less protection was provided. The lower doses of VC also protected the spermatogonial cells by significantly decreasing the CP-induced aberrant metaphases and SCAs, whereas the highest dose potentiated such effects by increasing them significantly. Besides, transmission of CP-induced cytogenotoxicity in the male germline was enhanced significantly in all VC pretreated mice, resulting in an increase in the frequency of aberrant prima ry spermatocytes and abnormal sperm. Since the spermatogonial cells with gross effects were eliminated/died, the tolerable effects stabilized in some of them were transmitted through the male germline with the consequent increase in the manifestation of aberrant primary spermatocytes and abnormal sperm. However, VC failed to decrease in the transmission of such effects. Thus, the protective action of VC was dose dependent and tissue specific. Moreover, the time of VC treatment i.e., its pre- or post-treatment to the exposure of cells to cytogenotoxic substances is important in providing protection from or potentiation of the cytogenotoxic effects.

An analysis of the factors influencing radiation dose and fluoroscopic time during renal artery stent placement

PURPOSE

To determine the factors that affect mean absorbed dose and fluoroscopic times during renal artery stent placement.

MATERIALS AND METHODS

After institutional review board approval, the HI-IQ database was queried for patients undergoing renal artery stent placement only from January 2007 to June 2010. Procedures that were performed as part of other procedures such as iliac artery stents were excluded. The HI-IQ data included fluoroscopy time (f) and radiation dose (mGy). Demographic, medical history, procedural details, and advanced preprocedural renal artery stent imaging were obtained. Variables (number of stents, average body mass index , number of stents placed per year and number of years' service of an interventional physician, pre-procedural imaging, and use of embolic protection device) were analyzed using a t test after log transformation and testing for variance with an F test.

RESULTS

A total of 134 patients (75 males, 70.6 ± 10.5 years old) underwent the placement of 177 renal artery stents (unilateral [n = 95], average stent per patient = 1.3). Mean fluoroscopy time was 15.6 minutes and mean absorbed dose to the patient was 1729 mGy. The average fluoroscopic time and absorbed dose was significantly higher with bilateral stent placement compared to unilateral placement (13.8 vs 19.7 minutes, P = .002; 1803 vs 2380 mGy, P = .03). The average fluoroscopic time was significantly higher in patients undergoing abdominal aortogram prior to renal artery selection and stent placement.

CONCLUSION

The placement of more than 1 stent with an abdominal angiogram prior to renal artery stent placement results in increased fluoroscopic time and mean absorbed dose.

Abstract B39: Methylation of BRCA2 gene promoter CpG units through ZAR2-dependent DNMT1 recruitment

BRCA2 gene expression is stringently regulated during the cell cycle. BRCA2 expression is proportional to the rate of cell proliferation. Looking at the human BRCA2 gene minimal promoter sequence we found that it has over 45 CpG units which could be potentially methylated regulating the recruitment of different transcription factors affecting BRCA2 gene expression. We discovered that BRCA2 gene promoter has bi-directional activity and the product of the reverse activity (a ZAR1-like protein, we named ZAR2) silences the forward promoter (for BRCA2). ZAR2 is a C4-type zinc finger-containing transcription factor that regulates BRCA2 in a cell cycle dependent manner. We found that ZAR2 enters the nucleus of the G0/G1 cells binds to the promoter of BRCA2 and silences the BRCA2 gene expression. ZAR2 has a dsRNA binding domain. We report here that BRCA2 gene promoter, through its bidirectional activity, produces two partially overlapping transcripts (BRCA2 and ZAR2) in the breast cells forming a 111 bp RNA duplex. We postulate that endogenous transcriptional gene silencing RNAs (tgsRNAs) against BRCA2 gene promoter are thus formed from the overlapping RNA duplex in the cell nucleus. These tgsRNAs in turn contribute towards promoter methylation. Our data suggest that ZAR2 upon binding to the tgsRNAs binds to specific locations of BRCA2 gene promoter and recruits DNMT1 which in turn perform CpG methylation. This study will contribute towards the understanding of the epigenetic regulation of BRCA2 gene expression in different cell cycle stages as well as in sporadic cases of breast and other cancer. Supported in part by the DOD-CDMRP IDEA Grants BC990678 and BC050641 to GC and MeTRC pilot project grant 1U54RR026140-01 to SM

Citation Format: Smita Misra, Mukul K. Mittal, Sheetal V. Khedkar, Gautam Chaudhuri. Methylation of BRCA2 gene promoter CpG units through ZAR2-dependent DNMT1 recruitment. [abstract]. In: Proceedings of the AACR Special Conference on Chromatin and Epigenetics in Cancer; Jun 19-22, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2013;73(13 Suppl):Abstract nr B39.

Dynamics of dark hollow Gaussian laser pulses in relativistic plasma

Optical beams with null central intensity have potential applications in the field of atom optics. The spatial and temporal evolution of a central shadow dark hollow Gaussian (DHG) relativistic laser pulse propagating in a plasma is studied in this article for first principles. A nonlinear Schrodinger-type equation is obtained for the beam spot profile and then solved numerically to investigate the pulse propagation characteristics. As series of numerical simulations are employed to trace the profile of the focused and compressed DHG laser pulse as it propagates through the plasma. The theoretical and simulation results predict that higher-order DHG pulses show smaller divergence as they propagate and, thus, lead to enhanced energy transport.

Measurements of the magnetic-field-tuned conductivity of disordered two-dimensional Mo43Ge57 and InOx superconducting films: evidence for a universal minimum superfluid response

Our measurements of the low frequency ac conductivity in strongly disordered two-dimensional films near the magnetic-field-tuned superconductor-to-insulator transition show a sudden drop in the phase stiffness of superconducting order with either increased temperature or magnetic field. Surprisingly, for two different material systems, the abrupt drop in the superfluid density in a magnetic field has the same universal value as that expected for a Berezinskii-Kosterlitz-Thouless transition in a zero magnetic field. The characteristic temperature at which phase stiffness is suddenly lost can be tuned to zero at a critical magnetic field, following a power-law behavior with a critical exponent consistent with that obtained in previous dc transport studies on the dissipative side of the transition.

Thyroid abscess: A report of six cases

Thyroid abscess is a rare clinical entity and infrequently encountered. We hereby present a review of six cases-four in the paedriatic and two in the adult age group who presented to our hospital which is a Tertiary care referral centre with thyroid abscess and the management varying from serial aspiration to incision and drainage of abscess. A brief review of literature is also included. DOI: http://dx.doi.org/10.3329/bjo.v18i2.12019 Bangladesh J Otorhinolaryngol 2012; 18(2): 207-211

Catheter thrombosis and superior/inferior vena cava syndrome are rare complications of long term parenteral nutrition

The objective of this study was to determine the incidence of catheter thrombosis and superior/inferior vena cava (SVC IVC ) syndrome in a large population of patients receiving home total parenteral nutrition (TPN), using retrospective data collection and analysis. 527 patients including 138 children who were discharged on home TPN and followed in the UCLA home TPN program for a minimum of one week between April, 1973 and October, 1991. There was a total of 1154 years of patients follow-up, including 241 years in children. Fifty-seven patients (11%) developed 81 episodes of catheter thrombosis excluding SVC IVC syndrome with an incidence of 0.07 episodes per catheter year. The median catheter duration prior to thrombosis was 7 months. Twenty-one thromboses occured in children with an incidence of 0.09 per catheter year. Eleven percent of thrombotic episodes were associated with catheter sepsis. Thirty-nine percent of patients had a PTT less than control values. Twenty-two patients including 6 children developed SVC IVC syndrome with an incidence of 0.02 per catheter year. SVC IVC syndrome was not associated with catheter sepsis in any patient. Sixty-eight percent of patients had catheter thrombosis at some point prior to developing SVC IVC syndrome. It is concluded that catheter-related thrombotic events are rare complications of home TPN and are uncommonly associated with infection. However, we recommend warfarin anticoagulation following an initial thrombotic event, in the absence of catheter malposition, for all such patients as long as they maintain a central venous catheter.

Adrenomyeloneuropathy

A 29-year-old male patient presented with progressive spastic paraparesis of three years duration. He also had gait ataxia which led to recurrent falls. In addition, there was pigmentation of the skin creases, tongue and buccal mucosa. His clinical course was remarkable by recurrent episodes of diarrhea, pulmonary tuberculosis. The investigatory work up showed a normal MRI scan of the brain, spinal cord and normal abdominal structures. The basal serum cortisol levels were low. Adrenomyeloneuropathy was diagnosed and he was started on corticosteroid supplementation. Mineralocorticoid supplementation also is planned in the follow up. The case is being presented for its rarity.

Intrauterine growth curves for singleton live babies in Paropakar Maternity and Women's Hospital in Nepal

BACKGROUND

To construct birth weight, crown heel length and head circumference centile chart referenced to gestational age for Nepalese infants.

METHODS

The study was conducted over a period of six months. It included consecutive live births from 28 to 42 weeks of gestation. Their birth weight, crown-heel length and head circumference were recorded. Smoothed percentile values along with curves were created using the Lambda Mu Sigma (LMS) method. The curves were compared with one of the Indian study.

RESULTS

A total of 9710 newborns were measured. The mean birth weight, crown-heel length, head circumference at 40 weeks were 3023g, 49.22cm and 33.61cm respectively. Smoothed percentile values calculated gave the cutoffs for defining small and large gestational age for Nepalese newborns. Comparison with Indian study showed significant difference (p<0.01) in weight. The Indian babies weighed less than Nepalese babies.

CONCLUSIONS

The referenced growth standards help in clinical assessment, defining and identifying high risk newborns, thus, leading to improved care and management of neonates. It should help public health policy makers to track population difference due to several factors, intervene and find response over time.

Abstract 1287: High mobility of triple-negative breast cancer cells is due to repression of plakoglobin gene by SLUG

One of highly pathogenic breast cancer cell types are the SLUG-high claudin-low triple negative (negative in the expression of estrogen, progesterone and ERBB2 receptors) breast cancer (TNBC) cells. These cells are highly metastatic and have low levels of the motility regulatory catenin plakoglobin. In order to link high levels of the transcriptional repressor SLUG in the TNBC cells with low levels of plakoglobin we found that SLUG inhibits the expression of plakoglobin gene directly in these cells and thus, among other downstream effects, help disseminating these tumor cells. Overexpression of SLUG in the SLUG-deficient cancer cells significantly decreased the levels of mRNA and protein of plakoglobin. On the contrary, knockdown of SLUG in SLUG-high cancer cells elevated the levels of plakoglobin. Overexpression of SLUG in the SLUG-deficient cells elevated the invasiveness and motility of these cells. On the other hand, knockdown of plakoglobin in these low motility non-invasive breast cancer cells did not affect the ability of the cancer cells to penetrate Matrigel matrix but increase the growth and migration rates of these cells. This study thus implicates high levels of SLUG and low levels of plakoglobin as determinants in the progression of highly disseminating breast cancer. Supported in parts by the DOD-CDMRP grants BC050641, BC086542 and BC103645 to GC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1287. doi:1538-7445.AM2012-1287

Abstract 2114: Trypanosoma brucei: A model to evaluate joint contribution of BRCA2 and PARP in DNA damage repair

The DNA repair protein BRCA2, initially discovered as a tumor suppressor for familial breast cancer cases, is now found to play critical role in the biology of many eukaryotes. The extracellular protozoan parasite Trypanosoma brucei significantly relies on its BRCA2 protein for stress management as well as surviving from host humoral immunity during its mammalian stage of its complex digenetic life cycle. An interesting aspect of BRCA2 deficiency in cancer cells is that these cells are ultra-sensitive to the inhibitors of the chromatin modifying enzyme poly(ADP-ribose) polymerase (PARP). In the absence of PARP, spontaneous single-strand breaks collapse replication forks and trigger homologous recombination for repair. Thus, PARP activity is essential in homologous recombination-deficient BRCA2-mutant cancer cells. BRCA2 and PARP are not only expressed in the mammalian cells but also present in high levels in many other eukaryotic cells including the parasitic protozoan T. brucei. To evaluate the universality of the importance of these two proteins in the management of DNA damage, we determined the effect of PARP inhibitors such as 3-AB, Veliparib, PF-01367338, Olaparib and Iniparib in BRCA2 knocked down T. brucei cells treated with the DNA damaging agent cisplatin. Our in vitro data strongly suggest that a combination of a BRCA2 inhibitor (e.g. BRCA2 BRC peptide), a PARP inhibitor and a DNA damaging agent (e.g. cisplatin) will be a chemical regimen for the management of trypanosomiasis and similar protozoan infections. Supported by NIH grants 2SC1GM081146-05 to MC, 1U54RR026140-01 to SM and NIH grants R01AI042327, R21AI076757 to GC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2114. doi:1538-7445.AM2012-2114

High motility of triple-negative breast cancer cells is due to repression of plakoglobin gene by metastasis modulator protein SLUG

One of highly pathogenic breast cancer cell types are the triple negative (negative in the expression of estrogen, progesterone, and ERBB2 receptors) breast cancer cells. These cells are highly motile and metastatic and are characterized by high levels of the metastasis regulator protein SLUG. Using isogenic breast cancer cell systems we have shown here that high motility of these cells is directly correlated with the levels of the SLUG in these cells. Because epithelial/mesenchymal cell motility is known to be negatively regulated by the catenin protein plakoglobin, we postulated that the transcriptional repressor protein SLUG increases the motility of the aggressive breast cancer cells through the knockdown of the transcription of the plakoglobin gene. We found that SLUG inhibits the expression of plakoglobin gene directly in these cells. Overexpression of SLUG in the SLUG-deficient cancer cells significantly decreased the levels of mRNA and protein of plakoglobin. On the contrary, knockdown of SLUG in SLUG-high cancer cells elevated the levels of plakoglobin. Blocking of SLUG function with a double-stranded DNA decoy that competes with the E2-box binding of SLUG also increased the levels of plakoglobin mRNA, protein, and promoter activity in the SLUG-high triple negative breast cancer cells. Overexpression of SLUG in the SLUG-deficient cells elevated the motility of these cells. Knockdown of plakoglobin in these low motility non-invasive breast cancer cells rearranged the actin filaments and increased the motility of these cells. Forced expression of plakoglobin in SLUG-high cells had the reverse effects on cellular motility. This study thus implicates SLUG-induced repression of plakoglobin as a motility determinant in highly disseminating breast cancer.

Abstract B36: Development of calcitrol-resistance in triple-negative breast cancer cells through SLUG-mediated coordinate repression of CYP2R1, CYP27B1, and VDR gene promoters

Metastatic breast and other cancers are often found to be refractory to vitamin D therapy. Vitamin D is synthesized from 7-dehydrocholesterol, an intermediate metaboltie in cholesterol synthesis. Ultraviolet irradiation in sunlight-exposed skin induces a photochemical reaction of 7–25-position by vitamin D 25-hydroxylase (CYP2R1), to yield 25-hydroxyvitamin D3 (cholecalciferol). Vitamin D3 is hydroxylated at the 25-position by vitamin D 25-hydroxylase (CYP2R1), to yield 25-hydroxyvitamin D3 (25(OH)D3; 25-hydroxycholecalciferol), the major form of vitamin D in the circulation. 25(OH)D3 is further hydroxylated at the 1 -position by the 25-hydroxyvitamin D 1 -hydroxylase (CYP27B1) to produce calcitrol (VD3). VD3 exhibits physiological and pharmacological effects by binding to the vitamin D receptor (VDR), a transcription factor of the nuclear receptor superfamily. Although photoactivated cholecalciferol is mainly hydroxylated in the liver and kidney, many other cells including breast cells have significant expressions of CYP2R1, CYP27B1 and VDR. Breast cells thus should be able to activate and utilize cholecalciferol if these proteins are not suppressed. We report here that the metastasis modulator protein SLUG, which is often overexpressed in metastatic triple negative breast cancer cells, coordinately repressse the levels of CYP2R1, CYP27B1 and VDR proteins in the breast cancer cells to induce vitamin D-resistance in these cells. SLUG inhibited CYP2R1, CYP27B1 and VDR gene promoter activities in these cells. ChIP assays revealed that SLUG is recruited at the CYP2R1, CYP27B1 and VDR gene promoters. Knockdown of SLUG in highly invasive MDA-MB-231 and BT549 cells increased their CYP2R1, CYP27B1 and VDR gene expression and decreased their resistance their resistance to VD3 in vitro. Our data established that SLUG regulates vitamin D metabolism and contributes to the induction of VD3-resistance in human breast cancer cells through the inhibition of CYP2R1, CYP27B1 and VDR gene promoters epigenetically through chromatin remodeling.

Supported in parts by the DOD-CDMRP grants BC050641 and BC103645.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B36.

Abstract B35: SLUG-induced plakoglobin gene repression in triplenegative breast cancer cells

Breast cancer with the triple-negative phenotype (TNBC) are ER-negative, PR-negative and ERBB2 (HER2)-negative and represent one of the most aggressive and difficult to treat subtypes of human breast cancer. TNBC is highly over-represented in African American breast cancer patients and determining the genetic and molecular basis for this incidence and the biological basis for the aggressiveness of TNBCs are largely unknown and of high priority. The transcription factor SLUG, which controls epithelial to mesenchymal transition, stem cell phenotypes and therapeutic responsiveness, is highly expressed in the basal-type TNBC cells, making it a candidate master regulator of the TNBC phenotype. Plakoglobin, also known as γ-catenin or JUP, is a member of the armadillo motifcontaining proteins. This protein is a critical component of the desmosomal structure conferring structural integrity and resistance from mechanical stress to epithelial cells in tissues. We report here that SLUG inhibits the expression of several desmosomal proteins including the plakoglobin gene directly and thus, among other downstream effects, help disseminating the TNBC cells. Overexpression of SLUG in the SLUG-deficient cancer cells significantly decreased the levels of mRNA and protein of plakoglobin. On the contrary, knockdown of SLUG in SLUG-high TNBC cells elevated the levels of plakoglobin. Inhibition of SLUG activity with a molecular decoy in the TNBC cells abrogated the inhibitory effect of SLUG on plakoglobin gene expression. Although overexpression of SLUG in the SLUG-deficient cells elevated the invasiveness and motility of these cells, knockdown of plakoglobin only affected the growth and migration rates of these cells. This study thus implicates high levels of SLUG and low levels of plakoglobin as determinants in the progression of highly disseminating breast cancer of the TNBC type.

Supported by the DOD-CDMRP BCRP Grants W81XWH-06-1-0466, W81XWH-08-1-0446, BC086542, and the Susan G. Komen Breast Cancer Foundation grant# BCTR0707627 to GC.

Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B35.

DICER1 deficit induces Alu RNA toxicity in age-related macular degeneration

Geographic atrophy (GA), an untreatable advanced form of age-related macular degeneration, results from retinal pigmented epithelium (RPE) cell degeneration. Here we show that the microRNA (miRNA)-processing enzyme DICER1 is reduced in the RPE of humans with GA, and that conditional ablation of Dicer1, but not seven other miRNA-processing enzymes, induces RPE degeneration in mice. DICER1 knockdown induces accumulation of Alu RNA in human RPE cells and Alu-like B1 and B2 RNAs in mouse RPE. Alu RNA is increased in the RPE of humans with GA, and this pathogenic RNA induces human RPE cytotoxicity and RPE degeneration in mice. Antisense oligonucleotides targeting Alu/B1/B2 RNAs prevent DICER1 depletion-induced RPE degeneration despite global miRNA downregulation. DICER1 degrades Alu RNA, and this digested Alu RNA cannot induce RPE degeneration in mice. These findings reveal a miRNA-independent cell survival function for DICER1 involving retrotransposon transcript degradation, show that Alu RNA can directly cause human pathology, and identify new targets for a major cause of blindness.

Peptide aptamer mimicking RAD51-binding domain of BRCA2 inhibits DNA damage repair and survival in Trypanosoma brucei

The eukaryotic DNA recombination repair protein BRCA2 is functional in the parasitic protozoan Trypanosoma brucei. The mechanism of the involvement of BRCA2 in homologous recombination includes its interaction with the DNA recombinase proteins of the RAD51 family. BRCA2 is known to interact with RAD51 through its unique and essential BRC sequence motifs. T. brucei BRCA2 homolog (TbBRCA2) has fifteen repeating BRC motifs as compared to mammalian BRCA2 that has only eight. We report here our yeast 2-hybrid analysis studies on the interactions of TbBRCA2 BRC motifs with five different RAD51 paralogues of T. brucei. Our study revealed that a single BRC motif is sufficient to bind to these RAD51 paralogues. To test the possibility whether a single 44 amino acid long repeating unit of the TbBRCA2 BRC motif may be exploited as an inhibitor of T. brucei growth, we ectopically expressed this peptide segment in the procyclic form of the parasite and evaluated its effects on cell survival as well as the sensitivity of these cells to the DNA damaging agent methyl methane sulfonate (MMS). Expression of a single BRC motif led to MMS sensitivity and inhibited cellular proliferation in T. brucei.

Mechanism of down-regulation of RNA polymerase III-transcribed non-coding RNA genes in macrophages by Leishmania

The parasitic protozoan Leishmania invades mammalian macrophages to establish infection. We reported previously that Leishmania manipulates the expression of several non-coding RNA genes (e.g. Alu RNA, B1 RNA, and signal recognition particle RNA) in macrophages to favor the establishment of their infection in the phagolysosomes of these cells (Ueda, Y., and Chaudhuri, G. (2000) J. Biol. Chem. 275, 19428-19432; Misra, S., Tripathi, M. K., and Chaudhuri, G. (2005) J. Biol. Chem. 280, 29364-29373). We report here the mechanism of this down-regulation. We found that the non-coding RNA (ncRNA) genes that are repressed by Leishmania infection in macrophages contain a "B-box" in their promoters and thus require the polymerase III transcription factor TFIIIC for their expression. We also found that Leishmania promastigotes through their surface protease (leishmanolysin or gp63) activate the thrombin receptor PAR1 in the macrophages. This activation of PAR1 raised the cytosolic concentration of Ca(2+) into the micromolar range, thereby activating the Ca(2+)-dependent protease μ-calpain. μ-Calpain then degraded TFIIIC110 to inhibit the expression of the selected ncRNA genes. Avirulent stocks of Leishmania not expressing surface gp63 failed to down-regulate ncRNAs in the exposed macrophages. Inhibition of PAR1 or calpain 1 in macrophages made them resistant to Leishmania infection. These data suggest that macrophage PAR1 and calpain 1 are potential drug targets against leishmaniasis.

SLUG-induced elevation of D1 cyclin in breast cancer cells through the inhibition of its ubiquitination

UbcH5c, a member of the UbcH5 family of protein ubiquitin conjugase E2 enzymes, is a critical component of biological processes in human cells, being the initial ubiquitinating enzyme of substrates like IκB, TP53, and cyclin D1. We report here that the metastasis regulator protein SLUG inhibits the expression of UbcH5c directly through chromatin remodeling and thus, among other downstream effects, elevates the level of cyclin D1, thus enhancing the growth rates of breast cancer cells. Overexpression of SLUG in the SLUG-deficient breast cancer cells significantly decreased the levels of mRNA and protein of UbcH5c but only elevated the protein levels of cyclin D1. On the contrary, knockdown of SLUG in SLUG-high breast cancer cells elevated the levels of UbcH5c while decreasing the level of cyclin D1 protein. SLUG is recruited at the E2-box sequence at the UbcH5c gene promoter along with the corepressor CtBP1 and the effector HDAC1 to silence the expression of this gene. Knockdown of UbcH5c in the SLUG-deficient human breast cells elevated the level of cyclin D1 as well as the rates of proliferation and invasiveness of these cells. Whereas the growth rates of the cells are enhanced due to overexpression of SLUG or knockdown of UbcH5c in the breast cancer cells tested, ER(+) cells also acquire resistance to the anti-estrogen 4-hydroxytamoxifen due to the rise of cyclin D1 levels in these cells. This study thus implicates high levels of SLUG and low levels of UbcH5c as a determinant in the progression of metastatic breast cancer.

Interpreting the SDS-PAGE protein patterns with self-organizing maps: application for the characterization of mosquito-pathogenic Bacillus strains

AIMS

To present the pairwise comparison of potential mosquito-pathogenic Bacillus strains based on their SDS-PAGE protein patterns and to evaluate their characteristic toxicity patterns.

METHODS AND RESULTS

In this work, 20 Bacillus strains were subjected to qualitative toxicity tests against Aedes aegypti and Culex quinquefasciatus larvae. The selected strains were then characterized by SDS-PAGE protein profiles. The highly heterogeneous multiple protein components of protein patterns were analysed using self-organizing map (SOM), a 'visualization and clustering' tool. Members of mosquitocidal Bacillus species were classified in four distinct clusters, and then toxicity patterns were examined. Cluster (1, 1) comprised of three highly toxic strains of Bacillus sphaericus: SPH88, 1593 and KSD-4; cluster (1, 2) consisted of two B. sphaericus strains: SSII-1 and Bsp-R that showed weak larvicidal activity; cluster (2, 1) constituted two B. sphaericus strains: WHO2297 and ISPC-5 that possessed moderate toxicity; and cluster (2, 2) contained four B. thuringiensis ssp. israelensis strains: ONR-60A, HD500, IPS70 and IPS82 belonging to serotype H14 but exhibited moderate to high mosquito larvicidal toxicity.

CONCLUSIONS

SOM served as a colour-coded alternate for easy visualization of similarities or dissimilarities between the strains even at the infra subspecies level. Furthermore, characteristic toxicity patterns of Bacillus strains of different clusters were determined.

SIGNIFICANCE AND IMPACT OF THE STUDY

Analysis of electrophoretic protein patterns using SOM provides a better insight into the inter-relationships of bacterial strains through similarity-based clustering and pairwise comparison of two strains.

Controlling magnetism of a complex metallic system using atomic individualism

When the complexity of a metallic compound reaches a certain level, a specific location in the structure may be critically responsible for a given fundamental property of a material while other locations may not play as much of a role in determining such a property. The first-principles theory has pinpointed a critical location in the framework of a complex intermetallic compound--Gd(5)Ge(4)--that resulted in a controlled alteration of the magnetism of this compound using precise chemical tools.

Mechanics of Flexible Needles Robotically Steered through Soft Tissue

The tip asymmetry of a bevel-tip needle results in the needle naturally bending when it is inserted into soft tissue. This enables robotic needle steering, which can be used in medical procedures to reach subsurface targets inaccessible by straight-line trajectories. However, accurate path planning and control of needle steering requires models of needle-tissue interaction. Previous kinematic models required empirical observations of each needle and tissue combination in order to fit model parameters. This study describes a mechanics-based model of robotic needle steering, which can be used to predict needle behavior and optimize system design based on fundamental mechanical and geometrical properties of the needle and tissue. We first present an analytical model for the loads developed at the tip, based on the geometry of the bevel edge and material properties of soft-tissue simulants (gels). We then present a mechanics-based model that calculates the deflection of a bevel-tipped needle inserted through a soft elastic medium. The model design is guided by microscopic observations of needle-gel interactions. The energy-based formulation incorporates tissue-specific parameters, and the geometry and material properties of the needle. Simulation results follow similar trends (deflection and radius of curvature) to those observed in experimental studies of robotic needle insertion.

Abstract LB-22: Repression of alpha-, beta- and gamma-catenin genes by SNAI2 in human breast cancer cells

SNAI2 is a transcriptional repressor protein implicated in the proliferation and metastasis of several human cancer cells. It binds to the E2-box sequence of its target gene promoters and down regulates their expressions by chromatin remodeling. While studying SNAI2-binding gene promoters in the human breast cells by ChIP-DSL technique, we found that SNAI2 binds to the promoters of the cytoskeleton proteins alpha-, beta- and gamma-catenins. These proteins help cells to maintain their epithelial phenotype and apico-basal polarity. Reduced expression of these proteins has been shown by IHC in high grade metastatic breast carcinoma. Here we report the molecular characterization of this repression. Highly invasive breast cancer cells (MDA-MB-231 and BT-549) express high levels of SNAI2 while mildly invasive (MCF 7 and MDA-MB-468) cells do not express SNAI2. Over-expression of SNAI2 in the SNAI2-negative MCF7 and MDA-MB-468 cells down regulated the mRNA and protein levels of the catenins in these cells. siRNA-mediated knock down of SNAI2 in the SNAI2-positive MDA-MB-231 and BT549 cells elevated the mRNA and protein levels of these proteins in these cells. SNAI2 over-expression induces the invasion and migration in non invasive cells, while down-regulation of the SNAI2 decreases the invasion and migration potential of highly invasive breast cancer cells. Chromatin immunoprecipitation data revealed co-recruitment of CtBP1 and HDAC1 at the catenin gene promoters in the SNAI2-expressing cells further indicating that SNAI2 represses these genes through chromatin remodeling. Our study thus adds to the mode of action of SNAI2 in mediating metastatic conversion of human breast cancer cells. Supported by the DOD-CDMRP IDEA Grant# W81XWH-06-1-0466 and the Susan G. Komen Breast Cancer Foundation grant# BCTR0707627 to GC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-22.

Abstract 435: Reduction of the invasive phenotype of SNAI overexpressing human breast cancer cells by peptide aptamer-mediated inhibition of SNAI protein functions

Two members of the SNAI superfamily of zinc-finger transcriptional repressors: SNAI1 (also known as SNAIL) and SNAI2 (also known as SLUG) are implicated in the induction of aggressiveness and metastatic phenotypes in human breast cancer cells. SNAI1 and SNAI2 are very similar in their amino acid sequences at the C-terminal zinc-finger domains, but the N-terminal repressor domain is somewhat different. SNAI2 has two essential sub-domains, SNAG and SLUG domains, required for its repressor activity. The SNAG domain is also important in SNAI1. We have developed a recombinant protein containing thioredoxin, a tri-repeat of SNAG and SLUG domains of SNAI2 and a membrane translocation motif (MTM; AAVLLPVLLAAP) for the protein to be targeted to the nucleus. We expressed and purified this protein from E. coli using the His-patch thiofusion expression system (Invitrogen). When delivered to MDA-MB-231 and BT549 cells, this aptamer inhibited the functions of the SNAI proteins. The effect of SNAI protein knockdown by the peptide aptamer on the transformed phenotypes of these cells was evaluated by investigating the following parameters: (i) Measurement of doubling time and saturation density by plating cells and performing daily counts. (ii) Evaluation of cellular proliferation by measuring incorporation of 5′-bromodeoxyuridine into logarithmically growing cells. (iii) Determination of anchorage-independent growth in soft agar assays and analysis of the number and size of colonies formed. (iv) Evaluation of the cellular migration in scratch assays and in modified Boyden Chamber/transwell migration assays (directional migration). (v) Measurement of cellular invasion in vitro by using Matrigel-coated chambers. (vi) Assessment of the sensitivity to anoikis by plating cells on poly-HEMA coated plates and determination of cells undergoing apoptosis with propidium iodine staining or annexin labeling and flow cytometric analysis. (vii) Performing 3D culture assays to analyze invasiveness, proliferation or matrix degradation. All these data indicated reduction of the invasive phenotypes of the SNAI protein over expressing highly aggressive and metastatic human breast cancer cells by the peptide aptamer. Wrapsome-mediated targeted delivery of this aptamer alone or with other drugs may be used to reduce the progression of breast cancer. Supported by the DOD-CDMRP IDEA Grant# W81XWH-06-1-0466 and the Susan G. Komen Breast Cancer Foundation grant# BCTR0707627 to GC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 435.