Becoming a congenital heart surgeon: the long and challenging road

Training in congenital cardiac surgery is potentially lengthier and more demanding than training in any other surgical field. The duration of training is proportional to the complexity of the specialization. The expertise of a wide range of procedures is required. There is no doubt that some individuals may acquire the requisite abilities with greater ease than others, but fundamentally, these are capabilities that can be taught and learnt. Moreover, congenital cardiac surgeons are required to have a detailed understanding of pathophysiology and morphology, in addition to the stamina and empathy required to manage these complex patients. A fellowship is just the start of such training and is followed by a long road eventually leading to a lifelong journey to become a qualified congenital cardiac surgeon. Effective mentorship is a prerequisite throughout training to guide surgeons on this journey.

Quantitative vestibular function tests in posterior circulation stroke patients: A review

While specific bedside examinations are known to be sensitive in identifying stroke among acute vestibular syndrome patients, complementary quantitative vestibular function testing can be helpful to quantify vestibular loss due to stroke. In contrast to peripheral vestibular dysfunction, diagnosis of central vestibular dysfunction can be challenging for unskilful clinicians. This article presents a comprehensive overview of quantitative vestibular function test findings such as the video head impulse test (vHIT), cervical vestibular evoked myogenic potentials (cVEMPs), ocular vestibular evoked myogenic potentials (oVEMPs), videonystagmography (VNG) and caloric test among stroke patients. Vestibulo-ocular reflex (VOR) gain is usually found normal among posterior inferior cerebellar artery (PICA) stroke patients but varies among anterior inferior cerebellar artery (AICA) stroke patients. Abnormal contralesional posterior semicircular canal VOR gain can be observed due to lesions in the medial longitudinal fasciculus (MLF). AICA and PICA stroke can impair cVEMPs, oVEMPs, and VNG (i.e., smooth pursuit and saccade functions). Strokes, particularly those involving the vestibular nucleus, including both upper, lower brainstem and cerebellum, can result in various abnormalities of smooth pursuit, saccade or calorics testing. The combined evaluations of VNG, vHIT, and VEMPs can be accurately used to complement and quantify bedside vestibular evaluation in diagnosing central vestibular dysfunction. In addition, as most studies were conducted amongst acute vestibular syndrome (AVS) patients, future studies that investigate the prevalence of vestibular dysfunction in recovering stroke patients are required.

A Novel Dialkylamino-Functionalized Chalcone, DML6, Inhibits Cervical Cancer Cell Proliferation, In Vitro, via Induction of Oxidative Stress, Intrinsic Apoptosis and Mitotic Catastrophe

In this study, we designed, synthesized and evaluated, in vitro, novel chalcone analogs containing dialkylamino pharmacophores in the cervical cancer cell line, OV2008. The compound, DML6 was selective and significantly decreased the proliferation of OV2008 and HeLa cells in sub-micromolar concentrations, compared to prostate, lung, colon, breast or human embryonic kidney cell line (HEK293). DML6, at 5 μM, arrested the OV2008 cells in the G2 phase. Furthermore, DML6, at 5 μM, increased the levels of reactive oxygen species and induced a collapse in the mitochondrial membrane potential, compared to OV2008 cells incubated with a vehicle. DML6, at 5 μM, induced intrinsic apoptosis by significantly (1) increasing the levels of the pro-apoptotic proteins, Bak and Bax, and (2) decreasing the levels of l the anti-apoptotic protein, Bcl-2, compared to cell incubated with a vehicle. Furthermore, DML6, at 5 and 20 μM, induced the cleavage of caspase-9, followed by subsequent cleavage of the executioner caspases, caspase-3 and caspase-7, which produced OV2008 cell death. Overall, our data suggest that DML6 is an apoptosis-inducing compound that should undergo further evaluation as a potential treatment for cervical cancer.

Novel Curcumin-Resveratrol Solid Nanoparticles Synergistically Inhibit Proliferation of Melanoma Cells

Polyphenols such as curcumin (Cur) and resveratrol (Res) have been recently shown to have potential to inhibit proliferation of highly aggressive melanoma cells. This study was designed to investigate the feasibility of a topical delivery system, using a solid lipid nanoparticles (SLNs) loaded delivery systems, that can enhance the skin penetration and anti-cancer efficacy of combination of these polyphenols. Negatively charged Cur-Res SLNs with a mean diameter of 180.2 ± 7.7 nm were prepared using high shear homogenization method. Cur-Res SLNs were found to be stable up to 2 weeks under 4°C. The in vitro release study showed that Res was released five time more than curcumin. The permeability of resveratrol was about 1.67 times that of curcumin from the SLN-gel formulation which was significantly (p < 0.05) lower than from SLN suspension. More than 70% of Cur-Res SLNs were bound to skin locally in a skin binding study suggesting potentially utility of Cur-Res SLNs in the treatment of localized melanoma. In fact, the electrical cell-substrate impedance sensing (ECIS) measurements suggested that Cur-Res combination has potential to stop cell migration of B16F10 melanoma cells. Furthermore, both, Cur-Res SLNs and Cur-Res solution at the ratio of 3:1 demonstrated a strong synergistic inhibition of SK-MEL-28 melanoma cell proliferation. Further evaluation of Cur-Res SLNs in vivo melanoma models are warranted to establish the clinical utility of Cur-Res formulations in melanoma therapy.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Abstract 2955: Development of non-apoptotic, caspase-independent cell death inducers against cancer cells

Since most cancer therapeutics currently exert their effects using apoptotic pathways to which cancer cells can become resistant, it is important to develop new drug molecules that work through non-apoptotic pathways. A novel, non-apoptotic cell death mechanism called “methuophagy,” which combines features of both autophagy and methuosis, is being examined using structure-activity relationship (SAR) studies of synthesized compounds. Methuosis is a non-apoptotic cell death that includes macropinocytosis and the fusing of smaller vesicles into larger vesicles that is seen along with cell death. BAPT compounds that induce methuophagy have been synthesized, and minor changes on a primary scaffold are being used to determine the SAR for the series. The series retains the 4-pyridinyl moiety that induced methuosis with the compound MOMIPP. Screening experiments with HCT-116 colorectal cancer cells (CRC), BT-20 triple-negative breast cancer cells (TNBC), and U-251 glioblastoma cancer cells (GBM) have shown that compounds having a rigid, completely aromatic structure with three aromatic centers induce methuophagy more potently than compounds with a “hydrazone-like” moiety or a non-aromatic linker. The cell death caused by methuophagy can be seen as early as 6 hours, with small vacuoles that coalesce together to form larger vacuoles. From these screening experiments, it has been concluded that the completely aromatic compounds are the most promising candidates for methuophagy drug development and will be used in experiments to determine protein targets and in vivo to further determine efficacy.

Citation Format: Mariah A. Pasternak, Noor Hussein, Karthikeyan Chandrabose, Paul W. Erhardt, Amit K. Tiwari. Development of non-apoptotic, caspase-independent cell death inducers against cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2955.

Abstract 2116: Cariprazine is a potent chemo-adjuvant against multidrug resistant colon and lung cancer

Multidrug resistance (MDR) is considered a continuing clinical problem, reducing the efficacy of cancer chemotherapy. The over expression of the ATP - binding cassette (ABC) family G2 (ABCG2) transporter is considered to be one of the main mechanisms responsible for mediating MDR in cancer. Molecular modeling studies have shown the significant affinity and binding mode of cariprazine, a dopamine D3-preferring D2/D3 receptor partial agonist, to the drug binding cavity of ABCG2 with a Glide XP score of the -5.761. Therefore, in this in vitro study, we determined the effect of cariprazine in increasing the efficacy of MX (an ABCG2 substrate) in the ABCG2 overexpressing cancer cell lines H460-MX20 and S1M1-80. Also, studies conducted to determine whether cariprazine is a reversal compound that specifically targets the ABCG2 protein. Alone, cariprazine, at concentrations up to 20 μM, did not significantly decrease cell viability. Cariprazine, at concentrations ranging from 1 to 20 μM, did not significantly alter the cytotoxicity of mitoxantrone (MX) in the parental non-small cell cancer cell line, H460 and colon cancer cell S1. However, cariprazine (1-20 μM) significantly enhanced the efficacy of ABCG2 substrate antineoplastic drug MX in the ABCG2- overexpressing MDR cell line, H460-MX20 and S1M1-80, by reducing the resistance fold from 28 to 1 and from 93 to 1.33, respectively. The intracellular accumulation of rhodamine 123 in the ABCG2-overexpressing cells, S1M1-80 was significantly increased by the addition of cariprazine, in a concentration-dependent manner (1 - 20 μM). Interestingly, 10 or 20 μM of cariprazine significantly decreased the expression levels of the ABCG2 protein in the colon and lung cancer cell lines, suggesting that cariprazine inhibits both the function and

expression of ABCG2 transporters at non-toxic concentrations. Overall, our results suggest that cariprazine, via several distinct mechanisms, can re-sensitize resistant cancer cells to mitoxantrone.

Citation Format: Noor Hussein, Angelique Nyinawbera, Haneen Amawi, Amit Tiwari. Cariprazine is a potent chemo-adjuvant against multidrug resistant colon and lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2116.

Proteomics Profiling of Pancreatic Cancer and Pancreatitis for Biomarkers Discovery

Pancreatic cancer is one of the most aggressive malignancies with an increase in incidence predicted, particularly in African Americans. Pancreatic cancer is considered a silent disease with poor prognosis and a lack of early biomarkers for detection. Proteomics has been applied in many diseases for identifying or discovering biomarkers. It has long been suggested that chronic pancreatitis may be a risk factor for developing pancreatic cancer. This study identified proteins that are altered in expression in pancreatic cancer and pancreatitis compared to normal using proteomic technology. Proteins were extracted from laser captured micro-dissected tissues and separated in 2-DPAGE and imaged. The protein profiles of pancreatic cancer and pancreatitis are similar but differed with the protein profile of normal adjacent tissues. Representative proteins, overexpressed in tumor and pancreatitis but not normal tissues, were excised from gels, subjected to in-gel digestion, and analyzed by MALDI-TOF mass spectrometry. Proteins identified included transferrin, ER-60 protein, proapolipoprotein, tropomyosin 1, alpha 1 actin precursor, ACTB protein, and gamma 2 propeptide, aldehyde dehydrogenase 1A1, pancreatic lipase and annexin A1. Several proteins, which were shown in pancreatic cancer, were also observed in pancreatitis samples. Understanding the role of these specific proteins and their mechanistic action will give insights into their involvement in pancreatic cancers.

Cariprazine, A Dopamine D₂/D₃ Receptor Partial Agonist, Modulates ABCG2-Mediated Multidrug Resistance in Cancer

Multidrug resistance (MDR) is a continuing clinical problem that limits the efficacy of chemotherapy in cancer. The over expression of the ATP-binding cassette (ABC) family G2 (ABCG2) transporter is one of the main mechanisms that mediates MDR in cancer. Molecular modeling data indicated that cariprazine, a dopamine D₂/D₃ receptor partial agonist, had a significant binding affinity for ABCG2 transporter with a Glide XP score of -6.515. Therefore, in this in vitro study, we determined the effect of cariprazine on MDR resulting from the overexpression of ABCG2 transporters. Alone, cariprazine, at concentrations up to 20 μM, did not significantly decrease cell viability. Cariprazine, at concentrations ranging from 1 to 10 μM, did not significantly alter the cytotoxicity of mitoxantrone (MX) in the parental non-small cell cancer cell line, H460 and colon cancer cell S1. However, cariprazine (1⁻20 μM) significantly enhanced the efficacy of ABCG2 substrate antineoplastic drug MX in the ABCG2-overexpressing MDR cell line, H460-MX20 and S1M1-80, by reducing the resistance fold from 28 to 1 and from 93 to 1.33, respectively. Cariprazine, in a concentration-dependent (1⁻20 μM), significantly increased the intracellular accumulation of Rhodamine 123 in S1M1-80. Interestingly, 10 or 20 μM of cariprazine significantly decreased the expression levels of the ABCG2 protein in the colon and lung cancer cell lines, suggesting that cariprazine inhibits both the function and expression of ABCG2 transporters at nontoxic concentrations. Overall, our results suggest that cariprazine, via several distinct mechanisms, can resensitize resistant cancer cells to mitoxantrone.

Efficient syntheses and anti-cancer activity of xenortides A-D including ent/epi-stereoisomers

A one-pot, two-step, total synthesis of naturally occurring xenortides A, B, C and D, (Xens A-D) isolated from the bacterium Xenorhabdus nematophila, and an entire complementary set of stereoisomers, has been achieved. Compounds were synthesized utilizing an isocyanide-based Ugi 4-CR followed by facile N-Boc deprotection. The reaction sequence took advantage of the chiral pool of N-Boc protected amino acids (l-Leu/Val and d-Leu/Val) with aryl isocyanides, phenyl acetaldehyde and methylamine giving the desired Xens A-D (A and B >98% ee) and all subsequent stereoisomers in reasonable yields upon deprotection followed by separation of diastereomers. Also, detailed mechanistic insights for diastereoselectivity of (-)-Xen A, as a model in the Ugi 4-CR, has been described. Moreover, for the first time, this focused library was screened for cytotoxicity against a panel of epithelial cancer cell lines as well as normal cell lines with an MTT proliferation assay. The structure-activity relationship (SAR) study demonstrated that tryptamides Xen B and D were more active than phenylethylamides Xen A and C. Furthermore, (-)-Xen B (IC50 = 19-25 μM) and ent-(+)-Xen D (IC50 = 21-26 μM) gave the highest cytotoxicity and they were also found to be non-toxic toward normal cells. Importantly, the SAR results indicate that the stereochemistry at C8 and C11 in (-)-Xen B and ent-(+)-Xen D play a critical role in cytotoxic activity.

Thienopyrimidine derivatives exert their anticancer efficacy via apoptosis induction, oxidative stress and mitotic catastrophe

In this study, a series of 13 structural variants of thieno[2,3d]pyrimidine derivatives (6a-6m) were synthesized and screened for cytotoxicity in a panel of colorectal, ovarian, and brain cancer cell lines. The selectivity of the compounds was assessed by determining the cytotoxicity in normal epithelial cell line (CHO). The most potent compound, 6j, was efficacious (with IC₅₀ range of 0.6-1.2 μM) in colon (HCT116 and HCT15), brain (LN-229 and GBM-10) and ovarian (A2780 and OV2008) cancer cell lines. In contrast, in the normal cell line (CHO), the IC₅₀ values for 6j were 14 ± 1.3 μM. Compound 6j significantly inhibited the clonogenic potential of HCT116, OV2008 and A2780 cell lines in concentration - dependent (0.5-4 μM) manner. Also, 6j induced 1) formation of reactive oxygen species; 2) apoptosis and 3) mitotic catastrophe in HCT116 and OV2008 cells (IC₅₀ = 0.5-2 μM). Furthermore, apoptosis was the predominant mechanism of death in A2780 cells. The cytotoxicity of 6j in wild type HCT116 cells was similar to that in HCT116 cells lacking the apoptotic genes for Bax, Bak, or Bak and Bax, indicating that 6j induces mitotic catastrophe as alternative mechanism of death when when certain apoptotic proteins are absent. In summary, this study has identified a lead molecule, 6j, that selectively induces oxidative stress, apoptosis and mitotic catastrophe in specific cancer (colon and ovarian) cell lines.

Abstract 1191: The dopamine (DA) D3 receptor antagonists (PG01037, NGB2904, SB-277011A, and U99194) significantly attenuate ABCG2-mediated multidrug resistance

ATP-binding family G2 (ABCG2) transporters are known to produce multidrug resistance (MDR) and limit successful cancer chemotherapy. Using molecular modeling, we obtained data indicating that highly potent and selective dopamine (DA) D3 receptor antagonists had significant docking scores for the active site of the ABCG2 transporter. In this in vitro study, we determined the effect of the D3 receptor antagonists (PG01037, NGB2904, SB-277011A, and U99194) on MDR resulting from the overexpression of ABCG2 transporters. The D3 receptor antagonists alone did not significantly affect the viability of HEK293/ABCG2, H460/MX-20, S1-M1-80 or A549-MX-10 cells, which overexpress ABCG2 transporters. However, the D3 receptor antagonists (PG01037, NGB2904, SB-277011A, and U99194) significantly increased the efficacy of the anticancer drugs mitoxantrone and doxorubicin in the above mentioned cell lines. Efflux studies indicated that both PG01037 and NGB2904 significantly decreased the efflux of rhodamine 123 from H460-MX20 cells. Interestingly, PG01037 and NGB2904 significantly decreased the expression levels of the ABCG2 protein levels as shown by immunocytochemical and Western blot analysis. This suggests that D3 antagonists inhibit both function and expression of ABCG2 transporters at relevant non-toxic concentrations. In conclusion, our in vitro results indicate that PG01037, NGB2904, SB-277011A, and U99194 reverse resistance to mitoxantrone and doxorubicin mediated by overexpression of ABCG2 transporters. Further mechanistic and animal studies are warranted to establish the clinical use of D3 receptor antagonists in reversing ABCG2-mediated MDR.

Citation Format: Noor Hussein, Haneen Amawi, Charles R. Ashby, Karthikeyan Chandrabose, Roopali Mittal, Ryann Christman, Piyush Trivedi, Amit Tiwari. The dopamine (DA) D3 receptor antagonists (PG01037, NGB2904, SB-277011A, and U99194) significantly attenuate ABCG2-mediated multidrug resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1191. doi:10.1158/1538-7445.AM2017-1191

Abstract 2238: Novel sylibin analogues target ovarian cancer EMT-Wnt/β-catenin resistance pathways

Ovarian cancer (OC) is one of most lethal malignancies in woman reproductive tract. The OC diagnosed in advanced stage (III-IV) patients is highly aggressive and relapses back in over 80% patient after initial response to chemotherapy. Currently used chemotherapies are limited due to significant adverse/toxic effects, a narrow therapeutic index, and development of multidrug resistance mediated by the epithelial-to-mesenchymal transition (EMT) and cancer cell membrane efflux transporters. It is presumed that an ideal anti-OC drug that has diverse mechanisms, would inhibit several key cell-survival signaling and resistance pathways when combined with conventional chemotherapy (paclitaxel and cisplatin). Silybin, a polyphenolic flavonoid, has previously shown to inhibit metastasis by inhibition of EMT pathways and bypass other drug resistance factors i.e. efflux transporters in ovarian cancer both in vitro and in vivo. However, clinical use of silybin is limited due to their poor absorption and low bioavailability and poor potency. To overcome this, we designed and synthesized 11 silybin derivatives using molecular modeling, computer aided drug design, structure activity relationship, natural product lead optimization and ring disjunction approaches. In our preliminary findings, we found the lead molecule (15k) to have a cytotoxicity (IC50&lt1µM) with potency more than 200-fold compared to silybin (IC50~150µM). The 15k was found to be around 10-fold selective in OC cells (OV2008, A2780) compared to normal ovarian cells. Additionally, compared to other cancer cells belonging to prostate, breast, lung, 15k was (3-6)-fold selective in OC cells (OV2008, A2780). The 15k produced synergistic activity and potentiated the cytotoxic effects of platinum (cisplatin), anthracyclines (doxorubicin) and taxane (paclitaxel) anticancer agents. While 15k also reversed the drug resistance mediated by ABC-efflux transporters to paclitaxel and doxorubicin. Mechanistically, the cytotoxic effect of lead compound 15k, as determined by using molecular biology assays, was found to be due to inhibition of apoptosis, tubulin inhibition, and inhibition of stemness pathways (Wnt-β-catenin-EMT). The 15k had significant anti-metastatic effects as shown by their inhibition of migration and invasion potential on OC cells. In silico findings suggest that pharmacokinetic [PK] profiles of these compounds are favorable compared to silybin. Further in vivo PK/pharmacodynamic studies are underway to establish the clinical use of lead molecule in advanced metastasized, drug resistant OC patients.

Citation Format: Haneen A. Amawi, Noor Hussein, Aubry Fetcenkoa, Rawan Alnafisah, Karthikeyan Chandrabose, Elangovan Manivannan, Piyush Trivedi, Amit K. Tiwari. Novel sylibin analogues target ovarian cancer EMT-Wnt/β-catenin resistance pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2238. doi:10.1158/1538-7445.AM2017-2238

Prevalence, factors influencing and knowledge about adherence to lipid-lowering therapy among hyperlipidemia patients

BACKGROUND

Hyperlipidaemia is a significant risk factor for cardiovascular disease. However, adherence to lipidlowering therapy is often unsatisfactory due to a combination of patient factors, therapy, socio-economic and health system-related factors.

AIMS

to identify the prevalence of adherence to lipidlowering therapy, the factors contributing to non-adherence and knowledge regarding hyperlipidaemia and its' treatment among Malaysian patients with hyperlipidemia.

METHODS

A quantitative study using a cross-sectional survey was carried out in an urban primary care clinic in August 2015. Patients on lipid-lowering therapy for ≥ 1 year aged ≥ 18 years were selected using simple random sampling. consenting patients answered a selfadministered questionnaire (in Malay/English) which included socio-demographic profile, hyperlipidaemia profile, adherence to lipid-lowering therapy (using the Morisky Medication Adherence scale-8; score ≥ 6 taken as adherent), reasons leading to non-adherence, knowledge regarding hyperlipidaemia and its' treatment, and use of non-allopathic medicine.

RESULTS

the response rate was 90.7%. the prevalence of adherence to lipid-lowering therapy was 82.4%. "the most common reasons for non-adherence was being worried about side effect of lipid-lowering agent (71.4%), followed by the need to take too many drugs in a day (61.4%) and negative influences by friends, relative and mass media (60%)". Factors associated with non-adherence include male gender, on longer duration of therapy, less frequency of follow-up, less number of follow-up clinics, taking medication at night/random timing and having lower knowledge scores.

CONCLUSION

Overall the prevalence of adherence was high in patients with hyperlipidaemia. Interventions to boost adherence should target those who were identified as nonadherent.

Design and discovery of silybin analogues as antiproliferative compounds using a ring disjunctive - Based, natural product lead optimization approach

The present study reports the synthesis and anticancer activity evaluation of twelve novel silybin analogues designed using a ring disjunctive-based natural product lead (RDNPL) optimization approach. All twelve compounds were tested against a panel of cancer cells (i.e. breast, prostate, pancreatic, and ovarian) and compared with normal cells. While all of the compounds had significantly greater efficacy than silybin, derivative 15k was found to be highly potent (IC₅₀ < 1 μM) and selective against ovarian cancer cell lines, as well as other cancer cell lines, compared to normal cells. Preliminary mechanistic studies indicated that the antiproliferative efficacy of 15k was mediated by its induction of apoptosis, loss of mitochondrial membrane potential and cell cycle arrest at the sub-G1 phase. Furthermore, 15k inhibited cellular microtubules dynamic and assembly by binding to tubulin and inhibiting its expression and function. Overall, the results of the study establish 15k as a novel tubulin inhibitor with significant activity against ovarian cancer cells.

The dopamine D3 receptor antagonists PG01037, NGB2904, SB277011A, and U99194 reverse ABCG2 transporter-mediated drug resistance in cancer cell lines

The ATP - binding cassette (ABC) family G2 (ABCG2) transporters are known to produce multidrug resistance (MDR) in cancer, thereby limiting the clinical response to chemotherapy. Molecular modeling data indicated that certain dopamine (DA) D₃ receptor antagonists had a significant binding affinity for ABCG2 transporter. Therefore, in this in vitro study, we determined the effect of the D₃ receptor antagonists PG01037, NGB2904, SB277011A, and U99194 on MDR resulting from the overexpression of ABCG2 transporters. The D₃ receptor antagonists, at concentrations >100 μM, did not significantly affect the viability of H460-MX20, S1M1-80, A549-MX10 or wild type ABCG2 overexpressing (HEK293-R2) cells. However, at concentrations ranging from 0.01 to 10 μM, the D₃ receptor antagonists PG01037, NGB2904, SB-277011A, and U99194 significantly increased the efficacy of the anticancer drugs mitoxantrone and doxorubicin in ABCG2-overexpressing MDR cells. Efflux studies indicated that both PG01037 and NGB2904, at a concentration of 5 μM, significantly decreased the efflux of rhodamine 123 from H460-MX20 cells. Interestingly, 5 μM of PG01037 or NGB2904 significantly decreased the expression levels of the ABCG2 protein, suggesting that these compounds inhibit both the function and expression of ABCG2 transporters at non-toxic concentrations.

Effectiveness of a colour coded HbA1c graphical record in improving diabetes control in people with type 2 diabetes: a randomized control trial

We conducted a six-month randomized-controlled-trial to evaluate the effectiveness of a colour-coded HbA1c-graphical record in improving HbA1c level among type 2 diabetes patients. There was an improvement in the mean HbA1c knowledge score but the usage of the colour-coded HbA1c-graphical record did not produce reduction in the HbA1c level.

A diet high in omega-3 fatty acids does not improve or protect cognitive performance in Alzheimer’s transgenic mice

Although a number of epidemiologic studies reported that higher intake of omega-3 fatty acids (largely associated with fish consumption) is protective against Alzheimer's disease (AD), other human studies reported no such effect. Because retrospective human studies are problematic and controlled longitudinal studies over decades are impractical, the present study utilized Alzheimer's transgenic mice (Tg) in a highly controlled study to determine whether a diet high in omega-3 fatty acid, equivalent to the 13% omega-3 fatty acid diet of Greenland Eskimos, can improve cognitive performance or protect against cognitive impairment. Amyloid precursor protein (APP)-sw+PS1 double transgenic mice, as well as nontransgenic (NT) normal littermates, were given a high omega-3 supplemented diet or a standard diet from 2 through 9 months of age, with a comprehensive behavioral test battery administered during the final 6 weeks. For both Tg and NT mice, long-term n-3 supplementation resulted in cognitive performance that was no better than that of mice fed a standard diet. In NT mice, the high omega-3 diet increased cortical levels of omega-3 fatty acids while decreasing omega-6 levels. However, the high omega-3 diet had no effect on cortical fatty acid levels in Tg mice. Irrespective of diet, no correlations existed between brain omega-3 levels and cognitive performance for individual NT or Tg mice. In contrast, brain levels of omega-6 fatty acids were strongly correlated with cognitive impairment for both genotypes. Thus, elevated brain levels of omega-3 fatty acids were not relevant to cognitive function, whereas high brain levels of omega-6 were associated with impaired cognitive function. In Tg mice, the omega-3 supplemental diet did not induce significant changes in soluble/insoluble Abeta within the hippocampus, although strong correlations were evident between hippocampal Abeta(1-40) levels and cognitive impairment. While these studies involved a genetically manipulated mouse model of AD, our results suggest that diets high in omega-3 fatty acids, or use of fish oil supplements (DHA+EPA), will not protect against AD, at least in high-risk individuals. However, normal individuals conceivably could derive cognitive benefits from high omega-3 intake if it corrects an elevation in the brain level of n-6 fatty acids as a result. Alternatively, dietary fish may contain nutrients, other than DHA and EPA, that could provide some protection against AD.

Gene expression profiling in insulinomas of Men1 beta-cell mutant mice reveals early genetic and epigenetic events involved in pancreatic beta-cell tumorigenesis

Mutations of the MEN1 gene lead to the occurrence of multiple endocrine neoplasia type 1 (MEN1). To gain insights into the mechanisms of the tumorigenesis related to MEN1 inactivation, we have used mice in which the Men1 gene was specifically disrupted in pancreatic beta-cells. In these mice, we observed full penetrance of insulinoma with defined histological characteristics of tumorigenesis. To identify the genetic factors taking part in the tumour development, we performed gene expression profiling analysis of these insulinomas at different stages. Here, we show that in late stage insulinomas, 56 genes are up-regulated and 194 are down-regulated more than fourfold compared with normal pancreatic islets. Clustering analysis reveals the deregulation of Hox gene family and the genes involved in cell proliferation and cell cycle control. The altered expression of Igf2, Igfbp3 and Igfbp6 as well as cyclin A2, B2 and D2 are confirmed by quantitative RT-PCR, with the overexpression of all the three cyclins found in early stage insulinomas. Moreover, an increased proportion of cyclin A2- and D2-expressing cells and the overexpression of insulin-like growth factor 2 (IGF2) protein are detected in mouse Men1 insulinomas by immunostaining. Interestingly, the analysis of DNA methylation patterns by quantitative serial pyrosequencing reveals that four specific CpGs in the intragenic differentially methylated region 2 (DMR2) region of the Igf2 gene known to augment transcription through methylation are significantly hypermethylated in insulinomas of Men1 beta-cell mutant mice at 6 and 10 months of age, even before IGF2 overexpression can be detected. Thus, our data indicate the involvement of both genetic and epigenetic mechanisms in early tumorigenesis of beta-cells related to MEN1 inactivation.

[Frequency of complications after transthoracic fine-needle biopsy of lung tumors]

Transthoracic fine-needle biopsy (TFNB) is a valuable method of recognizing changes in lungs, especially suspected of cancer. Such operations are cheap, don't demand expensive instruments and are possible to perform in each pneumonology ward, especially if they are an ideal supplement for bronchofibroscoping examination. The possibility of quick and effective performance of transthoracic biopsy shortens the diagnostics considerably. From January 1997 to April 1999 there were performed 406 operations of TFNB. There were 334 people operated on (294 men--74.5%; 85 women--25.5%), average age for the whole group of patients--62.8 (+/- 10.4 years). The patients were divided into two groups considering hospitalization places: I--patients from (not transported for operation)--135 (40.4%), II--patients transported for operation from another hospitals--199 (59.6%) The examination was performed under control of rtg apparatus (7600 OEC Medical System with mobile x-ray tube on a C-arm and laser localizer). The usual complication was an pneumothorax--52 cases (12.8%); drained--16 cases (3.9%). An average depth of inserting in an early pneumothorax is 6.56 (+/- 0.73), in a late pneumothorax--8.6 cm (+/- 1.75), (p = 0.0015). An average depth of inserting in a drained pneumothorax was 8.9 cm (+/- 2.17), in a non-drained pneumothorax 7.7 cm (+/- 1.3) (p = 0.024). Patients that had to be transported for the operation had pneumothoraxes that needed to be drained considerably more often: 14 cases in 199 comparing to 2 in 135 among patients not demanding to be transported (p = 0.02). Pneumothoraxes appeared more often after indicating tumors of smaller size, from 3 cm--21.6%; 3.1-6 cm--13.3% (p = 0.036). From another complications one could notice: hemoptysis--4 cases; subcutaneous emphysema--1 case; fever and shivers--1 case; hypotonia--2 cases; cough--1 case. Those complications were treated symptomatically or vanished themselves.

Leber's congenital amaurosis with anterior keratoconus in Pakistani families is caused by the Trp278X mutation in the AIPL1 gene on 17p

BACKGROUND

Leber's congenital amaurosis (LCA) represents the earliest and severest form of retinal dystrophy leading to congenital blindness. A total of 20% of children attending blind schools have this disease. LCA has a multigenic basis and is proving central to our understanding of the development of the retina. We describe the clinical and molecular genetic features of four inbred pedigrees from neighbouring remote villages in northern Pakistan, in which some of the affected members have concurrent keratoconus.

METHODS

History-taking and physical and eye examinations were performed in the field. Venipuncture, DNA extraction, studies of linkage to known LCA genes, automated sequencing and polymorphism analyses for haplotype assessments were done.

RESULTS

We examined 12 affected and 15 unaffected family members. By history, there were an additional nine blind people in the four pedigrees. In each pedigree a consanguineous marriage was evident. We found a homozygous nonsense mutation in the AIPL1 gene, which replaces a tryptophan with a stop codon (Trp278X). The phenotype is severe and variable, despite the common molecular genetic etiology in each family. Affected patients had hand motion to no light perception vision and fundus findings ranging from maculopathy to diffuse pigmentary retinopathy. Three affected members had definite keratoconus, and two were suspects based on mild cone formation in the cornea of at least one eye.

INTERPRETATION

We have identified four Pakistani families with a severe form of LCA that is associated with severe keratoconus in some affected members. The molecular etiology in all four families is a homozygous nonsense mutation, Trp278X, in the photoreceptor-pineal gene AIPL1. To our knowledge, this is one of the first phenotype-genotype correlations of AIPL1-associated LCA.

[Pulmonary blastoma and related primary malignant pulmonary neoplasms]

During the last decade more diagnoses of pulmonary blastoma were made worldwide than in previous decades. Whether this increased frequency is caused by better diagnostic procedures (immunochemistry, electron microscopy) or by the growing number of patients having this neoplasm is difficult to distinguish. We present controversies concerning pulmonary blastoma and related biphasic primary pulmonary neoplasms. We agree with Wick et al. that cases in children (called pleuropulmonary blastoma) should be differentiated from cases in adults, which show many similarities to bronchogenic lung cancer. However, our opinion is that the new classification system proposed by Wick et al. does not take into account cases of PB in young adults with intropulmonary growth of the tumor.

[Fine needle biopsy in diagnosis of lung tumors]

Fine-needle biopsy is one of the method used in diagnosis of lung tumors. In this study the results of 192 biopsies performed by x-ray apparatus inspection were analysed. There was shown that lung cancer was recognized in over 50% of patients studied. In another cases non-specific inflammation (31%), lung fibrosis (1%), tuberculosis (1%), purulent inflammation (1%), blood (7%) were recognized. These results indicate for usefulness of this method in diagnosis of not only peripheral, but also central localized lung tumors.

The effect of BCG on thoracic duct lymphocytes

Adoptive immunotherapy is becoming increasingly more important in the management of advanced malignancies. This report describes the results of immunomodulation therapy with BCG in the Dunning tumor. In addition it describes new techniques in the harvesting of lymphocytes. Thoracic duct lymphocytes from 34 rats were evaluated for the effect of the presence of the Dunning R-3327 AT-3 tumor as well as for the response to bacillus Calmette Guerin (BCG). Both tumor and BCG resulted in significant changes in the helper/suppressor T cell ratios.

Intraocular pressure decrease in household contacts of patients with Hansen's disease and endemic control subjects

We compared the intraocular pressure in 150 urban household contacts of patients with Hansen's disease and 132 endemic control subjects from an urban population in Karachi, Pakistan, who were matched in regard to race, age, gender, and socioeconomic status. The mean intraocular pressure in the upright position was 12.6 mm Hg in the right eye and 12.9 mm Hg in the left eye in household contacts of patients with Hansen's disease and 15.3 mm Hg in the right eye and 15.4 mm Hg in the left eye in the endemic control population (P < .0005). The postural change in intraocular pressure from the upright to supine position was 1.7 mm Hg in the right eye and 2.1 mm Hg in the left eye in the household contacts group and 1.3 mm Hg in the right eye and 1.5 mm Hg in the left eye in the endemic control group (P < .0006). Our findings, especially in view of past observations in intraocular pressure changes in patients with Hansen's disease, raise serious questions about possible early ocular susceptibility to Mycobacterium leprae infection and about public health issues, including possible early indication of disease.

Intraocular pressure changes and postural changes of intraocular pressure in experimentally induced Hansen's disease of rhesus, mangabey, and African green monkeys

In our long term evaluation of patients with Hansen's disease we have frequently found reduction of their intraocular pressure. Furthermore, we noted changes in their intraocular pressure on change of posture. To determine if these changes have any significance we measured the intraocular pressures of 24 experimentally infected and 39 control monkeys in both sitting and reclining positions. We found significant reduction of intraocular pressure in 66.7% compared with controls in the sitting position, and a significant increase in intraocular pressure in 79% when checked first in the sitting then in the reclining position. We offer a possible pathophysiological explanation as to why the changes occur.

Intraocular pressure and iris denervation in Hansen's disease

We retrospectively analyzed 255 Hansen's disease patients and found low intraocular pressure (less than 7 mm Hg) in 12% of them. We showed a correlation between low intraocular pressure and avascular keratitis and iritis. We also found that patients with low intraocular pressures had abnormally large postural changes in intraocular pressure. We speculate that abnormalities in the autonomic innervation of the anterior segment of the eye may be related to the intraocular pressure abnormalities. Further investigations along this line may increase our understanding not only of the pathophysiology of Hansen's disease but also of the mechanisms regulating homeostasis of intraocular pressure.

Low intraocular pressure and postural changes in intraocular pressure in patients with Hansen's disease

We found intraocular pressures of less than 7 mm Hg in 11 of 72 patients (15%) with early Hansen's disease. Furthermore, significant postural changes in intraocular pressure (greater than 30%) occurred in 43 of 72 patients (60%). This loss of intraocular pressure homeostasis, which results from reduced aqueous humor production or increased uveoscleral outflow with reduced local adrenergic control in the ciliary body-iris-trabecular meshwork region, suggests that early autonomic neuropathy of the eye may occur in Hansen's disease. The only predictive value for significant postural change in intraocular pressure was the presence of immunologically unstable disease.

Gas chromatography-mass spectrometry of isobutyl ester trimethylsilyl ether derivatives of bile acids and application to the study of bile sterol and bile acid biosynthesis in rat liver epithelial cell lines

The derivatization of bile acids into trimethylsilyl ether isobutyl ester (IBTMS) and of neutral sterols into trimethylsilyl ether (TMS) allowed the separation on an OV-1 capillary gas chromatography column of 15 bile steroids as follows: cholesterol, 7 alpha-hydroxycholesterol, 6 beta-hydroxycholesterol, 6 alpha-hydroxycholesterol, 7 beta-hydroxycholesterol, lithocholate, deoxycholate, 25-hydroxycholesterol, chenodeoxycholate, cholate, murocholate, hyodeoxycholate, ursodeoxycholate, hyocholate, and beta-muricholate. Fragmentation data of the coupled gas chromatographic-mass spectrometric (GC-MS) analysis of these nine bile acids as IBTMS derivatives under electron impact and chemical ionizations (methane, isobutane, and ammonia) are given. The ammonia chemical ionization appears to be the best mode for compound identification and quantitation due to fragmentations into high mass ions. The comparison of methylene units of the five sterols as TMS derivatives and of each type of methyl, TMS, or isobutyl ester of the nine bile acids as TMS ethers showed that isobutyl esterification increased dramatically the retention time of the bile acids, allowing their separation after the neutral sterols. Different methods of GC-MS analysis were applied to the study of bile steroid secretion in long-term rat liver epithelial cell lines, either serum-supplemented cell lines or serum-free cell lines, growing in serum-free medium since the primary explanation or after adaptation of serum-supplemented lines to this medium. It is demonstrated for the first time that liver epithelial cell lines maintain the metabolic pathway leading from synthesized cholesterol to dioxygenated sterols and the two normal main primary bile acids of the liver, chenodeoxycholic acid and cholic acid, up to 32-47% of the in vivo daily rate, and in addition the production of alpha-muricholic acid, the bile acid marker of murine liver.

Biosynthesis of sterols and bile acids in rat liver epithelial cell lines

A rat liver epithelial cell line growing in a serum-supplemented medium expressed biosynthetic pathways of bile sterols and of free and conjugated chenodeoxycholic and cholic acids, the main primary bile acids of the liver. They were identified and measured by gas chromatography-mass spectrometry. The bile steroid secretion in the serum-supplemented cell line was established upon incubation in a serum-free medium which was demonstrated to sustain cell growth, allowing elimination of the interference of exogenous bile steroids and effectors. The free bile acid secretion was also expressed in a subline adapted to proliferate in this serum-free medium, i.e., a basal medium supplemented with 4 g/l albumin carrying 7.6 muequiv./l of a mixture of six long-chain free fatty acids but without any addition of hormones and growth factors. In addition, the rat liver epithelial cell line growing in the serum-supplemented medium maintained, with time, a steady-state of bile acid secretion over a lifespan of 500 days. In the two types of liver epithelial cell lines, dexamethasone and chenodeoxycholic acid supplementation exerted, individually, either a stimulating or an inhibiting effect on the bile acid secretion concurrently with the hydroxylation of chenodeoxycholic acid into alpha-muricholic acid.