Regional Therapy Approaches for Gastric Cancer with Limited Peritoneal Disease.

PURPOSE: Despite advances in systemic therapy, outcomes of patients with gastric cancer (GC) peritoneal carcinomatosis (PC) remain poor, in part because of poor penetrance of systemic therapy into peritoneal metastasis due to the plasma-peritoneal barrier and anarchic intra-tumoral circulation. Hence, regional treatment approach with administration of chemotherapy directly into the peritoneal cavity (intraperitoneal, IP) under various conditions, combined with or without cytoreductive surgery (CRS) has remained an area of significant research interest. The purpose of this review is to provide high-level evidence for regional treatment approaches in the management of GCPC with limited peritoneal disease. METHODS: A review of the current literature and ongoing clinical trials for regional IP therapies for GCPC was performed. Studies included in this review comprise of phase III randomized controlled trials, non-randomized phase II studies, high-impact retrospective studies, and active ongoing clinical trials for each available IP modality. RESULTS: The three common IP approaches are heated intraperitoneal chemotherapy (HIPEC), normothermic intraperitoneal chemotherapy (NIPEC) and more recently introduced, pressurized intraperitoneal aerosolized chemotherapy (PIPAC). These IP approaches have been combined with systemic therapy and/or CRS with varying degrees of promising results, demonstrating evidence of improvements in survival rates and peritoneal disease control. Patient selection, optimization of systemic therapy, and completeness of cytoreduction have emerged as major factors influencing the design of contemporary and ongoing trials. CONCLUSION: IP chemotherapy has a clear role in the management of patients with GCPC, and when combined with CRS in appropriately selected patients has the potential to significantly improve survival. Ongoing and upcoming IP therapy clinical trials hold great promise to shape the treatment paradigm for GCPC.

Adoption of cytoreductive surgery in the management of peritoneal malignancies-Global trends.

Cytoreductive surgery (CRS) has now been accepted as an integral component in the management of gastrointestinal and gynecological cancers with peritoneal metastases. Since the adoption of CRS is influenced by access to advanced medical facilities, trained multidisciplinary teams, and funding, there is wide variability in incorporation of CRS into routine clinical practice between high- versus low- and middle-income countries. This review highlights the global trends in the adoption of CRS for peritoneal malignancies with a specific focus on the establishment of CRS programs and barriers to incorporate CRS into routine clinical care in low- and middle-income countries.

Somatic mutations in the DNA repairome in prostate cancers in African Americans and Caucasians.

Most hereditary tumors show aberrations in DNA repair genes or their regulators. In contrast, only a minority of sporadic tumors show alterations in these genes. As a result, genomic instability is currently considered an enhancer of tumorigenesis rather than an obligatory event in this process. However, tumor heterogeneity presents a significant technical challenge for most cancer genomics studies performed at less than 100× mean resolution depth. To address the importance of genomic instability in prostate carcinogenesis and tumor progression, we performed ultrahigh depth exome sequencing of 124 DNA damage repair/response (repairome) genes in 63 tumors and matched normal tissue samples in African Americans and Caucasians. The average sequence depth was 712-fold for DNA isolated from normal tissue and 368-fold for FFPE tumors. We identified 671 somatic mutations in tumors from African Americans and 762 somatic mutations in tumors in Caucasians. The most frequently mutated DNA repairome genes were EXO1, ATR, POLQ, NEIL3, ERCC6, BRCA2, BRCA1, XPC, JAG1, RPA1, POLE, ATM, and LIG1 in African American men, and POLQ, NEIL3, POLB, BRCA2, EXO1, ERCC6, ATR, RBBP8, BRCA1, ATM, JAG1, XPC, and POLE in Caucasians. We found that 89% of tumors had at least one mutation in nucleotide excision repair pathway genes in African Americans, whereas >40% of tumors had mutations in base excision repair pathway genes in Caucasians. We further identified a marginal increase in mutation rate in tumors in African Americans with increasing age. Tumors in Caucasians did not show a correlation with age, but a progressive increase in the mutation rate was observed at higher Gleason scores. Our data reveal significant differences in the molecular signatures in the DNA repairome in prostate cancer between African Americans and Caucasians. These data also have substantial implications regarding the well-known health disparities in prostate cancer, such as the higher mortality in African Americans than Caucasians.

Antimicrobial Activity of Agarwood Oil Against Multiple-Drug-Resistant (MDR) Microbes of Clinical, Food and Environmental Origin.

BACKGROUND AND OBJECTIVES: Multiple-Drug-Resistance (MDR) among bacteria is an imminent problem and alternative therapies are seen as a future abode. Agarwood Oil (AO) is described to possess antimicrobial activity besides many other medicinal utilities. This paper discusses the antimicrobial activity of AO on MDR and non-MDR strains of microbes of 69 genera isolated from clinical and non-clinical samples. METHODS AND RESULTS: In this study sensitivity of microbes was determined for conventional antimicrobials and AO using disc diffusion assay followed by determination of minimum inhibitory concentration (MIC) using agar well dilution assay. A total of 18.5% (522) strains were found sensitive to AO. Carbapenem resistant bacterial strains were more often (p, ≤0.01) resistant to antibiotics with 4.2 times more odds (99% CI, 2.99-5.90) of being MDR than carbapenem sensitive strains but no difference in their AO sensitivity was observed. However, MDR strains were more often (p, <0.001) resistant to AO than non-MDR strains. Bacteria isolated from dogs were more often sensitive to AO than those from buffaloes, human, horse, and cattle. On the other hand, bacteria from pigs were more often (p, ≤0.05) resistant to AO than bacteria from human, cattle, buffaloes, dogs, wild carnivores and birds. Oxidase positive Gram positive bacteria had 4.29 (95% CI, 2.94-6.27) times more odds to be AO sensitive than oxidase negative Gram negative bacteria. Bacillus species strains were the most sensitive bacteria to AO followed by strains of Streptococcus and Staphylococcus. The MIC of AO for different bacteria ranged from 0.01 mg/mL to > 2.56 mg/mL. CONCLUSION: The study concluded that MDR and AO resistance had a similar trend and AO may not be seen as a good antimicrobial agent against MDR strains.

Estimating RNA numbers in single cells by RNA fluorescent tagging and flow cytometry.

Estimating the statistics of single-cell RNA numbers has become a key source of information on gene expression dynamics. One of the most informative methods of in vivo single-RNA detection is MS2d-GFP tagging. So far, it requires microscopy and laborious semi-manual image analysis, which hampers the amount of collectable data. To overcome this limitation, we present a new methodology for quantifying the mean, standard deviation, and skewness of single-cell distributions of RNA numbers, from flow cytometry data on cells expressing RNA tagged with MS2d-GFP. The quantification method, based on scaling flow-cytometry data from microscopy single-cell data on integer-valued RNA numbers, is shown to readily produce precise, big data on in vivo single-cell distributions of RNA numbers and, thus, can assist in studies of transcription dynamics.

Chromosome and plasmid-borne PLacO3O1 promoters differ in sensitivity to critically low temperatures.

Temperature shifts trigger genome-wide changes in Escherichia coli's gene expression. We studied if chromosome integration impacts on a gene's sensitivity to these shifts, by comparing the single-RNA production kinetics of a PLacO3O1 promoter, when chromosomally-integrated and when single-copy plasmid-borne. At suboptimal temperatures their induction range, fold change, and response to decreasing temperatures are similar. At critically low temperatures, the chromosome-integrated promoter becomes weaker and noisier. Dissection of its initiation kinetics reveals longer lasting states preceding open complex formation, suggesting enhanced supercoiling buildup. Measurements with Gyrase and Topoisomerase I inhibitors suggest hindrance to escape supercoiling buildup at low temperatures. Consistently, similar phenomena occur in energy-depleted cells by DNP at 30 °C. Transient, critically-low temperatures have no long-term consequences, as raising temperature quickly restores transcription rates. We conclude that the chromosomally-integrated PLacO3O1 has higher sensitivity to low temperatures, due to longer-lasting super-coiled states. A lesser active, chromosome-integrated native lac is shown to be insensitive to Gyrase overexpression, even at critically low temperatures, indicating that the rate of escaping positive supercoiling buildup is temperature and transcription rate dependent. A genome-wide analysis supports this, since cold-shock genes exhibit atypical supercoiling-sensitivities. This phenomenon might partially explain the temperature-sensitivity of some transcriptional programs of E. coli.

Regulation of asymmetries in the kinetics and protein numbers of bacterial gene expression.

Genetic circuits change the status quo of cellular processes when their protein numbers cross thresholds. We investigate the regulation of RNA and protein threshold crossing propensities in Escherichia coli. From in vivo single RNA time-lapse microscopy data from multiple promoters, mutants, induction schemes and media, we study the asymmetry and tailedness (quantified by the skewness and kurtosis, respectively) of the distributions of time intervals between transcription events. We find that higher thresholds can be reached by increasing the skewness and kurtosis, which is shown to be achievable without affecting mean and coefficient of variation, by regulating the rate-limiting steps in transcription initiation. Also, they propagate to the skewness and kurtosis of the distributions of protein expression levels in cell populations. The results suggest that the asymmetry and tailedness of RNA and protein numbers in cell populations, by controlling the propensity for threshold crossing, and due to being sequence dependent and subject to regulation, may be key regulatory variables of decision-making processes in E. coli.

Four-point Peritoneal Flap Fixation in Preventing Lymphocele Formation Following Radical Prostatectomy.

BACKGROUND: Symptomatic lymphocele following radical prostatectomy (RP) and concomitant bilateral extended pelvic lymph node dissection (ePLND) has a significant impact on postoperative recovery and may sometimes require surgical intervention. OBJECTIVE: To report on the use of four-point peritoneal flap fixation (4PPFF) during RP to reduce lymphocele occurrence following PLND. DESIGN, SETTING, AND PARTICIPANTS: Between April 2010 and May 2017, 1358 patients underwent RP with concomitant bilateral ePLND. From this cohort, 193 patients who had undergone PNLD with 4PPFF were matched in a 1:1 ratio with respect to age, body mass index, initial PSA, and number of lymph nodes removed to patients who had undergone PLND without 4PPFF. INTERVENTION: 4PPFF was performed by suturing the cut end of the ventral parietal peritoneum at four points (to the anterior and lateral pelvic side wall on both sides) following PLND so that the peritoneal surface was exposed to the iliac vessels and obturator fossa. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: All patients underwent ultrasound on postoperative days 6, 28, and 90 to test for the presence of lymphocele. For univariate analysis, a χ2 test and analysis of variance were applied, as appropriate. Statistical significance was set at p<0.05, and all p values reported were two-sided. RESULTS AND LIMITATIONS: There were no significant differences between the two groups with respect to intraoperative blood loss, positive surgical margin rate, Gleason score, clinical stage, and number of positive cores. Asymptomatic lymphocele was observed in four patients (2.07%) in the 4PPFF group compared to 16 patients (8.3%) without 4PPFF (p=0.0058). Similarly, a significant difference in the incidence of symptomatic lymphocele was observed: two patients (1.03%) in the 4PPFF group versus nine patients (4.6%) without 4PPFF (p=0.0322). There were no differences in other complication rates between the two groups. The limitations of the study are its retrospective and nonrandomised nature, with postoperative follow-up based on ultrasound imaging rather than computed tomography because of ethical considerations, which could have caused observer bias. CONCLUSIONS: 4PPFF is a safe and effective procedure in preventing lymphocele occurrence in patients undergoing RP with PLND. The increase in exposure of the PLND raw area to the peritoneal surface following this procedure may aid in increased absorption of accumulating lymph fluid. Further prospective randomised multicentre studies are warranted to confirm our observations. PATIENT SUMMARY: We report on the use of a surgical technique to decrease the collection of lymphatic fluid in the abdominal cavity following lymph node removal during radical removal of the prostate gland in patients with prostate cancer. Patients undergoing this procedure had significantly better outcomes when compared to patients operated on in the conventional approach.

Tetrahydroporphyrin-tetratosylat (THPTS): A near-infrared photosensitizer for targeted and efficient photodynamic therapy (PDT) of human bladder carcinoma. An in vitro study.

BACKGROUND: Efficacy of PDT in muscle-invasive bladder cancer is hampered by low tissue penetration of most photosensitizers by short excitation wavelength. THPTS is excitable at near-infrared (760nm) allowing tissue penetration up to 15mm. We examined the cellular effects of THPTS-PDT in human bladder cancer cells. MATERIAL AND METHODS: We used four human transitional carcinoma cell lines, epithelial bladder progenitors (HBLAK) and bladder smooth muscle cells (HBSMC). We used flow cytometry to examine pharmacokinetics of THPTS, confocal laser scanning microscopy to analyze subcellular localization and production of reactive oxidative species (ROS), examined cytotoxicity and cell death pathways (qRT-PCR). RESULTS: Total uptake varied between cell lines and was significantly high in HBLAK and HBSMC. Lysosomal localization was mainly seen in cancer cells and HBLAK, while THPTS was distributed throughout the cytoplasm in HBSMC. Significant ROS production was detected 30min after THPTS-PDT. Growth arrest occurred within 4h and resulted in apoptotic and necrotic cytotoxicity after 24h. Cytotoxicity was dose-dependent and specifically high in cancer cells and HBLAK and significantly low in HBSMC. CONCLUSION: THPTS-PDT induces cellular mechanisms leading to cellular growth arrest, apoptosis and necrosis in human bladder cancer cells. These effects are only partly dependent on the total amount of THPTS uptake and rather dependent on its subcellular compartmentalization. HBSMC are hardly affected by THPTS-PDT confirming tumor specificity and safety. THPTS is a promising new photosensitizer with the unique advantage of deep tissue penetration allowing the treatment of solid tumors and warranting further animal studies.

Effects of σ factor competition are promoter initiation kinetics dependent.

In Escherichia coli, the expression of a σ factor is expected to indirectly down-regulate the expression of genes recognized by another σ factor, due to σ factor competition for a limited pool of RNA polymerase core enzymes. Evidence suggests that the sensitivity of genes to indirect down-regulation differs widely. We studied the variability in this sensitivity in promoters primarily recognized by RNAP holoenzymes carrying σ(70). From qPCR and live single-cell, single-RNA measurements of the transcription kinetics of several σ(70)-dependent promoters in various conditions and from the analysis of σ factors population-dependent models of transcription initiation, we find that, the smaller is the time-scale of the closed complex formation relative to the open complex formation, the weaker is a promoter's responsiveness to changes in σ(38) numbers. We conclude that, in E. coli, a promoter's responsiveness to indirect regulation by σ factor competition is determined by the sequence-dependent kinetics of the rate limiting steps of transcription initiation.

Long-term follow up of single-stage anterior cruciate ligament reconstruction and high tibial osteotomy and its relation with posterior tibial slope.

BACKGROUND: Open-wedge high tibial osteotomy is considered to be an effective treatment for medial compartmental osteoarthritis. It is generally admitted that tibial slope increases after open-wedge high tibial osteotomy and decreases after closing-wedge high tibial osteotomy. Young patients with anterior cruciate ligament (ACL) deficiency along with medial compartment osteoarthritis need a combined procedure of ACL reconstruction along with high tibial osteotomy to regain physiological knee kinematics and to avoid chondral damage. MATERIALS AND METHODS: We retrospectively analysed data from 30 patients who underwent arthroscopic ACL reconstruction along with medial opening-wedge osteotomy from Jan 2004 to June 2012 with a minimum follow up of 2 years. The pre-operative and post-operative posterior tibial slopes were measured. Functional outcome was analysed using clinico-radiological criteria, IKDC scoring and Lysholm score. RESULTS: Post-operative patients improved both clinically and functionally. The patients who had posterior tibial slope >5° decrease, compared to patients who had less <5° decrease, had better functional scores (IKDC and Lysholm score), which was statistically significant (p < 0.05). CONCLUSION: Our study has shown that decreasing the tibial slope >5° compared to pre-operative value has functionally favourable effect on the reconstructed ACL graft and outcome. It is known that increasing slope causes an anterior shift in tibial resting position that is accentuated under axial loads. This suggests that decreasing tibial slope may be protective in an ACL deficient knee. Hence by placing the tricortical graft posterior to midline in the opening wedge reduces the posterior tibial slope and thereby reduces the stress on the graft leading to better functional outcome.

Finite difference approximations for measure-valued solutions of a hierarchically size-structured population model.

We study a quasilinear hierarchically size-structured population model presented in [4]. In this model the growth, mortality and reproduction rates are assumed to depend on a function of the population density. In [4] we showed that solutions to this model can become singular (measure-valued) in finite time even if all the individual parameters are smooth. Therefore, in this paper we develop a first order finite difference scheme to compute these measure-valued solutions. Convergence analysis for this method is provided. We also develop a high resolution second order scheme to compute the measure-valued solution of the model and perform a comparative study between the two schemes.

Efficacy of hydroxyurea (HU) in reduction of pack red cell (PRC) transfusion requirement among children having beta-thalassemia major: Karachi HU trial (KHUT).

BACKGROUND: Packed red blood cell (PRC) transfusion with iron chelation is the mainstay of treatment for patients with beta-thalassemia major. Hemoglobin F augmentation is another approach to treat this hemoglobinopathy. This study evaluates the efficacy and safety of hydroxyurea (HU) in minimizing PRC transfusions in patients with beta-thalassemia major. METHOD: Twenty-three patients with beta-thalassemia major received HU at a mean dose of 16 mg/kg/d. The results were analyzed at the end of 24 months. Transfusion requirement during the 6 months preceding the study was considered as the control. RESULT: Twenty patients were evaluable after 24 months. The mean volume of PRC transfused was reduced from 2126.45 mL to 1489.59 mL (P<0.001). The interval between transfusions was increased by 68.7%. Grade I myelosuppression was observed in 4 patients and diarrhea in 2 patients. CONCLUSIONS: HU was found to be safe in patients with beta-thalassemia major, and resulted in reduction in the transfusion requirements and in increase of the intervals between transfusions.