Conventional vs. Hypo-Fractionated, Radiotherapy for High-Risk Prostate Cancer (PCS5), Randomized, Non-Inferiority, Phase 3 Trial: Posthoc Analysis of IMRT vs. 3D-CRT Radiation Therapy Associated Toxicities

PURPOSE/OBJECTIVE(S)

The Prostate Cancer Study number 5 (PCS5), is a multi-centric non-inferiority, phase 3, randomized controlled trial of high-risk prostate cancer patients of treated with either conventionally fractionated radiotherapy (CFRT) or hypofractionated radiotherapy (HFRT). The 7 years' pre-planned analysis showed that HFRT (68 Gy in 25 fractions) was as effective and well tolerated as CFRT (76 Gy in 38 fractions). In this posthoc analysis we aim to report the genitourinary (GU) and gastrointestinal (GI) toxicities associated with radiation therapy techniques: intensity-modulated radiotherapy (IMRT) and 3D-conformal radiotherapy (3D-CRT).

MATERIALS/METHODS

PCS5 randomized patients in a 1:1 ratio to receive either CFRT or HFRT. All patients received long term neoadjuvant, concurrent and adjuvant androgen suppression, with a median duration of 24 months. The toxicities were reported as per the Common Terminology Criteria for Adverse Events version 4. Acute toxicities were defined as presenting ≤ 180 days post-RT start and delayed > 180 days. The cumulative acute and delayed GI and GU toxicities were classified in grade groups: grade 1 or higher (G1+), G2+, and G3+. For each grade group, acute and delayed, we performed multivariable logistic regression analyses, adjusting for age, CTV volume, diabetes, fractionation (CRFT or HFRT), hypertension, and stage < T3b or ≥ T3b. For efficacy analyses cox-regression was utilized. A p-value < 0.05 was considered significant.

RESULTS

Three hundred twenty of the 329 patients enrolled in the trial were included in this posthoc analyses. The mean age was 71.4 ± 6.1 years, and the mean CTV volume (n = 219) was 47.25 ± 19.9 cc. IMRT was used in 195 (60.6%) patients and 3D-CRT in 125 (39.1%) patients. Multivariable logistic regression showed a significant difference in favor of IMRT for GI G2+ acute toxicity (OR = 0.285 [0.14-0.59]; CI: 95%; p<0.001) and GI G2+ delayed toxicity (OR = 0.202 [0.60-0.69]; CI: 95%; p = 0.01). There were no differences in G3+ GI or GU toxicities and there were no grade 4 toxicities. There were no differences in efficacy at 7 years between the two treatment technics. Outcomes for IMRT vs. 3D-CRT respectively, overall survival (81.5% vs 79.2%; HR: 0.92 [0.55-1.53]; CI: 95%; p-value: 0.74), distant metastasis free survival (90,7% vs 92.8%; HR: 1.4 [0.63-3.1]; CI: 95%; p-value: 0.42), prostate cancer mortality (95.8% vs. 92.2%; HR: 0.93 [0.32-2.67]; CI: 95%; p-value: 0.89), and biochemical failure (85.1% vs 88%; HR: 1.35 [0.72-2.52]; CI: 95%; p-value: 0.35).

CONCLUSION

This is the first phase 3 randomized controlled trial assessing the use of HFRT vs. CFRT, exclusively in high-risk prostate cancer patients. Given that our efficacy data at 7 years follow-up establishes moderate HFRT as a new standard of care and no difference between IMRT and 3D-CRT, we strongly recommend that patients who are treated with EBRT should receive IMRT, given the reduced acute and delayed grade 2 or higher GI toxicities.

Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve: A Case Report

Among other valvular heart disease Aortic stenosis (AS) is the most common in the developed world. Transcatheter Aortic Valve Replacement (TAVR) is most acceptable treatment option for patient with severely calcified aortic stenosis with high and intermediate risk group. Among several challenges, one of the main challenges is to deal with bicuspid aortic valve (BAV). Non-circular annulus, bulky leaflets leading to perivalvular leaks and risk for rupture and often very severe calcification may contribute to periprocedural strokes leading to poor clinical outcome. This case, a 68-year-old woman with a history of type 2 diabetes mellitus (DM), hypothyroidism, bicuspid aortic valve and severe aortic stenosis, bronchial asthma, who had repeatedly refused any suggestion for open heart surgery, was our volunteer candidate for TAVR. After successful TAVR the peak pressure gradient decreased from 100mmHg to 17mmHg. So, TAVR could be a viable option for highly selected patients with severe aortic stenosis and bicuspid aortic valve who have favourable anatomy.

Analysis of the different interventions scenario for programmatic measles control in Bangladesh: A modelling study

In recent years measles has been one of the most critical public health problem in Bangladesh. Although the Ministry of Health in Bangladesh employs a broad extension of measles control policies, logistical challenges exist, and there is significant doubt regarding the disease burden. Mathematical modelling of measles is considered one of the most effective ways to understand infection transmission and estimate parameters in different countries, such as Bangladesh. In this study, a mathematical modelling framework is presented to explore the dynamics of measles in Bangladesh. We calibrated the model using cumulative measles incidence data from 2000 to 2019. Also, we performed a sensitivity analysis of the model parameters and found that the contact rate had the most significant influence on the basic reproduction number R0. Four hypothetical intervention scenarios were developed and simulated for the period from 2020 to 2035. The results show that the scenario which combines enhanced treatment for exposed and infected population, first and second doses of vaccine is the most effective at rapidly reducing the total number of measles incidence and mortality in Bangladesh. Our findings also suggest that strategies that focus on a single interventions do not dramatically affect the decline in measles incidence cases; instead, those that combine two or more interventions simultaneously are the most effective in decreasing the burden of measles incidence and mortality. In addition, we also evaluated the cost-effectiveness of varying combinations of three basic control strategies including distancing, vaccination and treatment, all within the optimal control framework. Our finding suggested that combines distancing, vaccination and treatment control strategy is the most cost-effective for reducing the burden of measles in Bangladesh. Other strategies can be comprised to measles depending on the availability of funds and policymakers' choices.

Mathematical analysis of a measles transmission dynamics model in Bangladesh with double dose vaccination

Although the availability of the measles vaccine, it is still epidemic in many countries globally, including Bangladesh. Eradication of measles needs to keep the basic reproduction number less than one \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(\mathrm{i}.\mathrm{e}. \, \, {\mathrm{R}}_{0}<1)$$\end{document}(i.e.R0<1). This paper investigates a modified (SVEIR) measles compartmental model with double dose vaccination in Bangladesh to simulate the measles prevalence. We perform a dynamical analysis of the resulting system and find that the model contains two equilibrium points: a disease-free equilibrium and an endemic equilibrium. The disease will be died out if the basic reproduction number is less than one \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(\mathrm{i}.\mathrm{e}. \, \, {\mathrm{ R}}_{0}<1)$$\end{document}(i.e.R0<1), and if greater than one \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(\mathrm{i}.\mathrm{e}. \, \, {\mathrm{R}}_{0}>1)$$\end{document}(i.e.R0>1) epidemic occurs. While using the Routh-Hurwitz criteria, the equilibria are found to be locally asymptotically stable under the former condition on \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{R}}_{0}$$\end{document}R0. The partial rank correlation coefficients (PRCCs), a global sensitivity analysis method is used to compute \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{R}}_{0}$$\end{document}R0 and measles prevalence \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left({\mathrm{I}}^{*}\right)$$\end{document}I∗ with respect to the estimated and fitted model parameters. We found that the transmission rate \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(\upbeta )$$\end{document}(β) had the most significant influence on measles prevalence. Numerical simulations were carried out to commissions our analytical outcomes. These findings show that how progression rate, transmission rate and double dose vaccination rate affect the dynamics of measles prevalence. The information that we generate from this study may help government and public health professionals in making strategies to deal with the omissions of a measles outbreak and thus control and prevent an epidemic in Bangladesh.

Murine muscle stem cell response to perturbations of the neuromuscular junction are attenuated with aging

During aging and neuromuscular diseases, there is a progressive loss of skeletal muscle volume and function impacting mobility and quality of life. Muscle loss is often associated with denervation and a loss of resident muscle stem cells (satellite cells or MuSCs); however, the relationship between MuSCs and innervation has not been established. Herein, we administered severe neuromuscular trauma to a transgenic murine model that permits MuSC lineage tracing. We show that a subset of MuSCs specifically engraft in a position proximal to the neuromuscular junction (NMJ), the synapse between myofibers and motor neurons, in healthy young adult muscles. In aging and in a mouse model of neuromuscular degeneration (Cu/Zn superoxide dismutase knockout - Sod1-/-), this localized engraftment behavior was reduced. Genetic rescue of motor neurons in Sod1-/- mice reestablished integrity of the NMJ in a manner akin to young muscle and partially restored MuSC ability to engraft into positions proximal to the NMJ. Using single cell RNA-sequencing of MuSCs isolated from aged muscle, we demonstrate that a subset of MuSCs are molecularly distinguishable from MuSCs responding to myofiber injury and share similarity to synaptic myonuclei. Collectively, these data reveal unique features of MuSCs that respond to synaptic perturbations caused by aging and other stressors.

Engineered Heterochronic Parabiosis in 3D Microphysiological System for Identification of Muscle Rejuvenating Factors

Exposure of aged mice to a young systemic milieu revealed remarkable rejuvenation effects on aged tissues, including skeletal muscle. Although some candidate factors have been identified, the exact identity and the underlying mechanisms of putative rejuvenating factors remain elusive, mainly due to the complexity of in vivo parabiosis. Here, we present an in vitro muscle parabiosis system that integrates young- and old-muscle stem cell vascular niche on a three-dimensional microfluidic platform designed to recapitulate key features of native muscle stem cell microenvironment. This innovative system enables mechanistic studies of cellular dynamics and molecular interactions within the muscle stem cell niche, especially in response to conditional extrinsic stimuli of local and systemic factors. We demonstrate that vascular endothelial growth factor (VEGF) signaling from endothelial cells and myotubes synergistically contribute to the rejuvenation of the aged muscle stem cell function. Moreover, with the adjustable on-chip system, we can mimic both blood transfusion and parabiosis and detect the time-varying effects of anti-geronic and pro-geronic factors in a single organ or multi-organ systems. Our unique approach presents a complementary in vitro model to supplement in vivo parabiosis for identifying potential anti-geronic factors responsible for revitalizing aging organs.

Association of Estimated GFR (By MDRD) with the Carotid Intima Media Thickness (CIMT) in Different Stages of CKD among Patients with Type 2 Diabetes Mellitus

Most of the mortalities among Diabetic Nephropathy patients are cardiovascular, if we identify the risk factor, measures can be taken to prevent it. Hence an objective was set to evaluate the association between carotid artery intima media thickness (CIMT) with eGFR in patients of CKD stage III, IV and V among patients with type 2 diabetes mellitus; also, correlation with age, BMI, lipid profile. This cross-sectional, observational study was performed in 70 patients in different stages of CKD in Diabetic Patients selected by Inclusion Criteria (Diabetic nephropathy patients with stages III, IV, V and exclusion Criteria (Acute kidney injury, History of carotid surgery, Patients of MI and stroke). This study was performed in Department of Nephrology, Dhaka Medical College in collaboration with the Department of Radiology and Imaging, laboratory of Department of Biochemistry and Department of Microbiology at Dhaka Medical College Hospital (By standard method in laboratory) from 1st January 2016 to 31st December 2016. eGFR was measured by MDRD formula and the CIMT was measured using an ultrasonographic examination. The mean CIMT was 0.9±0.21mm, and 62.9% of the subjects showed IMT thickening (≥1mm). The carotid IMT elevated significantly with the stage progression of CKD (Overall eGFR mean 28.8±14.5mL/min/1.73m² in CIMT<1mm with range from 6 to 54 and 9.1±9.0mL/min/1.73m² in CIMT ≥1mm with range from 3 to 32 (p=0.001). The eGFR was significantly lower in the patients with CIMT thickening than those without CIMT thickening. eGFR was also significantly associated with CKD stages (p=0.001), serum creatinine (p=0.001), BMI (r = -0.330, p=0.005), and negatively associated with age group, duration of hypertension, smoking. However, the CIMT was not significantly different among the patients at different stages of diabetic nephropathy (r = -0.172, p=156) and age group. It has been concluded that the mean CIMT was markedly high in patients with CKD compared to normal expected value. This study showed a relationship between the CIMT and the renal parameters as eGFR and the stages of diabetic nephropathy with a confirm association between the CIMT and diabetic macroangiopathy.

Single-walled carbon nanohorns modulate tenocyte cellular response and tendon biomechanics

Subfailure ligament and tendon injury remain a significant burden to global healthcare. Here, we present the use of biocompatible single-walled carbon nanohorns (CNH) as a potential treatment for the repair of sub-failure injury in tendons. First, in vitro exposure of CNH to human tenocytes revealed no change in collagen deposition but a significant decrease in cell metabolic activity after 14 days. Additionally, gene expression studies revealed significant downregulation of collagen Types I and III mRNA at 7 days with some recovery after 14 days of exposure. Biomechanical tests with explanted porcine digitorum tendons showed the ability of CNH suspensions to modulate tendon biomechanics, most notably elastic moduli immediately after treatment. in vivo experiments demonstrated the ability of CNH to persist in the damaged matrix of stretch-injured Sprague Dawley rat Achilles tendon but not significantly modify tendon biomechanics after 7 days of treatment. Although these results demonstrate the early feasibility of utility of CNH as a potential modality for tendon subfailure injury, additional work is needed to further validate and ensure clinical efficacy.

Co-delivery of Wnt7a and muscle stem cells using synthetic bioadhesive hydrogel enhances murine muscle regeneration and cell migration during engraftment

Skeletal muscle possesses efficient ability to regenerate upon minor injuries, but its capacity to regenerate is severely compromised with traumatic injuries and muscle-associated diseases. Recent evidence suggests that skeletal muscle regeneration can be enhanced by transplantation of muscle satellite cells (MuSCs) or treatment with pro-myogenic factors, such as Wingless-type MMTV Integrated 7a (Wnt7a) protein. Although direct intramuscular injection is the simplest method to deliver MuSCs and Wnt7a for regenerative therapy, direct injections are not viable in many clinical cases where structural integrity is severely compromised. To address this challenge, we evaluated the feasibility of co-delivering pro-myogenic factors, such as Wnt7a, and MuSCs using a synthetic poly(ethylene glycol) (PEG)-based hydrogel to the affected skeletal muscles. The Wnt7a release rate can be controlled by modulating the polymer density of the hydrogel, and this release rate can be further accelerated through the proteolytic degradation of the hydrogel. Treating cryo-injured tibialis anterior (TA) muscles with Wnt7a-loaded hydrogels resulted in an improved regenerative response by day 14, measured by increased muscle fiber cross-sectional area, bulk TA mass, and the number of Pax7⁺ MuSCs at the injury site, compared to the TA muscles treated with Wnt7a-free hydrogels. Co-delivery of Wnt7a and primary MuSCs using the synthetic hydrogel to the cryo-injured TA muscles significantly increased cellular migration during the engraftment process. This work provides a synthetic biomaterial platform for advancing treatment strategies of skeletal muscle conditions where direct intramuscular injection may be challenging. Finally, the current outcomes establish an important foundation for future applications in treating severe muscle trauma and diseases, where the endogenous repair capacity is critically impaired. STATEMENT OF SIGNIFICANCE: Skeletal muscle injuries and diseases cause debilitating health consequences, including disability and diminished quality of life. Treatment using protein and stem cell-based therapeutics may help regenerate the affected muscles, but direct intramuscular injection may not be feasible in severe muscle injuries due to the gravely damaged tissue structure. In chronic muscle diseases, such as Duchenne muscular dystrophy, local treatment of the diaphragm, a muscle critical for respiration, may be necessary but direct injection is difficult due to its thin dimensions. To address this challenge, this work presents a synthetic and bioactive muscle "patch" that enables concurrent administration of proteins and muscle stem cells for accelerated muscle healing.

Critical Limb Ischemia Induces Remodeling of Skeletal Muscle Motor Unit, Myonuclear-, and Mitochondrial-Domains

Critical limb ischemia, the most severe form of peripheral artery disease, leads to extensive damage and alterations to skeletal muscle homeostasis. Although recent research has investigated the tissue-specific responses to ischemia, the role of the muscle stem cell in the regeneration of its niche components within skeletal muscle has been limited. To elucidate the regenerative mechanism of the muscle stem cell in response to ischemic insults, we explored cellular interactions between the vasculature, neural network, and muscle fiber within the muscle stem cell niche. Using a surgical murine hindlimb ischemia model, we first discovered a significant increase in subsynaptic nuclei and remodeling of the neuromuscular junction following ischemia-induced denervation. In addition, ischemic injury causes significant alterations to the myofiber through a muscle stem cell-mediated accumulation of total myonuclei and a concomitant decrease in myonuclear domain size, possibly to enhance the transcriptional and translation output and restore muscle mass. Results also revealed an accumulation of total mitochondrial content per myonucleus in ischemic myofibers to compensate for impaired mitochondrial function and high turnover rate. Taken together, the findings from this study suggest that the muscle stem cell plays a role in motor neuron reinnervation, myonuclear accretion, and mitochondrial biogenesis for skeletal muscle regeneration following ischemic injury.

Determination of a Critical Size Threshold for Volumetric Muscle Loss in the Mouse Quadriceps

IMPACT STATEMENT

The goal of this study was to determine the threshold for a critically sized, nonhealing muscle defect by characterizing key components in the balance between fibrosis and regeneration as a function of injury size in the mouse quadriceps. There is currently limited understanding of what leads to a critically sized muscle defect and which muscle regenerative components are functionally impaired. With the substantial increase in preclinical VML models as testbeds for tissue engineering therapeutics, defining the critical threshold for VML injuries will be instrumental in characterizing therapeutic efficacy and potential for subsequent translation.

Synthetic matrix enhances transplanted satellite cell engraftment in dystrophic and aged skeletal muscle with comorbid trauma

Muscle satellite cells (MuSCs) play a central role in muscle regeneration, but their quantity and function decline with comorbidity of trauma, aging, and muscle diseases. Although transplantation of MuSCs in traumatically injured muscle in the comorbid context of aging or pathology is a strategy to boost muscle regeneration, an effective cell delivery strategy in these contexts has not been developed. We engineered a synthetic hydrogel-based matrix with optimal mechanical, cell-adhesive, and protease-degradable properties that promotes MuSC survival, proliferation, and differentiation. Furthermore, we establish a biomaterial-mediated cell delivery strategy for treating muscle trauma, where intramuscular injections may not be applicable. Delivery of MuSCs in the engineered matrix significantly improved in vivo cell survival, proliferation, and engraftment in nonirradiated and immunocompetent muscles of aged and dystrophic mice compared to collagen gels and cell-only controls. This platform may be suitable for treating craniofacial and limb muscle trauma, as well as postoperative wounds of elderly and dystrophic patients.

Seroprevalence of Leptospira infection in selected rural and urban areas of Bangladesh by rLipL32 based ELISA

Background and objectives: Leptospirosis is a zoonotic infection with worldwide distribution caused by the Leptospira species and predominant in the tropical and subtropical regions. Information on leptospirosis in Bangladesh is limited. The present study was designed to detect anti-leptospiral antibodies in human serum samples in Bangladeshi population by developing an in-house ELISA using recombinant LipL32 (rLipL32) antigen. The study was conducted from April 2014 to December 2014.Method: Healthy individuals from two rural areas and fever cases from one urban healthcare center were enrolled in the study. Rural health centers were located at Sonargoan and Bajitpur sub-district (Upozilla) of Narayaganj and Kishorganj districts. Sonargoan health center is located 26 km south-east and Bajitpur is located 71 km north-east of Dhaka city. About 1-2 ml of blood was collected with aseptic measure and serum was separated and stored at -200C until used. Anti-leptospiral IgG antibody was determined by recombinant LipL32 (rLipL32) antigen based indirect enzyme linked immunosorbent assay (ELISA). Seropositive cases were further confirmed by commercial Leptospira IgG ELISA.Results: The study included 250 febrile cases and 376 healthy individuals from urban and rural areas, respectively. Out of total 626 study population, anti-LipL32 specific IgG antibody was detected in 70 individuals (11.2%). The rate of positivity of anti-LipL32 antibody among the healthy individuals from rural area was 10.6% while the rate was 12.0% in urban febrile population. The rate of positivity in rural and urban population was not significantly (p>0.05) different. Among the urban population, the rate of seropositivity was 9.1% and 16.4% in 21- 40 yrs and above 40 years age group respectively while the rate was 7.2% and 14.0% in rural population respectively. Out of 70 seropositive cases detected by LipL32 ELISA, 65 (92.9%) were positive by commercial ELISA.Conclusion: The present study has revealed that leptospirosis is prevalent in Bangladesh and should be looked for in febrile and clinically suspected cases. The study has also demonstrated that rLipL32 protein may be used as a candidate antigen for the serodiagnosis of leptospirosis.IMC J Med Sci 2017; 11(2): 50-55

Alpha-Glucosidase Enzyme Biosensor for the Electrochemical Measurement of Antidiabetic Potential of Medicinal Plants

A biosensor for measuring the antidiabetic potential of medicinal plants was developed by covalent immobilization of α-glucosidase (AG) enzyme onto amine-functionalized multi-walled carbon nanotubes (MWCNTs-NH2). The immobilized enzyme was entrapped in freeze-thawed polyvinyl alcohol (PVA) together with p-nitrophenyl-α-D-glucopyranoside (PNPG) on the screen-printed carbon electrode at low pH to prevent the premature reaction between PNPG and AG enzyme. The enzymatic reaction within the biosensor is inhibited by bioactive compounds in the medicinal plant extracts. The capability of medicinal plants to inhibit the AG enzyme on the electrode correlates to the potential of the medicinal plants to inhibit the production of glucose from the carbohydrate in the human body. Thus, the inhibition indicates the antidiabetic potential of the medicinal plants. The performance of the biosensor was evaluated to measure the antidiabetic potential of three medicinal plants such as Tebengau (Ehretis laevis), Cemumar (Micromelum pubescens), and Kedondong (Spondias dulcis) and acarbose (commercial antidiabetic drug) via cyclic voltammetry, amperometry, and spectrophotometry. The cyclic voltammetry (CV) response for the inhibition of the AG enzyme activity by Tebengau plant extracts showed a linear relation in the range from 0.423-8.29 μA, and the inhibition detection limit was 0.253 μA. The biosensor exhibited good sensitivity (0.422 μA/mg Tebengau plant extracts) and rapid response (22 s). The biosensor retains approximately 82.16 % of its initial activity even after 30 days of storage at 4 °C.

Cross-Talk Between Human Tenocytes and Bone Marrow Stromal Cells Potentiates Extracellular Matrix Remodeling In Vitro

Tendon and ligament (T/L) pathologies account for a significant portion of musculoskeletal injuries and disorders. Tissue engineering has emerged as a promising solution in the regeneration of both tissues. Specifically, the use of multipotent human mesenchymal stromal cells (hMSC) has shown great promise to serve as both a suitable cell source for tenogenic regeneration and a source of trophic factors to induce tenogenesis. Using four donor sets, we investigated the bidirectional paracrine tenogenic response between human hamstring tenocytes (hHT) and bone marrow-derived hMSC. Cell metabolic assays showed that only one hHT donor experienced sustained notable increases in cell metabolic activity during co-culture. Histological staining confirmed that co-culture induced elevated collagen protein levels in both cell types at varying time-points in two of four donor sets assessed. Gene expression analysis using qPCR showed the varied up-regulation of anabolic and catabolic markers involved in extracellular matrix maintenance for hMSC and hHT. Furthermore, analysis of hMSC/hHT co-culture secretome using a reporter cell line for TGF-β, a potent inducer of tenogenesis, revealed a trend of higher TGF-β bioactivity in hMSC secretome compared to hHT. Finally, hHT cytoskeletal immunostaining confirmed that both cell types released soluble factors capable of inducing favorable tenogenic morphology, comparable to control levels of soluble TGF-β1. These results suggest a potential for TGF-β-mediated signaling mechanism that is involved during the paracrine interplay between the two cell types that is reminiscent of T/L matrix remodeling/turnover. These findings have significant implications in the clinical use of hMSC for common T/L pathologies.

Effective spatially fractionated GRID radiation treatment planning for a passive grid block

OBJECTIVE

To commission a grid block for spatially fractionated grid radiation therapy (SFGRT) treatments and describe its clinical implementation and verification through the record and verify (R&V) system.

METHODS

SFGRT was developed as a treatment modality for bulky tumours that cannot be easily controlled with conventionally fractionated radiation. Treatment is delivered in the form of open-closed areas. Currently, SFGRT is performed by either using a commercially available grid block or a multileaf collimator (MLC) of a linear accelerator. In this work, 6-MV photon beam was used to study dosimetric characteristics of the grid block. We inserted the grid block into a commercially available treatment planning system (TPS), and the feasibility of delivering such treatment plans on a linear accelerator using a R&V system was verified. Dose measurements were performed using a miniature PinPoint(TM) ion chamber (PTW, Freiburg, Germany) in a water phantom and radiochromic film within solid water slabs. PinPoint ion chamber was used to measure the output factors, percentage depth dose (PDD) curves and beam profiles at two depths, depth of maximum dose (zmax) and 10 cm. Film sheets were used to measure dose profiles at zmax and 10-cm depth.

RESULTS

The largest observed percentage difference between output factors for the grid block technique calculated by the TPS and measured with the PinPoint ion chamber was 3.6% for the 5 × 5-cm(2) field size. Relatively significant discrepancies between measured and calculated PDD values appear only in the build-up region, which was found to amount to <4%, while a good agreement (differences <2%) at depths beyond zmax was observed. Dose verification comparisons performed between calculated and measured dose distributions were in clinically acceptable agreements. When comparing the MLC-based with the grid block technique, the advantage of treating large tumours with a single field reduces treatment time by at least 3-5 times, having significant impact on patient throughput.

CONCLUSION

The proposed method supports and helps to standardize the clinical implementation of the grid block in a safer and more accurate way.

ADVANCES IN KNOWLEDGE

This work describes the method to implement treatment planning for the grid block technique in radiotherapy departments.

Quorum-sensing autoinducers resuscitate dormant Vibrio cholerae in environmental water samples

Cholera epidemics have long been known to spread through water contaminated with human fecal material containing the toxigenic bacterium Vibrio cholerae. However, detection of V. cholerae in water is complicated by the existence of a dormant state in which the organism remains viable, but resists cultivation on routine bacteriological media. Growth in the mammalian intestine has been reported to trigger "resuscitation" of such dormant cells, and these studies have prompted the search for resuscitation factors. Although some positive reports have emerged from these investigations, the precise molecular signals that activate dormant V. cholerae have remained elusive. Quorum-sensing autoinducers are small molecules that ordinarily regulate bacterial gene expression in response to cell density or interspecies bacterial interactions. We have found that isolation of pathogenic clones of V. cholerae from surface waters in Bangladesh is dramatically improved by using enrichment media containing autoinducers either expressed from cloned synthase genes or prepared by chemical synthesis. These results may contribute to averting future disasters by providing a strategy for early detection of V. cholerae in surface waters that have been contaminated with the stools of cholera patients or asymptomatic infected human carriers.

Clinicopathological stages of carcinoma breast patient

Carcinoma of breast is the second most common cancer among women next to uterine cervical cancer in Bangladesh. It was well established that 5 years survival rates greatly vary among the different stages of carcinoma of breast disease. The study was carried out to see the stages of presentation of carcinoma of breast patient to a tertiary level hospital attended first time for medical help as well as to find out the factors responsible for the late (advanced) stage presentation. This descriptive type of cross sectional study was carried out in the department of surgery, Mymensingh Medical College and Hospital (MMCH) during the period of May 2010 to April 2011. A total of 110 cases admitted with carcinoma breast diagnosed by means of FNAC positive or suspicious findings were selected purposively during the study period. Patients were staged initially according to the TNM staging system by through clinical examination as well as final clinicopathological stages were done after histopathological examination of the resected specimen (breast with or without axillary lymphnode) in resectable cases. Among the advanced stage presentation, attempts were made to find out the factors responsible for advanced stage of the disease. The results showed that carcinoma of breast predominantly a disease of female and comparatively younger age group 40-49 years affected mostly in 40.9% cases with a mean age of 44.02 ± 10.32 years. Premenopausal lady mostly affected in 63.6% cases. Majority of patients presented in advanced stage of the disease in 62.8% cases. Multiple factors were observed responsible for the advanced stage of the disease - among them delay in hospital presentation, poor socioeconomic condition and illiteracy have found to be associated which were statistically significant (p<0.001). It was needed for mass awareness program against the breast cancer in our society. Necessary steps should be taken for the initiation of breast self examination (BSE) to patients and clinical breast examination (CBE) to health care providers.

Pattern of malignancy in clinically solitary thyroid nodule

Solitary thyroid nodule (STN) is a common thyroid disorder. Clinically recognized thyroid carcinoma constitutes less than 1% of human malignant tumours. The risk of malignancy in solitary thyroid nodule is greater than other thyroid swelling. The risk of malignancy in generalized thyroid swelling is about 3% and in solitary thyroid nodule it is about 15%. This study was carried out in Surgery and ENT Department, Mymensingh Medical college Hospital from November 2008 to October 2009 to see pattern of malignancy in clinically solitary thyroid nodule. Total 108 patients of STN was included in this study, majority of the patients were within 20-39 years age group with female predominance. In addition to thyroid swelling some patients presented with other symptoms like cervical lymphadenopathy in 6(5.56%), dysphagia 2(1.85%), hoarseness of voice 2(1.85%) and metastatic lesion in bone 1(0.92%) cases. Among 108 cases of solitary thyroid nodule only 19 cases were malignant. Patients with malignant lesion presented with shorter duration of symptoms. Out of 19 malignant cases 6(31.58%) cases presented with features of metastasis. Malignancy was more predominant in male (25.00%) than the female (14.47%) in STN. Out of 19 malignant cases, 12(63.16%) were papillary carcinoma, 5(26.31%) were follicular carcinoma and 2(10.53%) cases were medullary carcinoma. Study showed significant difference (p<0.01) between papillary & follicular carcinoma and significant difference (p<0.001) between papillary & medullary carcinoma. Papillary carcinoma was most common among all thyroid malignancies in patients with solitary thyroid nodule.

A young lady with secondary tuberculosis of breast

Tuberculosis of breast is an extremly rare form of extrapulmonary tuberculosis even in endemic area like Bangladesh and the incidence is 0.25-4.5% of all breast lesions. The diagnosis is difficult because of nonspecific clinical, radiological and histopathological findings. Very often biopsy specimens are inadequate and microscopy or culture is negative. It is usually suspected in a multiparous woman who may be immunocompromised. We report a case of breast tuberculosis in a 26 years old multiparous lady who previously present with two times attack of right sided breast lump and then diagnosed as a case of breast abscess and treated by incision and drainage with antibiotics in a nearby local hospital. During her third time attack she admitted into Mymensingh Medical College Hospital with right sided breast lump with multiple discharging sinuses for one month. Biopsy was taken from the lump and sinus tract and histopathological report confirmed the diagnosis as a case of tuberculosis of breast. Her X-ray chest showed tubercular lesion in lungs. So this is a case of secondary breast tuberculosis. This case highlights how difficult is the diagnosis of a case of breast tuberculosis for which the patient may require even mastectomy at very late case. So this case is reported.

Drug Response Indicator Test (DRIT) as a predictive test for treatment outcomes in advanced breast cancer patients (ABC)

1119

Background: There are limited options for selecting an optimal treatment regimen for ABC patients (pts). DRIT is a platform technology that provides a profile of a patient's tumor's sensitivity or resistance to commonly used chemotherapeutic, hormonal, or biological agents as a basis for individualized anticancer treatment approach. DRIT may allow physicians to choose more effective drug treatments before initiation of therapy and improve the efficacy and toxicity profile of cancer therapies. Methods: DRIT analysis is based on fluorescent dye-labeled monoclonal antibody staining followed by computer-assisted microscopy to quantitatively measure expression levels in tumor sections. The interpretation of DRI expression levels results in classification of tumors as sensitive or resistant to treatment with a mechanistically related drug. This study utilized the following drug/DRI combinations: hormonal therapy/estrogen receptor; capecitabine/thymidylate synthase; docetaxel, paclitaxel, abraxane/β-tubulin isoform III; trastuzumab/HER-2; gemcitabine/ribonucleotide reductase. DRIT was performed on the tumor tissue of consented study participants with ABC who were then deemed to be sensitive or resistant to a given agent/agents. We then analyzed retrospectively clinical treatment outcomes (clinically sensitive to therapy defined as-stable disease+partial response+complete response or resistant to therapy-no response to therapy) for 91 treatment interventions in 71 pts with the DRIT tissue data. Results: We found that the DRIT sensitivity was 0.99, with specificity of 0.59, positive predictive value of 0.88, negative predictive value of 0.93 and overall predictive value of 88% for treatment outcomes for this cohort of ABC pts. Conclusions: This study suggests that DRIT can provide more accurate prediction of treatment outcomes for ABC pts than the standard of care approach and therefore has a potential to avoid unnecessary ineffective drug treatment exposure. Prospective study in ABC pts is currently conducted at the UMGCC.

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Comparative analysis of the post-lumpectomy target volume versus the use of pre-lumpectomy tumor volume for early stage breast cancer: implications for the future

Abstract #5134

Purpose: Accelerated partial breast irradiation (APBI) is increasingly being utilized for the treatment of early stage breast cancer. Planning target volume (PTV) generation with this approach is based on the post-lumpectomy cavity volume (post-LPC) and is often associated with treatment of large amounts of normal breast tissue which can result in patient ineligibility for external beam APBI (EB-APBI). In malignancies such as soft tissue sarcomas, neoadjuvant radiation therapy (RT) has been shown to be associated with smaller volumes of tissue irradiated compared to adjuvant RT. However, neoadjuvant RT has not been attempted in the setting of APBI. We hypothesized that a PTV generation based on an expansion of the pre-lumpectomy (pre-LP) intact tumor volume would result in a significant reduction in the volume of irradiated normal breast tissue compared to the current approach of using the post-LPC. We further hypothesize that the use of EB-APBI utilizing the pre-LP tumor will result in greater patient eligibility for APBI.&#x2028; Materials and Methods: 40 patients with 41 early stage breast cancers previously treated with breast conserving lumpectomy and RT were analyzed. Pre-operative imaging and pathology reports were used to determine a pre-LP tumor volume. A sphere, the diameter of which was the largest determined radiographic dimension, representing the pre-LP tumor volume was placed in the center of the previously contoured and treated lumpectomy cavity. PTVs were developed for the pre-LP tumor volume and the post-LPC volume as per the NSABP-B39 protocol guidelines. The pre-LP and post-LPC PTV volumes were compared. Suitability for APBI was analyzed using criteria set forth by NSABP-B39 guidelines.&#x2028; Results: For all patients, the pre-LP PTV was smaller than the post-LPC PTV. The median volume for the pre and post-LPC PTVs were 93 cc (range 24 – 570 cc) and 250 cc (range 45 – 879 cc), respectively. Paired t-test analysis demonstrated the pre-LP PTV to be significantly smaller than the post-LPC PTV, p &lt; 0.001. The average difference between pre-LP and post-LPC PTVs represented 173 cc (range 21 – 482 cc) or 18% (range 3 - 42%) of the whole breast volume. Based on our analysis, only 3 of 41 cases were ineligible for EB-APBI when using the pre-LP tumor volume, (2 based on pathologic criteria and 1 based on dose/volume constraints) while 13 of 41 cases were ineligible when using the post-LPC PTV (2 based on pathologic criteria and 11 based on dose/volume constraints).&#x2028; Conclusion: PTVs based on the pre-LP tumor expansion are likely to be associated with a significantly reduced amount of normal breast tissue irradiated compared to post-LPC PTVs potentially leading to improved breast cosmesis, decreased dose to critical structures and decreased toxicities. Additionally, eligibility for EB-APBI would potentially increase if administered in the pre-lumpectomy setting. The findings from this study support future investigation as to the implications and feasibility of neoadjuvant APBI.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5134.