Tinospora cordifolia modulates the seminal parameters, leakage of intracellular enzymes and seminal antioxidants in equilibrated and cryopreserved semen of Sahiwal bulls.

The present study was undertaken to assess the effects of stem extract of Tinospora cordifolia (Giloy or Guduchi) in the semen extender on seminal parameters, leakage of intracellular enzymes and antioxidants in semen of Sahiwal bull. A total of 48 ejaculates from four bulls were selected for the study. Spermatozoa of 25 × 106 were incubated in 100, 300 and 500 µg of stem extract of Guduchi as Gr II, III and IV, respectively, and pre-freeze and post-thaw semen samples were analysed for seminal parameters [motility, viability, total sperm abnormality (TSA), plasma membrane integrity (PMI) and acrosomal integrity (AcI)], intracellular enzymes [aspartate aminotransferase (AST) and lactate dehydrogenase (LDH)] and seminal antioxidants [superoxide dismutase (SOD) and catalase] in comparison with an untreated control group (Gr I). The results revealed that stem extract-treated semen had significantly (p < .05) higher motility, viability, PMI, AcI, SOD and catalase and had significantly (p < .05) lower TSA, AST and LDH compared to those in untreated control group at pre-freeze and post-thaw stages. Semen treated with 100 µg stem extract/25 × 106 spermatozoa had significantly (p < .05) higher motility, viability, PMI, AcI, SOD and catalase and had significantly (p < .05) lower TSA, AST and LDH compared to those in control, 300- and 500-µg-treated groups at pre-freeze and post-thaw stages. Further, these seminal parameters and antioxidants were showing decreasing trend and TSA and leakage of intracellular enzymes were showing increasing trend from Gr II to Gr IV at pre-freeze and post-thaw stages. Thus, 100 µg/25 × 106 spermatozoa were optimum or suitable dose for cryopreservation of Sahiwal bull semen. The study concluded that T. cordifolia stem extract 100 µg/25 × 106 spermatozoa in the semen extender can be effectively utilized to reduce the oxidative stress and improve the pre-freeze and post-thaw seminal parameters in Sahiwal bull. However, further studies on effects of different concentrations of stem extract on in vitro or in vivo fertility trials are to be conducted to assess the impact of the stem extract supplementation in the semen extender on field pregnancy outcomes in bovine species.

MicroRNA Regulation of Airway Inflammation and Airway Smooth Muscle Function: Relevance to Asthma.

Genetic and environmental factors contribute to the onset and severity of asthma. Molecular pathogenesis of asthma involves changes in gene expression by a variety of inflammatory mediators acting in autocrine and paracrine fashion on effector cells of the airways. Transcriptional regulation of gene expression in resident airway cells has been studied extensively. However, protein function in a target cell can be regulated at multiple levels starting from transcription followed by post-transcription, translation, and post-translation steps. In this context, small noncoding RNAs known as microRNAs (miRNAs) have evolved as one of the key regulators of gene expression post-transcriptionally. Most importantly, miRNA expression is dynamic in nature and can be regulated by a variety of external stimuli. Altered expression of individual or a group of miRNAs is thought to contribute to human diseases. Recent studies have implicated differential expression of miRNAs in the lungs during inflammation. Most importantly, advanced biochemical and molecular tools could be used to manipulate miRNA expression thereby effecting functional changes in target cells and organ systems. This review summarizes the current understanding of miRNA in the regulation of airway function in health and disease, and highlights the potential clinical utility of mRNAs as biomarkers of airway diseases and as potential therapeutic targets.

Antibacterial action of penicillin against Mycobacterium avium complex.

INTRODUCTION: ß-lactam antibiotics are promising treatments for Mycobacterium avium complex (MAC) lung disease. We hypothesized that benzylpenicillin has efficacy against MAC. METHODS: Benzylpenicillin lung concentration-time profiles of seven doses in three dosing schedules were administered for 28 days using the hollow fiber system model of intracellular MAC (HFS-MAC). Data were analyzed using the inhibitory sigmoid maximal effect (Emax) model for each sampling day, while two ordinary differential equations (ODEs) were used for the wild-type and penicillin-resistant mutants. RESULTS: Benzylpenicillin killed >2.1 log10 colony-forming unit (CFU)/mL below Day 0, better than azithromycin, ethambutol, and rifabutin. Efficacy was terminated by acquired resistance. Sigmoid Emax parameter estimates significantly differed between sampling days and were a poor fit. However, ODE model parameter estimates vs. exposure were a better fit. The exposure mediating Emax was 84.6% (95% CI 76.91-82.98) of time concentration exceeded the minimum inhibitory concentration (MIC). In Monte Carlo experiments, 24 million international units of benzylpenicillin continuous infusion achieved the target exposure in lungs of >90% of 10,000 subjects until an MIC of 64 mg/L, designated the susceptibility breakpoint. CONCLUSIONS: Benzylpenicillin demonstrated a better bactericidal effect against MAC than guideline-recommended drugs before the development of resistance. Its role in combination therapy with other drugs with better efficacy than guideline-recommended drugs should be explored.

INTRODUCTION: Les ß-lactamines représentent des options thérapeutiques prometteuses pour le traitement de la maladie pulmonaire à complexe Mycobacterium avium (MAC). Notre hypothèse suggère que la benzylpénicilline pourrait être efficace contre cette maladie pulmonaire causée par M. avium. MÉTHODES: Les concentrations pulmonaires de benzylpénicilline ont été mesurées à différents moments après l'administration de sept doses selon trois schémas différents pendant 28 jours dans le modèle de MAC intracellulaire du système de fibres creuses (HFS-MAC). Les données ont été analysées en utilisant un modèle sigmoïde inhibiteur à effet maximal (Emax) pour chaque jour d'échantillonnage, et deux équations différentielles ordinaires (ODE) ont été appliquées pour les souches sauvages et les mutants résistants à la pénicilline. RÉSULTATS: La benzylpénicilline a provoqué une réduction de >2,1 log10 CFU/mL en dessous du jour 0, surpassant ainsi l'azithromycine, l'éthambutol et la rifabutine. Cependant, son efficacité a été compromise par l'émergence d'une résistance. Les estimations des paramètres de l'Emax sigmoïde ont montré des différences significatives entre les jours d'échantillonnage et étaient mal ajustées. En revanche, les estimations des paramètres du modèle ODE en fonction de l'exposition étaient plus précises. L'exposition médiane de l'Emax était de 84,6% (IC à 95% 76,91­82,98) du temps où la concentration dépassait la concentration minimale inhibitrice (MIC, pour l'anglais « minimum inhibitory concentration ¼). Dans les simulations de Monte Carlo, une perfusion continue de 24 millions d'unités internationales de benzylpénicilline a permis d'atteindre l'exposition cible dans les poumons de plus de 90% des 10 000 sujets, jusqu'à ce qu'une MIC de 64 mg/L soit atteinte, indiquant ainsi le point de rupture de la sensibilité. CONCLUSIONS: La benzylpénicilline a montré une efficacité bactéricide supérieure contre le MAC par rapport aux médicaments recommandés par les lignes directrices avant l'émergence de la résistance. Il convient d'explorer son utilisation dans une thérapie combinée avec des médicaments plus performants que ceux recommandés par les lignes directrices.

An Audit for Radiotherapy Planning and Treatment Errors From a Low-Middle-Income Country Centre.

AIMS: To report the findings of an audit for radiotherapy errors from a low-middle-income country (LMICs) centre. This would serve as baseline data for radiotherapy error rates, their severity and causes, in such centres where modern error reporting and learning processes still do not exist. MATERIALS AND METHODS: A planned cross-sectional weekly audit of electronic radiotherapy charts at the radiotherapy planning and delivery step for all patients treated with curative intent was conducted. Detailed analysis was carried out to determine the step of origin of error, time and contributing factors. They were graded as per indigenous institutional (TMC) radiotherapy error grading (TREG) system and the contributing factors identified were prioritised using the product of frequency, severity and ease of detection. RESULTS: In total, 1005 consecutive radically treated patients' charts were audited, 67 radiotherapy errors affecting 60 patients, including 42 incidents and 25 near-misses were identified. Transcriptional errors (29%) were the most common type. Most errors occurred at the time of treatment planning (59.7%), with "plan information transfer to the radiation oncology information system" being the most frequently affected sub-step of the radiotherapy process (47.8%). More errors were noted at cobalt units (52/67; 77.6%) than at linear accelerators. Trend analysis showed an increased number of radiotherapy incidents on Fridays and near-misses on Mondays. Trend for increased radiotherapy errors noted in the evening over other shifts. On severity grading, most of the errors (54/60; 90%) were clinically insignificant (grade I/II). Inadequacies and non-adherence towards standard operating procedures, poor documentation and lack of continuing education were the three most prominent causes. CONCLUSION: Preliminary data suggest a vulnerability of LMIC set-up to radiotherapy errors and emphasises the need for the development of longitudinal prospective processes, such as voluntary reporting and a continued education system, to ensure robust and comprehensive safe practises on par with centres in developed countries.

Dosimetric comparison of conventional radiograph- and three-dimensional computed tomography-based planning using dose volume indices for partial breast intraoperative implants.

AIMS: The dosimetric outcomes of radiograph- and computed tomography-based plans generated with various optimisation strategies were compared using dose volume indices for partial breast intraoperative implants. MATERIALS AND METHODS: Eighteen patients with early stage breast cancer underwent conventional orthogonal radiograph and computed tomography to generate dosimetric data. Catheter reconstruction and delineation of the lumpectomy cavity, the planning target volume (PTV) and the ipsilateral breast were carried out on computed tomography images. For each patient, geometrically optimised plans (P(xray) and P(CT)) were generated using the active loading length based on the PTV defined from radiographs (PTV(xray)) and computed tomography (PTV(CT)). The plan P(CT) was further optimised graphically and yielded P(graphical). Plans were compared using the coverage index (CI), the external volume index (EI), the dose homogeneity index (DHI), the overdose volume index (OI) and the conformal index (COIN). RESULTS: The mean CI of the lumpectomy cavity estimated from P(xray), P(CT) and P(graphical) was 0.80, 0.82 and 0.92, respectively. The corresponding values for PTV(CT) were 0.69, 0.71 and 0.85. P(graphical) showed an increase in CI by 23 and 19% with respect to P(xray) and P(CT) (P<0.001 in all) with a decrease in DHI from 0.81 to 0.71 (P<0.001) and increase in OI from 0.041 to 0.087 (P<0.001). The EI was highest in P(xray) (mean 44 cm(3)) as compared with 25 cm(3) in P(CT) and 30 cm(3) in P(graphical). A significant improvement in COIN was observed in P(graphical) (mean 0.68) compared with P(xray) (0.48) and P(CT) (0.58) (P<0.001). CONCLUSIONS: Objective dosimetric evaluation on three-dimensional computed tomography confirms its superiority over conventional two-dimensional radiograph-based planning in terms of a reduction in normal breast irradiated with the prescription dose and improvement in conformity. Interactive graphical optimisation based on the target volume in computed tomography further improves conformity with a reduction in dose homogeneity. The use of dose volume indices allows the comparison of different plans and can be used as a tool to correlate dosimetric with clinical outcome.

Patient specific dosimetry for intensity-modulated radiotherapy delivered with first helical tomotherapy in India--our initial experience of 50 patients.

Two-dimensional (2D) treatment verifications were performed for fifty patients planned and treated with helical tomotherapy (HT). The treatment verification consisted of an extended dose range (EDR2) film measurement as well as point dose measurements made with an A1SL ion chamber. The agreement between the calculated and the measured film dose distributions was evaluated with the gamma parameter calculated (3 mm and 3%). Good agreement was found between measured and calculated distributions with dose parameter registration using reference marks. The mean percent discrepancy for the point dose measurements was -0.4 (SD 1.4) for the high dose, low dose-gradient region. Thus the treatment verification results confirmed the safe delivery of the planned dose to the patient with helical tomotherapy.

Commissioning and comprehensive quality assurance of commercial 3D treatment planning system using IAEA Technical Report Series-430.

The purpose of this work is to report the results of commissioning and to establish a quality assurance (QA) program for commercial 3D treatment planning system (TPS) based on IAEA Technical Report Series 430. Eclipse v 7.3.10, (Varian Medical Systems, Palo Alto, CA, U.S.A.) TPS was commissioned for a Clinac 6EX (Varian Medical Systems, Palo Alto, CA, USA) linear accelerator. CT images of a phantom with various known in-homogeneities were acquired. The images were transferred to TPS and tested for various parameters related to patient data acquisition, anatomical modeling, plan evaluation and dose calculation. Dosimetric parameters including open, asymmetric and wedged shaped fields, oblique incidence, buildup region behavior and SSD dependence were evaluated. Representative clinical cases were tested for MU calculation and point doses. The maximum variation between the measured and the known CT numbers was 20 +/- 11.7 HU (1 SD). The results of all non-dosimetric tests were found within tolerance, however expansion at the sharp corners was found distorted. The accuracy of the DVH calculations depends on the grid size. TPS calculations of all the dosimetric parameters were in good agreement with the measured values, however for asymmetric open and wedged fields, few points were found out of tolerance. Smaller grid size calculation showed better agreement of dose calculation in the build-up region. Independent tests for MU calculation showed a variation within +/-2% (relative to planning system), meanwhile variation of 3.0% was observed when the central axis was blocked. The test results were in agreement with the tolerance specified by IAEA TRS 430. A subset of the commissioning tests has been identified as a baseline data for an ongoing QA program.

Commissioning and validation of commercial deformable image registration software for adaptive contouring.

PURPOSE: To report the commissioning and validation of deformable image registration(DIR) software for adaptive contouring. METHODS: DIR (SmartAdapt®v13.6) was validated using two methods namely contour propagation accuracy and landmark tracking, using physical phantoms and clinical images of various disease sites. Five in-house made phantoms with various known deformations and a set of 10 virtual phantoms were used. Displacement in lateral, anterio-posterior (AP) and superior-inferior (SI) direction were evaluated for various organs and compared with the ground truth. Four clinical sites namely, brain (n = 5), HN (n = 9), cervix (n = 18) and prostate (n = 23) were used. Organs were manually delineated by a radiation oncologist, compared with the deformable image registration (DIR) generated contours. 3D slicer v4.5.0.1 was used to analyze Dice Similarity Co-efficient (DSC), shift in centre of mass (COM) and Hausdorff distances Hf95%/avg. RESULTS: Mean (SD) DSC, Hf95% (mm), Hfavg (mm) and COM of all the phantoms 1-5 were 0.84 (0.2) mm, 5.1 (7.4) mm, 1.6 (2.2) mm, and 1.6 (0.2) mm respectively. Phantom-5 had the largest deformation as compared to phantoms 1-4, and hence had suboptimal indices. The virtual phantom resulted in consistent results for all the ROIs investigated. Contours propagated for brain patients were better with a high DSC score (0.91 (0.04)) as compared to other sites (HN: 0.84, prostate: 0.81 and cervix 0.77). A similar trend was seen in other indices too. The accuracy of propagated contours is limited for complex deformations that include large volume and shape change of bladder and rectum respectively. Visual validation of the propagated contours is recommended for clinical implementation. CONCLUSION: The DIR algorithm was commissioned and validated for adaptive contouring.

Implementation of failure mode and effective analysis for high dose rate brachytherapy at Tata Memorial Hospital, Mumbai, India.

PURPOSE: To report our experience of failure mode and effective analysis for high dose rate brachytherapy of gynaecological cancer carried out in our hospital. MATERIALS AND METHODS: Failure mode and effective analysis process described in AAPM TG 100 was followed: a multidisciplinary team consisting of two physicians, physicists, dosimetrists, a medical resident, a nurse, and a secretary was formed. A weekly meeting was held for four months. A process tree was created based on the overview of the entire process, with the main branches as follows: procedure in the operating room, patient imaging, contouring, treatment planning, machine quality assurance and treatment delivery. Each team member assigned the risk probability numbers based on the predefined scoring system. For a particular failure mode, if the risk probability number assigned by one member differed from the other, the highest risk probability number was taken into consideration. RESULTS: The process tree consisted of 185 nodes, with risk probability numbers ranging from 1-220, with 77 possible failure modes. Four nodes were found with risk probability numbers greater than 200, which were considered for immediate process improvements. Twenty-four nodes were found to be with risk probability numbers ranging from 100 to 200. All 24 processes were considered for process improvement, out of which 12 were found effective and feasible, which includes failure nodes with high severity score at least 8. The processes with high-risk probability numbers (greater than 200) were reduced after the introduction of process improvements. For the other processes, standard procedures were modified. The common causes of failure, were found to be due to lack of attention, human error and work pressure. CONCLUSIONS: Failure mode and effective analysis is a useful tool that uses a systematic approach for quality management of a specific process.

Monte Carlo Investigation of Photon Beam Characteristics and its Variation with Incident Electron Beam Parameters for Indigenous Medical Linear Accelerator.

PURPOSE: A Monte Carlo model of a 6 MV medical linear accelerator (linac) unit built indigenously was developed using the BEAMnrc user code of the EGSnrc code system. The model was benchmarked against the measurements. Monte Carlo simulations were carried out for different incident electron beam parameters in the study. MATERIALS AND METHODS: Simulation of indigenously developed linac unit has been carried out using the Monte Carlo based BEAMnrc user-code of the EGSnrc code system. Using the model, percentage depth dose (PDD), and lateral dose profiles were studied using the DOSXYZnrc user code. To identify appropriate electron parameters, three different distributions of electron beam intensity were investigated. For each case, the kinetic energy of the incident electron was varied from 6 to 6.5 MeV (0.1 MeV increment). The calculated dose data were compared against the measurements using the PTW, Germany make RFA dosimetric system (water tank MP3-M and 0.125 cm3 ion chamber). RESULTS: The best fit of incident electron beam parameter was found for the combination of beam energy of 6.2 MeV and circular Gaussian distributed source in X and Y with FWHM of 1.0 mm. PDD and beam profiles (along both X and Y directions) were calculated for the field sizes from 5 cm × 5 cm to 25 cm × 25 cm. The dose difference between the calculated and measured PDD and profile values were under 1%, except for the penumbra region where the maximum deviation was found to be around 2%. CONCLUSIONS: A Monte Carlo model of indigenous linac (6 MV) has been developed and benchmarked against the measured data.

Cosmesis, late sequelae and local control after breast-conserving therapy: influence of type of tumour bed boost and adjuvant chemotherapy.

AIMS: To study the influence of various factors affecting cosmetic outcome and late sequelae in a large cohort of women treated with breast-conserving therapy. MATERIALS AND METHODS: Between 1980 and 2000, 1022 pathological stage I/II breast cancer patients underwent breast-conserving therapy. On the basis of the type of tumour bed boost they received after whole breast radiotherapy, these women were assigned to three groups: (A) low dose rate (LDR) brachytherapy of 15-20 Gy (n=383); (B) high dose rate (HDR) brachytherapy of 10 Gy (optimised) in a single fraction (n=153); (C) electron beam 15 Gy/six fractions (n=460). Systemic adjuvant therapy was given to 757 women, of whom 570 received adjuvant chemotherapy. RESULTS: Cosmesis at the last follow-up was good or excellent in 77% of women. Post-radiation worsening of cosmesis was observed in 11.5% of women and was similar in the three boost groups. Moderate to severe late breast sequelae were observed in 22% of women in group B, which was significantly higher than the 12% in group A (P=0.002) and 9% in group C (P=0.0001). The actuarial 5-year local control rate was 91% and was 90, 92 and 93% in groups A, B and C, respectively. Tumour size (P=0.049) and adjuvant chemotherapy (P=0.04) were the significant factors affecting cosmetic outcome on univariate analysis. On multivariate analysis, adjuvant chemotherapy was the only factor leading to worsening in the cosmetic outcome, with P=0.03 (hazard ratio 1.65 [95% confidence interval 1.05-2.59]). CONCLUSION: The type of tumour bed boost did not have a significant effect on the worsening of cosmetic outcome. However, there were significantly more late breast sequelae in women treated with single fraction HDR implants. Chemotherapy had an adverse effect on the cosmetic outcome, but the late breast sequelae and local control rates were comparable.

Intensity modulated radiotherapy dosimetry with ion chambers, TLD, MOSFET and EDR2 film.

Purpose of this study was to report in a together our experience of using ion chambers, TLD, MOSFET and EDR2 film for dosimetric verification of IMRT plans delivered with dynamic multileaf collimator (DMLC). Two ion chambers (0.6 and 0.13 CC) were used. All measurements were performed with a 6MV photon beam on a Varian Clinac 6EX LINAC equipped with a Millennium MLC. All measurements were additionally carried out with (LiF:Mg,TI) TLD chips. Five MOSFET detectors were also irradiated. EDR2 films were used to measure coronal planar dose for 10 patients. Measurements were carried out simultaneously for cumulative fields at central axis and at off-axis at isocenter plane (+/- 1, and +/- 2 cm). The mean percentage variation between measured cumulative central axis dose with 0.6 cc ion chamber and calculated dose with TPS was -1.4% (SD 3.2). The mean percentage variation between measured cumulative absolute central axis dose with 0.13 cc ion chamber and calculated dose with TPS was -0.6% (SD 1.9). The mean percentage variation between measured central axis dose with TLD and calculated dose with TPS was -1.8% (SD 2.9). A variation of less than 5% was found between measured off-axis doses with TLD and calculated dose with TPS. For all the cases, MOSFET agreed within +/- 5%. A good agreement was found between measured and calculated isodoses. Both ion chambers (0.6 CC and 0.13 CC) were found in good agreement with calculated dose with TPS.

Commissioning of motorized wedge for the first equinox-80 telecobalt unit and implementation in the Eclipse 3D treatment planning system.

A new model of the telecobalt unit (TCU), Theratron Equinox-80, (MDS Nordion, Canada) equipped with a single 60 degree motorized wedge (MW), four universal wedges (UW) for 15 degrees, 30 degrees, 45 degrees and 60 degrees have been evaluated. MW was commissioned in Eclipse (Varian, Palo Alto, USA) 3D treatment planning system (TPS). The profiles and central axis depth doses (CADD) were measured with Wellhofer blue water phantom for MW and the measured data was commissioned in Eclipse. These profiles and CADD for MW were compared with UW in a homogeneous phantom generated in Eclipse for various field sizes. The dose was also calculated in the same phantom at 10 cm depth. For the particular MW angle and the respective open and MW beam weights, the dose was measured for a field size of 10 cm x 10 cm in a MEDTEC water phantom at 10 cm depth with a 0.13 cc thimble ion chamber (Scanditronix Wellhofer, Uppsala, Sweden) and a NE electrometer (Nuclear Enterprises, UK). Measured dose with ion chamber was compared with the TPS calculated dose. MW angle verification was also done on the Equinox for four angles (15 degrees, 30 degrees, 45 degrees and 60 degrees). The variation in measured and calculated dose at 10 cm depth was within 2%. The measured and the calculated wedge angles were in good agreement within 2 degrees. The motorized wedges were successfully commissioned in Eclipse for four wedge angles.

Peripheral dose from uniform dynamic multileaf collimation fields: implications for sliding window intensity-modulated radiotherapy.

The increase in the number of monitor units in sliding window intensity-modulated radiotherapy, compared with conventional techniques for the same target dose, may lead to an increase in peripheral dose (PD). PD from a linear accelerator was measured for 6 MV X-ray using 0.6 cm3 ionization chamber inserted at 5 cm depth into a 35 cm x 35 cm x 105 cm plastic water phantom. Measurements were made for field sizes of 6 cm x 6 cm, 10 cm x 10 cm and 14 cm x 14 cm, shaped in both static and dynamic multileaf collimation (DMLC) mode, employing strip fields of fixed width 0.5 cm, 1.0 cm, 1.5 cm, and 2.0 cm, respectively. The effect of collimator rotation and depth of measurement on peripheral dose was investigated for 10 cm x 10 cm field. Dynamic fields require 2 to 14 times the number of monitor units than does a static open field for the same dose at the isocentre, depending on strip field width and field size. Peripheral dose resulting from dynamic fields manifests two distinct regions showing a crest and trough within 30 cm from the field edge and a steady exponential fall beyond 30 cm. All dynamic fields were found to deliver a higher PD compared with the corresponding static open fields, being highest for smallest strip field width and largest field size; also, the percentage increase observed was highest at the largest out-of-field distance. For 6 cm x 6 cm field, dynamic fields with 0.5 cm and 2 cm strip field width deliver PDs 8 and 2 times higher than that of the static open field. The corresponding factors for 14 cm x 14 cm field were 15 and 6, respectively. The factors by which PD for DMLC fields increase, relative to jaws-shaped static fields for out-of-field distance beyond 30 cm, are almost the same as the corresponding increases in the number of monitor units. Reductions of 20% and 40% in PD were observed when the measurements were done at a depth of 10 cm and 15 cm, respectively. When the multileaf collimator executes in-plane (collimator 90 degrees) motion, peripheral dose decreases by as much as a factor of 3 compared with cross-plane data. The knowledge of PD from DMLC field is necessary to estimate the increase in whole-body dose and the likelihood of radiation induced secondary malignancy.

The Effect of the Canine ABCB1-1Δ Mutation on Sedation after Intravenous Administration of Acepromazine.

BACKGROUND: Dog breeds with the ABCB1-1Δ mutation have substantially truncated nonfunctional P-glycoprotein. Dogs homozygous for this mutation (mut/mut) are susceptible to the toxic adverse effects of ivermectin, loperamide, and vincristine. Anecdotal reports suggested ABCB1 mut/mut dogs showed increased depth and duration of acepromazine sedation. HYPOTHESIS/OBJECTIVES: That ABCB1 mut/mut dogs have increased depth and duration of sedation after acepromazine IV compared to normal dogs (nor/nor). ANIMALS: Twenty-nine rough-coated collies were divided into 3 groups of dogs based on their ABCB1 genotype: 10 mut/mut, 10 mut/nor, and 9 nor/nor. METHODS: Dogs were given 0.04 mg/kg of acepromazine IV. Level of sedation, heart rate, respiratory rate, and blood pressure were recorded for 6 hours after acepromazine administration. Area under the curves (AUCs) of the normalized sedation score results were calculated and compared. RESULTS: The median sedation scores for ABCB1 mut/mut dogs were higher than nor/nor dogs at all time points and were higher in mut/nor dogs for the first 2 hours. These differences were not found to be significant for any individual time point (P > .05). The median sedation score AUC for mut/mut dogs was significantly higher than nor/nor dogs (P = .028), but the AUC for mut/nor dogs was not (P = .45). There were no significant differences between groups for heart rate, respiratory rate, and blood pressure (P > .05). CONCLUSIONS AND CLINICAL IMPORTANCE: In ABCB1 mut/mut dogs acepromazine dose rates should be reduced and careful monitoring performed during sedation.

Protection against oxidative injury and permeability alteration in cultured alveolar epithelium by transferrin-catalase conjugate.

The successful prevention of hydrogen peroxide-induced alveolar permeability alterations and cell injury by transferrin-catalase conjugate is described in this study. Permeability alterations and cell injury were induced in cultured alveolar epithelial monolayers by hydrogen peroxide. Transepithelial transport of a permeability marker, [14C] mannitol, and cellular nuclear fluorescence of a membrane integrity indicator, propidium iodide, were used to quantitate epithelial permeability and damage respectively. Hydrogen peroxide (0.1 - 10 mM) induced a dose-dependent increase in both alveolar permeability and cellular damage; however, the oxidant effect on monolayer permeability did not require prior cell damage. Electron spin resonance measurements using the spin trap 5,5-dimethyl-l-pyrroline-N-oxide indicated the formation of hydroxyl radicals in hydrogen peroxide-treated cells. Chelation of the cellular pool of iron by deferoxamine inhibited radical formation and helped protect the cells from oxidative changes. Prior treatment of the cells with catalase (0.1 U-10 U/ml) had minimal protective effects on cell injury and permeability alterations. In contrast, transferrin-catalase conjugate, at the same concentration range, exhibited much improved protective effects on the cells in response to oxidant stress. This enhanced protection was found to correlate well with an increase in cellular uptake of the enzyme conjugate via the transferrin receptor endocytosis pathway. Effective protection by the enzyme conjugate was shown to require both the antioxidant enzyme moiety and the cognate moiety for the cell surface receptor. These findings indicate the potential therapeutic merit of transferrin-catalase conjugate for the treatment of pathological processes in the lung, whenever oxidative stress is involved.

Oligonucleotide targeting to alveolar macrophages by mannose receptor-mediated endocytosis.

Antisense oligonucleotides (ONs) have proven useful for selective inhibition of gene expression. However, their effective use is limited by inefficient cellular uptake and lack of cellular targeting. In this paper, we report a drug targeting system which utilizes mannose receptor-mediated endocytosis to enhance cellular uptake of ONs in alveolar macrophages (AMs). The system employs a molecular complex consisting of partially substituted mannosylated poly(L-lysine) (MPL), electrostatically linked to a 5' fluorescently labeled ON. Upon recognition by the macrophage mannose receptors, the MPL was internalized by the receptor-mediated pathway, co-transporting the ON. Our results indicate that the AMs treated with the MPL:ON complex exhibited a significant increase in ON uptake (up to 17-fold) over free ON-treated controls. Effective ON uptake was shown to require the recognition of the mannose moiety since unmodified polylysine was much less effective in promoting ON uptake. Specific internalization of the ON:MPL complex by the mannose receptor pathway was verified by competitive inhibition using mannosylated albumin. Under this condition, the ON complex uptake was inhibited. The requirement of mannose receptors for complex uptake was further demonstrated using a macrophage cell line, J774.1, which expresses a low level of mannose receptors. When treated with the complex, these cells showed no susceptibility to ON uptake, thus suggesting the targeting ability of the carrier system to the AMs. Following cellular internalization, the ON complex appeared largely accumulated in endocytic vesicles. Enhanced endosomal exit of the ON was achieved using a fusogenic peptide derived from the amino terminal sequence of influenza virus hemagglutinin HA2. Cytotoxicity studies showed that at the concentrations effectively enhancing ON uptake, both MPL and the fusogenic peptide caused no toxic effects to the cells, thereby suggesting their potential safety and utilization in vivo.

Probiotic and prebiotic-probiotic PEC microparticles for sustaining and enhancing intestinal probiotic growth.

The aim of the study was to develop and evaluate Polyelectrolyte complex (PEC) microparticles composing Lactobacillus Acidophilus (probiotic) and Fructo oligosaccharide-Lactobacillus Acidophilus (prebiotic-probiotic), for sustaining and enhancing intestinal growth of probiotic bacteria. Gum Karaya-Chitosan(GK-CH) was used to fabricate PEC microparticles by extrusion method. The prepared microparticles were characterized for FT-IR, DSC and particle size and evaluated for percentage yield, swelling, surface morphology, entrapment rate and further studied for influence of prebiotic over probiotic growth. The fabricated PEC microparticles composed of Probiotic and Prebiotic- Probiotic have exhibited sustainability of probiotic bacteria for 12 hrs in GIT conditions and presence of prebiotic in the preparation enhanced the probiotic cell growth. Hence, it can be concluded that PEC between GK-CH was found to be successful in sustaining cell release and presence of prebiotic was found to enhance the probiotic cell growth.

Treatment volume from total reference air kerma (TRAK) in intracavitory applications and its comparison with ICRU reference volume.

PURPOSE: A systematic dosimetry study conforming to International Commission on Radiation Units and Measurements Report Number 38, was carried out for, cancer of Cervix Stage I and II cases at Tata Memorial Hospital. METHODS AND MATERIALS: The reference Volume dimension were noted for each applicator. Also 3-D dosimetry was performed for selected cases, and actual geometric volume enclosed by various isodose surfaces were obtained. A relation was derived, which gave the volume enclosed by any isodose surface as a function of total reference air kerma of the sources in the applicator. The volume enclosed by reference isodose surface was compared with the product of its dimensions height, width, and thickness. RESULTS: The volume enclosed by any isodose surface of an intracavitary application can be easily derived from total reference air kerma of the sources within the applicator. CONCLUSION: Ratio of the volume enclosed by reference isodose surface with the product of its dimensions (HWT) could be a predictive parameter for clinical outcome, besides the reference volume specified by the report.

Primary carcinoma of the vagina: Tata Memorial Hospital experience.

PURPOSE: Carcinoma of the vagina is a rare gynecological malignancy comprising approximately 2% of all the gynecological malignancies. We have analyzed the treatment outcome of the patients treated at the Tata Memorial Hospital from January 1984 to December 1993. METHODS AND MATERIALS: In this 10-year period, 134 patients of primary vaginal cancers were registered at our hospital. Of these, 75 patients received complete treatment and are analyzed. RESULTS: Disease-free survival (DFS) for the whole group is 50%, and overall survival (OAS) is 60%. Most locoregional recurrences and distant failures are noted in the 2 years following treatment. DFS at 5 years is as follows: Stage I (5 patients), Stage IIA (37 patients), Stage IIB (15 patients), Stage III (14 patients), and Stage IV (4 patients); are 40%, 55%, 60%, 50%, and 25%, respectively. The DFS for patients with complete response (42 patients) to external radiation at 5 years is 68%, with partial response (25 patients) is 35%, and with poor or no response (6 patients) is 18% (p = 0.0000). We observed that brachytherapy was an important part of the treatment, and patients who received brachytherapy (59 patients), either with a vaginal intracavitary applicator (30 patients) or interstitial implant (29 patients) had a DFS of 53% and 56%, respectively, while 15 patients who received external radiation alone had a DFS of 30%. Patients receiving brachytherapy within 4 weeks of external radiation had a DFS of 60% as compared to 30% when the interval was more than 4 weeks. CONCLUSION: The factors indicating prognosis are: site and extent of involvement, presence of lymph nodes at presentation, technique of brachytherapy, and interval between external radiation and brachytherapy.