Standardization of Stereotactic MR-Guided Adaptive Radiation Therapy Planning for Prostate Cancer

PURPOSE/OBJECTIVE(S)

To assess the impact of a standardized planning class solution (PCS) in stereotactic MR-guided adaptive radiation therapy (SMART) for prostate cancer on efficiency and robustness for daily adaptive radiation therapy treatments.

MATERIALS/METHODS

Data collection of 20 previous SMART prostate plans: number of objective structures, number of beam segments, treatment delivery time (TDT) and the plan adaption robustness (PAR). The PAR was scored from 1 to 3 for the robustness of the plan to re-adapt and achieve similar dose metric scores to the baseline plan on all fractions. These scores were, 1: a single re-optimization required, 2: cost-function adjustments required and 3: medical physics advice required. Five medical dosimetrists provided preferences for objective structures and the optimization thresholds used. A PCS was created based on this data and implemented into SMART prostate plans between October 2022 and December 2022. A consecutive sample of 20 patients (PCSpost) were then retrospectively compared with the previous 20 patients prior to the PCS (PCSpre).

RESULTS

The PCS showed minimal difference in the TDT and segment number mean ± (standard deviation), 9.5 ± (0.7) mins and 77.8 ± (6.9) segments PCSpost respectively compared to 9.5 ± (0.8) mins and 80.8 ± (5.9) segments PCSpre. However, the PCS resulted in a considerable reduction in PAR, with 11 patients requiring only a single re-optimization for each fraction to achieve dose metric targets compared to 7 PCSpre patients. Also, the median PAR score was 1 in PCSpost compared to a score of 2 with PCSpre. The PCS had good compliance with the criteria met in 18/20 patient baseline plans. Feedback surveys showed positive results for efficiency saving from multiple disciplines; in therapeutic radiographers from reduced PAR, medical physicists increased automation in plan checking and consistent planning guidelines for medical dosimetrists.

CONCLUSION

The PCS is in clinical use, results have shown improved treatment adaption efficiency and robustness. Fewer re-optimizations per treatment were required onset to achieve similar dose metrics than before its implementation.

Assessment of prescribing pattern of drugs and completeness of prescriptions as per the World Health Organization prescribing indicators in various Indian tertiary care centers: A multicentric study by Rational Use of Medicines Centers-Indian Council of Medical Research network under National Virtual Centre Clinical Pharmacology activity

OBJECTIVE

The rational use of medicines as per the World Health Organization (WHO) should be practiced globally. However, data regarding the completeness of the prescriptions and their rational use is lacking from developing countries like India. Thus, the aim of this study was to assess the prescribing patterns of drugs and completeness of prescriptions as per WHO core drug use and complementary indicators to provide real-life examples for the Indian Council of Medical Research (ICMR) online prescribing skill course for medical graduates.

METHODS

Prescriptions of the patients, fulfilling inclusion criteria, attending Outpatient Departments of various specialties of tertiary care hospitals, were collected by thirteen ICMR Rational use of medicines centers located in tertiary care hospitals, throughout India. Prescriptions were evaluated for rational use of medicines according to the WHO guidelines and for appropriateness as per standard treatment guidelines using a common protocol approved by local Ethics committees.

RESULTS

Among 4838 prescriptions, an average of about three drugs (3.34) was prescribed to the patients per prescription. Polypharmacy was noted in 83.05% of prescriptions. Generic drugs were prescribed in 47.58% of the prescriptions. Further, antimicrobials were prescribed in 17.63% of the prescriptions and only 4.98% of prescriptions were with injectables. During the prescription evaluation, 38.65% of the prescriptions were incomplete due to multiple omissions such as dose, duration, and formulation.

CONCLUSION

Most of the parameters in the present study were out of the range of WHO-recommended prescribing indicators. Therefore, effective intervention program, like training, for the promotion of rational drug use practice was recommended to improve the prescribing pattern of drugs and the quality of prescriptions all over the country.

Development of dipstick enzyme linked immunosorbent assay for on-site sero-diagnosis of Japanese encephalitis in swine

Japanese encephalitis (JE) is an important viral zoonotic disease in Asia, especially in rural and suburban areas where rice cultivation and pig farming coexist. Pigs serve as a suitable sentinel model, the surveillance of which could predict a potential JE outbreak in human population in the immediate vicinity. However, existing diagnostics like ELISA and VNT require sophisticated laboratory facilities which are more often not available in field conditions. In the present study, we aimed at developing recombinant non-structural (NS1) protein-based dipstick IgG ELISA as an on-site assay for sero-diagnosis of JE in swine. The assay was standardized by optimizing various parameters and the following conditions were found to be ideal including 1 μg of rNS1 protein in carbonate buffer per strip of nitrocellulose membrane comb; bovine serum albumin as blocking agent at 4 °C overnight; serum dilution of 1:10 and conjugate dilution of 1:5000 in skimmed milk powder. Relative diagnostic sensitivity and specificity of dipstick IgG ELISA was 100% and 92.9%, respectively. The dipstick assay was validated in three laboratories as per OIE guidelines. The storage life of dipstick was up to 7 months at 4 °C. The assay is easy to perform and the results can be interpreted with visual observation that precludes the need for absorbance reading equipment. The standardized dipstick assay was found promising for screening swine serum samples in field conditions. Timely detection of JE virus in swine will aid in predicting the outbreak in humans and thus in taking suitable preventive and control measures.

Seasonal occurrence of Japanese encephalitis vectors in Bareilly district, Uttar Pradesh, India

BACKGROUND & OBJECTIVES

Japanese encephalitis (JE) is one of the most common causes of acute encephalitis syndrome in many states of India. Uttar Pradesh state is well known for JE endemicity, contributing 75% of total cases during recent past. Several sporadic cases have been reported from Bareilly region of the state. The disease spread by bite of Culex mosquito. Survey of literature revealed no data on mosquito fauna with reference to JE in this region. Therefore, this study was planned to survey seasonal mosquito population and occurrence of JE vectors in Bareilly region.

METHODS

Mosquitoes were sampled on monthly basis from organized pig farm from February 2016 to January 2017 and identified using mosquito identification keys. The meteorological parameters of the area were obtained monthly and standard statistical methods were used to assess the relationship between different weather variables and mosquito population.

RESULTS

A total of 4337 mosquitoes belonging to five genera were collected. Mosquitoes of genus Culex were predominant and contributed 84.41% to the total catch. The most dominant species was Cx. tritaeniorhynchus (30.81%), followed by Cx. quinquefasciatus (28.50%), Cx. gelidus (17.24%), Cx. pseudovishnui (11.85%), Cx. vishnui (8.11%), Cx. fuscocephala (2.70%), Cx. infula (0.76%) and Cx. bitaeniorhynchus (0.03%). Pronounced seasonal variation was observed with majority of mosquitoes showing high density in monsoon and post-monsoon period.

INTERPRETATION & CONCLUSION

The present study provides knowledge on distribution of JE vector in Bareilly which indicates that the area is at risk of JE outbreak. Abundance of Culex vector clearly demarcates possible threat of JE incidence in the study area. A long-term entomological study is needed to further evaluate the significant role of different weather variables in shaping mosquito densities.

Developing and assessing the utility of a You-Tube based clinical genetics video channel for families affected by inherited tumours

We have designed and implemented the first worldwide You Tube channel with 22 videos covering common questions asked in familial cancer susceptibility clinics. We discuss the use of the videos including demographics of registered You Tube users, and what lessons have been learnt about how the general public uses medical information online. The most popular video on inheritance patterns has been watched on average 84 times per month. The mostly highly viewed videos include inheritance patterns, breast cancer screening and hereditary non-polyposis colorectal cancer. Registered viewers were more commonly male and the average age of the registered user was 45-54 years; similar to that seen in Genetics Clinics suggesting that age may not be a major barrier to access to this type of information for patients. The videos have been viewed in more than 140 countries confirming that there is clearly an audience for this type of information. Patient feedback questionnaires indicate that these videos provide a useful aide memoir for the clinic appointment, and most people would recommend them to others. In summary, You Tube videos are easy and cost effective to make. They have the ability to disseminate genetics education to a worldwide audience and may be a useful adjunct to clinical appointments.

Targeting the hedgehog transcription factors GLI1 and GLI2 restores sensitivity to vemurafenib-resistant human melanoma cells

BRAF inhibitor (BRAFi) therapy for melanoma patients harboring the V600E mutation is initially highly effective, but almost all patients relapse within a few months. Understanding the molecular mechanisms underpinning BRAFi-based therapy is therefore an important issue. Here we identified a previously unsuspected mechanism of BRAFi resistance driven by elevated Hedgehog (Hh) pathway activation that is observed in a cohort of melanoma patients after vemurafenib treatment. Specifically, we demonstrate that melanoma cell lines, with acquired in vitro-induced vemurafenib resistance, show increased levels of glioma-associated oncogene homolog 1 and 2 (GLI1/GLI2) compared with naïve cells. We also observed these findings in clinical melanoma specimens. Moreover, the increased expression of the transcription factors GLI1/GLI2 was independent of canonical Hh signaling and was instead correlated with the noncanonical Hh pathway, involving TGFβ/SMAD (transforming growth factor-β/Sma- and Mad-related family) signaling. Knockdown of GLI1 and GLI2 restored sensitivity to vemurafenib-resistant cells, an effect associated with both growth arrest and senescence. Treatment of vemurafenib-resistant cells with the GLI1/GLI2 inhibitor Gant61 led to decreased invasion of the melanoma cells in a three-dimensional skin reconstruct model and was associated with a decrease in metalloproteinase (MMP2/MMP9) expression and microphthalmia transcription factor upregulation. Gant61 monotherapy did not alter the drug sensitivity of naïve cells, but could reverse the resistance of melanoma cells chronically treated with vemurafenib. We further noted that alternating dosing schedules of Gant61 and vemurafenib prevented the onset of BRAFi resistance, suggesting that this could be a potential therapeutic strategy for the prevention of therapeutic escape. Our results suggest that targeting the Hh pathway in BRAFi-resistant melanoma may represent a viable therapeutic strategy to restore vemurafenib sensitivity, reducing or even inhibiting the acquired chemoresistance in melanoma patients.

Ethanol vapour-fixation of rat lung for immunocytochemistry investigations

Ethanol-vapour fixation of rat lung has been successfully employed in the immunocytochemical detection of the gastrin mucin antigen termed mucin 5AC without the need of additional antigen retrieval steps. This procedure gives good morphological preservation and provides all the benefits associated with the microscopic examination of inflated lung tissue. This simple fixation technique provides another option for use in immunocytochemical investigations of rodent lung and could be adapted for other species.

Transcriptional regulation of the glucokinase gene by biotin in starved rats

The purpose of this work was to investigate whether biotin, a water-soluble vitamin, regulates the glucokinase gene. Biotin was administered intraperitoneally to starved rats, and the time course of glucokinase induction was followed over a time period of 12 h. The glucokinase mRNA was increased 19.6-fold during the first 1 h after biotin administration, afterwards rapidly decayed, and was hardly detectable by 4 h. The amount of glucokinase activity as determined by conventional enzyme activity assay increased in a time-dependent fashion, reaching 4-fold by 2 h of biotin administration. The transcriptional activity of the gene as measured by a nuclear run-on assay was increased about 6.7-fold within 45 min of biotin administration. These findings indicate that biotin can regulate the glucokinase gene at the transcriptional stage in the starved rat.

Relationships between sour and salt taste perception and selected subject attributes

The relationships between perceived sour and salt taste intensity and selected subject attributes--taste/smell deficits, salt use, avoidance of salt/sour tasting foods, smoking, alcohol use, dentures, education, and prescription drug use--were investigated in 180 subjects (30 men and 30 women/age group: 20 to 29 years [young], 70 to 79 years [old], 80 to 99 years [very old]. Multiple regression analyses showed that the taste intensity estimates were significantly related to age, sex, stimulus concentration, self-reported taste/smell deficits, avoidance of salt/sour tasting foods, salt use, alcohol, smoking, education, and use of certain drugs (drugs for the treatment of arthritis, drugs acting on the gastrointestinal tract and heart system, and diuretics/drugs for the treatment of hypertension). The very old showed deficits in perception of the low suprathreshold tastant levels, with near normal perception of the high levels, whereas the old exhibited deficits at all levels. Wearing dentures was the only single variable not selected in any of the final regression models, due to the high prevalence and homogeneity in use of dentures in the elderly groups. Further work using a stratified sample and a large number of subjects is warranted to elucidate the influence of subject attributes on taste perception.

Taste discrimination of traditional and 'health' modified recipes

Beef stew and sponge cake were prepared utilising traditional recipes and recipes modified in accordance with NACNE, National Advisory Committee on Nutrition Education guidelines (1983). Triangle tests were performed to determine whether subjects could discriminate between samples prepared using the traditional recipes. Thirty subjects (15 men and 15 women) participated. No significant differences could be established between the traditional and modified stew or sponge cake in terms of eating quality. Modification of traditional recipes by reducing sugar, fat and salt and increasing the fibre content without affecting the overall sensory quality that the consumer expects is an ideal way of achieving recommended dietary goals.

Role of human serum biotinidase as biotin-binding protein

Biotinidase shows two binding sites for biotin, with Kd = 59 and 3 nM respectively, and requires tryptophan and cysteine residues of the biotinidase protein for biotin-binding activity. Analysis of human serum by various column-chromatographic techniques indicates that biotinidase is the only protein which exchanges with labelled (+)-biotin. It was shown previously that epileptic patients receiving a high average dose of anticonvulsants (containing a carbamide group) have lower biotin concentrations than those receiving a low dose. We have shown in human serum and with purified biotinidase that these anticonvulsant drugs compete with biotin for binding to the protein moiety.

Suprathreshold sour taste intensity and pleasantness perception with age

Magnitude estimates for perceived intensity and pleasantness of suprathreshold concentrations of citric acid in solution and drink were examined in 180 healthy, free-living subjects divided into three groups: young (20-29 years), old (70-79 years) and very old (80-99 years). Psychophysical functions showed significant age effects. For both aqueous and food systems, the old gave higher intensity estimates to high acid concentrations and lower intensity estimates to low acid levels compared to the young and very old whose estimates were comparable. Sex had a significant effect on the intensity estimates with the women giving low acid levels lower estimates and high acid levels higher estimates than the men. All subjects gave low acid levels in solution lower intensity estimates than comparable drinks while at high concentrations, higher intensity estimates were given to solutions than drinks. Trend analysis of pleasantness estimates indicated significant age group differences. For both systems, the breakpoint, the acid level assigned the highest pleasantness estimate was lower for the young than for the elderly.

Age-related olfactory and taste changes and interrelationships between taste and nutrition

This article critically reviews the literature on age-related olfactory and taste changes and the interrelationships between nutrition and taste. Age-related taste alterations are controversial, but there is consensus on an olfactory decline with age. Much of the age-related chemoreceptive research has used inappropriate methodology, thus leaving many findings inconclusive. Changes in the taste system with age may be related to nutrient intake, which in turn can be influenced by taste. Literature on such interrelationships is limited. Vitamins A, thiamin, B-6, B-12, folacin, zinc, and copper are thought to influence taste function. Moreover, those nutrients are of concern in the aged. The use of appropriate methodology is critical not only for the sensory but also for the nutritional aspects, particularly for qualitative and quantitative assessments of nutrient intakes. This review considers the experimental deficiencies (small sample size, inappropriate age range, inadequate psychophysical and stimuli presentation procedures, and poor dietary intake assessment) of studies reported in the literature and suggests major needs for research.

Intestinal absorption of biotin and biocytin in the rat

The uptake of biotin and biocytin was investigated in rat intestine using the everted sac technique. It has been shown that at biotin and biocytin concentrations less than 40 and 50 nM respectively, absorption proceeds by a saturable process, whereas at higher concentrations uptake by passive diffusion predominates. Fractionation of solubilized brush border preparations indicates that biotinidase is the only protein which binds biotin in this preparation.

Purification and characterization of human serum biotinidase

Biotinidase has been purified from human serum to a specific activity of 1900 units/mg protein by a five-step procedure. After ammonium sulfate precipitation (33-55% cut) it was purified by DEAE-Sephacel, hydroxylapatite, octyl-Sepharose CL-4B, and Sephadex G-100 chromatography. The purified enzyme showed a single silver staining band with polyacrylamide gel electrophoresis under denaturing and non-denaturing conditions. Biotinidase is a glycoprotein. The sialic acid residues in the molecule are not required for enzyme activity. The Mr of human serum biotinidase estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Ferguson plot) and by sedimentation analysis was 68,000. Human serum biotinidase showed maximum activity in the pH range 6.0 to 7.5 with N-(d-biotinyl) p-aminobenzoate as substrate. However, with biocytin as substrate, the maximal activity of the enzyme was in the pH range 4.5 to 6.0. Using structural analogs of the substrate we have shown that biotinidase is not a general proteolytic enzyme and has specific structural requirements in the substrate for hydrolysis.

Determination of urinary amino acids by means of glass capillary gas-liquid chromatography with alkali-flame ionisation detection and flame ionisation detection

The determination of amino acids as their N(O)-heptafluorobutyryl-isobutyl ester derivatives by glass capillary gas--liquid chromatography has been studied. Separations of amino acids obtained from insulin hydrolysate and human urine analysed with a flame ionisation detector, an alkali-flame ionisation detector and an electron-capture detector are shown. The quantitative results of urinary amino acids of one deep-sea diver are presented.

Determination of homovanillic, isohomovanillic and vanillylmandelic acids in human urine by means of glass capillary gas-liquid chromatography with temperature-programmed electron-capture detection

The determination of urinary homovanillic, isohomovanillic and vanillylmandelic acids as their trifluoroacetylhexafluoroisopropyl ester derivatives by glass capillary gas-liquid chromatography has been studied. It was shown that even with high column efficiencies a single peak-single compound relationship could not be assumed and for reliable quantitation it was necessary to check determinations with a second gas-liquid chromatography column.