Significance of Radiomics in Predicting Local Control for Patients with Malignant Liver Tumors Treated Using Stereotactic Body Radiotherapy

PURPOSE/OBJECTIVE(S)

We routinely deliver Stereotactic Body Radiotherapy (SBRT) in malignant liver tumors using planning computed tomography (CT) and Magnetic Resonance Images (MRI) to aid target definition. In this study, we extracted radiomic features from the MR images to predict local control (LC) post-SBRT.

MATERIALS/METHODS

We retrospectively analyzed patients with either hepatocellular cancers (HCCs) or liver metastases (Mets) treated with SBRT between Aug 2014 and Aug 2020. All patients had CT simulation followed by 1.5 Tesla planning MRI in treatment position. Contrast enhanced T1 VIBE and T2 Haste MR sequences were registered with planning CT for target definition. Radiomic features were extracted from Gross Tumor Volumes (GTV) masked out of 60 seconds post contrast T1 VIBE MR images using the Radiomics calculator tool RaCaT. The output included 480 (408 textural, 50 intensity and 22 morphological) features for each target. Principal Component Analysis of the outputs obtained from all the targets yielded 20 radiomic feature clusters after computational prioritization. These clusters were correlated to LC outcomes at various time points post-SBRT. LC was defined as non-progressive disease. Accuracy of predictions was measured by area under (AUC) receiver operating characteristic curve. Cox regression analysis was done to find univariate and multivariate clinical [HCCs vs. Mets, single vs. multiple lesions, previous local therapy (yes vs. no), GTV volume (≤40 vs. >40 cc)], radiomic and dosimetric predictors (continuous) of LC.

RESULTS

In total, 97 patients received SBRT to 122 lesions. The median dose prescribed was 45 Gy (range, 30-50 Gy). Median age was 69 years (interquartile range, IQR 61-73 yrs.). 59 patients had HCCs and 38 had Mets. 24 lesions had prior ablative therapy. 75 patients had one target, and 22 had multiple targets. Median GTV was 43.5 cc (IQR 23.4-78.6 cc). Median follow up was 16.6 months (IQR 9.7-27.2 mths). Median LC was 13.6 months (IQR 8.0-23.5 mths). On univariate analysis, histology (HCCs vs. Mets; Hazard ratio (HR) 2.9, 95% CI 1.4-6.4; p < 0.006), radiomic clusters (p < 0.006) and the max., mean, and min. doses to GTV and Planning Target Volumes correlated with improved LC (all p-values < 0.05). On multivariate analysis, histology (HCCs vs. Mets; HR 4.4, 95% CI 1.6-12.3; p = 0.004), radiomic clusters (p = 0.034) and prescription dose (p = 0.048) were significant covariates. Specifically, the 20 radiomic clusters were predictive of LC, and the accuracy of predictions showed promise with AUC values of 0.74, 0.80, and 0.81 at 12, 24, and 36 months post-SBRT, respectively. AUC values for LC in HCCs vs. Mets at 12, 24, and 36 months were 0.83, 0.77, and 0.70, and 0.66, 0.77, and 0.88, respectively.

CONCLUSION

MR-based radiomics predict LC post-SBRT in patients with malignant liver tumors. Further research focused on independent validation of the model is required to explore its clinical use.

Sol-Gel-Derived Ordered Mesoporous High Entropy Spinel Ferrites and Assessment of Their Photoelectrochemical and Electrocatalytic Water Splitting Performance

The novel material class of high entropy oxides with their unique and unexpected physicochemical properties is a candidate for energy applications. Herein, it is reported for the first time about the physico- and (photo-) electrochemical properties of ordered mesoporous (CoNiCuZnMg)Fe₂ O₄ thin films synthesized by a soft-templating and dip-coating approach. The A-site high entropy ferrites (HEF) are composed of periodically ordered mesopores building a highly accessible inorganic nanoarchitecture with large specific surface areas. The mesoporous spinel HEF thin films are found to be phase-pure and crack-free on the meso- and macroscale. The formation of the spinel structure hosting six distinct cations is verified by X-ray-based characterization techniques. Photoelectron spectroscopy gives insight into the chemical state of the implemented transition metals supporting the structural characterization data. Applied as photoanode for photoelectrochemical water splitting, the HEFs are photostable over several hours but show only low photoconductivity owing to fast surface recombination, as evidenced by intensity-modulated photocurrent spectroscopy. When applied as oxygen evolution reaction electrocatalyst, the HEF thin films possess overpotentials of 420 mV at 10 mA cm^-2 in 1 m KOH. The results imply that the increase of the compositional disorder enhances the electronic transport properties, which are beneficial for both energy applications.

Mesoporous CuFe2 O4 Photoanodes for Solar Water Oxidation: Impact of Surface Morphology on the Photoelectrochemical Properties

Metal oxide-based photoelectrodes for solar water splitting often utilize nanostructures to increase the solid-liquid interface area. This reduces charge transport distances and increases the photocurrent for materials with short minority charge carrier diffusion lengths. While the merits of nanostructuring are well established, the effect of surface order on the photocurrent and carrier recombination has not yet received much attention in the literature. To evaluate the impact of pore ordering on the photoelectrochemical properties, mesoporous CuFe₂ O₄ (CFO) thin film photoanodes were prepared by dip-coating and soft-templating. Here, the pore order and geometry can be controlled by addition of copolymer surfactants poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (Pluronic® F-127), polyisobutylene-block-poly(ethylene oxide) (PIB-PEO) and poly(ethylene-co-butylene)-block-poly(ethylene oxide) (Kraton liquid™-PEO, KLE). The non-ordered CFO showed the highest photocurrent density of 0.2 mA/cm² at 1.3 V vs. RHE for sulfite oxidation, but the least photocurrent density for water oxidation. Conversely, the ordered CFO presented the best photoelectrochemical water oxidation performance. These differences can be understood on the basis of the high surface area, which promotes hole transfer to sulfite (a fast hole acceptor), but retards oxidation of water (a slow hole acceptor) due to electron-hole recombination at the defective surface. This interpretation is confirmed by intensity-modulated photocurrent (IMPS) and vibrating Kelvin probe surface photovoltage spectroscopy (VKP-SPS). The lowest surface recombination rate was observed for the ordered KLE-based mesoporous CFO, which retains spherical pore shapes at the surface resulting in fewer surface defects. Overall, this work shows that the photoelectrochemical energy conversion efficiency of copper ferrite thin films is not just controlled by the surface area, but also by surface order.

An antimicrobial activity of oil extracted from Saara hardwickii

Present research work represents antiviral and antibacterial value of body fat of Saara hardwickii commonly called as spiny tailed lizard. Oil was extracted from body fats located in the ventral region of this animal using hydrocarbons e.g., n-hexane, methanol, butanol and ethyl acetate as a solvent. The antibacterial activity of lizard oil was tested against standard as well as multi-resistant lines ofEscherichia coli, Styphalococcus aureus, Pseudomonas aeruginosa and Proteus vulgaris alone and with antibiotic ampicillin. For antibacterial potential, Ethyl acetate and Butanol solvent extract showed best zone of inhibition (7mm) with P. aeruginosa and S. aureus respectively. For antiviral potential, Butanol and Methanol extract showed best HA (Hemagglutination) titer of 04 with NDV and IBV viral strain respectively. It is concluded that lizard oil has antimicrobial potential against different pathogens strains (virus, bacteria).

Revision of some mensural measurements, food preference, and haematological parameters in breeding pairs of blue rock pigeon, Columba livia sampled from punjab Pakistan

The present study describes the haematological profile, feeding preference, and comparison of morphometric characters of blue rock pigeon (Columba livia) breeding pairs. For this purpose, 25 pairs (25 samples per sex) were sampled through Mist nets from district Okara and Bahawalnagar, Punjab, Pakistan. Birds were then anaesthetized with a combination of ketamine HCL (10 mg/kg) and diazepam (0.2 mg/kg) and subjected to morphometric measurements. 5µL blood also was taken from the jugular vein of each anaesthetized bird for haematological analysis. Few pairs were also dissected to remove gastrointestinal tracts (GITs) for food preferences. Results revealed that there are no significant differences in the haematological parameters and feeding preference of breeding pairs of Columba livia. The gut analysis further revealed, the major portion of gut contents consisted of pea and corn in most of the pairs. Regarding the mensural measurements, significant differences were recorded in the body weight, length of the longest primary feather, and chest circumference, whereas the rest of the studied parameters remain nonsignificant between sexes. So, it is concluded that apart from 3 morphometric parameters (body weight, length of longest primary feather and chest circumference), both sexes are alike in term of morphometry, haematology and food preference.

AB0626 IMATINIB FOR THE TREATMENT OF SYSTEMIC SCLEROSIS: RATIONALE, CLINICAL EVIDENCE AND FUTURE DEVELOPMENT

Background:

Systemic sclerosis (SSc) is a chronic disorder of connective tissue affecting the skin and internal organs. The molecular mechanisms behind SSc are not entirely understood, but recent advances highlight key signalling pathways1(see Figure 1). Fibrosis disrupts tissue architecture resulting in organ dysfunction. This causes significant morbidity and mortality1, therefore there is a clear need for identifying efficacious antifibrotic treatment.

Imatinib is a tyrosine kinase inhibitor with established use in some malignancies, and existing evidence that it can treat SSc2.

Objectives:

The aim of this literature review is to summarise the current evidence and future developments of imatinib as antifibrotic treatment in SSc.

Methods:

PubMed headings “systemic sclerosis”, “scleroderma”, “imatinib” and synonyms were used. See Figure 2.

Results:

Lead author and yearStudy designPopulationIntervention (imatinib dose given daily)ResultsHinchcliff ME. 2016Case study1 female (F) with an 8-month history of diffuse cutaneous systemic sclerosis (dcSSc)400mgSevere adverse events (AEs)Pope J. 2014Early phase proof of concept trial10 with dcSSc.9 given 400mg, 1 placeboPoor drug tolerabilityPrey S. 2012Double blind RCT28 with SSc15 given 400mg, 13 placeboNo improvementKhanna D. 2011Phase I/IIa pilot trial20 with SScUp to 600mgAEs presentPope J. 2011Double blind RCT10 with SSc.9 given 400mg, 1 placeboNo improvement, AEs presentGordon J. 2014Open label, single arm, extension phase clinical trial17 with average disease duration of 3.5 years100-400mg↓ modified Rodnan skin score (mRSS)Fraticelli P. 2014Phase II pilot trial30 with SSc200mg↑ lung functionGuo L. 2012Case series6 F, Chinese pts with SSc200mg↓ mRSS and ↑ lung functionDivekar AA. 2011Single centre, open-label study15 with SSc100mg up to 600mg/day↑ lung functionSpiera RF. 20111-year, phase IIa, single-arm, open-label clinical trial30 with dcSSc400mg↓ mRSS and ↑ lung functionFreyhaus H. 2009Case report58yo F400mg↑ lung functionChung L. 2009Case report2 with early dcSSc200mg↓ mRSS and ↑ lung functionVan Daele PL. 2008Case report69yo F400mg↓ mRSS and ↑ lung functionP. P. Sfikakis. 2008Case report24yo F400mg↓ mRSS and ↑ lung function

9 studies showed imatinib had positive efficacy in the treatment of SSc. 5 showed no improvement or adverse effects.

Conclusion:

Overall, current evidence suggests that imatinib can be a useful drug to improve manifestations of SSc, for some. Despite inconclusive evidence, a dose-dependent relationship seems to exist for imatinib toxicities, with more research needed to ascertain a safe dose.

Gene expression profiles may distinguish patients that can benefit from imatinib3. Also, Notch signalling could be exploited to increase imatinib uptake into fibroblasts, thereby increasing efficacy4.

References:

[1]Pattanaik D et al. Pathogenesis of Systemic Sclerosis. Frontiers in Immunology. 2015;6: 272

[2]Distler JHW et al. Tyrosine kinase inhibitors for the treatment of fibrotic diseases such as systemic sclerosis: towards molecular targeted therapies. Annals of the Rheumatic Diseases. 2010;69: 48-51

[3]Chung L et al. Molecular framework for response to imatinib mesylate in systemic sclerosis. Arthritis and Rheumatology. 2009 Feb;60(2):584-91

[4]Harrach S et al. Notch Signaling Activity Determines Uptake and Biological Effect of Imatinib in Systemic Sclerosis Dermal Fibroblasts. Journal of Investigative Dermatology. 2019; 139(2):439-4475

Acknowledgments:

Skin Research Institute of Singapore

Disclosure of Interests:

None declared

A study of nonlinear age-structured population models

This paper presents a novel analysis for the solution of nonlinear age-structured problem which is of extreme importance in biological sciences. The presented model is very useful but quite complicated. Modified variational iteration method (MVIM) coupled with auxiliary parameter is used to cope with the complexity of the model which subsequently shows better results as compared to some existing results available in literature. Furthermore, an appropriate way is used for the identification of auxiliary parameter by means of residual function. Numerical examples are presented for the analysis of the proposed algorithm. Graphical results along with the discussions re-confirm the efficiency of proposed algorithm. The work proposes a new algorithm where He’s polynomials and an auxiliary parameter are merged with correction functional. The suggested scheme is implemented on nonlinear age-structured population models. Graphs are plotted for the residual function that reflects the accuracy and convergence of the presented algorithm.

Fitness cost and realized heritability of resistance to spinosad in Chrysoperla carnea (Neuroptera: Chrysopidae)

The common green lacewing Chrysoperla carnea is a key biological control agent employed in integrated pest management (IPM) programs for managing various insect pests. Spinosad is used for the management of pests in ornamental plants, fruit trees, vegetable and field crops all over the world, including Pakistan. A field-collected population of C. carnea was selected with spinosad and fitness costs and realized heritability were investigated. After selection for five generations, C. carnea developed 12.65- and 73.37-fold resistance to spinosad compared to the field and UNSEL populations. The resistant population had a relative fitness of 1.47, with substantially higher emergence rate of healthy adults, fecundity and hatchability and shorter larval duration, pupal duration, and development time as compared to a susceptible laboratory population. Mean relative growth rate of larvae, intrinsic rate of natural population increase and biotic potential was higher for the spinosad-selected population compared to the susceptible laboratory population. Chrysoperla species are known to show resistance to insecticides which makes the predator compatible with most IPM systems. The realized heritability (h 2) value of spinosad resistance was 0.37 in spinosad-selected population of C. carnea.

Naringenin inhibits the growth of Dictyostelium and MDCK-derived cysts in a TRPP2 (polycystin-2)-dependent manner

BACKGROUND AND PURPOSE

Identifying and characterizing potential new therapeutic agents to target cell proliferation may provide improved treatments for neoplastic disorders such as cancer and polycystic diseases.

EXPERIMENTAL APPROACH

We used the simple, tractable biomedical model Dictyostelium to investigate the molecular mechanism of naringenin, a dietary flavonoid with antiproliferative and chemopreventive actions in vitro and in animal models of carcinogenesis. We then translated these results to a mammalian kidney model, Madin-Darby canine kidney (MDCK) tubule cells, grown in culture and as cysts in a collagen matrix.

KEY RESULTS

Naringenin inhibited Dictyostelium growth, but not development. Screening of a library of random gene knockout mutants identified a mutant lacking TRPP2 (polycystin-2) that was resistant to the effect of naringenin on growth and random cell movement. TRPP2 is a divalent transient receptor potential cation channel, where mutations in the protein give rise to type 2 autosomal dominant polycystic kidney disease (ADPKD). Naringenin inhibited MDCK cell growth and inhibited cyst growth. Knockdown of TRPP2 levels by siRNA in this model conferred partial resistance to naringenin such that cysts treated with 3 and 10 μM naringenin were larger following TRPP2 knockdown compared with controls. Naringenin did not affect chloride secretion.

CONCLUSIONS AND IMPLICATIONS

The action of naringenin on cell growth in the phylogenetically diverse systems of Dictyostelium and mammalian kidney cells, suggests a conserved effect mediated by TRPP2 (polycystin-2). Further studies will investigate naringenin as a potential new therapeutic agent in ADPKD.

The Study of Anticancer and Antifungal Activities of Pistacia integerrima Extract in vitro

Pistacia integerrima Stew. ex Brand (Anacardiaceae) is an ethanobotanically important plant species traditionally used in the treatment of chronic wounds, jaundice, dysentery, etc. The crude extract from Pistacia integerrima and its fractions were tested for cytotoxic activity against Michigan Cancer Foundation-7 human breast cancer cell line. We have also investigated that crude stem extract of this plant also exhibits the antitumour as well as antifungal potential activities. Moreover, we have also studied that the crude extract inhibited Michigan Cancer Foundation-7 cell viability in a dose-dependent manner; the poor toxicity (1.6%) at 10 μg/ml to moderate toxicity (55.4%) at 100 μg/ml. The IC₅₀ values calculated were 90.9 μg/ml. The ethyl acetate and chloroform fractions at a concentration of 200 μg/ml showed ~100 and 97.4% inhibition against Michigan Cancer Foundation-7 cell line, respectively. The crude methanol extract also showed good antitumour (IC₅₀ 125 ppm) activity, but weak antifungal activity. These findings reveal that the ethyl acetate and chloroform fractions of Pistacia integerrima are potent cytotoxic fractions, and could be an alternate candidate for the development of novel biologically active compounds.

Estimation of growth curve parameters in Beetal goats

Abstract. Growth data from birth to one year of age on 120 Beetal goats, 30 animals on each farm, including Livestock Experiment Station (LES) Rakh Kheirewala, LES Rakh Ghulaman, LES Alladad and LPRI Bahadurnagar, Okara, Pakistan, were recorded and analysed for estimating growth curve parameters: predicted live weight, »a«, turning point of growth, »b« and rate of growth »k« by using Brody and Gompertz mathematical functions employing non-linear regression models. Estimates of the growth curve parameters »a«, »b« and »k« were 29.1, 0.916 and 0.108 for Brody and 23.4, 1.984 and 0.258 for Gompertz functions, respectively. The corresponding values of determination coefficient and mean absolute deviation for these models were 99.8 and 99.8 percent and 0.0061 and 0.0050, respectively. Flock significantly affected parameter »b« of Brody and Gompertz models. Sex did not affect any of the parameters in both models. Type of birth was a significant source of variation for parameter »b« in the Brody model. The determination coefficient showed that both the models efficiently explained the growth of Beetal kids.

Anger arousal and well being as markers of social functioning and quality of life in the aftermath of exposure to life threatening trauma

Introduction

Severe stress or exposure to life threatening trauma is known to affect social functioning and quality of life.

Objectives

To study well-being and anger arousal as markers of social functioning and quality of life in a group of University students exposed to a suicide bomb attack on a University in Pakistan.

Aims

To examine indicators of social functioning in order to higlight them as targets for therapeutic interventions.

Methods

Subjects were assessed after one year of exposure to a life threatening incident on University campus. Subjects completed an assessment schedule incorporating World Health Organization's Well-Being Index and Novarco Anger Inventory (25 items).

Results

54 students completed the assessment. The mean age of the group was 24 years. All subjects had completed 14–16 years of education and were in full time education at the time of assessment. The Well Being Index Score range was 1–24 with 26 sujects scoring 13 or lower scores indicating poor quality of life. 29 subjects scored higer levels of anger arousal on 10 or more items of Novarco Anger Inventory indicating difficulties in social functioning. The overall group showed a statistically significant negative correlation between the Well-Being Index Scores and the number of Novarco Anger Inventory items scored in the two highest categories of anger arousal.

Conclusions

The results of the study highlight anger arousal and well-being as important markers of functioning in the aftermath of a stressful life event. The study confirms their usefulness as legitimate therapeutic targets for pharmacotherapy, psychotherapeutic, and social interventions.

Estimation of mean annual effective dose through radon concentration in the water and indoor air of Islamabad and Murree

Different samples of water, indoor air and soil gas have been collected from Islamabad (33 degrees 38'N, 73 degrees 09'E, altitude of 1760 ft.), the capital of Pakistan and Murree (33 degrees 53'N, 73 degrees 23'E, altitude of 7323 ft.), lying on a geological fault line and are analysed for the estimation of mean effective dose through radon concentrations by using RAD-7, a solid state alpha-detector. The variation of radon concentration in water, indoor air and soil gas in Islamabad region ranges from 25.90-158.40 kBq m(-3), 43.26-97.04 Bq m(-3) and 17.34-72.52 kBq m(-3), having mean values 88.63 kBq m(-3), 70.67 Bq m(-3) and 45.08 kBq m(-3)(,) respectively. It ranges from 1.64-10.20 kBq m(-3), 18.48-42.08 Bq m(-3) and 0.61-3.89 kBq m(-3) with mean values 4.38 kBq m(-3), 28.63 Bq m(-3) and 1.70 kBq m(-3)(,) respectively in Murree and its surroundings. The total mean annual effective doses from water and indoor air of Islamabad and Murree regions are 2.023 and 0.733 mSv a(-1), respectively. These doses are within the recommended limits of the world organisations.

Calmodulin antagonist W7 increases inositol phosphates in insulin secreting RINm5F cells

W7, a calmodulin antagonist, has been reported to increase cytosolic free calcium concentration [Ca2+]i in non stimulated rat insulinoma cells (RINm5F). And this effect was not due to enhanced calcium uptake. In the present study the effect of calmodulin antagonist W7 on the inositol phosphate turnover of RINm5F cells was studied. Inositol phosphates were separated using a new modified technique of anion-exchange high performance liquid chromatography (HPLC). It was observed that W7 significantly increased inositol trisphosphate and inositol bisphosphate within 5 and 15 sec, respectively. No changes of inositol phosphates were detected employing W5, a chlorine-deficient analogue of W7 without calmodulin antagonistic action. Our data are in favour of the view that (I) calmodulin may be involved in inositol phosphate metabolism of RINm5F cells and that (II) the increase of [Ca2+]i in response to W7 as reported previously may be due to elevation of inositol trisphosphate.

Prolactin inducible protein in cancer, fertility and immunoregulation: structure, function and its clinical implications

Prolactin inducible protein (PIP) is a 17- kDa single polypeptide chain, known by various names due to its versatile nature and function in human reproductive and immunological systems. It is expressed in several exocrine tissues such as the lacrimal, salivary, and sweat glands. Its expression is up regulated by prolactin and androgens, and estrogens down regulate it. Due to its over-expression in metastatic breast and prostate cancer, presently PIP is considered as a prognostic biomarker. Moreover, its aspartyl-proteinase nature suggests its role in tumor progression. PIP has unique features because it is small in size and plays multiple important functions. Its ability to bind potentially with CD4-T cell receptor, immunoglobulin G (IgG), actin, zinc alpha2-glycoprotein (ZAG), fibronectin and enamel pellicle, reveals its important biological functions. This is the first comprehensive review on the structure and functional analysis of PIP and its clinical applications.

Prevalence of rheumatic heart disease in school children of urban Lahore

OBJECTIVE

To determine the prevalence of rheumatic heart disease (RHD) among school children in urban and semiurban areas of Lahore, Pakistan.

METHODS

A cross-sectional survey of school children aged 5-15 years from 70 schools of urban and semiurban Lahore was carried out by a team of cardiologists. Children were screened by clinical examination and diagnosis confirmed by echocardiography. Sociodemographic data were also collected.

RESULTS

Of 24 980 children screened, 986 (3.9%) had a confirmed cardiac lesion; 546 had RHD, 440 had congenital heart disease. The prevalence of RHD was 21.9/1000 children screened (95% CI 20.1 to 23.7). Their mean (SD) age was 10.7 (2.6) years and the female:male ratio was 1.6:1. Most (92.5%) were unaware of the diagnosis and less than 2% were taking rheumatic prophylaxis. All children belonged to a low socioeconomic group and 67% were undernourished.

CONCLUSION

The prevalence of RHD in the urban school population of Lahore is among the highest in the world. The younger age of onset is a special feature and most are unaware of the diagnosis, and hence not receiving life-saving secondary prophylaxis.

Expression of transmembrane carbonic anhydrases IX and XII in ovarian tumours

AIMS

Carbonic anhydrase (CA) isozymes IX and XII have been suggested to play a role in oncogenic processes. The aim of the present study was to investigate CA IX and XII expression in patients with ovarian tumours.

METHODS AND RESULTS

A series of ovarian tumours was immunostained for CA IX and XII and the results were correlated with histopathological and clinical parameters. Most cases of borderline mucinous cystadenomas, mucinous cystadenocarcinomas and serous cystadenocarcinomas were moderately or strongly positive for CA IX. In malignant tumours, the staining was most prominent in hypoxic regions. Expression of CA XII was detected in all tumour categories, although the mean staining intensity was weaker than for CA IX in all groups except for clear cell carcinomas.

CONCLUSIONS

The wide expression of CA IX and XII in ovarian tumours suggests that these isozymes could represent potential targets in ovarian cancer therapy. The expression pattern of CA IX suggests that it could also serve as a useful histopathological marker protein for hypoxia in malignant ovarian tumours.

Sodium and potassium excretion in normotensive and hypertensive population in Kashmir

One hundred thirty five hypertensive patients and equal number of age and sex matched healthy controls were taken up for studying the relationship of 24 hour urinary sodium and potassium excretion, sodium-potassium molar ratio and body mass index (BMI) with blood pressure in normotensive and hypertensive population in Kashmir. There was statistically significant elevated 24 hour urinary sodium excretion (p < .001), increased Na+-K+ molar ratio, significantly higher BMI in hypertensive population as compared to controls whereas there was a lower 24 hour urinary excretion of potassium (p > .20) in patients with hypertension. Thus sodium and potassium excretion, Na+-K+ molar ratio and body mass index has direct bearing in perpetuation or causation of hypertension in Kashmir which may be related to intake of salt tea.

Cardiovascular health--behaviour of medical students in Karachi

OBJECTIVE

To assess the health behaviour and perceptions of medical students towards cardiovascular disease.

METHODS

This descriptive cross-sectional survey was conducted on 203 Pakistani medical students enrolled in a private medical college in Karachi, Pakistan using systematic random sampling. It was based on a self-administered questionnaire.

RESULTS

Eight percent smoked, 9% were overweight, 33% had a family history of coronary artery disease, 32% regulated dietary fat intake, 28% exercised regularly, 62.1% knew personal blood pressure and 5.4% personal cholesterol levels. Regarding developing cardiovascular disease in the future, 62% showed concern but only 54% of these adopted preventive practices. About 46% believed medical college life had a harmful effect on their health. Gender, family history and personal health status perception were behavior modifying influences (p<0.05). Reasons reported for their behavior were: no need of prevention at their age (38.3%) and never thinking about these issues (37.0%).

CONCLUSIONS

The study shows a high prevalence of coronary artery disease family history, inappropriate dietary intake, physical inactivity; poor screening practices and lack of awareness. The results underscore the urgent need to promote preventive knowledge and practices among medical students, if they are to become prevention oriented physicians and counsel patients on preventive strategies to counter the rapidly increasing burden of cardiovascular diseases effectively.

Effect of purinergic agonists and antagonists on insulin secretion from INS-1 cells (insulinoma cell line) and rat pancreatic islets

The effects of purinergic agonists on insulin release are controversial in the literature. In our studies (mainly using INS-1 cells, but also using rat pancreatic islets), ATP had a dual effect on insulin release depending on the ATP concentration: increasing insulin release (EC50 approximately/= 0.0032 microM) and inhibiting insulin release (EC50 approximately/= 0.32 microM) at both 5.6 and 8.3 mM glucose. This is compatible with the view that either two different receptors are involved, or the cells desensitize and (or) the effect of an inhibitory degradation product such as adenosine (ectonucleotidase effect) emerges. The same dual effects of ATP on insulin release were obtained using rat pancreatic islets instead of INS-1 cells. ADPbetaS, which is less degradable than ATP and rather specific for P2Y1 receptors, had a dual effect on insulin release at 8.3 mM glucose: stimulatory (EC50 approximately/= 0.02 microM) and inhibitory (EC50 approximately/= 0.32 microM). The effectiveness of this compound indicates the possible involvement of a P2Y1 receptor. 2-Methylthio-ATP exhibited an insulinotropic effect at very high concentrations (EC50 approximately/= 15 microM at 8.3 mM glucose). This indicated that distinct P2X or the P2Y1 receptor may be involved in these insulin-secreting cells. UTP increased insulin release (EC50 approximately/= 2 microM) very weakly, indicating that a P2U receptor (P2X3 or possibly a P2Y2 or P2Y4) are not likely to be involved. Suramin (50 microM) antagonized the insulinotropic effect of ATP (0.01 microM) and UTP (0.32 microM). Since suramin is not selective, the data indicated that various P2X and P2Y receptors may be involved. PPADS (100 microM), a P2X and P2Y1,4,6 receptor antagonist, was ineffective using either low or high concentrations of ATP and ADPbetaS, which combined with the suramin data hints at a P2Y receptor effect of the compounds. Adenosine inhibited insulin release in a concentration-dependent manner. DPCPX (100 microM), an adenosine (A1) receptor antagonist, inhibited the inhibitory effects of both adenosine and of high concentrations of ATP. Adenosine deaminase (1 U/mL) abolished the inhibitory effect of high ATP concentrations, indicating the involvement of the degradation product adenosine. Repetitive addition of ATP did not desensitize the stimulatory effect of ATP. U-73122 (2 microM), a PLC inhibitor, abolished the ATP effect at low concentrations. The data indicate that ATP at low concentrations is effective via P2Y receptors and the PLC-system and not via P2X receptors; it inhibits insulin release at high concentrations by being metabolized to adenosine.

Molecular aspects of iron absorption and HFE expression

Hereditary hemochromatosis, a disease of iron overload, occurs in about 1 in 200-400 Caucasians. The gene mutated in this disorder is termed HFE. The product of this gene, HFE protein, is homologous to major histocompatibility complex class I proteins, but HFE does not present peptides to T cells. Based on recent structural, biochemical, and cell biological studies, transferrin receptor (TfR) is a ligand for HFE. This association directly links HFE protein to the TfR-mediated regulation of iron homeostasis. Although evidence is accumulating that binding of HFE to TfR is critical for the effects of HFE, the final pieces in the HFE puzzle have not been established. This review focuses on recent advances in HFE research and presents a hypothetical model of HFE function.

The biosynthesis of prostate-specific antigen in non prostatic cell lines

The biosynthesis of prostate specific antigen (PSA) was studied in human epidermoid carcinoma, (KB) cells and in normal human embryonic lung (WI-38)cells. The prostate carcinoma cell line, PC-35F12 was used as a control. PSA specific antibodies were used to precipitate the immunologically reactive peptides from cell extracts and conditioned media. The immunoprecipitates were analyzed by electrophoresis followed by fluorgraphy. Human PSA is initially synthesized as 32-kDa secretory glycopeptide containing one N-linked oligosaccharide and then processed to a 34-kDa secretory glycoprotein in KB cells. PSA is also expressed in normal human embryonic lung cells, WI-38. These results confirm that PSA expression is not prostate specific, but is also found in some nonprostatic cells. From these results, we conclude that PSA may play an important physiologic role in several tissues.

Synthesis and hypoglycemic activity of some new flavone derivatives. 4th communication: 6-flavonyl-2,4-thiazolidinediones

A new series of flavonyl compounds (1-10) was prepared and tested for their insulinotropic activities in INS-1 cells. Compounds 2, 5 and 6 (at higher concentrations) and compounds 3 and 7-10 were able to increase insulin release in the presence of 5.6 mmol/l glucose at both concentrations used (1 and 10 micrograms/ml).