Time trends in the incidence of cancer cervix in Karachi South, 1995-2002

Introduction:The objective of the study was to determine the trends of cancer cervix in Karachi South during an eight (1995-2002) year period. Methododology: Cancer cervix cases recorded at Karachi Cancer Registry during 1st January 1995 to 31st December 2002 were analyzed. Trends were studied by analyzing the age standardized incidence rates (ASR)s in 2 time periods, 1995-97 and 1998-2002. Results: Cancer cervix ranked sixth in the 1995-97 period the age standardized incidence rate (ASR) world and crude incidence rate (CIR) per 100,000 were 6.81 and 3.22. It reached the fifth ranking in the 1998-2002 period with an ASR and CIR of 7.5 and 4.0 per 100,000. Thus between 1995 and 2002, the incidence of cervical cancer registered an approximate 10% increase. The mean age of the cancer cases was 53.3 years (SD 11.6, 95% CI 50.58, 55.96, range 32-85 years) and 50.7 years (SD 11.7, 95% CI 48.8, 52.5, range 51 years) in period 1 and 2 respectively. The morphological components of squamous cell carcinoma and adenocarcinoma remained stable during this period, though a marginally higher component and increasing incidence of adenocarcinoma was observed throughout. A negligible down staging was observed in the 1998-2002 period. Localized malignancy was observed in 30.8% in period 2 as compared to 25.7% in period 1 and the component of carcinoma in situ increased from 0% percent in period 1 to 1.3% in the second period. Despite this two thirds of the cases still presented with a regional or distant spread of disease. Conclusion: Pakistan at present falls into a low risk cancer cervix region. The cause of concern is the steadily increasing incidence especially in the younger birth cohorts, the advanced disease at presentation, insignificant in-situ cancers and no preventive intervention or awareness practices in place

Digital pathology for reporting histopathology samples, including cancer screening samples – definitive evidence from a multisite study

Aims To conduct a definitive multicentre comparison of digital pathology (DP) with light microscopy (LM) for reporting histopathology slides including breast and bowel cancer screening samples. Methods A total of 2024 cases (608 breast, 607 GI, 609 skin, 200 renal) were studied, including 207 breast and 250 bowel cancer screening samples. Cases were examined by four pathologists (16 study pathologists across the four speciality groups), using both LM and DP, with the order randomly assigned and 6 weeks between viewings. Reports were compared for clinical management concordance (CMC), meaning identical diagnoses plus differences which do not affect patient management. Percentage CMCs were computed using logistic regression models with crossed random-effects terms for case and pathologist. The obtained percentage CMCs were referenced to 98.3% calculated from previous studies. Results For all cases LM versus DP comparisons showed the CMC rates were 99.95% [95% confidence interval (CI) = 99.90–99.97] and 98.96 (95% CI = 98.42–99.32) for cancer screening samples. In speciality groups CMC for LM versus DP showed: breast 99.40% (99.06–99.62) overall and 96.27% (94.63–97.43) for cancer screening samples; [gastrointestinal (GI) = 99.96% (99.89–99.99)] overall and 99.93% (99.68–99.98) for bowel cancer screening samples; skin 99.99% (99.92–100.0); renal 99.99% (99.57–100.0). Analysis of clinically significant differences revealed discrepancies in areas where interobserver variability is known to be high, in reads performed with both modalities and without apparent trends to either. Conclusions Comparing LM and DP CMC, overall rates exceed the reference 98.3%, providing compelling evidence that pathologists provide equivalent results for both routine and cancer screening samples irrespective of the modality used

Color Enhancement in Endoscopic Images Using Adaptive Sigmoid Function and Space Variant Color Reproduction

Modern endoscopes play an important role in diagnosing various gastrointestinal (GI) tract related diseases. The improved visual quality of endoscopic images can provide better diagnosis. This paper presents an efficient color image enhancement method for endoscopic images. It is achieved in two stages: image enhancement at gray level followed by space variant chrominance mapping color reproduction. Image enhancement is achieved by performing adaptive sigmoid function and uniform distribution of sigmoid pixels. Secondly, a space variant chrominance mapping color reproduction is used to generate new chrominance components. The proposed method is used on low contrast color white light images (WLI) to enhance and highlight the vascular and mucosa structures of the GI tract. The method is also used to colorize grayscale narrow band images (NBI) and video frames. The focus value and color enhancement factor show that the enhancement level in the processed image is greatly increased compared to the original endoscopic image. The overall contrast level of the processed image is higher than the original image. The color similarity test has proved that the proposed method does not add any additional color which is not present in the original image. The algorithm has low complexity with an execution speed faster than other related methods

Ca2+ phase waves: a basis for cellular pacemaking and long-range synchronicity in the guinea-pig gastric pylorus

Ca2+ imaging and multiple microelectrode recording procedures were used to investigate a slow wave-like electrical rhythmicity in single bundle strips from the circular muscle layer of the guinea-pig gastric pylorus. The ‘slow waves’ (SWs) consisted of a pacemaker and regenerative component, with both potentials composed of more elementary events variously termed spontaneous transient depolarizations (STDs) or unitary potentials. STDs and SW pacemaker and regenerative potentials exhibited associated local and distributed Ca2+ transients, respectively. Ca2+ transients were often larger in cellular regions that exhibited higher basal Ca2+ indicator-associated fluorescence, typical of regions likely to contain intramuscular interstitial cells of Cajal (ICCIM). The emergence of rhythmicity arose through entrainment of STDs resulting in pacemaker Ca2+ transients and potentials, events that exhibited considerable spatial synchronicity. Application of ACh to strips exhibiting weak rhythmicity caused marked enhancement of SW synchronicity. SWs and underlying Ca2+ increases exhibited very high ‘apparent conduction velocities’ (‘CVs’) orders of magnitude greater than for sequentially conducting Ca2+ waves. Central interruption of either intercellular connectivity or inositol 1,4,5-trisphosphate receptor (IP3R)-mediated store Ca2+ release in strips caused SWs at the two ends to run independently of each other, consistent with a coupled oscillator-based mechanism. Central inhibition of stores required much wider regions of blockade than inhibition of connectivity indicating that stores were voltage-coupled. Simulations, made using a conventional store array model but now including depolarization coupled to IP3R-mediated Ca2+ release, predicted the experimental findings. The linkage between membrane voltage and Ca2+ release provides a means for stores to interact as strongly coupled oscillators, resulting in the emergence of Ca2+ phase waves and associated pacemaker potentials. This distributed pacemaker triggers regenerative Ca2+ release and resultant SWs

A theoretical model of slow wave regulation using voltage-dependent synthesis of inositol 1,4,5-trisphosphate.

A qualitative mathematical model is presented that examines membrane potential feedback on synthesis of inositol 1,4,5-trisphosphate (IP(3)), and its role in generation and modulation of slow waves. Previous experimental studies indicate that slow waves show voltage dependence, and this is likely to result through membrane potential modulation of IP(3). It is proposed that the observed response of the tissue to current pulse, pulse train, and maintained current injection can be explained by changes in IP(3), modulated through a voltage-IP(3) feedback loop. Differences underlying the tissue responses to current injections of opposite polarities are shown to be due to the sequence of events following such currents. Results from this model are consistent with experimental findings and provide further understanding of these experimental observations. Specifically, we find that membrane potential can induce, abolish, and modulate slow wave frequency by altering the excitability of the tissue through the voltage-IP(3) feedback loop

Experimental data manipulations to assess performance of hyperspectral classification models of crop seeds and other objects.

BackgroundOptical sensing solutions are being developed and adopted to classify a wide range of biological objects, including crop seeds. Performance assessment of optical classification models remains both a priority and a challenge.MethodsAs training data, we acquired hyperspectral imaging data from 3646 individual tomato seeds (germination yes/no) from two tomato varieties. We performed three experimental data manipulations: (1) Object assignment error: effect of individual object in the training data being assigned to the wrong class. (2) Spectral repeatability: effect of introducing known ranges (0-10%) of stochastic noise to individual reflectance values. (3) Size of training data set: effect of reducing numbers of observations in training data. Effects of each of these experimental data manipulations were characterized and quantified based on classifications with two functions [linear discriminant analysis (LDA) and support vector machine (SVM)].ResultsFor both classification functions, accuracy decreased linearly in response to introduction of object assignment error and to experimental reduction of spectral repeatability. We also demonstrated that experimental reduction of training data by 20% had negligible effect on classification accuracy. LDA and SVM classification algorithms were applied to independent validation seed samples. LDA-based classifications predicted seed germination with RMSE = 10.56 (variety 1) and 26.15 (variety 2), and SVM-based classifications predicted seed germination with RMSE = 10.44 (variety 1) and 12.58 (variety 2).ConclusionWe believe this study represents the first, in which optical seed classification included both a thorough performance evaluation of two separate classification functions based on experimental data manipulations, and application of classification models to validation seed samples not included in training data. Proposed experimental data manipulations are discussed in broader contexts and general relevance, and they are suggested as methods for in-depth performance assessments of optical classification models