COVID-19 infection analysis framework using novel boosted CNNs and radiological images

COVID-19, a novel pathogen that emerged in late 2019, has the potential to cause pneumonia with unique variants upon infection. Hence, the development of efficient diagnostic systems is crucial in accurately identifying infected patients and effectively mitigating the spread of the disease. However, the system poses several challenges because of the limited availability of labeled data, distortion, and complexity in image representation, as well as variations in contrast and texture. Therefore, a novel two-phase analysis framework has been developed to scrutinize the subtle irregularities associated with COVID-19 contamination. A new Convolutional Neural Network-based STM-BRNet is developed, which integrates the Split-Transform-Merge (STM) block and Feature map enrichment (FME) techniques in the first phase. The STM block captures boundary and regional-specific features essential for detecting COVID-19 infectious CT slices. Additionally, by incorporating the FME and Transfer Learning (TL) concept into the STM blocks, multiple enhanced channels are generated to effectively capture minute variations in illumination and texture specific to COVID-19-infected images. Additionally, residual multipath learning is used to improve the learning capacity of STM-BRNet and progressively increase the feature representation by boosting at a high level through TL. In the second phase of the analysis, the COVID-19 CT scans are processed using the newly developed SA-CB-BRSeg segmentation CNN to accurately delineate infection in the images. The SA-CB-BRSeg method utilizes a unique approach that combines smooth and heterogeneous processes in both the encoder and decoder. These operations are structured to effectively capture COVID-19 patterns, including region-homogenous, texture variation, and border. By incorporating these techniques, the SA-CB-BRSeg method demonstrates its ability to accurately analyze and segment COVID-19 related data. Furthermore, the SA-CB-BRSeg model incorporates the novel concept of CB in the decoder, where additional channels are combined using TL to enhance the learning of low contrast regions. The developed STM-BRNet and SA-CB-BRSeg models achieve impressive results, with an accuracy of 98.01%, recall of 98.12%, F-score of 98.11%, Dice Similarity of 96.396%, and IOU of 98.85%. The proposed framework will alleviate the workload and enhance the radiologist's decision-making capacity in identifying the infected region of COVID-19 and evaluating the severity stages of the disease.

COVID-19 detection and analysis from lung CT images using novel channel boosted CNNs

In December 2019, the global pandemic COVID-19 in Wuhan, China, affected human life and the worldwide economy. Therefore, an efficient diagnostic system is required to control its spread. However, the automatic diagnostic system poses challenges with a limited amount of labeled data, minor contrast variation, and high structural similarity between infection and background. In this regard, a new two-phase deep convolutional neural network (CNN) based diagnostic system is proposed to detect minute irregularities and analyze COVID-19 infection. In the first phase, a novel SB-STM-BRNet CNN is developed, incorporating a new channel Squeezed and Boosted (SB) and dilated convolutional-based Split-Transform-Merge (STM) block to detect COVID-19 infected lung CT images. The new STM blocks performed multi-path region-smoothing and boundary operations, which helped to learn minor contrast variation and global COVID-19 specific patterns. Furthermore, the diverse boosted channels are achieved using the SB and Transfer Learning concepts in STM blocks to learn texture variation between COVID-19-specific and healthy images. In the second phase, COVID-19 infected images are provided to the novel COVID-CB-RESeg segmentation CNN to identify and analyze COVID-19 infectious regions. The proposed COVID-CB-RESeg methodically employed region-homogeneity and heterogeneity operations in each encoder-decoder block and boosted-decoder using auxiliary channels to simultaneously learn the low illumination and boundaries of the COVID-19 infected region. The proposed diagnostic system yields good performance in terms of accuracy: 98.21 %, F-score: 98.24%, Dice Similarity: 96.40 %, and IOU: 98.85 % for the COVID-19 infected region. The proposed diagnostic system would reduce the burden and strengthen the radiologist's decision for a fast and accurate COVID-19 diagnosis.

Attention-guided multi-scale deep object detection framework for lymphocyte analysis in IHC histological images

Tumor-infiltrating lymphocytes are specialized lymphocytes that can detect and kill cancerous cells. Their detection poses many challenges due to significant morphological variations, overlapping occurrence, artifact regions and high-class resemblance between clustered areas and artifacts. In this regard, a Lymphocyte Analysis Framework based on Deep Convolutional neural network (DC-Lym-AF) is proposed to analyze lymphocytes in immunohistochemistry images. The proposed framework comprises (i) pre-processing, (ii) screening phase, (iii) localization phase and (iv) post-processing. In the screening phase, a custom convolutional neural network architecture (lymphocyte dilated network) is developed to screen lymphocytic regions by performing a patch-level classification. This proposed architecture uses dilated convolutions and shortcut connections to capture multi-level variations and ensure reference-based learning. In contrast, the localization phase utilizes an attention-guided multi-scale lymphocyte detector to detect lymphocytes. The proposed detector extracts refined and multi-scale features by exploiting dilated convolutions, attention mechanism and feature pyramid network (FPN) using its custom attention-aware backbone. The proposed DC-Lym-AF shows exemplary performance on the NuClick dataset compared with the existing detection models, with an F-score and precision of 0.84 and 0.83, respectively. We verified the generalizability of our proposed framework by participating in a publically open LYON'19 challenge. Results in terms of detection rate (0.76) and F-score (0.73) suggest that the proposed DC-Lym-AF can effectively detect lymphocytes in immunohistochemistry-stained images collected from different laboratories. In addition, its promising generalization on several datasets implies that it can be turned into a medical diagnostic tool to investigate various histopathological problems. Graphical Abstract.

Malaria Parasite Classification Framework using a Novel Channel Squeezed and Boosted CNN

Malaria is a life-threatening infection that infects the red blood cells (RBCs) that gradually grows throughout the body. The plasmodium parasite is caused by a female anopheles mosquito bite and severely affects numerous individuals within the world every year. Therefore, early detection tests are required to predict infected parasitic cells. The proposed technique exploits deep convolutional neural network (CNN) learning capability to detect the thin-blood smear parasitic patients from healthy individuals. In this regard, the detection is accomplished using a novel STM-SB-RENet block-based CNN that employs the idea of split-transform-merge (STM) and channel Squeezing-Boosting (SB) in a modified fashion. In this connection, a new convolutional block-based STM is developed, which systematically implements region and edge operations to explore the parasitic malaria pattern related to region-homogeneity, structural obstruction, and boundary-defining features. Moreover, the diverse boosted feature maps are achieved by incorporating the new channel SB and Transfer Learning (TL) idea in each STM block at abstract, intermediate, and target levels to capture minor contrast and texture variation between parasitic and normal artifacts. The malaria input images to the proposed models are initially transformed using discrete wavelet transform to generate enhanced and reduced feature space. The proposed architectures are validated using hold-out cross-validation on the National Institute of Health Malaria dataset. The proposed methods outperform the train from scratch, and TL-based fine-tuned existing techniques. The considerable performance (accuracy: 97.98%, sensitivity: 0.988, F-score: 0.980, and AUC: 0.996) of STM-SB-RENet suggests that it can be utilized to screen parasitic malaria patients.

A New Deep Hybrid Boosted and Ensemble Learning-Based Brain Tumor Analysis Using MRI

Brain tumor analysis is essential to the timely diagnosis and effective treatment of patients. Tumor analysis is challenging because of tumor morphology factors like size, location, texture, and heteromorphic appearance in medical images. In this regard, a novel two-phase deep learning-based framework is proposed to detect and categorize brain tumors in magnetic resonance images (MRIs). In the first phase, a novel deep-boosted features space and ensemble classifiers (DBFS-EC) scheme is proposed to effectively detect tumor MRI images from healthy individuals. The deep-boosted feature space is achieved through customized and well-performing deep convolutional neural networks (CNNs), and consequently, fed into the ensemble of machine learning (ML) classifiers. While in the second phase, a new hybrid features fusion-based brain-tumor classification approach is proposed, comprised of both static and dynamic features with an ML classifier to categorize different tumor types. The dynamic features are extracted from the proposed brain region-edge net (BRAIN-RENet) CNN, which is able to learn the heteromorphic and inconsistent behavior of various tumors. In contrast, the static features are extracted by using a histogram of gradients (HOG) feature descriptor. The effectiveness of the proposed two-phase brain tumor analysis framework is validated on two standard benchmark datasets, which were collected from Kaggle and Figshare and contain different types of tumors, including glioma, meningioma, pituitary, and normal images. Experimental results suggest that the proposed DBFS-EC detection scheme outperforms the standard and achieved accuracy (99.56%), precision (0.9991), recall (0.9899), F1-Score (0.9945), MCC (0.9892), and AUC-PR (0.9990). The classification scheme, based on the fusion of feature spaces of proposed BRAIN-RENet and HOG, outperform state-of-the-art methods significantly in terms of recall (0.9913), precision (0.9906), accuracy (99.20%), and F1-Score (0.9909) in the CE-MRI dataset.

Detection of tumour infiltrating lymphocytes in CD3 and CD8 stained histopathological images using a two-phase deep CNN

BACKGROUND

Immuno-score, a prognostic measure for cancer, employed in determining tumor grade and type, is generated by counting the number of Tumour-Infiltrating Lymphocytes (TILs) in CD3 and CD8 stained histopathological tissue samples. Significant stain variations and heterogeneity in lymphocytes' spatial distribution and density make automated counting of TILs' a challenging task.

METHODS

This work addresses the aforementioned challenges by developing a pipeline "Two-Phase Deep Convolutional Neural Network based Lymphocyte Counter (TDC-LC)" to detect lymphocytes in CD3 and CD8 stained histology images. The proposed pipeline sequentially works by removing hard negative examples (artifacts) in the first phase using a custom CNN "LSATM-Net" that exploits the idea of a split, asymmetric transform, and merge. Whereas, in the second phase, instance segmentation is performed to detect and generate a lymphocyte count against the remaining samples. Furthermore, the effectiveness of the proposed pipeline is measured by comparing it with the state-of-the-art single- and two-stage detectors. The inference code is available at GitHub Repository https://github.com/m-mohsin-zafar/tdc-lc.

RESULTS

The empirical evaluation on samples from LYSTO dataset shows that the proposed LSTAM-Net can learn variations in the images and precisely remove the hard negative stain artifacts with an F-score of 0.74. The detection analysis shows that the proposed TDC-LC outperforms the existing models in identifying and counting lymphocytes with high Recall (0.87) and F-score (0.89). Moreover, the commendable performance of the proposed TDC-LC in different organs suggests a good generalization.

CONCLUSION

The promising performance of the proposed pipeline suggests that it can serve as an automated system for detecting and counting lymphocytes from patches of tissue samples thereby reducing the burden on pathologists.

Assessment of anthropogenic-causing-agents act on waterbirds-diversity in the vicinity of Tarbela Dam, Indus River, Pakistan

Birds are among the best bio-indicators, which can guide us to recognize some of the main conservation concerns in ecosystems. Anthropogenic impacts such as deforestation, habitat degradation, modification of landscapes, and decreased quality of habitats are major threats to bird diversity. The present study was designed to detect anthropogenic causative agents that act on waterbird diversity in Tarbella Dam, Indus River, Pakistan. Waterbird censuses were carried out from March 2019 to February 2020 in multiple areas around the dam. A total of 2990 waterbirds representing 63 species were recorded. We detected the highest waterbird richness and diversity at Pehure whereas the highest density was recorded at Kabbal. Human activity impacts seemed to be the main factor determining the waterbird communities as waterbirds were negatively correlated with the greatest anthropogenic impacts. Waterbirds seem to respond rapidly to human disturbance.

Study of human knowledge and attitude toward urban birds in Faisalabad city, Pakistan

Birds are very valuable indicators of species richness and endemic patterns in a specified ecosystem, which eventually help the scientist to measure the environmental degradation. The aim of present study was to know human knowledge and attitude toward urban birds in Faisalabad city, Pakistan. The study conducted in four consecutive months: November 2019 to February 2020. Population of birds was noted from eight residential towns of Faisalabad city, data were collected through questionnaire. Faisalabad has a reasonably large population of birds and present data show that, there is a significant difference between favorite bird of residential areas and institutions. The pigeon received the most likeness in bird population among residential area residents, while the myna received the least. The most popular bird in Faisalabad institutions was the sparrow, while the least popular bird was the common myna. Bird adaptation percentage of residential areas and institutional areas of Faisalabad was the highest for parrot and sparrow respectively. People in residential areas and institutions, on the other hand, adapted least to common myna. It is concluded that people of the study area like birds and offered food and high population of birds are present in study area.

COVID-19 detection in chest X-ray images using deep boosted hybrid learning

The new emerging COVID-19, declared a pandemic disease, has affected millions of human lives and caused a massive burden on healthcare centers. Therefore, a quick, accurate, and low-cost computer-based tool is required to timely detect and treat COVID-19 patients. In this work, two new deep learning frameworks: Deep Hybrid Learning (DHL) and Deep Boosted Hybrid Learning (DBHL), is proposed for effective COVID-19 detection in X-ray dataset. In the proposed DHL framework, the representation learning ability of the two developed COVID-RENet-1 & 2 models is exploited individually through a machine learning (ML) classifier. In COVID-RENet models, Region and Edge-based operations are carefully applied to learn region homogeneity and extract boundaries features. While in the case of the proposed DBHL framework, COVID-RENet-1 & 2 are fine-tuned using transfer learning on the chest X-rays. Furthermore, deep feature spaces are generated from the penultimate layers of the two models and then concatenated to get a single enriched boosted feature space. A conventional ML classifier exploits the enriched feature space to achieve better COVID-19 detection performance. The proposed COVID-19 detection frameworks are evaluated on radiologist's authenticated chest X-ray data, and their performance is compared with the well-established CNNs. It is observed through experiments that the proposed DBHL framework, which merges the two-deep CNN feature spaces, yields good performance (accuracy: 98.53%, sensitivity: 0.99, F-score: 0.98, and precision: 0.98). Furthermore, a web-based interface is developed, which takes only 5-10s to detect COVID-19 in each unseen chest X-ray image. This web-predictor is expected to help early diagnosis, save precious lives, and thus positively impact society.

Coronavirus disease analysis using chest X-ray images and a novel deep convolutional neural network

Background

The recent emergence of a highly infectious and contagious respiratory viral disease known as COVID-19 has vastly impacted human lives and overloaded the health care system. Therefore, it is crucial to develop a fast and accurate diagnostic system for the timely identification of COVID-19 infected patients and thus to help control its spread.

Methods

This work proposes a new deep CNN based technique for COVID-19 classification in X-ray images. In this regard, two novel custom CNN architectures, namely COVID-RENet-1 and COVID-RENet-2, are developed for COVID-19 specific pneumonia analysis. The proposed technique systematically employs Region and Edge-based operations along with convolution operations. The advantage of the proposed idea is validated by performing series of experimentation and comparing results with two baseline CNNs that exploited either a single type of pooling operation or strided convolution down the architecture. Additionally, the discrimination capacity of the proposed technique is assessed by benchmarking it against the state-of-the-art CNNs on radiologist's authenticated chest X-ray dataset. Implementation is available at https://github.com/PRLAB21/Coronavirus-Disease-Analysis-using-Chest-X-Ray-Images.

Results

The proposed classification technique shows good generalization as compared to existing CNNs by achieving promising MCC (0.96), F-score (0.98) and Accuracy (98%). This suggests that the idea of synergistically using Region and Edge-based operations aid in better exploiting the region homogeneity, textural variations, and region boundary-related information in an image, which helps to capture the pneumonia specific pattern.

Conclusions

The encouraging results of the proposed classification technique on the test set with high sensitivity (0.98) and precision (0.98) suggest the effectiveness of the proposed technique. Thus, it suggests the potential use of the proposed technique in other X-ray imagery-based infectious disease analysis.

Comparison of Outcome of Eclamptic Patient Following Vaginal Delivery versus Caeserian Delivery by Spinal Anaesthesia

Eclampsia is a common problem in pregnancy in Bangladesh. It is a severe form of preeclampsia which affects 5 to 7% of pregnancies is a significant cause of maternal & neonatal morbidity & mortality. Pre-eclampsia when complicated with generalized tonic-clonic convulsions and/or coma is called eclampsia. The term eclampsia is derived from a Greek word, meaning "like a flash of lightening". It may occur quite abruptly, without any warning manifestations. Eclampsia is a major cause of maternal mortality & morbidity as well as foetal loss worldwide, particularly in the third world. Appropriate measures & effective treatment of eclamptic patient in proper time reduce maternal mortality & morbidity. The mainstay of treatment of eclampsia is delivery of the foetus. Two methods are usually applied for delivery of foetus in eclampsia i.e. vaginal delivery & caesarean delivery. This study was done in the department of Gynae & Obs and department of Anaesthesiology, Mymensingh Medical College Hospital from 1st January 2016 to 30th June 2016 to observe the incidence, complications (morbidity) & mortality of eclamptic patients & which method (vaginal delivery versus caesarean delivery by spinal anaesthesia) is safe, better for the eclamptic patients as well as foetal mortality. Successful vaginal delivery is dependant on complex interactions of three variables (3 P) that is power (uterine contraction), passenger (foetus) & passage (birth canal) but power is less effective in eclamptic patient than normal partuents. Vaginal delivery requires prolong times compared with cesarean delivery. Anaesthetic technique is also an important factor for maternal mortality & morbidity of caesarean delivery. Spinal anaesthesia is widely regarded as a reasonable anaesthetic option for caesarean delivery in eclamptic patients. Currently the safety of spinal anaesthesia is well established and it can provide better obstetrical outcome when chosen properly. In this observation caesarean delivery by spinal anesthesia is safer, less complications, less maternal & neonatal mortality than vaginal delivery in eclamptic patients.

Study of Prostatic Volume and its Variations in Different Age Groups of Bangladeshi Cadaver

Benign prostatic hyperplasia and carcinoma of the prostate are the most common disorders of Bangladeshi male in recent years. Volume of the prostate is necessary to estimate the amount of BPH adenoma to determine the appropriate therapy or to select the surgical approach. Transurethral resection of prostate (TURP) is preferred for small glands and open prostatectomy for larger ones. Decrease in prostatic mass after hormonal manipulation or radiation therapy can be used as an indicator of therapeutic efficacy. The effect of prostate volume on biopsy outcome was assessed and was noted that there was an inverse relationship in between size of the gland and prostate cancer. A cross sectional descriptive study was conducted in Department of Anatomy, Mymensingh Medical College, Mymensingh, Bangladesh to find out the difference in volume of the prostate gland of Bangladeshi people in relation to age. The present study was performed on 67 postmortem human prostate gland collected from the morgue in the Department of Forensic Medicine, Mymensingh Medical College by non random purposive sampling technique. The specimens were collected from Bangladeshi cadaver of age ranging from 10 to 80 years. All the specimens were grouped into three categories: Group A (upto 18 years), Group B (19 to 45 years) and Group C (above 45 years) according to age. Dissection was performed according to standard autopsy techniques. The volume of the prostate gland were measured and recorded. The mean volume of the prostate gland was 13.75ml in Group A, 24.44ml in Group B and 29.72ml in Group C. Variance analysis shows that mean differences of volume of the prostate were highly significant among all age groups. The volume of prostate gland was found to be increased with increasing age. For statistical analysis, differences between age groups were analyzed by using students unpaired 't' test. The present study will help to increase the information pool on the volume of prostate gland of Bangladeshi people.

IDENTIFICATION OF QTLs ON CHROMOSOME 1B FOR GRAIN QUALITY TRAITS IN BREAD WHEAT (TRITICUM AESTIVUM L.)

The present study was designed considering the importance of grain quality traits, genetic diversity and marker-trait association analysis in wheat. A significant amount of genetic diversity was found for various seed traits though the genotypes included in the study were found structured. The extent of polymorphism was high with a range of 2-13 alleles and average of 6.5 alleles per locus. Population structure was detected with 30 unlinked SSRs that divided the population of 92 genotypes in three sub-populations. Extensive LD extent was found on chromosome 1B with 42 SSRs specific for 1B chromosome. Marker-trait associations were determined using mixed linear model, where, population structure and kinship calculated on the basis of unlinked markers were covariated with 1B specific markers and traits data. Eight QTLs for five traits including protein, gluten contents, test weight bread and chapati making quality. Protein content, test weight, bread quality and Glu-B1 were found significantly associated with primers WMC419 (32 cM); WMC128 (30 cM), WMC419 (32 cM); WMC818 (17 cM) and WMC416 (44 cM), respectively.

Ambras Syndrome: First Reported Case in Bangladesh and its Oral Rehabilitation

People with rare hypertrichosis syndromes became crowd-drawing money-making phenomena in many 19th century sideshow acts. These individuals have been referred to as dog-men, hair-men, and werewolves. In 1993, Baumister et al. described congenital hypertrichosis lanuginose or Ambras syndrome: a distinct form of congenital hypertrichosis characterized by excessive hair growth over the body and face associated with facial and occasional dental anomalies. Much is not known about this syndrome since fewer than 50 cases have been documented worldwide. In this case report, a nine year old girl presented with excessive hair growth throughout her body that was denser along her midline. Furthermore, her face displayed the typical dysmorphic features characteristic of Ambras syndrome: a round tip nose, thickened nasal cartilage, antiverted nares, prominent philtrum with deep groove, and a trapezoid mouth. Oral examination revealed normal oral mucosa with completely missing and unerupted decidious and permanent teeth. Panoramic radiographs confirmed unerupted deciduous teeth. Previous case reports have mentioned the presence of occasional dental anomalies such as retarded first and second dentition and absence of some teeth. However, this is the first reported case of Ambras syndrome presenting with complete anodontia. Prior cytogenetic studies performed on persons with Ambras syndrome have implicated a balanced pericentric inversion of chromosome 8. However, it is likely that dental anomalies are likely a result of a different genetic rearrangement. Further studies are needed to explore the cause of this rare phenotype of Ambras syndrome with complete unerupted dentition.

Frequency of impaired glucose tolerance and diabetes mellitus in subjects with fasting blood glucose below 6.1 mmol/L (110 mg/dL)

The diagnosis of diabetes mellitus by the available criteria is controversial and relies heavily on fasting glucose results. This cross-sectional study in 2010-2011 aimed to measure the frequency of impaired glucose tolerance and diabetes mellitus in 127 subjects having fasting blood glucose < 7.0 mmol/L and to measure the agreement between different standard diagnostic criteria. Subjects presenting to a laboratory for analysis of fasting blood glucose for excluding diabetes mellitus underwent a 2-hour 75 g oral glucose challenge. A total of 40.6% of subjects with fasting blood glucose from 5.6-6.0 mmol/L had abnormal glucose regulation on the basis ofthe gold standard glucose challenge. Agreement between American Diabetes Association and World Health Organization diagnostic criteria was only fair (kappa = 0.32). Abnormalities of glucose metabolism including impaired glucose tolerance and diabetes mellitus can exist at fasting blood glucose results < 6.1 mmol/L (110 mg/dL).

Elucidation of thermotolerance diversity in cotton (Gossypium hirsutum L.) using physio-molecular approaches

Cotton (Gossypium hirsutum) is an important cash crop, but high temperature during its growing season is one of the major factors that limit its productivity. This problem compels plant breeders to breed for heat tolerance, which can help to overcome this challenge. It is very important to make a comprehensive screening of heat-tolerant genotypes so that only the best are chosen. Here we report the combined use of several techniques that can help breeders to screen their germplasm. Twelve cultivated cotton genotypes were evaluated for thermotolerance, using assays that included electrolyte leakage, chlorophyll accumulation and protein profiling, as well as RAPDs to assess genetic diversity. Two genotypes (B-557 and NIAB-78) showed tolerant behavior in three thermotolerance assays. RAPD analysis results showed maximum similarity in a range of 86.7-66.7% between the genotypes MNH-554 and CIM-443. We conclude that combined use should be made of relative electrolyte leakage, chlorophyll stability and differential display with SDS-PAGE to aid in screening for stress tolerance. RAPD-based diversity analysis will further help to improve the efficiency of breeding programs.

Role of the androgen receptor CAG repeat polymorphism in prostate cancer, and spinal and bulbar muscular atrophy

Androgens are involved in the development of several tissues, including prostate, skeletal muscle, bone marrow, hair follicles, and brain. Most of the biological effects of the androgens are mediated through an intracellular transcription factor, the androgen receptor (AR) at the level of gene regulation. Several types of mutations in the AR gene have been linked to endocrine dysfunctions. The expansion of CAG codon repeat, coding for a polyglutamine (PolyQ) tract in the N-terminal domain is one such mutation. The polyQ chain length impacts AR's ability to interact with critical coregulators, which in turn modulates its transcriptional efficacy. Pathologic manifestations of variations in polyQ chain length have been associated with prostate cancer susceptibility, and the Spinal and Bulbar Muscular Atrophy (SBMA), a neurodegenerative disease. In this review article, we discuss multiple aspects of the role of polyQ chain length in the actions of the AR, their importance in prostate cancer development and progression, and SBMA with an aim to understand the underlying mechanisms involved in these diseases, which can be targeted for future therapeutic approaches.

Radiology reporting: a general practitioner's perspective

Unlike hospital-based clinicians, general practitioners (GPs) lack direct contact with radiologists, and the radiology report is usually the sole method of communication from the radiologist to the GP. It is important to gain feedback regarding what GPs perceive as a good-quality radiology report, especially in the current climate of competition for provision of radiology services. The aims of this study are to determine the level of GP satisfaction with radiology reports, their perception of optimum report content and their preferences regarding the level of detail and report format. A questionnaire was sent to 100 GPs referring to our Trust for radiology services. GPs were generally satisfied with the content and clarity of reports that they receive, and gave suggestions on how reports could be improved. The majority of GPs were unfamiliar with the normal size ranges of frequently measured anatomical structures. Radiologists' recommendations for further treatment, referral and non-radiological investigation were viewed as valuable report components. When asked to rank preferences for ultrasound reports for the same patient with differing formats and levels of detail, GPs favoured detailed reports in a tabulated format. In conclusion, the majority of GPs like detailed reports and value the radiologist's opinion outside the remit of imaging when suggesting further patient management. Reporting the size of a structure without explanation of its significance can potentially cause confusion. It is important to know if GPs are satisfied with the radiology reports they receive so that we can uphold high communication standards and ultimately improve patient care.

Upper lip swelling caused by a large dentigerous cyst with mesiodens

Swelling of upper lip can results from various diseases such as salivary tumors, infections and inflammatory diseases and cyst, typically involving unerrupted teeth, are sometimes associated with supernumerary teeth in the maxillary anterior incisor region called the mesiodens. Mesiodens with dentigerous cyst is actually a rare case in the world and of course in Bangladesh. The overall prevalence of this type of cyst is only 0.15-1.9% of the total population. Recently we have experienced this kind of case like dentigerous cyst with mesiodens in the department of dentistry, Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM) Hospital. The patient was 24 years old male young complaining of slow growing painless swelling on the upper lip region for the last several years. Clinical examination revealed a soft intra oral swelling in the labial surface of maxillary incisor region and there was also extra orally upper lip swelling. Radiographic examination demonstrated a large radiolucent area with a mesiodens extending to the root of both lateral incisors. The patient was treated surgically by enucleation of total cysts and surgical extraction of mesiodens under local anesthesia.

Effects of different osmolytes on the induced folding of the N-terminal activation domain (AF1) of the glucocorticoid receptor

In order to understand gene regulation by glucocorticoids, it is pivotal to know how the major transactivation domain AF1 of the glucocorticoid receptor (GR) functions. Located in the N-terminal region of the GR, AF1 is quantitatively important for transcriptional regulation, but only in recent years have we begun to understand how AF1 works. This is in part due to the fact that the recombinant AF1 (rAF1) peptide exists as a random ensemble of conformers. Algorithms that predict structure support the view that AF1 is also not well ordered in the holo-GR, and the properties of the amino acids in AF1 suggest that it is intrinsically disordered. However, it is generally believed that intrinsically disordered sequences of the GR AF1 must achieve one or more ordered conformation(s) to carry out transactivation activity. Based on our previous published work and available literature, we hypothesize that a confluence of effects that operate under physiological conditions cause functionally active conformation(s) to form in AF1. We have shown that when rAF1 is incubated in increasing concentrations of a naturally occurring osmolyte trimethylamine-N-oxide (TMAO), the peptide folds into functionally active conformation(s) that selectively binds several critical coregulatory proteins. Because cells contain various organic osmolytes whose effects may be cumulative, and in light of cell-specific effects of GR AF1 action, we tested whether it can be folded by other natural organic osmolytes representative of three classes: certain amino acids (proline), methylamines (sarcosine), and polyols (sorbitol). The osmolyte-induced folding of rAF1 shows greatly increased affinity for specific binding proteins, including TATA box-binding protein (TBP), CREB-binding protein (CBP), and steroid receptor coactivator-1 (SRC-1). Consistent with theory and published data with other proteins, our results show that different osmolytes have differential effects on rAF1 folding. The cell-specific functions of the GR AF1--and by extension the AF1s of other nuclear hormone receptors--may in part be affected by the presence and concentrations of particular osmolytes within a particular cellular environment.

Pattern of local relapse of maxillary sinus carcinoma

Maxillary sinus carcinoma (MSC) is a rare disease with a variety of treatment options. The present study was undertaken to review the outcome of patients with treated MSC in order to clarify the factors related to local recurrence by analyzing CT findings. The study group comprised of 47 cases, 40 males and 7 females with a median age of 61 years (range, 40- 84 years) treated between 1988 to 1996 at the department of radiotherapy. CT was taken with a slice thickness of 5 mm and contrast material was routinely used. The mean follow-up period for the group was 45.0 months (range, 3-125 months). The treatment policy was either preoperative radiotherapy of 40Gy/16fr followed by maxillectomy or radical radiotherapy of 65Gy/26fr with partial maxillectomy during the course of radiotherapy. By using CT-simulation, wedge pair techniques were used in most patients with Cobalt or 6MV X-ray machines as treatment sources. Tumor extension was categorized into the following anatomical sites: orbital contents, other paranasal sinuses, posterior wall of the maxillary sinus, pterygoid plate/muscle, nasopharynx, infra-temporal fossa, base of the skull, anterior wall of the maxillary sinus, subcutaneous tissue, cheek mucosa, hard palate and alveolar bone. Local control was computed by using the Kaplan-Meier method and p value was measured by using Chi-squared test. The 5-year overall local control rates for all patients were 56%. The local recurrence was found in 19 of 47 patients (40.4%). Tumors extending to pterygoid plates (n=13) and pterygoid muscles (n=10) showed higher rate of local recurrences as compared to those without extensions (9/13 [69%] vs 10/34 [29%], p<0.02 and 7/10 [70%] vs 12/37 [32%], p<0.05, respectively). Extensions to nasopharynx (6/9, 66%) and base of skull (4/6, 66%) also showed higher rates of recurrence; however, those were not statistically significant. More than 80% of the relapse became manifest within 12 months of diagnosis and isolated local failure was the most common pattern. This analysis indicates that tumor extension to pterygoid plate/muscles, results in higher rates of recurrences. This may due to the difficult surgical accessibility of the tumor. During radiotherapy planning, special emphasis should be given to this sites of tumor extension to avoid possible local recurrence.

Expression of FGFR-2 and FGFR-3 in the normal human fetal orbit

AIMS

To demonstrate the expression patterns of two fibroblast growth factor receptors (FGFR-2 and FGFR-3) in the normal human fetal orbit.

METHODS

6 microm orbital slide sections were prepared from 12 week old human fetal material obtained within established ethical guidelines. Radioactive in situ hybridisation techniques were used to demonstrate the expression patterns of FGFR-2 and FGFR-3 within these sections. Only one foetus had appropriate orbital sections taken.

RESULTS

FGFR-2 was expressed within the extraocular muscles (EOMs) and the optic nerve sheath and to a lesser degree within the orbital periosteal margins and the cranial sutures. FGFR-3 was expressed a lot within the periosteal margins and cranial sutures but not within either the EOMs or the optic nerve sheath.

CONCLUSIONS

FGFR-2 and FGFR-3 are differentially expressed within different orbital components. FGFR-2 gene mutations may be responsible for craniosynostotic syndromes such as Crouzon, Pfeiffer, and Apert, while those in the FGFR-3 gene may cause isolated unicoronal synostosis. EOMs may be histologically abnormal in cases of Apert, Pfeiffer, and Crouzon syndromes but not isolated unicoronal synostosis. The pattern of expression of FGFR-2 in the normal human fetal orbit may explain some of the EOM histological findings seen in some cases of Apert, Pfeiffer, and Crouzon syndromes.

Antiischemic effects of topiramate in a transient global forebrain ischemia model: a neurochemical, histological, and behavioral evaluation

The mechanisms of action of the anticonvulsant topiramate (TPM) are indicative of a potential benefit during cerebral ischemia. TPM was studied in a transient global forebrain ischemia (TGFI) model in gerbils in which 40 mg/kg was administered before or after TGFI. Control groups were administered 0.9% normal saline similarly. The evaluation consisted of neurochemical, histological, and functional analyses. The data obtained indicates that unlike the focal cerebral ischemia model, TPM is not neuroprotective in TGFI. The difference in effect, which may be due to the difference in species or the type of ischemia, points to the need for caution when extrapolating animal data from this drug to humans.

Visual outcomes and amblyogenic risk factors in craniosynostotic syndromes: a review of 141 cases

AIMS

To determine the visual outcome and prevalence of amblyogenic risk factors in children with craniosynostotic syndromes.

METHODS

The case notes of 141 children seen within the craniofacial unit were reviewed and information retrieved on date of birth, age at first and last examination, cycloplegic refraction at last visit, best corrected visual acuity at last visit, horizontal ocular deviation in primary position at first visit, and alphabet pattern if any. The presence of astigmatism, its magnitude, and orientation of axis were determined.

RESULTS

40.3% of patients had 1 dioptre (D) of astigmatism or greater and, of these, 64% had oblique astigmatism in at least one eye. Anisometropia of 1D or more was found in 18% of patients (age matched normals 3.5%). Horizontal strabismus was found in 70% (38% exotropia, 32% esotropia). Visual outcome results showed 39.8% of patients (45 of 113) had visual acuity of 6/12 or worse in their better eye.

CONCLUSION

In the largest study to date a poor visual outcome was shown in children with Crouzon's, Pfeiffer's, Apert's, and Saethre-Chotzen syndromes (39.8% with 6/12 or worse in the better eye) together with significant prevalence of amblyogenic risk factors.

The technique of intracerebral microdialysis

Intracerebral microdialysis is an increasingly popular experimental technique. A brief description of the principles of microdialysis is presented and the terms relevant to the procedure are defined. The methodology involved in conducting intracerebral microdialysis is described in detail. Factors influencing the outcome of analysis such as external stimuli, perfusion fluid, perfusion rate, temperature, probe placement, membrane characteristics, and timing of sample collection are discussed. The importance of maintaining the uniformity of the above-mentioned factors is stressed.

Mechanisms involved in the potentiation of melphalan by the bioreductive compound THNLA-1 in vitro

9-[3-(2-Nitro-1-imidazolyl)propylamino]-1,2,3,4-tetrahydroacridine hydrochloride (THNLA-1) is a 2-nitroimidazole-based, weakly DNA-intercalating bioreductive agent that significantly potentiates the toxic effects of commonly used antitumor drugs such as melphalan (L-PAM) or cis-DDP in sensitive or resistant cell lines in culture, as well as in solid tumors in mice. Potentiation in vitro was observed when cells were preexposed to THNLA-1 under hypoxic conditions before exposure to L-PAM under aerobic conditions. In this study we investigated possible mechanisms involved in the potentiation of L-PAM by THNLA-1 in V79 Chinese hamster cells. Limited depletion of glutathione with buthionine sulfoximine or THNLA-1 under hypoxic pretreatment conditions accounted for only 8.3% of the potentiation induced by THNLA-1. However, DNA, RNA, and protein synthesis were inhibited in a synergistic way in cells preexposed to THNLA-1 under hypoxic conditions (2 h, 37 degrees C) and then coexposed to various doses of L-PAM under aerobic conditions (1 h, 37 degrees C). Cell cycle analysis by flow cytometry showed a slow traverse through the S phase in the L-PAM-alone-treated cells. However, this phenomenon was more prominent in the THNLA-1 plus L-PAM-treated cells. Under aerobic co-incubation conditions with L-PAM, no difference was observed in the cell cycle of L-PAM-alone-treated cells vs. THNLA-1 plus L-PAM-treated cells. Significantly increased apoptosis was observed in the hypoxia-pretreated cells with THNLA-1, 12 and 24 h posttreatment. Comet and alkaline elution assay analysis showed increased DNA cross-links in the hypoxia-pretreated cells with THNLA-1 compared to the L-PAM-alone-treated cells. Finally, potential lethal damage repair was totally suppressed only in the hypoxia-pretreated cells with THNLA-1. In conclusion, DNA damage and hindrance in its repair are the most important mechanisms in the potentiation of L-PAM by THNLA-1, under hypoxic pretreatment conditions.

Tibial plateau fractures. A new classification scheme

Fractures of the tibial plateaus are common injuries. Various classification schemes have been used to describe these injuries. Although each system has its own purpose, the simpler systems do not allow comparison with more complex divisions. The problem is compounded by the variable use of adjectives that describe these fractures. A comprehensive classification of tibial plateau fractures should group fractures that are similar in topography, morphology, and pathogenesis, requiring similar treatment, and having a similar prognosis. Fracture dislocations and standard tibial plateau fractures should be incorporated into a single classification to avoid the use of two complementary classifications. Any such classification should not be difficult to remember or to use. Keeping in mind these requirements, the authors devised a simple yet comprehensive classification. The authors studied 80 cases of tibial plateau fractures from January 1988 to September 1997, and used contemporary classifications of tibial plateau fractures as a database to formulate the new classification. A new fracture, subcondylar bicondylar with coronal split, has been classified for the first time. An alphanumeric system has been developed that has made nomenclature easy to remember and use. An effort has been made to address the profoundly confusing issue of variable adjectives that describe these injuries. A review of the literature shows that fractures in the authors' classification have been grouped according to similar pathomechanics, treatment, and functional results.

Evaluation of an optimal temperature for brain storage in delayed 2, 3,5-triphenyltetrazolium chloride staining

This paper presents the determination of an optimal temperature for delayed 2,3,5-triphenyltetrazolium chloride (TTC) staining. Twenty-one rats were subjected to right middle cerebral artery embolic stroke and sacrificed 96 h following ischemia. The brains were harvested and stained immediately after sacrifice or stored for 8 h at 21-23 degrees C or 4 degrees C, respectively. The stained sections were scanned and infarct volume calculated. The quality of staining, distinction of borders between infarcted and non-ischemic tissue and ease of differentiating ischemic tissue in colored and grayscale images was assessed. The present study indicates that results of TTC obtained immediately after animal sacrifice, or delayed TTC staining while storing the brains at room temperature or 4 degrees C are comparable.

Differential requirement for p19ARF in the p53-dependent arrest induced by DNA damage, microtubule disruption, and ribonucleotide depletion

p19ARF has been implicated as a key regulator of p53 stability and activation. While numerous stresses activate the p53 growth arrest pathway, those requiring p19ARF remain to be elucidated. We used p19ARF knockout mouse embryo fibroblasts to show that DNA damage and microtubule disruption require p19ARF to induce p53 responses, whereas ribonucleotide depletion and inhibition of RNA synthesis by low doses of actinomycin D do not. The data provide evidence that the arrest pathway activated by ribonucleotide depletion involves some different signal transducers than those activated by DNA damage or microtubule disruption. We also present biochemical analyses that provide insights into the mechanism by which p53 and p19ARF cooperate in normal cells to induce cell cycle arrest.

The role of taurine in neuronal protection following transient global forebrain ischemia

Osmoregulation and post ischemic glutamate surge suppression (PIGSS) are important mechanisms in the neuroprotective properties of taurine. We studied the role of taurine in PIGSS following transient global forebrain ischemia (TGFI). A group of gerbils received a high dose of continuous intracerebral taurine during the peri-ischemic period. Beta-alanine was given similarly to a negative control group. The control group consisted of animals undergoing only TGFI. On the fourth day following commencement of drug administration, TGFI was induced. Concurrently, half the animals from each group receiving an agent had intracerebral microdialysis. All animals underwent histological assessment at day 7. The microdialysis and histological data was analyzed. Our results showed that taurine treatment did not cause PIGSS. The histological difference between the three groups was statistically insignificant. We conclude that intracerebral taurine in the dosage administered during peri-ischemic period, does not result in PIGSS or histologically evident neuroprotection.

Evidence that Watermelon Leaf Curl Disease in Pakistan Is Associated with Tomato Leaf Curl Virus-India, a Bipartite Begomovirus

Whitefly-transmitted geminiviruses (begomoviruses) have emerged as major constraints on food and fiber crops worldwide, and there are several examples of begomovirus mobilization in previously unknown host plants. Here we report on evidence that leaf curl disease of watermelon in Pakistan is caused by Tomato leaf curl virus-India (TLCV-India). Leaf curl disease of watermelon, characterized by leaf curling and mottling and stunted plant growth, was observed at several locations in the Punjab Province of Pakistan. Symptomatic and asymptomatic leaf samples were collected from three locations, and total DNA was isolated by the cetyltrimethylammoniumbromide method and resolved in agarose gel. A full-length clone of Cotton leaf curl virus DNA A was labeled with ^[32P]dCTP and used as a general probe in Southern hybridization. The probe detected characteristic geminivirus DNA forms in infected watermelon plants, whereas no signal was detected in asymptomatic plants. The association of a begomovirus was confirmed further by polymerase chain reaction (PCR) amplification with degenerate primers PAL1V and pAR1c (2). Samples were screened for infection by TLCV-India, because of symptom similarity. A full-length clone of DNA B of TLCV-India (1) was labeled with ^[32P]dCTP by random priming and was used as a specific probe in Southern hybridization. The probe detected geminivirus DNA forms, showing that the disease is associated with TLCV-India. Primers TLCV1 (GAGGTACCAAAACTTGTCGTTTTGATTCGG), in the virion-sense, and TLCV2 (GCCCATGGTTCTTTGCTCGGAGAACAAGAA), in the complementary-sense, were designed based on the sequence of DNA A of TLCV-India. These primers were used in PCR and amplified a product of the expected size from infected plants. Similarly, primers TLCVBC1 (GCGGATCCTTATTCCGTAATTATATCTGCA), in the virion-sense, and TLCV BC2 (CACCATGGCAATAGGAAATGATGGTATGGG), in the complementary-sense, were designed based on the sequence of DNA B of TLCV-India (1). These primers amplified a product of expected size when used in PCR. The results show that watermelon leaf curl disease in Pakistan is associated with TLCV-India. This the first report of detection of a begomovirus in watermelon in Pakistan and the first report of detection of TLCV-India on a plant other than tomato from Southeast Asia. References: (1) M. Padidam et al. J. Gen. Virol. 76:25, 1995. (2) M. R. Rojas et al. Plant Dis. 77:340, 1993.

Association of a Begomovirus and Nanovirus-like Molecule with Ageratum Yellow Vein Disease in Pakistan

Whitefly-transmitted geminiviruses (begomoviruses) cause heavy losses to many food and fiber crops in Pakistan. Many weeds also show symptoms typical of begomoviruses. Ageratum (Ageratum conyzoides) is a common perennial weed in Pakistan, growing along irrigation canals, that often shows symptoms, such as yellow vein and mosaic, suggesting infection by a begomovirus. To confirm this, symptomatic and asymptomatic ageratum plants were collected from three locations in the Punjab Province of Pakistan, and total DNA was isolated, subjected to agarose gel electrophoresis, transferred to a nylon membrane, and Southern blotted. Total DNA isolated from cotton infected with Cotton leaf curl virus (CLCuV), tomato infected with Tomato leaf curl virus from Pakistan (TLCV-Pak), tobacco infected with African cassava mosaic virus (ACMV) from Nigeria, and healthy tobacco were included as controls. A full-length clone of CLCuV DNA A was labeled with ^[32P]dCTP by oligo-labeling and hybridized at medium stringency. The probe detected characteristic geminivirus DNA forms in symptomatic ageratum and plants infected with CLCuV, TLCV-Pak, and ACMV, while no signal was detected in asymptomatic ageratum from the field or healthy tobacco. To confirm infection by a begomovirus, degenerate primers WTGF (5'-GATTGTACGCGTCCDCCTTTAATTT GAAYBGG-3'), designed in the rep gene of begomoviruses, and WTGR (5'-TANACGCGTGGC TTCKRTACATGGCCTDT-3'), designed in the coat protein gene of DNA A of begomoviruses, were used in polymerase chain reaction (PCR). Degenerate primers (PBLv2040 and PCRc1) also were used in PCR (2). A product of expected size (≈1.4 kb) was obtained with DNA A primers from symptomatic ageratum, while no product was obtained with DNA B primers in the same sample. Previously we were unable to detect a DNA component equivalent to begomovirus DNA B in cotton showing symptoms of cotton leaf curl disease (1). We recently reported a novel circular DNA molecule that was approximately half as long as the full-length DNA A (CLCuV DNA-1) associated with CLCuV that share homology to plant nanoviruses (1). The supercoiled replicative form of viral DNA isolated from infected ageratum plants indicated the presence of smaller molecules, as was found in cotton leaf curl disease, suggesting that a nanovirus-like molecule might be associated with ageratum yellow vein disease. A duplicate blot of samples used in Southern hybridization with the DNA A probe was prepared, and a probe of the full-length clone of the nanovirus-like molecule (CLCuV DNA-1) was prepared as described for DNA A. The probe detected characteristic nanovirus DNA forms in ageratum with yellow vein symptoms and cotton infected with CLCuV, while no signal was detected in plants infected with TLCV-Pak or ACMV, healthy tobacco, or asymptomatic ageratum. Abutting primers PB2-F and PB2R (1), designed based on the CLCuV DNA-1 sequence, were unable to amplify a PCR product from ageratum with yellow vein symptoms, suggesting the nanovirus-like molecule associated with ageratum yellow vein disease is distinct from CLCuV DNA-1. Our results show that yellow vein disease of ageratum in Pakistan is associated with a begomovirus infection and single-stranded circular DNA molecule with similarity to CLCuV DNA-1. References: (1) S. Mansoor et al. Virology 259:190, 1999. (2) M. R. Rojas et al., Plant Dis. 77:340, 1993.

p53 regulation by post-translational modification and nuclear retention in response to diverse stresses

p53 activation by diverse stresses involves post-translational modifications that alter its structure and result in its nuclear accumulation. We will discuss several unresolved topics regarding p53 regulation which are currently under investigation. DNA damage is perhaps the best-studied stress which activates p53, and recent data implicate phosphorylation at N-terminal serine residues as critical in this process. We discuss recent data regarding the potential kinases which modify p53 and the possible role of the resulting phosphorylation events. By contrast, much less is understood about agents which disrupt the mitotic spindle. The cell cycle phase, induction signal, and biochemical mechanism of the reversible arrest induced by microtubule disruption are currently under investigation. Finally, a key event in response to any genotoxic stress is the accumulation of p53 in the nucleus. The factors which determine the steady state level of p53 are starting to be elucidated, but the mechanisms responsible for nuclear accumulation and nuclear export remain controversial. We discuss new studies revealing a mechanism for nuclear retention of p53, and the potential contributions of MDM2 to this process.

Identification of a novel circular single-stranded DNA associated with cotton leaf curl disease in Pakistan

Recent reports have suggested that cotton leaf curl virus (CLCuV), a geminivirus of the genus Begomovirus, may be responsible for cotton leaf curl disease in Pakistan. However, the causal agent of the disease remains unclear as CLCuV genomic components resembling begomovirus DNA A are unable to induce typical disease symptoms when reintroduced into plants. All attempts to isolate a genomic component equivalent to begomovirus DNA B have been unsuccessful. Here, we describe the isolation and characterisation of a novel circular single-stranded (ss) DNA associated with naturally infected cotton plants. In addition to a component resembling DNA A, purified geminate particles contain a smaller unrelated ssDNA that we refer to as DNA 1. DNA 1 was cloned from double-stranded replicative form of the viral DNA isolated from infected cotton plants. Blot hybridisation using probes specific for either CLCuV DNA or DNA 1 was used to demonstrate that both DNAs co-infect naturally infected cotton plants from different geographical locations. DNA 1 was detected in viruliferous Bemisia tabaci and in tobacco plants infected under laboratory conditions using B. tabaci, indicating that it is transmitted by whiteflies. Sequence analysis showed that DNA 1 is approximately half the size of CLCuV DNA but shares no homology, indicating that it is not a defective geminivirus component. DNA 1 has some homology to a genomic component of members of Nanoviridae, a family of DNA viruses that are normally transmitted by aphids or planthoppers. DNA 1 encodes a homologue of the nanovirus replication-associated protein (Rep) and has the capacity to autonomously replicate in tobacco. The data suggest that a nanovirus-like DNA has become whitefly-transmissible as a result of its association with a geminivirus and that cotton leaf curl disease may result from a mutually dependent relationship that has developed between members of two distinct DNA virus families that share a similar replication strategy.

In-situ hybridization localized MUC7 mucin gene expression to the mucous acinar cells of human and MUC7-transgenic mouse salivary glands

MUC7 gene that encodes the low molecular weight human salivary mucin MG2, was previously shown to be expressed in tissue-specific manner in normal human salivary glands and in salivary glands of transgenic mice carrying the MUC7 transgene. The purpose of this study was to examine the cell specificity of MUC7 expression in human and transgenic mice salivary glands. To localize the MUC7 transcripts, we used in-situ hybridization in combination with Tyramide Signal Amplification procedure. The results clearly showed that in both the human and transgenic mice salivary gland tissue sections, MUC7 transcripts were localized only in mucous acinar cells; no signals were found in serous acinar cells or any other cell types present in these salivary glands.

Comparison of percutaneous ventriculostomies and intraparenchymal monitor: a retrospective evaluation of 156 patients

Intraventricular catheters (IVC) and Intraparenchymal fiberoptic catheters (IPC) are the prevalent methods of intracranial pressure (ICP) monitoring. This study assesses the complications caused by either method. Previous studies have shown a higher complication rate with IVC. In 156 consecutive patients, with IVC (n = 104) or IPC (n = 52) insertion, the demographics, Glasgow coma score (GCS), ICP, duration of monitoring, changes in monitoring device, complications and computerized tomography findings, were recorded. The patients were categorized into severe (GCS 3-8), moderate (GCS 9-12) and mild (GCS 13-15) groups. A retrospective, comparative analysis of both techniques was conducted, using Kruskal-Wallis one way analysis of variance with chi square approximation and Mann-Whitney U tests. The use of IPC at 86.5% predominated in patients with GCS 3-8, while IVC at 81.4% and 92% prevailed in GCS groups 9-12 and 13-15, respectively (p = 0.000). 43.2% IVC were used for 10+ days and 25.9% for 1-3 days, while 80% of IPC were used for less than 6 days (p = 0.000). The complication rate for IVC and IPC was 25% vs 4.4% (p = 0.000). The infection rate was 4.4% and 0.6% (p = 0.1) while, inadvertent removal 4.4% vs 1.2% (p = 0.4), respectively. Malpositions occurred only with IVC (20.1%). All documented complications were without untoward clinical sequelae. We conclude that, IVC remains comparable to IPCs in complications.

Dual-isotope protocol for indium-111 capromab pendetide monoclonal antibody imaging

OBJECTIVE

A dual-isotope imaging protocol using 99mTc-labeled red blood cells with 111In capromab pendetide monoclonal antibody imaging for detective and localizing nodal metastasis in prostate cancer is described.

METHODS

This protocol involves a single SPECT acquisition that is less time consuming and more comfortable for the patient than the currently recommended method, which requires two separate SPECT acquisitions performed on different days.

RESULTS

Forty patients were studied with the dual-isotope protocol. Preliminary data suggest increased accuracy compared with the single-isotope technique.

CONCLUSION

The dual-isotope technique assures the precise image registration needed for accurate comparison of blood pool and pelvic lymph node activity that is required for confident and accurate image interpretation.

Training and retaining Shasthyo Shebika: reasons for turnover of community health workers in Bangladesh

Shasthyo Shebikas (SS) are community health workers forming the core of BRAC's Essential Health Care (EHC) programme. The SS dropout was 44 percent for study area and 32 percent for EHC programme. The SS discontinued their work due to lack of time, lack of "profit", and family's disapproval. The effects of the dropouts were decreased achievement of targets, and a loss of money in the amount of $24 (U.S.) per dropout SS for their training and supervision. The SS retention may increase if EHC strictly adheres to its existing guidelines when selecting trainees, and if it highlights during SS training that SS; s first and foremost role will be as that of a volunteer and then of a salesperson.

9-[3-(2-Nitro-1-imidazolyl)propylamino]-cyclopenteno[b]quinoline hydrochloride (NLCPQ-1). A novel DNA-affinic bioreductive agent as chemosensitizer: mechanistic studies. II

NLCPQ-1 is a novel, weak, DNA-affinic bioreductive compound with enhanced chemosensitizing ability for commonly used chemotherapeutic agents, both in vitro and in vivo. In the present report we investigated possible mechanisms involved in the potentiation of cis-DDP and L-PAM in V79 cells. Potentiation was observed when cells were pretreated under hypoxic conditions with NLCPQ-1 prior to their aerobic exposure to each chemotherapeutic agent studied and in the presence of NLCPQ-1. The dominant mechanisms, under hypoxic pretreatment conditions, participating in the potentiation were: a) extensive DNA damage, as measured by the comet and alkaline elution assays, b) DNA, RNA, and protein synthesis inhibition, c) significant delay in the traverse through the S phase, as observed by flow cytometry, and possibly d) suppression of PLD repair. Apoptosis was also detected 36 h posttreatment in the chemotherapeutic drug-treated as well as the combination drug-treated cells. Glutathione depletion by NLCPQ-1 metabolites under hypoxic conditions was also involved in the potentiation process, but its contribution in potentiation was minimal.

p53 and pRb prevent rereplication in response to microtubule inhibitors by mediating a reversible G1 arrest

Cell cycle checkpoints are safeguards that ensure the initiation of downstream events only after completion of upstream processes. The tumor suppressors p53 and pRb prevent initiation of a second round of replication in response to spindle inhibitors, but it has yet to be proven that this is a mitotic checkpoint response. We show that asynchronous human fibroblasts arrest in G1 with 4 N DNA content after nocodazole treatment, whereas isogenic p53- and pRb-deficient fibroblasts rereplicate. Importantly, nocodazole elicits a reversible arrest in G0-G1 synchronized normal human fibroblasts but not in isogenic p53-deficient derivatives. Furthermore, the G1 cyclin-dependent kinase inhibitors p21 and p16 also play critical roles in limiting rereplication. Hence, p53 and pRb are required during G1 to prevent entry into a replicative cycle and appear to provide a connection between the structural integrity of the microtubules and the cell cycle machinery in interphase cells.

New dye-labeled terminators for improved DNA sequencing patterns

We have used two new dye sets for automated dye-labeled terminator DNA sequencing. One set consists of four, 4,7-dichlororhodamine dyes (d-rhodamines). The second set consists of energy-transfer dyes that use the 5-carboxy-d-rhodamine dyes as acceptor dyes and the 5- or 6-carboxy isomers of 4'-aminomethylfluorescein as the donor dye. Both dye sets utilize a new linker between the dye and the nucleotide, and both provide more even peak heights in terminator sequencing than the dye-terminators consisting of unsubstituted rhodamine dyes. The unsubstituted rhodamine terminators produced electropherograms in which weak G peaks are observed after A peaks and occasionally C peaks. The number of weak G peaks has been reduced or eliminated with the new dye terminators. The general improvement in peak evenness improves accuracy for the automated base-calling software. The improved signal-to-noise ratio of the energy-transfer dye-labeled terminators combined with more even peak heights results in successful sequencing of high molecular weight DNA templates such as bacterial artificial chromosome DNA.