Surgical outcome of safe surgery system trabeculectomy combined with cataract extraction.

PURPOSE: To determine the efficacy of safe surgery system trabeculectomy combined with manual small incision cataract surgery/phacoemulsification in primary glaucoma coexistent with cataract. METHODS: This is a retrospective analysis of 105 cases who underwent single-site combined surgery between January 2008 and December 2009. Safe surgery system trabeculectomy with diffuse and posterior application of mitomycin C was performed in all cases. Cataract extraction was done either by Manual Small Incision Cataract Surgery (MSICS) or phacoemulsification. Main outcome measures were success rate of trabeculectomy, as determined by four different IOP goals and incidence of postoperative complications. Analysis was performed using R-2.15, and the significance was tested at 5% level. RESULTS: The minimum follow-up period was 12 months. The overall success rates (with or without medication) when safe surgery system trabeculectomy was combined with MSICS were 91, 70, and 51% for IOP ≤18, ≤15, and ≤12 mm Hg, respectively, and target IOP was achieved in 72% cases. The mean IOP reduction was 43.8% with MSICS and 42.08% with phacoemulsification. The surgical outcome was not significantly different for both techniques. Postoperative complications were infrequent and comparable. CONCLUSION: The Safe Surgery System Trabeculectomy combined with cataract surgery offers excellent IOP control with minimal postoperative complications. It offers an effective and improved solution for primary glaucoma coexistent with cataract found in developing countries.

Self-organizing maps: a tool to ascertain taxonomic relatedness based on features derived from 16S rDNA sequence.

Exploitation of microbial wealth, of which almost 95% or more is still unexplored, is a growing need. The taxonomic placements of a new isolate based on phenotypic characteristics are now being supported by information preserved in the 16S rRNA gene. However, the analysis of 16S rDNA sequences retrieved from metagenome, by the available bioinformatics tools, is subject to limitations. In this study, the occurrences of nucleotide features in 16S rDNA sequences have been used to ascertain the taxonomic placement of organisms. The tetra- and penta-nucleotide features were extracted from the training data set of the 16S rDNA sequence, and was subjected to an artificial neural network (ANN) based tool known as self-organizing map (SOM), which helped in visualization of unsupervised classification. For selection of significant features, principal component analysis (PCA) or curvilinear component analysis (CCA) was applied. The SOM along with these techniques could discriminate the sample sequences with more than 90% accuracy, highlighting the relevance of features. To ascertain the confidence level in the developed classification approach, the test data set was specifically evaluated for Thiobacillus, with Acidiphilium, Paracocus and Starkeya, which are taxonomically reassigned. The evaluation proved the excellent generalization capability of the developed tool. The topology of genera in SOM supported the conventional chemo-biochemical classification reported in the Bergey manual.

Telephonic management of rectal bleeding in young adults: a prospective randomized controlled trial.

OBJECTIVE: The majority of young adults referred with rectal bleeding to a colorectal specialist clinic have a very low risk of serious disease such as cancer, and a high chance of gaining symptom relief by simple dietary changes. To determine whether young low-risk patients with rectal bleeding can be managed with a structured telephonic interview and dietary advice, rather than an outpatient visit. METHOD: A single-blinded, prospective, randomized controlled trial was performed in two stages. Patients under 40 years with rectal bleeding only were offered inclusion. Part-I trial: Patients were interviewed on telephone by the colorectal nurse specialist (CNS) and randomized to receive dietary advice (Advice Group) or not (Control Group). All patients were seen in clinic 6 weeks later by a doctor 'blinded' to their trial status. Part-II trial: Patients were interviewed on telephone by the CNS and again randomized to an Advice Group or a Control Group. The Control Group were seen in clinic 6 weeks later. The Advice Group were telephoned again 6 weeks later, and if their bleeding had stopped, were not brought to clinic. All patients were tracked for a year after the study to ensure no adverse diagnoses came to light. RESULTS: Part-I trial: 63 of 89 eligible patients were contactable and none refused the study. Seventy per cent of the Advice Group compared with 33% (P = 0.001) of the Control Group had symptomatic improvement when seen in clinic. Approximately 30% of each group required further treatment. Part-II trial: 54 of 94 eligible patients were contactable. However a further nine declined to enter the trial; 90% of patients in the Advice Group had improved at 6 weeks as judged by telephone interview compared with 56% of patients in the Control Group (P = 0.024) who were seen in clinic. The 90% of patients who improved in the Advice Group did not need to come to clinic to be seen. In both parts of the trial, the CNS identified a small number of patients with urgent symptoms at interview and brought them to clinic. The majority had anal fissures or haemorrhoids although in Part-II, one patient had ulcerative colitis and one had colorectal cancer. CONCLUSION: Telephonic consultation is an effective way of identifying those patients with urgent symptoms among a cohort of young adults referred to the hospital with rectal bleeding. Telephonic dietary advice leads to resolution of rectal bleeding in the majority of patients without urgent symptoms.

Changing trends in the management of colorectal cancers and its impact on cancer waiting times.

OBJECTIVE: The aim of this study was to compare the differences in the presentation, management and waiting times for new colorectal cancer (CRC) patients over 5 years in a single metropolitan cancer centre. METHODS: A retrospective comparative study of new patients with CRC presenting in the years 1998 and 2003. The groups were compared for referral type, Dukes' stage, site, cancer waiting times and primary treatment. RESULTS: There were 72 new patients in 1998 and 77 in 2003. In 1998 33% were seen urgently and 28% as emergencies whereas in 2003 55% of patients were seen as urgent or target wait patients and 16% as emergencies. The 2-week target for urgent referrals was met in 50% of cases in 1998 and 90% in 2003. In 2003 a higher proportion of patients received adjuvant or neoadjuvant treatment. Stage at diagnosis was similar in both groups, except stage 'D' which was 21% in 1998 and only 12% in 2003. The 31-day Cancer Waiting Time (CWT) target from decision to treat to first treatment would have been met in 81% of cases in 1998 and 79% in 2003. The 62-day overall CWT target from referral to first treatment for urgent GP referrals would have been met in 46% of cases in 1998 and 57% in 2003. CONCLUSION: More CRC patients were referred urgently in 2003. Most, but not all of these were referred as target waits. The time taken for the patient's journey did not improve between the two cohorts, possibly in part, because more complex treatments are now provided. Further work and perhaps new thinking are needed in order to achieve Cancer Waiting Time targets.

Identification of signature and primers specific to genus Pseudomonas using mismatched patterns of 16S rDNA sequences.

BACKGROUND: Pseudomonas, a soil bacterium, has been observed as a dominant genus that survives in different habitats with wide hostile conditions. We had a basic assumption that the species level variation in 16S rDNA sequences of a bacterial genus is mainly due to substitutions rather than insertion or deletion of bases. Keeping this in view, the aim was to identify a region of 16S rDNA sequence and within that focus on substitution prone stretches indicating species level variation and to derive patterns from these stretches that are specific to the genus. RESULTS: Repeating elements that are highly conserved across different species of Pseudomonas were considered as guiding markers to locate a region within the 16S gene. Four repeating patterns showing more than 80% consistency across fifty different species of Pseudomonas were identified. The sub-sequences between the repeating patterns yielded a continuous region of 495 bases. The sub-sequences after alignment and using Shanon's entropy measure yielded a consensus pattern. A stretch of 24 base positions in this region, showing maximum variations across the sampled sequences was focused for possible genus specific patterns. Nine patterns in this stretch showed nearly 70% specificity to the target genus. These patterns were further used to obtain a signature that is highly specific to Pseudomonas. The signature region was used to design PCR primers, which yielded a PCR product of 150 bp whose specificity was validated through a sample experiment. CONCLUSIONS: The developed approach was successfully applied to genus Pseudomonas. It could be tried in other bacterial genera to obtain respective signature patterns and thereby PCR primers, for their rapid tracking in the environmental samples.

Distinguishing features of 16S rDNA gene for five dominating bacterial genus observed in bioremediation.

Defining a microbial community and identifying bacteria, at least at the genus level, is a first step in predicting the behavior of a microbial community in bioremediation. In biological treatment systems, the most dominating groups observed are Pseudomonas, Moraxella, Acinetobactor, Burkholderia, and Alcaligenes. Our interest lies in identifying the distinguishing features of these bacterial groups based on their 16S rDNA sequence data, which could be used further for generating genus-specific probes. Accordingly, 20 sequences representing different species from each genus above were retrieved, which constituted a training set. A 16-dimensional feature vector comprised of transition probabilities of nucleotides was considered and each sampled sequence was expressed in terms of these features. A stepwise feature selection method was used to identify features that are distinct across the species of these five groups. Wilk's lambda selection criterion was used and resulted in a subset with six distinguishing features. The discriminating efficacy of this subset was tested through multiple group discriminant analysis. Two linear composites, as a function of these features, could discriminate the test set of forty-five sequences from these groups with 95% accuracy, thereby ascertaining the relevance of the identified features. The geometric representation of feature correlation in the reduced discriminant space demonstrated the dominance of identified features in specific groups. These features independently or in combination could be used to generate genus-specific patterns to design probes, so as to develop a tracking tool for the selected group of bacteria.

An approach to assess level of satisfaction of the residents in relation to SWM system.

The issue of managing solid waste (SW), especially in the major cities, is of growing concern to the municipal organisations in India. The present performance of the system is recognised to be unsatisfactory. This paper delineates an approach to quantify the satisfaction level of the residents as a measure of performance of the system and also presents a case study in a major city. The results show the validity of the approach.

Quantitative structure-activity relationships based on functional and structural characteristics of organic compounds.

In the present quantitative structure-activity relationship (QSAR) modeling, organic compounds, including priority pollutants, have been considered and classified based on their functional and structural characteristics. Five physico-chemical characteristics have been used to develop a QSAR model for Pimephales promelas, by means of multiple regression analysis. Collinearity diagnostics was carried out using two different approaches based on condition index and K correlation index. The outlier analysis was carried out using the variable subsets obtained through both the approaches. An attempt has been made to justify the deletion of outliers in each group referring to their physico-chemical characteristics. The expressions obtained by using both approaches provide almost the same prediction accuracy, however, the latter approach resulted in expressions with reduced number of molecular descriptors. The QSARs obtained through this exercise would certainly assist in designing environment-friendly molecules with lower toxicity.

Crohn's disease in Jamaica

Twenty patients with Crohn's disease seen in Jamaica over the past 20 years are reviewed. There were 14 women and 6 men. The mean age at presentation was 37m years, and symptoms were present for a mean of 12 months. Fourteen patients presented with lower abdominal pain, and diarrhoea was present in 11. Lower gastrointestinal bleeding was the presenting feature in 2. The distribution of disease was ileal in 6, and 8 had primary colonic involvement. Three patients had ileocolitis and one perianal disease. One had involvement of the entire small intestine and ascending colon and another had skip lesions involving several areas of the small intestine. Surgical resection was performed in 5 patients. Of the 15 patients treated medically, 6 have remained well while 8 had recurrent episodes of relapse. Crohn's disease in an uncommon disorder in Jamaica but should be considered in patients presenting with inflammatory bowel disease