Central nervous system lymphomas: a histologic and immunophenotypic analysis

Objective: To observe the spectrum of non-Hodkin’s lymphomas involving the central nervous system including morphological subtypes and immunophenotypic status. Setting: Retrospective analysis of eleven years (1986 to 1996) data from surgical pathology files of Department of Pathology. Results: orty-three cases of non-Hodgkin’s lymphomas were diagnosed during the period of eleven years (from 1986 to 1996), all of which were diffuse types. A total of 1177 Central Nervous CNS biopsies were examined, out of which 937 cases were diagnosed as CNS neoplasms, the remaining were non-neoplastic in nature. Among 937 CNS neoplasms, 43 cases (4.6%) were reported as non-Hodgkin’s lymphomas. As most of the cases were outside referrals, the primary or secondary nature of the lymphomatous process could not he assessed. Seventeen cases were intracranial, while 26 cases were spinal in location. Majority of the intracranial Eymphomas were hiopsied from the cereherum (12 cases). Male to female ratio was 1:2. The median age for intracranial lvmphomas was 50 years and for spinal lymphomas 29 years. There were 16 cases (37%) of diffuse large cell lymphomas; 7 cases (16%) of diffuse mixed small and large cell lymphomas; 3 cases (7%) of diffuse large cell immunoblastic lvmphomas; 2 cases (4.6%) of lymphoblastic lymphomas and diffuse small non-cleaved cell lymphomas and one case of small Iyrnphocytic lymphoma and diffuse small cleaved cell Ivmphoma. One case of T cell rich B cell lvmphoma was also diagnosed in the thoracic spine as primary extranodal lymphoma. Eight cases were unclassifiable and in 2 cases the features were suggestive of lymphoma. Immunophenotypic analysis was performed in 20 cases, however, in 2 cases the results were inconclusive. Fifteen cases (83%) showed immunoreactivity for B cell markers and 3 cases showed T cell phenotype out of which one case was lymphoblastic lymphoma. Conclusion: CNS lymphomas were uncommon tumors and comprised 4.6% of the total CNS neoplasms in our study. Moreover, these CNS lymphomas accounted for 2.2% of the total non-Hodgkin’s lvmphomas, including both nodal and extranodal. There was a higher incidence of location of these lymphomas within the spinal cord than brain. Most of the lymphomas were of intermediate or high grade (75%) according to the working phenotype in 84% 3f the lymphomas, in which it was formulation. lmmunophenotypical status revealed B-cell teste

Breast Diseases: a histopathological analysis of 3279 Cases at a Tertiary Care Center in Pakistan

Objective: To know the frequency of breast diseases in Pakistani females. Methods: A retrospective analysis of 3279 breast specimens received over a period of 4 years (1 993-1996) at the department of pathology, the Aga Khan University Hospital. Results: Out of a total of 3279 breast specimens, common breast lesions included infiltrating duct carcinoma 37%, followed by fibro adenoma 16.95%, fibrocystic change13.96%, mastitis 6.83% and duct ectasia 5.33%. Majority of the cases of infiltrating duct carcinoma were encountered in the 5th and 6th decades of life. Tumour size was 2 or \u3e2 cms. in 93% of cases and 40% of them showed 3 or \u3e3 positive lymph nodes. Grade I tumours were 11.38%, grade 11 59.17% and grade Ill tumours 29.47%. Correlation of grade with lymph node metastases (3 or \u3e3+ve nodes) showed 15 cases (1.53%) of grade 1, 178 cases (18.25%) of grade II and 68(6.97%) cases of grade Ill tumours. Conclusion: This study shows that in Pakistani females, the most commonly encountered lesion in carcinoma of the breast followed by the benign lesions such as fibro adenoma, fibrocystic disease & others. Breast carcinoma occurs at a younger age group with predominance of high-grade lesions and with frequent lymph node metastasis

Genetic variability in the precore and core promoter regions of hepatitis B virus strains in Karachi

BACKGROUND: Hepatitis B virus (HBV) genotypes have distinct geographic distribution. Moreover, much genetic variability has been described in the precore (PC) and basal core promoter (BCP) regions of the HBV genome. The local prevalence of HBV genotypes and mutations has not been well studied. The aim of the present study is to determine the prevalence of HBV genotypes and mutations in the PC and BCP region in HBV strains in Karachi. METHODS: A total of 109 chronic hepatitis B patients with detectable HBV DNA by a PCR assay were enrolled in the study. Sera were tested for HBeAg, anti-HBe antibody and liver profile. HBV genotypes and mutations in the PC and BCP regions were detected by INNO-LiPA line-probe assays. RESULTS: Of the 109 patients investigated, 38 (35%) were HBeAg positive while 71 (65%) were HBeAg negative. Genotype D was present in 100% of the patients. Two patients had co-infection with genotype A. There was no significant difference in the baseline characteristics, mean ALT levels, and presence of clinical cirrhosis in patients with HBeAg positive or negative strains with or without PC and BCP mutations. Of the 38 HBeAg positive patients, 9 (24%) had PC and BCP mutations. In the HBeAg negative patient group, mutations were detected in 44 (62%) of the strains investigated. More than one mutation was common, seen in 26 (37%) patients with HBeAg negative disease and 6 (16%) patients with HBeAg positive disease. Twelve (17%) HBeAg negative patients had dual T1762 and A1764 mutations. None of the HBeAg positive patients had T1762 mutation. Mutations were undetectable in 27 (38%) of patients with HBeAg negative disease. CONCLUSION: Our study shows that type D is the main HBV genotype in Karachi, Pakistan. Significant numbers of patients infected with this genotype have PC and BCP variants. Mutations at more than one site are common. Patients harboring these mutants do not differ significantly in their clinical presentation from patients having wild type infection

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

Self-healing glass fibres with carbon nanotube-epoxy nanocomposite coating

This paper reports a study based on a novel concept of self-healing' coatings applied onto the brittle fibre surface to reduce the stress concentrations and thus to improve the reinforcing efficiency in a composite. The individual E-glass fibres as well as rovings were coated with a carbon nanotube (CNT) reinforced epoxy composite. The tensile strengths were measured for the individual and bundle fibres, which were treated statistically to determine the Weibull parameters and thus to evaluate the notch sensitivity of the fibres with and without coating. The results indicate that the tensile strength of the individual fibre increased by 10% after coating with neat epoxy. Coating with epoxy nanocomposite containing 0.3wt% MWNT further improved the tensile strength. However, increasing the nanotube content was not necessarily beneficial due to the formation of nanotube agglomerates within the matrix. The tensile tests on fibre roving also showed a clear trend of beneficial effect of nanocomposite impregnation on tensile strength. The rovings impregnated with nanocomposite exhibited a more uniform strength distribution and higher strengths than those impregnated with neat epoxy. Changes in prevailing failure mechanisms influenced by the epoxy and nanocomposite coatings are identified

Outdoor testing of photovoltaic modules during summer in Taxila, Pakistan

An experimental study has been carried out to measure the performance of commercially available photovoltaic modules during summer months in the climate of Taxila, near the capital of Pakistan. The modules used in the study are monocrystalline silicon (c-Si), polycrystalline silicon (p-Si) and single junction amorphous silicon (a-Si). The analysis has been focused on the measurement of module efficiency, performance ratio and temperature of each module at actual operating conditions using outdoor monitoring facility. The measured results are compared with the already published data of peak winter month at the same site. Overall, the monocrystalline module showed high average module efficiency while amorphous silicon module was better in term of average performance ratio. Furthermore, the module efficiency and performance ratio has shown decreasing trend with increase of module temperature. It was found that modules have much higher temperature in summer months (about 20°C higher) and showed low efficiency and performance ratio than peak winter month. The average ambient temperature varied from 18.1°C to 38.6°C from winter to summer

An experimental investigation of performance of photovoltaic modules in Pakistan

An outdoor experimental study was carried out to investigate and compare the performance of three commercially available photovoltaic modules (monocrystalline, polycrystalline and single junction amorphous silicon) under the weather of Pakistan for the month of January. Power output efficiency, module efficiency, and performance ratio are calculated for each module and comparison is presented. Results have shown that mono-crystalline and poly-crystalline modules perform better at high irradiance and show poor performance in low irradiance conditions. Amorphous solar module has shown better light absorption characteristic and performs better in low irradiance i.e. in cloudy and diffuse sunshine conditions. Monocrystalline photovoltaic module is found to be more efficient, having module efficiency of 13.5% which is higher than the other two modules. Furthermore the power output of mono-crystalline and poly-crystalline modules has shown a higher decrement at higher module temperatures compared to the amorphous solar module. Because of better performance in low solar irradiance, amorphous solar module has shown monthly average performance ratio of 1.07 which is higher than other photovoltaic modules under study