Effect of chloride on the dissolution rate of silver nanoparticles and toxicity to E. coli.

Pristine silver nanoparticles (AgNPs) are not chemically stable in the environment and react strongly with inorganic ligands such as sulfide and chloride once the silver is oxidized. Understanding the environmental transformations of AgNPs in the presence of specific inorganic ligands is crucial to determining their fate and toxicity in the environment. Chloride (Cl(-)) is a ubiquitous ligand with a strong affinity for oxidized silver and is often present in natural waters and in bacterial growth media. Though chloride can strongly affect toxicity results for AgNPs, their interaction is rarely considered and is challenging to study because of the numerous soluble and solid Ag-Cl species that can form depending on the Cl/Ag ratio. Consequently, little is known about the stability and dissolution kinetics of AgNPs in the presence of chloride ions. Our study focuses on the dissolution behavior of AgNPs in chloride-containing systems and also investigates the effect of chloride on the growth inhibition of E.coli (ATCC strain 33876) caused by Ag toxicity. Our results suggest that the kinetics of dissolution are strongly dependent on the Cl/Ag ratio and can be interpreted using the thermodynamically expected speciation of Ag in the presence of chloride. We also show that the toxicity of AgNPs to E.coli at various Cl(-) concentrations is governed by the amount of dissolved AgCl(x)((x-1)-) species suggesting an ion effect rather than a nanoparticle effect.

Pattern of autologous stem cell transplants at a tertiary care government hospital, with emphasis on transplant outcomes with pre-harvest CD34+ level.

Purpose: Autologous stem cell transplantation (ASCT) is an established therapy for many hematological diseases. This study assessed the pattern of ASCTs at a tertiary care center and associated factors, including pre-harvest CD34+ stem cell levels, leading to improved engraftment outcomes. Methodology: A retrospective study was conducted in India, between February 2009-August 2020. Patients who underwent ASCT for different hematological malignancies (n=65) were included, and the patients' age, sex, type and stage of disease, pre- and post-harvest CD34+ counts, and time to attain platelet/neutrophil engraftment or febrile neutropenia were analyzed. The post-harvest CD34+ dose was calculated. Pre-conditioning was performed using Granulocyte Colony Stimulating Factor (GCSF)±Plerixafor. Progression-free survival (PFS) was calculated using relapse/death as the endpoint. Results: The median age of the cohort (n=65) was 49 years, with a male preponderance. Multiple myeloma was the most common malignancy (70.8% [46/65]), requiring ASCT. The median time to ASCT was 13 months. All patients had received GCSF, while Plerixafor was used in 17 patients with a pre-harvest CD34+ count of <10 cells/µL. The median pre-harvest CD34+ concentration and post-harvest CD34+ cell dose was 27.54 cells/µL (n=26) and 5.23×106 cells/kg body weight (n=65), respectively. The median time to engraftment was 11 and 12 days, for neutrophils and platelets, respectively. One patient did not engraft and was excluded from the analysis. The time required to attain neutrophil engraftment was significantly lower (p=0.02) among freshly harvested stem cells (n=48) than that of cryopreserved products (n=17). Platelet engraftment associated with CD34+ pre- and post-harvest levels was not significant (p=0.06). The time to attain neutropenia and subsequent febrile neutropenia was significantly lower with an adequate post-harvest CD34+ dose (p=0.009). Febrile neutropenia was seen in 83.1% (54/65) patients. The median time for febrile neutropenia was 4 days post-ASCT. Pre- and post-harvest CD34+ concentrations were directly proportional to each other (p<0.001). The median PFS was 112 months (n=65). Survival was better in males (median PFS: 112 months) vs. females (median PFS: 59 months) (p=0.27). Eight patients relapsed, and eight patients had died. Conclusion: Although unrelated to age or sex, the post-harvest CD34+ dose was inversely related to febrile neutropenia. As pre- and post-harvest CD34+ levels were directly proportional, pre-harvest CD34+ concentrations may be reliably used to assess engraftment outcomes. Rapid neutrophil engraftment was noted in fresh stem cells with PFS of 112 months, and was better among males, the exact reason being unknown. Thus, a larger number of patients should be followed up to obtain an accurate picture.

Spectrum of Hemoglobinopathies in West Bengal, India: A CE-HPLC Study on 10407 Subjects.

Hemoglobinopathies are common genetic disorders of haemoglobin. Identification of these disorders is immensely important epidemiologically and they can be prevented by population screening. The present study was carried out to evaluate the spectrum of hemoglobinopathies in the state of West Bengal by the cation-exchange high-performance liquid chromatography (CE-HPLC). A retrospective, single-center, cross-sectional study was conducted on consecutive 10,407 participants. Out of 10,407 subjects, 8,898 (85.5 %) were diagnosed as normal, 579 (5.6 %) were as ß-thalassemia trait (BTT) and 522 (5.0 %) were detected as HbE carrier on HPLC study. Apart from BTT and HbE carrier ten additional variants were encountered. The present study showed that CE-HPLC is a convenient, high-throughput, labour-saving and objective screening tool for early detection and management of hemoglobinopathies.

Expression of CDX-2 and Ki-67 in different grades of colorectal adenocarcinomas.

BACKGROUND: CDX2 is a caudal homeobox gene essential for intestinal differentiation and is specifically expressed in colorectal adenocarcinomas. Its role in colorectal carcinogenesis is not fully elucidated. AIMS AND OBJECTIVES: To study the expression pattern of CDX2 and Ki-67 in different grades of colorectal adenocarcinomas and to observe the relationship of their staining patterns in various tumor stages and to look for correlation if any, between Ki-67 labeling index (Ki-67 LI) and CDX2 expression. MATERIALS AND METHODS: A total of 74 cases were enrolled. Detailed clinical profile, peroperative findings, histological grading and staging were noted. Immunohistochemistry for CDX2 and Ki-67 was done, and Ki-67 LI was calculated. CDX2 staining was graded semi-quantitatively, and statistical analysis was done. RESULT: Age of presentation ranged from 20 to 75 years, and the male:female ratio was 1.83:1. There were 8, 47 and 13 cases of well, moderate and poorly differentiated adenocarcinomas, respectively. The mean Ki-67 LI of well, moderate and poorly differentiated adenocarcinomas were 14.25, 31.34 and 43.08 respectively, and their difference was statistically significant, correlation was also noted with stage. CDX2 expression appeared to be stronger in poorly differentiated cases, but there was no significant difference in its expression in the different grades and stages. There was no correlation between Ki-67 LI and CDX2 immunostaining pattern. The lymph node metastasis showed CDX2 positivity in all the cases. CONCLUSION: Expression of CDX2 does not significantly change with the grade of colorectal adenocarcinomas. However, it is an important diagnostic marker in metastatic colonic lesions. The Ki-67 LI, on the other hand, showed a strong correlation with histopathological grades.

Amoeboma of colon mimicking colonic carcinoma.

Entamoeba histolytica is a major cause of diarrhea in the developing countries and it can present with a wide range of gastrointestinal symptoms depending on the phase of the infection. We describe a case of 65-year-old male patient presented with abdominal pain and vomiting. On the clinical and radiological examination provisional diagnosis of colonic carcinoma was suspected. After resection of perforated caecal growth, histopathological sections showed numerous trophozoites of E. histolytica in a background of abundant necrosis. This case revealed differentiation between amoeboma and carcinoma is critical.

Analysis of FNAC of cervical lymph nodes: experience over a three-year period.

This study was taken up with the aim to investigate the pattern of cervical lymphadenopathy among patients presenting to IPGME&R, Kolkata, a tertiary care institution in Eastern India to evaluate the diagnostic efficacy of FNAC, and to dissect the diagnostic pitfalls. A total of 509 patients were subjected FNAC of cervical lymph nodes over a three-year period (August 2006-July, 2009). Since in 34 patients, as either the aspirate was inadequate or the opinion equivocal, the remaining 475 cases were analysed. Overall tuberculous lymphadenitis was the most common finding (222/475; 46.7%), while reactive hyperplasia was the commonest presentation (45%) in patients less than 20 years of age. Malignant pathology accounted for 13.7% (65/475) of cervical lymph node enlargement, most of which was due to metastatic squamous cell carcinoma (44/65; 67.7%). Histopathology reports were available for comparison in 220 cases. Twelve cases of tuberculosis were missed in FNAC and were reported as either reactive hyperplasia (n = 9) or acute non-specific lymphadenitis (n = 3). Among the 3 cases of metastatic squamous cell carcinoma that were missed in FNAC, one was reported as tuberculous lymphadenitis (due to granuloma formation) and the other 2 as reactive hyperplasia due to sampling error. FNAC is an excellent first line of investigation and when used with a proper combination of experience and diligence, it can greatly reduce the number of errors.

Morphometric and histological study of breast lesions with special reference to proliferative activity and invasiveness.

Breast carcinoma is the most common cause of carcinoma death in women. Sometimes, difficulty arises to differentiate between premalignant lesions and carcinoma by routine histopathology. Our study was done to establish the role of morphometry and immunohistochemistry to solve this problem. In this study, total 60 cases of different breast lesions were included and 10 controls were also included to compare the results with the normal findings. They were studied by hematoxylin and eosin-stained sections for morphometry and routine histological study; as well as by proliferative markers such as proliferating cell nuclear antigen and p53. Invasiveness was studied using immunohistochemical staining with 34 ßE12 monoclonal antibody. Statistically significant differences were found in morphometric parameters and in expression of proliferative markers between most of them. Morphometry and immunohistochemistry help in the proper diagnosis of different breast lesions that lie in the gray zone on routine histopathology.

Fine needle aspiration cytology of supraclavicular lymph nodes: Our experience over a three-year period.

AIMS: This study was taken up with the aim to investigate the pattern of supraclavicular lymphadenopathy among patients presenting to our tertiary care institution, evaluate the diagnostic efficacy of fine needle aspiration cytology (FNAC), and analyze the diagnostic pitfalls. MATERIALS AND METHODS: A total of 215 patients were subjected to FNAC of supraclavicular lymph nodes over a three-year period (August 2006 to July 2009). Since in 18 patients as either the aspirate was inadequate or the opinion was equivocal, we analyzed the remaining 197 cases. RESULTS: Malignant pathology accounted for 79.7% (157/197) of the cases. These were mostly cases of metastatic squamous cell carcinoma (79/197, 40.1%), adenocarcinoma (47/197, 23.9%), small cell carcinoma (12/197, 6.1%) and lymphoma (10/197, 5%). There were 28 (14.2%) cases of tuberculosis. Out of these 197 patients, 92 patients were biopsied. The opinion based on FNAC was erroneous in 6 cases but corroborated with the final histopathology findings in the remaining 86 cases. CONCLUSION: FNAC is an excellent first line of investigation; and when used with a proper combination of experience and diligence, it can greatly reduce the number of errors.

Paraganglioma of the oropharynx.

Paraganglioma is a rare tumor in head and neck region. A 35 years male presented with huge swelling of tonsillar region occupying a large portion of oropharynx. Tumor had been dissected out transorally. HPE showed extra-adrenal paraganglioma. It is being reported because of its rare clinical presentation and unusual surgical approach.

Squash preparation: A reliable diagnostic tool in the intraoperative diagnosis of central nervous system tumors.

BACKGROUND: Intraoperative cytology is an important diagnostic modality improving on the accuracy of the frozen sections. It has shown to play an important role especially in the intraoperative diagnosis of central nervous system tumors. AIM: To study the diagnostic accuracy of squash preparation and frozen section (FS) in the intraoperative diagnosis of central nervous system (CNS) tumors. MATERIALS AND METHODS: This prospective study of 114 patients with CNS tumors was conducted over a period of 18 months (September 2004 to February 2006). The cytological preparations were stained by the quick Papanicolaou method. The squash interpretation and FS diagnosis were later compared with the paraffin section diagnosis. RESULTS: Of the 114 patients, cytological diagnosis was offered in 96 cases. Eighteen nonneoplastic or noncontributory cases were excluded. Using hematoxylin and eosin-stained histopathology sections as the gold standard, the diagnostic accuracy of cytology was 88.5% (85/96) and the accuracy on FS diagnosis was 90.6% (87/96). Among these cases, gliomas formed the largest category of tumors (55.2%). The cytological accuracy in this group was 84.9% (45/53) and the comparative FS figure was 86.8% (46/53). In cases where the smear and the FS diagnosis did not match, the latter opinion was offered. CONCLUSIONS: Squash preparation is a reliable, rapid and easy method and can be used as a complement to FS in the intraoperative diagnosis of CNS tumors.