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Biomedical subjects

M Choudhury

Publications and source records attributed to M Choudhury.

At least 19 recordsLinked to original sources
PubMed2006

Preoperative ultrasound-guided fine-needle aspiration cytology for axillary staging in breast carcinoma.

Axillary lymph node (ALN) status is considered to be the single most important prognostic indicator in patients with breast cancer. It can be assessed by various radiological, pathological and surgical techniques, the most accurate being histological examination of lymph nodes after axillary lymph node dissection (ALND). This prospective study was conducted to assess the feasibility and diagnostic accuracy of preoperative ultrasound (US) and ultrasound-guided fine-needle aspiration cytology (USG-FNAC) of ALN in patients with breast cancer. Thirty patients with FNAC-proven breast cancer, planned for definitive surgery with axillary clearance, were included in this study. Ultrasonographic evaluation of the axillae of these patients was conducted for alterations in size, shape, contour and cortical morphology of lymph nodes that could reflect presence of underlying metastases. Ultrasound-guided fine-needle aspiration cytology of the ALN was done in 24 of these patients. These findings were evaluated, with the ALN status determined by histological examination after ALND. Out of the 30 patients, eight had T(1), 16 had T(2), five had T(3), and one had T(4) lesions. Ultrasound evaluation of the ALN had a sensitivity of 86.3%, a specificity of 41.6%, a positive predictive value of 79%, a negative predictive value of 50% and a diagnostic accuracy of 73.3%. Sensitivity of USG-FNAC was 78.95%, specificity was 100%, positive predictive value was 100%, negative predictive value was 55.56% and diagnostic accuracy was 83.33%. Our study concludes that preoperative USG-FNAC of ALN is a simple, minimally invasive, easily available and reliable technique for the initial determination of ALN status in patients with breast cancer. Those who are USG-FNAC positive can be directed towards ALND straight away, and only those who are USG-FNAC negative should be considered for sentinel lymph node biopsy. This will save considerable operating time, especially where facilities for sentinel lymph node biopsy (costly dye, gamma camera, nuclear medicine facilities) are restricted or not available.

Axilla↗
PubMed2003

Pancreatic fistulae--rare complication of cholecystectomy.

Pancreaticocutaneous fistula after cholecystetactimy is a very rare condition. A 40 year male patient presented with a drain tube on the right lateral abdominal wall with drainage of 200 ml turbid fluid daily for about 2 months following cholecystectomy. After through investigation and operation it was diagnosed as external pancreatic fistula. It is treat by fistulojejunal anastomosis with Roux-En-Y loop of Jejurum in Bangabandhu Sheikh Mujib Medical University Hospital, Dhaka.

Adult↗
PubMed2002

Total intravenous anaesthesia for tracheobronchial stenting in children.

Stenosis and malacia of the tracheobronchial tree, most often secondary to prolonged intubation, tracheostomy or following correction of a congenital cardiac lesion, present a significant therapeutic problem, especially when the lesions are extensive. The utilization of self-expanding tracheobronchial stents is a useful addition to the medical armamentarium for maintenance of airways in these patients with major airway stenosis and collapse. The majority of previous reported cases of tracheobronchial stenting have been performed under general anaesthesia with the help of rigid bronchoscopy under direct vision. We conducted two cases of tracheobronchial stenting in postoperative cardiosurgical babies under continuous propofol infusion taking advantage of cardiovascular stability during continuous infusion and rapid emergence after its discontinuation.

Airway Obstruction↗
PubMed2001

Systemic and local antimicrobial use in periodontal therapy in England and Wales.

BACKGROUND/AIMS: The aim of this study was to investigate antimicrobial use during periodontal therapy in dental practice in England & Wales. METHOD: This was a postal questionnaire survey of 800 dentists, 400 general dental practitioners (GDP) in National Health Service practice and 400 members of the British Society of Periodontology (Periodontal Society) primarily in dental practice. We designed and piloted a questionnaire to evaluate both systemic and local antibiotic use with periodontal therapy as well as factors affecting their prescription. In addition, we also investigated the potential use of antibiotic sensitivity testing, since this has been recommended prior to prescribing antibiotics. Two follow-up mailings were used to encourage non-responders. RESULTS: The useable return rate for the questionnaires was 587/800 (73%). Systemic antibiotics were used by 7.4% Periodontal Society members and 18.4% GDP for untreated adult periodontitis patients (p<0.001). Antimicrobials were prescribed more frequently by Periodontal Society members in early onset (52.7%) and refractory periodontitis patients (49.6%), and this was highly statistically significantly greater usage than GDP (p<0.001). Regarding local antimicrobials, usage for untreated adult periodontitis was Periodontal Society 8.9% and GDP 5.4%. Higher usage of local antimicrobials was found both for the treatment of recurrent pocketing in adult periodontitis (Periodontal Society 26.3%, GDP 14.8%, p<0.014) and refractory periodontitis (Periodontal Society 30.8%, GDP 15.2%, p<0.001). As reasons for using local antimicrobials, more than 80% of all respondents stated superiority over root debridement alone. Barriers to use included cost, no perceived need and lack of supporting research data. The percentage of responders considering diagnostic microbiology either theoretically or at a cost of pound 60 were by group, Periodontal Society 83% & 70.4% and GDP 76% & 51.2%. 33% of Periodontal Society members and 3.8% of GDP spent at least 45 min per quadrant on root planing and Periodontal Society members had a greater exposure to lectures on both systemic and local drug therapy compared with GDP (p<0.001). CONCLUSIONS: Systemic antimicrobial use was infrequent for adult periodontitis and generally in line with current recommendations for other disease types. Whilst local antimicrobial therapy for periodontitis was not widespread, a substantial minority of dentists use this form of therapy and most believe that it is more effective than root debridement alone.

Adult↗
PubMed2001

Lactating adenoma--cytomorphologic study with review of literature.

Lactating adenoma is an uncommon well-differentiated benign tumor of secretory mammary epithelium that occurs in pregnant and lactating women. Three percent of all breast cancers are diagnosed during pregnancy and need to be differentiated from other breast masses occurring in pregnancy and lactational states. Its origin, though controversial, is believed to be de novo or a variant of pre-existing tubular adenoma or fibroadenoma, that reflects the morphologic changes resulting from the physiologic state of pregnancy. Four pregnant/lactating women presenting with solitary breast masses were aspirated. Spontaneous regression of the mass was observed in two of the four cases, one underwent excision biopsy and one case was lost to follow up. All four cases were diagnosed as lactating adenoma on fine needle aspiration cytology. Cytomorphologic features included cellular aspirates comprising of epithelial cells, scattered and in small groups. The acinar cells had foamy to vacuolated cytoplasm. The nucleus had prominent nucleoli. Background showed abundant foamy material. Biopsy confirmed lactating adenoma in one of the cases. Lactating adenoma needs to be differentiated from other breast masses, including carcinoma, in pregnant or lactating women. Sonographic studies are not diagnostic and surgical biopsies are not recommended as a majority of the lesions are known to regress spontaneously.

Adenoma↗
PubMed2000

ClC-2 contributes to native chloride secretion by a human intestinal cell line, Caco-2.

It has been previously determined that ClC-2, a member of the ClC chloride channel superfamily, is expressed in certain epithelial tissues. These findings fueled speculation that ClC-2 can compensate for impaired chloride transport in epithelial tissues affected by cystic fibrosis and lacking the cystic fibrosis transmembrane conductance regulator. However, direct evidence linking ClC-2 channel expression to epithelial chloride secretion was lacking. In the present studies, we show that ClC-2 transcripts and protein are present endogenously in the Caco-2 cell line, a cell line that models the human small intestine. Using an antisense strategy we show that ClC-2 contributes to native chloride currents in Caco-2 cells measured by patch clamp electrophysiology. Antisense ClC-2-transfected monolayers of Caco-2 cells exhibited less chloride secretion (monitored as iodide efflux) than did mock transfected monolayers, providing the first direct molecular evidence that ClC-2 can contribute to chloride secretion by the human intestinal epithelium. Further, examination of ClC-2 localization by confocal microscopy revealed that ClC-2 contributes to secretion from a unique location in this epithelium, from the apical aspect of the tight junction complex. Hence, these studies provide the necessary rationale for considering ClC-2 as a possible therapeutic target for diseases affecting intestinal chloride secretion such as cystic fibrosis.

Caco-2 Cells↗
PubMed2000

Primary diagnosis of ameloblastoma by fine-needle aspiration: a report of two cases.

Ameloblastoma is the most common epithelial odontogenic tumor, comprising 1% of tumors and cysts arising in the jaws. We describe two cases of ameloblastoma of the jaw diagnosed by fine-needle aspiration cytology. The patients presented with swelling in the parotid region. Cytological examination of the particulate and sticky bloodstained fluid obtained on aspiration showed tightly packed groups of basaloid cells arranged in nests with rounded edges. Palisading epithelial cells and squamous cells with spherical keratinized bodies were the distinctive cytological features. Histologic examination confirmed the presence of ameloblastoma.

Adult↗
PubMed2000

Sevoflurane as a sole anaesthetic for thymectomy in myasthenia gravis.

Myasthenia gravis is a challenging situation for anaesthesiologists due to its neuromuscular involvement. The main concerns are respiratory muscle weakness and side effects due to a heavy dose of anticholinesterases. This limits the use of sedatives, hypnotics and muscle relaxants. Inhalational anaesthetics are best suited. We describe our experience with sevoflurane as a sole anaesthetic in a child having juvenile-type myasthenia gravis with thymoma, who underwent thymectomy by midsternal incision. Very smooth and short duration of induction (35 s) and easy intubation within 60 s without use of muscle relaxant were the remarkable features. Sevoflurane in oxygen and nitrous oxide (MAC=0.5-0.7) was used for maintenance of anaesthesia. Recovery was smooth and fast with no residual respiratory insufficiency. Hence we found sevoflurane to be a highly suitable agent for thymectomy in mysthenia gravis.

Anesthetics, Inhalation↗
PubMed1998

Stabilization of slow troponin C polypeptide compensates for its reduced synthesis in antisense oligodeoxynucleotide-treated cells.

The expression of genes for contractile proteins during myogenesis is coordinately regulated. Uncoupling the expression of the slow/cardiac troponin C (sTnC) gene from this process with an antisense phosphorothioate oligodeoxynucleotide (ODN) was used to examine the presence of any post-transcriptional mechanisms for regulating muscle protein synthesis. Approximately 70 and 50% decreases in sTnC polypeptide synthesis and mRNA levels, respectively, were achieved after 4 days antisense treatment. This decrease in sTnC polypeptide synthesis was not reflected in a similar decline in the steady-state level of this polypeptide. Extension of the ODN treatment to 7 days was required to produce a substantial decrease in the steady-state level of sTnC polypeptide. Our investigation suggests that during the 4-day treatment, the affected cells stabilized the sTnC polypeptide level by increasing its half-life. However, the stabilizing effect appears to be overridden during prolonged (7 days) antisense ODN treatment. Measurement of the polypeptide synthesis and mRNA levels of several contractile proteins showed no evidence of cross-regulation among the genes to coordinately regulate their expression levels.

Animals↗
PubMed1998

Malignant renal tumor with extension to the inferior vena cava.

BACKGROUND: Management of malignant renal tumors involving the inferior vena cava (IVC) depends on tumor extension within the cava. METHODS: Of 295 patients treated for renal cancer, propagation of tumor mass through the renal vein to IVC was seen in 22 (7%) patients. Cephalad extension of the tumor was suprarenal: infrahepatic in 12, retrohepatic in 6, and within the right atrium in 4 patients. All patients had radical nephrectomy, cavotomy, and complete resection of tumors except 1 with diffuse peritoneal metastasis. RESULTS: Twenty-one patients had curative resections. No operative deaths and no instances of pulmonary embolism or exsanguination occurred. Seventeen patients were alive at 2 years and 12 at 5 years, resulting in 77% and 55% survival rates, respectively. CONCLUSIONS: An aggressive approach for vena cava involvement from malignant renal neoplasms resulted in prevention of tumor embolus, minimization of blood loss, and maintenance of venous return to the heart.

Adolescent↗
PubMed1998

Uncoordinated inhibition of gene expression for muscle proteins by a troponin T antisense oligodeoxynucleotide.

The effect of antisense oligodeoxynucleotide to rat troponin T (TnT) mRNA on its expression in differentiated rat L6 myotubes in culture was examined. The target sequence following the initiation codon was between nucleotides 83 and 97 and is found in all mRNAs produced from the f-TNT gene. Our studies showed that chimeric oligomer with one phosphorothioate linkage at the 3'-end was considerably more resistant to nucleases than was a phosphodiester oligomer. The chimeric oligomer produced >50% inhibition of TnT polypeptide synthesis. Synthesis of myosin heavy chain (MHC), troponin I (TnI), and alpha and beta tropomyosins (Tm) was not inhibited by the anti-TnT oligomer. However, synthesis of alpha-actin and troponin C (TnC) was somewhat affected by this treatment. Furthermore, compared with the untreated control myotubes, the steady-state level of TnT mRNA was reduced by approximately 40%-50% in anti-TnT oligomer-treated myotubes. Cellular levels of three other muscle mRNAs, alpha-Tm, s-TnI, and alpha-actin were also reduced by approximately 30%-40%. In contrast, fast TnI, beta-Tm, and TnC mRNA levels were not significantly affected by this treatment. Therefore, inhibition of TnT synthesis in differentiated myotubes uncoupled the coordinated expression of muscle proteins.

Animals↗
PubMed1997

Inhibition of troponin C production without affecting other muscle protein synthesis by the antisense oligodeoxynucleotide.

The effect of blocking expression of a specific gene with antisense phosphodiester oligodeoxynucleotides on the coordinate regulation of myogenesis was studied. Different regions of both fast and slow troponin C (TnC) mRNAs were targeted for binding of the antisense oligomer. The 5'-cap region of both mRNAs was found to be the most effective target for inhibiting the expression of these genes. Approximately 40%-60% inhibition of expression of a specific isoform of TnC was achieved. However, inhibition of the TnC expression did not appreciably alter the pattern of myogenesis of mouse C2C12 cells. The differentiated murine muscle cells were able to cope with this reduced level of the target gene expression by antisense phosphodiester oligomers. We have also used a phosphorothioate oligomer targeted against a common sequence within the coding region of both fast and slow TnC mRNAs. This oligomer was found to be ineffective in blocking TnC gene expression.

Animals↗
PubMed1997

Overexpression of the heme oxygenase gene in renal cell carcinoma.

Heme oxygenase (HO) activity has been implicated in the regulation of renal function and cell growth in normal and disease states. Expression of HO genes has been shown to regulate important hemoprotein(s) such as cytochrome P450. In the present study, HO activity was measured in samples of human adenocarcinoma, juxtatumor, and normal renal tissues. The samples were histologically examined to verify the malignant and normal nature. HO activity was 4-fold higher in the adenocarcinoma than in either normal or juxtatumor tissues. We designed a reverse transcriptase-polymerase chain reaction (RT-PCR) method to assess the presence of HO-1 and HO-2 mRNA in biopsy samples of various human renal tissues. Total RNA from renal samples was reverse transcribed and amplified simultaneously by PCR using specific primers for HO-1 and HO-2. Results show that both HO-1 and HO-2 mRNAs were expressed in all renal tissues examined and that HO-1 appeared to be amplified more than HO-2. Northern blot analysis revealed that HO-1 mRNA was elevated by several-fold in adenocarcinoma compared with juxtatumor or normal tissues. In contrast, no differences in HO-2 mRNA levels were observed using either RT-PCR or Northern blot. Cytochrome P450 arachidonic acid epoxygenase and omega-hydroxylase activities were markedly reduced in the tumor tissues, whereas, in the juxtatumor tissue, cytochrome P450 omega-hydroxylase activity was significantly increased. Northern blot analysis using cytochrome P450 cDNA probe 4A2 cDNA for the omega-hydroxylase gene family revealed that mRNA levels for omega-hydroxylase transcripts were significantly decreased in the adenocarcinoma compared with juxtatumor. The decrease in cytochrome P450 4All mRNA levels correlated with a decrease in the arachidonic acid omega-hydroxylation metabolite, 20-HETE. The production of 20-HETE was significantly higher in juxtatumor in agreement with omega-hydroxylase mRNA. Higher levels of HO-1 may be a contributing factor for the undetectable levels of cytochrome P450 arachidonic acid metabolites, 20-HETE, in the adenocarcinoma. Our results suggest that increased generation of mitogenic activities by omega-hydroxylase and 20-HETE in the juxtatumor may be a contributing factor in the development and growth of neoplastic tissues, and the induction of HO in the tumor tissue may be an attempt to limit oxidative injury caused by the cytochrome P450 metabolites and other oxidative stress.

Blotting, Northern↗