Role of oxidative stress & transient receptor potential in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) affect millions of people worldwide and is known to be one of the leading causes of death. The highly sensitive airways protect themselves from irritants by cough and sneeze which propel endogenous and exogenous substances to minimize airway noxious effects. One noxious effect of these substances is activation of peripheral sensory nerve endings of nociceptor neurons innervating these airways lining thus transmitting dangerous signals from the environment to the central nervous system (CNS). Nociceptor neurons include transient receptor potential (TRP) ion channels, especially the vanilloid and ankyrin subfamilies, TRPV1/A1 which can be activated by noxious chemical challenges in models of airways disease. As oxidative stress may activate airways sensory neurons and contribute to COPD exacerbations we sought to review the role that TRP channel activation by oxidative signals may have on airway responses. i0 t would be prudent to target the TRP channels with antagonists and lower systemic oxidative stress with agents that can modulate TRP expression and boost the endogenous levels of antioxidants for treatment and management of COPD.

CD14 C-159T polymorphism and its association with chronic lung diseases: A pilot study on isocyanate exposed population of Central India.

CONTEXT: CD14 functions as a multifunctional receptor for bacterial cell wall components including endotoxin and lipopolysaccharide and is likely to influence the cytokine profile and subsequent immunoglobulin E production in response to antigen/allergen contact in allergic phenotypes. AIMS: The present study was to investigate genetic polymorphism in CD14 gene - 159C/T, which may be one of the risk factor for increased prevalence of Chronic Lung Diseases in the Central India. SETTINGS AND DESIGN: Survivors of Methyl isocyanates toxicity in Bhopal still suffering from various respiratory ailments were examined. MATERIALS AND METHODS: Polymerase chain reaction-restriction fragment length polymorphism was performed to determine the polymorphism of C-159T. RESULTS: The genotype and allelic frequencies were in Hardy-Weinberg's equilibrium. Prevalence of CC, CT, and TT were 5.5%, 22.2% and 9.25% respectively in asthmatics; 16.6%, 20.3% and 5.5% respectively in chronic obstructive pulmonary disease (COPD) patients and 5.5%, 14.8% and 1.85 respectively among interstitial lung disorder (ILD) patients; whereas the control cohort with no methyl isocyanate exposure displayed (CC, CT, and TT) cytosine, thymine as 2%, 1.6% and 2% respectively. Increased risk of Asthma among those carrying TT genotype and T allele (odds ratio [OR] =2.61 and 2.02 respectively). CONCLUSION: COPD risk significantly found among those with CC genotype and C allele (OR = 2.81 and 1.50 respectively), whereas ILD risk found significantly among CT genotype and C allele (OR = 1.75 and 1.40 respectively). Therefore, single nucleotide polymorphism (SNP) C-159T polymorphism in CD14 gene might be a risk factor for development of CLD in this population.

Diagnosis of gastrointestinal tuberculosis: Using cytomorphological, microbiological, immunological and molecular techniques - A study from Central India.

The present study included three groups: (A) age and gender matched control (n=24) with no previous signs of M. tuberculosis complex (MTBC) infection, (B) patients (n=28) diagnosed with gastro-intestinal TB (GITB), (C) patients (n=50) with clinical and histo-pathological signs of GITB, but were culture and AFB negative. Real time assay performed using fluorescence resonance energy transfer hybridization probes showed a positivity index of 36 % in group C, i.e. 18 were found reactive from the total 50 cases studied. In addition, immune characterization of these 18 cases showed depleted CD(4) (+) count and increased levels of IFN-γ and TNF-α cytokines. No positive case was found in group A, while in group B, out of total 28 cases studied 27 were found positive. A combinatorial diagnostic approach for rapid detection and characterization of GITB might provide specific therapeutic strategies for prevention and treatment of the infection in future.

Regulation of isocyanate-induced apoptosis, oxidative stress, and inflammation in cultured human neutrophils: isocyanate-induced neutrophils apoptosis.

Implications of environmental toxins on the regulation of neutrophil function are being significantly appraised. Such effects can be varied and markedly different depending on the type and extent of chemical exposure, which results in direct damage to the immune system. Isocyanates with functional group (-NCO), are considered as highly reactive molecules with diverse industrial applications. However, patho-physiological implications resulting from their occupational and accidental exposures have not been well delineated. The present study was carried out to assess the immunotoxic response of isocyanates and their mode of action at a molecular level on cultured human neutrophils isolated from healthy human volunteers. Studies were conducted to evaluate both dose- and time-dependent (n = 3) response using N-succinimidyl N-methylcarbamate, a chemical entity that mimics the effects of methyl isocyanate in vitro. Measure of apoptosis through annexin-V-FITC/PI assay, active caspase-3, apoptotic DNA ladder assay and mitochondrial depolarization; induction of oxidative stress by CM-H(2)DCFDA and formation of 8'-hydroxy-2'-deoxyguanosine; and levels of antioxidant defense system enzyme glutathione reductase, multiplex cytometric bead array analysis to quantify the secreted cytokine levels (interleukin-8, interleukin-1beta, interleukin-6, interleukin-10, interferon-gamma, tumor necrosis factor, and interleukin-12p70) parameters were evaluated. Our results demonstrate that isocyanates induce neutrophil apoptosis via activation of mitochondrial-mediated pathway along with reactive oxygen species production; depletion in antioxidant defense states; and elevated pro-inflammatory cytokine response.

Correlation of aberrant expression of p53, Rad50, and cyclin-E proteins with microsatellite instability in gallbladder adenocarcinomas.

Gallbladder carcinoma is an uncommon, but highly malignant tumor, with poor prognostic, and diagnostic manifestations in early stages. The Indian Council of Medical Research reported increased incidence of gallbladder carcinoma in the surviving population of the Bhopal gas tragedy that involved exposure of more than 500,000 people to methyl isocyanate gas. The severity of exposure, and increased multi-systemic morbidity in the survivors stimulated us to examine the molecular changes leading to gallbladder carcinoma. Surgically resected samples (N = 40) of gallbladder carcinoma were studied for the p53, Rad50, and cyclin-E expression by immunohistofluorescence bioimaging. Among the 40 samples, 23, 11, and 10 showed p53, Rad50, and cyclin-E expression, respectively, in moderately differentiated adenocarcinomas, demonstrating the prevalence and invasiveness of this disease in the methyl isocyanate-exposed population (P = 0.0009). Nevertheless, co-expression of Rad50, and cyclin-E with p53 was absent in adenomas with dysplasia, demonstrating their independent roles. We conclude that there was altered expression of p53, Rad50, and cyclin-E in the malignant transformation of gallbladder carcinoma in this methyl isocyanate gas-exposed cohort. Hence, these proteins may be useful as markers to identify premalignant lesions that are likely to progress into malignant adenocarcinoma.

Inflammatory response to isocyanates and onset of genomic instability in cultured human lung fibroblasts.

Lungs comprise the primary organ exposed to environmental toxic chemicals, resulting in diverse respiratory ailments and other disorders, including carcinogenesis. Carcinogenesis is a multi-stage phenomenon, which involves a series of genetic alterations that begin with genomic instability provoked by certain factors such as inflammation and DNA damage and end with the development of cancer. Isocyanates such as methyl isocyanate are the chief metabolic intermediates in many industrial settings with diverse applications; exposure to them can lead to severe hypersensitive, mutagenic and genotoxic alterations. We examined the molecular mechanisms underlying isocyanate-mediated inflammatory responses and their probable role in the onset of genomic instability in cultured IMR-90 human lung fibroblasts. The isocyanates induced inflammation, resulting in extensive DNA damage, evidenced by increases in ATM, ATR, gammaH2AX, and p53 expression levels. The apoptotic index also increased. Chromosomal anomalies in treated cells included over-expression of centrosome protein and variable amplification of inter-simple sequence repeats, further demonstrating isocyanate-induced genomic instability. This information could be useful in the design of new approaches for risk assessment of potential industrial disasters.

Pitfalls of radiofrequency assisted liver resection.

BACKGROUND/AIMS: Radiofrequency has been used recently for bloodless liver resection. We studied the safety and feasibility of using RF energy for liver parenchymal transection in 8 patients. METHODOLOGY: We performed eight (n=8) open RF assisted liver resection for various malignancies. There were 5 men and 3 women, with mean age of 56.5 years (range 20-80 years). RESULTS: All patients had successful liver resection. The mean operating time for liver resection was 45 minutes (range 25-60 min). The average blood loss for wedge resections and segmentectomies was 30 mL (range 10-100 mL). None of the patients required postoperative transfusion. Three out of eight patients developed minor complications in the form of intra-abdominal abscesses which were managed by USG guided drainage of abscess in two patients and one patient had open surgical drainage of the subhepatic abscess. CONCLUSIONS: RF assisted liver resection is safe and effective with minimal blood loss for minor liver resections. Though the procedure is slightly more time consuming presently, with further improvement in technology and needles, the operative time may be reduced for this technique. RF assisted liver resection should be avoided in the presence of overt local sepsis.

Need for an individualized and aggressive management of multinodular goiters of endemic zones by specially trained surgeons: experience in western Nepal.

BACKGROUND: The goals of the present study were to explore the presentation of multinodular goiter (MNG) and solitary thyroid nodules (STN) in the sub-Himalayan belt, including the risk of malignancy, and to evaluate whether specialized surgeon training in endocrine surgery has an effect on reducing complications. METHODS: This retrospective study (1998-2003) analyzed 624 patients with thyroid disorders seen in the thyroid clinic of a tertiary care hospital in western Nepal. The findings included 67.7% (n = 423: euthyroid, 297, toxic, 126) multinodular goiters (MNG) and 18.5% (n = 116) STN. Rest of patients of other thyroid disorders were excluded from the study. Ultrasonography and fine-needle aspiration cytology (FNAC) were the available diagnostic adjuncts. To evaluate the role of surgeon training, outcomes were compared between patients cared for by surgeons specially trained in endocrine surgery and those who were not. Prognostic markers indicated aggressiveness of cancers. RESULTS: Of the 539 MNG and STN patients in this series, 236 underwent operation. Of these, 25.7% (139/539) were toxic, and 11.31% had associated carcinoma. Aggressive cancers, like poorly differentiated (4.9%) and anaplastic types (18%), were more common than in series of patients from iodine-sufficient regions. Patients 40-55 years of age were more likely to have toxicity, and those > 60 years of age were more likely to have aggressive cancers. Postoperative complication rates were lower in the group treated by surgeons who had special training in endocrine surgery. CONCLUSIONS: There is a higher incidence of toxicity and malignancy in MNG in an endemic goiter zone. The limited diagnostic and therapeutic facilities in the region under study warrant a high degree of clinical suspicion and judgment, sound knowledge of thyroid physiology, thorough interpretation of hormone test results, and meticulous surgical techniques. The treatment must be individualized with consideration of humanitarian and socioeconomic factors, without compromising the quality of care and its long-term consequences. Aggressive management of malignancy and toxicity with total thyroidectomy is needed as primary therapy in many instances. However, subtotal excision is more useful in carefully selected cases with a small remnant. Specialized training in thyroid surgery appears to be valuable in reducing complications.

HIV AND TUBERCULOSIS CO-INFECTION IN A REFERRAL CHEST HOSPITAL.

Serving personnel of Armed Forces admitted with tuberculosis between Apr 1996-1999 were evaluated for co-infection of tuberculosis and HIV. Sixty (1.06%) of tuberculosis patients were found to be HIV positive. Initial test was done by spot kits and subsequently confirmed by ELISA on two different samples. Majority of the cases were in sexually active age group 48 (80%). Alcohol and smoking was associated in 80% cases. Thirty six (60%) were sputum smear positive for AFB. Twenty eight (46.7%) gave history of exposure to sex workers. Family members were not available for study. Sero prevalence of HIV in association with tuberculosis is less in Armed Forces compared to civil population.

Congenital urethral fistula.

A 3-year-old male child was presented with the history of passage of urine coming from the undersurface of penis and its tip since birth. An opening was present on the ventral aspect of midshaft of penis through which a catheter could be passed. It was diagnosed as urethral fistula which was managed surgically.

ENDOTHELIAL CELL CULTURE AND SEEDING OF PROSTHETIC VASCULAR GRAFTS: AN EXPERIMENTAL STUDY.

Current synthetic vascular prostheses do not acquire lining of vascular endothelium in humans or dogs. Endothelial seeding of vascular grafts has been proposed as a means of reducing the thrombogenicity of these grafts. We examined feasibility of cultivating endothelial cells (EC) by tissue culture technique and their subsequent seeding onto small diameter polytetra fluoroethylene (PTFE) grafts. Twenty adult dogs underwent common carotid artery interposition with 4 mm PTFE grafts. Ten dogs received seeded and the remaining ten received unseeded grafts. Grafts were removed at 4 and 12 weeks and their gross/morphological features compared. Cumulative patency rates for seeded grafts were 70% as compared to unseeded ones 30%. Seeded grafts were completely surfaced with a mono-layer of endothelium by 4 weeks. Small graft patency appears to be related to the establishment of an endothelial surface, the development of which is clearly facilitated by seeding with autogenous endothelium.

A COMPARATIVE STUDY OF REPAIR OF INGUINAL HERNIAS BY SHOULDICE TECHNIQUE VIS-A-VIS BASSINIS TECHNIQUE.

A comparative study of repair of inguinal hernias by Shouldice technique (ST) vis-a-vis Bassinis technique (BT) was conducted on 100 patients who presented with inguinal hernia in the OPD services of our hospital. The patients were worked up and alternatively distributed to undergo repair by ST (n=50) or BT (n=50). Repair by ST required longer operating time (Avg 95 min vs 80 min), but involved lesser hospitalization (4.0 days vs 4.5 days), lesser complication rate (2 vs 4), lesser recurrence rate (0 vs 2) and higher rate of satisfaction. The study confirms the advantages of Shouldice repair in the treatment of inguinal hernia.