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.

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.

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.

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.

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.

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.

Mesenteric cyst--an unusual presentation.

Mesenteric and retroperitoneal cysts develop from ectopic lymphatic tissue. Most of them present as symptomless abdominal swellings or are found coincidentally during abdominal operations. One third of patients may present with acute abdominal pain, and few may present with chronic abdominal pain. However, mesenteric cyst presenting as inguinal hernia is extremely rare. Only four cases have been reported in the English-language literature. The present case is the fifth, and only the second from this subcontinent. The treatment of choice is complete surgical excision.

TOTAL PARENTERAL NUTRITION.

Total parenteral nutrition has been used in clinical practice for over a quarter of a century. It has revolutionized the management of potentially fatal condition like the short bowel syndrome in infants as well as adults. Refinements in techniques have led to development of sophisticated catheters and delivery systems. Better understanding of human nutrition and metabolic processes has lead to formulation of scientific parenteral solutions to suit specific situations. This article addresses the role of total parenteral nutrition in modern surgical practice.

EMERGENCY TREATMENT OF OBSTRUCTING LARGE BOWEL CANCER.

Thirty cases of obstructing large bowel cancer were treated by emergency procedures like proximal colostomy (55%), caecostomy (3%), appendicostomy (2%), ileotransverse colostomy (6%), right hemicolectomy (14%), anterior resection (14%), Hartmann's procedure (3%) and Lahey's procedure (3%). Primary resection for tumours of the right colon and staged procedures for tumours of the left colon and rectum and are safe procedures in the management of obstructing large bowel cancer.

PARADUODENAL HERNIA (A Case Report).

A case of right paraduodenal hernia is reported. Embryogenesis and treatment of this rare type of internal hernia is discussed.

PREVENTION OF POST-OPERATIVE WOUND INFECTION IN ABDOMINAL OPERATIONS.

One hundred patients undergoing abdominal surgery were included in this prospective study. The role of local application of Betadine, use of synthetic sutures, and use of low pressure subcutaneous suction drainage were evaluated in preventing post-operative wound infection. The infection rate was 15 per cent with Betadine, 15.4 per cent with prolene, 20 per cent with subcutaneous suction drainage and 30.8 per cent in the control group.

CHOLECYSTECTOMY : FUNDUS TO PORTA APPROACH.

Cholecystectomy is a commonly performed operation but there is still controversy whether dissection of the gall bladder should proceed from the fundus to the cystic duct or in the opposite direction. In usual practice the fundus-first method is adopted whenever difficulty is encountered in visualizing the anatomy of the cystic duct and Calot's triangle. Although haemorrhage is a little greater than with the duct-first method the risk of damage to the common bile duct or right hepatic artery is minimized. This article describes a brief experience with thirty randomized patients in whom cholecystectomies were performed with planned fundus-first approach.

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.

UNDESCENDED TESTIS: A STUDY OF 50 CASES.

Fifty consecutive cases of undescended testis treated at a service hospital over a period of 3 years from January 1993 to December 1995 were studied. Only 2 patients (4%) were below the age of 2 years and 25 (50%) were past the age of 15 years. Two cases presented with seminoma in intraobdominal testis. Ultrasonography was found unreliable in localizing the impalpable testis. Subdartos pouch orchiopexy (Winsburry-White) was the definitive procedure adopted in 21 out of the 25 orchiopexies performed and the results were good. Orchidectomy seems the best option of treatment in post-pubertal patients with unilateral symptomatic maldescent.

SUPRACLAVICULAR FIRST RIB RESECTION FOR TREATMENT OF THORACIC OUTLET SYNDROME.

Twelve patients with thoracic syndrome were operated during a 15 month period. Eleven patients had features of neurogenic thoracic outlet syndrome, while one presented with arterial ischemia due to distal embolism. The diagnosis was based on the characteristic history and positive stress tests. Cervical rib was present in 7 patients. Abnormal nerve conduction studies were present in 7 out of 8 cases. Supraclavicular first rib resection was done in all patients in view of the severity of symptoms. If present, the cervical rib was also excised. There was no major operative complication. Eleven out of twelve patients reported relief of symptoms. Thoracic outlet syndrome is not an uncommon disorder and often goes undiagnosed. Resection of first rib via the supraclavicular approach gives good results in majority of the patients who have incapacitating symptoms.

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.

REVASCULARIZATION OF THE ISCHEMIC UPPER LIMB.

Eighteen cases of upper limb ischemia were operated during a 24 month period. Eleven patients presented with features of chronic ischemia, while 7 had acute ischemia with a threatened limb. There were 15 males and 3 females. The average age was 38 years. Associated medical problems were present in 8 patients. Limb perfusion was restored in all patients after direct arterial (bypass) surgery, intra-arterial thrombolysis or percutaneous transluminal angioplasty (PTA). There was no mortality. The limb salvage rate was 100 per cent. Follow-up of upto 24 months reveals a patent bypass in all patients with no recurrence of symptoms. Upper limb ischemia is not uncommon, and can be treated by thrombolysis, angioplasty or bypass surgery. Direct arterial surgery for upper limb revascularization, though technically demanding, is safe and results in relief of symptoms in the vast majority of patients.

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.