Burden of Anxiety, Depression and Perceived Stress in Patients with Inflammatory Bowel Disease: A Cohort Study from North India.

BACKGROUND: Patients with Inflammatory bowel disease (IBD) are susceptible to psychiatric co-morbidities. We aimed to ascertain the burden of anxiety, depression, and perceived stress in patients with IBD from north India. METHODS: Consenting adult patients with an established diagnosis of IBD were enrolled. The enrolled patients filled the Hospital Anxiety and Depression Scale (HADS) and Perceived Stress Scale (PSS) questionnaires. The patient and disease characteristics were analyzed to determine the correlations and predictors of psychiatric comorbidities. RESULTS: A total of 318 patients (255 UC, 63 CD; mean age 40.13 ± 12.06 years, 168 [52.8%] males; mean partial Mayo score 2.10 ± 2.35; and mean HBI 2.77 ± 2.13) were enrolled. The prevalence of anxiety, depression and moderate to high perceived stress was 14%, 12%, and 41%, respectively. Females had higher mean perceived stress, anxiety and depression scores compared to males. The partial Mayo score (PMS) correlated poorly with anxiety (ρ = 0.083, p = 0.187), depression (ρ = 0.123, p = 0.49) and perceived stress (ρ = 0.169; p = 0.007). The Harvey Bradshaw index (HBI) correlated fairly with anxiety (ρ = 0.336, p = 0.007) and poorly with depression (ρ = 0.287, p = 0.022) and perceived stress (ρ = 0.20; p = 0.117). Younger age (OR 0.93, 95% CI 0.90-0.97; p = 0.001) and hand-grip strength (OR 4.63, 95% CI 1.88-11.42; p = 0.001) predicted anxiety in patients with UC while rural area of residence (OR 4.75, 95% CI 1.03-21.98; p = 0.046) and HBI (OR 1.60, 95% CI 1.12-2.29; p = 0.009) were significant predictors of anxiety in patients with CD. CONCLUSION: Psychiatric comorbidities are common in patients with IBD, with higher prevalence in females. Young adults with UC and sarcopenia; and individuals with active CD living in rural areas are at an increased risk of anxiety.

Low prevalence of primary sclerosing cholangitis in patients with inflammatory bowel disease in India.

BACKGROUND/AIMS: Primary sclerosing cholangitis (PSC) represents the most common hepatobiliary extraintestinal manifestation of inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD). Limited data exist on PSC in patients with IBD from India. We aimed to assess the prevalence and disease spectrum of PSC in Indian patients with IBD. METHODS: Database of IBD patients at 5 tertiary care IBD centers in India were analyzed retrospectively. Data were extracted and the prevalence of PSC-IBD was calculated. RESULTS: Forty-eight patients out of 12,216 patients with IBD (9,231 UC, 2,939 CD, and 46 IBD unclassified) were identified to have PSC, resulting in a prevalence of 0.39%. The UC to CD ratio was 7:1. Male sex and pancolitis (UC) or colonic CD were more commonly associated with PSC-IBD. The diagnosis of IBD preceded the diagnosis of PSC in most of the patients. Majority of the patients were symptomatic for liver disease at diagnosis. Eight patients (16.66%) developed cirrhosis, 5 patients (10.41%), all UC, developed malignancies (3 colorectal cancer [6.25%] and 2 cholangiocarcinoma [4.16%]), and 3 patients died (2 decompensated liver disease [4.16%] and 1 cholangiocarcinoma [2.08%]) on follow-up. None of the patients mandated surgical therapy for IBD. CONCLUSIONS: Concomitant PSC in patients with IBD is uncommon in India and is associated with lower rates of development of malignancies.

Evaluation of Nutritional Characteristics Reveals Similar Prevalence of Malnutrition in Patients with Ulcerative Colitis and Crohn's Disease.

BACKGROUND: Inflammatory bowel disease (IBD) is associated with an increased risk of malnutrition and sarcopenia. AIMS: To evaluate the nutritional status of patients with IBD and determine the threshold values of different parameters of nutritional assessment to identify malnutrition. METHODS: This was a single-centre cross-sectional analysis of adult patients with IBD [ulcerative colitis (UC) and Crohn's disease (CD)] who underwent anthropometry [body mass index (BMI), mid upper arm circumference (MUAC) and triceps-fold thickness (TSF)], body composition analysis and assessment for sarcopenia [hand-grip strength and skeletal muscle index (SMI) at L3 vertebral level)]. Age- and gender-matched healthy adults served as controls. Malnutrition was defined according to the European Society of Clinical Nutrition and Metabolism (ESPEN) criteria. RESULTS: A total of 406 patients [336 (82.76%) UC and 70 (17.24%) CD; mean age 40.56 ± 13.67 years; 215 (52.95%) males] with IBD and 100 healthy controls (mean age 38.69 ± 10.90 years; 56 (56%) males) were enrolled. The mean BMI, MUAC, TSF thickness, fat and lean mass, hand-grip strength, and SMI at L3 vertebral level were lower in patients with IBD compared to controls. The prevalence of malnutrition was similar in UC and CD [24.40% (n = 82) and 28.57% (n = 20), respectively (p = 0.46)]. Thresholds for fat mass in females (15.8 kg) and visceral fat index in males (0.26) were both sensitive and specific to detect malnutrition. The cutoff values of MUAC and TSF thickness to identify malnutrition were 23.25 cm and 25.25 cm, and 16.50 mm and 8.50 mm, in females and males, respectively. CONCLUSION: Malnutrition and sarcopenia were common in patients with IBD, with the prevalence being similar in patients with both UC and CD.

Clinical spectrum of elderly-onset inflammatory bowel disease in India.

BACKGROUND/AIMS: Inflammatory bowel disease (IBD) is increasingly being recognized in elderly patients. Data on clinical spectrum of elderly-onset IBD patients is lacking from India. METHODS: A cross-sectional retrospective analysis of a prospectively maintained database of patients diagnosed with IBD was conducted at 2 centers in India. The clinical spectrum of elderly-onset IBD including demographic profile (age and sex), clinical presentation, disease characteristics (disease behavior and severity, extent of disease), and treatment were recorded and compared with adult-onset IBD. RESULTS: During the study period, 3,922 (3,172 ulcerative colitis [UC] and 750 Crohn's disease [CD]) patients with IBD were recorded in the database. A total of 186 patients (4.74%; 116 males [62.36%]) had elderly-onset IBD (69.35% UC and 30.64% CD). Diarrhea, blood in stools, nocturnal frequency and pain abdomen were the commonest presentations for UC, whereas pain abdomen, weight loss and diarrhea were the most frequent symptoms in CD. For both elderly onset UC and CD, majority of the patients had moderately severe disease. Left-sided colitis was the commonest disease location in UC. Isolated ileal disease and inflammatory behavior were the most common disease location and behavior, respectively in CD. 5-Aminosalicylates were the commonest prescribed drug for both elderly onset UC and CD. Thiopurines and biologics were used infrequently. Prevalence of colorectal cancer was higher in elderly onset IBD. CONCLUSIONS: Elderly onset IBD is not uncommon in India. Both the elderly onset UC and CD were milder, with no significant differences in disease characteristics (disease extent, location and behavior) when compared to adult-onset IBD. Colorectal cancer was more common in elderly onset IBD.

Correlation between magnetic resonance enterography and ileo-colonoscopy for assessment of disease activity in terminal ileal Crohn's disease.

BACKGROUND: Magnetic resonance enterography (MRE) has emerged as a novel tool for the assessment of disease activity in Crohn's disease (CD). Real world data from Indian subcontinent on performance of MRE in terminal ileal CD are lacking. METHODS: Retrospective analysis of patients with terminal ileal CD who underwent both ileo-colonoscopy and MRE was performed. Ileo-colonoscopy was considered the gold standard for assessment of disease activity. On ileo-colonoscopy, a simple endoscopic score for Crohn's disease (SES-CD) ≥2 was considered active disease; presence of ulcers indicated severe disease. MRE scoring of the disease activity was performed using magnetic resonance index of activity (MARIA) and simplified MARIA (MARIAs). The measure of agreement between ileo-colonoscopy and MRE and comparison of MARIA and MARIAs for assessment of disease activity and sensitivity of MRE to detect mucosal ulcerations were calculated. RESULTS: Seventy patients with terminal ileal CD (mean age 40.74±15.56 years; 71.4% males [n=50]) were evaluated. The sensitivities of MARIA and MARIAs scores to detect active disease were 0.76 and 0.84, respectively. The area under the receiver operating characteristic curve (AUROC) for detecting severe disease was 0.836 (p<0.0001) for MARIA and 0.861 (p<0.0001) for MARIAs. For mild active disease, there was no agreement between SES-CD and MARIA or MARIAs; however, for severe disease, the agreement was fair and moderate for MARIA and MARIAs, respectively. MARIA and MARIAs were comparable for identification of active and severe disease (κ 0.759, p<0.0001 and κ 0.840, p<0.0001, respectively). MRE was 68.18% sensitive to detect mucosal ulcers. CONCLUSION: MRE is a reliable and sensitive tool for detection of endoscopically severe, but not mild, terminal ileal CD.

Early fecal microbiome transfer after donor defecation determines response in patients with moderate to severe ulcerative colitis.

BACKGROUND: Fecal microbiome transfer (FMT) targeting gut microbiome dysbiosis is an emerging therapy for ulcerative colitis (UC). There is however no consensus on protocols for performing FMT in UC, especially in relation to time after donor feces defecation. METHODS: This is a single-center retrospective analysis of patients with moderate-severe UC (total Mayo Clinic score ≥6 and endoscopic Mayo Clinic subscore of ≥2) treated with FMT between September 2017 and December 2019 at Dayanand Medical College and Hospital, Ludhiana, India. Fresh fecal samples from unrelated healthy voluntary donors were administered through colonoscopy at weeks 0, 2, 6, 10, 14, 18, and 22. Time interval between donor feces defecation and FMT procedure was recorded for each FMT session and the mean time of seven sessions was designated aika. Impact of aika on clinical response and safety of FMT was evaluated. RESULTS: During the study period, 123 adult patients (mean age 33.75±11.97 years, 61.8% [n=76] males) with moderate-severe UC (mean total Mayo Clinic and endoscopic Mayo Clinic scores 7.49±1.60 and 2.50±0.50, respectively) were treated with FMT. The mean aika was 2.29±0.75 h. The aika was smaller in patients who responded to FMT as compared to non-responders (2.13±0.75 h vs. 2.71±0.76 h, p=0.0002) as well as in patients achieving clinical remission (2.15±0.76 h vs. 2.42±0.76 h, p=0.05). There was no significant impact of aika on adverse effects except for the incidence of borborygmi after FMT, which was higher in patients with aika ≤2 h. CONCLUSION: Early FMT after donor feces defecation favorably impacts the clinical response rates in patients with active UC.

Diagnostic Accuracy of Calculated Tumor Volumes and Apparent Diffusion Coefficient Values in Predicting Endometrial Cancer Grade.

Background: Magnetic resonance imaging (MRI) has been shown to be an accurate imaging technique for the preoperative assessment of local staging of endometrial cancer and for evaluating the depth of myometrial invasion. Materials and Methods: This was a single-center retrospective study performed on patients with histopathologically proven endometrial carcinoma who underwent an MRI examination of the pelvis between October 2017 and May 2020. Results: In the present analysis, mean apparent diffusion coefficient (ADC) values for each histologic grade were 0.72 ± 0.13 × 10-3 mm2/s (G1), 0.76 ± 0.17 × 10-3 mm2/s (G2), and 0.74 ± 0.12 × 10-3 mm2/s (G3), respectively, showing no significant correlation between ADC values and tumor grade (P = 0.73). Overall, ADC minimum was significant in differentiating grades of endometrial carcinoma (P = 0.02) with the ability to differentiate Grade I and II lesions (P = 0.01). A mean tumor volume of 25.2 cc could differentiate low-grade tumors (Grade I and Grade II) from high-grade tumors (Grade III) with a sensitivity and specificity of 88% and specificity of 89%. The tumor volume/uterine volume ratio (TV/UV) differentiates high-grade tumors from low-grade tumors (P < 0.001), however, no significant difference in the ratio was observed among Grade I and II lesions (P = 0.48). The area under the curve of tumor volume was 0.875 (95% confidence interval 0.0-1.00) (P = 0.001), indicating that tumor volume was an effective tool for distinguishing high-grade and low-grade endometrioid adenocarcinomas. The corresponding sensitivity and specificity were 88.0% and 89.0%, respectively. Conclusion: Preoperative noninvasive radiological assessment for tumor volume, TV/ UV or tumor volume/uterine volume is important surrogate markers for preoperative prognostication of endometrial carcinoma.

Adherence to Iron Chelation Therapy and Its Determinants.

Background: Thalassemia is a chronic disease requiring lifelong treatment. The adherence to regular iron chelation therapy is important to ensure complication-free survival and good quality of life. The study aim to assess the adherence to iron chelation therapy (ICT) in patients with transfusion-dependent thalassemia (TDT), evaluate various causes of non-adherence and study the impact of non-adherence on the prevalence of complications secondary to iron overload. Materials and Methods: Patients with TDT on ICT for > 6 months were enrolled in the study. Hospital records were reviewed for demographic details, iron overload status, treatment details, and the prevalence of complications. A study questionnaire was used to collect information on adherence to ICT, knowledge of patients, and the possible reasons for non-adherence.   Results:  A total of 215 patients with a mean age of 15.07+7.68 years and an M: F ratio of 2.2:1 were included in the study. Non-adherence to ICT was found in 10.7% of patients. Serum ferritin levels were significantly higher in the non-adherent group (3129.8+1573.2 µg/l) than the adherent population (2013.1+1277.1 µg/l). Cardiac as well as severe liver iron overload was higher in the non-adherent patients. No correlation was found between disease knowledge and adherence to ICT. Difficulties in drug administration and many medicines to be taken daily were statistically significant reasons for non-adherence. There was no difference in the co-morbidities arising due to the iron overload in the two groups. Conclusion: Nearly 11% of patients with TDT were non-adherent to ICT. Non-adherence results in higher iron overload.

Muscle strength and physical performance, rather than muscle mass, correlate with mortality in end-stage liver disease.

OBJECTIVES: Sarcopenia is characterized by the loss of skeletal muscle mass, strength and performance. The study aimed to provide cut off values of various Sarcopenia parameters [computerized tomography skeletal muscle index (SMI), handgrip strength (HGS), gait velocity and chair stand] to predict mortality in end-stage liver disease (ESLD). METHODS: The inclusion criteria were age 18-75 years, model for end-stage liver disease > 15. All patients with advanced heart, lung, kidney diseases, active malignancy were excluded from the study. Sarcopenia indices were compared between survivors and non-survivors to find cut off value for prediction of mortality in ESLD patients. RESULTS: One hundred sixty-one subjects suffering from ESLD were enrolled. The cutoff value of the SMI to identify high risk of mortality in sarcopenia patients is ≤21.2 cm2/m2, area under the curve (AUC) 0.537 [95% confidence interval (CI) 0.456-0.616]. The cutoff value of the hand grip strength to identify high-risk mortality is ≤25.3 kilogram-force, AUC 0.682 (95% CI 0.604-0.753). The cutoff value of the gait velocity for the same is as ≤0.84 m/s, AUC 0.551 (95% CI 0.459-0.641). The cutoff value of the chair stand is ≥20.9 seconds, AUC 0.956 (95% CI 0.910-0.983). In the multivariate analysis, HGS, gait velocity and chair stand correlated with mortality. CONCLUSION: The current study is a comprehensive Asian study that gives the cut off values of Sarcopenia: muscle mass, strength and performance which identify high risk of mortality in ESLD patients. Muscle strength and performance correlated with mortality.

Trends of inflammatory bowel disease at a tertiary care center in northern India.

BACKGROUND/AIMS: Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is increasingly being reported from India and other Asian countries. This study looks into the changing trends of IBD at a tertiary care center in north India over last two decades. METHODS: Retrospective analysis of a prospectively maintained database of patients diagnosed with IBD between January 1991 and December 2015 was conducted. The study period was divided into five times cohorts (1991-1995, 1996-2000, 2001-2005, 2006-2010, 2011-2015). RESULTS: During the study period, 2,467 patients (UC [n = 2,137, 86.6%], CD [n = 330, 13.3%], mean age 38.5 ± 13.3 years; 55.9% males) were registered. The proportion of patients with CD increased (ratio of UC to CD declined from 15.7:1 to 4:1). The mean age at diagnosis decreased for UC (45.7 ± 12.1 years in 1991-1995 vs. 37.6 ± 13.0 years in 2011-2015; P= 0.001) and remained consistent for CD (41.3 ± 13.6 years in 1996-2000 vs. 41.3 ± 16.9 years in 2011-2015, P= 0.86). Patients with proctitis in UC and isolated ileal disease in CD increased over the study period (P= 0.001 and P= 0.007, respectively). Inflammatory CD increased (P= 0.009) whereas stricturing CD decreased (P= 0.01) across all cohorts. There was a trend towards less severe presentation of both UC and CD. The use of thiopurines (P= 0.02) and biologics increased (P= 0.001) with no significant change in trends for requirements of surgery (P= 0.9). CONCLUSIONS: Increasing prevalence of CD, younger age at diagnosis, diagnosis at an earlier and milder stage, greater use of thiopurines and biologics were observed.

Video-assisted thoracoscopic surgery versus open thoracotomy in the management of empyema: A comparative study.

INTRODUCTION: With a rise in the incidence of thoracic empyema, surgical interventions also have evolved from the traditional open decortication to the current minimally invasive video-assisted thoracoscopic surgery (VATS). In this study, we determine the feasibility of VATS and also put the superiority of VATS over open thoracotomy (OT) to test. SUBJECTS AND METHODS: Prospective single-centre comparative analysis of clinical outcome in 60 patients undergoing either VATS or OT for thoracic empyema was done between 1st September, 2014, and 1st November, 2018. Furthermore, another group of patients, who were converted intraoperatively from VATS to OT, was studied descriptively. RESULTS: Nearly 75% of the patients were male with a mean age of 45.16 years. Every second patient had associated tuberculosis (TB), attributed to the endemicity of TB in India. When compared with OT, VATS had a shorter duration of surgery (268.15 vs. 178.33 min), chest tube drainage (11.70 vs. 6.13 days), post-operative hospital stay (13.56 vs. 7.42 days) and time to return to work (26.96 vs. 12.57 days). Post-operative pain and analgesic requirement were also significantly reduced in the VATS group (P < 0.0001). Conversion rate observed was 14.2%, the most common reason being the presence of dense adhesions. CONCLUSION: We conclude that VATS, a minimally invasive procedure with its substantial advantages over thoracotomy and better functional outcome, should be preferred whenever feasible to do so. Also if needed, conversion of VATS to the conventional open procedure, rather than a failure, is a wise surgical judgement.

Clinical Predictors of response to Faecal Microbiota Transplantation in patients with active ulcerative colitis.

BACKGROUND: Fecal Microbiota Transplantation (FMT) has been shown to be effective for induction of remission in patients with active ulcerative colitis (UC). At present, clinical factors impacting the response to FMT in UC remain unclear. METHODS: Patients with active UC treated with multisession FMT via colonoscopy at weeks 0, 2, 6, 10, 14, 18, and 22, were analysed. Response to FMT was defined as achievement of corticosteroid free clinical remission at week 30. Patient and disease characteristics were evaluated to determine the predictors of response to FMT. RESULTS: Out of 140 patients with active UC treated with FMT, 93 patients [mean age 34.96±11.27 years, 62.36% males (n=58), mean Mayo clinic score 8.07±2.00] who completed the multi-session FMT protocol were analysed. Fifty-seven (61.29%) patients achieved clinical remission. Younger age (OR for age 0.93, 95% CI 0.89-0.97, p=0.001), moderate (Mayo clinic score 6-9) disease severity (OR 3.01, 95% CI 1.12 to 8.06, p=0.025) and endoscopic Mayo score 2 (OR 5.55, 95% CI 2.18-14.06, p<0.001) were significant predictors of remission on univariate analysis. Younger age, disease extent E2 and endoscopic mayo score 2 (OR 0.925, 95% CI 0.88-0.97, p=0.002; OR 2.89, 95% CI 1.01-8.25, p=0.04 and OR 8.43, 95% CI 2.38-29.84, p=0.001, respectively) were associated with clinical remission on multivariate logistic regression. A mathematical model (nomogram) was developed for estimating the probability of remission with FMT protocol. CONCLUSION: Younger age, disease extent E2, and endoscopic mayo score 2 significantly predict achievement of clinical remission with FMT in active UC. The prediction model can help in selecting individuals for FMT. Validation in larger cohorts is needed.

Early onset ACS: An age based clinico-epidemiologic and angiographic comparison.

BACKGROUND AND AIMS: Acute coronary syndrome (ACS) in the very young is a rare entity, with limited data. We aimed to study patterns and profile of ACS in patients aged 20-30 years in comparison with those above 30 years. METHODS: In this retrospective record-based study, the demographic and clinical profile of all patients with ACS in the last 12 years (n = 35259) was analysed: group I (20-30 years) and group II (above 30 years). Patients in group II were selected by systematic sampling. Age, gender, domicile, body mass index (BMI), serum cholesterol, smoking, alcohol use, drug abuse, diabetes, hypertension, family history, type of ACS, angiographic findings and management strategies were recorded. Chi-square test and Fischer's exact test were used for data analysis. RESULTS: Of 35,259 patients, 0.32% (n = 114) were from the younger age group, with a rising trend of prevalence over 12 years. Obesity, overweight, urban living, smoking, alcohol and drug abuse were significantly higher in group I (p < 0.05). Diabetes mellitus and hypertension were more prevalent in group II (p = 0.001). STEMI in group I (76.3%) and NSTEMI in group II (47.1%) were the common modes of presentation (p = 0.001). 42.1% of group I patients had recanalized coronaries with conservative management in comparison to 3% in group II (p = 0.001). CONCLUSIONS: There is a rising trend in prevalence of ACS in very young patients. Overweight, obesity, urbanization and drug abuse are potential risk factors. The younger subset of ACS patients is different from the older population due to their thrombotic milieu, which could be more amenable to intensive pharmacologic management.

Knowledge about Informed Consent among Doctors of Various Specialities: A Pilot Survey.

BACKGROUND: Informed consent is an integral part of clinical practice. Improper informed consent can lead to mistrust between doctors and patients as well as medico-legal issues. Awareness and knowledge of various aspects of consent is essential in present day medical practice. METHODS: A paper and web-based survey was undertaken to evaluate knowledge about informed consent among doctors. A law and a medical student generated a list of questions based upon available case laws and legislations which were further validated by experts. 500 doctors undertook the survey and of these 457 completed the survey of 18 questions. Both univariate and multivariate models were used to analyze responses. RESULTS: 413 complete questionnaires were included in the analysis. The proportion of respondents furnishing correct responses varied between 49.6% and 93.7%. There were 9 questions for which, over 25% respondents provided inappropriate responses. The questions included those enquiring whether initial consent for diagnostic or therapeutic procedures could apply to extended procedures or surgery and who was capable of giving consent for different procedures. There were significant differences of knowledge between residents and consultants for few questions. The physicians fared worse than surgeons and anesthetists although the difference was not statistically significant. CONCLUSION: Significant knowledge gaps were identified. There were deficiencies in providing correct response particularly in practical scenarios. There is a need to include knowledge about different aspects of informed consent in the medical curriculum.

Inhibition of pro-HGF activation by SRI31215, a novel approach to block oncogenic HGF/MET signaling.

The binding of hepatocyte growth factor (HGF) to its receptor MET activates a signaling cascade that promotes cell survival, proliferation, cell scattering, migration and invasion of malignant cells. HGF is secreted by cancer cells or by tumor-associated fibroblasts as pro-HGF, an inactive precursor. A key step in the regulation of HGF/MET signaling is proteolytic processing of pro-HGF to its active form by one of the three serine proteases, matriptase, hepsin or HGF activator (HGFA).We developed SRI 31215, a small molecule that acts as a triplex inhibitor of matriptase, hepsin and HGFA and mimics the activity of HAI-1/2, endogenous inhibitors of HGF activation. We demonstrated that SRI 31215 inhibits fibroblast-induced MET activation, epithelial-mesenchymal transition and migration of cancer cells. SRI 31215 overcomes primary resistance to cetuximab and gefitinib in HGF-producing colon cancer cells and prevents fibroblast-mediated resistance to EGFR inhibitors. Thus, SRI 31215 blocks signaling between cancer cells and fibroblasts and inhibits the tumor-promoting activity of cancer-associated fibroblasts.Aberrant HGF/MET signaling supports cell survival, proliferation, angiogenesis, invasion and metastatic spread of cancer cells, establishing HGF and MET as valid therapeutic targets. Our data demonstrate that inhibitors of HGF activation, such as SRI 31215, merit investigation as potential therapeutics in tumors that are addicted to HGF/MET signaling. The findings reported here also indicate that inhibitors of HGF activation overcome primary and acquired resistance to anti-EGFR therapy, providing a rationale for concurrent inhibition of EGFR and HGF to prevent therapeutic resistance and to improve the outcome of cancer patients.

Design and Synthesis of Nonpeptide Inhibitors of Hepatocyte Growth Factor Activation.

In this letter we report first nonpeptide inhibitors of hepatocyte growth factor (HGF) activation. These compounds inhibit the three proteases (matriptase, hepsin, and HGF activator) required for HGF maturation. We show that 6, 8a, 8b, and 8d block activation of fibroblast-derived pro-HGF, thus preventing fibroblast-induced scattering of DU145 prostate cancer cells. Compound 6 (SRI 31215) is very soluble (91 µM) and has excellent microsome stability (human t 1/2 = 162 min; mouse t 1/2 = 296 min). In mouse 6 has an in vivo t 1/2 = 5.8 h following IV administration. The high solubility of 6 and IV t 1/2 make this compound a suitable prototype "triplex inhibitor" for the study of the inhibition of HGF activation in vivo.

Metabolism of 2-methyladenosine in Mycobacterium tuberculosis.

2-Methyladenosine (methyl-Ado) has selective activity against Mycobacterium tuberculosis (M. tuberculosis). In an effort to better understand its mechanism of action, we have characterized its metabolism in M. tuberculosis cells. The primary intracellular metabolite of methyl-Ado was 2-methyl-adenylate (methyl-AMP). Very little of the methyl-AMP was metabolized further. A M. tuberculosis strain that was resistant to methyl-Ado did not express adenosine kinase and did not convert methyl-Ado to methyl-AMP in intact cells. In contrast to these results, the primary intracellular metabolite of adenosine in M. tuberculosis cells was ATP, which was readily incorporated into RNA. The rate of metabolism of methyl-Ado to methyl-AMP was similar to the rate of metabolism of adenosine to ATP. Treatment of M. tuberculosis with methyl-Ado did not affect intracellular ATP levels. Methyl-Ado and Ado were also cleaved to 2-methyladenine and adenine, respectively, which accumulated in the medium outside the cells. These studies suggested that methyl-AMP was the active metabolite responsible for the cytotoxicity of this agent. Furthermore, because methyl-Ado was poorly metabolized in human cells, these studies indicated that the selective activity of methyl-Ado was due to its selective activation by M. tuberculosis. These studies have identified two enzyme reactions (Ado kinase and Ado cleavage) in M. tuberculosis that could be exploited for the rational design of new and selective anti-M. tuberculosis agents.

Antimycobacterial activity of 2-methyl-adenosine.

OBJECTIVES: The aims of this study were to assess the in vitro activity of 2-methyl-adenosine against Mycobacterium tuberculosis and evaluate, and to intracellular efficacy, and to evaluate its effectiveness against M. tuberculosis in a persistent state model and examine its potential mechanism of action. METHODS: In vitro activity was determined by means of a colorimetric microdilution broth assay. Intracellular activity was assessed with a Mono Mac 6 human monocytic cell line. A hypoxic shift-down model was used to evaluate the effect of 2-methyl-adenosine on M. tuberculosis in a persistent state. Mechanism-of-action studies were conducted by examining the effect of 2-methyl-adenosine on the uptake of appropriate radiolabelled precursors into respective mycobacterial macromolecular components. RESULTS: Studies confirmed the in vitro activity of 2-methyl-adenosine against M. tuberculosis and demonstrated intracellular efficacy against M. tuberculosis within macrophages. 2-Methyl-adenosine was able to significantly affect the viability of M. tuberculosis in a hypoxic shift-down model previously described to simulate the persistent state that results during tuberculosis. Mechanism-of-action studies revealed that the immediate inhibitory effects of 2-methyl-adenosine were associated with protein and DNA synthesis and not RNA synthesis. CONCLUSIONS: Results indicate that 2-methyl-adenosine, or similar derivatives, might be effective against M. tuberculosis infections during latency. This information should be helpful in understanding purine metabolism of M. tuberculosis and also the metabolic activity of this important human pathogen in the persistent state.

The metabolism of 2-methyladenosine in Mycobacterium smegmatis.

2-Methyladenosine (methyl-ado) has demonstrated selective activity against Mycobacterium tuberculosis, which indicates that differences in the substrate preferences between mycobacterial and human purine metabolic enzymes can be exploited to develop novel drugs for the treatment of mycobacterial diseases. Therefore, in an effort to better understand the reasons for the anti-mycobacterial activity of methyl-ado, its metabolism has been characterized in Mycobacterium smegmatis. In a wild-type strain, methyl-ado was phosphorylated by adenosine kinase to methyl-AMP, which was further converted to methyl-ATP and incorporated into RNA. In contrast, a mutant strain of M. smegmatis was isolated that was resistant to methyl-ado, deficient in adenosine kinase activity and was not able to generate methyl-ado metabolites in cells treated with methyl-ado. These results indicated that phosphorylated metabolites of methyl-ado were responsible for the cytotoxic activity of this compound. Methyl-ado was not a substrate for either adenosine deaminase or purine-nucleoside phosphorylase from M. smegmatis. Treatment of M. smegmatis with methyl-ado resulted in the inhibition of ATP synthesis, which indicated that a metabolite of methyl-ado inhibited one of the enzymes involved in de novo purine synthesis. These studies demonstrated the importance of adenosine kinase in the activation of methyl-ado to toxic metabolites in M. smegmatis.