Perioperative Management of Spontaneous Intracranial Hemorrhage in a Patient With Hemophilia A in a Resource Limited Country

Intracranial hemorrhage (ICH) is a serious complication of hemophilia A with high morbidity and mortality. The management of such cases is complicated by nonspecific and often delayed presentation, increased frequency of rebleeding, low awareness regarding clotting factor replacement, and debate regarding the efficacy of surgical interventions. We report a case of an 18-year-old male patient with hemophilia A, who first presented to the emergency department in India in a comatose state. Neuroimaging revealed subdural hematoma with midline shift and uncal herniation. The patient was successfully managed with perioperative cryoprecipitate and factor VIII replacement, tiered intracranial pressure lowering strategies, and early decompressive craniectomy with clot evacuation. In India, there are no standardized guidelines for screening and routine care for hereditary diseases like hemophilia. In a resource-deficient country, management was complicated by the limited availability of factor VIII in the emergent setting, as well as the inability to obtain serial factor levels in the postoperative period. We hope that this article helps to guide the management of ICH and hemophilia in resource-limited countries.

Clozapine therapeutic drug monitoring – experience from a large London NHS trust

Introduction

Clozapine is a high-risk drug that is used widely in Secondary and Tertiary Centres.1 Therapeutic Drug Monitoring (TDM) advice and recommendation is readily available from distinguished authors.2,3 The rate of clozapine TDM, appropriate sample collection for TDM, appropriate actions following a clozapine level varies between services and prescribers within our organisation.

Aim

To establish how many current West London NHS Trust (WLT) patients had a clozapine TDM, how many plasma samples collected for TDM were done appropriately, the proportion of patients with an appropriately collected plasma sample result within the largely accepted therapeutic range, and whether there was documentation that the plasma level was reviewed and if any prescription changes were made.

Methods

Approval to undertake the service evaluation was given by the Trust clinical governance and audit committee as ethical review as not required. No patient identifiable details were shared or collected. All patients who had been registered on the Trusts clozapine patient monitoring service for over 8 weeks were enrolled. Anonymised patient demographic data was collected including concomitant medication. Plasma levels were sought for every patient enrolled. The appropriateness of the samples taken were scrutinised. The plasma level result was collected. Electronic patient notes were also scrutinised to assess actions following the plasma level result. Data were collected in a binary yes/no format and results calculated as a percentage. Data was stored and collected in accordance to Trust General Data Protection Regulation (GDPR).

Results

In total 316 patients were included. 97% of these patients had evidence of TDM levels done during the time of the audit. 88% of these patients’ samples were done correctly. Only 45% of patients had levels within the widely acceptable therapeutic range. Of those patients whose levels fell outside the therapeutic range less than half (42%) had documentation that the level was reviewed.

Discussion/Conclusion

It is widely accepted that clozapine TDM when done accurately can be a vital source of information to inform prescribers on the appropriate dose, concordance and toxicity of clozapine therapy. Our Trust showed evidence of routine clozapine TDM. There was some variation in the appropriate sample collection but what was most alarming is the lack of documentation that action was taken when the TDM level was outside the general acceptable range. Standardising the actions following clozapine TDM needs to be a priority for the Trust if clozapine TDM is to continue to be carried out in almost 100% of the patient population.

References

1. Taylor DM, Barnes TRE, Young AH. The Maudsley Prescribing Guidelines in Psychiatry 14th Edition. Wiley Blackwell.

2. Taylor DM et al. The use of clozapine plasma levels in optimising therapy. Psych Bull 1995:19:753-755

3. Perry PJ. Therapeutic drug monitoring of antipsychotics. Psychopharmacology 200; 148:83-89

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Clinical correlation and assessment of olfactory dysfunction with n-butanol in COVID-19 patients: our experience

Background: Studies showed olfactory disturbances in COVID patients. This has attracted focus of clinicians as an easy clinical screening tool in suspected population. Material and methods: 70 mild and moderate category COVID-19 RT-PCR positive patients, more than 10 years of age were tested on day of admission for olfaction with serial dilution of n-butanol and asked to grade severity of their olfactory dysfunction according to visual analogue score from 1-10. Results: Fatigue 42 (93.33%), sore throat 37 (82.22%), fever 36 (80%) and dyspnea 23 (51.11%) were the most common symptoms in moderate patients. Diabetes, hypertension and allergy were the three prominent risk factors. At time of admission, n-butanol diagnosed 20 patients having olfactory dysfunction compared to 11 by VAS. Patients tend to grade their dysfunction higher on VAS whereas the n-butanol test classified their olfactory dysfunction lower. Viral load and high CRP were not found to be significantly related with olfactory dysfunction. d-Dimer and LDH levels were found statistically associated with higher grading of olfactory dysfunction detected by n-butanol. Conclusion: The majority of cases developed hyposmia before they were admitted to hospital even before they realized that they were having hyposmia as revealed by n-butanol testing. We should go for objective tests of olfaction.

Impact of early versus late tracheostomy on patient outcomes in a tertiary care multispeciality ICU

Background and Aims:

Tracheostomy is a commonly performed procedure in critically ill patients because patients requiring chronic mechanical ventilation (MV) are rising by as much as 5.5% per year. The controversy on likely benefits of early versus late tracheostomy is ongoing. We aimed to study the impact of early versus late tracheostomy on patient outcomes.

Material and Methods:

A retrospective observational study was performed in intensive care unit (ICU) patients who underwent tracheostomy in a 31-bedded multispeciality ICU of a 350-bedded tertiary care hospital, over a period of 1 year. Data collected included the age, sex, APACHE II score, indication for tracheostomy, timing of procedure, whether surgical or percutaneous, any complication, MV days, ICU stay, and patient outcome. Patients were divided into two groups for statistical comparison: early ≤7 days and late >7 days of MV.

Results:

A total of 102 patients underwent tracheostomy over the study period, of which 19 were excluded because of inadequate data and exclusion criteria. Of the 83 study patients, 60 had percutaneous, while 23 had surgical tracheostomy. About 51 (61.45%) had early, while 32 (38.55%) had late tracheostomy. On statistical analysis, there was a significant difference in MV days (5 vs 12.5 days, P = 0.002), ICU stay (10 vs 16 days, P = 0.004), mortality (21.6% vs 43.8%, P = 0.032), and decannulation rate (29.41% vs 6.25%, P = 0.009). No difference was observed in hospital stay or complication rates.

Conclusion:

Early tracheostomy is associated with both morbidity and mortality benefits. Patients requiring MV should be given an option of early tracheostomy.

Time-resolved relaxation and fragmentation of polycyclic aromatic hydrocarbons investigated in the ultrafast XUV-IR regime

Polycyclic aromatic hydrocarbons (PAHs) play an important role in interstellar chemistry and are subject to high energy photons that can induce excitation, ionization, and fragmentation. Previous studies have demonstrated electronic relaxation of parent PAH monocations over 10-100 femtoseconds as a result of beyond-Born-Oppenheimer coupling between the electronic and nuclear dynamics. Here, we investigate three PAH molecules: fluorene, phenanthrene, and pyrene, using ultrafast XUV and IR laser pulses. Simultaneous measurements of the ion yields, ion momenta, and electron momenta as a function of laser pulse delay allow a detailed insight into the various molecular processes. We report relaxation times for the electronically excited PAH^*, PAH^+* and PAH^2+* states, and show the time-dependent conversion between fragmentation pathways. Additionally, using recoil-frame covariance analysis between ion images, we demonstrate that the dissociation of the PAH²⁺ ions favors reaction pathways involving two-body breakup and/or loss of neutral fragments totaling an even number of carbon atoms.

Identification and stratification of systemic lupus erythematosus patients into two transcriptionally distinct clusters based on IFN-I signature

OBJECTIVE

Despite the significant advancement in the understanding of the pathophysiology of systemic lupus erythematosus (SLE) variable clinical response to newer therapies remain a major concern, especially for patients with lupus nephritis and neuropsychiatric systemic lupus erythematosus (NPSLE). We performed this study with an objective to comprehensively characterize Indian SLE patients with renal and neuropsychiatric manifestation with respect to their gene signature, cytokine profile and immune cell phenotypes.

METHODS

We characterized 68 Indian SLE subjects with diverse clinical profiles and disease activity and tried to identify differentially expressed genes and enriched pathways. To understand the temporal profile, same patients were followed at 6 and 12-months intervals. Additionally, auto-antibody profile, levels of various chemokines, cytokines and the proportion of different immune cells and their activation status were captured in these subjects.

RESULTS

Multiple IFN-related pathways were enriched with significant increase in IFN-I gene signature in SLE patients as compared to normal healthy volunteers (NHV). We identified two transcriptionally distinct clusters within the same cohort of SLE patients with differential immune cell activation status, auto-antibody as well as plasma chemokines and cytokines profile.

CONCLUSIONS

Identification of two distinct clusters of patients based on IFN-I signature provided new insights into the heterogeneity of underlying disease pathogenesis of Indian SLE cohort. Importantly, patient within those clusters retain their distinct expression dynamics of IFN-I signature over the time course of one year despite change in disease activity. This study will guide clinicians and researchers while designing future clinical trials on Indian SLE cohort.

Mild Encephalopathy/Encephalitis with Reversible Splenial Lesion in a Patient with Salmonella typhi Infection: An Unusual Presentation with Excellent Prognosis

Mild encephalopathy/encephalitis with reversible splenial lesion (MERS) is an uncommon clinicoradiological entity reported mainly in East Asian population. Mild encephalopathy/encephalitis with reversible splenial lesion is characterized by neuropsychiatric manifestations, magnetic resonance imaging (MRI) findings of the reversible lesions in the splenium of corpus callosum, and good clinical outcomes. These transient splenial lesions are not specific to a particular condition and have been described mainly in children in various situations including epilepsy or peri-ictal state, antiepileptic drug use, and infectious agents such as influenza virus, Mycoplasma pneumoniae, Legionella pneumophila, and O-157 Escherichia coli. Mild encephalopathy/encephalitis with reversible splenial lesion is an uncommon complication of Salmonella infection and has been described earlier in a child who made excellent clinical recovery. We report a case of Salmonella typhi encephalopathy in a young adult who presented with reversible transient splenial lesions on MRI. The patient recovered without neurological sequelae. Awareness of these lesions is important as these are uncommon findings on MRI and carry excellent prognosis.

How to cite this article

Chopra P, Bhatia RS, Chopra R. Mild Encephalopathy/Encephalitis with Reversible Splenial Lesion in a Patient with Salmonella typhi Infection: An Unusual Presentation with Excellent Prognosis. Indian J Crit Care Med 2019;23(12):584-586.

Emerging therapeutic interventions for idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a devastating and relentlessly progressive lung disorder. Previously, it was thought to be a chronic inflammatory disease; however, it is now considered to be an epithelial-fibroblastic disease. In accordance with this paradigm change, efforts toward the development of novel therapeutic targets for IPF have acquired a new direction. Currently available therapies are largely ineffective in reversing the lung damage, and lung transplantation is the only effective treatment for end-stage disease. Limitations in advancement of IPF therapeutics are due to a poor understanding of its pathogenesis, unavailability of reliable animal models and slow disease progression. Recent research on IPF has resulted in the identification of a plethora of novel targets that are in various stages of development and offers hope that in the near future that there will be better therapeutic options available for the treatment of IPF.

AREAS COVERED

This review discusses existing therapies and highlights some of the recent, novel therapeutics being explored in the current clinical landscape for the treatment of this chronic, disabling disorder. The review also discusses the pathogenic rationale behind current therapies.

EXPERT OPINION

Targeting one fibrotic signaling pathway at a time may not have any significant effect on the control of IPF. It is therefore recommended that future IPF management focuses on targeting multiple pro-fibrotic pathways associated with its complex pathogenesis.

Hepatocyte growth factor is an attractive target for the treatment of pulmonary fibrosis

INTRODUCTION

Pulmonary fibrosis (PF) is a progressive fatal disorder and is characterized by alveolar epithelial injury, myofibroblast proliferation, and extracellular matrix remodeling, resulting in irreversible distortion of lung's architecture. Available therapies are associated with side effects and show restricted efficacy. Therefore, there is an urgent need to find a therapeutic solution to PF. Therapeutic strategies interfering myofibroblast expansion, apoptosis of epithelial and endothelial cells might be beneficial for treatment of PF. Hepatocyte growth factor (HGF), a pleiotropic growth factor, plays an important role in lung development, inflammation, repair, and regeneration. In animal model of PF, administration of recombinant HGF protein or ectopic HGF expression ameliorates fibrosis.

AREAS COVERED

The focus of this review is to highlight HGF as a promising therapeutic approach for the treatment of PF. The review discusses the currently available treatment option for PF as well as highlights the possible beneficial effect of HGF as a drug target.

EXPERT OPINION

HGF with its anti-fibrotic effect provides a promising new therapeutic approach by protecting lung from fibrotic remodeling and also promoting normal regeneration of lung. The development of HGF mimetics may provide a potential attractive therapy for treatment of this devastating and complex disease.

Biochemical characterization of an S-adenosyl-l-methionine-dependent methyltransferase (Rv0469) of Mycobacterium tuberculosis

Tuberculostearic acid (l0-methylstearic acid, TSA) is a major constituent of mycobacterial membrane phospholipids, and its biosynthesis involves the direct methylation of oleic acid esterified as a component of phospholipids. The methyltransferases of mycobacteria were long proposed to be involved in the synthesis of methyl-branched short-chain fatty acids, but direct experimental evidence is still lacking. In this study, we identified the methyltransferase encoded by umaA in Mycobacterium tuberculosis H37Rv as a novel S-adenosyl-l-methionine (SAM)-dependent methyltransferase capable of catalyzing the conversion of olefinic double bond of phospholipid-linked oleic acid to biologically essential TSA. Therefore, UmaA, catalyzing such modifications, offer a viable target for chemotherapeutic intervention.

Chirality and anaesthetic drugs: A review and an update

Many molecules can exist as right-handed and left-handed forms that are non-superimposable mirror images of each other. They are known as enantiomers or substances of opposite shape. Such compounds are also said to be chiral (Greek chiros meaning ‘hand’). Such chiral molecules are of great relevance to anaesthetic theory and practice. This review summarizes the basic concepts, pharmacokinetic and pharmacodynamic aspects of chirality, and some specific examples of their application in anaesthesia, along with recent advances to elucidate the anaesthetic mechanisms. Chirality is relevant to anaesthesia, simply because more than half of the synthetic agents used in anaesthesia practice are chiral drugs. Almost all these synthetic chiral drugs are administered as racemic mixture, rather than as single pure enantiomers. These mixtures are not drug formulations containing two or more therapeutic substances, but combination of isomeric substances, with the therapeutic activity residing mainly in one of the enantiomer. The other enantiomer can have undesirable properties, have different therapeutic activities or be pharmacologically inert. Specific examples of application of chirality in anaesthetic drugs include inhalational general anaesthetics (e.g. isoflurane), intravenous anaesthetics (e.g. etomidate, thiopentone), neuromuscular blocking agents (e.g. cisatracurium), local anaesthetics (e.g. ropivacaine and levobupivacaine) and other agents (e.g. levosimendan, dexmedetomidine, L-cysteine). In the recent advances, chirality study has not only helped new drug development as mentioned above, but has also contributed in a more profound way to the understanding of the mechanism of anaesthesia and anaesthetic drugs.

Aspergillus vertebral osteomyelitis in immunocompetent patients

Fungal infections are one of the important cause of morbidity and mortality in immunocompromised patients. Aspergillus vertebral osteomyelitis is extremely rare. We report two cases of aspergillus vertebral osteomyelitis in immunocompetent men in the absence of an underlying disorder. The clinical and radiological findings were suggestive of Pott's spine. The absolute CD4, CD8 counts and their ratio were normal. The HIV status was negative in both patients. Both patients underwent surgical decompression. The histopathology of tissue obtained were suggestive of aspergillus osteomyelitis. One patient had antifungal treatment for 3 months and was doing well at 1 year followup, whereas other patient did not turnup after 2 months.

Polo-like kinase inhibitors: an emerging opportunity for cancer therapeutics

IMPORTANCE OF THE FIELD

The Polo-like kinase (Plk) family has emerged as an important regulator in cell cycle progression. Plks belong to a family of serine/threonine kinases and exist in four isoforms Plk1- 4. However, only one of these isoforms, Plk1, is shown to be involved in the activation of Cdc2, chromosome segregation, centrosome maturation, bipolar spindle formation and execution of cytokinesis. The activity of Plk1 is elevated in tissues and cells with a high mitotic index. In patients, Plk1 is overexpressed in tumors including those derived from lung, breast, colon, pancreas, prostate and ovary. Plk1 depletion is associated with the decrease in cell viability and induction of apoptosis in various cancerous cells. Several Plk1 inhibitors are in different phases of clinical development for anticancer therapy.

AREAS COVERED IN THIS REVIEW

The focus of present review is to highlight Plk1 as a promising therapeutic approach for the treatment of cancer. The review discusses the role of Plk1 in cancer and the current status of Plk1 inhibitors, as well as highlighting the possible beneficial effect of inhibition of Plk1 as compared to other mitotic targets.

WHAT THE READER WILL GAIN

Readers will get a comprehensive overview of Plk1 as a novel anticancer drug target. This review will also update readers about the progress made in the field of Plk1 inhibitors.

TAKE HOME MESSAGE

The current literature about Plk1 inhibitors and knockout studies favor Plk1 inhibition as a potential antitumor therapy.

Polo-like kinase inhibitors: an emerging opportunity for cancer therapeutics

IMPORTANCE OF THE FIELD

The Polo-like kinase (Plk) family has emerged as an important regulator in cell cycle progression. Plks belong to a family of serine/threonine kinases and exist in four isoforms Plk1- 4. However, only one of these isoforms, Plk1, is shown to be involved in the activation of Cdc2, chromosome segregation, centrosome maturation, bipolar spindle formation and execution of cytokinesis. The activity of Plk1 is elevated in tissues and cells with a high mitotic index. In patients, Plk1 is overexpressed in tumors including those derived from lung, breast, colon, pancreas, prostate and ovary. Plk1 depletion is associated with the decrease in cell viability and induction of apoptosis in various cancerous cells. Several Plk1 inhibitors are in different phases of clinical development for anticancer therapy.

AREAS COVERED IN THIS REVIEW

The focus of present review is to highlight Plk1 as a promising therapeutic approach for the treatment of cancer. The review discusses the role of Plk1 in cancer and the current status of Plk1 inhibitors, as well as highlighting the possible beneficial effect of inhibition of Plk1 as compared to other mitotic targets.

WHAT THE READER WILL GAIN

Readers will get a comprehensive overview of Plk1 as a novel anticancer drug target. This review will also update readers about the progress made in the field of Plk1 inhibitors.

TAKE HOME MESSAGE

The current literature about Plk1 inhibitors and knockout studies favor Plk1 inhibition as a potential antitumor therapy.

Development of cell death-based method for the selectivity screening of caspase-1 inhibitors

Caspase-1 selective inhibitors are novel therapeutic agents for inflammatory diseases. Selectivity assays for caspases can be initiated with purified enzyme, making these assays very costly and time consuming. Therefore, there is a need to develop a fast and reliable cell-based assay, which can be used for the selectivity screening of multiple caspases in a biologically relevant context in a single assay. In this study, we have developed an assay in which DNA fragmentation, a hallmark of apoptosis, of Jurkat cell line was examined post induction with etoposide in the presence or absence of inhibitors of caspases 1, 3, 8, 9 and pan-caspase inhibitors. We observed that caspases-3, -8, -9 and pan caspase inhibitors resulted in significant inhibition of etoposide-induced DNA fragmentation. However, caspase-1 specific inhibitor failed to prevent DNA fragmentation, suggesting that either caspases belonging to caspase-1 family (1, 4 and 5) are not present in the Jurkat cells or might not be involved in the etoposide-induced DNA fragmentation. Since the inhibition of caspases 3, 8 and 9 is accompanied by the down regulation of the activity of a cascade of caspases (caspases 2, 6, 7, 9 and 10), selectivity of caspase-I inhibitors can be ascertained for the above panel (caspases 2, 6, 7, 8, 9 and 10) of caspases from this single assay.

Patients with symptomatic primary hyperparathyroidism: an anaesthetic challenge

Primary hyperparathyroidism is a disease characterized by hypercalcaemia attributable to autonomous overproduction of parathormone. Many patients with primary hyperparathyroidism are asymptomatic. Osteoporosis and nephrolithiasis are some of the major sequelae seen in the symptomatic patients. Parathyroidectomy is the only curative therapy. However anaesthetic management of such patients may be problematic with associated cardiac arrhythmias and skeletal muscle weakness. Low serum albumin and alteration in the acid base status in the perioperative period can affect the serum calcium level and thus adds to the existing problem. We present the successful anaesthetic management of a patient with primary hyperparathyroidism who initially presented with pathological fractures, and discuss the anaesthetic issues involved.

Mucin-producing signet ring cell adenoma of the thyroid

Signet ring cell adenoma of the thyroid, though rare, is well documented. This change is chiefly due to intracellular accumulation of thyroglobulin that appears mucinous. Awareness of this entity is important as it may closely simulate a metastatic mucin-secreting signet ring cell carcinoma. Although the mucinous material in signet ring cells has been reported to stain positive with thyroglobulin, in some cases it may not be so. We herein describe a rare case of a 46-year-old man who was hypothyroid and the mass removed from the thyroid showed a mucin-producing signet ring cell adenoma of the thyroid.

Therapeutic potential of inhaled p38 mitogen-activated protein kinase inhibitors for inflammatory pulmonary diseases

BACKGROUND

Over the past two decades, p38 MAPK (mitogen-activated protein kinase) has been the subject of intense multidisciplinary research. p38 MAPK inhibitors have been shown to be efficacious in several disease models, including rheumatoid arthritis, psoriasis, Crohn's disease, and stroke. Recent studies support a role for p38 MAPK in the development, maintenance, and/or exacerbation of a number of pulmonary diseases, such as asthma, cystic fibrosis, idiopathic pulmonary fibrosis, and chronic obstructive pulmonary disease (COPD).

OBJECTIVE

Many previous attempts to develop p38 MAPK inhibitors have failed as a result of unacceptable safety profiles. These toxicities have been varied and are believed to derive from different off-target effects.

METHOD

The above concerns can be overcome by delivering the compound locally to minimize whole-body burden, resulting in low exposure to the gastrointestinal, liver, and CNS. This review discusses the role of p38 MAPK in various inflammatory diseases, followed by the toxicity concerns associated with p38 MAPK inhibition. It also highlights the possible beneficial effect of delivering drugs via the inhalation route.

CONCLUSION

We present proof-of-principle confirming the therapeutic potential of inhaled p38 inhibitors for asthma and other inflammatory pulmonary diseases.

Spleen tyrosine kinase: a novel target for therapeutic intervention of rheumatoid arthritis

BACKGROUND

In the last few years, significant progress has been made in understanding the pathogenic mechanisms and in defining the role of relevant cells and molecules in the pathophysiology of rheumatoid arthritis (RA). Various therapies, both biological (anti-TNF, anti-interleukins [e.g., IL-1]) and small molecule inhibitors have been explored for the treatment of RA.

OBJECTIVE

To date, no single signaling pathway inhibitor as wide acting as the corticosteroids, is known. However, treatment with corticosteroids is also associated with allied side effects. Despite a lot of efforts in the category of small molecule inhibitors, no inhibitor is available to deal with RA at both fronts (inflammation and tissue damage), without causing immense side effects.

METHOD

This present review explores the role of spleen tyrosine kinase (Syk) in the pathogenesis of RA and also discusses how it may meet the present day therapeutic requirements for the treatment of RA. This review gives an in-depth discussion on the role of Syk signaling in RA, the possibilities of using Syk as a target and also discusses the possible side effects that could be associated with its inhibition.

CONCLUSION

We propose Syk inhibition as a potential therapeutic approach for the treatment of RA.

Inflammatory pseudotumor of lymph nodes presenting as pyrexia of unknown origin

Inflammatory pseudotumor (IPT) is an uncommon benign disorder characterized by proliferation of spindle cells, inflammatory cells, and small vessels. The IPT of lymph nodes is a rare cause of lymphadenopathy that usually affects one or two nodal groups. We describe a 27-year-old male presenting with generalized lymphadenopathy, hepatosplenomegaly and fever for 1 year. Histologic examination of lymph node revealed few remnant lymphoid aggregates with marked sclerosis and numerous anastomosing blood vessels in lymph node parenchyma. Interspersed in between the fibrotic bands was a polymorphic infiltrate composed of lymphocytes, plasma cells, eosinophils, and immunoblasts. Also, many histiocytes, multinucleated giant cells some being Langhan's type and at places forming ill-defined granulomas were observed. The presence of granulomas and Langhan's type of giant cells can lead to a misdiagnosis of tuberculosis as was also done in the present case. It is thus not only important to be aware of this rare benign pathologic entity while dealing with a case of lymphadenopathy, but also consider it in the differential diagnosis of granulomatous disease.

Pathology and pathogenesis of rheumatic heart disease

Cardiovascular disease is on the rise. In India and other developing countries, rheumatic heart disease (RHD) continues to be a major public health problem and contributes to significant cardiac morbidity and mortality. RHD in the juvenile age group namely juvenile mitral stenosis is a variant which is unique to the Indian subcontinent. Severe valve deformities lead to high morbidity and mortality. Despite various measures no appreciable decline in prevalence of RHD has been documented. At autopsy, mitral valve was most commonly affected either alone or in combination with aortic and tricuspid valves. Both functional and organic involvement of tricuspid valve was documented. It has been convincingly demonstrated that molecular mimicry between Streptococcus pyogenes antigen and human proteins lead to autoimmune reactions both humoral and cell mediated causing RF/RHD. Heart tissues namely the valves, left atrial appendage (LAA) and myocardium reveal variable amounts of infiltration by lymphocytes. Significant endocarditis and valvulitis is observed in these cases. CD4+ T cells are most likely the ultimate effectors of chronic valve lesions in RHD. They can recognize Streptococcal M5 protein peptides and produce various inflammatory cytokines such as TNF-alpha, IFN-gamma, IL-10, IL-4 which could be responsible for progressive fibrotic valvular lesions. Cardiac myosin has been defined as a putative autoantigen recognized by autoantibodies of RF patients. Cross reactivity between cardiac myosin and group A beta hemolytic Streptococcal M protein has been adequately demonstrated. Cardiac myosin has been shown to produce myocarditis in rats and mice. Valvulitis/ endocarditis has been observed in excised LAA, cardiac valves and in hearts at autopsy from cases of RHD. The disease predominantly affects the valvular endocardium culminating in crippling valve deformities. Endocardial infiltrate and their migration into the valve substance has been elegantly demonstrated in rats and mice. Immune responses against cardiac myosin lead to valvular heart disease and infiltration of the heart by Streptococcal M protein reactive T lymphocytes. Mitral valves showed various degrees of calcification. An interesting observation is the nature of calcification in diseased/distorted valves in RHD. Recent studies indicate that calcification is not merely an inactive, "dystrophic" process but involves a regulated inflammatory process associated with expression of osteoblast markers and neoangiogenesis. Increased plasma osteopontin levels correlated with severity of mitral valve calcification. Further evidence of inflammation is supported by high levels of advanced oxidation protein products and high sensitive C-reactive protein in plasma detected in patients with RHD. Presence of inflammatory cells and increased expression of several cytokines in cases of "end stage" RHD reflects a possible subclinical, ongoing insult/injury to some unrecognized antigenic stimulus by beta hemolytic Streptococcal antigens that have sensitized/primed the various target tissues and which further culminate in permanent valve deformities.

Bacteriological evaluation of conjunctiva, contact lens storage cases and solutions during contact lens wear

A total of 90 subjects were investigated in this study, out of which 51 constituted the contact lens wearing group and 39 constituted the control group who had never worn contact lenses. Out of 51 contact lens wearing group, 41 were asymptomatic lens wearer subjects and 10 were symptomatic lens wearer subjects having some complications. All the subjects of contact lens wearing group had worn soft contact lenses on daily wear basis for a duration of 7 days to one year. In total 33 subjects were culture positive and remaining 57 culture negative. Staphylococcus epidermidis was isolated equally from asymptomatic and control group, however, significantly more gram negative organisms such as Pseudomonas aeruginosa and Serratia marcescens were isolated from the symptomatic lens wearers. P. aeruginosa and S. marcescens could also be isolated from lens storage cases. S. marcescens was the organism most commonly isolated from the contact lens solutions. Further, the results showed that both P. aeruginosa and S. marcescens adhere to injured cornea only and not to normal cornea when microscopic study of adherence of bacteria to uninjured and injured ex vivo mouse corneas was done.

Efficacy of Valganciclovir in the Treatment of Cytomegalovirus Disease in Kidney and Pancreas Transplant Recipients

Cytomegalovirus (CMV) disease is relatively common following solid organ transplant, particularly if a serologically negative recipient receives an organ from a serologically positive donor (D+/R-). Although valganciclovir is approved for the treatment of CMV retinitis in AIDS patients and is used for the prophylaxis against CMV infection in solid organ transplant patients, the current standard treatment for CMV disease in solid organ transplant recipients remains intravenous ganciclovir. We retrospectively reviewed our experience using valganciclovir as treatment for CMV disease in CMV D+/R- kidney and/or pancreas transplant recipients from March 2002 to June 2005. A total of 37 cases with primary CMV disease were diagnosed and treated with either intravenous ganciclovir as induction followed with valganciclovir or valganciclovir from the beginning. We compared clinical outcomes and viremia between the two groups. Our data suggest that valganciclovir is an effective treatment modality for primary CMV disease in kidney and/or pancreas transplant recipients. It led to the resolution of disease and undetectable viremia. Valganciclovir allowed for early initiation of treatment and for treatment to be given as an outpatient. These advantages of valganciclovir have both health and economic impact for patients with CMV disease.

Role of Mycobacterium tuberculosis Ser/Thr kinase PknF: implications in glucose transport and cell division

Protein kinases have a diverse array of functions in bacterial physiology, with a distinct role in the regulation of development, stress responses, and pathogenicity. pknF, one of the 11 kinases of Mycobacterium tuberculosis, encodes an autophosphorylating, transmembrane serine/threonine protein kinase, which is absent in the fast-growing, nonpathogenic Mycobacterium smegmatis. Herein, we investigate the physiological role of PknF using an antisense strategy with M. tuberculosis and expressing PknF and its kinase mutant (K41M) in M. smegmatis. Expression of PknF in M. smegmatis led to reduction in the growth rate and shortening and swelling of cells with constrictions. Interestingly, an antisense strain of M. tuberculosis expressing a low level of PknF displayed fast growth and a deformed cell morphology compared to the wild-type strain. Electron microscopy showed that most of the cells of the antisense strain were of a smaller size with an aberrant septum. Furthermore, nutrient transport analysis of these strains was conducted using 3H-labeled and 14C-labeled substrates. A significant increase in the uptake of D-glucose but not of glycerol, leucine, or oleic acid was observed in the antisense strain compared to the wild-type strain. The results suggest that PknF plays a direct/indirect role in the regulation of glucose transport, cell growth, and septum formation in M. tuberculosis.

Nucleoside diphosphate kinase from Mycobacterium tuberculosis cleaves single strand DNA within the human c-myc promoter in an enzyme-catalyzed reaction

The reason for secretion of nucleoside diphosphate kinase (NdK), an enzyme involved in maintaining the cellular pool of nucleoside triphosphates in both prokaryotes and eukaryotes, by Mycobacterium tuberculosis is intriguing. We recently observed that NdK from M.tuberculosis (mNdK) localizes within nuclei of HeLa and COS-1 cells and also nicks chromosomal DNA in situ (A. K. Saini, K. Maithal, P. Chand, S. Chowdhury, R. Vohra, A. Goyal, G. P. Dubey, P. Chopra, R. Chandra, A. K. Tyagi, Y. Singh and V. Tandon (2004) J. Biol. Chem., 279, 50142–50149). In the current study, using a molecular beacon approach, we demonstrate that the mNdK catalyzes the cleavage of single strand DNA. It displays Michaelis–Menten kinetics with a k_cat/K_M of 9.65 (±0.88) × 10⁶ M⁻¹ s⁻¹. High affinity (K_d ≈ K_M of ∼66 nM) and sequence-specific binding to the sense strand of the nuclease hypersensitive region in the c-myc promoter was observed. This is the first study demonstrating that the cleavage reaction is also enzyme-catalyzed in addition to the enzymatic kinase activity of multifunctional NdK. Using our approach, we demonstrate that GDP competitively inhibits the nuclease activity with a K_I of ∼1.9 mM. Recent evidence implicates mNdK as a potent virulence factor in tuberculosis owing to its DNase-like activity. In this context, our results demonstrate a molecular mechanism that could be the basis for assessing in situ DNA damage by secretory mNdK.

Recent advances towards identification of new drug targets for Mycobacterium tuberculosis

Mycobacterium tuberculosis is a very successful pathogen that remains a leading infectious killer worldwide. The global situation has become precarious due to various factors such as the variable efficacy of the Bacille Calmette-Guerin (BCG) vaccine, drug resistance, delay in diagnosis, association with HIV, and other factors, creating a long-lasting reservoir of impending disease and infection. Surprisingly, no new drugs have been developed in the past 30 years. The release of the complete genome sequence of M. tuberculosis and the availability of advanced genetic tools have provided the powerful repertoire of potential drug targets that are now in hand and can be explored in a more rational and directional manner. In this review, the authors highlight some possible therapeutic targets in M. tuberculosis. The gene products involved in various processes, such as mycobacterial cell wall synthesis, ability to acquire or obtain essential nutrients, persistence, transcription regulation, energy metabolism and others, such as the PE-PGRS family and culture filtrate proteins, would be potential targets for the development of new drugs. Apart from these categories, the importance of signal transduction events in the virulence of mycobacteria is discussed in relation to their potential as therapeutic targets. The potential of all of these therapeutic targets should be investigated together with the potential of being able to synthesise future chemotherapeutic agents.

Suture Foreign Body Granuloma Masquerading as Renal Neoplasm

Foreign body granulomas and pseudotumors due to retained surgical linen are well known in surgical practice. These lesions usually correspond to the actual size of residual foreign body and have characteristic presentation according to the anatomy involved. Renal suture granuloma is a rare postoperative complication of renal surgery due to persistence of sutures used to close the pelvicalyceal system/nephrotomy incisions and usually present as incidentally detected small mass lesions. This case of a suture foreign body granuloma presenting with hematuria, large peripheral mass lesion and characteristic computed tomography picture of renal cell carcinoma confounded the diagnosis and underwent laparoscopic radical nephrectomy. In retrospect, such lesions warrant the use of selective needle biopsy and intraoperative frozen section confirmation to clinch diagnosis. Mass lesions occurring in a previously operated kidney should have granuloma as a differential diagnosis.

An experimental design for induction of non-specific aortoarteritis

BACKGROUND

An attempt was made to induce aortoarteritis in mice by using various antigens.

METHODS AND RESULTS

The Swiss mice were immunized with eight different antigens and were grouped A to G. Group H served as control. The mice were then bled at 1st, 2nd, 4th, 6th and 8th month interval post-immunization for estimating antibody titer. Then the mice were sacrificed and the heart, aorta and kidney were taken out and processed for hematoxylin-eosin staining. There was gradual increase in the antibody titer from 1st month till 4th month within all the experimental groups (A-G), when compared with control group H. The titer started falling sharply from 6th month post-immunization. However, the control group H did not show much variation. When each individual group was compared separately with control group H, the significant statistical value was obtained. Histopathological examination revealed mild inflammation (+) in kidney by 2nd month, moderate inflammation (++) by 6th month, extensive inflammation (+++) by 8th month and alteration in the normal parenchyma of kidney by 8th month.

CONCLUSIONS

The histopathological changes brought out through antigens were more pronounced by 8th month following injection of tunica media, tunica adventitia, tunica intima and aorta collagen as compared to that of standard collagen and mouse aorta injections.

Post-kala-azar dermal leishmaniasis: A histopathological study

BACKGROUND

Post-kala-azar dermal leishmaniasis follows an attack of visceral leishmaniasis and is caused by the same organism, i.e. Leishmania donovani.

METHODS

In the present study, biopsy specimens from hypopigmented macules, nodules or plaques of 25 patients clinically diagnosed as PKDL were evaluated for epidermal and dermal changes and for the presence or absence of Leishmania donovani bodies (LDBs).

RESULTS

The hypopigmented macules showed a patchy perivascular and periappendageal infiltrate with no demonstrable LDBs in any of the biopsies. In the nodular and plaque lesions, the infiltrate was diffuse, beneath an atrophic epidermis (74%) and follicular plugging (95.6%) was seen in most biopsies. The infiltrate consisted of lymphocytes, histiocytes and plasma cells in decreasing order of presence. LDBs could be demonstrated in only 10 (43.5%) biopsy specimens from nodular and plaque lesions and were never numerous.

CONCLUSIONS

Histopathological features of PKDL are elucidated and discussed.

Nuclear Localization and in Situ DNA Damage by Mycobacterium tuberculosis Nucleoside-diphosphate Kinase

Nucleoside-diphosphate kinase of Mycobacterium tuberculosis (mNdK) is a secretory protein, but the rationale behind secreting an enzyme involved in the maintenance of cellular pool of nucleoside triphosphates is not clearly understood. To elucidate the biological significance of mNdK secretion, we expressed mNdK fused to green fluorescent protein in HeLa and COS-1 cells. Interestingly, mNdK was detected in the nuclei of HeLa and COS-1 cells. Incubation of mNdK with nuclei isolated from HeLa and COS-1 cells led to in situ damage of chromosomal DNA. Surface plasmon resonance studies demonstrated that mNdK binds supercoiled plasmid DNA lacking apurinic/apyrimidinic sites with a dissociation constant of 30 +/- 3.2 mum. Plasmid cleavage by mNdK was found to be dependent on the specific divalent metal ion and inhibited by a metal ion chelator. Moreover, the metal ion-dependent DNA cleavage by mNdK was mediated by superoxide radicals as detected by electron paramagnetic resonance. The cleavage reaction was inhibited under nitrogen atmosphere confirming the necessity of molecular oxygen for DNA cleavage. In view of the findings that mNdK is secreted by intracellular mycobacteria and damages the nuclear DNA, it can be postulated that mNdK may cause cell death that could help in the dissemination of the pathogen.

Nucleoside diphosphate kinase of Mycobacterium tuberculosis acts as GTPase-activating protein for Rho-GTPases

Several bacterial pathogens secrete proteins into the host cells that act as GTPase-activating proteins (GAPs) for Rho-GTPases and convert GTP-bound active form to GDP-bound inactive form. However, no such effector molecule has been identified in Mycobacterium tuberculosis. In this study, we show that culture supernatant of M. tuberculosis H(37)Rv harbors a protein that stimulates the conversion of GTP-bound Rho-GTPases to the GDP-bound form. Nucleoside diphosphate kinase (Ndk) was identified as this culture supernatant protein that stimulated in vitro GTP hydrolysis by members of Rho-GTPases. The histidine-117 mutant of Ndk, which is impaired for autophosphorylation and nucleotide-binding activities, shows GAP activity. These results suggest that Ndk of M. tuberculosis functions as a Rho-GAP to downregulate Rho-GTPases, and this activity may aid in pathogenesis of the bacteria.

Mucosal and peri-orificial involvement in post-kala-azar dermal leishmaniasis

BACKGROUND AND AIMS

Lesions of post-kala-azar dermal leishmaniasis (PKDL) usually affect the skin. Uncommonly, the involvement of oral and genital mucosae has been reported.

METHODS

Twenty five patients clinically diagnosed as post-kala-azar dermal leishmaniasis were studied for periorificial and mucosal lesions. Clinical examination, skin smears and biopsy were done for the patients with periorificial or mucosal lesions.

RESULTS

Out of 25 patients of PKDL, seven patients had lesions on the oral and/or genital mucosa. Three cases had oral lesions; two had only genital lesions and three patients had both sites involved. All the patients were having skin lesions elsewhere too either as nodules and/or plaque or macules.

CONCLUSION

While examining a case of PKDL, mucosal involvement must also be examined carefully.

PknH, a transmembrane Hank's type serine/threonine kinase from Mycobacterium tuberculosis is differentially expressed under stress conditions

Serine/threonine protein kinases (STPKs) represent a burgeoning concept in prokaryotic signaling and have been implicated in a range of control mechanisms. This paper describes the enzymatic and molecular characterization of PknH, a mycobacterial STPK. After cloning and expression as a Glutathione-S-transferase fusion protein in E. coli, PknH was found to phosphorylate itself and exogenous substrates like myelin basic protein and histone. The kinase activity of PknH was inhibited by the kinase inhibitors staurosporine and H-7. The results confirmed that PknH is a transmembrane protein and is restricted to members of the Mycobacterium tuberculosis complex. In addition, transcriptional analysis of pknH in M. tuberculosis under various stress conditions revealed that exposure to low pH and heat shock decreased the level of pknH transcription significantly. This is the first report describing differential expression of a mycobacterial kinase in response to stress conditions which can indicate its ability to regulate cellular events promoting bacterial adaptation to environmental change.

Phosphoprotein phosphatase of Mycobacterium tuberculosis dephosphorylates serine-threonine kinases PknA and PknB

The regulation of cellular processes by the modulation of protein phosphorylation/dephosphorylation is fundamental to a large number of processes in living organisms. These processes are carried out by specific protein kinases and phosphatases. In this study, a previously uncharacterized gene (Rv0018c) of Mycobacterium tuberculosis, designated as mycobacterial Ser/Thr phosphatase (mstp), was cloned, expressed in Escherichia coli, and purified as a histidine-tagged protein. Purified protein (Mstp) dephosphorylated the phosphorylated Ser/Thr residues of myelin basic protein (MBP), histone, and casein but failed to dephosphorylate phospho-tyrosine residue of these substrates, suggesting that this phosphatase is specific for Ser/Thr residues. It has been suggested that mstp is a part of a gene cluster that also includes two Ser/Thr kinases pknA and pknB. We show that Mstp is a trans-membrane protein that dephosphorylates phosphorylated PknA and PknB. Southern blot analysis revealed that mstp is absent in the fast growing saprophytes Mycobacterium smegmatis and Mycobacterium fortuitum. PknA has been shown, whereas PknB has been proposed to play a role in cell division. The presence of mstp in slow growing mycobacterial species, its trans-membrane localization, and ability to dephosphorylate phosphorylated PknA and PknB implicates that Mstp may play a role in regulating cell division in M. tuberculosis.

Therapeutic trial of sodium antimony gluconate alone and in combination with ketoconazole in post-kala-azar dermal leishmaniasis

BACKGROUND

Drugs used in PKDL include parenteral sodium antimony gluconate (SAG), amphotericin-B, pentamidine, and ketoconazole (KTZ). SAG is the most effective one. Given alone, SAG has to be given for a long duration, leading to poor patient compliance and treatment failure. This study was carried out to compare the effectiveness of SAG alone and a combination of SAG and KTZ for sixty days.

METHODS

Ten patients of PKDL were included in the study. Five patients (Group A) were given SAG intravenously, in the dose of 20 mg/kg per day and five (Group B) were given SAG (intravenously 20 mg/kg per day) and KTZ (200 mg twice daily orally). Both treatment regimens were given for sixty days.

RESULTS

In Group A, the nodules and/or plaques showed approximate 80-85% clinical improvement, and macules showed 25-30% improvement. In group B (SAG + KTZ), there was 90-95% clinical improvement in the nodules and/or plaques and 25-30% in macules.

CONCLUSION

This study suggests the therapeutic superiority of the combination treatment regimen in a shorter duration but is not conclusive as the number of patients was low. Further trials are recommended.

Nucleoside diphosphate kinase-like activity in adenylate kinase of Mycobacterium tuberculosis

Ak (adenylate kinase) is a ubiquitous enzyme that catalyses a reversible high-energy phosphoryl-transfer reaction between ATP and AMP to form ADP. In the present study, the Ak gene (adk) of Mycobacterium tuberculosis was cloned, expressed in Escherichia coli and purified as a glutathione S-transferase fusion protein. Purified Ak converted AMP into ADP in the presence of [gamma-32P]ATP or [gamma-32P]GTP. Replacement of arginine-88 of adk with glycine resulted in the loss of enzymic activity. The purified protein also showed Ndk (nucleoside diphosphate kinase)-like activity as it transferred terminal phosphate from [gamma-32P]ATP to all nucleoside diphosphates, converting them into corresponding triphosphates. However, Ndk-like activity of Ak was not observed with [gamma-32P]GTP. Immunoblot analysis of various cellular fractions of M. tuberculosis H37Rv revealed that Ak is a cytoplasmic protein. The dual activity of Ak as both nucleoside mono- and di-phosphate kinases suggested that this enzyme may have a role in RNA and DNA biosynthesis in addition to its role in intracellular nucleotide metabolism.

Cardiac myxoma with glandular elements: a histologic, histochemical, and immunohistochemical evaluation

Epithelial differentiation in cardiac myxoma is a rare phenomenon. Out of 104 surgically excised specimens, we studied 3 cases of cardiac myxoma with glandular differentiation. All the cases had well formed glands in addition to the myxoma cells lying in a myxoid background. Detailed histochemical and immunohistochemical studies suggest that the epithelial islands in cardiac myxoma show an enteric phenotype.

Cytotoxic activity of nucleoside diphosphate kinase secreted from Mycobacterium tuberculosis

Pathogenicity of Mycobacterium tuberculosis is closely related to its ability to survive and replicate in the hostile environment of macrophages. For some pathogenic bacteria, secretion of ATP-utilizing enzymes into the extracellular environment aids in pathogen survival via P2Z receptor-mediated, ATP-induced death of infected macrophages. A component of these enzymes is nucleoside diphosphate kinase (Ndk). The ndk gene was cloned from M. tuberculosis H37Rv and expressed in Escherichia coli. Ndk was secreted into the culture medium by M. tuberculosis, as determined by enzymatic activity and Western blotting. Purified Ndk enhanced ATP-induced macrophage cell death, as assayed by the release of [14C]adenine. A catalytic mutant of Ndk failed to enhance ATP-induced macrophage cell death, and periodate-oxidized ATP (oATP), an irreversible inhibitor of P2Z receptor, blocked ATP/Ndk-induced cell death. Purified Ndk was also found to be autophosphorylated with broad specificity for all nucleotides. Conversion of His117-->Gln, which is part of the nucleotide-binding site, abolished autophosphorylation. Purified Ndk also showed GTPase activity. Collectively, these results indicate that secreted Ndk of M. tuberculosis acts as a cytotoxic factor for macrophages, which may help in dissemination of the bacilli and evasion of the immune system.

New drug targets for Mycobacterium tuberculosis

In spite of the availability of effective chemotherapy and Bacille-Calmette-Guerin (BCG) vaccine, tuberculosis remains a leading infectious killer world-wide. Many factors such as, human immunodeficiency virus (HIV) co-infection, drug resistance, lack of patient compliance with chemotherapy, delay in diagnosis, variable efficacy of BCG vaccine and various other factors contribute to the mortality due to tuberculosis. In spite of the new advances in understanding the biology of Mycobacterium tuberculosis, and availability of functional genomic tools, such as microarray and proteomics, in combination with modern approaches, no new drug has been developed in the past 30 yr. Therefore, there is an urgent need to identify new drug targets in mycobacteria and eventually, develop new drugs. The release of the complete genome sequence of M. tuberculosis has facilitated a more rational, and directional approach to search for new drug targets. In general, gene products involved in mycobacterial metabolism, persistence, transcription, cell wall synthesis and virulence would be possible targets for the development of new drugs. The exploitation of host cell signaling pathways for the benefit of the pathogen is a phenomenon that deserves to be looked into with a new perspective in the current scenario to combat M. tuberculosis. Reversible phosphorylation and dephosphorylation, which are carried out by specific protein kinases and phosphatases have been shown to modify the host proteins and help in the establishment of disease by several pathogenic bacteria. In this review, we discuss some possible drug targets for M. tuberculosis.

Primary care work-up of acute and chronic symptoms

Low back pain may present as acute pain or as an acute exacerbation of a chronic pain problem. Acute low back pain is self-limited, with 90% of affected individuals recovering within 3 weeks to 3 months. Pain duration of more than 4 weeks warrants a more complete work-up, including ruling out malignancy. Pain duration of more than 6 months defines chronic pain, which is frequently associated with affective and behavioral components. When taking the history, determine pain intensity, location, pattern of radiation, onset, and duration. A gentle physical exam may help locate the source of pain through palpation and maneuvers, such as the straight leg raise test. Imaging is recommended for patients with a clinical finding that raises suspicion of spinal malignancy.