Bioisosteric modification of Linezolid identified the potential M. tuberculosis protein synthesis inhibitors to overcome the myelosuppression and serotonergic toxicity associated with Linezolid in the treatment of the multi-drug resistance tuberculosis (MDR-TB)

Linezolid is the first and only oxazolidinone antibacterial drug was approved in the last 35 years. It exhibits bacteriostatic efficacy against M. tuberculosis and is a crucial constituent of the BPaL regimen (Bedaquiline, Pretomanid, and Linezolid), which was authorized by the FDA in 2019 for the treatment of XDR-TB or MDR-TB. Despite its unique mechanism of action, Linezolid carries a considerable risk of toxicity, including myelosuppression and serotonin syndrome (SS), which is caused by inhibition of mitochondrial protein synthesis (MPS) and monoamine oxidase (MAO), respectively. Based on the structure toxicity relationship (STR) of Linezolid, in this work, we used a bioisosteric replacement approach to optimize the structure of Linezolid at the C-ring and/or C-5 position for myelosuppression and serotogenic toxicity. Extensive hierarchical multistep docking, drug likeness prediction, molecular binding interactions analyses, and toxicity assessment identified three promising compounds (3071, 7549 and 9660) as less toxic potential modulators of Mtb EthR protein. Compounds 3071, 7549 and 9660 were having the significant docking score of -12.696 Kcal/mol, -12.681 Kcal/mol and -15.293 Kcal/mol towards the Mtb EthR protein with less MAO-A and B affinity [compound 3071: MAO A (-4.799 Kcal/mol) and MAO B (-6.552 Kcal/mol); compound 7549: MAO A (> -2.00 Kcal/mol) and MAO B (> -2.00 Kcal/mol) and compound 9660: MAO A (> -5.678 Kcal/mol) and MAO B (> -6.537Kcal/mol) and none of them shown the Leukopenia as a side effect due to the Myelosuppression. The MD simulation results and binding free energy estimations correspond well with docking analyses, indicating that the proposed compounds bind and inhibit the EthR protein more effectively than Linezolid. The quantum mechanical and electrical characteristics were evaluated using density functional theory (DFT), which also demonstrated that the proposed compounds are more reactive than Linezolid.Communicated by Ramaswamy H. Sarma.

Evaluating antibiotic regimens for streptococcal toxic shock syndrome in children

INTRODUCTION

Streptococcal toxic shock syndrome (STSS) is a severe consequence of infections from Streptococcus pyogenes. The early identification and timely intervention with appropriate anti-infective agents are pivotal for managing pediatric STSS. This study evaluates the effectiveness of various treatment regimens for STSS in children.

METHODS

Clinical data of children with STSS resulting from β-hemolytic streptococcal infections in two hospitals were retrospectively analyzed from January 2009 to April 2023. Additionally, literature from the China National Knowledge Infrastructure on pediatric STSS was examined. Antimicrobial treatments were categorized into four groups based on their compositions, with an additional categorization for adjunct therapeutic drugs.

RESULTS

Of 32 confirmed STSS cases, all displayed sensitivity to ampicillin, β-lactam antibiotics, and vancomycin, but resistance to clindamycin, erythromycin, and tetracycline. From the literature, 23 studies with 50 cases were extracted, leading to a total of 82 patients for evaluation. The efficacy rates varied significantly among the four treatment groups. Notably, the standard penicillin-containing group exhibited the highest efficacy (86.4%), while the group with macrolides/unused antibiotics registered a 0% efficacy rate. The other two groups demonstrated efficacy rates of 32.1% and 42.3%.

CONCLUSION

For pediatric STSS, Streptococcus pyogenes shows notable sensitivity to ampicillin. Implementing timely β-lactam antibiotics, specifically penicillin, in conjunction with clindamycin and intravenous immunoglobulins enhances the treatment success rate.

Systematic Review of Hospital Treatment Outcomes for Naturally Acquired and Bioterrorism-Related Anthrax, 1880-2018

BACKGROUND

Bacillus anthracis can cause anthrax and is a potential bioterrorism agent. The 2014 Centers for Disease Control and Prevention recommendations for medical countermeasures against anthrax were based on in vitro data and expert opinion. However, a century of previously uncompiled observational human data that often includes treatment and outcomes is available in the literature for analysis.

METHODS

We reviewed treatment outcomes for patients hospitalized with anthrax. We stratified patients by meningitis status, route of infection, and systemic criteria, then analyzed survival by treatment type, including antimicrobials, antitoxin/antiserum, and steroids. Using logistic regression, we calculated odds ratios and 95% confidence intervals to compare survival between treatments. We also calculated hospital length of stay. Finally, we evaluated antimicrobial postexposure prophylaxis (PEPAbx) using data from a 1970 Russian-language article.

RESULTS

We identified 965 anthrax patients reported from 1880 through 2018. After exclusions, 605 remained: 430 adults, 145 children, and 30 missing age. Survival was low for untreated patients and meningitis patients, regardless of treatment. Most patients with localized cutaneous or nonmeningitis systemic anthrax survived with 1 or more antimicrobials; patients with inhalation anthrax without meningitis fared better with at least 2. Bactericidal antimicrobials were effective for systemic anthrax; addition of a protein synthesis inhibitor(s) (PSI) to a bactericidal antimicrobial(s) did not improve survival. Likewise, addition of antitoxin/antiserum to antimicrobials did not improve survival. Mannitol improved survival for meningitis patients, but steroids did not. PEPAbx reduced risk of anthrax following exposure to B. anthracis.

CONCLUSIONS

Combination therapy appeared to be superior to monotherapy for inhalation anthrax without meningitis. For anthrax meningitis, neither monotherapy nor combination therapy were particularly effective; however, numbers were small. For localized cutaneous anthrax, monotherapy was sufficient. For B. anthracis exposures, PEPAbx was effective.

Sarecycline: A Narrow-Spectrum Antibiotic

Tetracycline-class drugs have been used for first-line treatment of moderate-to-severe acne and rosacea for decades. Recently, a new third generation tetracycline, sarecycline, was US FDA-approved for the treatment of moderate-to-severe acne. This narrow-spectrum tetracycline-derived antibiotic has been shown to be effective with an improved safety profile.

Exploring Drug Treatment Patterns Based on the Action of Drug and Multilayer Network Model

Some drugs can be used to treat multiple diseases, suggesting potential patterns in drug treatment. Determination of drug treatment patterns can improve our understanding of the mechanisms of drug action, enabling drug repurposing. A drug can be associated with a multilayer tissue-specific protein-protein interaction (TSPPI) network for the diseases it is used to treat. Proteins usually interact with other proteins to achieve functions that cause diseases. Hence, studying drug treatment patterns is similar to studying common module structures in multilayer TSPPI networks. Therefore, we propose a network-based model to study the treatment patterns of drugs. The method was designated SDTP (studying drug treatment pattern) and was based on drug effects and a multilayer network model. To demonstrate the application of the SDTP method, we focused on analysis of trichostatin A (TSA) in leukemia, breast cancer, and prostate cancer. We constructed a TSPPI multilayer network and obtained candidate drug-target modules from the network. Gene ontology analysis provided insights into the significance of the drug-target modules and co-expression networks. Finally, two modules were obtained as potential treatment patterns for TSA. Through analysis of the significance, composition, and functions of the selected drug-target modules, we validated the feasibility and rationality of our proposed SDTP method for identifying drug treatment patterns. In summary, our novel approach used a multilayer network model to overcome the shortcomings of single-layer networks and combined the network with information on drug activity. Based on the discovered drug treatment patterns, we can predict the potential diseases that the drug can treat. That is, if a disease-related protein module has a similar structure, then the drug is likely to be a potential drug for the treatment of the disease.

Protein synthesis inhibitors of natural origin for CML therapy: semisynthetic homoharringtonine (Omacetaxine mepesuccinate)

Omacetaxine mepesuccinate is a drug approved in 2014 by FDA for the use in CML therapy in patients resistant to at least two thymidine kinase inhibitors (TKIs). It possesses unique mechanism of anticancer activity that is principally different from mechanism of activity of TKIs. Omacetaxine mepesuccinate inhibits protein translation through prevention of the initial elongation step of protein synthesis and its use benefits CML patients possessing the BCR-ABL oncogene. Because of the superior activity of Omacetaxine in patients who became resistant to therapy with TKIs, FDA decided on the accelerated approval of this drug taking its consideration not only its activity as such but also a favorable benefit-to-risk profile in patients included into clinical studies.

Pseudomonas Exotoxin Immunotoxins and Anti-Tumor Immunity: From Observations at the Patient's Bedside to Evaluation in Preclinical Models

Immunotoxins are protein drugs composed of a targeting domain genetically fused to a protein toxin. One killing domain being explored is a truncated Pseudomonas exotoxin A (PE). PE based immunotoxins are designed to kill cells directly by inhibiting their ability to synthesize proteins. However, observations from clinical trials suggest that this alone cannot explain their anti-tumor activity. Here we discuss patterns of clinical responses suggesting that PE immunotoxins can provoke anti-tumor immunity, and review murine models that further support this ability. In addition, we describe our preclinical effort to develop a combination therapy of local PE immunotoxins with a systemic anti-CTLA-4 immune check point blocking antibody. The combination eradicated murine tumors and prolonged the survival of mice. Clinical trials that test the ability of immunotoxins to augment immunotherapy have been recently opened.

Successful chemical ablation of an intraorbital cyst caused by an eyelid injury and iatrogenic ankyloblepharon formation in a duck

CASE DESCRIPTION A client-owned 2-year-old 1.8-kg (4-lb) male pet Rouen duck (Anas platyrhynchos domesticus) was evaluated because of severe swelling around the left eye following traumatic injury to the upper and lower eyelids and 2 associated surgeries that resulted in the removal of the entire upper and lower eyelid margins. CLINICAL FINDINGS At initial evaluation, ankyloblepharon of the left eye was observed, with no upper or lower eyelid margins and a large, round, fluctuant subcutaneous mass over the left orbit. Orbital exploration and histologic examination revealed a benign cyst consisting of fibrous tissue, conjunctiva, and skeletal muscle bundles. Bacterial culture of cystic fluid yielded few Staphylococcus delphini. TREATMENT AND OUTCOME Excision of the cyst and evisceration of the left globe were performed, and once daily treatment with orally administered enrofloxacin suspension (12.6 mg/kg [5.7 mg/lb]) and meloxicam (1 mg/kg [0.45 mg/lb]) was initiated. Over the next 4 days, the cyst redeveloped and progressively enlarged. Accumulated fluid was aspirated from the cyst, and 20 mg of gentamicin was injected intraorbitally with ultrasound guidance. Over the subsequent 27-month period, no recurrence of clinical signs or adverse effects were reported by the owner. CLINICAL RELEVANCE To the authors' knowledge, this is the first report of cyst formation after adnexal injury and evisceration in birds and its successful treatment with intralesional gentamicin injection. Findings emphasized the importance of preserving lacrimal puncta during adnexal or eye removal surgeries in birds. Intralesional injection of gentamicin with the goal of destroying fluid-producing cells may be a safe and effective way to treat intraorbital cysts in birds and other species, although additional research would be required to confirm this.

The minor gentamicin complex component, X2, is a potent premature stop codon readthrough molecule with therapeutic potential

Nonsense mutations, resulting in a premature stop codon in the open reading frame of mRNAs are responsible for thousands of inherited diseases. Readthrough of premature stop codons by small molecule drugs has emerged as a promising therapeutic approach to treat disorders resulting from premature termination of translation. The aminoglycoside antibiotics are a class of molecule known to promote readthrough at premature termination codons. Gentamicin consists of a mixture of major and minor aminoglycoside components. Here, we investigated the readthrough activities of the individual components and show that each of the four major gentamicin complex components representing 92–99% of the complex each had similar potency and activity to that of the complex itself. In contrast, a minor component (gentamicin X2) was found to be the most potent and active readthrough component in the gentamicin complex. The known oto- and nephrotoxicity associated with aminoglycosides preclude long-term use as readthrough agents. Thus, we evaluated the components of the gentamicin complex as well as the so-called “designer” aminoglycoside, NB124, for in vitro and in vivo safety. In cells, we observed that gentamicin X2 had a safety/readthrough ratio (cytotoxicity/readthrough potency) superior to that of gentamicin, G418 or NB124. In rodents, we observed that gentamicin X2 showed a safety profile that was superior to G418 overall including reduced nephrotoxicity. These results support further investigation of gentamicin X2 as a therapeutic readthrough agent.

Instrumental head impulse test changes after intratympanic gentamicin for unilateral definite Ménière's disease: A systematic review and meta-analysis

OBJECTIVE

To estimate how much could intratympanic gentamicin (ITG) interfere with the vestibular-ocular reflex (VOR) parameters on instrumental head impulse test (HIT), either with scleral search coil or video head impulse test and, eventually, foresee the control of vertigo crisis in unilateral intractable Ménière's disease (MD).

METHODS

A literature search was conducted in PubMed, Scopus, Web of Science and Cochrane search engines. The search terms used were "vestibular ocular reflex", "head impulse test", "gentamicin," and "Meniere's disease". Limitations included text availability to be full text, species to be humans and language to be English. All study types were included. 89 articles were screened identifying four eligible studies were identified. Studies were included after consensus of the authors. Meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data was analysed using Review Manager software.

RESULTS

Instrumental HIT, after ITG for MD, demonstrated, in the treated ear, a decreased gain in the horizontal, posterior and superior semicircular canals (SCC), of 0.36 (0.26; 0.47; 95% CI), 0.35 (0.22; 0.48; 95% CI) and 0.28 (0.21; 0.35; 95% CI), respectively. Gain asymmetry increases between the treated and non-treated ear of 23.78 (7.22; 40.35; 95% CI), 32.01 (12.27; 51.76; 95% CI) and 17.49 (9.99; 24.99; 95% CI), were similarly detected in the horizontal, posterior and superior SCC, respectively. Significantly smaller gain values after the first treatment were observed for a single injection group versus multiple injection group in the horizontal (p=0.002) and superior SCCs (p=0.016).

CONCLUSIONS

Instrumental HIT is effective in evaluating the SCC function after ITG for intractable unilateral MD. VOR gain changes in the direction of the treated ear in the three SCC have been clearly registered. An increased reduction of the VOR gain in the horizontal and anterior SCC also seemed to foresee the control of vertigo crisis. Still, after meta-analysis, the small number of patients' data available did not allow to define a treatment end-point value. This review also indicated that further and better-designed studies are warranted.

Management of hepatic encephalopathy in the hospital

Hepatic encephalopathy (HE) develops in up to 50% of patients with cirrhosis and is a feature of decompensated cirrhosis. With the goal of reviewing the evidence for treatment and prevention of overt hepatic encephalopathy, pubmed was searched using search terms hepatic encephalopathy AND treatment, limited to human studies from January 1, 2003, through December 1, 2013, and supplemented by key references. The inpatient incidence of HE is approximately 23,000 annually, and management of these patients is common for internists and subspecialists. Treatment of the hospitalized patient with HE has changed in recent years. Treatment entails 2 phases: induction and maintenance of remission. Most cases of significant HE are precipitated by infection, gastrointestinal bleeding, medications, or other culprits. All patients should be evaluated for secondary triggers of HE, and treatment should be initiated with a nonabsorbable disaccharide (ie, lactulose) in most patients. Rifaximin (off label) can be added in patients not responding to lactulose. Neomycin is a less preferred alternative to rifaximin owing to its adverse effect profile. Other therapies, including zinc, L-ornithine-L-aspartate, and branched-chain amino acids, can be considered for patients not responding to disaccharides and nonabsorbable antibiotics. Large portosystemic shunts may be embolized in patients with medically refractory recurrent or severe HE with otherwise well-compensated cirrhosis. Molecular Adsorbent Recirculating System is now available for patients with severe HE who do not respond to medical therapy. It is critically important that patients hospitalized with significant HE continue maintenance therapy at the time of dismissal to prevent further episodes. Patients with a first-time episode of HE can be administered lactulose, and careful instructions should be provided to patients and caregivers about dose titration to achieve 3 bowel movements daily. Patients with recurrent HE episodes despite lactulose use benefit from the addition of rifaximin, which decreases the frequency of recurrent HE episodes and related hospitalizations. Last, patients and their families should be counseled about the risk of motor vehicle accidents, which require mandatory reporting to the Department of Motor Vehicles in some states.

[Staphylococcus aureus and antibiotic resistance]

After the report of first case of methicillin-resistant Staphylococcus aureus (MRSA) in 1961, MRSA become a major problem worldwide. Over the last decade MRSA strains have emerged as serious pathogens in nosocomial and community settings. Glycopeptides (vancomycin and teicoplanin) are still the current mainstay of therapy for infections caused by MRSA. In the last decade dramatic changes have occurred in the epidemiology of MRSA infections. The isolates with reduced susceptibility and in vitro resistance to vancomycin have emerged. Recently, therapeutic alternatives such as quinupristin/dalfopristin, linezolid, tigecycline and daptomycin have been introduced into clinical practice for treating MRSA infections. Nevertheless, these drugs are only approved for certain indication and resistance has already been reported. In this review, the new information on novel drugs for treating MRSA infections and the resistance mechanisms of these drugs were discussed.

Management of suppurative cervical lymphadenitis in a healthy 24-year-old man

Unilateral suppurative cervical lymphadenitis is characterized by acute onset of 1 or more tender cervical lymph nodes and can lead to fever, cellulitis, abscess formation, and bacteremia. This form of lymphadenitis is usually caused by gram-positive bacteria. The present case details the treatment of a previously healthy 24-year-old man who presented with an acutely inflamed cervical lymph node. The patient did not respond to antibiotic monotherapy or combination antibiotics but recovered rapidly after methylprednisolone and osteopathic manipulative treatment were added to his care.

[In vitro induction of transmissive resistance to tetracycline, chloramphenicol and ampicillin chloramphenicol in Vibrio cholera non-O1/non-O139 serogroups isolated within 1990-2005]

Inducible character of resistance to tetracycline, chloramphenicol and ampicillin was investigated in 20 strains of Vibrio cholera non-O1/non-O139 serogroups isolated from inhabitants of Uzbekistan in 1990 (10 strains, ctx+) and in 2001 (5 strains, ctx-) and from inhabitants of Kalmykiya within 2003-2005 (5 strains, ctx-). Eight of the 20 isolates showed not only capacity for induction of the antibiotic resistance, but also its possible self transfer to Escherichia coli and reverse crosses in El Tor V. cholerae P-5879. It was shown that the effect of the antibacterial on the isolates phenotypic susceptibility could increase the resistance markers expression, when the genomes contained sites responsible for their expression, that required constant bacteriological control of the treatment efficacy and the use of the isolates antibioticograms for early replace of the inefficient drug by the efficient one. The prevalence of V. cholerae O1 and non-O1/non-O13 serogroups with multiple resistance to the antibacterial and the genetic potency for the antibiotic resistance development in the pathogen made difficult the choice of efficient drugs for prophylaxis and treatment of diseases caused by V. cholerae.

The effect of gentamicin-induced readthrough on a novel premature termination codon of CD18 leukocyte adhesion deficiency patients

Background

Leukocyte adhesion deficiency 1 (LAD1) is an inherited disorder of neutrophil function. Nonsense mutations in the affected CD18 (ITB2) gene have rarely been described. In other genes containing such mutations, treatments with aminoglycoside types of antibiotics (e.g., gentamicin) were reported to partially correct the premature protein termination, by induction of readthrough mechanism.

Methodology/Principal Findings

Genetic analysis was performed on 2 LAD1 patients. Expression, functional and immunofluorescence assays of CD18 in the patients were used to determine the in-vivo and in-vitro effects of gentamicin-induced readthrough. A theoretical modeling of the corrected CD18 protein was developed to predict the protein function.

Results

We found a novel premature termination codon, C562T (R188X), in exon 6 of the CD18 gene that caused a severe LAD1 phenotype in two unrelated Palestinian children. In-vivo studies on these patients' cells after gentamicin treatment showed abnormal adhesion and chemotactic functions, while in-vitro studies showed mislocalization of the corrected protein to the cytoplasm and not to the cell surface. A theoretical modeling of the corrected CD18 protein suggested that the replacement of the wild type arginine by gentamicin induced tryptophan at the position of the nonsense mutation, although enabled the expression of the entire CD18 protein, this was not sufficient to stabilize the CD18/11 heterodimer at the cell surface.

Conclusion

A novel nonsense mutation in the CD18 gene causing a complete absence of CD18 protein and severe LAD1 clinical phenotype is reported. Both in vivo and in vitro treatments with gentamicin resulted in the expression of a corrected full-length dysfunctional or mislocalized CD18 protein. However, while the use of gentamicin increased the expression of CD18, it did not improve leukocyte adhesion and chemotaxis. Moreover, the integrity of the CD18/CD11 complex at the cell surface was impaired, due to abnormal CD18 protein and possibly lack of CD11a expression.

Ecthyma gangrenosum mimicking acute invasive fungal sinusitis in an immunocompromised patient

Ecthyma gangrenosum is a rare necrotizing cutaneous infection usually caused by Pseudomonas aeruginosa. We report a case of ecthyma gangrenosum presenting as a sinonasal eschar and mimicking acute invasive fungal sinusitis in an immunocompromised 39-year-old man with a hematologic malignancy. To the best of our knowledge, this represents the first case of ecthyma gangrenosum affecting the sinonasal mucosa to be reported in the literature.

Tetracycline treatment retards the onset and slows the progression of diabetes in human amylin/islet amyloid polypeptide transgenic mice

OBJECTIVE

Aggregation of human amylin/islet amyloid polypeptide (hA/hIAPP) into small soluble beta-sheet-containing oligomers is linked to islet beta-cell degeneration and the pathogenesis of type 2 diabetes. Here, we used tetracycline, which modifies hA/hIAPP oligomerization, to probe mechanisms whereby hA/hIAPP causes diabetes in hemizygous hA/hIAPP-transgenic mice.

RESEARCH DESIGN AND METHODS

We chronically treated hemizygous hA/hIAPP transgenic mice with oral tetracycline to determine its effects on rates of diabetes initiation, progression, and survival.

RESULTS

Homozygous mice developed severe spontaneous diabetes due to islet beta-cell loss. Hemizygous transgenic animals also developed spontaneous diabetes, although severity was less and progression rates slower. Pathogenesis was characterized by initial islet beta-cell dysfunction followed by progressive beta-cell loss. Islet amyloid was absent from hemizygous animals with early-onset diabetes and correlated positively with longevity. Some long-lived nondiabetic hemizygous animals also had large islet-amyloid areas, showing that amyloid itself was not intrinsically cytotoxic. Administration of tetracycline dose-dependently ameliorated hyperglycemia and polydipsia, delayed rates of diabetes initiation and progression, and increased longevity compared with water-treated controls.

CONCLUSIONS

This is the first report to show that treating hA/hIAPP transgenic mice with a modifier of hA/hIAPP misfolding can ameliorate their diabetic phenotype. Fibrillar amyloid was neither necessary nor sufficient to cause diabetes and indeed was positively correlated with longevity therein, whereas early- to mid-stage diabetes was associated with islet beta-cell dysfunction followed by beta-cell loss. Interventions capable of suppressing misfolding in soluble hA/hIAPP oligomers rather than mature fibrils may have potential for treating or preventing type 2 diabetes.

Cardiac tamponade as a rare form of presentation of rheumatic carditis

In this article the authors describe a clinical case of acute rheumatic fever (according to revised Jones criteria, American Heart Association [AHA], 1992) with cardiac tamponade, emphasizing this uncommon presentation. An adolescent patient with a clinical picture of cardiac tamponade was seen in the emergency department. Clinical progression and tests demonstrated rheumatic carditis with an initial manifestation of pericarditis with cardiac tamponade. This report aims to warn physicians about the diagnosis of rheumatic carditis in an unusual clinical presentation, in cases of cardiac tamponade, particularly in school-aged children and adolescents in countries with a high prevalence of rheumatic fever. The literature contains only two documented cases of cardiac tamponade related to acute rheumatic fever, and this case represents a third.

Erlotinib: a pharmacoeconomic review of its use in advanced non-small cell lung cancer

Erlotinib (Tarceva), an oral epidermal growth factor receptor tyrosine kinase inhibitor, is associated with modest improvements in survival in patients with advanced non-small cell lung cancer (NSCLC) who have previously received one or more prior chemotherapy regimens. In a well designed clinical trial in this patient population, median overall survival and progression-free survival were significantly longer in patients receiving erlotinib 150 mg/day than in those receiving placebo. Erlotinib is generally well tolerated, with most adverse events being of mild to moderate severity. A large body of modelled pharmacoeconomic data suggests that second- or third-line erlotinib 150 mg/day is a cost-saving option relative to treatment with the approved second-line intravenous chemotherapies of docetaxel and pemetrexed in patients with advanced NSCLC. In patients who had received at least one prior chemotherapy regimen, erlotinib was predicted to be dominant (i.e. more effective and less costly) or cost saving (i.e. equally effective and less costly) relative to docetaxel or pemetrexed with regard to the cost per QALY or life-year gained in cost-effectiveness analyses. Although the effect of erlotinib on overall survival was generally assumed to be equivalent to that of the chemotherapies, the estimated amount of QALYs gained was slightly greater with erlotinib than with docetaxel. In cost-minimization and national budgetary impact analyses, estimated total direct costs with erlotinib were lower than those with docetaxel and pemetrexed, because of the generally lower drug acquisition, administration and adverse event management costs associated with erlotinib. Cost advantages with erlotinib were predicted across analyses, regardless of the type of model developed, specific costs that were included, country that the study was conducted in and year of costing. Sensitivity analyses consistently showed that these results were robust to plausible changes in the key model assumptions. In conclusion, in patients with advanced NSCLC, second- or third-line treatment with erlotinib is clinically effective in improving survival. Available pharmacoeconomic data from several countries, despite some inherent limitations, support the use of erlotinib as a cost-saving treatment relative to chemotherapy with docetaxel or pemetrexed in this patient population.

Antibiotics in odontogenic infection

Antibiotics work by exploiting differences between human and bacterial cells. They are grouped according to their targets of action: cell wall synthesis, protein synthesis, and nucleic acid replication. Generally they should be used as an adjunct to local measures that aim to remove the source of infection and drain pus, usually when infection has spread to adjacent tissue spaces. They should not be used prophylactically after surgical extractions unless significant pre-existing infection is diagnosed.

Identification of candidate drugs for the treatment of ALS

A consortium of investigators interested in neurodegenerative diseases collaborated to screen 1040 drugs in multiple neurodegenerative disease assays. One model of amyotrophic lateral sclerosis (ALS) pathogenesis in particular incorporated glutamate exposure in enriched primary rat motor neuron cultures. In this model 78 compounds decreased motor neuron death caused by 100 microM glutamate. Almost all these pharmacological agents act at one or more of the following cellular targets: 1) protein synthesis inhibition; 2) Cox inhibition; 3) regulation of anion flux; 4) modulation of GABA receptors; 5) antioxidant, and 6) cell cycle inhibition. The most prevalent mode of action was the regulation of intracellular calcium. These data extend the understanding of motor neuron degeneration and identify a number of cellular targets for the improvement of combined therapies for neurodegenerative disease.

Tetracycline therapy for muscle atrophy due to immobilization

Certain proteins such as matrix metalloproteinase -2(MMP-2) and heat shock protein 70(HSP-70) play a role during the degradation process. We hypothesized that tetracycline can be used to reduce tissue degradation in skeletal muscles exposed to immobilization. The right knee of old rats (20-months-old) was immobilized by a rigid external fixator (EF) device for 1, 2, 3 and 4 weeks. Aqueous Tetracycline solution was administrated 3 times a week, following 2 days after the EF was constructed. Control group I was immobilized for 3 weeks, did not receive tetracycline but did received saline injection, and control group II only received tetracycline for 3 weeks. MMP-2 and HSP-70 protein and mRNA levels in the gastrocnemius and soleus muscles were analyzed at the molecular level by RT-PCR and the protein level using SDS-PAGE gels and western blots. We have shown that rats treated by Tetracycline reduce the MMP-2 expression and HSP-70. Theses changes mainly occurred in type IIb and type IIa muscle fibers. Tetracycline administration has beneficial effect on expression of enzymes involved in protein degradation. This may suggest a protective effect on protein degradation during immobilization.

Multifocal skeletal tuberculosis in children

Multifocal bone involvement is though rare but is reported from some countries where tuberculosis is endemic. Here we report a case of three years old boy was admitted in Bangabandhu Sheikh Mujib Medical University, Dhaka with the complaints of difficulty in walking ,low grade fever for six months, swelling over the back, elbow joint, knee joint and upper part of forearm and legs for two months. Family history of tuberculosis was positive. Mantoux test was 18 mm, ESR 85 mm in first hour, chest X-ray reveals right hilar lymphadenopathy, X-ray dorsolumber spine shows wedge shaped deformity in T11, L4 and with paravertebral collection from L2-L4. X-ray of legs, knee joint and forearms show multiple lytic lesions in shaft with periosteal reaction and cortical thickening. Ultrasonograph of whole abdomen shows psoas abscess. Culture of bone marrow aspirate reveals Mycobacterium tuberculosis. Patient was given an anti tubercular regimen with Rifampicin, Isoniazid, Pyrazinamide and Streptomycin for initial two months which to be followed by Rifampicin and Isoniazid for another 10 months.

Primary amebic meningoencephalitis

We report an 8 month-old infant with primary amebic meningoencephalitis (PAME) due to Naegleria fowleri. The child was treated with amphotericin B, chloramphenicol and rifampicin for 3 weeks. PAME is an almost universally fatal condition with very few survivors till date. Our patient was one of the rare survivors who recovered after treatment and was discharged without any residual neurological deficit.

"Moraxella lacunata" endocarditis treated with penicillin

The case report of a young male with Endocarditis caused by Moraxella lacunata is presented. Although a well recognized cause of keratitis, conjunctivitis, and sinusitis; very few cases of endocarditis by this rare pathogen are reported in literature. Patient showed a prompt response when empirical therapy was de-escalated to penicillin, after receiving culture and sensitivity report from Microbiology department.

Aspiration and tetracycline sclerotherapy of primary vaginal hydrocoele of testis in adults

BACKGROUND

Primary Vaginal Hydrocoele of Testis is a common condition which is primarily treated surgically. Many patients with Hydrocoele of testis are either not willing or are unfit for surgery. This study was done to know the safety, efficacy and out come of tetracycline induced sclerotherapy of Primary Vaginal Hydrocoele of Testis in adults.

METHODS

This quasi experimental study was done in Shahina Jamil Hospital, attached with Frontier Medical College and Ayub Teaching Hospital, Abbottabad from March 2006 to April, 2007. Thirty-seven patients with primary vaginal hydrocoele were included in the study. Aspiration and instillation of Tetracycline was done after spermatic cord block with 2% lignocaine. Procedure time, Peri and Post-procedure complications, number of injections for cure and patients' satisfaction with the procedure were recorded. Patients were discharged home 3 to 4 hours after the procedure and followed up after one week, one month, three months and six months. Direct admission and re-admissions were recorded.

RESULTS

The mean age of patients was 47 years. Mean procedure time was 45 minutes. All patients were cured. Mild postoprocedure pain occurred in 12 (40%), moderate pain in 14 (46%) patients and severe pain in 4 (13.3%) patients. No patient developed haematoma or local infection. One patient (3.3%) had micturition problem. Two (6.6%) patients had minimal recurrence. One injection was sufficient for cure in all patients. 28 (93%) patients were satisfied while 2 (6.6%) patients were not satisfied with this procedure. No patient was admitted in the hospital after the procedure.

CONCLUSION

Aspiration and injection of tetracycline in Primary vaginal Hydrocoele of Testis in adults is safe, effective and very economical procedure.

[Osteoarticular infections with staphylococcus aureus secreting Panton-Valentine leucocidin]

Panton-Valentine Leucocidin (PVL) is associated in the USA with community-acquired meticillin resistant strains of Staphylococcus aureus (CA-MRSA). Bone and joint infection due to such strains appears to be more severe, necessiting longer antibiotic course and various surgical procedure. Our study of 14 PVL positive bone and joint infection, performed in France where PVL is rarely (2/14) associated with meticillin resistance, demonstrates that severity is linked with PVL secretion more than with resistance. Considering PVL associated bone and joint infections as a toxin-mediated disease, prompt diagnosis is needed in order to start specific therapeutic procedures. PVL mediated infection could be evoked in front of severe acute osteomyelitis or arthritis, with radiological abnormalities present in the first days of evolution and with pejorative evolution despite antibiotic treatment. Evolution toward multifocal osteomyelitis and/or multiple abscesses seems to be a major characteristic of such infection. Therapeutic approach should use an association of parenteral antibiotics with at least one molecule active against protein synthesis like Clindamycin, associated with betalactams or Vancomycin in area of high incidence of CA-MRSA. Surgical procedure should be considered whenever focal abscesses of bones or adjacent tissue is detected and should be repeated in most cases.

Open label trial of clarithromycin therapy in Japanese patients with Crohn's disease

BACKGROUND AND AIM

The pathogenesis of Crohn's disease is unclear, but many studies suggest that luminal bacteria play an important role in chronic intestinal inflammation in patients with this condition. Clarithromycin is a macrolide antibiotic with immunomodulatory activity. The aim of this study was to evaluate the effect of clarithromycin therapy in Japanese patients with Crohn's disease.

METHODS

Fourteen patients with active Crohn's disease (12 with ileocolonic, one with colonic, one with small bowel type) were treated with oral clarithromycin 200 mg twice daily for 4 weeks. Patients who showed a clinical response within 4 weeks continued the therapy for up to 24 weeks. Four patients also received azathioprine. Clinical activity was assessed with the Crohn's Disease Activity Index (CDAI) at entry and at 4, 12, and 24 weeks after starting clarithromycin.

RESULTS

The mean CDAI score at entry was 343.5. Within 4 weeks, eight (57.1%) of the 14 patients showed clinical improvement, and five (35.7%) of the eight patients achieved remission. All of those eight patients continued clarithromycin therapy after 4 weeks, and six (42.9%) were in clinical remission at 12 weeks. Of the 14 total patients, four (28.6%) continued clarithromycin for more than 24 weeks, and have remained in remission. Patients who received azathioprine concomitantly had a better response to clarithromycin therapy. No severe side-effects were observed during the study period.

CONCLUSIONS

This open label study showed encouraging results of clarithromycin therapy in Japanese patients with active Crohn's disease.

Fusidin ameliorates experimental autoimmune myocarditis in rats by inhibiting TNF-alpha production

Experimental autoimmune myocarditis (EAM) represents a model for human autoimmune myocarditis, a condition for which no optimal treatment is currently available. It has been reported that tumor necrosis factor-alpha (TNF-alpha) plays a crucial role in pathogenesis of EAM. The immunomodulating antibiotic fusidic acid and its sodium salt (sodium fusidate-fusidin) were previously shown to reduce TNF-alpha production and its end-organ cytotoxicity, thus proving beneficial in several animal models of organ-specific autoimmune diseases. To investigate the effects of fusidin on EAM the drug was given at dose 80 mg/kg i.m. to EAM rats. Fusidin was administered as an early, from day 0 to 10, or late treatment, from day 10 to 21, after induction of disease. Both early and late treatment with fusidin markedly ameliorated the clinical and histological signs of the disease. Fusidin-treated rats had significantly decreased blood levels of TNF-a compared with vehicle-treated animals. Similarly, TNF-alpha production by in vitro sensitized lymph node cells in both fusidin treated groups was significantly lower than that in EAM rats. The present findings suggest that fusidin ameliorated EAM, at least partly, through an inhibitory action on the secretion of TNF-alpha.

Chloramphenicol: screening and review to evaluate its potential beneficial effects in leukaemia

Chloramphenicol is an antimicrobial agent having a very broad-spectrum of activity including Gram-positive bacteria, Gram-negative bacteria and anaerobes. However the use of chloramphenicol has reduced over a period of time due to the adverse effects of causing bone marrow depression or in some cases severe aplastic anaemia. As the effects are seen on the bone marrow cell, it was intended to find out if these adverse effects could be used for the benefits in leukaemia patients, using in-vitro study on leukaemic cell lines. The study showed inhibition of growth of the leukaemia cells by chloramphenicol which was comparable to or better than daunorubicin in some cell lines. The article also discusses the other adverse effect profile of chloramphenicol compared with anticancer drugs and its potential benefit in leukaemia and in neutropenic fever.

Effects of halofuginone on fibrosis formation secondary to experimentally induced subglottic trauma

OBJECTIVE

The aim of the study was to assess the antifibrotic effect of systemically applied halofuginone after subglottic injury.

MATERIALS AND METHODS

After standardized trauma to subglottic area, rats were divided into two groups: a study group that received treatment and a control group that did not. The rats were treated with 0.1 mg/kg/day intraperitoneal halofuginone injection for 30 days. The larynx specimens were examined histopathologically under light microscope for epithelization, inflammation, necrosis, and fibrosis.

RESULTS

The fibrosis indexes of the treated group were significantly less than those of the control group (P < .01).

CONCLUSIONS

Systemically applied halofuginone hydrobromide decreases fibrosis/scar tissue formation secondary to experimentally induced acute subglottic trauma.

Evaluation of endotoxaemia in the prognosis and treatment of scouring merino lambs

This study looked at measurement of endotoxaemia as a tool in determining prognosis and probable response to treatment in scouring lambs. One hundred eighty-three lambs in the first 15-20 days of life, from eight Merino sheep farms located in the region of La Serena, south-west Spain, were used in this experiment. Scouring and normal/control lambs were selected following a clinical examination, the scouring group was further divided into subgroups, specifically those that did or did not survive 72 h following treatment. At the time of the clinical examination, faecal and blood samples were taken. Faecal culture and commercial faecal antigen tests for detection of enteropathogens in faeces and serum endotoxin measurement using chromogenic lymulus amoebocyte lysate (LAL) were carried out. Scouring lambs received 0.07 mg/kg liveweight halofuginone once a day for 3 days, a single oral dose of 0.20 mg/kg liveweight of spectinomycin and oral rehydration fluid. The pathogens isolated were Cryptosporidium spp. and Escherichia coli. The case fatality rate was 51% in the scouring lambs. Postmortem findings were consistent with enterotoxigenic E. coli infection. The concentration of endotoxin was 0.18 +/- 0.12 ng/ml in the control group, 0.35 +/- 0.17 ng/ml in the surviving lambs and 0.46 +/- 0.14 ng/ml in the non-surviving lambs. Significant differences between groups were found. Case fatality rate of the scouring lambs with endotoxaemia below 0.30 ng/ml was 0%, while it was 100% above 0.50 ng/ml. These results may be utilized as a prognostic indicator in lambs affected by E. coli and Cryptosporidium that will help aid in decision-making as to whether to treat a lamb or not based on its chances of survival.

Association of HLA genes with diffuse panbronchiolitis in Chinese patients

Diffuse panbronchiolitis (DPB) is a pulmonary disease of unknown etiology that predominantly affects East Asians, particularly Japanese with a prevalence of 0.00028. Research has shown that HLA-B54 and HLA-A11 are positively associated with this disease. HLA-A, -B, and -DR loci were analyzed using an oligonucleotide microarray in both Chinese patients with DPB and normal control subjects. The most marked difference between the patients and the controls was the decreased frequency of HLA-A2 (p=0.001, OR=0.12), which showed a negative association with the disease; however, there was no significant contribution of HLA-B loci. Interestingly, the frequency of HLA-A11 was increased (p=0.007, OR=3.9), in accordance with previous reports on Japanese and Koreans. In addition, the frequency of HLA-DRB5*010/020 slightly increased (p=0.049). The HLA-associated genes for DPB are located between the HLA-A and HLA-B loci. Differences in HLA-associated genes may partially explain differences in the incidence of DPB among different populations.

Wogonin sensitizes resistant malignant cells to TNFα- and TRAIL-induced apoptosis

TNFα has previously been used in anticancer therapy. However, the therapeutic application of TNFα was largely limited due to its general toxicity and the fact that it activates the NF-κB–family transcription factors, which are proinflammatory and antiapoptotic. To overcome this problem in vitro, specific NF-κB inhibitors or transcription or protein synthesis inhibitors such as actinomycin D and cycloheximide are usually used in combination to increase TNFα killing of tumor cells. However, these agents also cause harmful side effects in vivo. We show here that wogonin, derived from the popular Chinese herb Huang-Qin, attenuates NF-κB activity by shifting TNFα-induced free radical ·O2– to a more reduced nonradical product, H2O2, and thereby sensitizes TNFα-resistant leukemia cells to TNFα-induced apoptosis. Importantly, wogonin does not affect the viability of normal peripheral blood T cells. Wogonin also sensitizes TRAIL-induced apoptosis. Our data suggest a potential use of wogonin as a TNFα or TRAIL adjuvant for cancer treatment. Our data also demonstrate how a herbal compound enhances killing of tumor cells with reduced side effects compared with other treatments.

[Use of linezolid for the treatment of lung infections in adults with cystic fibrosis]

INTRODUCTION

Linezolid, a new antistaphylococcal agent for oral or intravenous administration is active against Staphylococcus aureus with limited sensitivity to glycopeptides. The purpose of the present work was to compare data in the literature with practical clinical experience with the use of linezolid for lung infections in adult cystic fibrosis patients with the objective of developing local guidelines for use.

MATERIAL AND METHODS

This retrospective clinical study was conducted in the adult pneumology department of a university hospital.

RESULTS

The main clinical signs leading to prescription of linezolid were aggravating cough, bronchial obstruction, and exercise-induced fatigue. Among 42 cystic fibrosis patients, six aged 24+/-3 years were given 22 treatments of linezolid. Two patients were given the drug once and the others 2, 4, 5, and 9 times, 600 mg b.i.d. Mean duration of treatment with linezolid was 16+/-5 days. Among the six patients, two presented meti-R S. aureus infection. For twelve cases, clinical improvement was observed; and in two others the situation worsened leading to interruption of linezolid.

CONCLUSIONS

There are few reports in the literature on use of linezolid in cystic fibrosis patients. Writing internal guidelines for our department has enabled standardized use: 600 mg b.i.d. p.o. for 14 days as second-line treatment for bronchial exacerbation of S. aureus infection.