Performance of an IS6110-based PCR assay and the COBAS AMPLICOR MTB PCR system for detection of Mycobacterium tuberculosis complex DNA in human lymph node samples

We compared the performance of two PCR assays, an IS6110-based in-house protocol and the COBAS AMPLICOR MTB PCR (COBAS MTB) system, for the detection of Mycobacterium tuberculosis complex in 43 human lymph node samples from 40 patients. For the in-house PCR and the COBAS MTB assays, respectively, sensitivities were 87.5% versus 45.5% (P < 0.05), specificities were 100.0% versus 91.3% (P > 0.05), and inhibition rates were 4.8% versus 19.5% (P < 0.05). For the COBAS MTB system, additional N-acetyl-L-cysteine-NaOH pretreatment of the samples changed neither the inhibition rate nor the sensitivity significantly.     

Metastatic carcinoma: an unusual cause of focal brain lesions in HIV infection

The most common causes of focal brain lesions (FBLs) in patients with HIV infection are cerebral toxoplasmosis, primary central nervous system lymphoma (PCNSL), and progressive multifocal leukoencephalopathy. Neoplasms other than PCNSL are uncommon. We report a rare case of metastatic carcinoma causing an FBL in a patient with HIV infection. The diagnostic workup and further management of FBLs in HIV are outlined in this review. The standard approach includes a lumbar puncture and cerebrospinal fluid (CSF) analysis for cytology and Epstein-Barr virus (EBV) DNA testing by polymerase chain reaction. Empiric therapy for PCNSL is justifiable for patients with positive CSF EBV-DNA test results and a positive single-photon emission computed tomography (SPECT) scan, especially if there has been no response to antitoxoplasmosis therapy. Brain biopsy may be indicated, however, in select cases that do not meet these criteria in order to identify potentially treatable infections and PCNSL.     

Cutaneous lymphocyte antigen expression on human effector B cells depends on the site and on the nature of antigen encounter

In contrast to T cells, information on skin-homing B cells expressing the cutaneous lymphocyte antigen (CLA) is sparse. CLA expression on human B cells was investigated among circulating immunoglobulin-secreting cells (ISC) and among antigen-specific antibody-secreting cells (ASC) elicited by parenteral, oral or rectal primary immunization, or by parenteral or oral secondary immunization with Salmonella typhi Ty21a. CLA expression was examined by combining cell sorting with an enzyme-linked immunospot assay. Among all ISC, the proportion of CLA(+) cells was 13-21%. Parenteral immunization induced antigen-specific ASC of which 13% were CLA(+), while oral and rectal immunizations were followed by only 1% of CLA(+) ASC (p<0.001). Oral re-immunization was followed by an up-regulation of CLA (34-48%) regardless of the route of priming. Parenteral re-immunization elicited ASC of which 9-14% were CLA(+). In conclusion, the expression of CLA on human effector B cells depends on the site of antigen encounter: intestinal stimulation elicits cells with no CLA, while parenteral encounter elicits significant numbers of CLA(+) cells. Even though primary antigen encounter in the intestine failed to stimulate CLA expression, up-regulation of CLA was found upon intestinal antigen re-encounter. These findings may be of relevance in the pathogenesis of some cutaneous disorders.     

Rapid identification of Candida dubliniensis using a species-specific molecular beacon

Candida dubliniensis is an opportunistic fungal pathogen that has been linked to oral candidiasis in AIDS patients, although it has recently been isolated from other body sites. DNA sequence analysis of the internal transcribed spacer 2 (ITS2) region of rRNA genes from reference Candida strains was used to develop molecular beacon probes for rapid, high-fidelity identification of C. dubliniensis as well as C. albicans. Molecular beacons are small nucleic acid hairpin probes that brightly fluoresce when they are bound to their targets and have a significant advantage over conventional nucleic acid probes because they exhibit a higher degree of specificity with better signal-to-noise ratios. When applied to an unknown collection of 23 strains that largely contained C. albicans and a smaller amount of C. dubliniensis, the species-specific probes were 100% accurate in identifying both species following PCR amplification of the ITS2 region. The results obtained with the molecular beacons were independently verified by random amplified polymorphic DNA analysis-based genotyping and by restriction enzyme analysis with enzymes BsmAI and NspBII, which cleave recognition sequences within the ITS2 regions of C. dubliniensis and C. albicans, respectively. Molecular beacons are promising new probes for the rapid detection of Candida species.     

Interpregnancy Interval and Birth Outcomes: A Propensity Matching Study in the California Population

Maternal and Child Health Journal - Previous studies that used traditional multivariable and sibling matched analyses to investigate interpregnancy interval (IPI) and birth outcomes have reached...     

Covid-19 Pandemic: Resumption of Orthopedic Care and Medical Education

Covid-19 is a respiratory disease caused by coronavirus 2 (SARS-CoV-2) first identified in Wuhan, China (December 2019). The disease rapidly crossed the barrier of countries, continents and spread globally. Non-pharmaceutical measures such as social distancing, face mask, frequent hand washing and use of sanitizer remained the best available option to prevent the spread of disease. OPD, IPD admissions, elective O. Ts were curtailed. Orthopedic care was only limited to emergency and semi-urgent procedures like necrotizing fasciitis, open fracture, and compartment syndrome. These measures were taken to preserve infrastructure and manpower to manage covid-19 pandemic. The children were thought to have a low susceptibility to covid-19 as compared to an adult. Deferring the patient during pandemic has led to high orthopedic disease burden, morbidity and disease-related sequelae, hence elective care must be resumed with modified hospital infrastructure. Resumption of elective/emergent orthopedic care should be slow, phasic and strategic, much similar to unlocking. Cases must be stratified depending on covid status and severity. Dedicated O.Ts with neutral/negative pressure and HEPA filter for covid positive and suspected patients are to be used. All symptomatic and suspected patients should be investigated for covid-19 by RT-PCR, blood counts and CT scan. Regional anaesthesia should be preferred to General anaesthesia. Power drill/saw/burr/pulse lavage should be minimized to avoid aerosol generation. Postoperatively continuous surveillance and monitoring to be done for covid related symptoms. Medical institutes rapidly shifted to the online mode of education. Blended learning (virtual & physical) and imparting skills have to be continued in post covid phase with equitable distribution of teaching hours to students of different years.     

Lambert-Eaton myaesthenic syndrome: a possible association with Hodgkin's lymphoma

Lambert-Eaton myasthenic syndrome is a presynaptic neuromuscular junction disorder typically associated with small cell lung carcinoma. The characterstic electrophysiological abnormality is a low amplitude compound muscle action potential that shows a marked increment after maximal voluntary contraction or brief tetanic nerve stimulation. We describe a patient who had LEMS in association with Hodgkin's disease. A 61 year old woman presented with proximal muscle weakness 6 years following successful treatment of Hodgkin's disease. Her symptoms responded well to treatment with diaminopyridine. 9 additional patients have been described with LEMS in association with lymphoproliferative diseases. A systemic malignancy is usually found within 2 years of LEMS diagnosis but may present later. LEMS should be considered in patients with Hodgkin's disease presenting with muscle weakness.     

Epidemiology of early neonatal mortality

During 1981-1991 at a rural teaching hospital (Kasturba Hospital) of Mahatma Gandhi Institute of Medical Sciences in Sevagram, Wardha, India, 454 of 13,939 newborns died during the early neonatal period for an early neonatal mortality rate (ENMR) of 33.7/1000 live births. The ENMR for boys was not significantly different from that for girls (36.1 vs. 28.6). Community medicine specialists analyzed data on these early neonatal deaths to examine distribution of early neonatal mortality, especially its relationship with prematurity, low birth weight, birth order, and by sex. They calculated average percent deaths (APD) per hour to examine the dynamics in early neonatal mortality. The mean age at death was lower among newborns of birth order greater than 2 than those of birth order less than 2 (23.47 vs. 26.85 hours; p 0.001). ENMR was higher for newborns of birth order greater than 2 than those of birth order less than 2 (41.74% vs. 27.35%; P 0.001). The mean age at death increased as gestation increased (10.34 for 28 weeks; 24.27 for 28-33 weeks, 31.53 for 33-37 weeks, and 34.43 for 37 weeks; p 0.001). ENMR decreased as gestation increased (850 for 28 weeks; 375 for 28-33 weeks, 147.02 for 33-37 weeks, and 8.77 for 37 weeks; p 0.001). The mean age at death increased as birth weight increased for newborns weighing less than 1500 gms through 2000-2500 gms (23.36-37.13 hours; p 0.001). It was lowest among those weighing more 3000 gms (11.55 gms). ENMR fell as birth weight increased (614.33 for 1500 gms, 116.19 for 1500-2000 gms, 19.38 for 2000-2500 gms, 10.99 for 2500-3000 gms, and 5.41 for 3000 gms; p 0.001). The APD/hour for the first hour of life was 3.74% for a relative risk of 12.9. It decreased steadily as the hours of life increased (3.08% for 1-6 hours, 1.19% for 6-24 hours, 0.67% for 24-72 hours, and 0.29% for 72-168 hours). Knowledge of time of likely death can help providers know where they need to focus their attention to prevent early neonatal deaths.