Treatment of pediatric extra-axial sinogenic infection: case series and literature review.

PURPOSE: Analyze the clinical presentation, microbiology, outcomes, and medical and surgical treatment strategies of intracranial extension of sinogenic infection in pediatric patients. METHODS: A retrospective, single-center study of patients < 18 years of age, presenting with intracranial extension of bacterial sinogenic infections requiring surgical intervention over a 5-year period, was conducted. Electronic medical records were reviewed for age, sex, primary symptoms, duration of symptoms, presence of sinusitis at initial presentation, microorganisms isolated, mode of surgery, timing of surgery, length of stay, and neurologic sequelae. RESULTS: Seventeen patients were identified; mean age was 10 years with 82.3% male predominance. Average duration of illness prior to presentation was 9.8 days, with 64.7% of patients displaying disease progression while on oral antibiotics prior to presentation. Sinusitis and intracranial extension were present in all patients upon admission. Simultaneous endoscopic endonasal drainage and craniotomy were performed on 70.5% of the patients, with the remaining 29.5% undergoing endonasal drainage only. Of the patients who underwent simultaneous endoscopic endonasal drainage and craniotomy, 17.6% required repeat craniotomy and 5.8% required repeat sinus surgery. The most commonly isolated organisms were S. intermedius (52.9%), S. anginosus (23.5%), and S. pyogenes (17.6%). All patients were treated postoperatively antibiotic on average 4-6 weeks. Frequently occurring long-lasting complications included seizures (29.4%) and focal motor deficits (17.6%); learning disability, anxiety disorders, impaired cognition, and sensory deficits occurred less frequently. CONCLUSION: In the case of intracranial extension of bacterial sinogenic infection, early identification and surgical treatment are crucial to avoid neurological sequelae.

Sputum Microscopy With Fluorescein Diacetate Predicts Tuberculosis Infectiousness.

Background: Sputum from patients with tuberculosis contains subpopulations of metabolically active and inactive Mycobacterium tuberculosis with unknown implications for infectiousness. Methods: We assessed sputum microscopy with fluorescein diacetate (FDA, evaluating M. tuberculosis metabolic activity) for predicting infectiousness. Mycobacterium tuberculosis was quantified in pretreatment sputum of patients with pulmonary tuberculosis using FDA microscopy, culture, and acid-fast microscopy. These 35 patients' 209 household contacts were followed with prevalence surveys for tuberculosis disease for 6 years. Results: FDA microscopy was positive for a median of 119 (interquartile range [IQR], 47-386) bacteria/µL sputum, which was 5.1% (IQR, 2.4%-11%) the concentration of acid-fast microscopy-positive bacteria (2069 [IQR, 1358-3734] bacteria/µL). Tuberculosis was diagnosed during follow-up in 6.4% (13/209) of contacts. For patients with lower than median concentration of FDA microscopy-positive M. tuberculosis, 10% of their contacts developed tuberculosis. This was significantly more than 2.7% of the contacts of patients with higher than median FDA microscopy results (crude hazard ratio [HR], 3.8; P = .03). This association maintained statistical significance after adjusting for disease severity, chemoprophylaxis, drug resistance, and social determinants (adjusted HR, 3.9; P = .02). Conclusions: Mycobacterium tuberculosis that was FDA microscopy negative was paradoxically associated with greater infectiousness. FDA microscopy-negative bacteria in these pretreatment samples may be a nonstaining, slowly metabolizing phenotype better adapted to airborne transmission.

Clinical evaluation of tuberculosis viability microscopy for assessing treatment response.

BACKGROUND: It is difficult to determine whether early tuberculosis treatment is effective in reducing the infectiousness of patients' sputum, because culture takes weeks and conventional acid-fast sputum microscopy and molecular tests cannot differentiate live from dead tuberculosis. METHODS: To assess treatment response, sputum samples (n=124) from unselected patients (n=35) with sputum microscopy-positive tuberculosis were tested pretreatment and after 3, 6, and 9 days of empiric first-line therapy. Tuberculosis quantitative viability microscopy with fluorescein diacetate, quantitative culture, and acid-fast auramine microscopy were all performed in triplicate. RESULTS: Tuberculosis quantitative viability microscopy predicted quantitative culture results such that 76% of results agreed within ±1 logarithm (rS=0.85; P<.0001). In 31 patients with non-multidrug-resistant (MDR) tuberculosis, viability and quantitative culture results approximately halved (both 0.27 log reduction, P<.001) daily. For patients with non-MDR tuberculosis and available data, by treatment day 9 there was a >10-fold reduction in viability in 100% (24/24) of cases and quantitative culture in 95% (19/20) of cases. Four other patients subsequently found to have MDR tuberculosis had no significant changes in viability (P=.4) or quantitative culture (P=.6) results during early treatment. The change in viability and quantitative culture results during early treatment differed significantly between patients with non-MDR tuberculosis and those with MDR tuberculosis (both P<.001). Acid-fast microscopy results changed little during early treatment, and this change was similar for non-MDR tuberculosis vs MDR tuberculosis (P=.6). CONCLUSIONS: Tuberculosis quantitative viability microscopy is a simple test that within 1 hour predicted quantitative culture results that became available weeks later, rapidly indicating whether patients were responding to tuberculosis therapy.

Evaluation of bleach-sedimentation for sterilising and concentrating Mycobacterium tuberculosis in sputum specimens.

BACKGROUND: Bleach-sedimentation may improve microscopy for diagnosing tuberculosis by sterilising sputum and concentrating Mycobacterium tuberculosis. We studied gravity bleach-sedimentation effects on safety, sensitivity, speed and reliability of smear-microscopy. METHODS: This blinded, controlled study used sputum specimens (n = 72) from tuberculosis patients. Bleach concentrations and exposure times required to sterilise sputum (n = 31) were determined. In the light of these results, the performance of 5 gravity bleach-sedimentation techniques that sterilise sputum specimens (n = 16) were compared. The best-performing of these bleach-sedimentation techniques involved adding 1 volume of 5% bleach to 1 volume of sputum, shaking for 10-minutes, diluting in 8 volumes distilled water and sedimenting overnight before microscopy. This technique was further evaluated by comparing numbers of visible acid-fast bacilli, slide-reading speed and reliability for triplicate smears before versus after bleach-sedimentation of sputum specimens (n = 25). Triplicate smears were made to increase precision and were stained using the Ziehl-Neelsen method. RESULTS: M. tuberculosis in sputum was successfully sterilised by adding equal volumes of 15% bleach for 1-minute, 6% for 5-minutes or 3% for 20-minutes. Bleach-sedimentation significantly decreased the number of acid-fast bacilli visualised compared with conventional smears (geometric mean of acid-fast bacilli per 100 microscopy fields 166, 95%CI 68-406, versus 346, 95%CI 139-862, respectively; p = 0.02). Bleach-sedimentation diluted paucibacillary specimens less than specimens with higher concentrations of visible acid-fast bacilli (p = 0.02). Smears made from bleach-sedimented sputum were read more rapidly than conventional smears (9.6 versus 11.2 minutes, respectively, p = 0.03). Counting conventional acid-fast bacilli had high reliability (inter-observer agreement, r = 0.991) that was significantly reduced (p = 0.03) by bleach-sedimentation (to r = 0.707) because occasional strongly positive bleach-sedimented smears were misread as negative. CONCLUSIONS: Gravity bleach-sedimentation improved laboratory safety by sterilising sputum but decreased the concentration of acid-fast bacilli visible on microscopy, especially for sputum specimens containing high concentrations of M. tuberculosis. Bleach-sedimentation allowed examination of more of each specimen in the time available but decreased the inter-observer reliability with which slides were read. Thus bleach-sedimentation effects vary depending upon specimen characteristics and whether microscopy was done for a specified time, or until a specified number of microscopy fields had been read. These findings provide an explanation for the contradictory results of previous studies.

A Low-Power, Single-Chip Electronic Skin Interface for Prosthetic Applications.

A low-power, single-chip electronic skin interface is presented. The system on chip (SoC) implementation significantly reduces the physical footprint and power requirements compared to commercial interfaces, which enables the creation nimble prosthetic limbs. Its small size and reduced battery requirements are ideal for advanced prosthetics that utilize electronic skin to provide their user tactile feedback. The architecture consists of multiple charge-sensitive analog front ends (AFEs) interfaced to a central, 16-bit microcontroller core which is capable of processing the sensory information in real time. Event-driven operation allows the chip to monitor all input channels while consuming minimal energy. A test chip has been fabricated in a 0.13  µm CMOS technology and its functionality demonstrated by interfacing the chip to a prototype electronic skin based on polyvinylidene fluoride (PVDF) piezoelectric sensors. Tactile signals from the sensors are measured and processed on-chip to calculate the corresponding charge. This is accomplished by programming the microcontroller with a custom software algorithm, granting the system the flexibility to interface to different types of sensors. The single-chip electronic skin system consumes 7.0 µW per channel and 93.5 µW in the example application when stimulated at 1 Hz, making it suitable for use with battery-powered prosthetics.

Optimizing tuberculosis testing for basic laboratories.

Optimal tuberculosis testing usually involves sputum centrifugation followed by broth culture. However, centrifuges are biohazardous and scarce in the resource-limited settings where most tuberculosis occurs. To optimize tuberculosis testing for these settings, centrifugation of 111 decontaminated sputum samples was compared with syringe-aspiration through polycarbonate membrane-filters that were then cultured in broth. To reduce the workload of repeated microscopic screening of broth cultures for tuberculosis growth, the colorimetric redox indicator 2,3-diphenyl-5-(2-thienyl) tetrazolium chloride was added to the broth, which enabled naked-eye detection of culture positivity. This combination of filtration and colorimetric growth-detection gave similar results to sputum centrifugation followed by culture microscopy regarding mean colony counts (43 versus 48; P = 0.6), contamination rates (0.9% versus 1.8%; P = 0.3), and sensitivity (94% versus 95%; P = 0.7), suggesting equivalency of the two methods. By obviating centrifugation and repeated microscopic screening of cultures, this approach may constitute a more appropriate technology for rapid and sensitive tuberculosis diagnosis in basic laboratories.

Thrombosis after septal closure device placement: a review of the current literature.

Thrombus formation has been described for all types of commercially available transcatheter septal occlusion devices. Most reports have been single-institution case studies. Screening for hypercoagulable conditions prior to device placement and anticoagulation after device deployment has been variable. The objective of this study was to synthesize the current experience with device thrombosis; the Medline database from 1980 until 2004 was searched. Seventeen articles identified 54 unique patients with device thrombosis. Thrombus developed on eight different types of transcatheter devices. All commercially available devices had at least one reported case of thrombosis. Patient mean age was 44.2 +/- 9.8 years. Thrombosis was diagnosed at a mean of 5 months after device deployment. Prior to device placement, 12 patients had normal coagulation evaluations and 5 had coagulopathies. For 37 patients, no mention was made in the report of coagulation studies. Prior to device thrombosis, 26 patients received aspirin and clopidogrel, 15 patients received aspirin alone, 8 received warfarin, 2 heparin alone, 1 aspirin and warfarin. One patient with hemophilia A received no anticoagulation and in one case treatment prior to thrombosis was not reported. After device thrombosis, 35 patients were treated with warfarin with thrombus resolution, 2 had successful lytic therapy, 1 was treated with heparin alone. Sixteen patients had surgical explantation of the device. Septal occlusion device thrombosis is rare. All types of commercially available devices have been associated with thrombosis. All patients should have early (< or = 3 months) echocardiographic surveillance for device thrombosis. Thorough coagulation evaluation is imperative prior to transcatheter device placement.