Large-scale screening of nasal swabs for Bacillus anthracis: descriptive summary and discussion of the National Institutes of Health's experience

In October 2001, a letter containing a large number of anthrax spores was sent through the Brentwood post office in Washington, D.C., to a United States Senate office on Capitol Hill, resulting in contamination in both places. Several thousand people who worked at these sites were screened for spore exposure by collecting nasal swab samples. We describe here a screening protocol which we, as a level A laboratory, used on very short notice to process a large number of specimens (3,936 swabs) in order to report preliminary results as quickly as possible. Six isolates from our screening met preliminary criteria for Bacillus anthracis identification and were referred for definitive testing. Although none of the isolates was later confirmed to be B. anthracis, we studied these isolates further to define their biochemical characteristics and 16S rRNA sequences. Four of the six isolates were identified as Bacillus megaterium, one was identified as Bacillus cereus, and one was an unidentifiable Bacillus sp. Our results suggest that large-scale nasal-swab screening for potential exposure to anthrax spores, particularly if not done immediately postexposure, may not be very effective for detecting B. anthracis but may detect a number of Bacillus spp. that are phenotypically very similar to B. anthracis.     

An unusual localization of mucormycosis diagnosed by fine needle aspiration cytology: a case report

Mucormycosis is an uncommon fungal infection, occurring mainly in patients with acidosis, chronic illnesses and malignancies. The most frequent site of involvement in patients of hematological malignancies is the respiratory tract. Isolated subcutaneous localization of mucormycosis in such patients is extremely rare. We report a case of a young patient of non-Hodgkin's lymphoma on chemotherapy who presented with a subcutaneous swelling on the anterior aspect of right thigh. Fine needle aspiration cytology (FNAC) smears from the swelling revealed numerous characteristic broad, irregularly contoured and pleomorphic hyphae of mucormycosis. This fungus seldom grows in culture and confirmation of the diagnosis depends on cytological or histological examination of infected tissues. Our case report documents a rare site of isolated mucormycosis infection and emphasizes the role of FNAC as a simple, rapid, accurate, and useful method of diagnosing fungal infections.     

Efficacy of 1% permethrin for the treatment of head louse infestations among Kosovar refugees

We assessed the prevalence of head louse infestation and the effectiveness of 1% permethrin against head lice in Kosovar refugees. A currently infested case was defined as a person with observable crawling lice (adults or nymphs) or a person with nits on the hair shaft within a quarter-inch of the scalp. Of the 1,051 refugees screened upon arrival in the United States, 107 (10%) were infested. Crawling lice (adults or nymphs) were observed on 62 (6%) of the individuals examined. Refugees with crawling lice were treated with a pediculicide containing 1% permethrin. Of these, 57 were reexamined the next day. Twenty of the 57 individuals were reexamined 7 days after treatment. No crawling lice were found on any of the refugees examined after treatment. We conclude that 1% permethrin treatment was effective in louse control in this refugee population.     

The PtdIns 3-Kinase/Akt Pathway Regulates Macrophage-Mediated ADCC against B Cell Lymphoma

Macrophages are important effectors in the clearance of antibody-coated tumor cells. However, the signaling pathways that regulate macrophage-induced ADCC are poorly defined. To understand the regulation of macrophage-mediated ADCC, we used human B cell lymphoma coated with Rituximab as the tumor target and murine macrophages primed with IFNγ as the effectors. Our data demonstrate that the PtdIns 3-kinase/Akt pathway is activated during macrophage-induced ADCC and that the inhibition of PtdIns 3-kinase results in the inhibition of macrophage-mediated cytotoxicity. Interestingly, downstream of PtdIns 3-kinase, expression of constitutively active Akt (Myr-Akt) in macrophages significantly enhanced their ability to mediate ADCC. Further analysis revealed that in this model, macrophage-mediated ADCC is dependent upon the release of nitric oxide (NO). However, the PtdIns 3-kinase/Akt pathway does not appear to regulate NO production. An examination of the role of the PtdIns 3-kinase/Akt pathway in regulating conjugate formation indicated that macrophages treated with an inhibitor of PtdIns 3-kinase fail to polarize the cytoskeleton at the synapse and show a significant reduction in the number of conjugates formed with tumor targets. Further, inhibition of PtdIns 3-kinase also reduced macrophage spreading on Rituximab-coated surfaces. On the other hand, Myr-Akt expressing macrophages displayed a significantly greater ability to form conjugates with tumor cells. Taken together, these findings illustrate that the PtdIns 3-kinase/Akt pathway plays a critical role in macrophage ADCC through its influence on conjugate formation between macrophages and antibody-coated tumor cells.     

Sedative drug requirements during bronchoscopy are higher in cystic fibrosis after lung transplantation

BACKGROUND: We noted that patients with cystic fibrosis tended to need higher doses of sedatives during bronchoscopy. We undertook this study to assess the sedative drug doses administered during bronchoscopy in lung transplant recipients and to assess if there is a change in the dosage requirements over time following lung transplantation. METHODS: In all, 773 transbronchial biopsy procedures performed via flexible bronchoscopy were analyzed in 140 consecutive lung transplant recipients. Conscious sedation was achieved with intermittent boluses of intravenous midazolam and fentanyl. Intravenous propofol boluses of 10 to 30 mg were administered when optimal sedation was not achieved with midazolam doses of 0.20 to 0.25 mg/kg and fentanyl 2 to 2.5 micrograms/kg. RESULTS: Mean doses of midazolam and fentanyl administered were 0.15+/-0.07 mg/kg (range 0.02 to 0.44 mg/kg) and 1.8+/-0.8 micrograms/kg (range 0.1 to 6.67 micrograms/kg) respectively. Midazolam and fentanyl doses administered to patients with cystic fibrosis were the highest compared to those with other disease types (P<0.0001). Examining the sedative doses administered over time following transplantation, there was a significant linear (P<0.001) and quadratic (P=0.0023) effect of time for midazolam and a significant linear (P=0.003) and a trend (P=0.08) for a quadratic effect for fentanyl. Propofol was effectively used in seven lung transplant recipients in whom adequate sedation could not be achieved with high doses of midazolam and fentanyl. CONCLUSIONS: There is an increase in sedative drug requirement with time for both midazolam and fentanyl after transplantation, which is significantly higher in patients with cystic fibrosis.     

Virtual bronchoscopy for diagnosis of inhalation injury in burnt patients

Virtual bronchoscopy using a multislice CT scanner, is a new non-invasive imaging technique and its utility in the diagnosis of inhalation injury in burnt patients has not been reported in literature yet. Initial experience of technique is encouraging and it merits more interest. It overcomes many of the limitations of the presently established procedure of fibreoptic bronchoscopy. Ten burned patients with clinical suspicion of inhalation injury underwent this investigation and in eight of these the diagnosis was confirmed.