We report a 62-year-old woman presenting with nocardia brain abscess that mimics metastatic brain tumor. Six months before admission to our hospital, she presented with persistent hemoptysis, and a friable endobronchial mass was detected at another hospital. However, a definite diagnosis had not been made, and then she presented with hemianopia. Her laboratory analysis results showed that she had no immunological abnormalities. T1-weighted magnetic resonance images of the brain with Gd-DTPA revealed hyperintensive multiple masses with surrounding edema. We suspected this case as metastatic brain tumor of unknown origin, and the patient underwent biopsy of the supraclavicular lymph node. Histopathology results indicated abscess, and gram staining of material obtained from the abscess showed Gram-variable rods, which were determined upon culture as acid-fast Gram-positive branching rods and identified as Nocardia asteroides. Accordingly, we diagnosed the patient as having nocardia brain abscess, and she was treated with an oral antibiotic (TMP-SMX). Four months later, the abscesses disappeared. The patient recovered after prolonged TMP-SMX therapy with no recurrence in over 9 months.

Mycobacterium abscessus is the most pathogenic of the fast-growing mycobacteria, and it is resistant to most of the antimicrobial and tuberculostatic drugs available. This non-tuberculous mycobacterium is significant in medicine because it can contaminate post-traumatic wounds and be a causative agent in chronic skin and soft tissue infection after surgical procedures.A 60-year-old immunocompetent woman was suffering from chronic ulcers and abscesses on the heels and malleoli of both feet. Histological examination revealed a granulomatous inflammation with detection of acid-fast rods, albeit without fibrinoid necrosis. The repeated detection of atypical mycobacteria, which were ultimately identified as Mycobacterium abscessus, allowed the diagnosis of an atypical mycobacteriosis of the skin. This was successfully treated first with clarithromycin and rifabutin and later with a combination of ethambutol, minocycline, clofazimine and azithromycin.

Monolithic Performance C18 HPLC columns (Chromolith Performance RP-18e, Merck) were applied for the determination of pilocarpine hydrochloride in the presence of its degradation products isopilocarpine, pilocarpic acid and isopilocarpic acid. The method was validated using a set of six monolithic columns and compared to a conventional C18 column. The separation of pilocarpine from its degradation products was investigated on monolithic columns at different flow rates from 1 to 9 ml/min. Superior resolution was obtained using monolithic columns over the conventional C18 column at the same flow rate of 1 ml/min with a total run time of 9 min compared to 13.5 min for the conventional C18 column. Comparable resolution to that obtained in the C18 column (but with better peak symmetry) was obtained at a flow rate of 4 ml/min, although the total run time was reduced to 3.5 min. The precision for both retention time and peak area was investigated over a wide concentration range and found to be equal, or slightly better on Chromolith Performance compared to the conventional column. The overall RSDs% ranged from 0.5% to 1.16% for the conventional column, while for monolithic columns ranged from 0.38% to 0.87% at a flow rate of 1 ml/min and from 0.38% to 0.89% at a flow rate of 4 ml/min. Monolithic column to column reproducibility (n = 6) was measured. The RSDs% ranged from 0.34% to 0.68% for retention time and from 0.3% to 0.94% for peak areas. The detection and quantitation limits on monolithic columns at both flow rates (1 and 4 ml/min) were found to be 0.17 microg/ml and 0.5 microg/ml, compared to 0.31 microg/ml and 1 microg/ml on the conventional column. Monolithic silica rods have also shown the advantage of reducing the time to wash and to re-equilibrate the column. The method showed good linearity and recovery and was found to be suitable for the analysis of pilocarpine hydrochloride formulations.

Infection with marine bacteria is uncommon. A patient with systemic lupus erythematosus who developed concurrent infection with Shewanella putrefaciens and Mycobacterium marinum (M. marinum) is described. After bathing leg ulcers in sea water, severe cellulitis of the left leg with necrotic areas and extensive bullae developed. Infection due to S. putrefaciens was confirmed and a long course of hospitalization, oral ciprofloxacin and skin grafting was required. During hospitalization subcutaneous nodules developed on the other leg. Biopsy revealed acid-fast bacilli and culture grew M. marinum. These lesions responded to rifampicin and cotrimoxazole. Patients with leg ulcers, peripheral vascular disease, diabetes, or receiving immunosuppressive drugs may acquire unusual infections after salt water exposure.

Size-exclusion high-performance liquid chromatography with a TSK 5000 PW column was shown to be a fast and relatively inexpensive method for the size determination of lecithin-bile salt mixed micelles. Perturbation of the equilibrium between aqueous soluble and micellar bile salts during elution was avoided by preequilibration of the column with buffer containing the aqueous soluble concentration of the bile salt. Elution volumes were converted to size dimensions from a calibration curve produced from the elution volumes of proteins and small unilamellar vesicles of known size. Micelle sizes determined for several different lecithin-bile salt mixtures were consistent with those obtained by other techniques. The well-known hyperbolic increase in mixed micelle size as the lecithin to bile salt ratio approaches the micellar-vesicle phase limit was reproduced with this chromatographic technique. On the basis of these data and the recent observation by small-angle neutron scattering that lecithin-bile salt micelles increase in size by the elongation of constant-diameter rods [Hjelm et al. (1988) J. Appl. Crystallogr. 21, 858-863], a new model for the mixed micelle structure is proposed. According to this model, separation of the lecithin head groups by bile salts inserted along the rod surface produces a radial orientation of lecithin molecules along the length of the rod. Each end of the rod is sealed off by a lecithin-bile salt configuration that is richer in bile salts than the rod portion of the micelle. A simple mathematical description of this model predicts the observed changes in micellar size as a function of the lecithin-bile salt ratio with parameters that are consistent with lecithin and bile salt molecular dimensions.

Nocardia is an increasingly important opportunistic pathogen in immunosuppressed patients, especially solid organ transplant recipients. Infection is most often caused by Nocardia asteroides and presents as lung disease in 80% to 90% of infected transplant patients. Radiographic findings are nonspecific and include nodular infiltrates, cavitation, and pleural effusion. Dissemination to other organs, especially to the central nervous system (CNS) and skin, occurs in up to 40% of transplant recipients. A presumptive diagnosis is most rapidly made by the direct visualization in tissue, lower respiratory secretions, or wound drainage of filamentous, gram-positive, beaded rods that are partially acid fast. Specimens for culture should be held for at least 3 weeks when the diagnosis is suspected. The prognosis of nocardial infection is related to the site of disease, rapidity of diagnosis, and extended treatment with a sulfonamide. Mortality is highest in patients with CNS involvement. Prophylactic trimethoprim-sulfamethoxazole should be considered in transplant centers with excess rates of nocardial infection. Hopefully, future refinement of immunosuppressive regimens will be accompanied by a reduction in frequency of Nocardia infections in transplant recipients.