A mimic's imitator: a cavitary pneumonia in a myasthenic patient with history of tuberculosis.

A 77-year-old man with myasthenia gravis receiving prednisone and plasmapheresis was found to have right upper lobe cavitary pneumonia on radiological imaging studies after thymectomy. He had a remote history of treated pulmonary tuberculosis (TB) at the age of 19. On the basis of history of TB and current prednisone therapy, reactivation of pulmonary TB was highly suspected. Branching Gram-positive bacilli were identified on bronchoalveolar lavage (BAL). BAL Ziehl-Neelsen Acid-fast bacilli stain was negative, but a modified Kinyoun stain revealed branching, beaded, filamentous bacilli, suggestive of Nocardia spp. Nocardia cyriacigeorgica grew from the BAL culture. Cerebral MRI demonstrated a right frontal lobe lesion, clinically correlated to be nocardial brain abscess. The patient was treated with three-drug antimicrobial therapy (trimethoprim-sulfamethoxazole, meropenem, linezolid) for 2 months, followed by an additional 10 months of trimethoprim-sulfamethoxazole. Amikacin would have been included in the initial three-drug regimen, but its use was contraindicated in our myasthenic patient because aminoglycoside would trigger fatal myasthenic crisis by neuromuscular blockage. Follow-up imaging studies revealed resolution of the lung and brain lesions.

Fusarium brain abscess: case report and literature review.

Severely immunocompromised patients such as those with haematological malignancies and haematopoietic stem cell transplant recipients are at an increased risk of acquiring invasive mould infections. Fusarium, a ubiquitous fungus, can cause potentially fatal infections in such hosts. It usually manifests as skin lesions, fevers and sino-pulmonary infections. Brain abscesses have been reported, but are relatively uncommon. We report a case of a 50-year-old patient with acute lymphocytic leukaemia and failed autologous peripheral stem cell transplant that presented with new onset seizures and was found to have Fusarium solani brain abscess. Nasal route was the presumed mode of entry of the fungus into the cerebrum. Treatment comprised surgical excision of the lesion, and antimycotic therapy with liposomal amphotericin B and voriconazole. Despite aggressive therapy, patient succumbed to the disease. We have provided an overview of infections secondary to Fusarium, along with a review of the central nervous system involvement by this pathogenic mould.

Growth of LAPC4 prostate cancer xenograft tumor is insensitive to 5α-reductase inhibitor dutasteride.

Intermittent androgen deprivation therapy (IADT) allows prostate cancer patients a break from the side-effects of continuous androgen deprivation therapy (ADT). Although clinical studies suggest that IADT can significantly improve patient quality of life over ADT, it has not been demonstrated to improve patient survival. Recently, increased survival has been demonstrated when 5α-reductase inhibitors have been used during the off-cycle of IADT in animal xenograft tumor models LNCaP and LuCaP35. In the current study, the sensitivity of LAPC4 xenograft tumor regrowth to the 5ARI dutasteride was determined. Tumor regrowth and gene expression changes in LAPC4 tumors were compared to the previously determined response of LNCaP and LuCaP35 xenograft tumors to 5ARI treatment during the off-cycle of IADT, LAPC4, LNCaP and LuCaP35 tumors were sensitive to androgen manipulation. However, in contrast to LNCaP and LuCaP35, dutasteride treatment during testosterone-stimulated prostate regrowth did not affect tumor regrowth or the expression of androgen responsive genes. Tumor response to dutasteride during the off-cycle of IADT is variable in xenograft prostate tumor models. Future studies will be required to elucidate the mechanisms contributing to the dutasteride resistance observed in the LAPC4 model during the off-cycle.