A soluble protein is immobile in dormant spores of Bacillus subtilis but is mobile in germinated spores: implications for spore dormancy

Fluorescence redistribution after photobleaching has been used to show that a cytoplasmic GFP fusion is immobile in dormant spores of Bacillus subtilis but becomes freely mobile in germinated spores in which cytoplasmic water content has increased approximately 2-fold. The GFP immobility in dormant spores is not due to the high levels of dipicolinic acid in the spore cytoplasm, because GFP was also immobile in germinated cwlD spores that had excreted their dipicolinic acid but where cytoplasmic water content had only increased to a level similar to that in dormant spores of several other Bacillus species. The immobility of a normally mobile protein in dormant wild-type spores and germinated cwlD spores is consistent with the lack of metabolism and enzymatic activity in these spores and suggests that protein immobility, presumably due to low water content, is a major reason for the metabolic dormancy of spores of Bacillus species.     

Lipids in the inner membrane of dormant spores of Bacillus species are largely immobile

Bacterial spores of various Bacillus species are impermeable or exhibit low permeability to many compounds that readily penetrate germinated spores, including methylamine. We now show that a lipid probe in the inner membrane of dormant spores of Bacillus megaterium and Bacillus subtilis is largely immobile, as measured by fluorescence redistribution after photobleaching, but becomes free to diffuse laterally upon spore germination. The lipid immobility in and the slow permeation of methylamine through the inner membrane of dormant spores may be due to a significant (1.3- to 1.6-fold) apparent reduction of the membrane surface area in the dormant spore relative to that in the germinated spore, but is not due to the dormant spore's high levels of dipicolinic acid and divalent cations.     

Toxoplasma gondii myelitis in AIDS

Toxoplasmosis of the spinal cord is an uncommon manifestation of the acquired immunodeficiency syndrome (AIDS). Previously described patients generally have had poor outcomes. We report a case of successfully treated, biopsy-proven AIDS-related Toxoplasma gondii myelitis (TGM) in a 39-year old man who presented with a conus medullaris syndrome. A review of the literature and a suggested therapeutic approach to TGM are presented.     

Pseudotumor cerebri following eclampsia

Pseudotumor cerebri, or increased intracranial pressure without a mass lesion, has been associated with hormonal activity but the exact causative relation is still obscure. We report a case of a 15-year-old girl who developed pseudotumor cerebri manifested by headache, visual symptoms and extraocular muscle palsies 3 weeks after recovering from eclampsia. Possible associations with eclampsia and postpartum changes in estrogen, progesterone and prolactin are discussed.     

Subacute Sclerosing Panencephalitis and Acquired Immunodeficiency Syndrome: Role of Electroencephalography and Magnetic Resonance Imaging

Subacute sclerosing panencephalitis (SSPE) had largely disappeared from the United States because of nearly universal measles vaccination, but it has reemerged in children infected with human immunodeficiency virus (HIV) . Two children with SSPE are described . The first was HIV positive and presented with seizures and encephalopathy at the age of 21 months. The second developed myoclonus and dementia at age 4 years; she was not infected with HIV, but her mother had acquired immunodeficiency syndrom. Magnetic resonance imaging findings were nonspecific and could have been compatible with HIV encephalopathy. Electroencephalography was characteristic of SSPE, showing high-voltage, periodic slow-wave complexes and background slowing . The diagnosis of SSPE was confirmed by brain biopsy or high measles antibody titers in the cerebrospinal fluid.     

Epidural spinal infection in intravenous drug abusers

The incidence of spinal epidural abscess and disk space infection appears to be rising in intravenous drug-using patients. We report 18 cases seen over three years in two municipal hospitals. Staphylococcus aureus was the most common infective agent, but two patients had Mycobacterium tuberculosis infection. Computed tomography of the spine facilitates diagnosis. Early treatment improves outcome but host factors play a role in recovery.