Studies of the photooxidant properties of antibacterial fluoroquinolones and their naphthalene derivatives.

We synthesized and determined the production of reactive oxygen species (ROS) as 1O2, *-O2, *OH, H2O2 during the photolysis with UV-A light of three antibacterial quinolones and their naphthyl ester derivatives. Singlet oxygen and ROS dose-dependant generation from norfloxacin (1), enoxacin (2), ciprofloxacin (3) and their respective naphthyl ester derivatives 4-6 were detecting in cell-free systems by the histidine assay and by luminol-enhanced chemiluminescence (LCL). Both the electronic absorption and emission spectra were quantified and their photostability determined. The antibacterial activity in darkness and under irradiation of compounds 4, 5 and 6 was tested on E. coli and compared with their parent drugs.

Screening for 21-hydroxylase-deficient nonclassic adrenal hyperplasia among hyperandrogenic women: a prospective study.

OBJECTIVE: To prospectively establish the specificity, sensitivity, and positive predictive value (PPV) of a basal 17-hydroxyprogesterone (17-HP) level for the screening of 21-hydroxylase-deficient nonclassic adrenal hyperplasia (NCAH) among hyperandrogenic women. DESIGN: Prospective observational trial. SETTING: Tertiary care academic medical centers. PATIENT(S): Eight healthy controls, 20 patients with NCAH, and 284 consecutively seen patients with hyperandrogenism. INTERVENTION(S): All controls and patients with NCAH, and select patients with hyperandrogenism, underwent acute ACTH (1-24) stimulation. MAIN OUTCOME MEASURE(S): Specificity was determined by measuring 17-HP every other day during one menstrual cycle in 8 healthy women with normal ovulation (107 samples). Sensitivity was determined by measuring 17-HP between 7 and 9 A.M. and 3 and 5 P.M. on the same day in 20 patients with genetically confirmed NCAH. The PPV was determined by prospectively measuring 17-HP in 284 consecutively seen hyperandrogenic women at their initial evaluation. The diagnosis of NCAH was established by a stimulated 17-HP level of >10 ng/mL. RESULT(S): Among controls, 17-HP levels of <2, <3, and <4 ng/mL all had a specificity of 100% when obtained in the follicular phase; when obtained in the luteal phase, they had specificities of 53%, 82%, and 82%, respectively. Among patients with NCAH, 17-HP levels of >2, >3, and >4 ng/mL had sensitivities of 100%, 90%, and 90%, respectively, for the detection of the disorder when obtained in the morning, and sensitivities of 95%, 90%, and 85%, respectively, when obtained in the afternoon. Among the 284 consecutively seen hyperandrogenic women, the PPVs of the first and second 17-HP levels were 7.3% and 19% for a cutoff level of >2 ng/mL, 13% and 43% for a cutoff level of >3 ng/mL, and 33% and 40% for a cutoff level of >4 ng/mL, respectively. CONCLUSION(S): A basal 17-HP level is a useful screening tool for NCAH. A cutoff level of 4 ng/mL has maximum specificity and PPV, with little loss in sensitivity if testing is performed in the morning and during the follicular phase. However, a lower cutoff level (e.g., 2 or 3 ng/mL) is preferable if testing is performed at odd hours of the day, as is common in many practices, and maximum sensitivity is desired.

Clinical features of early-onset Alzheimer disease in a large kindred with an E280A presenilin-1 mutation.

OBJECTIVES: To characterize clinical features of a very large pedigree with early-onset Alzheimer disease (AD) in which all affected individuals carry the identical glutamic acid-to-alanine mutation at codon 280 in the presenilin-1 gene. DESIGN: Clinical histories were obtained by patient and family interviews and through medical or civil records. Using standard diagnostic criteria, a case series of 128 individuals was identified, of which 6 have definitive (autopsy-proven) early-onset AD, 93 have probable early-onset AD, and 29 have possible early-onset AD. SETTING: Community based in Antioquia, Colombia. PATIENTS: A population-based sample in which all members of 5 extended families (nearly 3000 individuals) were surveyed. Criteria for inclusion required obtaining sufficient information to categorize the individual as affected. MAIN OUTCOME MEASURES: Age at onset, neuropsychological profile, neurologic history, and examination. RESULTS: The patients had a mean age at onset of 46.8 years (range, 34-62 years). The average interval until death was 8 years. Headache was noted in affected individuals significantly more frequently than in those not affected. The most frequent presentation was memory loss followed by behavior and personality changes and progressive loss of language ability. In the final stages, gait disturbances, seizures, and myoclonus were frequent. CONCLUSIONS: Other than the early onset, this clinical phenotype is indistinguishable from sporadic AD except that affected individuals frequently complained of headache preceding and during the disease. Despite the uniform genetic basis for the disease, there was significant variability in the age at onset, suggesting an important role for environmental factors or genetic modifiers in determining the age at onset.

The E280A presenilin 1 Alzheimer mutation produces increased A beta 42 deposition and severe cerebellar pathology.

Missense mutations in the presenilin 1 (PS1) gene cause the most common form of dominant early-onset familial Alzheimer's disease (FAD) and are associated with increased levels of amyloid beta-peptides (A beta) ending at residue 42 (A beta 42) in plasma and skin fibroblast media of gene carriers. A beta 42 aggregates readily and appears to provide a nidus for the subsequent aggregation of A beta 40 (ref. 4), resulting in the formation of innumerable neuritic plaques. To obtain in vivo information about how PS1 mutations cause AD pathology at such early ages, we characterized the neuropathological phenotype of four PS1-FAD patients from a large Colombian kindred bearing the codon 280 Glu to Ala substitution (Glu280Ala) PS1 mutation. Using antibodies specific to the alternative carboxy-termini of A beta, we detected massive deposition of A beta 42, the earliest and predominant form of plaque A beta to occur in AD (ref. 6-8), in many brain regions. Computer-assisted quantification revealed a significant increase in A beta 42, but not A beta 40, burden in the brains from 4 PS1-FAD patients compared with those from 12 sporadic AD patients. Severe cerebellar pathology included numerous A beta 42-reactive plaques, many bearing dystrophic neurites and reactive glia. Our results in brain tissue are consistent with recent biochemical evidence of increased A beta 42 levels in PS1-FAD patients and strongly suggest that mutant PS1 proteins alter the proteolytic processing of the beta-amyloid precursor protein at the C-terminus of A beta to favor deposition of A beta 42.

Crystallization, sequence, and preliminary crystallographic data for an antipeptide Fab 50.1 and peptide complexes with the principal neutralizing determinant of HIV-1 gp120.

X-ray quality crystals of an Fab fragment from an antipeptide monoclonal antibody (R/V3-50.1) that recognizes the principal neutralizing determinant (PND) of the gp120 glycoprotein of human immunodeficiency virus type 1 (HIV-1) (MN isolate) were grown as uncomplexed and peptide complexed forms. Crystals of the free Fab grew from high salt in orthorhombic space groups P2(1)2(1)2(1) and I222 and from polyethylene glycol in space groups P1 and P2(1). Seeds from either the P1 and P2(1) native (uncomplexed) Fab crystals induced nucleation of crystals of the Fab complexed to a 16-residue synthetic peptide corresponding to the PND when streak seeded into preequilibrated solutions of this complex. Data were collected from these complex crystals and from each of the four native Fab forms to at least 2.8 A resolution. The genes for the variable domain of the Fab were cloned and sequenced and the primary amino acid sequence was deduced from this information. Knowledge of the three-dimensional structure of this Fab-peptide complex will be important in the understanding of the PND of HIV-1 and its recognition by neutralizing monoclonal antibodies.