The effects of coital lubricants on sperm motility in vitro

Infertility affects approximately 15% of couples, and in about one- third the primary cause is a male factor. Patients undergoing infertility investigations frequently experience sexual dysfunction, which often is due to inadequate vaginal lubrication. This can lead to increased use of coital lubricants. The effects of such lubricants on sperm motility have not been widely studied, although sperm motility is one of the best prognostic indicators of fertilization. Using a prospective longitudinal control-based study, we analysed the effect of adding four lubricants: KY jelly, baby oil, olive oil and saliva on sperm motion in 16 samples from patients undergoing infertility investigations. Sperm samples were prepared by density gradient centrifugation prior to mixing with lubricants. Motility parameters were determined using computer-assisted semen analysis after 5, 15 and 30 min. All lubricants except baby oil significantly decreased percentage progressive motility, progressive velocity, curvilinear velocity and lateral head displacement at 12.5% concentration. At a lower concentration of 6.25%, both olive oil and saliva still significantly reduced progressive motility parameters, while KY jelly diminished head movement parameters. Hence, even at these very low concentrations, coital lubricants impair sperm motility and thus may adversely affect fertility.      

Top-down modulation of early sensory cortex

Data from nine previous studies of human visual information processing using positron emission tomography were reanalyzed to contrast blood flow responses during passive viewing and active discriminations of the same stimulus array. The analysis examined whether active visual processing (i) increases blood flow in medial visual regions early in the visual hierarchy and (ii) decreases blood flow in auditory and somatosensory cortex. Significant modulation of medial visual regions was observed in six of nine studies, indicating that top-down processes can affect early visual cortex. Modulations showed several task dependencies, suggesting that in some cases the underlying mechanism was selective (e.g. analysis-or feature-specific) rather than non- selective. Replicable decreases at or near auditory Brodmann area (BA) left 41/42 were observed in two of five studies, but in different locations. Analyses that combined data across studies yielded modest but significant decreases. Replicable decreases were not found in primary somatosensory cortex but were observed in an insular region that may be a somatosensory association area. Decreases were also noted in the parietal operculum (perhaps SII) and BA 40. These results are inconsistent with a model in which the precortical input to task- irrelevant sensory cortical areas is broadly suppressed.      

Computed tomography of desmoid tumors of bone: desmoplastic fibroma

Desmoplastic fibroma of bone is a rare benign tumor, first described by Jaffe in 1958 [6]. Since then approximately 80 cases have been reported in the long bones, although the tumor also involves the jaw bones, particularly the mandible. The plain film features consist of a lytic, expansile lesion, usually in the metaphysis of bone, sometimes extending into the soft tissues. We present two cases involving the long bones in which the correct diagnosis was suggested by computed tomography (CT). The CT appearance of the lesions is described.     

Synthesis of an arginine rich fragment of a viral coat protein using guanidinium functions exclusively

The N-terminal pentacosapeptide of Cowpea Chlorotic Mottle Virus (CCMV) was synthesized as the N^α25-acetyl, C^α25-methylamide. The compound contains six arginyl residues, which were incorporated in the peptide chain protected by protonation. The compound was obtained from an azide and a carbodiimide mediated condensation, unifying three fragments. The identity of the compound was proved by amino acid analysis, ¹³C-n.m.r. and ¹H-n.m.r. spectroscopy. It behaved like the native protein in its tendency to interact with viral RNA (fragments).     

Antiserum induced myelination inhibition in vitro without complement

Exposure of neonatal rat cerebellum cultures to antiserum to whole spinal cord or galactocerebroside inhibited myelin formation regardless of whether guinea pig serum was added fresh or after heating to 56 degrees C for 1 h in order to achieve complete removal of hemolytic complement activity. Myelination followed removal of antisera from the culture media. This suggests that the inhibition of primary myelination by anti-CNS tissue antiserum occurs through some mechanism other than as the result of a cytotoxic reaction against oligodendrocytes mediated via the complement system.