Fusobacterium nucleatum inhibits human T-cell activation by arresting cells in the mid-G1 phase of the cell cycle.

Fusobacterium nucleatum has been implicated in the pathogenesis of several diseases, including urinary tract infections, bacteremia, pericarditis, otitis media, and disorders of the oral cavity such as pulpal infections, alveolar bone abscesses, and periodontal disease. We have previously demonstrated that sonic extracts of F. nucleatum FDC 364 were capable of inhibiting human T-cell responses to mitogens and antigens. In this study, we have further characterized this immunosuppressive protein (FIP) and initiated experiments to determine its mode of action. The purified FIP has an apparent molecular mass of 90 to 100 kDa; sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicates that the FIP is actually composed of two subunits with molecular masses of 48 and 44 kDa. Purified FIP retained its biological activity and was capable of inhibiting mitogen-induced proliferation of human T cells. Inhibition was dose dependent, and the FIP exhibited a specific activity approximately 250-fold greater than that of the crude extract. Cell cycle analysis indicates that FIP-treated cells were prevented from exiting the G0/G1 phase of the cell cycle. However, FIP did not alter the expression of activation markers (CD69, CD25, and CD71) or interleukin-2 secretion. The latter observations suggest that the T cells did indeed become activated and had entered the G1 phase of the cell cycle. Analysis of the expression of cyclins indicates that the phase of the cell cycle that is FIP sensitive resides somewhere beyond the restriction point of cyclin D2 (early to mid-G1) but prior to that of cyclins D3 and E (mid- to late G1). Finally, analysis of the expression of the proliferating cell nuclear antigen indicates that this is the earliest detectable defect in T cells exposed to FIP. We propose that if a block in the G1 phase of the cell cycle occurs in vivo in lymphocytes, it may result in a state of local and/or systemic immunosuppression. These suppressive effects could alter the nature and consequences of host-parasite interactions, thereby enhancing the pathogenicity of F. nucleatum itself or that of some other opportunistic organisms.     

Cortisol and catecholamines changes as functions of time-of-day and self-reported mood

Six male graduate students, unrestricted in their lifestyle, collected their own urine over a seven-day period: it was analysed for cortisol, noradrenaline, adrenaline and dopamine. At each urination subjects self-assessed their mood. On two separate days, blood samples were collected at 4-hourly intervals for plasma cortisol assay. Mean plasma cortisol levels showed the expected circadian variation, but two subjects had divergent patterns. Mean urine cortisol accumulation also showed circadian variation with a 2–4 hour lag behind plasma values. Mean urine catecholamine levels showed both time of day and considerable individual variation. A statistical procedure, involving comparison of two models, was developed to determine differences between subjects' excretion patterns. An underlying common pattern of cortisol and catecholamines excretion was found. Regression of hormone levels against self-assessed mood changes revealed correlations of (1) adrenaline accumulation with physical fatigue, (2) cortisol with alertness and (3) ratios of adrenaline, noradrenaline and dopamine with tenseness and irritability.     

Respiratory syncytial virus infections in northeastern Brazil: seasonal trends and general aspects

Respiratory syncytial virus (RSV) is one of the most prevalent agents of acute respiratory infections in children. Consistent data about seasonality of infections caused by this virus in Brazil proceed only from southern and southeastern regions. The purpose of this study was to determine the prevalence and the seasonal pattern of RSV infections in children living in Fortaleza city in northeastern Brazil. Nasopharyngeal aspirates of 1,950 patients attending in ambulatories, emergency room, and wards of Hospital Infantil Albert Sabin were collected and screened for RSV infections during 43 consecutive months. RSV was detected in 21% of the cases. RSV seasons in Fortaleza lasted 6 to 8 consecutive months, starting in January or February and finishing in July or August, and were associated with the rainy season.     

Russell Silver dwarfism

A rare case of Russell-Silver Syndrome, in a male child of 71/2 years, is reported. He presented with bilateral congenital cataract and correctopia, not mentioned in the literature so far.     

Optimization of Ultrasonic Extraction of Major Phenolic Components from Flowers of Ghav-Patta (Argyreia Speciosa Linn.) Via Response Surface Model

Pharmaceutical Chemistry Journal - Ultrasound-assisted extraction (UAE) or ultrasonic extraction technology has been used for the isolation of bioactive compounds from Argyreia speciosa (Linn. f.)...