The scientific basis and development of a matrix metalloproteinase (MMP) -8 specific chair-side test for monitoring of periodontal health and disease from gingival crevicular fluid

Matrix metalloproteinase (MMP) -8, collagenase-2, is a key mediator of irreversible tissue destruction in chronic periodontitis and detectable in gingival crevicular fluid (GCF). MMP-8 mostly originates from neutrophil leukocytes, the first line of defence cells which exist abundantly in GCF, especially in inflammation. MMP-8 is capable of degrading almost all extra-cellular matrix and basement membrane components and is especially efficient against type I collagen. Thus the expression of MMP-8 in GCF could be valuable in monitoring the activity of periodontitis and possibly offers a diagnostic means to predict progression of periodontitis. In this study the value of MMP-8 detection from GCF in monitoring of periodontal health and disease was evaluated with special reference to its ability to differentiate periodontal health and different disease states of the periodontium and to recognise the progression of periodontitis, i.e. active sites. For chair-side detection of MMP-8 from the GCF or peri-implant sulcus fluid (PISF) samples, a dip-stick test based on immunochromatography involving two monoclonal antibodies was developed. The immunoassay for the detection of MMP-8 from GCF was found to be more suitable for monitoring of periodontitis than detection of GCF elastase concentration or activity. Periodontally healthy subjects and individuals suffering of gingivitis or of periodontitis could be differentiated by means of GCF MMP-8 levels and dipstick testing when the positive threshold value of the MMP-8 chair-side test was set at 1000 µg/l. MMP-8 dipstick test results from periodontally healthy and from subjects with gingivitis were mainly negative while periodontitis patients sites with deep pockets ( 5 mm) and which were bleeding on probing were most often test positive. Periodontitis patients GCF MMP-8 levels decreased with hygiene phase periodontal treatment (scaling and root planing, SRP) and even reduced during the three month maintenance phase. A decrease in GCF MMP-8 levels could be monitored with the MMP-8 test. Agreement between the test stick and the quantitative assay was very good (κ = 0.81) and the test provided a baseline sensitivity of 0.83 and specificity of 0.96. During the 12-month longitudinal maintenance phase, periodontitis patients progressing sites (sites with an increase in attachment loss ≥ 2 mm during the maintenance phase) had elevated GCF MMP-8 levels compared with stable sites. General mean MMP-8 concentrations in smokers (S) sites were lower than in non-smokers (NS) sites but in progressing S and NS sites concentrations were at an equal level. Sites with exceptionally and repeatedly elevated MMP-8 concentrations during the maintenance phase were clustered in smoking patients with poor response to SRP (refractory patients). These sites especially were identified by the MMP-8 test. Subgingival plaque samples from periodontitis patients deep periodontal pockets were examined by polymerase chain reaction (PCR) to find out if periodontal lesions may serve as a niche for Chlamydia pneumoniae. Findings were compared with the clinical periodontal parameters and GCF MMP-8 levels to determine the correlation with periodontal status. Traces of C. pneumoniae were identified from one periodontitis patient s pooled subgingival plaque sample by means of PCR. After periodontal treatment (SRP) the sample was negative for C. pneumoniae. Clinical parameters or biomarkers (MMP-8) of the patient with the positive C. pneumoniae finding did not differ from other study patients. In this study it was concluded that MMP-8 concentrations in GCF of sites from periodontally healthy individuals, subjects with gingivitis or with periodontitis are at different levels. The cut-off value of the developed MMP-8 test is at an optimal level to differentiate between these conditions and can possibly be utilised in identification of individuals at the risk of the transition of gingivitis to periodontitis. In periodontitis patients, repeatedly elevated GCF MMP-8 concentrations may indicate sites at risk of progression of periodontitis as well as patients with poor response to conventional periodontal treatment (SRP). This can be monitored by MMP-8 testing. Despite the lower mean GCF MMP-8 concentrations in smokers, a fraction of smokers sites expressed very high MMP-8 concentrations together with enhanced periodontal activity and could be identified with MMP-8 specific chair-side test. Deep periodontal lesions may be niches for non-periodontopathogenic micro-organisms with systemic effects like C. pneumoniae and possibly play a role in the transmission from one subject to another.

Unsteady nonsimilar natural convection over a vertical flat plate in a thermally stratified fluid

Abstract is not available.

The level of FoxO1 and IL-15 in skeletal muscle, serum and synovial fluid in people with knee osteoarthritis: a case control study

Objectives Impaired muscle function is common in knee osteoarthritis (OA). Numerous biochemical molecules have been implicated in the development of OA; however, these have only been identified in the joint and serum. This study compared the expression of interleukin (IL-15) and Forkhead box protein-O1 (FoxO1) in muscle of patients with knee OA asymptomatic individuals, and examined whether IL-15 was also present in the joint and serum. Method Muscle and blood samples were collected from 19 patients with diagnosed knee OA and 10 age-matched asymptomatic individuals. Synovial fluid and muscle biopsies were collected from the OA group during knee replacement surgery. IL-15 and FoxO1were measured in the skeletal muscle. IL-15 abundance was also analysed in the serum of both groups and synovial fluid from the OA group. Knee extensor strength was measured and correlated with IL-15 and FoxO1 in the muscle. Results FoxO1 protein expression was higher (p=0.04), whereas IL-15 expression was lower (p=0.02) in the muscle of the OA group. Strength was also lower in the OA group, and was inversely correlated with FoxO1 expression. No correlation was found between IL-15 in the joint, muscle or serum. Conclusion Skeletal muscle, particularly the quadriceps, is affected in people with knee OA where elevated FoxO1 protein expression was associated with reduced muscle strength. While IL-15 protein expression in the muscle was lower in the knee OA group, no correlation was found between the expression of IL-15 protein in the muscle, joint and serum, which suggests that inflammation is regulated differently within these tissues.

Fluid dynamics of the monsoon

The monsoonal regions of the world are characterized by a seasonal reversal in the direction of winds associated with the excursion of the equatorial trough (or the ITCZ) in response to the variation in the latitude of maximum insolation. This monsoonal circulation is a planetary scale phenomenon. However, the associated precipitation is critically dependent on the organization of the cumulus clouds (typically a few kilometers in horizontal extent) over the scale of synoptic vortices (typically a few hundred kilometers in horizontal extent). Thus modelling of the seasonal transitions and intraseasonal fluctuations requires an understanding of the fluid mechanics of these three scales of organizations and their interactions. The present paper is an attempt to outline the current state of understanding of these phenomena.

Real-fluid effects in flow cavitation

The possible role of reaj fluid effects in two aspects of flow cavitation namely inception and separation is discussed. This is primarily qualitative in the case of inception whereas some quantitative results are presented in the case of separation. Existing evidence clearly indicates that in particular viscous effects can play a significant role in determining the conditions for cavitation inception and in determining the location of cavitation separation from smooth bodies.

The harmonic torsional oscillations of a thin disk submerged in a fluid with a surfactant surface layer

A formulation in terms of a Fredholm integral equation of the first kind is given for the axisymmetric problem of a disk oscillating harmonically in a viscous fluid whose surface is contaminated with a surfactant film. The equation of the first kind is converted to a pair of coupled integral equations of the second kind, which are solved numerically. The resistive torque on the disk is evaluated and surface velocity profiles are computed for varying values of the ratio of the coefficient of surface shear viscosity to the coefficient of viscosity of the substrate fluid, and the depth of the disk below the surface.

Nonsimilar laminar natural convection in a thermally stratified fluid

Abstract is not available.

Flow of a micropolar fluid in a tube with sinusoidal deformation

The flow of a micropolar fluid for sinusoidally deforming boundaries is discussed in detail. The velocity and microrotation fields and the streamfunction are determined and plotted under the assumption of small deformations.

Pulsatile flow in tubes of varying cross-sections

The pulsatile flow of an incompressible viscous fluid in a cylindrical tube of varying cross section is investigated for small Reynolds numbers. The solutions consist of a stedy and an oscillatory part. The shear stress distribution on the wall is evaluated and discussed in detail for special geometries like tapered tubes, locally constricted tubes and peristaltic tubes. The existence of separation in the flow field is noticed.

Unsteady Motion of a Stratified Rotating Viscous Fluid between Two Disks

Abstract is not available.

A note on the application of a radiation condition for a source in a rotating stratified fluid

The motion due to an oscillatory point source in a rotating stratified fluid has been studied by Sarma & Naidu (1972) by using threefold Fourier transforms. The solution obtained by them in the hyperbolic case is wrong since they did not make use of any radiation condition, which is always necessary to get the correct solution. Whenever the motion is created by a source, the condition of radiation is that the sources must remain sources, not sinks of energy and no energy may be radiated from infinity into the prescribed singularities of the field. The purpose of the present note is to explain how Lighthill's (1960) radiation condition can be applied in the hyperbolic case to pick the correct solution. Further, the solution thus obtained is reiterated by an alternative procedure using Sommerfeld's (1964) radiation condition.

In vitro degradation of hepatotoxic indospicine in indigofera spicata by camel foregut fluid

Indospicine toxicosis was reported in sheep, goats and cattle fed on Indigofera, a leguminous plant rich in indospicine. Recent death report on dogs as a result of dietary ingestion of indospicine contaminated camel meat has raised concern about the distribution of this toxin in camels fed on Indigofera. This in vitro study aimed at measuring the degradability of indospicine in Indigofera spicata by camel-foregut fluid and attempted at explaining indospicine accumulation in meat tissue. In the first experiment, in vitro dry matter digestibility and indospicine disappearance were evaluated by using foregut fluid from 15 feral camels. Foregut fluid was collected post mortem from a nearby abattoir. In the second experiment, a composite foregut fluid obtained from three feral camels was used to examine the time-dependent degradation of indospicine. Results indicated that 99 of the dietary indospicine was degraded after 48 h of incubation. The time-dependent degradation study showed rapid degradation (11 µg/h) during the first 18 h of incubation, followed by a much slower rate (2 µg/h) between 18-48 h. Results demonstrated the ability of the camel microbiota to degrade indospicine and suggest the presence of a by-pass mechanism that enables the toxin to escape degradation and reaches the intestine.

Magnetohydrodynamic flow between torsionally oscillating eccentric disks

The unsteady MHD flow of an incompressible, viscous electrically conducting fluid contained between two torsionally oscillating eccentric disks has been investigated. The state of uniform rotation of the central region visualised in the steady flow is seen to be absent in the case of oscillatory flow.