The early wear susceptibility of cementum, enamel and dentine in vitro.

OBJECTIVES: To assess the differential early wear susceptibility of cementum, enamel and dentine at a micron level. METHODS: Whole human molar buccal surfaces incorporating natural enamel and cementum (n = 20) confirmed by imaging (digital microscopy: Keyence, VHX-7000 Milton Keynes, UK), were mounted, scanned (profilometry: XYRIS 4000, Taicaan, Southampton, UK), and allocated to receive erosion (citric acid, pH 2.7, 30 min (n = 10)) or erosion/abrasion challenges (3 cycles of (citric acid, pH 2.7, 10 min, 60 300 g linear abrasion strokes), n=10). Samples were polished and the experiment repeated on polished enamel, and polished coronal and radicular dentine within the same tooth. Profilometric wear data were obtained using superimposition: GeoMagic (3Dsystems, Darmstadt, Germany) and subtraction: MountainsMap (DigitalSurf, Besancon, France). Data were normal. A general linear model was used to assess differences between groups and substrates. RESULTS: The mean step height (SD) for natural enamel was 8.82 µm (2.53) for erosion and 11.48 µm (2.95) for erosion/abrasion. For natural cementum, the mean step height was 6.00 µm (2.29) for erosion and 4.67 µm (1.58) for erosion/abrasion. Dentine step heights ranged from 7.20 µm (1.53) for erosion and 9.79 µm (1.01) for erosion/abrasion with no statistical differences in dentine wear. Natural cementum surfaces had the lowest wear (p<0.001). Dentine had significantly less wear than natural enamel (p<0.02). CONCLUSIONS: Cementum surfaces demonstrated the most wear resistance, followed by dentine under erosion dominant conditions in this in vitro study. Further in-vivo investigations are needed to confirm the intraoral stability of cementum. CLINICAL SIGNIFICANCE: Cementum may be the least susceptible of dental substrates to wear and dentine does not wear at a faster rate than enamel under erosive conditions. This adds to our knowledge on the development of non-carious cervical lesions and questions whether wear rates will accelerate once dentine is exposed.

Short Versions of the Arabic Psychosocial Impact of Dental Aesthetics Questionnaire for Yemeni Adolescents: Cross-Sectional Derivation and Validation.

Objectives: To shorten the 24-item Arabic Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ(A)) for adolescents in Yemen. Material and methods: Two shortening methods derived six-item and nine-item versions: the item impact method selected items with the highest impact scores as rated by 30 participants in each subscale; and the regression method was applied using data of 385 participants from the PIDAQ(A) validity study, with the total PIDAQ(A) score as the dependent variable, and its individual items as the independent variables. The four derived versions were assessed for validity and reliability. Results: The means of the six-item and nine-item short versions of both methods were close. Cronbach's alpha values extended from 0.90 to 0.92 (intra-class correlations = 0.85−0.88). In criterion validity, strong significant correlations were detected between scores of all short versions and the 24-item PIDAQ(A) score (0.96−0.98; p < 0.001). Construct validity displayed significant associations among all short versions and self-perceived dental appearance rank and self-perceived need for orthodontic braces rank (p < 0.05). Mean scores of all short versions were significantly different between adolescents with severe malocclusion and those with slight malocclusion in discriminant validity tests. In conclusion, all PIDAQ(A) short versions are valid and reliable.

Vanillin attenuates thioacetamide-induced renal assault by direct and indirect mediation of the TGFß, ERK and Smad signalling pathways in rats.

Inflammation and fibrosis are two pathological features of chronic kidney disease (CKD). Renal fibrosis is considered to be one of the most important conditions, as it may be the result of excessive extracellular matrix protein production and deposition, or prolonged exposure to nephrotoxic substances or drugs. Unfortunately, no suitable therapies or medications are currently available to prevent renal fibrosis. We conducted this study for the evaluation of the protective potential of vanillin by reversing TAA (250 mg/kg TAA for 6 weeks) induced renal injury in rats. The concentrations of the proteins tumour necrosis factor alpha (TNFα), interleukin-6 (IL-6), extracellular signal regulated kinase 1/2 (Erk1/2), and transforming growth factor beta-1 (TGF-ß1) in kidney tissues were assessed using ELISA. Kidney Injury Molecule-1 (KIM-1) and mothers against decapentaplegic homologue 2, 3 (SMAD 2, 3) expressions were evaluated using real time PCR. We also estimated the expression of α-smooth muscle actin (α-SMA) using immunohistochemistry. Treatment with vanillin (100 mg/kg) significantly ameliorated kidney Injury and improved the kidney function. Vanillin treatment also significantly decreased the malondialdehyde (MDA) content, and elevated glutathione peroxidase (GPx) and catalase (CAT) activities in kidney tissues. Vanillin also reduced α-SMA renal expression and TNFα, IL-6, TGF-ß1, and Erk1/2 renal levels. Vanillin significantly decreased the expression of the genes encoding KIM-1 and SMAD 2, 3 and ameliorated histological abnormalities in kidney architecture. Our molecular docking findings showed that vanillin has a good binding mode inside TGF-ß type I receptors (ALK5) biding site.

Validity and Reliability of the Arabic Version of the Psychosocial Impact of Dental Aesthetics Questionnaire for Yemeni Adolescents.

(1) Objectives: This paper aimed to cross-culturally adapt the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) into an Arabic language version (PIDAQ(A)) for measuring the oral health related quality of life related to dental aesthetics among 12-17-year-old Yemeni adolescents. (2) Material and methods: The study comprised three parts, which were linguistic validation and qualitative interview, comprehensibility assessment, and psychometric validations. Psychometric properties were examined for validity (exploratory factor analysis (EFA), partial confirmatory factor analysis (PCFA), construct, criterion, and discriminant validity) and reliability (internal consistency and reproducibility). (3) Results: The PIDAQ(A) contained a new item. EFA extracted three factors (item factor loading 0.375 to 0.918) comprising dental self-confidence, aesthetic concern, and psychosocial impact subscales. PCFA showed good fit statistics (comparative fit index (CFI) = 0.928, root-mean-square error of approximation (RMSEA) = 0.071). In addition, invariance across age groups was tested. Cronbach's α values ranged from 0.90 to 0.93 (intraclass correlations = 0.89-0.96). A criterion validity test showed that the PIDAQ(A) had a significant association with oral impacts on daily performance scores. A construct validity test showed significant associations between PIDAQ(A) subscales and self-perceived dental appearance and self-perceived need for orthodontic braces (p < 0.05). Discriminant validity presented significant differences in the mean PIDAQ(A) scores between subjects having severe malocclusion and those with slight malocclusion. No floor or ceiling effects were detected.

A dynamically young and perturbed Milky Way disk.

The evolution of the Milky Way disk, which contains most of the stars in the Galaxy, is affected by several phenomena. For example, the bar and the spiral arms of the Milky Way induce radial migration of stars1 and can trap or scatter stars close to orbital resonances2. External perturbations from satellite galaxies can also have a role, causing dynamical heating of the Galaxy3, ring-like structures in the disk4 and correlations between different components of the stellar velocity5. These perturbations can also cause 'phase wrapping' signatures in the disk6-9, such as arched velocity structures in the motions of stars in the Galactic plane. Some manifestations of these dynamical processes have already been detected, including kinematic substructure in samples of nearby stars10-12, density asymmetries and velocities across the Galactic disk that differ from the axisymmetric and equilibrium expectations13, especially in the vertical direction11,14-16, and signatures of incomplete phase mixing in the disk7,12,17,18. Here we report an analysis of the motions of six million stars in the Milky Way disk. We show that the phase-space distribution contains different substructures with various morphologies, such as snail shells and ridges, when spatial and velocity coordinates are combined. We infer that the disk must have been perturbed between 300 million and 900 million years ago, consistent with estimates of the previous pericentric passage of the Sagittarius dwarf galaxy. Our findings show that the Galactic disk is dynamically young and that modelling it as time-independent and axisymmetric is incorrect.

Influence of alendronate administration regimen on the final outcome of implant osseointegration in an osteoporotic model.

This study aimed to evaluate the bone response around titanium implants in osteoporotic rabbits receiving oral alendronate (ALN) for one month either simultaneously with implant placement (IP) or stopped immediately before surgery. Six weeks before IP, 34 adult female New Zealand white rabbits were submitted to intramuscular injections of dexamethasone (3 mg/kg twice a week) to induce osteoporosis-like conditions. Two animals were sacrificed and histological examinations of their leg bones were performed to confirm the osteoporosis-like condition, as compared to a healthy animal. The remaining 32 rabbits were then divided into four equal groups. Group I represented osteoporosis-like animals receiving implants. For Groups II, III and IV, osteoporosis-like animals received calcium phosphate cement before IP. Animals in Group II received implants without any systemic treatment for osteoporosis. In Group III, ALN was simultaneously started with IFP. In Group IV, ALN was stopped immediately before surgery. At 12 weeks post-surgery all animals were sacrificed. Both bone-implant interface and mineralized bone area percentage (MBA%) were microscopically evaluated. Group IV showed a significant gain in MBA% (p < 0.05), along with the most favorable implant integration outcome. Our results suggest that finishing an ALN course before implant placement could enhance the healing capacity around implants.

Prospects for detecting supersymmetric dark matter in the Galactic halo.

Dark matter is the dominant form of matter in the Universe, but its nature is unknown. It is plausibly an elementary particle, perhaps the lightest supersymmetric partner of known particle species. In this case, annihilation of dark matter in the halo of the Milky Way should produce gamma-rays at a level that may soon be observable. Previous work has argued that the annihilation signal will be dominated by emission from very small clumps (perhaps smaller even than the Earth), which would be most easily detected where they cluster together in the dark matter haloes of dwarf satellite galaxies. Here we report that such small-scale structure will, in fact, have a negligible impact on dark matter detectability. Rather, the dominant and probably most easily detectable signal will be produced by diffuse dark matter in the main halo of the Milky Way. If the main halo is strongly detected, then small dark matter clumps should also be visible, but may well contain no stars, thereby confirming a key prediction of the cold dark matter model.

Successful outcome after evacuation of intracranial hematoma following thrombolysis in acute myocardial infarction.

Thrombolytic therapy is the modality of choice for the treatment of life threatening thrombosis in various vascular territories and nowadays, is used extensively in setting of acute myocardial infarction. There is, however, the omnipresent danger of serious bleeding inherently associated with the use of all thrombolytics which if it occurs in the brain, can lead to potentially serious neurological impairment and even death. In our report, we describe the successful surgical management of a streptokinase-induced intracranial hemorrhage. Timely neurosurgical intervention is advocated as the optimal approach for this particular side effect of thrombolytic agents.

Successful outcome after evacuation of intracranial hematoma following thrombolysis in acute myocardial infarction.

Thrombolytic therapy is the modality of choice for the treatment of life threatening thrombosis in various vascular territories and nowadays, is used extensively in the setting of acute myocardial infarction. There is, however, the omnipresent danger of serious bleeding inherently associated with the use of all thrombolytics which if it occurs in the brain, can lead to potentially serious neurological impairment and even death. In our report, we describe the successful surgical management of a streptokinase-induced intracranial hemorrhage. Timely neurosurgical intervention is advocated as the optimal approach for this particular side effect of thrombolytic agents.

The contribution of adrenoceptor subtype(s) in the renal vasculature of diabetic spontaneously hypertensive rats.

1. Diabetes and hypertension are both associated with an increased risk of renal disease and are associated with neuropathies, which can cause defective autonomic control of major organs including the kidney. This study aimed to examine the alpha(1)-adrenoceptor subtype(s) involved in mediating adrenergically induced renal vasoconstriction in a rat model of diabetes and hypertension. 2. Male spontaneously hypertensive rats (SHR), 220-280 g, were anaesthetized with sodium pentobarbitone 7-day poststreptozotocin (55 mg x kg(-1) i.p.) treatment. The reductions in renal blood flow (RBF) induced by increasing frequencies of electrical renal nerve stimulation (RNS), close intrarenal bolus doses of noradrenaline (NA), phenylephrine (PE) or methoxamine were determined before and after administration of nitrendipine (Nit), 5-methylurapidil (5-MeU), chloroethylclonidine (CEC) and BMY 7378. 3. In the nondiabetic SHR group, mean arterial pressure (MAP) was 146+/-6 mmHg, RBF was 28.0+/-1.4 ml x min(-1) x kg(-1) and blood glucose was 112.3+/-4.7 mg x dl(-1), and in the diabetic SHR Group, MAP was 144+/-3 mmHg, RBF 26.9+/-1.3 ml(-1) min x kg(-1) and blood glucose 316.2+/-10.5 mg x dl(-1). Nit, 5-MeU and BMY 7378 blunted all the adrenergically induced renal vasoconstrictor responses in SHR and diabetic SHR by 25-35% (all P<0.05), but in diabetic rats the responses induced by RNS and NA treated with 5-MeU were not changed. By contrast, during the administration of CEC, vasoconstrictor responses to all agonists were enhanced by 20-25% (all P<0.05) in both the SHR and diabetic SHR. 4. These findings suggest that alpha(1A) and alpha(1D)-adrenoceptor subtypes contribute in mediating the adrenergically induced constriction of the renal vasculature in both the SHR and diabetic SHR. There was also an indication of a greater contribution of presynaptic adrenoceptors, that is, alpha(1B)-, and/or alpha(2)-subtypes.

Irreducible tuft fractures of the distal phalanx.

Two tuft fractures of the distal phalanx had a unique fracture pattern with significant displacement of the proximal fracture fragment into the pulp of the finger. Both fractures were irreducible by closed means, probably due to entrapment of bony spikes within the fibrous septa of the pulp or overlapping of the proximal and distal fracture fragments.

Evaluation of in vitro antibacterial activity of some disinfectants on Escherichia coli serotypes.

Three disinfectants commonly used in poultry farms (formalin, TH4+, and Virkon-S) were chosen for the present study. The effect of disinfectant concentration and the duration of exposure to these disinfectants on the survival of Escherichia coli serotypes (O114:K-, O86, O55:K39, and O86:K60) were investigated. Formalin (0.6%), TH4+ (0.06%), and Virkon (0.5%) all killed the four serotypes within 5 min of exposure. As the disinfectant concentration decreases, the length of exposure time to kill serotype increases. At 0.03%, 0.007%, and 0.03% of formalin, TH4+ and Virkon-S concentrations failed to kill the four E. coli serotypes within 360 min, respectively. An improvement of the inhibitory effect of these disinfectants occurred when added together with the inoculum instead of an established population. The influence of formalin, TH4+, and Virkon-S on the cell morphology of E. coli O55:K39 was investigated by using transmission electron microscopy. Formalin-treated cells exhibited normal cell morphology, with the exception that the treated cell was less fimbriated, and more destruction of pili increased when formalin concentrations were doubled. Cells treated with TH4+ (0.03%) showed destruction of the cell wall and cell surface membrane after 5 min. Cell filamentation occurred at 0.015% and increased with the increase of exposure time to this drug. Spheroplasts were observed only when cells were treated with 0.125% Virkon-S for 60 min, and cell lysis started to occur when 0.25% Virkon-S was applied for 15 min. Scanning electron microscope study revealed that Virkon-S at 0.03% and TH4+ at 0.007% completely prevented the adherence of E. coli O55:K39 serotype to chicken tracheal organ, whereas formalin (0.03%) disinfection minimized the adherence of E. coli cells to tracheal explants after 360 min of incubation.

Living-related liver transplantation in Africa.

Liver transplantation is an effective therapy for end stage liver disease. Nevertheless in many areas of the world organ availability remains a major problem. We report here the success of the first living-related liver transplantation in Africa. The left lateral lobe of the mother was transplanted orthotopically to her 6 year old child suffering from liver cirrhosis complicating glycogen storage disease. The social and medical problems encountered are discussed. Living-related liver transplantation is a viable option in countries where cadaveric organ donation is either illegal or socially unacceptable.

Therapeutic ultrasound and the liver in vivo: action and possible mechanisms.

This paper reports on the effects of therapeutic ultrasound upon the liver in vivo. Exposure of the liver of rats to therapeutic ultrasound at a frequency of 0.87 MHz results in intravascular haemolysis which is dependent upon the product of the intensity and the exposure duration (energy deposited within the liver). The resulting structural change (noted when a spatial peak intensity of 1.25 W/cm2 was applied for a duration of 10 min) is a lesion which has four zones. The severity of the injury increased across the four zones when scanning towards the ischaemic area. The biochemical changes observed included an increase in aspartate transaminase, alanine transferase, creatinine kinase and cholesterol and a decrease in total protein and albumin. Healing processes reversed the structural changes after 72 h which was also reflected in the plasma biochemical profile. Exposure of the liver to infrared radiation resulted in haemolysis but not the biochemical or structural alterations observed following sonication suggesting a mechanism for ultrasound action other than heating alone.

[Effects of neurectomy of the tympanic plexus on secretion of the parotid gland in man. Histopathological, histochemical and clinical study (author's transl)]. / Effets de la neurectomie du plexus tympanique sur la sécrétion de la glande parotide chez l'homme.

This study involved five patients suffering from bilateral chronic parotiditis and then with a persistent unilateral fistula of the parotid gland. Two types of parotid biopsy were examined: the first taken during surgery and the second six months later. All of the specimens underwent histopathological and histochemical investigations. Definitive degeneration and atrophic type changes were seen in all the parotid fragments removed six months after selective neurectomy of the tympanic plexus. Six months after surgery, all of the patients were cured.

Effect of tympanic neurectomy on human parotid salivary gland. Histopathologic, Histochemical, and Clinical Study.

Five patients with bilateral chronic recurrent parotiditis and ten patients with unilateral persistent paratoid gland fistulas underwent tympanic neurectomies. Two biopsy specimens from the diseased gland were examined. The first biopsy specimen was taken at the time of operation, while the second one was taken six months later. All specimens were subjected to both histopathologic and histochemical investigations. Definite degenerative and atrophic changes occured in all parotid gland specimens taken six months after selective tympanic neurectomy. All patients were completely cured at about that time. This supported the practical indication of the selective tympanic neurectomy for treating certain benign disorders or diseases of the parotid gland that require persistent arrest of the function of its secretory units.