Dental Pulp Vascular Response to Early Stages of Caries.

OBJECTIVES: During caries progression, dental pulp is increasingly pathologically affected. Since the accurate assessment of pulp is of vital importance in clinical decision-making, this study aimed to evaluate pulpal condition in the early stages of caries via laser Doppler (LD) flowmetry and histologic analysis and determine their agreement. METHODS: Fourteen patients with severe dental crowding were included. Prior to extractions and orthodontic treatment, dental pulp condition of 52 premolars was evaluated via LD flowmetry. Teeth were assessed for the presence of caries and lesions were graded according to the International Caries Detection and Assessment System (ICDAS). After extractions, teeth were split and histologically stained for endothelial cells with anti-von Willebrand factor and Movat pentachrome for collagen. Volume densities of vessels (Vvasc) and collagen were calculated. RESULTS: There was a significant negative correlation between LD flow and Vvasc of the dental pulp with ICDAS grade. Pulpal LD flow and Vvasc in teeth with the initial lesion were increased, decreasing with progressing stages of caries. A significant positive correlation between the the pulpal LD flow and Vvasc, and a negative correlation of LD flow with collagen fibre density were noted. CONCLUSIONS: Caries affects the physiology of the dental pulp, initially with increasing vascularity, and decreasing vascularity at later stges of caries progression. Collagen contents increase with grades of ICDAS. LD flow shows good agreement with the histologic constitution of the dental pulp. Use of clinical measurements of pulpal LD flow could provide a good noninvasive indication of pulpal vascular state and its health.

Improving Diastolic and Microvascular Function in Heart Transplantation with Donation after Circulatory Death.

The impact of the machine perfusion of donation after circulatory death (DCD) hearts with the novel Custodiol-N solution on diastolic and coronary microvascular dysfunction is unknown. Porcine DCD-hearts were maintained four hours by perfusion with normothermic blood (DCD-B), hypothermic Custodiol (DCD-C), or Custodiol-N (DCD-CN), followed by one hour of reperfusion with fresh blood, including microvascular and contractile evaluation. In another group (DCD group), one hour of reperfusion, including microvascular and contractile evaluation, was performed without a previous maintenance period (all groups N = 5). We measured diastolic function with a balloon catheter and microvascular perfusion by Laser-Doppler-Technology, resulting in Laser-Doppler-Perfusion (LDP). We performed immunohistochemical staining and gene expression analysis. The developed pressure was improved in DCD-C and DCD-CN. The diastolic pressure decrement (DCD-C: -1093 ± 97 mmHg/s; DCD-CN: -1703 ± 329 mmHg/s; DCD-B: -690 ± 97 mmHg/s; p < 0.05) and relative LDP (DCD-CN: 1.42 ± 0.12; DCD-C: 1.11 ± 0.13; DCD-B: 1.22 ± 0.27) were improved only in DCD-CN. In DCD-CN, the expression of eNOS increased, and ICAM and VCAM decreased. Only in DCD-B compared to DCD, the pathways involved in complement and coagulation cascades, focal adhesion, fluid shear stress, and the IL-6 and IL-17 pathways were upregulated. In conclusion, machine perfusion with Custodiol-N improves diastolic and microvascular function and preserves the microvascular endothelium of porcine DCD-hearts.

The effect of inferior alveolar nerve block anesthesia of 4% articaine and epinephrine 1:100,000 on blood flow and anesthesia of human mandibular teeth.

BACKGROUND/PURPOSE: Local anesthetics and anesthetic techniques affect the patterns of pulpal blood flow (PBF) and pulpal anesthesia in human teeth. This study aimed to determine PBF changes and pulpal anesthesia of intact mandibular first molars and canines after administration of 4% articaine with epinephrine 1:100,000 using inferior alveolar nerve block (IANB). MATERIALS AND METHODS: Ten healthy subjects received IANB of 4% articaine with epinephrine 1:100,000. Laser Doppler flowmetry and electrical pulp testing were combined to assess PBF changes and pulpal anesthesia of intact mandibular first molars and canines. The data were analyzed using one-way repeated-measures analysis of variance and Student-Newman-Keuls test. RESULTS: IANB with 4% articaine and epinephrine 1:100,000 did not have any significant change in PBF for the first 20 min post injection in mandibular first molars, and for 45 min post injection in the canines (P > 0.05). However, a hyperemic response occurred during 25-60 min post injection in the molars, and between 60 and 75 min post injection in the canines (P < 0.05). Thereafter, the PBF in both teeth returned to the baseline. Onset of pulpal anesthesia was 8.60 ±â€¯2.12 min in the molars, and 9 ±â€¯1.94 min in the canines. Duration of pulpal anesthesia was 82.40 ±â€¯41.56 min in the molars, and 84 ±â€¯47.40 min in the canines. CONCLUSION: In case of successful IANB, 4% articaine and epinephrine 1:100,000 caused insignificant changes in PBF up to 30 min but a hyperemic response at later time points. Thereafter, the PBF returned to the baseline.

Gingival crevicular fluid levels of cytokine, chemokine, and growth factors in patients with periodontitis or gingivitis and periodontally healthy subjects: a cross-sectional multiplex study.

INTRODUCTION: Gingival crevicular fluid (GCF) is an important resource for detecting inflammatory biomarkers related to periodontal disease. The purpose of this research was to identify the possible relation between cytokine levels and periodontal status. MATERIAL AND METHODS: GCF samples collected from 25 periodontally healthy individuals, 24 with gingivitis, and 24 with periodontitis were analyzed using the MAGPIX system with a Bio-Plex Pro Human Cytokine 27-plex kit. Gingival index (GI), periodontal pocket depth (PPD), plaque index (PI), and clinical attachment level (CAL) were measured from each tooth to determine each patient's periodontal status. RESULTS: All clinical parameters showed statistically significant differences between groups. While interleukin (IL)-1ß, IL-6, macrophage chemotactic protein 1 (MCP-1), interferon γ-induced protein 10 (IP-10) and vascular endothelial growth factor (VEGF) levels were statistically significantly higher in patients with periodontitis compared to periodontally healthy subjects, IL-15 levels were found to be statistically significantly higher in periodontally healthy individuals compared to periodontitis (p < 0.05). Also, IL-1ß and IP-10 showed positive correlations with PPD, CAL, GI and bleeding on probing (BOP). CONCLUSIONS: It is considered that IL-1ß, IL-6, IL-15, MCP-1, VEGF and IP-10 could be related to periodontal disease and health and can be used as an adjunct to clinical examination in future research design. Scanning cytokines in GCF with a multiplex immunoassay technique is consequential, especially because many cytokine types are found in one sample.

No effect of the angiotensin receptor blocker candesartan on cerebrovascular autoregulation in rats during very high and low sodium intake.

Autoregulation of cerebral blood flow (CBF) denotes that CBF is constant despite fluctuation of blood pressure within wide limits. Inhibition of the renin-angiotensin system (RAS) is known to decrease the lower and upper limits of CBF autoregulation. We have previously shown that this includes inhibition by the angiotensin receptor blocker (ARB) candesartan. In the present study we investigated the influence of the ARB candesartan on the lower limit of CBF autoregulation in two groups of Sprague-Dawley rats, on high (4.0% Na+) and low (0.004% Na+) sodium diet, respectively. Control animals were given the same diet, but no ARB. CBF was studied with the laser Doppler method. Blood pressure was lowered by controlled bleeding. Results revealed that both high and low sodium diet with low and high renin levels respectively block the influence of candesartan on CBF autoregulation. This was expected in rats on a high salt diet with a low renin level, but unexpected in rats with a low salt intake with a high renin level.

Cutaneous microcirculation during operations with a cardiopulmonary bypass.

BACKGROUND: Cutaneous microcirculation (cMC) is influenced by many factors. In cardiac surgery, most operations are performed with a cardiopulmonary bypass (CPB) and cardiac arrest induced by cardioplegic solutions. OBJECTIVES: Aim of this study was to examine a correlation between cMC and hemodynamic parameters in patients undergoing heart surgery with two different cardioplegic solutions. METHODS: 20 patients were included and divided into Histidine-Tryptophane-α-Ketoglutarate solution- (HTK, n = 10) and blood cardioplegia- (BCP, n = 10) groups. With initiation of CPB, cMC was continuously monitored with Laser-Doppler-Perfusion (LDP) until termination of CPB. Additionally, we measured hemoglobin-concentration (HbC) with a Blood-Parameter-Monitoring-System. RESULTS: LDP pulsation was almost equal before and after CPB and decreased during aortic cross clamping. The following factors influenced LDP: central venous pressure (CVP), mean arterial pressure (MAP), total peripheral resistance (TPR) and flow of the heart-lung machine. We measured relative LDP and HbC (RLDP; RHbC). Five and 25 min after administration of cardioplegia, RLDP (1.22±0.8; 1.17±0.94) and RHbC (0.92±0.06; 0.96±0.09) in the HTK-group were lower than in the BCP-group: RLDP (1.58±1.11; 1.58±2.2) and RHbC (1.00±0.05; 0.99±0.13). HTK-patients with a body surface area (BSA) <2 m2 showed a lower RLDP (0.75±0.50), than patients over 2 m2 (RLDP = 1.64±0.97). CONCLUSIONS: The cMC is influenced by CPB. Cutaneous LDP monitoring is a non-invasive method, for estimating hemodynamics intraoperatively.

Pulpal blood flow recorded from exposed dentine with a laser Doppler flow meter using red or infrared light.

OBJECTIVE: To determine the percentage of the blood flow signal that is derived from dental pulp when recording from exposed dentine in a human premolar. DESIGN: Recordings were made from 7 healthy teeth in 5 subjects (aged 22-33 yr.) with a laser Doppler flow meter (Periflux 4001) using either a red (635 nm) or an infrared (780 nm) laser. After exposing dentine above the buccal pulpal horn (cavity diam. 1.6 mm, depth 3 mm) and isolating the crown with opaque rubber dam, blood flow was recorded alternately with infrared or red light from the exposed dentine under four conditions: before and after injecting local anaesthetic (3% Mepivacaine without vasoconstrictor) (LA) over the apex of the root of the tooth; after exposing the pulp by cutting a buccal, class V cavity in the tooth; and after sectioning the coronal pulp transversely through the exposure. RESULTS: There was no significant change in mean blood flow recorded with either light source when the tooth was anaesthetized or when the pulp was exposed. After the pulp had been sectioned, the blood flow recorded with infrared light fell by 67.8% and with red light, by 68.4%. The difference between these effects was not significant. CONCLUSIONS: When recording blood flow from exposed coronal dentine with either infrared or red light in a tooth isolated with opaque rubber dam, about 68% to the signal was contributed by the pulp. The signal:noise ratio was better with infrared than red light, and when recording from dentine than enamel.

Cutaneous microvascular reactivity and aortic elasticity in coronary artery disease: Comparison of the laser Doppler flowmetry and echocardiography.

BACKGROUND AND AIM: Decreased vascular reactivity in atherosclerosis was previously shown. In our study, it was aimed to demonstrate the decreased vascular functions in both microvascular and macrovascular tissues and to estimate any correlation between them. METHODS: Twenty-five control outpatients with no coronary artery disease (CAD) history and 26 outpatients with CAD history were enrolled in the study. Local cutaneous post-occlusive reactive hyperemia (PORH) responses after three minutes of brachial occlusion with a pneumatic cuff were recorded noninvasively by a Perimed Periflux 5010 laser Doppler flow system. Aortic distensibility and stiffness indexes were recorded noninvasively by a two-dimensional Doppler echocardiography machine (Vivid S6 GE Medical System, Horten, Norway). RESULTS: Except for the medication history of subjects, there were no significant demographic differences between the CAD and control groups. Peak flow (PF), resting flow (RF) and biological zero(BZ) laser Doppler measurements were not decreased, but PF-RF/RF (%), PF-BZ/BF (%), hyperemia repayment and PORH indexes were significantly decreased in the CAD group (P=0.005, P=0.024, P=0.017, P=0.006, respectively) with laser Doppler measurements. Aortic strain (%) and aortic distensibility (cm3/dyn-1) measurements were significantly decreased in the CAD group (P=0.005, P=0.013). However, there was no correlation between microvascular indexes (hyperemia repayment index, PORH index) and macrovascular indexes (aortic strain and aortic distensibility). DISCUSSION: Different corrupted vascular tonus regulator systems in arteries of varying diameter, different major reactive responses to the stimuli or, finally, the lack of a number of subjects to obtain a significant level may be responsible for the irrelevant correlation analysis. CONCLUSION: The differences in arterial beds (both aorta and microcirculation) may be examined to assess the cardiovascular risk in patients with history of CAD.

Effects of enamel and dentine thickness on laser Doppler blood-flow signals recorded from the underlying pulp cavity in human teeth in vitro.

OBJECTIVE: To determine the effect of enamel and dentine thickness on laser Doppler blood-flow (LDF) signals recorded from dental pulp. DESIGN: Observations were made on 18 human premolars that had been extracted from young patients during orthodontic treatment. The apical 2/3 of the root was cut off and the remaining pulp removed. Blood flow signals were recorded from the buccal surface of the crown with a laser Doppler flow metre while dilute blood was pumped at 10 ml/min. through a cannula inserted into the pulp cavity. Recordings were made from the enamel surface and at 0.5 mm steps through the enamel and dentine. RESULTS: The blood flow signal increased significantly as the cavity depth increased and at 2.0 mm, the median flux signal was more than ten times greater than that obtained on the enamel surface. The backscattered light intensity did not change with cavity depth. CONCLUSION: When recording pulpal blood flow from a human tooth with a laser Doppler flow metre, a substantially better signal-to-noise ratio should be obtained by placing the probe on dentine in the floor of a cavity than on the enamel surface.

Contributions of endothelial nitric oxide synthase, noradrenaline, and neuropeptide Y to local warming-induced cutaneous vasodilatation in men.

We performed a two-part study to determine the roles of endothelial nitric oxide synthase (eNOS) and the vasoconstrictor nerves neurotransmitters noradrenaline (NA) and neuropeptide Y (NPY) in the cutaneous vasodilator response to local skin warming. Forearm skin sites were instrumented with intradermal microdialysis fibres, local heaters, and laser-Doppler flow (LDF) probes. Sites were locally heated from 34 to 42°C. LDF was expressed as cutaneous vascular conductance (CVC; LDF/mean arterial pressure). In Part I, we tested whether sympathetic noradrenergic nerves acted via eNOS. In 8 male participants, treatments were as follows: 1) untreated; 2) bretylium tosylate (BT), preventing sympathetic neurotransmitter release; 3) l-NAA to inhibit eNOS; and 4) combined BT+l-NAA. At treated sites, the initial peak response was markedly reduced, and the plateau phase response to 35min of local warming was also reduced (P<0.05), which was not different among those sites (P>0.05). In Part II, we tested whether NA and NPY were involved in the vasodilator response to local warming. In Part IIa, treatments were: 1) untreated; 2) propranolol and yohimbine to antagonize α- and ß-receptors; 3) l-NAA; and 4) combined propranolol, yohimbine, and l-NAA. In Part IIb, conditions were: 1) untreated; 2) BIBP to antagonize Y1-receptors; 3) l-NAA; and 4) combined BIBP and l-NAA. All treatments caused a reduction in the initial peak and plateau responses to local skin warming (P<0.05). The results of Part II indicate that both NA and NPY play roles in the cutaneous vasodilator response and their actions are achieved via eNOS. These data indicate that NA and NPY are involved in the initial, rapid rise in skin blood flow at the onset of local skin warming. However, their vasodilator actions in response to local skin warming appears to be manifested through eNOS.

Huang-Lian-Jie-Du-Decotion induced protective autophagy against the injury of cerebral ischemia/reperfusion via MAPK-mTOR signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Huang-Lian-Jie-Du-Decotion (HLJDD, Hwangryun-Hae-Dok-Decotion in Japan), an ancient antipyretic and detoxifying traditional Chinese medicine formula, was reported to have protective effect on ischemic stroke. AIM OF THE RESEARCH: To investigate the therapeutic effect of HLJDD on ischemic stroke and explore its mode of action. MATERIAL AND METHODS: A model of ischemic stroke in the rat was established after transient middle cerebral artery occlusion (MCAO) followed by reperfusion. Rats were assigned randomly to groups of control, sham, transient ischemia/reperfusion (I/R), and three treatment groups by HLJDD at 2.5, 5.0, 10.0mg/kg. The neurological deficit, the cerebral infarct size, morphology abnormality, biochemical parameters were examined, and the levels of relevant proteins were determined by immunoblotting analysis to evaluate the protective effects of HLJDD on ischemic stroke and explore the underlying mechanism. RESULTS: Compared with I/R group, HLJDD significantly ameliorated neurological deficit and histopathology changes, decreased infarct area, and restored the levels of biochemical indicators including nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), glutathione disulfide (GSSG), total superoxide dismutase (T-SOD), Cu/Zn-SOD, Mn-SOD and glutathione peroxidase (GSH-PX). HLJDD also notably elevated the levels of microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, and other autophagy related genes (Atgs), promoted the activation of extracellular signal-regulated kinases (ERK), protein kinase B (Akt), 3-phosphoinositide-dependent kinase (PDK1), and inhibited the activation of mammalian target of rapamycin (mTOR), c-Jun N-terminal protein kinases (JNK), p38, phosphatase and tensin homolog (PTEN). CONCLUSION: HLJDD showed neuroprotective effects on ischemic stroke, at least in part to the induced protective autophagy via the regulation of mitogen-activated protein kinase (MAPK) signals. This Akt-independent protective autophagy is favorable in the treatment of stroke, avoiding unfavorable side-effects associated with the inactivation of Akt. The efficacy of HLJDD on ischemic stroke and its safety warranted by its long-term clinical use in traditional Chinese medicine favored further study to develop HLJDD as an effective therapeutic agent to treat ischemic stroke.

Intraperitoneal 1.5% Delflex improves intestinal blood flow in necrotizing enterocolitis.

BACKGROUND: Necrotizing enterocolitis (NEC) alters intestinal microvascular control mechanisms causing significant vasoconstriction. Our prior work with intraperitoneal 2.5% dextrose solution demonstrated increased intestinal perfusion in experimentally induced NEC. In the current study, we examine whether a buffered solution with lower glucose and osmolar loads similarly increases intestinal blood flow. We hypothesized that buffered 1.5% dextrose solution would increase ileal blood flow compared with baseline in NEC. METHODS: We randomly assigned pregnant Sprague-Dawley rats to control (n = 103) or NEC (n = 123) groups, by litter. We induced NEC by previously published methods. Control pups were vaginally delivered and dam-fed. We used laser Doppler flowmetry to evaluate perfusion in the terminal ileum at 12, 24, 48, 72, or 96 h after delivery at baseline and after application of topical 1.5% dextrose solution. We evaluated differences between groups and time points by analysis of variance and Tukey post hoc test. RESULTS: Baseline blood flow in the terminal ileum increased with gestational age in both groups (P < 0.05). Control groups had significantly greater baseline blood flow than NEC groups (P < 0.05), and topical application of buffered 1.5% dextrose solution increased blood flow compared with baseline in both groups at all time points (P < 0.05). CONCLUSIONS: Topical 1.5% dextrose solution significantly enhanced blood flow in the terminal ileum to the same degree as 2.5% dextrose solution. Thus, the use of buffered 1.5% dextrose solution might be more beneficial in treating clinical NEC, because it places a lower glucose and osmotic load on NEC-injured intestine.