Simultaneous assessment of blood coagulation and hematocrit levels in dielectric blood coagulometry.

BACKGROUND: In a whole blood coagulation test, the concentration of any in vitro diagnostic agent in plasma is dependent on the hematocrit level but its impact on the test result is unknown. OBJECTIVE: The aim of this work was to clarify the effects of reagent concentration, particularly Ca2+, and to find a method for hematocrit estimation compatible with the coagulation test. METHODS: Whole blood coagulation tests by dielectric blood coagulometry (DBCM) and rotational thromboelastometry were performed with various concentrations of Ca2+ or on samples with different hematocrit levels. DBCM data from a previous clinical study of patients who underwent total knee arthroplasty were re-analyzed. RESULTS: Clear Ca2+ concentration and hematocrit level dependences of the characteristic times of blood coagulation were observed. Rouleau formation made hematocrit estimation difficult in DBCM, but use of permittivity at around 3 MHz made it possible. The re-analyzed clinical data showed a good correlation between permittivity at 3 MHz and hematocrit level (R2=0.83). CONCLUSIONS: Changes in the hematocrit level may affect whole blood coagulation tests. DBCM has the potential to overcome this effect with some automated correction using results from simultaneous evaluations of the hematocrit level and blood coagulability.

The number of microvascular complications is associated with an increased risk for severity of periodontitis in type 2 diabetes patients: Results of a multicenter hospital-based cross-sectional study.

AIMS/INTRODUCTION: To explore the relationships between periodontitis and microvascular complications as well as glycemic control in type 2 diabetes patients. MATERIALS AND METHODS: This multicenter, hospital-based, cross-sectional study included 620 patients with type 2 diabetes. We compared the prevalence and severity of periodontitis between patients with ≥1 microvascular complication and those without microvascular complications. We also compared the prevalence and severity of periodontitis among patients with different degrees of glycemic control. RESULTS: After adjusting for confounding factors, multiple logistic regression analysis showed that the severity of periodontitis was significantly associated with the number of microvascular complications (odds ratio 1.3, 95% confidence interval 1.1-1.6), glycated hemoglobin ≥8.0% (64 mmol/mol; odds ratio 1.6; 95% confidence interval 1.1-2.3), and older age (≥50 years; odds ratio 1.7; 95% confidence interval 1.1-2.6). However, the prevalence of periodontitis was not significantly associated with the number of microvascular complications, but was associated with male sex, high glycated hemoglobin (≥8.0% [64 mmol/mol]), older age (≥40 years), longer duration of diabetes (≥15 years) and fewer teeth (≤25). Furthermore, propensity score matching for age, sex, diabetes duration and glycated hemoglobin showed that the incidence of severe periodontitis was significantly higher among patients with microvascular complications than among those without microvascular complications (P < 0.05). CONCLUSIONS: The number of microvascular complications is a risk factor for more severe periodontitis in patients with type 2 diabetes, whereas poor glycemic control is a risk factor for increased prevalence and severity of periodontitis.

Prediction of Venous Thromboembolism after Total Knee Arthroplasty Using Dielectric Blood Coagulometry.

BACKGROUND: Venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) frequently occurs in patients undergoing total knee arthroplasty (TKA). This study aimed to evaluate the efficacy of dielectric blood coagulometry (DBCM) as a new technique for predicting postoperative VTE. METHODS: Thirty patients undergoing TKA were enrolled. DVT was diagnosed by ultrasonography preoperatively and on the fourth or fifth postoperative day. Enhanced computed tomography was performed to detect PE on the fourth postoperative day. The day after surgery, a blood sample was measured by DBCM. All patients received fondaparinux or low-molecular-weight heparin for postoperative thromboprophylaxis. RESULTS: Eighteen of the 30 patients had DVT postoperatively, and 10 had asymptomatic PE. Seven patients had both DVT and PE. The patterns of permittivity as a function of time and frequency from the DBCM measurement were different between patients with and without VTE. The sensitivity and specificity of the parameter constructed from a set of permittivities at the frequencies of 2.5 kHz, 1 MHz, and 10 MHz were 90% and 78%, respectively. CONCLUSIONS: DBCM was effective and efficient for predicting VTE after TKA.

Effect of circulating tissue factor on hypercoagulability in type 2 diabetes mellitus studied by rheometry and dielectric blood coagulometry.

BACKGROUND: Hypercoagulability in type 2 diabetes mellitus (T2DM) patients increases their risk of cardiovascular diseases. OBJECTIVE: The aim of this work was to investigate the hypercoagulation mechanism in T2DM patients in terms of circulating tissue factor (TF). METHODS: Whole blood coagulation tests by damped oscillation rheometry and dielectric blood coagulometry (DBCM) were performed. RESULTS: The average coagulation time was significantly shorter for T2DM patients than for healthy controls. In vitro addition of either anti-TF or anti-activated factor VII (FVIIa) antibody to hypercoagulable blood samples prolonged coagulation times for one group of patients, while coagulation times remained short for another group. The levels of circulating TF were estimated in the former group by measuring the coagulation times for blood samples from healthy subjects with addition of various concentrations of TF and comparing them with the coagulation times for the group. The results indicated that the levels of circulating TF were on the order of subpicomolar at most. CONCLUSIONS: Circulating TF is at least partially responsible for a hypercoagulable group of T2DM patients, while an abnormality in the intrinsic coagulation pathway probably occurs in the other group.

Periodontal treatment with topical antibiotics improves glycemic control in association with elevated serum adiponectin in patients with type 2 diabetes mellitus.

OBJECTIVES: Chronic inflammation of periodontitis aggravates glycemic control in type 2 diabetic patients through aggravation of insulin resistance. Increased or decreased release of various inflammatory mediators, such as high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-6 and adipokines, such as adiponectin, leptin, and resistin, are presumed to be responsible for developing and progressing insulin resistance. The purpose of this study was to examine the effects of periodontal treatment on glycemic control, serum inflammatory mediators and adipokines in type 2 diabetes patients with periodontitis. METHODS: Twenty-one type 2 diabetic patients with periodontitis received periodontal treatment with topical antibiotics (intervention group) and 8 patients did not receive periodontal treatment (control group). Periodontal examination, including probing pocket depth (PPD) and bleeding on probing (BOP), and blood sampling were performed at baseline, 2 and 6 months after periodontal treatments. Glycated hemoglobin (HbA1c), hs-CRP, TNF-α, IL-6, adiponectin, leptin, and resistin were analyzed. RESULTS: In the intervention group, improvements of PPD and BOP, decrease in HbA1c and elevation of serum adiponectin were observed, while in the control group, all parameters were not changed. Generalized linear model revealed that changes of serum adiponectin and TNF-α and change of BOP correlated significantly with the reduction of HbA1c at 6 months after periodontal treatments. CONCLUSION: The results demonstrated that periodontal treatment improves periodontal status and glycemic control with elevation of serum adiponectin in type 2 diabetic patients. The results suggest that HbA1c is reduced by amelioration of insulin resistance due to elevated serum adiponectin after periodontal treatments.

Improvement of glycemic control after periodontal treatment by resolving gingival inflammation in type 2 diabetic patients with periodontal disease.

UNLABELLED: Aims/Introduction: Chronic inflammation aggravates glycemic control in patients with type 2 diabetes mellitus. An increase or decrease in the release and activities of various inflammatory mediators, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and C-reactive protein (CRP), are presumed to be responsible for inducing insulin resistance. The purpose of the present study was to examine the effects of non-surgical periodontal treatment incorporating topical antibiotics on glycemic control and serum inflammatory mediators in patients with type 2 diabetes mellitus with periodontitis. MATERIALS AND METHODS: Periodontal inflammation and periodontal tissue destruction were evaluated by bleeding on probing (BOP) and the probing pocket depth (PPD), respectively. A total of 41 patients with type 2 diabetes and periodontitis received periodontal treatment with the topical application of antibiotics four times within a 2-month period. A periodontal examination, including PPD and BOP, and venous blood sampling were carried out at baseline and at 2 and 6 months after periodontal treatment. Glycated hemoglobin (HbA1c), and serum levels of high-sensitivity (hs)-CRP, TNF-α and IL-6 were analyzed. RESULTS: A generalized linear model showed significant associations between the change in the HbA1c values at 6 months after periodontal treatment, and the change in the BOP, baseline TNF-α levels and the baseline mean PPD. CONCLUSIONS: As BOP is a marker of total gingival inflammation, these results suggest that non-surgical periodontal therapy with topical antibiotics in patients with mild periodontitis might improve glycemic control by resolving periodontal inflammation. Such treatments might be insufficient for the amelioration of insulin resistance in type 2 diabetic patients with severe periodontitis. This trial was registered with the University Hospital Medical Information Network (no. UMIN000006693). (J Diabetes Invest, doi: 10.1111/j.2040-1124.2012.00209.x, 2012).

Dielectric coagulometry: a new approach to estimate venous thrombosis risk.

We present dielectric coagulometry as a new technique to estimate the risk of venous thrombosis by measuring the permittivity change associated with the blood coagulation process. The method was first tested for a simple system of animal erythrocytes suspended in fibrinogen solution, where the coagulation rate was controlled by changing the amount of thrombin added to the suspension. Second, the method was applied to a more realistic system of human whole blood, and the inherent coagulation process was monitored without artificial acceleration by a coagulation initiator. The time dependence of the permittivity at a frequency around 1 MHz showed a distinct peak at a time that corresponds to the clotting time. Our theoretical modeling revealed that the evolution of heterogeneity and the sedimentation in the system cause the peak of the permittivity.

[Biorheological views of diabetic macroangiopathy].

Diabetes mellitus markedly increases the risk of myocardial infarction, stoke, amputation which cause most morbidity and mortality. Elevated low shear blood viscosity with erythrocyte aggregation and elevated high shear blood viscosity with reduced erythrocyte deformability might be important and potentially treatable factors in the etiology or progression of diabetic macroangiopathy. The metabolic abnormalities caused by diabetes induce both rheological changes of blood and vascular dysfunction that predisposes this patient population to atherosclerosis. Lowered shear stress and vortices with oscillatory shear stress induce atherosclerosis. Abnormalities in platelet function and increased blood coagulability may exacerbate the progression of atherosclerosis and the consequences of plaque rupture or erosion in diabetes.

Type 1 diabetes mellitus and drug-resistant epilepsy: presence of high titer of anti-glutamic acid decarboxylase autoantibodies in serum and cerebrospinal fluid.

A 55-year-old man who was diagnosed as having type 1 diabetes mellitus (DM) at the age of 50 years was started on insulin therapy. At 54 years old of age, he suddenly developed complex partial seizures, which frequently occurred despite intensive anti-epileptic drug therapy. Neurological examination on admission revealed hyporeflexia in bilateral upper and lower extremities without any muscle rigidity, painful spasm or cerebellar ataxia. Laboratory examination showed poor glycemic control with increased glycated hemoglobin levels. Positive anti-thyroglobulin antibodies and anti-thyroid peroxidase (TPO) antibodies and slight elevation of TSH levels are consistent with subclinical hypothyroidism due to Hashimoto's thyroiditis. A high titer of anti-glutamic acid decarboxylase (GAD) antibodies was detected in the patient's serum and cerebrospinal fluid (CSF). Electroencephalography showed temporal spikes, consistent with complex partial seizure. This is a very rare case presenting with concomitant type 1 diabetes and drug-resistant epilepsy associated with high titers of circulating and CSF anti-GAD antibodies.

A novel six-nucleotide insertion in exon 4 of the MEN1 gene, 878insCTGCAG, in three patients with familial insulinoma and primary hyperparathyroidism.

Three Japanese patients (a man and his two sons) in a family with clinical diagnosis of familial multiple endocrine neoplasia type 1 (MEN1) suffered from insulinoma(s), primary hyperparathyroidism and pituitary microadenoma. Genomic DNA of the patients was analyzed by sequencing for the MEN1 gene and an insertion of six nucleotides, CTGCAG, in exon 4, resulting in insertion of two amino acids, Leu-Gln, after the 256th amino acid of the menin (256insLQ), was identified. CTGCAG is a palindromic sequence and repeated twice in the wild-type allele (nucleotides 879-890). It is speculated that mutations involving only exon 4 of the MEN1 gene might induce development of insulinoma(s).

Expression of transcriptional repressor ATF3/LRF1 in human atherosclerosis: colocalization and possible involvement in cell death of vascular endothelial cells.

Vascular endothelial cell death contributes to the progression of atherosclerotic lesion, and several transcriptional regulators are involved in the process. Activating transcription factor 3/liver regenerating factor-1 (ATF3/LRF-1), a stress-inducible transcriptional repressor, was shown to be highly expressed in vascular endothelial cells and macrophages of human atherosclerotic lesions by immunohistological assay. The expression was colocalized in these cells which were positive for TdT-mediated dUTP nick-end labeling (TUNEL) and annexin V. Treatment of human umbilical vein endothelial cells (HUVECs) by tumor necrosis factor (TNF)-alpha, oxidized low density lipoprotein (oxLDL), and lysophosphatidylcholine (LPC) rapidly induced ATF3/LRF-1, which showed an increased DNA binding to the consensus ATF/CRE sequence by supershift of gel shift assay. Flow cytometry analysis and immunostaining analysis with TUNEL assay showed that ATF3/LRF-1 was highly expressed in cell death induced by these agents. Moreover, antisense ATF3/LRF-1 cDNA partly suppressed the cell death induced by TNF-alpha, oxLDL, and LPC. From these results, it is indicated that ATF3/LRF-1 is one of the immediate early response genes in vascular endothelial cells in response to atherogenic stimuli, and may play a role in the endothelial cell death associated with atherogenesis.