The Forgotten Variable of Shear Stress in Mitral Annular Calcification: Whole Blood Viscosity

Objective

The aim of this research was to assess the relationship between mitral annular calcification (MAC) and whole blood viscosity (WBV).

Subjects and Methods

A total of 184 patients with MAC and 133 patients without MAC were enrolled in the study. The WBV was calculated with a confirmed formulation using the hematocrit and total plasma protein at a low shear rate (LSR) and high shear rate (HSR). Early diastolic mitral annular velocity (Ea) and late diastolic mitral annular velocity (Aa) were measured using pulse Doppler tissue echocardiography. Pearson''s correlation analysis was performed to assess the relationship between WBV and mitral annular motion velocities. The effects of different variables on the occurrence of MAC were assessed in univariate and multivariate logistic regression analysis.

Results

In patients with MAC, WBV values were significantly higher at HSR (18.04 ± 0.84 vs. 17.25 ± 0.96 208 s^-1, p < 0.001) and at LSR (78.0 ± 14.2 vs. 61.9 ± 17.1 0.5 s^-1, p < 0.001). The WBV at HSR and LSR were significantly correlated with Ea (r = −0.477, p < 0.001; r = −0.385, p < 0.001, respectively) and Aa (r = −0.544, p < 0.001; r = −0.323, p < 0.001, respectively). Multivariate analysis showed that WBV of both shear rates was an independent predictor of MAC. Using the ROC curve, a cut-off value of 70.1 for WBV at LSR had a sensitivity of 83.7% and a specificity of 73.7% (AUC 0.785, p < 0.001) and a WBV cut-off value of 17.5 at HSR had a sensitivity of 79.6% and a specificity of 71.4% (AUC 0.761, p < 0.001) for the prediction of MAC.

Conclusion

Patients with MAC had significantly higher WBV, which independently predicted the presence of MAC. WBV had an inverse correlation with mitral annular motion velocities, indicating that a higher WBV may lead to greater limitation in annular motion and, thus, more calcification.Key Words: Mitral valve calcification, Shear stress, Blood viscosity     

Prevalence of hepatitis B infection in the southeastern region of Turkey: comparison of risk factors for HBV infection in rural and urban areas

Although hepatitis B has been well studied, there are still aspects of its epidemiology that remain to be clarified. There are many regions with high seroprevalence, particularly in the developing regions of the world, and these regions are known to have different epidemiologic patterns. Nonetheless, there are currently no data on the differences in hepatitis B seroprevalence between urban and rural areas of Turkey. In the present study, therefore, we used 30-cluster sampling to determine and compare the prevalence of hepatitis B in the urban and rural areas of the least developed region of Turkey, the southeastern region. From 2,888 adults living in the region, blood samples were obtained from house visits, and screened for HBsAg, anti-HBs, and anti-HBcIgG. Factors associated with hepatitis B seroprevalence, particularly living in rural areas, were analyzed with multivariate methods. The seroprevalence of HBsAg was 8.2% in the rural and 6.2% in the urban areas. There was a statistically significant difference between urban and rural regions in terms of HBsAg positivity (crude OR: 0.74; 95% CI: 0.55 - 0.98). Exposure to hepatitis B virus (HBV) increased with age both in urban and rural areas. Lower education level was also an important risk factor for hepatitis B seropositivity in urban areas (adjusted OR: 1.66; 95% CI: 1.26 - 2.19) but not in rural ones (adjusted OR: 0.77; 95% CI: 0.36 - 1.69). Familial jaundice history was a statistically significant risk factor for HBsAg positivity in rural areas (adjusted OR: 2.15; 95% CI: 1.30 - 3.56) but not in urban ones (adjusted OR: 1.48; 95% CI: 0.96 - 2.27). This study shows that the prevalence of HBV infection in the southeastern region of Turkey is intermediate among the levels reported for the European region of the World Health Organization.     

Laparoscopic vs open complete mesocolic excision with central vascular ligation for right-sided colon cancer

Complete mesocolic excision (CME) is being performed more frequently and has recently become an established oncologic surgical method for right hemicolectomy. Despite its advantages, such as its association with early mobilization, a short hospital stay, early bowel movement, mild postoperative pain, and good cosmesis, CME is technically demanding and carries the risk of severe complications. This study aims to compare the clinical, pathological, and oncological results of open and laparoscopic right hemicolectomy with CME.The data of 76 patients who underwent right hemicolectomy with CME and high vascular ligation were reviewed retrospectively. The patients were divided into 2 groups according to whether the open or laparoscopic technique was used.Thirty-two patients underwent open right hemicolectomy, and 44 patients underwent laparoscopic right hemicolectomy. The 2 groups were similar in age, sex, American Society of Anesthesiologists class, abdominal surgical history, tumor localization, and operation time. No significant differences were found regarding the specimen length, tumor size, harvested lymph nodes, number of metastatic lymph nodes, or tumor grade. According to the Clavien–Dindo classification system, the laparoscopic group had significantly fewer complications than did the open group (11.4% vs 31.2%; P = .04). The open group had a longer postoperative hospital stay than did the laparoscopic hemicolectomy group (9.9 ± 4.7 vs 7.2 ± 3.1 days; P = .002). In addition, the groups were similar with respect to disease-free survival (P = .14) and overall survival (P = .06).The data in this study demonstrated that no differences exist between the open and laparoscopic techniques concerning pathological and oncological results. However, significantly fewer complications and a shorter length of hospital stay were observed in the laparoscopic group than in the open group. Laparoscopic right hemicolectomy with CME and central vascular ligation is a safe and feasible surgical procedure and should be considered the standard technique for right-sided colon cancer.     

Mean platelet volume in patients with polycystic ovary disease

Platelets contribute to blood coagulation at sites of vascular injury and to the recruitment of leukocytes at sites of inflammation. Under pathological conditions, platelets are involved in numerous diseases and clinical complications, such as deep venous thrombosis, embolism and atherosclerosis. But so far, little is known about the mechanisms of inflammation in large veins and the role of platelets in inflamed large veins. For this purpose, we investigated primary and secondary interactions between platelets, leukocytes and endothelial cells in the femoral vein in vivo with special regard to the role of CD62P (P-selectin) and CD162 (PSGL-1). Mice were challenged with lipopolysaccharide (LPS)/D-galactosamine (D-gal) and either CD162 or CD62P was blocked by intravenous administration of a corresponding antibody at the time point of LPS/D-gal injection. Four hours after LPS/gal injection, intravital fluorescence microscopy of the femoral vein was performed and primary and secondary platelet-leukocyte-endothelial cell-interactions were visualized after in vivo platelet and leukocyte staining with rhodamine 6G. Analysis of intravital fluorescence microscopy revealed that LPS/D-gal caused a strong inflammatory reaction of the venous endothelium with significant induction of platelet and leukocyte tethering, rolling and adhesion. Secondary interactions of platelets to adherent or rolling platelets or leukocytes were also increased after LPS/D-gal-injection. Immunoneutralization of either CD162 or CD62P significantly decreased platelet primary and secondary capture as well as leukocyte rolling and adhesion. CD162 and CD62P play a central role in mediating inflammatory primary and secondary interactions of platelets and leukocytes to the endothelium in inflamed large veins in vivo. Thus, blocking CD162 or CD62P might be an attractive tool for preventing platelet and leukocyte-driven venous diseases.     

Left ventricular systolic and diastolic function in subjects with a bicuspid aortic valve without significant valvular dysfunction

BACKGROUND:

The bicuspid aortic valve (BAV) represents the most common cardiac congenital malformation in adults. It is frequently associated with dilation, aneurysm and dissection of the ascending aorta.

OBJECTIVE:

To evaluate left ventricular systolic and diastolic function in subjects with BAVs.

METHODS:

Thirty-five subjects with BAV (mean [± SD] age 25.9±5.7 years [range 17 to 36 years]; 18 male, 17 female) with either no valvular impairment or mild valvular impairment were recruited along with 30 control subjects (24.5±4.4 years of age [range 15 to 35 years]; 15 male, 15 female) who were matched for age, sex and body surface area. Left ventricular systolic and diastolic function were evaluated using conventional and tissue Doppler echocardiography. Left ventricular systolic and diastolic parameters were compared between the two groups.

RESULTS:

In subjects with BAVs, the ratio of mitral early diastolic velocity to late diastolic velocity was lower (0.95±0.4 versus 1.27±0.9; P=0.001), the ratio of mitral early diastolic velocity to myocardial early diastolic velocity was higher (10.1±3.2 versus 6.5±2.4; P=0.001) and the myocardial early diastolic velocity was lower (8.4±2.1 versus 15.3±3.6; P<0.001) compared with control subjects. In addition, the myocardial performance index was higher in subjects with BAVs than in control subjects (P=0.03). The left ventricular ejection fraction was also lower (53±11% versus 64±13%; P<0.001). No other statistically significant differences were observed between the two groups with regard to left ventricular systolic and diastolic parameters. In addition, the number of mitral valve prolapses and atrial septal aneurysms was higher in subjects with BAVs.

CONCLUSION:

BAVs may be associated with left ventricular systolic and diastolic dysfunction.     

Clinical presentations of chlamydial and non-chlamydial reactive arthritis

The aim of this study was to investigate the triggering micro-organisms and the clinical as well as laboratory differences between Chlamydial and non-chlamydial reactive arthritis (ReA) in a prospective study on 98 patients with acute/subacute arthritis. An inciting organism was found in 42 patients. Eighteen of these were chlamydial. Fifty-seven percent of all ReA patients were carriers for HLA-B27, which increased to 67% in the chlamydial group. Chlamydial ReA patients had more urethritis (P<0.05) with a longer period between arthritis and inciting infection, significantly lower CRP levels, and involved joint counts (P<0.05). Additionally, sacroiliitis was more frequent besides extra-articular manifestations in chlamydial ReA group. This study shows that chlamydial ReA differs in some points from non-chlamydial ReA, which in turn may affect the evaluation of an arthritic patient. ReA due to chlamydia more frequently encompasses a monoarticular or oligoarticular clinical picture with predominant distal extremity involvement. Non-chlamydial ReA presents higher joint counts and may involve upper extremity joints.