The State of Starch/Hydroxyapatite Composite Scaffold in Bone Tissue Engineering with Consideration for Dielectric Measurement as an Alternative Characterization Technique

Hydroxyapatite (HA) has been widely used as a scaffold in tissue engineering. HA possesses high mechanical stress and exhibits particularly excellent biocompatibility owing to its similarity to natural bone. Nonetheless, this ceramic scaffold has limited applications due to its apparent brittleness. Therefore, this had presented some difficulties when shaping implants out of HA and for sustaining a high mechanical load. Fortunately, these drawbacks can be improved by combining HA with other biomaterials. Starch was heavily considered for biomedical device applications in favor of its low cost, wide availability, and biocompatibility properties that complement HA. This review provides an insight into starch/HA composites used in the fabrication of bone tissue scaffolds and numerous factors that influence the scaffold properties. Moreover, an alternative characterization of scaffolds via dielectric and free space measurement as a potential contactless and nondestructive measurement method is also highlighted.     

Value of prolonged QRS duration as a predictor of low cardiac output syndrome in patients with impaired left ventricular systolic function who undergo isolated coronary artery bypass grafting

This study determined whether prolonged QRS duration (QRSd; > or =120 ms) is an independent predictor of low cardiac output syndrome (LCOS) in patients with low left ventricular (LV) ejection fraction (EF) who underwent isolated coronary artery bypass grafting (CABG). Abnormal LV systolic function places patients at greater risk for developing LCOS after isolated CABG. In patients with this form of ventricular function impairment, prolonged QRSd is associated with adverse hemodynamic effects. Clinical, operative, and outcome data from 190 consecutive patients with LVEF <50% who underwent isolated CABG (mean 62 +/- 9 years of age) were retrospectively analyzed. For all patients, preoperative QRSd was determined. LCOS was the primary outcome investigated. Fifty-seven patients (30%) developed LCOS. Compared with the subgroup without LCOS, the subgroup with this syndrome had significantly larger proportions of patients with LVEF <30% and prolonged QRSd. In addition, the group that developed LCOS had a longer mean QRSd (117 +/- 25 vs 102 +/- 17 ms, respectively, p = 0.00003) and a significantly higher frequency of adverse postoperative outcomes. Hospital stay was significantly longer in the subgroup with LCOS than in the subgroup without. Multivariate logistic regression analysis identified prolonged QRSd as the most significant predictor of LCOS. LVEF <30%, diuretic therapy, and preoperative risk score (European System for Cardiac Operative Risk Evaluation) were also identified as independent predictors of LCOS. In conclusion, in patients with impaired LV systolic function, prolonged QRSd is a highly significant predictor of LCOS development after isolated CABG.     

Epicardial Adipose Tissue Increased in Patients with Newly Diagnosed Subclinical Hypothyroidism

Objective

To investigate whether or not patients with subclinical hypothyroidism (SH) have increased epicardial adipose tissue (EAT).

Subjects and Methods

Sixty-one patients with newly diagnosed SH and without any known cardiovascular disease were enrolled. Twenty-four subjects matched for age, gender and body mass index without any thyroid dysfunctions were included as a control group. The EAT was measured by echocardiography and thyroid functions were assessed by routine blood examination.

Results

Patients with SH had higher EAT values than control subjects (3.6 ± 0.9 vs. 2.8 ± 1.4, p = 0.005). Also, SH patients with thyroid-stimulating hormone (TSH) ≥10 mU/l had higher EAT than those with SH with TSH <10 mU/l and control subjects (p = 0.013). In addition, while there was significant correlation between EAT and TSH (r = 0.31, p = 0.014) in patients with SH, there was no significant relation between EAT and TSH in normal subjects (r = 0.09, p = 0.64).

Conclusions

There was a higher level of EAT in patients with SH compared with normal subjects and a significant correlation between EAT and TSH was found.Key Words: Epicardial fat, Coronary heart disease, Subclinical hypothyroidism     

Brucella glomerulonephritis: review of the literature and report on the first patient with brucellosis and mesangiocapillary glomerulonephritis

Although mild proteinuria is commonly observed during the course of brucellosis, biopsy-proven glomerulonephritis (GN) is quite rare. We present the first case of mesangiocapillary glomerulonephritis (MCGN) associated with brucellosis and summarize all cases of Brucella GN published to date. Our patient, who had a congenital bicuspid aortic valve, also had heart failure, fever, urinary abnormalities and proteinuria. Renal biopsy revealed MCGN. Although the clinical features raised the possibility of GN associated with endocarditis, transesophageal echocardiography did not show any vegetations.     

Forces acting on the anterior meniscotibial ligaments

Purpose

The purpose of this study was to investigate the forces occurring in human anterior meniscotibial attachment structures under various loading conditions.

Methods

Twelve human knee joints were exposed to eight loading conditions (tibial rotations and varus/valgus stress) using a previously described knee joint simulator. Subsequently, the joints were axially compressed (1,000?N at 0° 30° and 60° knee flexion) using a materials testing machine. Then, we performed a tensile test to failure of the ligaments. Finally, we used the strains that occurred during the loading tests and the force–elongation diagrams obtained from the tensile test to recursively assess the resulting forces.

Results

In the anterior meniscotibial ligaments, we found maximum mean strains of 3.8?±?2.3% under external moments and 1.5?±?0.9% for axial compression. With an ultimate load of 454?±?220?N for the anterolateral meniscotibial ligament and 397?±?275?N for the anteromedial meniscotibial ligament, we estimated maximum forces of up to 50.2?N for the knee simulator tests and 22.6?N for the axial compression tests.

Conclusions

The low forces found in the meniscal ligaments suggest that for normal daily activities, meniscal replacement implants and allografts do not require a very rigid fixation at their bony insertions. However, it remains unknown, what level of force occurs in the meniscotibial ligaments under traumatic situations or impact knee loads. Furthermore, the results of the present study could help to optimize meniscal re-fixation and to improve the properties of meniscal replacement materials, such as tissue-engineered artificial menisci. Moreover, the results could be used for the validation of finite element models of the knee joint with the main focus on the meniscus and its biomechanical relevance for tibiofemoral contact pressure.     

Combination thymosin-alpha 1 and interferon-alpha 2b in the treatment of anti-HBe-positive chronic hepatitis B in Turkey

BACKGROUND/AIMS: The most prevalent type of chronic hepatitis B in Turkey is anti-HBe-positive. No consistently effective therapy is yet available for the treatment of these patients. The aim of this study was to assess the efficacy and safety of interferon-alpha and thymosin-alpha 1 combination in the treatment of naive anti-HBe-positive and HBV DNA-positive chronic hepatitis B patients. METHODOLOGY: Twenty-one patients were enrolled in the study. All patients had documented anti-HBe-positive, HBV DNA-positive chronic active hepatitis B without evidence of cirrhosis. Patients received a 26-week combination course of 1.6 mg thymosin-alpha 1 subcutaneously twice a week and 10 MIU interferon-alpha subcutaneously three times a week, followed by interferon-alpha monotherapy at the same dose for another 26 weeks. After treatment patients were observed for a further 26 weeks. Endpoints were a normalization of alanine aminotransferase and negativity of HBV DNA at weeks 52 and 78, as well as an improvement in liver histology at week 78. RESULTS: Eighteen (87.7%) of the 21 patients responded by losing serum HBV DNA and normalizing alanine aminotransferase values at the end of the 52-week treatment period. Sixteen (76.2%) of these patients became sustained responders, with normal alanine aminotransferase and negative HBV DNA at the end of 78 weeks. Two patients were non-responders, two relapsed and one had a breakthrough during therapy. Significant improvements in the Knodell histological activity index were observed in the responders. No adverse events other than those seen previously with interferon monotherapy were reported. CONCLUSIONS: Combination interferon-alpha 2b and thymosin-alpha 1 treatment may provide a safe and effective therapeutic approach for the difficult-to-treat anti-HBe-positive chronic hepatitis B patients. Further controlled studies are needed to assess the full role of this treatment strategy.     

Surgical treatment of infective valve endocarditis in children with congenital heart disease

Abstract Objective: This study assesses surgical procedures, operative outcome, and early and intermediate‐term results of infective valve endocarditis in children with congenital heart disease. Methods: Seven consecutive children (five females, two males; mean age, 10.8 years) who underwent surgery for infective valve endocarditis between 2006 and 2010 were included in the study. The aortic and mitral valves were affected in two and tricuspid in five patients. Indications for operation included cardiac failure due to atrioventricular septal rupture, severe tricuspid valve insufficiency, and septic embolization in one, moderate valvular dysfunction with vegetations in three (two tricuspid, one mitral), and severe valvular dysfunction with vegetations in the other three patients (two tricuspid, one mitral). The pathological microorganism was identified in five patients. Tricuspid valve repair was performed with ventricular septal defect (VSD) closure in five patients. Two patients required mitral valve repair including one with additional aortic valve replacement. Results: There were no operative deaths. Actuarial freedom from recurrent infection at one and three years was 100%. Early echocardiographic follow‐up showed four patients to have mild atrioventricular valve regurgitation (three tricuspid and one mitral) and three had no valvular regurgitation. No leakage from the VSD closure or any valvular stenosis was detected postoperatively. Conclusions: Mitral and tricuspid valve repairs can be performed with low morbidity/mortality rates and satisfactory intermediate‐term results in children with infective valve endocarditis . (J Card Surg 2012;27:93‐98)     

Reversible posterior leukoencephalopathy in the course of Goodpasture syndrome

Reversible posterior leukoencephalopathy syndrome (RPLS) is characterized by headache, altered consciousness, seizures, and cortical blindness. The most frequent etiological factors are hypertension, kidney diseases, and immunosuppressive drugs such as steroids and cyclophosphamide. Herein we present a case of a 22-year-old female patient presented with alveolar hemorrhage and acute renal failure necessitating hemodialysis. In renal biopsy, necrotizing crescentic glomerulonephritis and immunofluorescence pattern compatible with Goodpasture syndrome were found. Anti-glomerular basement membrane antibody result was positive. At follow-up, respiratory failure ensued, steroid pulse treatment was started, and she was transferred to intensive care unit (ICU). In the ICU, she had visual disturbances and blindness together with seizures. Cranial magnetic resonance imaging (MRI) revealed irregular T2- and fluid-attenuated inversion recovery (FLAIR)-weighted lesions in bilateral occipital lobes. On clinical and radiological grounds, RPLS was diagnosed. With the supportive and anti-hypertensive treatment, RPLS was resolved without a sequela. Subsequent cranial MRI was totally normal. In the literature, RPLS associated with Goodpasture syndrome was reported only once. Hypertension and methylprednisolone might be the responsible etiologies in this case.