Novel Tenascin-C Haplotype Modifies the Risk for a Failure to Heal After Rotator Cuff Repair.

BACKGROUND: Several single-nucleotide polymorphisms (SNPs) in the TNC gene have recently been found to be associated with degenerative rotator cuff tears. HYPOTHESIS: Exonic SNPs in the TNC gene are related to the risk for a failure to heal after rotator cuff repair. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A total of 302 patients from the Vienna area and European Caucasian ancestry underwent mini-open rotator cuff repair for a full-thickness superior or posterosuperior tear and were assessed for the integrity of the repair 1 year postoperatively with a real-time 7.5- to 10-MHz ultrasound linear array transducer. Outcomes were classified as intact (complete footprint coverage), small (<200 mm2), or large (≥200 mm2) recurrent defect. Patients were genotyped for 15 previously identified risk SNPs within a 49-kbp segment of the TNC gene with the KASP genotyping technology or the Ion-Torrent Personal Genome Machine System. RESULTS: All recurrent defects were atraumatic failures, and the overall failure rate was 39.7%. Of the traditional risk factors, only the initial tear size was significantly associated with a failure to heal. In a multinomial logistic regression model, the T allele at rs1138545 [C>T] was protective for a large recurrent defect (odds ratio = 0.16; 95% CI, 0.09-0.31). The role of rs1138545 was further backed by haplotype analysis, which showed that the combination of the C allele at rs1138545 [C>T], the A allele at rs2104772 [A>T], and the G allele at rs10759752 [A>G] formed the risk-related haplotype [CAG]. The CAG haplotype was associated with large recurrent defects ( P < .0001; haplotype frequency, 0.394; haplotype score, 4.518). Exonic marker rs1138545 transcribed into all isoforms of the TNC protein, whereas exonic marker rs2104772, which has been associated with Achilles tendinopathy before, transcribed only into large isoforms of the TNC protein. CONCLUSION: Recurrent defects after rotator cuff repairs are clinically relevant, and a heritable component of the disorder is plausible on the basis of a genetic association with 8 TNC variants. Characterization of TNC sequences that favor tendon healing will help engineer new products in regenerative medicine.

Extra fructose in the growth medium fuels lipogenesis of adipocytes.

Fructose in excessive amounts exerts negative effects on insulin sensitivity, blood pressure, and liver metabolism. These adverse outcomes were attributed to its disturbances of key metabolic pathways in the liver. Recently, possible consequences of high fructose levels directly on adipocytes in vivo have been considered. We have cultured adipocytes in growth media containing 1 g/L fructose additionally to glucose and monitored the cells fate. Cells developed lipid vesicles much earlier with fructose and showed altered kinetics of the expression of mRNAs involved in lipogenesis and hexose uptake. Adiponectin secretion, too, peaked earlier in fructose containing media than in media with glucose only. From these data it can be speculated that similar effects of fructose containing diets happen in vivo also. Apart from toxic action on liver cells, adipocytes might be stimulated to take up extra fructose and generate new lipid vesicles, further dysregulating energy homeostasis.

Circulating retinol-binding protein 4 and metabolic syndrome in the elderly.

BACKGROUND: Retinol-binding protein (RBP) 4, a human adipokine that specifically binds to retinol, has been reported to provide a link between obesity and insulin resistance. Plasma RBP4 concentration may be under the influence of age and obesity, but only a few studies has investigated this link in elderly individuals. Consequently, we tested the correlation between RBP4 concentrations and type 2 diabetes/metabolic syndrome (MetS) components in a large population based cohort study (VITA) of elderly [1, 2]. Using a single birth cohort, this investigation could exclude the influence of age. METHODS: We evaluated the correlation of RBP4 with type 2 diabetes and MetS components including Body Mass Index (BMI), blood pressure, lipid parameters, fasting glucose insulin, homeostasis model assessment insulin resistance (HOMA-IR), and smoking in exclusively 75-76 year old participants (N = 232). RESULTS: In the present study, RBP4 concentrations were associated with type 2 diabetes and metabolic syndrome (MetS) components. Of all the individual components of metabolic syndrome that were associated with RBP4 concentrations, the correlations of RBP4 with serum triglycerides and a negative correlation with HDL were the strongest ones observed in our study cohort (p<0.0001). CONCLUSIONS: RBP4 plays a role in biological mechanisms that are responsible for insulin resistance and development of type 2 diabetes.

Diagnosis of infection with human herpes viruses in routine laboratory practice.

BACKGROUND: The potential for faster detection of human herpes viruses using PCR compared to other methods is undisputed. However, because of fear of contamination, the clinical implication of nucleic amplification methods in routine laboratories is not widespread. Herpes viruses cause a wide spectrum of diseases and can cause morbidity and mortality in immune-compromised patients. Using real-time PCR, most of the problems associated with PCR (contamination, cumbersome detection, and rather expensive tests) are solved, and a rapid, economical, and--most importantly--closed system is at hand. METHODS: We evaluated work procedures in our laboratory that enable the routine diagnosis of viral infections with high accuracy and rapid turn-around time. In parallel, inherent problems usually associated with PCR testing, especially cross-contamination could be suppressed to a minimum. The start of the work flow process begins with an automated nucleic acid extraction procedure that yields high quality DNA. A common--internally and externally controlled--PCR program for all six viruses allows rapid sample turn around. RESULTS: In all, 7500 analyses for human herpes virus infection were performed in the last 5 years. Results for various different specimens were produced within 24 h. Contamination occurred rarely and could be ameliorated easily. The use of internal controls identified rare PCR-inhibited samples. The detection limits for our assays are markedly below the clinically relevant range. CONCLUSIONS: Our workflow allowed rapid, cost-efficient, and labor saving routine diagnostic detection of viral infections.