Shear-wave elastography in the diagnosis of ulnar tunnel syndrome.

An interesting alternative to traditional diagnostic techniques of the upper extremity nerve entrapments might be an ultrasound elastography that has started to gain attention in recent research. The aim of this preliminary study was to verify whether a quantitative analysis of the ulnar nerve stiffness by shear-wave elastography can be used to diagnose ulnar tunnel syndrome (UTS), an ulnar nerve neuropathy at Guyon's canal. The study included 46 patients (39 women) and 39 healthy controls (34 women). All diagnoses in patients and controls were confirmed with nerve conduction studies. Measurements of nerve stiffness were taken at three levels: Guyon's canal (G), distal forearm (DF), and mid forearm (MF). Additionally, the ulnar nerve cross-sectional area at the canal's level was determined by ultrasonography. Patients with UTS presented with significantly greater nerve stiffness than the controls (mean, 99.41 kPa vs. 49.08 kPa, P < 0.001). No significant intergroup differences were found in the nerve elasticity at DF and MF levels (P < 0.836 and P < 0.881, respectively). An ulnar nerve stiffness value of 80 kPa and G:DF and G:MF ratios equal to 1.5 provided 100% sensitivity, specificity, and positive and negative predictive values in the detection of the syndrome. The mean nerve cross-sectional area in the Guyon's canal was significantly greater in patients than in the controls (4.63 mm2, range, 2-7 mm2 vs. 3.23 mm2, range, 2-5 mm2, P < 0.001). In conclusion, we believe that shear-wave elastography has the potential to become a useful adjunct diagnostic test for UTS.

Determining the genetic stability of micropropagated sugarcane using inter-simple sequence repeat markers.

Sugarcane culture is an important source of income for the Brazilian economy. The aim of this study was to identify somaclonal variation in sugarcane varieties RB943365 and RB92579 arising from micropropagation using inter-simple sequence repeat (ISSR) DNA markers. The evaluated plants were generated from the in vitro propagation of shoot tips grown in MS medium supplemented with vitamins, myoinositol, glycine, and sucrose, without the use of growth regulators. Fifteen consecutive subcultures with intervals of 14 days were carried out, and DNA was extracted from young leaves obtained from each of the subcultures. The DNA was amplified with ISSR markers and separated by electrophoresis on 2% agarose gels. No evidence of polymorphism was observed in subcultures of the varieties analyzed, suggesting the absence of somaclonal variants. In this way, the ISSR marker was efficient at analyzing somaclonal variation, and in vitro propagation of sugarcane can be considered efficient for 15 consecutive subcultures of the varieties analyzed.

Genetic variability and resistance of cultivars of cowpea [Vigna unguiculata (L.) Walp] to cowpea weevil (Callosobruchus maculatus Fabr.).

The cowpea weevil (Callosobruchus maculatus Fabr.) is the most destructive pest of the cowpea bean; it reduces seed quality. To control this pest, resistance testing combined with genetic analysis using molecular markers has been widely applied in research. Among the markers that show reliable results, the inter-simple sequence repeats (ISSRs) (microsatellites) are noteworthy. This study was performed to evaluate the resistance of 27 cultivars of cowpea bean to cowpea weevil. We tested the resistance related to the genetic variability of these cultivars using ISSR markers. To analyze the resistance of cultivars to weevil, a completely randomized test design with 4 replicates and 27 treatments was adopted. Five pairs of the insect were placed in 30 grains per replicate. Analysis of variance showed that the number of eggs and emerged insects were significantly different in the treatments, and the means were compared by statistical tests. The analysis of the large genetic variability in all cultivars resulted in the formation of different groups. The test of resistance showed that the cultivar Inhuma was the most sensitive to both number of eggs and number of emerged adults, while the TE96-290-12-G and MNC99-537-F4 (BRS Tumucumaque) cultivars were the least sensitive to the number of eggs and the number of emerged insects, respectively.