Cross education of muscular strength during unilateral resistance training and detraining

Abstract. The purpose of the present study was to examine the changes in maximum voluntary isometric contraction (MVC) in the contralateral untrained limb during unilateral resistance training and detraining, and to examine the factors inducing these changes by means of electrophysiological techniques. Nine healthy males trained their plantar flexor muscles unilaterally 4 days·week^–1 for 6 weeks using 3 sets of 10–12 repetitions at 70–75% of one-repetition maximum a day, and detrained for 6 weeks. Progressive unilateral resistance training significantly (P<0.05) increased MVC, integrated electromyogram (iEMG), and voluntary activation in the trained and contralateral untrained limbs. The changes in MVC after training were significantly correlated with the changes in iEMG in both limbs. No significant changes occurred in MVC, voluntary activation, and iEMG in the contralateral limb after detraining. The changes in MVC after detraining did not correlate with the changes in voluntary activation or iEMG in either limb. Training and detraining did not alter twitch and tetanic peak torques in either limb. These results suggest that the mechanisms underlying cross education of muscular strength may be explained by central neural factors during training, but not solely so during detraining. Electronic Publication     

Plectin deficiency leads to both muscular dystrophy and pyloric atresia in epidermolysis bullosa simplex

Plectin is a cytoskeletal linker protein which has a long central rod and N‐ and C‐terminal globular domains. Mutations in the gene encoding plectin (PLEC) cause two distinct autosomal recessive subtypes of epidermolysis bullosa: EB simplex (EBS) with muscular dystrophy (EBS‐MD), and EBS with pyloric atresia (EBS‐PA). Previous studies have demonstrated that loss of full‐length plectin with residual expression of the rodless isoform leads to EBS‐MD, whereas complete loss or marked attenuation of expression of full‐length and rodless plectin underlies the more severe EBS‐PA phenotype. However, muscular dystrophy has never been identified in EBS‐PA, not even in the severe form of the disease. Here, we report the first case of EBS associated with both pyloric atresia and muscular dystrophy. Both of the premature termination codon‐causing mutations of the proband are located within exon 32, the last exon of PLEC. Immunofluorescence and immunoblot analysis of skin samples and cultured fibroblasts from the proband revealed truncated plectin protein expression in low amounts. This study demonstrates that plectin deficiency can indeed lead to both muscular dystrophy and pyloric atresia in an individual EBS patient. © 2010 Wiley‐Liss, Inc.     

Unusual trihydroxy bile acids in the urine of patients treated with chenodeoxycholate, ursodeoxycholate or rifampicin and those with cirrhosis

Urinary bile acids from 20 patients treated with chenodeoxycholate, 18 treated with ursodeoxycholate, 15 treated with rifampicin and 8 patients with advanced cirrhosis were analyzed by gas-liquid chromatography and gas-liquid chromatography-mass spectrometry. Occurrence rates and amounts of three so-called unusual trihydroxy bile acids, hyocholate, ursocholate and omega-muricholate, were increased in patients treated with chenodeoxycholate, ursodeoxycholate or rifampicin and decreased in cirrhotic patients as compared with those in untreated healthy adults. These data suggest that chenodeoxycholate and ursodeoxycholate are hydroxylated to produce unusual trihydroxy bile acids in bile acid-loaded humans and that this metabolism may be related to the induction of hepatic microsomal enzymes by rifampicin. In contrast, the hydroxylation of chenodeoxycholate and ursodeoxycholate may be impaired by severe hepatic damage. Because the urine is a secretory pathway for internal bile acids, the occurrence of unusual trihydroxy bile acids in the urine may be used as an indicator of hepatic ability to metabolize "hydrophobic" dihydroxy bile acids to their secretory forms.     

Effects of a calcium-antagonist on vascular sympathetic nerve activity in salt-dependent hypertension

The purpose of the present study was to investigate the effects of a Ca2(+)-antagonist on vascular sympathetic nerve activity in salt-dependent hypertension. Isolated mesenteric vasculature preparations from reduced renal mass-salt hypertensive and age-matched normotensive control rats were used to examine the effects of diltiazem on vascular responsiveness and norepinephrine release from sympathetic nerve endings. Pressor responses and endogenous norepinephrine release during electrical nerve stimulation were significantly greater in preparations from salt-dependent hypertensive rats than from normotensive control rats. Diltiazem inhibited both stimulation-evoked pressor responses and norepinephrine release in a dose-dependent manner. The attenuation of these responses was more pronounced in preparations from rats with salt-dependent hypertension than in those from control rats. These results indicate that norepinephrine release from vascular adrenergic neurons is enhanced in the mesenteric vasculatures of rats with salt-dependent hypertension. The marked reduction of stimulation-evoked pressor responses and norepinephrine release by diltiazem suggests that enhanced Ca2(+)-dependent adrenergic transmission may contribute to the exaggerated vascular sympathetic tone in salt-dependent hypertension.     

Two-dimensional motion analysis of dynamic knee valgus identifies female high school athletes at risk of non-contact anterior cruciate ligament injury

Purpose

Female athletes are at greater risk of non-contact ACL injury. Three-dimensional kinematic analyses have shown that at-risk female athletes have a greater knee valgus angle during drop jumping. The purpose of this study was to evaluate the relationship between knee valgus angle and non-contact ACL injury in young female athletes using coronal-plane two-dimensional (2D) kinematic analyses of single-leg landing.

Methods

Two hundred ninety-one female high school athletes newly enrolled in basketball and handball clubs were assessed. Dynamic knee valgus was analysed during single-leg drop jumps using 2D coronal images at hallux–ground contact and at maximal knee valgus. All subjects were followed up for 3 years for ACL injury. Twenty-eight (9.6%) of 291 athletes had ACL rupture, including 27 non-contact ACL injuries. The injured group of 27 knees with non-contact ACL injury was compared with a control group of 27 randomly selected uninjured knees. The relationship between initial 2D movement analysis results and subsequent ACL injury was investigated.

Results

Dynamic knee valgus was significantly greater in the injured group compared to the control group at hallux–ground contact (2.1 ± 2.4 vs. 0.4 ± 2.2 cm, P = 0.006) and at maximal knee valgus (8.3 ± 4.3 vs. 5.1 ± 4.1 cm, P = 0.007).

Conclusion

The results of this study confirm that dynamic knee valgus is a potential risk factor for non-contact ACL injury in female high school athletes. Fully understanding the risk factors that increase dynamic knee valgus will help in designing more appropriate training and interventional strategies to prevent injuries in at-risk athletes.

Level of evidence

Prognostic studies, Level II.

     

Clinical application of scaffolds for cartilage tissue engineering

The purpose of this paper is to review the basic science and clinical literature on scaffolds clinically available for the treatment of articular cartilage injuries. The use of tissue-engineered grafts based on scaffolds seems to be as effective as conventional ACI clinically. However, there is limited evidence that scaffold techniques result in homogeneous distribution of cells. Similarly, few studies exist on the maintenance of the chondrocyte phenotype in scaffolds. Both of which would be potential advantages over the first generation ACI. The mean clinical score in all of the clinical literature on scaffold techniques significantly improved compared with preoperative values. More than 80% of patients had an excellent or good outcome. None of the short- or mid-term clinical and histological results of these tissue-engineering techniques with scaffolds were reported to be better than conventional ACI. However, some studies suggest that these methods may reduce surgical time, morbidity, and risks of periosteal hypertrophy and post-operative adhesions. Based on the available literature, we were not able to rank the scaffolds available for clinical use. Firm recommendations on which cartilage repair procedure is to be preferred is currently not known on the basis of these studies. Randomized clinical trials and longer follow-up periods are needed for more widespread information regarding the clinical effectiveness of scaffold-based, tissue-engineered cartilage repair.     

Effect of propofol on sevoflurane agitation in children

BACKGROUND: Sevoflurane may be associated with a high incidence of agitation during recovery from anesthesia in children. We tested the hypothesis that bolus administration of propofol after sevoflurane anesthesia would reduce the incidence of recovery agitation compared with sevoflurane anesthesia alone. METHODS: We conducted a randomized, double-blinded study in 90 children, 1-7 yr of age, undergoing short general anesthesia. They were divided into three groups; 2 mg.kg-1 propofol (group P2), 1 mg.kg-1 propofol (group P1) and intralipid 0.2 ml.kg-1 as control (group C). After sevoflurane induction and maintenance and 5 minutes before the end of operation, propofol or intralipid was administered. We compared the speed and quality of each recovery. We made a new scoring system for the assessment of agitation. Each child received a point from -4 to 10 with this system. RESULTS: Recovery score was similar among the three groups (group P2 had point 4, group P1, point 5, and group C point 4). Recovery time in group P2 was significantly longer than that in group C (about 6 minutes). CONCLUSIONS: Bolus administration of propofol after sevoflurane anesthesia prolonged recovery time, but did not inhibit sevoflurane agitation compared with sevoflurane anesthesia alone.     

Trials of vaccines for pancreatic ductal adenocarcinoma: Is there any hope of an improved prognosis?

Pancreatic tumors are chemoresistant and malignant, and there are very few therapeutic options for pancreatic cancer, as the disease is normally diagnosed at an advanced stage. Although attempts have been made to develop vaccine therapies for pancreatic cancer for a couple of decades, none of the resultant protocols or regimens have succeeded in improving the clinical outcomes of patients. We herein review vaccines tested within the past few years, including peptide, biological and multiple vaccines, and describe the three sets of criteria used to evaluate the therapeutic activity of vaccines in solid tumors.     

Is a surgical approach justified for octogenarians with pancreatic carcinoma? Projecting surgical decision making for octogenarian patients

Background

In recent years, more elderly patients have undergone surgery for pancreatic cancer, although the safety and efficacy of performing complex pancreatic resections in patients older than 80 years remain controversial.

Methods

Patients with pancreatic cancer who underwent curative surgical treatment were divided into 2 subgroups: the younger group (<80 years) and the octogenarian group (≥80 years).

Results

From March 2005 to December 2013, 194 consecutive surgically curable patients with diagnosed pancreatic cancer were studied, among which 34 (17.5%) were of 80 years or older. There were no significant differences in postoperative severe complication rates for younger and octogenarian groups (16% vs 20%, respectively) or perioperative mortality rates (1.3% vs .0%). The incidence of postoperative delirium in the octogenarian group was greater than that in the younger group (23.5% vs 3.8%).

Conclusions

Octogenarian pancreatic cancer patients should not be denied a priori the opportunity for surgery, particularly if the patient represents an ideal candidate and if the co-operation of the family can be obtained.