The clinical effect of gender on outcome of total knee arthroplasty

The purpose of this study was to quantify the effect of sex on the clinical outcome and survivorship of a total knee arthroplasty (TKA) with clinical and radiographic follow-up. Seven thousand three hundred twenty-six primary AGC (Biomet, Warsaw, Ind) cruciate-retaining TKAs were performed from 1987 to 2004. Of these, 59.5% were performed on women. We examined preoperative and postoperative Knee Society knee score, function scores, pain scores, walking ability, stair-climbing ability, flexion, and implant survivorship based on sex. Female sex was associated with lower overall preoperative clinical scores for all parameters (P < .01). Improvement in Knee Society knee score and flexion was greater for women (P = .006), and there were equal pain relief and walking improvements for both sexes (P < .32). Stair and function score improvements were greater for men (P = .002). Implant survival was 98% for women and men at 15 years (P = .4684). We conclude that improvement after TKA is similar for men and women, with few clinically significant differences. Sex-specific implants would appear to offer no clinical advantage.     

Free vascularized fibular grafting following failed core decompression for femoral head osteonecrosis

The results of treatment of femoral head osteonecrosis with free vascularized fibular grafting (FVFG) following failed core decompression (core decompression-FVFG [CD-FVFG] group: 32 hips) were reviewed and compared with those of a control group that underwent FVFG only (54 hips). Outcome was considered unsuccessful if total hip arthroplasty was subsequently performed. Total hip arthroplasty was performed in 15 and 20 hips of the CD-FVFG and control groups, respectively. When considering age, sex, and presence of bilateral disease, patients with previous core decompression did not have a significantly different failure rate from patients with FVFG only. However, patients with preoperative stage V osteonecrosis or corticosteroid use had worse outcomes after vascularized fibular grafting if they had a previous core decompression of the femoral head.     

Effects of acute and chronic apomorphine on sex behavior and copulation-induced neural activation in the male rat

Apomorphine is a non-selective dopaminergic receptor agonist. Because of its pro-erectile effects, apomorphine is clinically used for treatment of erectile dysfunction. We investigated the effects of subcutaneous apomorphine administration (0.4 mg/kg rat) on sexual behavior and mating-induced Fos-expression following acute (day 1) or chronic apomorphine treatment (days 8 and 15) in sexually experienced male rats. Consistent facilitatory effects of apomorphine were observed in the reduced numbers of mounts and intromissions over time and an increased ejaculation frequency on day 1. The first post-ejaculatory interval, however, was lengthened, while other behavioral parameters were unaffected. Fos-immunoreactivity induced by acute apomorphine administration (barrel cortex, paraventricular hypothalamic nucleus, central amygdala and locus coeruleus) was strongly reduced after chronic administration. After mating, induction of Fos-immunoreactivity was observed in well-known areas like medial preoptic nucleus and the posterodorsal medial amygdaloid area. Apomorphine, however, reduced mating-induced Fos-immunoreactivity in the nucleus accumbens shell and prevented its occurrence in its core area. This remarkable apomorphine effect was not observed in any other brain area. We conclude that the behavioral (pro-erectile) effects of apomorphine are consistent over time, and that the diminished accumbens-Fos-immunoreactivity and the elongated post-ejaculatory interval may reflect a decreased response to remote cues from the estrus female.     

Evaluation of genome damage and its relation to oxidative stress induced by glyphosate in human lymphocytes in vitro

In the present study we evaluated the genotoxic and oxidative potential of glyphosate on human lymphocytes at concentrations likely to be encountered in residential and occupational exposure. Testing was done with and without metabolic activation (S9). Ferric‐reducing ability of plasma (FRAP), thiobarbituric acid reactive substances (TBARS) and the hOGG1 modified comet assay were used to measure glyphosate's oxidative potential and its impact on DNA. Genotoxicity was evaluated by alkaline comet and analysis of micronuclei and other nuclear instabilities applying centromere probes. The alkaline comet assay showed significantly increased tail length (20.39 μm) and intensity (2.19%) for 580 μg/ml, and increased tail intensity (1.88%) at 92.8 μg/ml, compared to control values of 18.15 μm for tail length and 1.14% for tail intensity. With S9, tail length was significantly increased for all concentrations tested: 3.5, 92.8, and 580 μg/ml. Using the hOGG1 comet assay, a significant increase in tail intensity was observed at 2.91 μg/ml with S9 and 580 μg/ml without S9. Without S9, the frequency of micronuclei, nuclear buds and nucleoplasmic bridges slightly increased at concentrations 3.5 μg/ml and higher. The presence of S9 significantly elevated the frequency of nuclear instabilities only for 580 μg/ml. FRAP values slightly increased only at 580 μg/ml regardless of metabolic activation, while TBARS values increased significantly. Since for any of the assays applied, no clear dose‐dependent effect was observed, it indicates that glyphosate in concentrations relevant to human exposure do not pose significant health risk. Environ. Mol. Mutagen. 2009. © 2009 Wiley‐Liss, Inc.     

Biomechanical testing of different osteosynthesis systems for segmental resection of the mandible.

PURPOSE: This investigation assessed the mechanical behavior of 3 different locking and nonlocking reconstruction systems-Unilock 2.4, Reconstruction 2.4, and Reconstruction 2.7-with regard to plate and screw fracture. MATERIALS AND METHODS: Five different plate/screw configurations (Unilock 2.4-locking screws, Unilock 2.4 -conventional screws, Reconstruction 2.4-conventional screws, Reconstruction 2.7-conventional screws, and Unilock 2.4-locking screws with a 1-mm gap; Synthes, Umkirch, Germany) were tested on synthetic mandibles. All mandibles were resected on the left side between the canine and third molar, reconstructed, and loaded cyclically between 30 and 300 N up to 250,000 cycles or until screw or plate failure occurred. RESULTS: No screw fractures were observed. All plates fractured close to the distal fragment. The Unilock plates fixed with locking screws withstood significantly more cycles until failure than the Reconstruction plates 2.4 fixed with conventional MF-Cortex screws. No significant differences were found in the other groups. Only 2 of the 34 plates tested, both of the Reconstruction 2.7 system, reached the runout limit. CONCLUSIONS: Unilock plates fixed with locking screws have a higher long-term stability than the Reconstruction 2.4 system. A 1-mm gap between the plate and mandible does not lead to early screw failure in the Unilock 2.4 system with locking screws. The Reconstruction 2.7 system seems superior if well contoured, because 2 of those plates reached the runout limit; however, this system is not as easy to handle as the 2.4 systems, and good contouring is difficult to achieve. Therefore, we consider the Unilock 2.4 system with locking screws the best choice.     

The Role of Myocardial KATP‐Channel Blockade in the Protective Effects of Glibenclamide against Ischaemia in the Rat Heart

Abstract: Glibenclamide preserves postischaemic myocardial function in the isolated, erythrocyte perfused, working rat heart model. This study addresses the possible involvement of K_ATP channels in this beneficial action of glibenclamide. We hypothesized that if glibenclamide improved postischaemic cardiac function by blocking of K_ATP channels, opening of these K_ATP channels should result in the opposite, namely detrimental effects on postischaemic heart function. Postischaemic functional loss and coronary blood flow were recorded during treatment with glibenclamide (4 μmol.l^?1; n=5), the K_ATP channel openers pinacidil (1 μmol.l^?1; n=5) and diazoxide (30 μmol.l^?1; n=5), the combination of glibenclamide with pinacidil (n=5) and glibenclamide with diazoxide (n=5), and vehicle (n=8). Both pinacidil and diazoxide significantly increased coronary blood flow 2–3 times, which was abolished by glibenclamide pre‐ and postischaemically. This confirms that under both flow conditions glibenclamide significantly blocks K_ATP channels in the coronary vasculature. The 12 min. global ischaemic incident resulted in a cardiac functional loss of 22.2±2.9% during vehicle. Glibenclamide reduced the cardiac functional loss to 4.3±1.2% (P<0.01). Interestingly, both pinacidil and diazoxide reduced the cardiac functional loss to 4.0±1.5% (P<0.01) and 2.9±1.4% (P<0.001), respectively. The combination pinacidil+glibenclamide resulted in additional protection compared with the individual components (0.6±0.1 versus 4.0±1.5%, P<0.05). Thus, in contrast to its effect on coronary vascular tone, the glibenclamide‐induced improvement of postischaemic cardiac function may not be mediated through blockade of the K_ATP channel. Alternative mechanisms may be operative, such as uncoupling of the mitochondrial respiratory chain, thereby preconditioning the hearts against stunning.     

Pullout strength of anterior spinal instrumentation: a product comparison of seven screws in calf vertebral bodies

A lot of new implant devices for spine surgery are coming onto the market, in which vertebral screws play a fundamental role. The new screws developed for surgery of spine deformities have to be compared to established systems. A biomechanical in vitro study was designed to assess the bone–screw interface fixation strength of seven different screws used for correction of scoliosis in spine surgery. The objectives of the current study were twofold: (1) to evaluate the initial strength at the bone–screw interface of newly developed vertebral screws (Universal Spine System II) compared to established systems (product comparison) and (2) to evaluate the influence of screw design, screw diameter, screw length and bone mineral density on pullout strength. Fifty-six calf vertebral bodies were instrumented with seven different screws (USS II anterior 8.0 mm, USS II posterior 6.2 mm, KASS 6.25 mm, USS II anterior 6.2 mm, USS II posterior 5.2 mm, USS 6.0 mm, USS 5.0 mm). Bone mineral density (BMD) was determined by quantitative computed tomography (QCT). Failure in axial pullout was tested using a displacement-controlled universal test machine. USS II anterior 8.0 mm showed higher pullout strength than all other screws. The difference constituted a tendency (P = 0.108) when compared to USS II posterior 6.2 mm (+19%) and was significant in comparison to the other screws (+30 to +55%, P < 0.002). USS II posterior 6.2 mm showed significantly higher pullout strength than USS 5.0 mm (+30%, P = 0.014). The other screws did not differ significantly in pullout strength. Pullout strength correlated significantly with BMD (P = 0.0015) and vertebral body width/screw length (P < 0.001). The newly developed screws for spine surgery (USS II) show higher pullout strength when compared to established systems. Screw design had no significant influence on pullout force in vertebral body screws, but outer diameter of the screw, screw length and BMD are good predictors of pullout resistance.     

Laser-assisted removal of a foreign body from the colon

Summary An 81-year-old woman underwent a colonoscopy because of a sigmoiditis poorly responding to conservative therapy. A rod-shaped foreign body found in the sigma proved impossible to remove conventionally. Irradiation with a low laser energy caused the foreign body to break apart, after which its extraction was straightforward. The further clinical course was uncomplicated. In this case a partial sigmoidectomy would have been indicated had the laser-supported extraction not been successful. The authors suggest that a similar procedure could be helpful in the management of foreign bodies in the esophagus.