The sheep as a knee osteoarthritis model: early cartilage changes after meniscus injury and repair

The purpose of this study was to analyse cartilage changes after traumatic meniscal lesions and to provide a detailed description of the model used with a view to reducing the number of animals used in future studies. The sheep's knee was chosen, as ovine biomechanics are similar to that of humans. In two groups of 10 animals each, a radial tear in the medial meniscus was either sutured with polydioxanone (PDS) or left untreated (sham-operated). Half of the animals in each group were sacrificed after six months, the other half after one year. The time periods to achieve weight bearing, meniscus healing, joint effusion (magnetic resonance imaging scan) and knee cartilage in the medial, lateral and patellofemoral compartments were evaluated in comparison to the opposite knee (control). Osteoarthritis (OA) was assessed by a modified Outerbridge classification and confirmed by scanning electron microscopy. Only one sutured meniscus remained completely adapted. In all other meniscus lesions, the rupture healed with a scar. In the PDS and sham-operated groups, OA was significantly higher in the medial knee compartment than in the lateral compartment and in controls (P < 0.001). In the operated groups, joint effusion was higher in the right hindlimb knee than in the normal left hindlimb knee (control) after six and 12 months (P < 0.001). Non-treated, displaced and even adapted sutured radial ovine meniscus tears produced intense OA within less than six months. Therefore, this animal model is suitable for assessment of new therapeutic regimens in meniscal surgery.

pH nanoenvironment at the surface of single melanoma cells

Extracellular pH and the Na(+)/H(+) exchanger (NHE1) modulate tumor cell migration. Yet, the pH nanoenvironment at the outer surface of the cell membrane (pH(em)) where cell/matrix interaction occurs and matrix metalloproteinases work was never measured. We present a method to measure this pH nanoenvironment using proton-sensitive dyes to label the outer leaflet of the plasma membrane or the glycocalyx of human melanoma cells. Polarized cells generate an extracellular proton gradient at their surface that increases from the rear end to the leading edge of the lamellipodium along the direction of movement. This gradient collapses upon NHE1 inhibition by HOE642. NHE1 stimulation by intracellular acidification increases the difference in pH(em) between the tips of lamellipodia and the cell body in a Na(+) dependent way. Thus, cells create a pH nanoenvironment that promotes cell migration by facilitating cell adhesion at their front and the release of cell/matrix contacts at their rear part.

Increased brain oxygenation during intubation-related stress

BACKGROUND AND OBJECTIVES

The purpose of this study was to determine whether brain oxyhaemoglobin-deoxyhaemoglobin coupling was altered by anaesthesia or intubation-induced stress.

METHODS

This was a prospective observational study in the operating room. Thirteen patients (ASA I and II) undergoing spinal or peripheral nerve procedures were recruited. They were stabilized before surgery with mask ventilation of 100% oxygen. Anaesthesia was induced with 2 microg kg(-1) fentanyl and 3 mg kg(-1) thiopental. Laryngoscopy and intubation were performed 4 min later. After intubation, desflurane anaesthesia (FiO2=1.0) was adjusted to maintain response entropy of the electroencephalogram at 40-45 for 20 min. Prefrontal cortex oxyhaemoglobin and deoxyhaemoglobin were determined every 2 s using frequency domain near-infrared spectroscopy. Blood pressure, heart rate and response entropy were collected every 10 s.

RESULTS

Awake oxyhaemoglobin and deoxyhaemoglobin were 18.9 +/- 2.3 micromol (mean +/- SD) and 12.7 +/- 0.8 micromol, respectively, and neither changed significantly during induction. Intubation increased oxyhaemoglobin by 37% (P < 0.05) and decreased deoxyhaemoglobin by 16% (P < 0.05), and both measures returned to baseline within 20 min of desflurane anaesthesia. Blood pressure, heart rate and electroencephalogram response entropy increased during intubation, and the increase in heart rate correlated with the increase in brain oxygen saturation (r = 0.48, P < 0.05).

CONCLUSIONS

Intubation-related stress increased oxyhaemoglobin related to electroencephalogram and autonomic activation. Stress-induced brain stimulation may be monitored during anaesthesia using frequency domain near-infrared spectroscopy.

Rapid freeze-substitution preserves membranes in high-pressure frozen tissue culture cells

We describe a method for high-pressure freezing and rapid freeze-substitution of cells in tissue culture which provides excellent preservation of membrane detail with negligible ice segregation artefacts. Cells grown on sapphire discs were placed 'face to face' without removal of tissue culture medium and frozen without the protection of aluminium planchettes. This reduction in thermal load of the sample/holder combination resulted in freezing of cells without visible ice-crystal artefact. Freeze-substitution at -90 degrees C for 60 min in acetone containing 2% uranyl acetate, followed by warming to -50 degrees C and embedding in Lowicryl HM20 gave consistent and clear membrane detail even when imaged without section contrasting. Preliminary data indicates that the high intrinsic contrast of samples prepared in this way will be valuable for tomographic studies. Immunolabelling sensitivity of sections of samples prepared by this rapid substitution technique was poor; however, reducing the uranyl acetate concentration in the substitution medium to 0.2% resulted in improved labelling. Samples substituted in this lower concentration of uranyl acetate also gave good membrane detail when imaged after section contrasting.

Effects of radial shockwave therapy on the limb function of dogs with hip osteoarthritis

The objective of this study was to evaluate the effects of extracorporeal radial shock wave therapy on the hindlimb function of dogs suffering from hip osteoarthritis. Twenty-four client-owned dogs with hip osteoarthritis were investigated; 18 of them received radial shockwave therapy and six were left untreated as controls. Force plate analysis on a treadmill was used to assess the dogs' hindlimb function before treatment and four weeks after the last treatment, and the treated dogs were re-evaluated three and six months after the treatment. The parameters chosen for evaluation were peak vertical force and vertical impulse, and the calculated symmetry indices. In the treated dogs, differences between the ground reaction forces exerted by the right and left hindlegs disappeared four weeks after the treatment, whereas in the control dogs only the peak vertical force distribution changed significantly. The significant improvement in the treated dogs was confirmed by changes in the symmetry indices. Significant improvements in vertical impulse and peak vertical force were observed three months after the treatment.

Low-dose Tacrolimus/Sirolimus and Steroid Withdrawal in Heart Recipients Is Highly Efficacious

Heart transplant recipients treated with long-term calcineurin inhibitors (CNIs) experience significant nephrotoxicity and transplant vasculopathy. Signal proliferation inhibitors might prevent the development of transplant vasculopathy. In an open, prospective pilot study, 33 primary heart transplant recipients received tacrolimus (Tac) and sirolimus (rapamycin, Rapa) with steroids. To reduce both nephrotoxicity and transplant vasculopathy at the same time, both Tac and Rapa exposure was kept low (6 to 8 ng/ml). Steroids were withdrawn successfully from all patients within 6 months. Just one acute rejection occurred at 54 days post-transplant, resulting in 0.03 acute rejection episode per patient at 1-year (primary end-point) and 2-year follow-up. Transplant vasculopathy assessed by angiogram was absent at 2 years. Graft and patient survival were 100% at 1 and 2 years. Accordingly, the survival estimate for freedom from first acute rejection, transplant vasculopathy, graft loss or death was 0.97 at 1 and 2 years. The regimen was well tolerated with only 3 patients requiring a change of study medication. Mean serum creatinine increased during the first year but returned to baseline at 2 years.

Prognostic relevance of increased Rac GTPase expression in prostate carcinomas

Rac proteins of the Rho-like GTPase family, including the ubiquitous Rac1, the hematopoiesis-specific Rac2, and the least-characterized Rac3 play a major role in oncogenic transformation, tumor invasion and metastasis. However, the prognostic relevance of Rac expression in human tumors has not been investigated yet. In the present study, Rac protein expression was analyzed in benign secretory epithelium, high-grade prostatic intraepithelium neoplasia (HG-PIN), and prostate carcinomas of 60 R0-resected radical prostatectomy specimens by semiquantitative immunohistochemistry. Thus, Rac proteins were significantly strongly expressed in HG-PIN (P < 0.001) and prostate carcinomas (P < 0.001) when compared with benign secretory epithelium. Accordingly, all tumor tissues analyzed by isoform-specific real-time PCR (n = 7) exhibited significantly higher RNA expression levels of Rac (i.e. sum of Rac1 and Rac3 expression levels) than the respective benign counterparts (P = 0.018) and this appeared to result mainly from increased expression of the Rac3 isoform as verified by immunoblotting. Univariate analyses showed statistically significant associations of increased Rac protein expression in prostate cancer (P = 0.045), preoperative prostate-specific antigen levels (P = 0.044), pT stage (P = 0.002), and Gleason score (P = 0.001) with decreased disease-free survival (DFS). This prognostic effect of increased protein expression of Rac remained significant even in a multivariate analysis including all these four factors (relative risk = 3.22, 95% confidence interval = 1.04-10.00; P = 0.043). In conclusion, our data suggest that increased Rac protein expression in prostate cancer relative to the corresponding benign secretory epithelium is an independent predictor of decreased DFS and appears to result mainly from increased expression of the Rac3 isoform.

Approach to Detection in Laser-Induced Breakdown Spectroscopy

Gated detection with intensified detectors, e.g., ICCDs, is today the accepted approach for detection of plasma emission in laser-induced breakdown spectroscopy (LIBS). However, these systems are more cost-intensive and less robust than nonintensified CCDs. The objective of this paper is to compare, both theoretically and experimentally, the performance of an intensified (ICCD) and nonintensified (CCD) detectors for detection of plasma emission in LIBS. The CCD is used in combination with a mechanical chopper, which blocks the early continuum radiation from the plasma. The detectors are attached sequentially to an echelle spectrometer under the same experimental conditions. The laser plasma is induced on a series of steel samples under atmospheric conditions. Our results indicate that there is no substantial difference in the performance of the CCD and ICCD. Signal-to-noise ratios and limits of detection achieved with the CCD for Si, Ni, Cr, Mo, Cu, and V in steel are comparable or even better than those obtained with the ICCD. This result is further confirmed by simulation of the plasma emission signal and the corresponding response of the detectors in the limit of quantum (photon) noise.

Reproducible isolation of distinct, overlapping segments of the phosphoproteome

The ability to routinely analyze and quantitatively measure changes in protein phosphorylation on a proteome-wide scale is essential for biological and clinical research. We assessed the ability of three common phosphopeptide isolation methods (phosphoramidate chemistry (PAC), immobilized metal affinity chromatography (IMAC) and titanium dioxide) to reproducibly, specifically and comprehensively isolate phosphopeptides from complex mixtures. Phosphopeptides were isolated from aliquots of a tryptic digest of the cytosolic fraction of Drosophila melanogaster Kc167 cells and analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry. Each method reproducibly isolated phosphopeptides. The methods, however, differed in their specificity of isolation and, notably, in the set of phosphopeptides isolated. The results suggest that the three methods detect different, partially overlapping segments of the phosphoproteome and that, at present, no single method is sufficient for a comprehensive phosphoproteome analysis.

Identification of Borrelia burgdorferi ribosomal protein L25 by the phage surface display method and evaluation of the protein's value for serodiagnosis

The phage surface display technique was used to identify Borrelia burgdorferi antigens. By affinity selection with immunoglobulin G from pooled sera of six Lyme borreliosis (LB) patients, the ribosomal protein L25 was identified. The diagnostic value of L25 was investigated by an enzyme-linked immunosorbent assay, using sera from 80 LB patients and 75 controls, and the use of the protein resulted in a specificity of 99% and a 23% sensitivity, which qualify L25 as a useful antigen when combined with others.

Prognostic relevance of Tiam1 protein expression in prostate carcinomas

The Rac-specific guanine nucleotide exchange factor, Tiam1, plays a major role in oncogenicity, tumour invasion and metastasis but its usefulness as a prognostic marker in human cancer has not been tested yet. In the present study, Tiam1 expression was analysed in benign secretory epithelium, pre-neoplastic high-grade prostatic intraepithelium neoplasia (HG-PIN) and prostate carcinomas of 60 R0-resected radical prostatectomy specimens by semiquantitative immunohistochemistry. Tiam1 proved significantly overexpressed in both HG-PIN (P<0.001) and prostate carcinomas (P<0.001) when compared to benign secretory epithelium. Strong Tiam1 overexpression (i.e. ⩾3.5-fold) in prostate carcinomas relative to the respective benign prostatic epithelium was statistically significantly associated with disease recurrence (P=0.016), the presence of lymph vessel invasion (P=0.031) and high Gleason scores (GS) (i.e. ⩾7) (P=0.044). Univariate analysis showed a statistically significant association of strong Tiam1 overexpression with decreased disease-free survival (DFS) (P=0.03). This prognostic effect of strong Tiam1 overexpression remained significant in multivariate analysis including preoperative prostate-specific antigen levels, pT stage, and GS (relative risk= 3.75, 95% confidence interval=1.06–13.16; P=0.04). Together, our data suggest that strong Tiam1 overexpression relative to the corresponding benign epithelial cells is a new and independent predictor of decreased DFS for patients with prostate cancer.

Retropatellar chondromalacia associated with medial osteoarthritis after meniscus injury. One year of observations in sheep

BACKGROUND/AIMS

In an ovine meniscal repair model, the patellofemoral (PF) osteoarthritis due to a non-sutured tear or failed repair was investigated.

METHODS

A radial meniscus tear was either sutured with polydioxanone (PDS), with a slow degrading polylactide long-term suture(LTS) or left without treatment. Knee joint cartilage in the PF and medial compartment was evaluated compared to normal knees (healthy controls).

RESULTS

Retropatellar osteoarthritis in the non-sutured and sutured animals was intense in contrast to the control knees after 6 months in all groups (p < 0.001), and after 12 months in the PDS group (p < 0.001), LTS group and non-sutured animals (p < 0.05).

CONCLUSION

Non-sutured meniscus tears and failed repair lead fast to intense PF osteoarthritis corresponding with tibial damage of the injured compartment.

A Bioequivalence Study of Two Oral Desmopressin Tablet Formulations

The present study was carried out to test bioequivalence between two different oral desmopressin formulations. Sixty healthy volunteers were enrolled in the study and were randomly assigned to receive the test (T) and reference (R) drug in a two-period two-sequence, crossover, analyst-blinded study design. Subjects received an oral dose of 400 mug of desmopressin acetate separated by a wash-out period of at least 7 days. The area under the concentration-time curve (AUC) over 12 h in plasma and the maximum concentration (C(max)) were compared by analysis of variance (ANOVA) after log transformation. The mean ratios of the T to R drug were within the bioequivalence boundaries with mean values of 1.00 (90% CI: 0.87-1.14) and 1.03 (90% CI: 0.92-1.15) for AUC(0-t) and AUC(0-inf), respectively. For the C(max), the mean ratio of the T to R drug was 0.97 (90% CI: 0.87-1.08). The rate and the extent of oral desmopressin absorption were identical for both formulations. Hence, the desmopressin test tablet met all bioequivalence criteria of the marketed reference desmopressin tablet.

Influence of immunisation with Mycobacterium bovis bacillus Calmette-Guérin on the sensitisation to inhaled allergens after infection with respiratory syncytial virus

Respiratory syncytial virus (RSV) may play an important role in allergic diathesis by creating a Th2-type immune response. Mycobacterium bovis bacillus Calmette-Guérin (BCG) is known to induce a Th1-type immune response, but the association of BCG vaccination and the suppression of allergy development remain controversial. We investigated the influence of BCG vaccination on the immune response to RSV in a mouse model. Balb/c mice were BCG vaccinated, RSV infected and ovalbumin (OVA) challenged. Mice were sacrificed one, two and four weeks after allergen exposure. Bronchoalveolar lavage was performed. Alveolar macrophages and lymphocytes from spleens and lung-associated lymph nodes were investigated for cytokine production and cell proliferation. Serum was tested for allergen-specific immunoglobulin-E (IgE). Lung eosinophilia was diminished by BCG immunisation. OVA-specific serum IgE was increased regardless of prior BCG vaccination. Interleukin-4 secretion of spleen lymphocytes increased in BCG-vaccinated mice only one week after allergen exposure but was comparable to non-vaccinated mice at four weeks. The reactivity of spleen lymphocytes towards concanavalin-A to secrete interferon-gamma was increased in the vaccinated group at the end of the observation period. Interleukin-6 and tumour necrosis factor-alpha secretion of alveolar macrophages as well as proliferation of stimulated thoracic lymph node cells were increased and prolonged in vaccinated mice. BCG immunisation led to a local suppression of the allergic reaction within the lung. No reduction of systemic IgE production was observed. Further studies are necessary to determine a possible time dependence of BCG immunisation.

Enhanced acetylcholine-induced dilation in afferent arterioles in simvastatin-fed rats

OBJECTIVE

3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have been shown to increase renal blood flow and glomerular filtration rate independent of their lipid lowering effects. The purpose of this study was to determine the effect of simvastatin on acetylcholine-induced vasodilation in the renal microcirculation. The hypothesis of the study was that simvastatin would increase acetylcholine-induced vasodilation in the renal microcirculation.

METHODS

The hydronephrotic kidney preparation was used. On the day of the experiment the kidney was prepared for videomicroscopy and dose-response curves were done with acetylcholine and sodium nitroprusside (10(-10) M to 10(-5) M) in simvastatin-fed rats ??(n=8) and control rats (n=13). The vasodilator responses of afferent and efferent arterioles were directly quantitated using videomicroscopy. L-NAME; (N(omega)-nitro-L-arginine methyl ester) was also given in a group of simvastatin-fed rats (10(-5) M) to determine if it would block the acetylcholine (Ach)-induced vasodilation.

RESULTS

Simvastatin enhanced Ach-induced vasodilation in the afferent arteriole compared to control rat responses to Ach. At 10(-7) M, ACH caused a 31.6+/-7.2% increase from baseline diameter in the afferent arteriole in the simvastatin-fed rats compared to a 23+/-8.1% vasodilation in the control rats (p<0.05). There were no differences in the response to ACH in the efferent arteriole between the two groups. L-NAME completely abolished the ACH response in the simvastatin-fed rats.

CONCLUSIONS

The increase in renal blood flow and glomerular filtration rate observed with simvastatin may be due to its preglomerular vasodilator effects. This may be due to an increase in nitric oxide production.