Pain after use of the central third of the patellar tendon for cruciate ligament reconstruction: 33 patients followed 2-3 years

We performed reconstruction of the anterior cruciate ligament in 33 patients using the central third of the patellar tendon. In 20 patients we did an arthroscopies! ly-assisted procedure, while 13 patients had an additional mini-arthrotomy through the gap in the patellar tendon. After 2-3 years the subjective knee function, according to the Lysholm score, was excellent or good in 18 knees and fair or poor in 15 knees, mainly due to anterior knee pain. Although 18 patients complained about anterior knee pain, only 1 patient required further surgery. After the operatio the patella had a lower position. A flexion contractur was found in 7 patients, and 13 had heterotopic bon formation at the apex of the patella. Although stabilit was restored in 31 of the 33 reconstructed knees anterior knee pain was a frequent complicatior There were no correlations between the anterior kne pain and patellar height, flexion contracture or hetei otopic bone formation.     

Bilateral Mid-Diaphyseal Femoral Stress Fractures in the Elderly

Abstract Background: Osteoporosis is characterized by low bone density and poor bone mineralization. Mid-diaphyseal stress (insufficiency) fractures of the femur caused by osteoporosis are rare. The symptoms of these lesions are vague and confusing. The physician must be alert to the possibility of femoral shaft stress fractures when evaluating an elderly patient complaining of back, hip or leg pain. Case Study: A 72-year-old osteoporotic female patient with bilateral mid-diaphyseal stress fractures of the femur is reported. The diagnosis of femoral shaft stress fracture in the elderly is very difficult when based on physical findings and plain radiography only. A magnetic resonance imaging (MRI) scan or nuclear scintigraphy is necessary for early diagnosis. In the described case, the patient had an excellent result after surgical treatment with intramedullary nails. Conclusion: MRI or nuclear scintigraphy must be obtained to exclude the possibility of femoral shaft stress fractures in the elderly. In the absence of contraindications, surgery is the best solution for this kind of lesion.     

Resorbierbare Stents im infrainguinalen Gefäßabschnitt

Peripheral stents aim to support revascularization procedures for intravascular stenoses by mechanically preventing vessel recoil and counteracting the pathophysiological process of luminal renarrowing triggered by procedural injury to the vessel wall. Despite improvements in stenting techniques and concomitant medication, repeated intervention due to target lesion restenosis is necessary in a significant percentage of patients. The permanent presence of an artificial implant plays a prominent role in the discussion of the mechanisms causing in-stent restenosis. Permanent metallic implants pose the risk of a continuous interaction between a non-absorbable stent and surrounding tissue, leading to physical irritation, long-term endothelial dysfunction, or chronic inflammatory reactions. In addition, there is a risk of stent fracture due to external mechanical forces. To overcome these shortcomings, stenting technology has moved towards the development of temporary implants composed of biocompatible materials which mechanically support the vessel during the period of high risk for recoil, and then completely degrade in the long-term. This removes a potential trigger for late restenosis.     

The role of intracellular calcium stores in motilin induced contractions of the longitudinal muscle of the rabbit duodenum

Summary The contraction of longitudinal muscle strips of the rabbit duodenum in response to motilin and acetylcholine was investigated in normal and high K⁺-solutions in the presence and absence of external calcium, in order to demonstrate the existence of pharmaco-mechanical coupling for motilin and to examine whether the peptide mobilizes calcium from an intracellular store. In depolarized smooth muscle (140 mM K⁺), motilin (3.2×10⁹ –1×10^–7 M) and acetylcholine (1×10^–5 M) were still capable of causing a considerable, transient, concentration-dependent contraction in the presence of Ca²⁺. The extra-contraction to motilin was not blocked by tetrodotoxin (1 g/ml) nor by atropine (10^–7 M), but acetylcholine (10^–5 M) was blocked by atropine. Verapamil (10^–7 M) could selectively block the K⁺ contraction without affecting the extra agonist contraction. Nitroprusside was ineffective up to 10^–4 M in high K⁺-solutions, but in normal Hepes-buffer it caused a concentration-dependent rightward shift of the concentration-response curve of motilin and acetylcholine contractions. In a calcium-depleted medium, high K⁺-depolarized muscle strips were still responsive to motilin and acetylcholine, but higher concentrations (10^–6 M) were needed than in the presence of calcium and the contractions reached only 57 +- 11% and 74 +- 9% respectively of the maximal contraction in 1.2 mM Ca²⁺ containing solutions. The response to motilin (10^–6 M) was not only smaller than that to acetylcholine (10^–5 M), it also faded more rapidly with time. The response to one agonist could not be repeated except by using a higher concentration of the same or the other agonist, and the magnitude of this second response depended upon the dose used in the first one. We conclude that pharmaco-mechanical coupling exists for motilin and that this peptide is able to elicit contractions by mobilization of calcium from an intracellular store. This store overlaps with the one used by acetylcholine. Our experiments also reinforce the hypothesis that in the rabbit motilin exerts a direct action upon smooth muscle cells.     

Distinct effects of amantadine and memantine on dopaminergic transmission in the rat striatum

Striatal glutamatergic inputs are known to participate in the modulation of dopaminergic transmission. Accordingly, the non-competitive N-methyl-D-aspartate receptor antagonists memantine and amantadine increase striatal dopamine levels, the latter being widely used in Parkinson's disease therapy. Based on our previous work revealing increased function of dopamine receptors and dopamine transporter after amantadine treatment, we studied the effects of repeated memantine administration on dopaminergic neurotransmission. On rat striatal membranes, dopamine-stimulated [(35)S]GTPgammaS binding was significantly reduced (20%) after 2 days injection with memantine (20 mg/kg per day, i.p.) but not after longer treatments (4 or 7 days). Evaluation of [(3)H]SCH 23390 and [(3)H]spiperone specific bindings only revealed a significant increase in D1 receptor density after 4 or 7 days treatment. Finally, none of these treatments were found to change the activity of the neuronal dopamine transporter in striatal synaptosomes. This shows that amantadine and memantine differentially affect striatal dopaminergic transmission, which could indicate that these two related aminoadamantanes display distinct pharmacodynamic properties.     

Effect of carrier priming on immunogenicity of saccharide-protein conjugate vaccines

Previous studies with saccharide-protein conjugates have demonstrated that antibody responses to the saccharide can be improved by the preexistence of carrier immunity. Here we report that prior exposure to the carrier protein can either enhance or suppress antibody response to polysaccharides administered in saccharide-protein conjugates. A dose-dependent role for carrier priming in the antisaccharide antibody response to three saccharide-protein conjugate vaccines, i.e., a Streptococcus pneumoniae type 4 polysaccharide-tetanus toxoid (TT) conjugate (PS4TT), a Neisseria meningitidis group C polysaccharide-TT conjugate (MenCTT), and a N. meningitidis group C oligosaccharide-diphtheria mutant toxin conjugate (MenCCRM), was investigated. The results showed that an increase in the antipolysaccharide antibody response could be obtained for both PS4TT and MenCTT but not for MenCCRM with low-dose carrier priming (0.025 to 0.25 microgram). However, suppression of the antipolysaccharide antibody response was observed with the PS4TT and MenCTT vaccines with high-dose (25-micrograms) carrier priming. There was no suppression effect with MenCCRM. The increase in the antipolysaccharide antibody response was shown to be restricted to the immunoglobulin G1 (IgG1) subclass, whereas suppression with high-dose carrier priming affected all antipolysaccharide subclass antibodies induced by PS4TT (IgG1, IgG2b, and IgG3) and only two of the four subclass antibodies induced by MenCTT (IgG2a and IgG2b). The increase in the antipolysaccharide antibody response was also present at the antipolysaccharide IgM antibody level but was not observed at the anti-carrier IgG antibody level.     

Function and structure of pressurized and perfused porcine carotid arteries: effects of in vitro balloon angioplasty

In this report we describe the application of an in vitro pressure-perfusion system for study of functional/structural changes after in vitro balloon dilation injury. Pig carotid arteries were perfused at P = 100 mm Hg and Q = 100 ml/min, balloon angioplastied (BA), and cultured under these hemodynamic conditions for 4 or 8 days (n = 5 BA and 6 controls for each time point). To assess endothelial function, outer diameter changes in response to bradykinin (BK) were measured daily. Remodeling was determined from the shift in pressure-passive diameter relation, as obtained after papaverine addition. Arterial samples were processed for histology. Control arteries showed spontaneous tone, BK-induced relaxation, and inward remodeling that was more pronounced at day 8 (ratio end-to-start passive diameter at P = 100 mm Hg, 0.69 +/- 0.04; P < 0.001) than at day 4 (0.85 +/- 0.03, P = 0.03). Intimal hyperplasia was detectable in these control vessels at day 8 with accumulation of alpha-smooth muscle actin-positive cells around the lumen. Angioplasty caused ruptures and dissections and abolished tone that returned after 5 days of perfusion along with BK-dependent relaxation. No significant inward remodeling or intimal hyperplasia was observed at day 8 after angioplasty. Thus, BA inhibits remodeling, which occurs after in vitro perfusion of conductance arteries.     

Contribution of magnetic resonance microscopy in the 12-week neurotoxicity evaluation of carbonyl sulfide in Fischer 344 rats

In this carbonyl sulfide (COS) study, magnetic resonance microscopy (MRM) and detailed light microscopic evaluation effectively functioned in parallel to assure that the distribution and degree of pathology in the brain was accurately represented. MRM is a powerful imaging modality that allows for excellent identification of neuroanatomical structures coupled with the ability to acquire 200 or more cross-sectional images of the brain, and the ability to display them in multiple planes. F344 rats were exposed to 200-600 ppm COS for up to 12 weeks. Prior to MRM, rats were anesthetized and cardiac perfused with McDowell Trump's fixative containing a gadolinium MR contrast medium. Fixed specimens were scanned at the Duke Center for In Vivo Microscopy on a 9.4 Tesla magnetic resonance system adapted explicitly for microscopic imaging. An advantage of MRM in this study was the ability to identify lesions in rats that appeared clinically normal prior to sacrifice and the opportunity to identify lesions in areas of the brain which would not be included in conventional studies. Other advantages include the ability to examine the brain in multiple planes (transverse, dorsal, sagittal) and obtain and save the MRM images in a digital format that allows for postexperimental data processing and manipulation. MRM images were correlated with neuroanatomical and neuropathological findings. All suspected MRM images were compared to corresponding H&E slides. An important aspect of this study was that MRM was critical in defining our strategy for sectioning the brain, and for designing mechanistic studies (cytochrome oxidase evaluations) and functional assessments (electrophysiology studies) on specifically targeted anatomical sites following COS exposure.