[Ligamentous knee injuries in children and adolescents]. / Ligamentäre Kniegelenkverletzungen im Wachstumsalter.

Due to an increase in sporting activities, the number of injuries of the immature knee is continuously increasing. These injuries necessitate a special approach regarding the particular anatomical situation with open growth plates. Three of the most commonly occurring injuries are rupture of the anterior cruciate ligament, patella dislocation and meniscus injuries. The clinical results for conservative treatment of ruptures of the anterior cruciate ligament in the growth phase are inferior to operative treatment. Transepiphyseal reconstruction has been shown to be a safe treatment method and provides good clinical results. Therapy of patella instability in children has shown poor results and new surgical techniques have been introduced to perform an anatomical reconstruction of the medial patellofemoral ligament as well as to improve distal alignment. Isolated injuries to the meniscus are rare and discoid meniscus is a special phenomenon occurring in infancy. Meniscus injuries should be treated with primary sutures rather than resection. A discoid meniscus should be resected with extreme caution and anatomically reconstructed.

Dynamics of ultrathin V-oxide layers on Rh(111) in catalytic oxidation of ammonia and CO.

Catalytic oxidation of ammonia and CO has been studied in the 10(-4) mbar range using a catalyst prepared by depositing ultra-thin vanadium oxide layers on Rh(111) (θV ≈ 0.2 MLE). Using photoemission electron microscopy (PEEM) as a spatially resolving method, we observe that upon heating in an atmosphere of NH3 and O2 the spatial homogeneity of the VOx layer is removed at 800 K and a pattern consisting of macroscopic stripes develops; at elevated temperatures this pattern transforms into a pattern of circular VOx islands. Under reaction conditions the neighboring VOx islands become attracted by each other and coalesce. Similar processes of pattern formation and island coalescence are observed in catalytic CO oxidation. Reoxidation of the reduced VOx catalyst proceeds via surface diffusion of oxygen adsorbed onto Rh(111). A pattern consisting of macroscopic circular VOx islands can also be obtained by heating a Rh(111)/VOx catalyst in pure O2.

Arthroscopic popliteus bypass graft for posterolateral instabilities of the knee : A new surgical technique.

OBJECTIVE: An arthroscopic technique for the reconstruction of the posterolateral corner combined with posterior cruciate ligament (PCL) reconstruction was developed. INDICATIONS: Posterolateral rotational instabilities of the knee. Combined lesions of the PCL, the popliteus complex (PLT) and the posterolateral corner. Isolated PLT lesions lacking static stabilizing function. CONTRAINDICATIONS: Neuromuscular disorders; knee deformities or fractures; severe posterolateral soft tissue damage. SURGICAL TECHNIQUE: Six arthroscopic portals are necessary. Using the posteromedial portal, resect dorsal septum with a shaver. Visualize the PCL, the lateral femoral condyle and the posterolateral recessus with the PLT. Dissect the popliteomeniscal fibers; retract PLT until sulcus popliteus is visualized. Drill a 6-mm tunnel anteriorly into the distal third of the sulcus popliteus. Visualize femoral footprint of the PLT and place an anatomical drill tunnel. Pull the popliteus bypass graft into the knee and fix with bioscrews. Fix the reconstructed PCL. In cases of additional LCL injury, reconstruct LCL with autologous graft. POSTOPERATIVE MANAGEMENT: Partial weight-bearing for 6 weeks, range of motion exercises, quadriceps-strengthening exercises on postoperative day 1. Full extension allowed immediately with flexion limited to 20° for 2 weeks, to 45° for up to week 4, and to 60° up to week 6. Use a PCL brace for 3 months, running and squatting exercises allowed after 3 months. RESULTS: In the 35 patients treated, no technique-related complications. After 1 year, 12 patients had a mean Lysholm Score of 88.6 (± 8.7) points and a side-to-side difference in the posterior drawer test of 2.9 (± 2.2) mm (preoperative 13.3 [± 1.9] mm). CONCLUSION: Low complication risk and good and excellent clinical results after arthroscopic posterolateral corner reconstruction.

Loss of Drosophila pseudouridine synthase triggers apoptosis-induced proliferation and promotes cell-nonautonomous EMT.

Many developing tissues display regenerative capability that allows them to compensate cell loss and preserve tissue homeostasis. Because of their remarkable regenerative capability, Drosophila wing discs are extensively used for the study of regenerative phenomena. We thus used the developing wing to investigate the role played in tissue homeostasis by the evolutionarily conserved eukaryotic H/ACA small nucleolar ribonucleoprotein pseudouridine synthase. Here we show that localized depletion of this enzyme can act as an endogenous stimulus capable of triggering apoptosis-induced proliferation, and that context-dependent effects are elicited in different sub-populations of the silenced cells. In fact, some cells undergo apoptosis, whereas those surrounding the apoptotic foci, although identically depleted, overproliferate. This overproliferation correlates with ectopic induction of the Wg and JAK-STAT (Janus kinase-signal transducer and activator of transcription) mitogenic pathways. Expression of a p35 transgene, which blocks the complete execution of the death program and generates the so-called 'undead cells', amplifies the proliferative response. Pseudouridine synthase depletion also causes loss of apicobasal polarity, disruption of adherens cell junctions and ectopic induction of JNK (c-Jun N-terminal kinase) and Mmp1 (matrix metalloproteinase-1) activity, leading to a significant epithelial reorganization. Unexpectedly, cell-nonautonomous effects, such as epithelial mesenchymal transition in the contiguous unsilenced squamous epithelium, are also promoted. Collectively, these data point out that cell-cell communication and long-range signaling can take a relevant role in the response to pseudouridine synthase decline. Considering that all the affected pathways are highly conserved throughout evolution, it is plausible that the response to pseudouridine synthase depletion has been widely preserved. On this account, our results can add new light on the still unexplained tumor predisposition that characterizes X-linked dyskeratosis, the human disease caused by reduced pseudouridine synthase activity.

[Ligament bracing--augmented cruciate ligament sutures: biomechanical studies of a new treatment concept]. / "Ligament bracing"--die augmentierte Kreuzbandnaht: Biomechanische Grundlagen für ein neues Behandlungskonzept.

BACKGROUND: In the context of acute knee dislocations, suture repair of ruptured cruciate ligaments leads to good clinical results in 80% of cases. Disadvantages are low primary stability and subsequently secondary elongation of the sutured ligaments. In the present study, we compared primary stability of suture repair, reinforced by different suture augments, to cruciate ligament reconstruction. OBJECTIVE: The concept of ligament bracing with transosseous suture repair of the cruciate ligaments and additional suture augmentation is biomechanically superior to cruciate ligament reconstruction. MATERIAL AND METHODS: A total of 42 porcine knee joints divided into seven groups were examined. The stability of four different suture/augmentation combinations were compared to cruciate ligament reconstruction with human hamstring tendons. The investigational setup consisted of testing 1000 cycles with 20 N to 154 N load in a.-p. translation and 60° flexion. Elongation and load to failure were measured. RESULTS: Neither reconstruction (3.13 ± 1.65 mm; 362 ± 51 N) nor augmented suture repair (1.89-2.5 mm; 464-624 N) achieved the primary stability of the intact cruciate ligament (0.63 ± 0.34 mm, 1012 ± 91 N). In comparison to ligament reconstruction, all four augmented suture repairs showed minor elongation in the cyclic test and a higher load to failure. The isolated suture repair showed poor results (6.79 ± 4.86 mm, 177 ± 73 N). CONCLUSION: Augmented suture repair provides significantly higher stability compared with isolated suture repair and reconstruction with hamstring tendons. The concept of ligament bracing could be a promising future treatment option in acute knee dislocations. Clinical results remain to be seen.

[Ligament bracing--augmented primary suture repair in multiligamentous knee injuries]. / Ligament bracing--Augmentierte Primärnaht bei multiligamentären Verletzungen des Kniegelenks.

OBJECTIVE: Reconstruction of knee stability by primary ligament sutures and additional augmentation after knee dislocation. INDICATIONS: Acute knee dislocation Schenck type III and IV. Operative treatment should be performed within 7 days after injury. CONTRAINDICATIONS: Chronic instability after knee dislocation, refixable bony avulsions, critical soft tissue, infection, lack of compliance. SURGICAL TECHNIQUE: Supine position with electric leg holder. Short arthroscopic assessment of concomitant injuries. Schenck type III medial injuries and Schenck IV injuries: anteromedial parapatellar arthrotomy. Injuries type Schenck III lateral: anteromedian arthrotomy. Armoring of ligament stumps for transosseus sutures. Placement of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) drill tunnels. Extracortical diversion of the suture armorings and insertion of augmentation systems. Fixation of the PCL augmentation in 70-90° flexion. Fixation of the ACL augmentation in 20-30° flexion. Knotting of the transosseus ligament sutures. If necessary (postero-)lateral and/or medial stabilization. POSTOPERATIVE MANAGEMENT: Limited weight bearing with 20 kg for 6 weeks. Stabilizing brace (e.g., Hypex-Lite®, Albrecht) generally for 12 weeks. Mobilization under tension of the quadriceps muscle for 6 weeks. RESULTS: In total, 20 patients have been treated using the principle of "ligament bracing". So far 8 patients (aged 18-60 years, median 33 years) have been assessed with a follow-up of 10-15 months (median 12 months) postoperatively. In all, 6 patients showed stable knees with good results. Recurrent instability of the ACL was observed in 2 patients; the collateral ligaments and PCL were stable. For the evaluation the following scores were used: IKDC score, Tegner score, and Lysholm score. To objectify the data, stress radiography and physical examination were performed. Using the operative technique mentioned above, no complications occurred. During follow-up 2 patients reported a deficiency of flexion.

Knee injuries in children and adolescents.

As more children and adolescents are involved in sporting activities, the number of injuries to immature knees rises. We will focus on three entities: ruptures of the anterior cruciate ligament, patellar dislocation, and meniscal injuries. There is a trend in recent literature toward early reconstruction of the anterior cruciate ligament in children and adolescents. In this article, we will try to highlight the anatomic specialities and the diagnostic steps toward the correct diagnosis, review technical considerations and risks of the different surgical techniques, and present outcomes and offer a treatment recommendation. The treatment of patellar dislocation has changed considerably since we gained a better understanding of the unique anatomy of the patellofemoral joint. We will show diagnostic steps and risk factors for recurrent patellar dislocation, discuss conservative and different operative therapy options, and present a modified technique to achieve a dynamic reconstruction of the medial patellofemoral ligament without damage to the growth plates. Meniscal tears and discoid menisci are rare in comparison to the other injuries. We will herein explain what specialities in the anatomy should be considered in children and adolescents concerning the menisci, and present the diagnostic steps and treatment options available.

[Acute medial collateral ligament injuries of the knee: diagnostics and therapy]. / Akute mediale Seitenbandverletzung am Kniegelenk: Diagnostik und Therapie.

The medial collateral ligament complex (MCL) is the most commonly damaged ligamentous stabilizer of the human knee. The diagnostic algorithm comprises patient history, clinical examination and magnetic resonance imaging (MRI). It is important to distinguish between incomplete and complete ruptures of the MCL. For adequate treatment the classification and exact knowledge about concomitant injuries are important. A nonoperative treatment of incomplete ruptures (grades I and II) is widely accepted and usually results in a good clinical outcome but the treatment of complete ruptures (grade III) is a subject of controversy. Complete intraligamentous ruptures with a correct approximation of the stumps and intact dorsomedial joint capsule can also be treated nonoperatively with good and excellent results. In contrast, ruptures close to the abutment and bony avulsions tend to heal better through operative treatment. Dehiscence or dislocation of the ligament stumps in MRI is an indication for operative treatment. In the context of a multiligamentous injury or complex instability, the majority of authors suggest an operative stabilization. As the treatment of chronic instability can be challenging, the initial and adequate treatment of acute ruptures is of great importance.

Unexpected brain lesions in lactating Sprague-Dawley rats in a Two-generation Inhalation Reproductive Toxicity Study with pentafluoropropane (HFC-245fa).

The study presented was conducted following the reproductive study guideline OECD Guideline 416 Two-Generation Reproduction Toxicity Study. Sprague-Dawley rats were exposed to 2000, 10,000 and 50,000 ppm of HFC-245fa. There was an unexpected mortality of lactating dams in the medium and high dose group beginning at day 10 of lactation. Statistically significant histopathological alterations were observed in the cerebellum of a total of 9/30 females of the high dose group of the F0-generation and in 10/27 females of the high dose group of the F1-generation. In contrast there were no brain lesions found in males or non-pregnant females of all dose groups. Neuronal necrosis and degeneration in the cerebellar cortex were observed as the most severe finding. Furthermore vacuolation of the neuropil in different degrees was diagnosed in 7/30 females of the F0-generation and in 9/30 females of the F1-generation. Acute hemorrhages - in particular perivascular - occurred in 5/30 females of the F0- and in 5/30 females of the F1-generation indicating a disturbed vascular integrity. The main lesions found in the cerebrum were glial scars in the corpus callosum and restricted to 2/30 females of the F0-generation of the high dose group. The increased incidence of myocardial fibrosis and mononuclear cell infiltration in males - indicating myocarditis - was only seen in the F0-generation of the high dose group. Females of the F1-generation of the high dose group showed an increased incidence of minimal myocardial fibrosis. In summary, histopathology revealed that the brain, particularly the cerebellum, and to a minor degree the heart turned out to be the toxicological target organs of the substance. Presumably substance-related energy deprivation may be responsible for the observed changes. One of the metabolites, 3,3,3-trifluoropropanoic acid has been shown to be capable of causing this effect.

[Osteochondritis dissecans of the talus. Diagnosis and treatment]. / Osteochondrosis dissecans tali. Diagnostik und Therapie.

Osteochondritis dissecans of the talus (ODT) describes a special entity of osteochondral lesions of the talus (OLT) which has to be distinguished from acute traumatic lesions. Its exact etiology still remains uncertain with multiple predispositioning factors being discussed. Following the knee and elbow, the ankle joint with 4% is the third most affected joint. Early stages can often be treated conservatively. In case of an advanced stage or failure of conservative treatment, a variety of operative techniques are available, which can be used based on the patient and the stage.

[Treatment of bony avulsions of the posterior cruciate ligament (PCL) by a minimally invasive dorsal approach]. / Versorgung knöcherner hinterer kreuzbandausrisse über einen minimal-invasiven dorsalen zugang.

OBJECTIVE: Reduction and fixation of bony avulsions of the posterior cruciate ligament (PCL) through a minimally invasive dorsal approach to restore stability of the knee joint. Prevention of soft tissue damage through a minimally invasive procedure and achieving early functional rehabilitation by stable osteosynthesis. INDICATIONS: Bony tibial avulsions of the PCL and simple posteromedial tibial fractures. CONTRAINDICATIONS: Infections in or around the knee, critical soft tissue conditions and lack of patient compliance. OPERATION TECHNIQUE: Supine position, skin incision mediodorsal over the head of the medial gastrocnemius muscle. After dissection of soft tissue and superficial fascia the medial gasteocnemius muscle is retracted to the lateral side, nerves and vessels of the popliteal fossa are thereby protected. Incision of the posterior capsule from the tibial attachment, exposure of the fracture and the PCL, reduction of the fracture, fixation with two drill wires and definitive fixation with two cannulated screws. In case of multifragment fracture a suture anchor is used for fixation. POSTOPERATIVE MANAGEMENT: Partial weight bearing of 10-20 kg for 4-6 weeks and limitation of knee flexion up to 90° for 4 weeks. RESULTS: Between November 2010 and November 2011 three patients were treated with the new minimally invasive posteromedial approach to fix bony avulsions of the PCL. In two cases an osteosynthesis with two screws was performed and in the other patient a comminuted avulsion fracture was fixed with a suture anchor. In the latter patient the posterolateral corner was additionally augmented according to Larson with an autologous semitendinosus tendon. No intraoperative or postoperative complications could be observed. In all three patients an excellent fracture reduction without steps or gaps could be achieved. In two cases an early functional treatment protocol and in one case (suture anchor fixation plus augmentation of the posterolateral corner) a special postoperative PCL rehabilitation protocol was used. Good clinical results with stable knee joints could be achieved in all cases. The minimally invasive dorsal approach for the treatment of bony avulsions of the PCL was demonstrated to be safe and simple with a low complication rate.

[Minimally invasive augmentation of the medial collateral ligament with autologous hamstring tendons in chronic knee instability]. / Minimal-invasive augmentation des medialen kollateralbandes mit autologen hamstringsehnen bei chronischen instabilitäten am kniegelenk.

OBJECTIVE: Medial collateral ligament reconstruction in chronic unstable knees. INDICATIONS: Chronic instability of the medial collateral ligament (MCL) isolated or in combination with multiligament injuries. CONTRAINDICATIONS: Refixable bony avulsions, limited range of motion, arthrofibrosis, severe valgus deformity, infections, critical soft tissue, lack of patient compliance and open growth plates. SURGICAL TECHNIQUE: Harvesting of the contralateral semitendinosus tendon and preparation. Supine position with leg in electric leg holder. Oblique skin incision above the pes anserinus parallel to the tendons. Placement of drill hole distal to the tibial insertion of the hamstrings in the footprint of the MCL. Tapering and fixation of the transplant. Subfascial tunneling and femoral fixation of the transplant distally to the medial patellofemoral ligament (MPFL) origin in 30° flexion under fluoroscopic control. Tibial fixation of the dorsal portion of the transplant (POL) ventral to the semimembranosus tendon footprint in full extension. POSTOPERATIVE MANAGEMENT: Limited weight bearing with 20 kg for 4-6 weeks, stabilizing brace with limited range of motion 0/0/90°. RESULTS: A total of 9 patients with a median age of 39 (18-70) years received an augmentation of the MCL complex due to a chronic instability using the described technique. Follow-up examination was performed after 16 (11-56) months. All patients reported a stable knee. The median value of the Lysholm score at follow-up was 90 (72-96) points and the Tegner score prior to trauma was 4 (2-6) points and 3 (2-6) points during follow-up. No grade 2 or 3 instability could be observed during follow-up. There were no complications using the above mentioned technique.

A new analytical approach for the comprehensive characterization of polar xenobiotic organic compounds downgradient of old municipal solid waste (MSW) landfills.

Groundwater samples collected downgradient from a former municipal solid waste landfill near Berlin, Germany, were analyzed by GC-MS, HPLC-MS, and HPLC-NMR hyphenated techniques to comprehensively characterize the xenobiotic organic compounds (XOCs). The focus thereby was on the detection and identification of the polar XOCs which were analyzed in the extract obtained after separation of the unpolar components by pre-extraction. HPLC-NMR and HPLC-MS runs were used to identify polar XOCs on-line or to obtain preliminary structure information on the other XOCs. These compounds were then isolated by HPLC fractionation and their structures elucidated by off-line NMR and MS investigations. A variety of polar XOCs, products of the dye industry, degradation products of polyethylene glycol, and some heterocyclic compounds could be identified. Furthermore, a semi-quantitative estimation of the identified polar compounds is given.

[Rupture of the anterior cruciate ligament in growing children: surgical or conservative treatment? A systematic review]. / Die vordere Kreuzbandruptur im Wachstumsalter - operativ oder konservativ? Ein systematisches Review.

The aim of the study was to examine whether a rupture of the anterior cruciate ligament (ACL) in patients with open growth plates should be treated by surgery or conservatively. An electronic search was performed in MEDLINE, the Cochrane controlled trial register, Embase, and Medpilot. Ten studies including 154 patients were analyzed regarding conservative treatment and 55 studies including 935 patients regarding operative treatment. The mean age for the conservative and operative treatment groups was 12.3 (10-14.4) years and 13.3 (10-15.8) years, respectively. Summing up there were significantly better results concerning Lysholm score (95.5 vs 73.2; p<0.05), instability described by the giving way phenomenon (2.8 vs 89.5%; p<0.05), and regaining former sports activity level (91.2 vs 30.9%; p<0.05) in the operatively treated group. Relative risk for leg length differences more than 1 cm or axis deviation more than 3° after surgery was low (2.1%). Reruptures occurred in 3.8% of the cases. The analyzed data clearly show that operative treatment is superior to conservative management of ACL ruptures in children and adolescents.

Evaluation of reproductive/developmental and repeated dose (subchronic) toxicity and cytogenetic effects in rats of a roofing asphalt fume condensate by nose-only inhalation.

A Type III Built-up Roofing Asphalt (BURA) fume condensate was evaluated for subchronic systemic toxicity and reproductive/developmental toxicity screening in Wistar rats, by OECD protocol 422 and OECD cytogenetic protocol 474. Animals were exposed by nose-only inhalation to target concentrations of 30, 100 and 300 mg/m³ total hydrocarbons (actual concentrations, 30.0, 100.1 and 297.3 mg/m³). The study was performed to assess potential hazards from asphalt fumes to which humans could be exposed during application. No adverse effects were seen for spermology, reproductive or developmental parameters or early postnatal development of offspring from day 1 to 4 postpartum. BURA fume condensate did not induce any significant increases in micronucleus frequency in polychromatic erythrocytes of rat bone marrow nor was neurobehavioral toxicity observed at any dose. Systemic effects were slight and seen at doses above those measured at work sites. The systemic NOAEC of 100 mg/m³ for males was based on decreased body weight gain, food consumption and increased absolute and relative lung wet weight correlated with slight histological changes in the lung, primarily adaptive in nature at 300 mg/m³. The female NOAEC of 30 mg/m³ was based on a statistically significant increase in relative wet lung weight at higher doses, correlated with slight histopathologic effects in the lungs at the highest dose. However, no increase in relative lung weight was seen in breeding females at 100 mg/m³.

Advanced high-performance liquid chromatography method for highly polar nitroaromatic compounds in ground water samples from ammunition waste sites.

An advanced HPLC-photodiode array detection method for the determination of 12 selected highly polar nitroaromatic compounds in ground water samples of ammunition waste sites has been developed and validated. After solid-phase extraction the limits of detection were in the range 0.1-0.5 microg/l. To prove the applicability of the method to other polar nitroaromatic compounds the retention time of another 32 polar compounds under the specified chromatographic conditions were determined and their UV spectra recorded. To review the method, interlaboratory comparisons were performed with a spiked and a real ground water sample.

Drosophila alpha-1,4-glycosyltransferase (alpha-4GT1) inhibits reaper-mediated apoptosis in the eye.

In a genetic screen, alpha-4GT1 has been identified as a potential enhancer of Hairless-mediated cell death in the eye of Drosophila. alpha-4GT1 encodes an alpha-1,4-glycosyltransferase, known to catalyze the fifth step in a series of ceramide glycosylation events. As reported for other enzymes involved in the glycosylation of ceramide, alpha-4GT1 is strongly expressed during oogenesis and is deposited maternally in the egg. Moreover, the protein is enriched at cell membranes. Unexpectedly, overexpression of alpha-4GT1 does not enhance Hairless-mediated cell death; instead, Hairless enhancement is caused by an allele of Scutoid present on the alpha-4GT1 chromosome. Interestingly, the downregulation of alpha-4GT1 during eye development amplifies cell death induction by the pro-apoptotic gene reaper. Accordingly, overexpression of alpha-4GT1 represses reaper-induced cell death. Thus, alpha-4GT1 appears to be an inhibitor of apoptosis, as has previously been observed for other ceramide glycosylating enzymes, suggesting that it likewise contributes to ceramide anchoring in the membrane.

Collection, validation and generation of bitumen fumes for inhalation studies in rats Part 3: Regeneration of bitumen fumes, inhalation setup, validation.

Undertaking a chronic inhalation study on bitumen fume presents a challenge in terms of generating sufficient amounts of representative fume. The objective of the study described in this and in previous publications was to collect sufficient fume and use this to develop a laboratory-generated exposure atmosphere, for use in chronic inhalation toxicity studies in rats that resembles, as closely as possible, personal exposures seen in workers during road paving operation. To achieve this goal, atmospheric workplace samples were collected at road paving work sites and compared with bitumen fume condensate samples collected from the headspace of hot bitumen storage tanks. In Parts 1 and 2, we described the collection and analysis of workplace samples, the strategy for in-line extraction of a suitable fraction of bitumen fume collected from the headspace of a bitumen storage tank and the comparison of the collected condensate to the workplace samples. This paper (Part 3) describes the regeneration of bitumen fume for inhalation and the exposure setup used for inhalation studies.