Empfehlungen der AG Klinische Geweberegeneration zur Behandlung von Knorpelschäden am Kniegelenk

The Working Group of the German Orthopedic and Trauma Society (DGOU) on Tissue Regeneration has published recommendations on the indication of different surgical approaches for treatment of full-thickness cartilage defects in the knee joint in 2004, 2013 and 2016. Based upon new scientific knowledge and new developments, this recommendation is an update based upon the best clinical evidence available. In addition to prospective randomised controlled clinical trials, this also includes studies with a lower level of evidence. In the absence of evidence, the decision is based on a consensus process within the members of the working group.The principle of making decision dependent on defect size has not been changed in the new recommendation either. The indication for arthroscopic microfracturing has been reduced up to a defect size of 2 cm² maximum, while autologous chondrocyte implantation is the method of choice for larger cartilage defects. Additionally, matrix-augmented bone marrow stimulation (mBMS) has been included in the recommendation for defects ranging from 1 to 4.5 cm². For the treatment of smaller osteochondral defects, in addition to osteochondral transplantation (OCT), mBMS is also recommended. For larger defects, matrix-augmented autologous chondrocyte implantation (mACI/mACT) in combination with augmentation of the subchondral bone is recommended.

[Significance of Matrix-augmented Bone Marrow Stimulation for Treatment of Cartilage Defects of the Knee: A Consensus Statement of the DGOU Working Group on Tissue Regeneration]

Surgical principles for treatment of full-thickness cartilage defects of the knee include bone marrow stimulation techniques (i.e. arthroscopic microfracturing) and transplantation techniques (i.e. autologous chondrocyte implantation and osteochondral transplantation). On the basis of increasing scientific evidence, indications for these established therapeutical concepts have been specified and clear recommendations for practical use have been given. Within recent years, matrix-augmented bone marrow stimulation has been established as a new treatment concept for chondral lesions. To date, scientific evidence is limited and specific indications are still unclear. The present paper gives an overview of available products as well as preclinical and clinical scientific evidence. On the basis of the present evidence and an expert consensus from the "Working Group on Tissue Regeneration" of the German Orthopaedic and Trauma Society (DGOU), indications are specified and recommendations for the use of matrix-augmented bone marrow stimulation are given. In principle, it can be stated that the various products offered in this field differ considerably in terms of the number and quality of related studies (evidence level). Against the background of the current data situation, their application is currently seen in the border area between cell transplantation and bone marrow stimulation techniques, but also as an improvement on traditional bone marrow stimulation within the indication range of microfracturing. The recommendations of the Working Group have preliminary character and require re-evaluation after improvement of the study situation.

[Treatment of Osteochondral Lesions in the Ankle: A Guideline from the Group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology (DGOU)]

Background: Osteochondral lesions (OCL) of the ankle are a common cause of ankle pain. Although the precise pathophysiology has not been fully elucidated, it can be assumed that a variety of factors are responsible, mainly including traumatic events such as ankle sprains. Advances in arthroscopy and imaging techniques, in particular magnetic resonance imaging (MRI), have improved the possibilities for the diagnosis of OCLs of the ankle. Moreover, these technologies aim at developing new classification systems and modern treatment strategies. Material and Methods: This article is a review of the literature. Recommendations of the group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology (DGOU) for the treatment of OCLs of the ankle are presented. The review gives a concise overview on the results of clinical studies and discusses advantages and disadvantages of different treatment strategies. Results: Non-operative treatment shows good results for selected indications in children and adolescents, especially in early stages of osteochondritis dissecans (OCD). However, surgical treatment is usually indicated in OCLs in adolescents and adults, depending on the size and location of the lesion. Various arthroscopic and open procedures are frequently employed, including reattachment of the fragment, local debridement of the lesion with fragment removal and curettage of the lesion, bone marrow-stimulation by microfracture or microdrilling (antegrade or retrograde), and autologous matrix-induced chondrogenesis (AMIC®) - with or without reconstruction of a subchondral bone defect or cyst by autologous cancellous bone grafting. Isolated subchondral cysts with an intact cartilage surface can be treated by retrograde drilling and possibly additional retrograde bone grafting. For larger defects or as salvage procedure, osteochondral cylinder transplantation (OATS® or Mosaicplasty®) or matrix-induced autologous chondrocyte transplantation (MACT) are recommended. Transplantation of so-called (osteochondral) mega grafts, such as autologous bone grafts or allografts, are used for very large osteochondral defects that cannot be reconstructed otherwise. Implantation of the so-called "small metal implants" - such as HemiCAP Talus® - is reserved for selected cases after failed primary reconstruction. Corrective osteotomies are indicated in accompanying axial malalignments. Conclusions: There are several different treatment strategies for OCLs, but clinical studies are rare and evidence is limited. Therefore, interventional studies, e.g. randomised controlled trials (RCTs), but also observational studies, e.g. based on data of the Cartilage Registry of the German Society of Orthopaedics and Traumatology (www.knorpelregister-dgou.de), are needed and are recommended by the authors.

Periodontal ligament cells as alternative source for cell-based therapy of tendon injuries: in vivo study of full-size Achilles tendon defect in a rat model

Tendon's natural healing potential is extremely low and inefficient, with significant dysfunction and disability due to hypocellularity and hypovascularity of tendon tissues. The application of stem cells can aid in significantly enhanced repair of tendon rupture; therefore, the main aim of this study is to assess the potential of using periodontal ligament cells (PDL), usually obtained from patients undergoing orthodontic treatment, as a novel cell source for cell-based therapy for tendon injuries in a clinically relevant rat full-size Achilles tendon defect. In addition, the study compares the differences between the healing effects of Achilles tendon-derived cells (AT) versus PDL and, hence, comprises of four experimental groups, native tendon (NT), empty defect (ED), PDL and human AT (hAT). The tendon healing in each group was assessed in the late remodelling phase at 16 weeks after surgery using a combination of methods, including evaluation of gross morphological appearance; various histological and immunohistological stainings; and detailed analyses of cell morphometry. Based on these outcome measures, PDL cell-implanted tendons exhibited not only advanced tissue maturation, less ectopic fibrocartilage formation, more organised collagen fibres, tendon matrix expression corresponding to the final healing stage, and better cell-morphometry parameters when compared with the ED group, but were also very similar to the tendons treated with hAT-derived cells. Taken together, our study clearly demonstrates the feasibility of using PDL cells as a novel cell source for tendon repair and strongly recommends this cell type for the future development of innovative regenerative applications for treatment of different tendon or ligament pathologies.

Autologous chondrocyte implantation (ACI) for cartilage defects of the knee: A guideline by the working group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Trauma (DGOU)

BACKGROUND

Autologous chondrocyte implantation (ACI) is an established and well-accepted procedure for the treatment of localised full-thickness cartilage defects of the knee.

METHODS

The present review of the working group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Trauma (DGOU) describes the biology and function of healthy articular cartilage, the present state of knowledge concerning therapeutic consequences of primary cartilage lesions and the suitable indication for ACI.

RESULTS

Based on best available scientific evidence, an indication for ACI is given for symptomatic cartilage defects starting from defect sizes of more than three to four square centimetres; in the case of young and active sports patients at 2.5cm(2), while advanced degenerative joint disease needs to be considered as the most important contraindication.

CONCLUSION

The present review gives a concise overview on important scientific background and the results of clinical studies and discusses the advantages and disadvantages of ACI.

LEVEL OF EVIDENCE

Non-systematic Review.

Scaffold-free Scleraxis-programmed tendon progenitors aid in significantly enhanced repair of full-size Achilles tendon rupture

Aim: Currently there is no effective approach to enhance tendon repair, hence we aimed to identify a suitable cell source for tendon engineering utilizing an established clinically relevant animal model for tendon injury. Materials & methods: We compared, by in-depth histomorphometric evaluation, the regenerative potential of uncommitted human mesenchymal stem cells (hMSC) and Scleraxis (Scx)-programmed tendon progenitors (hMSC-Scx) in the healing of a full-size of rat Achilles tendon defect. Results: Our analyses clearly demonstrated that implantation of hMSC-Scx, in contrast to hMSC and empty defect, results in smaller diameters, negligible ectopic calcification and advanced cellular organization and matrix maturation in the injured tendons. Conclusion: Scaffold-free delivery of hMSC-Scx aids in enhanced repair in a clinically translatable Achilles tendon injury model.

Primary stability of rotator cuff repair: can more suture materials yield more strength?

INTRODUCTION

It remains unclear if the increased biomechanical stability of the double-row repair is solely a result of the technique itself or due to the greater number of utilized materials. This study analyses the various rotator cuff (RC) repair interfaces and the influence of doubling the number of suture knots, stitch techniques and suture anchors on the primary stability of the RC reconstruction.

MATERIALS AND METHODS

Established cyclic testing protocols were used to test the primary stability of the knot interface with a Duncan loop and Roeder knot, the tendon-to-suture interface with a single-stitch and Mason-Allen-stitch and the anchor-to-bone interface with OPUS Magnum 2® and BioCorkscrew® anchors. After doubling the materials, the interfaces were tested again and compared to the yielded solitary values. The maximum failure loads (Fmax), clinical failure (CF), system displacement (SD) and modes of failure were recorded.

RESULTS

Doubling the amount of knots, stitches and suture anchors improved almost all interface parameters. For example, Fmax, CF and SD of the Roeder knot could be significantly improved from 142.5 N to 256.7 N, from 82.5 N to 155.0 N and from 0.45 mm to 0.20 mm, respectively. The Mason-Allen stitch's Fmax improved from 196.4 N to 324.9 N, and CF from 94.25 N to 139.8 N, with almost identical SD of 0.81 mm and 0.84 mm. Bio-Corkscrew® Fmax improved from 232.5 N to 317.5 N, CF from 182.5 N to 210 N, and SD from 0.85 mm to 0.64 mm.

CONCLUSION

Doubling the number of knots, stitches and suture anchors increases the primary stability of the various RC repair interfaces and may result in RC rerupture rate reduction. Furthermore, this study suggests that a suture anchor loaded with two or three sutures may yield the same primary stability as two or three suture anchors loaded with a single suture. This in vitro biomechanical study focuses solely on the rotator cuff interfaces at time zero; the biological healing process was therefore not analysed and requires further investigation.

CLINICAL RELEVANCE

Improved primary stability by increased number of suture materials may reduce rate of RC rerupture.

[Autologous chondrocyte implantation (ACI) for cartilage defects of the knee: a guideline by the working group "Tissue Regeneration" of the German Society of Orthopaedic Surgery and Traumatology (DGOU)]

Autologous chondrocyte transplantation/implantation (ACT/ACI) is an established and recognised procedure for the treatment of localised full-thickness cartilage defects of the knee. The present review of the working group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology (DGOU) describes the biology and function of healthy articular cartilage, the present state of knowledge concerning potential consequences of primary cartilage lesions and the suitable indication for ACI. Based on current evidence, an indication for ACI is given for symptomatic cartilage defects starting from defect sizes of more than 3-4 cm2; in the case of young and active sports patients at 2.5 cm2. Advanced degenerative joint disease is the single most important contraindication. The review gives a concise overview on important scientific background, the results of clinical studies and discusses advantages and disadvantages of ACI.

The accuracy of digital templating: a comparison of short-stem total hip arthroplasty and conventional total hip arthroplasty

PURPOSE

Selection of the correct femoral stem size is crucial in total hip arthroplasty for an uncomplicated implantation and good initial stability. Pre-operative templating has been shown to be a valuable tool in predicting the correct implant size. For short-stem total hip arthroplasty (SHA), which recently is increasingly used, it is unknown if templating can be performed as reliable as conventional total hip arthroplasty (THA).

METHODS

A total of 100 hip arthroplasties, 50 with SHA and 50 with THA, were templated by four orthopaedic surgeons each. The surgeons had different levels of professional experience and performed a digital template of the acetabular and femoral component on the pre-operative radiographs. The results were compared with the truly inserted implant size.

RESULTS

For the femoral stems the average percentage of agreement (± 1 size) was 89.0 % in SHA and 88.5 % in THA. There was no significant difference among surgeons in the accuracy of templating the correct stem size and no significant difference between templating SHA and THA. For the acetabular component the average percentage of agreement (± 1 size) was 75.8 %. However, the more experienced surgeons showed a significant higher accuracy for templating the correct cup size than the less experienced surgeons.

CONCLUSION

Digital templating of SHA can predict the stem sizes as accurately as conventional THA. Therefore digital templating is also recommendable for SHA, as it helps to predict the implant size prior to surgery and thereby might help to avoid complications.

Lunar phase does not influence perioperative complications in total hip arthroplasty

INTRODUCTION

Lunar calendars, publishing recommendations for daily life, are gaining more and more attention in Germany, where 10.5% of the population believe in lunar effects on disease. A widespread and often heard belief is that a full moon has the most negative effects on surgical outcome. The present study evaluates the effects of lunar phase on perioperative complications in total hip arthroplasty.

MATERIAL AND METHODS

We performed a retrospective study with 305 patients being provided with a primary hip arthroplasty. To identify possible influences of the lunar phase on perioperative complications we investigated data such as operation length, blood loss and course of C-reactive protein that were collected during the patients' stay in the hospital and allocated them to moon illumination.

RESULTS

There were no significant differences in all collected data concerning the lunar phase (p > 0.05). Although not statistically significant, there were fewer operations during the full moon phase.

CONCLUSIONS

Therefore there is no evidence that lunar phase has an effect on perioperative complications in total hip arthroplasty. Fewer, though not significantly fewer, operations were performed during the full moon phase. Although this was not a prospective randomized trial, the statistical magnitude of the results does not support any recommendations for scheduling patients for total hip arthroplasty at any particular day of the lunar phase.

Sports activity after short-stem hip arthroplasty

BACKGROUND

No data are available about the sports activity of patients with bone-conserving short-stem hip implants.

HYPOTHESIS

Patients can return to a good level of sports activity after implantation of a short-stem hip implant.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The sports activity level of 68 patients (76 hips) after short-stem hip arthroplasty was assessed for a minimum of 2 years after implantation. In addition to the clinical examination, a detailed evaluation of the patients' sports pattern was obtained. Furthermore, the results were analyzed with regard to gender (female and male) and age (≤55 and >55 years).

RESULTS

After a mean of 2.7 years, patients showed a Harris Hip Score (HHS) of 93.6, a Western Ontario and McMaster Universities Arthritis Index (WOMAC) score of 9.5, and a University of California, Los Angeles (UCLA) activity score of 7.6, with each individual participating on average in 3.5 different disciplines after surgery compared with 3.9 before surgery. High-impact activities decreased significantly postoperatively, whereas low-impact activities increased significantly. The duration of the sports activities remained stable, while the frequency actually increased. In contrast, men participated preoperatively in more sports than women (4.3 men vs 3.3 women). However, because of a pronounced decrease in high-impact activities by men, both genders participated in an equal number of sports postoperatively (3.5 men vs 3.5 women). Finally, 45% (n = 31) reported at least one activity that they missed. Most of them were disciplines with an intermediate- or high-impact level.

CONCLUSION

Patients with a short-stem hip implant can return to a good level of activity postoperatively. Participation in sports almost reached similar levels as preoperatively but with a shift from high- to low-impact activities. This seems desirable from a surgeon's point of view but should also be communicated to the patient before hip replacement.

[Locoregional deformation pattern of the patellar cartilage after different loading types - high-resolution 3D-MRI volumetry at 3 T in-vivo]

PURPOSE

To analyze locoregional deformation patterns indicative of contact areas in patellar cartilage after different loading exercises.

MATERIALS AND METHODS

7 healthy patellae were examined in-vivo before and immediately after standardized loading (kneeling, squatting or knee bends) and after 90 minutes of rest using a sagittal 3D-T1-w FLASH WE sequence (22 msec/ 9.8 msec/ 15°/ 0.3 × 0.3 × 1.5 mm³) at 3 T. After cartilage segmentation and 3D reconstruction, voxel-based and global precision errors (PR) were calculated. The former were used to determine significant differences in local cartilage thickness. Voxel-based 2σ-thickness difference maps were calculated to visualize locoregional deformation patterns. Global changes in volume (Vol), mean thickness (mTh) and cartilage-bone-interface area (CBIA) were calculated.

RESULTS

The voxel-based PR depended on cartilage thickness (D) ranging from 0.12 - 0.35 mm. For D ≥ 1 mm the RF was < 0.31 mm (< voxel size), and for D ≥ 2 mm, the RF was < 0.22 mm. The global PR was 83 mm³ (2.4 %) for Vol, 0.06 mm (2.0 %) for mTh and 16 mm² (1.4 %) for CBIA. The focal cartilage deformation equaled 14 % of the local thickness reduction. The deformation areas were oval and located in the peripheral medial (more vertically oriented, all exercises) and caudo-lateral (more horizontally oriented, kneeling and knee bends) aspects of the patella and were least pronounced in knee bends. Significant changes for Vol/mTh ranged from 2.1 to 3.7 %.

CONCLUSION

This MRI-based study is the first to identify in-vivo voxel-based patellar cartilage deformation patterns indicating contact and loading zones after kneeling and squatting. These zones are anatomically and functionally plausible and may represent areas where stress induced degeneration and subsequent OA can originate. The data may facilitate understanding of individual knee loading properties and help to improve and validate biomechanical models for the knee.

Alcohol pretreatment increases hepatic and pulmonary injury in experimental pancreatitis

BACKGROUND

Systemic complications including pancreatitis-associated lung injury (PALI) are critical factors that determine the outcome of severe necrotizing pancreatitis (SNP). The aim of the present study was to evaluate the role of chronic alcohol exposure on the development of PALI.

METHODS

48 rats were fed either a Lieber deCarli control or alcohol diet for 6 weeks. After completion, SNP was induced by intraductal infusion of bile salt followed by intravenous infusion of cerulein over 6 h. Control animals received i.v. Ringer's solution. Intravital microscopy of the liver was performed 6 h after induction of SNP to evaluate hepatic perfusion and leukocyte adhesion. Serum parameters, edema, inflammation, and histological changes were evaluated at 12 h. IL-6 levels were evaluated in portal venous and systemic blood as well as in pancreatic tissue homogenates.

RESULTS

Alcohol pretreatment did not affect pancreatic injury in SNP. PALI was aggravated after alcohol ingestion. These animals showed increased hepatic microcirculatory disturbances, compared to SNP alone. IL-6 showed peak levels in SNP with alcohol pretreatment, although they were also elevated in SNP alone. Systemic levels of IL-6 were higher than in the portal vein.

CONCLUSION

In SNP, alcoholic pretreatment increases pulmonary damage, while pancreatic injury is identical. The liver seems to participate in this effect by increased hepatic cytokine release.

[Microcirculatory disturbance in the course of acute pancreatitis]

Although as many studies are sacrificed to acute pancreatitis (AP), the pathogenesis of the disease remains undiscovered. The microcirculatory disturbances during AP as a cause of necrotic changes in the parenchyma of the gland, described first time by Panum in 1886, have become again a very attractive theory. In the last decades, several studies were done to prove that microcirculatory impairment plays a crucial role in pathogenesis of severe AP. It had been proved that many mediators play important roles in this process including nitric oxide and endothelin balance. Vasoconstriction and vasodilatation named "vascular game" caused by cytokine accumulation and lower oxygenation of the tissue gives very interesting basis for theories about creating pancreatic necrosis. The severity of the course of AP also determinates damage of the microcirculation of the lungs, the liver and the bowels which leads to SIRS, MODS and MOF. The new experimental dates seems to be very promising and can became a basis for developing a new strategy of treatment in the most severe cases of AP. In this article we present up-to-date information about these theories and concepts.

[The dislocated shoulder prosthesis--an avoidable disaster?]

Instability after shoulder arthroplasty is a common problem, even though complete dislocations are rare. A distinction can be made between vertical and horizontal instabilities. The most common type of vertical instability is superior migration of the humeral head caused by rotator cuff insufficiency; the shoulder prosthesis should be changed for an inverse prosthesis if the patient is symptomatic. Horizontal instabilities can certainly lead to acute dislocation, but it is far more common for them to result in eccentric loading of the glenoid and in turn to increased wear and loosening. When a prosthesis is first implanted it is essential to reproduce the original bony situation before the deformity caused by arthrosis, arthritis or fracture, as this is the only way to prevent instability. This requires careful preoperative planning including evaluation of CT or MRI scans so that during the operation it will be possible, for example, to reorientate an eccentrically torn glenoid using a bone graft or by eccentric reaming and restore the original torsion. At least as much importance attaches to the treatment of the soft tissue, meaning careful release and later closure of the rotator cuff and capsule complex, as to the bony situation. In the authors' own institution 190 prostheses were implanted between 2000 and 2006 and there were three dislocations (1.6%).

Keratin 8 sequence variants in patients with pancreatitis and pancreatic cancer

Keratin 8 (KRT8) is one of the major intermediate filament proteins expressed in single-layered epithelia of the gastrointestinal tract. Transgenic mice over-expressing human KRT8 display pancreatic mononuclear infiltration, interstitial fibrosis and dysplasia of acinar cells resulting in exocrine pancreatic insufficiency. These experimental data are in accordance with a recent report describing an association between KRT8 variations and chronic pancreatitis. This prompted us to investigate KRT8 polymorphisms in patients with pancreatic disorders. The KRT8 Y54H and G62C polymorphisms were assessed in a cohort of patients with acute and chronic pancreatitis of various aetiologies or pancreatic cancer originating from Austria (n=16), the Czech Republic (n=90), Germany (n=1698), Great Britain (n=36), India (n=60), Italy (n=143), the Netherlands (n=128), Romania (n=3), Spain (n=133), and Switzerland (n=129). We also studied 4,234 control subjects from these countries and 1,492 control subjects originating from Benin, Cameroon, Ethiopia, Ecuador, and Turkey. Polymorphisms were analysed by melting curve analysis with fluorescence resonance energy transfer probes. The frequency of G62C did not differ between patients with acute or chronic pancreatitis, pancreatic adenocarcinoma and control individuals. The frequency of G62C varied in European populations from 0.4 to 3.8%, showing a northwest to southeast decline. The Y54H alteration was not detected in any of the 2,436 patients. Only 3/4,580 (0.07%) European, Turkish and Indian control subjects were heterozygous for Y54H in contrast to 34/951 (3.6%) control subjects of African descent. Our data suggest that the KRT8 alterations, Y54H and G62C, do not predispose patients to the development of pancreatitis or pancreatic cancer.

[Clinical aspects of retinopathy of prematurity. Results following diode laser coagulation]

Retinopathy of prematurity (ROP) represents a disease of the immature retina of preterm infants due to irregular vascularisation. The present article gives information about different parameters of the newborns (gestational age, birth weight, need of oxygen, stage of ROP) and shows the results concerning anatomical and functional aspects following diode laser treatment in 61 prematurely born babies, diagnosed and treated in a period of 5S years in the Hospital of the Ludwig Maximilians University. The mean +/- SD gestational age was 24.9 (+/- 1.59) weeks, the mean +/- SD birth weight was 683 (+/- 174) grams. Diode laser treatment was performed at a mean +/- SD age of 36.14 (+/- 2.04) weeks. Stage 3 retinopathy with "plus disease" was diagnosed in 95.5 % of the infants. In comparison to term born babies or preterm infants without ROP, the diode laser-treated newborns showed a higher incidence of myopia (59 %). An unfavourable outcome in term of the anatomic situation was seen in 9.8 % of these babies.

Laparoscopic fluorescence diagnosis for intraabdominal fluorescence targeting of peritoneal carcinosis experimental studies

OBJECTIVE

To assess 5-aminolevulinic acid (ALA)-induced protoporphyrin IX accumulation and fluorescence in peritoneal colon carcinoma metastases and its benefits for laparoscopic fluorescence diagnosis.

SUMMARY BACKGROUND DATA

Occult, macroscopically nonvisible peritoneal micrometastases can be missed in laparoscopy or open surgery. Laparoscopic fluorescence diagnosis allows detection of these lesions after intraperitoneal lavage with ALA and subsequent fluorescence induction by blue-light excitation.

METHODS

A disseminated peritoneal carcinosis was induced by laparoscopic implantation of colon carcinoma cells (CC531) in the peritoneum of 55 WAG/Rij rats. After 12 days of tumor growth the animals were randomized into 11 groups with different photosensitization parameters. Peritoneal lavage was performed either with 1.5% or 3.0% ALA solution, except for one control group. Photosensitization times were 0.5, 1, 2, 4, or 8 hours. Spectrometry was performed using an optical multichannel analyser. ALA and protoporphyrin IX serum levels were measured by high-performance liquid chromatography to determine systemic load.

RESULTS

Protoporphyrin IX tumor accumulation and fluorescence peaked 2 to 4 hours after ALA application in both main groups, 1.5% and 3.0% ALA. Tumor detection rate was most effective in the 1.5% ALA group. Compared with conventional white-light laparoscopy alone, blue-light excitation detected 35% additional intraabdominal tumor foci.

CONCLUSIONS

Laparoscopic fluorescence diagnosis can increase the sensitivity and specificity of diagnostic staging laparoscopy. It allows determination of the extent of peritoneal carcinosis. Improved preoperative assessment helps to avoid unnecessary laparotomies and radical resections.

Systemic vs local administration of delta-aminolevulinic acid for laparoscopic fluorescence diagnosis of malignant intra-abdominal tumors. Experimental study

BACKGROUND

Administration of delta-aminolevulinic acid (ALA) either systemically or locally results in tumor-specific accumulation of protoporphyrin IX (PpIX). When excited with light at a defined wavelength and viewed with the appropriate filter cells containing PpIX, have a characteristic red fluorescence. We evaluated both locally (intraperitoneally [i.p.]) and systemically (intravenously [i.v.]) administered ALA to compare its effectiveness for laparoscopic fluorescent visualization of intraperitoneal tumors.

METHODS

Peritoneal carcinosis was induced in rats using colon carcinoma cells (CC531). Photosensitization was achieved either by intravenous (i.v. group) or intraperitoneal (i.p. group) application of ALA solution. Staging laparoscopy was performed in both groups, first using conventional white light and subsequently using blue light (380-440 nm) to excite PpIX-induced fluorescence.

RESULTS

Conventional white light laparoscopy showed 142 visible intraperitoneal tumor foci in the i.p. group and 116 such foci in the i.v. group. In the i.p. group, all tumors (100%) also were fluorescence positive, whereas in the i.v. group only 32 of the tumors (28%) showed the typical red fluorescence. In the i.p. group, 30 additional tumors were detected by fluorescence excitation (21%), as compared with eight additional tumors in the i.v. group (7%).

CONCLUSIONS

Fluorescence laparoscopy after local (i.p.) photosensitization with ALA is a more reliable and effective method than systemic (i.v.) photosensitization for the detection of small or occult i.p. tumors.

Improving diagnostic staging laparoscopy using intraperitoneal lavage of delta-aminolevulinic acid (ALA) for laparoscopic fluorescence diagnosis

BACKGROUND

Lymph node metastases and peritoneal carcinosis, occurring as a result of gastrointestinal cancer, reduce the likelihood that conventional therapy will be adequate to remove the cancer. Although diagnostic techniques have greatly improved, it is not always possible to diagnose the entire extent of the metastases. Often, peritoneal micrometastases are not visible and may be missed during laparoscopic or open surgery.

METHODS

Peritoneal carcinosis was induced in WAG-Rij rats (n = 6), by laparoscopically implanting 1,2-dimethylhydrazine-induced colon carcinoma tumor cells (CC531, 5 x 10(5)) at multiple sites within the peritoneal cavity. After 12 days of tumor growth, the animals were given delta-aminolevulinic acid (ALA) (5 mL, 3% solution in 0.17 mol/L NaHCO3) by peritoneal lavage. The tumors were visualized laparoscopically using both white and blue light (D-light, Karl Storz, Tuttlingen, Germany). Fluorescence was detected by using a modified CCD camera and a special observation filter incorporated into the laparoscope.

RESULTS

Peritoneal carcinoma foci ranging in size from 0.05 to 2.0 cm were clearly visible laparoscopically with conventional white light (n = 142). After blue light excitation, all 142 tumors identified with white light were also identified by fluorescence. There were an additional 30 tumors that could only be identified by blue light-induced fluorescence and were histologically confirmed to be derived from colon carcinoma tumor cells.

CONCLUSIONS

Peritoneal colonic carcinoma foci were detected laparoscopically after intraperitoneal lavage with delta-aminolevulinic acid (ALA) and excitation with blue light. These experiments demonstrate that fluorescence laparoscopy is an important technique for the staging of gastrointestinal cancer, including colorectal cancer, because of the enhanced ability to detect small cancerous foci.

Spectrometry supports fluorescence staging laparoscopy after intraperitoneal aminolaevulinic acid lavage for gastrointestinal tumours

Conventional staging laparoscopy in combination with fluorescence diagnosis has proven to be an effective modality in the detection of macroscopically occult intraperitoneal tumours and metastases. Rats with induced peritoneal carcinosis are photosensibilized by intraperitoneal aminolaevulinic acid (ALA) lavage. After visualization of the tumour foci, the emission from the lesions is measured spectrometrically and the fluorescence analysed quantitatively ('optical biopsy'). There is a considerable accordance between imaging by fluorescence diagnosis laparoscopy and point spectrometry in the detection of peritoneal malignancies. Compared with surrounding healthy peritoneum, tumour-positive areas show significantly higher fluorescence intensities in spectrometry.

Flüchtige Inhaltsstoffe von Crotalaria ochroleuca und deren Wirkung auf Schadinsekten / Volatile Constituents from Crotalaria ochroleuca and Their Effect on Pest Insects

By means of GC -FTIR , GCMS and GC analysis more than 70 components of the steam distillate of seeds and leaves from Crotalaria ochroleuca (Fabaceae, Papilionaceae) were found and partially identified, most of them being aliphatic hydrocarbons, aldehydes and fatty acids. Weak, but significant repellency of the seeds, its steam distillate as well as of the seed oil com ponent 2-isopropyl-3-methoxypyrazine, 2-isobutyl-3-methoxypyrazine and 2-pentylfuran was observed with the curculionid beetle Sitophilus zeamays. Furthermore, no attractivity of fresh leaves was found for a number of test insects.

The Bereitschaftspotential in preparation to mental activities

Earlier studies had investigated the Bereitschaftspotential (Bp) under different aspects of muscular activities. The present experiments were designed to test whether the Bp will be affected by the degree of mental load while motor activity is kept constant. Fourteen healthy male subjects had to solve arithmetical tasks under a graduated time pressure (3 categories of tasks). The subjects had to indicate by pressing one of three keys (trigger), which category of task they wanted to solve next. As soon as a key had been pressed, a task appeared on the computer display and disappeared after the time interval corresponding to the selected category. The results had to be entered into a computer via a keyboard. The EEG signals (5 s time constant, 15 Hz upper frequency cut-off) were averaged time-locked to the movement onset, starting 1.5 s before the pressing of the key. Trials with artefacts were rejected from averaging. The Bp was found to be significantly higher when the tasks were to be solved under higher time pressure. We assume that this might be rather an expression of an appropriate self-activation for the expected mental task than due to a different motor preparation.

Oxygen binding properties, capillary densities and heart weights in high altitude camelids

The oxygen binding properties of the blood of the camelid species vicuna, llama, alpaca and dromedary camel were measured and evaluated with respect to interspecific differences. The highest blood oxygen affinity, not only among camelids but of all mammals investigated so far, was found in the vicuna (P50 = 17.6 Torr compared to 20.3-21.6 Torr in the other species). Low hematocrits (23-34%) and small red blood cells (21-30 microns 3) are common features of all camelids, but the lowest values are found in the Lama species. Capillary densities were determined in heart and soleus muscle of vicuna and llama. Again, the vicuna shows exceptional values (3720 cap/mm2 on average in the heart) for a mammal of this body size. Finally, heart weight as percent of body weight is higher in the vicuna (0.7-0.9%) than in the other camelids studied (0.5-0.7%). The possibility that these parameters, measured in New World tylopodes at sea level, are not likely to change considerably with transfer to high altitude, is discussed. In the vicuna, a unique combination of the following features seems to be responsible for an outstanding physical capability at high altitude: saturation of blood with oxygen in the lung is favored by a high blood oxygen affinity, oxygen supply being facilitated by low diffusion distances in the muscle tissue. Loading, as well as unloading, of oxygen is improved by a relatively high oxygen transfer conductance of the red blood cells, which is due to their small size and which compensates the negative effect of a low hematocrit on the oxygen conductance of blood.(ABSTRACT TRUNCATED AT 250 WORDS)

P300 and anticipated task difficulty

Recently, it has been shown that P300 measures depend on stimulus evaluation processes. This paper explores the effect of messages informing about the degree of difficulty of subsequent tasks on the P300 component. Ten healthy volunteers were asked to solve mental arithmetic tasks of graduated difficulty. The degree of difficulty was announced by messages which preceded the tasks and which were used as P300 eliciting stimuli. Measurements of the amplitude and latency of P300 components from 3 brain regions (Fz, Cz, Pz) were collected selectively for each category of task difficulty announced. Subjective ratings of difficulty and the frequency of errors confirmed the monotonic increase of task difficulty from categories I to VI. The mean P300 amplitude in categories I-VI showed a U-shaped trend, i.e. the highest amplitude occurred in the extreme categories 'extremely easy' and 'very difficult'. No significant effect of stimulus categories on P300 peak latencies was found. It is concluded that the P300 amplitude reflects an evaluation in the sense of distance judgements on an internal scale which in this study concerned the task difficulty.

Cellular hyperplasia and hypertrophy, capillary proliferation and myoglobin concentration in the heart of newborn and adult rats at high altitude

Newborn rats and their mothers were subjected to a simulated altitude of 5000 m for 4-5 weeks. Weight, capillary density (CD), fiber cross-sectional area (AF) and capillary-to-fiber ratio (C/F) of right (RV) and left (LV) ventricles and myocardial myoglobin (Mb) concentration were measured weekly in the newborns and at the end of the high altitude sojourn in the adults. Results were compared to sea level controls. In the adults, adaptive changes were only observed in the right ventricle. In newborns both, RV and LV, exhibited significant alterations. After 2 weeks at 5000 m the ventricular weight increase was 223% (RV) and 40% (LV) in the newborns and 96% in the adults' RV. Whereas only fiber hypertrophy was detectable in the RV of the dams, cardiac weight increase of the acclimatized neonates resulted from both, hypertrophy and hyperplasia of the myocytes. Appropriate capillary proliferation kept CD constant. Cardiac Mb concentration did not change. We conclude, that capillary neoformation primarily counteracts the increase of the O2 diffusion distance due to fiber hypertrophy and/or hyperplasia.

Hemispheric differences in VEP elicited by mental arithmetic and tachistoscopically presented spatial transformation tasks

Recent studies have furnished evidence of hemispheric asymmetry in the EEG and event-related potentials in man. Face-validated tasks as verbal and nonverbal ones (A: mental arithmetic; B: detection of a target in the hand of a manikin in different positions) were tachistoscopically presented to check side differences of VEP parameters in 5 healthy right-handed subjects. The EEG was recorded from C3, C4, P3 and P4 referenced to linked ears. The mean peak latencies of averaged VEPs were P1: 107 ms, N1: 142 ms, P2: 203 ms, N2: 265 ms, P3: 357 ms. No consistent treatment effects were obtained for peak latencies. Regardless of side differences, the attention related VEP amplitudes P1-N1 and N1-P2 were higher in A. Rightleft differences were found to be higher for visual-spatial transformation, except P2-N2 amplitude. The asymmetry of amplitudes suggests a higher activity of the right hemisphere in B. A possible description of dynamic variations due to learning and changes of strategy during repetitive mental activity by means of changes in EP asymmetry will be of interest for further investigations.

Capillary supply of heart and skeletal muscle of small bats and non-flying mammals

Capillary density (CD), fiber cross-section area, capillary-to-fiber ratio and intercapillary distance of papillary and a calf muscle were evaluated in four species of bats (body weight 23-150 g) and six non-flying mammalian species (2.5-170 g). In bats the pectoralis muscle was studied additionally. In both groups CD increased in papillary as well as in calf muscle with decreasing body weight. The papillary muscles showed the highest CD in the 2.5 g shrew Suncus etruscus (7287 cap./mm2) and the 23 g bat Myotis myotis (6748 cap./mm2). The flight muscle of the 38 g bat Molossus ater showed the highest CD (4992 cap./mm2) of all skeletal muscles investigated. The slopes of regressions of CD versus body weight for papillary (calf) muscles were -0.42 (-0.70) for bats and -0.15 (-0.26) for non-flying mammals, indicating that bats have a higher increase of weight-specific metabolic rate with decreasing body weight. This holds for species with a body weight below 30 g.

[Activation-dependent characteristics of the electroencephalogram during visual information processing: II Results of an automatic amplitude analysis based on momentary values of signal voltage (author's transl)]

EEG was recorded in 16 Ss. under conditions of a modified "Konzentrations-Leistung-Test" including four levels of performance (balanced change-over design), and histograms of the momentary values of the signal voltages (derivation F3/01) constructed for frequency bands 4...8 Hz, 8...13 Hz and 13...26 Hz. The type of performance affected significantly standard deviations and the excesses in all frequency bands (multivariate analysis of variance, F-Test). Similar to the results of an interval analysis (Activ. ner. sup. 18, 1976, p. 244), the differences in mean values indicated the preponderant relevance of perceptual factors (NEWMAN-KEULS-Test). Four characteristics showed a significant activation dependence: the standard deviations of the amplitude distributions in the frequency bands 4...8 Hz and 13...26 Hz, corresponding to the root-mean--square values of the signal voltages, as well as the excesses in the frequency bands 8...13 Hz and 13...26 Hz. Only and amplitude of the theta waves were influenced notably by mental arithmetics, significantly though only when this was done under conditions of time stress.