Recombinant inbred line differential identifies race-specific resistance to phytophthora root rot in Capsicum annuum

A differential series is the normal method for identification of races within a plant pathogen and a host interaction. A host differential is extremely useful for phytopathological as well as breeding purposes. A set of recombinant inbred lines (RILs) were developed and characterized for race differentiation of Phytophthora root rot caused by Phytophthora capsici. The highly resistant Capsicum annuum accession Criollo de Morelos-334 was hybridized to a susceptible cultivar, Early Jalapeno, to generate the RIL population. The host differential characterized 17 isolates of P. capsici into 13 races. The establishment of a stable host differential for the P. capsici and C. annuum interaction will assist researchers in understanding the complex inheritance of resistance to Phytophthora root rot and to develop resistant cultivars.

[Seven years of botulinum toxin type A in the treatment of neurogenic detrusor hyperactivity]

BACKGROUND

A decompensated storage function with high pressures is the greatest risk factor regarding life expectancy and quality of life in patients with neurogenic detrusor hyperactivity. Previously, this problem could only be managed with administration of anticholinergic medications or--if this approach was either not effective enough or the patients exhibited drug intolerance--by invasive surgical interventions. The use of botulinum toxin type A to treat these patients rapidly proved to be a beneficial alternative to those two therapeutic options ever since its introduction in Germany in 1998 as a minimally invasive procedure and has become established worldwide.

MATERIAL AND METHODS

The medical records of first-time users at the clinic were retrospectively analyzed for a 7-year period. The total of 492 injections in 277 patients--of which 365 injections in 216 patients were performed following a standardized protocol--represents the largest number of cases worldwide. The treatment was indicated in patients experiencing insufficient efficacy of anticholinergic agents or drug intolerance who were capable of self-catheterization.

RESULTS

The standard injection contained either 300 MU Botox or 750 MU Dysport. Urodynamic parameters before and up to 8 months post-intervention showed significantly lowered detrusor pressure and improved cystometric capacity. This corresponded to the clinical assessment and subjective impression of the patients that detrusor activity had been reduced to a large extent with improved continence. Evacuation was carried out in all cases without any difficulty by aseptic intermittent catheterization. The average duration of the effect was subjectively determined to be 8.7 months. In the vast majority of cases, anticholinergic medications could be discontinued or considerably reduced. Side effects not requiring treatment developed in only four instances. Antibody formation no longer occurred with those products available on the market since 2001. Even after repeated injections (up to ten times) there was no evidence for decreased efficacy.

CONCLUSION

Due to its reliable effect and low rate of side effects, botulinum toxin type A quickly became accepted worldwide for the treatment of neurogenic detrusor hyperactivity and has contributed to a substantial enrichment of the more conservative therapy options. Prospective studies focusing especially on injection site and optimizing the duration of efficacy are desirable.

In vivo results for interstitial laser application in thyroid gland

OBJECTIVE

Aim of this study was to evaluate the potential of denaturation of hormone active tissue in the thyroid gland by laser induced interstitial thermotherapy (LITT) as a treatment of autonomous hyperthyroidism.

MATERIALS AND METHODS

An interstitial thyroid laser application (Nd:YAG 1064 nm, 5W, 2 min) was performed in 5 pigs. During laser application, the laryngeal recurrent nerve was controlled electro-physiologically. Postoperatively, TSH, total T(3) (TT(3)) and free T(4) (FT(4)) were measured regularly. After a follow-up period of up to 6 weeks, pigs were sacrificed and the thyroid glands were evaluated histological.

RESULTS

A malfunction of the nerve due to laser treatment was not detected. During the first postoperative week there was a decrease of both FT(4) and TSH whereas TT(3) showed an extreme decline of its plasma levels reaching nearly the detection limit. All values showed a recovery to their initial levels during an interval of 10 days and than increased to levels sometimes higher than baseline. The coagulation zones were demarcated clearly towards normal tissue with increasing fibrosis of the treated areas.

CONCLUSION

Interstitial thyroid ablation using a Nd:YAG laser is a minimal invasive, safe and effective procedure. Further evaluation including long term follow-up in humans is needed to confirm these results.

Evaluation of carotid artery stenosis with multisection CT and MR imaging: influence of imaging modality and postprocessing

BACKGROUND AND PURPOSE

We prospectively evaluated the influence of different imaging techniques (time-of-flight MR angiography [TOF-MRA], contrast-enhanced MR angiography [CE-MRA], multisection CT angiography [CTA]) and postprocessing methods (maximum intensity projection [MIP], multiplanar reformation [MPR]) on carotid artery stenosis grading.

MATERIALS AND METHODS

Fifty patients (34 men, 16 women) with symptomatic stenosis of the internal carotid artery were examined with a 16-section spiral CT and a 1.5T MR unit. Two MRA techniques were applied: 3D-TOF and CE-MRA. MPR was used for postprocessing with all modalities; MIP was used only with MRA. Four readers measured and calculated the percentage diameter stenosis independently according to NASCET criteria. The Wilcoxon test was used to measure interobserver variability, and the Friedman test was used to test the null-hypothesis of equality of the modalities.

RESULTS

The hypothesis for global equality was rejected (P < .001). TOF-MRA and CTA assessed with MPR showed the highest concordance (difference, 0.6%; confidence interval [CI], -3.0, 4.3%), and CE-MRA with MIP and CTA showed the lowest concordance in stenosis grading (difference, 7.0%; CI, 3.4, 10.6%). MPR resulted in lower degrees of stenosis than MIP for both MRA sequences, although not statistically significant (CE, -3.0%; CI, -6.6, 0.6%; TOF, -2.2%; CI, -5.8, 1.4%). When only studies with good or excellent image quality were considered, the differences decreased, but the trends remained.

CONCLUSION

Stenosis grading is dependent on the examination method and postprocessing technique. CTA and TOF-MRA evaluated with MPR revealed highest concordance.

SLIM: A new method for molecular imaging

We used spectrally resolved fluorescence lifetime imaging (SLIM) to investigate the mitochondria staining dye rhodamine 123 and binding of DAPI to RNA and DNA in cells. Moreover, different components of the photosensitizer Photofrin were resolved in cell cultures by SLIM. To record lifetime images (tau-mapping) with spectral resolution we used a laser scanning microscope equipped with a spectrograph, a 16 channel multianode PMT, and multidimensional time-correlated single photon counting. A Ti:Saphir laser was used for excitation or alternatively a ps diode laser. With this system the time- and spectral-resolved fluorescence characteristics of different fluorophores were investigated in cell cultures. As an example, the mitochondria staining dye rhodamine I23 could be easily distinguished from DAPI, which binds to nucleic acids. Also different binding sites of DAPI could be discriminated. This was proved by the appearance of different lifetime components within different spectral channels. Moreover, we were able to detect monomeric and aggregated forms of Photofrin in cells. Different lifetimes could be attributed to the various compounds. In addition, a detailed analysis of the autofluorescence by SLIM could explain changes of mitochondrial metabolism during Photofrin-PDT.

Gene expression in skeletal muscle of coronary artery disease patients after concentric and eccentric endurance training

Low-intensity concentric (CET) and eccentric (EET) endurance-type training induce specific structural adaptations in skeletal muscle. We evaluated to which extent steady-state adaptations in transcript levels are involved in the compensatory alterations of muscle mitochondria and myofibrils with CET versus EET at a matched metabolic exercise intensity of medicated, stable coronary patients (CAD). Biopsies were obtained from vastus lateralis muscle before and after 8 weeks of CET (n=6) or EET (n=6). Transcript levels for factors involved in mitochondrial biogenesis (PGC-1alpha, Tfam), mitochondrial function (COX-1, COX-4), control of contractile phenotype (MyHC I, IIa, IIx) as well as mechanical stress marker (IGF-I) were quantified using an reverse-transcriptase polymerase chain reaction approach. After 8 weeks of EET, a reduction of the COX-4 mRNA level by 41% and a tendency for a drop in Tfam transcript concentration (-33%, P=0.06) was noted. This down-regulation corresponded to a drop in total mitochondrial volume density. MyHC-IIa transcript levels were specifically decreased after EET, and MyHC-I mRNA showed a trend towards a reduction (P=0.08). Total fiber cross-sectional area was not altered. After CET and EET, the IGF-I mRNA level was significantly increased. The PGC-1alpha significantly correlated with Tfam, and both PGC-1alpha and Tfam significantly correlated with COX-1 and COX-4 mRNAs. Post-hoc analysis identified significant interactions between the concurrent medication and muscular transcript levels as well as fiber size. Our findings support the concept that specific transcriptional adaptations mediate the divergent mitochondrial response of muscle cells to endurance training under different load condition and indicate a mismatch of processes related to muscle hypertrophy in medicated CAD patients.

[Practice guidelines: conservative treatment of fibroids]

The conservative treatment of uterine fibroids is essentially based on symptomatology and patient's choice of treatment. The gynaecologist must develop a clear therapeutic protocol based on clinical examination, available test results and consideration of patient preference. The therapeutic options include close surveillance, hormonal treatments, conservative operative endoscopy and arterial embolization.

Eccentric endurance training in subjects with coronary artery disease: a novel exercise paradigm in cardiac rehabilitation?

This study evaluated the effects of 8 weeks of eccentric endurance training (EET) in male subjects (age range 42-66 years) with coronary artery disease (CAD). EET was compared to concentric endurance training (CET) carried out at the same metabolic exercise intensity, three times per week for half an hour. CET ( n=6) was done on a conventional cycle ergometer and EET ( n=6) on a custom-built motor-driven ergometer. During the first 5 weeks of the training program the metabolic load was progressively increased to 60% of peak oxygen uptake in both groups. At this metabolic load, mechanical work rate achieved was 97 (8) W [mean (SE)] for CET and 338 (34) W for EET, respectively. Leg muscle mass was determined by dual-energy X-ray absorptiometry, quadriceps strength with an isokinetic dynamometer and muscle fibre composition of the vastus lateralis muscle with morphometry. The leg muscle mass increased significantly in both groups by some 3%. Strength parameters of knee extensors improved in EET only. Significant changes of +11 (4.9)%, +15 (3.2)% and +9 (2.5)% were reached for peak isometric torque and peak concentric torques at 60 degrees s(-1) and 120 degrees s(-1), respectively. Fibre size increased significantly by 19% in CET only. In conclusion, the present investigation showed that EET is feasible in middle-aged CAD patients and has functional advantages over CET by increasing muscle strength. Muscle mass increased similarly in both groups whereas muscle structural composition was differently affected by the respective training protocols. Potential limitations of this study are the cautiously chosen conditioning protocol and the restricted number of subjects.

Real-time augmentation of USDA yield grade application to beef carcasses using video image analysis

In two phases, this study assessed the ability of two video image analysis (VIA) instruments, VIASCAN and Computer Vision System (CVS), to augment assignment of yield grades (YG) to beef carcasses to 0.1 of a YG at commercial packing plant speeds and to test cutout prediction accuracy of a YG augmentation system that used a prototype augmentation touchpanel grading display (designed to operate commercially in real-time). In Phase I, beef carcasses (n = 505) were circulated twice at commercial chain speeds (340 carcasses per hour) by 12 on-line USDA graders. During the first pass, on-line graders assigned a whole-number YG and a quality grade (QG) to carcasses as they would normally. During the second pass, on-line graders assigned only adjusted preliminary yield grades (APYG) and QG to carcasses, whereas the two VIA instruments measured the longissimus muscle area (LMA) of each carcass. Kidney, pelvic, and heart fat (KPH) was removed and weighed to allow computation of actual KPH percentage. Those traits were compared to the expert YG and expert YG factors. On-line USDA graders' APYG were closely related (r = 0.83) to expert APYG. Instrument-measured LMA were closely related (r = 0.88 and 0.94; mean absolute error = 0.3 and 0.2 YG units, for VIASCAN and CVS, respectively) to expert LMA. When YG were augmented using instrument-measured LMA and computed either including or neglecting actual KPH percentage, YG were closely related (r = 0.93 and 0.92, mean absolute error = 0.32 and 0.40 YG units, respectively, using VIASCAN-measured LMA; r = 0.95 and 0.94, mean absolute error = 0.24 and 0.34 YG units, respectively, using CVS-measured LMA) to expert YG. In Phase II, augmented YG were assigned (0.1 of a YG) to beef carcasses (n = 290) at commercial chain speeds using VIASCAN and CVS to determine LMA, whereas APYG and QG were determined by online graders via a touch-panel display. On-line grader YG (whole-number), expert grader YG (to the nearest 0.1 of a YG), and VIASCAN- and CVS-augmented YG (to the nearest 0.1 of a YG) accounted for 55, 71, 60, and 63% of the variation in fabricated yields of closely trimmed subprimals, respectively, suggesting that VIA systems can operate at current plant speeds and effectively augment official USDA application of YG to beef carcasses.

Accuracy and repeatability of beef carcass longissimus muscle area measurements

This study was conducted to determine the accuracy and repeatability of beef carcass longissimus muscle area (LMA) measurements obtained by three different methods. Longissimus muscle area for beef carcass sides (n = 100) randomly selected in a commercial packing plant was determined: 1) independently by three USDA grading supervisor "experts" using the grid method to obtain triplicate measurements of the same longissimus muscle (LM); 2) by three different Colorado State University personnel tracing the LMA on acetate paper and subsequently measuring the area via a polar planimeter three different times (total of 3 x 3 = 9 observations/LM); and 3) by use of two identical video image analysis (VIA) instruments making triplicate measurements for each LM using three different procedures. Video image analysis Procedure 1 required that LMA be measured by placing the camera head unit over the LM and collecting three sequential images without moving the camera head unit while carcasses were in a stationary position; Procedure 2 required measurement of LMA by placing the camera head unit over the LM and collecting three images, but removing and repositioning the camera head unit between collection of each image while carcasses were in a stationary position; and Procedure 3 required that LMA be measured by placing the camera head unit over the LM and obtaining an image while carcasses were in continuous motion (chain speed of 360 carcasses/ h) during three different circulations past the grading stand. Overall, VIA-derived LMA measurements were highly accurate for all three procedures compared with expert-gridded (R2 = 0.92, 0.90, and 0.84 for Procedures 1, 2, and 3, respectively) and acetate/planimeter-traced (R2 = 0.94, 0.93, and 0.86 for Procedures 1, 2, and 3, respectively) LMA measurements. Instrument LMA repeatability also was comparable to expert-gridded and acetate/planimeter-traced LMA repeatability, as the means of the absolute differences between individual measurements and the average of those same measurements per LM were 1.29, 1.35, 0.52, 0.84, and 1.87 cm2 for expert-gridded, acetate/planimeter-traced, and VIA Procedures 1, 2, and 3, respectively. Therefore, VIA instrumentation can be used to assess beef carcass LMA in both a stationary and operational scenario with high levels of accuracy and repeatability.

[The cannulated osteo-support rod, a new device for the minimally invasive reduction of fractures]

We report a newly developed device for fracture reduction and the positioning of K-wires, especially the guide wires of cannulated screws. It is designed as a cannulated ball spike pusher whose tip and inlay consists of a K-wire fixed in the lumina of the device by a screw. Thus, in displaced fractures, the (guide) wire can be inserted into the bone from the point of reduction, simplifying the intra-operative technique especially in minimally invasive procedures. Additionally, severely displaced fracture fragments can be handled quite comfortably percutaneously by using this device with a "joy stick" technique. The first practical experience in cannulated screw and K-wire osteosyntheses using this device are reported here.

Variable-angle total internal reflection fluorescence microscopy (VA-TIRFM): realization and application of a compact illumination device

A novel compact illumination device in variable-angle total internal reflection fluorescence microscopy (VA-TIRFM) is described. This device replaces the standard condensor of an upright microscope. Light from different laser sources is delivered via a monomode fibre and focused onto identical parts of a sample under variable angles of total internal reflection. Thus, fluorophores in close proximity to a cell-substrate interface are excited by an evanescent wave with variable penetration depth, and localized with high (nanometre) axial resolution. In addition to quantitative measurements in solution, fluorescence markers of the cytoplasm and the plasma membrane, i.e. calcein and laurdan, were examined using cultivated endothelial cells. Distances between the glass substrate and the plasma membrane were determined using the mathematical algorithm of a four-layer model, as well as a Gaussian-shaped intensity profile of the illumination spot on the samples. Distances between 0 and 30 nm in focal contacts and between 100 and 300 nm in other parts of the cell were thus determined. In addition to measurements of cell-substrate topology, the illumination device appears appropriate for numerous applications in which high axial resolution is required, e.g. experiments on endocytosis or exocytosis, as well as measurements of ion concentrations proximal to the plasma membrane. The compact illumination device is also suitable for combining TIRFM with further innovative techniques, e.g. time-resolved fluorescence spectroscopy, fluorescence lifetime imaging (FLIM) or fluorescence resonance energy transfer (FRET).

[Eccentric muscle work--the unknown side of our movements]

Eccentric muscle work is an important part of our everyday activity, i.e. in breaking and preventing falls. Eccentric phases of movements improve the efficiency of cyclic repetitive activities. The molecular function in eccentric work is not understood, however its characteristics are a low metabolic demand and a high power output. Compared to concentric work there are only small differences in the hemodynamics of eccentric work. The muscle capacity for mechanical load is the limiting factor in eccentric work. Unaccustomed eccentric activity leads to damage of the cytoskeleton, which is the reason for delayed onset of muscle soreness. In sports and rehabilitation eccentric training can result in significant strength gain. Its use is today established to improve structures, which are exposed to eccentric loads in everyday activity. The high mechanical power may be promising in the musculoskeletal rehabilitation of patients with cardiopulmonary limitations.

[Intracanalicular trabeculostomy with the Er:YAG laser]

PURPOSE

To develop a new ab externo technique for glaucoma trabecular surgery using the infrared Er:YAG laser radiation (2.9 micrometer) guided into Schlemm's canal by an optical fiber.

MATERIAL AND METHODS

In order to create a drainage canal to the anterior chamber, a quartz fiber (core diameter: 100 micrometer) coupled to an Er:YAG laser was shielded by a metal canula (diameter: 280 micrometer) bent in conformance to the curvature of Schlemm's canal. A 45 degrees -mirror enabled the laser radiation to exit the canula perpendicular to the fiber axis. The complete surgery device was tested on agar medium and enucleated human eyes.

RESULTS

Using the unshielded quartz fiber, eight pulses of 8 mJ (frequency: 7 Hz, pulse duration: 150 microseconds) were sufficient to perforate the trabecular meshwork of the human eye. Histology showed a rippled canal with 50 micrometer average diameter and a surrounding necrosis zone of 15-35 micrometer. The complete device could be easily inserted into Schlemm's canal similar to the classic trabeculostomy probe and a conical-shaped canal with a length of 2-3 mm could be created in agar medium within a few seconds.

CONCLUSIONS

Initial experience in an experimental set-up show the ab externo creation of a draining canal between Schlemm's canal and the anterior chamber with only minimal irritation of the surrounding tissue. Further refinements of the laser parameters and the biomechanical set-up resulted in a new hand-held device with improved function. The Er:YAG laser intracanalicular trabeculostomy could become a new ab externo technique for minimal invasive therapy of open angle glaucoma.

Feto-maternal interface of human placenta inhibits angiogenesis in the chick chorioallantoic membrane (CAM) assay

The rapidly growing chorionic villi of the human placenta characteristically show constant blood vessel growth and differentiation. In contrast, the underlying decidua reveals tissue remodeling without apparent angiogenesis. Using the chick chorioallantoic membrane (CAM) assay, we found marked inhibition of angiogenesis by the feto-maternal interface tissue derived from nine human placentas obtained minutes after delivery. Inhibition was prevented by the addition of monensin, which blocks the release of synthesized cell products, and was markedly reduced by drying or freezing the tissue before the assay. Histology, combined with statistical analysis of the constituent cell types, correlated inhibition of angiogenesis with the number of fetally-derived extravillous trophoblasts in the feto-maternal interface tissue. Electron microscopy revealed endothelial cell damage in preexisting small (but not large) CAM vessels. We conclude that decidual tissue inhibited angiogenesis by releasing a water soluble factor which was under apparent constant production by vaible trophoblast on the CAM. The extravillous trophoblast population resembles tumor cells in its migratory and invasive properties but, in contrast to tumor induced angiogenesis, it is angiostatic, perhaps to counteract angiogenic proteins leaking from the intervillous space which could be detrimental to the maternal organism if active.

["It is a new kind of diaspora ..." Some notes on the politics of psychanalysts emigration, according to E. Jones's correspondence with Anna Freud]

This paper is an attempt to describe the forced emigration of the Jewish and non Jewish German and Austrian psychoanalysts, to Great Britain and to America and other countries, during the nazi persecution started in Germany in 1933. The paper is mainly based on the unpublished correspondence between A. Freud and E. Jones and other documents. The paper deals with the two major waves of forced emigration from Berlin in 1933-1934 and from Vienna in 1938 and illustrates E. Jones's and A. Freud's attempts to organize and direct the emigration and all the problems, difficulties and political decisions connected with it. There were objective difficulties due to the economical and social situation of Great Britain and America at that time. Yet there were also the difficulties related to the internal conflicts of schools and personalities of the various national Societies belonging to the International Psychoanalytical Association chaired by Jones. Using some details of the correspondence, the paper tries to show the differences in tactics to deal with very delicate and complex issues, adopted by E. Jones and A. Freud at times, especially for what concerned the attempt to save psychoanalysis as an Institution in Germany. To illustrate the difficulties related to the acceptance of some psychoanalysts coming from Berlin or from Vienna, the paper focuses on W. Reich's episode as it was dealt with in the correspondence between A. Freud and E. Jones, and finally on the problems created in the British Psychoanalytical Society, by the emigration of S. Freud and his daughter to Great Britain.

Model of interstitial pressure as a result of cyclical changes in the capillary wall fluid transport

Reported interstitial pressures range from -8 to +6 mm Hg in different tissues and from <-20 mm Hg in burned tissue or more than +30 mm Hg in tumors. We have tried to link interstitial pressure to the here proposed cyclical changes in the fluid transport across the capillary wall. In the presented model interstitial pressure is considered as an average of pressures in numerous pericapillary spaces. A single pericapillary pressure is a dynamic difference between the net outward (hydraulic pressure+interstitial colloid osmotic pressure) and inward (plasma colloid oncotic pressure) forces. Hence, dominating net outward forces would result in a positive pericapillary interstitial pressure, while stronger inward forces would produce negative pressures in the pericapillary space. All interruptions of blood flow leave some blood in capillaries with a normal oncotic pressure and no hydrostatic pressure that might act as a strong absorber of interstitial fluid until the blood flow is reestablished. Model assumptions for the systemic circulation capillaries include (a) precapillary sphincters can almost entirely stop the capillary flow, (b) only a minority of sphincters are normally open in the tissue, and (c) hydrostatic pressures in unperfused capillaries are similar to the pressures at their venous ends. The key proposal is that capillaries with closed precapillary sphincters along their entire length have low hydrostatic pressure of 10 to 15 mm Hg. This pressure cannot force filtration, so these capillaries reabsorb interstitial fluid from the pericapillary space along their entire length. In the open capillaries, hydrostatic pressure filtrates fluid to the pericapillary space along most of their length. Fluid enters, moves some 20 or 30 micrometers away and back to be reabsorbed at the same point. Closed periods are periods of intense fluid reabsorption, while the short open periods refill the space with fresh fluid. It can be calculated that subcutaneous tissue interstitial pressure values might develop if the closed periods are 1.14 to 2.66 times longer than the open periods. Positive interstitial pressures observed in some organs might develop if open periods are longer than the closed periods. High interstitial colloid pressure in lungs makes both perfused and unperfused capillaries absorptive, resulting in more negative values of lung interstitial pressure. The same model is used to explain interstitial pressure values in tumors, burned tissue and intestinal villi.

Measuring comfort in caregivers and patients during late end-of-life care

The purpose of this study was to test several formats of end-of-life comfort instruments for patients and closely involved caregivers. Kolcaba's Comfort Theory was the theoretical framework utilized. Different response formats for two end-of-life (EOL) comfort questionnaires (for patients and caregivers, respectively), and horizontal and vertical visual analog scales for total comfort (TC) lines were compared in two phases. Evaluable data were collected from both members of 38 patient-caregiver dyads in each phase. Suitable dyads were recruited from two hospice agencies in northeastern Ohio. Cronbach's alpha for the EOL comfort questionnaire (six response Likert-type format) tested during phase I for patients was .98 and for caregivers was .97. Test-retest reliability for the vertical TC line tested during phase I for patients was .64 and for caregivers was .79. The implications of this study for nursing practice and research are derived from the American Nursing Association (ANA) position statement about EOL care, which states that comfort is the goal of nursing for this population. These instruments will be useful for assessing comfort in actively dying patients and comfort of their caregivers as well as for developing evidence-based practice for this population.

Increased blood levels of human S100 in melanoma chick embryo xenografts' circulation

The chorioallantoic membrane (CAM) of the fertilized egg allows grafting of human melanomas for short-term investigations and offers the opportunity to investigate the behavior of metastasizing cells and the release of S100beta into peripheral blood. Tissue from one primary melanoma as well as cutaneous and subcutaneous metastases of 10 melanoma patients with elevated levels of S100 in the peripheral blood before surgery were transplanted onto the CAM of chick embryos at day 5/6 of development. Grafts were nourished by the host blood supply 2 days after transplantation. Histologically, 3 days after grafting, metastasizing melanoma cells could be found near the vessels of the host membrane, penetrating the endothelial layer and entering the blood system. Growth conditions remained stable for 6 days after transplantation. Blood samples were taken from a larger CAM vessel before collecting the xenografts 5 days after grafting. Measurement of human S100 in peripheral blood was performed in a blinded manner. No negative control showed elevated levels of human S100 protein. Samples deriving from melanoma xenografts contained highly elevated levels of S100 protein in 80% of cases. The data strongly support the concept of graft-host interaction concerning adherence of tumors and extravasation of human melanoma cells.

Fluorescence detection of small gastrointestinal tumours: principles, technique, first clinical experience

Photodynamic therapy (PDT) is a form of cancer treatment based on the selective accumulation of a photosensitizer in neoplastic tissue. The fluorescent properties of a photosensitizer permit diagnostic localization of primary tumours and/or metastasis. Occult lesions are hard to detect and can easily be missed during routine laparoscopy. Fluorescence observation offers additional optical information and the ability to detect these occult tumours. Clinically, we used 5-aminolevulinic acid for peritoneal staining and tumour demarcation via tumour-specific fluorescence induced by protoporphyrin IX. For laparoscopic observations, a "D-Light" system was used; the conventional white light source was equipped with an optical blocking filter that transmits at the excitation wavelength (380-450 nm) and blocks all other parts of the spectrum. With the aid of a suitable observation filter, the relevant fluorescence was detectable. With the help of this fluorescence we increased the capacity to detect occult tumours, that were missed with white-light observation (9/26). In the gastrointestinal tract, we used a krypton laser at 405 nm for PP IX fluorescence induction. Although there were high sensitivity rates for neoplasms (81% peritoneal carcinomas, 60% gastric cancer), no exact histopathological statement could be achieved at because of false-positive fluorescence, mainly caused by inflammation (6/32). Current clinical goals and the future perspectives of photodynamic diagnostic are discussed.

Inhibition of tumor angiogenesis by a single-chain antibody directed against vascular endothelial growth factor

Monoclonal antibody (Ab) directed against the vascular endothelial growth factor, one of the major inducers of angiogenesis, can inhibit tumor growth in mice. Treatment of cancer patients with monoclonal Ab requires large-scale production of the clean Ab and frequent application of the Ab. This might be improved by using single-chain Ab fragments (scFvs), which can be produced in large quantities in bacteria and are attractive for gene therapeutic approaches. Here we describe anti-vascular endothelial growth factor scFvs derived from a human phage-display library able to block the vascularization of the chorioallantoic membrane of chick embryos and reduce the growth of s.c. tumors in nude mice. This work opens the way to develop gene therapy-based strategies using a scFv to treat angiogenesis-dependent diseases.

Thermo-controlled device for inducing deep coagulation in the liver with the Nd:YAG laser

BACKGROUND AND OBJECTIVE

To increase the effectiveness of laser-induced interstitial thermotherapy (LITT), a new thermo-controlled application system for minimal invasive intervention was designed. Our system consists of a laser applicator of 2.5 mm in diameter, insertion equipment, and a Nd:YAG-laser source.

STUDY DESIGN/MATERIALS AND METHODS

A cylindrical light emitting fiber (1-6 cm in length) was placed in the center of the applicator. The surrounding tissue was irradiated through a Duran window at the distal end of the applicator. The power of the laser source was controlled dynamically by thermosensors in a water-cooling system of the laser applicator. The temperature at the surface of the Duran window was kept constant at approximately 60 degrees C, without charring the surrounding tissue.

RESULTS/CONCLUSION

We obtained homogeneous coagulation zones. In in vitro experiments with pig livers, we reached ellipsoid coagulation volumes of 3 and 5 cm in diameter within 10 minutes, corresponding to a volume of approximately 25 cm3.

Corneal Morphology in vitro After Superficial Keratectomy With Q-switched Er:YSGG and Free-running Er:YAG Lasers

PURPOSE

Examination of morphology in corneal ablation induced by a q-switched Er:YSGG (2.79 microm) laser and a free-running Er:YAG laser (2.94 microm).

METHODS

Defined ablation of 6-mm diameter and 15, 30, 55, 90, and 120-microm depth was performed on freshly enucleated swine eyes. Er:YSGG laser parameters: fluence 1.6 J/cm2, frequency 6 Hz, spot-size 465 microm FWHM, scanning-mode, pulse number 1520 to 6210. Er:YAG laser parameters: fluence 3 J/cm2, frequency 1.5 Hz, spotsize 6 mm, wide area ablation, pulse number 2 to 13. Corneal morphology was analyzed by gross photography, histology, scanning electron microscopy, and scanning nearfield acoustic microscopy.

RESULTS

Histology showed thermal damage of 5 to 15 microm in depth caused by the Er:YSGG laser in comparison with 10 to 20 microm by the Er:YAG laser. Average roughness of the ablated surface measured with scanning nearfield acoustic microscopy was 20 to 40 microm for the Er:YSGG laser and 5 to 15 microm for the Er:YAG laser. These data confirm the subjective impression of images created by scanning electron microscopy and gross photography.

CONCLUSIONS

Although the Er:YAG laser system appeared to demonstrate a smoother corneal surface than the q-switched Er:YSGG laser, the thermal damage in either case poses a potential limitation for clinical use in lamellar refractive surgery.