Goats show higher behavioural flexibility than sheep in a spatial detour task.

The ability to adapt to changing environments is crucial for survival and has evolved based on socio-ecological factors. Goats and sheep are closely related, with similar social structures, body sizes and domestication levels, but different feeding ecologies, i.e. goats are browsers and sheep are grazers. We investigated whether goats' reliance on more patchily distributed food sources predicted an increased behavioural flexibility compared to sheep. We tested 21 goats and 28 sheep in a spatial A-not-B detour task. Subjects had to navigate around a straight barrier through a gap at its edge. After one, two, three or four of these initial A trials, the gap was moved to the opposite end and subjects performed four B trials. Behaviourally more flexible individuals should move through the new gap faster, while those less behaviourally flexible should show greater perseveration. While both species showed an accuracy reduction following the change of the gap position, goats recovered from this perseveration error from the second B trial onwards, whereas sheep did so only in the fourth B trial, indicating differences in behavioural flexibility between the species. This higher degree of flexibility in goats compared to sheep could be linked to differences in their foraging strategies.

OSIRIS-REx Contamination Control Strategy and Implementation.

OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and <180 ng/cm2 of amino acids and hydrazine on the sampler head through precision cleaning, control of materials, and vigilance. Contamination is further characterized via witness material exposed to the spacecraft assembly and testing environment as well as in space. This characterization provided knowledge of the expected background and will be used in conjunction with archived spacecraft components for comparison with the samples when they are delivered to Earth for analysis. Most of all, the cleanliness of the OSIRIS-REx spacecraft was achieved through communication among scientists, engineers, managers, and technicians.

Combined cytomorphologic and immunophenotypic analysis in the diagnostic workup of lymphomatous effusions.

OBJECTIVE: To analyze the results of cytomorphology and immunophenotyping in 54 patients with lymphomatous effusions. STUDY DESIGN: We report the results of cytomorphology and immunophenotyping in 54 patients with lymphomatous effusions. Twenty-three of the 54 had a previous diagnosis of NHL. In the remaining 31 patients, lymphomatous involvement was clinically suspected. RESULTS: Thirty-three lymphomatous effusions were positive for involvement by NHL. Twenty-one of these 33 patients (64%) had a previous diagnosis of NHL. Of the remaining 12 patients with newly diagnosed NHL, 11 had high grade lymphoma, and one had follicular center lymphoma. Twenty effusions were considered to be reactive; only two of these patients had NHL. One effusion revealed involvement by a previously unknown carcinoma. We observed seven false negative results if only one of both methods was considered. A high grade NHL was not diagnosed by immunophenotyping in one case, and six cases of low grade NHL could not be detected by cytomorphology. The combined strategy of cytomorphology and immunophenotyping had a sensitivity of 100% and specificity of 100% in our study, confirmed by follow-up studies. CONCLUSION: Both methods have shown difficulties in the examination of lymphomatous effusions. Cytomorphology has problems distinguishing reactive effusions from low grade NHL. The detection of high grade NHL by immunophenotyping is difficult. However, both methods together offer the advantage of dual staining ability and are most helpful in distinguishing clonal lymphomatous from reactive effusions.

Immunophenotypic analysis of simultaneous specimens from different sites from the same patient with malignant lymphoma.

Immunophenotypic analysis of simultaneous specimens from different sites from the same patient with malignant lymphoma The assumption that immunophenotypic characteristics of different specimens obtained simultaneously from the same patient remain unchanged has rarely been evaluated. Using flow cytometry, we reviewed our experience of 29 patients with non Hodgkin's lymphoma (NHL). From these patients, 60 simultaneous specimens taken from the peripheral blood, bone marrow, effusions, fine needle aspirates from lymph nodes or cerebrospinal fluid were studied. In 26 out of 29 patients, the immunophenotype in the different specimens was identical. In one patient with unclassifiable low-grade B-NHL, immunophenotyping showed additionally a CD38 expression in the effusion which was not seen in the bone marrow. In one patient with mantle cell lymphoma, expression of CD10 in the lymph node was noted which was lacking in the peripheral blood. In the remaining patient with unclassifiable low-grade B-NHL, CD23 expression was noted in the lymph node but not in the peripheral blood. This retrospective study suggests that discordant antigen expression in samples from different body sites within the same patient is a rare event.

Bioadhesion of supramolecular structures at supported planar bilayers as studied by the quartz crystal microbalance.

A quartz crystal microbalance (QCM) was used to study the adhesion behavior of supramolecular aggregates at supported planar bilayers (SPBs). The QCM technique is a suitable method to detect the adsorption of biomolecules at the quartz surface owing to its sensitivity for changes in mass and viscoelastic properties. To simulate biomembranes, the quartz plates were coated with highly ordered lipid films. Therefore, a combination of self-assembled monolayers and Langmuir-Blodgett films was used. Firstly, the adsorption of liposomes coupled with the lectin concanavalin A was investigated at glycolipid-containing model membranes. Using different carbohydrates, it was possible to determine specific and nonspecific parts of the interactions. The adhesion occurred owing to specific lectin-carbohydrate interactions (about 20%) and to nonspecific interactions (about 80%). The composition of the liposomes was changed to simulate the structure of a native biomembrane consisting of the glycocalix, the lipid-protein bilayer, and the cytoskeleton. An artificial glycocalix was created by incorporating poly(ethylene glycol) into the liposomes. Liposomes which were intravesicular polymerized with polyacrylamide or polyacrylcholate simulated the cytoskeleton. It was determined that the modified liposomes had significant lower interactions with SPBs. The adsorption was reduced by approximately 80% compared to unmodified liposomes. Secondly, a model was developed for the detection of interactions between simple or mixed bile salt micelles and model membranes. It was found that simple bile salts did not adsorb at model membranes. Binary systems consisting of bile salt and phospholipid induced only small interactions. On the other hand, ternary systems consisting of bile salt, phospholipid, and fatty acid showed strong interactions. A dependence on the chain length of the fatty acid was observed. Thirdly, the interaction between ganglioside-containing model membranes and cholera toxin (beta-subunit) was investigated. Different ganglioside fractions showed varying adsorption in the following sequence: GM1 > GD1a > GD1b > GT1b.

[Familial syringoma: a rare clinical variant]. / Familiäre Syringome. Eine seltene klinische Variante.

Syringomas usually occur either sporadically in a periorbital localized or truncal eruptive form. We report on two families with very uncommon hereditary syringomas. Multiple syringomas developed in the periorbital area of affected patients in the first family while the face, neck, trunk, and extremities were involved in the second family. The lesions first appeared during puberty and their number and distribution varied among the family members. Autosomal dominant inheritance equally affecting both sexes appears most likely. The incidence of familial syringomas may be widely underestimated. For treatment, carbon dioxide laser yielded good results while an excellent cosmetic outcome was achieved on the face with a special surgical technique using a springaction microscissors.

Masked intentions: the masquerade of killing thoughts used to justify dehydrating and starving people in a "persistent vegetative state" and people with other profound neurological impairments.

Denying food and water to profoundly impaired people who may not be conscious, or may only be "minimally" conscious, raises challenging ethical issues. While there is growing support for withdrawing/withholding food and water (assisted nutrition and hydration, or "AHN") from people described as being in a "persistent vegetative state" ("PVS") and people with other profound neurological impairments, such as advanced dementia, the issue remains controversial, and for many, unresolved. In this article, the author argues that if a profoundly impaired person is not imminently dying from a disease process, denying food and water causes him or her to die of dehydration and starvation. When provision of food and water does not create excessive burdens (such as extreme pain and discomfort), and if the food and water can be digested and absorbed, denying such nourishment is immoral and unethical. Under these circumstances, this denial (by commission or omission) is motivated by a real intention to cause death, whether or not that intention is explicitly recognized.

Lactate concentration in plasma and red blood cells during incremental exercise.

The purpose of this study was to investigate the distribution of lactate in plasma and red blood cells (RBC) in capillary blood during and after incremental exercise. We measured capillary plasma lactate and whole blood lactate of 10 subjects during incremental treadmill running and the first 20 min of recovery. To minimize lactate exchange from plasma to RBC between sampling and analysis, a recently developed rapid plasma separation method was used. RBC lactate was calculated. The RBC/plasma lactate concentration ratio decreased from 1.0 (0.85-1.28) before to 0.37 (0.25-0.45) after exhaustive exercise (plasma lactate 15.9 (12.2-19.5)mmol x I(-1), RBC lactate 4.8 (4.0-7.0) mmol x 1(-1)), thus showing that capillary plasma lactate increased much more rapidly than intracellular lactate during incremental exercise. In the first 5 minutes of recovery intracellular lactate still rose while plasma lactate already declined. Then both decreased while the concentration ratio as well as the absolute concentration gradient remained nearly constant (ratio 20 min after exercise termination: 0.43 (0.19-0.54).

The fall, recovery, orbit, and composition of the Tagish Lake meteorite: a new type of carbonaceous chondrite.

The preatmospheric mass of the Tagish Lake meteoroid was about 200,000 kilograms. Its calculated orbit indicates affinity to the Apollo asteroids with a semimajor axis in the middle of the asteroid belt, consistent with a linkage to low-albedo C, D, and P type asteroids. The mineralogy, oxygen isotope, and bulk chemical composition of recovered samples of the Tagish Lake meteorite are intermediate between CM and CI meteorites. These data suggest that the Tagish Lake meteorite may be one of the most primitive solar system materials yet studied.

Pregnancy in essential thrombocythaemia: treatment and outcome of 17 pregnancies.

OBJECTIVE: To evaluate treatment and outcome of 17 pregnancies in nine patients with essential thrombocythaemia (ET) seen at our institution from 1988 to 1998. METHODS: Treatment and outcome of 17 pregnancies in nine ET patients were retrospectively analyzed. RESULTS: Seventeen pregnancies in nine patients with ET resulted in 11 (65%) live births and ended in six (35%) spontaneous abortions. Abortion could not be predicted from ET-associated complications before (p= 0.23) or during (p = 0.39) pregnancy. Maternal complications occurred during six pregnancies (35%): Three major bleedings in two patients with an acquired von Willebrand disease and two minor bleedings in patients treated with low-dose acetylsalicylic acid (ASA) were observed during pregnancy or at term; one patient suffered from transient visual loss while pausing low-dose ASA. Platelet counts prior to pregnancy were significantly higher as compared to the platelet nadir observed during pregnancy (p = 0.0017). Postpartum clinical course was uneventful in all patients. No specific treatment was given during 11 pregnancies. Six women received low-dose ASA during pregnancy followed by low-molecular-weight heparin until the end of the sixth week postpartum in five cases. This treatment was correlated with a favourable outcome (live birth versus abortion) when compared to no treatment (p=0.04). CONCLUSION: Pregnancy in ET can be complicated by first trimester abortion and/or maternal haemorrhage. Our limited observation suggest a positive impact of low-dose ASA during pregnancy followed by low-molecular-weight heparin postpartum on pregnancy outcome in ET; nevertheless, confirmation by prospective documentation is mandatory.

Healing characteristics of small-calibre vascular prostheses coated with plasmin-treated fibrin--an experimental study.

BACKGROUND: The autogenous vein represents the graft material of choice in crural and pedal bypass surgery. Because of the numerous problems concerning the graft harvesting and the quality of autogenous vein material an equally good allogenous graft is urgently needed. Up to the present times no such graft material has been able to achieve the success of vein grafts. METHODS: We investigated the knitted polyester prosthesis Terumo PF-V (Terumo Comp., Japan), diameter 5 mm with outer reinforce, which is characterized by a new coating of plasmin-treated fibrin. Grafts were implanted as bypass into the ligated carotid (n = 10) and femoral arteries (n = 10) of 10 dogs (beagles). As a control 5 mm-ePTFE-prostheses (Impra Carboflo) were implanted simultaneously on the contralateral side. RESULTS: After 6 months, seven of 20 PF-V-grafts and 8 of 20 PTFE-grafts were patent. All prostheses presented with good macroscopic healing characteristics. In the patent grafts, angiography showed no substantial stenoses. The histological examination of the material was performed using light microscopy, transmission polarising microscopy, scanning electron microscopy, and transmission electron microscopy. Both types of prostheses showed the typical pattern of graft healing by migration of mesenchymal cells through the prosthesis, formation of capillaries, and growing of a neointima with endothelium-like cells. All failed bypass grafts presented with an occluding proliferation from the arterial wall into the anastomotic region. CONCLUSIONS: Using clinically or histologically evaluation, neither graft demonstrated superiority over the other. The results indicate that the coating plays only a minor role for graft healing if any. For proper graft function, the arterial wall proliferation at the anastomotic region, which is not dependent on the type of prosthesis, appears to be most important. The overall results concerning both types of prostheses were disappointing.

Diagnosis of granulocytic sarcoma by fine-needle aspiration cytology.

Granulocytic sarcoma (GS) occurs in patients with chronic myeloproliferative disorders as well as in patients with acute myeloid leukemia (AML). These tumorous masses can occur anywhere in the body and have to be differentiated from lymphoma, carcinoma or infectious processes. We report the results of fine-needle aspiration cytology (FNAC) in 26 patients with GS. Seventeen patients suffered from AML and 9 from chronic myeloid leukemia (CML) blast crisis. In 5 patients with AML, GS was the initial presentation of hematological malignancy, in the remaining 21 patients, FNAC confirmed relapse of AML or extramedullary blast crisis of CML. In 8 patients, GS was located in the skin, in 17 in the lymph node and in another patient in the spinal canal. This study demonstrates the clinical utility and diagnostic accuracy of FNAC in the evaluation of GS from multiple sites.

Fine needle aspiration cytology in extramedullary plasmacytoma.

OBJECTIVE: Extramedullary plasmacytoma is a rare plasma cell neoplasm. It can occur as the sole manifestation of plasma cell neoplasm, as a metastasis from another extramedullary plasmacytoma, as a solitary plasmacytoma of the bone or as a consequence of multiple myeloma. These plasma cell tumors can occur anywhere and have to be differentiated from other neoplasms, infectious processes and chloroma. STUDY DESIGN: We report the findings of fine needle aspiration cytology (FNAC) in 18 patients with extramedullary plasmacytoma. In six patients extramedullary plasmacytoma was the initial presentation of plasma cell neoplasm. In the remaining 12 patients the tumors occurred under or after treatment of plasma cell disease. RESULTS: Eleven lesions were located in the skin, seven in the lymph nodes, one in the liver and another in the spleen. Two patients with known diagnoses of plasma cell disease were thought, before FNAC, to have an infection, and two had a histologic diagnosis of non-Hodgkin's lymphoma. In 13 of 18 patients, cytologic smears showed anaplastic plasma cells. CONCLUSION: FNAC is a front-line investigative procedure in diagnosing extramedullary plasmacytoma.

[3D models for diagnosis and treatment planning in cardiology]. / 3D Modellierung zur Diagnose und Behandlungsplanung in der Kardiologie.

Due to the development new of imaging devices which produce a large number of tomographic slices, advanced techniques for the evaluation of the large amount of data are required. Computer supported extraction of dynamic 3D-models of the patients anatomy from temporal series thus is highly desirable. Since the diagnostician should be able to quickly make sensible decisions based on the models, high accuracy is required within a minimum of time. We present modeling and visualization techniques that are realized within the Cardiac Station. Results for the application of these techniques to cardiac image data demonstrate their usability. Besides giving information about the patients morphology functional parameters can be derived from the data and visualized together with the model. In order to verify the model with the original image data and for the planning of real intervention interaction techniques are presented.

Paroxysmal nocturnal haemoglobinuria: a replacement of haematopoietic tissue?

Acquired somatic mutations of the PIG-A gene lead to deficient expression of glycosyl-phosphatidyl-inositol-anchored proteins (GPI-AP) by haematopoietic cells and play a causative role in the pathogenesis of paroxysmal nocturnal haemoglobinuria (PNH). However, PIG-A mutations do not explain how the defective PNH clone can expand. It was hypothesized that a selection process conferring a relative advantage to the GPI-AP-deficient population is required. Since GPI-AP-deficient cells are also detectable in a substantial proportion of patients with otherwise typical aplastic anaemia (AA), the mechanisms inducing bone marrow failure might selectively spare the GPI-deficient cells. In order to examine the growth characteristics of GPI-AP-deficient cells in more detail, we performed repeated analyses of GPI-AP expression on peripheral blood cells in 41 patients with AA. We observed four patterns of the course of GPI-AP-deficient populations: (1) 13 patients showed normal expression of GPI-AP in the first analysis and in at least two follow-up studies at a median time of 709 days after the first analysis. (2) Secondary evolution of a GPI-AP-deficient population was a rare event. Only 4 patients with initially normal GPI-AP expression developed a GPI-AP-deficient population during follow up after immunosuppressive treatment. (3) Persistence of GPI-AP-deficient cells was observed in 16 patients during a median follow-up time of 774 days. However, in some patients, the size of the GPI-AP-deficient population increased substantially. (4) Disappearance of a GPI-AP-deficient population was observed in 8 patients. The time course of GPI-AP expression in relation to the treatment suggests that therapeutic interventions might modulate the ratio of normal versus GPI-AP-deficient haematopoiesis. Overall, these data argue against an 'absolute growth advantage' of GPI-AP-deficient cells. Our data are consistent with the hypothesis that haematopoietic failure caused by damage to normal haematopoiesis allows the outgrowth of a GPI-AP-deficient population. Thus, in at least some patients GPI-AP-deficient cells might pre-exist at a very low percentage and replace haematopoiesis after an insult to the normal cells.

[Congenital poikiloderma with verruciform hyperkeratoses (Dowling type)]. / Kongenitale Poikilodermie mit verruziformen Hyperkeratosen (Typ Dowling).

A male patient with congenital poikiloderma (type Dowling) developed Bowen's disease and initial squamous cell carcinoma. As the patient suffered from hypertriglyceridaemia (Frederickson type IV) and a long term tumor prophylaxis with retinoids was not appropriate, we attempted to treat the hyperkeratotic plaques with dermabrasion. After a period of six month we found complete healing of several plaques and only slight keratoses left in a few others. Long term follow up results are not yet available. Through this case report, the heterogenous clinical picture of congenital poikiloderma with warty hyperkeratoses and its high risk of malignancies is discussed.

Recent developments in the treatment of atopic eczema.

Atopic eczema remains a therapeutic challenge. However, new developments in the understanding of the pathogenesis of this complex disease have prompted new therapeutic strategies. This review focuses on recently described treatment modalities for atopic eczema that are currently available or under investigation. The effectiveness of phototherapy, cytokines, and immunosuppressive drugs is evaluated. In addition, some new and promising but still experimental approaches are discussed.

[Prurigo pigmentosa]. / Prurigo pigmentosa.

We report the first case of prurigo pigmentosa in the German literature. For over a year, a 16-year old white girl developed an immensely pruritic symmetrical reticular, papulovesicular eruption on the trunk, axillae and pubic region. Histologically a superficial perivascular spongiotic and lichenoid inflammatory pattern with prominent pigmentary incontinence in older lesions was observed. Topical corticosteroids and systemic antihistamines had no effect. Systemic corticosteroids and diaminophenylsulphone (DADPS) produced improvement but could not prevent recurrences. Healing occurred only after 4 weeks of systemic-minocycline.

Virtual reality in the operating room of the future.

In cooperation with the Max-Delbrück-Centrum/Robert-Rössle-Klinik (MDC/RRK) in Berlin, the Fraunhofer Institute for Computer Graphics is currently designing and developing a scenario for the operating room of the future. The goal of this project is to integrate new analysis, visualization and interaction tools in order to optimize and refine tumor diagnostics and therapy in combination with laser technology and remote stereoscopic video transfer. Hence, a human 3-D reference model is reconstructed using CT, MR, and anatomical cryosection images from the National Library of Medicine's Visible Human Project. Applying segmentation algorithms and surface-polygonization methods a 3-D representation is obtained. In addition, a "fly-through" the virtual patient is realized using 3-D input devices (data glove, tracking system, 6-DOF mouse). In this way, the surgeon can experience really new perspectives of the human anatomy. Moreover, using a virtual cutting plane any cut of the CT volume can be interactively placed and visualized in realtime. In conclusion, this project delivers visions for the application of effective visualization and VR systems. Commonly known as Virtual Prototyping and applied by the automotive industry long ago, this project shows, that the use of VR techniques can also prototype an operating room. After evaluating design and functionality of the virtual operating room, MDC plans to build real ORs in the near future. The use of VR techniques provides a more natural interface for the surgeon in the OR (e.g., controlling interactions by voice input). Besides preoperative planning future work will focus on supporting the surgeon in performing surgical interventions. An optimal synthesis of real and synthetic data, and the inclusion of visual, aural, and tactile senses in virtual environments can meet these requirements. This Augmented Reality could represent the environment for the surgeons of tomorrow.