Anisotropic thermal conductivity of AlGaN/GaN superlattices.

High thermal conductivity is an important parameter for nitride-based power electronic and deep-UV light emitters. Especially in the latter case short period superlattices and multicomponent alloys are used and the knowledge of the thermal properties of the binary compounds is sufficient. In-plane and cross-plane thermal conductivity of AlGaN/GaN superlattices were measured by differential two-wire 3ω method in the temperature range from 147 to 325 K. Samples were grown by metalorganic vapor phase epitaxy; the structure quality and accuracy of superlattice structures preparation were verified by means of HRXRD and transmission electron microscopy. It was observed, that value of thermal conductivities decrease with decreasing period thickness, while temperature dependencies differ from each other-in-plane thermal conductivity decreases, and cross-plane-increases with increasing temperature. Callaway method was used for thermal conductivity calculation; dependence of boundary scattering rate on the phonon wavelength was taken into account. Minimum thermal conductivity was added to calculated values to include the influence of high frequency acoustic phonons and optical phonons on the heat transport. Calculations are in good agreement with experimental results.

Hyperkeratosis in human lower limb lymphedema: the effect of stagnant tissue fluid/lymph.

BACKGROUND: Hyperkeratosis of skin in lower limb lymphedema is one of the sequelae of tissue fluid/lymph (TF/L) stasis, but its mechanisms remain unknown. It is noteworthy, nonetheless, that human TF/L contains high levels of growth factors and cytokines, and may serve as the physiological environment for keratinocyte (KC) proliferation. OBJECTIVE: The aim of the study was to investigate the effect of human TF/L on human KC proliferation, differentiation and on the expression of epidermal stem cell markers on them. METHODS: KC were isolated from lymphedema and normal skin, and cultured for 1-14 days in TF/L with neutralized Interleukin 1ß, Interleukin 6, tumour necrosis factor α (TNF-α), keratinocyte growth factor (KGF) or tumour growth factor ß (TGF-ß). Alternatively, KC receptors for these factors were blocked. RESULTS: The number of KC cultured in TF/L was increased, as was the percentage of mitotic figures. There was a higher percentage of p63, CD29, Ki67, PCNA, CK6, CK17, CK16 and a lower of CK10, CK14, filaggrin and involucrin-positive KC. Neutralization of TF/L IL-1ß, IL-6, TNF-α and KGF as well as blockage of their receptors resulted in decreased percentage of mitotic KC. TGF-ß had a limited effect on KC proliferation. CONCLUSION: Hyperkeratosis in lymphedema may be the effect of a high concentration of cytokines in the stagnant TF/L tissue, but not because of presumed changes in the KC.

[Molecular diagnostics of lung cancer]. / A tüdorák molekuláris diagnosztikája.

Development of the target therapies of lung cancer was a rapid process which fundamentally changed the pathological diagnosis as well. Furthermore, molecular pathology became essential part of the routine diagnostics of lung cancer. These changes generated several practical problems and in underdeveloped countries or in those with reimbursement problems have been combined with further challenges. The central and eastern region of Europe are characterized by similar problems in this respect which promoted the foundation of NSCLC Working Group to provide up to date protocols or guidelines. This present paper is a summary of the molecular pathology and target therapy guidelines written with the notion that it has to be upgraded continuously according to the development of the field.

Training and practice of cytotechnologists: a discussion forum focused on Europe.

OBJECTIVES: To discuss the role and training of cytotechnologists (CTs) in Europe, to identify areas of good practice and to provide an informed opinion to those providing guidelines for training and practice in Europe. METHODS: All members of the Editorial Advisory Board of Cytopathology were invited to take part in a 'discussion forum' for which six topics were circulated in advance concerning the roles of CTs with regard to: (1) pre-screening slides; (2) 'signing out' reports; (3) carrying out ancillary techniques; (4) supervising laboratory staff; (5) taking part in rapid on-site evaluation (ROSE) of fine needle aspirates (FNAs); and (6) whether CTs were trained specifically in cytopathology or in general histopathology. Notes of the meeting were circulated by email and a final report was agreed by 22 participants from 17 predominantly European countries. RESULTS: Training for CTs throughout Europe was variable, especially for non-gynaecological cytology, which was inconsistent with the range of activities required. The participants recommended graduate entry, preliminary training in general laboratory technology, and subsequent training to take account of the probability and, in some centres, the reality of primary cervical cancer screening changing from cytology to human papillomavirus (HPV) testing. They further recommended that CTs should perform HPV tests and take part in ROSE for FNAs, and they supported the European Federation of Cytology Societies developing guidelines for training and practice. CONCLUSION: With CT training added to a university-based education in laboratory or biomedical science, a career in cytotechnology should be an attractive option involving a diverse range of laboratory and clinically based activities.

Lymphovenous microsurgical shunts in treatment of lymphedema of lower limbs: a 45-year experience of one surgeon/one center.

RATIONALE: The use of microsurgical lymphovenous shunts is one of the generally accepted treatments for limb lymphedema. AIM: The 45-year personal experience of one surgeon in indications, technique and results of lymphovenous shunt operations in lower limb lymphedema of varying etiology is presented. MATERIAL: One thousand three hundred patients were followed up in the period 1966-2011. Patients were classified into groups according to the etiology of lymphedema as postinflammatory/posttraumatic, postsurgical, idiopathic and hyperplastic. Decrease in limb circumference, heaviness and pain, and increase in joint flexing were evaluated. RESULTS: The most satisfactory results, reaching 80-100% improvement, were obtained in the congenital non-hereditary hyperplastic lymphedema group, with large lymphatics not previously damaged by infection. Results were also satisfactory in the group of cancer patients after iliac lymphadenectomy, reaching 80%. A less satisfactory outcome was observed in the postinflammatory group, not exceeding 30-40%. In idiopathic lymphedema results were satisfactory in only a few cases. CONCLUSIONS: Patients with lymphedema with local segmental obstruction but still partly patent distal lymphatics and without an active inflammatory process in the skin, subcutaneous tissue and lymph vessels present satisfactory results.

Magnetic resonance lymphography (MRL): point and counter-point.

Two preeminent lymphologists debate the findings, implications, interpretations, and value of magnetic resonance lymphography (MRL) in the evaluation of peripheral lymphedema. Their contrasting views are discussed in the context of different lymphatic imaging modalities including MRL, lymphoscintigraphy, and microscopic anatomy.

Pathways of lymph and tissue fluid flow during intermittent pneumatic massage of lower limbs with obstructive lymphedema.

Questions remain on the use of sequential pneumatic compression including where does the fluid flow to and whether fluid can be moved to the non-swollen tissues of the hypogastrium and gluteal region? During pneumatic massage of the limb, we studied pathways of lymph and mobile tissue fluid flow using lymphoscintigraphy: a) from the calf and thigh across the inguinal region to the healthy non-swollen tissues of the hypogastrium and b) in the hypogastrium to the lateral and upper abdominal quadrants. To examine if there was effective fluid flow during pneumatic massage, plethysmographic flow measurements were also carried out. We demonstrated that: (i) pneumatic compression moved isotope in lymph remaining in functioning lymphatics and in tissue fluid in the interstitial space toward the inguinal region and femoral channel, (ii) there was no isotope crossing the inguinal crease or moving to the gluteal area, and (iii) isotope injected intradermally in the hypogastrium did not spread during manual massage to the upper and contralateral abdominal quadrants. In conclusion, intermittent pneumatic compression is effective in pushing mobile tissue fluid and relocating large fluid volumes toward the groin. However, the question that still remains is how to facilitate further flow toward the non-swollen tissues and thereby increase local absorption of fluid.

Survey of medical training in cytopathology carried out by the journal Cytopathology.

This report of the Editorial Advisory Board of Cytopathology gives the results of a survey of medical practitioners in cytopathology, which aimed to find out their views on the current situation in undergraduate and postgraduate training in their institutions and countries. The results show that training in cytopathology and histopathology are largely carried out at postgraduate level and tend to be organized nationally rather than locally. Histopathology was regarded as essential for training in cytopathology by 89.5% of respondents and was mandatory according to 83.1%. Mandatory cytopathology sections of histopathology were reported by 67.3% and specific examinations in cytopathology by 55.4%. The main deficiencies in training were due to its variability; there were insufficient numbers of pathologists interested in cytology and a consequent lack of training to a high level of competence. Pathologists without specific training in cytopathology signed out cytology reports according to 54.7% of responses, more often in centres where training was 3-6 months or less duration. Although 92.2% of respondents thought that specialist cytology should not be reported by pathologists without experience in general cytopathology, that practice was reported by 30.9%, more often in centres with small workloads. The survey report recommends that 6-12 months should be dedicated to cytopathology during histopathology training, with optional additional training for those wanting to carry out independent practice in cytopathology. Formal accreditation should be mandatory for independent practice in cytopathology. When necessary, temporary placements to centres of good practice should be available for trainees intending to practise independently in cytopathology. There should be adequate numbers of pathologists trained in cytopathology to a high level of competence; some of their time could be released by training cytotechnologists and trainee pathologists to prescreen cytology slides and assess adequacy of fine-needle aspiration samples when immediate diagnosis was not required. The survey demonstrated a clear need for European and international guidelines for training in cytopathology.

Lack of functioning lymphatics and accumulation of tissue fluid/lymph in interstitial "lakes" in colon cancer tissue.

There is controversy as to whether intratumoral or peritumoral lymphatics play a dominant role in the metastatic process. The knowledge of how and where exactly tumor cells enter lymphatics is important for therapeutic targeting either the tumor core or peritumoral tissue with drugs or radiation. The basic questions remain: what is the morphological structure of intra- and peritumoral interstitium and lymphatics; what is their hydraulic conductivity?; and do these local physical conditions allow detached tumor cells to migrate to lymphatics? Identification of lymphatics has been based on immunohistochemical staining of lymphatic endothelial cells. This method does not, however, show the tissue fluid filled interstitial space and the shape of minute lymphatic vessels in tumors. We visualized the interstitial space and lymphatics in the central and peripheral regions of tumors using our original method of color stereoscopic lymphography in translucent tissue fragments and simultaneously with immunohistochemical staining of lymphatic and blood endothelial cells. The density of open and compressed lymphatic and blood vessels was measured in the intratumoral "hot spots" and at tumor edge. Moreover, the intratumoral tissue hydraulic conductivity was measured to define force necessary for propelling tissue fluid to peritumoral lymphatics. We found very few rudimentary minor blind lymphatics in the tumor core and numerous minor fluid "lakes" in the interstitium with no visible connection to the peritumoral lymphatics. Lining of "lakes" did not express molecular markers specific for lymphatic endothelial cells. Ninety-five percent of structures of what looked like lymphatics had compressed lumen and the hydraulic conductivity was 3 powers of magnitude lower than in the adjacent non-tumoral tissue. It can be concluded that lack of functioning lymphatics in tumor foci manifested by accumulation of tissue fluid in "lakes," low fluid conductivity and compression of lymphatics by tumor cells, and proliferating connective tissue may hamper escape of tumor cells. The most favorable site of entry of tumor cells to lymphatics seems to be the interface of the tumor and surrounding tissue with open lymphatics.

Where do lymph and tissue fluid accumulate in lymphedema of the lower limbs caused by obliteration of lymphatic collectors?

Obliteration of lymphatic collecting trunks of limbs by infective processes, trauma, oncologic surgery and irradiation bring about retention of lymph and tissue fluid in tissues. Knowledge as to where excess lymph is produced and accumulates as tissue fluid is indispensable for rational physical therapy. So far, this knowledge has been based on lymphoscintigraphic, ultrasonographic and MR images. None of these modalities provides distinct images of dilated lymphatics and fluid expanded tissue spaces in dermis, subcutis and muscles. Only anatomical dissection and histological processing of biopsy material can demonstrate the remnants of the lymphatic network and the sites of accumulation of mobile tissue fluid. We visualized and calculated the volume of the "tissue fluid and lymph" space in skin and subcutaneous tissue of foot, calf, and thigh in various stages of lymphedema, using special coloring techniques in specimens obtained during lymphatic microsurgical procedures or tissue debulking. When the collecting trunks were obliterated, lymph was present only in the subepidermal lymphatics, while mobile tissue fluid accumulated in the spontaneously formed spaces in the subcutaneous tissue, around small veins, and in the muscular fascia. Deformation of subcutaneous tissue by free fluid led to formation of interconnecting channels. In obstructive lymphedema caused by obliteration of collectors, lymph is present mainly in subepidermal lymphatics, and the bulk of stagnant tissue fluid accumulates in subcutis between fibrous septa and fat globules as well as above and underneath muscular fascia. These observations provide useful clues for designing pneumatic devices and rational manual lymphatic massage to move stagnant tissue fluid toward the non-swollen regions.

How to diagnose splenic abscesses?

Splenic abscess is a rare but potentially fatal entity, occurring mainly in patients with underlying risk factors. Mortality of the disease depends on the time of diagnosis and treatment. Due to low sensitivity and specificity of clinical symptoms and laboratory markers, imaging plays the vital role in the diagnostic work-up. The aim of this article is to give a concise overview of the methods of splenic abscess diagnosis.

The role of breast FNAC in diagnosis and clinical management: a survey of current practice.

Most participating countries have now adopted a triple assessment approach, i.e. clinical,imaging and pathology, to breast diagnosis, with FNAC as the first-line pathological investigation in both screening and symptomatic populations, with the exception of microcalcifications. Pathologists specialized in cytopathology are best qualified to collect and interpret FNAC samples, but this is not always possible or practical. Radiologists involved in breast imaging should ensure that they have the necessary skills to carry out FNAC under all forms of image guidance. Best results are achieved by a combination of both techniques, as shown in the image-guided FNAC in the presence of the cytopathologist. The majority of European countries use similar reporting systems for breast FNAC (C1-C5), in keeping with European Guidelines for Quality Assurance in Breast Cancer Screening and Diagnosis, although some still prefer descriptive reporting only. When triple assessment is concordant, final treatment may proceed on the basis of FNAC, without a tissue biopsy. ER and PR assessment can be done safely on FNAC material. However, not all institutions may have expertise in doing this. HER-2 protein expression on direct cytological preparations is insufficiently reliable for clinical use, although its use for FISH is possible, if expertise is available. The majority of participants practise a degree of one-stop diagnosis with a cytopathologist present in the out-patient clinic. Formal recognition of the importance of the time spent outside the laboratory, both for cytopathologist and cytotechnologist, is necessary in order to ensure appropriate resourcing. The use of core biopsy (CB) has increased, although not always for evidence-based reasons. CB and FNAC are not mutually exclusive. FNAC should be used in diagnosis of benign, symptomatic lesions and CB in microcalcifications, suspicious FNAC findings and malignancies where radiology cannot guarantee stromal invasion.

Cellulitis and bacteria in peripheral lymphedema.

Counterpoint to the article: Peculiar Clinical Features of Cellulitis in Peripheral Lymphedema, K. Suehiro, et al. Lymphology Vol 51, No 2, pp 47-53.

Preservation of molecular structure of arterial grafts in pulverized sodium chloride: an experimental study.

There is a desperate need for preserved human arteries to be transplanted in infected areas of ischemic lower limbs. Cryopreserved arteries are fragile evoking strong allogeneic reactions. We have been searching for a preservation method that spares arterial wall structure and decreases its antigenicity. LEW and BN rat segments of aorta were harvested, immersed in pulverized dehydrated sodium chloride, and stored for 1 week to 3 months. Thereafter, they were desalinated and transplanted side-to-side to the abdominal aorta and side-to-side to the aorta-IVC (AV fistula). We performed staining for actin, elastic fibers, collagen (trichrome), CD31, endothelial cells (HIS52), MHC class II. Popliteal lymph node reactions were tested after subcutaneous implantation of an aortic fragment into the paw. We measured tensile strength and maximum intraluminal pressures. The preserved fragments of syngeneic aorta retained their cellular, stromal, and molecular structures. After transplantation, they did not evoke any reaction around the graft. The allogeneic fragments brought about only minor recipient responses, remaining patent and pulsatile for 3 months. The tensile strength and maximum intraluminal pressures did not significantly differ from freshly harvested, transplanted aortic segments.

Determination of hyperfine fields orientation in nuclear probe techniques.

One of the most popular nuclear probes, 57Fe is used for the investigation of orientations of hyperfine fields and also for the determination of other important properties. In particular, the orientation of iron magnetic moments can be unambiguously determined, including its signs. Experiments with polarized radiation are presented with regard to selected systems. Orientation of electric field gradient is used for acquiring information about the shape of the texture-free spectra. Applications on the analysis of iron-based superconductors are presented.

Local microscopic properties and annealing effect of Rb0.85Fe1.9Se2 single crystals.

Investigation of mesoscopically phase-separated Rb0.85Fe1.9Se2 single crystals has been performed and two iron sites: nonmagnetic and magnetic ones, were observed by Mössbauer spectroscopy. The softening of the nonmagnetic one, having clearly more soft dynamics, was found to be gained further by the annealing of the single crystals at phase separation temperature, T p, leading to the reduction of size of initially separated domains and their more homogenous distribution in the tetragonal matrix of the studied sample. The magnetic Fe sites of Rb0.85Fe1.9Se2 show strong magnetic texture, indicating the perpendicular to the ab-plane orientation of the iron magnetic moments. It was found that the annealing at T p causes a systematic decrease of the isomer shift of the doublet by 0.02(1) mm s-1.

Human splenic dendritic cells react differently to bacterial and allogeneic antigens.

We investigated the ability of bacterial (cells, LPS, and DNA) or allogeneic antigens to stimulate splenic dendritic cells (DCs) and expression of Toll-like receptors (TLRs), CD14 (co-functional molecule to TLR), CD83 (activation molecule on migrating DCs), CD123 (IL-3R specific for myeloid DC), Hsp60 and Hsp90 (heat shock proteins) involved in recognizing pathogen-associated molecular patterns (PAMP) and other pathogen recognition receptors (PRR) ligands. Allogeneic stimulation of DC TLRs was weak compared with that of bacterial products. This suggests that the highly conserved TLRs destined to react to bacterial products do not recognize donor products differing at the major histocompatibility complex (MHC) locus, at least using in vitro culture conditions.

Endogeneous sources of infection in transplant recipients.

The mammal organisms carry on their surfaces and in their tissues cohorts of microorganisms of various nature. There is a balance of interests and profits between the host and microbial inhabitants. The bacteria and fungi behave like comensals, colonizers, dormants, however, under certain, mostly unknown, conditions may evoke reaction of the host. This process is damaging both for the host and microbes. Large surgical trauma and allograft itself, as well as, immunosuppression create favorable conditions for imbalance between inhabiting microorganism and the recipient. The host flora and that transplanted with the organ graft become activated. Active combating of the proliferating bacteria with antibiotics becomes necessary. Our knowledge of the bacterial flora of the so called "sterile" tissues remains rudimentary. There is still a great deal of prejudice on the sterility of deep tissues e.g. muscles, fat tissue, etc. This review cumulates pertinent literature data on the microorganisms-host interactions. Our own findings on colonization of arteries and adjacent tissues are discussed in the context of atherosclerosis and grafting.

DNA in situ sensitivity to denaturation as a marker of human breast tumors.

DNA content and in situ sensitivity to denaturation were analyzed by flow cytometry of individual cell nuclei isolated from 40 breast carcinomas, nine fibroadenomas, and 14 samples of normal breast tissue. The extent of DNA denaturation induced by acid was expressed as alpha t, which represents the fraction of DNA staining metachromatically red with the fluorochrome acridine orange. In all cases of normal breast tissue DNA was very sensitive to denaturation and the frequency distribution of alpha t values was unimodal with over 90% of cells having alpha t above 0.6. All fibroadenomas were diploid; four had unimodal alpha t as in normal tissue and five had a bimodal distribution with an additional peak below 0.6. Twenty-seven adenocarcinomas (67%) had a DNA index above 1.0; of these 24 had bimodal alpha t distributions. Among 13 diploid carcinomas 10 had bimodal alpha t distributions. Statistically significant differences were observed in alpha t distributions of normal versus tumor breast tissue (P less than 0.005). In normal tissue and in all tumors a predominant proportion of cells with S and G2 + M DNA content were characterized by DNA resistant to denaturation (alpha t below 0.6). Of interest, the diploid cells from aneuploid tumors which may represent reactive host cells often displayed bimodal distributions of alpha t. These results may be interpreted in light of earlier studies demonstrating increased resistance of DNA to denaturation in diffuse chromatin of proliferating and/or transcriptionally active cells, and greater sensitivity to denaturation of DNA in condensed chromatin of quiescent cells. Thus, the presence of the second peaks representing cells with low alpha t values in breast tumors may indicate a high proportion of proliferating cells, whereas high alpha t populations may represent quiescent and differentiating (condensed chromatin) or dying (pycnotic nuclei) cells. It is likely that the low alpha t diploid cells detected in aneuploid tumors may represent the reactive (transcriptionally active and/or proliferating) infiltrating host cells (i.e., lymphocytes, monocytes) whose presence may also be of prognostic value. The data suggest that a DNA denaturability assay may be useful to characterize tumor and infiltrating host cell populations.

Temperature dependent local atomic displacements in ammonia intercalated iron selenide superconductor.

Recently, ammonia-thermal reaction has been used for molecular intercalation in layered FeSe, resulting a new Lix(NH3)yFe2Se2 superconductor with Tc ~ 45 K. Here, we have used temperature dependent extended x-ray absorption fine structure (EXAFS) to investigate local atomic displacements in single crystals of this new superconductor. Using polarized EXAFS at Fe K-edge we have obtained direct information on the local Fe-Se and Fe-Fe bondlengths and corresponding mean square relative displacements (MSRD). We find that the Se-height in the intercalated system is lower than the one in the binary FeSe, suggesting compressed FeSe4 tetrahedron in the title system. Incidentally, there is hardly any effect of the intercalation on the bondlengths characteristics, revealed by the Einstein temperatures, that are similar to those found in the binary FeSe. Therefore, the molecular intercalation induces an effective compression and decouples the FeSe slabs. Furthermore, the results reveal an anomalous change in the atomic correlations across Tc, appearing as a clear decrease in the MSRD, indicating hardening of the local lattice mode. Similar response of the local lattice has been found in other families of superconductors, e.g., A15-type and cuprates superconductors. This observation suggests that local atomic correlations should have some direct correlation with the superconductivity.