Scanning gate microscopy mapping of edge current and branched electron flow in a transition metal dichalcogenide nanoribbon and quantum point contact.

We study scanning gate microscopy conductance mapping of a [Formula: see text] zigzag ribbon exploiting tight-binding and continuum models. We show that, even though the edge modes of a pristine nanoribbon are robust to backscattering on the potential induced by the tip, the conductance mapping reveals presence of both the edge modes and the quantized spin- and valley-current carrying modes. By inspecting the electron flow from a split gate quantum point contact (QPC) we find that the mapped current flow allows to determine the nature of the quantization in the QPC as spin-orbit coupling strength affects the number of branches in which the current exits the constriction. The radial conductance oscillation fringes found in the conductance mapping reveal the presence of two possible wavevectors for the charge carriers that correspond to spin and valley opposite modes. Finally, we show that disorder induced valley mixing leads to a beating pattern in the radial fringes.

[Do advance directives facilitate the process of dying in dignity?]. / Unterstützen Patientenverfügungen ein Sterben in Würde?

The benefit of an advance directive was evaluated by written questionnaires and personal interviews with relatives, nurses and physicians of recently deceased patients. The results indicate that a written advance directive is less important than ongoing communication between relatives or a designated person of trust, physicians and nurses. A standard advance directive however is helpful to initiate the discussion about the last will of a person. A further result of this survey is, that physicians and nurses do not feel confident in decision making regarding treatment and care of the dying. A written advance directive or a designated person of trust helping decisions making in the presumptive will of the patient, is seen as helpful.

Accumulation of activated CD4+ lymphocytes in the lung of individuals infected with HIV accompanied by increased virus production in patients with secondary infections.

The lung is continuously exposed to infectious and non-infectious agents causing cell activation. Activated cells in the lung such as antigen-presenting cells which harbour HIV may favour this organ as a site for virus production. To test this hypothesis, cells from blood and bronchoalveolar lavage (BAL) of HIV-infected patients and healthy controls were obtained and the activation of the cells were analysed by measuring the expression of IL-2 receptor, HLA-DR and VLA-1. The HIV-infected individuals were subdivided into 'lung symptomatic' or 'lung asymptomatic' patients, depending on the presence or absence of secondary lung diseases besides HIV. All HIV-infected individuals demonstrated a decreased number of CD4+ lymphocytes in blood; however, normal numbers of these cells were found in BAL. The activation state of CD4+ and CD8+ T lymphocytes in blood and BAL was higher in lymphocytes from HIV-infected patients compared with controls. The activation state was highest in the lung symptomatic group. Lung symptomatic patients and lung asymptomatic patients with extrapulmonary infections had increased levels of free virus in plasma. Four out of four individuals without or with only low amounts of cell-free HIV in plasma belonged to the symptom-free subgroup. These results suggest that microorganisms other than HIV may promote viral replication via antigen-driven accumulation and activation of CD4+ cells in the lung or other organs, and thus may be responsible for the loss of helper T cells and the progression of the disease.

[Superficial cerebral hemosiderosis: a rare cause of ataxia or hypoacusis]. / Haemosiderosis superficialis cerebri: seltene Ursache einer Ataxie und Hypakusis.

Superficial siderosis of the central nervous system (SSC) typically involves slowly progressive ataxia, hypoacusis and dementia, possibly with pyramidal signs and sphincter disturbances in combination with xanthochromic CSF with siderophages. However, there are also atypical oligosymptomatic forms. Before the era of magnetic resonance imaging (MRI), diagnosis was only possible at autopsy. Nowadays a firm diagnosis can be made during life by demonstrating the typical marginal hypointense signal in the T2-weighted images in the cerebrum, brain stem, cerebellum and spinal cord. Contrast-enhanced computed tomography may demonstrate widespread meningeal enhancement, but this sign is not specific for SSC. We present an oligosymptomatic case of SSC with slowly progressive ataxia and slight hypoacusis. The etiology, gross pathological and histopathological findings, differential diagnosis and therapy are discussed.

Post-discharge care planning and rehabilitation of the elderly surgical patient.

Successful discharge planning, home care, and rehabilitation for surgical patients can be very satisfying. However, everyone involved should be aware that it can also be frustrating when, despite careful plans and organization, everything falls apart, often because the patient's disease course is different from that expected or the patient or family are not satisfied with the services. There are multiple other reasons for plans to fail, but with experience the failures should become less frequent. All too often in life we take success for granted and weigh failures twice as much. The danger of this type of thinking becomes especially important in discharge planning--successfully discharged patients may be "invisible" but the failures are back very quickly. Everyone involved in discharge planning should be made aware of the successes in order to prevent "burn out." Certain predictable complications can often be prevented or rapidly reversed, and rehabilitation is achieved by a team of varied health care providers. A home visit is often very helpful before discharge of an elderly surgical patient.

Pseudoepithelial pattern in smears prepared from fine needle aspirates of plasmacytomas.

A pseudoepithelial pattern was observed in smears prepared from fine needle aspirates (FNA) from three plasmacytomas. In one case cells displayed a markedly granular, 'oncocytic' cytoplasm. Granularity of the cytoplasm was due to a large number of mitochondria as shown by electron microscopy. B-lymphocytic origin of the neoplasms was confirmed by immunocytochemistry.

Fine needle aspiration of the liver. Significance of hepatocytic naked nuclei in the diagnosis of hepatocellular carcinoma.

Fine needle aspiration (FNA) smears from 60 cases of histologically (34) or clinically (26) confirmed hepatocellular carcinomas were reviewed. In about 90% of the cases, the cytologic preparations contained clusters of malignant cells with variable degrees of hepatocytic features and a distinctive type of naked nuclei. These naked nuclei had features similar to those of the malignant hepatocytes, but with more evident atypia. They were numerous in about 75% of the cases and less frequent in 15%; in three cases, they were practically absent. All three cases of well-differentiated hepatocellular carcinomas presented with numerous naked nuclei with slight atypia. Flowerlike-configured naked nuclei were especially found in poorly differentiated hepatocellular tumors. Hepatocytic naked nuclei were rarely found in FNA smears from normal liver, metastases, cysts or degenerative, regenerative and inflammatory liver processes; when seen in these cases, they showed no atypia. The presence of atypical hepatocytic naked nuclei appears to be a very useful criterion for the diagnosis of hepatocellular carcinoma.

Morphological aspects of interactions between asbestos fibers and human mesothelial cell cytoskeleton.

The interaction of chrysotile and amphibole asbestos fibers with the cytoskeleton of cultured human mesothelial cells from nontumoral pleural effusions was studied using scanning electron and immunofluorescence microscopy. Asbestos-exposed mesothelial cells show a massive annular condensation of cytokeratin filaments, forming a concentric ring enveloping the nucleus and the phagocytosed asbestos fibers. By detergent extraction of the cells it could be shown that the asbestos fibers are in close contact with the nuclear membrane and associated with the cytoskeletal framework of the cells. An association of cytokeratin filaments with the asbestos could be observed during phagocytosis of the fibers. The disturbance of the cell cytoskeleton and the close morphologic contact between asbestos fibers and the nuclear membrane may have some relevance in explaining the well-recognized carcinogenic effects of asbestos mineral fibers.

Establishment and characterization of an Epstein-Barr virus nuclear antigen-negative hairy cell line.

Continuous cell lines have been established from spleen cells of patients with confirmed hairy cell leukemia (HCL). One cell line, HCL-Z1, lacks Epstein-Barr virus nuclear antigen (EBNA), grows attached to the substratum and retains typical features of hairy cells as revealed by transmission and scanning electron microscopy. HCL-Z1 differs morphologically from the three other EBNA-positive lymphoblastoid cell lines obtained (HCL-Z2, HCL-Z3, HCL-Z4) as well as from normal spleen cells or lymphocytes. The three lymphoblastoid cell lines derived from HCL patients show similar surface features as a line from a myeloma patient. Therefore, not all cell lines derived from HCL patients may be considered as representative of the patients leukemia cells.

High amylase content of neoplastic pleural and pericardial effusion probably secondary to amylase producing tumor cells: report of 2 cases.

We report two cases of malignant pleural and pericardial effusion respectively secondary to bronchogenic carcinomas. In both effusions, a significant elevation of the Salivary-type-amylase fraction was found, while the corresponding values were normal in serum and urine. Electronmicroscopy of the malignant tumor cells from the pleural effusion showed typical electron-dense granules, suggesting zymogen granules. It is concluded that the high amylase content of the effusions was due to secretion of S-type-isoamylase by the tumor cells.

Undulating tubules in lymphocytes of an apparently healthy human donor.

So-called 'undulating tubules' were found in the blood lymphocytes of an apparently healthy 33-year-old male. Undulating tubules have been noted to occur frequently in kidney cells and blood lymphocytes of patients suffering from collagen diseases and especially from SLE. They have been suggested to be a possibly pathognomonic finding in such diseases. Our result seems to contradict such an association.

Occurrence of plasmocytoid cells in long-term blood-cell cultures from a patient with 'hairy cell' leukemia.

Cells from the peripheral blood of a patient with 'hairy cell' leukemia were cultivated in long-term cultures. They grew with a monolayer growth pattern and consisted of at least two cell populations. The electron microscopic morphology of the cultivated cells revealed cells resembling 'hairy cells' showing the typical cytoplasmic protrusions and cells with structural characteristics of plasma cells.

Giant platelets and fibrin-like inclusions in platelets of BALB/c mice after intraperitoneal inoculation of HIPA tumour agent.

2 days after ip inoculation of cell-free extracts of HIPA tumour, giant platelets and platelets with band-like inclusions were found in blood of BALB/c mice. Band-like inclusions with platelets have morphologic structure of fibrin. Their presence in the thrombocytes is probably an accidental finding. Giant platelets in the circulating blood are probably due to a disturbed meagacaryocytopoiesis.

Virus-bearing plasma cells in peripheral blood of a patient with 'hairy cell' leukemia.

Electron-microscopic examination of peripheral blood from a patient with 'hairy cell' leukemia revealed classical 'hairy cells', atypical lymphoid cells and numerous pathological plasma cells. Osmiophilic granular material coated the cell surface of 'hairy cells' and lymphoid cells but not the plasmalemma of the plasma cells. The most important features of the plasma cells were cytoplasmic protrusions and masses of oncogenic virus A particles in their endoplasmic reticular cisternae.