Patterns of single-neuron activity during associative recognition memory in the human medial temporal lobe.

Electrophysiological activity in medial temporal lobe (MTL) structures is pivotal for declarative long-term memory. Single-neuron and microcircuit findings capitalizing on human microwire recordings from the medial temporal lobe are still fragmentary. In particular, it is an open question whether identical or different groups of neurons participate in different memory functions. Here, we investigated category-specific responses in the human MTL based on single-neuron recordings in presurgical epilepsy patients performing an associative long-term memory task. Additionally, auditory beat stimuli were presented during encoding and retrieval to modulate memory performance. We describe the proportion of neurons in amygdala, entorhinal cortex, hippocampus and parahippocampal cortex belonging to different response classes. These entail neurons coding stimulus-familiarity, neurons coding successful item memory, and neurons coding associated source memory, as well as the overlap between these classes. As major results we demonstrate that neurons responding to stimulus familiarity (old/new effect) can be identified in the MTL even when using previously known rather than entirely novel stimulus material (words). We observed a significant overlap between familiarity-related neurons and neurons coding item retrieval (remembered/forgotten effect). The largest fraction of familiarity-related neurons was found in the parahippocampal cortex, and a considerable fraction of all parahippocampal neurons was related to successful item retrieval. Neurons related to successful source retrieval were different from the neurons coding the associated information. Most importantly, there was no overlap between neurons coding item memory and those coding associated source memory strongly suggesting that these functions are facilitated by different sets of neurons.

A unified form of low-energy nodal electronic interactions in hole-doped cuprate superconductors.

Using angle resolved photoemission spectroscopy measurements of Bi2Sr2CaCu2O8+δ over a wide range of doping levels, we present a universal form for the non-Fermi liquid electronic interactions in the nodal direction in the exotic normal state phase. It is described by a continuously varying power law exponent versus energy and temperature (hence named a Power Law Liquid or PLL), which with doping varies smoothly from a quadratic Fermi Liquid in the overdoped regime, to a linear Marginal Fermi Liquid at optimal doping, to a non-quasiparticle non-Fermi Liquid in the underdoped regime. The coupling strength is essentially constant across all regimes and is consistent with Planckian dissipation. Using the extracted PLL parameters we reproduce the experimental optics and resistivity over a wide range of doping and normal-state temperature values, including the T* pseudogap temperature scale observed in the resistivity curves. This breaks the direct link to the pseudogapping of antinodal spectral weight observed at similar temperature scales and gives an alternative direction for searches of the microscopic mechanism.

Intracranial EEG correlates of implicit relational inference within the hippocampus.

Drawing inferences from past experiences enables adaptive behavior in future situations. Inference has been shown to depend on hippocampal processes. Usually, inference is considered a deliberate and effortful mental act which happens during retrieval, and requires the focus of our awareness. Recent fMRI studies hint at the possibility that some forms of hippocampus-dependent inference can also occur during encoding and possibly also outside of awareness. Here, we sought to further explore the feasibility of hippocampal implicit inference, and specifically address the temporal evolution of implicit inference using intracranial EEG. Presurgical epilepsy patients with hippocampal depth electrodes viewed a sequence of word pairs, and judged the semantic fit between two words in each pair. Some of the word pairs entailed a common word (e.g., "winter-red," "red-cat") such that an indirect relation was established in following word pairs (e.g., "winter-cat"). The behavioral results suggested that drawing inference implicitly from past experience is feasible because indirect relations seemed to foster "fit" judgments while the absence of indirect relations fostered "do not fit" judgments, even though the participants were unaware of the indirect relations. A event-related potential (ERP) difference emerging 400 ms post-stimulus was evident in the hippocampus during encoding, suggesting that indirect relations were already established automatically during encoding of the overlapping word pairs. Further ERP differences emerged later post-stimulus (1,500 ms), were modulated by the participants' responses and were evident during encoding and test. Furthermore, response-locked ERP effects were evident at test. These ERP effects could hence be a correlate of the interaction of implicit memory with decision-making. Together, the data map out a time-course in which the hippocampus automatically integrates memories from discrete but related episodes to implicitly influence future decision making.

Effects, determination, and correction of count rate nonlinearity in multi-channel analog electron detectors.

Detector counting rate nonlinearity, though a known problem, is commonly ignored in the analysis of angle resolved photoemission spectroscopy where modern multichannel electron detection schemes using analog intensity scales are used. We focus on a nearly ubiquitous "inverse saturation" nonlinearity that makes the spectra falsely sharp and beautiful. These artificially enhanced spectra limit accurate quantitative analysis of the data, leading to mistaken spectral weights, Fermi energies, and peak widths. We present a method to rapidly detect and correct for this nonlinearity. This algorithm could be applicable for a wide range of nonlinear systems, beyond photoemission spectroscopy.

Low-energy (<10 meV) feature in the nodal electron self-energy and strong temperature dependence of the Fermi velocity in Bi{2}Sr{2}CaCu{2}O{8+δ}.

Using low photon energy angle-resolved photoemission, we study the low-energy dispersion along the nodal (π,π) direction in Bi{2}Sr{2}CaCu{2}O{8+δ} as a function of temperature. Less than 10 meV below the Fermi energy, the high-resolution data reveal a novel "kinklike" feature in the electron self-energy that is distinct from the larger well-known kink roughly 70 meV below E{F}. This new kink is strongest below the superconducting critical temperature and weakens substantially at higher temperatures. A corollary of this finding is that the Fermi velocity v{F}, as measured in this low-energy range, varies rapidly with temperature-increasing by almost 30% from 70 to 110 K. The behavior of v{F}(T) appears to shift as a function of doping, suggesting a departure from simple "universality" in the nodal Fermi velocity of cuprates.

Altered function of the hypothalamic stress axes in patients with moderately active systemic lupus erythematosus. I. The hypothalamus-autonomic nervous system axis.

OBJECTIVE: To determine the human corticotropin releasing hormone (hCRH) induced stress response of the hypothalamus-autonomic nervous system axis (HANS) in patients with moderately active systemic lupus erythematosus (SLE). METHODS: Cardiovascular and pupillary function variables were measured by standardized computer procedures before and during an hCRH test (6 time points). The results of 12 patients with SLE were compared to 24 healthy subjects with (HS+P, n = 12) and without (HS, n = 12) prior administration of prednisolone 3 days before the test. RESULTS: At baseline, diastolic blood pressure was significantly higher in SLE than in HS or HS+P (p<0.001). During the hCRH test, patients with SLE had increased heart rates and systolic and diastolic blood pressure responses compared to HS+P and HS (p<0.001 for all comparisons). Moreover, heart rate variation was decreased at rest, during the lying-to-standing procedure, and during the 2 applied respiratory tests (p<0.01 vs. HS). Compared to HS+P and HS, latency time of the pupillary light reflex was prolonged and maximal pupillary area was increased, revealing sympathetic hyperreactivity. CONCLUSION: This study found an altered autonomic nervous system response at baseline, which was more pronounced during the hCRH stress test in patients with moderately active SLE compared to healthy subjects. Baseline and stress responses are characterized by a sympathetic overstimulation. Such a hypersympathetic reaction may lead to increased risk of cardiovascular diseases in patients with moderately active SLE, which needs to be investigated in longitudinal studies.

Altered function of the hypothalamic stress axes in patients with moderately active systemic lupus erythematosus. II. Dissociation between androstenedione, cortisol, or dehydroepiandrosterone and interleukin 6 or tumor necrosis factor.

OBJECTIVE: To investigate adrenocorticotropin, androstenedione (ASD), cortisol, or dehydroepiandrosterone sulfate (DHEAS) before and during a corticotropin releasing hormone (hCRH) test in patients with moderately active systemic lupus erythematosus (SLE) undergoing low dose longterm glucocorticoid therapy, and to examine these hormones in relation to interleukin 6 (IL-6) or tumor necrosis factor (TNF). METHODS: Serum levels of hormones and cytokines were measured before and during an hCRH test. The results of 12 patients with SLE were compared to 12 healthy subjects (HS) and 12 healthy subjects given prior short term prednisolone (HS+P). RESULTS: Baseline and stimulated serum ASD, cortisol, and DHEAS were lower in patients with SLE vs. HS (p<0.005), but baseline and stimulated plasma adrenocorticotropin was normal in SLE. In SLE, but not in HS+P or HS, baseline and stimulated DHEAS was low in relation to cortisol or ASD (i.e., shift from DHEAS to cortisol or ASD). In patients with SLE, baseline and stimulated serum levels of adrenal hormones were lower in relation to IL-6 or TNF compared to HS or HS+P (p< 0.001). In contrast, in SLE patients, the baseline and stimulated pituitary hormone adrenocorticotropin was normal in relation to these cytokines. CONCLUSION: We found marked adrenal insufficiency and a shift in steroidogenesis to cortisol in patients with SLE, but a completely normal pituitary function (in absolute values and in relation to IL-6 or TNF). This may depend in part on prior longterm glucocorticoid therapy and changes of steroidogenesis due to cytokines. The situation in patients with SLE was not mimicked by high dose short term prednisolone in healthy subjects. Further longitudinal studies in untreated patients are needed to investigate the endocrine-immune interplay and its consequences during the course of SLE.

The importance of social comparisons for high levels of subjective quality of life in chronic schizophrenic patients.

In schizophrenic patients, quality of life (QoL) studies often find high levels of general life satisfaction and satisfaction in various life domains despite deprived living conditions. Therefore, the usefulness of QoL as an outcome indicator has been questioned. Since social comparison processes have been postulated to be related to the level of satisfaction, this hypothesis was analysed empirically by the present study in schizophrenic patients. Satisfaction and social comparisons of 148 schizophrenic inpatients and 66 mentally healthy controls were examined with regard to the domains 'health' and 'family' by means of a standardised interview. The schizophrenic patients had a history of either long-term (n = 75) or short-term (n = 73) restricted and deprived living conditions. Long-term patients showed significantly higher satisfaction levels than short-term patients. They compared themselves predominantly laterally or downwards with fellow inpatients. Significant relationships between the direction of social comparisons and satisfaction ratings were found in all three samples. Social comparisons proved to be important for the level of satisfaction in schizophrenic patients. Results indicate that experiences of restricted and deprived living conditions induce accommodation processes and response-shifts that should be taken into account in the interpretation of quality-of-life data.

Skin and mucosal lesions associated with cyclosporin A therapy: report of a case.

A 16-year-old boy developed bullous lesions on fingers, ears, tongue, and buccal mucosa as well as cauliflower-like growths on the epiglottis and vocal cords 1 1/2 years after a second renal transplantation and exposure to sunlight while receiving cyclosporin A (CsA). Withdrawal of CsA was followed by complete resolution of skin and mucosal lesions. A predisposition for adverse reactions to CsA is suggested, as additional side effects of CsA therapy were also present.

[Light microscopic demonstration of lectin receptors on the surface of human spermatozoa]. / Lichtmikroskopischer Nachweis von Lektin-Rezeptoren an der Oberfläche humaner Spermatozoen.

The topography of lectin binding sites on human spermatozoa has been examined by using particular series of peroxydase labeled lectin-konjugates (GS-1, GS-2, WGA, PNA, SBA, DBA, BPA, MPA, UEA-1, LPA, Con-A) which demonstrated typical patterns of lectin-receptor distributions concerning acrosomal and equatorial as well as postacrosomal areas.

[Goltz-Gorlin syndrome in a male]. / Goltz-Gorlin-Syndrom bei einem Mann.

Poikilodermal abnormalities with a linear or reticular distribution pattern and associated with other ectodermal and mesodermal disorders are characteristic features of Goltz-Gorlin syndrome (focal dermal hypoplasia), which is found mainly in females. In the light of recent literature a report is given about clinical aspects, histology, differential diagnosis, etiology, and especially the genetics of Goltz-Gorlin syndrome. Because of its rare incidence in males, a case of Goltz-Gorlin syndrome in a 21-year-old man is presented.

Classification and differential diagnosis of 20 problem cases of occidental malignant T-cell lymphomas.

Twenty malignant T-cell lymphomas are described in which the initial histological diagnosis was equivocal. Among lymphoma entities initially falsely interpreted on pure morphological grounds were Hodgkin's disease, lymphoepithelioid cellular lymphoma, immunoblastic lymphoma with epithelioid cells, malignant histiocytosis, histiocytosis X, centroblastic lymphoma, undifferentiated carcinoma, and undifferentiated tumour. Variations in the expected mean survival of initially diagnosed tumours and T-cell lymphomas confirm the need for immunohistological cell typing in lymphoma classification.

Bone marrow mast cell reaction in preleukaemic myelodysplasia and in aplastic anaemia.

The relationship of bone marrow mast cell counts to prognosis was investigated in 48 patients with preleukaemic myelodysplasia, in 59 patients with aplastic anemia and in a DMBA induced myelodysplasia/leukaemia rat model. In patients with myelodysplasia terminating in overt leukaemia the number of mast cells per square millimeter was not correlated to duration of the preleukaemic course. Leukaemia development probabilities of patients at risk were not different for low and elevated mast cell counts. In aplastic anaemia, however, a lower bone marrow mast cell count was related to a higher survival probability and longer survival time. In the animal model no significant differences could be found between myelodysplastic, leukaemic, and control animals.

Eosinophilic differentiation of the human promyelocytic leukemia cell line, HL-60.

HL-60 promyelocytic leukemia cells differentiated to eosinophils and eosinophilic precursors when cultured under mildly alkaline conditions (pH 7.6-7.8) for 7 d without refeeding. New cytoplasmic granules appeared blue in the least mature cells and red in the most mature cells when stained with Wright-Giemsa. The granules also stained with Luxol-fast-blue, a characteristic of eosinophil granules. Furthermore, most cells contained the eosinophil major basic protein (MBP); the Charcot-Leyden Crystal (CLC) protein (lysophospholipase), eosinophil peroxidase, acid phosphatase, and arylsulfatase were also detected in a portion of these cells. The eosinophil major basic protein was found in a high proportion of undifferentiated cells, and thus may be constituitively produced. By examining finely banded chromosomes, translocation break points were demonstrated at q22 on one chromosome 16 and at q23 on the other homologue; abnormalities in this region of the long arm of 16 are a characteristic finding in the recently described syndrome of acute myelomonocytic leukemia (AMMoL) with abnormal bone marrow eosinophils. In common with the bone marrow eosinophils in these patients, the HL-60 eosinophil granules contained chloroacetate esterase and periodic-acid Schiff (PAS) reactive material; crystalloid inclusions were rare. Therefore, the HL-60 cell line appears to be an in vitro model for eosinophilopoiesis and may be specially suited for the study of the abnormal eosinophils seen in certain malignant conditions.

Cotransfer of two linked human genes into cultured mouse cells.

Two linked human genes which code for the expression of cytosol thymidine kinase (ATP:thymidine 5'-phosphotransferase, EC 2.7.1.75) and galactokinase (ATP:D-galactose 1-phosphotransferase, EC 2.7.1.6) have been cotransferred via purified metaphase chromosomes from the human lymphoblastoid cell line WI-L2a, into mouse L-cells [B82 and LM(TK-)]. Both genes have previously been shown to be closely linked on the human chromosome E17, band q21-22. Coexpression of both human enzyme markers was detected in two out of eight gene transfer clones, whilst the remaining six clones contained only human cytosol thymidine kinase, as shown by electrophoretic techniques. A further 23 human enzyme markers corresponding to 15 different human chromosomes were found to be absent in these gene transfer clones. No human chromosome or chromosomal fragment could be detected by karyotype analyses. Some of the gene transfer clones rapidly lost the transferred donor material when grown in nonselective medium, whereas others expressed a stable phenotype under these conditions. Prolonged maintenance in selective medium favors the survival of gene transfer cells expressing a stable phenotype. Possibly these cells harbor the donor genes integrated into a recipient chromosome.