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Radiofrequency radiation-induced calcium ion efflux enhancement from human and other neuroblastoma cells in culture.

To test the generality of radiofrequency radiation-induced changes in 45Ca2+ efflux from avian and feline brain tissues, human neuroblastoma cells were exposed to electromagnetic radiation at 147 MHz, amplitude-modulated (AM) at 16 Hz, at specific absorption rates (SAR) of 0.1, 0.05, 0.01, 0.005, 0.001, and 0.0005 W/kg. Significant 45Ca2+ efflux was obtained at SAR values of 0.05 and 0.005 W/kg. Enhanced efflux at 0.05 W/kg peaked at the 13-16 Hz and at the 57.5-60 Hz modulation ranges. A Chinese hamster-mouse hybrid neuroblastoma was also shown to exhibit enhanced radiation-induced 45Ca2+ efflux at an SAR of 0.05 W/kg, using 147 MHz, AM at 16 Hz. These results confirm that amplitude-modulated radiofrequency radiation can induce responses in cells of nervous tissue origin from widely different animal species, including humans. The results are also consistent with the reports of similar findings in avian and feline brain tissues and indicate the general nature of the phenomenon.

Animals↗

The use of nonneuronal cells for gene delivery.

The implantation of genetically engineered nonneuronal cells can provide an effective method for achieving localized delivery of discrete molecules to the CNS or for providing substrates for regrowth of neural structures. Most primary nonneuronal cells have the advantage of being easily obtainable from the prospective host for ex vivo retrovirus-mediated genetic manipulation (most will be mitotic in culture) and reimplantation as an autologous graft (circumventing the problem of immune rejection). As primary cells, they are unlikely to be tumorigenic. The most vexing problem for such systems remains the apparent loss of transgene expression from viral promoters after prolonged periods of engraftment. Much effort is currently being directed at optimizing sustained transgene expression by varying the promoters, by varying the cell types to be engineered, or by regulating expression by enhancing promoter function or substrate availability. While nonneuronal cells are excellent vehicles for achieving passive delivery of substances to the CNS, they lack the ability to incorporate into the host cytoarchitecture in a functional manner (e.g., make synaptic contacts). For this reason, not only may certain essential circuits not be re-formed, but the regulated release of certain substances through feedback loops may be missing. While apparently unimportant for some substances (e.g., ACh), for others (e.g., NGF), their unregulated, inappropriate, excessive, or ectopic release may actually be inimical to the host. Furthermore, the loss of foreign gene expression (the bane of gene therapy) may leave engineered nonneural cells incapacitated, whereas donor tissue originating from brain may intrinsically produce various CNS factors allowing correction to proceed despite inactivation of the introduced gene. In fact, CNS-derived tissue may provide as-yet-unrecognized endogenous neuralspecific substances which are equally as beneficial to the host as the gene in question. Thus, future developments in gene delivery to the brain for some conditions may emphasize using neurons or neural progenitors for ex vivo genetic manipulation (Fisher, 1997) and refining techniques for the direct injection of therapeutic genes into neurons in vivo (see Snyder and Fisher, 1996). For a wide variety of conditions, however, using nonneuronal cellular vehicles or even nonbiologic synthetic vehicles may be efficient, effective, and safe strategies for the passive delivery of therapeutic molecules to discrete regions of the CNS. In fact, this approach may come closer than any other to immediate human applications.

Animals↗

Endobain E, a brain endogenous factor, is present and modulates NMDA receptor in ischemic conditions.

We have isolated from rat cerebral cortex an endogenous Na(+), K(+)-ATPase inhibitor, termed endobain E, which modulates glutamatergic N-methyl-d-aspartate (NMDA) receptor. This endogenous factor allosterically decreases [(3)H]dizocilpine binding to NMDA receptor, most likely acting as a weak channel blocker. In the present study we investigated whether endobain E is present in the cerebral cortex of rats subjected to ischemia and modulates NMDA receptor exposed to the same conditions. Ischemia-reperfusion was carried out by bilateral occlusion of common carotid arteries followed by a 15-min reperfusion period. Elution profile of brain soluble fraction showed that endobain E is present in cerebral cortex of ischemia-reperfusion rats. On assaying its effect on synaptosomal membrane Na(+), K(+)-ATPase activity and [(3)H]dizocilpine binding to cerebral cortex membranes prepared from animals without treatment, it was found that the endogenous modulator isolated from ischemia-reperfusion rats was able to inhibit both enzyme activity and ligand binding. On the other hand, endobain E prepared from rats without treatment also decreased binding to cerebral cortex or hippocampal membranes obtained from animals exposed to ischemia-reperfusion. Since ischemia decreases tissue pH and NMDA receptor activity varies according to proton concentration, pH influence on endobain E effect was tested. Endobain E ( approximately 80 mg original tissue) decreased [(3)H]dizocilpine binding 25% at pH 7.4 or 8.0 but 90% at pH 6.5. These results demonstrate that endobain E is present and also able to modulate NMDA receptor in the short-term period that follows cerebral ischemia and that its effect depends on proton concentration, suggesting greater NMDA receptor modulation by endobain E at low pH, typical of ischemic tissues.

Animals↗

A primitive neuroectodermal tumor on the face: case report.

In 1918, Stout defined the lesion in which small round cells originating from the ulnar nerve formed a rosette as neuroepithelioma. It was claimed that this tumor originated from neuroectodermis and was different from the classical neuroblastoma. The term primitive neuroectodermal tumor (PNET) involves a group of tumors of the soft tissue originating from neural crest and resulting from the brain, spinal cord and branches of the sympathetic nervous system. Extracranial primitive neuroectodermal tumors originate from neural crest cells outside the sympathetic and central nervous system. PNET also has some distinctive histological, immunohistochemical and ultrastructural features. It is usually encountered in children and young adults; most frequently located in thoracopulmonary region (Askin's tumor). The second most commonly involved body part is the extremities. It is very rarely located on the face. PNET is an aggressive tumor. In fact, the disease has a rapid progression, causes local or distant metastases and 50% of the patients die within two years of the presentation. It is treated with aggressive surgery as well as chemotherapy and radiotherapy. In this report, we presented a case of PNET located on the right cheek with multiple distant metastases. Clinicians should be on alert when treating facial tumors, not to skip PNET, which is a very aggressive one.

Aged↗

Accessory tissue of the tricuspid valve protruding into the left ventricle through a septal defect.

We report the pathologic findings in 13 cases with accessory tissue originating from the tricuspid valve and protruding into the left ventricular outflow tract through a ventricular septal defect (VSD). In eight cases the accessory tissue formed a pouch, the walls of which were similar to the tissue of the normal tricuspid valve. In five cases, papillarylike masses of young connective tissue formed the accessory tissue. The degree of left ventricular outflow tract obstruction was mild in five cases, intermediate in five, and severe in three. Adhesions to the rims of the VSD causing obstruction of the VSD were seen in ten cases. Associated anomalies were present in all cases. The most frequent associated anomalies other than the tricuspid valvular anomalies and the VSDs were transposition of the great arteries and a variety of vascular anomalies.

Child, Preschool↗

Distinctive patterns of GABAA receptor subunit mRNAs in 13 cell lines.

We have investigated the GABAA receptor mRNA composition in 13 cell lines, using 13 subunit-specific oligo-primers (alpha 1-6, beta 1-3, gamma 1-3, and delta) and reverse transcriptase PCR amplification. Cell lines (B35, B65, B103, B104, RINm5F, Rat1, PC12, C6, C17, C27, beta TC3, NB41A3, AtT-20), derived from diverse tissue origins, were investigated in order to identify homogeneous cellular sources with distinctive GABAA receptor subunits. Fifteen GABAA receptor subunits have been cloned from mammalian tissue (those listed above plus the retinal subunits rho 1 and rho 2). This multiplicity of GABAA receptor subunits underlies the diverse pharmacology of the GABAA receptor. Attempts to understand the regulation and pharmacology of individual subunits and of the heterooligomeric receptor combinations have been impeded by a lack of pure populations of cells expressing GABAA receptor subunits. Permanent cell lines provide such a resource. Each GABAA receptor subunit mRNA, alpha 1-5, beta 1-3, gamma 1-3, and delta, was detected in at least one cell line. All cell lines examined contained detectable levels of at least one GABAA receptor subunit mRNA. Each cell line contained distinctive combinations of subunit mRNAs. None of the cell lines examined contained detectable amounts of alpha 6 mRNA. These cell lines, which transcribe GABAA receptor subunit mRNAs, provide useful cellular sources for transcriptional and pharmacological studies. Our data also suggest that endogenous GABAA receptor subunit mRNAs may be present in cells that are routinely used for transfection studies, and that this expression might confound interpretation of the studies. In the following companion article, we have looked for functional GABAA receptor Cl- ion channels in these cell lines, using the patch-clamp technique (Hales and Tyndale, 1994).

Animals↗

Distribution of steroid hormone receptors in human soft tissue sarcomas.

Sixty-six human soft-tissue sarcoma specimens were assayed for incidence and distribution of steroid hormone receptors. Liposarcomas (43%) and leiomyosarcomas (60%) had a high incidence of estrogen receptor. In contrast, sarcomas of fibrous and synovial tissue origin lacked any detectable receptor for estrogen. Malignant fibrous histiocytoma had the highest incidence of glucocorticoid (66%) and androgen (66%) receptors. The incidence of receptors for estrogen and glucocorticoid was higher in female than in male patients (62% and 38%, respectively). Sucrose density gradients demonstrated 8s-type receptors for both estrogen and glucocorticoid. Data from this study suggest that specific high-affinity cytosolic receptors for steroid hormones are present in human soft tissue sarcoma and that their distribution may depend on the histogenetic origin and the sex of patients.

Adolescent↗

[Biological internal fixation -- guidelines for the rehabilitation].

The process of fracture healing restores the biological and mechanical state of the bone tissue. In contrast to other tissues, bone has the unique capacity to heal through a real repair process resulting not in a scar but in a regular reconstitution of its original tissue structure. During the last two decades, the understanding of bone biology continuously evolved leading to the new concept that preservation of the viability of the bone fragments is the key to unimpaired fracture healing. The biological fracture management provides environmental conditions that allow the natural healing process to occur as quickly and undisturbed as possible. In comminuted diaphyseal and metaphyseal fractures, the reduction process strives for restoration of proper length and axial and torsional alignment. Thereby, the reduction technique is mainly indirect, i.e. without direct visualization of the fracture area. The primary stability of an osteosynthesis seems to be of secondary importance for achieving sound bone healing. Stabilization can either be performed with an intramedullary nail or a bridging plate. The new biological plating technique imitates the concept of intramedullary fixation. It requires the use of a long implant working with improved leverage. This reduces both, the loading of the screws and the loading of the plate. The good healing capacity of viable fragments and their integration into the fracture callus protects the implant (especially a plate) from fatigue failure. To help to accomplish this new concept of biological plate fixation, new implants such as the Locking Compression Plate (LCP) have been introduced. The mechanical efficiency of this new plate generation is enhanced due to its possibility for angular stability screw insertion; load transfer by friction can be replaced by a load transfer by interlocking (internal fixator), reducing the biological interference of this implant (no contact implant). Functional rehabilitation with painfree mobilization needs to be performed carefully because the loading capacity of the biological plate osteosynthesis is low until radiological signs of bone healing via callus formation is visible. Clinical signs of overload and radiological indicators of potential mechanical failure of the fixation have to be identified by the general practitioners, and the compliance of the patient has to be controlled during the rehabilitation phase to avoid complications after biological internal fixation.

Bone Plates↗

Cell type-specific expression of the Kv3.1 gene is mediated by a negative element in the 5' untranslated region of the Kv3.1 promoter.

The Kv3.1 potassium channel gene is restrictively expressed in the CNS, and its expression level is especially high in neurons that are able to follow synaptic inputs at high frequencies. To understand the transcriptional mechanisms controlling Kv3.1 expression, we have conducted a functional analysis of the Kv3.1 promoter in various cell lines of different tissue origins and in transgenic mice. Our results suggest that an upstream regulatory fragment coupled with the 5' untranslated region (UTR) is able to confer tissue-specific expression in both cell lines and in transgenic mice. Deletion analysis of the regulatory region carried out in cell lines reveals that a strong negatively acting element, uniquely residing in the 5' UTR (+350 to +158), appears able to confer cell type specificity on both the Kv3.1 promoter and the thymidine kinase promoter in transient transfection assays. A weak cell type-specific enhancer in the proximal region of the promoter (-123 to -71) also contributes to cell type-specific expression of the Kv3.1 gene.

3T3 Cells↗

Amputation and phantom limb pain: a pain-prevention model.

Within the figure of more than 200,000 surgical amputations performed in the United States each year lies another--70% of patients experience phantom limb pain after the procedure, and 50% still experience phantom pain 5 years after surgery. Patients describe burning, stabbing, twisting, cramping, or throbbing pains in the missing part. Adding to the patient's and the anesthesia professional's conundrum has been the lack of a simple model that tissue injury produces pain. The patient with a surgical amputation who experiences phantom limb pain can have several sources for discomfort including problems from the original tissue injury or from pathology, e.g., scarring or continued cellular dysfunction resulting from diabetes, ischemia, or infection. Suboptimal prosthesis fit and tissues and joints connected to the affected part can continue to generate pain long after surgical wound healing. In addition, nonaffected tissues and joints now made to carry extra loads as a result of altered gait and balance can sustain collateral stress and damage and produce nociception. In addition to this series of problems, amputee patients remain susceptible to the pain problems experienced by the general population. There is a positive correlation between a painful limb before amputation and experiencing chronic phantom limb pain. Authors have described patients with preamputation pain who benefited from effective preemptive analgesia and experienced less phantom limb pain. CRNAs can have a significant role in providing anesthesia and analgesia services to these patients and can begin to think in terms of preventing lifelong pain.

Algorithms↗

The relative levels of cyclin D1a and D1b alternative transcripts in mantle cell lymphoma may depend more on sample origin than on CCND1 polymorphism.

The relative levels of cyclin D1 (CCND1) (a) and (b) transcripts were determined by real-time reverse transcription polymerase chain reaction (RT-PCR) and found to vary according to the tissue origin in both control and tumor samples. A five-fold overexpression of both isoforms was observed in 28/38 cases of mantle cell lymphoma (MCL) and of only one isoform in 10/38 MCL. No correlation was observed between expression of cyclin D1 isoforms and CCND1 genotype at position 870.

Alternative Splicing↗

Mesenchymal tissue of the interventricular septum. Structural and ultrastructural study.

Light and electron microscopic studies of frontal and sagittal sections of embryonic chick hearts (Stages 25, 28-29), reveal mesenchymal tissue in the cephalic portion of the interventricular septum. The endocardium of this cephalic portion contains reoriented and invaginated cells with pseudopodia; in addition there are cells immediately subjacent to the endocardium. Similar cellular events take place during the formation of mesenchymal tissue in the atrioventricular and conotruncal regions. In these regions the mesenchymal tissue originates by means of an endocardial activation process. The structural characteristics of the formation of the cephalic portion of the interventricular septum suggest that local mesenchymal tissue is contributed by the endocardium. However, based upon the close anatomic relationship observed by us between the mesenchymal tissues of the atrioventricular canal, conotruncal region and the cephalic portion of the interventricular septum; we do not discard a contribution by migration of cells from atrioventricular and conotruncal regions to the interventricular septum.

Animals↗

Membrane bilayer instability and the pathogenesis of disorders of myelin.

We have previously shown that total lipid extracts from normal nervous tissues spontaneously form a structure in vitro resembling the cell membrane bilayer, but only at a critical temperature, T*, equal to the 'physiological' temperature of the original tissues. In the present study, we found T* for normal human myelin lipids was 37 degrees C, in agreement with the concept that lipid metabolic pools maintain a critical composition in vivo which permits spontaneous formation of the (myelin) membrane bilayer at normal body temperature. But T* for myelin lipids from a patient with metachromatic leukodystrophy was less than 30 degrees C. Thus, myelin lipid composition was inappropriate for normal bilayer stability at this patient's core temperature, suggesting a mechanism whereby defective lipid metabolism in this disease could produce pathological myelin. The shift in T* in this patient was unlikely to be simply secondary to myelin destruction, as myelin lipids from a patient with advanced multiple sclerosis yielded a normal value for T* of 37 degrees C, even when extracted from areas of extensive demyelination.

Adult↗

Isolated extracellular matrix-based three-dimensional in vitro models to study orthotopically cancer cell infiltration and invasion.

An initial event in colon cancer progression is the migration of epithelial cells through the basement membrane (BM) and the invasion of the colon submucosa, where tumour cells enter blood and lymph vessels to spread throughout the body. To interrupt this process would mean the prevention of metastasis. In order to investigate tumour cell invasion orthotopically in the human system, we established novel in vitro models which mimic normal human colon tissue (colon reproductions, CoRes) and primary colon carcinomas (artificial tumours, ArTs). These models are based on the isolated extracellular matrix (iECM) of the respective human tissues. Two isolation methods were established, the Digestion Method and the Lysis Method neither of which destroyed the characteristic architecture of the ECM found in the original tissues. BM components, i.e. laminin, fibronectin and collagen IV, were detectable in the iECM isolated with the Lysis Method but not those isolated with the Digestion Method. Scanning electron microscopic analysis of the normal colon iECM demonstrated that even if the BM was missing, the luminal surface consisted of densely packed ECM filaments which do not allow cell infiltration without degradation of the iECM. Furthermore, we demonstrated that iECM can be separately supplemented with different cell types, i.e. colorectal carcinoma cells, normal fibroblasts and immune cells at any desired concentration, combination and localisation. Therefore, these models could be used to determine the role of the BM and of the tumour cell/normal cell crosstalk in the infiltration process of human colorectal carcinoma cells.

Basement Membrane↗

Selective endothelial binding of interleukin-2-dependent human T-cell lines derived from different tissues.

The ability of lymphocytes to recognize and bind to high endothelial venules (HEVs) is essential for lymphocyte migration from the blood into lymphoid tissues and into sites of inflammation. Endothelial cell binding capacity also critically determines the clinical usefulness of T-cell lines and clones in immunotherapy. In the present study, interleukin-2-dependent T-cell lines were derived from the blood, lamina propria of the gut, inflamed synovium, synovial fluid, and peripheral lymph nodes. After 3-8 weeks of culture, the expression of homing-associated molecules and binding to mucosal, synovial, and peripheral lymph node HEVs were analyzed. Cell lines derived from the blood and mucosal sites bound significantly better to mucosal and synovial HEVs than to peripheral lymph node HEVs. Three out of seven synovial T-cell lines showed preferential binding to synovial HEVs, whereas the rest bound almost equally well to synovial and mucosal HEVs. T-cell lines from peripheral lymph nodes bound preferentially to lymph node HEVs despite the lack of L-selectin (the peripheral lymph node homing receptor). Expression of the known homing-associated molecules did not predict the HEV-binding specificity of these lines. Importantly, two cell lines bound well to synovial venules, but poorly, if at all, to mucosal or peripheral lymph node HEVs, supporting the concept that synovial-specific HEV recognition mechanisms exist. In conclusion, the tissue origin of T-cell lines critically determines their selectivity for endothelial cell recognition, and besides the known "homing receptors," other molecules may also mediate tissue-specific HEV-binding of interleukin-2-activated T cells.

Antigens, CD↗

Establishment in severe combined immunodeficiency mice of subrenal capsule xenografts and transplantable tumor lines from a variety of primary human lung cancers: potential models for studying tumor progression-related changes.

PURPOSE: Lung cancer is a biologically diverse disease and relevant models reflecting its diversity would facilitate the improvement of existing therapies. With a view to establishing such models, we developed and evaluated xenografts of a variety of human lung cancers. EXPERIMENTAL DESIGN: Using nonobese diabetic/severe combined immunodeficiency mice, subrenal capsule xenografts were generated from primary lung cancer tissue, including moderately and poorly differentiated squamous cell carcinoma, adenocarcinoma, adenosquamous carcinoma, small cell carcinoma, large cell undifferentiated carcinoma, and carcinosarcoma. After 4 to 12 weeks, xenografts were harvested for serial transplantation and comparison with the original tissue via histologic, chromosomal, and cytogenetic analyses. RESULTS: Xenografts were successfully established. H&E staining showed that xenografts retained major histologic features of the original cancers. Immunohistochemistry and fluorescence in situ hybridization confirmed the human origin of the tumor cells and development in xenografts of murine supportive stroma. Four transplantable lines were developed from rapidly growing tumors (>5 generations), i.e., a small cell lung carcinoma, large cell undifferentiated carcinoma, pulmonary carcinosarcoma, and squamous cell carcinoma. Analyses including spectral karyotyping, comparative genomic hybridization, and fluorescence in situ hybridization, revealed that the xenografts were genetically similar to the original tumors, showing chromosomal abnormalities consistent with karyotypic changes reported for lung cancer. CONCLUSIONS: The subrenal capsule xenograft approach essentially provides a living tumor bank derived from patient material and a means for isolating and expanding specific cell populations. The transplantable tumor lines seem to provide good models for studying various aspects of tumor progression and a platform for developing novel therapeutic regimens, with the possibility of patient-tailored therapies.

Aged↗

Magnetic characterisation of rat muscle tissues after subcutaneous iron dextran injection.

Ex vivo freeze-dried rat muscle tissues, collected at different times t after a single dose of subcutaneously injected iron dextran, have been magnetically characterised. The AC susceptibility of the tissues shows an overall superparamagnetic behaviour and the dependence on t of, especially, the out-of-phase component is remarkably systematic despite the fact that each tissue originates in a different rat individual. The experiments show that the akaganéite (beta-FeOOH) nanoparticles contained in the injected drug are progressively degraded in the living tissue and, at times of the order of 1 month and for all the analysed rat individuals, converge to a magnetically well-defined species with much narrower magnetic activation energy distribution than iron dextran. Thorough transmission electron microscopy experiments of the same tissues indicate the presence of oxyhydroxide particles, whose size decreases for increasing t in agreement with the interpretation of the magnetic susceptibility. The conclusions drawn from the magnetic study do well correspond to the properties of the whole tissue since no biochemical extraction work has been done. The AC susceptibility appears to be a valuable and complementary tool in pharmacological studies of iron-containing drugs.

Animals↗

Expression of intercellular adhesion molecule-1 on human thyroid cells from patients with autoimmune thyroid disease: study of thyroid xenografts in nude and severe combined immunodeficient mice and treatment with FK-506.

It has been suggested that intercellular adhesion molecule-1 (ICAM-1) may play an important role in the initiation, localization, and perpetuation of autoimmune thyroid diseases (AITD). In an effort to clarify its role, we have investigated the expression of ICAM-1 on thyroid epithelial cells (TEC) of patients with AITD, patients with nontoxic goiter (NTG), and normal subjects (PN) by flow cytometric analysis under basal conditions and after modulation with cytokines, before and after 8 weeks of thyroid tissue xenotransplantation in nude athymic mice (which lyses all passenger lymphocytes), and in severe combined immunodeficient (SCID) mice where these cells survive. Before xenografting, ICAM-1 was expressed on 56% of TEC from Hashimoto's thyroiditis (n = 5), 54% of Graves' disease (n = 6), 15% of NTG (n = 5), and 12% of PN TEC. After the xenografts had been 8 weeks in nude mice, ICAM-1 expression decreased markedly in AITD TEC [from 56% to 10% in Hashimoto's thyroiditis (P < 0.001) and from 54% to 8% in Graves' disease (P < 0.01)], but did not change significantly in NTG or PN. After the xenografts had been 8 weeks in SCID mice, the expression of ICAM-1 was significantly higher on TEC of AITD compared with the same tissue in nude mice. When the SCID mice engrafted with AITD tissue were treated with the anti-CD4+ T (helper) cell agent FK-506, the expression of ICAM-1 was reduced significantly compared with that in the original tissue or that in nontreated mice engrafted with the same tissue. The proportion of TEC that were ICAM-1 positive was up-regulated in all cases by certain cytokines (e.g. interferon-gamma and tumor necrosis factor-alpha applied alone or in combination). We also detected the presence of ICAM-1 in AITD frozen tissues using an immunohistochemical technique. These data suggest a role for ICAM-1 in human AITD. However, the expression of ICAM-1 appears to be a secondary phenomenon in response to the immune assault, rather than a primary event. Our results support the idea that TEC may act as passive captives to immunological events in human AITD.

Animals↗