Subependymal Giant Cell Astrocytoma Size Measurement in Tuberous Sclerosis Complex: Noncontrast vs Contrast-Enhanced 3-Dimensional T1-Weighted Magnetic Resonance Imaging (MRI)

PURPOSE

Tuberous sclerosis complex is a multisystem genetic disorder characterized by multiorgan hamartomas, seizures, and developmental delay. Current consensus recommendations for tuberous sclerosis complex include brain magnetic resonance imaging (MRI) without and with contrast every 1 to 3 years until age 25 years for subependymal giant cell astrocytoma screening, and more often in patients with known subependymal giant cell astrocytoma. Recent reports in the literature regarding gadolinium deposition have prompted us to investigate the added value of intravenous contrast in this setting.

MATERIALS AND METHODS

Thirty-nine MRI examinations from 12 tuberous sclerosis complex patients with known subependymal giant cell astrocytoma were retrospectively reviewed for all caudothalamic groove lesions larger than 1 cm. Lesions were measured in 2 planes on both noncontrast and contrast-enhanced axial 3-dimensional (3D) T1-weighted imaging in a randomized fashion by 2 attending pediatric neuroradiologists. Differences in lesion measurements were compared to zero using a 1-sample t test.

RESULTS

On average, radiologist A measured lesions 1.1 mm larger in long-axis diameter without contrast (P = .0003), whereas radiologist B measured lesions 0.1 mm larger without contrast (not significant). Differences in lesion measurement were smaller when comparing noncontrast to contrast-enhanced 3D T1-weighted imaging than when comparing radiologist A to radiologist B.

CONCLUSIONS

Noncontrast axial 3D T1-weighted imaging is similar to contrast-enhanced axial 3D T1-weighted imaging for subependymal giant cell astrocytoma size measurement. It has high accuracy and may be a safer and more efficient imaging method for tuberous sclerosis complex patients who commonly undergo numerous MRI examinations throughout their lifetime. Further studies may be appropriate to determine whether contrast material could be beneficial in certain situations.

Predicting Pharmacist Dispensing Practices and Comfort Related to Pre-exposure Prophylaxis for HIV Prevention (PrEP)

To identify factors associated with pharmacist dispensing practice and comfort counseling patients about pre-exposure prophylaxis for HIV prevention (PrEP). Cross-sectional 2016 census of Indiana managing pharmacists measured PrEP awareness, comfort dispensing and counseling patients. Modified Poisson models with robust error variance estimated relative risks and confidence intervals. 15.8% of 284 pharmacists had dispensed PrEP and 11.6% had consulted about it. Dispensing and comfort counseling were associated with confidence in knowledge about PrEP medication adherence and adverse effects of PrEP medication; awareness about PrEP before the survey, number of full time pharmacists in their pharmacy, and increases in new HIV cases from 2015 to 2016 in communities served. Comfort counseling about PrEP was associated with the belief that pharmacists can be an important resource for HIV and HCV treatment.

Gadolinium DTPA Enhancement Characteristics of the Rat Sciatic Nerve after Crush Injury at 4.7T

BACKGROUND AND PURPOSE

Traumatic peripheral nerve injury is common and results in loss of function and/or neuropathic pain. MR neurography is a well-established technique for evaluating peripheral nerve anatomy and pathology. However, the Gd-DTPA enhancement characteristics of acutely injured peripheral nerves have not been fully examined. This study was performed to determine whether acutely crushed rat sciatic nerves demonstrate Gd-DTPA enhancement and, if so, to evaluate whether enhancement is affected by crush severity.

MATERIALS AND METHODS

In 26 rats, the sciatic nerve was crushed with either surgical forceps (6- to 20-N compressive force) or a microvascular/microaneurysm clip (0.1-0.6 N). Animals were longitudinally imaged at 4.7T for up to 30 days after injury. T1WI, T2WI, and T1WI with Gd-DTPA were performed.

RESULTS

Forceps crush injury caused robust enhancement between days 3 and 21, while clip crush injury resulted in minimal-to-no enhancement. Enhancement after forceps injury peaked at 7 days and was seen a few millimeters proximal to, in the region of, and several centimeters distal to the site of crush injury. Enhancement after forceps injury was statistically significant compared with clip injury between days 3 and 7 (P < .04).

CONCLUSIONS

Gd-DTPA enhancement of peripheral nerves may only occur above a certain crush-severity threshold. This phenomenon may explain the intermittent observation of Gd-DTPA enhancement of peripheral nerves after traumatic injury. The observation of enhancement may be useful in judging the severity of injury after nerve trauma.

Ranking freshwater fish farms for the risk of pathogen introduction and spread

A semi-quantitative model is presented to rank freshwater rainbow trout farms within a country or region with regards to the risk of becoming infected and spreading a specified pathogen. The model was developed to support a risk-based surveillance scheme for notifiable salmonid pathogens. Routes of pathogen introduction and spread were identified through a process of expert consultation in a series of workshops. The routes were combined into themes (e.g. exposure via water, mechanical transmission). Themes were weighted based on expert opinion. Risk factors for each route were scored and combined into a theme score which was adjusted by the weight. The number of sources and consignments were used to assess introduction via live fish movements onto the farm. Biosecurity measures were scored to assess introduction on fomites. Upstream farms, wild fish and processing plants were included in assessing the likelihood of introduction by water. The scores for each theme were combined to give separate risk scores for introduction and spread. A matrix was used to combine these to give an overall risk score. A case study for viral haemorrhagic septicaemia is presented. Nine farms that represent a range of farming practices of rainbow trout farms in England and Wales are used as worked examples of the model. The model is suited to risk rank freshwater salmonid farms which are declared free of the pathogen(s) under consideration. The score allocated to a farm does not equate to a quantitative probability estimate of the farm to become infected or spread infection. Nevertheless, the method provides a transparent approach to ranking farms with regards to pathogen transmission risks. The output of the model at a regional or national level allows the allocation of surveillance effort to be risk based. It also provides fish farms with information on how they can reduce their risk score by improving biosecurity. The framework of the model can be applied to different production systems which may have other routes of disease spread. Further work is recommended to validate the allocated scores. Expert opinion was obtained through workshops, where the outputs from groups were single point estimates for relative weights of risks. More formal expert opinion elicitation methods could be used to capture variation in the experts' estimates and uncertainty and would provide data on which to simulate the model stochastically. The model can be downloaded (in Microsoft(®)-Excel format) from the Internet at: http://www.cefas.defra.gov.uk/6701.aspx.

Zinc modulation of glycine receptors

Glycine receptors are widely expressed in the mammalian central nervous system, and previous studies have demonstrated that glycine receptors are modulated by endogenous zinc. Zinc is concentrated in synaptic vesicles in several brain regions but is particularly abundant in the hippocampus and olfactory bulb. In the present study, we used patch-clamp electrophysiology of rat hippocampal and olfactory bulb neurons in primary culture to examine the effects of zinc on glycine receptors. Although glycine has been reported to reach millimolar concentrations during synaptic transmission, most previous studies on the effects of zinc on glycine receptors have used relatively low concentrations of glycine. High concentrations of glycine cause receptor desensitization. Our current results extend our previous demonstration that the modulatory actions of zinc are largely prevented when co-applied with desensitizing concentrations of glycine (300 μM), suggesting that the effects of zinc are dependent on the state of the receptor. In contrast, pre-application of 300 μM zinc, prior to glycine (300 μM) application, causes a slowly developing inhibition with a slow rate of recovery, suggesting that the timing of zinc and glycine release also influences the effects of zinc. Furthermore, previous evidence suggests that synaptically released zinc can gain intracellular access, and we provide the first demonstration that low concentrations of intracellular zinc can potentiate glycine receptors. These results support the notion that zinc has complex effects on glycine receptors and multiple factors may interact to influence the efficacy of glycinergic transmission.

High frequencies of polyfunctional HIV-specific T cells are associated with preservation of mucosal CD4 T cells in bronchoalveolar lavage

The mechanisms underlying the massive gastrointestinal tract CD4 T-cell depletion in human immunodeficiency virus (HIV) infection are not well understood nor is it clear whether similar depletion is manifest at other mucosal surfaces. Studies of T-cell and virus dynamics in different anatomical sites have begun to illuminate the pathogenesis of HIV-associated disease. Here, we studied depletion and HIV infection frequencies of CD4 T cells from the gastrointestinal tract, bronchoalveolar lavage (BAL), and blood with the frequencies and functional profiles of HIV-specific T cells in these anatomically distinct sites in HIV-infected individuals. The major findings to emerge were as follows: (i) depletion of gastrointestinal CD4 T cells is associated with high frequencies of infected CD4 T cells; (ii) HIV-specific T cells are present at low frequencies in the gastrointestinal tract compared to blood; (iii) BAL CD4 T cells are not massively depleted during the chronic phase; (iv) infection frequencies of BAL CD4 T cells are similar to those in blood; (v) significantly higher frequencies and increased functionality of HIV-specific T cells were observed in BAL compared to blood. Taken together, these data suggest mechanisms for mucosal CD4 T-cell depletion and interventions that might circumvent global depletion of mucosal CD4 T cells.

Transplacental passage of non-ionic contrast agents resulting in fetal bowel opacification: a mimic of pneumoperitoneum in the newborn

Although animal studies suggest that non-ionic radiological contrast agents do not cross the placenta, case reports have documented transplacental passage of the non-ionic monomers iohexol and iopromide in humans. We report a case of presumed transplacental passage of the non-ionic monomer ioversol resulting in fetal bowel opacification and mimicking pneumoperitoneum.

Supplemental Value of MRI in Fetal Abdominal Disease Detected on Prenatal Sonography: Preliminary Experience

OBJECTIVE

Our aim was to determine the supplemental value of MRI in fetal abdominal disease detected on prenatal sonography.

CONCLUSION

Our preliminary results suggest the primary supplemental value of MRI relative to sonography in fetal abdominal disease lies in improved tissue characterization rather than in improved anatomic characterization.

The need for effective disease control in international aquaculture

Globally, aquaculture is steadily expanding both in terms of total production and the range of species farmed. At an overall annual growth rate of about 10%, it is by far the fastest growing sector of food animal production in the world and is providing an increasing proportion of the total production of fish and shellfish for human consumption. However, diseases continue to cause significant economic losses in international aquaculture production and to have a detrimental effect on valuable export trade for some countries. Financial losses have been drastic in some cases and the national economies of some developing countries have been adversely affected. Even just at the local level, disease can have a serious impact on the livelihoods and food security of many individual small farmers and their families, particularly in poorer countries. Despite all the problems caused, diseases continue to be spread internationally even where import health safeguards are in place. Recent examples of such spread are presented and some reasons for the appearance of a disease in a country for the first time are given. It is an unfortunate fact that despite many years of damaging economic and social impact of disease in different sectors of aquaculture, and large sums being spent on research around the world, there are relatively few effective and officially approved products available to control or prevent them. Despite the potential market, there are as yet no commercial vaccines available to prevent the damaging effects of many of the most serious diseases. Without such vaccines, it is likely that the serious impact of diseases in international aquaculture will continue for many years to come.

Selection of biomaterials for peripheral nerve regeneration using data from the nerve chamber model

Peripheral nerve regeneration has been studied in a variety of animal models. Of these, the nerve chamber model has clearly dominated. It has been used to generate a large base of data that, however, cannot be analyzed usefully due to lack of standardization of experimental conditions and assays. Lack of standardization of critical experimental parameters of the model has, however, greatly limited the opportunity to compare directly data from independent investigators; as a result, progress in understanding conditions for optimal nerve regeneration has been stunted. In this article, we provide an overview of the major experimental parameters that must be controlled in order to generate data from independent investigators that can be compared directly (normalized data). Such parameters include the gap length, animal species, and the identity of assays used to evaluate the product of the regenerative process. Use of the recently introduced concept of critical axon elongation, the gap length at which the probability of axonal outgrowth (reinnervation) across the gap is 50%, leads to generation of a normalized database that includes data from several independent investigators. Conclusions are drawn about the relative efficacy of the various biomaterials and devices employed. Nerve chamber configurations that had the highest regenerative activity were those in which the tube wall comprised collagen and certain synthetic biodegradable polymers rather than silicone, and was cell-permeable rather than protein-permeable. In addition, the following tube fillings showed very high regenerative activity: suspensions of Schwann cells; a solution either of acidic or basic fibroblast growth factor; insoluble ECM substrates rather than solutions or gels; polyamide filaments oriented along the tube axis; highly porous, insoluble analogs of the ECM with specific structure and controlled degradation rate.

Evidence for increased T cell turnover and decreased thymic output in HIV infection

The effects of HIV infection upon the thymus and peripheral T cell turnover have been implicated in the pathogenesis of AIDS. In this study, we investigated whether decreased thymic output, increased T cell proliferation, or both can occur in HIV infection. We measured peripheral blood levels of TCR rearrangement excision circles (TREC) and parameters of cell proliferation, including Ki67 expression and ex vivo bromodeoxyuridine incorporation in 22 individuals with early untreated HIV disease and in 15 HIV-infected individuals undergoing temporary interruption of therapy. We found an inverse association between increased T cell proliferation with rapid viral recrudescence and a decrease in TREC levels. However, during early HIV infection, we found that CD45RO-CD27high (naive) CD4+ T cell proliferation did not increase, despite a loss of TREC within naive CD4+ T cells. A possible explanation for this is that decreased thymic output occurs in HIV-infected humans. This suggests that the loss of TREC during HIV infection can arise from a combination of increased T cell proliferation and decreased thymic output, and that both mechanisms can contribute to the perturbations in T cell homeostasis that underlie the pathogenesis of AIDS.

Effect of atorvastatin on intracellular calcium uptake in coronary smooth muscle cells from diabetic pigs fed an atherogenic diet

Intracellular Ca(2+) store loading has been shown to alter proliferation and apoptosis of several cell types. In addition, HMG-CoA reductase inhibitors (i.e. atorvastatin) are effective in treating diabetic dyslipidemic patients. Thus, we hypothesized that chronic atorvastatin treatment would prevent increased Ca(2+) uptake into intracellular Ca(2+) stores in vascular smooth muscle cells from diabetic dyslipidemic pigs. Male Yucatan pigs were divided into four groups for 20 weeks-- (1) low fat fed (control); (2) hyperlipidemic (F); (3) alloxan-induced diabetic dyslipidemic (DF); and (4) diabetic dyslipidemic pigs treated with atorvastatin (DFA). The F, DF, and DFA groups were fed a high fat/cholesterol diet. Cells were isolated from the coronary artery and the myoplasmic Ca(2+) (Ca(m)) response measured using single cell fura-2 imaging. The Ca(m) response to caffeine (5 mM to release Ca(2+) from the sarcoplasmic reticulum, SR) and ionomycin (10 microM; to release the total Ca(2+) store) was determined in either the presence of low Na (19Na; inhibits Na(+)-Ca(2+) exchange), thapsigargin (TSG; inhibits the SR Ca(2+) pump), and a 19Na+TSG solution. Low Na induced the uptake of Ca(2+) into both SR and non-SR Ca(2+) stores in the DF group, but not the DFA group. Furthermore, after depletion of the SR Ca(2+) store with TSG, 19Na evoked Ca(2+) uptake into non-SR Ca(2+) stores in all three groups except in the DFA group. In summary, this study demonstrates that atorvastatin prevents the enhanced uptake of Ca(2+) by SR and non-SR Ca(2+) stores in diabetic dyslipidemic pigs.

Functional nucleotide receptor expression and sarcoplasmic reticulum morphology in dedifferentiated porcine coronary smooth muscle cells

The phenotypic dedifferentiation of vascular smooth muscle cells (SMCs) is an early event associated with cell culturing and vascular injury. The purpose of this study was to evaluate the SMC phenotype underlying the functional responsiveness of SMCs to nucleotides in organ culture. Porcine coronary arteries were either used fresh, cold stored (5 degrees C) 4 days, or organ cultured (37 degrees C) 4 days. Fura-2 digital imaging of single SMCs was used to measure the myoplasmic calcium (Ca(m)) response to 10 microM of the following nucleotide receptor agonists: UTP, UDP, ATP, ADP, and 2-MeSATP. In contrast to the nucleotides UDP, ATP, ADP, and 2-MeSATP, the Ca(m) response increased 10-fold and the number of cells that responded to UTP increased 5-fold in SMCs from organ culture compared to SMCs from fresh or cold-stored arteries. Simultaneous imaging of Ca(m), DNA content, and SR distribution in SMCs from organ culture indicated that the UTP-induced Ca(m) increase occurred exclusively in SMCs that had a dedifferentiated cell phenotype. Three-dimensional image reconstruction of the nucleus and sarcoplasmic reticulum (SR) revealed a novel transnuclear SR distribution that intertwined with the nucleus in fresh SMCs, while in SMCs from organ culture the SR was predominantly perinuclear and cytoplasmic. This study demonstrates that the functional up-regulation of UTP-sensitive receptors and the disappearance of the transnuclear SR distribution are novel features of dedifferentiated coronary SMCs.

Traceability of aquatic animals

Effective methods of traceability are urgently required for use in research as well as in different types of aquaculture operations and to control trade in aquatic animals and products. In regard to the marking of fish, many different tagging methods have been described and the method to be used depends on the purpose and need for tagging. In contrast, for molluscs and crustaceans, only a few methods of marking such animals have been described, due to the practical difficulties. The authors first describe the different methods for tracing fish and fishery products, by means of external tags, such as Floy tags, Carlin tags and passive integrated transponder tags; chemical marking using inorganic substances such as silver nitrate or potassium nitrate, pigments, oxytetracycline, etc.; and several different types of electronic devices in which basic information such as the strain of fish, farm of origin or weight can be stored. Genetic traceability using deoxyribonucleic acid profiling is developing quite rapidly for cultured brood stocks and wild populations. This technique may be used with very high degrees of confidence to assign to or exclude animals or products from their claimed origin, paternity or strain, and may be used as evidence in court proceedings. The second section of this paper describes the traceability of live molluscs for restocking and for human consumption. In these applications, genetic markers have been demonstrated to be suitable. Mechanical tagging on a small scale for research purposes has also been used. Otherwise, the only means of tracing live molluscs are the movement documents and the labelling on boxes that certifies the origin of the commodity. The third section describes the methods available for tracing live and dead crustaceans. A large variety of physical tagging methods for decapod crustaceans is described, such as the injection of biological stains (fast green, Niagara sky blue, trypan red and blue) and external tags such as coloured streamer tags, wire tags and a variety of anchor tags. Furthermore, a number of different internal coding methods, such as the coded micro-wire tags and injected elastomer tags are discussed in detail. As is the case for fish, genetic molecular techniques are also applied in population studies of crustaceans; some of the molecular genetic methods are described. Prawns for human consumption are most frequently packed whole or as tails after the necessary sorting, washing and freezing and the only way of performing a traceback is through documents relating to movement, invoices, health certificates and labelling of the boxes. The minimum requirements for labelling would be the content of the packages, i.e. species, quantity, identification of the manufacturer (name and address), packing place, importer/exporter or vendor of the product, in addition to the loading bill number.

Factors affecting thymic function after allogeneic hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is followed by profound immunodeficiency. Thymic function is necessary for de novo generation of T cells after HSCT. Circulating CD45RA(+) naive T-cell levels are predictive of antigen-specific T-cell responses in the absence of graft-versus-host disease (GVHD). These T cells may not represent recent thymic emigrants, since naive T cells may maintain this phenotype if not antigen-activated. To accurately measure thymic output after HSCT and determine the factors that influence thymic function, T-cell receptor excision circles (TRECs) were examined in CD4(+) and CD8(+) cells from a cross-section of patients following HSCT. TREC levels rose weeks after HSCT and could be detected in patients 6 years after HSCT. TREC levels correlated with the frequency of phenotypically naive T cells, indicating that such cells were not expanded progeny of naive T cells present in the donor graft. Chronic GVHD was the most important factor that predicted low TREC levels even years after HSCT. Patients with a history of resolved GVHD had decreased numbers of TREC, compared with those with no GVHD. Because few adults had no history of GVHD, it was not possible to determine whether age alone inversely correlated with TREC levels. Recipients of cord blood grafts had no evidence of decreased TREC induced by immunosuppressive prophylaxis drugs. Compared with unrelated donor grafts, recipients of matched sibling grafts had higher TREC levels. Collectively, these data suggest that thymopoiesis is inhibited by GVHD. Larger studies will be needed to determine the independent contributions of age and preparative regimen to post-transplant thymopoietic capacity.

Enhanced endothelin(A) receptor-mediated calcium mobilization and contraction in organ cultured porcine coronary arteries

Arterial injury models for coronary artery disease have demonstrated an enhanced expression and function of either the endothelin(A) or endothelin(B) (ET(A) or ET(B)) receptor subtype. We hypothesized that organ culture would enhance the physiological function of ET receptors in the porcine right coronary artery. Arteries were either cold stored (4 degrees C) or organ cultured (37 degrees C) for 4 days. After 4 days, the artery was either 1) sectioned into rings to measure the ET-1-induced isometric tension response (3 x 10(-10)-3 x 10(-7) M), or 2) enzymatically dispersed and the isolated smooth muscle cells imaged using fura-2 to measure the myoplasmic calcium (Ca(m)) response to 3 x 10(-8) M ET-1 ( approximately EC(50)). Isometric tension and Ca(m) to ET-1 were measured in the absence and presence of bosentan (nonselective ET(A) or ET(B) receptor antagonist), BQ788 (ET(B)-selective antagonist), and BQ123 (ET(A)-selective antagonist). Compared with cold storage, organ culture induced a 2-fold increase in tension development (3 x 10(-7) M ET-1) and Ca(m) (3 x 10(-8) M ET-1), which was inhibited with bosentan, thus confirming the enhanced responses to ET-1 were due to ET receptor activation. BQ123 also inhibited the enhanced contraction and Ca(m) responses to ET-1. In contrast, BQ788 failed to inhibit tension development and Ca(m) responses to ET-1 in organ culture and cold storage. Sarafotoxin 6C (ET(B) agonist) failed to elicit an increased Ca(m) response in organ culture compared with cold storage. Our results indicate the increased tension development and Ca(m) responses to ET-1 in organ culture are attributable to ET(A) receptors, and not ET(B) receptors.

Assessment of thymic output in adults after haematopoietic stem-cell transplantation and prediction of T-cell reconstitution

BACKGROUND

The potential benefits of haematopoietic stem-cell transplantation are tempered by the depletion of T-cells accompanying this procedure. We used a new technique which quantifies the excisional DNA products of T-cell-receptor (TCR) gene rearrangement to measure thymic output directly in patients with multiple myeloma, and thus assessed the contribution of the thymus to immune recovery after transplantation.

METHODS

We studied 40 patients, 34-66 years of age, who had been randomly assigned myeloablative chemotherapy and autologous peripheral-blood haematopoietic stem-cell transplantation with unmanipulated grafts or grafts enriched for CD34 stem cells. CD4 and CD8 T-cell counts were measured, thymic output was estimated serially until 2 years after transplantation, and percentages of naive T-cells were measured.

FINDINGS

The production of substantial numbers of new naive T cells by the thymus could be detected by 100 days post-transplant; there was a significant inverse relation between age and recovery of new T cells. In the CD34-unselected group, numbers of TCR-rearrangement excision circles returned to baseline after 2 years, whereas in the CD34-selected group, numbers at 2 years were significantly higher than both baseline numbers (p=0.004), and 2-year numbers in the unselected group (p=0.046). Increased thymic output correlated with, and was predictive of, increased naive T-cell numbers and broader T-cell-receptor repertoires.

INTERPRETATION

Our results provide evidence that the adult thymus contributes more substantially to immune reconstitution after haematopoietic stem-cell transplantation than was previously thought, and therefore could be a target for therapeutic intervention.

Probing the extracellular release site of the plasma membrane calcium pump

The plasma membrane Ca(2+) pump is known to mediate Ca(2+)/H(+) exchange. Extracellular protons activated (45)Ca(2+) efflux from human red blood cells with a half-maximal inhibition constant of 2 nM when the intracellular pH was fixed. An increase in pH from 7.2 to 8.2 decreased the IC(50) for extracellular Ca(2+) from approximately 33 to approximately 6 mM. Changing the membrane potential by >54 mV had no effect on the IC(50) for extracellular Ca(2+). This argues against Ca(2+) release through a high-field access channel. Extracellular Ni(2+) inhibited Ca(2+) efflux with an IC(50) of 11 mM. Extracellular Cd(2+) inhibited with an IC(50) of 1. 5 mM, >10 times better than Ca(2+). The Cd(2+) IC(50) also decreased when the pH was raised from 7.1 to 8.2, consistent with Ca(2+), Cd(2+), and H(+) competing for the same site. The higher affinity for inhibition by Ni(2+) and Cd(2+) is consistent with a histidine or cysteine as part of the release site. The cysteine reagent 2-(trimethylammonium)ethyl methanethiosulfonate did not inhibit Ca(2+) efflux. Our results are consistent with the notion that the release site contains a histidine.

Prolonged activation of the mitogen-activated protein kinase pathway is required for macrophage-like differentiation of a human myeloid leukemic cell line

The role of the mitogen-activated protein kinase (MAPK) signal transduction pathway in the proliferation of mammalian cells has been well established. However, there are relatively few reports concerning cell differentiation being mediated by MAPK. The effect of phorbol 12-myristate 13-acetate (PMA) on cell differentiation and signal transduction in a human myeloid leukemia cell line, TF-1a, was investigated. When TF-1a cells were treated with 10(-6), 10(-7), 10(-8), and 10(-9) M PMA for 24 h, they underwent 98, 93, 91, and 51% macrophage-like differentiation, respectively. PMA treatment rapidly (10 min) induced phosphorylation of MAPK kinase (MEK and p44/42 MAPK), which persisted for at least 24 h. p44/42 MAPK immunoprecipitates from lysates of PMA-treated cells had increased ability to phosphorylate the transcription factor Elk-1. This is important because phosphorylated Elk-1 can be considered an "end-product" of the MAPK pathway. In contrast, treatment of TF-1a cells with granulocyte/macrophage-colony stimulating factor induced only transient activation of MEK and p44/42 MAPK (10-20 min) and an increase (approximately 50%) in cell proliferation, without any change in cellular differentiation. These results suggest that macrophage-like differentiation may be dependent on prolonged activation of the MAPK pathway. Additional support for this conclusion was obtained from experiments showing that treatment of TF-1a cells with antisense oligonucleotides for MEK1 coding sequences prior to adding PMA inhibited macrophage-like differentiation. Furthermore, transient transfection with an inactive, dominant-negative MEK mutant also inhibited PMA-induced differentiation, whereas transient transfection with a plasmid coding for constitutively activated MEK led to macrophage-like differentiation in the absence of PMA.

Interactions between GABA and glycine at inhibitory amino acid receptors on rat olfactory bulb neurons

Whole cell voltage-clamp electrophysiology was used to examine interactions between GABA and glycine at inhibitory amino acid receptors on rat olfactory bulb neurons in primary culture. Membrane currents evoked by GABA and glycine were selectively inhibited by low concentrations of bicuculline and strychnine, respectively, suggesting that they activate pharmacologically distinct receptors. However, GABA- and glycine-mediated currents showed cross-inhibition when the two amino acids were applied sequentially. Application of one amino acid inhibited the response to immediate subsequent application of the other. In the majority of neurons, GABA inhibited subsequent glycine-evoked currents and glycine inhibited subsequent GABA-evoked currents. In a small proportion of neurons, however, GABA inhibited glycine-evoked currents but glycine had little effect on GABA-evoked currents. The reverse was true in other neurons, suggesting that alterations in chloride gradients alone did not account for the cross-inhibition. Furthermore, no cross-inhibition was observed between GABA- and glycine-evoked currents in some neurons. The amplitude of the current evoked by the coapplication of saturating concentrations of GABA and glycine in these neurons was nearly the sum of the currents evoked by GABA and glycine alone. In contrast, the currents were not additive in neurons demonstrating cross-inhibition. These results suggest that olfactory bulb neurons heterogeneously express a population of inhibitory amino acid receptors that can bind either GABA or glycine. Interactions between GABA and glycine at inhibitory amino acid receptors may provide a mechanism to modulate inhibitory synaptic transmission.

Successful aquatic animal disease emergency programmes

The authors provide examples of emergency programmes which have been successful in eradicating or controlling certain diseases of aquatic animals. The paper is divided into four parts. The first part describes the initial isolation of viral haemorrhagic septicaemia (VHS) virus in North America in the autumn of 1988 from feral adult chinook (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) returning for spawning. The fish disease control policies at both State and Federal levels in the United States of America required quarantine and emergency eradication measures upon the finding of certain exotic fish pathogens, including VHS virus. The procedures for emergency plans, destruction of stocks and disinfection of facilities are described, as well as challenge experiments with the North American strains of VHS virus and the detection of the virus in marine fish species (cod [Gadus macrocephalus] and herring [Clupea harengus pallasi]) in the Pacific Ocean. The second part of the paper outlines the aquatic animal legislation in Great Britain and within the European Union, in regard to contingency plans, initial investigations, action on the suspicion of notifiable disease and action on confirmation of infection. The legal description is followed by an account of an outbreak of viral haemorrhagic septicaemia in turbot (Scophthalmus maximus) in Great Britain, including the stamping-out process at the affected farm and investigations conducted to screen other farms in the vicinity for possible infection. The third part provides a historical review of the build-up of infectious salmon anaemia (ISA) in Norway and the attempts to control the disease using legal measures in the absence of detailed knowledge of the aetiology, epizootiology, pathogenesis, etc. of the disease. The measures taken show that the spread of ISA can be controlled using restrictions on the movement of fish, disinfection procedures, etc. However, acceptance and understanding of the chosen strategy by the fish farmers is a pre-requisite to reach that goal. Finally, the paper summarises future needs for national and international legislation, including the development of standard approaches for control, the creation of appropriate infrastructures and a better understanding of the epidemiology of aquatic animal diseases.

Characterization of a unique factor-independent variant derived from human factor-dependent TF-1 cells: a transformed event

A factor-independent variant (TF-1a) has been isolated from the factor-dependent TF-1 cell line. The subline has been grown continuously in culture for > 1.5 years without added cytokines. The cells retain the ability to respond to multicytokines, with a different response pattern from its parental cell line. The TF-1 cells appeared singly in liquid culture. In contrast. TF-1a cells formed aggregates which increased markedly in size and in number upon TGFbeta1 treatment and showed a diminished TGFbeta-mediated growth inhibition. TF-1a, but not TF-1 cells, formed colonies in soft agar culture in the absence of any added growth factors, and developed the capacity to generate an invasive tumor(s) in nude mice. There was a constitutive activation of MAPK and MEK in TF-1a but not in TF-1 cells, which may be one of the mechanisms leading to factor-independent growth of TF-1a cells. Phenotypically, TF-1 cells were CD34+ /CD38+, whereas TF-1a cells were CD34+ /CD38-. This suggests that TF-1a may represent a less mature hematopoietic cell than TF-1. In conclusion, TF-1a is different from TF-1 in many important aspects which are associated with neoplastic transformation. The variant appears to be an excellent model for studying the process of progressive malignant transformation of myeloid cells and for studying signal pathways involved in the spontaneous and factor-induced growth of the cells.

Submaximal stimulation of porcine endothelial cells causes focal Ca2+ elevation beneath the cell membrane

1. Endothelial cell activation is correlated with increased cytosolic Ca2+ concentration, often monitored with cytoplasmic Ca2+ dyes, such as fura-2 and Calcium Green-1. We tested the hypothesis that during weak stimulation of porcine coronary artery endothelial cells, focal, subplasmalemmal Ca2+ elevations occur which are controlled by cell membrane Na(+)-Ca2+ exchange near mitochondrial membrane and superficial endoplasmic reticulum (SER). 2. Bulk Ca2+ concentration ([Ca2+]b) was monitored using fura-2 or Calcium Green-1 and subplasmalemmal Ca2+ concentration ([Ca2+]sp) was determined with FFP-18. The distribution of the SER network was estimated using laser scanning and deconvolution microscopy. 3. Sodium fluoride (10 mmol l-1) and submaximal concentrations of bradykinin (Bk; 1 nmol l-1) stimulated Ca2+ entry with no increase in [Ca2+]b. Although inositol 1,4,5-trisphosphate formation and intracellular Ca2+ release in response to both stimuli were similar, Ca2+ entry in response to NaF exceeded that in response to 1 nmol l-1 BK by fourfold, suggesting additional effects of NaF on Ca+ entry pathways but stimulation via intracellular Ca2+ release. 4. Prevention of Na(+)-Ca2+ exchange activity by decreasing extracellular Na+ unmasked intracellular Ca2+ release in response to NaF and 1 nmol l-1 Bk, indicated by an increase in [Ca2+]b. Thereby, NaF depleted Bk-releasable Ca2+ pools, while mitochondrial Ca2+ content (released with FCCP or oligomycin) and the amount of Ca2+ stored within the cells (released with ionomycin) was increased compared with cells treated with NaF under normal Na+ conditions. The NaF-initiated increase in [Ca2+]b and depletion of Bk-releasable Ca2+ pool(s) in the low-Na+ condition was diminished by 25 mumol l-1 ryanodine, indicating the involvement of Ca(2+)-induced Ca2+ release (CICR). 5. In simultaneous recordings of [Ca2+]sp (with FFP-18) and [Ca2+]b (with Calcium Green-1), 1 nmol l-1 Bk or 10 mmol l-1 NaF yielded focal [Ca2+] elevation in the subplasmalemmal region with no increase in the perinuclear area. 6. Treatment with 10 mumol-1 nocodazole caused the SER to collapse and unmasked Ca2+ release in response to 1 nmol l-1 Bk and 10 mmol l-1 NaF, similar to low-Na+ conditions, while the effect of thapsigargin was not changed. 7. These data show that in endothelial cells, focal, subplasmalemmal Ca2+ elevations in response to small or slow IP3 formation occur due to vectorial Ca2+ release from the SER towards the plasmalemma followed by Ca2+ extrusion by Na(+)-Ca2+ exchange. While these local Ca2+ elevations are not detectable with Ca2+ dyes for the determination of [Ca2+]b, prevention of Ca2+ extrusion or SER disruption yields increases in [Ca2+]b partially due to CICR. 8. All of the data support our hypothesis that in weakly stimulated endothelial cells, intracellular Ca2+ release and [Ca2+] elevation are limited to the subplasmalemmal region. We propose that the SER co-operates with associated parts of the plasma membrane to control Ca2+ homeostasis, Ca2+ distribution and Ca2+ entry. The existence of such a subplasmalemmal Ca2+ control unit (SCCU) needs to be considered in discussions of Ca2+ signalling, especially when cytoplasmic Ca2+ dyes, such as fura-2 or Calcium Green-1, are used.

Pharmacological characterization of alpha-adrenoceptors in the bovine median caudal artery

This study was initiated to characterize alpha-adrenoceptors in the isolated bovine median caudal (tail) artery preparation for use as a model of blood vessels in the extremities of cattle. Prazosin shifted the concentration-response relationship for noradrenaline and phenylephrine to the right with pA2 values of 8.74 and 9.04, respectively. Against noradrenaline, phentolamine yielded a pA2 of 7.36. The concentration-response relationship for medetomidine was not inhibited by rauwolscine or idazoxan. The noradrenaline KA was 3.11 microM. These results suggest that catecholamines elicit alpha-adrenoceptor-mediated contractions primarily through alpha1-adrenoceptors and not alpha2-adrenoceptors.

National legislation in Great Britain for the control of fish diseases

The Diseases of Fish Act 1937 of Great Britain is almost certainly the longest-standing example of national legislation specifically devised to control fish diseases. It was introduced in response to several outbreaks of furunculosis disease in wild salmon and other fish species in the rivers of England, Wales and Scotland, which were attributed to the importation of infected live rainbow trout from Germany. The Act totally prohibited the importation of live salmonids into Great Britain, and made it illegal to import salmonid ova and all live freshwater fish species without a licence. The Act also provided powers for authorised persons to enter onto any land to confiscate any fish, ova, foodstuff or articles suspected to have been illegally imported into Great Britain. Moreover, the Act enabled any disease to be designated as 'notifiable', meaning that even the suspicion of its presence in any waters must be reported to the official services. This legislation was eventually amended and extended by the Diseases of Fish Act 1983 to make it a legal requirement for all fish-farming businesses to become registered with the official services, and to maintain records of the movement of fish and fish ova into and from their sites. In 1986, additional powers were introduced under the Animal Health Act 1981 to limit the importation of dead, ungutted salmonid fish. In 1993, the legislation was amended to remove any legal conflict with European Economic Community Council Directive 91/67/EEC. In addition, the Diseases of Fish (Control) Regulations have since been passed so that new European Union rules for the control of infectious salmon anaemia, viral haemorrhagic septicaemia and infectious haematopoietic necrosis may be enforced nationally.

A perioperative elective for college credit

The authors developed a collaborative perioperative elective course between the Veterans Affairs Medical Center, Louisville, and Indiana University Southeast, New Albany. The course is for students studying for bachelor of science degrees in nursing and is offered as a four-hour elective. The course allows nursing students to participate more in surgical procedures; learn the proper use, care, and cleaning of surgical instruments; and learn nursing theory. Students' and staff members' responses have been favorable.

An optical comparator for measuring two-dimensional polyacrylamide gel electrophoresis records using an on-line microcomputer

A comparator which makes it possible to compare two wet gels or photographic negatives or autoradiograms through a flickering light system has been built. The system consists of two special-purpose projectors which combine the images on a digitizing platform. When the lights are switched On and off out of phase, the positions of the common components remain unchanged, whereas those that are spatially displaced appear to jump from side to side and those present in one image but not the other switch on and off. This produces a flickering image in which differences are readily seen. Commercial camera lenses were used to construct the projectors and the overall specifications for the system are given. The coordinates of both the displaced components, as well as the selected standards from the two images, are digitized and entered automatically into an on-line microcomputer. By using an iterative procedure for collecting records from several superimposable records of the gel, it is possible to compensate for the lack of total reproducibility over the whole gels. These coordinates are then normalized and superimposed on a master map through a television display using a curser to adjust the coordinates. The whole procedure can be repeated for many gels using a common reference gel in the comparator, and the result is a set of normalized coordinates which can be plotted on a single map to provide a final record of the experiments.

Rapid detection of infectious pancreatic necrosis virus (IPNV) by the enzyme-linked immunosorbent assay (ELISA)

The enzyme-linked immunosorbent assay (ELISA) was used to demonstrate the presence of infectious pancreatic necrosis virus (IPNV) antigen in cell cultures and in fish. Virus antigen could be detected in infected cell cultures before visible cytopathic effect (c.p.e.) was evident and cell cultures showing complete viral c.p.e. produced intense colour reactions. Virus antigen was detected in infected fry during and immediately after an epizootic, but although IPNV-carrier fish could be detected by the ELISA technique, the sensitivity of detection was not as great as that of isolation of the infectious virus in cell culture. The major IPNV serotypes, Sp, Ab and Vr, crossreacted at only a low level and it was shown that the ELISA technique could be used to serotype IPNV strains rapidly. None of 10 other fish pathogenic viruses reacted with plates sensitized for IPNV detection. The time taken to perform the technique was reduced to 1 h 35 min at room temperature and this still allowed the results to be readily assessed visually as antigen-positive or antigen-negative.

Sensory information, behavioral instructions and coping with sensory alteration surgery

This study compared the effect of a behavioral type of personal control and cognitive personal control information on cataract patients' postoperative orientation, indeterminate stimulus experiences, mood states, and performance (Ellis, 1972; Johnson, 1975; Seligman, 1975). Subjects were 40 patients, age 50 or older, scheduled for their first unilateral cataract surgical experience. Using a four-condition experimental design, patients were randomly assigned to: (1) behavioral instructions (behavioral control), (2) sensory information (cognitive control), (3) both behavioral instructions and sensory information, or (4) general information. It was found that neither behavioral nor cognitive control interventions had a significant effect on any of the dependent variables. However, the combination of behavioral and cognitive control intervention significantly reduced the number of days after discharge before patients elected to venture from their homes. No significant differences were found between experimental conditions in frequency of patient-reported indeterminate stimulus experiences (ISE).

Biophysical and biochemical characterization of five animal viruses with bisegmented double-stranded RNA genomes

Infectious pancreatic necrosis virus of fish, infectious bursal disease virus of chickens, Tellina virus and oyster virus of bivalve molluscs, and drosophila X virus of Drosophila melanogaster are naked icosahedral viruses with an electron microscopic diameter of 58 to 60 nm. The genome of each of these viruses consists of two segments of double-stranded RNA (molecular weight range between 2.6 x 10(6) and 2.2 x 10(6), and the virion, capsid proteins fall into three size class categories (large, medium, and small; ranging from 100,000 to 27,000) as determined by polyacrylamide slab gel electrophoresis. The hydrodynamic properties of the five viruses are similar as determined by analytical ultracentrifugation and laser quasi-elastic, light-scattering spectroscopy. The calculated particle weights range between 55 x 10(6) and 81 x 10(6). Tryptic peptide comparisons of 125I-labeled virion proteins showed that five viruses are different from each other, although there was considerable overlap in the peptide maps of the three aquatic viruses, indicting a degree of relatedness. Cross-neutralization tests indicated that drosophila X, infectious pancreatic necrosis, and infectious bursal disease viruses were different from each other and from oyster and Tellina viruses. The same test showed oyster and Tellina viruses to be related. The biochemical and biophysical properties of the five viruses cannt be included in the family Reoviridae or in any of the present virus genera.

Relationship of a virus from Tellina tenuis to infectious pancreatic necrosis virus

The physicochemical and serological properties of a virus isolated from the bivalve mollusc, Tellina tenuis, have been examined. The virus has a diam. of 59 nm, sediments at 430S in sucrose gradients and bands at a density of I-32 g/ml in CsCl. The virus contains RNA with a mol. wt. about 2-8 X 10(6) as extimated by polyacrylamide gel electrophoresis but in sucrose gradients the RNA sediments at 14S. The virus RNA is resistant to ribonuclease under conditions in which ribosomal RNA and the single stranded Mengo virus RNA are completely hydrolysed. Two major polypeptides, mol. wt. 67 and 40 X 10(3), and minor polypeptide, mol. wt. 110 X 10(3), are present in the virus particle. These properties are similar to those found in different serotypes of infectious pancreatic necrosis (IPN) virus. Although there was only a very low level of cross-neutralization between Tellina virus and IPN virus. there was some cross-reaction in immune electron microscopy tests and in immunofluorescence tests with infected tissue culture cells. This cross reaction, together with the close similarity in morphology and physiochemical properties, suggests that Tellina virus and IPN virus belong to the same virus group.

The importance of the stomach in mediating histamine-induced hypocalcemia in the rat

The effect of histamine on serum calcium homeostasis was studied in the rat. After the intravenous administration of 0.5-1.0 mg histamine base to fasted Holtzman rats weighing 80-100 g, a significant lowering of serum calcium (Ca) level occurred 30 min after injection (decrease in Ca, 1.4-1.9 mg/100 ml), but normocalcemia returned at 60 min. Repeat intravenous injections of histamine 1.0 mg resulted in repeated lowering of the serum Ca level. Hypophosphatemia did not accompany the hypocalcemia. Thyroparathyroidectomy (TPTX) did not eliminate the calcium-lowering effect of histamine in acute TPTX animals but did so in more chronic TPTX animals in which the mean serum Ca was 7.6 mg/100 ml or less. Gastrectomy, however, completely eliminated the calcium-lowering effect of histamine given in doses of up to 2 mg/rat (20 mg/kg of body weight), despite the presence of an intact thyroid gland. These studies support the role of a gastric factor and not the thyroid secretion of calcitonin in mediating this response in the rat.

Physico-chemical and serological characterization of five rhabdoviruses infecting fish

Viruses isolated from fish with viral haemorrhagic septicaemia (VHS), infectious haematopoietic necrosis (IHN), spring viraemia of carp (SVC), swim-bladder inflammation (SBI) and pike fry disease (PFD) have been grown to high titre in fathead minnow cells. While our preparations of the IHN, SVC, SBI and PFD viruses showed typical rhabdovirus morphology with bullet-shaped particles and distinct surface projections, the VHS virus preparations had a less typical rhabdovirus morphology but were pleomorphic with a preponderance of flexuous rods. Using virus labelled with [-3H]-uridine, it was shown that each virus contained RNA which sedimented at 38 to 40 S and was hydrolysed by very low concentrations of ribonuclease. The viruses of SVC, PFD and SBI had a polypeptide composition similar to that of vesicular stomatitis virus, the prototype rhabdovirus, but the IHN and VHS viruses gave a pattern similar to that of rabies virus. In serum neutralization tests the SVC and SBI viruses were indistinguishable. VHS virus showed no serological relationship with the other four viruses but there was a low level of cross-reaction between the PFD, IHN and SVC-SBI viruses.

Cineradiography of the braced normal cervical spine. A comparative study of five commonly used cervical orthoses

Five orthotic devices were selected for a study of their effectiveness in immobilizing the cervical spine. These orthoses were fitted to subjects with a normal range of motion of the cervical spine. Motion pictures were made from a lateral view while the patient actively flexed and extended his cervical spine as well as from the frontal view with the patient rotating to each side and bending to each side. The soft cervical collar offers very little immobilization. The firm plastic Thomas collar restricts about 75 per cent of flexion-extension, rotation and lateral bending. The four-poster orthosis gave 80 to 85 per cent restriction of flexion-extension and lateral bending but only restricted 60 per cent of rotation. The long two-poster cervical orthosis caused 90 to 95 per cent restriction of all motions. The Guilford two-poster cervical orthosis restricted 90 per cent of all motions.