Mitochondrial disease mimicking Charcot-Marie Tooth disease.
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Adult↗
Biomedical subjects
M Needham
Publications and source records attributed to M Needham.
Parkinsonism-hyperpyrexia syndrome: the role of electroconvulsive therapy.
Herein, we present a case of a parkinsonism-hyperpyrexia syndrome (PHS) in a 58-year-old man with a 10-year history of Parkinson's disease. The patient presented with a 2-week history of fever and increasing confusion, in the context of a number of changes to his medication regimen. On presentation, he was noted to be febrile with autonomic instability, diaphoresis and marked rigidity. He was disoriented and responding to visual hallucinations. Investigations revealed an elevated creatine kinase and a provisional diagnosis of PHS was made. After the patient failed to respond during a 2-week period to supportive measures, electroconvulsive therapy (ECT) treatment was commenced. A good response to eight bilateral ECT treatments was achieved, with resolution of his confusional state and associated psychotic phenomena. We discuss the nosological and management issues associated with this case and discuss the role of ECT as a treatment modality in this condition.
Acetaminophen↗
Exacerbations in {alpha}1-antitrypsin deficiency.
This study aimed to investigate the nature and effect of exacerbations in patients with alpha(1)-antitrypsin deficiency and to assess the impact of exacerbations on health status. Furthermore, the relationship of exacerbations to changes in lung function and health status was investigated. In total, 265 patients with severe deficiency (PiZ phenotype) were assessed over 12 months and a subgroup of 87 patients was studied for 3 yrs. Exacerbations were recorded and patients underwent full lung function testing and health status measurement. Exacerbations occurred in 142 patients (54%) over 12 months, with a median duration of 14 days (interquartile range 7-21). Health status was significantly worse in patients with exacerbations, especially those with frequent exacerbations. Neither the presence nor the frequency of exacerbations showed a relationship to decline in forced expiratory volume in one second, but the number of exacerbations was weakly associated with decline in gas transfer of the lung for carbon monoxide. Despite lung function decline, health status did not change significantly over 3 yrs. In conclusion, exacerbations occur commonly in patients with alpha(1)-antitrypsin deficiency and are associated with worse health status. Exacerbations were associated with a decline in the gas transfer of the lung for carbon monoxide over time, but show no relationship to changes in forced expiratory volume in one second. Despite lung function decline, patients do not show a progressive loss in health status.
Administration, Inhalation↗
Alpha 1-antitrypsin deficiency. 3: Clinical manifestations and natural history.
A review of the clinical manifestations of alpha(1)-antitrypsin (AAT) deficiency, including lung disease and liver disease, and risk factors affecting the rate of decline in lung function in AAT deficient patients.
Age Factors↗
hnRNP B1 expression in benign and malignant lung disease.
Evidence is accumulating to suggest that hnRNP B1 expression may be a useful tool in the early diagnosis of lung cancer. This study examined the immunohistochemical expression of hnRNP B1 in archived sections of resected lung cancers and compared the patterns of expression with those seen in similar archived sections of non-neoplastic lung. Particular attention was paid to the expression of hnRNP B1 in the benign bronchial cells in both cases, to establish if overexpression of this protein in respiratory epithelial cells is specific for malignancy. Nineteen cases of different types of non-small cell carcinoma were examined (eight squamous cell, six adenocarcinomas, two carcinosarcomas, two undifferentiated large cell carcinomas, and one mucoepidermoid carcinoma) and compared with sections from 16 open lung biopsies (three cases of cryptogenic fibrosing alveolitis, two cases of sarcoidosis, two cases of organizing pneumonia, and one case each of tuberculosis, extrinsic allergic alveolitis, non-specific interstitial pneumonitis, pneumocystis pneumonia, aspergilloma, respiratory bronchiolitis-interstitial lung disease, mineral dust disease, Sjögren's syndrome and systemic sclerosis vascular variant). All the tumours showed positive staining, with the vast majority, 16/19 (84%), showing strong diffuse nuclear staining. The background cells of these cases showed positive staining in alveolar macrophages, lymph node germinal centres, bronchial mucous glands, and bronchial epithelial cells. No significant difference was seen in the percentage of positive bronchial epithelial cells in bronchi adjacent to the tumour compared with the resection margins. In the benign lung cases, positive bronchial epithelial cells were seen in a small percentage, 3/16 (18%), of cases, but the majority of cases showed no or very focal staining. The levels of expression between benign epithelial cells of malignant cases, compared with benign, showed a significant difference when the staining was assessed in percentage of positive nuclei (p = 0.001, Fisher's exact test). The results confirm that hnRNP B1 is widely expressed in a range of lung carcinomas; that expression is seen in benign bronchial epithelial cells and inflammatory cells; and that expression in background bronchial epithelial cells appears to be higher in malignant than in benign lung disease. It is feasible that this biomarker may be of use in the detection of early lung cancer, provided that levels of expression can be accurately quantified.
Adenocarcinoma↗
In vivo release of oxytetracycline from a biodegradable controlled-release gel injected subcutaneously in Japanese quail (Coturnix coturnix japonica).
A long-acting, biodegradable, controlled-release formulation of oxytetracycline (CR-OTC) was evaluated in 18 adult Japanese quail (Coturnix coturnix japonica) following a single subcutaneous (s.c.) injection. Prior to characterizing the release of oxytetracycline (OTC) from the CR-OTC, the pharmacokinetic parameters of intravenously (i.v.) administered OTC were determined. Concentrations of free OTC were measured using a bioassay. The plasma concentration-time profile of OTC after a single i.v. injection at 20 mg/kg was best fit to an open two-compartmental model, with the following pharmacokinetic parameters: area under the curve (AUC) = 36.72 mg. h/L, terminal elimination half-life = 2.34 h, clearance (Cl) = 0.545 L/kg/h. Plasma [OTC] was >1.0 micro g/mL for at least 4 h following i.v. injection. The CR-OTC gel was well tolerated at a dosage of 1500 mg/kg s.c. Plasma [OTC] rose to >1.0 micro g/mL within 24 h; it remained >1.0 micro g/mL for at least 10 days in all birds sampled at that time point (n = 9) and for at least 18 days in two of nine birds. Using a deconvolution technique, it was determined that approximately 54.8% of the administered OTC was released from the CR-OTC over the 45-day observation period. This long-acting, biodegradable controlled-release OTC formulation may have potential for the treatment of chlamydophila infections and other OTC-sensitive bacteria in Japanese quail, however further studies are necessary to determine its safety and clinical application.
Animals↗
Clinical, microscopic, and molecular aspects of canine leproid granuloma in the United States.
Leproid granulomas from seven dogs in the United States were evaluated. Gross characteristics included nodular and ulcerated dermal and subcutaneous lesions primarily on the caudal aspects of the pinnae and to a lesser extent on the muzzle, face, and forelimbs. In all except one dog, there was complete regression of the lesions within 6 months, either with no therapy or after surgical resection. Cytology or histopathology revealed pyogranulomatous inflammation with few to many acid-fast mycobacterial bacilli within macrophages. The organisms could not be cultivated in vitro. DNA sequencing of part of the 16S ribosomal RNA gene region revealed 99-100% homology among fragments from five of these dogs and fragments from dogs in the south Pacific. This syndrome occurs in dogs in North America and the prognosis is excellent, in contrast to the prognosis for rapid-growing or tuberculous mycobacteriosis.
Animals↗
Functional expression of a locust tyramine receptor in murine erythroleukaemia cells.
The LCR/MEL system (Locus Control Region/Murine Erythroleukaemia cells) was employed to express and characterize the Locusta migratoria tyramine receptor (TyrLoc), an insect G protein-coupled receptor. Functional agonist-dependent responses were recorded in stable, tyramine receptor expressing cell clones (MEL-TyrLoc). Tyramine elicited a dose-dependent increase of cytosolic Ca2+-ions and an attenuation of forskolin-induced cyclic adenosine monophosphate (AMP) production. Octopamine was shown to be a weak agonist for both responses. In addition, yohimbine proved to be a potent tyramine receptor antagonist. This study reports the first application of the LCR/MEL expression system in functional assays for G protein-coupled receptors and therefore expands the capabilities of this system by exploiting the functionality of the signal transduction pathways.
Animals↗
Interaction of glucocorticoid receptor isoforms with transcription factors AP-1 and NF-kappaB: lack of effect of glucocorticoid receptor beta.
Glucocorticoids act through the glucocorticoid receptor (GR) to enhance or repress transcription of glucocorticoid responsive genes depending on the promoter context and cellular background. The human GR primary transcript is alternatively spliced resulting in hGR alpha and hGR beta isoforms. Transactivation and transrepression are mediated by hGR alpha and while it has been demonstrated that hGR beta, can act as a dominant negative inhibitor of hGR alpha mediated transactivation, its effects on transrepression are not known. To investigate hGR beta actions, we used GR-deficient COS-7 and HEK-293 cells. When hGR alpha (0.5 microg 10(6) cells(-1)) was transfected into COS-7 cells dexamethasone (150 nM) inhibited TNF alpha (80 U ml(-1)) effects on a NF-kappaB responsive reporter gene by 40%. There was no evidence of a dominant negative effect when hGR beta (1-10 microg) was co-transfected with hGR alpha up to ratios of 10:1. Similarly hGR beta had no effect on hGR alpha inhibition of a phorbol ester stimulated Ap-1-responsive reporter gene in COS-7 or HEK-293 cells. In comparison, an apparent dominant negative effect of hGR beta on hGR alpha-mediated transactivation was found to be attributable to non-specific transcriptional squelching in COS-7 cells. In summary, the potential for hGR beta, to act as a dominant negative inhibitor of hGR alpha-mediated transactivation remains controversial, but our data suggest that hGR beta, was unable to act as a dominant negative inhibitor of either hGR alpha-mediated transrepression or transactivation in these promoter and cell contexts.
Animals↗
Lymphocyte targeting of the brain in adoptive transfer cryolesion-EAE.
Lymphocyte infiltration and microglial activation in experimental autoimmune encephalomyelitis (EAE) are mainly centred on the spinal cord. However, a cryolesion to one cerebral hemisphere (cryolesion-EAE) induces six-fold enhancement of EAE in the cerebral hemispheres and removal of the cervical lymph nodes reduces such enhancement by 40 per cent. This study tests the hypothesis that lymphocytes from donor rats with cryolesion-EAE will selectively target the brain rather than the spinal cord when transferred to naive recipients. Acute EAE was induced in 15 Lewis rats (donors); ten donors received a cryolesion to the left cerebral hemisphere 8 days post-inoculation of antigen and adjuvant. Five rats with EAE received no cryolesion. Lymphocytes from cryolesion-EAE donors or from EAE-only donors were cultured for 72 h in medium containing myelin basic protein and then injected into a total of 21 naive recipients, which were killed 8 days later. The severity of EAE in brains and spinal cords was assessed in immunocytochemically stained sections by quantifying the number of vessels showing lymphocyte cuffs (W3/13 antibody) and the level of MHC class II antigen expression by microglia (OX6 antibody). When compared with recipients of EAE-only donor lymphocytes, the severity of cerebral EAE was increased 2- to 2.6-fold in the recipients of crylesion-EAE donor lymphocytes (p < 0.01); EAE in the spinal cord was reduced. These results suggest that lymphocytes from cryolesion-EAE donors preferentially target the brain in recipient animals in preference to the spinal cord. By analogy with cryolesion-EAE, focal central nervous system (CNS) damage with drainage of auto-antigens to regional lymph nodes in man may play a role in determining the site and timing of initial and recurrent multiple sclerosis lesions.
Acute Disease↗
The oestrogen receptor regulates NFkappaB and AP-1 activity in a cell-specific manner.
Oestrogens regulate the expression of genes both positively and negatively in a range of cell types. These effects are mediated via the oestrogen receptor (ER) and involve direct interactions between the ER and DNA response elements, as well as interactions between the ER and other nuclear proteins. We have examined the potential of the ERalpha to regulate the expression of reporter genes under the control of oestrogen response elements (EREs), NFkappaB response elements (NREs) or AP-1/TPA response elements (TREs) in HeLa cells and in human embryonic kidney (HEK-293) cells. Transiently transfected ERalpha was able to activate expression of beta-galactosidase under the control of EREs in an oestradiol (E2)-dependent manner in both HeLa and HEK-293 cells. The ERalpha was able to repress by 80% the TNF-mediated expression of beta-galactosidase under the control of NREs in an E2-dependent manner in HeLa cells but not in HEK-293 cells. ERalpha/E2 also induced a two-fold potentiation of TPA-mediated expression of beta-galactosidase under the control of TREs in HeLa cells but not in HEK-293 cells. These results suggest that the ERalpha is capable of regulating gene expression in a cell-specific manner. We further investigated the mechanisms by which the ERalpha regulates gene expression in these systems by co-expressing the ERalpha and the reporter gene constructs with known cofactors of the ERalpha. We have shown that expression of steroid receptor coactivator-1 alpha (SRC-1alpha) and receptor interacting protein-140 (RIP-140) have no effect on the capacity of the ERalpha to modulate NFkappaB reporter gene activity in HeLa cells. Furthermore, the expression of SRC-1alpha or RIP-140 does not enable the ERalpha to repress NFkappaB or to potentiate an AP-1 response in HEK-293 cells. This suggests that factors other than SRC-1alpha or RIP-140 are responsible for the cell-specific effects seen with ERalpha.
Dexamethasone↗
Pharmacokinetics of ceftiofur sodium in exotic and domestic avian species.
The pharmacokinetics of ceftiofur sodium were determined in domestic chicks, turkey poults, adult cockatiels (Nymphicus hollandicus), and adult orange-winged Amazon parrots (Amazona amazonica) after subcutaneous (chicks and turkey poults and intramuscular (i.m.) dosing (cockatiels and Amazon parrots). Turkey poult data were best fit to a single exponential model with disappearance half-lives (t1/2) of 8.6, 7.4 and 5.6 h after doses of 0.12, 0.24 and 0.48 mg ceftiofur free acid equivalents (CFAE)/poult, respectively. Data from chicks were best fit to a biexponential model with primary and secondary half-lives of 2.2 and 7.5, 3.7 and 6.8, and 3.8 and 5.3 h after doses of 0.04, 0.08 and 0.16 mg CFAE/chick, respectively. Cockatiel and Amazon parrot data were best fit to a biexponential model with primary and secondary half-lives of 0.28 and 2.5, and 0.93 and 7.9 h, respectively, after doses of 10 mg CFAE/kg body weight. The maximum concentration (Cmax) and area under the concentration time curve (AUC) in chicks and poults were dose-proportional. The Cmax for cockatiels was 5.2 micrograms/mL and for Amazon parrots was 11 micrograms/mL. Clearance in cockatiels and Amazon parrots were 11.3 and 3.8 mL/min/kg, respectively, and reflected the much greater AUC seen in Amazon parrots. Clearance values of ceftiofur were similar in chicks and Amazon parrots, slightly greater in turkey poults and greatest in cockatiels. These results indicate that pharmacokinetic differences must be considered when establishing dosage regimens for different avian species.
Animals↗
Role of cervical lymph nodes in autoimmune encephalomyelitis in the Lewis rat.
Lymphocytes enter the central nervous system (CNS) in response to virus infections and in autoimmune diseases, such as multiple sclerosis (MS), but the origin of such lymphocytes is unclear. This study investigates the role of the cervical lymph nodes as a source of lymphocytes involved in experimental autoimmune disease of the brain. Acute active experimental autoimmune encephalomyelitis (EAE) is used as a model for the autoimmune aspects of MS and is characterized by lymphocyte and monocyte invasion and microglial activation, mainly in the spinal cord, 12-15 days post-inoculation (dpi) of antigen. Few lesions occur in the cerebral hemispheres in acute EAE, but a cryolesion to the surface of the brain 8 dpi results in a six-fold enhancement of cerebral EAE. The present study tests the hypothesis that cervical lymphadenectomy will reduce the enhancement of cerebral EAE induced by a cryolesion. Acute EAE was induced in 25 Lewis rats and a cryolesion to the brain, 8 dpi, in 16 rats was immediately followed by either cervical lymphadenectomy (n = 8) or sham lymphadenectomy (n = 8). The severity of EAE at 15 dpi, in the brain and spinal cord, was evaluated using immunocytochemistry for T lymphocytes (W3/13) and MHC class II expression (OX6). The results of the study showed that cervical lymphadenectomy reduced the level of cerebral EAE induced by a cryolesion by 40 per cent when compared with the sham-operated animals (P < 0.01). This suggests that cervical lymph nodes play a pivotal role in the induction of EAE in the brain, possibly as a site for 'priming' T cells to target the brain. Investigation of the interrelationships between cervical lymph nodes and the brain in man may lead to new therapeutic strategies for multiple sclerosis.
Animals↗
Cloning and expression of cystolic phospholipase A2 (cPLA2) and a naturally occurring variant. Phosphorylation of Ser505 of recombinant cPLA2 by p42 mitogen-activated protein kinase results in an increase in specific activity.
Full-length cytosolic phospholipase A2 (cPLA2) was cloned from U937 cells and polymorphonuclear leukocytes (PMNLs) while a naturally occurring variant of cPLA2, which lacks residues Val473-Ala749 but has a C-terminal extension of ILMNLSEYMLWMSKVKRFM (DcPLA2) was cloned from PMNLs and mononuclear leukocytes. We were unable to clone DcPLA2 from U937 cells. When cPLA2 and DcPLA2 were expressed in insect cells, both proteins were detected in cell lysates by SDS/PAGE as single bands of apparent molecular masses 100 kDa and 57 kDa, respectively. Full-length cPLA2 was phosphorylated stoichiometrically by p42 mitogen-activated protein (MAP) kinase in vitro at a similar rate to other physiological substrates of this protein kinase and the major site of phosphorylation was identified by amino acid sequencing as Ser505. [32P]Ser(P)505 in cPLA2 was only dephosphorylated at a slow rate by mammalian tissue homogenates. Protein phosphatases 2A, 2B and 2C all contributed significantly to the overall dephosphorylation of cPLA2. The phosphorylation of cPLA2 by p42 MAP kinase correlated with an approximately 1.5-fold increase in specific enzyme activity which was reversed by dephosphorylation.
Amino Acid Sequence↗
Monocyte chemoattractant protein-1: receptor interactions and calcium signaling mechanisms.
Monocyte chemoattractant protein-1 (MCP-1) is a member of the Cys-Cys chemokine family. Two related MCP-1 receptors have been identified (CC-CKR2A and CC-CKR2B), although the precise kinetics of ligand binding and calcium signaling of these receptors has yet to be investigated. To examine this more closely, the human MCP-1 receptors were cloned and expressed in Chinese hamster ovary (CHO) cells. Membranes prepared from cells expressing CC-CKR2B bind MCP-1 selectively and with high affinity (Kd = 120 pM). MCP-1 stimulation of recombinant CHO cells expressing CC-CKR2B induces a rapid increase in intracellular Ca2+ through both receptor-operated Ca2+ channels and mobilization of Ca2+ from intracellular stores, and leads to a rapid temperature-dependent internalization of the ligand/receptor complexes. In contrast, recombinant CHO cells expressing CC-CKR2A, and membranes prepared from these cells, fail to bind detectable levels of MCP-1. However, MCP-1 stimulation of cells expressing CC-CKR2A induces a small but significant increase in intracellular Ca2+. Repeated stimulation of these cells with MCP-1 leads to a potentiation of the response to a level comparable to that seen in cells expressing CC-CKR2B. These observations suggest that the levels of cell surface CC-CKR2A are controlled by novel mechanisms.
Animals↗
High level expression of human MCP-1 using the LCR/MEL expression system.
We have expressed human monocyte chemoattractant protein-1 (hMCP-1) in preerythroid mouse erythroleukemia (MEL) C88 cells using the locus control region/MEL expression system and studied the biological activity of the purified protein in a range of in vitro experimental systems. The recombinant hMCP-1 is expressed at high levels (approximately 10 mg/liter) in this system and is modified in a manner which is very similar to native hMCP-1. We have developed a simple high-yielding two-step purification route employing dye ligand and ion exchange chromatographies which enables us to separate glycosylated and unglycosylated hMCP-1. The purified glycosylated and unglycosylated forms of hMCP-1 have equivalent biological activities in all of the assay systems tested.
Animals↗
Further development of the locus control region/murine erythroleukemia expression system: high level expression and characterization of recombinant human calcitonin receptor.
In order to demonstrate the potential of the LCR/MEL expression system for the expression of seven-transmembrane helix receptors the human calcitonin receptor (hCTR) has been cloned and expressed at high levels in this system. Using the newly developed single-step expression vectors pEV and pNV, stable recombinant MEL cells which express the hCTR at approximately 6 pmol of receptor/mg of total cell protein (60 pmol/mg of membrane protein), or 1.9 x 10(6) receptors per cell, have been generated. Ligand binding studies have shown that the cloned receptor expressed in MEL cells has properties which are indistinguishable from those of the native receptor in T47D cells. It is suggested that MEL cells expressing seven-transmembrane helix receptors provide an efficient and readily attainable source of material for ligand binding experiments using these receptors.
Animals↗
Identification of multiple human calcitonin receptor isoforms: heterologous expression and pharmacological characterization.
The human breast carcinoma cell line T47D is known to express high-affinity calcitonin receptors (CTRs). PCR amplification of the CTR cDNA from T47D mRNA resulted in the identification of two different cDNAs that encode distinct receptor isoforms, h alpha CTR and h beta CTR. The two cDNAs are identical except that the h alpha CTR cDNA contains a 48 bp insert sequence that encodes a 16 amino acid domain in the first cytosolic loop of the receptor. Stable transfection of each receptor cDNA into murine erythroleukaemia (MEL) cells resulted in the expression of receptors with high affinity for radiolabelled salmon calcitonin (h alpha CTR Kd 0.09 nM, h beta CTR Kd 0.12 nM). Ligand competition binding studies did not reveal any significant pharmacological difference between the receptor isoforms. In transfected MEL cells and COS-1 cells the h beta CTR isoform was expressed at tenfold higher levels than the h alpha CTR. A reporter gene assay that monitored the coupling of CTR to adenylate cyclase by increases in beta-galactosidase activity indicated that both receptors were able to stimulate cyclic AMP production in response to ligand binding.
Adenylyl Cyclases↗