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1.
Clin Radiol ; 74(1): 80.e19-80.e26, 2019 01.
Article in English | MEDLINE | ID: mdl-30447997

ABSTRACT

AIM: To determine local control, safety, and survival following percutaneous computed tomography (CT)-guided high-power microwave ablation (MWA) in the treatment of primary lung malignancy at a single institution. MATERIAL AND METHODS: From July 2010 to June 2016, 52 patients (mean age 76.3 years, range 55-91 years) with 61 unresectable primary lung cancers of mean diameter 23.8 mm (range 26-55 mm) underwent MWA in 55 ablation sessions. Tumours were diagnosed at biopsy, or positron-emission tomography (PET) avidity (mean SUV max = 10.51) and interval growth. Statistical analysis was performed by Kaplan-Meier modelling and Cox and logistic regression. RESULTS: Local tumour progression (LTP) was diagnosed in six lesions (10%). Median time to local recurrence was 3 months (range 2-14 months). There was a near 12-fold increased odds of local recurrence if the lesion size was >3 cm (95% confidence interval [CI]: 1.84-75.14; p=0.009). The median inpatient stay was 1 day, with no intra-procedural deaths and a 0% 30-day post-ablation mortality rate. Pneumothorax requiring drain was the most serious complication, occurring in 22% (n=12) of patients. Presence of severe emphysema and predicted forced expiratory volume in 1 second (FEV1) of <50% were found to predict future requirement of a drain (odds ratio [OR] 8.17, 95% CI: 1.62-41.37, p=0.01 and OR: 5.14, 95% CI: 1.28-20.68, p=0.02 respectively), when adjusted for age and gender. Tumour size >3 cm had a hazard ratio of 4.37 compared with tumour size ≤3 cm (95% CI: 1.45-13.17, p=0.009) of risk of cancer death at any time, by Cox regression. CONCLUSION: MWA for primary lung malignancy is a safe and effective treatment for primary lung tumours with outcomes that may be comparable to stereotactic body radiation therapy.


Subject(s)
Lung Neoplasms/surgery , Microwaves/therapeutic use , Radiofrequency Ablation/methods , Aged , Aged, 80 and over , Female , Humans , Kaplan-Meier Estimate , Logistic Models , Lung Neoplasms/mortality , Male , Middle Aged , Neoplasm Recurrence, Local/diagnosis , Neoplasm Recurrence, Local/epidemiology , Positron-Emission Tomography , Proportional Hazards Models , Radiofrequency Ablation/adverse effects , Radiofrequency Ablation/mortality , Radiography, Interventional , Tomography, X-Ray Computed
2.
BMC Palliat Care ; 15: 36, 2016 Mar 24.
Article in English | MEDLINE | ID: mdl-27009550

ABSTRACT

BACKGROUND: Empirical knowledge around palliative care provision and needs of people with intellectual disabilities is extremely limited, as is the availability of research resources, including expertise and funding. This paper describes a consultation process that sought to develop an agenda for research priorities for palliative care of people with intellectual disabilities in Europe. METHODS: A two-day workshop was convened, attended by 16 academics and clinicians in the field of palliative care and intellectual disability from six European countries. The first day consisted of round-table presentations and discussions about the current state of the art, research challenges and knowledge gaps. The second day was focused on developing consensus research priorities with 12 of the workshop participants using nominal group technique, a structured method which involved generating a list of research priorities and ranking them in order of importance. RESULTS: A total of 40 research priorities were proposed and collapsed into eleven research themes. The four most important research themes were: investigating issues around end of life decision making; mapping the scale and scope of the issue; investigating the quality of palliative care for people with intellectual disabilities, including the challenges in achieving best practice; and developing outcome measures and instruments for palliative care of people with intellectual disabilities. CONCLUSIONS: The proposal of four major priority areas and a range of minor themes for future research in intellectual disability, death, dying and palliative care will help researchers to focus limited resources and research expertise on areas where it is most needed and support the building of collaborations. The next steps are to cross-validate these research priorities with people with intellectual disabilities, carers, clinicians, researchers and other stakeholders across Europe; to validate them with local and national policy makers to determine how they could best be incorporated in policy and programmes; and to translate them into actual research studies by setting up European collaborations for specific studies that require such collaboration, develop research proposals and attract research funding.


Subject(s)
Consensus , Intellectual Disability/therapy , Palliative Care/methods , Research , Europe , Health Services Research , Humans
3.
bioRxiv ; 2024 Sep 24.
Article in English | MEDLINE | ID: mdl-39386649

ABSTRACT

The ability to induce allograft specific tolerance would reduce the need for daily pharmacological immunosuppression, improve post-transplant quality of life and transplant outcomes. Adoptive cell therapy with regulatory T cells expressing donor-specific Chimeric Antigen Receptors (CAR-Tregs) is a promising strategy, but monotherapy has not resulted in prolonged survival of grafts with multiple MHC mismatches. We used a clinically-relevant, haplo-mismatched model of heart transplantation in immune-competent C57BL/6 recipients to test the ability of HLA-A2-specific (A2) CAR Tregs to synergize with CD154 blockade to enhance graft survival. We found that in combination with a single low dose of anti-CD154, A2.CAR Tregs significantly prolonged heart allograft survival. Through use of grafts expressing the 2W-OVA transgene, tetramer tracking of 2W- and OVA-specific cells revealed that in mice with accepted grafts, the effects of A2.CAR Tregs included inhibition of endogenous donor-specific CD4 + and CD8 + T cell expansion, and B cell and antibody responses. Moreover, within the 2W-specific CD4 + T cell population, there was a significant increase in the proportion of FoxP3 pos cells, suggestive of infectious tolerance. In mice where CD154 blockade and A2.CAR Tregs failed to prolong graft survival, there was preferential expansion of FoxP3 neg A2.CAR T cells within the rejecting allograft. Thus, this study provides the first evidence for a synergistic effect between CAR Tregs and CD40-pathway blockade and supports the further refinement of this strategy as a promising future direction towards the goal of transplantation tolerance.

4.
Curr Biol ; 4(2): 89-99, 1994 Feb 01.
Article in English | MEDLINE | ID: mdl-7953530

ABSTRACT

BACKGROUND: TCP-1 is a 60 kD subunit of a cytosolic hetero-oligomeric chaperone that is known to be involved in the folding of actin and tubulin. This protein is a member of the chaperonin family, which includes Escherichia coli GroEL, the mitochondrial heat-shock protein Hsp60, the plastid Rubisco-subunit-binding protein and the archaebacterial protein TF55. These chaperonins assist the folding of proteins upon ATP hydrolysis. RESULTS: Using two-dimensional gel analysis, we have identified nine different subunits of TCP-1-containing chaperonin complexes from mammalian testis and seven different subunits of such complexes from mouse F9 cells. We have isolated full-length mouse cDNAs encoding six novel TCP-1-related polypeptides and show that these cDNAs encode subunits of the TCP-1-containing cytosolic chaperonin. These subunits are between 531 and 545 residues in length. Their sequences are 25-36% identical to one another, 27-35% identical to that of TCP-1 and 32-39% identical to that of the archaebacterial chaperonin, TF55. We have named these genes, Cctb, Cctg, Cctd, Ccte, Cctz and Ccth, which encode the CCT beta, CCT gamma, CCT delta, CCT epsilon, CCT zeta and CCT eta subunits, respectively, of the 'Chaperonin Containing TCP-1' (CCT). All the CCT subunits contain motifs that are also shared by all other known chaperonins of prokaryotes and eukaryotic organelles, and that probably relate to their common ATPase function. CONCLUSION: It is likely that each CCT subunit has a specific, independent function, as they are highly diverged from each other but conserved from mammals to yeast. We suggest that the expansion in the number of types of CCT subunit, compared with other chaperonins, has allowed CCT to carry out the more complex functions that are required for the folding and assembly of highly evolved eukaryotic proteins.


Subject(s)
Chaperonins/biosynthesis , Intracellular Signaling Peptides and Proteins , Microtubule-Associated Proteins , Nuclear Proteins/biosynthesis , Nuclear Proteins/genetics , Actins/metabolism , Amino Acid Sequence , Animals , Base Sequence , Caenorhabditis elegans/metabolism , Cell Line , Chaperonins/genetics , Consensus Sequence , DNA Primers , Escherichia coli/genetics , Escherichia coli/metabolism , Gene Library , Humans , Macromolecular Substances , Male , Mice , Molecular Sequence Data , Nuclear Proteins/metabolism , Polymerase Chain Reaction , Protein Folding , Sequence Homology, Amino Acid , Testis/metabolism , Tubulin/metabolism , Ubiquitin-Protein Ligases , t-Complex Genome Region
5.
Mech Dev ; 47(1): 73-80, 1994 Jul.
Article in English | MEDLINE | ID: mdl-7947323

ABSTRACT

The mouse t-complex is known to harbour genes which affect male fertility. Tcp-11 is a t-complex gene which is only expressed in male germ cells and from its position is a candidate for a distorter, one of the two types of genetic element involved in transmission ratio distortion. Antibodies raised to TCP-11 protein made in E. Coli were used on thin sections of testis and shown to recognise late spermatids. On Western blots the antibodies bound to a 68-kD protein present in protein extracts from testis. No specific signal could be detected using the antibody on protein extracts from other mouse tissues. Following gentle lysis of the germ cells and fractionation on sucrose gradients, all the material recognised by the anti-Tcp-11 antibody was found to be soluble and unassociated with any membrane fraction or organelle. A comparison of the time course of expression of the Tcp-11 mRNA and the TCP-11 protein revealed that expression of this gene is under translational control.


Subject(s)
Intracellular Signaling Peptides and Proteins , Microtubule-Associated Proteins , Nuclear Proteins/genetics , Transcription, Genetic , Animals , Blotting, Northern , Blotting, Western , Male , Membrane Proteins , Mice , Nuclear Proteins/analysis , Polymerase Chain Reaction , RNA, Messenger/analysis , RNA, Messenger/genetics , Testicular Hormones/genetics , Testis/chemistry , Time Factors , Ubiquitin-Protein Ligases , t-Complex Genome Region
6.
Gene ; 154(2): 231-6, 1995 Mar 10.
Article in English | MEDLINE | ID: mdl-7890169

ABSTRACT

The chaperonin containing t-complex polypeptide 1 (TCP-1), as one of its subunits, CCT, is a cytosolic heterooligomeric molecular chaperone assisting in the folding of proteins in eukaryotic cytosol. We have isolated a Tcp-1-related 119-bp cDNA fragment from a human cDNA library by polymerase chain reaction, and cloned full-length mouse cDNAs orthologous to the human cDNA by hybridization. The nucleotide (nt) sequence of the longest mouse clone (1844 bp) shows an open reading frame (ORF) encoding a TCP-1-related polypeptide of 548 amino acids (aa) (59,562 Da). This gene is different from Tcp-1 and the six Tcp-1-related genes reported previously, Tcp-1 (Ccta), Cctb, Cctg, Cctd, Ccte, Cctz and Ccth, which encode subunits of CCT. The product of the novel gene was analysed using an antibody raised against the C terminus of the polypeptide deduced from the nt sequence. We found that this gene encodes a subunit of CCT (polypeptide S1; 62 kDa and pI 6.25 by two-dimensional gel analysis). We have named it Cctq, encoding the theta subunit of CCT (CCT theta). The aa sequence of CCT theta shows 23-29% identity to the other CCT subunits, alpha, beta, gamma, delta, epsilon, zeta and eta, and 29% identity to the archaebacterial chaperonin TF55. CCT theta also contains the motifs common to all the other subunits of CCT which are postulated to be involved in ATPase activity.


Subject(s)
Chaperonins/genetics , Multigene Family , Amino Acid Sequence , Animals , Archaea/genetics , Base Sequence , Chaperonin Containing TCP-1 , Chaperonins/biosynthesis , Chaperonins/chemistry , Cloning, Molecular , Conserved Sequence , Cytosol/chemistry , DNA, Complementary/genetics , Electrophoresis, Gel, Two-Dimensional , Humans , Male , Mice , Molecular Sequence Data , Organ Specificity , Peptide Fragments/chemistry , Peptide Fragments/genetics , Phylogeny , Protein Folding , Sequence Alignment , Sequence Homology, Amino Acid , Sequence Homology, Nucleic Acid , Testis/chemistry
7.
FEBS Lett ; 358(2): 129-32, 1995 Jan 23.
Article in English | MEDLINE | ID: mdl-7828721

ABSTRACT

We describe a panel of antibodies specific to individual subunits of the chaperonin-containing TCP-1 (CCT) and one antibody that reacts with all the subunits of CCT. Immunoblot analysis of CCT purified from mouse testis suggests that the testis-specific subunit, S6, may be related to CCT zeta and that a co-purifying 63 kDa protein may be a novel subunit of CCT. Using these antibodies in the analysis of CCT subjected to nondenaturing IEF we observed the resolution of two distinct conformations of CCT, which differ in their susceptibility to proteolysis and in the number of associated polypeptides.


Subject(s)
Chaperonins/chemistry , Intracellular Signaling Peptides and Proteins , Microtubule-Associated Proteins , Nuclear Proteins/chemistry , Testis/chemistry , Animals , Antibodies/immunology , Hydrolysis , Male , Mice , Nuclear Proteins/immunology , Protein Conformation , Ubiquitin-Protein Ligases , t-Complex Genome Region
8.
FEBS Lett ; 402(1): 53-6, 1997 Jan 27.
Article in English | MEDLINE | ID: mdl-9013858

ABSTRACT

We have cloned a novel Tcp-1-related mouse testis cDNA encoding a polypeptide of 531 amino acids which shares 81.2% identity with the zeta subunit of the mouse cytosolic chaperonin-containing TCP-1 (CCT). Immunoblot analysis of mouse testis CCT subunits separated by 2-dimensional gel electrophoresis indicates that this novel gene, Cctz-2, encodes a CCT subunit of Mr 57 000 and pI 7.1. Cctz-2 mRNA is detected only in testis whereas the other Cctz gene, Cctz-1, is expressed in all tissues investigated. The CCTzeta-2 subunit may have specific functions in the folding of testicular proteins and for interactions with testicular molecular chaperones.


Subject(s)
Chaperonins/genetics , Testis/metabolism , Amino Acid Sequence , Animals , Blotting, Northern , Chaperonin Containing TCP-1 , Chaperonins/chemistry , Cloning, Molecular , DNA, Complementary/genetics , Humans , Immunoblotting , Isoelectric Point , Male , Mice , Molecular Sequence Data , Molecular Weight , Organ Specificity
9.
Environ Mol Mutagen ; 38(1): 59-68, 2001.
Article in English | MEDLINE | ID: mdl-11473389

ABSTRACT

This laboratory previously described a single-laser flow cytometric method, which effectively resolves micronucleated erythrocyte populations in rodent peripheral blood samples. Even so, the rarity and variable size of micronuclei make it difficult to configure instrument settings consistently and define analysis regions rationally to enumerate the cell populations of interest. Murine erythrocytes from animals infected with the malaria parasite Plasmodium berghei contain a high prevalence of erythrocytes with a uniform DNA content. This biological model for micronucleated erythrocytes offers a means by which the micronucleus analysis regions can be rationally defined, and a means for controlling interexperimental variation. The experiments described herein were performed to extend these studies by testing whether malaria-infected erythrocytes could also be used to enhance the transferability of the method, as well as control intra- and interlaboratory variation. For these studies, blood samples from mice infected with malaria, or treated with vehicle or the clastogen methyl methanesulfonate, were fixed and shipped to collaborating laboratories for analysis. After configuring instrumentation parameters and guiding the position of analysis regions with the malaria-infected blood samples, micronucleated reticulocyte frequencies were measured (20,000 reticulocytes per sample). To evaluate both intra- and interlaboratory variation, five replicates were analyzed per day, and these analyses were repeated on up to five separate days. The data of 14 laboratories presented herein indicate that transferability of this flow cytometric technique is high when instrumentation is guided by the biological standard Plasmodium berghei.


Subject(s)
Laboratories , Micronuclei, Chromosome-Defective/ultrastructure , Reticulocytes/ultrastructure , Animals , Flow Cytometry , Male , Mice , Mice, Inbred BALB C , Reference Standards , Reproducibility of Results
10.
J Abnorm Psychol ; 105(2): 220-31, 1996 May.
Article in English | MEDLINE | ID: mdl-8723003

ABSTRACT

The aim of the present research was to test the utility of a stress-coping model of postpartum depression. Data were collected during the last trimester of pregnancy (n = 197) and twice after the birth (4 weeks, n = 180, and approximately 5 months, n = 163). Coping resources and depressive symptomatology were assessed at Time 1, stress and coping were assessed at Time 2, and depressive symptomatology and partner ratings of coping effectiveness were assessed at Times 2 and 3. After control of the effects of initial depression, there was evidence of significant effects of levels of stress and coping responses on the Time 2 and Time 3 outcome measures. There were also some evidence linking coping resources (particularly self-esteem and family support) to postpartum depressive symptomatology.


Subject(s)
Adaptation, Psychological , Depression, Postpartum/psychology , Mothers/psychology , Stress, Psychological/psychology , Adolescent , Adult , Depression, Postpartum/diagnosis , Female , Humans , Prevalence , Prospective Studies
11.
Am J Surg ; 151(5): 581-4, 1986 May.
Article in English | MEDLINE | ID: mdl-3706634

ABSTRACT

The accuracy of mechanism of injury criteria and trauma scores as triage criteria for identifying major trauma patients has been determined from the experience at one trauma center treating 2,500 patients over a 2 year period. Death of the other occupant of the same vehicle as the patient and patient extrication taking longer than 20 minutes were determined to be sufficiently accurate triage criteria. Trauma scores of 14 or less were more accurate than trauma scores of 12 or less.


Subject(s)
Emergency Medical Services , Triage , Wounds and Injuries/diagnosis , Accidents, Home , Accidents, Traffic , Aged , Emergencies , Female , Humans , Male , Retrospective Studies , Wounds and Injuries/classification
12.
Am J Surg ; 153(5): 473-8, 1987 May.
Article in English | MEDLINE | ID: mdl-3578669

ABSTRACT

During a 4 1/2 year period, 4,941 trauma patients were admitted to a hospital, and details of their injuries and treatment were entered in a computerized trauma registry. Using that database, patients with cervical spine injury were studied. Of the 4,941 patients, 1,823 (38 percent) had radiographs of the cervical spine. Ninety-four patients (5 percent) of these patients had injuries of the cervical spine or spinal cord. Sixty five of the 94 patients with cervical spine injury were alert. All had either neck pain or neck tenderness. We do not recommend screening cervical spine radiographs for the alert trauma patient without neck pain; however, we do recommend screening for all patients with decreased levels of consciousness and an injury that could have conceivably injured the cervical spine, for all patients with neurologic deficits compatible with a cervical origin, and for all patients with neck pain or tenderness. Lateral cervical spine radiographs were obtained in all injured patients. They demonstrated cervical spine injury in 70 patients (74 percent) and missed the injury in the remaining 24, which resulted in an unacceptable false-negative rate of 26 percent. We believe that all patients at risk for cervical spine injuries must have complete radiographic examinations of the cervical spine. Computerized axial tomography was the most useful modality to confirm a cervical spine injury in those patients whose lateral cervical spines appeared normal radiographically, especially in patients with associated head injury requiring computerized axial tomography of the brain. Computerized axial tomography diagnosed the injury in 14 of the 24 patients requiring study beyond initial screening. Also presented herein is a radiologic screening algorithm for cervical spine injuries in trauma patients.


Subject(s)
Cervical Vertebrae/injuries , Fractures, Bone/diagnostic imaging , Spinal Cord Injuries/diagnostic imaging , Accidents, Traffic , Brain Injuries/diagnostic imaging , Cervical Vertebrae/diagnostic imaging , Humans , Ligaments/injuries , Quadriplegia/etiology , Registries , Tomography, X-Ray Computed
13.
Res Vet Sci ; 43(2): 243-8, 1987 Sep.
Article in English | MEDLINE | ID: mdl-3685638

ABSTRACT

The concentration of total plasma bile acids was measured in normal sheep and in sheep in which liver damage was induced by chronic copper poisoning, ligated bile ducts or induced ketosis. All three treatments produced a rise in total bile acid concentration in plasma which was proportional to the degree of hepatic damage seen histologically and which tended to parallel changes in activity of iditol, and glutamate dehydrogenase and aspartate amino-transferase in plasma. Plasma bile acid concentration was a more sensitive method of detecting these types of liver damage than was the measurement of total plasma bilirubin concentration, and could be used to assess alterations in liver function in sheep.


Subject(s)
Bile Acids and Salts/blood , Liver Diseases/veterinary , Sheep Diseases/blood , Animals , Bile Ducts , Copper/poisoning , Female , Ketosis/complications , Ketosis/veterinary , Ligation , Liver Diseases/blood , Liver Diseases/etiology , Sheep
16.
Eur J Biochem ; 230(1): 3-16, 1995 May 15.
Article in English | MEDLINE | ID: mdl-7601114

ABSTRACT

Many proteins in the cell require assistance from molecular chaperones at stages in their life cycles in order to attain correctly folded states and functional conformations during protein synthesis or during recovery from denatured states. A recently discovered molecular chaperone, which is abundant in the eukaryotic cytosol and is called the chaperonin containing TCP-1 (CCT), has been shown to assist the folding of some proteins in cytosol. This chaperone is a member of the chaperonin family which includes GroEL, 60-kDa heat shock protein (Hsp60), Rubisco subunit binding protein (RBP) and thermophilic factor 55 (TF55), but is distinct from the other members in several respects. Presently the most intriguing feature is the hetero-oligomeric nature of the CCT; at least eight subunit species which are encoded by independent and highly diverged genes are known. These genes are calculated to have diverged around the starting point of the eukaryotic lineage and they are maintained in all eukaryotes investigated, suggesting a specific function for each subunit species. The amino acid sequences of these subunits share approximately 30% identity and have some highly conserved motifs probably responsible for ATPase function, suggesting this function is common to all subunits. Thus, each subunit is thought to have both specific and common functions. These observations, in conjunction with biochemical and genetic analysis, suggest that CCT functions as a very complex machinery for protein folding in the eukaryotic cell and that its chaperone activity may be essential for the folding and assembly of various newly synthesized polypeptides. This complex behaviour of CCT may have evolved to cope with the folding and assembly of certain highly evolved proteins in eukaryotic cells.


Subject(s)
Chaperonins , Molecular Chaperones/chemistry , Protein Folding , Amino Acid Sequence , Animals , Chaperonin Containing TCP-1 , Cytosol/chemistry , Humans , Molecular Chaperones/genetics , Molecular Chaperones/physiology , Molecular Sequence Data
17.
Curr Opin Lipidol ; 12(3): 321-7, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11353336

ABSTRACT

Since the discovery of leptin in 1994, a considerable amount of research has focused on leptin as a central regulator of body weight. In the animal model, research has demonstrated leptin action through hypothalamic centres altering both satiety and energy expenditure. In contrast to animal studies, it is unlikely that leptin functioning in the human system exerts such a profound role in body weight regulation. Human studies suggest that leptin levels are strongly correlated with both percentage fat mass and body mass index, in accordance with the proposed 'lipostatic theory'. Current research suggests the existence of a unique inter-relationship between dietary fat, leptin expression and leptin action within the peripheral system. More specifically, it has been demonstrated that polyunsaturated fatty acid (PUFA) intake influences adipose tissue expression of leptin, and of several lipogenic enzymes and transcription factors. In addition, leptin stimulates triglyceride depletion in white adipose tissue without increasing free fatty acid release, thus favouring fatty acids versus glucose as a fuel source. Recent studies suggest that the reduction in adipose hypertrophy observed with n-3 PUFA-containing fish oil feeding might involve a leptin-specific process. A large amount of evidence supports direct functioning of leptin in peripheral lipid metabolism in vivo and in vitro. It is possible that PUFAs will maintain an efficient level of circulating leptin, thus preventing leptin insensitivity and weight gain. There has been much recent progress in clinical leptin research, from energy expenditure to leptin analogue efficacy; the purpose of the present review is to summarize our current understanding of leptin functioning.


Subject(s)
Leptin/metabolism , Leptin/physiology , Lipid Metabolism , Adipose Tissue/metabolism , Animals , Dietary Fats/metabolism , Fatty Acids, Unsaturated/metabolism , Humans , Obesity/metabolism
18.
J Biol Chem ; 275(25): 18985-94, 2000 Jun 23.
Article in English | MEDLINE | ID: mdl-10748209

ABSTRACT

The chaperonin containing TCP-1 (CCT) of eukaryotic cytosol is composed of eight different subunit species that are proposed to have independent functions in folding its in vivo substrates, the actins and tubulins. CCT has been loaded with (35)S-beta-actin by in vitro translation in reticulocyte lysate and then subjected to immunoprecipitation with all eight anti-CCT subunit antibodies in mixed micelle buffers, conditions that disrupt CCT into its constituent monomers. Interactions between (35)S-beta-actin and isolated CCTalpha, CCTbeta, CCTepsilon, or CCTtheta subunits are observed, suggesting that polar and electrostatic interactions may mediate actin binding to these four CCT subunits. Additionally, a beta-actin peptide array was screened for CCT-binding sequences. Three regions rich in charged and polar amino acid residues, which map to the surface of native beta-actin, are implicated in interactions between actin and CCT. Several of these biochemical results are consistent with the recent cryo-electron microscopy three-dimensional structure of apo-CCT-alpha-actin, in which alpha-actin is bound by the apical domains of specific CCT subunits. A model is proposed in which actin interacts with several CCT subunits during its CCT-mediated folding cycle.


Subject(s)
Actins/metabolism , Chaperonins/metabolism , Cytosol/metabolism , Actins/chemistry , Amino Acid Sequence , Animals , Binding Sites , Chaperonin Containing TCP-1 , Chaperonins/chemistry , Chaperonins/genetics , Mice , Models, Molecular , Molecular Sequence Data , Mutagenesis , Protein Conformation
19.
FASEB J ; 10(1): 137-47, 1996 Jan.
Article in English | MEDLINE | ID: mdl-8566534

ABSTRACT

The chaperonin-containing TCP-1 (CCT), found in the eukaryotic cytosol, is currently the focus of extensive research, CCT isolated from mouse testis lysate sediments at 20S in a sucrose gradient and accounts for about 70% of the total protein in this fraction. We intend to identify all the other proteins that copurify with CCT and to compile a reference profile for future studies. Their identification can be accelerated by a combination of protease digestion, matrix-assisted laser desorption-mass spectrometry, and database matching known as peptide mass fingerprinting. We applied this strategy to 32 polypeptides resolved by 2-dimensional gel electrophoresis, and 23 known proteins and 6 novel proteins were identified. We analyzed isoelectric variants of the CCT subunits and differences in the peptide mass spectra of two CCT theta isoforms indicated a novel posttranslational modification of this subunit.


Subject(s)
Chaperonins/chemistry , Peptide Mapping/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Testis/chemistry , Amino Acid Sequence , Animals , Chaperonin Containing TCP-1 , Databases, Factual , Electrophoresis, Gel, Two-Dimensional , Genetic Variation , Isoelectric Point , Male , Mice , Molecular Chaperones/chemistry , Molecular Sequence Data , Molecular Weight , Protein Folding , Protein Processing, Post-Translational
20.
Mutagenesis ; 17(1): 15-23, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11752229

ABSTRACT

A single laser flow cytometric procedure to quantify micronucleus frequency in rat and mouse peripheral blood was evaluated. Reticulocytes express the transferrin receptor (also known as the CD71-defined antigen). When combined with a DNA stain, antibodies against this antigen can be used to differentially label and quantify micronucleated reticulocytes. The object of this study was to evaluate the method for rat and mouse peripheral blood using flow cytometry and compare the results obtained between two laboratories (GlaxoWellcome and Litron Laboratories). The compounds selected were the rodent carcinogens colchicine, urethane and acetaldehyde. Colchicine gives a positive response in the rat bone marrow micronucleus assay and an inconclusive result in the rat peripheral blood micronucleus assay. The latter two are both established rat carcinogens readily detected in both the bone marrow and peripheral blood micronucleus assays. In these experiments both rat and mice were treated with either colchicine or urethane and rats alone treated with acetaldehyde. After a single treatment, repeat sampling of peripheral blood was made at 0, 24, 48 and 72 h. Replicate blood samples were obtained and fixed for flow cytometric analysis at both facilities. The micronucleated reticulocyte frequency of each blood sample was determined by analysing 20 000 total reticulocytes per blood sample. The data suggest that the single laser flow cytometric procedure resulted in consistent reticulocyte and micronucleated reticulocyte frequencies between laboratories. Furthermore, these flow cytometric data compare favourably with previously published data.


Subject(s)
Acetaldehyde/toxicity , Blood Cells/drug effects , Bone Marrow Cells/drug effects , Carcinogens/toxicity , Colchicine/toxicity , Flow Cytometry/methods , Micronucleus Tests/methods , Receptors, Transferrin/blood , Reticulocytes/drug effects , Urethane/toxicity , Animals , Blood Cell Count/instrumentation , Blood Cell Count/methods , Cyclophosphamide/pharmacology , Flow Cytometry/instrumentation , Fluorescein-5-isothiocyanate/analysis , Fluorescent Dyes/analysis , Lasers , Male , Mice , Organ Specificity , Rats , Rats, Wistar , Reproducibility of Results , Reticulocytes/chemistry
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