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1.
Osteoporos Int ; 33(4): 937-941, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34825920

RESUMO

Multiple myeloma (MM) remains incurable. Although early diagnosis improves outcomes, it has been unclear which populations to target for screening with serum electrophoresis, serum free light chains and urine electrophoresis. Here, we assessed the value of MM screening in a Fracture Liaison Service, finding that 1 per 195 fragility fractures has undiagnosed MM, which can be expedited to Haematology Services. PURPOSE: A key role of the Fracture Liaison Service (FLS) is screening for secondary causes of osteoporosis. In 2019, the Royal Osteoporosis Society recommended that all patients attending FLS who are recommended anti-osteoporosis therapy have universal screening for myeloma based on serum electrophoresis, serum free light chains and urine electrophoresis. Here, we examined the impact of universal myeloma screening within an FLS. METHODS: We sampled all patients seen by the Oxfordshire FLS between January and April 2018. The completion rates and outcomes of screening were checked using the hospital and FLS databases. RESULTS: Of 950 patients identified by the FLS, 628 were eligible for MM screening; 473 (75%) of these were female, and the average age was 78.4 years. Overall, 584 had some form of myeloma screening, of which 577 (92%) had serum electrophoresis, 525 (84%) had serum free light chains and 407 (65%) had urine electrophoresis measured. A total of 327 (59%) patients had complete screening. Three patients (0.5%) had newly diagnosed myeloma and were urgently referred to Haematology Services. Furthermore, 46 (8%) patients had a detectable serum paraprotein with a likely diagnosis of monoclonal gammopathy of uncertain significance (MGUS) and referred for community annual surveillance according to local guidelines. CONCLUSION: Addition of universal myeloma screening to laboratory testing identified myeloma in 1 per 195 patients, and its precursor state MGUS in 1 per 13 patients, which may have otherwise been missed. Further analysis with long-term follow-up is needed to clearly define the value of diagnosing MGUS within the FLS setting and establish the benefits vs. costs and methods to improve screening completion rates.


Assuntos
Gamopatia Monoclonal de Significância Indeterminada , Mieloma Múltiplo , Osteoporose , Fraturas por Osteoporose , Idoso , Atenção à Saúde , Feminino , Humanos , Mieloma Múltiplo/complicações , Mieloma Múltiplo/diagnóstico , Osteoporose/epidemiologia , Fraturas por Osteoporose/diagnóstico , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/etiologia , Prevenção Secundária
2.
Brain Behav Immun ; 27(1): 155-61, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23085145

RESUMO

Chemotherapy has been known to cause severe side effects, including fatigue. While the mechanisms for chemotherapy induced fatigue (CIF) are likely to be multi-factorial in origin, it is thought that inflammation and anemia may play a role. The purpose of this study was to examine the effect of chemotherapy on fatigue in mice, and further, to begin to determine if inflammation and anemia may contribute to this response. For experiment 1, C57BL/6 mice were assigned to: vehicle (PBS), low (20 mg/kg), medium (40 mg/kg), or high (60 mg/kg) doses of 5-fluorouracil (5-FU). Voluntary physical activity (PA) was measured throughout the treatment period (day 1-5) as well as during the recovery period (day 6-14). In experiment 2, we examined the effects of 5-FU (60 mg/kg) on the inflammatory mediator MCP-1 and on markers of anemia (RBC, Hct and Hb). Finally, using MCP-1(-/-) mice we examined the role of MCP-1 on CIF (experiment 3). 5-FU reduced voluntary PA in a dose response manner (p<0.05). Plasma MCP-1 was increased following 5-FU treatment on both days 5 (p=0.10) and 14 (p<0.05). In addition, RBCs, Hct and Hb were reduced with 5-FU on days 5 and 14 (p<0.05). Both C57BL/6 and MCP-1(-/-) mice saw similar decrements in PA through the duration of the treatment period (days 1-5), however the MCP-1(-/-) mice recovered much earlier than wildtype mice. This study provides evidence of the dose response effect of a standard chemotherapy agent on fatigue and demonstrates a potential role of MCP-1 and presumably inflammation, and anemia.


Assuntos
Anemia/etiologia , Antimetabólitos Antineoplásicos/efeitos adversos , Quimiocina CCL2/imunologia , Fadiga/etiologia , Fluoruracila/efeitos adversos , Atividade Motora/imunologia , Animais , Antimetabólitos Antineoplásicos/imunologia , Quimiocina CCL2/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fadiga/imunologia , Feminino , Fluoruracila/imunologia , Inflamação/etiologia , Inflamação/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Atividade Motora/efeitos dos fármacos
3.
Clin Med (Lond) ; 7(5): 496-500, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17990720

RESUMO

Pain is under-recognised and under-treated in older people. It is a subjective, personal experience, only known to the person who suffers. The assessment of pain is particularly challenging in the presence of severe cognitive impairment, communication difficulties or language and cultural barriers. These guidelines set out the key components of assessing pain in older people, together with a variety of practical scales that may be used with different groups, including those with varying levels of cognitive or communication impairment. The purpose is to provide professionals with a set of practical skills to assess pain as the first step towards its effective management. The guidance has implications for all healthcare and social care staff and can be applied in all settings, including the older person's own home, in care homes, and in hospital.


Assuntos
Transtornos Cognitivos , Cognição , Avaliação Geriátrica , Dor/diagnóstico , Percepção , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Comunicação , Humanos , Dor/fisiopatologia , Dor/psicologia , Medição da Dor , Relações Médico-Paciente , Guias de Prática Clínica como Assunto
4.
Ecology ; 88(7): 1634-40, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17645009

RESUMO

Detecting habitat selection depends on the spatial scale of analysis, but multi-scale studies have been limited by the use of a few, spatially variable, hierarchical levels. We developed spatially explicit approaches to quantify selection along a continuum of scales using spatial (coarse-graining) and geostatistical (variogram) pattern analyses at multiple levels of habitat use (seasonal range, travel routes, feeding areas, and microsites). We illustrate these continuum-based approaches by applying them to winter habitat selection by woodland caribou (Rangifer tarandus caribou) using two key habitat components, Cladina lichens and snow depth. We quantified selection as the reduction in variance in used relative to available sites, thus avoiding reliance on correlations between organism and habitat, for which interpretation can be impeded by cross-scale correlations. By consistently selecting favorable habitat features, caribou experienced reduced variance in these features. The degree to which selection was accounted for by the travel route, feeding area, or microsite levels varied across the scale continuum. Caribou selected for Cladina within a 13-km scale domain and selected shallower snow at all scales. Caribou responded most strongly at the dominant scales of patchiness, implicating habitat heterogeneity as an underlying cause of multi-scale habitat selection. These novel approaches enable a spatial understanding of resource selection behavior.


Assuntos
Comportamento Animal , Ecossistema , Rena/fisiologia , Comportamento Espacial , Animais , Líquens/fisiologia , Estações do Ano , Neve
5.
Neuropeptides ; 39(3): 191-9, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15944011

RESUMO

The neuropeptide galanin is present at high levels within the dorsal root ganglia (DRG) and spinal cord during development and after peripheral nerve damage in the adult. This pattern of expression suggests that it may play a role in the adaptive response of the peripheral nervous system (PNS) to injury. Several experimental paradigms have demonstrated that galanin modulates pain transmission, particularly after nerve injury. In our laboratory we have used a transgenic approach to further elucidate the functions of galanin within the somatosensory system. We have generated mice which over-express galanin (either inducibly after nerve injury, or constitutively), and knock-out (KO) mice, in which galanin is absent in all cells, throughout development and in the adult. Analysis of the nociceptive behaviour of the galanin over-expressing animals, before and after nerve injury, supports the view that galanin is an inhibitory neuromodulator of spinal cord transmission. In apparent contradiction to these findings, galanin KO animals fail to develop allodynia and hyperalgesia after nerve injury. However, further studies have shown that galanin is critical for the developmental survival of a subset of small diameter, unmyelinated sensory neurons that are likely to be nociceptors. This finding may well explain the lack of neuropathic pain-like behaviour after injury in the KO animals. Furthermore, the developmental survival role played by galanin is recapitulated in the adult where the peptide is required for optimal neuronal regeneration after injury, and in the hippocampus where it plays a neuroprotective role after excitotoxic injury.


Assuntos
Galanina/genética , Regeneração Nervosa/fisiologia , Neuralgia/fisiopatologia , Sistema Nervoso Periférico/lesões , Sistema Nervoso Periférico/fisiologia , Animais , Galanina/metabolismo , Camundongos , Camundongos Knockout , Camundongos Transgênicos
6.
Neuroscience ; 101(1): 141-55, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11068143

RESUMO

The formation of covalent isopeptide cross-links between cell surface protein molecules by the enzyme transglutaminase C influences cell adhesion and morphology. Retinoid-inducible cross-linking activity associated with this enzyme is present in the developing rat cerebellar cortex [Perry M. J. M. et al. (1995) Neuroscience 65, 1063-1076]. A monoclonal antibody was used to localize transglutaminase C to granule neurons in the developing cerebellar cortex. The enzyme was inducible by retinoic acid both in granule neurons cultured from postnatal rat cerebellar cortex and in cells of the embryonic dorsal rhombic lip, which contain granule neuron precursors. A possible biological function for transglutaminase activity was investigated in living granule neurons, cultured on a biomatrix substratum, studied by time-lapse cinematographic analysis using the transglutaminase inactivator RS-48373-007. Inhibition of cross-linking activity did not influence the number of neurites formed by granule neurons, but caused the destabilization of neurites during the initial outgrowth period, seen as an increase in the number of growth cone retractions and the onset of premature axon collateral formation (bifurcation). Inactivation of cross-linking activity prevented the formation of fascicles between neurites only when cells were cultured on a biomatrix surface. Two glial proteins involved in cell-extracellular matrix interactions, midkine and galectin-3, were identified as putative substrates for granule neuron transglutaminase. The results suggest that covalent cross-link formation by transglutaminase C or a related enzyme generates multimeric molecular forms of glial-derived proteins, and plays a role in stabilizing newly formed neurites. A possible non-pathological role for transglutaminase in the control of axon collateral branching by developing granule neurons in the cerebellar cortex is discussed.


Assuntos
Antígenos de Diferenciação/metabolismo , Proteínas de Transporte/metabolismo , Diferenciação Celular/efeitos dos fármacos , Córtex Cerebelar/embriologia , Córtex Cerebelar/crescimento & desenvolvimento , Citocinas , Proteínas de Ligação ao GTP/metabolismo , Neuritos/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Transglutaminases/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Diferenciação Celular/fisiologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Células Cultivadas , Córtex Cerebelar/citologia , Córtex Cerebelar/enzimologia , Reagentes de Ligações Cruzadas/metabolismo , Reagentes de Ligações Cruzadas/farmacologia , Feminino , Galectina 3 , Cones de Crescimento/efeitos dos fármacos , Cones de Crescimento/enzimologia , Cones de Crescimento/ultraestrutura , Camundongos , Camundongos Endogâmicos BALB C , Midkina , Neuritos/enzimologia , Neuritos/ultraestrutura , Neuroglia/citologia , Neuroglia/efeitos dos fármacos , Neuroglia/enzimologia , Neurônios/citologia , Neurônios/enzimologia , Gravidez , Proteína 2 Glutamina gama-Glutamiltransferase , Tretinoína/metabolismo , Tretinoína/farmacologia
7.
Proc Natl Acad Sci U S A ; 97(21): 11563-8, 2000 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-11016970

RESUMO

The neuropeptide galanin is expressed developmentally in the dorsal root ganglion (DRG) and is rapidly up-regulated 120-fold after peripheral nerve section in the adult. Here we report that adult mice carrying a loss-of-function mutation in the galanin gene have a 13% reduction in the number of cells in the DRG associated with a 24% decrease in the percentage of neurons that express substance P. These deficits are associated with a 2.8- and 2.6-fold increase in the number of apoptotic cells in the DRG at postnatal days 3 and 4, respectively. After crush injury to the sciatic nerve, the rate of peripheral nerve regeneration is reduced by 35% with associated long-term functional deficits. Cultured DRG neurons from adult mutant mice demonstrate similar deficits in neurite number and length. These results identify a critical role for galanin in the development and regeneration of sensory neurons.


Assuntos
Galanina/fisiologia , Regeneração Nervosa , Neurônios Aferentes/citologia , Neurônios Aferentes/fisiologia , Animais , Axônios , Galanina/genética , Camundongos , Camundongos Knockout
8.
Proc Natl Acad Sci U S A ; 97(21): 11569-74, 2000 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-11016971

RESUMO

The neuropeptide galanin colocalizes with choline acetyltransferase, the synthetic enzyme for acetylcholine, in a subset of cholinergic neurons in the basal forebrain of rodents. Chronic intracerebroventricular infusion of nerve growth factor induces a 3- to 4-fold increase in galanin gene expression in these neurons. Here we report the loss of a third of cholinergic neurons in the medial septum and vertical limb diagonal band of the basal forebrain of adult mice carrying a targeted loss-of-function mutation in the galanin gene. These deficits are associated with a 2-fold increase in the number of apoptotic cells in the forebrain at postnatal day seven. This loss is associated with marked age-dependent deficits in stimulated acetylcholine release, performance in the Morris water maze, and induction of long-term potentiation in the CA1 region of the hippocampus. These data provide unexpected evidence that galanin plays a trophic role to regulate the development and function of a subset of septohippocampal cholinergic neurons.


Assuntos
Sobrevivência Celular/fisiologia , Galanina/fisiologia , Neurônios/citologia , Prosencéfalo/citologia , Receptores Colinérgicos/metabolismo , Animais , Potenciais Pós-Sinápticos Excitadores , Feminino , Galanina/genética , Potenciação de Longa Duração , Camundongos , Neurônios/metabolismo , Neurônios/fisiologia , Prosencéfalo/metabolismo , Prosencéfalo/fisiologia
9.
J Urol ; 162(5): 1674-6, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10524895

RESUMO

PURPOSE: Pubovaginal sling is gaining widespread acceptance as a primary form of treatment for types II and III stress urinary incontinence. However, a major drawback is postoperative obstructed voiding due to excessive force placed on the suspension suture. We describe a simple objective method for intraoperative adjustment of sling tension that can be performed by a single surgeon during pubovaginal sling surgery. MATERIALS AND METHODS: A cotton swab is inserted into the urethra and placed at the urethrovesical junction after the sling is fixed suburethrally and the vaginal mucosa is closed. The suspension sutures are tied down directly onto the rectus fascia with enough tension to keep the cotton swab angle between 0 and 10 degrees to the horizontal plane. A total of 29 patients with an average age of 62 years underwent pubovaginal sling surgery with rectus and cadaveric fascia using this technique for tension adjustment. Of the patients 21 were diagnosed with types II and III, 5 had type II only and 3 had type III only incontinence. Preoperative evaluation revealed detrusor instability in 5 patients. Mean postoperative indwelling catheterization period was 6.2 days. Average followup was 15.6 months. RESULTS: To date no permanent urinary retention has occurred. Of the patients 15 voided without difficulty after catheter removal, 13 had urinary difficulty requiring intermittent catheterization for 1 week or less and 1 had retention requiring intermittent catheterization for 10 weeks. Preoperative symptoms of detrusor instability resolved in all cases. De novo detrusor instability in 3 cases was controlled with anticholinergics. CONCLUSIONS: Overzealous sling tension adjustment has been recognized as a cause of treatment failure leading to urethral obstruction. Our technique is effective in preventing over adjustment of tension, is reproducible and can be performed by 1 surgeon.


Assuntos
Incontinência Urinária/cirurgia , Procedimentos Cirúrgicos Urológicos/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Urológicos/instrumentação
10.
J Urol ; 162(3 Pt 1): 832-40, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10458391

RESUMO

PURPOSE: Loss of bladder compliance from hypercontractility and fibrosis may represent an injury response to excessive intravesical pressure. Together, interactions between cell and extracellular matrix components regulate cell response to injury and extracellular matrix remodeling. The receptor for hyaluronic acid mediated motility (RHAMM) is a recently described hyaluronic acid binding protein known to influence multiple types of cell extracellular matrix interaction in development, injury and cancer. We evaluate the role of RHAMM in mediating early events in bladder stretch injury. MATERIALS AND METHODS: An acute stretch injury model was used. The rat bladder was injured by hydrodistention inducing gross hematuria. Tissues were analyzed for temporal and spatial expression of RHAMM in the mucosa and detrusor regions by immunostaining, western and reverse transcriptase polymerase chain reaction analyses. The contractile activity of smooth muscle cell primary cultures was analyzed using a gel contraction assay in the presence of peptide fragments known to block RHAMM function. RESULTS: Acute hydrodistention caused immediate and significant injury to the bladder, with fracturing of smooth muscle cell bundles, edema and hemorrhage. RHAMM immunolocalized to the mucosa and detrusor within 2 hours of injury, peaking by 5 to 10 hours. A shift from low molecular weight (55 kD.) to high (120 kD.) receptor isoforms was prominent during the peak expression period noted by immunolocalization. RHAMM messenger ribonucleic acid increased only slightly (40%) by 5 hours after injury. Smooth muscle cell primary cultures actively initiated and maintained the contraction of collagen gels by more than 75% of baseline in vitro. Blocking RHAMM function significantly inhibited the ability to less than 25% of smooth muscle cells to contract the gels in vitro. CONCLUSIONS: Increased expression of RHAMM is an early event precipitated by stretch injury to the bladder. Since extracellular matrix hyaluronic acid is found early in tissue repair responses, its receptor RHAMM may be mediating initial bladder responses to stretch injury, some of which (contraction) may be experimentally blocked in vitro. Since the receptor directly regulates protein kinase signaling which in turn mediates smooth muscle cell contraction and collagen synthesis, further studies of RHAMM function in bladder pathology are warranted.


Assuntos
Proteínas da Matriz Extracelular/fisiologia , Receptores de Hialuronatos/fisiologia , Ácido Hialurônico/fisiologia , Contração Muscular/fisiologia , Músculo Liso/citologia , Músculo Liso/lesões , Bexiga Urinária/fisiologia , Animais , Divisão Celular , Células Cultivadas , Feminino , Músculo Liso/fisiopatologia , Ratos , Ratos Sprague-Dawley
11.
Mol Ecol ; 8(8): 1309-15, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10447871

RESUMO

Moose, Alces alces, occur naturally throughout most of Canada but successful introductions of known numbers of animals have been made to the islands of Newfoundland and Cape Breton. Five microsatellite loci were used to investigate the population genetic structure and any change in genetic variability due to founder events of moose in Canada. Comparisons of allele frequencies for moose from 11 regions of the country suggested that there are at least seven genetically distinct populations (P < 0.05) in North America, namely Alberta, eastern Ontario, New Brunswick, Cape Breton, Labrador, western Newfoundland, and the Avalon Peninsula of Newfoundland. The average population heterozygosity was approximately 33% (range from 22 to 41%). UPGMA analysis of Nei's genetic distances produced phenograms similar to what would be expected when geographical location and population history are considered. The loss of heterozygosity due to a single founder event (n = 3; two introductions and a natural colonization) ranged from 14 to 30%, and the cumulative loss of heterozygosity due to two successive founder events (an introduction followed by a natural colonization) was 46%. In these examples loss of genetic variability has not been associated with any known phenotypic deviances, suggesting that populations may be established from a small number of founders. However, the viability of these founded populations over evolutionary timescales cannot be determined and is highly dependent upon chance.


Assuntos
Cervos/genética , Efeito Fundador , Variação Genética/genética , Repetições de Microssatélites/genética , Alelos , Animais , Canadá , Análise por Conglomerados , DNA/química , Cervos/classificação , Eletroforese em Gel de Poliacrilamida/veterinária , Feminino , Masculino , Músculo Esquelético/química , Filogenia , Reação em Cadeia da Polimerase/veterinária
12.
FEBS Lett ; 450(1-2): 57-60, 1999 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-10350057

RESUMO

An enamine mechanism-based inactivator of mammalian delta-aminobutyric acid aminotransferase, 4-amino 5-fluoropentanoic acid is a potent inhibitor of cell growth and pigment formation in the cyanobacterium Synechococcus PCC 6301. It was demonstrated that 4-amino 5-fluoropentanoic acid inhibits the aminolaevulinate synthesis at glutamate 1-semialdehyde aminotransferase and that in the mutant obtained by exposing cells to 40 microM 4-amino 5-fluoropentanoic acid, this enzyme was insensitive to the inhibitor. The specific activity of glutamate 1-semialdehyde aminotransferase in cell extracts was lower in the mutant, although the cell growth rate was unaffected. The decrease in sensitivity to 4-amino 5-fluoropentanoic acid in the mutant is due to a structural gene mutation, a single base change in the hemL gene resulting in a S162T substitution in the gene product.


Assuntos
Cianobactérias/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Transferases Intramoleculares/antagonistas & inibidores , Ácidos Pentanoicos/farmacologia , Ácido Aminolevulínico/metabolismo , Divisão Celular/efeitos dos fármacos , Clorofila/metabolismo , Cianobactérias/enzimologia , Cianobactérias/genética , Resistência a Medicamentos/genética , Mutação , Análise de Sequência de DNA
13.
Med Educ ; 32(3): 289-93, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9743784

RESUMO

A randomized controlled trial was undertaken to evaluate the effectiveness of a new model for providing urban general practice attachments for final-year medical students at the Flinders University of South Australia. All the student groups in that year were randomized prospectively to either the standard student attachment, as run by the university, or to an attachment organized by a project team from a local network of general practitioners. Students in the intervention group had their personal learning goals assessed and matched with their general practice preceptors, and the students were set a task that developed their contact with other health resources in the community. Results from an evaluation questionnaire completed by the students at the end of their terms showed that the students in the intervention group rated their general practice preceptors more highly, had more contact with allied health and community organizations, felt that they had met their own learning goals to a greater extent, and enjoyed their term more. Student examination results showed that the students in the intervention group did not perform as well in one of the four areas of their end of term examination as did the students in the standard attachment. The additional cost of providing the intervention was estimated to be A$340 per student. We conclude that long-term decisions about adopting this new model of organizing general practice attachments on a wider scale will need to balance the apparent benefits against the increased resources required.


Assuntos
Educação de Graduação em Medicina , Medicina de Família e Comunidade/educação , Humanos , Estudos Prospectivos , Austrália do Sul , Serviços Urbanos de Saúde
15.
Artigo em Inglês | MEDLINE | ID: mdl-9150507

RESUMO

The hippocampus, parietal cortex, and insula were measured on volumetric magnetic resonance imaging to determine whether patients with early Alzheimer's disease had significantly more atrophy than healthy controls. To determine whether the atrophy is limited to certain cortical regions, the striate cortex was measured because this area is not usually neuropathologically involved early in Alzheimer's disease. Eight mildly to moderately impaired patients who met National Institute of Neurological Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for probable Alzheimer's disease and eight controls who matched for age, gender, and educational level were studied. Atrophy was quantified in the following regions: hippocampus, parietal cortex, insular cortex, and striate cortex. The authors found significantly more atrophy of the hippocampus (p < 0.0001), parietal cortex (p < 0.025), and insula (p < 0.003) in the Alzheimer's patients. Measures of the striate cortex did not differ between the groups. There were no significant left-right differences in any of the regions measured. Their findings show that mildly to moderately impaired Alzheimer's patients have significantly more atrophy of the hippocampus, parietal cortex, and insula than healthy age-matched controls. Furthermore, this atrophy is probably discrete because the groups did not differ on measures of the striate cortex. Selective atrophy of the parietal and insular cortices has not previously been reported using the authors' methodology on volumetric magnetic resonance imaging. Their data suggest that the insula may be involved early in Alzheimer's disease and that atrophy of the insular cortex may contribute to the cognitive deficits typical of early Alzheimer's disease.


Assuntos
Doença de Alzheimer/diagnóstico , Córtex Cerebral/patologia , Hipocampo/patologia , Imageamento por Ressonância Magnética , Lobo Parietal/patologia , Idoso , Idoso de 80 Anos ou mais , Atrofia , Mapeamento Encefálico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Valores de Referência
18.
J Mol Biol ; 264(1): 32-45, 1996 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-8950265

RESUMO

We have carried out a physical characterization of mutant repressor proteins of the trp repressor system of Escherichia coli by circular dichroism, chemical denaturation, and 8-anilino-1-naphthalenesulfonate binding. We have also probed the protein-protein interactions via fluorescence anisotropy and lifetime measurements and measured the thermodynamics of ligand (L-tryptophan) binding by isothermal titration calorimetry. Here, we present investigations of four charge change super-repressor mutants: EK13, EK18, DN46 and EK49, and compare these results with those previously obtained for wild-type trp repressor and the AV77 super-repressor mutant. These studies demonstrate that super-repressor phenotypes may result from changes in operator affinity (DN46, EK49), protein-protein interactions (EK18), as well as the coupling of folding to ligand binding (AV77, EK13, EK18). Correlations between the oligomerization behavior and cooperativity of DNA binding for some of these mutants indicate that coupling of oligomerization to DNA binding modulates operator site occupation giving rise to the super-repressor phenotype. The present results underscore the complex interplay between the multiple equilibria in this system. Moreover, they provide insights into the structural basis for the mutational perturbation of the energetics of this classical allosterically controlled transcriptional regulator.


Assuntos
Proteínas de Bactérias/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Repressoras/genética , Triptofano/genética , Naftalenossulfonato de Anilina , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Dicroísmo Circular , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Corantes Fluorescentes , Cinética , Ligantes , Modelos Moleculares , Mutação , Ligação Proteica , Conformação Proteica , Desnaturação Proteica , Estrutura Secundária de Proteína , Proteínas Repressoras/química , Proteínas Repressoras/metabolismo , Termodinâmica , Triptofano/metabolismo , Ureia
19.
Biochem Biophys Res Commun ; 224(1): 147-52, 1996 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-8694802

RESUMO

Midkine is a prominent acyl donor substrate for the protein cross-linking enzyme transglutaminase type 2 in rat brain neurons. Transglutaminase type 2 and midkine immunoreactivity are regionally colocalized in developing cerebellar cortex. Monomeric midkine is present in the embryonic dorsal rhombic lip which gives rise to the cerebellar cortex. A high-molecular weight (29-30 kDa) midkine appears during postnatal cerebellar development. The presence of the high-molecular weight midkine in cultured cerebellar cortical interneurons is dependent upon culture conditions. Transglutaminase catalyzes the calcium-dependent cross-linking of midkine predominantly into 29-30 kDa dimers. Dimer-formation of midkine in vitro and in cultured neurons is reduced in the presence of a transglutaminase inactivator. Neurons plated onto previously cross-linked midkine exhibit larger growth cones and enhanced neurite outgrowth compared to those plated onto monomeric midkine alone.


Assuntos
Proteínas de Transporte/metabolismo , Córtex Cerebelar/fisiologia , Citocinas , Neuritos/fisiologia , Neurônios/fisiologia , Transglutaminases/metabolismo , Envelhecimento/metabolismo , Animais , Proteínas de Transporte/química , Proteínas de Transporte/isolamento & purificação , Células Cultivadas , Córtex Cerebelar/embriologia , Córtex Cerebelar/crescimento & desenvolvimento , Reagentes de Ligações Cruzadas/farmacologia , Embrião de Mamíferos , Desenvolvimento Embrionário e Fetal , Gânglios Espinais/citologia , Gânglios Espinais/fisiologia , Cobaias , Humanos , Isoenzimas/metabolismo , Fígado/enzimologia , Substâncias Macromoleculares , Midkina , Neuritos/efeitos dos fármacos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Ratos , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo
20.
Am J Gastroenterol ; 90(11): 1965-8, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7485001

RESUMO

OBJECTIVES: Determine sensitivity and specificity of a new urease reagent strip (URS) test for detection of Helicobacter pylori in gastric biopsy specimens. METHODS: Six paired biopsy specimens were obtained from the greater curvature of the distal antrum, the lesser curvature near the incisura, and the corpus along the greater curvature during 66 procedures on 59 patients with endoscopic findings of gastric antral mucosal erythema or erosions, or gastric or duodenal ulcers. One biopsy from each site was tested with the URS. The second was evaluated with histology. A final antral biopsy was evaluated with a urea/gel test. RESULTS: Twenty-eight of the 66 cases were histologically positive, with H. pylori observed in at least one of the three biopsy sites. The URS test correctly identified all 28. Of 193 individual biopsy specimens, 78 were positive for H. pylori. The URS correctly identified 77. Sensitivity was 0.99, specificity 0.95, positive predictive value 0.93, negative predictive value 0.99, and kappa 0.92. Average time to positive was 20 min. Twenty-seven antral biopsies were histologically positive for H. pylori. The URS test correctly identified all 27, whereas the urea/gel test correctly identified 21. For antral sites, URS sensitivity was 1.00 and specificity 0.95 versus urea/gel test sensitivity of 0.75 and specificity of 1.00. CONCLUSIONS: In this sample, the URS test is as accurate as histology in diagnosing H. pylori infections, and it provides results in less time and at a lower cost than histology.


Assuntos
Mucosa Gástrica/microbiologia , Infecções por Helicobacter/diagnóstico , Helicobacter pylori/isolamento & purificação , Fitas Reagentes , Urease/análise , Técnicas Bacteriológicas , Biópsia , Estudos de Avaliação como Assunto , Mucosa Gástrica/patologia , Helicobacter pylori/enzimologia , Humanos , Valor Preditivo dos Testes , Antro Pilórico/patologia , Sensibilidade e Especificidade , Manejo de Espécimes , Estômago/patologia , Fatores de Tempo
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