RESUMO
Methane mitigation in dairy cows is an essential part of combating global warming. Governments and consumers have become increasingly interested in herbage-based feeding, and premium prices are often paid for these types of dairy products. However, this feeding strategy is presumed to produce more methane per unit of feed or milk than corn silage- or concentrate-based diets due to higher fiber intakes. Immature herbage is preferred to maintain dairy cow performance, but the high content of N and digestible fiber may increase methane and urine N emissions compared with more mature herbage. Tannin-containing feeds, such as vine leaves (Vitis vinifera), may help to combat the emissions associated with feeding immature herbage. Our study aimed to evaluate differences between early-stage (ES; 21 d of regrowth) versus late-stage (LS; 42 d) herbage and the effects of vine leaves on methane and nitrogenous emissions and the milk fatty acid profile of dairy cows. Twenty-four mid- to late-lactating dairy cows were randomized to 4 dietary groups (n = 6) in a factorial study design. Each of the 4 diets contained 69% fresh mixed legume-grass herbage, 13% grass hay, and 5% concentrate on a dry matter (DM) basis. Two diets were based on immature fresh mixed legume-grass herbage and grass hay (ES), and 2 contained more mature fresh mixed legume-grass herbage and grass hay (LS). Of these, 1 contained 13% vine leaves (VL+) and the other an additional 13% hay (VL-). No significant differences were observed in DM intake or milk yield across the diets. Methane emission intensity was lowest with ES-VL+ diets compared with LS-VL- diets (-30%; 17.1 vs. 24.5 mg/kg of energy-corrected milk). Methane yield decreased by 17% and 20% when related to the intake of DM and digested organic matter for ES-VL+ compared with LS-VL- diets (16.9 vs. 20.3 g/kg of DM intake; 23.5 vs. 29.3 g/kg of digestible organic matter). Immature grass and vine leaf addition each caused about half of the respective declines. Cows consuming any of the ES diets and the LS-VL+ diet consumed and excreted (urinary N) significantly more N than those consuming LS diets. However, when related to N intake, no differences were recorded. Unexpectedly, vine leaves did not mitigate urine N excretion; however, they lowered the n-6:n-3 ratio and increased concentrations of vaccenic and rumenic acids in both ES and LS diets. Our results demonstrate that feeding immature herbage in combination with vine leaves reduces methane yield; however, the associated high urinary N losses need to be addressed.
Assuntos
Metano , Leite , Animais , Bovinos , Dieta/veterinária , Ácidos Graxos , Feminino , Lactação , Nitrogênio , Folhas de Planta , Silagem/análise , Zea maysRESUMO
We recorded from middle lateral belt (ML) and primary (A1) auditory cortical neurons while animals discriminated amplitude-modulated (AM) sounds and also while they sat passively. Engagement in AM discrimination improved ML and A1 neurons' ability to discriminate AM with both firing rate and phase-locking; however, task engagement affected neural AM discrimination differently in the two fields. The results suggest that these two areas utilize different AM coding schemes: a "single mode" in A1 that relies on increased activity for AM relative to unmodulated sounds and a "dual-polar mode" in ML that uses both increases and decreases in neural activity to encode modulation. In the dual-polar ML code, nonsynchronized responses might play a special role. The results are consistent with findings in the primary and secondary somatosensory cortices during discrimination of vibrotactile modulation frequency, implicating a common scheme in the hierarchical processing of temporal information among different modalities. The time course of activity differences between behaving and passive conditions was also distinct in A1 and ML and may have implications for auditory attention. At modulation depths ≥ 16% (approximately behavioral threshold), A1 neurons' improvement in distinguishing AM from unmodulated noise is relatively constant or improves slightly with increasing modulation depth. In ML, improvement during engagement is most pronounced near threshold and disappears at highly suprathreshold depths. This ML effect is evident later in the stimulus, and mainly in nonsynchronized responses. This suggests that attention-related increases in activity are stronger or longer-lasting for more difficult stimuli in ML.
Assuntos
Córtex Auditivo/fisiologia , Discriminação Psicológica/fisiologia , Percepção Sonora/fisiologia , Neurônios/fisiologia , Estimulação Acústica , Potenciais de Ação , Animais , Feminino , Macaca mulatta , Masculino , Microeletrodos , Testes Neuropsicológicos , Curva ROC , Processamento de Sinais Assistido por Computador , Fatores de TempoRESUMO
PURPOSE: Early onset spinal deformities (EOSD) can be life-threatening in very young children. In the growing spine, surgical intervention is often unavoidable and should be carried out as soon as possible. A deformed section of the spine not only affects the development of the remaining healthy spine, but also that of the chest wall (which influences pulmonary function), the extremities and body balance. Posterior vertebral column resection (PVCR) represents an effective surgical solution to address such problems. However, reports in the literature concerning PVCR are mostly limited to its use in adolescents or adults. The purpose of this study was to illustrate our experience with PVCR in EOSD and to describe the surgical technique with respect to the unique anatomy of young children. MATERIALS AND METHODS: Four children [mean age 3.7 (range 2.5-5.2) years] with severe spinal deformity underwent PVCR through a single approach. Multimodal intraoperative monitoring was used in all cases. Surgery included one stage posterior circumferential resection of one vertebral body along with the adjoining intervertebral discs and removal of all posterior elements. A transpedicular screw-rod system was used for correction and stabilisation. Fusion was strictly limited to the resection site, allowing for later conversion into a growing rod construct at the remaining spine, if necessary. Relevant data were extracted retrospectively from patient charts and long spine radiographs. RESULTS: The mean operation time was 500 (range 463-541) min, with an estimated blood loss of 762 (range 600-1,050) ml. Mean follow-up time was 6.3 (range 3.5-12.4) years. After PVCR, the mean Cobb angle for scoliosis was reduced from 69° (range 50-99°) to 29° (5-44°) and the sagittal curvature (kyphosis) from 126° (87-151°) to 61° (47-75°). The mean correction of scoliosis was 57 % (18-92°) and of kyphosis, 51 % (44-62°). There were no spinal cord-related complications. In three patients, spinal instrumentation for growth guidance (fusion less growing rod technique) was applied. Two patients had complications: one patient had a complication of anesthesia, halo pin failure, and revision surgery with extension of the instrumentation cranially due to loss of correction; the second patient had a postoperative infection, which required plastic reconstructive measures. CONCLUSION: PVCR appears to be an effective technique to treat severe EOSD. There are important differences in its use in young children when compared with older patients. In patients with EOSD, additional surgical procedures are often necessary during growth, and hence non-fusion instrumentation beyond the vertebral resection site is advantageous, as it permits spinal growth and the later addition of fusion.
Assuntos
Dispositivos de Fixação Ortopédica , Procedimentos Ortopédicos/instrumentação , Procedimentos Ortopédicos/métodos , Curvaturas da Coluna Vertebral/cirurgia , Coluna Vertebral/cirurgia , Fatores Etários , Idade de Início , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Monitorização Intraoperatória , Radiografia , Estudos Retrospectivos , Curvaturas da Coluna Vertebral/diagnóstico por imagem , Fatores de Tempo , Resultado do TratamentoRESUMO
In 2006, area physicians reported increases in upper respiratory symptoms in patients living in U.S. Federal Emergency Management Agency (FEMA)-supplied trailers following Hurricanes Katrina and Rita. One potential etiology to explain their symptoms included formaldehyde; however, formaldehyde levels in these occupied trailers were unknown. The objectives of our study were to identify formaldehyde levels in occupied trailers and to determine factors or characteristics of occupied trailers that could affect formaldehyde levels. A disproportionate random sample of 519 FEMA-supplied trailers was identified in Louisiana and Mississippi in November 2007. We collected and tested an air sample from each trailer for formaldehyde levels and administered a survey. Formaldehyde levels among all trailers in this study ranged from 3 parts per billion (ppb) to 590 ppb, with a geometric mean (GM) of 77 ppb [95% confidence interval (CI): 70-85; range: 3-590 ppb]. There were statistically significant differences in formaldehyde levels between trailer types (P < 0.01). The GM formaldehyde level was 81 ppb (95% CI: 72-92) among travel trailers (N = 360), 57 ppb (95% CI: 49-65) among mobile homes (N = 57), and 44 ppb (95% CI: 38-53) among park models (N = 44). Among travel trailers, formaldehyde levels varied significantly by brand. While formaldehyde levels varied by trailer type, all types tested had some levels ≥ 100 ppb.
Assuntos
Abrigo de Emergência/estatística & dados numéricos , Exposição Ambiental/análise , Formaldeído/análise , Habitação/estatística & dados numéricos , HumanosRESUMO
Learning has been postulated to 'drive' evolution, but its influence on adaptive evolution in heterogeneous environments has not been formally examined. We used a spatially explicit individual-based model to study the effect of learning on the expansion and adaptation of a species to a novel habitat. Fitness was mediated by a behavioural trait (resource preference), which in turn was determined by both the genotype and learning. Our findings indicate that learning substantially increases the range of parameters under which the species expands and adapts to the novel habitat, particularly if the two habitats are separated by a sharp ecotone (rather than a gradient). However, for a broad range of parameters, learning reduces the degree of genetically-based local adaptation following the expansion and facilitates maintenance of genetic variation within local populations. Thus, in heterogeneous environments learning may facilitate evolutionary range expansions and maintenance of the potential of local populations to respond to subsequent environmental changes.
Assuntos
Adaptação Fisiológica , Evolução Biológica , Ecossistema , Aprendizagem , Modelos Teóricos , Animais , Variação Genética , Genótipo , Comportamento de Retorno ao Território Vital , Dinâmica PopulacionalRESUMO
Recombinant gelatins are currently evaluated as new excipients for pharmaceutical formulations. They can differ from nonrecombinant gelatins because of intentional alteration of the amino acid sequence and specific properties of the expression systems used. This may affect their solution behavior. In the present work, aqueous solutions of a histidine-containing recombinant gelatin (RG-15-His) were analyzed. Dynamic light scattering (DLS) and loss of absorbance at 200 nm upon centrifugation indicated the formation of aggregates within 1 day upon sample preparation. Static light scattering (SLS) and small-angle neutron scattering (SANS) experiments showed that the aggregate's size was > or =300 nm, and that aggregates are composed of thin, rigid rods of 37 +/- 5 nm in length. The observed aggregation was not detectable by circular dichroism (CD), Fourier transform infrared spectroscopy (FTIR), and cryo transmission electron microscopy (cryo-TEM). SANS experiments, which are not frequently used in the pharmaceutical field, provided additional morphological information about the recombinant gelatin in solution. The results show that combining SLS and SANS is a broadly applicable, complementary approach for detecting aggregation of proteins and other biomolecules and for obtaining structural information about the aggregates.
Assuntos
Gelatina/química , Difração de Nêutrons/métodos , Nêutrons , Água/química , Gelatina/análise , Luz , Difração de Nêutrons/instrumentação , Espalhamento de Radiação , Soluções , Água/análiseRESUMO
There has been considerable discussion over the last couple of years about the nature of pharmacology as a discipline and the training programmes for pharmacologists. Recently the British Pharmacological Society devoted a whole symposium to this important issue. In the UK in particular, pressure from government has nearly doubled the number of undergraduate students entering the university sector over the last five years, which has put considerable pressure on the teaching of essential practical courses for this experimental discipline. Similar pressures face the teaching of pharmacology in other countries and the situation, discussed here by Clive Page, Morley Sutter and Michael Walker, clearly has implications for academic pharmacology and the pharmaceutical industry. It is intended that the following article will stimulate both dialogue and positive action towards redressing this important problem.
Assuntos
Farmacologia/tendências , Animais , Humanos , Farmacologia/educação , Reino UnidoRESUMO
This paper describes the pharmacology of some recent cardiovascular drugs derived from plants used in Chinese traditional medicine. The groups of compounds discussed are benzylisoquinolines (several), tetrahydropyrazine (also called ligustrazine), rhynchophylline and hirsutine, ginkgolides and other PAF inhibitors, coumarins, and ginsenosides, plus a miscellaneous group; approximately 30 substances in all. The plant sources and the pharmacology are indicated for the drugs in each group. By far the most studied compounds are the benzylisoquinolines, especially tetrandrine. The types of pharmacological activity recently described for cardiovascular drugs from plants include calcium antagonism, adrenoceptor antagonism, antagonism of platelet activating factor (PAF), and the ability to act as antioxidants. Hundreds of chemicals have been isolated and identified as constituents of thousands of plants but the basic and clinical pharmacology is known for only a handful of these drugs. Much more research is needed, especially with regard to the pharmacology, both basic and clinical, of the pure chemicals derived from plants.
Assuntos
Fármacos Cardiovasculares/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Plantas Medicinais , HumanosRESUMO
The critical asthma syndrome (CAS) encompasses the most severe, persistent, refractory asthma patients for the clinician to manage. Personalized pharmacotherapy is necessary to prevent the next acute severe asthma exacerbation, not just the control of symptoms. The 2007 National Asthma Education and Prevention Program Expert Panel 3 provides guidelines for the treatment of uncontrolled asthma. The patient's response to recommended pharmacotherapy is highly variable which risks poor asthma control leading to frequent exacerbations that can deteriorate into CAS. Controlling asthma symptoms and preventing acute exacerbations may be two separate clinical activities with their own unique demands. Clinicians must be prepared to use the entire spectrum of asthma medications available but must concurrently be aware of potential drug toxicities some of which can paradoxically worsen asthma control. Medications normally prescribed for COPD can potentially be useful in the CAS patient, particularly those with asthma-COPD overlap syndrome. Immunomodulation with drugs like omalizumab in IgE-mediated asthma syndromes is one important approach. New and emerging drugs address unique aspects of airway inflammation and biology but at a significant financial cost. The pharmacology and toxicities of the agents that may be used in the treatment of CAS to control asthma symptoms and prevent severe exacerbations are reviewed.
Assuntos
Antiasmáticos/uso terapêutico , Anticorpos Anti-Idiotípicos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Asma/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Sistema Respiratório/efeitos dos fármacos , Animais , Estado Terminal , Tratamento Farmacológico/tendências , Prova Pericial , Humanos , Imunoglobulina E/imunologia , Imunoglobulina E/metabolismo , Imunomodulação , Omalizumab , Guias de Prática Clínica como Assunto , Sistema Respiratório/imunologia , SíndromeRESUMO
INTRODUCTION: Over the past decade, there has been a sharp increase in the number of newly identified synthetic drugs. These new drugs are often derivatives of previously abused substances but have unpredictable toxicity. One of these drugs is gacyclidine, a derivative of phencyclidine (PCP). Gacyclidine has been studied as a neuroprotective agent in trauma and as a therapy of soman toxicity. There are no previous reports of its use as a drug of abuse. CASE REPORTS: During a two-month period in the summer of 2013, a series of patients with severe agitation and end-organ injury were identified in an urban academic Emergency Department (ED). A urine drug of abuse screen was performed on all patients, and serum samples were sent for comprehensive toxicology analysis. A total of five patients were identified as having agitation, rhabdomyolysis, and elevated troponin (Table 1). Three of the five patients reported use of methamphetamine, and all five patients had urine drug screens positive for amphetamine. Comprehensive serum analysis identified methamphetamine in three cases, cocaine metabolites in one case, and a potential untargeted match for gacyclidine in all five cases. No other drugs of abuse were identified. DISCUSSION: This is the first series of cases describing possible gacyclidine intoxication. The possible source of the gacyclidine is unknown but it may have been an adulterant in methamphetamine as all patients who were questioned reported methamphetamine use. These cases highlight the importance of screening for new drugs of abuse when patients present with atypical or severe symptoms. Gacyclidine has the potential to become a drug of abuse both by itself and in conjunction with other agents and toxicity from gacyclidine can be severe. It is the role of the medical toxicology field to identify new agents such as gacyclidine early and to attempt to educate the community on the dangers of these new drugs of abuse.
Assuntos
Cicloexenos/toxicidade , Drogas Desenhadas/toxicidade , Drogas Ilícitas/toxicidade , Insuficiência de Múltiplos Órgãos/etiologia , Síndromes Neurotóxicas/terapia , Piperidinas/toxicidade , Psicotrópicos/toxicidade , Centros Médicos Acadêmicos , Adulto , Terapia Combinada , Cicloexenos/sangue , Cicloexenos/urina , Drogas Desenhadas/análise , Usuários de Drogas , Serviço Hospitalar de Emergência , Evolução Fatal , Feminino , Humanos , Drogas Ilícitas/sangue , Drogas Ilícitas/urina , Masculino , Pessoa de Meia-Idade , Síndromes Neurotóxicas/sangue , Síndromes Neurotóxicas/fisiopatologia , Síndromes Neurotóxicas/urina , Piperidinas/sangue , Piperidinas/urina , Agitação Psicomotora/etiologia , Psicotrópicos/sangue , Psicotrópicos/urina , Rabdomiólise/etiologia , Toxicocinética , Resultado do Tratamento , Recusa do Paciente ao TratamentoRESUMO
OBJECTIVE: To generate normative data on the Modified Card Sorting Test (M-WCST) across 11 countries in Latin America, with country-specific adjustments for gender, age, and education, where appropriate. METHOD: The sample consisted of 3,977 healthy adults who were recruited from Argentina, Bolivia, Chile, Cuba, El Salvador, Guatemala, Honduras, Mexico, Paraguay, Peru, and Puerto Rico. Each subject was administered the M-WCST as part of a larger neuropsychological battery. A standardized five-step statistical procedure was used to generate the norms. RESULTS: The final multiple linear regression models explained between 2-33% of the variance in M-WCST scores. Although t-tests showed significant differences between men and women from seven different countries on the M-WCST, the effect sizes were small. As a result, gender-adjusted norms were not generated. CONCLUSIONS: This is the first normative multicenter study conducted in in Latin America aiming to create norms for the M-WCST; this study will have important implications for the future of neuropsychology in the region.
Assuntos
Testes Neuropsicológicos/normas , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Escolaridade , Função Executiva , Feminino , Humanos , Idioma , América Latina , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Valores de Referência , Fatores Sexuais , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto JovemRESUMO
The effects of chronic treatment of spontaneously hypertensive rats (SHR) with methoxyverapamil (D 600) on blood pressure (BP) and on the in vitro contractile response of aortic and portal vein strips of rats were examined. D 600, prepared as the free base and dissolved in sesame oil, was injected subcutaneously daily into SHR to maintain the systolic blood pressure (SBP) at less than 130 mm Hg for 24 hours after injections. The dose required increased progressively from 4 to 8.5 mg/day/rat. As controls, normotensive rats (WKY) and untreated SHR received daily injections of the vehicle. After 2 weeks, aortic and portal vein strips were prepared from each rat for studies of cumulative dose-response curves to norepinephrine (NE) in Krebs' solution containing normal (2.5 mM) and low (0.2 and 0.4 mM) calcium (Ca). Chronic treatment with D 600 restored to control values the ordinarily depressed contractile response to NE and increased the ED50 values for NE (i.e., the NE dose that produces 50% of the maximum response) of aortic strips from SHR in nord-mal and low Ca. Portal veins from SHR showed increased spontaneous activity, supernormal responses to NE, and decreased ED50 values for NE that were all exaggerated by chronic D 600 treatment. These results imply that SHR developed a tolerance to D 600 associated with enhanced contractility of vascular smooth muscles.
Assuntos
Galopamil/uso terapêutico , Hipertensão/tratamento farmacológico , Verapamil/análogos & derivados , Animais , Aorta/fisiopatologia , Pressão Sanguínea , Relação Dose-Resposta a Droga , Frequência Cardíaca , Hipertensão/fisiopatologia , Técnicas In Vitro , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/fisiopatologia , Norepinefrina/farmacologia , Veia Porta/efeitos dos fármacos , Potássio/farmacologia , RatosRESUMO
A reliable method of producing physical stress in the rat was developed using heat irradiation, and the possible interaction between chronic ethanol consumption and stress was investigated in a rat model of alcoholism. Chronic heat stress and chronic ethanol consumption each produced mild hypertension in rats. When combined, the two treatments resulted in hypertension more severe than that produced by either stress or ethanol consumption alone. The group of animals receiving both treatments also exhibited high mortality. Investigations into the mechanisms responsible for the apparent additive effects of the two treatments revealed that the animals in this group had the highest circulating norepinephrine levels. The plasma volumes, however, were not different between the stressed groups and their unstressed counterparts. As the plasma norepinephrine level usually reflects overall sympathetic tone of an animal, our results suggest that the additional hypertensive effect of chronic stress on the ethanol-treated animals is associated with increased sympathetic nervous activity and is not a result of expanded plasma volume. These findings may have clinical implications for human alcoholics and in the analysis of cardiovascular risk factors in hypertensive patients.
Assuntos
Alcoolismo/complicações , Hipertensão/etiologia , Estresse Fisiológico/complicações , Alcoolismo/fisiopatologia , Animais , Dopamina/sangue , Epinefrina/sangue , Etanol/sangue , Frequência Cardíaca , Temperatura Alta , Humanos , Hipertensão/sangue , Masculino , Norepinefrina/sangue , Volume Plasmático , Ratos , Ratos Endogâmicos , Estresse Fisiológico/fisiopatologiaRESUMO
Recent experiments in the cat have demonstrated that several response parameters, including frequency tuning, intensity tuning, and FM selectivity, are spatially segregated across the isofrequency axis. To investigate whether a similar functional organization exists in the primate, we have studied the spatial distribution of pure-tone receptive field parameters across the primary auditory cortex (AI) in six owl monkeys (Aotus trivirgatus). The distributions of binaural interaction types and onset latency were also examined. Consistent with previous studies, the primary auditory cortex contained a clear cochleotopic organization. We demonstrate here that several other properties of the responses to tonal stimuli also showed nonrandom spatial distributions that were largely independent from each other. In particular, the sharpness of frequency tuning to pure tones, intensity tuning and sensitivity, response latency, and binaural interaction types all showed spatial variations that were independent from the representation of characteristic frequency and from each other. Statistical analysis confirmed that these organizations did not reflect random distributions. The overall organizational pattern of overlaying but independent functional maps that emerged was quite similar to that seen in AI of cats and, in general, appears to reflect a fundamental organization principle of primary sensory cortical fields.
Assuntos
Aotus trivirgatus/fisiologia , Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Potenciais de Ação/fisiologia , Animais , Vias Auditivas/fisiologia , Mapeamento Encefálico , Potenciais Evocados Auditivos/fisiologia , Tempo de Reação/fisiologiaRESUMO
UNLABELLED: Iodine-123-IBF is a dopaminergic antagonist suitable for SPECT imaging of D2 receptors. Initial animal studies demonstrated that its affinity for D2 receptors is approximately four times that of the commonly used SPECT D2 ligand [123I]IBZM. In this study we investigated whether this higher affinity would lead to an improved accuracy in differentiating between various extrapyramidal diseases. METHODS: SPECT imaging was performed in 17 patients with idiopathic Parkinson's syndrome (IPS); 4 patients with progressive supranuclear palsy (PSP), 2 patients with multiple system atrophy (MSA) and 7 age-matched control subjects. SPECT imaging was performed 5, 60, 120 and 180 min following intravenous bolus injection of 150-250 MBq of [123I]IBF. The ratio of ligand uptake in the basal ganglia and frontal cortex was determined as a measure of receptor status. RESULTS: In PSP and MSA patients, the basal ganglia-to-frontal cortex ratio reached a plateau at 2 hr; in the control subjects and the IPS patients the ratio was steadily increasing. At 3 hr the basal ganglia-to-frontal cortex ratio was 2.66 +/- 0.29 (control subjects), 3.01 +/- 0.41 (IPS), 2.09 +/- 0.22 (PSP) and 2.10 (MSA). In the IPS patients with predominantly one-sided symptoms, the striatum contralateral to symptoms showed a tendency towards relatively increased ligand uptake. Despite the higher affinity of IBF for the D2 receptor compared to IBZM, the separation of individual PSP and MSA patients from the control subjects was not as clear cut as reported for IBZM due to a relatively high variation in the control subjects. We hypothesize that the latter is due to imaging in nonequilibrium conditions. CONCLUSION: The data suggest that IBF-SPECT can help in discriminating extrapyramidal disease. The accuracy might be improved by an administration protocol that allows imaging in "true equilibrium" conditions, such as a bolus injection followed by a constant infusion.
Assuntos
Doenças dos Gânglios da Base/diagnóstico por imagem , Benzofuranos , Encéfalo/diagnóstico por imagem , Radioisótopos do Iodo , Pirrolidinas , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Idoso de 80 Anos ou mais , Gânglios da Base/diagnóstico por imagem , Gânglios da Base/metabolismo , Doenças dos Gânglios da Base/metabolismo , Diagnóstico Diferencial , Feminino , Lobo Frontal/diagnóstico por imagem , Lobo Frontal/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/diagnóstico por imagem , Receptores de Dopamina D2/metabolismo , Paralisia Supranuclear Progressiva/diagnóstico por imagemRESUMO
The influence of age on the mixed function oxidase system from a non-human primate was studied. Microsomes were isolated from the livers of female Macaca nemestrina ranging from 2 to 21 years of age. No significant age-related change was observed in either the cytochrome P-450 content or the NADPH cytochrome c reductase activity. In addition, the ability of the microsomes to metabolize benzo [a]pyrene did not change significantly with age. These observations contradict studies with liver tissue from laboratory rodents in which an age-related decline in the mixed function oxidase system is generally observed. The lipid composition of the liver microsomes was studied also. Both the cholesterol and total phospholipid content of the liver microsomes increased significantly with age; however, the ratio of cholesterol to phospholipid remained constant. The percentage of individual phospholipids in the microsomes changed only slightly with age. These results provide new information on the effect of age on the mixed function oxidase system and indicate that one must be cautious in extrapolating from studies with liver tissue from laboratory rodents to primates.
Assuntos
Fígado/enzimologia , Oxigenases de Função Mista/análise , Fatores Etários , Animais , Sistema Enzimático do Citocromo P-450/análise , Feminino , Fígado/análise , Macaca nemestrina , Oxirredutases/análise , Fosfolipídeos/análise , Especificidade da EspécieRESUMO
56 radial arteries were cannulated by cutdown technique in 54 critically ill infants (age (mean +/- SD) 12.2 +/- 25.9 days, weight 2710 +/- 910 g) for continuous pressure monitoring and repeated blood sampling. 30 patients survived their illness, 24 died. The mean catheterization time in the survivors was 8.1 +/- 4.1 in the non-survivors 6.9 +/- 5.6 days. Most cannulae were removed electively. 27 of the surviving infants were followed up after 10.5 +/- 5.1 months. 25 (86%) vessels were patent, 4 (14%) occluded. No trophic changes of hands or fingers were noted. We concluded that radial artery cannulation by cutdown in infants is a quick and safe technique and is suitable in patients with severe peripheral vasoconstriction.
Assuntos
Braço/irrigação sanguínea , Artérias/cirurgia , Cateterismo/métodos , Doenças do Recém-Nascido/sangue , Arteriopatias Oclusivas/etiologia , Sangria/métodos , Cateterismo/efeitos adversos , Cateteres de Demora , Seguimentos , Humanos , Lactente , Recém-NascidoRESUMO
Twenty-four children (aged 3 months to 14 years) with severe head injuries were treated by means of invasive neurointensive care for normalizing intracranial pressure (ICP) involving hyperventilation, control of body temperature, dexamethasone, barbiturates and continuous intracranial and arterial pressure monitoring. The Glasgow Coma Scale before initiation of treatment was 3-4 in 8, 5-6 in 9 and 7 in 7 patients. Moderately to severely elevated ICP was observed in 20 patients. Seven developed acute and subacute space occupying intracranial hematomas. Nineteen children (79%) survived, most often with good recovery and 5 (21%) died. Severely elevated ICP, presence of severe consumption coagulopathy and loss of components in brain auditory evoked potentials were significantly more frequent in the fatal group. We conclude that the prognosis of the severely head injured child can be improved by prompt resuscitation and aggressive neurointensive care but probably not, however, to the extent postulated in recent literature.
Assuntos
Traumatismos Craniocerebrais/terapia , Cuidados Críticos , Adolescente , Temperatura Corporal , Criança , Pré-Escolar , Dexametasona/uso terapêutico , Dopamina/uso terapêutico , Humanos , Lactente , Pressão Intracraniana , Monitorização Fisiológica , Avaliação de Processos e Resultados em Cuidados de Saúde , Fenobarbital/uso terapêutico , Terapia RespiratóriaRESUMO
It has been argued that dyslexics suffer from temporal sensory processing deficits which affect their ability to discriminate speech in quiet environments. The impact of auditory deficits on non-language aspects of perception, however, is poorly understood. In almost every natural-listening environment, one must constantly construct scenes of the auditory world by grouping and analyzing sounds generated by multiple sources. We investigated whether dyslexics have difficulties grouping sounds. The results demonstrate that dyslexics have an impairment in grouping auditory objects that depends both on the sounds' frequency and presentation rate (i.e. the spectrotemporal context of the sound). We conclude that dyslexics have difficulty constructing scenes of the auditory world, and that these deficits can contribute to learning impairments.
Assuntos
Percepção Auditiva , Dislexia/fisiopatologia , Adolescente , Adulto , Testes Auditivos , Humanos , Valores de ReferênciaRESUMO
OBJECTIVES: To compare the racial differences in clinical and pathologic features between black and white men who underwent radical prostatectomy (RP) in an equal access health care center and to determine whether race is an independent predictor of biochemical recurrence. METHODS: A retrospective survey of 273 patients (125 black, 148 white) who underwent RP at the West Los Angeles Veterans Affairs Medical Center between 1991 and 1999 was undertaken. Patients were analyzed for racial differences in age at diagnosis, clinical stage, preoperative serum prostate-specific antigen (PSA), and Gleason score of the prostate biopsy specimens. Surgical specimens were studied to determine pathologic stage, Gleason score, incidence of seminal vesicle invasion, positive surgical margins, capsular penetration, and pelvic lymph node involvement. Patients were followed for PSA recurrence (greater than 0.2 ng/mL). Multivariate analysis was used to determine the clinical and pathologic variables that were significant in predicting biochemical recurrence after RP and to determine whether race was an independent predictor of biochemical failure. RESULTS: No significant differences were found between black and white men in the preoperative factors (clinical stage, age at diagnosis, biopsy Gleason score, and serum PSA) or in the pathologic features of the RP specimens (Gleason score, pathologic stage, incidence of positive surgical margins, capsular penetration, seminal vesicle invasion, or lymph node involvement). In addition, no differences were found between black and white men in the PSA recurrence rates after RP using Kaplan-Meier survival curves (P = 0.651). Multivariate analysis revealed that serum PSA (P = 0.010), biopsy Gleason score (P = 0. 003), younger age (P = 0.010), surgical Gleason score (P = 0.005), and lymph node involvement (P = 0.022) were all independent predictors of biochemical recurrence. Race was not a significant predictor of biochemical failure in multivariate analysis (P = 0. 199). CONCLUSIONS: In an equal access medical care facility, no differences were evident between black and white men in the preoperative clinical factors or the pathologic features of the RP specimens. In addition, no differences were observed in the PSA recurrence rates after RP. Serum PSA, biopsy Gleason score, younger age, surgical Gleason score, and lymph node involvement were all independent predictors of biochemical recurrence. Race was not an independent predictor of biochemical recurrence.