RESUMO
Three studies were conducted to investigate whether a chelated Cu can replace CuSO4 as a growth promoter in pigs. In Exp. 1, a total of 240 piglets (Large White×Landrace, 7.36±0.10 kg) were randomly allocated to 1 of 3 treatments with 8 replicates and 10 piglets per pen. Treatments included a NRC control (CuSO4, 6 mg/kg), two Cu supplementations from either CuSO4 or Cu(HMTBa)2 at 170 mg/kg. Pigs fed Cu(HMTBa)2 were 6.0% heavier than pigs fed either the NRC control or 170 mg/kg CuSO4 (p = 0.03) at the end of the experiment. During the 42 days of experimental period, pigs fed Cu(HMTBa)2 gained 9.0% more (p = 0.01), tended to eat more feed (p = 0.09), and had better feed efficiency (p = 0.06) than those fed CuSO4. Compared with the 6 mg/kg CuSO4 NRC control, liver Cu was increased 2.7 times with 170 mg/kg CuSO4 supplementation, and was further increased with Cu(HMTBa)2 (4.5 times, p<0.05). In Exp. 2, a total of 616 crossbred piglets (PIC, 5.01±0.25 kg) were randomly allocated to 1 of 4 treatments with 7 replicates and 22 piglets per pen. Treatments included a NRC control (from CuSO4), and three pharmaceutical levels of Cu (150 mg/kg) supplemented either from CuSO4, tri-basic copper chloride (Cu2[OH]3Cl), or Cu(HMTBa)2. Pigs fed CuSO4 or Cu(HMTBa)2 had better feed efficiency (p = 0.01) and tended to gain more (p = 0.08) compared with those fed the NRC control. Pigs fed Cu2(OH)3Cl were intermediate. Pigs fed Cu(HMTBa)2 had the highest liver Cu, which was significantly higher than those fed (Cu2[OH]3Cl) or the negative control (p = 0.01). In Exp. 3, a total of 1,048 pigs (PIC, 32.36±0.29 kg) were allotted to 6 treatments with 8 replicates per treatment and 20 to 22 pigs per pen. The treatments included a NRC control with 4 mg/kg Cu from CuSO4, a positive control with 160 mg/kg Cu from CuSO4, and incremental levels of Cu(HMTBa)2 at 20, 40, 80, and 160 mg/kg. During the overall experimental period of 100 days, no benefit from 160 mg/kg CuSO4 was observed. Pigs fed Cu(HMTBa)2 had increased ADG (linear and quadratic, p≤0.05) and feed efficiency (linear and quadratic, p≤0.05) up to 80 mg/kg and no further improvement was observed at 160 mg/kg for the whole experimental period. Pigs fed 80 mg/kg Cu(HMTBa)2 weighed 1.8 kg more (p = 0.07) and were 2.3 kg heavier in carcass (p<0.01) compared with pigs fed 160 mg/kg CuSO4. In addition, loin depth was increased with increased Cu(HMTBa)2 supplementation with pigs fed 80 mg/kg Cu(HMTBa)2 had the greatest loin depth (p<0.05). In summary, Cu(HMTBa)2 can be used to replace high CuSO4 as a growth promoter in nursery and grower-finisher pigs.
RESUMO
Radiochemical analysis of (237)Np is important in a number of fields, such as nuclear forensics, environmental analysis and measurements throughout the nuclear fuel cycle. However analysis is complicated by the lack of a stable isotope of neptunium. Although various tracers have been used, including (235)Np, (239)Np and even (236)Pu, none are entirely satisfactory. However, (236g)Np would be a better candidate for a neptunium yield tracer, as its long half-life means that it is useable as both a radiometric and mass spectrometric measurements. This radionuclide is notoriously difficult to prepare, and limited in scope. In this paper, we examine the options for the production of (236g)Np, based on work carried out at NPL since 2011. However, this work was primarily aimed at the production of (236)Pu, and not (236g)Np and therefore the rate of production are based on the levels of (236)Pu generated in the irradiation of (i) (238)U with protons, (ii) (235)U with deuterons, (iii) (236)U with protons and (iv) (236)U with deuterons. The derivation of a well-defined cross section is complicated by the relevant paucity of information on the variation of the (236m)Np:(236g)Np production ratio with incident particle energy. Furthermore, information on the purity of (236g)Np so produced is similarly sparse. Accordingly, the existing data is assessed and a plan for future work is presented.
Assuntos
Espectrometria de Massas/métodos , Netúnio/química , Radiometria/métodos , Urânio/química , Traçadores RadioativosRESUMO
The aim of this study was to investigate the effects of two common food proteins on human enamel erosion in vitro. Erosion was measured by non-contact profilometry in citric, malic and lactic acids at pH 2.8, 3.2 and 3.8 and five commercially available soft drinks, in the presence of a salivary pellicle. Whole milk casein or hen egg ovalbumin was added to the acid solutions and drinks at 0.2% w/v, and the effect on erosion was determined by comparison with the corresponding solution without protein. Casein significantly reduced erosion in all but two solutions. The effects of the individual subfractions of casein in citric acid at pH 3.2 were similar to that of whole casein. Ovalbumin reduced erosion in some solutions, but the magnitude of the reduction was less than that with casein. A greater proportional reduction in erosion was seen in citric acid than in malic or lactic acids. We postulate that the mechanism involves adsorption of proteins to the pellicle or the enamel surface, forming a protein film with enhanced erosion-inhibiting properties. The citrate ion may play an active stabilising role, since erosion reduction was less in the other acids. In conclusion, casein and, to a lesser extent, ovalbumin show promise as potential anti-erosive additives to drinks.
Assuntos
Ácidos/efeitos adversos , Caseínas/administração & dosagem , Esmalte Dentário/efeitos dos fármacos , Ovalbumina/administração & dosagem , Polímeros/administração & dosagem , Erosão Dentária/prevenção & controle , Administração Tópica , Animais , Bebidas/efeitos adversos , Solubilidade do Esmalte Dentário , Película Dentária , Suplementos Nutricionais , Humanos , Concentração de Íons de Hidrogênio , Erosão Dentária/induzido quimicamenteRESUMO
We report a case of isolated rupture of the lateral collateral ligament (LCL) of the knee while attempting to place the left foot behind the head during yoga practice. The 34-year-old man had discomfort of the lateral aspect of the knee particularly with varus strain. A magnetic resonance image revealed rupture of the LCL at the insertion onto the fibula. The patient had grade-II laxity of the LCL and was treated non-operatively. At the 12-month follow-up, grade-I laxity of the LCL remained clinically evident, but function was not impaired.
Assuntos
Ligamentos Colaterais/lesões , Traumatismos do Joelho/diagnóstico , Traumatismos do Joelho/etiologia , Yoga , Adulto , Humanos , Traumatismos do Joelho/terapia , Masculino , Ruptura/diagnóstico , Ruptura/etiologia , Ruptura/terapiaRESUMO
OBJECTIVES: The consumption of acidic soft drinks continues to rise as do concerns regarding effects of frequent intake. The aim of the study was to determine the effect of acidic soft drinks containing food approved polymers, on dental enamel. METHODS: The study design was a single blind, randomised, five-treatment crossover clinical trial involving 15 healthy dentate subjects. Subjects wore an upper removable acrylic appliance retaining two enamel specimens and consumed 250ml of beverage four times/day for 10 days. The following beverages were tested: (1) unmodified acidic soft drink, (2) experimental acidic soft drink with 0.02% polyphosphate, (3) experimental acidic soft drink with 0.02% polyphosphate and 0.01% calcium, (4) experimental acidic soft drink with 0.02% polyphosphate and 0.03% xanthan gum, and (5) mineral water. Tissue loss was measured at days 5 and 10 of each study leg using a profilometer. RESULTS: The order of erosion from most to least at day 10 was unmodified acidic soft drink>experimental acidic soft drink with polyphosphate>experimental acidic soft drink with polyphosphate+gum>experimental acidic soft drink with polyphosphate+calcium>mineral water. At day 10 the unmodified acidic soft drink was significantly (p=0.001) more erosive than all other drinks. CONCLUSIONS: Unmodified acidic soft drink with the addition of polyphosphate alone or combined with calcium or xanthan gum are all effective at reducing erosion of enamel compared with the unmodified soft acidic drink.
Assuntos
Bebidas Gaseificadas/efeitos adversos , Aditivos Alimentares/uso terapêutico , Polifosfatos/uso terapêutico , Substâncias Protetoras/uso terapêutico , Erosão Dentária/prevenção & controle , Ácidos , Adolescente , Adulto , Cálcio/uso terapêutico , Estudos Cross-Over , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/patologia , Feminino , Humanos , Masculino , Águas Minerais , Polissacarídeos Bacterianos/uso terapêutico , Método Simples-Cego , Erosão Dentária/patologiaRESUMO
The nutrient status of forest soils in the Mexico City Air Basin was evaluated by observing plant growth responses to fertilization with N, P or both nutrients combined. P deficiency was the most frequent condition for soil from two high pollution sites and N deficiency was greatest at a low N deposition site. Concentrations of Pb and Ni, and to a lesser extent Zn and Co, were higher at the high pollution sites. However, positive plant growth responses to P and sometimes to N, and results of wheat root elongation bioassays, suggest that heavy metal concentrations were not directly phytotoxic. Further studies are needed to determine if heavy metal toxicity to mycorrhizal symbionts of eucalyptus (Eucalyptus camaldulensis Dehnh.) from high pollution sites may explain the P deficiency and stunted growth. P deficiency is expected to limit the capacity for biotic N retention in N saturated forested watersheds in the Basin of Mexico dominated by Andisols.
Assuntos
Fertilizantes , Magnoliopsida/crescimento & desenvolvimento , Fenômenos Fisiológicos da Nutrição/fisiologia , Poluentes do Solo/análise , Solo/análise , Cobalto/análise , Cobalto/toxicidade , Monitoramento Ambiental/métodos , Eucalyptus/efeitos dos fármacos , Eucalyptus/crescimento & desenvolvimento , Chumbo/análise , Chumbo/toxicidade , Lactuca/crescimento & desenvolvimento , Magnoliopsida/efeitos dos fármacos , México , Níquel/análise , Níquel/toxicidade , Nitrogênio/fisiologia , Fósforo/deficiência , Fósforo/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raphanus/crescimento & desenvolvimento , Poluentes do Solo/toxicidade , Zinco/análise , Zinco/toxicidadeRESUMO
Rats were exposed to black tea (2.5% w/v) as their sole drinking liquid for either 1 day or 1 month, while controls were maintained on water. After this treatment period, all animals received a single oral dose IQ (2-amino-3-methylimidazo-[4,5-f]quinoline), and urine was collected for 48 h. Mutagenic activity of the urine was determined in the Ames test in the presence and absence of an activation system. The excretion of direct-acting mutagens was markedly reduced following tea intake, and was more pronounced after the 1-day treatment. Similarly, both tea treatments suppressed the excretion of indirect-acting mutagens. Furthermore, both tea treatments induced hepatic CYP1A2 activity and expression, but cytosolic glutathione S-transferase activity was only modestly induced in the group of animals receiving tea for 1 day, and only when DCNB (1,2-dichloro-4-nitrobenzene) was used as substrate; glucuronosyl activity was elevated modestly only in the animals receiving the tea for a month. It is concluded that even short-term exposure to black tea is capable of influencing the metabolic fate of IQ, and this is most likely related to the upregulation of CYP1A2.
Assuntos
Carcinógenos/farmacocinética , Citocromo P-450 CYP1A2/biossíntese , Mutagênicos/farmacocinética , Quinolinas/farmacocinética , Chá , Animais , Citocromo P-450 CYP1A2/genética , Citosol/enzimologia , Glutationa Transferase/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Oxigenases de Função Mista/metabolismo , Testes de Mutagenicidade , Nitrobenzenos/metabolismo , Ratos , Ratos Wistar , Regulação para Cima/fisiologia , Aumento de Peso/efeitos dos fármacosRESUMO
Stable isotopes were used to evaluate water sources for co-occurring Jeffrey pine (Pinus jeffreyi Grev & Balf.) and greenleaf manzanita (Arctostaphylos patula Greene) in the southern Sierra Nevada, California, where soils averaged only 75 cm thick but were underlain by up to 5 m of weathered granitic bedrock. Soils and underlying weathered bedrock were sampled three times during both the 1997 and 1998 growing seasons, in 25 cm increments, from 0 to 400 cm or until hard bedrock was reached, and plant stem tissue was sampled simultaneously. Extracted water from the soil/bedrock substrate and plant tissue was analyzed for delta(18)O and/or deltaD, and depth of water source was determined by inference in conjunction with moisture status of the substrate. Water source utilization over the growing seasons for both plants generally followed a pattern similar to that observed for water depletion. Predominant water use was initially from the surface soils. Progressively deeper water sources, including weathered bedrock to a depth of several meters, were exploited as the season progressed and the overlying substrate was depleted of moisture. Early in the growing season, stable isotope values were slightly lower for pine than for manzanita (e.g., average deltaD in June 1997 was -81 per thousand for pine and -77 per thousand for manzanita), and suggest that the functional rooting depth for pine may have been slightly greater than for manzanita. In September 1997, manzanita deltaD values averaged -57 per thousand while pine values averaged -85 per thousand, indicating that manzanita opportunistically utilized summer precipitation while pine used more dependable bedrock water. In 1998, soils remained moist through July due to a late snowfall. Unlike the previous year, pine and manzanita deltaD values were not significantly different in mid- and late-growing season, and both plants exploited bedrock-derived water as soil water was depleted. Water held within bedrock was essential for meeting plant transpirational requirements over the summer drought.
Assuntos
Arctostaphylos/metabolismo , Sedimentos Geológicos , Pinus/metabolismo , Solo/análise , Água/metabolismo , Adaptação Fisiológica , California , Transpiração Vegetal , Chuva , Estações do Ano , Fatores de TempoRESUMO
OBJECTIVE: To assess the influence of different breathing patterns on autonomic cardiovascular modulation during acute exposure to altitude-induced hypoxia. DESIGN: We measured relative changes in minute ventilation (VE), oxygen saturation (%SaO2), spectral analysis of RR interval and blood pressure, and response to stimulation of carotid baroreceptors (neck suction) at baseline and after acute (1 h) hypobaric hypoxia (equivalent to 5,000 m, in a hypobaric chamber). METHODS: We studied 19 human subjects: nine controls and 10 Western yoga trainees of similar age, while breathing spontaneously, at 15 breaths/min (controlled breathing) and during 'complete yogic breathing' (slow diaphragmatic + thoracic breathing, approximately 5 breaths/min) in yoga trainees, or simple slow breathing in controls. RESULTS: At baseline %SaO2, VE and autonomic pattern were similar in both groups; simulated altitude increased VE in controls but not in yoga trainees; %SaO2 decreased in all subjects (P< 0.0001), but more in controls than in yoga trainees (17 versus 12%, 14 versus 9%, 14 versus 8%, all P< 0.05 or better, during spontaneous breathing, controlled breathing and yogic or slow breathing, respectively). Simulated altitude decreased RR interval (from 879 +/- 45 to 770 +/- 39, P < 0.01) and increased indices deducted from spectral analysis of heart rate variability (low frequency/high frequency (LF/HF) ratio from 1.6 +/- 0.5 to 3.2 +/- 1.1, P < 0.05) and systolic blood pressure (low-frequency fluctuations from 2.30 +/- 0.31 to 3.07 +/- 0.24 In-mmHg2, P< 0.05) in controls, indicating sympathetic activation; these changes were blunted in yoga trainees, and in both groups during slow or yogic breathing. No effect of altitude was seen on stimulation of carotid baroreceptors in both groups. CONCLUSIONS: Well-performed slow yogic breathing maintains better blood oxygenation without increasing VE (i.e. seems to be a more efficient breathing) and reduces sympathetic activation during altitude-induced hypoxia.
Assuntos
Altitude , Sistema Nervoso Autônomo/fisiopatologia , Sistema Cardiovascular/inervação , Hipóxia/fisiopatologia , Respiração , Adulto , Pressão Sanguínea/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pescoço , Oxigênio/sangue , Pressorreceptores/fisiologia , Sucção , YogaRESUMO
This study was designed to estimate and compare measures of cochlear travelling wave delay and travelling wave velocity in normally-hearing adults. Travelling wave delay and velocity measures were estimated in 23 normally-hearing adults using three different test techniques: i) derived auditory brainstem responses (ABR); ii) derived frequency-following responses (FFR); and iii) tone-burst-evoked otoacoustic emissions (TBEOAE). Estimates from ABR and TBEOAE were comparable to each other in terms of both averaged group values and associated standard deviations. Furthermore, mean cochlear travelling wave velocity estimated from ABR and TBEOAE were comparable to published estimates. Average cochlear delays obtained using the derived FFR were significantly shorter than those obtained from the other two techniques, possibly due to the effect of cochlear microphonic contamination. Among the dependent variables investigated, measures of delay are to be preferred over velocity since the latter are based on uncertain values of cochlear distance.
Assuntos
Cóclea/fisiologia , Potenciais Evocados Auditivos/fisiologia , Audição/fisiologia , Estimulação Acústica/métodos , Adolescente , Adulto , Artefatos , Audiometria de Tons Puros , Percepção Auditiva/fisiologia , Potenciais Microfônicos da Cóclea/fisiologia , Eletrofisiologia , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Feminino , Humanos , Masculino , Análise Multivariada , Tempo de Reação , Fatores de TempoRESUMO
We have examined the morphological relationship of neuropeptide Y (NPY) and GABAergic neurons in the lamprey spinal cord, and the physiological effects of NPY and GABA(B) receptor agonists on afferent synaptic transmission. NPY-containing fibres and cell bodies were identified in the dorsal root entry zone. NPY immunoreactive (-ir) fibres made close appositions with primary afferent axons. Co-localization of NPY and GABA-ir was found in the dorsal horn and dorsal column. Fifty-two per cent of NPY-ir profiles showed immunoreactivity to GABA at the ultrastructural level. Electron microscopic analysis showed that NPY-immunoreactivity was present throughout the axoplasm, including over dense core vesicles, whereas GABA-immunoreactivity was mainly found over small synaptic vesicles. Synthetic lamprey NPY, and the related peptide, peptide YY, reduced the amplitude of monosynaptic afferent EPSPs in spinobulbar neurons. NPY had no significant effect on the postsynaptic input resistance or membrane potential, the electrical component of the synaptic potential, or the response to glutamate, but it could reduce the duration of presynaptic action potentials, suggesting that it was acting presynaptically. NPY also reduced the excitability of the spinobulbar neurons, suggesting at least one postsynaptic effect. Because NPY and GABA colocalize, we compared the effects of NPY and the GABA(B) agonist baclofen. Both presynaptically reduced EPSP amplitudes, baclofen having a larger effect and a faster onset and recovery than NPY. The GABA(B) antagonist phaclofen reduced the effect of baclofen, but not that of NPY. We conclude that NPY and GABA are colocalized in terminals in the dorsal spinal cord of the lamprey, and that they have complementary actions in modulating sensory inputs.
Assuntos
Neurônios Aferentes/fisiologia , Neuropeptídeo Y/fisiologia , Transmissão Sináptica/fisiologia , Ácido gama-Aminobutírico/fisiologia , Animais , Baclofeno/farmacologia , Feminino , Agonistas dos Receptores de GABA-B , Gânglios Espinais/química , Gânglios Espinais/citologia , Glutamina/metabolismo , Imuno-Histoquímica , Líquido Intracelular/efeitos dos fármacos , Líquido Intracelular/fisiologia , Lampreias , Masculino , Neurônios Aferentes/citologia , Neurônios Aferentes/efeitos dos fármacos , Neuropeptídeo Y/análise , Terminações Pré-Sinápticas/química , Terminações Pré-Sinápticas/ultraestrutura , Receptores de Neuropeptídeo Y/agonistas , Medula Espinal/química , Medula Espinal/citologia , Medula Espinal/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Ácido gama-Aminobutírico/análiseRESUMO
We describe a new dip- and read dipstick that detects urine albumin at concentrations of 10 mg/l and above and urine creatinine at concentrations of 300 mg/l and above. The albumin assay is based on a high-affinity, dye-binding technique while the creatinine assay is based on the peroxidase-like activity of copper creatinine complexes. With these two-test dipsticks, urines from normal adults supplemented with albumin and creatinine were correctly identified to within +/- 15% of the expected value for both analytes; the between-day coefficients of variation ranged from 7.1% to 16.1%. We tested 275 patients' unmodified urines by the Bayer and Boehringer Mannheim Micral-Test albumin dipsticks and for albumin with the Beckman Array on the same specimens. We also analyzed 42 selected urines from the group of 275 for albumin by another quantitative immunochemical method and by electrophoresis plus a total protein method to estimate the albumin concentration. The quantitative immunochemical methods appear to underestimate the urine albumin concentrations; in these 42 urines measured as negative, i.e., < ca. 16-20 mg/l, by one of the quantitative method but positive by the Bayer dipstick, 33 of these were positive by the electrophoresis/total protein assay combination. The Bayer albumin dipstick correctly identified urines as having < 16 mg/l or > or = 16 mg/l at an 80% rate. At a cutoff of 20 mg/l, the rate increased to 87%. We also determined the urinary albumin/creatinine ratios on the 275 patients using the Bayer two-pad dipstick and found agreement 84% of the time with the same ratio obtained from a quantitative immunochemical method for albumin and a rate-Jaffe method for creatinine; an albumin/creatinine ratio (mg/g) of 30 was used as the discrimination point. Albumin stability studies performed on the Beckman Array patients with six fresh urines showed small but consistent decreases at -20 degrees C but not at 4 degrees C after one month of storage. The albumin in contrived urines, as estimated by electrophoreses/total protein and by the dipsticks did not change at these storage conditions. Boric acid at 1 g/l as a urine preservative had no effect on the measurement of albumin by any of the methods described here nor of the assay of creatinine. Other urinary proteins present at abnormal excretion rates did not interfere with the Bayer albumin dipstick. Abnormal concentrations of bilirubin, citrate, creatine, ascorbic acid, albumin, hemoglobin and myoglobin in urine did not interfere with the creatinine dipstick measurements. The first four of the above did not affect the Bayer dipstick results for albumin.
Assuntos
Albuminúria/diagnóstico , Fitas Reagentes , Urinálise/métodos , Adulto , Creatinina/urina , Eletroforese em Gel de Poliacrilamida , Estudos de Avaliação como Assunto , Humanos , Testes de Precipitina , Proteinúria , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Ten metals were assayed in 21 Indian ponds which comprised three groups: (i) eutrophic alkaline ponds containing <2.5 mM potassium and thick growths of Microcystis aeruginosa or Microcystis flos-aquae during most of the year, (ii) equally eutrophic alkaline ponds containing >2.8 mM potassium and no detectable Microcystis growth, and (iii) oligo- or mesotrophic ponds with various potassium and hydrogen ion concentrations and no persistent Microcystis blooms. The effects of potassium on Microcystis growth were examined in filter-sterilized pond water and in defined culture media. A 50% reduction in the 10-day yield of cultured M. aeruginosa was observed in DP medium and pond water supplemented with 1 and 3 mM KCl, respectively. In contrast, the addition of 2 to 30 mM NaCl did not suppress the growth of M. aeruginosa in either DP medium or pond water. Both 5 mM KCl and 20 mM KHCO(inf3) in J medium strongly inhibited the growth of M. flos-aquae C3-9, whereas 5 to 30 mM NaCl had no effect and 20 mM NaHCO(inf3) was stimulatory. For pond water cultured with a mixture of M. aeruginosa and the duckweed Wolffia arrhiza, M. aeruginosa dominated in unsupplemented water and W. arrhiza dominated in water supplemented with 4.8 mM KCl. Implications for the ecology and control of Microcystis blooms are discussed.
RESUMO
Twenty neonates in a special care baby unit (SCBU) were tested using automated procedures for obtaining auditory brainstem responses (ABR) and transient evoked otoacoustic emissions (TEOAE). All 40 ears passed the initial ABR screen, while the pass rate for the TEOAE screen was only 52.5%. Ears with no external or middle ear abnormalities (group A) had a significantly higher TEOAE pass rate (94.7%) than those with at least one abnormality (group B) as detected by otoscopic examination and tympanometry (14.3%). Other variables, such as age at test, gestational age at birth and birth weight, did not differ significantly between groups A and B. We conclude that external/middle ear abnormalities in this group of neonates had no effect on the ABR screening results, but had a significant effect on the TEOAE screening results.
Assuntos
Estimulação Acústica , Cóclea/fisiologia , Otopatias/diagnóstico , Otopatias/fisiopatologia , Orelha Média/fisiopatologia , Potenciais Evocados Auditivos do Tronco Encefálico , Recém-Nascido , Testes de Impedância Acústica , Eletroencefalografia , Lateralidade Funcional , Humanos , Triagem NeonatalRESUMO
Testosterone has been shown to stimulate bone healing. However, large doses of testosterone have been associated with liver damage and prostate enlargement. Sustained release of testosterone by a device placed next to a bone fracture could deliver effective amounts of the steroid necessary for bone healing without the adverse side effects associated with oral delivery or intramuscular injection. The release of 1 mg of testosterone into 1 ml of 50% ethanol from one-hour calcined hydroxyapatite (HA) ceramics (n = 6) and twelve-hour calcined HA ceramics (n = 6) was measured over four days. The twelve-hour calcined HA ceramics exhibited a consistently slower testosterone release. A 200mg HA/0.1% PLA/gentamicin (1mg) ceramic cylinder containing 0, 0.5, 1.0, or 1.5 mg testosterone was placed adjacent to a 4 x 1 x 1 mm femoral defect created in four equal groups of twenty-seven castrated male Sprague Dawley rats. After four weeks, none of the ceramics contained any residual testosterone. Histological examination showed that the traumatized bone of the animals implanted with testosterone-containing ceramics healed faster for the first four weeks than the controls. This data suggests that the twelve-hour calcined HA should be used to extend the release of testosterone to enhance healing of traumatized bone.
Assuntos
Implantes de Medicamento , Testosterona/administração & dosagem , Animais , Cerâmica , Durapatita , Consolidação da Fratura/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Difração de Raios XRESUMO
Despite the dearth of rigorous empirical investigation, reflection and reflective practice have become buzz words in nursing and midwifery education. Reflection and critical incident analysis may be tools which can facilitate the integration of theory and practice. It is proposed that in the absence of explicit and thorough preparation of lecturers and students, together with very careful curriculum planning, these activities may be counter-productive or even harmful. In the absence of structure, reflection and associated critical incident analysis may lead to student disaffection or, worse, the potential for actual psychological disturbance. Empirical studies on the use of identified models of reflection and critical incident analysis are urgently needed to assist nursing and midwifery lecturers and students to achieve predictable learning outcomes for this potentially valuable activity.
Assuntos
Educação em Enfermagem/métodos , Tocologia/educação , Aprendizagem Baseada em Problemas , Ensino/métodos , Pensamento , Atitude do Pessoal de Saúde , Revelação , Pesquisa Empírica , Ética em Enfermagem , Relações Interprofissionais , Julgamento , Cuidados de Enfermagem/normas , Resolução de Problemas , Apoio Social , Estudantes de Enfermagem/psicologia , Revelação da Verdade , Reino Unido , Denúncia de IrregularidadesRESUMO
Little research exists that explores subcortical function in people who stutter. One study suggested that auditory middle latency response Wave Pb was prolonged in subjects who stutter as compared to controls. Other studies have suggested that Pb was generated within the thalamic portion of the reticular system. MLRs were recorded from 10 males who stutter and 10 controls using a variety of filter passbands in response to clicks presented binaurally at various rates. The latency of Pb was found to be significantly shorter in the group of subjects who stutter.
Assuntos
Estimulação Acústica , Gagueira , Adulto , Humanos , Masculino , Formação Reticular/fisiologia , Índice de Gravidade de Doença , Tálamo/fisiologiaRESUMO
This paper begins with a summary of the biological research on homosexuality that occurred in the late 1980s and early 1990s. It then summarizes the treatment of this research chiefly by the print media. It then adumbrates the presuppositions about sexuality and gender upon which the reports were based. It is argued that the presuppositions, which are asserted without being examined, date back to the nineteenth century. They ignore the historical, sociocultural, and humanistic research of the last two decades that collectively comprise the field of gay, lesbian, and bisexual studies. The discussion of the issue of choice follows and it recognizes the various constraints on choice without eliminating it as an element of sexual expression. Finally, the paper sets forth a general conception of homosexuality that includes its psychological and socio-cultural dimensions along with the biological.
Assuntos
Identidade de Gênero , Homossexualidade/psicologia , Sexo , Comportamento Sexual/fisiologia , Características Culturais , Feminino , Hormônios Esteroides Gonadais/fisiologia , Humanos , Hipotálamo/fisiologia , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Diferenciação Sexual/fisiologia , Meio SocialRESUMO
In view of the current audiological need to obtain rapidly recorded and objective threshold information, particularly for frequencies below 1 kHz, we have developed an evoked potential technique based on the frequency following response. The technique involves the acquisition of a single captured epoch of EEG containing phase-locked responses to 1000 cycles of a continuous pure-tone stimulus. The captured epoch is partitioned into segments representing the responses to single cycles of the stimulus. The segments are then averaged to produce the period evoked potential. The process takes less than five seconds.