A new physical assay method for tobacco mosaic virus using a radioactive virus recovery standard and the first derivative of the ultraviolet absorption spectrum

A new physical assay method for tobacco mosaic virus is described which incorporates two improvements on previous procedures. Losses of up to 75% of virus during extraction are corrected by adding a trace of radioactive virus to leaf samples before homogenization, and determining percentage recovery of radioactivity in final virus preparations. Estimation of virus concentration in partially purified preparations is from the first derivative (dA/d lambda) of the ultraviolet absorption spectrum, using a pronounced signal from the tryptophan fine-structure absorption band at 285-293 nm. This method is highly insensitive to ultraviolet-absorbing contaminants, which cause errors and increase variation between replicates, when estimation of virus concentration is by normal measurement of ultraviolet absorption (A260). The method can be applied to at least some other viruses.     

The early phase of experimental acute renal failure

Summary Experiments were designed to determine whether leakage of substances across the tubular epithelium, which are impermeant in the normal kidney, falsifies the measurement of glomerular filtration rate in acute renal failure. Permeability to those substances most commonly used for filtration rate determination, polyfructosan, inulin and ferrocyanide, was estimated by measuring their recoveries following perfusion through various nephron segments in haeme pigment, ischaemic and nephrotoxic models of actue renal failure. Late proximal recovery of¹⁴C ferrocyanide was only marginally decreased compared to controls, by a maximum of 6%. Distal recovery of polyfructosan,¹⁴C and³H inulin were depressed somewhat more, by a maximum of 11%. Urinary recovery of¹⁴C inulin was reduced by only 15% in kidneys showing severely restricted renal function. It is concluded that tubular leakage is not a feature of significance in the early phase of moderate acute renal failure, that ferrocyanide and inulin are reliable markers for the determination of nephron filtration rate and water reabsorption, and that the reduction in whole kidney inulin or polyfructosan clearance reflects primarily a reduction in glomerular filtration rate.     

Anger Cognitions and Cardiovascular Recovery Following Provocation

The current study describes the creation and validation of the Anger Cognitions Inventory (ACI) to assess the cognitive appraisals associated with resentful and reflective anger. The ACI was created based on a content analysis of self-reports of participants' thoughts and feelings following anger provocation in the laboratory. Exploratory and confirmatory factor analyses on two separate college student samples (N = 267 and N = 276, respectively) revealed five subscales which could validly be grouped into resentful and reflective anger. Convergent and divergent validity data showed that resentful anger correlated positively with anger-out/trait anger and reflective anger correlated positively with anger-in/brooding. A second study showed positive correlations between rumination and delayed cardiovascular recovery following anger provocation. Limitations of both studies include restricted samples which limit generalizability of results and cardiovascular recovery data collected in Study II which does not include assessment of autonomic balance between vagal and sympathetic responsivity.     

Neurochemical correlates of sparing from motor deficits in rats depleted of striatal dopamine as weanlings

The behavioral and neurochemical effects of striatal DA depletions were investigated in rats lesioned as weanlings (Day 27) or as adults (250-300 g). Administration of 6-OHDA into the medial forebrain bundle resulted in comparably large (> or = 95%) depletions of tissue levels of DA in both age groups. As expected, rats depleted of DA as adults exhibited marked deficits in motoric behavior and body weight regulation that persisted for the 8 days of postsurgical observation. In contrast, rats depleted of DA as weanlings were spared from such deficits, and their behavior closely resembled that of age-matched controls. Microdialysis studies revealed dialysate levels of striatal DA that paralleled these age-dependent behavioral differences. At a time when age-related behavioral differences were still quite pronounced (5-6 days postsurgery), basal DA levels were reduced by 80% of control values in rats lesioned as adults whereas basal DA levels in rats lesioned as weanlings were unchanged relative to their controls. Finally, adults depleted of striatal DA as weanlings were no more sensitive to the movement-impairing effects of intrastriatal sulpiride (3.0 or 10.0 micrograms/hemisphere) infusions than were control rats. These data suggest that weanlings compensate for large, but incomplete, denervation of striatal DA with markedly enhanced release and turnover from residual terminals. This developmental plasticity may prevent the occurrence of behavioral deficits soon after the lesion and also the supersensitivity to the challenging effects of DA antagonists as animals grow into adulthood.     

Effects of "Below-Zero" Habituation on the Electrodermal Orienting Response to a Test Stimulus

Two experiments were designed to investigate the effect of below-zero habituation training on skin conductance response (SCR) amplitude to a change in auditory stimulus frequency. In both experiments, subjects were trained with a 1000 Hz tone until zero responding and then received 5, 10, or IS further training trials. In Experiment 1 (N=45), subjects then received 1 presentation of a test stimulus of 1400 Hz, while in Experiment 2 (N=45), the test stimulus was a tone of 670 Hz. On the basis of dual-process theory, it was hypothesized that response amplitude to the test stimulus would be inversely related to amount of below-zero training. However, the results of both experiments indicate that SCR amplitude was positively related to amount of below-zero training. These results suggest that in situations of extended habituation training, an expectancy or subjective probability of stimulus occurrence gradient is important in determining response amplitude to a test stimulus.     

The recovery of α-adrenoceptor function and binding sites after phenoxybenzamine

Summary The recovery of peripheral -adrenoceptor function and binding sites was studied in male New Zealand white rabbits after treatment with the irreversible adrenoceptor antagonist phenoxybenzamine. Phenoxybenzamine (5 mg/kg) was administered intravenously and the animals studied 30 min to 12 days later. Pressor dose response curves to intravenous phenylephrine, noradrenaline and guanabenz were constructed in vivo in conscious animals. The contractile response of abdominal aorta and renal artery to phenylephrine and noradrenaline was examined in vitro and the recovery of specific prazosin and clonidine binding to spleen membranes investigated in radioligand binding studies.The half life (t _1/2) for recovery of maximum pressor response in vivo ranged from 0.9±0.2 days for phenylephrine to 1.4±0.1 days for guanabenz. The t _1/2 for recovery of ED₅₀ was not significantly different to t _1/2 for recovery of maximum pressor response and ranged from 0.8±0.2 days for noradrenaline to 1.3±0.3 days for phenylephrine.Half life for recovery of maximum response and EC₅₀ in the isolated tissues was similar to that obtained in vivo for recovery of pressor responses and ranged from 0.4±0.1 days for the EC₅₀ of noradrenaline in the renal artery to 1.2±0.6 days for maximum response to phenylephrine in the abdominal aorta.The rate of recovery of specific clonidine binding did not differ significantly from the rate of recovery of pressor responses to the ₂-selective agonist guanabenz. t _1/2 for maximum number of specific clonidine binding sites, B _max was 1.6±0.9 days. However t _1/2 for recovery of specific prazosin binding was significantly longer than recovery of responses to phenylephrine and noradrenaline, t _1/2 for B _max was 3.6 ±0.1 day.     

经治艾滋病患者免疫恢复 和免疫无应答相关研究进展

[摘要]　有效的抗反转录病毒治疗（antiretroviral therapy, ART）可以持续抑制HIV-1复制,同时促进HIV-1感染者的免疫恢复。然而不同疾病阶段的艾滋病患者经ART后的预后不同,大部分HIV-1感染者免疫恢复较好,但仍有15%～30%左右的HIV-1感染者无法实现有效的免疫重建,即免疫无应答者（immunological non-responders, INRs）。本文重点介绍了免疫恢复的分类及定义,导致INRs的可能原因以及针对INRs治疗的临床试验进展,以期为INRs的诊断和治疗寻找潜在的方向     

The Application of Creatine Supplementation in Medical Rehabilitation

Numerous health conditions affecting the musculoskeletal, cardiopulmonary, and nervous systems can result in physical dysfunction, impaired performance, muscle weakness, and disuse-induced atrophy. Due to its well-documented anabolic potential, creatine monohydrate has been investigated as a supplemental agent to mitigate the loss of muscle mass and function in a variety of acute and chronic conditions. A review of the literature was conducted to assess the current state of knowledge regarding the effects of creatine supplementation on rehabilitation from immobilization and injury, neurodegenerative diseases, cardiopulmonary disease, and other muscular disorders. Several of the findings are encouraging, showcasing creatine’s potential efficacy as a supplemental agent via preservation of muscle mass, strength, and physical function; however, the results are not consistent. For multiple diseases, only a few creatine studies with small sample sizes have been published, making it difficult to draw definitive conclusions. Rationale for discordant findings is further complicated by differences in disease pathologies, intervention protocols, creatine dosing and duration, and patient population. While creatine supplementation demonstrates promise as a therapeutic aid, more research is needed to fill gaps in knowledge within medical rehabilitation.     

Applying the Stages of Change Model in a Nutrition Education Programme for the Promotion of Fruit and Vegetable Consumption among People with Severe Mental Disorders (DIETMENT)

Despite growing evidence of the benefits of adequate intake of fruit and vegetables (F&V) and the recommendation to consume five servings daily, the adoption of these habits is poor among people with severe mental disorder (SMD). The main aim of the present study is to determine changes in the intake of F&V and motivation to do so among people with SMDs after participating in a food education programme. A community-based randomized controlled trial was conducted in Spain, with the intervention group (IG) participating in a food education programme based on the stages of change model to promote consumption of F&V and the control group (CG) receiving three informative sessions on basic healthy eating. The main outcomes were related to the intake of F&V and stages of change. Data collection was performed at baseline, post intervention, and 12-month follow-up. Seventy-four participants enrolled in the study and sixty completed the 12-month follow-up. An increase in motivation towards the intake of F&V was observed in the IG but not in the CG (McNemar’s test p = 0.016, p = 0.625). No significant difference was observed for the intake of fruit, vegetables, or F&V. Basing food education strategies on the stages of change model shows positive results, increasing the awareness and disposition of people with SMD towards the intake of F&V. More research is needed to identify the most appropriate eating intervention to increase the intake of F&V.     

Giving a voice to patient experiences through the insights of pragmatism

As a philosophical position, pragmatism can be critiqued to distinguish truth only with methods that bring about desired results, predominantly with scientific enquiry. The article hopes to dismiss this oversimplification and propose that within mental health nursing, enquiry enlightened by pragmatism can be anchored to methods helping to tackle genuine human problems. Whilst pragmatists suggest one reality exists, fluctuating experiences and shifting beliefs about the world can inhabit within; hence, pragmatists propose reality has the potential to change. Moreover, pragmatism includes being cognisant of what works to whom reality concerns, making reality context-driven, with a view to understand how actions shape experiences so what is generated has usefulness. Hence, it somewhat follows pragmatism can inform mental health nursing, after all, nursing is a discipline of action, and awareness is needed in how actions produce experiences that patients find helpful. Given the principles of recovery are preferably adopted in mental health care, the paper will explore how pragmatism can help nurses move towards that goal; specifically, with patients voicing their experiences. This is because like pragmatism, recovery subscribes to hope that reality can progress, and through meaningful experiences and beliefs, patients have expertise about personal difficulties alongside how life may flourish, despite mental illness.