The effects of chronic administration of hydrocortisone on cognitive function in normal male volunteers

Rationale: Corticosteroids are elevated in certain neuropsychiatric disorders and this may contribute to the neuropsychological impairments reported in these disorders. Objective: To examine the effects of hydrocortisone on learning, memory and executive function. Methods: Hydrocortisone 20 mg was administered twice daily for 10 days to normal male volunteers in a randomized, placebo control, crossover, within-subject design. Learning, memory and executive function were measured using selected subtests from the Cambridge Neuropsychological Test Automated Battery. Results: Hydrocortisone caused impairments of visuo-spatial memory. These included increased within search errors and impaired use of strategies on the spatial working memory subtest. In addition, administration of hydrocortisone was associated with more errors in the paired associate learning subtest, although no effect was found on the Tower of London. Hydrocortisone speeded response latencies in certain tests (pattern and spatial recognition memory). Conclusion: These results indicate that chronic administration of hydrocortisone leads to deficits in certain tests of cognitive function sensitive to frontal lobe dysfunction and may contribute to the cognitive impairment reported in certain neuropsychiatric disorders. Received: 27 July 1998 / Final version: 9 February 1999     

Preparing Older People to Cope after a Fall

Clinical experience and previous research show that older people at risk of falling can become anxious at the thought of being on the floor, therefore physiotherapists and occupational therapists may be reluctant to teach them how to get up.Old people's reactions to two different methods of teaching them this skill are compared (three groups, mean age 84 years). The conventional method requires people to be helped down to the floor and then to learn how to get on to their knees prior to getting up with the help of furniture. An alternative method, based on backward-chaining principles, does not require that people start from the floor and reduces the likelihood of them experiencing failure. The activity is broken down into small steps — the last step in the chain being taught first.It is concluded that:

1 The backward-chaining method of teaching elderly people how to get up from the floor is much less stressful to older people and to staff than the conventional method.

2 Older people are slightly more likely to learn successfully how to get up from the floor by the backward-chaining method which, even if they are not successful, provides them with functionally relevant exercise.

3 Older people who cannot learn to get up from the floor should be helped to develop alternative strategies for summoning help and for preventing the consequences of the long lie.

Dose-incidence curves for tumour control and normal tissue injury, in relation to the response of clonogenic cells

A probit analysis has been made of data from the literature on local control of tumours and injury to normal tissue as a function of dose of radiation. Fifteen series were analysed for local tumour control in man and ten series for complications. The analysis yielded values for the D50 dose (50% incidence of effect) and the probit width (K), a measure of the steepness of the dose-incidence curve. The same analyses were made of data for rodents. Broadly, K was proportional to D50 in the ratio 1:7, with no major differences between tumours and reported complications. D50 was plotted as a function of dose per fraction for four normal tissues and two tumours in rodents. D50 decreased more rapidly with increasing dose per fraction for the normal tissues than for tumours. The probit width, K, varied inversely with increasing dose per fraction for normal tissues and this contrasted with the tumour response. Thus with increasing dose per fraction, the threshold for effect decreased and the steepness of the ensuing dose-incidence curve increased, relatively more rapidly for normal tissue than for tumour. These curves of gross response have been analysed also by the double negative log method of Gilbert [23], in an attempt to estimate the number and survival characteristics of "tissue-rescuing cells". These were calculated to be less than 1 in 10(4) of the numbers of clonogenic cells measured by excision assays. The D0 values of the derived survival curves for these tissue-rescuing cells were higher than those measured by excision assays.     

Neurotransmitter markers in the cerebrospinal fluid of normal subjects effects of aging and other confounding factors

Summary We have investigated neurotransmitter-related markers of the cerebrospinal fluid (CSF) in a carefully screened series of normally aging subjects in standardized conditions in order to find out the influence of age and other confounding factors on CSF measures. The levels of 3-methoxy-4-hydroxyglycol (MHPG) and the activity of acetylcholinesterase (AChE) also increased with age, while homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5 HIAA) and immunoreactivities of somatostatin (SLI), beta-endorphin (BLI) and adrenocorticotropic hormone (ACTH) were unrelated to age. The gender of subjects had no significant effect on the levels of neurotransmitter markers, while seasonal changes, as well as height and weight of the subjects seemed to cause some variations in the levels of HVA, dopamine--hydroxylase (DBH) and ACTH. The study underscores the importance of standardized conditions and matched patient groups in the CSF studies.     

Biological bases for high RBE values for late effects of neutron irradiation

The late effects of fractionated irradiation with neutrons have been relatively more severe than after x-irradiation. Reasons for the RBEn/x being higher for late than for acute effects may include: (1) Late effects are reduced more by fractionation of X ray doses than are acute effects, whereas, with neutrons, the fractionation response is the same in rapidly-and slowly-responding tissues; (2) Late-responding tissues are less "sensitized" (and are, therefore, relatively protected) by redistribution throughout the division cycle during a fractionated regimen than are acutely-responding tissues: since neutron responses are less affected by cell-cycle distribution than are X ray responses, the relative protection of slowly-responding tissues is less; (3) The target cells for late, but not acute injury, may repair potentially lethal damage after X ray, but not after neutron exposure. Thus, the dissociation of RBE values for acute and late injury reflects mainly the dissociation between acute and late responses to conventional fractionated X ray regimens and, from the point of view of complications of radiotherapy, we should not condemn neutrons but praise X rays. Since fractionation of neutron doses into increments equivalent to those used in X ray therapy does not provide a preferential sparing of slowly-responding tissues, it is reasonable to shorten the overall duration of neutron treatment to deliver the total dose tolerated by the relevant "late-effects" tissue(s) in the shortest time consistent with acceptable acute responses.     

Differentiation of normal pressure hydrocephalus and cerebral atrophy by computed tomography and spinal infusion test

Summary The diagnostic value of computed tomography (CT) and spinal infusion test (SIT) was investigated in 27 patients with normal pressure hydrocephalus (NPH) and 35 patients with cerebral atrophy. The most consistent CT finding of NPH was dilatation of the temporal horns, that of cerebral atrophy widening of the convexity sulci. However, 43% of patients with cerebral atrophy demonstrated no cortical atrophy. The SIT showed an excellent relation with isotope cisternography and continuous intracranial pressure recording. NPH and cerebral atrophy were correctly differentiated in 71% by CT and SIT. A normal SIT and a CT scan without the typical features of NPH exclude impairment of cerebrospinal fluid absorption. An abnormal SIT and a CT scan showing ventricular enlargement without dilatation of convexity sulci, require isotope cisternography and possibly intracranial pressure recording to determine the degree of the absorption deficit.

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Zusammenfassung Der diagnostische Wert von Computertomographie (CT) und Spinalen Infusions-Test (SIT) wurde bei 27 Patienten mit Normal Pressure Hydrocephalus (NPH) und 35 Patienten mit zerebraler Atrophie untersucht. Der häufigste CT-Befund des NPH war Erweiterung der Temporalhörner und bei zerebraler Atrophie eine Erweiterung der Konvexitätssulci. Aber 43% der Patienten mit zerebraler Atrophie zeigte keine Rindenatrophie. Der SIT zeigte eine sehr gute Korrelation mit Isotopenzisternographie und kontinuierlicher intrakraniellen Druckmessung. NPH und zerebrale Atrophie wurden korrekt differenziert in 71% mittels CT und SIT. Ein normaler SIT und ein CT-Scan ohne die typischen Merkmale von NPH schließen Liquorrückresorptionsstörungen aus. Ein abnormer SIT und ein CT-Scan, der einen Hydrozephalus ohne Erweiterung der Konvexitätssulci zeigt, erfordern eine Isotopenzisternographie und eventuell intrakranielle Druckmessung zur Ermittlung des Grades der Liquorrückresorptionsstörung.

     

Bright light treatment for night-time insomnia and daytime sleepiness in elderly people: comparison with a short-acting hypnotic

Night-time bright light (BL) treatment and triazolam (0.125 mg/day) were given to three healthy elderly people in a cross-over design. They kept a daytime sleepiness test and a sleep log, and their wrist-activity was monitored simultaneously. Subjectively, BL increased daytime sleepiness and naps, and decreased night-time sleep. Triazolam decreased daytime sleepiness and naps, and increased night-time sleep. Actigraphic night-time sleep and naps on the first day were similar to these results. However, on the fourth day night-time insomnia induced by BL had recovered, and naps were shorter than the baseline. Triazolam increased actigraphic naps as the days passed.     

两种过滤方法对输液中微粒的影响

目的 :比较超滤法和常规三级过滤法对输液中微粒的影响。方法 :用光阻法检查两种不同的过滤方法滤过的输液中微粒数。结果 :常规三级过滤法滤过的 4 7批次的输液平均微粒数为 6 .5 6个 /ml(>10 μm)和 0 .71个 /ml(>2 5 μm) ,超滤法滤过的 6 3批次的输液平均微粒数为 2 .2 9个 /ml(>10 μm)和 0 .2 8个 /ml(>2 5 μm) ,两种方法有显著性差异 (P <0 .0 0 1)。结论 :超滤法明显优于常规三级过滤法。     

Dose-Volume Histograms for bladder and rectum

: A careful examination of the foundation upon which the concept of the Dose-Volume Histogram (DVH) is built, and the implications of this set of parameters on the clinical application and interpretation of the DVH concept has not been conducted since the introduction of DVHs as a tool for the quantitative evaluation of treatment plans. The purpose of the work presented herein is to illustrate problems with current methods of implementing and interpreting DVHs when applied to hollow anatomic structures such as the bladder and rectum.

: A typical treatment plan for external beam irradiation of a patient with prostate cancer was chosen to provide a data set from which DVH curves for both the bladder and rectum were calculated. The two organs share the property of being shells with contents that are of no clinical importance. DVHs for both organs were computed using a solid model and using a shell model. Typical treatment plans for prostate cancer were used to generate DVH curves for both models. The Normal Tissue Complication Probability (NTCP) for these organs is discussed in this context.

: For an eight-field conformal treatment plan of the prostate, a bladder DVH curve generated using the shell model is higher than the corresponding curve generated using the solid model. The shell model also has a higher NTCP. A six-field conformal treatment plan slo results in a higher DVH curve for the shell model. A treatment plan consisting of bilateral 120-degree arcs, results in a higher DVH curve for the shell model, as well as a higher NTCP.

: The DVH concept currently used in evaluation of treatment plans is problematic because current practices of defining exactly what constitutes “bladder” and “rectum.” Commonly used methods of tracing the bladder and rectum imply use of a solid structure model for DVHs. In reality, these organs are shells and the critical structure associated with NTCP is obviously and indisputably the shell, as opposed to its contents. Treatment planning algorithms for DVH computation should thus be modified to utilize the shell model for these organs.     

北京市部分地区老年人消化性溃疡患病率及相关因素调查分析

本文系 1993年 7～ 10月对北京市部分地区 34 4 0名 60岁以上老年人进行的消化性溃疡病 ( PU)的患病率及影响因素的调查。采取入户问卷调查的方式 ,结果表明 :老年人 PU的患病率在 4 .1% ;男性高于女性 ( 5.3% ,2 .9% ) ;低龄老人高于高龄老人 ;山区高于城区和郊区。在与 PU有关的影响因素中 ,抑郁、脑力劳动、吸烟、大量饮酒及高文化程度是老年 PU的危险因素 ,饮食结构及少量饮酒与 PU的患病率在统计学上未见显著差异。提示老年人 PU患病率在不同年龄、性别、地区、文化程度及职业上均有差异 ,同时心理因素对 PU的影响也不容忽视。