[Biopsy of the posterior segment of the eye].
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Biopsy↗
Biomedical subjects
J Haller
Publications and source records attributed to J Haller.
Neuroleptic influences on a lateralized behavioral bias in unoperated rats.
RATIONALE: Abnormalities of the ascending dopaminergic system have been associated with hemineglect, and evidence suggests that neuroleptic treatments normalize the right hemispatial attentional impairment that is sometimes observed in acutely psychotic schizophrenic patients. OBJECTIVE: A research program was initiated to develop an animal model of hemineglect-drug interactions. METHODS: Female rats were tested repeatedly on removing a "nuisance stimulus" - strips of surgical tape applied loosely to the forelimbs. Subjects were assigned to groups dependent upon showing a behavioral orientation preference (BOP) during pre-drug baseline tests. Animals representing left-BOP, right-BOP and no preference continued to be tested during chronic exposure either to a dopamine antagonist (0.05 mg haloperidol/kg) or agonist (1.0 mg d-amphetamine/kg) or vehicle only. RESULTS: Three weeks of haloperidol treatments to rats only with an initial right BOP gradually eliminated the response bias, as revealed by declines in choosing the right forepaw and the latencies between attending to the two forepaws. CONCLUSION: The results recommend right BOP female rats as a simple, non-invasive behavioral animal model for evaluating and comparing neuroleptic medications.
Amphetamine↗
Mild social stress abolishes the effects of isolation on anxiety and chlordiazepoxide reactivity.
RATIONALE: Social isolation is anxiogenic and may change the effects of anxiolytic drugs. These effects are generally attributed to "isolation stress". However, isolation does not affect basal corticosterone levels; thus, it cannot be considered stressful. On the contrary, isolation deprives animals of mild daily stressors that are inherent to social life. Since mild stressors were shown to be anxiolytic in rats, it was postulated that short-term, repeated stressors may abolish the effects of isolation. OBJECTIVES: The aim of the present study was to investigate whether short-term, repeated, mild social stress can abolish the consequences of isolation on anxiety and on the effects of chlordiazepoxide. METHODS: Rats were housed in groups or in individual cages for 5 days (isolates). Half of isolates were daily submitted to the attacks of a resident rat for 30 min per day, on 4 consecutive days (stressed isolates). On day 5, rats were treated either with vehicle or with chlordiazepoxide and submitted to the elevated plus-maze test. Endocrinological consequences of experimental manipulations were assessed in a different set of rats. RESULTS: Plasma ACTH and corticosterone levels were similar in the three groups. Weight gain was higher, while plasma growth hormone was lower in stressed isolates, both effects being consistent with a mild stress. Isolation had a clear anxiogenic effect. This effect was completely abolished by the daily experience of social stress. Chlordiazepoxide had a significant anxiolytic effect in all three groups. Its effects on classical plus-maze variables did not differentiate the three groups. However, chlordiazepoxide decreased risk assessment activity only in isolates. CONCLUSIONS: The lack of appropriate endocrinological changes challenges the concept of "isolation stress". However, isolation was anxiogenic in our study and it also induced subtle changes in the effects of chlordiazepoxide. It appears that mild daily stressors have a protective effect against the effects of isolation.
Adrenocorticotropic Hormone↗
[Nutrition assessment of the elderly based on results of the SENECA Study "Nutrition and the elderly in Europe"].
The SENECA Study "Nutrition and the elderly in Europe" investigates men and women born 1913-1918 in 20 small traditional towns in Europe. At the age of 74-79 years subjective health was satisfactory or good in 95% of 399 men and 93% of 414 women in 6 study towns. In these subjects suboptimal nutritional blood values were virtually nonexistent. Food intake was low in energy and rich in protein and fat. Lowest European recommended dietary allowances were not reached by all subjects. The even higher values recommended as potentially protective factors were not met by a substantial part of subjects with energy intakes below 6.3 MJ/d. Regularity of food intake was high and had increased over 4 years. Living alone did not adversely affect food intake while low economic situation did.
Aged↗
Virtual arthroscopy of the visible human female temporomandibular joint.
PURPOSE: This study was designed to obtain views of the temporomandibular joint (TMJ) by means of computed arthroscopic simulation (virtual arthroscopy) using three-dimensional (3D) processing. MATERIAL AND METHODS: Volume renderings of the TMJ from very thin cryosection slices of the Visible Human Female were taken off the Internet. Analyze(AVW) software (Biomedical Imaging Resource, Mayo Foundation, Rochester, MN) on a Silicon Graphics 02 workstation (Mountain View, CA) was then used to obtain 3D images and allow the navigation "fly-through" of the simulated joint. RESULTS: Good virtual arthroscopic views of the upper and lower joint spaces of both TMJs were obtained by fly-through simulation from the lateral and endaural sides. It was possible to observe the presence of a partial defect in the articular disc and an osteophyte on the condyle. Virtual arthroscopy provided visualization of regions not accessible to real arthroscopy. CONCLUSION: These results indicate that virtual arthroscopy will be a new technique to investigate the TMJ of the patient with TMJ disorders in the near future.
Arthroscopy↗
Social stress of variable intensity: physiological and behavioral consequences.
Stress effects in humans depend on stress type, intensity, and duration. Animal models of social stress serve as good ways to mimic stress experienced in humans. However, the available stress paradigms pay little attention to the relationship between the intensity and the type of social stressors. The aim of the present work is to study behavioral and endocrinological consequences of social stress by varying the intensity and type of agonistic social contacts. Subjects were exposed to the attacks of an experienced fighter resident rat once a day for 4 consecutive days. Mild versus strong effects were studied by varying the length of daily confrontations (30 min vs. 4 h). The type of social confrontations was varied by ceasing or maintaining sensory contacts among contestants between encounters. Endocrinological variables were measured on the 5th day. Anxiety was assessed by means of the elevated plus-maze. The stress state depended on the length of daily encounters: 30-min encounters did not, whereas 4-h encounters did result in weight loss and chronic elevation of plasma corticosterone. The type of contacts between subjects and dominants also affected the resulting stress state: adrenal hypertrophy was obtained only when contacts between contestants were maintained between encounters. Although the mildest stress procedure (30-min encounters on 4 consecutive days) did not affect endocrinological variables, it resulted in subtle behavioral modifications that changed the anxiety-related effects of additional acute stressors. Thus, anxiety-related behavioral changes resulting from repeated mild stressors may be hidden factors that can have long-term consequences on the development of anxiety-like behavioral deficits. Results outline the necessity of studying the effects of social stressors of different intensities and different types.
Adrenal Glands↗
The vitamin status and its adequacy in the elderly: an international overview.
Age-related changes in nutrition can affect the nutritional status of the elderly in a number of ways. Food intake is affected by socio-economic, physiological and pathological factors. The major physiological age-related change is the decrease in the energy requirement due to a reduction in lean body mass and a reduction in physical activity leading to a compensatory decrease in macro- and micronutrient intake of approximately 30% by the age of 80 years. Morbidity and some types of medication, smoking and alcohol consumption also affect the absorption and metabolism of vitamins. The plasma levels of fat-soluble vitamins and carotenoids tend to increase with age with the exception of vitamin D, while certain water-soluble vitamin levels decrease, particularly vitamin B6 and vitamin B12. Many epidemiological studies have examined the vitamin intake and the plasma concentrations of large elderly populations in many regions of the world, but few have specifically determined the incidence of vitamin deficiencies. The criteria for defining deficiency varies between studies making it difficult to compare data from different studies. In the SENECA Study on European elderly evidence for biochemical vitamin deficiency was found in 47% for vitamin D, 23.3% for vitamin B6, 2.7% for vitamin B12 and 1.1% for vitamin E.
Aged↗
Catecholaminergic involvement in the control of aggression: hormones, the peripheral sympathetic, and central noradrenergic systems.
Noradrenaline is involved in many different functions, which all are known to affect behaviour profoundly. In the present review we argue that noradrenaline affects aggression on three different levels: the hormonal level, the sympathetic autonomous nervous system, and the central nervous system (CNS), in different, but functionally synergistic ways. Part of these effects may arise in indirect ways that are by no means specific to aggressive behaviour, however, they are functionally relevant to it. Other effects may affect brain mechanisms specifically involved in aggression. Hormonal catecholamines (adrenaline and noradrenaline) appear to be involved in metabolic preparations for the prospective fight; the sympathetic system ensures appropriate cardiovascular reaction, while the CNS noradrenergic system prepares the animal for the prospective fight. Indirect CNS effects include: the shift of attention towards socially relevant stimuli; the enhancement of olfaction (a major source of information in rodents); the decrease in pain sensitivity; and the enhancement of memory (an aggressive encounter is very relevant for the future of the animal). Concerning more aggression-specific effects one may notice that a slight activation of the central noradrenergic system stimulates aggression, while a strong activation decreases fight readiness. This biphasic effect may allow the animal to engage or to avoid the conflict, depending on the strength of social challenge. A hypothesis is presented regarding the relevance of different adrenoceptors in controlling aggression. It appears that neurons bearing postsynaptic alpha2-adrenoceptors are responsible for the start and maintenance of aggression, while a situation-dependent fine-tuning is realised through neurons equipped with beta-adrenoceptors. The latter phenomenon may be dependent on a noradrenaline-induced corticosterone secretion. It appears that by activating very different mechanisms the systems working with adrenaline and/or noradrenaline prepare the animal in a very complex way to answer the demands imposed by, and to endure the effects caused by, fights. It is a challenge for future research to elucidate how precisely these mechanisms interact to contribute to functionally relevant and adaptive aggressive behaviour.
Aggression↗
The hypothalamus: cross-roads of endocrine and behavioural regulation in grooming and aggression.
Anatomical and functional studies show that the hypothalamus is at the junction of mechanisms involved in the exploratory appraisal phase of behaviour and mechanisms involved in the execution of specific consummatory acts. However, the hypothalamus is also a crucial link in endocrine regulation. In natural settings it has been shown that behavioural challenges produce large and fast increases in circulating hormones such as testosterone, prolactin, corticotropin and corticosterone. The behavioural function and neural mechanisms of such fast neuroendocrine changes are not well understood. We suggest that behaviourally specific hypothalamic mechanisms, at the cross-roads of behavioural and endocrine regulation, play a role in such neuroendocrine changes. Mild stimulation of the hypothalamic aggressive area, produces stress levels of circulating prolactin, corticotropin, and corticosterone. Surprisingly luteinizing hormone does not change. This increase in stress hormones is due to the stimulation itself, and not caused by the stress of fighting. Similar increases in corticosterone are observed during electrical stimulation of the hypothalamic self-grooming area. The corticosterone response during self-grooming-evoking stimulation is negatively correlated with the amount of self-grooming observed, suggesting that circulating corticosterone exerts a negative feedback control on grooming. Earlier literature, and preliminary data form our laboratory, show that circulating corticosterone exerts a fast positive feedback control over brain mechanisms involved in aggressive behaviour. Such findings suggest that the hormonal responses caused by the activity of behaviourally specific areas of the hypothalamus may be part of a regulation mechanism involved in facilitating or inhibiting the very behavioural responses that can be evoked from those areas. We suggest that studying such mechanisms may provide a new approach to behavioural dysfunctions associated with endocrine disorders and stress.
Aggression↗
Acute effects of glucocorticoids: behavioral and pharmacological perspectives.
There has been evidence since the early eighties that glucocorticoids, apart from their well known chronic effects, may have acute, short-term effects. However, a lack of understanding of the molecular mechanisms of action has hampered appreciation of these observations. Mounting evidence over the years has continued to confirm the early observations on a fast corticosterone control of acute behavioral responses. We summarize experimental data obtained mainly in rats but also in other species which show: (1) that glucocorticoid production is sufficiently quick to affect ongoing behavior; (2) that there exist molecular mechanisms that could conceivably explain the fast neuronal effects of glucocorticoids (although these are still insufficiently understood); (3) that glucocorticoids are able to stimulate a wide variety of behaviors within minutes; and (4) that acute glucocorticoid production (at least in the case of aggressive behavior) is linked to the achievement of the behavioral goal (winning). The achievement of the behavioral goal reduces glucocorticoid production. It is argued that glucocorticoids are regulatory factors having a well-defined behavioral role. Both the acute (stimulatory) effects and the chronic (inhibitory) effects are adaptive in nature. The acute control of behavior by corticosterone is a rather unknown process that deserves further investigation. The pharmacologic importance of the acute glucocorticoid response is that it may readily affect the action of pharmacologic agents. An interaction between acute glucocorticoid increases and noradrenergic treatments has been shown in the case of offensive and defensive agonistic behavior. Non-behavioral data demonstrate that acute increases in glucocorticoids may interfere with other neurotransmitter systems (e.g., with the 5HT system) as well. These observations show the importance of taking into account endocrine background and endocrine responsiveness in behavior pharmacological experiments.
Animals↗
Risk factors for hemiretinal vein occlusion: comparison with risk factors for central and branch retinal vein occlusion: the eye disease case-control study.
OBJECTIVE: Possible risk factors for hemiretinal vein occlusion were identified and compared with risk factor profiles for central and branch retinal vein occlusion. DESIGN: The design was a multicenter case-control study. METHODS: The authors identified 79 patients with hemiretinal vein occlusion (HRVO), 258 patients with central retinal vein occlusion (CRVO), 270 patients with branch retinal vein occlusion (BRVO), and 1142 control subjects at 5 clinical centers. Risk factor data were obtained through interviews, clinical examinations, and laboratory analyses of blood specimens. RESULTS: Systemic hypertension and history of diabetes mellitus were associated with increased risk of HRVO. Risk of CRVO increased with history of diabetes, systemic hypertension, and higher erythrocyte sedimentation rate (females only); risk of CRVO decreased with increasing amounts of physical activity and increasing amounts of alcohol consumption. Systemic hypertension, higher body mass index, and higher alpha2-globulin levels were associated with increased risk of BRVO, whereas higher high-density lipoprotein levels and increasing levels of alcohol consumption were associated with decreased risk of BRVO. Glaucoma history was associated with all three types of retinal vein occlusion. CONCLUSION: Patients presenting with retinal vein occlusion should be evaluated for cardiovascular disease, diabetes, and glaucoma.
Adult↗
MR imaging in shoulder trauma. Value of STIR images.
PURPOSE: To determine the adequacy of MR standard protocols by analyzing conventional T1- and T2-weighted SE sequences, and to evaluate the usefulness of additional fat-suppressed (STIR) images in shoulder trauma. MATERIAL AND METHODS: Paracoronal T1-weighted, T2-weighted, SE, and STIR images were obtained on a 0.5 T superconductive system in 25 patients with shoulder trauma. In a separate evaluation of T1/T2 images and a combined evaluation of T1/T2 SE- and STIR images, we compared the number of patients with evidence of Hill-Sachs lesions, bone bruises, and/or rotator-cuff lesions. RESULTS: Compared to the combined evaluation of T1/T2 and STIR images, the separate evaluation of T1/T2 SE images revealed identical results for rotator-cuff lesions and Hill-Sachs lesions, but different results for the bone bruises in the area of the major tubercle. CONCLUSION: Occult fractures of the major tubercle, indicated by areas of bone bruising, might be missed with MR using conventional SE images. We recommend the use of additional paracoronal fat-suppressed sequences in patients with clinically suspected lesions and equivocal findings on plain radiographs and on standard SE sequences.
Adult↗
Aggressive experience affects the sensitivity of neurons towards pharmacological treatment in the hypothalamic attack area.
Early investigators of brain stimulation-evoked complex behaviours (attack, escape, feeding, self-grooming, sexual behaviour) reported that experience may affect the behavioural outcome of brain stimulation. This intriguing example of functional neuronal plasticity was later totally neglected. The present experiment investigated the behavioural outcome of in vivo microdialysis perfusion of the glutamate agonist kainate and/or the GABAA antagonist bicuculline into the hypothalamic attack area (HAA) of (1) animals naive to dyadic encounters; (2) animals with a recent aggressive experience (the probe being implanted 6-24 h after the last of a series of dyadic encounters); and (3) animals with an earlier aggressive experience (probe being implanted 2 weeks after the last aggressive experience). On the experimental day, rats received two 5-min infusions during a dyadic encounter lasting 35 min with an unknown opponent. Flow rate was 1.5-2 microliters/min, drug concentrations were 1.8 x 10(-5) and 1.5 x 10(-5) M for kainate and bicuculline, respectively. Behaviour was analysed before, during and after perfusions. Only the combined kainate + bicuculline treatment had significant effects on behaviour at the doses studied. A significant increase in aggressive behaviour was elicited only in animals with a recent aggressive experience, while naive animals and with an earlier experience responded to the treatments by grooming. These results appear to support early observations indicating that one important aspect of brain stimulation effects is previous experience.
Aggression↗
Mineralocorticoid receptor blockade inhibits aggressive behaviour in male rats.
Previous experiments have demonstrated that aggressive behaviour of male rats in a territorial setting is facilitated by corticosterone. Moreover, the inhibition of the endogenous corticosterone response prevents agonistic behaviour. The aim of the present paper was to investigate the effect of mineralocorticoid receptor (MR) blockade on the expression of aggressive behaviour at the beginning of the dark phase, when MRs are mostly occupied due to the diurnal peak of corticosterone secretion. High levels of aggressive behaviour were induced in male Wistar rats cohabiting with females by exposing them 3 times to an intruder male rat of smaller size. Intruder males were introduced at the beginning of the active period on every second day for 20 minutes, while the female was temporarily removed. A gradual increase in the number of biting attacks was noticed, the rats performing 6.7 +/- 2.0 attacks per 20 min on the last day (n=8). One hour before the fourth encounter rats were injected with the MR blocker spironolactone (10 mg/kg). Attacking behaviour was almost totally abolished (0.87 +/- .35 attacks per 20 min; n=8). Vehicle injections were ineffective (9.3 +/- 2.1 attacks per 20 min; n=8). Offensive threats underwent similar changes while other behaviours showed non-significant variation, with the exception of resting which increased towards the end of the observation period. The time course of these effects showed that the primary action was on offensive aggressive behaviour. This report is the first to show that the almost total MR occupancy at the beginning of the dark (active) period of the day is a prerequisite for the expression of aggressiveness in response to a social challenge.
Aggression↗
Ageing, nutritional status and immune response.
The effects of vitamin supplementation on the age-related decline in immune function was studied in a population of elderly subjects with a high prevalence of low and deficient serum values of vitamin C, vitamin E, riboflavin and pyridoxin, as well as iron and zinc. The immune function was examined by measuring delayed cutaneous hypersensitivity (DCH) after intradermal application of a set of 7 antigens in 72 subjects aged 60-89 years living in two homes for the elderly. The results showed an almost linear statistically significant decline in the DCH test with age (p < 0.01). Vitamin supplementation for a period of 10 weeks significantly improved the biochemical parameters for those vitamins and the age related decline in the DCH test was no longer statistically significant (P > 0.05). No statistically significant changes in DCH were observed in the placebo group. The results of this study suggest that nutrition may be an important determinant of immunocompetence in the elderly.
Aged↗
Thiamine supplementation mood and cognitive functioning.
One hundred and twenty young adult females took either a placebo or 50 mg thiamine, each day for 2 months. Before and after taking the tablets, mood, memory and reaction times were monitored. An improvement in thiamine status was associated with reports of being more clearheaded, composed and energetic. The taking of thiamine had no influence on memory but reaction times were faster following supplementation. These influences took place in subjects whose thiamine status, according to the traditional criterion, was adequate.
Adult↗
The mechanism of action of alpha 2 adrenoceptor blockers as revealed by effects on open field locomotion and escape reactions in the shuttle-box.
The precise mechanism of action of alpha 2 adrenoceptor blockers in not known, although in principle they have two main effects: (i) they stimulate the norepinephrinergic system by inhibiting the negative feed back of norepinephrine release (presynaptic effect) and (ii) they inhibit the effects of norepinephrine on postsynaptic alpha 2 adrenoceptors. We postulate that if the presynaptic actions of the antagonists prevail, the enhanced norepinephrine release leads to an activation of postsynaptic alpha 1 or beta adrenoceptors. In this case the effects of alpha 2 adrenoceptor blockers can be reversed by antagonists acting on the latter two adrenoceptors, since postsynaptic alpha 2 adrenoceptors are also blocked. If the postsynaptic blockade of alpha 2 adrenoceptors is the main cause of effects, than the blockade of alpha 1 or beta adrenoceptors should not reverse the action of alpha 2 blockers. The alpha 2 blocker idazoxan (dose 0.5-5 mg/kg) increased locomotor activity in an open field, an effect that was abolished by both alpha 1 and beta receptor blockers (prazosin and propranolol, respectively). Escape responses in a shuttle box were strongly suppressed by idazoxan (0.5-2 mg/kg). However, this effect was not changed by concomitant alpha 1 or beta receptor blockade. These results suggest that the mechanism of action of alpha 2 adrenoceptor blockers depends on which effects are studied. Exploration seems to be affected by a presynaptic mechanism as neurons bearing postsynaptic alpha 1 or beta adrenoceptors are involved in the control of this behavior, while escape reactions appear to be affected by the postsynaptic blockade of alpha 2 adrenoceptors (i.e. neurons bearing postsynaptic alpha 2 adrenoceptors are involved in its control). Thus, there is no generalized mechanism of action for alpha 2 adrenoceptor blockers; their precise mode of action should be investigated in each particular case.
Adrenergic alpha-2 Receptor Antagonists↗
Acute behavioural effects of corticosterone lack specificity but show marked context-dependency.
Rats were injected intraperitoneally with corticosterone (1 mg/kg). Ten min later they were submitted to dyadic encounters for 15 min. Rats naive to aggressive encounters responded to the corticosterone treatment by a reduction in resting times and an increase in exploration directed towards the novel environment. Resident rats acquainted with aggressive encounters responded to the treatment by a reduction of resting and an increase in threat behaviours. In resident rats acquainted with aggressive encounters and reared previously with a female an increase in attack frequency was noticed. It is concluded that an acute increase in blood corticosterone results in a stimulation of behaviour during social challenge, however, the specific effect is highly context dependent. These data confirm sporadic reports that noticed a behavioural stimulatory effect of acute corticosterone treatments. However, as far as a social challenge situation is concerned, the effect of corticosterone seems to be rather context then behaviour specific. Since corticosterone is known rather to change neuronal excitability than to activate neurons by itself, one can hypothesize that the context dependency of the effect is determined by the different configuration of activated centres in different situations. Attack may be stimulated by corticosterone only when centres involved in attack are already activated, that is, when a high frequency of attack is already present.
Aggression↗