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Results for “scratching”

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At least 361 records · Page 20Linked to original sources

PubMed2001

Effects of olopatadine hydrochloride on the cutaneous vascular hyperpermeability and the scratching behavior induced by poly-L-arginine in rats.

Intradermal injections of poly-L-arginine induce cutaneous vascular hyperpermeability and scratching behavior in rats. Recently, we elucidated that the plasma extravasation involved both histamine and substance P, while the scratching behavior involved substance P, but not histamine. This study examined the effects of olopatadine hydrochloride (olopatadine), an antiallergic drug with histamine H1-antagonistic action, on the poly-L-arginine-induced responses. Olopatadine (1 mg/kg, p.o.) significantly inhibited both the plasma extravasation and the scratching behavior, suggesting that its inhibitory effects are mediated by the suppression of neuropeptidergic action as well as histaminic action. Olopatadine seems to be a novel-type drug for the treatment of dermatitis.

Animals↗

PubMedDate not supplied

Evaluation of scratches as an essential element in the development of avian cellulitis in broiler chickens.

Currently, the published cellulitis models do not adequately address the actual pathogenesis as seen in the commercial broiler industry. In this model, small dermal scratches were made on the skin of broiler chickens, which were then placed on litter seeded with avian cellulitis-associated Escherichia coli. The research confirms scratches are required for the induction of avian cellulitis. The research also confirms that "type I" cellulitis lesions or those previously thought to be due to hatchery-borne infections can be induced with scratches. The described methods provide a realistic model for cellulitis development that will improve the reliability of prophylactic and therapeutic-regimen efficacy testing data, thereby providing information more directly useful to the commercial broiler industry.

Animal Husbandry↗

PubMed2002

Localization of sensorimotor cortex by using functional magnetic resonance imaging: comparison between finger tapping and palm scratching in normal volunteer.

The purpose of this study was to compare the location and intensity of activation of the sensorimotor cortex between finger tapping and palm scratching paradigms in normal volunteers and to consider using passive task instead of motor task in patients who are unable to perform motor task. Multishot echo-planar T2*-weighted imaging sequences at the level of the sensorimotor cortex were performed in axial plane during finger tapping and palm scratching paradigms in 13 normal volunteers. The authors found that the location of activation was slightly posterior only in bilateral passive task compared to bilateral motor task but there was no statistical significance. However, this observation was not seen in unilateral tasks. The intensity of activation of both motor and passive tasks was comparable. The authors conclude that in normal volunteers passive task (palm scratching) can be used instead of motor task (finger tapping) to localize the location of the sensorimotor cortex.

Adult↗

PubMed1990

[Changes in the quantitative characteristics of the efferent activity of the scratching generator when the influence of the descending systems is removed].

The effects of signals coming from descending systems of the spinal cord on parameters of the activity of scratching generators were investigated on the decerebrated immobilized animals. It was shown that the removal of modulation influences of the cerebellum on the nuclei of descending systems (decerebellation) caused changes in the ratio of the activity of the generator half-centres, rose instability of the generator work, weakened the statistical dependence between changes in parameters of the activity of the generator half-centres and strengthened the generators sensitivity to afferent signals. The total removal of influences of descending systems (after decapitation) induced reduction of the intensity of the efferent activity and afferent sensitivity of the scratching generator. The functional role of descending signals in the work of the scratching generator is discussed.

Afferent Pathways↗

PubMed1987

[Changes in the excitability of motor neurons and synaptic effects on them during formation of the generator of scratching movements in the cat].

It is shown that the state of the segmental apparatus of the lumbal spinal cord of immobilized intercollicularly decerebrated cats during formation of a scratching generator is essentially different from that of a spinal animal. The excitability of "aiming" and "scratching" motoneurons increases, recurrent and reciprocal Ia inhibition of motoneurons becomes stronger and influence of Ib afferents weaker. The flexor reflex afferents exert inhibitory influences on "aiming" motoneurons. After spinalization these influences become excitatory, and the inhibitory influences on "scratching" motoneurons become weaker. The functional role of described changes is discussed.

Animals↗

PubMed1988

Use of narcotic antagonists to modify stereotypic self-licking, self-chewing, and scratching behavior in dogs.

We evaluated 2 narcotic antagonists, naltrexone and nalmefene, for treatment of refractory self-licking, self-chewing, and scratching behavior in dogs. Eleven dogs with various irritative or pruritic disorders were medicated with naltrexone (1 mg/kg of body weight, sc) or nalmefene (1 to 4 mg/kg, sc), after a period of control observation during which the dogs had not been medicated. The time for which the dogs were involved in self-licking, self-chewing, or scratching was determined retrospectively by analysis of videotapes. The rates of involvement in either activity before and after treatment were calculated and compared statistically. Treatment with a narcotic antagonist significantly reduced the time spent self-licking, self-chewing, or scratching in 7 of 11 dogs, was partially effective in 3 dogs, and was ineffective in one dog. Dogs with acral lick dermatitis responded most to treatment.

Animals↗

PubMed1988

Lack of transmission of HIV through human bites and scratches.

To examine the relative risk of transmission of the human immuno-deficiency virus (HIV) through bites and scratches, we studied 198 health care workers, 30 of whom were traumatized in this fashion while caring for an aggressive AIDS patient. This violent patient frequently bit or scratched others, his mouth had blood and saliva, while his fingernails were at times soiled with semen, feces, and urine. He was HIV antibody and antigen positive. Although HIV was recovered from his peripheral blood lymphocytes, after 2.5 years of serial follow-up, all traumatized personnel were clinically normal, no HIV was cultured from their blood, and all were HIV antibody and P24 antigen negative. We conclude that this viremic AIDS patient, while producing copious amounts of body fluids, failed to infect those caring for him through bites and scratches. The risk of transmission of HIV through this route under similar conditions should be low.

Acquired Immunodeficiency Syndrome↗

PubMed1988

[Changes in the intensity of integral afferent inflow from limb receptors and the level of polarization of primary afferent endings in the decerebrate cat during scratching].

The experiments performed on decerebrated cats have shown that afferent activity during scratching consisted of two components--tonic and periodic phasic ones. The first component was determined by the limb position, the second was closely related to the amplitude and velocity of joint angle changes. Maximum of integral afferent activity in the cycle coincided with the scratching jerk phase. These two components of afferent activity evoked corresponding depolarization changes in primary afferent terminals and these changes added to those elicited by central generator. Statistical correlations between the aforementioned parameters were studied. The afferent control mechanisms of scratching generator are under discussion.

Action Potentials↗

PubMed1979

Effects of trimeprazine and trimipramine on nocturnal scratching in patients with atopic eczema.

Twelve men with severe and long-standing atopic eczema were admitted to a double-blind trial to establish the effects of trimeprazine tartrate, trimipramine maleate, and placebo on nocturnal scratching. Neither of the drugs altered the likelihood of a scratching bout beginning in wakefulness or in any stage of sleep. However, both drugs, especially trimipramine, made sleep less broken, and the reduced time spent in stage 1 of sleep accounted for a modest reduction in the overall amount of scratching during the night.

Adult↗

PubMed1985

[Depolarization of primary afferents during real scratching in the cat].

Changes in depolarization of primary afferents and their correlation with afferent impulsation and limb movement were studied in the lumbar spinal cord during real scratching of decerebrated cats. Two components in rhythmic dorsal root potential were observed. First--centrally evoked, retained during fictitive scratching after immobilization; second--evoked by afferent discharge, coming to the spinal cord during the scratching phase of the limb movement.

Animals↗

PubMedDate not supplied

[Postnatal development of the scratch reflex in rabbits].

The development of the scratch reflex was studied in newborn (up to 2 months old) rabbits in norm and after elimination or activation of some parts of their nervous system (reticular formation, cerebellum, caudate nucleus, cerebral cortex, superior cervical sympathetic ganglia). The experiments with the section of the brain stem at the border between the medulla and the midbrain showed that in very young (5-10 days old) rabbits in norm the scratch reflex is controlled by the spinal cord with no influences of structures situated above the section's level. Later on the spinal mechanism of the scratch reflex becomes subject to supraspinal influences, among which in 2-3 weeks old animals facilitatory effects are predominant produced, in particular, by the reticular formation and the cerebellum, whereas in older age prevail inhibitory influences of the cerebral cortex, cerebellum, caudate nucleus and the sympathetic nervous system.

Animals↗

PubMed1979

[Depolarization of the terminals of different groups of afferent fibers of the lumbar region of the spinal cord during fictive scratching].

Kinetics of lumbar primary afferent depolarization was investigated during fictitious scratching of decerebrated and decapitated cats. Fictitious scratching was accompanied by tonic and phasic primary afferent depolarization. Periodic depolarization of primary afferents was synphasic in different segments of the lumbosacral spinal cord. Tonic depolarization was observed in the terminals of all the investigated groups of fibres (low-threshold cutaneous and of groups 1a and 1b). Phasic changes took place in terminals of low-threshold cutaneous fibres and fibres of group 1b. Physiological significance of modulation of primary afferent depolarization by the spinal scratching generator is discussed on the basis of the data obtained.

Animals↗

PubMed1978

[Depolarization of primary afferents during fictitious scratching of thalamic cats].

The cord dorsum and dorsal root potentials were recorded during fictious scratching in L6 segment of the thalamic cats. It is shown that primary afferent depolrization (PAD) can be modulated by the central generator of scratching. In some afferent fibres antidromic spikes appear on the top of PAD-waves. Antidromic spikes can be also evoked in the period of "rest" by mechanical stimulation of hindlimb receptors. It is supposed that PAD and resulting antidromic spikes which appear during real scratching may effectively control the level of afferent inflow to the spinal neurons.

Animals↗

PubMedDate not supplied

[Activity of lateral reticular nucleus neurons during scratching].

The activity of neurones of the lateral reticular nucleus (LRN) was recorded in thalamic cats immobilized with Flaxedil during "fictitious scratching", that is during rhythmical activity of motoneurones typical of normal scratching. The LRN neurones exhibited a distinct modulation of their discharge related to the rhythmical activity of motoneurones in spite of the absence of the rhythmical afferent inflow. The pattern of modulation was identical both in normal and in "fictitious" scratching. Therefore, the spino-reticulo-cerebellar path transmits information about the activity of the spinal motor centres.

Animals↗

PubMedDate not supplied

[Activity of reticulospinal neurons during the scratch reflex].

The activity of reticulo-spinal (RS) neurons was recorded in thalamic and decerebrate cats during actual and "fictition" scratching. Most RS neurons were silent during scratching, but some exhibitied a distinct modulation of their discharge related to the rhythmical activity of motoneurons. They were excited during the flexor phase and inhibited during the extensor phase of the cycle. The pattern of modulation was identical both in actual and in "fictitions" scratching.

Animals↗

PubMedDate not supplied

[Behavior therapy technics in the treatment of endogenous eczema with special reference to compulsive scratching].

An exact observation and description of scratching behavior leads to a behavioral model for the obsessional scratching in patients with atopic dermatitis. The patient who cannot handle negative emotions because of a deficit in social behavior strategies suffers from diffuse tension. He can reduce the tension for the moment by scratching. Thus itching is being reinforced. The feeling of misbehavior occurs with delay and then again can serve as a stimulus for more tension.--Basing on this model behavior therapeutical techniques for breaking up this vicious circle are discussed.

Anxiety↗

PubMed1998

[Food and food additives hypersensitivity in adult asthmatics. I. Skin scratch test with food allergens and food challenge in adult asthmatics].

OBJECTS: The aim of this study was to investigate in adult asthmatics, which kinds of food allergen can cause a positive reaction by skin scratch test and cause symptoms when administered as a food challenge. SUBJECTS AND METHOD: Three thousand one hundred and two adult asthmatic patients were submitted to skin scratch tests with housedust mite. Japanese cedar extracts and 33 types of food. Sixty one adult asthmatic patients with a history of immediate, adverse reactions after food ingestion underwent open food challenge. RESULT: Six hundred and twenty five of 3102 subjects (20.1%) had a positive test to one or more food allergens. The commonest food allergens were shrimp (27.7%), crab (27.7%), yeast (23.8%) and buckwheat (15.8%). The positive tests of shrimp, egg and cow's milk were highest in patients under 20 years and decreased with age, however the test rates of crab and soybean were not influenced by age. Positive food challenge responses occurred in 30/60 subjects (50%). The foods, which most of ten provoked a reaction, were buckwheat, shrimp, crab and bread. CONCLUSION: Skin scratch test results in adult asthmatics were different from those in atopic children where the commonest foods with positive tests were egg, cow's milk and soybean. Except for patients with a previous life-threatening reaction. Food allergy should be diagnosed by food challenge where a patient's history of adverse reaction to food, positive skin test and RAST strongly support specific food reactivity.

Adult↗

PubMed1955

Pathology of cat-scratch disease.

A pathologic and histogenetic study of material obtained from ten cases of cat-scratch disease was carried out. The earliest lesion was of ten days' duration and the oldest of 35 days' duration. The first changes in lymph nodes consisted of proliferation of epithelioid cells followed by exudation of leukocytes in their centers and subsequent necrosis of the exudate and epithelioid cells. Proliferative changes leading to formation of epithelioid cell tubercles were seen in some cases. Homogenization of necrotic centers brought about the formation of caseous tubercles similar to those seen in tuberculosis, syphilis, lymphogranuloma venereum and tularemia. Differentiation and the final diagnosis of cat-scratch disease rests upon correlation of histopathologic observations, clinical studies and specific skin tests.

Cat-Scratch Disease↗