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PubMed2004

Scratching of their skin by NC/Nga mice leads to development of dermatitis.

Effects of scratching behavior on dermatitis, transepidermal water loss (TEWL) and serum IgE concentrations were examined in NC/Nga (NC) mice with toenails (WIT) and without toenails (WOT). The first study was a preventive treatment done to cut off hind toenails before dermatitis induction and the second study was a therapeutic treatment by cutting off hind toenails of NC mice with severe dermatitis. In the preventive study, scratching behavior significantly increased in both WIT and WOT after dermatitis induction. Skin severity score, TEWL, number of mast cells and serum IgE concentration statistically increased in WIT but not in WOT after dermatitis induction. Histological changes coincided with the skin severity score in WIT, while no changes were observed in WOT. In the therapeutic study, skin severity score in WOT but not in WIT statistically decreased after cutting off the hind toenails. TEWL and numbers of mast cells in WOT were statistically lower compared with findings in WIT. Thus scratching up the skin with toenails seemed to be the most important factor leading to dermatitis in NC mice.

Animals↗

PubMed1999

The effects of the phyllolitorin analogue [desTrp(3), Leu(8)]phyllolitorin on scratching induced by bombesin and related peptides in rats.

Bombesin along with several closely related neuropeptides elicit scratching behavior when administered centrally. The first part of the study was designed to determine the antagonistic effects of a novel phyllolitorin analogue [desTrp(3),Leu(8)]phyllolitorin (DTP) on scratching induced by three peptides (bombesin, neuromedin-C, and [Leu(8)]phyllolitorin). In addition, the binding affinity of each peptide for the bombesin receptor site was determined. DTP (30 microg) inhibited scratching induced by these peptides, but unlike the peptides, DTP had no affinity for the bombesin site, thereby suggesting that DTP is displaying physiological antagonism through an unknown mechanism.

Animals↗

PubMedDate not supplied

Finite element analysis of nanostructures with roughness and scratches.

Finite element analysis facilitates optimal design of MEMS/NEMS devices for reliability. A finite element method (FEM) was developed to analyze the effect of types of surface roughness and scratches on stresses of nanostructures. Beams with surface roughness in the form of semicircular and grooved asperities in varying numbers in the longitudinal direction were considered. In the transverse direction semicircular asperities and scratches in varying numbers and with different pitch were modeled. Furthermore semicircular asperities were truncated both in longitudinal and transverse direction and analyzed. It was observed that the asperities and scratches increase the bending tensile stresses which could lead to failure of MEMS/NEMS devices. The beam material was assumed to be purely elastic, elastic-plastic and elastic-perfectly plastic to observe the variations in the bending stresses and displacements for both smooth nanobeam and nanobeam with defined roughness. The results of the analysis can be useful to designers to develop the most suitable geometry for nanostructures.

Journal Article↗

PubMed2000

Neuroretinitis: a clinical syndrome of cat-scratch disease.

Cat-scratch disease is usually a benign self-limited illness, characterized by regional lymphadenopathy lasting between 3 and 6 weeks. The causative organism is Bartonella henselae, a small gram-negative rod. Between 1 and 2% of patients who contract the illness experience blurred vision, metamorphopsia and scotomas as a result of neuroretinitis, an associated clinical syndrome. The classical clinical findings in cat-scratch neuroretinitis include disc edema and a stellate pattern of exudates in the macula. However, a myriad of other signs has been documented, suggesting a much wider spectrum of intra-ocular disease. The following case report presents a young patient with neuroretinitis, and a history of lymphadenopathy secondary to cat-scratch disease.

Journal Article↗

PubMed2003

Generation and characterization of epidermolysis bullosa simplex cell lines: scratch assays show faster migration with disruptive keratin mutations.

BACKGROUND: Epidermolysis bullosa simplex (EBS) is an inherited skin fragility disorder caused by mutations in keratin intermediate filament proteins. While discoveries of these mutations have increased understanding of the role of keratins and other intermediate filaments in epithelial tissues, progress towards the development of therapy for these disorders is much slower. OBJECTIVES: Cell culture model systems that display these structural defects are needed for analysis of the cellular consequences of the mutations and to enable possible therapeutic strategies to be developed. Our aim was to generate immortalized cell lines as such model systems for the study of EBS. METHODS: We generated a series of stable cell lines expressing EBS-associated keratin mutations, by immortalizing keratinocytes from EBS-affected skin biopsies with either simian virus 40 (SV40) T antigen or human papillomavirus 16 (HPV16) E6/E7, and assessed their keratin expression (by immunofluorescence), proliferation rates and migratory behaviour (in outgrowth and scratch wound assays). RESULTS: Clonal immortalized keratinocyte cell lines KEB-1, KEB-2, KEB-3 (using SV40 T antigen) and KEB-4, KEB-7 and NEB-1 (using HPV16 E6/E7) were established. These include two lines from a single individual with Weber-Cockayne EBS (i.e. KEB-3 and KEB-4, mutation K14 V270M), and three cell lines from a second family, two from siblings carrying the same mutation (KEB-1, KEB-2 lines from Dowling-Meara EBS, mutation K5 E475G) and one from an unaffected relative (NEB-1). The sixth cell line (KEB-7), with a previously unreported severe mutation (K14 R125P), was the only one to show keratin aggregates in resting conditions. Despite variations in the immortalization procedure, there was no significant difference between cell lines in keratin expression, outgrowth capabilities or response to transient heat shock. However, cell migration, as measured by speed of scratch wound closure, was significantly faster in cells with severe EBS mutations. CONCLUSIONS: These cell lines provide useful culture systems in which to assess aspects of EBS-induced cell changes. The faster migration after scratch wounding of the EBS keratinocytes may be a consequence of the known upregulation of stress-activated kinase pathways in these cells.

Cell Division↗

PubMed1999

Pruritus: more scratch than itch.

Itch is one of the major symptoms of skin disease although it remains poorly studied. Little is known about its mediators or the neurological processes involved in either the detection of an itch stimulus or the induction of the main response to itch, scratch. This lack of knowledge may be due to the subjective nature of the sensation itself and the related difficulties in quantifying it, and is compounded by the absence of a convincing animal model. Defining itch as that sensation which provokes the desire to scratch provides two approaches to measurement, that of itch itself, and the behavioural response, scratch. The measurement of itch itself traditionally involves the use of questionnaires or visual analogue scale, both of which rely on the dubious assumption that the subject is able to relate their experiences accurately. By contrast experimental induction of itch and measurement of areas of allokinesis around application sites may provide a more reliable and repeatable method of itch quantification. Recent advances in two areas that may prove relevant are discussed: new technological improvements in movement meters and compatible software; and some recently described animal models.

Humans↗

PubMed1998

Detection of Onchocerca volvulus infection by O-150 polymerase chain reaction analysis of skin scratches.

The standard assay for onchocerciasis diagnosis is microscopic detection of parasites in skin snips. Skin snipping is painful and may potentially transmit bloodborne infections. Thus, an alternative method for the diagnosis of onchocerciasis that does not require skin snipping is needed. A polymerase chain reaction (PCR)-based assay was shown to detect the presence of parasite DNA in superficial skin scrapings. Detection of parasite DNA in both skin snips and skin scratches was found to be more sensitive for detecting low-density infections than was microscopic examination of skin snips. The skin scratch PCR assay is minimally invasive and painless and does not present the risk of transmitting bloodborne infections. These properties make the skin scratch an attractive alternative to the skin snip for detecting O. volvulus infection.

Adolescent↗

PubMed2005

Mycobacterium vaccae reduces scratching behavior but not the rash in NC mice with eczema: a randomized, blinded, placebo-controlled trial.

In a randomized, double-blinded, placebo-controlled trial, we previously showed that intra-dermal administration of a killed Mycobacterium vaccae suspension to school-aged children with atopic dermatitis ameliorates their disease. We wished to test the hypothesis that M. vaccae may also prevent the development of eczema. As it was not possible to do this in children, we studied the NC/Nga eczema mouse model. Thirty NC/Nga mice were randomized into a blinded, placebo-controlled trial where they received either 0.1 or 0.01 mg of M. vaccae (SRP299) or placebo given subcutaneously at 1 and 8 wk of age. Clinical eczema scores, as well as scratching frequency using a digital videotape system were assessed during the 26-wk study. Digital scratch scores correlated with clinical severity (p=0.001). Although there were no significant differences in age of onset or severity of the rash between the three study arms, mice injected with 0.1 mg but not 0.01 mg of SPR299 had significantly lower peak scratch frequencies than controls (Hazard ratio 0.2; 95% confidence interval 0.1-0.7; p=0.01). We conclude that in this NC/Nga mouse model, SRP299 did have a beneficial effect in reducing pruritus, a major clinical symptom of eczema, although it does not prevent the rash from developing.

Animals↗

PubMed1975

Emotions and skin (II)-the conditioning of scratch responses in cases of lichen simplex.

Lichen simplex is generally regarded as a condition initiated and perpetuated by scratching and emotional tension. It was felt that the scratching might partly be a conditional response to itching and other signals, and that feelings of guilt, anxiety and hostility would be prominent features in these patients. Conditioning experiments designed to establish scratch responses to an itch stimulus (UCS) and a tone (CS) showed that lichen simplex patients conditioned more readily and extinguished more slowly than controls. These finding were more marked when the itch stimulus was applied to affected as compared with normal skin. It was not possible to distinguish differences in the psychological tests between patients and controls. The possible significance of these findings is discussed.

Adolescent↗

PubMed1987

Scratch-chamber tests in food handler dermatitis.

Foods were tested by the scratch-chamber and open application techniques in 80 hand dermatitis patients, 55 of whom were food handlers. Both immediate and delayed reactions were seen. Most immediate scratch-chamber test reactions were provoked by vegetables and spices in patients with birch pollen allergy, and most delayed reactions from spices in patients with allergy to balsam of Peru, and from onion and leek. The evaluation of allergic and irritant reactions was difficult. Positive open application tests were seen in about 75% of patients with immediate or delayed scratch-chamber reactions. Immediate reactions from vegetables, fish and meat, and delayed reactions from orange and lemon peel and onion showed the best clinical relevance. Wet work, surface active agents and other irritant factors were considered the main causes, and food allergies as contributory factors only in food handler hand dermatitis.

Adolescent↗

PubMed2003

Timing of knee-related spinal neurons during fictive rostral scratching in the turtle.

Knee-flexor motor activity rhythmically alternated with knee-extensor motor activity during fictive rostral scratching in the spinal turtle. A critical transition from knee-flexor motor activity to knee-extensor motor activity occurred during hip-flexor motor activity. A key feature of this transition was that the end-phases of knee-flexor motor activity were positively correlated with the start-phases of knee-extensor motor activity. We studied spinal interneurons with activities related to this transition. We previously used single-unit recording techniques to characterize a data set of descending propriospinal interneurons during rostral scratching. We focused here on a group of interneurons from this data set with start-phases (on-units) or with end-phases (off-units) near the start of knee-extensor motor activity. We showed that, for a subset of these units, the start-phases of on-units and the end-phases of off-units were positively correlated with the start-phases of knee-extensor motor activity. We present the hypothesis that some of these knee-related on- and off-units may play a role in timing knee motor activity during rostral scratching.

Animals↗

PubMed1997

Right-left interactions between rostral scratch networks generate rhythmicity in the preenlargement spinal cord of the turtle.

We examined the rhythmogenic capacity of the midbody D3-D7 spinal cord during stimulation of the rostral scratch reflex in turtles. Fictive scratching was recorded bilaterally as electroneurograms (ENGs) from prehindlimb enlargement nerves [transverse D7 (TD7) and oblique D7 (OD7)] and hip flexor nerves (HF). TD7 and OD7 innervate transverse- and oblique-abdominus muscles, respectively. D3-end preparations had intact spinal cords caudal to a D2-D3 transection site. Unilateral stimulation of the rostral receptive field in D3-end preparations evoked rhythmic bursting in the ipsilateral (ipsi) HF nerve and bilateral rhythmic discharge in the TD7 and OD7 nerves. Right HF bursts were coactive with right TD7 and left OD7 bursts and alternated with left TD7 and right OD7 bursts. D3-D7 preparations received a second spinal transection at the caudal end of segment D7, thus resulting in activation of strictly preenlargement circuitry in response to rostral scratch stimulation and preventing activation of hindlimb enlargement circuitry in segments D8-S2. D3-D7 preparations responded to unilateral stimulation with modulated or tonic discharge in the ipsi TD7 and contralateral (contra) OD7 nerves. In contrast, bilateral stimulation reestablished robust bursting in which coactive right TD7-left OD7 bursts alternated with coactive left TD7-right OD7 bursts. These data imply that TD7 circuit modules make 1) crossed excitatory connections with contra OD7 circuitry, 2) crossed inhibitory connections with contra TD7 circuitry, and 3) uncrossed inhibitory connections with ipsi OD7 circuitry. Our results also suggest that bilateral stimulation evokes rhythmic alternation in the preenlargment cord by simultaneously exciting reciprocally inhibitory circuit modules.

Animals↗

PubMed1998

Example of 2:1 interlimb coordination during fictive rostral scratching in a spinal turtle.

The usual interlimb coordination pattern during fictive rostral scratching in turtles is 1:1 coordination. We describe an example in a turtle of 2:1 coordination during fictive rostral scratching in which there were two cycles of ipsilateral hip flexor activity during each cycle of contralateral hip extensor activity. During 2:1 coordination, there were fluctuations in the ipsilateral hip flexor cycle period such that a larger ipsilateral hip flexor normalized period, which was associated with the onset of a contralateral hip extensor burst, alternated with a smaller ipsilateral hip flexor normalized period, which was associated with the absence of the onset of a contralateral hip extensor burst. These observations support the concept that contralateral circuitry modulates the timing of ipsilateral motor rhythms and therefore contributes to the production of the ipsilateral motor pattern for rostral scratching.

Animals↗

PubMedDate not supplied

Anaplastic large cell lymphoma of the mediastinum diagnosed by transbronchial scratch cytology. A case report.

BACKGROUND: Anaplastic large cell lymphoma (ALCL) is a subtype of non-Hodgkin's lymphoma characterized by CD30 antigen-positive, large neoplastic cells. We describe a case of ALCL suggested by cytologic examination of the tumor cells obtained from bronchial scratch preparations. CASE: A 26-year-old woman had had a dry cough since November 1996. Chest radiography in May 1997 revealed an abnormal shadow in the mediastinum extending to the pulmonary hilar region. The patient was hospitalized in June 1997. Computed tomography revealed a neoplastic lesion in the anterior mediastinum invading the right lung. Transbronchial scratch cytology revealed large, atypical lymphoid cells expressing CD30 and CD3 on immunocytochemical examination. A transcutaneous mediastinal biopsy was performed and a diagnosis of ALCL made. CONCLUSION: Differentiation from Hodgkin's disease was the most difficult point in this case. Detailed cytologic observation and CD3-positive immunocytology led to the correct diagnosis. The cell transfer technique of Sherman et al was very useful for immunocytologic staining. Thus, transbronchial scratch cytology was an especially valuable and effective procedure in this case.

Adult↗

PubMedDate not supplied

Combined use of the "scratch and smear" sampling technique and Ultrafast Papanicolaou stain for intraoperative cytology.

OBJECTIVE: To assess the applicability of Ultrafast Papanicolaou stain (UFP), a 90-second, high-resolution stain incorporating the air-dried rehydration technique, to intraoperative cytology in surgical pathology laboratories. STUDY DESIGN: Two hundred sixty-two randomly selected surgical specimens for intraoperative consultations were included in the study. Each specimen was first conventionally prepared by touch imprinting, wet fixation in alcohol and staining by hematoxylin and eosin (H&E); the remaining specimens were then sampled by the "scratch and smear" technique and subjected to the UFP staining protocol. RESULTS: The combined use of the scratch and smear sampling technique and UFP staining was superior to the conventional methods of touch imprinting and H&E staining in every case because of the following features: (1) intact tissue fragments composed of both epithelial and stromal elements rather than epithelial cells only, (2) polychromasia rather than bichromasia, (3) sharper nuclear and cytoplasmic details, (4) histologic criteria applicable to thick tissue fragments due to transparency and flatness and (5) clear background devoid of red blood cells and eosin. CONCLUSION: The combined use of the "scratch and smear" sampling technique and UFP enhances intraoperative cytology.

Cytological Techniques↗

PubMed2006

A study of nano-mechanical properties and nano-scratch behavior of boron carbonitride films.

Boron carbonitride (BCN) films were deposited by d.c. unbalanced magnetron sputter deposition where a substrate bias ranging from -50 V to -300 V was applied to the sample. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used to confirm the composition and bonding structure of the BCN films. Surface morphology and roughness were analyzed by atomic force microscopy. The nano-mechanical properties and nano-scratch behavior of the prepared films were determined by a nano-indentation system equipped with continuous stiffness measurement and lateral-force measurement attachments. The results indicate that there is little change in the content of B, C, and N. The films deposited are compounds with hybridized B-C-N bonds and the disordered degree of the structure increases with increasing the substrate bias. The substrate biasing can enhance the nanohardness, elastic modulus, nano-scratch resistance, and cohesion strength of the deposited films. During the nano-scratch test, plastic deformation and ploughing wear appears for the BCN films deposited at lower bias. Elastic deformation becomes the dominant deformation mechanism for the films deposited at higher bias. The coefficient of friction between the deposited BCN films and the diamond tip depends on the loading critical load. The increasing of the substrate bias leads to the improvement of the critical load and the elastic deformation proportion.

Adhesiveness↗

PubMed1986

IgG levels after treatment with antigen vials based on the scratch testing, intradermal testing, modified RAST testing.

In this study, there were three groups of patients--each group consisting of four patients. The first group had been skin tested by the scratch method, the second group was skin tested by the end point titration intradermal method, and the third group had been tested for inhalant allergy by the modified RAST technique. All of them had multiple treatment vials made, dependent on the type of testing they had, and the vials all included the ten inhalants that were tested for. All patients had been treated for a year with weekly immunotherapy injections. Specific IgG levels, blocking antibody levels to the ten inhalant allergens, were determined. The results were that the patients who had been scratch tested had the lowest levels of specific IgG blocking antibody--while both intradermal end point titration and modified RAST testing had much higher elevations of blocking IgG antibody, with the RAST having the highest. It is concluded that, since the treatment vials prepared after scratch testing of all the antigens are at the same concentration, there are many antigens that are not given in adequate amounts to cause a good IgG response whereas, by calibrating the concentrations of antigens in the intradermal titration and the modified RAST testing, all the antigens are being injected in sufficient quantities to get a good blocking antibody response.

Desensitization, Immunologic↗

PubMed1994

Comparison of results of immunotherapy based on skin end-point titration, prick testing, and scratch testing.

Presented is a clinical study comparing the result of immunotherapy based on allergy testing with three different test modalities: skin end-point titration, prick testing, and scratch testing. Thirty patients with allergic rhinitis were randomly assigned to one of the three test groups. Treatment vials were made on test results according to the instructions for each test. For skin end-point titration, each antigen was included at a concentration based on the patient's sensitivity, found with the fivefold dilution testing procedure. For the prick test, treatment vials were based on a two-level test response scale of stronger or lesser positive results. The scratch test yields vials used in one concentration based simply on a positive vs. negative test result. Patients in all three groups were treated at weekly intervals with immunotherapy, progressing in volume until the maximum tolerated dose was achieved. Relief of symptoms was evaluated after 6 months of treatment. Nine of the 10 patients receiving skin end-point titration based immunotherapy had complete relief of symptoms, and one had partial relief. None of the patients in the prick or scratch test groups achieved relief of symptoms after 6 months of treatment. Results dramatically demonstrate the need to base allergy immunotherapy treatment on a test that quantifies the patient's level of sensitivity to each antigen.

Desensitization, Immunologic↗