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Results for “scratching”

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PubMed2003

Involvement of the Arp2/3 complex and Scar2 in Golgi polarity in scratch wound models.

Cell motility and cell polarity are essential for morphogenesis, immune system function, and tissue repair. Many animal cells move by crawling, and one main driving force for movement is derived from the coordinated assembly and disassembly of actin filaments. As tissue culture cells migrate to close a scratch wound, this directional extension is accompanied by Golgi apparatus reorientation, to face the leading wound edge, giving the motile cell inherent polarity aligned relative to the wound edge and to the direction of cell migration. Cellular proteins essential for actin polymerization downstream of Rho family GTPases include the Arp2/3 complex as an actin nucleator and members of the Wiskott-Aldrich Syndrome protein (WASP) family as activators of the Arp2/3 complex. We therefore analyzed the involvement of the Arp2/3 complex and WASP-family proteins in in vitro wound healing assays using NIH 3T3 fibroblasts and astrocytes. In NIH 3T3 cells, we found that actin and Arp2/3 complex contributed to cell polarity establishment. Moreover, overexpression of N-terminal fragments of Scar2 (but not N-WASP or Scar1 or Scar3) interfere with NIH 3T3 Golgi polarization but not with cell migration. In contrast, actin, Arp2/3, and WASP-family proteins did not appear to be involved in Golgi polarization in astrocytes. Our results thus indicate that the requirement for Golgi polarity establishment is cell-type specific. Furthermore, in NIH 3T3 cells, Scar2 and the Arp2/3 complex appear to be involved in the establishment and maintenance of Golgi polarity during directed migration.

3T3 Cells↗

PubMed1992

Lymphocutaneous Nocardia brasiliensis infection acquired from a cat scratch: case report and review.

Nocardia brasiliensis is a bacterium that is most commonly found in the soil. Traumatic inoculation of N. brasiliensis into the skin is the most typical mode of acquisition of infection due to this organism. To the best of my knowledge, I report the first case of lymphocutaneous N. brasiliensis disease from a penetrating cat scratch of the skin, thereby establishing cats as vehicles for the transmission of this infection. Treatment with penicillin produced a rapid resolution of all signs and symptoms of infection. The efficacy of penicillin against the N. brasiliensis isolate recovered from this patient was highly unusual. In general, penicillin has limited therapeutic value since these organisms elaborate beta-lactamase. Sulfonamides remain the drugs of choice for the treatment of these infections. These soil-borne organisms are most likely carried on the claws of cats and may establish infection after percutaneous inoculation. A high index of suspicion for N. brasiliensis soft-tissue infection is required since a delayed or missed diagnosis may be associated with progressive local disease and/or widespread disseminated infection.

Adult↗

PubMed1997

Use of random amplification of polymorphic DNA in a case of Pasteurella multocida meningitis that occurred following a cat scratch on the head.

We cultured Pasteurella multocida from the cerebrospinal fluid (CSF) of a 4-month-old infant who presented with meningitis. The patient had been scratched on the head by a cat. Culture of the cat's claws also yielded P. multocida. The isolates had identical biochemical patterns. Analysis of both strains by random amplification of polymorphic DNA and comparison of these strains with P. multocida strains isolated from other cats showed that the two strains were identical and completely different from the unrelated isolates. Our patient's meningitis most likely resulted from direct inoculation of P. multocida into the CSF.

Animals↗

PubMedDate not supplied

Developing clinical competencies/training checklists: when you have to start from scratch!

Where does an educator begin to develop competencies if the organization has not had formal written standards, has few clinical policies and procedures, or has not had consistent training checklists? The educator may have to begin from scratch. During a year-long process, 50+ clinical sites and 500+ clinical staff (nurses and medical assistants) played an active role in improving clinical orientation by assisting with the development of clinical competencies/ training checklists. This article outlines the development of the clinical competencies/ training checklists for the University of Wisconsin Medical Foundation (UWMF), Madison, Wisconsin.

Attitude of Health Personnel↗

PubMed1995

scratch, a pan-neural gene encoding a zinc finger protein related to snail, promotes neuronal development.

The Drosophila scratch (scrt) gene is expressed in most or all neuronal precursor cells and encodes a predicted zinc finger transcription factor closely related to the product of the mesoderm determination gene snail (sna). Adult flies homozygous for scrt null alleles have a reduced number of photoreceptors in the eye, and embryos lacking the function of both scrt and the pan-neural gene deadpan (dpn), which encodes a basic helix-loop-helix (bHLH) protein, exhibit a significant loss of neurons. Conversely, ectopic expression of a scrt transgene during embryonic and adult development leads to the production of supernumerary neurons. Consistent with scrt functioning as a transcription factor, various genes are more broadly expressed than normal in scrt null mutants. Reciprocally, these same genes are expressed at reduced levels in response to ectopic scrt expression. We propose that scrt promotes neuronal cell fates by suppressing expression of genes promoting non-neuronal cell fates. We discuss the similarities between the roles of the ancestrally related scrt, sna, and escargot (esc) genes in regulating cell fate choices.

Amino Acid Sequence↗

PubMed2006

Spontaneous scratching behaviour in DS-Nh mice as a possible model for pruritus in atopic dermatitis.

Itching is one of the major clinical symptoms in atopic dermatitis (AD) and complicates the management of this pathological condition. An animal model of AD-like pruritus would contribute to a better understanding of AD and could lead to the development of safe and effective antipruritic agents. DS non-hair (DS-Nh) mice raised under conventional conditions spontaneously develop pruritus, which is associated with a dermatitis similar to human AD. There is a significant positive correlation between disease severity and the period of scratching behaviour in DS-Nh mice. In the present study, we found that levels of histamine and nerve growth factor (NGF) in serum and/or skin tissue were higher in DS-Nh mice with AD-like dermatitis than in age-matched mice without dermatitis. The histopathological data indicated that nerve fibres extend into and mast cells infiltrate the surrounding area of the skin lesion. NGF production by XB-2 cells, which was derived from mouse keratinocytes, was enhanced by histamine via the H1 receptor. We also found that prolonged treatment with an H1-antagonist was effective against pruritus through depression of the production of NGF, which is thought to be generated by keratinocytes. We conclude that DS-Nh mice can serve as a suitable model for gaining a better understanding of pruritus in AD, and that prolonged treatment with an H1-antagonist may be beneficial in patients with AD-associated pruritus.

Animals↗

PubMed1990

The effects of substance P analogues on the scratching, biting and licking response induced by intrathecal injection of N-methyl-D-aspartate in mice.

1. Intrathecal (i.t.) administration of N-methyl-D-aspartate (NMDA) elicited a dose-dependent behavioural response consisting of licking, biting and scratching in mice. 2. Repeated i.t. injections of 0.4 nmol NMDA, at 5 min intervals, resulted in the rapid development of desensitization to this NMDA-induced behavioural phenomenon. 3. The NMDA-induced response was dose-dependently inhibited by the simultaneous injection of a selective NMDA-receptor antagonist, D-2-amino-5-phosphonovaleric acid. 4. The substance P (SP) analogues [D-Pro2, D-Trp7,9] SP and [D-Arg1, D-Trp7,9, Leu11] SP (spantide) inhibited NMDA-induced behavioural responses in a dose-dependent manner. However, [D-Phe7, D-His9] SP (6-11), a SP analogue selective for neurokinin1 (NK1) receptors, failed to inhibit NMDA-induced responses even at a dose of 4.0 nmol. 5. These results indicate that NMDA-induced behavioural responses are mainly mediated through NMDA receptors without affecting NK1 receptors in the spinal cord.

2-Amino-5-phosphonovalerate↗

PubMed1988

Pharmacological studies of grooming and scratching behavior elicited by spinal substance P and excitatory amino acids.

Compounds that produce depolarization of nociceptive neurons in the dorsal horn of the spinal cord also elicit a rather specific kind of caudally directed biting, licking, and/or scratching behavior when they are injected intrathecally in mice. We sought to use this elicited grooming behavior as a test for compounds that might inhibit the neurons excited by the excitatory agents. All three neurokinins--substance P, neurokinin A (substance K), neurokinin B (neuromedin K)--and excitatory amino acids active at N-methyl-D-aspartate (NMDA) or quisqualate receptors produce similar behaviors, which last for 1 minute after i.t. injection. Our data indicate that mu opioid agonists or alpha adrenergic agonists block both neurokinin-elicited behavior and EAA-elicited behavior; delta opioid agonists block only neurokinin-elicited behavior; and PCP/sigma "opioid" agonists block only EAA-elicited behavior. Somatostatin and serotonin produce qualitatively different behaviors by themselves and, when administered with neurokinins, partially block neurokinin-elicited behavior.

Amino Acids↗

PubMed2000

Profile: building a world-class lab from scratch.

In 1996, Projet RETRO-CI, a U.S.-Ivoirian collaboration funded by the U.S. Centers for Disease Control and Prevention, hired virologist John Nkengasong to build a virology lab from scratch. Now Nkengasong runs one of the best equipped HIV labs in sub-Saharan Africa and has published dozens of papers helping to clarify properties of specific strains of the virus.

Cote d'Ivoire↗

PubMed1994

Urge to scratch represented in the human cerebral cortex during itch.

1. We used functional positron emission tomography (PET), measuring regional cerebral blood flow (rCBF) as an index of neuronal activity, to investigate the central processing of itch in 10 healthy volunteers subjected to intracutaneous injections of histamine. 2. The study has unraveled a central representation that depicts a motor intention of the urge to scratch contingent on the perception of unpleasant itch. The coactivation of the anterior cingulate cortex (ACC), supplementary motor area (SMA), premotor area (PM), and inferior parietal lobule (IPL) substantiates that the posterior sector of the ACC (Brodmann 24) is related to the sensorial/affectional aspect of the event. The premotor cortical areas (SMA, PM) and the IPL may participate in the preparation of an intended action.

Adult↗

PubMed2002

LiCl attenuates M(1)AChR-mediated intrathecal pilocarpine-induced reciprocal hindlimb scratching in mice.

Pretreatment of mice with a subcutaneous (s.c.) injection of LiCl (1, 3, 10 mmol/kg) 18 h prior to testing produced dose-related attenuation of the reciprocal hindlimb scratching (RHS) response induced by intrathecal (i.t.) administration of pilocarpine. LiCl (10 mmol/kg, 424 mg/kg) pretreatment shifted the pilocarpine (2 microg)-induced RHS dose-response curve about 5-fold to the right compared to vehicle-injected controls (ED(50) = 2.97 and 0.56 microg, respectively). Coadministration of inositol-1,4,5-trisphosphate (IP(3); 5, 10, 20 microg), but not inositol hexaphosphate (0.03-3 microg), myo-inositol (10 microg) or EDTA (1.33 microg), produced dose-related reversal of the LiCl effect. IP(3) administration alone neither produced RHS nor enhanced the pilocarpine-induced RHS in animals not pretreated with LiCl. These findings provide in vivo evidence for a possible link between RHS and a LiCl-sensitive, possibly phosphoinositide-related, effector pathway.

Animals↗

PubMed2004

Itch-scratch responses induced by lysophosphatidic acid in mice.

The present investigation was conducted in order to determine whether lysophosphatidic acid (LPA) induces itch-scratch responses (ISRs) in mice. Intradermal administration of LPA induces ISRs; furthermore, the time course for LPA-induced ISRs was similar to that for histamine-induced responses. Comparative study of the pruritogenic activity revealed that histamine possessed a potent effect characterized by a dose-response relationship; however, prostaglandin D2 failed to induce this response. Pretreatment with ketotifen, a histamine H1 receptor antagonist, and capsaicin inhibited LPA-induced ISRs. Additionally, LPA-induced ISRs were abolished by Y-27632, an inhibitor of Rho-associated protein kinase (ROCK). These findings suggest that LPA-induced ISRs are attributable to histamine- and substance-P-mediated pathways. Moreover, the Rho/ROCK-mediated pathway may be involved.

Amides↗

PubMed2005

Scratching below the surface: wound healing and alanine mutagenesis provide unique insights into interactions between eristostatin, platelets and melanoma cells.

To study the molecular mechanism of the disintegrin eristostatin, cellular functional studies were performed using ten recombinant alanine mutants. ADP-induced platelet aggregation revealed critical contributions of seven residues within the 'RGD loop' (R24, R27, G28, N31) and C-terminus (W47, N48, G49) of this disintegrin. Using an in vitro scratch wound healing assay, four human melanoma cell lines yielded similar results when exposed to wildtype eristostatin. All eristostatin-treated cells healed less of the wounded area than control conditions. This phenomenon was reproduced when using fibronectin as the matrix. C8161 cells showed significant delay in wound closure with the N-terminal mutant P4A but not with R24A or G28A. Evidence from our laboratory and others suggests neither alpha IIb, alpha 4 nor alpha 5 integrins are directly involved in eristostatin's interactions. Eristostatin did not affect the number of melanoma cells in culture after 24 h or the development of apoptosis. However, phosphorylation studies performed after these melanoma cells were exposed to eristostatin revealed changes in several tyrosine phosphorylated molecules.

Alanine↗

PubMedDate not supplied

Scratch cytologic findings on surgically resected solitary fibrous tumors of the pleura.

OBJECTIVE: To ascertain the cytologic characteristics of solitary fibrous tumors of the pleura (SFTPs) on smear preparations. STUDY DESIGN: Fine needle aspiration cytology (FNAC) was initially attempted preoperatively in five cases, but the specimens were inappropriate for interpretation because only a few tumor cells were obtained. Therefore, scratch smears made at the time of operation were used. Papanicolaou and immunocytochemical staining was performed in all 10 cases, 2 of which were malignant. RESULTS: As expected, cellular tumors yielded more cells. The cytologic appearance was variable, showing spindle/bipolar, dendritic/stellate and intermediate cells. Atypical cells reminiscent of sarcoma were also present in cellular, benign tumors. Highly atypical epithelioid cells were obtained in two malignant cases. Immunocytochemically, the tumor cells were positive for CD34 and vimentin and negative for cytokeratin, regardless of histologic differences and cell shape. CONCLUSION: It seems difficult to diagnose SFTPs with certainty by FNAC, partly because the cell morphology of SFTPs resembles a wide variety of heterogeneous groups of spindle cell tumors and partly because only a few tumor cells were available in the FNAC specimens in the present study. However, a cytologic diagnosis of SFTP is possible if cytologic preparations yield CD34-positive cells with spindle/bipolar or dendritic/stellate morphology.

Adult↗

PubMed1995

Specificity of CNS and PNS regulatory subelements comprising pan-neural enhancers of the deadpan and scratch genes is achieved by repression.

The Drosophila pan-neural genes deadpan (dpn) and scratch (scrt) are expressed in most or all developing neural precursor cells of the central nervous system (CNS) and peripheral nervous system (PNS). We have identified a cis-acting enhancer element driving full pan-neural expression of the dpn gene which is composed of independent CNS- and PNS-specific subelements. We have also identified CNS- and PNS-specific subelements of the scrt enhancer. Deletion analysis of the dpn and scrt PNS-specific subelements reveals that PNS specificity of these two evolutionarily unrelated enhancers is achieved in part by repression of CNS expression. We discuss the implications of the striking organizational similarities of the dpn, scrt, and sna pan-neural enhancers.

Animals↗

PubMed1990

Histological observations of canine cystic endometrial hyperplasia induced by intrauterine scratching.

Of eight mongrel bitches, the antimesometrial side of the nonpregnant left horn of the uterus at the pregnant or nonpregnant luteal phase was scratched with a Kirschner's wire. Cystic endometrial hyperplasia (CEH) was induced in seven of the eight bitches (87.5%). No difference in the incidence of CEH in the left horn was seen between the pregnant and the nonpregnant groups. Histological examinations showed CEH with a dilatation of the basal glands, resembling "Swiss cheese endometrium".

Animals↗

PubMed2006

Insect bite-induced hypersensitivity and the SCRATCH principles: a new approach to papular urticaria.

Insect bites and the associated hypersensitivity reactions known as papular urticaria account for a significant number of all referrals from pediatricians and dermatologists to our pediatric dermatology clinic. Unfortunately, children affected by these eruptions are frequently misdiagnosed and often subject to expensive evaluations including invasive and unnecessary procedures. Here we review the course of 4 children with the typical physical findings and natural history of these reactions. On the basis of our clinical findings and experience with this patient population, we propose a set of principles (termed "SCRATCH") as clinical features to aid clinicians in making an early and accurate clinical diagnosis. We conclude that a more appropriate term for future study and diagnosis of this entity is insect bite-induced hypersensitivity.

Child, Preschool↗

PubMedDate not supplied

The effect of vitamin E on cellulitis in broiler chickens experiencing scratches in a challenge model.

Two experiments are described; each experiment contained five treatments with each treatment consisting of a specific diet and vitamin E at 8.82 mg, 41.89 mg, 74.96 mg, 108.03 mg, or 141.10 mg vitamin E per kilogram of feed. Birds were raised with continuous feed containing the various levels of vitamin E available throughout the experiment. At 4 wk of age, the birds were scratched on the breast and placed onto avian cellulitis Escherichia coli-seeded litter. One week later, the birds were euthanatized and lesion presence was noted. There appeared to be a positive correlation between vitamin E and the inhibition of cellulitis formation when the birds were fed a diet containing 74.96 mg vitamin E/kg feed. Conflicting results were seen in the two experiments when the birds were fed 41.89 and 108.03 mg vitamin E/kg feed. Both experiments had a high incidence of cellulitis in birds whose diets consisted of 141.10 mg vitamin E/kg feed.

Animals↗