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1.
The purpose of this study was to show that the occurrence of skin ulcers observed in animals neonatally treated with the neurotoxin capsaicin coincide with trophic disturbances. In addition, cutaneous lesions increased when self-grooming and scratching behaviors reached maturity. The temporal course of cephalic cutaneous wounds in neonatally capsaicin-treated rats was evaluated in animals wearing and not wearing plastic collars from postnatal day (P) 21 until P45. The collars were used to prevent self-grooming and scratching. Beginning on P21, capsaicin-treated rats under both conditions showed transient skin ulcers distributed throughout the head and neck regions. In the capsaicin-treated group without collars, lesions reached their greatest severity by P40, when self-grooming and scratching behaviors obtained adult characteristics. Furthermore, no lesions were detected after 25 days. In the capsaicin-treated rats that wore plastic collars, the widest distribution of skin lesions occurred on P55, after which time lesions vanished detection by 25 days. In this latter group, the cutaneous lesions were exacerbated when collars were removed. Data suggest that transient cutaneous wounds associated with neonatal capsaicin administration may be mediated via capsaicin-sensitive sensory neurons that are involved in trophic and regenerating neural mechanisms.  相似文献   

2.
BACKGROUND: Laser hair removal is rapidly becoming a widely used modality. Clinical studies are needed to assess these hair removal systems. The long-pulsed ruby laser is one such modality for the removal of unwanted hair. OBJECTIVES: To evaluate the efficacy of the long-pulsed ruby laser (694 nm, 3-msec pulsewidth, 7- or 10-mm spot size) in removing unwanted hair, and to provide treatment guidelines for the proper utilization of this laser system. METHODS: Forty-eight areas of unwanted facial and body hair from 25 patients with blonde, brown, or black hair were treated with the long-pulsed ruby laser at fluences between 10 and 40 J/cm2. Hair regrowth was measured at 4 weeks after the first treatment, 4 weeks after the second treatment, 4 weeks after the third treatment, and 16 weeks after the third treatment by counting the number of terminal hairs compared with baseline pretreatment values. All complications and treatment outcomes were documented. RESULTS: The mean percent of regrowth after the first treatment was 65.5%, 41% after the second treatment, and 34% after the third treatment. Overall, regardless of skin type or targeted body region, patients who underwent three treatment sessions demonstrated an average 35% regrowth in terminal hair count compared with baseline pretreatment values 6 months after initial therapy. CONCLUSION: Long-pulsed ruby laser treatment resulted in significant hair growth delay in most cases. Repeated laser treatments produced an increased number of vellus hairs, an increase in growth delay, and a decreased percentage of hair regrowth.  相似文献   

3.
Hair     
The psychologic importance of hair to man is in inverse ratio to its physical function. Except for scalp hair and desultory areas of sexual hair, most of man's hair follicles are vestigial. Three problems of hair growth remain to be solved: (1) how the intermittent activity of hair follicles in both animals and man is controlled; (2) how the male hormone alters the hair cycle in human skin; and (3) why larger hairs are produced by testosterone in some areas of the body when in some individuals the hair follicles in the scalp regress. Studies in which skin grafts from rats of different ages were exchanged showed that hair follicles are innately programmed but can be slowly influenced by systemic factors. Steroid hormones, especially estrogens, slow down the moult cycle whereas thyroid hormones accelerate it. What establishes the innate rhythm remains problematical. The fact that plucking out the club hair initiates activity in resting follicles has been explained by the hypothesis that the mitotic inhibitor which accumulates during anagen is normally used up or dispersed during telogen or by wounding. However, contrary to this theory, follicular activity is not prolonged by epilation during anagen. Moreover, if rats are epilated within one or two days of eruption, only club hairs are removed since forceps cannot grasp the tips of the new hairs. Such epilation does not affect the anagen in progress, but remarkedly enough the subsequent resting phase is shortened. Both sexual hair and male-pattern baldness depend on androgenic hormones. Target organs of testosterone convert the hormone to active metabolites, chiefly 5alpha-dihydrotestosterone. In skin, however, 5alpha-dihydrotestosterone may not be the only active tissue androgen. The major metabolite of testosterone incubated with hair roots in androstenedione, and hirsute women without other obvious endocrine abnormality sometimes excrete high levels of androstanediol. Both steroids stimulated the sebaceous glands of hypophysectomized-castrated rats, which, however, showed only a limited response to testosterone. The androgenic steroids, the enzymes that convert them to their active metabolites, and the proteins that bind them are undoubtedly very important to the problems of the growth of sexual hair and male-pattern baldness.  相似文献   

4.
Hair transfer from split-thickness skin grafts harvested from the scalp is not a widely reported problem. The authors present their experience with hair transfer from scalp autografts in a pediatric burn population, with particular emphasis on hair transfer to the face. They retrospectively reviewed 3307 acute and reconstructive pediatric burn admissions over a 4-year period at a single institution and identified 109 cases in which the scalp had been used as a donor site and in which the patient survived the acute burn period. Data from 73 male and 36 female patients were analyzed with respect to age, race, sex, percent total body surface area burned, graft thickness, number of scalp harvests and time between harvests, and presence of donor site alopecia. Eighteen of the 109 patients had noticeable hair growth from their scalp grafts (17 percent). Fourteen of 18 cases of hair growth involved face or neck grafts (13 percent); the remaining 4 patients had hair growth elsewhere on the body. There was no difference between the two groups (hair growth versus no hair growth) when compared by age, sex, or graft thickness. There was a correlation between larger burn size and greater incidence of hair growth. Those who had multiple harvests of the same scalp donor site were more than twice as likely to have hair transfer (9 of 34 versus 9 of 75 patients), although time between harvests was not a significant variable. Caucasian children represented 77 percent of the study population yet 100 percent of the cases of problem hair growth. Thirty-three percent of the hair growth group (6 of 18 patients) and 4 percent of the remaining patients (4 of 91) had some degree of donor site alopecia. The scalp is a reliable and valuable donor site for skin grafting in children, particularly for facial burns. The authors note a moderate incidence of hair transfer (17 percent) and propose both suggestions for prevention and recommendations for management.  相似文献   

5.
In a recent scalp avulsion injury, the scalp should always be re-implanted without delay if at all available. Subsequent normal hair growth can hardly be expected, but at least an original skin replacement has been effected. The reconstruction of only a part of the scalp should be performed in such a way that the hairless area is situated in the centre. The surrounding hair will cover this centre part. Rotation flaps in the region of the scalp follow other rules than apply to all other areas of the body. If applied correctly, good results can be achieved because of the excellent blood supply.  相似文献   

6.
Many doctors frequently encounter hirsute patients. Quantification of hair growth may be useful for diagnosis and follow-up. To establish the reference range for distribution and density of hair in females, and to determine the regions yielding the best discrimination between normal and hirsute women, we studied the distribution and density of terminal hair on 12 body regions assessed on a scale of 0-4. Prospectively, 81 healthy female volunteers and 71 hirsute patients of child-bearing age and Dutch ancestry, who were not receiving medication, and who had not had a recent pregnancy were studied. The reference hair pattern was established for each body region, and the threshold value yielding the highest sensitivity and specificity to evaluate hirsutism was calculated. None of the women in the reference population displayed a score of more than 1 for chin, upper back, upper abdomen and upper arm, or more than 2 for upper lip, side-burns, chest, lower back, lower abdomen, thighs or forearm. The best discrimination between the reference and hirsute populations was obtained with the sum of the scores for four regions: upper lip, chin, lower abdomen and thighs. Independent assessment of hair growth by two investigators revealed excellent agreement. We conclude that a score of more than 1 for chin, upper back, upper abdomen and upper arm, or more than 2 for upper lip, side-burns, chest, lower back, lower abdomen, thighs or forearm is abnormal for Dutch women, and that assessment of hair growth on the upper lip, chin, lower abdomen and thighs is the most suitable way to evaluate hirsutism.  相似文献   

7.
8.
Hair growth disorders, particularly those that lead to hair loss (alopecia), are common and frequently cause significant mental anguish in affected individuals. The mechanisms underlying the majority of these disorders are unknown. However, insights into the specific molecular mechanisms of hair follicle development and cycling have recently been made using animal models, particularly mice that over- or underexpress a specific gene for a growth factor or cytokine. Other animal models have demonstrated that certain growth factors and cytokines can prevent much of the alopecia caused by cancer chemotherapeutic agents. These animal models have confirmed the importance of growth factors and cytokines in hair follicle development and cycling, and have formed the foundation for potential clinical therapy of hair growth disorders, particularly alopecia. Nevertheless, important questions concerning their efficacy, safety and delivery will need to be answered before successful clinical therapy of any hair growth disorder becomes a reality.  相似文献   

9.
Tested Sprague-Dawley male and female albino rats for intraspecies aggression without the use of shock. In the 1st experiment, 6 male pairs showed more biting attacks, offensive sideways movements, and self-grooming than did 6 female pairs; male pairs also showed more stereotyped defensive/submissive behaviors and were wounded more frequently. The 2nd experiment with 103 Ss examined the effects of neonatal castration and testosterone propionate (TP) on fighting. Males castrated at birth attacked other males less frequently than did controls when tested with TP treatment as adults. The TP given at birth to neonatally castrated males restored attacks to control levels. Females given TP as neonates did not differ from either male or female controls. Other aggressive/defensive behaviors, however, did not show this pattern. Results suggest that while the presence of testosterone during a brief postnatal period and during adulthood is necessary for attack behavior to occur, other related behaviors may not be affected in a similar manner. (11/2 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

10.
Hair follicle development, growth (anagen), and regression (catagen) largely result from bidirectional epithelial-mesenchymal interactions whose molecular basis is still unclear. Because adhesion molecules are critically involved in pattern formation and because the fundamental importance of neural cell adhesion molecule (NCAM) for feather development has been demonstrated, we studied the protein expression patterns of NCAM during hair follicle development and regression in the C57BL/6 mouse model. During murine hair follicle development, NCAM immunoreactivity (IR) was first detected on epithelial hair placodes and later on selected keratinocytes in the distal outer root sheath. Mesenchymal NCAM immunoreactivity (IR) was noted on fibroblasts of the future dermal papilla (DP) and the perifollicular connective tissue sheath. Fetal hair follicle elongation coincided with strong, ubiquitous dermal NCAM IR, which remained strong until the follicles entered into their first neonatal catagen. At this time, the strong interfollicular dermal NCAM IR decreased substantially. During consecutive hair cycles, mesenchymal NCAM IR was seen exclusively on DP and perifollicular connective tissue sheath fibroblasts and on the trailing cells of regressing catagen hair follicles. These highly restricted and developmentally controlled expression patterns suggest an important role for NCAM in hair follicle topobiology during morphogenesis and cyclic remodeling of this miniorgan.  相似文献   

11.
Hair cells in the bullfrog vestibular otolith organs were immunolabeled by monoclonal and polyclonal antisera against calbindin (CaB), calmodulin (CaM), calretinin (CaR), and parvalbumin (PA). S-100, previously shown to immunolabel striolar hair cells in fish vestibular organs, only weakly immunolabeled hair cells in the bullfrog vestibular otolith organs. Immunolabeling was not detected in supporting cells. With the exception of CaR, myelinated axons and unmyelinated nerve terminals were immunolabeled by all of the above antisera. Immunolabeling was seen in all saccular hair cells, although hair cells at the macular margins were immunolabeled more intensely for CaB, CaM, and PA than more centrally located hair cells. As the macula margins are known to be a growth zone, this labeling pattern suggests that marginal hair cells up-regulate their calcium-binding proteins during hair cell development. In the utriculus, immunolabeling for CaM and PA was generally restricted to striolar hair cells. CaR immunolabeling was restricted to the stereociliary array. Immunolabeling for other calcium-binding proteins was generally seen in both the cell body and hair bundles of hair cells, although this labeling was often localized to the stereociliary array and the apical portion of the cell body. CaM and PA immunolabeling in the stereociliary array in saccular and utricular striolar cells suggests a functional role for these proteins in mechanoelectric transduction and adaptation.  相似文献   

12.
A study was conducted with neonatal boars to measure age-related changes in functioning of the pituitary-adrenocortical axis. Pigs were randomly assigned to control (n = 7-10/age) or treated (1-min restraint, n = 9-11/age) groups to be sampled at either 12, 19, or 26 days of age. Blood samples were taken via catheter 10 min before and 3, 10, and 20 min after restraint or at similar time intervals in controls. One day later, pigs were killed and adrenal glands obtained for ACTH receptor measurements. Basal plasma ACTH concentrations were greatest (p = 0.035) on day 12 when compared with later ages, but basal plasma cortisol concentrations were comparable at the three ages. Compared with controls, restraint elevated incremental plasma ACTH and cortisol responses at each age (p < 0.004). On day 12, maximal plasma ACTH (p = 0.0006) and incremental cortisol (p < 0.006) responses to restraint were greater than at later ages. Binding to adrenal ACTH receptors was greatest (p < 0.05) at day 13, which may help explain the apparently increased in vivo response of the adrenal gland to ACTH at this time. Restrained pigs had increased growth rates with increasing age (p = 0.016) whereas growth rates for control pigs did not differ with age. At day 27, 24 h after the 1-min restraint, body weights of restrained pigs exceeded those of control pigs (p = 0.045). At day 20, adrenal DNA and protein in pigs restrained 24 h previously were greater than in control pigs (p < 0.05). These data suggest age-related changes in functioning of the pituitary-adrenal axis in neonatal boars, and an absence of period during neonatal life when the porcine pituitary adrenocortical axis cannot respond to a stressor. The data also indicate both rapid and long-term responses of the adrenal to a very modest stressor and suggest an extreme sensitivity of neonatal pigs to environmental perturbations.  相似文献   

13.
This study was designed to evaluate the effect of selective photothermolysis on dark pigmented hair follicles treated with a normal-mode ruby laser (694-nm wavelength, pulse duration 0.5 ms, fluence 20 J/cm2, spot size 2 mm). In 15 volunteers, four test areas each were selected. After shaving, the first area was irradiated once, the second twice, the third three times and the fourth served as control area. A punch biopsy was taken from each volunteer immediately after the first laser treatment. Four weeks after the last irradiation, no effect was found in six cases and little effect in another six cases (50-90% regrowth). Hair regrowth of less than 30% was observed in only three cases. Eight weeks after the last session, no effect was found in 11 cases, little effect in 2 cases (10%) and less than 30% regrowth in only 2 cases. Twelve weeks after the last treatment, no difference could be detected between the areas untreated and treated by laser. The laser parameters applied in this study do not result in effective epilation of body hair. In some cases, a delay in growth of several weeks was noticed.  相似文献   

14.
BACKGROUND: The final target cell response to estrogen is dependent not only on the estrogen receptor, but also on autocrine/paracrine interactions with growth factors (e.g., EGF) and proto-oncogenes (e.g., c-fos). Because neonatal estrogen treatment results in permanent changes in the female mouse genital tract (permanent vaginal cornification, cervical adenosis and tumors, changed growth control mechanisms in uterus), it was of interest to study possible acute and permanent effects of such treatment on distribution and levels of EGF, its receptor (EGF-r), and c-fos and to relate such changes to morphological development and appearance of epithelial abnormalities. METHODS: Immunohistochemical techniques using frozen sections from the uterus and vagina of neonatal and adult (ovariectomized, estradiol-treated) females, treated with olive oil or diethylstilbestrol in neonatal life. RESULTS: A difference in stromal-epithelial distribution of EGF was demonstrated with respect to region studied (uterus, vagina) and age (neonatal, adult). EGF was localized mainly in the uterine stroma but in both vaginal epithelium and stroma (with a different pattern compared to uterus). In neonatal females, EGF occurred in both tissue components in both regions, and the distribution pattern was quite different from that in adult females. The EGF level was increased by estrogen in adult but not in neonatal females. EGF-r and c-fos occurred in both uterine epithelium and stroma and in the vaginal epithelium; levels and distribution pattern were affected by estrogen. Neonatal estrogen treatment increased the levels of uterine EGF and c-fos in adult life. CONCLUSIONS: There are distinct developmental changes in the distribution and estrogen sensitivity of EGF. Only further studies can prove or disprove the association between the earlier reported disturbed growth control mechanisms in the uterus of adult but neonatally estrogen-treated females and the increased levels of uterine EGF and c-fos. The present results do not seem to explain mechanisms involved in the origin of neonatally estrogen-induced cervicovaginal epithelial abnormalities, nor do they explain the earlier described difference in estrogen-induced proliferative response between the uterine cervix and uterus proper.  相似文献   

15.
16.
17.
The yellow obese syndrome in mice encompasses many pleiotropic effects including yellow fur, maturity-onset obesity, hyperinsulinemia, insulin resistance, hyperglycemia, increased skeletal length and lean body mass, and increased susceptibility to neoplasia. The molecular basis of this syndrome is beginning to be unraveled and may have implications for human obesity and diabetes. Normally, the agouti gene is expressed during the hair-growth cycle in the neonatal skin where it functions as a paracrine regulator of pigmentation. The secreted agouti protein antagonizes the binding of the alpha-melanocyte-stimulating hormone to its receptor (melanocortin 1 receptor) on the surface of hair bulb melanocytes, causing alterations in intracellular cAMP levels. Widespread, ectopic expression of the mouse agouti gene is central to the yellow obese phenotype, as demonstrated by the molecular cloning of several dominant agouti mutations and the ubiquitous expression of the wild-type agouti gene in transgenic mice. Recent experiments have revealed that the hypothalamus and adipose tissue are biologically active target sites for agouti in the yellow obese mutant lines.  相似文献   

18.
19.
Growth components were compared in an experiment with a 2 x 2 factorial design. Eight replicates of Holstein heifers were fed diets based on either alfalfa or corn silage for daily gain of either 725 or 950 g from 181 to 334 kg of body weight (BW). Mean daily gains from corn diets were greater than gains from alfalfa diets for BW, udder, empty body, fat, fat-free matter, protein, H2O, C, and energy but were less than gains from alfalfa for gut contents and ash. High daily gain produced higher mean values for all of these variables than did lower daily gain. The percentage of protein in fat-free matter was not affected by either main effect. The percentage of fat in empty body gain was increased as daily gain increased. Energy concentration of fat-free matter that was gained was not affected by either diet or daily gain. Energy concentration of empty body gain increased as daily gain increased. The percentage of gut contents in daily BW gain was higher for heifers fed the alfalfa diet than for those fed the corn diet. Energy concentration in daily BW gain was affected by diet and daily gain. Variations of fat and gut contents in daily BW gain must be considered when requirements or expected growth are described.  相似文献   

20.
In a case of a sudden infant death syndrome-related death of a 3-month-old infant, nail clippings were positive for cocaine by gas chromatography-mass spectroscopy analysis that revealed a prenatal exposure to the drug substance. In utero exposure to drugs has been investigated using amniotic fluid, neonatal urine, meconium, and hair samples. Nail analysis offers some advantage over hair analysis because of its continuous growth and persistence after delivery. Nail material is easy to sample in suitable amounts. Currently, the cocaine finding cannot be related to the underlying cause of death. However, this observation indicates that nail analysis may be a new and valuable tool to screen newborns for intrauterine drug exposure. In addition, it can help collect information on the prevalence of possible embryotoxic effects and the link to postnatal manifestations of different dysfunctions in infants who are born by drug abusing mothers.  相似文献   

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