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1.
Ann Surg Oncol ; 26(10): 3166-3177, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31342392

RESUMO

BACKGROUND: Neoadjuvant chemotherapy (NACT) is often recommended for patients with node-positive invasive lobular carcinoma (ILC) despite unclear benefit in this largely hormone receptor-positive (HR+) group. We sought to compare overall survival (OS) between patients with node-positive ILC who received neoadjuvant endocrine therapy (NET) and those who received NACT. METHODS: Women with cT1-4c, cN1-3 HR+ ILC in the National Cancer Data Base (2004-2014) who underwent surgery following neoadjuvant therapy were identified. Kaplan-Meier curves and Cox proportional hazards modeling were used to estimate unadjusted and adjusted overall survival (OS), respectively. RESULTS: Of the 5942 patients in the cohort, 855 received NET and 5087 received NACT. NET recipients were older (70 vs. 54 years) and had more comorbidities (Charlson-Deyo score ≥ 1: 21.1% vs. 11.5%), lower cT classification (cT3-4: 44.2% vs. 51.0%), lower rates of mastectomy (72.5% vs. 82.2%), lower rates of pathologic complete response (0% vs. 2.5%), and lower rates of postlumpectomy (73.2% vs. 91.0%) and postmastectomy (60.0% vs. 80.8%) radiation versus NACT recipients (all p < 0.001). NACT recipients had higher unadjusted 10-year OS versus NET recipients (57.9% vs. 36.0%), but after adjustment, there was no significant difference in OS between the two groups (p = 0.10). CONCLUSIONS: Patients with node-positive ILC who received NET presented with smaller tumors, older age, and greater burden of comorbidities versus NACT recipients but had similar adjusted OS. While there is evidence from clinical trials supporting efficacy of NET in HR+ breast cancer, our findings suggest the need for further, histology-specific investigation regarding the optimal inclusion and sequence of endocrine therapy and chemotherapy in ILC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Carcinoma Lobular/tratamento farmacológico , Quimioterapia Adjuvante/mortalidade , Linfonodos/patologia , Terapia Neoadjuvante/mortalidade , Idoso , Neoplasias da Mama/patologia , Carcinoma Lobular/patologia , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Taxa de Sobrevida
2.
FASEB J ; 23(7): 2065-75, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19237503

RESUMO

Senile graying of human hair has been the subject of intense research since ancient times. Reactive oxygen species have been implicated in hair follicle melanocyte apoptosis and DNA damage. Here we show for the first time by FT-Raman spectroscopy in vivo that human gray/white scalp hair shafts accumulate hydrogen peroxide (H(2)O(2)) in millimolar concentrations. Moreover, we demonstrate almost absent catalase and methionine sulfoxide reductase A and B protein expression via immunofluorescence and Western blot in association with a functional loss of methionine sulfoxide (Met-S=O) repair in the entire gray hair follicle. Accordingly, Met-S=O formation of Met residues, including Met 374 in the active site of tyrosinase, the key enzyme in melanogenesis, limits enzyme functionality, as evidenced by FT-Raman spectroscopy, computer simulation, and enzyme kinetics, which leads to gradual loss of hair color. Notably, under in vitro conditions, Met oxidation can be prevented by L-methionine. In summary, our data feed the long-voiced, but insufficiently proven, concept of H(2)O(2)-induced oxidative damage in the entire human hair follicle, inclusive of the hair shaft, as a key element in senile hair graying, which does not exclusively affect follicle melanocytes. This new insight could open new strategies for intervention and reversal of the hair graying process.


Assuntos
Envelhecimento , Cor de Cabelo , Peróxido de Hidrogênio/metabolismo , Metionina/análogos & derivados , Estresse Oxidativo , Catalase/análise , Folículo Piloso/patologia , Humanos , Metionina/análise , Metionina/deficiência , Espécies Reativas de Oxigênio/metabolismo , Regeneração
3.
J Invest Dermatol ; 97(2): 345-8, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2071943

RESUMO

Androgens stimulate hair growth in some areas, e.g., beard, but may cause regression and baldness on the scalp. The mesenchyme-derived dermal papilla is believed to regulate many aspects of hair growth. It is probable that androgens exert their effect on hair growth via the dermal papilla. In this study the effect of androgens on the growth of cultured dermal papilla cells from beard and non-balding scalp was assessed. Dermal papilla cells from beard hair follicles and non-balding scalp were cultured in vitro in the presence and absence of different concentrations of testosterone or the synthetic, non-metabolizable androgen, mibolerone. Cell growth was reflected by the incorporation of 3H-thymidine. The presence of either androgen did not significantly alter DNA synthesis at any of the concentrations examined in either type of cell line. These results do not mean that dermal papilla cells do not respond to androgens in vitro, but that the measurement of cell growth is an inappropriate method of assessment. Androgens may well stimulate the synthesis of specific proteins that could influence the hair follicle.


Assuntos
Androgênios/farmacologia , Cabelo/efeitos dos fármacos , Pele/efeitos dos fármacos , Autorradiografia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , DNA/biossíntese , Feminino , Cabelo/citologia , Humanos , Masculino , Nandrolona/análogos & derivados , Nandrolona/farmacologia , Couro Cabeludo , Pele/citologia , Testosterona/farmacologia
4.
J Invest Dermatol ; 98(6 Suppl): 86S-91S, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1588130

RESUMO

Androgens are major regulators of human hair growth, but their effects vary: many follicles are stimulated by androgens, e.g., beard; some remain unaffected, e.g., eyelashes; whereas scalp follicles undergo regression and balding in genetically disposed individuals. Because the dermal papilla controls many aspects of the hair follicle, androgens may act via the dermal papilla, affecting the other follicular components indirectly. In this hypothesis androgens would alter dermal papilla cell production of regulatory substances, e.g., growth factors and/or extracellular matrix components. To test this theory the mechanism of androgen action has been compared in primary lines of dermal papilla cells cultured from androgen-dependent follicles and relatively androgen-independent non-balding scalp. Androgen receptor levels were assayed by saturation analysis (9-10 points; 0.05-10 nmol/l) using the synthetic androgen [3H]-mibolerone and specificity was confirmed by competition studies. Androgen metabolism was investigated both intracellularly and in the media after a 2-h incubation with 5 nM [3H]-testosterone. Carrier and [14C] steroids were added to the extracts before separation by thin-layer chromatography; steroid identity was confirmed by recrystallization. Dermal papilla cells from androgen-dependent follicles contained higher levels of specific, high-affinity, low-capacity androgen receptors than non-balding scalp cells. Testosterone metabolism also varied with beard, public and scalp cells containing testosterone and androstenedione intracellularly, but only beard cells producing 5 alpha-dihydrotestosterone, in line with the scanty beard growth found in 5 alpha-reductase deficiency. Elsewhere we have shown that cultured dermal papilla cells produce extracellular matrix components and mitogenic factors. These results all concur with our original hypothesis and suggest that further studies of such cells may elucidate the paradoxical effects of androgens on human hair follicles.


Assuntos
Androgênios/fisiologia , Cabelo/citologia , Cabelo/efeitos dos fármacos , Cabelo/crescimento & desenvolvimento , Humanos
5.
J Invest Dermatol ; 111(5): 727-32, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9804329

RESUMO

Androgens stimulate many hair follicles, e.g., beard, but may cause regression on the scalp; occipital areas are considered androgen independent. The mesenchyme-derived dermal papilla that regulates the hair follicle is considered the site of androgen action. Because hair size has been clearly related to dermal papilla size, one of the key functions androgens must regulate is the size of the dermal papilla. This implies that androgens stimulate dermal papilla cells to divide or to secrete autocrine mitogenic factors. As physiologic levels of androgens do not stimulate mitogenesis in cultured dermal papilla cells, this study was designed to determine whether dermal papilla cells cultured from human hair follicles with different responses to androgens in vivo, i.e., androgen-dependent beard and androgen-independent nonbalding scalp, produce soluble autocrine mitogenic factors and, if so, whether either cell type altered their secretion in response to testosterone in vitro. Conditioned medium was prepared by incubating individual primary lines of cells for 24 h with, and without, testosterone (10(-10)-10(-5) M). All conditioned media significantly increased [3H] thymidine incorporation by other dermal papilla cells; trypsin treatment significantly reduced the effect. Although both beard and scalp cell conditioned media had a similar stimulatory potential, beard cells incorporated approximately double the [3H]thymidine of scalp cells, in both types of media. Physiologic levels of testosterone increased mitogenic factor production by beard, but not scalp cells; only beard cells responded to these factor(s). Testosterone added after conditioning had no effect, indicating stimulation was not a synergistic effect of testosterone and conditioned medium. Thus, both beard and scalp cells release similar autocrine growth factor(s), but their response to these factor(s) is determined by their in vivo origin. Testosterone in vitro stimulates secretion of an autocrine growth factor(s) by beard, but not scalp cells, to which only beard cells are able to respond, reflecting the responses to androgens in vivo. These factors may be involved in the key increase of dermal papilla size necessary for androgen-induced changes in hair size.


Assuntos
Androgênios/farmacologia , Substâncias de Crescimento/metabolismo , Folículo Piloso/citologia , Couro Cabeludo/citologia , Testosterona/farmacologia , Adulto , Linhagem Celular , Meios de Cultura/química , Meios de Cultivo Condicionados/química , Relação Dose-Resposta a Droga , Feminino , Folículo Piloso/efeitos dos fármacos , Folículo Piloso/metabolismo , Humanos , Masculino , Mitógenos/metabolismo , Pele/citologia , Pele/metabolismo , Timidina/metabolismo , Trítio , Tripsina/farmacologia
6.
J Invest Dermatol ; 106(5): 1017-22, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8618032

RESUMO

Androgens regulate the growth of many human hair follicles, but only pubic, axillary, and scalp hair growth occur in men with 5 alpha-reductase deficiency. This suggests that 5 alpha-dihydrotestosterone is the active intracellular androgen in androgen-dependent follicles, except in the axilla and pubis. Since the dermal papilla plays a major regulatory role in hair follicles and may be the site of androgen action, we have investigated androgen metabolism in six primary lines of cultured dermal papilla cells from pubic and axillary hair follicles; previous studies have shown that beard cells take up and metabolize testosterone, retaining and secreting 5 alpha-dihydrotestosterone. After 24 h preincubation in serum-free Eagle's medium 199, 100-mm dishes of confluent cells were incubated for 2 h with 5 nM [1,2,6,7-3H]testosterone. Media were collected and the cells washed with phosphate-buffered saline and extracted with chloroform: methanol (2:1). After the addition of unlabeled and 14C-labeled marker steroids, the extracts were analyzed by a two-step thin-layer chromatography system; steroid identity was confirmed by recrystallization to a constant 3H/14C ratio. Beard and pubic dermal papilla cells were also incubated for 24 h, and the medium was analyzed at various times. The results from pubic and axillary primary cell lines were similar. In both cells and media the major steroid identified was testosterone, but significant amounts of androstenedione were present, indicating 17 beta-hydroxysteroid dehydrogenase activity; androstenedione was also identified within the cells, but a small amount of 5 alpha-dihydrotestosterone was only identified in one pubic cell line. Beard dermal papilla cells secreted large amounts of 5 alpha-dihydrotestosterone into the medium over 24 h in contrast to pubic cells, which produced only very small amounts. The pubic and axillary cell results contrasts with the observations of pronounced 5 alpha-dihydrotestosterone in beard cells and confirm that androgen metabolism in cultured dermal papilla cells reflects the parent follicle's ability to respond to androgen in the absence of 5 alpha-reductase type II in vivo. This supports our hypothesis that androgen acts on hair follicles via the dermal papilla and suggests that cultured dermal papilla cells may offer an important model system for studies of androgen action.


Assuntos
Folículo Piloso/metabolismo , Oxirredutases/deficiência , Testosterona/metabolismo , Células Cultivadas , Colestenona 5 alfa-Redutase , Folículo Piloso/citologia , Humanos , Masculino , Fatores de Tempo
7.
J Invest Dermatol ; 96(5): 673-81, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-1827135

RESUMO

The "active" edges of patches of alopecia areata and normal areas from the same scalp (i.e., bearing normal terminal hair) from seven patients with alopecia areata were investigated immunohistologically. Similar areas from a further eight patients were examined using light and electronmicroscopy. "Active" and "normal" areas of alopecia areata scalps were immunohistologically similar and varied from normal controls in the number, distribution, and ratio for T4 and T8-positive cells. Similarly the ultrastructural changes seen in the "active" areas when compared to normal controls were also present in the "normal" areas of alopecia areata scalps. The most significant differences found between normal "control" follicles and both "active" and "normal" areas of alopecia areata scalps were the polymorphic nature of the dermal papilla cells and the loss of cellular organization within the dermal papillae taken from alopecia areata scalps. In addition, the junction between the dermal papilla and the bulb of the hair follicle, the dermo-epithelial junction of the hair follicle bulb, demonstrated critical changes in follicles taken from both "active" and "normal" areas of alopecia areata scalps. These results support the suggestion of a subclinical state of alopecia areata and indicate that further work on the etiology of alopecia areata should be directed towards the "normal" areas of alopecia areata scalps, in particular the cells of the dermal papilla and the dermo-epithelial junction of the hair follicle bulb.


Assuntos
Alopecia em Áreas/patologia , Cabelo/patologia , Pele/patologia , Subpopulações de Linfócitos T , Adulto , Alopecia em Áreas/imunologia , Feminino , Cabelo/ultraestrutura , Humanos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Pele/ultraestrutura , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia
8.
J Invest Dermatol ; 101(1 Suppl): 114S-120S, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8326143

RESUMO

Many hair follicles produce different types of hair in response to environmental changes or the mammals age, that are translated to the follicle by hormones. Androgens cause many changes, such as transforming vellus follicles producing insignificant hairs on the face to terminal beard ones at puberty or the reverse on the scalp. In male red deer the breeding season rise in androgens causes the annual production of a mane on the neck that is lost during the spring. Because the dermal papilla situated at the base of the hair follicle is important in determining the type of hair produced, androgens may act via the dermal papilla. Therefore, primary cell lines of dermal papilla cells from human and red deer follicles with different responses to androgens have been established. Specific saturable androgen receptors were present in all human papilla cells examined, with higher levels in cells from androgen-dependent follicles, e.g., beard than in control, non-balding scalp cells. In preliminary investigations of red deer, androgen receptors were only present in cells derived from mane follicles and were undetectable in flank or spring neck follicles. These similar results from both species support the hypothesis that androgens are acting on hair follicles via the dermal papilla. They also suggest that dermal papilla cells are potentially useful models for investigating the mechanism of androgen action because cultured cells appear to retain differences that relate to the androgen responsiveness of their parent follicle. The red deer seems particularly interesting in view of the much shorter hair-growth cycle than human scalp or beard follicles.


Assuntos
Cervos/anatomia & histologia , Cabelo/crescimento & desenvolvimento , Receptores Androgênicos/análise , Pele/citologia , Adulto , Animais , Células Cultivadas/química , Criança , Pré-Escolar , Cabelo/química , Cabelo/ultraestrutura , Humanos , Masculino , Pele/química , Pele/ultraestrutura
9.
Am J Clin Nutr ; 20(5): 452-6, 1967 May.
Artigo em Inglês | MEDLINE | ID: mdl-6023855

RESUMO

PIP: This is an extension of work recently reported by Rose regarding young women using a combination of progesterone and estrogen for ovulation control. The 10 subjects studied had an abnormal xanthurenic acid excretion after a loading dose of tryptophan. After treatment with 2.5 mg norethynodrel and .1 mg mestranol (Enovid-E) from Days 5 to 24 of the the cycle, 24-hour urine specimens were collected before and after administration of 2 gm of L-tryptophan. They were then given 25 mg of pyridoxine hydrochloride 4 times a day during the 48 hours required to repeat the tryptophan loading test. Controls were 18 healthy women not taking drugs. Metabolites of trytophan determined were indican, anthranilic acid glucuronide, 0-aminohippuric acid, kynurenic acid, acetylkynurenine, kynurenine, 3-hydroxykynurenine, xanthurenic acid, and N-methyl-2-pyridone-5-carboxamide. Urine specimines were analyzed for these and for 4-pyridoxic acid taking usual precautions to avoid dietary factors or drugs which might vitiate the results. At first the ingestion of the steroid had no significant effect on the basal excretion of urinary tryptophan metabolites. However, after the loading dose of tryptophan, the subjects taking Enovid E- excreted a mean level of 697 micro-moles of xanthurenic acid compared with a mean level of 29.8 micro-moles in controls. Some of the other metabolites were also excreted in increased quantities: 3-hydroxykynurenine, kynurenine, kynurenic acid, and acetylkynurenine. The others were excreted in normal quantities. When experimental subjects were given 100 mg/day of supplemental pyridoxine hydrochloride, tryptophan metabolism was essentially normal. These results should be considered in human metabolic studies of pyridoxine-requiring enzyme systems.^ieng


Assuntos
Mestranol/metabolismo , Noretinodrel/metabolismo , Ovulação/efeitos dos fármacos , Piridoxina/metabolismo , Triptofano/metabolismo , Feminino , Humanos
10.
J Endocrinol ; 133(1): 141-7, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1517703

RESUMO

Androgens stimulate hair growth in many areas, e.g. the beard; they also induce regression and balding on the scalp with increasing age in genetically disposed individuals. The cause(s) of this biological conundrum is unknown but age-related; androgen-potentiated changes also occur in the prostate. The mesenchyme-derived dermal papilla situated at the base of the hair follicle is thought to play an important role in regulating the growth and development of the follicular epithelium. Since androgens probably act on the hair follicle via the dermal papilla, cultures of dermal papilla cells from human hair follicles with differing responses to androgens in vivo have been established and their ability to bind androgens assessed. Receptor binding was assayed by saturation analysis (0.05-10 nmol/l) using the synthetic non-metabolizable androgen, [3H]mibolerone. Shionogi 115 cells were also assayed as a positive control. Specific high-affinity low-capacity androgen receptors were identified in 12 dermal papilla primary cell lines with similar characteristics to established androgen receptors. Cells from androgen-sensitive follicles (beard, scrotum and pubis) contained higher levels of androgen receptors than those derived from relatively androgen-insensitive non-balding scalp follicles whether the receptor content was calculated in relation to cell number, protein or DNA content of the cells. These results support the hypothesis that androgens act on hair follicles via the dermal papilla in vivo and demonstrate that dermal papilla cells exhibit an altered phenotype in culture which depends on the body site from which they were derived.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Androgênios/fisiologia , Face , Cabelo/citologia , Receptores Androgênicos/metabolismo , Couro Cabeludo/metabolismo , Pele/metabolismo , Células Cultivadas , Humanos , Ensaio Radioligante , Couro Cabeludo/citologia , Sensibilidade e Especificidade , Pele/citologia , Distribuição Tecidual
11.
J Endocrinol ; 168(3): 401-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11241171

RESUMO

Red deer stags produce an androgen-dependent mane of long hairs only in the breeding season; in the non-breeding season, when circulating androgen levels are low, the neck hair resembles the rest of the coat. This study was designed to determine whether androgen receptors are present in deer follicles throughout the year or only in the mane (neck) follicles when circulating testosterone levels are high in the breeding season. Although androgens regulate much human hair growth the mechanisms are not well understood; they are believed to act on the hair follicle epithelium via the mesenchyme-derived dermal papilla. The location of androgen receptors in the follicle was investigated by immunohistochemistry and androgen binding was measured biochemically in cultured dermal papilla cells derived from mane and flank follicles during the breeding season and from neck follicles during the non-breeding season. Immunohistochemistry of frozen skin sections using a polyclonal antibody to the androgen receptor localised nuclear staining only in the dermal papilla cells of mane follicles. Saturation analysis assays of 14 primary dermal papilla cell lines using [(3)H]-mibolerone demonstrated high-affinity, low-capacity androgen receptors were present only in mane (breeding season neck) cells; competition studies with other steroids confirmed the specificity of the receptors. Androgen receptors were not detectable in cells from either the breeding season flank nor the non-breeding season neck follicles. The unusual biological model offered by red deer of androgen-dependent hair being produced on the neck in the breeding, but not the non-breeding season, has allowed confirmation that androgen receptors are required in follicle dermal papilla cells for an androgen response; this concurs with previous human studies. In addition, the absence of receptors in the non-breeding season follicles demonstrates that receptors are not expressed unless the follicle is responding to androgens. Androgen receptors may be induced in mane follicles by seasonal changes in circulating hormone(s).


Assuntos
Androgênios/fisiologia , Cervos/metabolismo , Folículo Piloso/metabolismo , Receptores Androgênicos/metabolismo , Estações do Ano , Animais , Ligação Competitiva , Técnicas de Cultura de Células , Folículo Piloso/citologia , Técnicas Imunoenzimáticas , Masculino , Pescoço , Reprodução/fisiologia
12.
Br J Radiol ; 67(802): 938-40, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8000835

RESUMO

This study compares the results of a computerized strain-gauge plethysmograph with ascending lower limb venography in 94 patients with clinical deep venous thrombosis, and in 121 patients with asymptomatic legs being screened after total hip replacement. In the symptomatic patients, strain-gauge plethysmography had a sensitivity of 100%, an accuracy of 73%, a specificity of 64% and a negative predictive value of 100% for thrombosis above the popliteal confluence. In the screened patients, the figures were 38.1%, 55.4%, 60.0% and 81.1% respectively. Computerized strain-gauge plethysmography is a safe, non-invasive, reliable and portable method of excluding proximal thrombosis in a symptomatic patient. It avoids the need for urgent venography when anticoagulation therapy is reserved for those with proximal thrombosis. The device was not valuable as a screening tool after total hip replacement, since it had a low specificity and did not reliably detect the non-occlusive mural femoral thrombi which typically follow this procedure.


Assuntos
Microcomputadores , Pletismografia/instrumentação , Tromboflebite/diagnóstico , Diagnóstico por Computador , Articulação do Quadril/cirurgia , Prótese de Quadril , Humanos , Flebografia , Cuidados Pós-Operatórios/instrumentação , Valor Preditivo dos Testes , Sensibilidade e Especificidade
13.
Eur J Dermatol ; 11(4): 315-20, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11399537

RESUMO

Androgens regulate many aspects of human hair growth in both sexes. After puberty they transform tiny vellus follicles in many areas, e.g. the face, to terminal ones producing long, thick, pigmented hairs. In genetically predisposed individuals, androgens also cause the reverse transformation of terminal scalp follicles into vellus ones, causing balding. In the current hypothesis for androgen action, androgens control most follicular cells indirectly acting via the mesenchyme-derived dermal papilla which regulates many aspects of follicular activity. In this model androgens binding to androgen receptors in dermal papilla cells alter their production of regulatory molecules which influence other follicular components; these molecules may be soluble paracrine factors and/or extracellular matrix proteins. This hypothesis is supported by immunohistochemical localisation of androgen receptors in dermal papilla cell nuclei and the demonstrations that androgen receptor content and testosterone metabolism patterns of cultured dermal papilla cells from various body sites reflect hair growth in androgen-insensitivity syndromes. The next question is whether androgens alter the paracrine factors secreted by dermal papilla cells. Cultured dermal papilla cells do release soluble, proteinaceous factors into their media which stimulate the growth of keratinocytes and other dermal papilla cells. This mitogenic potential can cross species from humans to rodents. Importantly, testosterone in vitro stimulates the mitogenic potential of beard cells, but in contrast inhibits production by balding scalp cells reflecting their in vivo androgenic responses. Since androgens in vitro do alter the secretion of paracrine factors the current focus lies in identifying specific factors produced, e.g. IGF-I and stem cell factor (SCF), using ELISA and RT-PCR, and comparing their expression in cells from follicles with varying responses to androgens in vivo or under androgen stimulation in vitro. This should lead to greater understanding of androgen action and enable the development of better treatment for androgen-potentiated disorders.


Assuntos
Androgênios , Cabelo/crescimento & desenvolvimento , Comunicação Parácrina , Pele/citologia , Humanos
14.
Clin Biomech (Bristol, Avon) ; 13(6): 452-4, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11415821

RESUMO

OBJECTIVE: To assess the accuracy of the Kinemetrix motion analysis system to measure horizontal movement by a single reflective marker away from two cameras with differing camera placements. DESIGN: Trial of the effects of nine different camera arrangements on precision of non-human movement. BACKGROUND: In many cases the ability to arrange cameras to allow a separation of 60 degrees is not possible. Little is known about the precision of motion analysis systems for small camera angle separations. METHODS: The accuracy of the Kinemetrix system was assessed with camera horizontal separations of 15 degrees, 30 degrees and 45 degrees, and vertical separations of 0 degrees, 15 degrees and 30 degrees rendering nine different camera placements. The distance between the cameras and the object was always maintained at 4 m. During each test the marker was moved a known horizontal distance along a line bisecting the horizontal angular separation of the two cameras. The mean absolute errors of the Kinemetrix measurement were calculated. RESULTS: At the smallest camera separation tested (15 degrees horizontal, 0 degrees vertical), the Kinemetrix was unable to calculate the three-dimensional co-ordinate of the marker. For all other camera positions tested, the errors in measurements were small (mean absolute errors < 2 mm). CONCLUSIONS: Maintaining camera horizontal and vertical separations above a sum of 30 degrees is sufficient for clinical testing. RELEVANCE: Motion analysis systems are becoming more common for clinical evaluation where only confined testing areas are available. These confined areas often make positioning of cameras at greater than 60 degrees impossible; therefore, there is a need to explore the errors involved in placing two cameras at less than 60 degrees.

20.
J Biomater Sci Polym Ed ; 19(8): 1097-109, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18644234

RESUMO

Estrogen plays an important role in skin homeostasis, as demonstrated by the changes seen in the skin of post-menopausal women, changes reversed by HRT. Estrogen also has a role in wound healing, since estrogen deficiency as occurs post-menopausally and in ovariectomised animals, is associated with a reduced rate of wound healing. Estrogen appears to modulate all phases of wound healing with effects on inflammatory cells, epithelialization, angiogenesis, extracellular matrix deposition and tissue remodelling. This study was designed to investigate the effects of 17beta-estradiol on cultured human dermal fibroblasts using an in vitro wound-healing assay. The end points investigated were cell migration, proliferation, total collagen secretion and active TGF-beta1 secretion. 17beta-estradiol significantly increased the migration and proliferation of cultured dermal fibroblasts following mechanical wounding, although the secretion of total soluble collagen was not altered. An increase in TGF-beta1 was demonstrated by unwounded confluent dermal fibroblast monolayers in response to 17beta-estradiol, but paradoxically, a decrease in the secretion of TGF-beta1 was demonstrated in the mechanically wounded dermal fibroblasts. These results identify human dermal fibroblasts as estrogen target cells and provide further evidence for a role by which estrogen regulates this particular cell type as part of the wound-healing process. However, the paradoxical nature of the effect of estrogen on TGF-beta1 secretion following mechanical wounding suggests that the cellular mechanism of action is complex. A greater understanding of the cell-specific action of estrogen may help to develop therapies that will improve cutaneous wound healing in the future.


Assuntos
Derme/citologia , Estradiol/fisiologia , Fibroblastos/citologia , Fator de Crescimento Transformador beta/metabolismo , Materiais Biocompatíveis , Movimento Celular , Proliferação de Células , Células Cultivadas , Colágeno/metabolismo , Estrogênios/metabolismo , Fibroblastos/metabolismo , Humanos , Mitomicina/farmacologia , Pele/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Cicatrização
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