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Gland Function (gland + function)
Kinds of Gland Function Selected AbstractsEtiology of cicatricial alopecias: a basic science point of viewDERMATOLOGIC THERAPY, Issue 4 2008Kevin J. McElwee ABSTRACT: This article presents a short summary of our current knowledge of cicatricial alopecia disease pathogenesis and the hypothetical disease mechanisms that may be involved in scarring alopecia development. Several forms of scarring alopecia likely involve targeted cytotoxic action against hair follicle cells mediated by a folliculocentric inflammation. However, the specific nature of the inflammatory interference in hair follicle growth is open to question. A popular hypothesis of lymphocyte-mediated scarring alopecia development involves autoimmune targeting of hair follicle,specific self-antigens, although there is no direct evidence in support of such a view. Alternative hypotheses focus on defects in sebaceous gland function, destruction of hair follicle stem cells, and interference in the communication between hair follicle mesenchyme and epithelium. Many questions arise from these hypotheses, and addressing them with a systematic research approach may enable significant advances in understanding cicatricial alopecia etiology. [source] Thyroid hormone responses to endurance exerciseEQUINE VETERINARY JOURNAL, Issue S36 2006E. A. GRAVES Summary Reasons for performing study: Limited information exists about changes in circulating thyroid hormone concentrations during prolonged endurance exercise in horses. Objective: To examine the effects of prolonged exercise on serum iodothyronine concentrations in horses performing endurance exercise of varying distances. Methods: Serum concentrations of iodothyronines were measured in horses before and after completion of 40, 56, 80 and 160 km endurance rides (Study 1); daily during a 5 day, 424 km endurance ride (Study 2); and before and for 72 h after completion of a treadmill exercise test simulating a 60 km endurance ride (Study 3). Results: In Study 1, 40 and 56 km of endurance exercise had little effect on serum iodothyronine concentrations with the exception of a 10% decrease (P<0.05) in free thyroxine (FT4) concentration after the 56 km ride. In contrast, total thyroxine (T4), total triiodothyronine (T3), FT4 and free triiodothyronine (FT3) concentrations all decreased (P<0.05) after successful completion of 80 and 160 km rides, with decreases ranging from 13,31% and 47,54% for distances of 80 and 160 km, respectively. Further, pre-ride T4 concentration was lower (P<0.05) and FT3 concentration was higher (P<0.05) in horses competing 160 km as compared to horses competing over shorter distances. In Study 2, serum concentrations of T4, T3 and reverse triiodothyronine (rT3) progressively decreased (P<0.05) over the course of the multi-day ride. In Study 3, the greatest decrease (P<0.05) in all iodothyronines was observed at 12 h of recovery, ranging from 25% for FT4 to 53% for FT3, but all thyroid hormone concentrations had returned to the pre-exercise values by 24 h of recovery. Conclusion: Endurance exercise results in transient decreases in serum iodothyronine concentrations. Potential relevance: These data are important to consider when thyroid gland function is assessed by measurement of serum iodothyronine concentrations in endurance horses. [source] Salivary gland parameters and clinical data related to the underlying disorder in patients with persisting xerostomiaEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2007Ianthe Van Den Berg This study assessed salivary gland parameters and clinical data in patients referred to our clinic because of persisting xerostomia of unknown origin, in order to facilitate early diagnosis and recognition of the underlying disorder. Most patients were referred for diagnostic analysis of a possible Sjögren's syndrome (SS). A complete diagnostic work-up was available in all patients (n = 176), including data on salivary gland function, saliva composition, sialography, salivary gland swelling, pattern of complaints, general health, and medication. Patients were diagnosed with SS (n = 62), sialosis (n = 45), sodium retention syndrome (n = 30), or medication-induced xerostomia (n = 9). In 30 patients no disease related to salivary gland pathology was found. Unstimulated whole salivary flow was decreased in all patients, except in patients with sodium retention syndrome and in patients without salivary gland pathology. Submandibular/sublingual salivary flow was lowest in SS patients. SS and sialosis patients had increased salivary potassium concentrations, whereas only SS patients had increased sodium concentrations. About half of the sialosis patients mainly complained of persistent parotid gland swelling. Xerostomia-inducing medication was used by most patients. It was concluded that gland-specific sialometry and sialochemistry is useful in discriminating between the various disorders causing persisting xerostomia. [source] Salivary gland function in persons with ectodermal dysplasiasEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2003Hilde Nordgarden Ectodermal dysplasias (EDs) constitute a group of conditions comprising developmental defects in two or more of the following tissues: hair, teeth, nails, and sweat glands. The aim of the present study was to contribute to a better understanding of salivary gland involvement in EDs. An ED group (n = 39, median age 12 yr; 24 males, 15 females) and a healthy age- and sex-matched control group were studied. Citric acid stimulated submandibular and parotid salivary flow rates and salivary concentrations, and output of total protein, acidic proline-rich proteins and histatins were analysed. The associations between quantitative and qualitative salivary parameters were also studied. In the ED group, 13 persons (33%) demonstrated a significantly reduced secretion of submandibular and/or parotid saliva, in addition to a low unstimulated and/or chewing-stimulated whole salivary flow. In the ED group as a whole, a reduced median secretory rate of submandibular saliva was found, whereas the median concentrations of some protein parameters were increased. However, the overall output of proteins was normal or reduced. Submandibular glands seemed to be more affected than parotid glands in EDs. In conclusion, salivary secretory tests are recommended in persons with known or suspected EDs. [source] Evaluation of patterns of failure and subjective salivary function in patients treated with intensity modulated radiotherapy for head and neck squamous cell carcinomaHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 3 2007Megan E. Daly BS Abstract Background. Our aim was to correlate patterns of failure with target volume delineations in patients with head and neck squamous cell carcinoma (HNSCC) treated with intensity-modulated radiation therapy (IMRT) and to report subjective xerostomia outcomes after IMRT as compared with conventional radiation therapy (CRT). Methods. Between January 2000 and April 2005, 69 patients with newly diagnosed nonmetastatic HNSCC underwent curative parotid-sparing IMRT at Stanford University. Sites included were oropharynx (n = 39), oral cavity (n = 8), larynx (n = 8), hypopharynx (n = 8), and unknown primary (n = 6). Forty-six patients received definitive IMRT (66 Gy, 2.2 Gy/fraction), and 23 patients received postoperative IMRT (60.2 Gy, 2.15 Gy/fraction). Fifty-one patients also received concomitant chemotherapy. Posttreatment salivary gland function was evaluated by a validated xerostomia questionnaire in 29 IMRT and 75 matched CRT patients >6 months after completing radiation treatment. Results. At a median follow-up of 25 months for living patients (range, 10,60), 7 locoregional failures were observed, 5 in the gross target or high-risk postoperative volume, 1 in the clinical target volume, and 1 at the junction of the IMRT and supraclavicular fields. The 2-year Kaplan,Meier estimates for locoregional control and overall survival were 92% and 74% for definitive IMRT and 87% and 87% for postoperative IMRT patients, respectively. The mean total xerostomia questionnaire score was significantly better for IMRT than for CRT patients (p = .006). Conclusions. The predominant pattern of failure in IMRT-treated patients is in the gross tumor volume. Parotid sparing with IMRT resulted in less subjective xerostomia and may improve quality of life in irradiated HNSCC patients. © 2006 Wiley Periodicals, Inc. Head Neck, 2007 [source] Recovery of rat submandibular salivary gland function following removal of obstruction: a sialometrical and sialochemical studyINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 6 2006Samira M. Osailan Summary Functional recovery of the rat submandibular gland following ligation of the main excretory duct was examined. Rat submandibular glands were ligated for 1, 4 and 8 weeks using a micro-clip with a plastic tube. Micro-clips were removed and glands were allowed to recover for periods of 8, 16 and 24 weeks. Submandibular glands were stimulated with autonomimetic drugs (methacholine and isoprenaline) and salivas were collected from atrophic or de-ligated and contralateral control glands. Glands recovered almost full size (92% of control gland) following 24 weeks of de-ligation. Saliva volume secreted by ligated/de-ligated (RSM) and control (LSM) glands were similar with different doses of agonists. Protein output expressed per gram of tissue wet weight was similar from both ligated/de-ligated and control glands with all doses of agonist. Sodium and chloride levels were higher from de-ligated glands than contralateral control glands. Protein electrophoresis showed similar profiles of salivary proteins in all samples with some minor differences. Acinar cells in de-ligated glands showed a normal morphology, as indicated by light microscopy, whilst granular ductal cells were fewer and contained fewer secretory granules. Sodium potassium ATPase staining of striated ducts in de-ligated glands was similar to that of control glands. It can be concluded that rat submandibular glands can regenerate following severe atrophy and secrete normal amounts of saliva containing broadly a full profile of secretory proteins. In contrast to acinar cells, ductal cells appear not to recover full function. [source] Adrenal metastases of malignant melanoma: Characteristic computed tomography appearancesJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2005A Rajaratnam Summary Malignant melanoma is an extremely aggressive form of cancer. Adrenal metastases are found in 50% of cases of malignant melanoma, and are most often clinically and biochemically silent. Clinical presentation varies, and the diagnosis of adrenal metastases is often made incidentally, and frequently years after treatment of the primary lesion. An adrenal mass lesion seen on a CT scan, greater than 5 cm in diameter, with central or irregular areas of necrosis/haemorrhage (and no lipomatous component) is characteristic of a metastasis from malignant melanoma, in the setting of normal gland function. If these features are bilateral, they are pathognomonic. Oval, low-attenuation (on CT) adrenal masses less than 3 cm in diameter should not be considered benign in a patient with any prior history of melanoma. Careful imaging review of the adrenal glands should be undertaken in all patients with malignant melanoma. Early diagnosis of these distant metastases has important prognostic and therapeutic implications. The four cases presented illustrate the spectrum of presentations and clinical course of adrenal metastases from malignant melanoma. The accompanying CT images show the characteristic appearances of adrenal metastases. [source] Coexistence of Sjögren's syndrome and sarcoidosis: a report of five casesJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 6 2007M. J. Mansour Background:, Sjögren's syndrome (SS) and sarcoidosis are diseases that can affect the salivary glands and result in the loss of salivary gland function. Most of the criteria used for the diagnosis of SS exclude sarcoidosis before establishing the diagnosis of SS. However, several reports have suggested the coexistence of both SS and sarcoidosis in the same patient. Objective:, The purpose of this study was to present five cases that support a true coexistence of sarcoidosis and SS. Methods:, Clinical and laboratory findings of patients with evidence of having both SS and sarcoidosis were reviewed. The diagnosis of SS was based on the European community criteria; the diagnosis of sarcoidosis was based on the presence of serological, radiographic and/or histopathologic findings that are consistent with sarcoidosis. Results:, All patients fulfilled the criteria for the diagnosis of both diseases. Conclusion:, Our findings appear to support a true coexistence of sarcoidosis with SS. Therefore, it is reasonable to suggest removing the exclusion of sarcoidosis from the diagnostic criteria for SS. [source] Comparison of Serum-Free Thyroxine Concentrations Determined by Standard Equilibrium Dialysis, Modified Equilibrium Dialysis, and 5 Radioimmunoassays in DogsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 3 2004Sara Schachter Measurement of serum-free thyroxine (fT4) concentration provides a more accurate assessment of thyroid gland function than serum thyroxine (T4) or 3,5,3'-triiodothyronine (T3). Techniques for measuring serum fT4 concentration include standard equilibrium dialysis (SED), radioimmunoassay (RIA), and a combination of both (modified equilibrium dialysis [MED]). This study compared results of serum fT4 measurements by means of SED, MED, and 5 RIAs in 30 healthy dogs, 10 dogs with hypothyroidism, and 31 euthyroid dogs with concurrent illness for which hypothyroidism was a diagnostic consideration. Serum fT4 concentrations were comparable when determined by the SED and MED techniques, and mean serum fT4 concentrations were significantly (P<.01) lower in dogs with hypothyroidism than in healthy dogs and euthyroid dogs with concurrent illness. Significant (P < .05) differences in fT4 concentrations were identified among the 5 RIAs and among the RIAs and MED and SED. Serum fT4 concentrations were consistently lower when fT4 was determined by the RIAs, compared with either equilibrium dialysis technique. Serum fT4 concentrations were significantly lower (P < .01) in dogs with hypothyroidism than in healthy dogs for all RIAs; were significantly lower (P < .05) in dogs with hypothyroidism than in euthyroid dogs with concurrent illness for 4 RIAs; and were significantly lower (P < .01) in euthyroid dogs with concurrent illness than in healthy dogs for 4 RIAs. RIAs had the highest number of low serum fT4 concentrations in euthyroid dogs with concurrent illness. This study documented differences in test results among fT4 assays, emphasizing the importance of maintaining consistency in the assay used to measure serum fT4 concentrations in the clinical or research setting. [source] Database of cattle candidate genes and genetic markers for milk production and mastitisANIMAL GENETICS, Issue 6 2009J. Ogorevc Summary A cattle database of candidate genes and genetic markers for milk production and mastitis has been developed to provide an integrated research tool incorporating different types of information supporting a genomic approach to study lactation, udder development and health. The database contains 943 genes and genetic markers involved in mammary gland development and function, representing candidates for further functional studies. The candidate loci were drawn on a genetic map to reveal positional overlaps. For identification of candidate loci, data from seven different research approaches were exploited: (i) gene knockouts or transgenes in mice that result in specific phenotypes associated with mammary gland (143 loci); (ii) cattle QTL for milk production (344) and mastitis related traits (71); (iii) loci with sequence variations that show specific allele-phenotype interactions associated with milk production (24) or mastitis (10) in cattle; (iv) genes with expression profiles associated with milk production (207) or mastitis (107) in cattle or mouse; (v) cattle milk protein genes that exist in different genetic variants (9); (vi) miRNAs expressed in bovine mammary gland (32) and (vii) epigenetically regulated cattle genes associated with mammary gland function (1). Fourty-four genes found by multiple independent analyses were suggested as the most promising candidates and were further in silico analysed for expression levels in lactating mammary gland, genetic variability and top biological functions in functional networks. A miRNA target search for mammary gland expressed miRNAs identified 359 putative binding sites in 3,UTRs of candidate genes. [source] MUC-1 mucin in normal human salivary glands detected by HMFG-1 and HMFG-2 monoclonal antibodies,APMIS, Issue 2 2008SANTA PONCE-BRAVO The aim of this study was to determine the immunoexpression of normal salivary gland cells using two human milk fat globule membrane protein antibodies (HMFG-1 and HMFG-2). Paraffin-embedded, 5 ,m-thick slides from parotid and submandibular gland tissues were cut and immunostained with monoclonal antibodies HMFG-1 and HMFG-2 against MUC1 protein. HMFG antigens were found in secretory epithelial cells and ductal cells lining the striated and intercalated ducts in the intraductal secretion material, and sometimes in the myoepithelial cells. Our results suggest that HMFG-1 and HMFG-2 proteins may play a role in normal salivary gland function, mainly in the manufacturing and secretion of saliva. [source] Effectiveness of rituximab treatment in primary Sjögren's syndrome: A randomized, double-blind, placebo-controlled trial,ARTHRITIS & RHEUMATISM, Issue 4 2010J. M. Meijer Objective To study the efficacy and safety of B cell depletion with rituximab, a chimeric murine/human anti-CD20 monoclonal antibody, in patients with primary Sjögren's syndrome (SS) in a double-blind, randomized, placebo-controlled trial. Methods Patients with active primary SS, as determined by the revised American,European Consensus Group criteria, and a rate of stimulated whole saliva secretion of ,0.15 ml/minute were treated with either rituximab (1,000 mg) or placebo infusions on days 1 and 15. Patients were assigned randomly to a treatment group in a ratio of 2:1 (rituximab:placebo). Followup was conducted at 5, 12, 24, 36, and 48 weeks. The primary end point was the stimulated whole saliva flow rate, while secondary end points included functional, laboratory, and subjective variables. Results Thirty patients with primary SS (29 female) were randomly allocated to a treatment group. The mean ± SD age of the patients receiving rituximab was 43 ± 11 years and the disease duration was 63 ± 50 months, while patients in the placebo group were age 43 ± 17 years and had a disease duration of 67 ± 63 months. In the rituximab group, significant improvements, in terms of the mean change from baseline compared with that in the placebo group, were found for the primary end point of the stimulated whole saliva flow rate (P = 0.038 versus placebo) and also for various laboratory parameters (B cell and rheumatoid factor [RF] levels), subjective parameters (Multidimensional Fatigue Inventory [MFI] scores and visual analog scale [VAS] scores for sicca symptoms), and extraglandular manifestations. Moreover, in comparison with baseline values, rituximab treatment significantly improved the stimulated whole saliva flow rate (P = 0.004) and several other variables (e.g., B cell and RF levels, unstimulated whole saliva flow rate, lacrimal gland function on the lissamine green test, MFI scores, Short Form 36 health survey scores, and VAS scores for sicca symptoms). One patient in the rituximab group developed mild serum sickness,like disease. Conclusion These results indicate that rituximab is an effective and safe treatment strategy for patients with primary SS. [source] Interleukin-12 induces salivary gland dysfunction in transgenic mice, providing a new model of Sjögren's syndromeARTHRITIS & RHEUMATISM, Issue 12 2009Jelle L. Vosters Objective Interleukin-12 (IL-12) is a pleiotropic cytokine that is elevated in the affected organs of patients with Sjögren's syndrome (SS). We have previously reported that overexpression of IL-12 in CBA mice leads to mononuclear infiltration of salivary and lacrimal glands, as well as to expansion of bronchial lymphoid tissue and decreased mucociliary clearance. Because xerostomia is one of the most important clinical features in SS patients, our main objective in the current study was to evaluate salivary gland function in IL-12,transgenic mice. Our secondary objective was to further characterize this animal model and to determine if the changes observed in these mice are representative of those observed in patients with SS overall. Methods Pilocarpine-stimulated salivary flow was used to address salivary gland function in a large group of IL-12,transgenic mice bred onto the autoimmune-prone SJL background. Furthermore, salivary glands were removed to assess the formation of infiltrates in the glands and gland morphology. Serum was also collected from these animals to investigate the formation of autoantibodies. Results Pilocarpine-stimulated salivary flow was significantly lower in IL-12,transgenic mice than in wild-type controls. Salivary glands from transgenic mice exhibited an increase in both the number and the size of lymphocytic foci, versus glands from age-matched controls. Furthermore, the acini in transgenic mice were fewer in number and larger in size compared with acini in controls. An age-dependent increase in anti-SSB/La antibodies was observed in IL-12,transgenic mice and was accompanied by an increase in antinuclear antibodies. Conclusion Our findings indicate that a number of conditions associated with SS are exhibited by IL-12,transgenic SJL mice and that this model might be useful in researching multiple aspects of the disease. [source] Inflammatory stimuli accelerate Sjögren's syndrome,like disease in (NZB × NZW)F1 miceARTHRITIS & RHEUMATISM, Issue 5 2008Umesh S. Deshmukh Objective This study was undertaken to determine whether induction of systemic inflammation accelerates the development of Sjögren's syndrome (SS) in genetically susceptible mice. Methods Female (NZB × NZW)F1 mice were treated with either Freund's incomplete adjuvant (IFA) or phosphate buffered saline (PBS) at monthly intervals. Salivary gland function was monitored by measuring pilocarpine-induced saliva volume. Mice were killed at different time points and examined for sialadenitis and salivary gland,infiltrating cells. Sera were analyzed for autoantibodies to salivary gland antigens, nuclear antigens, and Ro60. Results While IFA-treated mice had significantly decreased salivary secretion 7 weeks after the initial treatment, salivary secretion did not decrease in PBS-treated controls until 17 weeks. At 7 weeks, the severity of sialadenitis and the number of T and B cells infiltrating the salivary glands did not differ between the 2 groups. However, at this time point IFA-treated mice showed significantly higher frequencies of CD11clow, B220+, Ly6C+, mouse PDCA-1+ dendritic cells (DCs) in the salivary glands. While levels of autoantibodies did not differ between the 2 groups at early time points, by late time points IFA-treated mice had higher levels. The gland dysfunction observed in IFA-treated mice at earlier time points did not correlate with the severity of sialadenitis or levels of autoantibodies. Instead, it was associated with increased frequency of plasmacytoid DCs in the gland. Conclusion Our data suggest that generalized inflammatory stimuli can accelerate the development of SS-like disease in (NZB × NZW)F1 mice, and that gland dysfunction in SS can develop prior to the generation of a robust adaptive autoimmune response. [source] 2435: Control of the Meibomian gland in health and diseaseACTA OPHTHALMOLOGICA, Issue 2010DA SULLIVAN Purpose The meibomian gland is extremely important in maintaining the health and integrity of the ocular surface. This gland, through its lipid synthesis and secretion, promotes the stability and prevents the evaporation of the tear film. Conversely, meibomian gland dysfunction (MGD) leads to a decreased stability and increased evaporation of the tear film. Indeed, meibomian gland dysfunction is thought to be the major cause of dry eye syndromes throughout the world. Our goal is to advance understanding of the regulation of meibomian gland function and the mechanisms underlying MGD. Methods Procedures included the immortalization of human meibomian gland epithelial cells with human telomerase reverse transcriptase, the evaluation of cellular responsiveness, and the identification of glandular gene expression changes in MGD. Gene analyses were conducted with Illumina HumanHT-12 v3 Expression BeadChips and Geospiza bioinformatics software. Results To date we have [a] immortalized human meibomian gland epithelial cells that respond to secretagogue, growth factor, neurotransmitter and hormone exposure with alterations in proliferation, differentiation, signaling, gene expression and/or lipogenesis; [b] discovered human meibomian gland genes that may facilitate the development and/or progression of MGD. These genes encode proteins that promote keratinization and amplify inflammation. Conclusion Our findings advance our understanding of the control of the meibomian gland in both health and disease. [Acknowledgments: S.M. Richards, M. Hatton, A.M. Fay and K. Lo; Supported by grants from NIH (R01EY05612) and Alcon] Commercial interest [source] 2436: A critical look at meibometry as a means to monitor Meibomian gland functionACTA OPHTHALMOLOGICA, Issue 2010P VERSURA Purpose To evaluate the diagnostic performance of meibometry in classifying and quantifying Meibomian gland dysfunction(MGD) Methods Ninety-six patients with MGD (138 eyes, 62 women, 34 men) and 30 normal control subjects(55 eyes)were enrolled. Eighty six eyes were classified as high delivery (HD)-MGD (meibomian seborrhea/hypersecretory MGD), 52 as low delivery (LD)-MGD on the basis of expression quality scores and morphological signs. Direct Meibometry (DM) measurements were made with an MB550 Meibometer (Courage-Khazaka GmbH). Standard curves were constructed relating arbitrary Meibometer optical density units (AU). Integrated Meibometry (IM) was performed on scanned images of the lipid blots. Symptoms were scored by OSDI,Schirmer test I, Break Up Time (BUT), tear osmolarity (Tearlab, Ocusense), conjunctival scraping cytology were performed. Statistical analysis used SPSS 14.0 and MedCalc 5.0 Results AU values plotted on a log scale correlated highly with the lipid equivalent values (R2= 0.913). Significant differences were found between control subjects vs all MGD patients and between HD vs LD-MGD patients for all the parameters evaluated. In particular: controls: 300+/-121 AU (0.04+/-0.015 microliter), LD-MGD: 218+/-122 AU (0.03+/-0.015) and HD-MGD: 564+/-115 AU (0.07+0.015) (median+/-SD). Significant correlation was found DM vs IM (r=0.691,p<0.0001) and DM was shown to be correlated with BUT, OSDI score, scraping score and tear osmolarity, especially in LD-MGD patients. The selected DM diagnostic cut off for LD-MGD was <275 AU (sens 73, spec 60, PPV 63) and for HD-MGD was >450 AU; (sens 86, spec 87, PPV 91) Conclusion Meibometry is confirmed to be a reliable method to distinguish normal subjects from MGD subgroups with a good degree of accuracy [source] Frontiers in sebaceous gland biology and pathologyEXPERIMENTAL DERMATOLOGY, Issue 6 2008Christos C. Zouboulis Abstract:, The development of experimental models for the in vitro study of human sebaceous gland turned down the theory of a phylogenetic relict and led to the identification of several, unknown or disregarded functions of this organ. Such functions are the production of foetal vernix caseosa, the influence of three-dimensional organization of the skin surface lipids and the integrity of skin barrier and the influence on follicular differentiation. In addition, the sebaceous gland contributes to the transport of fat-soluble antioxidants from and to the skin surface, the natural photoprotection, the pro- and antiinflammatory skin properties and to the innate antimicrobial activity of the skin. It is mainly responsible for skin's independent endocrine function, the hormonally induced skin ageing process, the steroidogenic function of the skin as well as its thermoregulatory and repelling properties and for selective control of the hormonal and xenobiotical actions of the skin. Interestingly, sebocytes, at least in vitro, preserve characteristics of stem-like cells despite their programming for terminal differentiation. This review reports on various sebaceous gland functions, which are currently under investigation, including its role on the hypothalamus,pituitary,adrenal-like axis of the skin, the impact of acetylcholine on sebocyte biology, the activity of ectopeptidases as new targets to regulate sebocyte function, the effects of vitamin D on human sebocytes, the expression of retinoid metabolizing cytochrome P450 enzymes and the possible role of sebum as vehicle of fragrances. These multiple homeostatic functions award the sebaceous gland the role ,brain of the skin' and the most important cutaneous endocrine gland. [source] |