Eyelash Follicles Research Articles

Acupuncture for acute hordeolum.

Acupuncture for acute hordeolum.

Do Demodex mites play a role in pterygium development?

Numerous reports point to Demodex mites as the aetiology of certain eye and skin conditions, hence it is highly probable that infestation with these mites may also play a role in the aetiology and pathogenesis of pterygium. Therefore here we present a hypothesis: whether the presence of Demodex mites in eyelash hair follicles significantly correlates with the presence of pterygia, which could point to a potential role of these mites in the development of such lesions. We present preliminary data for supporting this hypothesis. These results were collected from a group of 69 subjects, including 39 with pterygium. Subjects were studied for the presence of Demodex folliculorum and/or D. brevis within eyelash follicles. The sample was defined as positive if at least one parasite, larva or egg were present. Preliminary statistical analyses were performed, and indicated a significant relationship between Demodex mite infestation and the presence of pterygium (p<0.05). This suggests that demodicosis could be one of the factors causing pterygium and significantly contribute to its development. Subjects who had both pterygium and Demodex infestation formed a dominant group. The proportion of subjects with both pterygia and Demodex presence is high at 93.33%, while the proportion of subjects without pterygia who have mites is low at 20.51%. Aforementioned results support our working hypothesis that infestation with Demodex mites may result in pterygium development and therefore patients diagnosed with pterygium should be assessed for the presence of Demodex to verify our preliminary results. In the present paper, we discuss potential influence of Demodex on conjunctiva and propose a hypothetical pathological mechanism linking the development of pterygia with demodicosis.

Prevalence of Demodex spp. in eyelash follicles in different populations.

IntroductionThe pathologic relevance of Demodex infestation in blepharitis is still controversial. The aim of the study was to determine the prevalence of Demodex spp. in eyelash follicles and its relationship to eye symptoms.Material and methodsA total of 290 individuals were studied for the presence of Demodex folliculorum and Demodex brevis within eyelash follicles. Participants belonged to one of four groups: inpatients, drug abusers, health professionals, and medical students. Ten eyelashes were epilated from each subject, placed on microscope slides and examined for parasites. The sample was defined as positive if at least one parasite or parasite's ova were present. The presence of parasites was analyzed according to age, gender, place of living, reported eye problems, and use of contact lenses or glasses.ResultsThe prevalence of Demodex spp. infestation among all studied subjects was 41%, with the highest infestation rate among inpatients (p < 0.01) and elderly people (p < 0.001). No difference regarding the presence of Demodex was found between women and men (p = 0.76). Demodex folliculorum was about 2.4 times more frequent than D. brevis. The prevalence of Demodex spp. in subjects with and without eye complaints suggesting blepharitis was similar (41.6% vs. 40.2%, respectively, p = 0.9). On the other hand, wearing glasses was linked to Demodex infestation (48.4% vs. 32.3%, p < 0.01).ConclusionsDemodex is a common saprophyte found in human eyelash follicles. Its presence might be related to some ocular discomfort; however, in the vast majority of cases the infestation seems to be asymptomatic.

Investigating the effects of metabolic dysregulation on hair follicles: a comparison of HIV-infected women with and without central lipohypertrophy

Normal lipid metabolism and functioning of the peroxisome proliferator-activated receptor gamma (PPAR-gamma) in the sebaceous gland is critical to maintaining a normal hair follicle. Human immunodeficiency virus (HIV) infection affects lipid metabolism; some have hypothesized a link between PPAR-gamma function and lipodystrophy in HIV infection. Our objective was to determine whether lipodystrophy is associated with altered hair characteristics in HIV-infected women from the Women's Interagency HIV Study. Hair characteristics and scalp inflammation were assessed by an interviewer-administered questionnaire. Central lipohypertrophy and peripheral lipoatrophy were defined by self-report of moderate to severe fat gain in central body sites and fat loss in peripheral body sites, respectively confirmed by clinical examination. Additional covariates considered in the analyses included demographics, behavioral characteristics, medical history, and HIV-related factors. There were 1037 women with data on all study variables; 76 women reported central lipohypertrophy, while only four women reported lipoatrophy. Women with central lipohypertrophy were more likely to be older, had a self-reported history of injection drug use, statin medication use, diabetes, elevated cholesterol, and have self-reported less hair and shorter eyelashes. After adjustment for age, central lipohypertrophy was associated with shorter eyelashes (OR 2.3; 95% CI 1.4-3.8). Central lipohypertrophy was not associated with change in scalp hair texture or scalp inflammation in this cohort. Rather, we found an association between central lipohypertrophy and shorter eyelash length. This finding may be explained by an influence of prostaglandin E2 mediators on eyelash follicles.

Chondroid syringoma: A rare lid tumor

Sir, Chondroid syringoma is a rare primary skin tumor (0.01% to 0.1% of primary skin tumors).[1] Though its very common occurrence is in head and the neck region, involvement of eyelids is extremely rare. In English literature we found 27 reported cases of chondroid syringoma involving ocular adnexa.[1,2] We are reporting a case of recurrent chondroid syringoma of upper eyelid in a young male. A 27-year-old male present with a slow growing painless mass in right upper lid since past 6 months duration. The mass was 1.5 cm × 1.5 cm firm, non-tender, sub-cutaneous and not fixed to underlying tissues [Fig. 1]. This was a recurrence of a lesion that had been removed by lamellar excision in the same site 2 years back. The recurrent mass was removed this time by pentagonal full thickness lid excision with re-construction by advancement eyelid flap. Histopathological examination showed tumor with variegated appearance. The epithelial component composed of round to oval cells with large nucleoli with scanty cytoplasm and the cells were arranged in nests and acinar pattern. The coating for epithelium of the glandular elements was two layered. The intervening stroma showed fibrosis and myxoid areas. No evidence of lacrimal gland tissue was noted in multiple sections [Fig. 2]. Figure 1 1.5 cm × 1.5 cm mass involving the right upper lid Figure 2 Histopathology showing glandular elements with two layered lining epithelium in myxoid matrix Chondroid syringoma is a tumor arising from the sweat glands which can be apocrine (found throughout the surface of lid) or eccrine (glands of Moll in association with eyelash follicles) with a mean age of 50 years (22-73 years).[1] Ozdal et al. in a study of 228 benign ocular adnexal tumors reported apocrine/eccrine hydrocystoma as very common and no case of Chondroid Syringoma was found in that series.[3] Tyagi et al. in their study of 207 eyelid tumors had one case of Chondroid syringoma with an incidence of 0.48% in their series.[4] This tumor was first described by Billroth[5] and the term chondroid syringoma was coined by Hirsh and Helwig to characterize the origin from sweat glands[6] though the appearance is like pleomorphic adenoma of lacrimal gland. A proper histopathological examination to rule out presence of normal lacrimal gland tissue external to the tumor capsule helps to differentiate chondroid syringoma.[1] The case being reported had tubular and cystic branching lumina with 2 layered epithelium showing an apocrine origin.[1] Chondroid syringoma is a benign tumor but incomplete excision can undergo malignant transformation.[1] Hence complete excision is advised. This case is being reported for its rarity (this is the 28th case in literature involving ocular adnexa), its occurrence in a young patient and the need to keep this rare entity as a differential diagnosis of eyelid tumors.

Role of Demodex folliculorum in the pathogenesis of blepharitis

Editor, T he ectoparasite Demodex folliculorum (Simon 1843) is most common parasite of humans. In the eye, D. folliculorum is found in the eyelash follicle. The aim of this study was to examine the prevalence of D. folliculorum in the eyelashes in patients with haematologic disorders. Eyelashes were collected from 95 patients of the Clinic of Haematology Pomeranian Medical University, Szczecin, Poland, and from 1091 healthy controls. There were 47 (49%) women and 48 (51%) men in the patients group (age range: 58.6 ± 13.1) and 759 (69.6%) women and 332 (30.4%) men in the control group (age range: 58.6 ± 13.0). From each patient, we aseptically collected two lashes from the upper right eyelid and two lashes from the upper left eyelid. The collected material was used in preparations examined using light microscopy (magnified 100 times). Infection of the examined subjects was confirmed by the detection of adult and larval forms of D. folliculorum. Demodex folliculorum is found in 21.8% of healthy controls and 18.9% of haematologic patients (Fig. 1; Table 1). In the control group, D. folliculorum occurred in 22.3% of women and in 20.8% of men. In patients with haematologic disorders, D. folliculorum occurred in 17.5% of women and in 25% of men. A much lower rate of infestation of D. folliculorum (12%) was found in immunosuppressed patients with rheumatoid arthritis (Ciftci et al. 2006). On the other hand, in patients with final-stage renal failure (ESRF) on dialysis treatment, D. folliculorum found in 44.4% of patients (Karincaoglu et al. 2005). In our study, the percentage of D. folliculorum infestation in haematologic patients ranged from 16% of patients with acute leukaemia, MPS and other haematologic diseases, and 21.7% with multiple myeloma, to about 24.1% in patients with nonHodgkin’s lymphoma and CLL. Seyhan et al. (2004) found D. folliculorum in the skin of patients with acute lymphocytic leukaemia (12%), acute myelocytic leukaemia (32%), chronic lymphocytic leukaemia (4%), chronic myelocytic leukaemia (10%), Hodgkin’s lymphoma (4%) and nonHodgkin’s lymphoma (38%). Demodex folliculorum seem to be a mediator of chronic blepharitis; some recommend that mites be sought in cilia of chronic blepharitis patients (Czepita et al. 2007). Elevated subjective symptoms of the ocular surface were caused by increased levels of D. folliculorum. Itching, burning, foreign body sensation, crusting and redness of the lid margin, and blurry vision are the main symptoms. Signs include disorders of eyelashes, lid margin inflammation, meibomian gland dysfunction, blepharoconjunctivitis and blepharokeratitis (Czepita et al. 2007). In the control group, the most common symptoms related to D. folliculorum infestation included sensitivity to light, dacryorrhea and itching of the eyelids; loss of eyelashes was the least common. In the group of haematology patients, dacryorrhea was most frequent, without any reports of sensitivity to smoke, light, foreign body sensation under the eyelids or loss of eyelashes. A 61.7% of D. folliculorum-infected patients in the ophthalmology clinic reported itching, and 59.1% reported red eyes (Inceboz et al. 2009). In our study, we found that D. folliculorum infestation was correlated with cylindrical dandruff in the lash roots, both in the control group and in haematologic patients. In patients with D. folliculorum infestation in eyelashes, we found trichiasis, meibomian gland dysfunction with lipid tear deficiency and conjunctival inflammation (Czepita et al. 2007). The prevalence of D. folliculorum in patients with haematologic diseases was similar to that of the control group. Demodicosis may cause itchiness in the eyelids and cylindrical dandruff in the lash roots.

Treatment for trichiasis through a combination of eyelash trephination and electrocautery

This article introduces 3-mm-deep eyelash trephination combined with electrocautery as a way to increase the success rate for treatment for trichiasis. We have modified surgical instruments, ready-made ophthalmic microtrephine and cautery tip for a 3-mm-deep eyelash trephination and electrocautery. After eyelash trephination with microtrephine, electrocautery was added with a bended cautery tip after embedding in the trephination site. The trephined eyelids were photographed biweekly and checked for recurrence until 8 weeks after operation. Eyelash trephination combined with electrocautery was carried out on 20 Korean patients. The number of removed cilia was 109. Of these, the number of successfully removed hair follicles was 89. During 8 weeks, the total recurring rate of eyelash trephination combined with electrocautery was 17%. In the case of hair follicle removal success with electrocautery, the recurring rate was as low as 11%, but in the case of hair follicle removal failure with electrocautery, recurring rate is 45%. We checked the depth of removed eyelash follicles, and the mean depth was 2.03 ± 0.085 mm in this study. No serious complication was found during the period of this study. The eyelash trephination combined with electrocautery for trichiasis is a method with a low recurrence rate and few complications.

Eyelid Alterations in Involutional Ectropion

Purpose: To describe the histological features of eyelid tissue in involutional ectropion carriers. Methods: An interventional case series study was performed evolving 52 involutional eyelid ectropion carriers submitted to Tarsal strip surgery. A full-thickness eyelid fragment was evaluated by light microscope and results were statistical analyzed. Results: The conjunctival substantia propria had an inflammatory mononuclear process. Meibomian glands and eyelash follicles were enlarged. Inflammatory cells permeated the glands and eyelashes follicles. Orbicularis muscle fibers were replaced by fibrosis in some areas. Solar elastosis and epithelial squamous cell metaplasia were also observed in the skin epithelium. Conclusion: Eyelid ectropion is associated with important lid margin alterations affecting the glands, eyelashes, and orbicularis muscle. Inflammation and fibrosis compromise and disturb eyelid function.

Enhancing the Growth of Natural Eyelashes: The Mechanism of Bimatoprost-Induced Eyelash Growth

Many women desire prominent eyelashes. In December 2008, bimatoprost ophthalmic solution 0.03% was approved for the treatment of hypotrichosis of the eyelashes in the United States. To review eyelash physiology and the proposed mechanisms by which the topical pros-tamide product bimatoprost enhances eyelash growth. Clinical and preclinical studies pertaining to the efficacy, safety, and mechanisms of action of bimatoprost are presented. Treatment with bimatoprost increases the percentage of eyelash follicles in anagen at any one time. This probably accounts for its ability to lengthen lashes. Bimatoprost-induced stimulation of melanogenesis appears to result in darker lashes and, at the same time, appears to increase the size of the dermal papilla and hair bulb, affecting lash thickness and fullness. Such effects, largely demonstrated in animal studies, are consistent with the results of a recent Food and Drug Administration phase III clinical trial. The favorable safety profile of bimatoprost in human subjects is probably secondary to the limited exposure of ocular tissues resulting from topical application at the base of the upper lashes. By influencing the eyelash hair cycle and follicles, bimatoprost ophthalmic solution 0.03% is a safe and effective means of enhancing eyelash growth. Dr. Cohen has served as a consultant and clinical trial participant for Allergan, Inc.

Trichiasis

Trichiasis is a lid margin disorder in which the eyelashes are misdirected toward the ocular surface. It is a major cause of ocular morbidity. Trichiasis is secondary to inflammation and scarring of the eyelash follicles. There is a frequent association between trichiasis and cicatricial entropion and the correct diagnosis is mandatory for a successful treatment. There are several options for the management of trichiasis and the main purpose is to eliminate the anomalous cilia and improve the patient’s comfort. Temporary measures include eye lubricants, contact lenses, and mechanical epilation. Surgical treatments have initial success but long-term results are poor and recurrences are frequent. Definitive trichiasis treatments include bipolar electrolysis, radiofrequency ablation, cryotherapy and laser ablation, and surgical procedures. The techniques are described in detail along with possible complications and outcome.

Characterization of anin vivomodel for the study of eyelash biology and trichomegaly: mouse eyelash morphology, development, growth cycle, and anagen prolongation by bimatoprost

Hypertrichosis or alopecia of the eyelashes is associated with various diseases or may be drug induced. Although neither increase nor loss of eyelashes is life threatening, eyelash disorders can be psychologically disturbing. However, as control of eyelash growth and the underlying mechanisms of eyelash hypo- or hypertrichosis are largely obscure, available therapy is limited. To improve this situation, we sought to establish a pragmatic, well-defined mouse model for the study and pharmacological investigation of eyelash follicle biology. We took a morphometric approach to establish an eyelash model using female C57BL/6J mice by comparing with pelage hairs and highlighting the differences. We next applied a hypertrichosis-triggering agent and investigated its effect using the model. In eyelashes, a synchronized growth cycle was observed after morphogenesis but was completed earlier than pelage hairs. Exogen was strictly regulated and occurred in every cycle in the eyelash. Otherwise, general morphological features of mouse eyelashes (shafts, follicles, morphogenesis and growth cycle) were comparable with those of pelage hairs. The eyelash growth-stimulatory agent in humans, bimatoprost, significantly extended the duration of anagen, resulting in more and longer eyelashes, but there was no evidence of follicle neogenesis. This study shows that mouse eyelashes offer an excellent in vivo model for the quantitative and qualitative analysis of eyelash morphology, development, growth cycle, exogen and pharmacological modulation. This model will help to elucidate the unknown molecular controls of eyelash growth, and to develop novel drugs to treat eyelash disorders.

Human eyelash characterization

Few biological data on human eyelash follicles have been reported in the literature. To characterize eyelash follicle growth, cycle and morphology, and further investigate the biological mechanisms that determine eyelash length, curl and pigmentation, compared with scalp hair follicle. Twenty-nine caucasian female volunteers aged between 26 and 60 years were enrolled in the study to provide eyelashes. Four of these volunteers were followed weekly for 9 months to characterize their eyelash cycle. Eyelash length and time of renewal were measured using a high-resolution camera and image analysis. Immunohistological study of the bulbs were performed on eyelid biopsies from 17 patients requiring block excision for ectropion repair. The calculated durations of anagen phase and complete cycle of the eyelashes were 34 + or - 9 and 90 + or - 5 days, respectively. Eyelash follicle growth rate was quite variable, with an average rate of 0.12 + or - 0.05 mm daily. Eyelash follicle morphology was very close to that of the scalp hair follicle, but some remarkable differences were noticed. For example, the K19-positive epithelial stem cell population was spread all along the follicle and not split into two reservoirs as seen in scalp hair follicles. Some asymmetry was detected in HSPG and CSPG, as well as K38 (formerly Ha8) and K82 (formerly Hb2) distribution, similar to that observed in curly hair. Finally, dopachrome tautomerase was found expressed in eyelash follicle melanocytes, while it was strikingly absent in scalp hair follicle melanocytes. The eyelash is structurally very close to curly hair but some biological processes related to follicle cycle and pigmentation differ markedly.

The canonical Wnt signaling antagonist DKK2 is an essential effector of PITX2 function during normal eye development

Local control of cell signaling activity and integration of inputs from multiple signaling pathways are central for normal development but the underlying mechanisms remain poorly understood. Here we show that Dkk2, encoding an antagonist of canonical Wnt signaling, is an essential downstream target of the PITX2 homeodomain transcription factor in neural crest during eye development. Canonical Wnt signaling is ectopically activated in central ocular surface ectoderm and underlying mesenchyme in Pitx2- and Dkk2-deficient mice. General ocular surface ectoderm identity is maintained during development in Dkk2-deficient mice but peripheral fates, including conjunctival goblet cells and eyelash follicles, are ectopically permitted within more central structures and eyelids are hypomorphic. Loss of DKK2 results in ectopic blood vessels within the periocular mesenchyme and PITX2 expression remains persistently high, providing evidence for a negative feedback loop. Collectively, these data suggest that activation of Dkk2 by PITX2 provides a mechanism to locally suppress canonical Wnt signaling activity during eye development, a paradigm that may be a model for achieving local or transient inhibition of pathway activity elsewhere during embryogenesis. We further propose a model placing PITX2 as an essential integration node between retinoic acid and canonical Wnt signaling during eye development.

The Prevalence of Demodex folliculorum in Blepharitis Patients and the Normal Population.

Purpose: Demodex folliculorum (DF), which is frequently found in patients with chronic blepharitis, is a well-known common inhabitant of eyelash follicles. In the present study, the prevalence of DF in seborrheic blepharitis patients and controls was investigated. In addition, the associations between the presence of DF and host factors (age, sex) were analyzed. Methods: A prospective, cross-sectional study was done involving 500 cases. In all, 6000 cilia from 170 patients with seborrheic blepharitis and 330 patients with normal eyes were examined for DF. Twelve eyelash samples were epilated from each patient and examined under the light microscope. Results: DF was found in 28.8% (49/170) of patients with blepharitis and in 26.7% (88/330) of controls. The difference between the two groups was not statistically significant. The overall prevalence was 27.4% (137/500) in all patients. Although the prevalence of DF increased with increasing age, no significant difference was found between the age groups. There was also no statistically significant difference for DF prevalence between males (28.9%; 71/246) and females (24.1%; 61/254). Conclusion: Our findings show a high DF prevalence in both blepharitis and control patients and no relationship was found between the presence of DF and host factors (age, sex).

O uso do laser de argônio no tratamento da triquíase

PURPOSE: To evaluate the effectiveness of thermoablation of eyelashes in trichiasis with Argon laser and to observe the patients' choice of topic or local anesthesia. METHODS: Prospective study of 55 eyelids of 39 patients with trichiasis treated with photocoagulation of the eyelash follicle with Argon green laser (Alcon® - USA). Age, sex, number of applications in each session, evolution after the application and preference for the anesthesic method were evaluated. The laser settings were: 150 µm aim 750 mW potency; 0.2 seconds exhibition. Each eyelash received no more than 9 applications per procedure. RESULTS: Of the 39 patients, 58.9% were female and 41% were male. Mean age was 71 years. There was resolution in 69% (38 patients), and 29% (16 eyelids) underwent a single procedure. The preference for local anesthesia is statistically significant. CONCLUSION: The results suggest that most patients chose local anesthesia for the treatment of trichiasis with argon laser and the thermoablation of eyelashes with argon green laser is an effective treatment of trichiasis.

Label-retaining cells (presumptive stem cells) of mice vibrissae do not express gap junction protein connexin 43.

We investigated whether connexin 43, a gap junction protein present in human epidermis and mouse hair follicle, can serve as a negative marker for keratinocyte stem cells. Experiments carried out in mouse pelage and vibrissae hair follicles demonstrated that most of the slowly cycling cells, detected as label-retaining cells, do not express connexin 43. In humans, cells with immunohistochemically undetectable levels of connexin 43 are found in the epidermal basal layer of neonatal foreskin, and in the follicular bulge region. About 10% of the basal keratinocytes are connexin 43 negative, as determined by flow cytometry. These cells are uniformly small and low in granularity suggesting that presumptive keratinocyte stem cells can be identified and separated based on connexin 43 expression.

Hair follicle stem cells.

The workshop on Hair Follicle Stem Cells brought together investigators who have used a variety of approaches to try to understand the biology of follicular epithelial stem cells, and the role that these cells play in regulating the hair cycle. One of the main concepts to emerge from this workshop is that follicular epithelial stem cells are multipotent, capable of giving rise not only to all the cell types of the hair, but also to the epidermis and the sebaceous gland. Furthermore, such multipotent stem cells may represent the ultimate epidermal stem cell. Another example of epithelial stem cell and transit amplifying cell plasticity, was the demonstration that adult corneal epithelium, under the influence of embryonic skin dermis could form an epidermis as well as hair follicles. With regards to the location of follicular epithelial stem cells, immunohistochemical and ultrastructural data was presented, indicating that cells with stem cell attributes were localized to the prominent bulge region of developing human fetal hair follicles. Finally, a new notion was put forth concerning the roles that the bulge-located stem cells and the hair germ cells played with respect to the hair cycle.

Retinal Evaluation After 810 nm Dioderm Laser Removal of Eyelashes

BACKGROUND When operating hair removal lasers on the face or in the periorbital region, even with an ocular shield in place, patients often report seeing “flashing lights” each time the laser is fired. This phenomenon suggests stimulation of retinal photoreceptors and raises laser safety issues. OBJECTIVE To perform retinal electrophysiologic studies to evaluate the safety of hair removal lasers in the periorbital region. METHODS Five patients with severe trichiasis secondary to trachoma were studied. The 810 nm Dioderm laser (Cynosure, Inc., Chelmsford, MA) was used to treat the eyelash follicles on the lower eyelid of each patient. Cox III metal eye shields (Oculo-Plastik, Inc., Montreal, Canada) were placed behind the eyelids of both eyes during the laser procedure. Prior to irradiation, a comprehensive ophthalmic evaluation including pupillary and slit-lamp examination, funduscopy, and full-field electroretinograms (ERGs) was performed. A comprehensive ophthalmic evaluation including ERG testing was repeated 30 minutes and 3–6 months after completion of treatment. An independent blinded assessor evaluated the ERG studies. Subjective reports of laser light sensation, pain, and discomfort during and after the laser procedure were also assessed. RESULTS There was no detectable change in slit-lamp, pupillary, or funduscopic evaluations after periorbital laser irradiation. Similarly the pre- and posttreatment ERGs were unchanged. Three patients reported seeing flashing lights during the procedure. CONCLUSION We found no ERG evidence of retinal damage after laser hair removal in the periorbital region, with Cox III-type ocular shields over the eyes, even when patients subjectively reported “flashing lights” during laser irradiation.

Eyelid Splitting With Excision or Microhyfrecation for Distichiasis

Distichiasis is a rare congenital or acquired condition in which an accessory row of eyelashes arises from the posterior lamella of the eyelid margin. Previously described surgical techniques to treat distichiasis can result in complications including trichiasis, loss of normal eyelashes, cicatricial entropion, and eyelid margin deformities. We describe a new technique in which the eyelid margin is split to expose the distichiasis eyelash follicles. Each aberrant eyelash follicle is individually excised or microhyfrecated and then removed. Seventeen eyelids in 5 patients with congenital or acquired distichiasis have been treated. We have achieved excellent functional and cosmetic results using this new technique.

Stem Cells of Pelage, Vibrissae, and Eyelash Follicles: The Hair Cycle and Tumor Formationa

Stem Cells of Pelage, Vibrissae, and Eyelash Follicles: The Hair Cycle and Tumor Formation^a