***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND And rogenetic alopecia is a common condition , with severe attendant psychosocial implication s , and for which it is difficult to obtain a satisfactory degree of clinical improvement . OBJECTIVE To explore the possible clinical benefit of injecting platelet-derived growth factors into the scalp of patients using a specific autologous blood concentrate . MATERIAL S AND METHODS Two injections of a leukocyte platelet – rich plasma ( L-PRP ) with the addition of concentrated plasmatic proteins were administered at baseline and after 3 months ( single spin at baseline and double-spin centrifugation at 3 months ) .  Macrophotographs  were taken at baseline and after 6 months , and 2 independent evaluators rated them using Jaeschke rating of clinical change . RESULTS Sixty-four consecutive patients were enrolled . Some improvement was seen in all patients by 1 evaluator and in 62 by the other . The mean change in clinical rating was 3.2 ( 95 % confidence interval [ CI ] , 2.9–3.5 ) and 3.9 ( 95 % CI , 3.5–4.3 ) , and the proportion of patients reaching a clinical ly important difference was 40.6 % and 54.7 % , according to the 2 evaluators , respectively . CONCLUSION Our pilot study may provide preliminary evidence that this treatment may induce some degree of clinical advantage for male- and female-pattern baldness . This may warrant the design of r and omized controlled clinical trials to formally test this procedure In recent years quality of life instruments have been featured as primary outcomes in many r and omized trials . One of the challenges facing the investigator using such measures is determining the significance of any differences observed , and communicating that significance to clinicians who will be applying the trial results . We have developed an approach to elucidating the significance of changes in score in quality of life instruments by comparing them to global ratings of change . Using this approach we have established a plausible range within which the minimal clinical ly important difference ( MCID ) falls . In three studies in which instruments measuring  dyspnea , fatigue , and emotional function in patients with chronic heart and lung disease were applied the MCID was represented by mean change in score of approximately 0.5 per item , when responses were presented on a seven point Likert scale . Furthermore , we have established ranges for changes in question naire scores that correspond to moderate and large changes in the domains of interest . This information will be useful in interpreting question naire scores , both in individuals and in groups of patients participating in controlled trials , and in the planning of new trials BACKGROUND Treatments for alopecia are in high dem and , but not all are safe and reliable . Dalteparin and protamine microparticles ( D/P MPs ) can effectively carry growth factors ( GFs ) in platelet‐rich plasma ( PRP ) . OBJECTIVE To identify the effects of PRP‐containing D/P MPs ( PRP&D/P MPs ) on hair growth . METHODS & MATERIAL S Participants were 26 volunteers with thin hair who received five local treatments of 3 mL of PRP&D/P MPs ( 13 participants ) or PRP and saline ( control , 13 participants ) at 2‐ to 3‐week intervals and were evaluated for 12 weeks . Injected areas comprised frontal or parietal sites with lanugo‐like hair . Experimental and control areas were photographed . Consenting participants underwent biopsies for histologic examination . RESULTS D/P MPs bind to various GFs contained in PRP . Significant differences were seen in hair cross‐section but not in hair numbers in PRP and PRP&D/P MP injections . The addition of D/P MPs to PRP result ed in significant stimulation in hair cross‐section . Microscopic findings showed thickened epithelium , proliferation of collagen fibers and fibroblasts , and increased vessels around follicles . CONCLUSION PRP&D/P MPs and PRP  facilitated hair growth  but D/P MPs  provided additional hair growth . The authors have indicated no significant interest with commercial supporters Platelet-rich plasma ( PRP ) has become a newer method for the treatment of various types of alopecia . In this prospect i ve study , safety , efficacy and feasibility of PRP injections in treating and rogenic alopecia were assessed . Eleven patients suffering from hair loss due to and rogenic alopecia and not responding to 6 months treatment with minoxidil and finasteride were included in this study . The hair pull test was performed before every treatment session . A total volume of 2 - 3 cc PRP was injected in the scalp by using an insulin syringe . The treatment was repeated every two weeks , for a total of four times . The outcome was assessed after 3 months by clinical examination , macroscopic photos , hair pull test and patient 's overall satisfaction . Results : A significant reduction in hair loss was observed between first and fourth injection . Hair count increased from average number of 71 hair follicular units to 93 hair follicular units . Therefore , average mean gain is 22.09 follicular units per cm2 . After the fourth session , the pull test was negative in 9 patients . Conclusion : PRP injection is a simple , cost effective and feasible treatment option for and rogenic alopecia , with high overall patient satisfaction Background : Platelet-rich plasma ( PRP ) is defined as an autologous concentration of plasma with a greater count of platelets than that of whole blood . Its action depends on the released growth factors from platelets . It has been investigated and used in numerous fields of medicine . Recently , PRP has received growing attention as a potential therapeutic tool for hair loss . Aims : To evaluate the efficacy and safety of PRP injections in the scalp of patients with and rogenetic alopecia . Setting s and Design : Prospect i ve cohort study . Material s and Methods : 20 patients , 18 males and 2 females , with and rogenetic alopecia were enrolled in the study .  PRP was prepared using a single spin method ( Regenlab SA ) . Upon activation , it was injected in the and rogen-related areas of scalp . Three treatment sessions were performed with an interval of 21 days and a booster session at 6 months following the onset of therapy . Statistical Analysis : Statistical analysis of the data was performed using the Statistical Package for the Social Sciences ( SPSS ) , version 19.0 ( IBM , NY , USA ) . Results : Hair loss reduced and at 3 months it reached normal levels . Hair density reached a peak at 3 months ( 170.70 ± 37.81 , P < 0.001 ) . At 6 months and at 1 year , it was significantly increased , 156.25 ± 37.75 ( P < 0.001 ) and 153.70 ± 39.92 ( P < 0.001 ) respectively , comparing to baseline . Patients were satisfied with a mean result rating of 7.1 on a scale of 1 - 10 . No remarkable adverse effects were noted . Conclusions : Our data suggest that PRP injections may have a positive therapeutic effect on male and female pattern hair loss without remarkable major side effects . Further studies are needed to confirm its efficacy UNLABELLED Platelet-rich plasma ( PRP ) has emerged as a new treatment modality in regenerative plastic surgery , and preliminary evidence suggests that it might have a beneficial role in hair regrowth . Here , we report the results of a r and omized , evaluator-blinded , placebo-controlled , half-head group study to compare , with the aid of computerized trichograms , hair regrowth with PRP versus placebo . The safety and clinical efficacy of autologous PRP injections for pattern hair loss were investigated . PRP , prepared from a small volume of blood , was injected on half of the selected patients ' scalps with pattern hair loss . The other half was treated with placebo . Three treatments were administered to each patient at 30-day intervals . The endpoints were hair regrowth , hair dystrophy as measured by dermoscopy , burning or itching sensation , and cell proliferation as measured by Ki67 evaluation . Patients were followed for 2 years . Of the 23 patients enrolled , 3 were excluded . At the end of the 3 treatment cycles , the patients presented clinical improvement in the mean number of hairs , with a mean increase of 33.6 hairs in the target area , and a mean increase in total hair density of 45.9 hairs per cm² compared with baseline values . No side effects were noted during treatment . Microscopic evaluation showed the increase of epidermis thickness and of the number of hair follicles 2 weeks after the last PRP treatment compared with baseline value ( p < .05 ) . We also observed an increase of Ki67(+ ) keratinocytes in the epidermis and of hair follicular bulge cells , and a slight increase of small blood vessels around hair follicles in the treated skin compared with baseline ( p < .05 ) . Relapse of and rogenic alopecia was not evaluated in all patients until 12 months after the last treatment . After 12 months , 4 patients reported progressive hair loss ; this was more evident 16 months after the last treatment . Those four patients were re-treated . Our data clearly highlight the positive effects of PRP injections on male pattern hair loss and absence of major side effects .  PRP may serve as a safe and effective treatment option against hair loss ; more extensive controlled studies are needed . SIGNIFICANCE Platelet-rich plasma ( PRP ) has emerged as a new treatment modality in regenerative plastic surgery , and preliminary evidence suggests that it might have a beneficial role in hair regrowth . Here , the results of a r and omized , placebo-controlled , half-head group study to compare the hair regrowth with PRP versus placebo are reported . Hair regrowth was quantified by a blinded evaluator using computerized trichograms . The safety and clinical efficacy of autologous PRP injections for pattern hair loss were investigated . Of the 23 patients enrolled , 3 were excluded . At the end of the 3 treatment cycles , the patients presented clinical improvement in the mean number of hairs , with a mean increase of 33.6 hairs in the target area and a mean increase in total hair density of 45.9 hairs per cm² compared with baseline values . No side effects were noted during treatment . The data clearly highlight the positive effects of PRP injections on  male pattern hair loss  and absence of major side effects .  PRP may serve as a safe and effective treatment option against hair loss ; more extensive controlled studies are needed BACKGROUND Platelet-rich plasma ( PRP ) was identified as having a beneficial effect in alopecia and has been postulated as a new therapy for and rogenetic alopecia ( AGA ) . OBJECTIVE To assess the efficacy of PRP for the treatment of AGA . MATERIAL S AND METHODS This was a r and omized , placebo-controlled , double-blind study in 25 patients with AGA .  Platelet-rich plasma was injected in half-head and the other half-head with placebo . Each patient received a total of 3 treatments of PRP , 1 month apart . RESULTS Six months after the first treatment with PRP , significant differences were seen in mean anagen hairs ( 67.6 ± 13.1 ) , telogen hairs ( 32.4 ± 13.1 ) , hair density ( 179.9 ± 62.7 ) , and terminal hair density ( 165.8 ± 56.8 ) when compared with baseline ( p < .05 ) . Platelet-rich plasma was also found to increase hair density when comparing with the control side ( p < .05 ) . For the first time , the authors found a correlation between anagen hairs and patients > 40 years and beginning of AGA ≥25 years old ( p < .05 ) and hair density and male sex , age ⩽40 years , positive family history of AGA and > 10 years of duration of the disease ( p < 0.05 ) . CONCLUSION Application of PRP showed a positive effect on AGA and could be regarded as an adjuvant therapy for AGA Aim : The aim of the study was to evaluate the efficacy of platelet-rich plasma ( PRP ) in the treatment of chronic alopecia areata ( AA ) . Material and Methods : This is a prospect i ve study that was conducted at Kamal Hospital , Kaushambi in which 20 patients who attended the outpatient department were enrolled for the study . All the patients had h/o patches and taken various line of treatments for a duration of 2 years . All the patients were biopsy-proven positive for AA disease . There was no r and omisation done since all of them were healthy young adults . The patients ’ age ranged from 25 to 35 years , and none of them had any co-morbidities . Results : Of 20 patients , only one patient had a relapse . None of the patients had any side effects , and all of them tolerated the procedure well . Conclusion : We wish to conclude that PRP has a definite role in treating AA infections . However , still more long-term follow-up , studies are required for further validation of results and labelling it as a 100 % cure for people suffering from AA with recurrences which are so common Background : Follicular units are commonly used in baldness surgery , and they have become a global procedure for both male and female patients . The yield from micrografts varies between 70 and 85 percent . Yield is determined by factors such as quality of the harvested donor area , preparation of the units , care taken during the implantation procedure , and follicular apoptosis . To improve hair density and stimulate follicular unit growth , an experimental study was design ed using platelet plasma growth factors obtained from the patient 's autologous plasma . Methods : The author established a protocol within a group of 20 patients with male pattern baldness . The data showed a gaussian distribution ; to compare the two procedures involved in this clinical trial , the paired t test was used . Results : The author observed a significant difference in the yield of follicular units when comparing the experimental with the control areas of the scalp ( p < 0.001 ) . The areas treated with platelet plasma growth factors demonstrated a yield of 18.7 follicular units per cm2 , 
    Output:
    
Overall , the use of PRP injections in patients with and rogenic alopecia seems effective with respect to promoting lost hair regrowth , decreasing hair loss and increasing hair thickness .
The effects appear to be progressive from the first injection session , to peak after 3 to 5 sessions and to be attenuated in the absence of further injections .