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Background The relationship between local hospital culture and transfusion rates following endovascular and surgical cardiovascular procedures has not been well studied. Methods and Results Patients undergoing coronary revascularization, aortic valve replacement, lower extremity peripheral vascular intervention, or carotid artery revascularization from up to 852 US hospitals in the Nationwide Readmissions Database were identified. Crude and risk‐standardized red blood cell transfusion rates were determined for each procedure. Pearson correlation coefficients were calculated between respective procedural transfusion rates. Median odds ratios were estimated to reflect between‐hospital variability in red blood cell transfusion rates following the same procedure for a given patient. There was wide variation in red blood cell transfusion rates across different procedures, from 2% following carotid endarterectomy to 29% following surgical aortic valve replacement. For surgical and endovascular modalities, transfusion rates at the same hospital were highly correlated for aortic valve replacement (r=0.67; P2, highest for coronary artery bypass graft surgery and surgical aortic valve replacement, indicating substantial site variation in transfusion rates. Conclusions After adjustment for patient‐related factors, wide variation in red blood cell transfusion rates remained across surgical and endovascular procedures employed for the same cardiovascular condition. Transfusion rates following these procedures are highly correlated at individual hospitals and vary widely across hospitals. In aggregate, these findings suggest that local institutional culture significantly influences the decision to transfuse following invasive cardiovascular procedures and highlight the need for randomized data to inform such decisions.

Quantum-dot cellular automata, is an extremely small size and a powerless nanotechnology. It is the possible alternative to current CMOS technology. Reversible QCA logic is the most important issue at present time to reduce power losses. This paper presents a novel reversible logic gate called the F-Gate. It is simplest in design and a powerful technique to implement reversible logic. A systematic approach has been used to implement a novel single layer reversible Full-Adder, Full-Subtractor and a Full AdderâSubtractor using the F-Gate. The proposed Full AdderâSubtractor has achieved significant improvements in terms of overall circuit parameters among the most previously cost-efficient designs that exploit the inevitable nano-level issues to perform arithmetic computing. The proposed designs have been authenticated and simulated using QCADesigner tool ver. 2.0.3. Keywords: QCA, F-Gate, Adder, Subtractor, Adderâsubtractor, QCADesigner

Abstract Background Drug abuse is hazardous and known to be prevalent among young adults, warranting efforts to increase awareness about harmful effects and to change attitudes. This study was conducted to assess the perceptions of a group of medical students from Pakistan, a predominantly Muslim country, regarding four drugs namely heroin, charas, benzodiazepines and alcohol. Results In total, 174 self-reported questionnaires were received (87% response rate). The most commonly cited reasons for why some students take these drugs were peer pressure (96%), academic stress (90%) and curiosity (88%). The most commonly cited justifiable reason was to go to sleep (34%). According to 77%, living in the college male hostel predisposed one to using these drugs. Sixty percent of students said that the drugs did not improve exam performance, while 54% said they alleviated stress. Seventy-eight percent said they did not intend to ever take drugs in the future. Females and day-scholars were more willing to discourage a friend who took drugs. Morality (78%), religion (76%) and harmful effects of drugs (57%) were the most common deterrents against drug intake. Five suggestions to decrease drug abuse included better counseling facilities (78%) and more recreational facilities (60%). Conclusion Efforts need to be made to increase student awareness regarding effects and side effects of drugs. Our findings suggest that educating students about the adverse effects as well as the moral and religious implications of drug abuse is more likely to have a positive impact than increased policing. Proper student-counseling facilities and healthier avenues for recreation are also required.

Assessment of cerebral oxygenation during repeated squat stands following an acute sport-related concussion (SRC) has the potential to identify physiological changes following SRC. All varsity university athletes completed a pre-season assessment and 53 were followed up within 5-days of suffering an SRC. Of the 53 participants, 29 had continuous beat-to-beat blood pressure (BP; sampled at 200 hz) collected by finger photoplethysmography, and 53 had right prefrontal cortex oxygenation collected by near-infrared spectroscopy (NIRS; sampled at 10 hz). Participants completed a 5-min repeated squat (10 s) stand (10 s) manoeuvre (0.05 hz). Wavelet transformation was applied to the signals, separating them into smooth muscle cell (0.05 to 0.145 hz), respiratory (0.145 to 0.6 hz) and cardiac (0.6 to 2 hz) frequency intervals, with the 5-min squat stand manoeuvre compared from pre-season to post-concussion. A significant amplitude increase ( p  < 0.05) in oxyhaemoglobin, total haemoglobin and haemoglobin difference following SRC was found at the cardiac interval. During the squat stand dynamic cerebral autoregulation challenge, this exploratory study found an elevated contribution from the heart to the oxygenation response at the right prefrontal cortex, suggestive of a cardiac compensatory response during concussion. Future research with cerebral blood flow alongside NIRS can provide greater insight to dynamic cerebral autoregulation.

Background: Cardiovascular disease remains a significant global health concern, with high low-density lipoprotein cholesterol (LDL-C) levels contributing to an increased risk. Familial hypercholesterolemia (FH) further complicates its management, necessitating additional lipid-lowering therapies. Evinacumab, an angiopoietin-like protein 3 monoclonal antibody, has emerged as a potential treatment, particularly for patients with FH, by effectively reducing LDL-C and triglyceride levels. This meta-analysis aimed to evaluate the efficacy and safety of evinacumab across diverse patient populations., Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria, relevant randomized controlled trials (RCTs) were systematically retrieved from multiple databases until November 24, 2023. The inclusion criteria were studies comparing evinacumab (at doses of 5 and 15 mg) to placebo, with outcomes focusing on lipid levels and adverse events. Standardized protocols were employed for data extraction and quality assessment, and statistical analysis was conducted using RevMan software., Results: Four RCTs, involving 270 patients, were included in the analysis. The analysis revealed significant reductions in lipid markers, particularly with the 15-mg dose of evinacumab, including triacylglycerols (standard mean difference [SMD] = -6.09, 95% confidence interval [CI] - 14.53 to 2.36, P = 0.16), total cholesterol (SMD = - 6.20, 95% CI - 11.53 to - 0.88, P = 0.02), high-density lipoprotein cholesterol (SMD = - 0.79, 95% CI - 1.27 to - 0.31, P = 0.001), LDL-C (SMD = - 4.58, 95% CI - 9.13 to - 0.03, P = 0.05), apolipoprotein (Apo) B (SMD = - 4.01, 95% CI - 7.53 to - 0.46, P = 0.03), and Apo C3 (SMD = - 7.67, 95% CI - 12.94 to - 2.41, P = 0.004). Adverse event analysis revealed no significant association, indicating good tolerability., Conclusion: High-dose evinacumab (15 mg) consistently demonstrated efficacy in reducing cholesterol and other lipid markers, with favorable tolerability. Further research is warranted to comprehensively assess its safety and clinical effectiveness, emphasizing the need for additional data to support its use in managing cardiovascular disease., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

There is still much uncertainty surrounding the approach to diagnosing and managing a sport-related concussion (SRC). Neurobiological recovery may extend beyond clinical recovery following SRC, highlighting the need for objective physiological parameters to guide diagnosis and management. With an increased understanding of the connection between the heart and the brain, the utility of assessing cardiovascular functioning following SRC has gained attention. As such, this review focuses on the assessment of cardiovascular parameters in the context of SRC. Although conflicting results have been reported, decreased heart rate variability, blood pressure variability, and systolic (ejection) time, in addition to increased spontaneous baroreflex sensitivity and magnitude of atrial contraction have been shown in acute SRC. We propose that these findings result from the neurometabolic cascade triggered by a concussion and represent alterations in myocardial calcium handling, autonomic dysfunction, and an exaggerated compensatory response that attempts to maintain homeostasis following a SRC. Assessment of the cardiovascular system has the potential to assist in diagnosing and managing SRC, contributing to a more comprehensive and multimodal assessment strategy., Competing Interests: Declaration of competing interest The authors declare that they do not have any conflicts of interest, financial or otherwise, that may have influenced this work., (Copyright © 2024. Published by Elsevier B.V.)

Sport-related concussion (SRC) is known to disrupt neurohemodynamic activity, cardiac function, and blood pressure (BP) autoregulation. This study aims to observe changes in cerebrovascular and cardiovascular responses during controlled respiration after sustaining an SRC. University varsity athletes ( n = 81) completed a preseason physiological assessment and were followed up within 5 days of sustaining an SRC. During preseason and follow-up assessments, participants' continuous beat-to-beat BP was collected by finger photoplethysmography, and right prefrontal cortex oxygenation was collected using near-infrared spectroscopy (NIRS). Participants completed 5 min of seated rest and 5 min of a 6-breaths per minute controlled breathing protocol (5 s inhale and 5 s exhale; 0.10 Hz). Wavelet transformation was applied to the NIRS and BP signals, separating them into respiratory (0.10-0.6 Hz) and cardiac (0.6-2 Hz) frequency intervals. Of the 81 participants, 74 had a usable BP signal, 43 had usable NIRS signals, and 28 had both usable BP and NIRS signals. Wavelet amplitudes were calculated and coherence between NIRS and BP on the 28 participants were assessed. There was a significant ( P < 0.05) decrease in oxygenated hemoglobin amplitude from 0.062 to 0.054 Hz and hemoglobin difference amplitude from 0.059 to 0.051 Hz, both at the respiratory (0.10-0.6 Hz) frequency interval, from preseason to acute SRC, respectively. Therefore, during controlled respiration, there was a reduction in intensity at the respiratory band, suggesting a protective, reduced respiratory contribution to cerebral hemodynamic activity following acute SRC. NEW & NOTEWORTHY This study investigated cerebral hemodynamic activity following sport-related concussion. Prefrontal cortex oxygenation was assessed by near-infrared spectroscopy (NIRS) during a controlled breathing protocol. Wavelet transformation of the NIRS signals showed significant decreases in HbO 2 and HbD amplitude at the respiratory frequency interval (0.10-0.6 HZ) from preseason baseline to acute concussion. These results suggest a decreased respiratory contribution to cerebral hemodynamic activity following acute concussion.

The growing incidence of Parkinson's Disease (PD) is a major burden on the healthcare system. PD is caused by the degeneration of dopaminergic neurons and is known for its effects on motor function and sleep. Sleep is vital for maintaining proper homeostasis and clearing the brain of metabolic waste. Adequate time spent in each sleep stage can help maintain homeostatic function; however, patients with PD appear to exhibit sleep impairments. Although medications enhance the function of remaining dopaminergic neurons and reduce motor symptoms, their potential to improve sleep is still under question. Recently, research has shifted towards exercise protocols to help improve sleep in patients with PD. This review aims to provide an overview of how sleep is impaired in patients with PD, such as experiencing a reduction in time spent in slow-wave sleep, and how exercise can help restore normal sleep function. A PubMed search summarized the relevant research on the effects of aerobic and resistance exercise on sleep in patients with PD. Both high and low-intensity aerobic and resistance exercises, along with exercises related to balance and coordination, have been shown to improve some aspects of sleep. Neurochemically, sleeping leads to an increase in toxin clearance, including α-synuclein. Furthermore, exercise appears to enhance the concentration of brain-derived neurotrophic factors, which has preliminary evidence to suggest correlations to time spent in slow-wave sleep. More research is needed to further elucidate the physiological mechanism pertaining to sleep and exercise in patients with PD., (© 2024. The Author(s).)

Heart rate variability (HRV), systolic blood pressure variability (BPV), and spontaneous baroreflex sensitivity (BRS) are indirect and approximate measures of autonomic regulation of the cardiovascular system. Studies have shown differences in HRV and BRS between males and females; however, no study has observed differences in BPV, HRV, or BRS between male and female athletes. One hundred males (age 21.2 ± 2.1 y; BMI 27.4 ± 4.5 kg/m 2 ) and sixty-five females (age: 19.7 ± 1.6 y; BMI 22.7 ± 2.2 kg/m 2 ) were assessed during the pre-season baseline. We collected resting beat-to-beat blood pressure and R-R intervals using finger photoplethysmography and a 3-lead electrocardiogram, respectively. Participants underwent a controlled slow breathing protocol (six breaths/minute: 5 s inhale, 5 s exhale) for 5 min. Spectral and linear analysis was conducted on blood pressure and ECG data. Regression curves were fitted to the blood pressure and R-R signals, with the slopes providing the BRS parameters. Male athletes had significantly ( p < 0.05) lower mean heart rate, RR interval SD2/SD1, HRV % low-frequency, and higher BP high-frequency power during controlled respiration. No differences were found in any BRS parameters. HRV and BPV responses to a slow breathing protocol differed between male and female athletes; however, BRS responses did not.

Objective: To determine the incidence of surgical site infection following open hernioplasty, and to compare the infection rate among ventral and groin hernia repairs., Method: The retrospective study was conducted from April 2 to November 30, 2021, at the Government Tehsil Headquarter Hospital Sabzazar, Lahore, Pakistan, and comprised data form June 2018 to December 2020 of patients with ventral abdominal and groin hernia. All patients underwent hernioplasty by a single consultant surgeon and were discharged within 2 days of surgery. Surgical-site infections were recorded on follow-up visits up to 30 days of operation, and were compared between ventral and groin hernia cases. Data was analysed using SPSS 22., Results: Of the 218 patients with mean age 37.07±4.94 years, 117(53.67%) were males, 108(49.54%) smokers and 127(58.25%) hypertensive, while 110(50.45%) had ventral abdominal hernia and 108(49.54%) had groin hernias. Mean operative time and mean hospital stay were 56.53±6.20 minutes and 3.06±1.31days, respectively. Mean wound drainage in abdominal hernia cases was 8.99±2.02 days. Surgical site infection incidence following open hernioplasty was 2(0.91%). Infection rate among ventral abdominal and groin hernioplasty were 1(0.90%) and 1(0.92%) (p=0.50)., Conclusions: Incidence of surgical site infection following open hernioplasty showed no significant difference between ventral abdominal and groin hernia repairs.

Background: The emergence of the COVID-19 pandemic has affected the lives of many people, including medical students. The present study explored internet addiction and changes in sleep patterns among medical students during the pandemic and assessed the relationship between them., Methods: A cross-sectional study was carried out in seven countries, the Dominican Republic, Egypt, Guyana, India, Mexico, Pakistan, and Sudan, using a convenience sampling technique, an online survey comprising demographic details, information regarding COVID-19, the Pittsburgh Sleep Quality Index (PSQI), and the Internet Addiction Test (IAT)., Results: In total, 2749 participants completed the questionnaire. Of the total, 67.6% scored above 30 in the IAT, suggesting the presence of an Internet addiction, and 73.5% scored equal and above 5 in the PSQI, suggesting poor sleep quality. Internet addiction was found to be significant predictors of poor sleep quality, causing 13.2% of the variance in poor sleep quality. Participants who reported COVID-19 related symptoms had disturbed sleep and higher internet addiction levels when compared with those who did not. Participants who reported a diagnosis of COVID-19 reported poor sleep quality. Those living with a COVID-19 diagnosed patient reported higher internet addiction and worse sleep quality compared with those who did not have any COVID-19 patients in their surroundings., Conclusion: The results of this study suggest that internet addiction and poor sleep quality are two issues that require addressing amongst medical students. Medical training institutions should do their best to minimize their negative impact, particularly during the current COVID-19 pandemic., Competing Interests: The authors have declared that no competing interests exist.

Supraventricular tachycardia (SVT) is a tachyarrhythmia characterized by a heart rate above 120 beats per minute (BPM). Patients with SVT exhibit the following symptoms: palpitations, shortness of breath, chest pain, hemodynamic instability, or possibly asymptomatic. The increase in cardiac output and the increase in resting heart rate during pregnancy predispose pregnant women to SVT. The management of SVT in pregnancy, although remarkably similar, varies slightly based on the trimester of pregnancy. Atenolol and verapamil are effective methods of treating SVT, which can be used during the second and third trimesters. Both medications are contraindicated in the first trimester. At the same time, intravenous adenosine can be used in all three trimesters, including labor. Electrical cardioversion is an effective treatment method for hemodynamically unstable or drug-refractory patients, which has proven to be safe in all three trimesters, including labor but can result in pre-term labor in the third trimester. Non-fluoroscopic ablation proved to be the only treatment method that definitively resolved SVT without recurrence., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Ibetoh et al.)

Factor V deficiency is a rare bleeding disorder, which may be due to acquired inhibitors or biallelic mutations. Factor V deficiency due to homozygous or compound heterozygous mutation (also known as Owren's disease or parahemophilia) has an estimated prevalence of one in one million people. A 22-year-old female was admitted for evaluation of longstanding menorrhagia. Anatomic abnormalities were excluded, and prolonged prothrombin time (PT) and partial thromboplastin time (PTT) were identified. Mixing studies followed by specific factor assays and genetic testing enable identification of factor V deficiency, for which fresh frozen plasma (FFP) or factor V concentrates are therapeutic. Specific clotting factor assay followed by mixing studies and genetic studies is essential for the diagnosis of congenital factor V deficiency. Deranged PT and activated partial thromboplastin time (APTT) with normal factor I level must be evaluated for the disorder of clotting factors and must be managed by FFP administration or plasma-derived factor V concentrate wherever available., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Ehtisham et al.)

Introduction Vitiligo is an acquired pigmentary disorder of the skin and mucous membranes which is characterized by circumscribed depigmented macules and patches. Vitiligo is a progressive disorder in which some or all of the melanocytes in the affected skin are selectively destroyed. Around 0.5-2% of the world population is affected by vitiligo and the average age of onset is 20 years. The objective of the study was to evaluate the efficacy of tacrolimus versus clobetasol in the treatment of vitiligo. It is an open randomized control trial conducted in the Department of Dermatology, Nishtar Hospital, Multan for six months.  Methods One hundred sixty-two patients of vitiligo were included in the study. The disease was diagnosed on basis of clinical features and the Standard Assessment scale proposed by Hossain which was used to monitor and grade the response. Patients were randomly allocated into two groups by lottery method having 81 patients in each group. Group A was given tacrolimus whereas Group B was given clobetasol. Patients were followed up every four weeks. On the 12 th week of treatment, effectiveness was assessed by measuring the Assessment scale proposed by Hossain. The results of the two groups were then compared. Results Sixty-three patients (38.9%) were males whereas 99 patients (61.1%) were females. The mean age of the patients included in the study was 29.68 + 8.162 years. The mean weight of the patients was 62.25 + 9.529 Kg. Out of 162, treatment was effective in 89 patients (54.9%) whereas in 73 patients (45.1%) the treatment was ineffective. In Group A (tacrolimus), 42 patients (51.9%) had effective treatment (on the complete resolution of symptoms) whereas 39 patients (48.1 %) had ineffective treatment. In Group B (clobetasol), 47 patients (58%) had effective treatment, and the rest (34, 42%) had ineffective treatment. A Chi-Square test was applied to compare the efficacy of the two groups. There was no statistically significant difference in both the groups in terms of efficacy. Group B was numerically superior in terms of effective treatment (47 versus 42) but not superior statistically. Conclusion Comparison of tacrolimus and clobetasol in patients of vitiligo showed no significant difference in the efficacy of the two groups. It can be concluded that tacrolimus may be considered superior to corticosteroids as its local and systemic adverse effects are less., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2020, Mumtaz et al.)

The prevalence of dementia is around 5% worldwide in people above 65 years, which increases with aging. Alzheimer's disease is the most common cause of dementia in the elderly. On the other hand, anemia is considered one of the most prevalent comorbidities in the elderly with a prevalence of 11% in those above the age of 65. It is crucial that we find the association between anemia and dementia, as this linkage can prove beneficial. Many currently conducted studies support the idea that anemia is a significant risk factor for dementia. However, some studies still consider anemia and dementia as just an aging process, nothing more. In our study, we found that there are a lot of theories, such as low brain hemoglobin associated with low oxygen levels, which leads to neuron damage. One article mentioned that it is dependent on the level of hemoglobin as an effect with mild to moderate anemia, but apparent with severe forms of it. Researchers are expected to further explore and identify the exact relationship between anemia and dementia. We used the PubMed database as the principal source for data search and extracted articles exploring the relationship and role of anemia in decreasing the cognitive brain functions in the elderly. We reviewed 35 different articles, including clinical trials, review papers, randomized controlled trials (RCTs), and original research published between 2010 and 2020 to find commonly accepted pathophysiology that highlights how anemia causes a decrease in cognitive brain functions., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2020, Gattas et al.)

The most famous pacemaking activity found in the human body is in the cardiac system. However, pacemaking is also widely present in the nervous system. The ion channels responsible for the pacemaking activity are called hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels. HCN channels are activated during hyperpolarization and create an inward current named I h containing mixed sodium and potassium ions. The molecular mechanism of these unique features remains mysterious. In the peripheral nervous system (PNS), pacemaking is unique because it is only present in pathologic states when nerve damage occurs and leads to neuropathic pain. For this reason, pacemaking in neuropathic pain is also known as ectopic discharge. In our literature review, the HCN channel physiology is one of the research interests. We will present studies exploring the molecular mechanisms involved in HCN gating and ion permeability. The second research question is, what makes the pacemaking activity unique in the PNS? Thus, our paper will include studies that discuss the role of HCN channels in neuropathic pain. Given the fundamental role of HCN channels in regulating neuronal cells' discharge activity, the modulation of their function for therapeutic purposes could be useful in various pathological conditions. Here we review the present knowledge of the efficacy of HCN blocker treating neuropathic pain in humans., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2020, Liu et al.)

Diabetes is a common disease, and the number of patients is increasing every year. We report a case of a 34-year-old man with a history of diabetes mellitus (diagnosed at eight years old) and was on treatment with tablet glimepride with poor compliance. The patient sought consultation due to vomiting and abdominal pain 12 hours after onset along with burning micturition for four days. His initial blood sugar random (BSR) level was 84 mg/dL. Further lab tests revealed pH: 7.14, bicarbonate: 6.4 mEq/dL, sodium: 141, potasium: 3.8, chloride: 107, PO2: 115, PCO2: 19.4, serum amylase: 51, base excess (BE): -21.3 mmol/L, and positive ketonemia, i.e. 1.39. He was reanimated with parenteral crystalloids and insulin infusion. Eventually with subsequent arterial blood gases (ABGs) and ketones, the patient got better and was eventually declared to be out of diabetic ketoacidosis (DKA) and later discharged. There are very less studies done on euglycemic DKA (eu-DKA); so many physicians fail to diagnose the patients properly and they fall into the invisible cases chunk., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2020, Mumtaz et al.)

In direct adaptive inverse control (DAIC), parameters of the controller are estimated directly in the feed-forward loop. In this paper, we propose a closed loop direct adaptive inverse control (CDAIC) scheme which improves tracking, error convergence, and disturbance rejection properties of DAIC. CDAIC is applicable to stable or stabilized, minimum or nonminimum phase linear plants. CDAIC and DAIC are compared using computer simulations for disturbance free and disturbed discrete type nonminimum phase linear plants. CDAIC shows better results compared to DAIC in terms of mean square tracking error and disturbance rejection.

In this project, we strived to develop a decellularized human cornea to use as a scaffold for reconstructing the corneal epithelium and anterior stroma. Human cadaver corneas were decellularized by five different methods, including detergent- and nondetergent-based approaches. The success of each method on the removal of cells from the cornea was investigated. The structural integrity of decellularized corneas was compared with the native cornea by electron microscopy. The integrity of the basement membrane of the epithelium was analyzed by histology and by the expression of collagen type IV, laminin, and fibronectin. Finally, the ability of the decellularized corneas to support the growth of human corneal epithelial cells and fibroblasts was assessed in vitro. Corneas processed using Triton X-100, liquid nitrogen, and poly(ethylene glycol) resulted in incomplete removal of cellular material. Corneas processed with the use of sodium dodecyl sulfate (SDS) or with sodium chloride (NaCl) plus nucleases successfully removed all cellular material; however, only the NaCl plus nuclease treatment kept the epithelial basement membrane completely intact. Corneas processed with NaCl plus nuclease supported both fibroblast and epithelial cell growth in vitro, while corneas treated with SDS supported the growth of only fibroblasts and not epithelial cells. Decellularized human corneas provide a scaffold that can support the growth of corneal epithelial cells and stromal fibroblasts. This approach may be useful for reconstructing the anterior cornea and limbus using autologous cells.

Purpose: Limbal fibroblasts are known to regulate the maintenance and differentiation of the corneal epithelium including the limbal epithelial stem cells. This study examined the effect of limbal fibroblast conditioned media in a mouse model of limbal stem cell deficiency., Methods: Limbal stem cell deficiency was created in C57/Bl6 mice by performing a limbus to limbus epithelial debridement. The mice were treated topically for 3 weeks with conditioned media derived from human limbal fibroblasts. The control mice were treated with skin fibroblast conditioned media or Dulbecco's serum-free medium., Results: The mice treated with limbal fibroblast conditioned media demonstrated substantial growth of corneal type epithelial cells on the corneal surface with less conjunctival goblet cells. By contrast, the control treated corneas were found to be covered primarily by conjunctival type epithelium., Conclusions: Cell culture media conditioned by limbal fibroblasts appear to contain factor(s) that are therapeutically beneficial in a model of limbal stem cell deficiency. The current results further support the notion that the essential limbal stem cell niche is provided by limbal fibroblasts and suggest a new, non-invasive option in the treatment of limbal stem cell deficiency.