Generating long‐lived CD8+ T‐cell memory: Insights from epigenetic programs

T‐cell‐based immunological memory has the potential to provide the host with life‐long protection against pathogen reexposure and thus offers tremendous promise for the design of vaccines targeting chronic infections or cancer. In order to exploit this potential in the design of new vaccines, it is necessary to understand how and when memory T cells acquire their poised effector potential, and moreover, how they maintain these properties during homeostatic proliferation. To gain insight into the persistent nature of memory T‐cell functions, investigators have turned their attention to epigenetic mechanisms. Recent efforts have revealed that many of the properties acquired among memory T cells are coupled to stable changes in DNA methylation and histone modifications. Furthermore, it has recently been reported that the delineating features among memory T cells subsets are also linked to distinct epigenetic events, such as permissive and repressive histone modifications and DNA methylation programs, providing exciting new hypotheses regarding their cellular ancestry. Here, we review recent studies focused on epigenetic programs acquired during effector and memory T‐cell differentiation and discuss how these data may shed new light on the developmental path for generating long‐lived CD8⁺ T‐cell memory.     

An Update on Retinopathy of Prematurity (ROP)

Retinopathy of prematurity (ROP) is a proliferative retinal vascular disease affecting the retina of premature infants. The clinical spectrum of ROP varies from spontaneous regression to bilateral retinal detachment and total blindness. Between these two extremes lies the form of ROP, which is amenable to treatment with laser photocoagulation, anti-vascular endothelial growth factor drugs or surgery. Increasing rates of preterm births coupled with better survival rates but lack of uniform quality of neonatal care and delays in diagnosis have led to increasing ROP blindness. Atypical forms of Aggressive Posterior ROP are seen in heavier birth weight babies in developing countries. Prevention of ROP by following stringent protocols for supplemental oxygen, prevention of sepsis, timely screening and laser treatment by a concerted and collaborative effort of neonatologists and ophthalmologists are required to fight the blindness from ROP.     

Morphological changes in the retinal pigment epithelium on spectral-domain OCT in the unaffected eyes with idiopathic central serous chorioretinopathy

Purpose To report the changes seen in the retinal pigment epithelium (RPE) morphology in the asymptomatic eyes of patients with idiopathic central serous chorioretinopathy (ICSC) using spectral-domain Cirrus ^TM high-definition optical coherence tomography (HD-OCT). Methods In a prospective case series, 17 consecutive patients with unilateral ICSC underwent spectral-domain Cirrus ^TM HD-OCT scans for both affected and opposite asymptomatic eye. Three-dimensional single-layer RPE map was studied in both eyes for morphological alterations, and findings were correlated with clinical presentation, fluorescein angiogram, and 5 Line raster scan. Additionally, three-dimensional (3D) single-layer RPE maps done in 111 healthy volunteers served as control. Results In patients with ICSC, 3D single-layer RPE analysis of asymptomatic eyes showed presence of RPE bumps in 16 (94%) eyes and pigment epithelium detachment (PED) in 2 (11.8%) eyes. The 5 Line raster scan was normal in all eyes. Of 222 normal (control) scans, 18 showed RPE bumps and none showed PED. Conclusions 3D single-layer RPE map showed abnormal pattern in the asymptomatic eyes of patients with unilateral ICSC. Summary Spectral-domain optical coherence tomography showed morphologic alterations in retinal pigment epithelium in both eyes of patients with idiopathic central serous chorioretinopathy.     

Oral myiasis caused by Musca domestica larvae in a child

Myiasis or infestation of living tissues by Diptera (two winged) fly larvae is primarily a problem of cattle and livestock in tropics. Human infestation is rare, occurs accidentally in persons at extremes of age, who are debilitated or not able to ensure basic hygiene and wound cleanliness. Necrotic tissue in wounds of whatever origin provides ideal substrate for the developing larvae. Depending upon the anatomic sites affected it presents clinically as cutaneous myiasis, myiasis of external orifices (oral, nasal, ocular, aural, anal, genital), and myiasis of internal organs (intestinal, urinary). Cutaneous myiasis is perhaps the most commonly reported entity. Species causing skin, subcutaneous and mucosal myiasis include Gastrophilus intestinalis (horse botfly), Hypoderma bovis (cattle botfly), and Dermatobia homonis (human botfly). Musca domestica, the common house fly, is a rare cause of myiasis despite its presence in abundance.This paper describes oral myiasis in a 16-year-old girl of hypotonic cerebral palsy. She had episodic fever, fetid breath, erythematous, tender and ulcerated swelling over anterior palate from which pus and maggots were coming out. She had lip incompetence and bad orodental hygiene. Radiologic and laboratory investigations revealed no abnormality. The maggots were removed manually and she was treated with orodental hygiene sessions, wound care, antibiotics and nutritional supplements. The larval specimens were identified as early instar of M. domestica. Prevention of human myiasis is important and involves control of fly population, general cleanliness, basic sanitation and health education with a special emphasis on oral health care in patients with special needs.     

Acanthosis nigricans: relation with type 2 diabetes mellitus, anthropometric variables, and body mass in Indians

Objective: To determine the prevalence of acanthosis nigricans (AN) in type 2 diabetes mellitus (T2DM) and its correlation with various anthropometric measurements in Indians. Methods: One hundred and fifty consecutive subjects with T2DM attending the diabetes clinic at a tertiary referral centre in North India were considered as cases and 150 age and sex matched healthy attendants of non-diabetic subjects as controls. All the cases and controls were screened for the presence of AN and its severity. Anthropometric measurements of all of them were measured in standard method. Regression analysis was done to determine the association of AN with T2DM and various anthropometric measurements. Results: The prevalence of AN in subjects with diabetes and healthy controls was 62.6% and 40% respectively, and this difference was significant (p<0.05). Body mass index (BMI) between cases and controls was comparable by chance. There was a statistically significant correlation of increasing severity of AN with increasing BMI, waist circumference, hip circumference, waist-hip ratio, skinfold thickness, and body fat percentage in diabetic patients. However, in regression analysis after considering all the confounding factors there was a significant correlation of AN, only with diabetes mellitus and BMI. Conclusions: Indians have high prevalence of AN and it is an independent cutaneous marker of both T2DM and BMI.     

First trimester bleeding evaluation

First trimester bleeding is a common presentation in the emergency room. Ultrasound evaluation of patients with first trimester bleeding is the mainstay of the examination. The important causes of first trimester bleeding include spontaneous abortion, ectopic pregnancy, and gestational trophoblastic disease; 50% to 70% of spontaneous abortions are due to genetic abnormalities. In normal pregnancy, the serum beta hCG doubles or increases by at least 66% in 48 hours. The intrauterine GS should be visualized by TVUS with beta hCG levels between 1000 to 2000 mIU/mL IRP. Visualization of the yolk sac within the gestational sac is definitive evidence of intrauterine pregnancy. Embryonic cardiac activity can be identified with CRL of >5 mm. A GS with a mean sac diameter (MSD) of 8 mm or more without a yolk sac and a GS with an MSD of 16 mm or more without an embryo, are important predictors of a nonviable gestation. A GS with a mean sac diameter of 16 mm or more (TVUS) without an embryo is a sonographic sign of anembryonic gestation. A difference of <5 mm between the mean sac diameter and the CRL carries an 80% risk of spontaneous abortion. Approximately 20% of women with first trimester bleeding have a subchorionic hematoma. The presence of an extra ovarian adnexal mass is the most common sonographic finding in ectopic pregnancy. Other findings include the tubal ring sign and hemorrhage. About 26% of ectopic pregnancies have normal pelvic sonograms on TVUS. Complete hydatidiform mole presents with a complex intrauterine mass with multiple anechoic areas of varying sizes (Snowstorm appearance). Twenty-five percent to 65% of molar pregnancies have associated theca-leutin cysts. Arteriovenous malformation of the uterus is a rare but life-threatening cause of vaginal bleeding in the first trimester. The sonographic findings in a patient with first trimester bleeding should be correlated with serum beta hCG levels to arrive at an appropriate clinical diagnosis.     

中频交变磁场照射后小鼠的行为学变化

目的:目前电磁辐射对生物体行为学方面的研究还很薄弱,设立不同磁场的强度和不同照射的周期,观察中频领域磁场照射对小鼠的自主活动和学习记忆的影响。方法:实验于2007-05-10/06-15在清华大学医学院和中国医学科学院药用植物研究所完成。①实验材料:磁场发生装置:中频交变磁场发生装置由清华大学工程物理系医学物理与工程研究所自主研发,可产生频率为40kHz,场强为28.8A/m,28.8kA/m的中频交变磁场。自主活动测试箱:中国医学科学院药用植物研究所提供,为一可封闭的金属箱,内置摄像头。4只黑色塑料测试桶分别置于箱子四角。水迷宫测试箱:中国医学科学院药用植物研究所提供。②实验动物及方法:将80只小鼠随机分为不同场强照射组和对照组。强磁场照射1组:11.6kA/m/40kHz,1h/d,连续照射7d。强磁场照射2组:11.6kA/m/40kHz,2h/d,连续照射7d。强磁场照射3组:11.6kA/m/40kHz,2h/d连续照射15d。弱磁场照射组:28.8kA/m/40kHz,2h/d,连续照射7d。对照组除了未放入磁场照射,其他条件与照射组一致。实验过程中对动物处置符合动物伦理学要求。③实验评估:观察其一般活动的改变,并采用自主活动测试箱和水迷宫测试箱进行测试,观察各组小鼠的自主活动和学习记忆的改变。结果:①一般行为观察:与对照组小鼠对比,经过中频交变磁场照射过的各组小鼠活跃度减低,毛色较差。强磁场照射3组(145G,2h/d,连续15d)于第11天和13天分别死亡1只。②自主活动检测结果:强磁场照射2,3组小鼠的运动路程、运动速度、运动时间明显低于对照组(P<0.05)。③水迷宫测试结果:在学习记忆检测阶段撤掉平台,发现各组动物2min内穿越平台原来所在象限的次数没有明显差别(P>0.05)。结论:中频交变磁场照射会给小鼠的自发活动造成一定影响,对学习记忆没有影响。