Cloning and expression of the gene involved in Sanfilippo B syndrome (mucopolysaccharidosis III B)

Sanfilippo B syndrome is caused by a deficiency of alpha-N- acetylglucosaminidase, a lysosomal enzyme involved in the degradation of heparan sulphate. Accumulation of the substrate in lysosomes results in degeneration of the central nervous system with progressive dementia often combined with hyperactivity and aggressive behaviour. In order to clone the deficient gene, we purified the enzyme from human placenta and obtained amino acid sequence information. Alignment of one of the CNBr generated internal peptides to sequence from the database revealed the chromosomal location of the gene in the 5' upstream flanking region of the gene for 17-beta-hydroxysteroid-dehydrogenase at 17q21.1. The available DNA sequence was used to clone the cDNA coding for alpha-N- acetylglucosaminidase and analyse its gene structure. The gene is fully contained in the 5' upstream flanking region of the gene for 17-beta- hydroxysteroid-dehydrogenase and interrupted by five introns. The cDNA clone has a length of 2575 bp and encodes a protein of 743 amino acids. Chinese hamster ovary cells transfected with the cDNA construct show alpha-N-acetylglucosaminidase activity about 17-fold over background. This will allow correction studies with NAG deficient Sanfilippo B cell lines and facilitate the development of enzyme replacement therapy for these patients.      

Paramagnetic macrocyclic complexes as contrast agents for MR imaging: proton nuclear relaxation rate enhancement in aqueous solution and in rat tissues

Paramagnetic macrocyclic chelates show promise as magnetic resonance (MR) imaging contrast agents due to stability and relaxivity comparable to those of DTPA-type chelates. For the three copper and manganese macrocyclic complexes studied in aqueous solution, T1 and T2 relaxivities ranged from 0.14 to 5.88 mM-1sec-1 at 6.25 MHz. In rats, the intravenous administration of 16 mumol/kg of Mn(cyclam) caused the liver T1 relaxation rate to double at 15 minutes after injection. T1 measurements by pulsed MR imaging and manganese analyses on excised tissue showed that both relaxation rate (1/T1) and manganese content of liver and kidney increase linearly with the dosage of Mn(cyclam). The linear relationship between 1/T1 and manganese content can be considered an "in tissue" relaxivity plot for the agent. The resulting relaxivity is 54 mM-1sec-1 in liver, compared with 3.1 mM-1sec-1 in aqueous solution. Although this work is preliminary, the implication for medical MR imaging applications is that macrocyclic contrast agents can be effective at approximately one-tenth the current typical dose used for gadolinium DTPA.     

海南省大劣按蚊实验室自然交配的驯化研究

目的 建立实验室大劣按蚊自然交配繁殖种群,为同类研究提供依据。方法 将野外捕捉并在实验室人工交配繁殖至第61代的大劣按蚊,按不同雌雄比例先后顺序置于大、中、小三种不同型号的蚊笼中喂养、驯化、观察产卵情况并计算产卵数和孵化率。结果 在大、中、小蚊笼内的分别驯化至第15、10和18代时成蚊卵的孵化率各达到82％、83．4％和80．7％,成功建立小蚊笼自然交配的大劣按蚊种群。结论 经实验室驯化的大劣按蚊能够自然交配、产卵、繁殖,有助于建立实验室自然种群。     

甲状腺机能亢进症危险因素病例对照研究

目的 探讨各危险因素与甲亢的关系。方法 对三亚地区110例甲亢采用1：2配比的病例对照研究,资料处理采用条件Logistic回归分析.结果 甲亢发病与下列5因素关系密切：家庭年收入(OR=2．055)、食用碘盐(OR=2．133)、喜食海产品(OR=2．183)、感染(OR=2．382)、家庭生活事件(OR=3．017) 结论 家庭生活事件、感染、喜食海产品、食用碘盐、家庭年收入增高等是甲亢的危险因素。     

海南省性罪错妇女11年性病感染情况调查分析

目的 通过对11年来性罪错人员性病感染情况的调查分析,掌握性病在性罪错妇女中流行的特点,为政府部门对性病防治政策的制定提供科学依据。方法 对1990年元月至2000年12月海南省妇女收容教育所被收教的性罪错妇女进行性病检查,统计其各种性病的发病人数,然后进行分析。结果 11年中共收教4780人,其中感染淋病、非淋菌性尿道炎(宫颈炎)、尖锐湿疣、梅毒、生殖器疱疹、HIV共2967例,阳性率为62．07％,其中非淋菌性尿道炎(宫颈炎)1826例(38．20％)、淋病469例(9、81％)、梅毒414例(8．7％)、尖锐湿疣246例(5．14％)、生殖器疱疹11例(0．23％)、HIV阳性1例(0．02%)。结论 性罪错妇女六种性病的患病率很高,达62．07％,其中非淋菌性尿道炎(宫颈炎)为其主要病种,淋病的患病率逐年下降,梅毒的患病率逐年上升,尖锐湿疣基本稳定,其流行特点值得我们重视。     

Quality of dictated feedback associated with SIMPL operative assessments of pediatric surgical trainees

BackgroundSIMPL is a workplace-based operative performance assessment tool which allows for dictated feedback (DF). To better understand the value of DF, we sought to characterize the type and quality of DF generated during SIMPL evaluations.MethodsThematic analysis of DF from SIMPL assessments between June 2017 and December 2018 at a single pediatric surgery fellowship program was performed. Comments were categorized as specific, encouraging or corrective. Categories were combined to determine DF quality as effective, mediocre or ineffective.ResultsOf 781 SIMPL assessments (21 faculty, 5 trainees), 451 (57%) had DF. Most comments were encouraging (93%) and specific (65%). Only 21% were corrective, 17% had entrustment features, and 8% had an explicit learning plan. Feedback quality was deemed mediocre (45%), ineffective (33%) and effective (21%).ConclusionSIMPL dictated feedback was mostly encouraging and specific. To improve quality, feedback should incorporate learning plans as well as corrective and entrustment features.     

Early nephrectomy in neonates with symptomatic autosomal recessive polycystic kidney disease

IntroductionAutosomal recessive polycystic kidney disease (ARPKD) is a rare cause of renal failure with a highly variable clinical course. Patients who are symptomatic early in life frequently require early nephrectomy and peritoneal dialysis. In these patients there are little data to guide clinicians on whether to select unilateral nephrectomy or bilateral nephrectomy at the initial operative intervention. We review our experience with this disease process.MethodsA retrospective review was performed of 11 patients at our institution with ARPKD symptomatic within the first month of life. Charts were reviewed for relevant clinical data, and patients were divided into groups based on undergoing either unilateral or bilateral nephrectomy at their initial intervention. The decision for unilateral versus bilateral nephrectomy was decided by the clinical team without any available guidelines.ResultsOf the 11 patients reviewed, two patients died within the first two weeks from other complications. The remaining 9 all required nephrectomy, with 5 undergoing synchronous bilateral nephrectomy, and 4 undergoing initial unilateral nephrectomy. All four patients required removal of their contralateral kidney, a median of 25.5 days later. There was no difference in mortality, ventilator free days, or time to full feeds between the two groups, although the group undergoing initial unilateral nephrectomy had more TPN days than their counterparts (28 vs 17 days, p = 0.014).ConclusionsIn our cohort, there were few significant differences between the groups based on choice of initial unilateral or bilateral nephrectomy, and all children ultimately required removal of both kidneys. These data suggest that anesthetic exposures and other clinical outcomes might be optimized by initial bilateral nephrectomy.Level of evidenceIII.