Respiratory Studies in an Infant with Neonatal Myasthenia Gravis

Hutchison, A. A. and Russell, G. (1979). Aust. Paediatr. J , 15, 44–46. Respiratory studies in an infant with neonatal myasthenia gravis. Respiratory mechanics were measured in an infant with neonatal myasthenia gravis at the age of six and fourteen days. At the age of six days, but not at the age of fourteen days, an intravenous injection of edrophonium chloride brought about an increase in ventilation and in all components of respiratory work.     

EFFECTIVE PULMONARY CAPILLARY BLOOD FLOW IN INFANTS WITH BIRTH ASPHYXIA

ABSTRACT. Effective pulmonary capillary blood flow was measured on the first day of life in twenty term infants with birth asphyxia and twenty-five normal term infants. The infants studied showed no clinical or laboratory evidence of respiratory distress. The mean effective pulmonary capillary blood flow of 121 ml/kg/min in the birth asphyxia group was significantly lower than the mean of 162 ml/kg/min in the normal group. The possible relationship of birth asphyxia and pulmonary hypoperfusion in the aetiology of the idiopathic respiratory distress syndrome is discussed.     

Glomerular paramesangial deposits: association with hypocomplementemia in membranoproliferative glomerulonephritis types I and III

Of 22 subjects previously reported with some form of factor H dysfunction, 12 had a glomerulonephritis that appeared to not be of immune complex origin. Factor H dysfunction results in elevated circulating levels of the C3b-dependent C3 convertase, C3b,Bb. Of the 12 cases with glomerulonephritis, the glomerular deposits in the six whose biopsy specimens were studied were predominately subepithelial on the paramesangial portion of the glomerular basement membrane. In a subsequent study, similar deposits were found in patients with membranoproliferative glomerulonephritis (MPGN) type II, also a nephritis that is probably not of immune complex origin. Paramesangial deposits were found in these patients only in biopsy specimens obtained when the C3 level was low, at which time convertase stabilized by nephritic factor would be present in the circulation. This association of paramesangial deposits with circulating convertase was further tested by correlating these deposits with the level of C3 at the time of biopsy in MPGN types I and III. The results in type III MPGN were similar to those in type II; paramesangial deposits were frequently present when the C3 level was low as a result of circulating nephritic factor of the terminal pathway, NFt, and were usually absent when the C3 level was in the upper two thirds of the normal range. Deposits persisted in those patients with C3 levels that had been low but that had increased during the year before biopsy to within the lower one third of the normal range. The persistence of paramesangial deposits in MPGN type III, as compared with MPGN type II, may be related to the differences in composition and function of the two NF stabilized convertases (C3bn,Bb,P,NFt and C3b,Bb,NFa, respectively) that circulate in these two disorders. In contrast to MPGN type III, the hypocomplementemia in MPGN type I is thought to be, for the most part, the result of classical pathway activation, which is not associated with elevated circulating convertase levels. In agreement with this, paramesangial deposits were found in only two of 34 biopsy specimens. At the time of those two biopsies, both patients had a complement profile indicating that the NFt was circulating, as in MPGN type III. In three other cases with profiles compatible with circulating NFt, paramesangial deposits were not found. In all patients with type I MPGN, electron microscopy and immunofluorescence of the glomeruli gave results typical of an immune complex nephritis. Thus, even though the complement profile in MPGN type I may at times indicate the presence of a nephritic factor, circulating immune complexes appear to be basic to pathogenesis. The observations support the hypothesis that elevated levels of the C3b-dependent convertase, as found in the "experiments of nature" with factor H dysfunction and in MPGN types II and III, are associated with paramesangial deposits. The nature of this association and the role of these deposits in producing the nephritis is not clear.     

Central Nervous System Toxicity of Manganese: I. Inhibition of Spontaneous Motor Activity in Rats after Intrathecal Administration of Manganese Chloride

The intrathecal administration of MnCl₂ to young male rats causeddoparnine depletion in the caudate-putamen and a decrease inspontaneous motor activity. Our experiments demonstrate thatin the young rat: (a) the lateral choroid plexus protects thecerebrospinal fluid (CSF) from high concentrations of Mn inthe blood by sequestering and thus preventing large amountsof this metal ion from entering the CSF. As blood Mn levelsrise, the lateral choroid plexus may become overwhelmed andleak an increasing amount of Mn into the CSF. (b) The lateralchoroid plexus does not remove Mn²⁺ from the CSF. (c) The injectionof MnCl² into the CSF of rats caused a rapid decrease in spontaneousmotor activity which is dose-dependent and reversible underthe present experimental conditions. Entrathecal Mn resultsin a substantial decrease in striatal dopamine but not homovanillicacid or 3,4-dihydroxyphenylacetic acid (DOPAC) concentrationsand is associated with an increase in the Mn concentration ofthe substantia nigra and caudate-putamen.     

THE EFFECT OF EXERCISE ON ANKYLOSING SPONDYLITIS -- A PRELIMINARY STUDY

The Polhemus Navigation Sciences 3Space Isotrak system was usedto measure the range of lumbar spinal motion of 57 patientswith ankylosing spondylitis. Forty-three of these attended voluntaryexercise sessions for an average of one and a half hours perweek while 14 did not participate in any formal exercise groups.Exercising patients fell into two groups: those attending moderateand those attending vigorous exercise sessions. Results forexercising patients obtained immediately pre- and post- a singleexercise session showed a small but significant increase inextension for the vigorous exercise group but no significantchanges in any other movement for either of the groups. In agroup of 44 patients (33 exercising, 11 non-exercising) whowere followed-up over a 2 to 6 month period, slight loss offlexion (5.5°) and lateral bend (3°) was observed butthere was no change in range of extension. KEY WORDS: Exercise, Ankylosing spondylitis, Range of motion, isotrak     

Protein‐energy malnutrition during early childhood and periodontal disease in the permanent dentition of Haitian adolescents aged 12–19 years: a retrospective cohort study

International Journal of Paediatric Dentistry 2010; 20: 222–229 Objectives. The aim of this retrospective cohort study was to examine whether exposure to early childhood protein‐energy malnutrition (ECPEM) is related to worsened periodontal status in the permanent dentition during adolescence. Design. A trained clinician/researcher examined the periodontal status of 96 persons aged 12–19 living in rural Haiti using WHO diagnostic criteria (Community Periodontal Index, WHO 1997). Malnutrition data of the study participants had been collected during the years 1988–1993 by a nongovernmental organization. We compared those who had been malnourished in early childhood, based on z‐scores for anthropomorphic data collected during the first 5 years of life, with those who had not been malnourished, regarding mean Community Periodontal Index (CPI) score, controlling for age, sex, socioeconomic status, and smoking. Results. Overall, 57.3% of the participants demonstrated a CPI score of 3 or greater in at least one sextant. ECPEM was independently and positively related to mean CPI score, when controlling for sex and smoking. Conclusions. More than half of these young Haitians demonstrated CPI scores of 3 or greater, and ECPEM was related to poorer periodontal status, as measured by CPI, in the permanent dentition.     

骨髓间质干细胞分泌胶质源性神经生长因子及对1-甲基4-苯基吡啶离子诱导PC12细胞凋亡的干预

目的:收集体外培养、纯化的骨髓间质干细胞条件培养液,检测其对多巴胺能神经元有保护作用的胶质源性神经生长因子分泌情况,并观察对1-甲基4-苯基吡啶离子诱导的PC12细胞凋亡的保护作用。方法:实验于2005-05/2006-10在中国医科大学附属一院神经内科实验室完成。①PC12细胞由协和医科大学细胞培养中心提供。1-甲基4-苯基吡啶离子(Sigma,USA,批号3707312)。②选取清洁级SD大鼠20只,麻醉后取股骨和胫骨,去净肌肉取骨髓,按1010L-1接种于含体积分数为0.2胎牛血清的低糖型DMEM培养基中,通过弃悬浮细胞及换液后可得到较纯的骨髓间质干细胞。培养第10天胰蛋白酶消化传代,当第2代细胞扩增至铺满瓶底80%时,改用含体积分数为0.05胎牛血清的低糖型DMEM条件培养液,48h后收集培养液,经超滤浓缩系统(截留分子量为10000)浓缩10倍后过滤除菌。③骨髓间充质干细胞接种于24孔板内,贴壁后多聚甲醛固定,磷酸盐缓冲液漂洗,免疫荧光法鉴定骨髓间充质干细胞表面抗原的表达。骨髓间充质干细胞消化后进行细胞计数,按1×108L-1接种于75cm培养瓶,加入含体积分数为0.2胎牛血清的DMEM培养液20mL,于培养第5,10天采用ELISA法测定细胞培养上清液中的胶质源性神经生长因子含量。④PC12细胞置于RPMI1640培养液中,内含体积分数为0.1的马血清和0.05的胎牛血清,汇集至80%时进行传代接种,液氮罐中贮存备用。实验前首先置换培养液,使血清浓度降至为仅含0.01马血清和0.01胎牛血清,24h后将培养的细胞分为4组:空白对照组,在细胞培养体系中不加入任何药物;骨髓间充质干细胞上清液组,接种后24h在细胞培养体系中分别加入骨髓间充质干细胞上清液30,60,120μL;1-甲基4-苯基吡啶离子组,接种后24h分别加入1-甲基4-苯基吡啶离子,使终浓度分别为100,200,400μmol/L;联合组,接种后24h加入200μmol/L1-甲基4-苯基吡啶离子,24h后再分别给予骨髓间充质干细胞上清液30,60,120μL。⑤各组细胞于给药后24,48h,流式细胞术检测PC12细胞的凋亡率;通过免疫细胞化学法和RT-PCR法检测PC12细胞半胱氨酸天冬氨酸蛋白酶3蛋白和mRNA的表达。结果:①骨髓间充质干细胞表面抗原鉴定:骨髓间充质干细胞可在体外分离扩增,其表面抗原CD45呈阴性,而CD44表达阳性。②骨髓间充质干细胞培养上清液中胶质源性神经生长因子水平检测:第5,10天培养上清液中的胶质源性神经生长因子浓度为(44.57±5.96)ng/L和(45.41±6.33)ng/L,差异无显著性意义(P>0.05)。③PC12细胞凋亡情况:联合组200μmol/L1-甲基4-苯基吡啶离子作用PC12细胞24h后,细胞凋亡率为(42.34±3.21)%;加入30,60,120μL骨髓间充质干细胞上清液处理24h后,细胞凋亡率分别降为(31.96±2.89)%,(17.89±1.78)%,(10.08±0.91)%,差异有显著性意义(P<0.05)。联合组药物作用48h与24h情况相似。④给药后各组半胱氨酸天冬氨酸蛋白酶3蛋白及mRNA的表达:联合组半胱氨酸天冬氨酸蛋白酶3蛋白和mRNA水平均明显低于1-甲基4-苯基吡啶离子组(t=0.05～0.32,P均<0.05)。结论:骨髓间充质干细胞能够分泌胶质源性神经生长因子,对1-甲基4-苯基吡啶离子诱导的PC12细胞凋亡产生保护作用。这种保护作用的强弱与其浓度有关,具体作用机制可能是通过抑制半胱氨酸天冬氨酸蛋白酶3蛋白和mRNA水平实现的。