Effect of amrinone during group B Strepfococcus-induced pulmonary hypertension in piglets

Intravenous infusion of group B Streptococcus (GBS) into neonatal animals pro- duces pulmonary hypertension, ventilation/perfusion (V?_A/Q?) mismatch, and an increase in serum levels of thromboxane B₂, (TxB₂) and tumor necrosis factor (TNF)α. The vasodilator amrinone (amr) is a cGMP-inhibited phosphodiesterase inhibitor and is reported to inhibit thromboxane A₂ and TNF production. We hypothesized that infusion of amr would cause pulmonary vasodilation and reduce serum TxB₂, and TNF levels in piglets with late phase GBS-induced pulmonary hypertension. The effect of amr on gas exchange was also determined. A continuous infusion of GBS was administered for 5 hr to 4 groups of anesthetized, mechanically ventilated neonatal piglets. An amr bolus of 8 mg/kg was given at 4 hr followed by a 1 hr continuous infusion of either 10 or 20μg/kg/min of amr (amr 10 and amr 20, respectively). Control piglets received a bolus and 1 hr infusion of amr carrier. The infusion of amr, but not of carrier reversed late phase GBS- induced pulmonary hypertension. Piglets infused with amr 20 showed transient selective pulmo- nary vasodilation, based on a reduced ratio of pulmonary to systemic vascular resistance (PVW SVR ratio) value at 30min but not at 1 hr. compared to pre-amr treatment values. The PVR/SVR ratio values for amr 10 and control group did not change after treatment with either amr or carrier. Treatment with amr 10 or 20 did not decrease serum TxB₂, or TNF levels or increase VA/Q mismatch. A subsequent group of piglets received an 8 mg/kg bolus and 40 μg/kg/min infusion of amr (amr 40) to determine if the increased infusion rate would sustain a selective pulmonary vasodilatory effect beyond 30 min. The PVR/SVR ratio values for amr 40 did not change after treatment for 30 min or 1 hr, compared to pretreatment values. We conclude that amr is effective in reversing GBS-induced pulmonary hypertension. However, the reduction in SVR caused by amr may preclude its use in septic newborns. Pediatr Pulmonol. 1993; 16:303–310. © 1993 Wiley-Liss, Inc.     

银屑病患者外周血单一核细胞对链球菌M6蛋白的反应

目的 :探讨链球菌M6蛋白 (M 6P)在点滴型银屑病发病中的作用机制 .方法 :MTT法检测点滴型银屑病 (GP)、斑块型银屑病 (PP)患者及正常人外周血单一核细胞 (PBMC)对极微量 (10 0ng)M6P、葡萄球菌肠毒素B(staphylococcalen dotoxinB ,SEB)的增殖反应 ;双抗夹心ELISA法检测M6P刺激培养 72h点滴型银屑病PBMC上清中IFN γ,IL 4水平 .结果 :M6P可引起点滴型银屑病患者PBMC明显的增殖反应 ,与RPMI 16 4 0组 (空白对照 )差异非常显著 (P <0 .0 1) ;与斑块型组及正常对照组相比差异极显著 (P <0 .0 1) ;点滴型银屑病组M6P刺激 72h培养上清中IFN γ 含量较空白对照组明显升高 (P <0 .0 1) ,IL 4含量均未检出 .结论 :在点滴型银屑病的发病中 ,M 6P可能作为细菌超抗原刺激T细胞大量增殖后释放Th1型细胞因子而起作用     

新生儿肺炎链球菌苯唑西林耐药与pbp2B基因突变分析

目的了解新生儿肺炎链球茵（streptococcus pneumoniae，SP）青霉素耐药基因突变及体外苯唑西林耐药状况。方法对分离自新生儿呼吸道的20株肺炎链球茵用纸片扩散法（K—B法）进行青霉素耐药性试验。用套式聚合酶链反应（nPCR）扩增PbP2B基因，对PCR产物进行DNA测序。结果20株肺炎链球茵体外苯唑西林耐药，耐青霉素PbP2B基因突变为点突变，分A、B两类各占95％和5％。结论新生儿肺炎链球茵耐青霉素株pbp2B基因突变类型与DUPLESSIS等报道的不完全相同应引起高度重视。     

抗致龋病IgY的制备及防龋功能的观察

目的：制备具有高效免疫活性的抗致龋菌鸡卵黄免疫球蛋白（ＩｇＹ），评估其临床防龋功能。方法：以变形链球菌皮下注射免疫产蛋母鸡，采用聚乙二醇（ＰＥＧ）两步沉淀法提取ＩｇＹ，微量凝集试验检测ＩｇＹ免疫效价及交叉免疫特性，并观察其抑菌效果，与含氟漱口水比较其临床防龋功能。结果：作者制备的ＩｇＹ免疫效价为１：５１２，具有抑制变形链球菌生长，并与其他较常见的变形链球菌ｃ、ｅ、ｆ血清型结合发生交叉凝集反应，经临床验证结果表明ＩｇＹ漱口水与含氟漱口水龋患发生率相近。结论：抗变形链球菌鸡卵黄免疫球蛋白制剂具有防龋功能。     

11种充填垫底材料抑菌性能比较

目的：评价１１种牙科水门汀对牙髓卟啉菌、变形链球菌的抑菌作用。方法：细菌培养琼脂扩散法。结果：水门汀Ｃｅｒａｍｌｉｎ和ＣＯ－１对牙髓卟啉菌抑菌作用最强，其次是Ｄｙｃａｌ、Ｃａｌａｒ和Ｃａｒｂｃｈｅｍ；ＧＤ、ＶＬＣＣａｌａｒ、ＧＩ－１、ＺＯＥ和ＺＰＣ的作用较弱。在对变形链球菌作用中，Ｃａｌａｒ、ＣＯ－１最强，其次是ＺＯＥ、ＧＩ－１、ＺＰＣ、Ｄｙｃａｌ，其余的作用较弱。结论：１１种水门汀对牙髓卟啉菌、变形链球菌均有不同程度的抑菌作用，不同的材料对不同的细菌有不同的抑制作用     

NEONATAL SEPTICEMIA AND PERINATAL RISK FACTORS

Abstract. Many methods for screening and prediction of neonatal septicemia have been tried. In this study a score, related to both perinatal risk factors and neonatal diseases, was tested upon healthy newborn infants, infants with septicemia and infants with other diseases. Statistical differences were found between infants with neonatal septicemia and infants with other neonatal diseases as well as normal newborns. It was also possible to find a relationship between certain predisposing factors and predominance of certain pathogens. Complications during pregnancy and delivery were most often found in the group B streptococcal, combinations of invasive procedures and neonatal diseases in the staphylococcal group and surgical procedures in the gram-negative group.     

Management of Group B streptococcal sepsis risk in well, term newborns

Aim: To investigate how clinically well, term newborns at risk of early‐onset Group B streptococcal (EOGBS) disease are currently managed in the United Kingdom (UK). Methods: Review of guidelines of UK neonatal units. Results: One hundred and twenty‐five guidelines covering 157 neonatal units were received (71% of UK units), three of which were excluded from the review. We found great variation in every aspect for the management of EOGBS disease risk including the following: definition of risk factors; management of at‐risk newborns; choice of antibiotics. Conclusion: Our findings highlight the need for national consensus guidelines and clinical trials into the management of risk babies at risk of EOGBS disease.     

不典型急性链球菌感染后肾小球肾炎3例报告

目的提高对急性肾小球肾炎特殊临床和肾脏病理的认识。方法回顾性分析3例具有不典型急性肾小球肾炎临床表现患儿的临床和病理资料。结果 3例患儿均以急性肾小球肾炎表现起病,例1和例3在病程中出现肾病综合征表现;例2在6周后肉眼血尿方转为镜下血尿;例1于病程11周时仍为肾病水平蛋白尿、直至病程30周时尿蛋白消失;例2和例3分别于病程5周和4周恢复肾功能。例2和例3血清补体C3于病程6周内恢复,例1于病程11周恢复。例2和例3抗链球菌溶血素O(ASO)滴度增高。3例患儿的肾活检组织光镜和电镜改变均符合毛细血管内增生性肾小球肾炎的特点,免疫病理改变例1以IgM和C3沉积为主,例2和例3以C3沉积为主。结论上述3例患儿均诊断为急性链球菌感染后肾小球肾炎,但临床和病理特点具有不典型性。     

变异链球菌核糖-5-磷酸异构酶A的表达、纯化与鉴定

目的在大肠杆菌中高效表达变异链球菌核糖-5-磷酸异构酶A(ribose 5-phosphate isomerase A,rpiA),并对表达产物进行纯化和鉴定。方法根据GenBank中变异链球菌UA159株基因组rpiA的DNA编码序列,设计PCR引物,扩增变异链球菌核糖-5-磷酸异构酶A的DNA编码序列,将其克隆至pGEX-6p-1载体中,构建重组质粒,将测序正确的重组质粒转化入大肠杆菌BL21(DE3)中,用异丙基-β-D-硫代吡喃半乳糖苷(isopropylβ-D-1-thiogalactopyranoside,IPTG)诱导表达;对培养温度、IPTG用量、诱导时间等条件进行了优化;用亲和层析、离子交换层析纯化目标蛋白;用SDS-PAGE和质谱对目标蛋白进行鉴定。结果变异链球菌核糖-5-磷酸异构酶A在大肠杆菌中高效、可溶性表达,经质谱鉴定及SDS-PAGE分析,表达产物为变异链球菌核糖-5-磷酸异构酶A蛋白。经过纯化,得到纯度高达95%的变异链球菌核糖-5-磷酸异构酶A。结论成功地在大肠杆菌中高效表达了变异链球菌核糖-5-磷酸异构酶A蛋白,并建立了纯化工艺,得到高纯度的重组蛋白,为进一步研究变异链球菌属核糖-5-磷酸异构酶蛋白的生物学活性及功能奠定了基础。