Myeloperoxidase (MPO) gene mutation in hereditary MPO deficiency

Myeloperoxidase (MPO), present in the azurophilic granules of polymorphonuclear leukocytes, is a myeloid enzyme whose synthesis is restricted to promyelocytes. Complete hereditary MPO deficiency affects 1 in 2,000 to 4,000 individuals; however, the genetic cause of this defect is unclear. We have determined the molecular basis of MPO deficiency in one individual (SQ). Granulocytes of SQ had no MPO activity, and had complete absence of mature and precursor MPO protein by Western blotting. Scanning MPO gene structure by Southern blotting detected a novel BgI II fragment in SQ; no other alteration in gross gene structure was detected. We hypothesized that a single base pair mutation formed a new BgI II restriction site, and that this occurred in exon 10 of MPO gene. As predicted, exon 10 from SQ was cleaved by BgI II, but DNA from the normal patients and five other MPO-deficient patients was not cleaved by this enzyme. Direct sequencing of the polymerase chain reaction (PCR) product of exon 10 showed a C to T substitution at codon 569 in exon 10, resulting in arginine (CGG) to tryptophan (TGG) substitution and creating a novel BgI II site. The mutation was homozygous, as shown by both sequencing and Southern blotting, and no other alterations in base sequence were detected. To determine the frequency of this mutation, DNA was collected from 400 normal individuals, and the presence of the mutation was examined by digesting with BgI II after amplifying exon 10 by PCR. No other case with the novel BgI II site was detected, suggesting that this is not a restriction fragment length polymorphism. The rest of the coding region of the MPO gene was sequenced in DNA from SQ, as well as from the five other MPO-deficient individuals and one normal person; no other mutations were found. Our results suggest that a point mutation at codon 569 of MPO gene represents one molecular form of MPO deficiency.     

Intracerebral arteriovenous malformations: evaluation with selective MR angiography and venography

Magnetic resonance (MR) angiography and spin-echo methods were used to evaluate intracerebral arteriovenous malformations (AVMs) in 10 patients. Spin-echo images obtained with flow presaturation demonstrated the nidus of the AVM in all cases, but it was difficult to determine feeding vessels. These vessels were directly visualized with three-dimensional MR angiography; their presence could be indirectly determined by means of selective presaturation of individual vessels, which resulted in a marked decrease in signal within the portion of the AVM supplied by that vessel. Vascular supplies from the internal carotid artery and anterior, middle, or posterior cerebral arteries were detected in all cases, but in three large malformations it was not possible to demonstrate small feeding vessels. MR angiograms were also helpful for further defining the nidus. The combination of MR angiographic and spin-echo methods provides information useful for therapeutic planning not provided by either technique alone.     

Isolation of macrophages (Hofbauer cells) from human term placenta and their prostaglandin E2 and thromboxane production

Placental macrophages (Hofbauer cells) are located close to trophoblast cells and fetal capillaries, which makes them ideal candidates for involvement in regulatory processes within the villous core. Their production of various cytokines and prostaglandin (PG) synthesizing enzymes has previously been shown immunohistochemically. Hofbauer cells were isolated from human placenta after term deliveries by Ficoll and Percoll gradient centrifugation. Remaining trophoblast cells were removed with anti-epidermal growth factor (EGF)-receptor-coated Dynabeads followed by differential adherence. The identity of isolated cells was investigated by immunohistochemistry with anti-CD68, which showed that >90% cells were positive. After a 36 h recovery period in either 20% O2 or 5% O2, fresh medium was applied and PGE2 and thromboxane (TXA2) production analysed by enzyme immunoassay at 4, 8, and 24 h. PGE2 and TXA2 were both produced by placental macrophages with PGE2 synthesis being predominant. Concentrations of both could be stimulated by lipopolysaccharide with maximum effect after 24 h. Culture in low oxygen caused decreased PGE2 concentrations, whereas TXA2 production remained unchanged. In conclusion, the presented isolation protocol allows further study of Hofbauer cell function. This study also presents novel findings regarding the prostaglandin production of term Hofbauer cells under normal and hypoxic conditions.      

硬膜外注射一定量液体冲击治疗腰椎术后近期疼痛26例

0　引言　我科近年来 ,对腰椎手术后近期出现疼痛患者 ,行硬膜外注射大容量等渗盐水 ,利多卡因及地塞米松治疗 ,取得良好效果 .1　对象和方法1.1　对象　患者 2 6 (男 2 2 ,女 4)例 ,年龄 38～ 5 2岁 . 2 5例术前诊断为椎间盘突出症 ,行椎间盘摘除术 ,1例为椎管狭窄 ,行椎管减压术 . 2 1例术后 7d左右出现术前症状 ,并逐渐加重 ,其疼痛症状超过术前 ,经 X线检查未见特殊病变 . 4例术后 10 d以上出现术前症状 ,但症状比术前略有改善 ,X线检收稿日期 :2 0 0 0 -0 5 -31;　修回日期 :2 0 0 0 -0 8-2 6作者简介 :张捍平 (196 4-) ,男 (汉族 ) ,…     

In vivo validation of reconstruction-based resolution recovery for human brain studies

The aim of this study was to validate in vivo the accuracy of a reconstruction-based partial volume correction (PVC), which takes into account the point spread function of the imaging system. The NEMA NU2 Image Quality phantom and five healthy volunteers (using [¹¹C]flumazenil) were scanned on both HR+ and high-resolution research tomograph (HRRT) scanners. HR+ data were reconstructed using normalization and attenuation-weighted ordered subsets expectation maximization (NAW-OSEM) and a PVC algorithm (PVC-NAW-OSEM). HRRT data were reconstructed using 3D ordinary Poisson OSEM (OP-OSEM) and a PVC algorithm (PVC-OP-OSEM). For clinical studies, parametric volume of distribution (V_T) images were generated. For phantom data, good recovery was found for both OP-OSEM (0.84 to 0.97) and PVC-OP-OSEM (0.91 to 0.98) HRRT reconstructions. In addition, for the HR+, good recovery was found for PVC-NAW-OSEM (0.84 to 0.94), corresponding well with OP-OSEM. Finally, for clinical data, good correspondence was found between PVC-NAW-OSEM and OP-OSEM-derived V_T values (slope: 1.02±0.08). This study showed that HR+ image resolution using PVC-NAW-OSEM was comparable to that of the HRRT scanner. As the HRRT has a higher intrinsic resolution, this agreement validates reconstruction-based PVC as a means of improving the spatial resolution of the HR+ scanner and thereby improving the quantitative accuracy of positron emission tomography.     

Molecular strain typing of Wolbachia infection from Indian mosquitoes using wsp gene

ObjectiveTo determine the status of Wolbachia subgroup and phylogenetic relationships in Indian mosquitoes.MethodsRecently we reported Wolbachia infection in eight out of twenty field-caught mosquito species of India, using wsp specific primers. DNA extracted from these mosquito species were used for PCR amplification and sequencing.ResultsWolbachia A harboured in Aedes albopictus and Culex gelidus belongs to the subgroup AlbA whereas Wolbachia B harboured in Aedes albopictus and Culex quinquefasciatus belongs to the subgroup Pip and of Culex vishnui belongs to subgroup Con. However, Wolbachia harboured in Armigeres subalbatus, Armigeres kesseli, Culex sitiens and Toxorhynchites splendens could not be placed into any known subgroup and may represent other unknown strains of Wolbachia. Our phylogenetic analysis revealed eight novel Wolbachia strains, four in the A group and four in the B group. Most of the Wolbachia strains present in Indian mosquitoes belong to the Albo, Pip and Con groups.ConclusionsThe similarities and differences between Wolbachia strains infecting different mosquito species are fundamental for estimating how easily mosquitoes acquire new infections.