Diagnosis of human immunodeficiency virus type 1 infection with different subtypes using rapid tests

We evaluated six rapid tests for their sensitivity and specificity in diagnosing human immunodeficiency virus type 1 (HIV-1) infection using 241 specimens (172 HIV-1 positive, 69 HIV-1 negative) representing different HIV-1 subtypes (A [n = 40], B [n = 47], C [n = 28], E [n = 42], and F [n = 7]). HIVCHEK, Multispot, RTD and SeroStrip were 100% sensitive and specific. Capillus failed to identify two of eight subtype C specimens (overall sensitivity of 98. 85%), while the SUDS test (the only test approved by the Food and Drug Administration) gave false-positive results for 5 of 69 seronegative specimens (specificity of 93.24%). Our results suggest that although rapid tests perform well in general, it may be prudent to evaluate a rapid test for sensitivity and specificity in a local population prior to its widespread use.     

Increased endostatin/collagen XVIII expression correlates with elevated VEGF level and poor prognosis in hepatocellular carcinoma.

Liver is the primary source for collagen XVIII, the precursor of angiogenesis inhibitor, endostatin. However, the role of endostatin/collagen XVIII expression during liver carcinogenesis remains elusive. Therefore, we studied its expression in five hepatoma cell lines and 105 hepatocellular carcinoma specimens. The poorly differentiated hepatoma cell lines exhibited increased endostatin/collagen XVIII levels compared with the well-differentiated ones. In hepatoma tissues, endostatin/collagen XVIII expression was detected in various types of liver cells and was significantly stronger in adjacent nontumor tissues than that in tumors (P<0.001). Endostatin/collagen XVIII expression in nontumor tissues correlated with tumor stages (P=0.014) and expression of vascular endothelial growth factor (P=0.007), but not the stages of hepatic fibrosis (P>0.05). Kaplan-Meier analysis showed that patients with higher endostatin/collagen XVIII expression had significantly shorter overall survival (P=0.011) and disease-free survival (P=0.0034). Moreover, endostatin/collagen XVIII level was an independent prognostic factor for tumor recurrence (P=0.034) by multivariate analysis. In conclusion, increased endostatin/collagen XVIII expression correlated with hepatoma progression and predicted poor prognosis for patients with hepatocellular carcinoma.     

Osteolytic potential of triphenyl bismuth as an alternative contrast medium in acrylic bone cement

Radiopaque cement containing barium sulfate causes significantly more bone resorption in vivo and in vitro than radiolucent cement. The aim of this study was to investigate the osteolytic potential of an alternative radiopaque agent, triphenyl bismuth (TPB). Bone cement particles containing various concentration of TPB (15 and 25 wt %) prepared by two methods, blending and dissolution, were added to monocytes in a bone resorption assay and the extent of lacunar resorption on dentine slices was determined. The results clearly show that cement particles containing TPB cause less bone resorption than cement particles containing barium sulfate. In addition, our results suggest that TPB prepared by dissolution in bone cement induces less osteolytic response than TPB-cement prepared by blending. The osteolysis in response to bone cement wear particles may therefore be reduced with TPB prepared using the blending technique.     

Preparation and identification of di-block copolymer composed of crystalline poly(ethylene oxide) and noncrystalline poly(vinyl acetate) with well-defined structure

A block copolymer of ethylene oxide (EO) and vinyl acetate (VAc) was prepared by sequential anionic and photo-induced charge transfer polymerization (CTP) using UV sensible p-aminophenoxy end groups on PEO (PEO_a). The structure and composition of this block copolymer (PEO-b-PVAc) were identified in detail. The relationship between polymerization rate (R_p) and the concentrations of benzophenone (BP) and monomer, and the effect of the concentration and molecular weight of PEO_a on the polymerization of VAc, are discussed; the relationship R_p ∝ [PEO_a-11000]^0.33 [VAc]^0.28 [BP]^0.47 using benzene as a solvent was derived. The dependence of the thermal properties of PEO-b-PVAc on the length of the PVAc block is described. It turned out that the PEO and PVAc blocks are compatible.     

Exaggerated neurogenic inflammation and substance P receptor upregulation in RSV-infected weanling rats

Respiratory syncytial virus (RSV) infection in adult rats causes exaggerated inflammation after sensory nerve stimulation in the extrapulmonary, but not in the intrapulmonary airways. The goal of this study was to analyze neurogenic inflammation in weanling F-344 rats infected with RSV 18 +/- 2 d after birth. Five days after RSV inoculation, the extravasation of Evans blue-labeled albumin after nerve stimulation was significantly greater in the intrapulmonary airways of RSV-infected weanling rats than in pathogen-free control rats. In contrast, no difference was found in the extrapulmonary airways. The level of messenger RNA (mRNA) encoding the substance P (SP) receptor (neurokinin 1 [NK1]) increased fourfold in RSV-infected lungs, whereas mRNA encoding the VIPR1 receptor for the antiinflammatory vasoactive intestinal peptide (VIP) increased to a much lesser degree. mRNAs encoding the other neurokinin (NK2) and VIP (VIPR2) receptors were not affected by the virus. Selective inhibition of the NK1 receptor abolished neurogenic inflammation in RSV-infected intrapulmonary airways. Also, neurogenic inflammation and NK1 receptor upregulation in infected lungs were inhibited by prophylaxis with a monoclonal antibody against RSV. These data suggest that RSV lower respiratory tract infection makes the intrapulmonary airways of young rats abnormally susceptible to the proinflammatory effects of SP by selectively upregulating the expression of NK1 receptors.     

Cytogenetic analysis of a uterine lipoleiomyoma.

We cytogenetically analyzed a uterine lipoleiomyoma. A primary chromosomal abnormality, t(12;14), was found in all 62 cells studied. A secondary change involving chromosomes 1 and 5 was detected in 15 of 62 cells. These findings suggest that lipoleiomyomas share the same chromosomal abnormalities found in common leiomyomas. We speculate that the secondary chromosomal change involving chromosomal 5 may be responsible for the lipomatous change.     

Apodemus species mice are reservoir hosts of Borrelia garinii OspA serotype 4 in Switzerland

Among Borrelia burgdorferi sensu lato isolates, seven outer surface protein A (OspA) serotypes have been described: serotypes 1 and 2 correspond to B. burgdorferi sensu stricto and Borrelia afzelii, respectively, and serotypes 3 to 7 correspond to Borrelia garinii. In Europe, serotype 4 has never been isolated from Ixodes ricinus ticks until recently, although this serotype has been frequently isolated from cerebrospinal fluid from patients. In Europe, B. afzelii and B. burgdorferi sensu stricto were found associated with rodents and B. garinii was found associated with birds. In this study, the reservoir role of Apodemus mice for B. garinii OspA serotype 4 was demonstrated by xenodiagnosis. Apodemus mice are the first identified reservoir hosts for B. garinii OspA serotype 4.     

Deletion of stem-loop 3 is compensated by second-site mutations within the Gag protein of human immunodeficiency virus type 1

Encapsidation of human immunodeficiency virus type 1 (HIV-1) RNA involves specific interactions between viral Gag proteins and viral RNA elements located at the 5' untranslated region (UTR). These RNA elements are termed packaging (psi) or encapsidation (E) signals and mainly comprise the stem-loop 1 (SL1) and SL3 RNA structures. We have previously shown that deletion of the SL1 sequences is compensated by second-site mutations within Gag. Similar studies are now extended to SL3 and the results demonstrate that deletion of this RNA structure is rescued by two point mutations, i.e., A11V in p2 and I12V in nucleocapsid (NC). These two compensatory mutations are different from those associated with the rescue of SL1 deletion, suggesting that SL1 and SL3 may bind to different residues of Gag during viral RNA packaging. Analysis of virion-derived RNA in native agarose gels shows that deletion of SL3 leads to decreases in both viral RNA packaging and dimerization. These defects are corrected by the compensatory mutations A11V and I12V. Yet, defects in viral RNA dimerization at an early stage that were caused by the SL3 deletion in the context of a viral protease-negative mutation cannot be overcome by these two suppressor mutations. Therefore, the positive effects of A11V and I12V on dimerization of the SL3-deleted RNA must have taken place at the maturation stage.     

VALUE AND LIMITATIONS OF SINUS NODE FUNCTION TE.ST BY ATRIAL PACING IN SICK SINUS SYNDROME DIAGNOSIS

In order to evaluate the significance of the sinus node function test by transvenous atrial pacing in the diagno,sis of sick sinus syndrome (SSS), sinus node recovery time (SRT), co]rrected sinus node recovery time (CSRT) and total atrio- sinus and sino-atrial conduction time (SACT) are observed in 69 patients including non-SSS group 39 cases and SSS group 30 cases. According to our data, we suggest criteria for sinus node dysfunction as follows. SRT>1,400 ms and/or A-V junctional esca.pe before sinus recovery and;or secondary pause, CSRT>560 ms. total SACT>300 ms. With l item abnormal, the false positive rat.e in the non-SSS group is 7.7c7。 and the false negative rate in the S.SS group 3.30i" with 2 items abnormal, the false positive rate in the non-SSS group Oi and the false negative rate in the SSS grOiup 6.7'70. Atropine test results are compared with that of atrial pacing, 95.8To and 84.2% are compatible with each other in these 2 groups. In order to cut the use of invasive technic to the minimum, we propose performing the atropine test first. Only in those with unexplainable test results should the trial pacing test. be resorted to..