Synthesis in vitro of the coat protein of papaya mosaic virus

Papaya mosaic virus (PMV) RNA directs the synthesis in vitro in either the wheat germ or reticulocyte lysate translation systems of numerous products. Three polypeptides are most prominent: pA (155,000 molecular weight), pB (73,000), and pC (22,000). The last, pC, displays the same molecular weight as coat protein and is precipitated by antibodies raised against PMV. The identities of pA and pB are less clear, although peptide mapping suggests that they and many of the minor products of translation are related to each other, but not to pC. The ability of partially encapsidated PMV ribonucleoprotein particles to direct protein synthesis has been assessed. As the extent of encapsidation increased, the relative synthesis of pA and pB decreased markedly. In contrast, the synthesis of pC persisted until a substantial fraction of the PMV RNA was completely encapsidated. In view of the polarity of assembly of PMV in vitro (M. Abouhaidar and J. B. Bancroft, (1978), Virology 90, 54-59) this finding indicates that the coding sequences for PMV coat protein are localized toward the 3' end of PMV RNA. A kinetic analysis of coat protein synthesis, coupled with Northern blot analysis of PMV RNA during translation suggest that PMV RNA must be cleaved to activate it for in vitro coat protein synthesis.     

毛线柱苣苔化学成分的研究

从毛线柱苣苔(Rhynchotechum vestitum Hook.f.et Thoms.)根和茎中分得五种脂溶性成分,晶Ⅰ为β-谷甾醇(Ⅰ),晶Ⅱ为羽扇豆醇(lupeol,Ⅱ),其余三种为蒽醌化合物,晶Ⅲ和晶Ⅳ分别鉴定为甲基异茜草素-1-甲醚(rubiadin-1-methylether,Ⅲ)和甲基异茜草素°(rbuiadin,Ⅳ),晶V为一新化合物,经光谱分析初步推定其结构为1,6-二羟基-2-甲基-7,8-二甲氧基-9,10-蒽醌,命名为毛线柱苣苔蒽醌(rhynchotechol,Ⅴ)。     

Analysis of cultivable Porphyromonas gingivalis with trypsin-like protease enzyme activity and serum antibodies in chronic adult periodontitis

OBJECTIVE: Trypsin-like protease (TLPase) enzyme produced by Porphyromonas gingivalis has been implicated as a virulence factor in the pathogenesis of periodontal disease. The aims of this study were to investigate the relationship between cultivable P. gingivalis , TLPase enzyme activity (BANA hydrolysis) and serum antibody levels against cell sonicate and a purified TLPase antigen from P. gingivalis W50.
MATERIALS AND METHODS: Sub-gingival plaque samples were cultured for levels of P. gingivalis together with a chairside analysis of TLPase enzyme activity (Perioscan) from periodontitis and gingivitis sites of adult periodontitis patients. A TLPase from P. gingivalis was purified by gel filtration and ion exchange chromatogra-phy from the vesicle fraction for use as a test antigen. RESULTS: Elevated levels of P. gingivalis were found at periodontitis sites, however, there was no correlation with sub-gingival plaque TLPase enzyme activity. Adult periodontitis patients had higher levels of IgG and IgA against cell sonicate and TLPase antigens than did controls. Those patients who were P. gingivalis culture-positive demonstrated an elevated immune response against both cell sonicate and TLPase when compared to P. gingivalis culture-negative patients. Treatment resulted in an improvement of clinical indices and no cultivable P. gingivalis could be recovered from the treated sites and there was a concomitant decrease in IgG levels against the TLPase. There was no significant difference in BANA hydrolysis at gingivitis sites or periodontitis sites after treatment.
CONCLUSIONS Further longitudinal studies are suggested to investigate the role of the TLPase in the response to treatment of chronic adult periodontitis patients.     

Extracorporeal shock wave lithotripsy: interventional radiologic solutions to associated problems

Among 1,500 patients treated with extracorporeal shock wave lithotripsy, 1,300 had calculi less than 2.5 cm in diameter and 200 had calculi of 2.5 cm or larger. Although most patients did well and required no further radiologic intervention, 178 interventional radiologic procedures were performed. Urinary tract obstruction often developed in patients with large stones when the collecting system filled with stone fragments (steinstrasse). Nephrostomy was performed in 5.3% of the total patient population and in 29% of the patients with stones measuring 2.5 cm or more. Only 1.8% of the patients with calculi smaller than 2.5 cm required radiologic intervention. When the obstructed collecting system could not be crossed with conventional angiographic techniques, the stone fragments were removed through a percutaneous nephrostomy tract either by flushing or by suctioning with a pulsating water jet.     

Ventilation-perfusion scintigraphy in suspected pulmonary embolism: correlation with pulmonary angiography and refinement of criteria for interpretation

Retrospective analysis of 139 ventilation-perfusion (V/Q) lung scans obtained for suspected pulmonary embolism (PE) was undertaken, using the Biello criteria for interpretation. All scans were correlated with chest radiographs obtained within 24 hours and with pulmonary angiograms obtained within 72 hours of the V/Q study. The prevalence of PE in the high-, intermediate-, and low-probability groups was 89.5%, 49.3%, and 3.6%, respectively. Using minor modifications of these criteria, V/Q scans interpreted as high or low probability had a sensitivity of 97.1%, specificity of 94.3%, and accuracy of 95.7%. Perfusion defects corresponding to radiographic abnormalities that were present for at least 10 days were less likely to be associated with PE. Separate analysis of 27 perfusion-only lung scans that met all other criteria for inclusion in the study confirmed the nonspecificity of perfusion-only lung imaging and indicated the need for ventilation imaging with Tc-99m-DTPA aerosol or Kr-81m gas for portable studies.     

Sonographic evaluation of normal and induced ovulation

The adult premenopausal ovary exists in a dynamic state of flux, with ovarian position, size, activity, and structure constantly undergoing changes. Pelvic sonograms must be interpreted with knowledge of the stage of the menstrual cycle and the expected normal range of sonographic findings, because features that are normal in one phase may be abnormal in another. Only against this background knowledge can the challenging task of interpretation of pelvic sonograms be successfully performed. US also plays an increasingly important role in monitoring ovulation induction and alternative methods of fertilization and has improved pregnancy rates by distinguishing between the presence of one or more mature follicles as opposed to a cohort of immature follicles, suggesting the possibility of multiple ovulation with the risks of hyperstimulation or poor pregnancy outcome from multiple gestation, indicating optimum timing of human chorionic gonadotropin administration, allowing detection and confirmation of normal follicular rupture and ovulation, indicating optimum timing of oocyte retrieval in programs of in vitro fertilization with embryo transfer (IVF-ET) or insemination programs, and assessing pathologic pelvic conditions and ovarian accessibility in IVF-ET programs. Oocyte retrieval and embryo transfer are also being performed under US guidance.     

MR imaging artifacts, ferromagnetism, and magnetic torque of intravascular filters, stents, and coils

Experiments were conducted in which various intravascular filters, stents, and coils were imaged using magnetic resonance (MR) spin-echo technique at 0.35 T. These devices were also evaluated for ferromagnetism (at 0.35, 1.5, and 4.7 T), magnetic torque (at 0.35 and 1.5 T), and magnetically induced migration within a plastic tube (at 0.35 and 1.5 T for the Greenfield filter [GF]). The stainless-steel GF was evaluated in vitro for its propensity to perforate canine inferior venae cavae (IVC). Magnetic force and torque at 1.5 T did not dislodge the GF or result in perforation of canine IVC by the GF. Beta-3 titanium alloy (used in a new percutaneous version of the GF) is apparently one of the best-suited metals for use with MR imaging because of its lack of ferromagnetism (up to 4.7 T) and absence of MR imaging artifacts (at 0.35 T). Devices composed of Elgiloy (Mobin-Uddin filter), nitinol, and MP32-N (Amplatz filter) alloys all created mild artifacts. Devices fashioned from 304 and 316L (GF and Palmaz stent) stainless-steel alloys created severe "black-hole" artifacts, with the 304 alloy devices also showing marked image distortion. Generally, the greater the ferromagnetism of a device, the greater its magnetic susceptibility artifact.     

Clinical and functional properties of novel VHL mutation (X214L) consistent with Type 2A phenotype and low risk of renal cell carcinoma

Sorrell AD, Lee S, Stolle C, Ellenhorn J, Grix A, Kaelin Jr WG, Weitzel JN. Clinical and functional properties of novel VHL mutation (X214L) consistent with Type 2A phenotype and low risk of renal cell carcinoma. This report describes clinical characteristics in families with a Type 2A phenotype and functional properties of a novel von Hippel Lindau variant (X214L). Pedigrees were analyzed. Analysis of von Hippel Lindau (VHL) coding exons and flanking intronic sequences in DNA from a proband with pheochromocytoma and islet cell tumor was performed. Western blot assays for VHL protein (pVHL), HIFα, and Jun B were conducted using VHL null renal clear carcinoma cell lines that were engineered to produce wild‐type or X214L mutant pVHL. Pedigree analysis indicated that the variant tracked with disease and the same or similar VHL point mutations were identified in several Type 2A families. The predicted 14 amino acid extended pVHL variant, when reintroduced into VHL null cells, was stable and retained the ability to downregulate HIFα in a hydroxylation‐dependent manner. In contrast, the variant was defective with respect to downregulation of JunB. pVHL X214L, like other pVHL variants associated with a low risk of clear cell renal carcinoma, largely preserves the ability to downregulate HIF. In contrast, this variant, like other pVHL variants linked to Type 2A disease, fails to suppress JunB. This underscores that JunB may play a role in the pathogenesis of Type 2A VHL disease.     

Radiation fibrosis: differentiation from recurrent tumor by MR imaging

Magnetic resonance (MR) images of 21 patients who had undergone radiation therapy were analyzed and compared with those of 15 patients who had untreated tumors. T2-weighted images (TR = 1,500 msec, TE = 90 msec) were most helpful in distinguishing recurrent tumor from radiation fibrosis. Radiation fibrosis, like muscle, usually remained low in signal intensity on T2-weighted images, while tumor demonstrated higher signal intensity. In no patient was the signal intensity of tumor the same or less than muscle on the T2-weighted images. However, relatively high signal intensity on T2-weighted images is not specific for tumor recurrence and may be seen in acute radiation pneumonitis, infection, hemorrhage, and even pulmonary radiation fibrosis.