Positron-annihilation study of oxygen-deficient YBa2Cu3Ox (6.3

CQ Tang  BR Li  A Chen 《Canadian Metallurgical Quarterly》1990,42(13):8078-8080

Vitrectomy for retained lens fragments after phacoemulsification

PURPOSE: Posterior lens fragments after phacoemulsification can be a serious complication of cataract surgery. This study is designed to evaluate the clinical features of eyes after pars plana vitrectomy has been performed to remove posteriorly dislocated lens fragments after phacoemulsification. METHODS: The authors performed a retrospective chart review of 126 consecutive eyes of 126 patients with dislocated lens fragments after phacoemulsification, managed with pars plana vitrectomy at Associated Retinal Consultants of Michigan. These eyes were operated on from January 1986 through January 1996. RESULTS: The relation of the intervals between cataract surgery and vitrectomy to various postoperative clinical parameters was studied. Clinical features at presentation included elevated intraocular pressure (IOP over 25 mmHg) in 52.4% of the eyes, uveitis in 69.6%, and corneal edema in 50.8%. Initial visual acuity was 20/400 or worse in 73.8% of the eyes. The mean preoperative visual acuity was 20/278 (median, 20/400), whereas the mean final visual acuity was 20/40 (median, 20/50) after a mean follow-up of 18.9 months. Retinal detachments were found in 20 eyes: 7 before vitrectomy and 13 during or after it. After surgery, 44% of eyes achieved a final visual acuity of 20/40 or better and 90% were 20/400 or better. The distribution of best-corrected final visual acuities among the eyes showed statistically significant differences based on the type of intraocular lens (IOL) used, with posterior chamber IOL greater than anterior chamber IOL, and anterior chamber IOL greater than aphakia. Reasons for a poor visual outcome included persistent corneal edema (four eyes), retinal detachment (two eyes), central retinal vein occlusion (two eyes), age-related macular degeneration (two eyes) glaucoma (one year), and endophthalmitis (one eye). CONCLUSIONS: There were no statistically significant differences between early (< 7 days) and delayed (8 days or more) vitrectomy when increased IOP, corneal edema, choroidal effusions, cystoid macular edema, and visual acuity were analyzed. The use of vitrectomy to remove posteriorly dislocated lens fragments has been shown to be an effective treatment method that significantly reduces the inflammatory response and hastens visual recovery.     

Sequential addition of temperature-sensitive missense mutations into the PB2 gene of influenza A transfectant viruses can effect an increase in temperature sensitivity and attenuation and permits the rational design of a genetically engineered live influenza A virus vaccine

We have previously described a strategy for the recovery of a synthetic influenza A virus wild-type (wt) PB2 gene (derived from influenza A/Ann Arbor/6/60 [AA] virus) into an infectious virus. It was possible to introduce an attenuating temperature-sensitive (ts) mutation at amino acid residue 265 of the AA wt PB2 gene and to rescue this mutant gene into infectious virus. Application of this new technology to influenza A virus vaccine development requires that multiple attenuating mutations be introduced to achieve a satisfactorily attenuated virus that retains the attenuation (att) phenotype following replication in vivo. In this report, we demonstrate that putative ts mutations at amino acids 112, 556, and 658 each indeed specify the ts and att phenotypes. Each of these mutations was introduced into a cDNA copy of the AA mutant mt265 PB2 gene to produce three double-mutant PB2 genes, each of which was rescued into an infectious virus. In general, the double-mutant PB2 transfectant viruses were more ts and attenuated in the lower respiratory tracts of hamsters than the single-mutant transfectant viruses, and the ts phenotype of two of three double-mutant PB2 transfectant viruses was stable even after prolonged replication in the upper respiratory tracts of immunocompromised mice. Two triple-mutant PB2 transfectant viruses with three predicted amino acid substitutions resulting from five nucleotide substitutions in the cDNA were then generated. The triple-mutant PB2 transfectant viruses were more ts and more attenuated than the double-mutant PB2 transfectant viruses. These results indicate that sequential introduction of additional ts mutations into the PB2 gene can yield mutants that exhibit a stepwise increase in temperature sensitivity and attenuation compared with the preceding mutant(s) in the series. Furthermore, the level of temperature sensitivity of the transfectant viruses correlated significantly with the level of attenuation of these viruses in hamsters. Although the triple-mutant PB2 transfectant viruses were attenuated in hamsters, intranasal administration of these viruses elicited a vigorous serum hemagglutination-inhibiting antibody response, and this was associated with resistance of the lower respiratory tract to subsequent wt virus challenge. These observations suggest the feasibility of using PB2 reverse genetics to generate a live influenza A virus vaccine donor strain that contains three attenuating mutations in one gene. It is predicted that reassortant viruses derived from such a donor virus would have the properties of attenuation, genetic stability, immunogenicity, and protective efficacy against challenge with wt virus.     

Humeral epicondylitis among gas- and waterworks employees

OBJECTIVES: In this cross-sectional study 290 male employees of the public gas- and waterworks of Hamburg, Germany, were examined for symptoms of epicondylitis. Forty-one workers were diagnosed with symptoms of lateral or medial epicondylitis. The effect of employment in different job categories on the prevalence of epicondylitis was explored. METHODS: The diagnosis of epicondylitis was based on the study's own criteria and compared with criteria used in former studies. Jobs were categorized into high, moderate, and no exposure groups according to tasks regarded as strenuous for the elbow. The data were analyzed with the help of multivariate logistic regression. RESULTS: With the study's diagnostic criteria, the prevalence odds ratio (OR) for 10 years of high exposure to elbow straining work was 1.7 [95% confidence interval (95% CI) 1.04-2.68] for currently held jobs and 2.16 (95% CI 1.08-4.32) for formerly held jobs. For workers regarded as moderately exposed in current jobs the odds ratio for 10 years was 1.4 (95% CI 1.00-1.93). Very similar results were obtained for current exposure when stricter diagnostic criteria were employed. CONCLUSIONS: The results suggest a cumulative exposure effect with length of employment. Workers with high exposure in former jobs compared with employees with high exposure in their current job exhibited more residual or slight epicondylitis symptoms upon examination.     

Risk characterization of methyl tertiary butyl ether (MTBE) in tap water

Methyl tertiary butyl ether (MTBE) can enter surface water and groundwater through wet atmospheric deposition or as a result of fuel leaks and spills. About 30% of the U.S. population lives in areas where MTBE is in regular use. Ninety-five percent of this population is unlikely to be exposed to MTBE in tap water at concentrations exceeding 2 ppb, and most will be exposed to concentrations that are much lower and may be zero. About 5% of this population may be exposed to higher levels of MTBE in tap water, resulting from fuel tank leaks and spills into surface or groundwater used for potable water supplies. This paper describes the concentration ranges found and anticipated in surface and groundwater, and estimates the distribution of doses experienced by humans using water containing MTBE to drink, prepare food, and shower/bathe. The toxic properties (including potency) of MTBE when ingested, inhaled, and in contact with the skin are summarized. Using a range of human toxic potency values derived from animal studies, margins of exposure (MOE) associated with alternative chronic exposure scenarios are estimated to range from 1700 to 140,000. Maximum concentrations of MTBE in tap water anticipated not to cause adverse health effects are determined to range from 700 to 14,000 ppb. The results of this analysis demonstrate that no health risks are likely to be associated with chronic and subchronic human exposures to MTBE in tap water. Although some individuals may be exposed to very high concentrations of MTBE in tap water immediately following a localized spill, these exposures are likely to be brief in duration due to large-scale dilution and rapid volatilization of MTBE, the institution of emergency response and remediation measures to minimize human exposures, and the low taste and odor thresholds of MTBE which ensure that its presence in tap water is readily detected at concentrations well below the threshold for human injury.     

Isolation of a second recombinant human respiratory syncytial virus monoclonal antibody fragment (Fab RSVF2-5) that exhibits therapeutic efficacy in vivo

A second human respiratory syncytial virus (RSV)-neutralizing monoclonal antibody was isolated and its binding site was identified. Fab F2-5 is a broadly reactive fusion (F) protein-specific recombinant Fab generated by antigen selection from a random combinatorial library displayed on the surface of filamentous phage. In an in vitro plaque-reduction test, the Fab RSVF2-5 neutralized the infectivity of a variety of field isolates representing viruses of both RSV subgroups A and B. The Fab recognized an antigenic determinant that differed from the only other human anti-F monoclonal antibody (RSV Fab 19) described thus far. A single dose of 4.0 mg of Fab RSVF2-5/kg of body weight administered by inhalation was sufficient to achieve a 2000-fold reduction in pulmonary virus titer in RSV-infected mice. The antigen-binding domain of Fab RSVF2-5 offers promise as part of a prophylactic regimen for RSV infection in humans.     

Mapping of chromosomal gains and losses in primitive neuroectodermal tumors by comparative genomic hybridization

Pediatric fungal pulmonary infections are being seen with increasing frequency. The dimorphic fungi Histoplasma capsulatum. Blastomyces dermatitidis, Coccidioides immitis, and Cryptococcus neoformans frequently cause infections that are asymptomatic. However, patients may suffer pneumonia and disseminated disease. Diagnosis can be made definitively by isolation of the causative organism, but serology or skin testing is often necessary when this is not successful. Severe or life threatening infections are treated with amphotericin B. Recently, new oral azole antifungals are being used more frequently for mild to moderate disease with good success.     

HOPE. Home Care Outreach for Palliative Care Education

Cantu syndrome is a rare condition whose main features are hypertrichosis, cardiac anomalies and wide ribs. Four children have been described and we now present details of a further three. The parents of one of these are first cousins, adding weight to Cantu's theory that the condition is an autosomal recessive disease.     

Sequences within apolipoprotein(a) kringle IV types 6-8 bind directly to low-density lipoprotein and mediate noncovalent association of apolipoprotein(a) with apolipoprotein B-100

Lipoprotein(a) [Lp(a)] particle formation is a two-step process in which initial noncovalent interactions between apolipoprotein(a) [apo(a)] and the apolipoprotein B-100 (apoB-100) component of low-density lipoprotein (LDL) precede disulfide bond formation. To identify kringle (K) domains in apo(a) that bind noncovalently to apoB-100, the binding of a battery of purified recombinant apo(a) [r-apo(a)] species to immobilized human LDL has been assessed. The 17K form of r-apo(a) (containing all 10 types of kringle IV sequences) as well as other truncated r-apo(a) derivatives exhibited specific binding to a single class of sites on immobilized LDL, with Kd values ranging from approximately 340 nM (12K) to approximately 7900 nM (KIV5-8). The contribution of kringle IV types 6-8 to the noncovalent interaction of r-apo(a) with LDL was demonstrated by the decrease in binding affinity observed upon sequential removal of these kringle domains (Kd approximately 700 nM for KIV6-P, Kd approximately 2000 nM for KIV7-P, Kd approximately 5100 nM for KIV8-P, and no detectable specific binding of KIV9-P). Interestingly, KIV9 also appears to participate in the noncovalent binding of apo(a) to LDL since the binding of KIV5-8 (Kd approximately 7900 nM) was considerably weaker than that of KIV5-9 (Kd approximately 2000 nM). Finally, it is demonstrated that inhibition of Lp(a) assembly by proline, lysine, and lysine analogues, as well as by arginine and phenylalanine, is due to their ability to inhibit noncovalent association of apo(a) and apoB-100 and that these compounds directly exert their effects primarily through interactions with sequences contained within apo(a) kringle IV types 6-8. On the basis of the obtained data, a model is proposed for the interaction of apo(a) and LDL in which apo(a) contacts the single high-affinity binding site on apoB-100 through multiple, discrete interactions mediated primarily by kringle IV types 6-8.