Defects, human

Stem Ceii Therapy With stem cell therapy, the aim is to grow body parts to replace defective human organs and nerves. The stem cells are harvested from... 

Fleming A. The role of folate in the prevention of neural tube defects Human and animal studies. Nutr Rev 2001 58 S13. 

Xiang, Z.Q., Y. Yang, J.M. Wilson, and H.C. Ertl, A replication-defective human adenovirus recombinant serves as a highly efficacious vaccine carrier. Virology, 1996. 219(1) 220-7. 

Cara A, Guamaccia F, Reitz, Jr. MS, Gallo RC, Lori F. Self-limiting, cell type-dependent replication of an integrase-defective human immunodeficiency virus type 1 in human primary macrophages but not T lymphocytes. Virol 1995, 208 242-248. 

Acute viral hepatitis D/B is precipitated by an initially uncoated (incomplete, defective) human apathogenic viroid, which subsequently acquires HBsAg as its envelope protein. This hepatitis delta virus (HDV) becomes pathogenic as a result of two different infection modes (i.) simultaneous infection of HBV and HDV (= coinfection) and (2.) infection of a chronic HBsAg carrier with HDV (= superinfection). 

The ablation depth per pulse d vs laser fluence F0 at enamel and dentine is depicted in Fig. 31. The data follow a logarithmic law according to Eq. 6. The ablation threshold fluence Fth was determined by extrapolating the d(F0)-cmve to Fth=F0(d=0). Ablation thresholds of Fth(N=100)=0.6 J cm-2 for healthy human enamel and Fth(N=l00)=03 J cm-2 for healthy human dentine can be derived. The lower threshold for dentine may be a result of preferential ablation at an increased number of structural defects. Human enamel consists mainly of hydroxyapatite. For comparison, a monocrystalline fluoroapatite was evaluated. The ablation threshold fluence amounts to Fth(N=100)=0.8 J cm-2 [81] which is slightly higher than the F of human enamel. 

Human gene therapy A form of treatment designed to introduce DNA into cell types harboring genetic defects. Human gene therapy is only in the experimental stages but would offer an alternative to standard pharmaceutical... 

Due to their relative inertness, new applications have emerged in the biomedical field. A silicone rubber ball is used in combination with a fluorocarbon seal to replace defective human heart valves. Silicone rubber has had many applications in reconstructive surgery on or near the surface of the body. Prosthetic devices are very successfully used in all parts of the body. 

The ability of two soluble chitosan formulations (chitosan and glycol chitosan) to improve the immunogenicity of an intranasaUy administered replication-defective human adenovirus type 5 expressing BoHV-1 glycoprotein D-based vaccine was investigated in cattle (Vila et al. 2004). It was reported that soluble formulation of glycol chitosan has promising potential use as an intranasal adjuvant for recombinant viral vector vaccines in cattle. 

Gogev, S., K. de Fays, M. F. Versali, S. Gautier, and E. Thiry. 2004. Glycol chitosan improves the efficacy of intranasally administrated rephcation defective human adenovirus type 5 expressing glycoprotein D of bovine herpesvirus 1. Vaccine 22 (15-16) 1946-1953. 

Toxic gases Leakage, fugitive emission, and process defect Human protection Worker and community safety... 

Although the lesions induced by UV irradiation are primarily cyclobutane pyrimidine (particularly thymine) dimers, there are reasons to believe that these dimers are not directly involved in formation of SCE. UV irradiation also causes many other types of lesions in DNA, and it is possible that some minor component of UV-induced damage could be the SCE-inducing lesion. Studies by Wolff et a/. on a series of Chinese hamster cell lines differing in their capacity to repair UV-induced damage by excision of dimers showed that the frequency of SCE induced by UV irradiation was not related to the repair capacity of the various cell lines. These findings were recently substantiated in repair-defective human cell lines derived from XP patients. Once again, the SCE frequency did not show a consistent relationship to the ability of the various cell lines to excise thymine dimers, as measured by unscheduled DNA synthesis after UV irradiation. 

B. McCaw, A. Dipple, S. Young, and J. J. Roberts, Excision of hydrocarbon-DNA adducts and consequent cell survival in normal and repair defective human cells, Chem.-Biol. Interact. 22, 139-151 (1978). 

During the useful-life period, the hazard rate remains constant. Some of the reasons for the occurrence of failures in this region are higher random stress than expected, low safety factors, undetectable defects, human errors, abuse, and natural failures. 

Bantel-Schaal U, zur Hausen H. Characterization of the DNA of a defective human parvovims isolated fiom a genital site. Virology 1984 134 52-63. 

The approach to use multiple components is based on the Level 2 Prometheus Requirement to meet the NASA Single Point Failure Policy. NASA experience indicates the prudence of having redundant components, even if they have demonstrated reliability, to ensure that manufacturing defects, human error, or an unexpected event does not lead to a mission ending failure. This is also consistent with NRPCT practice. For those components where redundancy is considered impractical, exceptions to the single point failure avoidance requirement is provided. For the currently envisioned Prometheus spacecraft, the reactor, the reactor coolant loop, the boom, and the xenon propellant tank all require such exceptions. 

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