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[Study on the principles of base change in 4-fold degenerate sites of protein coding genes].

The relationship of transition and transversion of base change in 4-fold degenerate sites of coding genes of 6 proteins, which showed 70% homology in wmposition investigated. Taking into account of the effects of base composition on base substitution, it was found that the transition-transversion bias was evident but not as pronounced as in mitochondrial DNA. Comparison of different kinds of transition or transversion indicated that they happened with rather equal vate, with 0.65-0.73 for different kinds of transversion and 0.99 for A-G transition assuming that T-C transition was 1. The causes for transition-transversion bias is discussed and it is proposed that mutagens may play a role in it.

Animals↗

Mutations in the helper component protease gene of zucchini yellow mosaic virus affect its ability to mediate aphid transmissibility.

The nucleotide sequence of the helper component protease (HC-Pro) genes of three zucchini yellow mosaic virus (ZYMV) strains has been compared with that of a helper-deficient strain of ZYMV-HC. The comparisons revealed three unique deduced amino acid differences. Two of these mutations were located in regions which are conserved in other potyviruses. The role of these mutations in aphid transmissibility was examined by exchanging DNA fragments of part of the deficient HC-Pro gene with the respective section within the gene of the infectious full-length clone of the aphid-transmissible ZYMV. The first exchange included two of the three mutations, the first coding for a change from Asp to Gly (in a non-conserved region) and the second coding for a change from Arg to Ile [within the Phe-Arg-Asp-Lys (FRNK) conserved box]. This exchange resulted in a reduced transmission (20.6% for the mutated virus compared with 57.4% in the normal ZYMV when acquired from plants and 37.2% compared with 83.1%, respectively, when acquired from membranes). The second exchange incorporated a single mutation [conferring a change from Thr to Ala within the Pro-Thr-Lys (PTK) conserved box]. This single mutation resulted in almost total loss of HC activity in aphid transmission both from plants and from membranes. The Lys residue in the conserved Lys-Ile-Thr-Cys (KITC) box, which is related to loss of HC activity in potato virus Y, tobacco vein mottling virus and in the Michigan strain of ZYMV, is unchanged in the helper-deficient ZYMV. It is therefore proposed that more than one site in HC-Pro may be functionally related to aphid transmissibility. The possible reasons for the role of these mutations in helper activity in aphid transmission of ZYMV are discussed.

Amino Acid Sequence↗

Health care reform: managed competition and beyond.

Since the election, the health care reform debate has focused on three broad features: implementation of managed competition, changes in the tax treatment of health insurance, and the imposition of budget caps or targets. The basic element of managed competition is the creation of sponsors who act as collective purchasing agents for large groups of individuals. One of the potentially most politically difficult issues in implementing any health care reform proposal is likely to be defining the minimum standard benefit package. It will determine the costs society bears, the income of providers, the health of many individuals, and the attributes of a workable health care reform package. Managed competition is intended to foster competition among health plans on the basis of cost and quality. The measures of quality actually employed in the health care system will determine in large part the incentives faced by insurers, providers, and consumers. The problem of adverse selection is potentially the most important issue in reforming the health insurance market. If individuals can opt not to purchase health benefits, poorer risks will be more likely to purchase health insurance than good risks, and at minimum the price of these benefits will be higher than would otherwise be the case. Managed competition requires that individuals share at least some of the financial consequences of their choices among health plans. As a result, most managed competition proposals change the tax code by limiting the exclusion of employer contributions to health insurance from worker's taxable income. Changing the health insurance market, mandating employer health benefits, and changing the tax code may have significant effects on the health care delivery system, but they are unlikely to reduce health care cost inflation in the near term. One of the proposals for restraining the growth in health care costs is the imposition of a budget on the amount spent on health care services. The combination of the constraints placed on federal governmental action by the budget and the significant political problems involved in reaching a consensus on the important elements of health care reform may limit the ability of the federal government to implement national health care reform in the near term. As a result, individual states may be encouraged by the federal government to continue to experiment with their own health reform programs.

Budgets↗

The genetic code in mitochondria and chloroplasts.

The universal genetic code is used without changes in chloroplasts and in mitochondria of green plants. Non-plant mitochondria use codes that include changes from the universal code. Chloroplasts use 31 anticodons in translating the code; a number smaller than that used by bacteria, because chloroplasts have eliminated 10 CNN anticodons that are found in bacteria. Green plant mitochondria (mt) obtain some tRNAs from the cytosol, and genes for some other tRNAs have been acquired from chloroplast DNA. The code in non-plant mt differs from the universal code in the following usages found in various organisms: UGA for Trp, AUA for Met, AGR for Ser and stop, AAA for Asn, CUN for Thr, and possibly UAA for Tyr. CGN codons are not used by Torulopsis yeast mt. Non-plant mt, e.g. in vertebrates, may use a minimum of 22 anticodons for complete translation of mRNA sequences. The following possible causes are regarded as contributing to changes in the non-plant mt: directional mutation pressure, genomic economization, changes in charging specificity of tRNAs, loss of release factor RF2, changes in RF1, changes in anticodons, loss of lysidine-forming enzyme system, and disappearance of codons from coding sequences.

Animal Population Groups↗

Molecular characterization of three mutations in katG affecting the activity of hydroperoxidase I of Escherichia coli.

Hydroperoxidase I (HPI) of Escherichia coli is a bifunctional enzyme exhibiting both catalase and peroxidase activities. Mutants lacking appreciable HPI have been generated using nitrosoguanidine and the gene encoding HPI, katG, has been cloned from three of these mutants using either classical probing methods or polymerase chain reaction amplification. The mutant genes were sequenced and the changes from wild-type sequence identified. Two mutants contained G to A changes in the coding strand, resulting in glycine to aspartate changes at residues 119 (katG15) and 314 (katG16) in the deduced amino acid sequence of the protein. A third mutant contained a C to T change resulting in a leucine to phenylalanine change at residue 139 (katG14). The Phe139-, Asp119-, and Asp314-containing mutants exhibited 13, less than 1, and 18%, respectively, of the wild-type catalase specific activity and 43, 4, and 45% of the wild-type peroxidase specific activity. All mutant enzymes bound less protoheme IX than the wild-type enzyme. The sensitivities of the mutant enzymes to the inhibitors hydroxylamine, azide, and cyanide and the activators imidazole and Tris were similar to those of the wild-type enzyme. The mutant enzymes were more sensitive to high temperature and to beta-mercaptoethanol than the wild-type enzyme. The pH profiles of the mutant catalases were unchanged from the wild-type enzyme.

Base Sequence↗

[Ethics in nursing].

Synopsis about the evolution of moral principles adopted by brazilian nursing since 1923 to nowadays. It indicates a metaphysical, abstract and spiritual tendencies in the codes of 1958 and 1975, and a change in the code of 1993, which searches to observe valuables of historic form and based on material conditions of existence.

Brazil↗

Levels of translatable mRNA coding for rat liver glucokinase.

Changes in the level of translatable mRNA coding for glucokinase under different physiological conditions were determined using a reticulocyte lysate translation system and immunoprecipitation. Poly(A+) RNA isolated from livers of rats fed a high carbohydrate diet displayed a 10-fold increase in glucokinase template activity when compared to starved rats. Livers from streptozotocin-induced diabetic rats had only 9% of the glucokinase template activity displayed by controls. Administration of insulin to diabetic rats produced an increase in the level of mRNA coding for glucokinase within 20 min and reached a maximum 13-fold increase 1 h following insulin treatment. Under all experimental conditions examined, changes in the level of glucokinase mRNA were accompanied by similar changes in direction and magnitude of enzyme activity and the relative rate of synthesis of the enzyme in vivo. In addition, the developmental appearance of glucokinase activity at the 16th day following birth was accompanied by a corresponding increase in the amount of glucokinase mRNA. Thus, it appears that dietary, hormonal, and developmental changes in the activity of glucokinase arise as the result of changes in the amount of functional mRNA coding for the enzyme.

Animals↗

Partial nucleotide sequence of South American yellow fever virus strain 1899/81: structural proteins and NS1.

We have partially cloned and sequenced the genome of a Peruvian yellow fever virus isolate (1899/81) and compared the nucleotide and deduced amino acid sequences of this strain with the previously published sequence of the West African yellow fever virus strain Asibi. In the 3594 base region sequenced, which contains the structural genes (C, M, E), all but the 72 3'-terminal nucleotides of the NS1 gene and 108 nucleotides of the 5' non-coding region, 515 nucleotide substitutions were detected. Nucleotide divergence was lowest in the 5' non-coding region, 2.8%, compared with an average rate of 14.7% in the coding regions. Over 91% of the 512 nucleotide changes in the coding region were silent; 44 amino acid substitutions resulted. The capsid protein was the least conserved, whereas the M protein was the most highly conserved (6.7% and 1.3% divergence, respectively). The envelope protein had 18 amino acid changes (3.7% divergence), one of which created an additional site for potential glycosylation of the 1899/81 virus. NS1 protein divergence (3.9%) was similar to that seen in the E protein. Of the 44 amino acid substitutions found, 34 (77%) were conservative. The highest number of nonconservative differences occurred in the envelope glycoprotein. These changes may significantly affect the antigenic and biological functions of the viruses.

Amino Acid Sequence↗

Ischemia induces changes in the level of mRNAs coding for stress protein 71 and creatine kinase M.

Hyperthermia, hypoxia, and other conditions induce the appearance of heat shock or stress proteins in cells. We have previously shown that in the ischemic dog myocardium the level of a messenger RNA (mRNA) coding for a protein with migration characteristics similar to heat shock/stress protein 71 increases. Using a human heat-shock protein (hHSP) 70 genomic clone and anti-HSP70 antibodies as probes, we demonstrate in this report that heart stress protein (SP) 71 mRNA and its translational products (71 kDa polypeptides) are members of the stress protein family. In rabbit hearts, the ischemia-induced mRNAs translate into three isoforms with different isoelectric points (6.0, 6.1, and 6.15), in contrast to dog heart mRNA that translates into a protein with a pI of 5.8. The levels of SP71 mRNA in the dog and rabbit ischemic myocardium increased by sixfold and 18-fold, respectively. In the same samples, the levels of creatine kinase M mRNA decreased by about 40%, whereas those of myosin heavy chain mRNA remain unaltered. Our comparative analysis of three different mRNAs indicates that ischemia manifests its effects by differentially changing the levels of specific mRNAs coding for proteins with separate and distinct roles in the cell.

Animals↗

[A method for the quantitative evaluation of the probability of ischemic heart disease in epidemiological research on workers exposed to harmful effects].

A method for quantitative evaluation of the probability for ischaemic disease of the heart in epidemiological studies is recommended and the state of risk is determined by riskogram, including 3 parts: 1. Assessment of the electrocardiographic changes after Minnesota code. 2. Integral quantitative interpretation of ECG-changes with the data from the Rose test. 3. Classified quantitative assessment of the probability for ischaemic disease of the heart. The quantitative interpretation of the probability for ischaemic disease of the heart allows the use of various statistical methods, mathematical models and computer processing of data, received at the epidemiological studies. By tracing the dependences "dose-effect" and "dose-response" the maximum admissible duration of the length of service could be predicted in specific conditions of professional exposure, in order to prevent injury of the cardiovascular system from harmful industrial factors.

Bulgaria↗

Production of transgenic mice and application to immunology and autoimmunity.

During the last decade, transgenic animal technology has assumed an increasingly important role as a critical tool in animal biology, biomedical research, and pharmaceutical development. This technology allows virtually any fragment of DNA large enough to contain an entire gene to become integrated into the germline of the recipient animal. The newly inserted DNA will be inherited like endogenous genes, and will be expressed as RNA and protein at tissue locations and abundance depending on regulatory elements attached to the coding DNA. It is possible to clone a particular gene, change a regulatory coding sequence, and reinsert the gene to determine the effect of the change on expression and function of the gene.

Allergy and Immunology↗

Changing faces: visual and non-visual coding processes in face recognition.

Two experiments examined the effect of recognition accuracy and latency of changing the view of faces between presentation and test. In Expt 1, all the faces were unfamiliar to the subjects. Faces at test were either unchanged, or changed in angle (e.g. full face to 3/4), expression (e.g. smiling to unsmiling) or both. Unchanged faces were recognized more quickly and accurately than faces with a change in angle or expression which were in turn better than faces with both changed. In Expt 2, half the faces were highly familiar to the subjects, and at test unfamiliar and familiar faces were either unchanged or changed in both angle and expression. Unfamiliar faces were recognized more slowly and less accurately if changed at test, while familiar faces were recognized more slowly though no less accurately if change (though performance was effectively at ceiling). Familiar faces were recognized more quickly and accurately than unfamiliar, though false positive rates and rejection latencies were similar for familiars and unfamiliars. The results are discussed in terms of the combination of information from "pictorial', "structural', and "semantic' and "name' codes.

Discrimination Learning↗

Dynamic typology clustering within the stages of change for smoking cessation.

Dynamic typology clustering was employed to find homogeneous subgroups of smokers within each of three early stages of change (precontemplation, contemplation, preparation) in a representative sample of smokers. Individual change profiles were created by coding the stage of change for each subject at five consecutive assessment points over a 2-year period (baseline and 6, 12, 18, and 24 months). A total of 446 unique change profiles were found in the sample of 2,088 smokers who had complete data for all five time points. The sample was initially split into three groups determined by baseline stage of change. Within each initial stage, subgroups that shared similar patterns of change were interpreted by examining the shape and elevation of the change profiles. Four major types of profiles emerged: a stable profile, a progressing profile, a vacillating profile, and a regressing profile. External validation revealed significant differences among the dynamic typology subtypes on key transtheoretical model constructs (processes of change, decisional balance, situational temptations). These results both support and complement key construct relationships within the transtheoretical model and can provide important predictive information to direct and enhance treatment interventions for smoking cessation.

Adult↗

The 13 errors.

The reality is that most change efforts fail. McKinsey & Company carried out a fascinating research project on change to "crack the code" on creating and managing change in large organizations. One of the questions they asked--and answered--is why most organizations fail in their efforts to manage change. They found that 80 percent of these failures could be traced to 13 common errors. They are: (1) No winning strategy; (2) failure to make a compelling and urgent case for change; (3) failure to distinguish between decision-driven and behavior-dependent change; (4) over-reliance on structure and systems to change behavior; (5) lack of skills and resources; (6) failure to experiment; (7) leaders' inability or unwillingness to confront how they and their roles must change; (8) failure to mobilize and engage pivotal groups; (9) failure to understand and shape the informal organization; (10) inability to integrate and align all the initiatives; (11) no performance focus; (12) excessively open-ended process; and (13) failure to make the whole process transparent and meaningful to individuals.

Humans↗

The PMAC code of marketing practices: time for improvement? Pharmaceutical Manufacturers Association of Canada.

In this issue (see pages 351 to 356) Dr. Joel Lexchin proposes reforms that could help the Pharmaceutical Manufacturers Association of Canada (PMAC) adapt its Code of Marketing Practices to changing times. The PMAC code reflects the ethical concerns of drug manufacturers and speaks to the need for high standards in promotional activities. The code is a commendable beginning, but it does not go far enough in ensuring ethical practice. The PMAC should take this opportunity to address the concerns raised by Lexchin. For example, proactive assessment of advertising would improve the current system.

Advertising↗

Development and evolution of electrocardiographic Minnesota Q-QS codes in patients with acute myocardial infarction.

The development of ECG Minnesota Q-QS codes and their subsequent evolution were studied in the first 692 subjects to enter the POSCH program who had had one MI. The mean interval from MI to entry into the study was 2.2 years. Sixty-three percent of the subjects developed the most significant code with the infarction. By the time the subjects entered the study, the codes had commonly regressed to a lower level, disappearing altogether in 34%. The likelihood of complete regression varied inversely with the significance of the code. There was no significant difference between the groups with disappearance and with retention of a Q-QS code as to time since MI, the extent of coronary arterial disease, or the age or sex of the subject. In about half of the subjects the original code did not change with time and in 21% to 44% the code increased to one of a higher level of significance.

Adult↗

Resource-Based Relative Value Scale (RBRVS), coding, and Medicare reimbursement.

Many changes occurred during 1996 in the Resource-Based Relative Value Scale that determines physician payment for services to Medicare beneficiaries in 1997. These issues include the 5-year review of physician work values, the Correct Coding Initiative, changes in the surgical Conversion Factor, and a new Medicare payment formula. Likewise, several more changes on the horizon in 1997 will dramatically impact the 1998 Medicare Fee Schedule, primarily the upcoming resource-based Practice Cost Relative Value Scale, and possible elimination of the separate surgical Conversion Factors. There are also several new Current Procedural Terminology codes that will receive Medicare payment in 1997 and 1998. This article summarizes these events and issues from a vascular surgical perspective.

Centers for Medicare and Medicaid Services, U.S.↗

Integrating behavior and cardiovascular responses: the code.

The next revolution in biology is predicted to be in the integrative domain, and the need to involve physiologists in this kind of research has been recognized. This paper represents an approach to providing some of the tools required for dealing with integrative physiology at the behavioral level. Video tape recordings are made of the activities of a group of five baboons (Papio hamadryas) while simultaneous recordings of arterial blood pressure, heart rate, renal blood flow, and mesenteric or iliac blood flow are telemetered from two of the members of the group. The telemetered cardiovascular information is recorded on the two audio channels of the videotape. Subsequently the videotape is viewed, and a two-dimensional code is used to record the behavior of the two animals with the telemetry equipment. The first dimension of the code categorizes the behavior changes precisely regarding those aspects of behavior that are related to cardiovascular dynamics and does so with an accuracy of 16 ms. The second dimension codes relevant environmental changes. The paper describes the code and presents illustrations of how the code reflects the cardiovascular dynamics associated with the behavioral changes.

Animals↗