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Biomedical subjects

M Snyder

Publications and source records attributed to M Snyder.

At least 109 records · Page 6Linked to original sources

Comparison of two teaching strategies: adherence to a home monitoring program.

Two strategies for teaching lung and heart-lung transplant subjects to use an electronic spirometer/diary instrument at home to input and transmit daily respiratory, vital sign, and symptom measurements were compared. The first strategy integrated teaching into subjects' postoperative clinic visits, whereas the second strategy involved referral to a Patient Learning Center (PLC) for instruction. Adherence was increased by 30% when the teaching was transferred from the clinic setting to the PLC. These findings suggest that the PLC is an effective resource for preparing patients to manage their care after discharge from a hospital or clinic.

Adolescent↗

Dissociation of p34cdc2 complex formation from phosphorylation and histone H1 kinase activity.

The cell cycle inhibitor mimosine was used to examine the activation of the p34cdc2 protein kinase in S phase of the cell cycle. Addition of mimosine to cycling epithelial cells halted cell cycle traverse in S phase, coincident with an inhibition of p34cdc2 histone H1 kinase activity. Mimosine treatment did not alter p34cdc2 synthesis or turnover; however, overall phosphorylation of p34cdc2 was decreased to near undetectable levels. Although activity of p34cdc2 was inhibited, the ability of the protein to form high molecular weight complexes, a phenomenon associated with kinase activation in vivo, was not affected. These results indicate that p34cdc2 complex formation can occur in the absence of phosphorylation and that phosphorylation of p34cdc2 is then required to activate these preformed complexes.

Animals↗

Two short autoepitopes on the nuclear dot antigen are similar to epitopes encoded by the Epstein-Barr virus.

To understand the relationship between antibodies present in patients with anti-nuclear dot (ND) autoimmune disease and the proteins they recognize, epitopes that react with the autoantibodies were mapped. A panel of fusion proteins containing different portions of the ND protein were overproduced in Escherichia coli. Immunoblot analysis with anti-ND antibodies revealed that most (10 of 12) sera recognize two major autoepitopes that are each a maximum of 8 amino acids long. The other two sera recognize one of the two epitopes. In addition to the short linear autoepitopes, a conformational epitope appears to be present on the ND antigen. Each of the two linear epitope sequences shares sequence similarities with those of several viral proteins found in the databases. Furthermore, two fusion proteins containing short Epstein-Barr virus (EBV) protein sequences that are similar to the ND epitopes were recognized by the human autoimmune sera, indicating that the autoepitopes are present in EBV protein sequences. Our results are consistent with the hypothesis that ND autoimmune disease might be associated with EBV infections.

Amino Acid Sequence↗

Detection of hepatitis C virus antibodies and specific hepatitis C virus ribonucleic acid sequences in cord bloods from a heterogeneous prenatal population.

OBJECTIVE: Our aim was to quantify the prevalence of at-risk pregnancies for maternal-fetal hepatitis C virus transmission in a heterogeneous prenatal population by detection of both hepatitis C virus-specific antibody and hepatitis C virus ribonucleic acid sequences in cord bloods from their deliveries. STUDY DESIGN: An anonymous serosurvey of 1432 consecutive umbilical cord blood samples were analyzed for hepatitis C virus antibodies with a second-generation enzyme immunoassay with all hepatitis C virus antibody-positive samples batched and analyzed for both human immunodeficiency virus antibodies and hepatitis C virus ribonucleic acid sequences by polymerase chain reaction. RESULTS: Forty-seven of the samples (3.2%) were positive for hepatitis C virus antibodies; seropositivity rates differed significantly by socioeconomic status but not by race. Significantly more of the antibody-positive women underwent cesarean section for delivery (31.9% vs 21.9%, p = 0.03). Three (6.4%) hepatitis C virus antibody-positive samples were also human immunodeficiency virus-antibody positive, whereas nine (19.1%) were hepatitis C virus ribonucleic acid positive. CONCLUSION: As many as 19% of hepatitis C virus antibody-positive women in this study also had hepatitis C virus ribonucleic acid isolated from their delivery cord blood samples, which may indicate an increased risk of vertical hepatitis C virus transmission in those pregnancies. Hepatitis C virus-specific antibody and ribonucleic acid detection may also be markers for other pregnancy complications that result in higher rates of cesarean section for these women.

Base Sequence↗

Sustained helping without obligation: motivation, longevity of service, and perceived attitude change among AIDS volunteers.

A conceptual framework that identifies psychological and behavioral features associated with antecedents, experiences, and consequences of volunteerism is presented, and an inventory that measures 5 specific motivations for AIDS volunteerism is developed and cross-validated. Then a field study of 116 AIDS volunteers is presented in which a helping disposition, volunteer motivations, and social support (as antecedents), and personal satisfaction and organizational integration (as experiences) are used to predict duration of service over 2 1/2 years. Structural equation analyses indicate that dispositional helping influences satisfaction and integration but not duration of service, whereas greater motivation and less social support predict longer active volunteer service. The model is generalized to the prediction of perceived attitude change. Implications for conceptualizations of motivation, theoretical issues in helping, and practical concerns of volunteer organizations are discussed.

Acquired Immunodeficiency Syndrome↗

Nuclear pore complex clustering and nuclear accumulation of poly(A)+ RNA associated with mutation of the Saccharomyces cerevisiae RAT2/NUP120 gene.

To identify genes involved in the export of messenger RNA from the nucleus to the cytoplasm, we used an in situ hybridization assay to screen temperature-sensitive strains of Saccharomyces cerevisiae. This identified those which accumulated poly(A)+ RNA in their nuclei when shifted to the non-permissive temperature of 37 degrees C. We describe here the properties of yeast strains carrying mutations in the RAT2 gene (RAT - ribonucleic acid trafficking) and the cloning of the RAT2 gene. Only a low percentage of cells carrying the rat2-1 allele showed nuclear accumulation of poly(A)+ RNA when cultured at 15 degrees or 23 degrees C, but within 4 h of a shift to the nonpermissive temperature of 37 degrees C, poly(A)+ RNA accumulated within the nuclei of approximately 80% of cells. No defect was seen in the nuclear import of a reporter protein bearing a nuclear localization signal. Nuclear pore complexes (NPCs) are distributed relatively evenly around the nuclear envelope in wild-type cells. In cells carrying either the rat2-1 or rat2-2 allele, NPCs were clustered together into one or a few regions of the nuclear envelope. This clustering was a constitutive property of mutant cells. NPCs remained clustered in crude nuclei isolated from mutant cells, indicating that these clusters are not able to redistribute around the nuclear envelope when nuclei are separated from cytoplasmic components. Electron microscopy revealed that these clusters were frequently found in a protuberance of the nuclear envelope and were often located close to the spindle pole body. The RAT2 gene encodes a 120-kD protein without similarity to other known proteins. It was essential for growth only at 37 degrees C, but the growth defect at high temperature could be suppressed by growth of mutant cells in the presence of high osmolarity media containing 1.0 M sorbitol or 0.9 M NaCl. The phenotypes seen in cells carrying a disruption of the RAT2 gene were very similar to those seen with the rat2-1 and rat2-2 alleles. Epitope tagging was used to show that Rat2p is located at the nuclear periphery and co-localizes with yeast NPC proteins recognized by the RL1 monoclonal antibody. The rat2-1 allele was synthetically lethal with both the rat3-1/nup133-1 and rat7-1/nup159-1 alleles. These results indicate that the product of this gene is a nucleoporin which we refer to as Rat2p/Nup120p.

Alleles↗

A highly divergent gamma-tubulin gene is essential for cell growth and proper microtubule organization in Saccharomyces cerevisiae.

A Saccharomyces cerevisiae gamma-tubulin-related gene, TUB4, has been characterized. The predicted amino acid sequence of the Tub4 protein (Tub4p) is 29-38% identical to members of the gamma-tubulin family. Indirect immunofluorescence experiments using a strain containing an epitope-tagged Tub4p indicate that Tub4p resides at the spindle pole body throughout the yeast cell cycle. Deletion of the TUB4 gene indicates that Tub4p is essential for yeast cell growth. Tub4p-depleted cells arrest during nuclear division; most arrested cells contain a large bud, replicated DNA, and a single nucleus. Immunofluorescence and nuclear staining experiments indicate that cells depleted of Tub4p contain defects in the organization of both cytoplasmic and nuclear microtubule arrays; such cells exhibit nuclear migration failure, defects in spindle formation, and/or aberrantly long cytoplasmic microtubule arrays. These data indicate that the S. cerevisiae gamma-tubulin protein is an important SPB component that organizes both cytoplasmic and nuclear microtubule arrays.

Base Sequence↗

Mutation or deletion of the Saccharomyces cerevisiae RAT3/NUP133 gene causes temperature-dependent nuclear accumulation of poly(A)+ RNA and constitutive clustering of nuclear pore complexes.

To identify genes whose products play potential roles in the nucleocytoplasmic export of messenger RNA, we isolated temperature-sensitive strains of Saccharomyces cerevisiae and examined them by fluorescent in situ hybridization. With the use of a digoxigen-tagged oligo-(dT)50 probe, we identified those that showed nuclear accumulation of poly(A)+ RNA when cells were shifted to the nonpermissive temperature. We describe here the properties of yeast strains bearing the rat3-1 mutation (RAT-ribonucleic acid trafficking) and the cloning of the RAT3 gene. When cultured at the permissive temperature of 23 degrees C, fewer than 10% of cells carrying the rat3-1 allele showed nuclear accumulation of poly(A)+ RNA, whereas approximately 70% showed nuclear accumulation of poly(A)+ RNA, whereas approximately 70% showed nuclear accumulation of poly(A)+ RNA after a shift to 37 degrees C for 4 h. In wild-type cells, nuclear pore complexes (NPCs) are distributed relatively evenly around the nuclear envelope. Both indirect immunofluorescence analysis and electron microscopy of rat3-1 cells indicated that NPCs were clustered into one or a few regions of the NE in mutant cells. Similar NPC clustering was seen in mutant cells cultured at temperatures between 15 degrees C and 37 degrees C. The RAT3 gene encodes an 1157-amino acid protein without similarity to other known proteins. It is essential for growth only at 37 degrees C. Cells carrying a disruption of the RAT3 gene were very similar to cells carrying the original rat3-1 mutation; they showed temperature-dependent nuclear accumulation of poly(A)+ RNA and exhibited constitutive clustering of NPCs. Epitope tagging of Rat3p demonstrated that it is located at the nuclear periphery and co-localizes with nuclear pore proteins recognized by the RL1 monoclonal antibody. We refer to this nucleoporin as Rat3p/Nup133p.

Amino Acid Sequence↗

Constraints and perspectives of advanced practice nursing in Taiwan, Republic of China.

Although master's-prepared advanced practice nurses (APNs) are used intensively in the United States, they are uncommon in most other countries. Statistics about APNs across the world are difficult to interpret because the term "specialist" does not necessarily equate with graduate preparation. This article focuses on the difficulties of implementing advanced practice nursing in Taiwan. Suggestions for future actions that may decrease these problems are presented. Based on discussions with nurses from other Asian countries, these suggestions may apply to increasing the use of APNs in these countries as well as in Taiwan.

Education, Nursing, Graduate↗

"Becoming": a method for expanding systemic thinking and deepening empathic accuracy.

The method of "becoming", as an approach to increasing empathic ability, promoting exploratory dialogue, and heightening consciousness, is described. The method is seen as applicable across theoretical orientations. It is a way to operationalize Martin Buber's concept of "inclusion," which he defined as a "bold swinging" into the consciousness of another person. Details are given about the method's application to resistance, confusion, defensiveness, criticalness, and other barriers to awareness, relationship, and the co-creation of shared meanings. Case examples are provided to illustrate the use of the method in a variety of contexts.

Adolescent↗

Local production of tumor necrosis factor-alpha in corynebacterial pulmonary lesions in sheep.

Corynebacterium pseudotuberculosis infection is a common cause of pyogranulomas in ovine lungs and often occurs as a dual infection with lentiviruses. This coinfection usually leads to the development of chronic pneumonia and cachexia that is similar to the clinical syndrome seen in human beings with AIDS-related pneumonias. Recent in vitro studies indicate that monokines such as tumor necrosis factor-alpha (TNF alpha) are induced by C. pseudotuberculosis, suggesting that TNF alpha is involved in the pathogenesis of corynebacterial lesions in vivo. To substantiate in vitro observations concerning bacterial induction of TNF alpha in ovine pulmonary macrophages, immunohistochemical labeling techniques were used in combination with in situ hybridization to identify TNF-producing cells in corynebacterial lesion sites in vivo. TNF alpha message and translation product were found in macrophages comprising pyogranulomas that were induced by naturally acquired and experimental pulmonary C. pseudotuberculosis infections.

Animals↗

Interventions for decreasing agitation behaviors in persons with dementia.

1. High stress is one of the possible causes of agitation behaviors in persons with dementia; use of stress management interventions may be helpful in reducing the stress level. 2. Two nursing interventions, hand massage and therapeutic touch, were effective in producing a relaxation response in persons with dementia who had a history of agitation behaviors; they did not, however, decrease agitation behavior. 3. Hand massage was more effective in producing relaxation than was therapeutic touch.

Aged↗

SLK1, a yeast homolog of MAP kinase activators, has a RAS/cAMP-independent role in nutrient sensing.

The Saccharomyces cerevisiae SLK1 protein is implicated in nutrient sensing and growth control. Under nutrient-limiting conditions, slk1 mutants fail to undergo cell cycle arrest. The role of the SLK1 protein in nutrient sensing was examined with respect to the cAMP-dependent protein kinase (PKA) pathway, which has a well characterized role in growth control in yeast, and by the analysis of dominant SLK1 alleles that affect the nutrient response of wild-type cells. Interactions with the PKA pathway were examined by phenotypic analysis of double mutants of slk1 and various PKA pathway mutants. Combining the slk1-delta mutation with a mutation that is thought constitutively activate the PKA pathway, pde2, resulted in enhanced growth control defects. The combination of slk1-delta with mutations that inhibit the PKA pathway, cdc25 and ras1, ras2, failed to alleviate the slk1 cell cycle arrest defect and lowered the permissive temperature for growth. Furthermore bcy1 tpk1 tpk2 tpk3w (bcy1 tpkw) mutants, which have constitutive, low-level, cAMP-independent kinase activity, exhibit nutrient sensing, which is eliminated in the slk1 bcy1 tpkw mutants. These results implicated SLK1 in PKA-independent growth control in yeast. The amino-terminal, noncatalytic region of the SLK1 protein may be important in the regulation of SLK1 function in growth control. Overexpression of this region caused starvation sensitivity in wild-type cells by interfering with SLK1 protein function.

Amino Acid Sequence↗

Large-scale analysis of gene expression, protein localization, and gene disruption in Saccharomyces cerevisiae.

We have developed a large-scale screen to identify genes expressed at different times during the life cycle of Saccharomyces cerevisiae and to determine the subcellular locations of many of the encoded gene products. Diploid yeast strains containing random lacZ insertions throughout the genome have been constructed by transformation with a mutagenized genomic library. Twenty-eight hundred transformants containing fusion genes expressed during vegetative growth and 55 transformants containing meiotically induced fusion genes have been identified. Based on the frequency of transformed strains producing beta-galactosidase, we estimate that 80-86% of the yeast genome (excluding the rDNA) contains open reading frames expressed in vegetative cells and that there are 93-135 meiotically induced genes. Indirect immunofluorescence analysis of 2373 strains carrying fusion genes expressed in vegetative cells has identified 245 fusion proteins that localize to discrete locations in the cell, including the nucleus, mitochondria, endoplasmic reticulum, cytoplasmic dots, spindle pole body, and microtubules. The DNA sequence adjacent to the lacZ gene has been determined for 91 vegetative fusion genes whose products have been localized and for 43 meiotically induced fusions. Although most fusions represent genes unidentified previously, many correspond to known genes, including some whose expression has not been studied previously and whose products have not been localized. For example, Sec21-beta-gal fusion proteins yield a Golgi-like staining pattern, Ty1-beta-gal fusion proteins localize to cytoplasmic dots, and the meiosis-specific Mek1/Mre4-beta-gal and Spo11-beta-gal fusion proteins reside in the nucleus. The phenotypes in haploid cells have been analyzed for 59 strains containing chromosomal fusion genes expressed during vegetative growth; 9 strains fail to form colonies indicating that the disrupted genes are essential. Fifteen additional strains display slow growth or are impaired for growth on specific media or in the presence of inhibitors. Of 39 meiotically induced fusion genes examined, 14 disruptions confer defects in spore formation or spore viability in homozygous diploids. Our results will allow researchers who identify a yeast gene to determine immediately whether that gene is expressed at a specific time during the life cycle and whether its gene product localizes to a specific subcellular location.

Base Sequence↗

Mutations in PRG1, a yeast proteasome-related gene, cause defects in nuclear division and are suppressed by deletion of a mitotic cyclin gene.

Proteasomes are ubiquitous complexes exhibiting proteolytic activity in vitro. The function(s) of these enzymes in vivo is not known. To investigate the in vivo role of proteasomes, four temperature-sensitive alleles of the Saccharomyces cerevisiae proteasome-related gene, PRG1, were constructed and analyzed. At both the permissive and restrictive temperatures, many prg1 cells have a large bud, contain replicated DNA, and have their nucleus positioned at the neck with a short spindle. These different phenotypes indicate a defect in nuclear division. Consistent with a nuclear division defect, prg1 mutant strains lose a dispensable chromosome at a higher frequency than wild-type cells. Importantly, deletion of CLB2, a gene encoding a mitotic cyclin, suppresses the temperature-sensitive growth phenotype of prg1 mutant strains. Our results indicate that proteasomes are important for nuclear division and suggest that they participate in degradation of the Clb2 protein (Clb2p).

Alleles↗