Life-sustaining treatment: a comparison of the preferences of Taiwanese older adults and their family caregiver.

BACKGROUND: Written advance directives are not common practice in Taiwan; thus, when older adults are critically ill, family members are usually the ones to make decisions regarding life-sustaining treatment. PURPOSE: This study determined how well the preferences of the family members for the older adults match the preferences of the older adults themselves with regard to life-sustaining treatment. METHODS: A cross-sectional comparative descriptive research design was used in this study. Ninety-five pairs of older adults and their families were included in the final analysis. The Life Support Preferences Questionnaire was used to measure life-sustaining preferences. Paired- sample t tests were performed to compare the mean differences between the older adults' preferences and the family members' preferences for these older adults. FINDING: Family members scored higher on life-sustaining treatment preferences than the older adults for all 32 examined items, with 23 (72%) of these items showing statistical significance. CONCLUSION/IMPLICATIONS FOR PRACTICE: Communication between older adults and their family members regarding life-sustaining treatment may help prevent older adults from receiving unwanted treatments.

Metadata-driven comparative analysis tool for sequences (meta-CATS): an automated process for identifying significant sequence variations that correlate with virus attributes.

The Virus Pathogen Resource (ViPR; www.viprbrc.org) and Influenza Research Database (IRD; www.fludb.org) have developed a metadata-driven Comparative Analysis Tool for Sequences (meta-CATS), which performs statistical comparative analyses of nucleotide and amino acid sequence data to identify correlations between sequence variations and virus attributes (metadata). Meta-CATS guides users through: selecting a set of nucleotide or protein sequences; dividing them into multiple groups based on any associated metadata attribute (e.g. isolation location, host species); performing a statistical test at each aligned position; and identifying all residues that significantly differ between the groups. As proofs of concept, we have used meta-CATS to identify sequence biomarkers associated with dengue viruses isolated from different hemispheres, and to identify variations in the NS1 protein that are unique to each of the 4 dengue serotypes. Meta-CATS is made freely available to virology researchers to identify genotype-phenotype correlations for development of improved vaccines, diagnostics, and therapeutics.

Depression and gender differences: focus on Taiwanese American older adults.

Secondary analysis of cross-sectional data was used to examine gender differences and depression in elderly Taiwanese Americans. There is a paucity of health-related research focused on Asian Americans. This is especially true in the area of mental health. Depression, the most common psychiatric illness in older adults, is under-diagnosed in Asian Americans. A convenience sample of 100 elderly Taiwanese Americans, 47 women and 53 men, was used. Women were older, had higher depressions cores, more physical illness, poorer sleep scores, and less physical activity. Regression analysis indicated that 25% of the variance in depression scores was explained by sleep quality and physical activity.

Is somatization a significant depressive symptom in older Taiwanese Americans?

Adapting to psychosocial and physical changes can trigger nonspecific somatic complaints and depression. Somatization has been noted in all societies and cultures; however, it is more frequently observed in Asian populations. This study used the Geriatric Depression Scale (GDS) to screen 100 Taiwanese American older adults for depressive symptoms and found that seven participants (7%) experienced depressive symptoms (GDS >/= 14). Although the mean number of illnesses reported was significantly higher (t = -16.8, P <.001) in the depressive group, the seven individuals did not focus on physical symptoms during interview. They reported guilt, sadness, anger, resentment, loneliness, helplessness, hopelessness, inability to enjoy activities, and anhedonia. If older adults are given the time to express themselves, they are able to reveal their emotional pain and distress rather than remain preoccupied with somatic complaints. A simple depression screening tool, such as the GDS, can help detect depression.

Airway and ventilatory equipment in field anesthesia: what's new?

Advances in medical technology provide the modern day field anesthetist with the extra edge to meet the challenges faced in the harsh environment of the battlefield and enhance the survivability of casualties. The tasks of triage, resuscitation, and administration of anesthesia can be facilitated with the use of new airway devices, portable ventilators, and monitoring devices. Before such equipment is used in the field, the anesthetist must carefully weigh the advantages and disadvantages and must be cognizant of the limitations of individual devices in different environmental settings. These devices should ideally be portable, lightweight, rugged in construction, durable, easy to use (requiring minimal training and supervision), readily replaceable, and cost-effective.

Memory functions of Taiwanese American older adults.

Memory complaints are common among older adults, of which ethnic minorities are the fastest growing group. Little is known about the memory function of Taiwanese American older adults. This article utilizes a cross-sectional, correlational design to examine the relationship between sleep, physical activity, depression, and memory self-efficacy and memory function and to determine the variance in memory function explained by the four independent variables and six control variables in Taiwanese American older adults. Memory self-efficacy correlated significantly with memory performance. Among the independent variables and control variables, age was the strongest predictor of memory function. A simultaneous multiple regression analysis showed that the four independent and six control variables together accounted for 41.8% of the variance in memory function. Results of this study are consistent with that of many other studies conducted in the United States: Memory declined with age.

Intravenous nitro-glycerine versus general anaesthesia for placental extraction--a sequential comparison.

BACKGROUND: Postpartum haemorrhage due to retained placenta is one of the commonest life-threatening conditions during the third stage of labour. Uterine relaxation is usually required to facilitate placental removal. 'Full-stomach' obstetric patients (which includes those who delivered within 48 h), parturients with a history of antepartum or recurrent postpartum hemorrhage, grand multiparity, twin pregnancy, and those with cardiac abnormalities may benefit from an alternative to volatile-based general anaesthesia for uterine relaxation to avoid complications associated with the technique (e.g. aspiration pneumonitis and cardiovascular compromise). CASE REPORT: A 34-year-old gravida 4, para 3 parturient with rheumatic valvular heart disease presented with retained placenta and postpartum haemorrhage on two consecutive deliveries and had the placenta removed manually by the same surgeon under two different anaesthetic techniques. On the first occasion, general anaesthesia was administered whereas only i.v. fentanyl and nitro-glycerine were used on the second occasion. The postoperative course was uneventful on both occasions. CONCLUSIONS: The use of nitro-glycerine was found to be efficacious for manual removal of placenta with minimal haemodynamic perturbations, avoiding the use (and associated risks) of general anaesthesia for uterine relaxation. The ability of nitro-glycerine to reduce spontaneous uterine activity, induce uterine relaxation, coupled with its short duration of action and high efficacy, may render it a safe alternative to general anaesthesia for facilitating intrauterine manoeuvres. Nitro-glycerine may be useful especially in patients with associated co-morbid chronic cardiac conditions, e.g. rheumatic heart disease, which is characterised by impaired haemodynamics and cardiac reserves.

The protocadherin PAPC establishes segmental boundaries during somitogenesis in xenopus embryos.

BACKGROUND: One prominent example of segmentation in vertebrate embryos is the subdivision of the paraxial mesoderm into repeating, metameric structures called somites. During this process, cells in the presomitic mesoderm (PSM) are first patterned into segments leading secondarily to differences required for somite morphogenesis such as the formation of segmental boundaries. Recent studies have shown that a segmental pattern is generated in the PSM of Xenopus embryos by genes encoding a Mesp-like bHLH protein called Thylacine 1 and components of the Notch signaling pathway. These genes establish a repeating pattern of gene expression that subdivides cells in the PSM into anterior and posterior half segments, but how this pattern of gene expression leads to segmental boundaries is unknown. Recently, a member of the protocadherin family of cell adhesion molecules, called PAPC, has been shown to be expressed in the PSM of Xenopus embryos in a half segment pattern, suggesting that it could play a role in restricting cell mixing at the anterior segmental boundary. RESULTS: Here, we examine the expression and function of PAPC during segmentation of the paraxial mesoderm in Xenopus embryos. We show that Thylacine 1 and the Notch pathway establish segment identity one segment prior to the segmental expression of PAPC. Altering segmental identity in embryos by perturbing the activity of Thylacine 1 and the Notch pathway, or by treatment with a protein synthesis inhibitor, cycloheximide, leads to the predicted changes in the segmental expression of PAPC. By disrupting PAPC function in embryos using a putative dominant-negative or an activated form of PAPC, we show that segmental PAPC activity is required for proper somite formation as well as for maintaining segmental gene expression within the PSM. CONCLUSIONS: Segmental expression of PAPC is established in the PSM as a downstream consequence of segmental patterning by Thylacine 1 and the Notch pathway. We propose that PAPC is part of the mechanism that establishes the segmental boundaries between posterior and anterior cells in adjacent segments.

Periodic repression of Notch pathway genes governs the segmentation of Xenopus embryos.

During the development of the vertebrate embryo, genes encoding components of the Notch signaling pathway are required for subdividing the paraxial mesoderm into repeating segmental structures, called somites. These genes are thought to act in the presomitic mesoderm when cells form prospective somites, called somitomeres, but their exact function remains unknown. To address this issue, we have identified two novel genes, called ESR-4 and ESR-5, which are transcriptionally activated in the somitomeres of Xenopus embryos by the Su(H)-dependent Notch signaling pathway. We show that the expression of these genes divides each somitomere into an anterior and posterior half, and that this pattern of expression is generated by a mechanism that actively represses the expression of the Notch pathway genes when paraxial cells enter a critical region and form a somitomere. Repression of Notch signaling during somitomere formation requires a negative feedback loop and inhibiting the activity of genes in this loop has a profound effect on somitomere size. Finally we present evidence that once somitomeres form, ESR-5 mediates a positive feedback loop, which maintains the expression of Notch pathway genes. We propose a model in which Notch signaling plays a key role in both establishing and maintaining segmental identity during somitomere formation in Xenopus embryos.

Thylacine 1 is expressed segmentally within the paraxial mesoderm of the Xenopus embryo and interacts with the Notch pathway.

The presomitic mesoderm of vertebrates undergoes a process of segmentation in which cell-cell interactions mediated by the Notch family of receptors and their associated ligands are involved. The vertebrate homologues of Drosophila &Dgr ; are expressed in a dynamic, segmental pattern within the presomitic mesoderm, and alterations in the function of these genes leads to a perturbed pattern of somite segmentation. In this study we have characterised Thylacine 1 which encodes a basic helix-loop-helix class transcription activator. Expression of Thylacine is restricted to the presomitic mesoderm, localising to the anterior half of several somitomeres in register with domains of X-Delta-2 expression. Ectopic expression of Thylacine in embryos causes segmentation defects similar to those seen in embryos in which Notch signalling is altered, and these embryos also show severe disruption in the expression patterns of the marker genes X-Delta-2 and X-ESR5 within the presomitic mesoderm. Finally, the expression of Thylacine is altered in embryos when Notch signalling is perturbed. These observations suggest strongly that Thylacine 1 has a role in the segmentation pathway of the Xenopus embryo, by interacting with the Notch signalling pathway.

The Notch ligand, X-Delta-2, mediates segmentation of the paraxial mesoderm in Xenopus embryos.

Segmentation of the vertebrate embryo begins when the paraxial mesoderm is subdivided into somites, through a process that remains poorly understood. To study this process, we have characterized X-Delta-2, which encodes the second Xenopus homolog of Drosophila Delta. Strikingly, X-Delta-2 is expressed within the presomitic mesoderm in a set of stripes that corresponds to prospective somitic boundaries, suggesting that Notch signaling within this region establishes a segmental prepattern prior to somitogenesis. To test this idea, we introduced antimorphic forms of X-Delta-2 and Xenopus Suppressor of Hairless (X-Su(H)) into embryos, and assayed the effects of these antimorphs on somite formation. In embryos expressing these antimorphs, the paraxial mesoderm differentiated normally into somitic tissue, but failed to segment properly. Both antimorphs also disrupted the segmental expression of X-Delta-2 and Hairy2A, a basic helix-loop-helix (bHLH) gene, within the presomitic mesoderm. These observations suggest that X-Delta-2, via X-Notch-1, plays a role in segmentation, by mediating cell-cell interactions that underlie the formation of a segmental prepattern prior to somitogenesis.

Recombinant feline leukemia virus genes detected in naturally occurring feline lymphosarcomas.

Using a polymerase chain reaction strategy aimed at detecting recombinant feline leukemia virus (FeLV) genomes with 5' env sequences originating from an endogenous source and 3' env sequences resulting from FeLV subgroup A (FeLV-A), we detected recombinant proviruses in approximately three-fourths of naturally occurring thymic and alimentary feline lymphosarcomas (LSAs) and one-third of the multicentric LSAs from cats determined to be FeLV capsid antigen positive by immunofluorescence assay. In contrast, only 1 of 22 naturally arising FeLV-negative feline LSAs contained recombinant proviruses, and no recombinant env gene was detected in seven samples from normal tissues or tissues from FeLV-positive animals that died from other diseases. Four preferred structural motifs were identified in the recombinants; one is FeLV-B like (recognizing that FeLV-B itself is a product of recombination between FeLV-A and endogenous env genes), and three contain variable amounts of endogenous-like env gene before crossing over to FeLV-A-related sequences: (i) a combination of full-length and deleted env genes with recombination at sites in the middle of the surface glycoprotein (SU), (ii) the entire SU encoded by endogenous-like sequences, and (iii) the entire SU and approximately half of the transmembrane protein encoded by endogenous-like sequences. Additionally, three of the thymic tumors contained recombinant proviruses with mutations in the vicinity of the major neutralizing determinant for the SU protein. These molecular genetic analyses of the LSA DNAs correspond to our previous results in vitro and support the occurrence and association of viral recombinants and mutants in vivo in FeLV-induced leukemogenesis.

The antibacterial activity of alamethicins and zervamicins.

Consistent results were obtained in biological assays of alamethicins on agar gels only when the antibiotics were allowed to diffuse under strictly defined conditions of temperature and time before inoculation. In liquid culture obligatory anaerobic rumen bacteria were sensitive to these antibiotics and in certain cases their ability to produce volatile fatty acids was reduced. Among the bacteria examined there was a 1000-fold difference in their sensitivity. Modifications of the structure of the peptaibol, e.g. substitution of an alanine residue for a 2-methylalanine residue resulted in ca two-fold changes in activity.

The antibacterial activity of some naturally occurring 2,5-dihydroxy-1,4-benzoquinones.

Polyporic acid, atromentin, bovinone, and oosporein are common metabolic products of a number of species of fungi. The related compound cochliodinol and its congeners are produced by several Chaetomium spp. These quinonoid metabolites have been shown to inhibit the growth and metabolism of a range of bacterial genera. The antibiotic activity of the quinones depends on the substituents at the 3 and 6 positions of the 2,5-dihydroxy-1,4-benzoquinone ring; in aerobic systems the activity appears to be inversely proportional to the polarity of the metabolite. It has been shown that reduction of the quinone to the hydroquinone changes the antibiotic activity of these metabolites but does not abolish it. Contrary to previous reports, the activity of these hydroquinones is not reversed by cysteine.

Effects of chetomin on growth and acidic fermentation products of rumen bacteria.

Chetomin, an antibiotic metabolite of Chaetomium spp., was tested in the form of its tetrathiol derivative for its effects on growth and carbohydrate metabolism by five strains of functionally important rumen bacteria. The compound was bacteriostatic for the strains tested and Gram-positive bacteria were more sensitive to inhibition than Gram-negative bacteria. In an anaerobic broth dilution assay using a medium lacking rumen fluid, the minimum inhibitory concentration (MIC) of chetomin which completely inhibited growth of Butyrivibrio fibrisolvens D1 for 18 h at 39 degrees C was 40 micrograms X mL-1. The MICs determined under the same conditions for Megasphaera elsdenii B159, Selenomonas ruminantium GA192, and Succinivibrio dextrinosolvens 24 were 160, 600, and 60 micrograms X mL-1, respectively. The MIC for cellulose hydrolysis by Ruminococcus albus 7 was 20 micrograms X mL-1. Chetomin at concentrations below the MIC appeared to inhibit the separation and division of cells in cultures of B. fibrisolvens D1. Chetomin consistently stimulated acetate production from glucose by B. fibrisolvens D1, M. elsdenii B159, and S. ruminantium GA192 at the expense of compounds which comprised major soluble end products of fermentation in cultures lacking chetomin.