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Biomedical subjects

A M Williams

Publications and source records attributed to A M Williams.

At least 73 records · Page 4Linked to original sources
PubMed1993

Caregivers of persons with stroke: their physical and emotional wellbeing.

This descriptive study was undertaken as a pilot test for several questionnaires designed to examine the well-being of caregivers of persons with stroke. This predominantly female sample was found to have moderately few physical symptoms, but to be in considerable emotional distress. Nearly half the sample had anxiety and depression scores above the level identified as suspicious for clinically relevant distress as indexed by the Symptom Questionnaire. Anger was also a salient finding: 40% of those questioned scored above the cutoff level for hostility and several caregivers expressed anger verbally during data collection. The degree of psychological distress in these individuals is of importance to all health care professionals and deserves increased attention, both from the perspective of the researcher and from the perspective of the clinician.

Adult↗
PubMed1992

Studies on the reactivity of acyl glucuronides--III. Glucuronide-derived adducts of valproic acid and plasma protein and anti-adduct antibodies in humans.

The major metabolite of the anti-epileptic agent valproic acid (VPA) is its acyl glucuronide conjugate (VPA-G), which undergoes non-enzymic, pH-dependent rearrangement via acyl migration to a mixture of beta-glucuronidase-resistant forms (collectively VPA-G-R). We have compared the reactivity of VPA-G and VPA-G-R towards covalent VPA-protein adduct formation by incubation in buffer, human serum albumin (HSA) and fresh human plasma at pH 7.4 and 37 degrees. In all three media, the predominant reaction of VPA-G over 30 hr was rearrangement to VPA-G-R (ca. 24%). Hydrolysis was quite minor (ca. 2%) and covalent adduct formation negligible (when protein was present). On the other hand, both hydrolysis (ca. 27%) and adduct formation (ca. 7%) were extensive when VPA-G-R was incubated with HSA or plasma. These data do not support a transacylation mechanism for VPA-protein adduct formation, since this pathway should be much more highly favoured by VPA-G (an acyl-substituted acetal) than VPA-G-R (simple esters). VPA-protein adducts were found in the plasma of epileptic patients taking VPA chronically (mean 0.77 +/- SD 0.63 microgram VPA equivalents/mL, N = 17). An enzyme linked immunosorbent assay was developed, using HSA modified by incubation with VPA-G-R, to test the immunoreactivity of the patients' plasma. Of 57 patients tested, nine showed measurable levels of antibodies to these adducts, but the titres were very low, with no difference in response to modified and unmodified protein detectable at plasma dilutions of 1:16 or greater. These results suggest that the VPA-protein adducts have little immunogenicity, and are in agreement with clinical observations that drug hypersensitivity responses have not been associated with VPA therapy. Thus, although the in vitro data show that VPA-G is an example of a relatively unreactive acyl glucuronide, covalent VPA-plasma protein adducts and anti-adduct antibodies are nonetheless formed in vivo, at least in some patients on chronic therapy with the drug.

Adult↗
PubMed1992

Self-report of indifference and anxiety among persons with right hemisphere stroke.

A sample of persons with a single ischemic cerebral stroke was used to elucidate and quantify the indifference associated with right hemisphere stroke. Seven persons with right hemisphere stroke were compared with 10 persons with left hemisphere stroke on two aspects of indifference (social indifference and lack of anxiety). Persons with right hemisphere stroke reported themselves as being substantially less anxious (p = .025) and somewhat more socially indifferent (p = .081) than did those with left hemisphere stroke. Lack of appropriate anxiety may contribute to the clinical descriptions of indifference, failure to make expected recovery, and difficulty in relationships with others.

Aged↗
PubMed1992

Sequential silastic and expandable metal stenting for tracheobronchial strictures.

The risks and limitations of surgical resection and reconstruction for tracheobronchial strictures demand consideration of other therapeutic options that can alleviate the distressing symptoms of tracheobronchial obstruction. One alternative is to stent the obstructive lesion until surgical advances allow primary reconstruction or replacement of the critically diseased airway or until an ideal endoprosthesis is found. The latter requires uniformity in the distribution of expansile force, conformability and stability within the tracheobronchial tree, and ease of placement. Here we report our experience with the placement of expandable metal stents (Wall-stent) used in conjunction with our Silastic (Dow Corning) endobronchial stents in 5 patients with recurrent tracheal or bronchial strictures. The major site of obstruction was the trachea in 1 patient and a main bronchus or both bronchi in 4 patients. Three patients had a benign bronchial stricture (anastomotic stricture in 2, idiopathic polychondritis in 1), and 2 patients had an obstructive airway neoplasm. Placement of the stents was performed under rigid bronchoscopic guidance. We had no complications from our technique of stenting. There has been no evidence of restenosis or occlusion within the stented segment of airway. The complementary use of expandable metal and Silastic endobronchial stents provided symptomatic and functional improvement in our patients during follow-up ranging from 5 to 24 months.

Adult↗
PubMed1991

A mutated transferrin receptor lacking asparagine-linked glycosylation sites shows reduced functionality and an association with binding immunoglobulin protein.

The function of the transferrin receptor is to transport iron-bound transferrin into the cell. In order to function properly, this dimeric glycoprotein must be expressed on the cell surface and be able to bind transferrin. Site-directed mutagenesis was performed to abolish the three asparagine-linked glycosylation consensus sequences of the human transferrin receptor. The DNA encoding the mutated transferrin receptor was stably transfected into mouse fibroblasts. This form of the human transferrin receptor shows reduced transferrin binding, reduced intersubunit bond formation, and reduced cell surface expression, indicating that the transferrin receptor which lacks asparagine-linked glycosylation is not fully functional. In addition, the mutated form of the receptor is not processed as quickly. It shows an association with an endoplasmic reticular chaperone protein, binding immunoglobulin protein, leading to the hypothesis that the mutated transferrin receptor experiences increased retention in the endoplasmic reticulum.

Asparagine↗
PubMed1991

Intrageneric relationships of Enterococci as determined by reverse transcriptase sequencing of small-subunit rRNA.

The 16S ribosomal ribonucleic acid (rRNA) sequences of eleven Enterococcus species were determined by reverse transcription in an attempt to clarify their intrageneric relationships. Comparative analysis of the sequence data revealed the presence of several species groups within the genus. The species E. avium, E. malodoratus, E. pseudoavium and E. raffinosus formed a distinct group as did E. durans, E. faecium, E. hirae and E. mundtii and the pair of species E. casseliflavus and E. gallinarum. Of the remaining species, E. cecorum, E. columbae, E. faecalis and E. saccharolyticus formed distinct lines of descent within the genus, whereas E. solitarius displayed a closer affinity with Tetragenococcus halophilus than with other enterococcal species.

Base Sequence↗
PubMed1991

Neuroscience nursing research: human subjects considerations.

Permission to conduct research must be obtained from all institutions which will be involved. The special nature of our target population may result in a particularly detailed review. Specific suggestions to facilitate approval to conduct research address utilization of institutional personnel, informed consent and concerns of the IRB. Seek guidance from knowledgeable employees. You can obtain a great deal of useful information from IRB secretaries and nurses who are engaged in research in the target institution. Informing potential subjects about the research is critical, and is best done using strategies such as assuring the language used enhances comprehension. Finally, be prepared to discuss concerns of the IRB. The ability of impaired subjects to communicate with you, the researcher, seems to be of particular concern to many IRBs.

Ethics, Nursing↗
PubMed1991

DNA fingerprinting of Streptococcus uberis based on polymorphism of DNA encoding rRNA.

The rRNA gene restriction patterns of strains of Streptococcus uberis and Strep. parauberis were determined. Chromosomal DNA was digested with endonucleases and probed with radiolabelled DNA complementary to rRNA synthesized by random oligonucleotide priming using reverse transcriptase. Reproducible restriction patterns were obtained which readily distinguished Strep. uberis and Strep. parauberis. In addition, considerable variations in the patterns at the intra-specific level were observed indicating that rRNA gene restriction profiles are of epidemiological, as well as taxonomic value.

Blotting, Southern↗
PubMed1991

Complications of intraaortic balloon counterpulsation insertion in patients receiving thrombolytic therapy for acute myocardial infarction.

This study retrospectively examines 38 patients who presented with acute myocardial infarction requiring intraaortic balloon pump counterpulsation. Two groups of patients were identified. Group I consisted of patients with acute myocardial infarction treated with intraaortic balloon pump without thrombolytic therapy. Group II consisted of patients treated with intraaortic balloon pump after receiving intravenous thrombolytic therapy. These groups were compared and contrasted with regard to previously identified complications associated with intraaortic balloon pump counterpulsation including loss of limb and mortality. The need for surgery, embolectomy, and drainage of hematoma were also evaluated. The need for surgery in group II (11%) and in both groups combined (7%) is lower than is generally reported in literature (range 11.6% to 34%). In addition, no patients experienced a loss of limb and no patients in the study had severe life-threatening iatrogenic morbidity or mortality. While mortality was not an end point in this study, it was noted that there was an increased survival rate in group II patients with 61% surviving until the time of hospital discharge. Also, eight out of 14 patients in group II who underwent intraaortic balloon pump counterpulsation for cardiogenic shock survived until the time of discharge. This represents a 57% survival rate for patients presenting with cardiogenic shock. We conclude that intraaortic balloon pumps can be inserted safely following thrombolytic therapy in a community hospital.

Adult↗
PubMed1990

Lactococcus piscium sp. nov. a new Lactococcus species from salmonid fish.

Chemical and molecular taxonomic studies were performed on a representative strain of some lactic acid bacteria of unknown taxonomic position isolated from salmonid fish. The results demonstrate that the fish bacterium represents a new species of the genus Lactococcus for which the name Lactococcus piscium sp. nov. is proposed. The type strain of Lactococcus piscium is NCFB 2778.

Animals↗
PubMed1990

Streptococcus parasanguis sp. nov., an atypical viridans Streptococcus from human clinical specimens.

Molecular taxonomic studies were performed on ten strains of an unusual 'viridans streptococcus' that were originally isolated from human throats, blood and urine. On the basis of DNA-DNA hybridization studies the strains formed a single homology group distinct from all recognized species of oral and viridans streptococci. 16S ribosomal RNA reverse transcriptase sequence studies confirmed the genealogical distinctiveness of the human strains. The results of the present study clearly demonstrate that the human strains represent a new species of the viridans group for which the name Streptococcus parasanguis sp. nov. is proposed. The type strain is ATCC 15912.

Base Sequence↗
PubMed1990

The phylogeny of Aerococcus and Pediococcus as determined by 16S rRNA sequence analysis: description of Tetragenococcus gen. nov.

The phylogenetic interrelationships of the genera Pediococcus and Aerococcus were investigated using reverse transcriptase sequencing of 16S rRNA. The genus Pediococcus was found to be phylogenetically heterogeneous. The four species P. acidilactici, P. damnosus, P. parvulus and P. pentosaceus formed a phylogenetically distinct group. Within this pediococcal cluster, P. acidilactici was closely related to P. pentosaceus whereas P. damnosus showed a specific relationship with P. parvulus. The species P. dextrinicus, although showing significant sequence relatedness with these pediococcal species, was peripheral to the genus. Pediococcus halophilus exhibited low sequence homology with all of the species examined and formed a distinct line of descent. Pediococcus halophilus exhibited a closer affinity with enterococci and carnobacteria than with the other lactic acid bacteria. Pediococcus urinae-equi was phylogenetically very closely related to Aerococcus viridans. The 16S rRNA sequences of the type strains of these species differed by only two nucleotides (99.9% sequence homology) and clearly demonstrate that P. urinae-equi is a member of the genus Aerococcus.

Base Sequence↗
PubMed1990

Molecular taxonomic studies on Streptococcus uberis types I and II. Description of Streptococcus parauberis sp. nov.

The nucleotide sequences of 16S ribosomal-RNA of Streptococcus uberis types I and II were determined by reverse transcriptase. Comparative analysis of the sequence data showed that the two types are phylogenetically distinct and worthy of separate species status. A new species Streptococcus parauberis is proposed for the type II strains. The type strain of Strep. parauberis is NCDO 2020.

Base Sequence↗
PubMed1989

Antiemetic superiority of lorazepam over oxazepam and methylprednisolone as premedicants for patients receiving cisplatin-containing chemotherapy.

Lorazepam, oxazepam, and methylprednisolone were compared for antiemetic efficacy in patients receiving cisplatin chemotherapy. Three consecutive courses of cisplatin-containing chemotherapy were administered at equal doses so that each patient acted as his own control. Of 100 patients randomized, 85 received at least two of the three agents and were evaluable for analysis. Lorazepam significantly reduced the number of patients with more than ten vomits compared to either oxazepam (P less than 0.05) or methylprednisolone (P less than 0.001). Lorazepam also significantly reduced the number of patients with the most severe degrees of vomiting compared to either oxazepam or methylprednisolone (both P less than 0.005). The duration of vomiting was reduced significantly after the first 48 hours postchemotherapy for those patients receiving lorazepam over those receiving methylprednisolone (P less than 0.05). Lorazepam significantly reduced the number of patients with severe nausea compared to both oxazepam and methylprednisolone (both P less than 0.05), but there were no significant differences in duration of nausea among the groups. The results of linear analogue self-assessment scores indicated a strong patient preference for lorazepam over both oxazepam and methylprednisolone. Drowsiness was significantly more common with both lorazepam and oxazepam compared to methylprednisolone (both P less than 0.001). Patients who received lorazepam or oxazepam also experienced significantly more severe drowsiness than those patients receiving methylprednisolone (both P less than 0.001). Lack of recall was significantly more common with lorazepam than with oxazepam and methylprednisolone (both P less than 0.001) and was more profound when lorazepam was compared with oxazepam (P less than 0.05) and with methylprednisolone (P less than 0.001). Methylprednisolone was administered with minimal side effects. The results of this randomized cross-over study indicate that, in the dosage/schedule used, lorazepam is a significantly superior premedicant than is either oxazepam or methylprednisolone in alleviating the distress of cytotoxic-induced emesis in patients receiving cisplatin-containing chemotherapy.

Adolescent↗
PubMed1989

Neuroscience nursing: designing the research proposal.

Writing a research proposal for a neuroscience nursing research project is much the same as writing a proposal for any other kind of research project. The same information is included in all proposals. Differences for the neuroscience nurse researcher include the nature of problems investigated (effects of various nursing care strategies on intracranial pressure, for example) and the nature of the target population, many of whom are cognitively impaired, very ill or both. More time may be involved in the collection of data from neurologically impaired persons than from normal persons.

Data Collection↗
PubMed1989

16S ribosomal ribonucleic acid sequence analyses of lactococci and related taxa. Description of Vagococcus fluvialis gen. nov., sp. nov.

The phylogenetic status of members of the genus Lactococcus and some motile strains which react with Lancefield group N antiserum was examined by reverse transcriptase sequencing of 16S ribosomal ribonucleic acid. In agreement with earlier nucleic acid hybridization and immunological studies of superoxide dismutase the 16S sequence data clearly demonstrate that the lactococci represent a distinct phylogenetic group equivalent in rank to the genera Enterococcus and Streptococcus. The motile group N strains from chicken faeces and river water, however, were found to be phylogenetically unrelated to lactococci but displayed a closer, albeit loose, association with members of the genus Enterococcus. On the basis of the present sequence data and earlier chemotaxonomic studies it is proposed that the motile group N strains be classified in a new genus Vagococcus, as Vagococcus fluvialis sp. nov. The type strain of V. fluvialis is NCDO 2497.

Animals↗