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Biomedical subjects

M Gordon

Publications and source records attributed to M Gordon.

At least 217 records · Page 12Linked to original sources
PubMed1992

Human p150,95 alpha-subunit: genomic organization and analysis of the 5'-flanking region.

LFA-1, Mac-1, and p150,95 comprise a family of cell-surface glycoproteins that mediate adhesive interactions of myeloid and lymphoid cells. These glycoproteins are heterodimers composed of a common beta-subunit and distinct alpha-subunits. The chromosomal gene for the alpha-subunit of p150,95 was isolated to provide a framework from which to study the mechanisms for expression of the gene. The gene spans 30 kb of DNA and contains 31 exons. In agreement with a previous report by Corbi et al. (1990), the exons were found to be divided into five groups separated by large introns. The extracellular domains are encoded in exons 2 through 30 while the transmembrane and cytoplasmic domains are encoded in exons 30 and 31. We have expanded these findings in a number of ways. The first exon contains the 5' untranslated region. The 2,163-bp 5'-flanking sequence contains the first intron and several putative transcriptional initiation sites preceded by two TATA sequences and two GC-like boxes. Additional sequence motifs for a variety of DNA-binding proteins are present and discussed. Fusions of the bacterial chloramphenicol acetyltransferase gene (CAT) to approximately 5.3 kb of 5'-flanking DNA and also to subcloned fragments of this region were constructed and transfected into the human promonocytic cell line, U937. CAT expression was inducible with phorbol-12-myristate-13-acetate (PMA) and full expression was dependent on the presence of intron 1 and sequences upstream from the 2,163-bp flanking DNA. Additionally, intron 1 and a region further upstream contain functional cis-acting sequences.

Base Sequence↗
PubMed1992

Prevalence of hepatitis B surface antigen, hepatitis C antibody, and HIV-1 antibody among residents of a long-term-care facility.

OBJECTIVE: To determine the prevalence of hepatitis B antigen (HBsAg), antibody to hepatitis C virus (anti-HCV), and antibody to human immunodeficiency virus (anti-HIV) among residents of a long-term care facility. DESIGN: Anonymous unlinked serosurvey. SETTING: Accredited university-affiliated long-term-care facility in Toronto with 300 chronic-care hospital patients, 350 nursing home residents, and 200 residents of a senior citizens' apartment complex. INTERVENTIONS: Sera from left-over blood samples obtained from residents in November 1990 were tested for HBsAg, anti-HCV, and anti-HIV using standard methods. RESULTS: A total of 508 sera were tested. The number (%) positive for HBsAg, anti-HCV, and anti-HIV, respectively were: 3(0.6%), 7(1.4%), and 0(0%). CONCLUSIONS: This is the first report defining rates of infection with bloodborne infective agents among residents of a long-term care facility. These results support the use of hepatitis B vaccine for medical and nursing staff and the implementation of universal precautions in long-term care facilities.

Aged↗
PubMed1992

Transplantation of cultured premyelinating oligodendrocytes into normal and myelin-deficient rat brain.

Cultures of oligodendroglial cells at various stages of maturation, from progenitors to maturing oligodendrocytes, were prepared from neonatal rat brain primary cultures and then were prelabeled in the culture dish with the fluorescent dye, fast blue (FB). Single cell suspensions were grafted into normal or myelin-deficient rat brains. The normal as well as the myelin-deficient in vivo environment allowed cell survival, migration, and differentiation. The FB+ cells expressed the oligodendroglial markers, glycerol phosphate dehydrogenase, galactocerebroside, and myelin basic protein. In the normal rat transplanted cells were identifiable at all times studied up to 24 weeks. Extensive migration of FB+ cells was observed in whole-brain sagittal sections. Our results show that the plasticity of oligodendroglia differentiation, extensively studied in vitro, can now be investigated in the normal and myelin-deficient in vivo environment.

Animals↗
PubMed1992

Factors predicting postoperative sentence scores in postlinguistically deaf adult cochlear implant patients.

A sample of 64 postlinguistically profoundly to totally deaf adult cochlear implant patients were tested without lipreading by means of the Central Institute for the Deaf (CID) sentence test 3 months postoperatively. Preoperative promontory stimulation results (thresholds, gap detection, and frequency discrimination), age, duration of profound deafness, cause of deafness, lipreading ability, postoperative intracochlear thresholds and dynamic ranges for electrical stimulation, depth of insertion of the electrode array into the scala tympani, and number of electrodes in use were considered as possible factors that might be related to the postoperative sentence scores. A multiple regression analysis with stepwise inclusion of independent variables indicated that good gap detection and frequency discrimination during preoperative promontory testing, larger numbers of electrodes in use, and greater dynamic ranges for intracochlear electrical stimulation were associated with better CID scores. The CID scores tended to decrease with longer periods of profound deafness.

Adolescent↗
PubMed1992

Dental anxiety and oral health in young Israeli male adults.

Dental anxiety may be a serious limiting factor in providing adequate dental treatment. The present study sought to define the prevalence of dental anxiety in a cross-section of young Israeli adults (389 male Israeli army recruits) to correlate anxiety scores with their oral health status and to compare the findings with existing data. The main stimuli triggering anxiety were found to be in the following descending order: seeing the needle, feeling the drill, and feeling pain despite local anaesthesia. A positive correlation was found between the degree of anxiety and the dental status; the highest percentage of untreated patients was found in the high anxiety group. It is concluded that young adult Israeli males manifest dental anxiety in a manner similar to that reported in the United States and Sweden. Dental anxiety may be an important factor in the avoidance of seeking dental care.

Adolescent↗
PubMed1991

A phase I trial of recombinant human interleukin-1 beta alone and in combination with myelosuppressive doses of 5-fluorouracil in patients with gastrointestinal cancer.

We studied escalating doses of recombinant human interleukin-1 beta (IL-1 beta) alone and after a myelosuppressive dose of 5-fluorouracil (5-FU) in patients with gastrointestinal cancer. Transient neutropenia, monocytopenia, and lymphocytopenia were observed followed by a 1.3- to 6.0-fold (mean, 3.46-fold) dose-dependent neutrophil leukocytosis (P less than .00001) on the days of IL-1 beta administration. Increases in platelet counts were observed at a median of 14 days (range, 6 to 23) after IL-1 beta administration. Transient hypoglycemia, rebound hyperglycemia, elevations in serum cortisol, and C-reactive protein were observed. Side effects included fever, rigors, and headache in the majority of patients. Hypotension was observed in three of five patients at the highest dose level (0.1 micrograms/kg) and was dose-limiting. Fewer days of neutropenia were noted after 5-FU plus IL-1 beta than after 5-FU alone; however, this difference did not reach statistical significance. These data show that IL-1 beta has stimulatory effects in human hematopoiesis.

Adult↗
PubMed1991

Assessment of competency: the role of neurobehavioral deficits.

We present a practical set of guidelines for assessing competency in patients with cognitive deficits due to neurologic disorders such as stroke, head injury, Alzheimer disease, and multi-infarct dementia. Our focus is the evaluation of cognitive processes underlying the ability to make competent decisions, with an emphasis on the identification of areas of preserved function that may be used to bypass intellectual deficits. The assessment of the cognitive processes underlying competency involves a series of steps designed to evaluate attention, language, memory, and frontal lobe function. The examiner must first show that the patient has an adequate level of attention for participation in the further testing of specific cognitive functions; second, that the patient is able to comprehend relevant instructions, retain information long enough to evaluate it in relation to relevant recent and remote experiences, and express his or her wishes; and finally, that the patient has sufficiently intact judgment and awareness. The examiner must determine whether the patient's preserved cognitive abilities are sufficient for him or her to make an adequate judgment in relation to the specific question being asked. If cognitive function is found to be significantly impaired, the examiner should do a detailed assessment for the presence of compensatory abilities that can be used to bypass the deficits. For example, the examiner should assess whether patients who cannot speak are still able to express their wishes by pointing, using gesture, or even by drawing pictures. Unless such an assessment has been done, patients should not be considered incompetent.

Attention↗
PubMed1991

Interferon-alpha overrides the deficient adhesion of chronic myeloid leukemia primitive progenitor cells to bone marrow stromal cells.

Primitive blast colony-forming cells (BI-CFC) from chronic myeloid leukemia (CML) patients are defective in their attachment to bone marrow-derived stromal cells compared with normal BI-CFC. We investigated the effect of recombinant interferon-alpha 2a (IFN-alpha) on this interaction between hematopoietic progenitor cells and bone marrow-derived stromal cells by culturing normal stromal cells with IFN-alpha (50 to 5,000 U/mL). At 50 U/mL we found that: (1) the capacity of stromal cells to bind two types of CML primitive progenitor cells (BI-CFC and long-term culture-initiating cells) was increased; and (2) the amount of sulfated glycosaminoglycans (GAGs) in the stromal layer was increased. However, sulfated GAGs were not directly involved in binding CML BI-CFC, unlike binding by normal BI-CFC, which is sulfated GAG-dependent. Neuraminidase-treated control stromal cells bound an increased number of CML BI-CFC, reproducing the effect of IFN-alpha, whereas the binding to IFN-alpha-treated stromal cells was unaffected by neuraminidase treatment. Thus, the enhanced attachment by primitive CML progenitor cells to INF-alpha-treated stromal cells might be due to changes in the neuraminic acid composition in the stromal cell layer. Our in vitro evidence may provide insights into the mechanism of action of IFN-alpha in vivo. Prolonged administration may alter the marrow microenvironment in some patients such that it can restrain the aberrant proliferation of Philadelphia chromosome (Ph)-positive stem cells while permitting Ph-negative stem cells to function normally.

Bone Marrow↗
PubMed1991

Adapting milieu therapy to short-term psychiatric hospitalization of children.

Traditional concepts of long-term residential treatment of children are adapted for use on short-term psychiatric units. A model of milieu therapy is proposed which emphasizes the fostering of discriminate interpersonal attachments. Specific interventions, the use of limits, and the role of other therapies are discussed in the context of this model.

Child↗
PubMed1991

Clinical parameters predictive of malignancy of thyroid follicular neoplasms.

Needle aspiration biopsy is commonly employed in the evaluation of thyroid nodules. Unfortunately, the cytologic finding of a "follicular neoplasm" does not distinguish between a thyroid adenoma and a follicular cancer. The purpose of this study was to identify clinical parameters that characterize patients with an increased risk of having a thyroid follicular cancer who preoperatively have a "follicular neoplasm" identified by needle aspiration biopsy. A total of 395 patients initially treated at Vancouver General Hospital and the British Columbia Cancer Agency between the years of 1965 and 1985 were identified and their data were entered into a computer database. Patients with thyroid adenomas were compared to patients with follicular cancer using the chi-square test and Student's t-test. Statistically significant parameters that distinguished patients at risk of having a thyroid cancer (p less than 0.05) included age greater than 50 years, nodule size greater than 3 cm, and a history of neck irradiation. Sex, family history of goiter or neoplasm, alcohol and tobacco use, and use of exogenous estrogen were not significant parameters. Patients can be identified preoperatively to be at an increased risk of having a follicular cancer and accordingly appropriate surgical resection can be planned.

Adenocarcinoma↗
PubMed1991

Two years of infection surveillance in a geriatric long-term care facility.

Prospective infection surveillance was carried out for 2 years on two selected units of an 800-bed geriatric long-term care facility. Information was obtained by discussion with attending medical and nursing staff members, chart review, and review of laboratory data. Unit A houses 47 ambulatory Home for the Aged (nursing home) residents (70% female) with a mean age of 89 years. Unit B, for patients requiring chronic hospitalization, houses 32 residents (60% female) with a mean age of 77 years. The infection rates per 1000 patient-days on units A and B were 1.77 and 9.45, respectively. The higher infection rate on unit B was probably due to the presence of a more debilitated patient population. The most common sites of infection on both units were respiratory tract, urinary tract, skin, and soft tissue. The major goals of surveillance in long-term care facilities should be to aid in early detection of outbreaks and to identify preventable endemic infections. Definitions of infection and methods of surveillance that take into account the unique characteristics of elderly subjects residing in long-term care facilities with relatively limited resources need to be developed.

Aged↗
PubMed1991

The health of Travellers' children in Northern Ireland.

A study was carried out to examine aspects of the health status of children from a group of 'travelling people' in Northern Ireland. A total of 350 children, aged under 16 years, were included in the study. Data were gathered by community health doctors and health visitors using a standardised questionnaire. The study revealed that this community has a high degree of consanguinity and points to higher levels of congenital abnormalities than in the settled community. Uptake of immunisation was less than the settled community and hospital admissions in the younger age group were particularly due to infectious diseases. The authors conclude that provision of health services for travelling people in Northern Ireland should be urgently reviewed with consideration of the needs and lifestyle of this group. The provision of suitable sites for travelling people with adequate water and sewage facilities to reduce potential risks to health is also advocated.

Child↗
PubMed1991

Microleakage in three designs of glass ionomer under composite resin restorations.

Three Class V cavity configurations with walls above and below the cemento-enamel junction were compared when 'sandwich' technique restorations with glass ionomer and composite resin were used. No dye penetration occurred at the occlusal cavosurface margin when the latter was bevelled and light-cured Scotchbond was applied to the etched enamel before restoration with Durafil composite resin. The least dye penetration at the gingival margin was observed when Ketac bond glass ionomer covered the entire non-bevelled wall. No configuration entirely eliminated dye penetration at the gingival margin.

Acid Etching, Dental↗