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Biomedical subjects

V Lee

Publications and source records attributed to V Lee.

At least 91 records · Page 5Linked to original sources
PubMed1996

Differential expression of two beta-galactoside-binding lectins in the reproductive tracts of pregnant mice.

Two beta-galactoside-binding proteins were isolated from uteroplacental complexes of pregnant mice and identified as the S-Lac lectins galectin-1 and galectin-3. The spatiotemporal pattern of appearance of those proteins was determined by immunocytochemistry. Galectin-1 was present in all tissue compartments of the uterus except the luminal and glandular epithelium. It was found in the uteri of animals from all preimplantation stages of pregnancy, as well as in those from nonpregnant, ovariectomized, or sexually immature animals. After implantation of the embryo, cells of the decidua basalis were labeled, as were granular metrial gland cells, all trophoblastic elements of the placenta, the myometrium, and nondecidualized endometrium. By contrast, there was little evidence of galectin-3 in the uteri of nonpregnant animals or during the preimplantation stages of pregnancy. However, immunoreactive material was observed in endometrial cells of the primary decidual zone immediately after implantation and at later stages of pregnancy in the decidua basalis, metrial gland, and all trophoblastic elements of the placenta. There was no evidence of galectin-3 in the myometrium or nondecidualized endometrium. After parturition, amounts of galectin-3 in the endometrium and metrial triangle appeared to decrease as the implantation sites were resorbed. These data suggested that the function of galectin-1 is one of tissue maintenance, whereas the function of galectin-3 is related specifically to pregnancy.

Amino Acid Sequence↗
PubMed1996

Occupational stress and organizational commitment in nurse administrators.

OBJECTIVE: The authors explore levels of occupational stress (burnout) and organizational commitment (intent to stay), their inter-relationships, and their relationships to personal and organizational factors in nurse administrators. BACKGROUND: Although the concepts of burnout and turnover have been studied and reported for staff nurses, relatively few such studies exist in relation to nurse administrators. METHODS: Consequently, the Maslach Burnout Inventory, the Organizational Commitment Questionnaire, and a personal data sheet were completed by respondents to a mailed survey representing 65.6% of the membership of the state's nurse executive organization and 58.2% of the state's hospitals (N = 78). RESULTS: Scores indicate that half the respondents experience low levels of burnout whereas a third have high levels of burnout. Commitment scores were high for most nurse executives and were correlated inversely with burnout scale scores (depersonalization, personal accomplishment, emotional exhaustion), with the amount or phase of burnout, and with non-nursing management experience. Those with few opportunities to meet with colleagues scored higher on emotional exhaustion and lower on personal accomplishment scales. Intent to stay (high commitment scores) was related positively to perceived organizational support and to religiosity. CONCLUSIONS: Findings are consistent with those reported in other studies; however, the administrative role may require unique approaches to avoid or correct organizational stress. The role of social support, the determination of organizational/individual fit, and the adaptation of traditional organizational development techniques to the administrative role are discussed and proposed as areas for further study.

Adult↗
PubMed1994

Structure and localization of the IGFBP-1 gene and its expression during liver regeneration.

Insulin-like growth factor-binding protein-1s are important modulators of the insulin-like growth factors that may have both positive and negative effects on the ability of insulin-like growth factors to stimulate cell growth. The IGFBP-1 gene is one of the most highly induced immediate-early genes after partial hepatectomy. The IGFBP-1 gene is also expressed at a high level during fetal liver development and in response to nutritional changes and diabetes. Therefore it may have important roles in liver growth and metabolism. To begin to examine the regulation of this gene, we cloned and sequenced the entire mouse IGFBP-1 gene. Its structure is highly similar to that of the human gene, and, in addition to the exonic regions, the two genes are highly conserved in specific regions in the promoter and first intron. Analysis of this conservation allows us to predict important regulatory sites that define the tissue specific and insulin-mediated regulation of the gene and identify potential sites that might be important for the transcriptional induction during liver regeneration. The mouse gene is located on mouse chromosome 11; it is found at the boundary between regions in the mouse genome homologous to human chromosomes 22 and 7. We found IGFBP-1 mRNA in both parenchymal and nonparenchymal RNA after partial hepatectomy. Using in situ hybridization of IGFBP-1 mRNA in regenerating rat liver tissue, we demonstrated IGFBP-1 transcripts in several cell types. We found that IGFBP-1 gene induction after partial hepatectomy is paralleled by protein expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1994

The mammalian zona pellucida: its biochemistry, immunochemistry, molecular biology, and developmental expression.

Many studies of the molecular and biochemical aspects of mammalian fertilization have focused on the interaction of the spermatozoa with the zona pellucida (ZP). The zona pellucida, a unique extracellular matrix surrounding the mammalian oocyte, is formed during ovarian follicular development. Following ovulation of the mature ovum, the spermatozoa must bind to and penetrate this matrix before the fertilization process is completed and the male and female genetic information combine. Although numerous models for this interaction have been proposed, the complete process has yet to be elucidated. The precise mechanisms by which these interactions occur also vary markedly among different mammalian species, making it more difficult to establish a unified model. To a great extent, the study of the molecules involved in these interactions have been limited because small numbers of female gametes are available for these studies. The recent development of techniques to isolate large numbers of zonae pellucidae as well as advances in immunological and molecular biology techniques have permitted the detailed characterization of ZP proteins. Although there is a paucity of information on the post-translational modification and extracellular processing of these molecules which result in matrix formation, a number of properties have been elucidated allowing better correlation between the structure and function of different ZP proteins among species. This review reflects these studies in relation to protein nomenclature and the molecular complexity of ZP antigens.

Animals↗
PubMed1994

The efficacy of sequential compression devices in multiple trauma patients with severe head injury.

Thirty-two multiple trauma patients with severe head injury and a Glasgow Coma Scale (GCS) score of 8 or less were prospectively studied to assess the occurrence of deep venous thrombosis (DVT) and pulmonary embolism (PE). All patients required mechanical ventilation. A sequential compression device (SCD) was used in 14 patients and 18 patients received no prophylaxis for thromboembolism. Bilateral lower extremity technetium venoscans and ventilation/perfusion (V/Q) lung scans were performed within 6 days of admission and every week for 1 month or until the patient developed DVT or PE or was discharged from the SICU. Deep venous thrombosis occurred in two patients (6%) at 16 and 28 days following trauma. Twenty-five patients had normal or low probability V/Q scans. Six had high probability V/Q scans confirmed by pulmonary arteriograms (PAGs) at 12.5 +/- 4 days. Clinical signs of PE were absent in all patients with a positive PAG. There were no differences in age, Injury Severity Score (ISS), GCS Score, APACHE II Score, or Trauma Score between the patients who developed DVT or PE and those who did not. A SCD was used in four of the eight patients with DVT or PE. All but one patient with DVT or PE underwent placement of a vena caval filter. Multiple trauma patients with severe head injury (GCS score < or = 8) are at high risk for thromboembolism. The available means of prevention and diagnosis of DVT or PE in multiple trauma patients with severe head injury are not entirely effective.

Adult↗
PubMed1994

Laparotomy for trauma in a regional centre: the effect of delay on outcome.

From 1983 to 1990, 110 patients with abdominal trauma required laparotomy in the Albury-Wodonga region. Splenic and liver injuries occurred in 50% of cases, and bowel trauma in 20%. The mortality rate was 8.2% (nine deaths) and major postoperative complications occurred in 18 patients (16%). Delay in therapeutic intervention of greater than 4 h from hospital admission led to a statistically significant increase in the complication rate (P < 0.01) despite a lower injury severity score in this group. Delayed repair of bowel injuries in particular led to an 80% major complication rate in survivors. A high index of clinical suspicion and the regular use of diagnostic peritoneal lavage is suggested to avoid such delays in diagnosis and subsequent surgery.

Abdominal Injuries↗
PubMed1994

Direct injection of a recombinant retroviral vector induces human immunodeficiency virus-specific immune responses in mice and nonhuman primates.

The cytotoxic T-lymphocyte (CTL) response plays an important role in controlling the severity and duration of viral infections. Immunization by direct in vivo administration of retroviral vector particles represents an efficient means of introducing and expressing genes and, subsequently, the proteins they encode in vivo in mammalian cells. In this manner foreign proteins can be provided to the endogenous, class I major histocompatibility complex antigen presentation pathway leading to CTL activation. A nonreplicating recombinant retroviral vector, encoding the human immunodeficiency virus type 1 (HIV-1) IIIB envelope and rev proteins, has been developed and examined for stimulation of immune responses in mouse, rhesus macaque, and baboon models. Animals were immunized by direct intramuscular injection of the retroviral vector particles. Vector-immunized mice, macaques, and baboons generated long-lived CD8+, major histocompatibility complex-restricted CTL responses that were HIV-1 protein specific. The CTL responses were found to be dependent on the ability of the retroviral vector to transduce cells. The vector also elicited HIV-1 envelope-specific antibody responses in mice and baboons. These studies demonstrate the ability of a retroviral vector encoding HIV-1 proteins to stimulate cellular and humoral immune responses and suggest that retrovector immunization may provide an effective means of inducing or augmenting CTL responses in HIV-1-infected individuals.

Animals↗
PubMed1992

Opponensplasty by extensor indicis and flexor digitorum superficialis tendon transfer.

From 1977 to 1988, 166 patients with median nerve paralysis of varied aetiology underwent opponensplasty. In 50 of these the extensor indicis was used, and in 116 the flexor digitorum superficialis of the ring finger. An analysis of these hands showed that the EI opponensplasty was best in supple hands and FDS opponensplasty was more suitable for less pliable hands. There were fewer complications seen after FDS opponensplasty if the detachment of the donor tendon was done through a volar oblique incision rather than the conventional lateral incision.

Adolescent↗
PubMed1992

Psychiatric services: a survey of nursing homes and homes for the aged in Ontario.

A survey was conducted to determine perceptions and attitudes of psychiatric services available to nursing homes and homes for the aged across Ontario. A questionnaire was sent by mail to medical and nursing directors separately. Thirty-six point eight percent of responders reported that the nursing home residents never receive psychiatric care, and 88.2% of responders estimated the total psychiatric care received by all of their residents per month was five hours or less. Almost three-quarters of the responders stated that they require more psychiatric services. Significantly more nursing directors than medical directors wanted more psychiatric services. Southwestern Ontario, followed by Northern Ontario, had the least perceived availability of a visiting psychiatrist. Perceived availability was greatest in larger urban areas and least in rural areas. The mean percentage of residents perceived to have psychiatric or behavioural problems was 30.5%, while the mean percentage perceived to require psychotropic medication was 37.4%. Physical aggression, wandering and agitation were identified as the behavioural problems of greatest concern to staff. When a visiting psychiatrist is not available, residents sometimes have to travel long distances for psychiatric evaluation. Planning is required to facilitate and encourage the development of efficient and effective psychiatric services for long term care facilities for the elderly.

Aged↗
PubMed1992

Urinary eicosanoids and the assessment of glomerular inflammation.

Nephrotoxic nephritis, a model system for glomerulonephritis, is characterized by glomerular inflammation, proteinuria, and a marked increase in ex vivo glomerular eicosanoid production. This study addressed whether urinary eicosanoids might serve as noninvasive markers for glomerular inflammation and damage with nephrotoxic nephritis and its accelerated variant. Accelerated nephritis, relative to simple nephritis, was characterized by more substantial glomerular inflammation, particularly that due to neutrophils. Correspondingly, accelerated nephritis was accompanied by greater proteinuria and more marked elevations in glomerular eicosanoids generated ex vivo. With respect to urinary eicosanoids, thromboxane, but not leukotriene B4, was detected in the urine of normal animals. After the induction of nephrotoxic nephritis, urinary thromboxane was moderately elevated (twofold) and urinary leukotriene B4 was variably present (three of seven animals). In accelerated nephritis, urinary thromboxane was more markedly elevated (sixfold) and leukotriene B4 was consistently present. The presence of urinary leukotriene B4 was confirmed by gas chromatography/mass spectrometry. Urinary eicosanoids together correlated with glomerular leukocyte numbers and proteinuria by linear regression. Urinary leukotriene B4 individually correlated with glomerular neutrophil numbers. Renal metabolism of leukotriene B4 to omega oxidation products by the rat kidney was not apparent. These data validate that the enhanced glomerular eicosanoid metabolism seen in nephrotoxic nephritis takes place in vivo and additionally suggest that both urinary thromboxane and leukotriene B4 may serve as noninvasive markers for glomerular inflammation and damage. In light of these and prior studies, urinary thromboxane may be a general marker of glomerular inflammation and leukotriene B4 may be a more specific index of acute inflammation.

Animals↗
PubMed1991

Treatment of septic thrombocytopenia with immune globulin.

Thrombocytopenia frequently complicates systemic infection and results from multiple possible mechanisms. We and others have demonstrated that platelet-associated IgG (PAIgG) levels are elevated in the majority of patients with septic thrombocytopenia. Corticosteroids may be undesirable as a treatment for thrombocytopenia for patients with severe infection because of their potential for suppressing the immune response. We hypothesized that septic thrombocytopenia is, in most cases, an immune disorder analogous to idiopathic thrombocytopenic purpura (ITP) which might respond to intravenous gamma-globulin as a treatment for increasing the platelet count in this disorder. Intravenous immune globulin (IVIG), 400 mg/kg daily for 3 days, was administered in a randomized double-blind placebo-controlled trial. Twenty-nine patients who developed thrombocytopenia during a documented, septic episode were studied. Patients with disseminated intravascular coagulation (DIC), hypersplenism, or drugs known to cause thrombocytopenia were excluded. Elevated PAIgG levels were documented in 52% of evaluable patients. Mean platelet counts in the IVIG group rose from 43K at study entry to 178K (411% rise) by Day 9. In the placebo group platelets rose from 51K to 125K (261% rise; P = 0.02). Seventy-seven percent of the IVIG group had a minimum peak rise of 35K, vs 56% of the placebo group. Three patients in the placebo group had a serious bleeding episode, vs one in the IVIG group. The use of IVIG to treat septic thrombocytopenia not associated with DIC leads to a more rapid, more sustained, and greater increase in platelet count than placebo. Its use is recommended in the septic patient who is bleeding or is likely to need invasive or surgical procedures.

Blood Platelets↗
PubMed1991

Extensor indicis proprius opponensplasty.

An analysis of 39 patients (40 hands) who underwent an extensor indicis proprius opponensplasty was carried out. Of these, 29 hands had simultaneous adjuvant surgery to correct other deformities. The mean follow-up period was 33.8 months. Excellent or good results were seen in 87.5%, fair in 10% and poor in 2.4% hands.

Adolescent↗
PubMed1991

A rare-event analysis model for quantifying white cells in white cell-depleted blood.

An analysis model to detect and quantify white cells (WBCs) in red cell concentrates (RBCC) drawn from units of blood that are highly depleted of WBCs is described. WBC detection is performed by fluorescence analysis of 50 microL of RBCC labeled with propidium iodide, a DNA/RNA fluorophore. Quantification is performed by regression analysis of standard dilutions of RBCC in substantially WBC-free red cells. This RBCC diluent is obtained by filtration of blood through a new medium. The method proves to be precise (CV = 7%), efficient (+/- 30 min/aliquot), and linear (r = 0.99) to 6 log10 WBC depletion of the native product. The current technique is preferable to those suggested previously, such as ficoll concentration, which requires the sacrifice of the unit of blood for counting purposes, and to earlier fluorescence analysis techniques that do not employ WBC-free red cell diluents. The latter do not monitor extremely low concentrations of WBCs because they lack adequate signal-to-noise discrimination. The sensitivity of the described method allows for monitoring of WBC depletion procedures with greater efficiency than is currently available commercially.

Blood Component Removal↗
PubMed1991

DNA methylation in specific cells of rat liver by N-nitrosodimethylamine and N-nitrosomethylbenzylamine.

Dose-response curves for the O6-methylation of guanine in the hepatic DNA of Wistar and Sprague-Dawley rats were determined after administration of N-nitrosomethylbenzylamine (NMBzA) or N-nitrosodimethylamine (NDMA). Similar results were obtained for both rat strains but methylation of hepatic DNA by NDMA was approximately 9-fold more efficient than with NMBzA when doses were compared on a molar basis. Comparison by immunohistochemical analysis of the distribution of nuclei containing O6-methylguanine within the liver lobules showed that both agents tended to alkylate cells close to the central veins at the lower doses. With increasing doses, the band width of alkylated cells around the central vein increased, spreading in the case of NDMA virtually into the portal zones, whereas with NMBzA the zone of alkylated nuclei reached little more than halfway from the central vein to the portal zone. These differences in the distribution of alkylated cells may explain the differing hepatic responses to these two nitrosamines.

Animals↗
PubMed1991

Adriamycin-induced myocardial dysfunction in vitro is mediated by free radicals.

The role of free radicals in adriamycin (Adr)-induced acute myocardial changes was examined by using different antioxidants. Exposure of papillary muscles to Adr (100 microM) in a tissue bath for 60 min reduced developed force by 42%, increased lipid peroxidation by 200%, and resulted in characteristic ultrastructural changes. Catalase (4 x 10(4) U/l), an enzyme effective in the hydrolysis of hydrogen peroxide (H2O2), was more effective in maintaining the developed force than mannitol (20 mM), a hydroxyl radical scavenger. A small protection of developed force seen with superoxide dismutase (1.2 x 10(5) U/l), a quencher of superoxide radical, was evident for the first 15 min only. Only catalase and mannitol showed significant protection against Adr-induced increase in lipid peroxidation. Ultrastructural changes due to Adr alone included mitochondrial swelling, intramitochondrial granules, vacuolization, and disruption of sarcomeres. All of these changes were reduced in the presence of both catalase and mannitol, whereas superoxide dismutase was without any effect. Complete structural or functional protection was not seen with any of the antioxidants used in the study. Although both H2O2 and hydroxyl radical appear to be involved in Adr-induced deleterious effects, data on developed force also indicate that H2O2 may have a major role in mediating the acute effects of Adr in vitro.

Animals↗
PubMed1991

Dietary fiber in hospitalized geriatric patients: too soft a solution for too hard a problem?

Increased fiber in the diet has been shown in the past to improve bowel function in elderly outpatients and in long-term care institutions. A randomized placebo-controlled, double-blind study was conducted in a geriatric ward of an acute-care hospital to see if a palatable form of fiber would decrease the incidence of constipation and use of laxatives. In this patient sample, no beneficial effect of fiber supplementation could be found when used up to three weeks.

Aged↗