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Biomedical subjects

G Morrow

Publications and source records attributed to G Morrow.

At least 19 recordsLinked to original sources
PubMed2001

Varicella-zoster virus infection of human dendritic cells and transmission to T cells: implications for virus dissemination in the host.

During primary varicella-zoster virus (VZV) infection, it is presumed that virus is transmitted from mucosal sites to regional lymph nodes, where T cells become infected. The cell type responsible for VZV transport from the mucosa to the lymph nodes has not been defined. In this study, we assessed the susceptibility of human monocyte-derived dendritic cells to infection with VZV. Dendritic cells were inoculated with the VZV strain Schenke and assessed by flow cytometry for VZV and dendritic cell (CD1a) antigen expression. In five replicate experiments, 34.4% +/- 6.6% (mean +/- SEM) of CD1a(+) cells were also VZV antigen positive. Dendritic cells were also shown to be susceptible to VZV infection by the detection of immediate-early (IE62), early (ORF29), and late (gC) gene products in CD1a(+) dendritic cells. Infectious virus was recovered from infected dendritic cells, and cell-to-cell contact was required for transmission of virus to permissive fibroblasts. VZV-infected dendritic cells showed no significant decrease in cell viability or evidence of apoptosis and did not exhibit altered cell surface levels of major histocompatibility complex (MHC) class I, MHC class II, CD86, CD40, or CD1a. Significantly, when autologous T lymphocytes were incubated with VZV-infected dendritic cells, VZV antigens were readily detected in CD3(+) T lymphocytes and infectious virus was recovered from these cells. These data provide the first evidence that dendritic cells are permissive to VZV and that dendritic cell infection can lead to transmission of virus to T lymphocytes. These findings have implications for our understanding of how virus may be disseminated during primary VZV infection.

Antigens, CD1↗
PubMed2001

Evaluation for Hsp70 as a biomarker of effect of pollutants on the earthworm Lumbricus terrestris.

Induction of heat shock proteins (Hsps) is often associated with a cellular response to a harmful stress or to adverse life conditions. The main aims of the present study were (1) to assess if stress-induced Hsp70 could be used to monitor exposure of the earthworm species Lumbricus terrestris to various soil pollutants, (2) to assess the specificity of pollutants in their tissue targeting and in Hsp70 induction, and (3) to evaluate if dose-response relationships could be established and if the stress-response observed was specific. The midgut/intestinal tissues of L. terrestris are shown to express an inducible member of the Hsp70 family after heat shock treatment in vitro and exposures to different soil toxicants in vivo (re: artificial soil). Short-term (24-72 hours) and long-term (14-16 days) exposures to the chemical standards chloroacetamide and pentachlorophenol and to heavy metals (Pb++, Cd++, Cu++, and Hg++) also affected the earthworms, and Hsp70 was induced in their midgut/intestinal tissues. After a 3-day exposure to heavy metals, the level of Hsp70 induction in the midgut/intestinal tissues appears to correlate well with the reported in vivo and in vitro toxicity data. Comparatively, in proximal and midbody wall muscle tissues of animals exposed to the heavy metals, a decrease in expression of Hsp70 was sometimes detected. Thus Hsp analysis by Western blot in L. terrestris tissues and particularly in the midgut/intestine proved to be a suitable and sensitive assay for adverse effects in earthworms and showed a good level of reproducibility despite some individual variations. The use of pristine/nonexposed animals transposed into contaminated environments as in the present study should therefore be of high ecological relevance. Induction of Hsp70 in earthworms should represent not only a good wide-spectrum biomarker of exposure but also a biomarker of effect since known toxicants altered gene expression in tissues of these animals, as contrasted with a simple accumulation of Hsp. Hence, the detection of Hsp70 in earthworms can constitute an early-warning marker for the presence of potentially deleterious agents in soils, with L. terrestris in particular and earthworms in general acting as potential sentinel animal species.

Acetamides↗
PubMed2000

The small heat shock protein Hsp22 of Drosophila melanogaster is a mitochondrial protein displaying oligomeric organization.

Drosophila melanogaster has four main small heat shock proteins (Hsps), D. melanogaster Hsp22 (DmHsp22), Hsp23 (DmHsp23), Hsp26 (DmHsp26), and Hsp27 (DmHsp27). These proteins, although they have high sequence homology, show distinct developmental expression patterns. The function(s) of each small heat shock protein is unknown. DmHsp22 is shown to localize in mitochondria both in D. melanogaster S2 cells and after heterologous expression in mammalian cells. Fractionation of mitochondria indicates that DmHsp22 resides in the mitochondrial matrix, where it is found in oligomeric complexes, as shown by sedimentation and gel filtration analysis and by cross-linking experiments. Deletion analysis using a DmHsp22-EGFP construct reveals that residues 1-17 and an unknown number of residues between 17-28 are necessary for import. Site-directed mutagenesis within a putative mitochondrial motif (WRMAEE) at positions 8-13 shows that the first four residues are necessary for mitochondrial localization. Immunoprecipitation results indicate that there is no interaction between DmHsp22 and the other small heat shock proteins. The mitochondrial localization of this small Hsp22 of Drosophila and its high level of expression in aging suggests a role for this small heat shock protein in protection against oxidative stress.

Amino Acids↗
PubMed2000

Mitochondrial DNA depletion in children.

The first girl of an unrelated couple was noted to have failure to thrive since age 3 months, generalized hypotonia and weakness, hepatomegaly, hypoglycemia, and lactic acidosis at 4 months. She was found to have severe mitochondrial DNA (mtDNA) depletion and respiratory chain complex IV deficiency in both skeletal muscle and liver but without other common mtDNA mutations. Her younger brother developed vomiting at age 3 weeks and was diagnosed as having pyloric stenosis. His skeletal muscle and liver also showed severe mtDNA depletion. He developed generalized weakness and hypotonia, hepatomegaly, and lactic acidosis at age 3 months. Both siblings died of hepatic failure and hemorrhagic complication before 6 months of age. The brother also had chemical pancreatitis, which had not been reported before in mtDNA depletion in children. Severe mtDNA depletion may present with nonspecific symptoms such as vomiting, failure to thrive, and developmental delay; multiorgan involvement such as hepatomegaly, pancreatitis, and myopathy occurs later. Mitochondrial DNA depletion should be considered in the differential diagnosis in children with developmental delay or failure to thrive of unknown etiology.

DNA Fragmentation↗
PubMed1998

Expression of heat shock proteins in mouse skin during wound healing.

Wound healing conditions generate a stressful environment for the cells involved in the regeneration process and are therefore postulated to influence the expression of heat shock proteins (Hsps). We have examined the expression of four Hsps (Hsp27, Hsp60, Hsp70 and Hsp90) and a keratin (keratin 6) by immunohistochemistry during cutaneous wound repair from Day 1 to Day 21 after wounding in the mouse. Hsps were constitutively expressed in normal mouse epidermis and their patterns of expression were modified during the healing process. The changes were not directly linked to the time course of the healing process but rather were dependent on the location of cells in the regenerating epidermis. In the thickened epidermis, Hsp60 was induced in basal and low suprabasal cells, Hsp70 showed a reduced expression, and Hsp90 and Hsp27 preserved a suprabasal pattern with an induction in basal and low suprabasal cells. All Hsps had a uniform pattern of expression in the migrating epithelial tongue. These observations suggest that the expression of Hsps in the neoepidermis is related to the proliferation, the migration, and the differentiation states of keratinocytes within the wound.

Animals↗
PubMed1997

Effectiveness of a training program for enhancing therapists' understanding of the supportive-expressive treatment model for breast cancer groups.

This study evaluated a training program for leaders of supportive-expressive psychotherapy groups for breast cancer patients. Twenty-four mental health/medical cancer care professionals completed two training phases and were tested for their understanding of the treatment model. Participants' understanding was enhanced as a result of the training program. This study demonstrates that a brief training program can improve therapists' understanding of the treatment model and demonstrates an effective method of evaluation. Future research should examine how performance on these tests generalizes to performance when leading a supportive-expressive group.

Adult↗
PubMed1993

The role of computed tomography and sonography in acute bullous pemphigoid.

We report acute bullous pemphigoid occurring in an elderly female patient in whom abdominal sonography and computed tomography (CT) examinations revealed the presence of occult hepatic and splenic metastatic deposits from a primary pancreatic carcinoma. In the majority of cases bullous pemphigoid is a self limiting auto-immune disorder occurring in the absence of systemic disease. An association with visceral malignancy has been described by previous authors but the role of computed tomography and sonography in diagnosing occult malignancy and the subgroup of patients with pemphigoid in whom this should be undertaken has not been highlighted.

Aged↗
PubMed1992

Mandatory testing?

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AIDS Serodiagnosis↗