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Biomedical subjects

J Hudson

Publications and source records attributed to J Hudson.

At least 19 recordsLinked to original sources
PubMed1997

Safety and immunogenicity of UBI HIV-1MN octameric V3 peptide vaccine administered by subcutaneous injection.

Twenty-four HIV-seronegative men, at high risk of HIV infection, were recruited into a phase I/II safety and immunogenicity trial of a prototype HIV vaccine. The immunogen was a synthetic, monovalent, octameric HIV-1MN V3 peptide in an aluminum hydroxide (alum) adjuvant. The vaccine had been evaluated previously using a standard 0-, 1-, 6-month intramuscular schedule and was found to stimulate neutralizing antibody in 60-90% of volunteers. Participants were randomized to receive either 500 micrograms (n = 10; high dose) or 100 micrograms (n = 10; low dose) of immunogen or placebo (alum alone; n = 4) at 0, 1, and 6 months by subcutaneous injection. Responses to the immunogen were evaluated by enzyme-linked immunosorbent assay (ELISA)-detectable antibody and by proliferative responses. Safety was monitored by both clinical assessment and regular review with a clinical psychologist. No serious adverse experiences were observed following administration of the assigned medication. One individual (placebo) seroconverted while on study, following exposure to HIV. After the vaccination course only four individuals (three high dose and one low dose) had ELISA-detectable antibody against the immunogen. In the evaluable samples, from 19 volunteers, only 7 vaccine recipients (3 high dose and 4 low dose) had demonstrable lymphoproliferative responses to preparations of the immunogen. Subcutaneous administration of its candidate vaccine was safe but did not result in uniform or robust immunological responses.

AIDS Vaccines↗
PubMed1996

Antibody ligation of CD9 modifies production of myeloid cells in long-term cultures.

The KMC8.8 monoclonal antibody was made by immunizing rats with the BMS2 stromal cell clone, and was selected for further study because its ability to inhibit production of myeloid cells in Dexter cultures but not that of lymphoid cells in Whitlock-Witte cultures. The influence on myeloid progenitors might have been indirect, since the antibody did not prevent responsiveness to colony-stimulating factors in semisolid agar cultures. Furthermore, there was no inhibition, and some augmentation, of cell production when the antibody was added to established Dexter cultures. A cDNA clone that encoded the KMC8.8-recognized molecule was isolated by expression cloning and found to be identical in sequence to a previously published murine CD9 homologue. The antibody and cDNA clone were used to establish that CD9 is expressed by stromal cells, megakaryocytes, platelets, myeloid cells, and subpopulations of mature lymphocytes in mice. Treatment with the KMC8.8/CD9 antibody slightly augmented adhesion between myeloid cells and stromal cells, consistent with previous reports that this member of the tetraspan family of proteins can transmit proadhesive signals to human platelets and lymphoid cells. CD9 might participate in cell-cell interactions critical for correct orientation and movement of maturing myeloid cells in bone marrow.

Animals↗
PubMed1996

Effect of ultraviolet-B light on lymphocyte activity at doses at which normal bone marrow stem cells are preserved.

Ultraviolet B (UVB) light is known to be immunosuppressive, but, probably because of a small UVC component in the emission spectra of some of the UVB lamps used, reports vary on effective dose levels. To prevent potentially lethal graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation, alloreactive donor T-cell activity must be suppressed. In this study, a narrow wavelength UVB lamp (TL01, 312 nm peak emission) was used to determine what doses of UVB were required to abolish rat lymphocyte proliferation while simultaneously preserving rat bone marrow progenitor cell and primitive hematopoietic stem cell viability. Lymphocyte proliferation, as measured by 3H-Thymidine incorporation, in response to lectin stimulation was abolished below detection at doses greater than 3,500 J/m2. When T-cell clonogenicity was measured in a limiting dilution assay, a small fraction (0.6%) was maintained at doses up to 4,000 J/m2. Cytotoxic T-lymphocyte (CTL) activity was reduced after treatment with 4,000 J/m2, but a significant level of cytotoxicity was still maintained. Natural killer cell cytolytic activity was not affected by doses up to 4,000 J/m2. At 4,000 J+m2 there was a 10% survival of colony-forming units-granulocyte-macrophage; a 1% and 4% survival of day-8 and day-12 colony-forming units-spleen, respectively; and 11% survival of marrow repopulating ability cells. Up to 25% of late cobblestone area forming cells (4 to 5 weeks), reflecting the more immature hematopoietic stem cells, were preserved in bone marrow treated with 4,000 J/m2, indicating that early stem cells are less sensitive to UVB damage than are more committed progenitor cells. Thus, a potential therapeutic window was established at approximately 4,000 J/m2 using this light source, whereby the potentially GVHD-inducing T cells were suppressed, but a sufficient proportion of the cells responsible for engraftment was maintained.

Animals↗
PubMed1996

In vivo electrochemical studies of dopamine overflow and clearance in the striatum of normal and MPTP-treated rhesus monkeys.

Rapid chronoamperometric recordings, using Nafion-coated carbon-fiber electrodes (30-90 microns o.d.), were used to investigate overflow and uptake of dopamine (DA) in the striatum of normal and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated rhesus monkeys. The monkeys were anesthetized with isoflurane and placed in a stereotaxic apparatus. Magnetic resonance imaging-guided sterile stereotaxic procedures were used for implantations of the electrochemical electrodes coupled with single-barrel micropipettes that were used to apply potassium or DA locally. Potassium evoked a robust overflow of DA-like electrochemical signals into the brain extracellular space in the unlesioned or normal putamen and caudate nucleus of the rhesus monkeys. In contrast, potassium did not produce any detectable changes (> 97% depletion) of DA in the MPTP-lesioned striatum. In addition, the diffusion/clearance of locally applied DA was markedly altered in the lesioned caudate nucleus and putamen compared with unlesioned striatum. Cell counts of the number of residual tyrosine hydroxylase-positive neurons in MPTP-treated monkeys, in conjunction with whole-tissue levels of DA and its metabolites, showed that the MPTP lesions produced extensive damage of the nigrostriatal DA system. These data indicate that residual dopaminergic fibers remaining after MPTP lesions are dysfunctional and have a greatly diminished capacity for high-affinity DA uptake.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1996

PCR amplification of short tandem repeat sequences allows serial studies of chimaerism/engraftment following BMT in rodents.

Animal models of bone marrow transplantation (BMT) allow evaluation of new experimental treatment strategies. One potential strategy involves the treatment of donor marrow with ultra-violet B light to allow transplantation across histocompatibility boundaries without an increase in graft rejection or graft-versus-host disease. A major requirement for a new experimental protocol, particularly if it involves manipulation of the donor marrow, is that the manipulated marrow gives rise to long-term multilineage engraftment. DNA based methodologies are now routinely used by many centres to evaluate engraftment and degree of chimaerism post-BMT in humans. We report the adaptation of this methodology to the serial study of engraftment in rodents. Conditions have been defined which allow analysis of serial tail vein samples using PCR of short tandem repeat sequences (STR-PCR). These markers have been used to evaluate the contribution of ultraviolet B treated marrow to engraftment following BMT in rodents without compromising the health of the animals under study. Chimaerism data from sequential tail vein samples and bone marrow from selected sacrificed animals showed excellent correlation, thus confirming the validity of this approach in analysing haemopoietic tissue. Thus the use of this assay may facilitate experimental studies in animal BMT.

Animals↗
PubMed1996

Severity of radiographic findings in hip osteoarthritis associated with total hip arthroplasty.

OBJECTIVE: The decision to perform total hip arthroplasty (THA) in patients with osteoarthritis (OA) of the hip is based largely on patients' reports of pain and disability and not on radiographic findings of OA. We determine the severity of radiographic OA and its association with disability in patients undergoing THA. METHODS: Individual radiographic features (osteophytes, joint space narrowing, sclerosis, cysts, deformity) and global severity of hip OA were assessed in 95 consecutive elderly patients with hip OA undergoing THA who were enrolled in a Patient Outcome Research Team (PORT) project. RESULTS: Eighty-seven patients (91.5%) had either severe or moderate OA in the hip to be replaced; 17% of these had a previous contralateral THA. Only 8 patients (8.4%) had mild or no signs of OA in the hip to be replaced and 4 (50%) of these patients had their opposite hip replaced previously. CONCLUSION: These data indicate that radiographic features of moderate to severe hip OA are associated with clinical findings and the necessity to perform THA in the majority of patients. Patients who have had a prior hip replacement, however, may be more likely to have a contralateral replacement done earlier (p = 0.03), before radiographic signs are evident.

Aged↗
PubMed1995

Glial cell line-derived neurotrophic factor augments midbrain dopaminergic circuits in vivo.

Recently, a novel glial cell line-derived neurotrophic factor (GDNF) has been identified, cloned, and shown to have potent survival- and growth-promoting activity on fetal rat midbrain dopaminergic neurons in cell culture. In this study, we document marked and long-lasting effects on adult rat midbrain dopaminergic neurons in vivo after intracranial administration. A single injection of this factor into the substantia nigra elicited a dose-dependent increase in both spontaneous and amphetamine-induced motor activity, and a decrease in food consumption, lasting 7-10 days. Using immunocytochemistry, we found sprouting of tyrosine hydroxylase-positive neurites towards the injection site, and increased tyrosine hydroxylase immunoreactivity of the ipsilateral striatum was produced by GDNF. There was also a marked and dose-dependent increase in dopamine turnover in the substantia nigra and striatum, and in ipsilateral dopamine levels in the substantia nigra. Little or no effects of GDNF were seen on norepinephrine or serotonin levels. The neurochemical changes on dopaminergic afferents persist for at least 3 weeks after a single intracranial injection of 10 micrograms. Taken together, these data suggest that this glial cell line-derived factor has a potent influence on adult rat dopamine neurons and may have a potentially important role as a trophic factor for these neurons.

Animals↗
PubMed1994

Glial cell line-derived neurotrophic factor reverses toxin-induced injury to midbrain dopaminergic neurons in vivo.

Fischer 344 rats were unilaterally injected into the medial forebrain bundle with 6-hydroxydopamine (6-OHDA). Apomorphine-induced rotational behavior was used to select animals whose rotation exceeded 300 turns/h, corresponding to greater than 95% dopamine (DA) depletion in the ipsilateral striatum. Four weeks later, glial cell line-derived neurotrophic factor (GDNF) or vehicle was injected intranigrally ipsilateral to the lesion (0.1-100 micrograms). The highest dose of GDNF tested produced a marked decrease in rotational behavior. This dose also produced levels of DA in the ipsilateral substantia nigra (SN) which were not statistically different from the contralateral side. Vehicle-treated animals showed a marked DA depletion in the ipsilateral SN. These results demonstrate neurochemical and behavioral improvements in unilaterally DA-lesioned rats following intranigral administration of GDNF, suggesting that GDNF may develop into a useful therapy for Parkinson's disease.

Animals↗
PubMed1993

Alternatively spliced pp52 mRNA in nonlymphoid stromal cells.

The 52-kDa phosphoprotein, also reported as lymphocyte-specific gene 1 and WP34, is transcribed as a 1.6-kb mRNA in B lymphocytes, B cell lines, and untransformed T cells. This gene encodes a cytoplasmic and plasma membrane-associated protein that is phosphorylated at a casein kinase II site and reportedly binds calcium. Based on these properties, it has been hypothesized that lymphoid form of the 52-kDa phosphoprotein protein may play a role in lymphocyte signal transduction. We show that alternatively spliced mRNA are expressed from this gene in nonlymphoid cell lines (myocytes, stromal cells, fibroblasts). These cell lines do not express the 1.6-kb lymphoid cell-specific transcript. Instead, mRNA of 2.0 and 2.8 kb are detected in varying abundance. A full-length 2.0-kb cDNA has been cloned and sequenced from the BMS2 stromal cell line by conventional screening and polymerase chain reaction-based methods. This cDNA clone, designated S37, has a single open reading frame encoding a 328 amino acid peptide. The nucleotide sequence of the S37 stromal cell cDNA is identical to that of the lymphocyte derived pp52 cDNA from the 3' poly(A) tail to the codon encoding the amino acid at residue 24. This region of the S37 cDNA clone encodes a protein that is identical to that encoded by the lymphoid pp52 cDNA and includes a casein kinase II phosphorylation site. However, the two clones differ in their 5' nucleotide sequence and their NH3 terminal amino acid sequence. This organization is consistent with alternative exon utilization. These results suggest that tissue-specific control mechanisms are used to generate different forms of lymphoid form of the 52-kDa phosphoprotein mRNA in lymphoid cells versus mesoderm-derived, nonlymphoid cell lineages.

Alternative Splicing↗
PubMed1993

Osteoblastic gene expression during adipogenesis in hematopoietic supporting murine bone marrow stromal cells.

A growing body of data suggests that the bone marrow stroma contains a population of pluripotent cells capable of differentiating into adipocytes, osteoblasts, and lymphohematopoietic supporting cells. In this work, the murine stromal cell lines BMS2 and +/+ 2.4 have been examined as preadipocytes and adipocytes for evidence of osteoblastic gene expression. Adipocyte differentiation has been quantitated using fluorescence activated cell sorting. Within 7-10 days of adipocyte induction by treatment with glucocorticoids, indomethacin, and methylisobutylxanthine, between 40% to 50% of the cells contain lipid vacuoles and exhibit a characteristic adipocyte morphology. Based on immunocytochemistry, both the adipocytes and preadipocytes express a number of osteoblastic markers; these include alkaline phosphatase, osteopontin, collagen (I, III), bone sialoprotein II, and fibronectin. Based on biochemical assays, the level of alkaline phosphatase expression is not significantly different between preadipocyte and adipocyte cells. However, unlike rat cell lines, dexamethasone exposure causes a dose-dependent decrease in enzyme activity. The steady-state mRNA levels of the osteoblast associated genes varies during the process of adiopogenesis. The relative level of collagen I and collagen III mRNA is lower in adipocyte-induced cells when compared to the uninduced controls. Osteocalcin mRNA is detected in preadipocytes but absent in adipocytes. These data indicate that osteoblastic gene expression is detected in cells capable of undergoing adipocyte differentiation, consistent with the hypothesis that these cell lineages are interrelated.

Adipose Tissue↗
PubMed1993

Requirements for Langerhans' cell depletion following in vitro exposure of murine skin to ultraviolet-B.

Langerhans' cells found within the skin and mucous membranes are critical regulators of antimicrobial and allergic responses. Therefore, the depletion of these cells following exposure of skin to solar ultraviolet radiation (UV) has direct functional consequences on immunity within this tissue. In order to understand how Langerhans' cell depletion is regulated following exposure of skin to medium-wave UV (UVB), the role of second messengers in these responses was investigated using a novel in vitro system. This was accomplished by analysing the expression of a specific marker associated with Langerhans' cells (ATPase) among the epidermal portion of cultured sections of mouse skin following treatment with inhibitors specific for second messenger components and subsequent exposure to UVB. In this study, inhibitors of guanosine triphosphate (GTP) binding proteins, H-8, pertussis toxin and cholera toxin as well as inhibitors of RNA and protein synthesis were all capable of blocking Langerhans' cell depletion in response to UVB treatment. In contrast, an inhibitor of protein kinase C (H-7) was incapable of specifically blocking depletion following treatment with this physical agent. These results suggest that Langerhans' cell depletion mediated by UVB may involve a pertussis and cholera toxin-sensitive G protein as well as de novo protein synthesis.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1993

Modulation of lymphohematopoiesis in long-term cultures by gamma interferon: direct and indirect action on lymphoid and stromal cells.

Gamma interferon (IFN-gamma) is the product of multiple cell types within the bone marrow microenvironment and has been demonstrated to act as a potent inhibitor of myelopoiesis in vitro and in vivo. The action of this cytokine on lymphohematopoiesis has now been examined on both long-term bone marrow cultures and representative cloned cellular components of the bone marrow microenvironment. In myelopoietic (Dexter) cultures, the half maximal inhibitory concentration of IFN-gamma was between 1 and 10 U/mL. In comparable lymphopoietic (Whitlock/Witte) cultures, IFN-gamma inhibited the production of B-lineage lymphoid cells with a half maximal effective concentration of less than 1 U/mL. In a clonal assay for pre-B cells, IFN-gamma inhibited colony formation with a half maximal concentration of 1 to 5 U/mL. Not all B-lineage lymphoid cells displayed the same sensitivity, however. Growth of the IL-7-dependent B cell line (2E8) in methylcellulose assays was unaffected by IFN-gamma while the replication of other lymphoid lines was partially or completely inhibited. IFN-gamma induced the expression of cell surface proteins (MHC Class I and II) on both B-lineage cells and stromal cells. In cloned stromal cell lines, IFN-gamma increased the steady state mRNA levels for the cytokines interleukin-6 (IL-6) and JE, a member of the IL-8 family. These data indicate that IFN-gamma acts within the lymphohematopoietic microenvironment through both direct and indirect actions on the hemopoietic and stromal cell populations.

Animals↗
PubMed1992

The wee1 protein kinase is required for radiation-induced mitotic delay.

Cellular feedback or 'checkpoint' mechanisms maintain the order of completion of essential, cell-cycle related functions. In the budding yeast, for example, the RAD9 gene product is required to delay progression into mitosis in response to DNA damage. Similarly, in fission yeast, the cdc25 and cdc2 gene products influence the ability of cells to delay mitosis in response to the inhibition of DNA synthesis. Because these two checkpoint controls regulate the same event, mitosis, we observed the effect of gamma-irradiation on cell cycle progression in fission yeast, to test whether the two controls require the same cell-cycle regulatory elements. We show that gamma-radiation-induced mitotic delay requires functional wee1 protein kinase but does not seem to involve the cdc25 pathway. Mitotic delay in response to DNA damage is thus distinct from the delay induced by inhibition of DNA synthesis, which involves cdc25 but is not dependent on wee1.

Cell Cycle Proteins↗
PubMed1992

A phase I trial of recombinant human macrophage colony-stimulating factor by rapid intravenous infusion in patients with refractory malignancy.

Twenty patients with advanced cancer for which there was no effective standard therapy or whose disease was refractory to standard therapy were treated with recombinant macrophage colony-stimulating factor (rM-CSF). The rM-CSF was administered by intravenous bolus infusion for 5 consecutive days every other week for 2 treatment weeks. The doses administered ranged from 30 to 33,000 micrograms/m2/day. There was no intrapatient dose escalation. There were minimal to no systemic side effects seen, except for acute dyspnea noted in three patients. The dyspnea was felt to be related to the rate of infusion and did not recur in one patient given additional rM-CSF at a slower infusion rate. The major hematologic effect seen was a mild decrease in platelet count, which began to recover while the patients continued to receive the rM-CSF. The clearance of rM-CSF was dose dependent. Lower doses resulted in a saturable mechanism felt to represent cellular uptake. Clearance at higher doses demonstrated both a first-order mechanism at high serum rM-CSF concentrations, representing renal clearance, as well as a saturable mechanism at low serum concentrations. The maximum mean serum half-life was reached at dose levels of greater than or equal to 3,690 micrograms/m2 and was in the range of 234-258 min. By this route of administration, rises in absolute monocyte count were slight and seen only at doses of greater than or equal to 450 micrograms/m2 during the second therapy week. The maximum tolerated dose was not reached in this study because of lack of availability of rM-CSF.

Adult↗