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Biomedical subjects

M Varney

Publications and source records attributed to M Varney.

At least 19 recordsLinked to original sources
PubMed2001

Immunization with wild-type p53 gene sequences coadministered with Flt3 ligand induces an antigen-specific type 1 T-cell response.

We examined the ability of immunization with sequential adenovirus/plasmid DNA vectors expressing human wild-type p53 to stimulate a type 1 T-cell response and induce protection against challenge from a metastatic tumor that expresses mutated murine p53. We found that tumor protection and an antigen (Ag)-specific immune response were enhanced by prior injection of Flt3 ligand (Flt3L) at a dose and schedule that significantly increased dendritic cell (DC) number and frequency. Preliminary studies using enzyme-linked immunospot and Winn assays suggested that Ag-specific CD8 cells, with their significant increase in IFN-gamma-secreting activity (Tc1 cells), were responsible for the tumor protection. The delayed-type hypersensitivity response to p53 was increased in mice immunized with p53 alone or p53 and Flt3L compared with a negative control. In contrast, spleen cells from mice immunized with p53 and Flt3L exhibited a higher Ag-specific proliferative response than mice immunized with p53 alone. The frequencies of Ag-specific IFN-gamma and interleukin (IL)-4-secreting cells were determined using an enzyme-linked immunospot assay, which demonstrated that the frequency of IFN-gamma-secreting cells was significantly higher in mice immunized with p53 and Flt3L than in mice receiving Flt3L, excipient, or p53 treatment alone. In contrast, the frequency of IL-4-secreting cells did not differ significantly among these groups. We also observed an increased frequency of IL-12 and IFN-gamma-secreting cells (but not IL-4 or IL-10) in the spleens of mice immediately after 10 days of Flt3L treatment, which was also the day of p53 priming. This observation supports the likelihood that there are multiple mechanisms of Flt3L adjuvant activity, including expansion of DC and type 1 T-cell number. Overall, these results suggest that immunization with p53 genetic sequences after in vivo expansion of DC, using Flt3L, provides a useful strategy to induce p53-specific, and protective, type 1 T-cell responses.

Adenoviridae↗
PubMed2001

Metabotropic glutamate receptor subtype 5 (mGlu5) and nociceptive function. I. Selective blockade of mGlu5 receptors in models of acute, persistent and chronic pain.

The excitatory neurotransmitter, glutamate, is particularly important in the transmission of pain information in the nervous system through the activation of ionotropic and metabotropic glutamate receptors. A potent, subtype-selective antagonist of the metabotropic glutamate-5 (mGlu5) receptor, 2-methyl-6-(phenylethynyl)-pyridine (MPEP), has now been discovered that has effective anti-hyperalgesic effects in models of inflammatory pain. MPEP did not affect rotarod locomotor performance, or normal responses to noxious mechanical or thermal stimulation in naïve rats. However, in models of inflammatory pain, systemic administration of MPEP produced effective reversal of mechanical hyperalgesia without affecting inflammatory oedema. In contrast to the non-steroidal anti-inflammatory drugs, indomethacin and diclofenac, the maximal anti-hyperalgesic effects of orally administered MPEP were observed without acute erosion of the gastric mucosa. In contrast to its effects in models of inflammatory pain, MPEP did not produce significant reversal of mechanical hyperalgesia in a rat model of neuropathic pain.

Animals↗
PubMed2001

Flt3 ligand and granulocyte-macrophage colony-stimulating factor preferentially expand and stimulate different dendritic and T-cell subsets.

OBJECTIVE: Mechanisms of T-cell stimulation by Flt3 ligand (Flt3L) and granulocyte-macrophage colony-stimulating factor (GM-CSF) remain unclear. Herein, we compared the effects of Flt3L and GM-CSF on the expansion of dendritic cells (DC) and T-cell subsets and cytokine expression. METHODS: Naïve and effector/memory T cells were analyzed by flow cytometry (FC). CD4(+) and CD8(+) T cells and CD11c(+)CD11b(dull/-)(DC1) and CD11c(+)CD11b(+) (DC2) subsets were isolated and the frequency of IFN-gamma-, IL-12- (type 1) and IL-4-, IL-10 (type 2)-producing cells and cytokine mRNA expression evaluated. RESULTS: Flt3L expanded both DC1 and DC2 subsets with a significantly higher percentage and number of DC1 than DC2, while GM-CSF preferentially expanded the DC2 subset. Isolated DC1 from Flt3L-injected mice had significantly higher levels of IL-12 (p40) than IL-10, while the converse occurred with DC2. The numbers of naïve and memory T cells were elevated in mice that received Flt3L or GM-CSF. However, the number of memory CD4(+) and CD8(+) T cells was significantly increased in Flt3L as compared to GM-CSF cohorts. While GM-CSF increased the frequency of both type 1 and type 2 cytokine-producing cells, Flt3L significantly augmented the frequency of type 1 T cells. CONCLUSIONS: In contrast to GM-CSF, Flt3L preferentially induces the expansion of type 1 T cells. The mechanism of Flt3L-induced T-cell stimulation is associated with the expansion of the IL-12 (p40)-producing DC1 and memory T cells.

Animals↗
PubMed1997

Cloning and stable expression of the mGluR1b subtype of human metabotropic receptors and pharmacological comparison with the mGluR5a subtype.

We isolated and characterized a cDNA encoding the human metabotropic glutamate receptor subtype 1b (hmGluR1b). In situ hybridization studies in human brain regions revealed a higher distribution of mGluR1 mRNA in the dentate gyrus of the hippocampus, the substantia nigra pars compacta and the Purkinje cell layer of the cerebellum compared to other regions studied. We established stable expression of recombinant hmGluR1b in L(tk-) mouse fibroblast and Chinese hamster ovary (CHO-dhfr-) cells. In both expression systems, agonist activation of hmGluR1b stimulated inositol phosphate (InsP) formation and elevation of the cytosolic free calcium ([Ca2+]i), and both responses were blocked by (S)-MCPG. The rank order of potency for agonists was quisqualate > glutamate > (1S,3R)-ACPD in both expression systems. Comparison of the agonist profiles of hmGluR1b and hmGluR5a, both stably expressed in L(tk-) cells, indicated the same rank order of potency (quisqualate > glutamate > or = (RS)-3,5-DHPG > or = (1S,3R)-ACPD), but each of the four agonists were more potent on hmGluR5a than on hmGluR1b. In antagonist studies, (S)-MCPG inhibited the agonist-induced InsP formation and elevation of [Ca2+]i in both hmGluR1b- and hmGluR5a-expressing cells. (S)-4CPG and (S)-4C3HPG both inhibited agonist responses only in hmGluR1b-expressing cells. However, in hmGluR5a-expressing cells the antagonist activity of (S)-4CPG and (S)-4C3HPG was dependent on the agonist used in the study, since they inhibited responses to glutamate but not to quisqualate. Stable cell lines expressing specific subtypes of human mGluRs represent valuable tools for the study of the mechanism of action of mGluRs at the molecular and cellular level and as screening targets for identification of subtype-selective agonists or antagonists.

Animals↗
PubMed1997

Alloresponses to HLA-DP detected in the primary MLR: correlation with a single amino acid difference.

The one-way mixed lymphocyte reaction (MLR-1) response was measured in both directions in 50 HLA-A, B, DR and DQ identical pairs and the role of DP studied in MLR stimulation. DR, DQ and DP typing was performed at the allele level by the polymerase chain reaction-sequence specific oligotyping (PCR-SSO) technique. The group consisted of 19 potential bone marrow transplant recipients and 34 matched unrelated donors. When more than one matched donor was available for a patient, donor/donor MLR-1 was also studied. DP identity was observed in 3 out of 50 pairs (6%), however due to homozygosity no incompatibility was present in the stimulating cells in 21 out of 100 cases (21%). There was a significant difference in the range of relative responses (RR) between zero DPB1 mismatches and one (p = 0.002) and two (p = 0.02) DPB1 mismatches: 52.4% of cases in the zero DPB1 mismatch group had RR < 1.0% compared with 31.6% and 27.3% in the one and two DPB1 mismatches. Stimulation by DPB1*0201 and 0301 gave the highest RR (12.9 +/- 22.5 and 17.5 +/- 17.0, respectively) while stimulation with DPB1*0401 and 0402 resulted in low levels of T cell response (1.3 +/- 8.2 and 0.6 +/- 11.5, respectively). When the responses were restricted to DPB1*0401 homozygotes to standardise for responder type similar results were obtained (DPB1*0201 v DPB1*0402 p = 0.008). The protein products of the DPB1*0201 and 0402 alleles differ by a single amino acid at position 69 (DPB1*0402--Lysine, DPB1*0201--glutamic acid). A further analysis was performed therefore scoring responders and stimulators as glutamic acid positive (E+) or negative (E-). There was a highly significant increase in the response to E+ stimulators compared with E- stimulators (p = 0.004). There was also a significant difference in the distribution of relative responses between the E+ stimulator group and the subgroups of E- responders/E- stimulators (p = 0.012) and E+ responders/E- stimulators (p = 0.009). However the amino acid difference at position 69 does not explain all responses due to DP in the MLR-1 as evidenced by the strong responses observed in cases where DPB1*0301 (lysine pos.) was the only difference on the stimulator cells. The results indicate that not all DP incompatibilities elicit a measurable T cell MLR response, but where a response does occur residue 69 in the first domain of DP appears to be pivotal. These results may have implications with respect to GVHD in bone marrow transplantation.

Alleles↗
PubMed1997

Rapid immunologic reconstitution following transplantation with mobilized peripheral blood stem cells as compared to bone marrow.

A majority of patients with intermediate or high-grade non-Hodgkin's lymphoma (NHL) who are treated with high-dose chemotherapy (HDT) and hematopoietic stem cell transplantation subsequently relapse. Until recently, transplantation was associated with high morbidity and mortality and the focus was on improving the safety of this procedure. However, the use of growth factors and other supportive measures has successfully reduced treatment mortality to less than 5%. Therefore, new strategies need to be developed to eliminate the growth of any occult tumor cells reinfused with the stem cell products and the tumor cells remaining in the patient. One approach is to improve the immune function of the patients by a more rapid immune reconstitution and augmentation of effector cell function. We report studies comparing immune recovery following HDT and autologous peripheral stem cell transplantation (PSCT) as compared to autologous bone marrow transplantation (ABMT). These studies examined patients with intermediate and high-grade non-Hodgkin's lymphoma (NHL) who were treated with HDT and PSCT (n = 56) or ABMT (n = 60). The PSCT patients had a significantly faster recovery of circulating monocytes (CD14+ cells), natural killer ((NK) CD56+) cells, T helper (CD4+) cells, TCR gamma/delta cells, and naive T lymphocytes (CD45RA+). Following ABMT there was a significantly more rapid increase in the frequency of T suppressor/effector (CD8+) cells, B (CD19+) cells, CD34+ cells, polymorphonuclear leukocytes (PMN) and memory T lymphocytes (CD45RO+). The CD4:CD8 and CD45RA:CD45RO ratios were consistently higher in the PSCT group as compared to ABMT suggesting an improved ratio of T helper to T effector/suppressor cells and naive T cells. The differences in cellular phenotype translated into improved T cell function (PHA mitogenesis) and T cell help (pokeweed mitogenesis). In addition, there as an accelerated reconstitution of NK cell activity following PSCT as compared to ABMT. The more rapid reconstitution of NK and T cells in patients rescued with PSCT as compared to ABMT may contribute to an improved clinical outcome. Further, patients receiving a PSCT may be more responsive to adjuvant immunotherapy following transplantation.

Adult↗
PubMed1996

Immunosusceptibility genes in rheumatoid arthritis.

The polygenic predisposition to RA is conferred particularly by disease susceptibility sequences in the HVR3 of HLA DRB1 present in those subtypes of DR4 and DR1 that are associated with RA. The aim of this study was to examine predisposing interactions between genes encoding HLA and immunoglobulin molecules. Accordingly, we compared the genetic background of 114 Australian patients with RA with that of Australian controls of similar ethnic background. We identified HLA-A, B, and DR phenotypes serologically, HLA-DR, DQ alleles, and subtypes of DR4 by DNA typing, and Gm allogenotypes and immunoglobulin switch region polymorphisms by RFLP. For the subjects with RA, we confirmed previously reported observations that included an excess of females, 71%, a high frequency of HLA types DR4 or DR1 of 77% versus controls 47%, and a high frequency of the HVR3 susceptibility sequences of 76%, with 24% homozygous, and 52% heterozygous for the sequences. We observed other genetic correlations in RA that included increases in frequencies of DR4 in males, DR1 in females, the class I specificity HLA-B27 overall but more particularly in females, 24% in females, versus 5% of controls, HLA-DQB1*0302 (DQ8) in DR4*0401-positive patients, and the Gm allogenotype 1,2,3;23 +/- ; 5,10, 15% of patients versus 4% of controls. Examination of switch region genes gave no evidence of differences in the polymorphisms distributions. Thus, the major genetic risks for RA that are conferred by female gender and the HVR3 of HLA DRB1 are modulated by interactions between gender and HLA class I and class II alleles, and the Gm allogenotype.

Adult↗
PubMed1996

Vogt-Koyanagi-Harada syndrome in patients of Vietnamese ancestry.

BACKGROUND: Vogt-Koyanagi-Harada syndrome (VKH), is an idiopathic, multisystem inflammatory disorder primarily involving the eye. HLA typing has shown a strong association between the HLA-DR4 antigen and people of Japanese, Han Chinese and Hispanic ancestry with VKH. This study reviewed the clinical features and HLA typing of Vietnamese patients with VKH. PATIENTS AND METHODS: A retrospective review of four unrelated Vietnamese patients with VKH seen in private practice and hospital clinic. The American Uveitis Society (1978) criteria for VKH diagnosis were satisfied. Standard microcytotoxic assays for Class I antigens and HLA-DNA typing of Class II DR antigens (DRB1 genotyping) by the PCR-SSO method were performed. RESULTS: The clinical features of VKH in Vietnamese were comparable to those seen in other Asian races. HLA-DR4 was present in three of the four VKH patients. Two of these patients also expressed the allele DRB1*0405. DISCUSSION: The strong association between HLA-DR4 and the DRB1*0405 allele and VKH seen in Japanese people, may well also exist in Vietnamese people. The HLA association suggests an immunogenetic predisposition to VKH.

Adult↗
PubMed1994

[Follow-up of severely injured patients with scoring systems on the intensive care unit].

A variety of different scoring systems are in current use, with an increasing impact on intensive care treatment. Originally these scoring systems were applied to evaluate objective grading and to estimate survival and mortality. More recently, other potential applications have been investigated. While clinical monitoring and assessment of therapeutic success are the primary goals, scoring systems can be used to define comparable patient collectives and to delineate predefined patient groups for clinical trials. Scoring systems are gaining increasing importance in evaluation of the level of therapeutic intervention and care provided as well as in quality assessment. On the whole, however, accuracy, the probability that outcome will be correctly predicted for an individual patient, is still inadequate. Although desirable, individual patient prediction is therefore not allowed, and therapeutic strategies and therapy evaluation based on scoring systems cannot be implemented, or only in a limited way. For daily use in individual patient evaluation--monitoring, therapy response, prognosis--biochemical monitoring is still of primary importance. Scoring systems have now found a useful application as a supplement, rather than a rival, to clinical patient evaluation.

Critical Care↗
PubMed1993

Instant therapy of acquired agranulocytosis and sepsis by recombinant granulocyte-macrophage colony-stimulating factor in a polytrauma patient.

Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) was given to an intensive-care patient with polytrauma in a life-threatening situation with acquired agranulocytosis and sepsis. Mature granulocytes reappeared in the blood 2 days after initiation of rhGM-CSF therapy; granulocyte precursors peaked at 43% after 5 days. Bone marrow examination performed 7 days after the beginning of rhGM-CSF therapy revealed complete regeneration of granulopoiesis. The functional analysis of these blood leukocytes in vitro showed regular production of reactive oxygen radicals. Clinically, the patient recovered without any serious side effects due to the rhGM-CSF therapy. These results suggest that rhGM-CSF accelerates granulocyte recovery from acquired agranulocytosis with the presence of their functional activity.

Adult↗
PubMed1993

Oxytocin-stimulated phosphoinositide hydrolysis in human myometrial cells: involvement of pertussis toxin-sensitive and -insensitive G-proteins.

Phosphoinositide hydrolysis is important in mediating the actions of oxytocin and prostaglandin (PG) F2 alpha on uterine contractions during labour. We have measured the effect of oxytocin, PGF2 alpha and other agents on the formation of inositol phosphates (IPs) in cultured human myometrial cells labelled with [3H]inositol and on changes in intracellular free Ca2+ concentration ([Ca2+]i) in cells loaded with Fura-2. Oxytocin induced the formation of [3H]IPs in a concentration-dependent manner with an EC50 (concentration of agonist producing 50% of the maximal response) of 1.4 +/- 0.5 nmol/l (mean +/- S.E.M.). The maximal response was obtained with 1 mumol oxytocin/l and represented a stimulation of 670% over basal. PGF2 alpha also stimulated the formation of [3H]IPs and the response at 1 mumol/l was a 204% stimulation over basal. The effects of PGF2 alpha were independent of extracellular Ca2+ but the effect of oxytocin was reduced with low extracellular Ca2+. Cyclic AMP formation, induced by forskolin or PGE2, had no effect on the stimulated levels of [3H]IPs. Pertussis toxin (PT) reduced the oxytocin-stimulated formation of [3H]IPs in a concentration-dependent manner. The maximal effect of PT resulted in an 80% reduction in the formation of [3H]IPs. However, PGF2 alpha stimulation was not affected by PT treatment. To analyse the action of PT further, we studied its effect on oxytocin-induced changes in [Ca2+]i. The basal [Ca2+]i was 112 +/- 4 nmol/l (n = 225 cells) and was not affected by PT treatment (109 +/- 3 nmol/l; n = 200 cells). In the absence of PT, 1 mumol oxytocin/l increased [Ca2+]i to a peak of 522 +/- 26 nmol/l, and in PT-treated cells, the [Ca2+]i peak was reduced to 348 +/- 16 nmol/l. Similar inhibitory effects of PT were obtained at oxytocin concentrations ranging from 1 to 100 nmol/l. Our data suggest that in human myometrial cells, the oxytocin-induced production of [3H]IPs and increase in [Ca2+]i are mediated by a PT-sensitive G-protein. However, a significant fraction of the oxytocin response appears to be mediated by a PT-insensitive G-protein, possibly a member of the Gq family.

Calcium↗
PubMed1990

Inositol 1,4,5-trisphosphate and oxytocin binding in human myometrium.

The presence of inositol 1,4,5-trisphosphate (IP3) receptors in human myometrium has been investigated and their concentration compared with that of oxytocin receptors. Myometrial microsomes were incubated with 3H-IP3 alone and in the presence of unlabeled IP3. Binding was to a single class of noninteracting sites with a density of 1-2 pmol/mg of protein. The sites had characteristics of true IP3 receptors, i.e., very fast association and dissociation rates, high affinity (Kd 25-50 nM) and specificity (IP3 greater than IP3[2,4,5], IP4 much greater than IP5 greater than IP3[1,3,4], IP1, IP2, IP6), and did not metabolize 3H-IP3. The binding was maximal at pH 8, and was inhibited by calcium (IC50 = 80 nM), magnesium (IC50 = 100 microM), heparin (IC50 = 4.5 micrograms/ml), and GTP (IC50 = 150 microM). The concentration and affinity of IP3 receptors were similar in pregnant and nonpregnant myometrium and remained constant during labor. By contrast, the density of oxytocin receptor increased significantly from nonpregnant to pregnant tissue and fell in advanced spontaneous labor but not in advanced induced labor. These results provide new, additional evidence for the involvement of the phosphatidylinositol pathway in the control of uterine contractility.

Binding, Competitive↗
PubMed1990

[Additional intra-abdominal injuries in multiple-traumatized patients with pelvic fractures. Difficulties in diagnosis and therapy].

Between 1.1. 1987 to 31.12. 1988 178 polytraumatized patients were treated with 62 patients demonstrating pelvic fractures. In 58% of patients injured by rapid falls pelvic fractures were diagnosed compared to only 25% of all patients with traffic accidents. 22% of all polytraumatized patients suffered from intraabdominal injuries, with raise to 47% in patients with pelvic fractures. To avoid unnecessary laparotomies caused by questionable positive lavage ultrasonography is recommended because of its high accuracy and lack of any diagnostic morbidity. 27 of 29 patients with intraabdominal injuries underwent laparotomy. One patient with an isolated kidney rupture was treated conservatively and one patient died before operation. The most common intraabdominal lesion was rupture of liver in 52% and splenic injury in 10 patients. Lesions of the intestine were diagnosed in 11 patients mostly in combination with parenchymal injuries. Concerning the therapeutical approach a conservative treatment is recommended in order to shorten time of operation in concern of the progressively increasing retroperitoneal hematoma. The overall mortality rate was 36%. Most common cause was direct injury of CNS in 14 patients of whom 6 patients suffocated during the first 24 hours. Unstable dislocated pelvic fractures were primary stabilized by external fixator which may help to avoid further progressive retroperitoneal hematoma.

Abdominal Injuries↗
PubMed1990

[Primary therapy of polytraumatized patients and reasons for early transfer to a specialty hospital].

200 polytraumatized patients were treated at our institution between 1.1.1987 to 28.2.1989. 58 patients had been submitted from other hospitals. Reasons for submissions were complex cranio-facial-trauma in 27 patients, thoracic trauma in 9 patients and complex abdominal injury in 8. In 13 of 44 patients (29.5%), submitted in between the first 24 h after trauma, severe and partially life threatening injuries had not been diagnosed at the first hospital. Failures in decision making burden especially patients with cranio-facial injuries, in whom intraabdominal and thoracical injuries are often overseen. Patients with abdominal trauma were often submitted after an operative attempt demonstrating complex traumatisation which was underestimated at primary diagnosis. Polytraumatized patients need to have a multidisciplinary management performed by a specified crew with all diagnostic facilities available to avoid overestimation or neglection of additive injuries. Direct submission into a specified medical center is therefore recommended and seems preferable to submission after failed or insufficient primary therapy in inadequately equipped smaller hospitals.

Adult↗
PubMed1990

[Prognosis and therapy of liver injury in patients with multiple injuries].

Between 1.7. 1986 and 31.10. 1989 abdominal trauma was seen in 108 (35.8%) of 300 polytraumatized patients, 44 of these showed rupture of the liver. 23 patients belonged to grade I-III (Moore-classification) and 11 patients to grade IV. Extensive bilobar parenchymal destruction (grade V) was found in 10 patients including 6 patients with retrohepatic vena cava injury. 80% of all patients with liver trauma had intraabdominally associated injuries. In Grade I-II (n = 4) patients were treated conservatively and continuously observed by ultrasound. Injuries graded to III (n = 19) and IV (n = 11) were mostly treated by simple suture or segmental resection. In grade V hemihepatectomy was done in 4 cases, in 2 cases combined by packing and in 1 patient packing only. In 3 patients no adequate therapy was possible. The mortality rate being 36% (n = 16), hemorrhagic complications were the most common cause of death (7 of 16 patients). This was due only to the patients graded to V. In comparison the prognostic factor in grade I-IV ruptures were the associated injuries. In all these cases hemorrhage was stopped by a conservative, organ-retaining therapy. No further hemorrhage occurred. Liver packing was mainly used as additional treatment in cases of coagulopathy after resection. Further indications are extensive bilobar parenchymal destruction without the possibility of primary reconstruction and temporary hemostasis to allow transport to a specialized hospital.

Abdominal Injuries↗
PubMed1987

[2 nonspecific cecal ulcers in a 6-year-old child as a cause of intestinal hemorrhage].

This is a report on recurrent rectal bleedings in a 6-year-old boy caused by 2 non-specific ulcers of the caecum. These ulcers are extremely rare in childhood and their aetiology is unknown. In this case the causative factor was supposed to be a preliminary cortisone therapy. The diagnosis of these ulcers is quite difficult because of the absence of any specific symptoms. X-ray and endoscopy of the colon often fail to give reliable results. Usually the diagnosis can be obtained only by laparotomy and histology. In therapy hemicolectomy is suggested to prevent perforation as the most usual complication. During conservative treatment coloscopic findings have to be controlled constantly.

Cecal Diseases↗