Biomedical subjects
Publications and source records attributed to P E Morris.
Means have been developed for the synthesis and addition of 9-deaza-9-lithiopurine derivatives to the carbohydrate-derived cyclic imine 6 in facile convergent syntheses of biologically active aza-C-nucleosides.
Patients with purine nucleoside phosphorylase (PNP) deficiency present a selective T-cell immunodeficiency. Inhibitors of PNP are, therefore, of interest as potential T-cell selective immunosuppressive agents. BCX-1777 is a potent inhibitor of PNP from various species including human, mouse, rat, monkey and dog, with IC50 values ranging from 0.48 to 1.57 nM. BCX-1777, in the presence of 2'-deoxyguanosine (dGuo, 3-10 microM), inhibits human lymphocyte proliferation activated by various agents such as interleukin-2 (IL-2), mixed lymphocyte reaction (MLR) and phytohemagglutinin (PHA) (IC50 values < 0.1-0.38 microM). BCX-1777 is a 10-100-fold more potent inhibitor of human lymphocyte proliferation than other known PNP inhibitors like PD141955 and BCX-34. Nucleotide analysis of human lymphocytes indicate that inhibition of proliferation by BCX-1777 correlates with dGTP levels in the cells. BCX-1777 has excellent oral bioavailability (63%) in mice. At a single dose of 10 mg/kg in mice, BCX-1777 elevates dGuo to approximately 5 microM. BCX-1777 was not effective in mouse T-cell models such as delayed type hypersensitivity (DTH) and splenomegaly because mouse T-cells do not accumulate dGTP as do human T-cells. However, in the human peripheral blood lymphocyte severe combined immunodeficiency (hu-PBL-SCID) mouse model, BCX-1777 was effective in prolonging the life span 2-fold or more. This is the first known example of a PNP inhibitor that elevates dGuo in mice similar to the levels observed in PNP-deficient patients. Furthermore, these dGuo levels are also required for in vitro T-cell inhibition by BCX-1777. Thus, BCX-1777 represents a novel class of selective immunosuppressive agents that could have therapeutic utility in various T-cell disorders.
Vokey and Read (1992) proposed that the effect of typicality on face recognition was a function of familiarity and rated memorability, reporting that typicality loaded equally on components that they identified with these variables. We offer an alternative interpretation to that of Vokey and Read in terms of the relationship between typicality and attractiveness (when the former is measured as a deviation from the typical face), the mere exposure effect, and the metamemorial beliefs of participants. In our study we identified distinctiveness, attractiveness, and residual memory components. Supporting our interpretation, three of our four measures of typicality failed to load with familiarity on the attractiveness component. Only our measure of deviation from the typical face replicated Vokey and Read's results because of its correlation with attractiveness.
OBJECTIVES: To assess the safety and effect on coagulopathy of a range of doses of recombinant human activated protein C (rhAPC). To determine an effective dose and duration of rhAPC for use in future clinical trials. DESIGN: Double-blind, randomized, placebo-controlled, multicenter, dose-ranging (sequential), phase II clinical trial. SETTING: Forty community or academic medical institutions in United States and Canada. PATIENTS: One hundred thirty-one adult patients with severe sepsis. INTERVENTIONS: Intravenous infusion of rhAPC (12, 18, 24, or 30 microg/kg/hr) or placebo for 48 or 96 hrs. MEASUREMENTS AND MAIN RESULTS: No significant differences in incidence of serious bleeding events (4% rhAPC, 5% placebo, p >.999) or incidence of serious adverse events (39% rhAPC, 46% placebo, p = 0.422) between rhAPC- and placebo-treated patients were observed. One of 53 rhAPC-treated patients with suitable immunogenicity samples had a low level, transient, non-neutralizing anti-APC antibody response not associated with any clinical adverse event. Significant dose-dependent decreases in both D-dimer (p <0.001) and end of infusion interleukin 6 levels (p =.021) were demonstrated. No statistically significant effects on fibrinogen or platelet counts were observed. A nonstatistically significant 15% relative risk reduction in 28-day all-cause mortality was observed between rhAPC- and placebo-treated patients. CONCLUSIONS: rhAPC was safe and well-tolerated and demonstrated a dose-dependent reduction in D-dimer and interleukin 6 levels relative to placebo. The dose of 24 microg/kg/hr for 96 hrs was selected for use in future clinical studies.
The acute respiratory distress syndrome (ARDS) is a clinical syndrome with primarily supportive management options. Despite extensive basic and clinical investigations, multiple pharmacological and nonpharmacological modalities have been unsuccessful in decreasing mortality. Nonetheless, these efforts have substantially heightened our understanding of ARDS pathophysiology. Investigators continue to create new and more complex therapeutic strategies that may have significant clinical impact. Several pharmacological agents for ARDS are in development and have shown either great promise or are at most, under phase II evaluation. The order in which therapeutic options are presented in this review highlights therapeutic options other than the anti-inflammatory approach. In addition to the anti-inflammatory category, vasodilators, surfactant therapy, immunonutrition and partial liquid ventilation are all being evaluated. Within the anti-inflammatory category. new mechanistic approaches include the 'anti-inflammatory nature' of interleukin-10, the inhibitory aspects of lysophosphatidic acid on endothelial cell permeability, and the use of recombinant human anti-coagulant proteins (activated protein C and tissue factor pathway inhibitor) to reduce the inflammatory cycle that contributes to microvascular thrombi. Previous work with surfactant in ARDS had its limitations, however, these trials were of sufficient success to spawn 2 new synthetic compounds. These new synthetic surfactants incorporate mixtures of phosphatidylcholine and phosphatidylglycerol (the key phospholipids within endogenous surfactant) and either recombinant surfactant protein C or an analogue of surfactant protein B. Recently, the ARDS Network's low tidal volume study has broken the cycle of decades of negative ARDS trials and demonstrated an improvement in mortality. Through better mechanistic approach and study design, investigator compliance with exclusion criteria, and better understanding of the complexities of patient management, the next pharmacological ARDS trials will hopefully be successful and lead to further reductions in patient mortality.
In medium-sized groups such as classes, it is often desirable that the members become acquainted with one another. Toward this end, various methods of introducing group members are often used, with only anecdotal evidence for their effectiveness. The name game is a method for introducing group members that is based on the principles of retrieval practice. The authors compared 2 versions of the name game with a widely used introductory method--pairwise introductions--and found that the name game participants were much better at remembering one another's name after 30 min, 2 weeks, and 11 months. A second experiment tested the contribution of retrieval practice by comparing 2 versions of the name game with a procedure that was matched for number of repetitions and time spent on the task. Again, the name games were superior.
Although in vitro data has linked reactive oxygen species (ROS) to activation of nuclear factor kappaB (NF-kappaB), little data exist regarding this relationship in human disease. We hypothesized that bone marrow transplantation (BMT) would impart a degree of oxidative stress that might lead to in vivo activation of the redox-sensitive transcription factor NF-kappaB. Because NF-kappaB regulates transcription of many proinflammatory mediators, we reasoned that activation of NF-kappaB might contribute to the development of transplant-related complications. To evaluate NF-kappaB activation in humans, we measured NF-kappaB binding activity in nuclear extracts of bronchoalveolar lavage (BAL) cells obtained before and after allogeneic bone marrow transplantation (BMT) in 7 patients. Changes in BAL cell NF-kappaB binding activity were compared with changes in urinary F2-isoprostane concentration, an indicator of in vivo free radical-catalyzed lipid peroxidation. Although the extent of in vivo lipid peroxidation has substantial interindividual variability over time, we found a strong correlation between the pre/post-BMT ratio of urinary isoprostane concentrations and pre/post-BMT ratio of NF-kappaB binding activity in BAL cells, R = 0.96, p = 0.0005). This correlation is selective, because no relationship was found between the transcription factor CREB and urinary F2-isoprostane excretion. Although limited by the small number of patients studied, our data link oxidant stress to NF-kappaB activation in human alveolar macrophages following BMT. It is possible that such interactions may contribute to the clinical course after BMT by affecting transcription of proinflammatory genes.
It is conventionally assumed that many faces are relatively typical and few are distinctive (e.g. Valentine, 1991), producing a highly skewed distribution. However, Burton and Vokey (1998) argue that the distribution will be normal, and our review of previous research suggested this is true. In three studies we explored the distributions using different techniques to estimate distinctiveness. Both traditional ratings and pairwise selection produced normal distributions. However, ratings emphasizing the degree of deviation from a typical face were skewed towards the distinctive end of the scale. The instructions given when distinctiveness is rated may not necessarily oppose typicality with distinctiveness: a face that is relatively typical might also stand out in a crowd because of some particular feature, familiarity or a host of other reasons. In our fourth study, recognition memory was predicted by all of the distinctiveness measures, with the relationship being stronger after a 5-week delay than in the immediate test.
Kay (1955) presented a text passage to participants on a weekly basis and found that most errors and omissions in recall persisted despite repeated re-presentation of the text. Experiment I replicated and extended Kay's original research, demonstrating that after a first recall attempt there was very little evidence of further learning, whether measured in terms of further acquisition or error correction, over three more presentations of the text passages. Varying the schedule of presentations and tests had little effect, although performance was better when intermediate trials included both presentation and test than when only presentations or tests occurred. Experiment 2 explored whether this 'failure of further learning' effect could be overcome by (a) warning participants against basing their recall on their previous recall efforts and specifically directing them to base their recall upon the passages, (b) making each presentation more distinctive, or (c) drawing participants' attention to areas that would benefit from further learning by requiring them to tally their omissions and errors. The effect persisted in all cases. The findings have serious implications for the learning of text material.
Purine nucleoside phosphorylase (PNP) is one of the enzymes comprising the purine salvage pathway , and is responsible for the catalysis of the reversible phosphorolytic cleavage of purine ribonucleosides and 2'-deoxyribonucleosides. The pivotal role of PNP in T-cell proliferation has been demonstrated in patients with inherited PNP deficiency, where T-cell levels may be 1-3% of normal. This observation helped establish the critical role of PNP in T-cells and provided a rationale for developing inhibitors of PNP. Inhibitors of PNP may be useful for treating a variety of T-cell related autoimmune diseases including psoriasis, rheumatoid arthritis and Crohn s disease and T-cell cancers. In this manuscript, the x-ray crystal structure of the PNP enzyme is described. Results of a structure-based drug design program aimed at designing small-molecule inhibitors of PNP are also described. Of the many classes of compounds synthesized, studied and reviewed, only one, the 3-pyridinylmethyl-9-deazaguanine (BCX-34, 39) analog has been used in clinical trials. Both topical and oral formulations of BCX-34 were studied in psoriatic patients and the results of these clinical trials are described.
The present study was performed to determine whether genistein could inhibit in vivo LPS-induced alveolar macrophage TNFalpha production and thus reduce the alveolar neutrophil influx following LPS. In vitro incubation with genistein completely inhibited LPS-induced TNFalpha production by alveolar macrophages (AM) from BALB/c mice. Subsequently mice were pretreated with intraperitoneal genistein or vehicle, then received nasal LPS to induce an alveolitis. Genistein was then administered every eight hours for five days following LPS. At 24 hours after LPS, the bronchoalveolar lavage (BAL) TNFalpha and ex vivo TNFalpha production from AM, were lower in the genistein treated animals. As well, total BAL white blood cell (WBC) count was reduced in the genistein as compared to the vehicle-only group. The percent neutrophils and the resolution of neutrophils were similar between genistein and vehicle groups. Therefore, genistein was able to decrease AM TNFalpha production, and was associated with a decrease in BAL WBC count post-LPS.
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We examined the effects of estrogen on tumor necrosis factor alpha (TNF-alpha)-induced expression of intracellular adhesion molecule (ICAM-1) and vascular adhesion molecule (VCAM-1) in cultured human bronchial smooth muscle cells (BSMC). Experiments were performed in triplicate in T-75 tissue culture flasks containing normal human BSMC. Four experiments were carried out: untreated BSMC cells (control); TNF-alpha 1000 U/ml stimulation of BSMC; forskolin 5 microM before TNF-alpha stimulation of BSMC; and estradiol 30 microM before TNF-alpha stimulation of BSMC. Cyclic adenosine monophosphate was measured by a commercially available radioimmunoassay kit. Cell expression of ICAM-1 and VCAM-1 was quantified by flow cytometry Incubation of cells with TNF-alpha 1000 U/ml for 24 hours elicited a 27-fold increase in basal expression of ICAM-1 and a 2-fold increase in VCAM-1 (p>0.05). Incubation of BSMC with forskolin 5 microM, for 1 hour before TNF-alpha, decreased TNF-alpha-induced expression of ICAM-1 by 62% and VCAM-1 slightly by 17%. The BSMC incubated with estradiol 30 microM, 1 hour before TNF-alpha, decreased TNF-alpha-induced expression of ICAM-1 by 21%; VCAM-1 remained unchanged (p>0.05). We found a trend toward inhibition of TNF-alpha-stimulated ICAM-1 expression in cultured BSMC with pretreatment with estradiol. However, due to large variability within the cell culture model, statistical significance was not reached.
The incidence of fractures and of osteoporosis differs between Oriental and Western Caucasian women. This may depend, at least in part, on nutritional factors, including dissimilarities in dietary intake of phytoestrogens. To investigate this possibility, 2-month-old female rats were ovariectomized (OVX) or sham-operated (SHAM), fed a casein-based diet, injected daily with subcutaneous genistein (GEN), the most abundant and best characterized phytoestrogen, or vehicle (Veh) and killed 21 days after surgery. As expected, ovariectomy resulted in loss of bone mineral density (BMD) and in uterine atrophy. However, administration of 5 micrograms GEN per gram body weight (b.w.) ameliorated the ovariectomy-induced loss of BMD (189 +/- 2 mg/cm2 in OVX and 192 +/- 2 in OVX with 5 micrograms GEN/g b.w. per day; p < 0.05). One microgram GEN per gram body weight did not affect the BMD loss and the effect of the 5 micrograms and 25 micrograms GEN per gram body weight were statistically not different. A trend toward reduced uterine atrophy (21% reduction) was noted with the 25 micrograms GEN dose, but not with the 1 microgram and 5 micrograms doses. A separate experiment with 2 x 2 factorial design was conducted to elucidate the mechanism by which GEN ameliorates ovariectomy-induced bone loss. In this experiment, histomorphometry demonstrated a dramatic reduction in trabecular bone volume after ovariectomy (7.6 +/- 0.7% of total bone volume in SHAM-Veh vs 3.3 +/- 0.2% in OVX-Veh; p < 0.01) and less bone loss in OVX rats injected with 5 micrograms GEN per gram per day (3.3 +/- 0.2% of total bone volume in OVX-Veh vs 5.2 +/- 0.4% in OVX-GEN; p < 0.01). Administration of GEN was associated with higher bone formation rate per tissue volume and with a trend toward a higher number of osteoblasts per bone perimeter. The parameters of bone resorption were not affected by GEN. The concentration of serum osteocalcin and the urinary excretion of deoxypyridinoline provided corroborating results. Since production of proinflammatory cytokines is intimately involved in the pathogenesis of postmenopausal osteoporosis, the effect of GEN on lipopolysaccharide-induced in vitro production of Tumor necrosis factor-alpha (TNF alpha) was tested in monocytic cells from the same four rat groups. Production of TNF alpha was markedly elevated in OVX-Veh as compared with the SHAM-Veh rats, but this was blocked by GEN in the OVX rats. This study shows that GEN reduces both trabecular and compact bone loss after ovariectomy and that this protective effect differs from that of estrogen, since it depends on stimulation of bone formation rather than on suppression of bone resorption. Lack of action of GEN on uterine atrophy supports the possibility that this GEN dose affects target tissues via non-estrogenic mechanisms. Modulation of cytokine production may be involved in the effect of GEN on bone.
Pulmonary complications are a major clinical problem following allogeneic bone marrow transplantation (BMT), contributing to more than 30% of transplant-related mortalities. Idiopathic pneumonia syndrome is responsible for significant mortality among BMT patients. However, the etiology of injury to the lung parenchyma by this disease syndrome is unknown and it has been difficult to evaluate the cellular and molecular mechanisms underlying IPS in the absence of a suitable animal model. To study post-BMT lung disease during graft-versus-host disease (GVHD), we have developed a murine model that utilizes a semi-allogeneic parental --> F1 transplant strategy to induce a mild form of GVHD. Progressive inflammatory lung disease developed in animals with mild GVHD, as indicated by changes in immune cell distribution and cytokine expression in the lungs of transplanted animals. Histologic analysis of lung tissue from GVHD mice at 3 wk post-BMT showed minor immunopathologic changes compared with control mice. In contrast, lungs of GVHD mice at 12 wk displayed histopathologic hallmarks of interstitial pneumonitis, such as prominent perilumenal mononuclear cell infiltration and areas of alveolar congestion. Flow cytometric analysis of lung interstitial cells of GVHD mice revealed an increase in CD8+ T-cells at week 3, which decreased to normal levels by week 12 post-BMT. Simultaneously, the percentage of CD4+ T-cells increased progressively above normal levels and peaked at week 7 post-BMT. Analysis of cytokine mRNA expression in lung tissue indicated that steady state levels of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, interferon-gamma, and IL-12 were significantly elevated in lungs of GVHD mice at 3 wk post-BMT compared with untreated controls. Mice that were transplanted with allogeneic bone marrow alone (BMT controls) also displayed elevated expression of these cytokines, although only IL-6 was significantly higher than in untreated controls. In contrast, at 12 wk after transplantation only TNF-alpha and IL-12 levels remained elevated in GVHD mice, suggesting prolonged macrophage activation. On the basis of these findings, we conclude that allogeneic bone marrow transplantation in this mouse model causes a progressive interstitial pneumonitis, which is characterized by an acute influx of CD8+ T-cells, followed in the chronic phase by a prominent accumulation of CD4+ T-cells, and is associated with persistent production of cytokines known to activate macrophages.
Underwater close visual inspection (CVI) and magnetic particle inspection (MPI) are major components of the commercial diver's job of nondestructive testing and the maintenance of subsea structures. We explored the accuracy of CVI in Experiment 1 and that of MPI in Experiment 2 and observed high error rates (47% and 24%, respectively). Performance was strongly correlated with embedded figures and visual search tests and was unrelated to length of professional diving experience, formal inspection qualification, or age. Cognitive tests of memory for designs, spatial relations, dotted outlines, and block design failed to correlate with performance. Actual or potential applications of this research include more reliable inspection reporting, increased effectiveness from current inspection techniques, and directions for the refinement of subsea inspection equipment.
An acute neutrophilic lung injury was compared in Balb/c normal and nu/nu (nude) mice to assess the role of T lymphocytes in the resolution of acute pulmonary neutrophilic inflammation following the administration of endotoxin. Maximal neutrophilic infiltration occurred on day 1 post-endotoxin treatment and declined to near normal levels by day 5. In contrast, the percentage of lymphocytes in the bronchoalveolar lavage (BAL) fluid increased from 1.8% on day 1 post-endotoxin to greater than 11% on days three and five, during which time neutrophil resolution was occurring. On days 1-5 after endotoxin administration, approximately 40% of the CD4 lymphocytes expressed the cell surface activation marker, CD69. Despite being CD69+, CD4 cells did not express the high affinity IL-2 receptor chain, CD25, to any significant extent on any of the days studied. To assess the contribution of T cells to the rate of clearance of neutrophils from the BAL, normal and nude Balb/c mice were compared for the percentage of neutrophils following nasal administration of endotoxin. Endotoxin-treated nude mice did not demonstrate significant differences in either the total white blood cell counts or in the clearance of neutrophils from the BAL, as compared to normal Balb/c mice. These data indicate that the influx of activated T cells during the resolution of neutrophilic pneumonitis does not contribute to the rate of neutrophil clearance during acute lung injury.
OBJECTIVE: To determine the levels of glutathione and cysteine in patients with ARDS and examine the effect of treatment with N-acetylcysteine (NAC) and L-2-oxothiazolidine-4-carboxylate (Procysteine; Clintec Technologies Inc; Chicago [OTZ]) on these levels and on common physiologic abnormalities, and organ dysfunction associated with ARDS. DESIGN: Randomized, double-blind, placebo-controlled, prospective clinical trial. SETTING: ICUs in five clinical centers in the United States and Canada. PATIENTS: Patients meeting a predetermined definition of ARDS and requiring mechanical ventilation. INTERVENTION: Standard care for ARDS and I.V. infusion, every 8 h for 10 days, of one of the following: NAC (70 mg/kg, n=14), OTZ (63 mg/kg, n=17), or placebo (n=15). MAIN RESULTS: Both antioxidants effectively repleted RBC glutathione gradually over the 10-day treatment period (47% and 49% increases from baseline values for NAC and OTZ, respectively). There was no difference in mortality among groups (placebo, 40%; NAC, 36%; OTZ, 35%). However, the number of days of acute lung injury was decreased and there was also a significant increase in cardiac index in both treatment groups (NAC/OTZ [+]14%; placebo [-]6%). CONCLUSIONS: Our findings suggest that repletion of glutathione may safely be accomplished with NAC or OTZ in patients with acute lung injury/ARDS. Such treatment may shorten the duration of acute lung injury, but larger studies are needed to confirm this.