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Biomedical subjects

J Wilson

Publications and source records attributed to J Wilson.

At least 253 records · Page 14Linked to original sources

Phase IB trial of picibanil (OK-432) as an immunomodulator in patients with resected high-risk melanoma.

The microbial immunostimulant OK-432 has been studied intensively in preclinical systems and has shown promise as an anticancer agent in trials that have been conducted over the past 20 years in Japan. To date, no systematic dose response evaluation of this agent has defined its dose-limiting toxicity or immunobiological activity. A phase IA study has been conducted in 25 patients with metastatic cancer at the University of Pittsburgh Cancer Institute Melanoma Center, establishing 30 KE as the maximal tolerable dosage, on the basis of cutaneous reactions. Subsequently, 48 patients with resected high-risk melanoma participated in a phase IB study of OK-432. This study has evaluated the immunomodulatory activity of OK-432 at five dosages ranging from 1 KE to 20 KE, administered ID twice weekly for 3 months. A formal analysis of the treated population in comparison to the randomized control group has been conducted, and profound immunological effects have been defined in the group of patients treated with OK-432. Patients who participated in this trial had a significant depression of OK-432-inducible cytokine production (interleukin-1 beta, interferon gamma, and tumor necrosis factor alpha) at baseline. Treatment with OK-432 reversed this deficit for interferon gamma (IFN gamma) production in a dose-dependent manner, and mitigated the inhibition for interleukin-1 (IL-1) across all dosage groups. The impact of OK-432 upon other immunological functions of the treated cohorts is more variable, with durable suppression of mononuclear cell superoxide production, and in vitro cytotoxicity to tumor. Immunological characteristics of the entire cohort demonstrate a strong and significant correlation of elevated blood CD16+ cell counts and natural killer activity with early tumor progression and death due to melanoma. Favorable prognosis is associated with monocyte capacity to produce tumor necrosis factor (TNF), and polymorphonuclear leukocyte formylmethionyl-leucylphenylalanine-inducible superoxide release. This study reveals several new immunological correlates of tumor progression and lethal outcome in resected high-risk melanoma. It demonstrates that the depressed IL-1, TNF, and IFN gamma release associated with melanoma may be mitigated by treatment with OK-432. This study has defined treatment and dose response patterns of immunomodulation associated with one of the most complex immunological agents yet evaluated in phase IB trials, in a well-defined population of high-risk patients with resected melanoma.

Adjuvants, Immunologic↗

Thy-1 expression on blast cells from adult patients with acute myeloid leukemia.

Bone marrow and peripheral blood from 28 adult patients with acute myeloid leukemia (AML) were analyzed for the surface expression of the Thy-1 antigen by dual-colour flow cytometry. The Thy-1 antigen was expressed on greater than 5% of cells from seven patients with the proportions of Thy-1 positive cells ranging from 8.1% to 85.0%. The CD34+ Thy-1+ phenotype was present in all seven cases. The expression of Thy-1 on leukemia cells from patients with AML may need to be considered in the development of methods of normal stem cell isolation from these patients.

Acute Disease↗

Busulfan and cyclophosphamide (BU/CY2) as preparative regimen for patients with lymphoma.

The combination of busulfan and cyclophosphamide has seldom been employed as a conditioning regimen for patients with lymphoma. Twenty patients with relapsed or refractory lymphoma were treated with busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) (BU/CY) followed by peripheral blood stem cell rescue in 19 patients or autologous bone marrow in one patient. There were 12 females and eight males, with a median age of 48 years (range 30-65). Four patients had Hodgkin's disease, and 16 patients had non-Hodgkin's lymphoma. Disease status at the time of BU/CY was: first relapse in 10 patients (four patients with chemosensitive disease and six patients with chemoresistant disease), primary refractory disease in six patients, and more advanced disease in four patients. Excessive treatment-related toxicity was not noted. There were no cases of interstitial pneumonitis, but three cases of veno-occlusive disease occurred. At 2 years, the estimated overall survival and event-free survival are 50% and 33%. We concluded that BU/CY seems to have sufficient antilymphoma activity, is devoid of excessive toxicity and warrants further investigation in this patient population.

Adult↗

Integration host factor is a transcriptional cofactor of pilE in Neisseria gonorrhoeae.

Integration host factor (IHF) is a small, heterodimeric DNA-binding protein with pleiotropic function. IHF was purified to apparent homogeneity from Neisseria gonorrhoeae. Gel-retardation assays demonstrated binding of IHF to the pilE promoter region. The IHF-binding site was identified by DNase I protection assays and mapped proximal to three previously defined pilE promoters. Removal of the putative IHF-binding domain from pilE promoter DNA negated retardation of the DNA fragment when assessed by gel-shift analysis. Kleinschmidt electron microscopy showed pronounced kinking of pilE promoter DNA following incubation with IHF. Isogenic N. gonorrhoeae strains were constructed that contained either a wild-type pilE locus or a deleted pilE locus where the IHF-binding domain was removed. Primer-extension analysis and Northern blotting of total gonococcal RNA showed that in the absence of IHF binding at the pilE promoter, transcription was reduced 10-fold. Together, these data indicate that IHF is a transcriptional co-activator of pilE.

Bacterial Proteins↗

Bone marrow transplantation in late infantile Batten disease and juvenile Batten disease.

Two patients, one each with LINCL and JNCL, underwent BMT in an attempt to alter the course of their disease. The LINCL patient received two transplants, one when asymptomatic, which was rapidly rejected, and a second BMT at age 3 years 9 months when the EEG had become abnormal. He has deteriorated in the following 2 years and now has only a few words, limited vision and feeding difficulties. Only two major seizures have occurred, but minor seizures are frequent. Although he is less severely affected than his sister at the same age, it is difficult to know if BMT has had any effect. The most significant difference is the relative mildness of seizure activity. The JNCL patient, transplanted at 8 years, when her visual problems had already started, is still in mainstream school, has good speech and good quality of life at age 9 1/2 years. No regression has been found, but EEG changes are now present and her vision has further deteriorated. The effect of BMT, if any, will not become apparent for several years in the more slowly progressive JNCL.

Adolescent↗

The relationship between 3 km running performance and selected physiological variables.

The aim of this study was to assess the relationship between a number of physiological variables and running velocity at 3 km (v-3km) in a group of male runners. Sixteen well-trained middle- and long-distance runners (mean +/-s: age 22.4 +/- 4.2 years, body mass 63.5 +/- 6.2 kg, VO2 max 73.3 +/- 6.7 ml kg-1 min-1) underwent laboratory treadmill tests to determine their maximum oxygen uptake (VO2 max), running economy at three submaximal velocities (12.9, 14.5 and 16.1 km h-1 or 14.5, 16.1 and 17 km h-1), predicted velocity at VO2 max (v-VO2max), velocity (v-Tlac) and VO2 (VO2-Tlac) at the lactate threshold and their velocity (v-4mM) and VO2 (VO2-4mM) at a blood lactate concentration of 4 mM. Distance running performance was determined by 3 km time-trials on an indoor 200 m track for which the average time was 9.46 +/- 0.74 min. The mean (+/-s) velocities for v-Tlac, v-4mM and v-VO2max were 16.0 +/- 1.8, 17.1 +/- 1.9 and 20.7 +/- 2.1 km h-1 respectively, all significantly different on average (all P < 0.05) from that for v-3km (19.1 +/- 1.5 km h-1). Many of these physiological variables were found to be individually (and significantly at 5%) related to v-3km. The best single predictors of v-3km were v-Tlac and v-4mM (both with a sample correlation, r2 of 0.93), while v-VO2max was slightly poorer (r = 0.86). Neither VO2 max nor running economy was strongly correlated with v-3km. A stepwise multiple-regression analysis revealed that v-Tlac alone was the best single predictor of v-3km and explained 87% of the variability in 3 km running velocity, while the addition of any of the other physiological variables did not significantly improve the prediction of v-3km. We conclude that, in a group of well-trained runners, the running velocity at the lactate threshold was all that was required to explain a large part of the variability in 3 km running performance.

Adolescent↗

Posttransplant lymphoproliferative disease in primary Epstein-Barr virus infection after liver transplantation: the role of cytomegalovirus disease.

Epstein-Barr virus (EBV) plays a major role in the pathogenesis of posttransplant lymphoproliferative disease (PTLD). Patients who undergo primary EBV infection after transplantation are at greater risk of developing PTLD. In this retrospective study, the incidence of EBV infection and associated PTLD in 40 consecutive adult recipients who were seronegative for EBV at the time of liver transplantation were investigated, and risk factors for PTLD were analyzed. Of 37 patients with available timely posttransplant serum samples, 35 (95%) developed primary EBV infection. Of the 40 patients, 13 (33%) developed PTLD a median of 126 days (range, 48-776) after liver transplantation. The factor significantly associated with the development of PTLD was cytomegalovirus disease (relative risk, 7.3; 95% confidence interval, 2.36-22.6; P = .0006). Cytomegalovirus disease is a predictor for the development of PTLD in primary EBV infection after liver transplantation, and it may be a target for prophylactic intervention.

Adult↗

Effects of requiring prior authorization for selected antimicrobials: expenditures, susceptibilities, and clinical outcomes.

Antimicrobial control programs are widely used to decrease drug expenditures, but effects on antimicrobial resistance and outcomes for patients are unknown. When a requirement for prior authorization for selected parenteral antimicrobial agents was initiated at our urban, county teaching hospital, total parenteral antimicrobial expenditures decreased by 32%. Susceptibilities to all beta-lactam and quinolone antibiotics increased, with dramatic increased susceptibilities in isolates recovered in intensive care units, increased susceptibilities in isolates recovered in other inpatient sites, and little change in susceptibilities in isolates recovered in outpatient sites despite no change in infection control practices. For patients with bacteremia due to gram-negative organisms, overall survival did not change with restrictions. No differences occurred in the median time from initial positive blood culture to receipt of an appropriate antibiotic or in the median time from positive blood culture to discharge from the hospital. Thus, requiring preapproval for selected parenteral agents can decrease antimicrobial expenditures and improve susceptibilities to antibiotics without compromising patient outcomes or length of hospital stay.

Acinetobacter↗

Comparison of intravenous ganciclovir followed by oral acyclovir with intravenous ganciclovir alone for prevention of cytomegalovirus and Epstein-Barr virus disease after liver transplantation in children.

A randomized trial was performed to compare the sequential use of 2 weeks of intravenous ganciclovir (10 mg/[kg.d]) followed by 50 weeks of high-dose oral acyclovir (800 mg/m2 four times daily) with 2 weeks of intravenous ganciclovir alone as prophylaxis for cytomegalovirus (CMV) and Epstein-Barr virus (EBV) disease after pediatric liver transplantation. CMV disease was diagnosed for seven of 24 patients treated with ganciclovir followed by high-dose oral acyclovir compared with two of 24 children treated with ganciclovir alone (P = .048). Similarly, the rate of CMV disease among high-risk patients (CMV-positive donor/CMV-negative recipient) treated with the combination regimen was higher than that among high-risk patients treated with ganciclovir alone (four [57%] of seven vs. zero of five, respectively; vs P < .05). The rate of EBV disease among patients treated with the combination regimen (eight [33%] of 24) was similar to that among patients treated with ganciclovir alone (five [21%] of 24; P = not significant). We conclude that sequential prophylaxis with 2 weeks of intravenous ganciclovir followed by 50 weeks of high-dose oral acyclovir did not decrease the frequency of CMV or EBV disease after pediatric liver transplantation when compared with 2 weeks of intravenous ganciclovir alone.

Acyclovir↗

The use of counterflow centrifugal elutriation for the depletion of T cells from unrelated donor bone marrow.

Transplantation of marrow from unrelated donors is associated with an increased incidence and severity of graft-versus-host disease (GVHD). In an attempt to minimize GVHD without compromising engraftment, unrelated donor marrow was depleted of lymphocytes by counterflow centrifugal elutriation (CCE), and a fixed dose of 0.5 x 10(6) CD3+ T cells/kg, as measured in real time by flow cytometry, was added back to the graft. Patients received cyclosporine (CYA) and corticosteroids for GVHD prophylaxis and to facilitate engraftment. In the first cohort (study I), 7 patients received busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) (CY) and one patient received CY (200 mg/kg) + 1260 cGy fractionated TBI. Of 6 who were evaluable for both engraftment and rejection, 4 rejected their graft. The study was terminated, and the protocol was modified (study II) by the addition of antithymocyte globulin (ATG) to the pre-BMT and post-BMT therapy. Twelve patients received CY + TBI as above plus ATG given pre-BMT and post-BMT. Ten of twelve who received ATG engrafted. Twelve patients from studies I and II were evaluable for acute GVHD. Two developed grade I acute GVHD. Two patients developed grade II acute GVHD, 2 patients developed grade III GVHD, and 1 patient developed grade IV acute GVHD. Two of three cases of acute GVHD (> grade II) occurred later than day 100 after BMT concomitant with reduction of immunosuppressive therapy. The rate of engraftment was significantly higher in study II (p = .054). In numbers of CD34+ cells infused, numbers of CFU-GM infused, and numbers of nucleated cells did not correlate with engraftment. We conclude that (a) in contrast to the results seen in recipients of marrow from HLA-matched sibling donors, the depletion of unrelated donor marrow of all but 0.5 x 10(6) CD34+ cells/kg together with CYA + corticosteroids was not sufficient to facilitate engraftment. The use of a more immunosuppressive regimen containing TBI and ATG appeared to improve engraftment. (b) The reduction of the graft T cell dose to 0.5 x 10(6) CD34+ cells/kg resulted in a higher incidence of acute GVHD than that seen in recipients of marrow from genotypically identical donors whose marrow was similarly processed.

Adolescent↗

Hepatic fatty acid synthase gene transcription is induced by a dietary copper deficiency.

A dietary copper (Cu) deficiency is associated with a twofold increase in hepatic fatty acid biosynthesis. We hypothesized that the induction of hepatic lipogenesis associated with a dietary Cu deficiency reflected an enhanced expression of genes encoding lipogenic enzymes, i.e., fatty acid synthase (FAS). Male weanling rats were pair-meal fed for 42 days a high-sucrose diet that was Cu deficient (CuD; 0.7 microgram Cu/g) or Cu adequate (CuA; 5.0 micrograms Cu/g). The CuD diet increased FAS enzymatic activity twofold (P < 0.05). This rise in enzymatic activity was accompanied by a threefold increase in FAS mRNA and a 2.5-fold increase in FAS gene transcription (P < 0.05). Neither the mRNA abundance nor the rate of gene transcription for phosphoenolpyruvate carboxykinase or beta-actin was affected by the CuD diet. The induction of FAS gene transcription was associated with a 65-85% increase in hepatic reduced glutathione (GSH; P < 0.05). When hepatic GSH synthesis was suppressed by treating CuD rats with L-buthionine sulfoximine, the induction of FAS expression was completely prevented. Similarly, feeding N-acetylcysteine to CuA rats increased hepatic GSH levels 2.5-fold, and this was accompanied by a significant induction in FAS expression. These data indicate that the increase in hepatic lipogenesis associated with a Cu deficiency reflects an induction in hepatic lipogenic gene transcription (i.e., FAS) and that the rate of gene transcription may be dependent on hepatic thiol redox.

Actins↗

Particulate bioglass compared with hydroxyapatite as a bone graft substitute.

Bioactive ceramics, notably hydroxyapatite, have been used clinically in various situations in which bone augmentation and restoration are required. Particulate material has been used either alone or in conjunction with freeze dried or autologous bone, with variable clinical success. In this study a bioactive glass, 45S5 Bioglass, has been compared with hydroxyapatite in an animal model to discover whether the 2 major disadvantages of hydroxyapatite may be overcome. These are the difficulty of placing and retaining the particulate in the defect and the length of time needed before full bony restoration is achieved. Bioglass is shown to be easy to manipulate and hemostatic and allows full restoration of bone in 2 weeks, rather than the 12 weeks needed for the particulate hydroxyapatite to produce a comparable response. The Bioglass particulate is used up in the process, and any problems that may be associated with the production of a composite of bone and biomaterial are avoided in the fully restored bone. In any procedure that requires bony augmentation, this rapid response to Bioglass is expected to provide a clinical advantage.

Animals↗

Stöckert roller pump generated pulsatile flow: cerebral metabolic changes in adult cardiopulmonary bypass.

There is evidence that during cardiopulmonary bypass (CPB), pulsatile pump flow improves cerebral metabolism. This was a study to explore the effect of pulsatile versus nonpulsatile perfusion on cerebral lactate, pyruvate, glucose and beta-hydroxybutyrate using a Stöckert roller pump. We found no significant differences between the arterial-venous (A-V) differences of lactate, glucose and beta-hydroxybutyrate (p > 0.05). When the upward trend of A-V pyruvate was accounted for, there was again no difference (p = 0.2). Arterial lactate:pyruvate ratios were not significantly different between pulsatile and nonpulsatile pump flow (p > 0.05). Venous lactate:pyruvate ratios were significantly higher during pulsatile bypass, but when the downward trend was accounted for, the differences between pulsatile and nonpulsatile values were no longer significant (p = 0.4). Therefore, the metabolic changes were not significant. There was no significant difference in systemic vascular resistance (SVR) during pulsatile and nonpulsatile flow (p = 0.4). Pulsatile flow delivered by the Stöckert roller pump appears to have no metabolic or SVR advantages in adults undergoing CPB.

3-Hydroxybutyric Acid↗

Human mucosal addressin cell adhesion molecule-1 is preferentially expressed in intestinal tract and associated lymphoid tissue.

Lymphocyte homing to normal tissues and recruitment to inflammatory tissue sites are controlled, in part, by the selective expression of chemokines, pro-inflammatory cytokines and mediators, and various adhesion proteins and molecules. In the mouse, mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is selectively expressed on endothelium of high endothelial venules in gut and gut-associated lymphoid tissue. By interaction with its integrin ligand, alpha 4 beta 7, lymphocytes presumed to be involved in mucosal immunity are selectively recruited to these intestinal sites. After generating monoclonal antibodies against a murine cell line expressing recombinant human MAdCAM-1, we qualitatively and semiquantitatively assessed MAdCAM-1 expression in human tissue sections from various normal and inflammatory disorders. We found that human MAdCAM-1, as in the mouse, is expressed in a tissue-selective manner. In normal tissues, MAdCAM-1 is constitutively expressed to endothelium of venules of intestinal lamina propria. Interestingly, using computer-assisted morphometric analysis, the proportion of venular endothelium within lamina propria that expresses MAdCAM-1 is increased, compared with normal tissues, at inflammatory foci associated with ulcerative colitis and Crohn's disease. Moreover, for the most part, MAdCAM-1 is not detected in the majority of normal or inflamed extra-intestinal tissues, including those with mucosal surfaces. These results are consistent with a role, as originally defined in the mouse, for human MAdCAM-1 in the localization of alpha 4 beta 7+ lymphocytes in the gastrointestinal tract and associated lymphoid tissue. As such, the pathway defined by MAdCAM-1/alpha 4 beta 7 may be a relevant tissue-specific therapeutic target for the modulation of inflammatory bowel disease activity.

Animals↗