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C Pomeroy

Publications and source records attributed to C Pomeroy.

At least 55 records · Page 3Linked to original sources
PubMed1991

Phenotypes, proliferative responses, and suppressor function of lung lymphocytes during Toxoplasma gondii pneumonia in mice.

Toxoplasma gondii pneumonia has emerged as an important problem in immunocompromised patients, especially those with AIDS. The characteristics of lung lymphocytes, including their phenotypes, proliferative responses, and suppressor function during T. gondii pneumonia were studied. During primary acute T. gondii infection, the numbers of T lymphocytes in the lungs increased even though mice lacked histologic evidence of pneumonia. As mice recovered from acute toxoplasmosis, numbers of lung CD4+ cells and the ratio of CD4+ to CD8+ cells decreased. Subsequently, T. gondii infection reactivated, manifested as pneumonia. During pneumonia, lung T lymphocytes, especially CD8+ cells, increased even more. Lung lymphocytes from mice with T. gondii pneumonia decreased the proliferative responses of splenocytes from T. gondii-immune mice to both concanavalin A and T. gondii lysate antigens in vitro. The striking increase in lung CD8+ cells and suppressor activity appear to be integral to the pathogenesis of T. gondii pneumonia.

Acute Disease↗
PubMed1991

Effect of clindamycin on pneumonia from reactivation of Toxoplasma gondii infection in mice.

Clindamycin was used to treat the reactivation of a chronic Toxoplasma gondii infection in mice. Clindamycin reduced mortality by 44% when used prophylactically (P less than 0.001) but appeared to be less effective when used to treat clinically apparent reactivation. Further studies should be conducted to establish the efficacy of clindamycin for the treatment of toxoplasmosis in humans.

Animals↗
PubMed1991

Latent murine cytomegalovirus DNA in splenic stromal cells of mice.

Latency is an integral feature of the pathogenesis of cytomegalovirus infection and disease. Using in situ hybridization, we detected viral DNA in the splenic stroma of mice with acute murine cytomegalovirus (MCMV) infection but could not detect latent infection. By using enzymatic amplification of a 700-bp region of exon 4 of immediate-early gene 1 of MCMV, viral DNA was consistently detected in whole spleens of latently infected mice. MCMV DNA was detected in 16 of 23 stromal cell fractions from latently infected animals, in only 2 of 13 residual nonstromal cell fractions, and in none of 9 additional lymphocyte or macrophage-enriched nonstromal cell preparations. We conclude that MCMV DNA is maintained predominantly, and possibly exclusively, in stromal cells in the spleens of latently infected mice.

Animals↗
PubMed1991

Infection in the myelodysplastic syndromes.

PURPOSE: To determine the incidence, characteristics, and outcome of infection in patients with myelodysplastic syndromes (MDS) and risk factors that may lead to infection. PATIENTS AND METHODS: We reviewed infections that occurred in 86 consecutive patients with MDS who received care from 1968 to 1986 at a university-affiliated Veterans Affairs Medical Center. Time lines charting the course of each patient with MDS were created and included infections, MDS subgroup at the time of presentation and at the time of each infection, peripheral neutrophil counts, and therapies for MDS. RESULTS: Infections occurred at a rate of nearly one per patient year of observation. Infection rates were associated with MDS subgroup as follows: refractory anemia with or without ringed sideroblasts (RA +/- RS) less than refractory anemia with excess blasts (RAEB) less than RAEB in transformation (RAEB-T). The group of RA +/- RS patients who had erythroid abnormalities but minimal or no dyspoiesis of other cell lines had the lowest rate of infections. Infection rates were higher in patients with less than or equal to 1,000 neutrophils/microL blood than in patients with greater than 1,000 neutrophils/microL blood for each classifiable MDS subgroup. Neutrophil concentration and MDS subgroup were independent risk factors for infection in patients with MDS. Bacterial pneumonias and skin abscesses were the most common infections. Infection was the most common cause of death during MDS, accounting for 64% of deaths, and was more common than transformation to acute leukemia as a cause of death. CONCLUSION: Infection is a common, life-threatening problem in patients with MDS. Neutropenia and MDS subgroup are each risk factors for infection. Clinicians should aggressively evaluate patients with fever and MDS for infection, especially pneumonia and skin infections.

Adult↗
PubMed1990

A comparison study of antidepressants and structured intensive group psychotherapy in the treatment of bulimia nervosa.

Previous research on the treatment of outpatients with bulimia nervosa has focused on two treatment strategies: (1) drug therapy, primarily using tricyclic antidepressants, and (2) psychotherapy, often employing behavioral and cognitive behavioral techniques. We report here the short-term treatment outcome of a 12-week comparison trial of bulimic outpatients who were randomly assigned to one of four treatment cells: (1) imipramine hydrochloride treatment, (2) placebo treatment, (3) imipramine treatment combined with intensive group psychotherapy, and (4) placebo treatment combined with intensive group psychotherapy. All three active treatment cells resulted in significant reductions in target-eating behaviors and in a significant improvement in mood relative to placebo treatment. However, the results also suggested that the amount of improvement obtained with the intensive group psychotherapy component was superior to that obtained with antidepressant treatment alone. The addition of antidepressant treatment to the intensive group psychotherapy component did not significantly improve outcome over intensive group psychotherapy combined with placebo treatment in terms of eating behavior, but did result in more improvement in the symptoms of depression and anxiety.

Adolescent↗
PubMed1990

Effects of immobilization stress on the pathogenesis of acute murine toxoplasmosis.

Stress modulates a variety of immune responses. We investigated the effects of immobilization stress on the pathogenesis of acute murine toxoplasmosis, an infection in which cell-mediated immunity is of major importance in host defense. Repetitive overnight immobilization beginning 3 days prior to infection enhanced (p less than 0.05) the mortality of mice infected with a virulent strain (C56) of Toxoplasma gondii (77% vs 15% mortality in restrained and control mice, respectively). Daily immobilization for 14 days prior to infection abrogated (p less than 0.05) the lethal effect of immobilization, suggesting an adaptive mechanism. To explore the effect of immobilization with a less virulent strain, the Me49 strain of T. gondii was studied. Acute infection with T. gondii Me49 resulted in anorexia and weight loss, while spleen size and respiratory burst activity of peritoneal exudate cells were enhanced (p less than 0.01). Immobilization (twice daily for 2 h) did not significantly alter survival or other clinical features of acute T. gondii infection. In addition, immobilization suppressed (p less than 0.05) phorbol myristate acetate-stimulated release of superoxide anion by peritoneal exudate cells in healthy naive mice, but not in infected mice. These findings indicate that immobilization stress can alter the pathogenesis of acute T. gondii infection in healthy mice, but the effect of this stress paradigm will be influenced, in part, by the timing of the immobilization and the virulence of the strain of T. gondii.

Animals↗
PubMed1990

Maintenance treatment and 6-month outcome for bulimic patients who respond to initial treatment.

Bulimic subjects who responded to intensive group psychotherapy plus imipramine or placebo or to imipramine alone (N = 68) were assigned to 4-month maintenance with weekly support groups and/or medication (placebo or imipramine) and were evaluated 6 months after initial treatment (N = 61). Thirty percent of the subjects relapsed during the 6 months. Initial treatment with group psychotherapy plus placebo or imipramine was associated with a lower relapse rate than initial treatment with imipramine alone. Neither attendance at the maintenance group sessions nor imipramine maintenance was associated with better outcome.

Adolescent↗
PubMed1990

Augmentation ileocystoplasty in children with myelodysplasia.

Over the past 8 years 20 children suffering from myelodysplasia were selected to undergo augmentation ileocystoplasty for urinary incontinence refractory to treatment by clean, intermittent catheterization and anticholinergic agents, or as part of urinary undiversion. The children ranged in age from 5 to 17 years, and the follow-up ranged from 6 months to 7 years. Three children underwent undiversion, two had vesicostomy closure and six had bladder outlet repair at the time of augmentation. In one patient, surgery was technically impossible. Postoperatively 16 children were fully continent on clean, intermittent catheterization and anticholinergic medication. Three boys failed to achieve satisfactory continence. Delayed perforation, a potentially serious complication, occurred in two patients several months postoperatively.

Adolescent↗
PubMed1990

Lethality of morphine in mice infected with Toxoplasma gondii.

Opiates modulate a variety of immune responses. We investigated the effect of morphine on the pathogenesis of an acute Toxoplasma gondii infection. Repeated s.c. injections with morphine sulfate (300 mg/kg) every 36 hr addicted mice and increased markedly the mortality of mice infected with an avirulent strain of T. gondii (86%) vs. 0% mortality in addicted and control mice, respectively, P less than .001). However, a single challenge with morphine (300 mg/kg) also markedly (P less than .001) increased mortality (94%) of infected mice when the morphine was administered at day 13 postinfection; susceptibility to the lethal effect was not observed until day 9 postinfection, a time when immune reactivity was evident (i.e., 3- to 4-fold splenic enlargement). This lethal effect was attenuated by pretreatment with naltrexone, suggesting involvement of an opiate receptor mechanism. Sulfadiazine treatment abrogated morphine-induced mortality, indicating a prerequisite of an active infectious state. These findings suggest that immune activation by T. gondii infection plays a critical role in morphine-induced mortality in this murine model.

Animals↗
PubMed1989

Reactivation of Toxoplasma gondii by cytomegalovirus disease in mice: antimicrobial activities of macrophages.

Reactivation of Toxoplasma gondii infection often occurs concurrently with active cytomegalovirus (CMV) disease in immunocompromised patients, and CMV disease results in immunosuppression. To determine if murine CMV (MCMV) infection decreases resistance to T. gondii, mice with latent T. gondii infection were infected with MCMV. T. gondii infection reactivated, manifested primarily as pneumonia. Lung macrophages supported the growth of T. gondii before, during, and after T. gondii reactivation. Peritoneal macrophages inhibited the growth of T. gondii as pneumonia developed and became permissive as pneumonia resolved. Mice with latent T. gondii infection could survive larger doses of MCMV than could controls. Thus, MCMV infection led to reactivation of latent T. gondii infection in mice. Activation of lung macrophages, assessed by their ability to inhibit replication of T. gondii in vitro, was not associated with control of T. gondii infection.

Animals↗
PubMed1989

A placebo-controlled, double-blind crossover study of naltrexone hydrochloride in outpatients with normal weight bulimia.

The endogenous opioid system plays an important role in the control of feeding behavior. Previous research has shown that antagonism of endogenous opioids will suppress feeding in certain models in both human and infrahuman species. In the current study, 16 normal-weight bulimic women were treated with low-dose naltrexone, the long-acting, orally active narcotic antagonist, and placebo in a crossover design. The use of the active drug was not associated with a clinically significant reduction in binge eating or vomiting episodes. Suggestions for further research in this area are offered.

Adult↗
PubMed1989

Response to alternative antidepressants in imipramine nonresponders with bulimia nervosa.

The authors report the results of open-label antidepressant trials in a series of normal weight bulimic women who showed an inadequate response to an initial trial of imipramine hydrochloride as part of a treatment comparison study. The results indicate that a significant percentage of subjects responded to a second trial of an alternative agent. Overall, 47% had a complete remission of symptoms during the second trial, usually with a monoamine oxidase inhibitor or fluoxetine. The authors stress the importance of persisting in trials of alternative agents if bulimic patients fail to respond to an initial trial.

Adolescent↗
PubMed1988

Effect of intravenous silica on the course of Nocardia asteroides pneumonia.

Silica, a known toxin of mononuclear phagocytes, was administered intravenously to mice during Nocardia asteroides pneumonia. Mice that received silica had a sevenfold decrease in the number of peripheral blood monocytes and developed more severe N. asteroides pneumonia than control mice. Lung histology in mice that received silica resembled that of mice with impaired cell-mediated immunity. These results are most consistent with the explanation that silica injures blood monocytes and impairs their contributions to pulmonary host defense.

Animals↗
PubMed1988

Diuretic use as a marker for eating problems and affective disorders among women.

Fourteen female symptomatic volunteers between the ages of 18 and 40 who used diuretics on a regular basis for reasons that were not medically necessary were evaluated. Seven (50%) were diagnosed as having a current or past syndromal or subsyndromal eating disorder, and 9 (64%) were diagnosed as having a current or past affective disorder. The results of this pilot study suggest that chronic diuretic use in young women should signal to the clinician the possibility of an unrecognized eating problem and/or an affective disorder.

Adolescent↗
PubMed1988

Prescription diuretic abuse in patients with bulimia nervosa.

Bulimia nervosa, a common eating disorder usually characterized by binge eating and self-induced vomiting, may also involve abuse of prescription diuretics. This article describes four patients who abused prescription diuretics in large quantities (up to 2 g/d of furosemide) for extended periods of time. Physical examination and laboratory values provided few clues to the diagnosis of bulimia nervosa. Other eating-related behaviors previously linked to bulimia nervosa--including abuse of diet pills, illicit amphetamines, and laxatives, as well as withholding of insulin in one diabetic patient--were present in these cases. Usually the patients' primary physicians were not aware of these problems. Physicians should be aware that patients requesting prescription diuretics may have bulimia nervosa.

Adult↗