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Biomedical subjects

T C Merigan

Publications and source records attributed to T C Merigan.

At least 271 records · Page 15Linked to original sources
PubMed1978

Human leukocyte interferon for the treatment of herpes zoster in patients with cancer.

We tested the effect of human leukocyte interferon on early localized herpes zoster infections in three placebo-controlled, randomized double-blind trials involving 90 patients with cancer. There were no significant differences in pretreatment severity of infection or nature of underlying disease in the groups. Higher dosages of more purified interferon in the second and third trials produced a significant (P less than or equal to 0.01) decrease in cutaneous dissemination. No dissemination occurred in those receiving the highest dosage (5.1 x 10(5) U per kilogram per day) (P less than or equal to 0.025). The number of days of new-vesicle formation in the primary dermatome decreased (mean, 2.3 days, P less than or equal to 0.05) in this group. Treated patients had a trend toward less acute pain, and significantly (P less than or equal to 0.05) diminished severity of post-herpetic neuralgia, at the two highest dosage levels. Visceral complications were six times less frequent in interferon recipients. High-dosage interferon appeared effective in limiting cutaneous dissemination, visceral complications and progression within the primary dermatome.

Blood Cell Count↗
PubMed1978

Role of T lymphocytes in cellular immune responses during herpes simplex virus infection in humans.

Lymphocyte blast transformation and interferon production in mononuclear cell culture prepared on Ficoll-Hypaque gradients from individuals with herpes simplex virus-I infection were enhanced by a disease recurrence. Responses to both herpes simplex virus-2 and phytohemagglutinin were unaltered. Transformation to herpes simplex virus-I antigen was adversely affected by depleting either thymus-derived (T) lymphocytes or bone marrow-derived (B) lymphocytes together with monocytes from cultures. The transformation response was reconstructed when the selectively depleted lymphocyte populations were recombined. X-irradiation of either T or B lymphocytes and monocytes showed that T lymphocytes incorporated [3H]thymidine with the aid of a radioresistant non-rosetting cell, probably a monocyte. Depletion of B lymphocytes and monocytes, but not of T lymphocytes, resulted in reduction in interferon production. Irradiated B lymphocytes and monocytes failed to produce significant quantities of interferon, suggesting that a radiosensitive B cell was a major interferon source.

Antigens, Viral↗
PubMed1978

Selective impairment of lymphocyte reactivity to varicella-zoster virus antigen among untreated patients with lymphoma.

Herpes zoster is a frequent complication of lymphoreticular malignancy. In this study two assays of in vitro cellular immune response to varicella-zoster virus (VZV) antigen, lymphocyte transformation and interferon production, were performed in normal subjects with recent and remote VZV infection. The responses of patients with lymphoma were measured before treatment and during long-term remission and then compared with those of normal subjects. Despite levels of antibody to VZV that were equivalent to those in normal subjects, 44% of the untreated lymphoma patients showed a lower transformation response to VZV antigen than the normal patients. Production of interferon in response to VZV antigen was absent in 32% of the untreated patients. In contrast, lymphocyte responses in untreated patients to herpes simplex virus antigen were within the range observed in a normal population. Interferon production by lymphocytes in response to cytomegalovirus antigen was also lower among untreated lymphoma patients than among normal patients, but lymphocyte transformation was not. Twenty-two percent of lymphoma patients in long-term remission continued to have diminished cellular immune responses to VZV antigen. Observations in these patient populations and in normal subjects with acute herpes zoster suggest that deficiencies in in vitro lymphocyte responses may correlate with increased susceptibility to clinical infection with VZV.

Antibodies, Viral↗
PubMed1978

Cell-mediated immunity of cytomegalovirus infection in normal subjects and cardiac transplant patients.

Two assays of cell-mediated immunity, lymphocyte transformation and interferon production, were adapted to test for specific immunity to cytomegalovirus (CMV). Normal individuals seropositive for CMV had a mean transformation index of 7.9 in response to antigen of the Davis strain of CMV, whereas all of 14 seronegative normal individuals had transformation indexes of less than or equal to 3.0. Interferon production in seropositive and seronegative individuals was not statistically different. One to two months after CMV mononucleosis (after the termination of viruria), normal individuals had increased transformation indexes. Recipients of cardiac transplants within six months after transplant had normal levels of antibody to CMV; lymphocyte transformation and interferon production in these subjects were markedly decreased and returned to normal by three years and between one and three years after transplant, respectively. A syndrome of unexplained fever, hepatitis, pneumonitis, leukopenia, and atypical lymphocytes was common in a group of recipients with primary CMV infection. Shedding of virus was frequent in these symptomatic patients and in patients with repeat infection during the first three years after transplant. These assays appear to identify periods of immune deficits correlating with increased incidence of infection with CMV.

Cytomegalovirus Infections↗
PubMed1978

Factors affecting the interferon sensitivity of human cytomegalovirus.

Several factors affected the interferon sensitivity of human cytomegalovirus in human foreskin fibroblast cultures. An inoculum of infected cells was up to 300-fold less sensitive than a cell-free inoculum of equivalent input multiplicity. A 10-fold increase in the dose of infectious units of either type of inoculum was associated with a 10-fold or greater decrease in interferon sensitivity. Several aspects of the virus-cell interaction were examined and parameters indicative of cell infection were less inhibited by interferon than were those for virus replication.

Acridines↗
PubMed1978

Lymphocyte transformation and interferon production as measures of cellular immunity in lymphoma patients.

Our studies of in vitro cellular immune responses to herpesviruses have shown that, before treatment, lymphoma patients have decreased transformation to varicella-zoster virus antigen compared to herpes simplex virus and cytomegalovirus antigens. Interferon production to varicella-zoster virus and cytomegalovirus antigens is also decreased. During the first six months of treatment, decreased lymphocyte transformation and interferon production to all herpesviral antigens was observed. Among patients in long-term remission, recovery from the suppression associated with treatment was noted except that interferon production to varicella-zoster virus antigen remained decreased.

Antigens, Viral↗
PubMed1977

Cellular immunity and herpesvirus infections in cardiac-transplant patients.

We observed severe infection with herpes simplex virus in cardiac-transplant patients despite their high serum antibody levels to this virus. Therefore, we sought to correlate clinical susceptibility to two herpesvirus (simplex and zoster) infections with specific cellular immunity, assessed by the transformation and interferon responses of peripheral blood mononuclear cells to heat-inactivated antigens. Transformation and interferon response to herps simplex virus was maximally depressed immediately after transplantation, the time when severe and prolonged infection with herps simplex virus occurred. Six months to six years after transplantation, both clinical susceptibility and cellular immunity to herpes simplex virus were normal. Herpes zoster infections were more frequent than normal at all times after cardiac transplantation; depressed or absent cellular responses to the varicella zoster virus paralleled that susceptibility. In these patients the risk of severe herpesvirus infections correlated with depressed cellular immune responses to the specific viral agent involved.

Antibodies, Viral↗
PubMed1977

Adenine arabinoside in the treatment of progressive multifocal leukoencephalopathy: use of virus-containing cells in the urine to assess response to therapy.

Two patients with biopsy-proved progressive multifocal leukoencephalopathy (PML) were treated with near-maximal doses of adenine arabinoside (Ara-A), 18.6 and 20 mg per kilogram of body weight per day for 14 days. In both patients, clinical progression of the disease was correlated with an increase in the size of low-density lesions seen by computerized tomography. One of the patients was observed to excrete abnormal epithelial cells into the urine. These cells contained papovaviruslike particles, and JC virus was cultured from the urine sediment. The relative number of these abnormal cells declined during Ara-A treatment. Both patients died shortly after the conclusion of therapy without a change in the progression of the central nervous system disease. Systemic administration of Ara-A did not offer significant clinical benefit in the treatment of these 2 advanced cases of PML.

Aged↗
PubMed1977

Multiplicity-dependent replication of varicella-zoster virus in interferon-treated cells.

The inhibitory effects of interferon (IF) on the replication of varicella-zoster (VZ) virus in human foreskin fibroblast (HFF) cultures inoculated with infected cells or with cell-free virus were assayed by measuring (1) yields of infected cells, (2) plaques, (3) microfoci and (4) cytopathic effects. More IF was needed to reduce yields of infected cells at high input multiplicities of challenge than at low input multiplicites, and still more IF was needed to prevent cytopathology due to VZ virus. A cell-free virus inoculum was more sensitive to the inhibitory effects of IF than an inoculum of infected cells. With the latter, but not with cell-free virus, the continuous presence of IF in the medium was necessary for it to express its maximum antiviral activity. To explain these results, it is suggested that some herpesviruses may establish "reservoirs' of infectivity and thus provide a prolonged challenge to IF-treated cells which are not uniformly resistant to infection.

Cell Line↗