Drug therapy: antiviral agents (second of two parts)

Bias against Vitamin C in Mainstream Medicine: Examples from Trials of Vitamin C for Infections

Evidence has shown unambiguously that, in certain contexts, vitamin C is effective against the common cold. However, in mainstream medicine, the views on vitamin C and infections have been determined by eminence-based medicine rather than evidence-based medicine. The rejection of the demonstrated benefits of vitamin C is largely explained by three papers published in 1975-two published in JAMA and one in the American Journal of Medicine-all of which have been standard citations in textbooks of medicine and nutrition and in nutritional recommendations. Two of the papers were authored by Thomas Chalmers, an influential expert in clinical trials, and the third was authored by Paul Meier, a famous medical statistician. In this paper, we summarize several flaws in the three papers. In addition, we describe problems with two recent randomized trial reports published in JAMA which were presented in a way that misled readers. We also discuss shortcomings in three recent JAMA editorials on vitamin C. While most of our examples are from JAMA, it is not the only journal with apparent bias against vitamin C, but it illustrates the general views in mainstream medicine. We also consider potential explanations for the widespread bias against vitamin C.

A case of herpes simplex virus pneumonia detected by sputum cytodiagnosis

A sputum test is noninvasive and simple. It contributed to correct diagnosis of a patient with severe acute respiratory failure. We again point out the usefulness of sputum cytodiagnosis for differentiating severe pneumonia.

Herpes Simplex Virus-1 Encephalitis in Adults: Pathophysiology, Diagnosis, and Management

Herpetic infections have plagued humanity for thousands of years, but only recently have advances in antiviral medications and supportive treatments equipped physicians to combat the most severe manifestations of disease. Prompt recognition and treatment can be life-saving in the care of patients with herpes simplex-1 virus encephalitis, the most commonly identified cause of sporadic encephalitis worldwide. Clinicians should be able to recognize the clinical signs and symptoms of the infection and familiarize themselves with a rational diagnostic approach and therapeutic modalities, as early recognition and treatment are key to improving outcomes. Clinicians should also be vigilant for the development of acute complications, including cerebral edema and status epilepticus, as well as chronic complications, including the development of autoimmune encephalitis associated with antibodies to the N-methyl-D-aspartate receptor and other neuronal cell surface and synaptic epitopes. Herein, we review the pathophysiology, differential diagnosis, and clinical and radiological features of herpes simplex virus-1 encephalitis in adults, including a discussion of the most common complications and their treatment. While great progress has been made in the treatment of this life-threatening infection, a majority of patients will not return to their previous neurologic baseline, indicating the need for further research efforts aimed at improving the long-term sequelae.

Trial with human leucocyte interferon and vidarabine in herpes simplex virus encephalitis: diagnostic and therapeutic problems

A combination therapy of human interferon, vidarabine, and dexamethasone was administered to six patients with proven (Patients I-III) or presumed (Patients IV-VI) herpes simplex virus encephalitis (HSVE). Interferon combined with dexamethasone was given to one patient with presumed HSVE (Patient VII). Leucopenia and elevated serum transaminase levels appeared in all patients and a diffuse bleeding in one of them. Patients II, III and IV died, 26, 43, and 209 days after the onset of encephalitis, respectively. Patients I, V, VI, and VII were left with moderate brain damage although their physical condition was good. HSV encephalitis presents diagnostic difficulties, complementary diagnostic methods are needed, and current therapeutic trials must be considered as preliminary.

Antiviral and antiretroviral use in pregnancy

The history of antiviral and antiretroviral therapy is recent compared with many other medical therapies, including traditional antibiotics in pregnancy. There are few long-term data on which to base decisions of management in pregnancy. Accessing up-to-date information is critical to optimizing the safety of care for mothers and their infants. Exposure to medications in pregnancy can be toxic to a fetus in a gestational age-dependent manner. Determination of safe medications for pregnancy must take into consideration the need for certain medications and the possibility of inadvertent exposure in early pregnancy because of unplanned pregnancies. This article reviews the most commonly used antiviral and antiretroviral agents and places emphasis on the issues regarding use in pregnancy.

Perinatal herpesvirus infections. Herpes simplex, varicella, and cytomegalovirus

The herpesvirus infections (herpes simplex, varicella, and cytomegalovirus) create many dilemmas when encountered during pregnancy. This article reviews the epidemiologic diagnosis and management of perinatal herpesvirus infections. A review of possible future trends is also included.

Effects of natural interferon alpha, natural tumor necrosis factor alpha and their combination on human mesothelioma xenografts in nude mice

Effects of human natural interferon alpha (nIFN) alone, human natural tumor necrosis factor alpha (nTNF) alone and their combination (OH-1) were tested on three human mesothelioma lines implanted in nude mice. Tumors were transplanted subcutaneously by trocar on treatment day -12. nIFN was given intraperitoneally (i.p.) at a dose of 2 x 10(7) or 2 x 10(8) IU kg-1 day-1, 5 days a week for 3 weeks. nTNF was given i.p. at a dose of 2 x 10(7) or 2 x 10(8) U kg-1 day-1 in the same schedule as that of nIFN. Tumor diameters were serially measured and tumor volumes were calculated. Antitumor effects were assessed by two methods: comparison of final tumor volumes in treated and control groups (T/C), and changes in median average total tumor volume. The treatment produced no clinically discernible toxicities. nIFN had strong inhibitory activity against all three human mesothelioma lines. nTNF alone had modest activity only at the high dose used. The combination of the two produced activity essentially similar to that produced by nIFN alone. High-dose nIFN may have a role as an active agent in the treatment of patients with mesothelioma.

Treatment with human gamma interferon of chronic hepatitis B: comparative study with alpha interferon

A pilot study was designed to determine the tolerance and effectiveness of natural or recombinant gamma interferon in patients with chronic hepatitis B. Sixteen patients received 0.5 to 3.0 million units (MU) per day of gamma interferon (IFN-gamma) for 7 days. Nineteen chronic hepatitis B patients who were treated with 5-6 MU leukocyte-derived alpha interferon (IFN-alpha) daily served as controls. All completed the treatment schedule. IFN-gamma exerted mild, but significant inhibitory effects (P less than .05) on serum DNA polymerase levels. However, the changes were significantly less (P less than .001) than those seen with IFN-alpha therapy when compared with percent change from basal values. In contrast, serum 2', 5'-oligoadenylate synthetase (2-5 AS) activities were markedly enhanced to a similar extent during therapy with both IFNs. Serum beta 2-microglobulin values were significantly increased by administration with both IFNs, although higher values were seen with IFN-gamma. Five patients received 1 MU IFN-gamma for 28 consecutive days and their HBeAg levels similarly decreased as those seen in patients treated with IFN-alpha. Side effects seemed to be greater during IFN-gamma therapy than IFN-alpha despite the lower doses used. The antiviral effect on serum HBV levels appeared less with IFN-gamma than with IFN-alpha. Alternatively immunomodulatory functions may have been enhanced with IFN-gamma in patients with chronic HBV infection.

Effect of sizofiran, a polysaccharide, on interferon gamma, antibody production and lymphocyte proliferation specific for hepatitis B virus antigen in patients with chronic hepatitis B

To examine whether sizofiran (SPG), a polysaccharide isolated from Schizophyllum commune Fries, could modulate the immune response of immunocompetent cells to hepatitis B virus (HBV) nucleocapsid antigens, we investigated in vitro the production of interferon-gamma (IFN-gamma) and antibody (antibody to HB core and e antigens; anti-HBc and anti-HBe), and proliferation by peripheral blood mononuclear cells (PBMC) from six patients with chronic hepatitis B and four control individuals in the presence of recombinant HBcAg and purified HBeAg. Sizofiran alone in culture and in combination with HBV Ag was found to enhance IFN-gamma production and the proliferative response of PBMC from the patients compared with corresponding medium or HBV Ag alone culture. In contrast, antibody production was not elicited by SPG alone, but amplified by the drug in HBcAg-stimulated culture. In vitro leukocyte IFN-alpha addition increased IFN-gamma production, but suppressed the proliferation of PBMC from both controls and patients in the presence or absence of SPG and HBV Ag. These results indicate that SPG is able to modulate both cellular and humoral immune responses specific for nucleocapsid antigens in patients with chronic hepatitis B.

Effects of TJ-9 Sho-saiko-to (kampo medicine) on interferon gamma and antibody production specific for hepatitis B virus antigen in patients with type B chronic hepatitis

To examine whether Sho-saiko-to (kampo medicine) could modulate the immune response of immunocompetent cells to hepatitis B virus (HBV)-associated antigens, we investigated in vitro interferon gamma (IFN-gamma) and antibody (antibody to HB core and e antigens; anti-HBc and anti-HBe) production by peripheral blood mononuclear cells (PBMC) from eight patients with chronic active hepatitis (CAH) (four with HBeAg and four with anti-HBe) in the presence of recombinant HBcAg and purified HBeAg. IFN-gamma and antibody production were measured using ELISA and RIA, respectively. PBMC from both HBeAg and anti-HBe positive patients generated significantly increased IFN-gamma and antibody (anti-HBc and anti-HBe) production in the culture containing Sho-saiko-to (TJ-9) in a dose-dependent manner in comparison with those of medium alone culture. Similarly, when various concentrations of TJ-9 were added to the HBV antigen-stimulated cultures, TJ-9 was found to enhance both IFN-gamma and antibody production dose-dependently. These results indicate that TJ-9 is able to modulate both cellular and humoral immune responses specific for HBV-associated antigens. These findings also may account for, at least in part, the efficacy of TJ-9 treatment for type B chronic hepatitis.

Production of tumor necrosis factor, interleukin 1, and interferon-gamma by peripheral blood mononuclear cells from patients with primary biliary cirrhosis

Since patients with primary biliary cirrhosis (PBC) have evidence of abnormal function of the immune system, we evaluated production of various cytokines by peripheral blood mononuclear cells (PBMCs) and monocytes from patients with this disease, using an enzyme-linked immunosorbent assay. The mean amounts of production of tumor necrosis factor alpha(TNF alpha), interleukin 1 beta (IL1 beta), and interferon-gamma (IFN-gamma) by PBMCs from patients with PBC tended to be increased in cultures in the presence of stimulating agents in comparison with controls, but there was no significant difference because of a wide scatter of results. Monocytes from PBC patients also tended to produce higher amounts of TNF alpha and IL1 beta than control monocytes did, although the percentage of monocytes in PBMCs was similar in PBC and controls. A significant correlation was found between TNF alpha production and IL1 beta production in PBC patients. The number of TNF alpha or IFN-gamma positive infiltrating mononuclear cells detected by immunohistochemical staining in liver biopsy sections correlated with the production of these cytokines by PBMCs in vitro. However, cytokine production did not correlate with serum biochemical or hepatic histologic findings, except for serum alkaline phosphatase values. In patients with type B chronic active hepatitis, IL1 beta and IFN-gamma production was similar to controls, while TNF alpha production tended to be enhanced. Thus the cytokines studied here may play some role in the pathogenesis of PBC.

Intraventricular interferon treatment for subacute sclerosing panencephalitis

Three children with subacute sclerosing panencephalitis (SSPE) were treated with alpha-interferon. Medication was administered via an Ommaya reservoir into the cerebral ventricular system over a period of 13 to 24 months in increasing amounts up to 1.0 x 10(6) IU twice weekly. Mild clinical improvement in two children and a stable course in the third were associated with improvement of electroencephalographic recordings in all patients and a decrease in antimeasles antibodies in the cerebrospinal fluid of two. The small number of patients does not enable us to determine whether this course was the natural history of SSPE in our patients or whether it was induced by treatment, yet it seems that intraventricular interferon treatment can modify the course of SSPE.

Effect of rolling on foci development and viral replication for herpes simplex virus (HSV)

The effect of rolling on the number of herpes simplex virus (HSV) foci and yield of infectious virus was examined for cultures inoculated with clinical specimens. Inoculated cultures were either rolled at 2 revolutions per minute (rpm) or held stationary. Cultures that were rolled at 2 rpm showed a significantly greater number of foci and plaque forming units (PFU) over stationary cultures. The geometric mean fold increase in PFU between rolled and stationary cultures was 8-fold. Rolling of inoculated cultures should be used in the clinical virology laboratory to aid in the rapid detection of HSV.

Interferon-gamma production by peripheral blood mononuclear cells of patients with chronic liver disease

We investigated the role of the interferon system in the pathogenesis of chronic liver disease. Interferon-gamma production by peripheral blood mononuclear cells was measured with an ELISA. While concanavalin A-stimulated and recombinant interleukin 2-stimulated production of interferon-gamma in patients with chronic active hepatitis and liver cirrhosis was significantly decreased when compared with that of controls (518 +/- 189 and 729 +/- 195 units per ml, mean +/- S.D.), there was also a lot of overlap. Addition of indomethacin to the cultures partially restored interferon-gamma production in patients with chronic active hepatitis and liver cirrhosis, indicating that suppressor function of monocytes was, in part, responsible for the diminished interferon-gamma production. Serial studies showed that interferon-gamma production rose during acute deterioration of illness, during treatment with interleukin 2 and with the improvement of clinical course. Interferon-gamma production was not different among hepatitis B e antigen or antibody positive, and non-A, non-B patients with chronic active hepatitis and liver cirrhosis. Our findings suggest that diminished interferon-gamma production is associated with disease severity in chronic liver disease, irrespective of the hepatitis B virus carrier state. It would be interesting to compare the efficacy of treatment with interferon-gamma or interferon-gamma inducers such as interleukin 2 in chronic hepatitis B patients with and without decreased in vitro interferon-gamma production.

Acyclovir and herpesvirus infections. A review of the literature

Acyclovir (Zovirax) is a qualified success as an effective and nontoxic antiviral chemotherapeutic agent and at present is approved for the treatment of initial genital herpes and limited life-threatening cutaneous herpes simplex viral infections in the immunocompromised host. Its efficacy in Epstein-Barr, varicella-zoster, and cytomegalorvirus infections appears less promising. According to one controlled study, its efficacy in the treatment of herpes labialis (HSV-1) infections has been disappointing. The highly selective action of acyclovir against viral DNA polymerase and its inhibition of viral DNA chain elongation result in a low incidence of human (host cell) toxicity, as manifested by local irritation at injection sites and a modest incidence of adverse renal effects, which can be reduced by judicious drug use. Newer antiviral agents now under development hold substantial promise for the future of antiviral chemotherapy.

Carbocyclic arabinofuranosyladenine (cyclaradine): efficacy against genital herpes in guinea pigs

Carbocyclic arabinofuranosyladenine (cyclaradine), a novel nucleoside analog with such desired features as hydrolytic and enzymatic stability, adenosine deaminase resistance, and low systemic toxicity, inhibited the replication of herpes simplex virus types 1 and 2. The 5'-methoxyacetate prodrug form exhibited significant efficacy in the topical treatment of genital infections by herpes simplex virus type 2.

Rapid detection and identification of herpes simplex virus in cell culture by a direct immunoperoxidase staining procedure

Cell monolayers were inoculated with 169 fresh and 76 previously frozen clinical specimens and examined for the presence of herpes simplex virus (HSV) by noting the appearance of characteristic cytopathic effect (CPE) and by using direct immunoperoxidase (IP) stain for viral antigen. HSV was detected by IP staining in 40 of 169 (23.7%) monolayers and by CPE in 39 of 169 (23.1%) monolayers inoculated with fresh specimens. All 40 isolates were detected and confirmed by IP staining within 24 h. Although 39 of 40 isolates were detected by CPE, only 9 of 39 (23%) were positive within 24 h. CPE was observed at 2.7 days on the average, but 4 days were required before 90% of the cultures were positive and more than 5 days were required before all HSV isolates were recognized. Similar results were observed for frozen specimens. HSV was detected earlier with IP staining, which demonstrated more extensive infection of cell monolayers inoculated with titrated fresh culture isolates and clinical specimens than did CPE. IP staining reduces the amount of time required for detection and identification of HSV in culture, is readily adaptable for use in the clinical laboratory, and permanent stained preparations can be made.

[Efficacy and tolerability of acyclovir in immunosuppressed patients with herpes simplex, herpes zoster or cutaneomucous chicken-pox. Multicenter trial apropos of 50 cases]

A multicenter trial of Acyclovir was carried out in 50 immunodepressed patients. The dose used was 15 mg/kg/day for 5 days in herpes simplex and 30 mg/kg/day for 10 days in herpes zoster and chicken pox by three one-hourly intravenous infusion per day. Acyclovir had a clear cut effect in 42 cases, a partial effect in 1 case, no effect in 1 case, and its action could not be assessed in 6 cases. The cutaneous and mucous membrane lesions were stabilised after an average of two days' treatment, and regression was observed from the third day. Of the 21 cases of zoster, 15 were cured without sequellae and 5 with post-zoster pain. The treatment failed in one patient. Of the 21 cases of cutaneous and/or mucous membrane herpes simplex, 20 satisfactory and 1 partial result were obtained. The outcomes of the 2 cases of chicken pox were favourable. There were three relapses after the end of therapy (2 herpes simplex, 1 zoster) but their outcomes were favourable after a second course of Acyclovir. In 20 cases it was possible to maintain the immuno-suppressive therapy. General tolerance was satisfactory.

Additive effects of acyclovir and immune transfer in neonatal herpes simplex virus infection in mice

Acyclovir had a dose-dependent, mild, but significant, inhibitory effect on interferon-stimulated human antiviral natural killer cytotoxicity in vitro. In a murine model of neonatal herpes simplex virus infection, acyclovir significantly (P < 0.05) increased survival afforded by the injection of human interferon and human mononuclear leukocytes from 67.8 to 88.6%.

Treatment of herpes virus infections in immunocompromised patients with acyclovir by continuous intravenous infusion

Sixteen immunocompromised patients with herpes virus infections were treated for three to five days with continuously administered intravenous acyclovir. Patients received initial acyclovir infusions over 5 minutes in dosages ranging from 1.5 to 5.0 mg/kg followed by continuously infused acyclovir at 7.2, 14.4, 21.6, 28.8, 36.0, or 43.2 mg/kg per day. The mean serum plateau levels of acyclovir determined by radioimmunoassay ranged from 4.1 microM for the 7.2 mg/kg per day dosage to 36.6 microM for the 43.2 mg/kg per day dose. A mean of 75 percent of acyclovir administered was recovered in the urine of patients treated. Eleven of 13 patients with varicella-zoster virus (VZV) infections had no new vesicle formation after three days of acyclovir treatment and all patients ceased to have new vesicles after five days of therapy. For the nine patients from whom complete viral cultures were available, six ceased to shed virus at three days, and viral shedding ceased by five days in all patients treated with acyclovir. No clinical or laboratory adverse reactions were associated with acyclovir therapy. These data suggest that acyclovir given by continuous intravenous infusion may be useful in the treatment of herpes virus infections in immunocompromised patients.

Alpha interferon and acyclovir treatment of herpes simplex virus in lymphoid cell cultures

The T-lymphoblastoid cell line CEM, persistently infected with herpes simplex virus type 1, has been used to examine the antiviral efficacy of human alpha interferon and acyclovir, both alone and in combination. Acyclovir and interferon each produced dose-dependent decreases in virus titer at concentration ranges of 1 to 100 microM (approximately 0.225 to 22.5 micrograms/ml) and 10 to 10,000 U/Ml, respectively. Mean reductions in titer of 1.9 and 4.2 log10 PFU/ml were observed with 100 microM acyclovir and 10,000 U of interferon per ml, respectively, on day 10 of treatment. The combination of 100 microM acyclovir and 10,000 U of interferon per ml produced the most rapid fall in virus titer of all regimens examined and elimination of infections virus by day 7. Prolonged treatment (greater than 10 days) with acyclovir or alpha interferon was accompanied by a gradual return of virus titer to control levels despite the continuous presence of drug. Virus preparations isolated from such cultures were tested for antiviral agent sensitivity by a plaque reduction method. Acyclovir-exposed isolates were found to be acyclovir resistant, with 50% inhibitory doses of greater than 200 microM, and to be thymidine kinase deficient. Alpha interferon-exposed isolates were not interferon resistant. These results suggest that, in persistently herpes simplex virus-infected CEM cells: (i) combination treatment with 100 microM acyclovir and 10,000 U of alpha interferon per ml is more effective in reducing virus titer than either agent alone; (ii) prolonged exposure to drug may result in development of resistance by either the virus strain or the host cell system; and (iii) development of acyclovir resistance by herpes simplex virus in lymphoid cells is mediated by thymidine kinase.

Core (2'-5')oligoadenylate and the cordycepin analog: inhibitors of Epstein--Barr virus-induced transformation of human lymphocytes in the absence of interferon

The 3'-deoxyadenosine (cordycepin) analog of (2'-5')oligo(A) [(2'-5')oligoadenylate with a triphosphate at the 5' end], synthesized enzymatically from cordycepin 5'-triphosphate in lysed rabbit reticulocytes or L-cell extracts was (i) inhibitory to translation in lysed rabbit reticulocytes and (ii) metabolically stable in extracts of either L cells or C85-5C lymphoblasts. The 5' dephosphorylated (core) (2'-5')oligo(A) and the core cordycepin analog can replace human fibroblast interferon in preventing the transformation of human lymphocytes after infection with Epstein--Barr virus B95-8 (EBV) as determined by the decreased incorporation of [3H]thymidine into cellular DNA and the inhibition of morphological transformation of EBV-infected lymphocytes. Whereas the naturally occurring core (2'-5')oligo(A) was cytotoxic to uninfected lymphocytes and proliferating lymphoblasts, the core cordycepin analog was not. Human leukocyte interferon was more effective than human fibroblast interferon in the inhibition of EBV-induced transformation of human umbilical cord lymphocytes and adult peripheral blood lymphocytes.

Single-dose pharmacokinetics of acyclovir

The pharmacokinetics of intravenously administered acyclovir were studied in 10 patients with advanced malignancies. After doses of 0.5 and 1.0 mg/kg, the slow disposition half-life values (t1/2beta) ranged from 2.2 to 3.1 h for the 1-h infusions and from 1.8 to 3.7 h for the 6-h infusions. Plasma levels, measured by radioimmunoassay, reached a maximum at the end of the 1-h infusions and approached steady state at 3 to 4 h into the 6-h infusions. Mean peak plasma concentrations obtained at 0.5 and 1.0 mg/kg administered over 1 h were 3.03 and 5.99 microM, respectively. Mean peak levels for the 6-h infusions were 1.07 microM at 0.5 mg/kg and 2.58 microM at 1.0 mg/kg. The mean urinary elimination of acyclovir was 44.7% of the administered doses. No clinical or laboratory abnormalities were noted in the 10 patients studied.

Interferon: status in treatment of skin disease

Interferons, glycoproteins originally investigated as antiviral agents, are now known to be active as anticancer agents, immune system modulators, and growth control regulators. For these reasons, interferons have definite and documented relevance to dermatologists. In regard to viral diseases, therapeutic trials in humans have shown promising results in herpes simplex infections, vaccinia, laryngeal papillomas, and condyloma acuminatum, as well as in rabies and hepatitis B. Pilot studies with interferon treatment of melanoma have been so promising that the American Cancer Society has selected this area to receive additional research support. Also, the antiproliferative effects of interferons have potential application to proliferative diseases such as psoriasis.