5-Iodo-2-deoxyuridine administered into the lateral cerebral ventricle as a radiosensitizer in the treatment of disseminated glioma

A rat brain tumor model (Fischer 344 rats) with the clinical and pathological features of dissemination via the cerebrospinal fluid (CSF) pathways was used to demonstrate the efficacy of 5-iodo-2-deoxyuridine (IUDR) as a radiosensitizer when it is administered directly into the CSF. Stereotaxic implantation of 9L gliosarcoma cells (5 X 10(5) into the CSF of the lateral cerebral ventricle resulted in widespread dissemination and median survival of 18.5 and 20 days (range, 10-22) in two experiments. A continuous 7-day infusion of IUDR into the CSF starting on the day of tumor implantation did not provide any beneficial effect. Irradiation of the cranial spinal axis with 800 rad on days 4, 6, and 7 after implantation achieved an increase in survival time that was modest but statistically significant. However, the combination of IUDR infusion and radiotherapy resulted in marked improvement in survival time and a 10% cure rate (two of 20 rats). This is the first demonstration in vivo that IUDR administered into the CSF can be a potent radiosensitizer.

Combined effects of radiation and IUdR on experimental liver tumors and hepatocytes

IUdR, a thymidine analogue, increased the radiosensitivity of SCC VII tumor cells. A decrease in Dq value of cell survival curve was more prominent compared with that in D0 value. However, in experimental liver tumors made by transplanting SCC VII tumors, the decrease in D0 value was apparent. Proportion of IUdR incorporated tumor cells in the liver increased with an increase in number of IUdR injections, and reached 52% after five administrations of the drug at an interval of twelve hours. However, few hepatocytes incorporated IUdR. The response of hepatocytes to radiation was evaluated by micronucleus appearance frequency. To accelerate the appearance of micronucleus in hepatocytes, partial hepatectomy was performed immediately after irradiations. No differences in micronucleus frequency were observed between the treated and untreated with IUdR.

Iododeoxyuridine (IdUrd) incorporation into DNA of human hematopoietic cells, normal liver and hepatic metastases in man: as a radiosensitizer and as a marker for cell kinetic studies

Iododeoxyuridine (IdUrd) was administered as a continuous infusion for 14 days to patients with glioblastoma and sarcoma, and for 3 days to patients with metastatic colorectal carcinoma. In the first group, the maximum incorporation of IdUrd into DNA was determined, taking granulocytes as parameter. In the second group, selective incorporation into DNA of normal liver and hepatic metastases of colorectal cancer was investigated. The highest dose of 675 mg/sq.m./day for 14 days produced IdUrd plasma concentrations of 1.8 +/- 0.3 microM, and a substitution of dThd by IdUrd in the range of 7.1-11.7%. Coadministration of fluorodeoxyuridine did not show significant enhancement of IdUrd-incorporation in granulocytes. Three-day intravenous infusions of IdUrd 1000 mg/sq.m./day produced 1.7-4.5% IdUrd-incorporation in hepatic metastases. Three-day intraarterial infusions (hepatic artery) produced 3.8-10.5% dThd-replacement, whereas, in 9/10 patients this was less than 1% in normal liver. In tumor tissue there was a trend towards FdUrd-modulated enhancement of IdUrd-incorporation, although there was considerable scatter. Cell kinetic studies revealed that IdUrd-incorporation in monocytes and granulocytes was very similar. In lymphocytes, a much lower fraction incorporated IdUrd. Liver tumor contained a considerably higher fraction of IdUrd-labeled cells, compared with normal liver. Potential doubling times for the tumors were estimated to be 10 days.

[Primary herpetic gingivostomatitis in a group of children]

The study of acute herpetic gingivostomatitis (AHGS) has been a very interesting theme for those dealing with periodontal practice. The majority of the authors states the application of symptomatic treatment for such disease and there is a nearly universal criterium that its lesions can be maintained up to 14 days. We decided to star a searching in the up-to-date literature and we found some very serious studies where was stated, among other statements, the application of a specific chemotherapy using an analogous pyrimidine: iodoxuridine. Since then, we started the study of AHGS in 20 children with clinical diagnosis of such disease. In 10 children a symptomatic treatment was applied and in the rest topical applications of collyrium of 0.1% iodoxuridine, three times a day. Both groups were appointed after three, seven and ten days of being under treatment in order to verify the evolution of symptoms (pain) and signs vesicles or ulcer). It was observed that either lesions or pain disappeared in a shortly time in those children treated with iodoxuridine, without side effects. It is concluded that the use of this drug was effective for our patients and, therefore, we suggest its study and application.

Management of varicella zoster infections in immunocompetent hosts

Varicella in otherwise healthy children usually requires no antiviral treatment. In severe cases, however, such as are seen in neonates and adults, treatment must be given. Anecdotal evidence suggests the efficacy of intravenous acyclovir in such patients. Herpes zoster in immunocompetent patients may be severe enough to warrant antiviral therapy, particularly in elderly patients. Both idoxuridine and acyclovir have been investigated in placebo-controlled double-blind studies. Due to its low toxicity, ease of administration, and the possibility of systemic administration, acyclovir has largely replaced older antivirals in the management of herpes zoster in the normal host. Recent studies have shown the efficacy of oral acyclovir. In addition, oral acyclovir may prevent the ocular complications of ophthalmic zoster. When acyclovir is given, it should be administered as early as possible, preferably no later than four days after the onset of the rash. The combination of acyclovir and prednisolone for the prevention of post-herpetic neuralgia has not proved effective.

Management of non-genital herpes simplex virus infections in immunocompetent patients

Non-genital herpes simplex virus in immunocompetent hosts causes a variety of primary infections--gingivostomatitis, keratoconjunctivitis, herpetic whitlow, and encephalomyelitis. Recurrent infections with orolabialis are very common, but are usually mild and self-limiting. Cutaneous complications of herpes simplex virus infections include eczema herpeticum and erytherma multiforme. Systemic treatment with acyclovir is indicated in encephalomyelitis, progressive eczema herpeticum, and frequent severe erythema multiforme. Chronic, suppressive acyclovir treatment may be helpful in severe recurrent infections or those complicated by erythema multiforme/dissemination. Many primary and recurrent infections can be treated with simple topical therapy to control secondary infection. There is no evidence that systemic treatment affects viral latency or recurrent infections following discontinuation of treatment.

Herpes simplex virus infection of the hand. Clinical features and management

Herpes simplex virus (HSV) infection of the hand occurs predominantly in three different population groups. Young adults with a recurrent HSV II infection of the hand account for the majority of cases. A prodromal phase of up to 72 hours and a recurrence of seven to 10 days' duration occasionally associated with lymphangitis, lymphadenopathy, and lymphedema are characteristic. HSV I infection of the hand classically occurs in children with herpetic stomatitis and in health care workers infected during patient care delivery. In health care workers, the infection may last 21 to 28 days and be associated with severe pain and lymphangitis. Recurrences appear uncommon in HSV I infections. Primary infection is usually managed conservatively. Vesicle drainage for pain relief and antiviral therapy with acyclovir may be of value. For recurrent infections, acyclovir, 800 mg orally, twice daily, initiated during the prodrome in an open study of eight patients appeared effective in aborting the attack. Evaluation of long-term suppression in recurrent HSV infection of the hand is in progress.

A retrospective analysis of forty-six cases of herpes simplex encephalitis seen in Glasgow between 1962 and 1985

The clinical features, investigative profiles and outcome of 46 patients with biopsy or autopsy-proven herpes simplex encephalitis admitted to the Institute of Neurological Sciences, Glasgow between 1962 and 1985 were analysed retrospectively. The protean presenting symptoms and signs included a history of a prodromal influenza-like illness (48 per cent), rapid onset of headache, clouding of consciousness and confusion (52 per cent), meningism (65 per cent), raised intracranial pressure (33 per cent), deep coma (35 per cent), mutism or aphasia (46 per cent), focal neurological signs (89 per cent), and seizures (61 per cent). When seizures occurred they were almost always focal. The electroencephalogram was the most useful diagnostic test being abnormal in all cases, the majority showing focal changes in one or other hemisphere. Of the neuroradiological procedures employed, computerized tomographic and isotope brain scanning most frequently demonstrated localizing abnormalities in one or both temporal and/or frontal lobes. Midline shift was seen in half the cases. The cerebrospinal fluid was abnormal in every case but was not diagnostic. Cerebral biopsy of one temporal lobe was performed in 40 cases and a positive diagnosis of acute necrotizing encephalitis was made in 37 of these. Herpes simplex virus was isolated from the brains of 29 of the 40 cases in which the procedure was attempted, but immunofluorescence assays for antigens to herpes simplex virus were only positive in 11 out of 25 cases. Serological assays showed a greater than four-fold rise in the anti-herpes simplex virus antibody titre in 13 out of 22 patients tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacology and phase I/II study of continuous intravenous infusions of iododeoxyuridine and hyperfractionated radiotherapy in patients with glioblastoma multiforme

Forty-seven adult patients with glioblastoma multiforme (GBM) were treated in a phase I/II study combining continuous intravenous (IV) infusions of iododeoxyuridine (IdUrd) and hyperfractionated radiation therapy. IdUrd was administered as a continuous infusion (24 h/d) for two separate 14-day infusion periods. The dose of IdUrd was escalated from 500 to 1,200 mg/m2/d. The initial wide-field tumor volume was treated to 45 Gy at 1.5 Gy fractions twice daily over 3 weeks. Following a planned 2-week break, a reduced-field boost of 25 Gy was delivered using 1.25 Gy fractions twice daily over 2 weeks (total dose, 70 Gy over 9 weeks). The IdUrd infusion preceded both the wide-field and reduced-field irradiation by 1 week. All treatment was performed on an outpatient basis. Dose-limiting systemic toxicity to the bone marrow (primarily thrombocytopenia) and gastrointestinal (GI) tract (both stomatitis and diarrhea) established the maximum tolerable dose (MTD) at 1,000 mg/m2/d for a 14-day infusion. Significant local toxicity (within the radiation field) was not seen. The kinetics of IdUrd were linear with dose escalation and reached steady-state plasma concentrations of 1.3 to 3.4 mumol/L. The total body clearance of IdUrd was .82 L/min/m2. The primary metabolite, 5-iodouracil (IUra) approached steady state by day 6 of the infusion when plasma levels were 60 times higher than IdUrd. Plasma levels of uracil and thymine, but not thymidine, were elevated throughout the infusion. With a minimum follow-up of 1 year, ten patients remain alive, while 33 patients died of progressive disease, and four patients died of other causes (including one treatment-related death). The median survival for all 47 patient and for the 40 patients receiving the MTD was 45 and 47 weeks, respectively, with 12% and 14% survivals at 24 months. Using a Cox regression analysis, age (less than or equal to 50 years v greater than 50 years) and pretreatment performance status (PS) (Eastern Cooperative Oncology Group [ECOG]-PS 0 to 1 v PS 2 to 3) were independent, statistically significant (P2 less than .05) predictors of survival, with the ECOG status being a better predictor. Patients with a PS 0 to 1 (28 patients) had a median survival of 64 weeks with 21% survival at 24 months, compared with a median survival of 29 weeks and 0% survival at 12 months in the 19 patients with PS 2 to 3. The overall and subgroup survival data are at least comparable to other combined modality treatment approaches in patients with GBM.

Antiviral agents

Amantadine is well established as the preferred antiviral agent for the prophylaxis of influenza A and may also be beneficial therapeutically when used early in the course of the disease. Idoxuridine is applicable only in the treatment of herpetic keratitis. Currently, acyclovir is the most effective agent for the treatment of herpes simplex and varicella-zoster virus infections. Ribavirin has recently been released for use in aerosol form for severe respiratory syncytial virus infections that occur in infants and young children. Vidarabine, which previously was the drug of choice in the treatment of severe herpetic infections, has now been replaced by the more effective acyclovir. Ganciclovir, an experimental agent, has shown promise against cytomegalovirus infections in patients who have undergone kidney or liver transplantation, but its effects are only temporary in patients who have undergone bone marrow transplantation and patients with acquired immunodeficiency syndrome (AIDS) who have cytomegalovirus infections.

Treatment of herpes simplex virus infections

Herpes simplex virus infections cause considerable morbidity in immunocompromised and immunocompetent individuals. The development of immunomodulatory agents and nucleoside analog drugs has been responsible for important advances in the treatment of HSV infections. Acyclovir, an acyclic guanosine derivative, has played a major role in the treatment and suppression of HSV episodes in immunocompromised and immunocompetent patients.

Measurement of the stratum corneum drug reservoir to predict the therapeutic efficacy of topical iododeoxyuridine for herpes simplex virus infection

A rapid, in vivo measurement of the penetration of antiviral compounds into the skin would improve our ability to predict the therapeutic efficacy of topical treatments for herpes simplex virus (HSV) infection. We have studied the concentration of iododeoxyuridine (IDU) in the stratum corneum of guinea pig skin by tape stripping at different time points after single and multiple topical doses of the drug. These results were correlated with the efficacy of topical IDU against an experimental cutaneous HSV infection. Ten adhesive tape strippings were performed on depilated guinea pig dorsum in vivo at serial intervals after a single topical dose of [3H]IDU. Iododeoxyuridine levels in the stratum corneum peaked at 1-3 h (67-70 mg/g of tissue) and then gradually declined over the next 3-24 h. We hypothesized that the peak IDU stratum corneum concentration would correlate with therapeutic efficacy. Accordingly, we determined the quantity of IDU in guinea pig stratum corneum 2 h after a topical application of seven different concentrations of IDU in dimethylsulfoxide (DMSO) and examined the in vivo efficacy of these formulations in an experimental dorsal cutaneous HSV-1 infection in guinea pigs. The results showed an excellent correlation between the quantity of IDU in the stratum corneum and reduction in lesion severity (r = 0.95-0.97). Fifteen percent IDU in DMSO provided the highest therapeutic efficacy (90-94%). We also studied the relationship between the clinical efficacy of different dosing frequencies and the amount of IDU in the stratum corneum. Serial IDU stratum corneum concentrations were measured over 24 h following 1, 2, 3, or 4 applications per day of 1, 3, and 15% IDU in DMSO treatments and parallel efficacy studies of the different regimens were conducted in the animal model. Within each dosing frequency, the cumulative amount of drug in the stratum corneum correlated with the strength of the test formulation and with efficacy in the animal model. For each of the three formulations, increasing the number of daily doses from one up to three led to progressive increases in cumulative stratum corneum IDU levels and clinical efficacy. An increase in the number of daily applications to four had little effect on drug efficacy and was associated with a plateau in stratum corneum IDU levels. Stratum corneum IDU concentrations were rapid and easy to determine and correlated well with clinical events.(ABSTRACT TRUNCATED AT 400 WORDS)

Halogenated pyrimidines as radiosensitizers in the treatment of glioblastoma multiforme

Sixty patients with high-grade gliomas (including 50 patients with glioblastoma multiforme) were entered on four sequential Phase I trials combining continuous intravenous infusions of halogenated pyrimidines and high-dose brain irradiation. Patients received two 14-day infusions of bromodeoxyuridine (BUdR) or iododeoxyuridine (IUdR) during the initial wide field and later reduced field radiation treatment (total radiation dose 65-70 Gy). All patients were followed a minimum of 6 months or until death. The actuarial median survival was 13 months for the entire group, with an 18-month survival of 24%. No significant survival differences were observed based on BUdR versus IUdR, 12-h versus 24-h infusion schedule, degree of surgical resection, or sex. Good performance status and age under 50 years were significant favorable prognostic factors. Of interest, the 48 patients who completed planned treatment had a 14-month median survival, with a 30% 18-month survival. These survival observations are at least comparable to other combined modality trials in patients with glioblastoma multiforme. Ongoing and planned clinical trials using the halogenated pyrimidine analogs as radiosensitizers in patients with glioblastoma multiforme are discussed.

Therapy of ocular herpes simplex infections

Herpes simplex viral infection is a common cause of infection involving the eye and skin adjacent to the eye. Acute keratoconjunctivitis is a frequently observed herpetic manifestation often accompanied or exacerbated by stress factors, including fever (especially when associated with respiratory or intestinal infection), stress, trauma, environmental exposure, drugs, and menstruation. Each year approximately 300,000 to 500,000 cases of corneal herpes are reported. Complications such as decreased or lost vision may be associated with attacks of ophthalmic herpes infections. Therefore, effective treatment is imperative.1 Experts estimate that nearly 25% of patients with a primary ocular infection will have a recurrence of the infection, and approximately 50% of these patients will have a recurrence within two years. Herpes viral infections are a significant cause of blindness and a primary indication for corneal transplants.

Glycyrrhizin gel as a vehicle for idoxuridine--I. Clinical investigations

The therapeutic efficacy of a new formulation that incorporates 0.2% IDU in glycyrrhizin gel has been tested on patients who suffer from herpes of the lips and nose. The preparation was significantly more effective than a commercial 0.5% IDU ointment. It reduced the healing time and produced an almost instantaneous relief from pain. The higher efficacy of the new preparation may be ascribed to the reported anti-inflammatory and antiviral activities of glycyrrhizin together with an enhanced permeation of the IDU through the skin.

A trial of topical idoxuridine for vulvar condyloma acuminatum

The effect of 0.25% idoxuridine ointment on condyloma acuminatum of the vulva was investigated in a randomized, double-blind, placebo-controlled trial in 24 women. Idoxuridine inhibits DNA synthesis in mammalian cells and is a specific inhibitor of DNA viruses. Of the 24 women with vulvar condyloma acuminatum, 14 applied idoxuridine ointment and 10 a placebo ointment to the lesions twice daily for 2 weeks. In 11 out of 14 patients treated with idoxuridine the condylomata regressed completely. The treatment did not cause any side-effects. None of the women in the placebo group showed regression of the condylomata. Topical idoxuridine therapy is effective and non-toxic; it appears to be most effective for new condylomata.

Herpes simplex keratitis and amblyopia

Herpes simplex keratitis can cause severe loss of vision in children. The findings in five children show that amblyopia is caused by stimulus deprivation and/or anisometropia. Early medical treatment, occlusion therapy, and frequent refractions are crucial for a good visual prognosis.

Laser therapy of conjunctival papillomas

Carbon dioxide (CO2) laser therapy was successfully used in the treatment of recurrent conjunctival papillomas in a 40-year-old man. Surgical excision, cryotherapy and immunotherapy with transfer factor and dinitrochlorobenzene had all been unsuccessful in eradicating the lesions. CO2 laser therapy should be considered as an alternative treatment for conjunctival papillomas refractory to other forms of therapy.

Herpetic keratitis therapy to reduce recurrence

Since the herpes simplex virus locates latently in the ganglia and is reactivated by certain triggers, the important problem in treatment is to prevent or reduce recurrence. The present study investigates the role of mechanical debridement in lessening the recurrence of dendritic keratitis in patients with herpetic epithelial keratitis. Group A was treated with mechanical debridement plus IDU, Group B with IDU alone. Also studied was the effect of steroid subconjunctival injection on herpetic recurrence in patients with herpetic stromal keratitis: Group C was treated with intravenous infusion of pepsin-treated gamma-globulin (PTGG) and steroid subconjunctival injection, Group D with steroid subconjunctival injection alone and Group E with intravenous infusion of PTGG alone. The recurrence rates of dendritic keratitis were 19% in Group A and 40% in Group B (average follow-up periods: 24 and 25 months). The recurrence rates of stromal keratitis were 61% in Group C, 64% in Group D, and 36% in Group E (average follow-up periods: 20, 19 and 15 months). The difference between Groups D and E was statistically significant (chi 2 test, P less than 0.05). The recurrence rates of dendritic keratitis were 18% in Group C, 21% in Group D and 7% in Group E. In conclusion, mechanical debridement tended to reduce the recurrence of herpetic epithelial keratitis and steroid subconjunctival injection to increase the recurrence of epithelial or stromal keratitis.

HSV1 strain sensitivity in experimental rabbit keratitis: evolution under repeated topical IDU administrations

The effects of repeated topical idoxuridine (IDU) administration of HSV1 strain sensitivity were investigated during 6 serial passages (P1 to P6) in the rabbit. By comparison to placebo treated rabbits, a delay in ulcer cicatrization appeared at P2 and clinical resistance was completed at P3. Clinical cross resistance to acyclovir (ACV) was also tested and demonstrated at P7. In vitro, a plaque reduction test on Vero cells using directly the tear film HSV populations allowed the prediction of the resistance by an early rise in the effective dose 90% (ED 90) value anticipating that in ED 50%. An ED 50 determination by dye-uptake assay on P6 HSV isolate demonstrated a cross resistance to viral thymidine kinase (TK) dependent drugs without any change in Ara-A and PFA sensitivity, according to a 23% TK activity at P6. At the last passage the HSV drug resistant population had an unrestricted corneal pathogenicity. A return to IDU and ACV in vitro sensitivity was demonstrated in group control animals at P2 but not at P4 or P6.