Oral Antifungal Agents Research Articles

Tinea capitis in adult women masquerading as bacterial pyoderma

Tinea capitis is generally thought to be a common disease in children but not in adults. Adults with tinea capitis generally present with scale and alopecia. We report 3 adults with inflammatory tinea capitis caused by Trichophyton tonsurans that resembled a bacterial infection. Of these patients, 2 were initially given a diagnosis of bacterial pyoderma. All patients were successfully treated with oral antifungal agents. One patient had significant eosinophilia that resolved with treatment. We conclude that tinea capitis should remain in the differential diagnosis of adults with alopecia and pyoderma-like presentations. A biopsy specimen was helpful in making the diagnosis in 2 of the 3 patients, but fungal culture confirmed the diagnosis in all cases.

Onychomycosis: quality of studies.

The quality of original clinical trial publications pertaining to the use of oral antifungal agents to treat onychomycosis was evaluated using predetermined criteria. The list of studies included in this analysis was determined by conducting a search in Medline. For each clinical trial, two independent reviewers each determined a composite score by evaluating a list of criteria that were felt to represent a good study, for example, randomization and blinding, prior sample size calculated, and treatment regimen clearly explained. A citation count was performed to determine whether higher-quality papers were cited more often than lower-quality papers. Forty-five studies were included in this quality analysis of study design. Of these, 27 were considered to be "high quality" (score greater than or equal to 11 out of 20). A significant correlation coefficient of 0.997 was found between the two reviewers (P < 0.00001). Higher-quality papers were cited significantly more often than lower-quality papers (P = 0.03). The scale that we use to evaluate the quality of onychomycosis studies has high interrater reliability. According to this scale, many published studies (18 out of 45) pertaining to treatments for onychomycosis do not meet the criteria required to be considered "high quality."

In vitro and in vivo studies of the anticancer action of terbinafine in human cancer cell lines: G0/G1 p53-associated cell cycle arrest.

Terbinafine (TB) (Lamisil), a promising oral antifungal agent used worldwide, has been used in the treatment of superficial mycosis. In our study, we demonstrated that TB dose-dependently decreased cell number in various cultured human malignant cells. Flow cytometry analysis revealed that TB interrupts the cell cycle at the G0/G1 transition. The TB-induced cell cycle arrest in colon cancer cell line (COLO 205) occurred when the cyclin-dependent kinase (cdk) system was inhibited just as the levels of p53, p21/Cip1 and p27/Kip1 proteins were augmented. In the TB-treated COLO 205, the binding between p53 protein and p53 consensus binding site in p21/Cip1 promoter DNA probe was increased. Pretreatment of COLO 205 with p53-specific antisense oligodeoxynucleotide decreased the TB-induced elevations of p53 and p21/Cip1 proteins, which in turn led to arrest in the cell cycle at the G0/G1 phase. Moreover, in the p53 null cells, HL60, TB treatment did not induce cell cycle arrest. Taken together, these results suggest an involvement of the p53-associated signaling pathway in the TB-induced antiproliferation in COLO 205. We further examined whether administration of TB could affect the growth of tumors derived from human colon cancer cells in an in vivo setting. COLO 205 cells implanted subcutaneously in nude mice formed solid tumor; subsequent intraperitoneal injections of TB (50 mg/kg) led to obvious decline in tumor size, up to 50-60%. In these tumors, increases in the p21/Cip1, p27/Kip1 and p53 proteins and the occurrence of apoptosis were observed. Combined treatment with TB and nocodazole (ND), a clinically used anticancer agent, potentiated the apoptotic effect in COLO 205. These findings demonstrate for the first time that TB can inhibit the proliferation of tumor cells in vitro and in vivo.

Dermatophyte test medium culture for evaluating toenail infections in patients with diabetes.

To evaluate the performance of the in-office dermatophyte test medium (DTM) culture when used to confirm the diagnosis of onychomycosis in diabetic patients. Nail samples from 184 diabetic patients who exhibited symptoms consistent with toenail onychomycosis were screened for dermatophyte fungal infection using DTM, potassium hydroxide evaluation, and central mycology laboratory culture tests. The diabetic patient group investigated in this study is a subset of a heterogeneous set of patients who participated in a nationwide survey designed to investigate the use of fungal culture tests by dermatologists, podiatrists, and primary care physicians described in detail elsewhere. The overall sensitivity of the DTM and central laboratory culture methods was estimated and compared. Sensitivity differences between DTM and central laboratory culture methods were tested for statistical significance using the McNemar statistic. DTM culture was positive in 102 of 184 patients (55%), while the central laboratory culture test detected the existence of fungal infection in 78 of 184 (42%). The two tests were in agreement (both positive or both negative) in 114 of 184 patients (62%). Central laboratory culture identified dermatophytes as the pathogen in 91% of positive cases. DTM is a convenient and inexpensive culture test that can be used to confirm dermatophyte infections in diabetic patients with presumed onychomycosis. We found this test to be well suited for use in the primary care setting. Because oral antifungal agents are effective against dermatophyte species, which cause the vast majority of nail infections, diagnosis of onychomycosis requires confirmation of dermatophyte infection only, not identification of genus and species. DTM fulfills this requirement and has a diagnostic yield comparable to central laboratory culture.

Treatment of onychomycosis in the diabetic patient population

Onychomycosis is a common medical condition in patients with diabetes. Conflicting data exist as to whether diabetes predisposes patients to the disease. Controversy notwithstanding, patients with diabetes have several medical conditions (obesity, peripheral neuropathy, and retinopathy) that can inhibit the identification or mask the progression of fungal nail infections. In addition, vascular insufficiency, impaired wound healing, and compromised immunologic status associated with diabetic foot increase the risk of secondary infections in diabetic patients with onychomycosis. Such factors contribute to an increased morbidity and decreased quality of life in these patients and underscore the need for effective antifungal treatment. Oral antifungal agents are generally well tolerated, but serious adverse events independent of or associated with a number of significant drug interactions have been reported. The availability of a topical therapy, ciclopirox topical solution, 8% (Penlac Nail Lacquer), provides clinicians with an additional effective and well-tolerated treatment option. In order to further increase the efficacy of topical or oral treatment, mechanical intervention (e.g., debridement) may be combined with either of these options. Choice of appropriate treatment and careful monitoring of fungal nail infections can prevent significant morbidity in patients with diabetes.

Persistent and Recurrent Tinea Corporis in Children Treated With Combination Antifungal/ Corticosteroid Agents

Combination antifungal/corticosteroid preparations are widely used by nondermatologists in the treatment of superficial fungal infections in patients of all ages. Over half of the prescriptions written for the most commonly used combination agent clotrimazole 1%/betamethasone diproprionate 0.05% cream (Lotrisone, Schering, Kenilworth, NJ) were prescribed for children younger than 4 years old. Our pediatric dermatology division has recently encountered a series of children with recurrent or persistent tinea corporis, especially tinea faciei, treated initially with combination antifungal/corticosteroid cream. All children evaluated for tinea corporis in a university hospital pediatric dermatology clinic from January through June 2001 were identified from the clinic registry for a retrospective chart review. Response to therapy was confirmed by telephone survey and/or follow-up visits at least 1 month after clearing of infection. Six children ranging in age from 4 to 11 years were evaluated for tinea corporis in a pediatric dermatology clinic at our institution during the 6-month period. All 6 children were diagnosed clinically by their pediatrician with tinea corporis and initially treated with clotrimazole 1%/betamethasone diproprionate 0.05% cream for 2 to 12 months. In our pediatric dermatology clinic, patients had their diagnosis confirmed with a positive potassium hydroxide preparation and were treated with one of several oral or topical antifungal agents with clearing of all tinea infections. The use of combination clotrimazole 1% cream/betamethasone diproprionate 0.05% cream (Lotrisone) for the treatment of tinea corporis may be associated with persistent/recurrent infection.

Intractable Oral Candidosis As An Indicator Of HIV Infection In Infants

Objective: Human immunodeficiency virus infection is assuming an epidemic proportion in the developing world, and infants are increasingly being infected and seen with clinical features and serological evidence of HIV infection in IIorin. Intractable oral candidosis is one of the clinical features of the disease seen commonly infants. This study examined the possible association between intractable oral thrush and HIV infections in infancy Design: This is a prospective study carried out over a 3 year period. Subjects & Method: Infants presenting with oral candidosis who did not respond to two courses of oral mycostatin drop given thrice daily over 2 weeks period were studied. Such infects were screened for HIV infection after parental consent. Another group of infants who did not have oral candidosis but were screened for HIV infection due to other indication served as controls for the purpose of comparison. Results: Thirty two infants with intractable oral candidosis were screened and 28 (87.5%) were HIV positive whilst 2 out of 20 (10%) cases without intractable oral candidosis screened other reasons were positive for HIV infection (X 2 = 21.48, p=0.000036, odds ratio = 24.54 “RR” = 5.42). The presence of intractable oral cadidosis in HIV infected infants has a sensitivity of 93.3% and specificity of 81.8%, with a positive predictive vale of 85.3%. The oral lesions cleared completely with oral miconazole gel given thrice daily for two weeks Conclusion: The finding of extensive intractable oral candidosis which is refractory to simple oral antifungal agent therapy in infants should raise the suspicion of HIV infection and such infants should be screened for HIV after parental consent KEY WORDS: Intractable oral thrush, infants, HIV infection, miconazole gel Nigerian Journal of Clinical Practice Vol.6(1) 2003: 42-45

Use of gene networks from full genome microarray libraries to identify functionally relevant drug-affected genes and gene regulation cascades.

We developed an extensive yeast gene expression library consisting of full-genome cDNA array data for over 500 yeast strains, each with a single-gene disruption. Using this data, combined with dose and time course expression experiments with the oral antifungal agent griseofulvin, whose exact molecular targets were previously unknown, we used Boolean and Bayesian network discovery techniques to determine the gene expression regulatory cascades affected directly by this drug. Using this method we identified CIK1 as an important affected target gene related to the functional phenotype induced by griseofulvin. Cellular functional analysis of griseofulvin showed similar tubulin-specific morphological effects on mitotic spindle formation to those of the drug, in agreement with the known function of CIK1p. Further, using the nonparametric, nonlinear Bayesian gene networks we were able to identify alternative ligand-dependant transcription factors and G protein homologues upstream of CIK1 that regulate CIK1 expression and might therefore serve as alternative molecular targets to induce the same molecular response as griseofulvin.

Disseminated Histoplasmosis Complicated by Small-Bowel Perforation in a Patient With Acquired Immune Deficiency Syndrome

Disseminated Histoplasmosis Complicated by Small-Bowel Perforation in a Patient With Acquired Immune Deficiency Syndrome

Ketoconazole potentiates the antitumor effects of nocodazole: In vivo therapy for human tumor xenografts in nude mice.

Our previous studies demonstrated that the oral antifungal agent ketoconazole (KT) induces apoptosis and G0/G1 phase cell cycle arrest in human cancer cell lines. In this study, we first demonstrated that KT (1 microM) potentiated the apoptotic effects of nocodazole (ND, 1 nM) in COLO 205 cancer cells. We further demonstrated the therapeutic efficacy of a combined treatment of KT (50 mg/kg/three times per week) and ND (5 mg/kg/three times per week) in vivo by treating athymic mice bearing COLO 205 tumor xenografts. The antitumor effects of ND were significantly potentiated by KT in mice after 6 wk of treatment. No gross signs of toxicity were observed in mice receiving these treatment regimens. The apoptotic cells were detected in a microscopic view of the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining and by observation of DNA fragmentation in KT + ND-treated tumor tissues. The levels of cell cycle regulatory proteins were determined by Western blot analysis. Treatment with KT inhibits tumor growth through elevation of p53, p21/CIP1, and p27/KIP1 as well as inhibition of cyclin D3 and cyclin-dependent kinase 4 protein expression. Immunohistochemical staining analysis showed that p53, p21/CIP1, and p27/KIP1 immunoreactivity were induced in the tumor tissues. To clarify the roles of the p21/CIP1 and p27/KIP1 protein expression involved in G(0)/G(1) arrest and/or apoptosis induced by a combined treatment with KT and ND, antisense oligodeoxynucleotides (ODNs) specific to p21/CIP1 and p27/KIP1 were used. Our results demonstrated that apoptotic phenomena, including BAX induction and cytochrome C released from mitochondria induced by KT + ND, were significantly attenuated by pretreatment the cells with the p27/KIP1-specific antisense ODNs. These results indicate that p27/KIP1 protein does indeed play a critical role in the KT + ND-induced apoptosis. Our study revealed the molecular mechanism of KT + ND in regression of the tumor growth. The apoptotic effects of KT in a great variety of cancer cells make it a very attractive agent for cancer chemotherapy.

Oxiranyl anion-mediated synthesis of highly enantiomerically enriched styrene oxide derivatives.

[reaction: see text] The stereospecific alpha-lithiation of optically active styrene oxides and the trapping reaction of the corresponding highly reactive intermediates with electrophiles to produce optically active styrene oxide derivatives are described. This methodology has been applied to the synthesis of an optically active oral antifungal agent of industrial interest.

Overanticoagulation associated with combined use of antifungal agents and coumarin anticoagulants.

Several case reports have associated combined use of coumarins and antifungal agents with overanticoagulation. However, we are not aware of epidemiologic studies that quantify the risk of overanticoagulation caused by antifungal agents. We conducted a follow-up study in a large population-based cohort to investigate the antifungal agents that are associated with overanticoagulation during therapy with coumarins. All patients in the Rotterdam Study who were treated with acenocoumarol or phenprocoumon in the study period from April 1, 1991, through Dec 31, 1998, and for whom international normalized ratio data were available were followed up until an INR > or =6.0, the end of their treatment, death, or the end of the study period. Proportional hazards regression analysis was used to estimate the risk of an INR > or =6.0 in relation to concomitant use of an oral anticoagulant and antifungal agents, after adjustment for several potentially confounding factors such as age, gender, hepatic dysfunction, malignancies, and heart failure. Of the 1124 patients in the cohort, 351 had an INR > or =6.0. The incidence rate was 6.9 per 10,000 treatment days. Oral miconazole most strongly increased the risk of overanticoagulation with an adjusted relative risk of 36.6 (95% confidence interval [CI], 12.4-108.0). In this study among outpatients of an anticoagulant clinic who were on a regimen of coumarins, oral miconazole was especially strongly associated with overanticoagulation. Awareness of these drug interactions and more frequent monitoring of INR values during the initial stages of treatment with some antifungal drugs in patients taking coumarins may minimize the risk of bleeding complications. The concurrent use of miconazole and coumarins should be discouraged.

New millennium, new nail problems

The major nail disorders in the new millennium may well be related to systemic drugs used for conditions other than nail problems. Conversely the new therapies for onychomycosis, a condition whose incidence is increasing, may result in drug interactions. We have chosen to report on the most common iatrogenic causes of nail disorders, such as toxic epidermal necrolysis, psoriasis or acral psoriasiform reaction, lichen planus or lichenoid reaction, antineoplastic therapy-induced palmar-plantar erythrodysesthesia, paronychia and pyogenic granuloma, drug-induced onycholysis and photo-onycholysis, and drug-induced scleroderma and sclerodermiform conditions. The adverse effects and drug interactions of the newer oral antifungal agents will be quoted and their management will be discussed.

Tinea Capitis in Infants

Source: Romano C, Gianni C, Papini M. Tinea capitis in infants less than 1 year of age. Pediatr Dermatol. 2001;18: 465–468.These investigators, representing 3 university medical centers in Italy, report on 15 cases of tinea capitis observed in infants less than 1 year of age. There were 10 boys and 5 girls ranging in age from 45 days-12 months (mean age 6 months). Twelve patients presented with scaling patches of hair loss and 3 with a kerion. The diagnosis of tinea capitis was confirmed by potassium hydroxide preparation and culture. Nine patients were infected with Microsporum canis, 3 with Trichophyton mentagrophytes, and 1 each with T tonsurans, T violaceum, and T erinacei. Thirteen patients were treated successfully with a topical imidazole and griseofulvin (10 mg/kg/d of an ultramicrosize preparation or 15 mg/kg/d of a microsize preparation for 30 to 60 days), and 2 were successfully treated with terbinafine (52.5 mg/d for 3 to 4 weeks). The authors conclude that although uncommon in infants less than 1 year of age, tinea capitis should be suspected in those with hair loss, scaling, or signs of scalp inflammation.Although it has been reported as early as 6 days of life, tinea capitis occurs infrequently in infants.1 In the United States, more than 90% of infections are due to T tonsurans and most others are caused by M canis. T tonsurans is transmitted by direct contact with an infected individual, by fallen hairs or by fomites (eg, hats, combs or brushes), while M canis is a zoonosis acquired from infected dogs or cats.1,2 The family pet may, in fact, not be recognized as the source of the dermatomycosis. Felines in particular may have no apparent lesions.3 In infants and older children, T tonsurans infection may produce 1 or more scaling patches of alopecia with “black dot” hairs (the remnants of hairs that have broken at the scalp surface), diffuse scale with subtle hair loss (the seborrheic form), or inflammation (scattered pustules or a boggy, tender mass known as a kerion). Infection with M canis causes scaling patches of alopecia within which hairs are broken several millimeters above the scalp surface, or a kerion. As noted by the authors of this report, once tinea capitis has been diagnosed in an infant, the most appropriate initial therapy is oral griseofulvin. In the United States, treatment generally requires a dose of 15–20 mg/kg/d of the microsize preparation (given as a single or divided dose) administered for 6–8 weeks. Only 1 liquid form of griseofulvin exists; it contains 125 mg of the microsize preparation per 5 ml. Although other oral antifungal agents (eg, fluconazole, terbinafine, and itraconazole) would likely be effective, experience with their use in infants is limited. Laboratory monitoring may be required, and logistical and safety concerns exist (eg, terbinafine is not available in a liquid form and there is concern about the safety of itraconazole suspension4). (See also AAP Grand Rounds, May 2001;5:49.)

Hepatic Safety of Itraconazole

Background: As the use of the newer oral antifungal agents for the treatment of superficial fungal infections becomes more widespread, the issue of safety surrounding their use is becoming an increasingly important consideration. Itraconazole is effective and well tolerated, with most side effects being minor and reversible. The most common adverse events are gastrointestinal upset, headache, and transient skin reaction. There have also been rare reports of hepatitis. Objective: To assess the hepatic safety of pulse and continuous itraconazole in the treatment of onychomycosis. Methods: An analysis was performed on all itraconazole clinical trials sponsored by Janssen Research Foundation in the treatment of onychomycosis, where there was an assessment of laboratory safety. A review of the published literature was also undertaken to assess the hepatic safety of itraconazole in common practice. Results: The data indicate that itraconazole pulse treatment is safe, with no significant differences in the number of code 4 abnormalities (baseline value is in the normal range and at least two values, or the last testing in the observation period, exceed twice the upper limit of normal) in the liver function parameters studied: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, and total bilirubin. The incidence of all the code 4 abnormalities was below 2%. In the literature there are reports of symptomatic hepatitis with itraconazole continuous therapy but no published report of symptomatic hepatotoxicity using the pulse regimen. Conclusions: Itraconazole pulse therapy for onychomycosis appears to be safe, especially from the perspective of potential liver damage. In the itraconazole package insert liver function tests are recommended for patients receiving continuous itraconazole for periods of time exceeding 1 month. There is no such monitoring requirement for the pulse regimen unless the patient has a history of underlying hepatic disease, the liver function tests are abnormal at baseline, or at any time that there is the development of signs or symptoms suggestive of liver dysfunction.

Hepatic safety of itraconazole.

As the use of the newer oral antifungal agents for the treatment of superficial fungal infections becomes more widespread, the issue of safety surrounding their use is becoming an increasingly important consideration. Itraconazole is effective and well tolerated, with most side effects being minor and reversible. The most common adverse events are gastrointestinal upset, headache, and transient skin reaction. There have also been rare reports of hepatitis. To assess the hepatic safety of pulse and continuous itraconazole in the treatment of onychomycosis. An analysis was performed on all itraconazole clinical trials sponsored by Janssen Research Foundation in the treatment of onychomycosis, where there was an assessment of laboratory safety. A review of the published literature was also undertaken to assess the hepatic safety of itraconazole in common practice. The data indicate that itraconazole pulse treatment is safe, with no significant differences in the number of code 4 abnormalities (baseline value is in the normal range and at least two values, or the last testing in the observation period, exceed twice the upper limit of normal) in the liver function parameters studied: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, and total bilirubin. The incidence of all the code 4 abnormalities was below 2%. In the literature there are reports of symptomatic hepatitis with itraconazole continuous therapy but no published report of symptomatic hepatotoxicity using the pulse regimen. Itraconazole pulse therapy for onychomycosis appears to be safe, especially from the perspective of potential liver damage. In the itraconazole package insert liver function tests are recommended for patients receiving continuous itraconazole for periods of time exceeding 1 month. There is no such monitoring requirement for the pulse regimen unless the patient has a history of underlying hepatic disease, the liver function tests are abnormal at baseline, or at any time that there is the development of signs or symptoms suggestive of liver dysfunction.

Antitumor Effects of Miconazole on Human Colon Carcinoma Xenografts in Nude Mice through Induction of Apoptosis and G0/G1 Cell Cycle Arrest

Miconazole (MIC), a promising oral antifungal agent, has been used worldwide in the treatment of superficial mycosis. In this study, we demonstrated that MIC dose dependently arrested various human cancer cells at the G0/G1 phase of the cell cycle. The protein levels of p53, p21/Cip1, and p27/Kip1 were significantly elevated by MIC treatment in COLO 205 cells. Electrophoretic mobility gel shift assays showed that the nuclear extracts of the MIC-treated COLO 205 cells exerted a significant binding between wild-type p53 and its consensus-binding site present in the p21/Cip1 promoter. These results suggested that the p53-associated signaling pathway is involved in the regulation of MIC-induced cancer cell growth arrest. By immunoblot analysis, we demonstrated that cyclin D3 and cyclin-dependent kinase-4 (CDK4) protein levels were inhibited by MIC treatment in the cancer cells. Significant therapeutic effect was further demonstrated in vivo by treating nude mice bearing COLO 205 tumor xenografts with MIC (50 mg/kg ip). The protein expression of p53 was significantly increased in MIC-treated tumor tissues by immunohistochemical staining and Western blotting analysis. DNA fragmentation and TUNEL assay were performed and demonstrated that apoptosis occurred in tumor tissues treated with MIC. Our study provides the novel mechanisms of antitumor effects of MIC and such results may have significant applications for cancer chemotherapy.

Cryptococcosis in Australasia and the treatment of cryptococcal and other fungal infections with liposomal amphotericin B.

Cryptococcus neoformans is an important fungal pathogen in both immunocompromised and immunocompetent hosts. The mean annual incidence during 1994-1997 was 6.6 cases per million people per year in Australia, and 2.2 cases per million people per year in New Zealand. C. neoformans var. neoformans caused 85% of 312 episodes (98% of episodes in immunocompromised hosts) and C. neoformans var. gattii caused 15% (44% in immunocompetent hosts). The AIDS-specific incidence declined significantly over the 3 years. Mortality from cryptococcosis remains substantial. In trials involving small numbers of AIDS patients, liposomal amphotericin B (AmBisome) was found to be active against C. neoformans, with mycological response rates of 67-85%; however, maintenance therapy with an oral antifungal agent is required indefinitely. In a randomized study of patients with cryptococcal meningitis, AmBisome (4 mg/kg/day) produced mycological eradication in 73% of patients compared with 38% with conventional amphotericin. AmBisome resulted in significantly earlier sterilization of cerebrospinal fluid than conventional amphotericin (7-14 days versus 21 days) and was less nephrotoxic. The benefit of this reduced toxicity is denied to many patients because of an enormous cost barrier. In a survey of the practices of clinical mycologists in Australia, 11 experts responded to a questionnaire survey regarding the use of available lipid preparations. Their indications for use as initial therapy were mucormycosis (7/10), renal failure (7/10), Fusarium infection (2/10) and aspergillosis (2/10). Cryptococcosis, candidosis and febrile neutropenia were rarely regarded as an indication; failed therapy with conventional amphotericin was an indication to use AmBisome for 8/11 respondents. The majority believed that AmBisome was equivalent to conventional amphotericin, with amphotericin B lipid complex and AmBisome equivalent to each other in terms of efficacy. The main barrier to replacement of conventional amphotericin with lipid preparations was seen as an issue of cost.

Drug discovery based on microarray

Gene regulatory networks developed from full genome expression libraries from gene perturbation variant cell lines can be used to quickly and efficiently identify the molecular mechanism of action of drugs or lead compound molecules. We developed an extensive yeast gene expression library consisting of full-genome cDNA array data for over 500 yeast strains each with a single gene disruption. Using this data, combined with dose and time course expression experiments with the oral antifungal agent, we used Boolean network discovery techniques to determine the genes whose expression was most profoundly affected by this drug. Our system identified the gene as the most significantly suppressed target molecule due to exposure to the antifungal agent. This process for network based drug discovery can significantly decrease the time and resources necessary to make rational drug targeting decisions.

Ketoconazole potentiates terfenadine-induced apoptosis in human Hep G2 cells through inhibition of cytochrome p450 3A4 activity.

Terfenadine (TF) is a highly potent histamine H1 receptor antagonist that in clinically effective doses is free of significant central nervous system side effects. Ketoconazole (KT) is a worldwide used oral antifungal agent with a broad spectrum of activity against both superficial and systemic mycosis. Simultaneously administration of KT and TF has been reported to induce several potent symptoms including cardiotoxicity, excitotoxicity, inhibition of blood mononuclear cells proliferation, and cardiovascular toxicity. However, the intracellular molecular mechanisms of TF-KT interactions in cells were still uncertain. In this study, we first demonstrated that TF (5-30 microM) induced apoptosis in several types of human cancer cell lines including human hepatoma (Hep G2), colorectal cancer (COLO 205), and fibroblast (CCD 922SK) cells for 24 h. The cellular responses to TF-induced apoptosis were demonstrated to be associated with the p53-signaling pathway, including induction of p53, p21/Cip1, p27/Kip1, bax protein expression and inhibition of bcl-2 protein expression. To realized the role of H1 receptor involved in TF-induced apoptosis, different H1 receptor antagonists including promethazine, mequitazine, and chlorpheniramin (50-100 microM) were administered and demonstrated that these chemicals cannot induced apoptosis through the H1 receptor signaling pathway. Interestingly, we found that the apoptotic effect of TF (2.5 microM) was significantly potentiated by KT (1 microM) treatment in Hep G2 cells through inhibition of the cytochrome p450 3A4 (CYP 3A4) activity. Such results were demonstrated by decreased of the TF activity with recombinant CYP 3A4, which prepared from baculovirus-infected insect cells. Our results provide the molecular basis of TF-KT interaction and this information should allow more rational forecasting of the risk for TF therapy during co-administration of KT.