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Introduction: Endemic in Latin America, Chagas disease is now becoming a serious global health problem, and yet has no financial viability for the pharmaceutical industry and remains incurable. In 2012, two antimycotic drugs inhibitors of fungal sterol 14α-demethylase (CYP51) - posaconazole and ravuconazole - entered clinical trials. Availability of the X-ray structure of the orthologous enzyme from the causative agent of the disease, protozoan parasite Trypanosoma cruzi, determined in complexes with posaconazole as well as with several experimental protozoa-specific CYP51 inhibitors opens an excellent opportunity to improve the situation., Areas Covered: This article summarizes the information available in PubMed and Google on the outcomes of treatment of the chronic Chagas disease. It also outlines the major features of the T. cruzi CYP51 structure and the possible structure-based strategies for rational design of novel T. cruzi specific drugs., Expert Opinion: There is no doubt that screenings for alternative drug-like molecules as well as mining the T. cruzi genome for novel drug targets are of great value and might eventually lead to groundbreaking discoveries. However, all newly identified molecules must proceed through the long, expensive and low-yielding drug optimization process, and all novel potential drug targets must be validated in terms of their essentiality and druggability. CYP51 is already a well-validated and highly successful target for clinical and agricultural antifungals. With minimal investments into the final stages of their development/trials, T. cruzi-specific CYP51 inhibitors can provide an immediate treatment for Chagas disease, either on their own or in combination with the currently available drugs.

Object: Cushing's disease is a challenging neuroendocrine disorder. Although resection remains the primary treatment option for most patients, the disease persists if there is residual or recurrent tumor. Stereotactic radiosurgery has been used to treat patients with persistent Cushing's disease after a prior resection. The authors report on the long-term risks and benefits of radiosurgery for Cushing's disease., Methods: A retrospective review of a prospectively collected database of radiosurgery patients was undertaken at the University of Virginia. All patients with Cushing's disease treated with Gamma Knife surgery (GKS) were identified. Those without at least 12 months of clinical and radiological follow-up were excluded from this analysis. Rates of endocrine remission, tumor control, and adverse events were assessed. Statistical methods were used to identify favorable and unfavorable prognostic factors., Results: Ninety-six patients with the required follow-up data were identified. The mean tumor margin dose was 22 Gy. The median follow-up was 48 months (range 12-209.8 months). At the last follow-up, remission of Cushing's disease occurred in 70% of patients. The median time to remission among all patients was 16.6 months (range 1-165.7 months). The median time to remission in those who had temporarily stopped taking ketoconazole at the time of GKS was 12.6 months, whereas it was 21.8 months in those who continued to receive ketoconazole (p < 0.012). Tumor control was achieved in 98% of patients. New loss of pituitary function occurred in 36% of patients. New or worsening cranial neuropathies developed in 5 patients after GKS, with the most common involving cranial nerves II and III., Conclusions: Gamma Knife surgery offers a high rate of tumor control and a reasonable rate of endocrine remission in patients with Cushing's disease. The cessation of cortisol-lowering medications around the time of GKS appears to result in a more rapid rate of remission. Delayed hypopituitarism and endocrine recurrence develop in a minority of patients and underscore the need for long-term multidisciplinary follow-up.

Chagas disease, caused by the eukaryotic (protozoan) parasite Trypanosoma cruzi, is an alarming emerging global health problem with no clinical drugs available to treat the chronic stage. Azole inhibitors of sterol 14α-demethylase (CYP51) were proven effective against Chagas, and antifungal drugs posaconazole and ravuconazole have entered clinical trials in Spain, Bolivia, and Argentina. Here we present the x-ray structures of T. cruzi CYP51 in complexes with two alternative drug candidates, pyridine derivatives (S)-(4-chlorophenyl)-1-(4-(4-(trifluoromethyl)phenyl)-piperazin-1-yl)-2-(pyridin-3-yl)ethanone (UDO; Protein Data Bank code 3ZG2) and N-[4-(trifluoromethyl)phenyl]-N-[1-[5-(trifluoromethyl)-2-pyridyl]-4-piperi-dyl]pyridin-3-amine (UDD; Protein Data Bank code 3ZG3). These compounds have been developed by the Drugs for Neglected Diseases initiative (DNDi) and are highly promising antichagasic agents in both cellular and in vivo experiments. The binding parameters and inhibitory effects on sterol 14α-demethylase activity in reconstituted enzyme reactions confirmed UDO and UDD as potent and selective T. cruzi CYP51 inhibitors. Comparative analysis of the pyridine- and azole-bound CYP51 structures uncovered the features that make UDO and UDD T. cruzi CYP51-specific. The structures suggest that although a precise fit between the shape of the inhibitor molecules and T. cruzi CYP51 active site topology underlies their high inhibitory potency, a longer coordination bond between the catalytic heme iron and the pyridine nitrogen implies a weaker influence of pyridines on the iron reduction potential, which may be the basis for the observed selectivity of these compounds toward the target enzyme versus other cytochrome P450s, including human drug-metabolizing P450s. These findings may pave the way for the development of novel CYP51-targeted drugs with optimized metabolic properties that are very much needed for the treatment of human infections caused by eukaryotic microbial pathogens.

Erlotinib is approved for the treatment of non-small cell lung and pancreatic cancers, and is metabolized by CYP3A4. Inducers and inhibitors of CYP3A enzymes such as ritonavir and efavirenz, respectively, may be used as part of the highly active antiretroviral therapy drugs to treat patients with human immunodeficiency virus (HIV). When HIV patients with a malignancy need treatment with erlotinib, there is a potential of as-yet-undefined drug-drug interaction. We evaluated these interactions using human hepatocytes benchmarked against the interaction of erlotinib with ketoconazole and rifampin, the archetype cytochrome P450 inhibitor and inducer, respectively. Hepatocytes were treated with vehicle [0.1% dimethylsulfoxide, ritonavir (10 μM)], ketoconazole (10 μM), efavirenz (10 μM), or rifampin (10 μM) for 4 days. On day 5, erlotinib (5 μM) was incubated with the above agents for another 24-48 hours. Concentrations of erlotinib and O-desmethyl erlotinib were quantitated in collected samples (combined lysate and medium) using liquid chromatography and tandem mass spectrometry. The half-life (t(½)) of erlotinib increased from 10.6 ± 2.6 to 153 ± 80 and 23.9 ± 4.8 hours, respectively, upon treatment with ritonavir and ketoconazole. The apparent intrinsic clearance (C(Lint, app)) of erlotinib was lowered 16-fold by ritonavir and 1.9-fold by ketoconazole. Efavirenz and rifampin decreased t1/2 of erlotinib from 10.3 ± 1.1 to 5.0 ± 1.5 and 3.4 ± 0.2 hours, respectively. Efavirenz and rifampin increased the C(Lint, app) of erlotinib by 2.2- and 2-fold, respectively. Our results suggest that to achieve desired drug exposure, the clinically used dose (150 mg daily) of erlotinib may have to be significantly reduced (25 mg every other day) or increased (300 mg daily), respectively, when ritonavir or efavirenz is coadministered.

Sterol 14α-demethylase (CYP51) is a cytochrome P450 heme thiolate containing enzyme involved in biosynthesis of membrane sterols, including sterol in animals, ergosterol in fungi, and a variety of C24-modified sterols in plants and protozoa. Several clinical drugs have been developed to reduce the impact of fungal diseases, but their clinical uses have been limited by the emergence of drug resistance and insufficiencies in their antifungal activity. Therefore, in order to identify potential CYP51 inhibitors, we have implemented a virtual screening (VS) protocol by using both phase shape and pharmacophore model (AHHRR) against Asinex, ChemBridge and Maybridge databases. A filtering protocol, including Lipinski filter, number of rotatable bonds and different precisions of molecular docking was applied in hits selection. The results indicated that both shape-based and pharmacophore-based screening yielded the best result with potential inhibitors. The searched compounds were also evaluated with ADME properties, which show excellent pharmacokinetic properties under the acceptable range. We identified potential CYP51 inhibitors for further investigation, they could also be employed to design ligands with enhanced inhibitory potencies and to predict the potencies of analogs to guide synthesis/or prepare synthetic antifungal analogs against CYP51.

Background: Frontline treatment of metastatic castration-resistant prostate cancer (mCRPC) consists of docetaxel-based chemotherapy. The median time to progression (TTP) from chemotherapy initiation is 6 to 8 months. Ketoconazole, a nonspecific cytochrome P17 inhibitor (CYP17i), blocks adrenal androgen synthesis. Low-dose ketoconazole (LDK), (200 mg three times daily [t.d.s]) has shown activity in mCRPC after progression to androgen deprivation. The role of a CYP17i after docetaxel treatment in the maintenance setting has been unexplored., Methods: We identified 38 patients with mCRPC who showed progression to luteinizing hormone releasing-hormone agonists (LHRHa) and who were treated with a median of 7 cycles of frontline three-weekly docetaxel (75 mg/m(2)) plus prednisone (10 mg/d) and LHRHa. Medical charts of 20 patients who showed no progression to docetaxel were reviewed. After the last docetaxel cycle, 10 patients received LDK maintenance treatment plus prednisone (10 mg/d) and LHRHa, whereas 10 patients received LHRHa alone. TTP was the primary endpoint., Results: After a follow-up of 27 months, disease in all patients receiving LHRHa alone progressed, whereas 8/10 patients progressed to maintenance therapy. Median TTP from docetaxel initiation was 11.5 months (95% confidence interval [CI], 6.3-16.6) for maintenance therapy and 9.2 months (95% CI, 8.5-9.9) for LHRHa alone (P = .047). The maintenance treatment was well tolerated. Only 1 patient experienced a grade 4 adverse event due to a nonsymptomatic pulmonary embolism., Conclusion: This is the first study evaluating a CYP17i for maintenance therapy after docetaxel therapy. We showed a 2-month significant benefit in TTP for patients with mCRPC treated with LDK maintenance therapy after docetaxel, with a favorable toxicity profile. A large prospective randomized study using a CYP17i is warranted., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Female pattern hair loss (FPHL) is the most common cause of alopecia in women. FPHL is characterized histologically with increased numbers of miniaturized, velluslike hair follicles. The goal of treatment of FPHL is to arrest hair loss progression and stimulate hair regrowth. The treatments for FPHL can be divided into androgen-dependent and androgen-independent. There is an important adjuvant role for nutritional supplements, light therapy, and hair transplants. All treatments work best when initiated early. Combinations of treatments tend to be more efficacious., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Invasive fungal diseases are associated with significant morbidity and mortality in immunocompromized patients. Voriconazole is the first line treatment of invasive aspergillosis, and has been successfully used in other invasive fungal infections, such as candidiasis, fusariosis or scedosporidiosis. Voriconazole has non-linear pharmacokinetics and undergoes extensive hepatic metabolism by the cytochrome P450 system that depends on age, genetic factors, and interactions with other drugs. Thus, significant interpatient variability is observed after administration of the same dose. Additionally, the therapeutic window is narrow, with high risk of side effects at serum levels 3-5 times higher than the minimal threshold for efficacy. Therefore, the knowledge of pharmacological properties, metabolism, interactions, dosage indications in various populations and side effects is crucial. Therapeutic drug monitoring can help maximize the efficacy and minimize the risk of toxicity. Pharmacological, mycological and clinical aspects of the treatment with voriconazole are summarized in order to optimize its use in daily clinical practice.

Glucocorticoid hypersensitivity syndrome has been reported to date only in several patients. This article describes a unique case of this syndrome in a 24-year old female admitted to hospital because of arterial hypertension and obesity. Although her clinical picture suggested Cushing's syndrome, she had low adrenocorticotropic hormone (ACTH) and cortisol levels with a poor response to corticotrophin-releasing hormone and Synacthen. In turn, an overnight dexamethasone suppression test with 0.25 mg of dexamethasone led to a dramatic decrease in morning cortisol. A diagnosis of glucocorticoid hypersensitivity was made and the patient started treatment with ketoconazole and cabergoline, which resulted in some clinical improvement. This case illustrates the need for clinical awareness of glucocorticoid hypersensitivity in patients suspected of Cushing's syndrome.

Data concerning pregnancy in women with Cushing's disease treated by gamma-knife (GK) are scanty. We present and discuss the course and outcome of five pregnancies in two women with Cushing's disease (CD), the first of whom was treated only by GK, and the second one treated by surgery, GK and ketoconazole. In the first patient, pregnancy was uneventful and full-term. During gestation, plasma ACTH, serum cortisol and 24-h urinary free cortisol (UFC) levels were steady, and always in the normal range for healthy non-pregnant individuals. The newborn was healthy and normal-weight. In the second woman, two pregnancies, occurring 3 years after GK and few months after ketoconazole withdrawal, were interrupted by spontaneous abortion or placental disruption despite normal cortisol levels. This patient became again pregnant 3 years later and delivered vaginally a healthy full-term infant. Seven months after the delivery, the patient became pregnant again and at the 39th week of gestation delivered vaginally a healthy male. Hypoprolactinemia and/or central hypothyroidism occurred in both cases. In women with CD treated by GK, pregnancy can occur. However, pregnancy is at risk even when ACTH and cortisol levels are normalized by treatment. After GK, evaluation of pituitary function is mandatory due to the risk of hypopituitarism.

Bilateral macronodular adrenocortical disease as a part of McCune Albright Syndrome (MAS) is the most common cause of endogenous Cushing's syndrome (CS) in infancy. Adrenocortical tumors causing CS in infancy are extremely rare. We report the case of a girl with CS who presented at age 4 months with obesity and growth retardation. Her 8 am paired cortisol and adrenocorticotropic hormone levels were 49.3 µg/dL and <1 pg/mL, respectively with non-suppressed serum cortisol (41 µg/dL) on high-dose dexamethasone suppression test. Abdominal computed tomography scan demonstrated a 5.3x4.8x3.7 cm homogenous left adrenal mass with distinct borders. Laparotomy following pre-operative stabilization with ketoconazole 200 mg/day, revealed a 7.5x5x4 cm lobulated left adrenal mass with intact capsule and weighing 115 grams. Histopathology showed small round adrenal tumor cells with increased nucleo-cytoplasmic ratio and prominent nucleoli. The cells were separated by fibrous septae without any evidence of vascular or capsular invasion- findings consistent with adrenal adenoma. On the 8th post-operative day, after withholding hydrocortisone supplementation, the 8 am cortisol level was <1 µg/dL, suggestive of biochemical remission of CS. The patient improved clinically with a 7.5 kg weight loss over the next 3.5 months. This is perhaps the youngest ever reported infant with CS due to adrenal adenoma. Lack of clinical and biochemical evidence of hyperandrogenism as well as the benign histology in spite of the large tumor size (>7 cm diameter; 115 g) are some of the unique features of our patient.

Cushing syndrome is associated with significant morbidity and mortality if left untreated because of associated metabolic and cardiovascular complications. An extremely ill patient with Cushing's syndrome caused by adrenocorticotropic hormone producing pituitary macro adenoma responded dramatically to ketoconazole and cabergoline treatment. His 4 month long medical treatment resulted in improvement of hypercotisolism clinically and biochemically and in complete disappearance of pituitary macro adenoma without any surgical intervention.

Background: Mutations of the CYP24A1 gene, which encodes the 1,25-dihydroxyvitamin D-24-hydroxylase cytochrome P450, Cyp24A1, are predicted to result in elevated 1,25-dihydroxyvitamin D concentrations, hypercalcemia, hypercalciuria, nephrolithiasis, and bone disease. Treatment of hypercalcemia associated with CYP24A1 gene mutations has not been described., Methods: The genetic basis of a syndrome in a 44-yr-old Caucasian male characterized by intermittent hypercalcemia, hypercalciuria, elevated serum 1,25-dihydroxyvitamin D, undetectable serum 24,25-dihydroxyvitamin D, metabolically active nephrolithiasis, and reduced bone mineral density of the lumbar spine was examined. Sequencing of the CYP24A1 gene and biochemical and genetic analysis of seven family members in three generations was carried out. Because of hypercalcemia, hypercalciuria, and metabolically active nephrolithiasis, the patient was treated with a cytochrome 3A inhibitor, ketoconazole, 200 mg orally every 8 h, for 2 months., Results: The sequence of the CYP24A1 gene showed two canonical splice junction mutations in the proband. Analysis of family members showed a phenotype associated one or both mutations, suggesting autosomal dominant transmission with partial penetrance of the trait. After therapy with ketoconazole, statistically significant reductions in previously elevated urinary calcium into the normal range were noted. Previously elevated serum 1,25-dihydroxyvitamin D and calcium concentrations decreased, and previously decreased PTH concentrations increased into the normal range, but the differences were not statistically significant., Conclusions: In a syndrome characterized by intermittent hypercalcemia, hypercalciuria, elevated 1,25-dihydroxyvitamin D, undetectable 24,25-dihydroxyvitamin D concentrations, splice junction mutations of the CYP24A1 gene, and autosomal dominant transmission of the trait, treatment with ketoconazole is useful in reducing urinary calcium.

An in vivo study in the laboratory rat model has been carried out to monitor morphological changes in adult Fasciola hepatica over a 4-day period resulting from co-treatment with triclabendazole (TCBZ) and ketoconazole (KTZ), a cytochrome P450 inhibitor. Rats were infected with the triclabendazole-resistant Oberon isolate of F. hepatica, dosed orally with triclabendazole at a dosage of 10mg/kg live weight and ketoconazole at a dosage of 10mg/kg live weight. Flukes were recovered at 24, 48, 72 and 96 h post-treatment (p.t.) and changes to fluke ultrastructure were assessed using transmission electron microscopy (TEM). Results showed an increase in the severity of changes to the fluke ultrastructure with time p.t. Swelling of the basal infolds and the associated mucopolysaccharide masses became more severe with time. Golgi complexes, if present, were greatly reduced in size and number by 96 h p.t., and sub-tegumental flooding was seen from the 72 h time-period onwards. Some sloughing of the tegumental covering over the spines was observed at 96 h p.t. The results demonstrated that the Oberon isolate is more sensitive to TCBZ action in the presence of KTZ than to TCBZ alone, reinforcing the idea that altered drug metabolism is involved in the resistance mechanism. Moreover, they support the concept that TCBZ+inhibitor combinations (aimed at altering drug pharmacokinetics and potentiating the action of TCBZ) could be used in the treatment of TCBZ-R populations of F. hepatica., (© 2011 Elsevier B.V. All rights reserved.)

Background: Hypercortisolemia has been suggested as a primary hormonal mediator of whole-body catabolism following severe burn injury. Ketoconazole, an anti-fungal agent, inhibits cortisol synthesis. We, therefore, studied the effect of ketoconazole on post-burn cortisol levels and the hyper-catabolic response in a prospective randomized trial (block randomization 2:1)., Methodology/principal Findings: Fifty-five severely burned pediatric patients with >30% total body surface area (TBSA) burns were enrolled in this trial. Patients were randomized to receive standard care plus either placebo (controls, n = 38) or ketoconazole (n = 23). Demographics, clinical data, serum hormone levels, serum cytokine expression profiles, organ function, hypermetabolism measures, muscle protein synthesis, incidence of wound infection sepsis, and body composition were obtained throughout the acute hospital course. Statistical analysis was performed using Fisher's exact test, Student's t-test, and parametric and non-parametric two-way repeated measures analysis of variance where applicable. Patients were similar in demographics, age, and TBSA burned. Ketoconazole effectively blocked cortisol production, as indicated by normalization of the 8-fold elevation in urine cortisol levels [F(1, 376) = 85.34, p<.001] with the initiation of treatment. However, there were no significant differences in the inflammatory response, acute-phase proteins, body composition, muscle protein breakdown or synthesis, or organ function between groups., Conclusions: Both groups were markedly hypermetabolic and catabolic throughout the acute hospital stay. Normalization of hypercortisolemia with ketoconazole therapy had no effect on whole-body catabolism or the post-burn inflammatory or hypermetabolic response, suggesting that hypercortisolemia does not play a central role in the post-burn hypermetabolic catabolic response., Trial Registration: ClinicalTrials.gov NCT00675714; and NCT00673309.

Background/aims: To evaluate the ovarian-protective effects of clotrimazole on ovarian ischemia/reperfusion injury in a rat ovarian-torsion model., Methods: 32 Sprague-Dawley rats were randomly divided into four groups: (1) ischemia group (n = 8) in which only left adnexal torsion was performed for 2 h, but no treatment was given; (2) vehicle group (n = 8) in which left adnexal torsion was performed for 2 h and at the end of 2 h ischemia polyethylene glycol (3% PEG, 1 ml, i.p.) was administered and a 24-hour reperfusion was continued; (3) clotrimazole group (n = 8) in which left adnexal torsion was performed for 2 h and at the end of 2 h ischemia clotrimazole (30 mg/kg, i.p.) was administered and a 24-hour reperfusion was continued, and (4) control group (sham-operated, n = 6) in which no adnexal torsion and no treatment were given. The criteria for ovarian ischemia were follicular cell degeneration, vascular congestion, hemorrhage and infiltration by inflammatory cells. Each specimen was scored for each criterion (0, none; 1, mild; 2, moderate; 3, severe)., Results: Clotrimazole significantly decreased plasma levels of serum malondialdehyde, ischemia-modified albumin, and total oxidant status., Conclusion: This study showed the ovarian-protective effects of clotrimazole on ovarian ischemia/reperfusion injury., (Copyright © 2012 S. Karger AG, Basel.)

Thailand is not an endemic area for leishmaniasis. Several cases of autochthonous visceral leishmaniasis have been reported from Thailand but cutaneous leishmaniasis has never been reported. We reported a three-year-old girl who presented with a chronic ulcer on her cheek which proved to be cutaneous leishmaniasis. The diagnosis was made by finding amastigotes on skin biopsy; the patient had a therapeutic response to itraconazole.

Leishmaniasis is a major health problem that affects populations of ∼90 countries worldwide, with no vaccine and only a few moderately effective drugs. Here we report the structure/function characterization of sterol 14α-demethylase (CYP51) from Leishmania infantum. The enzyme catalyzes removal of the 14α-methyl group from sterol precursors. The reaction is essential for membrane biogenesis and therefore has great potential to become a target for antileishmanial chemotherapy. Although L. infantum CYP51 prefers C4-monomethylated sterol substrates such as C4-norlanosterol and obtusifoliol (V(max) of ∼10 and 8 min(-1), respectively), it is also found to 14α-demethylate C4-dimethylated lanosterol (V(max) = 0.9 min(-1)) and C4-desmethylated 14α-methylzymosterol (V(max) = 1.9 min(-1)). Binding parameters with six sterols were tested, with K(d) values ranging from 0.25 to 1.4 μM. Thus, L. infantum CYP51 is the first example of a plant-like sterol 14α-demethylase, where requirements toward the composition of the C4 atom substituents are not strict, indicative of possible branching in the postsqualene portion of sterol biosynthesis in the parasite. Comparative analysis of three CYP51 substrate binding cavities (Trypanosoma brucei, Trypanosoma cruzi, and L. infantum) suggests that substrate preferences of plant- and fungal-like protozoan CYP51s largely depend on the differences in the enzyme active site topology. These minor structural differences are also likely to underlie CYP51 catalytic rates and drug susceptibility and can be used to design potent and specific inhibitors.

During the past two decades, the incidence of invasive fungal infections has been increasing dramatically. Clinical available antifungal agents have several drawbacks such as limited potency and spectrum, drug related toxicity, non-optimal pharmacokinetics, and severe resistance. There is an emergent need to develop new antifungal drugs with novel chemical structures and novel mechanism of action. This review will focus on the most significant achievements in the discovery of antifungal lead structures within last few years. In particular, we pay more attention on the structure-activity relationship of antifungal leads and provide perspectives for future antifungal drug discovery.