Dapsone

The current practice of using calibration curves with narrow concentration ranges during bioanalysis of new chemical entities has some limitations and is time consuming. In the present study we describe a split calibration curve approach, where sample dilution and repeat analysis can be avoided without compromising the quality and integrity of the data obtained. A split calibration curve approach is employed to determine the drug concentration in plasma samples with accuracy and precision over a wide dynamic range of approximately 0.6 to 15,000 ng/ml for dapsone and approximately 1 to 25,000 ng/ml for cyclophosphamide and glipizide. A wide dynamic range of concentrations for these three compounds was used in the current study to construct split calibration curves and was successfully validated for sample analysis in a single run. Using this method, repeat analysis of samples can be avoided. This is useful for the bioanalysis of toxicokinetic studies with wide dose ranges and studies...

Behçet’s disease (BD) is a multisystemic disorder of unknown etiology characterized by the “triple symptom complex” consisting of recurrent oral aphthosis, genital ulcers, and chronic relapsing bilateral uveitis. Recurrent mucocutaneous lesions are generally considered the hallmark of the disease, being the most common symptoms presenting at the onset of disease. Although the improvement of knowledge about the pathogenetic mechanism added important changes in the treatment management of BD clinical manifestations, thus avoiding the appearance of serious life-threatening complications which are disease related, the mucocutaneous lesions are still the most nagging clinical manifestations to be treated. In this work we reviewed the current state of knowledge regarding the therapeutic approaches for mucocutaneous lesions of BD mainly based on controlled studies to provide a rational framework for selecting the appropriate therapy for treating these troublesome features of the disease.

The theoretical charge density study for the gas phase of anti-leprosy drug Dapsone has been carried out in the light of the theory of atoms in molecules using density functional theory employing B3LYP(6-311G++(d, p) hybrid functional completed with dispersion corrections. The Hirshfeld surface analysis as well as fingerprint plots has been utilized to visualize and quantify the intermolecular contacts present in the molecule. The topological properties such as electron density and its Laplacian, delocalization index have been elucidated to throw light into the chemical bonding and atomic and molecular details. The electron localization function has been used to visualize and deduce information on the lone pair and the subshells of the Cl atom. The electrostatic potential visualizes the positive and negative electrostatic potential regions which are susceptible to nucleophilic and electrophilic attack. On the whole, this study provides an exact mechanism, interaction, and topologica...

In this report we describe an animal experiment which showed delayed clearance of preformed 125I-HSA-anti-HSA immune complexes (with five times excess HSA) from the circulation of mice treated with antileprosy drugs (dapsone, clofazimine, and rifampin--multidrug therapy for 7 days) in comparison with normal (untreated) mice. The results also showed delayed retention of the preformed immune complexes in the spleen and kidneys of the antileprosy-drug-treated animals. The exact mechanism of the delayed handling of preformed immune complexes in mice fed antileprosy drugs could not be ascertained. However, in light of the anticomplementary effects of clofazimine and dapsone, as reported earlier, and in light of the large accumulation of clofazimine and rifampin in macrophages, it has been postulated that in the drug-fed animals either the immune complexes could not be phagocytosed by macrophages, through the avenue of their C3b receptors, or the immune complexes could not be downgraded e...

Actinomycetoma is a chronic infection resulting from aerobic Actinomycetes. The major agents are Nocardia brasiliensis, Actinomadura madurae, and Streptomyces somaliensis. The most frequent topographies are the lower and upper limbs. The prognosis of this disease is determined by several factors, such as etiologic agent, clinical topography, and depth of disease (degree of involvement, visceral, and bone affection). The purpose of this paper was to present our experience with actinomycetoma of the perianal region. This study comprises 20 cases of perianal actinomycetoma, all of which were clinically and microbiologically proven by direct examinations, cultures, and biopsies. Clinical responses to the two principal treatment regimes used [combination of trimethoprim-sulfamethoxazole (TMS/SMX) and diaminodiphenylsulfone (DDS) or amikacine plus TMS/SMX] are reported. Most of the cases were male (17/20, 85%), the mean age was 42.1 years, and the farmers predominated (90%). The principal etiologic agent isolated was N. brasiliensis (85%). Perianal actinomycetoma is a rare entity. Differential diagnosis with anal sinuses, hydroadenitis, and cutaneous tuberculosis must be made in endemic areas by performing mycologic tests and biopsies. Treatment depends on the etiologic agent involved and the patient's condition.

To analyze the trends of case detection and other indicators of leprosy in China during 1985-2002. Data reported by each province were collected by China National Leprosy Database in Nanjing P.R. China. All data about registered cases were put into computer for analysis. From 1985 to 2002, a total of 49,477 new leprosy cases had been detected. Among them, 69.5% were multibacillary cases and 25.4% had grade 2 disability. The child cases aged below 15 years accounted for 3.74% of total cases. Totally, 5824 cases and 303 cases relapsed after dapsone (DDS) mono-therapy and multidrug therapy (MDT), respectively. Case detection showed a marked reduction from 0.47/100,000 in 1985 to 0.18/100,000 in 1993 although there were several spurts due to operational factors. From 1994, case detection showed no significant decline. The grade 2 disability among new patients decreased from 31.4% in 1985 to 23.4% in 2002. The child case detection rate among new cases fluctuated between 2.70%-3.56% from ...

Effective and affordable treatment of malaria is critical in the face of resistance of Plasmodium falciparum to chloroquine (CQ) and sulfadoxine-pyrimethamine (SP). We conducted a randomized controlled trial comparing the efficacy of chlorproguanil-dapsone (CD) with a combination SP plus CQ in children in Nigeria less than five years of age with malaria. Of 264 children enrolled, 122 (89.7%) and 118 (92.2%) completed the study in the SP + CQ and CD groups, respectively. By day 3, 96 (78.7%) and 94 (79.7%) had cleared their parasitemia (P = 0.79), and 107 (87.7%) and 109 (92.4%) were symptom free (P = 0.32) in the SP + CQ and CD groups, respectively. Adequate clinical and parasitologic response at day 14 occurred in 111 (94.1%; 95% confidence interval [CI] = 91.6-95.7%) in the CD group and 113 (92.6%; 95% CI = 89.9-94.3%) in the SP + CQ group (P = 0.85). SP + CQ and CD had similar antimalarial efficacy and still provide affordable treatment of uncomplicated malaria in northcentral Ni...

Mutations in the Dihydropteroate synthase (DHPS) gene of Pneumocystis jirovecii associate with failure of sulfa prophylaxis. They can develop by selection in patients receiving sulfa drugs, or be acquired via person-to-person transmission. DHPS mutations raise concern about decreasing efficacy of sulfa drugs, the main available therapeutic tool for Pneumocystis pneumonia (PCP). The prevalence of Pneumocystis DHPS mutations was examined in Pneumocystis isolates from 56 sulfa-prophylaxis-naive adults with first-episode of PCP from 2002-2010 in Santiago, Chile. Their clinical history was reviewed to analyze the effect of these mutations on response to trimethoprim-sulfamethoxazole (TMP-SMZ) therapy and outcome. Mutant genotypes occurred in 22(48%) of 46 HIV-infected, and in 5(50%) of 10 HIV-uninfected patients. Compared to patients with wild type genotype, those with mutant genotypes were more likely to experience sulfa treatment-limiting adverse reactions, and, to have a twice-longer ...

Acne fulminans is a rare condition and the most severe form of acne. It involves the sudden onset of febrile and multisystemic symptoms, with poor response to ordinary therapy in patients who previously had mild to moderate acne. It is characterized by hemorrhagic ulcerative crusting lesions on the face, chest and upper back. The authors report a case of acne fulminans that was successfully treated with oral prednisone and dapsone.

Bullous pemphigoid is an autoimmune subepidermal bullous dermatosis more commonly observed in the elderly (over 70 years old). Autoantibodies are produced for specific antigens of the epidermal basement membrane zone: BP 180 and BP 230 (hemidesmosome proteins). We report three cases of bullous pemphigoid in adults younger than 50 years old, discussing the clinical characteristics of the disease in younger patients.

Stroke is a frequent cause of death and the first of disability in the world population. We have shown that dapsone acts as an antioxidant, antiinflammatory and antiapoptotic agent after brain Ischemia reperfusion (I/R) in rats; however, its therapeutic efficacy, measured by imaging has not been characterized. In this context, the aim of this study as to evaluate the neuroprotective effect of dapsone by magnetic resonance image (MRI) and to correlate imaging markers with motor function and oxidative stress after transient cerebral ischemia and reperfusion (I/R). We used male rats throughout the experiment. Functional deficit after I/R was assessed by using Longa scale. The area of brain tissue damage was measured by histology. The nuclear factor erythroid 2-related factor 2 (Nrf-2) and the amount of reactive oxygen species (ROS) were measured as biomarkers of oxidative stress. Finally, diffusive MRI was employed to measure the fractional anisotropy (FA), as a MRI marker of the patho...

Drug-induced acute hemolytic anemia led to the discovery of G6PD deficiency. However, most clinical data are from isolated case reports. In 2 clinical trials of antimalarial preparations containing dapsone (4,4′-diaminodiphenylsulfone; 2.5 mg/kg once daily for 3 days), 95 G6PD-deficient hemizygous boys, 24 G6PD-deficient homozygous girls, and 200 girls heterozygous for G6PD deficiency received this agent. In the first 2 groups, there was a maximum decrease in hemoglobin averaging −2.64 g/dL (range −6.70 to +0.30 g/dL), which was significantly greater than for the comparator group receiving artemether-lumefantrine (adjusted difference −1.46 g/dL; 95% confidence interval −1.76, −1.15). Hemoglobin concentrations were decreased by ≥ 40% versus pretreatment in 24/119 (20.2%) of the G6PD-deficient children; 13/119 (10.9%) required blood transfusion. In the heterozygous girls, the mean maximum decrease in hemoglobin was −1.83 g/dL (range +0.90 to −5.20 g/dL); 1 in 200 (0.5%) required blood...

Mean molar phenotypic ratios obtained after administering metoprolol (mean change of −11%) or tolbutamide (mean change of −0.3%) alone, were not significantly different from those obtained when other drugs were co-administered (P > 0.05). The mean within-subject ...

Behçet’s disease (BD) is a multisystemic disorder of unknown etiology characterized by the “triple symptom complex” consisting of recurrent oral aphthosis, genital ulcers, and chronic relapsing bilateral uveitis. Recurrent mucocutaneous lesions are generally considered the hallmark of the disease, being the most common symptoms presenting at the onset of disease. Although the improvement of knowledge about the pathogenetic mechanism added important changes in the treatment management of BD clinical manifestations, thus avoiding the appearance of serious life-threatening complications which are disease related, the mucocutaneous lesions are still the most nagging clinical manifestations to be treated. In this work we reviewed the current state of knowledge regarding the therapeutic approaches for mucocutaneous lesions of BD mainly based on controlled studies to provide a rational framework for selecting the appropriate therapy for treating these troublesome features of the disease.

Blood-brain barrier (BBB) dysfunction is a key event in the development of many central nervous system (CNS) diseases, such as septic encephalopathy and stroke. 4,4'-Diaminodiphenylsulfone (DDS, Dapsone) has displayed neuroprotective effect, but whether DDS has protective role on BBB integrity is not clear. This study was designed to examine the effect of DDS on lipopolysaccharide (LPS)-induced BBB disruption and oxidative stress in brain vessels. Using in vivo multiphoton imaging, we found that DDS administration significantly restored BBB integrity compromised by LPS. DDS also increased the expression of tight junction proteins occludin, zona occludens-1 (ZO-1) and claudin-5 in brain vessels. Level of reactive oxygen species (ROS) was reduced by DDS treatment, which may due to decreased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and NOX2 expression. Our results showed that LPS-induced BBB dysfunction could be attenuated by DDS, indicated that DDS has ...

The granuloma faciale is a rare and benign skin disease of unknown etiology, characterized by chronic leukocitoclastic vasculitis. It is characterized by skin lesions predominantly facial whose course is chronic and slowly progressive. The diagnosis is based on clinical features, histopathology and, more recently, in dermoscopy. We describe the case of a male patient, 40 years old, with a sarcoid lesion on the malar site, whose histopathological examination revealed a mixed inflammatory infiltrate with presence of Grenz zone. Dermoscopy revealed a pink background with white striations. The definitive diagnosis is made by histopathologic evaluation, and dermatoscopy can be helpful. It is known to be resistant to therapy, oral medications, intralesional and surgical procedures are options.

Eighty-four healthy Chinese male control subjects derived from an occupation-based case-control study of bladder cancer were evaluated for hepatic N-acetyltransferase activity by dapsone and for NAT2 genotype using allele-specific amplification of peripheral leukocyte DNA by the polymerase chain reaction. Fifty-nine percent of the overall variation in acetylation activity was explained by genotype (p < 0.0001). The remaining variation in acetylation was not associated with dapsone N-hydroxylation activity, age, current smoking status, or weight in the study population, or within any genotype subgroup. Although acetylation activity in the homozygous mutant group did not overlap with the other genotype categories, there was moderate overlap in acetylation between the heterozygous mutant and wildtype groups, and substantial variation in acetylation within them. Considering all subjects with the identical NAT2 genotype as phenotypically similar and all subjects with differing NAT2 genotypes as phenotypically distinct may result in misclassification of metabolic risk factors in epidemiological investigations. As such, it would seem prudent, where possible, to collect both acetylation phenotype and NAT2 genotype data, since the advantages and limitations of these two sources of information complement, and serve to assess the accuracy of each other.