Acute generalized exanthematous pustulosis: Analysis of cases managed in a Tunisian tertiary hospital

Acute generalized exanthematous pustulosis (AGEP) is a severe and life-threatening cutaneous adverse reaction. Drug-induced AGEP is mainly related to antibiotics. More recently, AGEP following spider bites has been increasingly described. Treatment includes withdrawal of the offending drug and supportive care. In Tunisia, data concerning severe cutaneous adverse reactions (SCARs) in general and especially AGEP is lacking. Herein, we conducted a retrospective study to investigate the epidemiological, clinical characteristics and etiologies of AGEP referred to the Dermatology department. Our study included 32 cases of AGEP. AGEP cases occurred in overall 8.9% of all SCARs referred to the department during the same period study. The majority were females (24 women and 7 men). The median age of the patients was 33 years. A history of psoriasis was reported in 16.1% of patients. All patients presented with an extensive erythematous rash with pinhead pustules. Neutrophil hyperleukocytosis (greater than 7000/mm3) was noted in 17 patients (63% of cases). It was associated with hypereosinophilia exceeding 500 elements/mm3 in 8 cases (29.6%). Drug-induced AGEP was reported in 53% of cases. Antibiotics were implicated in the majority of cases. Delay in onset ranged from 15hours to 7 days, with an average of 2.8 days. A non-drug-induced etiology was considered if the pharmacological investigation was negative, or if a clear non-drug trigger was found. It was retained in ten cases (48.4% of all observations). Spider bites were revealed in 8 cases. AGEP represents a severe, usually drug-related skin reaction. It is classified as a type IVd reaction mediating T cell-related sterile neutrophilic inflammatory response. It typically occurs within 24-48 h of ingestion of the offending drug. Antibiotics are the most common drug family to cause AGEP. Spider bites were involved in 25.8% of cases in our study, as important as antibiotic-induced AGEP. Analysis of the particularities of AGEP according to etiology, whether drug-induced or not, revealed the presence of an initial escarotic lesion (P=0.01) and the finding of blood hypereosinophilia (P=0.014) in the non-drug AGEP group were the distinguishing features. Blood hyperesoniophilia, more frequent in the non-drug AGEP group, suggests a pathophysiology probably different from that of the drug AGEP group. Clinicians should be aware of both etiologies. Our study focuses on the importance of AGEP associated with spider bite as a potential triggering factor in Tunisia.

HPLC-DAD Analysis and Investigation of Biological Properties of the Leaves of Globularia alypum (L.), Infusion Extract

Globularia alypum L. (GA) belonging to the Globulariaceae family is a Mediterranean plant which is widely used in traditional Tunisian medicine. The aim of this study was to investigate the phytochemical composition, antioxidant, anti-arthritic, antiproliferative, antibacterial and antibiofilm potential of aqueous GA leaf extracts (AGAL). Quantitative analyses of the different constituents of extracts were evaluated by high-performance liquid chromatography with photodiode-array detection (HPLC-DAD). Spectrophotometric methods and chemical tests were used for antioxidant and anti-arthritic activities. The antiproliferative study was evaluated using colorectal cancer SW620 cells, while the antibacterial assessment and analysis of the antibiofilm effects were determined by the microdilution method and the crystal violet assay, respectively. AGAL extracts presented several components, mainly Nepetin-7-Glucoside and trans-ferrulic acid. The results showed that they had an important antioxidant (IC50 = 0.34; 0.38 and 1.20 mg/mL) and anti-arthritic (IC50 = 2.94 mg/mL) properties, and these effects are displayed in a dose-dependent manner. In addition, this extract demonstrated significant antiproliferative (IC50 = 50 µg/mL), antibacterial (MIC = 6.25 mg/mL and MBC = 6.25 mg/mL), and antibiofilm (59.70% at 25 mg/mL) properties especially against S. aureus. The results achieved confirm the important role of this plant as a source of therapeutic activities.

Pristinamycin-induced toxic epidermal necrolysis: A case report

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute, life-threatening and rare severe cutaneous adverse reactions induced by drugs in most cases. The drugs most often reported to be implicated in inducing TEN/SJS are allopurinol, antibacterial sulfonamides, antiepileptic drugs and oxicam. Pristinamycin is an oral streptogramin antibiotic with bactericidal activity against Gram-positive bacteria that is rarely linked to TEN. Typically, this condition develops 4-28 days after drug exposure, Herein, we report a case of a 71-year-old female who developed TEN within 3 days of administration of pristinamycin and was managed successfully with supportive care, including intravenous fluids, pain control, prophylactic antibiotics and intravenous methylprednisolone. This case of rapidly developing SJS/TEN after administration of pristinamycin highlights the possibility that these complications can develop within only a few days following ingestion of drugs thought to be probably safe.

Phytochemical Analysis and Assessment of Biological Properties of Essential Oils Obtained from Thyme and Rosmarinus Species

BACKGROUND

The plant species Thymus algeriensis (TA); Thymus capitatus (TC) and Rosmarinus officinalis (RO), are widely used in traditional medicine in Tunisia. The bioactivities of their essential oils have also been reported previously. The main objective of this work was to assess the phytochemical composition, the antioxidant activity, cytotoxic potential and the antibacterial, antifungal, of the essential oil (EO) of these plants.

METHODS

Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify and quantify the constituents of the tested EO. Chemical tests, and spectrophotometric methods were used for antioxidant activities and for the screening and quantification of phytochemicals. The cytotoxic potential of the EO was checked using HCT 116 cultures. The extracts were evaluated for their antibacterial potential by the microdilution method. Antifungal activities were tested using the Poisoned food technique against Aspergillus niger and Aspergillus flavus.

RESULTS

The EO of tested plants presented several components, mainly monoterpenes and sesquiterpenes. The results revealed that T. capitatus EO is not toxic compared to the other tested samples. Phenolic compounds were detected and this EO showed excellent antioxidant activity presenting dosedependent relationship. Regarding antimicrobial activity, T. capitatus EO, also had the highest inhibition against all tested bacteria and fungi.

CONCLUSION

This study showed the importance of the bioactivities (antioxidant, antimicrobial, and safety potential) of EOs of the plant species TC, RO, and TA used in traditional medicine.

[Drug-induced vasculitis]

INTRODUCTION

Drug-induced vasculitis is reported in almost 10-20 % of vasculitis. Several drugs may be incriminated in their occurrence. Our study aimed to study the epidemiological, clinical, histopathological and evolutionary characteristics of drug-indced vasculitis from a series of cases and to specify the different drugs involved.

METHODS

We conducted a retrospective study during the period from January 2006 to December 2015 from the cases notified to the regional pharmacovigilance center of Sousse, Tunisia. The diagnosis was established according to the criteria proposed by the group of the American college of rheumatology (ACR).

RESULTS

Our study included thirteen cases of drug-induced vasculitis over a ten-year period, with an mean incidence of 1.3 new cases per year. Mean age of patients was 40.84 years. The mean delay from the treatment onset was 14.46 days with extremes ranging from 5 days to six weeks. Most patients had pure skin involvement. Association with other extracutaneous complaints was present in five cases. Cutaneous biopsy was performed in all patients showing a pathological pattern of leukocytoclastic vasculitis, associated with fibrinoid necrosis, extravasation of red blood cells and allergic capillaritis. The outcome was favorable for all patients. The offending drugs in our series were amoxicillin, pristinamycin, rifampicin, fluconazole, metformin, glimepiride, phenobarbital, gabapentin, fenofibrate, ibuprofen, allopurinol, rituximab and tinzaparin.

CONCLUSION

Anamnestic, clinical, biological and histopathological findings allow the early recognition of drug-induced vasculitis. Adequate treatment prevents systemic spreading and a worse prognosis.

An embedded implementation based on adaptive filter bank for brain-computer interface systems

BACKGROUND

Brain-computer interface (BCI) is a new communication pathway for users with neurological deficiencies. The implementation of a BCI system requires complex electroencephalography (EEG) signal processing including filtering, feature extraction and classification algorithms. Most of current BCI systems are implemented on personal computers. Therefore, there is a great interest in implementing BCI on embedded platforms to meet system specifications in terms of time response, cost effectiveness, power consumption, and accuracy.

NEW-METHOD

This article presents an embedded-BCI (EBCI) system based on a Stratix-IV field programmable gate array. The proposed system relays on the weighted overlap-add (WOLA) algorithm to perform dynamic filtering of EEG-signals by analyzing the event-related desynchronization/synchronization (ERD/ERS). The EEG-signals are classified, using the linear discriminant analysis algorithm, based on their spatial features.

RESULTS

The proposed system performs fast classification within a time delay of 0.430 s/trial, achieving an average accuracy of 76.80% according to an offline approach and 80.25% using our own recording. The estimated power consumption of the prototype is approximately 0.7 W.

COMPARISON-WITH-EXISTING-METHOD

Results show that the proposed EBCI system reduces the overall classification error rate for the three datasets of the BCI-competition by 5% compared to other similar implementations. Moreover, experiment shows that the proposed system maintains a high accuracy rate with a short processing time, a low power consumption, and a low cost.

CONCLUSIONS

Performing dynamic filtering of EEG-signals using WOLA increases the recognition rate of ERD/ERS patterns of motor imagery brain activity. This approach allows to develop a complete prototype of a EBCI system that achieves excellent accuracy rates.