ABSTRACT
Chronic pruritus is a major and distressing symptom of many diseases of dermatological, neurological, psychogenic or systemic origin. This chronic itch could be a presenting sign of malignancy; therefore, paraneoplastic pruritus has also been associated with neuroendocrine tumors (NETs). This article focuses on a patient presenting with chronic pruritus for the past 12 months and who received numerous treatment schemes with very poor clinical improvement, that presented in the hospital for worsening of the chronic pruritus associated with skin rash and significant weight loss (approximately 6 kg over a 2-month period). The laboratory tests showed iron deficiency anemia, eosinophilia and negative tumor markers. In order to investigate the hypoanabolic and anemic syndromes, upper gastrointestinal endoscopy and colonoscopy, which showed no lesions or tumors, were employed. Skin biopsy was performed and antihistaminic and local steroid treatment was initiated. The patient's status worsened within a week and the patient was started on systemic steroid treatment with poor results. Computer tomography was performed to identify any tumor(s) located either in the pelvis or abdomen. A lesion was found in the terminal ileum, identified as a hypervascularized associating bulky lymphadenopathy. The patient was transferred to the surgical ward where right hemicolectomy with manual ileotransverse anastomosis L-L was performed. The histopathological result confirmed NET G2. The patient clinically improved, the skin lesions resolved and the itchiness disappeared. The general status improved significantly. NET G2 diagnosing was possible due to the atypic paraneoplastic sign: chronic pruritus. This case study highlights the association between itch and malignancy and presents an atypical way of NET presentation when all tumor markers remain negative.
ABSTRACT
The main aim of the paper was to simulate the drug release by a multifractal theoretical model, as a valuable method to assess the drug release mechanism. To do this, drug delivery films were prepared by mixing poly(vinyl alcohol boric acid) (PVAB) and diclofenac (DCF) sodium salt drug in different mass ratios from 90/10 to 70/30, in order to obtain drug delivery systems with different releasing rates. The different drug content of the three systems was confirmed by energy-dispersive spectroscopy (EDAX) analysis, and the encapsulation particularities were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and polarized optical microscopy (POM) techniques. The ability of the PVAB matrix to anchor the DCF was assessed by Fourier transform infrared (FTIR) spectroscopy. The in vitro release of the diclofenac sodium salt from the formulations was investigated in biomimetic conditions (pH = 7.4 and 37°C) by UV-Vis spectroscopy, measuring the absorbance of the drug at 275 nm and fitting the results on a previously drawn calibration curve. An estimation of the drug release kinetics was performed by fitting three traditional mathematical models on experimental release data. Further, the drug delivery was simulated by the fractal theory of motion, in which the release dynamics of the polymer-drug complex system is described through various Riccati-type "regimes." To explain such dynamics involved multifractal self-modulation in the form of period doubling, quasiperiodicity, intermittency, etc., as well as multifractal self-modulation of network type. Standard release dynamics were explained by multifractal behaviors of temporary kink type. The good correlation between the traditional mathematical models and the new proposed theoretical model demonstrated the validity of the multifractal model for the investigation of the drug release.