Research developments in carbon materials based sensors for determination of hormones

Various carbon-based sensors (graphene, carbon nanotubes, graphite, pencil graphite, glassy carbon, etc.) have distinctive behavior and a broad range of importance for identifying sex hormones like estriol, estradiol, estrone, progesterone, and testosterone. The current review emphasizes voltammetric, amperometric, and electrochemical impedance spectroscopic methods for detecting some of these hormones. The existence, structural aspects, nature, and biological importance of each hormone were analyzed in detail and their analysis with different electroanalytical methods was considered. Unique methodologies and innovations of electrochemical sensors for hormones based on carbon materials modified by different agents were examined. In this review, the interaction among various sensor materials and analytes in different supporting electrolyte media is premeditated. The most important significances of the electroanalytical methodologies were discussed based on sensor selectivity, sensitivity, stability, the limit of detection, repeatability, and reproducibility

Research developments in carbon materials based sensors for determination of hormones

Various carbon-based sensors (graphene, carbon nanotubes, graphite, pencil graphite, glassy carbon, etc.) have distinctive behavior and a broad range of importance for identifying sex hormones like estriol, estradiol, estrone, progesterone, and testosterone. The current review emphasizes voltammetric, amperometric, and electrochemical impedance spectroscopic methods for detecting some of these hormones. The existence, structural aspects, nature, and biological importance of each hormone were analyzed in detail and their analysis with different electroanalytical methods was considered. Unique methodologies and innovations of electrochemical sensors for hormones based on carbon materials modified by different agents were examined. In this review, the interaction among various sensor materials and analytes in different supporting electrolyte media is premeditated. The most important significances of the electroanalytical methodologies were discussed based on sensor selectivity, sensitivity, stability, the limit of detection, repeatability, and reproducibility

Electrochemical analysis of indigo carmine using polyarginine modified carbon paste electrode

Suitable electrocatalytic method is established for the selective determination of indigo carmine (IC) at polyarginine modified carbon paste electrode (PAMCPE). Surface morphological study of bare carbon paste electrode (CPE) and PAMPCE is done by field emission scanning electron microscopy (FESEM). The influence of different parameters such as IC concentration, solution pH and potential scan rate on the electrode responses is studied using cyclic and differential pulse voltammetry techniques. The prepared PAMCPE shows better electrochemical response towards IC than CPE. No interference is noticed at simultaneous presence of IC and riboflavin (RF) in the solution. The electrocatalytic current of IC at PAMPCE is varied linearly with its concentration in two separate ranges, from 2×10-7 to 10-6 M, and 1.5×10-6 to 3.5×10-6 M. Limits of detection (LOD) and quantification (LOQ) are determined as 2.53×10-8 and 8.43×10-8 M, respectively. The developed PAMCPE is showing successful reproducibility and stability. It is also found sensitive and reliable for trace amounts of IC in some real water and food samples. Since preparation of PAMCPE sensor is simple and easy, it could become a part of the standard method for determination of IC in real samples

Poly (DL-valine) electro-polymerized carbon nanotube paste sensor for determination of antihistamine drug cetirizine

Poly (DL-valine) modified multiwalled carbon nanotube paste sensor (PVLMCNTPS) was prepared by electro-polymerization route. PVLMCNTPS and bare multiwalled carbon nanotube paste sensor (BMCNTPS) morphologies and sensing properties for cetirizine (CTZ) were confirmed through a field emission scanning electron microscope (FE-SEM) and electrochemical studies, respectively. In contrast to BMCNTPS, PVLMCNTPS surface composite creates an electrocatalytic impact on the oxidation of CTZ. PVLMCNTPS properties were optimized using parameters such as accumulation time, number of polymerization cycles, solution pH, and scan rate. The optimized PVLMCNTPS was applied for the determination of cetirizine in 0.1 M phosphate buffer solution (PBS) of pH 7.0, using cyclic voltammetry (CV). It is shown that PVLMCNTPS provided analytical linearity from 2.0 to 80 µM, with a detection limit of 0.11 µM for CTZ determination. PVLMCNTPS is found highly selective for CTZ in presence of some interfering organic molecules. The stable and selective PVLMCNTPS was applied for CTZ determination in pharmaceutical pills with satisfactory results

Small cell lung carcinoma with three paraneoplastic syndromes in one patient

SESSION TITLE: Monday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: This is a case of patient who was diagnosed with Small Cell Lung Carcinoma(SCLC)after presenting with symptoms of Dermatomyositis(DM), SIADH and Lambert–Eaton myasthenic(LEMS)syndrome CASE PRESENTATION: Patient initially presented to the clinic with erythematous patches scattered on the trunk, extremities, and scalp associated with pain, itchiness and hair loss for two months. Biopsy from rash showed perifollicular and mild superficial perivascular inflammation. The patient was treated for viral exanthem with steroids. Patient subsequently presented to the hospital with worsening pruritic patches on scalp and entire body and periorbital edema. This was associated with weakness and generalized malaise. The weakness and pain were worse with neck and shoulder movements and the weakness improved on exertion. Other symptoms were productive cough, rhinorrhea, nasal congestion and sore throat for a month associated with 20 pounds weight loss. Physical exam showed decreased breath sounds in the left upper and middle field.No lower extremity swelling.Skin findings were violaceous edematous periorbital erythema(heliotrope rash), erythema of neck, upper chest, and entire back, erythematous slightly scaly plaques overlying MCPs and PIPs(Gottron\u27s papules). Labs showed CPK of 868, Aldolase of 8.9, serum sodium of 115(Serum osmolality 248, Urine osmolality 497, TSH 1.7, random cortisol 20.7)and ANA(1:320)was positive. Chest x-ray showed left upper lobe mass. CT chest showed malignant process arising from the left upper lobe and to the mediastinum. She underwent bronchoscopy with FNA and endobronchial biopsy which showed SCLC. DISCUSSION: Paraneoplastic syndromes occur in approximately 10% of patients with lung cancer(1). SIADH occurs in 15% of SCLC patients. LEMS is present in approximately 1% to 3% of patients with SCLC. Off all cases of DM only 5.9% have lung cancer. In some cases these syndromes can be presenting sign of cancer. The early recognition of paraneoplastic syndromes may contribute to the detection of a highly treatable, early-stage tumor. At other times, the syndromes may occur late in the course of disease or may appear as the first sign of recurrence DM is associated with poor prognosis and improved SCLC tumor survival are seen in patients with LEMS(2). Management of hyponatremia is very important as it is associated with a poor prognosis regardless of an extensive or limited stage. SCLC patients with serum sodium less than 129 mmol/l had a median survival of 8.63 months compared to 13.6 months in patients with normal sodium, and the degree of hyponatremia is a significant predictor for prognosis(3). CONCLUSIONS: SCLC is associated with large number of paraneoplastic syndromes which can also be the initial presentation in some cases. Ability to identify these syndromes especially in high risk population can lead to early diagnosis and might carry a better prognosis in some patients

Successful management of peripapillary choroidal neovascular membrane secondary to idiopathic intracranial hypertension with intravitreal ranibizumab

Idiopathic intracranial hypertension (IIH) is a common cause of papilledema in young females and causes headache with transient visual loss. Severe visual loss occurs due to optic atrophy or peripapillary choroidal neovascular membrane (PCNVM). PCNVM in IIH has an incidence of 0.5% with a benign course in the majority of patients. Intravitreal Anti-vascular endothelial growth factor agents have anecdotally been used to manage these patients, with complete resolution reported in all cases after a single injection. Our case of IIH-associated PCNVM was treated with three injections of intravitreal ranibizumab with no recurrence at 6-month follow-up