Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology

<p>Abstract</p> <p>Background</p> <p>Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil) and vegetables (jojoba) which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones.</p> <p>Results</p> <p>Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from <it>Rhizopus oryzae </it>was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C), the enzyme concentration (33.34-300 IU/mL), the alcohol/palm stearin molar ratio (3-7 mol/mol) and the substrate concentration (0.06-0.34 g/mL) on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL) a high conversion yield of 98.52% was reached within a reaction time of 2 h.</p> <p>Conclusions</p> <p>Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters.</p

Mounier-Kuhn syndrome and tracheopathia osteoplastica in the same patient with respiratory insufficiency

SummaryMounier-Kuhn syndrome (MKS) or tracheobronchomegaly, and tracheopathia osteoplastica (TO) are rare diseases. MKS is a clinical entity characterized by abnormal dilatation of the trachea and main bronchi. TO is a clinical and pathologic condition characterized by multiple submucosal cartilaginous and osseous nodules lining the upper respiratory tract. Some people with MKS manifest recurrent pneumonia or chronic cough with sputum production, hemoptysis or dyspnea. Occasionally, it is found in asymptomatic individuals. CT scan imaging is the key tool for the diagnosis when showing a dilatation of the trachea and main bronchi. TO is usually benign and asymptomatic, frequently diagnosed incidentally during intubation. Flexible fiberoptic bronchoscopy and laryngoscopy are the key diagnostic tools which typically demonstrate irregular spicules of submucosal bone and cartilage projecting into the tracheobronchial lumen and causing various degrees of airway obstruction. When this aspect is found bronchial biopsy is not mandatory. We report the case of a 26-year-old man with features of both MKS and TO who presented a previous history of productive cough, recurrent pneumonia and dyspnea; admitted for pulmonary infection resulting in a respiratory insufficiency. MKS was diagnosed by CT scan and TO by fiberoptic bronchoscopy. To our knowledge, this is the first time these pathologies are reported in the same patient, and our patient is the second one having MKS who presented with respiratory insufficiency

Synthesis of lipophilic tyrosyl esters derivatives and assessment of their antimicrobial and antileishmania activities

<p>Abstract</p> <p>Background</p> <p>Preparation of tyrosyl lipophilic derivatives was carried out as a response to the food, cosmetic and pharmaceutical industries' increasing demand for new lipophilic antioxidants.</p> <p>Results</p> <p>A large series of tyrosyl esters (<b>TyC₂</b>to <b>TyC_18:1</b>) with increasing lipophilicity was synthesized in a good yield using lipase from <it>Candida antarctica </it>(Novozyme 435). Spectroscopic analyses of purified esters showed that the tyrosol was esterified on the primary hydroxyl group. Synthetized compounds were evaluated for either their antimicrobial activity, by both diffusion well and minimal inhibition concentration (MIC) methods, or their antileishmanial activity against <it>Leishmania major </it>and <it>Leishmania infantum </it>parasite species.</p> <p>Among all the tested compounds, our results showed that only <b>TyC₈</b>, <b>TyC₁₀</b>and <b>TyC₁₂</b>exhibited antibacterial and antileishmanial activities. When MIC and IC₅₀values were plotted against the acyl chain length of each tyrosyl derivative, <b>TyC₁₀</b>showed a parabolic shape with a minimum value. This nonlinear dependency with the increase of the chain length indicates that biological activities are probably associated to the surfactant effectiveness of lipophilic derivatives.</p> <p>Conclusion</p> <p>These results open up potential applications to use medium tyrosyl derivatives surfactants, antioxidants, antimicrobial and antileishmanial compounds in cosmetic, food and pharmaceutical industries.</p

Catamenial pneumothorax revealing diaphragmatic endometriosis: a case report and revue of literature

Catamenial pneumothorax (CP) is a rare entity of spontaneous, recurring pneumothorax in women. We aim to discuss the etiology, clinical course, and surgical treatment of a 42-year-old woman with CP. This patient had a right-sided spontaneous pneumothoraces occurred one week after menses. She had under-gone video-assisted thoracoscopic surgery (VATS) because of a persistent air leak under chest tube. VATS revealed multiple diaphragmatic fenestrations with an upper right nodule. Defects were removed and a large part of the diaphragm was resected. Pleural abrasion was then performed over the diaphragm. Diaphragmatic endometriosis was confirmed by microscopic examination. Medical treatment with GnRH agonists was prescribed, and after recovery, the patient has been symptoms free for 20 months.Keywords: Catamenial pneumothorax, endometriosis, surgical treatmen

Lung Adenocarcinoma with Gingival Metastasis

Gingival metastasis of lung cancer is uncommon. We report the case of an 82-year-old male smoker admitted to the pulmonology department with right pleural effusion. A chest computed tomography (CT) scan showed an invasive right hilar tumour, adherent to the superior vena cava, pulmonary artery, main right bronchus, mediastinal pleura and pericardium with lymphangitic carcinomatosis of the right lung. Pleural biopsy revealed pleural metastasis of pulmonary adenocarcinoma, its primary lung origin being confirmed by immunohistochemistry. One month later, the patient developed an ulcerated polypoid gingival mass. Biopsy of this lesion showed a poorly differentiated carcinoma compatible with metastasis from the lung adenocarcinoma. The patient underwent irradiation of the gingival mass at a dose of 30 Gray, but his condition worsened rapidly and he was not fit for chemotherapy. He received palliative treatment and died 2 months after diagnosis of his metastatic lung cancer

Twin pregnancy with both complete hydatiform mole and coexistent alive fetus: Case report

Twin pregnancy consisting of a complete hydatidiform mole coexisting with a live fetus is a rare condition with an incidence of 1 in 22000 to 1 in 100000 pregnancies. Clinical information is limited and management is difficult due to the risk of pregnancy complications such as fetal death, vaginal bleeding, preeclampsia, hyperthyroidism, and the risk of persistent gestational trophoblastic disease. Thus, the report described about the change of size and implantation site of the molar mass coexisting with a live fetus is rare especially about sonographic findings such as echo patterns. Recently we experienced a case of complete hydatidiform mole with a healthy infant delivered at term

Eukaryotic expression system Pichia pastoris affects the lipase catalytic properties: a monolayer study.

Recombinant DNA methods are being widely used to express proteins in both prokaryotic and eukaryotic cells for both fundamental and applied research purposes. Expressed protein must be well characterized to be sure that it retains the same properties as the native one, especially when expressed protein will be used in the pharmaceutical field. In this aim, interfacial and kinetic properties of native, untagged recombinant and tagged recombinant forms of a pancreatic lipase were compared using the monomolecular film technique. Turkey pancreatic lipase (TPL) was chosen as model. A kinetic study on the dependence of the stereoselectivity of these three forms on the surface pressure was performed using three dicaprin isomers spread in the form of monomolecular films at the air-water interface. The heterologous expression and the N-His-tag extension were found to modify the pressure preference and decrease the catalytic hydrolysis rate of three dicaprin isomers. Besides, the heterologous expression was found to change the TPL regioselectivity without affecting its stereospecificity contrary to the N-tag extension which retained that regioselectivity and changed the stereospecificity at high surface pressures. The study of parameters, termed Recombinant expression Effects on Catalysis (REC), N-Tag Effects on Catalysis (TEC), and N-Tag and Recombinant expression Effects on Catalysis (TREC) showed that the heterologous expression effects on the catalytic properties of the TPL were more deleterious than the presence of an N-terminal tag extension

Successful pregnancy by IVF in a patient with congenital cervical atresia

Congenital cervical atresia and hypoplasia are rare abnormalities that generally require reconstructive or extirpative procedures to relieve outflow tract obstruction. Infertility is a common sequel, and only four previous pregnancies have been reported. We report a case of successful pregnancy after in-vitro fertilization in a 32-year-old patient with congenital cervical atresia diagnosed at the age of 28 years. She was referred to our unit and had a successful pregnancy after in-vitro fertilization. Caesarean section was performed at 38 weeks gestation. A healthy male baby weighing 3650 g was safely delivered