Thermal Reactions of Four-Membered Rings Containing Silicon or Germanium

The synthesis of E- and Z-1,1,2,3-tetramethylsilacyclobutanes is described. Pyrolysis of either isomer at 398.2 °C provides the same products but in different amounts: propene, E- and Z-2-butene, allylethyldimethylsilane, dimethylpropylsilane, the respective geometric isomers, 1,1,2,3,3-pentamethyl-1,3-disilacyclobutane, 1,1, l-ethyldimethyl-2,2,2-vinyldimethyl-disilane and E- and Z-1,1,2,3,3,4-hexamethyl-1,3-disilacyclobutane. Mechanisms involving di- and trimethylsilenes are described for disilane formation and rate constants of the elementary steps for the fragmentation reactions are reported. Photochemically generated dimethylsilylene in the hydrocarbon solution inserts into the cyclic Ge-C or Si-C bonds of 1,1-dimethylgerma- or silacyclobutane to produce 1-germa-2-sila- or 1,2-disilacyclopentane. The relative reactivities of 1,1-dimethylgerma- and silacyclobutanes toward the dimethylsilylene have been determined. The carbenoid resulting from the cuprous chloride catalyzed decomposition of diazomethane at 25 °C in cyclohexane reacts with 1,1-dimethylgermacyclobutane to give, surprisingly 1,1,5,5-tetramethyl-1,5-digermacyclooctane as the major product. The reactions of the carbenoid with 1,1-dimethylsilacyclobutane are described. The kinetics of gas phase thermal decomposition of 1,1-dimethylgermacyclobutane has been studied over the temperature range, 684 - 751 K at pressures near 14 Torr. The Arrhenius parameters for the formation of ethylene are k_1 (s^-1) = 10^(14.6 ± 0.3) exp (62.7 ± 2.9 kcal mol^-1/RT) and those for the formation of propene and cyclopropane are k_2 (s^-1) = 10^(14.0 ± 0.1 ) exp (60.4 ± 2.8 kcal mol^-1/RT). Static gas phase pyrolyses of 1,1-dimethyl-lsilacyclobutene, DMSCB, in the presence of a variety of alkenes and alkynes at 260 - 365 °C have been studied. Our experimental results suggest that under these conditions the DMSCB ring opens to 1,1-dimethyl-l-silabutadiene, which either recyclizes to DMSCB or reacts with alkenes or alkynes in competing 4 + 2 and 2 + 2 cycloadditions

Development of an Indirect ELISA Using Different Fragments of Recombinant Ncgra7 for Detection of Neospora caninum Infection in Cattle and Water Buffalo

Background: Dense granules are immunodominant proteins for the standardi-zation of immunodiagnostic procedures to detect neosporosis. In the presented study different fragment of a dense-granule protein was evaluated for serodiagno-sis of Neospora caninum in cattle and water buffalo. Methods:NcGRA7, from N. caninum tachyzoites was amplified. PCR product and pMAL-c2X plasmid were digested with EcoR1 restriction enzyme and ex-pressed in Escherichia coli to evaluate its competence for detection of anti- N. cani-num antibodies with ELISA in comparison with commercial IDEXX ELISA. Fur-thermore, 230 sera of presumably healthy cattle and water buffaloes (108 cattle and 122 water buffaloes) were analyzed by both tests to determine the agreement of these two procedures. Results:Sensitivities and specificities of NcGRA7-based ELISA were 94.64% and 90.38% respectively using sera of cattle, but were 98.57% and 86.54% in the case of buffaloes respectively. A good correlation between the results of IDEXX ELISA and ELISA based on recombinant NcGRA7 for detecting N. caninum an-tibodies was appeared. Analyzing by Mc Nemar´s showed that NcGRA7-based ELISA has acceptable capability to differentiate the positive results in comparison with IDEXX ELISA. Conclusion:NcGRA7-based ELISA considering utilized new fragment of ge-nomic DNA is a good tool for serodiagnosis of anti- N. caninum antibodies for screening and epidemiological purposes on cattle herd and water buffaloes as well

Pure testicular choriocarcinoma with gastrointestinal metastasis and paraneoplastic symptoms: a case report

Abstract Background Pure testicular choriocarcinoma is a rare type of non-seminomatous germ cell tumor extremely poor prognostic with the tendency to bleed at the metastatic site. At the time of the diagnosis, 70% of patients have metastatic lesions. Depending on the site of the metastasis, symptoms vary. Gastrointestinal involvement is seen in less than 5% of cases, mostly in the duodenum. Case presentation We present a 47 years old male with testicular choriocarcinoma involving the jejunum, lung, liver, and kidney presenting with acute abdominal pain, melena, and dyspnea with some paraneoplastic symptoms. The patient had increased, severe and constant pain in the right lower quadrant for the previous four days. Additionally, he was complaining of nausea, vomiting, anorexia, and a history of melena for the last 10 days. Dyspnea on exertion, hemoptysis, and dry cough were the symptoms he was suffering from, for almost one year. The patient’s general appearance was pale, ill, and thin with 10 kg of weight loss during the last some months. The computed tomography (CT) scan reported multiple metastatic lesions in both liver lobes and the left kidney. Pathologic study of the samples of small bowel lesions showed metastatic choriocarcinoma. Following the patient had been referred to an oncologist to start the chemotherapy regime. Finally, the patient has expired after 40 days of his first admission. Conclusions Testicular choriocarcinoma is a rare but fatal malignancy among young men. Gastrointestinal metastases are infrequent involvement represented by melena and acute abdominal pain, obstruction, and mass. Physicians should consider it as a differential diagnosis for acute abdomen and gastrointestinal bleeding causation

The Cataleptic, Asymmetric, Analgesic, and Brain Biochemical Effects of Parkinson’s Disease Can Be Affected by Toxoplasma gondii Infection

Purpose. Parkinson’s disease (PD) is a neurodegenerative disorder with progressive motor defects. Therefore, the aim of the present investigation was to examine whether catalepsy, asymmetry, and nociceptive behaviors; the Nissl-body and neuron distribution; brain-derived neurotrophic factor (BDNF); malondialdehyde (MDA); total antioxidant capacity (TAC) levels; and the percentage of dopamine depletion of striatal neurons in the rat model of Parkinson’s disease (PD) can be affected by Toxoplasma gondii (TG) infection. Methods. Fifty rats were divided into five groups: control (intact rats), sham (rats which received an intrastriatal injection of artificial cerebrospinal fluid (ACSF)), PD control (induction of PD without TG infection), TG control (rats infected by TG without PD induction), and PD infected (third week after PD induction, infection by TG was done). PD was induced by the unilateral intrastriatal microinjection of 6-hydroxydopamine (6-OHDA) and ELISA quantified dopamine, BDNF, MDA, and TAC in the striatum tissue. Cataleptic, asymmetrical, nociceptive, and histological alterations were determined by bar test, elevated body swing test, formalin test, and Nissl-body and neuron counting in the striatal neurons. Results. The results demonstrated that PD could significantly increase the number of biased swings, descent latency time, and nociceptive behavior and decrease the distribution of Nissl-stained neurons compared to the control and sham groups. TG infection significantly improved biased swing, descent latency time, nociceptive behavior, and the Nissl-body distribution in striatal neurons in comparison to the PD control group. The striatal level of BDNF in the PD-infected and TG control groups significantly increased relative to the PD control group. The striatal MDA was significantly higher in the PD control than other groups, while striatal TAC was significantly lower in the PD control than other groups. Conclusions. The current study indicates that TG infection could improve the cataleptic, asymmetric, nociceptive and behaviors; the level of striatal dopamine release; BDNF levels; TAC; and MDA in PD rats

Study on Theileria lestoquardiAntigens as Potential Vaccine Candidates

Theileria lestoquardi is the causative agent of malignant theileriosis of sheep and goats, causing morbidity and mortality in these animals worldwide. Western blot analysis based on T. lestoquardi schizont antigens was carried out using sera collected from Iranian sheep, which had been immunized with T. lestoquardi schizont-infected cells. The results of Western blot analysis demonstrated that schizont-immunized animals produced antibodies reacting with protein bands at 73, 42, 20, 14, and 12 kDa. Comparison of the results of the current Western blotting test with earlier studies of Theileria spp. revealed two immunogenic schizont proteins with molecular weights of 73 and 42 kDa shared between T. annulata and T. lestoquardi. Two other proteins with molecular weights of 14 and 12 kDa have not been previously found in other Theileria species. Our results suggest that the 73-kDa protein could be a potential vaccine candidate and that the 14- and 12-kDa proteins could be considered as diagnostic antigens

Investigation of 6-[¹⁸F]-Fluoromaltose as a Novel PET Tracer for Imaging Bacterial Infection

<div><p></p><p>Despite advances in the field of nuclear medicine, the imaging of bacterial infections has remained a challenge. The existing reagents suffer from poor sensitivity and specificity. In this study we investigate the potential of a novel PET (positron emission tomography) tracer that overcomes these limitations.</p><p>Methods</p><p>6-[¹⁸F]-fluoromaltose was synthesized. Its behavior <i>in vitro</i> was evaluated in bacterial and mammalian cultures. Detailed pharmacokinetic and biodistribution profiles for the tracer were obtained from a murine model.</p><p>Results</p><p>6-[¹⁸F]-fluoromaltose is taken up by multiple strains of pathogenic bacteria. It is not taken up by mammalian cancer cell lines. 6-[¹⁸F]-fluoromaltose is retained in infected muscles in a murine model of bacterial myositis. It does not accumulate in inflamed tissue.</p><p>Conclusion</p><p>We have shown that 6-[¹⁸F]-fluoromaltose can be used to image bacterial infection <i>in vivo</i> with high specificity. We believe that this class of agents will have a significant impact on the clinical management of patients.</p></div