ABSTRACT
Background: In a suicide attempt, a 49-year-old male ingested pesticides. He arrived at the hospital restless and vomiting blue liquid. Case Presentation: The patient was diagnosed with paraquat poisoning at a lethal dose and experienced renal dysfunction during treatment. He underwent continuous hemodiafiltration (CHDF). Hemodialysis was temporarily initiated and found to improve renal function. He was discharged on day 36 in good condition. He remains well with only mild renal impairment and no pulmonary fibrosis, 240 days after the incident. The fatality rate of paraquat poisoning is approximately 80%, regardless of the treatment. Early hemodialysis combined with CHDF within 4 h has been reported to be effective. In this case, CHDF was initiated approximately 3 h after paraquat administration and showed a successful outcome. Conclusion: CHDF should be performed as soon as possible to treat paraquat poisoning.
ABSTRACT
We report a rare case of acquired membranous tracheal stenosis in a patient with anorexia nervosa and a history of self-induced vomiting, but without a history of tracheal intubation or tracheostomy. A 50-year-old woman presented with difficulty in breathing and swallowing, self-expectoration, and impaired consciousness due to acute benzodiazepine intoxication. Bronchoscopic examination was performed after tracheotomy and placement of a tracheostomy tube failed to secure her respiratory tract and ventilation continued to deteriorate. A flap-like membranous structure was identified on the posterior tracheal wall, obstructing the tracheostomy tube. Physical compression of the membranous structure improved ventilation. Bronchoscopic examination is generally recommended prior to performing tracheostomy in patients suspected to have post-intubation tracheal obstruction. Based on our findings, we suggest that these examinations should also be performed in patients with conditions associated with chronic irritation of the respiratory tract, including those with a prolonged history of self-induced vomiting.
ABSTRACT
In the presence of a Pd(0) precatalyst, Pd2(bq)2(nbe)2 or Pd2(dba)3, 1,6-enyne esters were heated in refluxing benzene to give cyclodimers as single regioisomers. On the other hand, the combination of the Pd(0) precatalyst and triphenyl phosphite gave rise to various cycloisomerization products depending on the substitution pattern of the enyne esters. Six-membered ring cycloisomerization products were predominantly obtained from enyne esters bearing methallyl or 2-phenyl-2-propenyl moieties, while other enyne esters afforded normal five-membered ring cycloisomerization products. Intramolecular [2 + 2 + 2] cyclocotrimerization of enediyne esters also proceeded in the presence of the Pd(0) precatalyst and triphenylphosphine to give fused cyclohexadienes.
ABSTRACT
In the presence of 2.5 mol % of [Pd(2)(dba)(3)] (dba=dibenzylideneacetone) and 5 mol % of PPh(3), nearly equimolar amounts of dimethyl nona-2,7-diyne-1,9-dioate derivatives (diyne diesters) and dialkyl acetylenedicarboxylates were allowed to react in toluene at 110 degrees C to afford [2+2+2] cycloadducts in moderate-to-good yields. Similarly, dimethyl trideca-2,7,12-triyne-1,13-dioate derivatives (triyne diesters) were catalytically transformed into phthalic acid ester analogues in excellent yields. To gain insight into the mechanism of these intramolecular alkyne cyclotrimerizations, stoichiometric reactions of [Pd(2)(dba)(3)] with a diyne diester and a triyne diester bearing ether tethers were conducted in acetone at room temperature to furnish an oligomeric bicyclopalladacyclopentadiene and a Pd(0) triyne complex, respectively. The structures of these novel complexes were unequivocally determined by Xray structure analysis. The isolated triyne complex was heated at 50 degrees C or treated with PPh(3) in acetone at room temperature to afford the arene product. Furthermore, the same complex catalyzed the triyne cyclization with or without PPh(3).