The practical assessment and management of bladder outflow obstruction

The initial management of bladder outflow obstruction typically related to benign prostatic hyperplasia (BPH) falls to a large extent within the remit of general practice. Referral onwards to secondary care typically arises following the failure to respond to conservative measures or when complications have supervened; the most significant of which is urinary retention. In the hospital setting, anaesthesia, constipation and immobility are the common precipitants. What follows is a practical guide to the management of these situations and provides an overview of the conservative, medical, minimally invasive and surgical treatments available.     

Synthesis of 3-(3-pyridyl)- and 3-(3-benzo[b]thienyl)-D-alanine

The DL-arylamino acid ethyl ester derivatives of β-(3-pyridyl)-DL-alanine, and β-(3-benzo[b]thienyl)-DL-alanine were synthesized by diethyl acetamidomalonate condensation with the respective arylmethyl halides followed by partial hydrolysis to the monoethyl ester and decarboxylation. Each derivative was enzymatically resolved to a separable mixture of the corresponding N-acetyl-L-amino acid and the unchanged D amino acid derivative. Acidic hydrolysis of the latter gave the corresponding D-amino acid, the optical purity of which was established by HPLC analysis of the 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate (GITC) derivative. The free D amino acids were converted to D-BOC derivatives by reaction with di-tert-butyldicarbonate in tert-butyl alcohol, water and sodium hydroxide.     

Species Differences in 2,3,7,8-Tetrachlorodibenzo-p-dioxin Toxicity and Biotransformation in Fish

Species Differences in 2,3,7,8-Tetrachlorodibenzo-p-dioxin Toxicityand Biotransformation in Fish. KLEEMAN, J. M., OLSON, J. R.,AND PETERSON, R. E. (1988). Fundam. Appl. Toxicol 10, 206-213.Rainbow trout, yellow perch, carp, bluegill, largemouth bass,and bullhead were treated with graded doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD; 1, 5, 25, or 125 µg/ kg) or vehicle, ip. The lethalpotency of TCDD tended to be greater in yellow perch, carp,and bullhead than in the other three species (LD50 80 days post-treatment,3-5 versus 10-16 µg/kg, respectively). All species treatedwith the highest dose of TCDD (125 µg/kg) displayed alatency period of 1-4 weeks prior to death; longer latency periodswere produced by lower lethal doses. Effects of TCDD treatmenton body weight were both species-dependent and dose-dependent.Fin necrosis was observed in all fish species; however, cutaneoushemorrhage was observed only in TCDD-treated perch, carp, andbluegill, and cutaneous hyperpigmentation only in TCDD-treatedcarp and largemouth bass. Gallbladder bile was analyzed forTCDD and its metabolites 7 days after fish were injected with[¹⁴C]TCDD (60 µg/kg, ip). At least three TCDD metabolitesin addition to the parent compound were found in the gallbladderbile of all six species. In addition, the retention time ofthe major biliary TCDD metabolite (determined by HPLC) was similarin all species except yellow perch. ß-Glucuronidasetreatment of the bile from largemouth bass and bluegill suggestedthat at least two of the TCDD metabolites were glucuronide conjugates.Thus, species differences exist in the lethal potency, signsof overt toxicity, and biotransformation of TCDD among freshwaterfish.