Successful laparoscope-assisted orchiectomy in three cryptorchid sheep.

Three adult Corriedale cryptorchid sheep were subjected to laparoscope-assisted orchiectomy of the retained testicles. One (n = 2) or both (n = 1) the testicles were missing in their scrotal sac and inguinal regions. Ultrasonography was used to locate the retained testicles and their distance from the abdominal surface. The animals were restrained in dorsal recumbency and Trendlenburg posture under lumbosacral epidural anaesthesia using 2% lignocaine hydrochloride. Two laparoscopic ports were created in the caudal abdomen adjacent to the retained testicles. They were identified by their ovoid shape, white glistening surface (Tunica albuginea) and typical vasculature. Laparoscope-assisted exteriorization of the testicles after enlarging the ports, ligation of their blood supply and resection of the spermatic cord was performed successfully. The scrotal testes in two rams were then subjected to routine Burdizzoo castration. The laparoscopic port sites healed without complications and all the animals continued to do well subsequently. From this case report, it is concluded that in sheep the laparoscopy; a minimally invasive procedure can confirm abdominal retention of testicle/s and may also be used for their retrieval in a single sitting. Although total laparoscopic procedure is expected to reduce the incision size further but requires advanced laparoscopic instruments and expertise.

Two highly conserved features of bacterial initiator tRNAs license them to pass through distinct checkpoints in translation initiation.

Eubacterial translation initiation involves assembly of tRNAfMet, mRNA, initiation factors (IFs) and 30S ribosome in a 30S pre-initiation complex (30S pre-IC), which rearranges and joins 50S ribosome to form 70S IC. Upon releasing IFs, 70S IC becomes elongation-competent 70S. The direct recruitment of initiator tRNA (tRNAfMet) into the ribosomal P-site, crucial in accurate initiation of translation, is attributed to two conserved features of tRNAfMet: (i) formylation of amino acid attached to it and, (ii) the presence of three consecutive G-C base pairs (3GC base pairs) in the anticodon stem. However, the precise roles of these two conserved features of tRNAfMet during the various steps of initiation remain unclear. Using natural and engineered tRNAs, we show that the 3GC pairs license tRNAfMet transitions from 30S to 70S IC and then to elongation-competent 70S by release of IF3. Of the 3GC pairs, the middle GC pair (G30-C40), or merely G30 (in a specific context) suffices in this role and is essential for the sustenance of Escherichia coli. Furthermore, rescue of formylase deficient E. coli by overproduced tRNAfMet reveals that the feature of formylation licenses initial targeting of tRNAfMet to 30S ribosome