Laparoscopic Drainage as First Line Treatment for Complex Pyogenic Liver Abscesses.

UNLABELLED: Background/aims: Pyogenic liver abscess (PLA) is a rare but potentially fatal condition if untreated. In available retrospective series successful rate of per- cutaneous drainage (PD) on large multiloculated PLA, that has been definited "complex". In this observation- al study, we report the experience of our Institution in performing laparoscopic drainage of complex liver ab- scess over a 5-years period as first line treatment for selected cases of PLA. Methodology: All cases of large multiloculated liver abscesses admitted to the General and Hepatobiliary Surgery of "Loreto Nuovo" Hospital Naples, Italy over the last 5-years period were treated by laparoscopic drainage and his clinicopathological variables were retrospectively reviewed. RESULTS: Ten patients with large multiloculated liver abscess has been admitted and treated by only laparoscopic drainage without need of other perioperative procedures. Mean age was 51.5 years (range 41-75y); average hospital stay was 4.6 days (range 2-6 days) and major postoperative morbidity or deaths were not registered. Successful rate was 100% with no recurrence at 2-years follow up (range 12/38 months). CONCLUSIONS: Laparoscopic drainage seems to be a safe and reproducible mini-invasive treatment of complex liver abscesses and to offer advantages over percutaneous and surgical open approach.

Cloning and heterologous expression of three type II PKS gene clusters from Streptomyces bottropensis.

Mensacarcin is a potent cytotoxic agent isolated from Streptomyces bottropensis. It possesses a high content of oxygen atoms and two epoxide groups, and shows cytostatic and cytotoxic activity comparable to that of doxorubicin, a widely used drug for antitumor therapy. Another natural compound, rishirilide A, was also isolated from the fermentation broth of S. bottropensis. Screening a cosmid library of S. bottropensis with minimal PKS-gene-specific primers revealed the presence of three different type II polyketide synthase (PKS) gene clusters in this strain: the msn cluster (mensacarcin biosynthesis), the rsl cluster (rishirilide biosynthesis), and the mec cluster (putative spore pigment biosynthesis). Interestingly, luciferase-like oxygenases, which are very rare in Streptomyces species, are enriched in both the msn cluster and the rsl cluster. Three cosmids, cos2 (containing the major part of the msn cluster), cos3 (harboring the mec cluster), and cos4 (spanning probably the whole rsl cluster) were introduced into the general heterologous host Streptomyces albus by intergeneric conjugation. Expression of cos2 and cos4 in S. albus led to the production of didesmethylmensacarcin (DDMM, a precursor of mensacarcin) and the production of rishirilide A and B (a precursor of rishirilide A), respectively. However, no product was detected from the expression of cos3. In addition, based on the results of isotope-feeding experiments in S. bottropensis, a putative biosynthesis pathway for mensacarcin is proposed.