Commensal symbiosis between agglutinated polychaetes and sulfate-reducing bacteria.

Pendant bioconstructions occur within submerged caves in the Plemmirio Marine Protected Area in SE Sicily, Italy. These rigid structures, here termed biostalactites, were synsedimentarily lithified by clotted-peloidal microbial carbonate that has a high bacterial lipid biomarker content with abundant compounds derived from sulfate-reducing bacteria. The main framework builders are polychaete serpulid worms, mainly Protula with subordinate Semivermilia and Josephella. These polychaetes have lamellar and/or fibrillar wall structure. In contrast, small agglutinated terebellid tubes, which are a minor component of the biostalactites, are discontinuous and irregular with a peloidal micritic microfabric. The peloids, formed by bacterial sulfate reduction, appear to have been utilized by terebellids to construct tubes in an environment where other particulate sediment is scarce. We suggest that the bacteria obtained food from the worms in the form of fecal material and/or from the decaying tissue of surrounding organisms and that the worms obtained peloidal micrite with which to construct their tubes, either as grains and/or as tube encompassing biofilm. Peloidal worm tubes have rarely been reported in the recent but closely resemble examples in the geological record that extend back at least to the early Carboniferous. This suggests a long-lived commensal relationship between some polychaete worms and heterotrophic, especially sulfate-reducing, bacteria.

Surgery of differentiated thyroid carcinoma, lymph node metastases and locoregional recurrence.

Surgery of differentiated thyroid carcinoma is burdened with risk factors that significantly impact on prognosis, as age at diagnosis and tumor stage. Problems involved concern the extent of surgical resection and the indication for regional lymphadenectomy. As for the former, the most popular approach is total thyroidectomy "on principle" with neck lymphadenectomy. Lobectomy may represent an alternative to total thyroidectomy in low risk patients with unifocal papillary carcinoma 1 cm or less in size, or minimally invasive follicular carcinoma. As for lymphadenectomy, most authors do not agree with surgery "on principle" but rather "of necessity", that is, in presence of clinically evident lymphadenopathy and neck lymphadenectomy is the preferred surgical strategy. In most cases surgery is the treatment of choice of locoregional recurrence. Careful preoperative work-up and accurate surgical procedure are mandatory.

[Postoperative intravenous analgesia]. / Analgesia postoperatoria endovenosa.

The authors report the results of two clinical studies on postoperative pain relief with PCA. In the first clinical study 44 patients, undergoing gynecologic surgery, were assigned at random to two groups. The first was treated by PCA (infusor Baxter) with morphine i.v. (basal bolus 0.05 mg/kg, loading doses 1 mg every 6-15'), the second with 10 mg morphine i.m. at the end of surgery and then on demand with a lock-out of 6h at least. In the 2nd clinical study, 40 elder patients submitted to orthopedic surgery, were assigned at random to two groups treated with PCA (morphine i.v., basal bolus 0.07 mg/kg, bolus PCA 0.007 mg/kg lock-out 15') and with continuous infusion (i.c.) (basal bolus 0.07 mg/kg, i.c. 0.02 mg/kg/h). Our data were analyzed with Student's "t" unpaired test and showed lower doses of the drug in the groups PCA (1st study PCA 25.98 mg/48h, i.m. 45.45 mg/48h, 2nd study PCA 0.155 mg/kg/12h, i.c. 0.311 mg/kg/12h) and lower rate of side effects in the same groups. Side effects were well controlled using symptomatic drugs. We proposed to our patients, at the end of observation, a questionnaire about general conditions, sleep, pain evaluation using a descriptive scale and retrospective evaluation. Patients and nurses agree PCA. Nursing staff expressed a positive opinion and patients said they benefitted from PCA. As reported, PCA appears from our results, valid and safe in postoperative pain relief.