Search

The taxonomic identification of organisms based on the amplification of specific genetic markers (metabarcoding) implicitly requires adequate discriminatory information and taxonomic coverage of environmental DNA sequences in taxonomic databases. These requirements were quantitatively examined by comparing the determination of cyanobacteria and microalgae obtained by metabarcoding and light microscopy. We used planktic and biofilm samples collected in 37 lakes and 22 rivers across the Alpine region. We focused on two of the most used and best represented genetic markers in the reference databases, namely the 16S rRNA and 18S rRNA genes. A sequence gap analysis using blastn showed that, in the identity range of 99-100%, approximately 30% (plankton) and 60% (biofilm) of the sequences did not find any close counterpart in the reference databases (NCBI GenBank). Similarly, a taxonomic gap analysis showed that approximately 50% of the cyanobacterial and eukaryotic microalgal species identified by light microscopy were not represented in the reference databases. In both cases, the magnitude of the gaps differed between the major taxonomic groups. Even considering the species determined under the microscope and represented in the reference databases, 22% and 26% were still not included in the results obtained by the blastn at percentage levels of identity ≥95% and ≥97%, respectively. The main causes were the absence of matching sequences due to amplification and/or sequencing failure and potential misidentification in the microscopy step. Our results quantitatively demonstrated that in metabarcoding the main obstacles in the classification of 16S rRNA and 18S rRNA sequences and interpretation of high-throughput sequencing biomonitoring data were due to the existence of important gaps in the taxonomic completeness of the reference databases and the short length of reads. The study focused on the Alpine region, but the extent of the gaps could be much greater in other less investigated geographic areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

In reporting 11 cases of Spigelian hernia observed, the Authors describe pathological findings of this rare disease. Aetiopathogenesis as well as indication for surgery and surgical technique are stressed.

The authors report their experience in relation to a series of 12 cases of hematoma of the rectus abdominis (ER) observed over the course of 13 years at the 2nd Division of General Surgery at Vicenza Hospital: 7 were spontaneous, 2 post-traumatic, 1 occurred during anti-coagulant treatment, 1 in a patient with altered coagulation levels due to liver cirrhosis, and 1 was post-operative. Clinical symptoms were sub-acute in 8 cases and were characterised by abdominal pain in all cases, the appearance of an abdominal mass in 4 cases and by ecchymosis in 3 cases. Symptoms were acute in 4 cases with signs of impaired general conditions and anemia. Echography made a decisive contribution to the diagnosis in this pathology and, based on the author's experience, when it was used it prevented the use of surgery. Computerised axial tomography, although it contributed a few precise findings to the diagnosis of ER, was rarely useful. Eight patients were operated: 2 due to collapse and anemia, 4 due to failure to identify the disease, 1 due to persistence of the parietal mass, and 1 due to infection of the hematoma. In the 4 cases which were not operated, the course of the disease was more favourable. The sole death was an elderly cardiopathic patient due to postoperative complications following general surgery. The most suitable therapeutic approach, in those cases where an accurate diagnosis of ER has been made, is to refrain from any form of treatment and to monitor symptoms until they resolve, which will occur spontaneously after 20-30 days.(ABSTRACT TRUNCATED AT 250 WORDS)

A case of primary duodenal adenocarcinoma recently observed gives the Authors the chance to review the literature. Diagnosis is often delayed because symptomatology is usually vague and non specific, a fact that is even more in contrast with diagnostic techniques, which, on the contrary, are handy and easily performed (endoscopy, duodenography). Surgical resection is the only proposable treatment while no local and distant diffusion has yet showed, otherwise the operation is limited to a digestive and/or biliary derivation. Anyhow, prognosis remains severe.

The study was carried out on 100 patients over 70 suffering from rectal cancer. The operative death-rate resulted higher in wider resections than in more limited ones, though the former showed a lower incidence of relapse and higher survival rates. Operative death-rate was more strictly related to the presence of cardiorespiratory alterations than to age per se. As a consequence, in Authors' opinion, surgical therapy is not to be completely rejected in old-aged patients; on the contrary it should be discussed according to the patient status. With the increase of the population mean age rectal cancer diagnosis in old patients has become more frequent; nowadays, improvements in anaesthesia and reanimation practice allow a considerable decrease in surgical risks with a corresponding increased possibility of a radical surgical therapy.