Conjunctivitis as a sign of persistent SARS-COV-2 infection? An observational study and report of late symptoms.

PURPOSE: To investigate if symptomatic conjunctivitis during the recovery phase of the disease could be associated to a persistent presence of SARS-CoV-2 in the upper respiratory tract. Secondary end points were to analyze the presence of SARS-CoV-2 in the conjunctiva of ocular symptomatic patients and to record the presence of ocular disturbances at this point of the disease. METHODS: An observational study including consecutive COVID19 patients treated at Humanitas Clinical and Research Hospital who were attending for nasopharyngeal swab to confirm the resolution of SARS-CoV-2 infection and end of isolation. We examined 129 consecutive patients from May to June 2020. The primary end point was to determine if symptomatic conjunctivitis at this point of the disease could be associated to a persistent presence of SARS-CoV-2 in the upper respiratory tract. Secondary end points were to analyze the presence of SARS-CoV-2 in the conjunctiva of ocular symptomatic patients and to record the presence of ocular disturbances at this point of the disease. RESULTS: One hundred twenty eight patients were included, 9.38% had conjunctivitis, none resulted positive to conjunctival PCR swab test, while two of them had positive nasopharyngeal result. Mean time elapsed since the first COVID-19 positive swab to the time of examination was 6 weeks ( ± 3). The only significant association was the presence of conjunctivitis with older age (65.3 ± 12.7 vs 56.7 + 13.5. p = 0.046). Nasopharyngeal swab resulted positive in 22 patients (17.19%). While 88 patients (68.2%) did not have any ocular complain during their COVID19 disease. The 40 patients (31.8%) reporting ocular disturbances complained about: redness (25.43%), tearing (19.53%), burning (18.35%), foreign body sensation (17.18%), itching (15.62%), and discharge (12.5%). CONCLUSION: This study showed that late conjunctivitis cannot be considered as a marker of persistent infection when patients are sent to confirm the resolution of SARS-CoV-2 infection.

[Surgical treatment of acute necrotic-hemorrhagic pancreatitis]. / Il trattamento chirurgico della pancreatite acuta necrotico-emorragica.

The clinical course of an episode of acute pancreatitis varies from a mild transitory form to a severe necrotizing form characterized by multisystem organ failure and mortality in 20% to 40% of cases. Mild pancreatitis does not need specialized treatment, and surgery is necessary only to treat underlying mechanical factors such as gallstones or tumours of papilla of Vater. On the other hand, patients with severe necrotizing pancreatitis need to be identified as early as possible after the onset of symptoms to start intensive care treatment. Patients with infected necrosis, approximately 10 to 20%, must undergo surgical intervention, which consists of an organ-preserving necrosectomy followed by postoperative drainage-lavage or the method of "open abdomen". The Authors report a series of 20 patients operated on for acute necrotizing pancreatitis from 1998 to 2000. They describe the indications and methods of treatment, in particular the additional procedure following necrosectomy.

[Surgical treatment of abdominal aortic aneurysm. Factors affecting mortality and morbidity]. / Il trattamento chirurgico degli aneurismi dell'aorta addominale. Fattori che influenzano mortalità e morbilità.

In this report, based on a 5 year experience, 76 operation were performed electively for intact abdominal aortic aneurysm and 55 were emergency procedure for ruptured aneurysm. Factor affecting mortality and morbidity in the cases are analysed. Three patients died of cardiac causes following elective aneurysm repair, a mortality rate of 3.9%. No patients died of pulmonary causes, renal failure or required dialysis. No patient developed a graft infection, stroke or intestinal ischemia. Mortality rates for surgical repair of ruptured AAA averaged 32% and the principal cause of death is cardiac disease (50%). The second cause is renal failure. Declining of operative mortality for intact aortic aneurysm is related to earlier diagnosis using non invasive methods and correct preoperative study.

The complete genome of the crenarchaeon Sulfolobus solfataricus P2.

The genome of the crenarchaeon Sulfolobus solfataricus P2 contains 2,992,245 bp on a single chromosome and encodes 2,977 proteins and many RNAs. One-third of the encoded proteins have no detectable homologs in other sequenced genomes. Moreover, 40% appear to be archaeal-specific, and only 12% and 2.3% are shared exclusively with bacteria and eukarya, respectively. The genome shows a high level of plasticity with 200 diverse insertion sequence elements, many putative nonautonomous mobile elements, and evidence of integrase-mediated insertion events. There are also long clusters of regularly spaced tandem repeats. Different transfer systems are used for the uptake of inorganic and organic solutes, and a wealth of intracellular and extracellular proteases, sugar, and sulfur metabolizing enzymes are encoded, as well as enzymes of the central metabolic pathways and motility proteins. The major metabolic electron carrier is not NADH as in bacteria and eukarya but probably ferredoxin. The essential components required for DNA replication, DNA repair and recombination, the cell cycle, transcriptional initiation and translation, but not DNA folding, show a strong eukaryal character with many archaeal-specific features. The results illustrate major differences between crenarchaea and euryarchaea, especially for their DNA replication mechanism and cell cycle processes and their translational apparatus.

Silk fibroin: structural implications of a remarkable amino acid sequence.

The amino acid sequence of the heavy chain of Bombyx mori silk fibroin was derived from the gene sequence. The 5,263-residue (391-kDa) polypeptide chain comprises 12 low-complexity "crystalline" domains made up of Gly-X repeats and covering 94% of the sequence; X is Ala in 65%, Ser in 23%, and Tyr in 9% of the repeats. The remainder includes a nonrepetitive 151-residue header sequence, 11 nearly identical copies of a 43-residue spacer sequence, and a 58-residue C-terminal sequence. The header sequence is homologous to the N-terminal sequence of other fibroins with a completely different crystalline region. In Bombyx mori, each crystalline domain is made up of subdomains of approximately 70 residues, which in most cases begin with repeats of the GAGAGS hexapeptide and terminate with the GAAS tetrapeptide. Within the subdomains, the Gly-X alternance is strict, which strongly supports the classic Pauling-Corey model, in which beta-sheets pack on each other in alternating layers of Gly/Gly and X/X contacts. When fitting the actual sequence to that model, we propose that each subdomain forms a beta-strand and each crystalline domain a two-layered beta-sandwich, and we suggest that the beta-sheets may be parallel, rather than antiparallel, as has been assumed up to now.

[Treatment of the abdominal aorta combined with a second surgical procedure]. / Il trattamento dell'aorta addominale combinato con una seconda procedura chirurgica.

The synchronous performance of aortic graft with a second surgical procedure should be avoided because of the risk of subsequent graft infection. The Authors reported the experience of 21 patients who underwent synchronous aortic graft with second surgical procedure. No graft infection occurred and it is concluded that such combined operation may be safer to perform than staged surgery in elderly patients.

A BAC library and paired-PCR approach to mapping and completing the genome sequence of Sulfolobus solfataricus P2.

The original strategy used in the Sulfolobus solfataricus genome project was to sequence non overlapping, or minimally overlapping, cosmid or lambda inserts without constructing a physical map. However, after only about two thirds of the genome sequence was completed, this approach became counter-productive because there was a high sequence bias in the cosmid and lambda libraries. Therefore, a new approach was devised for linking the sequenced regions which may be generally applicable. BAC libraries were constructed and terminal sequences of the clones were determined and used for both end mapping and PCR screening. The PCR approaches included a novel chromosome walking method termed "paired-PCR". 21 gaps were filled by BAC end sequence analyses and 6 gaps were filled by PCR including three large ones by paired-PCR. The complete map revealed that 0.9 Mb remained to be sequenced and 34 BAC clones were selected for walking over small gaps and preparing template libraries for larger ones. It is concluded that an optimal strategy for sequencing microorganism genomes involves construction of a high-resolution physical map by BAC end analyses, PCR screening and paired-PCR chromosome walking after about half the genome sequence has been accumulated.

Fine organization of Bombyx mori fibroin heavy chain gene.

The complete sequence of the Bombyx mori fibroin gene has been determined by means of combining a shotgun sequencing strategy with physical map-based sequencing procedures. It consists of two exons (67 and 15 750 bp, respectively) and one intron (971 bp). The fibroin coding sequence presents a spectacular organization, with a highly repetitive and G-rich (approximately 45%) core flanked by non-repetitive 5' and 3' ends. This repetitive core is composed of alternate arrays of 12 repetitive and 11 amorphous domains. The sequences of the amorphous domains are evolutionarily conserved and the repetitive domains differ from each other in length by a variety of tandem repeats of subdomains of approximately 208 bp which are reminiscent of the repetitive nucleosome organization. A typical composition of a subdomain is a cluster of repetitive units, Ua, followed by a cluster of units, Ub, (with a Ua:Ub ratio of 2:1) flanked by conserved boundary elements at the 3' end. Moreover some repeats are also perfectly conserved at the peptide level indicating that the evolutionary pressure is not identical along the sequence. A tentative model for the constitution and evolution of this unusual gene is discussed.

[A gun-shot lesion of the internal carotid. A clinical case and review of the literature]. / Lesione della carotide interna da arma da fuoco. Caso clinico e revisione della letteratura.

The authors report a case with penetrating zone II neck wound and internal carotid artery injury. Optimal evaluation and management with vascular injury remains controversial. A review of retrospective studies reported in the literature has demonstrated that physical examination alone may be as accurate as arteriography in detecting significant cervical vascular injuries requiring operative repair. Not unexpectedly, the results of carotid artery repair in neurologically stable patients have been excellent, in front of the results of revascularization in patients with equivocal or less-severe neurologic deficits.

Reverse gyrase, the two domains intimately cooperate to promote positive supercoiling.

Reverse gyrases are atypical topoisomerases present in hyperthermophiles and are able to positively supercoil a circular DNA. Despite a number of studies, the mechanism by which they perform this peculiar activity is still unclear. Sequence data suggested that reverse gyrases are composed of two putative domains, a helicase-like and a topoisomerase I, usually in a single polypeptide. Based on these predictions, we have separately expressed the putative domains and the full-length polypeptide of Sulfolobus acidocaldarius reverse gyrase as recombinant proteins in Escherichia coli. We show the following. (i) The full-length recombinant enzyme sustains ATP-dependent positive supercoiling as efficiently as the wild type reverse gyrase. (ii) The topoisomerase domain exhibits a DNA relaxation activity by itself, although relatively low. (iii) We failed to detect helicase activity for both the N-terminal domain and the full-length reverse gyrase. (iv) Simple mixing of the two domains reconstitutes positive supercoiling activity at 75 degrees C. The cooperation between the domains seems specific, as the topoisomerase domain cannot be replaced by another thermophilic topoisomerase I, and the helicase-like cannot be replaced by a true helicase. (v) The helicase-like domain is not capable of promoting stoichiometric DNA unwinding by itself; like the supercoiling activity, unwinding requires the cooperation of both domains, either separately expressed or in a single polypeptide. However, unwinding occurs in the absence of ATP and DNA cleavage, indicating a structural effect upon binding to DNA. These results suggest that the N-terminal domain does not directly unwind DNA but acts more likely by driving ATP-dependent conformational changes within the whole enzyme, reminiscent of a protein motor.

Gene content and organization of a 281-kbp contig from the genome of the extremely thermophilic archaeon, Sulfolobus solfataricus P2.

The sequence of a 281-kbp contig from the crenarchaeote Sulfolobus solfataricus P2 was determined and analysed. Notable features in this region include 29 ribosomal protein genes, 12 tRNA genes (four of which contain archaeal-type introns), operons encoding enzymes of histidine biosynthesis, pyrimidine biosynthesis, and arginine biosynthesis, an ATPase operon, numerous genes for enzymes of lipopolysaccharide biosynthesis, and six insertion sequences. The content and organization of this contig are compared with sequences from crenarchaeotes, euryarchaeotes, bacteria, and eukaryotes.

[Cecum-colon invagination due to cecal adenocarcinoma. Apropos of two cases]. / Invaginazione cieco-colica da adenocarcinoma del cieco. A proposito di due casi.

The Authors report in an elderly patient a ceco-colic intussusception caused by carcinoma of the cecum, and evaluate etiology and pathogenesis, the most frequently affected anatomical sites, and the various clinical manifestations of the disease. Regarding the latter, the Authors emphasize chronicity of the suboccf1p4ve status in the adult patient vs. the clinical picture of intussusception in the paediatric one. Hemicolectomy represents the most common therapeutic approach, especially when intussusception is irreducible or with the evidence of severe colonic ischemia.

[Blunt traumatic rupture of the diaphragm]. / Le rotture del diaframma da trauma chiuso.

Lesions of the diaphragm are uncommon but important complications of blunt thoraco-abdominal traumas. Their incidence is increasing over the last decades as a consequence of the increase of the road traumatology. Preoperative diagnosis is often difficult especially when the diaphragmatic lesion is associated with other skeletal or visceral injuries that may mask the clinical or radiological signs. The Authors report 12 cases of traumatic lesions of the diaphragm due to blunt trauma observed from 1980 to 1997 and that underwent surgery. In particular they discuss about the importance of an early diagnosis and a correct surgical approach to reduce morbidity and mortality. Nine patients were operated by laparotomy; thoracotomy was performed in one case and the combined approach in the last two patients.

[Palliative cholangiojejunostomy on the duct of hepatic segment III. Our experience]. / Colangiodigiunostomia palliativa sul dotto del 3o segmento epatico. La nostra esperienza.

BACKGROUND: Aim of the paper is to prove that indications for cholangiojejunostomy, in cases when a mean and long term palliation may be expected, are better than those offered by the use of prostheses, without the well known and early bile duct complications. METHODS: Between 1984 and 1995, 12 patients with obstructive jaundice due to malignancy at the hepatic hilum were treated by segment III Roux-en-y or omega cholangiojejunostomy. In 1 patient with no communication between right and left lobe of the liver, biliary-enteric bypass to segment VI duct was also undertaken; in another with neoplastic stenosis of pylorus gastrojejunostomy was performed. Seven patients had carcinoma of the gallbladder, three hilar cholangiocarcinoma, one gastric carcinoma and one recurrent pancreatic carcinoma. RESULTS: There were two postoperative deaths, one for myocardial infarction and one for biliary peritonitis. Six patients had complications: four biliary fistulas with spontaneous resolution and two wound infections. Seven of the ten surviving patients experienced complete resolution of jaundice for at least 4 months. The mean survival of surviving patients was 9.7 months. Nine patients developed recurrent jaundice. CONCLUSIONS: Segment III cholangiojejunostomy is a good palliative treatment in most patients with malignant hilar obstruction.

[Color Doppler echography in the study of pseudo-occlusion of the internal carotid]. / L'eco-color-Doppler nello studio delle pseudo-occlusioni della carotide interna.

The differentiation of pseudo-occlusion from complete internal carotid artery occlusion may have important clinical consequences for patients with the former tend not to benefit from reconstructive surgery. The Authors report a case in which color-Doppler duplex-scanner revealed a persisting string-like lumen that was not demonstrated by angiography. The Authors believe that ultrasonography may in future permit the reliable differentiation of pseudo-from complete carotid occlusion, thereby reducing the need for angiography.

[Surgical treatment of tumors of the ampulla of Vater by local resection]. / Trattamento chirurgico dei tumori dell'ampolla di Vater mediante resezione locale.

The cases of six patients suffering from Vater's ampulla neoplasia were studied 1981 and 1995. All cases are described both clinically and in terms of diagnostic techniques. All patients underwent a transduodenal excision of the neoplasia. A number of factors provided an indication for ampullectomy: the extremely high surgical risk, the suspected benign nature of the lesion or the very small size of the neoplasm associated with no pre-surgery finding of lymphadenomegaly in the area. The following issues were analysed: the accuracy of results obtained by a correct pre-surgery diagnosis, short and long term complications and mortality related to surgery. All patients received a five years post-surgery follow-up. Results show that the ampullectomy can be considered, in selected cases, as a valuable alternative to pancreatoduodenectomy even if further and wider studies are necessary in order to obtain an accurate definition of the correct pre-surgical diagnostic approach and surgical indications.

Cloning and sequencing of the gene coding for topoisomerase I from the extremely thermophilic eubacterium, Thermotoga maritima.

A 2767 bp fragment containing a gene coding for a topoisomerase I from the extremely thermophilic eubacterium Thermotoga maritima (Tm TopA) has been cloned and sequenced. The protein is composed of 633 amino acids with a calculated molecular mass of 72,695 Da. It shares significant similarity with the topoisomerases I of mesophilic eubacteria. The highest score is obtained with Bacillus subtilis (44% identity); in particular, T. maritima and B. subtilis possess an insertion of 7-8 amino acids in the vicinity of the active site, that is absent in topoisomerases of other organisms. A specific feature of T. maritima topoisomerase I is its low cysteine content compared to its mesophilic homologs. It contains 5 cysteine residues, of which 4 could constitute a zinc finger motif. Finally, analysis of the regions flanking the gene reveals that Tm TopA is surrounded by two other ORFs, suggesting the occurrence of a polycistronic transcriptional unit.