NIR Emitting Nanoprobes Based on Cyclic RGD Motif Conjugated PbS Quantum Dots for Integrin-Targeted Optical Bioimaging.

Here, silica-coated PbS quantum dots (QDs) with photoluminescence emission properties in the near-infrared (NIR) region are proposed as potential effective single particle optical nanoprobes for future in vivo imaging of tumors. The dispersibility in aqueous medium of hydrophobic PbS QDs was accomplished by growing a silica shell on their surface by exploiting a base assisted water-in-oil microemulsion method. The silica-coated PbS QDs were then conjugated with a specifically designed cyclic arginine-glycine-aspartic acid (cRGD) peptide that is able to specifically recognize αvß3 integrins, which are overexpressed in angiogenic tumor-induced vasculatures and on some solid tumors, to achieve tumor-specific targeting. The cRGD peptide PbS silica-coated QDs were systematically characterized, at each step of their preparation, by means of complementary optical and structural techniques, demonstrating appropriate colloidal stability and the maintenance of their optical futures in aqueous solutions. The cellular uptake of cRGD peptide functionalized luminescent nanostructures in human melanoma cells, where overexpression of αvß3 was observed, was assessed by means of confocal microscopy analysis and cytometric study. The selectivity of the cRGD peptide PbS silica-coated QDs for the αvß3 integrin was established, consequently highlighting the significant potential of the developed NIR emitting nanostructures as optically traceable nanoprobes for future αvß3 integrin receptor in vivo targeting in the NIR region.

Laparoscopic treatment of paraesophageal and mixed diaphragmatic hernias. Report of two cases.

Hiatal hernias are classified into 3 types: sliding hernia (type I), paraesophageal hernia (type II) and mixed hernia (type III), that is a combination of type I and II. The paraesophageal and mixed hernias represent about 5-10% of the surgically treated hiatal hernias. The surgical treatment of the paraesophageal and mixed hernias is unavoidable because of the high risk of severe complications and it has to be considered in a high percentage of cases. The most important technical difficulty in the video-laparoscopic treatment is represented by the hugeness of the hernial defect and by the challenging reduction of the stomach into the abdomen. A cautious dissection of hernial sac and diaphragmatic cruses as well as a careful crural repair make the video-laparoscopic procedure feasible. The operative times are not prolonged and the results are similar to the open technique ones. In literature, the incidence of both intra and postoperative complications doesn't exhibit statistically significant differences between laparoscopic and open techniques. Because of the complexity of the laparoscopic procedure, the minimally invasive access has to be reserved to surgeons who are well trained in those techniques. In this paper we describe 2 cases: one of paraesophageal hernia and the other of mixed hernia which were video-laparoscopically treated with the help, in the second case, of a Gore-Tex mesh. In both cases the technical results were positive. Intra and postoperative complications didn't occur and, one year after the surgical procedure, both patients were in good health and recurrence-free.

Sutureless and stapleless laparoscopic splenectomy using radiofrequency: LigaSure device.

BACKGROUND: Bleeding is the main complication and cause of conversion during laparoscopic splenectomy (LS). We present the advantages of the LigaSure vessel sealing system added to the lateral approach for achieving safe vascular control. METHODS: We performed 63 consecutive LS in a 3-year period using LigaSure in two affiliated university hospitals. We employed a right semilateral position technique with dissection of the spleen and vessel sealing using LigaSure. Forty-two patients had benign hematological disease, 19 had malignant disease, and two had splenic cysts. RESULTS: A total of 58 LS were completed with five conversions due to hilar bleeding (three cases), difficult dissection (one), and massive splenomegaly (one). In all but five patients, blood loss was less than 100 ml. No transfusions were needed. There were five postoperative complications: portal thrombosis (one case), hemoperitoneum (two), surgical wound infection (one), and pleural effusion (one). CONCLUSIONS: The use of LigaSure, and the semilateral position, results in a gain of time and safety. Furthermore, average intraoperative bleeding is very low.

Conformational analysis by NMR and distance geometry techniques of a peptide mimetic of the third helix of the Antennapedia homeodomain.

The Antennapedia homeodomain structure consists of four helices. The helices II and III are connected by a tripeptide that forms a turn, and constitute the well-known helix-turn-helix motif. The recognition helix penetrates the DNA major groove, gives specific protein-DNA contacts and forms direct, or water-mediated, intermolecular hydrogen bonds. It was suggested that helix III (and perhaps also helix IV) might represent the recognition helix of Antennapedia homeodomain, which makes contact with the surface of the major groove of the DNA. In an attempt to clarify the helix III capabilities of assuming an helical conformation when separated from the rest of the protein, we carried out the structural determination of the recognition helix III in different solvent media. The conformational study of fragments 42-53, where residues W48 and F49, not involved in the protein-DNA interaction, were substituted by two alanines, was conducted in sodium dodecyl sulfate (SDS), trifluoroethanol (TFE) and TFE/water, using circular dichroism, nuclear magnetic resonance (NMR) and distance geometry (DG) techniques. The fragment assumes a well-defined secondary structure in TFE and in TFE/water (90/10, v/v) with an alpha-helix encompassing residues 4-9, while in TFE/water (70/30, v/v) a less regular structure was found. The DG results in the micellar system evidence the presence of a distorted alpha-helical conformation involving residues 4-8. Our results reveal that the isolated Antennapedia recognition helix III tend to preserve in solution the alpha-helical conformation even if separated from the rest of the molecule.

Peptide nucleic acids (PNA)-DNA chimeras targeting transcription factors as a tool to modify gene expression.

Peptide nucleic acids (PNAs)-DNA chimeras have been recently described as DNA mimics constituted of a part of PNA and of a part of DNA. We have demonstrated that double stranded molecules based on PNA-DNA chimeras bind to transcription factors in a sequence-dependent manner. Accordingly, these molecules can be used for transcription factor decoy (TFD) pharmacotherapy. Effects of double stranded PNA-DNA chimeras targeting NF-kappaB and Sp1 were determined on in vitro cultured human cells and were found to be comparable to those observed using double-stranded DNA decoys. The TFD molecules based on PNA-DNA chimeras can be further engineered by addition of short peptides facilitating cell penetration and nuclear localization. Therefore, these engineered molecules could be of great interest for in vivo experiments for non-viral gene therapy of a variety of diseases, including neoplastic and viral diseases, for which the TFD approach has been already demonstrated as a very useful strategy.

[Four cases of mesenteric cystic neoformations]. / Neoformazione cistiche mesenteriche. Presentazione di 4 casi.

Four cases of mesenteric cystic neoformations personally observed in the last years are reported. This pathology should not be underestimated, since not only does it present several problems regarding diagnosis and treatment, but a nosologic classification is also difficult to make. Since such cysts present with aspecific symptoms, a definite diagnosis cannot always be reached by a preliminary X-ray investigation, which may lead to various interpretations, but often requires a subsequent histologic examination of operative specimen.

[Adenocarcinoma of pancreas with situs viscerum inversus totalis]. / Adenocarcinoma del pancreas in situs viscerum inversus totalis.

A case of adenocarcinoma of the head of the pancreas in a patient with situs viscerum inversus totalis, an association described for the third time in literature, is reported. The possible coexistence of malformations of transposed organs and the specular anatomosurgical situation requires particular attention in the diagnosis and preoperative evaluation as well as a careful reorientation of the surgical perspective and a correct surgical conduct.

[Giant ovarian cyst. A case weighing 23 kg (50.6 lb). Literature review]. / Cisti ovarica gigante. Presentazione di un caso del peso di 23 kg e revisione della letteratura.

The ovarian cysts are one of the most common affections for females. Besides non-neoplastic functional cysts (follicular or luteal) with relatively small sizes, the neoplastic types, generally benign and that can be ascribed to serous tumors, of 10-15 cm or even bigger should be included. Nowdays, these neoformations are diagnosed relatively early, before they become of big dimensions, even if often they present few symptoms. Then it seems to be interesting to report a case recently observed of an ovarian cyst of 35x45x50 cm and weighing 23 kg in 29-year-old woman.

Structural and kinetic characterization of native laccases from Pleurotus ostreatus, Rigidoporus lignosus, and Trametes trogii.

A comparative study has been performed on five native laccases purified from the three basidiomycete fungi Pleurotus ostreatus, Rigidoporus lignosus, and Trametes trogii to relate their different catalytic capacities to their structural properties. Spectroscopic absorption features and EPR spectra at various pH values of the five enzymes are very similar and typical of the blue oxidases. The analysis of the dependence of kinetic parameters on pH suggested that a histidine residue is involved in the binding of nonphenolic substrates, whereas both a histidine and an acidic residue may be involved in the binding of phenolic compounds. His and an Asp residue are indeed found at the bottom of a cavity which may be regarded as a suitable substrate channel for approaching to type 1 copper in the 3D homology models of the two laccases from Pleuorotus ostreatus (POXC and POXAlb) whose sequences are known.

[Surgical treatment of hemorrhoidal disease using the circular stapler. Analysis of 60 operated cases]. / Trattamento chirurgico della malattia emorroidaria con stapler circolare. Analisi di 60 casi operati.

BACKGROUND: The authors describe their experience of the treatment of hemorrhoidal disease using a circular stapler in order to evaluate the effectiveness of this technique. METHODS: They describe the surgical technique used in a comparative study carried out at Modena Policlinic. A transversal mucohemorrhoidal transection is performed using a circular stapler above the anorectal joint, enabling radical surgery to be completed in a single stage with a rapid and mini-invasive technique. This technique associates the resection of hemorrhoidal nodules and prolapsed mucosa with fixing the residual mucosa to the anal canal and correcting the hypertension and hematic stasis in the venous spaces by breaking the terminal branches of the superior hemorrhoidal artery. Both male and female patients were enrolled in the study, aged over 18 years old, presenting second, third and fourth degree hemorrhoidal prolapse with indications for surgery. The analysis of the long-term follow-up for possible late complications in the 60 selected cases will be reported in a later work. RESULTS: The technique is easy, rapid and causes moderate pain. The postoperative complications are negligible. CONCLUSIONS: A hospital stay limited to a few hours, rapid physical recovery and the absence of out-patient treatment required by this surgical technique, which is comparable to an internal closed hemorrhoidectomy, all offer undoubted advantages, also of a psychological and social nature which amply justify the higher economic and management cost linked to the use of a surgical stapler.

Crystal-state conformation of Calpha,alpha-dialkylated peptides containing chiral beta-homo-residues.

Secondary structure formation and stability are essential features in the knowledge of complex folding topology of biomolecules. To better understand the relationships between preferred conformations and functional properties of beta-homo-amino acids, the synthesis and conformational characterization by X-ray diffraction analysis of peptides containing conformationally constrained Calpha,alpha-dialkylated amino acid residues, such as alpha-aminoisobutyric acid or 1-aminocyclohexane-1-carboxylic acid and a single beta-homoamino acid, differently displaced along the peptide sequence have been carried out. The peptides investigated are: Boc-betaHLeu-(Ac6c)2-OMe, Boc-Ac6c-betaHLeu-(Ac6c)2-OMe and Boc-betaHVal-(Aib)5-OtBu, together with the C-protected beta-homo-residue HCl.H-betaHVal-OMe. The results indicate that the insertion of a betaH-residue at position 1 or 2 of peptides containing strong helix-inducing, bulky Calpha,alpha-disubstituted amino acid residues does not induce any specific conformational preferences. In the crystal state, most of the NH groups of beta-homo residues of tri- and tetrapeptides are not involved in intramolecular hydrogen bonds, thus failing to achieve helical structures similar to those of peptides exclusively constituted of Calpha,alpha-disubstituted amino acid residues. However, by repeating the structural motifs observed in the molecules investigated, a beta-pleated sheet secondary structure, and a new helical structure, named (14/15)-helix, were generated, corresponding to calculated minimum-energy conformations. Our findings, as well as literature data, strongly indicate that conformations of betaH-residues, with the micro torsion angle equal to -60 degrees, are very unlikely.

Preferred conformation of peptides based on cycloaliphatic C(alpha,alpha)-disubstituted glycines: 1-amino-cycloundecane-1-carboxylic acid (Ac11c).

Two complete series of N-protected oligopeptide esters to the pentamer level from 1-amino-cycloundecane-1-carboxylic acid (Ac11c), an alpha-amino acid conformationally constrained through a medium-ring C(i)alpha<-->C(i)alpha cyclization, and either the L-Ala or Aib residue, along with the N-protected Ac11c monomer and homo-dimer alkylamides, have been synthesized by solution methods and fully characterized. The preferred conformation of these model peptides has been assessed in deuterochloroform solution by FT-IR absorption and 1H-NMR techniques. Furthermore, the molecular structures of one derivative (Z-Ac11c-OH) and two peptides (the tripeptide ester Z-Aib-Ac11c-Aib-OtBu and the pentapeptide ester Z-Ac11c-(Aib)2-Ac11c-Aib-OtBu) have been determined in the crystal state by X-ray diffraction. The experimental results support the view that beta-bends and 3(10)-helices are preferentially adopted by peptides rich in Ac11c, the second largest cycloaliphatic C(alpha,alpha)-disubstituted glycine known. This investigation has allowed the authors to approach the completion of a detailed conformational analysis of the whole 1-amino-cycloalkane-1-carboxylic acid (Ac(n)c, with n = 3-12) series, which represents the prerequisite for their recent proposal of the 'Ac(n)c scan' concept.

Crystal structure of the W35A mutant thioredoxin h from Chlamydomonas reinhardtii: the substitution of the conserved active site Trp leads to modifications in the environment of the two catalytic cysteines.

The conformational analysis of W35A thioredoxin h from the eukaryotic green alga Chlamydomonas reinhardtii in the solid state has been carried out by x-ray diffraction, with the aim to clarify the role of Trp in the catalysis. Comparative analysis of W35A mutant with wild-type (WT) thioredoxin shows that, even if the structural motif of thioredoxin is not perturbed, the substitution of Trp35 by an Ala leads to significant changes in protein conformation near the active site. This rearrangement increases its solvent exposure and explains the change of the pKa values of the catalytic cysteines. The substitution of the Trp residue also influences the crystal packing as well as the recognition ability of thioredoxin. The solid state analysis suggests that the Trp residue has a structural function both to force the active site in the bioactive conformation, and to mediate the protein-protein recognition.

Mesenteric cystic neoformations: report of two cases.

The authors present two case reports of mesenteric cystic neoformations which they themselves observed and, with the help of the literature regarding this pathology, discuss the problems of both diagnosis and treatment.

Structure and dynamics of elastin building blocks. Boc-LG-OEt, Boc-VGG-OH.

Short di- and tripeptides such as Boc-LG-OEt, Boc-VG-OEt and Boc-VGG-OH, corresponding to abundant repetitive sequences in elastin, have been extensively studied both in solid state, by X-ray diffraction, and in solution by circular dicroism and nuclear magnetic resonance. Furthermore, theoretical procedures such as simulated annealing and molecular dynamics were also performed on these peptides. In general, the results indicate that no one single structure (be folded or extended) could be representative for these sequences in the protein, but rather that a multiplicity of interconverting conformers, ranging from folded to extended structures, should be considered. In any case, these structures, e.g. beta-turns, polyglycine II and beta-conformations, are those previously suggested to participate to conformational equilibria of elastin.

[Video laparoscopy in patients with pain in the right iliac region]. / La videolaparoscopia nel paziente con dolore in regione iliaca destra.

The authors report on their experience of 235 laparotomy operations and 125 laparoscopic operations performed on patients with right lower abdominal pain. Concerning each of these different approaches, the authors analyzed and compared preoperative diagnosis, anatomo-pathological findings, intraoperative and early post operative morbidity and hospital stay. The ratio of negative open-appendectomies was 24.1% (56 cases out of 233). The laparoscopic approach, performed on 88 cases of suspected appendicitis, allowed to document and to treat other pathologies, real causes of the lower right abdominal pain, in 42 cases (47.7%). The rate of conversion from laparoscopic appendectomy to open appendectomy was only 2.19% (2 cases out of 91). The morbidity rate of laparoscopic appendectomy was estimated at 6.5% (4.4% major complications, 2.2% minor complications). The morbidity rate of open appendectomy was estimated at 8.9% (0.4% major complications, 8.5% minor complications). Though the median postoperative stay, after laparotomy approach, was slightly longer (2.6 days versus 2.4 days), the difference was not statistically significant. Based on these results, the authors conclude that the laparoscopic approach should be reserved for fertile female patients, especially when the diagnosis of appendicitis is uncertain.

[Phantom rectum after Miles' operation]. / Il retto fantasma dopo intervento di Miles.

The authors observed symptoms relating to the existence of a phantom rectum, a phenomenon about which little is still known, in 233 cases (32.1%) in a series of 724 patients undergoing amputation of the abdomino perineal rectum due to malignant neoplasm. The genesis of this phenomenon is attributed to an abnormal reactivity of the cortical and thalamic projection areas with greater response to stimuli from the stump or aspecific visceral stimuli, or even stimuli from the adjacent cortical regions. The psychodynamic aspects linked to the patient's need to develop a different body awareness should not be underestimated; this has to integrate a new anatomic reality, such as colostomy in the place of the anorectum, entailing the relinquishment of the previous body scheme. Prevention and treatment of phantom rectum, which is painful in 27% of cases, is essential for a correct operating technique, adequate psychotherapeutic support, the patient's active participation in a reeducation programme for colostomy management. It should not be forgotten that painful phantom rectum, especially with late onset, may be diagnostically significant as an indicator of the recurrence of neoplastic pathology, sometimes allowing diagnosis to be anticipated by several months. This underlines the importance of carrying out a careful postoperative clinical, biohumoral and radiological control in these patients, including pelvic CT. In the authors' experience of 233 patients suffering from phantom rectum, it was possible to document the presence of neoplastic recidivation in 30 cases (12.8%) using pelvic CT. In these cases, symptoms appeared after a disease-free interval of 26.3 months (range 3-75 months), whereas the presence of phantom rectum without recidivation is usually described in the first 2 months after surgery.

Conformational characterization of the 1-aminocyclobutane-1-carboxylic acid residue in model peptides.

A series of N- and C-protected, monodispersed homo-oligopeptides (to the dodecamer level) from the small-ring alicyclic C alpha, alpha-dialkylated glycine 1-aminocyclobutane-1-carboxylic acid (Ac4c) and two Ala/Ac4c tripeptides were synthesized by solution methods and fully characterized. The conformational preferences of all the model peptides were determined in deuterochloroform solution by FT-IR absorption and 1H-NMR. The molecular structures of the amino acid derivatives Z-Ac4c-OH and Z2-Ac4c-OH, the tripeptides Z-(Ac4c)3-OtBu, Z-Ac4c-(L-Ala)2-OMe and Z-L-Ala-Ac4c-L-Ala-OMe, and the tetrapeptide Z-(Ac4c)4-OtBu were determined in the crystal state by X-ray diffraction. The average geometry of the cyclobutyl moiety of the Ac4c residue was assessed and the tau(N-C alpha-C') bond angle was found to be significantly expanded from the regular tetrahedral value. The conformational data are strongly in favour of the conclusion that the Ac4c residue is an effective beta-turn and helix former. A comparison with the structural propensities of alpha-aminoisobutyric acid, the prototype of C alpha, alpha-dialkylated glycines, and the other extensively investigated members of the family of 1-aminocycloalkane-1-carboxylic acids (Acnc, with n = 3, 5-8) is made and the implications for the use of the Ac4c residue in conformationally constrained peptide analogues are briefly examined.

[Evaluation of costs in surgery of inguinal hernia. Day surgery and one day surgery versus ordinary admission]. / Valutazione dei costi nella chirurgia dell'ernia inguinale. Day surgery e one day surgery versus ricovero ordinario.

The authors have completed an analytic research about costs of hospitalization and treatment for inguinal hernioplasty and costs of anesthesiologic and surgical techniques and hospitalization regimen. The authors consider possible in about 50% of cases the tension-free hernioplasty carried out with local anesthesia and day or one day surgery regimen and they have estimated that it is very less costly then traditional herniorraphy carried out with general anesthesia and hospitalization: L. 1.056.075 versus L. 2.252.650. In Emilia-Romagna we could have a considerable cost-saving, even if only the 50% of patients treated for uncomplicated inguinal hernia every year (7.133 patients with mean hospital stay = 5,8 days and total hospitalization = 41.731 days during 1993) could benefit by treatment in one day surgery regimen. In fact, leaving out of account the advantage of the rapid return the patient to work, the costs of hospital stay, esteemed in L. 25.038.600.000, would be L. 8.558.700.000. A considerable increase of one day surgery hernioplasties should be expected by the hospital administration in budget planning.