A collagen network phase improves cell seeding of open-pore structure scaffolds under perfusion.

Scaffolds with open-pore morphologies offer several advantages in cell-based tissue engineering, but their use is limited by a low cell-seeding efficiency. We hypothesized that inclusion of a collagen network as filling material within the open-pore architecture of polycaprolactone-tricalcium phosphate (PCL-TCP) scaffolds increases human bone marrow stromal cells (hBMSCs) seeding efficiency under perfusion and in vivo osteogenic capacity of the resulting constructs. PCL-TCP scaffolds, rapid prototyped with a honeycomb-like architecture, were filled with a collagen gel and subsequently lyophilized, with or without final crosslinking. Collagen-free scaffolds were used as controls. The seeding efficiency was assessed after overnight perfusion of expanded hBMSCs directly through the scaffold pores using a bioreactor system. By seeding and culturing freshly harvested hBMSCs under perfusion for 3 weeks, the osteogenic capacity of generated constructs was tested by ectopic implantation in nude mice. The presence of the collagen network, independently of the crosslinking process, significantly increased the cell seeding efficiency (2.5-fold), and reduced the loss of clonogenic cells in the supernatant. Although no implant generated frank bone tissue, possibly due to the mineral distribution within the scaffold polymer phase, the presence of a non-crosslinked collagen phase led to in vivo formation of scattered structures of dense osteoids. Our findings verify that the inclusion of a collagen network within open morphology porous scaffolds improves cell retention under perfusion seeding. In the context of cell-based therapies, collagen-filled porous scaffolds are expected to yield superior cell utilization, and could be combined with perfusion-based bioreactor devices to streamline graft manufacture.

Ceramic materials lead to underestimated DNA quantifications: a method for reliable measurements.

In the context of investigating cell-material interactions or of material-guided generation of tissues, DNA quantification represents an elective method to precisely assess the number of cells attached or embedded within different substrates. Nonetheless, nucleic acids are known to electrostatically bind to ceramics, a class of materials commonly employed in orthopaedic implants and bone tissue engineering scaffolds. This phenomenon is expected to lead to a relevant underestimation of the DNA amount, resulting in erroneous experimental readouts. The present work aims at *lpar;i) investigating the effects of DNA-ceramic bond occurrence on DNA quantification, and (ii) developing a method to reliably extract and accurately quantify DNA in ceramic-containing specimens. A cell-free model was adopted to study DNA-ceramic binding, highlighting an evident DNA loss (up to 90%) over a wide range of DNA/ceramic ratios (w/w). A phosphate buffer-based (800 mM) enzymatic extraction protocol was developed and its efficacy in terms of reliable DNA extraction and measurement was confirmed with commonly used fluorometric assays, for various ceramic substrates. The proposed buffered DNA extraction technique was validated in a cell-based experiment showing 95% DNA retrieval in a cell seeding experiment, demonstrating a 3.5-fold increase in measured DNA amount as compared to a conventional enzymatic extraction protocol. In conclusion, the proposed phosphate buffer method consistently improves the DNA extraction process assuring unbiased analysis of samples and allowing accurate and sensitive cell number quantification on ceramic containing substrates.

Targeted photodestruction of human colon cancer cells using charged 17.1A chlorin e6 immunoconjugates.

The goal of this study was to develop a strategy for the selective destruction of colorectal cancer cells. Towards this end, photoimmunoconjugates were prepared between the anti-colon cancer monoclonal antibody 17.1A and the photosensitizer (PS) chlorin(e6) (c(e6)). Polylysine linkers bearing several c(e6) molecules were covalently attached in a site-specific manner to partially reduced IgG molecules, which allowed photoimmunoconjugates to bear either cationic or anionic charges. The conjugates retained immunoreactivity as shown by enzyme-linked immunosorbent assays and by competition studies with native antibody. The overall charge on the photoimmunoconjugate was an important determinant of PS delivery. The cationic photoimmunoconjugate delivered 4 times more c(e6) to the cells than the anionic photoimmunoconjugate, and both 17.1A conjugates showed, in comparison to non-specific rabbit IgG conjugates, selectivity for antigen-positive target cells. Illumination with only 3 J cm(-2) of 666 nm light reduced the number of colony forming cells by more than 90% for the cationic 17.1A conjugate and by 73% for the anionic 17.1A conjugate after incubation with 1 microM c(e6) equivalent of the respective conjugates. By contrast, 1 microM free c(e6) gave only a 35% reduction in colonies. These data suggest photoimmunoconjugates may have applications in photoimmunotherapy where destruction of colorectal cancer cells is required.

Giant retroperitoneal angiomyolipoma. A case report.

We discuss a case of a giant renal angiomyolipoma. A 28 year-old woman presented with a history of a painless and swelling abdominal mass. A computerized tomography (CT) scan of the abdomen demonstrated a 27 x 13 x 11 cm tumor in the right retroperitoneum. At laparotomy, a wide excision of the mass was performed and the histopathological examination of the resected specimen revealed the presence of an angiomyolipoma. The clinical, radiological and pathological findings of this case are reported with a review of the literature.

Experience with the Stentor endograft at four Italian centers.

PURPOSE: To report the outcome of an Italian multicenter trial of endovascular abdominal aortic aneurysm (AAA) exclusion using the Stentor device. METHODS: Between April 1995 and July 1996, 66 patients (63 men; average age 69 years, range 53 to 84) with infrarenal AAAs meeting the inclusion criteria were enrolled. The average diameter of the aneurysm was 4.6 cm (range 4.2 to 7). Three (4.5%) of the 66 AAAs were anastomotic aneurysms. RESULTS: Sixteen (25%) tubular and 50 (76%) bifurcated endograft procedures were attempted; 4 (6.1%) were converted and 1 terminated owing to technical faults with the bifurcated graft's second limb. One tube graft was too short and failed to exclude an anastomotic aneurysm. Sixty (91%) endograft procedures were completed successfully. Six (9.1%) vascular complications occurred, three in one patient who subsequently died of pulmonary embolism 72 hours postoperatively (1.5% mortality). There were four (6.1%) proximal endoleaks; two sealed spontaneously in < 1 month, and a third was converted (7.6% conversion rate). The fourth is being observed. Clinical success (aneurysm exclusion with no death or endoleak) at 30 days was 86.3% (57/66). In the 23-month follow-up of 57 eligible patients, 2 patients died of unrelated causes and 1 graft limb thrombosed, requiring a crossover femoral bypass. One patient was converted to surgical repair at 5 months postoperatively when increasing aneurysm size signaled an undisclosed endoleak (1.8% late conversion rate). Five other secondary endoleaks were treated with endovascular techniques. CONCLUSIONS: The Stentor was technically feasible in 10% to 40% of AAA candidates in this study, although deployment of the second limb was problematic in the bifurcated device. Introduction of the second-generation Vanguard endograft brought this study to an end.

Totally laparoscopic aortobifemoral bypass: a review of 10 patients.

The main purpose of this study is to evaluate the feasibility of totally laparoscopic aortobifemoral bypass for occlusive aortoiliac disease. Ten patients who had incapacitating claudication have been included to date in this investigation. We have designed a transabdominal retroperitoneal technique that allows performance of the procedure without the problems associated with retraction of intraperitoneal organs. During the study, surgery time decreased from 510 to 245 min. Mean total aortic clamping time was 121 min, and the mean time required to perform the aortic anastomosis was 66 min. Mean blood loss was 820 ml. Three patients needed conversion. Postoperative complications developed in three patients. One had an aortoureteral fistula, which needed reoperation; one experienced complications related to a retroaortic left renal vein; and the third had a mild compartment syndrome of the right leg. Totally laparoscopic aortobifemoral bypass is feasible. Laparoscopic aortobifemoral bypass appears to ease the patient's postoperative course and could become in the not so distant future part of the repertoire of the surgeon performing vascular surgery.

European multicentre experience with modular device (Medtronic Aneurx) for the endoluminal repair of infrarenal abdominal aortic aneurysms.

OBJECTIVE: Transfemoral endoluminal repair of AAA, introduced for the first time in the early 90's, has become a very promising alternative to conventional open repair and more and more centers are reporting satisfactory postoperative results in a high percentage of cases. Straight and bifurcated grafts represent the devices available on the market at present and aortic, as well as iliac aneurysmal lesions can be safely treated through a transfemoral approach. The possibility to indicate an endovascular AAA repair is related to the configuration (length and size) of the proximal and distal necks, tortuosity and calcification of the access arteries and to vascular and non-vascular comorbidities, which afflict the patients. The objective of our study was to evaluate the early and late postoperative results in a series of patients affected by infrarenal AAA, who underwent endoluminal repair. MATERIALS AND METHODS: From December 1996 to 31 October 1997 in 5 different European Centers, 100 Medtronic AneuRx bifurcated stent grafts were implanted for infrarenal abdominal aortic aneurysms. The diameter of the AAA varied from 33 to 77 mm (average 64 mm) and the mean age of the patients was 70.8 years (51-87 years). In one patient with a 33 mm diameter of the aneurysm, the surgical procedure was indicated because the size of the aneurysm had increased by 5 mm, compared to the previous control made 2 months before. In addition the aneurysm became symptomatic. There were 92 male and 8 female patients. The average time of the surgical procedure was 150 minutes (75-480 minutes) with an average blood loss of 570 ml (100-2,600 ml).

All-solid-state picosecond tunable source of near-infrared radiation.

A quasi-cw diode-pumped Nd:YAG laser, mode locked by a nonlinear mirror and stabilized by an acousto-optic modulator, has been developed that generates 31-ps, 23-microJ pulses. Employing this source with a periodically poled lithium niobate crystal in a traveling-wave geometry, we obtained extracavity frequency conversion with pump depletion of as much as 62% in the near infrared (1.46- 1.56 microm) with a pulse spectral width of 1.5nm and a beam quality M(2)=1.7.

[Transanal ultrasonography in the study of fistulas of perianal abscess]. / L'ecografia transanale nello studio delle fistole degli ascessi perianali.

The fistulous tracks and abscesses may be related anatomically to the anal sphincters and levator ani muscles. Defining the anatomical relationship between the fistulous lesion and the anal sphincters and/or adjacent organs is essential for correct management. Clinical examination can suggest possible sepsis or the direction of the fistulous track. We report the results of anal endosonography in the evaluation of 54 patients affected by perianal sepsis and fistula in ano. Anal endosonography has correctly identified 22 of 22 internal openings seen at the surgery, 14 of 16 intersphincteric tracts while only 7 of the 9 trans-sphincteric tracks described by anal endosonography were present at the surgery. All the abscesses were correctly identified. Anal endosonography provides a high-resolution image of the anatomy of anal canal and defines the anatomy of tracks and abscesses in relation to the sphincters, determines if there has been trans-sphincteric extension of the sepsis and assesses the state of the sphincters. We have observed a good correlation between the preoperative AES findings and those at surgery. We conclude that anal endosonography is a useful diagnostic procedure in patients with perianal sepsis.

Transanal local resection for benign and malignant rectal tumours.

Local therapy has been widely reported and accepted for benign tumours and carefully selected cancers of the rectum. Thirty-three patients with benign or malignant low rectal tumors have undergone a prospective evaluation after local resection with transanal electroresection as described by Faivre. Patients were divided in three groups: 1) local excision of benign tumours (12 patients), 2) curative resection for localised malignant tumours (7 patients) and 3) palliative local resection for malignant tumours (14 patients). The complications included transient incontinence and rectal bleeding. Patients have been followed for a mean period of 18 months (1-54). In group 3 there were four (28%) recurrences. The remainder of the patients with malignant tumours have been free of disease on follow-up. Although it is ideal for benign neoplasms, further follow-up is needed to determine its true indication in malignant lesions.

[Device for intraarterial access for locoregional chemotherapy in hepatic metastasis from colorectal neoplasms (technical note)]. / Dispositivo di accesso intra-arterioso per chemioterapia locoregionale nelle metastasi epatiche da neoplasie colorettali (note di tecnica).

Metastasis are the most common malignant lesions of the liver. Liver is the most common site of visceral metastasis from colo-rectal carcinoma. Only in few patients are the lesions surgically resectable for cure and standard intravenous chemotherapy produces a low response rate. An intrahepatic arterial device for regional chemotherapy is an effective and safe alternative for unresectable liver metastasis from colorectal carcinoma, with a significant improvement on response rates compared with conventional i.v. chemotherapy; a longer survival is also reported in patients receiving intrahepatic therapy, even if the difference is not statistically significant. The catheter is inserted through the gastro-duodenal artery and the reservoir is placed in a subcutaneous pocket on the anterior thoracic wall. The Authors discuss indications, implantation technique and complications. Intra-arterial chemotherapy is administered in ambulatorial regimen and scintigraphic scanning and/or epatic ultrasonography are performed every three months to evaluate response rate. Median survival is variable from 12 to 17 months in the different series with response rates (disappeared metastases or tumor-mass reduction over 50%) of 48%-62%. The increased tumor responses reported together with a lower systemic toxicity (compared with systemic therapy) suggest that intra-arterial chemotherapy is a reliable and well tolerated treatment.

[Treatment of spontaneous pneumothorax]. / Il trattamento del pneumotorace spontaneo.

Following an analysis of current treatment strategies for spontaneous pneumothorax and their surrounding controversies, the paper reports the Authors' personal experience. From 1 January 1984 to 31 December 1989 a total of 76 cases of spontaneous pneumothorax were treated, of which 3 were bilateral. The M:F ratio was 9:1 and the age of patients ranged between 16 and 77 years (mean age 39.2); 22 cases were relapses (27.8%). Conservative therapy was used in 12 cases (15.1%); pleural drainage was introduced in 54 cases (68.3%) for a mean of 7.5 days. Fourteen thoracotomies were performed in 13 patients (10.4%): bullectomy was performed 10 times with stapler, whereas pleurodesis was obtained in 9 cases using pleural abrasion and in 5 cases using apical pleurectomy plus pleural abrasion. Axillary thoracotomy at the 5th space was most commonly used. No major complications were observed during the postoperative period and, in spite of the minimum follow-up of 3 months, no cases of relapse were observed in operated patients.

[Prevention of colonic ischemia during surgery of the aorta]. / Prevención de la isquemia colónica durante la cirugía de aorta.

The authors report the results of 53 revascularizations of the Inferior Mesenteric Artery, performed during 315 aortic reconstructive procedures, in 19 (35.85%) cases out of a group of 102 aortic aneurysms and 34 (74.15%) cases in a group of 213 aorto-iliac obstructive lesions. The "Carrel patch" technique was always used for the aneurysms of the aorta abdominal cases, whilst this technique was always adopted for only 21 obstructive patients; in the remaining 13 a personal technique was used and is here described. The long term results show a good patency rate (63.7%) for the reimplanted artery, planted artery, but above all no case of colonic ischemia in this group to compare with the 3 cases occurred in the no reimplanted group.

Early gastric cancer: evaluation of diagnostic, clinicopathologic and therapeutic aspects in 60 cases.

A series of 60 patients with early gastric cancer (EGC) operated on from 1.1.1971 to 31.5.1983 is reviewed; since three cases had two and another case even had three synchronous primitive neoplastic lesions, a total of 65 EGC are reported. A prevalence of the "ulcerated" types, a large variability of lesion size and a prevalence of location along the lesser curvature and the antrum was observed; 38 EGC (58.46%) were confined to the mucosa (m), 27 (41.54%) also involved the submucosa; histologically, 53 EGC (81.54%) were of the intestinal type, and 12 (18.46%) were of the diffuse type. Associated lesions, above all chronic atrophic gastritis, intestinal metaplasia and adenomatous gastric polyps were often found. Clinical symptoms were not very specific (epigastric pain, abdominal distension, vomit, dyspepsia, GI hemorrhage) whereas x-ray and endoscopic evaluation had a very high diagnostic accuracy. Our policy is to perform curative resection for gastric cancer, in the form of partial or total gastrectomy with the removal of first level (n1) and second level (n2) lymph node groups and occasionally additional resection of enlarged lymph nodes in the tertiary (n3) group when metastases are suspected. All our patients have been followed up in order to detect any recurrences or metastases.