Mesenchymal stem cells and platelet gel improve bone deposition within CAD-CAM custom-made ceramic HA scaffolds for condyle substitution.

PURPOSE: This study evaluated the efficacy of a regenerative approach using mesenchymal stem cells (MSCs) and CAD-CAM customized pure and porous hydroxyapatite (HA) scaffolds to replace the temporomandibular joint (TMJ) condyle. METHODS: Pure HA scaffolds with a 70% total porosity volume were prototyped using CAD-CAM technology to replace the two temporomandibular condyles (left and right) of the same animal. MSCs were derived from the aspirated iliac crest bone marrow, and platelets were obtained from the venous blood of the sheep. Custom-made surgical guides were created by direct metal laser sintering and were used to export the virtual planning of the bone cut lines into the surgical environment. Sheep were sacrificed 4 months postoperatively. The HA scaffolds were explanted, histological specimens were prepared, and histomorphometric analysis was performed. RESULTS: Analysis of the porosity reduction for apposition of newly formed bone showed a statistically significant difference in bone formation between condyles loaded with MSC and condyles without (P < 0.05). The bone ingrowth (BI) relative values of split-mouth comparison (right versus left side) showed a significant difference between condyles with and without MSCs (P < 0.05). Analysis of the test and control sides in the same animal using a split-mouth study design was performed; the condyle with MSCs showed greater bone formation. CONCLUSION: The split-mouth design confirmed an increment of bone regeneration into the HA scaffold of up to 797% upon application of MSCs.

A conceptually new type of bio-hybrid scaffold for bone regeneration.

Magnetic bio-hybrid porous scaffolds have been synthesized, nucleating nano-apatite in situ on self-assembling collagen, in the presence of magnetite nano-particles. The magnetic phase acted as a sort of cross-linking agent for the collagen, inducing a chemico-physical-mechanical stabilization of the material and allowing us to control the porosity network of the scaffold. Gradients of bio-mineralization and magnetization were also developed for osteochondral application. The good potentiality of the material as a biomedical device, able to offer assistance to bone regeneration through scaffold reloading with specific factors guided by an external magnetic field, has been preliminarily investigated. Up to now the proof of this concept has been realized through in vitro assessments.

A novel route in bone tissue engineering: magnetic biomimetic scaffolds.

In recent years, interest in tissue engineering and its solutions has increased considerably. In particular, scaffolds have become fundamental tools in bone graft substitution and are used in combination with a variety of bio-agents. However, a long-standing problem in the use of these conventional scaffolds lies in the impossibility of re-loading the scaffold with the bio-agents after implantation. This work introduces the magnetic scaffold as a conceptually new solution. The magnetic scaffold is able, via magnetic driving, to attract and take up in vivo growth factors, stem cells or other bio-agents bound to magnetic particles. The authors succeeded in developing a simple and inexpensive technique able to transform standard commercial scaffolds made of hydroxyapatite and collagen in magnetic scaffolds. This innovative process involves dip-coating of the scaffolds in aqueous ferrofluids containing iron oxide nanoparticles coated with various biopolymers. After dip-coating, the nanoparticles are integrated into the structure of the scaffolds, providing the latter with magnetization values as high as 15 emu g(-)(1) at 10 kOe. These values are suitable for generating magnetic gradients, enabling magnetic guiding in the vicinity and inside the scaffold. The magnetic scaffolds do not suffer from any structural damage during the process, maintaining their specific porosity and shape. Moreover, they do not release magnetic particles under a constant flow of simulated body fluids over a period of 8 days. Finally, preliminary studies indicate the ability of the magnetic scaffolds to support adhesion and proliferation of human bone marrow stem cells in vitro. Hence, this new type of scaffold is a valuable candidate for tissue engineering applications, featuring a novel magnetic guiding option.

Incidental small ampullary somatostatinoma treated with ampullectomy 2 years after diagnosis.

Somatostatinomas are rare tumors; ampullary somatostatinomas are very rare. We report a case of a small pure somatostatin-producing neuroendocrine tumor of ampulla of Vater in a 54-year-old woman with neither neurofibromatosis nor somatostatinoma syndrome, "incidentally" discovered during an abdominal computed tomography. The patient initially refused other adjunctive exams but after 2 years she was admitted, presenting with itch, night sweats, severe fatigue, and unintentional weight loss. The size of the tumor (1.5 cm) and the other radiologic findings had not changed since the abdominal CT scan 2 years before. The somatostatin, gastrin, glucagons, serotonin, vasoactive intestinal peptide, dopamine, norepinephrine, epinephrine, and calcitonin plasma levels were normal. ERCP-obtained biopsies revealed a neuroendocrine tumor with psammoma bodies; immunohistochemical profile was positive for chromogranin and somatostatin. The patient underwent surgery; intraoperative histologic examination of lymph nodes sampling of perihepatic and periduodenal lymph nodes was negative for metastasis. We performed, therefore, a transduodenal ampullectomy. The patient continues to do well at 3 years' follow-up with no evidence of local or distance recurrence of disease.

High-resolution 3D scaffold model for engineered tissue fabrication using a rapid prototyping technique.

Rapid prototyping, automatic image processing (computer-aided design (CAD)) and computer-aided manufacturing techniques are opening new and interesting prospects for medical devices and tissue engineering, especially for hard tissues such as bone. The development of a bone high-resolution scaffold prototype using these techniques is described. The results testify to the fidelity existing between microtomographic reconstruction and CAD. Furthermore, stereolithographic manufacturing of this scaffold, which possesses a high degree of similarity to the starting model as monitored by morphological evaluations (mean diameter 569 +/- 147 microm), represents a promising result for regenerative medicine applications.

From biomimetic apatites to biologically inspired composites.

Hydroxyapatite is an elective material for bone substitution. In this outline of our recent activity the crucial role of nanostructured ceramics in the design and preparation of ceramic scaffolds will be described, focussing on our more recent interest in biomimetic apatites, in particular apatites containing HPO42- CO32- and Mg2+ which are similar to the mineral component of bone. The paper describes such nanostructured products and, in particular, innovative synthetic techniques capable of yielding powders with higher reactivity and bioactivity. However, so far the characteristics of artificial bone tissues have been shown to be very different from those of natural bone, mainly because of the absence of the peculiar self-organizing interaction between apatites and the protein component. This causes modification of the structure of apatites and of the features of the overall composite forming human bone tissue. Therefore, attempts to mimic the features and structure of natural bone tissue, leading toward so-called bio-inspired materials, will be speculated upon. New techniques used to reproduce a composite in which a nanosize blade-like crystal of hydroxyapatite (HA) grows in contact with self-assembling fibres of natural polymer will be presented. In this specific case, the amazing ability of biological systems to store and process information at the molecular level, nucleating nanosize apatites (bio-inspired material), is exploited.

HA/alginate hybrid composites prepared through bio-inspired nucleation.

Poorly crystalline apatite has been directly nucleated on self-assembling alginate chains by neutralization synthesis to obtain a biomimetic artificial bone-like composite. It has been observed that in preparing HA/alginate composites, Ca2+ ions present on the apatitic surface cross-link the alginate chains to produce a material with different morphology and thermal stability, both functions of the HA/alginate weight ratio. In vitro tests were performed on different samples in terms of both the HA/alginate ratio and synthesis temperature. All the samples were cultured for seven days with MG63 osteoblast-like cells and then underwent morphological and biochemical analyses (MTT and ALP tests). Scaffolds showed a different solubility into the culture media, which was related to the temperature of synthesis and to the HA/alginate ratio. All our data confirm the ability of the tested materials to favour cell growth and to maintain their osteoblastic functionality, at least during the examined period.

Traumatic rupture of nodular focal fatty infiltration of the liver: case report.

Hepatic fatty infiltration generally appears in a widespread form but it can occasionally involve the liver in an irregular way. As regards focal forms, nodular focal fatty infiltration (NFFI) has great importance regarding problems of differential diagnosis with benign and malignant focal pathology of the liver. Except for this aspect, NFFI has little clinical importance as it is mainly asymptomatic. We report a case of an acute bleeding of a big nodule of FFI which required an urgent hepatectomy.

Evolution of the changes of the ileal pouch mucosa over a long follow-up period.

BACKGROUND/AIMS: The mucosa of the ileal pouch after restorative proctocolectomy develops relevant adaptative changes but the real mechanisms and the evolution over time of these alterations are still unclear. The aims of the present work were to study the distribution of the mucosal changes at different levels in the reservoir and to evaluate the evolution of these alterations over a long follow-up period. METHODOLOGY: The severity of chronic and acute inflammation, villous atrophy, colonic-type mucins production and proliferative index were evaluated in the bioptical specimens from 46 patients (30 males, 16 females, mean age 38 years) with functioning pouch. We compared the histology of the upper pouch mucosa with the lower one. Then we divided the 46 patients into Group A-24 patients with a median follow-up of 11 years (range 9-16); Group B-22 patients with a median follow-up of 4 years (range 2-8), comparing the results from the two groups. Finally we performed a prospective evaluation in the 24 patients who were controlled in 3 subsequent follow-ups (1993-1994, 1996-97, 1999-2000). RESULTS: At the topographic evaluation only the acute inflammation was significantly more pronounced in the lower pouch area (p = 0.031). All the morphological changes showed a trend of greater severity in the group A patients, in particular villous atrophy (p = 0.005) and colonic-like mucins secretion (p = 0.006). At the prospective evaluation, the chronic inflammation showed a significant progressive worsening over time (p = 0.011). CONCLUSIONS: Our experience showed that the transformation of the mucosa represents an "organ" response to the luminal environment and may progress over time.

Porous phosphate-gelatine composite as bone graft with drug delivery function.

The design and synthesis of porous phosphate-gelatine composite implant which mimicks the structure of natural bone and has drug delivery function is proposed. Gelatine reproducing the proteinaceous part of bone was cross-linked in order to modulate its solubility in the physiologic fluids. The kinetic of gelatine release from ceramic matrix was also evaluated as model of the release of any therapeutic compound which can be loaded into gelatine.

NTB-A [correction of GNTB-A], a novel SH2D1A-associated surface molecule contributing to the inability of natural killer cells to kill Epstein-Barr virus-infected B cells in X-linked lymphoproliferative disease.

In humans, natural killer (NK) cell function is regulated by a series of receptors and coreceptors with either triggering or inhibitory activity. Here we describe a novel 60-kD glycoprotein, termed NTB-A, that is expressed by all human NK, T, and B lymphocytes. Monoclonal antibody (mAb)-mediated cross-linking of NTB-A results in the induction of NK-mediated cytotoxicity. Similar to 2B4 (CD244) functioning as a coreceptor in the NK cell activation, NTB-A also triggers cytolytic activity only in NK cells expressing high surface densities of natural cytotoxicity receptors. This suggests that also NTB-A may function as a coreceptor in the process of NK cell activation. Molecular cloning of the cDNA coding for NTB-A molecule revealed a novel member of the immunoglobulin superfamily belonging to the CD2 subfamily. NTB-A is characterized, in its extracellular portion, by a distal V-type and a proximal C2-type domain and by a cytoplasmic portion containing three tyrosine-based motifs. NTB-A undergoes tyrosine phosphorylation and associates with the Src homology 2 domain-containing protein (SH2D1A) as well as with SH2 domain-containing phosphatases (SHPs). Importantly, analysis of NK cells derived from patients with X-linked lymphoproliferative disease (XLP) showed that the lack of SH2D1A protein profoundly affects the function not only of 2B4 but also of NTB-A. Thus, in XLP-NK cells, NTB-A mediates inhibitory rather than activating signals. These inhibitory signals are induced by the interaction of NTB-A with still undefined ligands expressed on Epstein-Barr virus (EBV)-infected target cells. Moreover, mAb-mediated masking of NTB-A can partially revert this inhibitory effect while a maximal recovery of target cell lysis can be obtained when both 2B4 and NTB-A are simultaneously masked. Thus, the altered function of NTB-A appears to play an important role in the inability of XLP-NK cells to kill EBV-infected target cells.

Pseudoaneurysm of the common hepatic artery: treatment with a stent-graft.

We report a case of a pseudoaneurysm of the common hepatic artery treated with a stent-graft in a 67-year-old man. The patient presented with severe catheter bleeding through a drain following surgical and interventional procedures performed for therapeutic management of a choledochal cholangiocarcinoma. Selective hepatic arteriography showed a pseudoaneurysm close to the origin of the gastroduodenal artery. After a preliminary attempt at arterial embolization, it was decided to use a stent-graft to bridge the false aneurysm. Complete pseudoaneurysm exclusion was seen after the procedure with preservation of hepatic arterial flow.

[Transfusion-associated graft-versus-host disease guideline on gamma irradiation of blood components]. / Doença do enxerto contra hospedeiro pós-transfusional-guia para irradiação gama de hemocomponentes.

Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare and usually fatal syndrome. Clinical manifestations are fever, maculopapular skin rash, nausea, vomiting, diarrhea, hepatitis and pancytopenia owing to bone marrow hypoplasia. It can occur in recipients with severe immunosuppression and in immunocompetent recipients after transfusion of cellular components from HLA homozygous donor to recipients heterozygous for that HLA haplotype. The diagnosis is made by clinical manifestation and skin biopsy. Antithymocyte globulin and high dose systemic corticosteroids are both the most used therapy. The back of knowledge about this syndrome, the rapid evolution and the absence of treatment response are related to patients bad evolution. Gamma irradiation of blood products has been the mainstay of TA-GVHD prevention. Dose of 2500 cGy is required to completely inactivate T cells. Irradiation damage red cells membrane and the red celis units can not be storage for long time after irradiation. High potassium levels is the mainly change in red cells units. White cell-reduction filters do not prevent TA-GVHD and gamma irradiation does not prevent alloimmunization or blood reactions. Only cellular components like whole blood, red cells, platelets and granulocytes need be irradiated. Ali blood components should be irradiated to: first or second-degree relatives, patients need HLA-matched platelets, recipients of allogeneic or autologous bone marrow transplantation, patients with Hodgkin's disease, patients treated with purine analogue drugs, intrauterine transfusion, pre-term infants and when congenítal immunodeficiency states is suspected. It is recommended irrradiated blood to patients with neoplastic disease when they receive intensive chemotherapy.

Doença do enxerto contra hospedeiro pós-transfusional-guia para irradiaçäo gama de hemocomponentes / Transfusion-associated graft-versus-host disease guideline on gamma irradiation of blood components

A doença enxerto contra hospedeiro transfusional (DECHT) é síndrome rara e geralmente fatal. É caracterizada por febre, eritema cutâneo, náuseas, vômitos, diarréia, hepatite e pancitopenia. Pode ocorrer em pacientes com imunossupressão severa e em pacientes com imunossupressão severa e em pacientes imunocompetentes após a transfusão de hemocomponente celular de doador homozigoto para proteínas HLA às quais o receptor é heterozigoto. O diagnóstico é feito pelo quadro clínico e exame histopatológico da pele. A gamaglobulina antitimocítica associada a altas doses de corticosteróides é a terapêutica mais empregada. O desconhecimento da síndrome, o retardo no diagnóstico, o curso rápido e a ausência de resposta ao tratamento estão relacionados à má evolução dos pacientes. A melhor forma de abordagem da DECHT é a prevenção através da irradiação gama dos hemocomponentes. A dose necessária para completa inativação dos linfócitos T é de 2500 cGy. A principal alteração decorrente da irradiação é o aumento da concentração de potassio nos concentrados de hemácias. Os filtros de leucócitos não previnem o desenvolvimento da DECHT e a irradiação não previne a aloimunização e as reações transfusionais. Apenas hemocomponentes celulares como sangue total, cencentrado de hemácias, concentrado de plaquetas e concentrado de granulócitos, necessitam ser irradiados. Devem ser irradiados os hemocomponentes para transfusão entre familiares, transfusões HLA compatíveis, pacientes submetidos a trasnplante de medula óssea, portadores de doença de Hodgkin, pacientes tratados com análogos da purina, transfusões intra-útero, recém nascidos pré-termo e pacientes com síndrome de imunodeficiência congênita. É recomendável a irradiação de hemocomponentes destinados a pacientes com doenças neoplásicas quando submetidos a protocolos de quimioterapia agressivos.

[Retroperitoneal tumors]. / Tumori retroperitoneali.

The retroperitoneal tumors are seldom met in their several histological expressions. Authors totally considered 27 patients with retroperitoneal tumors and they were observed from 1975 to 1996: 21 of them were primitively cured in this Institute whereas 6 were affected with relapse or metastasis after a surgical approach which had been performed by other structures. Their operability resulted of 100% with an 87% resectability rate. The surgical mortality resulted nil while the morbidity rate was of 44%. The global survival resulted of 60% to 5 years while the disease-free interval was of 35%. The outliving to 5 years resulted of 65% with a 60% disease-free interval only in the patients who were treated in first instance. The surgical therapy represents the only treatment which can modify the clinical history of such neoplasms. Exeresis should be aggressive enough in order to obtain a total extirpation of the mass and grant a right margin of safety of sound tissue. Such radical proceeding should also be pursued in the treatment of relapses and metastases. The therapeutical efficacy is always linked to the precocity the diagnosis. A strict follow-up of the patients who underwent a surgical operation for retroperitoneal neoplasm is therefore necessary. A minority of the instances was only subjected to a complementary radio and/or chemotherapic treatment. Such protections did not significantly modify the outliving.

Parietal seeding of unsuspected gallbladder carcinoma after laparoscopic cholecystectomy.

Laparoscopic cholecystectomy (VALC) represents the treatment of choice for the symptomatic gallstones. However the occurrence of an adenocarcinoma of the gallbladder results a controindication for this surgical technique. We present a case of a 52 years old woman who underwent a VALC; histology revealed a gallbladder adenocarcinoma. For this reason the patient underwent a second operation that is right hepatic trisegmentectomy. Six months later the patient presented with a parietal recurrence at the extraction site of the gallbladder. We discuss the possible mechanism responsible for carcinomatous dissemination during laparoscopic surgery and we raccommend the use of some procedures in order to limit the risk and eventually to treat a neoplastic parietal seeding. These complications suggest the problem about the utility and the future played by video assisted laparoscopic surgery in the diagnosis and treatment of intraabdominal malignancies.

Sintering and characterization of HA and TCP bioceramics with control of their strength and phase purity.

HA and beta-TCP-based ceramics were prepared using commercial powders. Powder characteristics were defined and the processing parameters studied, aimed at the production of samples with improved microstructural and mechanical properties. The behaviour of HA powder subjected to various thermal treatments was investigated in order to control the formation of secondary phases (alpha- and beta-TCP) during sintering. The optimal thermal treatment required to prepare pure beta-TCP powder from the precursors (HA and DCP) was determined and the sintering method required to prepare fully dense beta-TCP completely free from alpha-form, was identified. Translucent hot-pressed beta-TCP ceramics with potential applications in aesthetic restorative prostheses were prepared and characterized. The interval of existence of alpha-TCP and alpha-TCP as secondary products was also defined. Crystallographic analysis was carried out on the imperfectly known low-temperature alpha-TCP phase, and a proper monoclinic unit cell determined.

Surgical treatment of hepatic metastatic colorectal cancer.

73 patients (men age 54 years, range 17-78), underwent an hepatic resection for metastatic, colorectal cancer. Operative mortality was 1.36% Overall 5 years survival rate (Kaplan-Meier) was 27%; 5 years disease free interval was equally 27%. This could demonstrate that 5 years survivors could be also considered free from the risk of metastatic recurrence. This is confirmed by our survivors over 5 years (70-79-94 months) that are still disease free.