The Characterization of a Biodegradable Mg Alloy after Powder Bed Fusion with Laser Beam/Metal Processing for Custom Shaped Implants.

A new Mg-Zn-Zr-Ca alloy in a powder state, intended to be used for custom shaped implants, was obtained via a mechanical alloying method from pure elemental powder. Further, the obtained powder alloy was processed by a PBF-LB/M (powder bed fusion with laser beam/of metal) procedure to obtain additive manufactured samples for small biodegradable implants. A series of microstructural, mechanical and corrosion analyses were performed. The SEM (scanning electron microscopy) analysis of the powder alloy revealed a good dimensional homogeneity, with a uniform colour, no agglutination and almost rounded particles, suitable for the powder bed fusion procedure. Further, the PBF-LB/M samples revealed a robust and unbreakable morphology, with a suitable porosity (that can reproduce that of cortical bone) and without an undesirable balling effect. The tested Young's modulus of the PBF-LB/M samples, which was 42 GPa, is close to that of cortical bone, 30 GPa. The corrosion tests that were performed in PBS (Phosphate-buffered saline) solution, with three different pH values, show that the corrosion parameters have a satisfactory evolution comparative to the commercial ZK 60 alloy.

Microstructural Characterization of Al0.5CrFeNiTi High Entropy Alloy Produced by Powder Metallurgy Route.

Alloys with superior properties represent the main topic of recent studies due to their effectiveness in reducing the cost of equipment maintenance and enhancing usage time, in addition to other benefits in domains such as geothermal, marine, and airspace. Al0.5CrFeNiTi was produced by solid state processing in a planetary ball mill, with the objective of obtaining a high alloying degree and a homogenous composition that could be further processed by pressing and sintering. The metallic powder was technologically characterized, indicating a particle size reduction following mechanical alloying processing when compared to the elemental raw powder materials. The microstructural analysis presented the evolution of the alloying degree during milling but also a compact structure with no major defects in the pressed and sintered bulk samples. The X-ray diffraction results confirmed the presence of face-centered cubic (FCC) and body-centered cubic (BCC) phases, predicted by the theoretical calculations, along with a hexagonal close-packed (HCP) phase, where the Al, Cr, Fe, Ni, and Ti phase was identified in both the alloyed powder material and sintered sample.

Solid-State Processing of CoCrMoNbTi High-Entropy Alloy for Biomedical Applications.

High-entropy alloys (HEAs) gained interest in the field of biomedical applications due to their unique effects and to the combination of the properties of the constituent elements. In addition to the required property of biocompatibility, other requirements include properties such as mechanical resistance, bioactivity, sterility, stability, cost effectiveness, etc. For this paper, a biocompatible high-entropy alloy, defined as bio-HEA by the literature, can be considered as an alternative to the market-available materials due to their superior properties. According to the calculation of the valence electron concentration, a majority of body-centered cubic (BCC) phases were expected, resulting in properties such as high strength and plasticity for the studied alloy, confirmed by the XRD analysis. The tetragonal (TVC) phase was also identified, indicating that the presence of face-centered cubic (FCC) phases in the alloyed materials resulted in high ductility. Microstructural and compositional analyses revealed refined and uniform metallic powder particles, with a homogeneous distribution of the elemental particles observed from the mapping analyses, indicating that alloying had occurred. The technological characterization of the high-entropy alloy-elaborated powder revealed the particle dimension reduction due to the welding and fracturing process that occurs during mechanical alloying, with a calculated average particle size of 45.12 µm.

Biodegradable Magnesium Alloys for Personalised Temporary Implants.

The objective of this experimental work was to examine and characterise the route for obtaining demonstrative temporary biodegradable personalised implants from the Mg alloy Mg-10Zn-0.5Zr-0.8Ca (wt.%). This studied Mg alloy was obtained in its powder state using the mechanical alloying method, with shape and size characteristics suitable for ensuing 3D additive manufacturing using the SLM (selective laser melting) procedure. The SLM procedure was applied to various processing parameters. All obtained samples were characterised microstructurally (using XRD-X-ray diffraction, and SEM-scanning electron microscopy); mechanically, by applying a compression test; and, finally, from a corrosion resistance viewpoint. Using the optimal test processing parameters, a few demonstrative temporary implants of small dimensions were made via the SLM method. Our conclusion is that mechanical alloying combined with SLM processing has good potential to manage 3D additive manufacturing for personalised temporary biodegradable implants of magnesium alloys. The compression tests show results closer to those of human bones compared to other potential metallic alloys. The applied corrosion test shows result comparable with that of the commercial magnesium alloy ZK60.

{332}<113> and {112}<111> Twin Variant Activation during Cold-Rolling of a Ti-Nb-Zr-Ta-Sn-Fe Alloy

Deformation twinning is a phenomenon that causes local shear strain concentrations, with the material either experiencing elongation (and thus a tensile stress) or contraction (compressive stress) along the stress directions. Thus, in order to gauge the performance of the alloy better, it is imperative to predict the activation of twinning systems successfully. The present study investigates the effects of deformation by cold-rolling on the {332}<113> and {112}<111> twin variant activation in a Ti-30Nb-12Zr-5Ta-2Sn-1.25Fe (wt.%) (TNZTSF) alloy. The Ti-30Nb-12Zr-5Ta-2Sn-1.25Fe (wt.%) alloy was synthesized in a cold crucible induction levitation furnace, under an argon-controlled atmosphere, using high-purity elemental components. The TNZTSF alloy was cold-deformed by rolling, in one single step, with a total deformation degree (thickness reduction) of ε ≈ 1% (CR 1), ε ≈ 3% (CR 3), and ε ≈ 15% (CR 15). The microstructural investigations were carried out with the SEM-EBSD technique in order to determine the grain morphology, grain-size distribution, crystallographic orientation, accumulated strain-stress fields and Schmid Factor (SF) analysis, all necessary to identify the active twin variants. The EBSD data were processed using an MTEX Toolbox ver. 5.7.0 software package. The results indicated that the TNZTSF alloy's initial microstructure consists of a homogeneous ß-Ti single phase that exhibits equiaxed polyhedral grains and an average grain-size close to 71 µm. It was shown that even starting with a 1% total deformation degree, the microstructure shows the presence of the {332}<113> twinning ((233)[3¯11] active twin variant; Schmit factor SF = −0.487); at a 3% total deformation degree, one can notice the presence of primary and secondary twin variants within the same grain belonging to the same {332}<113> twinning system ((323¯)[13¯1¯] primary twin variant­SF = −0.460; (233¯)[3¯11¯] secondary twin variant­SF = −0.451), while, at a 15% total deformation degree, besides the {332}<113> twinning system, one can notice the activation of the {112}<111> twinning system ((11¯2)[1¯11] active twin variant­SF = −0.440). This study shows the {332}<113> and {112}<111> twinning variant activation during cold-deformation by rolling in the case of a Ti-30Nb-12Zr-5Ta-2Sn-1.25Fe (wt.%) (TNZTSF) alloy.

In Vivo Sentinel Lymph Node Detection with Indocyanine Green in Colorectal Cancer.

Introduction: The indocyanine green fluorescence imaging system allows the identification of lymphatic vessels, lymph nodes and blood flow during surgery. Colorectal cancer is the second commonest cancer in women, the third in men, being the fourth commonest cause of cancer death. One of the most important factors for staging and prognosis in colorectal cancer is the involvement of the regional lymph nodes. In the literature, there are several methods for identifying sentinel lymph nodes, including methylene blue, technetium (99m Tc) and indocyanine green. The current article presents the use of indocyanate in the identification of sentinel node/nodes in malignant tumors of the colon, by a technique performed in vivo, before the primary ligation of the vascular pedicles. Material and methods:The study was prospectively conducted on a group of 23 patients who had undergone a standard surgical resection - 21 of them for a malignant tumor of the colon and two patients for a malignant rectal tumor - in the 1st General Surgery Department, Emergency University Hospital, Bucharest, Romania, between January 2020-March 2022. During surgery, sentinel lymph node detection was performed using indocyanine green and the Karl Storz® Vitom ICG probe. Sentinel lymph nodes were separately excised and sent to the Department of Pathological Anatomy for analysis. Results:Sentinel nodes were successfully identified in 13 patients and the overall identification rate was 56.52% (13/23 cases). In seven cases, the number of invaded nodes was the same as that of identified and invaded sentinel nodes. Complete lymphadenectomy was performed in all cases regardless of the staining status of the sentinel lymph nodes. Conclusions:The use of fluorescence imaging with indocyanine green in colorectal cancer remains controversial. Since no specific receptor target is used, the fluorescent signal is not specific for lymph node metastases. The learning curve is particularly important for increasing the accuracy of the technique and is responsible for the negative results in some cases. Cases in which lymph nodes have not been invaded require further evaluation through immunohistochemistry and chain polymerization reaction (RT-PCR).

Evolution of Microstructural and Mechanical Properties during Cold-Rolling Deformation of a Biocompatible Ti-Nb-Zr-Ta Alloy.

In this study, a Ti-32.9Nb-4.2Zr-7.5Ta (wt%) titanium alloy was produced by melting in a cold crucible induction in a levitation furnace, and then deforming by cold rolling, with progressive deformation degrees (thickness reduction), from 15% to 60%, in 15% increments. The microstructural characteristics of the specimens in as-received and cold-rolled conditions were determined by XRD and SEM microscopy, while the mechanical characteristics were obtained by tensile and microhardness testing. It was concluded that, in all cases, the Ti-32.9Nb-4.2Zr-7.5Ta (wt%) showed a bimodal microstructure consisting of Ti-ß and Ti-α″ phases. Cold deformation induced significant changes in the microstructural and the mechanical properties, leading to grain-refinement, crystalline cell distortions and variations in the weight-fraction ratio of both Ti-ß and Ti-α″ phases, as the applied degree of deformation increased from 15% to 60%. Changes in the mechanical properties were also observed: the strength properties (ultimate tensile strength, yield strength and microhardness) increased, while the ductility properties (fracture strain and elastic modulus) decreased, as a result of variations in the weight-fraction ratio, the crystallite size and the strain hardening induced by the progressive cold deformation in the Ti-ß and Ti-α″ phases.

Laser Powder Bed Fusion Applied to a New Biodegradable Mg-Zn-Zr-Ca Alloy.

The aim of the present paper is to apply the laser powder bed fusion process to a new biodegradable Mg-Zn-Zr-Ca alloy powder prepared via a mechanical alloying method from powder pure components. This additive manufacturing method is expected to allow for the obtaining of high biomechanical and biochemical performance. Various processing parameters for laser powder bed fusion are tested, with a special focus on laser energy density-E [J/mm3]-which is calculated for all experiment variants, and which represents an important processing parameter, dependent upon all the rest. The goal of all the trials is to find the most efficient schema for the production of small biodegradable parts for the medical domain, meaning the selection of optimal processing parameters. An important observation is that the most robust and homogeneous samples without cracks are obtained for lower values of the E, around 100 J/mm3. Thus, the most performant samples are analyzed by scanning electron microscopy, X-ray diffraction and by compression mechanical test.

Tyrosine kinase inhibitors in breast cancer (Review).

Anti-epidermal growth factor receptor (EGFR)-targeted therapy has been intensely researched in the last years, motivated by the favorable results obtained with monoclonal antibodies in HER2-enriched breast cancer (BC) patients. Most researched alternatives of anti-EGFR agents were tyrosine kinase inhibitors (TKIs) and monoclonal antibodies. However, excluding monoclonal antibodies trastuzumab and pertuzumab, the remaining anti-EGFR molecules have exhibited disappointing results, due to the lack of specificity and frequent adverse side effects. TKIs have several advantages, including reduced cardiotoxicity, oral administration and favorable penetration of blood-brain barrier for brain metastatic BC. Lapatinib and neratinib and recently pyrotinib (approved only in China) are the only TKIs from dozens of molecules researched over the years that were approved to be used in clinical practice with limited indications, in a subset of BC patients, single or in combination with other chemotherapy or hormonal therapeutic agents. Improved identification of BC subtypes and improved characterization of aggressive forms (triple negative BC or inflammatory BC) should lead to advancements in shaping of targeted agents to improve the outcome of patients.

Role of methylene blue in detecting the sentinel lymph node in colorectal cancer: In vivo vs. ex vivo technique.

The identification of sentinel lymph nodes is a valuable oncological method, which aims at mapping lymphatic drainage and has the advantage of correctly staging the disease and assessing prognosis. Lymph node invasion is an important prognostic feature. In colorectal cancer, lymphadenectomy is not influenced by the positive or negative status of the sentinel lymph node. The identification of lymph nodes with possible invasion by staining the primary tumor with methylene blue can lead to improved staging and management. In other words, the consequent administration of neoadjuvant therapy (chemotherapy) to the appropriate patients may result in lower recurrence rates. Thus, the aim of the present study was to use methylene blue to identify the sentinel node/nodes in colorectal cancer and to determine whether the dye-capturing nodes were invaded by the tumor. This is a non-randomized prospective study, in which 26 patients with colon cancer with surgical indication were enrolled. Two types of methods were utilized: in vivo (16 patients) and ex vivo (10 patients). The identification rate was 75% for the in vivo technique and 60% for the ex vivo technique, resulting in a 69.26% overall identification rate. Of 18 patients with sentinel lymph nodes identified using dye, routine histological examination detected metastases in 6 (33.33%) of these patients. In conclusion, further research should be conducted into how the clinical application of sentinel node detection can be employed in colorectal cancer.

"Fistura Score" as a Predictive Instrument for Anastomotic Leak.

Introduction: A patent digestive anastomosis is not only the result of the surgery team experience, but also dependent on the patientâ??s factors. Accepting the possible dramatic effects of an anastomotic leak, identification of risk factors remains a priority in case management. Material and methods: Multifactorial assessment scores permit risk quantification, increase grade of suspicion and early management implementation. The correlation between diverse potential risk factors and anastomotic leak (AL) was studied. The identified risk factors were included in a predictive score system. FISTULA SCORE represents a feasible instrument based on 12 clinical, paraclinical and therapeutic variables, with good statistical significance (Se = 79.5%, Sp = 90.2%). Results: Anastomotic leaks (AL) were observed in 39 cases (7.68%) out of 508 patients analysed, appearing in days 2 - 10 after surgery, with a mean value of 6 days. FISTULA SCORE was based on attributed risks found in our study group for each factor and has the purpose to identify patients at risk for AL and, in some cases, to change the therapeutic or surgical strategy. In AL patients group, the mean score was 5.06 1.95 points, and in AL-free patients group - 1.57 1.61 points. Conclusions: The risk for AL must be appreciated and quantified with a multivariable scoring system. FISTULA SCORE can identify, with a good statistical significance, patient at risk for AL, changing the management of case, reducing length of stay, costs, morbidities, mortality and psychological effects on patient and medical stuff.

Rosai-Dorfman Disease: Breast Involvement-Case Report and Literature Review.

Background and objectives: Rosai-Dorfman disease (RDD) is a type of histiocytosis that usually appears in young adults or children as bilateral cervical lymphadenopathy, but extranodal involvement in not uncommon. Although the pathogenesis is not entirely elucidated, recent studies showed a possible neoplastic process. Materials and methods: Our manuscript presents a rare case of Rosai-Dorfman disease of the breast, the management of this rare case, and a literature review. There are few cases reported of RDD of the breast (around 90 globally reported cases); the data is poor, and the management not yet standardized for these cases. The case reported here shows the importance of correct breast investigation, breast imaging, and ultrasound-guided biopsy that provided an accurate diagnosis and guided further management. Results: Although RDD of the breast was rarely presented as bilateral disease in other case reports, our case showed bilateral breast disease with the suspicion of breast cancer on imaging. Pathology and immunohistochemistry were of critical importance and showed a specific pattern for histiocytosis. A multidisciplinary approach was taken into consideration for these cases in order to establish the approach. Some patients underwent surgery, but watchful waiting and close follow-up were the preferred approach. Conclusions: RDD of the breast is a rare form of histiocytosis, with fewer than 100 globally published cases. Although the management of this disease is not established yet by guidelines, a follow-up approach should be enough for these patients, and surgery might be overtreatment. Mortality from RDD is very low due to comorbidities. A multidisciplinary team decision is important, and abstinence might significantly benefit these patients.

Tailoring a Low Young Modulus for a Beta Titanium Alloy by Combining Severe Plastic Deformation with Solution Treatment.

The present paper analyzed the microstructural characteristics and the mechanical properties of a Ti-Nb-Zr-Fe-O alloy of ß-Ti type obtained by combining severe plastic deformation (SPD), for which the total reduction was of εtot = 90%, with two variants of super-transus solution treatment (ST). The objective was to obtain a low Young's modulus with sufficient high strength in purpose to use the alloy as a biomaterial for orthopedic implants. The microstructure analysis was conducted through X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) investigations. The analyzed mechanical properties reveal promising values for yield strength (YS) and ultimate tensile strength (UTS) of about 770 and 1100 MPa, respectively, with a low value of Young's modulus of about 48-49 GPa. The conclusion is that satisfactory mechanical properties for this type of alloy can be obtained if considering a proper combination of SPD + ST parameters and a suitable content of ß-stabilizing alloying elements, especially the Zr/Nb ratio.

Influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy.

Introduction: Super-Duplex Stainless Steeles (SDSS) proved an excellent potential for its use in many chemical and offshore applications due to their both high mechanical properties and a high corrosion resistance in chloride ion solutions. Objectives: This study evaluates the influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy. Methods: The influence of ageing treatment on microstructural features was analysed by SEM-EBSD (Scanning Electron Microscopy - Electron Backscatter Diffraction) technique, while on mechanical properties by tensile and impact testing techniques. Results: The obtained results show that for the short duration ageing treatments the σ-phase nucleates, within the δ-phase matrix, at the δ/γ grains boundary by the δ → σ precipitation, while for long duration ageing treatments the σ-phase nucleates, within the δ-phase matrix, at the δ/δ grains boundary, or in other favourable nucleation sites, due to the eutectoid decomposition δ → σ + γ2. Experimental data showed that at low temperatures, i.e. 780 °C, in order to induce the precipitation of σ-phase, the minimum incubation time is situated close to 20 min, and that increasing treatment temperature decreases the minimum incubation time, with at 850 °C and 920 °C the σ-phase being firstly detected at 5 min. The σ-phase precipitation shows the highest precipitation kinetics at 850 °C, when the maximum weight-fraction is obtained for each treatment duration when compared with ageing treatments performed at 780 °C and 920 °C. Conclusion: All presented data brings valuable insight into the σ-phase precipitation phenomena and its influence on UNS S32750 SDSS alloy's exhibited mechanical properties and, also, can provide researchers and industrial steel processors a guide regarding the selection of optimal ageing treatment parameters to avoid/minimise the embrittlement induced by the precipitation of deleterious σ-phase.

Hypocalcemia: A possible risk factor for anastomotic leak in digestive surgery.

Anastomotic leaks (ALs) remain the most severe complication in digestive surgery, as well as the most consumptive in terms of human and financial resources. There is an abundance of international research which has focused on identifying and correcting risk factors, and on individualized surgical management as well. The most frequent risk factors are male sex, obesity, diabetes, advanced malignant disease, ASA score, perioperative blood loss or perioperative transfusion, long operation time, emergency operation and altered nutritional status. The aim of the present study was to measure the preoperative serum calcium level and to find a possible correlation between calcium levels and the risk of AL occurrence. A retrospective analysis of medical records for 122 patients who underwent surgical gut resection with anastomosis for different pathologies was carried out. Preoperative serum calcium level and the occurrence of AL was noted. The results revealed that the average value of total blood calcium was 8.78 mg/dl, without a significant difference in sex groups. Hypocalcemia was identified in 44 patients (36.1%). AL was identified in 8 patients (6.6%), with a statistically insignificant difference between male and female patients. The average value of blood calcium in the AL patient group was 8.07 mg/dl, while in patients without AL the average value was 8.83 mg/dl. Hypocalcemia, defined as a serum calcium level below 8.5 mg/dl, was observed in 7 of the 8 patients presenting with AL (87.5%) and 37 patients who did not present with AL (32.5%), a significant difference with which to consider and include hypocalcemia in the group of risk factors for AL (P=0.001). In conclusion, preoperative low serum calcium level can represent a risk factor for AL in digestive surgery.

Prostheses Used in Laparoscopic Inguinal Hernia Repair: Biocompatibility, Postoperative Complications and Quality of Life - Review of the Literature.

INTRODUCTION: There is a continuous concern about meshes used in laparoscopic inguinal hernia repair, which mainly relates to their biocompatibility and ability to decrease postoperative complications and recurrence rate; in other words, efforts are made to find the "ideal" prosthesis. OBJECTIVES: To evaluate different prostheses used in laparoscopic inguinal hernia repair in terms of biocompatibility, postoperative complications, recurrence rate and quality of life, so that all the features could lead us to the "ideal" mesh. MATERIAL AND METHOD: Randomized controlled trials, reviews, prospective and retrospective studies, retrospective cross-sectional and experimental studies on animals published between 2000 and 2016 were analysed with respect to several features of a mesh: biocompatibility, postoperative complications, recurrence rate and quality of life. OUTCOMES: The most common comparison is between heavy-weight and light-weight mesh used in laparoscopic inguinal hernia repair. Experimental studies try to discover the "ideal" prosthesis, which could provide improved biocompatibility, low postoperative complications, decreased recurrence rate and good quality of life. The most commonly used mesh that meats the characteristics of an "ideal" prosthesis is a light-weight monofilament macroporous polypropylene mesh, with a minimum tensile strength >16 N/cm², measuring 10x15 cm. CONCLUSIONS: Published data show that the "ideal" prosthesis used in laparoscopic inguinal hernia repair has not been discovered yet. Regarding heavy- or light-weight meshes, there is no significant effect on recurrence, acute or chronic pain, incidence of seroma or return to daily activity and quality of life (1).

Characterization and In Vitro and In Vivo Assessment of a Novel Cellulose Acetate-Coated Mg-Based Alloy for Orthopedic Applications.

Despite their good biocompatibility and adequate mechanical behavior, the main limitation of Mg alloys might be their high degradation rates in a physiological environment. In this study, a novel Mg-based alloy exhibiting an elastic modulus E = 42 GPa, Mg-1Ca-0.2Mn-0.6Zr, was synthesized and thermo-mechanically processed. In order to improve its performance as a temporary bone implant, a coating based on cellulose acetate (CA) was realized by using the dipping method. The formation of the polymer coating was demonstrated by FT-IR, XPS, SEM and corrosion behavior comparative analyses of both uncoated and CA-coated alloys. The potentiodynamic polarization test revealed that the CA coating significantly improved the corrosion resistance of the Mg alloy. Using a series of in vitro and in vivo experiments, the biocompatibility of both groups of biomaterials was assessed. In vitro experiments demonstrated that the media containing their extracts showed good cytocompatibility on MC3T3-E1 pre-osteoblasts in terms of cell adhesion and spreading, viability, proliferation and osteogenic differentiation. In vivo studies conducted in rats revealed that the intramedullary coated implant for fixation of femur fracture was more efficient in inducing bone regeneration than the uncoated one. In this manner, the present study suggests that the CA-coated Mg-based alloy holds promise for orthopedic aplications.

"Triple positive" breast cancer - a novel category?

Breast cancer (BC) biology is of outmost importance for its therapeutic management and for establishing patients' outcome. Breast cancer has been divided in subtypes depending on the presence of hormone receptors (HRs) for estrogen and progesterone and human epidermal growth factor receptor 2 (HER2) gene amplification. Recently, a distinct subcategory has been analyzed from the group of HER2-enriched BC with positive HR, namely HER2 positive with high levels of hormone receptor expression, suggestively named "triple positive" breast cancer. We aim to review current evidence on this subtype of BC, from the molecular mechanisms regulating its behavior to the current standard treatment outcome in order to establish whether it qualifies as a new distinct subtype of BC. Its biology is dominated by the crosstalks between HR pathway and HER2 pathway, which might be responsible for the development of rapid resistance to treatment, because of estrogen receptor up-regulation and alternate regulatory pathways activation when anti-HER2 agents are used. "Triple positive" subtype has apparently similar outcome when treated with chemotherapy alone, compared to chemotherapy and anti-HER2 agents treatment. It resembles more to luminal A breast cancer, with positive HR and HER2 negative. However, most of the clinical evidence is provided by retrospective trials with multiple potential biases. Treatment of "triple positive" subtype of BC with anti-HER2 agents and chemotherapy remain standard until stronger evidence will be available. Whether "triple positive" category should be regarded as a separate entity with distinct characteristics and management has to be demonstrated in future better designed trials.

Duodenal gastrointestinal stromal tumor presenting as pancreatic head mass - a case report.

Duodenal gastrointestinal stromal tumors (GISTs) are uncommon. Tumors arising from the first and the second part of the duodenum (DI and DII, respectively) can be wrongly diagnosed as pancreatic mass. We present a case of a 59-year-old woman who came with abdominal pain and severe upper gastrointestinal bleeding (hemoglobin 3.5 g÷dL). A solid, heterogeneously enhancing neoplasm in the head of the pancreas was revealed preoperatively by an abdominal computed tomography scan. A diagnosis of GIST was suggested. On exploratory laparotomy, there was a large mass which appeared to be originating from duodenum or from head of pancreas. Intraoperative histopathological diagnosis was GIST. Histopathology showed spindle cell tumor with cytoplasmic eosinophilia and foci of necrosis. The mitotic count was less than 5÷50 high power fields (HPFs). Tumor was involving duodenal muscularis propria, with no infiltration in the duodenal epithelial layer and the pancreas. Immunohistochemical study revealed positive staining for CD117. The tumor was finally diagnosed as GIST arising from the duodenal wall, growing exophytically and attached to the common bile duct and pancreas, without infiltrating the pancreas. Duodenal gastrointestinal stromal tumors can grow exophytically into a large mass and involve the pancreas without infiltrating microscopically and present as pancreatic head mass.

Topical administration of Metamizole and its implications on vascular reactivity in Wistar rats- Experimental research.

Aim: The aim of this paper was to describe the possible implications of topical (ocular) administration of Metamizole on vascular reactivity of the iris in Wistar rats. No other study regarding its topical use was found. Methods: Male adult Wistar rats were anaesthetized with Ketamine 100 mg /kg body weight - injected intraperitoneally - while maintaining spontaneous respiration and the blink reflex. After selecting the area of interest (long posterior ciliary artery - LPCA), manual adjustments of the image magnitude, clarity, and brightness were made, and the experiment began. The image recording lasted 10 minutes. Results: Metamizole induced a slight vasoconstriction that started with the initial moment for all the doses used. After the topical administration of Metamizole, we did not observe an increase of the vascular diameter of LPCA in a dose dependent manner. The saline solution used as a negative control did not modify the vessel diameter. Conclusions: Metamizole (dipyrone) is a non-opioid drug, which is commonly used in human and veterinary medicine. It is the most popular first-line analgesic in various populations. In some cases, this agent is still incorrectly classified as a non-steroidal anti-inflammatory drug. The high analgesic efficacy of metamizole, as well as its spasmolytic effect, makes it a very important pharmaceutical agent that could be used in the therapy of various eye disorders in humans and in animals. Abbreviations: COX = Cyclooxygenase; LPCA = Long Posterior Ciliary Artery; PRP = panretinal photocoagulation; PDR = proliferative diabetic retinopathy; Sec = second(s); VSPR = very severe non proliferative diabetic retinopathy.