Defective Visceral Adipose Tissue Adaptation in Gestational Diabetes Mellitus

CONTEXT

Gestational diabetes mellitus (GDM) is a complex obstetric condition affecting localized glucose metabolism, resulting in systemic metabolic dysfunction.

OBJECTIVE

This cross-sectional study aimed to explore visceral adipose tissue (VAT) as an integral contributor to GDM, focusing on elucidating the specific contribution of obesity and GDM pathology to maternal outcomes.

METHODS

Fifty-six nulliparous pregnant women were recruited, including normal glucose tolerant (NGT) (n = 30) and GDM (n = 26) participants. Participants were subgrouped as nonobese (BMI <30 kg/m2) or obese (BMI ≥30 kg/m2). Metabolic markers in circulation, VAT, and placenta were determined. Morphological analysis of VAT and immunoblotting of the insulin signaling cascade were performed.

RESULTS

GDM participants demonstrated hyperinsulinemia and elevated homeostatic model assessment for insulin resistance (HOMA-IR) scores relative to NGT participants. The GDM-obese subgroup had significant VAT adipocyte hypoplasia relative to NGT-nonobese tissue. GDM-obese VAT had significantly lower insulin receptor substrate (IRS)-2 expression, with elevated ser312 phosphorylation of IRS-1, relative to NGT-nonobese. GDM-obese participants had significantly elevated circulating leptin levels and placental adipsin secretion, while GDM-nonobese participants had elevated circulating adipsin levels with reduced placental adiponectin secretion.

CONCLUSION

These findings suggest that GDM-obese pregnancy is specifically characterized by inadequate VAT remodeling and dysfunctional molecular signaling, which contribute to insulin resistance and hinder metabolic health.

Exposure to Gestational Diabetes Mellitus increases subclinical inflammation mediated in part by obesity

Gestational diabetes mellitus (GDM) is a frequent and serious complication of pregnancy, often associated with obesity. Metabolic dysfunction and metainflammation are evident in both obesity and GDM. In this cross-sectional study we aimed at defining the direct contribution of the immune system in GDM, across the main metabolic tissues, specifically focusing on elucidating the roles of obesity and GDM to the clinical outcome. Using immunoassays and multicolour flow cytometry, cytokine profiles and immune cell frequencies were measured in maternal circulation and central metabolic tissues (placenta and visceral adipose tissue (VAT)) in GDM-diagnosed (n=28) and normal glucose tolerant (n=32) women undergoing caesarean section. Participants were sub grouped as non-obese (BMI <30 kg/m2) or obese (BMI ≥30 kg/m2). Unsupervised data analysis was performed on the flow cytometry data set to identify functional alterations. GDM-obese participants had significantly elevated circulating IL-6 and IL-17A levels. GDM-nonobese participants had elevated circulating IL-12p70, elevated placental IL-17A and VAT IFN- γ production. Unsupervised clustering of immune populations across the three biological sites simultaneously, identified different NK and T-cell phenotypes that were altered in NGT-obese and GDM nonobese participants, while a classical tissue monocyte cluster were increased in GDM-obese participants. In this study, there was significant evidence of subclinical inflammation, and significant alterations in clusters of NK cells, T-cells and tissue monocyte populations in GDM. While increased adiposity assimilates with increased inflammation in the non-pregnant state, this overt relationship may not be as evident during pregnancy and warrants further examination in future longitudinal studies.

L-ergothioneine reduces mitochondrial-driven NLRP3 activation in gestational diabetes mellitus

BACKGROUND

Maternal hyperglycaemia has a significant impact on placental metabolism and mitochondrial function. The NLRP3 inflammasome is responsive to endogenous signals of mitochondrial dysfunction. We tested our hypothesis that mitochondrial dysfunction orchestrates activation of the NLRP3 inflammasome and contributes to inflammation in gestational diabetes mellitus (GDM).

METHODS

Fasting blood, omental and placental tissue were collected on the day of caesarean section from nulliparous women with normal glucose tolerant (NGT) (n = 30) and GDM (n = 27) pregnancies. Cell-free mitochondrial DNA (cf-mtDNA) copy number was quantified by real-time PCR. M1-like (CD14+CD86+CD206-) and M2-like (CD14+CD86+CD206+) macrophage populations were characterized by flow cytometry. Immunoblotting for protein expression of NLRP3, ASC and caspase-1 was performed in maternal BMI and age-matched tissue samples. IL-1β and IL-18 were measured by multiplex ELISA. Placental explants from GDM participants were cultured for 24 h with 1 mM L-ergothioneine (antioxidant) and 1 µM MCC950 (NLRP3 inhibitor).

RESULTS

Cf-mtDNA copy numbers were significantly higher in GDM compared to NGT participants (p = 0.002). Placental populations of CD14+ (p = 0.02) and CD14+CD86+CD206- (p = 0.03) macrophages produced significantly increased levels of mitochondrial superoxide in GDM compared to NGT participants. Placental production of IL-18 (p = 0.04) was significantly increased in GDM. This increase in placental IL-18 was attenuated by treatment with 1 µM MCC950 (p = 0.0005), and 1 mM L-ergothioneine (p = 0.007).

CONCLUSION

Placental inflammation is significantly increased in women with GDM. Furthermore, this increase may be initiated by elevated production of mitochondrial superoxide by macrophage subpopulations and orchestrated by the NLRP3 inflammasome. The mitochondrial antioxidant, L-ergothioneine, ameliorates NLRP3-induced placental inflammation in GDM, identifying a potential therapeutic role.

Heterogenous Differences in Cellular Senescent Phenotypes in Pre-Eclampsia and IUGR following Quantitative Assessment of Multiple Biomarkers of Senescence

Premature ageing of the placenta in pregnancy outcomes is associated with the persistent presence of oxidative stress and placental insufficiency reducing its functional capacity. In this study, we investigated cellular senescence phenotypes of pre-eclampsia and IUGR pregnancies by simultaneously measuring several biomarkers of senescence. Maternal plasma and placental samples were collected at term gestation from nulliparous women undergoing pre-labour elective caesarean section with pre-eclampsia without intrauterine growth restriction (PE; n = 5), pre-eclampsia associated with intrauterine growth restriction (n = 8), intrauterine growth restriction (IUGR < 10th centile; n = 6), and age-matched controls (n = 20). Placental absolute telomere length and senescence gene analysis was performed by RTqPCR. The expression of cyclin-dependent kinase inhibitors (p21 and p16) was determined by Western blot. Senescence-associated secretory phenotypes (SASPs) were evaluated in maternal plasma by multiplex ELISA assay. Placental expression of senescence-associated genes showed significant increases in CHEK1, PCNA, PTEN, CDKN2A, and CCNB-1 (p < 0.05) in pre-eclampsia, while TBX-2, PCNA, ATM, and CCNB-1 expression were evident (p < 0.05) and were significantly decreased in IUGR compared with controls. Placental p16 protein expression was significantly decreased in pre-eclampsia only compared with controls (p = 0.028). IL-6 was significantly increased in pre-eclampsia (0.54 pg/mL ± 0.271 vs. 0.3 pg/mL ± 0.102; p = 0.017) while IFN-γ was significantly increased in IUGR (4.6 pg/mL ± 2.2 vs. 2.17 pg/mL ± 0.8; p = 0.002) compared with controls. These results provide evidence of premature senescence in IUGR pregnancies, and while cell cycle checkpoint regulators are activated in pre-eclampsia, the cellular phenotype is one of cell repair and subsequent proliferation rather than progression to senescence. The heterogeneity of these cellular phenotypes highlights the complexity of characterising cellular senescence and may equally be indicative of the differing pathophysiological insults unique to each obstetric complication.

Maternal pre-eclampsia serum increases neurite growth and mitochondrial function through a potential IL-6-dependent mechanism in differentiated SH-SY5Y cells

Introduction: Pre-eclampsia (PE) is a common and serious hypertensive disorder of pregnancy, which affects 3%-5% of first-time pregnancies and is a leading cause of maternal and neonatal morbidity and mortality. Prenatal exposure to PE is associated with an increased risk of neurodevelopmental disorders in affected offspring, although the cellular and molecular basis of this increased risk is largely unknown. Methods: Here, we examined the effects of exposure to maternal serum from women with PE or a healthy uncomplicated pregnancy on the survival, neurite growth and mitochondrial function of neuronally differentiated human SH-SY5Y neuroblastoma cells, which are commonly used to study neurite growth. Neurite growth and mitochondrial function are two strongly linked neurodevelopmental parameters in which alterations have been implicated in neurodevelopmental disorders. Following this, we investigated the pleiotropic cytokine interleukin-6 (IL-6) levels as a potential mechanism. Results: Cells exposed to 3% (v/v) PE serum for 72 h exhibited increased neurite growth (p < 0.05), which was validated in the human neural progenitor cell line, ReNcell^® VM (p < 0.01), and mitochondrial respiration (elevated oxygen consumption rate (p < 0.05), basal mitochondrial respiration, proton leak, ATP synthesis, and non-mitochondrial respiration) compared to control serum-treated cells. ELISA analysis showed elevations in maternal IL-6 in PE sera (p < 0.05) and placental explants (p < 0.05). In support of this, SH-SY5Y cells exposed to 3% (v/v) PE serum for 24 h had increased phospho-STAT3 levels, which is a key intracellular mediator of IL-6 signalling (p < 0.05). Furthermore, treatment with anti-IL-6 neutralizing antibody blocked the effects of PE serum on neurite growth (p < 0.05), and exposure to IL-6 promoted neurite growth in SH-SY5Y cells (p < 0.01). Discussion: Collectively these data show elevated serum levels of maternal IL-6 in PE, which increases neurite growth and mitochondrial function in SH-SY5Y cells. This rationalizes the further study of IL-6 as a potential mediator between PE exposure and neurodevelopmental outcome in the offspring.

Spinal cord compression as tumor onset: an unusual case report of Hodgkin lymphoma in a teenager

Background

Spinal cord compression (SCC) is an uncommon, severe complication of Hodgkin lymphoma (HL), occurring in 0.2% of cases at the onset and in 6% during disease progression. We present a teenager with SCC with clinical onset of HL; her pre-existing neurological abnormalities covered the presence of an epidural mass, which could have misled us.

Case presentation

A 13-year-old girl presented with a three-month history of lower back pain and degrading ability to walk. She suffered from a chronic gait disorder due to her preterm birth. A magnetic resonance imaging of the spine revealed an epidural mass causing collapse of twelfth thoracic vertebra and thus compression and displacement of the spinal cord. Histological examination with immunohistochemical analysis of the epidural mass demonstrated a classic-type Hodgkin lymphoma. Early pathology-specific treatment allowed to avoid urgent surgery, achieve survival and restore of neurological function.

Conclusions

Children and adolescents with back pain and neurological abnormalities should be prioritized to avoid diagnostic delay resulting in potential loss of neurological function. SCC requires a prompt radiological assessment and an expert multidisciplinary management.

Microspheres vaginal discharge as a complication after Uterine Artery Embolization for intramural/submucosal fibroid

Among Uterine Artery Embolization (UAE) complications, vaginal discharge is considered very frequent, especially for submucosal fibroids. Until now, it was reported as clear odorless viscous material. To our knowledge, we describe the first report of intrauterine microsphere migration after UAE. A 45-year-old-woman was admitted to our hospital complaining metromenorrhagia, menstrual cramping, pelvic pain and dyspareunia. After a preprocedural Magnetic Resonance Imaging (MRI) study, she underwent a superselective transradial UAE using 500-700 µm and 700-900 µm microspheres with a good morphological results. At 2-month follow-up, she complained viscous vaginal discharge with "strange pink stiff sphere of about 2 mm in diameter". A post-procedural-MRI showed fibroid migration towards the uterine cavity, a frequent occurrence especially for submucosal fibroids. The microspheres transvascular migration outside the vessel wall was already reported in a study performed in sheep. Our hypothesis is that the phenomenon of transvascular migration along with the fibroid migration towards the uterine cavity after UAE, may have led the migration of the microspheres directly into the vaginal cavity causing chronic vaginal discharge with pink stiff sphere. Vaginal discharge mixed with "sphere of particles" should be included among the UAE late complication especially for intramural and/or submucosal fibroids with distance to the endometrium less than 2.4 mm at pre-procedural MRI.

What Makes a pDC: Recent Advances in Understanding Plasmacytoid DC Development and Heterogeneity

Dendritic cells (DCs) are professional antigen presenting cells (APCs) that originate in the bone marrow and are continuously replenished from hematopoietic progenitor cells. Conventional DCs (cDCs) and plasmacytoid DCs (pDCs) are distinguished by morphology and function, and can be easily discriminated by surface marker expression, both in mouse and man. Classification of DCs based on their ontology takes into account their origin as well as their requirements for transcription factor (TF) expression. cDCs and pDCs of myeloid origin differentiate from a common DC progenitor (CDP) through committed pre-DC stages. pDCs have also been shown to originate from a lymphoid progenitor derived IL-7R⁺ FLT3⁺ precursor population containing cells with pDC or B cell potential. Technological advancements in recent years have allowed unprecedented resolution in the analysis of cell states, down to the single cell level, providing valuable information on the commitment, and dynamics of differentiation of all DC subsets. However, the heterogeneity and functional diversification of pDCs still raises the question whether different ontogenies generate restricted pDC subsets, or fully differentiated pDCs retain plasticity in response to challenges. The emergence of novel techniques for the integration of high-resolution data in individual cells promises interesting discoveries regarding DC development and plasticity in the near future.

Occupational exposure to fluoro-edenite and prevalence of anti-nuclear autoantibodies

An environmental contamination due to an asbestiform mineral fiber, fluoro-edenite (FE), caused a significantly increased mortality rate for malignant mesothelioma in Biancavilla, Italy. Exposure to fluoro-edenite has been associated with inflammatory processes as an early response to inhaled fibers. The aim was to explore prevalence of anti-nuclear autoantibodies (ANA) in a group of construction workers residing and working in the contaminated area. Prevalences for samples positive to ANA were 60% (n = 9) and 13% (n = 2), for exposed and nonexposed, respectively (p-value <0.05), the odds ratio was 9.75 (95% CI: 1.59-59.69). The significance of elevated ANAs in subjects exposed to fibers is unknown; additional studies may provide a better opportunity to establish a correlation between autoimmunity and environmental exposure.

Prevalence of anti-nuclear autoantibodies in subjects exposed to natural asbestiform fibers: a cross-sectional study

Fluoro-edenite (FE) is an asbestiform mineral fiber spotted in the lava rocks excavated from a stone quarry in Biancavilla (Italy). The derived material had been employed locally for building purposes. Previous studies found evidence that exposure to asbestos may induce autoimmunity, with frequency of anti-nuclear autoantibodies (ANA). The aim of this study was to explore the relationship between FE exposure and autoimmune responses in an exposed population. For the study, 60 subjects living in the area of Biancavilla and 60 subjects as control group were randomly invited to participate. A free medical check, including spirometry and a high-resolution computer tomography chest scan, was given to all participants. ANA were determined by indirect immunofluorescence. On medical check, no subject showed any sign and/or symptoms of illness. Prevalence for samples positive to ANA were 70% (n = 42) and 25% (n = 15), respectively, for exposed and non-exposed subjects (p < 0.05). The presence of pleural plaques (PP) was found in 21 (30%) of the exposed subjects and in 2 (3%) of the non-exposed participants. PP subjects were always ANAs positive. In conclusion, as already it was observed with exposure to asbestos fibers, levels of ANA seemed to significantly increase in subjects who had been exposed to FE. Furthermore, all subjects showing PP were also ANA-positive. This first finding in subjects exposed to FE should encourage researchers to further investigate associations between autoimmune unbalance and environmental exposure to asbestiform fibers.

Nasal metastasis as the first manifestation of a metachronous bilateral renal cell carcinoma

Renal cell carcinoma is one of the most common tumours to spread by extranodal metastases to the head and neck. Metastatic renal cell carcinoma to the head and neck area has been demonstrated mostly in the paranasal sinuses, parotid gland, the mandible, larynx and hypopharinx. Renal cell carcinoma should be excluded whenever a metastatic lesion is encountered in the head and neck area, even if the metastatic lesion is the first clinical presentation. The diagnosis of metastatic RCC should be suspected in any patient with even a remote history of renal cell carcinoma. We report a case of 79 year old woman with recurrent episodes of rhinorrhea, headache, hyposmia and monolateral right epistaxis, with a history of RCC. We describe RCC nasal metastases in a metachronous bilateral neoplasm, in which a second occult lesion debuted with a homolateral nasal metastases, ten years after left nephrectomy.

Lung cancer invading a single left pulmonary vein requiring extended pneumonectomy

Unilateral single left pulmonary vein is a congenital anomaly of the pulmonary venous system. Surgical treatment is not commonly required for this anatomical variant except in rare circumstances. No previous cases of lung cancer involving the intrapericardial portion of a single left pulmonary vein have been published in the peer-reviewed literature. We describe the case of a 69-year-old man with lung cancer invading single left pulmonary vein, which required intrapericardial pneumonectomy and partial resection of the left atrium.

Continuous single cell imaging reveals sequential steps of plasmacytoid dendritic cell development from common dendritic cell progenitors

Functionally distinct plasmacytoid and conventional dendritic cells (pDC and cDC) shape innate and adaptive immunity. They are derived from common dendritic cell progenitors (CDPs) in the murine bone marrow, which give rise to CD11c⁺ MHCII⁻ precursors with early commitment to DC subpopulations. In this study, we dissect pDC development from CDP into an ordered sequence of differentiation events by monitoring the expression of CD11c, MHC class II, Siglec H and CCR9 in CDP cultures by continuous single cell imaging and tracking. Analysis of CDP genealogies revealed a stepwise differentiation of CDPs into pDCs in a part of the CDP colonies. This developmental pathway involved an early CD11c⁺ SiglecH⁻ pre-DC stage and a Siglec H⁺ CCR9^low precursor stage, which was followed rapidly by upregulation of CCR9 indicating final pDC differentiation. In the majority of the remaining CDP pedigrees however the Siglec H⁺ CCR9^low precursor state was maintained for several generations. Thus, although a fraction of CDPs transits through precursor stages rapidly to give rise to a first wave of pDCs, the majority of CDP progeny differentiate more slowly and give rise to longer lived precursor cells which are poised to differentiate on demand.

The administration of drugs inhibiting cholesterol/oxysterol synthesis is safe and increases the efficacy of immunotherapeutic regimens in tumor-bearing mice

Tumor-derived metabolites dampen tumor-infiltrating immune cells and antitumor immune responses. Among the various metabolites produced by tumors, we recently showed that cholesterol oxidized products, namely oxysterols, favor tumor growth through the inhibition of DC migration toward lymphoid organs and by promoting the recruitment of pro-tumor neutrophils within the tumor microenvironment. Here, we tested different drugs capable of blocking cholesterol/oxysterol formation. In particular, we tested efficacy and safety of different administration schedules, and of immunotherapy-based combination of a class of compounds, namely zaragozic acids, which inhibit cholesterol pathway downstream of mevalonate formation, thus leaving intact the formation of the isoprenoids, which are required for the maturation of proteins involved in the immune cell function. We show that zaragozic acids inhibit the in vivo growth of the RMA lymphoma and the Lewis lung carcinoma (LLC) without inducing side effects. Tumor growth inhibition requires an intact immune system, as immunodeficient tumor-bearing mice do not respond to zaragozic acid treatment. Of note, the effect of zaragozic acids is accompanied by a marked reduction in the LXR target genes Abcg1, Mertk, Scd1 and Srebp-1c in the tumor microenvironment. On the other hand, zoledronate, which blocks also isoprenoid formation, did not control the LLC tumor growth. Finally, we show that zaragozic acids potentiate the antitumor effects of active and adoptive immunotherapy, significantly prolonging the overall survival of tumor-bearing mice treated with the combo zaragozic acids and TAA-loaded DCs. This study identifies zaragozic acids as new antitumor compounds exploitable for the treatment of cancer patients.

Natural carcinogenic fiber and pleural plaques assessment in a general population: A cross-sectional study

Natural carcinogenic fibers are asbestos and asbestiform fibers present as a natural component of soils or rocks. These fibers are released into the environment resulting in exposure of the general population. Environmental contamination by fibers are those cases occurred in: rural regions of Turkey, in Mediterranean countries and in other sites of the world, including northern Europe, USA and China. Fluoro-edenite(FE) is a natural mineral species first isolated in Biancavilla, Sicily. The fibers are similar in size and morphology to some amphibolic asbestos fibers, whose inhalation can cause chronic inflammation and cancer. The aim of the current study is to assess the presence and features of pleural plaques (PPs) in Biancavilla's general population exposed to FE through a retrospective cross-sectional study. All High-Resolution Computed Tomography (HRCT) chest scans carried out between June 2009 and June 2015 in Biancavilla municipality hospital site (exposed subjects) were reviewed. The exposed groups were 1:1 subjects, matched according to age and sex distributions, with unexposed subjects (n.1.240) randomly selected among HRCT chest scans carried out in a Hospital 30km away from Biancavilla. Subjects from Biancavilla with PPs were significantly more numerous than the control group ones (218 vs 38). Average age of either group was >60 years; the age of exposed subjects was significantly (p=0.0312) lesser than the unexposed group. In exposed subjects, in most PPs thickness ranged between 2 and 4.9cm(38%, n=83); while in unexposed ones PPs thickness was less than 2cm (55%, n=21). As to the size of PPs in exposed subjects, in most cases it ranged between 1cm and 24% of chest wall (53%, n=116); while in unexposed ones the size of PPs was lesser than 1cm (23%, n=58). Among exposed subjects, 36 cases (17%) PPs were detected with calcification, whereas in unexposed ones only three (8%) presented calcification. 137 lung parenchymal abnormalities were observed in exposed group; whereas, 12 lung parenchymal involvement were registered in unexposed subjects. The RR for PPs is 6,74 CI 95% (4,47-9,58) p<0,0001 in the exposed population. These findings, suggested the urge to extend the screening on the possible involvement of the respiratory tract to all Biancavilla's population, particularly in those aged more than 30. Besides, it seems essential to start indoor monitoring Biancavilla's municipality.

Early effects of fluoro-edenite: correlation between IL-18 serum levels and pleural and parenchymal abnormalities

Fluoro-edenite (FE) is a natural mineral asbestos-like fibrous species first isolated in Biancavilla, Sicily. In order to clarify potential involvement of IL-18 in the pathogenesis of FE-induced chest abnormalities, we analyzed IL-18 serum levels in FE-exposed workers (FEEW) and correlated them with pleural and parenchymal abnormalities. A total of 21 FEEWs, residing in Biancavilla for >30 years, with a working seniority of 17 ± 6.1 years were examined. High-resolution computed tomography scans revealed low grade of fibrosis in 8 (38%) FEEWs, and pleural plaques (PPs) in 13 (62%) FEEWs. The mean IL-18 level was 203.13 ± 90.43 pg/ml. Pearson correlation showed a significant association (p < 0.0001) between IL-18 and PPs and parenchymal abnormality scores. Data suggest a potential role of IL-18 in the pathogenesis of these diseases.

High risk of pleural plaques and parenchymal abnormalities in women living in Biancavilla (Italy)

Fluoro-edenite is a natural mineral species first isolated in Biancavilla, Sicily, used for construction of houses and roads, with health effects allegedly the same as those of asbestos. The aim of the current study was to evaluate the risks of pleural plaques and parenchymal abnormalities in women living in Biancavilla through a retrospective cross-sectional study. The evaluation pointed out a relative risk of pleural plaques of 39.67 (95% CI: 11.33-138.82) and 27.67 (95% CI: 5.43-141.00) for parenchymal abnormalities as well. These findings have prompted urge to extend the screening on the possible abnormalities of the respiratory tract to all Biancavilla's population, particularly in those aged more than 30 years.

FBLN-3 as a biomarker of pleural plaques in workers occupationally exposed to carcinogenic fibers: a pilot study

FBLN-3 has recently been proposed as a biomarker for malignant mesothelioma. A significantly increased standardized mortality rate from malignant mesothelioma has been reported in Biancavilla, Italy. Its cause has been identified in environmental exposure to fluoro-edenite. The aim of this study was to seek a correlation between plasma FBLN-3 concentration and pleural plaques in subjects exposed to fluoro-edenite and in a nonexposed control group. Pleural plaques was never detected in the control group, whereas it was found in 52% of exposed subjects. Median FBLN-3 concentrations were 12.96 and 5.29 ng/ml in the exposed and the control group, respectively (p < 0.001). FBLN-3 plasma levels exhibited a high predictive value for the presence of pleural plaques.

Detection of pleural plaques in workers exposed to inhalation of natural fluoro-edenite fibres

Fluoro-edenite is a natural mineral species initially isolated in Biancavilla, Sicily. The fibres are similar in size and morphology to certain amphibolic asbestos fibres, the inhalation of which may cause chronic inflammation and cancer. Occupational asbestos exposure is known to be associated with pleural and lung diseases, including pleural plaques. The aim of this study was to report the pleural and lung parenchymal lesions detected by high-resolution computed tomography (HRCT) in a group of construction workers exposed to fluoro-edenite. Information regarding life habits and occupational history was collected from 43 workers enrolled into the study. The participants underwent physical examination, blood analysis, search for uncoated fibres and ferruginous bodies in the sputum, pulmonary function tests, including diffusion capacity for carbon monoxide (TL_CO), and HRCT chest imaging. A general descriptive outcome analysis was also conducted; a prevalence ratio (PR) with 95% confidence interval and a two-tailed test P-value were calculated for pleural plaques using log-binomial regression, measuring plaque size and thickness, and cumulative exposure index (CEI). The mean values of the functional respiratory tests were within the normal range for all participants. A restrictive ventilatory defect was identified in two (5%) subjects and an obstructive ventilatory defect in three (7%) subjects. TL_CO was reduced in two additional participants. Fibres were detected in 19 (44%) of subjects. Pleural involvement was documented in 39 (91%) workers, of whom 31 (72%) had bilateral plaques. Calcifications were detected in 25 (58%) of these participants. PR indicated a progressive increase in the risk of developing pleural lesions with rising CEI, i.e. length of exposure. The present findings demonstrate for the first time the presence of pleural plaques in the lungs of subjects exposed to fluoro-edenite fibres, and not to asbestos, through residing in Biancavilla and through their occupation.

The oxysterol-CXCR2 axis plays a key role in the recruitment of tumor-promoting neutrophils

Tumor-derived oxysterols recruit protumor neutrophils in an LXR-independent, CXCR2-dependent manner, thus favoring tumor growth by promoting neoangiogenesis and immunosuppression.

Tumor-infiltrating immune cells can be conditioned by molecules released within the microenvironment to thwart antitumor immune responses, thereby facilitating tumor growth. Among immune cells, neutrophils play an important protumorigenic role by favoring neoangiogenesis and/or by suppressing antitumor immune responses. Tumor-derived oxysterols have recently been shown to favor tumor growth by inhibiting dendritic cell migration toward lymphoid organs. We report that tumor-derived oxysterols recruit protumor neutrophils in a liver X receptor (LXR)–independent, CXCR2-dependent manner, thus favoring tumor growth by promoting neoangiogenesis and immunosuppression. We demonstrate that interfering with the oxysterol–CXCR2 axis delays tumor growth and prolongs the overall survival of tumor-bearing mice. These results identify an unanticipated protumor function of the oxysterol–CXCR2 axis and a possible target for cancer therapy.

Abstract LB-346: The Oxysterol-CXCR2 axis plays a key role in the recruitment of tumor promoting neutrophils

Tumor formation depends on molecular alterations responsible for neoplastic transformation of normal cells, as well as on the ability of tumor cells to co-opt inflammatory/immune cells to create a tumor growth-permissive microenvironment. Targeted therapies inhibiting molecular alterations in tumor cells have improved antitumor responses. However, overall survival has been enhanced only slightly. Tumor-infiltrating immune cells can be conditioned by molecules released within the microenvironment to thwart antitumor immune responses. Among immune cells, neutrophils are recognized as playing an important pro-tumorigenic role, by favoring neoangiogenesis and/or by suppressing antitumor immune responses. We have recently shown that tumor-derived Liver X Receptor (LXR) ligands/oxysterols, known to be involved in cholesterol homeostasis and in modulating physiologic immune responses, favor tumor growth by inhibiting dendritic cell migration towards lymphoid organs. Here, we identify an unanticipated function of tumor-derived LXR ligands/oxysterols, which contribute to the recruitment of neutrophils within tumor microenvironment in an LXR-independent, CXCR2-dependent manner, ultimately favoring tumor growth. In particular, we show a continuous recruitment of neutrophils in oxysterol-releasing tumors, as evaluated by parabiosis experiments. We demonstrate by mass spectrometry and high-performance liquid chromatography analyses that the lymphoma RMA, the Lewis Lung Carcinoma (LLC) and the mesothelioma AB1 produce some oxysterols (22R-HC, 27-HC and 24S-HC), which are able to induce CD11b+Ly6G+ neutrophil migration in vitro and in vivo. Neutrophil migration is independent of LXR signaling both in vitro and in vivo, as demonstrated by using Lxrαβ-/- mice, while it depends on the oxysterol-CXCR2 interaction, as evaluated in vitro by migration experiments with Cxcr2-/- neutrophils, GTPγS binding assays, measurements of cAMP levels, and, in vivo by tumor challenge experiments in Cxcr2-/- bone marrow chimera mice. Tumor-recruited neutrophils are then able to favor tumor growth by promoting neoangiogenesis or immunosuppression of antitumor responses. Furthermore, we demonstrate that RMA, LLC and AB1 tumors engineered to express the oxysterol-inactivating enzyme sulfotransferase 2B1b (SULT2B1b), show a reduced number of tumor-infiltrating neutrophils as well as of CD31+CD45- endothelial cells, as compared to mock-expressing tumors. This reduction parallels tumor growth delay and prolonged survival of SULT2B1b-tumor-bearing mice. Antitumor responses are also obtained with genetic or pharmacologic inactivation of CXCR2, the latter mediated by the CXCR2 antagonist SB225002. These results, along with the observation that some human tumors release oxysterols, identify an unanticipated pro-tumor function of the oxysterol-CXCR2 axis and a possible new target for cancer therapy.

Citation Format: Vincenzo Russo, Laura Raccosta, Raffaella Fontana, Daniela Maggioni, Claudia Lanterna, Aida Paniccia, Andrea Musumeci, Claudio Doglioni, Andrea Leiva, Eduardo J. Villablanca, Rodrigo Mora, Elena Chiricozzi, Maria Grazia Ciampa, Laura Mauri, Alessandro Prinetti, Sandro Sonino, Maria Letizia Trincavelli, Simona Daniele, Claudia Martini, Knut Steffensen, Jan-Ake Gustafsson, Safiyè Gozalvo Feo, Claudio Bordignon, Catia Traversari, Silvano Sozzani. The Oxysterol-CXCR2 axis plays a key role in the recruitment of tumor promoting neutrophils. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-346. doi:10.1158/1538-7445.AM2013-LB-346

Primary neuroendocrine lung tumor presenting with acute ileal obstruction. Case report

The authors describe a clinical case of a patient with neuroendocrine carcinoma of the lung diagnosed after the onset of an intestinal obstruction from an ileal metastasis. A review of literature reveals that the incidence of symptomatic gastro-intestinal metastases from lung cancer has been estimated to be about 2-3% and is exceedingly rare that the intestinal symptoms may be the initial presentation of cancer of the lung. The authors emphasize the difficulty of preoperative diagnosis of gastro-intestinal metastases which is made, almost always, too late because of the lack of specific symptoms. In our case, on account of the computed tomography, we leaned towards the diagnosis of lymphoma because of the double mediastinal and abdominal localization. Furthermore, this diagnosis was supported by the fact that the pulmonary lesion did not have clear radiological features of a lung cancer. The prognosis is poor because once intestinal metastases occur, other metastatic sites, which would make surgery only a palliative measure, are already present. The review of the literature shows that the average survival rate of these patients is 136 days. In our case the patient survived 277 days.

Postoperative hepatic artery aneurysms development and remodeling in Ehlers-Danlos syndrome type IV. Case report

Patients affected by Ehlers-Danlos syndrome (EDS) type IV are at risk for aneurysm formation and rupture. This case report shows the extreme vascular fragility of these patients. We studied a 31-year-old man that developed hepatic artery aneurysms 3 weeks after splenectomy. Computed tomography angiography showed the extreme vascular remodeling of the aneurysms. We conclude that remote site complications should be kept in mind by all surgeons in vascular EDS patients even after general surgery operations.

Aortic valve replacement and coronary artery surgery: determinants affecting early and long-term results

BACKGROUND

We studied factors influencing early and late results in patients operated on for aortic valve replacement and coronary artery bypass graft.

METHODS

175 patients were retrospectively analysed over a 10-year period ending in December 2002. There were 135 males and 40 females with a mean age of 62.7 +/- 8.9 years; 109 were in NYHA class III/IV; 45 required an urgent operation, and 103 mechanical valves and 72 biological valves were implanted.

RESULTS

There were 11 operative deaths (6.3 %). Statistical analysis (logistic regression) showed that previous myocardial infarction, poor NYHA class, and low LVEF had a significant effect on early death. There were 52 late deaths at a mean follow-up of 82.7 +/- 38.8 months. Using a Cox survival analysis for any causes, age, urgent operation, low LVEF, and creatinine had a strong impact on unfavourable late outcome.

CONCLUSIONS

A combination of a patient-related factor (age), cardiac-related condition (low LVEF), co-morbid condition (renal dysfunction), and operative cause (urgent operation) is the most important predictor of late clinical outcome for this combined surgical procedure.

A Safe Immunosuppressive Protocol in Adult-to-Adult Living Related Liver Transplantation

BACKGROUND

In this series of 32 adult-to-adult living related liver transplantations, we assessed the efficacy and safety of basiliximab in combination with a tacrolimus-based regimen. Basiliximab, a chimeric monoclonal antibody directed against the alpha chain of the interleukin-2 (IL-2) receptor (CD25), has been extensively evaluated as induction therapy for cadaveric liver transplant recipients.

PATIENTS AND METHODS

Thirty-two adult-to-adult living related liver transplantations were performed in the last 3 years. All patients received two 20 mg doses of basiliximab (days 0 and 4 posttransplantation) followed by tacrolimus (0.15 mg/kg/d; 10-15 ng/mL target trough levels) and steroids (starting with 20 mg IV switched to PO as soon as the patient was able to eat and weaned within 1-2 months). The average follow-up was 395 days after transplantation.

RESULTS

Of the patients, 93.75% remained rejection-free during follow-up with an actuarial rejection-free probability of 92.59% within 3 months. Two patients (6%) had one episode of biopsy-proven acute cellular rejection (ACR). Actuarial patient and graft survival rates at 3 years were 86.85% and 81.25%. One patient (3%) experienced one episode of sepsis. There was no evidence of cytomegalovirus infections or side effects related to the basiliximab. We found zero de novo malignancy but we observed two patients with metastatic spread of their primary malignancy during the follow-up.

CONCLUSION

Basiliximab in association with tacrolimus and steroids is effective as prophylaxis of ACR among adult living related liver transplant recipients.

Improvements in hepatic parenchymal transection for living related liver donor

INTRODUCTION

To eliminate mortality and morbidity risk in living related liver donors, we developed a new surgical technique to resect hepatic parenchyma using an ultrasonic surgical aspirator in association with a monopolar floating ball cautery.

METHODS

We performed 17 right hepatectomies and 2 left hepatectomies using this technique. We performed a retrospective analysis of perioperative mortality, length of hospitalization (LOS), blood transfused during surgery (IBT), intraoperative blood lost (IBL), biliary complications (BC), and aspartate aminotransferase (AST)/alanine aminotransferase (ALT) peak in the first postoperative week. This group of patients (Group A) was compared, using the analysis of variance (ANOVA) test (P < .05) with 2 different groups of 19 patients: Group B with liver neoplasms that had the same technique as Group A, and Group C wherein a crushing clamp technique was used.

RESULTS

All of the analyzed variables showed significative statistical differences, especially between Group A and Group C (IBL, P < .000; IBT, P < .006; LOS, P < .028; BC, P < .000; AST peak, P < .041; and ALT peak, P < .023).

DISCUSSION

The association of these 2 techniques seems to reduce the LOS, and the need for intraoperative blood transfusions. Moreover, the surgical complications (biliary leaks) and the postoperative parenchymal cytonecrosis seem to be less using this technique.

Acceptance of Marginal Liver Donors Increases the Volume of Liver Transplant: Early Results of a Single-Center Experience

To expand the donor pool, clinicians are continually modifying criteria to accept organs, particularly those in the so-called expanded or marginal donor pool. The concept and definition of a marginal donors continues to evolve. The impact of their use is the result of a combination of donor and recipient factors. Most clinicians accept steatosis above 30%, donor age over 60 years, prolonged ischemia time, prolonged intensive care unit stay, hypernatremia, previous cardiac arrest, prolonged episodes of hypotension, large use of inotrope drugs, and elevated liver function tests as criteria for designation of a marginal organ. In June 2003, we started to use marginal donors each year tripling the number of transplants per year at our center.

Discrete Subaortic Stenosis: Long-Term Prognosis on the Progression of the Obstruction and of the Aortic Insufficiency

BACKGROUND

We sought to determine the long-term rate of progression of left ventricular outflow tract (LVOT) obstruction and aortic insufficiency (AI) in adult patients operated on for discrete subaortic stenosis (DSS).

METHODS

Between 1975 and 1995, 52 patients underwent surgery for DSS; their mean age was 25.4 +/- 14.8 years. Mean preoperative LVOT gradient was 72.8 +/- 25.7 mm Hg. Excision of the subaortic membrane was carried out in all patients, myectomy of the interventricular septum was additionally carried out in 8 patients (15.4 %), and aortic valve replacement (AVR) was performed in 15 patients (28.8 %).

RESULTS

There were 2 operative deaths (3.8 %). Early postoperative LVOT gradient was 9.7 +/- 6.5 mm Hg. Follow-up ranged from 8.1 to 26.6 years. There were 8 late deaths (16.3 %), and mean LVOT gradient was 13.3 +/- 10.7 mm Hg. Five patients required reoperation for recurrent obstruction; 4 patients had a gradient of more than 30 mm Hg. The AI, in patients who did not undergo aortic valve replacement, did not substantially change during follow-up.

CONCLUSIONS

DSS is a variable, unpredictable and progressive disease; recurrent obstruction may reappear despite the adequacy of surgical excision, and is not related to preoperative gradient. Mild AI remains substantially unchanged and AVR is indicated in severe AI.

Can epsilon-aminocaproic acid balance the off-pump bleeding advantage?

BACKGROUND

Aprotinin improved the control of bleeding in patients undergoing surgery with cardiopulmunary bypass, but its use was halted because of the risk of bovine spongiform encephalopathy. We then started to use epsilon-aminocaproic acid and the results in the control of bleeding were satisfactory. To assess its effectiveness in the control of postoperative bleeding precisely, we compared the results for patients operated on for myocardial revascularization on-pump and treated with epsilon-aminocaproic acid with those for patients who decidedly bleed less: off-pump patients.

METHODS

Two groups of patients who had had either on- or off-pump double aortocoronary bypass surgery were retrospectively reviewed for postoperative bleeding. These two almost homogeneous group had two grafts only: left anterior descending and circumflex arteries operated on with cardiopulmonary bypass and treated with the epsilon-aminocaproic acid, and left anterior descending and right coronary arteries operated on off-pump.

RESULTS

Postoperative bleeding through chest drainage at 4 h was 265+/-91.7 mL in the off-pump group and 328.4+/-131.4 mL in the on-pump group (p=0.004). But at 24 h it was 671.6+/-311.5 mL in the off-pump group and 827.8+/-514.4 mL in the on-pump group (p=0.07).

CONCLUSIONS

epsilon-Aminocaproic acid is effective in controlling postoperative bleeding in patients operated on for myocardial revascularization with the aid of cardiopulmonary bypass.

The microsurgical anatomy of the cisternal segment of the trochlear nerve, as seen through different neurosurgical operative windows

OBJECTIVE

To describe the anatomy of the cisternal segment of the trochlear nerve as seen through different neurosurgical approaches.

METHODS

The cisternal course of ten trochlear nerves was observed in five cadaveric embalmed heads, through the view afforded by the median infratentorial-supracerebellar, the extreme-lateral infratentorial-supracerebellar, and the combined presigmoid-subtemporal transtentorial approaches. The relationships of the trochlear nerve with the surrounding neuro-vascular structures were analyzed.

RESULTS

We identified 3 segments of the cisternal trochlear nerve: quadrigeminal, ambient and tentorial. The median infratentorial-supracerebellar approach allowed exposure of the quadrigeminal segment, including the origin of the nerve. The extreme-lateral supracerebellar and the combined presigmoid-subtemporal transtentorial approaches provided visualization of the ambient and tentorial segments of the nerve. The tentorial segment runs in a dural canal contained in the free edge of the tentorium, surrounded by its own arachnoidal sleeve.

CONCLUSION

The trochlear nerve is a very delicate structure that can be easily injured during approaches to the tentorial incisura. Accurate knowledge of its anatomy as seen through different operative windows is helpful in maintaining its integrity during surgery.

Mid-term results of the valve-on-valve technique for bioprosthetic failure

OBJECTIVE

Redo operations for bioprosthesis malfunction can sometimes be technically very demanding and cardiac structures may be damaged. Excising only the leaflets of the damaged bioprosthesis and leaving the old ring in situ on which the 'new' mechanical valve is sutured can, in very selected cases, represent a solution.

METHODS

Twenty-two patients were operated on, with the valve-on-valve technique, from September 1991 through December 1992. There were three operative deaths.

RESULTS

The surviving 19 patients were followed-up from 83 to 98 months (mean 90.5 months.). There were two late deaths. The patients were examined clinically and with transthoracic and transesophageal echocardiograms. All patients were in good condition and the echocardiographic examinations showed no clinically important gradients across the prostheses.

CONCLUSIONS

The valve-on-valve technique, in certain difficult situations, can give successful mid-term results.

Persistent hiccup as presenting symptom in medulla oblongata cavernoma: a case report and review of the literature

A rare case of persistent intractable hiccup as presenting symptom of cavernous angioma in the medulla oblongata is reported. Pathophysiologic hypotheses about the triggering mechanism of hiccup are discussed, with special reference to the causes affecting the central nervous system. A review of the literature concerning medullary lesions presenting with persistent hiccup is also reported. Finally we have included some brief considerations about cavernous angiomas and the patterns of their clinical presentation, focusing on those located in the medulla oblongata.

Bioprosthetic replacement after bioprosthesis failure: a hazardous choice?

BACKGROUND

Following bioprosthetic failure, replacement is usually done with mechanical valves to avoid repeated reoperations.

METHODS

From 1986 to 1996 we operated on 130 patients with bioprosthetic failure, implanting a new bioprosthesis; this group included patients with contraindication to anticoagulation, tricuspid replacement, and specific patient requests. Mean age was 63+/-8 years.

RESULTS

The perioperative mortality was 13.8%. At 10 year follow-up the actuarial estimate of survival was 77.4%+/-6.6%. Freedom from structural valve deterioration was estimated at 81.8%+/-6.3%. Freedom from a third operation was estimated at 85.5%+/-5.2%. No patient was permanently anticoagulated. Freedom from thromboembolism was estimated at 91.5%+/-4%, and there were no hemorrhages. Freedom from cardiac-related deaths was estimated at 85.7%+/-5%.

CONCLUSIONS

This group of patients received the first valve between 1976 and 1986; the range of the cumulative follow-up reaches 20 years, and the extended survival compares favorably with survival of mechanical valves.

Dumbbell-shaped hypoglossal neurinoma: surgical removal via a dorsolateral transcondylar approach. A case report and review of the literature

A case of dumbbell-shaped hypoglossal neurinoma with intra- and extracranial extension is reported. The tumour was surgically completely removed in a one-stage operation via a dorsolateral sub-occipital transcondylar approach. Clinical presentation and the role of high-resolution CT-scan, MRI and angio-MRI in diagnosis and surgical planning are discussed. We include a review of the literature concerning these rare tumours of the foramen magnum region.

Double valve Implantation. Long-term evaluation of 8 different bioprostheses

From January 1976 through December 1987, 194 patients with a mean age of 43.3 +/- 13.7 years (range, 11 to 74 years) underwent double (mitral and aortic) replacement of native valves with 8 types of bioprostheses: Carpentier-Edwards, 127 valves; Hancock, 76 valves; Liotta-Bioimplant, 57 valves; Ionescu-Shiley, 53 valves; Vascor, 27 valves; Carpentier-Edwards Pericardial, 22 valves; Angell-Shiley, 20 valves; and Implamedic, 6 valves. Concomitant cardiac procedures were performed in 25 patients (12.8%). There were 18 operative deaths (9.27%). Our retrospective analysis was restricted to 352 bioprostheses implanted in the 176 patients who survived surgery and were considered at risk for valve tissue failure. The overall cumulative duration of follow-up was 1,174.1 patient-years (range, 1 to 13 years). The durations of follow-up for specific valves were: Carpentier-Edwards, 920.2 valve-years; Hancock, 383.8 valve-years; Liotta-Bioimplant, 310.2 valve-years; Ionescu-Shiley, 357.7 valve-years; Vascor, 131.2 valve-years; Carpentier-Edwards Pericardial, 52.0 valve-years; Angell-Shiley, 167.0 valve-years; and Implamedic, 31.0 valve-years. Thirty patients had thromboembolic accidents, for a linearized incidence of 2.5% per patient-year. At 13 years, the actuarial freedom from thromboembolic accidents was 85.8% +/- 10.7%. Nine patients had endocarditis, for a linearized incidence of 0.7% per patient-year. At 13 years, the actuarial freedom from endocarditis was 92.0% +/- 1.5%. Twenty-four patients had valve tissue failure, for a cumulative linearized incidence of 1.87% per valve-year. The cumulative actuarial probability of freedom from valve tissue failure was 78.6% +/- 3.7% at 10 years and 51.2% +/- 10.7% at 13 years. The 24 patients with valve tissue failure all underwent reoperation: 20 of these had double valve replacement, 3 had aortic valve replacement alone, and 1 had mitral valve replacement alone. The mean interval between initial valve implantation and reoperation was 66.9 +/- 28.8 months. At reoperation, the hospital mortality was 15.1% (5 patients). This study showed that the long-term results of valve implantation are not significantly influenced by either prosthesis design or material. Moreover, the incidence of degenerative change was similar in the aortic and mitral positions.

Bioprostheses at twelve years

From January 1976 through December 1986, seven different types of bioprostheses have been implanted in our center. The following bioprostheses (total 1,414) were implanted in 1,098 patients: Carpentier-Edwards 567, Hancock 302, Liotta 268, Ionescu-Shiley 127, Angell-Shiley 72, Vascor 68, Implamedic 10. Follow-up ranged from 1 to 12 years, cumulative duration of follow-up was 6,747 patient-years and 8,637 valve-years, being 95.4% complete. Cumulative actuarial probability of being free from tissue valve failure (TVF) was 85.1% +/- 2.0% at 10 years, and 61.6% +/- 9.6% at 12 years. Actuarial probability of being free from TVF was 71.2% +/- 10.8% at 12 years for Carpentier-Edwards, 51% +/- 21.7% at 12 years for Hancock, 73.4% +/- 14.1% at 11 years for Angell-Shiley, 53% +/- 27.4% at 9 years for Liotta, 68% +/- 14.8% at 11 years for Ionescu-Shiley, 53.2% +/- 22.2% at 7 years for Vascor, 72.2% +/- 21.5% at 5 years for Implamedic bioprostheses. In this comparison of seven different bioprostheses, there is a large group of valves behaving in a very similar way. Only a few prostheses showed a constant and early negative trend.

The bioprosthetic valve of choice for high-risk patients: long-term results (up to 10 years)

Patients with chronic atrial fibrillation, giant left atrium, left atrial thrombi, and previous embolic accidents are usually treated with life-long anticoagulation after bioprosthetic mitral valve replacement for fear of increased thromboembolic accidents. However, we studied 306 patients in whom we implanted 381 bioprostheses between January 1976 and May 1984, with variations of anticoagulation therapy. The patients' ages ranged between 19 and 68 years, with a mean of 46.2 years. Eighty-six patients were in the New York Heart Association Functional Class II (28.1%), 149 were in Class III (48.7%), and 71 were in Class IV (23.2%). In 90% of the cases, the lesions were rheumatic in origin; the remaining cases were due to bacterial endocarditis, and congenital or ischemic lesions. By analyzing our results, we concluded that high-risk patients with bioprosthetic mitral valves can be safely and advantageously managed with postoperative, temporary anticoagulation.

A preliminary report on low-profile and pericardial bioprostheses: a new combination in particular anatomical situations

Bovine pericardial bioprostheses (BPB), such as the Ionescu-Shiley or the Vascor, and low-profile porcine bioprostheses (Liotta, LPB) have particular features that make them useful in certain anatomical situations, such as aortic stenosis with hypoplastic annulus, pure mitral stenosis with little ventricle and double valvular stenosis with hypertrophic ventricular wall. In such situations, the use of traditional porcine bioprostheses causes problems. We report our experience with BPB and LPB in 25 cases of double valvular stenosis. Operative results were fairly good, and, with the excellent mid-term follow-up by 2-D echo and haemodynamic evaluation, the present authors are confident that these bioprostheses can be considered to be a good alternative to traditional ones and the first choice in particular anatomical situations.