Rotary Bend Fatigue of Nitinol to One Billion Cycles.

Nitinol implants, especially those used in cardiovascular applications, are typically expected to remain durable beyond 108 cycles, yet literature on ultra-high cycle fatigue of nitinol remains relatively scarce and its mechanisms not well understood. To investigate nitinol fatigue behavior in this domain, we conducted a multifaceted evaluation of nitinol wire subjected to rotary bend fatigue that included detailed material characterization and finite element analysis as well as post hoc analyses of the resulting fatigue life data. Below approximately 105 cycles, cyclic phase transformation, as predicted by computational simulations, was associated with fatigue failure. Between 105 and 108 cycles, fractures were relatively infrequent. Beyond 108 cycles, fatigue fractures were relatively common depending on the load level and other factors including the size of non-metallic inclusions present and the number of loading cycles. Given observations of both low cycle and ultra-high cycle fatigue fractures, a two-failure model may be more appropriate than the standard Coffin-Manson equation for characterizing nitinol fatigue life beyond 108 cycles. This work provides the first documented fatigue study of medical grade nitinol to 109 cycles, and the observations and insights described will be of value as design engineers seek to improve durability for future nitinol implants.

Comparison of Cytokine Hemadsorption as an Immunomodulator Therapy in COVID-19 Patients with and without Bacterial Sepsis.

BACKGROUND: In this retrospective study, we aimed to compare the laboratory and clinical results of cytokine hem-adsorption as an immunomodulation therapy in COVID-19 ICU patients with or without sepsis. METHODS: The levels of PCT, CRP, and ferritin were determined as indicators of infection/sepsis; the levels of in-terleukins (IL-6, IL-8 and IL-10, and TNF-α) were determined as indicators of cytokine storm were compared. APACHE score, SOFA score, and mortality rates were compared for the progression of the disease in 23 COVID-19 patients. RESULTS: The therapy was generally successful in reducing the levels of IL-6, IL-8, IL-10, and TNF-α but the levels measured after the procedure did not differ among the patients with or without sepsis, suggesting that the presence of sepsis did not affect the efficacy and function of the cytokine hemadsorption procedure in COVID-19 patients. All parameters were reduced after the procedure except the levels of PCT and ferritin and mortality rates of patients diagnosed with sepsis. The level of PCT was significantly higher in these patients compared with the patients without sepsis while the ferritin and mortality did not show any significant difference between the two groups, suggesting that the cytokine hemadsorption may be safe in the treatment of critical COVID-19 patients. CONCLUSIONS: As a result, the progression of sepsis in COVID-19 may be avoided with cytokine hemadsorption applied as an immunomodulator therapy. However, this therapy should be further explored and validated prior to its introduction to everyday clinical practice when the epidemic conditions end.

On the influence of test speed and environment in the fatigue life of small diameter nitinol and stainless steel wire.

To better understand the complex interplay of speed and environment on metals commonly used in implants, rotary bend fatigue tests were conducted on stainless steel and nitinol wires. A range of alternating strains was tested to create ε-N curves at two speeds (physiologic and accelerated) and in three environments (deionized water at body temperature, phosphate buffered saline at body temperature, and laboratory air at ambient room temperature). Results indicate that speed and environment can affect the observed fatigue life in nuanced ways. An electropotential monitoring technique was demonstrated to characterize fatigue crack growth which may be useful in future investigations.

Diffuse Angiogram-Negative Subarachnoid Hemorrhage is Associated with an Intermediate Clinical Course.

BACKGROUND: The cerebral angiography result is negative for an underlying vascular lesion in 15-20% of patients with nontraumatic subarachnoid hemorrhage (SAH). Patients with angiogram-negative SAH include those with perimesencephalic SAH and diffuse SAH. Consensus suggests that perimesencephalic SAH confers a more favorable prognosis than diffuse SAH. Limited data exist to contextualize the clinical course and prognosis of diffuse SAH in relation to aneurysmal SAH in terms of critical care complications, neurologic complications, and functional outcomes. Here we compare the clinical course and functional outcomes of patients with perimesencephalic SAH, diffuse SAH, and aneurysmal SAH to better characterize the prognostic implications of each SAH subtype. METHODS: We conducted a retrospective cohort study that included all patients with nontraumatic SAH admitted to a tertiary care referral center between January 1, 2012, and December 31, 2017. Bleed patterns were radiographically adjudicated, and patients were assigned to three groups: perimesencephalic SAH, diffuse SAH, and aneurysmal SAH. Patient demographics, complications, and clinical outcomes were reported and compared. RESULTS: Eighty-six patients with perimesencephalic SAH, 174 with diffuse SAH, and 998 with aneurysmal SAH presented during the study period. Patients with aneurysmal SAH were significantly more likely to be female, White, and active smokers. There were no significant differences between patients with diffuse SAH and perimesencephalic SAH patterns. Critical care complications were compared across all three groups, with significant between-group differences in hypotension and shock (3.5% vs. 16.1% vs. 38.4% for perimesencephalic SAH vs. diffuse SAH vs. aneurysmal SAH, respectively; p < 0.01) and endotracheal intubation (0% vs. 26.4% vs. 48.8% for perimesencephalic SAH vs. diffuse SAH vs. aneurysmal SAH, respectively; p < 0.01). Similar trends were noted with long-term supportive care with tracheostomy and gastrostomy tubes and length of stay. Cerebrospinal fluid diversion was increasingly required across bleed types (9.3% vs. 54.6% vs. 76.3% for perimesencephalic SAH vs. diffuse SAH vs. aneurysmal SAH, respectively, p < 0.001). Vasospasm and delayed cerebral ischemia were comparable between perimesencephalic SAH and diffuse SAH but significantly lower than aneurysmal SAH. Patients with diffuse SAH had intermediate functional outcomes, with significant rates of nonhome discharge (23.0%) and poor functional status on discharge (26.4%), significantly higher than patients with perimesencephalic SAH and lower than patients with aneurysmal SAH. Diffuse SAH similarly conferred an intermediate rate of good functional outcomes at 1-6 months post discharge (92.3% vs. 78.6% vs. 47.3% for perimesencephalic SAH vs. diffuse SAH vs. aneurysmal SAH, respectively; p < 0.016). CONCLUSIONS: We confirm the consensus data that perimesencephalic SAH is associated with a more benign clinical course but demonstrate that diffuse SAH confers an intermediate prognosis, more malignant than perimesencephalic SAH but not as morbid as aneurysmal SAH. These results highlight the significant morbidity associated with diffuse SAH and emphasize need for vigilance in the acute care of these patients. These patients will likely benefit from continued high-acuity observation and potential support to avert significant risk of morbidity and neurologic compromise.

Low prevalence of SARS-CoV-2 infection in inflammatory bowel disease.

OBJECTIVE: Treatments used in Inflammatory Bowel Disease (IBD) have been associated with enhanced risk of viral infections and viral reactivation, however, it remains unclear whether IBD patients have increased risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. The aim of the study was to examine the prevalence of SARS-CoV-2 IgG positivity in IBD patients followed at our referral center. The role of treatments for IBD and risk factors for infection were also evaluated. PATIENTS AND METHODS: In a prospective study, all IBD patients followed at our referral centre between May 27th and July 21st, 2020 and fulfilling the inclusion criteria were tested for SARS-CoV-2 IgG. Specific IgG antibodies were evaluated by a commercial ELISA kit and SARS-CoV-2 nasopharyngeal swab was performed in seropositive patients. RESULTS: Two-hundred and eighteen patients, 128 Crohn's disease (CD) and 90 Ulcerative colitis (UC) [age 44, (19-77) years; ongoing biologics in 115 (52.7%)] were enrolled. No patient had major SARS-CoV-2-related symptoms. SARS-CoV-2 IgG were detected in 3 out of 218 (1.37%) patients with IBD (2 CD and 1 UC), all on biologics (2.6%). In all of the 3 seropositive patients, the nasopharyngeal swab was negative. There was no relationship between SARS-CoV-2 seroprevalence and the demographic/clinical characteristics of IBD patients. In contrast, history of recent travel was more frequent in the SARS-CoV-2 seropositive patients (2/3; 66.6%) than in SARS-CoV-2 seronegative patients [7/215 (3.25%); p<0.0001]. CONCLUSIONS: The prevalence of SARS-CoV-2 IgG seropositivity in IBD patients appears to be comparable to the non-IBD population and not influenced by ongoing treatments. Risk factors for infection common to the general non-IBD population should be considered when managing patients with IBD.

Synchrotron microtomography applied to the volumetric analysis of internal structures of Thoropa miliaris tadpoles.

Amphibians are models for studying applied ecological issues such as habitat loss, pollution, disease, and global climate change due to their sensitivity and vulnerability to changes in the environment. Developmental series of amphibians are informative about their biology, and X-ray based 3D reconstruction holds promise for quantifying morphological changes during growth-some with a direct impact on the possibility of an experimental investigation on several of the ecological topics listed above. However, 3D resolution and discrimination of their soft tissues have been difficult with traditional X-ray computed tomography, without time-consuming contrast staining. Tomographic data were initially performed (pre-processing and reconstruction) using the open-source software tool SYRMEP Tomo Project. Data processing and analysis of the reconstructed tomography volumes were conducted using the segmentation semi-automatic settings of the software Avizo Fire 8, which provide information about each investigated tissues, organs or bone elements. Hence, volumetric analyses were carried out to quantify the development of structures in different tadpole developmental stages. Our work shows that synchrotron X-ray microtomography using phase-contrast mode resolves the edges of the internal tissues (as well as overall tadpole morphology), facilitating the segmentation of the investigated tissues. Reconstruction algorithms and segmentation software played an important role in the qualitative and quantitative analysis of each target structure of the Thoropa miliaris tadpole at different stages of development, providing information on volume, shape and length. The use of the synchrotron X-ray microtomography setup of the SYRMEP beamline of Elettra Synchrotron, in phase-contrast mode, allows access to volumetric data for bone formation, eye development, nervous system and notochordal changes during the development (ontogeny) of tadpoles of a cycloramphid frog Thoropa miliaris. As key elements in the normal development of these and any other frog tadpole, the application of such a comparative ontogenetic study, may hold interest to researchers in experimental and environmental disciplines.

Superhydrophobic lab-on-chip measures secretome protonation state and provides a personalized risk assessment of sporadic tumour.

Secretome of primary cultures is an accessible source of biological markers compared to more complex and less decipherable mixtures such as serum or plasma. The protonation state (PS) of secretome reflects the metabolism of cells and can be used for cancer early detection. Here, we demonstrate a superhydrophobic organic electrochemical device that measures PS in a drop of secretome derived from liquid biopsies. Using data from the sensor and principal component analysis (PCA), we developed algorithms able to efficiently discriminate tumour patients from non-tumour patients. We then validated the results using mass spectrometry and biochemical analysis of samples. For the 36 patients across three independent cohorts, the method identified tumour patients with high sensitivity and identification as high as 100% (no false positives) with declared subjects at-risk, for sporadic cancer onset, by intermediate values of PS. This assay could impact on cancer risk management, individual's diagnosis and/or help clarify risk in healthy populations.

Patient adherence in following a prescribed diet and micronutrient supplements after laparoscopic sleeve gastrectomy: our experience during 1 year of follow-up.

BACKGROUND: One of the most effective surgeries for sustainable weight loss in morbidly obese patients is laparoscopic sleeve gastrectomy (LSG). The present study aimed to assess the adherence of LSG patients with respect to following post-operative dietary requirements and micronutrient supplementation, as well as to investigate their perceived barriers in achieving optimal adherence. METHODS: Retrospective data analysis was performed (3, 6, 9 and 12 months after LSG) using the medical records of 96 morbidly obese patients who had undergone LSG at our institution during 2011-2013. Data collected from patient records were: adherence to prescribed diet; adherence to prescribed consumption of fruit, vegetables, legumes and cereals; use of prescribed micronutrient supplements; and barriers to diet and micronutrient therapy adherence. Data were analysed using spss, version 14.0 (SPSS Inc., Chicago, IL, USA). RESULTS: At 3, 6, 9 and 12 months post-LSG, the rates of patient non-adherence to a prescribed diet were 39%, 45%, 51% and 74%, respectively. In particular, there was a low consumption of fruit, vegetables, legumes and cereals compared to the post-surgery prescription. In addition, the rates of patient non-adherence to prescribed micronutrient supplements at 3, 6, 9 and 12 months post-LSG were 43%, 51%, 59% and 67%, respectively. The main reasons for patient non-adherence to diet were poor self-discipline (72%) and poor family support (11%) whereas difficulty swallowing pills or capsules (61%) and cost (20%) were reported as the main barriers to post-LSG adherence. CONCLUSIONS: Morbidly obese patients who have undergone LSG do not follow exactly the post-operative dietary guidelines, including micronutrient therapy.

Ecdysis period of Rhodnius prolixus head investigated using phase contrast synchrotron microtomography.

Microtomography using synchrotron sources is a useful tool in biological imaging research since the phase coherence of synchrotron beams can be exploited to obtain images with high contrast resolution. This work is part of a series of works using phase contrast synchrotron microtomography in the study of Rhodnius prolixus head, the insect vector of Chagas' disease, responsible for about 12,000 deaths per year. The control of insect vector is the most efficient method to prevent this disease and studies have shown that the use of triflumuron, a chitin synthesis inhibitor, disrupted chitin synthesis during larval development and it's an alternative method against insect pests. The aim of this work was to investigate the biological effects of treatments with triflumuron in the ecdysis period (the moulting of the R. prolixus cuticle) using the new imaging beamline IMX at LNLS (Brazilian Synchrotron Light Laboratory). Nymphs of R. prolixus were taken from the Laboratory of Biochemistry and Physiology of Insects, Oswaldo Cruz Foundation, Brazil. Doses of 0.05mg of triflumuron were applied directly to the abdomen on half of the insects immediately after feeding. The insects were sacrificed 25days after feeding (intermoulting period) and fixed with glutaraldehyde. The results obtained using phase contrast synchrotron microtomography in R. prolixus showed amazing images of the effects of triflumuron on insects in the ecdysis period, and the formation of the new cuticle on those which were not treated with triflumuron. Both formation and malformation of this insect's cuticle have never been seen before with this technique.

Neuroendocrine tumors diagnosed at the Antonio Cardarelli hospital (Naples, Italy) between 2006-2009: a single-institution analysis.

Neuroendocrine tumors (NETs) are rare, with an incidence of about 5 per 100,000 inhabitants. As no study on NETs has ever been specifically conducted on the population of Campania, we performed a retrospective analysis of all newly diagnosed NETs at the Antonio Cardarelli hospital between 2006-2009. A search of the registry of the Pathology Department of the Antonio Cardarelli hospital was carried out to retrieve available data on all newly diagnosed NET cases. Two hundred and ninety-nine NET tumors were diagnosed at our Institution from January, 2006 to December, 2009. Globally, 121 patients (40% of the population) had a lung NET, while 92 patients (30% of the population) presented a GEP-NET. The most common primary tumor site varied by sex, with female patients being more likely to have a primary NET in the lung, breast or colon, and male patients being more likely to have a primary tumor in the lung. Also, twenty-three cases of breast NETs were identified, and clinical information regarding therapy and response was available for 22 patients. Our study represents a pioneering effort to provide the medical community in Campania with basic information on a large number of patients with different types of NETs. The Antonio Cardarelli hospital could greatly benefit from cooperation with other hospitals in order to become a highly specialized center for NETs in the region and Southern Italy.

[Tissue engineering of parathyroid gland]. / L'ingegnerizzazione tissutale delle cellule paratiroidee.

BACKGROUND: The postoperative hypoparathyroidism is a not rare complication after total thyroidectomy and/or total parathyroidectomy. Attempts to transplant parathyroid tissue began in 1975 with the work of Wells, but still today results are disappointing. However, with the development of tissue engineering techniques, some experimental approaches to build artificial parathyroid are been made. Bioengineered device, actively secreting PTH, for transplant in patients with iatrogenic hypoparathyroidism is unavailable. PATIENTS AND METHODS: Parathyroid cells were obtained from three chronic uremic patients in hemodialysis, operated for secondary hyperparathyroidism. Cell cultures in RPMI medium were subsequently seeded on collagen scaffold (three-dimensional matrix with slow biodegradation). Collagen is the major component of the extracellular matrix and thus is a good substrate for cell adhesion and growth. Culture media, with a low calcium concentration, were optimised to physiologically stimulate parathyroid hormone secretion. Cell cultures were morphologically observed in optical and electron (ESEM) microscopy and metabolically assayed by MTT method until the tenth week. Besides, concentration of parathyroid hormone in the culture medium has been measured for several weeks. RESULTS: After 24 hours of culture in RPMI, cells extracted from human parathyroid glands were nearly all adherent and organised in clusters to resemble the glandular organization. The cellular population consisted predominantly of parathyroid cells (90-95%). On collagen scaffolds, cells maintains an epithelial-like morphology also after 10 weeks, colonizing the scaffold surface and keeping a good proliferative rate with a discrete production of parathyroid hormone. CONCLUSION: The use of parathyroid cells extracted from patients with secondary hyperparathyroidism was certainly an appropriate choice that enabled us to achieve these results, that albeit partial bode well for the experimental in vivo animal model. The bioengineered scaffolds when implanted in the subcutaneous can avoid the dispersion of parathyroid cells, assuring also the possibility to easily remove the implant in case of complications. Our research was aimed primarily to the optimisation of PTH secreting human parathyroid cells cultures and then to the in vitro engineering of human parathyroid glands in three-dimensional collagen scaffolds.

Severe spontaneous properitoneal hemorrhage following ventral hernia repair caused by viral infection: report of a case.

The authors report a case of severe spontaneous hemorrhage in a patient who underwent surgical repair of an upper umbilical ventral hernia with placement of a polypropylene mesh. On the third postoperative day the patient experienced bleeding in the properitoneal space (above and below the mesh), which spread up to and along the retroperitoneal area, causing severe hypovolemic shock. Postoperative investigations finally identified a virus as the cause of the complication.

[Abdominal lymphoma with abscess and thoracic perforation: en-bloc resection]. / Linfoma addominale ascessualizzato e perforato in torace: resezione "en-bloc".

The authors compare a rare case of acute onset Gastric Lymphoma with that present in the literature. The patient, a white 67 year-old man, was admitted to hospital in severe general condition. On CT scan an opacity of the pleura and a subtotal collapse of the left lung associated with a mass infiltrating the diaphragm, the gastric fundus and pancreas were seen. After 48 hours from the admission an operation was performed. The abdominal mass infiltrating the stomach, the spleen and the left thorax was resected en-bloc by laparotomy. A Boulau drainage was inserted. The histology showed an high malignant, diffused, big cell lymphoma. The patient was discharged 23 days later after a regular postoperative course. Surgery can be necessary, sometime curative in gastric lymphomas while long term result and quality of life could be improved by chemotherapy.

Intercellular movement of the putative transcription factor SHR in root patterning.

Positional information is pivotal for establishing developmental patterning in plants, but little is known about the underlying signalling mechanisms. The Arabidopsis root radial pattern is generated through stereotyped division of initial cells and the subsequent acquisition of cell fate. short-root (shr) mutants do not undergo the longitudinal cell division of the cortex/endodermis initial daughter cell, resulting in a single cell layer with only cortex attributes. Thus, SHR is necessary for both cell division and endodermis specification. SHR messenger RNA is found exclusively in the stele cells internal to the endodermis and cortex, indicating that it has a non-cell-autonomous mode of action. Here we show that the SHR protein, a putative transcription factor, moves from the stele to a single layer of adjacent cells, where it enters the nucleus. Ectopic expression of SHR driven by the promoter of the downstream gene SCARECROW (SCR) results in autocatalytic reinforcement of SHR signalling, producing altered cell fates and multiplication of cell layers. These results support a model in which SHR protein acts both as a signal from the stele and as an activator of endodermal cell fate and SCR-mediated cell division.

The SHORT-ROOT gene controls radial patterning of the Arabidopsis root through radial signaling.

Asymmetric cell divisions play an important role in the establishment and propagation of the cellular pattern of plant tissues. The SHORT-ROOT (SHR) gene is required for the asymmetric cell division responsible for formation of ground tissue (endodermis and cortex) as well as specification of endodermis in the Arabidopsis root. We show that SHR encodes a putative transcription factor with homology to SCARECROW (SCR). From analyses of gene expression and cell identity in genetically stable and unstable alleles of shr, we conclude that SHR functions upstream of SCR and participates in a radial signaling pathway. Consistent with a regulatory role in radial patterning, ectopic expression of SHR results in supernumerary cell divisions and abnormal cell specification in the root meristem.

Measuring the complexity of cell cycle arrest and killing of drugs: kinetics of phase-specific effects induced by taxol.

BACKGROUND: Paclitaxel (Taxol) is known to act mainly in mitosis, interfering with microtubule dynamics, but effects on the other cells cycle phases have been reported also. However, a comparative picture of perturbation and killing in the G(1), S and G(2)M phases after drug treatment is lacking. The approach developed by our group tackles the problem of the complexity of cell cycle effects with the aid of a computer program simulating cell cycle progression and new quantities measuring cell-cycle arrest and death. METHODS: The program generates data that were compared with those given by absolute cell counts and by different flow cytometry techniques, enabling us to follow the fate of G(1) and G(2)M blocked cells either re-entering the cycle or dying, distinguishing cytostatic and cytotoxic effects. Apoptosis was analyzed in order to refine the description of cytotoxic effects. RESULTS: We estimated the number of blocked and dead cells after short-term Taxol treatments in a range of concentrations and post-drug incubation times. G(2)M block was immediately active at low concentrations but was reversible, becoming irreversible only at the highest concentrations. G(1)block became active later, allowing cell cycle progression of cells initially in G(1), but was still active 48 h post-treatment, at intermediate concentrations. S-phase delay was detected after 24 h. The death rate was much higher within G(1)than G(2)M blocked cells. CONCLUSIONS: Our analysis unraveled the complexity of cell cycle effects of the drug, and revealed the activity of G(1) checkpoint, hidden by a prompter but less cytotoxic G(2)M block.

[The color Doppler US evaluation of the ureteral jet in patients with urinary colic]. / Valutazione con eco color Doppler del getto ureterale nei pazienti con colica urinaria.

PURPOSE: To report our personal experience with color Doppler ultrasound (US) in the study of the ureterovesical jet in patients with recent renal colic. MATERIAL AND METHODS: First, the jet was studied in 10 healthy subjects and then 42 consecutive patients with urinary colic were submitted to plain radiography, which was sometimes integrated with conventional renal tomography, and real time US to detect the stone and to study the urinary tract above. Then, color Doppler function studies were carried out with transverse scans at the trigone and with the scan plane rotated on the ureterovesical junction. Retrospectively, the jet frequency, velocity, duration, volume, direction and interval were analyzed. Finally, all patients were examined with excretory urography. RESULTS: The jet had an anteromedial direction and exceeded the midline in the controls, with a peak velocity of 20-30 cm/s, mean duration of 15 s, mean frequency of 4-5 min and interjet interval 2-150 s. The jet was abnormal in the obstruction side in all renal colic patients; it was slow, continuous, decreased in volume and intensity, and prolonged in 26 patients--20 of them had incomplete lumbo-iliac ureteral obstruction and 6 pyeloureteral junction stones. The jet was diverted from its orientation in 7 subjects with intramural stones. There was no jet in 9 patients and urography demonstrated complete urinary obstruction--4 at the pyeloureteral junction and 5 at the lumbo-iliac ureter. CONCLUSIONS: Color Doppler US of the ureteral jet is a valuable tool in urinary colics because it yields in real time more pieces of functional information than radiography and B-mode US and also demonstrates the grade of urinary obstruction.