Chitosan-polyethylene oxide/clay-alginate nanofiber hydrogel scaffold for bone tissue engineering: Preparation, physical characterization, and biomimetic mineralization.

This study aimed to prepare a novel organic-mineral nanofiber/hydrogel of chitosan-polyethylene oxide (CS-PEO)/nanoclay-alginate (NC-ALG). The effects of NC particles on the mineralization and biocompatibility of the scaffold were investigated. A layer-by-layer scaffold composed of CS-PEO and NC-ALG was prepared. The morphological properties, swelling, biodegradation, and mechanical behaviors of the scaffolds were evaluated. Furthermore, scaffolds were characterized by the Fourier Transform Infrared (FTIR), the Field Emission Scanning Electron Microscope (FE-SEM), and X-Ray Diffraction (XRD) techniques. Bone-like apatite formation ability of the scaffolds was determined by the mineralization test in a simulated body fluid (M-SBF). In addition, the crystalline phase of bone-like apatite precipitates was investigated by XRD analysis. The cell compatibility of the scaffolds was also studied with osteoblastic cell line MC3T3-E1 by MTT assay. Notably, the incorporation of NC particles in CS-PEO/ALG scaffolds is suitable for bone tissue regeneration which enhances bone-like apatite formation. Further, the hemolysis and MTT assays demonstrated that CS-PEO/NC-ALG scaffold was compatible and safe for MC3T3 cells.

Fracture analysis of healthy and osteoporotic femora using clinical CT images, phantomless densitometry, and linear FE method.

Computational fracture analysis has become a growing branch of orthopedic research. Particularly, the associated methods provide reliable tools for the analysis of 3D CT-based models of bone. This paper reports the results of such analyses for 15 human femora (healthy and osteoporotic) under different loading orientations (85 different analysis cases). A new method was developed for the calculation of the density distribution in the models from ordinary clinical CT images without calibration phantom. This method, along with a strain-energy-based linear finite element (FE) analysis scheme, was used to predict the fracture strength and pattern of 10 cadaveric femora, for which the mechanical testing results and calibrated FE models were already available. The very good agreement and consistency between different sets of results showed the reliability and accuracy of the new density calibration method, as well as the linear analysis scheme. Accordingly, the method was applied to five new clinical images, gathered from two clinics that used different scanners with different protocols. The strength and fracture pattern of each one of these specimens were analyzed under 15 different loading conditions. A consistent behavior was found for variation of the fracture load and pattern of all specimens with the loading orientations, while very clear contrasts were observed between the strength amplitudes of healthy and osteoporotic specimens. The proposed methods can be easily applied to ordinary daily (even archived) clinical CT scans to conduct fast and reliable fracture analysis of human femora for general bone research and opportunistic studies of osteoporosis and trauma.

A 21.3%-Efficiency Clipped-Sinusoid UWB Impulse Radio Transmitter With Simultaneous Inductive Powering and Data Receiving.

An ultra-wide-band impulse-radio (UWB-IR) transmitter (TX) for low-energy biomedical microsystems is presented. High power efficiency is achieved by modulating an LC tank that always resonates in the steady state during transmission. A new clipped-sinusoid scheme is proposed for on-off keying (OOK)-modulation, which is implemented by a voltage clipper circuit with on-chip biasing generation. The TX is designed to provide a high data-rate wireless link within the 3-5 GHz band. The chip was fabricated in 130 nm CMOS technology and fully characterized. State-of-the-art power efficiency of 21.3% was achieved at a data-rate of 230 Mbps and energy consumption of 21pJ/b. A bit-error-rate (BER) of less than 10 -6 was measured at a distance of 1 m without pulse averaging. In addition, simultaneous wireless powering and VCO-based data transmission are supported. A potential extension to a VCO-free all-wireless mode to further reduce the power consumption is also discussed.

Pelvic retroperitoneal pleomorphic hyalinizing angiectatic tumor: A case report and review of literature.

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare tumor of the soft tissue, usually located in lower extremities. There are rarely tumors reported in other anatomic locations. Herein, we report retroperitoneal PHAT in a male patient. A 41-year-old man was referred to our clinic due to an incidentally found retroperitoneal mass. Computed tomography (CT) scan showed a solid hypoechoic lesion containing fat component and calcified elements measuring about 80*72*45 mm in the right lower quadrant (RLQ) of the abdomen. Magnetic resonance imaging (MRI) showed circumscribe lesion measuring about 60 x 48 mm with partial enhancement and fat component. In pelvic exploration, a large mass was found that had encased the right external iliac artery and vein. Therefore, the mass and its surrounding iliac vessels were excised and removed en block. Then, the external iliac vessels were reconstructed with Gortex graft. No recurrence was found in 1 month and 3 months post-operation follow up. We report a pelvic retroperitoneal PHAT as a rare location of this tumor. It seems that PHAT must be considered in differential diagnosis in patients with soft tissue tumors in the pelvic cavity.

Assessment of Three-Phasic CT Scan Findings of Cirrhosis Due to Primary Sclerosing Cholangitis Versus Cryptogenic Cirrhosis.

BACKGROUND: The CT findings of cirrhosis caused by primary sclerosing cholangitis (PSC) differ from cryptogenic cirrhosis. PSC could become complicated with biliary cirrhosis and cholangiocarcinoma. This study aimed at augmenting the information on the role of the three-phasic-abdominopelvic CT scan in PSC. MATERIAL AND METHODS: A total of 185 CT scans were retrospectively reviewed, including 100 patients with cryptogenic cirrhosis and 85 patients with PSC-cirrhosis. Different morphologic criteria were compared, including segmental atrophy/hypertrophy, hepatic contour, portal-hypertension, perihilar lymphadenopathy, biliary tree dilatation, gallbladder appearance. Inflammatory-bowel-disease (IBD) and cholangiocarcinoma frequency, presence of perihilar lymph nodes (LNs), and their size during end-stage PSC cirrhosis are investigated. RESULTS: Six findings occur more frequently with PSC than those diagnosed with cryptogenic cirrhosis. Modified caudate/right lobe (m-CRL) ratio >0.73, moderate and severe lobulated liver contour, lateral left lobe atrophy, over distended gallbladder (GB), biliary tree dilatation and wall thickening, and LN sizes were higher in PSC patients as compared to cryptogenic cirrhosis (P < 0.005). Ascites and portosystemic collateral formations were significant in cryptogenic cirrhosis compared to PSC patients (P < 0.005). Cholangiocarcinoma frequency in PSC patients was 14.7%, and the frequency of inflammatory bowel disease (IBD) was 57.6%. Further, 22.4% of the patients were diagnosed with IBD and PSC simultaneously. The LN number and size in PSC patients were not different between those with or without cholangiocarcinoma. CONCLUSION: Using three-phasic CT scans and PSC characteristics could be considered as an additional suggestion besides pathology measures. Diagnosis of PSC based on histological findings could be a last resort due to its invasive essence and specific characteristics of PSC in imaging.

Tibial Tunnel Preparation in Posterior Cruciate Ligament (PCL) Reconstruction. A Technical Tip to Lessen the Stress.

BACKGROUND: The purpose of this study was to introduce a technical tip for the preparation of tibial tunnel in a posterior cruciate ligament (PCL) reconstruction to reduce the chance of popliteal artery injury and duration of the surgery. METHODS: This study included 18 patients who underwent PCL reconstructions at Imam Khomeini University Hospital, Tehran, Iran, between 2016 and 2017. In all patients, the PCL tibial aimer device was inserted from the anteromedial portal and its tip aimed 8-9 mm below shiny white fibers in PCL facet. Subsequently, the smooth guide pin was inserted from anteromedial tibial cortex and advanced just to the posterior cortex but not through it based on the measurement of tibial tunnel length. Thereafter, the reaming was done over the guide pin. As the pin was engaged in the posterior cortex, it was assured that it would not run before the reamer to the popliteal fossa. The pin was removed when the reamer touched the posterior cortex, and the reaming continued until reamer's head appeared in the PCL facet. Other steps of standard arthroscopic PCL reconstruction were done in this study. All patients were subjected to computed tomography scans. RESULTS: The mean age of the patients and the mean duration of surgery were 25±3 years and 95 min, respectively. There was no vascular injury, and the position of the tibial tunnel in all cases was accurate. Moreover, the mean distance between the centers of the tibial tunnel to champagne-glass drop-off of the posterior cortex of tibia was obtained at 7.42 mm (range: 4.6-10.4 mm). CONCLUSION: This study showed that avoiding the penetration of posterior cortex of the tibia by means of the pin during tibial tunnel preparation for PCL reconstruction is a safe, reproducible, and time-saving technique. This technique eliminates the need for fluoroscopy during the procedure.

Entrapment of uropathogenic E. coli cells into ultra-thin sol-gel matrices on gold thin films: A low cost alternative for impedimetric bacteria sensing.

Bacterial infections are causing worldwide morbidity and mortality. One way to limit infectious outbreaks and optimize clinical management of infections is through the development of fast and sensitive sensing of bacteria. Most sensing approaches are currently based on immunological detection principles. We report here on an impedimetric sensor to selectively and sensitive detect uropathogenic E. coli cells (E. coli UTI89) using artificial recognition sites. We show here the possibility to imprint the rod-shape structure of E. coli UTI 89 into ultra-thin inorganic silica coatings on gold electrodes in a reproducible manner. A linear range from to 1 × 100 -1 × 104 cfu mL-1 is obtained. With a detection limit for E. coli UTI89 below 1 cfu mL-1 from five blank signals (95% confidence level) and excellent selective binding capabilities, these bacterial cell imprinted electrodes brings us closer to a low cost specific bacterial recognition surfaces.

Renal pseudomass: be aware of splenorenal fusion.

Splenosis is the heterotopic implantation of splenic tissue that usually occurs in a previous major abdominal trauma or splenectomy setting. However, splenorenal fusion is an uncommon entity, categorised as a developmental anomaly. There have been several confirmed cases in the literature. Despite some helpful imaging features, it can be easily misdiagnosed as a neoplastic renal mass, resulting in unnecessary nephrectomy. Here we presented a case of splenorenal fusion in an elderly female patient, which was initially misdiagnosed as renal cell carcinoma in sonography. More specific imaging modalities and biopsy are helpful in suggesting the correct diagnosis.

Electrochemical Methodologies for the Detection of Pathogens.

Bacterial infections remain one of the principal causes of morbidity and mortality worldwide. The number of deaths due to infections is declining every year by only 1% with a forecast of 13 million deaths in 2050. Among the 1400 recognized human pathogens, the majority of infectious diseases is caused by just a few, about 20 pathogens only. While the development of vaccinations and novel antibacterial drugs and treatments are at the forefront of research, and strongly financially supported by policy makers, another manner to limit and control infectious outbreaks is targeting the development and implementation of early warning systems, which indicate qualitatively and quantitatively the presence of a pathogen. As toxin contaminated food and drink are a potential threat to human health and consequently have a significant socioeconomic impact worldwide, the detection of pathogenic bacteria remains not only a big scientific challenge but also a practical problem of enormous significance. Numerous analytical methods, including conventional culturing and staining techniques as well as molecular methods based on polymerase chain reaction amplification and immunological assays, have emerged over the years and are used to identify and quantify pathogenic agents. While being highly sensitive in most cases, these approaches are highly time, labor, and cost consuming, requiring trained personnel to perform the frequently complex assays. A great challenge in this field is therefore to develop rapid, sensitive, specific, and if possible miniaturized devices to validate the presence of pathogens in cost and time efficient manners. Electrochemical sensors are well accepted powerful tools for the detection of disease-related biomarkers and environmental and organic hazards. They have also found widespread interest in the last years for the detection of waterborne and foodborne pathogens due to their label free character and high sensitivity. This Review is focused on the current electrochemical-based microorganism recognition approaches and putting them into context of other sensing devices for pathogens such as culturing the microorganism on agar plates and the polymer chain reaction (PCR) method, able to identify the DNA of the microorganism. Recent breakthroughs will be highlighted, including the utilization of microfluidic devices and immunomagnetic separation for multiple pathogen analysis in a single device. We will conclude with some perspectives and outlooks to better understand shortcomings. Indeed, there is currently no adequate solution that allows the selective and sensitive binding to a specific microorganism, that is fast in detection and screening, cheap to implement, and able to be conceptualized for a wide range of biologically relevant targets.

CMOS neurotransmitter microarray: 96-channel integrated potentiostat with on-die microsensors.

A 8 × 12 array of integrated potentiostats for on-CMOS neurotransmitter imaging is presented. Each potentiostat channel measures bidirectional redox currents proportional to the concentration of a neurochemical. By combining the current-to-frequency and the single-slope analog-to-digital converter (ADC) architectures a total linear dynamic range of 95 dB is achieved. A 3.8 mm × 3.1 mm prototype fabricated in a 0.35 µm standard CMOS technology was integrated with flat and 3D on-die gold microelectrodes and an on-chip microfluidic network. It is experimentally validated in in-situ recording of neurotransmitter dopamine.

The evaluation of cisplatin effect on tubular function in children on chemotherapy.

The dose limiting side effect of cisplatin is nephrotoxicity. The aim of this study was to investigate tubular function in children who have received cisplatin and forced diuresis. We performed a cohort study on 20 children under 15 years of age with various type of malignancy on cisplatin-based chemotherapy. Twenty-four-hour urine was collected in three periods: before the first, third, and fifth doses of cisplatin administration to check urine for sodium (Na), magnesium (Mg), uric acid, creatinine (Cr), phosphorus (P), calcium (Ca), beta-2 microglobulin, and N-acetyl-beta-D-glucosaminidase (NAG) levels. At the same time, blood samples were taken to check serum Cr, Na, Mg, Ca, P, and uric acid levels. Then, we compared the mean of glomerular filtration rate (GFR); fraction excretions (FE,%) of Na, Mg, and uric acid; tubular phosphorous reabsorption (TPR,%), 24-hour urine Ca (mg); urine beta-2 microglobulin (mcg/mL); and NAG (IU/L) in three periods of cisplatin administration. The FE of Na, Mg, and urine beta-2 microglobulin increased after administration of cisplatin but TPR, FE, uric acid, and NAG decreased in the 2nd and 3rd period compared to 1st period. GFR revealed a little change that was not significant. Urine calcium was decreased significantly in the second and third periods of cisplatin administration. Since the patients were hydrated for forced diuresis and received magnesium sulfate to prevent nephrotoxicity, we did not see significant tubular dysfunction. But we saw that urine calcium excretion decreased after cisplatin injection without any change in serum calcium in spite of preventive measures.

16-channel CMOS impedance spectroscopy DNA analyzer with dual-slope multiplying ADCs.

We present a 16-channel, mixed-signal CMOS DNA analyzer that utilizes frequency response analysis (FRA) to extract the real and imaginary impedance components of the biosensor. Two computationally intensive operations, the multiplication and integration required by the FRA algorithm, are performed by an in-channel dual-slope multiplying ADC in the mixed-signal domain resulting in minimal area and power consumption. Multiplication of the input current by a digital coefficient is implemented by modulating the counter-controlled duration of the charging phase of the ADC. Integration is implemented by accumulating output digital bits in the ADC counter over multiple input samples. The 1.05 mm×1.6 mm prototype fabricated in a 0.13 µm standard CMOS technology has been validated in prostate cancer DNA detection. Each channel occupies an area of only 0.06 mm² and consumes 42 µW of power from a 1.2 V supply.