[Dynamic investigation of nutritional risk in patients with malignant tumor during hospitalization]

Objective: To prospectively investigate the changes in nutritional status of patients with malignant tumors during hospitalization by using nutritional risk screening (NRS2002), and to analyze the correlation between the nutritional status and clinical outcomes . Methods: This was a prospective and parallel research done by multi-center collaboration from 34 hospitals in China from June to September 2014.Hospitalized patients with malignant tumors inthese departments (Department of Gastroenterology, respiratory medicine, oncology, general surgery, thoracic surgery and geriatrics)were investigated. Only the patients with age≥ 18 years and hospitalization time between 7-30 days were included. During hospitalization, the physical indexes of human bodywere measured, and the NRS 2002 scores, and monitored the nutritional support at the time points of admission and 24 hours before discharge were recorded.And whether there was a nutritional risk in hospitalized patients and its association with clinical outcomes were investigated. Results: A total of 2 402 patients with malignancies were enrolled in this study. Seventy fourpatients who did not complete NRS2002 were eliminated, and 2 328 patients were included. The number of the main diseases was the top five, including 587 cases of colorectal cancer, 567 cases of lung cancer, 564 cases of gastric cancer, 146 cases of esophageal cancer, and 119 cases of liver tumor. At the time of discharge, compared with admission, the BMI, body weight, grip and calf circumferences of patients with malignant tumor were significantly decreased (P<0.05). The total protein, albumin, prealbumin and hemoglobin were significantly lower than those at admission (P<0.05). In 2 328 patients who were completed nutritional risk screening, the rate of malnutrition at admission was 11.1% (BMI =18.5, 258/2 328) and the rate of malnutrition at discharge was 10.9% (BMI =18.5, 254/2 328), there were no significant differences (χ(2)=0.019 7, P=0.888). There were 1 204 patients with nutritional risk at admission (51.7%, NRS2002 score≥3)and 1 352 patients with nutritional risk at discharge (58.1%, NRS2002 score≥3), with significant differences (χ(2)=49.9, P<0.001). The incidence of nutritional risk in patients with colorectal, stomach, and lung tumors at discharge was significantly higher than that at admission (P<0.05). The infective complications and other complications of patients with nutritional risk were significantly greater than those without nutritional risk at admission and at discharge.ICU hospitalization stay of patients with nutritional risk was increased significantly than those without nutritional risk at admission(P=0.042). Hospitalization expenses of patients with nutritional risk was increased significantly than those of patients without nutritional risk at discharge(P<0.01). Conclusion: The patients with malignant tumor have a higher incidence rate of malnutrition at both admission and discharge and malnutritionhas correlation with adverse clinical outcomes.The aboveindicators did not improve significantly at discharge.Doctors should pay more attention to the nutritional status (screening and evaluation)of patients before discharge and use appropriate and adequate nutrition support in order to prevent the weight loss and improve the life quality of patients.

A new method for CE-EC determination of mercaptopurine (MP) in a PMMA biochip with on-chip gold nano-electrode ensemble (GNEE) working and decouple electrodes

This paper presents a new method for CE-EC determination of Mercaptopurine (MP), one of the most important medicines for inflammatory bowel disease (IBD) and acute lymphoblastic leukemia (ALL) treatment, in a PMMA-based microfluidic chip. A simple and reliable process for preparing the template of gold nanoelectrode ensemble (GNEE) and fabricating the integrated microfluidic chip is reported in the present study. The use of GNEE electrodes for both electric current decoupling and signal sensing in the proposed CE-EC chip not only enhances the signal response but also decreases the background noise during detection. Results show that a good detection limit of 100 nM for detecting mercaptopurine is achieved with the proposed method. In addition, the measured results also shows a good linear response between the detected CE-EC signals and the concentration of MP within the range of 100 nM-10 mM (R2 = 0.989). The proposed microchip device provides a novel and fast detection method for mercaptopurine analysis.

Immunodetection of pentamer and modified C-reactive protein using surface plasmon resonance biosensing

In clinical practices, the examination of pentamer C-reactive protein (pCRP) is commonly used as a prognostic indicator of the risk of a patient developing cardiovascular disease (CVD). Structural modification of pCRP produces a modified CRP (mCRP) which exhibits different biological activities in the body. In recent years, mCRP has come to be regarded as a more powerful inducer than pCRP, and hence mCRP measurement has emerged as an important indicator for assessing the risk of developing CVD. The surface plasmon resonance (SPR) biosensing technique can be employed to increase the detection accuracy and real-time response when sensing pCRP or mCRP. In this study, three monoclonal antibodies (Mabs), C8, 8D8, and 9C9, are immobilized on a protein G layer for subsequent CRP detection. The experimental results reveal that the Mab C8 reacts with both pCRP and mCRP, the Mab 8D8 with pCRP, and the Mab 9C9 with mCRP. No false signals caused by non-specific binding are observed. When detecting pCRP using Mab C8, the SPR bioassay provides sufficient sensitivity to evaluate whether or not a patient is at risk of developing CVD. SPR biosensing provides a viable and accurate approach for the real-time evaluation of pCRP and mCRP levels, and is therefore of considerable benefit in clinical examinations of CPR.

A novel ultrahigh-resolution surface plasmon resonance biosensor with an Au nanocluster-embedded dielectric film

The detection performance of conventional surface plasmon resonance (SPR) biosensors is limited to a 1 pg/mm(2) surface coverage of biomolecules, and consequently, such sensors struggle to detect the interaction of small molecules in low concentrations. The present study is attempted to propose the use of a novel SPR biosensor with Au nanoclusters embedded in a dielectric film to achieve a 10-fold improvement in the resolution performance. A co-sputtering method utilizing a multi-target sputtering system is used to fabricate the present dielectric films (SiO(2)) with embedded Au nanoclusters. It is shown that the sensitivity of the developed SPR biosensor can be improved by adjusting the size and volume fraction of the embedded Au nanoclusters in order to control the surface plasmon effect. The present gas detection and DNA hybridization experimental results confirm that the proposed Au nanocluster-enhanced SPR biosensor provides the potential to achieve an ultrahigh-resolution detection performance of approximately 0.1 pg/mm(2) surface coverage of biomolecules.

The effect of magnitudes and duration of pressure on cerebral cortex in a rat model

The aim of this biomechanical study was to investigate the pressure-time-damage relationship on the cerebral cortex using a rat model. During brain surgery, additional cortical injuries induced by traction have been an important clinical issue. A total of 84 rats underwent a unilateral craniectomy, and conduction by hydrostatic pressure loading through a modified central venous pressure device with various combinations of magnitudes ranging from 0.5 to 10 cm H2O and duration from 0.5 to 20 minutes was then performed. Histopathological examination has exhibited three patterns of clustered, spotted damaged neurons and undamaged neuron. Two best-fitted exponential curves were derived from the data to establish the damaged, critical and tolerable loadings responsible for the neuron viability. This research provides information to enhance understanding of the additional cortex injuries induced by traction. Furthermore, the results may have implications in providing clinical guidance and/or development of alarm systems for minimising cortical damage during surgery.

Head injury in facial impact--a finite element analysis of helmet chin bar performance

The chin bar of a motorcycle helmet protects the rider from facial and head injuries. To evaluate the protective performance of chin bars against head injuries from facial impacts, an explicit finite element method was used to simulate the Snell Memorial Foundation test and a proposed drop test. The maximum acceleration and Head Injury Criterion (HIC) were employed to assess the impact-absorbing capability of the chin bar. The results showed that the proposed approach should be more practical than the Snell test, and provided more information for improving the chin bar design to protect against head injuries. The shell stiffness was important in determining the protective ability of the chin bar, but a chin bar with only an outer shell and comfort foam offered inadequate protection. An energy-absorbing liner was essential to increase the protective performance of the chin bar and the liner density should be denser than that used in the cranial portion of the helmet. For the chin bar with energy-absorbing liner, a shell design that is less stiff would provide better protection.

Outcome of coronary revascularization in patients on renal dialysis

Previous retrospective studies showed high periprocedure mortality rate and poor outcome after percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) among renal dialysis patients. The purpose of this study was to compare mortality and clinical event rates in renal dialysis patients after PTCA or CABG. We identified 252 patients from the Emory Cardiovascular Database who were on dialysis and who received PTCA (122 patients) or CABG (130 patients) at Emory University Hospital and Crawford W. Long Hospital between March 1987 and December 1997. Baseline and angiographic characteristics, in-hospital, and 1-year outcome were compared between the 2 groups. Left main disease and 3-vessel coronary artery disease were significantly more common in the CABG group. There was a higher periprocedure and in-hospital mortality in the CABG group (6.9% vs 1.6%, p = 0.04). Patients in the PTCA group underwent repeat revascularization 11 times more frequently within 1 year (22% vs 2%). At 1 year, mortality was 23% in the PTCA group and 27% in the CABG group, with no statistical difference between the 2 groups. This nonrandomized comparison reveals that PTCA and CABG can be performed in selected renal dialysis patients with an acceptable in-hospital major complication rate; however, 1-year mortality remains high in dialysis patients after coronary revascularization. Therefore, attempts at improving outcome in dialysis patients should focus on the prevention and treatment of coronary artery disease before they require coronary revascularization.

Kinematics of cervical spine discectomy with and without bone grafting: quantitative evaluation of late fusion in a sheep model

OBJECTIVE

This study was conducted to evaluate the kinematic response of late fusion results for cervical spine discectomies with and without bone grafting.

MATERIALS AND METHODS

Fifteen Barbados Black Belly sheep underwent sham operations (Group A, n = 5), C2-C3 discectomies only (Group B, n = 5), and C2-C3 discectomies with autologous iliac bone grafting (Group C, n = 5). Ten months after surgery, the animals were killed. Fresh ligamentous spines (C1-C5) were subjected to the relevantly applied loads through a loading frame attached to the C1. Each vertebra (from C2 to C4) was attached with a set of three infrared light-emitting diodes to record the spatial location relating to each load application using a Selspot II system (Selcom Selective Electronics, Inc., Valdese, NC). The load-deformation data of the C2-C3 and C3-C4 motion segments were recorded and analyzed for the three groups.

RESULTS

At the C2-C3 motion segment, the results indicated that Group B displayed larger motion ranges of rotation and lateral bending loads than did the other two groups. Significantly larger motion ranges of rotation loads were found in Group B than in Group C (P<0.05, for both comparisons). In contrast, Group C had the smallest motion ranges of flexion, lateral bending, and rotation loads. At the C3-C4 motion segment, both groups that had undergone discectomies had a significantly larger motion range of flexion load compared with Group A (P<0.05, for both comparisons). A significant increase in the motion range of right axial rotation was found in Group B (P<0.05), but not in Group C, compared with Group A. Group B exhibited larger motion ranges responding to all six tested loads than did Group C.

CONCLUSION

The results indicate that anterior fusion after C2-C3 cervical discectomies, regardless of the presence or absence of bone grafting, decreases the motion range of flexion load at the C2-C3 motion segment, and contrary data were seen at the C3-C4 motion segment. For axial rotation loads, discectomies without bone grafting resulted in increased motion ranges of both C2-C3 and C3-C4 motion segments whereas discectomies with bone grafting did not. The data may have clinical relevance regarding the role of bone grafting in cases of cervical spine disease.

Intramedullary implant of plasma-sprayed hydroxyapatite coating: an interface study

An intramedullary implant model in the canine femora was developed to evaluate the mechanical and histological responses between cancellous bone and plasma-sprayed hydroxyapatite coatings (HACs) on ti-6A1-4V implants, with 12- and 24-week follow-ups. HACs of different thicknesses were investigated. Results of the mechanical testings revealed that after 24 weeks of implantation, the mean shear strength (2.49 +/- 0.12 MPa) of the 50 microns HACs was significantly higher (p < 0.05) than that of the 200 microns HACs (1.44 +/- 0.19 MPa). However, using backscattered electron images (BEIs) throughout all the implant periods, no substantial histological variations in the extent of new bone apposition between the two HACs were observed. Occasionally, solution-mediated disintegration of the 50 microns HAC was found 24 weeks postimplantation. Histomorphometric studies from the BEIs demonstrated that for both HACs the percentage of the direct HAC-cancellous bone contact was approximately 50% at 12 weeks and 75% at 24 weeks. After the mechanical tests, the 200 microns HACs had fracture sites either inside the coating layers or at the HAC-titanium interfaces, which might explain why the mechanical performance of the 200 microns HACs was inferior to that of the 50 microns HACs even though both HACs had the same histological behaviors.

Recanalization of the left atrial appendage demonstrated by transesophageal echocardiography

Closure of the fibrillating left atrial appendage has been recommended during mitral valve operations to help prevent thrombus formation and systemic embolization postoperatively. We report recanalization of the appendage orifice in 6 patients after surgical closure by pursestring suturing at the time of mitral valve replacement. Transesophageal echocardiography demonstrated disruption of the closure line and partial recanalization of the sutured orifice with relatively high velocity flow between the left atrial body and the appendage.

Diagnosis of esophageal varices by transesophageal echocardiography: a mimicker of aortic disease

The use of transesophageal echocardiography is well established in the emergency department diagnosis of traumatic aortic diseases. It has very high sensitivity and specificity compared with those of other tests. The physician performing transesophageal echocardiography should be aware of conditions that can mimic aortic pathologic conditions, thus leading to an incorrect diagnosis. We report a case in which the presence of previously undiagnosed esophageal varices mimicked traumatic aortic disease.

Photoelastic stress analysis of mandibular posterior cantilevered pontic

The quasi-3D technique of photoelastic stress analysis was used to evaluate the stresses of mandibular posterior cantilevers for distal terminal abutments at various levels of periodontal support. The stress concentration index was selected to compare each model. The periodontal support of terminal abutment and the length of pontic must be considered, when a cantilever fixed partial denture is anticipated.

Mechanical property analysis of small bone fixators

The purpose of this study is to establish a database and to compare mechanical properties between various types of small bone fixators. Hollow maple dowels are uniformly produced to simulate small bones in this study. Furthermore, transverse osteotomy, transverse osteotomy with 2 mm gap, and 45 degrees oblique osteotomies are created to simulate stable, unstable, and spiral fractures. Each fracture pattern is then approximated with four types of fixators: (1) Aesculap mini external fixator, (2) mini A-O plate and screw, (3) cross pin, and (4) self-assembled mini external fixator. Finally, tension, torsion, and bending tests are performed with INSTRON. In three different fracture patterns, dorsal plating has the strongest tensile rigidity and lateral bending rigidity. In stable and unstable fractures, Aesculap mini external fixator has the strongest torsional rigidity. However, mini A-O plate has the strongest torsional rigidity in 45 degrees oblique fractures. In stable fractures, dorsal plating, lateral plating, and mini external fixator all have good anterior bending rigidity without significant differences. Nevertheless, only lateral plating and mini external fixator show good anterior bending rigidity in unstable and 45 degrees oblique fractures. Except in torsional rigidity, Aesculap mini external fixator is not significantly stiffer than the self-assembled external fixator. As expected, cross pin is the weakest fixator. Differences in mechanical stiffiness between the four types of small bone fixators are provided in this study. Additionally, one should also consider the indication when choosing a proper fixator. Complication rate can then be lowered to achieve successful surgery in treating small bone fractures.

Stress analysis of four-unit fixed bridges on abutment teeth with reduced periodontal support

The variable properties of photoelastic models and the difficulty of fabrication of the model limit experimental designs. The 'material fringe value' is introduced into the definition of the 'stress concentration index' by multiplying the fringe orders. Three levels of periodontal support in three photoelastic models (nine cases) were compared quantitatively by determining the stress concentration induced in periodontium by point loading vertically on a span of the fixed partial denture of four units length. The results indicate that comparison among photoelastic models is possible and useful. The stress concentration effects produced by the second molar were more prominent and determinant than that by the first premolar in the periodontium of the abutments.

Fat in the prediction of bone strength of porcine lumbar vertebrate by quantitative computed tomography

The influence of fat content on quantitative computed tomography (QCT) values was studied using porcine lumbar vertebrae as a model. A total of 72 cancellous bone columns, prepared from 18 vertebrae, underwent QCT examination before and after defatting. Mechanical testing and ashing were performed to obtain the ultimate strength and bone mineral content. The ultimate strength was calculated as a power function of apparent density using linear regression on a log-log plot and the power coefficient was 1.88. QCT values were positively correlated with bone density. QCT values of defatted specimens correlated much better with ultimate strength than those of fresh specimens. The average fat content was 27.2%. The QCT values decreased linearly with increasing fat content with a slope of 7.9 mg/cm3/% fat and a correlation coefficient of 0.65. The results provided basic data for the calibration of the machine and the principles for the interpretation of QCT values excluding the fat influence.

Study of low-temperature thermoplastic modified custom-molded cervical orthosis for cervical spine fixation

The purpose of this experiment is to use a low-temperature thermoplastic material (Aquaplast) to make a modified custom-molded cervical orthosis. Sixteen normal young subjects who do not have previous cervical problems are tested in this study. This modified orthosis is applied on these volunteers so that external fixation of the cervical spine can be tested. Various roentgenograms for cervical flexion and extension, as well as neutral position and lateral bending, are taken to determine the fixation property of the cervical spine. A study of rotation of the cervical spine is also carried out through goniometer measurements. This clinical study proves that this low-temperature thermoplastic cervical orthosis provides good fixation for the cervical spine, especially in flexion and rotation, but is not suitable for C1- and C2-injured patients.

[Quantification of acetabular coverage in normal adult]

Quantification of acetabular coverage is important and can be expressed by superimposition of cartilage tracings on the maximum cross-sectional area of the femoral head. A practical Autolisp program on PC AutoCAD has been developed by us to quantify the acetabular coverage through numerical expression of the images of computed tomography. Thirty adults (60 hips) with normal center-edge angle and acetabular index in plain X ray were randomly selected for serial drops. These slices were prepared with a fixed coordination and in continuous sections of 5 mm in thickness. The contours of the cartilage of each section were digitized into a PC computer and processed by AutoCAD programs to quantify and characterize the acetabular coverage of normal and dysplastic adult hips. We found that a total coverage ratio of greater than 80%, an anterior coverage ratio of greater than 75% and a posterior coverage ratio of greater than 80% can be categorized in a normal group. Polar edge distance is a good indicator for the evaluation of preoperative and postoperative coverage conditions. For standardization and evaluation of acetabular coverage, the most suitable parameters are the total coverage ratio, anterior coverage ratio, posterior coverage ratio and polar edge distance. However, medial coverage and lateral coverage ratios are indispensable in cases of dysplastic hip because variations between them are so great that acetabuloplasty may be impossible. This program can also be used to classify precisely the type of dysplastic hip.

An in-vivo measurement and analysis of viscoelastic properties of the spinal cord of cats

An in-vivo experimental technique was employed to determine the linear and nonlinear characteristics of viscoelastic properties of the spinal cord of anesthetized cats. The stress relaxation and recovery curves were reproducible in a group of cat experiments. The data of linear viscoelastic properties were used to develop a power law model with Boltzmann's convolution integral. The model was capable of predicting a prolonged stress relaxation and recovery curve. For larger deformation, the results were quantified using a nonlinear analysis of viscoelastic response of the spinal cord under the uniaxial experiment.

Biomechanics of spinal cord injury

This article summarizes the biomechanical relationship of the spinal column to load stresses with respect to column failure, and the resulting associated central nervous system injury. In addition, it presents pertinent animal research, which has focused onto the development standardized animal spinal cord injury model.

Stress-strain measurement of the spinal cord of puppies and their neurological evaluation

An in-vivo experiment was developed to identify the biorheological properties of the spinal cord of puppies under uriaxial deformation. For strain less than 4.5%, the ratio between stress and strain was about 2.65 x 106 dyne/limbs of the puppies were recoverable after the spinal cord segment at L1 was stretched once by 10-50%.

Stress-strain relationship and neurological sequelae of uniaxial elongation of the spinal cord of cats

An in vivo experimental method was developed to measure the mechanical or rheological properties of the spinal cord of anesthetized cats. This novel approach resulted in measurements of the tensile force in the cord and the modulus of the spinal cord tissue under longitudinal elongation. Both sensory and motor function of the cats recovered within a week after a spinal cord segment had been stretched by a 50% elongation.

Biomechanical and neurological response of the spinal cord of a puppy to uniaxial tension

An in-vivo experimental method was developed to measure the stress-strain relationship of a spinal cord segment of anesthetized puppies. A pseudo Young's modulus was defined for the linear region followed by a nonlinear rheological behavior of finite strain. Both the sensory response and motor function of the puppies were fully recovered within the 5 days after the spinal cord segment in the first lumbar region was elongated once by 50 percent or less. The usefulness of the in-vivo experiments was further elaborated by demonstrating the large artifacts that could be associated in an in-vitro experiment.