Does movement variability increase or decrease when a simple wrist task is performed during acute wrist extensor muscle pain?

Purpose

The goal of complex tasks can be maintained despite variability in the movements of the multiple body segments involved in the task (VAR_elements). This variability increases in acute pain and may enable the nervous system to search for less painful/injurious movement options. It is unclear whether VAR_elements increases when pain challenges simple tasks with fewer movement options, yet maintain successful attainment of the goal. We hypothesised that during acute pain related to a simple movement: (1) the task goal would be maintained; (2) VAR_elements would be increased; and (3) if VAR_elements increased during pain, it would decrease over time.

Methods

Movements of the right wrist/forearm were recorded with a three-dimensional motion analysis system and during a repetitive radial-ulnar deviation task between two target angle ranges (the task goal). We measured success of attaining the goal (repetitions that reached the target range and total absolute error in degrees), and variability in the motion of wrist flexion–extension and forearm pronation–supination (VAR_elements). Fourteen healthy participants performed the task in one session before, during, and after wrist extensor muscle pain induced with hypertonic saline, and in another session without pain.

Results

The task goal was maintained during acute pain. However, VAR_elements in other motion planes either reduced (pronation–supination) or did not change (flexion–extension). Thus, variability of task elements is constrained, rather than increased, in simple tasks.

Conclusions

These data suggest the nervous system adapts simple tasks with limited degrees of freedom by reduction of VAR_elements rather than the increase observed for more complex tasks.     

Application of a low-pressure differential filtration technique to suspensions of red blood cells

The paper describes a low-pressure 2 cm H₂O, 5μm nuclepore filtration system for assessing red blood cell flexibility in suspensions of native plasma. Details are given of the white cell removal technique and filter handling methods for improved repeatability. Calibration of the system and filters using physiological saline controls is detailed and the advantages of a constant-pressure system are discussed. Data on filtration rates from normal controls and diabetics are given. Comparison of thisin votro system with literature data onin vivo systems is made.     

Magnetic resonance imaging anatomy and morphometry of lumbar intervertebral foramina to guide safe transforaminal subarachnoid punctures

Percutaneous transforaminal lumbar punctures (TFLPs) offer alternative access routes to the lumbar subarachnoid cistern. Safe fluoroscopic insertion of a needle through a lumbar intervertebral foramen (IVF) should ideally avoid the exiting spinal nerve and surrounding vascular pedicles. A crescentic region in the posterior aspect of IVF is the conventional position for needle placement during TFLP, but the underlying anatomic basis for this has not been evaluated fully. To enhance TFLP safety, we defined the morphometry of normal lumbar IVFs and precise locations of neurovascular structures in the IVF posterior crescent. We retrospectively reviewed high-resolution T2-weighted lumbar spine magnetic resonance images of 40 normal adults to establish normative dimensions of each IVF from L1 to L5 bilaterally. We segmented the IVF posterior crescent into three parts, and within each, measured the areas occupied by neurovascular structures. We statistically correlated the presence or absence of neurovascular structures in each crescent segment using a chi-square test. The mean morphometrics for all 304 IVFs in 10 males and 30 females of similar ages were: area 115.3 ± 29.5 mm²; height 18.0 ± 2.4 mm; and width at mid-disc level 5.6 ± 2.1 mm. We found a significant association between crescent segment and presence or absence of neurovascular structures (χ² = 95.9, p < .001). A post-hoc calculation of adjusted standardized residuals identified a significant association between the middle crescent segment and absence of neurovascular structures. Thus, the middle segment of the IVF posterior crescent is significantly most devoid of neurovascular structures, and more often would be the safest target for needle placement during TFLP.     

Anatomical bases of percutaneous surgery for calculi in horseshoe kidney

Summary Horseshoe kidney is a renal fusion which combines three anatomic abnormalities: ectopia, malrotation and vascular changes. These anomalies can be recognised separately to varying degrees in unfused kidneys. Necessary modifications of the standard technique for percutaneous nephrolithotomy (PNL) are directly deducible from analysis of the anatomic data of the imaging of horseshoe kidneys. We report our experience with 5 patients (7 kidneys) who underwent PNL for calculi in horseshoe kidneys. The percutaneous approach was performed under ultrasound and fluoroscopic monitoring. In situ disintegration by ultrasonic lithotripsy and nephrostomy drainage were necessary in all cases. Modifications of the standard PNL procedure are related to the anatomic changes. The lower abdominal position of a horseshoe kidney necessitates upper or middle calyceal puncture, while the malrotation necessitates a more posterior puncture. Monitoring of the puncture needle by fluoroscopy as it is advanced postero-anteriorly is more difficult and the risk of the surgeon's hand entering the radiation path is increased. The renal pelvis is deep and a long endoscope may be required. Aberrant segmental vessels may create potential hazards. The majority of problems in location can be avoided by use of an ultrasonically guided needle. Percutaneous nephrolithotomy is the treatment of choice for calculi in horseshoe kidneys for the following reasons: the high incidence of recurrent lithiasis in horseshoe kidney and the complexity of repeated surgical approaches diminish the acceptable results of open surgery; difficulties in focussing on the calculi and drainage problems militate against the success of extracorporeal shock wave lithotripsy (ESWL); PNL has a good success rate and the least morbidity.Work presented at the 1st European Association of Clinical Anatomy congress, Brussels, Belgium, September 9–10, 1991     

C2‐Symmetric Zirconocenes for High Molecular Weight Amorphous Poly(propylene)

Details of the preparation and polymerization behavior of two chiral zirconocene catalysts are presented. The results of experimental and molecular‐mechanics evaluation of their stereoselectivity with respect to liquid‐propene polymerization are compared with those of a related catalyst system. The elastic properties of the obtained amorphous poly(propylene), due to the presence of small γ‐form crystallites, are compared with those of a high‐molecular weight atactic poly(propylene) obtained in the presence of a C_2v catalyst.     

Anthropomorphic simulator for minimally invasive epicardial access procedures

We have developed a prototype, in?vitro anthropomorphic model for simulating pressure-guided, subxiphoid access procedures done to enable minimally invasive epicardial cardiac procedures including treatments for ventricular tachycardia. Life-size replicas of the heart and lungs were modelled using anatomically accurate surrogates. The dynamic pressure–frequency profiles of simulated pericardial fluid surrounding the water-pumped replica heart were measured and validated against previously acquired human intrapericardial pressure observations (Pearson's r?=?0.88, p?<?0.001). In replicating access procedures for approaching and entering the pericardial space, the system produced physiologically appropriate pressure measurements at each intermediate point along the needle's insertion pathway. Details of construction and performance are presented and discussed.     

Current knowledge onChlamydia pneumoniae,strain TWAR,an important cause of pneumonia and other acute respiratory diseases

This article reviews current knowledge ofChlamydia pneumoniae strain TWAR, a newly recognizedChlamydia organism that causes acute respiratory infection, especially atypical pneumonia. Information is included on the microbiology, classification and laboratory diagnosis of the organism. Details of a series of studies of both endemic and epidemic respiratory infections are reviewed to present information on both the clinical and epidemiological characteristics of infection with strain TWAR. Laboratory studies of antibiotic sensitivity and recommendations for treatment are presented.     

The use of ultrasound improves the accuracy of epidural needle placement in cadavers

Purpose

To investigate whether epidural-prepuncture ultrasound imaging improves the accuracy and quality of epidural needle placement or not?

Methods

By recruiting 15 cadavers, a total of 90 epidural needle punctures to access epidural space in study group with the help of ultrasound imaging at lumbar and thoracic spinal segments were attempted. A similar number of punctures in a control group were also performed without ultrasound imaging involving the intervertebral spaces adjacent to the ones used for ultrasound guided punctures. The accuracy of needle tip placement was ascertained with the help of computed axial tomography. Six variables: puncture depth and needle angle, procedure time, number of attempts per space, steps in needle advances, number of bony contacts and number of spaces attempted, were studied and compared among the groups.

Results

The accuracy of epidural needle placement and quality of the procedure in study group were superior to the control group.

Conclusions

The pre-procedure ultrasound imaging enhances the accuracy and quality of epidural needle placement.     

Larval stages of digenetic trematodes ofTheodoxus jordani (Sowerby 1836) snails from Yarmouk River,Jordan

Two types of cercariae are described from the freshwater prosobranchTheodoxus jordani (Sowerby 1836) collected from the Yarmouk River during 1982: a tail-less cercaria belonging to themutabile group and a microcercous cercaria belonging to theCercaria brachyura group. These two cercariae were given the namesCercaria theodoxi I andC. theodoxi II, respectively. Details are presented on the morphology and behaviour of the cercariae as well as on their development within the snail. The relationships between these cercariae and adult trematodes reported from Jordan are discussed.     

Description of <Emphasis Type="Italic">Sarcocystis anasi</Emphasis> sp. nov. and <Emphasis Type="Italic">Sarcocystis albifronsi</Emphasis> sp. nov. in birds of the order Anseriformes

On the basis of the already published morphological, 18S rDNA, 28S rDNA data (Kutkienė et al., Parasitol Res 99:562–565, 2006; Parasitol Res 102:691–696, 2008; Parasitol Res 104:329–336, 2009), and ITS-1 region investigation results of sarcocysts presented in this paper, Sarcocystis albifronsi sp. nov. from the white-fronted goose (Anser albifrons) and Sarcocystis anasi sp. nov. from the mallard duck (Anas platyrhynchos) are described.     

Is the prevalence of Stenotrophomonas maltophilia isolation and nosocomial infection increasing in intensive care units?

The study presented here was conducted over a period of 4 years (2001–2004) to investigate changes in the number of S. maltophilia isolates detected per 1,000 patient days and to look at the incidence density of nosocomial infections caused by S. maltophilia. The analysis was based on data provided by 34 German intensive care units participating continuously in the national project “Surveillance of Antimicrobial Use and Resistance in ICUs”; 31 of these ICUs reported nosocomial infections to the German infection surveillance system, KISS, during the study period.     

Practice of percutaneous needle autopsy; a descriptive study reporting experiences from Uganda

Background

Percutaneous needle autopsy can overcome a number of barriers that limit the use of complete autopsies. We performed blind-and ultrasound guided needle autopsies in HIV-infected adults in Uganda. In this study we describe in detail the methods we used, the ability of both procedures to obtain sufficient tissue for further examination and the learning curve of the operators over time.

Methods

If written informed consent was granted from the next of kin, we first performed a blind needle autopsy, puncturing brain, heart, lungs, liver, spleen and kidneys using predefined surface marking points. We then performed an ultrasound guided needle autopsy puncturing heart, liver, spleen and kidneys. The number of attempts, expected success and duration of the procedure were noted. A pathologist read the slides and indicated if the target tissue was present and of sufficient quality for pathological review. We report the predicted and true success rates, compare the yield of blind to ultrasound guided needle biopsies and evaluate the failure rate over time.

Results

Two operators performed 96 blind needle autopsies and 95 ultrasound guided needle autopsies. For blind needle biopsies true success rates varied from 56-99% and predicted success rates from 89-99%. For ultrasound guided needle biopsies true success rates varied from 72-100% and predicted success rates from 84-98%. Ultrasound guidance led to a significantly higher success rate in heart and left kidney. A learning curve was observed over time with decreasing failure rates with increasing experience and a shorter duration of the needle autopsy.

Conclusion

Needle autopsy can successfully obtain tissue for further pathological review in the vast majority of cases, with a decrease in failure rate with increasing experience of the operator. The benefit of ultrasound guidance will depend on the population, the disease and organ of interest and the local circumstances. Our results justify further evaluation of needle autopsies as a method to establish a cause of death.

     

Computer implementation in the reconstruction of 2-D flow velocity fields in ultrasound Doppler color imaging

Doppler color imaging can easily render flow information within the vessels and simultaneously provide anatomic information for diagnostic purposes. However, the angle dependence problem of the Doppler velocity measurement is a significant barrier for continuing progress toward quantitative clinical applications of this technology. This paper presents a method and the computer implementation for reconstruction of the 2-D flow velocity field (angle independent) in ultrasound Doppler color imaging. Formulae for deriving angle independent velocity amplitude and angle direction from the color images acquired with a linear array transducer are given. The hardware configuration of the data acquiring and processing system is described. Major considerations in the development of algorithms, especially the strategies for reducing the computation time are presented.     

Real time volumetric ultrasound imaging system

A real time volumetric ultrasound imaging system has been developed for medical diagnosis. The scanner produces images analogous to an optical camera and supplies more information than conventional sonograms. Potential medical applications include improved anatomic visualization, tumor localization, and better assessment of cardiac function. The system uses pulse-echo phased array principles to steer a two-dimensional array transducer of 289 elements in a pyramidal scan format. Parallel processing in the receive mode produces 4992 scan lines at a rate of approximately 8 frames/second. Echo data for the scanned volume is presented as projection images with depth perspective, stereoscopic pairs, multiple tomographic images, or C-mode scans.     

Adamantinoma‐like Ewing sarcoma of the parotid gland: Cytopathologic findings and differential diagnosis

Adamantinoma‐like Ewing sarcoma (AES) is a rare variant of Ewing sarcoma family of tumors (EFTs), primarily affecting bone and soft tissue. AES has mixed features of Ewing sarcoma (ES)/primitive neuroectodermal tumor (PNET) and adamantinoma with a complex immunoprofile and EWSR1 gene rearrangements. Herein, we report a 72‐year‐old male who presented with left parotid mass, right neck mass and thyroid nodules. Fine needle aspiration of the left parotid mass displayed nests of monotonous epithelioid cells with basaloid features in a background of small round blue cells and lymphocytes. AES can involve head and neck region and is characterized by groups of primitive small round blue cells admixed with groups of epithelioid cells with amphophilic cytoplasm and focal squamous differentiation. The proportion of these components can be variable, creating diagnostic challenges, particularly in unusual anatomic sites such as the parotid gland. However, when additional material is available, CD99 and/or FLI1 immunostains need to be included for diagnostic confirmation.     

Transcriptional signatures associated with rubella virus-specific humoral immunity after a third dose of MMR vaccine in women of childbearing age

Multiple factors linked to host genetics/inherent biology play a role in interindividual variability in immune response outcomes after rubella vaccination. In order to identify these factors, we conducted a study of rubella-specific humoral immunity before (Baseline) and after (Day 28) a third dose of MMR-II vaccine in a cohort of 109 women of childbearing age. We performed mRNA-Seq profiling of PBMCs after rubella virus in vitro stimulation to delineate genes associated with post-vaccination rubella humoral immunity and to define genes mediating the association between prior immune response status (high or low antibody) and subsequent immune response outcome. Our study identified novel genes that mediated the association between prior immune response and neutralizing antibody titer after a third MMR vaccine dose. These genes included the following: CDC34; CSNK1D; APOBEC3F; RAD18; AAAS; SLC37A1; FAS; and JAK2. The encoded proteins are involved in innate antiviral response, IFN/cytokine signaling, B cell repertoire generation, the clonal selection of B lymphocytes in germinal centers, and somatic hypermutation/antibody affinity maturation to promote optimal antigen-specific B cell immune function. These data advance our understanding of how subjects’ prior immune status and/or genetic propensity to respond to rubella/MMR vaccination ultimately affects innate immunity and humoral immune outcomes after vaccination.     

Occasional comment: Genentech and George Hardy

A “bingo” model is one in which the pattern of survival of a system is determined by whichever of several components, each with its own particular distribution for survival, fails first. The model is motivated by the study of lifespan in animals. A number of properties of such systems are discussed in general. They include the use of a special criterion of skewness that probably corresponds more closely than traditional measures to what the eye observes in casually inspecting data. This criterion is the ratio, r(h), of the probability density at a point an arbitrary distance, h, above the mode to that an equal distance below the mode. If this ratio is positive for all positive arguments, the distribution is considered positively asymmetrical and conversely. Details of the bingo model are worked out for several types of base distributions: the rectangular, the triangular, the logistic, and by numerical methods, the normal, lognormal, and gamma.     

Manganese dioxide depolarizer for biomedical electrodes

The electrochemical and toxicological characteristics of manganese dioxide (MnO₂) have been described. Details of the construction and testing of surface MnO₂ electrode are presented. The reported data and the results of tests confirm that a MnO₂ electrode sufficiently stable and free from polarization effects can be constructed.     

Impact of the clinical ultrasound elective course on retention of anatomical knowledge by second‐year medical students in preparation for board exams

Ultrasound has been integrated into a gross anatomy course taught during the first year at an osteopathic medical school. A clinical ultrasound elective course was developed to continue ultrasound training during the second year of medical school. The purpose of this study was to evaluate the impact of this elective course on the understanding of normal anatomy by second‐year students. An anatomy exam was administered to students enrolled in the clinical ultrasound elective course before the start of the course and after its conclusion. Wilcoxon signed ranks tests were used to determine whether exam scores changed from the pre‐test to the post‐test. Scores from two classes of second‐year students were analyzed. Students who took the elective course showed significant improvement in the overall anatomy exam score between the pre‐test and post‐test (P < 0.001). Scores for exam questions pertaining to the heart, abdomen, upper extremity, and lower extremity also significantly improved from the pretest to post‐test (P < 0.001), but scores for the neck and eye showed no significant improvement. The clinical ultrasound elective course offered during the second year of medical school provided students with an important review of key anatomical concepts while preparing them for board exams. Our results suggested that more emphasis should be placed on head and neck ultrasound to improve student performance in those areas. Musculoskeletal, abdominal, and heart ultrasound labs were more successful for retaining relevant anatomical information. Clin. Anat. 28:156–163, 2015. © 2014 Wiley Periodicals, Inc.     

Interventional MRI‐guided local delivery of agents into swine bile duct walls using MR‐compatible needle‐integrated balloon catheter system

The purpose of this study was to investigate the feasibility of interventional MRI‐guided local agent delivery into pig common bile duct (CBD) walls using a newly designed MR‐compatible, needle‐integrated balloon catheter system. We first designed a needle‐integrated balloon catheter system that comprised of a 22 G MR‐compatible Chiba biopsy needle and a conventional 12 mm × 2 cm balloon catheter. Under fluoroscopy guidance, a custom needle–balloon system was positioned in the target CBD via a transcholecystic access. T₁‐weighted MRI was used to localize and reposition the needle–balloon system in the target. A 0.5 mL mixture of motexafin gadolinium (MGd) and trypan blue dye as well as 5‐fluorouracil was delivered into the CBD wall through the needle–balloon system. Post‐infusion T₁‐weighted MRI was obtained and contrast‐to‐noise ratios (CNRs) of CBD walls of pre‐ and post‐MGd–blue infusions were compared by a paired t‐test. In addition, post‐infusion x‐ray cholangiography was achieved to evaluate the potential injuries of CBDs by the needle–balloon system. Subsequent histologic analysis was performed to correlate and confirm the imaging findings. A post‐infusion cholangiogram did not show any extravasation of contrast agent, indicating no procedure‐related damage to the CBDs. MRI demonstrated clear enhancement of the target bile duct walls infused with MGd–trypan blue dye with average penetration depth of 4.7 ± 1.2 mm and an average MGd perfusion length of 21 ± 1.5 mm in the bile ducts and their surrounding tissues. The average CNR of the post‐infusion bile ducts was significant higher than that of the pre‐infusion bile ducts (110.6 ± 22 versus 5.7 ± 2.8, p < 0.0001). Histology depicted the blue dye staining and red fluorescence of MGd through the target CBD walls, which was well correlated with the imaging findings. It is feasible to use the new MR‐compatible, needle‐integrated balloon catheter system for intrabiliary local agent delivery into CBD walls under MRI guidance, which may open new avenues for efficient management of pancreatobiliary malignancies using MR‐guided interventional oncology. Copyright © 2015 John Wiley & Sons, Ltd.