A Novel Real-Time Autonomous Crack Inspection System Based on Unmanned Aerial Vehicles

Traditional methods on crack inspection for large infrastructures require a number of structural health inspection devices and instruments. They usually use the signal changes caused by physical deformations from cracks to detect the cracks, which is time-consuming and cost-ineffective. In this work, we propose a novel real-time crack inspection system based on unmanned aerial vehicles for real-world applications. The proposed system successfully detects and classifies various types of cracks. It can accurately find the crack positions in the world coordinate system. Our detector is based on an improved YOLOv4 with an attention module, which produces 90.02% mean average precision (mAP) and outperforms the YOLOv4-original by 5.23% in terms of mAP. The proposed system is low-cost and lightweight. Moreover, it is not restricted by navigation trajectories. The experimental results demonstrate the robustness and effectiveness of our system in real-world crack inspection tasks.

Transmission mitigation of COVID-19: Exhaled contaminants removal and energy saving in densely occupied space by impinging jet ventilation

The pandemic of COVID-19 and its transmission ability raise much attention to ventilation design as indoor-transmission outstrips outdoor-transmission. Impinging jet ventilation (IJV) systems might be promising to ventilate densely occupied large spaces due to their high jet momentum. However, their performances in densely occupied spaces have rarely been explored. This study proposes a modified IJV system and evaluates its performance numerically in a densely occupied classroom mockup. A new assessment formula is also proposed to evaluate the nonuniformity of target species CO₂. The infector is assumed as the manikin with the lowest tracer gas concentration in the head region. The main results include: a) Indoor air quality (IAQ) in the classroom is improved significantly compared with a mixing ventilation system, i.e., averaged CO₂ in the occupied zone (OZ) is reduced from 1287 ppm to 1078 ppm, the OZ-averaged mean age of air is reduced from 439 s to 177 s; b) The mean infection probability is reduced from 0.047% to 0.027% with an infector, and from 0.035% to 0.024% with another infector; c) Cooling coil load is reduced by around 21.0%; d) Overall evaluation indices meet the requirements for comfortable environments, i.e., the temperature difference between head and ankle is within 3 °C and the OZ-averaged predictive mean vote is in the range of -0.5 - 0.5; e) Thermal comfort level and uniformity are decreased, e.g., overcooling near diffuser at ankle level. Summarily, the target system effectively improves IAQ, reduces exhaled-contaminant concentration in head regions, and saves energy as well.

Development of Fixed-Wing UAV 3D Coverage Paths for Urban Air Quality Profiling

Due to the ever-increasing industrial activity, humans and the environment suffer from deteriorating air quality, making the long-term monitoring of air particle indicators essential. The advances in unmanned aerial vehicles (UAVs) offer the potential to utilize UAVs for various forms of monitoring, of which air quality data acquisition is one. Nevertheless, most current UAV-based air monitoring suffers from a low payload, short endurance, and limited range, as they are primarily dependent on rotary aerial vehicles. In contrast, a fixed-wing UAV may be a better alternative. Additionally, one of the most critical modules for 3D profiling of a UAV system is path planning, as it directly impacts the final results of the spatial coverage and temporal efficiency. Therefore, this work focused on developing 3D coverage path planning based upon current commercial ground control software, where the method mainly depends on the Boustrophedon and Dubins paths. Furthermore, a user interface was also designed for easy accessibility, which provides a generalized tool module that links up the proposed algorithm, the ground control software, and the flight controller. Simulations were conducted to assess the proposed methods. The result showed that the proposed methods outperformed the existing coverage paths generated by ground control software, as it showed a better coverage rate with a sampling density of 50 m.

Proactive Guidance for Accurate UAV Landing on a Dynamic Platform: A Visual-Inertial Approach

This work aimed to develop an autonomous system for unmanned aerial vehicles (UAVs) to land on moving platforms such as an automobile or a marine vessel, providing a promising solution for a long-endurance flight operation, a large mission coverage range, and a convenient recharging ground station. Unlike most state-of-the-art UAV landing frameworks that rely on UAV onboard computers and sensors, the proposed system fully depends on the computation unit situated on the ground vehicle/marine vessel to serve as a landing guidance system. Such a novel configuration can therefore lighten the burden of the UAV, and the computation power of the ground vehicle/marine vessel can be enhanced. In particular, we exploit a sensor fusion-based algorithm for the guidance system to perform UAV localization, whilst a control method based upon trajectory optimization is integrated. Indoor and outdoor experiments are conducted, and the results show that precise autonomous landing on a 43 cm × 43 cm platform can be performed.

[Long-term therapeutic effects and liver fibrosis changes with direct-antiviral therapy in HIV/HCV co-infected patients]

Objective: To investigate the long-term characteristic changes of virus, immune status, and liver fibrosis markers in human immunodeficiency virus (HIV)/hepatitis C virus (HCV) co-infected patients after receiving direct-antiviral agents (DAAs). Methods: HIV/HCV co-infected patients who visited the Guangzhou Eighth People's Hospital, Guangzhou Medical University from May 2014 to December 2019 were selected as the research subjects. The changes of virological response rate, peripheral blood CD4(+)T lymphocyte level and serological markers of liver fibrosis (APRI score and FIB-4 index) were observed during 144 weeks of follow-up course after the end of DAAs treatment. Kruskal-Wallis test was used for statistical approach. Results: A total of 103 cases were included in the study. There were 87 males (87.5%), with a median age of 44 years. Sustained virological response rate at 12 weeks (SVR12) after DAAs treatment was 97.6%, and the SVR during the entire follow-up period was at least 95.9%. Compared with baseline, CD4(+)T lymphocyte count were significantly increased equally at 12 weeks (Z = -2.283, P = 0.022), 24 weeks (Z = -3.538, P < 0.001), 48 weeks (Z = -3.297, P = 0.001), 96 weeks (Z = -3.562, P < 0.001), and 144 weeks (Z = -2.842, P = 0.004). APRI score (Z = -6.394, P < 0.001) and FIB-4 index (Z = -2.528, P = 0.011) were significantly lower than baseline at week 4 of DAAs treatment, and thereafter remained at a low level, without further declination. Conclusion: HIV/HCV co-infected patients can maintain high SVR for a long time, acquire good immune reconstitution, and significantly improve liver fibrosis after DAAs treatment.

Learning-Based Autonomous UAV System for Electrical and Mechanical (E&M) Device Inspection

The inspection of electrical and mechanical (E&M) devices using unmanned aerial vehicles (UAVs) has become an increasingly popular choice in the last decade due to their flexibility and mobility. UAVs have the potential to reduce human involvement in visual inspection tasks, which could increase efficiency and reduce risks. This paper presents a UAV system for autonomously performing E&M device inspection. The proposed system relies on learning-based detection for perception, multi-sensor fusion for localization, and path planning for fully autonomous inspection. The perception method utilizes semantic and spatial information generated by a 2-D object detector. The information is then fused with depth measurements for object state estimation. No prior knowledge about the location and category of the target device is needed. The system design is validated by flight experiments using a quadrotor platform. The result shows that the proposed UAV system enables the inspection mission autonomously and ensures a stable and collision-free flight.

Clinical epidemiology and outcome of HIV-associated talaromycosis in Guangdong, China, during 2011-2017

OBJECTIVES

Talaromycosis is an invasive mycosis endemic to Southeast Asia. This study aimed to investigate the epidemiology, clinical features and prognostic factors of HIV-associated talaromycosis in Guangdong, China.

METHODS

We retrospectively evaluated HIV patients hospitalized with histopathology- or culture-confirmed talaromycosis between 2011 and 2017. Factors associated with poor prognosis were identified using logistic regression.

RESULTS

Overall, 1079 patients with HIV-associated talaromycosis were evaluated. Both the number and prevalence of talaromycosis among HIV admissions increased from 125 and 15.7% in 2011 to 253 and 18.8% in 2017, respectively, reflecting the increase in HIV admissions. Annual admissions peaked during the rainy season between March and August. Common clinical manifestations included fever (85.6%), peripheral lymphadenopathy (72.3%), respiratory symptoms (60.8%), weight loss (49.8%), skin lesions (44.5%) and gastrointestinal symptoms (44.3%). Common laboratory abnormalities were hypoalbuminaemia (98.6%), anaemia (95.6%), elevated aspartate aminotransferase level (AST) (76.9%), elevated alkaline phosphatase level (55.8%) and thrombocytopenia (53.7%). The median CD4 count was 9 cells/μL. Talaromyces marneffei was isolated from blood and bone marrow cultures of 66.6% and 74.5% of patients, respectively. The rate increased to 86.6% when both cultures were performed concurrently. At discharge, 14% of patients showed worsening conditions or died. Leucocytosis, thrombocytopenia, elevated AST, total bilirubin, creatinine and azole monotherapy independently predicted poor prognosis.

CONCLUSIONS

The incidence of HIV-associated talaromycosis has increased in Guangdong with the high HIV burden in China. Skin lesions were seen in less than half of patients. Induction therapy with azole alone is associated with higher mortality. Findings from this study should help to improve treatment of the disease.

Multi-scale mechanical investigation of articular cartilage suffered progressive pseudorheumatoid dysplasia

BACKGROUND

Progressive pseudorheumatoid dysplasia is a rare skeletal dysplasia mainly caused by abnormal autosomal recessive inheritance. Although the main function of cartilage is mechanical support and the characteristics of this disease is the degradation of AC, previous studies on it had been mainly focused on clinical and genetic aspects and the mechanical behavior of the cartilage affected by PPRD is still ambiguous. In this study, we investigate the mechanics and structure of the cartilage suffered disease at multi-scale, from individual chondrocytes to the bulk-scale tissue.

METHODS

Depth-sensing indenter were employed to investigate the mechanics of cartilage; we performed atomic force microscope nanoindentation to investigate the cell mechanics and scanning electron microscopy were used to explore the structure feature and chemical composition.

FINDINGS

The elastic modulus of chondrocytes harvested from cartilage suffered from progressive pseudorheumatoid dysplasia is significantly higher than from normal cartilage, same trend were also found in tissue level. Moreover, denser collagen meshwork and matrix calcification were also observed.

INTERPRETATION

The elastic modulus of cartilage should closely related to its denser structure and the calcification, and may potentially be an indicator for clinical diagnosis. The stiffening of chondrocytes during PPRD progression should play a rather important role in its pathogenesis.

[Real-world efficacy and safety of lopinavir/ritonavir and arbidol in treating with COVID-19 : an observational cohort study]

Objective: To evaluate the efficacy and safety of lopinavir/ritonavir (LPV/r) and arbidol in the treatment of COVID-19 in the real world. Methods: The clinical data of 178 patients diagnosed with COVID-19 admitted to Guangzhou Eighth People's Hospital were retrospectively analyzed from January 21 to February 9, 2020. According to the patient's antiviral treatment regimen, 178 patients were divided into 4 groups including LPV/r group (59 patients), arbidol group (36 patients), combination therapy with LPV/r plus arbidol group (25 patients) and the conventional treatment group without any antiviral drugs (58 patients). The main observation end points of the study was the negative conversion time of nucleic acid of the novel coronavirus (2019-nCoV) in pharyngeal swab. Results: The baseline of 4 groups before treatment was consistent and comparable. The negative conversion time of nucleic acid of the 2019-nCoV in pharyngeal swab was (10.20 ± 3.49), (10.11 ± 4.68), (10.86 ± 4.74), (8.44 ± 3.51) days separately in the LPV/r group, the arbidol group, the combination therapy group, and the conventional treatment group without significant difference (F = 2.556, P = 0.058). There was also no significant difference in the rate of negative conversion rate of 2019-nCoV nucleic acid, the improvement ration in clinical symptoms, and the improvement ration of pulmonary infection in the lung CT imaging (P> 0.05). However, a statistically significant difference was found in the proportion of deterioration changing from mild/moderate to severe/critical type at day 7 (χ(2) = 9.311, P = 0.017) as follows: the combination therapy group (24.0%, 6/25), the arbidol group ( 16.7%, 6/36), LPV/r group (5.4%, 3/56) and conventional treatment group (5.2%, 3/58). Moreover, the frequency of adverse reactions in the three groups receiving antiviral drugs was significantly higher than that in the conventional treatment group (χ(2) = 14.875, P = 0.002). Conclusions: No evidences could prove that LPV/r and arbidol could shorten the negative conversion time of novel coronavirus nucleic acid in pharyngeal swab nor improve the symptoms of patients. Furthermore, the combination usage of LPV/r and arbidol may not benefit for improving the disease. Noteworthy, the adverse reactions of the antiviral drugs should be paid careful attention during the treatment.

Perception in the Dark-Development of a ToF Visual Inertial Odometry System

Visual inertial odometry (VIO) is the front-end of visual simultaneous localization and mapping (vSLAM) methods and has been actively studied in recent years. In this context, a time-of-flight (ToF) camera, with its high accuracy of depth measurement and strong resilience to ambient light of variable intensity, draws our interest. Thus, in this paper, we present a realtime visual inertial system based on a low cost ToF camera. The iterative closest point (ICP) methodology is adopted, incorporating salient point-selection criteria and a robustness-weighting function. In addition, an error-state Kalman filter is used and fused with inertial measurement unit (IMU) data. To test its capability, the ToF–VIO system is mounted on an unmanned aerial vehicle (UAV) platform and operated in a variable light environment. The estimated flight trajectory is compared with the ground truth data captured by a motion capture system. Real flight experiments are also conducted in a dark indoor environment, demonstrating good agreement with estimated performance. The current system is thus shown to be accurate and efficient for use in UAV applications in dark and Global Navigation Satellite System (GNSS)-denied environments.

Low-protein diet improves meat quality of growing and finishing pigs through changing lipid metabolism, fiber characteristics, and free amino acid profile of the muscle

The objective of the study was to investigate the effect of feeding reduced CP, AA-supplemented diets on meat quality in growing and finishing pigs as well as the related mechanism. In experiment 1, 18 growing pigs (36.5 kg BW) were assigned randomly and fed 1 of 3 corn-soybean meal diets containing either 18% CP (normal protein, NP), 15% CP (low protein, LP), or 12% CP (very low protein, VLP). In experiment 2, 18 finishing pigs (62.3 kg BW) were allotted randomly into 1 of the following diets: 16% CP (NP), 13% CP (LP), or 10% CP (VLP). In both experiments, the LP and VLP diets were supplemented with crystalline AA to achieve equal content of standardized ileal digestible lysine, methionine, threonine, and tryptophan. At the end of each experiment, all pigs were slaughtered to collect longissimus dorsi muscle (LM) samples. Samples were used for determining meat quality, intramuscular fat (IMF) content, fatty acid composition, free AA profile, and expression of genes for myosin heavy chain isoforms. Results showed that growing and finishing pigs fed the LP diets increased (P < 0.05) redness value of LM, while finishing pigs fed the LP and VLP diets decreased (P < 0.05) the shear force values. Compared with the NP diet, growing and finishing pigs fed lower CP diets had higher (P < 0.05) contents of IMF and MUFA, and lower (P < 0.05) contents of PUFA. Besides, higher (P < 0.05) expression levels of type I and/or IIa muscle fibers were observed in LP diet-fed growing and finishing pigs, and greater concentrations of taurine and tasty AA in VLP diet-fed growing and finishing pigs. Taken together, our results indicate that low-protein diets could positively affect meat quality of growing and finishing pigs, and likely through regulation of IMF content and fatty acid composition, fiber characteristics, and free AA profile in the muscle.

Evaluation of aptamer specificity with or without primers using clinical samples for C-reactive protein by magnetic-assisted rapid aptamer selection

Aptamers with primer binding sites are necessary for the SELEX (Systematic Evolution of Ligands by EXponential enrichment) process.

A Camera-Based Target Detection and Positioning UAV System for Search and Rescue (SAR) Purposes

Wilderness search and rescue entails performing a wide-range of work in complex environments and large regions. Given the concerns inherent in large regions due to limited rescue distribution, unmanned aerial vehicle (UAV)-based frameworks are a promising platform for providing aerial imaging. In recent years, technological advances in areas such as micro-technology, sensors and navigation have influenced the various applications of UAVs. In this study, an all-in-one camera-based target detection and positioning system is developed and integrated into a fully autonomous fixed-wing UAV. The system presented in this paper is capable of on-board, real-time target identification, post-target identification and location and aerial image collection for further mapping applications. Its performance is examined using several simulated search and rescue missions, and the test results demonstrate its reliability and efficiency.

Development and Testing of a Two-UAV Communication Relay System

In the development of beyond-line-of-sight (BLOS) Unmanned Aerial Vehicle (UAV) systems, communication between the UAVs and the ground control station (GCS) is of critical importance. The commonly used economical wireless modules are restricted by the short communication range and are easily blocked by obstacles. The use of a communication relay system provides a practical way to solve these problems, improving the performance of UAV communication in BLOS and cross-obstacle operations. In this study, a communication relay system, in which a quadrotor was used to relay radio communication for another quadrotor was developed and tested. First, the UAVs used as the airborne platform were constructed, and the hardware for the communication relay system was selected and built up. Second, a set of software programs and protocol for autonomous mission control, communication relay control, and ground control were developed. Finally, the system was fully integrated into the airborne platform and tested both indoor and in-flight. The Received Signal Strength Indication (RSSI) and noise value in two typical application scenarios were recorded. The test results demonstrated the ability of this system to extend the communication range and build communication over obstacles. This system also shows the feasibility to coordinate multiple UAVs' communication with the same relay structure.

The emerging role of endothelin-1 in the pathogenesis of subchondral bone disturbance and osteoarthritis

Mounting evidence suggests reconceptualizing osteoarthritis (OA) as an inflammatory disorder. Trauma and obesity, the common risk factors of OA, could trigger the local or systemic inflammatory cytokines cascade. Inflammatory bone loss has been well documented; yet it remains largely unknown about the link between the inflammation and hypertrophic changes of subchondral bone seen in OA, such as osteophytosis and sclerosis. Amid a cohort of inflammatory cytokines, endothelin-1 (ET-1) could stimulate the osteoblast-mediated bone formation in both physiological (postnatal growth of trabecular bone) and pathological conditions (bone metastasis of prostate or breast cancer). Also, ET-1 is known as a mitogen and contributes to fibrosis in various organs, e.g., skin, liver, lung, kidney heart and etc., as a result of inflammatory or metabolic disorders. Subchondral bone sclerosis shared the similarity with fibrosis in terms of the overproduction of collagen type I. We postulated that ET-1 might have a hand in the subchondral bone sclerosis of OA. Meanwhile, ET-1 was also able to stimulate the production of matrix metalloproteinase (MMP)-1 and 13 by articular chondrocytes and synoviocytes, by which it might trigger the enzymatic degradation of articular cartilage. Taken together, ET-1 signaling may play a role in destruction of bone-cartilage unit in the pathogenesis of OA; it warrants further investigations to potentiate ET-1 as a novel diagnostic biomarker and therapeutic target for rescue of OA.

An innovative numerical approach to resolve the pulse wave velocity in a healthy thoracic aorta model

Aortic dissection and atherosclerosis are highly fatal diseases. The development of both diseases is closely associated with highly complex haemodynamics. Thus, in predicting the onset of cardiac disease, it is desirable to obtain a detailed understanding of the flowfield characteristics in the human cardiovascular circulatory system. Accordingly, in this study, a numerical model of a normal human thoracic aorta is constructed using the geometry information obtained from a phase-contrast magnetic resonance imaging (PC-MRI) technique. The interaction between the blood flow and the vessel wall dynamics is then investigated using a coupled fluid-structure interaction (FSI) analysis. The simulations focus specifically on the flowfield characteristics and pulse wave velocity (PWV) of the blood flow. Instead of using a conventional PC-MRI method to measure PWV, we present an innovative application of using the FSI approach to numerically resolve PWV for the assessment of wall compliance in a thoracic aorta model. The estimated PWV for a normal thoracic aorta agrees well with the results obtained via PC-MRI measurement. In addition, simulations which consider the FSI effect yield a lower predicted value of the wall shear stress at certain locations in the cardiac cycle than models which assume a rigid vessel wall. Consequently, the model provides a suitable basis for the future development of more sophisticated methods capable of performing the computer-aided analysis of aortic blood flows.

Bone loss at subchondral plate in knee osteoarthritis patients with hypertension and type 2 diabetes mellitus

OBJECTIVES

This study aimed to characterize subchondral bone damages of knee osteoarthritis (OA) patients in presence of the comorbidities, i.e., hypertension and type 2 diabetes mellitus (T2DM).

METHODS

A total of 43 patients with advanced stage of primary knee OA were recruited, and tibial plateau specimens were collected during surgery with informed consent. The specimens were processed for micro-CT and histological examination to assess the severity of subchondral bone damages. The presence of the comorbid disease, e.g., hypertension and T2DM, and the data on covariates, such as the age, gender and body mass index (BMI), were taken into account in a multi-variable linear regression model to explore the potential effect of the comorbidities on subchondral bone damages in knee OA after adjusting the covariates.

RESULTS

As compared to 15 subjects without the comorbidities, significant bone loss was observed at subchondral plate in 28 knee OA patients with hypertension and T2DM, in terms of the lower bone mineral density (BMD) (P = 0.034) and higher porosity (P = 0.032) on the medial portion of tibial plateau. After adjusting the age, gender and BMI, the presence of hypertension or T2DM was included in a regression model to explain in part the decreased BMD (r(2) = 0.551, P = 0.004) and increased porosity (r(2) = 0.545, P = 0.003) at subchondral plate in knee OA.

CONCLUSION

Our findings suggest the biological link between bone loss at subchondral bone plate in knee OA and the comorbid diseases, i.e., hypertension and T2DM, which prompt the needs for a large-scale cohort study to confirm the causality.

First Report of Fusarium proliferatum Causing Fruit Rot of Winter Jujube (Zizyphus jujuba) in Storage in China

Winter jujube, Zizyphus jujuba Mill., is a Chinese crop with fruit that has an extremely high nutritional value (4). In early November 2010, a severe fruit rot affecting ~20% of 1,000 kg of winter jujube fruit was observed in a storehouse in Zhengzhou, Henan province, China. The same fruit rot symptoms were found in two supermarkets in Zhengzhou in late November 2010 in ~10% of 100 kg of fruit in one supermarket and 25% of 50 kg of fruit in the other. Symptoms first appeared as small, round, pale yellow brown lesions on the fruits, 1 to 3 mm in diameter, then developed into 5- to 10-mm, sunken, brown spots, each with a pale brown margin. Three Fusarium isolates (DZF001 to DZF003) showing similar morphological characteristics were isolated from three specimens (collected from one storehouse and two supermarkets) by surface sterilizing small pieces of necrotic fruit tissue for 1 min in 2% NaOCl, washing the tissue pieces three times with sterile distilled water, and plating the pieces on potato dextrose agar (PDA). Fungal colonies for each isolate were white to light pink, and the adaxial side of each culture was pale yellow. Macroconidia were produced in pale orange sporodochia and were slender, relatively straight, three to five septa, 29.0 to 55.2 × 2.5 to 4.0 μm, with a curved apical cell and a poorly developed basal cell. Microconidia were produced in chains or false heads on synthetic nutrient-poor agar, clavate with a planar base, aseptate, and 4.5 to 8.0 × 2.5 to 3.5 μm. Conidiophores terminated in verticils of two to three phialides or monophialides. Chlamydospores were absent. The cultural and morphological characteristics were similar to those of Fusarium proliferatum (1,2). The identity of the three fungal isolates was confirmed to be F. proliferatum by DNA sequencing of the internal transcribed spacer (ITS) rDNA region (GenBank Accession Nos. JN889713 to JN889715), which were 99 to 100% homologous to those of other F. proliferatum isolates (GU066714, HQ113948, and GU363955); and the elongation factor 1-alpha (EF-1a) gene (JN889713 to JN889715), which was 99% homologous to those of other F. proliferatum isolates (FJ538244, FJ895277, and GQ848536) (3). Pathogenicity tests were conducted on 20 winter jujube fruits using a mycelial plug harvested from the periphery of a 7-day-old colony of strain DZF001, and placed on the surface of the fruit after the inoculated area of the fruit had been surface sterilized with 75% ethanol for 2 min; an equal number of fresh winter jujube fruits treated with non-colonized plugs of PDA served as the control treatment. Each jujube fruit was pricked three times with an insect needle to create three holes close together before inoculation with an agar plug. Each fruit was then enclosed in a clear plastic box with a cup of sterile distilled water to maintain high relative humidity, and held at 25°C. Symptoms similar to those originally observed on the naturally infected fruit were observed 3 days after inoculation, and the same fungus was reisolated from each of the symptomatic fruits; control fruits remained asymptomatic and no fungus was isolated from the control fruit. Koch's postulates were repeated three times with the same results. To our knowledge, this is the first report of F. proliferatum causing rot of winter jujube fruit in China. References: (1) K. Chehri et al. Saudi J. Biol. Sci. 18:341, 2011. (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual, Blackwell Publishing, 2006. (3) H. T. Phan. Studies Mycol. 50:261, 2004. (4) J. Sheng et al. Acta Hort. 620:203, 2003.

Investigation of pulsatile flowfield in healthy thoracic aorta models

Cardiovascular disease is the primary cause of morbidity and mortality in the western world. Complex hemodynamics plays a critical role in the development of aortic dissection and atherosclerosis, as well as many other diseases. Since fundamental fluid mechanics are important for the understanding of the blood flow in the cardiovascular circulatory system of the human body aspects, a joint experimental and numerical study was conducted in this study to determine the distributions of wall shear stress and pressure and oscillatory WSS index, and to examine their correlation with the aortic disorders, especially dissection. Experimentally, the Phase-Contrast Magnetic Resonance Imaging (PC-MRI) method was used to acquire the true geometry of a normal human thoracic aorta, which was readily converted into a transparent thoracic aorta model by the rapid prototyping (RP) technique. The thoracic aorta model was then used in the in vitro experiments and computations. Simulations were performed using the computational fluid dynamic (CFD) code ACE+((R)) to determine flow characteristics of the three-dimensional, pulsatile, incompressible, and Newtonian fluid in the thoracic aorta model. The unsteady boundary conditions at the inlet and the outlet of the aortic flow were specified from the measured flowrate and pressure results during in vitro experiments. For the code validation, the predicted axial velocity reasonably agrees with the PC-MRI experimental data in the oblique sagittal plane of the thoracic aorta model. The thorough analyses of the thoracic aorta flow, WSSs, WSS index (OSI), and wall pressures are presented. The predicted locations of the maxima of WSS and the wall pressure can be then correlated with that of the thoracic aorta dissection, and thereby may lead to a useful biological significance. The numerical results also suggest that the effects of low WSS and high OSI tend to cause wall thickening occurred along the inferior wall of the aortic arch and the anterior wall of the brachiocephalic artery, similar implication reported in a number of previous studies.

Electrokinetic instability effects in microchannels with and without nanofilm coatings

This paper presents a parametric experimental investigation into the electrokinetic instability (EKI) phenomenon within three different types of microfluidic device, namely T-type, cross-shaped, and cross-form with an expansion configuration. The critical electric field strength at which the EKI phenomenon is induced is examined as a function of the conductivity ratio, the microchannel width, the expansion ratio, and the surface treatment of the microchannel walls. It is found that the critical electric field strength associated with the onset of EKI is strongly dependent on the conductivity ratio of the two samples within the microfluidic device and reduces as the channel width increases. The surfaces of the microchannel walls are coated with hydrophilic or hydrophobic organic-based spin-on-glass (SOG) nanofilms for glass-based microchips. The experimental results indicate that no significant difference exists in the critical electric field strengths in the hydrophilic or hydrophobic SOG-coated microchannels, respectively. However, for a given conductivity ratio and microchannel width, the critical strength of the electric field is slightly lower in the SOG-coated microchannels than in the non-coated channels. In general, the results presented in this study demonstrate the potential for designing and controlling on-chip assays requiring the manipulation of samples with high conductivity gradients, and provide a useful general reference for avoiding EKI effects in capillary electrophoresis analysis applications.

Quantification of the pulse wave velocity of the descending aorta using axial velocity profiles from phase-contrast magnetic resonance imaging

The pulse wave velocity (PWV) of aortic blood flow is considered a surrogate for aortic compliance. A new method using phase-contrast (PC)-MRI is presented whereby the spatial and temporal profiles of axial velocity along the descending aorta can be analyzed. Seventeen young healthy volunteers (the YH group), six older healthy volunteers (the OH group), and six patients with coronary artery disease (the CAD group) were studied. PC-MRI covering the whole descending aorta was acquired, with velocity gradients encoding the in-plane velocity. From the corrected axial flow velocity profiles, PWV was determined from the slope of an intersecting line between the presystolic and early systolic phases. Furthermore, the aortic elastic modulus (Ep) was derived from the ratio of the brachial pulse pressure to the strain of the aortic diameter. The PWV increased from YH to OH to CAD (541 +/- 94, 808 +/- 184, 1121 +/- 218 cm/s, respectively; P = 0.015 between YH and OH; P = 0.023 between OH and CAD). There was a high correlation between PWV and Ep (r = 0.861, P < 0.001). Multivariate analysis showed that age and CAD were independent risk factors for an increase in the PWV. Compared to existing methods, our method requires fewer assumptions and provides a more intuitive and objective way to estimate the PWV.

Expression of Tie-1 and 2 receptors, and angiopoietin-1, 2 and 4 in gastric carcinoma; immunohistochemical analyses and correlation with clinicopathological factors

AIMS

There is strong evidence that tyrosine kinases are involved in the regulation of tumour progression, cellular growth and differentiation. Recently, many kinds of tyrosine kinase receptors have been reported, and among them Tie-1 and 2 constitute a major class. Angiopoietin (Ang)-1 is known as a ligand of the Tie-2 tyrosine kinase receptor. The aim of this study was to determine the expression profile of Tie-1 and 2 and Ang-1, 2 and 4 in gastric adenocarcinoma.

METHODS AND RESULTS

Eighty-nine cases of surgically resected human gastric adenocarcinoma were studied by immunohistochemistry. Of these, 60 (67.4%), 61 (68.5%), 69 (77.5%), 75 (84.3%), and 47 cases (52.8%) showed positive staining in the cytoplasm of carcinoma cells for the Tie-1 and 2 and Ang-1, 2 and 4 proteins, respectively. The expression of Ties and Angs was significantly correlated with several type of histological differentiation and several clinicopathological factors.

CONCLUSIONS

Ties and Angs were highly expressed in human gastric adenocarcinoma cells. These findings suggest that the Tie-Ang receptor-ligand complex is one of the factors involved in the cellular differentiation and progression of human gastric adenocarcinoma.

Multi-resolution image fusion technique and its application to forensic science

Image fusion is a process of combining two or more images into an image. It can extract features from source images, and provide more information than one image can. Multi-resolution analysis plays an important role in image processing, it provides a technique to decompose an image and extract information from coarse to fine scales. In some practical forensic examinations (such as the cartridge image check), we cannot obtain all information from just one image; on the contrary, we need information from images with difference light sources (or light ways). In this paper, we apply an image fusion method based on multi-resolution analysis to forensic science. Synthetic and real images (such as images from closed-up photography and flash photography) are used to show the capability of the multi-resolution image fusion technique.

Three-dimensional cytomorphology in fine needle aspiration biopsy of medullary thyroid carcinoma

OBJECTIVE

To elucidate three-dimensional (3-D) cytomorphology in fine needle aspiration biopsy (FNAB) of medullary thyroid carcinoma (MTC).

STUDY DESIGN

ENAB was performed on tumors from five patients with MTC. The aspirate was stained and observed under a light microscope (LM). The aspirate was also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). For transmission electron microscopy (TEM), the specimen was fixed, dehydrated, embedded in an Epon mixture, cut with an ultramicrotome, mounted on copper grids, electron doubly stained with uranium acetate and lead citrate, and observed with TEM. Findings under SEM were correlated with those under LM and TEM.

RESULTS

Under SEM, 3-D cytomorphology of MTC displayed a disorganized cellular arrangement with indistinct cell borders in three cases. The cell surface was uneven and had granular protrusions that corresponded to secretory granules observed under TEM. In one case with multiple endocrine neoplasia type IIB, there were abundant granules on the cell surface. In one case of sporadic MTC with multinucleated tumor giant cells and small cells, granular protrusions also were noted on the cell surface.

CONCLUSION

Granular protrusion was a characteristic finding in FNAB of MTC tinder SEM and might be helpful in the differential diagnosis.

Axotomy along with hypoxia enhances the neuronal NADPH-d/NOS expression in lower brain stem motor neurons of adult rats

This study was aimed to determine whether axotomy coupled with hypoxia would exert a more profound effect on injury-induced neuronal nitric oxide synthase (NOS) expression. In this connection, the vagus and the hypoglossal nerves of adult rats were transected unilaterally in the same animal, and half of the operated animals were subjected to hypoxia treatment. Both the neuronal NOS immunohistochemistry and the nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry were used to assess the neuronal NOS expression. The present results have shown that the number of NADPH-d/NOS-positive [NADPH-d/NOS(1)] neurons in the hypoglossal nucleus (HN) peaked at 14 days after axotomy, while that in dorsal motor nucleus of vagus (DMN) and nucleus ambiguus (NA) was progressively increased up to 60 days. The up-regulation of NADPH-d/NOS in HN and DMN was more pronounced in hypoxic than in normoxic animals, a feature that was not evident in the NA. Quantitative analysis showed that the number of surviving motoneurons in normoxic animals was significantly higher than those subjected to hypoxia at 14 days postaxotomy in HN and at all postaxotomy time points in DMN. The difference may be attributed to their different functional components. Since O2 deprivation leads to poor cellular function, the stronger expression of NADPH-d/NOS and the more drastic neuronal loss following nerve transection in the hypoxic animals compared with the controls suggest that hypoxia plays an important role in peripheral neuropathies in which NO is implicated.

The distribution and characterization of NADPH-d/NOS-IR neurons in the rat cuneate nucleus

Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and nitric oxide synthase (NOS) immunohistochemistry have been used to characterize the nitric oxide (NO)-containing neurons in the rat cuneate nucleus. The present results showed that NADPH-d-positive/NOS-immunoreactive (-IR) neurons were distributed in the entire rostrocaudal extent of the nucleus. In the caudal region (approximately 1-2 mm caudal to the obex), NADPH-d/NOS-IR neurons were aggregated along the dorsal area of the nucleus notably in the lateral aspect. When traced rostrally, labeled neurons were progressively reduced and the cells were randomly distributed. The labeled neurons varied from round, ovoid to spindle-shaped with a mean profile area of about 140.1+/-1.7 microm(2) (n=720). They made up 7-10% of the neuronal population in the cuneate nucleus. By immunoelectron microscopy, the immunoreaction product was deposited throughout the cytoplasm extending from the soma to the proximal and distal dendrites. Results of NADPH-d staining paralleled that of NOS immunohistochemistry. Furthermore, NADPH-d reactivity and NOS-IR were colocalized in the same neurons following double labeling. Using NADPH-d histochemistry along with anti-gamma-aminobutyric acid (GABA) and -glycine postembedding immunolabeling for identification of GABA- and glycine-IR neurons, respectively, about 33% of the NADPH-d-positive neurons contained both GABA and glycine, 26% of them contained only glycine, while 41% of them showed neither GABA nor glycine labeling. Cuneothalamic neurons (CTNs) were identified by injecting the retrograde tracer Fluorogold (FG) into the ventrobasal complex of the thalamus. Numerous FG-labeled neurons were present in the contralateral cuneate nucleus, but none were reactive for NADPH-d. The present results suggest that approximately 60% of the NADPH-d/NOS-IR neurons in the cuneate nucleus are interneurons containing GABA and/or glycine.

Afferent synaptic contacts on glycine-immunoreactive neurons in the rat cuneate nucleus

This study was aimed to clarify whether the primary afferent terminals (PATs), GABAergic terminals, and glutamatergic terminals made direct synaptic contacts with glycine-IR neurons in the cuneate nucleus of rats. In this connection, injection of the anterograde tracer WGA-HRP into brachial plexus, antiglycine preembedding immunoperoxidase, and anti-GABA, along with antiglutamate postembedding immunogold labeling, were used to identify the PATs, glycine-IR neurons, GABA-IR terminals, and glutamate-IR terminals, respectively. The present results showed that HRP-labeled PATs, immunoperoxidase-labeled glycine-IR terminals, immunogold-labeled GABA-IR, and glutamate-IR terminals made axodendritic synaptic contacts with immunoperoxidase-labeled glycine-IR neurons. The latter three presynaptic elements also formed axosomatic synapses with glycine-IR neurons. Statistical analysis has shown that the minimum diameter of the glycine-IR dendrites postsynaptic to the above-mentioned four presynaptic elements did not differ significantly. In addition, the synaptic ratio of the glutamate-IR terminals on the glycine-IR dendrites was higher than that of GABA-IR terminals. The synaptic ratio of the GABA-IR terminals on glycine-IR dendrite was in turn higher than that of the PATs and glycine-IR terminals. It is suggested that the PATs and glutamate-IR terminals on the glycine-IR neurons may be involved in subsequent postsynaptic inhibition for spatial precision of lateral inhibition. On the other hand, the GABA-IR and glycine-IR terminals which make synaptic contacts with the dendrites of glycine-IR neurons may provide a putative means for disinhibition or facilitation to maintain the baseline neuronal activity in the rat cuneate nucleus. The results of quantitative analysis suggest that glutamate act as the primary excitatory neurotransmitter, while GABA, when compared with glycine, may serve as a more powerful inhibitory neurotransmitter on glycine-IR neurons in the rat cuneate nucleus.

Somatic noxious mechanical stimulation induces Fos expression in the postsynaptic dorsal column neurons in laminae III and IV of the rat spinal dorsal horn

This study was conducted to ascertain the possible expression of Fos-like immunoreactivity (Fos-LI) in the postsynaptic dorsal column (PSDC) neurons in response to noxious mechanical stimulation of the forepaw glabrous area of normal rats. For this purpose, Fos immunohistochemistry along with Fluoro-Gold (FG) retrograde tracing was utilized. After repeated noxious pinching of the forepaw glabrous area, there was a marked increase in number of Fos-LI neurons in the dorsal horn, including Rexed's laminae III and IV, at C5-T1 spinal cord segments ipsilateral to the stimulation. Between segments C5 and T1, about 40% of the Fos-LI neurons in laminae III and IV were distributed at segment C7. In the rats subjected to the noxious pinch coupled with FG injection into the right cuneate nucleus, PSDC neurons double labeled with Fos and FG were localized in the ipsilateral laminae III and IV extending from segment C5 to T1, with about 70% of them distributed at segments C6 and C7. At segment C6 or C7, double-labeled neurons made up about 10% of the PSDC neurons that projected their axons to the cuneate nucleus. Most of the double-labeled neurons appeared fusiform with their primary dendrites projected dorso-ventrally. The present results suggest that the morphologically distinct, subclasses of PSDC neurons in spinal laminae III and IV may contribute to the central transmission of mechanical nociceptive information through the dorsal column into the cuneate nucleus.

A beta-fiber intensity stimulation of chronically constricted median nerve induces c-fos expression in thalamic projection neurons of the cuneate nucleus in rats with behavioral signs of neuropathic pain

This study was aimed to investigate the possible involvement of neurons in the cuneate nucleus (CN) in the processing of A beta afferent inputs evoked by electrical stimulation of constricted median nerve in rats with behavioral signs of neuropathic pain. Immunohistochemical localization of Fos protein was used to examine the neuronal activation, and the combination of Fos immunohistochemistry with the retrograde labeling of Fluoro-Gold (FG) injected into the ventrobasal complex of the thalamus was used to characterize the activated neurons. Two weeks after unilateral median nerve constriction injury, the rats exhibited behavioral signs of neuropathic pain in the affected forepaws. In rats after nerve injury but without electrical stimulation, some Fos-like immunoreactive (Fos-LI) neurons were detected in the dorsal horn of the seventh cervical segment (C7) but none was found in the CN. Similar features were also noted when the stimulation of the intact median nerve served as an additional control. After A beta-fiber intensity stimulation of the previously constricted median nerve, an increase in number of Fos-LI neurons occurred in the medial half of the ipsilateral C7 dorsal horn as well as in the ipsilateral CN. In the latter, the Fos-LI neurons were located in the median nerve projection territory throughout the nucleus. Most of the Fos-LI neurons were distributed in the middle region of the CN, with about 78% of them emitting FG fluorescence indicating that they were cuneothalamic projection neurons. The results of this study suggest that the dorsal column-medial lemniscal system may contribute to the transmission and modulation of A beta-fiber mediated neuropathic pain signals.

Cadaveric study of blood supply to the lower intraorbital fat: etiologic relevance to the complication of anaerobic cellulitis in orbital floor fracture

BACKGROUND AND PURPOSE

Although orbital fractures are common, orbital cellulitis rarely develops following orbital fracture. We hypothesized that compromise of the blood supply to the intraorbital fat during orbital floor fracture is responsible for this condition. The purpose of this study was to determine whether or not the lower intraorbital fat is supplied by a branch of the infraorbital artery along the orbital groove or canal on the orbital floor.

MATERIALS AND METHODS

We dissected 14 orbits from seven fixed human cadavers and 12 orbits from six fresh cadaver heads following dye injection into the maxillary artery. The sites of dye-filled vessels branching from the infraorbital artery supplying the lower intraorbital fat were measured and plotted on a two-dimensional orbital floor graph.

RESULTS

A main branch of the infraorbital artery rose through the medial orbital floor to supply the lower intraorbital fat in all of the cadaver orbits. The sites of the branching point of the vessel ranged from 0 to 5 mm (mean, 2.2 mm; n = 14) medial to the line connecting the infraorbital foramen and the infraorbital groove. The shortest distance measured from the branching point to the orbital rim ranged from 3 to 20 mm (mean, 14.1 mm; n = 14). This suggests that if orbital fracture were to occur around the infraorbital groove or canal, this vascular pedicle would be in danger of being incarcerated by bone fragments.

CONCLUSION

Our cadaveric investigation revealed that the lower intraorbital fat is supplied by a branch of the infraorbital artery along the infraorbital groove or canal on the orbital floor. This finding suggests that compromised blood supply to the intraorbital fat may cause anaerobic cellulitis or enophthalmos.

X-ray absorption studies of carbon-related materials

X-ray absorption near-edge structure (XANES) measurements have been performed on nitrogen-doped diamond films with three different dopant concentrations and iron-layer-stabilized carbon nanotube (CNT) structures with various diameters at the C K-absorption edge using the sample drain current mode. The C K-edge XANES spectra of these N-doped diamond films resemble that of the undoped diamond regardless of the dopant concentration, which suggest that the overall bonding configuration of the C atom is unaltered. N dopants are found to reduce the intensities of both the sp2- and sp3-bond-derived resonance features in the XANES spectra. On the other hand, the C K-edge XANES spectra of CNTs indicate that the intensities of the pi* and sigma* bands and the interlayer-state features vary with the diameter of the CNT. This phenomenon may be caused by the Fe-layer-catalysed bending of the graphite sheet and the interaction between C and Fe atoms.

Somatostatin-IR neurons are a major subpopulation of the cuneothalamic neurons in the rat cuneate nucleus

This study was aimed to localize and characterize the somatostatin-immunoreactive (SOM-IR) neurons in the rat cuneate nucleus (CN). By immuno-histochemistry, the SOM-IR neurons, which were widely distributed in the nucleus, were round, spindle or multiangular in shape (mean area = 226.1 +/ -3.1 microm(2), n = 1016). By electron microscopy, the neurons shared all the ultrastructural features of the cuneothalamic neurons (CTNs) which showed a slightly indented nucleus and a fairly rich cytoplasm containing well-developed Golgi apparatuses and rough endoplasmic reticulum (rER). The SOM immunoreaction product filled the cytoplasm of the neurons extending from the soma to the proximal and distal dendrites, which were postsynaptic to unlabeled boutons. In addition to soma and dendrites, SOM-IR boutons were also identified which made axodendritic synaptic contacts with SOM-IR dendrites. The SOM-IR neurons were characterized by using anti-SOM pre-embedding immunolabeling coupled with horseradish peroxidase (HRP) retrograde method, or SOM immunolabeling along with anti-glutamate, gamma-aminobutyric acid (GABA) or glycine post-embedding immunolabeling for identification of CTNs, glutamate-IR, GABA-IR and glycine-IR neurons, respectively. It was shown that more then 80% of the CTNs contained SOM and, furthermore, they contained glutamate but not GABA or glycine. On the basis of present findings, it is suggested the majority of the SOM-IR neurons in the rat CN are CTNs and that they may be involved in modulation of somatosensory synaptic transmission.

Cuneothalamic relay neurons are postsynaptic to glycine-immunoreactive terminals in the rat cuneate nucleus

This study was aimed to clarify whether the cuneothalamic relay neurons (CTNs) in the rat cuneate nucleus contained glycine or whether the neurons were modulated directly by presynaptic glycine-IR terminals. For this purpose, retrograde transport of wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP) and immunoperoxidase labelling for glycine have been used to ascertain if the CTNs in the rat are glycine-immunoreactive (glycine-IR). Our results have shown that the WGA-HRP-labelled CTNs (mean area = 318 +/- 6.5 microm(2)) were not reactive for glycine. Glycine immunoreactivity, however, was localized in some small-sized neurons (mean area = 210 +/- 6.2 microm(2)) and axon terminals associated with the CTNs. The synaptic organization between the glycine-IR terminals and CTNs was further analyzed using anti-glycine postembedding immunogold labelling. By electron microscopy, the immunogold-labelled glycine-IR terminals containing pleomorphic synaptic vesicles formed symmetrical synaptic contacts with the dendrites, dendritic spines, and somata of CTNs. Quantitative estimation showed that the mean ratios of glycine-IR terminals to total terminals associated with the soma, proximal dendrites and distal dendrites of the CTN were 49.5, 45.2, and 45.8%, respectively. The higher incidence of glycine-IR terminals on the soma, however, was not significantly different from that of the proximal and distal dendrites. Notwithstanding the above, this study has shown a large number of glycine-IR terminals making direct synaptic contacts with CTNs, suggesting that glycine is one of the important neurotransmitters involved in postsynaptic inhibition on the cuneothalamic relay neurons to modulate incoming somatosensory information from forelimb areas in the rat.

Melatonin attenuates neuronal NADPH-d/NOS expression in the hypoglossal nucleus of adult rats following peripheral nerve injury

Oxidative stress and massive production of nitric oxide (NO) have been implicated in the neuropathogenesis following peripheral nerve injury. This study was aimed to ascertain whether melatonin would exert its neuroprotective effect on the lesioned hypoglossal neurons after peripheral axotomy, since it is known to reduce the oxidative damage in a variety of experimental neuropathologies in which NO is involved. Right-sided hypoglossal nerve transection was performed in adult rats following which the animals were given two different doses of melatonin administered intraperitoneally for 3, 7, 14, 21 and 30 successive days. Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and neuronal nitric oxide synthase (nNOS) immunohistochemistry were carried out to detect the neuronal NADPH-d/NOS expression in the hypoglossal nucleus (HN). At various time intervals following axotomy, the neurons in the affected HN were induced to express NADPH-d/NOS reactivity on the lesioned side peaking at 14 days. However, the enzyme expression was markedly depressed by melatonin treatment in a dose-dependent manner in terms of frequency of labelled neurons and staining intensity. It is suggested that the suppressive effect of melatonin on NADPH-d/NOS expression may be attributed to its antioxidant properties. Hence, in consideration of therapeutic strategies for reducing the oxidative stress following peripheral nerve injury, melatonin may prove to be beneficial.

Three-dimensional cytomorphology and its relationship with clinical stage in fine needle aspiration biopsy of papillary thyroid carcinoma

OBJECTIVE

To elucidate three-dimensional (3-D) cytomorphology and its relationship with clinical stage in fine needle aspiration biopsy (FNAB) of papillary thyroid carcinoma (PTC).

STUDY DESIGN

FNAB was performed in tumors from 34 patients with PTC. The aspirate was stained and observed under a light microscope (LM). The aspirate was also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). Findings under SEM were correlated with the presentation under LM and also with clinical stage. As a control, FNAB was also performed on a normal part of the thyroid in six patients.

RESULTS

Under SEM, normal thyroid cells appeared as round, scattered cells or sheets with a uniform honeycomb cellular arrangement. In PTC, cell sheets with uniform nuclear morphology under LM usually showed a uniform cell arrangement and with distinct cell borders under SEM. Cell sheets with nuclear pleomorphism under LM usually showed a more-disorganized arrangement and with indistinct cell borders under SEM. PTC at advanced clinical stages usually presented with a disorganized cell arrangement, indistinct cell borders and loss of microvilli.

CONCLUSION

3-D cytomorphology in FNAB of PTC was related to clinical stage and might be a prognostic factor for PTC.

Scanning by DOVAM-S detects all unique sequence changes in blinded analyses: evidence that the scanning conditions are generic

The [detection of virtually all mutations]-SSCP (DOVAM-S) is a highly sensitive variant of single strand conformation polymorphism (SSCP). Mutations in the factor IX gene were used to find a set of five SSCP conditions that detects virtually all mutations. A blinded analysis of the factor IX gene in patients with hemophilia B detected 82 of 82 unique mutations. Since the method was developed and tested on the factor IX gene, it is possible that the conditions selected work more efficiently in the factor IX gene than in other genes. To test the general applicability of the conditions under which DOVAM-S detected all mutations in this gene, blinded analyses were performed in the human factor VIII and ataxia-telangiectasia (ATM) genes. Segments were amplified individually, combined into groups of 16 to 18 amplified segments and electrophoresed in five different nondenaturing conditions of varying matrices, buffers, temperatures and additives. Blinded analyses were performed in 92 samples from patients with hemophilia A (factor VIII gene) and 19 samples from A-T patients (ATM gene). Combined with an earlier blinded analysis in the factor IX gene, all of the 250 mutations and polymorphisms (180 of which are unique) were detected in both analyses. For two, three and four joint conditions, the average detection frequency ranged from 77%-97%, 91%-100% and 95%-100%, respectively. For each of the genes, one mutation may have been missed if only four conditions were used. With DOVAM-S, approximately 500 kb of autosomal sequence can be scanned in five gels with virtually 100% detection of mutations within the scanned region. The detection of 180 out of 180 unique sequence changes implies that DOVAM-S detects at least 96.5% (P = 0.03) of mutations. Blinded analyses that detect 400 unique sequence changes are required to determine that a scanning method detects at least 98.5% of mutations.

Influence of morning or evening administration on absorption of theophylline

BACKGROUND

Bronchoconstriction during the night causing nocturnal and early morning wheezing is recognized as a major problem for asthmatics. Oral sustained-release theophyllines (SRTs) were developed to reduce the symptoms. A circadian variation in theophylline kinetics has been demonstrated with many SRTs. The purpose of this study was to evaluate the differences in serum theophylline concentration (STC) caused by morning or evening dosing of Euphyllin Retard, a brand of SRT, for a period of 36 hours following oral administration.

METHODS

A total of nine non-smoking healthy male volunteers were involved in the study, with a two-period crossover comparison. They were randomly divided into two groups. The first group took a single oral dose of 350 mg Euphyllin Retard at 8:00 A.M. and the second group took it at 8:00 P.M. Blood samples were collected during the 36 hours following administration. Two weeks later, the first group took the drug at night and the second group took it in the morning. The difference in the absorption of theophylline with daytime administration versus night-time administration was assessed using pharmacokinetic parameters derived from the plasma drug concentration vs time curve.

RESULTS

The means of unextrapolated area under the concentration vs time curve (AUC) from time 0 to 24 hours (AUCUN) and of the extrapolated AUC from time 0 to infinity (AUCEX) in the night phase were higher than those in the day phase (62.403 micrograms/ml/hr vs 53.081 micrograms/ml/hr, p = 0.9186; 107.21 micrograms/ml/hr vs 98.879 micrograms/ml/hr, p = 0.8807, respectively). The mean of maximum concentration (Cmax) was higher in the night phase than that in the day phase (4.166 micrograms/dl vs 3.451 micrograms/dl, p = 0.9234). Daytime administration showed a delayed time to maximum concentration (Tmax) when compared to that of night-time administration (6.5 hr vs 5.75 hr, p = 0.6244). The terminal elimination rate constant (Kel) was lower in the day phase than in the night phase (0.053 l/hr vs 0.06 l/hr, p = 0.7601). The day phase and night phase data are combined data from the two night and two day groups. The statistical analysis of the results show that the time of administration does not influence the STC.

CONCLUSIONS

No diurnal variation in theophylline kinetics was found with Euphyllin Retard. This study was performed in a limited number of normal healthy subjects, and the same result is yet to be proved in asthmatic patients and a larger population of normal subjects.

Effects of dexamethasone on antigen expressions and proliferation of amoeboid microglial cells in fetal rat brain

The present study examined the effect of maternal administration of dexamethasone (DEX) on amoeboid microglial cells (AMC) in fetal rats extending from 16 to 20 days postconception (E16 to E20). After an intraperitoneal injection of DEX into pregnant rats at E10, the external morphology and distribution of immunolabelled AMC as detected with OX-42 and ED1 monoclonal antibodies remained unaltered when compared with those of the controls. The major effect of dexamethasone was on microglial cell population. Thus, with OX-42 and ED1, the numbers of immunolabelled AMC in the intermediate zone lateral to the striatum (IZS) of DEX-treated fetuses which remained relatively unchanged at E16 were significantly reduced at E18. However, OX-42 labelled cells showed an unexpected increase in number at E20 following DEX treatment. Microglial response to DEX was also analyzed in sections stained with the isolectin, GSA I-B4, which specifically binds alpha-D-galactosyl glycoproteins on microglia. The number of GSA I-B4 labelled AMC was significantly increased at E16, declined at E18 and remained constant thereafter in DEX-treated rats when compared with that of the controls. A major finding after DEX treatment was the wider occurrence of AMC double labelled with anti-BrdU antibody and GSA I-B4 or OX-42 at E16 compared with those in the controls suggesting that the initial increase of GSA I-B4 labelled AMC may be attributed to their proliferation. The drastic reduction of OX-42 and ED1 positive microglial cells notably at E18 may be due to the downregulation of surface antigens as a result of possible suppressive action of dexamethasone. On the basis of present findings, it is concluded that the antigenic expressions of fetal AMC may be modulated by DEX administrated maternally. Such however appeared to be extremely selective as reflected by the varied expression for certain immune molecules at different stages of brain development. This information would be useful in potential use of glucocorticoids in prenatal therapy of brain pathology via maternal circulation.

Remodeling of membrane-bound glycoproteins containing alpha-D-galactose in the cerebral endothelial cells of rats during blood-brain barrier maturation and alteration

In the course of the development of cerebral endothelia, the lectin labelling of alpha-D-galactosyl residues on the luminal front of the endothelial cells was gradually increased but that on the abluminal surface was concomitantly attenuated. In the latter, the isolectin (GSA I-B4) decoration was totally diminished with the maturation of the brain. Associated with this change, the end feet of astrocytes resting on the endothelia became lectin positive. Numerous cytoplasmic vacuoles, Golgi apparatus, vesicles and tubule-like structures were strongly labelled in the cerebral endothelia in the early stages of development but only sparse vacuoles and vesicles remained lectin-stained in the mature cerebral endothelia. Labelled pericytes closely associated with the wall of blood vessels, displayed a lectin binding pattern similar to that of the developing cerebral endothelia. Following the blood-brain barrier damage induced by a cold lesion, the altered cerebral endothelia that were surrounded by densely-stained macrophages/microglia or pericytes remained unstained with the isolectin. Present results suggest that during blood-brain barrier maturation, the brain endothelia develop a functional polarity whereby their membrane glycoprotein is down regulated. The membrane glycoprotein, however, underwent remodeling when the blood-brain barrier was disrupted.

Neuronal connections between the auricular skin and the sympathetic pre- and postganglionic neurons of the dog as studied by using pseudorabies virus

Pseudorabies virus (PrV) as a neuronal tracer was microinjected into the concave surface of the puppy's left pinna to establish the morphological basis of somato-visceral linkage. The virus infected neurons were detected by FITC conjugated with polyclonal swine anti-PrV serum. Labelled neurons were localized in: (1) the trigeminal, geniculate and superior vagal ganglia; (2) the subnucleus caudalis of the spinal trigeminal nucleus; (3) the intermediolateral column (IML) of the thoracolumbar segments and (4) the sympathetic chain ganglia. Present results suggest that when injected into the peripheral nerves, PrV was retrogradely transported to the nerve cell bodies located in the respective sensory ganglia. From the first order sensory neurons, the virus would self-replicate and was transported trans-synaptically via the brainstem nuclei and IML to reach the neurons in the sympathetic ganglia.

Synaptic relationships between corticocuneate terminals and glycine-immunoreactive neurons in the rat cuneate nucleus

The present study describes the ultrastructural synaptic relationships between corticocuneate terminals (CCTs) and glycine-immunoreactive (glycine-IR) neurons in the cuneate nucleus of rats using anterograde tract-tracing of wheatgerm agglutinin conjugated with horseradish peroxidase (WGA-HRP) and anti-glycine immunoperoxidase labeling methods. The HRP-labeled CCTs made axodendritic synapses preferentially in the ventral part of the cuneate nucleus near the obex. In a total of 182 CCTs surveyed, 14 of them made direct synaptic contacts with immunoperoxidase-labeled glycine-IR dendrites. The present results suggest that cortical modulation on the sensory transmission of cuneate nucleus may be mediated through glycine-IR neurons.

Morphometric study of glycine-immunoreactive neurons and terminals in the rat cuneate nucleus

The distribution of glycine-immunoreactive (glycine-IR) neurons and their associated axon terminals in the rat cuneate nucleus was studied using antiglycine postembedding immunoperoxidase labelling and immunogold staining, respectively. The immunoperoxidase-labelled glycine-IR neurons were widely distributed in the entire rostrocaudal extent of the nucleus. They made up 30.8% (9671/31368) of the neurons surveyed. Quantitative evaluation showed that the percentage of glycine-IR neurons in the caudal level was significantly higher than that in the middle and rostral levels. The glycine-IR neurons were small cells (mean area = 198+/-1.9 microm2, n = 2862) with ovoid or spindle-shaped somata. Statistical analysis showed that the size of the glycine-IR neurons in the rostral level was significantly smaller than that in the middle and caudal levels. Immunogold labelled glycine-IR terminals which contained predominantly pleomorphic synaptic vesicles were mostly small (mean area = 1.24+/-0.03 microm2, n = 286) and they constituted 24.7% (286/1158) of the total terminals surveyed. They formed axodendritic, axosomatic and axoaxonic synapses with unlabelled elements. It is suggested from this study that glycine is one of the major neurotransmitters involved in the depression of synaptic transmission in the cuneate nucleus.

Multiple inputs of GABA-immunoreactive neurons in the cuneate nucleus of the rat

Using anterograde transport of WGA-HRP and the experimental degeneration method for identification of corticocuneate (CCT) and primary afferent (PAT) terminals in conjunction with gamma-amino butyric acid (GABA) and glutamate immunocytochemistry, this study has demonstrated that the GABA-immunoreactive (GABA-IR) neurons in the rat cuneate nucleus were post-synaptic to PATs (some of them being glutamate-IR), GABA-IR and GABA-negative terminals. The HRP-labelled CCTs did not make any synaptic contacts with GABA-IR neurons but with some GABA-negative dendrites. PATs labelled by HRP or showing degenerating features made direct synaptic contacts with the dendrites of GABA-IR neurons. Beside the above GABA-IR boutons also showed axosomatic and axodendritic synapses with the GABA-IR neurons. In 'triple labeling' method for GABA, PAT and glutamate, it was found that the PATs which were usually glutamate-positive were presynaptic to the dendrites of GABA-IR neurons. Furthermore, some glutamate-IR terminals which were of non-PAT's origin also synapsed with the dendrites and somata of GABA-IR neurons. It is concluded from this study that the major inputs of GABA-IR neurons were from glutamate immunopositive PATs and glutamate terminals of non-PATs origin; other GABA-IR terminals either intrinsic or extrinsic also contributed to the afferent sources of GABA-IR neurons. The CCTs contributed very little, if any, to this input. It is suggested that the PATs and glutamate-IR terminals on GABA-IR neurons may be involved in lateral inhibition for increase of spatial precision. The synaptic contacts between GABA-IR boutons and dendrites or somata of GABA-IR neurons may provide a possible means for disinhibition.

Response of amoeboid and ramified microglial cells to lipopolysaccharide injections in postnatal rats--a lectin and ultrastructural study

The present study describes the response of amoeboid and ramified microglial cells in the corpus callosum to intraperitoneal lipopolysaccharide injections in postnatal rats as examined by lectin histochemical staining and electron microscopy. In 1 day old rats receiving endotoxin injections and sacrificed at various time intervals, the lectin labelling of amoeboid/ramified microglia was greatly enhanced. The increased labelling persisted in some ramified microglia in rats killed at 14 and 21 days of age; otherwise in normal or control animals of the corresponding stages, the same cells were very weakly stained. In rats killed at 2 days of age after intraperitoneal lipopolysaccharide injection, the number of microglia appeared to increase, but this was reduced at 7 days of age. The lectin-labelled amoeboid/ramified microglia were frequently seen adherent to the outer walls of the callosal blood vessels where infiltrated lymphocytes were also observed. Ultrastructurally, some lectin-labelled microglial cells underwent degeneration and were engulfed by other lectin-positive cells. After endotoxin injections, microglial cells, notably the amoeboid form, showed extensive ruffling at their cell membrane, massive accumulation of lysosomes and increased staining of lectin at their Golgi apparatus. A similar lectin labelling pattern was also observed in ramified microglia of lipopolysaccharide-injected rats. It is concluded that both amoeboid and ramified microglial cells in postnatal rats responded to endotoxin injections as reflected by their enhanced lectin labelling at the surface membrane, lysosomes and Golgi apparatus. It is suggested that such changes may be involved in synthesis and/or modification of galactosyl glycoconjugates probably for the increased production of membranous glycoproteins or lysosomal enzymes.

Immunohistochemical study of amoeboid microglial cells in fetal rat brain

The present study examined the expression of different antigens in amoeboid microglial cells (AMC) in fetal rat brain extending from 12 to 20 d postconception (E12-E20) using a panel of monoclonal antibodies which recognised the major histocompatibility complex (MHC) class I (OX-18) and class II (OX-6) antigens, leucocyte common antigen (OX-1), CD4 receptor (OX-35), complement type 3 receptor (OX-42) or macrophage antigens of unknown function (ED1 and ED2). Of the above-mentioned antigens, ED1 and ED2-labelled AMC were observed in the neuroepithelia as early as embryonic day 12 (E12); other antigens were not detected at this stage. At E14, except for MHC class I antigen, all other antigens were expressed by AMC distributed predominantly in the developing white matter. At E16, AMC in the intermediate zone lateral to the striatum were endowed with all the above-mentioned antigens including MHC class I. At E18, the immunoreactivities of AMC stained with OX-6, OX-18, OX-35 and OX-42 antigens were noticeably reduced when compared with those cells at E16. At E20, amoeboid microglial cells exhibited full complement of antigen expression similar to those cells at E16; some of the labelled cells emitted a variable number of cytoplasmic processes. It is suggested that the successive and differential expression of various macrophage related antigens on AMC in fetal brain is related to the specific requirement of local environment in different stages of development.

The composition and central projections of the internal auricular nerves of the dog

The cranial components and central terminations of the sensory nerves supplying the concave surface of the puppy's pinna, namely, the rostral, middle and caudal internal auricular nerves (RIAN, MIAN and CIAN) were investigated using horseradish peroxidase retrograde and transganglionic labelling techniques. All the 3 internal auricular nerves received contributions from the vagus. The RIAN received additional fibres from the trigeminal nerve while the MIAN and CIAN contained fibres derived from the facial nerves. In the brainstem, collaterals from the descending fibres of the afferents were given off at all levels to the medially located spinal trigeminal nucleus (SpV) which extended rostocaudally from the principal nucleus of the trigeminal nerve, subnuclei oralis, interpolaris and caudalis of the SpV to C1 or C2 cervical segment. The greatest density of central projections was observed in the subnucleus caudalis and C1. In the latter, the terminal field in the dorsal horn was roughly wedge-shaped, tapering off medially from lamina I towards lamina V. A somatotopic organisation was observed in the spinal trigeminal tract (SpVtr) and spinal trigeminal nucleus (SpV) in which the projection fibres and terminal fields of the RIAN were located lateral to those of the MIAN and CIAN. Some nontrigeminal nuclei, e.g. paratrigeminal and cuneate nuclei, nucleus X and the nucleus of the solitary tract were also labelled following HRP application to the internal auricular nerves. The localisation of the central projections of the internal auricular nerves as well as the 2nd order neurons in some specific nuclei to which the afferent fibres project is consistent with the concept of a brainstem somatovisceral link.

Ultrastructural localization of acetylcholinesterase and choline acetyltransferase in oligodendrocytes, glioblasts and vascular endothelial cells in the external cuneate nucleus of the gerbil

This study reports the reactivities of acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) in some of the nonneuronal elements in the external cuneate nucleus (ECN) of gerbils. AChE reaction products were localized in some oligodendrocytes in their cisternae of rough endoplasmic reticulum, nuclear envelope and Golgi saccules. The basal lamina lining the capillary endothelia also displayed AChE reactivity. In ChAT immunocytochemistry, the reaction products were found to be associated with the vascular basal lamina as well as the endothelial plasma membrane facing the lumen. The most remarkable finding was the localization of ChAT immunoreactivity in some oligodendrocytes and occasional glioblasts (small glial precursor cells containing a thin rim of cytoplasm surrounding an irregular nucleus with homogeneous chromatin materials). The ChAT-positive oligodendrocytes consisted of two types, medium-dense and dark cells, either associated with blood vessels or ChAT-stained neuronal elements. It is suggested from these new findings that at least some of the oligodendrocytes and glioblasts in the ECN of gerbils may be involved in the synthesis, storage, release and degradation of acetylcholine.

Unpredictability of triphenyltetrazolium chloride in staining irreversible ischaemia-reperfusion injury in the skeletal muscle of rats

OBJECTIVE

To find out whether pale staining with triphenyltetrazolium chloride (TTC) in skeletal muscle of rat hindlimbs which had been subjected to ischaemia-reperfusion definitely indicated irreversible tissue damage.

DESIGN

Laboratory study.

SETTING

University hospital, Taiwan.

MATERIAL

77 Female Wistar rats.

INTERVENTIONS

Ischaemia of one hindlimb was caused by wrapping of a tourniquet above knee joint for 1.5 (n = 14). 2 (n = 15), 2.5 (n = 17), 3 (n = 17) or 4 (n = 14) hours. Each ischaemic group was divided into three subgroups to receive nil, 1 or 1.5 hours reperfusion, respectively. Gastrocnemius and soleus muscles were excised bilaterally.

MAIN OUTCOME MEASURES

TTC reduction in the ischaemic limbs presented as a percentage of the opposite control limb measured by a spectrophotometric assay. Density of red formazan deposition in the ischaemic limbs assessed by microscopic examination of the TTC histochemical stain in the 3 hour ischaemic group.

RESULTS

In the 2, 2.5, and 3 hour ischaemic groups the TTC reduction in the ischaemic limbs after 1.5 hours reperfusion increased significantly as compared with that with one hour reperfusion (p < 0.01 in each case). The density of red formazan deposition in the muscle after 3 hours ischaemia and 1.5 hours reperfusion was significantly higher than that of only 1 hour of reperfusion.

CONCLUSION

Lack of TTC staining does not necessarily represent irreversible ischaemia-reperfusion injury of the skeletal muscle in rats.