A filtering reconfigurable intelligent surface for interference-free wireless communications

The powerful capability of reconfigurable intelligent surfaces (RISs) in tailoring electromagnetic waves and fields has put them under the spotlight in wireless communications. However, the current designs are criticized due to their poor frequency selectivity, which hinders their applications in real-world scenarios where the spectrum is becoming increasingly congested. Here we propose a filtering RIS to feature sharp frequency-selecting and 2-bit phase-shifting properties. It permits the signals in a narrow bandwidth to transmit but rejects the out-of-band ones; meanwhile, the phase of the transmitted signals can be digitally controlled, enabling flexible manipulations of signal propagations. A prototype is designed, fabricated, and measured, and its high quality factor and phase-shifting characteristics are validated by scattering parameters and beam-steering phenomena. Further, we conduct a wireless communication experiment to illustrate the intriguing functions of the RIS. The filtering behavior enables the RIS to perform wireless signal manipulations with anti-interference ability, thus showing big potential to advance the development of next-generation wireless communications.

[Clinical outcome of posterior lumbar interbody fusion combined with Ponte osteotomy for reconstruction of coronal sagittal plane balance in degenerative scoliosis]

Objective: To evaluate the clinical efficacy of posterior lumbar interbody fusion combined with Ponte osteotomy in the treatment of patients with degenerative scoliosis. Methods: The medical records and imaging data of degenerative scoliosis in department of orthopedics, Peking Union Medical College Hospital from 2013 to 2022 were retrospectively collected, and the shortest follow-up time was 1 year. A total of 38 patients were included, including 13 males and 25 females, aged 50-87(65.6±10.9) years old.The follow-up was12-119(43±20) months. Standing position full spine anteroposterior lateral X-ray examinations were performed on all patients preoperatively, postoperatively, and at latest follow-up. The length of hospital stay, complications, operation time, blood loss, instrumented segment, fusion segmen were recorded. The clinical scores and coronasagittal imaging indicators at three time points were compared. Results: The operation time was (274.5±70.5)min, and intraoperative blood loss was (619.2±93.5)ml. The coronal vertical axis was improved from (2.9±1.8)cm preoperatively to (1.2±1.0)cm postoperatively. The preoperative coronal Cobb angle was 16.6°±9.9° and the immediate postoperative correction was 6.4°±4.0°(t=-6.83, P<0.001). The difference was statistically significant (t=-6.12, P<0.001). The coronal Cobb Angle at the last follow-up was 5.7°±3.7°, and there was no significant orthopaedic loss at the last follow-up (t=-6.12, P<0.001).The sagittal vertical axis decreased from (5.6±3.9)cm preoperatively to (3.2±2.5) cm immediately after operation (t=-6.83,P<0.001), and was well maintained at the last follow-up[(2.7±1.8) cm,t=-7.77,P<0.001]. Lumbar lordosis increased from 21.8°±10.2° preoperatively to 35.8°±8.3° postoperatively(t=12.01, P<0.001)and 40.1°±8.6° at last follow-up(t=-10.21, P<0.001). Oswestry disability score (ODI score), visual analogue score (VAS) low back pain score and VAS leg pain score were also lower after surgery than before surgery (all P<0.05). Conclusion: Posterior lumbar interbody fusion combined with Ponte osteotomy can significantly improve the coronal and sagittal plane deformity and postoperative functional score in adult patients with degenerative scoliosis.

Radar Micro-Doppler Signature Generation Based on Time-Domain Digital Coding Metasurface

Micro-Doppler effect is a vital feature of a target that reflects its oscillatory motions apart from bulk motion and provides an important evidence for target recognition with radars. However, establishing the micro-Doppler database poses a great challenge, since plenty of experiments are required to get the micro-Doppler signatures of different targets for the purpose of analyses and interpretations with radars, which are dramatically limited by high cost and time-consuming. Aiming to overcome these limits, a low-cost and powerful simulation platform of the micro-Doppler effects is proposed based on time-domain digital coding metasurface (TDCM). Owing to the outstanding capabilities of TDCM in generating and manipulating nonlinear harmonics during wave-matter interactions, it enables to supply rich and high-precision electromagnetic signals with multiple micro-Doppler frequencies to describe the micro-motions of different objects, which are especially favored for the training of artificial intelligence algorithms in automatic target recognition and benefit a host of applications like imaging and biosensing.

Manipulations of multi-frequency waves and signals via multi-partition asynchronous space-time-coding digital metasurface

Manipulations of multiple carrier frequencies are especially important in a variety of fields like radar detection and wireless communications. In conventional radio-frequency architecture, the multi-frequency control is implemented by microwave circuits, which are hard to integrate with antenna apertures, thus bringing the problems of expensive system and high power consumption. Previous studies demonstrate the possibility to jointly control the multiple harmonics using space-time-coding digital metasurface, but suffer from the drawback of inherent harmonic entanglement. To overcome the difficulties, we propose a multi-partition asynchronous space-time-coding digital metasurface (ASTCM) to generate and manipulate multiple frequencies with more flexibility. We further establish an ASTCM-based transmitter to realize wireless communications with frequency-division multiplexing, where the metasurface is responsible for carrier-wave generations and signal modulations. The direct multi-frequency controls with ASTCM provides a new avenue to simplify the traditional wireless systems with reduced costs and low power consumption.

[The role of Keap1/Nrf2/HO-1 signal pathway in liver injury induced by rare earth neodymium oxide in mice]

Objective: To investigate the role of Keap1/Nrf2/HO-1 signaling pathway in liver injury induced by neodymium oxide (Nd(2)O(3)) in mice. Methods: In March 2021, forty-eight SPF grade healthy male C57BL/6J mice were randomly divided into control group (0.9% NaCl), low dose group (62.5 mg/ml Nd(2)O(3)), medium dose group (125.0 mg/ml Nd(2)O(3)), and high dose group (250.0 mg/ml Nd(2)O(3)), each group consisted of 12 animals. The infected groups were treated with Nd(2)O(3) suspension by non-exposed tracheal drip and were killed 35 days after dust exposure. The liver weight of each group was weighed and the organ coefficient was calculated. The content of Nd(3+) in liver tissue was detected by inductively coupled plasma mass spectrometry (ICP-MS). HE staining and immunofluorescence was used to observe the changes of inflammation and nuclear entry. The mRNA expression levels of Keap1, Nrf2 and HO-1 in mice liver tissue were detected by qRT-PCR. Western blotting was used to detect the protein expression levels of Keap1 and HO-1. The contents of catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) were detected by colorimetric method. The contents of interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were determined by ELISA. The data was expressed in Mean±SD. Two-independent sample t-test was used for inter-group comparison, and one-way analysis of variance was used for multi-group comparison. Results: Compared with the control group, the liver organ coefficient of mice in medium and high dose groups were increased, and the Nd(3+) accumulation in liver of mice in all dose groups were significantly increased (P<0.05). Pathology showed that the structure of liver lobules in the high dose group was slightly disordered, the liver cells showed balloon-like lesions, the arrangement of liver cell cords was disordered, and the inflammatory exudation was obvious. Compared with the control group, the levels of IL-1β and IL-6 in liver tissue of mice in all dose groups were increased, and the levels of TNF-α in liver tissue of mice in high dose group were increased (P<0.05). Compared with the control group, the mRNA and protein expression levels of Keap1 in high dose group were significantly decreased, while the mRNA expression level of Nrf2, the mRNA and protein expression levels of HO-1 were significantly increased (P<0.05), and Nrf2 was successfully activated into the nucleus. Compared with the control group, the activities of CAT, GSH-Px and T-SOD in high dose group were significantly decreased (P<0.05) . Conclusion: A large amount of Nd(2)O(3) accumulates in the liver of male mice, which may lead to oxidative stress and inflammatory response through activation of Keap1/Nrf2/HO-1 signal pathway. It is suggested that Keap1/Nrf2/HO-1 signal pathway may be one of the mechanisms of Nd(2)O(3) expose-induced liver injury in mice.

[Comparison of the therapeutic effects of optic nerve sheath fenestration and medication on papilledema due to cerebral venous thrombosis]

Objective: To compare the therapeutic effects of optic nerve sheath fenestration (ONSF) and medication on papilledema induced by cerebral venous thrombosis (CVT). Methods: Patients with papilledema induced by CVT in Beijing Tiantan Hospital and Xuanwu Hospital from January 2017 to July 2022 were retrospectively enrolled and were divided into two groups according to the treatment strategies they underwent, with 76 cases (107 eyes) in ONSF group and 35 cases (69 eyes) in medication group. The degree of papilledema was evaluated by the modified Frisén's grading (grade 0-1 was defined as mild, grade 2-3 was moderate, and grade 4-5 was severe edema). The mean defect (MD) of visual field, the degree of papilledema, and the mean retinal nerve fiber layer (RNFL) thickness in different subgroups were compared between baseline versus 1 month after ONSF or medication. Results: There were 76 cases in ONSF group (26 males and 50 females), and aged (35.3±11.4) years. Meanwhile, there were 35 cases in medication group (22 males and 13 females), and aged (35.2±11.0) years. Compared with baseline, MD were improved in both moderate [(-8.4±6.6) vs (-11.8±8.6) db, P=0.021] and severe [(-8.1±5.3) vs (-11.4±6.9) db, P<0.001] papilledema subgroups after ONSF, while there was an improvement in mild papilledema subgroup [(-1.5±5.3) vs (-3.4±5.1) db, P<0.001] after medication. The papilledema (Frisén's scores) in both ONSF group (P<0.001) and medication group (P=0.010) was improved. Compared with baseline, the mean RNFL decreased in mild [(78.5±13.5) vs (91.0±17.4) μm, P=0.002], moderate [(126.6±67.6) vs (154.8±77.9) μm, P=0.011] and severe [(179.0±70.9) vs (230.6±89.7) μm, P=0.001] papilledema subgroups after ONSF, while the mean RNFL decreased [(142.0±29.3) vs (158.8±22.7) μm, P=0.020] in moderate papilledema subgroup after medication. Conclusions: ONSF might attenuate CVT-mediated papilledema, and improve the visual function in patients with moderate and severe papilledema. Likewise, patients with mild papilledema could also get benefit from medication.

Asynchronous Space-Time-Coding Digital Metasurface

Recent progress in space-time-coding digital metasurface (STCM) manifests itself a powerful tool to engineer the properties of electromagnetic (EM) waves in both space and time domains, and greatly expands its capabilities from the physical manipulation to information processing. However, the current studies on STCM are focused under the synchrony frame, namely, all meta-atoms follow the same variation frequency. Here, an asynchronous STCM is proposed, where the meta-atoms are modulated by different time-coding periods. In the proposed asynchronous STCM, the phase discontinuities on traditional metasurface are replaced with the frequency discontinuities. It is shown that dynamic wavefronts can be automatically realized for both fundamental and high-order harmonics by elaborately arranging the spatial distribution of meta-atoms with various time-coding periods. The physics insight is due to the accumulated rapidly changing phase difference with time, which offers an additional degree of freedom during the wave-matter interactions. As a proof-of-principle example, an asynchronous STCM for automatic spatial scanning and dynamic scattering control is investigated. From the theory, numerical simulations, and experiments, it can be found that the proposed STCM exhibits significant potentials for applications in radars and wireless communications.

[Complications of chronic cough]

Chronic cough is a common complaint, which may cause various complications involving many organ systems, including respiratory system, circulatory system, digestive system, urinary system, reproductive system, skeletal movement system, nervous system, etc. Cough and its complications are associated with an adverse impact on the work and quality of life in the huge population with chronic cough, and lead to an increased healthcare resource utilization. In this paper, we review the common complications of chronic cough by organ system classification.

[Updated key points of Chinese Consensus for the Diagnosis and Treatment of Acromegaly (2021 edition)]

Led by the China Pituitary Adenoma Specialist Council, the Chinese Consensus for the Diagnosis and Treatment of Acromegaly (2021 Edition) is developed combined with the research progress of pituitary growth hormone (GH)-secreting adenoma both at home and abroad, evidence-based evidence of the diagnosis and treatment of acromegaly, and China's national conditions. Based on the guideline for acromegaly (2013 Edition), the new version of consensus emphasizes the importance of multidisciplinary team (MDT) and individual therapy. The criteria for control of acromegaly is discussed. Pathological criteria for the diagnosis of pituitary GH-secreting adenoma is updated. New developments in surgery, drug and radiotherapy are introduced. Meanwhile, the diagnosis and treatment of acromegaly patients concurrent with other particular scenarios, including pregnancy and refractory pituitary GH-secreting adenoma is suggested. This article aims to describe the updated key points of the new version of the consensus, and thus facilitate the clinical implementation of standardized diagnosis and treatment for acromegaly patients.

[Diagnostic value of ultrasonic elastic strain ratio and elasticity score for thyroid micronodules of TI-RADS 4]

Objective: To investigate diagnostic value of ultrasonic elastic strain ratio and elasticity score for thyroid micronodules of TI-RADS 4. Method: In total, 211 consecutive patients with 225 thyroid micronodules were enroled in the study, all the nodules were evaluated by TI-RADS criteria before and all of them were examined by elastic imaging. We set the histology as the reference standard. The elastic strain ratio and elasticity score values, as well as their diagnostic threshold and efficiency, were compared and analyzed by the receiver operating characteristic(ROC) curve. Result: Statistically significant differences(P<0.05) in both elastic strain ratio and elasticity score values were detected among the thyroid microcarcinoma and benign groups. The area under the ROC curve of elastic strain ratio was significantly greater than that of elasticity score(0.935 and 0.825, respectively; P<0.05). Using elastic strain ratio ≥3.45 and elasticity score ≥3.00 as diagnostic threshold values, the diagnostic sensitivity, specificity, and accuracy of elastic strain ratio for differentiating benign and malignant nodules were 86.51%, 90.32%, and 87.56%, respectively, whereas those of elasticity score were 80.98%, 79.03% and 80.44%, respectively. Conclusion: Ultrasonic elastic strain ratio and elasticity score have very high diagnostic value for the thyroid micronodules of TI-RADS 4, and strain ratio has more advantages.

Trends in atmospheric particles and their light extinction performance between 1980 and 2015 in Beijing, China

This study explored the interdecadal variations and their horizontal and vertical light extinction performances of atmospheric particulate matter with aerodynamic diameters ≤2.5 μm (PM_2.5), particulate matter with aerodynamic diameters ≤ 10 μm (PM₁₀), and total suspended particulates (TSPs) in Beijing from 1980 to 2015, using data available from historical publications. Prominent declines of PM_2.5, PM₁₀, and TSPs were detected with long-term linear trends of -6.7, -4.3, and -1.9 μg m^-3 yr^-1, respectively. Generally, on the annual scale during the studied period, it was found that PM_2.5 displayed negative correlation (R² = 0.38, p < 0.01) with visibility and positive correlation (R² = 0.41, p < 0.01) with aerosol optical depth (AOD). Comparably, PM₁₀ exhibited robust negative correlation (R² = 0.61, p < 0.01) with visibility and positive correlation (R² = 0.82, p < 0.01) with AOD. The complicated interdecadal variations and light extinction performances of PM_2.5 were found, suggesting the changes on particle composition and vertical distribution of PM_2.5 in the atmosphere.

Effect of cocaine on ion channels and glutamatergic EPSCs in noradrenergic locus coeruleus neurons

The locus coeruleus (LC) is an important brainstem area involved in cocaine addiction. However, evidence to elucidate how cocaine modulates the activity of LC neurons remains incomplete. Here, we performed whole recordings in brain slices to evaluate the effects of cocaine on the sodium (Na(+)), potassium (K(+)), calcium (Ca(2+)) channels, and glutamatergic synaptic transmission in the locus coeruleus neurons. Local application of cocaine significantly and reversibly reduced the spontaneous firing rate but did not affect action potential amplitude, rising time, decay time, or half width of noradrenergic locus coeruleus neurons. Moreover, cocaine attenuated the sodium current but did not affect potassium and calcium currents. The N-methyl-D-aspartate receptor mediated excitatory postsynaptic currents were reduced by neuropeptide galanin but not cocaine. All those data demonstrate that cocaine has inhibitory effect on the spontaneous activities and sodium current in locus coeruleus neurons. Therefore, neuromodulation of sodium channel in locus coeruleus neurons may play an important role in drug addiction.

The pyrolytic degradation of wood-derived lignin from pulping process

Lignin is a key component in the biomass with a complex polymeric structure of the phenyl-C(3) alkyl units. The kraft lignin from the wood pulping process is tested in TG-FTIR and Py-GC-MS. The samples are pyrolyzed in TGA coupled with FTIR from 30 to 900 degrees C at the heating rate of 20 and 40K/min. The evolution of phenolic compounds in the initial pyrolysis stage of lignin is determined by FTIR, while the second stage is mainly attributed to the production of the low molecular weight species. A bench-scale fast pyrolysis unit is employed to investigate the effect of temperature on the product yield and composition. It is found that the guaiacol-type and syringol-type compounds as the primary products of lignin pyrolysis are predominant in bio-oil, acting as the significant precursors for the formation of the derivatives such as the phenol-, cresol- and catechol-types. A series of free-radical chain-reactions, concerning the cracking of different side-chain structures and the methoxy groups on aromatic ring, are proposed to demonstrate the formation pathways for the typical compounds in bio-oil by closely relating lignin structure to the pyrolytic mechanisms. The methoxy group (-OCH(3)) is suggested to work as an important source for the formation of the small volatile species (CO, CO(2) and CH(4)) through the relevant free radical coupling reactions.

Effects of recombinant human growth hormone on acute lung injury in endotoxemic rats

OBJECTIVE

To investigate the effects of recombinant human growth hormone (rhGH) on rat acute lung injury (ALI).

METHODS

ALI was mimicked by intraperitoneal (i. p.) injection of E. coli. Female Sprague-Dawley rats were randomized into three groups: control group, injected with physiologic saline (i. p.); ALI group, received a bolus injection of E. coli (1 x 10(10) cfu/l, 15 ml/kg, i. p.) followed by intramuscular physiologic saline injection; and ALI + GH group, received a bolus administration of E. coli, and then treated with intramuscular rhGH injection (2.25 U/kg/d). ALI group and ALI + GH group were subdivided into day 1 and day 3 subgroups, respectively. Left lungs were lavaged and bronchial alveolar lavage fluid (BALF) was harvested. Lung injury score, lung wet-to-dry weight (W/D) ratio, percentage of neutrophils (PMNs) in BALF, lung permeability index (LPI), intercellular adhesion molecule-1(ICAM-1) expression and activation of nuclear factor-kappa B (NF-kappaB) in the lungs were determined.

RESULTS

(1) On day 1 and day 3, the lung injury score, lung W/D ratio, LPI and protein content in BALF were significantly higher in the ALI group than in the control and ALI + GH groups. rhGH attenuated lung injuries significantly. (2) Compared with the control group, the percentage of PMNs in BALF was elevated significantly in the ALI and ALI + GH groups, especially in ALI group. (3) Nuclear positive rate of NF-kappaB and ICAM-1 expression at the levels of protein and mRNA in the lung in the ALI group on day 1 and day 3 were higher than in the control group. rhGH diminished activation of NF-kappaB and expression of ICAM-1 in the lung markedly.

CONCLUSIONS

Treatment with rhGH can significantly attenuate lung injury in the endotoxemic rats, which may be attributed to the reduction of the expression of ICAM-1, the influence on the adhesion and activation of PMNs, the inhibition of the activation of NF-kappaB and the regulation of the transcription of certain proinflammatory cytokines.

Beneficial effect of recombinant human growth hormone on the intestinal mucosa barrier of septic rats

The objective of the present study was to investigate the effects of recombinant human growth hormone (rhGH) on the intestinal mucosa barrier of septic rats and explore its possible mechanism. Female Sprague-Dawley rats were randomized into three groups: control, Escherichia coli-induced sepsis (S) and treatment (T) groups. Groups S and T were subdivided into subgroups 1d and 3d, respectively. Expression of liver insulin-like growth factor-1 (IGF-1) mRNA, Bcl-2 and Bax protein levels and the intestinal Bax/Bcl-2 ratio, and plasma GH and IGF-1 levels were determined. Histological examination of the intestine was performed and bacterial translocation was determined. rhGH significantly attenuated intestinal mucosal injuries and bacterial translocation in septic rats, markedly decreased Bax protein levels, inhibited the decrease of Bcl-2 protein expression and maintained the Bax/Bcl-2 ratio in the intestine. rhGH given after sepsis significantly improved levels of plasma GH (T1d: 1.28 +/- 0.24; T3d: 2.14 +/- 0.48 microg/L vs S1d: 0.74 +/- 0.12; S3d: 0.60 +/- 0.18 microg/L; P < 0.05) and IGF-1 (T1d: 168.94 +/- 65.67; T3d: 201.56 +/- 64.98 microg/L vs S1d: 116.72 +/- 13.96; S3d: 107.50 +/- 23.53 microg/L; P < 0.05) and expression of liver IGF-1 mRNA (T1d: 0.98 +/- 0.20; T3d: 1.76 +/- 0.17 vs S1d: 0.38 +/- 0.09; S3d: 0.46 +/- 0.10; P < 0.05). These findings indicate that treatment with rhGH had beneficial effects on the maintenance of the integrity of the intestinal mucosa barrier in septic rats.

Inhibition of nuclear factor-κB by an antioxidant enhances paclitaxel sensitivity in ovarian carcinoma cell line

The objective of this study was to determine whether paclitaxel and a strong antioxidant, pyrrolidinedithiocarbamate (PDTC), can affect the activation of nuclear factor-kappa B (NF-kappaB) in SKOV-3 human ovarian cancer cell line and the effect of these two agents on the growth and apoptosis of the cancer cells. The cells were treated with various concentrations of paclitaxel and/or PDTC at various time intervals. Following treatments, cell growth and apoptosis were determined by 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulphonyl)-2H-tetrazolium (WST-8) (WST) assay and flow cytometry, respectively. Western blot assay was used to determine the nuclear p65 protein and cytoplasmic IkappaB-alpha protein. High doses of PDTC significantly inhibited the growth of SKOV-3 cells and caused apoptosis. Paclitaxel and lower doses of PDTC combined demonstrated additive inhibition of cell growth and increased levels of apoptosis. Treatment of paclitaxel alone showed increased nuclear p65 protein and decreased cytoplasmic IkappaB-alpha protein expression, while pretreatment of PDTC reversed this function. PDTC blocks the paclitaxel-induced activation of NF-kappaB leading to increased chemosensitivity to paclitaxel and enhanced apoptosis. Combining antioxidants and paclitaxel has significant potential to overcome the risk of paclitaxel resistance.

Cardiovascular disease risk factors in chronic renal insufficiency

BACKGROUND

Coronary heart disease (CHD) is an important cause of morbidity and mortality in end-stage renal disease (ESRD). Prevention of CHD in ESRD requires identification and treatment of coronary risk factors in chronic renal insufficiency (CRI).

METHODS

We evaluated the prevalence of "traditional coronary risk factors" in CRI in 1,795 patients enrolled in the baseline period of Modification of Diet in Renal Disease (MDRD) Study. Using a cross-sectional design, we determined the relationship of these risk factors to the level of glomerular filtration rate (GFR) and proteinuria. We also predicted the CHD risk in the MDRD Study baseline cohort using the coronary point score.

RESULTS

64.0% had blood pressure > or = 130/85 mmHg despite antihypertensive therapy. 64.2% had LDL cholesterol > or = 130 mg/dl, while 38.3% had HDL cholesterol < 35 mg/dl. After adjustment for age, gender and the presence of diabetes, GFR was inversely associated with systolic blood pressure and positively associated with HDL cholesterol, but not associated with total or LDL cholesterol. After adjustment for age. gender and the presence of diabetes, proteinuria was positively associated with systolic and diastolic blood pressure, total serum cholesterol and LDL cholesterol, and inversely associated with HDL cholesterol. Nonetheless, the predicted CHD risk, even at a very low GFR, was similar to the risk in the general population and lower than the observed rate of de novo CHD in incident dialysis patients.

CONCLUSIONS

"Traditional coronary risk factors" are highly prevalent in CRI and vary with the level of renal function. However, the coronary point score does not appear to explain the extent of increased CHD risk in ESRD. Non-traditional risk factors may also contribute to CHD in ESRD.

Directional responses of basal optic neurons are modulated by the nucleus lentiformis mesencephali in pigeons

The nucleus lentiformis mesencephali (nLM) and the nucleus of the basal optic root (nBOR) in pigeons are both involved in optokinetic nystagmus. They are reciprocally connected and thus may interact with each other. The present study injected lidocaine into nLM and then examined the effects of nLM blockade on visual responses of nBOR neurons to target motion. The results indicate that nLM could modulate nBOR activity in two ways. First, nLM enhances visual responses of 70% of nBOR cells to motion in the preferred directions, sharpening their directional tuning. Second, nLM reduces visual responses of 13% of nBOR cells to motion in the preferred directions, broadening their directional tuning. The remaining 17% of nBOR cells are not affected by drug application. Taken together with the previous results that nBOR could modulate nLM activity (Gu et al., Neuroscience, 104 (2001) 153), it suggests that both nuclei can mutually modulate each other in generating optokinetic nystagmus.

Directional modulation of visual responses of pretectal neurons by accessory optic neurons in pigeons

The nucleus lentiformis mesencephali and the nucleus of the basal optic root in birds, homologous to the nucleus of the optic tract and the terminal nuclei of the accessory optic tract in mammals, are involved in optokinetic nystagmus. The present study provides the first electrophysiological evidence that reversible blockade of the pigeon nucleus of the basal optic root by lidocaine can change visual responsiveness of pretectal neurons in a direction-dependent manner. Thirty pretectal cells examined were classified as unidirectional (80%), bidirectional (10%) and omnidirectional (10%) cells according to their directional selectivity. Among the unidirectional cells, seven cells changed firing rates in all directions of motion, 11 changed visual responses only in the preferred directions and six others did not change their responsiveness during lidocaine. Most of the bidirectional cells changed firing rates in the temporonasal direction, and two-thirds of the omnidirectional cells showed these changes in all directions. Thirteen lidocaine administration sites were marked within the nucleus of the basal optic root and 19 recording sites were marked within the nucleus lentiformis mesencephali. This histological verification indicates that the effects of lidocaine blockade in the accessory optic nucleus on the directional selectivity and visual responsiveness of pretectal cells appear to be related, to some extent, to the location of drug injections in the nucleus of the basal optic root. This study has found that visual neurons in the nucleus of the basal optic root, which predominantly prefer vertical and backward motion, could modulate the directional selectivity and visual responsiveness of neurons in the nucleus lentiformis mesencephali, which mainly prefer horizontal motion. It is conceivable that both nuclei work together in coordination and in competition during optokinetic nystagmus.

Firing patterns and morphological features of neurons in the pigeon nucleus rotundus

In birds, the thalamic nucleus rotundus relays visual information from the midbrain optic tectum to the forebrain ectostriatum. Using brain slices, the present study investigates the firing patterns and morphological features of 41 neurons in various divisions of the pigeon nucleus rotundus. The results indicate that these rotundal cells could be physiologically categorized into two types according to their firing patterns in response to depolarizing current pulses. Type I cells (76%) are characterized by a multi-phase firing pattern producing a single spike, late-spiking and fast-spiking as current intensity increases. Cells of type II (24%) are characterized by a rapid spiking-inactivation, discharging only one or two small spikes at the onset of current injections. However, intracellular staining shows no significant morphological differences between the two physiological types of cells in terms of somatic and dendritic field sizes, or an average density of dendritic varicosities, although each cell type includes both small- and large-sized dendritic fields. It is likely that the firing patterns and morphological features of rotundal neurons might not be correlated with each other or with rotundal divisions.

Electrophysiological and anatomical evidence for a direct projection from the nucleus of the basal optic root to the nucleus rotundus in pigeons

A direct projection of the nucleus of the basal optic root (nBOR) onto the nucleus rotundus (Rt) in the pigeon would link the accessory optic system to the ascending tectofugal pathway and could thus combine self- and object-motion processes. In this study, injections of retrograde tracers into the Rt revealed some cells in central nBOR to project onto the ipsilateral Rt. Contrary, injections into the diencephalic component of the ascending thalamofugal pathway resulted in massive labeling of neurons in dorsal nBOR. Single unit recordings showed that visual nBOR units could be activated by antidromic stimulation through the Rt. Successful collision tests applied to nBOR cells revealed that the connection between nBOR and Rt is direct. These data provide strong evidence for a direct and differential projection of nBOR subcomponents onto the thalamic relays of the two ascending visual pathways.

Effects of BCG on ovalbumin-induced bronchial hyperreactivity in a guinea pig asthma model

To test the effects of Bacillus Calmette-Guérin (BCG) on ovalbumin (OVA)-induced airway hyper-reactivity in guinea pigs, a total of 40 young guinea pigs was individually vaccinated subcutaneously with 0.2 mL of 2% OVA, 50 microg BCG, or a mixture of OVA and BCG (OVA+BCG). Airways were sensitized using nebulization with 1% OVA for 3 min once a week for two applications, followed by 2% OVA nebulized challenge for 3 min 1 week after the last application. Different concentrations of methacholine were used to detect airway hyperreactivities. At the third week, the guinea pigs were nebulized with either methacholine or OVA to test airway hyperreactivity. The OVA-vaccinated group presented with severe airway hyperresponsiveness after OVA and methacholine challenges; the BCG-vaccinated group showed mild airway hyperreactivity; and the OVA+BCG group showed the least amount of airway hyperreactivity. Lung histopathology in all groups, except the OVA+BCG-vaccinated group, showed severe thickening of the alveolar walls which became firmly fibrotic, and narrowing of the alveolar spaces was also noted. The guinea pigs in the OVA+BCG-vaccinated group had similar pulmonary morphology with that of naive guinea pigs, and had mild cell infiltration in the alveolar wall. The results of the skin biopsies at 6 h (2% OVA, 0.05 mL) and 36 h (20 microg PPD, 0.05 mL) after purified protein derivative (PPD) inoculation showed that infiltration of eosinophils and activation of CD4+ T-cells occurred in the OVA-vaccinated group. In the BCG-vaccinated groups, infiltration of CD4+ T-cells, CD8+ T-cells and macrophages occurred. OVA-specific IgG2 increased in the BCG-vaccinated groups after OVA-induced airway hyperreactivity occurred. The peripheral cell subpopulation showed that there was obviously increased activation of CD4+ and CD8+ T-cells in the OVA+BCG-vaccinated group. The phagocytic activity of macrophages also increased in both BCG- and OVA+BCG-vaccinated groups. The prevention of OVA-induced airway hyperreactivities using BCG vaccination in conjugation with OVA in these young guinea pigs indicated that it might be a good approach to avoid allergic reactions in humans.

Tecto-isthmo-optic transmission in pigeons is mediated by glutamate and nitric oxide

The isthmo-optic nucleus of the centrifugal system in birds receives primarily input from the ipsilateral tectum and projects to the contralateral retina. The present study using brain slices and microiontophoresis shows that synaptic transmission from the tectum to the centrifugal nucleus in pigeons is excitatory. About 75% of tecto-isthmo-optic fibers are glutamatergic, mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid but not N-methyl-D-aspartate-receptors, and 25% of others may use nitric oxide as a transmitter or modulator. On the other hand, about 60% of isthmo-optic cells receive glutamatergic afferents, 20% receive nitric oxidergic afferents, and 20% of others receive both glutamatergic and nitric oxidergic afferents from the tectum. In the last group, it is more likely that both glutamate and nitric oxide may co-release from the same tecto-isthmo-optic terminals. All the isthmo-optic cells examined in the present study also receive gamma-aminobutyric acid (GABA)ergic afferents via GABA(A) and GABA(B) receptors probably from some extratectal structures.

Serine protease isoforms of Deinagkistrodon acutus venom: cloning, sequencing and phylogenetic analysis

The major coagulating fibrinogenase of Deinagkistrdon acutus venom, designated acutobin, was purified by anion-exchange chromatography, gel filtration and reverse-phase HPLC. Approximately 80% of its protein sequence was determined by sequencing the various fragments derived from CNBr cleavage and digestion with endoprotease. Extensive screening of the venom gland cDNA species after amplification by PCR resulted in the isolation of four distinct cDNA clones encoding acutobin and three other serine proteases, designated Dav-PA, Dav-KN and Dav-X. The complete amino acid sequences of these enzymes were deduced from the cDNA sequences. The amino-acid sequence of acutobin contains a single chain of 236 residues including four potential N-glycosylation sites. The purified acutobin (40 kDa) contains approx. 30% carbohydrate by weight, which could be partly removed by N-glycanase. The phylogenetic tree of the complete amino acid sequences of 40 serine proteases from 18 species of Crotalinae shows functional clusters reflecting parallel evolution of the three major venom enzyme subtypes: coagulating enzymes, kininogenases and plasminogen activators. The possible structural elements responsible for the functional specificity of each subtype are discussed.

Identification of vacuolar serine proteinase as a major allergen of Aspergillus fumigatus by immunoblotting and N-terminal amino acid sequence analysis

Aspergillus species are common airborne fungi that have been identified as causative agents of extrinsic bronchial asthma. More than 10 allergens from A. fumigatus have been recently characterized by cDNA cloning. The objective of this study is to identify A. fumigatus allergens through immunoblot analysis using sera from asthmatic patients. IgE-binding components of A. fumigatus and IgE cross-reactivity among allergens of different prevalent airborne fungal species were analysed by immunoblot and immunoblot inhibition, respectively, using sera from asthmatic patients. The N-terminal amino acid sequences of major allergens identified were determined by Edman degradation. Among two batches (70 and 41 sera) of asthmatic sera tested, 19 (27%) and 14 (34%), respectively, have IgE immunoblot reactivity towards components of A. fumigatus. A 34-kDa protein that reacts with IgE antibodies in 15 (79%) and 11 (79%) of the 19 and 14 positive samples, respectively, may be considered a major allergen of A. fumigatus. The N-terminal amino acid sequences of the 34 kDa major allergen and the 30.5 and 30 kDa IgE-binding components of A. fumigatus showed sequence identity to that of the vacuolar serine proteinase from A. fumigatus. The results from immunoblot inhibition show IgE cross-reactivity among major allergens of A. fumigatus, P. notatum and P. oxalicum. Results obtained suggest that the 34 kDa major allergen of A. fumigatus may be a vacuolar serine proteinase. There is IgE cross-reactivity among serine proteinase allergens of A. fumigatus, P. notatum and P. oxalicum.

Visual responses of neurons in the pretectal nucleus lentiformis mesencephali to moving patterns within and beyond receptive fields in pigeons

Large-field patterns are effective stimuli for eliciting visual responses from neurons in the pretectal nucleus lentiformis mesencephali of nonmammals. The present study shows that stimulation beyond the receptive field does not contribute to the visual responses of neurons in the nucleus lentiformis mesencephali in two respects. First, changes in the direction and velocity of motion beyond the receptive field did not affect the visual responses of the pretectal cells to motion within the receptive field. Second, time differences in the onset of stimulation within and outside the receptive field did not influence the visual responses of the pretectal cells to motion in the receptive field, implying that there may be no long-range interaction between the receptive field and its surrounding field. The present study also indicates that the pretectal cells are not only sensitive to the direction and velocity of motion, but also to the size and density of dots in a random-dot pattern moving through the receptive field. Taken together with previous studies, these results suggest that the receptive field of the pretectal cells within the nucleus lentiformis mesencephali is large in size but well defined in boundaries, and that the pretectal cells respond to motion of visual stimuli within but not beyond their receptive fields.

cDNA cloning and immunologic characterization of Pen o 18, the vacuolar serine protease major allergen of Penicillium oxalicum

Penicillium species are prevalent indoor airborne fungi that have been identified as causative agents of human extrinsic bronchial asthma. In the preparation of standardized diagnostic reagents, it is imperative to define the allergens of these ubiquitous fungi. Results from our previous study on P. oxalicum suggest that the 34-kd major immunoglobulin E-reacting component of this prevalent Penicillium species is probably a vacuolar serine protease. The purpose of the present study was to define this major P. oxalicum allergen (Pen o 18) through cDNA cloning and immunologic characterization. The cDNA of Pen o 18 was isolated through a combination of reverse transcriptase-polymerase chain reaction and 5'- and 3'-rapid amplification cDNA ends reactions. The primers used in these reactions were constructed according to the internal amino acid sequences of Pen o 18 and the conserved amino acid sequences of fungal serine proteases. Our results showed that a 1897-bp cDNA with an open reading frame of 503 residues was isolated for the proenzyme of Pen o 18. The encoded protein has a 16-residue signal peptide and a 119-residue prosequence. On maturation, the protein has an N-terminal glutamate that is the 136th residue encoded by the cDNA. Apparently the precursor also undergoes C-terminal processing with the cleavage of about 47 amino acids. The cDNA for Pen c 18 (the vacuolar serine protease allergen from P. citrinum ) was also isolated for comparison. Contrary to a previous report, the C-terminal region of Pen c 18 is similar to that of Pen o 18. Recombinant proteins (rPen o 18 and rPen c 18) with the putative mature N-termini and a his-tag were obtained by expressing the corresponding cDNAs in Escherichia coli. Serum samples from 7 asthmatic patients with immunoglobulin E reactivity to the 34-kd component of P. oxalicum also react to his-tagged recombinant Pen o 18. The presence of immunoglobulin E cross-reactivity between rPen o 18 and rPen c 18 was detected by immunoblot inhibition. Two monoclonal antibodies (PCM39 and FUM20) against fungal serine proteases react with rPen o 18, rPen c 18, and the 35/34-kd components in the corresponding crude fungal extracts. These components also react with immunoglobulin E antibodies in serum samples from asthmatic patients. In conclusion, results obtained confirm that the 34-kd major allergen of P. oxalicum is a vacuolar serine protease. The cDNAs of Pen o 18 and Pen c 18 encode precursor molecules that appear to undergo both N-terminal and C-terminal processing. Constructs beginning with mature N-terminal can be expressed in E. coli to produce recombinant polypeptides that are reactive to monoclonal antibodies or immunoglobulin E antibodies in serum samples from asthmatic patients. Results obtained may provide useful information and materials for preparation of standardized diagnostic reagents in clinical mold allergy.

Modulatory effects of the nucleus of the basal optic root on rotundal neurons in pigeons

The present paper reports for the first time in birds the modulatory effects of the nucleus of the basal optic root (nBOR) on visual neurons in the nucleus rotundus in particular and those of the accessory optic system on the tectofugal pathway in general. Pharmacological blockade of the nBOR by lidocaine led to a decrease or increase in visual responsiveness of rotundal cells, suggesting excitatory or inhibitory actions of the nBOR on rotundal cells. These results were confirmed by changes in the excitability of rotundal cells following electrical stimulation of the nBOR. Response latency measurements implied that there might be at least two pathways from the nBOR to the nucleus rotundus, one being a direct excitatory pathway and the other an indirect inhibitory pathway possibly mediated by the subpretectal nucleus and the interstitio-pretecto-subpretectal nucleus, which have been thought to send inhibitory afferents to the nucleus rotundus. Taken together with previous neuroanatomical and immunocytochemical studies, it is suggested that modulatory interactions might exist between the nBOR and the nRt in particular and between the accessory optic system and the tectofugal pathway in general in birds.

Glutamatergic neurotransmission from the optic tectum to the contralateral nucleus rotundus in pigeons

Neuronal responses of 114 cells to electrical stimulation of the optic tectum were extracellularly recorded from the contralateral nucleus rotundus (nRt) in pigeons (Columba livia), and the effects of two glutamatergic antagonists CNQX and CPP, as well as those of GABA, were examined on rotundal cells. The results show that tectal stimulation evokes excitation in neurons of the contralateral nRt and that the excitatory responses are blocked by microiontophoretically applied CNQX, CPP and GABA. It is suggested that the contralateral tectorotundal transmission is excitatory in nature and mediated by both glutamatergic AMPA and NMDA receptors and that GABA is an inhibitory transmitter within the nucleus as well. We also review our previous findings in discussing transmitters participating in the tectofugal pathway.

Serum and milk lactoferrin concentration and the correlation with some blood components in lactating sows

An increased serum concentration of lactoferrin is associated with inflammatory disease, but there are few reported data on this aspect for lactating sows. Samples of blood and milk were collected from 17 lactating sows under minimum stress conditions and analysed for lactoferrin. Lactoferrin concentrations in serum and milk were positively correlated, being high after farrowing and steadily decreasing throughout 28 days of lactation. A positive linear correlation was observed between lactoferrin concentration and enzyme activities of alanine aminotransferase, lactate dehydrogenase, and hydroxybutyrate dehydrogenase in the serum indicating post-partum inflammation. Serum and milk lactoferrin concentrations, although closely correlated, may be regulated through independent systems activated simultaneously.

Excitatory and inhibitory receptive fields of tectal cells are differentially modified by magnocellular and parvocellular divisions of the pigeon nucleus isthmi

It has been known that magnocellular and parvocellular divisions of the pigeon nucleus isthmi exert excitatory and inhibitory actions on tectal cells, respectively. The present study shows that injection of N-methyl-D-aspartate into the parvocellular division results in an increase in responsive strength and extent of the inhibitory receptive fields, which expand into the excitatory receptive fields of tectal cells. This injection concurrently leads to a decrease in responsiveness and extent of the excitatory fields. On the other hand, injection of acetylcholine into the magnocellular division enhances visual responsiveness, although the excitatory field is not obviously changed in extent. Meanwhile, strength and extent of the inhibitory fields are decreased by acetylcholine. The excitatory and inhibitory fields are reduced in both strength and extent by magnocellular and parvocellular injection of lidocaine, respectively. It suggests that isthmic inputs from both parvocellular and magnocellular divisions converge onto the same tectal cells, and the magnocellular and parvocellular subnuclei can modulate excitatory and inhibitory receptive fields of tectal cells, respectively, with some interactions between both fields.

Developmental changes of NADPH-diaphorase positive structures in the isthmic nuclei of the chick

Nicotine adenine dinucleotide phosphate-diaphorase staining was used to study nitric oxide synthase activity and distribution in the midbrain visual structures of white leghorn chick embryos and post-hatched chickens. Enzyme staining first appeared in the isthmic region at the tenth embryonic day (E10) in the neuropil of the nucleus isthmi, pars parvocellularis. At E11 faint enzyme positivity appeared also in the nucl. isthmi pars magnocellularis, the nucl. semilunaris and the nucl. isthmo-opticus. The staining intensity of the isthmic nuclei dramatically increased between the 12.5th and the 13th days of incubation. The nucl. isthmi, pars parvocellularis showed the strongest enzyme reaction throughout embryonic life. A day before hatching all the isthmic nuclei were heavily stained, however, nicotine adenine dinucleotide phosphate-diaphorase-positive cells occurred exclusively in the nucleus isthmo-opticus. In the tectum opticum, intensely stained cells occupied the stratum fibrosum et griseum superficiale. The layer containing the projection neurons to the isthmo-optic nucleus was unstained. In the isthmic region, the intensity of staining surpassed that of the tectum and reached its maximum at E17 and then slowly decreased till the end of the experimental period (120 days post-hatched). The tractus isthmo-opticus showed nicotine adenine dinucleotide phosphate-diaphorase activity throughout the investigated period of life of the chicken, but the tractus tectoisthmo-opticus was unstained. Our results suggest that in the isthmic nuclei, nicotine adenine dinucleotide phosphate-diaphorase-positive neurons occur only in the isthmo-optic nucleus and optic tectum. The other positively stained structures are the fibers and terminals of tectal cells. In most brain areas nicotine adenine dinucleotide phosphate-diaphorase indicates nitric oxide synthase that produces nitric oxide. The transient appearance of this molecule is probably necessary for neuronal differentiation or the establishment of synaptic connections in the isthmic nuclei, and these developmental changes are under the control of the optic tectum.

[Action of fengsuidan granules on experimental anti-oral ulcer]

OBJECTIVE

To explore the anti-oral ulcer action, anti-inflammatory and analgesic effect of Fengsuidan Granules(FSDG).

METHODS

FSDG(0.5, 5.0, 10.0 g.kg-1) were administered to experimental animals. The oral ulcer in experimental animals was effected by means of white staphylococcus (sc) and carbolic acid (buming).

RESULTS

Such as acetic acid body turning, hot-plate, auricle inflammation by dimethylbenzene and foot swelling by egg white were used.

CONCLUSION

Following certain regularities of dose-effect relationship, FSDG has anti-oral ulcer effect, helps reduce and heal the ulcer and works efficaciously in analgesic and anti-inflammatory cases.

Complementary DNA cloning and immunologic characterization of a new Penicillium citrinum allergen (Pen c 3)

BACKGROUND

Penicillium citrinum has been identified as the most prevalent airborne Penicillium species in the Taipei area. It is important to understand the allergenic composition of this ubiquitous fungal species.

OBJECTIVE

The complementary DNA (cDNA) clone of an allergen from P citrinum was isolated and expressed in Escherichia coli as a fusion protein. mAbs were prepared with the recombinant protein as antigen. The corresponding natural allergen in the fungal extracts was identified with the mAbs.

METHODS

A Uni-Zap XR P citrinum cDNA library was screened with sera from asthmatic patients. An IgE-binding cDNA clone was isolated and expressed as a glutathione-S-transferase fusion protein. The frequency of IgE binding to the expressed protein was analyzed by immunoblotting. Spleen cells from BALB/c mice immunized with the recombinant protein were fused with NS-1 cells for mAb generation.

RESULTS

A P citrinum cDNA library was screened with a mixture of serum samples from 4 asthmatic patients. An IgE-binding cDNA clone was obtained and designated as PCE2. PCE2 has a 694-bp insert that contains a 167 amino acids open reading frame. The deduced amino acid sequence of the encoded protein has 82.6% (138 amino acids) identity with an Aspergillus fumigatus peroxisomal membrane protein allergen (Asp f 3). PCE2 was expressed in E coli as a fusion protein and designated as Pen c 3. Sera from 13 (46%) of the 28 Penicillium-sensitized asthmatic patients demonstrated IgE binding to Pen c 3. In addition, 11 of the 13 Pen c 3-positive serum samples have IgE immunoblot reactivity to recombinant Asp f 3. The presence of IgE cross-reactivity between Pen c 3 and Asp f 3 was also detected by immunoblot inhibition. Four of the 6 mAbs generated against Pen c 3 cross-react with Asp f 3. The presence of the corresponding 18-k natural allergens in the crude extracts of P citrinum and A fumigatus were detected by immunoblot with use of the mAbs and sera from asthmatic patients.

CONCLUSION

Results obtained suggest that the peroxisomal membrane protein (Pen c 3) is an important allergen of P citrinum. PCE2 is a full-length cDNA clone encoding this allergen. In addition, the mAbs generated may be useful in standardizing the diagnostic allergenic extracts.

Relationship between nutritional status and the glomerular filtration rate: results from the MDRD study

BACKGROUND

The relationship between the protein-energy nutritional status and renal function was assessed in 1785 clinically stable patients with moderate to advanced chronic renal failure who were evaluated during the baseline phase of the Modification of Diet in Renal Disease Study. Their mean +/- SD glomerular filtration rate (GFR) was 39.8 +/- 21.1 mL/min/1.73 m2.

METHODS

The GFR was determined by 121I-iothalamate clearance and was correlated with dietary and nutritional parameters estimated from diet records, biochemistry measurements, and anthropometry.

RESULTS

The following parameters correlated directly with the GFR in both men and women: dietary protein intake estimated from the urea nitrogen appearance, dietary protein and energy intake estimated from dietary diaries, serum albumin, transferrin, percentage body fat, skinfold thickness, and urine creatinine excretion. Serum total cholesterol, actual and relative body weights, body mass index, and arm muscle area also correlated with the GFR in men. The relationships generally persisted after statistically controlling for reported efforts to restrict diets. Compared with patients with GFR > 37 mL/min/1.73 m2, the means of several nutritional parameters were significantly lower for GFR between 21 and 37 mL/min/1.73 m2, and lower still for GFRs under 21 mL/min/1.73 m2. In multivariable regression analyses, the association of GFR with several of the anthropometric and biochemical nutritional parameters was either attenuated or eliminated completely after controlling for protein and energy intakes, which were themselves strongly associated with many of the nutritional parameters. On the other hand, few patients showed evidence for actual protein-energy malnutrition.

CONCLUSIONS

These cross-sectional findings suggest that in patients with chronic renal disease, dietary protein and energy intakes and serum and anthropometric measures of protein-energy nutritional status progressively decline as the GFR decreases. The reduced protein and energy intakes, as GFR falls, may contribute to the decline in many of the nutritional measures.

Feature detection of visual neurons in the nucleus of the basal optic root in pigeons

Previous studies have shown that the nucleus of the basal optic root in birds is involved in optokinetic nystagmus, and its neurons respond not only to large-field stimuli but also to a single object moving through their excitatory receptive fields. The present study provides electrophysiological evidence that basal optic neurons in pigeons respond vigorously to motion of a black leading edge. The orientation of the edge is also an essential factor affecting visual responses of these cells, showing that any deviation of the edge from the direction perpendicular to the preferred direction decreases visual responses in most cases. Furthermore, visual responses increase as the edge is lengthened within the excitatory receptive field. However, a square, semicircle and isosceles with an area ratio of 1.00: 0.39: 0.50 but with an identical leading edge elicit almost the same responses, which are not dependent on the shape and area of visual stimuli. It suggests that these feature extraction properties, similar to those of neurons in the nucleus lentiformis mesencephali, may be specialized for detecting optokinetic stimuli rich in luminance contrasts, but not for realizing pattern recognition.

Electrical interaction between neurons in the pigeon isthmo-optic nucleus

The present study used brain slices to investigate interneuronal communication in the isthmo-optic nucleus in pigeons. Electrical stimulation of the isthmo-optic tract generated a transmembrane potential in isthmo-optic cells that was obtained by subtracting the extracellular potential from the intracellular potential. This transmembrane potential resulted in enhancement of excitability and/or in production of spikes in 42 (63%) cells. In most cases, proximal axons marked in brain slices by Lucifer yellow were too short to reach the stimulation site, indicating that spikes were evoked by electrical field effect or ephaptic interaction produced by nearby cells whose axons were activated by stimulation. Eleven (16%) cells discharged a spikelet, or spike that was abolished by hyperpolarizing current injection leaving a spikelet. Markings of five of these cells all indicated the presence of dye-couplings, each of which consisted of a pair of cells. Fourteen (21%) cells only produced antidromic spikes with a short and constant latency. Four of these cells were marked and their axons passed through the stimulation site, implying that their nearby cells' axons might be cut too short to be electrically stimulated or they were in a sparse-cell area. The present results provide electrophysiological and neuroanatomical evidence that both electrical field effect and electrical coupling may play important roles in interneuronal communication within the pigeon isthmo-optic nucleus. These findings are supported by anatomical arrangement of densely packed cells and their oriented dendrites in this centrifugal nucleus.

Dual actions of isthmic input to tectal neurons in a reptile, Gekko gekko

We analyzed postsynaptic potentials and dye-labeled morphology of tectal neurons responding to electrical stimulation of the optic nerve and of the nucleus isthmi in a reptile, Gekko gekko, in order to compare with previously reported interactions between the optic tectum and the nucleus isthmi in amphibians and birds. The results indicate that isthmic stimulation exerts inhibitory and excitatory actions on tectal cells, similar to dual isthmotectal actions in amphibians. It appears that dual actions of the isthmotectal pathway in amphibians and reptiles are shared by two subdivisions of the nucleus isthmi in birds. The morphology of tectal cells responding to isthmic stimulation is generally similar to that of tectoisthmic projecting neurons, but they differ particularly in that some tectoisthmic cells bear numerous varicosities whereas cells receiving isthmic afferents do not. Thus, it is likely that at least some tectoisthmic cells may not be in the population of tectal cells that can be affected by isthmic stimulation. Forty-four percent of injections resulted in dye-coupled labeling, suggesting extensive electrical connections between tectal cells in reptiles.

Alkaline serine proteinase is a major allergen of Aspergillus flavus, a prevalent airborne Aspergillus species in the Taipei area

BACKGROUND

Aspergillus species are prevalent indoor airborne fungi and have been identified to be a causative agent of human allergic disorders. In the present study, we identified, purified and characterized the allergen(s) from Aspergillus flavus, a predominant airborne Aspergillus species in the Taipei area.

METHODS

The IgE-binding components of A. flavus were identified by SDS-PAGE immunoblotting with sera from asthmatic patients. The N-terminal amino acid sequences of the major allergens were determined by Edman degradation. The allergenic cross-reactivity among allergens from different fungi was analyzed by immunoblot inhibition using sera from asthmatic patients. The detected major allergen was purified from the culture medium. It was further characterized in terms of its N-terminal amino acid sequence, its IgE-binding activity and its enzymatic activity.

RESULTS

The results of the immunoblot analysis indicate that a 34-kD component that has high IgE-binding (63%) frequency is a major allergen of A. flavus. The N-terminus of this 34-kD major allergen (GLTTQKSAP) has high sequence identity with that of the 34-kD alkaline serine proteinase major allergen of A. oryzae. Results from immunoblot inhibition studies indicate that IgE cross-reactivity occurs among the 34-kD major allergens of A. flavus, A. fumigatus and Penicillium citrinum. The 34-kD major allergen of A. flavus was purified from the culture medium by ammonium sulfate precipitation and DEAE ion exchange chromatography. The N-terminal amino acid sequence of the purified allergen (Asp fl 13) is identical to that determined previously for the 34-kD major allergen in the crude extract of A. flavus. The IgE immunoblot reactivity to the 34-kD major allergen in the crude extract can be dose-dependently inhibited by the purified Asp fl 13. The degree of IgE binding to the 34-kD major allergen in the crude extract correlates with that of the purified Asp fl 13 in sera of 8 asthmatic patients. The purified Asp fl 13 has proteolytic activity with casein as substrate at pH 8.0. This enzymatic activity can be inhibited by either phenylmethylsulfonyl fluoride or diethylpyrocarbonate.

CONCLUSION

Our results suggest that the 34-kD alkaline serine proteinase is a major allergen of A. flavus. There was IgE cross-reactivity among allergens of A. flavus, A. fumigatus and P. citrinum.

Tectal afferents monosynaptically activate neurons in the pigeon isthmo-optic nucleus

Postsynaptic responses of 105 neurons in brain slices were intracellularly recorded from the isthmo-optic nucleus (ION) in pigeons, and 18 of these neurons were labeled with Lucifer yellow. Excitatory postsynaptic potentials (EPSPs) or spikes were produced in 93 cells, inhibitory postsynaptic potentials (IPSPs) in 10 cells, and EPSPs followed by IPSPs in two cells following electrical stimulation of the tecto-isthmooptic tract. The EPSPs occurred in an all-or-none fashion, with short latencies (1.3 +/- 0.6 ms). Repetitive stimulation increased their amplitude and duration, demonstrating that temporal summation was involved. Neurons producing excitatory responses were distributed throughout cellular layers of the nucleus. Pure IPSPs had a latency of 3.9 +/- 2.3 ms, and cells that responded in this manner were only distributed in the rostral portion of the nucleus. In the remaining two cells with EPSP-IPSP responses, the latency of excitatory responses was 1.5 ms in one cell and 1.4 ms in the other, and that of inhibitory responses was, respectively, 5.1 and 4.1 ms. Thus, it appeared that excitation was monosynaptic, whereas inhibition may be polysynaptic. Four single injections resulted in dye-coupled labeling, and two pairs of closely apposed cells fired spikes, probably resulting from spatial summation of their excitatory responses. The present study suggests that tectal cells directly activate ION neurons and that tectal fibers contact isthmo-optic neurons in a one-to-one fashion. Taken together with previous studies, it appears that the entire tecto-ION-retinal pathway is excitatory.

Receptive field characteristics of neurons in the nucleus of the basal optic root in pigeons

Optokinetic nystagmus is a reflex to stabilize an object image on the retina by compensatory eye movements. In lower vertebrates, the nucleus of the basal optic root participates in generating this reflex. Visual responses of 135 neurons were extracellularly recorded from the nucleus in pigeons and their receptive field properties were analysed on-line with a workstation. These cells could be categorized into slow (84%), intermediate (3%) and fast (13%) cells, preferring motion velocities of 0.25-8, 16 and 32-64 deg./s, respectively. Using whole-field gratings as stimuli revealed that 97% of the cells were selective for direction of motion and 3% were not. The directional cells preferred motion in the dorsoventral (35%), nasotemporal (34%), ventrodorsal (23%), or temporonasal (8%) directions. The omni-directional neurons were equally excited or inhibited by motion in all directions. The receptive field of basal optic neurons usually consisted of an excitatory receptive field and an inhibitory receptive field, both of which possessed opposite (heterodirectional) or identical (homodirectional) directionalities. In the case of homodirectional co-existence of both fields, whether whole-field gratings could produce visual responses from the cells would depend on the interaction between excitation and inhibition evoked in their excitatory and inhibitory receptive fields, respectively. Therefore, in some cases a single object was more effective than whole-field gratings in eliciting visual responses from basal optic neurons in pigeons. All of these receptive field properties revealed by on-line computer analysis may underlie the detection of optic flow and the induction of optokinetic responses.

Characterization of allergens from Penicillium oxalicum and P. notatum by immunoblotting and N-terminal amino acid sequence analysis

BACKGROUND

Penicillium species are important causative agents of extrinsic bronchial asthma. However, little is known about the allergens of these ubiquitous fungal species. Objective The object was to analyse the composition, the allergenic cross-reactivity and the N-terminal sequences of allergens from two prevalent airborne Penicillium species, P. oxalicum and P. notatum.

METHODS

The allergenic composition and the immunoglobulin (Ig)E cross-reactivity were analysed by immunoblot and immunoblot inhibition, respectively, using sera from asthmatic patients. The N-terminal amino acid sequences of major allergens were determined by Edman degradation. Allergens identified were also characterized by immunoblotting using monoclonal antibody (MoAb) PCM39 against the alkaline serine proteinase major allergen of P. citrinum.

RESULTS

Among the 70 asthmatic sera tested, 18 (26%) and 17 (24%) had IgE immunoblot reactivity towards components of P. oxalicum and P. notatum, respectively. Major allergens (> 80% frequency of IgE-binding) from both species are the 34 and 30 kDa proteins of P. oxalicum and the 34 and 32 kDa proteins of P. notatum. IgE cross-reactivity among these major allergens and the 33 kDa major allergen of P. citrinum can be detected by immunoblot inhibition studies. The N-terminal amino acid sequences of the 34 kDa allergen of P. oxalicum and of the 32 and the 28 kDa allergens of P. notatum share homology with sequences of the vacuolar serine proteinase from Aspergillus fumigatus. The N-terminal amino acid sequence of the 34 kDa allergen of P. notatum shows sequence homology with that of alkaline serine proteinase from P. citrinum. Results obtained from immunoblotting showed that MoAb PCM39 reacted with the 34, 30 and 16 kDa IgE-binding components of P. oxalicum, and with the 34, 32 and 28 kDa IgE-binding components of P. notatum.

CONCLUSIONS

Results obtained suggest that the 34 kDa major allergen of P. oxalicum may be a vacuolar serine proteinase. The 34 and the 32 kDa major allergens of P. notatum may be the alkaline and the vacuolar serine proteinases of P. notatum, respectively. The 30 and 16 kDa IgE-binding components of P. oxalicum and the 28 kDa IgE-binding component of P. notatum may be breakdown products of the 34 and the 32 kDa major vacuolar serine proteinase allergens of P. oxalicum and P. notatum, respectively.

Effects of glutamatergic, cholinergic and gabaergic antagonists on tectal cells in toads

The present paper using microiontophoresis analysis describes transmitters and their receptor subtypes used in retinotectal and isthmotectal transmission, and suggests several modes converging retinotectal and isthmotectal afferents on tectal neurons in toads (Bufo bufo gargarizans). Neuronal responses of tectal cells were extracellularly recorded to both visual stimulation and electrical stimulation of the nucleus isthmi, and effects of glutamatergic, cholinergic, GABAergic and glycinergic antagonists on these responses examined. Visual responses in 80% of tectal cells were reversibly blocked by the N-methyl-D-aspartate antagonist 3-Rs-2-carboxypiperazin-4-yl-propyl-1-phosphonic acid, and those of the remaining 20% of cells by the muscarinic antagonist atropine, suggesting that there may be at least two kinds of retinotectal synapse that use glutamate and N-methyl-D-aspartate receptors, and acetylcholine and muscarinic receptors, respectively. Electrical stimulation of the nucleus isthmi elicited excitatory responses in 67% of tectal cells, excitatory-inhibitory responses in 16% of cells, and inhibitory responses in 17% of cells examined. The excitatory responses were reversibly abolished by atropine, but not affected by either 3-Rs-2-carboxypiperazin-4-yl-propyl-1-phosphonic acid or the alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate antagonist 6-cyano-7-nitroquinoxaline-2,3-dione, whereas the inhibitory responses were released by the GABA receptor A antagonist bicuculline, but not influenced by the GABA receptor B antagonist 2-hydroxysaclofen and glycinergic antagonist strychnine. Excitatory and inhibitory components in the excitatory-inhibitory responses were blocked by atropine and bicuculline, respectively. It appears that glutamatergic and cholinergic afferents from the retina, and cholinergic and GABAergic afferents from the nucleus isthmi may converge on tectal neurons in at least five modes of synaptic connections, in agreement with the heterogeneous populations of tectal cells in amphibians.

Localization and source of gamma aminobutyric acid immunoreactivity in the isthmic nucleus of the frog Rana esculenta

The distribution of gamma-aminobutyric acid (GABA)-containing neurons and nerve fibers was studied in the isthmic nucleus of the frog Rana esculenta using light and electron microscopical immunohistochemical techniques. Approximately 0.5% of isthmic cells showed GABA immunopositivity, and the majority of these cells was found in the anterior one-third of the nucleus. A meshwork of GABA-immunostained fine beaded axons filled the entire isthmic nucleus. The GABA-immunoreactive terminals formed pericellular basket-like structures around a few cells both in the medulla and the cortex of the isthmic nucleus. To determine the source of GABA-positive fibers in the isthmic nucleus lesion experiments were carried out. After unilateral tectal ablation no change was observed in GABA immunoreactivity. Hemisectioning the tegmentum close to the anterior border of the isthmic nucleus, transection of the caudal tectal commissure and decussatio veli, or electrical lesioning of the anterodorsal tegmental nucleus all resulted in a moderate decrease in the density of GABA-positive fibers. Our results suggest that the majority of GABA-positive fibers derives from local GABA-positive cells, but some GABAergic afferents seem to arise in the tegmentum.

Stimulus features eliciting visual responses from neurons in the nucleus lentiformis mesencephali in pigeons

The purpose of the present study was to find out what particular stimulus features, in addition to the direction and velocity of motion, specifically activate neurons in the nucleus lentiformis mesencephali (nLM) in pigeons. Visual responses of 60 nLM cells to a variety of computer-generated stimuli were extracellularly recorded and quantitatively analyzed. Ten recording sites were histologically verified to be localized within nLM with cobalt sulfide markings. It was shown that the pigeon nLM cells were specifically sensitive to the leading edge moving at the optimal velocity in the preferred direction through their excitatory receptive fields (ERFs). Generally speaking, nLM cells preferred black edges to white ones. However, this preference cannot be explained by OFF-responses to a light spot. The edge sharpness was also an essential factor influencing the responsive strength, with blurred edges producing little or no visual responses at all. These neurons vigorously responded to black edge orientated perpendicular to, and moved in, the preferred direction; the magnitude of visual responses was reduced with changing orientation. The spatial summation occurred in all neurons tested, characterized by the finding that neuronal firings increased as the leading edge was lengthened until saturation was reached. On the other hand, it appeared that nLM neurons could not detect any differences in the shape and area of stimuli with an identical edge. These data suggested that feature extraction characteristics of nLM neurons may be specialized for detecting optokinetic stimuli, but not for realizing pattern recognition. This seems to be at least one of the reasons why large-field gratings or random-dot patterns have been used to study visual responses of accessory optic neurons and optokinetic nystagmus, because many high-contrast edges in these stimuli can activate a neuron to periodically discharge, or groups of neurons to simultaneously fire to elicit optokinetic reflex.

Tegmental inhibition on isthmic neurons is mediated by the decussatio veli in amphibians

This in vitro study on toads (Bufo bufo gargarizans) provides the first electrophysiological evidence that electrical stimulation of the decussatio veli in the midbrain tegmentum predominantly produced inhibition on neurons extracellularly recorded from the nucleus isthmi (NI). These cells were distributed throughout the nucleus. The present study lends strong support to the suggestion that the extratectal input to NI is mainly inhibitory and gives a good explanation for the previously reported inhibition of isthmic neurons by the contralateral optic nerve stimulation (Wu and Wang, 1995a).

Normal pressure hydrocephalus in a patient with systemic lupus erythematosus: a case report

Neuropsychiatric symptoms in systemic lupus erythematosus (SLE) are varied. The exact etiology and appropriate treatment are difficult to determine. We describe a 43-year-old woman who was diagnosed 18 years earlier with SLE. She developed dementia, gait disturbance, urinary incontinence and deterioration of consciousness. Her cerebrospinal fluid pressure was not elevated. Brain computerized tomography scan revealed enlarged ventricle and cortical sulci. Normal pressure hydrocephalus (NPH) was diagnosed. She was treated by establishing a ventriculo-peritoneal shunt, resulting in the return of normal consciousness. But she still had slurred speech, slow mentation and poor calculation ability. Her urinary incontinence persisted. Along with a literature review on NPH, we discuss its etiology, diagnosis and treatment.

Characterization and functional analysis of the porcine lactoferrin gene promoter

Lactoferrin, a ferric binding glycoprotein found in milk, can possibly prevent microbial infection of the mammary gland and gastrointestinal tract. To define the regulation of the porcine lactoferrin gene (pLTF), we cloned its 5'-flanking region from a porcine liver genomic library and analyzed the 5' upstream region of approx. 4kb, two exons, and an intron. The transcription start site was localized by primer extension to residue G, which is 41 nucleotides upstream from the ATG start codon. The pLTF 5'-flanking region possesses several putative cis-acting regulatory elements found in both housekeeping and inducible genes; to define their function, they were inserted into a chloramphenicol acetyltransferase reporter construct. The region up to -156 sufficed for basic promoter activity, whereas the region up to -780 was required for maximal promoter activity in porcine testis cells (STcells), kidney cells (PK15 cells) and human mammary epithelial cells (HBL-100 cells). Detailed analysis of this proximal region by DNase I footprinting and electrophoretic mobility shift assays reveals that the ubiquitous factors SP1, AP2 and the mammary gland-specific factor (MGF) might play significant roles in regulating the transcription of the pLTF gene.

Differences between women and men with chronic renal disease

BACKGROUND

The purpose of the present study was to compare the participation of women and men in the protocols of the Modification of Diet in Renal Disease (MDRD) study, a multicenter prospective randomized clinical trial, and to assess gender differences in their renal outcomes.

METHODS

Of the 840 participants in the MDRD study, 332 (39.5%) were women who were assigned randomly to the dietary protein and blood pressure groups and followed for a median of 2.2 years. A subgroup analysis of the MDRD study database was carried out to compare women and men participants in recruitment, baseline characteristics, adherence to protocol requirements, safety and outcomes, and progression of renal disease and its response to dietary and blood pressure interventions.

RESULTS

Adherence by women to the requirements of the protocol including diet, record keeping, office visits, glomerular filtration rate (GFR) measurements and urine collections was equivalent to that of men. Women had different renal diagnoses, less proteinuria and lower serum creatinine levels for given GFRs than men. When participants were grouped above and below age 52, the younger women had lower mean arterial pressure than did the men. Older women compared with younger had higher mean arterial pressure, body weight and body mass index, and total low density lipoprotein cholesterol. These differences were not seen between males of the same two age groups. During follow-up, the rate of GFR fall was slower in women, especially in the younger group. However, the association between gender and the rate of fall in GFR was attenuated and became non-significant after adjusting for differences in blood pressure, proteinuria and high density lipoprotein cholesterol. In analyses of the full cohort, there were no significant differences between women and men in the effects of the low protein or low blood pressure intervention in patients with either moderate (study A) or advanced (study B) renal disease. However, in subgroup analyses of patients in study A, there was some evidence of a lesser effect in women than in men.

CONCLUSIONS

This exploratory analysis of the MDRD study indicates a slower mean GFR decline in women as compared with men. The slower mean GFR decline and suggestive evidence of a lesser beneficial effect of the low protein diet and low blood pressure interventions in women suggest that gender differences should be considered in trials of the effects of these interventions on the progression of renal disease. Also, the participation of women in the MDRD study was excellent and equivalent to that of men.