Expression and Coexpression of CO 2 -sensitive Kir Channels in Brainstem Neurons of Rats

Several inward rectifier K(+) (Kir) channels are inhibited by hypercapnic acidosis and may be involved in CO(2) central chemoreception. Among them are Kir1.1, Kir2.3, and Kir4.1. The Kir4.1 is expressed predominantly in the brainstem. Although its CO(2) sensitivity is low, coexpression of Kir4.1 with Kir5.1 in Xenopus oocytes greatly enhances the CO(2)/pH sensitivities of the heteromeric channels. If these Kir channels play a part in the central CO(2) chemosensitivity, they should be expressed in neurons of brainstem cardio-respiratory nuclei. To test this hypothesis, we performed in-situ hybridization experiments in which the expression of Kir1.1, Kir2.3, Kir4.1 and Kir5.1, and coexpression of Kir4.1 and Kir5.1 were studied in brainstem neurons using non-radioactive riboprobes. We found that mRNAs of these Kir channels were present in several brainstem nuclei, especially those involved in cardio-respiratory controls. Strong labeling was observed in the locus coeruleus, ventralateral medulla, parabrachial-Kölliker-Fuse nuclei, solitary tract nucleus, and area postrema. Strong expression was also seen in several cranial motor nuclei, including the nucleus of ambiguus, hypoglossal nucleus, facial nucleus and dorsal vagus motor nucleus. In general, the expression of Kir5.1 and Kir4.1 was much more prominent than that of Kir1.1 and Kir2.3 in all the nuclei. Evidence for the coexpression of Kir4.1 and Kir5.1 was found in a good number of neurons in these nuclei. The expression and coexpression of these CO(2)/pH-sensitive Kir channels suggest that they are likely to contribute to CO(2) chemosensitivity of the brainstem neurons.

Intraoperative parathyroid hormone assay and parathyroid reoperations

BACKGROUND

The purpose of this study was to determine whether intraoperative parathyroid hormone (IOPTH) assay improved results of reoperations.

METHODS

One hundred two patients with persistent/recurrent sporadic primary hyperparathyroidism underwent 108 reoperations (1996-2002). IOPTH was not used (n=58) from 1996-1998 (group 1). IOPTH was used (n=50) from 1999-2002 (group 2). Sensitivity and positive predictive value of IOPTH and its influence on surgical strategy were analyzed. A 50% decrease occurring 10 minutes after removal of parathyroid tumor was used to determine if all abnormal tissue had been removed.

RESULTS

Groups 1 (58 patients) and 2 (50 patients) were comparable except for duration of follow-up. The cure rate was 84% (group 1, 87%; group 2, 82%, P=0.7). Hypocalcemia developed in 20 patients (permanent in 2 patients). There was 1 permanent vocal cord paralysis and 1 patient died of toxic shock syndrome. IOPTH successfully predicted cure in 44 of 49 patients (sensitivity, 90%); the positive predictive value was 90%. Values for parathyroid hormone level and the ratio parathyroid hormone/calcium at day 1 were at least as accurate as IOPTH in predicting cure. IOPTH was helpful in 1 patient but misleading in 4 patients. It failed to modify intraoperative strategy in most other patients.

CONCLUSIONS

IOPTH testing was relatively reliable in patients with persistent or recurrent sporadic primary hyperparathyroidism, but the test unfortunately failed to improve the overall success rate at reoperation.

Measurement of intramyocellular lipid levels with 2-D magnetic resonance spectroscopic imaging at 1.5 T

Intramyocellular lipid (IMCL) plays an important role in the study of metabolism in vivo. Magnetic resonance spectroscopy (MRS) studies of IMCL are usually performed with clinical 1.5-T magnetic resonance imaging (MRI) systems and have employed the single-voxel MRS technique. The present study reports the results of our systematic evaluation of the ability of single- and multi-voxel MRS to yield high-quality, contamination-free IMCL levels from the tibialis anterior (TA) muscle. A clinical, 1.5-T, whole-body MRI scanner was used to measure IMCL with a standard knee coil, head coil, or a 3-cm receive-only surface coil with a body coil transmit. Excellent IMCL spectra were obtained in healthy males in only 8 min from multiple 0.25-cm(3) voxels using the surface coil receive/body coil transmit in conjunction with the standard PRESS spectroscopic imaging (SI) technique. This approach provided the spatial resolution and voxel placement flexibility permitting optimal separation of IMCL and extramyocellular lipid. Our findings demonstrate the potential of the SI approach.

The regulatory network controlling beta-globin gene switching

The human globin gene cluster, which represents a prototypical eukaryotic multigene locus, has been investigated for more than two decades and is classic model for coordinate control of tissue-specific gene expression. It is well known that globin gene expression is restricted to specific tissues and that globin genes are sequentially switched on during development. What intricate regulatory mechanisms account for tissue-specific transcriptional control of globin gene expression? Previous studies have focused on the interactions of trans-acting factors and cis-acting elements including the locus control region (LCR), which is considered a potent enhancer in globin gene switching. More recent studies have not only focused on the local DNA regulatory elements but also on remodelling of chromatin and transcription at the globin gene cluster within the native genomic context. Moreover, several studies have presented extensive data that address whether the LCR is required to open the chromatin. Although there is increased insight into the regulation of the beta-globin gene switching, many aspects relating to the developmental activation of distinct globin genes remain elusive.

Potential long-term inhibition of ocular neovascularisation by recombinant adeno-associated virus-mediated secretion gene therapy

Neovascularisation (NV) within the eye often results in visual loss. Vascular endothelial growth factor (VEGF) has been implicated in the development of ocular NV. Previous studies have shown that VEGF antagonists successfully suppressed retinal and choroidal NV in animal models. However, the systemic approach and transient nature of the delivery systems used in these studies hinder therapeutic application. To achieve stable and localised ocular anti-angiogenic therapy, we explored the use of recombinant adeno-associated virus (rAAV)-mediated secretion gene therapy (SGT). In this study, we generated a rAAV vector encoding soluble VEGF receptor 1, sFlt-1 (AAV-CMV.sflt) and determined its ability to inhibit cautery-induced corneal NV and laser-induced choroidal NV. Delivery of AAV-CMV.sflt into the anterior chamber resulted in transgene expression in the iris pigment epithelium and corneal endothelium, which reduced the development of corneal NV in the stroma of cauterised rats by 36% compared with cauterised control groups (P = 0.009). Subretinal delivery of AAV-CMV.sflt near the equator of the eye also suppressed choroidal NV at the laser lesions around the optic nerve by 19% (P = 0.002), indicating that there was diffusion of the secreted anti-angiogenic protein across the retina. Both results suggest that the long-term suppression of ocular NV is possible through the use of stable rAAV-mediated SGT.

A new high sensitivity thermoluminescent phosphor with low residual signal and good stability to heat treatment: LiF:Mg,Cu,Na,Si

The preliminary investigations are reported on the characteristics of a new, high-sensitivity thermoluminescence phosphor material (LiF:Mg,Cu,Na,Si) prepared in this laboratory. The main dosimetric peak of this phosphor occurs at 197 degrees C at a heating rate of 1 degrees C.s(-1). The glow curve shape shows minimal differences and sensitivity remains stable when annealed in the range from 250 to 280 degrees C for 10 min. Its TL sensitivity to gamma radiation is about 30 times higher than that of TLD-100 with a residual signal 0.2% following a 260 degrees C readout at a heating rate of 15 degrees C.s(-1). This negligible residual signal renders LiF:Mg,Cu,Na,Si usable in unannealed form. Its TL response at both 260 degrees C and 280 degrees C are reproducible within a coefficient of variation of 2% over ten re-use cycles without systematic decrease. It retains the main advantages of LiF:Mg,Cu,P phosphor, and has a lower residual signal and a better stability to heat treatment.

New advances in LiF:Mg,Cu,P TLDs (GR-200A)

In order to volume-produce LiF:Mg,Cu,P TLDs, increase the repeatability of preparation technology and further improve the features of TLDs, especially the moisture resistant property and the accuracy in ultra-low dose, the prescription and preparation techniques have been investigated further in recent years. The main features of GR-200A have been improved dramatically by adding a chemical additive and adopting a particular preparation technology. Recent improvements are presented including prescription, preparation technology, TL sensitivity, signal-to-noise rate, detection threshold, residual signal, the moisture resistant property and the uncertainty in low dose measurements. The sensitivity of GR-200A has been increased to 65 times as high as TLD-100 from the original 29 times. The residual signal has been decreased to less than 1% from the original of about 2.5% following 240 degrees C readout. The detection threshold decreases and the signal-to-noise ratio increases. The uncertainty in low dose measurements is reduced significantly. The resistance to humidity has been improved remarkably. The preparation technology to volume-produce GR-200A is stable.

Influence of readout parameters on TL response, re-usability and residual signal in LiF:Mg,Cu,P

It has recently been recommended that heating rates do not exceed 10 K.s(-1) and that the maximum temperature of readout should not exceed 265 degrees C for LiF:Mg,Cu,P. In some cases, a decrease of sensitivity in this material in the first of several re-use cycles had been reported. Influence of heating rates up to 30 K.s(-1), duration time up to 40s and maximum readout temperatures up to 270 degrees C on TL response, re-usability and residual signal was investigated. It was found that the maximum readout temperatures above 240 degrees C may lead to the thermoluminscent response decrease in the first several re-use cycles. The readout parameters can be optimised to minimise the residual signal (less than 0.4%) and to retain a constant sensitivity at the same time at high heating rates up to 30 K.s(-1) in a short time (less than 1 min per TL chip) without the necessity of heating above 240 degrees C. A concept of 'efficient residual signal' was put forward to quantify more accurately the real residual signal which affects the precision of the next measurement.

Comparative study of trapping parameters and repeatability of LiF:Mg,Cu,P (GR-200A) from different production batches

Distinct differences in repeatability between two different production batches had been observed. The results are presented of an investigation into the change of sensitivity of LiF:Mg,Cu,P originating from 7 different production batches prepared during 1994 to 2000 after repeated usage. Computerised glow curve analysis has been used to determine the trapping parameters of these thermoluminescent materials. The sensitivity in LiF:Mg,Cu,P for all investigated batches remains stable after repeated usage. The maxima of glow peaks 2 to 4 are found at the same temperature within very small limits. The activation energy and frequency of glow peaks 2 to 4 vary little from batch to batch. For all investigated peaks, no correlation has been found between glow sensitivity and trapping parameters. The peak areas of glow peaks 3 and 4 originating from 4 batches prepared during 1996 to 2000 are significantly larger than that of the other three batches. The GR-200A LiF:Mg,Cu,P has been improved dramatically in recent years.

The chemokine receptor CXCR4 enhances integrin-mediated in vitro adhesion and facilitates engraftment of leukemic precursor-B cells in the bone marrow

OBJECTIVE

It has been demonstrated that acute lymphoblastic leukemia (ALL) blasts migrate into layers of bone marrow fibroblasts (BMF) in vitro using the beta1 integrins VLA-4 and VLA-5, and that the chemokine SDF-1 and its receptor CXCR4 influences ALL migration. We investigated whether this effect was due to SDF-1-mediated induction of adhesion through beta1 integrins.

METHODS

Adhesion of pre-B ALL cells or the cell line NALM6 to extracellular matrix proteins was examined using short-term in vitro binding assays. The effects of exposure of cells to SDF-1, antibodies to CXCR4, and the G protein inhibitor pertussis toxin (PTX) were assessed. The consequences of down regulation of CXCR4 on the in vivo behavior of pre-B ALL cells after injection into sublethally irradiated NOD/SCID mice was studied.

RESULTS

Treatment with SDF-1 of NALM6 cells or cells from cases of precursor-B ALL resulted in a doubling of adhesion to fibronectin, laminin, and VCAM-1, but had no effect on binding to collagens I or IV. Antibodies to CXCR4 and PTX inhibited SDF-1-induced adhesion on these substrates. NALM6 cells with CXCR4 expression downregulated by SDF-1 exposure demonstrated a reduced capacity to engraft into the bone marrow of NOD/SCID mice, with only 22 +/- 11% of marrow cells being of human origin in mice receiving SDF-1-treated cells compared to 48 +/- 5% in mice receiving untreated cells (p < 0.001). The homing of SDF-1-treated cells to the bone marrow after 24 hours was also reduced by 72 +/- 16% compared to control cells.

CONCLUSIONS

These data show that SDF-1 and CXCR4 are involved in regulation of beta1 integrin function, and are important for the localization of pre-B cells to the bone marrow in vivo.

Steroid structure and pharmacological properties determine the anti-amnesic effects of pregnenolone sulphate in the passive avoidance task in rats

Pregnenolone sulphate (PREGS) has generated interest as one of the most potent memory-enhancing neurosteroids to be examined in rodent learning studies, with particular importance in the ageing process. The mechanism by which this endogenous steroid enhances memory formation is hypothesized to involve actions on glutamatergic and GABAergic systems. This hypothesis stems from findings that PREGS is a potent positive modulator of N-methyl-d-aspartate receptors (NMDARs) and a negative modulator of gamma-aminobutyric acid(A) receptors (GABA(A)Rs). Moreover, PREGS is able to reverse the amnesic-like effects of NMDAR and GABA(A)R ligands. To investigate this hypothesis, the present study in rats examined the memory-altering abilities of structural analogs of PREGS, which differ in their modulation of NMDAR and/or GABA(A)R function. The analogs tested were: 11-ketopregnenolone sulphate (an agent that is inactive at GABA(A)Rs and NMDARs), epipregnanolone ([3beta-hydroxy-5beta-pregnan-20-one] sulphate, an inhibitor of both GABA(A)Rs and NMDARs), and a newly synthesized (-) PREGS enantiomer (which is identical to PREGS in effects on GABA(A)Rs and NMDARs). The memory-enhancing effects of PREGS and its analogs were tested in the passive avoidance task using the model of scopolamine-induced amnesia. Both PREGS and its (-) enantiomer blocked the effects of scopolamine. The results show that, unlike PREGS, 11-ketopregnenolone sulphate and epipregnanolone sulphate failed to block the effect of scopolamine, suggesting that altering the modulation of NMDA receptors diminishes the memory-enhancing effects of PREGS. Moreover, enantioselectivity was demonstrated by the ability of natural PREGS to be an order of magnitude more effective than its synthetic enantiomer in reversing scopolamine-induced amnesia. These results identify a novel neuropharmacological site for the modulation of memory processes by neuroactive steroids.

Foxa3 (hepatocyte nuclear factor 3gamma ) is required for the regulation of hepatic GLUT2 expression and the maintenance of glucose homeostasis during a prolonged fast

The winged helix transcription factors, hepatocyte nuclear factors 3alpha, -beta, and -gamma (HNF-3, encoded by the Foxa1, -a2, and -a3 genes, respectively), are expressed early in embryonic endoderm and play important roles in the regulation of gene expression in liver and pancreas. Foxa1 has been shown to be required for glucagon secretion in the pancreas, whereas Foxa2 is critical for the regulation of insulin secretion in pancreatic beta-cells. Here we address the role of Foxa3 in the maintenance of glucose homeostasis. Mice homozygous for a null mutation in Foxa3 appear normal under fed conditions. However, when fasted, Foxa3(-/-) mice have a significantly lower blood glucose compared with control mice. The fasting hypoglycemia in Foxa3(-/-) mice could not be attributed to defects in pancreatic hormone secretion, ketone production, or hepatic glycogen breakdown. Surprisingly, mRNA levels for several gluconeogenic enzymes were up-regulated appropriately in fasted Foxa3(-/-) mice, despite the fact that the corresponding genes had been shown to be activated by FOXA proteins in vitro. However, the mRNA for the plasma membrane glucose transporter GLUT2 was decreased by 64% in the fasted and 93% in the fed state, suggesting that efflux of newly synthesized glucose is limiting in Foxa3(-/-) hepatocytes. Thus, Foxa3 is the dominating transcriptional regulator of GLUT2 expression in hepatocytes in vivo. In addition, we investigated the hepatic transcription factor network in Foxa3(-/-) mice and found that the normal activation of HNF-4alpha, HNF-1alpha, and PGC-1 induced by fasting is attenuated in mice lacking Foxa3.

Laboratory and field evaluation of Schistosoma japonicum DNA vaccines in sheep and water buffalo in China

Vaccines are needed to control zoonotic Schistosoma japonicum infection and several vaccine candidates have now been identified. Two of these (Sj28GST and Sj23) have shown particular promise in sheep when injected with Freund's adjuvants. The objective of the present work was to find a vaccine formulation which may have potential for widespread use in the field. DNA vaccine formulations of these antigens were produced and tested first in sheep under laboratory conditions and then in both the laboratory and the field in water buffalo. In both host species partial protection as evidenced by a reduction in parasite counts in vaccinated compared with control animals was induced by both vaccines, and in water buffalo the vaccines were shown to be partially protective in the field as well as in the laboratory. These results suggest that the two DNA vaccines tested here may have potential for large-scale field use.

Percutaneous transluminal stenting in patients with carotid artery stenosis

OBJECTIVE

To assess the efficacy and safety of percutaneous transluminal stenting for patients with carotid artery stenosis.

METHODS

Selective percutaneous transluminal stenting was performed for patients with symptomatic carotid artery stenosis (luminal narrowing > or = 70%). Success rates and complications associated with the procedures were observed. During six months of follow-up, both recurrent symptom and restenosis rates were recorded.

RESULTS

There were 17 bifurcating lesions among 27 stenoses in 26 patients, of whom 18 had concomitant coronary artery diseases. The acute procedural success rate was 96.3% (26/27), and the degree of stenosis was reduced from 88.6% +/- 8.9% (range 70-100) to 0.4% +/- 2.0% (range 0-10). Six patients developed severe bradycardia and hypotension, and 3 experienced transient loss of consciousness during balloon dilatation. During hospitalization, 2 patients experienced loss of consciousness and convulsion, respectively, due to hyperperfusion, and both recovered 12 hours later. There were 2 minor stroke cases (7.4%) but no cases of major stroke or death. At the 6-month follow-up, there were no cases of TIA or new onset of stroke. There was no restenosis detected in 16 cases using angiography and in 10 cases using MRI in 6 to 16 months of follow-up.

CONCLUSIONS

Percutaneous transluminal stenting for patients with carotid artery stenosis has a high procedural success rate with few and acceptable complications. Few patients suffered from recurrent symptoms or showed restenosis in long-term follow-up.

The relationship of health-related quality of life to prevalent and incident vertebral fractures in postmenopausal women with osteoporosis: results from the Multiple Outcomes of Raloxifene Evaluation Study

OBJECTIVE

To examine the effect of both prevalent and incident vertebral fractures on health-related quality of life (HRQOL) in postmenopausal women with osteoporosis and to characterize the effect of prevalent vertebral fractures on HRQOL with respect to number, location, severity, and adjacency.

METHODS

Participants were a subset of women (n = 1,395, mean age 68.5 years) from the Multiple Outcomes of Raloxifene Evaluation trial who had low bone mineral density and/or prevalent vertebral fractures. Vertebral fractures were measured by radiography at baseline, 2 years, and 3 years. HRQOL was assessed using the Osteoporosis Assessment Questionnaire (OPAQ), a validated disease-targeted instrument, at baseline and annually for 3 years.

RESULTS

Both prevalent and incident radiographic vertebral fractures were associated with decreased HRQOL. At baseline, women with a prevalent vertebral fracture had significantly lower OPAQ scores on physical function, emotional status, clinical symptoms, and overall HRQOL compared with women without a prevalent fracture (all P < 0.01). HRQOL scores were lower with each subsequent fracture. The effect of prevalent vertebral fracture was dependent on the location within the spine and was strongest in the lumbar region (L1-L4). Incident vertebral fractures significantly decreased OPAQ scores on physical function, emotional status, clinical symptoms, and overall HRQOL (all P < 0.001).

CONCLUSION

Our findings demonstrate the importance of treating postmenopausal women who have prevalent vertebral fractures to prevent further decreases in HRQOL associated with subsequent incident vertebral fracture.

[An outline of spreading of Western mediciine into Yantai in modern age]

At the turn of the last century, side by side with the infiltration of religious culture from Western countries, western medicine spread into Yantai. The religious force, headed by American Presbyterian Mission, carried out charitable activities in the process of preaching and laid down the foundation for western medicine rooted in Yantai by establishing schools, education and training followers. They cultivated local physicians by first setting up clinics which had later transformed into hospitals. These are their major measures for building bases for spreading Christianity by foreigners. The Temple Hill Hospital set up by the American physician Oscar F. Hills in Yantai was a successful example of mutual promotion of missionary and medical activities which pushed forward the spreading and development of western medicine in Yantai.

Effects on gamma-aminobutyric acid (GABA)(A) receptors of a neuroactive steroid that negatively modulates glutamate neurotransmission and augments GABA neurotransmission

Neurosteroids positively and negatively modulate gamma-aminobutyric acid (GABA)(A) receptors and glutamate receptors, which underlie most fast inhibition and excitation in the central nervous system. We report the identification of a neuroactive steroid, (3 alpha,5 beta)-20-oxo-pregnane-3-carboxylic acid (3 alpha 5 beta PC), with unique cellular actions. 3 alpha 5 beta PC positively modulates GABA(A) receptor function and negatively modulates N-methyl-D-aspartate (NMDA) receptor function, a combination that may be of particular clinical benefit. 3 alpha 5 beta PC promotes net GABA(A) potentiation at low steroid concentrations (<10 microM) and at negative membrane potentials. At higher concentrations, the steroid also blocks GABA receptors. Because this block would presumably counteract the NMDA receptor blocking actions of 3 alpha 5 beta PC, we characterize the GABA receptor block in some detail. Agonist concentration, depolarization, and high extracellular pH increase the block. The apparent pK for both potentiation and block was 6.4 to 6.9, substantially higher than expected from carboxylated steroid in an aqueous environment. Block is not dependent on the stereochemistry of the carboxylic acid at carbon 3 and is relatively insensitive to placement of the carboxylic acid at the opposite end of the steroid (carbon 24). Potentiation is critically dependent on the stereochemistry of the carboxylic acid group at carbon 3. Consistent with the pH dependence of potentiation, effects of the amide derivative (3 alpha,5 beta)-20-oxo-pregnane-3-carboxamide, suggest that the un-ionized form of 3 alpha 5 beta PC is important for potentiation, whereas the ionized form is probably responsible for block. Further refinement of the neuroactive steroid to promote GABA potentiation and NMDA receptor block and diminish GABA receptor block may lead to a clinically useful neuroactive steroid.

Heart rate variability and its response to thyroxine replacement therapy in patients with hypothyroidism

OBJECTIVE

To analyze heart rate variability (HRV) and its changes with thyroxine treatment in patients with hypothyroidism.

METHODS

HRV was analyzed using 24-hour electrocardiographic recording in 38 patients with hypothyroidism and 21 normal controls. The changes in HRV were evaluated for the 18 hypothyroid patients after 3 months of thyroxine therapy.

RESULTS

The time domain measurements of HRV in hypothyroid patients were much lower than those in the control group. As to HRV frequency domain, the high frequency power was significantly higher, but the ratio of low frequency power to frequency power for hypothyroid patients was lower than in the controls. These abnormal changes of HRV measurements in hypothyroid patients were improved after treatment with thyroxine and were associated with recovery of serum concentrations of FT3 and FT4.

CONCLUSIONS

Patients with hypothyroidism often have autonomic neuropathies with a higher level of vagal tone. These abnormalities could be partly improved by thyoxine therapy.

Uptake dynamics and retinal tolerance of phosphorothioate oligonucleotide and its direct delivery into the site of choroidal neovascularization through subretinal administration in the rat

This study aimed to investigate uptake dynamics and retinal tolerance of phosphorothioate oligonucleotides (PS-oligos) following subretinal injection. A fluorescent-labeled PS-oligo (FL-oligo) with random sequence was administered into the subretinal space of rat by transsclera-choroid-retinal pigment epithelium (RPE) injection at doses of 0.129, 1.29, and 12.9 microg in 2.0 microl solution. The uptake dynamics were evaluated by fundus fluorescent photography in real time and by fluorescence microscopy using flat mounts and cryosections. Immunophenotyping for CD4+, CD8+ cytotoxic lymphocytes, and CD68+ macrophages was performed to assess cellular infiltration in the retina. In addition, the FL-oligo was injected subretinally in a rat model of choroidal neovascularization (CNV) for direct delivery into the site of CNV. Subretinal administration of FL-oligo resulted in both dose-dependent and time-dependent distribution in the retina, where it accessed the RPE and all layers of the neuroretina. CD4+, CD8+ cytotoxic lymphocytes, and CD68+ macrophages were observed at the site of needle penetration. However, in areas far from the injection site where the FL-oligo appeared strongly, cellular infiltration was absent, and the retinal morphology was preserved very well. The FL-oligo was successfully delivered into the site of intense laser photocoagulation. It was predominantly localized to the RPE, macrophages, and some choroid cells and remained detectable for at least 56 days after injection. Our results demonstrate for the first time that subretinal injection efficiently introduced PS-oligo into the RPE and neuroretina with an acceptable level of safety. Subretinal administration of antiangiogenic oligonucleotides may hold great potential for the treatment of CNV.

Endogenous nitric oxide enhances coupling between O2 consumption and ATP synthesis in guinea pig hearts

Endogenous nitric oxide (eNO) modulates tissue respiration. To test whether eNO modulates myocardial O2 consumption (MVO2), ATP synthesis, and metabolic efficiency, we used isolated isovolumic guinea pig hearts perfused at a constant flow. N(omega)-nitro-L-arginine (L-NNA; 5 x 10(-5) mol/l) was used to inhibit eNO production. MVO2 was measured at different levels of cardiac work, estimated as the rate-pressure product (RPP). ATP content and synthesis rate were determined using (31)P NMR and magnetization transfer during high cardiac work. L-NNA increased coronary vascular resistance (19 +/- 3%, P < 0.05) and MVO2 (12 +/- 3%, P < 0.05) without an increase in the RPP. In contrast, vehicle infusion resulted in insignificant changes in coronary vascular resistance (3 +/- 2%, P > 0.05) and MVO2 (-2 +/- 1%, P > 0.05). Compared with vehicle, L-NNA caused a higher MVO2 both during KCl arrest (L-NNA 5.6 +/- 0.5 vs. vehicle 3.0 +/- 0.4 micromol x min(-1) x mg x dry wt(-1), P < 0.05) and during increased cardiac work elicited by elevating perfusate Ca2+, indicating an upward shift in the relationship between contractile performance (measured as RPP) and MVO2. However, neither ATP contents nor ATP synthesis rates were different in the two groups during high cardiac work. Thus, because inhibition of eNO production by L-NNA increased MVO2 without a change in the ATP synthesis rate, these data suggest that eNO increases myocardial metabolic efficiency by reducing MVO2 in the heart.

Prestin topology: localization of protein epitopes in relation to the plasma membrane

Computer modeling of the outer hair cell (OHC) motor protein prestin produces ambiguous results regarding transmembrane regions and localization of its termini. To determine the location of prestin's N- and C-termini, we created prestin constructs with synthetic epitopes located immediately upstream or downstream of prestin. The spatial distribution of these epitopes was studied in prestin-transfected cells using immunofluorescence. In permeabilized cells, antibodies label the plasma membrane of 30% of the cells, reflecting transfec- tion efficiency. Under non-permeabilizing conditions, the few labeled cells also displayed a lack of plasma membrane integrity. These data suggest that prestin's N-and C-termini are cytoplasmic. Furthermore, prestin staining in OHCs was observed only under permeabilizing conditions. These results implicate prestin's N- and C-termini as portions that may interact with other cytoplasmic proteins. A model of prestin membrane topology is also considered based on the results.

Inhibition of angiogenesis by adenovirus-mediated sFlt-1 expression in a rat model of corneal neovascularization

Pathological angiogenesis, or the production of new capillary vessels from preexisting vasculature, within the eye is a serious event that often leads to blindness. Upregulation of vascular endothelial growth factor (VEGF) has been linked to neovascularization in the eye, suggesting that it could be a suitable target to inhibit angiogenic changes. This work investigated whether the presence of a proven antiangiogenic factor, the soluble variant of the VEGF receptor, sFlt-1, in the anterior chamber is sufficient to inhibit new vessel formation in the cornea in an animal model of corneal neovascularization. A recombinant adenovirus vector that can mediate efficient in vivo gene transfer and expression in ocular cells was selected as a delivery agent. We have shown that after the injection of Ad.betagal into the anterior chamber of normal and cauterized rat eyes, corneal endothelial cells and cells of the trabecular meshwork were efficiently transduced and that beta-galactosidase (beta-Gal) expression was maintained up to 10 days postinjection. Cauterization significantly increased the amount of immunoreactive VEGF in vehicle- or Ad.null-injected animals (t test, p < 0.001 and p < 0.001, respectively). However, when cauterization was combined with Ad.sflt injection there was no statistically significant increase in the amount of immunoreactive VEGF (p = 0.12). The injection of Ad.sflt into the anterior chamber slowed or inhibited VEGF-induced angiogenic changes. After cauterization, 100% of uninjected and vehicle-injected and 82% of Ad.null-injected animals developed moderate to severe corneal angiogenesis in contrast to 18% of Ad.sflt-injected animals. These in vivo results suggest that the transient presence of antiangiogenic agents in the anterior chamber can be successfully used to inhibit the development of corneal angiogenesis.

In vivo use of oligonucleotides to inhibit choroidal neovascularisation in the eye

BACKGROUND

We have previously demonstrated the in vivo uptake of oligonucleotides in the rat eye and have continued with experiments to look at the effectiveness of targeted oligonucleotide sequences. Vascular endothelial growth factor (VEGF) is correlated with new blood vessel formation and has been implicated in numerous eye diseases characterised by abnormal blood vessel proliferation. An oligonucleotide targeted to the VEGF sequence was examined for its effect on VEGF production in vitro and the development of choroidal neovascularisation in vivo in the eye.

METHODS

A series of sequences were assessed in an in vitro screening system using retinal pigment epithelial (RPE) cells to demonstrate a reduction in VEGF. A targeted sequence was further investigated using an animal model of choroidal neovascularisation where a krypton laser was used to produce a wound healing response in the choroid and retina. The oligonucleotide was injected into the vitreous and the development of choroidal neovascularisation assessed using fluorescein angiography.

RESULTS

The targeted sequence was shown in vitro to downregulate the VEGF produced by RPE cells grown under hypoxic conditions and when injected into laser treated eyes was shown to be preferentially taken up in the laser lesion. Fluorescein angiography demonstrated that the test oligonucleotide was successful in reducing laser-mediated choroidal neovascularisation.

CONCLUSIONS

A sequence corresponding to the 5'UTR of the VEGF gene has provided encouraging results for the treatment of neovascularisation.

Relationship between age and effect of early and long-term captopril treatment in patients with acute myocardial infarction

OBJECTIVE

To analyse the relationship between age and treatment with captopril after acute myocardial infarction (AMI).

METHODS

In a randomized trial, 822 patients with a first AMI received conventional medical treatment, including intravenous thrombolytic therapy and oral aspirin or metoprolol, and then were randomly allocated to captopril [dosage from the first 6.25 mg to 25 mg/t.i.d, 209 younger patients (< or = 64 years), 269 elderly patients (65-75 years)] or conventional treatment only (131 younger patients, 213 elderly). Survival in the four groups was calculated with the Kaplan-Meier method. Multivariate analysis was performed to understand the degree that multi-variables (including age) affect survival in patients taking captopril in the hospital or during long term follow-up.

RESULTS

The survival of patients who took captopril correlated significantly with age (P < 0.001). The survival of the elderly patients on captopril treatment did increase (P < 0.0001), but not of the younger ones (P > 0.05) during hospitalization. During follow-up, the survival of patients who took captopril correlated insignificantly with age (P > 0.05), but both the elderly and the younger patients have good survival rates (all P < 0.01) and lower cardiac events (all P < 0.01) when they took captopril.

CONCLUSIONS

Captopril exerts a weak effect on the younger patients but a beneficial effect on the elderly patients during hospitalization after AMI. However, there is no difference between the younger and the elderly in the prognosis, both having good survival and lower cardiac events when they take captopril long term during follow-up.

Combined effect of cyclosporine and sirolimus on improving the longevity of recombinant adenovirus-mediated transgene expression in the retina

OBJECTIVES

To reevaluate the longevity and intraocular safety of recombinant adenovirus (rAd)-mediated gene delivery after subretinal injection, and to prolong transgene expression through the combination of 2 synergistic immunosuppressants.

METHODS

An rAd vector carrying green fluorescent protein (GFP) gene was delivered subretinally in the rat eye. The GFP expression was monitored in real time by fundus fluorescent photography. Intraocular safety was examined by observation of changes of retinal pigmentation, cell infiltration in virus-contacted area, immunophenotyping for CD4(+) and CD8(+) cytotoxic T lymphocytes, and CD68(+) macrophages, histologic findings, and dark-adapted electroretinography. Two synergistic immunosuppressants, cyclosporine and sirolimus, were used alone or in combination to prolong transgene expression by temporary immunosuppression.

RESULTS

The GFP expression peaked on day 4, dramatically decreased on day 10, and was not detectable on day 14. The decreased GFP expression was coincident with cell infiltration in virus-contacted area. Immunostaining showed that the infiltrating cells were CD4(+) and CD8(+) cytotoxic T lymphocytes and CD68(+) macrophages. Clumped retinal pigmentation and decreased b wave of dark-adapted electroretinogram were observed at 3 to 4 weeks after injection. Histologic examination confirmed rAd-induced retinal degeneration. Transient immunosuppression by cyclosporine and sirolimus, either alone or in combination, improved transgene expression, with the combination being the most efficient. The combined immunosuppression attenuated but did not retard the rAd-induced retinal damage.

CONCLUSIONS

Transgene expression mediated by rAd after subretinal delivery is short-term and toxic to the retina. Combination of cyclosporine and sirolimus may act as an immunosuppressive adjunct to prolong rAd-mediated gene transfer.

CLINICAL RELEVANCE

The intraocular safety of rAd should be carefully considered before clinical trials are performed.

Desensitization of chemokine receptor CCR5 in dendritic cells at the early stage of differentiation by activation of formyl peptide receptors

Chemokine receptors are subjected to heterologous desensitization by activation of formyl peptide receptors. We investigated the cross-talk between formyl peptide receptors and the chemokine receptor CCR5 in human monocyte-differentiated immature dendritic cells (iDC). Monocytes cultured with GM-CSF and IL-4 for 4 days exhibit markers characteristic of iDC and maintain the expression of both formyl peptide receptors FPR and FPRL1, as well as CCR5. Pretreatment of iDC with W peptide (WKYMVm), a potent agonist for FPR and FPRL1 but with preference for FPRL1, resulted in down-regulation of CCR5 from the cell surface and reduced cell response to the CCR5 ligands through a PKC-dependent pathway. Furthermore, W peptide induced a PKC-dependent phosphorylation of CCR5 and inhibited infection of iDC by R5 HIV-1. Our results indicate that the expression and functions of CCR5 in iDC can be attenuated by W peptide, which activates formyl peptide receptors, and suggest an approach to the design of novel anti-HIV-1 agents.

[Clinical significance of differential display cDNA fragment MRG98.2 expression in hepatocellular carcinoma]

OBJECTIVE

To search for the gene related to hepatocellular carcinoma (HCC), and to study its potential significance in liver oncogenesis.

METHODS

The difference in mRNA expression among HCC, nontumorous liver tissue, and normal liver tissue was investigated by differential display technique. Ten hepatic tissues of hepatoma versus surrounding noncancerous liver tissues were examined with MRG98.2 as a probe in Dot blot analysis. Expression of vascular endothelial growth factor (VEGF) mRNA in above-mentioned samples was examined with reverse transcription-polymerease chain reaction (RT-PCR).

RESULTS

Differential display cDNA fragment MRG98.2 was isolated from hepatoma samples. Dot blot analysis showed that MRG98.2 was expressed in 7 cases of HCC samples (7/10) but only in 2 of the surrounding noncancerous hepatic tissues (2/10). The expression of VEGF mRNA was upregulated in 6/7 of HCC samples expressed MRG98.2.

CONCLUSIONS

MRG98.2 may be a gene related to HCC. Its expression in HCC correlates with VEGF mRNA. MRG98.2 expression is helpful in predicting a tendency toward invasion and metastasis of HCC or a poor prognosis.

[Application of computer image process to the research on the contact characteristics of subtalar joint]

With the use of computer image processing technology, a new method was proposed for studying the contact characteristics of the subtalar joint. The results showed the total subtalar articulation area was 9.52 +/- 0.40 cm2. On neutral position and under 600 N load, the contact area of the subtalar joint was 2.00 +/- 0.11 cm2. The contact area of the posterior articulation was significantly larger than that of the anterior and medial articulation (p < 0.01). The average contact pressure was 19.3 +/- 1.38 N, the force transmitted by the subtalar was 389.16 +/- 28.75 N, which accounted for about 64.86% of the applied shank load (600 N), and 69.39% of the force was transmitted by the posterior articulation. The posterior articulation plays an important role in the load. The fracture line of the calcaneus often appears in this area.

[Clinical study on treatment 82 cases of chronic primary glomerulopathy with deficiency of yin with damp-heat symptom with dan shao tang]

OBJECTIVE

To investigate the treatment effect of Dan Shao Tang on chronic primary glomerulopathy with deficiency of Yin with damp-heat symptom.

METHODS

132 cases of chronic glomerulopathy with deficiency of Yin with damp-heat symptom, which divided into two groups at random, the 82 cases which were the therapy group using Dan Shao Tang and west medicine, and the other 50 cases which treated only by west medicine. We observed the effect and indexes change including renal function, proteinuria, hematuria.

RESULTS

The effective rate of the therapy group is 90.24%, and the effective rate of the control group is 66% (P < 0.05), The therapy group is superior to the control group in improving renal function, decreasing proteinuria and hematuria in evidence(P < 0.05).

CONCLUSION

Dan Shao Tang is effective to treatment on chronic primary glomerulopathy with deficiency of Yin with damp-heat symptom.

Characterization of mouse Dach2, a homologue of Drosophila dachshund

The Drosophila genes eyeless, eyes absent, sine oculis and dachshund cooperate as components of a network to control retinal determination. Vertebrate homologues of these genes have been identified and implicated in the control of cell fate. We present the cloning and characterization of mouse Dach2, a homologue of dachshund. In situ hybridization studies demonstrate Dach2 expression in embryonic nervous tissues, sensory organs and limbs. This pattern is similar to mouse Dach1, suggesting a partially redundant role for these genes during development. In addition, we determine that Dach2 expression in the forebrain of Pax6 mutants and dermamyotome of Pax3 mutants is not detectably altered. Finally, genetic mapping experiments place mouse Dach2 on the X chromosome between Xist and Esx1. The identification of human DACH2 sequences at Xq21 suggests a possible role for this gene in Allan-Herndon syndrome, Miles-Carpenter syndrome, X-linked cleft palate and/or Megalocornea.

Endometrial response to raloxifene compared with placebo, cyclical hormone replacement therapy, and unopposed estrogen in postmenopausal women

OBJECTIVE

To determine the endometrial effects of raloxifene 60 mg/day in postmenopausal women as assessed by vaginal bleeding and endometrial thickness.

DESIGN

Data from 1157 postmenopausal women were analyzed from a database consisting of four independent, double-blind, randomized, placebo-controlled trials (range = 6-30 months duration), a 24-month open-label randomized, cyclical hormone replacement therapy (HRT)-controlled trial, and a 6-month double-blind, randomized, unopposed estrogen-controlled trial. Vaginal bleeding rate was derived from self-reported adverse events collected at least every 6 months. Endometrial thickness was measured by ultrasonography at regular intervals.

RESULTS

Raloxifene 60 mg/day was not significantly different from placebo with regard to the incidence of vaginal bleeding, the baseline-to-endpoint change in endometrial thickness, or the proportion of women experiencing an increase in endometrial thickness above baseline after either 12 or 24 months of therapy. Unexpected bleeding was reported significantly more frequently in the unopposed estrogen groups compared with the raloxifene group (raloxifene 60 mg/day, 0% versus estrogen, 50%; p = 0.002). A significantly greater baseline-to-endpoint increase in endometrial thickness was observed in both the HRT and estrogen groups compared with their respective raloxifene comparison group (raloxifene 60 mg/day, 0.01 +/- 2.0 mm versus HRT, 1.8 +/- 3.2; p < 0.001; raloxifene 60 mg/day, 1.1 +/- 1.7 mm versus estrogen, 7.8 +/- 3.8; p < 0.001). No cases of endometrial hyperplasia or cancer were diagnosed in the placebo or raloxifene 60 mg/day groups. Endometrial hyperplasia was diagnosed in one case in the HRT group and in two cases in the estrogen group.

CONCLUSION

Raloxifene 60 mg/day for up to 30 months is not associated with vaginal bleeding or increased endometrial thickness in postmenopausal women.

Effects of membrane potential and tension on prestin, the outer hair cell lateral membrane motor protein

1. Under whole-cell voltage clamp, the effects of initial voltage conditions and membrane tension on gating charge and voltage-dependent capacitance were studied in human embryonic kidney cells (TSA201 cell line) transiently transfected with the gene encoding the gerbil protein prestin. Conformational changes in this membrane-bound protein probably provide the molecular basis of the outer hair cell (OHC) voltage-driven mechanical activity, which spans the audio spectrum. 2. Boltzmann characteristics of the charge movement in transfected cells were similar to those reported for OHCs (Q(max) = 0.99 +/- 0.16 pC, z = 0.88 +/- 0.02; n = 5, means +/- S.E.M.). Unlike that of the adult OHC, the voltage at peak capacitance (V(pkcm)) was very negative (-74.7 +/- 3.8 mV). Linear capacitance in transfected cells was 43.7 +/- 13.8 pF and membrane resistance was 458 +/- 123 Mohms. 3. Voltage steps from the holding potential preceding the measurement of capacitance-voltage functions caused a time- and voltage-dependent shift in V(pkcm). For a prepulse to -150 mV, from a holding potential of 0 mV, V(pkcm) shifted 6.4 mV, and was fitted by a single exponential time constant of 45 ms. A higher resolution analysis of this time course was made by measuring the change in capacitance during a fixed voltage step and indicated a double exponential shift (tau(0) = 51.6 ms, tau(1) = 8.5 s) similar to that of the native gerbil OHC. 4. Membrane tension, delivered by increasing pipette pressure, caused a positive shift in V(pkcm). A maximal shift of 7.5 mV was obtained with 2 kPa of pressure. The effect was reversible. 5. Our results show that the sensitivity of prestin to initial voltage and membrane tension, though present, is less than that observed in adult OHCs. It remains possible that some other interacting molecular species within the lateral plasma membrane of the native OHC amplifies the effect of tension and prior voltage on prestin's activity.

Dach1 mutant mice bear no gross abnormalities in eye, limb, and brain development and exhibit postnatal lethality

Drosophila dachshund is necessary and sufficient for compound eye development and is required for normal leg and brain development. A mouse homologue of dachshund, Dach1, is expressed in the developing retina and limbs, suggesting functional conservation of this gene. We have generated a loss-of-function mutation in Dach1 that results in the abrogation of the wild-type RNA and protein expression pattern in embryos. Homozygous mutants survive to birth but exhibit postnatal lethality associated with a failure to suckle, cyanosis, and respiratory distress. The heart, lungs, kidneys, liver, and skeleton were examined to identify factors involved in postnatal lethality, but these organs appeared to be normal. In addition, blood chemistry tests failed to reveal differences that might explain the lethal phenotype. Gross examination and histological analyses of newborn eyes, limbs, and brains revealed no detectable abnormalities. Since Dach1 mutants die shortly after birth, it remains possible that Dach1 is required for postnatal development of these structures. Alternatively, an additional Dach homologue may functionally compensate for Dach1 loss of function.

The salt stress-inducible protein kinase gene, Esi47, from the salt-tolerant wheatgrass Lophopyrum elongatum is involved in plant hormone signaling

Protein kinases play a central role in signal transduction in all organisms and to study signal transduction in response to salt stress we have identified and characterized a gene encoding a protein kinase that is induced by salt stress and abscisic acid (ABA) in the salt-tolerant wild wheatgrass Lophopyrum elongatum (Host) A. Love. The product of the early salt stress-induced gene, Esi47, was found to belong to the "novel Arabidopsis protein kinase" group of plant serine/threonine protein kinases. Transient gene expression assays in barley aleurone tissue showed Esi47 to suppress the gibberellin induction of the barley low-pI alpha-amylase gene promoter, thus providing evidence for the role of this protein kinase gene in plant hormone signaling. Esi47 contains a small upstream open reading frame in the 5'-untranslated region of its transcript that is implicated in mediating the repression of the basal level of the gene expression and in regulating the ABA inducibility of the gene, as shown in the transient gene expression assay in maize callus. Three Arabidopsis homologs of Esi47 were identified, and different members of this clade of genes showed differential patterns of regulation by salt stress and ABA in Arabidopsis roots and leaves. At least one of the Arabidopsis homologs contains a small open reading frame in its 5'-untranslated region, indicating that the unusual regulatory mechanism identified in Esi47 may be widely conserved.

Intracoronary stent implantation under intracoronary ultrasound guidance with aspirin and ticlopidine therapy

OBJECTIVE

To observe the immediate angiographic and intravascular ultrasound (IVUS) results and their effects on one month clinical outcomes in forty-one patients who submitted to coronary stent deployment with IVUS guidance.

METHODS

All patients were allocated to coronary stent implantation with high inflation pressure. After good angiographic results (< 20% residual stenosis), all patients underwent IVUS and higher-pressure dilatation would be necessary if criteria for optimal coronary stent implantation were not met. The optimal criterion of IVUS for stent implantation was the ratio of intrastent lumen cross-sectional area to the average of the proximal and distal reference lumen cross-sectional areas > or = 80%. All patients had aspirin and ticlopidine therapy on the day of angioplasty and during the one month follow-up period.

RESULTS

Optimal criteria of IVUS were obtained without any further intrastent dilatation in twenty-five patients but intrastent higher-pressure dilatation was performed in fourteen patients whose ultrasound results did not reach the criteria. In these patients, we increased the minimal intrastent lumen area 25.7% (P < 0.05). Thirty-five patients (90%) had good minimal intrastent lumen area of IVUS. There were no deaths, myocardial infarction, acute stent thrombosis or need for revascularization during the study and the one month follow-up.

CONCLUSIONS

Intracoronary stent deployment under IVUS guidance, including combining aspirin and ticlopidine therapy, had beneficial ultrasound results and good clinical outcomes after one month follow-up.

A burgeoning family of biological mediators: chemokines and chemokine receptors

Chemokines are a superfamily of pro-inflammatory polypeptide cytokines that selectively attract and activate different cell types. Most of its members are small proteins that exhibit conserved cysteines in specific positions. Chemokines activate cells through their binding to shared or unique cell surface receptors which belong to the seven-transmembrane (STM), G-protein-coupled receptors (GPCRs). The large number of chemokines and chemokine receptors are indicative of the importance of these molecules in a variety of pathophysiological conditions.

Kinetics of hydroxyapatite precipitation at pH 10 to 11

The mechanism and kinetics of hydroxyapatite (HAP) precipitation from aqueous solution at the conditions of pH 10-11 and at calcium ion concentrations of more than 0.5 mol/l were investigated. The results show that the reaction undergoes the following process: transferring from octacalcium phosphate (OCP) to amorphous calcium phosphate (ACP) rapidly, and then from ACP to calcium-deficient hydroxyapatite (DAP) and HAP. DAP was the non-stoichiometric material that ACP converts to HAP. Reaction temperature greatly affects the reaction rate of the conversion from ACP to HAP. It takes about 24 h to form pure-phase HAP at 25 degrees C while it takes only 5 min at 60 degrees C. The temperature also has a great deal of influence on the particle size and morphology of precipitated hydroxyapatite. The reaction of transformation from ACP to DAP was second order and the activation energy was 95 kJ/mol (22.7 kCal/mol) and therefore it was inferred that the conversion reaction was a surface control process.

Amyloid (beta)42 activates a G-protein-coupled chemoattractant receptor, FPR-like-1

Amyloid beta (Abeta) is a major contributor to the pathogenesis of Alzheimer's disease (AD). Although Abeta has been reported to be directly neurotoxic, it also causes indirect neuronal damage by activating mononuclear phagocytes (microglia) that accumulate in and around senile plaques. In this study, we show that the 42 amino acid form of beta amyloid peptide, Abeta(42), is a chemotactic agonist for a seven-transmembrane, G-protein-coupled receptor named FPR-Like-1 (FPRL1), which is expressed on human mononuclear phagocytes. Moreover, FPRL1 is expressed at high levels by inflammatory cells infiltrating senile plaques in brain tissues from AD patients. Thus, FPRL1 may mediate inflammation seen in AD and is a potential target for developing therapeutic agents.

Multireceptor GABAergic regulation of synaptic communication in amphibian retina

The synaptic output of retinal bipolar cells was monitored by recording light-evoked EPSCs in ganglion cells. Application of (RS)-2-amino-3-(3-hydroxy-5-tert-butyl-4-isoxazolyl (ATPA), a selective agonist at kainate receptors, depolarized amacrine cells and reduced the light-evoked excitatory current (L-EPSC) in ganglion cells. ATPA had only a slight effect on the light responses of bipolar cells. Therefore, ATPA suppresses bipolar cell synaptic output to ganglion cells. ATPA reduced the transient L-EPSC, but had comparatively little effect on sustained L-EPSC, of ganglion cells. The transient ON L-EPSC was more suppressed than the transient OFF L-EPSC. Thus, ATPA preferentially suppressed transient output from bipolar cells.GABA receptor antagonists blocked the effect of ATPA. This indicates that ATPA stimulated an endogenous inhibitory feedback pathway that suppressed bipolar cell output.CGP55845 and CGP35348 reduced the ATPA-induced suppression of L-EPSCs in ganglion cells, signifying that part of the feedback pathway is mediated by metabotropic GABA receptors.(1,2,5,6-Tetrahydropyridine-4-yl)-methylphosphinic acid (TPMPA) and picrotoxin, GABAC receptor antagonists, reduced the ATPA effect. Picrotoxin was more effective than ATPA. However, picrotoxin blocked only a part of this GABAC effect, while imidazole-4-acetic acid (I4AA) blocked another segment of the effect. This indicates that two pharmacologically distinct GABAC receptors mediate feedback to bipolar cells. SR95531 produced a very small suppression of the ATPA effect. Thus, GABAA receptors provide a negligible component to this feedback pathway. The experiments indicate that endogenous GABAergic feedback to bipolar cells suppresses their output, and that this feedback is mediated by at least three types of GABA receptor, both metabotropic and ionotropic.In conjunction with previous studies, the results indicate that feedback inhibition is the predominant factor regulating transient signalling in ganglion cells, while feedforward inhibition is the primary regulator of tonic ganglion cell signals.

Optimal timing of coronary stenting in unstable angina patients

OBJECTIVE

To assess the efficacy and safety of intracoronary stenting in the acute phase of unstable angina pectoris (UAP).

METHODS

Fifty-five patients with UAP were randomized to early (Group I, n = 29) and delayed interventional treatment (Group II, n = 26). Coronary angiography and stenting were performed within 48 hours in Group I and 7-10 days later in Group II. Procedural success rate, time interval from admission to angina relief and duration of hospitalization were recorded. Cardiac events within 30 days were observed as well.

RESULTS

Clinical characteristics and angiographic features were similar between the two groups. There was no significant difference in the procedural success rate (93% versus 96%), but the cardiac event rate within 30 days was significantly lower in Group I than in Group II (0% versus 9.2%, P < 0.05). The time interval from admission to angina relief (4.4 +/- 3.1 days versus 5.7 +/- 2.9 days) and the duration of hospitalization (8.8 +/- 3.2 days versus 13.5 +/- 3.1 days) were significantly reduced in Group I (both P < 0.05).

CONCLUSIONS

Intracoronary stent implantation is effective and safe in the acute phase of UAP. Early percutaneous coronary intervention results in rapid improvement in symptomatology and a shorter hospitalization. Its long-term effect has to be confirmed in a future randomized study.

Clinical observation on the long-term therapeutic effects of traditional Chinese medicine for treatment of liver fibrosis

48 patients with liver fibrosis due to hepatitis B were treated for 2 years with the drugs for tonifying the kidney, supplementing qi, cooling and invigorating the blood and detoxification. The symptoms were markedly improved, and serum ALT and bilirubin were recovered and kept normal in most of the cases. The mean levels of serum hyaluronic acid, procollagen peptide III and circulating immune complex were decreased and returned to normal after the treatment. B-ultrasonography showed that the portal vein kept in normal size in 82% of the patients, the enlarged portal vein diminished in diameter, and the enlarged spleen reduced.

Dysregulation of apoptosis: a possible mechanism leading to chronic progressive renal histological changes in lupus nephritis

OBJECTIVE

To evaluate apoptosis in lupus nephritis and the relationship between the existence of apoptotic cells in renal tissue and histopathological or clinical changes.

METHODS

Apoptosis was detected by in situ nick-end labeling techniques (TUNEL) in renal biopsies from 25 patients with type IV lupus nephritis (LN), 12 patients with IgA nephropathy IgAN, 4 patients with idiopathic mesangioproliferative glomerulonephritis (MsPGN) and 3 patients with acute poststreptococcal glomerulonephritis (APGN). Normal renal tissue obtained at nephrectomy for hypernephroma in 4 adults was used as control. Proliferating cells were identified by proliferating cell nuclear antigen (PCNA) in these patients.

RESULTS

Compared to other proliferative glomerulonephritis and controls, the patients with lupus nephritis had less apoptotic cells, a higher ratio of PCNA + cells/TdT + cells (P/T) in renal tissues; and their P/T ratio in glomeruli and tubulointerstitium correlated with the chronicity index, r = 0.4983 (P = 0.0132), r = 0.8399 (P < 0.001), r = 0.6614 (P = 0.0033), respectively. P/T ratios in the glomerulus and tubule had a positive correlation with 24-hour urinary protein, r = 0.8554 (P < 0.001) and r = 0.7134 (P = 0.001); and a negative correlation with creatinine clearance (Ccr), r = -0.4880 (P = 0.0133) and r = -0.7229 (P = 0.001), which in tubules positively correlated with serum creatinine (Scr), r = 0.4107 (P = 0.0414).

CONCLUSIONS

Apoptosis is reduced in proliferative lupus nephritis. Intense proliferation without a commensurate increase in apoptosis is a possible mechanism that leads to chronic progressive renal histopathological changes.

Characterization of chenodeoxycholic acid as an endogenous antagonist of the G-coupled formyl peptide receptors

OBJECTIVE AND DESIGN

To demonstrate the role of bile acids in immune modulation we examined the ability of select bile acids to inhibit leukocyte migration and chemoattractant receptor function.

MATERIALS

To elucidate this mechanism, we employed primary human monocytes, neutrophils and cell lines transfected to express either the high affinity fMLP receptor (FPR) or the low affinity fMLP receptor like 1 (FPRL1).

TREATMENT

Cells were treated with chenodeoxycholic acid (CDCA) and related bile acids in a 0-400 micromolar range.

METHOD

Cell viability, chemotaxis and calcium flux analysis were preformed.

RESULTS

We observed that pathophysiological levels (< or = 150 micromolar) of CDCA competitively inhibited 3H-fMLP binding to human monocytes, FPR and FPRL1 transfected cells. Additionally, CDCA reduced both the chemotactic and calcium flux responses induced by fMLP or "W" peptide. Further, CDCA inhibited anti-FPR antibody binding to monocytes.

CONCLUSIONS

CDCA selectively inhibited human leukocyte chemotaxis and calcium flux induced by fMLP, but not other chemoattractants, suggesting a mechanism for inhibition of inflammation and suppression of innate immune response.

Expression of functional formyl peptide receptors by human astrocytoma cell lines

Activation of astrocytes is important in the pathogenesis of a variety of diseases in the central nervous system, such as infection and neurodegeneration. We found that the bacterial chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine (fMLF) induced potent migration and Ca(2+) mobilization in human astrocytoma cell lines. The effect of fMLF was pertussis toxin-sensitive, suggesting the involvement of seven transmembrane, G protein-coupled receptor(s) for fMLF. Scatchard analyses revealed that astrocytoma cell lines express both high- and low-affinity binding sites for [3H]fMLF. RT-PCR confirmed the expression of transcripts of fMLF receptors, the high-affinity FPR and the low-affinity FPRL1 by these cells. Both fMLF and F peptide, a synthetic peptide domain of HIV-1 envelope protein which specifically activates FPRL1, increased secretion of IL-6 by astrocytoma cells. Our study demonstrates for the first time that FPR and FPRL1 expressed by astrocytoma cell lines are functional, and suggests a molecular basis for the involvement of these receptors in host defense in the brain.