A comparative dosimetric study on tangential photon beams, intensity-modulated radiation therapy (IMRT) and modulated electron radiotherapy (MERT) for breast cancer treatment

Recently, energy- and intensity-modulated electron radiotherapy (MERT) has garnered a growing interest for the treatment of superficial targets. In this work. we carried out a comparative dosimetry study to evaluate MERT, photon beam intensity-modulated radiation therapy (IMRT) and conventional tangential photon beams for the treatment of breast cancer. A Monte Carlo based treatment planning system has been investigated, which consists of a set of software tools to perform accurate dose calculation, treatment optimization, leaf sequencing and plan analysis. We have compared breast treatment plans generated using this home-grown treatment optimization and dose calculation software forthese treatment techniques. The MERT plans were planned with up to two gantry angles and four nominal energies (6, 9, 12 and 16 MeV). The tangential photon treatment plans were planned with 6 MV wedged photon beams. The IMRT plans were planned using both multiple-gantry 6 MV photon beams or two 6 MV tangential beams. Our results show that tangential IMRT can reduce the dose to the lung, heart and contralateral breast compared to conventional tangential wedged beams (up to 50% reduction in high dose volume or 5 Gy in the maximum dose). MERT can reduce the maximum dose to the lung by up to 20 Gy and to the heart by up to 35 Gy compared to conventional tangential wedged beams. Multiple beam angle IMRT can significantly reduce the maximum dose to the lung and heart (up to 20 Gy) but it induces low and medium doses to a large volume of normal tissues including lung, heart and contralateral breast. It is concluded that MERT has superior capabilities to achieve dose conformity both laterally and in the depth direction, which will be well suited for treating superficial targets such as breast cancer.

A quality assurance phantom for IMRT dose verification

This paper investigates a quality assurance (QA) phantom specially designed to verify the accuracy of dose distributions and monitor units (MU) calculated by clinical treatment planning optimization systems and by the Monte Carlo method for intensity-modulated radiotherapy (IMRT). The QA phantom is a PMMA cylinder of 30 cm diameter and 40 cm length with various bone and lung inserts. A procedure (and formalism) has been developed to measure the absolute dose to water in the PMMA phantom. Another cylindrical phantom of the same dimensions, but made of water, was used to confirm the results obtained with the PMMA phantom. The PMMA phantom was irradiated by 4, 6 and 15 MV photon beams and the dose was measured using an ionization chamber and compared to the results calculated by a commercial inverse planning system (CORVUS, NOMOS, Sewickley, PA) and by the Monte Carlo method. The results show that the dose distributions calculated by both CORVUS and Monte Carlo agreed to within 2% of dose maximum with measured results in the uniform PMMA phantom for both open and intensity-modulated fields. Similar agreement was obtained between Monte Carlo calculations and measured results with the bone and lung heterogeneity inside the PMMA phantom while the CORVUS results were 4% different. The QA phantom has been integrated as a routine QA procedure for the patient's IMRT dose verification at Stanford since 1999.

D-lactic acidosis secondary to short bowel syndrome

A 12 year old boy presented with 11 episodes of weakness, ataxia, nausea, slurred speech, dehydration, and sometimes severe lethargy bordering on coma. A year previously the boy had small intestinal resections leaving 20 cm of small bowel remaining. D-lactic acidosis was diagnosed on the basis of a D-lactate level of 5.23 mmol/l. The clinical presentation of the disease is recurrent episodes of unusual neurological manifestations and severe metabolic acidosis. The diagnosis is dependent on the presentations and the plasma D-lactate level. Development of the syndrome seems to be the effect of the accumulation of D-lactic acid.

Particle in cell simulation of laser-accelerated proton beams for radiation therapy

In this article we present the results of particle in cell (PIC) simulations of laser plasma interaction for proton acceleration for radiation therapy treatments. We show that under optimal interaction conditions protons can be accelerated up to relativistic energies of 300 MeV by a petawatt laser field. The proton acceleration is due to the dragging Coulomb force arising from charge separation induced by the ponderomotive pressure (light pressure) of high-intensity laser. The proton energy and phase space distribution functions obtained from the PIC simulations are used in the calculations of dose distributions using the GEANT Monte Carlo simulation code. Because of the broad energy and angular spectra of the protons, a compact particle selection and beam collimation system will be needed to generate small beams of polyenergetic protons for intensity modulated proton therapy.

Aged endothelial nitric oxide synthase knockout mice exhibit higher mortality concomitant with impaired open-field habituation and alterations in forebrain neurotransmitter levels

Endothelial nitric oxide synthase (eNOS) has been implicated in various brain and peripheral pathologies such as renal failure, heart failure or stroke. Consequently, the mortality rate of aged eNOS knockout mice (eNOS-/-) was higher than that of age-matched (18-22 months old) controls. Only seven of the original 14 eNOS-/- animals that participated in the study reached the age of 18 months or older, whereas no control mice died during this life span. In order to assess the behavioral and neurochemical consequences of chronic eNOS deficiency we examined whether the surviving aged eNOS-/- mice showed changes in terms of motor, emotional, exploratory and neurochemical parameters. Aged eNOS-/- mice showed reduced exploratory activity in the open-field with no habituation observable neither within sessions nor after repeated exposures. Pole test performance of eNOS-/- mice was comparable to controls. In the elevated plus-maze eNOS-/- mice did not differ from controls in terms of time spent in and entries into arms, but showed less locomotion on the open arms. The most prominent neurochemical alterations in the forebrains of aged eNOS-/- mice were: (a) increased acetylcholine levels in the neostriatum; (b) decreased noradrenaline concentrations in the ventral striatum; and (c) lower serotonin levels in the frontal cortex and ventral striatum. The present findings suggest that mice which survived chronic eNOS-deficiency into old age, show some behavioral and neurochemical phenotypes distinct from adult eNOS-/- mice.

Preparation and identification of specific and high-affinity monoclonal antibodies against morphine

A C6-hemisuccinate derivative of morphine was prepared and conjugated to bovine serum albumin and ovalbumin. High titer antibody producing spleen cells were removed and fused with myeloma cells of SP2/0 origin. Using a conventional immunization protocol generated twenty-six stable murine monoclonal antibodies (MAbs) producing cell lines to morphine. The donor mouse produced antiserum with a high titer of 1/640,000. Twelve MAbs were selected for further characterization since they showed high sensitivities (53 pg/well to inhibit 50% of the tracer) in improved group-selective immunoassay (IGSI). The assay, which maintains high sensitivity, high precision, and a wide range of optical density (OD) values, was developed using the conjugate M-6-S-OVA to screen and characterize the anti-morphine MAbs. After four successive limiting dilutions, antibodies produced by 12 clones had high affinities ranging from 10(9) to 10(10) M(-1). These clones were found to be of Ig(G) class and IgM class with kappa and lambda light chain. Subclass determination showed that the clones produced IgG1, IgG2a, IgG3, and IgM types of antibody. One clone (2F8B11F2A12) was used to establish the calibration curve with a sensitivity of 400 pg/mL covering up to 25.6 ng/mL in urine.

A Monte Carlo dose calculation tool for radiotherapy treatment planning

A Monte Carlo user code, MCDOSE, has been developed for radiotherapy treatment planning (RTP) dose calculations. MCDOSE is designed as a dose calculation module suitable for adaptation to host RTP systems. MCDOSE can be used for both conventional photon/electron beam calculation and intensity modulated radiotherapy (IMRT) treatment planning. MCDOSE uses a multiple-source model to reconstruct the treatment beam phase space. Based on Monte Carlo simulated or measured beam data acquired during commissioning, source-model parameters are adjusted through an automated procedure. Beam modifiers such as jaws, physical and dynamic wedges, compensators, blocks, electron cut-outs and bolus are simulated by MCDOSE together with a 3D rectilinear patient geometry model built from CT data. Dose distributions calculated using MCDOSE agreed well with those calculated by the EGS4/DOSXYZ code using different beam set-ups and beam modifiers. Heterogeneity correction factors for layered-lung or layered-bone phantoms as calculated by both codes were consistent with measured data to within 1%. The effect of energy cut-offs for particle transport was investigated. Variance reduction techniques were implemented in MCDOSE to achieve a speedup factor of 10-30 compared to DOSXYZ.

Allozyme polymorphisms of maize populations from southwestern China

Maize ( Zea mays L.) is one of the most-important food crops in southwestern China. The diversity of maize populations from southwestern China has been evaluated on the basis of agronomic and morphological data, but not on marker data. Our objectives were to evaluate the allozyme polymorphism of these populations, and group the populations on the basis of allozyme data. We analyzed 27 maize populations from southwestern China and two populations [BS13(S)C2 and Lancaster] from the USA for genetic variation at 18 allozyme loci. We found a total of 69 alleles at 18 allozyme loci with an average of 3.8 alleles per locus. Compared with inbreds, hybrids, and populations from the U.S. Corn Belt, the 27 Chinese populations had a significantly higher ( p<0.01) number of allozyme alleles per locus. Maize populations from southwestern China have accumulated abundant genetic diversity, and might be valuable germplasm for broadening the genetic base of U.S. Corn Belt breeding germplasm. The analyses of allele-frequency distributions and the expected heterozygosity also reflected the differences between the Chinese and the U.S. germplasm. The Chinese populations might be valuable germplasm for complementing U.S. Corn Belt breeding germplasm. The analysis of gene diversity showed that 77% of the allozyme variation resided within populations and 23% between populations. This result suggested that breeders should identify one or a few Chinese populations with the best agronomic performance, and exploit the genetic variation within these selected populations. Cluster analysis classified the 29 populations into four main groups. Groupings based on allozyme data could be useful for classifying the populations into different heterotic groups and, consequently, exploiting them in hybrid breeding.

Verification of IMRT dose distributions using a water beam imaging system

A water beam imaging system (WBIS) has been developed and used to verify dose distributions for intensity modulated radiotherapy using dynamic multileaf collimator. This system consisted of a water container, a scintillator screen, a charge-coupled device camera, and a portable personal computer. The scintillation image was captured by the camera. The pixel value in this image indicated the dose value in the scintillation screen. Images of radiation fields of known spatial distributions were used to calibrate the device. The verification was performed by comparing the image acquired from the measurement with a dose distribution from the IMRT plan. Because of light scattering in the scintillator screen, the image was blurred. A correction for this was developed by recognizing that the blur function could be fitted to a multiple Gaussian. The blur function was computed using the measured image of a 10 cm x 10 cm x-ray beam and the result of the dose distribution calculated using the Monte Carlo method. Based on the blur function derived using this method, an iterative reconstruction algorithm was applied to recover the dose distribution for an IMRT plan from the measured WBIS image. The reconstructed dose distribution was compared with Monte Carlo simulation result. Reasonable agreement was obtained from the comparison. The proposed approach makes it possible to carry out a real-time comparison of the dose distribution in a transverse plane between the measurement and the reference when we do an IMRT dose verification.

Improved method for determination of abamectin and ivermectin in cattle plasma

A liquid chromatographic (LC) method was developed for determination of abamectin (ABM) and ivermectin (IVM) in cattle plasma. The sample was extracted with acetonitrile and cleaned up on an alumina column. After conversion to stable fluorescent derivative with trifluoroacetic anhydride and N-methylimidazole, the sample was analyzed by LC with fluorescence detection (Ex 365 nm and Em 475 nm). Doramectin was used as an internal standard. Recoveries ranged from 91.2 to 100.7% for IVM and from 87.0 to 98.7% for ABM, with 1-50 ng/mL fortified samples. The coefficients of variation were <10.1%. The limit of detection was 0.02 ng/mL for ABM and IVM in 1.0 mL samples.

Resolution of the essential constituents of Ramulus cinnamomi by an evolving chemometric approach

The analysis of complex mixtures, such as those of traditional Chinese medicine (TCM), is difficult by conventional methods of analysis. Chemometric methods provide a new way to solve such problems. Subwindow factor analysis (SFA) paired with the evolving window orthogonal projection (EWOP) method, has been used as a new evolving approach to the resolution of volatile components of Ramulus cinnamomi (RC). Compared with conventional chromatographic analysis, the chromatographic separation conditions necessary are greatly mitigated in our approach, yet the accuracy of qualitative and quantitative results is improved, because the measured data matrix has been resolved into chromatograms and mass spectra of the chemical components. Our method is, moreover, friendly to use and easy to program. Experimental results show the efficiency and convenience of the proposed approach. Forty-seven of the seventy-eight separated constituents in an essential oil, accounting for 89.55% of the sample, were identified by mass spectroscopy (MS).

Correlation between electrophysiology and morphology of three groups of neuron in the dorsal commissural nucleus of lumbosacral spinal cord of mature rats studied in vitro

The dorsal commissural nucleus (DCN) in the lumbosacral spinal cord receives afferent inputs from the pelvic organs via pudendal and pelvic nerves. Electrophysiological and morphological properties of neurons in the DCN of L6-S1 were examined using whole-cell recordings with biocytin-filled electrodes in transverse slices of mature rat spinal cord. Neurons were categorized into three groups according to their discharge in response to suprathreshold depolarizing pulses; neurons with tonic (19/42) and phasic (13/42) firing patterns, and neurons (10/42) that fired in bursts arising from a Ca(2+)-dependent hump. The predominantly fusiform somata of neurons labeled during recording (n = 31) had on average 3.1 primary dendrites, 7.5 terminating dendritic branches, 3.1 axon collaterals, and 14.2 axon terminations per neuron. The groups were morphologically distinct on the basis of their dendritic branching patterns. Phasic neurons (n = 10) had the most elaborate dendritic branching and the largest numbers of axon collaterals. All tonic neurons (n = 11) had axons/collaterals projecting to the intermediolateral area but none to the funiculi, suggesting that they function as interneurons in local autonomic reflexes. Many axons/collaterals of all phasic neurons lay within the DCN, suggesting that they integrate segmental and descending inputs. Seven of 10 neurons with Ca(2+)-dependent humps had axons/collaterals extending into one of the funiculi, suggesting that they project intersegmentally or to the brain. Ca(2+) hump neurons also had more axons/collaterals within the DCN and fewer in the intermediolateral area than tonic neurons. This correlation between firing pattern and morphology is an important step toward defining the cellular pathways regulating pelvic function.

Glutamine enhances the gut-trophic effect of growth hormone in rat after massive small bowel resection

Background. Bowel-specific nutrient, glutamine, growth hormone, and modified diet have been reported to jointly improve nutrient absorption in patients with short bowel syndrome. However, controversy exists about the exact treatment factor. In this study we attempted to analyze the individual and combined effect of glutamine supplementation and growth hormone on small bowel adaptation by using tube feeding to control luminal nutrition supply. Materials and methods. Thirty-two adult male Sprague-Dawley rats (278 +/- 8 g) underwent 85% mid-small bowel resection and were randomly assigned to four groups: Control, receiving control liquid diet via a gastrotomy tube; GLN, receiving liquid diet enriched with 20 g. L(-1) glutamine; GH, receiving subcutaneous growth hormone (GH) (0.3 IU, bid); and GLN + GH, receiving both glutamine supplementation and GH treatment. All animals were provided with isocaloric (60 kcal/day) and isonitrogenous (0.686 g/day) nutrition. Absorption tests were performed in the form of oral nutrient tests with (14)C-labeled glucose and (3)H-labeled palmitic acid on the Postoperative Day 12. Results. GH treatment significantly increased the plasma insulin-like growth factor I (IGF-I) level, body weight, jejunal and ileal villous height and mucosal thickness, and peak plasma (14)C and (3)H levels. Glutamine supplementation did not produce a significant difference; however, combined with GH treatment, glutamine supplementation further increased body weight, plasma IGF-I level, jejunal and ileal villous height and mucosal thickness, and peak plasma (14)C and (3)H levels significantly. Conclusions. After massive small bowel resection, enteral glutamine supplementation alone has no remarkable beneficial effect on bowel adaptation. However, glutamine supplementation enhanced the gut-trophic effect of GH.

[Research on DNA molecular marker of Magnolia officinalis Rehd. et Wils.--RAPD study on certified species]

AIM

To discuss the intraspecific relationship in Magnolia officinalis and the genuineness of Cortex Magnoliae officinalis, and to find some DNA characters of certified "Houpo".

METHODS

Thirty-three samples from eleven locations, which can represent most of the distribution of M. officinalis, were selected. The total DNA was extracted. Severty-four random primers were tried to get good amplification.

RESULTS

One hundred and sixteen bands amplified from seventeen primers, were clustered by NTSYS-pc software. Three branches were obtained. Some distinctive primers and bands, which represent certified species or fine breed, were obtained also.

CONCLUSION

1) M. officinalis should be divided into three geographic clans instead of two subspecies or varieties, they are, a) typical officinalis, b) typical biloba and c) Middle type. This conclusion agrees with the leaf form and other characters. 2) The genetic difference between "Chuanpo" and "Wenpo" is evident and the difference is in correspondence with the quantities of their chemical constituents. So, the genetic difference is the main reason of the genuineness of Cortex Magnoliae officinalis. 3) These results may be used to establish DNA database for identification of Cortex Magnoliae officinalis.

Distribution of double-negative (CD4- CD8-, DN) T subsets in blood and synovial fluid from patients with rheumatoid arthritis

Double-negative (CD4- CD8-) T (DNT) cells have been postulated to be potentially autoreactive. However, the role of DNT cells in rheumatoid arthritis (RA) has received limited attention. We investigated the distribution of DNT subsets in peripheral blood (PB) and synovial fluid (SF) from patients with active RA to determine whether these cells have relevance to RA. Two-colour flow cytometric analysis was performed to detect DNT cells in PB from 35 RA patients, 26 healthy controls and in SF aspirated from 19 inflamed rheumatoid joints. The subsets of DNT cells, i.e those expressing T cell receptor alphabeta (alphabeta DNT) or gammadelta (gammadelta DNT) were simultaneously examined. Our results showed that DNT cells constituted a very minor subset of PB lymphocytes. When expressed as a percentage of total lymphocytes, alphabeta DNT levels in normal individuals ranged from 0.27 to 2.08% (average 0.76%), while those of gammadelta DNT ranged from 1.02 to 11.42% (average 3.23%). Compared with normal individuals, RA patients had a similar distribution of alphabeta DNT cells in both PB and SF. However, RA patients had significantly lower levels of gammadelta DNT cells in PB than control subjects (1.38 +/- 1.08% vs 3.23 +/- 2.12%, p<0.05), while the levels of gammadelta DNT cells in SF of RA patients were higher than those in PB from RA patients and normal controls. The difference between PB and SF in RA was statistically significant (3.90 +/- 1.88% vs 1.38 +/- 1.08%, p<0.05). A higher level of gammadelta DNT in SF than their paired PB was consistently noted from nine available paired samples. Our findings suggest that gammadelta NT cells, but not alphabeta DNT cells, are probably relevant to RA. The lower percentage of circulating gammadelta DNT cells might have resulted from migration from the circulation into the synovium, suggesting a role for gammadelta DNT cells in the pathogenesis of rheumatoid synovitis.

Effect of bowel rehabilitative therapy on structural adaptation of remnant small intestine: animal experiment

AIM: To investigate the individual and the combined effects of glutamine, dietary fiber, and growth hormone on the structural adaptation of the remnant small bowel.

METHODS: Forty-two adult male Sprague-Dawley rats underwent 85% mid-small bowel resection and received total parenteral nutrition (TPN) support during the first three postoperational days. From the 4th postoperational day, animals were randomly assigned to receive 7 different treatments for 8 d: TPNcon group, receiving TPN and enteral 20 g·L^-1 glycine perfusion; TPN + Gln group, receiving TPN and enteral 20 g·L^-1 glutamine perfusion; ENcon group, receiving enteral nutrition (EN) fortified with 20 g·L^-1 glycine; EN + Gln group, enteral nutrition fortified with 20 g·L^-1 glutamine; EN + Fib group, enteral nutrition and 2 g·L^-1 oral soybean fiber; EN + GH group, enteral nutrition and subcutaneous growth hormone (GH) (0.3IU) injection twice daily; and ENint group, glutamine-enriched EN, oral soybean fiber, and subcutaneous GH injection.

RESULTS: Enteral glutamine perfusion during TPN increased the small intestinal villus height (jejunal villus height 250 µm ± 29 µm in TPNcon vs 330 µm ± 54 µm in TPN + Gln, ileal villus height 260 µm ± 28 µm in TPNcon vs 330 µm ± 22 µm in TPN + Gln, P < 0.05) and mucosa thickness (jejunal mucosa thickness 360 µm ± 32 µm in TPNcon vs 460 µm ± 65 µm in TPN +Gln, ileal mucosa thickness 400 µm ± 25 µm in TPNcon vs 490 µm ± 11 µm in TPN + Gln, P < 0.05) in comparison with the TPNcon group. Either fiber supplementation or GH administration improved body mass gain (end body weight 270 g ± 3.6 g in EN + Fib, 265.7 g ± 3.3 g in EN + GH, vs 257 g ± 3.3 g in ENcon, P < 0.05), elevated plasma insulin-like growth factor (IGF-I) level (880 µg·L^-1± 52 µg·L^-1 in EN + Fib, 1200 µg·L^-1± 96 µg·L^-1 in EN ± GH, vs 620 µg·L^-1± 43 µg·L^-1 in ENcon, P < 0.05), and increased the villus height (jejunum 560 µm ± 44 µm in EN ± Fib, 530 µm ± 30 µm in EN ± GH, vs 450 µm ± 44 µm in ENcon, ileum 400 µm ± 30 µm in EN + Fib, 380 µm ± 49 µm in EN ± GH, vs 320 µm ± 16 µm in ENcon, P < 0.05) and the mucosa thickness (jejunum 740 µm ± 66 µm in EN ± Fib, 705 µm ± 27 µm in ENGH, vs 608 µm ± 58 µm in ENcon, ileum 570 µm ± 27 µm in EN ± Fib, 560 µm ± 56 µm in EN ± GH, vs 480 µm ± 40 µm in ENcon, P < 0.05) in remnant jejunum and ileum. Glutamine-enriched EN produced little effect in body mass, plasma IGF-I level, and remnant small bowel mucosal structure. The ENint group had greater body mass (280 g ± 2.2 g), plasma IGF-I level (1450 µg·L^-1± 137 µg·L^-1), and villus height (jejunum 620 µm ± 56 µm, ileum 450 µm ± 31 µm) and mucosal thickness (jejunum 800 µm ± 52 µm, ileum 633 µm ± 33 µm) than those in ENcon, EN + Gln (jejunum villus height and mucosa thickness 450 µm ± 47 µm and 610 µm ± 63 µm, ileum villus height and mucosa thickness 330 µm ± 39 µm and 500 µm ± 52 µm), EN + GH groups (P < 0.05), and than those in EN + Fib group although no statistical significance was attained.

CONCLUSION: Both dietary fiber and GH when used separately can enhance the postresectional small bowel structural adaptation. Simultaneous use of these two gut-trophic factors can produce synergistic effects on small bowel structural adaptation. Enteral glutamine perfusion is beneficial in preserving small bowel mucosal structure during TPN, but has little beneficial effect during EN.

Outer membrane protein-specific monoclonal antibodies protect SCID mice from fatal infection by the obligate intracellular bacterial pathogen Ehrlichia chaffeensis

Previous studies of Ehrlichia chaffeensis infection in the mouse have demonstrated that passive transfer of polyclonal Abs from resistant immunocompetent mice to susceptible SCID mice ameliorated infection and disease, even when Abs were administered during established infection. To identify particular Abs that could mediate bacterial clearance in vivo, E. chaffeensis-specific mAbs were generated and administered to infected SCID mice. Bacterial infection in the livers was significantly lowered after administration of either of two Abs of different isotypes (IgG2a and IgG3). Moreover, repeated administration of one Ab (Ec56.5; IgG2a) rescued mice from an otherwise lethal infection for at least 5 wk. Both protective Abs recognized the E. chaffeensis major outer membrane protein (OMP)-1g. Further studies revealed that both Abs recognized closely related epitopes within the amino terminus of the first hypervariable region of OMP-1g. Analyses of human sera showed that E. chaffeensis-infected patients also generated serological responses to OMP-1g hypervariable region 1, indicating that humans and mice recognize identical or closely related epitopes. These studies demonstrate that OMP-specific mAbs can mediate bacterial elimination in SCID mice, and indicate that Abs, in the absence of cell-mediated immunity, can play a significant role in host defense during infection by this obligate intracellular bacterium.

Viable rabbits derived from reconstructed oocytes by germinal vesicle transfer after intracytoplasmic sperm injection (ICSI)

Abnormal oocyte spindle due to the improper function of ooplasm is associated with female infertility of advanced maternal age. A possible way to overcome this problem is to transfer an oocyte germinal vesicle (GV) which contains genetic materials of a patient with a history of poor embryo development to the cytoplast from a donor oocyte. Here we demonstrate that GV transfer is feasible using a rabbit model. When the GVs were transferred to auto- or hetero-cytoplasts of GV stage oocytes, around 80% of the reconstructed oocytes could mature in vitro and 7.1-9.4% of the oocytes developed to blastocyst stage after intracytoplasmic sperm injection (ICSI). Transfer of 93 fertilized eggs reconstructed via GV transfer into six recipients resulted in two live offspring. Results of this experiment indicate that GV transfer can potentially become a new approach in treatment of infertility because of advanced maternal age.

Effects of nicotine and cotinine on porcine arterial endothelial cell function

BACKGROUND. There has been a significant amount of research on the effects of nicotine on vascular biology; however, little is known about the effects of cotinine, the metabolic product of nicotine. This study used a novel vascular perfusion system to study the effects of nicotine and cotinine on the vascular endothelial cell function.

METHODS

Porcine common carotid arteries were cultured in a novel vascular perfusion system with nicotine or cotinine or as controls. After 24 h, vessels were precontracted with norepinephrine and subsequently relaxed with acetylcholine. Vessel diameters were recorded and analyzed. After culture, samples were taken for en face, immunohistochemistry, and RT-PCR for eNOS. Porcine coronary arteries were incubated as controls or with nicotine or cotinine and tested on a myograph system to measure contraction and relaxation.

RESULTS

Porcine carotid arteries treated with nicotine and cotinine showed a 27.2% and a 41.2% reduction in endothelial-dependent relaxation, respectively, as compared to control vessels (P<0.05). Rings of coronary arteries treated with nicotine relaxed similarly to control rings while cotinine-treated rings failed to relax to endothelial-dependent stimulation. RT-PCR for eNOS mRNA showed a 23. 2 and a 24.1% reduction in eNOS expression for nicotine- and cotinine-treated vessels, respectively (P<0.01). Additionally, immunohistochemical staining for eNOS showed less dense staining on nicotine- and cotinine-treated vessels as compared to controls. En face preparations showed normal endothelial cell morphology in all groups, but cell density decreased slightly in vessels treated with nicotine and cotinine.

CONCLUSION

These results indicate that cotinine may have even more effect on the impairment of endothelial-dependent vasorelaxation than nicotine for the regulation of vessel tone in porcine carotid and coronary arteries.

Protective effect of gypenosides on DNA and RNA of rat neurons in cerebral ischemia-reperfusion injury

AIM

To observe the protective effect of gypenosides (GP) on the neurons of hippocampus, cerebral cortex, corpus striatum, and dentate gyrus in cerebral ischemia-reperfusion injury of rats.

METHODS

Modified 4-vessel occlusion (4-VO) method was used to establish the model of acute global ischemia. The acridine orange (AO) staining method was used to observe the DNA and RNA contents of cerebral ischemia-reperfusion injury model in the areas.

RESULTS

The fluorescent intensity (reflecting DNA and RNA contents) of the DNA and RNA in the areas of cerebral ischemia-reperfusion injury was markedly abated compared with the normal control group. In the group of ig GP (100 mg/kg) it was enhanced compared with the model group and was the same as the normal control group.

CONCLUSION

The injury of the DNA and RNA in the areas of ischemia-reperfusion model was decreased by GP.

Validation of a Monte Carlo dose calculation tool for radiotherapy treatment planning

A new EGS4/PRESTA Monte Carlo user code, MCDOSE, has been developed as a routine dose calculation tool for radiotherapy treatment planning. It is suitable for both conventional and intensity modulated radiation therapy. Two important features of MCDOSE are the inclusion of beam modifiers in the patient simulation and the implementation of several variance reduction techniques. Before this tool can be used reliably for clinical dose calculation, it must be properly validated. The validation for beam modifiers has been performed by comparing the dose distributions calculated by MCDOSE and the well-benchmarked EGS4 user codes BEAM and DOSXYZ. Various beam modifiers were simulated. Good agreement in the dose distributions was observed. The differences in electron cutout factors between the results of MCDOSE and measurements were within 2%. The accuracy of MCDOSE with various variance reduction techniques was tested by comparing the dose distributions in different inhomogeneous phantoms with those calculated by DOSXYZ without variance reduction. The agreement was within 1.0%. Our results demonstrate that MCDOSE is accurate and efficient for routine dose calculation in radiotherapy treatment planning, with or without beam modifiers.

Monte Carlo verification of IMRT dose distributions from a commercial treatment planning optimization system

The purpose of this work was to use Monte Carlo simulations to verify the accuracy of the dose distributions from a commercial treatment planning optimization system (Corvus, Nomos Corp., Sewickley, PA) for intensity-modulated radiotherapy (IMRT). A Monte Carlo treatment planning system has been implemented clinically to improve and verify the accuracy of radiotherapy dose calculations. Further modifications to the system were made to compute the dose in a patient for multiple fixed-gantry IMRT fields. The dose distributions in the experimental phantoms and in the patients were calculated and used to verify the optimized treatment plans generated by the Corvus system. The Monte Carlo calculated IMRT dose distributions agreed with the measurements to within 2% of the maximum dose for all the beam energies and field sizes for both the homogeneous and heterogeneous phantoms. The dose distributions predicted by the Corvus system, which employs a finite-size pencil beam (FSPB) algorithm, agreed with the Monte Carlo simulations and measurements to within 4% in a cylindrical water phantom with various hypothetical target shapes. Discrepancies of more than 5% (relative to the prescribed target dose) in the target region and over 20% in the critical structures were found in some IMRT patient calculations. The FSPB algorithm as implemented in the Corvus system is adequate for homogeneous phantoms (such as prostate) but may result in significant under or over-estimation of the dose in some cases involving heterogeneities such as the air-tissue, lung-tissue and tissue-bone interfaces.

Expression of GABA transporters on bullfrog retinal Müller cells

gamma-Aminobutyric acid (GABA) transporters (GATs) are involved in regulating GABAergic transmission through the high-affinity uptake and release of GABA. In the present work, the expression of different subtypes of GATs (GAT-1, GAT-2, and GAT-3) on Müller cells was investigated both immunocytochemically and electrophysiologically in the bullfrog retina. Double-labeling experiments of glial fibrillary acidic protein (GFAP), a specific marker for Müller cells, and GATs showed that the somata, major processes, endfeet, and even branchlets of almost all Müller cells strongly expressed GAT-1 on the membrane, whereas the main trunks and endfeet of about 80-90% Müller cells were moderately GAT-2 labeled. No GAT-3 immunoreactivity was observed in Müller cells. Meanwhile, using the whole-cell recording technique, GAT-mediated currents were recorded from Müller cells in the retinal slice preparation, and they were reversibly blocked by removal of extracellular Na(+) and spread more or less evenly over the surface of these cells. Furthermore, the GATs on the Müller cells were sensitive to both nipecotic acid and beta-alanine, GABA uptake blockers. Taken together, the complementary immunocytochemical and electrophysiological results suggest that bullfrog Müller cells express functional GAT-1 and GAT-2, which may regulate GABAergic transmission by either taking up or releasing GABA, or both.

Energy- and intensity-modulated electron beams for radiotherapy

This work investigates the feasibility of optimizing energy- and intensity-modulated electron beams for radiation therapy. A multileaf collimator (MLC) specially designed for modulated electron radiotherapy (MERT) was investigated both experimentally and by Monte Carlo simulations. An inverse-planning system based on Monte Carlo dose calculations was developed to optimize electron beam energy and intensity to achieve dose conformity for target volumes near the surface. The results showed that an MLC with 5 mm leaf widths could produce complex field shapes for MERT. Electron intra- and inter-leaf leakage had negligible effects on the dose distributions delivered with the MLC, even at shallow depths. Focused leaf ends reduced the electron scattering contributions to the dose compared with straight leaf ends. As anticipated, moving the MLC position toward the patient surface reduced the penumbra significantly. There were significant differences in the beamlet distributions calculated by an analytic 3-D pencil beam algorithm and the Monte Carlo method. The Monte Carlo calculated beamlet distributions were essential to the accuracy of the MERT dose distribution in cases involving large air gaps, oblique incidence and heterogeneous treatment targets (at the tissue-bone and bone-lung interfaces). To demonstrate the potential of MERT for target dose coverage and normal tissue sparing for treatment of superficial targets, treatment plans for a hypothetical treatment were compared using photon beams and MERT.

[A survey on botanical origins of drug Xue Lianhua produced in China]

OBJECTIVE

Based on an to investigation and identification of commercial samples to find out the original species and resources of Xue Lianhua.

METHOD

Botanical and macroscopical identification.

RESULT

The main original species of the plant are Saussurea involucrata, S. medusa, S. gossypiphora, S. polylada, S. laniceps, S. tridactyla, S. gnaphaloides, S. kingii, S. obvallata, S. tangutica, S. globosa, S. longifolia, Soroseris erysimoides, So. glomerata and So. umbrella.

CONCLUSION

The flower and stem of S. involucrata and S. polylada and the whole herb of S. medusa and S. gossypiphora are used as Xue Lianhua in most areas of China.

A spinal cord slice preparation for analyzing synaptic responses to stimulation of pelvic and pudendal nerves in mature rats

The dorsal commissural nucleus (DCN) in the lumbosacral spinal cord (L6-S1) receives primary afferent fibers from both pelvic and pudendal nerves in rats. However, the physiological and pharmacological properties of synaptic responses of the DCN neurons to stimulation of those nerves remain unclear. We have developed a longitudinal spinal cord (L6-S1) slice preparation from mature rats that retained both nerves attached. Blind whole-cell recordings were made from the DCN neurons in this preparation. In most neurons, mono- and/or poly-synaptic fast excitatory postsynaptic potentials (EPSPs) were evoked by electrical stimulation of either the pelvic or pudendal nerve. These EPSPs were mediated by activation of Abeta/Adelta and/or C fibers (conduction velocities, 0.5-17.3 m/s), and were abolished by CNQX. Fast EPSPs elicited by either pelvic or pudendal nerve stimulation were occasionally accompanied by bicuculline- and strychnine-sensitive IPSPs. In one-third of the neurons tested, mono- and/or poly-synaptic EPSPs were elicited by the stimulation of both the pelvic and pudendal nerves, indicating convergence of the visceral and somatic primary afferent inputs from the pelvic region onto the DCN neurons. The preparation is applicable to study the mechanism of the integration of the visceral and somatic inputs in the spinal cord.

5-HT potentiates GABA- and glycine-activated chloride currents on the same neurons in rat spinal cord

The electrophysiological and pharmacological properties of GABA- and glycine (Gly)-induced responses were investigated in neurons acutely dissociated from the rat sacral dorsal commissural nucleus (SDCN) using the nystatin perforated patch recording configuration under voltage-clamp conditions. At a holding potential of -40 mV, the currents evoked by GABA and Gly increased in a sigmoidal fashion with increasing agonist concentration. The reversal potentials of I(GABA)and I(Gly) were close to the Cl- equilibrium potential. Bicuculline (BIC) and strychnine (STR) suppressed I(GABA) and I(Gly) in a concentration-dependent manner, although they have different affinities for GABA and Gly. 5-HT potentiated both I(GABA) and I(Gly) via intracellular protein kinase C on the same neurons. The results indicated that the acutely dissociated SDCN neurons responded to both exogenous GABA and Gly, which activated GABA(A) and STR-sensitive Gly receptors, respectively, and 5-HT may produce spinal antinociception through postsynaptic potentiation of I(GABA) and I(Gly) when they are coreleased; GABA and Gly may act as cotransmitters implicated in the control of spinal nociceptive signal processing in the mammalian spinal cord.

[Study on early repair of destructive hand injury and reconstruction of hand function]

OBJECTIVE

To investigate a clinical method in repairing destructive hand injury and reconstructing hand function in early stage.

METHODS

From January 1990 to June 1999, composite tissue transplantation was used to repair destructive hand damage and reconstruct hand function with vascular anastomosis in emergency (33 cases) or subemergency (126 cases). For the radial damage, combined flaps with toes was used to treat cicatricial contracture of thumb-web space. Opposing function of thumb was reconstructed by combined transplantation of short extensor muscle of great toe, short extensor muscle of toes or short abductor muscle of great toe in the same time of freeing the second toe. For no or deficient anastomosing vessels in donor site, "Y"--shaped reversal vein, anterograde bridging, or branches bridging of host vessels were applied.

RESULTS

All of tissue transplantation were survived, including combined tissue transplantation in 51 cases, composite tissue transplantation in 4 cases, tissue transplantation after replantation of severed wrist and finger in 4 cases, there were no infection or necrosis in all cases, and hand function recovered well.

CONCLUSION

It is an ideal procedure to repair destructive hand injury and reconstruct hand function by combined or composite tissue transplantation with vascular anastomosis in emergency or subemergency.

Determination of sulfonamides in swine meat by immunoaffinity chromatography

A procedure was developed for the preparation of anti-sulfonamide (SA) group-specific antibodies and immunosorbents. Sulfonamide haptens and conjugates were synthesized by building spacer arms on an N1 group of 4-aminobenzensulfonamide. The anti-SA group-specific antibodies and immunosorbents were prepared successfully. After extraction with methanol-water (8 + 2), sulfamonomethoxine, sulfadimethoxine, and sulfaquinoxaline were cleaned up on immunoaffinity columns and determined by reversed-phase liquid chromatography with UV detection at 270 nm. The recoveries from fortified swine meat (10-100 microg/kg) ranged from 70.8 to 94.1%, with coefficients of variation of 3.4-12.9%. Limits of detection were 1-2 microg/kg.

Clinical auscultation skills in pediatric residents

OBJECTIVE

The aim of this study is to determine the level of clinical auscultation skills in pediatric residents at Duke University Medical Center.

METHODS

Forty-seven residents from pediatrics and joint medicine/pediatrics training programs at Duke University Medical Center were enrolled in this study. They were asked to examine the cardiovascular patient simulator, Harvey, and report their findings. Five common conditions seen in the pediatric population were presented: ventricular septal defect, atrial septal defect, pulmonary valve stenosis, combined aortic valve stenosis and insufficiency, and innocent systolic ejection murmur. The responses were scored by the number of features and diagnoses accurately reported. Five pediatric cardiologists and cardiologists in training were also asked to participate in a manner similar to the trainees.

RESULTS

The mean score of features identified for the resident group was 11.4 +/- 2.6 of a possible 19. The diagnostic accuracy was 33%. There was no significant difference between residents by year of training or by type of residency program, although there was a trend toward improved performance with more training. The difference in performance between the pediatric cardiology group and the residents group was striking. The condition that was most frequently misdiagnosed was the innocent systolic ejection murmur.

CONCLUSIONS

The clinical auscultation skills of pediatric residents in this study were suboptimal. There was a trend toward improvement as training progressed, although not statistically significant. These skills are likely to improve further with increased exposure to patients with cardiovascular disease especially in the ambulatory care setting.

Genuine saddle point and nucleation potential for binary systems

A generalized nucleation potential is constructed for binary systems. The potential consists of the reversible work of cluster formation plus additional terms arising from various kinetic effects. We show that the major nucleation flux passes through the saddle point (termed the genuine saddle point) of this generalized nucleation potential. The generalized nucleation potential reduces to the kinetic potential of a unary system when one component vanishes. The genuine saddle point concept provides a convenient way to identify systems and conditions for which the ridge crossing phenomenon occurs. Our theory agrees approximately with exact numerical results.

Lupin alkaloids from Chinese Maackia amurensis

Two new alkaloids were isolated together with 16 known lupin alkaloids from the leaves and stems of Chinese Maackia amurensis. Their structures were determined by spectroscopic methods to be (-)-6alpha-methoxylupanine and (-)-5alpha-(12-cytisinylmethyl)-6alpha-hydroxylupan ine and identified by comparison with synthetic samples. The structures of lupin alkaloids were also related to the geographical distributions of the Maackia plants.

Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis

Although the sensitivity and specificity of the Duke criteria for the diagnosis of infective endocarditis (IE) have been validated by investigators from Europe and the United States, several shortcomings of this schema remain. The Duke IE database contains records collected prospectively on >800 cases of definite and possible IE since 1984. Databases on echocardiograms and on patients with Staphylococcus aureus bacteremia at Duke University Medical Center are also maintained. Analyses of these databases, our experience with the Duke criteria in clinical practice, and analysis of the work of others have led us to propose the following modifications of the Duke schema. The category "possible IE" should be defined as having at least 1 major criterion and 1 minor criterion or 3 minor criteria. The minor criterion "echocardiogram consistent with IE but not meeting major criterion" should be eliminated, given the widespread use of transesophageal echocardiography (TEE). Bacteremia due to S. aureus should be considered a major criterion, regardless of whether the infection is nosocomially acquired or whether a removable source of infection is present. Positive Q-fever serology should be changed to a major criterion.

Real-time 3-dimensional echocardiography evaluation of congenital heart disease

We evaluated the ability of real-time 3-dimensional (RT3D) echocardiography to diagnose congenital heart defects and its potential for presenting structural abnormalities in novel views. Seventy-five patients with suspected congenital heart defects were examined with the use of RT3D echocardiography. Images were reviewed off-line as multiple slices of the raw data or as volume-rendered images by a blinded observer. Diagnoses made from blinded review of the RT3D images were compared with the clinical report of the 2D echocardiogram obtained at the same visit. Real-time 3D echocardiography identified all structural abnormalities except for small atrial septal defects in 2 patients and coronary artery anatomy in D-transposition of the great arteries. Less than 5 minutes were needed to acquire RT3D images in all cases, and sedation was never required. Unique region-oriented views obtained from the 3D data set can be acquired quickly and have the potential to enhance understanding of complex cardiac anatomy.

A new perfusion culture system used to study human vein

BACKGROUND

Cell culture studies, ring studies, and indirect physiologic studies are the predominant models used to study human vascular tissue. Such studies are limited in their capacity to permit physiologic single-factor changes or to provide the proper mechanical stress or extracellular matrix present in normal tissues. We present a newly devised organ culture system that addresses these issues and permits survival of intact segments of human vascular tissue in a perfused environment. Our experience culturing human saphenous vein with this system is detailed.

METHODS

Perfusion culture chambers were designed and constructed in our laboratory. Excess saphenous vein segments were collected from coronary artery bypass graft cases at our hospital and then mounted into our perfusion culture system for 0, 24, 48, 72, or 96 h. Vasomotor assays, hematoxylin and eosin staining, bromodeoxyuridine staining, and factor VIII staining were performed to assess tissue survival.

RESULTS

A total of 24 veins were cultured. Average vessel length was 5 cm. The vessels contracted and relaxed the following amounts: time 0 (6.7% contraction, 5.0% relaxation), 24 h (5.7%, 5.3%), 48 h (5.2%, 2.8%), 72 h (4.8%, 5.3%), 96 h (4.8%, 3.8%). Hematoxylin and eosin staining, bromodeoxyuridine staining, and factor VIII staining support the viability of the tissue segments.

CONCLUSION

A new perfusion organ culture system has been devised that permits survival of intact human venous tissue for periods up to 96 h. Studies that permit physiologic single-factor changes along with precise control of the hemodynamic environment are possible with this system.

CNS myelin and sertoli cell tight junction strands are absent in Osp/claudin-11 null mice

Oligodendrocyte-specific protein (OSP)/claudin-11 is a recently identified transmembrane protein found in CNS myelin and testis with unknown function. Herein we demonstrate that Osp null mice exhibit both neurological and reproductive deficits: CNS nerve conduction is slowed, hindlimb weakness is conspicuous, and males are sterile. Freeze fracture reveals that tight junction intramembranous strands are absent in CNS myelin and between Sertoli cells of mutant mice. Our results demonstrate that OSP is the mediator of parallel-array tight junction strands and distinguishes this protein from other intrinsic membrane proteins in tight junctions. These novel results provide direct evidence of the pivotal role of the claudin family in generating the paracellular physical barrier of tight junctions necessary for spermatogenesis and normal CNS function.

Calcium-binding protein-immunoreactive projection neurons in the caudal subnucleus of the spinal trigeminal nucleus of the rat

It has been reported that calcium-binding proteins are good markers for different sets of neurons in various brain regions. We examined expression of the main calcium-binding proteins in projection neurons in the rat medullary dorsal horn (MDH) by combining immunofluorescence histochemistry for calbindin D28k (CB), calretinin (CR) and parvalbumin (PV) with the retrograde tract-tracing method. A fluorescence tracer, tetramethylrhodamine-dextran amine (TMR-DA), was injected into the parabrachial, thalamic or hypothalamic region. After such injections, a number of PV-, CR-, and/or CB-immunoreactive MDH neurons were labeled retrogradely with TMR-DA. Triple-immunofluorescence histochemistry further revealed that a number of CB-, CR-, or PV-immunoreactive TMR-DA-labeled MDH neurons showed immunoreactivity for substance P receptor (NK1), and that they expressed immunoreactivity for c-fos protein in the rats which were injected with formalin into the lips. Thus, it was indicated that some of CB-, CR-, or PV-containing projection neurons in the MDH might be involved in the transmission of nociceptive stimuli.

Resistance artery mechanics, structure, and extracellular components in spontaneously hypertensive rats : effects of angiotensin receptor antagonism and converting enzyme inhibition

BACKGROUND

Altered vascular mechanics resulting from changes in collagen and integrins may influence resistance artery structure and function and, therefore, peripheral resistance and blood pressure in spontaneously hypertensive rats (SHR).

METHODS AND RESULTS

Effects of age, angiotensin-converting enzyme inhibition (fosinopril, 10 to 30 mg/kg per day), and AT(1)-receptor antagonism (irbesartan, 50 mg/kg per day) on vascular structure, mechanics, and composition were assessed in SHR. Systolic blood pressure was elevated in young SHR (130+/-2 mm Hg) compared with Wistar-Kyoto (WKY) rats (106+/-2 mm Hg). In adult SHR, the rise in systolic blood pressure (44+/-3 mm Hg) was blunted by fosinopril (18+/-1 mm Hg) and irbesartan (9+/-3 mm Hg). Lumen diameter of mesenteric resistance arteries was smaller and media/lumen ratio was greater in young and adult SHR versus WKY rats. Growth index was 24% in untreated adult SHR versus WKY rats; these values were -35% for fosinopril-treated and -29% for irbesartan-treated SHR versus untreated SHR. Isobaric wall stiffness was normal despite increased stiffness of wall components in adult SHR vessels. Irbesartan partially prevented stiffening of wall components in SHR. The collagen/elastin ratio was greater in adult SHR vessels (6.5+/-1.3) than in WKY (3.2+/-0.4) vessels. Expression of alpha(v)beta(3) and alpha(5)beta(1) integrins was increased in SHR aged 20 versus 6 weeks. Expression of alpha(5)beta(1) integrins was lower in young SHR, and alpha(v)beta(3) integrins were overexpressed in adult SHR versus WKY rats. Irbesartan and fosinopril attenuated differences in the collagen/elastin ratio and integrin expression.

CONCLUSIONS

Wall components of mesenteric resistance arteries stiffen with age in SHR. Interrupting the renin-angiotensin system has normalizing effects on integrin expression and composition, stiffness, and growth of the arterial wall.

In vivo study of AT(1) and AT(2) angiotensin receptors in apoptosis in rat blood vessels

In vitro experiments suggest that angiotensin II (Ang II) may cause growth via angiotensin type 1 (AT(1)) receptors and apoptosis via angiotensin type 2 (AT(2)) receptors. To answer the question of whether AT(1) or AT(2) receptor activation could induce apoptosis in the vasculature in vivo, Wistar rats were infused for 7 days with Ang II (120 ng. kg(-1). min(-1) subcutaneously) and treated with the AT(2) receptor antagonist PD 123319 (30 mg. kg(-1). d(-1) subcutaneously) or the AT(1) receptor antagonist losartan (10 mg. kg(-1). d(-1) orally). Apoptosis in thoracic aorta was quantified by radiolabeled DNA laddering and by terminal deoxynucleotide transferase-mediated dUTP nick end-labeling. The expression of p53, bax, bcl-2, and caspase-3, which play critical roles in apoptotic signaling, was examined by Western blot analysis. The mRNA expression of AT(1) and AT(2) receptors was determined by reverse transcription-polymerase chain reaction. The increase in systolic blood pressure and aortic growth induced by Ang II infusion was completely prevented by losartan alone or losartan given with PD 123319, whereas PD 123319 resulted in a greater increase in systolic blood pressure and aortic growth than Ang II alone. Radiolabeled DNA laddering showed that Ang II infusion+/-losartan or PD 123319 significantly increased apoptosis (147+/-8%, 178+/-20%, and 238+/-41%, respectively, P<0.05 compared with control). Expression of bax and active forms of caspase-3 was increased in the Ang II+PD 123319 group, whereas the expression of p53 and bcl-2 was not significantly different in all groups. The expression of AT(1) and AT(2) receptor mRNA was downregulated by losartan and PD 123319, respectively. Thus, when AT(1) or AT(2) receptors are stimulated in vivo, apoptosis is enhanced in the media of blood vessels. In the case of AT(1) receptor stimulation, this may occur secondary to vascular growth and modulate the latter. Both bax and caspase-3 participate in the pathways of apoptosis triggered by in vivo AT(1) receptor stimulation.

Modulation of glycine-activated chloride currents by substance P in rat sacral dorsal commissural neurons

The modulatory effect of substance P (SP) on strychnine-sensitive glycine (Gly) response was examined in neurons acutely dissociated from the rat sacral dorsal commissural nucleus (SDCN) using nystatin perforated patch recording configuration under voltage-clamp conditions. Application of SP potentiated 30 mumol/L Gly-activated chloride current (IGly) in a concentration-dependent manner over the range of 1 nmol/L to 1 mumol/L at a holding potential of -40 mV. SP neither changed the reversal potential of Gly response nor affected the affinity of Gly to its receptor. The SP potentiation effect could be blocked by spantide as well as a selective NK1 receptor antagonist, L-668, 169, but not by NK2 receptor antagonist, L-659, 877. The facilitatory action of SP on IGly could also be abolished by pretreatment with chelerythrine or KN-62 in different neurons, a finding suggesting that protein kinase C (PKC) or Ca2+/calmodulin-dependent protein kinase II (CaMK II) possibly contributes to an intracellular pathway of SP in the augmentation of IGly. The results imply that SP may suppress nociception in the spinal cord by potentiating Gly response.

R-dl-verapamil downmodulates multidrug resistance of KBv200 cells to vincristine and doxorubicin

AIM

To study the attenuation of multidrug resistance (MDR) by R-dl-verapamil (R-Ver) and the acute animal toxicity of R-Ver, and to compare these results of R-Ver with the results of dl-verapamil (Ver).

METHODS

Cytotoxicity was determined by tetrazolium (MTT) assay. Cellular accumulation of doxorubicin (Dox) was measured by fluorescence spectrophotometry. Acute animal toxicity was tested by i.p. drug administration in BALB/c mice.

RESULTS

R-Ver attenuated MDR of KBv200 cells to vincristine (VCR) and Dox. This attenuation ability was dose-related, and was also dependent on drug exposure time. R-Ver 1.25 mumol.L-1 increased the sensitivity of KBv200 cells to VCR (P < 0.01) with a 24-h period of drug exposure. R-Ver downmodulated MDR and increased cellular Dox accumulation of KBv200 cells as effectively as Ver, but possessed lower acute toxicity in BALB/c mice. While LD50 of Ver was 60 (49-73) mg.kg-1, LD50 of R-Ver was 166 (137-202) mg.kg-1.

CONCLUSION

R-Ver downmodulated the MDR to VCR and Dox at 1.25 mumol.L-1, and this effect on VCR can be realized with drug exposure duration of 24 h.

Increased expression of down-regulatory CTLA-4 molecule on T lymphocytes from rheumatoid synovial compartment

Since the CTLA-4 molecule expressed on activated T lymphocytes has recently been suggested to be an important negative regulator in autoimmune diseases, this study was undertaken to investigate the expression and function of CTLA-4 on synovial T cells from patients with rheumatoid arthritis. CTLA-4-expressing T cells were detected using a dual fluorescence flow cytometric method. Only a small percentage of peripheral blood T cells from patients with rheumatoid arthritis had detectable surface CTLA-4 expression (mean +/- SD, 1. 89 +/- 1.92%). However, the levels of CTLA-4-positive T cells was increased significantly in rheumatoid synovial fluids (5.44 +/- 4. 96%) and synovial membranes (28.76 +/- 14.30%). To explore the role of CTLA-4 molecule in the inflammation of rheumatoid joints, CTLA-4 was blocked with anti-CTLA-4 antibody to assess its effects on the production of tumour necrosis factor alpha and interleukin 1beta in synovial fluid mononuclear cell culture. The addition of anti-CTLA-4 antibody enhanced the production of tumour necrosis factor alpha and interleukin 1beta in a dose-dependent manner. The data suggest that the expression of CTLA-4 plays a down-regulatory role in rheumatoid articular inflammation. We thus concluded that CTLA-4 was up-regulated on synovial T cells from patients with RA, and the increased CTLA-4 expression might exert a down-regulation effect on tumour necrosis factor alpha and interleukin 1beta production.

Altered angiotensin II-induced small artery contraction during the development of hypertension in spontaneously hypertensive rats

This study assessed whether the angiotensin-II (Ang II)-induced contractile responsiveness of resistance arteries is altered during the development of hypertension in spontaneously hypertensive rats (SHR). Structural parameters and Ang II-stimulated contraction were determined in small mesenteric arteries from 6-week-old (phase of developing hypertension) and 21-week-old SHR (phase of established hypertension), compared with age-matched Wistar-Kyoto rats (WKY). To ascertain whether effects were specific for Ang II, contractile responses to another vasoactive agonist, vasopressin (AVP), were also determined. Systolic blood pressure was measured in conscious rats by the tail-cuff method. Segments of third-order mesenteric arteries (approximately 200 microm in diameter and 2 mm in length) were mounted in a pressurized system with the intraluminal pressure maintained at 45 mm Hg. Blood pressure was significantly increased in SHR (P < .001) and was higher in adult than in young SHR (P < .001). Ang II dose-dependently increased contraction, with responses significantly greater (P < .05) in SHR than in age-matched WKY. SHR, in the early phase of hypertension, exhibited significantly augmented contractile responses (Emax = 70 +/- 5%), compared with SHR with established hypertension (Emax = 33 +/- 5%). These effects were not generalized, as responses to AVP were not significantly different between young and adult SHR. Functional Ang II-elicited alterations were associated with structural modifications: 6-week-old SHR had smaller media to lumen ratio compared with 21-week-old SHR (8.1% +/- 0.17% v 10.6% +/- 0.20%, P < .01). In young SHR vessels the media cross-sectional area was unchanged relative to age-matched WKY rats, suggesting eutrophic remodeling (remodeling index 101.4% v 93.3% young v adult), whereas the cross-sectional area of adult vessels was increased in comparison to WKY rats, suggesting mild hypertrophic remodeling (growth index -1.0% v 15.2%, young v adult). In conclusion, the present study demonstrates that in SHR with early hypertension and slight medial thickening, Ang II-mediated vascular contractile responsiveness is significantly augmented compared with SHR with established hypertension and more severe vascular structural changes. These findings indicate attenuation, as hypertension progresses, of the initially enhanced vascular reactivity to Ang II that is present during the development of hypertension in SHR.

The distribution of substance P receptor (NK1)-like immunoreactive neurons in the newborn and adult human spinal cord

Substance P receptor (i.e. NK1)-like immunoreactive (SPR-LI) neurons were observed in the newborn and adult human spinal cord. Substance P receptor-like immunoreactive neuronal cell bodies were seen most frequently in lamina I, and were scattered throughout the remaining laminae of the dorsal horn and the area around the central canal. Some neurons in the intermediolateral nucleus also showed weak immunoreactivity. The pattern of distribution of SPR-LI neurons in the adult spinal cord was essentially the same as that in the newborn spinal cord. However, SPR-LI neurons cell bodies were seen much more frequently in the newborn than in the adult dorsal horn, especially in lamina II.

Enhanced learning by posttrial injection of H1-but not H2-histaminergic antagonists into the nucleus basalis magnocellularis region

The aim of this study was to examine the effects of histaminergic antagonists on memory upon injection into the region of the nucleus basalis magnocellularis (NBM). In experiment 1, rats with chronically implanted cannulae were trained on the uphill avoidance task, which involves a punishment of a high-probability turning response on a tilted platform (negative geotaxis). Immediately after the training trial, that is, after a tail shock was administered upon performing the response, rats received one microinjection (0.5 microliter) of H1-receptor blocker chlorpheniramine (dose range 0.1 to 20 microgram) or the H2-receptor blocker ranitidine (same dose range) or saline into the NBM region. When tested 24 h later, rats treated with chlorpheniramine (20 micrograms) had significantly longer uphill latencies than vehicle controls and ranitidine-treated animals, indicative of superior learning of the avoidance response. In experiment 2, a test for possible proactive effects of posttrial chlorpheniramine on performance during the retention trial was performed. Animals were injected with either 20 micrograms chlorpheniramine or saline immediately after the training trial of the uphill task. One chlorpheniramine control group was treated with a delay of 5 h. Additional groups which received chlorpheniramine or vehicle after the training trial but no trail shock were included. When tested 24 h later, rats injected with 20 micrograms chlorpheniramine again exhibited significantly longer uphill latencies than did vehicle-injected rats. Retention latencies for the rats of the chlorpheniramine 5-h delayed group did not differ from those of the vehicle-injected rats, ruling out proactive effects of chlorpheniramine on performance. In summary, the histaminergic H1-blocker chlorpheniramine can enhance mnemonic functioning in addition to its reinforcing effects upon NBM injection as reported previously.

Deterministic properties of apnoeas in an abdominal breathing signal

The paper describes a general set of properties that represent most apnoeas as found in an abdominal breathing signal. An apnoea is a pause in breathing during sleep, and only central apnoeas in infants are considered. Human experts are consulted to determine what properties of the signal they use to recognise apnoeas. A set of deterministic, or shape, properties is developed to represent expert opinion. An apnoea is modelled as a flat region with four properties: flatness, duration, thinness and smoothness. Mathematical descriptions of each property are formulated that discriminate between apnoea and non-apnoea events, and each description is tested for discrimination and independence. The average power of discrimination is 24% +/- 16% and the average correlation coefficient is 0.28 +/- 0.16. Applications include scoring apnoeas for sleep studies and developing standard definitions of apnoeas.

Functional properties of ionotropic glutamate receptor channels in rat sacral dorsal commissural neurons

Nystatin perforated patch and conventional whole-cell recording configurations were used to characterize the properties of ionotropic glutamate receptor (GluR) channels in neurons freshly dissociated from the rat sacral dorsal commissural nucleus (SDCN). L-Glutamate (Glu), N-methyl-D-aspartate (NMDA), quisqualate (QA), alpha-amino-3-hydroxy-5-methyl-4-isoxazoleprop ionate (AMPA) and kainate (KA) applied via a Y-tube produced inward currents at -44 mV which increased in a concentration-dependent manner; they desensitized when induced at higher concentrations except for the KA-induced current (IKA). (1S-3R)1-amino-cyclopentane-1,3-dicarboxylate (1S-3R-ACPD) evoked no response. The EC50 and Hill coefficient (nH) values of the GluR responses were 3.3 x 10(-5) M, 0.74 for Glu; 9.0 x 10(-5) M, 0.83 for NMDA; 6.4 x 10(-7) M, 1.30 for QA; 1.3 x 10(-4) M, 1.10 for AMPA and 9.6 x 10(-5) M, 1.30 for KA, respectively. The reversal potentials of the GluR responses were all near 0 mV. The 6-Cyano-7-nitroquinoxaline-2-3-dione (CNQX) and D-2-amino-5-phosphonovalerate (D-APV) suppressed the non-NMDA and NMDA responses in a concentration-dependent manner, respectively. Cyclothiazide strongly potentiated both KA- and AMPA-induced responses while concanavalin A potentiated both the responses to a much lesser degree. NS-102 produced no significant effect on either KA- or AMPA-activated currents, while GYKI 52466 reversibly blocked both the currents. The Ca2+ permeabilities (PCa/PCs) of the NMDA and AMPA receptor channels were 8.33 and 1.23, respectively. In addition, the current-voltage (I-V) relationship of IKA showed little rectification. There was a poor correlation between the Ca2+ permeability and the shape of the I-V curves of IKA. These results suggest that rat SDCN neurons possess NMDA and non-NMDA receptor channels, and express AMPA type receptors with unique properties (slow desensitization to AMPA, high Ca2+ permeability but lack of inward rectification). These ionotropic receptor channels may play important roles in mediating and regulating pelvic visceral information including nociception.