Understanding in vivo carbon precursor supply for fatty acid synthesis in leaf tissue

The principal supply of carbon precursors for fatty acid synthesis in leaf tissue has been a much debated topic, with some experiments suggesting a direct supply from the C3 products of photosynthetic carbon fixation and colleagues suggesting the utilization of free acetate (for which concentrations in leaves in the range of 0.05-1.4 mM have been reported). To address this issue we first reassessed the in vivo rate of fatty acid synthesis using a new method, that of [13C]carbon dioxide labeling of intact Arabidopsis plants with the subsequent analysis of fatty acids by gas chromatography-mass spectrometry (GC-MS). This method gave an average value of 2.3 mmoles carbon atoms h-1 mg chlorophyll-1 for photosynthetic tissues. The method was extended by isotopic dilution analysis to measure the rate of fatty acid synthesis in the dark. There was negligible fatty acid synthesis (< 5% of the rate in the light) in the dark. In addition, the method allowed an estimate of the absolute rate of fatty acid degradation of about 4% of the total fatty acid content per day. With the in vivo rate of fatty acid synthesis in the light defined, if the bulk tissue acetate concentration available for fatty acid synthesis is 1 mM, this acetate pool can sustain fatty acid synthesis for approximately 60 min. When the leaves of Arabidopsis, barley and pea were given a 5 min pulse of [14C]carbon dioxide, the label rapidly appeared in fatty acids with a lag phase of less than 2-3 min. Continuous labeling with [14C]carbon dioxide, for up to 1 h, showed a similar result. Furthermore, 14C-label in free acetate was less than 5% of that in fatty acids. In conclusion, these data suggest that either the bulk pool of acetate is not involved in fatty acid synthesis or the concentration of acetate must be less than 0.05 mM under strong illumination.

Application of a mid-infrared fiber bundle in remote measurement of gas concentrations in a chemical vapor deposition chamber

A fiber bundle has been designed for measurement of gas concentrations in a chemical vapor deposition (CVD) chamber. The bundle is broadband, covering the spectrum range from 500 to 6000 cm(-1). Using this bundle, we have designed Fourier Transform infrared (FTIR) sampling configurations with reduced beam divergence (from 0.4 to 0.1 rad) and focal spot diameters (from 12 to 4 mm). The FTIR spectrum of tetraethoxysilane vapors in a CVD chamber was determined with the bundle and modified SAM connectors. An ellipsoid reflector was designed that yielded improved signal-to-noise ratios (SNR's) in the fiber-based spectra by a factor of 2. The incorporation of this reflector in spectrometers by use of the fiber bundle has the potential to reduce the sampling times for spectra while retaining acceptable SNR's.

Study of a molecular imprinting polymer coated BAW bio-mimic sensor and its application to the determination of caffeine in human serum and urine

A bio-mimic bulk acoustic wave (BAW) sensor was fabricated by coating the caffeine (CAF) template molecular imprinting polymer (MIP). This sensor exhibited high selectivity and a sensitive mass response to CAF. The response range of the sensor was between 5.0 x 10(-9) and 1.0 x 10(-4) M with a detection limit of 5.0 x 10(-9) M at pH 8.0. Recoveries were 96.1-105.6%. Influencing factors were investigated in detail and optimized. When employed to detect real samples, the proposed method proved to be a convenient method with the advantages of high sensitivity, good selectivity and ease of handling.

Properties of acetylcholine receptor ion channels in the acutely dissociated neurons of the marginal division in the rat striatum

Cell-attached mode of patch clamp technique was employed to investigate the properties of acetylcholine (ACh)-induced ion channels in acutely dissociated neurons from the marginal division (MrD) of rat striatum. Two types of conductance states (25 pS and 60 pS) were recorded. The 25 pS channel (more than 80%) was the main type in the neurons of MrD and was described here. The amplitudes of inward currents increased with hyperpolorization and the reversing potential was about 0 mV. Both single short opening and long burst openings were observed in MrD neurons. Two-time constants of these two kinds of ion channels are 0.29 ms, 1.84 ms and 1.96 ms, 18.24 ms, respectively. Average close time can be fitted with two exponential functions, the two time constants are 1.7 ms and 54 ms. Probability of channel opening is about 0.012 and no voltage-dependence was found. The properties of reversing potential, voltage-independence and the form of agonist to the ion channels indicated that the recorded channel currents flow through AChR channels. The mAChR is involved in slow synaptic transmission and Ach can not induce the opening of mAChR ion channel. The binding site of ACh to AChR and the nAChR ion channel are the same protein, ACh can only activate nAChR ion channel directly. Therefore, the recorded ion channels in the present study are nAChR ion channels. The results suggest that nAChR ion channels exist in the neurons of MrD and the MrD probably is involved in learning and memory mechanism of the brain.

Optimizing computerized treatment planning for the Gamma Knife by source culling

PURPOSE

A good plan is crucial to the success of gamma knife treatment, which depends not only on parameters such as the number of shots, shot position, collimator sizes, and shot weight, but also on the number of blocked cobalt sources. However, during treatment, a plug is generally used to block those cobalt sources, so the beam cannot reach critical tissues. We present here an automated method to optimize all of those parameters, and to choose a source set, although the beams of some blocked sources do not hit any critical tissue. This strategy is used to achieve a high dose that better conforms to the tumor shape, and at the same time, avoids healthy tissue.

METHODS AND MATERIALS

Using a workstation that integrates the gamma knife treatment planning system, we developed a two-step optimization algorithm. First, we used a modified Powell's method to optimize the location of the shot, collimator size, and shot weight; we used simulated annealing to determine if the number of shots was adequate using this parameter. Then, simulated annealing was used to determine which cobalt sources we needed to block.

RESULTS

Application of this optimization method in two cases showed that the treatment plan can be much improved when the set of blocked cobalt sources has been taken into consideration.

CONCLUSION

Determining the set of blocked sources is necessary in certain cases. This technique better conforms the desired isodose curves to the outline of the target volume and minimizes damage to the surrounding normal tissues.

An antiinflammatory effect of salmeterol, a long-acting beta(2) agonist, assessed in airway biopsies and bronchoalveolar lavage in asthma

The addition of long-acting beta(2) agonists to inhaled corticosteroid (ICS) therapy in symptomatic patients with asthma improves clinical status more than increasing the dose of ICS. It has been suggested that these benefits could be at the cost of an increase in airway inflammation, but few histopathological studies have been performed in the relevant group. In a double-blind, parallel-group, placebo-controlled study, we randomly assigned 50 symptomatic patients with asthma who were receiving ICS (range, 100 -500 microgram/d) to 12 wk of supplementary treatment with salmeterol (50 microgram twice daily) or fluticasone (100 microgram twice daily) or placebo. Bronchial biopsies and BAL were obtained from 45 patients before and after treatment and analyzed. After treatment with salmeterol there was no deterioration of airway inflammation as assessed by mast cells, lymphocytes, or macrophages in BAL or biopsies, but rather a significant fall in EG1-positive eosinophils in the lamina propria (from a median 18.3 to 7.6 cells/mm, p = 0.01), which was not seen after treatment with fluticasone. The only cellular effect of added fluticasone was a decrease in BAL lymphocyte activation. There was a concurrent improvement in clinical status, more marked with salmeterol than with increased ICS. Thus, adding salmeterol to ICS is not associated with increased "allergic" airway inflammation, but conversely with a complementary antieosinophil effect.

A new subdivision of mammalian neostriatum with functional implications to learning and memory

A new subdivision with distinctive morphological and functional attributes has been identified at the caudomedial margin of the neostriatum and surrounding the rostrolateral border of the globus pallidus in the brains of the rat, cat, monkey, and human. The subdivision is termed marginal division (MrD) based on its location. It is readily distinguishable from the rest of striatum by consisting of spindle-shaped neurons, special connections, and intensely expressed immunoreactivities of many neuropeptides and some monoamines in the fibers, terminals, and neuronal somata. Three-dimensional reconstruction from Nissl-stained sections of the rat brain revealed that the MrD is a flat, pan-shaped zone between the neostriatum and globus pallidus. Functional neuronal connections were delineated by chemical-induced c-Fos expression between the MrD and hippocampus, amygdala, as well as the basal nucleus of Meynert. In rats with chemical lesions of bilateral MrD, learning and memory functions were severely impaired as demonstrated by double blind Y-maze test. Our results thus suggested that the MrD is a distinct part and a universal structure in the neostriatum of the mammalian brain and might play an important role in the mechanism of learning and memory.

[Ciliary neurotrophic factor prevents NO mediated cytotoxicity in cultured hippocampal neurons]

The effects of ciliary neurotrophic factor on nitric oxide (NO)-induced cytotoxicity were examined in primary cultures of rat hippocampal neurons. The neurotoxicity was induced by NO donors, such as sodium nitroprusside (SNP), s-nitroso-N-acetylpenicillamine (SNAP), NOS substrate, L-arginine (L-Arg) and ionomycin (a calcium ionophore). Preincubation of the cultures with ciliary neurotrophic factor (CNTF) for 24 h promoted neuronal survival and decreased the LDH efflux and the level of NO induced by ionomycin. The protective effects of CNTF against NO cytotoxicity were concentration-dependent. The above findings suggest that CNTF promotes the survival of neurons in the hippocampus by preventing NO mediated neurotoxicity.

[The genotype-based haplotype relative risk and transmission disequilibrium test analyses of familial febrile convulsions]

OBJECTIVE

To confirm the linkage of familial febrile convulsions to the short arm of chromosome 6(6p) or the long arm of chromosome 8(8q).

METHODS

The authors finished genotyping of Pst I locus on the coding region of heat shock protein (HSP) 70, 5'untranslated region of HSP70-1, 3' untranslated region of HSP70-2, D8S84 and D8S85. The data were processed by the genotype-based haplotype relative risk(GHRR) and transmission disequilibrium test(TDT) methods in PPAP.

RESULTS

Some signs of association and disequilibrium between D8S85 and FC were shown by GHRR and TDT.

CONCLUSION

A suspect linkage of familial febrile convulsions to the long arm of chromosome 8 has been proposed.

Simultaneous distributed strain and temperature measurement

Brillouin-scattering-based sensors are capable of measuring either the strain or the temperature along the length of an optical fiber in a distributed fashion through measurement of the Brillouin-frequency shift. The cross sensitivity of the frequency shift to these two parameters makes it impossible to differentiate between them by measurement of the frequency shift alone. We report on a new technique that permits the simultaneous measurement of strain and temperature to resolutions of +/-178 microepsilon and +/-3.9 degrees C at a spatial resolution of 3.5 m by incorporation of the Brillouin-loss peak power with the conventional Brillouin-frequency measurement.

Supply of fatty acid is one limiting factor in the accumulation of triacylglycerol in developing embryos

The metabolic factors that determine oil yield in seeds are still not well understood. To begin to examine the limits on triacylglycerol (TAG) production, developing Cuphea lanceolata, Ulmus carpinifolia, and Ulmus parvifolia embryos were incubated with factors whose availability might limit oil accumulation. The addition of glycerol or sucrose did not significantly influence the rate of TAG synthesis. However, the rate of (14)C-TAG synthesis upon addition of 2.1 mM (14)C-decanoic acid (10:0) was approximately four times higher than the in vivo rate of TAG accumulation in C. lanceolata and two times higher than the in vivo rate in U. carpinifolia and U. parvifolia. In C. lanceolata embryos, the highest rate of (14)C-TAG synthesis (14.3 nmol h(-1) embryo(-1)) was achieved with the addition of 3.6 mM decanoic acid. (14)C-Decanoic acid was incorporated equally well in all three acyl positions of TAG. The results suggest that C. lanceolata, U. carpinifolia, and U. parvifolia embryos have sufficient acyltransferase activities and glycerol-3-phosphate levels to support rates of TAG synthesis in excess of those found in vivo. Consequently, the amount of TAG synthesized in these oilseeds may be in part determined by the amount of fatty acid produced in plastids.

Early intervention promotes intellectual development of premature infants: a preliminary report. Early Intervention of Premature Infants Cooperative Research Group

OBJECTIVE

To evaluate the effect of early intervention on the intellectual development of the premature infants.

METHODS

Premature infants at gestational age of 28-36.9 weeks were randomly divided into two groups: intervention and conventional care groups. Normal newborn infants during the same period were included in the control group (routine care). Up to March 1996, 156 cases were over the age 1.5-2 years (corrected age), 52 in the intervention group, 51 in the conventional care group and 53 in the normal control group. Parents were taught to carry out the 0-2 year intervention program, which included motor, cognitive, speech development and social behavior. Every three months, height, weight and head circumference were measured. At the age of one and a half and two years, all infants in the three groups received infant development tests of Child Development Center of China (CDCC) scale. The examiner did not know which infant had received intervention.

RESULTS

There was no significant difference in biological factors among the two premature groups and in cultural and social factors among the three groups. Intelligence tests at the age of one and a half and two years showed that the average mental development index (MDI) in the intervention group was 13.8 and 14.6 higher than those in the conventional care group and the differences were significant. The psychomotor development index (PDI) was 5.2 and 4.7 higher but the differences were not significant. The MDI and PDI in the intervention group and normal control were quite close, but at two years, the MDI and PDI in the intervention group were 5.7 and 7.3 higher than those in the normal control and the differences were significant (P < 0.05). Compared with the normal control, the MDI in conventional care group at one and a half and two years of age were 11.5 and 8.9 lower. The difference was very significant. There were four cases of mental retardation, whose mental development index (MDI) was less then 70 in the conventional care group, but none in the intervention group.

CONCLUSIONS

Early intervention can promote intellectual development of the premature infants and may be beneficial to the prevention of mental retardation. Early and intensive intervention can produce better results. Bringing parent's initiative into full play through deepening their understanding of the importance of early intervention is the key to success.

[Computerized ribosomal RNA secondary structure modeling of mutants found in Rett syndrome patients and their mothers]

OBJECTIVE

To identify the secondary structure of rRNA mutants, mtDNA2835(C-->T) and mtDNA2706(A-->G) found in Rett syndrome patients and their mothers.

METHODS

Both wild type mtDNA sequence of rRNA gene and mutated sequence were input into computer (converted into RNA sequences) and analyzed by the sofware DNASIS v6. 14. The unique prediction size is set 300 bases and the maximum bulge and interior loop size,30 bases.

RESULTS

Similar to the positive controls, the mtDNA2835(C-->T) made the 16S rRNA secondary structure totally different,and the energy changes a lot. On the contrary, the mtDNA2706(A-->G) altered little of secondary structure with a small energy shift.

CONCLUSION

Computerized folding programs have provided us with a quick prediction of rRNA structure changes induced by these two mutations. Of them, the mtDNA2835(C-->T) might relate to the pathogenesis of Rett syndrome, but the mtDNA2706(A--> G) might be less meaningful.

Structural monitoring by use of a Brillouin distributed sensor

The testing of a fiber-optic distributed-strain sensor attached to a simple structural member is reported. A Brillouin scattering-based sensor system was used to measure both tensile and compressive strains along the length of a cantilever beam subjected to various loads. The sensing fiber was attached to the beam in such a way that some sections experienced uniform strain, whereas others were subjected to a nonuniform strain distribution. A spatial resolution of 0.4 m was used, and a measurement precision of approximately +/-50 microepsilon was achieved.

Characterization of the Brillouin-loss spectrum of single-mode fibers by use of very short (<10-ns) pulses

The characterization of the Brillouin-loss spectrum of single-mode fibers with very short (<10-ns) pulses has been studied. It was found that the Brillouin-loss signal intensity is linearly related to the duration of the pump pulse used to obtain the spectrum. In contrast with the uniform trend of the signal, three distinct behaviors were observed in the spectral linewidth. At long pulse durations the linewidth was constant at approximately 40 MHz. Pulse durations of the order of the phonon lifetime resulted in a broader spectrum, reaching a maximum width of ~100 MHz at 5 ns. Reducing the pulse duration further resulted in a sudden narrowing of the Brillouin line.

Temporal gradient in shear but not steady shear stress induces PDGF-A and MCP-1 expression in endothelial cells: role of NO, NF kappa B, and egr-1

Three well-defined laminar flow profiles were created to distinguish the influence of a gradient in shear and steady shear on platelet-derived growth factor A (PDGF-A) and monocyte chemoattractant protein-1 (MCP-1) expression in human endothelial cells. The flow profiles (16 dyne/cm2 maximum shear stress) were ramp flow (shear stress smoothly transited at flow onset), step flow (shear stress abruptly applied at flow onset), and impulse flow (shear stress abruptly applied for 3 s only). Ramp flow induced only minor expression of PDGF-A and did not increase MCP-1 expression. Step flow increased PDGF-A and MCP-1 mRNA levels 3- and 2-fold at 1.5 hours, respectively, relative to ramp flow. In contrast, impulse flow increased PDGF-A and MCP-1 expression 6- and 7-fold at 1.5 hours, and these high levels were sustained for at least 4 hours. These results indicate that a temporal gradient in shear (impulse flow and the onset of step flow) and steady shear (ramp flow and the steady component of step flow) stimulates and diminishes the expression of PDGF-A and MCP-1, respectively. NO synthase inhibitor NG-amino-L-arginine (L-NAA) was found to markedly enhance MCP-1 and PDGF-A expression induced by step flow, but decrease their expression induced by impulse flow, in a dose-dependent manner. NO donor spermine-NONOate (SPR/NO) dose-dependently reduced the MCP-1 and PDGF-A expression induced by impulse flow. Moreover, impulse flow was found to stimulate sustained (4 hours) I kappa B-alpha degradation and egr-1 mRNA induction. L-NAA prevented I kappa B-alpha degradation, whereas SPR/NO increased I kappa B-alpha resynthesis 2 hours after impulse flow. Both L-NAA and SPR/NO inhibited the impulse flow inducibility of egr-1 4 hours after the flow stimulation. The results show that both NO induced by steady shear and NO donor inhibit temporal gradient in shear-induced MCP-1 and PDGF-A expression by downregulation of their respective transcription factors NF kappa B and egr-1, whereas NO induced by impulse flow stimulates MCP-1 and PDGF-A expression by upregulation of the transcription factors. The above findings suggest distinct roles of temporal gradient in shear and steady shear in atherogenesis in vivo.

[The development of a two-channel impedance pneumography]

To obtain respiratory signals with impedance method at two measuring frequencies, a high-performance two-channel impedance pneumography was implemented and the software including acquisiting data, showing waves, storing datas were developed. Human experiment was done and the results were also presented.

[Investigation and identification of "shihu" medicinal materials from Shanghai]

"Shihu" medicinal materials from Shanghai were investigated, colrected and identified. The results showed that the main varietis are the plants from Dendrobium, the small number from Flickingeria and Pholidota.

[Expression of xylose isomerase gene(xylA) in Saccharomyces cerevisiae from Clostridium thermohydrosulfuricum]

The Clostridium thermohydrosulfuricum xylA gene encoding xylose(glucose) isomerase was cloned in the yeast expression vector pMA91 under the control of the PGK promoter, resulting in pBX-1, and transformed into Saccharomyces cerevisiae. Production of recombinant xylose isomerase was seen in the a Coomassie stained SDS-PAGE gel and the molecular mass was estimated to be 43 kD. The recombinant xylose isomerase showed the highest activity at 85 degrees C and pH7. The specific activity under these condition was 1.0 U/mg protein. At 30 degrees C and 40 degrees C, the relative activity was reduced to 3.7% and 11%, respectively, of the maximum.

[The origin of Chinese animal drug "hu-di-long" (Shanghai pheretima)]

Results of identification showed that the origin of the Chinese animal drug "Hu-Di-Long" is the dried body of Pheretima vulgaris Chen, P. guillelmi (Michaelsen) or P. pectinifera Michaelsen. The results have been specified in the Pharmacopoeia of the People's Republic of China (1995).

Three-dimensional optimization of treatment planning for gamma unit treatment system

During a treatment using the Leksell gamma unit, the physician and physicist need to determine a treatment plan by changing the parameters such as collimator sizes, the position of isocenters and isocenters' weights. This is a complex problem because the set of parameters is large, especially when targets are geometrically close to a critical structure. For this reason, we present here an optimization algorithm, namely the multiplier penalty method, to mathematically determine those parameters. Two cases are presented in this article: the first one is really planned by a physicist in a clinical treatment, and is redone in our optimization algorithm to show the effectiveness of this method; the second one is theoretical where a critical structure is placed close to the target volume. The results show that this method achieves an excellent conformation to the specified isodose curve with the contour of the target volume, allowing minimal damage to surrounding healthy tissue.

Antisense fosB RNA inhibits thrombin-induced hypertrophy in cultured pulmonary arterial smooth muscle cells

BACKGROUND

We have previously reported that fosB mRNA is induced by hypertrophic stimuli (thrombin, angiotensin II) but not proliferative stimuli (platelet-derived growth factor, basic fibroblast growth factor) in pulmonary arterial smooth muscle cells (PASMCs) (J Biol Chem. 1994;9:6399-6404). Our aim in the present study was to investigate the potential role of FosB in PASMC hypertrophy.

METHODS AND RESULTS

Adenoviruses carrying sense or antisense fosB RNA expression cassettes were used to infect cultured PASMCs with the aim of increasing or inhibiting fosB expression, respectively. We examined whether fosB expression modification affected the growth of quiescent PASMCs, thrombin-induced hypertrophy, or platelet-derived growth factor-induced proliferation. PASMC growth was assessed by daily cell number count, determination of [3H]leucine incorporation, and quantification of total cellular protein. Neither an increase nor a decrease in FosB protein expression caused a significant change in the growth of quiescent PASMCs over a period of 96 hours, indicating that FosB alone is not sufficient to induce hypertrophy. Modification of FosB levels did not affect platelet-derived growth factor-induced PASMC proliferation. An increase in FosB expression did not augment thrombin-induced hypertrophy; however, inhibition of FosB expression resulted in a diminution of thrombin-induced hypertrophy by 58+/-6% (P<0.005).

CONCLUSIONS

These results suggest that FosB is necessary but not sufficient for thrombin-induced hypertrophy in cultured PASMCs.

Brainstem auditory-evoked potential evaluation in children with meningitis

Brainstem auditory-evoked potential (BAEP) was performed on 101 children with meningitis to assess the incidence of hearing impairment. Fifty-two (51.5%) children had bacterial meningitis, six (5.9%) had viral meningitis, and 43 (42.6%) had aseptic meningitis. Fifty-one (50.5%) patients were assessed before discharge and 50 (49.5%) 9 days to 17 months later (mean = 4 months). BAEP impairment was found in 28 (27.7%) of 101 patients; 24 had sensorineural and four had conductive type of hearing loss, and 17 (60.7%) had unilateral and 11 (39.3%) had bilateral impairment. Hearing threshold was elevated in 22 (21.8%) patients, and the other six had increased latency and interpeak latencies with normal threshold. Frequency of BAEP impairment or hearing loss associated with bacterial meningitis was 34.6% and 30.8%, respectively; frequency associated with aseptic meningitis was 20.9% and 13.9%, respectively. One child with viral meningitis (coxsackie virus) had mild BAEP impairment. Most of the BAEP impairment in the bacterial meningitis group was associated with H. influenzae. Prospective BAEP study was performed in 20 patients randomly at 0.3 to 18 months to assess hearing status after antibiotic treatment, 10 with normal and 10 with abnormal BAEP. All the initially normal BAEP patients remained normal. Of the 10 patients with abnormal BAEP results initially, four returned to normal, two improved, three remained unchanged, and one deteriorated. The incidence of hearing loss after bacterial and aseptic meningitis is high. BAEP is useful to screen for possible hearing loss in children with meningitis, and follow-up BAEP is necessary for those patients with initially abnormal BAEP.

Effects of benazepril on insulin resistance and glucose tolerance in uremia

This study tested whether the angiotensin-converting enzyme inhibitor (ACEI) benazepril can improve the insulin resistance and glucose tolerance in uremia. Fifteen uremic hypertensive patients were treated with benazepril in a dose of 10-20 mg per day for ten weeks, and ten healthy subjects, matched in age, sex ratio and body mass index (BMI), served as the control group. Before and after the treatment, an oral 75 g glucose tolerance test (OGTT) and insulin release test (IRT) were performed in two groups above, and the blood glucose and serum insulin concentrations at 0, 60, 120 and 180 minutes after glucose load were examined, and the insulin glycoregulatory activity, including insulin sensitivity index (ISI), glucose uptake rate (M), total areas under the glucose and insulin curves during OGTTs (AUCG AUCINS), was calculated. The changes of serum potassium and renal function before and after treatment were observed. It showed that (1) benazepril could reduce blood pressure significantly (SBP decreased from 174.8 +/- 12.0 mmHg to 151.5 +/- 9.0 mmHg, p <0.001; DBP decreased from 108.0 +/- 8.2 mmHg to 95.3 +/- 9.0 mmHg, p <0.001). The total response rate was 86.7%. (2) After treatment with benazepril for ten weeks, the blood glucose and serum insulin concentrations after glucose load and AUCG, AUCINS values in the uremic patients were significantly lower than before treatment, but were still significantly higher than in the controls. The values of ISI and M in the uremic patients after treatment were much higher than before treatment, but were still significantly lower than in the control subjects. (3) The differences of serum potassium and creatinine levels before and after treatment were not significant. These findings indicate that benazepril can not only reduce blood pressure effectively and safely, but also partly improve insulin resistance, hyperinsulinemia and glucose intolerance in uremia.

Somatostatin immunoreactivity in esophageal premotor neurons of the rat

Esophageal peristalsis is coordinated by premotor neurons localized to the central subnucleus of the nucleus of the solitary tract (NTScen). These premotor neurons project directly to motoneurons within the compact formation of the nucleus ambiguus (NAc). Somatostatin immunoreactive terminals have been previously demonstrated encircling motoneurons in the (NAc) (Cunningham, E.T., Jr. and Sawchenko, P.E., J. Neurosci., 9 (1989) 1668-1682). We combined transsynaptic tracing with pseudorabies virus and immunohistochemistry to localize somatostatin to premotor neurons within the NTScen.

[Detection of Mycobacterium tuberculosis DNA in peripheral blood mononuclear cells from patients with pulmonary tuberculosis by polymerase chain reaction technique]

OBJECTIVE

To evaluate the clinical value of detection of Mycobacterium tuberculosis DNA (MTB-DNA) in peripheral blood mononuclear cells (PBMC) for diagnosis of pulmonary tuberculosis.

METHOD

Polymerase chain reaction (PCR) technique was used to amplify gene of 240 bp DNA fragment prepared by Triton X-100 method, and some factors affecting PCR result were also analysed.

RESULT

In blood samples of 89 patients with pulmonary tuberculosis and in sputum samples of 84 patients with pulmonary tuberculosis, the positive rates of PCR were 73% and 57% respectively, and the total positive rate of combinative detection of blood and sputum samples was 87% in 84 pulmonary tuberculosis patients. In 30 non-tuberculosis patients, 3 showed MTB-DNA positive.

CONCLUSION

PCR technique prepared by Triton X-100 method is rapid, simple, specific, and sensitive for detection of MTB-DNA in PBMC, and its sensitivity and accuracy could be increased in combination with sputum MTB examination. Detection of MTB-DNA in PMBC is of value in diagnosis of pulmonary tuberculosis.

Investigation of the metabolism of 7-(4-chlorbenzyl)-7,8,13,13a-tetrahydroberberine chloride in the rat

The metabolism of 7-(4-chlorbenzyl)-7,8,13,13a-tetrahydroberberine chloride (CTHB), a compound with promising pharmacological effects against arrhythmia, was investigated in rat bile. A metabolite and unchanged CTHB were found in the bile. Characterization and structural elucidation of the metabolite was achieved by LC/MS and LC/NMR. The following metabolic pathway is proposed: CTHB is metabolized by demethylation at position 10 to produce a new entity.

[Diagnosis and surgical treatment of intramedullary epidermoid cyst of the spinal cord]

OBJECTIVE

To discuss clinical diagnosis and surgical treatment of intra-medullary epidermoid cyst.

METHODS

Ten intramedullary epidermoid cysts were confirmed by operatively and pathologically from 1978 to 1995.

RESULTS

The tumors were located in the spinal cord. Clinical presentation of this tumor was not specific. On CT scans, eight tumors were characterized by a homogenous low-density lesion and well-defined limits. They usually did not enhance with contrast medium. On MR imaging, four tumors were characterized by an important variability of signal intensity, well-defined limits. All patients underwent resections of epidermoid cyst, 1 total resection, and 9 subtotal resections. Eight cases were followed up from half a year to seven years. No case recurred.

CONCLUSION

Total resection of epidermoid cyst is the best choice.

Early intervention improves intellectual development in asphyxiated newborn infants. Intervention of Asphyxiated Newborn Infants Cooperative Research Group

OBJECTIVE

To evaluate the effect of early intervention on the intellectual development in asphyxiated newborn infants.

METHODS

Full term asphyxiated infants (Apgar score < or = 6 at 5 minutes after birth) were randomly assigned to early intervention group (34 cases) and conventional care (30 cases) group. The normal control group consisted of 38 infants. Sex, mother's educational background, environmental condition and physical development were not significantly different in the 3 groups. Zero to two years early intervention program was compiled on basis of the national and foreign material about 1 month ahead of average development of the child. It included motor, cognitive, speech development and social behavior. Parents were instructed to carry out early intervention.

RESULTS

At the age of 1.5 years, average score of mental development index (MDI) in early intervention group was 14.6 higher than that in conventional care group (F = 18.86, P < 0.0001). MDI score in early intervention group caught up with that in normal control group (F = 2.17, P > 0.05). Conventional care group was 9.7 lower than normal control group (F = 10.14, P < 0.01). Two of 30 cases (6.7%) in conventional care group was mentally retarded while none was mentally retarded in the early intervention group.

CONCLUSIONS

The results showed that the early intervention could promote intellectual development of asphyxiated infants and be of much benefit to the prevention of mental retardation.

Isolation and characterization of an Arabidopsis biotin carboxylase gene and its promoter

In the plastids of most plants, acetyl-CoA carboxylase (ACCase; EC 6.4.1.2) is a multisubunit complex consisting of biotin carboxylase (BC), biotin-carboxyl carrier protien (BCCP), and carboxytransferase (alpha-CT, beta-CT) subunits. To better understand the regulation of this enzyme, we have isolated and sequenced a BC genomic clone from Arabidopsis and partially characterized its promoter. Fifteen introns were identified. The deduced amino acid sequence of the mature BC protein is highly conserved between Arabidopsis and tobacco (92.6% identity). BC expression was evaluated using northern blots and BC/GUS fusion constructs in transgenic Arabidopsis. GUS activity in the BC/GUS transgenics as well as transcript level of the native gene were both found to be higher in silique and flower than in root and leaf. Analysis of tobacco suspension cells transformed with truncated BC promoter/GUS gene fusions indicated the region from -140 to +147 contained necessary promoter elements which supported basal gene expression. A positive regulatory region was found to be located between -2100 and -140, whereas a negative element was possibly located in the first intron. In addition, several conserved regulatory elements were identified in the BC promoter. Surprisingly, although BC is a low-abundance protein, the expression of BC/GUS fusion constructs was similar to 35S/GUS constructs.

Expression of different levels of enzymes from the Pichia stipitis XYL1 and XYL2 genes in Saccharomyces cerevisiae and its effects on product formation during xylose utilisation

Saccharomyces cerevisiae was transformed with the Pichia stipitis CBS 6054 XYL1 and XYL2 genes encoding xylose reductase (XR) and xylitol dehydrogenase (XDH) respectively. The XYL1 and XYL2 genes were placed under the control of the alcohol dehydrogenase 1 (ADH1) and phosphoglycerate kinase (PGK1) promoters in the yeast vector YEp24. Different vector constructions were made resulting in different specific activities of XR and XDH. The XR:XDH ratio (ratio of specific enzyme activities) of the transformed S. cerevisiae strains varied from 17.5 to 0.06. In order to enhance xylose utilisation in the XYL1-, XYL2-containing S. cerevisiae strains, the native genes encoding transketolase and transaldolase were also overexpressed. A strain with an XR:XDH ratio of 17.5 formed 0.82 g xylitol/g consumed xylose, whereas a strain with an XR:XDH ratio of 5.0 formed 0.58 g xylitol/g xylose. The strain with an XR:XDH ratio of 0.06, on the other hand, formed no xylitol and less glycerol and acetic acid compared with strains with the higher XR:XDH ratios. In addition, the strain with an XR:XDH ratio of 0.06 produced more ethanol than the other strains.

Clinical treatment planning optimization by Powell's method for gamma unit treatment system

PURPOSE

This article presents a new optimization method for stereotactic radiosurgery treatment planning for gamma unit treatment system.

METHODS AND MATERIALS

The gamma unit has been utilized in stereotactic radiosurgery for about 30 years, but the usual procedure for a physician-physicist team to design a treatment plan is a trial-and-error approach. Isodose curves are viewed on two-dimensional computed tomography (CT) or magnetic resonance (MR) image planes, which is not only time consuming but also seldom achieves the optimal treatment plan, especially when the isocenter weights are regarded. We developed a treatment-planning system on a computer workstation in which Powell's optimization method is realized. The optimization process starts with the initial parameters (the number of isocenters as well as corresponding 3D isocenters' coordinates, collimator sizes, and weight factors) roughly determined by the physician-physicist team. The objective function can be changed to consider protection of sensitive tissues.

RESULTS

We use the plan parameters given by a well-trained physician-physicist team, or ones that the author give roughly as the initial parameters for the optimization procedure. Dosimetric results of optimization show a better high dose-volume conformation to the target volume compared to the doctor's plan.

CONCLUSION

This method converges quickly and is not sensitive to the initial parameters. It achieves an excellent conformation of the estimated isodose curves with the contours of the target volume. If the initial parameters are varied, there will be a little difference in parameters' configuration, but the dosimetric results proved almost to be the same.

[Effects of spinal cord extract on neurite growth of GABAergic and dynergic neurons of spinal cord in vitro]

We use the crude extract from human fetal spinal cord to study the effect of endogenous substances of the spinal cord on neurite growth of E 12-15 mouse GABAergic and DNYergic neurons of the spinal cord in vitro. The results indicated that the crude extract had no effect on GABAergic neurons but had markedly neurite-promoting effect on DNYergic neurons when the protein concentration of the crude extract was 250 micrograms/ml. It suggests that there are endogenous substances in the crude extract of the human fetal spinal cord, which can promote neurite growth of spinal cord neurons and this effect is neuron type specific at particular embryonic age.

[Changes in membrane potential of cultured mouse neuron during mitosis]

Primarily cultured dorsal root ganglion cells and olfactory bulb cells were dissected from 12 to 14-d-old fetal C57 BL/6 J mice. After the cells were cultured for about two weeks, the growing status of cells were observed and the membrane potentials(MP) were recorded. The results show that mean value of the MP in anaphase was -68 +/- 3.1 mV (SE, n = 3), same as in interphase: Beginning from telophase, the cell membrane in the equator contracted gradually to become a concave ditch, and the MP decreased obviously, the mean value was -23.3 +/- 3.3 mV (SE, n = 6). After this, MP recovered gradually, till it divided into two sister cells. MP which were recorded separately in two sister cells were similar. But usually MP did not recovered to their normal values immediately.

Effect on product formation in recombinant Saccharomyces cerevisiae strains expressing different levels of xylose metabolic genes

The XYL1 and XYL2 genes from Pichia stipitis encoding xylose reductase (XR) and xylilitol dehydrogenase (XDH), respectively, were transformed into Saccharomyces cerevisiae. These two genes were placed in different directions under the control of the alcohol dehydrogenase I (ADHI) and phosphoglycerate kinase (PGK) promoters and inserted into the E. coli-yeast shuttle plasmid YEp24. Different recombinant S. cerevisiae strains were constructed with different specific activities of XR and XDH. The highest XR or XDH activities were obtained when the expressed gene was controlled by the PGK promoter and located downstream after the ADHI promoter-gene-terminator sequence. The XR/XDH ratio (ratio of specific enzyme activities of XR and XDH) in these recombinant S. cerevisiae strains varied from 17.5 to 0.06. In order to enhance xylose utilization, in the XYL1, XYL2 containing S. cerevisiae strains, the native TKL1 gene encoding transketolase and the TALI gene encoding transaldolase were also overexpressed, which showed considerably good growth on the xylose plate. Fermentation of the recombinant S. cerevisiae strains containing XYL1, XYL2, TKL1, and TAL1 were studied with mixtures of glucose and xylose. The strain with XR/XDH ratio of 0.06 consumed 3.25 g/L xylose and formed no xylitol and less glycerol and acetic acid, but more ethanol compared with the strains with a higher XR/XDH ratio.

Ethanolic fermentation of xylose with Saccharomyces cerevisiae harboring the Thermus thermophilus xylA gene, which expresses an active xylose (glucose) isomerase

The Thermus thermophilus xylA gene encoding xylose (glucose) isomerase was cloned and expressed in Saccharomyces cerevisiae under the control of the yeast PGK1 promoter. The recombinant xylose isomerase showed the highest activity at 85 degrees C with a specific activity of 1.0 U mg-1. A new functional metabolic pathway in S. cerevisiae with ethanol formation during oxygen-limited xylose fermentation was demonstrated. Xylitol and acetic acid were also formed during the fermentation.

[Intramedullary spinal teratoma]

We treated 5 cases of intradullary spinal teratomas from 1974 to 1995, accounting 0.636% of all intraspinal tumors and 45.45% of all teratomas of spinal cord admitted in the same time. The origin of this tumor is controversial. It is not easy to differentiate this tumors from other intramedullary spinal tumors on clinical grounds. CT and MR scans of this tumor enabled us to make the preoperative diagnosis of teratoma. Resection is the only treatment of choice.

[Mutation analysis of mitochondrial DNA of children with Rett syndrome]

OBJECTIVE

To identify whether mitochondrial DNA (mtDNA) mutation is involved in the pathogenesis of Rett syndrome (RS), we undertook a mutation analysis of the mtDNA genome.

METHODS

mtDNA from 15 children with RS and 14 their mothers were analysed by using Southern hybridization, polymerase chain reaction (PCR), single strand conformation polymorphism (SSCP) and DNA direct sequencing. Total DNA was isolated from white blood cells.

RESULTS

Southern hybridization with whole mtDNA probe revealed no large deletions in mtDNA. PCR amplification and SSCP analysis showed mutation(s) in the region 2650-3000 encoding 16SrRNA of mtDNA in 13 RS patients and 11 their mothers. DNA sequence analysis and mismatch PCR showed a point mutation (C-->T) at the position 2835 in 7 RS patients and 6 their mothers. The same mutation was not found in 30 normal controls.

CONCLUSION

These data indicate that mtDNA may play a role in Rett syndrome.

Co-localization of NOS and NMDA receptor in esophageal premotor neurons of the rat

Nitric oxide (NO) production following NMDA receptor stimulation plays a role in signaling between neurons. Using trans-synaptic tracing with pseudorabies virus (PRV), immunocytochemistry and histochemistry, we have demonstrated the expression of NMDAR1 and nitric oxide synthase (NOS) within brain stem neurons controlling esophageal peristalsis. PRV-immunoreactive second order esophageal premotor neurons of the central subnucleus of the nucleus of the solitary (NTScen) expressed NMDAR1 and NOS. First order motoneurons of the compact formation of the nucleus ambiguus (NAc) expressed NMDAR1, but did not contain NOS. NTScen neurons may synthesize and release NO in response to NMDA activation, suggesting a role for NO in the coordination of esophageal motility.

Transsynaptic localization of pharyngeal premotor neurons in rat

We determined the anatomy and connectivity of the brainstem circuit controlling the buccopharyngeal phase of swallowing, using pseudorabies virus to identify linked circuits of neurons. Pharyngeal vagal afferents terminate on premotor neurons in the interstitial and intermediate subnuclei of the nucleus of the solitary tract, which in turn, innervate pharyngeal motoneurons in the semicompact subnucleus of the nucleus ambiguus. This circuit is separate and distinct from the esophageal swallowing circuit.

Localization of nitric oxide synthase in the brain stem neural circuit controlling esophageal peristalsis in rats

BACKGROUND/AIMS

The central subnucleus of the nucleus of the solitary tract has been implicated in central reflex control of esophageal peristalsis. This study determined the presence of nitric oxide synthase in the brain stem circuit controlling esophageal peristalsis by combining transsynaptic retrograde tract tracing with pseudorabies virus and nicotinamide adenine dinucleotide phosphate diaphorase (NADPH) histochemistry.

METHODS

Virus was injected into the esophagus of 10 of 15 rats. After 60-63 hours, brain sections were processed for viral immunofluorescence and NADPH histochemistry.

RESULTS

Fluorescent neuronal labeling was limited to the compact formation of the nucleus ambiguus and the central subnucleus of the nucleus of the solitary tract. Most fluorescence-labeled neurons in the central subnucleus stained positively for NADPH (double labeled). In the compact formation, there were almost no double-labeled neurons; however, NADPH-stained terminals surrounded fluorescence-labeled motoneurons.

CONCLUSIONS

NO synthase is present in premotor neurons of the central subnucleus of the nucleus of the solitary tract that innervate esophageal motoneurons in the compact formation of the nucleus ambiguus. NADPH staining in both somata and terminals of esophageal premotor neurons suggests that NO is involved in neurotransmission in the central subnucleus and at the site of synaptic contact between esophageal premotor neurons and motoneurons in the compact formation of the nucleus ambiguus.

[Identification on the botanical origin of xueshangyizhihao produced in Shaanxi, Gansu, Sichuan Provinces and Ningxia Hui Autonomous Region]

The botanical origin of Xueshangyizhihao should be Aconitum brachypodum var. laxiflorum produced in Dongchuan, Huize and Xundian districts in Yunnan Province. Recently, this herb has been found coming from Shaanxi, Gansu, Sichuan Provinces and Ningxia Hui Autonomous Region. Botanical identification show that except the one from Sichuan being of the same origin as that from Yunnan, this herb consists essentially of the species of genus Aconitum, mainly A. flavum, A. pendulum, and others such as A. sungpanense, A. polyschistum and A. iudlowii.

The relationship of Piry virus to other vesiculoviruses: a re-evaluation based on the glycoprotein gene sequence

By sequencing the 3 half of the Piry virus genome, we show that Piry virus, like the other vesiculoviruses, contains the genes for nucleoprotein N, phosphoprotein P, matrix protein M, glycoprotein G and polymerase protein L, in that order. Our analysis of the Piry G protein sequence suggests that Piry and Chandipura are related to each other as closely as the Indiana and New Jersey vesicular stomatitis virus serotypes are to each other. A re-examination of amino acid sequences in the nucleocapsid protein shows that this relationship is also true of the more conserved central region of this protein and that the greatest divergence between Piry and Chandipura has occurred in two other regions of the nucleocapsid protein.