Topography of neuron loss in the retinal ganglion cell layer in human glaucoma

AIM

To determine if retinal ganglion cell (RGC) loss influences the loss of surrounding RGCs to generate clustered patterns of cell death in human glaucoma. It is hypothesised that retinal ganglion cell loss accelerates the loss of surrounding cells to generate, at a local, cellular scale, clustered patterns of retinal of RGC death. The absence of these interactions would result in a diffuse pattern RGC loss.

METHOD

Six glaucomatous retinas (67-83 years old) and six age-matched control retinas (61-89 years old) were prepared as wholemounts and stained by 4',6-diamidino-2-phenylindole (DAPI) solution (3 microg/ml in PBS). An area corresponding to central 14 degrees of the visual field was imaged. The nearest-neighbour distribution was determined for cells in both normal and glaucomatous RGCL.

RESULTS

Clustered RGC loss in human glaucoma was observed on a background of diffuse loss. The mean nearest-neighbour distance (NND) of the glaucomatous retinas was significantly higher than with controls (p<0.001). The distribution of NND in glaucomatous retinas was skewed to the higher values with a higher positive kurtosis relative to controls. The quantitative analysis of the pattern of cell loss is supported by the visual inspection of the patterns of cell loss.

DISCUSSION

The nearest-neighbour analysis is consistent with the presence of two patterns of cell loss in the RGCL in glaucoma. While the diffuse of cell loss can account for an overall reduction in the RGC population, an additional non-random pattern is consistent with the hypothesis that RGC loss has a local influence on the viability of surrounding cells.

Enhancing embryo yield in superovulated holstein heifers by immunization against inhibin

Eight heifers, aged 16-17 months and showing normal oestrous cycles, were immunized against a recombinant porcine inhibin alpha subunit immunogen, together with another 10 heifers of the same age as controls and treated with placebo immunogen. Primary (1 mg immunogen) and two booster (0.5 mg immunogen each) immunizations were administered at 28-day intervals. Ten days after the second booster immunization, both groups of heifers underwent a superovulation treatment. Each animal was given an intravaginal progesterone releasing sponge, which was withdrawn 7 days following an i.m. injection of 0.5 mg cloprostenol. Heifers were treated with FSH for 4 days and artificially inseminated after oestrus occurred. The embryos were flushed and evaluated 7 days after insemination. Immunization significantly (p < 0.01) increased blood antibody titres against recombinant porcine inhibin alpha subunit, from pre-immunizaion and control values of approximately 0.06 of ELISA 450 nm reading to 0.6 to 0.7 after two or three immunizations. The immunized heifers produced on average 15.8 +/- 2.8 embryos, significantly (p < 0.05) higher than the yield of 8.3 +/- 1.5 in the controls. The number of transferable embryos were non-significantly higher in immunized than in control heifers (9.6 +/- 3.1 vs 5.8 +/- 1.6, p > 0.05). The peak plasma oestradiol concentrations were significantly higher in immunized than in control heifers, both immediately after FSH treatment and 20 days thereafter. Plasma P4 concentrations after superovulation were in the range of 20 ng / ml in the immunized heifers, significantly (p < 0.05) higher than the values approximately 15 ng / ml in control heifers. These results indicated that prior immunization against inhibin alpha subunit stimulated production of antibodies against inhibin, which enhanced follicular developmental response to superovulation and lead to higher yield of total and transferable embryos. Therefore immunization combined with the conventional superovulatory gonadotrophin treatment, can be a simple and efficient method to produce low cost bovine embryos.

Multiple logistic regression analysis of risk factors for carcinogenesis of oral submucous fibrosis in mainland China

Oral submucous fibrosis (OSF), a chronic progressive disorder, is regarded as the premalignant lesion of oral squamous cell carcinoma (OSCC). Its distribution is associated with chewing betel quid (BQ). The objective of the present study was to investigate risk factors for the carcinogenesis of OSF in mainland China. A case-control study was performed in 42 patients with OSCC that originated from OSF and 40 OSF controls. Epidemiological data and information related to risk factors were collected using a short structured questionnaire. Odd ratios (OR) and 95% confidence intervals (CI) were derived from logistic regression analysis. In multivariate analysis, only age, duration of BQ chewing, duration of cigarette smoking, and OSF accompanied by oral leukoplakia or oral lichen planus were associated with significantly increased risk for the malignant transformation of OSF. These findings contribute to current knowledge on the prevention of carcinogenesis of OSF in mainland China.

Outcome of floppy Nissen fundoplication with intraoperative manometry to treat sliding hiatal hernia

The aim of this study was to evaluate the effectiveness of floppy Nissen fundoplication with intraoperative esophageal manometry. Between February 1992 and July 2004, there were 102 patients with sliding hiatal hernia undergoing transabdominal Nissen fundoplication. They were divided into three groups: 27 patients were in the Nissen group (CNF), 44 in the floppy Nissen group (FNF, including 5 with laparoscopic Nissen fundoplication), and 31 in the intraoperative-esophageal-manometry group (INF, 13 with laparoscopic Nissen fundoplication). There were no operation-related deaths. Operation-related complications occurred in five patients within 1 month after operation: In CNF, two patients suffered from dysphagia and one from regurgitation; in FNF, one patient had slight dysphagia and two had regurgitation; in INF, there was no one who complained about dysphagia or regurgitation, but pneumothorax occurred in one case. After more than 2 years of follow-up, two patients, in CNF, suffered from severe dysphagia, one recurred and two with abnormal 24 h pH monitoring. In FNF, one patient had dysphagia, one recurred and three had abnormal 24 h pH monitoring; in INF, two patients had acid reflux on 24 h pH monitoring. The postoperative lower esophageal sphincter pressure was in the normal range in 30 of 31 patients (96.5%). The normal rate of postoperative tests in CNF, FNF and INF were 81.5%, 86.4% and 93.5%, respectively. Both the Nissen fundoplication and the floppy Nissen fundoplication are effective approaches to treat patients with sliding hiatal hernia. Intraoperative manometry is useful in standardizing the tightness of the wrap in floppy Nissen fundoplication and may contribute to reducing or avoiding the occurence of postoperative complications.

Bifunctional compounds for targeted hepatic gene delivery

A series of bifunctional compounds with galactosyl residues as targeting ligand for asialoglycoprotein receptors on hepatocytes and various dendrimers as the DNA-binding domain was synthesized. When mixed with plasmid DNA, these compounds self assembled into particles that exhibited high transfection activity both in vitro and in vivo. Optimal activity in liver cells was observed with compounds containing three galactosyl residues and 16 dendrimer arms. These results suggest that domain-based design is an effective strategy for development of a new generation of synthetic gene carriers.

Effect of acute gastric electrical stimulation on the systemic release of hormones and plasma glucose in dogs

This study evaluated the effect of gastric electrical stimulation (GES) with various parameters on plasma concentrations of satiety-related peptides and glucose. GES was performed in nine healthy dogs via electrodes implanted in the middle of the lesser curvature. Four sessions were performed in each animal: control, stimulation with IGS (implantable gastric stimulation for obesity, 0.3 m sec), modified IGS (2 msec), and long pulses (300 msec). Blood samples were collected at 15 and 0 min before the meal and at 15, 30, and 60 min after the meal. GES was initiated 30 min before the first blood sample and maintained throughout collection. Plasma ghrelin, leptin, insulin and glucose were measured. The total AUCs of plasma ghrelin and leptin were not significantly affected by GES. The total AUC of plasma insulin was significantly lower with IGS and long pulse parameters (P < 0.05). The total AUC for plasma glucose was significantly lower in sessions with long pulses and modified IGS parameters (P < 0.05). We conclude that acute GES is able to change the release of some satiety-related peptides. Whether this is associated with the changed eating behavior and weight loss in obese patients needs further investigation.

Prevalence of factor V Leiden and prothrombin G20210A mutations in Chinese patients with deep venous thrombosis and pulmonary embolism

Venous thromboembolism (VTE) is a common vascular disease that results in two major clinical manifestations: deep venous thrombosis (DVT) and pulmonary embolism (PE). Several genetic risk factors, especially factor V Leiden and prothrombin G20210A mutations have been reported to be related to VTE in Caucasians, but the relationship remains controversial in other populations. Thus, the objective of the present study was to compare the frequency of the two mutations and also to investigate whether acquired risk factors other than genetic mutations may play a different role in Chinese VTE patients. Thirty-five patients were diagnosed with DVT concomitant PE, 178 patients with DVT, 54 patients with PE and 102 control subjects were recruited. The mutation was determined by the polymerase chain reaction-restriction fragment length polymorphism method. Of all subjects, none was a carrier of factor V Leiden or prothrombin G20210A mutations. The frequency of surgery was significantly higher in the PE group than that in other groups. There was no significant difference among the three groups in other known risk factors. The data presented here indicate that factor V Leiden and prothrombin G20210A mutations are very rare in the Chinese population, and the genetic risk profile of VTE in the Chinese population is different from that in Caucasians.

Subcellular fractionation and molecular characterization of the pellicle and plasmalemma of Neospora caninum

A characteristic structural feature of Toxoplasma gondii and Neospora caninum is the presence of a triple-membrane pellicle, on the zoite stages of their complex life-cycle. Here we report the results of electron microscopic studies which show that the pellicle is made of a typical plasmalemma covered on its cytoplasmic side by a system of flattened vesicles named the inner membrane complex. Using methods described previously for the purification of pellicle and plasmalemma fractions from T. gondii, we have evaluated the same methodology for the preparation of pellicles and plasmalemma from N. caninum. The approach used involved subcellular fractionation and sucrose gradient centrifugation to prepare fractions containing pellicles. Plasmalemma was prepared by extraction of this fraction with a high salt glycerol treatment. Fractions containing membrane structures were identified by electron microscopy, and the proteins and antigens present in them were subsequently studied by SDS-PAGE and Western blotting. Electron microscopy of the pellicle fractions of N. caninum demonstrated preservation of the triple-membrane structure which is identical to that found in T. gondii. SDS-PAGE of the pellicle fractions revealed it contained several major proteins. Analyses revealed that the plasmalemma of N. caninum contained 2 abundant proteins in addition to other much lower abundance antigens detectable by monoclonal antibodies. These studies therefore report, for the first time, a detailed molecular characterization of the pellicle and plasmalemma of N. caninum.

Dynamic changes in orbitofrontal neuronal activity in rats during opiate administration and withdrawal

The orbitofrontal cortex is involved in the reinforcing effects of drugs of abuse. However, how the dynamic activity in OFC changes during opiate administration and withdrawal period has not been investigated. We first tested the effects of opiates and drug craving with the conditioned place preference paradigm, using manganese-enhanced magnetic resonance imaging and traditional electroencephalograph recording techniques in rats. T1-weighted 2D MRI (4.7 T) was used after unilateral injection of MnCl(2) (200 nL, 80 mM) into the right orbitofrontal cortex. The manganese-enhanced magnetic resonance imaging data suggested that the OFC activity decreased during the opiate administration period but recovered increasingly during the withdrawal period. Also, we found decreases and increases in gamma-band (20-100 Hz) activity during the opiate administration and withdrawal period, respectively. Our results showed that orbitofrontal cortex activity decreased during morphine administration and then went up progressively over several days during withdrawal. The time course of the recovery of orbitofrontal activity from inhibition during the withdrawal period may be related to the experience of drug craving.

Gastric Electrical Stimulation (GES) with Parameters for Morbid Obesity Elevates Lower Esophageal Sphincter (LES) Pressure in Conscious Dogs

BACKGROUND

Treatment of obese patients with the implantable gastric stimulator (IGS) was reported to improve reflux symptoms, independent of weight loss. We evaluated the effect of gastric electrical stimulation on LES pressure in conscious dogs.

METHODS

8 dogs were studied. GES with three sets of parameters was randomly applied via a pair of electrodes implanted in the fundus on separate days. Manometry was performed with a Dent-Sleeve catheter passed through an esophageal canula. The involvement of the cholinergic pathway was also tested.

RESULTS

1) Stimulation with IGS parameters (40 Hz, 0.3 ms, 6 mA, 2 seconds on and 3 seconds off) induced a significant increase in LES pressure (29.9+/-4.8 mmHg), and remained significantly higher during the post-stimulation period (32.6+/-9.6 mmHg) compared to baseline (24.5+/-3.8 mmHg), P<0.01.2) Long pulse stimulation (10 cpm, 300 ms, 8 mA) tended to increase LES pressure from 29.6+/-4.4 mmHg of baseline to 31.8+/-4.9 mmHg with stimulation, to 32.6+/-4.5 mmHg after discontinuation (P=0.08); 3) Modified IGS parameters (40 Hz, 2 ms, 6 mA, 2 seconds on and 3 seconds off) did not induce a significant change in LES pressure during and after stimulation. 4) Effect of stimulation with IGS parameters on LES pressure was blocked by intravenous atropine.

CONCLUSION

GES with IGS parameters significantly increases LES pressure in conscious dogs. This effect is mediated by the cholinergic pathway. These results suggest that GES may be able to benefit GERD patients and obese patients with GERD.

Plant growth: the translational connection

The TOR (target of rapamycin) pathway is a phylogenetically conserved transduction system in eukaryotes linking the energy status of the cell to the protein synthesis apparatus and to cell growth. The TOR protein is specifically inhibited by a rapamycin–FKBP12 complex (where FKBP stands for FK506-binding protein) in yeast and animal cells. Whereas plants appear insensitive to rapamycin, Arabidopsis thaliana harbours a single TOR gene, which is essential for embryonic development. It was found that the product of this gene was capable of binding to rapamycin and yeast FKBP12. In-frame fusion with a GUS reporter gene shows that the TOR protein is produced essentially in proliferating zones, whereas the TOR mRNA can be detected in all organs suggesting a translational regulation of TOR. Phenotypic analysis of Arabidopsis TOR mutants indicates that the plant TOR pathway fulfils the same role in controlling cell growth as its other eukaryotic counterparts.

Microencapsulation and culture in vitro of rat pinealocytes

BACKGROUND

Melatonin is a powerful anti-aging reagent for scavenging free radicals. However, the effect of exogenous melatonin on age-dependent diseases is uncertain. Immune rejection has limited xenotransplantation or allotransplantation of the pineal gland. The aim of this study was to assess cell viability and the function of rat pinealocytes encapsulated in APA capsules and offer experimental suggestions for pineal microencapsulation grafting to resist aging.

METHODS

The pineal glands of neonatal rats were removed. Pinealocytes were isolated and encapsulated in APA microencapsulation and cultured. Morphological appearance of the microencapsulation was observed. Trypan blue staining and 5-HT immunocytochemical assay were used to detect cell viability and identify pinealocytes. The expression of AA-NAT mRNA was confirmed by RT-PCR. Melatonin release was measured and compared by HPLC.

RESULTS

Both control and encapsulated pinealocyte cultures survived well. The majority of the encapsulated pinealocytes as well as unencapsulated cells remained 5-HT positive. No significant difference in melatonin secretion and the expression level of AA-NAT mRNA between encapsulated and unencapsulated pinealocytes was found.

CONCLUSIONS

Pinealocytes survive and remain functionally competent in vitro at least 2 weeks after microencapsulation.

Effect of lipase inhibition on gastric emptying of, and the glycemic and incretin responses to, an oil/aqueous drink in type 2 diabetes mellitus

This study examined the effects of the lipase inhibitor, orlistat, on gastric emptying of, and the glycemic and incretin hormone responses to, a drink containing oil and glucose components in patients with type 2 diabetes. Seven patients (aged 58 +/- 5 yr), managed by diet alone, consumed 60 ml olive oil (labeled with 20 MBq (99m)Tc-V-thiocyanate) and 300 ml water containing 75 g glucose (labeled with 6 MBq (67)Ga-EDTA), on two occasions, with and without 120 mg orlistat, positioned in the left lateral decubitus position with their back against a gamma camera. Venous blood samples, for measurement of blood glucose and plasma insulin, glucagon-like peptide-1 and glucose-dependent insulintropic polypeptide were obtained immediately before, and after, the drink. Gastric emptying of both oil (P < 0.001) and glucose (P < 0.0005) was faster after orlistat compared with control. Postprandial blood glucose (P < 0.001) and plasma insulin (P < 0.05) were substantially greater after orlistat compared with control. In contrast, plasma glucagon-like peptide-1 (P < 0.005) and glucose-dependent insulintropic polypeptide (P < 0.05) were less after orlistat. In conclusion, inhibition of fat digestion, by orlistat, may exacerbate postprandial glycemia, as a result of more rapid gastric emptying and a diminished incretin response.

Enzymatic hydrolysis of waste sugarcane bagasse in water media

Enzymatic hydrolysis of natural cellulose such as sugarcane bagasse is usually carried out in a buffer medium. In this paper, the enzymatic hydrolysis of a waste sugarcane bagasse in water media was carried out.The bagasse was pre-treated with heating explosion and pure (ion exchange), reverse-osmosis and tap water media were used in place of a buffer solution in the hydrolysis process. The yields for reducing sugars and the changes in solution pH and electric conductivity during the hydrolysis under various conditions were studied. The results were also compared with those obtained in buffer solutions. Similar levels of sugar yields were obtained in water and buffer solution media. The pH of the hydrolyzate was in the range of 4.5 - 5.0, which coincided with the optimum pH for the enzyme reaction. It was considered that the enzyme and the substrate formed a transitional complex in the hydrolysis process. The transitional complex provided the buffering capacity pH 5. The results indicate of the hydrolyzate solution at around that industrialization of the enzymatic hydrolysis in a water medium is feasible.

[Technical causes of false and inferior species appearing in Chinese medicinal materials markets]

The result indicated that technical causes of false and inferior appearing in the Chinese medicinal materials markets consisted of two respects essentially. First, the men who violated the law and committed a crime used certain weak link existing in quantity analysis of country's medicinal standard. Second, it is difficult that basic units managing and using drug implement effective technical supervision.

Hyper immunoglobulin E response in mice with monoclonal populations of B and T lymphocytes

A key event in the pathogenesis of allergies is the production of antibodies of the immunoglobulin (Ig)E class. In normal individuals the levels of IgE are tightly regulated, as illustrated by the low serum IgE concentration. In addition, multiple immunizations are usually required to generate detectable IgE responses in normal experimental animals. To define the parameters that regulate IgE production in vivo, we generated mice bearing monoclonal populations of B and T lymphocytes specific for influenza virus hemagglutinin (HA) and chicken ovalbumin (OVA), respectively. A single immunization of the monoclonal mice with the cross-linked OVA-HA antigen led to serum IgE levels that reached 30-200 microg/ml. This unusually high IgE response was prevented by the infusion of regulatory alpha/beta CD4(+) T cells belonging to both CD25(+) and CD25(-) subpopulations. The regulation by the infused T cells impeded the development of fully competent OVA-specific effector/memory Th2 lymphocytes without inhibiting the initial proliferative response of T cells or promoting activation-induced cell death. Our results indicate that hyper IgE responses do not occur in normal individuals due to the presence of regulatory T cells, and imply that the induction of regulatory CD4(+) T cells could be used for the prevention of atopy.

[Color measurements of 1,944 anterior teeth of people in southwest of China-discreption]

OBJECTIVE

To study the color distribution space of natural anterior tooth crowns of people in southwest China and effects of sex and age on tooth color.

METHODS

The subjects studied consisted of 162 persons aged from 20 to 73 years and born in southwest China. A total of 1,944 healthy anterior teeth were measured in-vivo with a fiber-optical spectrophotometry system.

RESULTS

Statistical analysis showed that the color distribution space of Chinese tooth crowns was wide. The value of L* varied from 42.383 to 67.428, the value of a* from -4.750 to 1.371, the value of b* from 1.88 to 20.268, the value of x from 0.298 to 0.393, the value of y from 0.332 to 0.392, and the value of Y from 19.383 to 34.025. The color difference between the upper and lower limits of 95% confidence was 31.667 CIE delta E units. The difference in colorimetry between male and female was not significant. The results showed that in three sections of teeth (incisal, middle and cervical) the values of L* and a* were negatively related to age (r < 0, P < 0.01); the value of b* was positively related to age just at the cervical and middle sites of teeth (r > 0, P < 0.01) and was not related to age at the incisal site of teeth (P > 0.05).

CONCLUSION

The color distribution space of Chinese anterior tooth crowns is wide. There is no difference in the anterior tooth color between male and female subjects. The values of L* and a* and negatively related to age except the value of b*.

[A study on the resistance of Staphylococcus aureus and the mechanisms of its resistance to fluoroquinolone]

OBJECTIVE

To investigate the resistance of Staphylococcus aureus(SA) and the mechanisms of its resistance to fluoroquinolones (FQ).

METHODS

The susceptibility of SA (200 strains) to 12 antibiotics was detected by disc diffusion, The minimal inhibitory concentrations (MICs) of 52 strains to three FQ were determined by agar dilution method. 52 strains resistant to ciprofloxacin (MIC> or =4 mg/L) were studied for the presence of point mutations in the gyrA gene and grlA gene by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) method and for the expression of norA gene by reserpine reverse test respectively.

RESULTS

34% of the strains were resistant to oxacillin(methicillin resistant Staphylococcus aureus, MRSA) and other antimicrobials as well, but no vancomycin resistant strain was found. The resistance rate of MRSA to ciprofloxacin was 79.4% and cross-resistance existed. It was found that 42 strains (80.8%) had a mutation at gyrA codon 84 (TCA-->TTA or GCA). Mutations at grlA codon 80 (TCC-->TAC or TTC) and codon 84 (GAA-->AAA)were observed in 10 (19.2%) and 14 strains(26.9%) respectively.Strains containing mutations in gyrA or both gyrA and grlA gene showed a higher level of ciprofloxacin resistance than those with alternation in grlA gene but with wild type gyrA or non-gyrA mutants (P < 0.01). Decreased MICs to ciprofloxacin, norfloxacin and levofloxacin in reserpine reverse test indicated the presence of norA phenotype.

CONCLUSIONS

It is clear that emergence of resistant SA strains will continue to be a problem, especially in MRSA which was resistant to most of the antibiotics. Fluoroquinolones are not the choice for MRSA now. The resistance to fluoroquinolones in clinical isolates of SA are due to the mutations of the gyrA and grlA gene encoding the target enzyme of fluoroquinolones and cell membrane resistance. Mutations of grlA gene may differ in different districts.

Singularities in the Boussinesq equation and in the generalized Korteweg-de Vries equation

In this paper, two kinds of analytic singular solutions (finite-time and infinite-time singular solutions) of two classical wave equations (the Boussinesq equation and a generalized Korteweg-de Vries equation) are obtained by means of the improved homogeneous balance method and a nonlinear transformation. The solutions show that special singular wave patterns exist in the classical models of shallow water wave problem.

The sequence of the human genome

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.

The influences of NO and Ach on cGMP levels in two patient populations

Pulmonary hypertension following cardiac surgery is an important factor affecting postoperative mortality, and its mechanism has not been thoroughly clarified. Cardiopulmonary bypass (CPB) can destroy pulmonary endothelium and aggravate pulmonary hypertension. This study is designed to investigate the impacts of CPB on vascular endothelium-dependent relaxation, and the relations of CPB to pulmonary hypertension. Forty patients undergoing valve surgery were involved. According to their preoperative pulmonary arterial pressure (PAP), these patients were divided into pulmonary hypertension group (H group) and normal group (N group). The concentrations of cyclic guanosine monophosphate (cGMP) were measured at baseline conditions, after acetylcholine (Ach) injection, and during nitric oxide (NO) inhalation. Samples were taken before sternotomy and after weaning from CPB, 4 and 12 hours post-CPB. At baseline, the level of cGMP in the H group was lower than that of the N group by 33.9% before CPB. After initiating the CPB, although the level of cGMP continuously decreased in both groups until weaning from CPB (the N group decreased 33.3%, and the H group decreased 59%). At that point cGMP was higher in N group than in the H group (p < .01). The level of cGMP of both groups tended to recover 4 hours after CPB, but only the N group returned to baseline 12 hours after CPB. After injection of Ach, the level of cGMP of both groups followed the same change as in the baseline, except with different numeric value. The level of cGMP in N group rose ranging from 160.0-197.3%, while it rose ranging from 87.7-168.1% in H group. The levels of cGMP were higher in N group than those in H group at all times following injection of Ach (61.4, 173.3, 202.7, and 188.0%) (p < .01). After inhalation of NO, the level of cGMP of both groups followed the same change as the baseline. The level of cGMP in N group rose ranging from 194.8-320.5%. Although the levels of cGMP were higher in N group than those in H group (6.9, 25.3, 23.3, and 16.6%), significant differences were achieved at the 4 and 12 hour post-CPB periods (p < .05 or p < .01, respectively). It was concluded that the injury of vascular endothelial function caused by CPB was more critical in pulmonary hypertension patients.

A method for removal of CO from exhaust gas using pulsed corona discharge

An experimental study of the oxidation of CO in exhaust gas from a motorcycle has been carried out using plasma chemical reactions in a pulsed corona discharge. In the process, some main parameters, such as the initial CO concentration, amplitude and frequency of pulses, residence time, reactor volume, and relative humidity (RH), as well as their effects on CO removal characteristics, were investigated. O3, which is beneficial to reducing CO, was produced during CO removal. When the exhaust gas was at ambient temperature, more than 80% CO removal efficiency was realized at an initial concentration of 288 ppm in a suitable range of the parameters.

The Drosophila Lissencephaly1 (DLis1) gene is required for nuclear migration

Nuclear movement is critical for several developmental processes in eukaryotes. Drosophila oogenesis provides a paradigmatic example in which localization of the nucleus generates a source of cellular asymmetry that is used in patterning both the anterior-posterior and the dorsal-ventral axes of the oocyte. In this study we show that mutations in the Drosophila Lissencephaly1 (DLis1) gene result in partial ventralization of the eggshell. DLis1 mutations affect the localization of gurken mRNA and protein in the oocyte. These defects are correlated with incorrect positioning of the oocyte nucleus, suggesting that DLis1 is required for nuclear migration. DLis1 shows significant sequence conservation across the evolutionary spectrum. Fungal cognates of DLis1 are involved in nuclear migration while homologs in humans and mice are implicated in neuronal migration. DLis1 shows genetic interactions with the Glued and Dynein heavy chain subunits of the dynein/dynactin complex, supporting the idea that the Lis1 family of proteins plays a role in microtubule motor-based nuclear motility.

Functional antagonism between Msx2 and CCAAT/enhancer-binding protein alpha in regulating the mouse amelogenin gene expression is mediated by protein-protein interaction

Ameloblast-specific amelogenin gene expression is spatiotemporally regulated during tooth development. In a previous study, the CCAAT/enhancer-binding protein alpha (C/EBPalpha) was identified as a transcriptional activator of the mouse amelogenin gene in a cell type-specific manner. Here, Msx2 is shown to repress the promoter activity of amelogenin-promoter reporter constructs independent of its intrinsic DNA binding activity. In transient cotransfection assays, Msx2 and C/EBPalpha antagonize each other in regulating the expression of the mouse amelogenin gene. Electrophoresis mobility shift assays demonstrate that Msx2 interferes with the binding of C/EBPalpha to its cognate site in the mouse amelogenin minimal promoter, although Msx2 itself does not bind to the same promoter fragment. Protein-protein interaction between Msx2 and C/EBPalpha is identified with co-immunoprecipitation analyses. Functional antagonism between Msx2 and C/EBPalpha is also observed on the stably transfected 2.2-kilobase mouse amelogenin promoter in ameloblast-like LS8 cells. Furthermore, the carboxyl-terminal residues 183-267 of Msx2 are required for protein-protein interaction, whereas the amino-terminal residues 2-97 of Msx2 play a less critical role. Among three family members tested (C/EBPalpha, -beta, and -gamma), Msx2 preferentially interacts with C/EBPalpha. Taken together, these data indicate that protein-protein interaction rather than competition for overlapping binding sites results in the functional antagonism between Msx2 and C/EBPalpha in regulating the mouse amelogenin gene expression.

The genome sequence of Drosophila melanogaster

The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the approximately 120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes approximately 13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.

[Clinical study on the orthodontic treatment of deep overbite with bite plane]

Fifteen cases of patients with incisal Angel's Class II obserbite were orthodontically treated with bite plane and analysed with cephalometric radiograph. The results showed that bite plane can correct deep overbite rapidly (within 6 months) and effectively. The mechanism of bite plane was to raise the posterior teeth (1.1 mm) and to lower the anterior teeth (0.8 mm).

[The second phase clinical observation of anti-radiation effect by superoxide dismutase]

Multiple center randomized controlled double blind clinical trait was conducted to evaluate the anti-radiotherapy effect by SOD (produced by Hunan Biochemical Work) in 159 patients. Injection of 4000U SOD immediately after receiving radiotherapy significantly reduced the occurrence rate of skin, oral mucosal, pelvic visceral and systematic adverse reaction, only the reduction of leukopenia did not reach the statistical significant level. No adverse effect of SOD injection was observed. The results suggest that SOD is a safe and effective agent to attenuate the radiotherapy reactions.

[Effect of fusheng powder on neuropeptides in brains of rats with hyperlipidemia after cerebral ischemia and reperfusion]

OBJECTIVE

To observe the changes of some neuropeptides and the effect of Fusheng powder (FSP) on neuropeptides in rat's brains in a stable cerebral ischemia and reperfusion (I/L) model.

METHODS

The models of rat's brain injured were established by repeated cerebral I/R in rats with hyperlipidemia. Radioimmunoassay (RIA) was performed to determine the level of neuropeptides.

RESULTS

After 1 day of I/R, compared with the control group, the contents of endothelin-1 (ET-1), calcitonin gene related peptide (CGRP) and neuropeptide Y (NPY) in the model animals were significantly increased by 24.3%, 33.7% and 51.86% respectively, while the level of somatostatin (SS) decreased by 37.86% (all P < 0.01). Meanwhile after FSP treatment, the contents of neuropeptides were alleviated respectively (P < 0.05, P < 0.01). Apart from the ET, the releases of CGRP, NPY and SS were all recovered in different degree after 7 days of I/R.

CONCLUSIONS

There were obvious imbalance of neuropeptides in rat's brains after cerebral I/R and the FSP might antagonize ischemic injury of brain through modulating neuropeptides, which may be one of the therapeutical mechanism in treating cerebral vascular diseases with FSP.

Identification of mouse CPX-1, a novel member of the metallocarboxypeptidase gene family with highest similarity to CPX-2

The recent finding that Cpe(fat)/Cpe(fat) mice, which lack carboxypeptidase E (CPE) activity because of a point mutation, are still capable of a reduced amount of neuroendocrine peptide processing suggested that additional carboxypeptidases (CPs) participate in this processing reaction. Searches for novel members of the CPE gene family led to the discovery of CPD, CPZ, AEBP1, and CPX-2. In the present report, we describe mouse CPX-1, another novel member of this gene family. Like AEBP1 and CPX-2, CPX-1 contains an N-terminal region of 160 amino acids with sequence similarity to the discoidin domain of a variety of proteins. The 410-residue CP-like domain of CPX-1 has 54% to 62% amino acid sequence identity with AEBP1 and CPX-2 and 33% to 49% amino acid identity with other members of the CPE subfamily. However, several active-site residues that are important for catalytic activity of other CPs are not conserved in CPX-1. Furthermore, CPX-1 expressed in either the baculovirus system or the mouse AtT-20 cell line does not cleave standard CP substrates. Northern blot analysis showed the highest levels of CPX-1 mRNA in testis and spleen and lower levels in salivary gland, brain, heart, lung, and kidney. In situ hybridization of CPX-1 mRNA in embryonic and fetal mouse tissue showed expression throughout the head and thorax, with abundance in primordial cartilage and skeletal structures. In the head, high levels of CPX-1 mRNA were associated with the nasal mesenchyme, primordial cartilage structures in the ear, and the meninges. In the thorax, CPX-1 mRNA was expressed in multiple developing skeletal structures, including chondrocytes and perichondrial cells of the rib, vertebral, and long-bone primordia. Taken together, these findings suggest that it is unlikely that CPX-1 functions in the processing of neuroendocrine peptides. Instead, CPX-1 may have a role in development, possibly mediating cell interactions via its discoidin domain.

Identification of mouse CPX-2, a novel member of the metallocarboxypeptidase gene family: cDNA cloning, mRNA distribution, and protein expression and characterization

A novel member of the metallocarboxypeptidase gene family was identified from its homology with carboxypeptidase E and has been designated CPX-2. The cDNA of 2500 nucleotides encodes a protein of 764 amino acids that contains an N-terminal signal peptide-like sequence, a 158-residue discoidin domain, and a 400-residue carboxypeptidase domain. The 400-residue metallocarboxypeptidase domain has 59% amino acid identity with a protein designated AEBP-1; 44% to 46% identity with carboxypeptidases E, N, and Z; and lower homology with other members of the metallocarboxypeptidase gene family. The discoidin domain of CPX-2 has 22% amino acid identity with the carbohydrate-binding domain of discoideum-I, 29% to 34% identity with the phospholipid-binding domain of human factors V and VIII, and 59% identity with the discoidin-like domain on AEBP-1. CPX-2 is missing several of the predicted active-site residues that are conserved in most other members of the metallocarboxypeptidase gene family and which are thought to be required for enzyme activity. Expression of CPX-2 using the baculovirus system produced several forms of protein, from 80 to 105 kDa, but no detectable activity toward a variety of carboxypeptidase substrates. A shorter 50-kDa form of CPX-2, which contains the carboxypeptidase domain but not the discoidin domain, was also inactive when expressed in the baculovirus system. CPX-2 is able to bind to Sepharose-Arg; this binding is blocked by 10 mM Arg. Northern blot analysis showed CPX-2 mRNA in mouse brain, liver, kidney, and lung. In situ hybridization analysis of brain revealed a broad distribution. Areas that are enriched in CPX-2 include the hippocampus, cerebral cortex, median eminence, and choroid plexus. Taken together, these data suggest a widespread function for CPX-2, possibly as a binding protein rather than an active carboxypeptidase.

[Effect of Fusheng powder on activity of vascular endothelial cells and its adhesion to polymorphonuclear neutrophils]

OBJECTIVE

To explore the effect of Fusheng powder on the adhesion of polymorphonuclear neutrophils (PMN) in human peripheral blood to vascular endothelial cells (VEC).

METHODS

Using cultured human umbilical vein cells as target cells, while being incubated with high glucose (HG, 30 mmol/L), high-lipid (HL, 20%), tumor necrosis factor-alpha (TNF-alpha, 10%) and hypoxia (95% N2, 5% CO2, 37 degrees C, 30 min, and then in the air 30 min) for 24 h, respectively, the activity of VEC and the adhesive effect of PMN to VEC were surveyed.

RESULTS

It revealed that HG, HL, TNF-alpha and hypoxia could enhance obviously the adhesion of PMN to VEC, the cell attachment rate in normal control, HG group, TNF-alpha, hypoxia and HL after 30 minutes contact were 100%, 129.6%, 136.7%, 151.4% and 167.7% (all P < 0.01, compared with control group) respectively, but high and low dosage of the Fusheng powder could significantly inhibit the adhesion of PMN to VEC.

CONCLUSIONS

HG, HL, TNF-alpha and hypoxia could all activate EC respectively and enhance the adhesion of PMN to VEC, but the Fusheng powder could protect VEC and partly block the effect of this adhesion. However, the effects of Fusheng powder on anti-adhesion are of great importance in clinical cardiovascular and cerebral vascular diseases.

[Total body irradiation etoposide followed by autologous hematopoietic stem cell transplantion for non-Hodgkin's lymphoma]

OBJECTIVE

To evaluate the therapeutic effectiveness and safety of total body irradiation(TBI) and Etoposide(Vp-16) as a preparative regimen for autologous hematopoietic stem cell transplantation(AHSCT) with non-Hodgkin's lymphoma(NHL).

METHODS

Twenty-four patients with intermediate and high grade NHL underwent AHSCT. They achieved complete remission (CR) or partial remission (PR) after induction chemoradiotherapy. Twenty-three patients had first CR or PR, and one third CR. Ten patients underwent autologous bone marrow transplantation (ABMT) and 14 autologous peripheral blood stem cell transplantation (APBSCT). The preparative regimen was TBI 800(700-850) cGy/Vp-16 757(323-1140) mg/m2.

RESULTS

At a median follow-up of 22.5(2-92) months, the one-year disease free survival(DFS) was 86.7% (13/15), 3-year, 5-year and 7-year DFS were 80.0% (12/15) in patients with CR before AHSCT. The DFS was 66.7% (4/6) in patients with PR before AHSCT. The patients who had relapsed before AHSCT(3 cases) did not reach DFS. The hematopoietic function recovery was rapid in APBSCT than ABMT.

CONCLUSION

The clinical results of AHSCT for intermediate and high grade NHL who achieved CR or PR after induction therapy are satisfactory. The TBI/Etoposide is an effective and safe preparative regimen for AHSCT in NHL patients.

Presence, isolation and characterization of yolk DNA from chicken eggs

Yolk DNA was detected with immunocytochemistry in fertilized chicken eggs. Yolk spheres were purifield with Ficoll-400 density gradient centrifugation, followed by extraction of DNA therein. Yolk DNA is sensitive to various restriction endonucleases. but shows no obvious bands, demonstrating its sequence heterogeneity. There is only a little, if any, methylated CpG in yolk DNA. judgmg from MspI and HpII digestion. Southern blot indicated that the sequence of yolk DNA accounts for a small portion of that of genomic DNA. Its uniqueness suggests that yolk DNA may play a crucial role in early development of chickens.

Mechanistic studies of the biosynthesis of paratose: purification and characterization of CDP-paratose synthase

The 3,6-dideoxyhexoses can be found in the cell wall lipopolysaccharide of Gram-negative bacteria, where they have been shown to be the dominant antigenic determinants. All naturally occurring 3,6-dideoxyhexoses, with colitose as the only exception, are biosynthesized via a complex pathway that begins with CDP-d-glucose. Included in this pathway is CDP-paratose synthase, an essential enzyme in the formation of the 3,6-dideoxy sugars, CDP-paratose and CDP-tyvelose. Recently, the gene encoding CDP-paratose synthase in Salmonella typhi, rfbS, has been identified and sequenced [Verma, N., and Reeves, P. (1989) J. Bacteriol. 171, 5694-5701]. On the basis of this information, we have amplified the rfbS gene by polymerase chain reaction (PCR) from S. typhi and cloned this gene into a pET-24(+) vector. Expression and purification of CDP-paratose synthase have allowed us to fully characterize the catalytic properties of this enzyme, which is a homodimeric protein with a preference for NADPH over NADH. It catalyzes the stereospecific hydride transfer of the pro-S hydrogen from the C-4' position of the reduced coenzyme to C-4 of the substrate, CDP-3,6-dideoxy-D-glycero-D-glycero-4-hexulose. The overall equilibrium of this catalysis greatly favors the formation of the reduced sugar product and the oxidized coenzyme. Interestingly, this enzyme also exhibits a high affinity for NADPH with a much smaller dissociation constant (Kia) of 0.005 +/- 0.002 microM compared to the Km of 26 +/- 8 microM for NADPH. While this unusual property complicated the interpretation of the kinetic data, the kinetic mechanism of CDP-paratose synthase as explored by the combination of bisubstrate kinetic analysis, product inhibition studies, and dead-end competitive inhibition studies is most consistent with a Theorell-Chance mechanism. The present study on CDP-paratose synthase, a likely new member of the short-chain dehydrogenase family, represents the first detailed characterization of this type of ketohexose reductase, many of which may share similar properties with CDP-paratose synthase.

Cloning, sequence analysis, and distribution of rat metallocarboxypeptidase Z

A cDNA encoding human carboxypeptidase Z (CPZ), a novel metallocarboxypeptidase, was recently cloned (Song and Fricker, J. Biol. Chem., 272, 1054, 1997). In the present study, a cDNA encoding the rat homolog of CPZ was identified. As with the human form, rat CPZ contains an N-terminal domain of 120 amino acids that has 20% to 30% amino acid identity with the "frizzled" domain found on proteins that interact with Wnt, a protein involved in tissue polarity in early embryogenesis. Sequence analysis showed rat and human CPZ to be highly conserved within the frizzled domain (77% amino acid identity), the carboxypeptidase domain (91%), and the C-terminal 28 residues (78%). The entire rat CPZ protein has high sequence similarity with human CPZ (81% amino acid identity), moderate sequence similarity to human carboxypeptidase N (45%), human carboxypeptidase E (41%), and human carboxypeptidase M (33%), and less sequence similarity with other metallocarboxypeptidases. Northern blot analysis showed rat CPZ mRNA to be abundant in the placenta, with low to moderate levels in the brain, lung, thymus, and kidney. The BRL3A rat liver cell line and the PC12 rat adrenal cell line express high levels of CPZ mRNA. In situ hybridization analysis indicated that CPZ is expressed only in specific cell types. For example, in the brain, CPZ mRNA is present in leptomeningeal cells, but not in the majority of other cell types. This distribution in leptomeningeal cells is shared by AEBP1, a recently reported member of the metallocarboxypeptidase gene family. However, the distribution of CPZ and AEBP1 differ in pituitary and thyroid. Taken together, these studies suggest that CPZ functions in a range of cell types.

[Effects of orthodontic treatment on the shape of upper dental arch of patients after surgical operation of cleft lip and palate]

Occlusal casts were measured and analysed in the following groups: orthodontic group(9 subjects treated orthodonticly after surgical operation of the cleft lip and palate), untreated group (10 subjects untreated orthodonticly after surgical operation), normal group(10 young subjects with normal occlusion). The results were that the upper dental arch length and width increased evidently (P < 0.01) in the orthodontic group and almost returned to normal; in contrast, the upper dental arch length and width were inhibited in the untreated group; there were significant differences among the normal occlusion group, the orthodontic group, and untreated group (P < 0.01). The results suggest that during the period of growth and development, the shape of the upper dental arch of the patients can be evidently improved by the orthodontic treatment after the surgical operation of cleft lip and palate.