The effect of glutathione biosynthesis of Streptococcus thermophilus ST-1 on cocultured Lactobacillus delbrueckii ssp. bulgaricus ATCC11842

Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus are the main species used for yogurt preparation. Glutathione (GSH) can be synthesized by S. thermophilus and plays a crucial role in combating environmental stress. However, the effect of GSH biosynthesis by S. thermophilus on cocultured L. delbrueckii ssp. bulgaricus is still unknown. In this study, a mutant S. thermophilus ΔgshF was constructed by deleting the GSH synthase. The wild strain S. thermophilus ST-1 and ΔgshF mutants were cocultured with L. delbrueckii ssp. bulgaricus ATCC11842 by using Transwell chambers (Guangzhou Shuopu Biotechnology Co., Ltd.), respectively. It was proven that the GSH synthesized by S. thermophilus ST-1 could be absorbed and used by L. delbrueckii ssp. bulgaricus ATCC11842, and promote growth ability and stress tolerance of L. delbrueckii ssp. bulgaricus ATCC11842. The biomass of L. delbrueckii ssp. bulgaricus ATCC11842 cocultured with S. thermophilus ST-1 or ΔgshF (adding exogenous GSH) increased by 1.8 and 1.4 times compared with the biomass of L. delbrueckii ssp. bulgaricus ATCC11842 cocultured with S. thermophilus ΔgshF. Meanwhile, after H₂O₂ and low-temperature treatments, the bacterial viability of L. delbrueckii ssp. bulgaricus cocultured with S. thermophilus ΔgshF, with or without GSH, was decreased by 41 and 15% compared with that of L. delbrueckii ssp. bulgaricus cocultured with S. thermophilus ST-1. Furthermore, transcriptome analysis showed that the expression levels of genes involved in purine nucleotide and pyrimidine nucleotide metabolism in L. delbrueckii ssp. bulgaricus ATCC11842 were at least 3 times increased when cocultured with S. thermophilus (fold change > 3.0). Moreover, compared with the mutant strain ΔgshF, the wild-type strain ST-1 could shorten the fermented curd time by 5.3 hours during yogurt preparation. These results indicated that the GSH synthesized by S. thermophilus during cocultivation effectively enhanced the activity of L. delbrueckii ssp. bulgaricus and significantly improved the quality of fermented milk.

[Progress in diagnosis and treatment of gastroparesis after colon cancer surgery]

At present, comprehensive treatment dominated by surgical procedures is an important measure for colon cancer to obtain the chance of cure. Surgical intervention, while removing the tumor, carries the risk of postoperative gastroparesis (PG) . Because of the low incidence rate and insignificant early clinical symptoms, early stage PG is often overlooked clinically. However, PG can increase the risk of malnutrition, delay postoperative antitumor treatment, and increase the risk of tumor recurrence and metastasis. This review focuses on the mechanisms, clinical risk factors, preventive measures, and advances in treatment of PG due to colon cancer. Aim to increase the clinician's adequate attention to PG in colon cancer and from a surgical point to reduce the risk of gastroparesis in colon cancer by optimizing the surgical strategy.

[A nationalsurveyandresults analysisof seizure prophylaxis after aneurismal subarachnoid hemorrhage]

Investigate theclinical practice of seizure prophylaxis after aneurysmal subarachnoid hemorrhage in Chinese neurosurgeons.Aquestionnaire for this theme was designed and was sent to respondents through the internet.From July 2021 to October 2021, atotal of forty-three eligible questionnaires were collected. All responders come from affiliated hospitals of medical schools in China. Each of these hospitals admitted more than one hundred patients with aneurysmal subarachnoid hemorrhage per year. Only 9.3% (4/43) of responders disagree with the prophylactic use of anticonvulsants. 86.04% (37/43) of responders perform seizure prophylaxis in clinical practice. Sodium valproate is the most commonly used regimen; 94.59% (35/37) of responders who perform prophylaxis chose this drug. The medication period differs sharply fromlessthan 3 daystolongerthan 14 daysamong different hospitals. The use of EEG was insufficient in Chinese patients. A low seizure rate was reported according to the feedback from Chinese neurosurgeons.In China, seizure prophylaxis after subarachnoid hemorrhage was not yet standardized. Clinicians' mastery of relevant knowledge is still not enough. Carrying out high-quality clinical research can help justify the use of anticonvulsants, which could also positively impact rational drug use.

[Prognostic factors affecting the success of conversion chemotherapy in patients with unresectable liver metastases from initially colorectal cancer]

Objective: To investigate the factors affecting the success of conversion therapy in patients with initially unresectable colorectal cancer liver metastases (CRLM) in order to provide evidence-based medical evidence for formulating individualized treatment strategies for patients. Methods: A retrospective case-control study was used in this study. Clinical data of 232 patients with initially unresectable CRLM receiving first-line systemic treatment in Sun Yat-sen University Cancer Center from January 2013 to January 2020 were collected, including 98 patients of successful conversion and 134 patients of failed conversion as control. Conversion therapy scheme: 38 patients received FOLFOXIRI regimen chemotherapy (irinotecan, oxaliplatin, calcium folinate and fluorouracil), 152 patients received FOLFOX regimen (oxaliplatin, calcium folinate and fluorouracil), 19 patients received FOLRIRI regimen (irinotecan, calcium folinate and fluorouracil), 23 patients received systemic chemotherapy combined with fluorouridine hepatic artery infusion chemotherapy; 168 patients received targeted therapy, including 68 of bevacizumab and 100 of cetuximab. Logistics analysis was used to compare the factors affecting the success of conversion therapy. The Kaplan-Meier method was used to calculate progression-free survival (PFS), and the Log-rank test was used for survival comparison. Results: Among 232 patients, 98 patients had successful conversions and 134 patients had failed conversions with a successful conversion rate of 42.2%, meanwhile 30 patients underwent simple hepatectomy and 68 underwent hepatectomy combined with intraoperative radiofrequency ablation. After first-line chemotherapy, 111 patients (47.8%) were partial remission, 57 patients (24.6%) were stable disease, and 64 patients (27.6%) were progression disease. During the median follow-up of 18.8 (1.0-87.9) months, 148 patients were dead or with tumor progression. The median PFS time of patients with successful conversion was longer than that of patients with failed conversion (31.0 months vs. 9.9 months, P<0.001). Univariate analysis found that the bilobar distribution of liver tumors (P=0.003), elevated baseline carcinoembryonic antigen (CEA) levels (P=0.024), tumor invasion of the portal vein (P=0.001), number of metastatic tumor>8 (P<0.001), non-FOLFOXIRI (P=0.005), and no targeted therapy (P=0.038) were high risk factors for the failed conversion therapy. The results of multivariate logistics analysis indicated that the number of metastatic tumor >8 (OR=2.422, 95%CI: 1.291-4.544, P=0.006), portal vein invasion (OR=2.727, 95%CI: 1.237-4.170, P=0.008) were the independent risk factors for failed conversion therapy, while FOLFOXIRI regimen (OR=0.300, 95%CI: 0.135-0.666, P=0.003) and targeted drugs (OR=0.411, 95%CI: 0.209-0.809, P=0.010) were independent protective factors for successful conversion therapy. Conclusions: The number of metastatic tumor and portal vein invasion are key factors that affect the outcomes of conversion therapy for initially unresectable CRLM. If a patient can tolerate chemotherapy, a combination program of three-drug and targeted therapy is preferred for the active conversion therapy.

Neuroprotective effects of Bcl-2 overexpression on nerve cells of rats with acute cerebral infarction

We aimed to investigate the influence of lentiviral-mediated Bcl-2 overexpression in cerebral tissues of rats with acute cerebral infarction. Forty-five rats were randomly divided into sham, model, and treatment groups. The sham and model groups were administered a control lentiviral vector via the intracranial arteries 10 days before surgery, while the treatment group received lentivirus encoding a Bcl-2 overexpression vector. We induced cerebral artery infarction using a suture-occlusion method and analyzed the cerebral expression levels of apoptosis-related genes (caspase-3, Bax), total cerebral apoptosis, range of cerebral tissue infarction, and changes in nerve cell function after 72 h. The Bcl-2-encoding lentivirus was well expressed in rat cerebral tissues. The treatment group had significantly higher expression levels of Bcl-2 than the other two groups. After cerebral infarction, the model group had significantly increased expression levels of caspase-3 and Bax protein in cerebral tissues than the sham (P < 0.05). Expression of these apoptosis-related proteins in the treatment group was obviously lower than that in the model group (P < 0.05), but significantly higher than in the sham group (P < 0.05). Compared to sham, neuronal apoptosis levels and infarction range of cerebral tissues was increased in the model and treatment groups; however, these values in the treatment group were significantly lower than that in the model group (P < 0.05). Importantly, the treatment group had significantly decreased neurological impairment scores (P < 0.05). In conclusion, Bcl-2 over-expression can decrease neuronal apoptosis in rat cerebral tissue, and thus is neuroprotective after cerebral ischemia.

Deletion mapping of homoeologous group 6-specific wheat expressed sequence tags

To localize wheat (Triticum aestivum L.) ESTs on chromosomes, 882 homoeologous group 6-specific ESTs were identified by physically mapping 7965 singletons from 37 cDNA libraries on 146 chromosome, arm, and sub-arm aneuploid and deletion stocks. The 882 ESTs were physically mapped to 25 regions (bins) flanked by 23 deletion breakpoints. Of the 5154 restriction fragments detected by 882 ESTs, 2043 (loci) were localized to group 6 chromosomes and 806 were mapped on other chromosome groups. The number of loci mapped was greatest on chromosome 6B and least on 6D. The 264 ESTs that detected orthologous loci on all three homoeologs using one restriction enzyme were used to construct a consensus physical map. The physical distribution of ESTs was uneven on chromosomes with a tendency toward higher densities in the distal halves of chromosome arms. About 43% of the wheat group 6 ESTs identified rice homologs upon comparisons of genome sequences. Fifty-eight percent of these ESTs were present on rice chromosome 2 and the remaining were on other rice chromosomes. Even within the group 6 bins, rice chromosomal blocks identified by 1-6 wheat ESTs were homologous to up to 11 rice chromosomes. These rice-block contigs were used to resolve the order of wheat ESTs within each bin.

A 2500-locus bin map of wheat homoeologous group 5 provides insights on gene distribution and colinearity with rice

We constructed high-density deletion bin maps of wheat chromosomes 5A, 5B, and 5D, including 2338 loci mapped with 1052 EST probes and 217 previously mapped loci (total 2555 loci). This information was combined to construct a consensus chromosome bin map of group 5 including 24 bins. A relatively higher number of loci were mapped on chromosome 5B (38%) compared to 5A (34%) and 5D (28%). Differences in the levels of polymorphism among the three chromosomes were partially responsible for these differences. A higher number of duplicated loci was found on chromosome 5B (42%). Three times more loci were mapped on the long arms than on the short arms, and a significantly higher number of probes, loci, and duplicated loci were mapped on the distal halves than on the proximal halves of the chromosome arms. Good overall colinearity was observed among the three homoeologous group 5 chromosomes, except for the previously known 5AL/4AL translocation and a putative small pericentric inversion in chromosome 5A. Statistically significant colinearity was observed between low-copy-number ESTs from wheat homoeologous group 5 and rice chromosomes 12 (88 ESTs), 9 (72 ESTs), and 3 (84 ESTs).

A chromosome bin map of 16,000 expressed sequence tag loci and distribution of genes among the three genomes of polyploid wheat

Because of the huge size of the common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) genome of 17,300 Mb, sequencing and mapping of the expressed portion is a logical first step for gene discovery. Here we report mapping of 7104 expressed sequence tag (EST) unigenes by Southern hybridization into a chromosome bin map using a set of wheat aneuploids and deletion stocks. Each EST detected a mean of 4.8 restriction fragments and 2.8 loci. More loci were mapped in the B genome (5774) than in the A (5173) or D (5146) genomes. The EST density was significantly higher for the D genome than for the A or B. In general, EST density increased relative to the physical distance from the centromere. The majority of EST-dense regions are in the distal parts of chromosomes. Most of the agronomically important genes are located in EST-dense regions. The chromosome bin map of ESTs is a unique resource for SNP analysis, comparative mapping, structural and functional analysis, and polyploid evolution, as well as providing a framework for constructing a sequence-ready, BAC-contig map of the wheat genome.

Characterization of EST-derived microsatellites in the wheat genome and development of eSSR markers

EST-derived microsatellites or simple sequence repeats (eSSR) occur in expressed sequence tags (EST). Here we report characteristics of eSSRs in the wheat genome, construction of consensus chromosome bin maps of SSR-containing ESTs ((SSR)ESTs), and development of eSSR markers for the 21 wheat chromosomes. A Perl script known as MISA was used to identify eSSRs in wheat ESTs available in the database http://wheat.pw.usda.gov/cgi-bin/ace/search/wEST ). Among 492,832 ESTs from the database, 36,520 (7.41%) contained 43,598 eSSRs. This is equivalent to 1 eSSR per 5.46 kb EST sequence. About 60% of the eSSRs were trinucleotides, 19.7% were mononucleotide, 16.7% were dinucleotides, and the remaining approximately 3% consisted of tetra-, penta-, and hexanucleotides. Among the identified eSSRs, (CCG/CGG)n is the most frequent (20.5%) followed by (A/T)n at 13.6%, (AAC/GTT)n at 11.7%, and (AG/CT)n at 8.7%. Among ESTs previously mapped to wheat chromosome bins, a total of 1,010 eSSR loci were derived from 341 (SSR)ESTs. Consensus chromosome bin maps showing the chromosome locations of (SSR)ESTs, SSR sequence motif, and cDNA library were constructed. A chi(2) test indicated that the distribution pattern of eSSR loci was generally similar to that of the original mapped ESTs in the wheat genome. Forty-eight (SSR)ESTs were converted into PCR-based eSSR markers, and 266 eSSR loci were mapped to specific chromosome arms using wheat cytogenetic stocks. The average polymorphism information content (0.45+/-0.16) of eSSR markers was lower than that reported for genomic SSRs (0.54+/-0.19), but higher than RFLPs (0.30+/-0.27). The eSSR markers were transferable among related Triticeae species, Triticum aestivum, T. durum, T. dicoccoides, Hordeum spontaneum, H. vulgare, and Secale cereale. The results confirm the presence of SSRs in expressed genes of wheat and demonstrate another application of ESTs in genomics research. eSSRs will be useful for gene tagging, gene cloning, and comparative genomics studies of cereal crops.

A chromosome bin map of 2148 expressed sequence tag loci of wheat homoeologous group 7

The objectives of this study were to develop a high-density chromosome bin map of homoeologous group 7 in hexaploid wheat (Triticum aestivum L.), to identify gene distribution in these chromosomes, and to perform comparative studies of wheat with rice and barley. We mapped 2148 loci from 919 EST clones onto group 7 chromosomes of wheat. In the majority of cases the numbers of loci were significantly lower in the centromeric regions and tended to increase in the distal regions. The level of duplicated loci in this group was 24% with most of these loci being localized toward the distal regions. One hundred nineteen EST probes that hybridized to three fragments and mapped to the three group 7 chromosomes were designated landmark probes and were used to construct a consensus homoeologous group 7 map. An additional 49 probes that mapped to 7AS, 7DS, and the ancestral translocated segment involving 7BS also were designated landmarks. Landmark probe orders and comparative maps of wheat, rice, and barley were produced on the basis of corresponding rice BAC/PAC and genetic markers that mapped on chromosomes 6 and 8 of rice. Identification of landmark ESTs and development of consensus maps may provide a framework of conserved coding regions predating the evolution of wheat genomes.

Chromosome bin map of expressed sequence tags in homoeologous group 1 of hexaploid wheat and homoeology with rice and Arabidopsis

A total of 944 expressed sequence tags (ESTs) generated 2212 EST loci mapped to homoeologous group 1 chromosomes in hexaploid wheat (Triticum aestivum L.). EST deletion maps and the consensus map of group 1 chromosomes were constructed to show EST distribution. EST loci were unevenly distributed among chromosomes 1A, 1B, and 1D with 660, 826, and 726, respectively. The number of EST loci was greater on the long arms than on the short arms for all three chromosomes. The distribution of ESTs along chromosome arms was nonrandom with EST clusters occurring in the distal regions of short arms and middle regions of long arms. Duplications of group 1 ESTs in other homoeologous groups occurred at a rate of 35.5%. Seventy-five percent of wheat chromosome 1 ESTs had significant matches with rice sequences (E < or = e(-10)), where large regions of conservation occurred between wheat consensus chromosome 1 and rice chromosome 5 and between the proximal portion of the long arm of wheat consensus chromosome 1 and rice chromosome 10. Only 9.5% of group 1 ESTs showed significant matches to Arabidopsis genome sequences. The results presented are useful for gene mapping and evolutionary and comparative genomics of grasses.

Group 3 chromosome bin maps of wheat and their relationship to rice chromosome 1

The focus of this study was to analyze the content, distribution, and comparative genome relationships of 996 chromosome bin-mapped expressed sequence tags (ESTs) accounting for 2266 restriction fragments (loci) on the homoeologous group 3 chromosomes of hexaploid wheat (Triticum aestivum L.). Of these loci, 634, 884, and 748 were mapped on chromosomes 3A, 3B, and 3D, respectively. The individual chromosome bin maps revealed bins with a high density of mapped ESTs in the distal region and bins of low density in the proximal region of the chromosome arms, with the exception of 3DS and 3DL. These distributions were more localized on the higher-resolution group 3 consensus map with intermediate regions of high-mapped-EST density on both chromosome arms. Gene ontology (GO) classification of mapped ESTs was not significantly different for homoeologous group 3 chromosomes compared to the other groups. A combined analysis of the individual bin maps using 537 of the mapped ESTs revealed rearrangements between the group 3 chromosomes. Approximately 232 (44%) of the consensus mapped ESTs matched sequences on rice chromosome 1 and revealed large- and small-scale differences in gene order. Of the group 3 mapped EST unigenes approximately 21 and 32% matched the Arabidopsis coding regions and proteins, respectively, but no chromosome-level gene order conservation was detected.

Development of an expressed sequence tag (EST) resource for wheat (Triticum aestivum L.): EST generation, unigene analysis, probe selection and bioinformatics for a 16,000-locus bin-delineated map

This report describes the rationale, approaches, organization, and resource development leading to a large-scale deletion bin map of the hexaploid (2n = 6x = 42) wheat genome (Triticum aestivum L.). Accompanying reports in this issue detail results from chromosome bin-mapping of expressed sequence tags (ESTs) representing genes onto the seven homoeologous chromosome groups and a global analysis of the entire mapped wheat EST data set. Among the resources developed were the first extensive public wheat EST collection (113,220 ESTs). Described are protocols for sequencing, sequence processing, EST nomenclature, and the assembly of ESTs into contigs. These contigs plus singletons (unassembled ESTs) were used for selection of distinct sequence motif unigenes. Selected ESTs were rearrayed, validated by 5' and 3' sequencing, and amplified for probing a series of wheat aneuploid and deletion stocks. Images and data for all Southern hybridizations were deposited in databases and were used by the coordinators for each of the seven homoeologous chromosome groups to validate the mapping results. Results from this project have established the foundation for future developments in wheat genomics.

Analysis of expressed sequence tag loci on wheat chromosome group 4

A total of 1918 loci, detected by the hybridization of 938 expressed sequence tag unigenes (ESTs) from 26 Triticeae cDNA libraries, were mapped to wheat (Triticum aestivum L.) homoeologous group 4 chromosomes using a set of deletion, ditelosomic, and nulli-tetrasomic lines. The 1918 EST loci were not distributed uniformly among the three group 4 chromosomes; 41, 28, and 31% mapped to chromosomes 4A, 4B, and 4D, respectively. This pattern is in contrast to the cumulative results of EST mapping in all homoeologous groups, as reported elsewhere, that found the highest proportion of loci mapped to the B genome. Sixty-five percent of these 1918 loci mapped to the long arms of homoeologous group 4 chromosomes, while 35% mapped to the short arms. The distal regions of chromosome arms showed higher numbers of loci than the proximal regions, with the exception of 4DL. This study confirmed the complex structure of chromosome 4A that contains two reciprocal translocations and two inversions, previously identified. An additional inversion in the centromeric region of 4A was revealed. A consensus map for homoeologous group 4 was developed from 119 ESTs unique to group 4. Forty-nine percent of these ESTs were found to be homoeologous to sequences on rice chromosome 3, 12% had matches with sequences on other rice chromosomes, and 39% had no matches with rice sequences at all. Limited homology (only 26 of the 119 consensus ESTs) was found between wheat ESTs on homoeologous group 4 and the Arabidopsis genome. Forty-two percent of the homoeologous group 4 ESTs could be classified into functional categories on the basis of blastX searches against all protein databases.

A 2600-locus chromosome bin map of wheat homoeologous group 2 reveals interstitial gene-rich islands and colinearity with rice

The complex hexaploid wheat genome offers many challenges for genomics research. Expressed sequence tags facilitate the analysis of gene-coding regions and provide a rich source of molecular markers for mapping and comparison with model organisms. The objectives of this study were to construct a high-density EST chromosome bin map of wheat homoeologous group 2 chromosomes to determine the distribution of ESTs, construct a consensus map of group 2 ESTs, investigate synteny, examine patterns of duplication, and assess the colinearity with rice of ESTs assigned to the group 2 consensus bin map. A total of 2600 loci generated from 1110 ESTs were mapped to group 2 chromosomes by Southern hybridization onto wheat aneuploid chromosome and deletion stocks. A consensus map was constructed of 552 ESTs mapping to more than one group 2 chromosome. Regions of high gene density in distal bins and low gene density in proximal bins were found. Two interstitial gene-rich islands flanked by relatively gene-poor regions on both the short and long arms and having good synteny with rice were discovered. The map locations of two ESTs indicated the possible presence of a small pericentric inversion on chromosome 2B. Wheat chromosome group 2 was shown to share syntenous blocks with rice chromosomes 4 and 7.

Activity of cytisine and its brominated isosteres on recombinant human alpha7, alpha4beta2 and alpha4beta4 nicotinic acetylcholine receptors

Effects of cytisine (cy), 3-bromocytisine (3-Br-cy), 5-bromocytisine (5-Br-cy) and 3,5-dibromocytisine (3,5-diBr-cy) on human (h) alpha7-, alpha4beta2- and alpha4beta4 nicotinic acetylcholine (nACh) receptors, expressed in Xenopus oocytes and cell lines, have been investigated. Cy and its bromo-isosteres fully inhibited binding of both [alpha-(125)I]bungarotoxin ([alpha-(125)I]BgTx) to halpha7- and [(3)H]cy to halpha4beta2- or halpha4beta4-nACh receptors. 3-Br-cy was the most potent inhibitor of both [alpha-(125)I]BgTx and [(3)H]cy binding. Cy was less potent than 3-Br-cy, but 5-Br-cy and 3,5-diBr-cy were the least potent inhibitors. Cy and 3-Br-cy were potent full agonists at halpha7-nACh receptors but behaved as partial agonists at halpha4beta2- and halpha4beta4-nACh receptors. 5-Br-cy and 3,5-diBr-cy had low potency and were partial agonists at halpha7- and halpha4beta4-nACh receptors, but they elicited no responses on halpha4beta2-nACh receptors. Cy and 3-Br-cy produced dual dose-response curves (DRC) at both halpha4beta2- and halpha4beta4-nACh receptors, but ACh produced dual DRC only at halpha4beta2-nACh receptors. Low concentrations of cy, 3-Br-cy and 5-Br-cy enhanced ACh responses of oocytes expressing halpha4beta2-nACh receptors, but at high concentrations they inhibited the responses. In contrast, 3,5-diBr-cy only inhibited, in a competitive manner, ACh responses of halpha4beta2-nACh receptors. It is concluded that bromination of the pyridone ring of cy produces marked changes in effects of cy that are manifest as nACh receptor subtype-specific differences in binding affinities and in functional potencies and efficacies.

High-density molecular map of chromosome region harboring stripe-rust resistance genes YrH52 and Yr15 derived from wild emmer wheat, Triticum dicoccoides

Two stripe-rust resistance genes, YrH52 and Yr15, derived from the Israeli wild emmer wheat, Triticum dicoccoides, have been located on chromosome 1B. The main objectives of the present study were to increase marker density in the vicinity of YrH52 gene by means of AFLP, RAPD and microsatellite markers, to improve the map of another T dicoccoides-derived stripe-rust resistance gene Yr15 using microsatellite markers, and to preliminarily discriminate these two genes. Additional 26 marker loci comprising 20 AFLPs, three RAPDs, and three microsatellites were found to be linked to YrH52 gene. An updated genetic map consisting of 45 marker loci, in the region of YrH52 gene, was constructed with a total map length of 107.7 cm. The mean interval length was 0.96 cm in the region Xgwm359b-P55M53b carrying YrH52 gene. YrH52 was bracketed by Xgwm413 (Nor1 and UBC212a) and Xgwm273a (Xgwm273d) with map distance of 1.3 and 2.7 cm from either side, respectively. Eight additional microsatellite markers were found to be linked with Yr15, and the linkage map of Yr15 gene was thus obviously improved. In the YrH52-mapping population, no crossover was detected in the interval UBC212a (Xgwm413)-Yr15-Nor1, and YrH52 was located distally outside this interval. It may suggest that YrH52 is different from Yr15 even though both of them are derived from T. dicoccoides and are mapped on chromosome 1BS. The large number of molecular makers revealed in the present study would be helpful for the marker-assisted introgression of the T. dicoccoides-derived YrH52 and Yr15 stripe-rust resistance genes into elite cultivars of wheat, and the high-density map would accelerate the map-based cloning of the two genes.

[HPLC/ESI MS and MALDI/TOF MS analysis of microheterogeneity of the N-linked oligosaccharides of recombinant human erythropoietin]

AIM

To elucidate the microheterogeneity of three N-linked oligosaccharide sites of the Chinese-made recombinant human erythropoietin (rHuEPO).

METHODS

Glu-C digestion, RP-HPLC separation, online HPLC/electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization time of flight mass spectrometry.

RESULTS

The sialic acid was analyzed directly. Almost every oligosaccharide was acetylated, the acetylation of tetraantennary + 2LacNAc + 4SA and tetraantennary + 2LacNAc + 4SA were reported.

CONCLUSION

The acetylation of multi-antennary oligosaccharide will improve the activity of rHuEPO in vivo. The biantennary oligosaccharide was found mainly existing at N-24. For the first time, the carbohydrate structures of each N-linked glycosylated site of Chinese-made rHuEPO were reported.

Pharmacokinetics of sustained-release capsule of 5-isosorbide mononitrate in 20 healthy Chinese young men

AIM

To compare the pharmacokinetics of domestic and imported sustained-release capsule of 5-isosorbide mononitrate (5-IM).

METHODS

A single and 5-d-repeated oral doses of 5-IM 50 mg were performed on 2 groups of 20 Chinese healthy subjects (10 subjects for each group) in a randomized crossover protocol. The 5-IM in plasma were measured by gas chromatography with electron-captured detector method. Data were analyzed automatically by using a CAPP program on a PC computer.

RESULTS

Fitting the 5-IM concentration-time curves to one-compartment model or following trapezoidal rule, the parameters such as Tmax, Cmax, Ke, MRT, and AUC were calculated and there were no significant differences between the two kinds of capsule. The major pharmacokinetic parameters of domestic and imported 5-IM sustained-release capsule with a 5-d multiple dose were respectively: Cmax (677 +/- 103) and (702 +/- 76) micrograms.L-1; Tmax (5.1 +/- 2.0) and (5.6 +/- 1.3) h; MRT (11.5 +/- 0.5) and (11.4 +/- 0.7) h; AUC0-infinity (12,121 +/- 1346) and (12,352 +/- 988) micrograms.h.L-1. The fraction of drug absorbed in vivo was correlated well with the percentage amount of drug released in vitro at corresponding time (P < 0.05), and the fluctuation indices on d 5 in multiple dose study were not significantly different between the two formulations (P > 0.05). The relative bioavailability of the domestic capsule for single and multiple dose were 96% +/- 11% and 98% +/- 10%, respectively.

CONCLUSION

Domestic 5-IM sustained-release capsule showed bioequivalence compared with the imported capsule and provided the same nitrate-low interval in the latter part of the 24-h dosing interval.

Effect of dietary lipids on phospholipase D activity in rat brain

Phospholipase D (PLD) is emerging as a major player in many novel signaling pathways. Based on recent studies correlating membrane composition with enzyme function, we speculated that feeding of dietary lipids to the newborns has a major impact on brain PLD activity. To test this hypothesis, the rat dams were fed fat-free powder containing either safflower oil or fish oil, and a control powdered chow. The pups were weaned onto the diet and sacrificed at 30 days of age. PLD activity was measured by transphosphatidylation assays using rat brain membranes. This study shows that microsome GTPgammaS-dependent PLD activity in rats fed safflower oil or fish oil was significantly reduced by 38% and 30% respectively compared to controls. Oleate-dependent PLD activity in the safflower oil group, however, was significantly increased by 38%. In contrast, synaptosome membrane (P2) GTPgammaS-dependent PLD activity in rats consuming safflower oil was significantly increased by 29%, but there was no difference in oleate-dependent PLD activity. Likewise, no difference was observed in microsome oleate-dependent PLD and P2 GTPgammaS-dependent PLD activity between the fish oil and the control groups. These results indicate that dietary lipid intake appears to modulate phospholipid metabolism and differential expression of PLD isozymes in the brain.

Inducible, heterologous expression of human alpha7-nicotinic acetylcholine receptors in a native nicotinic receptor-null human clonal line

Tetracycline-regulated expression of recombinant nicotinic acetylcholine receptors (nAChR) composed of human alpha7 subunits is achieved in native nAChR-null SH-EP1 human epithelial cells. alpha7 subunits are heterologously expressed as messenger RNA and as components of 125I-labeled alpha-bungarotoxin (I-Bgt)-binding nAChR ( approximately 10 pmol per milligram of membrane protein) at levels sensitive to the amount of tetracycline in cell growth medium. I-Bgt-binding alpha7-nAChR appear on the cell surface pool and in intracellular pools. The pharmacological profile for drug competition toward I-Bgt binding to these recombinant alpha7-nAChR matches that of human native alpha7-nAChR naturally expressed in SH-SY5Y human neuroblastoma cells (rank order potency methyllycaconitine>1, 1-dimethyl-4-phenylpiperazinium>(-)nicotine>cytisine>carbamylch oli ne> /=d-tubocurarine). Chronic exposure to nicotine induces up-regulation of human recombinant alpha7-nAChR (80% up-regulation at 10 microM nicotine) just as it does native alpha7-nAChR in other human cell lines. These studies confirm expression of nAChR as homooligomers of human alpha7 subunits from transgenes, establish a native nAChR-null background for such expression, and demonstrate that this expression can be regulated to facilitate studies of human alpha7-nAChR.

A comprehensive dynamical model of pulsatile secretion of the hypothalamo-pituitary-gonadal axis in man

We proposed a comprehensive dynamical model for the hormone secretion of the hypothalamo-pituitary-gonadal axis in man. This model is comprehensive and more reasonable than any previous model. A large number of deductions of this model agree well with experimental results.

[High performance liquid chromatographic assay for aceclofenac in plasma and its pharmacokinetics in dogs]

A sensitive and simplified high performance liquid chromatographic procedure has been developed for the quantification of aceclofenac and its major metabolite in dog plasma. The recovery of aceclofenac was 91.3%-96.9%. The relative standard deviation was 3.69%-8.13%. The calibration curve was linear in the range from 0.050 microgram.ml-1 to 51.2 micrograms.ml-1 with gamma = 0.9998. The detection limit of the method is 10 ng.ml-1 for aceclofenac. Plasma concentrations of both aceclofenac and its major metabolite were simultaneously determined. After oral medication of aceclofenac to dogs at the dose of 2.5 mg.kg-1, the drug was absorbed rapidly and reached its peak level in plasma at about 12 min. The plasma drug concentration-time course conformed to a 2-compartment open model with a first order absorption. The mean value of T1/2 alpha and T1/2 beta for aceclofenac were 2.5 min and 137 min respectively. Plasma diclofenac concentration, a major metabolite of aceclofenac, reached its maximum at about 110 min, the mean Cmax for diclofenac was 3.2 micrograms.ml-1. The mean terminal elimination half-life for diclofenac was 140 min.

Purification and immunochemical properties of human Na,K-ATPase alpha subunits and formic acid-derived polypeptide fragments

In this study, alpha (alpha) isoform proteins were purified from the partially purified Na,K-ATPase by SDS-PAGE and electroelution. Peptide mapping showed subtle biochemical differences between alpha subunit proteins of rat and human origin. The purified alpha proteins were treated with formic acid, the cleaved polypeptide fragments were separated by SDS-PAGE, the bands corresponding to 40, 50, and 60 kDa were excised, and the proteins were electroeluted. The purified 40, 50, and 60 kDa polypeptides were essentially homogeneous, and were used for preparation of polyclonal antibodies in rabbits. The antisera to alpha proteins (R alpha) and 60 & 40 kDa polypeptides (R60 & R40) were obtained and characterized by Western blotting. All three antisera were highly specific, since they cross-reacted with only the 100 kDa bands of the crude brainstem homogenates, of the axolemma, and of the cerebral cortex synaptosomes and microsomes. R alpha and R40 were successfully used for immunohistochemical staining of fibers in the white matter of the human brain frontal cortex. These antisera were not isoform-specific, they cross-reacted with 40, 50, and 60 kDa polypeptides as well as the three alpha bands.

Immunohistochemical localization of amyloid beta-protein deposits in extracerebral tissues of patients with Alzheimer's disease

An autopsy study was conducted on patients with Alzheimer's disease in order to explore the possibility of amyloid beta-protein deposits in tissues other than the brain. Immunoperoxidase staining techniques were employed using an amyloid beta-protein antiserum as primary antibody; paraffin sections of kidney, liver, heart, lung, spleen, bone marrow, colon, stomach, adrenal, thyroid, and brain were examined. Our autopsy cases were divided into two groups. The first group comprised 10 patients with Alzheimer's disease. The second group consisted of eight control cases, of age-matched individuals, that died of unrelated causes and showed no clinicopathologic evidence of Alzheimer's disease. Identification was made of strong, although focal, positive staining in two kidneys and one lung of three different patients with Alzheimer's disease. All other tissues, including the control cases, showed negative staining.

Aluminum-induced acute cholinergic neurotoxicity in rat

In the present study the acute effect of intravenous aluminum chloride (1 mg/kg) on choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activities of rats was investigated. Aluminum was found to cross the blood-brain barrier (BBB) as indicated by the detection of aluminum in the cerebrospinal fluid (CSF) 30 min after femoral vein injection. Two hours following aluminum injection, ChAT activity in the basal forebrain and hippocampus was significantly reduced by 30% and 22%, respectively, whereas no change was observed in the caudate nuclei. On the other hand, AChE activity was significantly increased by 45% in the caudate nuclei, whereas little change was observed in other brain areas. This report demonstrates that rapid transport of Al across the BBB, and the acute nature of Al neurotoxicity in rats.

Highly ouabain-sensitive alpha 3 isoform of Na+,K(+)-ATPase in human brain

The Na+,K(+)-ATPase alpha 3 isoform has recently been demonstrated immunochemically in human brain. Conclusive biochemical evidence, however, is still lacking. In this study, a unique 50-kDa polypeptide, which is known to be specific to the rat alpha 3 isoform, has been found in human brainstem Na+,K(+)-ATPase following formic acid treatment of the purified alpha isoform proteins. Human alpha 3 Na+,K(+)-ATPase is also highly sensitive to ouabain inhibition, with a 50% ouabain inhibition value of 1.0 x 10(-7) M. These results provide clear and direct evidence for the existence of the alpha 3 isoform in human brain.

Immunochemical demonstration of alpha 3 isozyme of Na,K-ATPase in human brain

The catalytic alpha (alpha) subunit of the human Na,K-ATPase is encoded by multiple genes, as revealed from molecular cloning studies, yet the presence of the alpha 3 isoform has still not been resolved. We investigated the human alpha 3 isoform by Western blotting employing polyclonal anti-rat brain alpha 3 fusion protein, and purified human and rat axolemma Na,K-ATPase preparations. The antibody to rat brain alpha 3 fusion protein cross-reacted with both human and rat antigens, and the stained band superimposed on the alpha 2 band. This result suggests that alpha 3 isoform also exists in human brain.

The cholinergic system of the human hindbrain studied by choline acetyltransferase immunohistochemistry and acetylcholinesterase histochemistry

A map of cholinergic cells of the human brainstem identified by immunohistochemistry of choline acetyltransferase (ChAT) is presented, along with a map of acetylcholinesterase (AChE)-containing cells and fibers. ChAT-positive structures belong to 4 brainstem systems: the cranial motor nuclei; the parabrachial complex; the reticular system; and the vestibular system. All motor nuclei of the cranial nerves, as well as the nucleus supraspinalis, are ChAT-positive. The positively staining structures of the parabrachial system include the nucleus tegmentali pedunculopontinus, and the nuclei parabrachialis medialis and lateralis. Nuclei of the reticular system containing some ChAT-positive cells include the nucleus reticularis pontis oralis and caudalis, the nucleus reticularis tegmenti pontis, the nucleus reticularis gigantocellularis, the nucleus reticularis lateralis and the formatio reticularis centralis (medulla). Structures of the vestibular and auditory systems which contain some ChAT-positive cells include the nucleus vestibularis lateralis, and the nuclei olivaris superioris medialis and lateralis. All ChAT-positive structures stain strongly for AChE. AChE-positive, ChAT-negative structures were noted in several sensory systems. The substantia nigra, locus coeruleus and raphe nuclei, known to contain non-cholinergic cells, also stain positively. The significance of the AChE-positive, ChAT-negative staining in most structures remains to be determined. A knowledge of the cholinergic systems of human brain may be important to an understanding of the pathology of a number of diseases.

Membrane-bound choline acetyltransferase from human brain: purification and properties

Choline acetyltransferase (ChAT; EC 2.3.1.6) was separated from human caudate/putamen into three fractions by successive extractions into a potassium phosphate buffer, a high salt (NaCl) buffer and a buffer containing 0.6% Triton X-100. The Triton-X-solubilized fraction is the membrane-bound ChAT (mChAT) and represents about 40% of the total ChAT. After centrifugation, mChAT was precipitated by ammonium sulfate at 35-65% saturation. The crude enzyme preparation was fractionated in turn on a DEAE-Sepharose, a hydroxylapatite and a phosphocellulose columns. Finally, mChAT was applied to a CoA-Sepharose column equilibrated with buffer containing 100 mM choline chloride and was specifically eluted with buffer containing acetyl-CoA. The presence of both substrates greatly stabilized the enzyme and ChAT was recovered almost quantitatively. The final preparation of mChAT has a specific activity of 37.2 mumol of acetylcholine synthesized per min-mg protein. The purified mChAT has a pH optimum of 8.3. It migrated as two bands on SDS-PAGE with molecular weights of 67,000 and 62,000 daltons, respectively. Immunoblot autoradiography showed that an antiserum prepared previously against soluble ChAT also cross-reacted with both bands of mChAT, indicating that both forms of this enzyme are related. Furthermore, as previously reported for soluble ChAT, Fab-Sepharose chromatography could be used for the purification of mChAT and this preparation also resolved into two bands on 10% SDS gel.

Anti-human choline acetyltransferase fragments antigen binding (FAB)-sepharose chromatography for enzyme purification

Fragments Antigen Binding (FAB)-Sepharose immunoaffinity chromatography was successfully applied to the purification of human choline acetyltransferase. The mild elution conditions made it possible to obtain the enzyme in its full catalytic state. The method should be generally applicable to enzyme purification.

Choline acetyltransferase immunohistochemistry in brains of Alzheimer's disease patients and controls

Choline acetyltransferase (ChAT)-containing neuronal structures of the basal forebrain were studied by ChAT immunohistochemistry in the brains of persons dying with Alzheimer's disease (SDAT), as well as age-matched controls dying without neurological disorder. A loss of greater than 50% in ChAT-containing neurons was found in the substantia innominata in the SDAT group. In contrast, there was no reduction in the number of ChAT-containing neurons of the putamen as compared with controls. The data confirm the reason for the reduction of ChAT as measured biochemically in the neocortex of SDAT cases, and support the cholinergic hypothesis of memory.

Cross-reactivity of antibodies to chicken brain choline acetyltransferase with mammalian enzyme

An antiserum was obtained from immunized rabbit after 3 subcutaneous injections of 100 micrograms each of a purified chicken choline acetyltransferase (ChAT) preparation, which had a specific activity of 2.32 mumol acetylcholine formed/min/mg protein. The antiserum or immunoglobulins strongly inhibited ChAt activities from chicken and mammalian brains in immunoprecipitation experiments. Furthermore, on double immunodiffusion and immunoelectrophoretic plates single precipitin lines were obtained with either pure or crude enzyme preparations from both chicken and human brain, and with crude preparations from rat and rabbit brain. Results from double immunodiffusion also showed non-identity reactions between avian and mammalian ChAT and partial identity among enzymes from different mammalian species. This study on cross-reactivity demonstrates that chicken and mammalian ChAT are non-identical enzymes, but common antibody recognition sites exist that appear to be monospecific for ChAT.

The central cholinergic system studied by choline acetyltransferase immunohistochemistry in the cat

An atlas of the distribution of cholinergic cell bodies, fibers, and terminals, as well as cholinoceptive cells, in the central nervous system of the cat (excluding the cerebellum) is presented from results obtained in immunohistochemical work on choline acetyltransferase. Cholinergic cell bodies are observed in more than forty areas, and cholinoceptive cells in sixty discrete areas of brain sections from the spinal cord to the olfactory bulb. The atlas is presented in seventy cross-sectional drawings of cat brain extending from the olfactory bulb to the upper cervical spinal cord.

Anti-choline acetyltransferase fragments antigen binding (Fab) for immunohistochemistry

The preparation of fragments antigen binding (Fab) from serum of rabbits immunized against human brain choline acetyltransferase (CAT) is described. Ant-CAT Fab fragments were less potent than anti-CAT immunoglobulin (IgG) in inhibiting mammalian CAT activity and did not precipitate CAT activity. They proved, however, far superior to anti-CAT IgG for the immunohistochemical staining of CAT in mammalian neurons.

Purification and immunochemical properties of choline acetyltransferase from human brain

Choline acetyltransferase (CAT) was purified to homogeneity from 363 g of human neostriatum by means of ammonium sulfate and protamine sulfate fractionation, followed by chromatography on DEAE-Sephadex, hydroxyapatite, phosphocellulose, and agarose-hexane-Co A columns. The final product migrated as a single component on 7.5% gels with or without SDS. It had a molecular weight of 66,000 daltons and a specific activity of 7.3 mumol acetylcholine formed per milligram protein per minute. Antibodies prepared in rabbits gave single precipitin lines against this protein on Ouchterlony immunodiffusion and immunoelectrophoresis plates. The CAT-anti-CAT IgG complex migrated as a single band on gel electrophoresis, establishing the monospecificity of the antibodies. Strong cross-reactivity to the IgG was obtained with CAT from rat, rabbit, and guinea pig, but only weak reactivity with chicken. Fab fragments were prepared from the rabbit IgG and were used to stain CAT-containing neurons in the spinal cord and nerve endings at the neuromuscular junction using the PAP technique.