YKL-40 in asthmatic patients, and its correlations with exacerbation, eosinophils and immunoglobulin E

The chitinase-like protein YKL-40, which binds chitin but lacks chitinase activity, has been found to be either the cause or a biomarker for asthma. The aim of our study was to investigate whether serum YKL-40 levels are increased in Chinese patients with asthma and identify its correlation to acute exacerbation, total serum immunoglobulin (Ig)E, the percentage of peripheral blood eosinophils and lung function. We quantified serum YKL-40 levels, total IgE levels and peripheral blood eosinophil percentages in patients with asthma, as well as in controls from the communities surrounding our hospital. The lung function of asthma subjects was also measured. Our data showed that the serum YKL-40 levels were significantly elevated in patients with asthma compared with controls and, when the asthma subjects were stratified, serum YKL-40 levels in the exacerbation group were higher than those in the stable and control groups. In addition, serum YKL-40 levels correlated positively with total serum IgE levels and the percentage of peripheral blood eosinophils, but correlated inversely with lung functions. Thus, we conclude that YKL-40 is found in increased quantities in the serum of Chinese patients with asthma, and its level correlates with exacerbation attacks, indicating that high levels of serum YKL-40 may be a biological characteristic of the exacerbation of asthma.

Fragment assembly with double-barreled data

For the last twenty years fragment assembly was dominated by the "overlap - layout - consensus" algorithms that are used in all currently available assembly tools. However, the limits of these algorithms are being tested in the era of genomic sequencing and it is not clear whether they are the best choice for large-scale assemblies. Although the "overlap - layout - consensus" approach proved to be useful in assembling clones, it faces difficulties in genomic assemblies: the existing algorithms make assembly errors even in bacterial genomes. We abandoned the "overlap - layout - consensus" approach in favour of a new Eulerian Superpath approach that outperforms the existing algorithms for genomic fragment assembly (Pevzner et al. 2001 InProceedings of the Fifth Annual International Conference on Computational Molecular Biology (RECOMB-01), 256-26). In this paper we describe our new EULER-DB algorithm that, similarly to the Celera assembler takes advantage of clone-end sequencing by using the double-barreled data. However, in contrast to the Celera assembler, EULER-DB does not mask repeats but uses them instead as a powerful tool for contig ordering. We also describe a new approach for the Copy Number Problem: "How many times a given repeat is present in the genome?". For long nearly-perfect repeats this question is notoriously difficult and some copies of such repeats may be "lost" in genomic assemblies. We describe our EULER-CN algorithm for the Copy Number Problem that proved to be successful in difficult sequencing projects.

Physicochemical properties and structure of large, medium and small granule starches in fractions of normal barley endosperm

Normal barley grain was milled to flour with a machine used to polish brewers' rice from the surface layer to the center. Large (18.4 microm, median size), medium (12.3 microm) and small (2.2 microm) granule starches were isolated from classified flours. Their physicochemical properties and fine structure were investigated. The percentage (w%) of large granules decreased from the surface layer to the center, while the amounts of medium and small granules increased. Although all the starch granules were an A-type crystal, the relative crystallinity varied from 22.0 to 27.4%. The DPn of the amyloses was around 1600 and similar for all the samples. But the amylose content of the starches varied from 21.9 to 26.4%. Also, the amylopectins showed differences in DPn (around 5700-7900) and chain-length distribution between granule size or fractions. The transition temperature ranges and the enthalpy values of the starch granules differed with granule size. The gelatinization properties showed no correlation with any of the parameters, except the enthalpy value and relative crystallinity (gamma = +0.73). The findings suggested that the structural characteristics of the starches in classified flours of normal barley differed essentially from those of waxy barley.

Analysis of osteocalcin expression in transgenic mice reveals a species difference in vitamin D regulation of mouse and human osteocalcin genes

A line of transgenic mice expressing a human osteocalcin genomic fragment (hOClocus) and a murine MC3T3-E1 cell line containing a stably integrated human osteocalcin promoter construct have been developed to characterize the osteogenic and hormonal regulation of human osteocalcin in vivo and in vitro. In this study, we used these models to demonstrate a species difference in the regulation of the mouse and human osteocalcin genes by vitamin D. Repeated administration of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) to mice carrying the hOClocus transgene resulted in striking increases in serum human osteocalcin, whereas serum mouse osteocalcin levels were unchanged after 24 h and only modestly increased 48 h after the second dose of hormone. 1,25(OH)2D3 increased human calvarial mRNA expression by 1.8-fold and slightly decreased mouse osteocalcin mRNA levels by approximately 1.2-fold. Furthermore, treatment of primary calvarial osteoblasts from these mice with 1,25(OH)2D3 increased human osteocalcin production but inhibited mouse osteocalcin protein accumulation. To investigate further the mechanism for the apparent species difference in vitamin D3 induction of mouse and human osteocalcin, we examined the effect of 1,25(OH)2D3 in an MC3T3-E1 cell line (MC4) containing a stably integrated 3900 bp osteocalcin promoter-luciferase construct. Treatment of MC4 cells with ascorbic acid resulted in parallel increases of the endogenous mouse osteocalcin protein and luciferase reporter activity over a 12-day period. Continuous exposure of MC4 cells to 1,25(OH)2D3 resulted in time-and dose-dependent increases in the activity of the phOC3900 luciferase construct. By contrast, the hormone had no effect on mouse osteocalcin protein concentrations and inhibited its induction by ascorbic acid. However, when cells were treated acutely with 1,25(OH)2D3 at later times during growth in ascorbic acid, the induction of mouse osteocalcin protein was only partially inhibited. In conclusion, our results indicate that common osteogenic signals regulate both mouse and human osteocalcin gene expression, but the mouse gene is resistant to induction by vitamin D. This species difference in vitamin D regulation of osteocalcin appears to result from the failure of 1,25(OH)2D3 to transcriptionally activate the mouse osteocalcin gene.

The effects of a monoclonal antibody to interferon-gamma on experimental autoimmune thyroiditis (EAT): prevention of disease and decrease of EAT-specific T cells

CBA/J mice immunized with thyroglobulin (Tg) develop an experimental autoimmune thyroiditis (EAT) with lymphocytic infiltration of the thyroid glands, autoantibodies to Tg and occurrence of EAT-specific T cells. When these mice were treated for 4 weeks after immunization with 1 mg/week of a monoclonal antibody (mAb) that neutralizes the activity of interferon-gamma (IFN) a beneficial effect on the onset of EAT was observed. Characteristic features of EAT were significantly reduced, including the lymphocytic infiltrations of the thyroid glands and the serum levels of autoantibodies to Tg. Moreover, in lymphoid organs, mAb to IFN-gamma significantly reduced the percentages of Tg-specific CD8+ cells, labeled by the anti-clonotypic mAb AG7. These Tg-specific T cells seem responsible for thyroid damages and disease development, since EAT was simultaneously abrogated. These results show that IFN-gamma plays an essential role in the pathophysiology of EAT and suggest the possibility to treat autoimmune thyroid diseases with mAb to IFN-gamma or drugs able to antagonize the production and/or the action of this cytokine.

Studies on the structure-activity relationship and interaction mechanism of flavonoids and xanthine oxidase through enzyme kinetics, spectroscopy methods and molecular simulations

In this study, some flavonoids were screened as potent xanthine oxidase (XO) inhibitors in vitro. Flavonoid 9 was demonstrated to exhibit the inhibitory activity through a ping-pong mechanism. Further structure-activity relationship revealed that different structural elements had greatly influenced the inhibition effect on XO and underlined the requirement of hydroxyl groups at C5 and C4' of flavonoid type I. Moreover, some bioactive flavonoids could efficiently quench the intrinsic fluorescence of XO by either static or static-dynamic mixed mechanism. The synchronous fluorescence, ANS-binding fluorescence, Fourier transform infrared spectra and circular dichroism suggested that active flavonoids could bind to the active center of XO, prevent the entrance of substrate, and induce the rearrangement and conformation change of its secondary structures, ultimately resulting in the significant inhibition effect. Additionally, molecular docking further confirmed these conclusions and highlighted the great importance of hydrophobic interactions and hydrogen bonds for the formation of stable complex conformation.

Neoadjuvant chemoradiotherapy versus neoadjuvant chemotherapy followed by minimally invasive esophagectomy for locally advanced esophageal squamous cell carcinoma: a prospective multicenter randomized clinical trial

BACKGROUND

Neoadjuvant therapy is recommended for locally advanced esophageal cancer, but the optimal strategy remains unclear. We aimed to evaluate the safety and efficacy of neoadjuvant chemoradiotherapy (nCRT) versus neoadjuvant chemotherapy (nCT) followed by minimally invasive esophagectomy (MIE) for locally advanced esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

Eligible patients staged as cT3-4aN0-1M0 ESCC were randomly assigned (1 : 1) to the nCRT or nCT group stratified by age, cN stage, and centers. The chemotherapy, based on paclitaxel and cisplatin, was administered to both groups, while concurrent radiotherapy was added for the nCRT group; then MIE was carried out. The primary endpoint was 3-year overall survival. This study is registered with ClinicalTrials.gov (NCT03001596).

RESULTS

A total of 264 patients were eligible for the intention-to-treat analysis. By 30 November 2021, 121 deaths had occurred. The median follow-up was 43.9 months (interquartile range 36.6-49.3 months). The overall survival in the intention-to-treat population was comparable between the nCRT and nCT strategies [hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.58-1.18; P = 0.28], with a 3-year survival rate of 64.1% (95% CI 56.4% to 72.9%) versus 54.9% (95% CI 47.0% to 64.2%), respectively. There were also no differences in progression-free survival (HR 0.83, 95% CI 0.59-1.16; P = 0.27) and recurrence-free survival (HR 1.07, 95% CI 0.71-1.60; P = 0.75), although the pathological complete response in the nCRT group (31/112, 27.7%) was significantly higher than that in the nCT group (3/104, 2.9%; P < 0.001). Besides, a trend of lower risk of recurrence was observed in the nCRT group (P = 0.063), while the recurrence pattern was similar (P = 0.802).

CONCLUSIONS

NCRT followed by MIE was not associated with significantly better overall survival than nCT among patients with cT3-4aN0-1M0 ESCC. The results underscore the pending issue of the best strategy of neoadjuvant therapy for locally advanced bulky ESCC.

A Drosophila doublesex-related gene, terra, is involved in somitogenesis in vertebrates

The Drosophila doublesex (dsx) gene encodes a transcription factor that mediates sex determination. We describe the characterization of a novel zebrafish zinc-finger gene, terra, which contains a DNA binding domain similar to that of the Drosophila dsx gene. However, unlike dsx, terra is transiently expressed in the presomitic mesoderm and newly formed somites. Expression of terra in presomitic mesoderm is restricted to cells that lack expression of MyoD. In vivo, terra expression is reduced by hedgehog but enhanced by BMP signals. Overexpression of terra induces rapid apoptosis both in vitro and in vivo, suggesting that a tight regulation of terra expression is required during embryogenesis. Terra has both human and mouse homologs and is specifically expressed in mouse somites. Taken together, our findings suggest that terra is a highly conserved protein that plays specific roles in early somitogenesis of vertebrates.

Immunosuppressive effect of the gut microbiome altered by high-dose tacrolimus in mice

The alterations induced in gut microbiota by tacrolimus may affect immune function and organ transplantation. Mice were treated with high-dose tacrolimus for 14 days. The fecal microbiota were analyzed by pyrosequencing the 16S rRNA genes, and the effect on metabolism was predicted using the sequence data. The subgroups of T cells in the serum, gut-associated lymphoid tissue, and draining lymph nodes were determined by flow cytometry. Tacrolimus treatment significantly altered the relative abundance of Allobaculum, Bacteroides, and Lactobacillus and CD4⁺ CD25^hi FoxP3⁺ regulatory T cells in the colonic mucosa and the circulation. These were significantly increased after either tacrolimus treatment or treatment by fecal microbiota transfer from tacrolimus-treated donors. Further, treatment with low-dose tacrolimus plus fecal microbiota transfer from high-dose tacrolimus-altered mice increased skin allograft survival rate in a skin transplantation model. Thus, high-dose tacrolimus alters the compositions and taxa of the gut microbiota. Administration of these conditioned gut microbiota plus low-dose tacrolimus resulted in regulation of colonic and systemic immune responses and an increased allograft survival rate. This study demonstrated a new strategy for controlling allograft rejection by combining an immunosuppressive agent with gut microbiome transplantation.

Sam68, RNA helicase A and Tap cooperate in the post-transcriptional regulation of human immunodeficiency virus and type D retroviral mRNA

Unlike cellular mRNA, retroviral mRNA bypasses the tight coupling of the splicing and nuclear export steps to allow the export of intron-containing viral RNA transcripts to the cytoplasm. Two distinct nuclear export pathways for retroviral mRNA have been described: a CRM-1 dependent pathway mediated by the HIV-1 Rev protein and the Rev Response Element (RRE), and a CRM-1 independent pathway mediated by the Constitutive Transport Element (CTE) of type D retroviruses. Two CTE-binding proteins, RNA helicase A (RHA) and Tap, have been implicated in the nuclear export of CTE-containing RNA. Recently, we reported that expression of RRE-containing RNA could also be mediated by a cellular protein, Sam68, independently of Rev. Here we report evidence that Sam68, RHA and Tap cooperate in the nuclear export of both CTE- and RRE-containing RNA. RHA binds to Sam68 and to Tap both in vivo and in vitro. Over-expression of Sam68 activates both RRE- and CTE-regulated reporter gene expression in human cells and in quail cells in the presence of human Tap. This activation was competitively inhibited by the nuclear transport domain (NTD) of RHA and a transdominant negative mutant of Tap. Conversely, the activation of CTE by Tap in quail cells was inhibited by a transdominant mutant of Sam68 and NTD. We propose that both HIV and type D retroviruses may access the same constitutive RNA nuclear export pathway involving RHA, Tap and Sam68, even though HIV also utilizes the Rev protein for more efficient nuclear export. it is likely that this constitutive export pathway is also used by cellular mRNA, but at a different interface with the splicing process.

Molecular regulation of constitutive expression of interleukin-8 in human pancreatic adenocarcinoma

Recent studies have shown that interleukin-8 (IL-8) plays an important role in the growth and metastasis of human pancreatic cancer. In the present study, we determined the molecular regulation of constitutive IL-8 expression in human pancreatic cancer cells. Various human pancreatic cancer cell lines were incubated in vitro. Sixty-seven percent of the cell lines constitutively secreted high levels of IL-8, as determined using enzyme-linked immunosorbent assay. Consistently, these cells constitutively expressed high levels of IL-8 mRNA, as determined using Northern blot analysis. To determine the mechanisms of the high steady-state levels of IL-8 mRNA, the IL-8 half-life and transcription rate were measured. There was no significant difference in IL-8 half-life between cells expressing high and low levels of IL-8. However, higher transcription rates and increased IL-8 promoter activity were observed in the cells constitutively expressing high levels of IL-8. Detailed IL-8 promoter analysis using deletion mutation revealed that the region from -85 to -133 bp was essential for the constitutive IL-8 promoter activity. Also, point-mutation analysis indicated that mutation of NF-kappaB, AP-1, or NF-IL-6 binding sites significantly reduced or eliminated the constitutive IL-8 promoter activity. Consistent with the constitutive IL-8 transcription activity, high levels of constitutive NF-kappaB and AP-1 activity were detected in the cells overexpressing IL-8, as determined using electrophoretic mobility shift assay. In addition, transfection of a dominant-negative I-kappaBalpha expression vector (I-kappaBalphaM) inhibited constitutive NF-kappaB activity and IL-8 expression in pancreatic cancer cells. Collectively, our data demonstrated that constitutive NF-kappaB and AP-1 activation contributes to the overexpression of IL-8, which in turn plays an important role in tumor angiogenesis and contributes to the aggressive biology of human pancreatic cancer.

Acid-Base Properties of Aqueous Illite Surfaces

In this paper, the acid-base properties of illite/water suspensions are examined using the constant capacitance surface complexation model. On the basis of results of potentiometric titrations and solubility experiments, we conclude that the proton reactions in the supernatants of illite suspensions can be successfully represented by proton reactions of Al(H2O)63+ and Si(OH)4 in water solutions. For illustrating the acidic characteristics of aqueous illite surfaces, two surface protonation models are proposed: (1) one site-one pKa model, identical withSOH right arrow over left arrow identical withSO- + H+, pKaint = 4.12-4.23; (2) two sites-two pKas model, identical withSIOH right arrow over left arrow identical withSIO- + H+, pKintaI = 4.17-4.44, and identical withSIIOH right arrow over left arrow identical withSIIO- + H+, [dipKintaII = 6.35-7.74. Evaluation of these two models indicates that both of them can give good descriptions of the experimental data of systems with different illite concentrations and ionic strengths and that the one site-one pKa model can be considered as a simplification of the two sites-two pKas model. Since both models assume only deprotonation reactions at the illite surfaces, they suggest that the surface behavior of the illite is similar to that of amorphous SiO2. Model assumptions, experimental procedures, and evaluative criteria are detailed in the paper.

Functional interaction of the HTLV-1 transactivator Tax with activating transcription factor-4 (ATF4)

The Tax protein of the Human T-cell Leukemia Virus (HTLV) activates the expression of viral mRNA through a three 21 bp repeat enhancer located within the HTLV-1 LTR. Since Tax does not bind to the 21 bp DNA repeats directly, it has been speculated that Tax interacts with cellular protein(s) which mediate binding to the enhancer. We employed the yeast two hybrid system to identify host proteins that are potentially relevant to Tax transactivation. We identified a Tax binding protein encoded from a cDNA expression library derived from peripheral blood lymphocytes. The corresponding cDNA has sequence identity with a known transcription factor, activating factor-4 (ATF-4). ATF-4 also binds to GST-Tax fusion protein in vitro. Tax mutants that did not transactivate the HTLV-1 LTR also failed to bind ATF-4. The critical domain for Tax binding resides in a 85 amino acid stretch in the C-terminus of ATF-4, which contains the basic domain and leucine zipper. We further demonstrated that both full length and N-terminal truncated ATF-4 were able to enhance Tax transactivation. Thus, ATF-4 may act as an adapter between Tax and the TRE (Tax responsive element), and play an important role in Tax-mediated transactivation.

Poor outcome in patients with diabetes mellitus undergoing liver transplantation

BACKGROUND

Relatively few studies have examined the influence of pretransplant diabetes on survival after an orthotopic liver transplant (OLT), and those published to date show only minor increases in infection rates among diabetics and no increase in mortality.

METHODS

We examined the effect of diabetes mellitus on survival after OLT. 1005 adults underwent OLT between 1982 and May 1997. Seventy-eight patients with pretransplant diabetes mellitus (7.8% of all OLT, 38 insulin treated, 25 tablet treated, 15 diet controlled) were identified and compared with controls matched for age, sex, and date of first transplant and also with all nondiabetic adult liver recipients undergoing OLT during the same period.

RESULTS

In patients undergoing OLT survival was worse in diabetics than in the comparison group (P=0.002) and vs. all adult nondiabetics undergoing (n=927) (P=0.004); in diabetics with alcoholic liver disease (ALD) vs. all nondiabetics with alcoholic liver disease (P= <0.0001); and in insulin-treated compared with non-insulin-treated diabetics (P=0.05). Multivariate analysis showed type of diabetes (P=0.001) and ALD (P=0.024) to be the most significant independent variables adversely affecting survival. Survival in diabetics undergoing OLT could be further stratified according to whether diabetics were insulin treated.

CONCLUSIONS

Poorer outcome in the diabetics undergoing OLT, particularly in those with ALD, suggests the need for a more detailed pre-OLT assessment of these patients, particularly those with insulin and tablet controlled diabetes.

Determinants of RNA polymerase alpha subunit for interaction with beta, beta', and sigma subunits: hydroxyl-radical protein footprinting

Escherichia coli RNA polymerase (RNAP) alpha subunit serves as the initiator for RNAP assembly, which proceeds according to the pathway 2 alpha-->alpha 2-->alpha 2 beta-->alpha 2 beta beta'-->alpha 2 beta beta' sigma. In this work, we have used hydroxyl-radical protein footprinting to define determinants of alpha for interaction with beta, beta', and sigma. Our results indicate that amino acids 30-75 of alpha are protected from hydroxyl-radical-mediated proteolysis upon interaction with beta (i.e., in alpha 2 beta, alpha 2 beta beta', and alpha 2 beta beta' sigma), and amino acids 175-210 of alpha are protected from hydroxyl-radical-mediated proteolysis upon interaction with beta' (i.e., in alpha 2 beta beta' and alpha 2 beta beta' sigma). The protected regions are conserved in the alpha homologs of prokaryotic, eukaryotic, archaeal, and chloroplast RNAPs and contain sites of substitutions that affect RNAP assembly. We conclude that the protected regions define determinants of alpha for direct functional interaction with beta and beta'. The observed maximal magnitude of protection upon interaction with beta and the observed maximal magnitude of protection upon interaction with beta' both correspond to the expected value for complete protection of one of the two alpha protomers of RNAP (i.e., 50% protection). We propose that only one of the two alpha protomers of RNAP interacts with beta and that only one of the two alpha protomers of RNAP interacts with beta'.

Regulation of calcium-sensitive tyrosine kinase Pyk2 by angiotensin II in endothelial cells. Roles of Yes tyrosine kinase and tyrosine phosphatase SHP-2

Calcium-sensitive tyrosine kinase Pyk2 has been implicated in the regulation of ion channels, cellular adhesion, and mitogenic and hypertrophic reactions. In this study, we have investigated the regulation of Pyk2 by angiotensin II (Ang II) in pulmonary vein endothelial cells. We found that the Ang II-induced tyrosine phosphorylation of Pyk2, which requires the activity of Src family kinase, was specifically regulated by the Src family kinase member, Yes kinase. Moreover, we identified for the first time the constitutive association of Pyk2 with an Src homology 2 (SH2) domain-containing tyrosine phosphatase SHP-2. SHP-2 interacts with Pyk2 through a region other than its SH2 domains. Pyk2 can be dephosphorylated in vitro in SHP-2 immunoprecipitates and in intact cells expressing an NH(2) terminus-truncated form of SHP-2, which lacks the two SH2 domains but has an enhanced phosphatase activity. Ang II activates the endogenous SHP-2. Finally, the SHP-2-mediated dephosphorylation of Pyk2 correlates with the negative effect of SHP-2 on the Ang II-induced activation of extracellular signal-regulated kinase and c-Jun NH(2)-terminal kinase. Thus, the balance of Pyk2 tyrosine phosphorylation in response to Ang II is controlled by Yes kinase and by a tyrosine phosphatase SHP-2 in endothelial cells.

The use of mycophenolate mofetil suspension in pediatric renal allograft recipients

Mycophenolate mofetil (MMF) is widely used to prevent acute rejection in adults after renal, cardiac, and liver transplantation. This study investigated the safety, tolerability, and pharmacokinetics of MMF suspension in pediatric renal allograft recipients. One hundred renal allograft recipients were enrolled into three age groups (33 patients, 3 months to <6 years; 34 patients, 6 to <12 years; 33 patients, 12 to 18 years). Patients received MMF 600 mg/m2 b.i.d. concomitantly with cyclosporine and corticosteroids with or without antilymphocyte antibody induction. One year after transplantation, patient and graft survival (including death) were 98% and 93%, respectively. Twenty-five patients (25%) experienced a biopsy-proven (Banff grade borderline or higher) or presumptive acute rejection within the first 6 months post-transplantation. Analysis of pharmacokinetic parameters for mycophenolic acid (MPA) and mycophenolic acid glucuronide showed no clinically significant differences among the age groups. The dosing regimen of MMF 600 mg/m2 b.i.d. achieved the targeted early post-transplantation MPA 12-h area under concentration-time curve (AUC0-12) of 27.2 microg h per ml. Adverse events had similar frequencies among the age groups (with the exception of diarrhea, leukopenia, sepsis, and anemia, which were more frequent in the <6 years age group) and led to withdrawal of MMF in about 10% of patients. Administration of MMF 600 mg/m2 b.i.d. is effective in prevention of acute rejection, provides predictable pharmacokinetics, and is associated with an acceptable safety profile in pediatric renal transplant recipients.

Brain magnetic resonance imaging abnormalities in neuromyelitis optica

OBJECTIVE

Brain abnormalities in neuromyelitis optica (NMO) attracted much attention. Our study was to identify the brain magnetic resonance imaging (MRI) abnormalities in Chinese NMO patients.

METHODS

Patients who fulfilled the latest diagnostic criteria of NMO proposed by Wingerchuk et al. [Neurology 66 (2006) 1485] and whose brain MRI did not meet the multiple sclerosis (MS) criteria of McDonald et al. [Ann Neurol 50 (2001) 121] were selected to perform MRI scanning of the brain, spinal cord and optic nerves.

RESULTS

Twenty-eight of 33 patients (84.8%) had abnormal MRI findings. Twenty-two patients (66.7%) presented with well-defined brain parenchymal lesions and the other six patients (18.2%) with macroscopic symmetrical diffuse hyperintensities in deep white matter. Fifteen of 22 patients had more than one lesion (> or =2 lesions) and the other seven patients had single lesion. In the supratentorium, most lesions were punctate or small round dot and non-specific in juxtacortical, subcortical and deep white matter regions, a few were patchy atypical confluent lesions. Brainstem was easily involved (14/33, 42.4%) especially in medulla (7/33, 21.2%).

CONCLUSIONS

This study demonstrates the characteristics of brain MRI abnormalities in Chinese NMO patients, which are helpful to the revision of diagnostic criteria for NMO.

Functional magnetic resonance imaging study on dysphagia after unilateral hemispheric stroke: a preliminary study

BACKGROUND

Swallowing dysfunction is common and disabling after acute stroke; however, the mechanism of dysphagia or recovery of swallowing from dysphagia remains uncertain. The purpose of this study was to explore cerebral activation of swallowing in dysphagia using functional MRI (fMRI) to compare the functional anatomy of swallowing in unilateral hemispheric stroke patients and healthy adults.

METHODS

In total, five left hemispheric stroke patients with dysphagia, five right hemispheric stroke patients with dysphagia and 10 healthy controls were examined with event related fMRI while laryngeal swallow related movements were recorded. Data were processed using the general linear model.

RESULTS

A multifocal cerebral representation of swallowing was identified predominantly in the left hemisphere, in a bilateral and asymmetrical manner. Cerebral activation during swallowing tasks was localised to the precentral, postcentral and anterior cingulate gyri, insula and thalamus in all groups. Activation of volitional swallowing in dysphagic unilateral hemispheric stroke patients might require reorganisation of the dominant hemispheric motor cortex, or a compensatory shift in activation to unaffected areas of the hemisphere.

CONCLUSIONS

The results indicate that unilateral stroke of either cerebral hemisphere can produce dysphagia. Effective recovery is associated with cerebral activation related to cortical swallowing representation in the compensating or recruited areas of the intact hemisphere. Functional MRI is a useful method for exploring the spatial localisation of changes in neuronal activity during tasks that may be related to recovery. Therefore, the subsequent information gleaned from changes in neural plasticity could be useful for assessing the prognosis of dysphagic stroke.

Pituitary adenylate cyclase activating polypeptide immunoreactivity in the rat spinal cord and medulla: implication of sensory and autonomic functions

Immunoreactivity to pituitary adenylate cyclase activating polypeptide-38 was detected in numerous nerve fibres in layers I and II of the dorsal horn of the rat and some of these fibres extended into the deeper layers of all segments of the spinal cord. Immunoreactivity was also detected in the lateral funiculus projecting into the intermediolateral cell column of the lower cervical and thoracic segments and in the lateral pathway terminating in the intermediate gray area of the lower lumbar and sacral segments. Neurons in the lateral horn area were not immunoreactive nor were the ventral horn motoneurons. In the medulla, numerous immunoreactive fibres were observed in the spinal trigeminal tract and superficial layers of the caudal spinal trigeminal nucleus but few in the interpolar spinal trigeminal nucleus. A prominent immunoreactive nerve bundle emanated from the caudal spinal trigeminal nucleus and projected into the solitary tract. A dense network of immunoreactive neurons and fibres was present in the nucleus raphe obscurus, lateral reticular nucleus and parvocellular lateral reticular nucleus. Immunoreactive fibres could also be detected in the solitary tract and area postrema. Labelled somata were occasionally noted in various subnuclei of the nucleus of the solitary tract and nucleus raphe pallidus. In addition, a small number of positive neurons were detected in an area between the lateral reticular nucleus and inferior olive and near the ventral surface of the medulla (parapyramidal region). A few weakly-labelled cells were occasionally seen in the dorsal motor nucleus of vagus. A population of neurons in the trigeminal, nodose and dorsal root ganglia from all segments of the spinal cord displayed low to intense immunoreactivity. The presence of immunoreactivity in nodose and dorsal root ganglia, dorsal horn, spinal autonomic nuclei, solitary tract and in certain areas of the medulla suggests that this peptide may participate in a variety of sensory and autonomic functions.