Congestion of superior mesenteric veins and small bowel mucosal injury after endoscopic treatment of esophageal varices in patients with portal hypertension

We investigated treatment-induced changes in venous return from the small bowel and small bowel intestinal mucosal injury induced by the treatment of esophageal varices in patients with portal hypertension. A total of 14 patients (age 59.8+/-9.5 years, five women and 9 men) who received prophylactic treatment of esophageal varices between December 1998 and March 1999 were investigated. Diamine oxidase (DAO) activity was measured before and after treatment. Changes in blood flow of the portal and superior mesenteric veins were investigated by Doppler ultrasonography in six patients. A significant decrease in DAO activity was observed three days after treatment (11.5+/-1.6 units/liter prior to treatment versus 8.6+/-1.6 units/liter three days after treatment; P < 0.001). Decreases in superior mesenteric and portal venous flow velocity were observed in four and three patients, respectively. In two patients with an increase in the cross-sectional area of the superior mesenteric vein with delayed venous return, a marked decrease in DAO activity was observed three days after treatment. In patients with portal hypertension, rapid reduction of pooling of portal flow caused by the treatment of esophageal varices can induce transient congestion of the mesenteric venous system which can produce some small bowel mucosal injury.

Impairment of an event-related potential correlate of memory in schizophrenia: effects of immediate and delayed word repetition

OBJECTIVE

We investigated the nature of the memory impairment in schizophrenia using an event-related potential (ERP).

METHODS

Visual ERPs were recorded while 20 schizophrenics and 20 controls performed semantic categorization tasks with incidental word repetitions. Participants responded to occasional target words. Half of the non-target words were repeated immediately after initial presentation (lag 0) or after 5 intervening words (lag 5).

RESULTS

In both groups, ERPs to words at lag 0 were more positive than those to non-repeated words, though this positive-going effect was attenuated in the schizophrenics, especially around 400-500 ms. The effect at lag 5 was smaller and shorter than that at lag 0 but was comparable between groups. Attenuation of the N400 peak occurred for word repetition at lag 0 in controls but not in schizophrenics, whereas a peak increment in the late positive component induced by word repetition at both lags was observed in both groups.

CONCLUSIONS

Findings indicate that patients with schizophrenia have a deficit in a brain process modulating ERP correlates of memory, when words are repeated immediately. This deficit might be related to an abnormal N400 priming effect in schizophrenia.

Isolation of iso-grayanotoxin II from leaves of Leucothoe grayana Max. Its X-ray crystallographic analysis and acute toxicity in mice

The structure of iso-grayanotoxin II, a new diterpenoid from Leucothoe grayana MAX., has been determined as 3 beta,5 beta,6 beta,14 beta,16 alpha-pentahydroxygrayanotox-9(10)-ene by spectroscopic and X-ray crystallographic analysis. The lethal dosage level of iso-grayanotoxin II in mice was lower than that of grayanotoxin III.

Coniferyl aldehyde 5-hydroxylation and methylation direct syringyl lignin biosynthesis in angiosperms

A central question in lignin biosynthesis is how guaiacyl intermediates are hydroxylated and methylated to the syringyl monolignol in angiosperms. To address this question, we cloned cDNAs encoding a cytochrome P450 monooxygenase (LsM88) and a caffeate O-methyltransferase (COMT) from sweetgum (Liquidambar styraciflua) xylem. Mass spectrometry-based functional analysis of LsM88 in yeast identified it as coniferyl aldehyde 5-hydroxylase (CAld5H). COMT expressed in Escherichia coli methylated 5-hydroxyconiferyl aldehyde to sinapyl aldehyde. Together, CAld5H and COMT converted coniferyl aldehyde to sinapyl aldehyde, suggesting a CAld5H/COMT-mediated pathway from guaiacyl to syringyl monolignol biosynthesis via coniferyl aldehyde that contrasts with the generally accepted route to sinapate via ferulate. Although the CAld5H/COMT enzyme system can mediate the biosynthesis of syringyl monolignol intermediates through either route, k(cat)/K(m) of CAld5H for coniferyl aldehyde was approximately 140 times greater than that for ferulate. More significantly, when coniferyl aldehyde and ferulate were present together, coniferyl aldehyde was a noncompetitive inhibitor (K(i) = 0.59 microM) of ferulate 5-hydroxylation, thereby eliminating the entire reaction sequence from ferulate to sinapate. In contrast, ferulate had no effect on coniferyl aldehyde 5-hydroxylation. 5-Hydroxylation also could not be detected for feruloyl-CoA or coniferyl alcohol. Therefore, in the presence of coniferyl aldehyde, ferulate 5-hydroxylation does not occur, and the syringyl monolignol can be synthesized only from coniferyl aldehyde. Endogenous coniferyl, 5-hydroxyconiferyl, and sinapyl aldehydes were detected, consistent with in vivo operation of the CAld5H/COMT pathway from coniferyl to sinapyl aldehydes via 5-hydroxyconiferyl aldehyde for syringyl monolignol biosynthesis.

Compartmentalized expression of two structurally and functionally distinct 4-coumarate:CoA ligase genes in aspen (Populus tremuloides)

4-Coumarate:CoA ligases (4CLs, EC 6.2.1.12) are a group of enzymes necessary for maintaining a continuous metabolic flux for the biosynthesis of plant phenylpropanoids, such as lignin and flavonoids, that are essential to the survival of plants. So far, various biochemical and molecular studies of plant 4CLs seem to suggest that 4CL isoforms in plants are functionally indistinguishable in mediating the biosynthesis of these phenolics. However, we have discovered two functionally and structurally distinct 4CL genes, Pt4CL1 and Pt4CL2 (63% protein sequence identity), that are differentially expressed in aspen (Populus tremuloides). The Escherichia coli-expressed and purified Pt4CL1 and Pt4CL2 proteins exhibited highly divergent substrate preference as well as specificity that reveal the association of Pt4CL1 with the biosynthesis of guaiacyl-syringyl lignin and the involvement of Pt4CL2 with other phenylpropanoid formation. Northern hybridization analysis demonstrated that Pt4CL1 mRNA is specifically expressed in lignifying xylem tissues and Pt4CL2 mRNA is specifically expressed in epidermal layers in the stem and the leaf, consistent with the promoter activities of Pt4CL1 and Pt4CL2 genes based on the heterologous promoter-beta-glucouronidase fusion analysis. Thus, the expression of Pt4CL1 and Pt4CL2 genes is compartmentalized to regulate the differential formation of phenylpropanoids that confer different physiological functions in aspen; Pt4CL1 is devoted to lignin biosynthesis in developing xylem tissues, whereas Pt4CL2 is involved in the biosynthesis of other phenolics, such as flavonoids, in epidermal cells.

Alteration of T-lymphocyte subpopulations in patients with primary renal diseases and systemic lupus erythematosus

Forty-eight patients with a variety of primary renal diseases and systemic lupus erythematosus (SLE) were examined for the proportion of circulating T lymphocytes bearing receptors for IgM (T mu cells) or IgG (T gamma cells). Although the control group showed strikingly similar mean values for both T mu and T gamma cells, the whole group of patients with primary renal diseases and SLE showed a wide scatter of values. Sixteen patients with primary renal diseases and SLE had higher proportions of T gamma cells than the control group, whereas seven patients with chronic glomerulonephritis (CGN), membranoproliferative glomerulonephritis (MPGN), lipoid nephrosis (LN), and SLE showed very marked decrease in the proportions of T gamma cells in the peripheral blood. On the other hand, six out of the total group of patients had low proportions of T mu cells in the peripheral blood. However, no consistent relationship between the proportion of T mu and T gamma cells was found in our study. These findings indicate that there exists a heterogeneity of T-lymphocyte subpopulation distribution in some patients with primary renal diseases and SLE. The possible significance of these phenomena in the pathophysiology of renal diseases is discussed.

[Color Doppler signal enhancement with SH/TH-508 in pancreatic tumors]

In this report, we showed the efficacy of a new contrast agent (SH/TA-508, Schering AG, Germany) for color Doppler imaging of the pancreatic tumors. In pancreatic ductal cancer, no enhancement of the lesion was observed, but vascular invasion by cancer became to be easily evaluated. On the other hand, hypervascular tumors such as islet cell tumor and cystadenocarcinoma, were increased in color Doppler signals of vessels by SH/TA-508. We concluded that SH/TA-508 was useful for evaluating the vascular invasion by pancreatic cancer as well as vascularity of hypervascular mass and solid component of cystic neoplasma.

A novel multifunctional O-methyltransferase implicated in a dual methylation pathway associated with lignin biosynthesis in loblolly pine

S-adenosyl-L-methionine (SAM)-dependent O-methyltransferases (OMTs) catalyze the methylation of hydroxycinnamic acid derivatives for the synthesis of methylated plant polyphenolics, including lignin. The distinction in the extent of methylation of lignins in angiosperms and gymnosperms, mediated by substrate-specific OMTs, represents one of the fundamental differences in lignin biosynthesis between these two classes of plants. In angiosperms, two types of structurally and functionally distinct lignin pathway OMTs, caffeic acid 3-O-methyltransferases (CAOMTs) and caffeoyl CoA 3-O-methyltransferases (CCoAOMTs), have been reported and extensively studied. However, little is known about lignin pathway OMTs in gymnosperms. We report here the first cloning of a loblolly pine (Pinus taeda) xylem cDNA encoding a multifunctional enzyme, SAM:hydroxycinnamic Acids/hydroxycinnamoyl CoA Esters OMT (AEOMT). The deduced protein sequence of AEOMT is partially similar to, but clearly distinguishable from, that of CAOMTs and does not exhibit any significant similarity with CCoAOMT protein sequences. However, functionally, yeast-expressed AEOMT enzyme catalyzed the methylation of CAOMT substrates, caffeic and 5-hydroxyferulic acids, as well as CCoAOMT substrates, caffeoyl CoA and 5-hydroxyferuloyl CoA esters, with similar specific activities and was completely inactive with substrates associated with flavonoid synthesis. The lignin-related substrates were also efficiently methylated in crude extracts of loblolly pine secondary xylem. Our results support the notion that, in the context of amino acid sequence and biochemical function, AEOMT represents a novel SAM-dependent OMT, with both CAOMT and CCoAOMT activities and thus the potential to mediate a dual methylation pathway in lignin biosynthesis in loblolly pine xylem.

Characterization of the structure and determination of mRNA levels of the phenylalanine ammonia-lyase gene family from Populus kitakamiensis

We isolated two new PAL genes, palg2b and palg4, from Populus kitakamiensis, palg2a and palg2b are clustered and palg2b encodes a polypeptide of 710 amino acids. The nucleotide sequence in the coding region of palg2b was 94.6% identical to that of palg2a. The promoter regions of palg1, palg2a and palg2b have several elements conserved among many phenylpropanoid biosynthetic genes. We measured the mRNA levels of the four PAL genes by S1 mapping using total RNA from stem tissues developing secondary xylem. Results showed that the transcript level of palg2b was higher than that of the other PAL genes.

Molecular cloning of two tandemly arranged peroxidase genes from Populus kitakamiensis and their differential regulation in the stem

A genomic library was prepared from Populus kitakamiensis and screened with the cDNA for an anionic peroxidase from P. kitakamiensis. One genomic clone was isolated that contained two tandemly oriented genes for anionic peroxidases, prxA3a and prxA4a. Both genes consisted of four exons and three introns; the introns had consensus nucleotides, namely, GT and AG, at their 5' and 3' ends, respectively. The prxA3a and prxA4a genes encoded 347 and 343 amino acid residues, respectively, including putative signal sequences at the amino-termini. Putative promoters and polyadenylation signals were found in the flanking regions of both genes. The sequence of the coding region of prxA3a was completely identical to that of the cDNA clone pA3, whereas the sequence of the coding region of prxA4a was only 73% identical to that of the cDNA clone pA3. Northern blot analysis showed that the patterns of expression of the mRNAs that corresponded to prxA3a and prxA4a differed in stems of P. kitakamiensis.

Smooth pursuit eye movements and express saccades in schizophrenic patients

Abnormalities of saccades such as disinhibition have been hypothesized as one cause of smooth pursuit eye movement (SPEM) dysfunctions in schizophrenia. Thus, we studied saccadic eye movements in schizophrenics with SPEM dysfunction. Subjects were divided into three groups: 10 normal control subjects, 10 schizophrenic subjects without SPEM dysfunction and 10 schizophrenic subjects with SPEM dysfunction characterized by a cogwheel appearance. Visually guided saccades in gap and overlap paradigms (Saslow, 1967) were examined and saccadic reaction times (SRTs) were measured in all subjects. Only schizophrenics with SPEM dysfunctions tended to manifest excessive reflexive saccades, named express saccades (Fischer, 1987), in the gap paradigm. Moreover, most of them were also found to have express saccades in the overlap paradigm, whereas normal subjects and schizophrenic subjects without SPEM dysfunction did not show such phenomena under the same conditions. In particular, most express saccades in the overlap paradigm in schizophrenics with SPEM dysfunction, were found in movements to the right.

Smooth pursuit eye movements and voluntary control of saccades in the antisaccade task in schizophrenic patients

It has been hypothesized that a saccade control dysfunction is one cause of a smooth pursuit eye movement (SPEM) dysfunction in schizophrenia. We studied the voluntary control of saccades in schizophrenic patients with the SPEM dysfunction using an antisaccade task. The mean error rate in the antisaccade task was significantly higher in the two schizophrenic groups with and without a SPEM dysfunction than in the normal control group. Furthermore, the schizophrenic group with the SPEM dysfunction showed significantly more errors than the schizophrenic group without the SPEM dysfunction. These findings seem to suggest a close relationship between the SPEM dysfunction and the appearance of errors which indicates an inability to inhibit reflexive saccades voluntarily in the antisaccade task. However, 4 of 10 subjects with the SPEM dysfunction showed an error rate less than the mean error rate of the schizophrenic group without the SPEM dysfunction. So, a voluntary control disorder of saccades as the main cause of the SPEM dysfunction appeared to be unlikely. An interesting finding of this study was that many schizophrenic subjects with the SPEM dysfunction showed errors with the latencies similar to those in express saccades, particularly in the rightward direction. This finding may suggest a close relationship between the SPEM dysfunction in schizophrenic patients and some pathological conditions of express saccades such as disinhibition of express saccades.

Smooth pursuit eye movement dysfunction as a biological marker for prediction of disease courses of schizophrenia: a preliminary report

We investigated the relationship between a smooth pursuit eye movement (SPEM) dysfunction and long-term disease courses of schizophrenia. Many schizophrenic patients without the SPEM dysfunction tended to show an acute onset of illness, undulating courses and relatively good outcomes. On the other hand, patients with cogwheel-like SPEM dysfunction tended to show a chronic onset, simple courses, relatively severe outcomes and negative symptoms.

Defective concanavalin A-induced suppressor cell activity in lupus nephritis

To determine whether patients with systemic lupus erythematosus (SLE) and active nephritis have more profound defects in suppressor cell activity, we studied concanavalin A (Con A)-induced suppressor cell activity (SCA) in 12 patients with lupus nephritis (LN) and 11 patients with chronic mesangial proliferative glomerulonephritis (CGN) without renal insufficiency. The levels of Con A-induced SCA were decreased in patients with LN compared with those in normal controls and those in CGN patients and lower in LN patients with the nephrotic syndrome (NS) than in those without NS. In contrast, the mean responses of Con-A-induced SCA in CGN patients with or without NS did not differ from normal subjects. These findings may lend further insight into the understanding of the immunoregulatory defect in LN.

Defective cell-mediated immunity in lipoid nephrosis

Cell-mediated immunity (CMI) was studied in 28 patients with biopsy-proven lipoid nephrosis (LN). The LN patients with nephrotic syndrome (NS) had a significant depression in CMI, characterized by impaired delayed hypersensitivity skin reactivity to purified protein derivative (PPD), depressed local graft-versus-host reaction (GVHR), decreased proportion of T lymphocytes and diminished lymphocyte transformation to phytohemagglutinin (PHA). Concanavalin A (Con A)-induced suppressor cell activity (SCA) was found to be significantly increased in LN patients with NS compared to that in normal individuals. In contrast, the mean levels of CMI and SCA studied in LN patients in remission and in patients with chronic mesangial proliferative glomerulonephritis (CGN) did not differ from normal subjects. Our findings support the notion that at least in some LN patients with the NS, activated suppressor cells are present and possibly account for their decreased CMI.

Impaired delayed hypersensitivity in lipoid nephrosis

Cell-mediated immunity (CMI) was evaluated in 76 patients with renal disease by summation of delayed cutaneous hypersensitivity (DHS) responses to 4 test antigens, purified protein derivative (PPD), candida, mumps and keyhole limpet hemocyanin (KLH). Patients with lipoid nephrosis (LN) in the nephrotic stage had less mean induration of skin reactivity and a smaller proportion reacting to the former 3 antigens as compared with normal controls or LN patients without the nephrotic syndrome (NS). In contrast, the intensity of skin reactivity and the frequency of negative reactions in LN patients in remission and chronic mesangial proliferative glomerulonephritis (CGN) were similar to those of the control subjects. Immune response to KLH was also impaired in LN patients with the NS as measured by skin testing. The data indicate an impaired DHS in LN and suggest that the impairment relates to the clinical stage of disease.

Impaired cell-mediated immunity in focal glomerular sclerosis

Cell-mediated immunity (CMI) was evaluated in 8 patients with focal glomerular sclerosis (FGS), 50 patients suffering from chronic mesangial proliferative glomerulonephritis without renal insufficiency and 24 healthy controls. The following parameters were measured: delayed skin reactivity to purified protein derivative, circulating lymphocytes, lymphocyte cell-surface markers (neuraminidase-treated sheep erythrocyte and erythrocyte-antibody-complement rosettes) and functional markers (mitogenic responses to concanavalin A and phytohemagglutinin). The FGS patients with nephrotic syndrome (NS) had a significant depression in CMI, characterized by decreased responses of the lymphocytes to both concanavalin A and phytohemagglutinin, impaired delayed hypersensitivity to purified protein derivative and a decreased proportion of T lymphocytes as compared with normal subjects. In contrast, the levels of all CMI parameters studied in FGS patients in remission and in patients with chronic glomerulonephritis with or without NS did not differ from normal subjects. Thus, the majority of FGS patients with NS demonstrated an impaired response in a CMI assay system. The possible significance of these phenomena in the pathophysiology of FGS is discussed.

Leukocyte adherence inhibition test in renal diseases

Leukocyte adherence inhibition (LAI) test was examined in 35 patients with renal diseases and 14 normal controls, using collagenase-treated glomerular basement membrane, glycosidase-treated glomerular basement membrane and renal tubular epithelium as antigens. Although the control group showed strikingly similar mean LAI indices for all antigens tested, the whole group of patients with renal diseases showed a wide scatter of values. Two categories of patients had significantly increased LAI indices (p less than 0.01) when their mean values were compared with those of normal controls: (1) rapidly progressive glomerulonephritis (RPGN) and (2) lupus nephritis (SLE). In the serial studies of the RPGN and SLE cases, there were no significant changes in the pattern of LAI and they continued to give positive and very comparable results when re-examined at intervals of 1-6 months. Out of the 30 patients who were able to be evaluated with the three antigens, 15 cases exhibited positive LAI response to two or more antigens simultaneously. These in vitro findings suggest that there is an abnormal cellular response to certain antigen or widespread LAI reactivity to a variety of renal antigens in certain forms of human glomerulonephritis.

Concanavalin-A-induced suppressor cell activity in idiopathic membranous nephropathy

Suppressor cell activity (SCA) was analyzed in 8 patients with idiopathic membranous nephropathy (MN) and in 11 patients with chronic proliferative glomerulonephritis (CGN). We have assessed the ability of peripheral blood lymphocytes (PBL) stimulated by concanavalin A (Con A) to inhibit the proliferative response on normal allogenic lymphocytes by both Con A and phytohemagglutinin (PHA). It was found that the MN patients with nephrotic syndrome (NS) had significantly increased levels of suppression index (SI) when compared to the values obtained with normal controls. In contrast, the mean suppression values in the PBL from MN patients in remission and CGN patients with or without NS, whether the mitogen used was Con A or PHA, were similar to those of the control subjects. Thus, the majority of MN patients wih NS demonstrated an alteration in Con-A-induced SCA. The possible significance of these phenomena in the pathophysiology of MN is discussed.

Concanavalin A-induced suppressor cell activity in focal glomerular sclerosis

Suppressor cell activity (SCA) was analyzed in 8 patients with focal glomerular sclerosis (FGS) and 11 patients with chronic proliferative glomerulonephritis (CGN). We have assessed the ability of peripheral blood lymphocytes (PBL) stimulated by concanavalin A (Con A) to inhibit the proliferative response of normal allogeneic lymphocytes by both Con A and phytohemagglutinin (PHA). It was found that the FGS patients with nephrotic syndrome (NS) had significantly increased levels of suppression index when compared to the values obtained with normal controls. In contrast, the mean suppression values in the PBL from FGS patients in remission and CGN patients with or without NS, whether the mitogen used was Con A or PHA, were similar to those of the control subjects. Thus, the majority of FGS patients with NS demonstrated an alteration in Con A-induced SCA. The possible significance of these phenomena in the pathophysiology of FGS is discussed.

Concanavalin A-induced suppressor cell activity in lipoid nephrosis

Suppressor cell activity (SCA) was analysed in 28 patients with lipoid nephrosis (LN) and 11 patients with chronic proliferative glomerulonephritis (CGN). We have assessed the ability of peripheral blood lymphocytes (PBL) stimulated by concanavalin A (Con A) to inhibit the proliferative response of normal allogeneic lymphocytes by both Con A and phytohaemagglutinin (PHA). It was found that the LN patients in the earlier phase of relapse had significantly increased levels of suppression index (SI) were compared with the values obtained with normal controls. In contrast, the mean suppression values in the PBL from LN patients in remission and CGN patients with or without nephrotic syndrome, whether the mitogen used was Con A or PHA, were similar to those of the control subjects. Moreover, when individual patients were followed through their clinical illness, LN patients had high levels of SI, particularly in the beginning of acute exacerbations; the SI levels than decreased sharply in the latter phase of relapse and again increased to relatively normal levels with the onset of clinical remission. These in vitro findings suggest that there exists an alteration in Con A-induced SCA in a group of patients with LN.

Impaired cell-mediated immunity in lipoid nephrosis

Cell-mediated immunity (CMI) was evaluated in 26 patients with lipoid nephrosis (LN), 50 patients suffering from chronic diffuse proliferative glomerulonephritis (CGN) without renal sufficiency and 24 healthy controls. The following parameters were measured: delayed hypersensitivity skin test responses to purified protein derivative (PPD) and candida, circulating lymphocytes. T lymphocytes and T lymphocytes with receptors for the Fc portion of IgG (T gamma cells) or IgM (Tmu cells). Patients with LN in relapse had less mean induration of skin reactivity and a smaller proportion reacting to both antigens as compared with the control subjects. In contrast, the intensity of skin reactivity and the frequency of negative reactions in patients with LN in remission and CGN were similar to those of the control subjects. It was also found that the LN patients in relapse had a significant T lymphocytopenia as well as a significant decrease in absolute numbers of Tmu and T gamma cells, whereas the patients with LN in remission and CGN did not differ significantly from the control population. Thus, the majority of patients with LN in relapse demonstrated an impaired response in a CMI assay system. The disturbed CMI may be secondary to hypoproteinemia and other nutritional factors induced by the nephrotic syndrome.

Cell-mediated immunity in idiopathic membranous nephropathy

Cell-mediated immunity (CMI) was evaluated in 11 patients with idiopathic membranous nephropathy (MN), 50 patients suffering from chronic proliferative glomerulonephritis (CGN) without renal insufficiency and 24 healthy controls. The following parameters were measured: delayed skin reactivity to purified protein derivative (PPD), circulating lymphocytes, lymphocyte cell-surface markers (En and EAC rosettes) and functional markers (mitogenic responses to Con A and PHA). The MN patients with nephrotic syndrome (NS) had less mean induration of skin reactivity and a smaller proportion reacting to the PPD antigen as compared with the control subjects. In contrast, the intensity of skin reactivity and the frequency of negative reactions in MN patients in remission and CGN were similar to those of the control subjects. During the nephrotic stage of MN the proportion of T lymphocytes decreased with simultaneous increase of the proportion of B lymphocytes. It was also found that the MN patients with NS showed impaired lymphocyte reactivity with lower Con A and PHA responses compared to the normal controls. Conversely, the mean mitogenic responses to the antigens in patients with MN in remission and CGN were similar to those of the control subjects. Thus, the majority of MN patients with NS demonstrated an impaired response in a CMI assay system. The possible significance of these phenomena in the pathophysiology of MN is discussed.