The tumor autocrine motility factor receptor, gp78, is a ubiquitin protein ligase implicated in degradation from the endoplasmic reticulum

gp78, also known as the tumor autocrine motility factor receptor, is a transmembrane protein whose expression is correlated with tumor metastasis. We establish that gp78 is a RING finger-dependent ubiquitin protein ligase (E3) of the endoplasmic reticulum (ER). Consistent with this, gp78 specifically recruits MmUBC7, a ubiquitin-conjugating enzyme (E2) implicated in ER-associated degradation (ERAD), through a region distinct from the RING finger. gp78 can target itself for proteasomal degradation in a RING finger- and MmUBC7-dependent manner. Importantly, gp78 can also mediate degradation of CD3-delta, a well-characterized ERAD substrate. In contrast, gp78 lacking an intact RING finger or its multiple membrane-spanning domains stabilizes CD3-delta. gp78 has thus been found to be an example of a mammalian cellular E3 intrinsic to the ER, suggesting a potential link between ubiquitylation, ERAD, and metastasis.

Prediction of early tolerance to enteral feeding in preterm infants by measurement of superior mesenteric artery blood flow velocity

AIMS

To evaluate whether serial Doppler measurements of superior mesenteric artery (SMA) blood flow velocity after the first enteral feed could predict early tolerance to enteral feeding in preterm infants.

METHODS

When clinicians decided to start enteral feeds, Doppler ultrasound blood flow velocity in the SMA was determined before and after a test feed of 0.5 ml milk. The number of days taken for infants to tolerate full enteral feeding (150 ml/kg/day) was recorded.

RESULTS

Fourteen infants (group 1) achieved full enteral feeding within seven days. Thirty infants (group 2) took 8-30 days. There was no difference in the preprandial time averaged mean velocity (TAMV) between the groups at a median age of 3 (2-30) days. In group 1, there was a significant increase in TAMV (p<0.01) above the preprandial level at 45 and 60 minutes, but this did not occur in group 2. An increase in TAMV by more than 17% at 60 minutes has a sensitivity of 100% and a specificity of 70% for the prediction of early tolerance to enteral feeds.

CONCLUSIONS

There is a significant correlation between an increase in mean SMA blood flow velocity and early tolerance of enteral feeding. Doppler measurements of SMA blood flow velocity may be useful for deciding when to feed high risk preterm infants.

[Prevalent forecast of kiwifruit bacterial canker caused by Pseudomonas syringae pv. actinidiae]

The prevalent analysis of kiwifruit bacterial canker for several years showed that the effective ecological factors of severe degree were the precipitation (x1) in the second and last ten-days of March, and the average temperature (x2) of January. The model was y = 2.1359 + 0.0107x1 - 0.6061x2. The main factor of the prevalence was the relative variation of ten-days average temperature and precipitation in Winter and in early Spring, and the regression equation was y = -8.127 + 22.739x - 13.254x2. The forecast effect of the equation was obviously significant after testing.

[Ecological factors affecting prevalence of kiwifruit bacterial canker and bacteriostatic action of bacteriocides on Pseudomonas syringae pv. actinidae]

According to the systematic study for 5 years, this paper dealt with the ecological factors affecting prevalence of kiwifruit bacterial canker. The disease was more serious in the orchards with above 750 m in elevation, and more serious at mountain slope facing south than facing north. Incidence differed significantly among cultivars, with easy disease infection for Jinfeng, and strong disease resistance for Jinkui. The older the trees, the more the diseased plants. The one year old twigs had highest death twig incidence of diseased twigs and death twig incidence than other twigs. Among 6 tested bacteriocides, Jiaruinong and streptomycin showed best bacteriostatic effect.

Identification of rice black-streaked dwarf fijivirus in maize with rough dwarf disease in China

Three virus isolates from maize with rough dwarf in different provinces in China were analyzed at the molecular level. When compared to an isolate from diseased rice plants in Hubei Province, all four isolates had identical genomic RNA electrophoretic profiles, which were composed of ten double-stranded (ds) RNAs. Full-length cDNAs of segment 10 (S10) from each of the four isolates were cloned by RT-PCR and the complete sequences were determined. Analysis of the sequences revealed that each consisted of 1801 nucleotides and contained a single open reading frame (ORF) which potentially encoded a protein with 558 amino acids. Further, the sequences showed more than 97.0% and 98.0% identity at nucleotide and amino acid levels, respectively. In addition, their identities to rice black-streaked dwarf virus S10 were significantly higher than those to maize rough dwarf virus S10. Based on these results, it is suggested that the virus which causes this maize disease in China is rice black-streaked dwarf virus.

Three-dimensional imaging of embryonic mouse kidney by two-photon microscopy

Developing mammalian embryonic kidney becomes progressively more elaborate as the ureteric bud branches into undifferentiated mesenchyme. Morphological perturbations of nephrogenesis, such as those seen in inherited renal diseases or induced in transgenic animals, require careful and often tedious documentation by multiple methodologies. We have applied a relatively quick and simple approach combining two-photon microscopy and advanced three-dimensional (3-D) imaging techniques to visualize and evaluate these complex events. As compared with laser confocal microscopy, two-photon microscopy offers superior optical sectioning deep into biological tissues, permitting analysis of large, heterogeneous, 3-D structures such as developing mouse kidney. Embryonic and newborn mouse kidneys were fluorescently labeled with lectins, phalloidin, or antibody. Three-dimensional image volumes were then collected. The resulting volume data sets were processed using a novel 3-D visualization technique. Reconstructed image volumes demonstrate the dichotomous branching of ureteric bud as it progresses from a simple, symmetrical structure into an elaborate, asymmetrical collecting system of multiple branches. Detailed morphology of in situ cysts was elucidated in a transgene-induced mouse model of polycystic kidney disease. We expect this integration of two-photon microscopy with advanced 3-D image analysis will provide a powerful tool for illuminating a variety of complex developmental processes in multiple dimensions.

Effects of gas adsorption and collisions on electrical transport in single-walled carbon nanotubes

Degassing of bundles of single-walled carbon nanotubes in vacuum at 500 K is found to drive the thermoelectricpower (TEP) strongly negative, indicating that the degassed metallic tubes in a bundle are n type. The magnitude of the negative TEP indicates that important asymmetry in the electronic carbon pi bands exists near the Fermi energy. Easily measurable increases in the TEP ( approximately 5-10 &mgr;V/K) and resistivity ( 2%-10%) are observed at 500 K upon exposure to N2 and He, suggesting that even gas collisions with the nanotube wall can contribute significantly to the transport properties.

Three-dimensional microscopy data exploration by interactive volume visualization

This paper presents a new volume visualization approach for three-dimensional (3-D) interactive microscopy data exploration. Because of their unique image characteristics, 3-D microscopy data are often not able to be visualized effectively by conventional volume visualization techniques. In our approach, microscopy visualization is carried out in an interactive data exploration environment, based on a combination of interactive volume rendering techniques and image-based transfer function design methods. Interactive volume rendering is achieved by using two-dimensional (2-D) texture mapping in a Shear-Warp volume rendering algorithm. Image processing techniques are employed and integrated into the rendering pipeline for the definition and searching of appropriate transfer functions that best reflect the user's visualization intentions. These techniques have been implemented successfully in a prototype visualization system on low-end and middle-range SGI desktop workstations. Since only 2-D texture mapping is required, the system can also be easily ported to PC platforms.

Ubiquitin protein ligase activity of IAPs and their degradation in proteasomes in response to apoptotic stimuli

To determine why proteasome inhibitors prevent thymocyte death, we examined whether proteasomes degrade anti-apoptotic molecules in cells induced to undergo apoptosis. The c-IAP1 and XIAP inhibitors of apoptosis were selectively lost in glucocorticoid- or etoposide-treated thymocytes in a proteasome-dependent manner before death. IAPs catalyzed their own ubiquitination in vitro, an activity requiring the RING domain. Overexpressed wild-type c-IAP1, but not a RING domain mutant, was spontaneously ubiquitinated and degraded, and stably expressed XIAP lacking the RING domain was relatively resistant to apoptosis-induced degradation and, correspondingly, more effective at preventing apoptosis than wild-type XIAP. Autoubiquitination and degradation of IAPs may be a key event in the apoptotic program.

Development of a transgenic mouse that overexpresses a novel product of the growth hormone-releasing hormone gene

The GH-releasing hormone (GHRH) precursor molecule contains a 30-amino acid C-terminal region that has been designated GHRH-related peptide (GHRH-RP). To begin to understand the physiological role of GHRH-RP, transgenic (Tg) mice that constituitively express this peptide were developed. To generate these mice, a transgene (SS-RP) was constructed by overlap primer extension PCR. This transgene, under the control of the mouse phosphoglycerate kinase gene, selectively expresses GHRH-RP, but not GHRH. Western blot analysis confirmed that the transgene produces GHRH-RP. Animals were evaluated for the effect of excess GHRH-RP on growth, fertility, behavior, stem cell factor (SCF) expression, and hematopoiesis. Northern blot and RT-PCR were used to demonstrate ubiquitous expression of the transgene in tissues from GHRH-RP Tg animals. These tissues also had marked overexpression of SCF messenger RNA compared with controls. Tg animals had significantly increased cell cycling for granulocyte-macrophage, erythroid, and multilineage progenitor cells. Transgenic animals did not differ from control mice in their growth, fertility, or behavior. These findings demonstrate, for the first time, that in vivo the C-terminal peptide of the pro-GHRH molecule is a biologically active peptide that is capable of stimulating the expression of SCF and hematopoiesis in vivo and suggests that GHRH-RP may play a role in normal blood cell development.

Novel rearranged ions observed for protonated peptides via metastable decomposition in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

C-terminal rearrangement ions [b(n-1) + H2O] (where n refers to the total number of residues of peptides) are frequently observed for peptides which contain basic amino acid(s), especially arginine, at or near their N termini in low- and high-energy collision-induced dissociation or post-source decay (PSD) spectra. Here we report a novel rearrangement, associated with PSD for serine- or threonine-containing peptides that are susceptible to C-terminal rearrangement. Based on PSD analyses of serine- or threonine-containing bradykinin and its analogs, which have been ethyl-esterified or 18O labeled at their C termini, the [b(k) + H2O] (where k denotes the position adjacent to the left of the Ser/Thr residue) ion is generally thought to be formed by the transfer of the hydroxyl moiety of a serine or threonine residue to the carbonyl group of the residue to its left accompanied by the loss of the remaining C-terminal portion of the peptide. When the Ser/Thr is at or near the C terminus, the present [b(k) + H2O] ion could be formed via two pathways, i.e., the Ser/Thr-related rearrangement and the conventional C-terminal rearrangement, which has been clearly verified by 18O labeling at the C terminus. In addition, the ions which are formally designated as [y(m)b(l) + H2O], where y(m)b(l) denotes a b-type internal ion, are also briefly described.

[Synergic effects on primary hepatocellular cancer between history of hepatitis B, family histories of cancers and psychosocial factors]

To study the risk factors of primary hepatocellular cancer (PHC) and their interactions, a case-control study with calculated odds ratios(OR) and synergy effects index(SI) was conducted. The history of hepatitis B, family histories of cancers and psychosocial factors were main risk factors of PHC, and their effects were positive and synergic. The SI between hepatitis B and family histories of cancers, psychosocial factors are 1.65 and 1.16 respectively.

Mdm2 is a RING finger-dependent ubiquitin protein ligase for itself and p53

Mdm2 has been shown to regulate p53 stability by targeting the p53 protein for proteasomal degradation. We now report that Mdm2 is a ubiquitin protein ligase (E3) for p53 and that its activity is dependent on its RING finger. Furthermore, we show that Mdm2 mediates its own ubiquitination in a RING finger-dependent manner, which requires no eukaryotic proteins other than ubiquitin-activating enzyme (E1) and an ubiquitin-conjugating enzyme (E2). It is apparent, therefore, that Mdm2 manifests an intrinsic capacity to mediate ubiquitination. Mutation of putative zinc coordination residues abrogated this activity, as did chelation of divalent cations. After cation chelation, the full activity could be restored by addition of zinc. We further demonstrate that the degradation of p53 and Mdm2 in cells requires additional potential zinc-coordinating residues beyond those required for the intrinsic activity of Mdm2 in vitro. Replacement of the Mdm2 RING with that of another protein (Praja1) reconstituted ubiquitination and proteasomal degradation of Mdm2. However, this RING was ineffective in ubiquitination and proteasomal targeting of p53, suggesting that there may be specificity at the level of the RING in the recognition of heterologous substrates.

Phylogeny and evolution of the Drosophila nasuta subgroup based on mitochondrial ND4 and ND4L gene sequences

The sequences of the mitochondrial ND4 gene (1339 bp) and the ND4L gene (290 bp) were determined for all the 14 extant taxa of the Drosophila nasuta subgroup. The average A + T content of ND4 genes is 76.5% and that of ND4L genes is 83.5%. A total of 114 variable sites were scored. The ND4 gene sequence divergence ranged from 0 to 5.4% within the subgroup. The substitution rate of the ND4 gene is about 1.25% per million years. The base substitution of the genes is strongly transition biased. Neighbor-joining and parsimony were used to construct a phylogeny based on the resultant sequence data set. According to these trees, five distinct mtDNA clades can be identified. D. niveifrons represents the most diverged lineage. D. sulfurigaster bilimbata and D. kepulauana form two independent lineages. The other two clades are the kohkoa complex and the albomicans complex. The kohkoa complex consists of D. sulfurigaster sulfurigaster, D. pulaua, D. kohkoa, and Taxon-F. The albomicans complex can be divided into two groups: D. nasuta, D. sulfurigaster neonasuta, D. sulfurigaster albostrigata, and D. albomicans from Chiangmai form one group; and D. pallidifrons, Taxon-I, Taxon-J, and D. albomicans from China form the other group. High genetic differentiation was found among D. albomicans populations. Based on our phylogenetic results, we hypothesize that D. niveifrons diverged first from the D. nasuta subgroup in Papua New Guinea about 3.5 Mya. The ancestral population spread to the north and when it reached Borneo, it diversified sequentially into the kohkoa complex, D. s. bilimbata, and D. kepulauana. About 1 Mya, another radiation occurred when the ancestral populations reached the Indo-China Peninsula, forming the albomicans complex. Discrepancy between morphological groupings and phylogenetic results suggests that the male morphological traits may not be orthologous.

RING fingers mediate ubiquitin-conjugating enzyme (E2)-dependent ubiquitination

A RING finger-containing protein (AO7) that binds ubiquitin-conjugating enzymes (E2s) and is a substrate for E2-dependent ubiquitination was identified. Mutations of cation-coordinating residues within AO7's RING finger abolished ubiquitination, as did chelation of zinc. Several otherwise-unrelated RING finger proteins, including BRCA1, Siah-1, TRC8, NF-X1, kf-1, and Praja1, were assessed for their ability to facilitate E2-dependent ubiquitination. In all cases, ubiquitination was observed. The RING fingers were implicated directly in this activity through mutations of metal-coordinating residues or chelation of zinc. These findings suggest that a large number of RING finger-containing proteins, with otherwise diverse structures and functions, may play previously unappreciated roles in modulating protein levels via ubiquitination.

Antigenic epitopes of the hepatitis A virus polyprotein

Forty-two antigenic domains were identified across the hepatitis A virus (HAV) polyprotein by using a set of 237 overlapping 20-mer synthetic peptides spanning the entire HAV polyprotein and a panel of serum samples from acutely HAV-infected patients. The term "antigenic domain" is used in this study to define a protein region spanned with consecutive overlapping immunoreactive peptides. Nineteen antigenic domains were found within the structural proteins, and 22 were found within the nonstructural proteins, with 1 domain spanning the junction of VP1 and P2A proteins. Five of these domains were considered immunodominant, as judged by both the breadth and the strength of their immunoreactivity. One domain is located within the VP2 protein at position 57-90 aa. A second domain, located at position 767-842 aa, contains the C-terminal part of the VP1 protein and the entire P2A protein. A third domain, located at position 1403-1456 aa, comprises the C-terminal part of the P2C protein and the N-terminal half of the P3A protein. The fourth domain, located at position 1500-1519 aa, includes almost the entire P3B, and the last domain, located at position 1719-1764 aa, contains the C-terminal region of the P3C protein and the N-terminal region of the P3D protein. It is interesting to note that four of the five most immunoreactive domains are derived from small HAV proteins and/or encompass protein cleavage sites separating different HAV proteins. The HAV-specific immunoreactivity of each antigenically reactive peptide was confirmed by using seven HAV seroconversion panels. Collectively, these data demonstrate that HAV structural and nonstructural proteins contain antigenic epitopes that can be efficiently modeled with short synthetic peptides.

NOS gene transfer inhibits expression of cell cycle regulatory molecules in vascular smooth muscle cells

The mechanisms of nitric oxide (NO)-mediated inhibition of vascular smooth muscle (VSM) cell proliferation are still obscure. Cyclins A and E in association with cyclin-dependent kinase 2 (cdk2) serve as positive regulators for mammalian cell cycle progression through the G1/S checkpoint of the cell cycle and subsequent cell proliferation. Therefore, we have tested the effect of adenovirus-mediated transfection of the endothelial nitric oxide synthase (eNOS) gene into guinea pig coronary VSM cells on platelet-derived growth factor (BB homodimer) (PDGF-BB)-stimulated cell proliferation and the expression of cell cycle regulatory molecules. Transfection of the eNOS gene (eNOS) into VSM cells significantly inhibited (P < 0.05) [3H]thymidine incorporation into the DNA in response to PDGF-BB stimulation compared with lacZ-transfected control cells. The eNOS transfer significantly inhibited (P < 0.05) PDGF-BB-induced proliferating cell nuclear antigen (PCNA) and cyclin A expression in VSM cells compared with cells transfected with the control vector. The time course of cyclin E expression in response to PDGF-BB stimulation was delayed in eNOS-transfected cells. Levels of cyclin-dependent kinase inhibitors p21 and p27 were not significantly affected by eNOS transfer. eNOS transfer did not decrease PDGF-beta receptor number, affinity, and autophosphorylation measured by radioreceptor assay and Western analysis. These results suggest that inhibition of PDGF-stimulated expression of cyclin A, cyclin E, and PCNA is the target of NO action. These findings could explain, at least in part, NO-mediated inhibition of VSM cell proliferation.

[Cloning and sequence characterization of heavy chain variable region gene from hybridoma cells secreting MAB against VEGF]

OBJECTIVE

To clone the variable region of heavy chain (VH) gene from hybridoma secreting monoclonal antibody against human vasoendothelial growth factor (VEGF) for construction of recombinant antibody (scFv).

METHODS

One step method was used to extract total RNA and degeneration primer was used to amplify the cDNAs by retropolymerase chain reaction (RT-PCR), then the products were inserted to T-vector and its sequence was analysed.

RESULTS

The VH gene contained 369 base pairs encoding 123 amine acid resides. Analysis of the nucleotide sequence of the light chain variable region revealed that the VH sequence was 87% identical to the sequence present in mouse Ig VH region.

CONCLUSION

The VH gene was 369 bp. According to Kabat classification, the VH gene belonging to mouse kappa light chains subgroup I (A), resulting from VH-D-JH4 rearrangment.

Application of Electrospray Ionization Mass Spectrometry Combined with Sequential Tandem Mass Spectrometry Techniques for the Profiling of Steroidal Saponin Mixture Extracted from Tribulus terrestris

Using electrospray ionization mass spectrometry combined with sequential tandem mass spectrometry (ESI-MS (n)), the steroidal saponin mixture extracted from TRIBULUS TERRESTRIS was studied. The structures of five known steroidal saponins and two unknown steroidal saponins in the saponin mixture were investigated by sequential tandem mass spectrometry experiments. All of the steroidal saponins displayed similar fragmentation behavior in ESI-MS (n), and the characteristic cross ring cleavage pattern could be used as a fingerprint for the identification of steroidal saponins. The methodology has been established as a powerful tool for the profiling of mixtures, especially of crude plant extracts, and the structural elucidation of compounds.

[Design and synthesizing of human vascular endothelial growth factor (VEGF) peptide]

OBJECTIVE

To predict continuous epitopes of VEGF using synthetic peptide of VEGF as antigen to produce anti-VEGF-peptide monoclonal antibody.

METHODS

According to amino sequence of VEGF189, antigen index program and Goldkey soft were used to predict VEGF epitopes, and the peptide containing one of predicted epitopes was synthesized by 430A Peptide Synthesizer.

RESULTS

The NH2-terminal 1-26 amino acid sequence of VEGF was determined as synthetic peptide and synthesized.

CONCLUSION

The predicted epitope of VEGF was synthesized, which provided an effective method when lacking of VEGF.

Binding and uptake of cationic lipid:pDNA complexes by polarized airway epithelial cells

To better understand the barriers associated with cationic lipid-mediated gene transfer to polarized epithelial cells, Fischer rat thyroid (FRT) cells and polarized normal human bronchial epithelial (NHBE) cells grown on filter supports at an air-liquid interface were used to study the binding and uptake of cationic lipid:plasmid DNA (pDNA) complexes. The efficiencies of binding and uptake of cationic lipid:pDNA complexes by these cell systems were monitored using fluorescence microscopy of fluorescently tagged lipid or pDNA probes. Fluorescent probe bound to the cell surface was differentiated from internalized probe by adding trypan blue, which quenched the fluorescence of bound but not internalized probes. For proliferating cells, binding and internalization of the cationic lipid:pDNA complexes were determined to be efficient. In contrast, little binding or internalization of the complexes was observed using polarized epithelial cells. However, after aspirating a small area of cells from the filter support, virtually all of the cells adjoining this newly formed edge bound and internalized the cationic lipid:pDNA complexes. To determine if their uptake in edge cells was related to the ability of the complexes to access the basolateral membranes of these cells, the binding and uptake of complexes was monitored in polarized NHBE cells that had been pretreated with EGTA or Ca2+-free media, strategies known to disrupt tight junctions. Cells treated in this manner bound and internalized cationic lipid:pDNA complexes efficiently and also expressed significant levels of transgene product. Control cells with intact tight junctions neither bound complexes nor expressed significant transgene product. These data confirm and extend earlier observations that the polarized apical membranes of airway epithelial cells are resistant to transfection by lipid:pDNA complexes. Further, in contrast to previous studies that have shown the entry step of complexes is not an important barrier for COS and HeLa cells, binding and entry of complexes in polarized NHBE cells appear to be rate limiting. These findings suggest that strategies designed to open the tight junctions of polarized epithelial cells may improve gene delivery to these cells for diseases such as cystic fibrosis (CF).

Enhanced recovery of injury-caused downregulation of paxillin protein by eNOS gene expression in rat carotid artery. Mechanism of NO inhibition of intimal hyperplasia?

Injury-caused dedifferentiation accompanied by proliferation and migration of smooth muscle cells (SMCs) is an important process in the development of the neointima. Nitric oxide (NO) stimulates differentiation and inhibits proliferation and migration of SMCs. Paxillin has been found to play an important role in cell differentiation, and its phosphorylation is regulated by NO in cultured SMCs. However, the regulation of paxillin by NO in the injured artery has not been investigated. Therefore, the aim of this study was to study the effects of in vivo endothelial NO synthase (eNOS) gene transfection on paxillin expression and intimal hyperplasia. A catheter balloon-denuded rat carotid artery was transfected in vivo with the replication-deficient adenovirus Ad5/RSVeNOS or with Ad5/RSVLacZ as the control. Transfected eNOS gene expression was determined by immunostaining, Western blot analysis, and citrulline assay. The expression of paxillin and its associated proteins was determined in injured arteries by Western blot analysis. The area of the intima and the ratio of intima to media were examined on cross sections by morphometry. The data showed that the expression of paxillin was significantly downregulated after injury. eNOS gene transfer showed no effect on paxillin downregulation 2 days after injury but significantly enhanced the recovery of paxillin protein 5 days and 2 weeks after injury. Vinculin, a paxillin-binding protein, was not altered by vascular injury or by eNOS gene transfer. eNOS gene transfer significantly inhibited intimal hyperplasia for up to 4 weeks. These results suggest that NO inhibition of intimal hyperplasia may be mediated by enhancing the recovery of injury-caused downregulation of paxillin.

[Repair of soft tissue defect of heel with myocutaneous flap of flexor digitorum brevis]

OBJECTIVE

To investigate the repairing method of soft tissue defect of heel, pedicled island myocutaneous flap of flexor digitorum brevis was designed.

METHODS

From 1984 to 1997, 26 cases with soft tissue defect of heel were adopted in the clinical trial. Among them, the were 18 males, 8 females and the age ranged from 15 to 60 years old. The area of wound ranged from 2.5 cm x 1.5 cm to 8.0 cm x 6.0 cm.

RESULTS

After operation, all of the flaps survived. They were followed up for 9 to 72 months. All of the flaps had primary healing except in one there was infection of peripheral of the flap. The contour of heel was satisfactory the sensation of flap was good and the weight-bearing function was also successful.

CONCLUSION

It was concluded that the myocutaneous flap of flexor digitorum brevis could be used to repair the soft tissue defect of heel because of its nearby position, hidden location, good recovery of skin sensation and weight-bearing function, Besides, the procedure of this operation was simple and the anti-inflammatory potential of the flap was high. However, Because of the limited donor area, the pre-operative design was important.

Acute metabolic response to high-carbohydrate, high-starch meals compared with moderate-carbohydrate, low-starch meals in subjects with type 2 diabetes

OBJECTIVE

The monosaccharides resulting from the digestion of ingested carbohydrates are glucose, fructose, and galactose. Of these three monosaccharides, only ingested glucose resulted in a large increase in the plasma glucose concentration. Fructose (Metabolism 41:510-517, 1992) and galactose (Metabolism 42:1560-1567, 1993) had only a minor effect. Therefore, we were interested in determining whether we could design a mixed meal, using foods of known monosaccharide, disaccharide, and starch composition, the ingestion of which would result in only a small rise in plasma glucose concentration.

RESEARCH DESIGN AND METHODS

The experimental meal was composed of very little readily digestible starch but rather large amounts of fruits and vegetables. It contained 43% carbohydrate, 22% protein, and 34% fat. The results were compared with a second type of meal that contained 55% carbohydrate, 15% protein, and 30% fat, with an emphasis on complex carbohydrates (starch). It also was compared with a third meal that contained 40% carbohydrate, 20% protein, and 40% fat, typical of that consumed by the average American. The test meals were ingested in random order by people with type 2 diabetes who were not treated with oral hypoglycemic agents or insulin. Each subject ingested each type of meal. The same identical meal was ingested at 0800, 1200, and 1700.

RESULTS

The integrated 24-h plasma glucose area response was statistically significantly smaller (P < 0.05) after ingestion of the low-starch meals compared with the high-starch, high-carbohydrate meals or the typical American meals. The 24-h integrated serum insulin area response also was statistically significantly less (P < 0.05) after ingestion of the low-starch meals compared with the high-starch meals or the typical American meals. The serum triglyceride area response was similar after ingestion of all three test diets.

CONCLUSIONS

A diet in which fruits, nonstarch vegetables, and dairy products are emphasized may be useful for people with type 2 diabetes.

Immunogenicity of Plasmodium falciparum and Plasmodium vivax circumsporozoite protein repeat multiple antigen constructs (MAC)

In this study we characterized the immunogenic properties of three different multispecies multiple antigen constructs (MACs) carrying the circumsporozoite protein (CSP) repeats of human malaria parasites, Plasmodium falciparum and P. vivax. We synthesized tetrameric MACs containing the antigenic repeats from the CSP of P. vivax-like parasite in two arms and CSP repeat sequences of either P. vivax type-1 (vivax-like/vivax type-1 MAC), P. vivax type-2 (vivax-like/vivax type-2 MAC), or P. falciparum (vivax-like/falciparum MAC) in the other two arms. Mice of four different genetic backgrounds (H-2a, H-2b, H-2d, and H-2k) were immunized with these MACs in Freund's adjuvant. All three MAC preparations were found to elicit antibodies to P. vivax-like CSP repeats in B10.BR, B10.A, and C57BL/6 mice. On the other hand, in B10.D2 mice only vivax-like/vivax type-1 MAC, but not the other two MACs induced antibodies to the P. vivax-like CSP repeats. In mice immunized with vivax-like/vivax type-1 MAC, antibodies to P. vivax type-1 CS repeat peptides were induced in B10.BR, B10.A, and C57BL/6 mice, but not in B10.D2 mice. Antibody responses to P. vivax type-2 repeats were not induced in any of the four strains of mice that were immunized with vivax-like/vivax type-2 MAC. While B10.BR, B10.A, and C57BL/6 mice produced antibodies to NANP repeats of P. falciparum CSP following immunization with vivax-like/falciparum MAC, B10.D2 mice failed to elicit antibodies to this repeat. All the sera that showed positive reactivity to peptides in enzyme-linked immunosorbent assay were found to react with sporozoites by IFA. In conclusion, these results showed that naturally immunogenic epitopes from different species of malaria parasites can be incorporated in a single vaccine construct to induce immune responses against multiple epitopes.

Comparison of the effects of theophylline and caffeine on serum erythropoietin concentration in premature infants

Theophylline administration has been shown to attenuate erythropoietin (EP) production in adults; the effect of caffeine is not known. Our aim was to determine whether caffeine and theophylline had similar effects on EP production in the premature newborn. If caffeine was found to have a greater effect, this would influence prescribing habits. Fifty preterm infants (mean gestational age 28 weeks) who had clinically significant apnoea were randomized to receive theophylline (4 mg/kg then 2 mg/kg twice daily) or caffeine (10 mg/kg then 2.5 mg/kg once daily). The methylxanthines were continued at least until discharge from the NICU and the dosage altered to keep the levels within the therapeutic range. As an assessment of EP production, serum EP concentrations were measured. Blood for EP, haemoglobin, reticulocyte count, theophylline and caffeine levels was obtained prior to treatment and at least during weeks 3 and 7. There was no significant difference in the mean EP level in the two groups taken prior to treatment at a median age of 2 days of life. There were similar falls in haematocrit and haemoglobin in the two groups during the study period compared to pre-treatment values. At that time, however, the median reticulocyte count was higher in the caffeine compared to the theophylline treated infants (P < 0.05). This was associated with a rise compared to baseline (median 10.0-0.2 mU/ml) in the mean EP levels in the caffeine group and a decrease from a median of 10.1 to 8.3 mU/ml in the theophylline group, but the EP levels in the two groups at week 7 did not differ significantly.

CONCLUSION

These results suggest that caffeine does not have a greater impact than theophylline on EP production.

A study of glycoconjugates in nasopharyngeal carcinoma with correlation to clinical transformation

Little is known about the glycoconjugate changes in human nasopharyngeal epithelium following neoplastic changes. Glycoconjugate histochemistry (Glycine maximus (SBA), Griffonia simplicifolia II (GSA-II), Ulex europaeus (UEA-I), Arachis hypogaea (PNA) and Canavalia ensiformis (ConA)) were performed on the following nasopharyngeal biopsies: 10 adenoid tissues (benign controls), 10 chronic inflammation, 20 squamous metaplasia, 20 undifferentiated carcinoma and 5 squamous cell carcinoma. These results were correlated with the clinical transformations findings. Strong ConA and PNA staining (after neuraminidase treatment (NA)) characterized a subpopulation of squamous metaplasia subjects who later transformed to nasopharyngeal carcinoma. Strong ConA and PNA (before and after NA) depicted the majority of undifferentiated carcinoma subjects having local recurrence following irradiation therapy. In squamous metaplasia, ConA and PNA (after NA) staining may serve as a warning sign for neoplastic changes. Strong stainings for ConA and PNA (before and after NA) in undifferentiated carcinoma subjects may predict a risk for local recurrence.

Clinical study on chronopharmacokinetics of digoxin in patients with congestive heart failure

Fluorescence polarization immunoassay was used to study the chronopharmacokinetics of digoxin in 10 patients with congestive heart failure (CHF) who also served as self-controls. Our results showed that the serum digoxin concentration reached peak value 1 h after taking digoxin at 7:00 a.m., but the serum digoxin concentration reached the peak value 2 h after taking digoxin at 4:00 p.m. The average serum digoxin concentration area under curve was greater and the best maintainable time of serum concentration within 24 h after taking digoxin at 4 p.m. longer than those at 7:00 a.m. The heart rates were obviously lower and the cardiac function was significantly improved in 4:00 p.m. group.

Rapid analysis of steroidal saponin mixture using electrospray ionization mass spectrometry combined with sequential tandem mass spectrometry

Using electrospray ionization mass spectrometry (MS) combined with sequential tandem MS(ESI-MSn), two major steroidal saponins extracted from Tribulus terrestris were studied, and considerable useful structural information was obtained. The structure of the proposed known steroidal saponin was verified, and the structure of the unknown saponin was investigated using MSn experiments. Some special fragment ions were also observed, and the corresponding fragmentation mechanisms were investigated which are characteristic for steroidal saponins and can give some information on the linkage position of some sugar groups in saponins. This methodology has been established as a powerful tool for the rapid, comparative analysis of mixtures such as crude plant extracts.

[The effect of antisense human Fas RNA on activation induced apoptosis of T cell]

OBJECTIVE

To explore an approach to the reduction of activation induced apoptosis of T cell so as to maximize the number of CTL and enhance the tumor cytotoxicity.

METHODS

CD3-induced Jurkat cell line was used as the activated T cell apoptosis model,and the antisense Fas cDNA was introduced into Jurkat cells with retroviral vector.

RESULTS

The expression level of Fas protein in Jurkat cells transducted with the retroviral vector was decreased. Apoptosis was reduced in antisense Fas-transfected Jurkat cells after anti-CD3 or anti-Fas treatment.

CONCLUSION

Antisense blocking of Fas expression can partially inhibit Jurkat cell apoptosis induced by anti-CD3 or anti Fas.

[Investigation of potency to produce interleukin-2 of the peripheral blood T lymphocytes in patients with hemorrhagic stroke]

For further understanding the changes in immune function of the patients with hemorrhagic stroke, we investigated the activity of interleukin-2 (IL-2) in the peripheral blood T lymphocytes from 32 patients. The results showed that the levels of IL-2 in the patients were lower than those of the healthy controls, but no significant difference was observed between the cerebral hemorrhage group and subarachnoid hemorrhage group. It suggests the cellular immune function of patients at the acute period is low. We consider that IL-2 might be of use as a kind of therapeutic measure to modulate patients' immune function and treat the diseases.

Endothelial nitric oxide synthase gene transfer inhibits platelet-derived growth factor-BB stimulated focal adhesion kinase and paxillin phosphorylation in vascular smooth muscle cells

Stimulation of smooth muscle (VSM) cells of guinea pig coronary artery by platelet-derived growth factor (PDGF)-BB retards paxillin mobility (mobility shift) in SDS-PAGE in a time-dependent manner. This mobility shift may be due to tyrosine phosphorylation of paxillin. eNOS gene transfer by replication deficient recombinant adenovirus vector AD5/RSVeNOS in VSM cells inhibited PDGF-BB-stimulated mobility shift and tyrosine phosphorylation of paxillin. Concomitantly, tyrosine phosphorylation of focal adhesion kinase (FAK) was also inhibited. The inhibition of paxillin and FAK tyrosine phosphorylation did not affect stress fiber and focal adhesion formation. Considering the importance of FAK and paxillin in cell migration and proliferation, these results suggest that the FAK-paxillin pathway is a target for NO action to inhibit VSM cell migration and proliferation.

[Antioxidation of Pueraria lobata isoflavones (PLIs)]

Isoflavones are isolated from Pueraria lobata. By studyign Pueraria lobata isoflavones (PLIs) on lipid peroxide (LPO) and superoxide dismutase (SOD) in animal tissue, this paper suggests that PLIs is an effective antioxidant. The results in vitro show that PLIs can inhibit significantly the content of LPO. The highest inbibition rate are found to be 79.7%, 84.7%, and 86.6% in liver, kidney of mice and brain of rabbit respectively. By cold induced brain injury with chalcone, the content of LPO and activity of SOD in animal blood and brain are changed. When animals are injected with PLIs, the result indicates that the PLIs can reduce significantly the content of LPO and enhance the activity of SOD in animal blood and brain, in a dose-dependent relationship.

The role of antioxidant enzymes in the control of opossum sphincter of Oddi motility

Superoxide rapidly oxidizes nitric oxide (NO) to form peroxynitrite, thus terminating the biological activity of NO. The aims of our study were to determine if superoxide alters the motor function of the sphincter of Oddi and to localize the antioxidant enzymes in the sphincter of Oddi. Immunostaining was performed and enzyme activities were measured in the sphincter of Oddi. In physiological experiments, force-displacement transducers recorded tension in the spontaneously contracting sphincter of Oddi and after electrical field stimulation (EFS) of precontracted sphincter of Oddi. Superoxide was generated by the addition of xanthine with xanthine oxidase, superoxide radicals were scavenged by the addition of superoxide dismutase (SOD), and catalase or SOD was inhibited by diethyldithiocarbamic acid. Immunostaining demonstrated SOD and catalase immunoreactivity in ganglia situated at the serosal surface of the circular muscle. Total SOD activity was 202 +/- 12 U/mg. Generation of superoxide or inhibition of SOD increased the contractile frequency and decreased relaxation after EFS. We conclude that superoxide alters sphincter of Oddi motor function, and the presence of superoxide scavenging enzymes in enteric plexuses suggests that they may regulate sphincter of Oddi neuromuscular function by clearing endogenous superoxide.

Multiple antigen constructs (MACs): induction of sterile immunity against sporozoite stage of rodent malaria parasites, Plasmodium berghei and Plasmodium yoelii

We prepared multiple antigen constructs (MACs) using circumsporozoite (CS) protein-based B-epitopes from Plasmodium berghei, (PPPPNPND)2 and Plasmodium yoelii, (QGPGAP)3QG, along with a P. berghei T-helper epitope KQIRDSITEEWS. Mice were immunized with individual MACs in oil-in-water or water-in-oil vehicles containing block copolymer (P1005) and detoxified RaLPS (RaLPS) as well as other adjuvants. Sporozoite challenge results demonstrated that MACs in adjuvant could induce antibodies capable of active and passive protection. Water-in-oil vaccines induced the highest level of protection in mice immunized with either P. berghei or P. yoelii MACs. In a study aimed at co-eliciting immunity against P. berghei and P. yoelii, three immunizations with MACs induced protective antibodies against P. berghei but not P. yoelii parasite challenge. Therefore, it can be concluded that individually MACs are capable of inducing strong and protective immune responses to either species of rodent malaria, and that protection can be passively transferred. When MAC formulations were used together as a combined vaccine, P. berghei MACs induced a strong protective antibody response while P. yoelii MACs induced a weaker nonprotective response.

Induction of protective antibodies in Saimiri monkeys by immunization with a multiple antigen construct (MAC) containing the Plasmodium vivax circumsporozoite protein repeat region and a universal T helper epitope of tetanus toxin

Previous attempts in inducing protective immunity against Plasmodium vivax in human volunteers and nonhuman primates with recombinant circumsporozoite (CS) proteins have been unsuccessful, largely due to the failure of generating antibodies against the protective B epitope AGDR in the CS protein repeat region. We report here an immunization study in Saimiri monkeys with a multiple antigen construct (MAC) containing the P. vivax CS protein repeat region and a T helper epitope of tetanus toxin formulated in different adjuvants. Monkeys immunized three times with MAC in copolymer P1005, copolymer P1005 plus RaLPS, or MF-75 had titers of antibodies against CS repeat, sporozoites and the protective B epitope AGDR significantly higher than those immunized with MAC in alum or PBS (P < 0.05). Antibody levels in animals that received P1005 were maintained at high level for 7 months after the last immunization. Upon challenge with 10000 sporozoites 2 weeks after the last immunization, 75% (three of four) of monkeys from the alum group, 50% (three of six) of monkeys from the P1005 plus RaLPS group, 40% (two of five) of monkeys from the P1005 group, 33% (two of six) of monkeys from the MF-75 group, and 17% (one of six) of monkeys from the MAC alone group were fully protected. When immunized animals were challenged again with 30000 sporozoites 22 weeks after the last immunization. 40% (two of five) monkeys from the P1005 group were fully protected. The remaining (three) in this group developed low parasitemia (< 2000 parasites mm-3 of blood) after significantly longer prepatent period (P < 0.05). In addition, 17% (one of six) of monkeys each from the P1005 plus RaLPS and MF-75 groups were also fully protected. Protected animals had higher levels of prechallenge anti-AGDR antibody titers than unprotected (1933 vs 281 for the first challenge, P > 0.05; 21527 vs 196 for the rechallenge, P < 0.05). Anti-AGDR antibody titers were positively correlated with the prepatent period of infected animals (r = 0.42 for the first challenge, P > 0.05; r = 0.60 for the rechallenge, P < 0.05) and negatively correlated with the peak parasitemia (r = -0.39 for the first challenge, P < 0.05; r = 0.50 for the rechallenge, P < 0.05). The results suggested that when combined with the use of potent adjuvants and T helper epitopes, MAC subunit vaccines may potentially offer protection against malaria infection.

Protective immunity induced in squirrel monkeys with a multiple antigen construct against the circumsporozoite protein of Plasmodium vivax

Saimiri boliviensis monkeys were immunized with a multiple antigen construct [(PvCS)2]2(P2)2 directed against the circumsporozoite protein of Plasmodium vivax or a combination of the multiple antigen construct with nonionic copolymer P1005, with P1005 and lipopolysaccharide, with muramyl tripeptide Mf-75, or with alum. Following intravenous challenge with 10,000 sporozoites of the Salvador I strain of P. vivax, 11 of the 26 monkeys were protected against patent parasitemia. Ten additional animals were partially protected. Following rechallenge of the 26 monkeys with 30,000 sporozoites of the homologous strain of parasite, four monkeys were totally protected and nine animals were partially protected.

Diameter-Selective Raman Scattering from Vibrational Modes in Carbon Nanotubes

Single wall carbon nanotubes (SWNTs) that are found as close-packed arrays in crystalline ropes have been studied by using Raman scattering techniques with laser excitation wavelengths in the range from 514.5 to 1320 nanometers. Numerous Raman peaks were observed and identified with vibrational modes of armchair symmetry (n, n) SWNTs. The Raman spectra are in good agreement with lattice dynamics calculations based on C-C force constants used to fit the two-dimensional, experimental phonon dispersion of a single graphene sheet. Calculated intensities from a nonresonant, bond polarizability model optimized for sp2 carbon are also in qualitative agreement with the Raman data, although a resonant Raman scattering process is also taking place. This resonance results from the one-dimensional quantum confinement of the electrons in the nanotube.

The relationship of fluorosis and brick tea drinking in Chinese Tibetans

Brick tea-drinking fluorosis is an unusual environmental problem. As a result of an investigation of tea-drinking habits, total fluoride intakes, dental fluorosis, and skeletal fluorosis, this disease has been found in the Sichuan Province of China in Tibetans with a long history of drinking brick tea. The dental fluorosis investigation of 375 Tibetan children (213 males, 162 females) and 161 Han children (86 males, 75 females), 8-15 years of age, was carried out in Daofu County, Sichuan Province. According to the standard of the Chinese Health Ministry, a skeletal fluorosis survey of 658 Tibetans (264 males, 394 females) and 41 Hans (20 males, 11 females), all over 16 years old, was performed. The total fluoride intake and fluorosis were determined from a question--calculation method in all participants. The morbidities of dental fluorosis in Tibetan and Han children are 51.2% and 11.05%, respectively, and the indexes of dental fluorosis are 1.33 and 0.17 (chi 2 = 75.7, p < 0.01) respectively. The morbidity of skeletal fluorosis is 32.83% for Tibetan children and zero for the Han children. The fluoride intakes of Tibetan children and adults were 5.49 mg/person/day and 10.43 mg/person/day, respectively, in this area. Of total everyday fluoride intake, 94.2% by children and 94.4% by adults was from brick tea and zanba (r = 0.99).

Surgical treatment of coronary artery fistulae associated with other cardiovascular anomalies

OBJECTIVE

To evaluate retrospectively our surgical experience, techniques and long-term results in 11 patients with coronary artery fistulae associated with other cardiovascular anomalies.

METHODS

From January 1980 to April 1995, 11 patients with coronary artery fistulae associated with other cardiovascular anomalies were found among 20,000 open-heart procedures and treated surgically. Besides closure of the fistulae, coronary artery bypass grafting was performed in 5 patients with atherosclerotic coronary artery disease, and aneurysm angioplasty was done in 4 patients with coronary artery aneurysm. Ventricular septal defect and patent ductus arteriosus were closed in one patient and mitral valve replacement was performed in another patient.

RESULTS

There were no surgical deaths, but one late death due to acute myocardial infarction occurred 6 months after surgery. The mean follow-up time was 75.7 months and all patients' functional status improved by an average 1.4 judged by the New York Heart Association functional classification.

CONCLUSIONS

Coronary artery fistula associated with other cardiovascular anomalies will aggravate symptoms and cause deterioration of heart function. Therefore, evaluation and surgical intervention should be done as soon as possible to restore coronary blood flow and correct concomitant cardiovascular anomalies. The surgical results are excellent with a low operative risk and good long-term results.

[Detection of stromelysin mRNA expression in human hepatocellular carcinoma by in situ hybridization]

For the propose of detecting the significance of stromelysin (of matrix metalloproteinase family) mRNA expression in the invasion and metastasis process of liver cell carcinoma, 19 cases of human hepatocellular carcinoma (HCC) and their surrounding tissues were studied by in situ hybridization techniques. Nine cases of the HCC tissues were positive while all the tumor surrounding tissues were negative. The stromelysin expression levels were higher in those HCC complicated with portal tumor emboli or in those classified pathologically in II-IV degree. It is considered that portal cancer emboli is a characteristic event for intrahepatic and extrahepatic metastasis of HCC, and matrix metalloproteinase may be of importance for the tumor invasion and metastasis.

Effect of 24 hours of starvation on plasma glucose and insulin concentrations in subjects with untreated non-insulin-dependent diabetes mellitus

Adherence to a low-calorie diet often results in a decrease in blood glucose concentration in persons with non-insulin-dependent diabetes mellitus (NIDDM). Whether this is due to the resultant weight loss or to a decrease in caloric intake has been uncertain. We have obtained data previously that indicated a very short-term reduction in caloric intake (5 hours) resulted in a significant decrease in plasma glucose concentration in subjects with NIDDM. The purpose of the present study was to determine if a further decrease in glucose would occur if the fast was extended from 5 to 24 hours. Seven male subjects with untreated NIDDM were studied after an 11-hour overnight fast. For the subsequent 24-hour period, subjects were given only water. Blood was obtained for glucose, insulin, C-peptide, triglycerides, nonesterified fatty acids (NEFA) alpha-amino acid nitrogen, urea nitrogen, and glucagon at hourly intervals for 24 hours beginning at 8 AM. The amount of glycogen degraded was calculated based on the potassium balance. Plasma glucose decreased from 158 mg/dL at 8 AM to a nadir of 104 mg/dL at 7 PM. It then increased by 30 mg/dL. Corresponding changes occurred in insulin and C-peptide. Serum glucagon remained unchanged. Serum alpha-amino acid nitrogen and urea nitrogen decreased. Triglycerides and NEFA increased. The calculated glycogen utilized over this period was approximately 167 g. This would provide approximately 700 kcal energy. The elevated blood glucose concentration in mild to moderately severe untreated NIDDM subjects was normalized following short-term fasting. Plasma insulin concentrations also decreased to within normal limits. These decreases were highly significant. Glycogenolysis is an important source of fuel during this period.

Antioxidant enzymes in intramural nerves of the opossum esophagus

Superoxide radical (O2-.) combines with nitric oxide (NO) to form peroxynitrite, thereby nullifying the biological activity of NO. Superoxide dismutase (SOD) prevents this reaction by converting O2-. to H2O2. We tested the hypotheses that the antioxidant enzymes catalase (CAT), Mn SOD, and Cu/Zn SOD are present in enteric neurons of the opossum esophagus, and that O2-. alters esophageal motor function. Immunostaining demonstrated CAT, Mn SOD, and Cu/Zn SOD immunoreactivity in interganglionic nerve bundles and ganglia of the myenteric and submucosal plexuses. Western blot analysis confirmed the presence of these enzymes in homogenates of esophageal muscularis propria, and enzyme assays demonstrated Cu/Zn SOD and Mn SOD activities of 262 and 73 U/mg protein, respectively. Both diethyldithiocarbamic acid, an inhibitor of Cu/Zn SOD, and xanthine (X) with xanthine oxidase (XO), which generate O2-., shortened the latency of the nerve-mediated contraction of circular esophageal muscle, the off response, by 20.2 and 23.4%, respectively. SOD alone did not affect the latency, but it inhibited the effect of X with XO on the latency. Antioxidant enzymes found in intramural esophageal nerves may play a role in regulating NO-mediated neuromuscular communication in the esophagus.

Manganese superoxide dismutase and reduced nicotinamide adenine dinucleotide diaphorase colocalize in the rat gut

BACKGROUND & AIMS

Superoxide and other free radicals participate in inflammatory bowel disease and ischemia-reperfusion injury. Manganese superoxide dismutase (SOD) scavenges superoxide. Mn SOD is colocalized with reduced nicotinamide adenine dinucleotide (NADH) diaphorase in some tissues. NADH diaphorase histochemistry selectively stains enteric nerves. The aim of this study was to seek colocalization of Mn SOD with NADH diaphorase in the gut, especially in enteric nerves.

METHODS

Indirect immunofluorescent staining and histochemistry were used to localize Mn SOD and NADH diaphorase in rat gut.

RESULTS

Strong Mn SOD immunoreactivity was found in parietal cells, most intramural nerve cell bodies, the colonic interstitial cells of Cajal (at the submucosa-circular muscle layer interface), and intestinal epithelium cells. Weak to moderate Mn SOD immunoreactivity characterized smooth muscle cells, small submucosal arteries, esophageal striated muscle, esophageal epithelium, gastric epithelium, and intestinal glands. NADH diaphorase histochemistry (with Triton X-100) resulted in identical staining.

CONCLUSIONS

Mn SOD and NADH diaphorase are colocalized throughout rat gut with strong activity in enteric nerves and colonic interstitial cells of Cajal.

Co-localization of manganese superoxide dismutase and NADH diaphorase

Manganese superoxide dismutase (Mn SOD), mitochondrial enzyme, defends against the toxic effects of superoxide radical (O2.-) in pathological processes by catalyzing the conversion of O2.- to hydrogen peroxide (H2O2). The activity of another enzyme, NADH diaphorase, forms the basis for a histochemical method used commonly to demonstrate nerve cell bodies in the enteric plexuses. We found identical patterns of localization of Mn SOD immunoreactivity and NADH diaphorase activity in brain, esophagus, stomach, colon, liver, and kidney. NADH diaphorase enzymatic activity co-migrated with complexes of Mn SOD on a non-denaturing gel. This suggests that the NADH diaphorase may in some way be related to Mn SOD.