Optimum ratio of histidine in the piglet ideal protein model and its effects on body metabolism. I. Basal diet formulation based on digestible amino acids according to the ideal protein model for 10 to 20 kg piglets

A 4 x 4 Latin square design was used to determine ileal apparent digestibility of amino acids (AAs) in corn, soybean meal, feather meal and dried whey in young pigs. The data were then to be used in formulating a basal diet for studies on AA metabolism in young pigs. Eight castrates T-cannulated at terminal ileum (average initial body weight 12.5 +/- 0.62 kg) were divided into 4 groups on the basis of body weight and transferred to individual metabolism crates. They were then fed four experimental diets containing the four feedstuffs to be tested (corn, soybean meal, feather meal and dried whey). The trial lasted 20 days, which included 4 five-day periods for ileal digesta collection. It was found that the digestibility of the AAs was similar to that reported in literature. Based on the findings a basal diet for this research was formulated according to an ideal protein model for the 10 to 20 kg piglet, on the basis of digestible AAs and containing 14.13 MJ/kg digestible energy, 18.22% crude protein, 1.04% digestible lysine and 0.23% digestible histidine.

Extracting hidden information from knowledge networks

We develop a method allowing us to reconstruct individual tastes of customers from a sparsely connected network of their opinions on products, services, or each other. Two distinct phase transitions occur as the density of edges in this network is increased: Above the first, macroscopic prediction of tastes becomes possible; while above the second, all unknown opinions can be uniquely reconstructed. We illustrate our ideas using a simple Gaussian model, which we study using both field-theoretical methods and numerical simulations. We point out a potential relevance of our approach to the field of bioinformatics.

Adeno-associated virus vector-mediated IL-10 gene delivery prevents type 1 diabetes in NOD mice

The development of spontaneous autoimmune diabetes in nonobese diabetic (NOD) mice provides for their use as a model of human type 1 diabetes. To test the feasibility of muscle-directed gene therapy to prevent type 1 diabetes, we developed recombinant adeno-associated virus (rAAV) vectors containing murine cDNAs for immunomodulatory cytokines IL-4 or IL-10. Skeletal muscle transduction of female NOD mice with IL-10, but not IL-4, completely abrogated diabetes. rAAV-IL-10 transduction attenuated the production of insulin autoantibodies, quantitatively reduced pancreatic insulitis, maintained islet insulin content, and altered splenocyte cytokine responses to mitogenic stimulation. The beneficial effects were host specific, as adoptive transfer of splenocytes from rAAV IL-10-treated animals rapidly imparted diabetes in naive hosts, and the cells contained no protective immunomodulatory capacity, as defined through adoptive cotransfer analyses. These results indicate the utility for rAAV, a vector with advantages for therapeutic gene delivery, to transfer immunoregulatory cytokines capable of preventing type 1 diabetes. In addition, these studies provide foundational support for the concept of using immunoregulatory agents delivered by rAAV to modulate a variety of disorders associated with deleterious immune responses, including allergic reactions, transplantation rejection, immunodeficiencies, and autoimmune disorders.

[PLA2 activity in serum and cutaneous tissues in patients with psoriasis vulgaris]

We examined the activity of PLA2 by quick simple trace titration method in the serum and cutaneous tissues in patients with psoriasis vulgaris patients than that in the control group. The activity of PLA2 was significantly higher in psoriasis vulgaris patients than that in the control group. PLA2 activity in sera of psoriasis patients in the active stage or rash area > 30% was higher than that in the inactive stage or rash area < 30%. It is suggested that the sera PLA2 activity may be related to the disease activity in patients with psoriasis vulgaris, and PLA2 may play an important role in the pathogenesis of the psoriasis.

[Compound EPSPs and action potential of mauthner cell evoked by skin stimulation in crucian carp]

OBJECTIVE

To investigate the effects of afferent excitatory inputs from skin on the excitability of Mauthner cell (M cell) of crucian carp.

METHODS

Multiple-site intracellular recordings on the soma and the ventral dendrite (VD) of M cell and direct current stimulation on the skin surface of the fish's trunk were employed.

RESULTS

Direct stimulation of the skin evoked 3 groups of compound excitatory postsynaptic potentials (EPSPs) on soma and VD of M cell. Group a EPSP had the lowest amplitude (< or = 0.35 mV), which was insensitive to high-frequency stimulation. It had the shortest latency (mean 1.9 ms) and could be recorded on the soma and the proximal end of VD. Group b EPSP had the highest amplitude (< or = 9.7 mV), which was increased when the recording electrode was moved from the soma to the distal end of VD. The latency of Group b (mean 4.5 ms) was shorter than that of Group c, but longer than that of Group a. We firstly found that action potential could be induced on the basis of Group b in M cell by skin stimulation. Group c EPSP was our new finding, which could only be evoked by higher intensity (noxious) stimulus (> or = 100 V). It had the longest latency (mean 13.5 ms) with amplitude between those of a and b, and was very sensitive to high frequency stimulation. All the three groups of EPSPs were superimposed with spike-like transient potentials, which were believed to be the sign of electrical synapse activities.

CONCLUSIONS

(1) Action potential can be induced on M cell by skin stimulation, which is in controversy with previous reports; (2) the noxious skin stimulation can induce a late EPSP (Group c) in M cell; (3) the neural pathway projecting from skin to M cell is composed of a set of neuronal chains with different number of synaptic relays, in which short chains projected concentrically to the soma and the proximal part of VD, while long chains projected mainly to the distal part of VD; (4) both electrical and chemical synapses may exist in short and long pathways.

[Immune functional changes in patients of acute Henoch-Schonlein purpura and regulatory effect of integrated Traditional Chinese and Western medicine on it]

OBJECTIVE

To observe the changes of immune function in children with acute Henoch-Schonlein purpura (AHSP) and the effects of integrated traditional Chinese and western medicine (TCM-WM) on it.

METHODS

Immunological criteria in TCM-WM group (n = 35) treated by Yinfu Decoction (YFD) combined with transfer factor and 35 patients in the control group (n = 35) treated by conventional treatment were observed and compared before and after treatment. Also the criteria were compared with those of 40 healthy subjects.

RESULTS

Before treatment, the levels of IgA, IgM, CD4, CD4/CD8 ratio, rosette forming rate of RBC-C3b receptor in patients were higher than those in the healthy subjects, but the levels of CD8 was obviously lower, the difference was significant (P < 0.01). The above-mentioned criteria were all improved in the two treated groups after treatment, and the improvement was more significant in the TCM-WM group than that in the control group (P < 0.05). Besides, the cure-markedly effective rate in the former was better than that in the latter significantly (P < 0.01).

CONCLUSION

There exist multiple immune functional disturbance in AHSP patients. Combined treatment of YFD and transfer factor has obvious immune regulatory effect and is an effective therapy with few side-effects and low recurrence rate.

[Effects of fluid percussion injury on intracellular [Ca2+]i and pH in cultured rat neurons]

AIM

To study the change of intracellular [Ca2+]i and pH in cultured neurons after fluid percussion injury, and the therapeutic effect of drugs.

METHODS

The neurons of Sprague Dawley rats were cultured for 8-14 days, then treated them with fluid percussion injury (2.5 kPa, 20 ms). Alterations of [Ca2+]i and pH in single neural cells following fluid percussion injury were measured by a laser scanning confocal microscope. After being injured for several hours the cultured neurons were treated with nimodipine or D-(-)-2-amino-5-phosphonovaleric acid (D-AP-5). Two hours later, the effects of drugs on intracellular [Ca2+]i and pH were studied.

RESULTS

The Intracellular [Ca2+]i increased quickly after brain injury and reached peak in 12 hours. It then decreased gradually and became normal at 48 hours. The pH decreased slowly, reached minimum in 12 hours, and then kept at a lower level. It did not recover normal at 48 hours. Nimodipine and D-AP-5 decreased significantly the ascension of [Ca2+]i and the descent of pH. But nimodipine and D-AP-5 must be given within 10 hours after injury for a good therapeutic effect.

CONCLUSION

According to the change of intracellular [Ca2+]i and pH, early use of nimodipine and D-AP-5, will get a better therapeutic effect.

[Study on the specificity of complement C5 for the postmortem diagnosis of myocardial infarction]

In order to explore the specificity of complement C5 in the postmortem diagnosis of myocardial infarction, changes of C5 staining in normal, infarcted and other non-infarcted myocardia with direct or indirect myocardial injuries (myocarditis, mechanical asphyxia, electrocution, hemorrhagic shock, cardiac contusion and organophosphate poisoning) were studied with immunohistochemistry and image analysis. The results showed that positive C5 staining could be observed in groups of myocardial infarction and myocarditis, but not in groups of mechanical asphyxia, electrocution, hemorrhagic shock, cardiac contusion, and organophosphate poisoning. It is indicated that positive reaction of C5 could only be affected by myocarditis, which means that it was more specific for the diagnosis of myocardial infarction.

Relationship between phenotypes of cell-function differentiation and pathobiological behavior of gastric carcinomas

AIM

To reveal the correlation between the functional differentiation phenotypes of gastric carcinoma cells and the invasion and metastasis by a new way of cell-function classification.

METHODS

Surgically resected specimens of 361 gastric carcinomas(GC) were investigated with enzyme-, mucin-, and tumor-related marker immunohistochemistry. According to the direction of cell-function differentiation, stomach carcinomas were divided into five functionally differentiated types.

RESULTS

(1) Absorptive function differentiation type (AFDT): there were 82 (22.7%) patients including 76 (92.7%) aged 45 years. Sixty-nine (84.1%) cases belonged to the intestinal type. Thirty-eight (46.3%) expressed CD44v6 and 9 (13.6%) of 66 male patients developed liver metastasis. The 5-year survival rate of patients in this group (58.5%) was higher than those with the other types (P<0.01). (2) Mucin secreting function differentiation type (MSFDT): 54 (15%) cases. Fifty-three (98.1%) tumors had penetrated the serosa, 12 (22.2%) expressed ER and 22 (40.7%) expressed CD44v6. The postoperative 5-year survival rate was 28.6%. (3) Absorptive and mucin-producing function differentiation type (AMPFDT): there were 180 (49.9%) cases, including 31 (17.2%) aged younger than 45 years. The tumor was more common in women (62, 34.4%,) and expressed more frequently estrogen receptors (ER) (129, 81.7%) than other types (P<0.01). Ovary metastasis was found in 12 (19.4%) out of 62 female subjects. The patients with this type GC had the lowest 5-year survival rate (24.7%) among all types. (4) Specific function differentiation type (SFDT): 13 (3.6%) cases. Nine (69.2%) tumors of this type derived from APUD system, the other 4 (30.7%) were of different histological differentiation. Sixty per cent of the patients survived at least five years. (5) Non-function differentiation type (NFDT): 32 (8.9%) cases. Nineteen (59.4%) cases had lymph node metastases but no one with liver or ovary metastasis. The 5-year survival rate was 28.1%.

CONCLUSION

This new cell-function classification of GC is helpful in indicating the characteristics of invasion and metastasis of GC with different cell-function differentiation phenotypes. Further study is needed to disclose the correlation between the cell-functional differentiation phenotypes and the relevant genotypes and the biological behavior of gastric carcinoma.

Ultrastructure of the postcorpus of the esophagus of Teratocephalus lirellus (Teratocephalida) and its use for interpreting character evolution in Secernentea (Nematoda)

The ultrastructure of the postcorpus of the putative outgroup of Secernentea (Nematoda), Teratocephalus lirellus (Teratocephalida), is compared with previous observations of representative species Zeldia punctata (Cephalobina), Caenorhabditis elegans (Rhabditina), and Diplenteron sp. (Diplogastrina) in order to interpret the evolution of feeding structures within Secernentea. The postcorpus of T. lirellus consists of 6 marginal, 13 muscle, 3 gland, and 11 nerve cells. In both T. lirellus and Z. punctata, one duct from each of two subventral glands opens into the esophageal lumen at the junction of the isthmus and the basal bulb, whereas in C. elegans and Diplenteron sp., homologous openings are at the posterior end of the median bulb. Caenorhabditis elegans and Z. punctata each have two additional glands that open within the basal bulb. The postcorpus of each taxon has four anterior-to-posterior layered sets of radial muscle cells, except in Diplenteron sp., which lacks a grinder and has homologs to the anterior two sets only. The anterior set of muscles of T. lirellus and Z. punctata includes six mononucleate cells, whereas the homolog in C. elegans and Diplenteron sp. includes three binucleate cells. Evaluation of character polarity defines Rhabditina and Diplogastrina as sister taxa, and suggests that the character of five glands may result from functional convergence.

Discretized diffusion processes

We study the properties of the "rigid Laplacian" operator; that is we consider solutions of the Laplacian equation in the presence of fixed truncation errors. The dynamics of convergence to the correct analytical solution displays the presence of a metastable set of numerical solutions, whose presence can be related to granularity. We provide some scaling analysis in order to determine the value of the exponents characterizing the process. We believe that this prototype model is also suitable to provide an explanation of the widespread presence of power law in a social and economic system where information and decision diffuse, with errors and delay from agent to agent.

Adaptive response of thymocyte apoptosis and cell cycle progression induced by low dose X-ray irradiation in mice

The dose-effect of adaptive response of thymocyte apoptosis and cell cycle progression induced by whole-body X-ray irradiation (WBI) was studied in male Kunming mice. The inductive doses (D1) were 25, 50, 75, 100 or 200 mGy 6 h before the challenging doses (D2) of 1.0, 1.5 or 2.0 Gy. The changes in the percentages of the thymocyte apoptotic bodies (TAB) and the cells in different phases of cell cycle were measured with flow cytometry. The percentages of TAB decreased, the arrests of G1 and G2 + M phases diminished, and the cells of DNA synthesis of S phase increased when the D1 + D2 groups was compared with the D2 groups. When D1 was 200 mGy, the adaptive response of thymocyte apoptosis and cell cycle progression were no longer induced by low dose radiation (LDR). In addition, the extracellular fluid from the splenocytes were cultured with Con A for 48 h in vitro 24 h after 75 mGy WBI was placed in the murine thymocyte suspension from mice irradiated with 2.0 Gy WBI and co-incubated. The thymocyte apoptosis decreased. Especially, noteworthy was that the percentages of TAB after the incubation for 72 h were significantly lower than those in 2.0 Gy irradiated thymocytes (P < 0.05). These results indicate that when the mice were irradiated with 25-100 mGy (D1, 12.5 mGy/min) 6 h before 1.0-2.0 Gy (D2, 0.287 Gy/min) exposure, an adaptive response of thymocyte apoptosis and cell cycle progression may be induced under the condition of WBI, and LDR (75 mGy) may change the microenvironment of immune cells and decrease the thymocyte apoptosis.

Protection against myocardial dysfunction induced by global ischemia-reperfusion by antisense-oligodeoxynucleotides directed at beta(1)-adrenoceptor mRNA

Plasma catecholamine levels rise, and myocardial beta(1)-adrenoceptor (beta(1)-AR) sensitivity increases during ischemia. These factors enhance myocardial injury and cardiac dysfunction. beta(1)-AR blockers are clinically used to protect heart against ischemia and to improve cardiac dysfunction in patients with ischemic heart disease, but these agents often cause intolerable side effects. To examine the potential cardioprotective effect of therapy with antisense-oligodeoxynucleotides directed at beta(1)-AR mRNA (beta(1)-AS-ODNs) during myocardial ischemia-reperfusion, Sprague-Dawley rats were treated with beta(1)-AS-ODNs or inverted-oligodeoxynucleotides (IN-ODNs), each 200 microg/rat. Hearts were excised, perfused, and subjected to global ischemia (30 min) followed by reperfusion (30 min). Other rats were given selective beta(1)-AR blocker atenolol (2 mg/kg) or saline before excising the hearts. Ischemia-reperfusion resulted in cardiac dysfunction, indicated by an increase in coronary perfusion pressure and left ventricular end-diastolic pressure and a decrease in developed left ventricular pressure, as well as evidence of lipid peroxidation in saline-treated rats (all P <.05 versus control values). Administration of AS-ODNs or atenolol, but not IN-ODNs, protected hearts against functional deterioration and lipid peroxidation (P <.05 versus saline or IN-ODNs treatment). AS-ODNs therapy appeared to be equivalent to atenolol in these effects. Expression of beta(1)-AR protein as well as mRNA in the myocardium were markedly up-regulated after ischemia-reperfusion, and treatment with beta(1)-AS-ODNs, but not atenolol, decreased the rise in enhanced expression of beta(1)-AR. These observations imply that beta(1)-AS-ODNs can ameliorate cardiac dysfunction after ischemia-reperfusion by reducing the expression of beta(1)-AR in the ischemic-reperfused myocardium.

Ultrastructure of the post-corpus of Zeldia punctata (Cephalobina) for analysis of the evolutionary framework of nematodes related to Caenorhabditis elegans (Rhabditina)

The ultrastructure of the post-corpus of Zeldia punctata (Cephalobina) was compared with previous observations of Caenorhabditis elegans (Rhabditina) and Diplenteron sp. (Diplogastrina) with the goal of interpreting the morphological evolution of the feeding structures in the Secernentea. The post-corpus of Z. punctata consists of six marginal, 13 muscle, five gland and seven nerve cells. The most anterior of four layers of muscle cells consists of six mononucleate cells in Z. punctata. The homologous layer in C. elegans and Diplenteron consists of three binucleate cells, suggesting a unique derived character (synapomorphy) shared between the Rhabditina and Diplogastrina. Contrary to Diplenteron sp. where we observed three oesophageal glands, Z. punctata and C. elegans have five oesophageal glands. We question this shared character as reflecting a common evolution between the Cephalobina and Rhabditina, because there are strong arguments for functional (adaptive) convergence of the five glands in these bacterial feeders. Convergence is further suggested by the mosaic distribution of three versus five glands throughout the Nemata; this distribution creates difficulties in establishing character polarity. Although morphological data are often laborious to recover and interpret, we nevertheless view 'reciprocal illumination' between molecular and morphological characters as the most promising and robust process for reconstructing the evolution of the Secernentea and its feeding structures.

Antisense inhibition of beta(1)-adrenergic receptor mRNA in a single dose produces a profound and prolonged reduction in high blood pressure in spontaneously hypertensive rats

BACKGROUND

beta-Blockers are the first line of therapy for hypertension. However, they are associated with side effects because of central nervous system (CNS) effects and beta(2)-adrenergic antagonism. To overcome these problems and provide a long-term beta(1)-blockade, antisense oligonucleotides against rat beta(1)-adrenergic receptor (beta(1)-AR) mRNA (beta(1)-AS-ODN) were designed and tested for the ability to inhibit cardiac beta(1)-ARs as well as lower blood pressure in spontaneously hypertensive rats (SHRs).

METHODS AND RESULTS

Radioligand binding assay showed that a single intravenous injection of beta(1)-AS-ODN delivered in cationic liposomes significantly decreased cardiac beta(1)-AR density by 30% to 50% for 18 days (P<0.01), with no effect on beta(2)-ARs. This was accompanied by marked attenuation of beta(1)-AR-mediated positive inotropic response in isolated perfused hearts in vitro (P<0.02) and in conscious SHRs monitored by telemetry in vivo (P<0.02). Furthermore, the blood pressure of SHRs was reduced for 20 days, with a 38 mm Hg maximum drop. Heart rate was not significantly decreased. Quantitative autoradiography was performed to assess beta(1)-AS-ODN effects on the CNS, which demonstrated no changes in beta(1)-ARs in brain, in contrast to a significant reduction in heart and kidney (P<0.05). For comparison with beta-blockers, the effects of atenolol on cardiovascular hemodynamics were examined, which lowered blood pressure for only 10 hours and elicited appreciable bradycardia in SHRs.

CONCLUSIONS

These results indicate that beta(1)-AS-ODN, a novel approach to specific beta(1)-blockade, has advantages over currently used beta-blockers in providing a profound and prolonged reduction in blood pressure without affecting heart rate, beta(2)-ARs, and the CNS. Diminished cardiac contractility resulting from less beta(1)-AR expression contributes to the antihypertensive effect.

Intravenous angiotensinogen antisense in AAV-based vector decreases hypertension

Angiotensinogen (AGT) has been linked to hypertension. Because there are no direct inhibitors of AGT, we have developed antisense (AS) inhibition of AGT mRNA delivered in an adeno-associated virus (AAV)-based plasmid vector. This plasmid, driven by the cytomegalovirus promoter, contains a green fluorescent protein reporter gene and AS cDNA for rat AGT. Transfection of the plasmid into rat hepatoma cells brought a strong expression of the transgenes and a significant reduction in the level of AGT. In the in vivo study, naked plasmid DNA was intravenously injected into adult spontaneously hypertensive rats at different doses (0.6, 1.5, and 3 mg/kg). Expression of AGT AS mRNA was present in liver and heart, and it lasted longer in the liver. All three doses produced a significant decrease in blood pressure (BP). BP decreased for 2, 4, and 6 days, respectively. The lowest dose decreased BP by 12 +/- 3.0 mmHg, whereas the higher doses decreased BP by up to 22.5 +/- 5.2 mmHg compared with the control rats injected with saline (P < 0.01). The injection of the plasmid with liposomes produced a more profound and longer reduction (8 days) in BP. Consistent changes in plasma AGT level were observed. Sense plasmid had no effect. No liver toxicity was observed after injection of AS plasmid with or without liposomes. Our results suggest that the systemic delivery of AS against AGT mRNA by AAV-based plasmid vector, especially with liposomes, may have potential for gene therapy of hypertension and that further studies with the plasmid packaged into a recombinant AAV vector for a longer-lasting AS effect are warranted.

Effectiveness of Glomus species in protecting white clover against nematode damage

Three species of arbuscular mycorrhizal (AM) fungi, Glomus aggregatum Schenck and Smith emend. Koske, Glomus intraradices Schenck and Smith, and Glomus mosseae (Nicol. and Gerd.) Gerdemann and Trappe, were evaluated for their effectiveness to suppress the plant parasitic nematode Meloidogyne incognita (Kofoid and White) Chitwood in white clover (Trifolium repens L.) in a greenhouse study. Forty 1-day-old seedlings not colonized or colonized to the same extent by the fungi were transplanted into a growth medium uninoculated or inoculated with 10 000 M. incognita eggs. After 40 days of further growth, root mass, shoot mass, extent of galling, number of nematodes and nematode eggs in roots, and extent of mycorrhizal colonization of roots were determined. Growth of white clover was significantly stimulated by mycorrhizal colonization, and nematodes caused the greatest damage when plants were not colonized by the fungi. The degree to which mycorrhizal fungi reduced nematode damage varied with the species of mycorrhizal fungus; the extent of damage reduction ranged from 19 to 49.8%, based on loss of shoot mass. The effectiveness of the mycorrhizal fungal species in suppressing nematodes was not related to the degree to which they colonized roots or their effectiveness in enhancing host growth.Key words: AM colonization, galls, Glomus aggregatum, Glomus intraradices, Glomus mosseae, inoculum potential, Meloidogyne incognita, nematode eggs, phosphorus.

Upregulation of endothelial receptor for oxidized low-density lipoprotein (LOX-1) in cultured human coronary artery endothelial cells by angiotensin II type 1 receptor activation

Cross talk between oxidized LDL (ox-LDL) and angiotensin II (Ang II) may be relevant in atherosclerosis. In this study, we examined the presence of a specific endothelial receptor for ox-LDL (LOX-1) and Ang II receptors in human coronary artery endothelial cells (HCAECs). In addition, we studied the effect of Ang II on LOX-1 gene and protein expression. LOX-1 was consistently identified in HCAECs by reverse transcriptase-polymerase chain reaction (RT-PCR), cDNA sequence, Western blot, and 125I-labeled ox-LDL binding assay (Bmax, 29.7 ng/mg protein). The HCAECs also exhibited Ang II receptors (AT1>AT2), as determined by RT-PCR and 125I-labeled Ang II binding assay (Bmax, 2.21 and 1.19 fmol/mg protein, respectively). Incubation of HCAECs with Ang II markedly increased LOX-1 mRNA (RT-PCR) and protein (Western blot) expression. The increase in LOX-1 expression was dependent on Ang II concentration (10(-12) to 10(-6) mol/L). Ang II caused a concentration-dependent increase in 125I-labeled ox-LDL uptake by HCAECs and enhanced ox-LDL-mediated cell injury, as evident from an increase in LDH release and a decrease in cell viability. These effects of Ang II were completely blocked by pretreatment of HCAECs with losartan, a specific AT1 blocker, but not by PD123319, a specific AT2 blocker. These observations indicate the following: (1) HCAECs possess abundant LOX-1 as well as Ang II (AT1>AT2) receptors, (2) Ang II upregulates LOX-1 receptor and ox-LDL uptake, (3) the effects of Ang II are mediated by AT1 activation, and (4) Ang II enhances ox-LDL-mediated injury to HCAECs.

Ultrastructure of the Esophagus of Diplenteron sp. (Diplogasterida) to Test Hypotheses of Homology with Rhabditida and Tylenchida

The ultrastructure of the isthmus and basal bulb (postcorpus) of Diplenteron sp. (Diplogasterida) was revealed through transmission electron micrographs of serial sections. The postcorpus is glandular and muscular. There are 26 cells in the postcorpus, including 6 marginal (two sets of three), 6 muscle (two sets of three), 3 gland, and 11 nerve cells. Most of the cell bodies, including the nuclei, are in the basal bulb. Unlike Caenorhabditis elegans, Diplenteron sp. has three gland cells. The glands are embedded in a muscular framework in both taxa, but each gland cell is much bigger in Diplenteron sp. than in C. elegans. Each of the anterior set of three marginal cells is located at the apex of the esophageal lumen and overlaps slightly with one of the posterior sets of three marginal cells. All six marginal cells in Diplenteron sp. have homologs in C. elegans. The anterior set of radial muscle cells is V-shaped and is homologous to m5 muscle cells in C. elegans. The posterior set of muscle cells appears to be homologous to m6 muscle cells in C. elegans. Diplenteron sp. does not have muscle cells corresponding to the m7 cells associated with the "grinder" in C. elegans, which is absent in diplogasterids. The single saucer-shaped muscle cell, m8, covering the posterior wall of the basal bulb in C. elegans was not observed in Diplenteron sp. The structure of the esophageal-intestinal junction in Diplenteron sp. is similar to that of C. elegans in being composed of five epithelial cells. Neurons appear to be more abundant in Diplenteron sp. than in C. elegans. Ultrastructure of the esophagus in diplogasterids, rhabditids, cephalobids, and tylenchids will be useful in testing classical and recent competing hypotheses of secernentean phylogeny.

Critical role of AT1 receptor expression after ischemia/reperfusion in isolated rat hearts: beneficial effect of antisense oligodeoxynucleotides directed at AT1 receptor mRNA

To examine the relevance of angiotensin II type 1 receptor (AT1R) expression in the determination of myocardial function after ischemia/reperfusion, Sprague-Dawley rats were treated intravenously with antisense oligodeoxynucleotides (AS-ODNs) directed at AT1R mRNA (100 microg/rat, n=9) or scrambled antisense oligodeoxynucleotides (Scr-ODNs, 100 microg/rat, n=6). Both AS-ODNs and Scr-ODNs were given along with 300 microg/rat of liposome DOTAP/DOPE, a positive electron carrier (wt:wt= 1:1). The hearts from AS-ODN- or Scr-ODN-treated rats were excised 24 hours later, perfused in vitro, and subjected to 25 minutes of global ischemia followed by 30 minutes of reperfusion. Parallel groups of rats were given the specific AT1R antagonist losartan (10 mg/kg IV, n=6) or saline (n=7) 4 to 6 hours before excising the hearts. Ischemia/reperfusion resulted in a significant increase in myocardial AT1R expression (autoradiography and binding assay) and myocardial dysfunction, indicated by increases in coronary perfusion pressure and left ventricular end-diastolic pressure and a decrease in developed left ventricular pressure (all P<0.01 versus baseline) in the saline-treated group. AT1R protein and mRNA levels also increased in ischemic/ reperfused myocardial tissues. Administration of AS-ODNs or losartan, but not Scr-ODNs, preserved myocardial function and blocked the increased AT1R binding after ischemia/reperfusion (both P<0.01). Myocardial AT1R mRNA levels were not affected by either AS-ODNs or losartan, and the AT1R protein levels were significantly reduced by AS-ODN, but not losartan, treatment. Plasma angiotensin II levels increased after administration of losartan but not after administration of AS-ODNs. These observations imply a critical role of AT1R upregulation in determining myocardial function immediately after ischemia/reperfusion. AS-ODNs to AT1R mRNA may be more beneficial than losartan, because losartan does not affect the plasma angiotensin II level. The sustained increase in AT1R mRNA, but diminished protein expression, in rat hearts treated with AS-ODNs suggests that AS-ODNs block AT1R at the translational level.

Artemisinin blocks activating and slowly activating K+ current in guinea pig ventricular myocytes

AIM

To study the effect of artemisinin (Art) on outward rectifier potassium current in ventricular myocytes.

METHODS

In isolated guinea pig ventricular myocytes, the effects of Art on the two components of delayed outward rectifier K+ current (IK), the rapidly activating inward K+ current (IKr), and the slowly rectifying outward K+ current (IKs) were observed by the whole cell patch-clamp technique.

RESULTS

Art decreased IK in a concentration-dependent manner. The IKstep and IKtail were reduced from 387 +/- 46 pA to 240 +/- 48 pA and from 299 +/- 30 pA to 130 +/- 38 pA, respectively at holding potential of +40 mV by Art 50 mumol.L-1. The envelope of tail analysis suggested that both IKr and IKs were inhibited.

CONCLUSION

Art blocked the two components of delayed outward rectifier K+ current (IKr and IKs) in guinea pig ventricular cells.

Comparative study on 4 EIA kits for screening antibody to hepatitis C virus in pooled sera

Four enzyme immunoassay (EIA) test kits, 1 Canadian product and 3 Chinese products, were used in the comparative study. Each pool consisted of 5 sera, and the 5 single sera were tested as controls. The tests were carried out according to the instructions, keeping the same dilution of each serum in single and pool samples. It was found that with the Canadian kit, the positive and negative results of pooled sera had no difference from that of the controls (P > 0.10). In the case of Chinese Yali and Kehua kits, the positive results of pooled sera showed no difference from the controls (P > 0.10), but the optical density (OD) of negative pools were increased (P < 0.01), though quite distant from the cut-off values. In the case of Changzheng kit, the OD of positive pools were significantly lower than those of the controls (P < 0.05), and weak positive samples missed the detection. However this problem could be overcome by blocking the microwells beforehand. Our experiment demonstrate that not all EIA test kits are suitable for screening pools for antibody to hepatitis C virus, and that it is important to assess the sensitivity of the EIA kit to be used for this purpose.

A prospective study of a serum-pooling strategy in screening blood donors for antibody to hepatitis C virus

BACKGROUND

To examine the feasibility and to perform a cost-benefit analysis of a pooling protocol of enzyme immunoassay (EIA) screening for antibody to hepatitis C virus (anti-HCV) under real conditions, a prospective study was carried out using sera from 1875 local blood donors.

STUDY DESIGN AND METHODS

In the absence of knowledge of the anti-HCV reactions, the donor's sera were pooled into groups of five consecutive samples for testing by EIA. The dilution and final volume of the serum pool were adjusted to equal those recommended for single-serum EIA by the manufacturer of the test kit. The results obtained were compared with those of single-serum EIA to assess the feasibility of the pooling protocol. By applying probability theory, the percentage of reduction in the number of tests performed (L value) when the serum-pooling strategy was used was calculated for several anti-HCV seroprevalences and for varied sizes of pool. The calculations were performed on a computer using a program compiled by the authors.

RESULTS

The results showed that seroprevalence was 2.24 percent (95% CI, 1.57-2.91%); the rate of false negativity was 0 (95% CI, 0-8.4%), the sensitivity of the pooling protocol was 100 percent (95% CI, 91.6-100.0%), the rate of false positivity was 0.8 percent (95% CI, 0-1.8%), and the specificity of the pooling protocol was 99.2 percent (95% CI, 98.2-100.0%). Cost-benefit analysis showed that the pooling protocol could save 69.3 percent of the cost. A table of L values can be used conveniently by serologists to determine the optimum pool size if estimates of seroprevalence are available.

CONCLUSION

The pool EIA did not perform worse than individual EIAs, and the pooling strategy was markedly less expansive. The pooling protocol was recommended for screening of anti-HCV-positive subjects from large populations with low seroprevalence.

Thymocyte apoptosis in response to low-dose radiation

Thymocyte apoptosis was assessed by counting apoptotic bodies with flow cytometry (FCM) and measuring DNA fragmentation with fluorescence spectrophotometry (FSP). J-shaped dose-response curves were obtained after both whole-body irradiation (WBI) of mice and in vitro irradiation of EL4 cells with doses ranging from 0.025 to 4 Gy X-rays. There was a significant reduction of apoptosis rate to below control level with doses within 0.2 Gy, and a dose-dependent increase in apoptosis with doses above 0.5 Gy. When thymocytes were cultured 24 h after WBI with 75 mGy X-rays in complete RPMI 1640 medium, a reduction in apoptosis was observed in the course of incubation for 72 h, and the presence of Con A in the medium accentuated this reduction in a dose- and time-dependent manner. The implications of these observations and the possible molecular mechanisms for future studies are proposed.

Evidence that disruption of connexon particle arrangements in gap junction plaques is associated with inhibition of gap junctional communication by a glycyrrhetinic acid derivative

Glycyrrhetinic acid exhibits many pharmacological activities, including the ability to block gap junctional communication. However, the mechanism of glycyrrhetinic action is not clear. Others have shown that glycyrrhetinic acid apparently binds to a single proteinatious binding site in the plasma membrane. We present evidence that while exposure to glycyrrhetinic acid derivatives may not affect protein synthesis or location, it does seem to alter connexon particle packing in gap junction plaques.

Effect of low dose radiation on intracellular calcium and protein kinase C in lymphocytes

It is first reported in the present paper that whole-body irradiation (WBI) with low dose X-rays could increase intracellular calcium ions ([Ca2+]i) and stimulate protein kinase C (PKC) activity of mouse lymphocytes. Following WBI of male Kunming mice with 75 mGy X-rays at a dose rate of 12.5 mGy/min the mobilization of [Ca2+]i with Con A in CD4+ and CD8+ Cells in the thymus and spleen was potentiated and the amplitude of [Ca2+]i mobilization in thymocytes in response to anti-CD3 monoclonal antibody increased with time from 4 to 24 h following low dose radiation. The PKC activity in the homogenate of spleen was markedly stimulated 12 h after WBI with 75 mGy, reaching its peak value at 24-48 h and coming down to lower than normal on day 7. However, the PKC activity in the separated T lymphocytes reached its peak value at 12 h and that in the B lymphocytes reached its peak value on day 4, both coming down to below control on day 7. The implications of this facilitation of signal transduction in T lymphocytes in the mechanism of immunoenhancement after low dose radiation were discussed.

Signal transduction in lymphocytes after low dose radiation

Mice were given whole-body irradiation (WBI) with 75 mGy X-rays which had previously been found to stimulate immunologic functions. This low dose radiation (LDR) potentiated [Ca2+]i mobilization in thymic and splenic lymphocytes in response to Con A and anti-CD3 McAb and activated protein kinase C in T and B lymphocytes of the spleen. The expression of TCR/CD3 molecules on the thymocytes was enhanced after LDR indicating an expedited maturation and differentiation process in the thymus. The changes in TCR/CD3 expression and [Ca2+]i mobilization in response to McAb-CD3 after LDR was found to be highly correlated. Meanwhile the transcription of c-fos and c-jun genes was up-regulated beginning 3 hours after LDR. The expression of IL2R in active thymocytes was potentiated 24 hours after LDR which coincided with the previous finding of increased secretion of IL2 by splenocytes after WBI with 75 mGy X-rays. It is first reported in the present paper that LDR could stimulate immunologic functions through facilitation of the signal transduction process in the lymphocytes.

Geographic pathology of gastric dysplasia in China

Six hundred seventeen cases of gastric dysplasia were studied morphologically and were grouped histogenetically into adenomatous, cryptal, regenerative, and globoid dysplasias. The characteristics and their relationships with various histological types of gastric carcinoma were analysed as well. Twenty-four cases of gastric dysplasia showed malignant change, which was most commonly seen in regenerative dysplasia in five high-incidence areas of gastric dysplasia in China. The causative factors of gastric dysplasia, especially regenerative dysplasia, were analysed in terms of foodstuffs and eating habits of the local inhabitants.

An epidemic of encephalitis and meningoencephalitis in children caused by echovirus type 30 in Shanghai

An outbreak of viral central nervous system infection occurred from May to September, 1991 in Shanghai, China. Totally 376 cases were admitted into our hospital, 54% with encephalitis and 46% with meningoencephalitis. Echovirus type 30 was isolated from CSF and stools of the patients. Only 3 of the patients were under 1 year of age. CSF examination revealed the cell count from 0-1600 x 10(6)/L. Interestingly, 9 had CSF PMNs over 90% and 13 had low sugar levels. EKG was randomly done in 20 patients and 15 demonstrated myocarditis. The outcome was uneventful in all except 1 who had psychological problem at the time of discharge.

[A study on the effect of dynorphin A- (1-13) ICV injection on water, sodium and potassium excretion of rats]

The effect of Kappa-agonist dynorphin A-(1-13) on the urine flow was studied in ethanol-anesthetized rats. Intracerebroventricular injection of dynorphin A- (1-13) (5 micrograms, 10 micrograms) induced a potent diuretic response with insignificant action on mean arterial pressure and heart rate. The diuretic response began to show at about 20 min after injection and lasted 120 min. This diuretic effect could be almost completely blocked by pretreatment with naloxone (20 micrograms) or atropine (10 micrograms).

Geographic pathology on the precursors of stomach cancer

The classification of dysplasias of the gastric mucosa used in our institute includes adenomatous dysplasia, regenerative dysplasia, and cryptal dysplasia. We compared the incidence of gastric dysplasia in three regions of China which have quite different geographical environments: the loess plateau of Wuwei area in the Gansu Province, the island of the Yangtze River in the Jiangsu Province of southern China, and the coastal area of the Liaoning Province in northern China. The mortality rate of stomach cancer in these areas is more than 50 per 100,000. We found a total of 323 cases of gastric dysplasia in these three areas. Regenerative dysplasia is the most common precancerous lesion of the stomach and was found in 40% of the cases from the three high-risk areas of gastric cancer. The background lesions consist of gastric erosions, severe gastritis, gastric ulcers, and intestinal metaplasia, which indicate that some factors causing damage to gastric mucosa are very important in the histogenesis of stomach cancer. The gastric dysplasia sites involved are different in the three geographical regions studied. On the island of the Yangtze River, cardiac dysplasia and intestinal metaplasia are common (75%), and cancer of the cardia is also common. In the other two geographical areas, antral dysplasia predominates (85 to 91%). The finding of different sites of gastric dysplasia in different geographical environments may be very important in our search for etiological factors of gastric cancer and may allow for beneficial intervention in the prevention of this disease.

Geographic survey of cancer in China

Cancer incidence in China shows characteristics related to geographic distribution, ecological factors, dietary and nondietary habits, lifestyles and living conditions, and occupational factors. The random interaction of these factors resulted in a markedly uneven distribution of each of the major types of cancer throughout China. This article reviews the main types of cancer found in China in relation to their relevant epidemiological factors.

Effects of berbamine on contraction and Ca2+ influx of pig basilar artery

Effects of berbamine (Ber) on KCl- and 5-HT-induced contraction of basilar artery (BA) of pigs were studied in vitro. Ber relaxed markedly KCl-induced contraction of BA (IC50 = 4.63 mumol.L-1) and its effect was antagonized by increasing the concentration of extracellular Ca2+; Ber inhibited 5-HT-induced contraction of BA, showing significant inhibition of sustained tonic contraction (STC) (IC50 = 0.64 mumol.L-1) whereas the initial fast phasic contraction (FPC) was relatively unaffected (IC50 = 19.8 mumol.L-1); the 5-HT-induced contraction of BA was dependent on the concentration of extracellular Ca2+, especially STC. The results of Ca2+ withdrawal and replacement indicated that STC was due to 5-HT-stimulated Ca2+ influx, while 5-HT-induced release of intracellular Ca2+ resulted in FPC. Ber 0.8 mumol.L-1 produced markedly inhibitory effect on Ca2+ influx induced by 5-HT (P < 0.01). The effects of Ber were similar to those of nimodipine (Nim). The present results suggested that Ber has antagonistic effect on the potential sensitive channels (PSC) and the receptor operated channels (ROC).

Radioimmunolocalization of human gastric carcinoma xenografts SY 86 B and SY 86 D with 131I-labeled monoclonal antibody

The suitability of individual MAb for application in vivo should be carefully confirmed. The monoclonal antibody GL-013, with specific binding reactivity in vitro to human tumors of the gastrointestinal tract, was radioiodinated and injected intraperitoneally into nude mice bearing human gastric carcinoma xenografts SY 86 B (moderately differentiated glandular adenocarcinoma) and SY 86 D (signet ring cell carcinoma). Whole body scintigraphy indicated tumor localization with 131I-labeled MAb GL-013, but not with 131I-labeled normal mice immunoglobulin. The best tumor contrast was obtained between days 3 and 7 after injection. As confirmation of the imaging results, 131I-GL-013 preferentially localized in tumor tissue compared with normal tissue and 131I-GL-013 gave a higher tumor uptake ratio than the control 131I-NMIgG (at day 9 after injection), as determined by tissue counting of radioactivity. These results demonstrate that MAb GL-013 localizes in xenografts SY 86 B and SY 86 D and the possible clinical application of MAb GL-013 to radioimmunolocalization.

Clinical studies on bladder tumor-associated antigen in serum of patients with bladder cancer by using monoclonal antibody and sandwich ELISA

Investigations on tumor-associated antigen in the serum of patients with bladder cancer by using monoclonal antibody Hb 7A and sandwich ELISA were carried out on 36 patients with bladder cancer (BCa group), 18 patients with other tissue tumor (OTT group) and 22 normal subjects (control group). The average OD value of Hb 7A antigen of BCa group, OTT group and control group was 0.315 +/- 0.033, 0.124 +/- 0.026 and 0.12 +/- 0.021 respectively. The OD value of Hb 7A antigen in BCa group was significantly higher than that of control group and of OTT group (P less than 0.01), but there was no obvious difference between the control group and OTT group (P greater than 0.05). The positive detection rate in BCa group was 86% (31/36), while detection in all 22 normal subjects and the 18 patients of OTT group yielded negative results. The results indicated that the method of using McAb Hb 7A and sandwich ELISA, characterized by high specificity and sensitivity, is of value for clinical diagnosis and follow-up of patients with bladder cancer and general survey of persons at high risk of bladder cancer.