Effects and mechanisms of vaginal electrical stimulation on gastric tone in dogs

Electrical stimulation of one part of the gut may have beneficial or adverse effects on another region. We hypothesized that electrical stimulation of a visceral organ in one system might have an effect on another visceral organ system. That is, disorders of one system may be treated by interventions of another system and this may lead to a more convenient or less invasive therapies in some cases. The aim of this study was to evaluate the effects and mechanisms of vaginal electrical stimulation (VES) with different parameters on gastric tone and gastric slow waves in conscious dogs. Seven dogs were studied in two experiments. Experiment 1 was to study effects of VES on gastric tone and slow waves. Experiment 2 was performed in two sessions (long pulse VES plus guanethidine and VES with trains of long pulse plus guanethidine) to study involvements of possible sympathetic mechanisms. The results of our experiments were: (i) VES increased the gastric volume in a dose-dependent manner with the increase of stimulation frequency, amplitude or pulse width; (ii) VES had no effects on gastric slow waves; (iii) the inhibitory effect of VES with long pulses or trains of long pulses on gastric tone was abolished by guanethidine; and (iv) few or mild symptoms were noted with stimulation. VES decreases proximal gastric tone in an energy-dependent manner without affecting gastric slow waves. The inhibitory effect of VES is mediated by a sympathetic pathway. Hypertensive gastric tone might be treated using electrical stimulation of the vagina which is minimally invasive.

Clinical significance of Epstein-Barr Virus DNA load detected pre- and post-radiotherapy in nasopharyngeal carcinoma patients

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Background: Plasma Epstein-Barr virus DNA (EBV DNA) load has been shown to be clinically useful in the detection, monitoring, and prognostication of nasopharyngeal carcinoma (NPC). However, the clinical significance of EBV DNA load detected at different time points has not been addressed to our knowledge. In this study, we investigated whether pre- and post-treatment plasma EBV DNA load have different prognostic implications in NPC patients who were treated with radiotherapy. Methods: Plasma samples from 69 patients with primary NPC were collected before and after radiation treatment, and subjected to a real-time quantitative polymerase-chain- reaction assay of EBV DNA load. The pre-treatment primary tumor volume (GTVnx) calculated through CT images and/or MRI were documented. All patients were scheduled to follow up. Results: The pre-treatment plasma EBV DNA concentration was significantly associated with primary tumor volume (Spearman correlation coefficient=0.614; P=0.000). With a cutoff value of 20,000 copies/ml and 0 copies/ml respectively for pre-treatment and post-treatment plasma EBV DNA copy number, patients with lower EBV DNA concentrations had statistically preferable progression-free survival,metastasis-free survival and overall survival compared with those with higher EBV DNA concentrations. Cox regression analysis demonstrated that both pre-treatment EBV DNA load (P=0.050;RR=3.95) and post-treatment EBV DNA load (P=0.001;RR=11.74) were risk factors for metastasis-free survival. When further integrating pre-treatment with post-treatment concentration of EBV DNA, it was demonstrated that whether EBV DNA concentration could be dropped to 0 after treatment dominate the prognostic effect for metastasis-free survival (P=0.000). Conclusions: Pre- and post-treatment plasma EBV DNA have different clinical significance. Pre-treatment plasma EBV DNA is a reliable molecular marker reflecting primary tumor volume. While the clearance of circulating plasma EBV DNA after treatment is a good predictive marker of freedom from distant metastasis.

No significant financial relationships to disclose.

Predictive significance of bone sialoprotein and osteopontin for bone metastases in respectable non-small cell lung cancer: A retrospective study

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Background: Bone sialoprotein (BSP) and osteopontin (OPN) have been demonstrated predictive of bone metastases in breast and prostate carcinoma, consistent with the proposed role of BSP as a stimulator of bone mineralization and OPN in differentiation and activation of osteoclasts. Bone metastasis (BM) is often developed in non-small-cell lung cancer (NSCLC), but no predictive biomarker was identified for high risk of metastatic bone dissemination. Methods: 180 completely resected NSCLC patients were included in this study. 38 patients subsequently developed BM. Paraffin embedded primary tumor tissue of patients were supplied to produce a tissue microarray, and immunohistochemistry method was used for evaluation the expression of BSP and OPN. Different expressions of these two biomarkers among BM group and non-BM group were estimated by χ2 test. Bone metastasis-free survival was analyzed by Kaplan-Meier method. The prognostic impact of clinicopathologic parameters and biomarker expression was evaluated by Cox propotional hazards model. Results: BSP expression was associated with BM (P=0.027), while OPN expression could not reach statistical significance (P=0.495). Univariate analysis demonstrated that expression of BSP (P=0.036), N stage (P=0.000) and clinical stage (P=0.001) were associated with time interval to BM. Multivariate analyses showed BSP expression (RR=1.779, P=0.012) and clinical stage (RR=1.620, P=0.005) were independent prognostic factors for BM. Conclusions: BSP protein expression in the primary resected NSCLC is strongly associated with BM and could be used to identify high-risk patients. Correlation of OPN protein expression and bone metastasis need further investigation.

No significant financial relationships to disclose.

Effect of nitinol wire surface properties on albumin adsorption

The superelastic, shape memory alloy nitinol ( approximately 50% nickel and approximately 50% titanium) is an important medical device material used for stent applications. However, the role specific surfaces properties have in protein adsorption remain controversial. In this study the effects of nitinol wire surface roughness, hydrophobicity and elemental composition upon albumin adsorption are investigated. In particular, we demonstrate that the technique of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in the so-called surface mode can be used for the direct detection of albumin on the wire surfaces. In addition, albumin adsorbing to the wires was determined by using (125)I-labelled albumin. Albumin was detected on all wire samples. Surface roughness and hydrophobicity appeared to have no effect on albumin adsorption. There was however a clear correlation between the surface nickel and oxygen concentration and the amount of albumin adsorbed. Samples with higher levels of nickel and less oxygen in the surface oxide layer of the wires showed increased albumin adsorption, which could lead to improved biocompatibility. However, nickel is a toxic substance and can cause many adverse effects on humans, and thus nitinol with a slightly enriched surface nickel concentration that does not exhibit nickel release may have potential as a medical device material.

Efficacy and efficiency of gastric electrical stimulation with short pulses in the treatment of vasopressin-induced emetic responses in dogs

The aim of this study was to determine the most effective and efficient anti-emetic parameters of short-pulse gastric electrical stimulation (GES) in dogs. Seven female beagle dogs implanted with four pairs of gastric electrodes were studied in eight randomized sessions (saline, vasopressin, and six GES sessions with different parameters). Each session consisted of four 20-min recordings of gastric slow waves and symptoms. In sessions 1 and 2, saline and vasopressin, respectively, were infused during the second 20-min period. The protocol of the other six sessions was the same as session 2 except that GES was continuously applied. It was found that: (1) vasopressin induced gastric dysrhythmia and emetic response (P < 0.01, anova); (2) short-pulse GES with a frequency of 14 or 40 Hz and pulse width of 0.1 or 0.3 ms, but not 0.6 ms was able to reduce symptoms induced by vasopressin; (3) short-pulse GES with a pulse width of 0.3 ms was the most effective in preventing vasopressin-induced symptoms; (4) none of the tested GES methods improved vasopressin-induced gastric dysrhythmia. We conclude that vasopressin induces gastric dysrhythmia and symptoms. Short-pulse GES with a pulse width of 0.3 ms and frequency of 14 Hz is most effective and efficient in preventing vasopressin-induced emetic responses in dogs.

The method of surface PEGylation influences leukocyte adhesion and activation

The influence of different surface modifications with poly(ethyleneglycol) (PEG) layers on the adsorption of fibrinogen and the adhesion and activation of macrophage-like human leukocytes was investigated. Poly(ethylene terephthalate) (PET) was modified using pulsed AC plasma polymerization with two types of starting monomers to generate: 1) a reactive acid surface using maleic anhydride (MAH) as monomer, and 2) a PEG-like surface using diethyleneglycol methyl vinyl ether (DEGVE) as monomer. The MAH surface was used as a reactive platform to graft linear chains of non-fouling mPEG via an intermediate layer of poly(ethyleneimine) (PEI) under lower critical solution temperature (LCST) conditions of the mPEG. The DEGVE monomer is used to create PEG-like layers by use of low power plasma conditions. The ability of the surfaces to resist protein adsorption was investigated quantitatively using (125)I-radiolabeled human fibrinogen, and the conformation of the adsorbed protein was tested using an anti-fibrinogen monoclonal antibody in an enzyme-linked immunosorbent assay. The results showed that PEGylated surfaces adsorbed significantly less (up to 90% less) fibrinogen, and that unfolding of adsorbed fibrinogen was more pronounced on the linear mPEG layers than on the PEG-like plasma polymer surfaces. Adhesion of in-vitro differentiated macrophage-like U937 cells was reduced on both the PEG-like plasma polymer surfaces and the linear mPEG layers compared to the unmodified PET surface, but cells adhering to the PEG-like plasma polymer surfaces secreted less tumor necrosis factor-alpha (TNF-alpha) than cells adhering to the linear mPEG layers. In conclusion, the method for preparing non-fouling surfaces for long-term implanted devices influence surface-induced cellular responses of the host.

SEA0400, a novel Na+/Ca2+ exchanger inhibitor, reduces calcium overload induced by ischemia and reperfusion in mouse ventricular myocytes

Given the potential clinical benefit of inhibiting Na+/Ca2+ exchanger (NCX) activity during myocardial ischemia reperfusion (I/R), pharmacological approaches have been pursued to both inhibit and clarify the importance of this exchanger. SEA0400 was reported to have a potent NCX selectivity. Thus, we examined the effect of SEA0400 on NCX currents and I/R induced intracellular Ca2+ overload in mouse ventricular myocytes using patch clamp techniques and fluorescence measurements. Ischemia significantly inhibited inward and outward NCX current (from -0.04+/-0.01 nA to 0 nA at -100 mV; from 0.23+/-0.08 nA to 0.11+/-0.03 nA at +50 mV, n=7), Subsequent reperfusion not only restored the current rapidly but enhanced the current amplitude obviously, especially the outward currents (from 0.23+/-0.08 nA to 0.49+/-0.12 nA at +50 mV, n=7). [Ca2+]i, expressed as the ratio of Fura-2 fluorescence intensity, increased to 138+/-7% (P<0.01) during ischemia and to 210+/-11% (P<0.01) after reperfusion. The change of NCX current and the increase of [Ca2+]i during I/R can be blocked by SEA0400 in a dose-dependent manner with an EC50 value of 31 nM and 28 nM for the inward and outward NCX current, respectively. The results suggested that SEA0400 is a potent NCX inhibitor, which can protect mouse cardiac myocytes from Ca2+ overload during I/R injuries.

Cardio-ankle vascular index (CAVI) for the monitoring of the atherosclerosis after heart transplantation

Atherosclerosis has been reported to progress rapidly after heart transplantation. A quantitative diagnosis is required for the diagnosis of atherosclerosis after heart transplantation. In this study, we compared brachial-ankle pulse wave velocity (baPWV) and cardio-ankle vascular index (CAVI) for the diagnosis. The average values of both baPWV and CAVI in the seven cases after heart transplantation were found to be signif-icantly large in comparison to the average values of the normal healthy people of the same age group. When comparisons were made before and after the heart transplantation in a particular case, CAVI was stable and baPWV changed sharply. A lot of parameters such as blood pressure, blood volume, etc. have been reported to influence baPWV. The results of this study suggested that CAVI was a stable parameter in comparison to baPWV even after heart transplantation. Thus, CAVI may be useful in the diagnosis of arteriosclerosis after heart transplantation.

Design, synthesis and in vitro and in vivo antitumor activities of novel β-carboline derivatives

To further our SAR study on the chemistry and antitumor activity/neurotoxicity of beta-carboline alkaloids, several series of beta-carboline derivatives with various substituents were designed and synthesized from the starting material l-tryptophan on the basis of harmine chemical structure. Cytotoxic activities of these compounds were investigated in vitro. The results showed that some beta-carboline derivatives had significant cytotoxic activities against human tumor cell lines. Among all the synthesized beta-carboline derivatives, the compounds 27, 28 and 32, having a benzyl substituent at both position-2 and 9, respectively, were found to be the most potent compounds with IC50 value lower than 50 microM against all human tumor cell lines examined. Acute toxicities and antitumor activities of the selected beta-carboline derivatives in mice were also evaluated. The results demonstrated that a benzyl substituent at position-2 increased the antitumor activity as well as acute toxicity significantly. However an (ethoxycarbonyl)amino substituent at position-3 reduced the acute toxicity as well as antitumor activity remarkedly. These data suggested that (1) the antitumor potencies of beta-carboline derivatives were enhanced by the introduction of benzyl substituent into the position-2; (2) the acute toxicity of beta-carboline derivatives reduced dramatically by the introduction of an appropriate substituent into the position-3 and 9; (3) the beta-carboline structure might be an important basis for the design and synthesis of new antitumor drugs with significant antitumor activity and low toxicity.

A defective nontransmissible recombinant Sendai virus mediates efficient gene transfer to airway epithelium in vivo

Recombinant Sendai virus (SeV)-mediated gene transfer to differentiated airway epithelial cells has shown to be very efficient, because of its ability to overcome the intra- and extracellular barriers known to limit gene delivery. However, this virus is transmission competent and therefore unlikely to be suitable for use in clinical trials. A nontransmissible, replication-competent recombinant SeV has recently been developed by deleting the envelope Fusion (F) protein gene (SeV/DeltaF). Here we show that SeV/DeltaF is able to mediate beta-galactosidase reporter gene transfer to the respiratory tract of mice in vivo, as well as to human nasal epithelial cells in vitro. Further, in an ex vivo model of differentiated airway epithelium, SeV/DeltaF gene transfer was not importantly inhibited by native mucus. When compared to the transmission-competent SeV in vivo, no difference in gene expression was observed at the time of peak expression. The development of an F-defective nontransmissible SeV, which can still efficiently mediate gene transfer to the airway epithelium, represents the first important step towards the use of a cytoplasmic RNA viral vector in clinical trials of gene therapy.

Interaction between nitric oxide and prostanoids in arterioles of rat cremaster muscle in vivo

We studied in vivo interactions of nitric oxide (NO), oxidative stress, and prostanoids derived from the cyclooxygenase pathway in the arterioles studied by intravital microscopy in peripheral muscle. Topical administration of NO synthase (NOS) inhibitor Nomega-nitro-l-arginine (l-NNA) or cyclooxygenase inhibitor mefenamic acid (MA) alone leads to vasoconstriction. We found that l-NNA after MA induced an additional constriction, whereas MA after l-NNA induced a relative dilation. Therefore, an additional constriction was found when MA was administered after l-NNA in the presence of the thromboxane A2 synthase-PGH2 (TP) receptor antagonist SQ-29548. We also found a relative dilation when the TP receptor antagonist was administered after NOS inhibition by l-NNA. In the presence of superoxide dismutase and catalase, l-NNA-induced vasoconstriction is reduced, and the dilation observed after addition of MA in presence of the reactive oxygen species is no longer present. Taken together, these results showed that NO inhibition induced a shift in the synthesis or in the effects of cyclooxygenase products, in favor of constrictor prostanoids. This effect of NO inhibition disappears when reactive oxygen species are scavenged by superoxide dismutase and catalase.

Thermal evolution of the Cl(-)-LiAl(2) layered double hydroxide: a multinuclear MAS NMR and XRD perspective

Layered double hydroxides (LDHs) with a cation composition of LiAl(2) have a wide range of potential applications as catalysts, catalyst supports, and precursors for refractory oxide materials, including several industrially important lithium aluminate phases. The understanding of the calcination behavior of this group of LDH phases is essential to advancing these applications, and the research described here focuses on the thermal decomposition and structural evolution of LiAl(2)(OH)(6)Cl.nH(2)O in the temperature range of 20-1100 degrees C. (27)Al, (35)Cl, and (6,7)Li magic angle spinning nuclear magnetic resonance spectroscopy, powder X-ray diffraction, thermal analysis (including thermogravimetric and differential scanning calorimetry), and compositional analysis provide a highly consistent picture of the thermally induced phase formation and transformations of this LDH. The loss of the surface and interlayer water can begin as low as room temperature, depending on the relative humidity. Beginning at about 300 degrees C, the simultaneous volatilization of H(2)O and HCl and the exsolution of crystalline LiCl result in the formation of amorphous Li-Al-O-OH. By at least 500 degrees C, volumes with the structures of alpha-LiAlO(2) and LiAl(5)O(8) appear, and these phases become progressively more ordered with increasing temperature. LiCl begins to volatilize by 850 degrees C and is present only in trace amounts above ca. 1000 degrees C. alpha-LiAlO(2) converts to gamma-LiAlO(2) between 970 and 1100 degrees C. Because of the delithiation due to LiCl volatilization, the final products are dominated by LiAl(5)O(8), in contrast to the calcination products of previously studied LiAl(2) LDHs which are dominated by LiAlO(2).

Prevalence and clinical characteristics of mitochondrial tRNAleu(UUR) nt 3243 A-->G and nt 3316 G-->A mutations in Chinese patients with type 2 diabetes

Seven hundred and sixteen randomly selected, unrelated patients with type 2 diabetes were screened for mutations using a PCR-RFLP technique to assess the prevalence of the A-G mutation at position 3243 of the mitochondrial (mt) tRNAleu(UUR) gene in type 2 diabetes in the Chinese population. Three individuals with this mutation were identified, representing approximately 0.4% of the type 2 diabetes patients screened. Further screening of the first-degree relatives of these three patients identified another four affected carriers. In comparison with type 2 diabetic patients without the mutation, these seven carriers of the mt 3243 mutation had; (1) had an earlier onset of diabetes (38.0+/-10.1 vs. 53.4+/-10.0 year, P<0.001); (2) a lower body mass index (BMI) (19.5+/-2.0 vs. 24.9+/-10.9, P<0.0001); and (3) and lower post-challenge insulin levels (area under the curve of insulin levels during the OGTT, 2946+/-1647.2 vs. 7469+/-6647.7, P<0.01). In addition, the same 716 patients with type 2 diabetes, as well as 181 controls with normal glucose tolerance, were screened for a newly described mt 3316 G-A mutation. This mutation was found in 16 patients with type 2 diabetes (2.2%) and five controls (2.7%). Therefore, the frequency of the mutation was not significantly different in the patients and controls. Moreover, the clinical characteristics such as the age of the onset of diabetes, the BMI, and insulin levels were not significantly different between the diabetic patients with the mt 3316 G-A mutation and those without. This shows that the mt 3316 G-A mutation is a polymorphism unrelated to diabetes.

Prevalence and clinical characteristics of mitochondrial tRNA leu(UUR) mt 3243 A-->G and ND-1 gene mt 3316 G-->A mutations in Chinese patients with type 2 diabetes

OBJECTIVE

To assess the prevalence of mitochondrial tRNA leu(UUR) gene mt 3243 A-->G mutation and ND-1 gene mt 3316 G-->A mutation in Chinese type 2 diabetes.

METHODS

716 randomly selected, unrelated patients with type 2 diabetes were screened for the mutation with a PCR-RFLP technique.

RESULTS

Three individuals with mitochondrial tRNA leu(UUR) gene mt 3243 A-->G mutation were identified, representing approximately 0.4% of the type 2 patients screened. Further screening of first-degree relatives of these 3 patients identified another 4 affected carriers. In comparison with type 2 diabetic patients without the mutation, these 7 carriers of the mt3243 mutation had: 1) an earlier diagnosis age of diabetes (38.0 +/- 10.1 year vs 53.4 +/- 10.0 year, P < 0.001); 2) lower Body Mass Index (BMI) (19.5 +/- 2.0 kg/m2 vs 24.9 +/- 10.9 kg/m2, P < 0.0001); and 3) lower post-challenge insulin levels (Area under the curve of insulin levels during the Oral Glucose Tolerance Test (OGTT), 2946 +/- 1647.2 microIU.ml-1 vs 7469 +/- 6647.7 microIU.ml-1, P < 0.01). ND-1 gene mt 3316 G-->A mutation was found in 16 patients with type 2 diabetes (2.2%) and 5 out 181 controls (2.7%) with normal glucose tolerance. Therefore, the frequency of the mutation was not different in patients and controls. Moreover, clinical characteristics such as age of onset of diabetes, BMI, and insulin levels were not different between diabetic patients with the mt 3316 mutation and those without it.

CONCLUSIONS

In this large cohort of Chinese Type 2 diabetes, the prevalence of mitochondrial tRNA leu(UUR) gene mt 3243 A-->G mutation was 0.4%, and the ND-1 gene mt 3316 G-->A mutation is a polymorphism unrelated to diabetes.

Prostanoid receptors: ontogeny and implications in vascular physiology

Prostanoids exert significant effects on circulatory beds. They play a role in the response of the vasculature to adjustments in perfusion pressure and oxygen and carbon dioxide tension, and they mediate the actions of numerous factors. The role of prostanoids in governing circulation of the perinate is suggested to surpass that in the adult. Prostanoids are abundantly generated in the perinate. They have been implicated in autoregulation of blood flow as studied in brain and eyes. Prostaglandins are also dominant regulators of ductus arteriosus tone. The effects of these autacoids are mediated through specific G protein-coupled receptors. In addition to the pharmacological characterization of the prostanoid receptors, important advances in understanding the biology of these receptors have been made in the last decade. Their cloning and the development of animals with disrupted genes of these receptors have been very informative. The involvement of prostanoid receptors in the developing subject, especially on brain and ocular vasculature and on ductus arteriosus, has also begun to be investigated; the expression of these receptors changes with development. Some but not all of the ontogenic changes in these receptors are attributed to homologous regulation. Interestingly, in the process of elucidating their effects, functional perinuclear prostaglandin E2 receptors have been uncovered. This article reviews prostanoid receptors and addresses implications on the developing subject with attention to vascular physiology.

Major role for neuronal NO synthase in curtailing choroidal blood flow autoregulation in newborn pig

We examined whether nitric oxide (NO) generated from neuronal NO synthase (nNOS) contributes to the reduced ability of the newborn to autoregulate retinal blood flow (RBF) and choroidal blood flow (ChBF) during acute rises in perfusion pressure. In newborn pigs (1-2 days old), RBF (measured by microsphere) is autoregulated over a narrow range of perfusion pressure, whereas ChBF is not autoregulated. N(G)-nitro-L-arginine methyl ester (L-NAME) or specific nNOS inhibitors 7-nitroindazole, 3-bromo-7-nitroindazole, and 1-(2-trifluoromethyl-phenyl)imidazole as well as ganglionic blocker hexamethonium, unveiled a ChBF autoregulation as observed in juvenile (4- to 6-wk old) animals, whereas autoregulation of RBF in the newborn was only enhanced by L-NAME. All NOS inhibitors and hexamethonium prevented the hypertension-induced increase in NO mediator cGMP in the choroid. nNOS mRNA expression and activity were three- to fourfold higher in the choroid of newborn pigs than in tissues of juvenile pigs. It is concluded that increased production of NO from nNOS curtails ChBF autoregulation in the newborn and suggests a role for the autonomic nervous system in this important hemodynamic function, whereas, for RBF autoregulation, endothelial NOS seems to exert a more important contribution in limiting autoregulation.

Repellent effect of pea (Pisum sativum) fractions against stored-product insects

Peas (Pisum sativum) are toxic to some stored-product insects. The repellent effect of fractions of pea seed to stored-product insects was evaluated in multiple-choice tests in which wheat kernels were dusted with fractions rich in either protein, fibre or starch at 0.001 to 10% (wt:wt). There was a negative correlation between pea protein concentration and the number of adults found in grain for Cryptolestes ferrugineus and Sitophilus oryzae, but not for Tribolium castaneum. Pea fibre repelled C. ferrugineus adults but not S. oryzae and T. castaneum. Pea starch did not repel any of the insects. One-week old and 6-week old C. ferrugineus were equally repelled by pea protein. Repellency was detectable 1h after exposure. Cryptolestes ferrugineus and S. oryzae did not become habituated to the repellent action of pea protein even after 4 weeks of exposure. Habituation was observed, however, when C. ferrugineus was exposed to pea fibre for 4 weeks. In a two-choice bioassay (0 vs. 0.1% and 0 vs. 1% pea protein), the pea-protein-treated grain had significantly fewer insects (C. ferrugineus, S. oryzae, Sitophilus zeamais, T. castaneum, and Tribolium confusum) than untreated grain. The properties of the pea protein fractions seem well suited for developing a natural stored grain protectant.

ER and PR in renomedullary interstitial cells during Syrian hamster estrogen-induced tumorigenesis: evidence for receptor-mediated oncogenesis

The estrogen-induced and -dependent Syrian hamster renal tumor is the most intensively studied model in estrogen carcinogenesis. Yet, it remains confounding that the kidney of this species behaves as an estrogen target tissue. As both reproductive and urinary systems arise from the same germinal ridge, we propose that some of the germinal cells, normally destined for the uterus, migrate and establish themselves in the renal corticomedullary region in this hamster strain. These ectopically located germinal cells remain dormant unless exposed to estrogen. Supporting this contention, a subset of renal interstitial cells, primarily located in the corticomedullary region, express PR after only 2 wk and ER alpha after 1.5--3.0 months of estrogen treatment. As treatment continues, groups of cells of the renal interstitium and small and large renal tumors show ER alpha(+) and PR(+) staining. Although ER alpha and PR isoform profiles in estrogen-treated hamster kidneys are distinctly different from corresponding uterine patterns, both receptor isoform profiles in primary renal tumors closely resemble those seen in hamster uteri. Renal ER alpha protein and mRNA expression increased after 2.0 and 4.0 months of estrogen treatment and in all renal tumors examined. Using nuclear image cytometry, both early small and large renal tumors were highly aneuploid, indicating that genomic instability is probably a critical early event in estrogen carcinogenesis.

Molecular recognition in a reconstituted tumor cell membrane

The design of an immunoliposome system for molecular recognition using reconstituted, hydrogel-supported bilayer lipid membranes (sb-BLMs) is described. By monitoring the electrical properties, two kinds of recognition are feasible: (i) the human bladder tumor cells, Ej and its antibody BDI-1, the lifetime of the reconstituted membrane is 42 min; and (ii) the human rectum tumor cells, LOVO, the life of the reconstructed membrane is more than 40 min, the same as conventional BLM. Further, the anticancer drug, Adriamycin (Anticancer Res., 20 (2000) 1391), was shown to be effective in such reconstituted systems, the life of which is less than 5 min. In these experiments, the active ingredients of the Ej and LOVO cells were determined on reconstituted sb-BLMs. The key point is that the component part being recognized on the BLM must be kept in its native state.

NMDA receptor activation results in tyrosine phosphorylation of NMDA receptor subunit 2A(NR2A) and interaction of Pyk2 and Src with NR2A after transient cerebral ischemia and reperfusion

Transient ischemia increases tyrosine phosphorylation of N-methyl-D-aspartate (NMDA) receptor. Several tyrosine kinases are involved in this process. In this study, effect of ischemia and reperfusion (I/R) on tyrosine phosphorylation of NMDA receptor subunit 2A (NR2A) and the interaction of two tyrosine kinases, Src and Pyk2, with NR2A was investigated. Four-vessel occlusion was used to produce transient (15 min) cerebral ischemia in SD rats. Tyrosine phosphorylation of NR2A in hippocampus was enhanced after 15 min of reperfusion and reached its peak level at 6 h of reperfusion. The increase sustained for at least 24 h. Src and Pyk2 co-immunoprecipitated with NR2A and the binding increased after I/R, which also reached a peak at 6 h of reperfusion. Besides, Src and Pyk2 were activated after I/R. These increases were prevented by ketamine, a selective NMDA receptor antagonist, which was administered to the SD rats 20 min before ischemia. Moreover, Src and Pyk2 coprecipitated with each other. These data show that NR2A, Src and Pyk2 might form a protein complex in vivo and the interaction suggests a possible mechanism of signal transduction in the postischemic hippocampus.

2,3-Dinor-5,6-dihydro-15-F(2t)-isoprostane: a bioactive prostanoid metabolite

15-F(2t)-isoprostane (15-F(2t)-IsoP), also termed 8-isoprostaglandin F(2alpha), is one of a series of prostanoids formed by free radical-mediated peroxidation of arachidonic acid and exerts potent biological actions such as vasoconstriction. We recently demonstrated that 15-F(2t)-IsoP is metabolized in humans to a major metabolite, 2,3-dinor-5,6-dihydro-15-F(2t)-IsoP (15-F(2t)-IsoP-M). 15-F(2t)-IsoP-M can also potentially be formed as a product of free radical-induced oxidation of the low abundance fatty acid gamma-linolenic acid. We confirmed that 15-F(2t)-IsoP-M is generated during oxidation of gamma-linolenic acid and explored whether it may exhibit biological activity. 15-F(2t)-IsoP-M caused marked constriction of porcine surface retinal and intraparenchymal brain microvessels, comparable to that observed with 15-F(2t)-IsoP. These effects were associated with increased thromboxane A(2) (TXA(2)) formation and were virtually abolished by TXA(2)-synthase and -receptor inhibitors (CGS-12970 and L-670596). Vasoconstriction induced by either 15-F(2t)-IsoP or 15-F(2t)-IsoP-M on perfused ocular choroid was also abrogated by TXA(2)-synthase inhibition as well as by removal of endothelium. Similar to 15-F(2t)-IsoP, 15-F(2t)-IsoP-M evoked vasoconstriction and TXA(2) generation by activating Ca(2+) influx from nonvoltage-gated channels (SK&F96365 sensitive) in the retina and from both nonvoltage- and N-type voltage-gated Ca(2+) channels (omega-conotoxin MVIIA sensitive), respectively, in brain endothelial and astroglial cells; smooth muscle cells were unresponsive to both agents. Cross-desensitization experiments further suggest that 15-F(2t)-IsoP and 15-F(2t)-IsoP-M act on the same receptor mechanism. Findings reveal a novel concept by which a beta-oxidation metabolite of 15-F(2t)-IsoP that can also be formed by nonenzymatic oxidation of gamma-linolenic acid is equivalently bioactive to 15-F(2t)-IsoP and may prolong the vascular actions of F(2)-IsoPs.

Retrograde interlocking intramedullary nailing under arthroscopy for supracondylar femoral fracture

OBJECTIVE

To evaluate the therapeutic effects of retrograde interlocking intramedullary nailing under arthroscopy on supracondylar femoral fractures.

METHODS

From June 1999 to December 2000, 17 patients with supracondylar femoral fracture were treated with arthroscopically assisted implantation of retrograde interlocking intramedullary nail and close reduction.

RESULTS

More than 6-month follow-up study after operation in 11 patients revealed that the average healing time was 3 months. Average range of the knee motion for all the patients was more than 90 degrees. There was no implant breakage and infection.

CONCLUSIONS

This new method, combining the advantage of arthroscope and retrograde interlocking intramedullary nail, can provide a stable and reliable fixation, and meanwhile is less invasive to the soft tissue and knee, less operative time and blood loss, minimal disruption of the blood supply in fracture site. It is conducive to the fracture healing and the functional recovery of the knee joint and worthwhile to be recommended.

Role of thromboxane in retinal microvascular degeneration in oxygen-induced retinopathy

Microvascular degeneration is an important event in oxygen-induced retinopathy (OIR), a model of retinopathy of prematurity. Because oxidant stress abundantly generates thromboxane A2 (TxA2), we tested whether TxA2 plays a role in retinal vasoobliteration of OIR and contributes to such vascular degeneration by direct endothelial cytotoxicity. Hyperoxia-induced retinal vasoobliteration in rat pups (80% O2 exposure from postnatal days 5-14) was associated with increased TxB2 generation and was significantly prevented by TxA2 synthase inhibitor CGS-12970 (10 mg x kg(-1) x day(-1)) or TxA2-receptor antagonist CGS-22652 (10 mg x kg(-1) x day(-1)). TxA2 mimetics U-46619 (EC50 50 nM) and I-BOP (EC50 5 nM) caused a time- and concentration-dependent cell death of neuroretinovascular endothelial cells from rats as well as newborn pigs but not of smooth muscle and astroglial cells; other prostanoids did not cause cell death. The peroxidation product 8-iso-PGF2, which is generated in OIR, stimulated TxA2 formation by endothelial cells and triggered cell death; these effects were markedly diminished by CGS-12970. TxA2-dependent neuroretinovascular endothelial cell death was mostly by necrosis and to a lesser extent by apoptosis. The data identify an important role for TxA2 in vasoobliteration of OIR and unveil a so far unknown function for TxA2 in directly triggering neuroretinal microvascular endothelial cell death. These effects of TxA2 might participate in other ischemic neurovascular injuries.

Skeletal muscle regeneration after insulin-like growth factor I gene transfer by recombinant Sendai virus vector

We scrutinized the applicability and efficacy of Sendai virus (SeV) vectors expressing either LacZ or human insulin-like growth factor-I (hIGF-I) in gene transfer into skeletal muscle. Seven days after the intramuscular injection of LacZ/SeV X-gal labeled myofibers were demonstrated in rat anterior tibialis muscle with/without bupivacaine treatment and the transgene expression persisted up to 1 month after injection. Recombinant hIGF-I was detected as a major protein species in culture supernatants of a neonatal rat myoblast cell line L6 and thus induced the cells to undergo myogenetic differentiation. The introduction of hIGF-I/SeV into the muscle showed a significant increase in regenerating and split myofibers which were indicative of hypertrophy, and also an increase in the total number of myofibers, in comparison to that seen in the LacZ/SeV-treated control muscle. These results demonstrate that SeV achieves high-level transgene expression in skeletal muscle, and that hIGF-I gene transfer using SeV vector may therefore have great potential in the treatment of neuromuscular disorders.

Feeding suppression by fibroblast growth factor-1 is accompanied by selective induction of heat shock protein 27 in hypothalamic astrocytes

It has been suggested that fibroblast growth factor (FGF)-1 serves as a physiological satiety factor in the hypothalamus, although the molecular mechanism underlying such a function is poorly understood. To gain additional insight into this issue, we used a Sendai virus (SeV) gene expression system in rats to explore genes differentially expressed subsequent to expression of FGF-1. Using cDNA arrays, we determined that infusion of FGF-1/SeV into one lateral ventricle induced selective expression of heat shock protein (HSP) 27 in the hypothalamus. Whereas FGF-1 expression was restricted to the ependymal cell layer of the cerebral ventricles, HSP27 was more widely expressed in astrocytes residing in the surrounding periventricular region. Similarly, infusion of FGF-1 polypeptide into a lateral ventricle induced dose-dependent HSP27 expression in periventricular astrocytes surrounding the third ventricle, with maximum mRNA levels being attained 6 h after infusion. This induction of HSP27 was accompanied by a significant suppression of feeding behaviour. Interestingly, suppression of feeding caused by intracerebro ventricular infusion of ciliary neurotrophic factor was also accompanied by induction of HSP27 in periventricular astrocytes, but suppression of feeding caused by infusion of leptin was not. It therefore appears that suppression of feeding by FGF-1 is accompanied by selective induction of HSP27 expression in hypothalamic astrocytes surrounding the third ventricle, and that this response may be a key component of the mechanism by which appetite is regulated by FGF-1.

[Observation on the kinetic process in replantation of the recurrent laryngeal nerve of the dog]

OBJECTIVE

In order to provide experimental foundation for replantation in the recurrent laryngeal nerve(RLM) of the laryngeal reconstruction and laryngeal transplantation.

METHOD

The left RLN of ten caine dogs were cut. The histopathology of the cut RLN were observed under the microscope after operation (two dogs) and 3.5 hours later (two dogs). Meanwhile the RLN were sewed up under the microscope at once. The kinetic process in regeneration of the RLN were observeded 1 week (two dogs), 2 week (two dogs) and 4 week (two dogs) after the replantation.

RESULT

The replantation of RLN of six dogs succeeded.

CONCLUSION

The results confirmed that sewing up the cut RLN at once is helpful to get normal regeneration in the replantation.

[Landscape changes of ecotone of temperate and sub-tropical zone and its ecological importance]

The change process of ecotone of temperate and subtropical zone and its effect on development, transformation and permeation of chinese agriculture and techniques were discussed in this paper from the viewpoint of landscape ecology. In historical time, the boundary of the ecotone changed northward and southward as climate changed, which changed southward 1-2 latitude in cold period and northward 1-2 latitude in warm period. The ecotone had an obvious environment diversity and strong sensibility, and played important role as a landscape conduit and barrier in aspects of chinese agricultural heterogeneous permeation and heterogeneity creation of agricultural techniques and cultures.

[Genetic diversity of Fagoyrum tataricum cultivated in north Liangshan Prefecture of Yi Nationality, Sichuan, China]

In the present paper is stated the accomplishment of the studies of 17 populations of cultivated Fagopyrum tataricum (L.) Gaertn. from the counties of Yuexi and Ganluo in North Liangshan Autonomous Prefecture of Yi Nationality, Sichuan Province, China by means of starch gel electrophoresis and cluster analysis of agrobiology features. Seven enzymes, and 15 loci were assessed. The result shows that the genetic diversity of F. tataricum within population is higher than in the South Prefecture and in species F. esculentum from other areas. The A, P, Ho and He are 1.9, 52.1%, 0.190 and 0.262 respectively. The FST is 0.199 which is close to the average level of wild plants. A conservation strategy of the genetic resource of F. tataricum is suggested. Two populations of local variety "Youchiqiao" have the richest genetic diversity, P = 60.0%, Ho = 0.260 and 0.301 and they should be protected particularly. Two populations of local variety "Xiaomiqiao" with higher genetic diversity, as well as three populations of local varieties of "Qiukuqiao", "Equkuqiao" and "Geluokuqiao" with special genetic position should be protected too.

[Genetic diversity and differentiation of cultivated Fagoyrum tataricum populations from three counties in south Liangshan Automomous Prefecture of Yi Nationality, Sichuan, China]

Genetic diversity and differentiation among 8 cultivated populations of Fagopyrum tataricum from the counties of Jinyang, Leibo and Miyi in south Liangshan Autonomous Prefecture of Yi Nationality, Sichuan Province, China were investigated using allozyme electrophoresis. The allozymic diversity is roughly correlated with agrobiological features. The results suggest that genetic diversity of F. tataricum is quite high. The mean number of alleles per locus A is 1.8; the percentage of polymorphic loci P is 46.6%, and the mean observed heterozygosities Ho and the mean expected heterozygosities He are 0.187 and 0.218 respectively, the ratios of gene diversities of heterozygosities Fsr is 0.22, which indicates that there is 22 percent of genetic differentiation among populations, and suggests that for protecting genetic resources all the populations should be included in.

Effect of the vacuolation of Helicobacter pylori

Cytotoxic test in vitro combined with cytochemical stain, fluorescent stain, transmission electronmicrograph was used to study the vacuolated effect by helicobacter pylori (H. pylori) (Toxin+) and its pathological mechanism. 78.26% patients with peptic ulcer associated with H. pylori was infected with H. pylori (Toxin+), while 42.86% patients with gastritis was infected with H. pylori (Toxin+). It was positive in vacuole with acridine orange and acid phosphatase stain. Transmission electronmicrograph of vacuole revealed the presence of abounding membrane. There was a closed relationship between infection with H. pylori (Toxin+) and peptic ulcer disease. The vacuole induced by H. pylori (Toxin+) was autophagosome, which was pathological phenomenon induced by toxin.

Tungsten coil devices in atomic spectrometry: absorption, fluorescence, and emission

In this work, tungsten coil (W-Coil) devices are used as atomizers for electrothermal atomization atomic absorption spectrometry (ETAAS), electrothermal atomization laser excited atomic fluorescence spectrometry (ETA-LEAFS), and electrothermal vaporization inductively coupled plasma atomic emission spectrometry (ETV-ICP-AES). For most cases in ETAAS and ETA-LEAFS, limits of detection (LODs) using the W-Coil are within a factor of ten of those observed with commercial graphite furnace systems. LOD for Cd by W-Coil AAS is 10 pg, while LODs for As, Se, Cr, Sb and Pb by W-Coil LEAFS are 950, 320, 1400, 330, and 160 fg, respectively. The compact W-Coil device makes it an ideal atomizer for portable atomic spectrometry instrumentation, especially when coupled with a miniature charge coupled device spectrometer. Alternatively, the atomizer can be used as an inexpensive, modular add-on to an existing commercial ICP-AES system; and the thermal separation of Pb with interference elements Al, Mn, and Fe is demonstrated.

Prolonged hypercapnia-evoked cerebral hyperemia via K(+) channel- and prostaglandin E(2)-dependent endothelial nitric oxide synthase induction

Mechanisms for secondary sustained increase in cerebral blood flow (CBF) during prolonged hypercapnia are unknown. We show that induction of endothelial NO synthase (eNOS) by an increase in prostaglandins (PGs) contributes to the secondary CBF increase during hypercapnic acidosis. Ventilation of pigs with 6% CO(2) (PaCO(2 approximately)65 mm Hg; pH approximately 7.2) caused a approximately 2.5-fold increase in CBF at 30 minutes, which declined to basal values at 3 hours and gradually rose again at 6 and 8 hours; the latter increase was associated with PG elevation, nitrite formation, eNOS mRNA expression, and in situ NO synthase (NOS) reactivity (NADPH-diaphorase staining). Subjecting free-floating brain sections to acidotic conditions increased eNOS expression, the time course of which was similar to that of CBF increase. Treatment of pigs with the cyclooxygenase inhibitor diclofenac or the NOS inhibitor Nomega-nitro-L-arginine blunted the initial rise and prevented the secondary CBF increase during hypercapnic acidosis; neuronal NOS blockers 1-(2-trifluoromethylphenyl) imidazole and 3-bromo-7-nitroindazole were ineffective. Diclofenac abolished the hypercapnia-induced rise in cerebrovascular nitrite production, eNOS mRNA expression, and NADPH-diaphorase reactivity. Acidosis (pH approximately 7.15, PCO(2 approximately )40 mm Hg; 6 hours) produced similar increases in prostaglandin E(2) (PGE(2)) and eNOS mRNA levels in isolated brain microvessels and in NADPH-diaphorase reactivity of brain microvasculature; these changes were prevented by diclofenac, by the receptor-operated Ca(2+) channel blocker SK&F96365, and by the K(ATP) channel blocker glybenclamide. Acidosis increased Ca(2+) transients in brain endothelial cells, which were blocked by glybenclamide and SK&F96365 but not by diclofenac. Increased PG-related eNOS mRNA and NO-dependent vasorelaxation to substance P was detected as well in rat brain exposed to 6 hours of hypercapnia. PGE(2) was the only major prostanoid that modulated brain eNOS expression during acidosis. Thus, in prolonged hypercapnic acidosis, the secondary CBF rise is closely associated with induction of eNOS expression; this seems to be mediated by PGE(2) generated by a K(ATP) and Ca(2+) channel-dependent process.

Unusual deregulation of cell cycle components in early and frank estrogen-induced renal neoplasias in the Syrian hamster

There is strong evidence that estrogens are involved in the etiology, promotion and progression of a variety of cancers, including the cancers of the breast and endometrium. The Syrian hamster estrogen-induced, estrogen-dependent renal neoplasm is a well-established animal model used to elucidate the cellular and molecular mechanisms involved in solely estrogen-induced carcinogenic processes. G(1) cell cycle progression was studied in estrogen-induced early renal tumor foci and in large kidney tumors of castrated male hamsters. Levels of cyclin D1, cyclin E and retinoblastoma (pRb) proteins were higher in these renal neoplasias than in adjacent uninvolved renal tissue and kidneys from untreated, age-matched animals. Of particular interest is the presence of a predominant 35 kDa cyclin E protein variant form in primary renal tumors. In addition, amounts of the phosphorylated forms of cyclin-dependent kinases (cdk) 2 and 4 were decreased, and both RNA and protein levels of p27(kip1) (p27), a cyclin-dependent kinase inhibitor, were markedly higher in early and frank renal tumors than in adjacent uninvolved renal tissue and kidneys of untreated, age-matched animals. These changes in cell cycle components coincided with a rise in renal tumor cell proliferation. Binding of the elevated p27 protein to cyclin E, cdk2 and cdk4, however, was not impaired, suggesting that this cell cycle suppressor protein is functional. In addition, cyclin D1-, cdk2-, cdk4- and cyclin E-associated kinase activities were also lower in these estrogen-induced renal neoplasms than in untreated, age-matched kidneys. Interestingly, when compared with untreated kidney tissue, early and frank renal neoplasms had less of the 62 kDa native form of E2F1 and contained a 57 kDa variant form. Thus we have characterized an unusual deregulation of the cell cycle during estrogen-induced renal tumorigenesis in Syrian hamsters which still allows for estrogen-driven kidney tumor cell proliferation and may contribute to the early genomic instability found.

The human T-cell leukemia virus type I (HTLV-I) X region encoded protein p13(II) interacts with cellular proteins

Interactions between the Human T-cell leukemia virus type I (HTLV-I) gene product p13(II) and cellular proteins were investigated using the yeast two-hybrid system. Variant forms of p13(II) were derived from two HTLV-I molecular clones, K30p and K34p, that differ in both virus production and in vivo and in vitro infectivity. Two nucleotide differences between the p13 from K30p (p13K30) and K34p (p13K34) result in a Trp-Arg substitution at amino acid 17 and the truncation of the 25 carboxyl-terminal residues of p13K34. A cDNA library from an HTLV-I-infected rabbit T-cell line was screened with p13K30 and p13K34 as bait. Products of two cDNA clones, C44 and C254, interacted with p13K34 but not with p13K30. Interactions were further confirmed using the GST-fusion protein coprecipitation assay. Sequence analysis of C44 and C254 cDNA clones revealed similarities to members of the nucleoside monophosphate kinase superfamily and actin-binding protein 280, respectively. Further analysis of the function of these two proteins and the consequence of their interaction with p13 may help elucidate a role for p13 in virus production, infectivity, or the pathogenesis of HTLV-I.

Oxidants, nitric oxide and prostanoids in the developing ocular vasculature: a basis for ischemic retinopathy

The choroid is the main source of oxygen to the retina. In contrast to the adult, the absence of autoregulation of choroidal blood flow in the newborn leads to hyperoxygenation of the retina. In the immature retina which contains relatively low levels of antioxidants this hyperoxygenation favors peroxidation including the generation of biologically active isoprostanes, and results in vasoconstriction and vascular cytotoxicity leading to ischemia, which predisposes to the development of a vasoproliferative retinopathy, commonly termed retinopathy of prematurity. During frequently encountered oxidative stress to the perinate, the combined absence of vascular autoregulation and excessive oxygen delivery to the eyes of the developing subject is largely the result of a complex epigenetic and genetic interplay between prostanoids and nitric oxide (NO) systems on vasomotor regulation. The effects of certain prostaglandins are NO-dependent; conversely, those of NO have also been found to be largely prostaglandin I(2)-mediated in the eye; and NO synthase expression seems to be significantly regulated by other prostaglandins apparently through activation of functional perinuclear prostanoid receptors which affect gene transcription. The increased production of both prostaglandins and NO in the perinate augment ocular blood flow and as a result oxygen delivery to an immature retina partly devoid of antioxidant defenses. The ensuing peroxidation results in impaired circulation (partly thromboxane A(2)-dependent) and vascular integrity, leading to ischemia which predisposes to abnormal preretinal neovascularization, a major feature of ischemic retinopathy. Because tissue oxygenation is largely dependent upon circulation and critical in the generation of reactive oxygen species, and since the latter exert a major contribution in the pathogenesis of retinopathy of prematurity, it is important to understand the mechanisms that govern ocular blood flow. In this review we focus on the important and complex interaction between prostanoid, NO and peroxidation products on circulatory control of the immature retina.

[The first discovery of endemic Lyme disease in Shandong province]

OBJECTIVE

To investigate the endemic area of Lyme disease in Shandong province.

METHODS

An investigation on endemic Lyme disease was conducted by means of serological and etiological methods in Shandong province from 1992 to 1999.

RESULTS

Of 1919 forestry residents, 120 residents had a significant antibody titer against Borolo burgdorferi strain B(31). The prevalance rate of Lyme disease was 6.25%. Haemaphysalis longicornis was a prevailing species of Ixodidae in the region. Spirochetes were observed in the midguts of 50 H. longicornis in this area by direct fluorescence antibody method. The overall positive rate was 12.0% (6/50). Two strains (TSH(1), TSH(3)) of spirochetes were isolated from H. longicornis. Both TSH(1) and TSH(3) were positively responded to McAb H(5332) and H(9724), but negatively to H(6831). Spirochetes were observed in the kidneys of 46 Rattus in this area by direct fluorescence antibody method with a positive rate of 13.26% (6/46).

CONCLUSION

It was the first time that the mountainous areas in Shandong province was confirmed endemic areas of Lyme disease.

[Relations of glycemic control to diabetic nephropathy in patients with non-insulin-dependent diabetes mellitus (NIDDM)--a pair-matched case-control study]

OBJECTIVE

To describe the relations between glycemic control and development of diabetic nephropathy (DN) in patients with non-insulin-dependent diabetes mellitus (NIDDM).

METHODS

A retrospective analysis was carried out on two groups of NIDDM patients, one group without proteinuria (< 300 mg/day, n = 106) and the other group with proteinuria (> or = 500 mg/day, n = 106). The two groups were matched by age <or= +/- 3yrs, sex, race and resident place. Information of these subjects including demographic, history of diseases, family history of diseases, life-style and behavior style was obtained by self-administered questionnaire. Variables including systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), quantity of protein in 24-h urine were measured. Successful glycemic control denoted that the mean value of FBG's surveillance was less than 140 mg/dl after the occurrence of DM (the duration to the development of DN for the patients with DN.). Conditional logistic regression analysis was carried out.

RESULTS

Results from univariate analysis showed that development of proteinuria was associated with glycemic control, the FBG level at diagnosis of NIDDM and the highest FBG level in the past. The corresponding odd ratios (OR) with 95% confidence intervals (CI) were 0.43 (0.25 - 0.75); 1.34 (1.05 - 1.72) and 1.35 (1.07 - 1.70) respectively. When data were adjusted by possible confounding factors, the relation of glycemic control to DN still existed, but the other two relations disappeared.

CONCLUSION

Successful glycemic control decreased the occurrence risk of DN, independent of other risk factors including diabetic duration.

Preservation of neural function in the perinate by high PGE(2) levels acting via EP(2) receptors

Despite increasingly frequent and longer lasting hypoxic episodes during progressive labor, the neonate is alert and vigorous at birth. We investigated whether high levels of PGs during the perinatal period assist in preserving neural function after such "stressful" hypoxic events. Visual evoked potentials (VEPs) and electroretinograms (ERGs) were recorded before and 45 min after mild moderate asphyxic hypoxia (two 4-min asphyxic-hypoxic periods induced by interrupting ventilation at 8-min intervals) in newborn piglets <12 h old treated or not treated with inhibitors of PG synthase (ibuprofen or diclofenac) with or without PG analogs. At 45 min after the hypoxic episode, P2 and b-wave amplitudes were slightly decreased and latencies were delayed. These changes in the VEP and ERG returned to near normal by 120 min. Ibuprofen and diclofenac decreased brain and retinal PG levels and markedly intensified 45 min after hypoxia-induced changes in VEP and ERG, but cerebral and retinal blood flows improved. Combined treatment with PG synthase inhibitor in combination with 16,16-dimethyl-PGE(2) (a PGE(2) analog), but not with PGI(2) and PGF(2alpha) analogs, and in combination with the EP(2) receptor agonist butaprost (but not EP(1) or EP(3) agonists), prevented ibuprofen- and diclofenac-aggravated postasphyxia electrophysiological changes. In conclusion, high levels of PGE(2) in nervous tissue, via actions on EP(2) receptors, seem to contribute to preservation of neural function in the perinate subjected to frequent hypoxic events.

Synthesis and photophysical properties of fluorophore-labeled abscisic acid

The 8'-benzophenone, 8'-dansylhydrazone, 3'-S-(2-ethyldansylamide), and 3'-S-acetamidofluorescein derivatives of the plant hormone abscisic acid (ABA) have been synthesized for use in photoaffinity labeling (the benzophenone derivative) or fluorescence probe experiments and have been spectroscopically characterized. One of the three fluorescent compounds, the 3'-tethered fluorescein derivative, exhibits spectroscopic and photophysical properties which indicate that it could be an excellent fluorescent probe of ABA interactions in vivo. The 3'-tethered fluorescein and ABA moieties do not interact strongly, so that the fluorescence properties of the fluorescein-labelled hormone are very similar to those of fluorescein itself. Measurements of the absorption, emission, and fluorescence excitation spectra, fluorescence quantum yields, and fluorescence decay parameters of this derivative as a function of pH indicate that the photophysics is dominated by ground and excited state prototropic equilibria involving only the fluorescein moiety. The fluorescein dianion is the only significant absorber and emitter at pH > 6.7, whereas only the cation absorbs and emits at pH < 0. In the intervening pH range, strong emission from the monoanion and weak emission from two neutral species, tentatively assigned to the zwitterion and the lactone of the fluorescein moiety, is observed.Key words: abscisic acid, fluorescein, synthesis, photophysics.

Disparity, decimation and the Cambrian "explosion": comparison of early Cambrian and present faunal communities with emphasis on velvet worms (Onychophora)

The controversy about a Cambrian "explosion" of morphological disparity (followed by decimation), cladogenesis and fossilization is of central importance for the history of life. This paper revisits the controversy (with emphasis in onychophorans, which include emblematic organisms such as Hallucigenia), presents new data about the Chengjiang (Cambrian of China) faunal community and compares it and the Burgess Shale (Cambrian of Canada) with an ecologically similar but modern tropical marine site where onychophorans are absent, and with a modern neotropical terrestrial onychophoran community. Biovolume was estimated from material collected in Costa Rica and morphometric measurements were made on enlarged images of fossils. Cambrian tropical mudflats were characterized by the adaptive radiation of two contrasting groups: the vagile arthropods and the sessile poriferans. Arthropods were later replaced as the dominant benthic taxon by polychaetes. Vagility and the exoskeleton may explain the success of arthropods from the Cambrian to the modern marine and terrestrial communities, both in population and biovolume. Food ecological displacement was apparent in the B. Shale, but not in Chengjiang or the terrestrial community. When only hard parts were preserved, marine and terrestrial fossil deposits of tropical origin are even less representative than deposits produced by temperate taxa, Chengjiang being an exception. Nutrient limitations might explain why deposit feeding is less important in terrestrial onychophoran communities, where carnivory, scavenging and omnivory (associated with high motility and life over the substrate) became more important. Fossil morphometry supports the interpretation of "lobopod animals" as onychophorans, whose abundance in Chengjiang was equal to their abundance in modern communities. The extinction of marine onychophorans may reflect domination of the infaunal habitat by polychaetes. We conclude that (1) a mature ecological community structure was generalized during the Cambrian, and even biodiversity and equitability indices were surprisingly close to modern values; (2) the morphological diversity and geographic distribution of onychophorans indicate a significant pre-Cambrian evolutionary history which does not support the "explosion" hypothesis; (3) disparity among phyla was not as important as the explosion-decimation model predicts, but in the case of onychophorans, disparity within the phylum was greater than it is today and its reduction may have been associated with migration into the sediment when large predators evolved.

[Long-term monitoring of artificial vagina reconstructed with sigmoid colon]

OBJECTIVE

To observe the influence of the artificial plastic vagina on overall patient health.

METHODS

Length and width of the artificial vagina were measured. Histological studies were performed under light and electron microscope. Vaginal bacterial flora were analyzed using the drop-implant method. Vaginal HPV and ER were detected with ABC histochemical staining.

RESULTS

According to the results of anatomic measurements, artificial vagina was similar to normal vagina. The reductions of glands in the mucosa and collagen fibers as well as interstitial tissue hyperplasia in the lower segment of artificial vagina were documented. Four kinds of bacteria indigenous to the sigmoid colon were found in artificial vagina and were studied microbiologically with only differences in the amount and detection rates of bacteria flora. The positive presentation of HPV was not significantly different from that in the control group. The positive presentation of estrogen receptor (ER) in the epithelium of artificial vagina was not found.

CONCLUSION

The reconstruction of artificial vagina with sigmoid colon is a safe, effective and satisfactory procedure for the patient.

Iodine-129 in human thyroids and seaweed in China

The concentrations of 129I and the ratios of 129I/127I in normal human thyroids collected in Tianjin, China, and some seaweed samples from the Chinese coast were determined by neutron activation analysis. The mean 129I/127I ratio in these thyroids was found to be 1.13 x 10(-9), which is two orders of magnitude higher than the level of the pre-nuclear era, but one order of magnitude lower than the level in Europe in the post-nuclear era. There is no significant difference between the ratio of 129I/127I in the thyroids for the post-nuclear era from China and other areas, which are considered not to have been directly exposed to 129I emission from a nuclear source, such as Chile, Taiwan and Tokyo. The mean 129I/127I ratio in seaweed from the Chinese coast is 2.35 x 10(-10), approximately two orders of magnitude higher than in seaweed collected in the pre-nuclear age, and similar to that from locations without direct exposure to the emission from nuclear installations, influenced only by global fallout. This indicates that the 129I level in China is within the global fallout background level.

Augmented vasoconstriction and thromboxane formation by 15-F(2t)-isoprostane (8-iso-prostaglandin F(2alpha)) in immature pig periventricular brain microvessels

BACKGROUND AND PURPOSE

Oxidant stress, especially in the premature, plays a major role in the pathogenesis of hypoxic-ischemic encephalopathies mostly manifested in the periventricular region. We studied the vasomotor mode of actions of the peroxidation product 15-F(2t)-isoprostane (15-F(2t)-IsoP) (8-iso-prostaglandin F(2alpha)) on periventricular region during development.

METHODS

Effects of 15-F(2t)-IsoP on periventricular microvessels of fetal, newborn, and juvenile pigs were studied by video imaging and digital analysis techniques. Thromboxane formation and intracellular Ca(2+) were measured by radioimmunoassay and by using the fluorescent indicator fura 2-AM.

RESULTS

15-F(2t)-IsoP-mediated constriction of periventricular microvessels decreased as a function of age such that in the fetus it was approximately 2.5-fold greater than in juvenile pigs. 15-F(2t)-IsoP evoked more thromboxane formation in the fetus than in the newborn, which was greater than that in the juvenile periventricular region; this was associated with immunoreactive thromboxane A(2) (TXA(2)) synthase expression in the fetus that was greater than that in newborn pigs, which was greater than that in juvenile pigs. 15-F(2t)-IsoP-induced vasoconstriction was markedly inhibited by TXA(2) synthase and receptor blockers (CGS12970 and L670596). Vasoconstrictor effects of the TXA(2) mimetic U46619 on fetal, neonatal, and juvenile periventricular microvessels did not differ. 15-F(2t)-IsoP increased TXA(2) synthesis by activating Ca(2+) influx through non-voltage-gated channels in endothelial cells (SK&F96365 sensitive) and N-type voltage-gated channels (omega-conotoxin sensitive) in astrocytes; smooth muscle cells were not responsive to 15-F(2t)-IsoP but generated Ca(2+) transients to U46619 via L-type voltage-sensitive channels.

CONCLUSIONS

15-F(2t)-IsoP causes periventricular brain region vasoconstriction in the fetus that is greater than that in the newborn, which in turn is greater than that in the juvenile due to greater TXA(2) formation generated through distinct stimulatory pathways, including from endothelial and astroglial cells. The resulting hemodynamic compromise may contribute to the increased vulnerability of the periventricular brain areas to oxidant stress-induced injury in immature subjects.

Study on gastric empty disorder after the gastric ulcer healing and therapeutic effect of cisapride

Gastric emptying time of liquid meal was detected by using ultrasonography in 28 gastric ulcer patients with continual or recurrent dyspepsia symptoms after the ulcer healing. Sixteen out of 28 patients (57.1%) with a delay of gastric emptying time (T1/2) were randomly divided into two groups: 8 cases were treated with cisapride 5 mg three times a day and 8 cases with cisapride 10 mg three times a day respectively. The results showed that cisapride could relieve the symptoms with the effective rate being 68.8% in the two groups. T1/2 in the patients after treatment with cisapride was significantly shorter than before treatment (P < 0.001). It was concluded that there is a delay of T1/2 in some patients with gastric ulcer healing. Cisapride could promote gastric empty of liquid meal and relieve the symptoms efficiently. The effect of lower dose of cisapride is similar to that of higher dose.

Regulation of endothelial nitric oxide synthase by PGD(2) in the developing choroid

We investigated if prostaglandins might regulate the increased choroidal endothelial (e) nitric oxide synthase (NOS) expression in the perinate. Prostaglandins, eNOS mRNA, immunoreactive protein and activity, and nitrite [stable metabolite of nitric oxide (NO)] production were markedly higher in newborn (1 day old) than juvenile (6-8 wk old) pig choroid. Treatment of isolated newborn choroids with the prostaglandin synthase inhibitor ibuprofen for 24 h reduced eNOS mRNA and nitrite production to values in juveniles. This effect was equally observed with the PGD(2) receptor (DP) blocker BW A868C and was prevented by cotreatment with PGD(2) but not other prostaglandins; similar observations were made on NOS activity in vivo. PGD(2) also increased eNOS expression on choroids of juveniles, and this effect was blocked by BW A868C. The manifestation of this upregulation of eNOS by PGD(2) on the control of choroidal vasomotor response was tested by using NO-dependent vasorelaxants, ACh, bradykinin (Bk), and substance P (SP). ACh-, Bk-, and SP-elicited choroidal vasorelaxation was greater in saline-treated newborn than juvenile pigs. Ibuprofen (24 h) decreased ACh-, Bk-, and SP-evoked vasorelaxation in newborns, whereas PGD(2) increased that in juveniles and prevented the ibuprofen-induced attenuated relaxation in newborns; infusion of N(omega)-monomethyl-L-arginine in choroids of those animals treated with PGD(2) reversed the augmented vasorelaxation to ACh, Bk, and SP. Finally, PGD(2)-induced upregulation of NOS in the perinate was also reflected by curtailed choroidal blood flow autoregulatory response to increased perfusion pressure. In conclusion, PGD(2) exhibits a major role in upregulating eNOS expression and activity in the choroid, which in turn results in greater NO-mediated vasorelaxation; a new mechanism for eNOS regulation via DP is hereby disclosed. The relationship between PGD(2) and eNOS in the developing subject provides an explanation for the interactive role of these two factors in the absent choroidal blood flow autoregulation in the perinate.

Developmental regulation of endothelial nitric oxide synthase in cerebral vessels of newborn pig by prostaglandin E(2)

We investigated whether prostaglandins regulate endothelial nitric oxide synthase (eNOS) in the pig cerebral vasculature during the neonatal period. Prostaglandins, eNOS mRNA, eNOS protein, and NO production were higher in cerebral microvessels of newborn (1 day old) than in those of adult (6- to 8-month-old) pigs. The treatment of isolated cerebral microvessels of newborn animals with ibuprofen for 24 h reduced eNOS mRNA and nitrite production to levels in the adult; this effect of ibuprofen was prevented by concurrent treatment with prostaglandin (PG)E(2) analog 16,16-dimethyl-PGE(2), nonselective PGE(2) receptor analog 11-deoxy PGE(1), and prostaglandin EP(3) receptor agonists sulprostone and M&B 28,767 but was not modified by PGI(2) analog carbaprostacyclin, PGD(2), and EP(1) receptor agonist 17-phenyl trinor PGE(2). Correspondingly, 16, 16-dimethyl-PGE(2) and M&B 28,767 increased eNOS mRNA expression of adult microvessels to values in the newborn. Data similar to those with isolated cerebral vessels were obtained through histochemical analysis (NADPH-diaphorase positivity) of brain from newborn animals treated in vivo with ibuprofen in combination or not with sulprostone. Furthermore, substance P-induced NO-mediated cerebral vasorelaxation was decreased to adult values through the treatment of newborn pigs with ibuprofen; this effect was prevented by concomitant treatment with sulprostone. It is concluded that PGE(2) regulates eNOS in newborn pig cerebral microvessels via EP(3) receptors; this may be physiologically required during normal neurovascular development.

Developmental changes in prostaglandin E(2) receptor subtypes in porcine ductus arteriosus. Possible contribution in altered responsiveness to prostaglandin E(2)

BACKGROUND

Prostaglandin E(2) (PGE(2)) is important in ductus arteriosus (DA) patency, but the types of functional PGE(2) receptors (EP) in the developing DA are not known. We postulated that age-dependent alterations in EP and/or their subtypes may possibly contribute to the reduced responsiveness of the newborn DA to PGE(2).

METHODS AND RESULTS

We determined PGE(2) receptor subtypes by competition binding and immunoblot studies on the DA of fetal ( approximately 75% and 90% gestation) and newborn (<45 minutes old) pigs. We studied the effects of EP receptor stimulation on cAMP signaling in vitro and on term newborn (<3 hours old) DA patency in vivo. Fetal pig DA expressed EP(2), EP(3), and EP(4) receptors equivalently, but not EP(1). In neonatal DA, EP(1), EP(3), and EP(4) were undetectable, whereas EP(2) density was similar in fetus and newborn. Prostaglandin-induced changes in cAMP mirrored binding data. 16,16-Dimethyl PGE(2) and 11-deoxy PGE(1) (EP(2)/EP(3)/EP(4) agonist) produced more cAMP in fetus than newborn, but butaprost (selective EP(2) agonist) caused similar cAMP increases in both; EP(3) and EP(4) ligands (M&B28767 and AH23848B, respectively) affected cAMP production only in fetus. After birth, administration of butaprost alone was as effective as 11-deoxy PGE(1) and 16,16-dimethyl PGE(2) in dilating DA in vivo.

CONCLUSIONS

The data reveal fewer PGE(2) receptors in the DA of the newborn than in that of the fetus; this may contribute to the decreased responsiveness of the DA to PGE(2) in newborn. Because EP(2) receptors seem to mediate the effects of PGE(2) on the newborn DA, one may propose that a selective EP(2) agonist may be preferred as a pharmacological agent to maintain DA patency in infants with certain congenital heart diseases.