[Relationship between maternal nutritional stetus and intrauterine growth retardation with neonatal visual development disorder]

OBJECTIVE

To investigate the relationship between the maternal nutritional stetus and the occurrence of intrauterine growth retardation (IUGR) with neonatal visual development disorder.

METHODS

Sixty pregnant women closed to expected date of confinement were randomly divided into 2 groups: IUGR and normal control group, each were with 30 cases. Eight kinds of nutritional foods taken by the pregnant women were investigated and scored. The vitamin A concentrations of maternal and umbilical blood were measured with fluorometer method. The concentrations of iron, copper and zinc in maternal and umbilical blood were detected by spectrophotometer. The results of examination with Flash-visual evoked potentials (F-VEP) were recorded by an experienced technician in neonates at 3-7 days after birth and 10 months after follow-up.

RESULTS

Compared with the normal control, the IUGR group had taken less eggs, animal liver and fat pork during pregnancy (P < 0.05), had remarkable lower concentrations of vitamin A and iron in maternal and umbilical blood (P < 0.01), and had a lower umbilical blood zinc concentration (P < 0.05). Meanwhile, neonates with IUGR had obvious delay of the latent period of F-VEP's main positive component (P100) (P < 0.05) and an attenuation of the P100 with when it was measured at 3-7 days after birth and at 10th month after fellow-up (P < 0.01).

CONCLUSION

The decreased intake of foods rich in vitamin A, iron, zinc and other nutritional components was closely correlated with IUGR occurrence and resulted in retardation of neonate visal development.

Trapping of 1,8-biradical intermediates by molecular oxygen in photocycloaddition of naphthyl-N-(naphthylcarbonyl)carboxamides; formation of novel 1,8-epidioxides and evidence of stepwise aromatic cycloaddition

The photocycloaddition reaction of naphthyl-N-(naphthylcarbonyl)carboxamides (1) was examined under argon and oxygen atmospheres. In addition to the [2 + 2] and [4 + 4] cycloadducts, 3 and 4, respectively, novel 1,8-epidioxides (5) were formed under oxygen atmosphere. The transient absorption at lambda max of 360 nm with the lifetime of 360 ns was observed by laser flash photolysis of 1c and was interpreted as the absorption of biradical intermediate 2. On the basis of the anti stereochemistry of 5, which was different from that of the major [4 + 4] cycloadducts, syn-4, it was deduced that equilibrium between biradical intermediates syn-2 and anti-2 would exist. Retro [2 + 2] cycloaddition of 3 was responsible for the efficient trapping of the biradical intermediate with molecular oxygen. The photocycloaddition of the anthryl derivatives, 9-anthryl-N-(methylethyl)-N-(naphthylcarbonyl)carboxamides (7), afforded the [4 + 4] cycloadducts (8) exclusively in a quantitative yield even under oxygen atmosphere. The absence of trapping with molecular oxygen was interpreted to be due to the lack of retro [4 + 4] cycloaddition of 8.

Amperometric ultramicrosensors for peroxynitrite detection and its application toward single myocardial cells

The research studied the concentration variation of peroxynitrite anion (O=N-O-O-) released from cultured neonatal myocardial cells induced by ischemia/reperfusion and studied the protective effect of melatonin on the injury. For this purpose, amperometry peroxynitrite ultramicrosensors (UMS) were fabricated and constructed by electropolymerizing inorganic macromolecular film of tetraaminophthalocyanine manganese(II) and coating chemically with poly(4-vinylpyridine). Under optimum conditions, the UMS showed high selectivity and sensitivity to peroxynitrite determination with a calculated detection limit of 1.8 x 10(-8) mol/L (S/N of 3). The detection of peroxynitrite was based on electrocatalytic reduction of peroxynitrite. The mechanism of catalysis was also discussed. The UMS should be promising for in vivo measurement of peroxynitrite without interference or fouling. Peroxynitrite released from myocardial cells both in the ischemic period and in the reperfusion period was measured directly. This approach may lead to important information for myocardial cells on the mechanism of injury and prospective treatments of medicine such as melatonin.

[The study of induced circular dichroism of phenylalanine bridged metal bis-porphyrin]

L- and D-phenylalanine bridged zinc bis-porphyrin with the connecting chain at ortho and para position of two phenyl rings [o,o-C2-Phe-C2-(TPP)2Zn2 and p,p-C2-Phe-C2-(TPP)2Zn2] have been synthesized and characterized. o,o-C2-Phe-C2-(TPP)2Zn2 exhibited strong induced circular dichroism (ICD). While p,p-C2-Phe-C2-(TPP)2Zn2 exhibited no significant ICD. The ICD of present complexes were mainly determined by the pi-pi interaction and chiral excition coupling between two porphyrin moieties of the molecules. Our results also indicated that the existence of chiral center in a porphyrin molecule does not mean it would surely exhibit ICD.

Measurement of nitric oxide released in the rat heart with an amperometric microsensor

Nitric oxide (NO) plays an important role in various physiological processes, acting either as an intra- and intercellular messenger or as a toxic agent. The detection and quantification of NO have been accomplished by a variety of methodologies. In the present study, real-time production of NO in the rat heart was continuously measured by using a novel copper-platinum microparticle-modified NO electrochemical microsensor. The linearity range of the microsensor is between 8.0 x 10(-8) and 4.8 x 10(-6) mol L-1 and the detection limit is 3.0 x 10(-8) mol L-1. NO release from the rat heart stimulated by the agonists L-arginine and acetylcholine was observed, and the responses were decreased by the NO synthase inhibitor L-N omega-nitroarginine. In addition, the effect of sodium nitroprusside (SNP), a NO donor, was also studied. SNP increases the concentration of NO in the rat heart. The experiments showed that electrochemical detection is suitable for detecting and quantifying NO in biological systems.

[Ca(2+)](i) oscillations regulate type II cell exocytosis in the pulmonary alveolus

Pulmonary surfactant, a critical determinant of alveolar stability, is secreted by alveolar type II cells by exocytosis of lamellar bodies (LBs). To determine exocytosis mechanisms in situ, we imaged single alveolar cells from the isolated blood-perfused rat lung. We quantified cytosolic Ca(2+) concentration ([Ca(2+)](i)) by the fura 2 method and LB exocytosis as the loss of cell fluorescence of LysoTracker Green. We identified alveolar cell type by immunofluorescence in situ. A 15-s lung expansion induced synchronous [Ca(2+)](i) oscillations in all alveolar cells and LB exocytosis in type II cells. The exocytosis rate correlated with the frequency of [Ca(2+)](i) oscillations. Fluorescence of the lipidophilic dye FM1-43 indicated multiple exocytosis sites per cell. Intracellular Ca(2+) chelation and gap junctional inhibition each blocked [Ca(2+)](i) oscillations and exocytosis in type II cells. We demonstrated the feasibility of real-time quantifications in alveolar cells in situ. We conclude that in lung expansion, type II cell exocytosis is modulated by the frequency of intercellularly communicated [Ca(2+)](i) oscillations that are likely to be initiated in type I cells. Thus during lung inflation, type I cells may act as alveolar mechanotransducers that regulate type II cell secretion.

alpha(v)beta(3) integrin induces tyrosine phosphorylation-dependent Ca(2+) influx in pulmonary endothelial cells

The endothelial alpha(v)beta(3) integrin occurs luminally, where its ligation by soluble agents may induce inflammatory signaling. We tested this hypothesis in bovine pulmonary artery endothelial cell monolayers with the use of vitronectin and cross-linking antibodies to ligate and aggregate the integrin. We quantified the endothelial cytosolic Ca(2+) concentration ([Ca(2+)](i)) according to the Fura 2 ratio imaging method in single cells of confluent monolayers. At baseline, endothelial [Ca(2+)](i) levels remained steady at 86 nmol/L for >20 minutes. Cross-linking of the alpha(v)beta(3) integrin through the sequential exposure of monolayers to anti-alpha(v)beta(3) monoclonal antibody LM609 and secondary IgG resulted in a [Ca(2+)](i) increase of 100% above baseline. This increase commenced in <0.5 minute, peaked in <2 minutes, and decayed to baseline in approximately 5 minutes. Similar responses occurred after the addition of vitronectin (400 microg/mL). In contrast, external Ca(2+) depletion blunted the cross-linking-induced [Ca(2+)](i) increase by 60%, a response that was completely inhibited when the monolayers were also pretreated with thapsigargin. Thus, the [Ca(2+)](i) increase was attributable in part to the release of Ca(2+) from endosomal stores but mostly to Ca(2+) influx across the plasma membrane. Induced aggregation of the alpha(v)beta(3) integrin enhanced tyrosine phosphorylation of phospholipase C-gamma1 and increased the accumulation of inositol-1, 4,5-trisphosphate. Genistein, a broad-spectrum tyrosine kinase inhibitor, abrogated both of these effects, as well as the alpha(v)beta(3)-induced [Ca(2+)](i) increases. We conclude that aggregation of the endothelial alpha(v)beta(3) integrin induces a rapid tyrosine phosphorylation-dependent increase in [Ca(2+)](i). This response may subserve the inflammatory role of alpha(v)beta(3) integrin in blood vessels.

A single high dose of vitamin C counteracts the acute negative effect on microcirculation induced by smoking a cigarette

Cigarette smoking is associated with marked acute changes in microcirculation including reduced blood flow. We tested the hypothesis that the reduced blood flow velocity is due to the imbalance between prooxidants and antioxidants that occurs as a consequence of smoking and that it can be reduced by an antioxidant. The effect of smoking a single cigarette on nail-fold microcirculation was analyzed in 24 healthy subjects with varying smoking habits. Vital capillary microscopy was used and the blood cell flow velocity in the capillaries was evaluated before and 1-30 min after smoking. Smoking induced a marked decrease in microcirculatory blood flow in 23 of the 24 subjects (40-50% decrease 1-5 min after smoking). This change was reduced by more than 50% in the same subjects after intake of 2 g of vitamin C 2 h before smoking (P < 0.0001 by ANOVA test) with smokers responding similarly to nonsmokers in these experiments. Intake of 1 g of vitamin C had no significant effect on the smoking-induced changes in most of the subjects tested (n = 11). Pretreatment with aspirin had little or no effect on the response to smoking (n = 9). Our results show that treatment with a single high dose of vitamin C can reduce and in some individuals even completely abolish the negative acute effect on microcirculation induced by smoking a single cigarette. This effect of vitamin C is not likely to be mediated by the cyclooxygenase system.

Pressure is proinflammatory in lung venular capillaries

Endothelial responses may contribute importantly to the pathology of high vascular pressure. In lung venular capillaries, we determined endothelial [Ca(2+)](i) by the fura-2 ratioing method and fusion pore formation by quantifying the fluorescence of FM1-43. Pressure elevation increased endothelial [Ca(2+)](i). Concomitantly evoked exocytotic events were evident in a novel spatial-temporal pattern of fusion pore formation. Fusion pores formed predominantly at vascular branch points and colocalized with the expression of P-selectin. Blockade of mechanogated Ca(2+) channels inhibited these responses, identifying entry of external Ca(2+) as the critical triggering mechanism. These endothelial responses point to a proinflammatory effect of high vascular pressure that may be relevant in the pathogenesis of pressure-induced lung disease.

[The relation between placental pathologic changes and serum nitric oxide levels of maternal and umbilical blood in intrauterine growth retardation]

OBJECTIVE

To study the relation between placental pathologic changes and levels of maternal and umbilical serum nitric oxide (NO) in intrauterine growth retardation (IUGR).

METHODS

38 patients with IUGR (IUGR group) and 30 healthy pregnant women in their late trimester (control group) were studied from Nov. 1997 to Oct. 1998. The placenta and the appendages of fetus were studied after delivery. The concentration of serum NO were determined with cortas' method.

RESULTS

Placental pathological changes were found in 26 cases of IUGR group (68.42%), and the main pathological changes were growth retardation of villi and villositis. In the control group, 5 out of 30 cases had placental pathological findings (16.67%). There was statistically significant difference between the 2 groups (P < 0.01). In IUGR group, the maternal and umbilical NO concentration in the 26 cases with placental pathological changes decreased significantly when compared with that in 12 cases without obvious pathological findings of placenta (P < 0.05, P < 0.05); NO levels of umbilical cord were higher than that of maternal serum in both groups(P < 0.01, P < 0.05); There was correlation about serum NO concentration between mother and her fetus in both groups (r = 0.5475, r = 0.8506); but umbilical serum NO level was not related to the weight of the newborn (r = 0.2838).

CONCLUSION

The obvious placental pathologic changes occurred in patient with IUGR caused noticeably lower NO levels in maternal and umbilical serum.

Vitamin C reduces cholesterol-induced microcirculatory changes in rabbits

The microcirculation was studied for 10 weeks in untreated rabbits (n = 12) and in rabbits treated with vitamin C in their drinking water (0.5 g/d; n = 6), a 1% cholesterol diet (n = 12), or a combination of the two treatments (n = 11). The studies were performed by direct intravital microscopic imaging of the conjunctiva of both eyes to evaluate blood flow velocity, microvessel diameter, and microhemorheologic conditions. As we reported previously, changes occurred in all of the aforementioned variables as a consequence of cholesterol feeding. After 3 and 6 weeks of feeding, there was a marked and significant (P < .0001) decrease in blood flow velocity in third-order arterioles, which was accompanied by stasis and erythrocyte aggregation in the smaller conjunctival vessels. When cholesterol treatment was combined with vitamin C, blood flow was almost identical to that of controls and significantly (P < .0001) higher than that of rabbits treated with cholesterol alone. All other changes were also significantly reduced by the addition of vitamin C treatment to the cholesterol diet. Cholesterol-treated rabbits developed macroscopic arterial lesions that were not significantly reduced by vitamin C treatment. Neither circulating oxysterol levels nor atheromas were reduced by vitamin C treatment, which also had no significant effect on lipid or circulating vitamin E levels. We have previously shown that the lipid-soluble antioxidant BHT is able to prevent both cholesterol-induced microcirculatory changes and the development of arterial lesions in rabbits. This phenomenon is compatible with a critical oxidation step occurring in the lipid phase that is common to both processes. The finding that microcirculatory changes can be prevented by a water-soluble antioxidant is compatible with a role for water-soluble oxidants in this context. The possibility is discussed that vitamin C might also be important for the microcirculation in humans.

Ca2+ waves in lung capillary endothelium

Although cytosolic Ca2+ importantly regulates organ function, lung microvascular [Ca2+]i regulation remains poorly understood because of the lack of direct in situ quantification. In the present study, we report the first endothelial [Ca2+]i quantification by the fura 2 method in microscopically imaged venular capillaries of the isolated blood-perfused rat lung. Sequential images indicated the presence of intercellular Ca2+ waves that spontaneously originated from pacemaker endothelial cells and then spread for short distances along the capillary wall, inducing synchronous endothelial [Ca2+]i oscillations. Fast Fourier analyses of the oscillations revealed a dominant wave component with an amplitude of 37 nmol/L, frequency of 0.4 min-1, and velocity of 5 microns/s. The intracellular Ca2+ wave was unaffected by blood flow stoppage or by infusions of Ca(2+)-containing or Ca(2+)-free dextran. Inhibition of the wave by thapsigargin in Ca(2+)-free dextran and by the gap junction uncoupler, heptanol, indicated that it was generated by endosomal Ca2+ release in the pacemaker cell and was propagated by gap junctional communication. In the presence of histamine, enhancement of the wave accounted for a significant component of the coordinated [Ca2+]i increase in the capillary segment. No intercellular Ca2+ waves were evident in adjoining alveolar epithelial cells. Our findings indicate a novel mechanism of [Ca2+]i regulation in the lung capillary under both resting and stimulated conditions. Pacemaker-induced Ca2+ waves, generated intracellularly by unknown initiating mechanisms, communicated to adjoining cells to determine [Ca2+]i profiles in short interbranch segments of capillary walls.

Ligation of endothelial alpha v beta 3 integrin increases capillary hydraulic conductivity of rat lung

Complement-mediated pulmonary edema results from increases in lung capillary hydraulic conductivity (Lp), possibly by receptor-mediated mechanisms. We considered the Lp effects of vitronectin and the vitronectin-containing complement complex SC5b-9, which ligate the integrin alpha v beta 3. Vitronectin, SC5b-9, and SC5b-9-enriched zymosan-activated serum all rapidly increased Lp, as determined by the split-drop technique in single lung capillaries of rat lung. The Lp increases were inhibited by a monospecific (LM609) and a polyclonal (R838) antibody against the alpha v beta 3 integrin but not by an irrelevant monoclonal antibody isotype matched with LM609, by a monoclonal antibody against the alpha v beta 5 integrin, or by preimmune rabbit serum. Vitronectin monomers failed to increase Lp. The tyrosine kinase blockers genistein and methyl 2,5-dihydroxycinnamate caused significant concentration-dependent inhibitions of Lp increases due to vitronectin and zymosan-activated serum. By contrast, the protein kinase C blocker calphostin C had no major effect. We conclude that (1) multivalent ligation of the luminally located alpha v beta 3 integrin of lung capillary endothelium increases transcapillary liquid flux, and (2) the dominant signal transduction pathway for this effect occurs through tyrosine kinase activation.

Improvement of fusing ability of human sperm to zona-free hamster eggs by conditioned media

A conditioned medium (CM) was prepared by culturing human sperm at 3.0 x 10(6) sperm/ml for 12 h. The fusion index increased significantly when the sperm penetration assay (SPA) was performed with CM (0.6 without CM to 2.0 with CM). The conditioned medium was also effective on the sperm from 11 patients who showed a low or zero value in SPA and who's in vitro fertilization treatment failed. When CM from the sperm of healthy donors was added to these patients' sperm, the fusing ability to zona free hamster eggs was significantly restored.

Removal of albumin microinjected in rat lung perimicrovascular space

We used a microinjection approach to assess hydraulic properties of lung perimicrovascular adventitia (interstitial cuff surrounding microvessels). Isolated blood-perfused rat lungs held at constant airway pressure were microscopically viewed to identify subpleural venules (20 microns diam). Venular adventitia were microinjected with 20 nl of fluorescent albumin (4 g/dl), and then adventitial fluorescence was quantified at the injection site by either photometery or imaging. Nonlinear decay of adventitial fluorescence indicated liquid flux from the injection site into normal interstitium. In some experiments, we determined that the adventitial fluorescence flowed longitudinally along the venule length and filled single lymphatics. The fluorescence decay at the injection site was best described by equations of convective but not diffusive transport. The decay time constant (time to 37% initial), which relates inversely to hydraulic conductivity, increased 10-fold above baseline on lung expansion with airway pressure from 5 to 15 cmH2O (P < 0.05). However, presence or absence of blood flow, increase in filtration pressure, and tissue edema were all without effect on the time constant. Our estimate of the lower limit of baseline adventitial hydraulic conductivity was 5 x 10(-6) ml.cm-2.s-1.cmH2O-1. We conclude that hydraulic conductivity of perimicrovascular adventitia is not augmented by edema but that it is decreased by lung expansion.