Versatile Fabrication of Polymer Microcapsules with Controlled Shell Composition and Tunable Performance via Photopolymerization

In this work, a series of polymer microcapsules based on UV-curable prepolymers are prepared by combining an emulsion template and photopolymerization. The modulation of the shell structure is achieved by employing UV-curable prepolymers with different chemical structures (polyurethane acrylates, polyester acrylates, and epoxy acrylates) and functionalities (di-, tetra-, and hex-). The relationships between the shell structure and the microcapsule properties are investigated in detail. The results show that the properties of the microcapsules can be effectively regulated by adjusting the composition and cross-linking density of the shell. Epoxy acrylate-based microcapsules exhibit higher impermeability, solvent resistance, and barrier and mechanical properties than polyurethane acrylate and polyester acrylate-based microcapsules. Using UV-curable prepolymer with high functionality as a shell-forming material could effectively improve the impermeability, solvent resistance, and barrier and mechanical properties of microcapsules. In addition, the dispersion of microcapsules in the coating matrix tends to follow the "similar component, better compatibility" principle, i.e., a uniform dispersion of the microcapsule in the coating matrix is more easily achieved when the compositions of the microcapsule shell and coating are similar in structure. The convenient adjustment of the shell structure and the investigation of the "structure-property" relationship provide guidance for the further controlled design of microcapsules.

Full-length transcriptome profiling for fruit development in Diospyros oleifera using nanopore sequencing

OBJECTIVES

Diospyros oleifera, one of the most economically important Diospyros species, is an ideal model for studying the fruit development of persimmon. While, the lack of whole-transcriptome has hindered the complex transcriptional regulation mechanisms of sugar and tannin during fruit development.

DATA DESCRIPTION

We applied Oxford Nanopore Technologies to six developmental stage of fruit from D. oleifera for use in transcriptome sequencing. As a result of full-length transcriptome sequencing, 55.87 Gb of clean data were generated. After mapping onto the reference genome of D. oleifera, 51,588 full-length collapsing transcripts, including 2,727 new gene loci and 43,223 transcripts, were obtained. Comprehensively annotated, 38,086 of new transcripts were functional annotation, and 972 lncRNAs, 7,159 AS events were predicted. Here, we released the transcriptome database of D. oleifera at different stage of fruit development,which will provide a fundamention of to investigatethe transcript structure, variants and evolution of persimmon.

The discovery of a new type of innervation in lymphoid organs

It is well known that the main forms of innervation are synapses and free nerve endings, while other forms of innervation have not been reported. Here, we explore a new way of innervating lymphoid organs. Male Sprague-Dawley rats were used for studying the innervation of sympathetic nerve fibers in lymph nodes by means of anterograde tracking, immunoelectron microscopy, three-dimension reconstruction analysis, and immunofluorescence labeling. The results showed that the Fluoro-Ruby labeled nerve endings targeted only a group of cells in the lymph nodes and entered the cells through the plasma membrane. The electron microscopy showed that the biotinylated glucan amine reaction elements were distributed in the cytoplasm, and most of the biotinylated glucan amine active elements were concentrated on the microtubule and microfilament walls. Birbeck particles with rod-shaped and/or tennis racket like structures can be seen in the labeled cells at high magnification, and Birbeck particles contain biotinylated glucan amine-reactive elements. The immunofluoresence results showed that the Fluoro-Ruby-labeled nerve innervating cells expressed CD207 and CD1a protein. This result confirmed that the labeled cells were Langerhans cells. Our findings suggested that Langerhans cells might serve as a "bridge cell" for neuroimmune cross-talking in lymph organs, which play an important role in transmitting signals of the nervous system to immune system. This study also opened up a new way for further study of immune regulation mechanism.

A facile one-pot strategy for the preparation of porous polymeric microspheres via UV irradiation-induced polymerization in emulsions

In this study, a facile one-pot strategy was developed to prepare porous polymeric microspheres via photopolymerization, where organic solvents functioned as porogens. In this strategy, an oil phase containing organic solvents and photopolymerizable materials was stabilized in water to form a stable oil-in-water emulsion. Upon UV irradiation, the photopolymerizable materials (photosensitive monomers/photosensitive prepolymers) underwent polymerization to form microspheres and the subsequent removal of organic solvents left pores in microspheres, leading to the generation of porous polymeric microspheres with high yielding. The effects of organic solvents and the chemical structure and concentration of photopolymerizable materials on the microsphere structure were systematically explored. It was found that the polarity of the organic solvents played a decisive role in the preparation of porous microspheres. In addition, the increases in the solvent content and functionalities of photopolymerizable materials were more favorable for the generation of porous microspheres. This strategy could be applicable for a wide selection of photopolymerizable materials, which endowed this strategy with good applicability. The preparation of porous microspheres by this method was facile and easy to handle, enabling the scalable preparation of porous microspheres. In addition, the whole process can be completed within a few minutes at ambient temperature, which was time-saving and energy-saving.

Experimental Limits on Exotic Spin and Velocity Dependent Interactions Using Rotationally Modulated Source Masses and an Atomic-Magnetometer Array

Various theories beyond the standard model predict new interactions mediated by new light particles with very weak couplings to ordinary matter. Interactions between polarized electrons and unpolarized nucleons proportional to g_{V}^{N}g_{A}^{e}σ[over →]·v[over →] and g_{A}^{N}g_{A}^{e}σ[over →]·v[over →]×r[over →] are two such examples, where σ[over →] is the spin of the electrons, r[over →] and v[over →] are position and relative velocity between the polarized electrons and nucleons, g_{V}^{N}/g_{A}^{N} is the vector or axial-vector coupling constant of the nucleon, and g_{A}^{e} is the axial-vector coupling constant of the electron. Such interactions involving a vector or axial-vector coupling g_{V}^{N}/g_{A}^{N} at one vertex and an axial-vector coupling g_{A}^{e} at the polarized electron vertex can be induced by the exchange of spin-1 bosons. We report new experimental upper limits on such exotic spin-velocity-dependent interactions of the electron with nucleons from dedicated experiments based on a recently proposed scheme. We rotationally modulated two ∼6  Kg source masses at a frequency of 20 Hz. We used four identical atomic magnetometers in an array form to increase the statistics and cancel the common-mode noise. We applied a data processing method based on high precision numerical integration for the four harmonic frequencies of the signal. We reverse the rotation direction of the source masses to flip the signal due to the new interactions; thus, we can apply the [+1,-3,+3,-1] weighting method to remove possible slow drifting. Our constraint on the product of vector and axial-vector couplings is |g_{V}^{N}g_{A}^{e}|<2.1×10^{-34} and on the product of axial-vector and axial-vector couplings is |g_{A}^{N}g_{A}^{e}|<2.4×10^{-22} for an interaction range of 10 m. The new constraints on vector-axial-vector interaction improved by as much as more than 4 orders of magnitude and on axial-axial interaction by as much as 2 orders of magnitude in the corresponding interaction range, respectively.

Characterization and phylogenetic analysis of the complete mitochondrial genome sequence of Diospyros oleifera, the first representative from the family Ebenaceae

Plant mitochondrial genomes are a valuable source of genetic information for a better understanding of phylogenetic relationships. However, no mitochondrial genome of any species in Ebenaceae has been reported. In this study, we reported the first mitochondrial genome of an Ebenaceae model plant Diospyros oleifera. The mitogenome was 493,958 bp in length, contained 39 protein-coding genes, 27 transfer RNA genes, and 3 ribosomal RNA genes. The rps2 and rps11 genes were missing in the D. oleifera mt genome, while the rps10 gene was identified. The length of the repetitive sequence in the D. oleifera mt genome was 31 kb, accounting for 6.33%. A clear bias in RNA-editing sites were found in the D. oleifera mt genome. We also detected 28 chloroplast-derived fragments significantly associated with D. oleifera mt genes, indicating intracellular tRNA genes transferred frequently from chloroplasts to mitochondria in D. oleifera. Phylogenetic analysis based on the mt genomes of D. oleifera and 27 other taxa reflected the exact evolutionary and taxonomic status of D. oleifera. Ka/Ks analysis revealed that 95.16% of the protein-coding genes in the D. oleifera mt genome had undergone negative selections. But, the rearrangement of mitochondrial genes has been widely occur among D. oleifera and these observed species. These results will lay the foundation for identifying further evolutionary relationships within Ebenaceae.

Preparation of dual-chamber microcapsule by Pickering emulsion for self-healing application with ultra-high healing efficiency

This work presented a new concept for designing dual-chamber self-healing microcapsules, which encapsulated both healing and curing species within a single microcapsule via Pickering emulsion photopolymerization. In our strategy, robust SiO₂ spheres encapsulating curing agent were firstly synthesized and used as Pickering emulsifiers to prepare emulsions loaded with self-healing agent and photo-curable monomer. Upon exposure to UV light, the photo-curable monomer underwent photo-crosslinking and converted into microcapsules wall. In the meanwhile, the SiO₂ spheres encapsulating curing agent were trapped in the microcapsule wall. The dual-chamber microcapsule which loaded the healing agent in its core and curing agent within its shell, was thus prepared. The presence of both the encapsulated healing and curing agent within a single capsule was demonstrated by infrared spectrometry and thermogravimetric analysis. Upon fracture, the healing agent and curing agent are released simultaneously from the dual-chamber microcapsule, which facilitates the interaction of the two agents, and enhances the healing efficiency. Up to 85% healing efficiency of the epoxy resin was achieved in 1 h, which was much higher than that of the traditional double microcapsules self-healing system (65%), demonstrating the excellent self-healing performance of the dual-chamber microcapsules. It has been demonstrated that the coating based on dual-chamber microcapsule presented reliable and outstanding self-healing anti-corrosion efficiency. By changing the species of healing agent, curing agent and wall substances (photo-curable monomer), the as-prepared dual-chamber microcapsules can meet different requirements of versatile self-healing system.

The impact of ultrasonic treatment on blueberry wine anthocyanin color and its In-vitro anti-oxidant capacity

Ultrasound (US) has been recognized as a non-thermal technology for accelerating blueberry wine aging for flavor development. However, influence of US on anthocyanin and color characteristics is uncertain. In this study, US was applied to new blueberry wine, and changes in color characteristics, anthocyanin content and anti-oxidant capacity were evaluated at early stage of aging period. Low-frequency power US resulted in an improvement in color characteristics and lower chromatic aberration as compared to untreated samples, specially at condition of 180 W, 20 min and 2 cycles. Furthermore, this contribution was attributed to unattenuated anthocyanins protected from US stress. Importantly, the structural polarity dependence was mediated by the impact of US on anthocyanins. Additionally, anti-oxidant activity of blueberry wine was not adversely affected under a moderate US condition. US treatment of blueberry wine was therefore considered to significantly enhance the color presentation, hinting at the possibility of promoting blueberry wine aging.

[The association between Cathepsin S and pulmonary function and CT phenotypes in patients with chronic obstructive pulmonary disease]

Objective: To explore the value of cathepsin S in the bronchoalveolar lavage fluid (BALF) of patients with chronic obstructive pulmonary disease (COPD) in the evaluation of pulmonary function and CT phenotypes. Method: From April 2014 to April 2017, 46 patients with stable COPD were enrolled, and 29 healthy volunteers served as the control group. The patients were divided into 4 subgroups: GOLD Ⅰ(n=12), GOLD Ⅱ(n=6), GOLD Ⅲ(n=14), GOLD Ⅳ(n=14). The levels of cathepsin S and IFN-γ in BALF were determined by enzyme-linked immunosorbent assay (ELISA). The percentage ratio of low attenuation area to total lung area (LAA%), two times the ratio of airway wall thickness to outer diameter(2T/D), and the ratio of wall area to total cross-sectional area (WA) were measured by HRCT. Results: There were significant differences in the levels of cathepsin S in BALF between the groups (F=6.639, P=0.000). BALF cathepsin S levels were as follows: GOLD Ⅳ grou P>GOLD Ⅲ grou P>GOLD Ⅱ grou P>GOLD group Ⅰ >healthy control group (P value were all<0.05); LAA grade 3>LAA grade 2>LAA grade 1>LAA grade 0 (P value were all<0.05). Correlation analysis showed that BALF cathepsin S levels were correlated negatively with FEV(1)/FVC, FEV(1)% predicted, and DLCO% (r value was -0.065、-0.576、-0.392, respectively, P value were all<0.05), and but positively with RV/TLC%, LAA%, 2T/D, WA and IFN-γ(r value was 0.695, 0.497, 0.142, 0.309, 0.148, respectively, P value were all<0.05). Conclusion: The levels of cathepsin S were associated with the degree of airflow limitation and emphysema phenotype in COPD.

High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200  GeV the positron fraction no longer exhibits an increase with energy.

First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV

A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250  GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

S100+ cells: a new neuro-immune cross-talkers in lymph organs

Up to now, the ‘hardwired’ neural pathway of the neuro-immune regulation is not fully understood. Here we reported a new neural pathway which links sympathetic nerves with immune cells of the lymphoid tissues. Our results demonstrated that nerve fibers derived from superior cervical ganglion directly targeted only S100⁺ cells in the cervical lymph nodes. Moreover, we found co-expression of neurotransmitters such as norepinephrine, vasoactive intestinal polypeptide and neuropeptide Y in the postganglionic sympathetic nerve endings that innervate S100⁺ cells. Our findings suggested that S100⁺ cells serve as a neuro-immune cross-talker in lymph organs that may play a significant role in transmitting signals of nervous cells to targeted immune cells. The new findings provide better understanding of the cross-talk mechanism between the nervous system and the immune system.

Multi-walled carbon nanotubes as a new counter electrode for dye-sensitized solar cells

Airbrushed multi-walled carbon nanotube (MWNT) networks were investigated as a new counter electrode for dye-sensitized TiO2 photoelectrochemical solar cells. The structural and physical properties of the MWNTs were studied by various techniques including SEM, TEM, Raman, optical absorption, and electrochemical impedance spectroscopy (EIS). The MWNTs exhibited catalytic activity for the reduction of triiodide in the electrolyte as studied by EIS measurements. The performance of the dye-sensitized solar cells was improved by using MWNTs as counter electrodes. This observation is explained by the significantly increased contact area between the MWNT counter electrode and the electrolyte which facilitates efficient charge transportation in the solar cell. We demonstrated that the MWNTs are suitable for replacing expensive Pt electrodes for fabricating high efficiency dye-sensitized solar cells. The process used in this study is also technically attractive for large scale and economic production.

The adhesion and proliferation of bone marrow-derived mesenchymal stem cells promoted by nanoparticle surface

This study's aim consists of evaluating the adhesion and proliferation of mesenchymal stem cells (MSCs) derived from rat bone marrow on nanoparticle Titanium (Ti) surface. Hence, passage 3 MSCs were, respectively, seeded on nanoparticle Ti and pure Ti surfaces and then cultured for 32 h. Cell morphology and viability were separately examined by scanning electron microscopy and 3-(4,5-dimethylthiazsol-2-yl)-2,5-diphenyltetrazolium bromide assay. Moreover, the mitotic rate of the attached MSCs was observed through immunocytochemistry. The real-time polymerase chain reaction was applied to determine the adhesion-associated messenger ribonucleic acid (mRNA), CD44 gene encoding variant isoform 6 (CD44 V6), and the integrinβ1 level. The results showed that MSCs performed better in faster extension on the nanoparticle Ti surface than on the pure Ti surface after culturing for 4 h, and were quicker in fusion patterns after 16 h. Furthermore, cell viability was significantly increased on the nanoparticle Ti surface compared to that of the pure Ti surface 16 h after initial seeding (p < 0.05), and the mitotic rate of attached MSCs on the nanoparticle Ti surface was higher than that on the pure Ti surface after 32 h (p < 0.05). More interestingly, the CD44 V6 and integrinβ1 mRNA in the nanoparticle Ti surface group expressed higher than that in the pure Ti surface group after 4 h (p < 0.05), and positive correlation between CD44 V6 and integrinβ1 was found through statistical analysis (correlation coefficient r (s) = 0.98, p < 0.05). Our study's result indicates that a nanoparticle Ti surface can significantly promote the adhesion and proliferation of MSCs, and also improve the bioactivity of Ti surface.

Development and expression of amyloid-β peptide 42 in retinal ganglion cells in rats

The previous studies have shown that amyloid-β peptide (Aβ) was mainly found in neurons of neurodegenerative diseases, such as Alzheimer's disease (AD) and glaucoma and little is known about its expression in normal nerve cells. The aim of the present study was to investigate the expression of amyloid-β peptide 42 (Aβ-42) in retinal ganglion cells of the postnatal rats. Rats were divided into seven experimental groups: 3, 6, 13, 15, 25, 60, and 90 days postnatal groups. Rats from 15 and 25 days postnatal groups were further divided into light-exposure and non light-exposure group. Cryosections or flat-mounted retinas of rat eyes were used for testing Aβ-42 by immunocytochemistry staining. Aβ-42 expression was not observed in rats within 13 days after birth, but was easily detectable in all groups of rats over 15 days after birth. In addition, the expression of Aβ-42 in retina was increasing as the rats got older, reached to highest level in 60 days after birth. Furthermore, the expression of Aβ-42 was not detected in rats kept under dark indicating that light is required for the expression of Aβ-42 in retina. This is the first report showing that normal retinal ganglion cells express Aβ-42, and that the expression of Aβ-42 in retinal ganglion cells requires the exposure to light. These data suggest that Aβ-42 may play a important role in vision development.

Vascular smooth muscle cell remodelling in elastase-induced aortic aneurysm

OBJECTIVE; ; The objective of this study was to identify developmental changes in vascular smooth muscle cells (VSMC) during aneurysm formation using an elastase-induced rabbit carotid artery aneurysm model.

METHODS

- Aneurysms were induced in carotid arteries of rabbits by exposure to elastase. Tissues from developing aneurysms were isolated at various time points for histological, immunohistochemical and RT-PCR analysis.

RESULTS

During aneurysm growth, the vascular media became thinner and elastic fibres became fragmented.The expression of smooth muscle marker SM22alpha and cytoskeleton proteins (SM alpha-actin, beta-tubulin and desmin) expression was decreased while platelet-derived growth factor (PDGF) was increased, which correlated with a remodelling ofVSMC from contractile to synthetic functions.

CONCLUSION

During the development of aneurysm, despite the induction of apoptosis, VSMC undergoes a remodelling from a contractile phenotype to a synthetic phenotype as a potential repair mechanism. Further studies may reveal the causative effects between these events.

Cell immobilization using PVA crosslinked with boric acid

A new cell immobilization technique is described in which polyvinyl alcohol is crosslinked with boric acid, with the addition of a small amount of calcium alginate. The presence of the calcium alginate improves the surface properties of the beads, preventing agglomeration. A pure culture of phenol-degrading Pseudomonas was immobilized in the PVA-alginate beads. Phenol was successfully degraded in a fluidized bed of the beads, indicating that cell viability was maintained following the immobilization procedure. The PVA-alginate beads proved to be very strong and durable, with no noticeable degradation of the beads after 2 weeks of continuous operation of the fluidized bed.

The association of clinical findings and exposure profiles with melamine associated nephrolithiasis

BACKGROUND

Little is known about the exposure profiles of melamine in children. We evaluated the association of clinical findings, exposure patterns and biomarkers with nephrolithiasis in children with potential exposure to melamine.

METHODS

A case-control study was conducted in children aged 0-16 years with potential exposure to contaminated dairy products. Cases were defined as nephrolithiasis detected by renal ultrasonography. On the basis of different brands of contaminated dairy products consumed, subjects were classified into high exposure, low exposure and control groups with estimated melamine exposure levels of higher than 2.5 ppm, 0.05-2.5 ppm and lower than detection limits <0.05 ppm. We measured urine melamine for those with nephrolithiasis and age-matched and gender-matched controls within the subset of the study population.

RESULTS

The duration of consumption of contaminated products was longer in children with nephrolithiasis in the high exposure group than in controls (median (IQR) 12.0 (3.3-24.0) vs 6.0 (4.0-7.0) months; p = 0.048). High melamine exposure levels were significantly associated with nephrolithiasis (OR 61.04 (95% CI 12.73 to 292.84)). The risk was found to increase with estimate melamine exposure levels (p for trend <0.001). Two among 10 affected subjects with nephrolithiasis showed elevated urine melamine levels. In comparison, levels of all 20 controls were lower than the detection limit.

CONCLUSIONS

The risk of melamine-associated nephrolithiasis was related to duration of consumption of contaminated products and estimated melamine exposure levels. Though urine melamine was not a sensitive test, it might serve as an exposure biomarker in melamine-associated nephrolithiasis.

[Establishing an organic model of SMC proliferation with cultured aorta of rats and exploring the underlying mechanism]

To study the mechanism of proliferous vascular disease as well as its prevention and treatment, an organic model was established with cultured aortas of rats, and the mechanism there-in invloved was probed. Immunostaining histology showed that smooth muscle cell (SMC) proliferation was observed in the aorta segments of rats, after their endothelia being injured and cultured in vitro with 20% fetal bovine serum. After being cultured for 5 days, various degrees of proliferation of SMC on cultured artery segments were observed by HE staining, and conspicuous plaques were developed after being cultured for 13 days. The proliferous SMC was also observed by Brdu labeling. RT-PCR examination showed that the mRNA expression of hypertension-related gene-1 (Hrg-1) and smooth muscle 22 alpha (SM22a) in the aortas decreased with the prolongation of culture time, and completely disappeared after being cultured for 13 days . But when cultured in vitro for ten days, the ET-1 content of supernatant and the proliferous SMC labeled by Brdu increased obviously and the expressions of Hrg-1 and SM22a decreased after the endothelium was destroyed. Compared with the injured endothelium groups, the proliferous SMC of injured endothelium plus BQ123 groups decreased visibly. The same significant differences between serum groups and serum-free groups were also observed. These results suggest that the culturing of rat aorta segments in vitro can induce the proliferation of SMC and the transform of phenotype from contractile type to synthetic type. The ET-1 and serum are the main factors in the proliferation of SMC and in the transform of phenotype. This organic model could serve as a good experimental platform for the researches into the mechanism of proliferous vascular disease as well as its prevention and treatment.

Chromium (VI) induced oxidative damage to DNA: increase of urinary 8-hydroxydeoxyguanosine concentrations (8-OHdG) among electroplating workers

AIMS

To investigate the concentration of urinary 8-hydroxydeoxyguanosine (8-OHdG) among electroplating workers in Taiwan.

METHODS

Fifty workers were selected from five chromium (Cr) electroplating plants in central Taiwan. The 20 control subjects were office workers with no previous exposure to Cr. Urinary 8-OHdG concentrations were determined using high performance liquid chromatography with electrochemical detection.

RESULTS

Urinary 8-OHdG concentrations among Cr workers (1149.5 pmol/kg/day) were higher than those in the control group (730.2 pmol/kg/day). There was a positive correlation between urinary 8-OHdG concentrations and urinary Cr concentration (r = 0.447, p < 0.01), and urinary 8-OHdG correlated positively with airborne Cr concentration (r = 0.285). Using multiple regression analysis, the factors that affected urinary 8-OHdG concentrations were alcohol, the common cold, and high urinary Cr concentration. There was a high correlation of urinary 8-OHdG with both smoking and drinking, but multiple regression analysis showed that smoking was not a significant factor. Age and gender were also non-significant factors.

CONCLUSION

8-OHdG, which is an indicator of oxidative DNA damage, was a sensitive biomarker for Cr exposure.

Induction of cellular toxicity in cultured porcine corneal keratocytes by endothelin-1

The effect of endothelin-1 (ET-1) on corneal cells is not well understood. We investigated the biochemical changes of cultured porcine corneal keratocytes under exposure to ET-1. The results indicate that ET-1 has remarkable effects to inhibit corneal keratocytes on 3H-thymidine, 3H-leucine, 3H-uridine uptakes and cellular migration. It is in a dose-dependent manner at concentrations ranging from 10(-7) M to 10(-9) M. The 50% inhibitory dose (ID50) for ET-1, as measured by 3H-thymidine uptake, 3H-uridine uptake and 3H-leucine uptake, were 10(-7) M, 10(-0.52) M and 10(-11.8) M, respectively. The dead and living cells were estimated with MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay that was converted tetrazolium dye of living cells only into insoluble purple formazan crystals within mitochondria. In the presence of ET-1, the cellular MTT values were also decreased. The ID50 for ET-1 with cell migration assay and MTT assay were measured at 10(-7.86) M and 10(-5.1) M. Endothelin-1 (10(-6) M) promptly changed cellular morphology and attenuated adhesion observed with laser scanning cytometer. Endothelin-1-induced characteristic apoptosis cells were observed using a TUNEL assay that detected fragmented DNA of apoptosis. Western blot assay revealed that endothelin-1 induced proteolysis and decreased in fibronectin protein. These findings indicate that endothelin-1 may lead keratocytes to death resulting from induction of apoptosis and functional loss.

Tentative surgical repair of leaking filtering bleb with amniotic membrane transplantation--a case report

To repair a traumatic leaking cystic bleb in a 50-year-old male patient who had received multiple glaucoma filtering surgeries with the application of mitomycin-C, an amniotic membrane covered over the leaking bleb and sutured it to the adjacent conjunctiva with 10-0 nylon was done. The anterior chamber gradually formed after the amniotic membrane transplantation (AMT) and intraocular pressure returned to the level before trauma. Three weeks after the operation, the amniotic membrane was removed. No more leakage from the bleb was observed during four months follow-up. However, another bleb revision surgery was performed later to repair recurrent bleb leakage. Although conjunctival advancement or free conjunctival autograft have been reported to repair leaking bleb successfully, the simple primary method of using AMT is still encouraged in repair of a ruptured bleb with tentative maintenance of adequate filtration.

Toxic effects of mitomycin-C on cultured ciliary process cells and trabecular meshwork cells

Mitomycin-C has recently become an adjunct medication for inhibition of fibroblast proliferation in glaucoma filtering procedures. Prolonged postoperative ocular hypotony has been a frequent complication of trabeculectomy with mitomycin-C. In order to characterize the hypotony mechanism, we compared the toxic effects of mitomycin-C on cultured rabbit ciliary process cells and trabecular meshwork cells. The results indicate that mitomycin-C has a more marked effect on ciliary process cells on 3H-thymidine uptake than on trabecular meshwork cells at concentrations ranging from 10(-1) to 10(-5) mg/ml after 3-, 5- and 60-min treatment, respectively. The living cells after mitomycin-C treatment were estimated with MTT assay that was converted tetrazolium dye of living cells only into insoluble purple formazan crystals within mitochondria. In the presence of mitomycin-C for 3, 5, and 60 min, the cellular MTT values in ciliary process cells were more decreased than in trabecular meshwork cells. Depolarization of the trabecular meshwork cells with 50 mM KCl led to an increase in intracellular calcium concentration, whereas application of mitomycin-C at 10(-3) mg/ml resulted in decrease of KCl-induced intracellular calcium increase. Mitomycin-C (10(-3) mg/ml) decreased cAMP concentration in ciliary process cells following 3- and 5-min treatment; however, it did not significantly affect the cellular cAMP concentration after only a 1-min exposure. Mitomycin-induced marked ladder pattern of DNA fragmentation was observed in ciliary process tissues after treatment with 10(-1) mg/ml of mitomycin-C for 3 and 5 min. However, the DNA pattern in trabecular meshwork tissues was not obviously affected by mitomycin-C. These findings from our results indicate that mitomycin-induced ocular hypotony may result from damage to both ciliary process and trabecular meshwork tissues.

Endothelin-induced changes of secondary messengers in cultured corneal endothelial cells

The effect of endothelins on corneal endothelial cells is not well understood. We have investigated the effects of endothelin-1 (ET-1), endothelin-2 (ET-2) and endothelin-3 (ET-3) on bovine corneal endothelial cellular proliferation and the secondary messenger changes in cells in the presence of ET-1. It was found that the 3H-thymidine uptake was enhanced by ET-1 significantly, whereas ET-2 and ET-3 had no effect. ET-1 remarkably affects the increase of corneal endothelial cells on 3H-thymidine, 3H-leucine, and 3H-uridine uptakes in a dose-dependent manner. The 50% effective concentrations (EC50) for ET-1, as measured by 3H-thymidine uptake, 3H-uridine uptake, and 3H-leucine uptake were 10(-8.78) M, 10(-8.53) M and 10(-8.04) M, respectively. It was found that endothelin-1 increased intracellular calcium concentration by using the method of preloading with Fura-2-AM and assaying with spectrophotometry. The cellular IP1, IP2, and IP3 were also stimulated in the presence of ET-1. Moreover, ET-1 enhanced the basal cellular cAMP and cGMP concentrations in corneal endothelial cells in a dose-dependent manner. Immunofluorescent staining revealed that ET-1 increased the fibronectin protein concentration and changed protein distribution in corneal endothelial cells. These findings indicate that endothelin-1 increases in cell proliferation and biological changes may be involved in changing intracellular calcium mobility, increasing intracellular phosphoinositides, enhancing intracellular cGMP and cAMP accumulation, and fibronectin protein synthesis.

Herniated blastomere following chemically assisted hatching may result in monozygotic twins

OBJECTIVE

To explore a possible mechanism of the increasing incidence of monozygotic twins following assisted hatching of human embryos.

DESIGN

Case report.

SETTING

Clinical research center in a medical school teaching hospital.

PATIENT

A 37-year-old infertile woman with repeated IVF failures.

INTERVENTION(S)

Assisted hatching of the day 3 embryos using acidic Tyrode's solution.

MAIN OUTCOME MEASURE(S)

The morphology of the zona-drilled embryos and the pregnancy outcome.

RESULT(S)

After assisted hatching, a herniated blastomere through an oversized opening in the zona pellucida was found in one embryo. The transfer of two zona-drilled embryos resulted in a triplet pregnancy.

CONCLUSION(S)

Large openings in the zona pellucida following chemically assisted hatching may cause premature hatching of the blastomeres and may be implicated in the occurrence of monozygotic twins.

Effects of drugs on cellular proliferation in cultured iris pigment epithelial cells and retinal pigment epithelial cells

In this study, iris and retinal pigment epithelial cells were cultured from porcine and various drugs including methionine-enkephalin, isoproterenol, dibutyryl cAMP, endothelin-1, dexamethasone and phorbol 12-myristate 13-acetate (PMA) were used to investigate their effects on both cellular proliferation in cultured porcine iris and retinal pigment epithelial cells. Cellular proliferation was estimated with 3H-thymidine uptake. It is indicated that both pigment epithelial cells possess epithelial-like morphology and abundant pigment granules in cells obviously. Following the iris pigment epithelial cells being treated with endothelin-1, the 3H-thymidine uptake in the cells was increased to 126% as compared with the control. However, the cellular proliferation was decreased to 83% when the cells were treated with isoproterenol. In the case of methionine-enkephalin, dibutyryl cAMP, dexamethasone and phorbol 12-myristate 13-acetate (PMA), the thymidine uptake in the iris pigment epithelial cells was not affected by above drugs. In the retinal pigment epithelial cells, the 3H-thymidine uptakes were increased to 145% and 146% when the cells were incubated with methionine-enkephalin, and isoproterenol, respectively. In the presence of dibutyryl cAMP, dexamethasone and phorbol ester (PMA), the cellular proliferation was inhibited to 83%, 73% and 85% respectively. However, endothelin-1 did not affect the cellular proliferation in retinal pigment epithelial cells. These results show that the morphological shapes of iris pigment epithelial cells are similar to retinal pigment epithelial cells. However, the cellular proliferation in both cells may be regulated by distinct mechanisms.

Biomarkers of exposure and effect as indicators of potential carcinogenic risk arising from in vivo metabolism of ethylene to ethylene oxide

The purposes of the present study were: (i) to investigate the potential use of several biomarkers as quantitative indicators of the in vivo conversion of ethylene (ET) to ethylene oxide (EO); (ii) to produce molecular dosimetry data that might improve assessment of human risk from exogenous ET exposures. Groups (n = 7/group) of male F344 rats and B6C3F1 mice were exposed by inhalation to 0 and 3000 p. p.m. ET for 1, 2 or 4 weeks (6 h/day, 5 days/week) or to 0, 40, 1000 and 3000 p.p.m. ET for 4 weeks. N:-(2-hydroxyethyl)valine (HEV), N:7-(2-hydroxyethyl) guanine (N7-HEG) and HPRT: mutant frequencies were assessed as potential biomarkers for determining the molecular dose of EO resulting from exogenous ET exposures of rats and mice, compared with background biomarker values. N7-HEG was quantified by gas chromatography coupled with high resolution mass spectrometry (GC-HRMS), HEV was determined by Edman degradation and GC-HRMS and HPRT: mutant frequencies were measured by the T cell cloning assay. N7-HEG accumulated in DNA with repeated exposure of rodents to 3000 p.p.m. ET, reaching steady-state concentrations around 1 week of exposure in most tissues evaluated (brain, liver, lung and spleen). The dose-response curves for N7-HEG and HEV were supralinear in exposed rats and mice, indicating that metabolic activation of ET was saturated at exposures >/=1000 p.p.m. ET. Exposures of mice and rats to 200 p.p.m. EO for 4 weeks (as positive treatment controls) led to significant increases in HPRT: mutant frequencies over background in splenic T cells from exposed rats and mice, however, no significant mutagenic response was observed in the HPRT: gene of ET-exposed animals. Comparisons between the biomarker data for both unexposed and ET-exposed animals, the dose-response curves for the same biomarkers in EO-exposed rats and mice and the results of the rodent carcinogenicity studies of ET and EO suggest that too little EO arises from exogenous ET exposure to produce a significant mutagenic response or a carcinogenic response under standard bioassay conditions.

Change of calcium and cAMP concentration by adrenoceptor agents in cultured porcine corneal endothelial cells

It has been reported that beta-adrenergic receptors are localized in the corneal endothelial cells. In this study, the change of cellular signal transduction, such as intracellular calcium and cAMP, was determined with pure adrenergic agonists and commercial antiglaucoma adrenergic agents. The intracellular calcium of cultured porcine corneal endothelial cells was inhibited by 10 microM isoproterenol and norepinephrine, but enhanced by propranolol and 50 mM KCl. In the case of phenylephrine, calcium mobility did not alter significantly. Verapamil, at 10 microM, decreased intracellular calcium concentration. In the presence of isoproterenol, cellular cAMP concentration increased from 28.8 pmole/mg protein (1 microM) to 42.2 pmole/mg protein (100 microM) compared with control of 6.07 pmole/mg protein. Incubation with commercial adrenergic eye drops, such as betaxolol, caused the cAMP concentration to increase from 21.6 pmole/mg protein (0.0005%) to 39.1 pmole/mg protein (0.05%). Adding commercial levobunolol and timolol into cells caused cellular cAMP to increase from 14.3 pmole/mg protein (0.0005%) to 840.5 pmole/mg protein (0.05%) and from 115.2 pmole/mg protein (0.00025%) to 931.0 pmole/mg protein (0.025%), respectively. However, the preservative, benzalkonium chloride, increased cellular cAMP from 15.4 pmole/mg protein (0.00001 mg/ml) to 1087.4 pmole/mg protein (0.01 mg/ml). It is concluded that the intracellular calcium of corneal endothelium decreases when the cellular adrenergic receptor is activated by agonists. Benzalkonium chloride, due to its preservative in commercial antiglaucoma agents which increases cellular cAMP, may alter corneal endothelial physiology through long-term use.

Corticosteroid dynamics in the nonpregnant, pregnant, and postpartum spontaneously hypertensive rat

Factors responsible for hypertension in the spontaneously hypertensive rat (SHR) remain under investigation. As in human pregnancy complicated by essential chronic hypertension, the hypertension of the pregnant SHR subsides and returns postpartum. Because corticosteroid excess can cause hypertension, we examined several aspects of adrenocortical activity as potentially affecting the reported blood pressure profiles of nonpregnant, term pregnant, and postpartum SHR, using normotensive Wistar-Kyoto (WKY) rats as controls. We found that corticosterone levels were comparable in nonpregnant SHR and WKY rats, and unaffected by pregnancy. No differences were detected postpartum. Although pregnancy was accompanied by significant increases in plasma aldosterone levels, no interbreed differences were observed, which remained the case postpartum. Single adrenal cell secretion of aldosterone and corticosterone, as detected by reverse hemolytic plaque assay, yielded similar results in the pregnant and postpartum rat. Hormone responses to dietary manipulations in the nonpregnant and pregnant SHR and WKY suggest an important role for ACTH, and a lesser one for AII in the regulation of corticosteroids. In situ hybridization histochemistry, using a probe that detects both P450c11beta and P450c11AS mRNA, revealed comparable message density and zonal distribution in adrenals from pregnant and nonpregnant SHR and WKY rats. Breed- and pregnancy-dependent differences in adrenal expression of P450scc, P450c11beta, and P450c11AS were noted. In summary, our findings suggest that although some discrepancies exist in the aspects of adrenocortical activity examined, they are unlikely to be etiologic in the blood pressure profile observed in nonpregnant, pregnant, and postpartum SHR.

1,3-butadiene: cancer, mutations, and adducts. Part V: Hemoglobin adducts as biomarkers of 1,3-butadiene exposure and metabolism

1,3-Butadiene (BD) is an important chemical used largely in the manufacture of synthetic rubber and thermoplastic resins. In addition, it has been identified in cigarette smoke, automobile exhaust, and gasoline vapor. The objective of this research was to develop highly sensitive and specific assays for the detection and quantitation of hemoglobin adducts of three BD metabolites: 1,2-epoxy-3-butene (BDO), 1,2,3,4-diepoxybutane (BDO2), and 1,2-dihydroxy-3,4-epoxybutane (BDO-diol). We have successfully developed an assay for both N-(2-hydroxy-3-butenyl)valine (HBVal) and N-(2,3,4-trihydroxybutyl)valine (THBVal) in hemoglobin. The six adducts measured were the two diastereomers (isomers I and II) of HBVal and the four diastereomers of THBVal (isomers I through IV, which were eluted as three peaks, 1, 2, and 3). HBVal and THBVal were measured in control and exposed B6C3F1 mice and Sprague-Dawley rats (1,000 ppm BD for 13 weeks at 6 hours/day, 5 days/week). In a second set of animal exposures, total THBVal was determined in B6C3F1 female mice (n = 5) exposed to 1,250 ppm BD for 1, 5, or 10 days (6 hours/day, 5 days/week). THBVal adducts were also monitored in occupationally exposed Chinese workers and nonoccupationally exposed U.S. laboratory workers. This study utilized the modified Edman degradation method of Törnqvist and colleagues (1986). Briefly, the samples were subjected to Edman degradation, Centricon-30 ultrafiltration, washing on C18 columns, and acetylation for isomers of THBVal only, followed by gas chromatography-mass spectrometry (GC-MS) quantitation. For the HBVal assay, an authentic internal standard globin alkylated with [2H6]BDO was used; for the THBVal assay, a synthesized external standard, THB[13C5]Val, was used after Edman degradation. The mean +/- SD amounts of total HBVal measured in exposed mice (in pmol/g globin) were 16,560 +/- 3,910 for female mice (n = 4) and 12,400 +/- 2,030 for male mice (n = 5). The corresponding values for rats were 8,690 +/- 930 for female rats (n = 5) and 5,480 +/- 2,880 for male rats (n = 3). The total amount of THBVal (eluted peaks 1, 2, and 3) in male mice (n = 5) was 78,900 +/- 13,700; and in females (n = 2) was 56,100 +/- 100. In male rats (n = 3), the detected value was 9,650 +/- 1,620 and in females (n = 3) the value was 21,600 +/- 6,780. In control male mice (n = 4), the total level of THBVal isomers was approximately 27 pmol/g globin. In a control male rat, total THBVal was approximately 15 pmol/g globin. In the time course study, the amount of THBVal adducts increased linearly with exposure, resulting in values of 4,200 +/- 830, 19,760 +/- 1,780, and 35,940 +/- 3,460 pmol/g globin following 1, 5, or 10 days of exposure to 1,250 ppm BD, respectively. Detection of HBVal in human samples was difficult due to low concentrations of adducts and a high background in the chromatograms. In a pooled sample from 4 individuals, we performed multiple separations with high-pressure liquid chromatography (HPLC) of the derivatized adducts and detected 4.6 pmol/g globin (that is, 2.7 and 1.9 pmol/g globin for isomers I and II, respectively). We measured the amounts of THBVal in both nonoccupationally exposed U.S. laboratory workers and occupationally exposed workers from a polybutadiene plant in China. The mean total amount of THBVal among the U.S. laboratory workers was 36 +/- 23 pmol/g globin for nonsmokers (n = 7) and 40 +/- 9 for smokers (n = 4), compared with a mean total amount of 39 +/- 13 pmol/g globin in a control set of Chinese workers (n = 25). These control values are overestimations of the true values because the amounts of THBVal in globin samples from other unexposed individuals (15 of 51) were below our limit of detection. BD-exposed Chinese workers had a total amount of 88 +/- 59 pmol/g globin THBVal. The difference between smokers and nonsmokers was not significant, whereas the difference between control and exposed Chinese workers was highly significant (p < 0.001).

Adrenocortical activity in fetal SHR and WKY rats

There is increasing evidence that the intrauterine milieu and corticosteroid exposure play a role in the etiology of hypertension. We examined adrenocortical gene expression and circulating corticosteroids in the d 21 fetal spontaneously hypertensive rat (SHR) and its normotensive genetic control, the Wistar-Kyoto (WKY) rat. By RNase protection assays, we found no differences in the relative abundances of mRNAs for P450scc and P450c11beta, and barely detectable P450c11AS mRNA in the adrenals of fetal SHR and WKY rats. P450c11B3 RNA was undetectable by reverse transcription polymerase chain reaction in both SHR and WKY fetuses. The zonal expression of P450c11 mRNA was comparable in SHR and WKY fetuses by in situ hybridization histochemistry. There were no significant differences in peripheral levels of aldosterone and corticosterone by radioimmunoassay in fetal SHR and WKY rats. Based upon the absence of distinct differences in the aspects of adrenocortical activity examined, it is unlikely that they are integral in the programming of hypertension in this model.

Toxic effects of mitomycin-C on cultured corneal keratocytes and endothelial cells

Improper use of mitomycin-C in ocular medication may result in damage to corneal cells. In this study, the toxic effects of mitomycin-C on cultured porcine keratocytes and endothelial cells were estimated by MTT, 3H-thymidine uptake and cellular counting assay methods. It was found that mitomycin-C caused a dose-dependent toxic effect to keratocytes and endothelial cells. Both cells were treated with mitomycin-C at the concentration ranging from 100, 10, 1, 0.1 to 0.01 microg/ml for 3 min, 5 min or 100 min. The 50% inhibitory dose (ID50) of mitomycin-C to keratocytes and endothelial cells as measured by MTT assay was 0.40, 0.18, 0.16 mg/ml and 0.27, 0.15, 0.14 mg/ml, respectively, after 3, 5 and 100 minutes drug treatment. The ID50 for keratocytes and endothelial cells as measured by 3H-thymidine uptake immediately, 1 day and 7 days after 100 minutes mitomycin-C treatment was 0.3, 0.0002, 143.2 microg/ml and 45.1, 101.1, 450.2 microg/ml, respectively. The ID50 for keratocytes and endothelial cells as measured by cellular counting 1 day and 7 days after mitomycin-C treatment was 232.5, 109.7 microg/ml and 239.9, 367.5 microg/ml, respectively. It is concluded that mitomycin-C is more toxic to cellular proliferation in cultured corneal keratocytes than in endothelial cells.

Molecular dosimetry of endogenous and ethylene oxide-induced N7-(2-hydroxyethyl) guanine formation in tissues of rodents

The formation of N7-(2-hydroxyethyl)guanine (7-HEG) in DNA was investigated previously in target and non-target tissues of F-344 rats and B6C3F1 mice exposed to >/=ISOdia>/=10 p.p.m. concentrations of ethylene oxide (EO) using fluorescence-linked high-performance liquid chromatography [V.E. Walker et al. (1992) Cancer Res., 52, 4238-4334]. In order to study the dose-responses for 7-HEG at lower exposures, a highly sensitive and specific gas chromatography coupled with high-resolution mass spectrometry (GC-HRMS) assay was developed. DNA was extracted from liver, brain, lung and spleen of B6C3F1 mice and F-344 rats exposed to 0, 3, 10, 33 or 100 p.p.m. EO for 4 weeks (6 h/day, 5 days/week). Analysis of DNA from control rodents showed that endogenous 7-HEG varied from 0.2 +/- 0.1 to 0.3 +/- 0.2 pmol/micromol guanine in tissues of rats and mice. 7-HEG exhibited tissue- and species-specific dose-response relationships in EO-exposed animals. Linear dose-response relationships were evident in mouse liver, brain and spleen at exposures between 3 and 100 p.p.m. Mouse lung exhibited a slightly sublinear response between 33 and 100 p.p.m. EO. The relationships were linear in liver and spleen of rats between 3 and 100 p.p.m. EO, but were slightly sublinear in brain and lung between 33 and 100 p.p.m. EO. The number of 7-HEG adducts present in rats exposed to 3 p.p.m. EO was 5.3-12.5 times higher than endogenous 7-HEG in unexposed controls. In contrast, mice exposed to 3 p.p.m. EO only had 1.3- to 2.5-fold greater numbers of 7-HEG adducts. The factors driving the exposure-response relationships are also likely to affect carcinogenic and mutagenic responses of rodents to EO. Likewise, a better understanding of the relationships between 7-HEG derived from low exposures to EO and endogenously formed 7-HEG may be important for the accurate extrapolation of risk to humans.

A gas chromatography/electron capture/negative chemical ionization high-resolution mass spectrometry method for analysis of endogenous and exogenous N7-(2-hydroxyethyl)guanine in rodents and its potential for human biological monitoring

A gas chromatography/electron capture/negative chemical ionization high-resolution mass spectrometry (GC/EC/NCI-HRMS) method was developed for quantitating N7-(2-hydroxyethyl)guanine (N7-HEG) with excellent sensitivity and specificity. [4,5,6,8-(13)C(4)]-N7-HEG was synthesized, characterized, and quantitated using HPLC/electrospray ionization mass spectrometry (HPLC/ESI-MS) so it could serve as an internal standard. After being converted to its corresponding xanthine and derivatized with pentafluorobenzyl (PFB) bromide twice, the PFB derivative of N7-HEG was characterized using GC/EC/NCI-HRMS carried out at full scan mode. The most abundant fragment was at m/z 555, with a molecular formula of C(21)H(9)N(4)O(3)F(10), resulting from the loss of one PFB group. By monitoring m/z 555.0515 (analyte) and m/z 559.0649 (internal standard), this assay demonstrated a linear relationship over a range of 1 fmol to 1 pmol of N7-HEG versus 20 fmol of [(13)C(4)]-N7-HEG on column. The limit of detection (LOD) for the complete assay was 600 amol (S/N = 5) injected on column. The variation of this assay was within 15% from 1 to 20 fmol of N7-HEG versus 2 fmol of [(13)C(4)]-N7-HEG with four replications for each calibration standard. Two hundred to three hundred micrograms of spleen DNA of control rats and mice and 100 microg of spleen DNA of rats and mice exposed to 3000 ppm ethylene for 6 h/day for 5 days were analyzed using GC/EC/NCI-HRMS. The amounts of N7-HEG varied from 0.2 to 0.3 pmol/micromol of guanine in tissues of control rats. Ethylene-exposed animals had 5-15-fold higher N7-HEG levels than controls. This assay was able to quantitate N7-HEG in 25-30 microg of DNA from human lymphocytes with excellent specificity. This was due in part to human tissues having 10-15-fold higher amounts of endogenous N7-HEG than rodents. These results show that this GC/EC/NCI-HRMS method is highly sensitive and specific and can be used in biological monitoring and molecular dosimetry and molecular epidemiology studies.

Adrenocortical imprint in the fetus of a diabetic gestation

Offspring of diabetics are at increased risk for diabetes as adults. As corticosteroids are intimately involved in glucose homeostasis, we investigated aspects of corticosteroid activity in the late gestation fetuses of control, moderately diabetic and insulin-controlled streptozotocin-induced diabetic rats. We found that moderate maternal diabetes had no effect upon litter size or fetal body weight. Uncontrolled maternal diabetes was accompanied by fetal hyperglycemia, hyperinsulinemia and elevated aldosterone. Maternal insulin treatment normalized fetal glucose and aldosterone; fetal insulin and corticosterone levels increased. Maternal diabetes had no effect upon fetal adrenal expression of P450scc mRNA; the abundance of P450c11beta mRNA increased, and returned to that of the control gestation upon insulin treatment. P450c11AS mRNA was barely detectable, and decreased in the fetuses of insulin-treated diabetics. P450c11B3 mRNA was undetectable in all fetal groups. Our results implicate aspects of maternal diabetes in the expression of a fetal adrenocortical imprint, manifested as a greater abundance of P450c11beta mRNA. Although not accompanied by elevated corticosterone in the fetus, this imprint could ultimately allow for greater potential corticosterone production in response to typical stimuli, and thus contribute to the tendency towards glucose dysregulation in these offspring of diabetic gestations.

Adrenocortical activity in the newborn spontaneously hypertensive rat

Blood pressure is reportedly elevated in the spontaneously hypertensive rat (SHR) neonate, the etiology of which remains unclear. Aberrations in the hypothalamic-pituitary-adrenal axis have been implicated, as it is well accepted that excess corticosteroids are associated with hypertension. We examined aspects of adrenocortical activity in the neonatal SHR 1 to 21 days old and its normotensive genetic control, the Wistar-Kyoto rat (WKY). We found a fourfold greater abundance of P450scc mRNA in adrenals of SHR versus WKY day 1 neonates, and increasing but comparable abundance of adrenal P450c11B mRNA on neonatal days 1 to 21. The pattern of P450c11AS mRNA expression was distinctly different in the adrenals of SHR and WKY neonates; the relative abundance of this mRNA in SHR increased 15-fold over the 21-day period examined, whereas that in WKY remained fairly stable. RT-PCR for the presence/abundance of adrenal P450c11B3 mRNA showed absence in day 1 SHR and WKY, comparable abundances on neonatal days 7 and 14, and a distinctly greater abundance in the day 21 SHR adrenals. Peripheral corticosterone levels were threefold greater in the day 1 SHR neonate; aldosterone levels were elevated in both the SHR and WKY day 1 neonate. Thereafter, corticosterone and aldosterone levels were comparable on days 7, 14, and 21, although the anticipated depression in circulating corticosterone levels typical of the stress hyporesponsive period was noted in both SHR and WKY neonates. Although patterns of adrenocortical activity differ in the newborn SHR and WKY rat, our findings do not support an etiologic role for corticosteroids in the reported hypertension of the SHR. However, observed differences in corticosteroid profiles may augment or have a permissive effect upon the etiologic factor(s).

Intraocular use of fluconazole in the management of ocular fungal infection

In this study, we investigate the efficacy and safety of intraocular use of fluconazole in the treatment of ocular fungal infection. Ten patients with intraocular fungal infections were examined. Among these patients, eight were infected with keratomycosis with intraocular spreading, one had postoperative fungal endophthalmitis after cataract operation with an intraocular lens implant, and another suffered from endogenous fungal endophthalmitis. In addition to the conventional local application with or without systemic administration of antifungal drugs, all ten patients were treated with intraocular administration of 5-10 micrograms/ml of fluconazole. The ocular fungal infections resolved in nine patients without obvious side effect. One failed in the antifungal treatment with loss of vision. In our experience, the results revealed that fluconazole is a safe and effective antifungal agent that can be administered intraocularly. We suggest that intraocular administration of this drug could be considered as an alternative or additional choice for the treatment of severe ocular fungal infections.

An automated fluorescent PCR method for detection of shiga toxin-producing Escherichia coli in foods

An automated fluorescence-based PCR system (a model AG-9600 AmpliSensor analyzer) was investigated to determine whether it could detect Shiga toxin-producing Escherichia coli (STEC). The AmpliSensor PCR assay involves amplification-mediated disruption of a fluorogenic DNA signal duplex (AmpliSensor) that is homologous to conserved target sequences in a 323-bp amplified fragment of Shiga toxin genes stx1, stx2, and stxe. Using the Amplisensor assay, we detected 113 strains of STEC belonging to 50 different serotypes, while 18 strains of non-Shiga-toxin-producing E. coli and 68 strains of other bacteria were not detected. The detection limits of the assay were less than 1 to 5 CFU per PCR mixture when pure cultures of five reference strains were used and 3 CFU per 25 g of food when spiked ground beef samples that were preenriched overnight were used. The performance of the assay was also evaluated by using 53 naturally contaminated meat samples and 48 raw milk samples. Thirty-two STEC-positive samples that were confirmed to be positive by the culture assay were found to be positive when the AmpliSensor assay was used. Nine samples that were found to be positive when the PCR assay was used were culture negative. The system described here is an automated PCR-based system that can be used for detection of all serotypes of STEC in food or clinical samples.

Genomic analysis reveals chromosomal variation in natural populations of the uncultured psychrophilic archaeon Cenarchaeum symbiosum

Molecular phylogenetic surveys have recently revealed an ecologically widespread crenarchaeal group that inhabits cold and temperate terrestrial and marine environments. To date these organisms have resisted isolation in pure culture, and so their phenotypic and genotypic characteristics remain largely unknown. To characterize these archaea, and to extend methodological approaches for characterizing uncultivated microorganisms, we initiated genomic analyses of the nonthermophilic crenarchaeote Cenarchaeum symbiosum found living in association with a marine sponge, Axinella mexicana. Complex DNA libraries derived from the host-symbiont population yielded several large clones containing the ribosomal operon from C. symbiosum. Unexpectedly, cloning and sequence analysis revealed the presence of two closely related variants that were consistently found in the majority of host individuals analyzed. Homologous regions from the two variants were sequenced and compared in detail. The variants exhibit >99.2% sequence identity in both small- and large-subunit rRNA genes and they contain homologous protein-encoding genes in identical order and orientation over a 28-kbp overlapping region. Our study not only indicates the potential for characterizing uncultivated prokaryotes by genome sequencing but also identifies the primary complication inherent in the approach: the widespread genomic microheterogeneity in naturally occurring prokaryotic populations.

Dexon and nylon-sutured wound reaction in conjunctival flap after trabeculectomy combined with or without topical application of mitomycin-C

In this study, rabbits were used to evaluate the sutured wound reaction with Dexon or nylon in the conjunctival flap 1, 4, 7, 14 and 28 days after trabeculectomy surgery with or without the use of mitomycin-C. Four major treated groups were used to compare their wound healing reaction; group 1--nylon-suture and non-mitomycin treatment; group 2--nylon-suture and mitomycin treatment; group 3--Dexon-suture and non-mitomycin treatment; group 4--Dexon-suture and mitomycin treatment. One day after surgery, the number of polymorphs was the greatest most in the nylon-sutured and non-mitomycin treated tissues (86 +/- 2). Four days after surgery, the number of polymorphs was the greatest most in Dexon-sutured and non-mitomycin treated tissues (109 +/- 87). The number of fibroblasts was the greatest most in nylon-sutured and non-mitomycin treated tissues (111 +/- 23). Seven days after surgery, the number of polymorphs was the greatest most in Dexon-sutured and mitomycin treated tissues (32 +/- 12). The number of fibroblasts was the greatest most in nylon-sutured and non-mitomycin treated tissues (126 +/- 15). Fourteen days after surgery, the number of fibroblasts was the greatest most in Dexon-sutured and non-mitomycin tissues (43 +/- 10). The number of goblet cells was the greatest most in nylon-sutured and non-mitomycin treated tissues (4 +/- 2). Twenty-eight days after surgery, the number of fibroblasts was the greatest most in Dexon-sutured and mitomycin treated tissues (40 +/- 15). The number of goblet cells was the greatest most in nylon-sutured and non-mitomycin treated tissues (4 +/- 2). Our conclusions are as follows: 1). The concentration of mitomycin in conjunctival wound edge should be maintained at as low a level as possible because the mitomycin will delay the wound healing process; 2). Nylon material is better than Dexon for conjunctival wound suture because nylon could induce a great quantity of fibroblasts before Dexon did.

Calcium-induced changes on crystallins in organ-cultured porcine lens

In this study, intact porcine lenses were cultured in vitro for 7 days supplemented with commercial balanced salt solution (BSS) which is usually used as an irrigation solution during intraocular surgery, and the lenses were maintained under various culture conditions, e.g. temperature and CO2 concentration. The intact porcine lenses after 7 days culture were analyzed with optical density scanner, gel permeation chromatography on TSK HM-55 column and SDS-PAGE (polyacrylamide gel electrophoresis). It was found that lenses exhibited the least opacity when lenses were cultured with Ca(+2)-free BSS buffer, CO2-free incubator and maintained at a temperature of 25 degrees C. After the lenses were cultured with Ca(+2)-free BSS or BSS medium, the composition of crystallins in lenses was separated with TSK HM-55 column. It was indicated that the percentage of high molecular weight (HMW) protein and (alpha-crystallin increased, and gamma-crystallin decreased in lenses incubated with BSS medium compared with lenses incubated with Ca(+2)-free BSS medium. Following an increase in the concentration of calcium in the medium from 4.3 mM, 20 mM, 50 mM, 100 mM to 200 mM, the opacity of the lens was measured with a densitometer. The changed percentage of various crystallins was similar to lenses with BSS media that increased in HMW protein and alpha-crystallin, decreasing in gamma-crystallin. In the case of lens protein pattern, the crystallin washed from TSK HM-55 gel was separated with SDS-PAGE (polyacrylamide gel electrophoresis). It was indicated that some of proteins disappeared when lenses were incubated with various concentrations of calcium. The vanished pH proteins were 20.5 kDa at 50 mM calcium, 20.5 kDa and 21 kDa at 100 mM, 20.5 kDa, 21 kDa, 22 kDa and 23 kDa at 200 mM which were compared with the protein bands in the presence of 20 mM calcium in BSS medium. This study indicates that the commercial balanced salt solution (BSS) which is usually used as an irrigating solution during intraocular operations may increase the risk for lens opacity because of the calcium contained in the solution.

Ocular hypotensive and vasodilative effects of two beta-adrenergic blockers with intrinsic sympathomimetic activity

PURPOSE

The ocular hypotensive and vasodilative effects of vaninolol and eugenolol, two beta-adrenergic blockers with intrinsic sympathomimetic activity, were tested in rabbits and their pharmacologic mechanisms were also studied in vitro.

METHODS

Intraocular pressure was measured in ocular hypertonic rabbits which were induced by infusing 20% NaCl or 5% glucose solution. The rabbit's ocular blood flow was determined using the colored microsphere technique. The concentrations of cAMP were evaluated in porcine ciliary body and cultured A7r5 smooth muscle cells by radioimmunoassay. Ca+2 concentration was measured in A7r5 cells by spectrofluorometry after loading cells with Fura-2-AM.

RESULTS

It was found that 0.5% eugenolol and vaninolol could suppress the intraocular pressure in glucose-induced ocular hypertensive rabbits and delay the intraocular pressure recovery in NaCl-induced ocular hypertensive rabbits. In addition, both agents improved the ocular blood flow in the iris, ciliary body, retina and choroid. Vaninolol and eugenolol of 10 microM inhibited the basal cAMP accumulation from 23.9 +/- 2.0 of control to 8.7 +/- 0.4 and 2.4 +/- 0.1 respectively and inhibited the isoproterenol-induced cAMP accumulation from 154.3 +/- 13.6 to 120.6 +/- 8.3 and 74.2 +/- 6.1 respectively in the porcine ciliary body. The cellular cAMP concentration was significantly increased from 10 +/- 1 of control to 96 +/- 5 (vaninolol) and 38 +/- 3 (eugenolol) in cultured A7r5 smooth muscle cells. Both agents also increased the intracellular calcium concentration in A7r5 cells.

CONCLUSIONS

These results indicate that the lowering of intraocular pressure by vaninolol and eugenolol may be due to cAMP suppression in the ciliary body by beta-antagonist and/or alpha2-agonist activities. Both agents cause vasodilation via beta2-agonist action that increase the smooth muscle cellular cAMP level more than vasoconstriction via alpha-agonist activity by increasing an influx of extracellular Ca+2.

Application of gas chromatography/electron capture negative chemical ionization high-resolution mass spectrometry for analysis of DNA and protein adducts

The analytical potential of gas chromatography/electron capture negative chemical ionization high-resolution mass spectrometry (HRMS) for characterization and quantitation of DNA and hemoglobin adducts was demonstrated using three model compounds: N2, 3-ethenoguanine (EG), 7-(2-hydroxyethyl)guanine (7-HEG), and N-(2-hydroxyethyl)valine (HEV). At a resolving power of 10 000, the signal-to-noise (S/N) ratios obtained from quantitative selected ion monitoring (SIM) experiments using biological samples were comparable to or better than existing unit mass resolution experiments due to the reduction of chemical noise from the use of narrower mass windows. The specificity gained by HRMS was essential for quantitation of ultratrace amounts near the limit of detection since coeluting interferences of the analyte or internal standard can lead to inaccurate measurement of response factors. The limit of detection (LOD) was 100 amol (S/N = 5) using a pure standard of TTB2-EG. The LOD for complete assays using spiked samples was 500 amol (S/N = 5) for EG and 600 amol (S/N = 5) injected for 7-HEG. The standard deviation (SD) for the HRMS quantitative measurements was typically less than 10%. The SD for the complete biological assays as determined by spiking replicate samples was less than 15%. This method has adequate sensitivity and specificity to accurately measure DNA and protein adducts as low as endogenous concentrations in rodent and human tissues.