[Solid-phase extraction coupled with high-field proton nuclear magnetic resonance spectroscopy: application to the analysis of brodimoprim metabolites in rat urine]

The use of coupled solid-phase extraction and high-field proton nuclear magnetic resonance spectroscopy (SPE-1HNMR) for the detection and identification of the urinary metabolites of brodimoprim is described. Urine was obtained from Wistar rats following a dose of 200 mg.kg-1 of brodimoprim. Analysis was performed on partially purified extracts obtained by solid-phase extraction onto C-18 bonded silica gel. As each spectrum was often given by a mixture of more than two kinds of metabolites, stepwise identification of the individual metabolites was achieved by sorting out signal sets having invariant proportionality. Five kinds of metabolites of the drug were found by the analysis.

An expert system for EEG monitoring in the pediatric intensive care unit

OBJECTIVES

was to design a warning system for the pediatric intensive care unit (PICU). The system should be able to make statements at regular intervals about the level of abnormality of the EEG. The warnings are aimed at alerting an expert that the EEG may be abnormal and needs to be examined.

METHODS

A total of 188 EEG sections lasting 6 h each were obtained from 74 patients in the PICU. Features were extracted from these EEGs, and with the use of fuzzy logic and neural networks, we designed an expert system capable of imitating a trained EEGer in providing an overall judgment of abnormality about the EEG. The 188 sections were used in training and testing the system using the rotation method, thus separating training and testing data.

RESULTS

The EEGer and the expert system classified the EEGs in 7 levels of abnormality. There was concordance between the two in 45% of cases. The expert system was within one abnormality level of the EEGer in 91% of cases and within two levels in 97%.

CONCLUSIONS

We were therefore able to design a system capable of providing reliably an assessment of the level of abnormality of a 6 h section of EEG. This system was validated with a large data set, and could prove useful as a warning device during long-term ICU monitoring to alert a neurophysiologist that an EEG requires attention.

Dispersed repetitive DNA has spread to new genomes since polyploid formation in cotton

Polyploid formation has played a major role in the evolution of many plant and animal genomes; however, surprisingly little is known regarding the subsequent evolution of DNA sequences that become newly united in a common nucleus. Of particular interest is the repetitive DNA fraction, which accounts for most nuclear DNA in higher plants and animals and which can be remarkably different, even in closely related taxa. In one recently formed polyploid, cotton (Gossypium barbadense L.; AD genome), 83 non-cross-hybridizing DNA clones contain dispersed repeats that are estimated to comprise about 24% of the nuclear DNA. Among these, 64 (77%) are largely restricted to diploid taxa containing the larger A genome and collectively account for about half of the difference in DNA content between Old World (A) and New World (D) diploid ancestors of cultivated AD tetraploid cotton. In tetraploid cotton, FISH analysis showed that some A-genome dispersed repeats appear to have spread to D-genome chromosomes. Such spread may also account for the finding that one, and only one, D-genome diploid cotton, Gossypium gossypioides, contains moderate levels of (otherwise) A-genome-specific repeats in addition to normal levels of D-genome repeats. The discovery of A-genome repeats in G. gossypioides adds genome-wide support to a suggestion previously based on evidence from only a single genetic locus that this species may be either the closest living descendant of the New World cotton ancestor, or an adulterated relic of polyploid formation. Spread of dispersed repeats in the early stages of polyploid formation may provide a tag to identify diploid progenitors of a polyploid. Although most repetitive clones do not correspond to known DNA sequences, 4 correspond to known transposons, most contain internal subrepeats, and at least 12 (including 2 of the possible transposons) hybridize to mRNAs expressed at readily discernible levels in cotton seedlings, implicating transposition as one possible mechanism of spread. Integration of molecular, phylogenetic, and cytogenetic analysis of dispersed repetitive DNA may shed new light on evolution of other polyploid genomes, as well as providing valuable landmarks for many aspects of genome analysis.

Temperature-dependent hyperactivated movement of hamster spermatozoa

Immotile hamster spermatozoa from the caudal epididymis were activated in physiological medium at a temperature range between 22 and 40 degrees C. With rising temperature, the sperm swimming velocity and flagellar beat frequency increased, but the flagellar bend angles and waveforms did not change dramatically. All spermatozoa exhibited a symmetric and progressive movement at this temperature range. Hyperactivation was induced by incubating activated spermatozoa in vitro at 37 degrees C for 3.5 h under 5% CO2 in air. When examined at 37 degrees C, spermatozoa expressed a hyperactivated motility characterized by asymmetric and circular flagellar beating with large principal and reverse bends. When the temperature was lowered to 33 degrees C, the sperm motility pattern characteristic of hyperactivation became less prominent. In particular, the reverse bend originating in the flagellar middle piece did not propagate to the principal piece. However, normal hyperactivated movement was restored as the temperature was raised to 37 degrees C, indicating that in vitro expression of hyperactivated motility of hamster spermatozoa is a temperature-dependent phenomenon. To further investigate temperature effects on the flagellar motor apparatus, spermatozoa were demembranated and then reactivated with ATP. In contrast to membrane-intact hyperactivated spermatozoa, demembranated spermatozoa exhibited a hyperactivation-like motility independent of the temperature range tested (22-40 degrees C). This strongly suggests that temperature regulates initiation and maintenance of hyperactivated motility and that its effect is mediated by the plasma membrane.

[Enzynology of infected part of red skin ginseng]

By means of polyacrylaminde gel eletrothoresis and thin layer scanning, the paper semi-quantitatively studies some relation between component and activity of isoenayme of Ginseng infecting red skin desease. The results show activity of esterase increases 100% than that of normal Ginseng; activity of polyphenol oxidase increases 60-30% and represent new isoenzyme bands in the early infection in juxtapose transolant experiment.

[The effect of platelet activating factor on the biosynthesis of thromboxane A2 and prostaglandin I2 in human placental villi and umbilical artery]

OBJECTIVE

To evaluate the effects of platelet activating factor (PAF) on the biosynthesis of thromboxane A2(TXA2) and prostaglandin I2(PGI2) in human chorionic villi and umbilical arteries.

METHODS

We perfused the human placental villi and umbilical arteries with PAF (10(-9)-10(-7) mol/l), then quantified TXB2 and 6-keto-PGF1 alpha in the perfusion fluid by Radioimmunoassay.

RESULTS

PAF stimulated the biosynthesis of TXA2 and PGI2 in human umbilical arteries and chorionic villi in vitro. The production of TXB2 increased from 63.15 +/- 13.24 pg/mg protein to 127.03 +/- 27.76 pg/mg protein with response to the stimulation of PAF (10(-9) mol/L) (P < 0.01). The concentration of PAF (10(-8) mol/L) displayed the most optimal stimulating effect on PGI2 biosynthesis in umbilical artery samples and the production of 6-keto-PGF1 alpha increased from 6,747.52 +/- 700.31 pg/cm to 8,342 +/- 335.81 pg/cm (P < 0.01).

CONCLUSION

PAF may affect the fetal-placental circulation by regulating the local levels of PGI2 and TXA2.

Activation of mammalian sperm motility by regulation of microtubule sliding via cyclic adenosine 5'-monophosphate-dependent phosphorylation

Bicarbonate was found to be essential for activating live mouse sperm motility. The activated sperm flagella exhibited high beat frequency, high swimming velocity, and large principal and reverse bends. To gain further insight into the bicarbonate-triggered activation mechanism, the microtubule sliding characteristics of the activated versus the nonactivated sperm flagella were compared by use of demembranated sperm. We found that the effects of bicarbonate on live sperm were identical with the effects of cAMP on demembranated sperm both in microtubule sliding velocity and in sliding disintegration pattern. Furthermore, autoradiography revealed that the activation of mouse sperm motility was associated with cAMP-dependent phosphorylation of a 65-kDa flagellar protein. The results demonstrated that bicarbonate-triggered activation of mouse sperm motility was closely coupled with the regulation of microtubule sliding via cAMP-dependent phosphorylation.

Extrusion of microtubule doublet outer dense fibers 5-6 associating with fibrous sheath sliding in mouse sperm flagella

Our previous experiments (Si and Okuno [1993a] Exp. Cell Res., 208:170-174) provided evidence that the fibrous sheath (FS) slid headward to middle piece in the activated mouse sperm flagellum when doublet microtubules together with their outer dense fibers (ODFs) extruded from the axoneme. Of the extruded doublet-ODFs, however, which one was responsible for the FS sliding remained unresolved. The present study demonstrated that the FS sliding and the order of doublet-ODFs extrusion in mouse sperm flagella were trypsin concentration dependent. Under the condition of mild trypsinization (0.1 micrograms/ml), only doublet-ODFs 4, 5-6 (doublet-ODFs 5 and 6 were always paired), and 7 extruded from the axoneme. Furthermore, the extrusion of doublet-ODFs 5-6 was identified to precede doublet-ODFs 4 and 7, and was considered the candidate responsible for FS sliding. In contrast, the high-concentration trypsinization (4 micrograms/ml) led to extrusion of doublet-ODFs 1, 2, and 9 following doublet-ODFs 4, 5-6, and 7. FS sliding, however, did not occur.

Differential expression of a lipid transfer protein gene in cotton fiber

A full-length cDNA clone, GH3, has been isolated from a cotton fiber cDNA library using a differential screening method. The nucleotide and derived amino acid sequence data show that GH3 encodes a lipid transfer protein (LTP) of 120 amino acids. The presence of a transmembrane signal peptide at the N-terminal of the protein would suggest its possible outer cellular location in fiber cells. Northern analysis indicates that the GH3 gene is developmentally regulated.

Synthesis and stability of isotopically labeled p-chloro-m-xylenol (PCMX)

The synthesis, reaction kinetics, and pH stability of isotopically labeled p-chloro-m-xylenol (PCMX) were evaluated. While base catalysis was more rapid than acid catalysis, the latter allowed the use of a cosolvent for deuterium and tritium labeling using as little as 250 microL labeled water. Both acid and base catalysis were markedly more rapid than that reported previously for the deuteration of PCMX and related phenols. Isotopic labeling occurred only at the 2 and 6 ring positions, ortho to the phenolic group of PCMX. No deuterium loss was observed after storage for 21 days at 37 degrees C over a pH range of 2-14. Isotopic loss was observed only below pH 2. The prepared 3H-labeled PCMX had a specific activity of 1.18 mCi/mmol, a radiochemical purity of 99.0%, and a chemical purity exceeding 99.0%, with a high stability during prolonged cold storage.

The sliding of the fibrous sheath through the axoneme proximally together with microtubule extrusion

When activated mouse sperm were treated with Triton X-100 and dithiothreitol at pH 9.0, the plasma membrane and mitochondrial sheath of the sperm flagella were removed. These mitochondrion-free demembranated sperm flagella were perfused with Mg-ATP and trypsin to induce the sliding disintegration of microtubules from the axoneme. We observed that when the doublet microtubules associated with outer dense fibers extruded from the axoneme, the fibrous sheath (FS) was pulled proximally to the connecting piece from the annulus of the sperm flagellum accompanying the extrusion of microtubules. Furthermore, the FS sliding was cAMP-dependent and the maximal sliding velocity was about 3.7 +/- 0.1 microns/s in the presence of 1.0 mM ATP at 37 +/- 1 degrees C. Since the FS projected inward and attached opposite doublet microtubules 3 and 8 in the principal piece, our observation showed the possibility that doublet 3 and/or 8 participated in FS sliding.

Multiple activation of mouse sperm motility

To investigate the activation mechanism of mouse sperm motility, the intact sperm in various activities were further investigated after demembranation. When dry sperm was diluted into sucrose solution, the sperm exhibited low motility with the swimming velocity of 13.5 +/- 3.8 microns/s and the beat frequency of 1.5 +/- 0.4 Hz. The demembranated sperm were immotile in the reactivation solution lacking cAMP. Meanwhile, when dry sperm was diluted into the solution containing either high concentration of NaCl or Ca2+, they exhibited the beat frequency of about 9 Hz. The demembranated ones exhibited the intermediate motility in the absence of cAMP. When dry sperm were diluted into the sucrose solution containing HCO3-, the sperm exhibited a vigorous motility with the swimming velocity of 181.2 +/- 10.1 microns/s and the beat frequency of 11.3 +/- 1.2 Hz. The demembranated sperm exhibited the high reactivation motility (90%) and flagellar beat frequency (9 Hz) in the absence of cAMP. These values were almost equivalent to those obtained in the demembranated sperm pretreated with sucrose or Ca2+ or NaCl and reactivated in the presence of cAMP. The activation induced by bicarbonate was considered complete in comparison with the activation by Ca2+ or NaCl. It was likely that the activation of mouse sperm motility took multiple states.

Anti-HIV-1 activity and cellular pharmacology of various analogs of gossypol

We previously reported that the racemic mixture and both enantiomers of gossypol inhibit the replication of human immunodeficiency virus-type 1 (HIV-1) (Lin et al., Antimicrob Agents Chemother 33: 2149-2151, 1989). The present study evaluates the activities of a variety of analogs of gossypol as well as a few non-gossypol analogs. Compounds 2, 3, 10, and 13 were slightly more inhibitory than (-)-gossypol to the replication of HIV-1 in cell culture. Compounds 4 and 8 were cytotoxic to human peripheral blood monocyte (PBM) cells, and compounds 2 and 3 were cytotoxic to Vero cells but not PBM cells. The effects of the two enantiomers of gossypol on the cell volume and migration of H9 cells through the cell cycle were evaluated during 72 hr of incubation. The (-)-enantiomer of gossypol was more toxic to H9 cells than the (+)-enantiomer of gossypol as evidenced by cell destruction. Prior to cell destruction, there appeared to be no significant effect on cell cycle distribution with either enantiomer.