Protein targets in red complex pathogens for catechin

The development of antimicrobial drug resistance has encouraged scientists to develop alternate methods to combat infectious pathogens associated with dental diseases. Therefore, it is of interest to predict interactions for catechin (a plant derived compound) with protein targets in the red complex pathogens using computer aided network tools. However, in vitro and in vivo studies are warranted to confirm the antimicrobial effect of catechin (gallocatechin, epicatechin, epigallactocatechin (EGC) and gallolyl catechins) on the dental pathogens.     

Cell-to-cell communication of equine uterine tube (oviduct) cells as determined by anchored cell analysis in culture

Cell culture systems using uterine tube (oviduct) epithelial cells (UTEC) have been described in several species; however, the presence and relative degrees of cell coupling occurring between these cells is unknown. This study was done to evaluate the cell-to-cell communication of cultured equine UTEC obtained from mares in the follicular phase. Monolayers of cells were grown from either primary explants or from passaged and frozen-thawed UTEC. Cell-to-cell communication via gap junctions was measured by an anchored cell analysis and sorting computerized workstation. The UTEC were labeled with carboxyfluorescein diacetate. Specific cells located in cell aggregates were photobleached, then the percentage of fluorescence recovery through gap junction mediated dye diffusion from neighboring cells was determined. Levels of cell communication and changes in intracellular calcium were also measured for UTEC before and after the addition of stallion sperm cells to the cell aggregates. The UTEC of both primary and passaged frozen-thawed cells showed cell coupling in vitro, with almost all cells having some fluorescence recovery. There was no difference in the percentage of fluorescence recovery seen between primary or passaged frozen-thawed UTEC cell groups (P = 0.24). The addition of sperm cells to the monolayer cells increased intracellular UTEC calcium levels (P < 0.001). There was also a tendency (P = 0.07) for UTEC coupling to increase in sperm cell co-culture. However, UTEC contraction and movement of the monolayer cells after co-culture with sperm cells made it difficult to accurately follow individual cells with a fluorescence-based anchored cell analysis and sorting workstation. This study indicates that equine UTEC display gap junction mediated cell communication in culture.     

Effects of cooling rate and storage temperature on equine spermatozoal motility parameters

Two experiments were conducted to examine the effects of cooling rate and storage temperature on motility parameters of stallion spermatozoa. In Experiment 1, specific cooling rates to be used in Experiment 2 were established. In Experiment 2, three ejaculates from each of two stallions were diluted to 25 x 10(6) sperm/ml with 37 degrees C nonfat dry skim milk-glucose-penicillin-streptomycin seminal extender, then assigned to one of five treatments: 1) storage at 37 degrees C, 2) storage at 25 degrees C, 3) slow cooling rate to and storage at 4 degrees C, 4) moderate cooling rate to and storage at 4 degrees C, and 5) fast cooling rate to and storage at 4 degrees C. Total spermatozoal motility (TSM), progressive spermatozoal motility (PSM), and spermatozoal velocity (SV) were estimated at 6, 12, 24, 48, 72, 96 and 120 h postejaculation. The longevity of spermatozoal motility was greatly reduced when spermatozoa were stored at 37 degrees C as compared to lower spermatozoal storage temperatures. At 6 h postejaculation, TSM values (mean % +/- SEM) of semen stored at 37 degrees C, slowly cooled to and stored at 25 degrees C or slowly cooled to and stored at 4 degrees C were 5.4 +/- 1.1, 79.8 +/- 1.6, and 82.1 +/- 1.6, respectively. Mean TSM for semen that was cooled to 4 degrees C at a slow rate was greater (P<0.05) than mean TSM of semen cooled to 4 degrees C at a moderate rate for four of seven time periods (6, 24, 72 and 120 h), and it was greater (P<0.05) than mean TSM of semen cooled to 4 degrees C at a fast rate for five of seven time periods (6, 12, 24, 72 and 120 h). Mean TSM of semen cooled to 4 degrees C at a slow rate was greater (P<0.05) than mean TSM of semen cooled to 25 degrees C for five of seven time periods (24 to 120 h). A similar pattern was found for PSM. Mean SV of semen cooled to 4 degrees C at a slow rate was greater (P<0.05) than mean SV of semen cooled to 25 degrees C for all time periods. A slow cooling rate (initial cooling rate of -0.3 degrees /min) and a storage temperature of 4 degrees C appear to optimize liquid preservation of equine spermatozoal motility in vitro.     

Effect of storage time and temperature on stallion sperm DNA and fertility

We used the sperm chromatin structure assay (SCSA) to study the change in stallion sperm DNA susceptibility to denaturation after exposure of extended semen to three different storage temperatures (5, 20, or 37 degrees C) at 7, 20, 31, and 46 h. In addition, we compared the rates of sperm DNA denaturation in fertile and subfertile stallions. Among fertile stallions, spermatozoa stored at 20 and 37 degrees C showed a significant (P < 0.05) rise in the SCSA measures (Mean(alpha1), S.D.(alpha(t)), and percent cells outside the main population-COMP(alpha(t))) overtime, with the degree of rise being more dramatic at 37 degrees C. Over all stallions, samples stored at 5 degrees C showed no significant (P > 0.05) changes in the SCSA values measured over time, indicating maintenance of chromatin quality for up to 46 h. The COMP(alpha(t)) from stallions classified as subfertile showed an increased susceptibility to denaturation or decline in chromatin quality between 20 and 31 h when stored at 5 degrees C; however, spermatozoa from fertile stallions did not change during the time intervals analyzed. These data suggest that sperm DNA from some subfertile stallions may decline at a greater rate than spermatozoa from fertile stallions when exposed to similar storage conditions.     

Insulin-like growth factor-I and insulin-like growth factor binding protein-2 and -5 in equine seminal plasma: association with sperm characteristics and fertility

The objectives of this study were 1) to determine whether insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding proteins (IGFBPs) were present in seminal plasma of stallions; 2) to compare semen parameters (IGF proteins, sperm numbers, morphology, and motility) from stallions at sexual rest (SR) and when sexually active (SA); 3) to compare semen parameters between stallions with high and low seminal plasma IGF-I concentrations; and 4) to examine the relationship between seminal plasma IGF-I concentrations and fertility parameters of stallions. Ejaculates were collected from stallions at SR (n = 51) and SA (n = 46). Concentrations of IGF-I and IGFBP-2 in seminal plasma samples were determined by radioimmunoassay. Presence of IGFBPs in equine seminal plasma was verified using immunoprecipitation and Western ligand blot procedures. IGF-I, IGFBP-2, and IGFBP-5 were present in equine seminal plasma. Concentrations of IGF-I, IGF-I/protein, total IGF-I, IGFBP-2, IGFBP-2/protein, and total IGFBP-2 were not significantly different (P > or = 0.13) in seminal plasma between stallions at either SR or SA. At SR, stallions with higher seminal plasma IGF-I had more total IGFBP-2 per ejaculate (P < 0.01), more morphologically normal sperm (P = 0.05), and higher first-cycle pregnancy rates (P = 0.02). At SA, stallions with higher seminal plasma IGF-I had fewer cycles per pregnancy (P = 0.02). An association of seminal plasma IGF-I concentration with sperm motility, sperm morphology, and pregnancy rates in bred mares suggests that IGF-I may play a role in sperm function.     

Water Balance in Cucumis Plants, Measured by Nuclear Magnetic Resonance, II

Nuclear magnetic resonance (NMR) was used to investigate theeffects of changes in root temperature, of changes in the areaof root in contact with culture solution and of day/night rhythmon the water balance of a cucumber and a gherkin plant. Resultsare discussed in terms of water potential, flow rate and resistanceusing a previously presented model of water balance. As longas water uptake alone is varied, flow rate and water content(or potential) will change in the same direction. In contrast,from that model it is predicted that changes in transpirationwill affect flow rate and water content in opposite ways. Anexperimental verification of this prediction was given in theprevious paper. Results obtained by the NMR method are comparedto those determined using a dendrometer. The results demonstratethat the NMR method is a valuable tool to study plant waterbalance and that it can serve as a technique for discriminatingbetween changes in plant water balance that are due to changesin water uptake by roots and those due to changes in transpiration. Key words: Water balance model, Cucumis satious L., flow, water content, NMR, water balance measurement     

The extensins

The plant cell was includes a matrix which is species specific and which chages in composition during growth and development. Characterization of the protein component of the wall matrix has resulted in the purification of extensin and the genes which encode it. Analysis of the protein sequences for the extensins has provided clues about the types of interactions which may occur as the chemistry and architecture of the cell wall accommodate growth and development.     

Dose-related effects of low dose aspirin on hemostasis parameters and prostacyclin/thromboxane ratios in late pregnancy

Background: The purpose of this study was to determine which low dose of low dose aspirin (LDA) optimized the urinary prostacyclin (PGI₂)/thromboxane (TXA₂) ratio and minimized evidence of platelet aggregation during normal late pregnancy.Methods: Twelve women with uncomplicated singleton pregnancies between 28 and 34 weeks gestation participated in a randomized blinded study. Blood samples for salicylate levels were obtained pretreatment, 4 hours and 7 days after administration of placebo, 20mg, 40mg or 80mg of aspirin. Twenty-four hour urine specimens collected at the same intervals were assayed for PGI₂ and TXA₂ metabolites. In addition, bleeding time and platelet aggregation studies were performed prior to and after 7 days of LDA or placebo.Results: A dose-related increase in bleeding time occurred with 40 mg and 80 mg of LDA, but not with the 20 mg dose or placebo. Platelet aggregation studies changed progressively from a normal baseline to abnormal with an increasing dose of LDA. The ratio increased with aspirin doses as low as 20mg, with a decrease in TXA₂ metabolites but not in PGI₂ metabolites. Serum salicylate was not detectable in any sample from any patient.Conclusion: There are dose-related changes in platelet aggregation and bleeding times with progressively increasing doses of LDA. A lower dose of LDA, such as 20–40 mg per day, may be as efficacious as higher doses in the prophylaxis of pre-eclampsia in high risk populations.     

Evolutionary history of the COII/tRNALys intergenic 9 base pair deletion in human mitochondrial DNAs from the Pacific

Length changes in human mitochondrial DNA (mtDNA) are potentially useful markers for inferring the evolutionary history of populations. One such length change is a nine base pair (9-bp) deletion that is located in the intergenic region between the COII gene and the Lysine tRNA gene (COII/tRNALys intergenic region). This deletion has been used as a genetic marker to trace descent from peoples of East Asian origin. A geographic cline of the deletion frequency across modern Pacific Islander populations suggests that the deletion may be useful for tracing prehistoric Polynesian origins and affinities. Mitochondrial DNA sequence variation within two variable segments of the control region (CR) permits a number of inferences regarding the evolutionary history of the 9-bp deletion that cannot be determined from frequency data alone. We obtained CR sequences from 74 mtDNAs with the 9-bp deletion from Indonesia, coastal Papua New Guinea (PNG), and American Samoa. Phylogenetic and pairwise distribution analysis of these CR sequences pooled with previously published CR sequences reveals that the deletion arose independently in Africa and Asia and suggests possible multiple origins of the deletion in Asia. A clinal increase of the frequency of the 9-bp deletion across the three Pacific populations is associated with a decrease in CR sequence diversity, consistent with founder events. Furthermore, analysis of pairwise difference distributions indicates an expansion time of proto-Polynesians that began 5,500 yr ago from Southeast Asia. These results are consistent with the express train model of Polynesian origins.      

Cardiac Myxomas: Report of Eight Cases with Successful Excision

Early diagnosis of atrial myxoma can be made by a high index of suspicion in patients in whom embolic phenomena, systemic manifestations, syncope, or suspected mitral or tricuspid valvular disease are noted. When the presence of an atrial myxoma is suspected, echocardiographic evaluation should be done promptly. This noninvasive technique has no morbidity or mortality and is accurate in greater than 90 percent of cases.