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Biomedical subjects

A King

Publications and source records attributed to A King.

At least 469 records · Page 26Linked to original sources
PubMedDate not supplied

Sperm velocity in seminal plasma and the association with gender of offspring.

The gender of the offspring is determined by the fertilizing sperm. Previous gender studies were based on washed sperm, but not on sperm in seminal plasma. The objective was to correlate motility parameters assessed during semen analyses with the offspring gender. For comparison, fixed sperm head DNA quantitated by Hoechst 33342 fluorescence microscopy was also analyzed. Forty-six patients undergoing assisted reproduction procedures resulted in livebirth deliveries with either male or female-predominant offsprings. Sperm head fluorescence was weakly correlated to the gender in 61% of the cases. Sperm of patients with male offsprings had slower curvilinear (44.2 +/- 1.8 mean +/- SEM, versus, 49.9 +/- 2.7 micro /sec) and slower average path velocities (32.4 +/- 1.2 versus 36.3 +/- 1.7 micro /sec). Using cut-off values for the curvilinear (< 49 micro /sec) and average path (< 36 micro /sec) velocities of sperm swimming in seminal plasma, the two parameters predicted 75 and 68% of the male offspring births, respectively. The data suggest that sperm movement in seminal plasma is a marker for factors that skew the ratio of the X- to Y-sperm populations.

Benzimidazoles↗
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Sperm apoptosis in nonpregnant luteal phase sera after in vitro fertilization as assessed by comparative genomic hybridization.

Toxicity in serum has been reported in cases of recurrent spontaneous abortions and endometriosis. The null hypothesis was that serum toxicity was not involved in failed pregnancies after in vitro fertilization procedures. The objective was to expose donor sperm to pregnant versus nonpregnant patient sera and analyze for sperm DNA damaging effects using a novel comparative genomic hybridization method. Luteal phase sera (N = 21 cases) were drawn one week after embryo transfer. Colloid-washed donor sperm were incubated (48 h, 37 degrees C, 5% CO2 in air) in 0% or 50% sera. Single-stranded DNA (ssDNA) of control sperm were stained in Hoechst 33342 and hybridized to Sybr Gold-stained ssDNA of sera-treated sperm. Image analyses were performed and fluorescent intensities analyzed. Nonpregnant patient sera (57% of cases) were associated with DNA fragmentation (64.4 +/- 8.8 pixels; mean +/- S.E.M.) when compared with pregnant patient sera (106.3 +/- 8.4 pixels). There were no differences in the sera of biochemical (108.2 +/- 15.3) versus clinical pregnancy cases (105.3 +/- 11.4). The results suggest that nonpregnant patient sera contained factor(s) that cause DNA fragmentation leading to pregnancy losses.

Blood Proteins↗
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Correlation of sperm parameters with apoptosis assessed by dual fluorescence DNA integrity assay.

Failed fertilization after intracytoplasmic sperm injection or miscarriages occurs in cases involving apoptotic and necrotic sperm. Identifying normal sperm is important for successful assisted reproductive technologies (ART) procedures. The study was conducted to correlate sperm parameters with intact sperm with normal DNA assessed by the dual stain assay in 118 separate individuals. The results showed differences in percent DNA intact sperm in individuals with normal W.H.O. sperm features (62 +/- 1.1; mean +/- S.E.M.) compared with oligoasthenoteratozoospermia patients (38 +/- 5.3). Individuals whose sperm had fertilizing capacity had higher percentages of intact DNA (60 +/- 1.3 versus 47 +/- 2.4). The percentages of intact DNA sperm were significantly correlated to total motility in semen (R = 0.7), post-wash motility (R = 0.6), rapid progression (R = 0.6), intact acrosome (R = 0.5), and strict morphology (R = 0.5). There were no correlations with the remaining parameters. The dual stain assay identified sperm with normal physiology and fertilizing capacity. The dual stain assay measures DNA integrity and is a promising method to select normal sperm for ART.

DNA↗
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Aggregation of human sperm at higher temperature is due to hyperactivation.

Chemotaxis of sperm cells to chemicals and hormones, such as progesterone, helps us to understand the concept of sperm transport. Here, the hypothesis was that heat increased sperm hyperactive motility, which caused the sperm to aggregate at the higher temperature. The objectives were (1) to determine the concentration of sperm at both halves of an artificial female reproductive tract made from a hermetically sealed cryopreservation straw filled with culture medium and placed with each end at different temperatures, and (2) to analyze the motility or kinematic parameters and hyperactivation of sperm found at the different temperatures. Cryopreserved-thawed human donor sperm (N = 6) were pooled and processed through 2-layer colloid solution. Analyses of the motile sperm were carried out and the washed sperm were homogeneously mixed and pipetted into several 0.5-mL French cryopreservation straws and heat-sealed. The control substance, consisting of acid-treated sperm, was also placed in several straws. The plastic straws of sperm were placed half at 23 degrees C and half was at either 37 or 40 degrees C. After 4 h, sperm at different sections of the straws were analyzed using the Hamilton Thorn motility analyzer (HTM-C). After 4 h of incubation, the concentration of sperm was doubled at the 40 degrees C heated half of the straw when compared with the other half of the straw at 23 degrees C. There were no differences in sperm concentration in the straw kept half at 37 degrees C and half at 23 degrees C. There were significantly higher percent motility, mean average path velocity, straight line velocity, lateral head displacement, and percent hyperactivation in sperm at the 40 degrees C temperature. The aggregation of sperm at the higher temperature of 40 degrees C may be due to enhanced motility, increased sperm velocities, and a 10-fold increase in hyperactivation at that temperature. The 37 degrees C temperature was not sufficient to attract sperm. Sperm cells migrating into the higher temperature site of ovulation begin nonprogressive hyperactivation movement, which is the physiological "brake" to detain the sperm at the site of ovulation.

Cell Aggregation↗
PubMedDate not supplied

Comparative activity of the 4-quinolones.

Minimal inhibitory concentrations (MICs) of the 4-quinolones ciprofloxacin, enoxacin, norfloxacin, ofloxacin, pefloxacin, difloxacin, A-56620, and CI-934 are consistent world-wide, with allowances for differences in acquired resistance. MICs of these drugs for Enterobacteriaceae correlate with those of nalidixic acid, but resistance to the quinolones is rare if a breakpoint of greater than 2 mg/L is accepted. Most intestinal pathogens are sensitive. Acinetobacter, Pseudomonas aeruginosa, and other Pseudomonas species except Pseudomonas maltophilia are usually sensitive. Ciprofloxacin is generally the most active of the 4-quinolones against these organisms. All of the new agents have antistaphylococcal activity, but that of norfloxacin and ofloxacin is borderline. Against streptococci, including enterococci and pneumococci, the drugs' activity is moderate or poor. Haemophilus influenzae and Branhamella catarrhalis are very sensitive. Gonococci and meningococci are also highly sensitive to the new agents, but activity against Chlamydia trachomatis and the mycoplasmas is borderline. The organisms associated with nonspecific vaginal infection are not very sensitive. Anaerobes except Bacteroides ureolyticus and Clostridium perfringens are mostly resistant.

Anti-Bacterial Agents↗
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Trophoblast migration during human placental implantation.

During the process of implantation in humans, fetal trophoblast cells invade and migrate into the maternal decidua. During this migration, trophoblast cells destroy the wall of the maternal spiral arteries, converting them from muscular vessels into flaccid sinusoidal sacs. This vascular transformation is important to ensure an adequate blood supply to the feto-placental unit. Both cell-cell and cell-matrix interactions are important for trophoblast invasion of the decidual stroma and decidual spiral arteries. Cell-matrix adhesions are mediated by specific receptors, mostly belonging to the family of integrins. Signals transduced to the cells from the matrix via integrins could play a pivotal role in the control of cellular behaviour and gene expression, such as metalloproteinases that facilitate matrix degradation and tissue remodelling. This review focuses on the role of integrins and extracellular matrix in trophoblast cell migration, trophoblast invasion of the decidual spiral arteries and matrix degradation by trophoblast during implantation.

Arteries↗
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Human uterine lymphocytes.

During the luteal phase and the early months of pregnancy, there is a dense mucosal infiltration of CD56+ natural killer (NK) cells. These uterine NK cells have a phenotype (CD56bright, CD16-, mCD3-) which distinguishes them from peripheral blood NK cells (CD56dim, CD16bright, mCD3-). The uterine NK cells are in close association with extravillous trophoblast (EVT) cells which infiltrate into the decidua and maternal spiral arteries. This subpopulation of trophoblast expresses two human leukocyte antigen (HLA) class I molecules, HLA-G and HLA-C. Circulating NK cells express receptors for HLA class I molecules. We have recently found evidence that similar receptors are present on decidual NK cells belonging to both the Killer Inhibitory Receptor (KIR) and CD94 families. The repertoire of NK receptors expressed varies between different women. The findings indicate that decidual NK cells do have receptors for trophoblast HLA class I molecules. Experiments are underway to determine the effects of this interaction on NK cell function.

Antigens, CD↗
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Uterine leukocytes and decidualization.

The transformation of endometrium into decidua is an essential feature of normal implantation and pregnancy. There is a close association with an unusual leukocyte population, uterine natural killer (NK) cells, and onset of decidualization. These uterine NK cells are seen in close contact with stromal cells ultrastructurally and are also seen encircling vessels and glands. The possibility that uterine NK cells in the late secretory phase and in early decidua may be important in initiating and maintaining decidualization is raised. In contrast, the death of uterine NK cells could be an early event in the onset of endometrial breakdown at menstruation. The period between implantation and menstruation (7-14 days after luteinizing hormone surge) is the time when implantation is known to be particularly vulnerable. In this review, the possibility that uterine leukocytes might influence the critical decision that the mid- to late secretory endometrium must make either to decidualize or to undergo menstruation is explored.

Animals↗
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The spider diagram nursing quality report card: bringing all the pieces together.

The proliferation of information about nurse-sensitive quality outcome measures in the current data-driven healthcare environment can be overwhelming. Effective utilization of such data is an even greater challenge. In this article, the authors describe how the use of a spider diagram can serve to combine data from various sources into more meaningful information for decision making. This innovative quality report card format helps nurse executives to quickly gain an understanding of the interrelationships among existing structure, process, and outcome quality indicators, as well as to identify actual or potential quality-of-care issues.

Benchmarking↗
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Superior mesenteric artery syndrome associated with scoliosis treated by a modified Ladd procedure.

A 16-year-old asthenic girl had idiopathic adolescent scoliosis and superior mesenteric artery (SMA) syndrome. After a Harrington rod procedure, the SMA syndrome produced a complete duodenal obstruction that did not resolve with nasogastric decompression, positioning, or peripheral intravenous nutrition. A complete derotation of the duodenum and the colon and stabilization of their mesentery (Ladd procedure with the Bill modification) resolved the obstruction and was considered the preferred operative treatment for this problem.

Adolescent↗
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Evaluation of a monoclonal antibody, BC-1, which identifies an antigen expressed on the surface membrane of human extravillous trophoblast.

This paper describes a new Mab BC-1 which is directed at a cell surface antigen expressed by extravillous cytotrophoblast and not by villous cytotrophoblast, so it is useful for distinguishing between the two populations. The antigen recognised by BC-1 is trypsin-resistant, which allows it to be used for flow cytometric analysis of living trophoblast isolated by enzymic disaggregation. However, BC-1 is not trophoblast-specific but cross-reacts with some other tissues, in particular endothelial cells and peripheral blood monocytes. The nature of this antigen has not been established.

Animals↗
PubMedDate not supplied

Effect of dextran on cerebral function and blood after cardiac arrest. An experimental study on the dog.

EEG activity and regional cerebral blood flow were monitored during 5 hour survival following cardiac arrest in 32 pentobarbital anesthetized mongrel dogs. The animals were mechanically ventilated and blood gases were maintained at physiologic levels. Regional cerebral blood flow and cardiac output were measured using 15 mu microspheres. EEG was recorded from 6 epidural electrodes using bipolar techniques. The animals were divided into 3 groups. The animals in Group I had an arrest of 8-11 minutes and those in Group II and III had an arrest of 12-16 minutes. Group II animals received no treatment. Group III animals were given 1 g/kg of dextran 40 at a concentration of 10% in normal saline following the arrest and maintained with 10 mg/kg/min during the 5 hours of recovery. In Groups I and III there was shorter duration of a flat EEG and 5 hours after the arrest the EEG activity was closer to normal than in Group II. After 5 hours the EEG scores of Group III were significantly greater than Group II (p less than 0.03). The cortical grey matter and hippocampus had the greatest reduction of blood flow following cardiac arrest. The mean cortical grey matter blood flow in Group II was less than in Groups I and III at 3 hours. After 5 hours the grey matter blood flow was greater in Group III than in Group II (p less than 0.09). The findings of this study are consistent with the hypothesis that after cardiac arrest perfusion abnormalities persist or develop after return of blood pressure and that these can be corrected or prevented with improved functional survival by treatment with dextran 40 after the arrest.

Animals↗
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Parenteral nutrition-associated cholestasis: recovery following phenobarbitone.

A case is presented of a very preterm neonate who developed severe cholestatic jaundice in association with prolonged parenteral nutrition. The effects of a therapeutic trial of phenobarbitone on bilirubin and liver enzymes are shown. This case suggests that phenobarbitone may have a role to play in the treatment of this condition, which is contrary to indications in a few other case reports in the literature.

Bilirubin↗
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Correlation between intact sperm acrosome assessed using the Spermac stain and sperm fertilizing capacity.

Accurate determination of sperm acrosomal status is important in fertility studies. The objective was to correlate the percentage of intact acrosome assessed using the new Spermac stain with the capacity of sperm to fertilize oocytes. Sperm specimens were processed either by centrifuge wash, 48:95 Percoll gradient or test yolk buffer (TYB) wash, and tested using the zona-free hamster oocyte assay. The results indicated a correlation between the percentage of sperm with intact acrosome reaction and the percentage of sperm penetrating the oocytes in the TYB-washed group. The data suggest the usefulness of the Spermac stain for assessing the acrosomal status and in predicting the fertilizing capacity of the sperm.

Acrosome↗
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Sperm kinetics and morphology before and after fractionation on discontinuous Percoll gradient for sex preselection: computerized analyses.

The multiple-layer discontinuous Percoll density gradient centrifugation procedure is being used for gender selection and several reports suggested separation efficiencies of over 77%. The mechanism involved in the separation of X- and Y-bearing sperm using this method seems to be the difference in sperm head dimensions or motility but supporting data are inconsistent. The specific aims of the study were to evaluate the head dimensions of sperm at the upper and lower fractions after the 8-layer Percoll gradient procedure for sex preselection and to ascertain the kinematic parameters and tail lengths of sperm derived from the 2 separate Percoll fractions. Sperm cells were obtained from thawed donor specimens (N = 20) and were layered on top of the 8-layer discontinuous Percoll gradient, which ranged from 34 to 85% in increments of 7%. After centrifugation, the resuspended sperm cells derived from the upper and lower fractions of the Percoll gradient were analyzed on the Hamilton Thorn HTM-C analyzer for differences in sperm motility patterns and sperm head dimensions. Aliquots of sperm from the 2 fractions were fixed and stained using the Spermac stain, and the lengths of each sperm tail (N = 600) were measured on the HTM-C analyzer. Sperm derived from the bottom Percoll (X) fraction had a threefold higher (p < .05) percent motility when compared with sperm from the top (Y) fraction. Sperm derived from the bottom (X) fraction maintained the higher percentage motility after 24 h of incubation. The percent total progression, rapid progression, and hyperactivation were also significantly higher (p < .05) in sperm from the bottom (X) fraction. Similarly, the curvilinear (Vcl), average path (Vap) and straight line (Vsl) velocities were significantly faster in sperm (p < .05) from the bottom (X) fraction. In contrast, the percent linearity and straightness were significantly (p < .05) higher for the top (Y) fraction. Sperm from the bottom (X) fraction have shorter (p < .07) tail length (1.6% difference) when compared with sperm from the top (Y) fraction. Although the dimensions of the sperm head from the bottom (X) fraction were numerically greater than top fraction sperm, they were not significant (p > .05). The results suggest that bottom (X) fraction sperm derived from the 8-layer discontinuous Percoll gradient for sex preselection have higher motility, progression, and hyperactivation when compared with top (Y) fraction sperm. The bottom (X) fraction sperm have greater longevity in motility and have shorter tails, supporting earlier hypotheses of sex differences in sperm parameters. However, the present data do not support observations of differences in sperm head dimensions in sperm processed for sex preselection, and an inference of a larger sperm due to more chromosome material originating from the X chromosome cannot be made.

Cell Separation↗