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Biomedical subjects

C A Eddy

Publications and source records attributed to C A Eddy.

At least 19 recordsLinked to original sources
PubMed1992

The glycoprotease of Pasteurella haemolytica A1 eliminates binding of myeloid cells to P-selectin but not to E-selectin.

HL-60 cells and neutrophils treated with the glycoprotease from Pasteurella haemolytica A1, an enzyme which is specific for O-sialoglycoproteins, were found to be incapable of binding P-selectin but still bound E-selectin. Comparative analysis of [35-S] cysteine labeled proteins from HL-60 cells by 2-dimensional electrophoresis indicated that two major proteins with M(r) 100 and 115 kd were significantly removed from cells which had been treated.

Antigens, CD↗
PubMed1992

Expression of a human chimeric transferrin gene in senescent transgenic mice reflects the decrease of transferrin levels in aging humans.

Transgenic mice provide a means to study human gene expression in vivo throughout the aging process. A DNA sequence containing 668 bp of the 5' regulatory region of the human transferrin gene was fused to the bacterial reporter gene chloramphenicol acetyl transferase (TF-CAT) and introduced into the mouse genome. Expression of the human chimeric transferrin gene was similar to the tissue patterns of mouse and human transferrin. In aging transgenic mice, expression of the human chimeric transferrin gene was found to diminish 40% in livers between 18 and 26 months of age. Transferrin levels and serum iron levels in aging humans also diminish, as observed from measurements of total iron binding capacity and percent iron saturation in sera from 701 individuals ranging from 0 to 99 years of age. In contrast, in transgenic mice and nontransgenic mice, the mouse endogenous plasma transferrin and endogenous Tf mRNA increase significantly during aging. Neither the decrease of human TF-CAT nor the increase of mouse transferrin during aging appears to be part of a typical inflammatory reaction. Although the 5' regions of the human transferrin and mouse transferrin genes are homologous, sequence diversities exist which could account for the different responses to inflammation and aging observed.

Adolescent↗
PubMed1992

Rabbit endosalpinx inhibits implantation in vitro.

OBJECTIVE: To evaluate the ability of rabbit endometrial or endosalpingeal cells to support implantation in vitro and to assess the effects of endosalpinx and endometrium-conditioned media (CM) on blastocyst-endometrial cell interaction. DESIGN: In one experiment, rabbit blastocysts were co-cultured in vitro with endometrial or endosalpingeal cells growing on Matrigel-coated plastic culture plates or Millicell-HA inserts. In a second experiment, rabbit blastocysts were co-cultured with endometrial cells in the presence of fresh medium or of endosalpinx- or endometrial-CM. After 48 or 72 hours attachment to the cell monolayer was evaluated. RESULTS: Blastocysts in co-culture attached to endometrial but not to endosalpingeal monolayers. The addition of CM from cultured endosalpinx significantly decreased embryo attachment to endometrial cells in culture. CONCLUSIONS: These findings in vitro agree with the observation that rabbit endosalpinx in vivo does not support embryo implantation and support the hypothesis that rabbit endosalpinx secretes a factor that prevent tubal implantation.

Animals↗
PubMed1990

Human transferrin. Expression and iron modulation of chimeric genes in transgenic mice.

Transferrin (TF) is a plasma protein that transports and is regulated by iron. The aim of this study was to characterize human TF gene sequences that respond in vivo to cellular signals affecting expression in various tissues and to iron administration. Chimeric genes were constructed containing 152, 622, and 1152 base pairs (bp) of the human TF5'-flanking region with the coding region of a reporter gene, CAT (chloramphenicol acetyltransferase), and introduced into the germ line of mice. Transgenes containing TF 5'-flanking sequences to -152 bp were expressed poorly in all tissues examined. In contrast, transgenes containing TF sequences to -622 or -1152 bp were expressed at high levels in brain and liver, greater than or equal to 1000-fold higher than tissues such as heart and testes. Liver and brain are major sites of endogenous TF mRNA synthesis, but liver mRNA levels are 10-fold higher than brain. A significant diminution of CAT enzymatic activity in liver accompanied iron administration in both TF(0.67) and TF(1.2)CAT transgenic mice, mimicking the decrease of transferrin in humans following iron overload. Levels of endogenous plasma transferrin also decreased in iron-treated transgenic mice. Transgenic mouse lines carrying human TF chimeric genes will be useful models for analyzing the regulation of human transferrin by iron and for determining the molecular basis of transferrin regulation throughout mammalian development into the aging process.

Animals↗
PubMed1990

Rabbit endosalpinx suppresses ectopic implantation.

This study was undertaken to elucidate the mechanism underlying the absence of oviductal ectopic pregnancies in infraprimates. Endosalpingeal circumferential grafts were substituted for endometrium in a group of rabbits. The endosalpingeal grafts interfered with implantation as evidenced by four observations: (1) The nidation indices were lowered, (2) no implantations occurred on the grafted endosalpinx, (3) unattached blastocysts were found in animals grafted with endosalpinx, and (4) the implantation sites were significantly smaller in uterine horns containing endosalpingeal grafts. These findings suggest the presence of a factor in rabbit endosalpinx that actively suppresses ectopic implantation in the oviduct.

Animals↗
PubMed1989

Effect of ovarian endometriosis on ovulation in rabbits.

To study the relationship between endometriosis and ovulatory dysfunction, we induced ovarian endometriosis in the rabbit model Adipose tissue was placed in the contralateral ovary as a control. Ovulation was induced with human chorionic gonadotropin, and ovulation points were counted before and after induction of endometriosis. Periovarian adhesions were graded, and ovaries were histologically examined. A significant decrease in the number of ovulation points was observed in ovaries with endometrial tissue (p = 0.001) but not in ovaries that contained adipose tissue (p = 0.095). Periovarian adhesions decreased the number of ovulation points (p less than 0.01) in ovaries that contained adipose or endometrial tissues. Multivariate analysis demonstrated that an increase in adhesion severity was correlated with a decrease in the number of ovulation points (p less than 0.05), but endometrial tissue was not (p = 0.45). We conclude that, in the rabbit model, minimal ovarian endometriosis impairs ovulation primarily through a mechanism related to periovarian adhesions.

Analysis of Variance↗
PubMed1989

A new method of transcervical female sterilization: preliminary results in rabbits.

In search of an outpatient procedure for female sterilization, the authors performed the following animal study. Two groups of seven rabbits were subjected to laparotomy, hysterotomy, and hysteroscopy. The uterotubal junction (UTJ) was destroyed with bipolar electrical current, and a plug (Aqualloy, Drachten, The Netherlands) was inserted. The plug on the right side contained quinacrine (Q) in group A and platelet extract (PE) in group B. Histologic assessment by serial sections indicated occlusion of the UTJ in all but one case (96% success rate). This one failure is attributed to the technical difficulties associated with hysteroscopy in the rabbit. The authors project that this method may have the potential of becoming an acceptable outpatient procedure for female sterilization in the human.

Animals↗
PubMed1988

Antibodies to Chlamydia trachomatis and risk for tubal pregnancy.

We performed a case-control study of the effect of exposure to Chlamydia trachomatis on the risk for tubal pregnancy. Sixty women with tubal pregnancies and 60 matched control women with normal second-trimester intrauterine pregnancies were studied. Cases were more likely than controls to have detectable antichlamydial IgG antibodies (82% versus 58%, p less than 0.01) and their mean titers were higher. The prevalence of IgM antibody seropositivity was not different between cases and controls (20% versus 12%, not significant). Compared with women with IgG antibody titers of less than or equal to 1:8 the relative risk for tubal pregnancy for women with titers greater than or equal to 1:128 was 6.6 (95% confidence interval, 2.0 to 21.6). Among women with tubal pregnancies, antichlamydial antibody titers of greater than or equal to 1:128 were significantly associated with pelvic adhesions and inflammatory tubal mucosal damage. Only 17.6% of women with detectable antichlamydial antibody or inflammatory tubal damage reported a history of pelvic inflammatory disease or gonorrhea.

Adult↗
PubMed1986

The use of prostacyclin analogue-containing suture for the prevention of postoperative venous thrombosis in the rat.

The ability of prostacyclin analogue incorporated into a controlled-release suture to prevent postoperative venous thrombosis was investigated. Thirteen rats underwent bilateral transection and anastomosis of the common femoral vein. In each animal, polycaprolactone suture containing 0.25 micrograms/cm of the prostacyclin analogue Iloprost (Schering Ag, Berlin, West Germany) was used to perform the anastomosis on one vessel. Similar suture without prostacyclin analogue was used on the contralateral vessel, which served as a control. Functional patency and luminal surface morphology were assessed 24 hours postoperatively. All anastomoses performed using suture containing prostacyclin analogue were patent. Among controls, five anastomoses were patent and eight were occluded. This difference was highly significant (p less than 0.005). All anastomoses performed with prostacyclin analogue-containing suture exhibited a uniform absence of thrombosis. In contrast, eight control veins exhibited a dense, well-organized fibrinous clot that filled the entire lumen, effectively sealing off the vessel. These results suggest that the prostacyclin analogue released from the suture was highly effective in inhibiting thrombus formation without adversely affecting the vessel's ability to achieve hemostasis.

Animals↗
PubMed1986

Pregnancy rate in timed-mated, spontaneously cyclic rhesus monkeys, Macaca mulatta.

After detection of the preovulatory oestradiol-17 beta peak in blood, females were placed with a male and left undisturbed during mating (N = 28, 94 cycles) or were exposed to serial diagnostic laparoscopy (1-4 occasions) to monitor ovulation (N = 87, 224 cycles). A total of 86 pregnancies resulted from timed mating in the 318 menstrual cycles (27% rate). When periovulatory laparoscopy was performed, the pregnancy rate was 22.3%. In the absence of laparoscopy the pregnancy rate was 38.3% (P less than 0.003). These pregnancy rates are similar to those of women and show an adverse effect of laparoscopy on pregnancy rate.

Animals↗
PubMed1986

Anatomy and pathology of tubal pregnancy.

The prevalence of tubal pregnancy has increased markedly during the past decade. The reasons for this are obscure. A systematic gross and histopathologic study of 25 consecutive ectopic pregnancies has been performed using a clearing method not used previously for this purpose. In addition, the presence of the corpus luteum and its location in reference to the tubal pregnancy are documented. Results indicate that trophoblastic spread was predominantly intraluminal in 67% of cases. Intratubal hemorrhage, generally in parallel to trophoblastic spread, often led to marked tubal destruction. Histologic evidence of salpingitis was noted in only seven of 24 specimens (29%). The corpus luteum was contralateral to the ectopic pregnancy in five of 21 cases (23.8%). Clinical correlates and areas of future research are discussed. Results indicate that segmental resection of the tubal pregnancy is appropriate in selected cases.

Adolescent↗
PubMed1979

Electrophysiology of the rabbit oviduct following tubal microsurgery.

The ability of tuboplastic microsurgery to restore electrical continuity across an anastomosis site was investigated in the rabbit. Three to six weeks following transection and end-to-end anastomosis of the tubal ampulla or isthmus, the pattern of electrical activity adjacent to and across the anastomosis site was examined. Recordings were made in vitro using arrays of closely spaced suction electrodes 68 to 72 hours after an ovulating dose of human chorionic gonadotropin. The pattern of electrical activity across anastomosis sites was not significantly different from corresponding portions of unoperated control oviducts. Microsurgical anastomosis restored electrical continuity between anastomosed segments in both the ampulla and isthmus.

Action Potentials↗
PubMed1978

The role of cilia in fertility: an evaluation by selective microsurgical modification of the rabbit oviduct.

Fertility, ovum transport, and ciliary activity were examined in 35 rabbits after either unilateral microsurgical reversal or double transection (surgical controls) of 1 cm. segments of distal, middle, or proximal ampulla. Fertility was also examined following similar segmental reversal at the level of the distal and proximal isthmus in eight additional rabbits. Reversal of 1 cm. segments of distal, middle, or proximal ampulla effectively prevented pregnancy. In contrast, control animals that underwent double transection without reversal experienced unaltered fertility. Reversal of 1 cm. segments of distal or proximal isthmus was also consistent with normal fertility. Ova placed on the fimbrial surface of oviducts that had undergone ampullary segmental reversal were arrested at the distal anastomosis of the reversed segment. When mechanically displaced into the reversed segment, such ova were transported toward the ovary and were again arrested at the distal anastomosis. Transampullary transport of ova was normal in doubly transected controls. Ova were transported across both anastomosis sites to the ampullary isthmic junction. Studies of ciliary activity confirmed that cilia within reversed segments of ampulla beat in the ovarian direction, counter to that in the rest of the oviduct. Direction of ciliary beat remained unaltered in surgical controls. These experiments demonstrate a critical role of tubal cilia in ovum transport through the rabbit ampulla. In contrast, other mechanisms control ovum transport into and through the tubal isthmus.

Animals↗
PubMed1978

Temporal relationships of estrogen, progesterone, and luteinizing hormone levels to ovulation in women and infrahuman primates.

These studies were undertaken to ascertain the interval between the estrogen and LH peaks and ovulation in women, rhesus monkeys, and baboons. Estrogen, progesterone, and LH were measured by RIA. Ovulation was documented by visual examination of the ovaries, histology of the corpora lutea, and recovery of ova. The data for human subjects was based on a group of 23 normal women scheduled for surgical sterilization. Blood was drawn daily between 8:30 and 10:30 P.M. beginning on day 10 of the cycle. Surgery was performed 1 to 5 days after the LH peak. The hormonal findings were correlated with the histology of the corpus luteum. The mean interval from the estrogen peak to ovulation was 34 hours, the interval from the estrogen peak to the LH peak was 24 hours, and that from the LH peak to ovulation was 9 hours. In 46 rhesus monkey cycles and in 53 baboon cycles diagnostic serial laparoscopic examinations were initiated following the estrogen peak and repeated every 24 hours until ovulation was confirmed. The mean interval between the estrogen peak and ovulation was 34 hours in the monkey and 41 hours in the baboon. The intervals from the estrogen peaks to the LH peaks were 12 hours in the monkey and 23 hours in the baboon. The intervals from LH peak to ovulation were 22 hours in the monkey and 18 hours in the baboon. Plasma progesterone levels were significantly increased prior to the LH peak in all three species.

Adult↗