Search PubMed⌕ Search

Biomedical subjects

S Campbell

Publications and source records attributed to S Campbell.

At least 343 records · Page 19Linked to original sources
PubMed1995

The origin of alpha-fetoprotein in first-trimester anembryonic pregnancies.

OBJECTIVE: Our purpose was to evaluate the origin of alpha-fetoprotein in the maternal circulation and coelomic fluid of pregnancies with an empty gestational sac on first-trimester ultrasonographic examination. STUDY DESIGN: The alpha-fetoprotein level and the affinity of alpha-fetoprotein for concanavalin A Sepharose was measured between 8 and 11 weeks of gestation in the maternal serum and coelomic fluid of nine pregnancies complicated by an empty gestational sac and of 27 normal pregrancies. RESULTS: The maternal serum alpha-fetoprotein level in patients with an empty gestational sac was high in seven cases and normal in two cases. In these cases the median level was significantly (p < 0.01) higher in the serum and lower in the coelomic fluid compared with normal pregnancies. In eight cases of the nine pregnancies with an empty sac, > 50% of alpha-fetoprotein molecules in the coelomic fluid were of the concanavalin A nonreactive fraction, whereas in one case the coelomic fluid sample contained < 5% of this fraction. A similar distribution was found in the corresponding serum samples. CONCLUSION: Normal or high maternal serum AFP levels and alpha-fetoprotein molecules predominantly of yolk sac origin in the coelomic fluid of pregnancies with an empty gestational sac on ultrasonography provide further evidence that the most likely explanation for this feature is the early death of the embryo with persistence of the placental tissue.

Embryo, Mammalian↗
PubMed1995

Secretion of prostaglandins and endothelin-1 by decidual endothelial cells from normal and preeclamptic pregnancies: comparison with human umbilical vein endothelial cells.

OBJECTIVE: An increasing amount of circumstantial evidence points to the maternal endothelial cell as centrally involved in the syndrome of preeclampsia. The purposes of this study were (1) to compare the secretion of vasoactive substances by maternal decidual endothelial cells with that of umbilical vein endothelial cells, widely used as a surrogate for endothelial cells in general, and (2) to compare secretion of the same vasoactive substances by decidual endothelial cells from normal and preeclamptic pregnancies. STUDY DESIGN: Endothelial cells were isolated from umbilical veins and from decidual biopsy specimens collected at cesarean section delivery from both normal and preeclamptic women. Cells were maintained in culture until passage 2, when secretion by the three endothelial cell populations of the vasodilators prostaglandin E2 and prostacyclin and the vasoconstrictor endothelin-1 was examined. In addition to control incubations, their responses to stimulation and suppression of secretion were compared. RESULTS: In control incubations normal decidual endothelial cells secreted lower amounts of prostacyclin, prostaglandin E2, and endothelin than did human umbilical vein endothelial cells. All cell types had qualitatively similar responses to the stimuli used, but quantitatively different responses were noted between human umbilical vein endothelial cells and normal decidual endothelial cells for all metabolites examined. Preeclamptic decidual endothelial cells secreted significantly more prostaglandin E2 than did normal decidual endothelial cells in response to stimulation. CONCLUSIONS: We have delineated levels of secretion of vasoactive substances by human late pregnancy decidual endothelial cells and their responses to manipulation of secretory pathways. There are differences between this endothelial cell population and human umbilical vein endothelial cells (which are widely used as a surrogate for maternal endothelial cells). The differences between normal and preeclamptic decidual endothelial cells in prostaglandin E2 secretion may point to altered regulation of arachidonic acid metabolic pathways in preeclampsia.

Cells, Cultured↗
PubMed1995

Fetal oxygenation at cordocentesis, maternal smoking and childhood neuro-development.

OBJECTIVE: To assess the relationship between subsequent neuro-development and measurements in small for gestational age (SGA) fetuses, including oxygenation at cordocentesis. DESIGN: A longitudinal study of a cohort of SGA fetuses using those with normal oxygenation as controls. SUBJECTS: 65 chromosomally normal children aged 12-66 months who, as fetuses, had been small for gestational age, had undergone cordocentesis and had been delivered after 32 weeks' gestation. RESULTS: Griffiths' developmental quotient (DQ) was significantly associated with fetal blood pH (r = 0.41, P = 0.0008), PO2 (r = 0.25, P = 0.047) and PCO2 (r = -0.28, P = 0.027) at cordocentesis but not with the severity of growth retardation (r = 0.18, P = 0.17). However, the significant correlations between DQ and both PO2 and PCO2 were explained by their co-correlations with pH and neither remained significant after removing the effect of pH by analysis of variance. The association between DQ and pH was still significant after removing the effect of confounding variables. Maternal smoking during pregnancy was significantly associated with DQ (F to remove = 6.89, P = 0.011) even after allowing for the effects of possible confounding variables including fetal blood pH. CONCLUSIONS: Both fetal pH at cordocentesis and maternal smoking correlate significantly with subsequent neuro-development. Further investigation into the causes of these associations is required.

Child, Preschool↗
PubMed1995

Fetal venous, arterial, and intracardiac blood flows in red blood cell isoimmunization.

OBJECTIVE: To investigate the effect of anemia on fetal venous, arterial, and intracardiac blood flows. METHODS: Color flow Doppler was used to record flow-velocity waveforms from the atrioventricular valves, ductus venosus, right hepatic vein, inferior vena cava, middle cerebral artery, and descending thoracic aorta from 38 cases of red blood cell isoimmunized pregnancies. Immediately after the Doppler studies, funipuncture was performed and the fetal hemoglobin concentration was measured. RESULTS: Blood flow velocities in the thoracic aorta, middle cerebral artery, and the ductus venosus were increased compared to reference ranges established previously; however, a significant association with the degree of anemia was found only for the velocity in the thoracic aorta. Pulsatility indices in arteries and veins and the ratio of early to late atrioventricular inflow velocities were not significantly different from normal. CONCLUSIONS: Fetal anemia is associated with a hyperdynamic circulation in both arterial and venous vessels. Even in severe anemia, there is no evidence of congestive heart failure. Venous and intracardiac Doppler studies do not provide a clinically useful contribution in the management of red blood cell isoimmunization.

Anemia↗
PubMed1995

Vaginal color Doppler assessment of uterine artery impedance correlates with immunohistochemical markers of endometrial receptivity required for the implantation of an embryo.

OBJECTIVE: To investigate the correlation between uterine artery impedance with immunohistochemical histologic, and ultrasonographic markers of uterine receptivity. DESIGN: A prospective study of subfertile women undergoing a frozen embryo replacement cycle. SETTING: A tertiary infertility clinic. PATIENTS: The study was based on 86 patients who had failed to become pregnant during a standard IVF treatment cycle and who had at least two good quality embryos cryopreserved. INTERVENTIONS: All patients had pituitary desensitization with the GnRH analogue buserelin acetate, followed by E2 and P replacement therapy. Vaginal color Doppler images of both uterine arteries were obtained on days 7, 14, and 21 of the first (trial) cycle. On day 21, an endometrial biopsy was taken for dating a 24-kd protein, placental protein 14, and E2 receptor assessment. After a menstrual bleed had been induced, administration of estrogen and P was reinstituted and embryos transferred to the uterus on the 3rd or 4th day of P administration. MAIN OUTCOME MEASURES: The mean pulsatility index of the left and right uterine arteries, a semiquantitative score of endometrial 24-kd protein, PP14, and E2 receptor assessment, endometrial histologic dating, and pregnancy outcome. RESULTS: Nineteen of 76 patients who had a successful ET became pregnant. The pulsatility index on day 14 of both the trial and ET cycles was significantly lower in those who achieved pregnancy as compared with those who did not conceive: 2.65 (range 1.3 to 3.4) versus 3.85 (1.8 to 6.8) and 2.85 (1.4 to 3.6) versus 4.15 (2.1 to 6.8), respectively. There were significant correlations between pulsatility index and 24-kd protein, E2 receptor, and endometrial histology but not with PP14 and endometrial thickness. CONCLUSIONS: Uterine artery impedance has a significant correlation with biochemical markers of uterine receptivity and accurately predicts the probability of pregnancy in frozen embryo replacement cycles. It is a useful method for assessing uterine receptivity in assisted conception programs.

Adult↗
PubMed1995

Flexural strength of an infused ceramic, glass ceramic, and feldspathic porcelain.

In-Ceram material is a relatively new all-ceramic restorative material with improved properties that require research. The clinical selection of restorative materials is based on a number of parameters such as esthetics, fit, and strength. This study determined the flexural strength of In-Ceram system components and compared the core material with conventional feldspathic ceramics and with Dicor all-ceramic restorative material. Four-point flexural strength values of bend bars of each ceramic were 18.39 +/- 5.00 MPa for In-Ceram sintered alumina, 76.53 +/- 15.23 MPa for In-Ceram infusion glass, and 236.15 +/- 21.94 MPa for In-Ceram infused alumina core. Flexural strength of self-glazed feldspathic porcelain was 69.74 +/- 5.47 MPa, as-cast Dicor ceramic 71.48 +/- 7.17 MPa, and polished Dicor ceramic was 107.78 +/- 8.45 MPa.

Aluminum Oxide↗
PubMed1995

Going monthly.

Explore the source record for details and available documents.

Gynecology↗
PubMed1995

Three-dimensional ultrasound for the assessment of uterine anatomy and detection of congenital anomalies: a comparison with hysterosalpingography and two-dimensional sonography.

The purpose of this study was to investigate the potential value of three-dimensional ultrasound for the assessment of normal uterine anatomy and the diagnosis of congenital uterine anomalies. A total of 61 patients with a history of recurrent miscarriage or infertility and who had previously been investigated by hysterosalpingography were recruited into the study. They first underwent a conventional two-dimensional transvaginal ultrasound scan. At the end of the examination, three-dimensional ultrasound volumes were recorded and stored in the machine computer memory. The examination of planar reformatted sections was than used for the assessment of uterine morphology and the diagnosis of congenital anomalies. On three-dimensional scanning, the most useful plane was a transverse section through the whole length of the uterus from the fundus to the cervix. Hysterosalpingography showed a normal uterus in 44 (72.1%) patients, an arcuate uterus in nine (14.8%) and a major fusion defect in three cases (4.9%). Five patients (8.2%) had large fibroids which were distorting the uterine cavity. Good-quality two-dimensional ultrasound images were obtained in 60 (98.3%) and three-dimensional images in 58 (95.1%) cases. All poor images were caused by large uterine fibroids. Comparison between hysterosalpingography and ultrasound showed that five false-positive diagnoses of arcuate uterus and three of major uterine anomalies were made on two-dimensional scans. Three-dimensional ultrasound agreed with hysterosalpingography in all cases of arcuate uterus and major congenital anomalies. The ability to visualize both the uterine cavity and the myometrium on a three-dimensional scan facilitated the diagnosis of uterine anomalies and enabled easy differentiation between subseptate and bicornuate uteri.

Abortion, Habitual↗
PubMed1995

Circadian variation in uterine artery blood flow indices during the follicular phase of the menstrual cycle.

We investigated for the presence of circadian variation in uterine artery blood flow indices during the late follicular phase of the menstrual cycle. Twenty women with regular menstrual cycles underwent transvaginal color Doppler assessment of blood flow in the uterine arteries on two occasions precisely 12 h apart on the same day in the follicular phase. Ultrasound examinations were performed between 06.00 and 10.00 and repeated between 18.00 and 22.00. Indices of uterine artery blood flow included the pulsatility index (PI) and the time-averaged maximum velocity (TAMX). The changes in PI and TAMX were related to variations in serum concentrations of estradiol and luteinizing hormone (LH). We noted a significantly higher PI and lower TAMX in the evening compared to the morning values, p < 0.001 and p = 0.01, respectively. There was no significant change in estradiol or LH concentrations between morning and evening (p > 0.05). There appears to be a circadian rhythm in uterine artery blood flow occurring independently of these hormonal parameters. The circadian changes in PI and TAMX may be larger than the previously described effects of hormones on these parameters. The accurate interpretation of uterine artery blood flow indices should take these time-related fluctuations into account.

Adult↗
PubMed1995

Changes observed in Doppler studies of the fetal circulation in pregnancies complicated by pre-eclampsia or the delivery of a small-for-gestational-age baby. I. Cross-sectional analysis.

The aim of this study was to compare changes in Doppler ultrasound studies of the fetal circulation in normal pregnancies with a group of pregnancies complicated by proteinuric pregnancy-induced hypertension (PPIH), delivery of a small-for-gestational-age (SGA) baby, or both. A total of 167 uncomplicated pregnancies with a term delivery of an appropriately grown baby (AGA) were used to define the normal range. Altogether, 123 high-risk pregnancies with a known outcome constituted the study group. A color duplex ultrasound machine was used to perform biometry and fetal Doppler studies. Measurements obtained from the fetal circulation included the umbilical artery (UA) pulsatility index (PI), the middle cerebral artery (MCA) PI and time-averaged velocity (TAV), the thoracic aorta (AO) PI and TAV. In addition, the ratio between the MCA PI and UA PI, the MCA PI and the AO PI, and the product of the MCA PI and AO TAV were used in the analysis. A total of 105 pregnancies had a complicated outcome. They were divided into three categories: PPIH only (pregnancies complicated by PPIH with the delivery of an AGA fetus, n = 17), SGA only (delivery of an SGA baby, with no evidence of PPIH, n = 55), and PPIH + SGA (pregnancies complicated by pre-eclampsia and delivery of an SGA baby, n = 37). The PPIH + SGA group represented true clinical intrauterine growth retardation. Cross-sectional reference ranges were created using the observations from the normal group. z-scores (standard deviation from the mean of the normal range) of the last observations made before delivery were calculated for each of the vessel velocimetry measurements and ratios. The statistical significance of z-score values was calculated using analysis of variance. The MCA and UA PI values showed the greatest deviation for any single-vessel parameter. The ratios of fetal Doppler indices (MCA/UA PI ratio, MCA/AO PI ratio and the MCA PI/AO TAV index) demonstrated greater deviation from normal than any individual vessel. The UA PI z-score for PPIH+SGA delivering < 34 weeks gestation (2.92) was significantly greater than the z-score for PPIH+SGA delivering > or = 34 weeks (1.20, p < 0.05). Fetal Doppler indices, in particular ratios that include measurements obtained from the cerebral circulation, help in the recognition of the small fetus that is growth-retarded. At term, evidence of fetal hemodynamic redistribution may exist in the presence of a normal umbilical artery PI. Fetal Doppler indices provide information that is not readily obtained from more conventional tests of fetal well-being.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1995

Endometrial thickness, morphology, vascular penetration and velocimetry in predicting implantation in an in vitro fertilization program.

A total of 96 women undergoing in vitro fertilization (IVF) treatment were studied on the day of human chorionic gonadotropin (hCG) administration by transvaginal ultrasonography with color and pulsed Doppler ultrasound. We assessed endometrial thickness, endometrial morphology, presence or absence of subendometrial or intraendometrial color flow, intraendometrial vascular penetration and subendometrial blood flow velocimetry on the day of hCG administration and related the results to pregnancy rates. The overall pregnancy rate was 32.3% (31/96) and there was no significant difference between the pregnant and non-pregnant groups with regard to endometrial thickness, subendometrial peak systolic blood flow velocity (Vmax) or subendometrial pulsatility index (PI). The pregnancy rates based on endometrial morphology were not significantly different, being 17.6% (3/17), 33.3% (2/6) and 35.6% (26/73) for types A (hyperechoic), B (isoechoic) and C (triple-line) endometria, respectively. In eight (8.3%) patients, subendometrial color flow and intraendometrial vascularization were not detected. This absence of blood flow was associated with failure of implantation (p < 0.05). The pregnancy rates related to the zones of vascular penetration into the subendometrial and endometrial regions were: 26.7% (4/15) for Zone 1 (subendometrial zone), 36.4% (16/44) for Zone 2 (outer hyperechogenic zone) and 37.9% (11/29) for Zone 3 (inner hypoechogenic zone), and were not significantly different. Of cycles with type A endometrium, 23.5% (4/17) had absent subendometrial color, which was greater than the frequency of absent color in the type C endometrium (4.1%, p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Coelomic fluid chorionic gonadotrophin and protein concentrations in normal and complicated first trimester human pregnancies.

Coelomic fluid and maternal serum samples were collected from 43 normal pregnancies and 18 missed abortions between 7 and 12 weeks of gestation. The samples were analysed for the concentrations of intact human chorionic gonadotrophin (HCG), free alpha HCG, free beta HCG and total protein. The relationships between the biological findings and the ultrasound and pathological features were assessed by regression analysis. In normal pregnancies, intact HCG, free alpha HCG and free beta HCG concentrations were respectively 1.3, 185 and 33 times higher in coelomic fluid than in maternal serum. The coelomic concentrations of intact HCG and free alpha HCG decreased significantly with advancing gestation. No relationship was found between coelomic fluid and maternal serum concentrations of the different variables. These findings suggest that in normal pregnancies, the concentration of HCG in the coelomic fluid, as in maternal serum, is mainly influenced by cytotrophoblastic differentiation and that the metabolic clearance of HCG molecules is slower in the coelomic cavity than in maternal serum. In missed abortions, the serum concentrations of intact HCG, alpha HCG and free beta HCG and the coelomic concentration of total protein were significantly lower than in normal pregnancies. In three out of nine anembryonic pregnancies diagnosed by ultrasound, embryonic remnants were present at histological examination. The coelomic concentration of total protein was extremely low in all missed abortions with advanced trophoblastic necrosis whereas the HCG concentration was low when embryonic remnants were absent. These findings support the concept that embryonic and placental development are closely related in the first trimester of human pregnancy, placental biological functions persisting only for a limited period of time after embryonic demise.

Abortion, Missed↗
PubMed1995

Luteinized unruptured follicle: morphology, endocrine function and blood flow changes during the menstrual cycle.

A case of spontaneous luteinized unruptured follicle syndrome is presented with full documentation of hormonal, morphological and haemodynamic changes. Changes in uterine blood flow were also noted. Growth of the leading follicle was slow during the follicular phase of the cycle. After the luteinizing hormone (LH) surge, growth of the follicle was more rapid. Concurrently, the follicle developed internal echogenicity with ultrasonic evidence of separation of the granulosa cell layer. The follicle was no longer visible 144 and 132 h after the LH rise and peak respectively. There was no primary progesterone rise associated with either the LH rise or peak, but a secondary progesterone rise occurred 42 h after the onset of the LH surge. Peri-follicular blood flow velocity was detected for the first time on cycle day 5 and appeared to rise after the onset of the LH surge. Peri-follicular blood flow velocity appeared to reduce after the LH surge to values associated with the follicular phase. These observations are consistent with an association of a primary granulosa cell defect with luteinized unruptured follicle syndrome which would account for the initial slow follicular growth, absent primary progesterone rise and reduction in blood flow in the wall of the follicle after the LH surge.

Adult↗
PubMed1995

Cell adhesion molecules on the oocyte and preimplantation human embryo.

The presence of cell adhesion molecules on human oocytes, early embryos, and pre-hatched blastocysts was examined by indirect immunofluorescence and compared to the distribution found on first trimester villous placenta with the same antibodies. Six integrin subunits (alpha 3, alpha V, beta 1, beta 3, beta 4, beta 5) were observed consistently throughout preimplantation development. Evidence was also obtained for the presence of integrin subunits alpha 2, alpha 4, alpha L, beta 2, and beta 7 on a small number of oocytes. A more restricted developmental analysis of E-cadherin, ICAM-1, NCAM, and VCAM-1 demonstrated that these cell adhesion molecules are also present on oocytes and early embryos. L-selectin was detected on oocytes but was not found on 8-cell embryos. The oocyte and early blastomeres have complex surfaces in which the integrin and CAM families are represented.

Blastocyst↗
PubMed1995

Induced tolerance and chimaerism in human fetuses using coelocentesis: a medical opportunity to avert genetic disease?

Coelocentesis offers a new opportunity for gaining access to the coelomic cavity of human embryos from 28 days post-fertilization (42 days menstrual age). With this technique, cells can be extracted from the cavity for the genetic typing of embryos in early pregnancy. Coelocentesis may also offer a unique opportunity of inducing tolerance to foreign grafts and chimaerism in these human embryos by replacing donor cells into the coelomic cavity. This cavity appears to be closely associated with the fetal haemopoietic system. The optimal age to inject stem cells designed to produce chimaerism may be at 5-6 weeks embryonic age, and these grafted cells may induce tolerance later in gestation. Two successive coelocenteses would be needed, the first to extract fetal cells to type the fetus, and a second within a few days to inject the donor cells into the coelomic cavity. Alternatively, non-invasive methods of diagnosis such as lower uterine pole extramembranous sampling of fetal trophoblast, or the extraction of fetal cells from maternal blood, could be combined with coelocentesis. If tolerance and chimaerism can be established, repeated tissue grafts could be carried out during fetal life and after birth, so that disorders caused by single or multiple gene defects in the haemopoietic system and other organs may be corrected.

Chimera↗