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Biomedical subjects

R Rawlins

Publications and source records attributed to R Rawlins.

At least 19 recordsLinked to original sources
PubMed2003

Life threatening haemorrhage after anterior needle aspiration of pneumothoraces. A role for lateral needle aspiration in emergency decompression of spontaneous pneumothorax.

Needle aspiration is a recognised emergency treatment of spontaneous pneumothorax and in the case of suspected tension is usually performed before chest radiography. Three cases are described of apparent life threatening haemorrhage after anterior aspiration in the second intercostal space, mid-clavicular line (2ICS MCL) requiring resuscitation, and transfer to a cardiothoracic unit. In these patients there was no evidence of haemothorax on initial presentation. Lateral needle aspiration, in the site recommended for chest drain insertion, the 5th intercostal space, anterior axillary line (5ICS ALL) is technically easy and may be a potentially safer option for decompressing pneumothoraces.

Adult↗
PubMed2001

Effects of dioxin, an environmental pollutant, on mouse blastocyst development and apoptosis.

OBJECTIVE: To evaluate the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin) on mouse embryo development and apoptosis. DESIGN: Controlled animal study. SETTING: Academic research environment. ANIMAL(S): Female mice (CB6F1) at 3 to 6 weeks of age and proven breeders (C578B46). INTERVENTION(S): Mouse embryos were obtained at the morula stage and cultured to the blastocyst stage in a pharmacologic dose of TCDD (3.1 microM) or a control medium. The morphology was assessed, and staining for apoptosis was performed. Immunohistochemistry for the presence of aromatic hydrocarbon receptor (AhR) was performed in another set of morula-stage embryos. MAIN OUTCOME MEASURE(S): The number of embryos developing from the morula to the blastocyst stage and number of apoptotic blastomeres in control vs. TCDD culture conditions. RESULT(S): No statistically significant differences were observed in the percentage of embryos reaching the blastocyst stage: 80.9% (115 of 142) in the TCDD-treated group, vs. 82.9% (121 of 146) in the control group. There was also no difference in the degree of apoptosis: 22.6 +/- 7.3% apoptotic cells (TCDD) vs. 25.3 +/- 9.7% (controls). Staining indicated the slight presence of aromatic hydrocarbon receptor in the morula-stage mouse embryos. CONCLUSION(S): TCDD at 3.1 microM did not alter the development of early mouse morula to blastocysts and did not significantly induce apoptosis in vitro.

Animals↗
PubMed2001

Intraluminal biopsy of a superior vena cava mass.

A number of methods have been devised for the biopsy of intracaval tumour masses but all risk damage to the cava and tumour dissemination. We report on a case in which the tumour mass was almost entirely within the superior vena cava and describe an 'endoscopic' technique for biopsy.

Biopsy↗
PubMed1997

The effect of the oviduct, uterine, and in vitro environments on zona thinning in the mouse embryo.

OBJECTIVE: To evaluate the impact of the oviduct, uterine, and in vitro environments on zona pellucida thinning in the mouse embryo. DESIGN: Female mice were stimulated with pregnant mare serum gonadotropin and mated and hCG injection. Unilateral oviduct ligation was performed on day 2 of gestation using the dorsal approach. The mice were divided into equal groups and killed on days 2, 3, 4, 5, and 10 of gestation. In vitro incubated embryos served as controls. Average daily zona thickness measurements were subjected to analysis of variance and paired Student's t-test. SETTING: The laboratory of the assisted reproductive program of Rush University Medical Center. MAIN OUTCOME MEASURE(S): Progressive daily decrease in average zona thickness. RESULT(S): Zona measurements of embryos flushed out of uterine horns, ligated oviducts, and in vitro incubation demonstrated statistically significant decreases in zona thickness, from 9.6 +/- 1.6 microns (day 3) to 6.0 +/- 0.8 microns (day 5), from 11.6 +/- 2.2 microns (day 2) to 6.0 +/- 1.6 microns (day 5), and from 11.1 +/- 2.0 microns (day 2) to 6.0 +/- 1.6 microns (day 5), respectively. There were no differences in average zona thickness for embryos in the same cell stage and same protocol day in all three locations. CONCLUSION(S): Zona thinning seems to be induced primarily by the dividing embryo before implantation. A substantial tubal and uterine contribution to zona thinning was not detected in this mouse embryo model.

Animals↗
PubMed1997

African American teen mothers' perceptions of parenting.

The purpose of this study was to describe the childbearing African American teens' perceptions of parenting based on their own experiences. Focus group discussions were held with 17 teens in their school setting for 50 minutes each week. Group discussions were audiotaped, tapes were transcribed, and then analyzed for common themes. The unmarried teens ranged in age from 15 to 18 years. Findings indicated that the teens depended on grandmothers to provide child care and for information about parenting. The teens identified parenting problems including crying, discipline, and conflicts dealing with grandmothers and the child's father. Teens wanted more information about breastfeeding and minor childhood diseases. The researchers identified that teens lacked information about their children's growth and development and safety issues. Findings have implications for nurses who care for childbearing teens and their children; and those involved in planning and implementing parent education programs for African American teen mothers and their families. Further research is indicated with larger samples of African American teens; and to explore the context of family relationships in which teen mothers and grandmothers share parenting for the teens' children.

Adaptation, Psychological↗
PubMed1996

Sonographically monitored ovarian stimulation for assisted reproduction: a prospective, blind study.

OBJECTIVE: To assess prospectively the appropriateness of follicular sonography alone for monitoring ovarian stimulation and to compare it to ovarian monitoring with both follicular sonography and hormone level determinations. STUDY DESIGN: Prospective, blind, clinical study in which the investigator made cycle management decisions based on follicular sonography only. RESULTS: Follicular sonography alone predicted 88% of the decisions made by the combination of follicular sonography, luteinizing hormone (LH), estradiol (E2) and progesterone measurements. Follicular sonography was unable to predict abnormal E2 patterns in eight (8%) of the patients' scans. Follicular sonography did not detect three (3%) patients with a premature LH surge. CONCLUSION: Follicular sonograms alone performed during ovarian stimulation predicted 88% of cycle decisions. One could argue that hormone measurements could be either reduced or eliminated during ovarian stimulation for assisted reproductive technology and that follicular sonography only would be a cost-effective compromise. The effect of such simplified monitoring on pregnancy rates would require further prospective evaluation.

Female↗
PubMed1995

The paternal inheritance of the centrosome, the cell's microtubule-organizing center, in humans, and the implications for infertility.

Successful fertilization in humans, achieved when parental chromosomes intermix at first mitosis, requires centrosome restoration and microtubule-mediated motility. Imaging of inseminated human oocytes reveals that the sperm introduces the centrosome. The centrosome then nucleates the new microtubule assembly to form the sperm aster--a step essential for successful fertilization. Oocytes from some infertile patients failed to complete fertilization because of defects in uniting the sperm and egg nuclei, indicating that failure to properly effect the cytoplasmic motions uniting the nuclei results in human infertility. These discoveries have important implications for infertility diagnosis and managing reproduction.

Centrosome↗
PubMed1994

The relationship between total motile sperm count and the success of intrauterine insemination.

OBJECTIVES: To determine if the total motile sperm count is predictive of IUI success and to apply life-table analysis to a large database of IUI procedures. DESIGN: Contingency table and life-table analyses were used to analyze a large group of couples (n = 546) undergoing 1,205 cycles of therapeutic IUI with husband's sperm. SETTING: Clinical infertility practice at a medical school referral center. PATIENTS: Five hundred forty-six couples with varying etiologies of infertility. RESULTS: There was a trend toward an increasing percentage of conception with increasing total motile sperm count. Significance was reached when the total motile sperm count used for IUI exceeded 20 x 10(6). The cumulative pregnancy rate calculated from this data reached 52% after the sixth attempted cycle of IUI.

Adult↗
PubMed1992

Luteal phase support and severe ovarian hyperstimulation syndrome.

The incidence and statistical associations of the ovarian hyperstimulation syndrome (OHSS) were studied in 304 egg retrievals with gonadotrophin-releasing hormone agonist suppression, gonadotrophin administration and follicular aspiration. In addition to preserving corpus luteum function, the luteal phase administration of human chorionic gonadotrophin (HCG) was associated with a higher incidence of severe OHSS than was supplementation with progesterone alone (12 versus 0%, P less than 0.001). Severe OHSS occurred in 3.7% and 12% of retrievals without and with pregnancy respectively (P less than 0.01). Stepwise logistic regression showed that the occurrence of moderate or severe OHSS was statistically predicted by the log of the serum oestradiol on the day the initial HCG was given (P less than 0.0001), treatment with luteal phase HCG (P less than 0.0003), and fetal number (P less than 0.0079). In the late luteal phase of cycles without luteal HCG, the serum oestradiol concentration was one-tenth and the serum progesterone concentration was one-fifth of the luteal phase value with HCG support (P less than 0.001). Without luteal phase HCG, oestradiol was two-fold higher (P less than 0.001) and progesterone was 1.4-fold higher (P less than 0.005) in pregnant than in non-pregnant women. With luteal phase HCG, oestradiol was 1.4-fold higher in pregnant than in non-pregnant women (P less than 0.05), and progesterone was 1.7-fold higher (P less than 0.001). Oestradiol upper limits of 4400 and 14,700 pmol/l (1200 and 4000 pg/ml) for cycles with and without luteal phase HCG respectively correspond to approximately 5% risk of moderate or severe OHSS with a singleton pregnancy under these conditions.

Chorionic Gonadotropin↗
PubMed1988

Persistent ovarian cysts following administration of human menopausal and chorionic gonadotropins: an attenuated form of ovarian hyperstimulation syndrome.

Ovarian cysts persisting after the onset of menses were demonstrated by ultrasound (US) in 40 of 71 (56%) nonconception cycles following ovulation induction with human menopausal gonadotropins (hMG) and human chorionic gonadotropin (hCG). Persistent cysts were self-limited and all resolved spontaneously within two cycles. They developed more frequently during stimulation cycles with (1) higher mean pre-hCG serum estradiol (E2), (2) a greater number of medium and large follicles at peak pre-hCG E2, and (3) a larger leading follicle diameter at peak pre-hCG E2. Persistent ovarian cysts frequently occurred despite a peak pre-hCG E2 lower than 1000 pg/ml. Although ovarian enlargement in the presence of cysts exceeded 5 X 5 cm in 25% of cases, no patient developed clinical symptoms of ovarian hyperstimulation syndrome (OHSS). Repeated induction of ovulation with hMG/hCG in the presence of nonfunctional, persistent cysts resulted in pregnancies in 6 of 15 cases (40%). Asymptomatic persistent ovarian cysts frequently follow an hMG/hCG regimen and, when nonfunctional, are not a contraindication to repeated ovarian stimulation. Persistent ovarian cysts appear to be an attenuated form of OHSS.

Adult↗
PubMed1983

The role of carbon fibre as a flexor tendon substitute.

Experiments have been carried out on Rhesus monkeys to determine the effectiveness of carbon fibre as a flexor tendon substitute. Though the strength, flexibility and capacity to induce a neotendon make carbon fibre an ideal flexor tendon substitute, induction of fibrosis and accompanying increase in bulk of the implant resulted in failure.

Animals↗
PubMed1983

Comparison of static and dynamic repairs for ligamentous instability of the knee.

Twenty-three patients who have had a MacIntosh type of fasciodesis for anterolateral rotary instability of the knee have been studied. Overall 73% were improved by this procedure; of those whose only instability was when turning on the run, 90% improved. These results have been compared with a series of 51 patients who had a pes anserinus transfer for anteromedial instability (D'Arcy 1978). It is suggested that both static and dynamic reconstructions have a place in the management of knee instability resulting from anterior cruciate injury.

Adolescent↗