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Biomedical subjects

P Curtis

Publications and source records attributed to P Curtis.

At least 19 recordsLinked to original sources
PubMed1992

Fertilization and embryonic development of human oocytes after cooling.

Injury to living cells resulting from rapid cooling to temperatures at or near 0 degrees C has long been recognized, and the phenomenon, which is termed 'cold shock', has been known to occur in some mammalian gametes. Although human embryos have been successfully stored at low temperatures, cryopreservation of the human oocyte is proving to be more difficult. Whether or not this lack of success is a direct result of cellular injury brought about by 'cold shock' is the purpose of the current investigation. Human oocytes were cooled, in the absence of cryoprotectants, at two different cooling rates (-3 degrees C/min and -1000+ degrees C/min) to a temperature of 0 degrees C and rewarmed prior to insemination. In both cases fertilization after cooling was similar to the rates achieved in a routine in-vitro fertilization and embryo transfer procedure. After cooling at -3 degrees C/min, the rate of fertilization was 19/22 (86%) and after cooling at -1000+ degrees C/min, 9/9 (100%), with non-cooled control rates of 62/87 (71%) and 35/50 (70%) respectively. Fertilized oocytes from both groups were successfully cultured for a further 24 h before termination of the experiment.

Cryopreservation↗
PubMed1992

Exposure to LHRH agonists in early pregnancy following the commencement of mid-luteal buserelin for IVF stimulation.

Exposure to buserelin in early pregnancy has been reported following its use in in-vitro fertilization treatment cycles. The number of reported cases is small. There are still no answers regarding embryotoxicity, and the need for luteal support is still unclear. A further six cases are reported here, five receiving luteal support and resulting in the delivery of healthy children, and one, without luteal support ending in a first trimester miscarriage. We propose that further data should be collected to allow adequate monitoring and follow-up of these pregnancies.

Abortion, Spontaneous↗
PubMed1992

The role of partial colpectomy in the management of persistent vaginal neoplasia after primary treatment.

OBJECTIVE: To describe and assess the technique of partial colpectomy for the treatment of persistent vaginal neoplasia. SETTING: Gynaecological oncology unit of a London teaching hospital. SUBJECTS: 12 women with persistent vaginal intraepithelial neoplasia (VAIN) following hysterectomy for cervical intraepithelial neoplasia (CIN) or for benign disease. TECHNIQUE: Partial colpectomy using a vaginal approach assisted by a Schuhardt incision to improve access. RESULTS: Assessment of patients between 9 and 99 (mean 55) months after partial colpectomy for VAIN showed no recurrence of disease in ten patients (83%). CONCLUSION: This technique of partial colpectomy is an effective procedure, associated with minimal morbidity which should be considered as primary treatment for patients suffering from persistent vaginal disease after hysterectomy or other procedures.

Adult↗
PubMed1992

Family physicians, chiropractors, and back pain.

In this article, major aspects of back care provided to patients by family physicians and chiropractors are reviewed, and the recent guidelines on spinal manipulation therapy are discussed. These guidelines should be useful for family physicians wishing to refer patients to chiropractors.

Attitude of Health Personnel↗
PubMed1991

Assessment of the relevance of zona pellucida antibodies in serum and cervical mucus in patients who have fertilization failure during in vitro fertilization.

OBJECTIVE: To assess whether antibodies to the zona pellucida can cause fertilization failure during in vitro fertilization (IVF). DESIGN: Two methods for detecting zona pellucida antibodies were used to assess 20 women undergoing IVF. Nine patients had failed fertilization during the treatment cycle. SETTING: Academic IVF department of a teaching hospital. PATIENTS: Infertile patients previously assessed as requiring IVF. INTERVENTIONS: Gonadotropin-releasing hormone analogue to achieve pituitary down regulation and human menopausal gonadotropin for superovulation. Transvaginal ultrasound directed oocyte recovery. Cervical mucus and serum samples were obtained. MAIN OUTCOME MEASURES: The presence of antizona pellucida antibodies in serum or cervical mucus in relation to fertilization. RESULTS: Seven of 20 patients had antizona antibodies in serum and 7 of 20 patients had antibodies in mucus. Only 1 patient had antibodies in both samples. No correlation between the presence of antibodies in either sample and failure of fertilization was found. CONCLUSION: Detection of antizona pellucida antibodies by the methods described have no role in the prediction of IVF.

Antibodies↗
PubMed1991

Evaluation of the risk of pelvic infection following transvaginal oocyte recovery.

The risk of introducing infection into the peritoneal cavity at the time of transvaginal ultrasound-guided recovery of oocytes in assisted reproduction techniques was assessed by culturing peritoneal fluid samples from 25 women with unexplained infertility. The samples were collected laparoscopically at the time of zygote intra-Fallopian transfer (ZIFT), 24-48 h after oocyte collection. High vaginal and endocervical specimens from 25 women treated by in-vitro fertilization (IVF) and transcervical embryo transfer were cultured for comparison. The peritoneal cultures were negative in all but one patient. High vaginal swabs grew Candida albicans in three cases and endocervical specimens were all negative. Seven and three pregnancies occurred in the ZIFT and IVF groups respectively. No pelvic damage was noted at laparoscopy in those women who had had previous treatment cycles with transvaginal oocyte recovery. This method of oocyte recovery, using prophylactic metronidazole and chlorhexidine for preoperative vaginal preparation, appears to be safe for treatment of women with no previous pelvic damage.

Adult↗
PubMed1991

A critical review of labor and birth care. Obstetrical Interest Group of the North American Primary Care Research Group.

A critical review of the literature regarding important aspects of labor and delivery was conducted by members of the Obstetrical Interest Group of the North American Primary Care Research Group using computerized searches, personal communication, and literature exchange between group members. Each written topic summary was carefully reviewed by a second group member, and a consensus was reached regarding conclusions and recommendations by the group. The topics include family involvement, comfort measures, fetal heart rate monitoring, labor augmentation, birth positions, and episiotomies. Each topic summary is preceded by conclusions and recommendations given in the order of least invasive to most invasive of the woman in labor. The strength of these conclusions and recommendations is based on the amount and type of supportive data in the literature and is indicated by one to three stars preceding that statement. One-star conclusions are not well supported in the literature but reflect a family practice style and were reached through consensus from the group. Three-star conclusions are supported by data from clinical trials.

Delivery, Obstetric↗
PubMed1990

The procedural skills of medical students: expectations and experiences.

The procedural skills that medical students should learn were identified by a survey of faculty and residents at the University of North Carolina at Chapel Hill School of Medicine in 1985. Those who responded indicated that it was important for students to have exposure to all 52 procedures listed on the questionnaire. Only a small number of procedures were identified by 75% or more of those who responded as being important for students to perform with proficiency (11 procedures identified by the faculty, nine by the residents). On another questionnaire, the graduating medical students indicated that, for the most part, they had experience performing these important procedures. To ensure clinical competency, expectations regarding these skills should be communicated to students, faculty, and residents and, ideally, a system should be established to assess these skills.

Clinical Clerkship↗
PubMed1989

Physical and mechanical properties of anterior and posterior composite restorative materials.

The physical and mechanical properties of two photo-cured anterior filling materials and a photo-cured posterior filling material have been compared with those of a conventional-cure resin composite. The properties of these materials were found to be dependent on their matrix resin compositions, filler contents, and filler particle sizes. One material with a low (50%) inorganic filler content of small particle size (0.04 micron) was found to have a lower mechanical strength with significantly higher water sorption and solubility characteristics than more heavily filled materials. A new hybrid photo-cured anterior composite with a smaller filler particle size was found to have comparable sorption and solubility behavior but a tensile strength superior to that of a conventional-cure composite. The superior properties of the new photo-cured systems are thought to result from their hybrid composite structures and the smaller filler particle sizes.

Composite Resins↗
PubMed1989

The effects of gamma radiation on the properties of composite restorative resins.

The effects of gamma radiation at therapeutic dosage levels on the physical properties of three anterior (two light-cured and one autocure) composites and a light-cured posterior composite were studied. Gamma radiation had no effect on the autocured composite but had varied effects on the light-cured systems. The diametral tensile strength and dimensional stability were unaffected, water sorption and solubility were reduced but surface and bulk hardnesses were increased with the hardness increases linearly related to the radiation dosage. These effects may arise from continued polymerization of the air-inhibited surface layer and possibility of low molecular weight entities within the matrix. Overall, therapeutic levels of gamma radiation had no detrimental effects on the physical properties of the composite resins.

Adsorption↗
PubMed1989

The mouse carbonic anhydrase I gene contains two tissue-specific promoters.

We report the isolation and characterization of the mouse carbonic anhydrase I (CAI) gene. Direct RNA sequence analysis of the 5' nontranslated regions of CAI mRNA from mouse colon and mouse erythroleukemia cells demonstrated tissue specificity in the lengths and sequences of CAI transcripts. Analysis of several mouse CAI genomic clones showed that the transcripts arose from a single CAI gene with two tissue-specific promoters and eight exons. CAI transcripts in the colon were found to initiate just upstream of the erythroid exon 2 of the CAI gene region sequence. Erythroid transcripts originated from a novel promoter upstream of exon 1, which was located more than 10 but less than 250 kilobases upstream of exon 2. Erythroid exon 1 contained only a nontranslated sequence, which was spliced to exon 2 via a cryptic splice acceptor site located in the region that encoded the colon mRNA 5' nontranslated sequence. The remaining exon-intron junctions were conserved in comparison with those of the CAII and CAIII genes.

Animals↗