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Biomedical subjects

W Gibbons

Publications and source records attributed to W Gibbons.

18 recordsLinked to original sources
PubMed2001

Outcome of intracytoplasmic sperm injection in azoospermic patients: stressing the liaison between the urologist and reproductive medicine specialist.

OBJECTIVES: To analyze the outcome of intracytoplasmic sperm injection (ICSI) cycles in infertile couples in whom the main diagnosis of infertility was azoospermia of obstructive and nonobstructive origin. METHODS: Eighty-three consecutive ICSI cycles were carried out with retrieved testicular or epididymal spermatozoa, 60 cycles in 32 patients with obstructive azoospermia and 23 cycles in 12 patients with nonobstructive azoospermia. Fifty-four testicular biopsies (testicular sperm extraction) and 18 epididymal aspirations (microepididymal sperm aspiration) were performed.Results. Motile spermatozoa were recovered in 65 cycles (90.3%). In another 3 (4.2%), nonmotile spermatozoa were retrieved. In 4 patients (5.5%), sperm could not be recovered. In 11 cycles, frozen sperm from a previous procedure were used. A significantly lower fertilization rate (64% versus 73%, P = 0.02), clinical pregnancy rate (13% versus 47%, P <0.001), and good embryo quality rates (35% versus 56%, P = 0.009) were observed in patients with nonobstructive azoospermia. In patients with obstructive azoospermia, no significant differences were observed when the outcome was analyzed on the basis of the sperm origin (ie, from testicular sperm extraction or microepididymal sperm aspiration). CONCLUSIONS: When combining testicular sperm extraction or microepididymal sperm aspiration with ICSI in patients with obstructive azoospermia, the results in terms of fertilization, implantation, and pregnancy rates were similar to those found in patients with nonazoospermic obstruction who underwent ICSI with ejaculated sperm. Patients with nonobstructive azoospermia had lower fertilization, embryo quality, and pregnancy rates than did those with obstructive azoospermia, probably because of severe defects in spermatogenesis, leading to poor gamete quality. The urologist and reproductive endocrinologist now have an excellent therapeutic option to offer men with previously intractable infertility.

Adult↗
PubMed2000

Evaluation of outpatient hysteroscopy, saline infusion hysterosonography, and hysterosalpingography in infertile women: a prospective, randomized study.

OBJECTIVE: To compare the diagnostic accuracy, pain scores, and procedure length of outpatient hysteroscopy (OHS), hysterosalpingography (HSG), and saline infusion hysterosonography (SIS) for evaluation of the uterine cavity of infertile women. DESIGN: Prospective, randomized, investigator-blind study. SETTING: Tertiary infertility clinic. PATIENT(S): Forty-six consecutive infertile women. INTERVENTION(S): Outpatient HSG, OHS, and SIS, followed by operative hysteroscopy (HS). MAIN OUTCOME MEASURE(S): Uterine abnormalities, procedure length, and subjective pain. RESULT(S): Fifty-nine percent of infertile subjects were found to have an abnormality on at least one of three outpatient uterine evaluations. When compared with the case of definitive operative HS, 60% of abnormalities were correctly classified by HSG, 72% by OHS, and 52% by SIS (P: NS). When comparing all combinations of 2 outpatient screening tests to operative hysteroscopy, 68% were correctly classified by HSG/OHS, 58% by HSG/SIS, and 64% by OHS/SIS (P: NS). The average time length for the OHS was 9.1 min., which was significantly greater than for both HSG (average, 5.3 min) and SIS (average, 6.1 min.) (P<.0001 for both). HSG and SIS were not statistically different regarding procedure time length. The average pain score (0-10) for SIS was 2.7, compared with 5.8 and 5.3 for HSG and OHS, respectively. Both HSG and OHS mean pain scores were significantly greater than the SIS mean. CONCLUSION(S): OHS, SIS, and HSG were statistically equivalent regarding evaluation of uterine cavity pathology in infertile women.

Adult↗
PubMed2000

Human embryos derived from in vitro and in vivo matured oocytes: analysis for chromosomal abnormalities and nuclear morphology.

PURPOSE: To determine whether embryos resulting from oocytes matured in vitro have a higher incidence of nuclear and/or genetic abnormalities compared to embryos resulting from oocytes matured in vivo. METHODS: Fluorescence in situ hybridization analysis for chromosomes X, Y, and 18 was used to compare the rates of aneuploidy, mosaicism, and nuclear abnormalities in embryos derived from oocytes that were prophase I at aspiration (immature group) to that observed in embryos resulting from oocytes that were metaphase I or II at aspiration (mature group). RESULTS: Based on nuclear morphology, significantly more embryos in the mature group (23%) were classified as normal compared to embryos in the immature group (3%). No difference was found in the rate of aneuploidy or in the incidence of mosaicism involving these chromosomes. CONCLUSIONS: These findings suggest that few embryos derived from prophase I oocytes collected following ovarian stimulation are morphologically normal.

Aneuploidy↗
PubMed1994

Radioprotection of hematopoietic stem cells by interleukin-1.

Radioprotective agents such as interleukin-1 (IL-1) and tumor necrosis factor (TNF-alpha), when given prior to irradiation, protect animals from radiation damage. However, in vivo administration of these cytokines does not allow one to determine whether the protective effects act directly on the hematopoietic system. In the present study, we subjected male bone marrow cells to in vitro treatment with IL-1 prior to irradiation and bone marrow transplantation. We found that male bone marrow cells pretreated with IL-1 prior to irradiation increased the survival of irradiated female recipient mice when compared with nontreated irradiated marrow cells. In addition, irradiated female recipients that received IL-1-pretreated male donor bone marrow cells displayed an increased presence of male donor cells in their bone marrow, spleen, and thymus for up to 3 months posttransplant. Furthermore, serial transplantation studies revealed that male cells could only be detected in tertiary female recipients who received bone marrow from mice transplanted with IL-1-treated cells. These results indicate that IL-1 pretreatment protects both short-term and long-term repopulating stem cells from an irradiation insult and that these cells are capable of reconstituting the myeloid and lymphoid organs of recipient mice.

Animals↗
PubMed1992

Exertional dyspnea and ventilation in hyperthyroidism.

Dyspnea is recognized to be an important feature in patients with hyperthyroidism at rest and during exercise. However, its etiology is not well-understood. Since dyspnea is thought to be related to the perception of excessive ventilatory effort, we explored the possibility that dyspnea in these patients might be related to an inappropriate ventilatory response to the increased metabolic rate. We studied 11 hyperthyroid patients and 11 age- and sex-matched controls, performing spirometry, lung volumes, mouth pressure measurements, and incremental exercise test. Central drive was estimated by measuring P0.1 and sensation of dyspnea by the Borg scale. We found that hyperthyroid patients (1) have higher ventilation than normal subjects during exercise even when corrected for VCO2 levels; (2) this increased ventilation is secondary to increased central drive which is correlated to the T3ria level (r = 0.85, p less than 0.01); (3) hyperthyroid patients are more dyspneic than controls; and (4) the increased drive can be normalized by beta-blockade. We conclude that the main ventilatory abnormality in hyperthyroid patients is an inappropriate increase in respiratory drive, possibly secondary to increased adrenergic stimulation.

Adult↗
PubMed1991

Conformational analysis of two cyclic disulfide peptides.

Complete nmr and CD studies of two cyclic tetrapeptides with disulfide bonds, Ac-L-Pen-L-Pro-D-Val-L-Cys-NH2 (1) and Ac-L-Cys-L-Pro-D-Val-L-Cys-NH2 (2) bonds have been carried out in different solvents to investigate the formation and stabilization of beta-turn structures and to determine the stereochemistry of the disulfide linkage. Both peptides have three-dimensional structures with a type II beta-turn, as derived from quantitative nuclear Overhauser effect data. The combined use of CD and nmr indicates that the dihedral angle of the disulfide bridge is different in the two peptides, although the chirality is maintained.

Amino Acid Sequence↗
PubMed1989

Determinants of weaning and survival among patients with COPD who require mechanical ventilation for acute respiratory failure.

The decision to institute MV in patients with COPD and ARF is difficult because the risk of complications is high and the long-term prognosis is poor. We reviewed our experience with 95 COPD patients with ARF requiring MV. Fifty-five patients required MV for more than two weeks, 72 were weaned successfully, and 59 died within one year of follow-up. Survival was associated with premorbid level of activity (p less than .001), FEV1 (p less than .01), serum albumin level (p less than .05), and severity of dyspnea (p less than .01). Cor pulmonale on ECG, premorbid hypercarbia, and history of left ventricular failure were also more common among those who died. Weaning from MV was associated with premorbid level of activity (p less than .001), FEV1 (p less than .001), albumin level (p less than .05), and negative inspiratory pressure (p less than .001) and respiratory rate during T-piece trial (p less than .01). The duration of intubation was associated only with premorbid level of activity (p less than .01). Predictive models for the weaning success and the one-year survival were developed.

Actuarial Analysis↗
PubMed1988

A genetic analysis of suppressors of the PF10 mutation in Chlamydomonas reinhardtii.

A mutation at the PF10 locus of the unicellular green alga Chlamydomonas reinhardtii leads to abnormal cell motility. The asymmetric form of the ciliary beat stroke characteristic of wild-type flagella is modified by this mutation to a nearly symmetric beat. We report here that this abnormal motility is a conditional phenotype that depends on light intensity. In the absence of light or under low light intensities, the motility is more severely impaired than at higher light intensities. By UV mutagenesis we obtained 11 intragenic and 70 extragenic strains that show reversion of the pf10 motility phenotype observed in low light. The intragenic events reverted the motility phenotype of the pf10 mutation completely. The extragenic events define at least seven suppressor loci; these map to linkage groups IV, VII, IX, XI, XII and XVII. Suppressor mutations at two of the seven loci (LIS1 and LIS2) require light for their suppressor activity. Forty-eight of the 70 extragenic suppressors were examined in heterozygous diploid cells; 47 of these mutants were recessive to the wild-type allele and one mutant (bop5-1) was dominant to the wild-type allele. Complementation analysis of the 47 recessive mutants showed unusual patterns. Most mutants within a recombinationally defined group failed to complement one another, although there were pairs that showed intra-allelic complementation. Additionally, some of the mutants at each recombinationally defined locus failed to complement mutants at other loci. They define dominant enhancers of one another.

Chlamydomonas↗
PubMed1988

Optimization of respiratory muscle relaxation during mechanical ventilation.

The authors calculated the active work of inspiration (Wp) and the inspiratory muscle pressure-time product (integral of Pmus.dt) in seven patients undergoing mechanical ventilation (MV). This was done by comparing the areas under the inflation pressure-volume and inflation pressure-time curves generated when the patient was contributing to the work of ventilation with those following sedation, when inspiratory muscle activity was absent (defined as absence of diaphragmatic EMG activity and of palpable accessory muscle contraction). Inspiratory muscle inactivity could be predicted by the observation of a smooth rise in inflation pressure that was highly reproducible from breath to breath. Relaxation was present without sedation during MV in the control mode with inspiratory flow rates above 65 1/min. In the assist mode (AMV), both Wp and integral of Pmus.dt were significantly (P less than 0.05) greater than in the control (CMV) mode. Reducing trigger sensitivity during AMV further increased Wp and integral of Pmus.dt (P less than 0.05). During AMV and CMV Wp and integral of Pmus.dt decreased with increasing rate of inspiratory flow delivered by the ventilator. With AMV at low trigger sensitivity and low flow rates, Wp approached 65% of the total inspiratory work. The authors conclude that inspiratory muscle activity can be substantial during MV, particularly during AMV at low trigger sensitivity and flow. Monitoring of inflation pressure is a simple means of determining the degree of inspiratory muscle rest during MV.

Humans↗
PubMed1988

Management of ovarian hyperstimulation syndrome with chlorpheniramine maleate, mannitol, and invasive hemodynamic monitoring.

Ovarian hyperstimulation syndrome due to exogenous gonadotropin administration is life-threatening in its most severe form. Profound fluid shifts may occur, with concomitant cardiovascular changes. We present a case of severe ovarian hyperstimulation syndrome managed with chlorpheniramine maleate (previously shown to be effective in animal models) and invasive hemodynamic monitoring. Mannitol and albumin infusions were also used to maintain urine output and intravascular volume.

Adult↗
PubMed1987

Outbreak of diarrhea in a day care center with spread to household members: the role of Cryptosporidium.

From August 1 to November 1, 1984, 80 (43%) of 186 children attending a day care center (DCC) in Tulsa, OK, had diarrhea. Seventy-one percent of children less than 3 years of age had diarrhea, compared with 17% of children 3 to 8 years old. The duration of illness was 1 to 42 days (median, 8 days). At least one stool specimen was obtained from 142 (76%) of the 186 children. Children who had had diarrhea were more likely to have a specimen positive for Cryptosporidium (27 of 77, 35%) than were children who had not had diarrhea (8 of 65, 12%) (P less than 0.01). The presence of Giardia, Campylobacter, enterovirus, or rotavirus was not statistically associated with diarrhea. These results suggest Cryptosporidium as a causative agent. The secondary attack rate for diarrhea among household contacts exposed to DCC children with diarrhea was 77 of 204 (38%) compared with 25 of 273 (9%) for household contacts of children in the DCC who did not have diarrhea (P less than 0.001). Stool specimens were obtained from 79 household contacts. Six (23%) of 26 household members exposed to a Cryptosporidium-positive child had a stool specimen positive for Cryptosporidium, compared with 1 (2%) of 53 household contacts exposed to a DCC child whose stool specimen was negative for Cryptosporidium (P less than 0.01). The outbreak resolved within 2 weeks after cohorting children with diarrhea and stressing the importance of handwashing among staff and older children. cryptosporidium can cause outbreaks of diarrhea in DCC settings, can be spread within households and may be more common than previously recognized among DCC attendees and their household members.

Child↗
PubMed1987

In-vitro fertilization as therapy for male-factor infertility.

In conclusion, IVF is a viable option for the couple with infertility secondary to reduced semen quality unresponsive to routine treatment. The increase in sperm/egg interaction allowed by IVF is rewarded with a pregnancy rate that is not statistically different from that for the overall IVF population. In our last 100 consecutive cycles, after altering our ovulation induction method to produce more oocytes per retrieval attempt, our overall clinical pregnancy rate was 25 per cent. The pregnancy rate for the male-factor patients during this same time period was 20 per cent, a rate similar to the monthly fecundability rate of a normal population of fertile couples. Further, in our hands the sperm penetration assay is of great help in predicting the ability of a human sperm to fertilize a human oocyte.

Female↗
PubMed1980

Patient cooperation: a determinant of perinatal outcome in the pregnant diabetic.

From 1974 through 1978, 59 insulin-dependent diabetic patients were treated in a university-affiliated general hospital. They were managed primarily as outpatients with hospitalization for regaining glucose control and/or in the treatment of obstetric complications. In 1976 a special clinic for pregnant diabetic patients was established. The 26 patients treated during the clinic's first two years are compared to 33 treated in the preceding 2 1/2 years. The significant difference between the two groups was the improvement in the number of patients whose cooperation was good, 67% to 85% (p less than 0.05), and the reduction of perinatal morbidity and mortality. The perinatal mortality rate was 18% and 8% in the preclinic group (group I) and the clinic group (group II), respectively. The combined perinatal morbidity and mortality was reduced from 36% to 15%, respectively, in groups I and II (p less than 0.01). A constant rate of 3.2% perinatal mortality was observed in the obstetric population during the study period.

Blood Glucose↗
PubMedDate not supplied

Relationship between the results of sperm analysis and GIFT.

In vitro fertilization (IVF) and GIFT have been proposed as therapeutic approaches in infertile couples where a significant male factor is present. To date, few published data are available relating the success rate of GIFT to the severity of the male factor. In this report the results of the first 172 GIFT cases were analyzed. The overall pregnancy rate was 18.0%. The relationship between the occurrence of pregnancy and sperm count (millions/ml), total sperm count (millions/ejaculate), % motility, motile sperm count (millions/ml) and total motile sperm count (millions/ejaculate) were examined. Significant direct correlations were observed between the clinical pregnancy rate and sperm count, total sperm count, motile sperm count and total motile sperm count. Motile sperm count and total motile sperm count had the best correlations with clinical pregnancy rates, which were over 24.0% in groups with motile sperm counts exceeding 40 X 10(6) cells/ml or total motile sperm counts greater than 100 X 10(6)/ejaculate. The clinical pregnancy rates were 12.5% and 7.7%, respectively, for groups with motile sperm counts under 10 X 10(6)/ml and total motile sperm counts below 25 X 10(6)/ejaculate. No correlation was found between percent motile cells and pregnancy rate. Results of the sperm penetration assay using zona-free hamster eggs were available in a subpopulation of 27 patients. No significant correlation between this sperm penetration assay and pregnancy rate could be demonstrated. The incidence of chemical pregnancy showed a significant negative correlation with the total motile sperm count, indicating a higher incidence of early pregnancy wastage in cases of oligozoospermia.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗