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Biomedical subjects

C E Pope

Publications and source records attributed to C E Pope.

At least 19 recordsLinked to original sources
PubMed1998

Development of embryos produced by intracytoplasmic sperm injection of cat oocytes.

Development of cat oocytes following intracytoplasmic sperm injection (ICSI) and in vitro fertilization (IVF) was compared in two experiments. Domestic cat donors (used as a model for wild felids) were treated with 150 IU equine chorionic gonadotrophin (eCG) on treatment day 1 or a total of 10-15 IU of follicle-stimulating hormone (FSH) over four days, followed by 100 IU human chorionic gonadotrophin (hCG) on day 5 and follicular aspiration 24-26 h later. A jaguarundi (Herpailurus yaguarondi) female was stimulated twice with FSH (20 IU) or eCG (300 IU) and hCG (250 or 300 IU) before oocyte recovery. After storage at 4 degrees C, domestic cat semen was washed and processed. For ICSI, denuded oocytes were each injected with an immobilised spermatozoon. IVF oocytes were co-incubated with 5 x 10(4) motile spermatozoa/0.5 ml for 4-6 h. Noncleaving oocytes were fixed and stained 24-28 h after injection or insemination. Presumptive zygotes were cultured before transfer on day 5 (experiment I only) or evaluation on day 7 (experiments I and II). In experiment I, fertilization frequency was 67.9% (72/106) and 58.1% (122/210) for IVF and ICSI oocytes, respectively (P > 0.05). Most noncleaving ICSI oocytes (71/88, 80.7%) at 24 h were at metaphase II, of which half (35/71, 49.3%) had an activated spermatozoon (n=4) or premature chromatin condensation (PCC, n=31) of the sperm head. All 69 day 7 IVF embryos developed to morulae (> 16-cells, 46.7%) or blastocysts (53.3%), and 59/63 (93.7%) ICSI embryos reached the morula (50.8%) or blastocyst (42.9%, P > 0.05) stage. Mean cell number in IVF and ICSI embryos was 136 and 116 (P > 0.05); morulae had 77 and 46 (P < 0.05) and blastocysts had 187 and 209 (P > 0.05) cells, respectively. After transfer of 10 or 11 day 5 ICSI morulae to each of four recipients, a total of three kittens were born to two dams at 66 or 67 days. Of 18 fair-to-good quality oocytes recovered from a jaguarundi on two occasions, 10 (55.6%) embryos were produced by ICSI with fresh (n=5) or frozen (n=5) conspecific spermatozoa, but no jaguarundi kittens were born after transfer of these embryos to domestic cat recipients. In experiment II, cleavage frequency following IVF (15/17, 88.2%) and ICSI (31/38, 81.6%) was higher (P < 0.05) than following sham ICSI (13/35, 37.1%). Mean cell number (27 cells) and blastocyst development (0%) on day 7 was lower (P < 0.05) in the sham ICSI group than in the ICSI group (45 cells, 15.6% blastocysts) which, in turn, was lower (P < 0.05) than the IVF group (94 cells, 46.7% blastocysts). We have demonstrated that ICSI can be applied successfully in domestic felids and suggest that the technique will effectively augment other biotechniques being developed for enhancing reproduction in endangered felids.

Animals↗
PubMed1998

Increased prevalence of gastroesophageal reflux in patients with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal interstitial lung disease (ILD) of unknown etiology. Introduction of acid into the respiratory tree can produce pulmonary fibrosis. Gastroesophageal reflux (GER) has previously been associated with several other respiratory conditions, including pneumonia, bronchitis, and asthma. To investigate prospectively the possible association of GER and IPF, 17 consecutive patients with biopsy-proven IPF and eight control patients with ILD other than IPF underwent dual-channel, ambulatory esophageal pH monitoring. Sixteen of 17 patients with IPF had abnormal distal and/or proximal esophageal acid exposure compared with four of eight control patients (p = 0.02). In the patients with IPF, mean percent distal total (13.6 versus 3.34, p = 0.006), distal upright (12.4 versus 5.1, p = 0.04), distal supine (14.7 versus 0.88, p = 0.02), and proximal supine (7.48 versus 0.24, p = 0.04) esophageal acid exposure times were significantly greater than those in control patients. Only four patients with IPF (25%) with increased acid exposure had typical reflux symptoms such as heartburn or regurgitation. Patients with IPF have a high prevalence of increased esophageal acid exposure, usually without typical GER symptoms. GER in these patients tends to occur at night and extend into the proximal esophagus. Acid reflux may be a contributing factor in the pathogenesis of IPF.

Adult↗
PubMed1997

The esophagus for the nonesophagologist.

The esophagus is a muscular tube (striated muscle at the top end, smooth muscle in the middle and lower portion) connecting the pharynx and the stomach. It is closed at both the top and bottom ends by specialized muscular sphincters. Deglutition begins as a programmed act, mediated by nerve fibers from the brain stem, and spreads aborally with a wave of inhibition preceding a moving-ring contraction that obliterates the lumen of the esophagus. Fluids fall by gravity in the upright position or are pushed down by the moving ring contraction when the subject is horizontal. There are several factors that prevent constant regurgitation of gastric contents back into the esophagus. Reflux of both gas and liquid does occur as a normal event. The esophagus usually performs its job description of transferring material from the pharynx to the stomach and venting the stomach when necessary with a minimum of fuss.

Deglutition↗
PubMed1997

Birth of a western lowland gorilla (Gorilla gorilla gorilla) following in vitro fertilization and embryo transfer.

A 21-year-old multiparous female exhibiting 31-41 day menstrual cycles was given hFSH (225 IU/day, Metrodin 75, from cycle day 3 through 9 (menses = day 1) and hCG (10,000 IU, Profasi, on day 10 to stimulate follicular development. At 35 h after hCG, under isoflurane (AErrane) anesthesia, follicles were aspirated by controlled suction under transvaginal ultrasound guidance. Metaphase II oocytes (n = 11) were placed in modified human tubal fluid (mHTF, 100 microliters) medium under oil at 37 degrees C in humidified 5% CO2. Frozen semen, collected by voluntary ejaculation, was thawed (70 degrees C H2O bath, 6 sec), diluted slowly, centrifuged, and resuspended in mHTF, and 160,000 motile spermatozoa/ml were added at 6 h after oocyte recovery. At 21 h postinsemination (p.i.) eight oocytes were at the two-cell stage, five were cryopreserved, and three were cultured to the six- to eight-cell stage in mHTF with granulosa cells before transcervical uterine transfer at 47 h p.i. using a Teflon catheter. Micronized progesterone (400 mg/d) was orally administered for 10 weeks posttransfer (p.t.). Ultrasound examination revealed a single fetus at 15 weeks p.t., and unassisted delivery of a live 1.37 kg female infant occurred at 29 weeks. Am. J. Primatol. 41:247-260, 1997.

Animals↗
PubMed1997

In vitro and in vivo development of embryos produced by in vitro maturation and in vitro fertilization of cat oocytes.

Cumulus-oocyte complexes of domestic cats were classified by morphology of ooplasm (A = good, B = fair, C = poor) and cultured for 24 h in TCM 199 with gonadotrophins (eCG, FSH, hCG or FSH/hCG). More of type A oocytes (52%) underwent in vitro maturation (IVM) than of type B (41%) or type C (17%). The gonadotrophin source did not affect frequency of IVM of type A (50-53%) or type B (38-44%) oocytes, but IVM of type C oocytes in hCG or FSH/hCG (27%/19%) was about double that in eCG or FSH alone (13%/10%). After IVF, frequency of cleavage for type A (54%), B (41%) and C (26%) oocytes was similar to the IVM frequency of the equivalent type. After 7 days, development to the morula (M) stage in vitro was similar among types (47-58%); however, higher percentages of type A and B oocytes developed to blastocysts (Bl), 31% and 29%, respectively, than of type C (15%). After transfer of day 5 (n = 70) or 6 (n = 32) M and Bl to day 4 or 5 recipients in trial 1 (n = 4) and 2 (n = 3), respectively, the three recipients in trial 2 gave birth to four live kittens. Development in vitro to M of IVM/IVF embryos frozen in propanediol plus sucrose during early cleavage was similar (64-69%) to that of cohort controls (64%), but Bl formation was reduced (13-17% versus 32%). Damage to the zona pellucida after plunging into liquid nitrogen at -30 degrees C was higher (11%) than that of the embryos cooled at 10 degrees C min-1 from -30 degrees C to -150 degrees C before storage (2%).

Animals↗
PubMed1996

The gastroesophageal flap valve: in vitro and in vivo observations.

BACKGROUND: This study was performed to confirm the presence and significance of a gastroesophageal flap valve. METHODS: The pressure gradient needed to induce reflux across the gastroesophageal junction and the level of a high-pressure zone were determined in 13 cadavers. On inspection in the cadavers, a mucosal flap valve at the entrance of the esophagus into the stomach was seen through a gastrostomy. This valve was deficient or absent in cadavers with a hiatal hernia. The valve was inspected in controls and in patients with reflux with a retroflexed endoscope. RESULTS: In cadavers with no hiatal hernia, a gradient across the gastroesophageal junction was present in nearly all cadavers. The gradient could be increased by surgically accentuating the valve without a concomitant rise in pressure in the high-pressure zone. Reduction of the hiatal hernia in the cadaver and anchoring of the gastroesophageal junction to the normal attachment to the preaortic fascia restored the valve and the gradient as seen through a gastrostomy. Control subjects had a prominent fold of tissue that extended 3 to 4 cm along the lesser curve of the stomach and tightly grasped the shaft of the endoscope. This was diminished or absent in reflux patients. Inspection of the valve in control subjects and subjects with reflux allowed for a grading system with Grades I through IV. This grading system was applied to a cohort of patients with and without reflux. The appearance of the flap valve was a better predictor of the presence or absence of reflux than was lower esophageal sphincter pressure. Endoscopic viewing of the valve during surgery can confirm that a competent valve has been reconstructed. CONCLUSIONS: Grading of the gastroesophageal valve is simple, reproducible, and offers useful information in the evaluation of patients with suspected reflux undergoing endoscopy.

Esophagogastric Junction↗
PubMed1993

In vitro fertilization in domestic and non-domestic cats including sequences of early nuclear events, development in vitro, cryopreservation and successful intra- and interspecies embryo transfer.

The domestic cat may be used as a model for developing assisted reproduction techniques including in vitro fertilization (IVF), embryo culture, cryopreservation and embryo transfer (ET) for application to threatened and endangered species of non-domestic cats. Interoestrous domestic cats were injected with a total of 1.0-6.0 mg follicle-stimulating hormone (FSH) daily for 4 days and with 100 iu human chorionic gonadotrophin (hCG) on day 5. Follicular oocytes recovered at 26 +/- 1 h after hCG were co-incubated for 4-6 h at 38 degrees C in 5% CO2 with spermatozoa (1-2 x 10(5) motile spermatozoa ml-1) collected by artificial vagina. To determine the timing of sperm penetration and early fertilization events in vitro, oocytes were fixed and examined at intervals from 0.5 to 10 h after sperm exposure. The penetration rate of metaphase II (MII) oocytes at 0.5-3 h was equivalent to that at 3-6 h (95 versus 96%). Second polar body extrusion, pronuclear formation and apposition were observed at 2, 6-8 and 10 h, respectively. Simple (Tyrode's) and complex (F-10, M-199 and CMRL-1066) culture media with 10% fetal calf serum were compared for their ability to support development to the morula or blastocyst stage during culture periods of 96-168 h after IVF. The average number of cells per embryo was similar (P > 0.05) in the various media at each interval except that CMRL-1066 reduced (P < 0.05) development at 96 h if it was used before the two-cell stage. In F-10, neither the presence of intact cumulus cells nor changing to fresh F-10 medium at 48 h affected development at 96 h. Blastocyst development at 168 h was similar in both F-10 (18%) and Tyrode's (26%). To determine developmental ability in vivo, IVF-derived embryos (n = 586) were transferred at 96 or 120 h to recipients (n = 49) that had undergone synchronous oocyte recovery as donors. The percentage of recipients producing kittens after transfer of embryos cultured for 96 or 120 h in F-10 was 31 and 25, respectively, compared with 55% of 120 h recipients receiving embryos cultured in M-199 or Tyrode's. Overall, more pregnancies occurred following transfer of > or = 12 embryos (11/26) than if < 12 embryos were transferred (6/23).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Medical and surgical treatment of nonallergic asthma associated with gastroesophageal reflux.

Patients presenting to a chest clinic because of adult-onset wheezing with no history of allergy had a 90 percent prevalence of gastroesophageal reflux, even though reflux symptoms were mild or absent. Ninety patients were randomly assigned to receive cimetidine or an identical placebo or to undergo antireflux surgery. During a six-month period, all groups improved clinically; the cimetidine and surgical groups improved more than the placebo group. The intake of pulmonary medication decreased significantly in both cimetidine and surgical groups. Pulmonary function test results improved in the cimetidine- and surgically treated patients; improvement was not statistically significant. At long-term follow-up, the surgical group maintained clinical improvement and decreased pulmonary medication intake, whereas the placebo group worsened. We conclude that gastroesophageal reflux can play a significant role in some patients with nonallergic pulmonary disease and that its treatment can improve pulmonary symptoms and objective measurements of pulmonary function.

Adult↗
PubMed1990

A baboon model for pregnancy-associated antigens (PAPP-A, PP5, PP14).

By radioimmunoassays established on human derived antigens, PAPP-A, PP5 and PP14 immunoreactivity was detected in placental extracts and blood of pregnant baboons. None of the serial dilution curves suggested parallelism between respective human and baboon samples. Based on slopes of regressed logit-log transformed binding data, PAPP-A demonstrated the greatest degree of interspecies immunological crossreactivity. PP14 showed the least conservation of antigenic determinants. Physicochemical characterization on heparin, zinc chelate and bovine thrombin affinity matrices could not distinguish human from baboon-derived antigens. As in the human, baboon PAPP-A and PP5 were not detected in blood of male or non-pregnant animals. PP14 was detected in baboon follicular fluid, and only PP5 immunoreactivity was measured in culture media of baboon embryos. Of the three antigens, PAPP-A was detected in pregnant baboons at about 61 days gestation, that is, 4 weeks before PP5 and PP14. With the exception of PP14 which attained peak concentration at 118 days of pregnancy, PAPP-A and PP5 concentrations were greatest at term. In conjunction with physicochemical and immunological criteria, these physiological kinetics clearly support a role for developing a baboon model to serve for further studies into feto-maternal signals, particularly antigens such as PAPP-A and PP5.

Animals↗
PubMed1989

Extended esophageal pH monitoring. An analysis of the literature and assessment of its role in the diagnosis and management of gastroesophageal reflux.

In this review article we examine several facets of extended pH monitoring of the esophagus. The different types of instrumentation and the technical difficulties of obtaining and interpreting tests are discussed. The wide variations among different laboratories in the duration and timing of pH monitoring sessions are summarized. We outline the problems in interpretation and reproducibility such as normal control values, criteria for separation of abnormal from normal subjects, correlation of pH events with symptoms and with esophageal injury. Comparison of extended with short-term monitoring of esophageal pH are drawn, as well as comparisons between results of extended monitoring and other tests of reflux. Cost considerations are listed. Finally, we present a proposed scheme for the use of extended pH monitoring as well as a cautious note about accepting extended pH monitoring as a routine clinical test at present.

Costs and Cost Analysis↗
PubMed1989

Respiratory complications of gastro-oesophageal reflux.

The association between pulmonary symptoms and gastro-oesophageal reflux has been well documented. However, it is still unclear whether abnormal pulmonary function causes increased reflux or reflux causes pulmonary symptoms. Available data suggest that both theories may be accurate. Clinical features of patients with reflux-induced pulmonary complications have been identified, although there are no specific methods for confirming this diagnosis. An algorithm that defines a series of diagnostic tests is presented. From the results of the small number of published clinical trials, it appears that antireflux surgery is the most effective and longest-lasting treatment for the correction of pulmonary symptoms.

Algorithms↗
PubMed1988

Effect of stress on oesophageal motor function in normal subjects and in patients with the irritable bowel syndrome.

Stress can modulate the motor function of the stomach, small bowel, and colon in healthy subjects, and of the small bowel and colon in patients with the irritable bowel syndrome (IBS). The effect of stress on oesophageal motility in eight healthy subjects and in eight IBS patients was studied, using two pressure transducers positioned just above the lower oesophageal sphincter and 5 cm proximally. Stressors were: a video arcade game, delayed audio feedback, and hand immersion in cold water. Each stress period was followed by five swallows of water. Frequency and amplitude of oesophageal contractions and the number of simultaneous and multipeaked contractions were manually counted for each stress period and compared to the preceding rest period. Frequency of contractions (per minute) tended to decrease during stress periods, but achieved significance only with the video arcade game in the control group (2.0 (0.6) v 1.2 (0.4); p less than 0.01). No other trend was evident in either control or IBS patients. No abnormalities of oesophageal body function were recorded in IBS patients either in basal conditions, or under stress. Unlike the more complex motor programmes elsewhere in the gut, the preprogrammed nature of oesophageal peristalsis is not modulated by stress.

Adult↗
PubMed1986

Cryopreservation and transfer of baboon embryos.

The feasibility of modifying bovine cryopreservation methods for use with baboon embryos was evaluated. Twenty-six baboon embryos at the eight-cell to blastocyst stage of development were transferred after being frozen using glycerol as cryoprotectant. Either a two-step fast of a controlled linear temperature depression was achieved to -40 degrees C, followed by plunging into liquid nitrogen. After thawing, embryos were rehydrated in medium containing sucrose (0.5 to 1.0 M) using various methods of glycerol dilution. Embryos were transferred nonsurgically to anesthetized recipient baboons. Two term pregnancies resulted from six embryos frozen using the controlled linear cooling method and rehydrated by dropwise dilution of the sucrose (0.8 M) medium. Later cell stages had a greater morphological integrity postthaw than did earlier developmental stages, and embryos frozen by the linear cooling-rate method had less cell damage than those frozen by the fast method.

Animals↗
PubMed1986

Electromyography of human oesophageal smooth muscle.

The aim was to study whether electromyography (EMG) activity is synchronous with oesophageal motor activity as assessed by manometry from the same oesophageal site. Patients with different motor disorders of the oesophagus and control subjects were investigated. EMG recordings were made by means of a suction capsule with silver/silver chloride spike electrodes. Slow EMG waves synchronous with respiration were recorded from the lower oesophageal sphincter and intermittently from the body of the oesophagus. Edrophonium increased spike discharges; atropine diminished or abolished spike discharges after swallowing. Swallowing caused a burst of spiking activity which began immediately after deglutition. Continuous sips of water produced constant EMG activity but no peristaltic contractions as seen by manometry. In a patient with scleroderma and aperistalsis, swallowing elicited vigorous electrical activity. The different EMG findings without simultaneous contractions at manometry are interpreted as a response to a swallow by the longitudinal muscle of the oesophagus.

Animals↗