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At least 505 records · Page 28Linked to original sources
PubMed1975

Initiating contractions of the gravid uterus through electro-acupuncture.

This is a report on 35 patients on whom electro-acupuncture was tested as a method of initiating contractions. In all cases the membranes remained intact up to the end of the electro-acupuncture. Before the electro-acupuncture none of the patients had experienced any labor pains. The subjective reports were checked by planimetric evaluation of the tocogram curves. A statistical comparison of the values before and after electro-acupuncture was undertaken. Thirty-one cases evidenced certain increase in the intensity of labor contraction frequency (p less than 0.01). Amniotomy was performed immediately after the electro-acupuncture on 31 cases. In a control group likewise consisting of 35 gravidae with intact membranes, no electro-acupuncture was performed. In this control group no significant increase in labor activity could be observed. If amniotomy was performed on gravidae with contractions induced by electro-acupuncture, there was no latent period to be observed. Through avoidance of a lengthened latent period after amniotomy, fetal jeopardy during labor induction can be reduced.

Acupuncture Therapy↗
PubMed1987

Transplacental clearance and blood flows of bovine gravid uterus at several stages of gestation.

Rates of uterine and umbilical blood flows and transplacental clearance of deuterium oxide (D2O) were determined for cows on 137 +/- 1.0 (SE, n = 9), 180 +/- 0.5 (n = 8), 226 +/- 0.4 (n = 9), and 250 +/- 1.8 (n = 5) days of gestation. From days 137 to 250, rates increased 4.5-fold for uterine blood flow, 21-fold for umbilical blood flow, and 14-fold for clearance of D2O. Changes in rates of umbilical blood flow and D2O clearance paralleled increased rates of fetal growth and metabolism, which have previously been reported to occur during the last half of gestation. The regressions of D2O clearance on uterine and umbilical blood flows were significant (P less than 0.01) and explained 94-99% of the variation in placental clearance of D2O. Because the rate of D2O clearance was always less than that of uterine and umbilical blood flows, and because a relatively simple statistical model explained most of the variation in clearance, it was suggested that a concurrent or countercurrent arrangement of maternal and fetal placental microvasculatures is not adequate to explain clearance of highly diffusable substances across the bovine placenta. In addition, a placental exchange diagram of the data showed the existence of severe uneven distribution of maternal and fetal placental blood flows and/or significant shunting of maternal and fetal placental flows away from areas of exchange. Taken together, these data indicate that the placenta of the cow, like those of the sheep and goat, represents a relatively inefficient system of transplacental exchange.

Animals↗
PubMed1982

[Changes in absorption of manganese during gravidity and lactation].

Model studies were conducted using isolated everted sacs of small intestines of rats to test the absorption of manganese during pregnancy and lactation. The intestinal transfer of manganese to the serosal solution and the uptake of manganese into the intestinal wall were measured. The results agree well and yield a comparable pattern of absorption. The Mn absorption rises only slightly in the first and second third of gestation (6th and 12th days of gestation). In the third part of pregnancy (18th day), however, three times more manganese is absorbed compared to the nonpregnant, nonlactating control animals (p less than 0.001). The Mn transfer and uptake decrease distinctly at the day of birth (20th day of gestation and 1st day of lactation) but only for this short period. The absorption increases again significantly (p less than 0.05) on the 3rd, 5th and 8th days of lactation, respectively, while it decreases at the end of lactation (21st day of lactation) to the level of the controls. Reasons for this pattern are discussed.

Animals↗
PubMed1986

Electrical stimulation of the bladder and gravidity.

Following experimental investigations, the authors have performed bladder stimulator implantation for paralyzed bladder patients since 1969. Up to 1983 altogether 32 operations were carried out for bladder paralysis following 21 peripheral and 11 central neural lesions. The patients urinated without residue after the operation. The observations showed that regular use of the stimulator led to the elimination of reflux in patients who had vesicoureteral reflux before the operation. It was found that, if the stimulator had to be removed for any reason after a period of 1 or 2 years, the urinating ability was maintained. Of the 7 female patients operated, 2 became pregnant. During pregnancy and delivery, the patients did not experience any problem with the implanted stimulator, and the children were born healthy and at term.

Adolescent↗
PubMed2002

The effects of sevoflurane on isolated gravid human myometrium.

The volatile anaesthetic agents are known to influence uterine muscle tone. All of the agents studied to date have been found to produce uterine relaxation. This property has been used to produce therapeutic uterine relaxation for difficult obstetric deliveries and the Ex Utero Intrapartum Treatment (EXIT) procedure. This study describes the effects of sevoflurane on isolated human myometrium at concentrations of 0.1, 0.25, 0.5, 0.75, 1.0, 1.5, 2.5 and 3.5 MAC. Sevoflurane produces dose-dependent depression of uterine muscle contractility with an ED50 of 0.94 MAC. Frequency of contraction was increased at concentrations of 2.5 MAC and greater. At concentrations of 3.5 MAC and above, uterine activity was virtually abolished.

Analysis of Variance↗
PubMed2003

'A mate or a meal'--pre-gravid behaviour of female Anopheles gambiae from the islands of São Tomé and Príncipe, West Africa.

BACKGROUND: Malaria prevalence differs between the two islands that comprise the archipelago of São Tomé and Príncipe. This may be due to differences in the biology of local Anopheles gambiae, the only vector on the islands. Survival rate and feeding frequency are two factors influencing vectorial capacity. Anophelines generally feed just once per gonotrophic (oviposition) cycle. Newly emerged insects, however, may feed two or more times during their first oviposition cycle thus increasing the likelihood of becoming infected. The reasons for multiple feeding are not clearly understood and it is still uncertain whether the behaviour is facultative or obligatory. We, therefore, determined survival and sporozoite rates, and examined the behaviour of An. gambiae from the two islands during their first gonotrophic cycle. METHODS: The wing size of 1,410, abdominal condition of 687, gonotrophic age and mated status of 7,264 female M form An. gambiae collected by light-trap, landing catch, resting outdoors or in copula, was determined from four sites in the archipelago. Sporozoite rates assessed by ELISA in 15,533 females from São Tomé and 2,111 from Príncipe were determined. RESULTS: Estimated survival rates ranged between 0.834-0.849 per day in São Tomé and 0.801-0.818 per day in Príncipe. Sporozoite rates of 0.63% in São Tomé were significantly higher than the 0.24% from Príncipe. Overall 49% of females mated on the second night after emergence before feeding, and 51% on the third night and thus fed before mating. The likelihood of mating before feeding increased with wing size. None of the 3,776 parous insects collected showed evidence of recent mating. All but two of the 198 females collected in copula had undeveloped ovaries. Mean wing sizes and the number of insects collected in a sentinel light-trap varied but the proportion of newly emerged insects in the collection did not. The estimated survival rate of the smallest insects was lower than other size groups, but the overall size distribution of each age group was normal. Parous insects were gonotrophically concordant. CONCLUSION: Differences in mosquito survival contributed to the lower sporozoite rates and endemicity of malaria on Príncipe compared to São Tomé. On both islands all newly emerged insects blood fed on the second night following emergence but only became gonotrophically active on the third night after emergence. Smaller insects had a higher 'mortality/emigration' rate than larger ones. We suggest that insufficiency of Juvenile Hormone until the third day of adult life is responsible for gonotrophic inactivity and that by partitioning mating between the second or third day after emergence females maximise their chances of out-crossing.

Analysis of Variance↗
PubMed2002

Swim speed and movement patterns of gravid leatherback sea turtles (Dermochelys coriacea) at St Croix, US Virgin Islands.

Swim speed, dive behavior and movements were recorded for seven female leatherback sea turtles (Dermochelys coriacea Vandelli 1761) during a single internesting interval near St Croix in the US Virgin Islands. Modal speeds ranged from 0.56 to 0.84 m s(-1), maximum speed range 1.9-2.8 m s(-1). Turtles swam continuously throughout the day and night. There were two swim-speed patterns; the most common was slightly U-shaped, with high speeds at the initiation and conclusion of the dive, and the less common was continuous high-speed swimming. The U-shaped speed patterns were coincident with vertical diving by the turtles, while the second pattern occurred most frequently during the daytime, with the turtle swimming within 2 m of the surface. This latter swim behavior appeared to be designed to maximize efficiency for long-distance travel. The hypothesis that leatherbacks rest or bask at midday during their internesting interval is refuted by this study.

Animals↗
PubMed1984

Developmental effects after inhalation exposure of gravid rabbits and rats to ethylene glycol monoethyl ether.

The effects of ethylene glycol monoethyl ether (EGEE) were determined on development in utero. Pregnant New Zealand White rabbits were exposed to air or 160 or 617 ppm EGEE for 7 hr/day from 1 to 18 days of gestation (dg). Virgin Wistar rats were exposed to 150 or 649 ppm EGEE or air 5 days/week for the 3 weeks immediately preceding their breeding. Sperm-positive rats were subsequently exposed to air or 202 or 767 ppm EGEE for 7 hr/day from 1 to 19 dg. Group sizes were 29 to 38 per concentration for both species. Pregestational exposure of rats had no effect on mating success, and there was no effect of EGEE exposure on establishment of pregnancy in either species. Rabbits exposed to the both concentrations had decreased food intake and depressed weight gain. Exposure-related mortality occurred in the 617 ppm EGEE group of rabbits. The only toxic sign seen in rats was reduced weight gain after exposure to 767 ppm EGEE. Exposure induced high embryomortality at maternal toxic concentrations in rats and rabbits, while lower levels induced fetal growth retardation in rats but not in rabbits. Gestational exposure increased the incidence of anomalies and variations; these were primarily of soft tissues in rabbits and of skeleton in rats. Thus, significant evidence of terata, fetal growth retardation and embryomortality were induced in rabbits and rats at levels that were below or similar to those that induced maternal manifestation of toxicity. These data implicate EGEE as a teratogen.

Abnormalities, Drug-Induced↗
PubMed1986

Chronic measurement, using a Doppler probe, of uterine artery flow in the gravid guinea-pig.

A chronic animal model is described which permits for the first time the continuous measurement of uterine artery blood flow velocity in the pregnant guinea-pig by using a miniaturized Doppler flow probe. Preliminary validation revealed that alterations in actual blood flow are directly and proportionally related to the change in the Doppler shift (r = 0.984) from 0 to 100 ml/h. The velocity signal baseline was as stable as that of systemic blood pressure. Depending upon the individual animal's flow velocity, a deviation of 2-5% from baseline was statistically significant. With experience, greater than 90% of preparations were successful and a 30-day interval was often available for study. Uterine artery flow velocity increased steadily between 45 and 55 days of gestation. Instrumentation did not result in fetal growth retardation. A reduction in flow velocity occurred during general anaesthesia using ketamine and the antianxietal xylazine. In agreement with the reports of other investigators using a different model, both hydralazine and angiotensin II increased uterine blood velocity and adrenaline reduced it.

Angiotensin II↗
PubMed1995

Control of blood flow to the gravid uterus of domestic livestock species.

Uterine blood flow during pregnancy is controlled by two distinct phenomena: phasic contractility and tone. Phasic contractility, which mediates short-term contractions, functions through catecholamine activation of alpha 1-adrenergic receptors (AR), leading to hydrolysis of phosphatidylinositol 4, 5-bisphosphate (PIP2) to inositol triphosphate (IP3) and diacylglycerol (DAG). The phasic contractions proceed as IP3 stimulates the release of intracellular calcium stores that activate the calmodulin pathway, causing myosin filaments to slide past actin filaments; however, the contraction is quickly terminated via a reduction in free cytosolic calcium. A tonic contraction is initiated when the DAG generated during PIP2 hydrolysis binds to and activates protein kinase C (PKC) in the presence of increased cytosolic calcium, leading to shortening of the actin filaments. Concomitantly, stimulation of alpha 2-AR increases extracellular calcium uptake via the potential-sensitive channels (PSC), which potentiates activity of the membrane-bound PKC-DAG complexes, thus maintaining the degree of tonic contractility. Progesterone maintains the phasic contractility of uterine arterial smooth muscle throughout pregnancy by increasing alpha 1-AR numbers. Estrogens decrease uterine arterial tone (i.e., increase arterial diameter and flow) via their conversion to catechol estrogens by peroxidase in uterine lymphatic fluid. Catechol estrogens directly inhibit calcium uptake through PSC, resulting in a reduced activity of membrane-bound PKC-DAG complexes.

Animals↗