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Biomedical subjects

H B Croxatto

Publications and source records attributed to H B Croxatto.

At least 163 records · Page 9Linked to original sources
PubMed1979

A three-year clinical trial with levonorgestrel silastic implants.

Silastic implants containing the progestin, levonorgestrel, were tested as long-term contraceptives in 101 women. After three full years of exposure and 2,998 woman-months of use, no pregnancies had occurred. The continuation rates were 87% at 12 months, 79% at 24 months and 66% at 36 months. The most important side effect was excessive or irregular bleeding during the first year. No treatment was offered for this side effect other than vitamins and iron or change of method, with the exception of 3 cases where ethinyl estradiol was used one time for 2 weeks each. Bleeding disturbances led 8 patients to ask for removal of implants. Other side effects were headache, acne and lower abdominal pain. Blood and urine analysis tested 17 different parameters and all but plasma cortisol remained within normal limits throughout the study. A general tendency toward lowered cortisol values was observed and two subjects had more than one value below the normal limit for the population during the study. Glucose tolerance tests during the second year were abnormal in two women with familial diabetes but they returned to normal values spontaneously at the next test. It is concluded that levonorgestrel implants offer effective protection against pregnancy during the first three years of continuous use. Their acceptability and few side effects justify larger trials, especially if treatment of bleeding irregularities is introduced.

Abdomen↗
PubMed1978

Studies on the duration of egg transport by the human oviduct. II. Ovum location at various intervals following luteinizing hormone peak.

The location of ova in the genital tract between 24 and 144 hours following the LH peak was determined in 23 normal women. Nineteen eggs were found in the Fallopian tubes between 24 and 96 hours and five eggs were recovered from the endometrial cavity between 96 and 144 hours following the LH peak. According to the present data and considering that ovulation occurs in the human subject nearly 17 hours after the LH peak, it is concluded that the transport of unfertilized ova in women is characterized by a period of retention in the ampulla, which lasts approximately 72 hours, followed by rapid transit through the isthmus and appearance of the ovum in the endometrial cavity around 80 hours after ovulation.

Adult↗
PubMed1978

Temporal relationships of estrogen, progesterone, and luteinizing hormone levels to ovulation in women and infrahuman primates.

These studies were undertaken to ascertain the interval between the estrogen and LH peaks and ovulation in women, rhesus monkeys, and baboons. Estrogen, progesterone, and LH were measured by RIA. Ovulation was documented by visual examination of the ovaries, histology of the corpora lutea, and recovery of ova. The data for human subjects was based on a group of 23 normal women scheduled for surgical sterilization. Blood was drawn daily between 8:30 and 10:30 P.M. beginning on day 10 of the cycle. Surgery was performed 1 to 5 days after the LH peak. The hormonal findings were correlated with the histology of the corpus luteum. The mean interval from the estrogen peak to ovulation was 34 hours, the interval from the estrogen peak to the LH peak was 24 hours, and that from the LH peak to ovulation was 9 hours. In 46 rhesus monkey cycles and in 53 baboon cycles diagnostic serial laparoscopic examinations were initiated following the estrogen peak and repeated every 24 hours until ovulation was confirmed. The mean interval between the estrogen peak and ovulation was 34 hours in the monkey and 41 hours in the baboon. The intervals from the estrogen peaks to the LH peaks were 12 hours in the monkey and 23 hours in the baboon. The intervals from LH peak to ovulation were 22 hours in the monkey and 18 hours in the baboon. Plasma progesterone levels were significantly increased prior to the LH peak in all three species.

Adult↗
PubMed1978

Clinical trial with subdermal implants containing norgestrienone.

Norgestrienone implants delivering approximately 225 microgram/ day were tested clinically for contraceptive effectiveness and acceptability in 145 women. Five pregnancies occurred in 2259 woman-months of use, one in the 11th month, one in the 15th and three in the 16th month of use. Continuation rate at 12 months was 86.7. The number of bleeding runs and bleeding days was increased in approximately 12% of the subjects. Ten percent of the patients had no bleeding in the first 90 days of treatment. Changes in bleeding pattern led to closures in four cases. Headache and signs of mild androgenicity were among the leading side effects. Blood and urine analysis throughout the study showed normal values of 17 different parameters, but a tendency to lower cholesterolemia not associated with changes in thyroid hormone levels, was observed in several patients. Cortisol was found slightly under the lower normal range in one subject without clinical manifestations of hypoadrenalism. It is concluded that norgestrienone implants should be replaced every twelve months for maximal contraceptive effect and because of their efficacy and good acceptability, evaluation of their long term use is warranted.

Adolescent↗
PubMed1978

Clinical chemistry in women treated with progestogen implants.

Effects on metabolic parameters of six subdermal implants of d-norgestrel, norgestrienone (R2010) and methylnorgestrienone (R2323) were studied in women. In general, tests remained within the normal range. An exception was increases in serum transaminase levels in several subjects on R2323 implants. Average cortisol values showed a tendency to decrease on all three regimens, but remained within the significance only with R2323 at six months and R2010 at 12 months. Serum cholesterol levels showed significant decreases on R2010 implants.

Cholesterol↗
PubMed1978

Effect of 15(S)-15-methyl prostaglandin F2alpha on human oviductal motility and ovum transport.

The effects of an intravenous infusion of 15(S)-15-methyl prostaglandin F2alpha (PGF2alpha) on oviductal motility and ovum transport were studied in women who were scheduled for elective tubal sterilization. Infusion rates of 0.38 microgram/kg/hour or higher caused an increase in oviductal motility in all patients. Lower infusion rates did not always cause a stimulation of motility. Low infusion rates generally caused an increase in the amplitude of contractions without any effect on basal oviductal tone. The higher infusion rates usually caused a large increase in basal tone as well as an increase in the amplitude of contractions. Ova were recovered from the oviducts of five patients who had received an intravenous infusion of 15(S)-15methyl PGF2alpha. The ova were recovered from the ampulla in three patients, from the ampullary-isthmic junction in one patient, and from the isthmus in one patient. Since one would expect to recover ova from the oviducts at similar times under normal circumstances, there was no evidence that this prostaglandin treatment caused an acceleration of ovum transport. These data support the conclusion that a PGF analog which stimulates oviductal motility does not necessarily also accelerate ovum transport in women.

Fallopian Tubes↗
PubMed1977

A study of the time course of egg retention activity in the rabbit oviduct.

Changes in egg retention activity of the oviduct were assessed during the first 5 days after HCG-induced ovulation in rabbits. Dextran microspheres were used as ovum surrogates. They were injected into the peritoneal cavity at 0, 10, 32, 41, 50, 64, 72 and 80 h following HCG. The distribution of ova and surrogates in the genital tract was assessed 24 h following surrogate injection in all groups and at 8 h following surrogate injection in animals injected 50 h after HCG. The distribution of microspheres injected up to 50 h after HCG was similar to that of eggs. Surrogates were not retained at the ampullary-isthmic junction (AIJ) shortly after passage of ova through this region. Morever, spheres injected 38 h after ovulation reached the eggs at the proximal isthmus in 8 h or less. Surrogates injected at 64 h following HCG or later were retained at the AIJ, indicating resumption of retaining activity at this level. It is suggested that egg passage through the AIJ is associated with a temporary reduction of the retaining activity lasting for approximately 16 h. Retaining activity at the AIJ is regained before eggs pass from the proximal isthmus into the uterus.

Animals↗
PubMed1976

Effect of particle size on time course of transport of surrogate ova through the rabbit oviduct.

The time-course of transport of plastic microspheres of 100, 200, 400, 800, and 1000 mu diameter through the rabbit oviduct was studied under various hormonal conditions. During estrus, the rabbit oviduct rapidly transports particles of 200 mu diameter to the uterus. After ovulation, the passage of these particles is delayed, first at the ampullary-isthmic junction, and then along the isthmus, perhaps influenced by a second site of resistance at the uterotubal junction. Particles of 100 mu diameter are not subject to these delays but pass rapidly to the uterus. Our data support the idea that the rapid passage of 100-mu spheres reflects a size-related inability of the resisting "gates" to limit their passage. Pharmacologic doses of estrogen act to prolong or increase the resistance to particle passage at the ampullary-isthmic junction and apparently also accelerate transport through the isthmus. Progesterone presumably increases the efficiency of the "gate" at the ampullary-isthmic junction, hastens transport through the isthmus, and seems to "open the gate" at the utero-tubal junction. Further experiments are required to prove or negate these inferences.

Acceleration↗
PubMed1975

Attempts to programme ovulation with exogenous oestrogens and LH-RH analogue.

An attempt was made to programme ovulation in women on a predetermined day of the menstrual cycle by treatment used to induce ovulation in anovulatory sterility. At laparotomy for elective sterilization the ovaries were observed to assess the occurrence of ruptured follicles and ovulation. Histological analysis of ovaries and endometrium was performed, and ova were recovered from some women. Several regimens were tested but ovulation seldom occurred as planned. Clomiphene citrate, human chorionic gonadotrophin (HCG), synthetic luteinizing hormone releasing hormone (LH-RH), and ethinyloestradiol were ineffective. Human menopausal gonadotrophin followed by HCG was more effective, but multiple ovulations occurred. When one single injection of a potent long-acting LH-RH analogue was given on day 13 of the cycle to 10 women pretreated with ethinyloestradiol signs of recent ovulation were observed on day 15 in seven and on day 16 in two.

Administration, Intranasal↗