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Biomedical subjects

H B Croxatto

Publications and source records attributed to H B Croxatto.

At least 127 records · Page 7Linked to original sources
PubMed1986

Ovum transport in cyclic rats rendered hypo-oestrogenic by treatment with 4-hydroxy-4-androstene-3,17-dione.

The effects of decreasing oestrogen secretion upon the rate of oocyte transport achieved by the administration of 4-hydroxy-4-androstene-3,17-dione were investigated in cyclic rats. Control animals examined during late pro-oestrus showed that the majority of oocytes had entered the uterus. In contrast, when inhibitor was administered from the afternoon of metoestrus or from late dioestrus through prooestrus, oviducal retention of oocytes was observed. When treatment was delayed until the morning of pro-oestrus, only uterine retention of oocytes was observed. The inhibitor decreased oestradiol concentrations in ovarian vein, while systemic testosterone values were increased. Treatment with exogenous oestradiol counteracted the effect of the inhibitor on ovum transport. The elevation of systemic testosterone concentrations by means of subdermal implants of testosterone failed to alter the normal pattern of ovum transport. These results demonstrate that normal oestrogen secretion during late metoestrus and dioestrus is required for the movement of oocytes from the oviduct to the uterus, whereas the preovulatory oestrogen surge is needed for the expulsion of ova from the uterus.

Androstenedione↗
PubMed1986

Anatomy and pathology of tubal pregnancy.

The prevalence of tubal pregnancy has increased markedly during the past decade. The reasons for this are obscure. A systematic gross and histopathologic study of 25 consecutive ectopic pregnancies has been performed using a clearing method not used previously for this purpose. In addition, the presence of the corpus luteum and its location in reference to the tubal pregnancy are documented. Results indicate that trophoblastic spread was predominantly intraluminal in 67% of cases. Intratubal hemorrhage, generally in parallel to trophoblastic spread, often led to marked tubal destruction. Histologic evidence of salpingitis was noted in only seven of 24 specimens (29%). The corpus luteum was contralateral to the ectopic pregnancy in five of 21 cases (23.8%). Clinical correlates and areas of future research are discussed. Results indicate that segmental resection of the tubal pregnancy is appropriate in selected cases.

Adolescent↗
PubMed1985

Clinical chemistry in women treated with six levonorgestrel covered rods or with a copper IUD.

A group of women treated with six levonorgestrel covered rods participated in a study on general chemistry and blood levels of selected hormones at treatment months 20 and 65. A comparable group of Copper T users served as control. Parameters analyzed were the SMA 12 chemistry profile, estradiol, testosterone, cortisol, T3, T4 and TSH. Samples from treated and control subjects were drawn within the same calendar period and were run simultaneously for the assay of each parameter. The values observed were within the normal limits. Significantly higher values of total protein and albumin and lower levels of estradiol and testosterone were found among implant users when compared to the control group. The results suggests little or no metabolic changes in users of six levonorgestrel covered rods which release a daily dose of approximately 105 micrograms.

Adolescent↗
PubMed1985

Contraception with long-acting subdermal implants. A five-year clinical trial with Silastic covered rod implants containing levonorgestrel. The International Committee for Contraception Research (ICCR) of the Population Council.

A total of 189 women volunteered to accept subdermal implants for contraception. The implants were "covered rods", consisting of a core rod containing equal parts by weight of levonorgestrel and polydimethylsiloxane and sealed inside a thin-walled tube of Silastic tubing with medical adhesive. In one study 78 women used 4 3cm rods (study 07) and in the other 111 women used 6 3cm rods. In 5 years of use there were no pregnancies in either group. Terminations because of menstrual problems were twice as frequent among the 4-rod users than among users of the 6 rods. Menstrual pattern analysis is presented for the two rod regimens and compared with the previously reported patterns for the 6-capsule regimen (NORPLANT). Long--term in vivo release rates are also presented.

Adolescent↗
PubMed1985

Plasma levonorgestrel and progesterone levels in women treated with silastic covered rods containing levonorgestrel.

Levonorgestrel and progesterone plasma levels were measured in women bearing levonorgestrel subdermal implants. Two groups using four or six levonorgestrel covered rods and one group of non-hormonal contraceptors were compared. Blood samples were drawn twice a week for six consecutive weeks at different intervals after treatment administration. The mean levonorgestrel levels (mean +/- S.D.) observed in the four rods group was .49 +/- .13 ng/ml in the first year and decreased to .34 +/- .06 in the fifth year of treatment. The mean values observed in the six rods group were .70 +/- .15 ng/ml in the second year and .43 +/- .11 in the sixth year. The levonorgestrel plasma levels were slightly above those found with Norplantr implants in the four rods group and well above it in the six rod group. The highest plasma progesterone value found in each sampling period was above 9 nmol/l in 7 (14%) out of 50 subjects in the four rods group, in 2 (4.3%) out of 47 subjects in the six rods group and in all the 49 control women. In 4 out of the 7 subjects from the 4 rods group and in the two subjects from the 6 rods group, the highest progesterone value was preceded and followed by values lower than 6 nmol/l. It was concluded that the progesterone levels were seldom compatible with the occurrence of ovulation in women treated with four or six levonorgestrel covered rods which release an estimated daily dose of 70 and 105 micrograms, respectively.

Adolescent↗
PubMed1985

Fertility regulation in nursing women: VII. Influence of NORPLANT levonorgestrel implants upon lactation and infant growth.

The objective of this study was to test the influence of NORPLANT implants upon lactation and infant growth. The results obtained during the first postpartum year are reported. One-hundred women were enrolled in the implant group. The control group was formed by 100 women who received a Copper T IUD. Treatments were administered at day 55 +/- 3. At admission all subjects were in exclusive breastfeeding with an adequate weight increase of the infant. No significant differences were found between the treated and control groups in the percentage of women in full nursing at different postpartum intervals, except for the 12th month postpartum where a lower percentage of cases from the NORPLANT group was in the full nursing category. No difference was found in the time of weaning. The infants showed a normal weight gain rate in both groups although the girls from the NORPLANT group showed a significantly lower daily weight increase during the 4th month than the girls from the IUD group. No pregnancies were diagnosed. No women asked for implant removal during the first year. No serious side effects related to treatment were detected. Bleeding irregularities were rare during breastfeeding which is in contrast with what occurs in non-nursing women treated with NORPLANT implants. Levonorgestrel concentrations found in milk were variable and individual values ranged from 23 to 311 pg/ml. The dose received by the infant can be estimated around 15 to 18 ng/Kg/day during the first month of treatment when the higher plasma values of levonorgestrel are observed. These levels is conjunction with the clinical observations reported here minimize the potential problems associated with levonorgestrel transference through maternal milk. Nevertheless, long-term studies are required to settle this matter and until more information is available, NORPLANT implant use in lactating women should be limited to cases who require a highly effective contraceptive method and where non-hormonal methods of similar effectiveness are contraindicated or unacceptable.

Adolescent↗
PubMed1984

Fertility regulation in nursing women. VI. Contraceptive effectiveness of a subdermal progesterone implant.

Six progesterone pellets implanted subdermally were tested as contraceptive method for lactating women. One pregnancy was diagnosed in 1614 woman-months of observation, a failure rate which was similar to that observed in a contemporary group of Copper T users. Nineteen pregnancies were diagnosed in the 677 woman-months observed in untreated lactating women. The progesterone implants were effective when administered either at 30, 60 or 240 days after delivery. The duration of the effective life was 5 months and fertility was quickly restored afterwards. There were no deleterious effects upon maternal or infant health or upon lactation and the rate of child growth. The main problem encountered was the occurrence of pellet expulsion at a variable rate which appeared related to the manufacturing procedure.

Adolescent↗
PubMed1984

Varying responses of ovum transport in mice related to dose and time of administration of oestradiol.

The dose-response relationships between exogenous oestradiol and ovum transport in mice and the effect of treatment on different days of pregnancy were reinvestigated in detail. In addition, serum levels of oestradiol were measured, and their correlation with the various responses was examined. Control animals injected with vehicle alone had the majority of ova in oviductal loops 1 and 2; 3 and 4; or 6 and 7 on days 1, 2, or 3 of pregnancy, respectively. On day four, the majority of ova were found in the uterus. Varying the dose or time of administration of oestradiol determined qualitatively different responses. A single sc injection of oestradiol 5 micrograms or less on day 1 produced scattering of the embryos along the oviduct on day 3 and their accumulation in loops 7 and 8 on day 4, suggesting an increased randomness of the direction of propulsive forces, as well as decreased luminal permeability of the tubo-uterine junction. Doses of 25 and 125 micrograms injected on day 1 caused accelerated transport of ova, some of which entered the uterus as early as 8 hr after treatment. The predominant effect following injection of 1 micrograms on day 2 or days 1 and 2 was acceleration, indicating that oestradiol given on day 2 has opposite effect to and can counteract that of oestradiol given on day 1. Following injection of 25 or 125 micrograms, but not 5 micrograms, on day 1, plasma oestradiol remained significantly elevated through day 2, indicating that tube-locking results from high levels of plasma oestradiol restricted to day 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Clinical chemistry in women treated with levonorgestrel implants (Norplant) or a TCu 200 IUD.

Two groups of implant users and two groups of IUD users participated in the study at different times. In the first groups, fractionation of lipoproteins was performed on serum samples from 28 subjects who had used the implants for 37 months and from 26 subjects who had used the Copper TCu 200 for 30 months. Users of the implants had significantly lower levels of total cholesterol, triglycerides and LDL-cholesterol than users of the IUDs. HDL-cholesterol levels were not different between the groups. In the other groups of women, general chemistries and selected hormone assays were carried out on samples from 30 subjects who had used implants for 51 months and from 24 subjects who had used the TCu 200 IUDs for 43 months. The parameters studied were the SM-12 chemistry group profile, estradiol, cortisol, testosterone, triiodothyronine, thyroxine and thyroid stimulating hormone. In the implant group, mean serum glucose levels were statistically significantly elevated and inorganic phosphorus levels were significantly reduced as compared to the IUD group. In both cases all individual measurements were within the normal range for the population. Testosterone and triiodothyronine levels in the implant group were significantly lower than in the IUD group, but no individual values were outside the normal range for the population. Mean values for all other parameters were not significantly different between the groups.

Adult↗
PubMed1983

Fertility regulation in nursing women: III. Short-term influence of a low-dose combined oral contraceptive upon lactation and infant growth.

The study was designed to test the short-term influence of a low-dose combined oral contraceptive upon lactation and infant growth when treatment was initiated at day 30 postpartum. The contraceptive tested contained ethinyl estradiol 0.03 mg and levonorgestrel 0.15 mg. Two control groups were formed by women who received either an oral placebo or an injectable placebo at day 30 postpartum. An exacting list of requirements for admission and continuation in the study was applied to all groups. The oral contraceptive group had a lower percentage of cases in exclusive breastfeeding at day 91 postpartum when compared to both control groups. Infants in the oral contraceptive group showed a significantly lower average absolute weight at days 61 and 91 postpartum and a significantly lower average daily weight increase during the first month of treatment when compared to both control groups. It was concluded that the oral contraceptive tested had a negative influence upon lactation and child growth.

Adult↗
PubMed1983

Fertility regulation in nursing women: IV. Long-term influence of a low-dose combined oral contraceptive initiated at day 30 postpartum upon lactation and infant growth.

The study was designed to test the long-term influence of a low-dose combined oral contraceptive upon lactation and infant growth when treatment was initiated at day 30 postpartum. The contraceptive tested contained ethinyl estradiol 0.03 mg and levonorgestrel 0.15 mg. Two control groups were formed by women who received an injectable placebo or a Copper T at day 30 postpartum. Women in the injectable placebo group received non-hormonal contraceptives at day 90 postpartum. An exacting list of requirements for admission and continuation in the study was applied to all groups. The oral contraceptive group had a significantly lower percentage of cases in full nursing from the 4th through the 10th postpartum month when compared to both control groups. The average absolute weight of infants in the oral contraceptive group was significantly lower at several ages when compared to the placebo group but not when compared to the Copper T group. No adverse side effects upon infant's health were detected. It was concluded that the oral contraceptive tested showed a moderate inhibitory influence upon lactation when treatment was initiated at the beginning of the second postpartum month.

Adult↗
PubMed1983

Fertility regulation in nursing women: V. Long-term influence of a low-dose combined oral contraceptive initiated at day 90 postpartum upon lactation and infant growth.

The study was designed to test the long-term influence of a low-dose oral contraceptive upon lactation and infant growth when treatment was initiated at day 90 postpartum. The contraceptive tested contained ethinyl estradiol 0.03 mg and levonorgestrel 0.15 mg. The control group was formed by women who chose non-hormonal contraception at the same postpartum time. Only cases who were in exclusive breast-feeding with a minimal infant daily weight increase of 20 g per day during the third month of age were included. The oral contraceptive group showed a significantly lower percentage of cases in full nursing from the 6th postpartum month and a significantly lower infant weight increase during the 4th month of age when compared to the control group. No differences were found in the absolute infant weight up to one year of age. No adverse side effects upon infant's health were detected. It was concluded that the oral contraceptive tested showed a moderate inhibitory influence upon lactation when treatment was initiated at day 90 postpartum.

Adult↗
PubMed1983

Scanning electron microscopy and X-ray microanalysis of foreign bodies associated with Silastic implants in humans.

Polydimethylsiloxane (Silastic) capsules containing megestrol acetate have been implanted in subcutaneous tissue as a method of long-term contraception. Histological studies revealed a granulomatous foreign body reaction around these capsules with birefringent crystals in multinucleated giant cells. Although several authors had interpreted these crystals as steroids, this seemed unlikely since the tissue had been processed with organic solvents. Analysis of these crystals by polarization microscopy, scanning electron microscopy, and X-ray microanalysis demonstrated that the material was talc. The talc was probably introduced as a contaminant from gloves during the implantation. Further analysis showed that capsule fragmentation could not have produced the material since Silastic particles could not be detected.

Contraceptive Agents↗
PubMed1983

Growth pattern of selected urban Chilean infants during exclusive breast-feeding.

This report describes the growth pattern of healthy, low middle and low socioeconomic class Chilean infants during exclusive breast-feeding. Two-hundred forty-two infants who were on exclusive breast-feeding at day 30 postpartum entered the study. Of these, 59% were fully nursing at 6 months and grew at a normal rate without receiving either supplementary milk or nondairy food. Supplementary feedings were administered in 27% of cases because of suspected primary inadequate milk output and in 14% of cases for other reasons such as pregnancy, illness, maternal work, or self-prescription. Full nursing provided the highest rate of weight increase during the first 3 months of life and a greater weight gain for boys than for girls up to the age of 6 months. Gastrointestinal pathology, malnourishment, or hospitalization were rare events in this population. It is concluded that maternal milk alone, if produced in sufficient amounts, can maintain normal growth up to the 6th month of life. The study supports the choice of exclusive breast-feeding on demand plus child growth monitoring up to 6 months over routine prescription of supplements at earlier times particularly where supplement administration fails to meet individual requirements.

Adolescent↗
PubMed1982

Fertility regulation in nursing women. II. Comparative performance of progesterone implants versus placebo and copper T.

A clinical study was designed to test whether sustained administration of progesterone to nursing mothers could prolong lactation and delay the postpartum recovery of fertility. The hormone was administered by subdermal implantation of six pellets that each contained 100 mg of progesterone. This treatment was administered to 84 fully nursing women on day 30 post partum. Control groups were composed of 130 fully nursing women who received an injectably placebo, and by 125 fully nursing women who received a TCu 200 intrauterine contraceptive device. An exacting list of requirements for admission to and continuation in the study was applied to all groups. No pregnancies occurred in the progesterone-treated group from the second to the sixth postpartum month. This period coincided with the period of elevation plasma progesterone attributable to hormone released from the implants. The cumulative probability of pregnancy in the placebo group was 10.2 per 100 women at the sixth month. Treatment with progesterone did not change the duration of lactation or the rate of child growth, and no adverse effects were recorded. These results warrant further investagation of the use of progesterone as an alternative method to prevent conception in nursing women.

Birth Weight↗