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Biomedical subjects

J Zipper

Publications and source records attributed to J Zipper.

At least 55 records · Page 3Linked to original sources
PubMed1980

Electrochemical vaginal potential during the estral cycle and pregnancy in the rat.

Potentials were measured with nonpolarizable salt electrodes (agar KCl-AgCl) during the estral cycle and pregnancy of the rat. The vaginal fundus is positive in regard to the external end of the vagina and does not present changes associated with the estral cycle. Vaginal-tongue potentials present biphasic cyclic changes associated with the estral cycle, the vagina being (-) during estro and (+) during diestro. Vaginal-abdominal skin potentials present monophasic modifications associated with the estral cycle. Vaginal-tongue potentials registered during pregnancy were (-) on the first day of pregnancy, (+) throughout pregnancy, and (-) on the first day postpartum.

Action Potentials↗
PubMed1979

Timing of the IUD insertion.

The relationship between the time in the menstrual cycle when a TCu-200 or Cu-7-200 is inserted and subsequent IUD-related events was evaluated. For women who had either TCus or Cu-7s inserted, the pregnancy, expulsion and medical removal rates were similar for insertions performed at any time of the menstrual cycle.

Aging↗
PubMed1979

Behaviour of normal and neoplastic cultured mouse cells on the chorioallantoic membrane of the chicken.

Cultivated normal and transformed fibroblasts of the mouse (short-term cultures of lung fibroblasts and L-cells) have been implanted onto the chorioallantoic membrane of the chick embryo (CAM). Both cell types formed macroscopically visible nodules on the CAM where they induced a weak angiogenic reaction. Labelling of the cells with activated charcoal or 3H-thymidine gave evidence of their invasion into the CAM mesoderm, where they induced the formation of new capillaries. The successive multiplication of the cells led to the formation of tumours, resp. tumour-like cellular accumulations in the hypertrophied mesoderm of the CAM. Treatment of L-cells with the protease-inhibitor Contrykal reduced the invasive properties of the cells. The results presented clearly demonstrate invasive and angiogenic properties of the normal and malignantly transformed cell cultures of the mouse used in our experiments.

Animals↗
PubMed1977

An overview of IUD research and implications for the future.

The limitations of nonmedicated intrauterine devices (IUDs) and the potential for improving IUD performance through the addition of pharmacologic agents are discussed. The mechanisms of action of IUDs, particularly of the copper and the progesterone-releasing devices, are reviewed. The development of improved intrauterine contraceptive devices will depend on an understanding of these mechanisms of action. In order to determine the optimal design of intrauterine contraceptives, the effects of the pharmacologic agents will also have to be evaluated, both separately and in combination with the carrier (vector).

Animals↗
PubMed1977

IUD insertions by midwives: five years' experience in Santiago, Chile.

This report includes data on insertions of Lippes Loop D, Copper-7, and Copper-T intrauterine devices (IUDs) performed by certified nurse-midwives and physicians with comparable levels of training and experience in inserting IUDs. Net 1-year pregnancy, expulsion, and removal rates were used to compare the experiences of the 2 groups. There were no significant differences between the groups in most of the event rates or in the overall method discontinuation rates. The authors conclude that, with adequate training and experience, nurse-midwives can provide this family planning service with no additional risk to patients.

Chile↗
PubMed1977

Electrochemical effects of metals on IUDs.

Electrochemical effects within the uterus are being studied, particularly as they pertain to IUDs made in total or in part of metals. The intrauterine potential as measured with either metal or nonpolarizable salt electrodes is positive at the fundal with respect to the cervical end of the uterus. Placement of dissimilar metal electrodes within the uterus will induce voltage gradients that are roughly predictable from their cell potential in blood as an electrolyte. When copper and zinc electrodes are placed at opposite ends of the uterus, they induce voltage gradients that are typically greater than 100 mv per cm. External copper and zinc wires connected at one end, and with the other ends in contact with various positions on the skin of rats, were found to influence potential gradients within the uterus. When a length of zinc wire was wound around the upper portion of the stem of a small Cu-7 200 IUD, it took about 1 year from insertion for the zinc to disappear. When the zinc wire was wound around the lower portion of the stem, it disappeared in 1 month. The zinc reduced intrauterine corrosion of the copper and it was more effective at reducing copper corrosion when in the lower stem position.

Action Potentials↗
PubMed1977

Six-year continuation rates for CU-T-200 users.

The long-term (six years) contraceptive effectiveness of the Cu-T-200 is evaluated based on 833 first insertions performed by physicians and nurse-midwives. IUD event rates (pregnancy, expulsion, pain/bleeding removal or removal for medical reasons) did not increase with increasing duration of use. The results of the study indicate that the Cu-T-200 is a safe and effective contraceptive for at least six years after insertion.

Adult↗
PubMed1976

Contraceptive efficacy of two different metals using a modified seven vector.

Early studies with copper suggested that few improvements in overall IUD performance could be obtained with the use of more than 200 mm2 of copper. Thus, the use of other metals paired with copper has been investigated. This report of two studies of the small Copper-7, one with zinc and the other with copper alone, suggests that the addition of zinc in the superior position of the small Cu-7 decreases the incidence of pregnancy and that the small Cu-7 may be associated with higher retention rates than the standard Cu-7.

Adult↗
PubMed1976

The clinical efficacy of the repeated transcervical instillation of quinacrine for female sterilization.

The safety and efficacy of the repeated transcervical instillation of quinacrine hydrochloride in a suspension of 5 ml of 2% Xylocaine was evaluated in 200 patients. All instillation procedures were performed during the proliferative phase of the menstrual cycle: the second instillation was made in the first menstrual cycle following the initial instillation and the third and last instillation at 6 months after the first. None of the patients used any adjunctive contraceptives. Follow-up visits were scheduled at 6-month intervals after the last instillation. The potentially serious complications following the instillation were four cases of cortical exitation, and one case of acute adnexitis. The second instillation was not performed for 16.0% and the third instillation was not performed for 16.7% of the patients, for medical and/or personal reasons. Fifty-one pregnancies were reported, 41 (80.4%) before completion of the three instillations. The results of this study show that the instillation schedule used is unsatisfactory for widespread use. Additional studies are currently being conducted to evaluate the use of an adjunctive contraceptive up to the time of the third instillation in order to reduce the high pregnancy rate.

Adult↗