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Biomedical subjects

J Zipper

Publications and source records attributed to J Zipper.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Female non-surgical sterilization: use of endo-uterine quinacrine and betamethasone pellets. Review of the subject: experimental bases--pharmacology--toxicology--efficacy].

Quinacrine produces obstruction of the region of the uterine tube by its fibroblastic granulomatous action. Factors such as the Zn++ and Cu++ content of tubal tissue, as well as the use of anti-prostaglandins, potentialise this action. Two groups of patients were evaluated in this study: Group A--95 women. 180 mg of quinacrine +0.6 mg of betamethasone were inserted into the uterine cavity, on the basis of two insertions separated by a one month interval. Two pregnancies were found by the end of the 2nd year, the percentage failure rate being 2.2 and the Pearl index 0.58. Group B--129 women. 216 mg of quinacrine +1.2 mg of betamethasone were inserted into the uterine cavity, on the basis of two insertions separated by a one month interval. Two pregnancies were found by the end of the 1st year, the percentage failure rate being 0.59 and the Pearl index 0.54. Iatrogenic adverse reactions associated with quinacrine only were not seen in either of these two study groups. None of the pregnancies was ectopic.

Adult↗
PubMed1993

[Non-surgical female sterilization using quinacrine: efficacy of two insertions of quinacrine pellets].

In a group of 159 women at Santiago du Chili, fertility control by means of chemical occlusion of the utero-tubular junction was assessed. Two transcervical intra-uterine insertions of 216 mg of quinacrine, carried out at an interval of one month and associated with 50 mg of intra-uterine diclofenac and 150 mg of intra-muscular diclofenac resulted in a pregnancy rate after 12 months of 2.1 per 100 women and a Pearl index of 1.63 at 27 months after the sterilization process. The complications and adverse events appear to be similar to those which occur during insertion of an IUD and were minor and transient, disappearing within a few hours or at most 2 days after the procedure.

Adult↗
PubMed1988

[Interaction of liposomes with vascular endothelial cells].

Confluent monolayers (3 days old) of cultured calf aortic endothelial cells (line BKEz-7) were incubated for 30, 60 or 120 min with liposomes (reverse-phase evaporation vesicles) in order to investigate by electron microscopy whether and how they interact. This study demonstrates such interactions on a large scale. Electron micrographs show different ways by which liposomes interact with vascular endothelial cells. The observed mechanisms are adsorption, fusion, endocytosis and a transcellular passage of intact liposomes.

Adsorption↗
PubMed1987

Efficacy of two insertions of 100-minute releasing quinacrine hydrochloride pellets for non-surgical female sterilization.

Extensive research has been undertaken to develop a simple method of non-surgical female sterilization. Zipper and associates identified quinacrine hydrochloride as a drug likely to produce tubal occlusion when placed into the uterus. Zipper's early work with a solution of quinacrine led to the development of quinacrine pellets, a delivery system that was designed to bring the quinacrine into prolonged contact with the tubal ostia through extended uterine retention. Three transcervical uterine insertions of 10-minute releasing quinacrine hydrochloride pellets performed at monthly intervals have produced a 12-month pregnancy rate of 3.3 per 100 women. The ultimate goal is to develop an effective, single insertion procedure, but the performance of the quinacrine pellets in occluding tubes has necessitated more than one insertion. FHI developed a 100-minute extended release pellet system with the expectation that more prolonged drug exposure would produce a higher rate of tubal closure. A study of the 100-minute releasing pellet system has been conducted in Santiago, Chile. Two monthly insertions in 112 women has resulted in a 12-month pregnancy rate of 2.0 per 100 women. Postprocedure problems occurring within the first year were reported by 13% of the women; most were minor and transitory.

Adult↗
PubMed1987

The effect of endothelial cell proliferation in vitro.

The proliferation of bovine aortic endothelial cells is highly stimulated by using a plasma clot instead of glass or plastic as a substrate. The cells form a dense monolayer which is usually under grown by a second layer of endothelial cells showing a more reticular growth pattern. When endothelial cells attached to a plasma clot are covered with a second layer of coagulated plasma, the cells arrange to shapes which bear a great resemblance to capillary structures. It seems that this endothelial cell property is only expressed when the entire cell surface is forced to interact with a surrounding adhesive matrix.

Animals↗
PubMed1986

[Sarcocystis alceslatrans (Apicomplexa) from a palaearctic elk (Ruminantia)].

Sarcocysts from a palaearctic moose have been studied for the first time by light and electron microscopy. Because of coincidences in morphology of the cysts, especially of the cyst wall structure and the cystozoides, with the North American species Sarcocystis alceslatrans DUBEY, 1980, they are assigned to this species.

Animals↗
PubMed1985

Absolute and relative myocardial ischemia by isoproterenol overdosage.

Administration of greater than or equal to 10 mg/kg isoproterenol in rats absolutely diminished local myocardial blood flow within 0.5 min continuing up to 45 min. The blood flow reduction was followed by an increased lactate content and a decrease of both the intracellular redox potential and the content of high energy phosphates in the myocardium. The graduation of the initial lactate accumulation in different myocardial regions corresponds to the myocardial distribution of the infarct-like necroses occurring 24 h later. The very early alterations are comparable with an absolute (blood flow reduction), irreversible, and acute ischemia. In the dose range from 0.05 to 1 mg/kg of isoproterenol, an acceleration of the local myocardial blood flow was caused which, however, was accompanied by ischemia-like disturbances, too. Therefore, this condition is considered as a relative ischemia, an increased but insufficient blood supply.

Animals↗
PubMed1983

Propranolol as a novel, effective spermicide: preliminary findings.

The efficacy and tolerability of 80 mg propranolol tablets as a vaginal contraceptive were studied in 198 fertile women for 11 months. The calculated one year life table pregnancy rate was 3.4/100 women and the Pearl index was 3.9/100 women years. No major adverse effects were encountered. The findings suggested that propranolol is an effective vaginal contraceptive whose failure rate compares favourably with that of other methods of contraception. Further study of propranolol and similar compounds is warranted.

Adolescent↗
PubMed1983

[Biopharmaceutical studies on phospholipid liposomes as carriers for the oral administration of insulin].

Insulin-loaded phospholipid liposomes containing 125I-insulin as an indicator were orally administered to mice. The activity distribution in the organism was followed as a function of the time elapsed after application. Biphasic evacuation of the stomach was followed by rapid absorption from the intestine, and the distribution in the blood and body periphery. Precipitation by trichloroacetic acid showed that 20-25% of the indicator were intact or macromolecularly bounded. Actual degradation processes manifest themselves in a rapid increase of the activity in the thyroid gland and the excreta. Furthermore, the effect of an increase in deoxycholate concentration on the inclusion was studied in vitro; it was found that insulin is largely released above a critical concentration coefficient.

Animals↗
PubMed1982

Is dipyridamole an angiogenic agent?

Dipyridamole, a potent inhibitor of the nucleoside transport into cells, has recently been reported to stimulate the proliferation of capillary endothelial cells in the heart and skeletal muscle of rats following long-term treatment. We tested this drug on cultured calf aortic endothelial cells and obtained no evidence that dipyridamole is able to stimulate directly the proliferation and migration of these cells. By using the chorioallantoic membrane model we observed that the pharmaceutical preparation Curantyl induces vascular responses almost regularly. This effect, however, was found to be dependent on the high concentration of hydrogen ions in this preparation and could be prevented by increasing the pH value. A direct angiogenic effect of dipyridamole could not be demonstrated on the CAM.

Allantois↗
PubMed1982

Is the formation of fibrin a necessary event for the initiation of angiogenic responses in the chick chorioallantoic membrane?

Millipore filters belong to number of solid materials which interact with the chorioallantoic membrane (CAM) and frequently initiate local edemas sometimes accompanied by vascular responses. We observed that such reactions can completely be prevented by coating Millipore filter pieces with hydrophilic polymers (e.g. polyvinylpyrrolidone dextran) or by hydrophobic substances as liquid paraffin and vaseline. Protease inhibitors (Contrikal, epsilon-aminocaproic acid) did not prevent such reactions but increased the incidence of vascular responses. By assaying several blood components we found a relationship between the initiation of vascular responses in the CAM and the process of blood clotting. If small amounts (5 to 10 microliter) of citrated bovine or human plasma arae dropped on the CAM angiogenic responses occur as good as regularly. They are also initiated if the plasmas are recalified and small fibrin fragments are placed on the CAM. Chicken plasma, however, regularly induced such responses only in combination with bovine serum or following application of (or treatment with) fibrinolysis inhibitors. We conclude that the formation of a stable extravascular plasma clot with reduced susceptibility to fibrinolysis could be the most important precondition for the initiation of vascular responses, and that all materials, substances or biofactors capable of activating the clotting cascade should also have the capacity to induce angiogenic responses.

Allantois↗
PubMed1982

Effect of topically applied adrenergic blockers on fertility.

The contraceptive properties of two adrenergically active drugs, propranolol and reserpine, were measured in vivo and in vitro. Propranolol became effective as a spermicide for human sperm at a concentration of about 2 x 10(-3) M and for rat sperm at 2 x 10(-2) M. Reserpine was also more effective on human than rat sperm and about 20 times less effective than propranolol. Both propranolol and reserpine prevented implantation when instilled into the uteri of rats. The anti-implantation effect persisted for up to 5 days after instillation of propranolol. When freely breeding rats eventually became pregnant after daily vaginal instillation of propranolol, the number of uterine implantations decreased as the concentration of vaginally instilled propranolol increased. The implantations tended to be toward the fundal end of the uteri, away from the source of propranolol, thus indicating a topical rather than a systemic anti-implantation effect.

Animals↗
PubMed1980

Electrochemical vaginal-oral potentials during the menstrual cycle in women.

Electrochemical potentials were measured with non-polarizable salt electrodes (agar KCl-AgCL) during successive menstrual cycles in eight women. Four of them did not use any contraceptive, two were TCu users and the other two took oral contraceptives. Vaginal-tongue potentials presented biphasic cyclic changes. The vagina became positive in the middle of the menstrual cycle in all the women except those who were using contraceptive pills. Vaginal-oral potentials became positive (+) 24 hours after ingestion of oral contraceptives and up to 24 hours after discontinuation.

Adolescent↗