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Biomedical subjects

G Martens

Publications and source records attributed to G Martens.

16 recordsLinked to original sources
PubMed1992

The FlexiGard 330 ICC, an ultrasound evaluation.

The FlexiGard 330 intrauterine copper contraceptive (ICC) was studied by ultrasound in 405 patients immediately following insertion and at each follow-up visit, for up to 5 years. The present study confirms the validity of the anchoring concept for the suspension of bioactive substances in the uterine cavity. The major conclusion from the study is that the anchor is non-migrating even when observed over a long period of time. Ultrasound examination is the method of choice to evaluate proper insertion technique as well as proper positioning of the device at follow-up.

Evaluation Studies as Topic↗
PubMed1991

Is early repopulation of macrophage-depleted lymph node independent of blood monocyte immigration?

Popliteal lymph nodes (LN) of mice were depleted of their macrophage (M phi) populations in the subcapsular sinus and medulla by subcutaneous injection of dichloromethylene diphosphonate (Cl2MDP)-containing liposomes into the footpads. Complete restoration of both M phi populations could be observed as late as 5 months after liposome administration. This relatively long repopulation time could be due to a depot of liposomes, directly killing all M phi precursors after extravasation into the interstitial tissue of the footpad. On the other hand, local interstitial precursors with very low turnover rates may have been depleted in the interstitial tissue of the hind leg. Therefore, two different types of experiments were performed; one in which M phi-depleted LN were replaced by control LN at various time points after liposome treatment, and another whereby M phi-depleted LN were transplanted into control animals. When liposome-treated, M phi-depleted LN were transplanted into control animals, a complete restoration of both populations in the subcapsular sinus and medulla could be observed within 5 weeks. Control LN transplanted into a Cl2MDP-liposome-treated leg showed a rapid disappearance of M phi from the subcapsular sinus and medulla and these cell populations remained absent for at least 7-8 weeks after liposome treatment, when the first cells started to reappear. Complete repopulation of these areas by M phi took as long as 15 weeks. Using labeled liposomes the presence of a continuous liposome depot was found to be very unlikely. These results suggest that the population of precursor cells that will give rise to M phi in the subcapsular sinus and medulla of a LN is probably contained within the interstitial tissue and is almost independent of precursor supply from the blood compartment.

Animals↗
PubMed1979

The effect of locally administered estrogens on the human cervix.

A randomized study to evaluate the effect of natural estrogens on the unripe uterine term cervix was conducted. One hundred and five term gravidas were studied, of whom 70 were treated with 180 mg 17 beta-estradiol or 250 mg estriol (treated women) and 35 were treated with gel only (control group). In all subjects the distented Foley catheter used for the instillation was left in situ. Twelve hours after the instillation there was no apparent difference in mean cervical progress between treated women and controls and the rather unexpected degree of cervical ripening is atributed to the intra-uterine balloon catheter. The procedure could not be shown to have any untoward effect on the mother or the fetus.

Acid-Base Equilibrium↗
PubMed1978

Gray scale ultrasound for the investigation of early pregnancy.

73 early gestations (6-14 wk) were investigated with gray scale ultrasound. 7 of them ended in spontaneous first-trimester abortion, and in all of these the findings were characteristic for spontaneous interruption of pregnancy. The remaining 66 continued to term. Regression analysis was performed with respect to the diameter of the gestation sac, the fetal crown-rump length, and the placental surface and thickness. The method is considered appropriate for the diagnosis of early abortion and the study of placental morphology and morphometry. On the basis of the results obtained with gray scale techniques, various concepts derived from B-scan observations (e.g. implantation locus and early twin observation) will have to be corrected.

Abortion, Spontaneous↗
PubMed1978

Ultrasound assessment of puerperal uterine involution.

Echographic measurement of the early postpartum uterus was performed, mainly to investigate whether involution patterns correlate with parity, the administration of oxytocin during labor, and lactation. Our findings suggest that these factors do not have a marked effect on uterine involution.

Female↗
PubMed1978

Fetal effects of cervical ripening with extra-amniotic prostaglandin E2 in gel.

A gel containing 0.5 mg prostaglandin E2 (PGE2) was extra-amniotically instilled 90 clinically normal gravidae at term, for ripening of the cervix before elective induction of labor by amniotomy and intravenous PGE2. An acceptable increase in the Bishop score was noted to have occurred in 87/90 women, when assessed eight hours after administration of the gel; 14 of these women were then in established labor, which progressed uneventfully. Four of the 90 subjects required cesarean section for cephalopelvic disproportion. No adverse maternal or fetal effects of the procedure were detected under careful clinical, electronic and biochemical monitoring. However, epidural anesthesia adversely influenced the acid-base equilibrium of the fetus.

Acid-Base Imbalance↗
PubMed1978

Extra-amniotic prostaglandin F2alpha in gel for prelabor cervical ripening.

In 22 normal term gravidas with unfavorable cervix, 5 mg PGF2alpha in Tylose gel was instilled into the extra-amniotic space. The treatment improved the cervical state so much that the women could be successfully induced by conventional methods. The procedure was well tolerated by the mother and it appeared to be perinatally safe.

Cervix Uteri↗
PubMed1977

Elective induction of labor conducted under lumbar epidural block. I. Labor induction by amniotomy and intravenous oxytocin.

Epidural analgesia (bupivacaine) was administered during labor after amniotomy, in some cases supplemented by intravenous oxytocin. A higher incidence of transient uterine hypertonus was seen after blocking. Fetal heart rate changes mainly took the form of bradycardia (in association with uterine hypertonus). At birth, the maternal biochemical condition was characterized by a lower degree of metabolic acidosis, compared to normal unanesthetized controls. The fetuses displayed a slight degree of hypoxia and hypercapnia. The mechanisms underlying these modifications are discussed. Epidural blockade in combination with elective induction of labor, whether or not supplemented by intravenous oxytocin, may carry a risk. Its magnitude is considered acceptable for both mother and fetus provided they are constantly under close surveillance, limited amounts of bupivacaine are administered and the second stage of labor is kept short. However, some warnings against epidural analgesia apply to patients with placental insufficiency and very active labor.

Adult↗
PubMed1977

Elective induction of labor conducted under lumbar epidural block. II. Labor induction by amniotomy and intravenous prostaglandin.

Labor was electively induced at term in 117 clinically normal nulliparae and parous women by combining low amniotomy with intravenous administration of prostaglandin F2 alpha (n = 64) or prostaglandin E2 (n = 53). Analgesia was obtained by continuous lumbar epidural block with bupivacaine. The procedure was very effective in producing vaginal delivery within 24 h after prostaglandin infusion (n = 115), but it was accompanied by an extremely high incidence of uterine hypertonus. Tentative explanations for the transient uterine hyperstimulation are a direct stimulatory effect of the local anesthetic on the contractility of the myometrial fiber and/or a temporarily higher amount of circulating oxytocic compound reaching the myometrium due to local vasodilatation as a result of sympathetic nerve blockade. In some cases uterine hypertonus was associated with slowing of the basal fetal heart rate and, when severe, with the appearance of late deceleration patterns and fetal acidosis. In other cases the fetal heart rate deceleration is explained by the toxic effect of bupivacaine on the myocard. Since both the myometrial hyperactivity and the FHR alterations were temporary, fetal biochemical parameters were unaffected at completion of the first stage of labor. Because with intravenous prostaglandin uterine hyperstimulation is more difficult to avoid and regional analgesia further increases the hazard of both hypertonus and fetal heart rate deceleration, the combined application of an intravenous prostaglandin and continuous epidural analgesia should not be introduced into obstetrical practice.

Adult↗
PubMed1977

A comparison of buccal (oromucosal) and oral prostaglandin E2 for the elective induction of labor.

In 100 clinically-normal women, labor was induced at term by low amniotomy and PGE2. The drug was administered by either the oral or the oromucosal route, the same incremental dose scheme (initial dose of 0.5 mg; hourly increment of 0.5 mg until adequate uterine stimulation or a maximum single dose of 3.0 mg) being applied. Both routes of administration had comparable efficacy and were equally safe. The incidence of abnormal monitoring findings (uterine hypertonus, transient bradycardia and dips II during the first stage; late decelerations, progressive and transient bradycardia during the second stage of labor) and of low Apgar scores were similar. Acid-base and lactate-pyruvate equilibria in mother and fetus were not influenced by the route of drug administration in parous women. In nulliparae treated with PGE2 by the oromucosal route, higher values were found for the fetal-maternal difference in excess lactate than in those given oral PGE2; however, this is probably of little clinical importance.

Administration, Oral↗