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Biomedical subjects

R Resnik

Publications and source records attributed to R Resnik.

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

Placentomegaly due to fetal congestive failure in a pregnancy with a sacrococcygeal teratoma.

Conditions associated with placentomegaly in which the disproportionate placental enlargement is understood include erythroblastosis fetalis, intrauterine infections and chorioangioma. This report suggests that in a pregnancy complicated by a large sacrococcygeal teratoma, placentomegaly results from high-output fetal cardiac failure secondary to the mass acting as an arteriovenous fistula.

Adult↗
PubMed1979

Catecholamine-mediated reduction in uterine blood flow after nicotine infusion in the pregnant ewe.

The effect of nicotine on uterine blood flow, uterine vascular resistance, and plasma catecholamine concentration was studied in chronically catheterized pregnant sheep equipped with electromagnetic flow probes. The systemic administration of nicotine (14--32 micrograms/kg body wt per min) resulted in a 44% reduction in uterine blood flow (P less than 0.001) and a 203% increase in uterine vascular resistance. Both responses were inhibited by pretreatment with the alpha blocker, phentolamine. Arterial plasma concentrations of norepinephrine and epinephrine, measured by a single isotopic radioenzymatic assay, rose (from 117.9 +/- 6.7 to 201.8 +/- 13.3 pg/ml, P less than 0.001; and from 71.6 +/- 4.5 to 124.1 +/- 8.4 pg/ml, P less than 0.001, respectively) during nicotine infusion. The findings suggest that nicotine exerts a deleterious effect on uterine blood flow mediated through the release of catecholamines.

Animals↗
PubMed1979

Cephalothoracopagus (Janiceps) twinning.

Conjoined twins occur with a frequency of 1/50,000--1/100,000 deliveries. The cephalothoracopagus variety is particularly rare. This paper presents a case report of cephalothoracopagus (Janiceps) twinning, with a detailed pathologic analysis, as well as an historical review and discussion of diagnostic modalities.

Adult↗
PubMed1978

Effects of prostaglandins E1, E2, and F2alpha on uterine blood flow in nonpregnant sheep.

The effects of prostaglandins E1, E2, and F2alpha (PGE1, PGE2, and PGE2alpha, respectively) on uterine blood flow were investigated in chronically catheterized, nonpregnant sheep equipped with electromagnetic flow probes. PGE1 was found to be a potent dilator of the uterine vascular bed and, at initial arterial concentratios of 1.5 micron (500 ng/ml), produced peak uterine blood flows similar to those achieved by a pulsed dose of 1 microgram 17beta-estradiol; PGE2 had less active vasodilating activity. Conversely, uterine intra-arterial PGF2alpha infusions, which produced initial concentrations of 0.1 micron (50 ng/ml), promptly reduced peak estrogen-stimulated uterine blood flow by 60%. All prostaglandin infusions stimulated increases in uterine contractile frequency and base-line tone. The findings demonstrate the sensitivity of the nonpregnant sheep uterine vasculature to prostaglandins.

Animals↗
PubMed1978

Intrauterine fetal demise associated with consumption coagulopathy in a Douc langur monkey (Pygathrix nemaeus nemaeus).

Intrauterine fetal demise was suspected in a Douc langur monkey based on measurements of declining urinary estrogen levels. Additional clinical evaluation by fetal cardiac auscultation, ultrasonic instrumentation, radiologic examination, and amniocentesis supported the diagnosis. Blood clotting studies demonstrated deficiency of factors consistent with a diagnosis of consumptive coagulopathy, a syndrome identical to that observed in man following prolonged intrauterine fetal demise.

Animals↗
PubMed1977

The effect of progesterone on estrogen-induced uterine blood flow.

The effect of progesterone on estrogen-induced uterine blood flow was investigated in repeated experiments in seven nonpregnant, oophorectomized ewes with chronically implanted electromagnetic flow probes and catheters inserted into branches of the uterine arteries. Administered alone, progesterone has no effect on base-line uterine blood flow. Following intramuscular injection of progesterone (3 to 5 mg-per kilogram of body weight), peak uterine blood flow responses to 1 microng of estradiol-17beta were suppressed by 25 per cent compared to those of control animals. Direct intra-arterial infusion of progesterone, at concentrations sufficient to reproduce uterine venous levels observed in late pregnancy in the sheep, inhibited estrogen-induced uterine blood flow by 20 per cent. The findings support the hypothesis that progesterone modulates the estrogen-induced flow responses in both the pregnant and nonpregnant uterine vascular bed.

Animals↗
PubMed1976

The effect of various vasoactive compounds upon the uterine vascular bed.

The effects of various vasodilators on the uterine vascular bed were investigated in nonpregnant, oophorectomized sheep with chronically implanted flow probes and catheters inserted into branches of the uterine arteries. A 1 mug dose of estradiol-17beta (0.224 muM) produces a maximum uterine blood flow response after intra-arterial injection. Adenosine (24 muM) and bradykinin (0.02 muM) were observed to increase blood flow to levels achieved by 1 mug of estradiol-17beta. Acetylcholine, isoproterenol, and histamine were less potent in their vasodilator activity. Atropine, propanolol, and diphenhydramine did not inhibit the increase of uterine blood flow induced by estrogens.

Acetylcholine↗
PubMed1976

Amniotic fluid embolism with survival.

Well-documented amniotic fluid embolism with survival is an uncommon occurrence. A case is reported with characteristic clinical findings in addition to electrocardiographic evidence of acute right heart strain, disseminated intravascular coagulation, and amniotic fluid debris in central venous blood. The impact of this complication on maternal mortality is emphasized. Aggressive therapy with attention to the basic principles of supportive care offers the best chance of survival.

Adult↗
PubMed1976

Principles of organization of an obstetrical unit from scratch.

The previous discussion has attempted to outline some basic principles in developing a high-risk obstetrical unit from scratch. Needless to say, emphasis in specific areas will be dictated by community needs, financial resources, numbers and training of personnel, and space limitations. The basic functions of patient care, education, and self-evaluation can be accomplished in any high-risk obstetrical unit.

California↗
PubMed1975

The effect of actinomycin D on estrogen-induced uterine blood flow.

The effect of actinomycin D on estrogen-induced uterine blood flow was studied in four nonpregnant, oophorectomized sheep, utilizing electromagnetic flow probes chronically implanted around the uterine arteris. Two hours after the intravenous injection of 1 mug of estradiol-17beta per kilogram of body weight, incorporation of [3H]-uridine into RNA was two- to threefold higher (2.7 plus or minus 0.4 S.E.M.) in the control horn than the uterine horn that had received an intra-arterial injection of actinomycin D. Actinomycin D had no effect on the estrogen-induced increase in uterine blood flow.

Animals↗