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Biomedical subjects

K Benirschke

Publications and source records attributed to K Benirschke.

At least 73 records · Page 4Linked to original sources
PubMed1990

The correlation of arterial lesions with umbilical artery Doppler velocimetry in the placentas of small-for-dates pregnancies.

The placentas of 14 growth-retarded fetuses with abnormal umbilical artery velocimetry and 15 appropriately grown fetuses with normal waveforms were collected immediately after delivery and analyzed in a blinded fashion. A large percentage of the arterial vessels in the placentas from the former group showed abnormal changes in the vessel wall. The percentage of abnormal arterial vessels in all placentas correlated significantly with the resistance index. This study provides an anatomical basis for the elevated resistance to blood flow in placentas from growth-retarded fetuses.

Adult↗
PubMed1990

Morphologic development of the adrenal cortex in squirrel monkeys (Saimiri sciureus).

This study describes the morphology of the squirrel monkey (Saimiri sciureus) adrenal gland in the perinatal period. Adrenals of fetal monkeys had a broad central zone of large eosinophilic cells (fetal zone) surrounded by a subcapsular band of small dark cells (definitive zone). Adrenals of stillborn and neonatal monkeys had a reduced fetal zone and an expanded definitive zone that was differentiated into distinct zona fasciculata and zona glomerulosa. By day 18 postpartum, no remnant of the fetal zone remained.

Adrenal Cortex↗
PubMed1989

Evidence of eosinophil granule major basic protein in human placenta.

A protein immunochemically related to the eosinophil granule major basic protein (gMBP) is found in increased concentration in the plasma of pregnant women and has been localized to placental trophoblasts by immunofluorescence. Pregnancy MBP (pMBP) is indistinguishable from gMBP in its reactivity with polyclonal antisera and a panel of 14 mouse mAbs. We report the purification of pMBP from human placenta by: (a) affinity chromatography over mAb immobilized on Sepharose, (b) gel filtration in 6 M guanidine.HCl buffer, and (c) reversed-phase HPLC. Purified pMBP and gMBP are biochemically indistinguishable in that both: (a) bind to DNA, (b) polymerize and bind to carrier proteins via disulfide linkages, (c) have a molecular weight of 14,000, (d) have isoelectric points greater than 10.6, (e) comigrate in two-dimensional gels, (f) coelute during reversed-phase HPLC on C18 columns, (g) have identical peptide maps after three different digestions, and (h) have partial amino acid sequence identity. This physicochemical identity has important implications as to the role of pMBP in human placentation.

Amino Acid Sequence↗
PubMed1989

Ovarian-pituitary hormone interactions during the perimenopause.

To describe the hormone changes that occur at the onset of the perimenopause, daily urine and random blood samples were collected from 5 peri-menopausal women for 3 or 4 consecutive cycles. Estrone conjugate and pregnanediol-3-glucoronide concentrations were determined for urine samples. Circulating luteinizing hormone, follicle stimulating hormone, progesterone, estradiol and estrone concentrations were determined in serum samples. Two of the 5 women experienced irregular menstrual intervals during the study period. One of these subjects experienced a prolonged intermenstrual interval. Three other women exhibited apparently regular ovulatory menstrual cycles. The prolonged intermenstrual interval of one women exhibiting irregular menstrual intervals was associated with low urinary estrogen levels in the early follicular phase of the affected cycle, followed by increased gonadotrophin levels and increased estrogen levels that rose to exceed normal cycle concentrations by 2- or 3-fold. Increased estrogen levels were followed by declining gonadotrophin levels, minimal progesterone production, and, ultimately, vaginal bleeding. These data suggest that there are some forms of menstrual variability at the time of the perimenopause associated with lowered early follicular phase estrogen levels. Reduced negative feedback and subsequently increased gonadotrophin levels may have stimulated estrogen production which may have suppressed gonadotrophin secretion and lowered estrogen excretion, resulting in the observed oscillations between episodes of hypo- and hyperestrogenism.

Adult↗
PubMed1988

Laterality defects in conjoined twins: implications for normal asymmetry in human embryogenesis.

We evaluated six pairs of conjoined twins: four pairs were dicephalus, and two were of the ischiopagus type. In three of the four dicephalus pairs, the right twin had an abnormality of laterality that included a right aortic arch, reversed great vessel orientation, bilateral right-sided isomerism of the lungs, asplenia, and situs inversus of the viscera. The left twin had normal great vessel orientation and situs solitus in each case. The finding that was unique in these three dicephalus twin pairs was their fused hearts, which were similar in orientation and configuration. The fourth dicephalus twin pair had one normally rotated heart, which was located in the midline and had normally placed chambers and great vessels. Each twin of this pair had normal visceral situs. In the two pairs of ischiopagus twins, each pair had two separate hearts, with normal cardiac structure and great vessel relationships. The viscera expressed normal laterality. Documentation of a defect in laterality in the right twin in three conjoined twin pairs with fusion of the hearts, combined with the presence of normal laterality in three pairs without cardiac fusion, has implications regarding the mechanisms leading to laterality of the human embryo. We suggest that rotation of the heart initiates the embryo's process of lateralization and that the laterality defects of the viscera seen in the right twin are a result of their abnormal cardiac rotation.

Abnormalities, Multiple↗
PubMed1988

Antenatal origin of neurologic damage in newborn infants. I. Preterm infants.

Currently, the diagnosis of white matter necrosis may be performed with echoencephalography when cysts are observed in the white matter adjacent to the lateral ventricles. One hundred twenty-seven infants with a gestational age less than 36 weeks (mean [+/- SE] gestational age = 31 +/- 3.2 weeks) were studied in the neonatal period with echoencephalography to determine the incidence of white matter necrosis and the perinatal variables associated with this complication. Twenty-three infants (18.3%) had white matter necrosis. Thirteen (10.3%) had cysts by day 3 (11 on day 1), indicating that the onset of white matter necrosis occurred antenatally. The incidence of antenatal white matter necrosis was inversely related to birth weight and was more frequent in infants weighing less than 1000 gm (19%). Stepwise logistic regression analysis of 31 antenatal variables showed that placental vascular anastomoses in multiple pregnancies, funisitis, and purulent amniotic fluid were the only complications associated with antenatal white matter necrosis. Follow-up neurologic evaluations were abnormal in four of six patients with antenatal white matter necrosis. The findings in this study focus attention on prenatal, rather than intrapartum and postnatal, factors as causative agents of neurologic morbidity and emphasize the importance of early and sequential evaluation of neonatal brain structures.

Cerebral Hemorrhage↗
PubMed1988

Coarctation of the aorta in Turner syndrome: a pathologic study of fetuses with nuchal cystic hygromas, hydrops fetalis, and female genitalia.

Congenital heart disease is a frequent feature of Turner syndrome. Although the most frequent cardiac lesion is coarctation of the aorta, a spectrum of cardiac defects occurs which is limited almost exclusively to defects associated with decreased blood flow through the left heart. We report the results of gross anatomic and microscopic dissection of 12 fetuses aborted between 16 and 26 weeks' gestation, with the classic Turner phenotype of nuchal cystic hygromas, hydrops fetalis, and female genitalia. Eight fetuses showed a consistent constellation of cardiac defects: diminution of the ascending aorta, large pulmonary artery ranging from 1 1/2 to three times the size of the aorta, large patent ductus arteriosus, and juxtaductal coarctation. Another fetus had hypoplastic left heart and aortic atresia. The remaining three fetuses had normal cardiac anatomy. The lymphatic vessels at the base of the great vessels were carefully examined in nine of the fetuses. Although there was no definite correlation between the degree of cardiac pathology and the extent of lymphatic aberrations at the base of the heart at the time of postmortem examination, the high incidence (75%) of left-sided flow defects among these fetuses, all of whom had large hygromas and severe edema, supports the hypothesis that there is a pathogenetic relationship between lymphatic obstruction and congenital heart disease in the 45,X Turner fetus.

Aortic Coarctation↗
PubMed1987

Implications of the placental structure compatibility for interspecies embryo transfer.

Comparative histological features of the chorionic villi in placental cotyledons of the common eland (Taurotragus oryx ) and bongo (Boocercus euryceros ) antelopes and okapi (Okapia johnstoni ) and giraffe (Giraffa camelopardalis ) were examined. The chorionic villi in both antelope species showed only moderate branching and/or surface corrugation and their cross-sections were polygonal to oval. The close similarity in the structure of cotyledons has been apparently a contributing factor for success in mutual interspecies embryo transfer. The chorionic villi in okapi and giraffe had very different structures. In okapi the villi on cross-section were round and filled with thin connective tissue. They showed minimal branching and surface corrugation. In giraffe the villi showed extensive surface corrugation, had multiple fine branches, and were filled with a more dense connective tissue. Prospect for materno-fetal compatibility in mutual embryo transfer between these species is guarded.

Journal Article↗
PubMed1987

The umbilical cord twist: origin, direction, and relevance.

The purpose of this study was to evaluate the origin, direction, and relevance of the umbilical cord twist. We initially hypothesized that the direction of the helix or twist of the human umbilical cord at birth correlated with the eventual handedness of the child. Among 2801 singleton placentas in this study, only 5% had no twist, and the left twist outnumbered the right twist by 7 to 1, a ratio that is strikingly similar to the predominance of right-handed persons to non-right-handed persons in the general population. Forty-five 3- and 4-year-old children with previously documented cord twists were evaluated with respect to hand preference and performance. The direction of the cord twist was independent of the handedness of the child as well as the mother. We have documented an increased incidence of absent twist and right twist in association with single umbilical artery, suggesting that the impetus for the cord twist is independent on hemodynamic forces in the umbilical cord itself. We further document an increased incidence of absent twist among intrauterine fetal deaths and twins, suggesting that decreased fetal movement can impede the forces leading to normal twisting of the umbilical cord. Absence of cord twist may be associated with adverse prognosis.

Child, Preschool↗
PubMed1987

Functional anatomy of the brachial plexus sheath: implications for anesthesia.

Anatomical study of the brachial plexus of 18 cadavers was undertaken to confirm the presence and significance of "septa" dividing the brachial plexus or axillary sheath. Dissection demonstrated that the sheath consists of multiple layers of thin connective tissue surrounding the various elements of the neurovascular bundle. These septa are incomplete, however, forming small bubble-like pockets when solution is injected. Single injections of methylene blue and Latex solutions into the axillary sheath resulted in immediate dye staining of median, radial, and ulnar nerves, despite the presence of septa. These data demonstrate that there are connections between compartments within the sheath and, therefore, do not support the need for multiple injections when performing an axillary block.

Adult↗