PubMed Health⌕ Search

Biomedical subjects

R L Deter

Publications and source records attributed to R L Deter.

At least 109 records · Page 6Linked to original sources
PubMed1981

Estimating fetal age: effect of head shape on BPD.

Several recent obstetrical sonographic examinations in this department demonstrated that variations in the shape of the fetal skull (e.g., dolichocephaly, brachycephaly) may adversely affect the accuracy of the biparietal diameter (BPD) measurement in estimating fetal age. In each case the cephalic index of the fetal skull (short axis/long axis x 100) was in either the dolichocephalic or brachycephalic range based on established postnatal criteria. Consequently, normal values were determined (mean, 78.3) for the cephalic index in utero based on 316 obstetrical sonographic studies performed at 14--40 weeks. Preliminary experience indicates that a cephalic index greater than 1 SD from the mean (less than 74, greater than 83) may be associated with a significant alteration in the BPD measurement expected for a given gestational age, and that the head circumference can be used effectively as an alternative means of establishing gestational age.

Adult↗
PubMed1981

Sonography of fetal urinary tract anomalies.

Experience with 13 cases and a review of 41 cases in English literature indicate that anomalous development of the fetal urinary system can be detected in utero using sonography. Anomalies not compatible with extrauterine life (bilateral renal agenesis, infantile polycystic and bilateral multicystic kidney disease) have distinctive sonographic features that can be detected early enough to allow elective termination. Megacystis, either as a primary finding or secondary to urethral obstruction, can be detected and usually portends a poor fetal outcome. Obstruction at the ureterovesical junction has a distinctive sonographic appearance, but ureteropelvic junction obstruction cannot be differentiated from some cystic renal lesions, particularly when it is unilateral. Even when a precise diagnosis cannot be established in utero, the detection of a fetal renal anomaly may significantly affect obstetric and neonatal management of the benefit of both mother and fetus.

Abnormalities, Multiple↗
PubMed1980

Hypervascularity of the uterine wall during pregnancy: incidence, sonographic appearance, and obstetric implications.

The authors report the incidence (20%) of hypervascularity of the uterine wall (decidual reaction) (1) in 106 pregnant women studied prospectively by ultrasound. An unusual case, which caused problems in diagnosis and management, is reported in detail. The relation between the location and extent of this finding and the location of the placenta is discussed. The authors think that this finding represents dilation of myometrial veins of uncertain etiology, and they conclude that the major implications are that it must be differentiated from pathologic entities that are similar sonographically (1), and that if anterior, it may cause excessive bleeding during invasive procedures.

Adolescent↗
PubMed1980

Fetal ascites not associated with Rh incompatibility: recognition and management with sonography.

Fetal ascites not associated with Rh incompatibility is an uncommon problem that can be detected in utero by sonography. The sonographer should make a systematic search for the cause of ascites in a given case on the basis of well known etiologic possibilities, since this may have a significant effect on the obstetrical management. The use of sonography in the detection, etiologic evaluation, and obstetrical management of nonimmunologic fetal ascites is discussed, and experience with 10 such cases is reported.

Abnormalities, Multiple↗
PubMed1977

Quantitative morphological analysis of early mouse embryogenesis in vitro. I. Perfusion culture system, tissue preparation, sampling.

To facilitate a quantitative morphological analysis of early mouse development under controlled conditions, a perfusion culture system capable of supporting embryogenesis to blastocyst stage has been developed. The use of a mesh system allows identification of individual embryos by position, and control of their orientation during culture and preparation for light and electron microscopy. Quantitative evaluation of tissue-processing procedures has permitted selection of conditions which reduce changes in linear dimensions to -1-6 +/- 1-8% in two-cell embryos. Through the definition of a coordinate system based on mesh structure and the development of a special sectioning procedure, sections can be localized within the intact embryo and three-dimensional coordinates given to any element of embryo volume.

Animals↗
PubMed1976

Freeze preservation of squirrel monkey sperm for use in timed fertilization studies.

These investigations were concerned with the response of squirrel monkey sperm to freezing. A procedure involving preincubation at 37 degrees C, progressive cooling combined with a two-step dilution, and freezing on Dry Ice was applied to semen samples collected by electroejaculation from two animals. Sperm concentrations in these samples were 321.8 X 10(6)/ml (+/-204.1 SD) and 532.8 X 10(6) ml (+/-117.1 SD), respectively. Sperm motility prior to freezing was 68.1% (+/- 15.9 SD) AND 63.6% (+/-14.8 SD). Following freezing and thawing, motilities of 53.8% (+/-17.1 SD) and 51.8% (+/-22.9 SD) were observed. The freezing procedure increased sperm motility in approximately 30% of samples from both animals. Changes in the motile behavior of sperm were not observed after freezing. Serum testosterone measurements, the first made in the squirrel monkey, gave values similar to those obtained for other primates. A progressive decline in testosterone concentration, seen in both animals during the course of these investigations, did not affect semen characteristics or the response of sperm to freezing.

Animals↗
PubMed1975

The measurement of iron in rat liver tissue and subcellular fractions using atomic absorption spectroscopy.

To permit the measurement of iron in small amounts of liver tissue or subcellular fractions, a procedure based on wet ashing and atomic absorption spectroscopy has been developed. This procedure, which can detect iron down to a concentration of 0.1 mug/ml, has been used with ferric chloride and Jectofer (iron-citric acid-sorbitol complex) solutions as well as liver homogenates and subcellular fractions. Interference from constituents of liver tissue has not been observed and measurements on fractions appear to be quantitative. Individual determinations had a variability of approximately 10%.

Animals↗
PubMed1973

Localization of Na + , K + -ATPase and other enzymes in teleost pseudobranch. I. Biochemical characterization of subcellular fractions.

In an effort to determine the subcellular localization of sodium- and potassium-activated adenosine triphosphatase (Na(+), K(+)-ATPase) in the pseudobranch of the pinfish Lagodon rhomboides, this tissue was fractionated by differential centrifugation and the activities of several marker enzymes in the fractions were measured. Cytochrome c oxidase was found primarily in the mitochondrial-light mitochondrial (M+L) fraction. Phosphoglucomutase appeared almost exclusively in the soluble (S) fraction. Monoamine oxidase was concentrated in the nuclear (N) fraction, with a significant amount also in the microsomal (P) fraction but little in M+L or S. Na(+), K(+)-ATPase and ouabain insensitive Mg(2+)-ATPase were distributed in N, M+L, and P, the former having its highest specific activity in P and the latter in M+L. Rate sedimentation analysis of the M+L fraction indicated that cytochrome c oxidase and Mg(2+)-ATPase were associated with a rapidly sedimenting particle population (presumably mitochondria), while Na(+), K(+)-ATPase was found primarily in a slowly sedimenting component. At least 75% of the Na(+), K(+)-ATPase in M+L appeared to be associated with structures containing no Mg(2+)-ATPase. Kinetic properties of the two ATPases were studied in the P fraction and were typical of these enzymes in other tissues. Na(+), K(+)-ATPase activity was highly dependent on the ratio of Na(+) and K(+) concentrations but independent of absolute concentrations over at least a fourfold range.

Adenosine Triphosphatases↗
PubMed1973

Localization of Na + , K + -ATPase and other enzymes in teleost pseudobranch. II. Morphological characterization of intact pseudobranch, subcellular fractions, and plasma membrane substructure.

The pseudobranch of the pinfish Lagodon rhomboides is an unusually homogeneous and structurally simple tissue, well suited to cell fractionation studies. Its principal cell type, closely related to the chloride cells of teleost gill, is characterized by numerous mitochondria in close association with abundant tubular invaginations of the plasma membrane. Other cytoplasmic organelles are rarely encountered. In broken fresh pseudobranch cells negatively stained with ammonium molybdate, a 40 A particulate layer was observed on the intracellular surface of the tubular plasma membrane fragments. Nuclear (N), mitochondrial-light mitochondrial (M+L), and microsomal (P) fractions, obtained by differential centrifugation, were characterized by examination of fixed, embedded pellets and unfixed preparations negatively stained with ammonium molybdate and potassium phosphotung-state. Mitochondria, in orthodox configuration and retaining their outer membranes, were observed in M+L and N. Significant amounts of tubular, sheetlike, or vesicular membrane fragments were observed in all three fractions. Many such fragments, when negatively stained, showed the 40 A particulate surface layer characteristic of plasma membrane invaginations, and in some cases 20-A projections could be resolved on the opposite (extracellular) surface. Since these morphological observations, together with previously presented biochemical data, suggest a plasma membrane localization of Na(+), K(+)-ATPase, the possible association of the enzyme with membrane projections is discussed.

Adenosine Triphosphatases↗
PubMed1973

Infection at the subcellular level. II. Distribution and fate of intravenously injected brucellae within phagocytic cells of guinea pigs.

Cells of Brucella melitensis strain 16 M were labeled with (32)P. When injected into normal guinea pigs, labeled, viable bacteria were taken up and inactivated in liver and spleen during the 60 min after infection. Both uptake and inactivation increased if brucellae were coated with antibrucella antibody. Neither viability nor radioactivity were lost when labeled brucellae were incubated for 60 min in vitro with normal guinea pig blood, liver homogenates, or in defined medium. Incubation for 12 h with antibrucella rabbit immunoglobulin G similarly was innocuous. Livers were removed from infected animals at various times up to 60 min after injection and were separated into subcellular fractions. The numbers of total (determined by radioactivity measurements) and viable brucellae as well as the acid phosphatase activity in the various fractions were determined. Total bacteria and acid phosphatase activity were progressively transferred from the mitochondrial plus light mitochondrial (M + L) fraction to the nuclear (N) fraction. Viability of brucellae declined more rapidly in the N fraction than in other fractions. Examination of M + L fractions by isopycnic centrifugation showed a decrease in viability of both free brucellae and those in particles. The results indicated the formation of bacteria-containing heterolysosomes which progressively increased in size and in which brucellae were inactivated. The antibrucella activity of phagocytes of guinea pig liver in vivo appeared to be greater than that of peritoneal macrophages from immune rabbits or of bovine leukocytes studied in vitro.

Acid Phosphatase↗
PubMed1972

Infection at the subcellular level. I. Localization of intravenously injected brucellae in the vacuolar apparatus of cells of guinea pig liver.

The distribution of Brucella melitensis in various tissues and in subcellular fractions obtained from liver was investigated to evaluate the initial phases of brucellosis in the guinea pig. Fifty minutes after intravenous infection, brucellae were found principally in the blood and liver, with a substantial number recovered from spleen. Fractionation of liver established that most bacteria were found in the mitochondrial plus lysosomal (M + L) fraction; a significant number, however, sedimented in the nuclear (N) fraction. With time, there was a progressive shift of bacteria from the M + L to the N fraction, accompanied by a similar shift in acid phosphatase activities. Isopycnic centrifugation of mixtures of M + L fractions and brucellae permitted complete separation of acid phosphatase-bearing particles from bacteria. Similar experiments with fractions from infected animals showed that viable bacteria were found in both the acid phosphatase and free brucellae regions of the gradient. At 10 min postinfection, 52% of the recovered organisms were in the acid phosphatase region; at 30 min, 65%; at 60 min, 85%; and at 315 min, 79%. Detergent plus sonic treatment of an M + L fraction from the liver of an animal killed 50 min after infection caused most of the bacteria in the acid phosphatase region to shift to the region where free bacteria were found. These data suggested that brucellae sequestered in the liver were located primarily in the vacuolar apparatus of the cells which phagocytized them.

Acid Phosphatase↗
PubMed1971

Quantitative characterization of dense body, autophagic vacuole, and acid phosphatase-bearing particle populations during the early phases of glucagon-induced autophagy in rat liver.

Quantitative characterization of dense body, autophagic vacuole and acid phosphatase-bearing particle populations of rat liver have been made at 10 min intervals during the first 50 min following the intraperitoneal administration of glucagon. Beginning 10 to 20 min postinjection, increases in the number of autophagic vacuoles and in the osmotic sensitivity of acid phosphatase-bearing particles were observed, associated with a progressive disappearance of dense bodies. These changes appeared to reach a maximum 50 min after treatment. The average volume of autophagic vacuoles was found to be 440-870% greater than that of normal dense bodies during this time period. No consistent change in total acid phosphatase activity was noted. A detailed study of autophagic vacuole profile populations revealed the presence of five different types of profiles, two of which, types I and II, accounted for 76.3-94.4% of the profiles examined. Type I profiles primarily contained elements of the endoplasmic reticulum, free ribosomes, and ground cytoplasm. Type II profiles had mitochondrial profiles as their principal constituent, but endoplasmic reticulum and free ribosomes were also seen. At all time points type I profiles predominated, comprising 55-69% of the profiles found. Both profile types were bounded by single and double limiting membranes, the former being predominate. A time-dependent change in the ratio of single to double membrane-limited profiles could not be demonstrated. Morphometric parameters derived from profile size distributions indicated that the number of types I and II autophagic vacuoles increased with time, the rate being greater for the type II particle, except between 40 and 50 min. The average volume of the type II autophagic vacuole was consistently greater than that of the type I.

Acid Phosphatase↗
PubMed1967

Influence of glucagon, an inducer of cellular autophagy, on some physical properties of rat liver lysosomes.

The response of rat liver lysosomes to an intraperitoneal injection of glucagon has been evaluated from studies on the mechanical fragility, osmotic sensitivity, and sedimentation properties of these subcellular particles. It has been found that about (1/2) hr after the injection of glucagon the hepatic lysosomes exhibit a fairly sudden increase in their sensitivity to mechanical stresses and to exposure to a decreased osmotic pressure. At the same time, their sedimentation properties undergo complex changes characterized mainly by a significant increase in the sedimentation coefficient of a considerable proportion of the total particles. In addition, glucagon causes an increase in the proportion of slowly sedimenting particles, with the result that the distribution of sedimentation coefficients within the total population tends to become bimodal. The latter change is more pronounced for acid phosphatase, less so for cathepsin D, and barely detectable for acid deoxyribonuclease. All these modifications are maximal between 45 and 90 min after injection and regress to normal within approximately 4 hr. With the exception of the increase in the slow component, for which no explanation can be advanced at the present time, they are consistent with the hypothesis that glucagon causes an increase in lysosomal size, and may be related to the autophagic-vacuole formation known to occur after glucagon administration.

Acid Phosphatase↗