Showing papers by "University of Texas Medical Branch published in 1969"

Estimation of the coherence spectrum and its confidence interval using the fast Fourier transform

Abstract: Correction factors were devised for correction of bias and computation of confidence intervals around estimates of coherence spectra computed upon Gaussian random time series. Using Monte Carlo methods to compute approximate sampling distributions for coherence, statistical descriptions of the bias and standard deviations were obtained. Correction factors were devised which extend the utility of coherence estimates to a value of coherence = 0. Previously coherence = 0.4 was a lower limit.

Oyster Ciliary Inhibition by Cystic Fibrosis Factor

Abstract: Ciliary inhibition in oysters serves as an assay in identifying a serum factor in cystic fibrosis patients and heterozygotes. Seriums from 47 patients With cystic fibrosis antd 19 heterozygotes caused ciliary cessation within 35 minutes, whereas serums from only 2 of 64 individuals without cystic fibrosis inhibited ciliary activity within this time.

Tumoral calcinosis with hyperphosphatemia. A report of a family with incidence in four siblings.

Abstract: Four siblings with tumoral calcinosis and hyperphosphatemia have been studied for several years. In one the disease was recognized prior to its clinical appearance because of hyperphosphatemia. The hyperphosphatemia is not a result of renal insufficiency or of an abnormal parathyroid response. The hyperphosphatemia and tumors did not occur independently in our patients, and serum phosphorus determinations may be useful for screening. Recurrence after total excision of a mass is common and should be treated by early re-excision. The initial results of this treatment have been fairly good.

A light and electron microscopic study of the normal and the degenerating corticospinal tract in the rat.

Abstract: Motor and adjacent cortex of the right hemisphere was removed from 30 adult male rats and the animals were sacrificed at intervals between 1 and 360 days thereafter. Primary fixation was by perfusion with buffered 4% paraformaldehyde followed by preparation of blocks from the medulla and the mid-cervical region for light and electron microscopy by conventional methods. The normal pyramidal tract contained approximately 100,000 myelinated fibers at the level of the medulla, with 89–99% of these fibers under 3.7 μ in diameter and 29–43% less than 1.0 μ. Shrinkage in the degenerating tract occurred gradually and progressively from the third day on and amounted to 70% in the medulla and 72% in the mid-cervical region by 260 days. In the degenerating tract, throughout the entire period of degeneration, no mitotic figures or positively phagocytic cells were noted and there was no numerical increase or decrease in neuroglia or blood vessels. The rows of interfascicular oligodendrocytes were not altered in any manner except that adjacent rows became close together due to shrinkage. The degenerating fibers were replaced by astrocytic processes oriented in a longitudinal direction. The neuroglia displayed no observable role in the breakdown or removal of the degenerating fibers. Numerous alterations in the fine structure of axoplasm and myelin previously reported by others were confirmed.

Neuroglia electrically coupled to neurons.

Abstract: Applied electric current is transmitted between mammalian glial cells grown in tissue culture. A similar electrical coupling exists between certain neurons as well as between neuroglia and neurons. Although this phenomenon may be a peculiarity of mammalian neural cells maintained in culture, it may, on the other hand, represent a phenomenon with greater neurophysiological significance, a process whereby neurons can become silent.

Electron microscopic radioautographic studies of the carotid body following injections of labeled biogenic amine precursors

Abstract: Adult Syrian hamsters were given a subcutaneous injection of reserpine 3 days before an intraperitoneal injection of (3)H-3,4 dihydroxyphenylalanine or (3)H-5, hydroxytryptophan and the carotid bodies were subsequently prepared for electron microscopic radioautography. Other Syrian hamsters were given a subcutaneous injection of reserpine and the carotid bodies were subjected to a sensitive cytochemical test for the detection of unsubstituted amines. These studies were made to determine whether the labeled amine precursors were incorporated into the cells and to see whether the parenchymal cells were affected by reserpine treatment. Material from hamsters treated first with reserpine and subsequently injected with (3)H-3,4 dihydroxyphenylalanine or (3)H-5, hydroxytryptophan exhibited reduced grains of silver over the cells which were associated mainly with the dense cores of the cytoplasmic granules. These studies offer evidence that the granules of the carotid body incorporate catecholamine and indolamine precursors. Material from hamsters incubated for the presence of unsubstituted amines gave a positive reaction (opaque cytoplasmic granules) for catecholamines but not for indolamines. The latter substances may not be present in quantities sufficient to register a positive reaction in the cytochemical test. The opaque granules, indicative of the presence of catecholamines, decreased in density after reserpine treatment. 5 days after one reserpine injection the granules had regained opacity and were comparable to those seen in the control cells.

The effects of reserpine and hypoxia on the amine-storing granules of the hamster carotid body.

Abstract: The carotid bodies from control, reserpine-treated, and hypoxia-treated hamsters were fixed with phosphate-buffered glutaraldehyde and osmium tetroxide, s-Collidine-buffered osmium tetroxide, or phosphate-buffered glutaraldehyde followed by potassium dichromate incubation. Following glutaraldehyde-osmium tetroxide fixation no differences in density or population of the electron-opaque granules in the glomus cells of either control or experimental animals were observed. With s-Collidine-buffered osmium tetroxide and the glutaraldehyde-dichromate technique a marked decrease in density without an appreciable reduction in number of granules was noted after reserpine treatment, while in hypoxia-treated hamsters the density and population of the granules were not different from those of the controls. The results indicate that reserpine depletes the amines without granule disappearance and that hypoxia does not affect the amine content of the granules. It is suggested that following glutaraldehyde-osmium tetroxide double fixation, persistence of the density of the granules in reserpine-treated animals is due primarily to the nonamine content, and that the amines in the glomus cells are probably not directly involved in the respiratory reflex.

Pathomorphology of experimental head injury due to rotational acceleration.

Abstract: We have shown that pure non-deforming rotational acceleration to the head is capable of producing lesions not only in the brain but through the entire length of the spinal cord, extending to the cauda equina.

The Stimulation of Lactase by Feeding Lactose

Abstract: Weanling Sprague-Dawley rats were given increasing doses of lactose over a seven-week period. The mid-jejunum was selected for disaccharidase analysis at a pH of 6.0. Lactase and cellobiase activity were stimulated significantly by total mean-paired analysis. While sucrase and maltase tended to increase. there was no statistically significant change.

Cytoplasmic fine structure during hormonally controlled differentiation in vaginal epithelium.

Abstract: Cells of the vaginal epithelium of ovariectomized mice undergo differentiation in response to estrogen or progesterone injection. Estrogen causes an increase in number of cytoplasmic filaments in the basal and newly formed spinous layer and mucification of surface cells already present. The cells derived from the basal layer under estrogen influence later form a keratinized epithelium. Progesterone causes heightening and mucification of surface cells and invasion of leucocytes into the epithelium without mucification or keratinization of other cells. When estrogen is followed two days later by progesterone, spinous and more superficial cells are lost and replaced my mucous cells derived from the basal layer. Although the fine structure of basal and spinous cell cytoplasm looks identical, the spinous cells do not form mucous cells under progesterone influence. The reverse sequence of progesterone followed by estrogen produces a low epithelium which is then replaced by a keratinized epithelium. The surface mucous cells present during progesterone influence do not keratinize, however. Thus, fine structural features of basal cells typical for the influence of a given hormone do not limit or characterize the potential of daughter cells derived from that layer. Conversely, when hormones are used in sequence, cells which leave the basal layer under the influence of one hormone do not acquire the fine structural features characteristically produced by the second hormone used, even though basal cells are readily altered.

Bilateral central retinal artery occlusion in homocystinuria. A case report.

Abstract: This article reports the first known case of bilateral central retinal artery occlusion associated with homocystinuria. Vascular occlusion may well explain cases of optic atrophy and sclerotic vessels which have been reported in the past.

Broad-spectrum screening of psychotherapeutic drugs: thiothixene as an antipsychotic and antidepressant.

Abstract: Thiothixene was studied simultaneously in both schizophrenic and depressed patients. Seventy‐two newly admitted schizophrenic patients and 64 depressed patients were treated for 4 weeks with relatively modest doses. As indicated by interview ratings coded on 2 psychiatric rating scales, the drug was highly efficacious in both types of patients, the degree of improvement for each general group of patients being among the highest of our series of evaluations of antipsychotic and antidepressant drugs. When the results of treatment of 5 different schizophrenic Stlbtypes were reviewed, there were no differences between the responses of various types of schizophrenic reactions. The same situation applied to 3 subtypes of depressive reactions. Side effects were chiefly related to weight gain, extrapyramidal syndromes (including akathisia), anticholinergic effects, and sedation.

Accelerated maturation of chick embryo skin treated with a prostaglandin (PGB1): an electron microscopic study.

Abstract: One of the fatty acid derivatives called prostaglandins, PGB1, when applied to organ cultures of developing chick skin with feather organ loci, completely blocks feather organ development, but stimulates proliferation and keratinization of the epidermis. Control and PGB1 treated explants were harvested after one, two, and three days in culture and processed for study by electron microscopy. Fine structural observation of control and treated skins indicate the following. (1) Tonofilaments appear much sooner in treated explants than in controls, and are distributed at all levels of the epidermis. (2) The cristae of mitochondria in epidermal cells of treated skins are long, closely apposed, and oriented parallel to the longest axis of the organelle as contrasted with a transverse orientation for them in control epidermis. (3) There is increased deposition of collagen in the mesenchyme of treated skins as contrasted to that observed in controls. (4) Unusual structures (inclusion bodies) occur throughout the stratified and superficial epidermis of treated skins and are composed of fine filaments and granules measuring about 30 A in diameter. They are often associated with tonofilaments. (5) Small but numerous vacuoles appear in the epidermal cells of treated skins and seem to develop from cisternae of the Golgi apparatus or endoplasmic reticulum. The change in orientation of cristae of the mitochondria, vacuolation of the epidermis, and appearance of the inclusion bodies first occurs after two days of treatment with PGB1 in culture. These observations coincide with previous data demonstrating that restitution of feather organ development can be accomplished after one day of treatment with PGB1, but not after two days of treatment. The observations are consistent with an accelerated maturation process, but may be correlated with a specific and irreversible change in a metabolic event necessary for feather development.

Relationship of Leukemia to Lung and Stomach Tumors in Mice Fed Benzo(a) Pyrene

Abstract: SummaryCFW mice fed 0.25 mg of benzo(a)pyrene/g of food develop gastric papillomas and squamous cell carcinomas, pulmonary adenomas, and leukemia. Mice that develop leukemia have a significant increase in the number of pulmonary adenomas. There is no relationship, however, between the occurrence of pulmonary adenomas and gastric tumors in this nonleukemic group of mice.

Intestinal slow waves: decrease in propagation velocity along upper small intestine.

Abstract: Electrical activity was recorded from platinum electrodes permanently implanted on dog small intestine. Dogs were unanesthetized, healthy, and cooperative when studied. Slow waves appeared to decelerate as they passed along the upper small intestine. Their velocity was about 15 cm./sec., 24 cm. above the ligament of Treitz, but only 3 cm./sec., 24 cm. below the ligament of Treitz. This decrease in velocity occurred over a region of upper small intestine in which the frequency of slow waves remained essentially constant.

Estimation of coherence spectrum of non-Gaussian time series populations

Abstract: Previous work on computation of coherence estimates between two time series and the confidence intervals about these estimates has always assumed that the time series have a Gaussian probability density function. Here a Monte Carlo study was performed, computing coherences and confidence intervals upon non-Gaussian time series. Using both a rectangular distribution and a x2distribution with one degree of freedom, the results appear to justify the notion that the assumption of a Gaussian distribution has a fairly small importance in the computation of the above statistics.

Anticollagen Antibodies Following Thermal Trauma

Abstract: SummaryIt was shown by a latex agglutination technique that rats, following thermal injury, are stimulated to produce antibodies to the acid-extractable fraction of collagen in skin. These antibodies do not agglutinate particles coated with the salt-extractable collagen but can be absorbed by this precursor of acid-extractable mature collagen. The anticollagen antibody in rats also reacts with bovine gelatin. An antibody-containing fraction of serum from burned rats was isolated by gel filtration and appears to be a 16.5 S20 macroglobulin by ultracentrifugation and is inactivated by mercaptane reduction. Antibodies to rat collagen and bovine gelatin were also demonstrated in the serum of normal humans. In burned humans the agglutinins disappeared following an extensive burn, presumably by reaction with circulating antigen, and reappeared during convalescence.