Showing papers by "University of Texas Medical Branch published in 1976"
TL;DR: Electromyographic studies of the genioglossus muscle during sleep were conducted in six healthy human volunteers and results are discussed in context with problems encountered in hypersomniac patients with the sleep apnea syndrome.
415 citations
TL;DR: If routine urinary screening is performed, it should be as one aspect of a multiphasic program by the primary physician so that it can be coupled with a clearly defined plan for follow-up and management of subjects with abnormal findings.
215 citations
TL;DR: It is concluded that the cat ventral Root contains a major sensory component and that the Law of Bell and Magendie is not an accurate description of the organization of the ventral root in this animal.
Abstract: 1. The receptive fields were determined for 118 afferent fibres in the S2, S3 and Ca (caudal) 1 ventral roots of the cat. Of these fibres, ninety-three were unmyelinated, another eleven were probably unmyelinated, and fourteen were myelinated, according to estimates of their conduction velocities. 2. Confirmation that the recordings were from ventral root filaments came from electron microscopic inspection of ten of the filaments from which recordings of the activity of unmyelinated afferents were made. 3. Receptive fields were demonstrated for twelve unmyelinated afferent fibres in the distal stumps of the S2 and S3 ventral roots which had been sectioned 3 weeks previously, indicating that the cell bodies giving rise to these fibres were not in the spinal cord. 4. The action potentials of some of the unmyelinated ventral root afferent fibres were complex, suggesting branching of the afferents within the ventral root. 5. One third of the unmyelinated ventral root afferents had receptive fields in somatic structures: the skin and deep tissues. 6. Two thirds of the unmyelinated ventral root afferents had receptive fields in the viscera of the pelvis: the bladder, urethra, vagina, and lower bowel. 7. Many of the unmyelinated afferents in the ventral roots, especially those with cutaneous receptive fields, had high thresholds and may participate in nociception. 8. It is concluded that the cat ventral root contains a major sensory component and that the Law of Bell and Magendie is not an accurate description of the organization of the ventral root in this animal.
165 citations
TL;DR: The studies suggest that the immune deficiency associated with adenosine deaminase deficiency may be related to increased amounts of adenine,adenosine, or adenines nucleotides.
Abstract: Purine and pyrimidine metabolites were measured in erythrocytes, plasma, and urine of a 5-month-old infant with adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4) deficiency. Adenosine and adenine were measured using newly devised ion exchange separation techniques and a sensitive fluorescence assay. Plasma adenosine levels were increased, whereas adenosine was normal in erythrocytes and not detectable in urine. Increased amounts of adenine were found in erythrocytes and urine as well as in the plasma. Erythrocyte adenosine 5'-monophosphate and adenosine diphosphate concentrations were normal, but adenosine triphosphate content was greatly elevated. Because of the possibility of pyrimidine starvation, pyrimidine nucleotides (pyrimidine coenzymes) in erythrocytes and orotic acid in urine were measured. Pyrimidine nucleotide concentrations were normal, while orotic acid was not detected. These studies suggest that the immune deficiency associated with adenosine deaminase deficiency may be related to increased amounts of adenine, adenosine, or adenine nucleotides.
148 citations
TL;DR: The incidence of neurotoxicity may be reduced by employing lower doses of methotrexate in the presence of central nervous system leukemia, in older children and adults, and in the absence of epidural leakage.
Abstract: A patient who developed paraplegia following the intrathecal instillation of methotrexate is described. The ten previously reported cases of this unusual complication are reviewed. The following factors appear to predispose to the development of this complication: abnormal cerebrospinal dynamics related to the presence of central nervous system leukemia, and epidural cerebrospinal leakage; elevated cerebrospinal fluid methothexate concentration related to abnormal cerebrospinal fluid dynamics and to inappropriately high methotrexate doses based on body surface area calculations in older children and adults; the presence of neurotoxic preservatives in commercially available methotrexate preparations and diluents; and the use of methotrexate diluents of unphysiologic pH, ionic content and osmolarity. The role of methotrexate contaminants, local folate deficiency, and cranial irradiation in the pathogenesis of intrathecal methotrexate toxicity is unclear. The incidence of neurotoxicity may be reduced by employing lower doses of methotrexate in the presence of central nervous system leukemia, in older children and adults, and in the presence of epidural leakage. Only preservative-free methotrexate in Elliott's B Solution at a concentration of not more than 1 mg/ml should be used for intrathecal administration. Periodic monitoring of cerebrospinal fluid methotrexate levels may be predictive of the development of serious neurotoxicity.
141 citations
TL;DR: The capacity of short-term memory (STM) as measured by digit span tasks was significantly less for the Subjects who received physostigmine than for the subjects who received placebo, and no difference was observed between the two groups on tasks of consolidation from STM to long- term memory (LTM).
Abstract: Physostigmine was given intravenously to a total dose of 3 mg to 13 subjects; a placebo of 0.25 N saline was given intravenously to 10 other subjects; both groups received 1 mg of methscopolamine bromide subcutaneously preceding the intravenous infusions. A “physostigmine syndrome” consisting of decreased speech, slowed thoughts, mild sedation, expressionless faces, nausea, and decreased spontaneous activity was evident following doses of 1.5 to 2.0 mg of physostigmine. The capacity of short-term memory (STM) as measured by digit span tasks was significantly less for the subjects who received physostigmine than for the subjects who received placebo. No difference was observed between the two groups on tasks of consolidation from STM to long-term memory (LTM).
130 citations
TL;DR: The retrograde transport of horseradish peroxidase was used to determine the distribution of hypothalamic neurons which send axonal projections to the spinal cord of rats and found that Hypothalamo-spinal projections are predominantly uncrossed.
128 citations
TL;DR: It appears from data that intolerance to whole protein formulas can cause a syndrome similar clinically to neonatal necrotizing enterocolitis, and this sensitivity persisted throughout the neonatal period.
128 citations
TL;DR: There is a striking similarity between the distribution of HRP-labeled cells in the dorsolateral pontine tegmentum of the cat and monkey and that of catecholamine-containing cells observed in this area in previous studies.
127 citations
TL;DR: The sites on type I and II collagen which bind to the cell attachment protein (CAP) have been identified using an inhibition assay and the most active peptide obtained from the α1(I) chain corresponds to residues 568 through 835.
126 citations
TL;DR: Quantitative assessment of 50 patients with closed head injury disclosed that anomic errors and word finding difficulty were prominent sequelae as nearly half of the series had defective scores on tests of naming and/or word association.
Abstract: Quantitative assessment of 50 patients with closed head injury disclosed that anomic errors and word finding difficulty were prominent sequelae as nearly half of the series had defective scores on tests of naming and/or word association. Aphasic disturbance was associated with severity of brain injury as reflected by prolonged coma and injury of the brain stem.
TL;DR: It is indicated that liposomes coated with surface ligands may be used to introduce enzyme or other materials into deficient cells possessing appropriate surface receptors, as well as to provide for ligand-receptor interaction with surface Fc receptors of human polymorphonuclear leukocytes.
Abstract: To determine whether ligand-receptor interactions could engender the selective uptake by deficient cells of enzyme-laden liposomes, aggregated human IgG was used to coat liposomes which had previously trapped purified hexosaminidase A (Hex A) By a new, high-yield procedure, Hex A was purified 7000-fold from human placenta: the homogeneous protein had a pI of 54, permitting nonelectrostatic trapping in the aqueous interstices of anionic multilamellar liposomes (molar ratios of phosphatidyl-choline-dicetyl phosphate-cholesterol, 7:2:1) Trapped Hex A was separated from free enzyme by means of Sephadex G-200 chromatography: 13 +/- 03 mUnits of Hex A/mumol of phospholipid became associated with liposomes and trapped glucose, utilized as a marker of the aqueous compartment Once sequestered, the enzyme remained latent until lamellae were disrupted by Triton X-100 Presence of enzyme in aqueous compartments was proved by the demonstration of increased trapping (002-133 mUnits/mumol of phospholipid) with increments in like-sign repulsion of the bilayers produced by increasing molar ratios of anionic dicetyl phosphate (5-20%) To provide for ligand-receptor interaction with surface Fc receptors of human polymorphonuclear leukocytes (PMN's), liposomes were coated by heat-aggregated (62 degrees C, 10 min) human IgG PMN's from Tay-Sachs patients genetically deficient in Hex A activity readily incorporated exogenous Hex A provided in this fashion PMN's exposed to enzyme-laden liposomes coated with aggregated IgG incorporated significantly more Hex A than when the enzyme was presented in uncoated liposomes or in liposomes coated with native IgG, which engages Fc receptors with less avidity Free enzyme was not endocytized Acquisition of specific Hex A isozyme activity by cells (determined by DEAE-cellulose chromatography) was not due to surface adsorption since cytochalasin B, which prevents phagocytosis but not surface adherence; blocked uptake Incorporation of the isozyme by deficient cells was also demonstrated by starch gel electrophoresis, and ultrastructural studies showed that the immunoglobulin-coated, Hex A-containing liposomes were taken up into PMN lysosomes after membrane fusion The studies indicate that liposomes coated with surface ligands may be used to introduce enzyme or other materials into deficient cells possessing appropriate surface receptors
TL;DR: Since 15% of the ventral root axons are sensory, the Law of Bell and Magendie cannot be regarded as an accurate description of the organization of these ventral roots.
Abstract: 1. 29% of the axons in the S3 and Ca 1 caudal ventral roots of the cat are unmyelinated. 2. Approximately one half of these unmyelinated axons survive in the proximal stump of a sectioned ventral root and are regarded as unmyelinated preganglionic efferents. 3. At least 27% of the preganglionic efferents in segments S3 and Ca 1 are unmyelinated. 4. The other half of the ventral root unmyelinated axons arise from dorsal root ganglion cells and survive in the distal stump of a sectioned ventral root. 5. The data in 4, combined with the receptive field data in our companion paper, show that these unmyelinated fibres are sensory. 6. Since 15% of the ventral root axons are sensory, the Law of Bell and Magendie cannot be regarded as an accurate description of the organization of these ventral roots.
TL;DR: The effects of the delayed PF appear to be masked or blocked by an inhibitor-like substance present in crude culture filtrates, and it is postulated that one or both of these factors may participate in the pathogenesis of Salmonella infections.
Abstract: Engerotoxins isolated from Vibrio cholerae and toxigenic Escherichia coli cause permeability alterations in rabbit skin. Firm induration and erythema are observed within 18 to 24 h, and visualization of the reaction may be enhanced by intravenous injection of Pontamine sky blue dye. Two skin permeability factors (PF) have been found in culture filtrates of Salmonella typhimurium. A rapid acting factor, produced optimally in brain heart infusion broth at 37 degrees C by numerous Salmonella species, has a critical bluing time of 1 h after completion of skin testing. This rapid PF is heat stable at 100 degrees C for at least 4 h and has no associated induration. The delayed factor is heat labile, being completly destroyed within 30 min at 75 degrees C and causes marked duration of the rabbit skin within 18 h that is indistinguishable from the permeability reactions of V. cholerae and E. coli enterotoxins. Induration produced by the delayed PF is observed only after chromatography of the culture filtrate on a Sephadex G-100 column. Thus, the effects of the delayed PF appear to be masked or blocked by an inhibitor-like substance present in crude culture filtrates. Both early and delayed factors are estimated to have a molecular weight of at least 90,000. It is postulated that one or both of these factors may participate in the pathogenesis of Salmonella infections.
TL;DR: Clinical reports and laboratory investigations have generally supported the assumption that neurobehavioral manifestations of organophosphate toxicity are attributable to accumulation of acetylcholine at central and peripheral synapses as a result of cholinesterase inhibition.
Abstract: (1976). Behavioral Effects of Organophosphate Pesticides in Man. Clinical Toxicology: Vol. 9, No. 3, pp. 391-405.
TL;DR: The authors could not detect γ‐aminobutyric acid, octopamine, dopamine or norepinephrine in the Retzius cells, in the pigmented tissue, or, with the possible exception of dopamine, in whole ganglia, in pooled samples of 100 non‐chromaffin control neurons.
Abstract: —Previous workers have reported that the colossal cells of Retzius in the segmental ganglia of the medicinal leech contain about 2.3 pmol of 5-hydroxytryptamme (5-HT)/cell body. We verify the identify of 5-HT in the Retzius cells by gas chromatography-mass spectrometry and derive concentrations of 1.3–4.1 pmol/neuron by analyses of eight individually dissected Retzius cell bodies. The Retzius cell bodies contain about 30% of the 5-HT in each ganglion. An average of 25 pmol 5-HT/mg tissue, a concentration about 500 times lower than that in the Retzius cell, was found in the fibrous, pigmented tissue surrounding the leech nervous system. We could not detect γ-aminobutyric acid, octopamine, dopamine or norepinephrine in the Retzius cells, in the pigmented tissue, or, with the possible exception of dopamine (±0.4 pmol/ganglion), in whole ganglia. Furthermore, we could not detect 5-HT in pooled samples of 100 non-chromaffin control neurons.
TL;DR: Dorsal root section reduces the number of ectopic beats associated with short-lasting coronary artery occlusions and that the most likely mechanism is the interruption of the cardiocardiac sympathetic reflex which depends upon afferent fibers running through the dorsal roots.
Abstract: In anesthetized vagotomized dogs and cats the circumflex and/or the anterior descending coronary artery were briefly occluded (5-90 s), and ectopic beats occurring during the occlusion and for 60 s...
TL;DR: A hypothesis is presented relating microtubule assembly and surface membrane modulation suggesting that calcium is the primary modulating signal in the presence of elevated levels of calcium.
Abstract: Indirect immunofluorescence analyses using antibodies directed against 6S tubulin have shown an elaborate cytoplasmic microtubule complex (CMTC) in nontransformed cells in culture. The CMTC is strikingly altered in cells that have been transformed spontaneously by viruses or by chemicals. Assembly of microtubules in vitro and in vivo is markedly inhibited in the presence of elevated levels of calcium. Alteration of the surface of normal cells by brief treatment with low concentrations of trypsin initiate a rapid breakdown of cytoplasmic microtubules. Finally, a hypothesis is presented relating microtubule assembly and surface membrane modulation suggesting that calcium is the primary modulating signal.
TL;DR: Twenty other mutant hemoglobins were detected, in various genetic combinations in 164 kindreds; four of these-Hb Alabama, Montgomery, Titusville, and Mobile-- were previously unknown.
TL;DR: It was shown that at least two antigenically distinct interferons may be involved in suppressing the immune response, and interferon was effective in inhibiting the in vitro PFC response of antigen-primed spleen cells, indicating that it can block the response of memory lymphocytes.
TL;DR: The results suggest that SWS resets a central mechanism influencing termination of inspiration and that this action is offset or eliminated during REMS, and the constancy of diaphragmatic activation and end-tidal P CO 2 suggests that other features of respiratory control are not greatly altered during sleep.
TL;DR: These studies indicate that the transpeptidase and phosphate-independent glutaminase activities are not exhibited by the same protein in human kidney.
TL;DR: The results indicated no loss in discrimination to result from scoring based on only the first 168 items, and conversion tables that can be used to transform MMPI-168 raw scores to standard M MPI clinical scale scores are presented.
Abstract: MMPI response protocols for 194 psychiatric patients were scored on the basis of the first 168 items and then on the usual 400 items The MMPI-168 raw scores were converted to estimates of conventional clinical scale scores The Ss were divided into 10 major categories on the basis of final clinical diagnosis Multiple discriminant analysis was used to compare the discriminant validity of the abbreviated and standard scoring The results indicated no loss in discrimination to result from scoring based on only the first 168 items Conversion tables that can be used to transform MMPI-168 raw scores to standard MMPI clinical scale scores are presented for further research and clinical use
TL;DR: An easy, efficient system for rating radiographs was developed and applied to 1,000 preauthorization case submissions and showed the majority of the examined full-mouth and partial-mouth radiograph series submitted to Pennsylvania Blue Shield were substandard.
Abstract: The study was conducted to gain reliable baseline information on the quality of radiographs submitted to third party carriers. An easy, efficient system for rating radiographs was developed and applied to 1,000 preauthorization case submissions. The films were evaluated and the frequency distribution of errors determined. Results showed the majority of the examined full-mouth and partial-mouth radiograph series submitted to Pennsylvania Blue Shield were substandard. Recommendations for screening radiographs to upgrade their technical quality are offered.
TL;DR: awareness of this fact will explain the not uncommon finding of a cavitary lesion, often containing an air-fluid level, on initial emergency room radiographs of patients who have sustained closed chest trauma.
Abstract: Traumatic pulmonary and paramediastinal pneumatoceles are definite, acutely formed, primary structural manifestations incident to nonpenetrating chest trauma. They are not secondary lesions, i.e., cavities or pneumatoceles resulting from the resolution of a pulmonary hematoma. Awareness of this fact will explain the not uncommon finding of a cavitary lesion, often containing an air-fluid level, on initial emergency room radiographs of patients who have sustained closed chest trauma. This will avoid unnecessary and unpleasant diagnostic procedures, including thoracotomy, for traumatic pneumatoceles are self-limiting, benign abnormalities which usually require no therapy other than observation.
TL;DR: It was observed that cGMP levels, but not cAMP levels, were significantly elevated in murine thymocytes which had been incubated with preparations containing the thymic hormone, thymosin.