Search PubMed⌕ Search

Biomedical subjects

L Smith

Publications and source records attributed to L Smith.

At least 523 records · Page 29Linked to original sources
PubMed1986

Communicative, sensorimotor, and language skills of young children with Down syndrome.

The transition from preverbal to verbal communication of retarded and nonretarded children was explored in a prospective, longitudinal study. Mental development was tested at ages 13 months and at 2 and 3 years. At age 2 years, the MA of the retarded subjects matched the MA of the nonretarded at 13 months. Sensorimotor development of the retarded children at 2 and 3 years of age was assessed by the Uzgiris-Hunt scales. Splitting the sample according to whether or not the retarded subjects had reached Sensorimotor Stage 6 at age 3 yielded differential results on concurrent language skills. Pragmatic skills measured at age 2 for the retarded subjects were deficient as compared with such skills assessed at 13 months for the nonretarded subjects. Results seem to support the postulate of a skill-specific homology in the transition from preverbal to verbal communication.

Child Development↗
PubMed1986

The pulmonary microvascular response to infusion of live Escherichia coli in sheep with acutely or chronically prepared lung lymph fistula.

The effects of infusion of live Escherichia coli bacteria in awake sheep with a chronic lung lymph fistula (n = 15) were compared to anesthetized animals (n = 7) receiving the same septic insult after surgical trauma including bilateral thoracotomies for lung lymph cannulation (acute group). During preseptic baseline conditions, pulmonary arterial pressure (Ppa) and central venous pressure (Pcv) were increased and leukocytes decreased in the newly operated animals compared to the sheep with a chronic lung lymph fistula. After i.v. infusion of live E. coli 10(9) X kg-1 b.w. over 20 min, arterial pressure (Psa), cardiac output (Qt), leukocytes, and partial pressure of arterial oxygen (PaO2) decreased in both groups. Ppa peaked after 15 min at 37.2 +/- 2.5 in the chronic and 33.4 +/- 3.3 mm Hg in the acute group. In the chronic group, Ppa remained elevated but not in the acute group during the rest of experiment. Lung lymph flow (QL) increased significantly in both groups during the initial high Ppa, but it increased to a higher level in the chronic group. After 150 min, QL did not differ between the groups but remained elevated over baseline. Lymph-to-plasma concentration ratio (L/P) for total protein decreased in the chronic group during the initial high QL. This decrease was not seen in the acute group that had a significantly higher L/P between 30 and 120 min after sepsis. The high QL with unchanged L/P compared to baseline indicated increased permeability in the pulmonary microvessels in both groups but the changes in permeability, hemodynamics, or respiratory parameters after sepsis were not aggravated by the surgical trauma.

Acute Disease↗
PubMed1986

Clinical studies of chemonucleolysis patients with ten- to twenty-year follow-up evaluation.

A follow-up evaluation of 357 patients injected with chymopapain ten to 20 years earlier included 97 females of mean age 42.2 years and 260 males of mean age 41.6 years. Pain distribution and physical findings were positive for discogenic involvement of long duration prior to chemonucleolysis. Eighteen patients were treated under worker's compensation. Postoperation, significant back pain persisted less than 24 hours in seven patients, less than six days in 133, less than 21 days in 178, from one to three months in nine, and between three and six months in two patients. Leg pain remained less than 24 hours in 32 patients, between one and five days in 212, between six and 21 days in 96, between one and three months in seven, and between six and 12 months in three patients. Similar improvement in extensor hallucis longus weakness and straight leg raising was also noted. Pain relief in the long term showed none persisting in the 158 patients or 44%, mild remaining pain in 107 or 30%, moderate pain in 71 or 20% and some pain in 21 or 6%. Thus the result was graded satisfactory in 74%. Complications included thrombophlebitis in two, pulmonary emboli in two, severe abdominal stress two days postoperation in one, severe anaphylatic reaction in one, and transient chest pain of undetermined etiology in one patient. All made good recovery from these complications.

Activities of Daily Living↗
PubMed1986

No protection in sheep by high-dose methylprednisolone against pulmonary microvascular injury following trauma.

The osmotic reflection coefficient (sigma) of the pulmonary microvessels in sheep was estimated after a preparative trauma, and the effect of a single, high (30 mg kg -1 b.w.) dose of methylprednisolone (MP) (n = 7) compared to a dose of normal saline (S) (n = 8) was evaluated. After bilateral thoracotomies for lung lymph cannulation and placement of a balloon catheter in the left atrium, the animals were followed during anesthesia for 1 hour. Left atrial pressure (Pla) was then increased and 2 levels of filtration-independent lymph to plasma protein concentration ratio (L/P) were recorded. After the operation leukocyte and platelet counts in both groups decreased significantly. Lung lymph flow (QL) increased during the first hour without hemodynamic changes, whereas L/P decreased in the MP group but was unaffected in the S group. Partial pressure of oxygen (PaO2) was spontaneously improved postoperatively in the MP group but remained unchanged in the S group. The 2 levels of filtration-independent L/P were reached at Pla 28.7 +/- 2.8 and 34.3 +/- 1.6 mm Hg in the MP group and 25.6 +/- 2.2 and 31.3 +/- 1.3 mm Hg in the S group. QL increased by 500 +/- 80% (n = 7) and 930 +/- 210% (n = 7) at the 2 levels of increased Pla with unchanged L/P at 0.44 +/- 0.03 and 0.46 +/- 0.04, respectively, in the MP group. Corresponding values in the S group were a 590 +/- 160 (n = 5) and 730 +/- 180% (n = 3) increase in QL with L/P 0.41 +/- 0.02 and 0.40 +/- 0.03, respectively. sigma in the MP group was 0.54 +/- 0.04, and sigma in the S group was 0.62 +/- 0.02, which was not significantly different. Thus pretreatment with MP did not prevent the development of a permeability lesion following surgical pulmonary trauma, but an early minor protective effect of MP could not be ruled out.

Animals↗
PubMed1985

Temperature and nucleotide dependence of calcium release by myo-inositol 1,4,5-trisphosphate in cultured vascular smooth muscle cells.

Inositol 1,4,5-trisphosphate (IP3) rapidly increased 45Ca2+ efflux from a nonmitochondrial organelle in cultured vascular smooth muscle cells that were permeabilized with saponin. A nucleotide, preferably ATP, was essential for IP3-evoked 45Ca2+ release. Two nonhydrolyzable ATP analogues satisfied the nucleotide requirement for IP3-evoked 45Ca2+ release. IP3 strongly stimulated 45Ca2+ efflux at low temperatures (1 to 15 degrees C). Decreasing the temperature from 37 to 4 degrees C inhibited the rate of IP3-stimulated efflux by only about 33%. The failure of such low temperatures to strongly inhibit IP3-induced 45Ca2+ efflux suggests that IP3 activated a Ca2+ channel, rather than a carrier, by a ligand-binding, rather than a metabolic, reaction.

Adenine Nucleotides↗
PubMed1985

Bryostatins: potent, new mitogens that mimic phorbol ester tumor promoters.

Bryostatins (2 ng/ml), when combined with insulin in serum-free culture medium, are strongly mitogenic for Swiss 3T3 cells that have been arrested in the G1/G0 phase of the cell cycle. The mitogenic effect of the bryostatins is similar to that of 12-O-decanoylphorbol-13-acetate (TPA). A prior treatment of the cultures with TPA eliminated the mitogenic response to bryostatin and to a second addition of TPA. Conversely, a prior treatment of the cultures with bryostatin eliminated the mitogenic response to TPA. Bryostatin potently inhibited the binding of [3H]phorbol dibutyrate to a high affinity receptor in the cells. The findings suggest that the bryostatins and TPA act via the same receptor, possibly protein kinase C.

Animals↗
PubMed1985

An analysis of aboriginal mortality in NSW country regions, 1980-1981.

The total number of Aboriginal deaths occurring in selected country regions of New South Wales in 1980 and 1981 has been estimated, based on the deaths reported by Aboriginal health workers and those identified on the newly modified Form of Notification of Death. Aboriginal mortality was more than four times that of the total NSW population, with young and middle-aged adults having death rates up to 12 times higher. The Aboriginal expectation of life at birth was estimated at 48 years for men and 57 years for women. The principal causes of death were diseases of the circulatory system and injuries. The effect of alcohol appeared to be substantial, particularly in the 35-44 year age group.

Adolescent↗
PubMed1985

Monoclonal antibodies to cytochrome c from Paracoccus denitrificans: effects on electron transport reactions.

The effect of a monoclonal antibody to a soluble cytochrome c from Paracoccus denitrificans was tested on the membrane-bound electron-transport system of this bacterium. This antibody (F3-10.2) and one previously described (F3-29.4) (Kuo, L.M., Davies, H.C. and Smith, L. (1984) Biochim. Biophys. Acta 766, 472-482) were deduced to bind to the cytochrome c in the area including amino acid residue number 23 on a loop on the side of the heme crevice. In contrast to the observations with the previously tested antibody, the present data show the second antibody to block completely the reaction of the cytochrome c with cytochrome c oxidase but not that with cytochrome c reductase. Neither antibody has an appreciable inhibitory effect on the NADH oxidase of the isolated detergent-treated membranes. The two antibodies bind in different ways, giving insight into the interaction of a soluble protein with membrane-bound enzymes. The data indicate that the reaction sites on the cytochrome c for the oxidase and reductase moieties of P. denitrificans are different. They also argue against the need for a dissociable cytochrome c comparable to that which functions on the mitochondrial inner membrane.

Antibodies, Monoclonal↗
PubMed1985

The human cellular abl gene product in the chronic myelogenous leukemia cell line K562 has an associated tyrosine protein kinase activity.

Three antisera against the mouse v-abl gene product were used to identify two potential human c-abl gene products in the chronic myelogenous leukemia cell line K562. Two antipeptide sera were generated in rabbits using the predicted amino acid sequence of the mouse v-abl gene product. One antiserum was made against a polypeptide overlapping the in vivo tyrosine phosphorylation site of murine P120gag-abl and what is believed to be a homologous tyrosine phosphorylation site of the predicted normal human c-abl gene product (v-abl 263-280). The second antipeptide serum, abl 389-403, was generated against a predicted hydrophilic peptide of the v-abl gene product. Immunoprecipitation from K562 cells metabolically labeled with [32P]orthophosphate by a mouse tumor regressor and abl 389-403 antipeptide sera detected two proteins of 190,000 and 240,000 Da. Both proteins were labeled primarily at serine and, to a much lesser extent, at tyrosine residues. Immune complex kinase assays using conditions that allow the tyrosine phosphorylation of P120gag-abl showed that in vitro phosphorylation of P190 and P240 occurs primarily at tyrosine residues. The detection of these enzymatically active human c-abl gene products is a rare observation which may be in part attributed to the c-abl gene translocation from chromosomes 9 to 22 occurring in the vast majority of chronic myelogenous leukemia patients.

Abelson murine leukemia virus↗
PubMed1985

F-actin rings are associated with the ring canals of the Drosophila egg chamber.

Staining of Drosophila egg chambers with rhodaminyl-lysine-phallotoxin (RLP), a specific stain for F-actin, has demonstrated the presence of dense F-actin rings associated with the inner surfaces of the ring canals. They were first observed in the distal part of the germarium where rings of four different size classes were found, differing in diameter by up to twofold. The ring sizes are considered to correspond to the ring canals formed at each of four successive incomplete cleavages. During the growth of the egg chamber the actin rings were found to increase in diameter from less than 1 micron to approx. 10 micron. Concomitantly a secondary outer ring of more diffuse material is built up in association with the cell membranes. A well developed array of microfilament bundles was also associated with the nurse cell plasmalemma. In stages where the transfer of the bulk of the nurse cell cytoplasm into the oocyte was occurring the rings came closer together in a central area. In late stage chambers the F-actin rings and the microfilament bundles appeared to be incorporated into large irregular masses of actin, which subsequently disappeared as the mature oocyte formed. The F-actin rings are suggested to act as mechanical strengthening elements for the canal plasmalemma, whilst cytoplasmic transport occurs through the ring canals.

Actins↗
PubMed1985

Creamatocrit, carbon content, and energy value of pooled banked human milk: implications for feeding preterm infants.

It is convenient to calculate milk energy from the creamatocrit but in order to assess the accuracy with which energy content can be predicted in this way, the creamatocrit, the percentage of carbon, and the calorie value of milk were determined in 11 samples of pooled pasteurised human milk. The calculated milk energy was compared with direct measurements of milk energy by static bomb calorimetry. The errors in calculation ranged from -5.6 kcal/100 ml to + 19.5 kcal/100 ml in milk samples whose measured energy was 34.5 to 63.1 kcal/100 ml. In 9 milk samples energy values were over-estimated by calculation and in the remaining 2 milk samples energy values were underestimated. The correlation between creamatocrit and measured energy value in pooled pasteurised milk was weaker than in previous studies using fresh milk. The percentage carbon was determined in our milk samples as a measure of their total organic constituents, and this appeared to be a more accurate predictor of milk energy than the predictive value of the creamatocrit which is only a measure of milk fat. In pooled pasteurised milk the relatively weak predictive value of the creamatocrit may be due to variations in the other constituents of milk apart from fat which provide energy, namely protein and lactose.

Calorimetry↗
PubMed1985

Primary pediatric care. A comparison of use by adolescent and older mothers.

This survey compares the use of pediatric services during the first year of life by infants whose mothers were under 17 years of age with a random sample of babies born during the same period and at the same hospital but to older mothers. Both sets of mothers were found to have similar patterns of acute and well-child care. For adolescent mothers, use of a group practice emphasizing provider continuity significantly increased well-child visits and immunizations. The adolescent mother's late entry into prenatal care appeared to be related to a greater use of the emergency room and to inadequate well-child care. The existence of a sibling was related to inadequate well-child care for adolescents' babies but to improved levels of well-child care among older mothers' babies. These findings suggest that close monitoring of adolescent mothers with more than one child may improve the quality of medical care for their infants.

Adolescent↗