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C Smith

Publications and source records attributed to C Smith.

At least 883 records · Page 49Linked to original sources
PubMed1985

Nuclear magnetic resonance signal assignments of purified [13C]methyl-enriched yeast phenylalanine transfer ribonucleic acid.

Yeast tRNA Phe, enriched in carbon-13 specifically at the naturally occurring methyl groups, has been produced through biosynthesis, then purified, and analyzed. Transfer RNA Phe was purified from the [13C]methyl-enriched, unfractionated tRNA that had been extracted from a methionine auxotroph of Saccharomyces cerevisiae [Agris, P. F., Kovacs, S. A. H., Smith, C., Kopper, R. H., & Schmidt, P. G. (1983) Biochemistry 22, 1402-1408]. The yeast had been grown in minimal medium supplemented with [13C]methylmethionine. Transfer RNA Phe purity and the full extent of nucleoside modification were confirmed by high-performance liquid chromatography of constituent nucleosides with simultaneous UV spectral identification and quantitation. Mass spectometry of [13C]methyl-enriched nucleosides and NMR of the tRNA indicated an enrichment of at least 70 atom %. Twelve resolved and prominent carbon-13 NMR signals from the tRNA were seen between 10 and 60 ppm. These have been assigned to 13 of the 14 naturally occurring methyl groups. However, the partially resolved signals assigned to the two 5-methylcytidines could not be assigned to their specific nucleoside positions of either 40 or 49 in the molecule. In addition, the partially resolved signals of the two methyl esters of wybutosine could not be distinguished. The methyl group found not to be enriched with 13C is bound to the ring carbon in the hypermodified nucleoside wybutosine (Y). A 13th enriched signal downfield (120.9 ppm) has been assigned to one of the two carbons added to guanosine to form the third ring in the biosynthesis of Y. The 13C enrichment of this ring carbon demonstrates its origin from the methionine methyl group.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromatography, High Pressure Liquid↗
PubMed1985

Metabolic action of prolactin in regressing prostate: independent of androgen action.

The mechanism of the observed synergistic effect of prolactin and androgen on the lateral lobe of the rat prostate is not established. The observation that prolactin alone delayed the rate of loss of weight, protein, and DNA of the lateral lobe in castrated rats has led us to question the assumption that the effect of prolactin is produced by a modification of recognized androgen-induced intracellular changes. The present study was conducted to explore whether or not the sites of prolactin action in the rat prostate coincided with those recognized as the androgen effect. Two anterior pituitaries from female donors were grafted under the right renal capsule of adult male Sprague-Dawley rats. Seven days later, bilateral orchiectomy and unilateral nephrectomy were performed in these rats. In one half of the animals, the kidney bearing the pituitary grafts was removed. In the other half, the contralateral kidney was removed. Seven days following the orchiectomy-nephrectomy, animals bearing the pituitary grafts had a higher level of serum prolactin (93 +/- 7 ng/ml, mean +/- SE) than in those without the graft (26 +/- 3 ng/ml). This condition of hyperprolactinemia was associated with the delay of castration-induced regression in the lateral prostate. The rate of protein degradation, as judged by the amount of radioactivity remaining in the tissue following a single i.v. pulse of 3H-leucine 24 hr before orchiectomy-nephrectomy, was significantly slower in the lateral prostate in graft-bearing animals than in those without grafts. However, the rate of protein synthesis, as judged by both in vitro and in vivo incorporation of 3H-leucine into the protein fractions of the prostate, was not significantly different between the two groups. Nor was the total activity of cathespin D in the lateral prostate different. These results were not consistent with parameters known as the effect mediated through androgen-controlled mechanisms. We therefore conclude that the action of prolactin in the regressing rat prostate is probably not mediated through the action of androgen.

Androgens↗
PubMed1985

Type of blunt renal injury rather than associated extravasation should determine treatment.

The significance of extravasation of dye during excretion urography in blunt renal injuries has been controversial, with some believing that extravasation, even if copious, is largely innocuous and characterized by spontaneous resolution, and others believing extravasation is an indication for surgical correction of the underlying blunt renal injury. Thirty-two patients with extravasation diagnosed on excretion urography after blunt external trauma were evaluated. Immediate surgical management of the renal injury was performed in 18 patients who had a contusion in 1, laceration in 13, rupture in 3, and pedicle injury in 1, and averaged 2.0 associated injuries per patient. Conservative management of the renal injury was performed in 14 patients who averaged 1.1 associated injuries per patient. Ten of the 14 patients had a large renal laceration splitting the kidney or disrupting a pole with extravasation and none settled to normal. The data showed that extravasation with a small laceration resolved spontaneously while extravasation with a major disruption of the kidney did not settle to normal.

Adolescent↗
PubMed1985

Management of perirenal hematoma found during laparotomy in patient with multiple injuries.

The medical records of 158 patients with perirenal hematoma found during laparotomy for intra-abdominal injury from external trauma were analyzed. Small perirenal hematomas were usually associated with renal contusions and renal artery thrombosis, while large perirenal hematomas often were present with large renal lacerations, renal ruptures, and renal pedicle injuries with rupture of the renal vein, renal artery, polar artery, or branch of the renal artery. The management of the perirenal hematoma found during laparotomy depends on the degree of the underlying renal injury and not on the size or extent of the perirenal hematoma.

Adult↗
PubMed1985

Sleep states and learning: a review of the animal literature.

Animal studies are examined in relation to the sleep-learning hypothesis. It is concluded that the data best support the idea of special periods of paradoxical sleep (PS) within the 24 hour period which are specifically involved with the learning process. The onset and duration of these PS "windows" varies with strain of animal, type of task and number of training trials per session. Alternative explanations and theories are considered.

Animals↗
PubMed1985

The successful reconstruction of thoracic tracheal defects with free periosteal grafts.

A defect was created in the thoracic trachea in nine piglets (10 kg) by excising a segment from the entire thoracic trachea proximal to the right upper lobe bronchus (3 to 3.5 cm in length) and 30% of the circumference in width (1 to 1.5 cm). The defect was repaired with a free tibial periosteal graft (FPG) and in four piglets an omental pedicle graft (OPG) was applied to the surface of the FPG. An internal tracheal splint was inserted for 12 to 16 days to support the repair and prevent air leak. The splints were removed bronchoscopically. None of the pigs developed signs of airway obstruction at any stage following the repair. Eight were killed 3 months postoperatively when four to six times their original weight. One pig died on the 18th postoperative day of unknown cause. The tracheas were removed, x-rayed, and examined grossly and histologically. The results demonstrated normal tracheal growth with absence of either stenosis, collapse, or granulation tissue. All grafts were viable, bone formation was present, and the lumenal surfaces were lined with columnar and respiratory epithelium. The OPG did not improve vascularization of the FPG. This model suggests that tracheal stenosis in children may be surgically corrected by simply incising the stenotic segment longitudinally and enlarging the tracheal diameter by inserting a FPG into the defect.

Animals↗
PubMed1985

Iron deficiency among incarcerated juvenile delinquents.

A population of 163 incarcerated delinquents (126 males and 37 females aged 12-18 years) was studied to determine the prevalence of iron deficiency and to compare hemoglobin (Hgb), mean corpuscular volume (MCV), serum ferritin (SF), and erythrocyte protoporphyrin/hemoglobin (EP/Hgb) as predictors of response to iron therapy. Thirty-two percent of females and 6% of males had SF less than or equal to 12 ng/ml; 51% of females and 24% of males had SF less than or equal to 20 ng/ml. The mean SF was 17.7 ng/ml for females and 29.2 ng/ml for males. Of the 163 subjects, 53 were at risk for iron deficiency based on SF, Hgb, EP/Hgb, or MCV criteria. Twenty-one completed treatment with iron, and nine had greater than 1 g rise in Hgb. The following tests identified responders: SF less than or equal to 12 ng/ml-5/9; SF less than or equal to 20 ng/ml-9/9; Hgb less than or equal to third percentile-4/9; Hgb less than or equal to tenth percentile-7/9; MCV less than or equal to tenth percentile-2/9; EP/Hgb greater than or equal to 3.0 micrograms/g Hgb-2/9; EP/Hgb greater than or equal to 2.5 micrograms/g Hgb-4/9. Serum ferritin less than or equal to 20 ng/ml had a false positive rate of 57%; Hgb less than or equal to tenth percentile and EP/Hgb greater than or equal to 2.5 mu g/g Hgb had no false positives. The significance of the high prevalence of iron deficiency among a population of incarcerated adolescents is not clear.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Superiority of two-dimensional measurement of aortic vessel diameter in Doppler echocardiographic estimates of left ventricular stroke volume.

Attempts to measure left ventricular stroke volume utilizing the Doppler aortic flow method have found varying correlations between invasive thermodilution and non-invasive Doppler methods. Because stroke volume is the product of the Doppler flow velocity integral (that is, the area under the flow velocity curve) and the cross-sectional area of the vessel through which blood flows, both variables are potential sources of error. Previous studies have shown that the Doppler flow velocity integral can be measured with acceptable reproducibility in the ascending aorta. Consequently, in this study an attempt was made to determine empirically the optimal method for measuring aortic diameter and area. The diameter of the ascending aorta was measured utilizing four M-mode and seven two-dimensional echocardiographic conventions. Doppler aortic flow velocity patterns were recorded with a 2.25 MHz M-mode echocardiographic transducer from the suprasternal notch by mapping the ascending aorta until aortic peak flow velocity was recorded. In 19 adult patients undergoing cardiac catheterization for clinical indications, Doppler stroke volume estimates utilizing the various echocardiographic conventions for measuring aortic root diameter and area were compared with simultaneous measurements of stroke volume by the thermodilution technique. The best correlation (r = 0.87) with thermodilution stroke volume was obtained by estimating aortic area from the two-dimensional parasternal long-axis images with the aortic dimension measured distal to the aortic sinuses from the inner to inner wall. The data were related by the equation: Thermodilution stroke volume = (0.73) X (two-dimensional Doppler stroke volume) + 17 cc.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta↗
PubMed1985

Synthesis and antifertility activity of zoapatanol analogues.

The synthesis of and guinea pig contragestational screening data for several oxepane and 3,8-dioxabicyclo[3.2.1]octane analogues of zoapatanol (1) are described and their structure-activity relationships discussed. Conversion of the 5-keto group on the nonenyl side chain of 1 into a hydroxyl function enhanced the potency. Further significant enhancement in the potency was realized with the transformation of several oxepanes into the 3,8-dioxabicyclo-[3.2.1]octane-1-acetic acid derivatives. Detailed, comparative contragestational evaluation of the three most potent compounds 9, 33, and 37 is presented, which led to the selection of 33 (ORF 13811) for further biological evaluation.

Abortifacient Agents↗
PubMed1985

Comparison of in vitro jejunal uptake of L-valine and L-lysine in the rat during maturation.

The maturational characteristics and patterns of absorption of the neutral amino acid L-valine were compared with those of the basic amino acid L-lysine using in vitro preparations of everted sacs obtained from the jejunum of suckling (2 weeks old), weanling (3 weeks old), and adolescent (6 weeks old) rats. Absorption rates determined as net transport into sac fluid and mucosal uptake (mumol/h/g protein or weight of mucosal scrapings) for both valine and lysine were greater in the suckling than in the weanling or adolescent rats. This appeared to be true for both the carrier-mediated and the diffusive processes for absorption, determined from the relationship between the observed absorption rates and the corresponding mucosal incubation medium amino acid concentrations. The major decline in rate of absorption occurred before the period of weaning. Between the period of suckling and adolescence the carrier-mediated absorption decreased by 55% for valine and by 90% for lysine, suggesting that during maturation of the jejunum the number of the carrier macromolecules responsible for absorption of valine and lysine per unit protein or weight of mucosa decreases with increasing age.

Age Factors↗
PubMed1985

Renal pedicle injury in patients with multiple injuries.

In a study of 41 patients seen over 24 years, renal pedicle injuries were associated with life-threatening multiple system injuries and the immediate surgical management of these associated injuries by general surgeons took precedence over that of the renal pedicle injury. The result was the delayed diagnosis of the renal pedicle injury with loss of function of the kidney. In an effort to improve the renal salvage rate aggressive management of renal pedicle injuries with immediate radiologic evaluation and early surgical treatment was instituted in 1969. The records of 41 renal pedicle injuries from 1959 to 1983 were evaluated. Blunt external trauma was the cause in 76%. All 41 patients had multiple system injuries, averaging 3.7 associated injuries per patient, with 35 (85%) having a laparotomy for intra-abdominal injuries and an overall mortality rate of 44%. Conservative management was followed in 13 patients, with injury to the renal artery in nine and a branch of the renal artery in four, with a renal loss/delayed nephrectomy rate of nine of nine (100%) renal artery injuries. Immediate surgical management was performed in 23 patients, with injury to the renal artery in nine, the renal artery and renal vein in four, a branch of the renal artery in two, and the renal vein in eight, with a renal salvage rate of seven of 21 (33%) renal artery and/or vein injuries. Five patients died on admission or on the operating room table. A significant renal salvage rate resulted from immediate radiologic evaluation and early surgical treatment of renal artery/vein injuries compared to zero salvage rate with conservative management.

Abdominal Injuries↗
PubMed1985

Renal trauma found during laparotomy for intra-abdominal injury.

Whether renal injury found during a laparotomy for intra-abdominal injury should have surgical or nonsurgical management is controversial. Five hundred twenty-one renal injuries were found during laparotomy for such injury in 513 patients. Blunt external trauma was the cause in 88%. A modified operating room table enabled performance of immediate intravenous pyelogram during the laparotomy. More severe degrees of renal injury (laceration, rupture, pedicle injury) were present in 135 (26%) of the renal injuries. Immediate surgical management of 102 more severe renal injuries resulted in nephrectomies in 37 (36%), delayed renal surgery in one (0.9%), and renal salvage in five of 18 (27%) main renal artery and/or vein injuries. Nonsurgical management of the remaining 23 resulted in nephrectomies in three (13%), delayed renal surgery in six (26%), total renal loss in seven of seven (100%) main renal artery injuries and an overall nephrectomy/total renal loss rate of 39%. With immediate surgical management of the more severe degrees of renal injury there was a slight increase in the salvage of kidneys and a marked decrease in delayed renal surgery and morbidity.

Abdominal Injuries↗
PubMed1985

Male genital injuries from external trauma.

External trauma from a variety of causes, some unusual and bizarre, affect the male genitalia. Certain injuries are more common, have more severe consequences, or their management may be controversial. Seventy male genital injuries from external trauma are reported and include vacuum cleaner injuries, fracture of penis and the tourniquet syndrome.

Accidents, Traffic↗
PubMed1985

Dental caries and dental treatment in the primary dentition in an industrialized South African community.

This paper reports an examination of dental caries in the primary dentition of 2-5-yr-old white children in an industrialized South African city, in 1981 and 1983. There was a decrease in dental caries prevalence over the 2-yr period accompanied by an increase in dental treatment in 3-5-yr-olds. Treatment, however, remains low. Socioeconomic status had a varying effect on the trends, but in general there was a greater reduction in dental caries in the lower socioeconomic areas.

Child, Preschool↗
PubMed1985

Assessment of the role of an immunofluorescent terminal deoxynucleotidyl transferase kit.

The laboratory use of a commercial kit for the immunofluorescent measurement of terminal deoxynucleotidyl transferase (BRL Terminal Deoxynucleotidyl Transferase Immunofluorescent Assay System) has been investigated. The precision of the assay system with stored patient material and its performance with regard to ease of microscopic examination were assessed. The intensity of the fluorescence obtained was found to vary. However, the precision of the assay system on fixed slides stored at -30 degrees C was satisfactory; the method simple, and results obtainable in a relatively short space of time.

Bone Marrow↗