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Biomedical subjects

S L Smith

Publications and source records attributed to S L Smith.

At least 217 records · Page 12Linked to original sources

Selected primitive reflexes in children with cerebral palsy: consistency of response.

The purpose of this study was to determine the consistency of reflex responses of subjects in varying behavioral states. The following selected primitive reflexes were examined in children with spastic quadriplegic cerebral palsy: tonic labyrinthine, asymmetrical tonic neck, symmetrical tonic neck, crossed extension, and Moro. Our hypothesis was that a subject's reflex responses would vary as a function of his behavioral state. Ten children, ages 3 to 6 years, participated in the study. Reflex responses were elicited using a specified protocol. A behavioral-state scale was defined, and the subject's behavioral state was noted before each reflex stimulus was applied. Each subject completed eight test sessions. Test sessions were videotaped with portable video equipment. Results of the study indicated a significant inverse relationship between progression on the behavioral-state scale and consistency of reflex responses; the higher the numerical rating, the less the consistency of response. Findings of our study support those who recommend optimal states for testing and indicate that caution should be used when interpreting test results based on a single examination.

Cerebral Palsy↗

Primary nonlymphoreticular malignant neoplasms of the spleen.

Primary sarcomas of the spleen are exceedingly uncommon neoplasms, approximately 90 substantiated cases having been reported. We report on six cases of primary splenic angiosarcoma and three cases of primary malignant fibrous histiocytoma of the spleen which have been seen at the Mayo Clinic during the last 51 years. In one of the cases of splenic angiosarcoma, the lesion was manifested by spontaneous rupture and hemoperitoneum; interestingly, two cases of splenic malignant fibrous histiocytoma were of the inflammatory type and showed corresponding clinical features of a systemic nature. Five patients with angiosarcoma of the spleen died of metastatic tumor within 3 years after diagnosis; one patient with splenic malignant fibrous histiocytoma is alive with metastasis 11/2 years after splenectomy. One case of splenic angiosarcoma and two of malignant fibrous histiocytoma of the spleen have been diagnosed only recently. All three patients are alive and currently tumor-free, from 3 to 7 months after diagnosis.

Adolescent↗

Taste preferences and their relation to obesity in dogs and cats.

In the laboratory situation the preferences of dogs and cats for food seem to be relatively uniform. Cats prefer fish and commercial cat food to rats. Dogs prefer beef, pork and lamb to chicken, liver and horsemeat and strongly prefer meat to cereal diets. They prefer canned meat to fresh meat, ground meat to cubed meat and cooked meat to raw meat. Canned or semimoist preparations are preferred to dry ones. Pet dogs have much more variable preferences according to their owner's subjective evaluation. A variety of factors seem to be related in an as yet unknown way to some flavor preferences of pet dogs, i.e. the dog's sex/reproductive status, weight and relationship to owners and the content of the dog's meals. The complicated interaction between (a) a pet's taste, texture and olfactory sensation, (b) its owner's perception of the pet and its preferences and (c) its physical and social environment deserves further investigation. Obesity can result from endocrinological causes such as those following ovariohysterectomy, but most cases appear to be related to owner-induced variables. In a kennel situation most, but not all, dogs can be allowed free access to palatable food without becoming obese.

Animals↗

Surgical treatment of ulcerative colitis in children.

Our finding in 100 patients indicate that elective surgical treatment of ulcerative colitis in children has a low mortality rate in contrast to emergency surgery (2.3% versus 23%). Morbidity associated with these procedures is moderate and appears to be decreasing (13%), as shown by the comparison between the experience in the 1960s and that in the 1970s. Results with the newer surgical procedures have been encouraging; 60% of patients with Brooke ileostomy have been very satisfied as compared with 90% of patients with Kock pouch and of those with rectal mucosectomy with ileoanal anastomosis. Ileorectostomy was not a satisfactory procedure in this series. Additionally, after surgical treatment, the median height percentile increased from the thirty-ninth to fifty-seventh percentile. Finally, and important, 96% of the patients in this series reported that their general health at follow-up was good to excellent and that they had minimal limitation in their activities.

Adolescent↗

Studies of hyperlipidemia in drug-induced diabetic rats by high-performance liquid chromatography.

A hyperlipidemic condition is often associated with diabetes. The possibility that specific serum lipids (i.e., individual triglycerides or cholesterol esters) may be altered in the diabetic state was investigated. Serum lipids from both controls and streptozotocin- and alloxan-treated rats were separated into approximately twenty chromtographic fractions by reversed-phase high-performance liquid chromatography; a number of individual triglycerides and cholesterol esters were identified. The methodology described allowed subtle changes in individual lipid components to be detected. Only minor variations in the cholesterol and cholesterol ester fractions were observed between the control and diabetic samples. While not uniform throughout, elevations in the triglyceride fractions occurred in the diabetics. Also, differences in triglyceride content were found to exist between the groups of streptozotocin- and alloxan-treated animals.

Alloxan↗

Sorrows of dying.

Explore the source record for details and available documents.

Attitude to Death↗

Porcine liver dihydrofolate reductase. Purification, properties, and amino acid sequence.

Porcine liver dihydrofolate reductase has been purified 18,000-fold to homogeneity. The properties of the purified enzyme were compared to those of dihydrofolate reductase from L1210 cells, the only mammalian reductase for which complete amino acid sequence data are available. The enzymes are very similar when compared on the basis of mechanism and kinetic constants, molecular weights, isoelectric points, and stimulation by salt. A comparison of the amino acid sequences of both enzymes shows an overall identity of 89%. Thus, the similarities seen in inhibitor-binding profiles of mammalian enzymes reflect the close relationship of these enzymes at the molecular level.

Amino Acid Sequence↗

The amino acid sequence of the trimethoprim-resistant dihydrofolate reductase specified in Escherichia coli by R-plasmid R67.

The amino acid sequence of a trimethoprim-resistant dihydrofolate reductase (EC 1.5.1.3) specified by the R-plasmid R67 is described. The sequence was deduced from automatic and manual sequence analysis of the intact protein, the fragments produced by cyanogen bromide cleavage, and peptides derived from the largest cyanogen bromide fragment by digestion with trypsin, Staphylococcus aureus V8 proteus, chymotrypsin, and Lysobacter enzymogenes alpha-lytic protease. The complete sequence comprises 78 residues in a single polypeptide chain of molecular weight 8444. No evidence of heterogeneity was obtained, indicating that all subunits of the native enzyme are identical. Comparison of the sequence with that of all known dihydrofolate reductases shows no significant sequence homology.

Amino Acid Sequence↗

Application of a simple high-performance liquid chromatographic method for the determination of melphalan in the presence of its hydrolysis products.

A procedure for the separation and quantitation of melphalan (L-PAM) and its hydrolysis products by high-performance liquid chromatography is described. The hydrolysis of L-PAM at 25 +/- 0.1 degrees and 41 +/- 0.1 degrees was studied between pH 3.0 and 9.0. The pattern of hydrolysis suggested that L-PAM decomposes via two consecutive pseudo first-order reactions. Pseudo first-order rate constants (k1) were determined for the disappearance of L-PAM at various pH values in buffered solutions and in a formulated product. At both temperatures L-PAM solutions were found to be most stable at low pH. Chloride ion was found to reduce the rate of hydrolysis.

Chromatography, High Pressure Liquid↗

R plasmid dihydrofolate reductase with subunit structure.

Dihydrofolate reductase, specified by the type II plasmid of a trimethoprim-resistant Escherichia coli, was purified 40-fold to homogeneity using a combination of gel filtration, DEAE-Sephacel chromatography, and hydrophobic chromatography. The final product shows a single protein band on polyacrylamide gel electrophoresis and has a specific activity of 1.0 unit/mg. The molecular weight of the purified enzyme is 36,000 as determined both by gel filtration and Ferguson analysis of polyacrylamide gel electrophoresis. In contrast, a single polypeptide with a molecular weight of 8,500 was observed on sodium dodecyl sulfate-gel electrophoresis. These experiments suggest that, unlike any bacteria or vertebrate dihydrofolate reductase previously examined, the type II R plasmid reductase is a tetramer composed of four identical subunits. A partial amino acid sequence determination shows no heterogeneity of the subunits and also no clear homology with any reductase sequence previously reported.

Amino Acid Sequence↗