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Biomedical subjects

J F Martin

Publications and source records attributed to J F Martin.

At least 271 records · Page 15Linked to original sources
PubMed1979

Thrombocytosis, circulating platelet aggregates, and neurological dysfunction.

In 12 patients whose neurological dysfunction was associated with thrombocytosis or evidence of abnormal platelet activation, or both, correction of the platelet disorder corresponded with reversal of the neurological symptoms. This suggests that platelet abnormalities may, in certain cases, produce several syndromes of neurological dysfunction, presumably as a result of obstruction of the cerebral microcirculation.

Adolescent↗
PubMed1979

Prediction of lower canine and premolar widths in the mixed dentition.

The purpose of this investigation was to determine whether, with multiple regression analysis, a more accurate method than is now available for predicting the widths of unerupted mandibular canines and premolars of mixed-dentition patients could be developed. Regression analyses were performed on data derived from 83 Caucasian subjects (42 males and 41 females) who participated in the Iowa Growth Study. Measurements were taken on plaster casts of the mandibular incisors, canines, premolars, and first molars. Measurements of the mandibular canines, premolars, and first molars were obtained from periapical radiographs taken with a long-cone technique. Newly developed regression equations for each sex had the highest correlation coefficients and smallest absolute errors of estimate when compared to previously published methods. The new equations and previous prediction methods were tested on a sample of 55 orthodontic patients (23 males and 32 females). The newly developed equations were also the most accurate method of prediction in the orthodontic patient sample.

Adolescent↗
PubMed1979

Minimal tissue concentrations of glutamate required to produce necrosis of hypothalamic neurons in newborn mice.

Groups of 4-day-old Cox Swiss albino mice were injected once subcutaneously with monosodium glutamate at several doses between 0.2 and 0.5 mg/g body weight. Glutamate, at a dose of 0.35 mg/g, produced neuronal necrosis of a very limited nature in only 60% of the animals and was defined as the minimal effective neurotoxic dose in the 4-day-old mouse. Neuronal loss was not detected in any animals treated with less than 0.35% mg/g of the amino acid whereas lesions became more extensive as the dose was increased to 0.5 mg/g. Glutamate was measured in the arcuate nucleus and plasma 0, 15, 30, 60 and 90 min after injection. These data indicated that duration of glutamate accumulation in the arcuate nucleus may be as important a variable in producing neuronal degeneration in the hypothalamus as concentration of the amino acid in that nucleus.

Animals↗
PubMed1978

Differential diagnosis of intrahepatic shadowing on ultrasound examination.

Significant sonic shadowing originating from a structure within the hepatic parenchyma is unusual and often denotes pathology. The differential diagnosis (choledocholithiasis, air in the biliary tree, calcified tissue, foreign bodies, and shadowing from normal structures) is reviewed and examples are presented.

Adult↗
PubMed1978

Evaluation of student performance in the four-year study of expanded functions for dental hygienists at the University of Iowa.

A comparison was made of the quality of selected operative and periodontal procedures completed by expanded-function dental hygiene and senior dental students. Each student group included 48 students selected from all academic quartiles of their respective classes. The evaluated operative procedures included a Class II preparation and amalgam restoration and a Class III preparation and composite restoration. Both operative procedures were completed twice, once on a patient and once on a Dentoform. The periodontal procedures were completed on patients and included a periodontal examination, a periodontal treatment plan, and one quadrant of root planing and soft tissue curettage. Three examiners independently rated each student's performance in an examiner-blind situation. Examiners judged numerous criteria for each procedure as satisfactory or unsatisfactory. In addition, an overall rating of excellent, clinically acceptable, or unacceptable was given to each procedure. Comparisons between student groups of the time required to complete procedures showed that dental students completed cavity preparations of all operative procedures and quadrants of root planing and curettage in significantly less time than did dental hygiene students. For restorations, periodontal examinations, and treatment plans, there was no significant difference between student groups in the time required to complete procedures. In general, the results of the study showed that the dental hygiene students were able to perform selected operative and periodontal procedures at a comparable level to that of senior dental students.

Clinical Competence↗
PubMed1977

Unusual echographic appearance of a Courvoisier gall bladder.

A patient who had been jaundice for more than four months was examined with diagnostic ultrasound. Ultrasound examination revealed that the patient had a solid-appearing mass in the region of the gall bladder, in addition to findings diagnostic of obstructive jaundice. A probable mass was also noted in the head of the pancreas. The clinical data and representative echographic pictures are presented to emphasize the point that sludge within the gall bladder is echogenic and appears more solid than cystic on a standard echographic examination.

Aged↗
PubMed1977

Cleavage of adenosine 5'-monophosphate during uptake by Streptomyces griseus.

Unlabeled adenine brought about a (delayed) decrease in radioactivity that had been taken up by phosphate-limited resting cells of Streptomyces griseus from [14C]adenine-labeled adenosine 5'-monophosphate (AMP). Inorganic phosphate, on the other hand, stimulated adenine uptake from AMP, presumably by activating an energy-dependent active transport mechanism. Unlabeled phosphate rapidly diluted the uptake of radioactivity from [32P]AMP. Adenine inhibited uptake of [32P]AMP but not that of [32P]orthophosphate; adenine is thought to act by inhibiting the cleavage of AMP. The uptake of 32P and 14C from double-labeled AMP showed marked differences; 32P was taken up much faster into both cells and nucleic acids. These data indicate that uptake of AMP components takes place after extracellular dephosphorylation of the nucleotide.

Adenine↗