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Biomedical subjects

D L Miller

Publications and source records attributed to D L Miller.

At least 415 records · Page 23Linked to original sources

Characterization of the yeast mitochondrial locus necessary for tRNA biosynthesis: DNA sequence analysis and identification of a new transcript.

Most components necessary for the biosynthesis of mitochondrial tRNAs are coded by nuclear genes, but one mitochondrial locus other than the tRNA genes themselves is required to make functional tRNAs in the yeast Saccharomyces cerevisiae. DNA sequence analysis of this yeast mitochondrial tRNA synthesis locus is reported here. This region of mitochondrial DNA is almost exclusively A+T-rich DNA with one G+C-rich element. Despite the unusual structure of the DNA in this region, we have demonstrated that it codes for a heretofore unidentified mitochondrial transcript about 450 bases in length. Since this RNA is the only RNA encoded by the tRNA synthesis locus, it must be the active agent of the locus. This RNA could either act autonomously through RNA-RNA interactions or as part of an RNA-protein complex to effect tRNA biosynthesis.

Base Sequence↗

DNA fragments in Friend erythroleukemia cells induced by dimethyl sulfoxide.

The idea of the correlation between DNA damage caused by dimethyl sulfoxide (Me2SO) and the induction of erythrodifferentiation in murine erythroleukemia (MEL) cells needs reevaluation as a result of the hydroxyapatite chromatographic analysis of DNA from Me2SO-treated and untreated cells as a function of the time in culture. Because Me2SO causes an arrest in G1 phase and consequent delay in DNA synthesis, the valid comparison would be of the DNA samples taken from control and induced cells at the same stage of growth rather than at the same time in culture. At the same stage of growth, there is no evidence of the induction of DNA damage by Me2SO. Presumably, so-called degradation reported in the past stemmed from the fragments of DNA replication.

Animals↗

Experimental evaluation of five liver-spleen specific CT contrast agents.

We tested five experimental liver-spleen specific computed tomography (CT) contrast agents, all of which are aqueous emulsions of iodinated vegetable oils. These compounds were compared with ethiodized oil emulsion 13 (EOE-13) and with a 5% dextrose in water control. We evaluated three animal/dose level models with both histology and CT to determine the best screening method for compounds of this type. We compared a rat/high dose model, a rat/medium dose model, and a rabbit/low dose model; the best discrimination was seen with the rabbit/low dose model. Histology of liver, spleen, and lung did not correlate with the attenuation values obtained from CT. We conclude that use of CT and a rabbit/low dose model is superior for screening compounds of this type. Of the compounds tested, only one, an emulsion of ethyl monoiodostearate (compound 208E), approached the effectiveness of EOE-13.

Animals↗

Microtiter determination of measles hemagglutination inhibition antibody with filter papers.

Epidemiological studies of measles and measles immunization frequently require determination of measles antibody status. In developing countries, where venipuncture is frequently unacceptable and where refrigerated storage of serum specimens is often unavailable, microtiter techniques not requiring refrigeration are required. We developed a filter paper technique that measures measles hemagglutination inhibition antibody and meets these criteria. Comparison of separately collected venous blood and peripheral blood collected on filter paper demonstrated 97% agreement in terms of presence or absence of antibody. In 30 of 32 measles specimens, 94% of titers were the same or varied by less than 2 twofold dilutions.

Antibodies, Viral↗

Work in progress: abnormal parathyroid glands. Comparison of nonselective arterial digital arteriography, selective parathyroid arteriography, and venous digital arteriography as methods of detection.

Nonselective arterial digital arteriography (NSADA), selective parathyroid arteriography (SPA), and venous digital arteriography (VDA) were compared as methods of detecting parathyroid enlargement in 14 patients with primary hyperparathyroidism undergoing preoperative localization following unsuccessful neck surgery. All 14 had SPA and NSADA, consisting of contrast injections into the ascending aorta, innominate artery, and left subclavian artery; 7 also had VDA. Surgery was performed in 9 patients, and 2 additional glands were confirmed by fine-needle aspiration and venous sampling. Parathyroid glands could not be located in 3 patients, who were not re-explored. SPA demonstrated 11/13 abnormal glands (85%). NSADA detected 7/13 (54%), and there were 2 false positives. VDA showed 5/6 glands detected by NSADA (83%); the seventh patient did not have VDA. The overall quality of VDA was inferior to NSADA. Although NSADA and VDA are less sensitive than SPA, they are safer and easier to perform and should be the initial vascular screening procedures following unsuccessful parathyroid surgery.

Adult↗

Skin fixation of drainage and perfusion catheters. A new method.

The author describes an alternate procedure for secure skin fixation of drainage and perfusion catheters without the need for skin sutures. Catheter kinking is avoided. The catheter is unlikely to be dislodged during dressing changes, but can still be adjusted easily by the radiologist.

Adhesives↗

Percutaneous phenol sympathectomy in advanced vascular disease.

Percutaneous phenol sympathectomy has been performed under fluoroscopic or CT guidance in 37 patients with extremely advanced vascular disease of the lower extremities. The technique is simple and well tolerated by the patient with a remarkably low incidence of complications. Of the 37 patients, 14 (38%) showed objective improvement and none of the patients experienced worsening of their ischemia. Results to date suggest that this procedure provides a sympathetic blockade as effectively as surgical sympathectomy in these patients with advanced disease.

Fluoroscopy↗

Detection of hepatic metastases: comparison of EOE-13 computed tomography and scintigraphy.

Accurate detection of hepatic metastases is necessary to properly stage and follow many malignancies. Nineteen patients underwent computed tomographic (CT) examination with ethiodized oil emulsion 13 (EOE-CT) and liver scintigraphy within 1 month of an exploratory laparotomy. The sensitivity, specificity, and accuracy of these two imaging procedures were evaluated statistically. No differences were seen when the patients were scored as positive or negative for metastases. However, in a lesion-by-lesion analysis of 58 hepatic lesions, the sensitivity of EOE-CT was 69.0% and the sensitivity of scintigraphy was 32.8% (p less than 0.001). All lesions detected scintigraphy were also detected by EOE-CT. EOE-CT had a size threshold of 1.0-1.5 cm, while liver scintigraphy had a threshold of 2.5-3.0 cm. EOE-CT is a more sensitive examination for detection of small hepatic metastases than liver scintigraphy.

Contrast Media↗

Colitis cystica profunda.

The clinical, pathologic and radiologic features of colitis cystica profunda (CCP) in a 60-year-old woman are presented. This benign lesion, although rare, is usually misdiagnosed and consequently treated as a carcinoma. It should be included in the differential diagnosis of submucosal rectal lesions.

Colectomy↗

Ultrasonic assessment of cutaneous atrophy caused by intradermal corticosteroids.

A noninvasive technique of pulsed ultrasound was used to determine the long-term changes in skin thickness resulting from intradermal injections of triamcinolone acetonide (TA). Injections of 0.1 ml of either saline or a suspension containing 5 mg/ml or 10 mg/ml of TA were made at selected sites on the forearms of two human volunteers. The corticosteroid-treated sites showed a maximal decrease of 30% to 40% of the original skin thickness at 4 to 8 weeks after a single injection. A transient thinning was observed at control sites injected with saline. A greater degree of thinning was seen at the site injected with 10 mg/ml of TA as compared to the site injected with 5 mg/ml of TA. The thinning at the corticosteroid injection sites persisted at least 18 weeks after the single corticosteroid injection but had approached normal thickness values by 44 weeks following treatment. Pulsed ultrasound may be useful as a noninvasive technique for monitoring the effects of intradermally injected corticosteroids on human skin thickness and may also be useful in assessing intrinsic atrophogenic potentials of different corticosteroid molecules in human skin and the duration of action of various injectable formulations of a corticosteroid.

Atrophy↗

Reye's syndrome in children under three years old.

The National Childhood Encephalopathy Study identified 37 cases of Reye's syndrome in children aged between 2 and 36 months in a 3-year period, giving an estimated incidence in Great Britain of 0.7/100 000 children a year. The diagnostic features were neither consistently positive in these cases, nor negative in 11 others later considered not to have Reye's syndrome. The prognosis was poor; the fatality rate was 46%, and 60% of the survivors were handicapped. A surveillance scheme to investigate pathological, clinical, and epidemiological factors in this rare condition is required. This has now been set up in the UK.

Child, Preschool↗