Biomedical subjects
D Miller
Publications and source records attributed to D Miller.
Increase in rabbit corneal curvature by heated ring application.
This study demonstrated that increases of corneal curvature in living rabbits could be induced through the application of heated brass rings. The peak increase averaged 10.5 D in a series of 19 eyes, as compared to the nontreated fellow eyes. This change tended to be transient, was not prolonged with the use of steroids locally, and tended to return to normal within two to three weeks. The mechanism of this change involved the creation of a rigid desiccated pseudo-limbus holding the cornea in the configuration of increased curvature. With the rehydration of the desiccated area, the cornea then reassumes its pretreated curvature and configuration. The application of the rings heated to about 98C produced a very low incidence of corneal ulceration. Further experiments showed that burn ulceration is a temperature-dependent phenomenon rarely found with application of heat less than 110C.
Ophthalmometry without patient fixation.
Because of the asphericity of the cornea, proper ophthalmometry requires the visual axis of the eye, the optical axis of the ophthalmometer, and the corneal apex to be coincident. The animal subject and the human patient cannot always direct their visual axis to the axis of the instrument. This paper describes the attachment of a photographer's tripod pan arm to the Haag Streit ophthalmometer and the method devised, which allows accurate corneal curvature measurement in cases of nonfixating subjects.
A system for slit-lamp polaroid photography.
A system is described in which a SX-70, Alpha Model II, Polaroid, single lens reflex camera, and photoflash unit can be quickly and sturdily mounted to a slit lamp. Such a system can take sharp anterior segment prints of the eye at all slit-lamp magnifications, with white light and in the flourescein mode. The heart of the unit is the modification of an assembly initially designed to attach the camera to a light microscope. The small flash unit and power supply were designed specifically for slit lamp usage. Examples of "instant" photos of the anterior segment at different magnifications are presented.
The effect of corneal stretch on the endothelium.
A model has been developed to describe the phenomenon of corneal stretch. In the model situation, suction is applied to the corneal surface of the bovine eye. The newly induced corneal shape forces the endothelial layer to stretch and sometimes to tear apart in places. This same type of stretch can be induced when a soft lens is placed on the bovine cornea. We postulate that drying of the soft lens produces a local flow of water from the cornea at the lens periphery with a secondary bowing of the central cornea. These results are confirmed by a decrease in the peripheral keratometry readings with an increase in the central keratometry measurements. The resultant deformation increases the posterior surface area of the cornea thus stretching the endothelium. These reversible/irreversible changes are time/drying dependent. The endothelial effects of corneal bending, as in cataract extraction, radial keratotomy and tight suture placement were investigated. As expected, when these techniques stretch the cornea, the result is endothelial changes.
Use of sodium hyaluronate in human IOL implantation.
Intraocular lenses (IOLs) were implanted into each eye of 20 patients. In one eye of each patient, sodium hyaluronate [Healon] was used to maintain the anterior chamber and coat the corneal endothelium during surgery. Postoperative results were compared to the other eye of the 20 patients receiving IOL implants in the conventional way. Endothelial cell loss averaged 18% in the sodium hyaluronate treated eyes vs. a 54% endothelial cell loss in the control group.
Flow cytometric analysis of bone marrow in a patient with resistant neuroblastoma.
Using flow cytometric analysis, we followed changes in a patient's bone marrow which was infiltrated with cells resistant to chemotherapy. Samples taken prior to, during, and after treatment with dianhydrogalactitol (2 days), cytosine arabinoside and hydroxyurea (2 days), and Adriamycin (2 days) contained an aneuploid population of cells which exhibited changes in ploidy, viability, and distribution in cell cycle compartment. The restricted changes in cell ploidy and viability of tumor cells encountered as well as limited increases in S phase on day 4 and G2 phase on day 6 with a rebound on day 9 of G1 phase cells suggest the tumor to be sensitive to dianhydrogalactitol but not to the other agents used.
Subpopulations of human T lymphocytes. VI. Analysis of cell markers in acute lymphoblastic leukemia with special reference to Fc receptor expression on E-rosette-forming blasts.
A variety of surface markers, terminal deoxynucleotidyl transferase (TdT) activity, morphologic appearance, and cytochemical composition were studied in a group of 16 patients (13 children, 3 adults) with acute lymphoblastic leukemia (ALL). In 9 children, no surface markers were detected on lymphoblasts (null-type ALL). Leukemic blasts of 4 children formed E-rosettes. These E-rosette-forming blasts from 3 adult patients with ALL, were studied for the presence of Fc receptors. Of the leukemic blasts from these 7 patients, 2--76% expressed receptors for IgG Fc. Only 3 of 7 patients showed 9--42% receptors for IgM Fc. In addition, complement receptors were investigated in 6 of those 7 patients with T-cell ALL. Complement receptors were detected on 9--70% of the E rosette forming blasts from all 6 patients. TdT activity was elevated in T-cell ALL and in children with null-type ALL. The heterogeneity of Fc receptor expression on leukemic blasts in these patients demonstrates a malignant proliferation of T cells in different stages of differentiation or maturation. This observation might be helpful in subclassifying T-cell leukemias with regard to prognosis and the response to therapy.
Prolonged mechanically assisted ventilation. An analysis of outcome and charges.
Mechanically assisted ventilation is frequently used, but there are little data regarding cost and long-term outcome. Therefore, all patients who required mechanical ventilation for 48 hours or more were studied, their hospitalization charges analyzed, and the survivors observed for two years after discharge. The mean charge for the hospitalization was $12,300, compared with $1,600 for all other hospitalized patients. Although the overall mortality at discharge was 56%, the patients with pulmonary disease had the lowest mortality (29%) with the lowest cost at time of discharge. The mortality for the postoperative and miscellaneous medical group of patients demonstrated no significant increase during the period following discharge, unlike the cardiac and pulmonary groups, whose mortality increased each year of follow-up. Hospitalization for these patients was eight times as costly as for all other hospitalized patients during the same 12 months, with a two-year mortality of 72%.
Gastroduodenitis. A broader concept of peptic ulcer disease.
To evaluate the frequency and type of gastroduodenal mucosal inflammatory changes in patients with symptomatic acid peptic disease and nonulcer dyspepsia, 100 patients with gastrointestinal symptoms indicative of acid peptic disease or dyspepsia and 10 control subjects were clinically evaluated and underwent radiographic, endoscopic, and biopsy studies of the stomach and duodenum. Clinical evaluation revealed that of the 100 patients, 61% had classic and 39% had atypical manifestations of acid peptic (ulcer) disease. Endoscopic and histologic evaluation revealed that 25 patients had peptic ulcer craters, 86-90% of whom had associated gastroduodenitis. Thirty-nine patients had acute and 20 patients had chronic gastroduodenitis without ulcer crater. Twelve symptomatic patients had no histologic changes in the gastroduodenal mucosa. Two of the ten control subjects had mild gastritis. In the 61% of the patients with classic manifestations of peptic ulcer disease, we could not clinically distinguish the 24 patients with craters, (40% of the classic group) from the 25 patients with acute gastroduodenitis without craters (41% of the classic group). As a result of this study of our group of patients, we believe that gastroduodenitis can be symptomatic and may present with the same manifestations as peptic ulcer crater. Further study will be required to determine whether gastroduodenitis is an independent entity or part of the spectrum of acid peptic (ulcer) disease.
The tRNAAGYSer and tRNACGYArg genes from a gene cluster in yeast mitochondrial DNA.
Yeast mitochondrial DNA-pBR322 recombinant DNA molecules screened for rRNA genes were used as a source of DNA for mitochondrial tRNA gene sequence analysis. We report here the sequences of yeast mitochondrial tRNA genes coding for a tRNAAGYSer and a tRNACGYArg. The tRNAAGYSer sequence deduced from the gene is the first reported sequence of a yeast tRNAAGYSer. It is also the second yeast mitochondrial tRNASer gene to be sequenced, and demonstrates unequivocally the presence of mitochondrial encoded serine tRNA isoacceptors. The tRNACGYArg sequence deduced from the gene is the most AT-rich (82%) tRNA sequence ever reported. Whereas all the mitochondrial genes sequenced to date exist singly on the genome and are separated by long stretches of AT-rich DNA, the tRNAACYSer and tRNAcgyarg genes exist in tandem, separated by only 3 bp. This gene arrangement strongly suggests that mitochondrial tRNA genes may be transcribed into multicistronic precursors.
Use of hydralazine for intractable cardiac failure in childhood.
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Use of Na-hyaluronate in anterior segment eye surgery.
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The Neurosurgical Society of Australasia: the first forty years.
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Clinical tear analysis using laser diffraction.
A diagnostic method has been developed to analyze tear specimens from patients with red eyes, using the technique of laser diffraction. After proper tear sample preparation, presence of a diffraction halo produced by the tear specimen indicates presence of an external ocular inflammation and helps rule out such conditions as glaucoma, iritis and episcleritis. Measurement of the size of the halo pattern may also be used to give information as to the concentration of cells in the tear sample.
Intervention study in high school students with elevated blood pressures. Dietary experiment with polyunsaturated fatty acids.
A blood pressure-lowering effect of increased prostaglandin synthesis via polyunsaturated fatty acids has been demonstrated in animal experiments. To our knowledge, for the first time an attempt was made to lower elevated blood pressures in adolescents (age 15-18 years) through a diet enriched in polyunsaturated fatty acids. This community-based dietary trial involved 30 students in the diet group and 20 students in the control group without any dietary intervention. Within 6 weeks the systolic blood pressure decreased by almost 11 mm Hg in the diet group and by 6 mm Hg in the control group. Diastolic blood pressure fell by 2 and 1 mm Hg, respectively. The effect on blood pressure was markedly different in normal weight adolescents. Systolic blood pressure in the diet group decreased by 14 mm Hg but only by 5 mm Hg in the control group. Diastolic blood pressure levels fell by 4 mm Hg in the diet group and increased by 4 mm Hg in the control group. Unfortunately, the numbers in these two comparison groups were rather small. The majority (70%) of adolescents with high blood pressure was overweight (greater than or equal to 20% above normal weight). However, for the small group of normal weight adolescents, the diet enriched with polyunsaturated fatty acids may be suitable to reduce elevated blood pressure levels.