Biomedical subjects

G R Miller

Publications and source records attributed to G R Miller.

At least 19 recordsLinked to original sources

PubMed1999

Determination of fibrosis from cryostat sections using high performance liquid chromatography: skeletal muscle.

Analysis of hydroxyproline (collagen) and pyridinoline (collagen cross-links) in biopsies prepared for routine histological evaluation with OCT compound was performed. Frozen sections (250 microm-thick) were cut from cardiac muscle, diaphragm, liver, and soleus muscle from the rat. After removal of OCT compound by rinsing, the samples were dried, weighed and hydrolyzed in 6 N HCl. A portion of the hydrolysate was analyzed for hydroxyproline using high performance liquid chromatography with collagen type I as the standard. Collagen concentrations ranged from 6.6 microg/mg dry weight (liver) to 74.7 microg/mg dry weight (diaphragm). From the remainder of the hydrolyzate, pyridinoline cross-links of collagen were separated and analyzed similarly by high performance liquid chromatography. The concentration of pyridinoline ranged from 2.6 ng/mg dry weight (liver) to 35.6 ng/mg dry weight (diaphragm). These techniques were adequate to analyze both collagen and pyridinoline (i.e. collagen cross-links) in small biopsy samples (< 1 mg dry weight) routinely used in clinical pathology. The method proved useful in the quantitation of focal fibrosis in a partially denervated rat soleus. Denervation was confirmed using fast myosin immunohistochemistry which revealed large areas of small myofibres containing fast myosin. Collagen concentration increased by five-fold and collagen cross-links by more than 7-fold consistent with fibrotic changes known to occur with denervation.

Amino Acids↗

PubMed1996

Fibrosis and intercellular collagen connections from four weeks of muscle strains.

The effect of repeated cycles of muscle strain was studied in the soleus muscle of female rats. Muscle strains were repeated 3X/week for 1 month using two different strain protocols. Striking changes, including marked variability in fiber size, evidence of degradation and regeneration, and an expanded extracellular matrix were pronounced in the fast-stretched muscles but not in the slow-stretched muscles. However, the slow-stretched muscles did contain struts of connective tissue joining adjacent myofibers. Therefore, repeated muscle strains at high strain rates produced morphological changes similar to many myopathies, including fibrosis, whereas adaptation occurred in response to the same number of strains at slow strain rates. Such diverse tissue responses have relevance to the understanding of the mechanisms of skeletal muscle dysfunction in cumulative trauma disorders and in the design of preventive actions and treatments.

Animals↗

PubMed1996

An ophthalmic drape with a built-in breathing outlet.

An ophthalmic surgical drape with an ancillary breathing outlet is described and illustrated. It is believed that this drape will supply a needed emergency feature in current ophthalmic surgical drapes that will contribute to greater safety among elderly patients and give greater assurance to the surgeon who may experience a sudden interruption in surgery caused by an unexpected respiratory problem.

Eye Diseases↗

PubMed1995

Regulation of monocyte chemoattractant protein-1 gene expression and secretion in rat pulmonary alveolar macrophages by lipopolysaccharide, tumor necrosis factor-alpha, and interleukin-1 beta.

Chemotactic cytokines coordinate the recruitment of leukocytes into the lung during pulmonary inflammation. In a previous study, we determined that rat pulmonary alveolar macrophages (PAMs) facilitate monocyte recruitment and activation in the lung during acute inflammatory lung injury, in part, through the inducible expression of monocyte chemoattractant protein-1 (MCP-1). MCP-1 is an 11 to 15 kD basic peptide that specifically mediates monocyte chemotaxis and activation. Inflammatory mediators that regulate the expression and secretion of MCP-1 by rat PAMs have not been identified. We determined that stimulation of resident rat PAMs with bacterial lipopolysaccharide (LPS), murine tumor necrosis factor-alpha, or human interleukin-1 beta resulted in the inducible expression of MCP-1 mRNA and the secretion of biologically active MCP-1. In contrast, phorbol myristate acetate, a nonphysiologic leukocyte activator, was significantly less effective in stimulating either enhanced MCP-1 mRNA expression or secretion of MCP-1. These results indicate that the expression of MCP-1 mRNA and the secretion of MCP-1 by rat PAMs are regulated by bacterial products (LPS) and inflammatory cytokines. Further, these results suggest PAMs are regulated by bacterial products (LPS) and inflammatory cytokines. Further, these results suggest that resident PAMs, through elaboration of MCP-1, may play a pivotal role in regulating recruitment and activation of monocytes in the lung during acute inflammatory lung injury.

Alkaloids↗

PubMed1995

Use of double labeling and photo CD for morphometric analysis of injured skeletal muscle.

We used computer-assisted analysis of myofiber cross-sectional areas to measure skeletal muscle responses to injury and disease. We developed a simple, inexpensive method for measuring myofiber size in human muscle samples using Kodak photo compact discs (CDs) as the image source. The photo CD serves as a permanent image storage medium and provides a high-resolution image that can be used to detect small myofibers. The use of double labeling for dystrophin and desmin allowed positive identification of both degenerating and regenerating fibers in a single biopsy specimen.

Antibodies, Monoclonal↗

PubMed1994

Adaptation of rat soleus muscles to 4 wk of intermittent strain.

The effect of repeated strains on rat soleus muscles was investigated by stretching active muscles 3 times/wk for 4 wk with two different methods of stretching. The adaptation of myofibers and noncontractile tissue was followed by histochemical techniques and computer-assisted image analysis. Muscle hypertrophy was seen in the slow-stretched muscles, which increased in mass by 13% and increased in myofiber cross-sectional area by 30%. In the fast-stretched muscle, mass increased by 10% but myofiber cross-sectional area actually decreased. This decrease in mean fiber area was the result of a population of very small fibers (population A) that coexisted with slightly smaller normal-sized fibers (population B). Fibers in population A did not have the distribution expected from atrophy compared with atrophic fibers from unloaded muscles; they were much smaller. In addition, there was a 44% increase in noncontractile tissue in the fast-stretched muscles. Thus, soleus muscles subjected to repeated strains respond differently to slow and fast stretching. Slow stretching results in typical muscle hypertrophy, whereas fast stretching produces somewhat larger muscles but with a mixture of small and normal-sized myofibers accompanied by a marked proliferation of noncontractile tissue.

Adaptation, Physiological↗

PubMed1994

Use of computer-assisted analysis for myofiber size measurements of rat soleus muscles from photographed images.

Since myofiber cross-sectional area measurements are important in describing myofiber adaptations to physiological and pathological changes, we developed a reproducible method for measuring myofiber size using fluorescent stains. Several 35-mm slides of dystrophin-, laminin-, and concanavalin A (ConA)-stained muscle sections were used to calculate myofiber cross-sectional areas and to compare different techniques and settings of an image capture system. Although variation in equipment settings did result in variation in myofiber area, the overall effect was of little practical significance (< 6%). Using midrange values for the settings of illumination, black level, and gain, reproducible quantitative data were collected and analyzed from 35-mm slides of FITC-labeled conA taken from atrophic, normal, and hypertrophic muscle samples. As expected, the atrophic muscle fibers were smaller. However, in hypertrophic muscle from compensatory overload, the fibers were composed of both large and small fibers. We found it important that the myofiber cross-sectional area measurements be expressed both in terms of average fiber areas and as frequency distribution histograms. In addition, detailed methodology of fiber area measurement must be provided.

Animals↗

PubMed1993

Expression of monocyte chemoattractant protein-1 (MCP-1) by rat alveolar macrophages during chronic lung injury.

Using a well-characterized model of bleomycin-induced pulmonary fibrosis in the rat, we determined that there was a time-dependent elaboration of monocyte chemotactic activity in bronchoalveolar lavage fluid. Northern hybridization analysis revealed markedly increased expression of rat monocyte chemoattractant protein-1 (MCP-1) mRNA in alveolar macrophages (AMs) from rats following induction of pulmonary fibrosis. Monocyte chemotactic activity was also significantly increased in conditioned media from AMs retrieved from injured rat lungs. These data suggest that one important role of AMs in the pathogenesis of chronic inflammatory lung injury and pulmonary fibrosis is the regulation of monocyte recruitment and activation within the lung secondary to secretion of monocyte chemoattractants including MCP-1.

Animals↗

PubMed1990

Interpretation of gram-stained sputa containing Moraxella (Branhamella) catarrhalis.

Sputum specimens culture positive for Moraxella (Branhamella) catarrhalis were Gram stained with three decolorizer solutions (slow, 95% ethyl alcohol; intermediate, 1:1 ratio of 95% ethyl alcohol and acetone; and fast, acetone alone) for 5, 10, 20, and 30 s. Optimal results were obtained with acetone alone after 10 s or with a 1:1 mixture of acetone and ethanol after 20 s. Inadequate decolorization of M. catarrhalis in sputa is likely if the decolorization solution and exposure time are not optimal and may contribute to underreporting of this organism.

Evaluation Studies as Topic↗

PubMed1990

Rapid, colorimetric identification of Candida albicans.

A total of 706 yeast isolates were evaluated in parallel by the Candida albicans Screen (CAS; Carr-Scarborough Microbiologicals, Inc., Stone Mountain, Ga.) test and the germ tube (GT) test in comparison with the API 20C Yeast Identification System. The CAS and GT tests correctly identified 419 of the 422 isolates of C. albicans (99.3%). Two of the false-negative reactions occurring with the CAS were with GT-negative strains of C. albicans. There were two false-positive CAS reactions involving a single strain each of C. parapsilosis and C. tropicalis. Sensitivity and specificity for both tests exceeded 99%, with positive and negative predictive values of 99 and 98%, respectively.

Candida albicans↗

PubMed1990

Parasite detection efficiencies of five stool concentration systems.

Fresh fecal material that was free of ova and parasites was pooled with 10% Formalin in a 1:4 ratio to prepare a standard specimen. Portions of 100 ml of this specimen were individually seeded with Cryptosporidium oocysts, Entamoeba coli, Entamoeba histolytica, and Giardia lamblia cysts; ova of Necator americanus; and Strongyloides larvae. Appropriate volumes of each parasite suspension were used to evaluate the Fecal Concentrator Kit (Remel, Lenexa, Kans.), Fecal Parasite Concentrator (Evergreen Scientific, Los Angeles, Calif.), Para-Pak Macro-Con (Meridian Diagnostics, Inc., Cincinnati, Ohio), and Trend FeKal CON-Trate (Trend Scientific, Inc., St. Paul, Minn.). A standardized gauze filtration method was used as the reference procedure. Tests were performed in triplicate with each individual parasite-concentrator combination, with three slides examined from each sediment. All of the systems effectively concentrated parasites compared with direct examination of unconcentrated fecal material. The Fecal Concentrator Kit provided the best overall performance. Clarity of sediment, lack of debris, and uniformity of background material were found to be important considerations for microscopic detection of parasites in concentrated specimens.

Animals↗

PubMed1989

Quality control slide for potassium hydroxide and cellufluor fungal preparations.

An opaque, water-insoluble quality control material with a skinlike microscopic appearance was prepared by inoculating melted xanthine (0.4%) agar with filamentous fungi and dispensing drops onto glass slides. After solidification of the agar, the material was rapidly cleared by 10% KOH, revealing fungal elements stained by Cellufluor reagent.

Fluorescent Dyes↗

PubMed1987

Umbelliferyl-labeled galactosaminide as an aid in identification of Candida albicans.

The initial evaluation of a fluorescence, nonmicroscopic method of rapid identification of Candida albicans is described. A total of 524 yeast isolates were evaluated in parallel by the umbelliferyl-conjugated N-acetyl-beta-D-galactosaminide (UAG) test and the germ tube (GT) test in comparison with the API 20C Yeast Identification System. The UAG test correctly identified 333 of the 334 isolates of C. albicans (99.7%), and the GT test identified 328 (98%). There were three false-positive GT reactions and five false-positive UAG reactions with 69 isolates of C. tropicalis. The sensitivity and specificity were 99 and 97%, respectively, for the UAG test and were both 98% for the GT test. The UAG test requires less than 2 h for test completion compared with 2 to 4 h for the GT test, is similar in cost, has a nonmicroscopic visual endpoint, and eliminates the health hazards of handling pooled human sera.

Acetylglucosamine↗

PubMed1980

Aftermath of osteogenesis imperfecta: the disease in adulthood.

To determine the effects of osteogenesis imperfecta and its treatment on adult life, thirty-one patients with osteogenesis imperfecta were examined at an average of nineteen years postoperatively. Seventy-two per cent of the operations that had been performed on these patients in childhood consisted of multiple osteotomies with intramedullary fixation to reduce fracture frequency and prevent bowing of the lower limbs. Only eight patients had remained non-ambulatory, seven of whom had severe long-bone deformity. Based on the study of these patients, we suggest that the severity of diaphyseal tapering and of disease are related; that scoliosis is frequent in adults with osteogenesis imperfecta; that the improvement gained at operation is maintained and enhances ambulation; and that as adults, these patients are generally very productive and socially adaptable individuals.

Adolescent↗

PubMed1979

DNA base compositions and photoreactivation capabilities of six Hansenula species.

The DNA base compositions and photoreactivable sectors of six species of Hansenula were determined. The G+C ratios revealed two groups; the first had values of 38 to 44% and the second had lower values of 32-36%. Hansenula muscicola could not repair the UV-induced damage; whereas, H. dryadoides, H. lynferdii, H. ofunaensis, H. philodendra, and H. syndowiorum could do so.

Ascomycota↗

PubMed1979

Increased production of beta-lactamase under anaerobic conditions in some strains of Escherichia coli.

A simple biological assay to detect beta-lactamase activity exhibited by selected cultures of Escherichia coli was used to test enzyme production in cells incubated aerobically and anerobically. Anaerobic incubation resulted in increased size of zones of drug inactivation by some beta-lactamase-producing strains. The beta-lactamase activity of cell lysates was determined iodometrically for aerobically and anaerobically grown cells. The specific beta-lactamase activity for anaerobically grown cells was three to five times greater than for aerobically grown cells. Beta-lactamase production was determined to be constitutive in all strains and to be plasmid mediated, as demonstrated by transfer to E. coli K-12 by conjugation.

Aerobiosis↗

PubMed1978

Silicone in ophthalmic plastic and reconstructive surgery: a review and laboratory trial.

Silicone is a material with wide application as an exogenous implant in ophthalmic surgery. Animal trials have indicated that extreme care must be taken in the use of this material in the presence of a viable eye. Acute corneal injury was seen in 10 of 14 rabbit eyes tested with a topical application of RTV silicone in the conjunctival cul-de-sac. Two of the 10 eyes demonstrated delayed healing of the corneal injury. Pretreatment with a viscous ocular lubricant, limited corneal contact time of the hardened forms, thorough and frequent corneal evaluation and prompt appropriate treatment of abnormalities are recommended for the successful use of silicone as an orbital molding material in the presence of the viable globe. For use as an orbital expander or as a stent after soft tissue socket reconstruction, despite its relative softness compared to acrylic orbital conformer, similar precautions must be observed to prevent mechanical corneal injuries.

Animals↗

PubMed1978

Intravitreal antimycotic therapy and the cure of mycotic endophthalmitis caused by a Paecilomyces lilacinus contaminated pseudophakos.

A salvaged eye in a case of mycotic endophthalmitis is reported. The case was one of eleven in the United States resulting from Luminex lens implants contaminated with amphotericin B resistant Paecilomyces lilacinus, and one of two eyes salvaged in this series of cases. The fungus, recognized 28 days after the lens was inserted, was in the anterior chamber, on the psuedophakos, and in the vitreous. The therapeutic procedures included removal of the pseudophakos, radical vitrectomy and iridectomy, and the intraocular and combined topical and systemic use of antimycotic compounds, including miconazole and thiabendazole.

Aged↗