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Biomedical subjects

R B Miller

Publications and source records attributed to R B Miller.

At least 91 records · Page 5Linked to original sources

Scanning electron microscopy of bovine corneas irradiated with sun lamps and challenge exposed with Moraxella bovis.

Effects of UV radiation and irradiation followed by challenge exposure with Moraxella bovis on the corneal epithelium were studied in 6 calves by scanning electron microscopy. After UV irradiation, the number of dark cells comprising the surface epithelium increased. Many epithelial cells were in various states of degeneration and were characterized initially by large round nuclei, whereas sloughing and peeling were characteristic of the last degenerative stage. All M bovis-infected irradiated eyes had large numbers of degenerating cells, deep epithelial defects, fibrin strands, surface inflammatory cells, and debris. A few M bovis organisms were randomly attached to the cornea before visible ulceration. There were many inflammatory cells between the ulcerated corneal epithelium and adjacent nonulcerated epithelium. Epithelial cells at the margin of the ulcer appeared swollen. Light, dark, and intermediate epithelial cell types could not be distinguished peripheral to the ulcer.

Animals↗

Haemophilus somnus: investigations of its potential role in bovine mastitis.

Mammary glands of 6 lactating Holstein cows were inoculated with Haemophilus somnus strain 43826. Three cows developed chronic mastitis and shed bacteria for up to 1 year. Three cows developed acute gangrenous mastitis, with evidence of bacteremia and endotoxemia. Cows with gangrenous mastitis had lower somatic cell counts early after inoculation in affected quarter secretions compared with those in cows that developed chronic mastitis. Cows with gangrenous mastitis developed hypocalcemia, hypoalbuminemia, azotemia, hyperbilirubinemia, mildly increased serum aspartate aminotransferase and creatine kinase activity, and a marked neutropenia with a degenerative left shift. Histopathologic examination of gangrenous quarters revealed edema, necrosis, and vascular thrombosis with few inflammatory cells. A limited survey failed to recover H somnus from dairy cows with clinical mastitis or from mammary secretions from 41 beef cattle at an abattoir.

Animals↗

Contact thermal burns of the cornea from electric curling irons.

We treated four patients with corneal burns resulting from mishaps while using electric curling irons. In all cases, the burns were symptomatic with blurred vision, tearing, pain, and photophobia. Injury was limited to the corneal epithelium, and management included debridement, topical antibiotics, cycloplegia, and pressure patching. Burns resolved completely within 48 hours after debridement and patching.

Adult↗

Bovine abortion and neonatal death associated with Ureaplasma diversum.

Ureaplasma diversum was isolated from the lungs and/or stomach fluid and placentas of five aborted bovine fetuses and four newborn calves. All isolates were serotype D48. Placentitis was observed in all instances in which the placenta was examined. Gross lesions consisted of focal or diffuse reddening of the chorioallantois and amnion and thickening of the amnion. Microscopically there were fibrosis, edema and inflammation of the amnion. Microscopic lesions in the lung consisted of diffuse pneumonitis with thickening of the alveolar walls and in some cases peribronchiolar lymphoid accumulations. Macrophages and granulocytes were present in the alveoli. Inoculation of the vulva of a virgin heifer with one of the isolates from a fetal lung produced hyperemia and profuse purulent discharge with slight granularity.

Journal Article↗

Conditioning of inspired air by a hygroscopic condenser humidifier.

The heat and water content of inspired air is critical to the pulmonary viability of patients with artificial airways. By continuously measuring gas conditions in the ventilator circuits of 6 adult ICU patients, we studied the heat and water reclaimed from expired air by a hygroscopic condenser humidifier (HCH) in the circuit. Temperature, partial pressure of water vapor (PH2O) and relative humidity (RH) were determined at the tracheal outlet of the endotracheal tube. The HCH was 63% efficient; the end-inspiratory gas delivered to the patients averaged 30.9 degrees C with a PH2O of 32.5 mm Hg and an RH of 97.3% or, equivalently, an RH of 69.2% referenced to 37 degrees C. These values are lower than those reported in the literature for gas in the trachea during nose breathing of ambient air, but greater than the values reported for mouth breathing of ambient air.

Air↗

Use of triphenylmethyl (trityl) amino protecting group in the synthesis of ketomethylene analogues of peptides.

The Grignard reagents of 2-(2-bromoethyl)-1,3-dioxane and 2-(2-bromoethyl)-1,3-dioxolane readily reacted with the 2-thiopyridyl ester of N-triphenylmethyl-L-leucine to give the ketone adducts 2-[3-oxo-4(S)-(triphenylmethyl) amino-6-methylheptyl]-1,3-dioxane (8a) and 2-[3-oxo-4(S)-(triphenylmethyl) amino-6-methylheptyl]-1,3-dioxolane (8b) in near quantitative yield. When 1 equiv. of the Grignard reagent of 2-(2-bromoethyl)-1,3 dioxane was used, the desired ketone adduct 8a was formed slowly but quantitatively. In contrast, when 2 equiv. of the Grignard reagent were used, the formation of ketone 8a was instantaneous. The triphenylmethyl protecting group was easily removed from 8a using dilute acid to give the amino ketone 2-[3-oxo-4(S)-amino-6-methylheptyl]-1,3-dioxane oxalate salt (9). This material served as a useful intermediate in the synthesis of the ketomethylene analogues of the peptides, Z-Pro-Leu-Gly-OH and Leu-Gly-Val-Phe-OCH3.

Ketones↗

Primary cardiac granular cell tumor in a dog.

The histological, histochemical, and ultrastructural features of a granular cell tumor in the wall of the right atrium of the heart in a nine-year-old dog are described. The histologic appearance of the mass varied from areas of spindle-shaped cells to sheets of globoid cells with foamy granular cytoplasm. The globoid neoplastic cells contained numerous cytoplasmic granules which were variably positive to periodic acid-Schiff staining, with and without disastase digestion. Ultrastructurally, the globoid cells had numerous various-sized, heterogeneous lysosomes with pleomorphic content. A granular cell tumor originating in the heart has not been reported previously in animals. The support for a neural origin of these tumors by the recent identification of several nervous tissue specific proteins in their granular cells is discussed.

Animals↗

Rehabilitation of the paralyzed lower lip.

There is a continuum of smiles from the one of the reserved Mona Lisa to a full dental smile where there is maximal exposure of teeth and full triggering of all the major and minor smile muscles. The ramus mandibularis paralysis is more obviously noted in the full dental smile. The ramus mandibularis paralysis is best corrected through a technique of wedge resection of the lower lip with a segmental sling to the nasolabila groove.

Facial Expression↗

The effects of Ureplasma diversum inoculated into the amniotic cavity in cows.

Ureaplasma diversum was inoculated into the amniotic cavity in four cows. Two calves were aborted and two were born alive. One of the latter died shortly after birth and the other was killed. The cows remained clinically normal except that three retained their placenta. On microscopic examination there was a severe placentitis and an alveolitis was present in the lungs of all calves. Ureaplasma was recovered from four placentas and three lungs. Cows remained infected for a maximum of 132 days following inoculation and the organism was recovered in urine and vulvar swabs for a maximum of 17 and 60 days respectively following expulsion of the calf. Ureaplasma diversum has been isolated from natural cases of abortion with similar lesions. This experiment strongly supports a causal relationship between abortion, birth of calves with pneumonia and U. diversum infection.

Journal Article↗

Effect of hypothermic perfusion on corneal endothelial morphology.

The effect of moderate in-vivo hypothermic perfusion on corneal endothelial integrity was studied in the cat. Eleven cats underwent in-vivo anterior chamber perfusion for 30 minutes with either normothermic (23 degrees C) or hypothermic (5 degrees C) perfusate. Corneas were then evaluated clinically (biomicroscopy), functionally (vital staining), and morphologically (scanning electron microscopy) for changes attributable to hypothermic perfusion. All 3 modes of evaluation suggested no difference in corneal endothelial integrity under the 2 experimental perfusion conditions. At the clinical and scanning electron microscope levels hypothermic perfusion does not show any effects on the corneal endothelium. Regional hypothermia is of theoretical and potential utility in procedures involving prolonged intraocular perfusion.

Animals↗

Hemophilus somnus in the reproductive tracts of slaughtered cows: location and frequency of isolations and lesions.

One hundred bovine female reproductive tracts were examined for the presence of Hemophilus somnus, and fifty were examined for gross and microscopic lesions. H. somnus was isolated from eight of 100 tracts. The isolation was made from the vagina in seven cows. Of 24 tracts in which the major vestibular gland was sampled, three were positive at this site, and two of these three also had the organism isolated from the vagina. Further investigations into the role of the major vestibular gland as a source for continuing infections of the reproductive tract of cattle were indicated. In this investigation, H. somnus was as likely to be found in a region without lesions as one with lesions.

Abattoirs↗

The effects of intra-amniotic inoculation of Hemophilus somnus on the bovine fetus and dam.

The injection of three strains of Hemophilus somnus into the amniotic cavity of pregnant cows produced death of the fetus and abortion followed by retention of the placenta. H. somnus was recovered readily from the placenta but less so from the fetus. Lesions in the placenta were conspicuous in arteries and somewhat resembled vascular lesions observed in septicemic H. somnus. H. somnus was recovered from the maternal circulation in several infected cows. Clinical signs included fever, irritability, lameness, and vulvar discharge, but no cows died. The organism was recovered for prolonged periods in cervicovaginal mucus and urine after remission of clinical signs. This may be a means of spread of infection.

Abortion, Veterinary↗

Effects of Hemophilus somnus on the pregnant bovine reproductive tract and conceptus following cervical infusion.

Three strains of Hemophilus somnus were infused into the posterior cervix of six pregnant cows. The organism persisted in the cervicovaginal region for eight to 87 days, and at parturition H. somnus was isolated from chorioallantois in four of six cows; placentitis developed, and fetal membranes were retained. All calves were born alive and no H. somnus was recovered from them. One cow died 14 days after parturition. The death was attributed to severe necrotizing metritis; H. somnus was not isolated from the uterus at death, but was isolated from the placenta at parturition and cervicovaginal mucus two days days later.

Animals↗

Frequency of jowl abscesses in feeder and market swine exposed to group E streptococci as nursing pigs.

Weaning and isolation were evaluated as management methods in controlling streptococcic lymphadenitis of swine. Nursing pigs in 3 experiments were exposed to group E streptococcus (GES) by contact with their GES-inoculated dams or other GES-inoculated pen mates. The exposed pigs were either weaned and isolated when 5, 6, or 8 weeks old or left in contact with the inoculated swine until 14 to 32 weeks old when all were necropsied. Abscesses were not recognized in 13 weaned or 7 unweaned pigs necropsied at 14 to 15 weeks of age, but GES was isolated from mandibular lymph nodes of 4 of the 7 unweaned pigs. Abscesses were recognized in 1 of 49 unweaned and 4 of 53 weaned swine when examined at market weight (24 or 32 weeks of age). In the 3rd experiment, 10 of 11 inoculated sows, one of 33 unweaned, and 11 of 25 weaned swine had serum titers greater than 4 to GES in a microtitration agglutination test.

Abscess↗