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Biomedical subjects

P G Miller

Publications and source records attributed to P G Miller.

At least 19 recordsLinked to original sources
PubMed2001

Dysphagia in a patient with Wegener's granulomatosis: case report.

Wegener's Granulomatosis is an autoimmune disease characterized by a rare form of systemic vasculitis which can result in damage to vital organs of the body by restricting blood flow to those organs. It affects various systems of the body including the central nervous system and cranial nerves. To our knowledge, there are no previous described cases of oropharyngeal dysphagia in these patients. This paper describes and discusses a case of oropharyngeal dysphagia in a patient with Wegener's Granulomatosis.

Aged↗
PubMed1995

Isolation, culture, and characterization of equine oviduct epithelial cells in vitro.

Oviduct epithelial cells (OEC) increasingly are used to support embryonic development and to study gamete interactions with the female reproductive tract in vitro. This series of experiments was designed to characterize monolayers derived from oviduct epithelium. Epithelial cells harvested from the isthmus and ampulla of the oviducts of five estrous mares were cultured with or without the basal lamina extract, Matrigel. Within each group OEC were cultured in the presence of either estradiol-17 beta or a carrier control. All groups were subcultured three times. Epithelial cell morphology and function were examined by microscopy, analysis of secreted proteins, and immunocytochemistry. Epithelial cells attached more rapidly and reached confluence sooner when cultured on Matrigel than in uncoated wells. Cells showed variable evidence of ciliary activity up to 12 days in primary culture. Cells grown on Matrigel had a more polarized appearance in primary culture than those in uncoated wells, although no morphologic difference between anatomic site of origin or between steroid treated groups was noted. Anatomic site of origin had no effect, and steroid treatment had minimal effects, on patterns of secreted proteins. However, some differences were noted in protein secretion between cells grown with or without Matrigel. These data suggest that culture substrate may affect structure and function of OEC monolayers.

Animals↗
PubMed1995

Most dorsal root ganglion neurons of the adult rat survive nerve crush injury.

Severe crush of the rat sciatic nerve does not result in any significant cell death among motor neurons (Swett et al., 1991a). The present study reports on the survival of the dorsal root ganglion (DRG) neurons in the same experiments. From 15 to 187 days after crush of the left sciatic nerve, the common peroneal or sural nerve was cut and labeled distal to the injury with a mixture of horseradish peroxidase (HRP) and its wheatgerm agglutinin conjugate (WGA:HRP). In other cases, the crush injury was made far enough distally on a peroneal or sural branch to permit labeling several millimeters proximal to the injury. The procedures for reconstructing the regenerated DRG neuron populations were identical to those used in an earlier study describing the normal sciatic DRG neuron populations in the rat (Swett et al., 1991b). The normal peroneal nerve contains 2699 +/- 557 DRG neurons. When the peroneal nerve was crushed near its point of origin from the sciatic and labeled 10 mm distal to the injury, 2186 +/- 163 DRG neurons were counted, suggesting a decrease of about 19% (p < 0.01). However, when the entire sciatic nerve was crushed, distal labeling of the peroneal nerve revealed a mean number of 2578 +/- 291 DRG neurons, an insignificant reduction (p > 0.2). When the peroneal nerve was labeled proximal to a peroneal crush site, a similar number of DRG neurons (2563 +/- 412) was counted. Results following sural nerve crush were similar. The sural nerve normally contains 1675 +/- 316 DRG neurons. When the nerve was labeled distal to the injury, 1558 +/- 64 DRG neurons were counted--a number almost identical to that found (1529 +/- 240) when this nerve was labeled proximal to the injury. The results demonstrate that within 6 months of severe crush injury of the rat sciatic nerve, the vast majority of DRG neurons survive and regenerate new axons distally beyond the injury site, presumably to reinnervate their original targets.

Animals↗
PubMed1994

A subpopulation of morphologically normal, motile spermatozoa attach to equine oviductal epithelial cell monolayers.

Attachment of spermatozoa to oviductal epithelial cells (OEC) may be a prefertilization event in some species. We tested the hypothesis that spermatozoa that attach to equine OEC monolayers are a selected subpopulation of the initial inseminate, containing a higher proportion of morphologically normal, motile cells than the inseminate. Washed stallion spermatozoa were cocultured with monolayers of OEC or monolayers of Vero cells, and controls were incubated in wells coated with basement membrane extract (Matrigel [Mgel]) or in plastic (uncoated) wells. Unattached spermatozoa were removed by rinsing at 0.5 h of coculture. Spermatozoa that attached and subsequently released were collected at 3 h. Total cell numbers and percentages of motile, viable, and morphologically normal spermatozoa were counted in the initial inseminate, in plastic control wells, and in the coculture supernatants after incubation. The percentages of motile and morphologically normal spermatozoa attached to OEC, Mgel control wells, and Vero cell cocultures were measured in situ after 0.5 and 3 h of incubation. Populations of spermatozoa that attached to either OEC or Mgel had higher motility and those attached to OEC contained a higher percentage of normal spermatozoa than the inseminate. Compared to the inseminate, populations that did not attach had similar viability and contained a similar percentage of normal spermatozoa, but had lower motility. Spermatozoal populations released (at 3 h) were similar in percentage of normal morphology to those that were attached, but exhibited reduced motility and viability when compared to the inseminate. We noted no difference in motility or morphology between populations of spermatozoa attached to OEC and those attached to Vero cell monolayers.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

In vitro development of day 2 embryos obtained from young, fertile mares and aged, subfertile mares.

This study was designed to investigate the development of day 2 embryos obtained from young and aged mares, co-cultured with oviductal epithelial cells obtained from mares in each age group in a 2 x 2 crossover design. Young, fertile mares (n = 19; 2-7 years of age) and aged, subfertile, mares (n = 16; 17-24 years of age) were used as embryo and oviductal epithelial cell donors. Embryos (n = 37) were collected from the oviducts 2 days after ovulation and were paired (embryos obtained from young mares with embryos obtained from aged mares) so that eight pairs were co-cultured with young mare oviductal epithelial cells and eight pairs were co-cultured with aged mare oviductal epithelial cells. Five additional embryos obtained from young mares were co-cultured with oviductal epithelial cells from either young mares or aged mares but were not paired. Embryos were co-cultured for 7 days at 38.5 degrees C in 5% CO2 or until morphological degeneration was detected. The proportions of paired embryos that reached the blastocyst stage were similar for embryos obtained from young mares and embryos obtained from aged mares after co-culture with oviductal epithelial cells from young mares (6 of 8 versus 5 of 8) or from aged mares (6 of 8 versus 5 of 8), respectively. Although the overall rate of development of embryos to blastocyst from both young mares and aged mares was similar, blastocysts developing from embryos obtained from aged mares were inferior to blastocysts obtained from young mares in terms of number of cell nuclei, quality score, and diameter at day 7.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1993

Tropomodulin is associated with the free (pointed) ends of the thin filaments in rat skeletal muscle.

The length and spatial organization of thin filaments in skeletal muscle sarcomeres are precisely maintained and are essential for efficient muscle contraction. While the major structural components of skeletal muscle sarcomeres have been well characterized, the mechanisms that regulate thin filament length and spatial organization are not well understood. Tropomodulin is a new, 40.6-kD tropomyosin-binding protein from the human erythrocyte membrane skeleton that binds to one end of erythrocyte tropomyosin and blocks head-to-tail association of tropomyosin molecules along actin filaments. Here we show that rat psoas skeletal muscle contains tropomodulin based on immunoreactivity, identical apparent mobility on SDS gels, and ability to bind muscle tropomyosin. Results from immunofluorescence labeling of isolated myofibrils at resting and stretched lengths using anti-erythrocyte tropomodulin antibodies indicate that tropomodulin is localized at or near the free (pointed) ends of the thin filaments; this localization is not dependent on the presence of myosin thick filaments. Immunoblotting of supernatants and pellets obtained after extraction of myosin from myofibrils also indicates that tropomodulin remains associated with the thin filaments. 1.2-1.6 copies of muscle tropomodulin are present per thin filament in myofibrils, supporting the possibility that one or two tropomodulin molecules may be associated with the two terminal tropomyosin molecules at the pointed end of each thin filament. Although a number of proteins are associated with the barbed ends of the thin filaments at the Z disc, tropomodulin is the first protein to be specifically located at or near the pointed ends of the thin filaments. We propose that tropomodulin may cap the tropomyosin polymers at the pointed end of the thin filament and play a role in regulating thin filament length.

Actin Cytoskeleton↗
PubMed1993

Development to blastocysts of one- to two-cell equine embryos after coculture with uterine tubal epithelial cells.

Development of 1- to 2-cell in vivo fertilized equine embryos cultured with or without uterine tubal epithelial cells (UTEC) was studied. One- to 2-cell embryos (n = 26) were collected surgically from the uterine tubes of pony mares 1 day after ovulation. Four- to 8-cell embryos (n = 9) were collected 2 days after ovulation. Presumptive zygotes and 2-cell embryos were cultured with (n = 17) or without (n = 9) UTEC, and all 4- to 8-cell embryos were cocultured with UTEC as positive controls. Uterine tubal epithelial cells were used as cell suspensions within 2 weeks after initiation of cultures. Embryos were cultured to blastocysts or until the embryo had morphologic degeneration. Six presumptive zygotes failed to cleave in vitro. Development to blastocysts of 1-cell (4 of 11) and 2-cell (2 of 6) embryos cocultured with UTEC was similar. Coculture of 1- to 2-cell embryos with UTEC significantly (P = 0.05) improved development to blastocysts, compared with culture in medium alone (35 vs 0%, respectively); however, development to blastocysts of 1- to 2-cell embryos cocultured with UTEC was less (P < 0.025) than that of 4- to 8-cell embryos cocultured with UTEC (35 vs 89%, respectively).

Analysis of Variance↗
PubMed1992

Survival of equine embryos co-cultured with equine oviductal epithelium from the four- to eight-cell to the blastocyst stage after transfer to synchronous recipient mares.

In this study we examined the ability of equine oviductal epithelial cells (OEC) to support the development of four- to eight-cell equine embryos in vitro and investigated the ability of co-cultured embryos to continue normal development after transfer to synchronous recipient mares. Equine embryos obtained at Day 2 after ovulation were cultured with or without OEC for 5 days. Those OEC co-cultured embryos that reached the blastocyst stage and embryos recovered from the uterus at Day 7 were surgically transferred to synchronous recipient mares. Co-culture with OEC improved (P < 0.01) development of four- to eight-cell embryos to blastocysts compared to medium alone (11/15 vs 0/6) during 5 days in vitro. Embryos co-cultured with OEC were smaller (P < 0.05) and more delayed in development than Day-7 uterine blastocysts. There was no difference in the Day-30 survival rate of co-cultured blastocysts (3/8) or Day-7 uterine blastocysts (5/8) after transfer to recipient mares. These results indicate that co-culture with OEC can support development of four- to eight-cell equine embryos in vitro and that co-cultured embryos can continue normal development after transfer to recipient mares.

Journal Article↗
PubMed1992

Influence of exogenous progesterone on early embryonic development in the mare.

The influence of exogenous progesterone on the development of equine oviductal embryos was determined based upon the recovery of Day-7 uterine blastocysts from treated mares (n=13) that were given 450 mg progesterone daily between Days 0 and 6 and from untreated control mares (n=13). Daily administration of 450 mg progesterone in oil significantly (P<0.02) increased serum progesterone concentrations in the treated mares. There was no significant difference in the recovery rate of Day-7 embryos between treated and control mares (8/13 versus 6/13, respectively). Embryonic development, assessed by morphologic evaluation, embryo diameter, and number of cell nuclei was not significantly different for embryos from treated and from control mares. The results of this study indicate that administration of progesterone beginning on the day of ovulation does not affect the embryo recovery rate or embryonic development, based on evaluation of uterine blastocysts recovered at Day 7 after ovulation.

Journal Article↗
PubMed1991

All peroneal motoneurons of the rat survive crush injury but some fail to reinnervate their original targets.

This is a quantitative study of the motoneuronal population of the rat's common peroneal nerve following severe crush injury of the sciatic nerve or its component branches. The crush was performed unilaterally under anesthesia for 60 seconds with hemostat jaws covered with tubing to form a smooth, 2 mm long, injured zone. Recovery from injury was allowed for 14 to 188 days. It was measured behaviorally using the sciatic functional index (SFI) and electrophysiologically by comparing the conduction velocity and amplitudes of evoked muscle action potentials prior to injury, and again after injury just before the nerve was labeled with horseradish peroxidase (HRP), and/or its wheat germ agglutinin conjugate (WGA-HRP), 48-72 hours before sacrifice. The motoneurons were retrogradely labeled on both sides so that the uninjured side might serve as a control. On the injured side the nerves were labeled either distal or proximal to the crush site. The tibialis anterior muscles on both sides were removed and weighted. Spinal segments L2 to L6 were cut in serial, frozen cross-sections. HRP reaction products were formed using TMB as the chromogen. The normal peroneal nerve was found to contain 634 +/- 26 motoneurons (22 cases). The number of motoneurons labeled 5-15 mm distal to the injury site (22 cases) was 535 +/- 69 or 84.4% of normal. In 12 cases in which the nerve was labeled 5 mm proximal to the injury normal population numbers (648 +/- 30) were found. These counts demonstrated that the unlabeled 15.6% in the distal labeled cases had not vanished as a result of cell death. Instead, the unlabeled group was composed mainly of small motoneurons whose axons probably had not regenerated distal to the crushed zone. Mean soma size of injured neurons increased to maximum 3-6 weeks after injury and then gradually decreased in size over the following weeks to nearly normal values. This transient increase in size was due to two factors: 1) soma swelling in response to axonal injury, and 2) absence of many small motoneurons, presumably gamma-motoneurons, which were either incapable of, or prevented from, regenerating beyond the injury zone long after larger motoneurons had reinnervated their targets. SFI scores, muscle weights, and amplitude ratios of evoked potentials recovered to control values by 70-80 days post-injury. Conduction velocities remained 20-25% below normal at the end of 80 days.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Sensory neurons of the rat sciatic nerve.

Experiments have been undertaken in this laboratory over recent years to accurately determine the numbers and sizes of somatic neurons which contribute to the normal sciatic nerve, at mid-thigh levels, of the adult, albino rat. This article is concerned with the dorsal root ganglion (DRG) neuron population of the sciatic nerve whose cell bodies were identified through retrograde labeling of cut branches of the sciatic with horseradish peroxidase (HRP) and/or its wheat germ conjugate (WGA-HRP). It is essential to understand the neuronal composition of the normal rat sciatic nerve if the consequences of aging, nerve injury, and surgical repair to improve functional regeneration are to be properly evaluated. Neuron counts were determined from camera-lucida paper drawings of all labeled profiles in DRGs L3-L6 at 100 x magnification. The profiles, obtained by labeling individual branches of the sciatic nerve (sural, lateral sural, tibial, peroneal, medial, and lateral gastrocnemius/soleus nerves) were traced from 40-microns-thick, serial, frozen sections. The sizes of the perikarya, areas and diameters, were determined by tracing the perimeters of the drawn profiles on a digitizing tablet. The tablet's output was inputted directly into a specially designed computer spreadsheet which contained a mathematical table for correcting the split-cell error inherent to the sectioning process. Afferents from any given branch of the sciatic normally occupied two to three adjacent ganglia. Sciatic DRG neurons were normally located in lumbar ganglia L3-L6. Nearly 98-99% of all sciatic DRG perikarya resided in the L4 and L5 DRGs. The L6 DRG, traditionally regarded as an important contributor to the rat sciatic, contained merely 0.4% of its afferent neurons while the L3 ganglion, frequently overlooked as a contributor, contained 1.2% of the mid-thigh sciatic afferents. The mean size of rat DRG neurons was about 29 microns (550-600 microns2). The corrected counts revealed that the normal sciatic nerve (at mid-thigh levels), in rats between 2 and 12 months of age, contained a mean, total DRG neuron population of about 10,500 neurons. This is probably an underestimate by 3-5% of the true number due to occasional unreliable labeling of some of the small DRG neurons. It is estimated that the normal, mean number of sciatic DRG neurons of young to middle-aged rats lies somewhere between 10,500 and 11,000 +/- 2000. The data suggest that nearly 20% of all DRG neurons in the sciatic nerve supply muscle afferents. The vast majority of the remaining neurons are involved with innervation of the skin.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

Cell culture of the mucinous variant of human colorectal carcinoma.

Two cell lines, RW-2982 and RW-7213, have been established for the first time from the mucinous variant of human colorectal carcinoma, which is a distinctive and important subtype that has a worse prognosis than the more common nonmucogenic large bowel carcinoma. Methods of establishment and observations made during 7 and 3 years, respectively, of continuous culture are described. These cell lines required 4-9 months of adaptation to tissue culture conditions before noticeable growth occurred. Both cell lines have the following unique properties: (a) growth in vitro as delicate branching three-dimensional tumor particles within a wide gel of insoluble, often translucent mucus (proteoglycan); (b) production of large quantities of carcinoembryonic antigen; (c) ability to survive or adapt to growth in media free of serum, hormones, growth factors, and all protein; and (d) tumorigenicity in multiple sites in nude mice, including liver, with especially rapid growth in the peritoneal cavity as gelatinous material that is nonadherent and noninvasive and thus resembles pseudomyxoma peritonei. Unlike other reported colorectal cell lines, these mucus-coated particulate cell lines will not readily grow as monolayers and grow much more slowly with a doubling time of 2 weeks or more. A serially transplantable tumor from the RW-7213 surgical specimen has also been maintained in nude mice since August 8, 1984. This tumor retains properties of the original specimen. Observations made on the tumor biology of mucogenic colorectal carcinoma using these cell lines are discussed.

Adenocarcinoma, Mucinous↗
PubMed1985

The Nurse Training Act: a historical perspective.

In response to a national cry of nursing shortage, the federal government passed the Nurse Training Act of 1964. This article traces the history of this critical nursing legislation, examines its outcomes, and analyzes the effect of the Act on nursing in the future.

Education, Nursing↗
PubMed1985

Assessing C.V.P.

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Central Venous Pressure↗