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Biomedical subjects

R S Wagner

Publications and source records attributed to R S Wagner.

At least 19 recordsLinked to original sources
PubMed1997

Characterization of signal transduction events stimulated by 8-epi-prostaglandin(PG)F2 alpha in rat aortic rings.

One of the most abundant F2 isoprostanes formed under pathological conditions is 8-epi-prostaglandin F2 alpha (8-epi-PGF2 alpha), a potent vasoconstrictor. The purpose of this study was to determine the signal transduction events initiated by 8-epi-PGF2 alpha-induced vasoconstriction. Isolated arterial rings from male Sprague-Dawley rats were suspended in tissue baths containing Krebs-Henseleit salt solution, stretched to optimal resting tension and stimulated. 8-epi-PGF2 alpha induced concentration-dependent contractions in pulmonary arteries (EC50: 7.7 +/- 2.1 microM; n = 3) and aortas (EC50: 0.9 +/- 0.1 microM; n = 4) which were blocked by the TXA2 receptor antagonists SQ29548, L657925 and L657926. The contractile response to 8-epi-PGF2 alpha was significantly (*p < 0.05; n = 4) diminished by: 1) indomethacin and ibuprofen; 2) Ca++ free media; 3) verapamil, a voltage gated Ca++ channel blocker; 4) flunarizine, a T-type Ca++ channel blocker; and 5) calphostin C, a protein kinase C inhibitor. These data suggest that the contractile response to 8-epi-PGF2 alpha is: 1) mediated via activation of TXA2 receptors; 2) partially dependent on the synthesis and release of other cyclooxygenase derived products; 3) dependent on an influx of extracellular Ca++ possibly via Ca++ channels; and 4) may be PKC dependent.

Animals↗
PubMed1997

Phosphodiesterase inhibition improves agonist-induced relaxation of hypertensive pulmonary arteries.

Pulmonary artery (PA) relaxation in response to vasodilators is significantly attenuated in models of hypoxia-induced pulmonary hypertension (HPH). The activity of phosphodiesterases (PDE) which hydrolyze vasodilatory second messengers may be increased by HPH, which thereby contributes to attenuated vasodilatory responses. The purpose of this study was to determine the effect of PDE inhibition on agonist-induced relaxation of PA from normal rats and rats with HPH (F(IO2), 0.1 for 14 days). Isolated PA rings were suspended in baths containing Krebs-Henseliet salt solution and contracted with U46619 in the presence or absence of a PDE3 (milrinone) or PDE4 (rolipram) inhibitor. Isoproterenol and forskolin induced concentration-dependent relaxation of PA rings from normal rats and rats with HPH, but the degree of relaxation was significantly less (*P < .05; n = 4) in PA from rats with HPH. Treatment with either PDE inhibitor significantly improved (*P < .05; n = 4) the magnitude of agonist-induced relaxation in PA rings from normal rats and rats with HPH. Additionally, PDE3A transcripts (8 and 10 kb) were increased (3.8 +/- 1.6-fold and 3.9 +/- 1.2-fold; n = 3, respectively) in PAs from rats with HPH compared with normal controls. These data show that inhibition of PDE3 and PDE4 activity can significantly improve PA relaxation in HPH and that expression of PDE3A mRNA is increased during HPH. These findings suggest that PDEs play an important role in the development and maintenance of HPH.

Animals↗
PubMed1996

Combined paresis and restriction of the extraocular muscles after orbital fracture: a study of 16 patients.

Sixteen patients with combined paresis and restriction of extraocular muscle(s) orbital fracture repair were studied before and after in order to determine the clinical features and management of such patients. All 16 patients showed limited ductions of the involved eye in the field of action of the entrapped, paretic muscle and of the antagonist muscle after orbital fracture. Single extraocular muscles (13 patients) and two extraocular muscles (three patients) were demonstrated adjacent to the fracture site on orbital computed tomography (CT). In three patients prior to orbital surgery, a deviation in primary position was present. After fracture repair with release of the entrapped muscle in all patients, evidence of paresis of the muscle was demonstrated by underaction in its field of action and overaction in the field of its antagonist. There was a resultant manifest tropia or phoria in the primary position. In seven patients, the paresis gradually improved with no tropia and little diplopia in the functional fields of gaze. Three patients had minimal deviations and required no further treatment. Six patients with significant deviations required prisms (three patients) or strabismus surgery (three patients). The latter three patients had two muscles involved. Results of this study demonstrate that the ophthalmologist must appropriately diagnose patients with paresis and restriction of an extraocular muscle and counsel them that "new" diplopia may occur after orbital fracture repair and that this diplopia may require additional therapy.

Adolescent↗
PubMed1996

Activation of thromboxane A2 receptors alters lipopolysaccharide-induced adherence of THP-1 cells.

U46619, a thromboxane A2 (TXA2) mimetic, inhibits human monocyte chemotactic responses, suggesting that TXA2, an arachidonic acid metabolite, may alter monocyte adhesion. We tested the hypothesis that TXA2 alters Lipopolysaccharide (LPS)-induced adhesion of THP-1 cells, a human monocytic leukemia cell line. Salmonella enteritidis endotoxin (1 microgram/mL) induced a significant (p < .05; n = 6) increase in the adherence of THP-1 cells (basal, 5.7 +/- 1.8 micrograms/well; LPS, 78.8 +/- 4.9 micrograms/well). Treatment of THP-1 cells with indomethacin or TXA2 receptor antagonists before LPS stimulation significantly (p < .05) enhanced adhesion, suggesting that endogenously produced TXA2 or prostaglandins alter LPS-induced THP-1 cell adhesion. TXA2 mimetics significantly decreased (p < .05; n = 5 and n = 3, respectively) LPS-induced THP-1 cell adhesion. This effect was blocked by three structurally dissimilar TXA2 receptor antagonists. These results support the hypothesis that TXA2 alters LPS-induced adhesion of THP-1 cells.

Cell Adhesion↗
PubMed1993

Glaucoma in children.

Glaucoma in children is a relatively rare but frequently debilitating disorder. Pediatricians must be aware of the association of glaucoma with certain systemic diseases and congenital ocular abnormalities. Recognition of the signs of infantile glaucoma allows the physician to refer patients for definitive care. Timely therapy is critical to the successful management of children affected with glaucoma.

Child↗
PubMed1992

The sit-up test: an alternate clinical test for evaluating pediatric torticollis.

The sit-up test, a new evaluation method for differentiating between ocular and orthopaedic torticollis, was evaluated against the monocular occlusion test, using results of three-step testing for standardization. The study group consisted of 31 patients with torticollis between the ages of 4 and 12.5 years. Subjects were selected based only on their ability to cooperate with three-step testing. Three-step testing identified 27 of the 31 patients as having ocular torticollis, with the remaining 4 having an orthopaedic etiology. Sit-up testing correctly identified all 27 ocular torticollis patients, with no false positives or false negatives. Monocular occlusion testing detected at best 22 (81.4%) of the ocular torticollis patients, with no false positives.

Child↗
PubMed1991

Simplified limbal incision for extraocular rectus muscle surgery.

We describe a limbal incision for extraocular muscle surgery which involves only one incision to the conjunctival-Tenon's layer instead of the three separate incisions required in the standard limbal approach. Based on the 316 extraocular muscle operations in which we have used this one-snip procedure, we conclude that it is simpler and faster than the standard limbal incision, and that it provides good surgical exposure and probably less tissue damage.

Esotropia↗
PubMed1990

Nystagmus in Down's syndrome.

The incidence and characteristics of nystagmus in Down's syndrome are unclear. In 188 consecutive patients, 56 had nystagmus. Most had no clinically recognizable ocular pathology to account for the nystagmus. Twenty-nine had fine rapid horizontal nystagmus, 14 had a dissociated nystagmus which appeared pendular, whereas 9 had a form of latent or manifest latent nystagmus. Of the total patients with nystagmus, 41 had esotropia. Our findings suggest that fine rapid horizontal nystagmus, sometimes dissociated, occurs frequently in patients with Down's syndrome.

Adolescent↗
PubMed1990

A modified extracapsular cataract extraction for pediatric cataracts.

We present a modified procedure of extracapsular cataract extraction (ECCE) with a small central posterior capsulectomy for pediatric cataracts that is designed to eliminate posterior capsule opacification and to keep open the option of later secondary implantation of a posterior chamber intraocular lens. Of 76 study eyes in which the procedure was performed only three developed posterior capsule opacification. All seven control eyes that had standard ECCE with the posterior capsule left intact developed secondary membranes shortly after surgery.

Adolescent↗
PubMed1990

Preferred postoperative alignment after congenital esotropia surgery.

A total of 117 patients with congenital esotropia who underwent muscle surgery were included in our study and were followed for a minimum of three years. Only those patients who were orthotropic or were within +/- 10 prism diopters (PD) of orthotropia six months postoperatively were included. Of the 117 patients, 101 patients (86%) remained orthotropic or within +/- 10 PD of orthotropia three years postoperatively, but 13 patients (11%) developed consecutive exotropia (greater than 10 PD). Five years after surgery, 17 of 68 patients (25%) had consecutive exotropia (greater than 10 PD). Our study demonstrates that despite satisfactory postoperative alignment, there is a steady progression towards exotropic drift over long-term follow-up. Our study also suggests that a preferred alignment shortly after congenital esotropia surgery is within 10 PD of esotropia since all of the patients who had consecutive exotropia (greater than 10 PD) were either orthotropic or exotropic (less than or equal to 10 PD) six months after surgery.

Esotropia↗
PubMed1989

A survey of severe eye injuries in children.

We reviewed the medical records of 258 children from newborn to 20 years of age who had ocular injuries severe enough to warrant admission to United Hospitals Medical Center, Newark, NJ, over a 3 1/2-year period. In this time there were 1737 pediatric admissions for eye treatment and of these, 258 (14.85%) were directly related to trauma. Only strabismus, with 676 (38.9%) admissions, accounted for more pediatric hospitalizations for eye injuries. Balls, fists, and sticks were the most common causes of injury, and the most common diagnosis was hyphema. The majority of injuries occurred in children between 11 and 15 years of age (31%). Ocular injuries in children above 10 years of age were most commonly sports-related, whereas injuries in the home accounted for the majority of trauma in children younger than 10 years of age.

Adolescent↗
PubMed1989

Down syndrome. Clinical review of ocular features.

A total of 187 medical records of Down syndrome individuals over a 10-year period were reviewed retrospectively for strabismus, myopia, hyperopia, astigmatism, nystagmus, cataract, glaucoma, and other significant eye findings. This study showed that a higher proportion of these individuals than reported in previous studies had strabismus (57%). Refractive errors of myopia (22.5%), hyperopia (20.9%) and astigmatism (22%) were common. The primary care physician needs to be aware of the specific eye problems of Down syndrome individuals so that he or she may initiate or refer the patient for appropriate ophthalmologic care, because most of the eye findings in Down syndrome are treatable. Significant visual loss, a usually avoidable event in Down syndrome, should occur rarely.

Adolescent↗