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Biomedical subjects

D A Barnhorst

Publications and source records attributed to D A Barnhorst.

At least 19 recordsLinked to original sources
PubMed1999

The survival of herpes simplex virus in multidose office ophthalmic solutions.

PURPOSE: To determine the survival of herpes simplex virus type 1 (HSV-1) in several multidose ophthalmic solutions. METHODS: In three separate trials, 10 aliquots of 5 ml each of three common multidose topical ophthalmic solutions, sodium fluorescein, proparacaine, and nonpreserved artificial tears, were inoculated with 10(5), 10(4), and 10(3) pfu per ml of HSV-1. All samples were titered on A549 cells at various time points for surviving HSV-1. RESULTS: Herpes simplex virus type 1 was not recovered from the fluorescein and proparacaine solutions at 1 hour or any time thereafter, regardless of inoculation titer. Herpes simplex virus type 1 was recovered from the artificial tears up to 7 days. CONCLUSION: Unlike adenovirus, HSV-1 does not survive in preserved fluorescein and proparacaine multidose solutions; therefore, office transmission is highly unlikely.

Benzalkonium Compounds↗
PubMed1999

Valacyclovir inhibits recovery of ocular HSV-1 after experimental reactivation by excimer laser keratectomy.

PURPOSE: The goal of this was to determine whether the systemic administration of valacyclovir (Valtrex) would reduce ocular shedding of herpes simplex virus 1 (HSV-1) after excimer laser ablation in the New Zealand rabbit latency model. METHODS: The in vitro 50% inhibitory concentration (IC50) of HSV-1 W strain was determined by using a plaque-reduction assay to verify its sensitivity to acyclovir. Forty-seven NZW rabbits latently infected with HSV-1 W strain were divided into four groups: I, 50 mg/kg/day valacyclovir; II, 100 mg/kg/day valacyclovir; III, 150 mg/kg/day valacyclovir; and IV, saline control. One half of the total dose of valacyclovir was delivered via intraperitoneal injections twice daily for 7 days beginning with one dose before excimer laser keratectomy. HSV-1 ocular shedding was determined from eye cultures for 7 days after treatment. RESULTS: The IC50 for HSV-1 W was determined to be 2.9 microg/ml. The administration of both 100 mg/kg/day (group II) and 150 mg/kg/day (group III) of valacyclovir significantly reduced the number of eyes from which latent HSV-1 was recovered compared with the control group. There was no difference between the control group and group I (50 mg/kg/day valacyclovir). However, all three valacyclovir dosages significantly reduced the total number of HSV-1 shedding days compared with the control group, and 100% HSV-1 TG latency was demonstrated for all four groups. CONCLUSION: Systemic administration of valacyclovir significantly reduced HSV-1 ocular shedding in a dose-dependent manner after excimer laser keratectomy in the NZW rabbit latency model.

Acyclovir↗
PubMed1998

Efficient reactivation of latent herpes simplex virus type 1 infection by excimer laser keratectomy in the experimental rabbit ocular model.

PURPOSE: To investigate the role of excimer laser keratectomy as a trigger for the reactivation of latent HSV type 1 (HSV-1) in the New Zealand rabbit ocular model. There are conflicting reports in the current literature about reactivation of HSV-1 after excimer laser photoablation. METHODS: New Zealand rabbits were inoculated topically with HSV-1 McKrae or W strain in each eye, and culture-positive dendritic keratitis was documented on day 7. After the establishment of latency (21+ days), animals were divided into three groups: group I animals underwent excimer laser photoablation in each eye; group II animals received intrastromal injections of sterile water to act as positive controls (a standard method); and group III animals received no treatment and represented spontaneous shedders. All eyes were swabbed daily from days 1 through 10 and plated on A549 cells. Recovery of HSV-1 on days 1 through 10 postinduction was analyzed to compare the efficiency of the different methods of viral reactivation. RESULTS: Reactivation of latent HSV-1 after excimer treatment was observed in nine (45%) of 20 eyes and was equivalent to the rate of reactivation seen in the positive control animals (eight [44.4%] of 18 eyes) (P=.99). Both of these rates were significantly greater than those of the untreated animals (one [5.6%] of 18 eyes) (P=.018). CONCLUSION: Excimer laser keratectomy appears to be an efficient trigger for the reactivation of latent HSV-1 in the New Zealand rabbit ocular model.

Animals↗
PubMed1997

Pellucid marginal degeneration with superior corneal thinning.

PURPOSE: Pellucid marginal degeneration is a noninflammatory thinning disorder typically involving the inferior cornea. We describe a patient with superior corneal thinning similar to classic pellucid marginal degeneration. METHODS: An 80-year-old man was evaluated for high astigmatism. RESULTS: The right superior cornea had a prominent band of thinning with ectasia. Both inferior corneas had characteristic zones of thinning without inflammation. CONCLUSIONS: Superior pellucid marginal corneal degeneration should be considered in the differential diagnosis of superior corneal ectatic disorders.

Aged↗
PubMed1996

The efficacy of topical metronidazole in the treatment of ocular rosacea.

PURPOSE: The purpose of the study is to investigate the efficacy of metronidazole topical gel in the treatment of ocular rosacea. METHODS: Ten patients with ocular rosacea were treated prospectively with lid hygiene and topical metronidazole applied to the lid margin in one eye and lid hygiene alone in the fellow eye. The treatment period was 12 weeks. A masked observer graded the ocular findings at the initial visit and at the conclusion of the treatment period. Pretreatment scores were compared with post-treatment scores with respect to ocular surface, eyelid margin, and combined eyelid plus ocular surface. RESULTS: Eight of ten treated eyes improved, whereas only five of ten control eyes improved. There was a statistically significant improvement in the eyelid score in both the treated and control groups (P = 0.003, P = 0.025, respectively), but no significant improvement in the ocular surface score in either group. When the pretreatment and post-treatment eyelid and ocular surface scores were combined, there was a significant improvement in the treated eyes but not in the control eyes (P = 0.022, P = 0.10, respectively). No adverse effects of the metronidazole treatment were encountered in this study. CONCLUSION: Metronidazole topical gel may be a safe and effective means of treating rosacea blepharitis.

Administration, Topical↗
PubMed1995

Posterior scleritis with annular ciliochoroidal detachment.

PURPOSE: We studied an unusual case of posterior scleritis in a patient with sarcoidosis. METHOD: The medical record was reviewed for clinical manifestation, course, and tests performed, including laboratory evaluations, fluorescein angiography, and ultrasonography. RESULTS: The patient had posterior scleritis and unilateral angle-closure glaucoma caused by an annular ciliochoroidal detachment. Sarcoidosis was confirmed by biopsy of an enlarged parotid gland. CONCLUSION: The mechanism of angle-closure glaucoma may not be clinically or echographically apparent for a week or more in patients who develop annular ciliochoroidal detachment. We also found an unusual association of sarcoidosis and annular ciliochoroidal detachment secondary to posterior scleritis.

Adrenergic beta-Antagonists↗
PubMed1978

Regional myocardial wall thickening response to nitroglycerin. A predictor of myocardial response to aortocoronary bypass surgery.

The peak rate of systolic wall thickening (p +/- dTw/dt) in regions of the left ventricle (LV) was determined preoperatively by biplane roentgen videometry in 18 patients before and after sublingual administration of nitroglycerin (NTG) and 3-23 months (median 12) after aortocoronary bypass surgery. The regional LV response to NTG was a reliable predictor for postoperative improvement in regional wall dynamics after successful aortocoronary bypass grafting. The ejection fraction response to NTG or surgery will not predict the regional myocardial response to NTG or surgery, nor will the regional response predict the global response. Subendocardial myocardial infarction is another cause of unimproved regional myocardial function after NTG and aortocoronary bypass surgery.

Adult↗
PubMed1977

False aneurysm of the descending aorta: a complication of umbilical artery catheterization.

A patient had an aneurysm of the descending aorta secondary to aortitis arising from umbilical artery catheterization and in association with coarctation of the aorta. The aortitis probably was the direct result of bacterial contamination of the umbillicus and catheter with Staphylococcus aureus and the placement of the catheter tip just distal to a coarctation of the aorta. The patient required surgical resection of the coarctation and aneurysm of the descending aorta and placement of a tubular Dacron graft at 6 month of age. This is, to our knowledge, a hitherto unreported complication of umbilical artery catheterization.

Aneurysm, Infected↗
PubMed1977

Traumatic popliteal arteriovenous fistula. Diagnostic methods and surgical management.

The popliteal vessels rank second only to the external iliac system as the most frequent site of acquired arteriovenous communication. Direct trauma to the popliteal space is by far the most common cause, and surgical intervention is usually required to manage the defect. We present a recent illustrative case following meniscectomy. To our knowledge, the occurrence of an arteriovenous fistula complicating knee surgery has not been reported previously. This case outlines the potential value of B-mode ultrasound in diagnosis and the use of intraoperative angiography in assessing the adequacy of primary vascular reconstruction. Earlier experience of this vascular abnormality--six additional cases since 1941--is reviewed.

Adult↗
PubMed1977

Hemodynamic benefits of atrioventricular sequential pacing after cardiac surgery.

The hemodynamic effects of atrioventricular (A-V) sequential pacing were assessed and compared with those of ventricular and of atrial pacing in 10 patients with and without heart block after cardiac surgery. Ventricular pacing alone was either hemodynamically detrimental or of no benefit in six of the eight patients who initially had sinus or accelerated junctional rhythms. Atrial pacing alone produced significant improvement in cardiac output in all patients who were not pacemaker-dependent. However, five of the eight patients with intact A-V conduction had further increases in cardiac output through A-V sequential pacing at shorter than intrinsic A-V intervals. Optimal A-V intervals for maximal cardiac output could be identified in all patients and varied widely. Significant changes in cardiac output occurred with relatively small diviations in the A-V interval. In selected patients after cardiac surgery, temporary A-V sequential pacing is a workable and valuable adjunctive form of hemodynamic support and is preferable to ventricular or atrial pacing.

Adolescent↗
PubMed1977

A critical look at temporary ventricular pacing following cardiac surgery.

The effect of atrial, ventricular, and atrioventricular (A-V) sequential pacing on cardiac output (CO) was evaluated in patients within 24 hours after cardiac surgery. In patients with normal sinus rhythm, ventricular pacing reduced CO by as much as 42% (average, 14%), whereas atrial and A-V sequential pacing at the same rate increased CO by averages of 13% and 19%, respectively. In patients with junctional rhythm, increase of the heart rate by ventricular pacing produced an increase in CO, however, and an additional 25% increase in CO could be obtained by atrial or A-V sequential pacing at the same rate. Atrial or A-V sequential pacing was superior to ventricular pacing at the same rate and they are the preferred methods for temporary carciac pacing in the postoperative period. In suitable cases elective A-V sequential pacing is an effective method for increasing CO after cardiac surgery.

Adult↗
PubMed1977

Survival predictors in coronary artery disease. Medical and surgical comparisons.

Linear discriminant function analysis was used to test the independent prognostic value of nine variables in patients with coronary artery diseaase. For 68 medically treated patients who met the criteria for inclusion in the discriminant function analysis, the most reliable predictor of 2-year survival status was the left ventricular ejection fraction. The prognostic value of the ejection fraction was not improved by the addition of the number of vessels diseased. Comparisons of the survival of 130 medical and 284 surgical patients were made using subsets based on the ejection fraction. When the ejection fraction was greater than or equal to 50%, the probability of 4-year survival was high for both medical (91%) and surgical (96%) groups. When the ejection fraction was less than 25%, the probability of 2-year survival was low in both groups. However, for patients with ejection fraction 25 through 49%, the surgical patients had a better chance (P less than 0.05) for a 3-year survival (89%) than did medical patients (68%). This study emphasizes the prognostic significance of the left ventricular ejection fraction, which should be considered in any comparison of survival in medically and surgically treated patients.

Age Factors↗
PubMed1977

Early saphenous vein grafting after subendocardial infarction. Immediate surgical results and late prognosis.

In a prospective study of subendocardial myocardial infarction (SEI), 64 patients underwent coronary arteriography and left ventriculography early after their SEI. Of these 64 patients, 28 had saphenous vein grafting (SVG) performed within 3 months of SEI. The majority of this surgical group (24 of 28 patients) were operated on because of unstable angina following their SEI. Of these 28 patients, three suffered a perioperative myocardial infarction (10.7% incidence) and another patient died immediately postoperative (3.6% mortality). At a mean follow-up period of 16 months, 22 of these 28 patients (78%) were free of angina; in addition, there were no late deaths or recurrent myocardial infarctions in this surgical group. Therefore, SVG appears to improve the functional status of the majority of this group of patients with a complication rate at surgery comparable to that reported for unstable angina alone.

Adult↗