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Biomedical subjects

F Jara

Publications and source records attributed to F Jara.

At least 19 recordsLinked to original sources
PubMed1995

Quantitative cleaning efficacy evaluation methods with protein and lipid lens soiling models.

We developed a nondestructive, quantitative method for evaluating the cleaning efficacy of rigid gas permeable contact lens care systems. Simulated tears prepared with lysozyme, albumin, and calcium ions were applied to rigid gas permeable lenses as a protein soiling model, and a mixture of grease and unsaturated fat was applied as a lipid soiling model. The ComfortCare system (Pilkington Barnes Hind) and the Boston Cleaner and Boston Conditioning Solution (Polymer Technology) were evaluated for their efficacy in removing protein deposits; water was used as a control. The ComfortCare system and the Boston Advance Cleaner and Boston Advance Conditioning Solution were evaluated for their effectiveness in removing lipid deposits; saline was used as a control. Protein deposit level was detected by a densitometer at the absorbance of 280 nm. The lipid deposit level was evaluated by the absorbance of the fluorescence at 430 nm using the same densitometer with a fluorescence accessory. The two test systems demonstrated a significantly higher cleaning efficacy than the control for both soiling models. The methods provide quantitative measurements and therefore can be analyzed statistically for screening or comparison purposes.

Contact Lens Solutions↗
PubMed1994

[The mechanism producing nausea during ventriculography performed with ioxaglate: the implications of a randomized study].

INTRODUCTION: The mechanism of ioxaglate-induced nausea has not been fully elucidated. Recent studies have demonstrated that serotonin is one of the principal neurotransmitters of emesis in humans. On the other hand, the greater capacity of ioxaglate to stimulate vomiting has been ascribed to its great ability to inhibit cholinesterase. METHODS: To determine if oral metoclopramide (a serotonin receptor-blocker) is effective in the prophylaxis of ioxaglate-induced nausea during left ventriculography, 637 of 711 consecutive eligible patients were included in a prospective study. Patients were randomized to receive, 60-90 minutes before the procedure, either diazepam 10 mg p.o. (control group [n = 315]) or diazepam 10 mg p.o. plus metoclopramide 10 mg p.o. (metoclopramide group [n = 322]). RESULTS: The two randomized groups were similar in relation to baseline clinical and hemodynamic characteristics. Nausea was documented in 103 patients (16.1%) with similar incidence in the two groups (control group: 16.8%, metoclopramide group: 15.5%; p = NS). Nausea duration was also similar (56 +/- 63 s vs 52 +/- 63 s; p = NS). When patients with and without nausea were compared, the following variables showed a significant difference between the two groups: male gender (86% vs 76%; p < 0.05), age (53 +/- 10 yrs vs 56 +/- 9 yrs; p < 0.05) and body surface area (1.84 +/- 0.2 m2 vs 1.78 +/- 0.1 m2; p < 0.01). Stepwise multiple regression analysis identified low age (p = 0.02) and male gender (p = 0.06) as independent predictors of nausea. The incidence of nausea was 24% in males < or = 45 yrs vs 9% in females > 45 yrs (p < 0.05). CONCLUSIONS: Prophylaxis with oral metoclopramide did not reduce the incidence of ioxaglate-induced nausea during left ventriculography. This data do not support a role of serotonin in the production of nausea by ioxaglate. Low age an male gender are independent predictors of nausea apparition during left ventriculography. A cholinergic mechanism is probably involved in the capacity of ioxaglate to stimulate vomiting.

Administration, Oral↗
PubMed1994

[Penetrating aortic ulcer: clinical and angiographic characteristics].

BACKGROUND: "Penetrating aortic ulcer", an atherosclerotic lesion with ulceration that penetrates the internal elastic lamina and allows haematoma formation within the aortic wall, is rarely considered in the differential diagnosis of patients with sudden onset of severe chest or back pain. It has been suggested that it is a pathologic process that involves elderly hypertensive patients with severe atherosclerosis and rarely has been observed in the ascending aorta. METHODS: To determine the characteristics of this process, 11 clinical, 2 hemodynamic, 3 angiographic and 4 surgical variables were compared between 10 consecutive patients with penetrating aortic ulcers and 20 matched patients with classic acute aortic dissection. RESULTS: Clinical and hemodynamic variables were similar in both compared groups. In the group of patients with penetrating ulcer mean age was 58 +/- 6 years, previous hypertension was observed in 6 patients and the penetrating ulcer was located in the ascending aorta in 6 cases. In comparison to patients with aortic dissection, more angiographic projections were necessary to obtain the diagnosis in the group of patients with penetrating ulcer (2.4 +/- 0.8 vs 1.7 +/- 0.6; p < 0.05). In addition, the presence of angiographic aortic valve regurgitation was only observed in the group of patients with acute dissection (60% vs 0%; p < 0.001). Severe atherosclerosis was not present angiographically in any patient with penetrating ulcer. CONCLUSIONS: Penetrating aortic ulcer can also affect middle age patients without severe atherosclerosis and is frequently observed in the ascending aorta. Its form of presentation and clinical characteristics are similar to classic aortic dissection. The lack of angiographic confirmatory evidence of dissection with suggestive clinical history, should raise the possibility of penetrating aortic ulcer.

Aortic Diseases↗
PubMed1991

Risk of thrombosis during coronary angioplasty with low osmolality contrast media.

Studies in vitro have suggested that nonionic low osmolar contrast agents produce an increase in thrombogenicity. To determine the incidence of thrombi related to the use of nonionic low osmolar contrast media during coronary angioplasty, a double-blind randomized study was performed in 100 patients. Medication before angioplasty included oral aspirin (250 mg/day) in all cases. At the beginning of the procedure, aspirin (250 mg) and heparin (10,000 U) were intravenously administered. During the procedure patients were randomly assigned to receive either an ionic low osmolar contrast agent ioxaglate (n = 50), or a nonionic low osmolar contrast media iohexol (n = 50). The presence of thrombus was evaluated on the angiogram and on the guidewire immediately after its retrieval from the patients. Clinical, angiographic and procedural variables were similar in the 2 randomized groups. Angiographic evidence of thrombus was observed in 1 patient (2%) assigned to ioxaglate and in 11 patients (22%) assigned to iohexol (p less than 0.005). One patient (2%) from the ioxaglate group and 6 patients (12%) from the iohexol group showed thrombotic residues on the guidewire (p = not significant). Three patients had acute myocardial infarction, 1 patient (2%) receiving ioxaglate and 2 patients (4%) iohexol (p = not significant). There were no deaths. Thus, compared with an ionic low osmolar contrast media ioxaglate, the nonionic low osmolar contrast agent iohexol increases the incidence of thrombus during coronary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1990

False coronary dissection with the new Monorail angioplasty balloon catheter.

During percutaneous transluminal coronary angioplasty, the appearance of persistent staining in the vessel by contrast media suggests coronary dissection. We report seven patients in whom a false image of severe coronary dissection was observed during angioplasty performed with the new Monorail balloon catheter. This image emerges at the moment of balloon inflation, is distally located to the balloon, and disappears with balloon catheter deflation. No complications were associated with the appearance of this image.

Angiography↗
PubMed1990

[Pulmonary valvuloplasty in adolescents and adults: 2 year follow-up by continuous Doppler].

The purpose of this study is the long term follow-up of the first pulmonary valvuloplasties performed by our group. From september 1984 to march 1988, 10 patients (4 men and 6 women) aged 8 to 58 (mean: 21) with severe or moderate pulmonary valve stenosis underwent pulmonary valvotomy. In all cases the balloon diameter was equal to or 1 mm smaller than the valvular annulus. The results were satisfactory with a significant mean gradient reduction of 51.7%. A follow-up gradient estimation by Doppler echocardiogram was obtained 10 to 37 months after valvuloplasty (mean: 23 months). The mean follow-up gradient by Doppler (31.3 +/- 9.9 mmHg) was not significantly different from the mean hemodynamic post-dilatation gradient (35.6 +/- 14.7 mmHg). A linear correlation was found between the post-dilatation hemodynamic mean gradient and the mean gradient by Doppler follow-up (r = 0.66, p less than 0.05, SEE = 4.1 mmHg). No restenosis were observed. These results suggest that the benefits of valvuloplasty are long lasting. Continuous Doppler is an excellent technique for the follow-up of these patients.

Adolescent↗
PubMed1990

[Comparative study of iohexol and iopamidol as cardioangiographic contrast media].

We have done a double-blind randomized study to compare the cardiac effects of 2 nonionic low osmolality contrast agents, iohexol (n = 25) and iopamidol (n = 25), for left ventriculography and coronary arteriography. No statistical differences were detected between both groups in quality of image, clinical (absence of nausea; intense warmth [8% vs 8%, p = NS]) and electrocardiography (repolarization changes [24% vs 12%, p = NS], absence of severe bradycardia and ventricular arrhythmia) effects. Ventriculography induced no change in systolic left ventricular pressure (iohexol: 128.6 +/- 18 vs 127 +/- 19 mmHg, p = NS; iopamidol: 133 +/- 24 vs 131.8 +/- 23 mmHg, p = NS), and a little but significant rise in left ventricular end-diastolic pressure (iohexol: pre = 11.6 +/- 7 vs post = 13.9 +/- 7 mmHg, p less than 0.01; iopamidol: 11.7 +/- 4 vs post = 15.5 +/- 5 mmHg, p less than 0.001). Our results suggest that iohexol and iopamidol are comparable and qualified for angiocardiography.

Angiocardiography↗
PubMed1989

Vancomycin therapy for gram-positive peritonitis in patients on CAPD.

We describe the use of vancomycin in the therapy of gram-positive peritonitis in patients on CAPD. Two ways of administration were in comparison: a) the intraperitoneal (IP) route, with the intraperitoneal administration of 30 mg/l vancomycin for 10 days and b) the intravenous (IV) route with 2 infusions of 1 gram of vancomycin, the first one on the day of the diagnosis of gram-positive peritonitis and the second 7 days later. Each one of these therapeutic schedules was applied at random for 20 episodes of peritonitis out of 40 episodes with gram-positive organisms (28 Staph. albus, 10 Staph aureus and 2 Streptococcus). Remission of clinical symptoms occurred in 49-72 hours in both groups, while macroscopic clearing of dialysate effluent and sterilization of cultures were observed in 4-7 days. Recurrence of peritonitis was seen in 4 patients of the IV group 2 weeks after the administration of the second dose of vancomycin. We conclude that the use of vancomycin with either of the two ways of administration is of great value in the treatment of gram-positive peritonitis. The IV infusion was less successful but it seems to be useful for the out-patient treatment of gram-positive peritonitis.

Drug Administration Schedule↗
PubMed1989

[Comparative studies of diatrizoate, ioxaglate and iohexol as angiocardiographic contrast media].

We did 2 consecutive randomized studies to compare the effects of diatrizoate, ioxaglate, and iohexol. Sixty patients were studied: 15 with diatrizoate (group I) versus 15 with ioxaglate (IIA), and 15 with ioxaglate (IIB) versus 15 with iohexol (III). Group I had hypotension and severe increase in end-diastolic pressure. Severe bradycardia was seen in 27% of the cases. Group IIA and IIB had identical changes, with a moderate increase in systolic and end-diastolic pressure. Group III only presented a mild increase in end-diastolic pressure. None of the low-osmolar contrast media produced severe bradycardia, but ioxaglate induced frequent (20%) nausea. Our results suggest the best contrast media for angiocardiography is, in decreasing order: iohexol, ioxaglate, and diatrizoate.

Angiocardiography↗