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Biomedical subjects

B Becker

Publications and source records attributed to B Becker.

At least 73 records · Page 4Linked to original sources
PubMed1982

Timolol and epinephrine: long-term evaluation of concurrent administration.

Thirty-two ocular hypertensive subjects were treated for 90 days with either 0.5% timolol maleate or 2% epinephrine hydrochloride twice daily to one eye and both drugs to the fellow eye. The ocular hypotensive effects of timolol and epinephrine were partially additive throughout the course of this study. On the 91st day, eyes treated with epinephrine had a 25.8% mean reduction of intraocular pressure from baseline, whereas their fellow eyes treated with epinephrine and timolol had a 33.9% reduction. Eyes treated with timolol had a 27.2% mean reduction of IOP, whereas fellow eyes treated with timolol and epinephrine had a 29% reduction. These results suggest that the majority of patients being treated with either drug are unlikely to have a substantial long-term reduction in IOP when the other drug is added to their therapeutic regimen.

Administration, Topical↗
PubMed1982

Timolol and acetazolamide. A study of concurrent administration.

A five-week clinical trial of the concurrent administration of topical timolol maleate and oral acetazolamide was conducted to determine the additivity of the ocular hypotensive effects of the two drugs. One drop of 0.5% timolol maleate, every 12 hours, produced a mean reduction in outflow pressure from baseline of 36.0%. When added to an eye pretreated with oral acetazolamide, timolol caused an additional mean decrease in outflow pressure of 27.6%. Acetazolamide, 500 mg orally every 12 hours, produced a mean reduction in outflow pressure from baseline of 48.6%. When added to an eye receiving topical timolol, oral acetazolamide caused an additional mean decrease in outflow pressure of 43.2%. Concurrent administration of oral acetazolamide and topical timolol reduced outflow pressure only slightly less than the predicted reduction assuming full additivity of the drugs. This study supported the clinical usefulness of concurrent administration of acetazolamide and timolol to lower intraocular pressure.

Acetazolamide↗
PubMed1982

Q-T prolongation and polymorphous ("torsade de pointes") ventricular arrhythmias associated with organophosphorus insecticide poisoning.

It is not generally appreciated in the Western world that organophosphorus poisoning may be associated with a serious and often fatal cardiac complication: Q-T interval prolongation with malignant ventricular arrhythmias of the "torsade de pointes" type. This insidious complication may lead to delayed, sudden death after the patients appears to be well on the way to recovery from the other, more dramatic respiratory and neurologic symptoms. In this study 15 patients with organophosphorus poisoning are described. Q-T prolongation was observed in 14 and malignant tachyarrhythmias in 6. In view of the dismal prognosis of these patients, ventricular pacing, previously used with success in other conditions associated with this syndrome, was tried in four patients and successfully shortened the Q-T interval and eliminated the arrhythmias. Isoproterenol did the same in a fifth patient. Awareness of this lethal, but preventable complication of organophosphorus poisoning is called for. Careful electrocardiographic monitoring is necessary until the Q-T interval returns to normal. Electrical pacing appears to be the treatment of choice for the tachyarrhythmias.

Adolescent↗
PubMed1982

Central corneal endothelial cell density and central corneal thickness in ocular hypertension and primary open-angle glaucoma.

In order to assess the effect of increased intraocular pressure on the corneal endothelium, we classified 254 patients into four groups: Group 1, those with normal intraocular pressures; Group 2, those with untreated ocular hypertension; Group 3, those with treated ocular hypertension; and Group 4, those with primary open-angle glaucoma. One eye of each patient underwent specular microscopy and pachymetry. The eyes in the four groups did not differ significantly as to central corneal endothelial cell density or central corneal thickness. These measurements were not related to sex, race, or intraocular pressure (P greater than .12 in all cases). Increasing age was associated with a decrease in central corneal endothelial cell density (P = .0001), but was not associated with a change in central corneal thickness (P = .22). There was no significant relationship between the use of topical ocular hypotensive medications and central corneal endothelial cell density (P = .38) or central corneal thickness (P = .07) in patients with ocular hypertension or primary open-angle glaucoma. Neither uncomplicated peripheral iridectomy nor trabeculectomy produced significant changes when preoperative measurements were compared to measurements made 12 weeks postoperatively (P greater than .30 in all cases). Two eyes with flat anterior chambers following trabeculectomy had substantial decreases in central corneal endothelial cell density.

Adult↗
PubMed1982

The onset and evolution of glaucomatous visual field defects.

Long-term follow-up was recorded on the visual fields of 251 patients with chronic open-angle glaucoma and 826 patients with ocular hypertension. Observation periods exceeded ten years for 73 patients with manifest glaucoma. Initial glaucomatous defects appeared in 98 eyes of 72 patients while under continuous observation. Initial defects were characteristically shallow and were located most commonly in the superior Bjerrum region adjacent to the blind spot. Three-dimensional (contiguous area) static perimetry provided superior resolution in detecting and characterizing the full extent of such shallow defects. The chronologic course of initial defects defects was marked in 22 of the 98 eyes by a phenomenon of a transiently appearing defect. Disappearance and reappearance of transient defects did not occur synchronously with short-term fluctuations in intraocular pressure. Ten-year follow-up of 63 eyes with manifest glaucomatous defects showed a high incidence (73%) of progression to dense involvement of the originally affected altitudinal hemifield. All eyes were treated continuously, but visual field loss occurred in spite of only marginally elevated levels of intraocular pressure.

Female↗
PubMed1982

Ocular and systemic effects of acetazolamide in nephrectomized rabbits.

The effects of acetazolamide on intraocular pressure (IOP) were studied on rabbits previously nephrectomized to eliminate the renal effects of the drug. Administration of acetazolamide (5 mg/kg i.v.) reduced IOP from a baseline of 15.2 to 12.2 mm Hg 2 hr later. This dose was found not to alter arterial blood pH, pCO2, bicarbonate, or base excess. However, 4 hr after drug administration anterior chamber aqueous humor showed significant reductions in bicarbonate, pH, and base excess, whereas aqueous humor ascorbate was significantly elevated. Administration of acetazolamide 15 to 50 mg/kg i.v.) to nephrectomized rabbits caused significant acidosis and pCO2 retention, presumably related to red blood cell carbonic anhydrase inhibition. IOP reduction at these higher doses was greater than that which followed the 5 mg/kg administration.

Acetazolamide↗
PubMed1982

[The differential diagnosis of the unilateral by hyperlucent lung. Two case reports (author's transl)].

The "unilateral hyperlucent lung" is a roentgenologic diagnosis based on an increased radiolucency of one lung. Aetiology and pathogenesis of this clinical syndrome are discussed together with two own case reports about a 9-year-old girl and a 3-month old boy. Anamnesis, bronchography, scintigraphy and angiocardiography in the girl revealed a Swyer-James syndrome, where typically only one lung is damaged by obliterating bronchiolitis. In the patient the pulmonary changes developed subsequently to a measles-pneumonia, possibly enhanced by an additional pollinosis. The 3-month old infant had a left-sided pulmonary artery hypoplasia and obstructive bronchitis in both lungs. Up to its 7th month of life the child developed sufficiently under conservative therapy, but then a life threatening pneumonia with obstructive bronchitis and respiratory failure occurred, 3 weeks of artificial respiration were without success. The subsequent pneumectomy revealed a hypoplasia of the left lung and a big tracheal cyst as cause of the severe obstruction.

Age Factors↗
PubMed1981

One-hour intraocular pressure response to timolol. Lack of correlation with long-term response.

The initial topical administration of 1 drop of 0.25% timolol maleate in 25 nontreated ocular hypertensive patients resulted in a significant reduction of mean intraocular pressure one hour later, from a baseline of 28.1 +/- 5.3 (mean +/- SD) mm Hg to 18.5 +/- 4.5 mm Hg. Two patients (8%) failed to show at least a 10% decreases in IOP one hour after the initial administration. After three to four weeks of twice a day unilateral therapy with 0.25% timolol, mean IOP increased to 21.1 +/- 4.2 mm Hg. At this time seven patients (28%) failed to obtain a 10% decrease in IOP from topical timolol administration. Changing to 0.5% timolol for three to four weeks did not cause an additional significant lowering of IOP (20.4 +/- 3.5 mm Hg). At this time five patients (20%) had less than a 10% reduction in IOP. The one-hour response failed to predict future IOP nonresponsiveness.

Administration, Topical↗
PubMed1981

On the nature of the proglottids of cestodes: a light and electron microscopic study on Taenia, Hymenolepis, and Echinococcus.

The organisation of five species of cyclophyllidean cestodes (Hymenolepis nana, H. diminuta, H. microstoma, Taenia (Hydatigera) taeniaeformis, Echinococcus multilocularis) has been studied using light and electron microscopy (SEM, TEM). It was found that there is no indication of any internal structure separating the proglottids, which are recognisable superficially. Thus in cestodes there is no metameric segmentation as in annelids. The implications of these findings on the terminology of tapeworm morphology are critically discussed.

Animals↗
PubMed1981

Ultrastructural investigations on the effect of praziquantel on the tegument of five species of cestodes.

Adult Hymenolepis diminuta, H. microstoma, H. nana, Echinococcus multilocularis, and Taenia (Hydatigera) taeniaeformis have been exposed in vitro in media containing 0.1 to 100 micrograms praziquantel/ml. Already after 5 min characteristic tegumental lesions, that were restricted to the growth zone of the neck region, were recognized using both scanning and transmission electron microscopy. Within the tegument numerous vacuoles were formed that released their contents to the exterior and finally caused destruction of the tegument. Proglottides of the central or posterior strobilar portions were never damaged. Larvae of T. taeniaeformis (cysticerci) and E. multilocularis (alveolar cysts) were studied employing the same methods both after in vitro exposure to and after in vivo treatment of their hosts with praziquantel. Strobilocerci of T. taeniaeformis developed identical tegumental lesions after contact with praziquantel whether incubated in vitro or treated in vitro. The wall of the bladder containing the larva remained unaffected. Evaginated protoscolices of E. multilocularis were damaged by in vitro contact with praziquantel while invaginated protoscolices remained intact. After in vivo exposure there were some fully developed evaginated and damaged protoscolices whereas all invaginated protoscolices and the cyst wall with its germinative layer were unaffected.

Animals↗