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Biomedical subjects

R Abel

Publications and source records attributed to R Abel.

At least 91 records · Page 5Linked to original sources
PubMed1983

[Two-dimensional stress echocardiography and plasma catecholamine measurements in the evaluation of the physiologically hypertrophied heart].

Two-dimensional stress echocardiography was performed in 8 untrained subjects, 8 long-distance runners, and 8 cyclists. The ergometric investigation was performed with subjects in supine position on a bicycle ergometer with increasing work loads of 50 Watts. At each working level, lactate, norepinephrine, and epinephrine were measured. The long-distance runners and the cyclists had an equal maximum oxygen uptake when tested with treadmill or bicycle ergometer. Absolute and relative heart volumes also showed the same amount of hypertrophy. In spite of this, lactate, catecholamines, and heart rate of the long-distance runners rose earlier during the supine ergometer test. End-diastolic volume and stroke volume in the cyclists increased significantly more (delta EDV = 15%, delta SV = 32%) than in the long-distance runners (delta EDV = 1%, delta SV = 13%) and untrained subjects (delta EDV = 5%, delta SV = 9%). It is assumed that this difference in heart function is caused by diminished sympathetic activity, which is dependent on the aerobic capacity of the working muscles.

Adolescent↗
PubMed1978

Effect of weight loss without salt restriction on the reduction of blood pressure in overweight hypertensive patients.

Overweight patients with uncomplicated essential hypertension were followed up biweekly for six months: 24 not receiving antihypertensive-drug therapy (Group I) and 83 on regular but inadequate (despite drug manipulation) antihypertensive-drug therapy (Group II). All patients in Group I and 57 randomly selected patients from group II (IIa) participated in a weight-reduction program. The remaining 26 from Group II (IIb) did not receive a dietary program. Salt intake was in the normal range in all three groups. All patients on the dietary program lost at least 3 kg (mean, 10.5 kg), and all but two showed a meaningful reduction in blood pressure; 75 per cent of Group I and 61 per cent of Group IIa returned to normal blood pressure. The weight and blood-pressure reductions were highly significant (P less than 0.001), were present in both sexes and all ages, and were directly associated. In Group IIb, no significant change in blood pressure or weight occurred (P greater than 0.30).

Adult↗
PubMed1976

Intraocular penetrating of amoxicillin.

The enucleated eyes of New Zealand albino rabbits were injected with 50, 100, 250, and 500 mg/kg of amoxicillin to determine the drug penetration into the aqueous humor, vitreous humor, serum, and other ocular tissues after oral administration. Detectable levels were achieved after each specific dose for at least five hours. In the aqueous humor, drug levels were present at 15 minutes, peaked at 1.5 and two hours, and were present at leave five hours after oral administration.

Amoxicillin↗
PubMed1976

Subconjunctival gentamicin prophylaxis against postoperative endophthalmitis in the rabbit.

An experimental aphakic rabbit model was employed in order to evaluate the correlation of the clinical course of postoperative endophthalmitis and the ability to recover microorganisms in the postoperative time period, the ocular antibiotic penetration of gentamicin, and the value of antibiotic prophylaxis. 2. Staphylococcus aureus is far more pathogenic organism than Staphylococcus epidermidis. A concentration of 5,000 organisms resulted in an 88% infection rate whereas 50,000 organisms and greater resulted in 100% infection rate after extracapsular cataract extraction. 3. Staphylococcus aureus could be isolated from the eyes demonstrating infection following cataract extraction for 2 days (3 days in one case) and then could no longer be recovered despite the persistance of intraocular inflammation. 4. The infection which appeared in animals receiving 5,000 organisms of Staphylococcus aureus after peripheral iridectomy was significantly milder than that which occurred following cataract extraction. In addition, the microorganisms could only be isolated on the first postoperative day. 5. When 20 mg of gentamicin sulfate was administered subconjunctivally following the post-cataract extraction or post-iridectomy administration of the 5,000 organisms of Staphylococcus aureus, none of the eyes developed clinical signs of endophthalmitis nor could bacteria be recovered. 6. Subconjunctivally administered gentamicin sulfate rapidly penetrated into the aphakic rabbit eye; 75-100 mug/ml appears in the aqueous humor at 1 hour and persists in bactericidal concentrations for at least 4 hours in both the treated and contralateral eyes. 7. Antimicrobial (subconjlnctival gentamicin sulfate 20 mg/prophylaxis at the time of surgery in the experimental animal significantly reduced the incidence of experimental postoperative bacterial endophthalmitis.

Animals↗
PubMed1976

Diagnostic and therapeutic vitrectomy for endophthalmitis.

The introduction of a compact portable vitreous suction cutter enables the aspiration and resection of infected ocular tissues for diagnostic and therapeutic purposes. Four cases of postoperative bacterial endophthalmitis are presented in which mechanical anterior vitrectomy was performed in addition to conventional antimicrobial therapy. Three of these eyes were saved and 2 retained the possibility of useful vision. A rationale for the aggressive managements of endophthalmitis is presented.

Aged↗
PubMed1976

Dissecting ocular tissue for intraocular drug studies.

This report describes a convenient reproducible ocular dissection technique which has important applications for ocular antimicrobial penetration studies. Different ocular tissues can be sectioned while frozen and then plated directly on culture medium containing the test organism; after the zones of bacterial inhibition are measured at 18 hours following incubation, the tissue specimens are weighed providing more reliable evidence regarding drug concentrations. In such a fashion, a drug can be administered topically, subconjunctivally, or systematically, and assayed from the cornea to the optic nerve at various time intervals. Analysis of antibiotic in the vitreous body, which has important application in the therapy of endophthalmitis, can be routinely performed in the experimental model.

Animals↗
PubMed1975

Bacterial endophthalmitis following suture removal after penetrating keratoplasty.

Of three cases of bacterial endophthalmitis occurring after removal of corneal sutures following penetrating keratoplasty, two were associated with wound dehiscence and one was not. Factors that may predispose to wound dehiscence and subsequent infection are: use of fine suture material, corticosteroids, and chronic topical antibiotics; early removal of corneal sutures; lack of adherence to strict asepsis prior to and after suture removal; and open suture tracts that may be kept open by incarceration of vitreous strands. Late corneal wound dehiscence may occur with subsequent development of endophthalmitis as long as three days after suture removal. The use of topical antibiotics before and after suture removal may decrease the potential for infection. In addition, early recognition of intraocular infection by the patient and the surgeon for immediate institution of antimicrobial and anti-inflammatory therapy may preserve useful vision.

Administration, Topical↗