Search PubMed⌕ Search

Biomedical subjects

J Baum

Publications and source records attributed to J Baum.

At least 217 records · Page 12Linked to original sources
PubMed1981

Penetration of ocular tissues and fluids by moxalactam in rabbits with staphylococcal endophthalmitis.

Moxalactam was administered subconjunctivally in 100-mg doses to rabbits with infected eyes (Staphylococcus aureus endophthalmitis). High concentrations of drug were detected in the sclera, cornea, and choroid; much lower levels were found in the retina, whereas peak concentrations in the vitreous were about 6 microgram/ml. Repeated intramuscular injections of 50 mg/kg every 4 h produced peak serum levels of about 100 microgram/ml. A gradient between the choroid and the retina was again evident, and peak vitreous levels were about 6 microgram/ml after six injections. These data are consistent with the concept of a blood-retina barrier analogous to the blood-brain barrier. Moxalactam appears to penetrate the eye somewhat better than do other beta-lactams; however, the peak levels produced in the vitreous humor in this animal model were below the level required to inhibit most strains of Pseudomonas aeruginosa.

Animals↗
PubMed1981

Septic and aseptic olecranon bursitis in patients on maintenance hemodialysis.

Over a period of four years, seven of 110 maintenance hemodialysis patients developed olecranon bursitis. In all patients it appeared in the arm on which AV access was constructed but one patient also had bilateral bursitis. None of the patients gave a history of trauma or gout. Despite similar clinical presentation, culture of bursal aspirate demonstrated septic bursitis in two patients. (One diabetic, the other on steroids). Sustained pressure on the olecranon bursa during maintenance hemodialysis and/or milk trauma in the anticoagulated state may be responsible for the lesion. Infection can occur in susceptible individuals despite no visible skin infection. Local steroid instillation and patient education to avoid putting pressure on bursa during dialysis was effective therapy in the aseptic group. Multiple aspirations and antibiotics were necessary in the septic group.

Adult↗
PubMed1981

Intravitreal injection of gentamicin in rabbits. Effect of inflammation and pigmentation on half-life and ocular distribution.

Most regimens for intravitreal injection of antibiotics are based on studies in normal albino rabbits. We examined the effect of two variables, infection and pigmentation, on the ocular distribution of an intravitreal injection of 50 micrograms of gentamicin in rabbit eyes. The half-life of gentamicin in the vitreous of normal pigmented rabbits after intravitreal administration was 24 hr. Antibiotic levels in cornea and aqueous reached a peak 18 hr after injection; terminal half-lives in these sites were similar to those in vitreous. With inflammation, the half-life in the vitreous was decreased to 10 hr, and there was no accumulation of drug in anterior sites. To the extent that these data are applicable to humans, they suggest that the treatment of bacterial endophthalmitis by the intravitreal route may require more frequent injections than had been recommended on the basis of studies in normal eyes. Normal pigmented and albino rabbits showed similar levels of gentamicin in the cornea, aqueous, and vitreous; however, the drug was barely detectable in iris, choroid-retina, and sclera of pigmented animals, presumably on account of an interaction with melanin-containing tissues. This effect of pigment may explain the differences in the reported thresholds for toxicity of gentamicin with intravitreal injection.

Animals↗
PubMed1981

The difficulty of determining the route of intraocular penetration of gentamicin after subconjunctival injection in the rabbit.

In small animals such as the rabbit the ratio of eye size to body size is much larger than it is in humans. Accordingly, periocular injection of antibodies in this animal model results in significantly higher serum concentrations than does a comparable does in a human. To assess the effect of the systemic drug component on ocular penetration, we compared the levels of gentamicin in ocular tissues and fluids of the rabbit following injection of 20 mg by subconjunctival or intramuscular routes. Blood levels of gentamicin were similar with the two routes of administration. In normal rabbit eyes, no antibiotic was detectable in the vitreous humor for the first 3 hr after either subconjunctival or intramuscular injection. By 6 hr, low vitreous levels of drug were detectable after subconjunctival, but not after intramuscular, injection. Because these concentrations were so close to the threshold of sensitivity of the assay, it was not clear that the difference between the routes was significant in normal eyes. In infected eyes, the concentrations of gentamicin in the vitreous were similar after subconjunctival and intramuscular injection. These data indicate that the penetration of gentamicin in to the infected vitreous humor of rabbits after subconjunctival injection could be attributed as well to hematogenous carriage as to direct penetration. The problem in distinguishing systemic from direct transport with periocular injections may be inherent in any small animal model in which the ratio of eye size to body size is high.

Adult↗
PubMed1980

Juvenile rheumatoid arthritis. A comparison of patients from the USSR and USA.

Juvenile rheumatoid arthritis (JRA) in the Union of Soviet Socialist Republics (USSR) and the United States (USA) shows a remarkable similarity in age of disease onset, subtype onset, frequency, and most laboratory measurements. There is variation in the therapeutic approach with heavier reliance on aspirin in the USA. The evolution of JRA from onset subtype to final subtype over 5 years was the same in both groups and was independent of the type of therapy.

Adrenal Cortex Hormones↗
PubMed1980

A survey of Moraxella corneal ulcers in a derelict population.

Infection with diplobacilli of the Moraxella group was the most common cause of bacterial corneal ulcer in a population of derelict alcoholics living in the Bowery district in New York City from 1965 through 1968. No distinction could be made between Moraxella subspecies on the basis of severity of ulcer or antibiotic sensitivities. Of 100 Bowery inhabitants examined, 35 harbored Moraxella in their noses. After 1968 and coinciding with an improvement in nutrition and sanitation, but with no apparent change in the incidence of alcoholism in this population, we noted a marked decline in the incidence of corneal ulcers caused by Moraxella species.

Adult↗
PubMed1980

Basic tear flow. Does it exist?

Tear flow and volume were measured in 15 normal volunteers, divided into young and old age groups, using subjective fluorophotometric analysis and Schirmer testing with and without topical anesthesia. Proparacaine 0.5% was found to anesthetize cornea and conjunctiva better than cocaine 4% and produced fewer complications. Older subjects responded to stimulation with less reflex tearing than younger subjects, but had an identical rate of physiologic tear flow, and equivalent corneal and conjunctival sensitivity. Tear flow and volume decreased significantly below physiologic values in both age groups following topical anesthetic instillation. Lid margin and cilia stimulation increased the tear turnover rate more than 300% despite adequate topical anesthesia. Flow rates determined by Schirmer testing with topical anesthesia were higher than both physiologic tear flow and tear flow following topical anesthesia when these values were determined by fluorophotometry. As sensory input was decreased, tear secretion fell correspondingly, implying that all significant tear flow results frp, reflex secretion.

Adult↗
PubMed1980

Oxacillin for bacterial endophthalmitis: subconjunctival, intravenous, both, or neither?

We compared the intraocular concentrations of oxacillin given by continuous intravenous infusion, subconjunctival injection, or combined therapy in a rabbit model of Staphylococcus aureus endophthalmitis. At equilibrium during intravenous infusion, concentrations in the aqueous humor, cornea, and choroid-retina were 25% to 30% of the serum level; in contrast, vitreous levels were only 2% of the serum concentration. Subconjunctival injection produced extremely high levels in the cornea and aqueous and moderate concentrations in the choroid-retina; vitreous penetration remained poor (<1 microgram/ml). Combined therapy offered little advantage in terms of concentrations in the aqueous or cornea and had a modest effect on levels in the choroid-retina. Vitreous concentrations showed a striking relation to serum levels with all regimens, including subconjunctival ones; although this could have been fortuitous, it suggests an important role for the hematogenous route in this model. Only those modes of delivery producing serum concentrations greater than 50 micrograms/ml consistently resulted in vitreous levels greater than 0.4 microgram/ml. The optimal therapy of bacterial endophthalmitis may require direct intravitreal injection of antibiotic.

Animals↗
PubMed1980

[Postoperative hypalgesia following electrostimulation -- anaesthesia by stimulation of typical acupuncture points (author's transl)].

"Postoperative hypalgesia" following electroacupuncture or electrostimulation anesthesia is considered to be a notable advantage of these techniques, which supports the thesis, that endorphines may be involved in the mechanism of pain relief by these methods. After establishing definitive criteria postoperative hypalgesia was observed in 50% of patients undergoing operations on the lumbar vertebral column with electroacupuncture. A comparative investigation using psychological tests showed, that these patients are more pain tolerant than those, in whom postoperative hypalgesia was not observed. Observation alone of the patients during the postoperative period is unreliable to assess real postoperative pain relief objectively. Exact documentation and critical proof of the phenomenon of "postoperative hypalgesia" must be emphasized. These may be possible essentials to establish optimal methods of electrostimulation -- anesthesia.

Acupuncture Therapy↗
PubMed1979

Carpal tunnel syndrome in patients undergoing maintenance hemodialysis.

Five of 62 maintenance hemodialysis patients were found to have carpal tunnel syndrome, and another five had prolonged distal motor latencies. Contrary to previous reports, there was no relation between carpal tunnel syndrome and the site of vascular access. Synovial biopsy specimens from flexor tendons demonstrated edema without inflammation, suggesting that extracellular fluid volume excess in the presence of flexion and immobility during dialysis may be pathogenetically important.

Carpal Tunnel Syndrome↗
PubMed1979

Radioactive and bioassay of intraocular antibiotics: double-assay technique to compare penicillin G, cefamandole, and gentamicin in ocular tissues in vivo.

We examined the correlation between radioactive assay and trephine-discbioassay of penicillin G sodium, cefamandole nafate, and gentamicin sulfate in ocular tissues of pigmented rabbits after subconjuctival administration of antibiotic. We devised a technique whereby a single sample of tissue could be assayed by both methods. This was achieved by performing the bioassay first, then measuring the resudual radioactivity in the agar and specimens. The results of both methods were generally within 13%. An exception was gentamicin in iris and choroidretina, for which the bioassay result was strikingly less than the radioassay value. No such discrepancy was evident when similar studies were carried out with gentamicin in albino rabbits. This suggests that the phenomenon is due to tight binding of gentamicin by melanin-containing tissues. The trephine-disc bioassay provides an accurate measure of diffusible bioactive antibiotic in ocular tissues.

Animals↗