PubMed Health⌕ Search

Biomedical subjects

L Ballowitz

Publications and source records attributed to L Ballowitz.

At least 19 recordsLinked to original sources
PubMed1984

Phototherapy in bile duct-ligated Gunn rats.

Davis and co-workers reported on the failure of phototherapy to reduce plasma bilirubin levels in the bile duct-ligated Gunn rat. We cannot confirm this conclusion. We found that the effect was reduced by a factor of 4-5. With higher effective irradiances distinct decreases of the serum bilirubin concentration can be achieved and the excretion of bilirubin photoproducts in the urine markedly will rise.

Animals↗
PubMed1982

Dose-response relationship of phototherapy for neonatal hyperbilirubinemia.

The data on dose-response relationship of phototherapy published by Tan [1977] were inserted into an e function, with energy in the exponent. The following features emerged: a) no real saturation point was reached when the spontaneous bilirubin decline was also taken into consideration, and b) a direct proportionality became evident between the two different, superimposed spectral ranges of irradiance measured and evaluated by Tan. Analogous proportionalities should be calculated for other spectral ranges and for other radiometers to simplify the comparison of irradiance data given by different authors.

Dose-Response Relationship, Radiation↗
PubMed1981

Enhancement of the phototherapy effect of albumin in Gunn rats. Investigations on the optimal albumin dose.

In pharmacokinetic studies we proved that the efficacy of phototherapy in jaundiced Gunn rats was enhanced by administration of human albumin. The albumin injections provoked a bilirubin shift from extravascular compartments into the circulation. In this study, calculations on the optimal albumin dose were carried out. After s.c. injections a good effect could be ascertained with doses between 2 and 4 g/kg body weight. After i.v. injections effective plasma concentrations could be maintained for an acceptable time by about 2g albumin/kg body weight. When overdoses were given, a considerable amount of albumin was eliminated very quickly--especially after i.v. injections with the rapid rise of the plasma level. Clinical implications are discussed.

Albumins↗
PubMed1981

[Serum proteins of growing Gunn rats. Quantitative analysis with agarose gel electrophoresis (author's transl)].

Microprocesses of quantitative agarose gel electrophoresis and biuret total protein evaluation were used for the quantitative estimation of the serum proteins of homozygous and heterozygous Gunn rats. For the analyses carried out in the course of hyperbilirubinemia, 6 microliter of serum were necessary in each case, of which 50-80 microgram were used for electrophoresis. The quantitative evaluation of the phoretogram curves plotted at two wavelengths was carried out with the aid of an analog computer. Eleven fractions were quantitatively covered by the process. Age-related concentration shifts were observed for a number of fractions, especially for albumin, transferrin, and IgG. The results obtained from a large number of animals in longitudinal and cross-sectional examination corroborate various reports found in the relevant literature.

Animals↗
PubMed1980

Bilirubin encephalopathy: changing concepts.

This overview begins with a discussion of clinical approaches to prevent brain damage in jaundiced newborns. Results of longitudinal follow-up studies are given. The main part deals with pathogenesis, whereby bilirubin albumin binding, competition by drugs, bilirubin distribution and equilibration in the body, the increased sensitivity of the infantile nervous system, the mechanism of bilirubin entry into nerve cells and the resulting intracellular damage are emphasized.

Age Factors↗
PubMed1979

Effects of riboflavin on Gunn rats under phototherapy.

Blue and white phototherapy was given to infant (and weanling) homozygous Gunn rats treated with different doses of riboflavin-5-phosphate (ribofl.5'p.) During the first hours after a flavin-injection, the effect of phototherapy with both types of fluorescent lamps was enhanced. With equal radiant power applied, the steepness of serum bilirubin decline depended on the ribofl.5'p. dose injected. After oral or cutaneous application, no similar effect occurred. After a single flavin dose, the serum bilirubin decline lasted for at least 3 hr. Nevertheless, in long-term studies with repeated injections (100 mg/kg every 48 hr), no protective effect beyond that of phototherapy alone could be ascertained on the Purkinje cells in the cerebella of the rats. In the skin of the animals, fluorescence was macroscopically noticeable after ribofl.5'p. injections. When an effective irradiance of about 3.0 mW/cm2 and a high flavin dose (100-200 mg/kg) was administered, histologic investigations of the skin in the abdominal and back region revealed a reversible inflammatory reaction with edema and morphologic changes in the epidermal cells that culminated 12-24 hr after the injection. After a further increase of the effective irradiance, tremendous vesicles on paws, ears, and tails were observed in most of the animals 24-72 hr after the flavin injections. The content of the blisters was primarily serous, later on, often hemorrhagic. Finally, necrosis developed. Acute toxicity of ribofl.5'p. differed markedly when the infant rats (homozygous jaundiced as well as heterozygous nonjaundiced) were kept in the dark or under intense blue phototherapy. Much higher doses were tolerated in the dark. Moreover, it could be demonstrated that ribofl.5'p. does not influence serum bilirubin of jaundiced Gunn rats kept in complete darkness. That suggests that the drug itself does not compete for albumin binding sites. But certain riboflavin ampules (Beflavin) contain stabilizers that considerably displace bilirubin from albumin bonds. Riboflavin disturbs direct photometric bilirubin measurements, but not the diazo reaction. When bilirubin is to be measured in sera containing riboflavin, lights must be extremely dim. Photodegradation in vitro is highly accelerated by the sensitizer.

Animals↗