Search PubMed⌕ Search

Biomedical subjects

R Adler

Publications and source records attributed to R Adler.

At least 163 records · Page 9Linked to original sources
PubMed1983

Taurine uptake by chick embryo retinal neurons and glial cells in purified culture.

The properties and cellular distribution of a high-affinity uptake mechanism for taurine have been investigated using separate populations of purified chick embryo neural retina neurons and glia. Purified neuronal monolayers, cultured in serum-free medium, were incubated in radioactive taurine under different conditions and studied autoradiographically and biochemically. Labeling with radioactive taurine was detected in the perikaryon of most of the neurons present in the cultures. Neuronal uptake occurred by means of a high-affinity mechanism which was completely inhibited at low temperatures or in the absence of sodium ions. The uptake was linear for at least 1 hr and, as is the case in vivo, could be inhibited by gamma-aminobutyric acid (GABA) or beta-alanine. Incubation in ouabain, glutamate, or high K+ concentrations failed to cause any increase in the amount of taurine released by neurons preloaded with the radioactive amino acid. The rather wide-spread distribution of high-affinity taurine uptake was confirmed using separate retinal cultures rich in glial cells. Practically 100% of the glial cells appeared labeled after incubation in 10(-7) M [3H] taurine, and this uptake was also inhibited by low-temperature, Na+-free medium, GABA, or beta-alanine. Several pieces of evidence indicate that high-affinity taurine uptake coexists with uptake mechanisms for other amino acids, such as GABA, glutamate, and aspartate, in retinal neurons as well as glial cells. These in vitro populations offer a promising experimental system for the investigation of the effects of taurine on retinal cells.

Amino Acids↗
PubMed1983

Pressured pattern or type A behavior in patients with peripheral arteriovascular disease: controlled retrospective exploratory study.

The question as to whether a specific behavior or type A pattern is limited to patients with coronary artery disease, or is found in atherosclerotic disease, in general, is explored. The interrelationship between a pattern of "pressured" behavior, assessed by open ended interviews, type A behavior, determined by the Bortner test, and peripheral atherosclerotic disease was investigated in a controlled retrospective study which compared three groups of 13 patients each: intermittent claudication (IC), intermittent claudication combined with coronary artery disease (CADIC) and a control group of patients without vascular disease (WVD). A pressured behavior pattern, assessed by interview, was found to be most prominent in the CADIC group, and least in the control group. The subjects with arteriovascular disease tended to exert more control over people compared to the WVD patients (Fisher's exact probability test, p = 0.05). The tendency to type A behavior, measured by means of the Bortner scale, also differentiated the three groups with CADIC scoring highest and WVD scoring lowest (analysis of variance, F = 3.944, p less than 0.05). IC patients present personality features of proneness to coronary disease. The pattern of "pressured" and type A behavior seem to correlate with the number of vascular areas involved in atherosclerotic disease.

Coronary Disease↗
PubMed1983

Polyuria in experimental intrahepatic cholangitis induced by alpha-naphthyl-isothiocyanate.

Alpha-naphthyl-isothiocyanate (ANIT)-induced intrahepatic cholangitis was associated with significant polyuria in rats. The urine output in the experimental rats was about two and a half to four fold higher than that in the controls. The polyuria was accompanied by polydypsia and disappeared when water intake was limited and controlled. The glomerular filtration rate and renal histology remained intact. Dilution and concentration capacities were preserved and the response to exogenous anti-diuretic hormone was intact. Following water deprivation, the water and electrolyte contents of the renal medulla and papilla were similar in both experimental and control rats. The excretion of a salt-load in ANIT-treated rats was delayed. It is concluded that the polyuria in ANIT-treated rats is secondary to polydypsia. The finding of preserved dilution and concentration capacities in this experimental model contrasts to that in other experimental models of hepatobiliary disease.

1-Naphthylisothiocyanate↗
PubMed1983

Posttransfusion non-A, non-B hepatitis after cardiac surgery: a prospective study.

In a prospective study of 50 recipients of HBsAg-negative blood who had undergone cardiac surgery, 4 (8%) developed acute non-A, non-B hepatitis. The patients who developed hepatitis had received significantly more units of blood or blood products than the patients who had no hepatitis. The incubation period of the disease was 4-13 weeks, 3 patients were asymptomatic with peak alaminotransferase (ALT) levels of 320-497 U/1 and 1 patient was jaundiced with a peak ALT of 3,400 U/1. 1 of the patients had high ALT levels after 21 weeks of observation, while 3 patients recovered after 7-10 weeks. It is concluded that non-A, non-B posttransfusion hepatitis in Israel is a medical problem similar to that in the USA and that the clinical picture of the disease varies from a mild asymptomatic to a symptomatic and protracted course.

Adolescent↗
PubMed1983

Children of alcoholics.

The familial nature of alcoholism is well established, but the interaction of nature and nurture remains unresolved. Other effects of alcoholic parents on the psychopathology of their children are poorly documented, with studies variably claiming that there is no discernible impact or that there is a significantly higher incidence of problems, particularly in the area of antisocial and aggressive behaviour. The relative importance of family disharmony and disruption which so often accompanies alcohol abuse, as against the impact of the alcohol abuse itself, is rarely considered. The literature on the psychopathology of children of alcoholic parents is reviewed and the relevance of the last two issues explored.

Alcoholism↗
PubMed1983

Retinomotor pigment migration in the teleost retinal pigment epithelium. I. Roles for actin and microtubules in pigment granule transport and cone movement.

In lower vertebrates, retinal pigment epithelial (RPE) cells and photoreceptors undergo dramatic "retinomotor movements" in response to changes in light conditions. In the dark, RPE pigment granules aggregate to the (choroidal) base of the RPE cells, cones elongate, and rods contract. In the light, movements are reversed: pigment granules migrate out into the long apical projections of the RPE cells, cones contract, and rods elongate. In this report the time courses of dark-induced pigment aggregation and light-induced dispersion have been characterized (and compared to cone movements) in the blue stripe grunt, Haemulon sciurus. It was found that aggregation and dispersion occur at linear rates of 3.4-3.5 microns/min and that RPE movements are kinetically independent from cone movements induced by the same changes in light conditions. The roles of actin and microtubules in RPE and cone movements were also investigated by using the actin-inhibitors, cytochalasins-B and -D, and the microtubule inhibitor, colchicine. Light-induced pigment dispersion, as well as maintenance of the fully dispersed (light-adapted) position appear to require actin-dependent processes. Intraocularly injected cytochalasins-B and -D fully prevented pigment dispersion when administered to dark-adapted animals immediately prior to their exposure to light, and caused pigment aggregation to the RPE cell base when administered to fully light-adapted animals. Ultrastructural studies showed that actin filaments, which in untreated retinas were found closely associated with pigment granules and the plasma membrane, were disrupted after cytochalasin-B treatment. Both dispersive and aggregative pigment movements within the cell body appeared to require microtubule-dependent processes. Intraocularly injected colchicine disrupted microtubules and blocked pigment granule translocation in both directions in the cell body. A hypothetical model to explain pigment movements in response to changes in light conditions is proposed based on these observations as well as on data from the literature.

Actins↗
PubMed1982

Hyperuricemia in diarrheal dehydration.

Serum uric acid levels were measured in 133 dehydrated patients admitted with diarrhea. Elevated levels were found in 80% of the patients; the highest was 38 mg/dL. Serum uric acid was correlated with serum urea nitrogen and the levels tended to be higher in patients with hypernatremia. The serum uric acid levels returned toward normal with rehydration, and no specific therapy was necessary.

Blood Urea Nitrogen↗
PubMed1982

Regulation of neurite growth in purified retina neuronal cultures: effects of PNPF, a substratum-bound, neurite-promoting factor.

The responses of chick embryo retina neurons to the substratum-bound, neurite-promoting factor "PNPF" were studied using glia-free, purified neuronal monolayers. Polyornithine-coated dishes were exposed before cell seeding to either serum-containing culture medium (PNPF(-) substratum) or to the same medium supplemented with 25% rat schwannoma conditioned medium, a source of PNPF (PNPF(+) substratum). The dishes were thoroughly rinsed before receiving a suspension of 8 day chick embryo neural retina cells in serum-free medium. The presence of PNPF on the substratum determined a dramatic increase in the relative frequency of neurite-bearing cells in the cultures. After 6 hours in vitro PNPF(+) cultures contained 45% neurite-bearing cells as compared with 5-7% on PNPN(-) substrata. At 72 hours those values increased to 60% on PNPF(+) and to 40% on PNPF(-) substrata. PNPF(+) cultures also showed longer and/or more highly branched neurites, resulting in the formation of complex neurite networks. Moreover, a cell type characterized by the presence of a very long neurite could be seen on PNPF(+) but not on PNPF(-) substrata. Six hour cultures were used to analyze in more detail the response of retinal neurons to PNPF. Addition of fetal calf serum to the medium determined a concentration-dependent inhibition of neurite formation on PNPF(+) substrata. On the other hand, pretreatment of PNPF(+) substrata with concanavalin A also blocked the neurite-promoting effect of the factor. This concentration-dependent inhibitory effect of concanavalin A could be eliminated by the specific sugar alpha-methyl-D-mannoside. Wheat germ agglutinin, another lectin known to react with PNPF, did not cause any reduction in the neurite-promoting activity of this factor. Wheat germ agglutinin showed neurite-promoting properties of its own in control experiments using PNPF(-) substrata. The results indicate that the target spectrum of PNPF is broader than it was originally thought. Together with other reports from the literature, they also support the perception of neurite development as a cellular activity subject to complex regulatory mechanisms.

Animals↗
PubMed1982

GABA uptake and release in purified neuronal and nonneuronal cultures from chick embryo retina.

Uptake and release of gamma-aminobutyric acid (GABA) have been studied using glia-free, purified neuronal cultures from 8-day chick embryo retina. At 3 days in vitro 65% of the neurons showed high-affinity GABA uptake. These neurons appeared heavily labeled after incubation in 5 X 10(-8) M [3H]GABA, but no labeling was detected when the incubation was carried out at 4 degrees C, or in the absence of Na+ ions. Diaminobutyric acid (DABA) also blocked completely the neuronal uptake of GABA, while beta -alanine was ineffective at similar concentrations. At 6 days in vitro Na+- and temperature-dependent GABA uptake was present in 50% of the neurons. In addition, in 80% of those neurons the uptake was insensitive to DABA or beta -alanine, whereas in the remaining 20% it was blocked by DABA but not by beta -alanine. Important developmental changes were also found in the capacity of the neurons to release GABA into the medium. Spontaneous GABA release (i.e. that taking place in regular medium, containing 5 mM K+) was higher at 3 than at 6 days in vitro. However, increasing the K+ concentration to 56 mM had minimal effects at 3 days in vitro, but induced a 2 to 3-fold increase in GABA release at 6 days in vitro. This K+-induced release appeared to be Ca2+-dependent, since it was substantially reduced the presence of 10 mM Co2+. Cultures containing a confluent monolayer of nonneuronal flat cells were generated by seeding retinal cell suspensions on poorly adhesive substrata. Retina nonneuronal cells showed, during the first 10 days in vitro, a high-affinity mechanism for GABA uptake which was Na+- and temperature-dependent, and was reduced by 85% by DABA but was practically unaffected by beta-alanine. This uptake mechanism seemed to be lost towards the end of the second week in vitro, and could not be detected after 21 days culture.

Aminobutyrates↗
PubMed1982

Lectin reactivity of PNPF, a polyornithine-binding neurite-promoting factor.

The fate of dissociated neurons from 8-day chick embryo ciliary ganglia, cultured in serum-containing media on polyornithine substrata, is influenced by two different macromolecular factors. The neurons will die within 24 h in the absence of CNTF, the eye-derived ciliary neuronotrophic factor. Even when supported by CNTF, however, ciliary neurons do not grow neurites unless the polyornithine substratum is coated with PNPF, a polyornithine-binding neurite-promoting factor. PNPF activity present in rat Schwannoma-conditioned medium has been shown to behave as a large, acidic, trypsin-sensitive molecule. In the experiments reported here the lectin reactivity of PNPF has been investigated. Using lectin affinity chromatography PNPF was found to bind to concanavalin A and wheat germ agglutinin from which it could be respectively eluted with the specific sugars alpha-methyl-D-mannoside and N-acetyl-D-glucosamine. PNPF did not bind to Ulex europaeus or Dolichus biflorus agglutinins. Pretreatment of polyornithine-bound PNPF with concanavalin A before cell seeding prevented neurite outgrowth from ciliary neurons in a dose-dependent manner, without affecting neuronal survival. This inhibitory effect of concanavalin A could be removed with alpha-methyl-D-mannoside. Wheat germ agglutinin failed to inhibit the neurite-promoting effects of polyornithine-bound PNPF.

Animals↗