Age-related changes in the formation of glucocorticoid and insulin receptors during lectin-induced activation of human peripheral blood lymphocytes

The influence of age on the number of receptors for insulin and glucocorticoids on human T cells was examined. The specific binding of 125I-insulin and 3H-dexamethasone to phytohemagglutinin-(PHA)-stimulated T cells was found to decrease with age. Populations of PHA-stimulated T cells, however, are heterogeneous with respect to cell cycle phases, and cells in different cell cycle phases have been shown to bear different numbers of receptors. Therefore, it was not clear whether the measured decrease in specific binding in cultures from aged donors was due to a decreased number of activated cells or to a decreased number of binding sites per cell. In parallel to measurements of receptors, performed at different times following stimulation (20 and 44 h), numbers of cells in the different early cell cycle phases G0, G1a and G1b were quantitated by flow cytometry. In this way the receptor number per cell in each phase of the cell cycle could be determined. Receptor numbers on resting cells and in the earliest phase of activation (G1a) were found not to be influenced by age. A decreased receptor density, however, was apparent on G1b cells from aged donors.

The biological effects of photodynamic therapy on normal skin in mice--I. A light microscopic study

A light microscopic investigation of the biological effects of photodynamic therapy using hematoporphyrin derivative and red light irradiation has been carried out. HpD alone, even used at a dose of 50 mg/kg, did not cause histologically discernible changes. The irradiation alone used in this experiment caused only slight or moderate dilatation and congestion of blood vessels, which disappeared completely within several hours after light exposure. In the PDT treated mouse ears severe degeneration and necrosis of skin tissue occurred within 1-2 days. The importance of adequate drug and light doses and proper interval chosen for obtaining best therapeutic effects and protection of surrounding normal tissues was pointed out. The possible mechanism of the PDT action in vivo was briefly discussed.

The biological effects of photodynamic therapy on normal skin in mice--II. An electron microscopic study

In the present study it has been demonstrated that the ultrastructural changes in mouse ear skin after PDT action occurred much more distinct and earlier than those observed in the histological study. Various types of cells in the skin respond to the photodynamic action differently. The endothelial cells, fibroblasts and nerve fibers are most sensitive. In contrast, the keratinocytes and chondrocytes often remain rather well preserved after PDT treatment. The possible mechanism of PDT action was briefly discussed.

Serum levels of a filaricide, diethylcarbamazine citrate, in cats following different routes of administration

We have reported the blood levels of diethycarbamazine (DEC) and the persistence of the drug in the circulation for several routes and protocols of DEC administration in cats. This information will be helpful in studies using the Brugia-cat model for studies of experimental chemotherapy.

Efficacy of oral and transepidermal application of diethylcarbamazine citrate in Brugia malayi infected cats

This experimental study showed that daily oral administration of DEC at levels of 5 to 15 mg/kg/day with food for 3 weeks decreased the level of both developing and adult B. malayi in infected cats. There were no adverse reactions due to the medication. Topical application of 5% DEC in skin cream or in mineral oil appears to be effective in killing developing B. malayi in cats.

Effect of diethylcarbamazine citrate on Brugia malayi infections in cats following daily, weekly, or monthly administration

Cats with patent infections of Brugia malayi were treated by intraperitoneal injection of diethylcarbamazine citrate (DEC) for 6 consecutive days, weekly for 6 consecutive weeks or monthly for 3 months. Each cat received a total of 100 mg DEC per kg. At necropsy 7 months after infection, no living worms were recovered from any of eight cats treated weekly and only one of nine cats treated daily had a single living Brugia. Five of nine cats treated monthly and six of eight untreated controls had one or more living worms. Cats treated weekly showed a larger decline in microfilariae than those of the other treated groups. The mean microfilariae level of untreated controls increased 2-fold. At necropsy, gross appearance of regional lymphatics in daily and weekly treated cats resembled those of uninfected controls more closely than those in cats treated monthly or untreated. Differences in degree of histological changes between groups of infected cats were not apparent. Weekly administration of DEC appeared to be the most effective regimen; monthly treatment was less effective.

Determination of Co, Cu, Fe, Hg, Mn, Sb, Se and Zn in milk samples

Concentrations of Co, Cu, Fe, Hg, Mn, Sb, Se and Zn in IAEA milk (dry) standard A-11 were re-evaluated with the help of instrumental and radiochemical neutron activation analysis (NAA). The results show reasonably good agreement for Co (5.1 +/- 0.55 ng/g) and Zn (34 +/- 2.5 micrograms/g), in relation to the recommended values. For Cu (374 +/- 15 ng/g), Fe (2.4 +/- 0.34 microgram/g) and Mn (250 +/- 20 ng/g); the results obtained are lower than the reported values. Cu, Mn, and Zn were cross-checked by atomic absorption spectrophotometry (AAS). The results, Cu = 331 +/- 27 ng/g, Mn = 302 +/- 62 ng/g, and Zn = 35 +/- 1 microgram/g, fall within the range of mean values obtained by NAA. for Hg and Se, using instrumental NAA, only upper limits could be indicated; because of the low levels of concentrations of Hg and Se on one hand, and high content of P (9100 micrograms/g) in A-11 milk standard on the other, NAA coupled with radiochemistry is to be preferred for these two elements. In pooled human milk, in addition to Cu and Mn (radiochemical) and Co, Fe, Sb and Zn (instrumental), Hg and Se could also be determined non-destructively because of the favorable Hg/P and Se/P ratios in this matrix.

Platelet selenium in children with normal and low selenium intake

The concentration of selenium was determined by instrumental neutron activation analysis in erythrocytes, platelets, and plasma of eight dietetically treated children with phenylketonuria (n=6) or maple-syrup-urine disease (n=2) with low selenium intake and for ten children with normal selenium intake. The normal selenium concentration in platelets was about 600 ng/g and about five times higher than in erythrocytes of the same children. A decreased selenium concentration in platelets was seen only when the corresponding concentrations in erythrocytes and plasma were very low. This suggests a special role of selenium in platelets.

Selenium and myocardial infarction: glutathione peroxidase in platelets

The activity of the selenoenzyme glutathione peroxidase (EC 1.11.1.9) was determined in platelets of 15 patients with acute myocardial infarction and 13 control subjects. The platelets of the patients had significantly lower activities of the enzyme (P(t) greater than 0.99). This may be related to the pathogenesis of the disease.