Results from tattooing port-wine hemangiomas. A long-term follow-up.

Nineteen patients who had completed their course of dermatattoo treatment for the camouflage of port-wine hemangioma were evaluated at an average of 3.1 years following completion of treatment. A panel of 7 people evaluated preoperative and postoperative photographs and judged that none of the patients were more than "50 percent improved" in the camouflaging of their hemangioma, and that most of them (15 out of 19) were either "not improved" or "25 percent improved," as compared to their original photographs. We cannot rule out the possibility that this treatment may be effective in adults, as all of our patients at the time of their first treatment were between the ages of 4 and 20 years; and most of them were between 6 and 10 years old. On the basis of this evaluation, we no longer recommend the technique of dermatattoo for camouflage of port-wine hemangioma in patients in the younger age group.     

Conversion of type II procollagen to collagen in Vitro: Removal of the carboxy-terminal extension is inhibited by several naturally occurring amino acids,polyamines, and structurally related compounds

Chick embryo sterna, which actively synthesize type II procollagen, were pulse-labeled with radioactive proline; protein synthesis was then inhibited by unlabeled proline and cycloheximide. After the inhibition of protein synthesis, several amino acids, polyamines, or structurally related compounds were added to the incubation medium. The conversion of procollagen, first to two intermediates, pC-collagen and pN-collagen, and then to collagen, was monitored by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis. The addition of 50 mm β-alanine, arginine, asparagine, glutamine, hydroxylysine, lysine, or ornithine, as well as agmatine, ?-aminocaproic acid, S-2-aminoethylcysteine, cadaverine, canavanine, putrescine, or spermine clearly inhibited the removal of the carboxy-terminal extension and pC-collagen accumulated; the removal of the amino-terminal extension was not affected. The inhibition of the conversion was reversible and unaffected by fetal calf serum. The results suggest that the conversion of type II procollagen to collagen requires at least two separate proteinases for the removal of amino-terminal and carboxy-terminal extensions. The results further suggest that naturally occurring molecules may be used to modulate the rate of conversion of procollagen to collagen, and development of analogs of these compounds may provide the means to interfere with excessive deposition of collagen in diseases with tissue fibrosis.     

The chemical identity of the immunoreactive LHRH-like peptide biosynthesized in the human placenta

Freshly obtained human placental trophoblasts were minced and pulselabeled for 30 min at 37°C with tritiated L-Tyrosine. After homogenisation, the crude extract was centrifuged and deproteinized with 10% TCA. The supernatant was defatted and the peptides concentrated through hydrophobic binding on ODS-silica cartridges. The bound, crude peptide extract was eluted and subjected to gradient, reverse-phase High Performance Liquid Chromatography. The fractions corresponding to the absorption peak of reference, synthetic LHRH were collected and extensively purified to radioactive homogeneity by further multiple HPLC. After digestion with pyroglutamate aminopeptidase, the resulting nonapeptide was manually sequenced by dansyl-Edman degradation. All the incorporated radioactivity was found to reside exclusively in residue number 4 of the nonapeptide; thus establishing for the first time the primary sequence of biosynthetic placental LHRH as: pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH₂, identical to its hypothalamic counterpart.     

Mild dehydration and atrial natriuretic peptide in young and elderly subjects.

The influence of mild dehydration on plasma levels of atrial natriuretic peptide (ANP) was studied in both young (aged 18 to 25 years) and elderly (aged 72 to 86 years) subjects. We expected that dehydration would lower ANP concentrations due to the ensuing volume contraction. A different response of the ANP hormonal system in the elderly might help to explain the observation that elderly subjects are more predisposed to dehydration as compared to young subjects. Dehydration was induced by restriction of fluid intake to 25% of normal for one day. During the study, urinary osmolality increased while osmolar clearance and body weight decreased. Basal ANP concentrations were higher in the elderly subjects. However, these levels did not change during the dehydration study neither in the young nor in the elderly subjects. This may be explained by the activation of counter-regulatory systems preventing a decrease in central blood volume and hence a decrease in ANP concentration.     

De novo biosynthesis of enkephalins and their homologues in the human placenta

Fresh trophoblastic preparations of two human placentae delivered at term were pulse labelled for 30, 120 and 240 min with tritiated L-tyrosine. After deproteinizing and defatting, the peptide extracts were first concentrated through reversible hydrophobic binding on octadecasilyl-silica particles, prior to further resolution by repetetive high-performance liquid chromatography. Four peptides were isolated and purified to radioactive homogeneity, namely Met-enkephalin, Leu-enkephalin, (Arg⁶)-Leu-enkephalin, and (Arg⁶, Arg⁷)-Leu-enkephalin. Their presence and identity were further confirmed by substractive Edman degradation and by radioimmunoassay. No detectable amounts of radioactive Dynorphin could be trapped, however. Under the incubation conditions used, reference tritiated Leu-enkephalin had a biological half-life of circa 9.5 min.     

Effect of lectins on the interactions between human peripheral blood lymphocytes and monocytes

Interactions between normal human peripheral blood T lymphocytes and monocytes were investigated by measuring the in vitro cellular adherence of these cells in the presence and in the absence of mitogens. Concanavalin A (Con A), lentil lectin (Lc), and phytohemagglutinin (PHA) in mitogenic doses increased 15 to 20 times the binding of T lymphocytes to monocytes. The lectin-induced binding was similar to that produced by neuraminidase-gal-actose-oxidase treatment. A good correlation was found between the early cellular adherence induced by these lectins and by neuraminidase-galactose-oxidase and the blastogenesis of the T lymphocytes measured after 3 days of culture by [³H]thymidine uptake. However, wheat germ agglutinin (WGA), a nonmitogenic lectin, also increased the binding of T lymphocytes to monocytes. Addition of specific carbohydrates completely inhibited the cellular interactions induced by lectins. Peanut agglutinin (PNA) induced adherence of lymphocytes only after treatment of these cells with neuraminidase. Striking differences were not found between the lectin-induced adherence observed with autologous and heterologous cells. Killing of monocytes abolished entirely the lectin-induced adherence of lymphocytes, however killed T lymphocytes were still able to interact weakly with live monocytes. Dexamethasone was found to be a potent inhibitor of mitogen-induced cellular interactions.     

Evolution des activités protéolytiques digestives chez les Jeunes Mulgilidae

Proteolytic activity in the stomach, pyloric caeca and intestine decreases with increasing size in the three fish species Mugil auratus, M. capito and M. saliens. Differences between these species are found mainly in the gastric proteolytic activity which appears to be related to diet. This activity is pronounced in M. saliens whose diet is mainly carnivorous. Comparison of regression lines relating gastric proteolytic activity to size reveals differences which distinguish M. auratus from both of the other species. Total proteolytic activity exhibits high variability depending on the types of diet.