Algorithm of hair restoration surgery in children

Hair is an inseparable element of external appearance of every human being. Although various fashion trends come and go, the lack of hair is for many a major aesthetic and psychological problem. Even if men's balding can be accepted as a natural phenomenon, hair loss in children is considered to be a condition demanding correction. During an 18-year period, 8440 hair restoration operations were performed at the Hair Clinic Poznan, in Poznan, Poland. Most patients were men treated for androgenic alopecia. Among the patients were 57 children in whom hair loss resulted from hereditary factors, perinatal traumas, radiotherapy, and mechanical, thermal, and chemical damage. Methods of restoration were adjusted to type of hair loss, patient age, and ability to cooperate with the surgeon. In cases of single massive scars, skin flap correction was usually used. The flaps were prepared with the use of expanders. In cases of numerous scattered defects or considerable thinning of the scalp, the method of choice was hair transplantation. The "four-hand stick-and-place" technique developed by the authors enabled the surgeon to quickly and precisely carry out the procedure. Application of varied surgery techniques in scalp reconstruction procedures in children gave very good aesthetic results with a minimal complication rate.     

Influence of boron and calcium on the tolerance to salinity of nitrogen-fixing pea plants

The effects of different levels of B (from 9.3 to 93 M B) and Ca (from 0.68 to 5.44 mM Ca) on plant development, nitrogen fixation, and mineral composition of pea (Pisum sativum L. cv. Argona) grown in symbiosis with Rhizobium leguminosarum bv. viciae 3841 and under salt stress, were analysed. The addition of extra B and extra Ca to the nutrient solution prevented the reduction caused by 75 mM NaCl of plant growth and the inhibition of nodulation and nitrogen fixation. The number of nodules recovered by the increase of Ca concentration at any B level, but only nodules developed at high B and high Ca concentrations could fix nitrogen. Addition of extra B and Ca during plant growth restored nodule organogenesis and structure, which was absolutely damaged by high salt. The increase in salt tolerance of symbiotic plants mediated by B and Ca can be co-related with the recovery of the contents of some nutrients. Salinity produced a decrease of B and Ca contents both in shoots and in nodulated roots, being increased by the supplement of both elements in the nutrient solution. Salinity also reduced the content in plants of other nutrients important for plant development and particularly for symbiotic nitrogen fixation, as K and Fe. A balanced nutrition of B and Ca (55.8 M B, 2.72 mM Ca) was able to counter-act the deficiency of these nutrients in salt-stressed plants, leading to a huge increase in salinity tolerance of symbiotic pea plants. The necessity of nutritional studies to successfully cultivate legumes in saline soils is discussed and proposed.     

Sucrose synthase catalyzes the de novo production of ADPglucose linked to starch biosynthesis in heterotrophic tissues of plants

By using barley seeds, developmental changes of ADPglucose (ADPG)-producing sucrose synthase (SS) and ADPG pyrophosphorylase (AGPase) have been compared with those of UDPglucose (UDPG), ADPG, sucrose (Suc) and starch contents. Both ADPG-synthesizing SS and AGPase activity patterns were found to correlate well with those of ADPG and starch contents. Remarkably, however, maximal activities of ADPG-synthesizing SS were found to be several fold higher than those of AGPase throughout seed development, the highest rate of starch accumulation being well accounted for by SS. Kinetic analyses of SS from barley endosperms and potato tubers in the Suc cleavage direction showed similar K(m) values for ADP and UDP, whereas apparent affinity for Suc was shown to be higher in the presence of UDP than with ADP. Moreover, measurements of transglucosylation activities in starch granules incubated with purified SS, ADP and [U-(14)C]Suc revealed a low inhibitory effect of UDP. The ADPG and UDPG contents in the transgenic S-112 SS and starch deficient potato mutant [Zrenner et al. (1995) Plant J. 7: 97] were found to be 35% and 30% of those measured in wild-type plants, whereas both glucose-1-phosphate and glucose-6-phosphate contents were found to be normal as compared with those of wild-type plants. The overall results thus strongly support a novel gluconeogenic mechanism reported previously [Pozueta-Romero et al. (1999) CRIT: Rev. Plant Sci. 18: 489] wherein SS catalyses directly the de novo production of ADPG linked to starch biosynthesis in heterotrophic tissues of plants.     

Characterization of salt stress-enhanced phosphoenolpyruvate carboxylase kinase activity in leaves of <Emphasis Type="Italic">Sorghum</Emphasis><Emphasis Type="Italic">vulgare</Emphasis>: independence from osmotic stress,involvement of ion toxicity and significance of dark phosphorylation

C(4) phosphoenolpyruvate carboxylase (PEPCase: EC 4.1.1.31) is subjected to in vivo regulatory phosphorylation by a light up-regulated, calcium-independent protein kinase. Salt stress greatly enhanced phosphoenolpyruvate carboxylase-kinase (PEPCase-k) activity in leaves of Sorghum. The increase in PEPCase-k anticipated the time course of proline accumulation thereby suggesting that water stress was not involved in the kinase response to salt. Moreover, osmotic stress seemed not to be the main factor implicated, as demonstrated by the lack of effect when water availability was restricted by mannitol. In contrast, LiCl (at a concentration of 10 mM in short-term treatment of both excised leaves and whole plants) mimicked the effects of 172 mM NaCl salt-acclimation, indicating that the rise in PEPCase-k activity resulted primarily from the ionic stress. Both NaCl and LiCl treatments increased the activity of a Ca(2+)-independent, 35 kDa kinase, as demonstrated by an in-gel phosphorylation experiment. Short-term treatment of excised leaves with NaCl or LiCl partially reproduces the effects of whole plant treatments. Finally, salinization also increased PEPCase-k activity and the phosphorylation state of PEPCase in darkened Sorghum leaves. This fact, together with increased malate production during the dark period, suggests a shift towards mixed C(4) and crassulacean acid metabolism types of photosynthesis in response to salt stress.     

Demography and nesting ecology of green iguana, Iguana iguana (Squamata: Iguanidae), in 2 exploited populations in Depresión Momposina, Colombia

We studied the demography and nesting ecology of two populations of Iguana iguana that face heavy exploitation and habitat modification in the Momposina Depression, Colombia. Lineal transect data was analyzed using the Fourier model to provide estimates of social group densities, which was found to differ both within and among populations (1.05-6.0 groups/ha). Mean group size and overall iguana density estimates varied between populations as well (1.5-13.7 iguanas/ha). The density estimates were far lower than those reported from more protected areas in Panama and Venezuela. Iguana densities were consistently higher in sites located along rivers (2.5 iguanas/group) than in sites along the margin of marshes, probably due to vegetational differences (1.5 iguanas/group). There was no correlation between density estimates and estimates of relative abundance (number of iguanas seen/hour/person) due to differing detectabilities of iguana groups among sites. The adult sex ratio (1:2.5 males:females) agreed well with other reports in the literature based upon observation of adult social groups, and probably results from the polygynous mating system in this species rather than a real demographic skew. Nesting in this population occurs from the end of January through March and hatching occurs between April and May. We monitored 34 nests, which suffered little vertebrate predation, perhaps due to the lack of a complete vertebrate fauna in this densely inhabited area, but nests suffered from inundation, cattle trampling, and infestation by phorid fly larvae. Clutch sizes in these populations were lower than all other published reports except for the iguana population on the highly xeric island of Cura?ao, implying that adult females in our area are unusually small. We argue that this is more likely the result of the exploitation of these populations rather than an adaptive response to environmentally extreme conditions.     

Reproductive aspects of Oreochromis niloticus (Perciformes: Cichlidae) at Coatetelco Lake, Morelos, Mexico

Sex ratio, size at maturity, maturity stages, fecundity and egg diameter of Oreochromis niloticus from Coatetelco Lake, Morelos State, Mexico, were studied from January to December 1993. Sex ratio (male:female) was approximately 1:1.02. Length at maturity was 117 mm (males) and 120 mm (females). The fecundity ranged between 104 and 709 eggs, with egg diameter from 1,000 to 3,000 microns. The gonadosomatic and hepatosomatic index indicate that the species breeds during summer and winter.     

Enterobius vermicularis: ancient DNA from North and South American human coprolites

A molecular paleoparasitological diagnostic approach was developed for Enterobius vermicularis. Ancient DNA was extracted from 27 coprolites from archaeological sites in Chile and USA. Enzymatic amplification of human mtDNA sequences confirmed the human origin. We designed primers specific to the E. vermicularis 5S ribosomal RNA spacer region and they allowed reproducible polymerase chain reaction identification of ancient material. We suggested that the paleoparasitological microscopic identification could accompany molecular diagnosis, which also opens the possibility of sequence analysis to understand parasite-host evolution.     

Action of Trypanosoma rangeli in infections with virulent Trypanosoma cruzi populations

In experimental murine infections with Trypanosoma rangeli it has been observed development immune response to Trypanosoma cruzi. The aim of the present work was to analyze the result of antigenic stimuli and the protective effect with T. rangeli in T. cruzi infections. Mice groups immunized with metacyclic trypomastigotes of T. rangeli (Choach -2V strain), derived from haemolymph and salivary gland and reinfected with T. cruzi virulent populations (Tulahuen strain, SA strain and Dm28c clone) from infected in vitro cells, showed decrease severity of disease outcomes, low parasitemia levels and 100% survival of all mice immunized, in comparison with groups infected only with T. cruzi populations, which demonstrated tissue affection, high parasitemia levels and the death of all animals. The above mentioned data contribute to understand the biological behaviour of T. cruzi and T. rangeli and their interaction with vertebrate host.     

Effect of exogenous melatonin on in vivo and in vitro prostaglandin secretion in Rasa Aragonesa ewes

The effect of exogenous melatonin on prostaglandin secretion was measured on Rasa Aragonesa ewes. Fourteen ewes received an 18 mg melatonin implant (M+) on 10 April and were compared with 13 control animals (without implants M-). Twenty days later, intravaginal pessaries were inserted in all animals to induce a synchronized oestrus (day 0). On day 14, ewes were injected, i.v., with 0.5 IU oxytocin. Plasma 15-ketodihydro-PGF(2alpha) (PGFM) concentrations were measured to assess uterine secretory responsiveness to oxytocin. After euthanasia, pieces of endometrium were collected to determine progesterone content and PGE(2) and PGF(2alpha) secretion in vitro, in the presence or absence of either 20 microg/ml recombinant ovine interferon-tau (roIFNt) or 1 nmol/l oxytocin in the medium. Endometrial progesterone content was similar in the two treatments (M+: 50.25+/-17.34 ng/mg tissue, M-: 43.08+/-11.21 ng/mg tissue). M+ ewes that responded to oxytocin had significantly higher plasma PGFM concentrations between 10 and 80 min after oxytocin administration, a higher mean PGFM peak (P<0.001), higher plasma PGFM levels after the challenge (P<0.05) and higher plasma progesterone concentrations (P<0.01) than control ewes. In the in vitro experiment, M+ and M- control samples secreted similar amounts of PGE(2). The presence of roIFNtau and oxytocin only stimulated PGE(2) production (P<0.05) in M- tissues. Control M+ tissues secreted higher amounts of PGF(2alpha) (P=0.07) and PGF(2alpha) secretion was significantly (P<0.01) stimulated by roIFNtau. Oxytocin produced this effect only in M- samples (P<0.01). In conclusion, although previous studies have demonstrated a positive effect of melatonin on lamb production, PGF(2alpha) secretion is higher in vitro and the PGE(2):PGF(2alpha) ratio is unfavourable in response to IFNtau, which could affect embryo survival. Whether or not these mechanisms are similar in pregnant ewes remains to be elucidated.