Randomized, double-blind clinical trial of topical imiquimod 5% with parenteral meglumine antimoniate in the treatment of cutaneous leishmaniasis in Peru.

BACKGROUND: Current treatments for cutaneous leishmaniasis are limited by their toxicity, high cost, and discomfort and the emergence of drug resistance. New approaches, including combination therapies, are urgently needed. We performed a double-blind, randomized trial of therapy with parenteral antimony plus topical imiquimod, an innate immune-response modulator, versus therapy with antimony alone, in subjects with cutaneous leishmaniasis for whom an initial course of antimony therapy had failed. METHODS: Forty subjects with clinical resistance to antimony were recruited in Lima, Peru, between February 2001 and December 2002. All subjects received meglumine antimoniate (20 mg/kg/day im or iv) and were randomized to receive either topical imiquimod 5% cream (Aldara; 3M Pharmaceuticals) or vehicle control every other day for 20 days. Lesions and adverse events were evaluated during treatment and at 1, 2, 3, 6, and 12 months after the treatment period. RESULTS: The mean number of lesions was 1.2 per person; 71% of the lesions were facial and 76% were ulcerative. There were no major differences between the groups, and all but 2 subjects completed therapy. Mild adverse events were reported by 73% of the subjects, but only erythema occurred more commonly in the imiquimod group (P < or = .02). Lesions resolved more rapidly in the imiquimod group: 50% of the imiquimod group achieved cure at 1 month after the treatment period versus 15% of the vehicle cream group (P < or = .02); 61% of the imiquimod group at 2 months versus 25% of the vehicle cream group (P < or = .03); and 72% of the imiquimod group at 3 months versus 35% of the vehicle cream group (P < or = .02). Residual scarring in the imiquimod group was less prominent than in the vehicle cream group. CONCLUSIONS: Combined antimony plus imiquimod treatment was well tolerated, accelerated healing of lesions, and improved scar quality. This therapy may have particular advantages for subjects with facial lesions.

Direct regulation of the Microphthalmia promoter by Sox10 links Waardenburg-Shah syndrome (WS4)-associated hypopigmentation and deafness to WS2.

The transcription factor Sox10 is genetically linked with Waardenburg syndrome 4 (WS4) in humans and the Dominant megacolon (Dom) mouse model for this disease. The pigmentary defects observed in the Dom mouse and WS4 are reminiscent of those associated with mutations in the microphthalmia (Mitf) gene, which encodes a transcription factor essential for the development of the melanocyte lineage. We demonstrate here that wild type Sox10 directly binds and activates transcription of the MITF promoter, whereas a mutant form of the Sox10 protein genetically linked with WS4 acts as a dominant-negative repressor of MITF expression and can reduce endogenous MITF protein levels. The ability of Sox10 to activate transcription of the MITF promoter implicates Sox10 in the regulation of melanocyte development and provides a molecular basis for the hypopigmentation and deafness associated with WS4.

Regulation of the microphthalmia-associated transcription factor gene by the Waardenburg syndrome type 4 gene, SOX10.

The absence of melanocytes from the cochlea and epidermis is responsible of deafness and hypopigmentation, two symptoms shared by the four Waardenburg syndrome (WS) subtypes. Microphthalmia-associated transcription factor (MITF) controls melanocyte survival and differentiation. Mutations, which impair MITF function or expression, result in an abnormal melanocyte development leading to the WS2. WS1 and WS3 are caused by mutation in the gene encoding the transcription factor Pax3, which regulates MITF expression. Recently, mutations in SOX10, a gene encoding a SRY-related transcription factor, have been reported in patients with WS4. However, the molecular basis of the defective melanocyte development in these patients remained to be elucidated. In the present report, we demonstrate that Sox10 is a strong activator of the MITF promoter, and we identify a Sox10 binding site between -264 and -266 of the MITF promoter. Finally, we show that three SOX10 mutations found in WS4 abolish the transcriptional activity of the resulting Sox10 proteins toward the MITF promoter. Taken together, our observations bring new and meaningful information concerning the molecular process that leads to a defective melanocyte development in WS4 patients with SOX10 mutations.

TFE3, a transcription factor homologous to microphthalmia, is a potential transcriptional activator of tyrosinase and TyrpI genes.

Microphthalmia gene encodes a basic helix-loop-helix-leucine zipper (bHLH-Zip) transcription factor involved in the development of the melanocyte lineage and plays a key role in the transcriptional regulation of the melanogenic enzymes, tyrosinase and TyrpI. Recently, we have shown that Microphthalmia mediates the melanogenic effects elicited by alphaMSH that up-regulates the expression of tyrosinase through the activation of the cAMP pathway. Therefore, Microphthalmia appears as a principal gene in melanocyte development and functioning. Among the transcription factors of the bHLH-Zip family, TFE3 and TFEB show a remarkably elevated homology with Microphthalmia. These observations prompted us to investigate the role of TFE3 and TFEB in the regulation of tyrosinase and TyrpI gene transcription. We show in this report that overexpression of TFE3 stimulates the tyrosinase and TyrpI promoter activities, while TFEB acts only on the TyrpI promoter. TFE3 and TFEB elicit their effects mainly through the binding to Mbox (AGTCATGTGCT) and Ebox motifs (CATGTG) of tyrosinase and TyrpI promoters. In B16 melanoma cells, the high basal expression of TFE3 is down-regulated by forskolin and by alphaMSH. Interestingly, endogenous TFE3 cannot bind as homodimers to the Mbox, and we did not detect TFE3/Mi heterodimers. According to these data, TFE3 is clearly endowed with the capacity to regulate tyrosinase and TyrpI gene expression. However, TFE3 binding to the melanogenic gene promoters is hindered, thereby preventing its potential melanogenic action. In specific physiological or pathological conditions, the recovery of its binding function would make TFE3 an important element in melanogenesis regulation.

Thyrotropin-like immunoreactivity in the developing chicken retina.

In this paper we analysed the presence and localisation of thyrotropin during retinal development in Gallus domesticus. Specific thyrotropin-like immunohistochemical staining was observed from the beginning of the second incubation week to one day post-hatching in chicken retina. Thyrotropin is a 28.3 KDa glycoprotein, synthesised by the anterior pituitary gland, and it is implicated in the stimulation of the synthesis and release of thyroid hormones. Until now, the action of thyrotropin has been established exclusively in hormonal terms. Recently, this glycoprotein has been localised in synaptic processes in the human retina by using a specific antiserum (Fdez-Trujillo et al., 1995). To the best of our knowledge this report is the first time that thyrotropin has been immunocytochemically demonstrated in the chicken retina. The pattern of thyrotropin-like immunoreactivity suggests that this glycoprotein could act as modulator of synaptic transmission, but it may also play a much broader role in regulating trophic functions.

Presence and distribution of 5HT-, VIP-, NPY-, and SP-immunoreactive structures in adult mouse lung.

A large number of biologically active substances have been identified and characterised in the respiratory tract of several mammals. These substances (amines and peptides) exert important regulatory influences on respiratory functions, and they act as neurotransmitters/neuromodulators, both being released from nerve terminals as neuroendocrine cells. However, these substances can also have other effects which suggest a paracrine action. Thus, to understand the role of amines and peptides in the lung, it is important to explore their localisation in different species. By using immunocytochemical staining methods we have studied the morphology and distribution of serotonin-, Substance P-, neuropeptide Y- and VIP-like immunoreactivity in the adult mouse lung. Moreover a pretreatment with colchicine, pargyline and 5-hydroxytryptophan as staining enlargement method was made. A widespread distribution of isolated endocrine cells and neuro-epithelial bodies containing 5HT-like immunoreactivity was recorded within the lung. NPY-like immunoreactive nerve fibres were localised in the airway smooth muscle and surrounding the blood vessels. VIP-like immunoreactivity was revealed in single cells as well as in some nerve fibres and ganglia around the blood vessels and in the bronchial smooth muscle. SP-like IR was observed in nerve fibres located in the smooth muscle of the airways, surrounding bronchi and bronchioli but not next to the intrapulmonary blood vessels. Their localisation both in cells and nerve fibres of the respiratory system suggests that they play a role in the regulatory function of the mouse respiratory tract, exerting their influence by endocrine, paracrine, neurosecretory pathways or a combination of all of these.

Study of the distribution of glycosidic residues in eccrine sweat glands, with special reference to the content of sialic acid.

We used a group of lectins (Con-A, WGA, SBA, DBA, RCA-1, UEA-1), enzymes (neuraminidase digestion) and conventional histochemical techniques (periodic acid-Schiff reaction and reduction-saponification-Schiff reaction) in order to detect the presence of glycoproteins rich in sialic and neuraminic acids in the human eccrine sweat glands. Using both identification systems, our results showed an abundant secretion, rich in C8Oxi-acylated sialic acid.

Calcitonin gene-related peptide immunoreactivity in adult mouse lung.

Calcitonin gene-related peptide (CGRP) is a 37 amino acid peptide coded by the calcitonin gene that is produced by thyroid C cells and medullary carcinoma. It is also widely distributed in neurons and endocrine cells throughout the body. The presence of CGRP in the lungs suggests that this peptide exerts important regulatory actions at this level, and it can act like a neuroregulator released both from nerve terminals and neuroendocrine (NE) cells. To understand the role of CGRP in the lung, it is important to explore its localization in different species. In this paper, we analyse the presence and localization of CGRP in the adult mouse lung using an immunocytochemical staining method. Our results show a widespread distribution of this peptide in isolated neuroendocrine cells and neuroepithelial bodies (NEBs), as well as in nerve fibres distributed in many areas of the lung, including bronchi and bronchioli. These fibres are in close contact with epithelium, neuroendocrine cells and smooth muscle. In addition, some immunostained nerve cell bodies and immunoreactive intrinsic ganglion cells can be shown. CGRP has been previously demonstrated in the mammalian lung using immunocytochemistry. To the best of our knowledge, this is the first time that CGRP has been immunocytochemically demonstrated in the mouse lung both in NE cells, NEBS, ganglion cells and in nerve fibres which are related to neuroendocrine cells.

Thyrotropin-like immunoreactivity in human retina: immunoreactive co-localization in ganglion cells and perivascular fibers.

The present immunocytochemical study has demonstrated immunoreactive thyrotropin-like ganglion cell populations as well as perivascular fibers in the human retina by using specific antiserum. Thyrotropin is a pituitary glycopeptide involved in the synthesis and release of thyroid hormones. The existence and functions of peptides in vertebrate retinas are still not well known. Many authors have reported neuropeptide immunoreactivity in the human retina which have had their functions established in the neuroregulatory processes of vision. Moreover, some authors have reported the possibility that the fiber terminal of peptidergic neurons may also be a blood vessel. The appearance of immunoreactive-cells in human retina, e.g. existence of retinal ganglion cells with thyrotropin-like immunoreactivity, indicates the existence of specific mechanisms that would be mediated by these peptides which are located near immunoreactive ganglion cells. We hypothesize that there is an intrinsic mechanism for blood flow control, mediated by retinal ganglion cells which may regulate vessel diameter according to its luminous stimuli. No-one has demonstrated the presence or the functional existence of thyrotropin-like immunoreactive structures in the vertebrate retina, or on the side of the pituitary-thyroid axis. To the best of our knowledge this is the first time that thyrotropin has been immunocytochemically demonstrated in the human retina. Thus, we suggest that thyrotropin acts as a neuromodulator in the human retina, which is implicated in blood flow control.

Immunocytochemical distribution of serotonin and neuropeptide Y (NPY) in mouse adrenal gland.

By the use of immunocytochemical staining methods, we studied the morphology and distribution of 5HT and NPY immunoreactive cells and fibres in the mouse adrenal gland. The 5HT-immunoreactive cells were numerous and widely localized in the medullar tissue. These cells were arranged in three cellular types with regard to their morphological and immunocytochemical features. One of them showed cells with polygonal shape, being intensified like the typical medullary chromaffin cells. These immunoreactive cells were observed arranged in medullar islets. The second 5HT-immunoreactive cellular type was constituted by cells with polygonal shape and strong immunoreactivity. The third one was formed by cells with immunoreactive prolongations. We found some islets of chromaffin non-immunoreactive cells surrounded by immunostained cells. We also observed some 5HT-immunoreactive nerve fibres in the medullar tissue. NPY-like immunoreactivity was detected in both chromaffin and ganglion cells in adrenal medulla. NPY-like immunoreactivity was also detected in nerve fibres at cortical level. In a few cases, we observed medullar 5HT- and NPY-immunoreactive tissue in the adrenal cortex (monotremas).

Teoria y solucionario de quimica general

Contenido:1.Leyes de las combinaciones quimicas 2.La materia gaseosa 3.Balance de materia.-Ecuaciones quimicas.-Estequiometria 4.Disoluciones 5.Equilibrio quimico 6.Equilibrio ionico-Acidos y bases 7.Termodinamica 8.Electroquimica.