Dermoscopy of discoid lupus erythematosus.

BACKGROUND: Dermoscopy is useful in evaluating skin tumours, but its applicability also extends into the field of inflammatory skin disorders. Discoid lupus erythematosus (DLE) represents the most common subtype of cutaneous lupus erythematosus. While dermoscopy and videodermoscopy have been shown to aid the differentiation of scalp DLE from other causes of scarring alopecia, limited data exist concerning dermoscopic criteria of DLE in other locations, such as the face, trunk and extremities. OBJECTIVE: To describe the dermoscopic criteria observed in a series of patients with DLE located on areas other than the scalp, and to correlate them to the underlying histopathological alterations. METHODS: DLE lesions located on the face, trunk and extremities were dermoscopically and histopathologically examined. Selection of the dermoscopic variables included in the evaluation process was based on data in the available literature on DLE of the scalp and on our preliminary observations. Analysis of data was done with SPSS analysis software. RESULTS: Fifty-five lesions from 37 patients with DLE were included in the study. Perifollicular whitish halo, follicular keratotic plugs and telangiectasias were the most common dermoscopic criteria. Statistical analysis revealed excellent correlation between dermoscopic and histopathological findings. Notably, a time-related alteration of dermoscopic features was observed. CONCLUSIONS: The present study provides new insights into the dermoscopic variability of DLE located on the face, trunk and extremities.

Clinical, dermoscopic and histopathologic features of genital and extragenital lichen sclerosus.

BACKGROUND: Little is currently known about the dermoscopic patterns of genital and extragenital lichen sclerosus (LS). In order to evaluate and compare the dermoscopic and histopathologic patterns of genital and extragenital lichen sclerosus, a retrospective analysis of clinical, dermoscopic and histopathologic features of genital and extragenital LS, collected between March 2010 and December 2011 at four dermatology clinics in Greece, Italy, Serbia and Uruguay was performed. OBSERVATIONS: A total of 29 lesions from 14 (mean age 62.8 years) and 12 (mean age 53.5 years) patients with genital and extragenital LS, respectively were analyzed. Mean duration of disease was 3.5 years for genital and 1.8 years for extragenital LS. White-yellowish structureless areas were seen in all cases of genital and extragenital LS; however linear vessels occurred at higher frequency in genital than in extragenital lesions (85.7% vs. 33.3%, respectively). Extragenital LS revealed two different time-related patterns: keratotic plugs were more prevalent in lesions with short duration (<2 years), whereas longer persisting lesions appeared atrophic and revealed fine chrysalis structures. CONCLUSIONS: Our morphologic study provides novel insights into the morphologic diversity of LS at different body sites and different stages of progression.

Blue-black rule: a simple dermoscopic clue to recognize pigmented nodular melanoma.

BACKGROUND: Dermoscopy improves melanoma recognition, but most criteria were described in the context of superficial spreading melanoma. OBJECTIVES: To test whether pigmented nodular melanoma could be recognized dermoscopically by the presence of a combination of blue and black colour within the lesion. METHODS: Dermoscopic images of histopathologically diagnosed pigmented nodular tumours with no (or only minimal) flat component were evaluated for the presence of standard melanoma criteria and for the presence of a new feature named blue-black (BB) colour. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for standard criteria and BB feature in relation to the diagnosis of melanoma and to diagnosis of malignancy. RESULTS: Of 283 lesions, 160 were malignant, including 78 (27·6%) melanomas, and 123 were benign. The BB feature and the standard criteria had 78·2% and 43·6% sensitivity for melanoma, respectively, whereas a combined method based on the presence of either the BB feature or one (or more) of the standard criteria reached 84·6% sensitivity, with 80·5% specificity and 93·2% negative predictive value. Sensitivity values for malignant lesions were only 24·4%, 56·9% and 60% for standard criteria, BB feature and the combined method, respectively. However, the combined method gave 91·9% specificity and 90·6% positive predictive value for malignancy. CONCLUSIONS: Using a method based on the BB feature or one of the standard melanoma criteria, only 9·4% of positive pigmented nodular lesions were found to be benign and only 6·8% of negative lesions were found to be melanoma histopathologically.

Endoscopic correction of vesicoureteric reflux--our thirteen years' experience.

AIM OF THE STUDY: We review our thirteen years' experience with the endoscopic treatment of primary vesicoureteric reflux (VUR). METHODS: We retrospectively reviewed the charts of 81 patients with primary vesicoureteric reflux who were treated endoscopically. The study included 61 girls and 20 boys aged 3 - 15 years. Twenty-eight patients had unilateral reflux, and 53 patients had bilateral reflux. Endoscopic correction with Teflon paste was done in 64 patients, and endoscopic treatment with Deflux was done in 17 patients. A total of 134 ureters were treated. RESULTS AND CONCLUSION: Reflux was corrected in 87 ureters (64.9 %) after the first injection. The second injection resolved reflux in an additional 20 ureters (14.9 %). Reimplantation was necessary in 4 patients (4.9 %). Overall success rate of the endoscopic treatment was 85.0 %. Reflux was completely absent in 79.8 % of the treated patients, and 5.2 % of the patients had a decreased grade of reflux after the procedure. Treatment was unsuccessful in 3.0 % of the patients. In seven patients spontaneous resolution of the persisting reflux occurred. Endoscopic correction should be performed in all patients with grade two, three and four reflux. Grade one reflux should be treated conservatively, and grade five reflux should be treated surgically. Since Deflux is a biodegradable material, most of the patients should be treated bilaterally, even if they have only grade one reflux. Endoscopic correction of primary vesicoureteric reflux is an easy, simple, fast and safe procedure that, in most cases, prevents regurgitation of urine from the bladder to the upper parts of the urinary system.

Expression of receptor protein-tyrosine phosphatase alpha, sigma and LAR during development of the zebrafish embryo.

Receptor protein-tyrosine phosphatases (RPTPs) are key players in Drosophila development. To study the role of RPTPs in vertebrate development, we have cloned zebrafish (zf) RPTPs, including RPTP alpha (RPTPalpha), RPTP sigma (RPTPsigma) and LAR. These three RPTPs are broadly transcribed in early development. At 24h post fertilisation (hpf), all three genes are expressed in the nervous system in partially overlapping patterns. At 3 days post fertilisation zf-RPTPalpha and zf-LAR show similar expression patterns in the central nervous system (CNS), the pharyngeal arches, the pectoral fins and the spinal cord. Interestingly, zf-LAR is uniquely expressed in the neuromast cells, whereas zf-RPTPsigma expression is confined to the central nervous system.

Vasa protein expression and localization in the zebrafish.

Primordial germ cell (PGC) development in the zebrafish is poorly understood. The expression of vasa RNA, the only molecular marker so far found to be expressed in fish PGCs, suggests its function in the establishment of the germline. The protein product of vasa is present throughout the life cycle in the germline of Drosophila, Caenorhabditis and Xenopus. The expression pattern of the Vasa protein in zebrafish, is still unresolved. We generated an anti-Vasa polyclonal antibody and show that it is maternally expressed initially throughout the embryo. Interestingly, from the two-cell- to the 1000-cell stage the protein is highly concentrated in two 'dots' near the center of the blastomeres and as such remains longest detectable in the animal pole blastomeres. The first distinct cell-specific expression occurs at 60% epiboly on one side of the blastoderm margin. The Vasa protein in the PGCs is organized in a subcellular granular-like conformation which is dynamic throughout development.

Comparison of sequence and function of the Oct-6 genes in zebrafish, chicken and mouse.

To examine the role of the Oct-6 gene in Schwann cell differentiation we have cloned and characterized the chicken and zebrafish homologues of the mouse Oct-6 gene. While highly homologous in the Pit1-Oct1/2-Unc86 (POU) domain, sequence similarities are limited outside this domain. Both genes are intronless and both proteins lack the amino acid repeats that are a characteristic feature of the mammalian Oct-6 proteins. However as in mammals, the aminoterminal parts of the chicken and zebrafish Oct-6 proteins are essential for transactivation of octamer containing promoters. By immunohistochemistry we have found that the chicken Oct-6 protein is expressed in late embryonic ensheathing Schwann cells of the sciatic nerve and is rapidly downregulated when myelination proceeds. This expression profile in glial cells is identical to that in the mouse and rat. Furthermore the zebrafish Oct-6 homolog is expressed in the posterior lateral nerve at a time when it contains actively myelinating Schwann cells. Thus despite extensive primary sequence divergence among the vertebrate Oct-6 proteins, the expression of the chicken and zebrafish Oct-6 proteins is consistent with the notion that Oct-6 functions as a 'competence factor' in promyelin cells to execute the myelination program.

Protein kinase A is involved in the induction of early mesodermal marker genes by activin.

In this study we have investigated the role of cAMP-dependent protein kinase A (PKA) in the induction of the early mesodermal marker genes goosecoid and no tail by activin in zebrafish embryos. We show that upon treatment with activin, zebrafish blastula cells exhibit a rapid and transient increase in PKA activity. In these cells, activin rapidly induces the expression of the immediate early response genes goosecoid and no tail. Stimulation and inhibition of PKA by activin, respectively, enhances and reduces the induction of goosecoid and no tail mRNA expression. Similar effects of PKA stimulation and inhibition on the induction by activin of a 1.8 kb zebrafish goosecoid promoter construct were observed. The induction by activin of a fragment of the zebrafish goosecoid promoter that mediates an immediate early response to activin is blocked by inhibition of PKA. Activation of PKA alone has no effect in these experiments. Finally, inhibition of PKA in whole embryos by overexpression of a dominant negative regulatory subunit of PKA reduces the expression of no tail and goosecoid, whereas the expression of even-skippedl remains unaltered. Overexpression of the catalytic subunit of PKA in embryos does not affect expression of goosecoid, no tail or even-skippedl. These data show that in dissociated blastulae, PKA is required, but not sufficient for activin signalling towards induction of goosecoid and no tail. In intact zebrafish embryos, PKA contributes to induction of goosecoid and no tail, although it is not required or sufficient.

Effects of retinoic acid on the expression of retinoic acid receptors during zebrafish embryogenesis.

The cDNAs encoding the zebrafish homologs of retinoic acid receptor alpha(zRAR alpha) and gamma (zRAR gamma) were isolated and their expression studied in normal and retinoic acid (RA) treated embryos. Expression boundaries in the central nervous system are clearly different from those observed in the mouse, which can only partly be explained by morphogenetic differences. Treatment of embryos with RA induces ectopic zRAR gamma expression in anterior brain structures and both zRAR alpha and zRAR gamma expression in the eyes. Furthermore, striking differences occur in the zRAR gamma expression pattern in pharyngeal arch mesenchyme. Since the development of all of these structures has been shown to be affected by exogenous RA, our data suggest a role for zRAR alpha and zRAR gamma in the establishment of the RA phenotype in zebrafish.

Regulation of the zebrafish goosecoid promoter by mesoderm inducing factors and Xwnt1.

Goosecoid is a homeobox gene that is expressed as an immediate early response to mesoderm induction by activin. We have investigated the induction of the zebrafish goosecoid promoter by the mesoderm inducing factors activin and basic fibroblast growth factor (bFGF) in dissociated zebrafish blastula cells, as well as by different wnts in intact embryos. Activin induces promoter activity, while bFGF shows a cooperative effect with activin. We have identified two enhancer elements that are functional in the induction of the goosecoid promoter. A distal element confers activin responsiveness to a heterologous promoter in the absence of de novo protein synthesis, whereas a proximal element responds only to a combination of activin and bFGF. Deletion experiments show that both elements are important for full induction by activin. Nuclear proteins that bind to these elements are expressed in blastula embryos, and competition experiments show that an octamer site in the activin responsive distal element is specifically bound, suggesting a role for an octamer binding factor in the regulation of goosecoid expression by activin. Experiments in intact embryos reveal that the proximal element contains sequences that respond to Xwnt1, but not to Xwnt5c. Furthermore, we show that the distal element is active in a confined dorsal domain in embryos and responds to overexpression of activin in vivo, as well as to dorsalization by lithium. The distal element is to our knowledge the first enhancer element identified that mediates the induction of a mesodermal gene by activin.

Active complex formation of type I and type II activin and TGF beta receptors in vivo as studied by overexpression in zebrafish embryos.

We have investigated the involvement of activin receptors and TGF beta type I receptor in zebrafish development. Overexpression of either full-length or a truncated form of mouse ActR-IIA interferes with the development. Different splice variants of mouse ActR-IIB have distinct effects; ActR-IIB4 induces abnormal embryos, whereas ActR-IIB2 does not. Activin and TGF beta type I receptors can induce axis duplications. Co-expression of ActR-IA or ActR-IB with the type II activin receptors results in a synergistic increase of the frequency of axis duplication. Moreover, ActR-IIB2 is synergistic with ActR-IA and ActR-IB, demonstrating that ActR-IIB2 can interact with the zebrafish ligand. Overexpression of TGF beta R-I with ActR-IIA or ActR IIB4 results in a synergistic increase in frequency of abnormal embryos, whereas in combination with ActR-IIB2 no such increase occurs.

Polar ionic currents around embryos of Lymnaea stagnalis during gastrulation and organogenesis.

Embryos of Lymnaea stagnalis generate ionic currents which can be measured with the vibrating probe. Here we investigated the presence and origin of the currents during late embryonic development. During gastrulation the current pattern correlates with the animal-vegetal polarity and during organogenesis it is correlated to the newly formed antero-posterior axis. The origin of the ionic currents was studied by inhibition of the Na+/K(+)-pump with ouabain and by enzyme-cytochemical detection of the Ca(2+)-pump. Ouabain treatment resulted in a reduced current density around the embryo, indicating that the Na+/K(+)-pump contributes significantly to the net current. The Ca(2+)-pump was found to be localized in the vegetal blastomeres during gastrulation and in the larval kidney during organogenesis. It seems likely that this Ca(2+)-pump renders only a minor contribution to the net current in late embryonic development. Ionic currents have now been described in Lymnaea from the uncleaved egg up to the juvenile snail. During this period the overall current pattern changes only twice, demonstrating that the voltage gradient generated by the embryo remains stable during prolonged periods in development.

Germ line development in fishes.

Classical work on germ cells in fishes has dealt with three main issues; their embryonic origin, the proliferation, and migration pathway during embryonic and larval development. Until recently, primordial germ cells (PGCs) have been studied in a number of fishes using morphological criteria only. The identification of the Drosophila vasa homolog gene of zebrafish now allows comparison of these morphological data with vasa RNA expression patterns in zebrafish. Teleost PGCs can be distinguished from somatic cells by their distinct morphology, at the earliest during gastrulation, and in most fishes their number varies between 10 and 30 during pregonial development. Mitosis is generally not observed in PGCs at extragonadal locations, whereas they are mitotically active once at the gonadal ridges. During gastrulation, PGCs appear to translocate from the epiblast to the hypoblast and during somitogenesis they are found associated with the most peripheral yolk syncitial layer (YSL). From the peripheral YSL they migrate through the median mesoderm into the dorsal mesoderm and then to the dorsal mesentery, where they establish the gonad primordia with mesenchymal cells. Vasa RNA positive cells, the PGCs of the zebrafish conform to these general observations. Interestingly, classical descriptive and experimental data can now be reevaluated using vasa as a molecular marker of the fish germ line. The power of zebrafish genetics together with possibilities of experimental embryology should accelerate research on aspects of vertebrate germ line development such as PGC migration, division and apoptosis, as well as (in) fertility. The present review summarizes some of the classical data on germ line development in fishes in relation to recent data on vasa expression in zebrafish and compares these findings, where appropriate, with those in other model organisms. Special emphasis is placed on vasa gene expression as a potential universal germ line marker and suggestions are made for novel, zebrafish specific approaches to investigate the vertebrate germ line.

Pleiotropic effects of zebrafish protein-tyrosine phosphatase-1B on early embryonic development.

Protein tyrosine phosphorylation is an important mechanism of eukaryotic cell signalling which is regulated by protein-tyrosine kinases and protein-tyrosine phosphatases. Here we report the molecular cloning of the first zebrafish protein-tyrosine phosphatase, zf-PTP-1B, the homologue of human PTP-1B. Zf-PTP-1B was catalytically active and localised to the endoplasmic reticulum, like human PTP-1B. Zf-PTP-1B was maternally expressed in zebrafish embryos, and low ubiquitous expression was detected up to day 7 of development. Microinjection of zf-PTP-1B RNA induced pleiotropic, but reproducible developmental defects. Evaluation of the live embryos at 24 h post fertilisation indicated that zf-PTP-1B induced defects in somite formation. The phenotype was dependent on protein-tyrosine phosphatase activity of zf-PTP-1B, since embryos injected with catalytically inactive zf-PTP-1B-C213S developed normally. Co-injection of wild type and inactive zf-PTP-1B led to a rescue of the zf-PTP-1B-induced phenotype, suggesting that zf-PTP-1B-C213S had dominant negative activity. The zf-PTP-1B-induced phenotype suggests that proper tyrosine phosphorylation of key proteins is essential for early development, most notably somitogenesis.

Immunity to Babesia in mice. II. Cross protection between various Babesia and Plasmodium species and its relevance to the nature of Babesia immunity.

Mice immunized against B. rodhaini by means of a drug-controlled infection were subsequently resistant to infection with B. microti and B. ratti. In the reciprocal experiments the protection against B. rodhaini was less effective. B. rodhaini immunized mice were also considerably protected against P. vinckei infection, whereas protection against P. berghei did not occur. Antibody determinations indicated that the heterologous protection cannot be explained by the occurrence of cross-reacting antibodies. Because of similarity with the non-specific suppression of babesiosis in BCG-infected mice, the same effector mechanism is postulated to explain the infection-induced homologous and heterologous protection. Unlike non-specifically induced protection, the induction of acquired resistance by means of a drug-controlled B. rodhaini infection is thymus-dependent.

Immunity to Babesia in mice. III. The effects of corticosteroids and anti-thymocyte serum on mice immune to Babesia rodhaini.

BALB/c mice, immunized against Babesia rodhaini by an amicarbalide controlled infection, were exposed to selective immunosuppressive treatment with corticosteroids and anti-thymocyte serum (ATS) respectively. Hydrocortisone acetate, 100 mg/kg, given i.p. six times during the three weeks after challenge inoculation caused a rising parasitaemia and high mortality (6/7). Dexamethasone in the drinking water at 20 mg/l or 10 mg/l for 22 days had a similar suppressive effect on the protection against B. rodhaini. Mortality, 100% at the dose rate of 20 mg/l and 50% at 10 mg/l, occurred both in challenged and in carrier animals after the reappearance of parasites in the bloodstream. All the ATS-treated immune mice demonstrated parasitaemia after challenge, although at a lower level than did the corticosteroid treated mice. Seven out of 9 animals died. Corticosteroid-sensitive macrophages together with T-lymphocytes are considered to play an important role in protection against B. rodhaini in specifically induced immunity in mice.

Immunity to Babesia in mice. I. Adoptive transfer of immunity to Babesia rodhaini with immune spleen cells and the effect of irradiation on the protection of immune mice.

Immunisation of Balb/c mice against Babesia rodhaini by an amicarbalide-controlled infection resulted in a solid immunity which lasted for 216 days. With spleen cells of immune mice protection could be transferred both to naive mice pretreated with cyclophosphamide. Treatment of naive mice with cyclophosphamide (300 mg/kg) five days before a lethal B. rodhaini inoculation resulted in over 50% survival. This protective effect of cyclophosphamide is explained by its inhibiting effect on suppressor T-cells. The protection against B. rodhaini challenge infection afforded to immune Balb/c mice was completely resistant to a sublethal irradiation of 400 rad. Since B-lymphocyte function in antibody production is suppressed by this dose, the role of antibodies in the effector phase of the immunity appears to be of minor if any importance. A considerable degree of protection was still preserved after irradiation of immune animals with 875 rad. Sensitivity to this irradiation dose of all immunocompetent cells except macrophages and a small fraction of T-lymphocytes indicates the involvement of these cell types in the effector phase of the specific immunity. Highly radioresistant macrophages are therefore considered to play the major role but T-lymphocytes are also required for complete protection.

Cross immunity between strains of Cowdria ruminantium.

Cross immunity tests with strains of Cowdria ruminantium from South Africa, the Sudan, São Tomé and Nigeria failed to demonstrate antigenic differences. The antibiotic ampicillin showed no activity against heartwater.

Quantitative correlation of parasitological and serological techniques for the diagnosis of Trypanosoma congolense infection in cattle.

A comparison was made between serological and parasitological techniques for the diagnosis of bovine trypanosomiasis in Zambia. Overall sero-prevalence rates as determined by IFAT and ELISA were respectively 2.7-fold and 2.9-fold greater then the percentage of samples found positive with the dark ground/phase contrast buffy coat technique (DG). The results obtained by the two serological techniques were found to be closely correlated (94.2%) agreement) and titres obtained by ELISA tended to be slightly higher than those obtained by IFAT. Linear regression analysis of the results obtained by the IFAT and DG techniques revealed a highly significant correlation. This finding would permit the use of only one of the techniques in an epidemiological survey and to extrapolate the results from the regression line.