The role of prickle proteins in vertebrate development and pathology.

Prickle is an evolutionarily conserved family of proteins exclusively associated with planar cell polarity (PCP) signalling. This signalling pathway provides directional and positional cues to eukaryotic cells along the plane of an epithelial sheet, orthogonal to both apicobasal and left-right axes. Through studies in the fruit fly Drosophila, we have learned that PCP signalling is manifested by the spatial segregation of two protein complexes, namely Prickle/Vangl and Frizzled/Dishevelled. While Vangl, Frizzled, and Dishevelled proteins have been extensively studied, Prickle has been largely neglected. This is likely because its role in vertebrate development and pathologies is still being explored and is not yet fully understood. The current review aims to address this gap by summarizing our current knowledge on vertebrate Prickle proteins and to cover their broad versatility. Accumulating evidence suggests that Prickle is involved in many developmental events, contributes to homeostasis, and can cause diseases when its expression and signalling properties are deregulated. This review highlights the importance of Prickle in vertebrate development, discusses the implications of Prickle-dependent signalling in pathology, and points out the blind spots or potential links regarding Prickle, which could be studied further.

Coordinated labio-lingual asymmetries in dental and bone development create a symmetrical acrodont dentition.

Organs throughout the body develop both asymmetrically and symmetrically. Here, we assess how symmetrical teeth in reptiles can be created from asymmetrical tooth germs. Teeth of lepidosaurian reptiles are mostly anchored to the jaw bones by pleurodont ankylosis, where the tooth is held in place on the labial side only. Pleurodont teeth are characterized by significantly asymmetrical development of the labial and lingual sides of the cervical loop, which later leads to uneven deposition of hard tissue. On the other hand, acrodont teeth found in lizards of the Acrodonta clade (i.e. agamas, chameleons) are symmetrically ankylosed to the jaw bone. Here, we have focused on the formation of the symmetrical acrodont dentition of the veiled chameleon (Chamaeleo calyptratus). Intriguingly, our results revealed distinct asymmetries in morphology of the labial and lingual sides of the cervical loop during early developmental stages, both at the gross and ultrastructural level, with specific patterns of cell proliferation and stem cell marker expression. Asymmetrical expression of ST14 was also observed, with a positive domain on the lingual side of the cervical loop overlapping with the SOX2 domain. In contrast, micro-CT analysis of hard tissues revealed that deposition of dentin and enamel was largely symmetrical at the mineralization stage, highlighting the difference between cervical loop morphology during early development and differentiation of odontoblasts throughout later odontogenesis. In conclusion, the early asymmetrical development of the enamel organ seems to be a plesiomorphic character for all squamate reptiles, while symmetrical and precisely orchestrated deposition of hard tissue during tooth formation in acrodont dentitions probably represents a novelty in the Acrodonta clade.

Prospective study of fungaemia in a single cancer institution over a 10-y period: aetiology, risk factors, consumption of antifungals and outcome in 140 patients.

Over a 10-y period (1989-99) we prospectively evaluated all patients with fungaemia among 16,555 admissions (21,004 blood cultures) at a national cancer referral institution in the Slovak Republic. A prospective protocol was completed on 140 patients with fungaemia, which was then analysed in terms of aetiology, clinical characteristics, potential risk factors and outcome. The most frequently isolated organism was C. albicans, in 75 patients (52.9%), followed by non-albicans Candida spp. in 45 patients (32.1%). Non-Candida spp. yeasts represented 16 episodes in 16 patients (11.4%). Moulds caused 4 episodes in 4 patients (3.6% of all fungaemias) and all were caused by Fusarium spp. Mucositis (p = 0.025), > or = 3 positive blood cultures (p = 0.02), acute leukaemia (p = 0.00001), neutropenia (p = 0.0015), quinolone prophylaxis (p < 0.000005) and breakthrough fungaemia (p = 0.004) during prophylaxis with fluconazole (p = 0.03) and itraconazole (p = 0.005) were significantly more associated with non-Candida than C. albicans spp. Furthermore, attributable mortality was higher in the subgroup of non-Candida than C. albicans spp. (50.0 vs. 18.7%, p < 0.02). The only independent risk factor for inferior outcome was antifungal therapy of < 10 d duration (odds ratio 2.1, 95% confidence interval, p < 0.001). Aetiology, neutropenia and mucositis were not independent risk factors for higher mortality in multivariate analysis; however, they were risk factors for inferior outcome in univariate analysis (p < 0.05-0.005).

Changes in cellular immunity among workers occupationally exposed to styrene in a plastics lamination plant.

BACKGROUND: Styrene is a widely used industrial chemical. Immune and hematological parameters were examined in 29 hand laminators and sprayers exposed to styrene for an average of 14 years and in 19 in-factory unexposed controls. The workers performed hand lamination procedures in a production area with an average area airborne styrene level of 139.5 mg/m(3). Mean concentration of styrene in the blood of exposed workers was 945.7 microg/L and the mean styrene in exhaled air was 38.8 microg/L. METHODS: Parameters of internal and external exposure, immune function assays, immunoglobulins, acute phase reactants and hematology were evaluated in exposed and non-exposed populations. RESULTS: Using multifactorial analysis of variance we found a significant decrease in proliferation of lymphocytes stimulated by Concanavalin A but not by pokeweed mitogen (PWM) in workers occupationally exposed to styrene. Proliferative response to PWM was significantly correlated with the levels of styrene in blood. Phagocytic activity of monocytes, levels of IgG, IgA, IgM, IgE and alpha-2-macroglobulin in serum were indistinguishable in the two groups. The population exposed to styrene had increased levels of C4-component of complement. Levels of C3-component of complement were positively correlated with duration of exposure. A significant elevation in the percentage and number of monocytes and a significantly decreased number of lymphocytes were seen in exposed workers. Styrene concentrations in both blood and exhaled air were associated with decreased percentage of large granular lymphocytes. CONCLUSIONS: These results suggest immune alterations of cell-mediated immune response of T-lymphocytes and imbalance in leucocyte subsets in peripheral blood of workers exposed to styrene.

Prospective study on fungemia in children with cancer: analysis of 35 cases and comparison with 130 fungemias in adults.

The aim of this prospective study on fungemia in children with cancer compared with adults with cancer appearing during the last 10 years in a pediatric hospital and in national cancer institutions was to investigate risk factors, etiology, therapy, complications and outcome. Univariate analysis showed significant differences in 35 children with cancer and fungemia in comparison with 130 cases of fungemias in adults with cancer. It was found that (1) therapy with corticosteroids (40 vs 18.5%, P<0.03), (2) breakthrough fungemia during ketoconazole prophylaxis (20 vs 7.7%, P<0.025), and (3) meningitis as a complication of fungemia (11.4 vs 0.8%, P< 0.001) occurred more frequently in the pediatric subgroup with fungemia. Candida albicans was more common as the causative agent of fungemia among adults (58.5 vs 37.1, P<0.02) than in children. However, mortality was similar in children with cancer and in adults with cancer and fungemia (31.4 vs 23.1%, NS). Comparison of risk factors revealed no differences between adults and children with cancer and fungemia except in etiology, breakthrough fungemia during prophylaxis with ketoconazole, prior therapy with corticosteroids and meningitis as a complication. The outcome was also similar in pediatric and adult cancer patients with fungal bloodstream infection.

Ciprofloxacin in treatment of nosocomial meningitis in neonates and in infants: report of 12 cases and review.

Twelve cases of neonatal and infant nosocomial meningitis treated with intravenous ciprofloxacin in doses of 10 to 60 mg/kg/day are described. Four neonates were 21 to 28 days old and eight infants were 2 to 6 months old. Six presented with Gram-negative meningitis: Escherichia coli (2), Salmonella enteritidis (1), Acinetobacter calcoaceticus (1), two with two organisms, and (H. influenzae plus Staphylococcus epidermidis, Acinetobacter spp. plus S. epidermidis), and six were attributable to Gram-positive cocci (four S. aureus and two Enterococcus faecalis). Ten cases were cured. In two cases, reversible hydrocephalus appeared that responded to intraventricular punctures. In seven children, no neurologic sequellae appeared after a 2- to 4-year follow-up. One neonate had relapse of meningitis 3 months later and was ultimately cured, but developed a sequellae of psychomotoric retardation. Follow-up varied from 27 months to 10 years. Current published case reports from Medline on quinolone use in meningitis in neonates and infants are reviewed.

Documented fungal infections after prophylaxis or therapy with wide spectrum antibiotics: relationship between certain fungal pathogens and particular antimicrobials?

Antibiotics are known to be one of the major risk factors for fungal infection. We investigated whether there was a relationship between particular documented fungal infections and therapeutically or prophylactically administered antimicrobials in 105 patients with fungemia or histologically proven invasive aspergillosis or fusariosis. Out of 105 patients, 82.9% received antimicrobials affecting anaerobic microbial gut flora such as: imipenem, vancomycin, ceftazidime, metronidazole, clindamycin or ampicillin-sulbactam. In addition, 44.5% of patients had received prophylaxis with ofloxacin. 31.5% of Candida albicans fungemias occurred despite empiric therapy with amphotericin B and 21.1% during prophylaxis with azoles. The incidence of C. albicans infections (fungemias) was significantly higher (58.9% vs 33.7%, p<0.04) in patients receiving antibiotics not affecting anaerobic gut flora such as ofloxacin, an aminoglycoside or azithromycin. On the other hand, patients treated with third generation cephalosporins, carbapenems, glycopeptides, and broad spectrum penicillins were more likely to develop proven invasive Aspergillus spp. infection (27.9% vs 5.3%, p<0.001) in comparison to those treated with antimicrobials which preserve anaerobic gut flora.

Investigation of professional nickel exposure in nickel refinery workers.

For assessing the real exposure level of nickel in electrolytical nickel production workers we monitored the following indicators of Ni load. (a) Stationary air sampling of Ni, (b) personal air sampling of Ni, (c) urine Ni excretion determined on group basis, (d) the 4 hours specimen of Ni excretion determined on an individual basis. A tentative limit for Ni in urine, roughly corresponding to the MAC 0.05 mg/m3 was 12 micrograms/l Ni according to (c) and 30 micrograms/l Ni according to (d). The occupational exposure limit for Ni in urine accepted in Czechoslovakia is 30 micrograms/l Ni.

[Intestinal parasitoses in Laos]. / Problematika strevních parazitóz v Laosu.

The authors give an account of the contemporary parasitological position in Laos, based on data from abroad, data provided by the Laos health services and results of the authors' parasitological examinations. Examination of clinical material (in Laos by Willis method and after fixation with SAF by examination of the sediment in the CSR) revealed a high immunity rate of the population with ascaridosis, ancylostomosis, trichuriosis and opisthorchosis and a relatively low prevalence of Protozoan infections.