Microbial-induced MnO2 precipitation in a carbonate coastal aquifer.

A study was carried out to identify biogeochemical reactions along a transect of a coastal dolomitic aquifer. In this transect, the physicochemical parameters of the groundwater as well as the microbial composition of samples taken at different depths and salinities were measured. Many of the dissolved ions measured in the groundwater follow a pattern that reflects the distribution of the water masses (fresh, interface and salt) in the aquifer, while others such as Ca and Mg ions deviate from this trend by identifying the zones of maximum dissolution of the carbonate matrix. The concentrations of minor ions, such as Fe and Mn, also follow a singular pattern, with maximum concentrations in the reducing zones of the aquifer and lower values in the oxidizing zones. Precipitates of Mn oxides along with other metals, such as Fe, Ba, Zn and Ni, were observed in the saline zone displaying oxidizing conditions close to the coastline, where a continuous core was recovered. This zone, which is located below the freshwater-seawater mixing zone and features percentages of seawater higher than 80 %, is characterized by the presence of Marinobacter as the predominant genus. These bacteria are also related to the formation of Mn-rich polymetallic oxides in other contexts such as the ocean floor (Wang et al., 2012; Cao et al., 2021). All in all, a biogeochemical reaction model is proposed that describes the formation of these oxides in areas close to the discharge zone of coastal aquifers. To do this, it has been necessary to integrate the results obtained from geochemical, hydrogeological and microbiological information.

Feeding behavior and social interactions of the Argentine ant Linepithema humile change with sucrose concentration.

Liquid sugar baits are well accepted by the Argentine ant Linepithema humile and are suitable for the chemical control of this invasive species. We evaluated how sugar concentrations affect the foraging behavior of L. humile individuals. We quantified feeding variables for individual foragers (ingested load, feeding time and solution intake rate) when feeding on sucrose solutions of different concentrations, as well as post-feeding interactions with nestmates. Solutions of intermediate sucrose concentrations (10-30%) were the most consumed and had the highest intake rates, whereas solutions of high sucrose concentrations (60 and 70%) resulted in extended feeding times, low intake rates and ants having smaller crop loads. In terms of post-feeding interactions, individuals fed solutions of intermediate sucrose concentrations (20%) had the highest probability of conducting trophallaxis and the smallest latency to drop exposure (i.e. lowest time delay). Trophallaxis duration increased with increasing sucrose concentrations. Behavioral motor displays, including contacts with head jerking and walking with a gaster waggle, were lowest for individuals that ingested the more dilute sucrose solution (5%). These behaviors have been previously suggested to act as a communication channel for the activation and/or recruitment of nestmates. We show here that sucrose concentration affects feeding dynamics and modulates decision making related to individual behavior and social interactions of foragers. Our results indicate that intermediate sucrose concentrations (ca. 20%), appear to be most appropriate for toxic baits because they promote rapid foraging cycles, a high crop load per individual, and a high degree of stimulation for recruitment.

A novel methane sensor based on porous SnO2 nanorods: room temperature to high temperature detection.

We report for the first time a novel room temperature methane (CH(4)) sensor fabricated using porous tin oxide (SnO(2)) nanorods as the sensing material. The porous SnO(2) nanorods were synthesized by using multiwall carbon nanotubes (MWCNTs) as templates. Current versus time curves were obtained demonstrating the room temperature sensing capabilities of the sensor system when exposed to 0.25% CH(4) in air. The sensor also exhibited a wide temperature range for different concentrations of CH(4) (25-500 °C), making it useful in harsh environments as well.

Surface oxidation study of single wall carbon nanotubes.

Functionalization of single wall carbon nanotubes (SWCNTs) is desirable to enhance their ability to be incorporated into polymers and enhance their bonding with the matrix. One approach to carbon nanotube functionalization is by oxidation via a strong oxidizing agent or refluxing in strong acids. However, this approach can damage the nanotubes, leading to the introduction of defects and/or shorter nanotubes. Such damage can adversely affect the mechanical, thermal, and electrical properties. A more benign approach to nanotube functionalization has been developed involving photo-oxidation. Chemical analysis by XPS revealed that the oxygen content of the photo-oxidized SWCNTs was 11.3 at.% compared to 6.7 at.% for SWCNTs oxidized by acid treatment. The photo-oxidized SWCNTs produced by this method can be used directly in various polymer matrices or can be further modified by additional chemical reactions.

A new scanning electron microscopy approach to image aerogels at the nanoscale.

A new scanning electron microscopy (SEM) technique to image poor electrically conductive aerogels is presented. The process can be performed by non-expert SEM users. We showed that negative charging effects on aerogels can be minimized significantly by inserting dry nitrogen gas close to the region of interest. The process involves the local recombination of accumulated negative charges with positive ions generated from ionization processes. This new technique made possible the acquisition of images of aerogels with pores down to approximately 3 nm in diameter using a positively biased Everhart-Thornley (ET) detector.

[Dermatophytoses due to anthropophilic fungi in Cadiz, Spain, between 1997 and 2008]. / Dermatofitosis por hongos antropofílicos en Cádiz (1997-2008).

BACKGROUND AND OBJECTIVES: Cutaneous fungal infections are a major public health problem. The distribution of the dermatophytoses varies between countries and geographical areas. The aim of this study was to determine the incidence, epidemiology, etiology, and clinical course of the dermatophytoses caused by anthropophilic fungi in Cadiz, Spain, over the past 12 years. MATERIAL AND METHODS: The study, conducted between 1997 and 2008, included 2,235 samples from lesions of the skin, hair, and nails of 2,220 patients with a clinical suspicion of mycosis. Samples were examined by microscopy using potassium hydroxide and were cultured on mycological media. The dermatophytes were identified by their macroscopic and microscopic characteristics. RESULTS: Cultures were positive in 283 cases (12.7%). Anthropophilic dermatophytes (53.3%) were more common than zoophilic (41.3%) and geophilic (5.3%) dermatophytes. Trichophyton rubrum (38.2%) was the predominant pathogen isolated, followed by Microsporum canis (22.3%) and Trichophyton mentagrophytes (15.5%). Five other species of anthropophilic fungi were identified: Trichophyton tonsurans (5.6%), Trichophyton violaceum (4.9%), Epidermophyton floccosum (2.8%), Trichophyton soudanense (1.0%), and Trichophyton schoenleinii (0.7%). Infections caused by the anthropophilic fungi included tinea unguium (29.1%), tinea corporis (25.8%), tinea pedis (19.2%), tinea cruris (11.9%), tinea capitis (5.3%), and tinea faciei (3.3%). CONCLUSIONS: The principal fungus responsible for dermatomycosis in Cadiz was T. rubrum, and its incidence has been rising since 2000. The prevalence of other anthropophilic fungi, such as T. tonsurans and T. violaceum, has increased, though this is not directly related to immigration. E. floccosum, T. soudanense, and T. schoenleinii are isolated occasionally.

Dermatofitosis por hongos antropofílicos en Cádiz (1997–2008) / Dermatophytoses due to anthropophilic fungi in Cadiz, Spain, between 1997 and 2008

Introducción y objetivos: Las infecciones cutáneas producidas por hongos constituyen un importante problema de salud pública. La distribución de las dermatofitosis varía en diferentes países y áreas geográficas. El objetivo de este estudio ha sido determinar la epidemiología, etiología y evolución de las dermatofitosis por hongos antropofílicos en Cádiz durante los últimos 12 años. Material y métodos: El estudio se realizó de 1997 – 2008 sobre 2.235 muestras de lesiones de piel, pelo y uñas de 2.220 pacientes con sospecha clínica de micosis. Las muestras fueron analizadas mediante examen microscópico con hidróxido potásico y cultivo en medios micológicos. Los dermatofitos se identificaron de acuerdo con las características macroscópicas y microscópicas. Resultados: El cultivo fue positivo en 283 muestras (12,7%). Los dermatofitos antropofílicos (53,3%) predominaron sobre los zoofílicos (41,3%) y geofílicos (5,3%). Trichophyton rubrum (38,2%) fue el patógeno más frecuente, seguido de Microsporum canis (22,3%) y Trichophyton mentagrophytes (15,5%). Se identificaron otras cinco especies de hongos antropofílicos: T. tonsurans (5,6%), T. violaceum (4,9%), Epidermophyton floccosum (2,8%), T. soudanense (1,0%) y T. schoenleinii (0,7%). Las infecciones por hongos antropofílicos fueron onicomicosis (29,1%), tiña corporal (25,8%), tiña del pie (19,2%), tiña crural (11,9%), tiña del cuero cabelludo (5,3%) y tiña facial (3,3%). Conclusiones: El principal responsable de dermatofitosis en Cádiz es Trichophyton rubrum. Su incidencia es ascendente desde el año 2000. Otros hongos antropofílicos como T. tonsurans y T. violaceum son cada vez más prevalentes, aunque no están directamente relacionados con la inmigración. Epidermophyton floccosum, T. soudanense y T. schoenleinii se aíslan ocasionalmente (AU)

Background and objectives: Cutaneous fungal infections are a major public health problem. The distribution of the dermatophytoses varies between countries and geographical areas. The aim of this study was to determine the incidence, epidemiology, etiology, and clinical course of the dermatophytoses caused by anthropophilic fungi in Cadiz, Spain, over the past 12 years. Material and methods: The study, conducted between 1997 and 2008, included 2,235 samples from lesions of the skin, hair, and nails of 2,220 patients with a clinical suspicion of mycosis. Samples were examined by microscopy using potassium hydroxide and were cultured on mycological media. The dermatophytes were identified by their macroscopic and microscopic characteristics. Results: Cultures were positive in 283 cases (12.7%). Anthropophilic dermatophytes (53.3%) were more common than zoophilic (41.3%) and geophilic (5.3%) dermatophytes. Trichophyton rubrum (38.2%) was the predominant pathogen isolated, followed by Microsporum canis (22.3%) and Trichophyton mentagrophytes (15.5%). Five other species of anthropophilic fungi were identified: Trichophyton tonsurans (5.6%), Trichophyton violaceum (4.9%), Epidermophyton floccosum (2.8%), Trichophyton soudanense (1.0%), and Trichophyton schoenleinii (0.7%). Infections caused by the anthropophilic fungi included tinea unguium (29.1%), tinea corporis (25.8%), tinea pedis (19.2%), tinea cruris (11.9%), tinea capitis (5.3%), and tinea faciei (3.3%). Conclusions: The principal fungus responsible for dermatomycosis in Cadiz was T. rubrum, and its incidence has been rising since 2000. The prevalence of other anthropophilic fungi, such as T. tonsurans and T. violaceum, has increased, though this is not directly related to immigration. E. floccosum, T. soudanense, and T. schoenleinii are isolated occasionally (AU)

Peritonitis fúngica en diálisis peritoneal continua ambulatoria: descripción de 10 casos / No disponible

Antecedentes: La peritonitis fúngica es una complicación infrecuente pero grave en pacientes en diálisis peritoneal continua ambulatoria (DPCA). Métodos: Durante un período de 10 años (1999-2008), de un total de 175 pacientes con insuficiencia renal crónica en tratamiento con DPCA, estudiamos retrospectivamente 10 casos de peritonitis fúngica, analizando los factores predisponentes, aspectos clínicos, agentes etiológicos y tratamiento. El diagnóstico se estableció por la presencia de efluente peritoneal turbio con recuento superior a 100 leucocitos/µl y aislamiento de hongos en el cultivo microbiológico. Resultados: La peritonitis fúngica representó un 3,6% del total de peritonitis. Nueve pacientes tenían historia de peritonitis bacteriana previa y todos habían recibido antibioterapia. Otros hallazgos destacables fueron: edad superior a70 años (50%) y diabetes mellitus (40%). El examen microscópico del líquido peritoneal fue de utilidad para sospechar la infección en 6 pacientes (60%). Los agentes responsables de peritonitis fueron: Candida parapsilosis (4), C. albicans(2), C. tropicalis(1), C. glabrata (1), C. famata (1) y Fusarium oxysporum(1). Los antifúngicos utilizados en el tratamiento fueron: fluconazol intraperitoneal y oral, vorizonazol intravenoso y oral y anfotericina B intravenosa. A consecuencia de la infección fúngica, 8 pacientes fueron transferidos a hemodiálisis. Un paciente murió antes de ser diagnosticado y otros tres durante el episodio de peritonitis. Conclusiones: Los pacientes con episodios de peritonitis bacteriana previos y tratamiento antibiótico presentaron un mayor riesgo de desarrollar peritonitis fúngica. C. parapsilosis fue el patógeno más frecuente. El tratamiento antifúngico junto con la retirada del catéter peritoneal fue eficaz en el 60% de los pacientes (AU)

Background: Fungal peritonitis is a rare but serious complication in patients undergoing continuous ambulatory peritoneal dialysis(CAPD). Methods: During a ten-year period (1999-2008), from a total of 175 patients with chronic renal failure undergoing CAPD, we retrospectively studied 10 cases of fungal peritonitis analyzing the predisposing factors, clinical aspects, etiological agents and treatment. Diagnosis was based on elevated CAPD effluent count(>100/µl) and isolation of fungi on culture. Results: Fungalperitonitis represented 3.6% of all peritonitis episodes. Nine patients had a history of previous bacterial peritonitis and all of them were under antibiotic therapy. Other common findings were: age higher than 70 years old (50%) and diabetes mellitus(40%). Direct microscopic examination of the peritoneal fluid was useful for the suspicion of fungal infection in six patients(60%). The responsible agents for peritonitis were: Candidaparapsilosis (4), C. albicans (2), C. tropicalis (1), C. glabrata (1), C.famata (1) and Fusarium oxysporum (1). Intraperitoneal and oralfluconazole, intravenous and oral voriconazole and intravenousamphotericin B were the antifungal agents used in the treatment. As a result of fungal infection, eight patients were transferred to hemodialysis. One patient died before the diagnosis and three other during the episode of peritonitis. Conclusions: Patients with previous bacterial peritonitis and antibiotic treatment were at greater risk of developing fungal peritonitis. C. parapsilosis was the most common pathogen. For the successful management of fungal peritonitis besides the antifungal therapy, peritoneal catheter removal was necessary in60% of patients (AU)

[Fungal peritonitis in ambulatory continuous peritoneal dialysis: description of 10 cases]. / Peritonitis fúngica en diálisis peritoneal continua ambulatoria: descripción de 10 casos.

BACKGROUND: Fungal peritonitis is a rare but serious complication in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). METHODS: During a ten-year period (1999-2008), from a total of 175 patients with chronic renal failure undergoing CAPD, we retrospectively studied 10 cases of fungal peritonitis analyzing the predisposing factors, clinical aspects, etiological agents and treatment. Diagnosis was based on elevated CAPD effluent count (>100/microl) and isolation of fungi on culture. RESULTS: Fungal peritonitis represented 3.6% of all peritonitis episodes. Nine patients had a history of previous bacterial peritonitis and all of them were under antibiotic therapy. Other common findings were: age higher than 70 years old (50%) and diabetes mellitus (40%). Direct microscopic examination of the peritoneal fluid was useful for the suspicion of fungal infection in six patients (60%). The responsible agents for peritonitis were: Candida parapsilosis (4), Candida albicans (2), Candida tropicales (1), Candida glabrata (1), Candida famata (1) and Fusarium oxysporum (1). Intraperitoneal and oral fluconazole, intravenous and oral voriconazole and intravenous amphotericin B were the antifungal agents used in the treatment. As a result of fungal infection, eight patients were transferred to hemodialysis. One patient died before the diagnosis and three other during the episode of peritonitis. CONCLUSIONS: Patients with previous bacterial peritonitis and antibiotic treatment were at greater risk of developing fungal peritonitis. Candida parapsilosis was the most common pathogen. For the successful management of fungal peritonitis besides the antifungal therapy, peritoneal catheter removal was necessary in 60% of patients.

Field Emission and Radial Distribution Function Studies of Fractal-like Amorphous Carbon Nanotips.

The short-range order of individual fractal-like amorphous carbon nanotips was investigated by means of energy-filtered electron diffraction in a transmission electron microscope (TEM). The nanostructures were grown in porous silicon substrates in situ within the TEM by the electron beam-induced deposition method. The structure factor S(k) and the reduced radial distribution function G(r) were calculated. From these calculations a bond angle of 124 degrees was obtained which suggests a distorted graphitic structure. Field emission was obtained from individual nanostructures using two micromanipulators with sub-nanometer positioning resolution. A theoretical three-stage model that accounts for the geometry of the nanostructures provides a value for the field enhancement factor close to the one obtained experimentally from the Fowler-Nordheim law.

Nanocrystalline silicon as the light emitting material of a field emission display device.

A nanocrystalline Si-based paste was successfully tested as the light emitting material in a field emission display test device that employed a film of carbon nanofibers as the electron source. Stable emission in the 550-850 nm range was obtained at 16 V µm(-1). This relatively low field required for intense cathodoluminescence (CL) from the PSi paste may lead to longer term reliability of both the electron emitting and the light emitting materials, and to lower power consumption. Here we describe the synthesis, characterization, and analyses of the light emitting nanostructured Si paste and the electron emitting C nanofibers used for building the device, including x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The corresponding spectra and field emission curves are also shown and discussed.

In vivo antitumor activity and host toxicity of methoxymorpholinyl doxorubicin: role of cytochrome P450 3A.

Methoxymorpholinyl doxorubicin (MMDX; PNU 152243) is a promising doxorubicin derivative currently undergoing clinical evaluation. Previous in vitro studies suggested that the compound undergoes hepatic biotransformation by cytochrome P450 (CYP) 3A into a more cytotoxic metabolite(s). The present study examined the role of CYP3A-mediated metabolism in the in vivo antitumor activity and host toxicity of MMDX in the mouse model and investigated the potential for increasing the therapeutic effectiveness of the drug by inducing its hepatic CYP-catalyzed activation. We found that MMDX cytotoxicity for cultured M5076 tumor cells was potentiated 22-fold by preincubating the drug with NADPH-supplemented liver microsomes from untreated C57BL/6 female mice. A greater (50-fold) potentiation of MMDX cytotoxicity was observed after its preincubation with liver microsomes isolated from animals pretreated with the prototypical CYP3A inducer pregnenolone-16alpha-carbonitrile. In contrast, in vivo administration of the selective CYP3A inhibitor troleandomycin (TAO) reduced both potentiation of MMDX cytotoxicity and the rate of CYP3A-catalyzed N-demethylation of erythromycin by isolated liver microsomes (55.5 and 49% reduction, respectively). In vivo antitumor activity experiments revealed that TAO completely suppressed the ability of 90 microg/kg MMDX i.v., a dose close to the LD10, to delay growth of s.c. M5076 tumors in C57BL/6 mice and to prolong survival of DBA/2 mice with disseminated L1210 leukemia. Moreover, TAO administration markedly inhibited the therapeutic efficacy of 90 microg/kg MMDX i.v. in mice bearing experimental M5076 liver metastases; a complete loss of MMDX activity was observed in liver metastases-bearing animals receiving 40 microg/kg MMDX i.v. plus TAO. However, pregnenolone-16alpha-carbonitrile pretreatment failed to enhance MMDX activity in mice bearing either s.c. M5076 tumors or experimental M5076 liver metastases. Additional experiments carried out in healthy C57BL/6 mice showed that TAO markedly inhibited MMDX-induced myelosuppression and protected the animals against lethal doses of MMDX. Taken together, these findings demonstrate that an active metabolite(s) of MMDX synthesized via CYP3A contributes significantly to its in vivo antitumor activity and host toxicity.

Toxicity of fatty acid 18:5n3 from Gymnodinium cf. mikimotoi: II. Intracellular pH and K+ uptake in isolated trout hepatocytes.

Effects of octadecapentaenoic acid 18:5n3 and other related polyunsaturated fatty acids present in gymnodinium cf. mikimotoi were tested in isolated trout hepatocytes. These exotoxins decreased intracellular pH followed by a slow recovery to initial value and alkalinization of acidic compartments, suggesting an inhibition of vacuolar H(+)-ATPases. Moreover, addition of 18:5n3 to the extracellular medium induced a decrease of K+ uptake into hepatocytes as a result of Na,K-ATPase inhibition. However, high concentrations (10(-5)-10(-3) M) are necessary to induce these effects.

Toxicity of fatty acid 18:5n3 from Gymnodinium cf. mikimotoi: I. Morphological and biochemical aspects on Dicentrarchus labrax gills and intestine.

We present evidence for the toxic effects of fatty acid 18:5n3 (octadecapentaenoic acid) in the gills and intestine of the sea bass Dicentrarchus labrax. Light microscopic observation of gills showed strong mucus production and alteration of ionocytes. The Mg- and Na,K-ATPase activities were inhibited, with IC50 values of 10(-3) and 1.6 x 10(-4) M, respectively. Results are discussed in relation to osmoregulation.

The antitumor efficacy of cytotoxic drugs is potentiated by treatment with PNU 145156E, a growth-factor-complexing molecule.

PNU 145156E (formerly FCE 26644) is a noncytotoxic molecule whose antitumor activity is exerted through the formation of a reversible complex with growth/angiogenic factors, thus inhibiting their induction of angiogenesis. We studied in vitro and in vivo the activity of PNU145156E in combination with the four cytotoxic drugs doxorubicin, cyclophosphamide, methoxymorpholinyldoxorubicin (MMDX, FCE 23762, PNU152243), and 9-aminocamptothecin against M5076 murine reticulosarcoma. In vitro, PNU 145156E did not modify the cytotoxicity of the four drugs or the cell-cycle block induced by doxorubicin. In vivo, at the optimal dose of each compound, the antitumor activity was significantly increased in all combinations, with no associated increase in general toxicity being observed. In healthy mice treated with cyclophosphamide or doxorubicin the association with PNU 145156E did not enhance the myelotoxic effect induced by the two cytotoxics. These results indicate that two drugs affecting solid tumor growth through two different mechanisms-growth factor blockage and cell proliferation can be combined, resulting in increased antitumor efficacy with no additive toxicity.

Antiangiogenic, antitumoural and antimetastatic effects of two distamycin A derivatives with anti-HIV-1 Tat activity in a Kaposi's sarcoma-like murine model.

The antiangiogenic, antitumoural and antimetastatic effects of two novel sulphonic derivatives of distamycin A, PNU145156E and PNU153429, were studied in a Kaposi's sarcoma-like tumour model obtained by injecting nude mice with cells releasing extracellular HIV-Tat protein, derived from a tumour which developed in a BK virus/tat transgenic mouse. Both PNU145156E and PNU153429 were administered intraperitoneally every fourth day for three weeks at doses of 100 or 50 mg/kg of body weight respectively, starting one day after injecting the tumour cells. Both drugs delayed tumour growth in nude mice, preventing neovascularization induced by the Tat protein. PNU153429 also significantly reduced the number and size of spontaneous tumour metastases. Both effects on tumour growth and metastases were augmented by treating simultaneously nude mice with 7.5 mg/kg of body weight of minocycline given per os daily for four weeks starting four days after injecting the tumour cells. Neither acute nor chronic toxic side-effects were observed during the life span of treated nude mice. Due to their antiangiogenic and anti-Tat effects, these drugs are promising for the treatment of Kaposi's sarcoma in AIDS patients.

Characterization of the effects of two polysulfonated distamycin A derivatives, PNU145156E and PNU153429, on HIV type 1 Tat protein.

We examined whether two sulfonated distamycin A derivatives, PNU145156E and PNU153529, inhibit the trans-activating and angiogenic effects of HIV-1 Tat protein. The study was carried out by analyzing the activity of the two drugs on: (1) extracellular and intracellular Tat protein, introduced into HL3T1 cells containing an integrated HIV-1 LTR/CAT plasmid; (2) binding of Tat to 3H-labeled heparin and to 14C-labeled PNU145156E; and (3) the angiogenic response induced in vivo by culture medium conditioned by T53c14 cells, which release extracellular Tat. PNU145156E and PNU153429 interacted with extracellular Tat in the culture medium and physically bound the Tat protein, most likely sequestering it in the extracellular space. As a consequence, the two drugs inhibited trans-activation of the HIV-1 LTR on addition of the free Tat protein to HL3T1 cells. However, the two compounds inhibited the activity of intracellular Tat when they were introduced into the cells by lipofection. In vivo experiments showed that the two drugs blocked the neoangiogenesis induced by Tat released in the conditioned medium of T53c14 cells. Owing to the critical role of intracellular and extracellular Tat in HIV-1 replication, these drugs show promise as a means to control the progression of HIV-1 infection as well as the neoplastic and angiogenic effects induced by Tat in the course of AIDS.

Effects of copper on gill structure and transport function in the rainbow trout, Oncorhynchus mykiss.

Effects of copper were studied in freshwater adapted rainbow trout using the perfused head preparation. In its monovalent chemical form, copper at millimolar concentrations had no significant effects on Na+ and water transport. By contrast, the divalent form produced an increase in gill perfusion pressure, a significant reduction in Na+ influx and water fluxes and reversed Na+ net flux. Observations by light microscopy showed important cell damage (oedema, mucus production, cellular desquamation). By electron microscopy there was smoothing of apical membranes, swelling of the tubular system and destruction of mitochondria. The Na, K-ATPase activity was totally suppressed and residual ATPase activity largely inhibited by 1 mM Cu2+. There was inhibition of the Na,K-ATPase activity with an IC50 of approximately 10 microM of total copper (free and bound cupric fractions). As active sodium transport is located on the secondary lamellae, our results show that its entry mechanism is inhibited at that level by cupric ions only. Results are discussed in relation to hydromineral balance of the trout.

Antitumor activity of FCE 26644 a new growth-factor complexing molecule.

FCE 26644, or 7,7'-(carbonyl-bis[imino-N-methyl-4, 2 pyrrole carbonyl-imino(N-methyl-4,2-pyrrole)carbonyl-imino])-bis-(1,3- naphthalene)disulfonic acid, belongs to the newly synthesized class of sulfonated derivatives of distamycin A. FCE 26644 is a noncytotoxic molecule capable of inhibiting the binding of basic fibreblast growth factor (bFGF), platelet-derived growth factor (PDGF beta) and interleukin 1 (IL-7) to their receptors and to block bFGF-induced vascularization in vivo as well as neovascularization in the chorioallantoic membrane. FCE 26644 and suramin, a compound possessing the same terminal half-life (t1/2) in mice and, presumably, the same mode of action, inhibit the growth of solid murine tumors, M5076 reticulosarcoma, and MXT and S180 fibrosarcoma and are inactive against B16F10 melanoma. The activity of FCE 26644 was constantly observed at nontoxic doses, at variance with suramin. FCE 26644 was also found to maintain activity against M5076 resistant to cyclophosphamide and to be equally active against UV 2237 and UV 2237/ADR fibrosarcoma.