Visual short-term memory for overtly attended objects during infancy.

We investigated limitations in young infants' visual short-term memory (VSTM). We used a one-shot change detection task to ask whether 4- and 8.5-month-old infants (N = 59) automatically encode fixated items in VSTM. Our task included trials that consisted of the following sequence: first a brief (500 ms) presentation with a sample array of two items, next a brief (300 ms) delay period with a blank screen, and finally a test array (2,000 ms) identical to the sample array except that the color of one of the two items is changed. In Experiment 1, we induced infants to fixate one item by rotating it during the sample (the other item remained stationary). In Experiment 2, none of the items rotated. In both experiments, 4-month-old infants looked equally at the fixated item when it did and did not change color, providing no evidence that they encoded in VSTM the fixated item. In contrast, 8.5-month-old infants in Experiment 1 preferred the fixated item when it changed color from sample to test. Thus, 4-month-old infants do not appear to automatically encode fixated items in VSTM.

Structural basis for regulation of a CBASS-CRISPR-Cas defense island by a transmembrane anti-σ factor and its ECF σ partner.

How CRISPR-Cas and cyclic oligonucleotide-based antiphage signaling systems (CBASS) are coordinately deployed against invaders remains unclear. We show that a locus containing two CBASS and one type III-B CRISPR-Cas system, regulated by the transmembrane anti-σ DdvA and its cognate extracytoplasmic function (ECF) σ DdvS, can defend Myxococcus xanthus against a phage. Cryo-electron microscopy reveals DdvA-DdvS pairs assemble as arrow-shaped transmembrane dimers. Each DdvA periplasmic domain adopts a separase/craspase-type tetratricopeptide repeat (TPR)-caspase HetF-associated with TPR (TPR-CHAT) architecture with an incomplete His-Cys active site, lacking three α-helices conserved among CHAT domains. Each active site faces the dimer interface, raising the possibility that signal-induced caspase-like DdvA autoproteolysis in trans precedes RseP-mediated intramembrane proteolysis and DdvS release. Nuclear magnetic resonance reveals a DdvA cytoplasmic CHCC-type zinc-bound three-helix bundle that binds to DdvS σ2 and σ4 domains, undergoing σ4-induced helix extension to trap DdvS. Altogether, we provide structural-mechanistic insights into membrane anti-σ-ECF σ regulation of an antiviral CBASS-CRISPR-Cas defense island.

Genome sequences of Mx1, the first Myxococcus phage isolated, and Mx4, a generalized transducing myxophage.

Myxococcus xanthus is the best-studied member of the phylum Myxococcota, but the bacteriophages infecting it and their characterization remain limited. Here, we present complete genomes of Mx1, the first Myxococcus phage isolated, and of an Mx4 derivative widely used for generalized transduction, both unclassified Caudoviricetes with long, contractile tails.

CarF mediates signaling by singlet oxygen, generated via photoexcited protoporphyrin IX, in Myxococcus xanthus light-induced carotenogenesis.

Blue light triggers carotenogenesis in the nonphototrophic bacterium Myxococcus xanthus by inducing inactivation of an anti-σ factor, CarR, and the consequent liberation of the cognate extracytoplasmic function (ECF) σ factor, CarQ. CarF, the protein implicated earliest in the response to light, does not resemble any known photoreceptor. It interacts physically with CarR and is required for its light-driven inactivation, but the mechanism is unknown. Blue-light sensing in M. xanthus has been attributed to the heme precursor protoporphyrin IX (PPIX), which can generate the highly reactive singlet oxygen species ((1)O(2)) by energy transfer to oxygen. However, (1)O(2) involvement in M. xanthus light-induced carotenogenesis remains to be established. Here, we present genetic evidence of the involvement of PPIX as well as (1)O(2) in light-induced carotenogenesis in M. xanthus and of how these are linked to CarF in the signal transduction pathway. Response to light was examined in carF-bearing and carF-deficient M. xanthus strains lacking endogenous PPIX due to deletion of hemB or accumulating PPIX due to deletion of hemH (hemB and hemH are early- and late-acting heme biosynthesis genes, respectively). This demonstrated that light induction of the CarQ-dependent promoter, P(QRS), correlated directly with cellular PPIX levels. Furthermore, we show that P(QRS) activation is triggered by (1)O(2) and is inhibited by exogenously supplied hemin and that CarF is essential for the action of (1)O(2). Thus, our findings indicate that blue light interaction with PPIX generates (1)O(2), which must be transmitted via CarF to trigger the transcriptional response underlying light-induced carotenogenesis in M. xanthus.

Determination of the Pharmacokinetics and Pharmacodynamics of Isoniazid, Rifampicin, Pyrazinamide and Ethambutol in a Cross-Over Cynomolgus Macaque Model of Mycobacterium tuberculosis Infection.

Innovative cross-over study designs were explored in non-human primate (NHP) studies to determine the value of this approach for the evaluation of drug efficacy against tuberculosis (TB). Firstly, the pharmacokinetics (PK) of each of the drugs Isoniazid (H), Rifampicin (R), Pyrazinamide (Z) and Ethambutol (E), that are standardly used for the treatment of tuberculosis, was established in the blood of macaques after oral dosing as a monotherapy or in combination. Two studies were conducted to evaluate the pharmacokinetics and pharmacodynamics of different drug combinations using cross-over designs. The first employed a balanced, three-period Pigeon design with an extra period; this ensured that treatment by period interactions and carry-over could be detected comparing the treatments HR, HZ and HRZ using H37Rv as the challenge strain of Mycobacterium tuberculosis (M. tb). Although the design accounted for considerable variability between animals, the three regimens evaluated could not be distinguished using any of the alternative endpoints assessed. However, the degree of pathology achieved using H37Rv in the model during this study was less than expected. Based on these findings, a second experiment using a classical AB/BA design comparing HE with HRZ was conducted using the M. tb Erdman strain. More extensive pathology was observed, and differences in computerized tomography (CT) scores and bacteriology counts in the lungs were detected, although due to the small group sizes, clearer differences were not distinguished. Type 1 T helper (Th1) cell response profiles were characterized using the IFN-γ ELISPOT assay and revealed differences between drug treatments that corresponded to decreases in disease burden. Therefore, the studies performed support the utility of the NHP model for the determination of PK/PD of TB drugs, although further work is required to optimize the use of cross-over study designs.

Phase I clinical and pharmacokinetic study of plitidepsin as a 1-hour weekly intravenous infusion in patients with advanced solid tumors.

PURPOSE: Plitidepsin, given as a 1-hour weekly i.v. infusion for 3 consecutive weeks during a 4-week treatment cycle, was investigated in patients with solid tumors to determine the maximum tolerated dose and the recommended dose (RD) using this administration schedule. EXPERIMENTAL DESIGN: Consecutive cohorts of patients with metastatic solid tumors or non-Hodgkin's lymphomas were to be treated at escalating doses of plitidepsin in a conventional phase I study including pharmacokinetic analyses of plitidepsin in plasma, whole blood, and blood cell pellets. RESULTS: Forty-nine patients with solid tumors were enrolled, and 48 were treated with plitidepsin (doses from 0.133 to 3.6 mg/m2/week). Dose-limiting toxicities (defining 3.6 mg/m2/week as the maximum tolerated dose) included myalgia, increased creatine phosphokinase levels, and sustained grade 3/4 increases of hepatic enzyme levels. The RD was established at 3.2 mg/m2/week. The most common toxicities were fatigue, vomiting/nausea, anorexia, injection site reaction, and pain, mostly of mild or moderate severity. Muscular toxicity manifested by mild-moderate myalgia, weakness, and/or creatine phosphokinase elevations occurred in approximately 25% of patients and seemed to be dose related. Transient transaminase elevations were frequent but achieved grade 3 or 4 in only approximately 10% of patients. Plitidepsin lacked significant hematologic toxicity. No complete or partial tumor responses were observed; however, five patients had disease stabilization (including one patient with medullary thyroid carcinoma with an unconfirmed partial response and one patient with renal carcinoma with major tumor shrinkage in lung metastases). Pharmacokinetic results for the RD indicated a long plasma half-life give value (16.8 +/- 7.7 hour) and a high volume of distribution value (525.2 +/- 219.3 L). CONCLUSIONS: The recommended dose for plitidepsin given as a weekly 1-hour schedule was 3.2 mg/m2/week. Muscular and liver toxicity were dose limiting at 3.6 mg/m2/week. Additional evaluation of this dose dense schedule is warranted.

A phase I clinical and pharmacokinetic study (LIPOTEC - GP PHARM/DOXO 01) of a new liposomal doxorubicin given as 3-week schedule in patients with solid tumors.

As a dose-finding phase I study of a new liposomal formulation of doxorubicin (LipD), patients (n = 39; median age: 60 years; range, 41-75; median ECOG performance status, 1; range, 0-2) with refractory cancer had a starting dose of LipD administered at 30 mg/m(2) as a 1-hour intravenous infusion. Cycle duration was 21 days. At the recommended dose (RD), patients received a first cycle of nonliposomal doxorubicin (non-LipD) to evaluate intrapatient pharmacokinetic differences between non-LipD and LipD. The most frequent diagnosis was head and neck tumor (7 patients). Tolerance and safety of dose levels of 30, 40, 50, 60, 70, 80, and 90 mg/m(2) were evaluated. A total of 131 cycles were administered (median per patient, 3; range, 1-6). Of the 39 patients, 8 completed the planned six cycles. Febrile neutropenia was dose limiting and defined the toxic dose of LipD as 70 mg/m(2). Other significant toxicities included asthenia (G2: 31%; G3: 8%), neutropenia (G3: 35%; G4: 29%), thrombopenia (G3: 15%; G4: 2%), anemia (G1-G2: 67%; G3-G4: 5%), mucositis (G1-G2: 32%, G3: 4%), and acute allergic reactions (G1-G2: 36%). Comparison of pharmacokinetic profiles of non-LipD and LipD showed that higher exposure was achieved with LipD. Stable disease was observed in 14 patients. We conclude that the LipD regimen, given as a 1-hour infusion every 3 weeks, is well tolerated and has a favorable pharmacokinetic profile. The recommended dose is 70 mg/m(2) with prophylactic antihistamines and corticoids to preempt allergic reaction.

The lift team's importance to a successful safe patient handling program.

Nurses continue to experience injuries related to patient handling. These injuries are costly to hospitals in both direct and indirect costs and intangible costs such as staff morale. The need for hospitals to establish safe patient handling programs is growing and is now mandated by legislation in several states. The authors describe the development, implementation, and 6-year outcomes of a lift team that is part of successful safe patient handling program.

A phase I clinical and pharmacokinetic study of paclitaxel and docetaxel given in combination in patients with solid tumours.

The aim of this study was to determine the safety and feasibility profile of paclitaxel (PTX) and docetaxel (DTX) in combination and the pharmacokinetic and pharmacodynamic interaction between these two drugs in two different alternated sequences of administration. The starting dose was PTX (100 mg/m(2)) as a 3-h IV infusion followed by DTX (50 mg/m(2)) as 1-h IV infusion or the alternative sequence in every other patient. The sequence was alternated in the second course in each patient treated. Cycle duration was 21 days. Twenty patients received 103 cycles of treatment through three dose levels. Febrile neutropenia and grade 4 neutropenia lasting longer than 7 days were dose-limiting and defined the toxic dose of DTX (50 mg/m(2)) and PTX (135 mg/m(2)) in patients with prior treatment and the recommended dose in patients without prior treatment. Non-hematological toxicities included asthenia, neuropathy, arthralgia/myalgia and stomatitis. Pharmacokinetics of DTX were significantly affected by the sequence. Nadir ANC was more profound when DTX was administered first (P=0.022). There were one complete response and six partial responses, giving an overall response rate of 35%. DTX (50 mg/m(2)) followed by PTX (135 mg/m(2)) can be administered safely and it is an active regimen. The pharmacokinetics of PTX are not influenced by DTX but DTX pharmacokinetics depend on the sequence of administration, which influences its haematological toxicity profile.

The high-mobility group A-type protein CarD of the bacterium Myxococcus xanthus as a transcription factor for several distinct vegetative genes.

CarD is the only reported prokaryotic protein showing structural and functional features typical of eukaryotic high-mobility group A transcription factors. In prokaryotes, proteins similar to CarD appear to be confined primarily to myxobacteria. In Myxococcus xanthus, CarD has been previously shown to act as a positive element in two different regulatory networks: one for light-induced synthesis of carotenoids and the other for starvation-induced fruiting body formation. We have now tested the effect of a loss-of-function mutation in the carD gene (carD1) on the expression of a random collection of lacZ-tagged genes, which are normally expressed in the dark during vegetative growth in rich medium. Our results indicate that CarD plays a significant role in the transcriptional regulation of various indicated genes. The carD1 mutation downregulates some genes and upregulates others. Also reported here is the isolation of several mutations that suppress the strong effect of carD1 on the expression of a particular vegetative gene. One of them (sud-2) also suppresses the effect of carD1 on other vegetative genes and on fruiting-body formation. Thus, CarD and the sud-2 gene product appear to participate in a single mechanism, which underlies various apparently diverse regulatory phenomena ascribed to CarD.

Os caminhos da pesquisa psicanalítica: da epistemologia ao método / The psychoanalytic research path: from epistemology to method

A reflexão sobre a pesquisa em psicanálise se concentra em geral: (a) num embasamento epistemológico no qual o conceito de verdade esteja diretamente ligado à teoria do inconsciente; (b) num debate entre a pesquisa psicanalítica e os diferentes modelos de pesquisa científica, no qual as teorias em psicanálise podem ser colocadas em questão quanto ao seu método. O presente estudo propõe, em linhas gerais, a discussão sobre a construção de conceitos em psicanálise e, por consequência, seu estatuto epistemológico. Nesse sentido, voltamos às origens da teoria que surge no final do século XIX, com Sigmund Freud, a fim de questionar o contexto histórico de construção científica e os possíveis modelos de ciência de sua época. Na sequência abordaremos a questão a partir da proposta lacaniana do inconsciente estruturado como uma linguagem que só poderia ser abordado a partir de seus efeitos (sonhos, atos falhos, sintomas)

The reflections regarding the psychoanalysis research generally focus on: (a) an epistemological basis, on which the concept of truth is directly connected to the theory of the unconscious; (b) a debate between psychoanalytical research and different models of scientific research, in which the psychoanalysis' theories can be put in question regarding their methods. The present study proposes, in general, a discussion about the construction of psychoanalytic concepts and, consequently, its epistemological status. In this sense, we return to the origins of the theory, developed in the late nineteenth century, by Sigmund Freud, in order to question the historical context of scientific construction and the possible models of science available at the time. Following, we will discuss the issue based on the Lacanian proposal of the unconscious structured as a language, which could only be approached from its effects (dreams, Freudian slip, symptoms)

Poly(ADP-ribose) polymerase-1 modulates interferon-gamma-inducible protein (IP)-10 expression in murine embryonic fibroblasts by stabilizing IP-10 mRNA.

Poly(ADP-ribose) polymerase-1 (Parp-1) is a nuclear enzyme that uses NAD(+) as a substrate to catalyze the addition of ADP-ribose polymers on a variety of nuclear proteins, modifying transiently their biological functions. Parp-1 has been involved in transcription regulation of many genes involved in the inflammatory response including cytokines and chemokines. Accordingly, genetic deletion of Parp-1 (Parp-1(-/-)) or pharmacological blockade of Parp-1 activity in mice results in a defective inflammatory immune response which confers an advantage in different pathophysiological conditions associated with inflammation. In addition to the transcriptional control, increasing mRNA stability, mainly through the mitogen-activated protein kinase p38 (p38(MAPK)) might be an important mechanism for the tight regulation in the expression of several chemokines such as IP-10. Here we demonstrate that Parp-1 deficiency in embryonic fibroblasts results in diminished IFN-gamma-induced IP-10 expression despite normal STAT1 activation and IP-10 promoter activity. Therefore, we have analyzed the involvement of Parp-1 in IP-10 mRNA stability. Parp-1 deficient cells showed a decreased half-life of IFN-gamma-induced IP-10 transcripts associated with a defect in p38(MAPK) activation. Our results demonstrate that Parp-1 can regulate inflammatory gene expression by increasing mRNA stability, via modulating a proper p38(MAPK) signalling pathway.

An anti-antisigma factor in the response of the bacterium Myxococcus xanthus to blue light.

Cells of the Gram-negative bacterium Myxococcus xanthus respond to blue light by producing carotenoids, pigments that play a protective role against the oxidative effects of light. Blue light triggers a network of regulatory actions that lead to the transcriptional activation of the structural genes for carotenoid synthesis. The product of carF, similar to a family of proteins of unknown function called Kua, is an early regulator of this process. Previous genetic data indicate that CarF participates in the light-dependent inactivation of the antisigma factor CarR. In the dark, CarR sequesters the ECF-sigma factor CarQ to the membrane, thereby preventing the activation of the structural genes for carotenoid synthesis. Using a bacterial two-hybrid system, we show here that both CarF and CarQ physically interact with CarR. These results, together with the finding that CarF is located at the membrane, support the hypothesis that CarF acts as an anti-antisigma factor. Comparison of CarF with other Kua proteins shows a remarkable conservation of a number of histidine residues. The effects on CarF function of several histidine to alanine substitutions and of the truncation of specific CarF domains are also reported here.

Epiteliomas basocelulares de localización infrecuente / Basal cell carcinomas: unusual sites

Estudiamos una población de 36.000 pacientes pertenecientes al Policlínico PAMI I de la ciudad de Rosario durante un período de tiempo comprendido entre el 1 de enero de 1980 al 31 de diciembre de 1999. El estudio fue retrospectivo con el análisis de los datos registrados en las historia clínicas (HC), teniendo en cuenta la localización anatómica del tumor, así como las características clínicas e histopatológicas de los mismos. Describimos aquellos epiteliomas basocelulares (EBC) de localización infrecuente (AU)

Epiteliomas basocelulares de localización infrecuente / Basal cell carcinomas: unusual sites

Estudiamos una población de 36.000 pacientes pertenecientes al Policlínico PAMI I de la ciudad de Rosario durante un período de tiempo comprendido entre el 1 de enero de 1980 al 31 de diciembre de 1999. El estudio fue retrospectivo con el análisis de los datos registrados en las historia clínicas (HC), teniendo en cuenta la localización anatómica del tumor, así como las características clínicas e histopatológicas de los mismos. Describimos aquellos epiteliomas basocelulares (EBC) de localización infrecuente

Granuloma facial: nuestra experiencia / Granuloma faciale: our experience

Presentamos dos pacientes diagnosticados con esta afección para una población fija de 30.000 afiliados y durante un período de 21 años. El primero es un hombre de 72 años con una lesión numular localizada en nariz, de años de evolución. La segunda es una paciente de 70 años con una placa eritematoviolácea localizada en mejilla de 7 años de evolución. Los estudios histopatológicos confirman los diagnósticos. Se les instauraron a ambos pacientes tratamientos con corticoides locales con buena respuesta

Granuloma facial: nuestra experiencia / Granuloma faciale: our experience

Presentamos dos pacientes diagnosticados con esta afección para una población fija de 30.000 afiliados y durante un período de 21 años. El primero es un hombre de 72 años con una lesión numular localizada en nariz, de años de evolución. La segunda es una paciente de 70 años con una placa eritematoviolácea localizada en mejilla de 7 años de evolución. Los estudios histopatológicos confirman los diagnósticos. Se les instauraron a ambos pacientes tratamientos con corticoides locales con buena respuesta (AU)