Histoplasma capsulatum peritonitis associated with continuous ambulatory peritoneal dialysis

This paper reports a case of infection byHistoplasma capsulatum apparently restricted to the peritoneum in a woman submitted to continuous ambulatory peritoneal dialysis. Diagnosis was established by culture of dialysis fluid and peritoneal nodule and by histopathologic examination.     

Chemical composition and larvicidal activity of essential oils of three Artemisia species

Aedes aegypti L. (Diptera: Culicidae) is a vector for serious diseases in tropical regions. This pest is mainly controlled by commercial larvicides but the application of such products has led to environmental problems. Essential oils (EO) have been consistently reported as molecules with insecticidal activity and can be used to produce more environmentally friendly larvicides in the control of A. aegypti. In this study, the larvicidal effect of essential oils (EO) from the leaves of three Artemisia species was evaluated against A. aegypti. The oils were obtained from steam distillation and their chemical composition was determined by gas chromatography–mass spectrometry. The EO of Artemisia camphorata was the most active in the screening bioassay and presented LC₅₀ and LC₉₅ of 64.95 and 74.18 μg ml⁻¹, respectively. In addition, we found that germacrene D-4-ol was the constituent responsible for the toxicity of this EO. Artemisia camphorata EO and its major constituent, germacrene D-4-ol, are promising for the development of natural larvicides against A. aegypti.     

Enhanced transformation of tomato co-cultivated with Agrobacterium tumefaciens C58C1Rifr::pGSFR1161 in the presence of acetosyringone

Summary Explants of tomato (Lycopersicon esculentum Mill cv. Ailsa Craig) were co-cultivated with Agrobacterium tumefaciens C58C1Rif^r::pGSFR1161 in the presence of 20 (M acetosyringone). Transformed root clones were selected on kanamycin medium and the presence of the nptII gene in the plant DNA confirmed by the polymerase chain reaction. Root clones derived from acetosyringone treatment grew more vigorously in the presence of kanamycin and synthesized a greater amount of NPT-II enzyme. The conclusion is that acetosyringone treatment enhances the transformation process, possibly by stimulating multiple insertions of the T-DNA into the host genome.Abbreviations AS acetosyringone - CTAB hexadecyltrimethylammonium bromide - EDTA ethylenediaminetetraacetic acid - ELISA enzyme-linked immunosorbant assay - MS Murashige and Skoog (1962) medium - PCR polymerase chain reaction     

Human pluripotent stem cell-derived extracellular vesicles: From now to the future

Extracellular vesicles (EVs) are nanometric particles that enclose cell-derived bioactive molecules in a lipid bilayer and serve as intercellular communication tools. Accordingly, in various biological contexts, EVs are reported to engage in immune modulation, senescence, and cell proliferation and differentiation. Therefore, EVs could be key elements for potential off-the-shelf cell-free therapy. Little has been studied regarding EVs derived from human pluripotent stem cells (hPSC-EVs), even though hPSCs offer good opportunities for induction of tissue regeneration and unlimited proliferative ability. In this review article, we provide an overview of studies using hPSC-EVs, focusing on identifying the conditions in which the cells are cultivated for the isolation of EVs, how they are characterized, and applications already demonstrated. The topics reported in this article highlight the incipient status of the studies in the field and the significance of hPSC-EVs’ prospective applications as PSC-derived cell-free therapy products.     

Manipulating photosynthesis

The levels of individual photosynthetic proteins can be independently decreased by theAgrobacterium-mediated transformation of plants with antisens RNA constructs. Protocols for the introduction of such constructs intoAgrobacterium, theAgrobacterium-mediated transformation of tobacco leaf disks, and the screening and analysis of the transgenic plants produced are described.     

Cutaneous zygomycosis caused byAbsidia corymbifera in a leukemic patient

A case of cutaneous zygomycosis caused byAbsidia coryabifera in a leukemic patient submitted to chemotherapy is reported. The lesion was located on the little finger of the right hand and probably resulted from a latent osteomyelitis. It progressed to form extensive necrotic area. No systemic infection was detected and the lesion did not appear to be associated with any trauma.     

Dynamic properties of cockroach cercal “threadlike” hair sensilla

Input-output (I-O) relationships were studied in cercal “thread-hair” sensilla (THS) on Periplaneta americana L. by recording from individual axons of THS while displacing the corresponding hair with a galvanometric device. Sinusoidal analysis was attempted and pulse- and ramplike displacements were then tested. The effects of stimulus orientation were also investigated. THS were spontaneously active and purely phasic and did not respond to sustained displacements. With small sinusoidal displacements (<30°) they behaved as a linear, secondorder lead system sensitive to velocity. With larger amplitudes, however, they exhibited prominent nonlinear features with minimal consequences of displacements at the extremes. Responses to other waveforms indicated secondorder response components. THS were directionally sensitive. Phasic behavior and the nonlinearities may be due to mechanical properties at the base of the hair. The spike-firing threshold may also contribute. Resting activity appears to be due to neuronal factors since it was not abolished by preventing hair movements. Transducer operations were simulated in a digital computer.     

The second polar lobe of theSabellaria cementarium embryo plays an inhibitory role in apical tuft formation

Summary The embryo ofSabellaria cementarium (Polychaeta) forms a polar lobe at each of the first two cleavage divisions which becomes absorbed into one of the blastomeres at the end of the division. Lobe removal experiments show that the polar lobe preceding first cleavage is necessary for the development of the apical tuft and the posttrochal region of the trochophore larva. The polar lobe preceding second cleavage is smaller than the first polar lobe and is necessary only for post-trochal region development. In blastomere isolation experiments, isolates containing the C but not the D blastomere form apical tufts. Isolates containing the D but not the C blastomere do not form apical tufts. When the polar lobe preceding second cleavage is removed and the C and D blastomeres are separated and raised in isolation, each can form an apical tuft. When the second cleavage is equalized with sodium dodecyl sulfate (SDS) such that both the C and the D blastomeres receive second polar lobe material, no apical tuft is formed. These results suggest that apical tuft determinants are distributed to both the C and D blastomeres at second cleavage but that the second polar lobe contains an inhibitor for apical tuft formation which is shunted to the D blastomere after the completion of second cleavage.