The combined effects of energy and disturbance on species richness in protist microcosms

The supply of energy, and the frequency of disturbance can both affect species diversity, often, although not always, producing unimodal diversity patterns along an energy or disturbance gradient. However, it has been suggested that diversity is a combined function of both factors, and the dynamic equilibrium model proposed by Huston (1979) is one formalization of this suggestion. This idea has received little direct testing. Here we carry out such a test using protist microcosms, in a factorial manipulation of six levels of energy (quantity of organic resource) and five levels of disturbance (frequency of temperature shock). Species richness responded to both energy supply and disturbance frequency, although not always unimodally. Patterns of response changed over time, and there was some evidence of an interaction between energy and disturbance at two of six time intervals. However, the specific form of this interaction differs from that predicted by the dynamic equilibrium model, and overall, the results provide little support for the model.     

Partial 7q Isochromosome in Bone Marrow Following Treatment of Hodgkin's Disease

We report on a 29-year-old female followed for relapsed Hodgkin's disease. She had been diagnosed with Hodgkin's disease at 20 years of age and had been treated with chemotherapy. She had been in remission for six years when she relapsed, at which time she received chemotherapy for bone marrow transplant (BMT). After failure of BMT, she received additional chemotherapies with growth factors and radiation treatment. A bone marrow biopsy showed moderate hypercellularity with erythroid hyperplasia, but the karyotype had an abnormal clone containing an isochromosome derived from a 7q22 deletion.     

Immunodiagnostic and molecular approaches for the detection of taeniid cestode infections

This article summarizes the most recent advances in techniques and applications for the detection of taeniid cestode-infected persons or animals. In addition, the use of molecular approaches for strain identification and control of parasite transmission is discussed.     

Assessment of selenium bioavailability from naturally produced high-selenium soy foods in selenium-deficient rats

We assessed the bioavailability of selenium (Se) from a protein isolate and tofu (bean curd) prepared from naturally produced high-Se soybeans. The Se concentrations of the soybeans, the protein isolate and tofu were 5.2 ± 0.2, 11.4 ± 0.1 and 7.4 ± 0.1 mg/kg, respectively. Male weanling Sprague–Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet (4.1 μg Se/kg) for 56 days, and then they were replenished with Se for an additional 50 days by feeding them the same diet containing 14, 24 or 30 μg Se/kg from the protein isolate or 13, 23 or 31 μg Se/kg from tofu, respectively. l-Selenomethionine (SeMet) was used as a reference. Selenium bioavailability was determined on the basis of the restoration of Se-dependent enzyme activities and tissue Se concentrations in Se-depleted rats, comparing those responses for the protein isolate and tofu to those for SeMet by using a slope-ratio method. Dietary supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in glutathione peroxidase activities in blood and liver and in thioredoxin reductase activity in liver. Furthermore, supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in the Se concentrations of plasma, liver, muscle and kidneys. These results indicated an overall bioavailability of approximately 101% for Se from the protein isolate and 94% from tofu, relative to SeMet. We conclude that Se from naturally produced high-Se soybeans is highly bioavailable in this model and that high-Se soybeans may be a good dietary source of Se.     

Chloridzellen der Larven von Caenis diminuta WALKER (Ephemeroptera,Caenidae) bei unterschiedlicher Salinität

The larvae of Caenis diminuta WALKER (Ephemeroptera, Caenidae) have coniform chloride cells which are involved in osmoregulation. The number of chloride cells varies according to salinity conditions of the surrounding waters. The larvae from brackish water have less chloride cells than the larvae from fresh water.     

N-terminal sequence analysis of human placental protein 14, purified in high yield from decidual cytosol

Human placental protein 14 (PP14) has been purified in high yield from first trimester decidual cytosol. High-performance liquid chromatography on anion exchange, gel filtration and reverse-phase chromatography were used. The protein obtained is approximately 97% pure with an overall recovery of about 50% from the original tissue extract. The first 24 amino acids of the N-terminal were found to be Met-Asp-Ile-Pro-Gln-Thr-Lys-Gln-Asp-Leu-Glu-Leu-Pro-Lys-Leu-Ala-Gly-Thr-Glu-His - Glu-Met-Ala-Met. PP14 has been characterized in this study to be a dimeric glycoprotein of Mr 60,000, with homologous subunits having an Mr of 28,000.     

Human Amnion Epithelial Cells Induced to Express Functional Cystic Fibrosis Transmembrane Conductance Regulator

Cystic fibrosis, an autosomal recessive disorder caused by a mutation in a gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR), remains a leading cause of childhood respiratory morbidity and mortality. The respiratory consequences of cystic fibrosis include the generation of thick, tenacious mucus that impairs lung clearance, predisposing the individual to repeated and persistent infections, progressive lung damage and shortened lifespan. Currently there is no cure for cystic fibrosis. With this in mind, we investigated the ability of human amnion epithelial cells (hAECs) to express functional CFTR. We found that hAECs formed 3-dimensional structures and expressed the CFTR gene and protein after culture in Small Airway Growth Medium (SAGM). We also observed a polarized CFTR distribution on the membrane of hAECs cultured in SAGM, similar to that observed in polarized airway cells in vivo. Further, hAECs induced to express CFTR possessed functional iodide/chloride (I^−/Cl⁻) ion channels that were inhibited by the CFTR-inhibitor CFTR-172, indicating the presence of functional CFTR ion channels. These data suggest that hAECs may be a promising source for the development of a cellular therapy for cystic fibrosis.     

Compromised proteasome degradation elevates neuronal nitric oxide synthase levels and induces apoptotic cell death

The significance of impairment of proteasome activity in PC12 cells was examined in connection with nitrative/nitrosative stress and apoptotic cell death. Treatment of differentiated PC12 cells with MG132, a proteasome inhibitor, elicited a dose- and time-dependent increase in neuronal nitric oxide synthase (nNOS) protein levels, decreased cell viability, and increased cytotoxicity. Viability and cytotoxicity were ameliorated by L-NAME (a broad NOS inhibitor). Nitric oxide/peroxynitrite formation was increased upon treatment of PC12 cells with MG132 and decreased upon treatment with the combination of MG132 and 7-NI (a specific inhibitor of nNOS). The decreases in cell viability appeared to be effected by an activation of JNK and its effect on mitochondrial Bcl-x_L phosphorylation. These effects are strengthened by the activation of caspase-9 along with increased caspase-3 activity upon treatment of PC12 cells with MG132. These results suggest that impairment of proteasome activity and consequent increases in nNOS levels lead to a nitrative stress that involves the coordinated response of JNK cytosolic signaling and mitochondrion-driven apoptotic pathways.     

Thiophilic paramagnetic particles as a batch separation medium for the purification of antibodies from various source materials

A preparation of thiophilic agarose-based paramagnetic particles (T-Gel) has been developed with physical characteristics (particle size and particle density) that facilitate its use as a batch separation medium suitable for the large-scale purification and isolation of immunoglobulins. The medium was used to extract immunoglobulins from a wide range of starting materials, including sera, ascites fluid, tissue culture medium, and whole blood. None of these starting materials required pretreatment such as clarification by centrifugation or filtration prior to antibody extraction. The antibody purity obtained using T-Gel compared well with that obtained using protein A agarose column chromatography. Yields were approximately 30 mg of immunoglobulins per milliliter of T-Gel, and little was required in the way of specialist equipment. The method is uncomplicated and involves a roll mix extraction overnight, followed by magnetic separation to facilitate supernatant removal and subsequent washing of the particles. Elution of bound antibodies was carried out at neutral pH to yield a concentration of immunoglobulins that was approximately 7 mg/ml. The method was found to be applicable to antibody purification from the blood serum of seven different mammalian species and for all immunoglobulin classes.