MBAT: A scalable informatics system for unifying digital atlasing workflows

Background  

Digital atlases provide a common semantic and spatial coordinate system that can be leveraged to compare, contrast, and correlate data from disparate sources. As the quality and amount of biological data continues to advance and grow, searching, referencing, and comparing this data with a researcher's own data is essential. However, the integration process is cumbersome and time-consuming due to misaligned data, implicitly defined associations, and incompatible data sources. This work addressing these challenges by providing a unified and adaptable environment to accelerate the workflow to gather, align, and analyze the data.     

Isolation of lactoperoxidase, lactoferrin, α-lactalbumin, β-lactoglobulin B and β-lactoglobulin A from bovine rennet whey using ion exchange chromatography

A mild and rapid method is described for isolating various milk proteins from bovine rennet whey. β-Lactoglobulin from bovine rennet whey was easily adsorbed on and desorbed from a weak anion exchanger, diethylaminoethyl-Toyopearl. However, α-lactalbumin could not be adsorbed onto the resin. α-Lactalbumin and β-lactoglobulin from rennet whey could also be adsorbed and separated using a strong anion exchanger, quaternary aminoethyl-Toyopearl. The rennet whey was passed through a strong cation exchanger, sulphopropyl-Toyopearl, to separate lactoperoxidase and lactoferrin. α-Lactalbumin and β-lactoglobulin were adsorbed onto quaternary aminoethyl-Toyopearl. α-Lactalbumin was eluted using a linear (0–0.15 M) concentration gradient of NaCl in 0.05 M Tris–HCl buffer (pH 8.5). Subsequently, β-lactoglobulin B and β-lactoglobulin A were eluted from the column with 0.05 M Tris–HCl (pH 6.8), using a linear (0.1–0.25 M) concentration gradient of NaCl. The yields were 1260 mg α-lactalbumin, 1290 mg β-lactoglobulin B and 2280 mg β-lactoglobulin A from 1 l rennet whey.     

Fine structure of early human embryos frozen with 1,2 propanediol

Previous studies by a French group (Fertil Steril 44:645–651, 1985) have shown that two-to eight-cell human embryos can survive slow freeze-thawing with propanediol in a biological freezer. These embryos were assessed for morphological appearance by phase-contrast microscopy. We assessed the structure of 25 frozen-thawed one- to 12-cell embryos, obtained from our in vitro fertilization (IVF) and GIFT programmes, by phase-contrast and electron microscopy, using the same method of cryopreservation. One-fourth of the embryos examined had all cells intact, and more than one-half the embryos had over 50% of their cells well preserved. Some of these embryos had unequal blastomeres and cytoplasmic fragments. Ultrastructural assessment revealed good preservation of fine structure in the intact blastomeres of all embryos and maintenance of cell-to-cell contacts. Most cytoplasmic organelles, cell membranes, and nuclei were well preserved compared to nonfrozen controls. The cells that were cryoinjured showed varying degrees of disorganization of the cell membrane, cytosol, and cellular membranes, including swelling and disruption of the nuclear envelope. Disruption of the zona was somewhat rare. Small cytoplasmic fragments were less prone to cryoinjury than blastomeres. The use of propanediol for embryo cryopreservation seems to be feasible; frozen embryos with more than 50% cells intact have produced 10 pregnancies after embryo transfer (Fertil Steril 46:268–272, 1986). Replacement of 17 frozen embryos in seven patients has resulted in a twin pregnancy in Singapore. However, the effects of freezing on the mitotic spindles of embryonic cells need to be investigated further.     

Effect of Phosphate on the Corrosion of Carbon Steel and on the Composition of Corrosion Products in Two-Stage Continuous Cultures of Desulfovibrio desulfuricans

A field isolate of Desulfovibrio desulfuricans was grown in defined medium in a two-stage continuous culture apparatus with different concentrations of phosphate in the feed medium. The first state (V1) was operated as a conventional chemostat (D = 0.045 h⁻¹) that was limited in energy source (lactate) or phosphate. The second stage (V2) received effluent from V1 but no additional nutrients, and contained a healthy population of transiently starved or resting cells. An increase in the concentration of phosphate in the medium fed to V1 resulted in increased corrosion rates of carbon steel in both V1 and V2. Despite the more rapid corrosion observed in growing cultures relative to that in resting cultures, corrosion products that were isolated under strictly anaerobic conditions from the two culture modes had similar bulk compositions which varied with the phosphate content of the medium. Crystalline mackinawite (Fe₉S₈), vivianite [Fe₃(PO₄)₂ · 8H₂O], and goethite [FeO(OH)] were detected in amounts which varied with the culture conditions. Chemical analyses indicated that the S in the corrosion product was almost exclusively in the form of sulfides, while the P was present both as phosphate and as unidentified components, possibly reduced P species. Some differential localization of S and P was observed in intact corrosion products. Cells from lactate-limited, but not from phosphate-limited, cultures contained intracellular granules that were enriched in P and Fe. The results are discussed in terms of several proposed mechanisms of microbiologically influenced corrosion.     

Genetic analysis of human B cell hybridomas expressing a cross-reactive idiotype

We have examined the genetic basis for the expression of a human cross-reactive idiotype (CRI) commonly found on monoclonal IgM rheumatoid factors. The CRI was identified with a monoclonal antibody (17.109) and has been localized previously to the kappa-variable region. By using the human lymphoblastoid cell line WI-L2-729-HF2, and mononuclear cells from several sources, a panel of hybridomas was generated that produced 17.109 CRI-positive Ig. A recently cloned human germ-line V kappa III gene, Humkv305, served as a probe to identify genes which were rearranged and expressed in 17.109 CRI-positive and -negative hybridomas. This probe, when hybridized to human genomic DNA under stringent conditions, identified only two to five germ-line bands. In 10 separate 17.109 CRI-positive hybridoma clones, an additional rearranged V kappa band was identified. The probe did not anneal to rearranged V kappa bands in hybridoma clones that produced kappa-chains lacking the CRI. RNA dot-blot studies provided evidence for expression of genes hybridizing to the Humkv305 probe. The results indicate that the 17.109 CRI is a serologic marker for a single V kappa gene, or a small family of closely related V kappa genes, which is identified by the Humkv305 probe.     

Linkage studies with chromosome 17 DNA markers in 45 neurofibromatosis 1 families

A locus for von Recklinghausen neurofibromatosis (NF1) has recently been mapped near the chromosome 17 centromere. We have extended these linkage studies by genotyping 45 NF1 families with three DNA probes known to be linked to the chromosome 17 centromeric region. Of 34 families informative for NF1 and at least one of the three probes, 28 families show no recombinants with the disease gene. These data provide additional support for genetic homogeneity of NF1 and for a primary NF1 locus linked to the chromosome 17 centromere. Among the informative families were 7 families with apparent new NF1 mutations. Our data suggest that these mutations are probably at the chromosome 17 NF1 locus.     

Beta 2 (Oriental) human liver alcohol dehydrogenases do not exhibit subunit interaction: oxidation of cyclohexanol by homo- and heterodimers

The steady-state kinetics of isozymes of human liver alcohol dehydrogenase (ADH) containing the beta 2 (Oriental) subunit were investigated in order to confirm the supposition [Fong, W.P., & Keung, W. M. (1987) Biochemistry (preceding paper in this issue)] that the subunits of such heterodimeric ADHs act independently and noncooperatively. The ADH isozymes alpha beta 2, beta 2 beta 2, beta 2 gamma 1, and beta 2 gamma 2 as well as gamma 1 gamma 1 were purified by chromatography on DEAE-cellulose, 4-[3-[N-(6-aminocaproyl)amino]propyl]pyrazole--Sepharose, and CM-cellulose. Their kinetics were studied at pH 9.0 with cyclohexanol since this substrate permits maximal differentiation between activities of the heterodimeric subunits. Oxidation of cyclohexanol by the homodimers beta 2 beta 2 and gamma 1 gamma 1 follows conventional Michaelis-Menten kinetics. The values of Km and kcat determined for beta 2 beta 2 and gamma 1 gamma 1 are 0.11 M and 260 min-1 and 79 microM and 45 min-1, respectively, indicating that beta 2 beta 2, like the previously studied beta 1 beta 1, has an unusually low binding affinity for cyclohexanol compared to that of the ADH isozymes formed by the combination of alpha, gamma 1, and gamma 2 chains. Cyclohexanol oxidation by the heterodimers alpha beta 2, beta 2 gamma 1, and beta 2 gamma 2 follows biphasic kinetics which can be fully accounted for by the individual subunits, one exhibiting a high and the other a low substrate-binding affinity. Eadie-Hofstee plots resolve the biphasic kinetics into two linear components, each of which yields a set of kinetic parameters.(ABSTRACT TRUNCATED AT 250 WORDS)     

The influence of higher temperature on dengue-2 virus infected C6/36 mosquito cell line

Dengue-2 virus infection of C6/36 cells was studied at 28 and 37 degrees C. In infected cells maintained at 28 degrees C, syncytial development was seen on day 4 postinfection, whereas at 37 degrees C, extensive syncytial development was seen by 32 h. Extracellular virus titre was found to correlate with the cytopathic changes. Nine Dengue-2 virus specified proteins were observed in polyacrylamide analyses of cytoplasmic extracts of C6/36 infected cells. All the proteins were observed, although in varied intensities by 32 h postinoculation at 37 degrees C and only on day 4 postinoculation at 28 degrees C. The GP60 glycoprotein appeared at 32 h postinfection when the cells were maintained at 37 degrees C and became prominent only on day 5 at 28 degrees C. The results revealed that a higher temperature accelerated the onset of cytopathic effects, hastened the development of virus specified proteins, and also enhanced the titre of extracellular infectious virus. The importance of the accumulation of the envelope protein GP60 for the development of CPE was indicated.     

Nutrition and muscle potassium: differential effect in rat slow and fast muscles

The effects of malnutrition on intracellular K+ activity, (alpha K)i, and membrane potential, Em, were measured by means of double-barrelled K+-selective microlectrodes in the soleus and gastrocnemius muscles of the rat. (alpha K)i and Em were measured in vivo in normal anaesthetized animals and in rats subjected to one of two diet restrictions: a 2-day fast or a long-term hypocaloric diet. In the soleus muscle, (alpha K)i fell by similar amounts in both 2-day fasted and long-term hypocalorically fed rats, while Em depolarized significantly only in hypocalorically fed rats. In the gastrocnemius muscle, neither the 2-day fast nor the hypocaloric diet affected (alpha K)i or Em. It is suggested that the selective loss of K+ from the soleus muscle may be related to its activity pattern.     

Evidence that epidermal growth factor is present in swiftlet's (Collocalia) nest

1. An epidermal growth factor (EGF)-like activity was detected and partially purified from swiftlet's nest extract. 2. The partially purified EGF-like activity was able to (a) generate competitive binding curves parallel to the standard curves in radioreceptor assay and (b) stimulate thymidine incorporation in quiescent culture of 3T3 fibroblasts and the latter activity can be suppressed by mouse EGF antibody. 3. Partial characterization of the EGF-like activity in terms of pI, molecular weight and its behavior on gel filtration column suggest that it bears similar physical properties to the EGFs isolated from the mouse and the shrew.