CONTINUUM: A Self-Engineering Creature-Culture

An interdisciplinary design research collaborative led by Alisa Andrasek, CONTINUUM emerged from a series of design research seminars at Columbia University's graduate school of architecture. Working collaboratively with Robert Aish, Andresek's workshops explored the potential of the new Bentley Systems' GenerativeComponents design software, which at the time was in beta testing. CONTINUUM was formed to extend the possibilities of such collaborations and has expanded its network, occupying an interesting and unique territory of intersecting interests between academia, corporate practice and the companies that create design tools. Traditionally understood as antagonistic, commercial and progressive interests and intentions find common ground in their shared need for research into advanced design software that will enable the retooling of architectural practice. Here, Pia Ednie-Brown, with illustrations by Alisa Andrasek, examines the unique ways in which CONTINUUM enfolds diverse professional and academic practices. Copyright © 2006 John Wiley & Sons, Ltd.     

Calcium‐phosphate and parathyroid intradialytic profiles: A potential aid for tailoring the dialysate calcium content of patients on different hemodialysis schedules

Severe hyperparathyroidism is a challenge on hemodialysis. The definition of dialysate calcium (Ca) is a pending issue with renewed importance in cases of individualized dialysis schedules and of portable home dialysis machines with low‐flow dialysate. Direct measurement of calcium mass transfer is complex and is imprecisely reflected by differences in start‐to‐end of dialysis Ca levels. The study was performed in a dialysis unit dedicated to home hemodialysis and to critical patients with wide use of daily and tailored schedules. The Ca‐phosphate (P)‐parathyroid hormone (PTH) profile includes creatinine, urea, total and ionized Ca, albumin, sodium, potassium, P, PTH levels at start, mid, and end of dialysis. “Severe” secondary hyperparathyroidism was defined as PTH > 300 pg/mL for ≥3 months. Four schedules were tested: conventional dialysis (polysulfone dialyzer 1.8–2.1 m²), with dialysate Ca 1.5 or 1.75 mmol/L, NxStage (Ca 1.5 mmol/L), and NxStage plus intradialytic Ca infusion. Dosages of vitamin D, calcium, phosphate binders, and Ca mimetic agents were adjusted monthly. Eighty Ca‐P‐PTH profiles were collected in 12 patients. Serum phosphate was efficiently reduced by all techniques. No differences in start‐to‐end PTH and Ca levels on dialysis were observed in patients with PTH levels < 300 pg/mL. Conversely, Ca levels in “severe” secondary hyperparathyroid patients significantly increased and PTH decreased during dialysis on all schedules except on Nxstage (P < 0.05). Our data support the need for tailored dialysate Ca content, even on “low‐flow” daily home dialysis, in “severe” secondary hyperparathyroid patients in order to increase the therapeutic potentials of the new dialysis techniques.     

Determination of insulin-like growth factor-1 and bovine insulin in raw milk and its casein and whey fractions after microfiltration and ultrafiltration

Insulin-like growth-factor 1 (IGF-1) and insulin were analysed from bovine milk during microfiltration (MF) and ultrafiltration (UF) processes using immunochemical methods. IGF-1 was found in the MF retentate and in the UF retentate. A very small fraction of IGF-1 was in the UF permeate. The results indicated that IGF-1 was present in milk as a complex molecule or bound to milk proteins. Insulin showed similar behaviour, but more insulin was found in the MF retentate than in the UF retentate. No insulin was found in the UF permeate. There were no differences in IGF-1 or insulin distribution between pasteurised or non-pasteurised milk. The stability of bovine insulin to heat treatments was also determined. The molecule was stable during pasteurisation at 65 and 72 °C, but lost some of its immunochemical activity at 90 and 135 °C.     

Influence of different smoking techniques on contamination by polycyclic aromatic hydrocarbons in traditional smoked Mozzarella di Bufala Campana

The levels of six polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene and three other PAH were determined in smoked Mozzarella di Bufala Campana. Different smoking techniques were compared to evaluate the risk associated with consumption of these cheeses. Although no maximum limits are set for PAHs in cheese, the levels found in some samples constitute a health risk. In fact, using corrugated cardboard, high levels were detected in the whole product or in the outer part. Also, the use of traditional materials involves the accumulation of PAHs in the outer part, but in the total product concentrations are significantly lower. No contamination was found using liquid smoke.     

Antimicrobial and antioxidative enrichment of oak (Quercus robur) bark by rotation planar extraction using ExtraChrom

The multifunctional ExtraChrom instrument was used in the extraction of antimicrobial and radical scavenging components from oak (Quercus robur L.) bark. Milled and sieved oak bark was extracted with 80% (v/v) methanol solution in water on the ExtraChrom instrument using step-gradient in the preparative separation. Extracts were tested using agar diffusion method on Staphylococcus aureus, Enterobacter aerogenes and Candida albicans. Some extracts showed moderate bactericidal, fungicidal, bacteriostatic and fungistatic activity. The composition related to activity of the fractions and extracts was screened simultaneously by thin-layer chromatography (TLC) detected by UV and by spraying the plate with radical scavenging reagent 1,1-diphenyl-2-picrylhydrazyl (DPPH) to detect antioxidant activity. Thus, we could demonstrate the antiradical and antimicrobial activity of oak beneficial in the storage of wine against the oxidation and human microbial exposure.     

Direct binding of a redox protein for single-molecule electron transfer measurements

An electron transfer protein is engineered with two thiol groups introduced at different positions in the molecular structure to allow robust binding to two gold electrodes. Atomic force microscopy and scanning tunneling microscopy single-molecule studies show that the engineered proteins: (1) bind to a gold electrode in defined orientation dictated by the thiol-pair utilised, and (2) have a higher conductance than the wild-type proteins indicating a more efficient electron transmission due to the strong gold-thiol contacts.     

High-level production of human type I collagen in the yeast Pichia pastoris.

Four human genes, two of them encoding the proalpha1 and proalpha2 chains of type I procollagen and two of them the two types of subunit of prolyl 4-hydroxylase (4-PH), were integrated into the genome of Pichia pastoris. The proalpha1 and proalpha2 chains expressed formed type I procollagen molecules with the correct 2:1 chain ratio, and the 4-PH subunits formed an active enzyme tetramer that fully hydroxylated the proalpha chains. Chains lacking their N but not C propeptides formed pCcollagen molecules with the 2:1 chain ratio and, surprisingly, the expression levels of pCcollagen were 1.5-3-fold relative to those of procollagen. Both types of molecule could be converted by pepsin treatment to collagen molecules that formed native-type fibrils in vitro. The expression levels obtained for the pCcollagen using only single copies of each of the four genes and a 2 l fermenter ranged up to 0.5 g/l, indicating that it should be possible to optimize this system for high-level production of recombinant human type I collagen for numerous medical applications.