N-glycans of recombinant human interferon-gamma change during batch culture of chinese hamster ovary cells

A recombinant Chinese hamster ovary (CHO) cell line making human interfron-gamma (IFN-gamma) was grown in 12-L stirred tank fermentors in three batch fermentations under conditions of constant temperature, pH, and dissolved oxygen tension. In addition to cell growth, metabolite, and productivity data, a detailed analysis of the carbohydrate structures attached to each glycosylation site of IFN-gamma was achieved using matrix-assisted laser desorption mass spectrometry (MALDI-MS) in combination with exoglycosidase array sequencing. Complex biantennary oligosaccharides (particularly Gal(2)GlcNAc(4)Man(3) which was core alephl-6 fucosylated at Asn(25) but not at Asng(97)) were most prevalent at both glycosylation sites. However, considerable microheterogeneity arising from the presence of triantennary and truncated glycan structures was also observed. The proportion of the dominant core glycan structure (Gal(2)GlcNAc(4)Man(3) +/- Fuc(1)) decreased by 15-26% during batch culture, with increases in the proportion of oligomannose and truncated glycans over the same time period. Prolonged culture resulting from an extended lag phase led to further accumulation of oligomannose and truncated structures, reaching up to 52% of total glycans attached to Asng(97) by 240 h of culture. The implications of these glycosylation changes for optimizing the time for harvesting cell cultures, and for the clearance of recombinant therapeutic products in vivo are discussed. (c) 1995 John Wiley & Sons, Inc.     

A broadly active viral inhibitor in human and animal organ extracts and body fluids

To help assess the possibility that a newly described viral inhibitor from cell cultures might play a natural defensive role in vivo, its distribution and concentration in human and animal organ extracts and body fluids were investigated. The concentration of the inhibitor was high in human liver, heart muscle, splenic extracts, and human serum and milk. The inhibitor in the body was indistinguishable from a previously described inhibitor produced in cell cultures that was characterized by broad antiviral activity, lack of target cell species specificity, lack of induction of stable antiviral activity in cells, rapid reversibility of antiviral action, prevention of virus attachment, and stability at 100 degrees C. Sixteen virus plaque reduction units of the inhibitor diminished the yield of poliovirus in vitro by more than 1000-fold. Additional evidence that contact-blocking viral inhibitor (CVI) inhibits vaccinia virus attachment to cells is presented. A role for the inhibitor in natural defense against viral infections is possible.     

Serum testosterone, agonistic behavior, and dominance in inbred strains of mice

Social situations in which male mice establish dominant/subordinate relationships were utilized in an attempt to correlate circulating testosterone (T) titer with agonistic behavior. Two long-term (several months) and two short-term (3- and 5-day) situations in which dominance was verified by severity of body scarring or individual aggression scores indicated no consistent correlation of dominance with serum T levels.     

Familial Down's syndrome.

A family is reported in which the same mother conceived two children with trisomy 21. The pregnancy with the second affected child was interrupted after diagnostic amniocentesis. Maternal chromosome analysis was normal. This family and those previously reported suggest that there is an increased recurrence risk of trisomy 21 after the birth of an affected individual, possibly caused by a genetic tendency for non-disjunction. After the birth of a child with Down's syndrome, amniocentesis and chromosome analysis of cultured amniotic fluid cells is indicated in each further pregnancy, irrespective of maternal age.     

Biomass production in mass cultures of marine phytoplankton at varying temperatures

Natural populations of marine phytoplankton obtained from a large outdoor pond were grown on waste water-sea water mixtures in laboratory continuous cultures in the temperature range 5–33 °C. Virtually all of the influent inorganic nitrogen (14.0 mg l^?1) was assimilated at every temperature tested. There was, however, a distinct change in dominant species with temperature: below 19.8 °C Phaeodactylum tricornutum was dominant, at 27 °C Nilzschia sp. was the main species, and as the temperature increased above 27 °C a blue-green alga, Oscillatoria sp., became increasingly dominant. There is some indication that the excellent growth of P. tricornutum below 10 °C was related to a dramatic increase in the nutrient content per cell as the temperature decreased. Thus at low temperatures reduced division rates are compensated for by increased nutrient uptake rates. It follows that there is a transfer of phytoplankton protein from numerous small cells at intermediate temperatures to large cells that are reduced in numbers at lower temperatures but which represent the same total organic matter. The effect of this phenomenon on annual food chain efficiencies in both controlled and natural marine ecosystems is unknown.     

Effects of gonadal steroid hormones on hibernation in the Turkish hamster (Mesocricetus brandti)

Summary The Turkish hamster (Mesocricetus brandti) is a photoperiodic species in which exposure to a short day photoperiod induces gonadal atrophy. When hibernating male Turkish hamsters were administered testosterone via subcutaneous silastic capsules hibernation was abruptly terminated. The threshold serum testosterone level required to prevent hibernation was intermediate between the levels observed in males with fully-regressed and fully-functional testes. Dihydrotestosterone was as effective as testosterone in blocking hibernation. Estradiol had a partial inhibitory effect. Progesterone and corticosterone implants had no effect on hibernation. Similar results were obtained in female hamsters. The total period of hibernation for untreated males under laboratory conditions was usually 5–6 months. In most animals testicular growth began to occur toward the end of that period. As gonadal growth continued bouts of torpor decreased in frequency and duration, and hibernation was terminated when the testes approached reproductive size. Castrated males continued to hibernate much longer than intact animals. These observations suggest that in nature decreasing day length in the fall initiates gonadal regression which is followed by cold-induced hibernation. In the spring spontaneous recrudescence of the testes may lead to termination of the dormancy period. This mechanism may enable the species to prepare for the reproductive season with maximum efficiency.Supported by NIH Research Grant HD-10478 and by a grant from the Connecticut Research FoundationThe data in this paper were presented in part at the Annual Meeting of the American Society of Zoologists, Toronto, December 26–30, 1977     

Plasma exchange in the long-term management of Waldenstr?m's macroglobulinemia.

Two patients with Waldenström''s macroglobulinemia (WM), which had become resistant to cytotoxic drugs, were treated for features of the hyperviscosity syndrome by repeated plasma exchange with the continuous-flow blood-cell separator over periods of 36 and 28 months, respectively. After four initial weekly plasma exchanges the procedure was carried out every 4 to 6 weeks and both patients tolerated it well. Relative viscosity of the serum was maintained within the normal range in one patient, and both patients remained free of symptoms of the hyperviscosity syndrome. The results suggest that treatment of WM by long-term "maintenance" plasma exchange alone should be considered in any patient with complications due to chemotherapy or whose disease fails to respond to chemotherapy.     

Differential scanning calorimetry and enzymic activity of rat liver microsomes in the presence and absence of Δ1-tetrahydrocannabinol

The thermal transitions of rat liver microsomes and isolated lipids were investigated by using differential scanning calorimetry. Endothermic transitions at ≈?5°C and between ≈18° and 40°C were detected in the membranes and at ≈?10°C and between ≈10° and 20°C in the extracted lipids.Interaction with $\text{Δ}{}^1\text{-}\text{tetrahydrocannabinol}$ of microsomal membranes and of extracted lipids influences the thermotrophic behaviour as revealed by differential scanning calorimetry and eliminates the break in the Arrhenius plot of the enzymic activity of $\text{O-}\text{demethylase}$.