Global resuscitation alliance utstein recommendations for developing emergency care systems to improve cardiac arrest survival.

INTRODUCTION: The Global Resuscitation Alliance (GRA) was established in 2015 to improve survival for Out- of-Hospital Cardiac Arrest (OHCA) using the best practices developed by the Seattle Resuscitation Academy. However, these 10 programs were recommended in the context of developed Emergency Care Systems (ECS). Implementing these programs can be challenging for ECS at earlier stages of development. We aimed to explore barriers faced by developing ECS and to establish pre-requisites needed. We also developed a framework by which developing ECS may use to build their emergency response capability. METHOD: A consensus meeting was held in Singapore on 1st-2nd August 2017. The 74 participants were key stakeholders from 26 countries, including Emergency Medical Services (EMS) directors, physicians and academics, and two Physicians who sit on the World Health Organisation (WHO) panel for development of Emergency Care Systems. Five discussion groups examined the chain of survival: community, dispatch, ambulance and hospital; a separate group considered perinatal resuscitation. Discussion points were voted upon to reach a consensus. RESULTS: The answers and discussion points from each groupwere classified into a table adapted from WHO's framework of development for Emergency Services. After which, it was used to construct the modified survival framework with the chain of survival as the backbone. Eleven key statements were then derived to describe the pre-requisites for achieving the GRA 10 programs. The participants eventually voted on the importance and feasibility of these 11 statements as well as the GRA 10 programs using a matrix that is used by organisations to prioritise their action steps. CONCLUSION: In this paper, we propose a modified framework of survival for developing ECS systems. There are barriers for developing ECS systems to improve OHCA survival rates. These barriers may be overcome by systematic prioritisation and cost-effective innovative solutions.

Energyscapes and prey fields shape a North Atlantic seabird wintering hotspot under climate change.

There is an urgent need for a better understanding of animal migratory ecology under the influence of climate change. Most current analyses require long-term monitoring of populations on the move, and shorter-term approaches are needed. Here, we analysed the ecological drivers of seabird migration within the framework of the energyscape concept, which we defined as the variations in the energy requirements of an organism across geographical space as a function of environmental conditions. We compared the winter location of seabirds with their modelled energy requirements and prey fields throughout the North Atlantic. Across six winters, we tracked the migration of 94 little auks (Alle alle), a key sentinel Arctic species, between their East Greenland breeding site and wintering areas off Newfoundland. Winter energyscapes were modelled with Niche Mapper™, a mechanistic tool which takes into account local climate and bird ecophysiology. Subsequently, we used a resource selection function to explain seabird distributions through modelled energyscapes and winter surface distribution of one of their main prey, Calanus finmarchicus. Finally, future energyscapes were calculated according to IPCC climate change scenarios. We found that little auks targeted areas with high prey densities and moderately elevated energyscapes. Predicted energyscapes for 2050 and 2095 showed a decrease in winter energy requirements under the high emission scenario, which may be beneficial if prey availability is maintained. Overall, our study demonstrates the great potential of the energyscape concept for the study of animal spatial ecology, in particular in the context of global change.

[Families' experiences and satisfaction with a pediatric emergency service]. / Familles fréquentant un service d'accueil des urgences pédiatriques : expérience, satisfaction et besoins.

OBJECTIVE: Today, pediatric emergency services receive a rising number of "non-urgent" cases, which are due to parental anxiety or a miscomprehension of medical explanations. The aim of this study was therefore to understand what those families experience and need when they consult in such cases, in order to respond with adapted solutions. METHODS: Semi-structured interviews and questionnaires with parents, after the consultation or in the waiting room. RESULTS: Based on the families' narratives, we present the results in six steps, which correspond to the steps they experience from the decision to go to the hospital to the consultation. Families' experiences are very satisfactory regarding the quality of medical care, the relationship between staff and children, and the staff's overall attitude. Critical points concern practical aspects (parking, food, and play facilities); the waiting time and the lack of information; and the communication between the medical staff and the parents, most particularly related to their anxiety and waiting time. DISCUSSION: The results show first that parents have multiple preoccupations: many stress factors and organizational difficulties are added to their child's disease. These preoccupations are mostly related to the lack of information about the waiting time, information that they would need to organize their day and their time in the hospital. Second, the results show that parental anxiety influences their decision to come to the emergency department, their experience of care and of the waiting time, and their judgment about the quality of the medical care. Considering this, families requested practical improvements (i.e., more toys in the waiting room), and suggest more communication and presence from the medical staff. Based on their demands, we suggest an agenda of care in four steps: a waiting time, a time for sharing, a time for information giving, and a validation time. CONCLUSIONS: Overall, parents are stressed and anxious when they come to the emergency department and request more reassurance, attention, and explanations from the healthcare staff. We propose a final "validation time" to verify that the medical explanations are understood as well as the emotional state of the family. In this way, we can ensure good follow-up care at home, avoid unnecessary readmissions, and promote parental health education.

Transfer of humoural immunity over two generations in urban pigeons.

Maternal antibodies (MatAb) are known to provide passive protection early in life for young vertebrates but their effects on the development of offspring immune response across generations are still unknown. Here, we investigated the effects of antigen exposure (keyhole limpet haemocyanin, KLH) experienced by urban pigeon (Columba livia) females on the amount of antigen-specific antibodies (Abs) transferred into the egg yolk of their daughters and on the humoural immune response towards this same antigen in their grandchildren. We found that chicks from KLH-injected maternal grandmothers had a higher humoural response than chicks from sham-injected grandmothers. However, we did not detect a significant effect of female KLH exposure on the ability of their daughters to transmit anti-KLH Abs into their eggs. These results suggest that antigen exposure at one generation may shape the immune profile of offspring over two next generations, although the underlying mechanisms remain to be investigated.

[What strategy for the screening of coronary artery disease in type 1 diabetes?]. / Oueue stratégie pour le dépistage de la maladie coronarienne dans te diabète de type 1?

Screening benefits for silent coronary artery disease in type 2 diabetes patients has been recently questioned following the publication of the DIAD study. For type 1 diabetes, there are no specific screening recommendations. For these patients, duration of the disease and microvascular complications are to be taken into account in assessing the risk of coronary artery disease. Intensive glycemic control reduces cardiovascular mortality. Other cardiovascular risk factors are also to be taken into consideration in assessing coronary risk, and should also be treated aggressively. Given the lack of prospective studies evaluating screening benefit for silent coronary artery disease in type 1 diabetes patients, screening strategies should be assessed depending on the context.

Immediate and delayed life history effects caused by food deprivation early in life in a short-lived lizard.

Detailed studies of the mechanisms driving life history effects of food availability are of prime importance to understand the evolution of phenotypic plasticity and the capacity of organisms to produce better adapted phenotypes. Food availability may influence life history trajectories through three nonexclusive mechanisms: (i) immediate and long-lasting effects on individual quality, and indirect delayed effects on (ii) intracohort and (iii) intercohort interactions. Using the common lizard (Zootoca vivipara), we tested whether a food deprivation during the two-first months of life influence life history (growth, survival, reproduction) and performance traits (immunocompetence, locomotor performances) until adulthood. We investigated the underlying mechanisms and their possible interactions by manipulating jointly food availability in a birth cohort and in cohorts of older conspecifics. Food deprivation had direct immediate negative effects on growth but positive long-lasting effects on immunocompetence. Food deprivation had also indirect delayed effects on growth, body size, early survival and reproduction mediated by an interaction between its direct effects on individual quality and its delayed effects on the intensity of intercohort social interactions combined with density dependence on body size. These results demonstrate that interactions between direct and socially mediated effects of past environments influence life history evolution in size-structured and stage-structured populations.

Blood glucose level on postoperative day 1 is predictive of adverse outcomes after cardiovascular surgery.

AIM: Hyperglycaemia is now a recognized predictive factor of morbidity and mortality after coronary artery bypass grafting (CABG). For this reason, we aimed to evaluate the postoperative management of glucose control in patients undergoing cardiovascular surgery, and to assess the impact of glucose levels on in-hospital mortality and morbidity. METHODS: This was a retrospective study investigating the association between postoperative blood glucose and outcomes, including death, post-surgical complications, and length of stay in the intensive care unit (ICU) and in hospital. RESULTS: A total of 642 consecutive patients were enrolled into the study after cardiovascular surgery (CABG, carotid endarterectomy and bypass in the lower limbs). Patients' mean age was 68+/-10 years, and 74% were male. In-hospital mortality was 5% in diabetic patients vs 2% in non-diabetic patients (OR: 1.66, P=0.076). Having blood glucose levels in the upper quartile range (> or =8.8 mmol/L) on postoperative day 1 was independently associated with death (OR: 10.16, P=0.0002), infectious complications (OR: 1.76, P=0.04) and prolonged ICU stay (OR: 3.10, P<0.0001). Patients presenting with three or more hypoglycaemic episodes (<4.1 mmol/L) had increased rates of mortality (OR: 9.08, P<0.0001) and complications (OR: 8.57, P<0.0001). CONCLUSION: Glucose levels greater than 8.8 mmol/L on postoperative day 1 and having three or more hypoglycaemic episodes in the postoperative period were predictive of mortality and morbidity among patients undergoing cardiovascular surgery. This suggests that a multidisciplinary approach may be able to achieve better postoperative blood glucose control.

Nocturnal hypoglycaemias in type 1 diabetic patients: what can we learn with continuous glucose monitoring?

AIM: In type 1 diabetic patients (T1DM), nocturnal hypoglycaemias (NH) are a serious complication of T1DM treatment; self-monitoring of blood glucose (SMBG) is recommended to detect them. However, the majority of NH remains undetected on an occasional SMBG done during the night. An alternative strategy is the Continuous glucose monitoring (CGMS), which retrospectively shows the glycaemic profile. The aims of this retrospective study were to evaluate the true incidence of NH in T1DM, the best SMBG time to predict NH, the relationship between morning hyperglycaemia and NH (Somogyi phenomenon) and the utility of CGMS to reduce NH. METHODS: Eighty-eight T1DM who underwent a CGMS exam were included. Indications for CGMS evaluation, hypoglycaemias and correlation with morning hyperglycaemias were recorded. The efficiency of CGMS to reduce the suspected NH was evaluated after 6-9 months. RESULTS: The prevalence of NH was 67% (32% of them unsuspected). A measured hypoglycaemia at bedtime (22-24 h) had a sensitivity of 37% to detect NH (OR=2.37, P=0.001), while a single measure < or =4 mmol/l at 3-hour had a sensitivity of 43% (OR=4.60, P<0.001). NH were not associated with morning hyperglycaemias but with morning hypoglycaemias (OR=3.95, P<0.001). After 6-9 months, suspicions of NH decreased from 60 to 14% (P<0.001). CONCLUSION: NH were highly prevalent and often undetected. SMBG at bedtime, which detected hypoglycaemia had sensitivity almost equal to that of 3-hour and should be preferred because it is easier to perform. Somogyi phenomenon was not observed. CGMS is useful to reduce the risk of NH in 75% of patients.

Coronary artery disease screening in diabetic patients: how good is guideline adherence?

INTRODUCTION: Diabetic patients are at high risk for coronary artery disease (CAD), which is the leading cause of death in this population. The Swiss Society of Endocrinology-Diabetology (SSED) recommends CAD screening for diabetic patients with > or = 2 additional cardiovascular risk factors (CVRF), by stress echocardiography (SE) or myocardial perfusion imaging (MPI). The aim of this study was to assess the application of these guidelines and the treatment of CVRF in the diabetes outpatient clinics of the five Swiss University Hospitals. METHODS: The study was initiated in Lausanne and the study questionnaires were circulated to the endocrinologists of the five Swiss University Hospitals. Practitioners were asked to include consecutive patients attending the diabetes outpatient clinics over one month. Prevalence of CAD, screening methods for CAD, prevalence of CVRF, biological analyses over the last 6 months and medical therapy were recorded. RESULTS: A total of 302 subjects were included. The mean age was 53 +/- 14 years, 68% had type 2 diabetes, 27% type 1 and 5% other types. Among T2DM with > or = 2 CVRF, 45% were screened for CAD according to SSED guidelines. In T2DM 25% had blood pressure < or = 130/80 mm Hg, 15% a lipid profile within target, 23% HbA1c < or = 7.0%. Overall, 2% achieved all 3 targets. CONCLUSIONS: Only 45% of T2DM with > or = 2 CVRF were screened for CAD according to SSED guidelines and 2% of T2DM had proper control over all CVRF. Efforts are still necessary to improve CAD prevention and screening of diabetic patients in Swiss University Hospitals.

Transient gene expression in HEK293 cells: peptone addition posttransfection improves recombinant protein synthesis.

Gene expression by large-scale transfection of mammalian cells is becoming an established technology for the fast production of milligram and even gram amounts of recombinant proteins (r-proteins). However, efforts are still needed to optimize production parameters in order to maximize volumetric productivities while maintaining product quality. In this study, transfection efficiency and volumetric productivity following transient gene expression in HEK293 cells were evaluated using green fluorescent protein (GFP) and human placental secreted alkaline phosphatase (SEAP) as reporter genes. We show that a single pulse of peptones (protein hydrolysates) to the cultures performed in a low serum (1%, v/v) and in serum-free medium results in a significant increase in volumetric protein productivity. Sixteen peptones from different sources were tested and almost all of them showed a positive effect on r-protein production. This effect, however, is time- and concentration-dependent. By using Tryptone N1 (a casein peptone, TN1) to feed the cultures at 24 h posttransfection (hpt), a 2-fold increase in volumetric SEAP productivity was obtained 5 days posttransfection. This effect was shown to be equal to that obtained when the culture was fed with a supplementary 4% (v/v) of serum. The positive effect of TN1 on protein production was also demonstrated with Tie2 protein ectodomain produced in serum-free medium. HPLC analysis of amino acids consumption/production during control batch and TN1 pulse culture showed some major differences in amino acid metabolism when using TN1 pulse. Asparagine, glycine, histidine, threonine, leucine, and valine show accumulation in the medium over the cultivation period instead of being consumed as observed in unfed sample (except for asparagine, which remained unchanged). Isoleucine, tyrosine, methionine, and phenylalanine all remained unchanged or slightly fluctuated in TN1-fed culture after the feeding pulse, while they were all steadily consumed in the control run. The relative abundance of SEAP's mRNA suggests that the improvement in protein yield results both from an increase of the translational activity and transcription efficiency. Further understanding of mechanisms by which amino acids/peptides regulate transcriptional and translational machinery in mammalian cells should facilitate the design of new strategies for the improvement of r-protein production by large-scale transfection.

Production of heterologous and chimeric scaffoldins by Clostridium acetobutylicum ATCC 824.

Clostridium acetobutylicum ATCC 824 converts sugars and various polysaccharides into acids and solvents. This bacterium, however, is unable to utilize cellulosic substrates, since it is able to secrete very small amounts of cellulosomes. To promote the utilization of crystalline cellulose, the strategy we chose aims at producing heterologous minicellulosomes, containing two different cellulases bound to a miniscaffoldin, in C. acetobutylicum. A first step toward this goal describes the production of miniCipC1, a truncated form of CipC from Clostridium cellulolyticum, and the hybrid scaffoldin Scaf 3, which bears an additional cohesin domain derived from CipA from Clostridium thermocellum. Both proteins were correctly matured and secreted in the medium, and their various domains were found to be functional.

Hydroxylated human homotrimeric collagen I in Agrobacterium tumefaciens-mediated transient expression and in transgenic tobacco plant.

Potential contamination of animal-derived collagen with pathogens has led to the demand for safe recombinant sources of this complex molecule. In continuation of our previous work [Ruggiero et al. (2000) FEBS Lett. 469, 132-136], here we show that it is possible to produce recombinant hydroxylated homotrimeric collagen in tobacco plants that are co-transformed with a human type I collagen and a chimeric proline-4-hydroxylase (P4H). This is to our knowledge the first time that transient expression in tobacco was used to improve the quality of a recombinant protein produced in plants through co-expression with an animal cell-derived modifying enzyme. We demonstrated the functionality of the new chimeric P4H and thus improved the thermal stability of recombinant collagen I from plants to 37 degrees C.

Unhydroxylated triple helical collagen I produced in transgenic plants provides new clues on the role of hydroxyproline in collagen folding and fibril formation.

Human unhydroxylated homotrimeric triple-helical collagen I produced in transgenic plants was used as an experimental model to provide insights into the role of hydroxyproline in molecular folding and fibril formation. By using chemically cross-linked molecules, we show here that the absence of hydroxyproline residues does not prevent correct folding of the recombinant collagen although it markedly slows down the propagation rate compared with bovine fully hydroxylated homotrimeric collagen I. Relatively slow cis-trans-isomerization in the absence of hydroxyproline likely represents the rate-limiting factor in the propagation of the unhydroxylated collagen helix. Because of the lack of hydroxylation, recombinant collagen molecules showed increased flexibility as well as a reduced melting temperature compared with native homotrimers and heterotrimers, whereas the distribution of charged amino acids was unchanged. However, unlike with bovine collagen I, the recombinant collagen did not self-assemble into banded fibrils in physiological ionic strength buffer at 20 degrees C. Striated fibrils were only obtained with low ionic strength buffer. We propose that, under physiological ionic strength conditions, the hydroxyl groups in the native molecule retain water more efficiently thus favoring correct fibril formation. The importance of hydroxyproline in collagen self-assembly suggested by others from the crystal structures of collagen model peptides is thus confirmed experimentally on the entire collagen molecule.

17beta-oestradiol stimulates capacitative Ca2+ entry in human endometrial cells.

Oestrogen plays an essential role in regulating growth and differentiation in the human endometrium which undergoes dynamic morphological and functional changes during the menstrual cycle in preparation for implantation. In this tissue, it has been suggested that intracellular calcium could be a key signal in transducing early responses to steroid hormones. Here, we have investigated the rapid effects of 17beta-oestradiol on [Ca2+]i in a human endometrial cell line (RL95-2). Using confocal imaging microscopy, we show that physiological concentrations of 17beta-oestradiol trigger rapid and transient increases in [Ca2+]i. Our results demonstrate that 17beta-oestradiol-induced [Ca2+]i variations are critically dependent on calcium influx via lanthanum-sensitive calcium channels. Moreover, the 17beta-oestradiol-induced Ca2+ influx is significantly increased by the depletion of intracellular stores by thapsigargin and decreased by chelerythrine chloride, an inhibitor of protein kinase C. These data indicate a non-genomic action of 17beta-oestradiol to stimulate capacitative Ca2+ entry through store-operated calcium channels via a PKC-sensitive pathway.

A reporter gene assay for high-throughput screening of G-protein-coupled receptors stably or transiently expressed in HEK293 EBNA cells grown in suspension culture.

We describe in detail a robust, sensitive, and versatile functional assay for G-protein-coupled receptors (GPCRs) expressed in human embryonic kidney (HEK) 293-EBNA (Epstein-Barr virus nuclear antigen) (designated 293E) cells. The ability to grow these cells in suspension, in conjunction with the use of the secreted form of the human placental alkaline phosphatase (SEAP) as the reporter enzyme transcriptionally regulated by 5-cyclic AMP (cAMP) response elements (CREs) (Chen et al., Anal. Biochem. 226, 349-354 (1995)), makes this CRE-SEAP assay potentially attractive for high-throughput screening (HTS). A 293E clonal cell line, stably transfected with the CRE-SEAP plasmid, was initially characterized with compounds known to activate intracellular signal transduction pathways similar to those activated by GPCRs. Forskolin and cAMP analogues were potent at inducing SEAP expression but calcium ionophores (A23187 and ionomycin) were without effect. The forskolin response was also potentiated by the protein kinase C activator phorbol myristate acetate as well as the phosphodiesterase inhibitor isobutylmethylxanthine. Previously established cell lines expressing the G(alphas)-coupled DP or the G(alphaq)-coupled-EP(1) prostanoid receptors were stably transfected with the reporter gene construct and clones were selected based on their ability to secrete SEAP upon agonist challenge. Pharmacological characterization of the DP and EP(1) receptors displayed a similar rank order of potency for several known prostanoids and related compounds to that previously reported using classical binding assays or other functional assays. The CRE-SEAP assay was also used to characterize the EP(1) receptor antagonists SC-51322, SC-51089, and AH6809. In summary, we have established a reporter gene assay for GPCRs that couple to both G(alphas) and G(alphaq) and is amenable to HTS of both agonists and antagonists.

Triple helix assembly and processing of human collagen produced in transgenic tobacco plants.

The use of tobacco plants as a novel expression system for the production of human homotrimeric collagen I is presented in this report. Constructs were engineered from cDNA encoding the human proalpha1(I) chain to generate transgenic tobacco plants expressing collagen I. The recombinant proalpha1(I) chains were expressed as disulfide-bonded trimers and were shown to fold into a stable homotrimeric triple helix. Moreover, the recombinant procollagen was subsequently processed to collagen as it occurs in animals. Large amounts of recombinant collagen were purified from field grown plant material. The data suggest that plants are a valuable alternative for the recombinant production of collagen for various medical and scientific purposes.

Chromosomal localization of cotransformed transgenes in the hexaploid cultivated oat Avena sativa L. using fluorescence in situ hybridization.

Fluorescence in situ hybridization (FISH) was used to localize two transgenes (gus and bar), carried on plasmids pACT-1F and pUBA, respectively, on mitotic metaphase squashes of T1 plants of the cultivated hexaploid oat Avena sativa L. cotransformed by microprojectile bombardment of embryogenic callus. Among the eight progeny analysed by FISH in each of two lines, we detected plants null, hetero- and homozygous for the two genes in one line, and plants null and heterozygous for the two genes in the other line. Our results demonstrated that in the two independent transformation events, the gus and bar genes had inserted in the same position relative to each other. In each transformation event, the insertions occurred on D satellite (SAT) chromosomes bearing a C genome translocation.

Interplay between Ca2+ release and Ca2+ influx underlies localized hyperpolarization-induced [Ca2+]i waves in prostatic cells.

Calcium seems to be a major second messenger involved in the regulation of prostatic cell functions, but the mechanisms underlying its control are poorly understood. We investigated spatiotemporal aspects of Ca2+ signals in the LNCaP cell line, a model of androgen-dependent prostatic cells, by using non-invasive external electric field pulses that hyperpolarize the anode facing membrane and depolarize the membrane facing the cathode. Using high-speed fluo-3 confocal imaging, we found that an electric field pulse (10-15 V/cm, 1-5 mA, 5 ms) initiated rapidly, at the hyperpolarized end of the cell, a propagated [Ca2+]i wave which spread through the cell with a constant amplitude and an average velocity of about 20 microns/s. As evidenced by the total wave inhibition either by the block of Ca2+ entry or the depletion of Ca2+ stores by thapsigargin, a specific Ca(2+)-ATPase inhibitor, the [Ca2+]i wave initiation may imply a localized Ca2+ influx linked to a focal auto-regenerative process of Ca2+ release. Using different external Ca2+ and Ca2+ entry blockers concentrations, Mn2+ quenching of fluo-3 and fura-2 fluorescence and inhibitors of InsP3 production, we found evidence that the [Ca2+]i wave progression required, in the presence of basal levels of InsP3, an interplay between Ca2+ release from InsP3-sensitive Ca2+ stores and Ca2+ influx through channels possibly activated by the [Ca2+]i rise.

[Ilio-femoral vein thrombosis treated with tissue plasminogen activator in a pregnant woman]. / Thrombose veineuse ilio-fémorale traitée par l'activateur tissulaire du plasminogène chez une femme enceinte.

A 27-year-old woman, after 31 weeks of amenorrhoea during her second pregnancy, developed a left external iliac and femoral deep vein thrombosis, confirmed by venous ultrasonography and magnetic resonance imaging. The infusion of tissue plasminogen activator (rt-PA: 1.2 mg/kg, i.e. 80 mg over 3 hours), on the 2nd day, allowed revascularization of the femoral junction, while the external iliac vein remained occluded. The patient did not develop pulmonary embolism or haemorrhage, particularly obstetric haemorrhage. The subsequent pregnancy was uneventful until delivery, six weeks later, of a normal child. Three years later, the patient has no sequelae of her deep vein thrombosis. When required by the patient's condition, it seems that rt-PA can be used to treat severe deep vein thrombosis during pregnancy, either isolated or complicated by pulmonary embolism. Very rigorous cardiological, obstetric and laboratory surveillance is essential. A sufficient dosage, identical to that used in clinical settings other than pregnancy and a brief treatment duration (2 to 3 hours) are probably more effective and more reliable than lower doses continued for several days. However, the risk of haemorrhage remains difficult to predict and its prognosis, especially foetal, is often very poor. A larger series of cases is therefore necessary before this drug can unreservedly recommended in pregnant women.

On-line monitoring of respiration in recombinant-baculovirus infected and uninfected insect cell bioreactor cultures.

Respiration rates in Spodoptera frugiperda (Sf-9) cell bioreactor cultures were successfully measured on-line using two methods: The O(2) uptake rate (OUR) was determined using gas phase pO(2) values imposed by a dissolved oxygen controller and the CO(2) evolution rate (CER) was measured using an infrared detector. The measurement methods were accurate, reliable, and relatively inexpensive. The CER was routinely determined in bioreactor cultures used for the production of several recombinant proteins. Simple linear relationships between viable cell densities and both OUR and CER in exponentially growing cultures were used to predict viable cell density. Respiration measurements were also used to follow the progress of baculoviral infections in Sf-9 cultures. Infection led to increases in volumetric and per-cell respiration rates. The relationships between respiration and several other culture parameters, including viable cell density, cell protein, cell volume, glucose consumption, lactate production, viral titer, and recombinant beta-galactosidase accumulation, were examined. The extent of the increase in CER following infection and the time postinfection at which maximum CER was attained were negatively correlated with the multiplicity of infection (MOI) at multiplicities below the level required to infect all the cells in a culture. Delays in the respiration peak related to the MOI employed were correlated with delays in the peak in recombinant protein accumulation. DO levels in the range 5-100% did not exert any major effects on viable cell densities, CER, or product titer in cultures infected with a baculovirus expressing recombinant beta-galactosidase.