Comparison of two direct neutralizing assay formats using recombinant follicle-stimulating hormone as agonist.

Characterizing anti-drug antibodies for neutralizing activity is commonly part of the immunogenicity testing package for most therapeutic proteins. Cell-based neutralization assays can generally be categorized as direct- or indirect assays depending on whether they are associated with therapeutics with agonistic- or antagonistic properties. This paper's aim is a comparison of the two direct neutralization assay formats; the variable- and fixed concentration assay format, using recombinant follicle-stimulating hormone as drug agonist. Essential validation- and performance parameters, such as sample through-put, cut-point, precision, sensitivity and drug tolerance, were compared. The fixed concentration assay format offers superior sample through-put (40 versus 6 samples), precision (coefficient of variation of ≤14% versus 34%) and almost 6 times better sensitivity and is generally recommended as the better option particularly for quasi-quantitative assessments of neutralizing antibodies.

Seroepidemiology as basis for design of a human papillomavirus vaccination program.

We have performed a serological survey of HPV type 16-antibody prevalence by age and sex in Sweden and used it as a basis for modelling the optimal vaccination strategies in this population. Samples of 3,317 subjects were tested for HPV16-specific antibodies. The observed age-specific seroprevalences along with sexual behaviour data were used to infer parameter values for a mathematical model representing Sweden and the preventive effect of possible strategies estimated. By the year 2055, vaccination of females starting at age 12 in 2008 was most efficient, estimated to prevent 5.8 million cumulative HPV16 infections. Catch-up programs had a strong additional preventive effect. Vaccination also targeting males increased protective effect by about 4%, but had lower preventive effect per vaccination given. Addition of an HPV serosurvey to existing models and data has enabled us to estimate effect of different vaccination strategies, optimized to the HPV epidemiology in our population.

JC viral loads in patients with Crohn's disease treated with immunosuppression: can we screen for elevated risk of progressive multifocal leukoencephalopathy?

BACKGROUND AND AIMS: Anti-alpha4 integrin therapy with natalizumab is efficacious in refractory Crohn's disease and in multiple sclerosis, but carries an estimated 1/1000 risk of progressive multifocal leukoencephalopathy (PML) caused by reactivation of latent JC virus infection. Although anti-alpha4 integrin therapies are likely to be introduced in the clinic, screening for the risk of PML has not been developed. METHODS: We prospectively collected urine, serum, plasma and buffy coats from 125 patients with Crohn's disease, 100 control subjects with gastrointestinal (GI) disease, and 106 healthy volunteers. Four to eight weeks after this first sample collection, we additionally collected a set of urine, serum, plasma and buffy coat samples from the 125 patients with Crohn's disease, and a next set of samples was collected 12-16 weeks after the first collection. JC viral loads were determined with quantitative real-time polymerase chain reaction (PCR), and JC virus seroprevalence with a specific enzyme-linked immunosorbant assay (ELISA). RESULTS: The overall JC virus seroprevalence was 65%. JC virus DNA copies were detected in the urine from 29-44% of subjects, both those with Crohn's disease and controls. Median viral loads were significantly higher in patients with Crohn's disease who were immunosuppressed (7.36x10(6) copies/ml) compared to healthy volunteers (2.77x10(5) copies/ml) and compared to GI controls (1.8x10(6) copies/ml). Clearance at any time point occurred in 4/107 (3.7%) subjects only. JC viraemia was found in two patients with Crohn's disease. CONCLUSIONS: The natural history of JC virus in patients with Crohn's disease is still unknown. Our study results show that JC virus latency and urine viral shedding is frequent in immunosuppressed patients with Crohn's disease. More prospective studies are needed in order to agree on possible recommendations concerning the exclusion of patients with JCV viraemia from anti-alpha4 integrin treatment.

Deletion of a major neutralizing epitope of human papillomavirus type 16 virus-like particles.

Human papillomavirus type 16 (HPV-16) is a major cause of human cancer. Effective prophylactic vaccines are based on type-specific neutralizing antibodies. A major neutralizing epitope has been defined by the monoclonal antibody H16.V5. To investigate the importance of this epitope for overall immunogenicity of HPV-16, HPV-16 virus-like particles devoid of the H16.V5 epitope were engineered by site-directed mutagenesis of ten non-conserved, surface-exposed residues. Removal of the H16.V5-defined epitope had only a marginal effect on antigenic reactivity with antibodies in sera from infected subjects, but affected immunogenicity in experimental immunization of mice, with reduced induction of both antibody responses and CTL responses.

Reversal of 'refractory septic shock' by infusion of amrinone and angiotensin II in an anthracycline-treated patient.

A 53-year-old granulocytopenic woman with malignant lymphoma treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy, including doxorubicin (Adriamycin) and autologues bone marrow transplantation, presented in the clinical state of "refractory septic shock" caused by Escherichia coli. Despite inotropic treatment with dopamine, dobutamine, and norepinephrine infusion, the patient's condition did not improve, but during treatment with amrinone and angiotensin II infusion, the septic shock was reversed. The patient was monitored with a pulmonary artery catheter and underwent repeated echocardiographic examinations. Antibiotic treatment with thienamycin and floxacillin was given. The initial reduction in cardiac performance in this patient may be explained by a state of true down-regulation of the myocardial beta-receptors. Apparently these beta-receptors were bypassed via the enzymatic action of amrinone upon cyclic monoadenosine phosphate. This is, to our knowledge, the first doxorubicin-treated patient with septic shock refractory to conventional vasopressor therapy whose condition reversed by inotropic treatment with amrinone and angiotensin II. This treatment may prove to be an alternative choice for patients developing "refractory septic shock" unresponsive to treatment with norepinephrine, dobutamine, and dopamine.

[Description of activities in the neonatal department at Rigshospitalet during the period 1983-1990]. / Aktivitetsbeskrivelse for Rigshospitalets neonatalafdeling 1983-1990.

Since 1983, the gestational age (GA in completed weeks), use of mechanical ventilation, duration of hospitalization and the diagnosis-related group were registered routinely for all infants admitted to the Neonatal Department, Rigshospitalet, Copenhagen. The data were analysed concerning the 6,636 infants treated during the seven-year period until the end of 1991. The annual number of admissions decreased during the period (p < 0.001) whereas the number of extremely preterm infants (GA < 28 weeks) increased from 30 to 45 annually (p < 0.05). The total mortality remained constant at about 7% of all admissions but decreased significantly for the extremely preterm infants. The use of mechanical ventilation was almost halved during the period: from 235 to 146 annually. Even where the extremely preterm infants were concerned, the use of mechanical ventilation decreased from 77% to 51% (p < 0.05). The gestational age specific duration of hospitalization for the surviving infants remained constant. The number of infants with surgical anomalies or congenital heart disease increased among the infants born at term. The cost of treatment increased by 40% in fixed prices to DDK 4,000 per day (approximately 333 pounds). The authors conclude that the introduction of nasal continuous positive airway pressure (CPAP) has permitted treatment of moderately preterm infants in county hospitals and has also resulted in avoidance of mechanical ventilation in extremely preterm infants without preventing improved survival. Although the patients have become more selected, the duration of hospitalization remains unchanged.

The nursing care recording system. A preliminary study of a system for assessment of nursing care demands in the ICU.

A new system, Nursing Care Recording (NCR), for the recording of nursing care in a general ICU is presented. NCR classifies ICU patients according to their need for intensive nursing care. Comparing the NCR with the Therapeutic Intervention Scoring System (TISS), a correlation coefficient of 0.60 was found. The main difference between the two systems was related to recording procedures allowing changes in nursing intensity within a 24-h period, reflecting patient improvement due to therapy, which was detected by NCR but not by TISS. NCR can be used to estimate nursing capacity during different shifts and may be useful in the assessment of the total nursing staff necessary for a given ICU. It is suggested that NCR will allow detection of changes in the nursing care work load, whether this change is due to new activities in the unit or to alterations in the individual patient care.

Changes in cerebral oxygenation and cerebral blood volume during endotracheal suctioning in ventilated neonates.

The effect of endotracheal suctioning on cerebral haemodynamics was investigated in 29 newborn infants with a mean gestational age of 31 weeks (range 25-40 weeks). Prior to one of two suctioning procedures, the inspiratory fraction of oxygen was increased by 10%. Brain oxygenation and total haemoglobin concentration were estimated continuously by near infrared spectroscopy. Mean arterial blood pressure, arterial blood oxygen saturation and carbon dioxide tension were recorded simultaneously. Brain oxygenation decreased in parallel with arterial oxygen saturation during suctioning. Preoxygenation ameliorated the decrease in brain oxygenation and arterial oxygen saturation whereas there was no benefit with regard to the changes in total haemoglobin concentration, carbon dioxide tension or mean arterial pressure. Changes in total haemoglobin concentration were related closely to concomitant changes in carbon dioxide tension (p less than 0.0001) but unrelated to changes in mean arterial pressure or arterial oxygen saturation. Our findings suggest that cerebral blood volume may react to changes in carbon dioxide tension during endotracheal suctioning in mechanically ventilated neonates. Apparently, preoxygenation prior to suctioning does not ameliorate the stress in normoxic infants.

Coagulase-negative staphylococci in a newborn with a cardiac vascular prosthesis. Case report.

A case of septicemia with coagulase-negative staphylococci in a newborn with a vascular graft is discussed. Nineteen different isolates of coagulase-negative staphylococci were isolated from four different blood cultures. Eleven of the isolates belonged to one strain, which showed slight variation; the remaining seven isolates belonged to six different strains. The patient was treated for a prolonged period with antibiotics and seemed to respond. The diagnosis and proper treatment are discussed.