Enhancing the pharmacokinetic properties of recombinant factor VIII: first-in-human trial of glycoPEGylated recombinant factor VIII in patients with hemophilia A

BACKGROUND

N8-GP is a recombinant factor VIII (FVIII) with a site-directed glycoPEGylation for the purpose of half-life prolongation.

OBJECTIVES

To evaluate the safety and pharmacokinetic profiles of N8-GP in comparison with those of the patients' previous FVIII products.

PATIENTS/METHODS

This dose-escalation trial included previously treated patients with severe hemophilia A who received one of three dose levels (25, 50 or 75 U kg(-1) ) of N8-GP and FVIII product. Each dose escalation was preceded by safety and pharmacokinetic assessment. The trial was registered at www.clinicaltrials.gov (NCT01205724).

RESULTS

Twenty-six patients each received one dose of their previous FVIII product followed by the same, single dose of N8-GP. N8-GP, at any tested dose, was well tolerated, with a low frequency of adverse events. No new inhibitors against FVIII or N8-GP and no binding antibodies against N8-GP developed during the trial. The pharmacokinetics of N8-GP were dose-linear. The incremental recovery of N8-GP was 0.025 [(U mL(-1) )/(U kg(-1) )]. The clearance was 1.79 mL(-1)  h(-1)  kg(-1) . The estimated time from dosing of 50 U kg(-1) N8-GP to a plasma activity of 1% was 6.5 days (range: 3.6-7.9 days). The mean terminal half-life of N8-GP was 19.0 h (range: 11.6-27.3 h), 1.6-fold longer than that of the patients' previous products.

CONCLUSIONS

A single dose of up to 75 U kg(-1) N8-GP was well tolerated in patients with hemophilia A, with no safety concerns. N8-GP had a prolonged half-life, and FVIII:C activity remained at > 1% for longer than the patient's previous product. These results indicate that N8-GP has the potential to reduce dosing frequency during prophylaxis.

Comparative in vitro cytotoxicity study of carbon nanotubes and titania nanostructures on human lung epithelial cells

The aim of this study is to assess in vitro cytotoxic effects of titania nanostructures and carbon nanotubes (CNTs) by exposing A549 lung epithelial cell line to these materials. Titania nanotubes (TiNTs) were grown by hydrothermal treatment of TiO(2) nanoparticles, followed by annealing them at 400°C. The titania nanostructures obtained on annealing (mixture of nanotubes and nanorods) were hollow and open ended, containing 3-5 layers of titania sheets, with an internal diameter ∼3-5 nm and external diameter ∼8-10 nm, and a specific surface area of 265 m(2)/g. As-supplied single walled (SWCNTs) and microwave plasma enhanced chemical vapour deposition (MPCVD) grown multi walled carbon nanotubes (MWCNTs) were used in this study. The lengths and diameters of the SWCNTs were 5-10nm and 0.5-3 nm respectively. The lengths and diameters of the MWCNTs were 25-30 μm and 10-30 nm respectively. The cell viability was evaluated using the MTT (3-(4,-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium) assay. No significant cytotoxic effects of titania nanostructures were observed over a period of a week of testing time, while the presence of CNTs in some cases demonstrated significant cytotoxic effects. Finally, possible reason of cytotoxicity is discussed in the light of microstructures of materials.

Flexible trainees in Scotland

INTRODUCTION

Demand for flexible training is increasing. The contribution of such trainees to the trained medical workforce is not clear.

METHODS

All full time and flexible trainees in Scotland were 'tracked' at the completion of training.

RESULTS

80% of flexible trainees took up a consultant post of which 93% were in Scotland. 82% of full time trainees took up a consultant post of which 80% were in Scotland.

DISCUSSION

Flexible trainees become consultants at the same rate as their full time counterparts. They are commonly geographically tied and are therefore more likely to remain in Scotland and contribute to retention of doctors in this country.

Increased non-transferrin bound iron in plasma-depleted SAG-M red blood cell units

BACKGROUND AND OBJECTIVES

Non-transferrin bound iron (NTBI) is associated with increased morbidity in a number of transfusion-dependent disease states such as the severe haemoglobinopathies. We hypothesized that this may be related to excess NTBI present in plasma-depleted red blood cell units that are free of clear haemolysis.

MATERIALS AND METHODS

The level of NTBI was determined using the bleomycin assay in samples from 20 stored plasma-depleted red cell units, at approximate 5-day intervals up to day 33 after donation. Forty units of fresh-frozen plasma (FFP) and 40 units of platelet concentrates were used as negative controls, and samples from 12 units of FFP were also serially assessed.

RESULTS

Median [interquartile range (IQR)] NTBI was 0 microm (0-0.35) in samples taken from units 3-10 days after donation. Thereafter, the levels of NTBI increased, becoming significant (median 3.05; IQR: 0.05-6.7 microm) 17-22 days after donation. After 30 days, NTBI was detectable in all red cell units. NTBI was undetectable in platelet concentrates and FFP.

CONCLUSIONS

Increased levels of NTBI become detectable 17-22 days after donation and increase further with storage time. This excess NTBI may promote bacterial infection in iron-loaded individuals.

Reduced vitamin E antioxidant capacity in sickle cell disease is related to transfusion status but not to sickle crisis

In homozygous sickle cell disease (SCD), decreased serum Vitamin E is present. Excessive transfusions may lead to iron overload. We hypothesised a relationship between the two and found that Vitamin E type antioxidant capacity was significantly lower in 30 SCD patients than in 30 age- and sex-matched controls (P < 0.001). Antioxidant capacity was lower in 10 transfused patients compared with 20 non-transfused patients (P < 0.001). Transfusional iron overload in SCD may increase the potential for oxidative damage, and low antioxidant capacity may compound this effect.

Vitamin E correlates inversely with non-transferrin-bound iron in sickle cell disease

Decreased serum vitamin E levels are found in homozygous sickle cell disease (SCD). Excessive transfusions may lead high non-transferrin-bound iron (NTBI). Hypothesizing a relationship between the two, vitamin E (measured using high performance liquid chromatography) was significantly lower in 30 SCD patients than in 30 age-/sex-matched controls (P < 0.001), but NTBI (bleomycin assay) was higher (P < 0.001). Vitamin E was lower in 10 transfused patients than in 20 non-transfused patients (P < 0.001) with a significant inverse correlation between the NTBI and vitamin E (r = -0.58, P < 0.001). NTBI associated with iron overload in SCD may increase the potential for oxidative damage and low vitamin E activity may compound this effect.

[Visual acuity and ocular diseases in aged residents of nursing homes: study of 219 persons in Orléans]

PURPOSE

To measure the visual acuity and to determine the etiological causes of visual impairment in the elderly residing in nursing homes.

METHODS

219 elderly persons residing in nursing homes were examined in the residence. The ophthalmological examination consisted in a visual acuity measurement, a slit-lamp examination and a fundus examination.

RESULTS

This study included 145 women and 74 men. Mean age was 79.1 years (range 41-101 years). Visual acuity could be measured in 181 subjects (82.6%): it was 1/10 or worse in the better eye in 23 of them (13%) and 2/10 to 3/10 in 36 patients (20%). In 21 (17.6%) out of the 119 patients aged over 74 years, visual acuity was 1/10 or worse in the better eye. Visual impairment significantly increased with age (p < 0.05). There was no difference between men and women in the prevalence of visual impairment. Among the 55 subjects with visual impairment, the main causes of vision loss were: cataract in 36 patients (66%), age-related macular degeneration in 9 patients (16%) and optic neuropathies in 5 patients (9%). Only one (2.8%) out of the 36 patients with cataract could be operated.

CONCLUSION

The rate of visual impairment of people in nursing homes was higher than in corresponding age groups in the general population. The main cause of vision loss was cataract; however, only a few patients could benefit from an operation. These results confirmed that a systematic ophthalmologic examination should be performed before general health problems prevent patients from being operated.

Effect of NGF treatment on outcome measures in a rat model of middle cerebral artery occlusion

Ischemic insults to the brain result in a time-dependent increase in neuronal death that is responsible for some of the functional deficits associated with stroke. Our working hypothesis is that ischemia results in a prompt depletion of high energy phosphate species resulting in decreased pH and glutathione levels in brain in a temporal and spatial pattern that disrupts nerve growth factor homeostasis and increases neuronal apoptosis. Here we show hemispheric depletion of active phosphate species after ischemia. Also, we observed that the striatum is an early target for oxidative stress that is followed by energy metabolic impairment and altered neurotrophin levels that were detected by noninvasive magnetic resonance imaging (MRI) measurements of cytotoxicity and conventional biochemical determinations of apoptosis, glutathione, and nerve growth factor (NGF) protein levels in a pattern distinct from that observed in the hippocampus. Furthermore, early assessment of intracellular pH by 31P-magnetic resonance spectroscopy (31P-MRS) was a predictor of later infarct development as determined by MRI. We also show that pretreatment with pharmacological doses of NGF did not have overall significant beneficial consequences on irreversible ischemia in an intraluminal unilateral irreversible model of stroke in rat brain.

[Urinary infection in geriatric short stay: value of urinary strips]

The blinded study of CBUE (cytobacteriological urine examination) test strips was carried out in 100 patients (65 women, 35 men), mean age 85.52 +/- 6.28 years, admitted for a short stay in a geriatrics department. Urinary infection was present in 19% of the cases. Typical clinical signs (pollakiuria, dysuria, hematuria, burning upon voiding) were rare, less than 10%. General signs, such as deterioration of general status (65% of the cases) and loss of autonomy (53% of the cases), on the other hand, were predominant and their relatively unspecific nature required a reliable screening test for urinary infection. Good results of sensitivity (89.5%), specificity (98.7%), and the leukocytes/nitrites values, confirmed the validity of the urine test strip in hospitalized elderly patients. In addition, the negative predictive value of the combination leukocytes and nitrites (90.8%) would have prevented 71 samples from being sent to the laboratory for CBUE, resulting in an obvious financial savings.

[Replacement bladders in Oltrepo]

In our Department we performed 269 radical cystectomies from January 1985 to April 1996. As regard the urinary diversion 64 patients were undergone to a cutaneous ureterostomy; in 137 we performed a Wallace uretero-intestinal anastomosis; in 6 a Mauclaire rectal diversion; in 12 patients a Mainz Pouch II and 50 selected patients (44 man and 6 ladies) we performed a Vesica Ileale Padovana (VIP). In these cases the stage was lowly, good renal function, no are hydronephrosis. The patients were motivated for a long follow-up and preoperatively undergone to urethral biopsies. We have had the following complications: an early bowel obstruction, 4 wound infections and for the long term follow-up 2 inguinal hernias, 1 laparocele, 5 patients with bilateral hydronephrosis. At the moment we cannot state a correct oncological report for the short follow-up: only 1 patient died after 18 months for a pelvic relapse. We can suggest that VIP is a good solution for the ladies: its mandatory to take care of the urethra and the pelvic floor for a good continence limiting the lymphadenectomy. We haven't any suggestions about the deep of the colpectomy and the opportunity of the vaginal suspension.

Clinical directorates

Ten years ago the number of hospitals which had adopted a clinical directorate model of management could have been counted on the fingers of one hand. Today those that have not adopted some variant of the model can be counted in the same way: a meteoric rise by NHS standards.

Work redesign: a return to the basics

Through a work redesign project, one hospital focuses on the root of the nursing care delivery system. The premise was simple--a return to the basics to redefine barriers, needed system changes, and role responsibilities. Successful outcomes include improved recruitment and retention as well as increased patient, staff and community satisfaction.

Simultaneous auditory stimuli shorten saccade latencies

Eye movement responses induced by vestibular, smooth pursuit, and optokinetic stimulation are largely dependent on the velocity of the stimulus. Saccade latencies, on the other hand, are a function of the anatomic and physiologic components of the reflex. By producing an audible click simultaneously with the movement of a visual target used to stimulate a saccadic eye movement, the saccade latency is significantly shortened. This does not appear to be due to alerting. It is probably due to an auditory input to the superior colliculus which decreased threshold for initiating a saccadic eye movement. Twenty normal participants were tested with or without the click stimulus. Latencies were significantly shorter when the click stimulus was presented simultaneously with the eye movement. The anatomic pathways in this reflex are reviewed in the presentation. This study provides further information on sensory interaction in saccade reflexes and emphasizes the need to control stimulus conditions during saccade testing.

Cystine-glutamate transport interactions in rat renal cortical tubules, brushborder vesicles, and cultured renal tubule cells

Glutamate had no significant effect on the uptake of 0.025 mM cystine by isolated rat renal cortical tubules and brushborder membrane vesicles in contrast to lysine which significantly inhibits cystine transport. Glutamate, however, markedly inhibited cystine uptake by rat renal tubule cells grown in a serum-free, hormonally defined media for 5 days. Lysine also inhibited cystine transport in these cultured renal tubule cells.

Hemoglobin Great Lakes (beta 68 [E12] leucine replaced by histidine): a new high-affinity hemoglobin

Hemoglobin Great Lakes, beta 68 (E12) Leu replaced by His is a new high oxygen affinity hemoglobin variant discovered in a 29-yr-old female having numerous hospitalizations for thrombophlebitis associated with mild erythrocytosis. The mutant hemoglobin has normal stability and normal electrophoretic mobility, but increased oxygen affinity (P-50 16.1 mm Hg at 37 degrees C, pH 7.4) and reduced cooperativity. The abnormal beta-chain could be separated on globin chain chromatography on carboxymethyl/cellulose in spite of the normal electrophoretic mobility of the intact hemoglobin. The leucyl residue at beta 68th position (E12) is in the middle of E-helix, which is part of the heme pocket and next to the valine (E11), which is the heme binding site. The substitution of proline for leucine in hemoglobin Mizuho resulted in the distortion of tertiary structure of the beta-chains and lead to a serious instability of hemoglobin molecule. However, the substitution of this residue by histidine in hemoglobin Great Lakes is not associated with hemoglobin instability.

The effect of diamide on amino acid transport by rat renal cortex slices

Diamide directly added to renal cortical slices inhibits the uptake of amino acids. Steady-state kinetic analysis indicates an inhibition of alpha-amino acid influx without effect on efflux. The effect could be reversed by addition of pyruvate to the incubation medium. Although there was a good correlation of the transport effect of diamide with its ability to decrease cellular reduced glutathione concentration, there did not appear to be a necessary connection between them. This was shown by the fact that renal cortical slices stored at 4 degrees C have no alteration in amino acid uptake despite the fact that GSH concentration is as low as that seen with diamide. Diamide was shown to have a direct effect on the uptake of glycine by isolated renal brush border membrane vesicles.

Renal handling of [(14)C]mannose

The uptake of D-[(14)C]mannose by adult rat kidney cortex slices has been examined. The process involved appeared to be saturable and oxygen dependent and to be inhibited by glucose, galactose, chi-methyl-D-glucoside, and phlorizin. Extensive metabolism of the sugar occurred. (14)CO(2) was produced to an extent comparable to that from D-glucose. Radioactive compounds accumulated in the tissue, approximately 50% of which were in the form of phosphorylated or other polar intermediates. The remaining neutral fraction consisted of mannose with a small amount of label in glucose and an unidentified compound which behaves like an alditol. Mannose concentration in the intracellular fluid was never greater than that of the medium.

Regulation of amino acid transport in kidney cortex of newborn rats

After incubation at 37 degrees C the subsequent uptake of alpha-aminoisobutyric acid, cycloleucine, glycine, and L-proline by newborn (as compared to adult) rat kidney cortex slices is enhanced. The effect is abolished by the presence of cycloheximide, actinomycin D, and high concentrations of the above-mentioned amino acids in the medium during the 37 degrees C incubation prior to measurement of uptake. The data suggest that there is an adaptive control mechanism which is expressed on incubation at 37 degrees C and which can regulate amino acid transport in newborn rat kidney cortex.

Sugar transport: effect of temperature on concentrative uptake of alpha-methylglucoside by kidney cortex slices

The ability of renal cortical slices to accumulate a monosaccharide is enhanced at temperatures below 37 degrees C. Increase in concentration gradients occurs despite a decrease in total sugar flux. The apparent explanation for this paradox is a proportionally greater inhibition of efflux.

Separate transport systems for sugars and amino acids in developing rat kidney cortex

The ability of renal cortical slices of newborn and young rats to accumulate a nonmetabolizable sugar, alpha-methylglucoside, is slight and does not reach adult capacity until 25 days of age. However, a rudimentary sugar transport system is present, as indicated by a further decrease in accumulation in the presence of phlorizin or absence of sodium ion.Amino acid uptake in immature kidney tissue is not deficient; on the contrary, the tissue took up and concentrated more glycine and lysine than adult tissue. Decreased amino acid efflux from the immature cells appears to be the explanation. Concentration dependence of amino acid uptake was the same in 5-day-old and adult tissue. These differences between the transport characteristics of a model sugar and representative amino acids during development indicate separate transport systems for the two types of substrate.