Safety, pharmacokinetics, and pharmacodynamics of avoralstat, an oral plasma kallikrein inhibitor: phase 1 study

BACKGROUND

Avoralstat is a potent small-molecule oral plasma kallikrein inhibitor under development for treatment of hereditary angioedema (HAE). This first-in-human study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of avoralstat.

METHODS

This double-blind, placebo-controlled, ascending-dose cohort trial evaluated avoralstat single doses of 50, 125, 250, 500, and 1000 mg and multiple doses up to 2400 mg daily (100, 200, 400, and 800 mg every 8 h [q8 h] up to 7 days).

RESULTS

Avoralstat (n = 71) was generally well tolerated with no signals for a safety concern; there were no serious adverse events (AEs) or discontinuations due to AEs, and compared to placebo (n = 18), no notable difference in AEs. Four moderate severity AEs were reported in two subjects; syncope after a single 250 mg dose (one subject) and abdominal pain, back pain, and eczema after multiple doses of 800 mg avoralstat (one subject). For multiple-dose cohorts, the incidence of gastrointestinal AEs was highest at the 2400 mg/day dose. Elimination of avoralstat was bi-exponential with a terminal half-life of 12-31 h. Inhibition of plasma kallikrein was observed at all doses, and the degree of inhibition was highly correlated with avoralstat concentrations (R = 0.93). Mean avoralstat concentrations at doses ≥400 mg q8 h met or exceeded plasma kallikrein EC₅₀ values throughout the dosing interval.

CONCLUSION

Avoralstat was well tolerated, and drug exposure was sufficient to meet target levels for inhibition of plasma kallikrein. Based on these results, the 400 mg q8 h dose was selected for further evaluation in patients with HAE.

High energy, high repetition rate, second harmonic generation in large aperture DKDP, YCOB, and LBO crystals

We report on type-I phase-matched second harmonic generation (SHG) in three nonlinear crystals: DKDP (98% deuteration), YCOB (XZ plane), and LBO (XY plane), of 8 J, 10 Hz cryogenic gas cooled Yb:YAG laser operating at 1029.5 nm. DKDP exhibited an efficiency of 45% at a peak fundamental intensity of 0.24 GW/cm² for 10 Hz operation at 10 ns. At the same intensity and repetition rate, YCOB and LBO showed 50% and 65% conversion efficiencies, respectively. Significant improvement in conversion efficiency, to a maximum of 82%, was demonstrated in LBO at 0.7 GW/cm² and 10 Hz, generating output energy of 5.6 J at 514.75 nm, without damage or degradation. However, no improvement in conversion efficiency was recorded for YCOB at this increased intensity. Additionally, we present theoretically calculated temperature maps for both 10 J and 100 J operation at 10 Hz, and discuss the suitability of these three crystals for frequency conversion of a 100 J, 10 Hz diode pumped solid state laser (DPSSL).

Septic arthritis of the temporomandibular joint as a complication of acute otitis media in a child: A rare case and the importance of real-time PCR for diagnosis

We document the case of a 7-year-old boy who presented with pain in his left ear and trismus after a diagnosis of acute otitis media one week previously. His blood inflammatory markers were raised and magnetic resonance imaging (MRI) showed significant left temporomandibular joint effusion and partial attenuation of the left mastoid. A clinical diagnosis of septic arthritis of the TMJ was made and the patient was commenced on broad-spectrum antibiotics. Analysis using real time PCR enabled identification of the offending organism, confirmation of the diagnosis and antibiotic treatment to be specifically tailored for treatment.

Transmission grating stretcher for contrast enhancement of high power lasers

We propose, for the first time, a transmission grating stretcher for high power lasers and demonstrate its superiority over conventional, reflective gold grating stretchers in terms of pulse temporal quality. We show that, compared to a conventional stretcher with the same stretching factor, the transmission-grating based stretcher yields more than an order of magnitude improvement in the contrast pedestal. We have also quantitatively characterized the roughness of the grating surfaces and estimated its impact on the contrast pedestal.

Energy coupling in short pulse laser solid interactions and its impact for space debris removal

Significant advances have been made over the last decade to improve the performance, efficiency, and contrast of high peak and average power laser systems, driven by their use in a wide variety of fields, from the industrial to the scientific. As the contrast of the lasers has improved, interactions with contrasts of 10¹² are now routinely undertaken. At such high contrasts, there is negligible preplasma formation and the ionized surface layer created by subpicosecond-duration pulses typically forms a highly reflective "plasma mirror" capable of reflecting between 70% and 90% of the incident energy. Although such interactions are of significant interest for applications such as harmonic source production and to enable the underlying physics to be studied, their low absorption can limit their usefulness for applications such as space debris removal.

Effect of interferon-α on cortical glutamate in patients with hepatitis C: a proton magnetic resonance spectroscopy study

BACKGROUND

The development of depressive symptomatology is a recognized complication of treatment with the cytokine interferon-α (IFN-α) and has been seen as supporting inflammatory theories of the pathophysiology of major depression. Major depression has been associated with changes in glutamatergic activity and recent formulations of IFN-induced depression have implicated neurotoxic influences that could also lead to changes in glutamate function. The present study used magnetic resonance spectroscopy (MRS) to measure glutamate and its major metabolite glutamine in patients with hepatitis C who received treatment with pegylated IFN-α and ribavirin.

METHOD

MRS measurements of glutamate and glutamine were taken from a 25 × 20 × 20 mm voxel including the pregenual anterior cingulate cortex in 12 patients before and after 4-6 weeks of treatment with IFN.

RESULTS

IFN treatment led to an increase in cortical levels of glutamine (p = 0.02) and a significant elevation in the ratio of glutamine to glutamate (p < 0.01). Furthermore, changes in glutamine level correlated significantly with ratings of depression and anxiety at the time of the second scan.

CONCLUSIONS

We conclude that treatment with IFN-α is associated with MRS-visible changes in glutamatergic metabolism. However, the changes seen differ from those reported in major depression, which suggests that the pathophysiology of IFN-induced depression may be distinct from that of major depression more generally.

Characterizing critical care physician staffing in rural America: a description of Iowa intensive care unit staffing

PURPOSE

This study aimed to characterize intensive care unit (ICU) physician staffing patterns in a predominantly rural state.

MATERIALS AND METHODS

A prospective telephone survey of ICU nurse managers in all Iowa hospitals with an ICU was conducted.

RESULTS

Of 122 Iowa hospitals, 64 ICUs in 58 (48%) hospitals were identified, and 46 (72%) responded to the survey. Most ICUs (96%) used an open admission model and cared for undifferentiated medical and surgical patients (88%), and only 27% of open ICUs required critical care or pulmonary consultation for admitted patients. Most (59%) Iowa ICUs had a critical care physician or pulmonologist available, and high-intensity staffing was practiced in 30% of ICUs. Most physicians identified as practicing critical care (63%) were not board certified in critical care. Critical care physicians were available in a minority of hospitals routinely for inpatient intubation and cardiac arrest management (29% and 10%, respectively), and emergency physicians and other practitioners commonly responded to emergencies throughout the hospital.

CONCLUSIONS

Many Iowa hospitals have ICUs, and staffing patterns in Iowa ICUs mirror closely national staffing practices. Most ICUs are multispecialty, open ICUs in community hospitals. These factors should inform training and resource allocation for intensivists in rural states.

Effect of supplementation with vitamin D2-enhanced mushrooms on vitamin D status in healthy adults

Vitamin D deficiency is emerging worldwide and many studies now suggest its role in the development of several chronic diseases. Due to the low level of vitamin D naturally occurring in food there is a need for supplementation and use of vitamin D-enhanced products. The aim of the present study was to determine if daily consumption of vitamin D2-enhanced mushrooms increased vitamin D status in free-living healthy adults or affected markers of the metabolic syndrome. A total of ninety volunteers (aged 40-65 years) were randomly assigned to one of two 4-week studies: mushroom study (15 µg vitamin D2 or placebo mushroom powder) and capsule study (15 µg vitamin D3 or placebo capsules). Consumption of vitamin D2-enhanced mushrooms increased serum 25-hydroxyvitamin D2 (25(OH)D2) by 128 % from baseline (3·9 (sd 1·9) nmol/l; P < 0·05). Serum 25(OH)D3 increased significantly in the vitamin D3 capsule group (a 55 % increase from a baseline of 44.0 (sd 17·1) nmol/l; P < 0·05). Vitamin D status (25(OH)D) was affected only in the vitamin D3 group. Plasminogen activator inhibitor-1 was lowered by vitamin D2 intake. Vitamin D2 from enhanced mushrooms was bioavailable and increased serum 25(OH)D2 concentration with no significant effect on 25(OH)D3 or total 25(OH)D.

Stored blood transfusion induces transient pulmonary arterial hypertension without impairing coagulation in an ovine model of nontraumatic haemorrhage

BACKGROUND AND OBJECTIVES

Transfusion of blood products in particular older products is associated with patient morbidity. Previously, we demonstrated a higher incidence of acute lung injury in lipopolysaccharide-treated sheep transfused with stored blood products. As transfusion following haemorrhage is more common, we aimed to determine whether a 'first hit' of isolated haemorrhage would precipitate similar detrimental effects following transfusion and also disrupt haemostasis.

MATERIALS AND METHODS

Anaesthetized sheep had 33% of their total blood volume collected into Leukotrap bags (Pall Medical), which were processed into packed red blood cells and cross-matched for transfusion into other sheep. After 30 mins, the sheep were resuscitated with either: fresh (<5 days old) or stored (35-42 days old) ovine blood followed by 4% albumin to replacement volume, albumin alone or normal saline alone and monitored for 4 h.

RESULTS

The first hit of haemorrhage precipitated substantial decreases in mean arterial pressure however haemostasis was preserved. Transfusion of stored ovine blood induced (1) transient pulmonary arterial hypertension but no oedema and (2) reduced fibrinogen levels more than fresh blood, but neither induced coagulopathy. Thus, transfusion of stored blood affected pulmonary function even in the absence of overt organ injury.

CONCLUSION

The fact that stored blood transfusions: (1) did not induce acute lung injury in contrast to previous lipopolysaccharide-primed animal models identifies the 'first hit' as an important determinant of the severity of transfusion-mediated injury; (2) impaired pulmonary dynamics verifies the sensitivity and vulnerability of the pulmonary system to injury.

Fatal case of sorafenib-associated idiosyncratic hepatotoxicity in the adjuvant treatment of a patient with renal cell carcinoma

Background

Sorafenib is an orally available kinase inhibitor with activity at Raf, PDGFβ and VEGF receptors that is licensed for the treatment of advanced renal cell carcinoma (RCC) and hepatocellular carcinoma (HCC). Current evidence-based post-nephrectomy management of individuals with localized RCC consists of surveillance-based follow up. The SORCE trial is designed to investigate whether treatment with adjuvant sorafenib can reduce recurrence rates in this cohort.

Case presentation

Here we report an idiosyncratic reaction to sorafenib resulting in fatal hepatotoxicity and associated renal failure in a 62 year-old man treated with sorafenib within the SORCE trial.

Conclusion

This is the first reported case of sorafenib exposure associated fatal toxicity in the adjuvant setting and highlights the unpredictable adverse effects of novel adjuvant therapies.