Haptoglobin Attenuates Cerebrospinal Fluid Hemoglobin-Induced Neurological Deterioration in Sheep

Secondary brain injury (SBI) occurs with a lag of several days post-bleeding in patients with aneurysmal subarachnoid hemorrhage (aSAH) and is a strong contributor to mortality and long-term morbidity. aSAH-SBI coincides with cell-free hemoglobin (Hb) release into the cerebrospinal fluid. This temporal association and convincing pathophysiological concepts suggest that CSF-Hb could be a targetable trigger of SBI. However, sparse experimental evidence for Hb's neurotoxicity in vivo defines a significant research gap for clinical translation. We modeled the CSF-Hb exposure observed in aSAH patients in conscious sheep, which allowed us to assess neurological functions in a gyrencephalic species. Twelve animals were randomly assigned for 3-day bi-daily intracerebroventricular (ICV) injections of either Hb or Hb combined with the high-affinity Hb scavenger protein haptoglobin (Hb-Hp, CSL888). Repeated CSF sampling confirmed clinically relevant CSF-Hb concentrations. This prolonged CSF-Hb exposure over 3 days resulted in disturbed movement activity, reduced food intake, and impaired observational neuroscores. The Hb-induced neurotoxic effects were significantly attenuated when Hb was administered with equimolar haptoglobin. Preterminal magnetic resonance imaging (MRI) showed no CSF-Hb-specific structural brain alterations. In both groups, histology demonstrated an inflammatory response and revealed enhanced perivascular histiocytic infiltrates in the Hb-Hp group, indicative of adaptive mechanisms. Heme exposure in CSF and iron deposition in the brain were comparable, suggesting comparable clearance efficiency of Hb and Hb-haptoglobin complexes from the intracranial compartment. We identified a neurological phenotype of CSF-Hb toxicity in conscious sheep, which is rather due to neurovascular dysfunction than structural brain injury. Haptoglobin was effective at attenuating CSF-Hb-induced neurological deterioration, supporting its therapeutic potential.

Simulation-based establishment of base pools for a hybrid breeding program in winter rapeseed

KEY MESSAGE

Simulation planned pre-breeding can increase the efficiency of starting a hybrid breeding program. Starting a hybrid breeding program commonly comprises a grouping of the initial germplasm in two pools and subsequent selection on general combining ability. Investigations on pre-breeding steps before starting the selection on general combining ability are not available. Our goals were (1) to use computer simulations on the basis of DNA markers and testcross data to plan crosses that separate genetically two initial germplasm pools of rapeseed, (2) to carry out the planned crosses, and (3) to verify experimentally the pool separation as well as the increase in testcross performance. We designed a crossing program consisting of four cycles of recombination. In each cycle, the experimentally generated material was used to plan the subsequent crossing cycle with computer simulations. After finishing the crossing program, the initially overlapping pools were clearly separated in principal coordinate plots. Doubled haploid lines derived from the material of crossing cycles 1 and 2 showed an increase in relative testcross performance for yield of about 5% per cycle. We conclude that simulation-designed pre-breeding crossing schemes, that were carried out before the general combining ability-based selection of a newly started hybrid breeding program, can save time and resources, and in addition conserve more of the initial genetic variation than a direct start of a hybrid breeding program with general combining ability-based selection.

Relationship between magnetic resonance imaging findings and histological grade in spinal peripheral nerve sheath tumors in dogs

BACKGROUND

Peripheral nerve sheath tumors (PNSTs) are a group of neoplasms originating from Schwann cells or pluripotent cell of the neural crest. Therapeutic options and prognosis are influenced by their degree of malignancy and location.

HYPOTHESIS/OBJECTIVES

Identify magnetic resonance imaging (MRI) features predictive of PNST histologic grade.

ANIMALS

Forty-four dogs with histopathological diagnosis of spinal PNSTs and previous MRI investigation.

METHODS

A multicenter retrospective study including cases with (a) histopathologic diagnosis of PNST and (b) MRI studies available for review. Histologic slides were reviewed and graded by a board-certified pathologist according to a modified French system (FNCLCC) for grading soft tissue sarcomas. The MRI studies were reviewed by 2 board-certified radiologists blinded to the grade of the tumor and the final decision on the imaging characteristics was reached by consensus. Relationships between tumor grade and histological and MRI findings were assessed using statistical analysis.

RESULTS

Forty-four cases met inclusion criteria; 16 patients were PNSTs Grade 1 (low-grade), 19 were PNSTs Grade 2 (medium-grade), and 9 were PNSTs Grade 3 (high-grade). Large volume (P = .03) and severe peripheral contrast enhancement (P = .04) were significantly associated with high tumor grade. Degree of muscle atrophy, heterogeneous signal and tumor growth into the vertebral canal were not associated with grade.

CONCLUSIONS AND CLINICAL IMPORTANCE

Grade of malignancy was difficult to identify based on diagnostic imaging alone. However, some MRI features were predictive of high-grade PNSTs including tumor size and peripheral contrast enhancement.

Preliminary Investigation of Side Effects of Polymyxin B Administration in Hospitalized Horses

Neuro- and nephrotoxicity of polymyxins are known but clinical studies in horses are lacking. The aim of this study was to describe neurogenic and nephrogenic side effects of hospitalized horses receiving Polymyxin B (PolyB) as part of their treatment plan. Twenty horses diagnosed with surgical colic (n = 11), peritonitis (n = 5), typhlocolitis (n = 2), pneumonia, and pyometra (each n = 1) were included. Antimicrobial treatment was randomized to GENTA (gentamicin 10 mg/kg bwt q24 h IV, penicillin 30.000 IU/kg q6 h IV) or NO GENTA (marbofloxacin 2 mg/kg bwt q24 h IV, penicillin 30.000 IU/kg q6 h IV). The duration of PolyB treatment ranged from 1 to 4 days. Clinical and neurological examinations were performed, and serum PolyB concentrations were measured daily during and three days following PolyB treatment. Urinary analysis, plasma creatinine, urea and SDMA were assessed every other day. Video recordings of neurological examinations were graded by three blinded observers. All horses showed ataxia during PolyB treatment in both groups (median maximum ataxia score of 3/5, range 1-3/5). Weakness was detected in 15/20 (75%) horses. In 8/14 horses, the urinary γ-glutamyltransferase (GGT)/creatinine ratio was elevated. Plasma creatinine was mildly elevated in 1/16 horses, and SDMA in 2/10 horses. Mixed-model analysis showed a significant effect of time since last PolyB dose (p = 0.0001, proportional odds: 0.94) on the ataxia score. Ataxia and weakness should be considered as reversible adverse effects in hospitalized horses receiving PolyB. Signs of tubular damage occurred in a considerable number of horses; therefore, the nephrotoxic effect of polymyxins should be considered and urinary function monitored.

Direct access to millions of mutations by whole genome sequencing of an oilseed rape mutant population

Induced mutations are an essential source of genetic variation in plant breeding. Ethyl methanesulfonate (EMS) mutagenesis has been frequently applied, and mutants have been detected by phenotypic or genotypic screening of large populations. In the present study, a rapeseed M₂ population was derived from M₁ parent cultivar 'Express' treated with EMS. Whole genomes were sequenced from fourfold (4×) pools of 1988 M₂ plants representing 497 M₂ families. Detected mutations were not evenly distributed and displayed distinct patterns across the 19 chromosomes with lower mutation rates towards the ends. Mutation frequencies ranged from 32/Mb to 48/Mb. On average, 284 442 single nucleotide polymorphisms (SNPs) per M₂ DNA pool were found resulting from EMS mutagenesis. 55% of the SNPs were C → T and G → A transitions, characteristic for EMS induced ('canonical') mutations, whereas the remaining SNPs were 'non-canonical' transitions (15%) or transversions (30%). Additionally, we detected 88 725 high confidence insertions and deletions per pool. On average, each M₂ plant carried 39 120 canonical mutations, corresponding to a frequency of one mutation per 23.6 kb. Approximately 82% of such mutations were located either 5 kb upstream or downstream (56%) of gene coding regions or within intergenic regions (26%). The remaining 18% were located within regions coding for genes. All mutations detected by whole genome sequencing could be verified by comparison with known mutations. Furthermore, all sequences are accessible via the online tool 'EMSBrassica' (http://www.emsbrassica.plantbreeding.uni-kiel.de), which enables direct identification of mutations in any target sequence. The sequence resource described here will further add value for functional gene studies in rapeseed breeding.

Manifestations of hypertensive encephalopathy in cats

OBJECTIVES

Hypertensive encephalopathy in cats is an important entity but is underestimated in clinical practice. This could be explained, in part, by non-specific clinical signs. The objective of this study was to characterise the clinical manifestations of hypertensive encephalopathy in cats.

METHODS

Cats with systemic hypertension (SHT) recognised by routine screening, associated with underlying predisposing disease or a clinical presentation suggestive of SHT (neurological or non-neurological), were prospectively enrolled over a 2-year period. Confirmation of SHT was based on at least two sets of measurements of systolic blood pressure >160 mmHg by Doppler sphygmomanometry.

RESULTS

Fifty-six hypertensive cats with a median age of 16.5 years were identified; 31 had neurological signs. In 16/31 cats, neurological abnormalities were the primary complaint. The other 15 cats were first presented to the medicine or ophthalmology service, and neurological disease was recognised based on the cat's history. The most common neurological signs were ataxia, various manifestations of seizures and altered behaviour. Individual cats also showed paresis, pleurothotonus, cervical ventroflexion, stupor and facial nerve paralysis. In 28/30 cats, retinal lesions were detected. Of these 28 cats, six presented with a primary complaint of visual deficits, and neurological signs were not the primary complaint; nine presented with non-specific medical issues, without suspicion of SHT-induced organ damage; in 13 cats, neurological issues were the primary complaint and fundic abnormalities were detected subsequently.

CONCLUSIONS AND RELEVANCE

SHT is common in older cats and the brain is an important target organ; however, neurological deficits are commonly ignored in cats with SHT. Gait abnormalities, (partial) seizures and even mild behavioural changes should prompt clinicians to consider the presence of SHT. A fundic examination in cats with suspected hypertensive encephalopathy is a sensitive test to support the diagnosis.

A shortened whole brain radiation therapy protocol for meningoencephalitis of unknown origin in dogs

Introduction

A variety of treatment options have been described for canine meningoencephalitis of unknown origin (MUO). Few studies focused on radiation therapy as a second line immunomodulating treatment, implicating its effective use. However, a standard radiation therapy protocol is lacking, and further research will help to evaluate the effect of different dose regimens.

Methods

Ten dogs diagnosed with MUO based on MRI and CSF findings were prospectively enrolled. The dogs were treated with a shortened whole brain radiation therapy protocol (5 × 4 Gy) in combination with prednisolone. Neurologic changes were quantified using an established scoring scheme. Follow-up MRI and CSF examination was scheduled three months after radiation therapy. Overall survival and time to progression were calculated. Histopathology of the brain was performed in case of death.

Results

Seven dogs were diagnosed de novo and three had a history of relapsing MUO. Neurological status improved in all 10 dogs during radiation therapy, with 4/10 returning to normal shortly after radiation therapy. Three dogs died within the first three months after radiation therapy. At follow-up MRI lesions completely resolved in two dogs, partially resolved in five dogs, and progressed in one dog. After follow-up MRI, dogs were further treated with prednisolone monotherapy (two dogs) and additional immunosuppressant drugs (five dogs). Overall, four dogs showed disease progression, with a mean time to progression of 691 days (95%CI: 396-987) and mean overall survival for all dogs was 723 days (95%CI: 436-1011) (both medians not reached). Histopathology confirmed MUO in three dogs but was suggestive for oligodendroglioma in one dog. Radiation induced side effects were not seen.

Conclusion

Shortened whole-brain radiation therapy could be an additional treatment option for MUO in conjunction to prednisolone, specifically for cases that require rapid relief of symptoms and with relapsing history.

Solitary intraventricular tumors in dogs and cats treated with radiotherapy alone or combined with ventriculoperitoneal shunts: A retrospective descriptive case series

BACKGROUND

Intraventricular tumors are rare, optimal treatment is not defined. Symptomatic patients often exhibit life-threatening hydrocephalus. With several months time-to-effect after radiotherapy (RT), increased intracranial pressure is concerning. This increase in pressure can be overcome by ventriculoperitoneal shunting (VPS).

OBJECTIVES

Retrospective evaluation of outcome and complications in dogs and cats with intracranial tumors treated with either RT or VPS/RT.

ANIMALS

Twelve client-owned cats and dogs.

METHODS

Dogs and cats with symptomatic intraventricular tumors treated with definitive-intent RT or VPS/RT were included in a retrospective, descriptive case series. Complications, tumor volume evolution, time-to-progression, and survival time were determined.

RESULTS

Twelve animals were included: 1 cat and 5 dogs treated with single-modality RT and 4 cats and 2 dogs treated with VPS/RT. Neurological worsening seen in 4/6 animals during single-modality RT and 2/6 died during RT (suspected brain herniation). All dogs with VPS normalized clinically by the end of RT or earlier. Complications occurred in 4/6 animals, all but 1 were successfully managed surgically. Imaging follow-up in 8 animals surviving RT showed a marked decrease in tumor volume. Median survival time was 162 days (95% confidence interval [CI]: 16; infinity) for animals treated with RT and 1103 days (95%CI: 752; infinity) for animals treated with VPS/RT. Median time-to-progression was 71 days (95%CI: 7; infinity) and 895 days (95%CI: 704; infinity) for each group, respectively. Two dogs died because of intraventricular metastasis 427 and 461 days after single-modality RT.

CONCLUSIONS AND CLINICAL IMPORTANCE

Ventriculoperitoneal shunting led to rapid normalization of neurological signs and RT had a measurable effect on tumor volume. Combination of VPS/RT seems to be beneficial.

Adverse effects of polymyxin B administration to healthy horses

BACKGROUND

Polymyxin B (PolyB) is used to treat endotoxemia in horses; neurologic and nephrogenic adverse effects occur in humans.

OBJECTIVES

To describe PolyB adverse effects in horses.

ANIMALS

Five healthy horses (ataxia 0/5), 1 horse with cervical osteoarthritis (ataxia 1/5).

METHODS

Prospective blinded randomized cross-over trial; 3-weeks wash out. Horses received PolyB (PolyB 6000 IU/kg IV, 7 doses q12h, n = 6) and PolyB/gentamicin (PolyB 6000 IU/kg IV, q12h 7 doses; gentamicin 10 mg/kg IV q24h 4 doses n = 4, or q12-24 h 5 doses because of an additional erroneous dose, n = 2). Daily neurological examinations were video recorded, and ataxia graded by 3 observers. Urine status, urinary GGT/creatinine ratio, plasma creatinine, and urea were assessed every other day, EMG daily. Mixed model analysis was used to evaluate factors associated with ataxia grade and [PolyB].

RESULTS

Median ataxia score increased from 0/5 (range 0-2/5) to 2/5 (range 1-3/5) during administration and declined to 0.5/5 (range 0-2/5) after cessation. Gentamicin co-administration (P < .01, effect size: .8), number of PolyB doses (P < .001, effect size: .6), and time since last PolyB dose (P < .001, effect size: .5) had a significant effect on ataxia grades, while horse, day, [Genta], [PolyB], and [PolyB]CSF did not. Gentamicin co-administration and [Genta] Cpeak had no effect on median [PolyB] Cpeak (4.67 and 4.89 μg/ml for PolyB and PolyB/gentamicin, respectively). Urinary GGT/creatinine ratio was elevated in 3/6 horses receiving PolyB/gentamicin. The EMG remained unchanged.

CONCLUSIONS AND CLINICAL IMPORTANCE

PolyB caused transient ataxia, worsening with cumulative PolyB doses and gentamicin co-administration. Nephrotoxicity of PolyB was only evident when gentamicin was co-administered.

Diagnosis of post-attenuation neurological signs syndrome in a cat with refractory status epilepticus and clinical response to therapeutic plasma exchange

Case summary

An 8-year-old female spayed British Shorthair cat that underwent surgical portosystemic shunt (PSS) attenuation developed progressive neurological signs 7 days postoperatively. Neurological signs progressed, despite medical management, and seizure activity became rapidly refractory to anticonvulsants. The diagnosis of post-attenuation neurological signs (PANS) was made based on the timing of the occurrence of clinical signs following surgery, absence of hyperammonaemia and suggestive MRI findings of the brain. The cat developed status epilepticus that required treatment with general anaesthesia and mechanical ventilation, from which the cat could not be effectively weaned without the recurrence of seizures. Therapeutic plasma exchange (TPE) was performed as a rescue therapy for PANS and associated refractory status epilepticus. A total of two plasma volumes were processed during one single TPE session. The seizure activity resolved immediately after the TPE session, the cat showed progressive improvement of neurological signs and remained stable thereafter. No significant complications associated with the TPE were observed. The cat was discharged 11 days after admission and was fully recovered.

Relevance and novel information

This is an unusual report of PANS diagnosed in a cat based on clinical and MRI findings. The cat developed refractory status epilepticus and had a positive outcome following TPE as rescue therapy. The MRI findings in this report could be useful for the diagnosis of PANS in cats. We speculate that TPE could be taken into consideration as a possible therapeutic intervention in PANS syndrome.

Treatment of intracranial neoplasia in dogs using higher doses: A randomized controlled trial comparing a boosted to a conventional radiation protocol

BACKGROUND

Local progression of intracranial tumors can be the consequence of insufficient radiation dose delivered. Dose increases in the brain must be made carefully so as not to risk debilitating adverse effects such as radiation necrosis.

HYPOTHESIS

A new protocol with 10 × 4 Gy + 11% physical dose increase limited to the macroscopic tumor volume results in a clinically better outcome compared to a 10 × 4 Gy protocol.

ANIMALS

Fifty-seven client-owned dogs with primary intracranial neoplasia.

METHODS

Randomized controlled trial. Twenty-eight dogs were assigned to the control protocol (10 × 4 Gy) and 29 to the simultaneous integrated boost (SIB) protocol with 4.45 Gy dose increase. Treatment groups were compared for outcome and signs of toxicity.

RESULTS

Mild, transient acute or early-delayed adverse radiation effects were observed in 5 dogs. Severe late adverse effects were not seen. Between the protocols, no significant differences were found for outcome (intention-to-treat analysis): overall time to progression (TTP) was 708 days (95% confidence interval (95% CI) [545,872]), in the control group it was 828 days (95% CI [401,1256]), and in the SIB group 627 days (95% CI [282,973]; P = .07). Median overall survival (OS) was 684 days (95% CI [516,853]), in the control group it was 724 days (95% CI [623,826]), and in the SIB group 557 days (95% CI [95,1020]; P = .47). None of the tested variables was prognostic in terms of outcome.

CONCLUSION AND CLINICAL IMPORTANCE

The dose escalation used with an 11% physical dose increase did not result in better outcome.

Mapping‑by‑Sequencing Reveals Genomic Regions Associated with Seed Quality Parameters in Brassica napus

Rapeseed (Brassica napus L.) is an important oil crop and has the potential to serve as a highly productive source of protein. This protein exhibits an excellent amino acid composition and has high nutritional value for humans. Seed protein content (SPC) and seed oil content (SOC) are two complex quantitative and polygenic traits which are negatively correlated and assumed to be controlled by additive and epistatic effects. A reduction in seed glucosinolate (GSL) content is desired as GSLs cause a stringent and bitter taste. The goal here was the identification of genomic intervals relevant for seed GSL content and SPC/SOC. Mapping by sequencing (MBS) revealed 30 and 15 new and known genomic intervals associated with seed GSL content and SPC/SOC, respectively. Within these intervals, we identified known but also so far unknown putatively causal genes and sequence variants. A 4 bp insertion in the MYB28 homolog on C09 shows a significant association with a reduction in seed GSL content. This study provides insights into the genetic architecture and potential mechanisms underlying seed quality traits, which will enhance future breeding approaches in B. napus.

Reversible facial nerve paralysis in a cat suspected to be associated with systemic hypertension

Case summary

This report describes the appearance of facial nerve paralysis in a 16-year-old hypertensive cat. MRI was helpful in visualising and characterising mesencephalic and facial nerve lesions thought to be induced by hypertension. Neurological signs rapidly resolved under antihypertensive therapy.

Relevance and novel information

Systemic hypertension is an important medical condition in geriatric cats causing damage in various target organs, including the brain. Hypertensive encephalopathy is an umbrella term for a multitude of different clinical manifestations of cerebral target organ damage. Facial nerve paralysis secondary to hypertension is recognised in human medicine, particularly in children, but so far has not been reported in veterinary medicine.

Canine Tick-Borne Encephalitis: Clinical Features, Survival Rate and Neurological Sequelae: A Retrospective Study of 54 Cases (1999-2016)

Tick-borne encephalitis (TBE) is one of the most important infectious diseases of the central nervous system in dogs from endemic areas. While in humans survival rate and long-term outcomes are well described, these data are lacking in veterinary literature. The aim of the present paper is to characterize the clinical aspects of TBE and to investigate fatality rate, long-term outcome and the long-term neurological sequelae in a population of dogs infected with TBE. We performed a retrospective analysis of 54 dogs diagnosed with TBE at the veterinary hospital of the University of Zurich between 1999 and 2016. Medical data such as signalment, clinical presentation, results of diagnostic procedures, treatment and outcome were collected and analyzed. Statistical analysis including a cox proportional hazard model using a backward stepwise regression approach was performed. In 62% of the TBE cases unspecific signs were described before the onset of neurological signs, resembling a biphasic appearance that is well known in human TBE. Case fatality rate was 33% and all dogs died within the first 4 months after diagnosis. Long-term neurological sequalae were detected in 17% of the TBE cases. For each day of clinical signs before hospital entry the odds of sequalae increased by a factor of 1.88 (CI 1.04–3.15). Older dogs and dogs presented with seizure activity had an increased hazard risk of death (Hazard ration = 1.2, p = 0.03; and 9.38, p = 0.001, respectively). In conclusion, despite TBE being a life-threatening disease with severe clinical signs, the survival rate in our study was 67%. However, long-term sequalae can be of concern especially in dogs with longer clinical course.

Phase III double-blind study comparing the efficacy and safety of proposed biosimilar MYL-1402O and reference bevacizumab in stage IV non-small-cell lung cancer

Purpose:

This phase III study compared the efficacy and safety of proposed biosimilar MYL-1402O with reference bevacizumab (BEV), as first-line treatment for patients with stage IV non-squamous non-small-cell lung cancer.

Patients and methods:

Patients were randomly assigned (1:1) to receive MYL-1402O or bevacizumab with carboplatin-paclitaxel up to 18 weeks (6 cycles), followed by up to 24 weeks (8 cycles) of bevacizumab monotherapy. The primary objective was comparison of overall response rate (ORR), based on independently reviewed best tumor responses as assessed during the first 18 weeks. ORR was analyzed per US Food and Drug Administration (ratio of ORR) and European Medicines Agency (difference in ORRs) requirements for equivalence evaluation. Secondary end points included progression-free survival, disease control rate, duration of response, overall survival, safety, and immunogenicity over a period of 42 weeks, and pharmacokinetics (up to 18 weeks).

Results:

A total of 671 patients were included in the intent-to-treat population. The ratio of ORR was 0.96 [confidence interval (CI) 0.83, 1.12] and the difference in ORR was −1.6 (CI −9.0, 5.9) between treatment arms; CIs were within the predefined equivalence margins. Overall, the incidence of treatment-emergent adverse events and serious adverse events was comparable. Treatment-emergent anti-drug antibody (ADA) positivity was transient, with no notable differences between treatment arms (6.5% versus 4.8% ADA positivity rate in MYL-1402O versus BEV, respectively). The incidence of neutralizing antibody post-baseline was lower in the MYL-1402O arm (0.6%) compared to the bevacizumab arm (2.5%).

Conclusions:

MYL-1402O is therapeutically equivalent to bevacizumab, based on the ORR analyses, with comparable secondary endpoints.

Trial Registry Information

EU Clinical Trials Register, Registration # EudraCT no. 2015-005141-32https://www.clinicaltrialsregister.eu/ctr-search/search?query=2015-005141-32

Plain language summary

Previous studies established bioequivalence of the proposed bevacizumab biosimilar MYL-1402O to reference bevacizumab. In this randomized, double-blind, phase III trial, MYL-1402O (n = 337) demonstrated comparable efficacy to bevacizumab (n = 334) in treating advanced non-squamous non-small-cell lung cancer per Food and Drug Administration and European Medicines Agency requirements for equivalence; the ratio of objective response rate (ORR) was 0.96 [90% confidence interval (CI) 0.83, 1.12] and the difference in ORR (MYL-1402O:bevacizumab) was −1.6 (95% CI −9.0, 5.9). Median progression-free survival at 42 weeks was comparable: 7.6 (7.0, 9.5) with MYL-1402O versus 9.0 (7.2, 9.7) months (p = 0.0906) with bevacizumab, by independent review. Treatment-emergent adverse events leading to death (2.4% vs 1.5%), serious adverse events (17.6% vs 16.7%), and antidrug antibodies (6.5% vs 4.8%), were comparable in the MYL-1402O vs bevacizumab arms, respectively. The incidence of neutralizing antibody post-baseline was lower with MYL-1402O (0.6%) than with bevacizumab (2.5%). These findings confirm therapeutic equivalence of MYL-1402O to bevacizumab, providing opportunities for improving access to bevacizumab.

Canine presumed glial brain tumours treated with radiotherapy: Is there an inferior outcome in tumours contacting the subventricular zone?

Post-treatment outcome in canine glial tumours is described with a broad range of survival times between 2 and 28 months. After surgery or radiation therapy, the tumours may progress locally or spread within the central nervous system. It is unknown if tumour- or patient-specific factors influence prognosis. In humans, glioblastoma involving the subventricular zone has been found to recur distantly, with shortened time to progression and overall survival. We included 32 dogs irradiated for a presumptive primary glial brain tumour in this retrospective cohort study. Tumours were grouped relative to subventricular zone contact and overt ventricular invasion assessing pre-treatment magnetic resonance images. Median time to progression (TTP) for all cases was 534 days (95%CI, 310-758), with a significantly shorter TTP in dogs with lesions at the subventricular zone (median TTP, 260 vs. 687 days; p = .049). Tumours at the subventricular zone progressed more often (p = .001), and more likely as CNS-metastasis (52.9% vs. 13.3%, p = .028). Median overall survival (OS) was 489 days (95%CI, 147-831) and median tumour-specific survival 609 days (95%CI, 382-835). Involvement of the subventricular zone was significantly associated with a shorter tumour-specific survival (median, 306 vs. 719 days; p = .044). Glial tumours contacting the subventricular zone in dogs have a shorter tumour-specific survival and a higher rate of progression and CNS-metastasis. Despite local tumour control, metastasis must be considered and should prompt further treatment approaches.

Evaluating the use of cytosine arabinoside for treatment for recurrent canine steroid-responsive meningitis-arteritis

Background

Relapses in steroid-responsive meningitis-arteritis (SRMA) are frequently observed but specific treatment protocols to address this problem are sparsely reported. Standard treatment includes prolonged administration of glucocorticoids as monotherapy or in combination with immunosuppressive drugs. The aim of this study was to assess the safety and efficacy of cytosine arabinoside (CA) in combination with glucocorticoids for treatment of SRMA relapses in 12 dogs on a retrospective basis.

Methods

Dogs with recurrent episodes of SRMA and treated with a combination of CA and prednisolone were included. Information about clinical course, treatment response and adverse events was collected from medical records. Ethical approval was not required for this study.

Results

Ten dogs (10/12) responded well to the treatment with clinical signs being completely controlled. One dog is in clinical remission, but still under treatment. One dog (8%) showed further relapse. Mean treatment period was 51 weeks. Adverse events of variable severity (grade 1–4/5) were documented in all dogs during treatment according to the veterinary cooperative oncology group grading. Three dogs developed severe adverse events. Laboratory findings showed marked changes up to grade 4. Diarrhoea and anaemia were the most often observed adverse events (6), followed by dermatitis (4), alopecia (3) and pneumonia (3). Including blood chemistry changes (13), 50 adverse events were found in total.

Conclusion

Treatment with CA and glucocorticoids resulted in clinical remission in 10/12 dogs, but a high incidence of adverse events occurred requiring additional measures. All adverse events could be managed successfully in all cases.

[Clinical characteristics of Idiopathic Epilepsy in Greater Swiss Mountain Dogs in Switzerland]

INTRODUCTION

Background: Little is known about idiopathic Epilepsy in Greater Swiss Mountain Dogs. Until now this breed is not listed as a predisposed breed for idiopathic epilepsy. The aim of this study was to estimate the prevalence of idiopathic epilepsy in Greater Swiss Mountain Dogs in Switzerland and to describe the clinical characteristics of epilepsy in this breed including seizures semiology and response to treatment. Material and Methods: Records of the Swiss Kennel Club for Greater Swiss Mountain Dogs were searched for reported cases of epileptic seizures between 1999-2019. The total number of reported cases and the signalment was reviewed. Furthermore, all owners of Greater Swiss Mountain Dogs registered to the breeding club were invited to complete an online questionnaire. Results: In total 600 Greater Swiss Mountain Dog's live in Switzerland: 70-90 puppies are born each year. Between 1999 and 2019 34 dogs (2%) were announced with seizures. Of the 400 owners invited to answer the questionnaire 128 completed the questionnaire. 20 of these 128 dogs were suffering from idiopathic epilepsy. The prevalence for idiopathic epilepsy based on the questionnaire was therefore 15,6%. All affected dogs showed generalized tonic-clonic seizures. Cluster seizures and status epilepticus occurred in 5 (41,6%) and 6 (50%) of the dogs. Long term seizure control was only achieved in 10% of the dogs. Five dogs (25%) died or were euthanized because of insufficient seizure control. Only one dog (5%) showed clinical remission. Conclusion: Prevalence of idiopathic epilepsy is higher in Greater Swiss Mountain Dogs in Switzerland compared to the general dog population. Seizure control seems to be difficult to achieve in this breed and remission-rate is low.

Adjuvant therapy following oesophagectomy for adenocarcinoma in patients with a positive resection margin

BACKGROUND

The role of adjuvant therapy in patients with oesophagogastric adenocarcinoma treated by neoadjuvant chemotherapy is contentious. In UK practice, surgical resection margin status is often used to classify patients for receiving adjuvant treatment. The aim of this study was to assess the survival benefit of adjuvant therapy in patients with positive (R1) resection margins.

METHODS

Two prospectively collected UK institutional databases were combined to identify eligible patients. Adjusted Cox regression analyses were used to compare overall and recurrence-free survival according to adjuvant treatment. Recurrence patterns were assessed as a secondary outcome. Propensity score-matched analysis was also performed.

RESULTS

Of 616 patients included in the combined database, 242 patients who had an R1 resection were included in the study. Of these, 112 patients (46·3 per cent) received adjuvant chemoradiotherapy, 46 (19·0 per cent) were treated with adjuvant chemotherapy and 84 (34·7 per cent) had no adjuvant treatment. In adjusted analysis, adjuvant chemoradiotherapy improved recurrence-free survival (hazard ratio (HR) 0·59, 95 per cent c.i. 0·38 to 0·94; P = 0·026), with a benefit in terms of both local (HR 0·48, 0·24 to 0·99; P = 0·047) and systemic (HR 0·56, 0·33 to 0·94; P = 0·027) recurrence. In analyses stratified by tumour response to neoadjuvant chemotherapy, non-responders (Mandard tumour regression grade 4-5) treated with adjuvant chemoradiotherapy had an overall survival benefit (HR 0·61, 0·38 to 0·97; P = 0·037). In propensity score-matched analysis, an overall survival benefit (HR 0·62, 0·39 to 0·98; P = 0·042) and recurrence-free survival benefit (HR 0·51, 0·30 to 0·87; P = 0·004) were observed for adjuvant chemoradiotherapy versus no adjuvant treatment.

CONCLUSION

Adjuvant therapy may improve overall survival and recurrence-free survival after margin-positive resection. This pattern seems most pronounced with adjuvant chemoradiotherapy in non-responders to neoadjuvant chemotherapy.

Striate Artery Infarct After Bilateral Carotid Artery Ligation (BCAL) in a Dog: A Multimodal MRI Study

Bilateral carotid artery ligation has been reported as a lifesaving procedure to control severe hemorrhage. However, reports are sparse and little information is available regarding the potential risks associated with this procedure. We report an ischemic brain infarct as a complication after vascular surgery. A 3-year old, male intact border collie was presented for acute onset of forebrain signs 5 days after bilateral carotid artery ligation. Multimodal brain MRI including morphologic sequences, MR angiography, diffusion- and perfusion-weighted images were performed. MRI revealed a well-defined intra-axial lesion of the left caudate nucleus, with increased T2 and decreased T1 signal intensity and moderate heterogeneous peripheral contrast enhancement. The cerebral blood flow was reduced relative to the contralateral caudate nucleus. Images were consistent with a subacute lacunar ischemic infarct of the left striate artery. Additionally, multiple arterio-arterial anastomosis arising from the vertebral arteries were visible in the angiography sequences. Ischemic infarct due to thromboembolism should be considered as a possible complication associated with bilateral carotid artery ligation. Collateral blood supply can develop as early as 5 days after surgery.

Brain proton magnetic resonance spectroscopy findings in a Beagle dog with genetically confirmed Lafora disease

Cortical atrophy has been identified using magnetic resonance imaging (MRI) in humans and dogs with Lafora disease (LD). In humans, proton magnetic resonance spectroscopy (1HMRS) of the brain indicates decreased N‐acetyl‐aspartate (NAA) relative to other brain metabolites. Brain 1HMRS findings in dogs with LD are lacking. A 6‐year‐old female Beagle was presented with a history of a single generalized tonic‐clonic seizure and episodic reflex myoclonus. Clinical, hematological, and neurological examination findings and 3‐Tesla MRI of the brain were unremarkable. Brain 1HMRS with voxel positioning in the thalamus was performed in the affected Beagle. It identified decreased amounts of NAA, glutamate‐glutamine complex, and increased total choline and phosphoethanolamine relative to water and total creatine compared with the reference range in healthy control Beagles. A subsequent genetic test confirmed LD. Abnormalities in 1HMRS despite lack of changes with conventional MRI were identified in a dog with LD.

Conventional and functional magnetic resonance imaging features of late subacute cortical laminar necrosis in a dog

Cerebral cortical laminar necrosis (CLN) is a consequence of severe hypoxic, ischemic, or hypoglycemic events. In humans, these cortical lesions show characteristic linear T1‐weighted (T1W) hyperintensity in the late subacute stage. Limited information reporting magnetic resonance imaging (MRI) findings in dogs affected by CLN is available. A 3‐year‐old Belgian Shepherd dog was referred 8 days after sudden onset of blindness after general anesthesia. Neurological examination showed central blindness and mild ataxia. Three‐Tesla MRI examination of the brain revealed bilateral asymmetrical areas of T2‐weighted hyperintensity within the occipital, parietal, temporal, and frontal cortex, involving gray and white matter. Furthermore, linear T1W‐hyperintense lesions were found in the cerebral cortex of the same areas and showed heterogeneous contrast enhancement. Perfusion‐weighted images revealed hyperperfusion in the affected regions. Lesions were compatible with subacute CLN with corresponding edema suspected to be secondary to anesthesia‐related brain hypoxia. Three‐Tesla MRI enabled identification of the laminar pattern of the cortical lesions.

Randomized phase 3 efficacy and safety trial of proposed pegfilgrastim biosimilar MYL-1401H in the prophylactic treatment of chemotherapy-induced neutropenia

Pegfilgrastim is indicated for reducing the duration of neutropenia and incidence of febrile neutropenia in patients receiving cytotoxic chemotherapy. Here, safety and efficacy of MYL-1401H, a proposed pegfilgrastim biosimilar, were investigated as prophylaxis for chemotherapy-induced neutropenia. This was a phase 3, multicenter, randomized, double-blind, parallel-group equivalence trial of MYL-1401H vs European Union–sourced reference pegfilgrastim. Patients with newly diagnosed stage II/III breast cancer eligible to receive (neo) adjuvant chemotherapy with docetaxel/doxorubicin/cyclophosphamide every 3 weeks for 6 cycles were enrolled and randomized 2:1 to 6 mg of MYL-1401H or reference pegfilgrastim 24 h (+ 2-h window after the first 24 h) after the end of chemotherapy. The primary efficacy endpoint was the duration of severe neutropenia in cycle 1 (i.e., days with absolute neutrophil count (ANC) < 0.5 × 10⁹/L). Mean (standard deviation (SD)) duration of severe neutropenia in MYL-1401H and reference pegfilgrastim groups was 1.2 days (0.93) and 1.2 days (1.10), respectively. The 95% CI for least squares mean difference (− 0.285, 0.298) was within the predefined equivalence range of ± 1 day. Secondary endpoints, including grade ≥ 3 neutropenia (frequency, 91% and 82% for MYL-1401H and reference pegfilgrastim, respectively), time to ANC nadir (mean (SD), 6.2 (0.98) and 6.3 (1.57) days), and duration of post-nadir recovery (mean (SD), 1.9 (0.85) and 1.7 (0.91) days) were comparable. Overall safety profiles of the study drugs were comparable. MYL-1401H demonstrated equivalent efficacy and similar safety to reference pegfilgrastim and may be an equivalent option for reducing incidence of neutropenia. (ClinicalTrials.gov, NCT02467868; EudraCT, 2014-002324-27).

Comparative evaluation of a novel, moderately hypofractionated radiation protocol in 56 dogs with symptomatic intracranial neoplasia

Background: Use of strongly hypofractionated radiation treatments in dogs with intracranial neoplasia did not improve outcomes and yielded increased rates of toxicosis.

Objectives: To evaluate safety and efficacy of a new, moderately hypofractionated radiation protocol of 10 × 4 Gy compared to a standard protocol.

Animals: Convenience sample of 56 client‐owned dogs with primary symptomatic brain tumors.

Methods: Retrospective observational study. Twenty‐six dogs were assigned to the control standard protocol of 20 × 2.5 Gy (group A) and 30 dogs to the new protocol of 10 × 4 Gy (group B), assigned on owners' informed consent. Statistical analysis was conducted under the “as treated” regime, using Kaplan‐Meier and Cox‐regression analysis. Treatment was delivered with technically advanced image‐guided radiation therapy. The 2 treatment groups were compared in terms of outcome and signs of toxicosis.

Results: Overall progression‐free interval (PFI) and overall survival (OS) time were favorable, with 663 (95%CI: 497;828) and 637 (95%CI: 403;870) days, respectively. We found no significant difference between the two groups: PFI for dogs in group A vs B was 608 (95%CI: 437;779) days and mean (median not reached) 863 (95%CI: 644;1083) days, respectively (P = .89), and OS for dogs in group A vs B 610 (95%CI: 404;816) and mean (median not reached) 796 (95%CI: 586;1007) days (P = .83).

Conclusion and Clinical Importance: In conclusion, 10 × 4 Gy is a safe and efficient protocol for treatment of primary intracranial neoplasia and future dose escalation can be considered.

Recurrent cerebrovascular accidents caused by intravascular lymphoma in a dog

An eight-year-old, neutered male labrador was presented with recent recurrent vestibular episodes. MRI was consistent with multiple lacunar ischaemic infarcts in the thalamus and medulla oblongata. The imaging diagnosis was supported by a markedly elevated D-dimer concentration. Despite a comprehensive diagnostic workup (including fine needle cytology of cutaneous and subcutaneous nodules, complete bloodwork, urinalysis, thoracic and abdominal imaging, cerebrospinal fluid analysis, serial blood pressure measurements, echocardiography, electrocardiography and brainstem auditory evoked response testing), no underlying cause was found. After a partial response to 2  mg/kg clopidogrel once a day and 1  mg/kg prednisolone once a day, the dog acutely deteriorated and repeated MRI of the brain revealed an intra-axial haemorrhagic mass. Euthanasia was elected and postmortem examination revealed the presence of an intravascular null-cell lymphoma, exclusively in the central nervous system. Intravascular lymphoma is rare, difficult to diagnose ante-mortem and reports in veterinary literature are few.

Assessing impact of organised breast screening across small residential areas-development and internal validation of a prediction model

Monitoring screening mammography effects in small areas is often limited by small numbers of deaths and delayed effects. We developed a risk score for breast cancer death to circumvent these limitations. Screening, if effective, would increase post-diagnostic survivals through lead-time and related effects, as well as mortality reductions. Linked cancer and BreastScreen data at four hospitals (n = 2,039) were used to investigate whether screened cases had higher recorded survivals in 13 small areas, using breast cancer deaths as the outcome (M1), and a risk of death score derived from TNM stage, grade, histology type, hormone receptor status, and related variables (M2). M1 indicated lower risk of death in screened cases in 12 of the 13 areas, achieving statistical significance (p < .05) in 5. M2 indicated lower risk scores in screened cases in all 13 areas, achieving statistical significance in 12. For cases recently screened at diagnosis (<6 months), statistically significant reductions applied in 8 areas (M1) and all 13 areas (M2). Screening effects are more detectable in small areas using these risk scores than death itself as the outcome variable. An added advantage is the application of risk scores for providing a marker of screening effect soon after diagnosis.

Using Qualitative Disease Risk Analysis for Herpetofauna Conservation Translocations Transgressing Ecological and Geographical Barriers

Through the exploration of disease risk analysis methods employed for four different UK herpetofauna translocations, we illustrate how disease hazards can be identified, and how the risk of disease can be analysed. Where ecological or geographical barriers between source and destination sites exist, parasite populations are likely to differ in identity or strain between the two sites, elevating the risk from disease and increasing the number and category of hazards requiring analysis. Simplification of the translocation pathway through the avoidance of these barriers reduces the risk from disease. The disease risk analysis tool is intended to aid conservation practitioners in decision making relating to disease hazards prior to implementation of a translocation.

Unexplained bleeding as primary clinical complaint in dogs infected with Angiostrongylus vasorum

INTRODUCTION

Unexplained bleeding was the primary clinical complaint in 15 dogs diagnosed with A. vasorum and was observed in the mouth, as external bleeding, as large subcutaneous hematoma, as hemoptysis, in the brain, post ovariectomy, as epistaxis, in the anterior ocular chamber and on a tracheal intubation tube. In 8 dogs the cause of bleeding initially was suspected to be a minor trauma or a surgical complication, and various surgical approaches had been undertaken to eliminate the problem. In only 3 dogs respiratory signs were observed before the bleeding prompted referral. The median time elapsed between the first recognized clinical signs attributed to A. vasorum until diagnosis was 2 weeks (range1 day to 4 months). Four dogs died, 3 on the day of admission and 1 dog 4 days after admission. Suspected causes of death were respiratory failure and cerebral hemorrhage in 2 dogs each. Four dogs had been pre-treated with NSAIDs; of these, 2 dogs developed severe hemoptysis (1 died), 1 dog developed brain hemorrhage (and died), and 1 dog developed a large subcutaneous hematoma with marked anemia. Bleeding at various sites may be the only recognized abnormality in A. vasorum infection. Without a high index of suspicion, the diagnosis and appropriate therapy may be delayed to the point of a fatal outcome. Tests of coagulation were quite variable and the cause of bleeding likely multifactorial.

COMPARISON BETWEEN PROTON MAGNETIC RESONANCE SPECTROSCOPY FINDINGS IN DOGS WITH TICK-BORNE ENCEPHALITIS AND CLINICALLY NORMAL DOGS

In vivo diagnosis of tick-borne encephalitis is difficult due to high seroprevalence and rapid viral clearance, limiting detection of antibodies in blood and cerebrospinal fluid. Magnetic resonance imaging (MRI) characteristics of tick-borne encephalitis have been reported, however MRI studies can also be negative despite the presence of neurologic signs. Magnetic resonance spectroscopy (¹ H MRS) is an imaging method that provides additional information about the metabolic characteristics of brain tissues. The purpose of this retrospective cross-sectional study was to describe brain metabolites using short echo time single-voxel ¹ H MRS in dogs with confirmed tick-borne encephalitis and compare them with healthy dogs. Inclusion criteria for the affected dogs were neurological symptoms suggestive of tick-borne encephalitis, previous endemic stay and tick-bite, diagnostic quality brain MRI and ¹ H MRS studies, and positive antibody titers or confirmation of tick-borne encephalitis with necropsy. Control dogs were 10, clinically normal beagles that had been used in a previous study. A total of six affected dogs met inclusion criteria. All dogs affected with tick-borne encephalitis had ¹ H MRS metabolite concentration alterations versus control dogs. These changes included mild to moderate decreases in N-acetyl aspartate and creatine peaks, and mild increases in glutamate/glutamine peaks. No lactate or lipid signal was detected in any dog. Myoinositol and choline signals did not differ between affected and control dogs. In conclusion, findings supported the use of ¹ H MRS as an adjunctive imaging method for dogs with suspected tick-borne encephalitis and inconclusive conventional MRI findings.

The role of nano-sized manganese oxides in the oxygen-evolution reactions by manganese complexes: towards a complete picture

Eighteen Mn complexes with N-donor and carboxylate ligands have been synthesized and characterized. Three Mn complexes among them are new and are reported for the first time. The reactions of oxygen evolution in the presence of oxone (2KHSO5·KHSO4·K2SO4) and cerium(iv) ammonium nitrate catalyzed by these complexes are studied and characterized by UV-visible spectroscopy, X-ray diffraction spectrometry, dynamic light scattering, Fourier transform infrared spectroscopy, electron paramagnetic resonance spectroscopy, transmission electron microscopy, scanning electron microscopy, membrane-inlet mass spectrometry and electrochemistry. Some of these complexes evolve oxygen in the presence of oxone as a primary oxidant. CO2 and MnO4(-) are other products of these reactions. Based on spectroscopic studies, the true catalysts for oxygen evolution in these reactions are different. We proposed that for the oxygen evolution reactions in the presence of oxone, the true catalysts are both high valent Mn complexes and Mn oxides, but for the reactions in the presence of cerium(iv) ammonium nitrate, the active catalyst is most probably a Mn oxide.

A newly designed radiation therapy protocol in combination with prednisolone as treatment for meningoencephalitis of unknown origin in dogs: a prospective pilot study introducing magnetic resonance spectroscopy as monitor tool

Background

A plethora of treatment options have been described for canine meningoencephalitis of unknown origin (MUO), yet a gold standard has not been established. The aim of this prospective pilot study was to document the effect of a newly designed 30 Gray (Gy) radiation therapy (RT) protocol plus corticosteroids as treatment for focal and multifocal MUO, to monitor clinical and imaging changes during the course of the disease with conventional magnetic resonance imaging (MRI) and proton MR Spectroscopy (H-1 MRS) and to detect the occurrence of radiation related side effects.

Results

Six dogs (3 with focal and 3 with multifocal lesions) were included in the study. The RT protocol used consisted of 30 Gy in 10 fractions. The neurological status of all six dogs improved during RT, with 3 of 6 cases returning to a normal condition. One dog was euthanized early during follow-up (<3 weeks after end of RT). Three month follow up MRI was normal in one dog and improved in 3 dogs and H-1 MRS normalized in 4. In the dog without improvement of the MRI lesions, the N-acetyl aspartate continued to decrease, while choline and creatine concentrations remained stable during that time. This dog was euthanized 18 month after the end of RT due to relapse. One dog was lost to follow up 12 month after completion of RT. The other 3 dogs are still alive at the time of writing.

Conclusions

RT with 30 Gy in 10 fractions can provide an additional option for anti-inflammatory treatment of focal and multifocal MUO. The protocol used for treatment monitoring was feasible while no side effects of RT could be observed during the follow up period. Moreover, H-1 MRS could represent a new and non-invasive tool to control the progression of the disease during the treatment course.

Pharmacokinetic interaction between simvastatin and fenofibrate with staggered and simultaneous dosing: Does it matter?

Simvastatin and fenofibrate are frequently co-prescribed at staggered intervals for the treatment of dyslipidemia. Since a drug-drug interaction has been reported when the two drugs are given simultaneously, it is of clinical interest to know whether the interaction differs between simultaneous and staggered combinations. A study, assessing the impact of both combinations on the interaction, was conducted with 7-day treatment regimens using simvastatin 40 mg and fenofibrate 145 mg: (A) simvastatin only (evening), (B) simvastatin and fenofibrate (both in evening), and (C) simvastatin (evening) and fenofibrate (morning). Eighty-five healthy subjects received the respective treatments in a randomized, 3-way cross-over study. The pharmacokinetics of simvastatin and the active metabolite simvastatin acid were determined. There was a limited reduction in the AUC0-24h of simvastatin acid of 21 and 29% for simultaneous and staggered combination, respectively. The geometric mean AUC0-24h ratio of simvastatin acid for the two combined dosing regimens (B/C) and 90% confidence interval were 111% (102-121). The interaction apparently had no impact on lipid markers. The findings imply that the observed pharmacokinetic interaction is unlikely clinically relevant, and support the combined use of simvastatin and fenofibrate not only given at staggered interval but also given simultaneously.

Anammox moving bed biofilm reactor pilot at the 26th Ward wastewater treatment plants in Brooklyn, New York: start-up, biofilm population diversity and performance optimization

New York City Environmental Protection in conjunction with City College of New York assessed the application of the anammox process in the reject water treatment using a moving bed biofilm reactor (MBBR) located at the 26th Ward wastewater treatment plant, in Brooklyn, NY. The single-stage nitritation/anammox MBBR was seeded with activated sludge and consequently was enriched with its own 'homegrown' anammox bacteria (AMX). Objectives of this study included collection of additional process kinetic and operating data and assessment of the effect of nitrogen loading rates on process performance. The initial target total inorganic nitrogen removal of 70% was limited by the low alkalinity concentration available in the influent reject water. Higher removals were achieved after supplementing the alkalinity by adding sodium hydroxide. Throughout startup and process optimization, quantitative real-time polymerase chain reaction (qPCR) analyses were used for monitoring the relevant species enriched in the biofilm and in the suspension. Maximum nitrogen removal rate was achieved by stimulating the growth of a thick biofilm on the carriers, and controlling the concentration of dissolved oxygen in the bulk flow and the nitrogen loading rates per surface area; all three appear to have contributed in suppressing nitrite-oxidizing bacteria activity while enriching AMX density within the biofilm.