Expanding the phenotype in argininosuccinic aciduria: need for new therapies

Objectives

This UK-wide study defines the natural history of argininosuccinic aciduria and compares long-term neurological outcomes in patients presenting clinically or treated prospectively from birth with ammonia-lowering drugs.

Methods

Retrospective analysis of medical records prior to March 2013, then prospective analysis until December 2015. Blinded review of brain MRIs. ASL genotyping.

Results

Fifty-six patients were defined as early-onset (n?=?23) if symptomatic?<?28 days of age, late-onset (n?=?23) if symptomatic later, or selectively screened perinatally due to a familial proband (n?=?10). The median follow-up was 12.4 years (range 0–53). Long-term outcomes in all groups showed a similar neurological phenotype including developmental delay (48/52), epilepsy (24/52), ataxia (9/52), myopathy-like symptoms (6/52) and abnormal neuroimaging (12/21). Neuroimaging findings included parenchymal infarcts (4/21), focal white matter hyperintensity (4/21), cortical or cerebral atrophy (4/21), nodular heterotopia (2/21) and reduced creatine levels in white matter (4/4). 4/21 adult patients went to mainstream school without the need of additional educational support and 1/21 lives independently. Early-onset patients had more severe involvement of visceral organs including liver, kidney and gut. All early-onset and half of late-onset patients presented with hyperammonaemia. Screened patients had normal ammonia at birth and received treatment preventing severe hyperammonaemia. ASL was sequenced (n?=?19) and 20 mutations were found. Plasma argininosuccinate was higher in early-onset compared to late-onset patients.

Conclusions

Our study further defines the natural history of argininosuccinic aciduria and genotype–phenotype correlations. The neurological phenotype does not correlate with the severity of hyperammonaemia and plasma argininosuccinic acid levels. The disturbance in nitric oxide synthesis may be a contributor to the neurological disease. Clinical trials providing nitric oxide to the brain merit consideration.

     

Notch signaling in CD66+ cells drives the progression of human cervical cancers

Human epithelial tumor progression and metastasis involve cellular invasion, dissemination in the vasculature, and regrowth at metastatic sites. Notch signaling has been implicated in metastatic progression but its roles have yet to be fully understood. Here we report the important role of Notch signaling in maintaining cells expressing the carcinoembryonic antigen cell adhesion molecule CEACAM (CD66), a known mediator of metastasis. CD66 and Notch1 were studied in clinical specimens and explants of human cervical cancer, including specimens grown in a pathophysiologically relevant murine model. Gene expression profiling of CD66(+) cells from primary tumors showed enhanced features of Notch signaling, metastasis, and stemness. Significant differences were also seen in invasion, colony formation, and tumor forming efficiency between CD66(+) and CD66(-) cancer cells. Notably, CD66(+) cells showed a marked sensitivity to a Notch small molecule inhibitor. In support of studies in established cell lines, we documented the emergence of a tumorigenic CD66(+) cell subset within a metastatic lesion-derived cervical-cancer cell line. Similar to primary cancers, CD66 expression in the cell line was blocked by chemical and genetic inhibitors of ligand-dependent nuclear Notch signaling. Collectively, our work on the oncogenic properties of CD66(+) cells in epithelial cancers provides insights into the nature of tumor progression and offers a mechanistic rationale to inhibit the Notch signaling pathway as a generalized therapeutic strategy to treat metastatic cancers.     

In vivo pharmacology and toxicology evaluation of polyethylene glycol-conjugated interferon beta-1a

Human interferon (IFN) β has well established beneficial effects in treating relapsing forms of multiple sclerosis, but current first-line treatment requires frequent (from daily to weekly) parenteral administration. A 20-kDa polyethylene glycol (PEG)-conjugated IFN β-1a (PEG-IFN β-1a) is being developed to decrease the frequency of administration and improve patient convenience and compliance. We present pharmacokinetic (PK) and pharmacodynamic (PD) parameters, immunogenicity, and safety of PEG-IFN β-1a in Rhesus monkeys in support of a phase 1 clinical trial. Two single-dose PK/PD studies and one 5-week repeat-dose toxicity study compliant with good laboratory practice were conducted. The PK of IFN β-1a and PEG-IFN β-1a were modeled with a two-compartment model, and the link between drug concentration and neopterin response (PD marker) was described with an indirect stimulatory model. PEG-IFN β-1a showed greater exposure, longer half-life, lower clearance, and reduced volume of distribution than unmodified IFN β-1a. Consistent with the pharmacology of type I IFNs, PEG-IFN β-1a resulted in the elevation of neopterin concentration, a transient body temperature increase, and a reversible lymphocyte count decrease. As expected, neutralizing antibodies to PEG-IFN β-1a formed in almost all monkeys after 5 weeks of treatment, which resulted in significantly reduced drug exposure and abrogation of neopterin induction. There were no drug-related adverse effects at doses up to 100 μg/kg (11 MIU/kg) given subcutaneously or intramuscularly once weekly for 5 weeks. The no-observed-adverse-effect level was determined to be 100 μg/kg (11 MIU/kg), the highest dose tested.     

Anatomical dimensions of larynx, epiglottis and cricoid cartilage in foetuses and their relationship with crown rump length

Background  

Advances in perinatal care and increased use of diagnostic and interventional procedures on foetal airway demand a clear understanding of their normal anatomy and development. This study is aimed at determining the normal dimensions of larynx, cricoid cartilage and epiglottis and their correlation to age and crown rump length (CRL).     

Phage lysin to supplement phagebiotics to decontaminate processed sputum specimens

The overgrowth of normal flora escaping the action of sputum processing chemicals is the major problem in broth-based tuberculosis (TB) detection systems. The use of phages to control the overgrowth of normal flora in processed sputum samples has already been established. Phage lysin and its supplementation to phagebiotics for the effective control of normal flora in sputum specimens were evaluated. Crude lysin was prepared from phage host mixture using standard procedures. About 120 sputum samples processed with 4% NaOH were collected and used to evaluate the effect of lysin, phagebiotics and phagebiotics supplemented with lysin on the overgrowth of normal flora. The effect of phagebiotics and lysin on the growth and retrieval of Mycobacterium tuberculosis was studied by conventional methods and the luciferase reporter phage (LRP) assay. Lysin alone and phagebiotics supplemented with lysin arrested the growth of normal flora in a significantly greater number of samples than phagebiotics alone. Lysin and phagebiotics did not show any inhibitory activity on M. tuberculosis. The use of antibiotics can be replaced by lysin or phagebiotics supplemented with lysin to control the overgrowth of normal flora in processed sputum samples without hampering the viability of M. tuberculosis.     

Primary multicentric cutaneous epithelioid angiosarcoma

Cutaneous epithelioid angiosarcoma is a rare malignant vascular tumor, most commonly affecting elderly men, and is usually located on the extremities. We report a case of an 81-year-old lady who presented with two ulcerated plaques over the right temporal and parietal scalp of 1 year duration. The right submaxillary and submandibular lymph nodes were enlarged and tender. Computed tomography (CT) scan of the head showed soft tissue swelling over parietal and temporal areas and there was no intracranial extension. Ultrasonogram of the abdomen showed hyperechoic areas in liver suggestive of secondaries. Histopathology of the skin lesion showed the dermis and subcutis composed of clusters of atypical epithelioid cells with vesicular nuclei, prominent nucleoli and eosinophilic cytoplasm with increased mitotic figures. Immunohistochemical staining revealed CD-31, 33, 34 and vimentin positivity, while cytokeratin was negative confirming the diagnosis of epitheloid angiosarcoma. This case report highlights the unusual occurrence of multicentric epitheloid angiosarcoma on the scalp with secondaries in the liver.