Alkaline Phosphatase Replacement Therapy for Hypophosphatasia in Development and Practice.

Hypophosphatasia (HPP) is an inherited disorder that affects bone and tooth mineralization characterized by low serum alkaline phosphatase. HPP is caused by loss-of-function mutations in the ALPL gene encoding the protein, tissue-nonspecific alkaline phosphatase (TNSALP). TNSALP is expressed by mineralizing cells of the skeleton and dentition and is associated with the mineralization process. Generalized reduction of activity of the TNSALP leads to accumulation of its substrates, including inorganic pyrophosphate (PPi) that inhibits physiological mineralization. This leads to defective skeletal mineralization, with manifestations including rickets, osteomalacia, fractures, and bone pain, all of which can result in multi-systemic complications with significant morbidity, as well as mortality in severe cases. Dental manifestations are nearly universal among affected individuals and feature most prominently premature loss of deciduous teeth. Management of HPP has been limited to supportive care until the introduction of a TNSALP enzyme replacement therapy (ERT), asfotase alfa (AA). AA ERT has proven to be transformative, improving survival in severely affected infants and increasing overall quality of life in children and adults with HPP. This chapter provides an overview of TNSALP expression and functions, summarizes HPP clinical types and pathologies, discusses early attempts at therapies for HPP, summarizes development of HPP mouse models, reviews design and validation of AA ERT, and provides up-to-date accounts of AA ERT efficacy in clinical trials and case reports, including therapeutic response, adverse effects, limitations, and potential future directions in therapy.

Bone turnover markers in relation to vitamin D status and disease activity in adults with systemic lupus erythematosus.

OBJECTIVE: Patients with systemic lupus erythematosus (SLE) have altered bone metabolism and are at risk of osteoporosis. The aim of this study was to examine bone turnover markers in relation to vitamin D, disease activity, and clinical risk factors in patients with established SLE. METHODS: Clinical registry and biorepository data of 42 SLE patients were assessed. Serum samples were analyzed for osteocalcin as a marker of bone formation, C-terminal telopeptide of type 1 collagen (CTX) as a marker for bone resorption, and 25-hydroxy vitamin D. RESULTS: Patients with a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI) score of 3 or greater had a lower median osteocalcin level ( P = 0.02) and lower 25-hydroxy vitamin D levels ( P = 0.03) than those with a score of less than 3. No significant differences in bone turnover markers were observed between patients dichotomized into subgroups using a 25-hydroxy vitamin D cut-off of 30 ng/mL or by a daily prednisone dose greater than or 5 mg or less. Osteocalcin levels were negatively correlated with SLEDAI scores ( P = 0.034), and were positively correlated with the CTX index (a ratio of measured CTX value to the upper limit of the normal value for age and gender) ( P < 0.01). No association between the CTX index and SLEDAI scores was found. CONCLUSION: SLE disease activity may have direct effects on bone formation, but no effects on bone resorption in this cohort of established SLE patients, probably related to the inflammation-suppressing effects of glucocorticoids, thereby inhibiting cytokine-induced osteoclast activity. A fine balance exists between disease control and the use of glucocorticoids with regard to bone health.

Asfotase alfa treatment for 1 year in a 16 year-old male with severe childhood hypophosphatasia.

We describe the clinical outcome of asfotase alfa therapy in a 16-year-old boy with severe childhood hypophosphatasia (HPP), who began therapy at age 15 years. The patient was diagnosed with HPP at age 2 years when he presented with genu varum and premature loss of primary teeth. He had a history of multiple fractures requiring 16 orthopedic surgeries with rod and pin placement in his lower extremities. He had chronic skeletal pain and used cane to ambulate with great difficulty. His height Z score at age 15 years was - 5. He had severe scoliosis and deformity of both legs. Bone radiograph showed hypomineralization and characteristic "tongues" of radiolucency in the distal radius and ulna. His serum alkaline phosphatase level was stable, with elevated serum pyridoxal 5'-phosphate and urine phosphoethanolamine, consistent with HPP. He was started on asfotase alfa 2 mg/kg given subcutaneously thrice weekly. He had marked clinical improvement in mobility with no report of pain after 3 months of treatment. At 6 month, he walked without cane and participated in outdoor activities with peers. Bone radiograph at 6 months showed striking improvement in previous radiolucent areas. At 9 months, his annualized growth velocity was 9.5 cm/year, while growth velocity of arm span was 12 cm/year. However, at 12 months, he was noted to have worsening scoliosis from 60 degrees before therapy to 110 degrees, with a slight decrease in height, necessitating a spinal fusion surgery. In conclusion, treatment with asfotase alfa significantly improved physical function, pain, overall quality of life, and skeletal radiographic findings in this patient. Close monitoring for progression of scoliosis in adolescents with HPP treated with asfotase alfa is recommended.

DEEP BIOSPHERE. Exploring deep microbial life in coal-bearing sediment down to ~2.5 km below the ocean floor.

Microbial life inhabits deeply buried marine sediments, but the extent of this vast ecosystem remains poorly constrained. Here we provide evidence for the existence of microbial communities in ~40° to 60°C sediment associated with lignite coal beds at ~1.5 to 2.5 km below the seafloor in the Pacific Ocean off Japan. Microbial methanogenesis was indicated by the isotopic compositions of methane and carbon dioxide, biomarkers, cultivation data, and gas compositions. Concentrations of indigenous microbial cells below 1.5 km ranged from <10 to ~10(4) cells cm(-3). Peak concentrations occurred in lignite layers, where communities differed markedly from shallower subseafloor communities and instead resembled organotrophic communities in forest soils. This suggests that terrigenous sediments retain indigenous community members tens of millions of years after burial in the seabed.

Asphaltene detection using surface enhanced Raman scattering (SERS).

Surface enhanced Raman spectroscopy using a gold substrate and excitation at 514 nm can detect sub parts per million quantities of asphaltene and thereby petroleum. This simple format and sensitivity make it transformative for applications including sample triage, flow assurance, environmental protection and analysis of unique one of a kind materials.

The liquid-liquid diffusive extraction of hydrocarbons from a North Sea oil using a microfluidic format.

Extraction of a GC-amenable hydrocarbon fraction from oil by liquid-liquid diffusion across a laminar interface can be performed in a microfluidic format. Analysis of figures of merit, determined using standard analytical techniques, show this method to be an effective new tool for rapidly processing small quantities of oil and petroleum for GC analysis. Methods based upon similar microsystems devices could find widespread use in a variety of fields, including those associated with organic geochemistry and oil exploration and production, where the manipulation of petroleum constituents (greater than C14) is necessary for analytical purposes.