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At least 19 recordsLinked to original sources
PubMed2026

Characterization of a Novel BTD Hypomorphic Variant in a Patient with Complex Neurodevelopmental Delay: Resolving Actionable Metabolic Vulnerabilities Beyond Borderline Plasma Biochemistry.

Plasma biochemistry often presents significant limitations in diagnosing borderline metabolic disorders, particularly within complex neurodevelopmental phenotypes. Here, we present the clinical genomic evaluation of a six-year patient presenting with early-onset hypotonia and severe gastrointestinal complications whose newborn screening panel did not evaluate biotinidase (BTD) activity. While initial baseline plasma biochemistry yielded borderline residual BTD function (46% of the population mean), targeted sequencing identified a novel, compound heterozygous hypomorphic variant (p.Thr459Met) in trans with the common p.Asp424His allele. In vitro functional validation confirmed that p.Thr459Met induces severe protein misfolding and intracellular retention, impairing enzyme secretion. Biotin supplementation triggered a documented and favorable therapeutic improvement, establishing this borderline enzymatic background as an actionable metabolic vulnerability unmasked by chronic gastrointestinal stressors. This study underscores the critical value of functional genomic characterization over static enzymatic biomarkers to identify highly treatable metabolic components within heterogeneous clinical landscapes.

Humans↗
PubMed1978

[Biochemistry of depression. Literature analysis].

The author goes briefly over the metabolism of the main cerebral monoamines, the functioning of synapses, as well as the methods used in studying the biochemistry of depression. Beyond all existing contradictory results, a review of the main works in this field enables us to point out some leading ideas:--Depression would be due to and/or accompanied by a monoaminergic deficiency: some authors emphasize the serotonin one, others the noradrenaline one.--The regulation of mood most probably finds its origin in the monoaminergic balance, rather than in the gross rates of any particular monoamine.--Disturbances are to be found on all metabolic levels: monoaminergic, hydroelectrolytic, hormonal, glucidic, lipidic, lipidic... Close intrication exists between those different metabolisms.--The interaction between the different aminergic systems and the metabolic ways, as well as the dispersion of the acknowledged results, impose more and more the necessity of a biochemical typology of depression, which would lead to a predictive approach to the evolution and treatment of depressive illness.

Adrenal Cortex Hormones↗
PubMed1976

[Relevance of biochemistry in diagnosis and development of alcoholic liver disease (author's transl)].

In a group of 205 patients with alcoholic diseases of liver the diagnostic relevance of biochemical tests (GOT, GPT, AP, GGTP, BSP) was reconsidered with discriminatory process (separation of diagnosis). The group contained 16 patients with nutritional-caused and 41 cases with alcoholic-caused fatty-infiltration of liver. 148 patients showed a toxic chronic liver disease; 52 a chronic hepatitis and 96 cirrhosis of liver. Laparoscopy and morphology guaranteed the clinical diagnosis and therefore the accuracy of biochemistry in separation of diagnosis was given. The biochemical tests were not able to offer a separation of fatty-infiltration with reference to cause, changes of the process in toxic hepatitis and cirrhosis were announced. Intersection in several cases was noticed and biochemical tests were not able to substitute endoscopy and morphology for clinical and diagnostic use in all cases. In every regard the enzyme-tests,--above mentioned--, and determination of sulfobromthalein are aptly to development of diseases and deficiency of alcohol.

Alanine Transaminase↗
PubMedDate not supplied

The pathology and biochemistry of paraquat.

After the administration of paraquat to rats the lung is the organ most severely damaged. The pathology in the lung can be divided into two distinct phases: (1) a destruction phase lasting a few days with damage to the type I and type II alveolar epithelial cells, oedema and haemorrhage (most of the rats which die after dosing with paraquat do so during this phase); (2) a reparative phase with regeneration of the epithelium and, in areas of severe damage, a characteristic proliferation of fibroblasts. In both phases of the lesion the death of the rats results from anoxia. Paraquat is selectively accumulated by the rat lung in comparison with other tissues and this accounts, at least in part, for the specific toxic effect in this organ. The accumulation into the lung was shown by in vitro studies to depend on energy and is inhibited by various endogenous and exogenous compounds. This uptake process is not that which has been described for 5-hydroxytryptamine and evidence is presented to suggest that the type I and type II alveolar epithelial cells are sites of accumulation. When paraquat is present in lung cells, it undergoes a cyclical reduction and oxidation with the production of superoxide anion. This radical may lead directly or indirectly to the formation of lipid peroxides and hence to cell death. However, paraquat stimulates the pentose-phosphate pathway and both reduces the level of NADPH and inhibits fatty acid synthesis in the lung. These effects occur when there is only minimal ultrastructural damage to the lung cells. It is suggested, therefore, that the primary mechanism of toxicity of paraquat is the extreme oxidation of NADPH which inhibits vital physiological processes and renders the cell more susceptible to attack from lipid hydroperoxides.

Animals↗
PubMed1977

[Physiology and biochemistry of streptomycetes. VIII. Esterase activity and production of turimycin in cultures of Streptomyces hygroscopicus JA 6599].

Esterase in cell-free extracts of Streptomyces hygroscopicus JA 6599 has a temperature-optimum of 35 degrees C, a pH-optimum with p-nitrophenylacetate as substrate at pH 7.7--8.1, with alpha-naphthylacetate at pH 7--9. Michaelis constants in cell-free extracts: with alpha-naphthylacetate Km = = 0.71 mM, with p-nitrophenylacetate Km = 0.21 mM. Phenylesters were better hydrolyzed than naphthylesters, phenylacetate was best hydrolyzed; beta-naphthylacetate was better hydrolyzed than alpha-naphthylacetate. Among the naphthylesters the ester of propionic acid was hydrolyzed best. Caprylate, stearate, and 0,0-diethyl-0-(p-nitrophenyl)-phosphate inhibit the splitting of alpha-naphthylacetate. A comparison with esterases of other biological origin shows that the enzyme studied can be a carboxylesterase (E.C.3.1.1.1.). In cultures of JA 6599 V13 and JA 6599-6 the change of esterase activity during the fermentation was determined. We found a carrelation between the enzymatic activity and the antibiotic-concentration in the culture medium.

Acetates↗
PubMed2025

Prenatal screening for trisomy 21 (Down syndrome) using first- and second-trimester biochemistry and nuchal translucency: A technical standard of the American College of Medical Genetics and Genomics (ACMG).

This technical standard was developed as a guide for laboratories performing prenatal screening for Down syndrome. It addresses 3 topics: second trimester (triple or quad), first trimester, including incorporation of nuchal translucency, and current directions in cell-free DNA screening. Analytic methods, clinical considerations, screening performance, guidelines for reporting second trimester, first trimester, integrated, contingent, and reflex screening tests for Down syndrome, are discussed. Individual laboratories are responsible for meeting the quality assurance standards described by the Clinical Laboratory Improvement Amendments, the College of American Pathologists, and other regulatory agencies, with respect to appropriate sample documentation, assay validation, general proficiency, and quality control measures.

Humans↗
PubMed1976

Biochemistry of copper.

Copper, as a component of numerous cuproenzymes, plays a vital role in many physiologic functions in man and animals. From the stand-point of human health there are at least three functional areas of prime importance. Copper is involved in the development and maintenance of cardiovascular and skeletal integrity, central nervous system structure and function, and erythropoietic function including iron metabolism. Although there is no evidence for widespread copper deficiency in the human population, it does occur, owing to genetic defects and other precipitating factors. A clear understanding of the functions of copper and its mechanisms of action could prove highly beneficial in the solution of present and unforeseen problems in medicine.

Anemia↗