The biotin synthesis pathway in Mycobacteria tuberculosis is a new target for the development of anti-tuberculosis drugs / 药学学报

italic>Mycobacterium tuberculosis, responsible for tuberculosis (TB), remains a major health problem worldwide and is one of the infectious diseases causing increased morbidity and mortality worldwide. Biotin, namely vitamin H, is an important cofactor necessary for fatty acid biosynthesis, gluconeogenesis and amino acid metabolism in organisms including Mycobacterium tuberculosis. Due to its inability to ingestion biotin from outside, Mycobacterium tuberculosis can only obtain biotin through biotin biosynthesis. Different from the classical BioC-BioH, BioI-BioW and non-classical BioZ pathways, Mycobacterium tuberculosis synthesized biotin by "BioC-BioH(2)" pathway in the early stage. This review focuses on the unique biotin synthesis pathway of Mycobacterium tuberculosis and its key genes, especially the response of this pathway and biotin-dependent carboxylase to tuberculosis first-and second-line drugs, as well as inhibitors and natural products targeting biotin synthesis.

Biotinase deficiency in a child with predominantly spinal cord disease:a case report and literature review / 中华神经科杂志

Objective:To describe the clinical features of pediatric biotinase deficiency (BTD) manifested as spinal cord disease.Methods:The clinical data of a child with spinal cord lesions due to biotinase deficiency, diagnosed in Beijing Children′s Hospital in 2020, were collected. The cases with complete clinical data retrieved on literature reported in China National Knowledge Infrastructure, Wanfang Data knowledge Service Platform and PubMed (up to August 2021) by using search terms of biotinase deficiency, pediatric, spinal cord, myelopathy and myelitis were summarized.Results:The patient was a 3 years and 5 months old boy with the main clinical manifestations of subacute progressive limb weakness and wheezing. Physical examination showed sparse hair, rough skin, spastic paraparesis and developmental delay. Cerebrospinal lactic acid was increased (5.67 mmol/L). Cranial magnetic resonance imaging (MRI) showed diffuse T 2/fluid attenuated inversion recovery hyperintensity of the midbrain, dorsal pons, edulla, periacqueductal grey and optic tracts. Spinal cord lesions were extended from the medulla up to the level of the conus. Urineketone bodies and 3-hydroxyisurate were increased. The activity of biotinidase was 0.27 pmol/min (3 mm disc), being 7% of mean normal serum activity. Genetic studies revealed homozygous mutation in the BTD gene [c.284T>A (p.I95N)]. After biotin supplementation for 6 months, the only evident abnormality was residual spasticity of lower limbs. Fourteen English literatures and 2 Chinese literatures including 18 cases were collected. The onset age was from 2 months to 15 years (median age was 4 years). Among them, 11 cases had cranial MRI abnormalities, of which all involved brain stem, 6 cases involved optic tracts and (or) optic chiasm. All 18 cases had spinal cord MRI abnormalities with longitudinally extensive lesion, mostly involved cervical and thoracic spinal segments, and 3 cases involved all spinal segments. Twelve cases received immunotherapy, and 6 were partially improved, 6 were completely invalid. After biotin supplementation, 12 patients had neurological disability. Conclusions:BTD should be included in the differential diagnosis of subacute myelopathy, regardless of the onset age. Early diagnosis and treatment can prevent irreversible neurological damage.

A case report of biotin-thiamine-responsive basal ganglia disease / 中华神经科杂志

Biotin-thiamine-responsive basal ganglia disease is a rare treatable autosomal recessive neurometabolic disorder caused by mutations in SLC19A3 gene, encoding a transporter of thiamine across the plasma membrane. In the present study, a 29-year-old male patient with epilepsy as the first symptom, accompanied by hypokinesia, extraocular muscle paralysis and delayed dystonia was reported. The brain magnetic resonance imaging revealed abnormal symmetrical signals of bilateral caudate nucleus and lenticular nucleus. The patient was diagnosed as biotin-thiamine-responsive basal ganglia disease by gene detection. After treatment with biotin and thiamine, the symptoms were relieved and the brain lesions subsided.

Effects of material interfaces on orientation and function of fibrinogen / 生物医学工程学杂志

Fibrinogen (Fg) in human plasma plays an important role in hemostasis, vascular repair and tissue integrity. The surface chemistry of extracellular matrix or biological materials affects the orientation and distribution of Fg, and changes the exposure of integrin binding sites, thereby affecting its adhesion function to platelets. Here, the quantity, morphology and side chain exposure of Fg adsorbed on hydrophilic, hydrophobic and avidin surfaces were measured by atomic force microscopy (AFM) and flow cytometry (FCM), then the rolling behavior of platelets on Fg was observed through a parallel plate flow chamber system. Our results show that the hydrophobic surface leads to a large amount of cross-linking and aggregation of Fg, while the hydrophilic surface reduces the adsorption and accumulation of Fg while causing the exposure and spreading of the α chain on Fg and further mediating the adhesion of platelets. Fg immobilized by avidin / biotin on hydrophilic surface can maintain the monomer state, avoid over exposure and stretching of α chain, and bind to the platelets activated by the A1 domain of von Willebrand factor instead of inactivated platelets. This study would be helpful for improving the blood compatibility of implant biomaterials and reasonable experimental design of coagulation

Comparison of the apoptotic effects of topically applied papaverine, diltiazem, and nitroprusside to internal thoracic artery

Abstract Objective: To detect and to compare the apoptotic effects of intraoperatively topically applied diltiazem, papaverine, and nitroprusside. Methods: Internal thoracic artery segments of ten patients were obtained during coronary bypass grafting surgery. Each internal thoracic artery segment was divided into four pieces and immersed into four different solutions containing separately saline (Group S), diltiazem (Group D), papaverine (Group P), and nitroprusside (Group N). Each segment was examined with both hematoxylin-eosin and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method in order to determine and quantify apoptosis. Results: Apoptotic cells were counted in 50 microscopic areas of each segment. No significant difference was observed among the four groups according to hematoxylin-eosin staining. However, the TUNEL method revealed a significant increase in mean apoptotic cells in the diltiazem group when compared with the other three groups (Group S=4.25±1.4; Group D=13.31±2.8; Group N=9.48±2.09; Group P=10.75±2.37). The differences between groups were significant (P=0.0001). No difference was observed between the samples of the diabetic and non-diabetic patients in any of the study groups. Conclusion: The benefit of topically applied vasodilator drugs must outweigh the potential adverse effects. In terms of apoptosis, diltiazem was found to have the most deleterious effects on internal thoracic artery graft segments. Of the analyzed medical agents, nitroprusside was found to have the least apoptotic activity, followed by papaverine. Diabetes did not have significant effect on the occurrence of apoptosis in left internal thoracic artery grafts.

A magnetism/laser-auxiliary cascaded drug delivery to pulmonary carcinoma

Although high-efficiency targeted delivery is investigated for years, the efficiency of tumor targeting seems still a hard core to smash. To overcome this problem, we design a three-step delivery strategy based on streptavidin-biotin interaction with the help of c(RGDfK), magnetic fields and lasers. The ultrasmall superparamagnetic iron oxide nanoparticles (USIONPs) modified with c(RGDfK) and biotin are delivered at step 1, followed by streptavidin and the doxorubicin (Dox) loaded nanosystems conjugated with biotin at steps 2 and 3, respectively. The delivery systems were proved to be efficient on A549 cells. The co-localization of signal for each step revealed the targeting mechanism. The external magnetic field could further amplify the endocytosis of USPIONs based on c(RGDfK), and magnify the uptake distinctions among different test groups. Based on photoacoustic imaging, laser-heating treatment could enhance the permeability of tumor venous blood vessels and change the insufficient blood flow in cancer. Then, it was noticed that only three-step delivery with laser-heating and magnetic fields realized the highest tumor distribution of nanosystem. Finally, the magnetism/laser-auxiliary cascaded delivery exhibited the best antitumor efficacy. Generally, this study demonstrated the necessity of combining physical, biological and chemical means of targeting.

An unusual presentation of biotinidase deficiency in infant: High anion gap metabolic acidosis and Burkholderia cepacia sepsis

Biotinidase deficiency (BD) is an inborn metabolic disorder caused by low enzyme activity giving rise to impaired biotin release from dietary proteins. The first symptoms may be seen at first week following birth until 1 year of age. The goal of the therapy is to increase biotin bioavailability by daily 5-20 mg lifelong biotin replacement. Three-month-old girl born to nonconsanguineous parents, admitted to pediatric intensive care with multiple seizures, breathing difficulty and posturing. Blood investigations showed thrombocytopenia and high anion gap metabolic acidosis (HAGMA). Enzyme assay for biotinidase revealed low activities. Urinary organic acid analysis was normal. Enzyme activity is <10% in severe cases whereas between 10-30% in partial deficiency. BD can cause metabolic ketoacidosis, Hyperammonemia and organic Aciduria. BD behaves like immunodeficiency. Rarely bacterial infection can be seen. Treatment is lifelong biotin replacement.

A case of multiple carboxylase deficiency presenting with skin lesions as the initial symptom induced by a novel mutation in the holocarboxylase synthetase gene / 中华皮肤科杂志

A male patient, who was aged 3 months and 12 days, presented with well-circumscribed erythema and scales on the scrotum, perineum, buttocks and perianal region at 1 month after birth. The lesions gradually involved the perioral and axillary regions, flexor aspect of the elbow, popliteal fossa and neck. Shortness of breath, crying, dysphoria and vomiting occurred without fever and cough 3 days before hospitalization. Laboratory examinations at admission showed metabolic acidosis, hyperlactacidemia, hyperammonemia and organic aciduria. Second-generation sequencing and Sanger sequencing of the holocarboxylase synthetase gene revealed a known mutation c.1522C>T in exon 9 and a novel mutation c.1796_1814del in exon 11. According to a guideline from the American College of Medical Genetics and Genomics, this novel mutation was ranked as a pathogenic mutation. The patient was diagnosed as multiple carboxylase deficiency. His clinical symptoms were improved after oral biotin treatment, no neurological symptoms or signs were observed.

Establishment of specific IgE antibody detection method for Tyrophagus putrescentiae allergen based on nano-magnetic particle chemiluminescence analysis / 中华检验医学杂志

Objective@#To establish a nanometer magnetic particle chemiluminescence methodfor the detection of specific IgE antibodies to Tyrophagus putrefaciens allergen.@*Methods@#According to the routine operation steps of chemiluminescence, chemiluminescence reaction system and suitable immune reaction conditions for detection of specific IgE of Tyrophagus putrescentiae allergen are established. Considering the performance of the chemiluminescence method established in this paper, the American Somerfly Phadia method wasused as the gold standard to evaluate the test performance of the established chemiluminescence method.@*Results@#In thechemiluminescence reaction system, Luminol concentration in luminescent substrate A solution is 0.4 mg/ml, Urea hydrogen peroxidein luminescent substrate B solutionis 0.2 mg/ml.The sensitivity of this luminescent reaction system to horseradish peroxidase (HRP) is very high, the minimum detectable HRP is 0.01 ng/ml.In the immune response, the room temperature light-shielding reaction was detected for 5 min after the addition of substrates A and B, and the detection values were effective within 5-30 min. 37 ℃ is optimum luminescence reaction temperature. Choose the range of 0.35-100 IU/ml as the standard curve. According to the results of 120 clinical trials, using Phadia (immunofluorescence method) as the gold standard, the chemiluminescence method established in this study has significant significance for the detection of Tyrophagus putrescentiae allergen.@*Conclusion@#A nanometer magnetic particle chemiluminescence method was successfully established for the detection of specific IgE antibodies to Tyrophagus putrescentiae allergen.

Synthesis and Evaluation of Biotinylated Small Molecular Drugs with Long Chain / 中国药学杂志

OBJECTIVE: To set up an easy and effective method for biotinylation of small molecule drugs with long chain. METHODS: Biotinylated 6-aminocaproic acid was synthesized as intermediate by one step method, doxorubicin(DOX) with auto-fluorescence was used as the first drug, and by DCC and DMAP catalysis, biotinylated DOX was synthesized. Using the double fluorescence system of DOX, the binding ability of biotinylated DOX to avidin and its biological activity were determined. When verified to be reasonable and effective, the method was applied to catalyze biotinylated paclitexal (PTX) which didn′t have auto-fluorescence itself, and the physical and chemical characteristics, and biological activities as well as the visualization were tested. RESULTS: The binding rate of synthesized DOX to avidin was 93.7%; the cells inhibition rate and localization were the same as DOX; the purity of biotinylated PTX was 84.42%, and the structure shown by NMR was correct; the cell inhibition rate was the same as PTX; the combination of PTX with microtubules was observed by visual modification. CONCLUSION: The method supplies a temperate way for biotinylation, and can be used for the synthesis and visualization of small molecules as probes and research of drug mechanism.

Establishment of specific IgE antibody detection method for Tyrophagus putrescentiae allergen based on nano-magnetic particle chemiluminescence analysis / 中华检验医学杂志

Objective To establish a nanometer magnetic particle chemiluminescence methodfor the detection of specific IgE antibodies to Tyrophagus putrefaciens allergen.Methods According to the routine operation steps of chemiluminescence, chemiluminescence reaction system and suitable immune reaction conditions for detection of specific IgE of Tyrophagus putrescentiae allergen are established. Considering the performance of the chemiluminescence method established in this paper, the American Somerfly Phadia method wasused as the gold standard to evaluate the test performance of the established chemiluminescence method. Results In thechemiluminescence reaction system, Luminol concentration in luminescent substrate A solution is 0.4 mg/ml, Urea hydrogen peroxidein luminescent substrate B solutionis 0.2 mg/ml.The sensitivity of this luminescent reaction system to horseradish peroxidase (HRP) is very high, the minimum detectable HRP is 0.01 ng/ml. In the immune response, the room temperature light-shielding reaction was detected for 5 min after the addition of substrates A and B, and the detection values were effective within 5-30 min. 37 ℃ is optimum luminescence reaction temperature. Choose the range of 0.35-100 IU/ml as the standard curve. According to the results of 120 clinical trials, using Phadia (immunofluorescence method) as the gold standard, the chemiluminescence method established in this study has significant significance for the detection of Tyrophagus putrescentiae allergen.Conclusion A nanometer magnetic particle chemiluminescence method was successfully established for the detection of specific IgE antibodies to Tyrophagus putrescentiae allergen.

MCC1019, a selective inhibitor of the Polo-box domain of Polo-like kinase 1 as novel, potent anticancer candidate

Polo-like kinase (PLK1) has been identified as a potential target for cancer treatment. Although a number of small molecules have been investigated as PLK1 inhibitors, many of which showed limited selectivity. PLK1 harbors a regulatory domain, the Polo box domain (PBD), which has a key regulatory function for kinase activity and substrate recognition. We report on 3-bromomethyl-benzofuran-2-carboxylic acid ethyl ester (designated: MCC1019) as selective PLK1 inhibitor targeting PLK1 PBD. Cytotoxicity and fluorescence polarization-based screening were applied to a library of 1162 drug-like compounds to identify potential inhibitors of PLK1 PBD. The activity of compound MC1019 against the PLK1 PBD was confirmed using fluorescence polarization and microscale thermophoresis. This compound exerted specificity towards PLK1 over PLK2 and PLK3. MCC1019 showed cytotoxic activity in a panel of different cancer cell lines. Mechanistic investigations in A549 lung adenocarcinoma cells revealed that MCC1019 induced cell growth inhibition through inactivation of AKT signaling pathway, it also induced prolonged mitotic arrest-a phenomenon known as mitotic catastrophe, which is followed by immediate cell death apoptosis and necroptosis. MCC1019 significantly inhibited tumor growth in a murine lung cancer model without affecting body weight or vital organ size, and reduced the growth of metastatic lesions in the lung. We propose MCC1019 as promising anti-cancer drug candidate.

Construction and in vitro and in vivo Preliminary Evaluation of Biotin-poloxamer Conjugate Polymeric Mi-celles for Epirubicin / 中国药师

Objective:To prepare biotin-poloxamer(BP) conjugate micelles for epirubicin through biotin conjugated on poloxam-er. Methods:Epirubicin(EPI) was encapsulated in BP micelles. The EPI-loaded BP micelles were characterized by its particle size, zeta potential,surface morphology,as well as the efficiency of drug loading and drug encapsulation and drug release. Marrow leukemia HL-60 cells were used to evaluate the cell cytotoxicity of EPI-loaded BP micelles in vitro. The tumor model in nude mice was estab-lished through the subcutaneous injection of HL-60 cells, and then the inhibitory effect of EPI-loaded BP micelles on tumor volume growth was investigated.Results:It was found that the average particle size of EPI-loaded BP micelles was about 100 nm. In addition, the enhanced cellular uptake ability of EPI-loaded BP micelles was proved by fluorescence microscope observation. The efficiency order of the tumor volume growth inhibition was:EPI-loaded BP micelles > EPI-loaded MATP micelles> EPI-loaded poloxamer micelles>EPI. BP micelles showed significant antitumor activity and low toxicity when compared with the non-targeted micelles. Conclusion:With the advantages of EPR effect and tumor-targeting potential,BP conjugate micelles might be developed as a new system for chemo-therapeutics. However,the tumor targeting technique should be demonstrated further by the other cell experiments and large animal ex-periments.

Preparation of polyclonal antibody and establishment of chemiluminescence immunoassay for aldosterone / 中国免疫学杂志

Objective:The polyclonal antibody of aldosterone (ALD) for immunoassay was developed.And a chemiluminescence immunoassay (CLIA) for the determination of ALD in human blood was established.Methods:Aldosterone oxime was prepared by chemical modification and then conjugated with BSA to prepare immunogen.Rabbit anti ALD polyclonal antibody was prepared by immunizing rabbits with the ALD-BSA.The CLIA of ALD was performed using biotin streptavidin amplification system and competition method.Results:After identification,rabbit No.3 received the highest sensitivity to ALD antibody,and the 50％ binding inhibition (IC50) value for ALD concentration was 268 pg/ml.The measuring range of CLIA method using the antibody was 62.5-2 000 pg/ml.The assay sensitivity was 23.7 pg/ml.The intra-and inter-assay coefficients of variation were 6.9％-9.5％ and 8.5％-12.7％,respectively.Analytical recovery rate was in the range of 93.1％-104.1％.The correlation coefficient between measured and expected values were 0.996 after serial dilution.Compared with radioimmunoassay kit,the correlative equation was y =0.932x+4.596,the correlation coefficient was 0.948 (n =95).Conclusion:The result of methodological identification shows that it was in line with the basic requirements of clinical application.

Preparation of biotin-grafted pullulan acetate nanoparticles conjugated with CD3 antibodies and their uptake of T cells / 医学研究生学报

Objective Cytotoxic T lymphocytes are the main effector cells of anti-tumor immunity. Active targeting of nanoparticles to T cells and activation of T cells can be achieved by conjugation with specific antibodies. We prepared the biotin-grafted pullulan acetate nanoparticles conjugated with CD3 (Bio-PA-CD3 NPs), and explored their effects on the proliferation, cytokine secretion and uptake of CD8+T cells.Methods We prepared Bio-PA NPs by the dialysis method, conjugated CD3 antibodies to the surface of NPs to make Bio-PA-CD3 NPs, and measured the diameter and Zeta potential of the NPs. We evaluated the effects of the NPs on the proliferation of CD8+T cells and the secretion of cytokines by CCK-8 assay and ELISA, respectively, and quantitatively analyzed the cellular uptakes of the Bio-PA-CD3 NPs by the flow cytometry.Results The Bio-PA-CD3 NPs exhibited regular spherical shapes of even size and with no adhesion. The content of CD3 antibodies on the surface of the NPs decreased with the increased degree of biotin substitution. The CD3 contents of the Bio-PA-CD3 NPs with biotin substitution degrees of 1.6%, 5.4% and 6.3% were (36.1±4.4), (21.4±4.3) and (10.3±4.7) μg/mg, respectively. Compared with Bio-PA NPs, Bio-PA-CD3 NPs at a certain concentration significantly enhanced the proliferation of CD8+T cells in vitro and promoted the secretion of IFN-γ, TNF-β and IL-2 cytokines. The Bio-PA-CD3 NPs manifested a higher cellular uptake with the increased content of CD3 antibodies.Conclusion The Bio-PA-CD3 NPs we prepared could be a promising agent to enhance the immune effect of T cells.

Preparation, characterization, and antiproliferative activities of biotin-decorated docetaxel-loaded bovine serum albumin nanoparticles

ABSTRACT The aim of the present study was to characterize biotin-decorated docetaxel-loaded bovine serum albumin nanoparticles (DTX-BIO-BSA-NPs) and evaluate their antiproliferative activity in vitro. The particle size of prepared DTX-BIO-BSA-NPs was found to be always lower than 200 nm, with sizes of 166.9, 160.3, 159.0, 176.1 and 184.8 nm and the zeta potential was -29.51, -28.54, -36.54, -36.08 and -27.56 mV after redissolution with water for 0, 1, 2, 4 and 8 hours, respectively. The polydispersity index (PDI) was stable in the range of 0.170 - 0.178. In the in vitro drug-release study, the DTX-BIO-BSA-NPs targeted a human breast cancer cell line MCF-7 effectively. The x-ray diffraction spectrum and DSC curve of DTX-BIO-BSA-NPs suggested that docetaxel was in an amorphous or disordered crystalline phase in DTX-BIO-BSA-NPs. In vitro cytotoxicity results showed that DTX-BIO-BSA-NPs inhibits proliferation of MCF-7, SGC7901, LS-174T and A549 cells in a concentration-dependent manner after exposure to DTX-BIO-BSA-NPs for 48 hours. Taken together, these results indicate that DTX-BIO-BSA-NPs may have potential as an alternative delivery system for parenteral administration of docetaxel.

Development of an Enhanced Colloidal Gold Immunochromatographic Assay for Detection of Imidaclothiz / 分析化学

An enhanced gold immunochromatographic assay ( GICA ) with simplicity, rapidity and high sensitivity was developed to detect imidaclothiz by using the high affinity between biotin and streptavidin. The 13-nm AuNPs were double-labeled with anti-imidaclothiz antibody and biotinylated DNA, and the 41-nm AuNPs were labeled with streptavidin to prepare an enhanced gold immunochromatographic test strip for imidaclothiz. The working conditions of the strip were systematically optimized, and the sensitivity, specificity, precision and accuracy were assessed by testing the cross-reactivity ( CR) , spiked recovery and validation with high performance liquid chromatography ( HPLC) . Under the optimal conditions, the detection could be completed in 10 min with visual result, and the limit of detection ( LOD ) was 25 ng/mL. The analysis showed no cross-reactivity with analogues of imidaclothiz except for imidacloprid. The detection results of GICA agreed with the spiked concentrations of imidaclothiz at spiked levels of 0 . 05 , 0 . 5 and 5 μg/g in river water, rice, cucumber, tomato, pear, cabbage and apple samples. The detection results of GICA for imidaclothiz in unknown concentration river water and pear samples were consistent with that of HPLC.

Information other than laboratory results should be valued when diagnosing thyroid diseases:Lessons from the misdiagnosis of Graves' hyperthyroidism in a woman taking biotin / 中华内分泌代谢杂志

We report a young woman who was misdiagnosed as Graves' hyperthyroidism due to biotin immunoassay interference. Base on this case, essentials for diagnosis of thyroid diseases are discussed. We propose that in the clinical practice, a patient-centered professionalism should be consistently followed, and information other than laboratory findings should be valued.

Information other than laboratory results should be valued when diagnosing thyroid diseases:Lessons from the misdiagnosis of Graves' hyperthyroidism in a woman taking biotin / 中华内分泌代谢杂志

We report a young woman who was misdiagnosed as Graves' hyperthyroidism due to biotin immunoassay interference. Base on this case, essentials for diagnosis of thyroid diseases are discussed. We propose that in the clinical practice, a patient-centered professionalism should be consistently followed, and information other than laboratory findings should be valued.

Biotinase deficiency manifested as encephalomyelopathy: a case report and literature review / 临床儿科杂志

Objective To explore the diagnosis and treatment of biotinase deficiency (BTD) manifested as encephalomyelopathy.Methods The clinical data of one child with BTD were retrospectively analyzed.The pertinent literatures were reviewed.Results A six-year-old male child suffered from progressive spastic paralysis of lower limbs for 3 months before admission.A similar symptoms occurred after a cold in 3-year-old.It was easy to peel skin on her hands and she had angular stomatitis.Audio visual evoked potential was detected to be abnormal in other hospital.After hospitalizion,the cerebrospinal fluid examination was normal,and MRI showed long T1 long T2 signals bilateral occipital lobe and basal ganglia region.Because the child represented medulla palsy,and so the tracheal intubation ventilator was administrated to assist ventilation.Urine gas chromatography/mass spectrometry (GC/MS) analysis showed increases of lactic acid,3-hydroxy acid,3-tiglyl glycine,methylcitric acid,and ethylene lactic acid.Serum MS/MS analysis showed that the concentrations of propionyl camitine and 3-hydroxyisovaleryl carnitine were increase obviously.The serum biotinase level was significantly decrease to 0.076 pmol/(min·mm3).The diagnosis of BTD was confirmed.After supplementation biotin,40 mg/d,the ventilator was successfully weaned on the third day,the child walked again after 2 weeks,and the rash was vanished.After 3 weeks,the head MRI showed disappearance of the original lesion,and there was no abnormal in spinal cord.The BTD gene detected by PCR direct sequencing showed a heterozygosis mutation of T172T/C in the second exon and a homozygous mutation of T1413C in the fourth exon,which was confirmed as a pathogenic mutation by pedigree verification and database query.After discharge,the oral administration of biotin 20 mg/d continued,and no abnormality was found in 2 years of follow-up.Conclusions The manifestations of BTD are complex and diverse.The analysis of urine GC/MS and serum MS/MS can assist the diagnosis.The determination of biotinase activity and gene detection of BTD can further confirm the diagnosis.Timely biotin supplementation has significant treatment efficacy.