Objective To investigate the in vitro pharmaceutical properties(protein content and purity,biological activity)and in vivo pharmacodynamics(procoagulant activity)of recombinant human thrombin.Methods The content of protein in recombinant human thrombin was determined by folin-reagent method.Sodium dodecyl sulphate-polyacrylamide gel electrophoresis was used to determine its purity.Human thrombin activity test was applied to detect its biological activity.Eighteen male New Zealand rabbits were randomly divided according to body mass into blank group(0.9％NaCl solution),experimental-L group(200 U·mL-1 recombinant human thrombin)and experimental-H group(1 000 U·mL-1 recombinant human thrombin),6 rabbits in each group.The procoagulant effects of recombinant human thrombin were investigated in the rabbit liver injury model.Results The protein content of recombinant human thrombin was(1.980±0.024)mg per container,its biological activity was(5764.3±197.7)U per container and its biological specific activity was(2 911.2±99.8)U·mg-1.The target protein(35 kD in non-reductive electrophoresis)has a single band and few miscellaneous proteins were found on the gel.Compared with the blank group,the mean hemostasis time and mean blood loss weight of rabbit liver wound were reduced by 57.0％and 87.7％in the experimental-L group,which in the experimental-H group were reduced by 71.8％and 91.9％.Conclusion Recombinant human thrombin has high protein purity and specific biological activity,and has significant procoagulant activity in vivo.

Objective To investigate the in vitro pharmaceutical properties(protein content and purity,biological activity)and in vivo pharmacodynamics(procoagulant activity)of recombinant human thrombin.Methods The content of protein in recombinant human thrombin was determined by folin-reagent method.Sodium dodecyl sulphate-polyacrylamide gel electrophoresis was used to determine its purity.Human thrombin activity test was applied to detect its biological activity.Eighteen male New Zealand rabbits were randomly divided according to body mass into blank group(0.9％NaCl solution),experimental-L group(200 U·mL-1 recombinant human thrombin)and experimental-H group(1 000 U·mL-1 recombinant human thrombin),6 rabbits in each group.The procoagulant effects of recombinant human thrombin were investigated in the rabbit liver injury model.Results The protein content of recombinant human thrombin was(1.980±0.024)mg per container,its biological activity was(5764.3±197.7)U per container and its biological specific activity was(2 911.2±99.8)U·mg-1.The target protein(35 kD in non-reductive electrophoresis)has a single band and few miscellaneous proteins were found on the gel.Compared with the blank group,the mean hemostasis time and mean blood loss weight of rabbit liver wound were reduced by 57.0％and 87.7％in the experimental-L group,which in the experimental-H group were reduced by 71.8％and 91.9％.Conclusion Recombinant human thrombin has high protein purity and specific biological activity,and has significant procoagulant activity in vivo.

An 8-year-old girl who had experienced intermittent cough and fever over a 3 year period, was admitted after experiencing a recurrence for one month. One year ago the patient experienced a recurrent oral mucosal ulcer. Physical examination showed vitiligo in the skin of the upper right back. Routine blood tests and immune function tests performed in other hospitals had shown normal results. Multiple lung CT scans showed pulmonary infection. The patient had recurrent fever and cough and persistent presence of some lesions after anti-infective therapy. The antitubercular therapy was ineffective. Routine blood tests after admission showed agranulocytosis. Gene detection was performed and she was diagnosed with dyskeratosis congenita caused by homozygous mutation in RTEL1. Patients with dyskeratosis congenita with RTEL1 gene mutation tend to develop pulmonary complications. Since RTEL1 gene sequence is highly variable with many mutation sites and patterns and can be inherited via autosomal dominant or recessive inheritance, this disease often has various clinical manifestations, which may lead to missed diagnosis or misdiagnosis. For children with unexplained recurrent pulmonary infection, examinations of the oral cavity, skin, and nails and toes should be taken and routine blood tests should be performed to exclude dyskeratosis congenita. There are no specific therapies for dyskeratosis congenita at present, and when bone marrow failure and pulmonary failure occur, hematopoietic stem cell transplantation and lung transplantation are the only therapies. Androgen and its derivatives are effective in some patients. Drugs targeting the telomere may be promising for patients with dyskeratosis congenita.
Child ; Dyskeratosis Congenita ; complications ; therapy ; Female ; Humans ; Mouth Diseases ; etiology ; Mouth Mucosa ; pathology ; Recurrence ; Respiratory Tract Infections ; etiology ; Telomere ; drug effects ; Ulcer ; etiology