[Effect of low dose erythromycin on the proliferation of granulation tissue after tracheal injury]

Objective: To investigate the effect of low dose erythromycin on the proliferation of granulation tissue after tracheal injury. Methods: Forty-two rabbits were randomly divided into 7 groups (n=6 each), group A (saline control group), group B (penicillin group), group C (low dose erythromycin group), group D (low dose erythromycin and penicillin group), group E (budesonide group), group F (low dose erythromycin and budesonide group), group G (low dose erythromycin, penicillin and budesonide group). All rabbits received tracheotomy, and the tracheal mucosa was scraped with a nylon brush 20 times for tracheal stenosis model. Rabbits were treated with corresponding drugs from a week before operation to 9 days after operation. The serum concentrations of transforming growth factor - beta 1 (TGF-β(1)), vascular endothelial growth factor (VEGF), interleukin (IL) -6, IL-8 were determined and the tracheal specimens were harvested for measuring degree of stenosis on the 10th day after operation. Results: Serum concentrations of TGF-β(1) in group A, B, C, D, E, F and G were (17.6±1.3), (18.2±3.1), (13.0±1.1), (14.0±1.0), (21.0±6.1), (13.6± 3.5), (8.2±1.3) ng/L; VEGF were (88.1±4.1), (85.8±4.3), (58.1±6.3), (56.5±2.4), (87.8±2.8), (57.0±3.7), (34.3±6.7) ng/L; IL-6 were (67.8±4.0), (66.1±3.5), (54.1±4.8), (52.1±3.2), (64.6±4.9), (49.4±4.2), (35.9±3.7) ng/L; IL-8 were (112.8±5.2), (116.6±4.1), (88.0±6.2), (85.5±3.5), (114.4±4.6), (82.6±3.8), (55.9±6.0) ng/L, respectively. The serum concentrations of TGF-β(1), VEGF, IL-6 and IL-8 in group C, D, F and G were significantly lower than those in group A, B and E (all P<0.05). Compared with the other groups, the serum concentrations in group G were the lowest (all P<0.05). All 42 rabbits had tracheal stenosis with different degrees of proliferation of granulation tissue. The degree of tracheal stenosis in Group A, B, C, D, E, F and G were (53.3±4.4)%, (48.2±5.0)%, (24.3±4.4)%, (29.5±3.2)%, (47.8±6.5)%, (27.9±3.1)%, (15.6±2.0)%, respectively. The degree of tracheal stenosis in group C, D, F and G was significantly lower than that in group A, B and E, which had statistical differences (all P<0.05). Compared with the other groups, the degree of tracheal stenosis in group G was the lowest (all P<0.05). Conclusions: Low dose of erythromycin can effectively inhibit the proliferation of granulation tissue after tracheal injury in rabbits. And it has better effectiveness when combined with other antibiotics and hormone.

Disease correction by combined neonatal intracranial AAV and systemic lentiviral gene therapy in Sanfilippo Syndrome type B mice

Mucopolysaccharidosis type IIIB (MPS IIIB) or Sanfilippo Syndrome type B is a lysosomal storage disease resulting from the deficiency of N-acetyl glucosaminidase (NAGLU) activity. We previously showed that intracranial adeno-associated virus (AAV) -based gene therapy results in partial improvements of several aspects of the disease. In an attempt to further correct the disease, MPS IIIB mice were treated at 2–4 days of age with intracranial AAV2/5-NAGLU (IC-AAV), intravenous lentiviral-NAGLU (IV-LENTI) or the combination of both (BOTH). The BOTH group had the most complete biochemical and histological improvements of any treatment group. Compared to untreated MPS IIIB animals, all treatments resulted in significant improvements in motor function (rotarod) and hearing (auditory-evoked brainstem response). In addition, each treatment group had a significantly increased median life span compared to the untreated group (322 days). The combination arm had the greatest increase (612 days), followed by IC-AAV (463 days) and IV-LENTI (358 days). Finally, the BOTH group had nearly normal circadian rhythm measures with improvement in time to activity onset. In summary, targeting both the systemic and central nervous system disease of MPS IIIB early in life appears to be the most efficacious approach for this inherited metabolic disorder.