Inhibition effect of mannose-6-phosphate on expression of transforming growth factor Beta receptor in flexor tendon cells.

Transforming growth factor beta (TGF-ß) has an important role in tendon healing and adhesion formation. Inhibiting TGF-ß and its receptor expression may prevent adhesions after tendon open. The goal of this study was to examine the effects of mannose-6-phosphate, a natural inhibitor of TGF-ß, on TGF-ß and its receptor production in tendon sheath fibroblasts, epitenon tenocytes, and endotenon tenocytes of rabbit flexor tendons. Tendon sheath fibroblasts, epitenon tenocytes, and endotenon tenocytes were isolated from rabbit flexor tendons and cultured separately. The cells were divided into 2 groups at random: an experiment group supplemented with mannose-6-phosphate and a control group without mannose-6-phosphate. The expression of TGF-ß and TGF-ß receptor was quantified with enzyme-linked immunosorbent assay. The luciferase assay measured TGF-ß bioactivity. Transforming growth factor beta expression in the experimental group was not decreased compared with the control group, with no significant difference (P>.05) Transforming growth factor beta receptor expression in the experiment group was significantly lower than that in control group (P<.05). Mannose-6-phosphate significantly decreased the expression of TGF-ß receptor and TGF-ß bioactivity. Modulation of mannose-6-phosphate levels may provide a means of modulating the effects of TGF-ß on adhesion formation in flexor tendon wound healing.

Inhibition of TGF-ß-induced collagen production in rabbit flexor tendon with mannose-6-phosphate in vitro.

The flexor tendon affects postoperative range of motion in the hand. Transforming growth factor-beta (TGF-ß) is a key cytokine in the adhesion formation between the flexor tendon and its surrounding fibro-osseous sheath. The purpose of this study was to examine the inhibition of TGF-ß-induced collagen-I production in rabbit flexor tendons with mannose-6-phosphate in vitro. Sheath fibroblasts, epitenon tenocytes, and endotenon tenocytes from rabbit flexor tendons were isolated and each was supplemented with TGF-ß along with increasing doses of mannose-6-phosphate. The enzyme-linked immunosorbent assay (ELISA) and reverse-transcription polymerase chain reaction (RT-PCR) measured collagen-I production. The luciferase assay measured TGF-ß bioactivity. Results were compared with TGF-ß alone and unsupplemented controls. TGF-ß-induced collagen-I production was downregulated significantly with the addition of mannose-6-phosphate in a dose-dependent manner in all 3 cells cultures. The mannose-6-phosphate also reduced TGF-ß bioactivity. The study shows that mannose-6-phosphate was effective in TGF-ß inhibition in cultured flexor tendon cells. The findings presented here encourage further experiments that use the agents to modulate TGF-ß levels and reduce adhesion formation after flexor tendon repair.

99Tcm-DISIDA hepatobiliary imaging in evaluating gallbladder function in patients with spinal cord injury.

BACKGROUND: Spinal cord injury (SCI) is associated with increased prevalence of gallstones and acute acalculous cholecystitis. A possible explanation for the increased prevalence of gallstones in SCI patients is decreased gallbladder motility causing gallbladder stasis. In this study, we investigated gallbladder function in patients with SCI. METHODS: Eighteen normal controls, 16 trauma controls and 46 SCI patients were included in this study. Gallbladder function was measured by technium 99m-labeled imino-diacetic acid analogue ((99)Tc(m)-DISIDA) hepatobiliary imaging and represented by filling fraction (FF) and ejection fraction (EF). The data from SCI patients were analyzed according to old versus young, female versus male, heavy versus light body weight, ASIA A & B versus ASIA C & D classification, high- versus low-level injury, and long versus short injury duration. RESULTS: Fifty-two percent of SCI patients had abnormal FF and 59% had abnormal EF. Significantly decreased FF and EF values were found in SCI patients, especially in female patients with severe and high-level injuries. CONCLUSION: Quantitative (99)Tc(m)-DISIDA cholescintigraphy showed that SCI can significantly impair gallbladder function.

Effects of chitosan on cell proliferation and collagen production of tendon sheath fibroblasts, epitenon tenocytes, and endotenon tenocytes.

OBJECTIVE: To study the proliferation and collagen production of tendon sheath fibroblasts, epitenon tenocytes, and endotenon tenocytes; and the effects of chitosan on cell proliferation and collagen production in the 3 cell types of rabbit flexor tendon. METHODS: Three cell lines of tendon sheath, epitenon, and endotenon were isolated from rabbit flexor tendon and cultured. Cell culture media was added with chitosan. The cell number and production of collagens I, II, and III were measured and compared with those cultured without chitosan. The expression of type I collagen in tendon sheath fibroblasts was determined by quantitative analysis of reverse-transcription polymerase chain reaction. RESULTS: All 3 cell lines produced collagens I, II, and III. Adding chitosan to cell media resulted in a significant decrease in cell number in all 3 cell lines. In addition, there was a significant decrease in collagens I, II, and III production in all 3 cell lines as well as the expression levels of type I collagen in tendon sheath fibroblasts (P<0.05). CONCLUSIONS: Chitosan can inhibit cell proliferation and collagen production of the tendon sheath, epitenon, and endotenon, and may provide a promising approach to obviating tendon adhesion formation clinically.

Spinal cord injury and cholelithiasis.

BACKGROUND: Spinal cord injury (SCI) is found to be related to increased prevalence of gallstones and acute acalculous cholecystitis. In this study we assessed the prevalence of cholelithiasis in male patients with SCI and the correlation of cholelithiasis with age and weight of patients, level of injury, as well as severity and duration of SCI. METHODS: One hundred male SCI patients (58 patients rated ASIA A or B and 42 rated ASIA C or D) aged more than 20 years (average 46.5 years) suffered from a spinal cord injury for more than one year. One hundred male volunteers served as controls without SCI and biliary diseases(age range 20-68 years; average 42.6 years). The two groups were subjected to ultrasonography of the gallbladder and biliary tract. RESULTS: The prevalence of cholelithiasis in the group of SCI patients and the control group was 26% and 10% respectively. Significant differences in the prevalence of cholelithiasis were found between the normal controls and SCI patients and between high and low-level injury (P<0.01). But the differences were not statistically significant when correlating the presence of cholelithiasis with the age and weight of the patients, the duration of SCI, and the severity of spinal lesion(P>0.05). CONCLUSIONS: SCI represents a major risk factor for the development of cholelithiasis,especially in patients with high-level injury. Cholelithiasis in SCI patients is not related to their age and weight, the severity of spinal lesion, and the duration of spinal cord injury.