Current therapies for myocardial infarction and congestive heart failure are limited in efficacy or in applicability. The plasticity of adult stem cells and cellular transplantation offer a novel therapeutic approach to improve cardiac function. This review describes the latest progress in research, summarizes recent studies of adult stem cells and their application in myocardial regenerative medicine in China and abroad, and discusses the future directions of cell transplantation as a new therapy to repair injured hearts. (J Geriatr Cardiol 2004;1(2) :77-82. )

AIM:To investigate the role of minocycline on glutamate uptake in the periventricular zone and its putative mechanism after hypoxic exposure in neonatal rats.METHODS: A model of hypoxic-ischemic brain damage (HIBD) was developed by putting postnatal 1 d rat pups in 5%O2 for 3.5 h.The glutamate level in periventricular zone was measured by liquid chromatography coupled with tandem mass spectrometry assay ( LC-MS/MS) after hypoxic exposure for 4 h and 1 d.The dynamic changes of glutamate transporters EAAT1, and EAAT2 during developmental period in periventricular zone were determined by Western blot.Moreover, the expression of EAAT1, EAAT2, Iba-1, IL-1β, TNF-αand TGF-β1 was also detected by Western blot after hypoxic exposure for 4 h and 1 d in that region.The effects of mino-cycline on all parameters mentioned above were tested after minocycline treatment at the same time points and in the same region.RESULTS:After hypoxic exposure, glutamate level was increased, but it was decreased after minocycline treat-ment.EAAT1 and EAAT2 kept a low expression level at the first postnatal week, but a predominant elevation was found at the end of the second postnatal week.The expression of EAAT1, EAAT2, Iba-1, IL-1βand TGF-β1 was increased at 1 d after hypoxic exposure.EAAT1 and TNF-αexpression was significantly up-regulated, while EAAT2 was down-regulated af-ter minocycline treatment.CONCLUSION: Minocycline inhibits the increase in the glutamate level after hypoxia in periventricular region of the neonatal rats.The mechanism may relate to the selective regulation of glutamate transporters, rather than the inhibition of neuroinflammation in periventricular zone.

Objective To investigate the potential of adult mesenchymal stem cells (MSCs) derived from human bone marrow to undergo cardiomyogenic differentiation after exposure to 5-azacytidine (5-aza) in vitro. Methods A small bone marrow aspirate was taken from the iliac crest of human volunteers, and hMSCs were isolated by 1.073g/mL Percoll and propagated in the right cell culturing medium as previously described. The phenotypes of hMSCs were characterized with the use of flow cytometry. The hMSCs were cultured in cell culture medium (as control) and medium mixed with 5-aza for cellular differentiation. We examined by immunohistochemistry at 21 days the inducement of desmin, cardiac-specific cardiac troponin I (cTnI), GATA 4 and connexin-43 respectively. Results The hMSCs are fibroblast-like morphology and express CD44+ CD29+ CD90+ / CD34- CD45- CD31- CD11a. After 5-aza treatment, 20-30% hMSCs connected with adjoining cells and coalesced into myotube structures after 14days. Twenty-one days after 5-aza treatment, immunofluorescence showed that some cells expressed desmin,GATA4, cTnI and connexin-43 in 5,10 μmol/L 5-aza groups, but no cardiac specific protein was found in neither 3μmol/L 5-aza group nor in the control group. The ratio of cTnI positively stained cells in 10 μmol/L group was higher than that in 5 μmol/L group (65.3 ± 4.7% vs 48.2 ± 5.4%, P ＜ 0.05). Electron microscopy revealed that myofilaments were formed. The induced cells expressed cardiac-myosin heavy chain (MyHC) gene by reverse transcription-polymerase chain reaction (RT-PCR). Conclusions Theses findings suggest that hMSCs from adult bone marrow can be differentiated into cardiac-like muscle cells with 5-aza inducement in vitro and the differentiation is in line with the 5-aza concentration. (J Geriatr Cardiol 2004;1(2) :101-107. )

Objective: To observe the clinical application effect of blood circulation enhancement technique in repairing large area of skin and soft tissue defects of extremities with super large free anterolateral thigh flap. Methods: From March 2014 to March 2017, 6 patients with large area of skin and soft tissue defects of extremities were hospitalized in our unit, including 5 males and 1 female, aged 27-65 years, 1 case of electric injury, 2 cases of coal burn, 3 cases of traffic injury, 2 cases involving upper limb, and 4 cases involving lower limb. After debridement, the wound area ranged from 26 cm×8 cm to 36 cm×15 cm, and the bone exposure area ranged from 24 cm×7 cm to 35 cm×14 cm. The blood circulation enhancement technique was used when the wound with bone exposure was repaired with super large free anterolateral thigh flap. The area of flaps ranged from 28 cm×10 cm to 38 cm×16 cm. The donor site of flap and the primary wound without bone exposure were repaired with medial thigh split-thickness skin graft of the donor leg of flap. The blood circulation enhancement technique mode during operation and the survival of flaps after operation were recorded, and the recovery of donor and recipient areas and the occurrence of complications were followed up. Results: Three patients were treated with simple vascular supercharging technique during flap transplantation, and the other 3 patients were treated with vascular supercharging and turbocharging technique during flap transplantation. All the flaps survived well in 6 patients without vascular crisis. Follow-up for 3 to 12 months after surgery showed that the blood flow of the flaps was good and the depth and superficial sensation recovered to varying degrees. Except for 1 case of upper limb flap, the other flaps had no obvious swelling and needed no second thinning. There were only depressed scars in the donor sites, and no obvious scar hyperplasia in the area without bone exposure repaired by the skin grafts. No short-term or long-term complications were found. Conclusions The application of blood circulation enhancement technique in repairing large area of skin and soft tissue defects of extremities with super large free anterolateral thigh flaps provides reliable blood supply for the flaps and results in good effect after operation, which is worth popularizing.

Objective: To observe the effects of axial vascular network flap of scalp or anterolateral thigh perforator flap with fascia lata on repairing defects after radical resection of scalp carcinoma in patients. Methods: From February 2006 to December 2015, twenty-one patients with scalp carcinoma were admitted to our hospital, and the carcinoma invaded external lamina or full-thickness of skull and dura mater. After perfect preoperative examination, carcinoma and scalp tissue in 3 to 5 cm from the edge of carcinoma, external lamina or full-thickness of skull and invaded dura mater were resected and sentinel lymph nodes around carcinoma were cleaned in 3 to 4 days after admission. The postoperative defects with size reached from 11 cm×8 cm to 22 cm×18 cm. The flap transplantation was performed at the same time when quick frozen pathological examination results of resected scalp carcinoma margin tissue, skull, dura mater margin and basal tissue, and sentinel lymph nodes showed completely negative. Defects in 3 elderly patients were repaired by single or multiple axial scalp vascular network flaps, with the resected flaps size ranged from 12 cm×7 cm to 19 cm×14 cm. Defects in the other 18 patients were repaired by anterolateral thigh perforator flaps with fascia lata, with the resected flaps size ranged from 13 cm×10 cm to 23 cm×19 cm and the resected fascia lata size ranged from 8 cm×7 cm to 10 cm×10 cm. The head donor site of flap was repaired by medium thickness skin of head and back; the thigh donor site of flap was repaired by medium thickness skin of thigh on the same side. All patients gave up postoperative radiotherapy, chemotherapy, and other follow-up treatments. Results: After operation, the flap and skin in all patients survived completely, with no vascular crisis or other condition. During the follow-up for 6 months to 9 years, all patients showed good appearance except for baldness in operation area of head, with no obvious malformation in head donor site of flap and skin, no swollen external hernia in the brain tissue, and no local recurrence or distant metastasis of carcinoma. The appearance of thigh donor site of flap and skin was good, with normal muscle strength and movement of lower limbs. Conclusions Patients with scalp carcinoma were performed with radical resection of carcinoma, and axial vascular network flap of scalp or anterolateral thigh perforator flap with fascia lata were applied to repair the postoperative defects, with good appearance of head operation area and no local recurrence or distant metastasis of carcinoma.

Objective: To investigate the clinical effects of perforating branch flaps of medial vastus muscle in repairing secondary wounds in donor sites of free anterolateral femoral perforator flaps. Methods: From August 2014 to December 2016, 12 patients (8 males and 4 females, aged 35-72 years) with skin and soft tissue defects of extremities associated with tendon and bone exposure were treated in Hanzhong Central Hospital. The sizes of the primary wounds after debridement were 10 cm×8 cm-22 cm×14 cm, and the wounds were repaired with 12 cm×10 cm-24 cm×16 cm free anterolateral femoral perforator flaps. The anterolateral femoral donor sites, which were 8.0 cm×4.0 cm-14.0 cm×7.5 cm in the secondary wounds after skin extensional suture, were repaired with perforating branch flaps of medial vastus muscle in the size of 9.0 cm×5.0 cm-15.0 cm×8.5 cm. The medial femoral donor sites were sutured directly. Results: All the perforating branch flaps of medial vastus muscle and free anterolateral femoral perforator flaps survived in 12 patients. Following up for 6 to 12 months, the medial femoral perforator flaps had good local shape and texture. The flaps of 8 patients without cutaneous nerve transection were sensitive. The sensation of the flaps of the other 4 patients gradually recovered, and the functions of the ipsilateral knee joints were normal. Conclusions The medial femoral perforator flap has a stable anatomy and abundant blood supply, which can be used to repair the secondary wound in the donor site of the free anterolateral femoral perforator flap conveniently. It is safe and easy to be popularized. Moreover, it has a good shape and function after operation.

Objective To investigate the therapeutic effects of bone marrow mesenchymal stem cells (BMSCs) for radiation-induced lung injury (RILI) and the underlying mechanism. Methods Forty-five healthy adult male C57BL/6 mice were randomly divided into control, model, and BMSCs groups. The model and BMSCs groups received a single irradiation dose of 20 Gy to the chest, while the control group did not receive X-ray irradiation. For the BMSCs group, an injection of 1 × 10⁶ BMSCs cells was administered via the tail vein within 6 h after irradiation. In the 5th week, the lung tissue was taken to observe pathological changes with HE staining; examine the expression of the inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) with immunohistochemical staining; observe the polarization of macrophages with immunofluorescence staining; and measure the expression of the epithelial-mesenchymal transition markers E-cadherin, N-cadherin, and vimentin proteins by Western blot. Results After radiation, the model group developed pulmonary vasodilation and congestion with septal thickening and inflammatory cell infiltration, and these changes were markedly reduced in the BMSCs group. The model group showed significantly down-regulated expression of IL-6 and TNF-α compared with significantly increased levels in the model group (P < 0.01, P < 0.05). Treatment with BMSCs significantly increased the polarization of lung macrophages towards the M2 type, while significantly decreasing the abnormally increased N-cadherin and vimentin levels in RILI mice (P < 0.05, P < 0.01). Conclusion BMSCs have therapeutic effects for RILI mice, which may be through promoting macrophage polarization from M1 to M2.

Objective To investigate the role of hydrogen therapy in reducing radiation-induced lung injury and the specific mechanism. Methods Forty C57BL/6 mice were randomly divided into four groups: normal control group, model group, hydrogen therapy group I, and hydrogen therapy group II. A mouse model of radiation-induced lung injury was established. The pathological changes in the lung tissue of the mice were examined with HE staining. Immunofluorescence staining was used to detect the expression of surface markers of M1 and M2 macrophages to observe macrophage polarization. The expression of interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and IL-10 in the lung tissue was measured by immunohistochemistry. The expression of nuclear factor-kappa B (NF-κB) p65 and phosphorylated NF-κB (P-NF-κB) p65 was measured by Western blot. Results HE staining showed that compared with the control group, the model group exhibited alveolar septal swelling and thickening, vascular dilatation and congestion, and inflammatory cell infiltration in the lung tissue; the hydrogen groups had significantly reduced pathological damage and inflammatory response than the model group, with more improvements in hydrogen group II than in hydrogen group I. Immunohistochemical results showed that compared with those in the control group, the levels of the inflammatory cytokines IL-6 and TNF-α were significantly increased in the model group; the hydrogen groups showed significantly decreased IL-6 and TNF-α levels and a significantly increased level of the anti-inflammatory factor IL-10 than the model group, which were more marked in hydrogen group II than in hydrogen group I. Immunofluorescence results showed that compared with the control group, the expression of the surface marker of M1 macrophages in the model group was significantly upregulated; the hydrogen groups showed significantly downregulated M1 marker and significantly upregulated M2 marker, and hydrogen group II showed significantly increased M2 marker compared with hydrogen group I. Western blot results showed that compared with that in the control group, the ratio of P-NF-κB p65/NF-κB p65 in the model group was significantly increased; the P-NF-κB p65/NF-κB p65 ratio was significantly reduced in the hydrogen groups than in the model group, and was significantly lower in hydrogen group II than in hydrogen group I. Conclusion Hydrogen inhalation therapy may reduce the inflammatory response of radiation-induced lung injury by inhibiting the NF-κB signaling pathway to promote the polarization of the macrophage M1 subtype to the M2 subtype.