Investigation of the factors affecting foamability and foam stability of cold brew coffee.

BACKGROUND: In this study, the foamability and foam stability of nitrogen-infused cold brew coffee, as affected by coffee variety (Arabica and Robusta), degree of roast (light, medium, dark), brewing temperature (4, 20, 35 °C), brew ratio (1:5-1:15 w/w; coffee/water), ground particle size (712, 647 and 437 µm volume mean diameter) and beverage temperature (4, 20 and 35 °C), were investigated. RESULTS: Dynamic surface tension of cold brew, as determined from bubble tensiometry, decreased from 65-70 mN m-1 to about 60 mN m-1 as the bubble lifetime increased from 0.1 s to 1 s. Infusing the cold brew coffee (70 mL) with nitrogen gas for 30 s at 50 mL min-1 generated 30-40 mL of foam head. At the same degree of roast, brews prepared from Arabica beans had more stable foam than those from Robusta. Foam stability increased with increasing degree of roast, increasing brewing temperature, decreasing particle size, and decreasing the beverage temperature. By contrast, brew ratio had relatively less effect on foaming properties. Nitrogen-containing constituents present in the 80% (v/v) ethanol-soluble fraction (55.9% of total dissolved solids) of the brew samples were important contributors to foaming, while the 80% (v/v) ethanol-insoluble fraction (42.3% of total dissolved solids) that contained polysaccharides was important in stabilizing the foam. CONCLUSION: The foamability and foam stability of cold brew coffee are significantly affected by coffee variety, degree of roast, brewing temperature, ground particle size, and beverage temperatures. The foam properties are dictated by the low-molecular-weight nitrogen-containing compounds and high-molecular-weight polysaccharides present in the cold brew coffee. © 2022 Society of Chemical Industry.

[Different effects of simvastatin on keloid fibroblasts under hypoxia and TGF-ß1 treatment].

Objective: To explore the effect of simvastatin on the proliferation, apoptosis and protein expressions of keloid fibroblasts under normoxia,hypoxia or TGF-ß1 treatment. Methods: Keloid fibroblasts (KFs) were isolated by explants culture method. KFs were treated with different concentrations of simvastatin under normoxia or hypoxia (2％ O2) for 24 h and 48 h. The effects of simvastatin on cell proliferation were detected by CCK-8.Flow cytometer was used to detect the apoptosis of KFs treated with 10 µ mol/L simvastatin for 24 h or 48 h under normoxia, hypoxia or 10 ng/ml TGF-ß1 treatment. Then the expressions of keloid-related proteins were analyzed by Western Blot. Results: It showed that simvastatin could inhibit the proliferation of KFs in a concentration-and time-dependent manner with the concentration range of 10-500 µ mol/L for 24 h and 0.1-500 µ mol/L for 48 h. This inhibitory effect could be significantly enhanced when cells were incubated under hypoxia for 48h with 10-500 µ mol/L simvastatin.10 µ mol/L simvastatin could not influence the apoptosis of KFs under normoxia or TGF-ß1 treatment, neither incubated for 24 h nor 48 h.When incubated under hypoxia,10 µ mol/L simvastatin could significantly induce the apoptosis of KFs, with the rate of 155.6％ for 24 h and 478.8％ for 48 h, compared with no-drug control. There are no significant influences on the expression of type Ⅰ collagen, CTGF or TIMP-1 when KFs were treated with 10 µ mol/L simvastatin under normoxia for 48 h. When incubated with 10 ng/ml TGF-ß1 together with 10 µmol/L simvastatin for 48 h, the expression of CTGF was significantly inhibited. KFs treated with 10 µ mol/L simvastatin under hypoxia for 48 h showed a significant decrease of type Ⅰ collagen and CTGF, and a significant increase of TIMP-1. Conclusions: Simvastatin has different effects on the proliferation, apoptosis and protein expressions of KFs in a dosedependent manner under different conditions. The effects are enhanced under hypoxia.

[Mitochondrial dysfunctions of keloid fibroblasts and it' s effects on cell metabolic functions].

Objective: To compare the differences of mitochondrial functions between keloid fibroblasts and normal skin fibroblasts and explore its relationship with cell proliferation. Methods: Keloid fibroblasts (KFb) and normal skin fibroblasts (NFb) were isolated by explants culture method. KFb and NFb were cultured under normoxia or hypoxia (2％ O2).Differences of cell proliferation were detected by CCK-8.Flow cytometer was used to detect the content of mitochondria and reactive oxygen species (ROS) in KFb and NFb. Ultra-structures of mitochondria in KFb and NFb were observed by transmission electron microscope (TEM).Mitochondria fusion/fission related genes MFN1,MFN2 and FIS1 were detected by RT-PCR. Oxygen consumption rate, lactate production and ATP contents were determined by spectrophotometry. Results: KFb showed a higher proliferation rate compared with NFb, especially under hypoxia. The oxygen consumption rate, ATP content, lactate production and ROS of KFb were lower than NFb under normoxia. After incubated under hypoxia, there was a significant increase in oxygen consumption, ATP content, lactate production and ROS in KFb, while NFb showed less increase compared with KFb. KFb had 15.33％ more mitochondrion than NFb, and expressions of MFN1, MFN2, FIS1 in KFb were 33.27％,113.39％ and 20.34％ higher compared with NFb. Under TEM, KFb showed an increase of enlarged mitochondrion, with disrupted inner membrane and loss of cristae. Conclusions: KFb may have dysfunctions of mitochondrion which lead to changes of cell metabolism and continuous proliferation of KFb.

[Treatment of post-traumatic chronic calcaneal osteomyelitis and soft tissue defect by using combined muscle and skin flaps of calf].

OBJECTIVE: To investigate the effectiveness of distally pedicled peroneus brevis muscle flaps and reverse sural neurovascular island flaps for post-traumatic chronic calcaneal osteomyelitis and soft tissue defects. METHODS: Between January 2008 and January 2012, 9 patients suffering from post-traumatic chronic calcaneal osteomyelitis and soft tissue defects were treated, including 8 males and 1 female with an average age of 33 years (range, 18-46 years). The left heel was involved in 4 cases, and right heel in 5 cases. Infection occurred after reduction and internal fixation of closed fractures of the calcaneus in 7 cases, and open calcaneal fracture and soft tissue defect in 2 cases. The disease duration was 2 months to 3 years (mean, 5 months). Purulent secretion, tissue necrosis, or sinus formation was observed in all wounds. The results of bacterial culture were positive. X-ray and CT examination showed uneven density of calcaneus and bone cavity or dead bone formation. After thorough debridement, the size of bone defect ranged from 3 cm x 3 cm x 3 cm to 6 cm x 4 cm x 3 cm; the size of soft tissue defect ranged from 7 cm x 3 cm to 12 cm x 7 cm. The distally pedicled peroneus brevis muscle flaps (11 cm x 3 cm-16 cm x 4 cm) were used for bone defect repair, and reverse sural neurovascular island flaps (8 cm x 4 cm-14 cm x 8 cm) for soft tissue defect. The donor site was directly sutured in 6 cases and repaired by skin graft in 3 cases. RESULTS: After operation, reverse sural neurovascular island flaps survived in 9 cases, and all wounds healed by first intention. No necrosis or liquefaction of distally pedicled peroneus brevis muscle flaps was observed. Incision at donor site healed by first intention, and skin grafts at donor site survived. All cases were followed up 6-24 months (mean, 13.5 months). The flaps had good texture. No recurrence of osteomyelitis was observed. Basic weight-bearing walking function was restorated. No obvious calcaneal collapse happened. CONCLUSION: The distally pedicled peroneus brevis muscle flap combined with reverse sural neurovascular island flap is one of the effective methods to treat post-traumatic chronic calcaneal osteomyelitis with soft tissue defect, with the advantages of simple operation and good blood supply.

Repairing proximal and middle lower-leg wounds with retrograde sartorius myocutaneous flap pedicled by perforating branches of medial inferior genicular artery or posterior tibial artery.

BACKGROUND AND OBJECTIVES: The blood supply of the lower one-third of the sartorius muscle is mainly provided by the descending genicular artery (saphenous artery). The terminal branches of the saphenous artery, together with the perforators of the posterior tibial artery and medial inferior genicular artery, form a stable and rich anastomotic network in the genus inferior medialis. Based on this anatomy, we designed a retrograde sartorius myocutaneous flap to repair wounds in the proximal and middle thirds of the lower leg. METHODS: A sartorius myocutaneous flap with the posterior tibial (or medial inferior genicular) artery perforators as the pedicle was designed. The flap was based on a retrograde flow route: medial inferior genicular and posterior tibial artery perforators, the vascular network at the inferomedial knee, the saphenous artery, saphenous artery perforators, to the sartorius muscle. With this design, the flap can be transferred to the middle and proximal tibia. Between January 2007 and June 2010, 12 patients with middle/proximal lower-leg wounds were successfully treated with this method. RESULTS: Ten of 12 myocutaneous flaps survived with primary healing of wounds. Two cases developed a small degree of distal superficial skin necrosis but with normal muscular blood supply and healed after conservative treatment. CONCLUSION: Retrograde sartorius myocutaneous pedicle flaps from the perforating branches of the medial inferior genicular artery or posterior tibial artery have advantages in terms of reliable blood supply, ease of operation and minimal amount of damage, and can be used to repair proximal and middle lower-leg wounds. They are especially applicable when lower-leg flaps are unavailable due to poor soft-tissue conditions following trauma or multiple operations. However, the safety flap size needs to be determined in future studies.

[Early treatment of high-voltage electric burn wound in the limbs].

OBJECTIVE: To summarize the experience of early treatment of high-voltage electric burn wounds in the limbs. METHODS: Fifty-four patients (50 males and 4 females, aged from 10 to 56 years) with high-voltage electric burn wounds in 97 limbs (67 upper limbs and 30 lower limbs) were hospitalized in our burn wards from January 2003 to December 2010. A total of 119 burn wounds in wrist-forearm, forearm-elbow-upper arm, shoulder-axillary region, ankle-foot, lower leg, around the knee, thigh-inguinal region were treated with incision for decompression within 10 days after burn. Under the premise of relatively stable systemic condition of the patients, certain surgical operations were performed as follows. (1) Sixteen limbs with 16 wounds were amputated, among them forearm amputation was performed for 5 upper limbs with necrosis, with preservation of elbow joints, and the residual wounds of the elbow and upper arm were repaired with pedicled latissimus dorsi musculo-cutaneous flaps; 1 upper limb with upper arm amputated, with preservation of shoulder joint, was repaired with pedicled latissimus dorsi musculo-cutaneous flap. (2) Ninety-five wounds were covered with various tissue flaps with abundant blood supply after early debridement, in which 3 brachial arteries, 1 vein, 1 brachial artery and vein were reconstructed in 5 wrist wounds, artery reconstruction was performed in elbow wound of 1 case with injured brachial artery. (3) Eight wounds were treated with free skin grafting. Wound healing conditions were observed and followed up. RESULTS: Wounds in 16 limbs healed after amputation and repair. Blood supply and (or) venous return of hands were restored in 5 wrist wounds after vessel reconstruction. After artery reconstruction, abundant blood supply was observed in 1 case with injured brachial artery and amputation was avoided. Necrosis occurred in distal parts of tissue flaps in 5 wounds after grafting, in which 2 wounds healed after removal of necrotic tissue followed by closure with suture, and 3 wounds healed after debridement and free skin grafting. Tissue flap infection occurred in wrist (5 wounds), elbow (1 wound), ankle-foot (2 wounds), and healed after debridement and suture. The other tissue flaps survived after grafting. Six wounds healed after skin grafting. Partial necrosis occurred in 2 wounds after skin grafting, and they were healed after second skin grafting. Thirty-seven patients were followed up for 6 to 12 months, the skin flaps survived with satisfactory appearance and texture. CONCLUSIONS: Early extensive compartment release through fasciectomies and escharectomies, early debridement, early vascular grafting, early wound coverage with contemporary reparative and reconstructive surgical techniques are rational options for the treatment of high-voltage electric burns in the limbs.

[Characterization and biological significance of peripheral blood dendritic cell subsets in patients with severe burn].

OBJECTIVE: To investigate the characteristics of dendritic cells (DCs) in patients with severe burn. METHODS: Peripheral blood samples were obtained from 12 patients with severe burn 1, 2, 3, and 4 weeks after burn, and from 10 healthy donors as controls. Mononuclear cells were isolated, and GM-CSF 1000 and IL-4 were used to induce the transformation of DCs. Mature DCs were harvested and underwent flow cytometry to detect the expression of HLA-DR, CD80, CD83, CD86, CD14, and CD11c. RESULT: 1, 2, 3, and 4 weeks after burn, the expression levels of HLA-DR were 62.1% +/- 8.4%, 65.0% +/- 6.2%, 68.4% +/- 5.7%, and 75.4% +/- 8.4% respectively; the expression levels of CD80 were 12.9% +/- 3.7%, 14.7% +/- 2.5%, 16.1% +/- 4.2%, and 16.2% +/- 4.8%; the expression levels of CD83 were 15.1% +/- 4.2%, 15.1% +/- 4.0%, 22.2% +/- 7.7%, and 21.3% +/- 7.0% respectively; the expression levels of CD86 were 69.2% +/- 7.1%, 70.5% +/- 5.4%, 75.1% +/- 6.1%, and 79.6% +/- 6.4% respectively, all significantly lower than that of the control group (84.3% +/- 8.2%, all P < 0.001). 1, 2, 3, and 4 weeks after burn, the expression levels of CD14 in the DCs of the severe burn patients were 12.7% +/- 1.9%, 12.0% +/- 1.5%, 11.3% +/- 1.3%, and 9.3% +/- 1.7% respectively, all significantly higher than that of the control group (7.3% +/- 1.5%, P < 0.001). 1, 2, 3, and 4 weeks after burn, the expression levels of CD11c in the DCs of the severe burn patients were 86.8% +/- 6.1%, 89.5% +/- 5.1%, 91.3% +/- 2.8%, and 89.4% +/- 4.0% respectively, a little lower than that of the control group, however, without significant difference (92.6% +/- 3.8%, P > 0.05). CONCLUSION: The functions of DCs in the patients with severe burn are declined, which may partly contribute to infection after burn.

[Preliminary study on the improvement of wound microcirculation and retrospection on several methods of the management of deep partial thickness burn wound].

OBJECTIVE: To analyze several methods of wound repair for deep partial thickness burn wounds retrospectively, so as to evaluate the significance of improvement of wound microcirculation on wound healing. METHODS: (1) 2,976 burn patients admitted to our department were enrolled in the study, among them 614 undertook tangential excision, 32, eschar abrasion, 86 allo-skin coverage after debridement, 1836 tropical application of silver sulfadiazine and 408 with traditional Chinese medicine (Jing Wan Hong ointment) with gauze bandage. The results of the management with different methods were compared. (2) Rat model with deep partial thickness burn was reproduced and topical application of silver sulfadiazine was given. The rats were randomly divided into control (n = 10, with normal saline injected via caudal vein within 5 minutes postburn), and treatment (n = 10, with batroxobin injected via caudal vein within 5 minutes postburn) groups. The blood flow perfusion unit in the wound skin was measured before burn and at 0.5 to 72 postburn hours by Laser Doppler. The wound healing rate, contraction rate and wound healing time in each group were calculated on 14 and 18 postburn days (PBDs). The number of hair follicles after wound healing was observed by histological method. RESULTS: (1) The burn wound treated by tangential excision healed within 2 to 3 post operation weeks (POWs), with the healing rate of 94.8% in patients with burn covering 50% - 70% TBSA and 93.4% in those with burn of 80% approximately 98% TBSA. The healing time of patients with allo-grafts coverage after eschar abrasion was 13.8 +/- 2.1 days without scar formation. The wound healing time was 18.0 +/- 2.3 day in 82 patients with allo-graft coverage after debridement, and it was 26.0 +/- 3.2 days with subeschar healing in 1658 patients with topical application of silver sulfadiazine. Infection in burn wound was encountered in most patients undergoing traditional Chinese medicine bandage treatment with wound healing time of 26.0 +/- 2.8 days in the lower extremities. (2) The blood flow perfusion unit of the rats in the treatment group was significantly higher than that in the control group (P < 0.01). The wound healing rate in treatment group on 14 and 18 PBD was obviously higher than that in the control group (P < 0.01). But the wound contraction rate in the two groups was similar (P > 0.05). The wound healing time in treatment group was much shorter than that in control group (P < 0.01). A few hair follicles remained in the dermis of the rats in the control group on 30 PBD, and the number was evidently smaller than that in the treatment group (P < 0.01). CONCLUSION: Early tangential excision and eschar abrasion remained better methods in the management of deep partial thickness burn wounds, as they could ameliorate burn wound infection, shorten treatment period, raise wound healing rate and quality. Application of batroxobin could accelerate wound healing rate by improving wound microcirculation in deep partial thickness burn wound.

[Experimental and clinical study on the treatment of ischemic skin flap with topical application of PGE1].

OBJECTIVE: To evaluate the efficiency of PGE(1) in relieving the circulatory disorder of ischemic skin flap. METHODS: New Zealand rabbits were employed in the study with skip flaps each with the size of 2.5 x 6.0 cm(2) being raised from the back. PGE(1) cream in different concentrations, i.e. 0.2%, 0.4%, 0.8% was respectively topically applied to the skin flaps forming 3 groups (n = 10 in each group), while pure cream without PGE(1) was applied to those in control group (n = 30). The PGE(1) was applied 1 hour after the flap was opened, raised and sutured back. Blood perfusion in the flap was measured with Laser Doppler flowmetry before and 5, 10, 15, 20, 30, 45 and 60 mins after PGE(1) application. The tissue samples from the skin flap were harvested at 2 hours after PGE(1) application for immunohistological staining, and the cross sectional area of capillary lumens was measured under microscope. The survival area of the flap was assessed on the 3(rd) day after operation for the calculation of relative survival length of the flap. Clinically, PGE(1) ointment was applied onto the skin flap vulnerable to necrosis, and the outcome of the flap was observed thereafter. RESULTS: The blood perfusion in animal skin flaps was increased evidently after PGE(1) application, especially at 30 mins after PGE(1) usage when compared with that in control group (P < 0.05). The capillaries in the skin flap in PGE(1) application groups were dilated obviously after drug usage as observed under microscope (P < 0.05). The survival area and relative survival length in groups 1 and 2 on the 3(rd) post-operational day were much more increased when compared with those in other groups (P < 0.01). Clinically, the skin flaps treated with PGE(1) survived well even in the distal end of the flaps. CONCLUSION: The blood perfusion and the survival rate of the skin flaps could be improved by local application of PGE(1) in concentrations of 0.2% or 0.4%.