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Biomedical subjects

Hsian-Jenn Wang

Publications and source records attributed to Hsian-Jenn Wang.

18 recordsLinked to original sources
PubMed2006

Enhanced immune response by amphotericin B following NS1 protein prime-oral recombinant Salmonella vaccine boost vaccination protects mice from dengue virus challenge.

A recombinant vaccine strain SL3261/pLT105 of attenuated aroA Salmonella enterica serovar Typhimurium SL3261 strain expressing a secreted dengue virus type 2 non-structural NS1 and Yersinia pestis F1 (Caf1) fusion protein, rNS1:Caf1, was generated. Immunological evaluation was performed by prime-boost vaccine regimen. Oral immunization of mice with 1 x 10(9)cfu of SL3261/pLT105 only induced low levels of NS1-specific antibody response and protective immunity following dengue virus challenge. The parenteral NS1 protein priming-oral Salmonella boosting protocol enhanced both NS1-specific serum IgG response and protective efficacy as compared to mice immunized with each type vaccine alone. Addition of an antifungal antibiotic amphotericin B (AmB) to Salmonella vaccine further enhanced the synergic effects of prime-boost vaccine regimen on the elicited NS1-specific serum IgG response and the protective efficacy. Together, the results demonstrated that the rNS1:Caf1 producing Salmonella SL3261/pLT105 strain fails to provide effective protection as an oral vaccine alone despite co-administration of AmB as an adjuvant capable of enhancing the immune responses, and moreover, the protein priming-oral Salmonella vaccine boosting approach in combination with AmB as an immunization regimen may have the potential to be further explored as an alternative approach for dengue vaccine development.

Administration, Oral↗
PubMed2006

The distally based sural fasciomusculocutaneous flap for foot reconstruction.

Finding appropriate soft-tissue to cover a wound located over the middle or distal portion of the foot can be challenging. A distally based sural fasciomusculocutaneous flap including the sural nerve and a midline cuff of the gastrocnemius muscle can be used for this purpose. This flap is designed on the proximal third of the posterior calf and is nourished in a retrograde manner by the lower peroneal septocutaneous perforators, through the vascular axis of the sural nerve to the musculocutaneous perforators of the gastrocnemius muscle. Between October of 2002 and January of 2004, this flap was applied in nine individuals, including four diabetic patients. The skin defects all resulted from trauma, osteomyelitis or chronic ulcer, and combined with bone or tendon exposure. One flap developed distal necrosis. The other flaps survived fully and provided good contour. In our series, diabetes mellitus seemed not to compromise the vascularity of the flap. The distally based sural fasciomusculocutaneous flap is very useful for lower limb reconstruction, particularly for the foot, because of its long vascular pedicle and the availability of the skin portion of the proximal calf based on direct branches between the musculocutaneous perforators and the neurovascular axis of the sural nerve. This is an important variant of the sural neurocutaneous flap and it appears to be a good alternative to free flaps for resurfacing the foot.

Diabetic Foot↗
PubMed2006

Experience with elastic rubber bands for the tie-over dressing in skin graft.

We derived a dressing using elastic rubber bands to tie over the skin graft. This is a simple, easy to perform, timesaving, inexpensive and reliable method for applying pressure over the skin graft compared with traditional methods. Between September 2002 and August 2004, we have used the present dressing technique in 35 patients with 36 grafts in various parts of the body. We chose this method, because of some anatomic areas, such as back, and buttock, which are frequently quite difficult to maintain pressure dressings in place, minimal movement can cause the skin graft to dislodge. The elastic rubber bands, rather than threads, are used as tie-over. Such a dressing permits expansion and contraction, providing a dynamic quality in the most difficult anatomic locations. The patient group consisted of 23 males and 12 females. The age ranged from 34 to 82 years (mean 52.4 years). Defect size ranged from 3x2.5 to 30x20 cm2 (mean 11.2x7.0 cm2 in size). The average follow-up was 5.8 months (range: 1-12 months). Among the 36 grafts in our study, all grafts except four showed good to excellent results. The mean graft successful rate is 88%. With our procedure no hematoma formation or shearing force (except one case) occurred in this group of patients during the phase of revascularization, there was, hence, good fixation of the graft by the "tie-over" dressing using elastic rubber bands compared with conventional tie-over dressing, especially in skin grafts of the back site of body and at large graft area. However, it is not suitable for the potentially infectious granulation beds, especially near joint area.

Adult↗
PubMed2006

Secretion of biologically active human epidermal growth factor from Escherichia coli using Yersinia pestis Caf1 signal peptide.

BACKGROUND AND PURPOSE: The Caf1 secretion pathway of Yersinia pestis is one of the most well-characterized export machineries. To facilitate the secretion of human epidermal growth factor (hEGF) in Escherichia coli, a DNA fragment containing the synthetic gene for hEGF was joined to a sequence encoding the signal peptide of Yersinia pestis Caf1 protein. METHODS: The gene for hEGF was synthesized by overlapping polymerase chain reaction technique and was placed under the control of the caf1 gene promoter in the recombinant plasmid pHL401 which was used to transfect E. coli BL-21 for production of hEGF. The biological function of recombinant hEGF was measured by estimating its ability to stimulate the proliferation of human embryonic kidney-293 cells. RESULTS: The results indicated that the expressed hybrid protein was processed during the secretion process. The majority of the mature hEGF was recovered from the periplasm and medium fractions, with a small amount of the expressed hEGF deposited in the cytoplasm. Furthermore, it was found that the cell proliferation was enhanced by the recombinant hEGF. CONCLUSION: These results suggested that the recombinant hEGF was successfully secreted through the inner membrane of cells into the periplasm and then through the outer membrane into the medium via the action of the signal peptide of Y. pestis Caf1 in E. coli. The mitogenic activity of hEGF in cells was demonstrated.

Bacterial Proteins↗
PubMed2005

The application of new biosynthetic artificial skin for long-term temporary wound coverage.

Temporary dressings protect wounds from desiccation and infection. In our previous study, we used meshed acellular porcine dermis (APD) to enhance wound healing and decrease wound contraction; however, the wounds showed meshed scar. In this study, we produced an artificial skin composed of a cross-linked silicon sheet on the surface of APD which we have called silicone acellular porcine dermis (SAPD). This new artificial skin can protect the wound long enough to promote wound healing either by second intention or covered long enough until cultured epithelium autograft (CEA) or autologous skin graft can be harvested for permanent coverage. We delivered 4 cm x 5 cm full-thickness wound on the back of 350 g Sprague-Dawley rats. Thirty-six rats were divided into two groups. Eighteen rats had SAPD and the other 18 were covered with Biobrane. The wounds were first examined 2 weeks after grafting and followed weekly for an additional 4 weeks to evaluate the wound and study pathological changes by using H.E. and Masson's stains. Wound size was calculated by ruler and analyzed by Student's t-test. At the 2-week inspection, both SAPD and Biobrane showed tight adherence to the wound with no change of wound size. Both the SAPD and Biobrane dermal templates were pink. In the Biobrane-covered group, the wounds contracted soon after the tie-over dressing was removed. Its dermal layer is a layer of thin porcine dermal substance, which was promptly digested by tissue hyaluronidase and provides no real dermal template. In the SAPD-covered group however, the wound size was maintained significantly from third to sixth week after grafting (p<0.001). SAPD was designed with thick epidermal silicone and a well-organized porcine dermis so that it incorporates into the recipient wound. Clinically the silicone layer of SAPD dislodged from APD about 6-7 weeks after grafting and was followed by dermal matrix exposure and infection. In pathological examination, much like a human skin graft, new vessels were found in APD about 1 week after grafting with minimal inflammatory cells infiltrated in the graft and wound. Six weeks after grafting, the collagen of APD incorporated into the wound, showing palisade arrangement and no sign of rejection. In the Biobrane group however, the wounds showed severe inflammation, the porcine dermal matrix was digested and disappeared 3 weeks after coverage. In conclusion, SAPD is a thick biosynthetic artificial skin, which protects the rat wound significantly longer than Biobrane and prevents contraction. We expect that using of SAPD for temporary wound coverage will provide enough time to grow autologous-cultured epithelium or to reharvest skin grafts.

Animals↗
PubMed2005

A co-cultured skin model based on cell support membranes.

Tissue engineering of skin based on collagen:PCL biocomposites using a designed co-culture system is reported. The collagen:PCL biocomposites having collagen:PCL (w/w) ratios of 1:4, 1:8, and 1:20 have been proven to be biocompatible materials to support both adult normal human epidermal Keratinocyte (NHEK) and mouse 3T3 fibroblast growth in cell culture, respectively, by Dai, Coombes, et al. in 2004. Films of collagen:PCL biocomposites were prepared using non-crosslinking method by impregnation of lyophilized collagen mats with PCL/dichloromethane solutions followed by solvent evaporation. To mimic the dermal/epidermal structure of skin, the 1:20 collagen:PCL biocomposites were selected for a feasibility study of a designed co-culture technique that would subsequently be used for preparing fibroblast/biocomposite/keratinocyte skin models. A 55.3% increase in cell number was measured in the designed co-culture system when fibroblasts were seeded on both sides of a biocomposite film compared with cell culture on one surface of the biocomposite in the feasibility study. The co-culture of human keratinocytes and 3T3 fibroblasts on each side of the membrane was therefore studied using the same co-culture system by growing keratinocytes on the top surface of membrane for 3 days and 3T3 fibroblasts underneath the membrane for 6 days. Scanning electron microscopy (SEM) and immunohistochemistry assay revealed good cell attachment and proliferation of both human keratinocytes and 3T3 fibroblasts with these two types of cells isolated well on each side of the membrane. Using a modified co-culture technique, a co-cultured skin model presenting a confluent epidermal sheet on one side of the biocomposite film and fibroblasts populated on the other side of the film was developed successfully in co-culture system for 28 days under investigations by SEM and immunohistochemistry assay. Thus, the design of a co-culture system based on 1:20 (w/w) collagen:PCL biocomposite membranes for preparation of a bi-layered skin model with differentiated epidermal sheet was proven in principle. The approach to skin modeling reported here may find application in tissue engineering and screening of new pharmaceuticals.

3T3 Cells↗
PubMed2005

Poly(2-hydroxyethyl methacrylate) wound dressing containing ciprofloxacin and its drug release studies.

An improved wound dressing with a long-term drug diffusion-efficacy has been developed by UV-radiation technique. It involves incorporation of ciprofloxacin (CIP), at the concentration of 0.5-2.0% (w/v), into a water mixture of 2-hydroxymethacrylate (HEMA) monomer, benzoin isobutyl ether (BIE) initiator and different content of ethylene glycol dimethacrylate (EGDMA) cross-linker. Increasing the concentration of EGDMA would reduce the releasing ratio of CIP from pHEMA. T1/2 is increased from 2.64 to 45.67 h when the EGDMA is added from 1 to 8%. In the ranges of 0< or = F < or = 0.6, the n value of 1%CIP-pHEMA membranes is increased from 0.48 to 0.81. It indicates that the mechanism of drug release falls between the Fickian and Case II diffusion model. The antibacterial activity of the drug impregnated into the membrane was evaluated by in vitro drug kinetic agar plate method. Higher concentration of EGDMA, up to 8% of the cross-linker, extends the drug release. Comparison with the drug-soaked membranes, the newly synthesized 1% CIP-pHEMA membrane (cross-linked with 4% EGDMA) sustains the release of the entrapped drug and maintains the antibacterial activity up to 12 days.

Absorption↗
PubMed2005

A seven-year epidemiology study of 12,381 admitted burn patients in Taiwan--using the Internet registration system of the Childhood Burn Foundation.

This study described the epidemiological characteristics of the 12,381 admitted burn patients in Taiwan. The data was from 43 contracted hospitals of the Childhood Burn Foundation, in the years from 1997 to 2003. This descriptive study included 8172 males and 4206 females, with a male to female ratio of 1.94 and an average age of 29.3 years. There were 3993 (33.4%) patients under 18 years old; and 26.4% of the patients were children under 7 years old. First and second years of life were the peak of incidence. The mean extent of burn was 14.0% total body surface area with 950 patients (7.7%) suffering from a burn extent >/=40% TBSA. Scalds resulted in 5085 admissions (43.2%) and flame burns accounted for 3825 admissions (32.5%). In patient group under 18 years old, 76.8% were scald burn and 14.1% were flame burn. The majority of the burn injuries (53.3%) occurred in the dwelling place; 1122 patients had inhalation injuries and required admission to the burn center for pulmonary support. In addition, suicide attempts were recorded in 2.4% (300 cases) of all burn patients with a mean burn size of 40.7% total body surface and mortality rate of 29.3%. The overall mortality rate is 381 out of 12,381 patients (3.1%). The LA(50) was around 80% TBSA. The significant effects of risk factors, such as old age, large burn extent, combined inhalation injury and suicide were demonstrated. Adequate first aid by water cooling affected the outcome of the patient group with burn extent less than 30% TBSA, which was shown by the decrease of length of stay. These results showed some unique distributions that reflected certain socio-economic and cultural background of Taiwan.

Accidents, Home↗
PubMed2005

Free medial sural artery perforator flap for ankle and foot reconstruction.

Resurfacing shallow defects over the ankle and foot with an appropriately thin flap is a common but difficult task. This can be accomplished by harvesting the medial sural artery perforator flap from the medial aspect of the upper calf. Based on the musculocutaneous perforator of the medial sural artery, this flap preserves the medial gastrocnemius muscle and avoids unnecessary flap bulkiness. Between January 2002 and February 2004, we used 2 variants of the free medial sural artery perforator flap for ankle and foot reconstruction in 13 patients (10 fasciocutaneous flaps and 3 adipofascial flaps). In these patients, skin defects were combined with bone, joint, or tendon exposure. The main advantage of this flap is that it provides a thin and pliable coverage to achieve better accuracy in the reconstructive site. Other advantages include maintaining the function of the medial gastrocnemius muscle, providing a long vascular pedicle, and avoiding the need to sacrifice major arteries of the leg. The main disadvantages are the tedious process of intramuscular retrograde dissection of the perforator and the unsightly skin graft over the medial calf.

Adult↗
PubMed2005

Distally based sural fasciomusculocutaneous flap for chronic calcaneal osteomyelitis in diabetic patients.

Chronic calcaneal osteomyelitis is a difficult surgical problem, especially in diabetic patients. After aggressive surgical eradication of nonviable soft tissue and infected bone, there will be a large soft-tissue and bony defect. A distally based sural fasciomusculocutaneous flap including the sural nerve and a midline cuff of the gastrocnemius muscle can be useful for covering the defect. This flap is designed on the proximal half of the posterior calf and has an adequate blood supply derived from retrograde perfusion of the vascular axis of the sural nerve to the musculocutaneous perforators of the gastrocnemius muscle. The patency of the peroneal artery should be confirmed by Doppler ultrasound or angiography before surgery. If there are any vascular problems, this flap will not be used to avoid complications resulting from poor flap circulation. This approach has been used for 11 diabetic patients in the past 2 years. All flaps survived completely and all wounds healed uneventfully. The authors found that the flap was reliable and technically simple to design and execute. This 1-stage procedure not only preserves the major arteries of the injured leg but has also proved valuable for filling bony defect and treating bony infection because it provides a well-vascularized muscle fragment. Compared with other tissue transfers, this flap has special characteristics for use on diabetic patients with chronic calcaneal osteomyelitis.

Aged↗
PubMed2004

Painful fat syndrome in a male patient.

Painful fat syndrome or lipoedema is a distinct clinical condition, characterised by bilateral and symmetrical enlargement of the upper and lower leg with tenderness, but excluding the feet. Lipoedema occurs almost exclusively in females, and no male patient has been reported in the literature published in English. We report on an extremely rare presentation of lipoedema in a male patient. A thorough study based on the case history, physical manifestations, and magnetic resonance imaging (MRI) provided valuable clues for a differential diagnosis. Conservative treatment using weight reduction, compression-stocking application, and diuretic therapy was not effective. Tumescent liposuction with postoperative pressure garments provided a satisfactory treatment.

Adiposis Dolorosa↗
PubMed2004

Split calvarial bone graft for chemical burn-associated nasal augmentation.

The nose is the central part of the face, and constitutes the most prominent projection in facial geometry. This report presents five cases that sustained a chemical burn injury with associated facial mutilation resulting from contact with strong acids. The chemical burn affected the nasal architecture after inflicting a burn injury to the face. Applying bone deriving from a split skull procedure for the nasal projection restoration and the augmentation of the dorsal nose is a feasible undertaking, and the overall result appears satisfactory. A retrospective survey of cases admitted to our clinic from January 1999 to December 2001, inclusively was undertaken and is described below. Split calvarial bone graft procedure for the nasal tip projection reconstruction was performed for five patients, all of whom had sustained chemical burns following assault by strong acid. The disfiguration of the nasal anatomical structure was due to healing from deep burn wounds. The tip became blunt and less protruberant following the arising of cicatricial tightness of the surrounding tissue. Strength and resistance to scar contraction are the first considerations for such implantation when attempting to correct the nasal tip projection. The five female patients sustained a severe chemical burn which involved a surface area ranging from 25 to 60% of total body surface area. The facial mutilation was noted simultaneously with the determination of the extent of the burning injury. A severe burn scar is the typical sequel following a deep chemical burn. Nasal tip projection was restored and a nasal dorsum augmentation procedure with a split calvarial bone graft under an "open" method was used. This particular surgical procedure was able to be used in order to improve the nasal tip projection and resist surrounding scar contracture. The three-dimensional surface structure of the face became more prominent subsequent to the administration of this procedure.

Adult↗
PubMed2004

The management of complicated charcoal contact burns involving deep tissues.

This report describes the management of a charcoal burn involving deep tissues at different anatomic sites. The closure of burn wounds should be considered as a functional and cosmetic outcome whenever possible. Our aim should be to get the soft tissue of the early burned wound closed. A satisfactory result can be achieved if both the functional anatomy and the aesthetic outcome can be kept in mind while planning the management.

Adult↗
PubMed2004

Thin split-thickness toenail bed grafts for avulsed nail bed defects.

Avulsed defect of a fingernail bed is a common injury in acute hand trauma. Insufficient management for this type of nail bed avulsion often leads to an irregular and nonadherent nail. The use of thin split-thickness sterile matrix graft from the great toe for immediate replacement of a nail bed defect can regain a smooth, adherent, and normal-looking nail. Between May of 1998 and December of 2001, we used thin split-thickness toenail bed grafts in 13 fingers of 12 patients with avulsed defects of the nail bed. The end results of this technique were excellent and no deformities occurred in the graft donor area. Thin split-thickness toenail bed graft is a good choice for the treatment of acute nail bed avulsion.

Adult↗
PubMed2004

Sensate first dorsal metacarpal artery flap for resurfacing extensive pulp defects of the thumb.

Finding an appropriate soft-tissue grafting material to close a wound located over the distal phalanx of the thumb, especially the pulp region, can be a difficult task. A sensate first dorsal metacarpal artery flap, mobilized from the dorsum of the adjacent index finger and used as an island pedicle skin flap, can be useful for this purpose. The pedicle includes the ulnar branch of the first dorsal metacarpal artery, the dorsal veins, and the cutaneous branch of the radial nerve. Although this tiny artery is anatomically variable, safe dissection can be achieved by including the radial shaft periosteum of the secondary metacarpal bone and the ulnar head fascia of the first interosseous muscle. This approach has been used for 8 individuals with extensive pulp defects of the thumb over the past 3 years. Skin defects in all patients were combined with bone, joint, or tendon exposure. All flaps survived completely. This 1-stage procedure is reliable and technically simple. It provides sensate coverage to the pulp of the thumb but also avoids nerve repair or more complicated microsurgery.

Adult↗
PubMed2004

Preparation of cross-linked hyaluronic acid film using 2-chloro-1-methylpyridinium iodide or water-soluble 1-ethyl-(3,3-dimethylaminopropyl)carbodiimide.

In order to obtain much slower biodegradable films, which are often required for biomedical applications, we have developed a series of studies on heterogeneous cross-linking of hyaluronic acid (HA) films by using 2-chloro-1-methylpyridinium iodide (CMPI) or 1-ethyl-(3,3-dimethylaminopropyl)carbodiimide (EDC) as cross-linking reagents. From the in vitro degradation rate, we found that EDC cross-linked HA films completely dissolved in PBS at 37 degrees C during the period of 4-6 days. However, CMPI cross-linked HA films showed only a low percentage of weight loss over 30 days. This phenomenon could be explained from the mechanism of reaction between carboxyl group of HA and EDC. The latter reacted with carboxyl group to form an unstable intermediate O-acylurea, which showed a relatively low reactivity and quickly rearranged to form a stable N-acylurea. Thus, most of the EDC-activated carboxyl groups in HA were chemically transferred into N-acylurea or left as unreactive O-acylurea, and only a few of cross-linking bonds were formed between HA. On the other hand, the intermediate obtained from the reaction between carboxyl group and CMPI showed a relatively high reactivity and reacted with the hydroxyl group of the same and/or different molecules of HA to form an inter- and intramolecular esterification. Apparently, CMPI cross-linked HA films have a much higher cross-linking density and constructed a more rigid three-dimensional network. Therefore, it produced HA films, which dramatically increased its enzymatic stability in aqueous solution of hyaluronidase. The obtained results from elemental analyses, FT-IR spectra and NMR spectra also indicate that acylurea groups were introduced into EDC-cross-linked HA films.

Biocompatible Materials↗
PubMed2002

The distally based lesser saphenous venofasciocutaneous flap for ankle and heel reconstruction.

Finding an appropriate soft-tissue grafting material to close a wound located over the ankle and heel can be a difficult task. The distally based lesser saphenous venofasciocutaneous flap mobilized from the posterior aspect of the upper leg, used as an island pedicle skin flap, can be useful for this purpose. The vascular supply to the flap is derived from the retrograde perfusion of the accompanying arteries of the lesser saphenous vein. These arteries descend along both sides of the lesser saphenous vein to the distal third of the leg, either terminating or anastomosing with the septocutaneous perforators of the peroneal artery. Between February of 1999 and March of 2001, four variants of this flap were applied in 21 individuals, including 11 fasciocutaneous, five fascial, three sensory, and two fasciomyocutaneous flaps. Skin defects among all patients were combined with bone, joint, and/or tendon exposure. The authors found that the flap was reliable and technically simple to design and execute. This one-stage procedure not only preserves the major arteries and the sural nerve of the injured leg, but it also has proved valuable for covering a weight-bearing heel and filling a deep defect, because it potentially provides protective sensation and a well-vascularized muscle fragment. When conventional local flaps are inadequate, this flap should be considered for its reliability and low associated morbidity.

Adult↗