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Biomedical subjects

R E Horch

Publications and source records attributed to R E Horch.

At least 55 records · Page 3Linked to original sources
PubMed2001

Metastatic malignant acrospiroma of the hand.

We present the case of a 37-year-old man with multiple pulmonary metastases of a primarily unknown primary tumour. Thorough revision of the medical history yielded that he had already passed three resections of a right palmar mass, which had been described as a benign tumour. Clinical examination showed a thickened scar with a suspicious palpable mass in the right hand. Excision of this scar and the tumour mass with histopathological examination now revealed a malignant acrospiroma. Resection of the pulmonary metastases histologically also confirmed a malignant acrospiroma. The following radical resection of the metacarpals II and III with the index and middle finger under the assumption of a wide compartment resection achieved tumour free margins and proved to be efficient with the patient being relapse free for 4 years from this operation. Although the prognosis of this tumour is generally unfavourable this particular case demonstrates the value of a radical surgical resection as the mainstay of treating such highly malignant sweat gland tumours of the hand.

Adult↗
PubMed2001

Plasmid gene delivery to human keratinocytes through a fibrin-mediated transfection system.

We have developed a matrix-mediated transfection system to deliver plasmids to human keratinocytes. The matrix is a soluble, self-hardening fibrin matrix (Tissucol), Baxter) that has been used clinically. Recently it has been shown that full thickness burn wounds can be successfully treated with a keratinocyte fibrin glue suspension. Further, it has been demonstrated that hEGF transfected cells accelerate wound healing. In this study, we inoculated the matrix with the hEGF expression plasmid and resuspended the matrix with either cultured or noncultured human keratinocytes. We obtained successful transfection rates of these cells (up to a 100-fold increase compared to controls containing no EGF expression plasmid) in vitro. After transplantation to full thickness wounds on athymic mice we were able to show a 180-fold increase in EGF concentration compared to controls, which persisted over the entire 7-day monitored period, decreasing from 180 to 20 pg/mL at day seven. This unique approach indicates the possible utility to combine a matrix for cell transplantation with a transfection system to release therapeutic proteins in vitro and in vivo.

Animals↗
PubMed2000

The contralateral bilobed trapezius myocutaneous flap for closure of large defects of the dorsal neck permitting primary donor site closure.

BACKGROUND: Various reliable local flaps can be used to cover soft tissue defects of the posterior neck. Among others, the (either vertical or transverse) trapezius myocutaneous flap is a reliable option in this context. However, for defects with a diameter larger than 15 cm, these flaps require skin grafting of the donor site. METHODS: To prevent this additional morbidity we describe a contralaterally based bilobed trapezius musculocutaneous flap successfully applied in two elderly patients with large tumors of the posterior neck in palliative situations. RESULTS: This novel approach makes use of a standard vertical skin paddle to cover the neck, together with a transverse cervical flap in a bilobed design to primarily close the paravertebral donor site. CONCLUSIONS: The bilobed technique allows the primary closure of massive soft tissue neck wounds. Preservation of the accessory nerve to the superior fibers of the trapezius muscle permitted normal arm elevation in our patients.

Accessory Nerve↗
PubMed2000

Hemangiosarcoma of the left hand in a patient with the rare combination of Maffucci's and Stewart Treves syndrome.

We describe a patient with the previously unseen combination of Maffucci's and Stewart Treves syndrome who presented with an angiosarcoma of the hand. Maffucci's syndrome is characterized by the presence of multiple enchondroma and soft tissue hemangioma. The syndrome is a rare nonhereditary condition with a usual onset in childhood. Malignant transformations are a common feature of this syndrome. In 1948, Stewart and Treves first described six cases of lymphangiosarcoma after radical mastectomy. This syndrome is an unusual form of angiosarcoma occuring as a complication of lymphedema. Chronic lymphedema and lymphangiectasia preceding lymphangiosarcoma may not only be induced by radical mastectomy with axillary lymph node dissection and postoperative radiation therapy. Posttraumatic, congenital or spontaneous chronic lymphedema may also be associated with lymphangiosarcoma. A time interval of many years seems to be required before malignant transformation develops. Generally the syndrome has a very poor prognosis. Both syndromes described above are of a rare frequency. We report this case because of prior unknown coincidence of both syndromes.

Amputation, Surgical↗
PubMed2000

Cultured human keratinocytes on type I collagen membranes to reconstitute the epidermis.

The development of new techniques and modifications to overcome some of the disadvantages in cultured keratinocyte grafting has been motivated by several well-known drawbacks in the use of cultured epithelial autografts such as long culture periods, lack of adherence, difficulty in handling, lack of dermal substrates, and high costs. Two recent insights have influenced further research. On the one hand, it has been shown that the use of undifferentiated proliferative cells in fibrin glue suspensions is effective in epithelial reconstitution. On the other hand, the enzymatic release of cells from the culture surfaces is a critical step leading to at least temporary destruction of anchoring structures of the cultured cells. In this study, we tried to combine these two aspects in an attempt to modify common modalities of keratinocyte transplantation. To avoid dispase dissolving of the cultured cells, keratinocytes were seeded onto bovine collagen type I membranes without feeder layers and under serum-free culture conditions. Subconfluent monolayers of cultured human keratinocytes were transplanted as an upside-down graft on collagen membranes (keratinocyte collagen membrane grafts [KCMG], n = 12) after 3 days of culture or as membrane grafts alone (n = 12) onto standard nude mice full-thickness wounds. Fully differentiated epidermis was found at 21 days after grafting KCMG with persistence of human keratinocytes. This study demonstrates that upside-down grafts of undifferentiated monolayers of keratinocytes on non-cross-linked bovine type I collagen membranes do lead to an early reconstitution of multilayered squamous epithelium with enhanced wound healing compared to the control group. The upside down KCMG grafting technique is able to transfer actively proliferative keratinocytes and simplifies the application compared to conventional epithelial sheet grafting.

Animals↗
PubMed2000

Rapid aggressive soft-tissue necrosis after beetle bite can be treated by radical necrectomy and vacuum suction-assisted closure.

BACKGROUND: The substance cantharidin, which is produced by a type of beetle, rapidly penetrates the epidermis and can cause severe toxicities such as skin necrosis. Optimal treatment for necrotic beetle bites has not been well defined. Conservative management has been advocated but the hospital stays are long and long-term morbidity may result, especially in multimorbid patients. OBJECTIVE: The value of aggressive surgical management of such necrotizing diseases using newly developed surgical tools is compared to the traditional more conservative approach. RESULTS: We present the case of a multimorbid 60-year-old man with a rapidly progressive necrosis of the medial thigh (measuring 30 X 15 cm), acquired during a stay in Western Africa after being bitten by a beetle of the species Cantharide. The patient was treated with radical surgical debridement and continuous elimination of the wound fluid by permanent computer-controlled negative pressure with a vacuum-assisted wound-closure device. This led to the sudden relief of both local and systemic symptoms and allowed extremely early wound closure. CONCLUSIONS: Comparing literature data with the course of this combined treatment, we strongly suggest an early aggressive management with complete radical excision of necrotic tissue, conditioning of the wound bed by temporary suction-assisted vacuum closure and subsequent skin grafting with continued vacuum application. This treatment leads to immediate relief of pain and enhanced healing of this lesion even in the condition of immunosuppression in the elderly.

Animals↗
PubMed2000

[Gene therapy perspectives in modulation of wound healing].

A variety of reasons can afflict wound healing. Current research is focussed on the acceleration of wound healing by stimulating molecular processes. Gene therapy may offer completely new ways to treat chronic wounds. Possible advantages of gene therapeutic modulation of wound healing might be a long term efficiency, systemic or local regulation of gene expression and low side-effects. Current goals comprise the improvement of transfection efficiency and specificity. In vivo applications are therefore focussed on optimized inducible or even cell-type specific promotors, as well as on improved local application techniques. Studies from our laboratory demonstrate the possibility to combine modern cell culture techniques with different types of gene transfer. This enables the simultaneous grafting of manipulated cells to the wound with the continuous delivery of specific proteins of interest. Experimentally, this lead to accelerated closure of partial and full thickness animal wounds. Clinically, gene therapy for the treatment of chronic wounds seems to be a realistic goal within the next years and might be applicable for a variety of novel indications.

Animals↗
PubMed2000

[Treatment of chronic wounds with cultured autologous keratinocytes as suspension in fibrin glue].

Cultivated keratinocytes have been used for treatment of chronic wounds. Our group developed a new application form, using a suspension of subconfluently cultivated keratinocytes in fibrin glue (keratinocyte-fibrin-glue-suspension = KFGS), which has successfully been used in burn patients. Altogether 8 patients (average: 57 yrs.) with complex chronic wounds of different origin were treated with KFGS. All wounds, which had been existing from 4 months to 14 years, showed good reepithelization. Up to now there has been observed stable wound closure for 4 years after grafting. This study demonstrates the wound healing potency of a keratinocyte-fibrin-glue-suspension also for chronic wounds. Fibrin glue seems to be both an ideal application vehicle as a biological matrix for the cultivated keratinocytes. The transplantation of cultivated autologous keratinocytes as suspension in fibrin glue is a promising way in the treatment of chronic wounds.

Adult↗
PubMed1999

[Quality of life after breast reduction-plasty].

We have investigated the improvement in the quality of life in 384 breast reduction patients within a seven-year postoperative follow-up. Through the use of a questionnaire (recall of n = 223 patients), we sought to establish the patient's most compelling reason for seeking this surgical procedure. In addition, the effect of the operation on the patient's quality of life was investigated. Preoperatively, the main complaint was pain in the shoulder girdle in 77% of the patients, followed by 67% patients suffering from lower and thoracic back pain symptoms, whereas 51% defined mastodynia as their primary complaint. 95% of the patients noted a remarkable improvement in the quality of their professional and social lifes. 94% were able to specify this improvement as an increase in the feeling of self-esteem, 53% showed up with amelioration of selfconfidence. 95% of the patients felt that the breast reduction had a positive influence on their sexual behaviour and personal relationships. Our study reveals that breast reduction surgery offers not only an aesthetic improvement but also the relief of preoperative pain and discomfort, leading to important improvements in the patient's quality of life.

Adolescent↗
PubMed1999

The rectus abdominis free flap as an emergency procedure in extensive upper extremity soft-tissue defects.

Stable wound coverage after extensive soft-tissue loss of the upper extremity remains a difficult problem in the management of large defects of the upper limb. To prevent further tissue loss owing to infection or inadequate cover when important structures such as vessels, tendons, nerves, joints, and bones are exposed, various free flaps have been introduced into the therapeutic armamentarium of acute plastic surgical management options. Emergency or delayed early reconstruction has been proposed to prevent chronic infection and further tissue loss. We report a series of 12 emergency and delayed early reconstructions of the forearm, wrist, carpus, metacarpus, and hand using the free rectus abdominis muscle flap with split-skin coverage, demonstrating the versatility of this flap within this special context. Emergency free rectus muscle flap transfer is safe, technically easy, and expandable.

Abdomen↗
PubMed1999

[Keratinocyte transplantation and tissue engineering. New approaches in treatment of chronic wounds].

Cultured keratinocytes have been used for the treatment of extensive burns since disease lethality is reduced. Consequently, the treatment of chronic wounds with keratinocytes may be promising. Cell culture technology allows to expand keratinocytes up to 6000-fold in vitro after taking a single biopsy from patient. Today the transplantation of these in vitro cultured keratinocytes in different modifications is an established clinical treatment regimen for therapy of extensive wounds. For example, keratinocyte-fibrin-glue-suspensions, mainly consisting of proliferative epidermal basal cells, were used for the treatment of burns in experimental and clinical settings to bypass the disadvantages of conventional sheet grafts. Other approaches in tissue engineering for wound healing aim at the (epi-)dermal repair by the combination of allodermis and biomaterials, i.e. collagen-sponges and microspheres. Due to most recent efforts in keratinocyte culture techniques, developments in tissue engineering, research for novel biomaterials and gene therapy, therapy of chronic wounds may prove to be more efficient. Furthermore, from the socio-economical point of view, overall costs for treatment of chronic wounds could be reduced.

Cell Division↗
PubMed1998

Comparison of the effect of a collagen dressing and a polyurethane dressing on the healing of split thickness skin graft (STSG) donor sites.

Recent advances in the resurfacing of burn wounds with dermal equivalents and collagen preparations have shown the efficacy of collagen. To investigate the benefits (if any), standardised split skin donor areas were chosen to compare the influence of collagen on re-epithelialisation. A bovine collagen preparation consisting of type-I collagen was prospectively compared with polyurethane film dressing in a study of 20 split thickness skin graft donor sites. The rates of epithelialisation, the discomfort experienced by the patients and the convenience of the dressings were assessed. The median time from operation to the observation of complete healing was 7.5 (+/- 2.5) days for the donor sites dressed with the collagen membrane and 12.5 (+/- 3.4) days for the the donor areas dressed with a polyurethane film (p < 0.001). The discomfort experienced by the two groups of patients was significantly less after wound coverage with collagen (p < 0.005). Haematomas or seromas that required repeated aspiration was seen under the polyurethane film dressing. The collagen dressing was more expensive than the polyurethane film, but improved wound healing compared with the polyurethane dressings.

Collagen↗
PubMed1998

Preexpansion of the tensor fasciae latae for free-flap transfer.

Preexpansion has become an established technique to prefabricate elective free flap transfers. We report the use of the tensor fasciae latae flap as a donor site in two cases for reconstruction of a burn scar neck contracture and an unstable contralateral below-knee amputation stump, of which other donor sites were ruled out either by the patients' condition or by choice. Implantation and transfer were straightforward and the donor sites of very large flaps were minimized by preexpansion. The preexpanded muscle fasciocutaneous flaps were transplanted with microsurgical anastomoses of the vessels. Apart from a small area of necrosis at the distal tip of the flap developing on the sixth postoperative day, which we excised in a second operation, there were no major complications. The advantages of the combination of preexpansion and free flap transfer as well as the unique anatomical and functional qualities of this musculocutaneous unit are emphasized.

Adult↗
PubMed1998

[Biological wound tissue glue systems in wound healing].

Tissue engineering relies on in vitro cell culture, biocompatible matrix materials and genetic engineering with growth and differentiation factors for guided tissue regeneration. Biogenic or semisynthetic biomaterials are an alternative as cell carriers: To circumvent the disadvantages of conventional keratinocyte sheet grafts, a keratinocyte fibrin glue suspension KFGS (H. W. Kaiser et al., Burns 20: 23, 1994), which mainly consists of epidermal stem cells, has been tested experimentally in nude mice and clinically in extensive burns and chronic wounds. In the "in vivo culture" on the wound, the non-confluent keratinocytes form a differentiated epithelium within days. Current research aims at guided dermal regeneration by a combination with allodermis or biomaterials (collagen sponges like TissueFaszie, Microspheres etc.). Fibrin glue (Tissuecol) has also been tested successfully as matrix for other cells like chondrocytes and fibroblasts transfected with growth factor genes (EGF/KGF).

Animals↗
PubMed1997

Median nerve compression can be detected by magnetic resonance imaging of the carpal tunnel.

OBJECTIVE: Clinically symptomatic carpal tunnel syndrome is not necessarily accompanied by impaired nerve conduction values. Surgical decompression, however, may immediately lead to complete and lasting relief of symptoms in these patients. Because minimally invasive techniques have reduced perioperative morbidity and vocational impairment related to operative decompression, the decision to decompress symptomatic patients (despite still unimpaired nerve conduction values) might be subject to discussion in the future. New diagnostic tools may be helpful in deciding which therapeutical options to choose. When the wrist is held either in flexion or in extension, the carpal tunnel pressure increases. To investigate the dynamic changes of the carpal tunnel shape during wrist motion, as well as the variations of space for the median nerve and its signal intensity in T2-weighting, magnetic resonance imaging (MRI) was performed on patients and healthy volunteers alike. Restitution and the persistence of pathological findings were assessed pre- and postoperatively. METHODS: MRI (1.0 T) was performed on 20 wrists of patients with clinical symptoms of carpal tunnel syndrome (CTS) and pathological nerve conduction values. Healthy volunteers (20 wrists) were matched according to sex and age. MRI was performed in neutral, 45-degree extension, and 45-degree wrist flexion positions. T2-weighted signal intensity of the median nerve was measured in 18 patients pre- and postoperatively. RESULTS: The cross-sectional area of the carpal tunnel in patients with CTS tends to be smaller than that found in nonsymptomatic volunteers. The cross-sectional area of the carpal tunnel decreases during wrist flexion at the pisiform and hamate level. During wrist extension, the cross-sectional area of the carpal tunnel decreases at the level of the pisiform. During extension, it increases at the level of the hamate. The cross-sectional area of the median nerve showed an increase at the pisiform level (P < 0.05), a flattening of the median nerve at the hamate hook level (P < 0.05), and palmar deviation of the flexor retinaculum at the pisiform and hamate hook level (P < 0.001). This was significantly greater in CTS patients than in individuals with normal wrists. Postoperatively, the distal flattening of the median nerve recovered in 94% of the cases reviewed. Although the signal intensity of the median nerve on T2-weighted images decreased by 67%, the motor latency recovered in only 39% of the cases. CONCLUSION: The carpal tunnel was smaller in CTS patients than in healthy volunteers. During flexion and extension, the space available for the median nerve narrows. This may lead to potential median nerve compression. MRI is accurate and reliable for diagnosis and postoperative follow-up of carpal tunnel syndrome. In cases with obvious clinical symptoms and yet not measurably impaired median nerve conduction values, it may be helpful in making a decision for surgical decompression.

Adult↗
PubMedDate not supplied

Effect of ultrasonic assisted lipectomy (UAL) on breast tissue: histological findings.

As the use of ultrasound-assisted liposuction (UAL) increases, the technique grows more popular in breast surgery, especially in reduction mammaplasty and treatment of gynecomastia. The aim of our study was to investigate the effect of UAL on breast tissue using histological examinations, and analyze the effect of this technique on a cellular level. Biopsies from 10 patients undergoing ultrasonically assisted lipectomy prior to classic reduction mammaplasty were taken from the treated areas of the breast. Biopsies were fixed in formalin and embedded in paraffin. Sections were stained with hematoxilin-eosin, and analyzed for defective adipocytes, and the effects of UAL on breast tissue. Untreated breast tissue and breast tissue that had been treated only with conventional aspiration lipectomy served as controls. Sections were analyzed using light microscopy. Compared to the breast tissue treated only with conventional lipectomy, a stronger destruction of the cellular structure of adipocytes could be detected. The destruction was visible even in areas more distant from the aspiration channel. In contrast, the breast tissue was mostly intact, no signs of ultrasonic-induced cellular destruction were visible. The glandular structure was kept intact. Beside the direct mechanical destruction by the probe and the canula, no further alterations of the cellular integrity of the glandular parts were visible. In conclusion our results indicates that UAL is also a safe technique for use in breast surgery. Besides easy handling and improved modelling, the destructive effect of the ultrasound does not include the glandular breast tissue.

Breast↗