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Biomedical subjects

B Hoffmeister

Publications and source records attributed to B Hoffmeister.

At least 19 recordsLinked to original sources
PubMed2006

In vitro antibacterial activity of Lucilia sericata maggot secretions.

Maggots of the green blowfly, Lucilia sericata, are used as an alternative to surgical intervention and long-term antiseptic therapy for the treatment of chronic wounds. The secretions of maggots are known to have antibacterial properties. To quantify the bactericidal effect of secretions from larvae of L. sericata, an in vitro test model based on the modified European quantitative suspension test (EN 1040) was developed, in which a co-culture of maggots and bacteria (Micrococcus luteus,Escherichia coli, methicillin-sensitive Staphylo-coccus aureus) in tryptic soy broth was tested. The numbers of bacterial colonies with and without maggot exposure were compared after 24, 48 and 72 h of exposure. The mean log(10) reduction factor (RF) for bacterial elimination per maggot was >4 at all examined times for all tested bacteria. Thus, maggot secretion fulfilled the required definitions of an antiseptic. In addition, the maggots' ability to ingest bacteria was also evaluated. Maggots contained viable bacteria after 48 h of contact with the respective organisms. These maggots also continued excreting bacteria. Therefore, maggots should be disposed of after use as they must be regarded as medical waste.

Animals↗
PubMed2003

Oesophageal squamous cell neoplasia in head and neck cancer patients: upregulation of COX-2 during carcinogenesis.

Patients with (previous) head and neck cancer (HNC) are at high risk for developing second squamous cell cancer of the oesophagus. The role of cyclooxygenase-2 (COX-2) in oesophageal squamous carcinogenesis has not yet been investigated in this high-risk group. Therefore, this study examined COX-2 mRNA and protein expression in oesophageal biopsies and resected tissues of 44 HNC patients. The evaluation covered 55 oesophageal tissue samples (18 invasive oesophageal squamous cell cancers, four high- and eight low-grade dysplasias, 25 normal squamous epithelia) from the 44 patients. mRNA levels of COX-2 were measured by real-time PCR using a LightCycler. COX-2 protein expression was studied immunohistochemically and graded by a staining score. COX-2 mRNA was detected in all samples, and its levels correlated positively with the immunohistochemical staining score (P<0.05). COX-2 expression was upregulated during oesophageal squamous carcinogenesis in HNC patients, that is COX-2 expression increased significantly from normal oesophageal squamous epithelium to low- and high-grade dysplasia and finally to invasive squamous cell cancer (P<0.001). Our findings suggest that COX-2 upregulation contributes to oesophageal squamous carcinogenesis in HNC patients. Prospective studies are needed to evaluate the chemopreventive potential of COX-2 inhibitors in this high-risk group.

Base Sequence↗
PubMed2003

[Clinical and molecular genetic observations on families with cherubism over three generations].

BACKGROUND: Cherubism is a rare fibro-osseous disorder that almost exclusively affects the maxilla and mandible. CASE REPORT: We report on three affected males in three generations in family A, and ten affected patients in family B. The youngest affected relative in family A also had craniosynostosis. His father and grandfather had cherubism and clubbed fingers. RESULTS AND DISCUSSION: Cherubism was mapped to region 4p16.3. Because of the associated craniosynostosis, we excluded the FGFR3 gene as a candidate gene for cherubism. The inheritance pattern is autosomal dominant with variable expression. The penetrance is 100% in males and 50-70% in females. We found incomplete penetrance in males, which does not conform with all publications.

Adolescent↗
PubMed2003

Implant-supported titanium prostheses following augmentation procedures: a clinical report.

BACKGROUND: This report describes a novel technique for fabricating retrievable implant-supported titanium (Ti) prostheses in patients requiring a comprehensive treatment plan involving the combined efforts of maxillofacial surgery and implant prosthodontics. METHODS: Following bone graft reconstructive surgery and implant placement prosthetic treatment was initiated by inserting ITI-Octa abutments. An impression was made, and a framework was fabricated by fusing Ti-cast frameworks to prefabricated titanium copings by laser-welding. This was followed by veneering or fabrication of a removable denture with Ti metal re-enforcement. RESULTS: Favourable clinical results have been achieved using these screw-retained Ti implant-supported restorations for patients treated with reconstructive bone graft-surgery, with clinical observation periods ranging from three to four years. CONCLUSIONS: The present observations suggest that these screw-retained implant-supported Ti prostheses may be a meaningful contribution to implant prosthodontics, facilitating retrievable restorations of optimum biocompatibility, good marginal precision and with a good esthetic result. However, controlled clinical studies are needed to establish the long-term serviceability of these Ti restorations.

Adult↗
PubMed2002

Screening for oesophageal neoplasia in patients with head and neck cancer.

Due to advanced disease at the time of diagnosis the prognosis of oesophageal cancer is generally poor. As mass screening for oesophageal cancer is neither feasible nor reasonable, high-risk groups should be identified and surveilled. The aim of this study was to define the risk of oesophageal cancer in patients with (previous) head and neck cancer. A total of 148 patients with (previous) head and neck cancer were prospectively screened for oesophageal cancer by video-oesophagoscopy and random oesophageal biopsies. Even in a macroscopically normal looking oesophagus, four biopsy specimens were taken every 3 cm throughout the entire length of the squamous oesophagus. Low- or high-grade squamous cell dysplasia was detected histologically in 10 of the 148 patients (6.8%). All but one dysplasias were diagnosed synchronously with the head and neck cancers. In addition, oesophageal squamous cell carcinoma was diagnosed in 11 of the 148 patients (7.4%). Most invasive cancers (63.6%) occurred metachronously. The risk of squamous cell neoplasia of the oesophagus is high in patients with (previous) head and neck cancer. Surveillance is recommended in this high-risk group.

Aged↗
PubMed2000

[Primary thinning and de-epithelialization of microsurgical transplants from the lateral thigh].

To expand the indicational spectrum of the myocutaneous vastus lateralis flap, which is often too voluminous for intraoral application, we performed extreme, primary thinning of the fat and muscle component of this microsurgical transplant in 14 patients. After subfascial localization of the 0.5- to 1.0-mm-thick perforating vessel, it is exposed through the fascia and muscles up to its exit from the descending branch of the lateral circumflex femoral artery. After isolating the perforating vessel, it is no longer necessary to include parts of the vastus lateralis muscle in the flap. The fatty tissue of the remaining epifascial fat component is completely removed except for a ca. 1- to 2-cm-wide cuff of fatty tissue and fascia around the perforating vessel. When performing this primary radical removal of the subcutaneous fatty tissue, care should be taken not to injure the deep subdermal vascular plexus. In addition to the thinning procedure, de-epithelialization of the skin was performed using scalpel blade dissection (five patients) or carbon dioxide laser (6 W, five patients). This thinning technique was used for covering ten intraoral and four extraoral defects and enabled the raising of skin flaps with a thickness of 3-5 mm even in obese patients. The vessel pedicle length of thinned flaps was between 12 and 16 cm; flap size varied between 4 x 5 and 9 x 15 cm, and the donor sites were directly closed. In one case, there was a partial necrosis (20%), but the remaining flaps healed without complications. On the intraoral flaps, a thin, smooth and pliable surface developed after re-epithelialization within 3-6 weeks. The described method expands the application possibilities of the myocutaneous vastus lateralis flap for a large number of intraoral and flat defects with minimal donor-site morbidity.

Adipose Tissue↗
PubMed2000

Primary thinning of the myocutaneous vastus lateralis flap.

To expand the indicational spectrum of the myocutaneous vastus lateralis flap, which is often too voluminous for intraoral application, primary thinning of the fat and muscle component of this microsurgical transplant was performed in 14 patients. The surgical technique includes subfascial localization of at least one myocutaneous perforating vessel of the lateral circumflex femoral artery and its dissection through the fascia, muscles and fatty tissue up to the skin. The epifascial fatty tissue is completely removed except for a 1-2 cm wide cuff around the perforating vessel. The thinning technique was used for covering 10 intraoral and 4 extraoral defects and enabled the raising of skin flaps with a thickness of 4 mm even in obese patients. The vessel pedicle length of the thinned flaps was between 12 and 16 cm; flap size varied between 4x5 and 9x15 cm and the donor sites were directly closed. In one case, there was a partial necrosis (20%), but the other flaps healed without complications. The described method allows the raising of thick myocutaneous as well as thin skin flaps from the same donor region.

Adipose Tissue↗
PubMed1999

Immunohistochemical examination of an orbital alveolar soft part sarcoma.

BACKGROUND: A 32 year-old male patient had a 6-week history of left-sided proptosis. Computer tomography revealed a 16x15x15 mm smooth and well-defined mass between the optic nerve and the medial and superior rectus muscles in the left orbit. METHODS: The tumour was excised via a cranio-medial orbitotomy approach. RESULTS: Histopathological examination, immunohistochemistry and electron microscopy findings were consistent with an alveolar soft part sarcoma. Immunohistochemical staining showed positive immunoreactivity for neuronespecific enolase, vimentin, p53 (30%), p21 (10%) and cyclin D1 (20%), and negative immunoreactivity for CD45, cytokeratins, S-100 protein, glial fibrillary acidic protein, synaptophysin, chromogranin, calcitonin, serotonin, thyreoglobulin, desmin, myosin, actin, HMB-45, pRB, p16 and BCL-2. The growth fraction of the tumour cells was 3%. At examination 4 years after surgical excision, there was no evidence of local recurrence or for metastases. CONCLUSION: Alveolar soft part sarcoma of the orbit is a rare malignant tumour best controlled by surgery. The unpredictable behaviour of these neoplasms, however, indicates the need for long-term follow-up.

Adult↗
PubMed1999

Elastic fibers in the human temporo-mandibular joint disc.

The elastic fiber content of 12 articular discs, removed from 12 patients with complete anterior or medio-anterior disc displacement, was examined. Eight to 12 sagittal sections (3 microm each) were acquired for each disc and stained with modified resorcin-fuchsin for visualization of elastic fibers. The program "CUE-2 Image Analyzer Morphometry" digitized all sections with 800x magnification, calculated the elastic fiber content and reconstructed it 3-dimensionally. The calculated volume density of the entire disc was a mean x(tot)= 0.339 +/- 0.060% of the total tissue. The highest fiber content of 2-4% was found in the posterior area at the transition to the bilaminar zone. 61% of the elastic fibers were located in the bilaminar zone, 10% in the posterior, 2% in the intermediary and 26% in the anterior band. There were substantially more fibers in the cranial part of the posterior region and at the medial edge as compared to the mean fiber distribution of the posterior band and the bilaminar zone. A third of these fibers were found in the inferior layer, particularly in the lateral part. Exactly the opposite fiber distribution was seen in the anterior band. The fibers frequently appeared in the caudal layer, especially in the lateral periphery, but there were fewer fibers in the medial cranial layer.

Adolescent↗
PubMed1997

[Raising a radial flap with primary wound closure by prefabrication of split skin fascia flaps].

A disadvantage of the radial forearm flap is the removal of skin from a functionally important and aesthetically exposed region. To minimize the donor site morbidity with this flap, we have thus far used a two-phase procedure for intraoral defect coverage in 15 patients: In a first step, a 0.5-mm split thickness skin graft is transplanted to the forearm fascia and settles there over a period of 2 weeks. In step two, the prefabricated fascial-split thickness skin graft can be raised with complete preservation of the forearm skin and microsurgically transferred like a conventional radial forearm flap. We have obtained the following results with this procedure: (1) All skin grafts took completely on the forearm fascia. (2) Prefabricated fascial-split thickness skin flaps could be raised like conventional radial forearm flaps. (3) The very thin and moldable flaps were excellently suited for intraoral lining and showed complication-free healing. We conclude that tension-free, primary closure of the donor site can be achieved with minimal aesthetic and functional impairment.

Forearm↗
PubMed1997

[Synovial chondromatosis (chondrometaplasia). Contribution to the differential diagnosis of temporomandibular joint diseases].

A rare case of synovial chondromatosis of the temporomandibular joint with unspecific symptoms is presented. This causes difficulties in classifying the different clinically and technically acquired features at differential diagnosis. The concept of chondrometaplasia as being triphasic and self-limiting is strongly supported and extreme care should be taken during therapy in order to avoid any unnecessary destruction and mutilation. This case seems to indicate that chronic parafunctional overload was the initiating stimulus for this reactive metaplastic process. Nonphysiologic overstrain of any cause should be diagnosed and corrected.

Adult↗
PubMed1996

Experience with the osteocutaneous fibula flap: an analysis of 24 consecutive reconstructions of composite mandibular defects.

Based on findings from anatomical dissections of the skin of the peroneal artery, we used the osteocutaneous fibula flap for combined replacement of the mandible and floor of the mouth in 24 patients, form November 1993 to December 1995. There were 22 primary and 2 secondary reconstructions; the mean age of the patients (2 women and 22 men) was 64 years. The length of the fibula segments ranged between 5.5 and 18 cm, the size of the skin component between 3 x 5 and 6 x 15 cm. Corresponding to the results of our anatomical studies, the skin island was exclusively raised form the distal third of the lower leg, and the donor sites were generally covered with split thickness skin grafts. The average length of the dissected vascular pedicle was 11 cm, so that a vein graft was only required in one case. Flap raising and tumour resection were always carried out simultaneously. Fibula osteosynthesis was done with titanium miniplates; the insertion of endosseous implants followed secondarily. The success rate was 95.8% with one transplant loss and pseudarthrosis in one case. Despite the limited width of the fibula, the shape of the mandible was satisfactorily reconstructed in all patients, and the thin, pliable component enabled intraoral coverage with only negligible surplus volume. Chronic wound-healing disturbances at the donor site of the skin island occurred in two cases; impairment of walking ability was not detected. According to our experience, the use of the osteocutaneous fibula flap is a valuable method for the reconstruction of composite mandibular defects.

Adult↗
PubMed1996

Improvement of the radial forearm donor site by prefabrication of fascial-split-thickness skin grafts.

A basic disadvantage of radial forearm flaps is the removal of skin from a functionally important and cosmetically exposed region. To minimize the donor-site morbidity of the radial forearm flap, we have thus far used a two-phase procedure for intraoral defect coverage in five patients: In a first step, a split-thickness skin graft is transplanted to the forearm fascia, which "takes" there over a period of 2 weeks. In step two, the prefabricated fascial-split-thickness skin flap can be raised with complete preservation of the forearm skin and microsurgically transplanted like a conventional radial flap. Performing this procedure, we have obtained the following results: (1) All skin grafts "took" completely on the forearm fascia. (2) Prefabricated fascial-split-thickness skin flaps could be raised without any problems, like conventional radial forearm flaps. (3) All flaps were excellently suited for defect coverage in the oral cavity as very thin and moldable grafts and "took" without any complications. (4) Tension-free primary closure of all forearm donor sites was achieved with only slight cosmetic and functional impairment.

Fasciotomy↗
PubMed1995

Intraoral defect coverage with muscle flaps.

PURPOSE: This study investigated whether wound healing after the use of purely muscular flaps for intraoral defect coverage is negatively influenced by insipient muscular atrophy and the absence of a covering layer. MATERIALS AND METHODS: In an experimental study, microsurgical transplantation of muscle flaps from the anterior abdominal wall was carried out in 18 Lewis rats. A nerve anastomosis for motor reinnervation was not performed. Atrophy of the muscle flaps was determined by measuring the reduction of their size and weight after 3, 8, and 20 weeks. In the clinical part of the study, free muscle transplants from different donor regions (vastus lateralis, pectoralis major, internal oblique, and temporalis muscles) were used for defect coverage in various areas of the oral cavity. To study epithelization, punch biopsy specimens from the muscle surface were taken at periods of 2 to 4 weeks up to 6 months for histologic evaluation. Final evaluation of reconstruction results with special regard to speech, tongue mobility, mouth opening, chewing, and swallowing took place after 6 months. RESULTS: In the experimental study, average weight loss of the muscle flaps was 67% after 20 weeks, and the remaining surface area was 71%. The number of myocytes was only about 30% compared with control muscles, and parts of the flap appeared as a thin fibrous membrane. Clinically, this atrophy led to restricted mobility in such areas as the floor of the mouth, the buccal plane, and the tongue. Muscle flaps covering solid structures such as bones or reconstruction plates adapted well to the transplant bed, and the atrophy of the muscle led to no constriction of the surrounding tissue. Atrophy also did not have a negative effect when muscle flaps were placed in the region of the pharyngeal wall. Epithelization started from the edges after 2 weeks and was concluded after 8 weeks in all transplants if no additional radiation was performed. The muscle tissue was sufficiently resistant so that infection, fistulization, and necrosis did not occur. CONCLUSIONS: Muscle flaps undergo considerable atrophy with a cicatricial transformation and reduction of flexibility. Despite these disadvantages they can be used in the hard palate, the alveolar crest, and in the pharyngeal wall without causing functional restriction. Because of constriction of the surrounding tissues, mobile areas such as the buccal plane, the floor of the mouth, and the tongue are not suitable as sites for muscle transplants.

Abdominal Muscles↗
PubMed1994

[Significance of vascularization of jejunal transplants in secondary reconstruction of the mandible].

There is a difference in the vascular architecture of myocutaneous flaps and jejunal free flaps both available to replace resected mucosal tissue of the oral cavity after surgical treatment of oral cancer. The question in whether the mobilization of jejunal free flaps is possible without respect to the anastomized vessels in particular in secondary reconstruction procedures to achieve a bony continuity of the mandible. From 1985-1992 22 patients were operated on using microsurgically anastomized jejunal free flaps. In 7 cases a secondary mandibular reconstruction by means of microsurgically anastomized iliac crest grafts was performed. In respect of our results we recommend in cases of secondary mandibular reconstruction with mobilisation of the jejunal flap. 1. preoperative digital subtraction angiography, 2. temporary clamp of anastomized vessels with observation of the perfusion of the jejunal flap, 3. intraoperative doppler-sonography. These techniques allow a save evaluation of the vessels of the donor site prior to microvascular anastomoses for secondary bony reconstruction of the mandible.

Anastomosis, Surgical↗