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K Wangerin

Publications and source records attributed to K Wangerin.

At least 19 recordsLinked to original sources
PubMed2005

A comparison of the COG and MCNP codes in computational neutron capture therapy modeling, Part I: boron neutron capture therapy models.

The goal of this study was to evaluate the COG Monte Carlo radiation transport code, developed and tested by Lawrence Livermore National Laboratory, for neutron capture therapy related modeling. A boron neutron capture therapy model was analyzed comparing COG calculational results to results from the widely used MCNP4B (Monte Carlo N-Particle) transport code. The approach for computing neutron fluence rate and each dose component relevant in boron neutron capture therapy is described, and calculated values are shown in detail. The differences between the COG and MCNP predictions are qualified and quantified. The differences are generally small and suggest that the COG code can be applied for BNCT research related problems.

Body Burden↗
PubMed2005

A comparison of the COG and MCNP codes in computational neutron capture therapy modeling, Part II: gadolinium neutron capture therapy models and therapeutic effects.

The goal of this study was to evaluate the COG Monte Carlo radiation transport code, developed and tested by Lawrence Livermore National Laboratory, for gadolinium neutron capture therapy (GdNCT) related modeling. The validity of COG NCT model has been established for this model, and here the calculation was extended to analyze the effect of various gadolinium concentrations on dose distribution and cell-kill effect of the GdNCT modality and to determine the optimum therapeutic conditions for treating brain cancers. The computational results were compared with the widely used MCNP code. The differences between the COG and MCNP predictions were generally small and suggest that the COG code can be applied to similar research problems in NCT. Results for this study also showed that a concentration of 100 ppm gadolinium in the tumor was most beneficial when using an epithermal neutron beam.

Body Burden↗
PubMed2000

[Distraction in mouth, jaw and facial surgery].

Distraction osteogenesis is established worldwide as a new surgical technique. The former rule, not to osteotomize before the end of bone growth, is no longer valid. Today, distraction starts as early as infancy as well as in childhood and adolescence. This new method allows the gain of bone in the distraction gap so that bone grafting can be avoided. Distraction is indicated in hemifacial microsomias, multiple syndromes with mandibular malformations, mandibular retrognathia, posttraumatic jaw deficiencies, craniofacial malformations, alveolar ridge resorptions, and alveolar ridge resections. Distraction surgery started in the mandible and was continued in the maxilla and the craniofacial region. Alveolar ridge distraction followed. After using extraoral devices, the development of internal applicable distractors followed. Today, bi- or tridirectional internal devices are already available. The whole treatment concept includes the orthodontist. Distraction planning before surgery is of great importance. The literature presently includes methods, indications, and case reports but only few results, which we compare with our experiences.

Adolescent↗
PubMed2000

Vertical distraction of a free vascularized fibula flap in a reconstructed hemimandible: case report.

The authors report a case of vertical distraction osteogenesis of a free revascularized fibula flap used to reconstruct an hemimandible lost as a result of a gunshot injury. The reconstruction procedure and the distraction protocol are described; clinical and radiological results are presented. The vertical discrepancy between the fibula and the native right hemimandible was corrected.

Adult↗
PubMed1997

[Improving the contour and preserving the profile of the lower third of the face].

Aesthetic surgery of the lower third of the face is divided up into five clinically relevant problem regions: nasolabial folds, lips, chin, mandibular angle including horizontal ramus and neck. Surgical correction is be described in the international literature. The pathophysiological conditions that lead to aesthetic problems in the lower third of the face are explained. Based on this, the indications for different methods of correction, which include soft and bony tissue of the face, are explained. The results of our own clinical experience, dependent on alloplastic material, are presented with all the advantages and disadvantages.

Cephalometry↗
PubMed1995

Human bone cell phenotypes differ depending on their skeletal site of origin.

This report describes skeletal site-related differences in human osteoblastic cell metabolism in studies of four patients. Northern analyses of the constitutive growth factor messenger ribonucleic acid (mRNA) expression pattern in mandibular and iliac crest-derived human osteoblastic cells (based on within-patient comparisons) revealed higher mRNA levels for strong mitogenic growth factors such as basic fibroblast growth factor (bFGF) and insulin-like growth factor II (IGF-II) in the rapidly proliferating and less alkaline phosphatase (ALP)-expressing mandibular osteoblastic cells compared to those in the lower bFGF and IGF-II mRNA levels in slowly proliferating iliac human osteoblastic cells exhibiting a higher ALP expression level. In contrast, transforming growth factor-beta (TGF beta) mRNA was more abundant in iliac human osteoblastic cells than in mandibular osteoblastic cells. Furthermore, we found that there was a proportionality, based on data from both sites, between the level of constitutive TGF beta mRNA and the response to exogenously administered bFGF or IGF-II. A comparable pattern of growth characteristics and mRNA expression was also observed in transformed human osteoblastic cells that had been subcloned in sublines expressing high and low levels of the human osteoblastic differentiation marker ALP. These findings are consistent with 1) skeletal site-related differences in human bone cell phenotypes, and 2) decreased IGF-II and bFGF expression and increased TGF beta expression and responsiveness to bFGF and IGF-II in human bone cells exhibiting a high ALP expression.

Alkaline Phosphatase↗
PubMed1990

[Does the use of miniplates for fracture treatment influence mandibular growth? An experimental animal study].

The mandibles of 2-month-old rats were artificially fractured and then stabilised with miniplates. The experiments lasted until growth was concluded in the animals. We found an inhibition of mandibular growth due to both the trauma and the operation. The growth retardation due to fracture was increased by the operation. The growth inhibition was directly proportional to the severity of trauma and operation.

Animals↗
PubMed1989

[Effects of different sterilizing techniques on osseous regeneration of grafted lyophilized cartilage].

The suitability of variably sterilized lyocartilage grafts as potential bone substitutes was investigated in animal experiments with special attention to configurational stability. In 3 Beagles corticocancellous implant beds were prepared by box-type ostectomies and lyophilized costal cartilage blocks sterilized with X-rays,ethylene oxide gas and beta-propriolactone solution were placed into them. Implants sterilized with X-rays and beta-propriolactone appeared to be unsuited for recontouring facial bone defects, since they showed complete loss of configuration after a follow-up time of 125 and 230 days, respectively. By contrast, cartilage implants sterilized with ethylene oxide gas retained their configuration after no less than 328 days. In light of these results, methods for sterilizing other biomaterials should be re-considered.

Animals↗
PubMed1987

Behavior of differently sterilized allogenic lyophilized cartilage implants in dogs.

The behavior of beta-propriolactone-sterilized, radiation-sterilized, and gas-sterilized lyophilized cartilage implants was histiologically investigated at various intervals up to 328 days. Beta-propriolactone-sterilized lyophilized cartilage implants were completely resorbed after 230 days and had only undergone partial osseous substitution. The radiation-sterilized lyophilized cartilage implants behaved similarly after 125 days. Despite partial resorption of the gas-sterilized lyophilized cartilage after 328 days, constant form was maintained and complete bony substitution of the resorbed regions had occurred in each case.

Animals↗
PubMed1986

The autoclaved autogenous bone graft as a re-implant. Results of animal experiments.

The use of autoclaved bone grafts was studied in animal experiments. First we checked the immunological response in inbred rats. No antigen-antibody reaction could be detected after syngenic and allogenic autoclaved bone grafting. The bone healing of autogenous autoclaved rib grafts of different length was tested in inbred dogs. After polychrome sequential marking we investigated the periosteal and endosteal osteogenic repair of the transplant-area using different histological techniques. Simultaneously we observed the slow destruction and lysis of the autoclaved graft. In our opinion the use of autoclaved autogenous bone graft is possible, under stable conditions, for immediate reconstruction of the mandible in tumour surgery.

Animals↗
PubMed1986

The autoclaved autogenous reimplant, an immediately replaced, mineral frame.

Due to our good experimental results with an immediate mandibular body-replacement after resections we report our clinical and histological findings of a 35 weeks-lasting transplantation of autoclaved bone. We could not confirm a "foreign body" reaction and absent bone-resorption by osteoclasts, described by Harding in 1957. During metal removal after the 28th week postoperatively we observed clinically a good incorporation of the graft and the histological evaluation of the 28th and 35th week specimens showed an excellent bony bridging of the osteotomy, non-irritant incorporation of the graft and a beginning remodelling of the mineral frame which had functioned as an immediate space retainer.

Bone Plates↗
PubMed1986

[The syndrome of enlarged orbits].

Combined orbital fractures cause hematomas and subsequent rigidity of the ligament apparatus around the inferior rectus muscles, while the few true blow-out fractures may lead to an adherence of connective tissues to the floor. The authors describe a third mechanism: Enlargement of the orbit impairs motility, especially the elevation of the globe: Diagnostic pressing of the orbital, parabulbar contents improves elevation. In 9 such cases that were free of the two other knows mechanisms motility was improved by reducing orbital volume. This was performed by implants (4 cases), by instillation of hydroxylapatite (4 cases) or by re-resection of the bony frame (1). Subsequent muscle surgery, if at all necessary, gave truly satisfactory results.

Collagen↗