Effects of autotransplanted lymph node fragments on the lymphatic system in the pig model.

Secondary lymphedema often develops after removal of lymph nodes in combination with radiation therapy, in particular in patients with breast cancer, inguinal cancer, cervical cancer and melanoma. No convincing treatment for the prevention and therapy of acquired lymphedema exists so far, therefore we wanted to show the reintegration of transplanted avascular lymph node fragments in the lymphatic system and positive effects of the transplanted fragments on the restoration of the lymphatic flow in this study. A total of 26 minipigs underwent lymphadenectomy of both groins. A minimum of one lymph node was retransplanted. The lymph nodes were cut into small pieces and retransplanted in the left groin (n = 17) or in both groins (n = 9). Different retransplantation techniques were investigated, transplantation of large versus small fragments, with and without capsule. The lymph flow was evaluated 5 and 8 months after surgery, using SPECT/CT and Berlin Blue. The results were confirmed by dissection. The lymph node transplants were assessed histologically. In contrast to the lymph flow in the transplanted groin, the lymph flow in the non-transplanted groin was often malfunctioning. Large lymph node fragments were found reintegrated in the lymphatic system more often than small slices of lymph node fragments. About 5 months after surgery impairment of lymph flow was seen especially after retransplantation of small slices of lymph node fragments. In seven out of eight minipigs a dermal backflow developed in the non-transplanted groin, 8 months after surgery. Only one minipig of these groups developed dermal backflow in both groins. All lymph node fragments showed an organized structure histologically. Autologous lymph node transplantation has positive effects on the regeneration of lymph vessels and restoration of lymph flow after lymphadenectomy.

Evidence for gene recombination in FCGR3 gene variants.

BACKGROUND AND OBJECTIVES: The genes encoding the Fcgamma receptors (FcgammaR) IIIa and IIIb (FCGR3A and FCGR3B) are clustered on chromosome 1 band q23-24 and exhibit allelic polymorphism. We investigated the molecular basis of additional new FCGR3 genomic variation. MATERIALS AND METHODS: A segment shared by FCGR3A and FCGR3B containing the polymorphic nucleotide positions 141, 147, 227, 266, and 277 in exon 3 was cloned and sequenced from genomic DNA of 30 donors and 3 bacterial artificial chromosome (BAC) clones. A mixture consisting of isolated FCGR3B*2- and FCGR3A- plasmids was cloned and sequenced as well. Additionally, nucleotide databases were screened for clones with variant FCGR3 sequences. RESULTS: A total of 12 FCGR3 variants defined by the polymorphic positions were detected in whole blood genomic DNA from 23 of 24 FCGR3B*2 and/or FCGR3B*3 positive donors, the DNA from two of three BAC clones and in the DNA mixture of isolated FCGR3B*2- and FCGR3A- plasmids. CONCLUSION: Nucleotide exchanges of the variants were non-random and resulted from two alternative nucleotides present in one of the polymorphic position of the basic FCGR3 forms. Polymerase chain reaction (PCR) artefacts cannot be excluded as origin of new variants, but there is strong evidence that at least two variants are the result of a somatic recombination.

SPECT-CT: a valuable method to document the regeneration of lymphatics and autotransplanted lymph node fragments.

PURPOSE: The transplantation of lymph node fragments and stimulation of lymph vessel regeneration seems to be a promising model to prevent lymphoedema in patients after mammary tumour excision combined with axillary lymph node dissection and irradiation. This study evaluated the advantages of SPECT-CT in studying the regeneration of lymph vessels and lymphoid tissue after autologous lymph node transplantation. METHODS: Five minipigs underwent autologous lymph node transplantation in the left groin. The lymph node was excised, cut into six pieces and embedded into two newly created subcutaneous pouches on this side. The superficial lymph node of the right groin was removed as a control. Five months after surgery the lymph flow of both legs was investigated using conventional lymphoscintigraphy and SPECT-CT with 10 MBq(99m)Tc-nanocolloid in combination with Berlin Blue injected subcutaneously into the draining area. RESULTS: The integration of the transplanted lymph node fragments was shown. The SPECT-CT results correlated with the in situ findings observed at dissection. Afferent and efferent lymph flow could be followed up to the lumbar trunks. The use of SPECT-CT allowed exact localisation of the lymph node fragments in three-dimensional space and the regeneration of the lymph node fragments was documented histologically. CONCLUSION: SPECT-CT is a good method to evaluate lymphatic flow and document lymph node regeneration. The data suggest that autologous lymph node transplantation is a promising model for prevention of lymphoedema.

Methyl methacrylate cranioplasty in children: long-term results.

The long-term outcome of 75 children who underwent methyl methacrylate cranioplasty over a 15-year period is presented. Forty-two patients underwent cranioplasty for posttraumatic skull defects and 33 for nontraumatic causes. Within 8 years following initial cranioplasty procedure, a total of 17 (23%) complications occurred. Several factors correlated with the development of complications, including postoperative radiotherapy, the size of the defect, involvement of the frontal sinus, and the presence of prior infection. The authors currently recommend avoiding methyl methacrylate cranioplasty in selected patients who have received postoperative radiation therapy, in patients with large cranial defects, involvement of the frontal sinus, or any history of prior infection.