Petra B. Musholt

Familial papillary thyroid carcinoma: genetics, criteria for diagnosis, clinical features, and surgical treatment.

Hereditable predisposition to papillary thyroid carcinoma (PTC) and multinodular goiter (MNG) without evidence of an association with other malignancies as a distinct entity was recognized only recently. A meta-review of the literature on familial PTC (FPTC) was undertaken, and characteristics of families with frequent occurrence of PTC or MNG (or both) were summarized. A database on thyroid cancer patients maintained in our institution was searched for potential FPTC families. Clinical examinations were performed in 6 of 12 Hannover kindreds identified, and blood samples of all family members were collected for genetic analyses. Clinical presentations and histopathologic features of the FPTC cases were compiled. Based on the FPTC meta-review and own experience, predictive criteria to identify families at risk were developed: Exclusion criteria were previous radiation exposure and coincidence with neoplasia syndromes. Primary criteria for susceptibility to FPTC are (1) PTC in two or more first-degree relatives and (2) MNG in at least three first- or second-degree relatives of a PTC patient. Secondary criteria are diagnosis in a patient younger than 33 years, multifocal or bilateral PTC, organ-exceeding tumor growth (T4), metastasis (N1, M1), and familial accumulation of adolescent-onset thyroid disease. A hereditary predisposition to PTC is considered if both primary criteria or one primary criterion plus three secondary criteria are present. Family history-taking is recommended for all PTC patients to identify FPTC kindreds at risk. Blood relatives of FPTC index patients who harbor MNG should undergo thorough and regular clinical screening. Suspicious lesions should prompt early surgical intervention.

Transplantation of adrenal tissue fragments in a murine model: functional capacities of syngeneic and allogeneic grafts.

Oral hormone substitution for the treatment of Addison’s disease inadequately replaces the physiologic circadian secretion of corticosteroids. Alternative therapeutic approaches are reimplantation of healthy autologous adrenal tissue and allogeneic transplantation (Tx), respectively. The aim of our study was to evaluate the functional capacity of adrenal grafts and the influence of intercellular adhesion molecule-1 (ICAM-1) on graft survival. Fragmented adrenal glands of wild-type B10.BR (H-2k) and wild-type or ICAM-1-deficient BALB/c (H-2d) mice were transplanted underneath the kidney capsule of adrenalectomized B10.BR mice [complete major histocompatibility complex (MHC) haplotype disparity in the latter]. Postoperatively, the endocrine function of the adrenal grafts was evaluated by the following parameters: (1) survival analysis of the recipients (termination at day 70 after Tx); (2) reverse transcription-polymerase chain reaction expression analysis of aldosterone synthase (zona glomerulosa-specific) and of 11b-hydroxylase (zona fasciculata-specific); and (3) measurement of basal adrenocorticotropic hormone (ACTH) stimulated serum corticosterone levels. Expression of both enzyme-specific mRNAs was detected in the grafts at any time during the post-Tx period. The adrenal grafts of syngeneic and surviving MHC-disparate mice displayed a similar basal hormone secretion, which was about 60% lower than that in sham-operated animals. In the transplanted mice, ACTH-stimulated corticosterone measurement revealed a 5- to 10-fold decreased functional reserve capacity. ICAM-1 deficiency significantly prolonged the survival of adrenal grafts. Fragmented adrenal grafts are able to maintain physiologic basal corticosterone levels but had markedly reduced reserve capacity. Nevertheless, the results give rise to hopes that autologous or MHC-compatible allogeneic transplantation of adrenal grafts may replace oral hormone substitution in humans.

Detection of H-2 alleles by PCR-RFLP—an alternative to flow cytometry in the screening of transgenic mice

An increasing number of experimental models is based on well-defined transgenic mice in medical and biological research. Particularly in settings in which transgenic recombinants are used, a fast and reliable method is needed to screen for a defined H-2 background. For this purpose, flow cytometry with specific monoclonal antibodies is the standard procedure. However, epitopes of closely related rodent strains show only minor variations affecting the production of specific discriminating antibodies. Therefore, cross-reactivity of antibodies against specific major histocompatibility complex (MHC) leads to unreliable results in settings with closely related strains. In need of a method with high reliability, we have designed a screening assay based on polymerase chain reaction (PCR) followed by restriction fragment length polymorphisms (RFLP) to discriminate the MHC class I antigens H-2K(d), -K(b), -K(k), which are sequence variants of the H-2K gene. A part of the mus musculus MHC gene coding for H-2K-covering exons 4 and 5 with MHC-differentiating restriction sites-was amplified. Subsequent restriction digest of the PCR products allows to discriminate the three aforementioned alleles and to identify homozygous as well as heterozygous haplotypes. To distinguish transgenic mice defined by certain MHC backgrounds, the PCR-RFLP method is simple, cost-effective, specific, and reliable and can be used independently or in addition to other methods in any laboratory.

Allogeneic adrenocortical transplantation: glucocorticosteroid-independent immunomodulatory properties of adrenal cortex cells.

Background. Hormone substitution for the treatment of adrenocortical insufficiency does not adequately substitute the physiologic circadian secretion of corticosteroids and leads to long-term sequelae and reduced quality of life. The lack of adaptation to physical and psychologic stress situations may lead to life-threatening Addison’s crises. Allogeneic transplantation of adrenal cortex could offer an intriguing alternative. Adrenocortical grafts were demonstrated to proliferate and produce corticosteroids in physiologic concentrations after transplantation. Methods. Kb-transgenic murine lymphocytes and allogeneic adrenal cortex cells were cocultured in mixed lymphocyte reactions to examine the alloimmune response; lymphocytes from T-cell receptor transgenic mice and normal mice, respectively, served as responder cells. The effects of corticosteroids secreted by adrenocortical cells were antagonized by the steroid receptor antagonist mifepristone, whereas the impact of cell-cell interactions was differentiated with transwell culture systems. Results. Coculture of adrenal cortex cells in mixed lymphocyte reactions markedly suppressed lymphocyte proliferation. Transwell cultures demonstrated that adrenocortical cells exerted their effects by a soluble factor that was only partially antagonized by mifepristone. Conclusion. In vitro, the presence of adrenocortical cells potently suppressed allogeneic immune responses. This effect was not exclusively the result of the secretion of corticosteroids, indicating an additional immunomodulatory property of adrenocortical cells.