Einzelreferate und Buchbesprechungen

Ohne Zusammenfassung     

Einzelreferate und Buchbesprechungen

Ohne Zusammenfassung     

Einzelreferate und Buchbesprechungen

Ohne Zusammenfassung     

Einzelreferate und Buchbesprechungen

Journal of Molecular Medicine -     

Über Genetische Vorgänge Bei Bakterien

Ohne Zusammenfassung     

Pre- and postsynaptic alpha-adrenoceptor antagonists: differentiated cardiovascular effects in the rat

Intravenous (i.v.) injections of yohimbine, phentolamine, prazosine and phenoxybenzamine lowered blood pressure and increased heart rate in conscious rats. Intracerebroventricular (i.c.v.) injections of yohimbine and phentolamine increased blood pressure and heart rate; this was antogonized by pretreatment with clonidine. Phenoxybenzamine and prozosine had no effect or gave hypotension and tachycardia on i.c.v. injection. Pentobarbitone anaesthesia partly antagonized the cardiovascular effects of all alpha-adrenoceptor antagonist. Synthesis and utilization of central noradrenaline was increased by i.v. or i.c.v. yohimbine; anaesthesia partly antagonized this effect. In peripheral tissues others have found that yohimbine, tolazoline, piperoxan and phentolamine are potent blockers of the presynaptic alpha-adrenoceptors while phenoxybenzamine and prazosine act preferentially on postsynaptic alpha-adrenoceptors. The differentiated cardiovascular response to i.c.v. injection of these blockers may reflect their different affinity to central pre- and postsynaptic alpha-adrenoceptors.     

Buchbesprechungen

Ohne Zusammenfassung     

German Association of Endocrine Surgeons practice guideline for the surgical management of malignant thyroid tumors

Introduction

Over the past years, the incidence of thyroid cancer has surged not only in Germany but also in other countries of the Western hemisphere. This surge was first and foremost due to an increase of prognostically favorable (“low risk”) papillary thyroid microcarcinomas, for which limited surgical procedures are often sufficient without loss of oncological benefit. These developments called for an update of the previous practice guideline to detail the surgical treatment options that are available for the various disease entities and tumor stages.

Methods

The present German Association of Endocrine Surgeons practice guideline was developed on the basis of clinical evidence considering current national and international treatment recommendations through a formal expert consensus process in collaboration with the German Societies of General and Visceral Surgery, Endocrinology, Nuclear Medicine, Pathology, Radiooncology, Oncological Hematology, and a German thyroid cancer patient support organization.

Results

The practice guideline for the surgical management of malignant thyroid tumors includes recommendations regarding preoperative workup; classification of locoregional nodes and terminology of surgical procedures; frequency, clinical, and histopathological features of occult and clinically apparent papillary, follicular, poorly differentiated, undifferentiated, and sporadic and hereditary medullary thyroid cancers, thyroid lymphoma and thyroid metastases from primaries outside the thyroid gland; extent of thyroidectomy; extent of lymph node dissection; aerodigestive tract resection; postoperative follow-up and surgery for recurrence and distant metastases.

Conclusion

These evidence-based recommendations for surgical therapy reflect various “treatment corridors” that are best discussed within multidisciplinary teams and the patient considering tumor type, stage, progression, and inherent surgical risk.     

Importance of Early Screening and Prophylactic Thyroidectomy in Asymptomatic Nonindex RET Germline Carriers

Genetic testing for RET germline mutations affords rapid identification of germline carriers, offering the prospect of cure before C-cell hyperplasia (CCH) has progressed to medullary thyroid carcinoma (MTC). Although nonindex RET mutation carriers have a better prognosis than do the index patients, it remains to be ascertained whether age represents a risk factor for MTC when screening patients. The current institutional study (October 1994 through June 1999) was set up to compare asymptomatic nonindex patients who were grouped by age: < 20 years and ≥ 20 years. Inclusion criteria were confirmed RET mutations in the germline, with no MTC being more advanced than pT1pN1M0. Adult patients (≥ 20 years) had MTC significantly more often (84% vs. 43%), significantly larger tumors (5 mm vs. 3 mm), and significantly higher basal calcitonin levels preoperatively (78.0 vs. 9.7 pg/ml) than their pediatric/adolescent counterparts (< 20 years). There was a close correlation between pT1 MTC and an elevated basal serum calcitonin level (r= 0.67; Spearman's rho). All three patients with lymph node metastases from MTC had elevated basal calcitonin levels. The two groups did not differ in terms of multifocality of MTC (pT1b), lymph node involvement (pN1) or bilateral lymph node metastasis (pN1b), or preoperative stimulated and postoperative basal and stimulated serum calcitonin. Prophylactic thyroidectomy should not be postponed beyond the age of 20, and it should be performed before basal serum calcitonin has turned positive. Pathologic conversion of stimulated serum calcitonin obviously marks the time in carriers of RET germline mutations when surgery should be scheduled at the latest to be prophylactic.