Normal values of plasma methoxyamines in the setting of renal insufficiency and peri-operative stress. Consequences for the etiological diagnosis of hypertension

INTRODUCTION: HPLC plasma methoxyamines measurements are the updated technique for the diagnosis of adrenergic hypersecretion. Their reliability meets that of urinary measurements. Significance of increased values is not yet fully established for the etiological diagnosis of hypertension in some situations, especially in case of renal insufficiency and in the peri-operative period. The aim of this study is to define the "normal" range of the values of plasma methoxyamines in both of those conditions. PATIENTS AND METHODS: in a General and Endocrine Surgical Unit, 3 homogeneous group of 20 patients each have been studied: group 1, control (patients awaiting thyroidectomy); group 2, patients on maintenance hemodialysis submitted for hyperparathyroidism; group 3, patients submitted to digestive surgery. Measurements were done pre-operatively in group 1, pre and post-operatively in group 2, and post-operatively in group 3. RESULTS: in comparison to the control (11.8 nmol/l), we observed in group 2 a 18 fold increase preoperatively, and a 29 fold increase at post-operative day 1. In group 3, we observed a 2.3, 2.7 and 2 fold increase at post-operative days 1,2 and 3 respectively. All those results were statistically significant. CONCLUSION: Results of measurements of plama methoxyamines should always be matched to the serum creatinine levels. They are meaningful for the diagnosis of endocrine origin of hypertension only late after the early post-operative period

Hereditary Neuropathy with Liability to Pressure Palsies: A Clinical And Molecular Study in a South African Family of Indian Descent

Background Hereditary neuropathy with liability to pressure palsy (HNPP) first described in 1947, has been showed to be due to a 1.5Mb deletion, which includes the peripheral myelin protein 22 (PMP22) gene, on chromosome 17p11.2. HNPP is more common than previously thought. Objective We describe the clinical and molecular features in a three generation family where the index case became acutely disabled following surgery for cervical spondylosis. Method A total of 14 (including the index case) were examined. Eleven had clinical evidence of disease. The disability of this group ranged from asymptomatic (1), mild (4), moderate (4), severe (1) to death (1). The findings on examination ranged from a single nerve involvement to a confluent mononeuropathy multiplex. The patient who died had marked proximal and distal weakness. The immediate cause of death is unknown. On history two individuals (now deceased) were said to be affected. A further 2 subjects who were not available for examination but who provided blood for molecular analysis were said to be normal. A PCR based strategy for the determination of the PMP22 gene dose was undertaken in 15 subjects. Results Four of these individuals (2 on history and 2 on examination) who were clinically normal had no deletions. All the clinically affected individuals all exhibited the appropriate deletion. One was clinically normal but carried the deletion. Sample from a 16th individual, who was not examined, was insufficient. Conclusion This study is the first report of the existence of HNPP in South Africa. Cases are probably being missed. The correct diagnosis is important, as with appropriate measures and patient education, disability can be significantly reduced. Résumé Introduction Décrite en 1947, la neuropathie héréditaire avec hypersensibilité à la pression (NHHP) est une neuropathie héréditaire sensitivomotrice à transmission autosomique dominante. Cette affection est liée à un défaut de synthèse d\'une protéine de la myéline : la protéine PMP22 (peripheral myelin protein 22) en rapport dans près de 90% des cas à une délétion de 1,5 mégabases dans la région 17p11.2 incluant le gène PMP22. L\'HNPP paraît plus fréquent qu\'on ne le pensait. Objectif Nous décrivons les aspects cliniques et moléculaires d\'une famille sud africaine d\'origine indienne, sur trois générations, découverte lors d\'une décompensation aiguë suite à une intervention pour une myélopathie cervicarthrosique. Matériel et méthodes 14 cas ont été étudiés. 11 patients avaient des signes cliniques évidents. Le groupe a été classé selon les aspects suivants : asymptomatique, discret, modéré, sévère et décès. Les constatations étaient en rapport avec une atteinte tronculaire nerveuse, unique ou multiple. . Une enquête familiale a permis de réaliser des examens cliniques et biologiques . Résultats Le PCR a été pratiqué chez 15 patients. Quatre des patients asymptomatiques n\'avaient pas de délétion. Tous les patients symptomatiques avaient une délétion. Un patient asymptomatique était porteur d\'une délétion.. Le patient décédé de cause inconnue présentait une faiblesse proximale et distale très marquée Conclusion Il s\'agit du premier cas rapporté en République Sud-Africaine sans que cela ne préjuge du nombre de cas qui est vraisemblablement sous-estimé. Le diagnostic de HPPN ne doit pas être omis compte tenu des éventuelles conséquences fonctionnelles. (Af. J. of Neurological Sciences: 2003 22(1)