Germline mutation in BRAF codon 600 is compatible with human development: de novo p.V600G mutation identified in a patient with CFC syndrome

Champion KJ, Bunag C, Estep AL, Jones JR, Bolt CH, Rogers RC, Rauen KA, Everman DB. Germline mutation in BRAF codon 600 is compatible with human development: de novo p.V600G mutation identified in a patient with CFC syndrome. BRAF, the protein product of BRAF, is a serine/threonine protein kinase and one of the direct downstream effectors of Ras. Somatic mutations in BRAF occur in numerous human cancers, whereas germline BRAF mutations cause cardio‐facio‐cutaneous (CFC) syndrome. One recurrent somatic mutation, p.V600E, is frequently found in several tumor types, such as melanoma, papillary thyroid carcinoma, colon cancer, and ovarian cancer. However, a germline mutation affecting codon 600 has never been described. Here, we present a patient with CFC syndrome and a de novo germline mutation involving codon 600 of BRAF, thus providing the first evidence that a pathogenic germline mutation involving this critical codon is not only compatible with development but can also cause the CFC phenotype. In vitro functional analysis shows that this mutation, which replaces a valine with a glycine at codon 600 (p.V600G), leads to increased ERK and ELK phosphorylation compared to wild‐type BRAF but is less strongly activating than the cancer‐associated p.V600E mutation.     

Secondary and tertiary structure modeling reveals effects of novel mutations in polycystic liver disease genes PRKCSH and SEC63

Waanders E, Venselaar H, te Morsche RHM, de Koning DB, Kamath PS, Torres VE, Somlo S, Drenth JPH. Secondary and tertiary structure modeling reveals effects of novel mutations in polycystic liver disease genes PRKCSH and SEC63. Polycystic liver disease (PCLD) is characterized by intralobular bile duct cysts in the liver. It is caused by mutations in PRKCSH, encoding hepatocystin, and SEC63, encoding Sec63p. The main goals of this study were to screen for novel mutations and to analyze mutations for effects on protein structure and function. We screened 464 subjects including 76 probands by direct sequencing or conformation‐sensitive capillary electrophoresis. We analyzed the effects of all known and novel mutations using a combination of splice site recognition, evolutionary conservation, secondary and tertiary structure predictions, Poly Phen , and p Mut and sift . We identified a total of 26 novel mutations in PRKCSH (n = 14) and SEC63 (n = 12), including four splice site mutations, eight insertions/ deletions, six non‐sense mutations, and eight missense mutations. Out of 48 PCLD mutations, 13 were predicted to affect splicing. Most mutations were located in highly conserved regions and homology modeling for two domains of Sec63p showed severe effects of the residue substitutions. In conclusion, we identified 26 novel mutations associated with PCLD and we provide in silico analysis in order to delineate the role of these mutations.     

Microsurgical anatomy of VII and VIII cranial nerves and related arteries in the cerebellopontine angle

Summary The relationships of VII and VIII cranial nerves and related arteries are reviewed in 26 preparations by microdissection techniques. These vessels may be grouped in large (AICA, PICA), medium (LA, SA, CSA, RPI) and small calibre (vasa nervorum, radicullar and medullar branches). The importance of these structures in acoustic neuroma surgery, vestibular neurectomy and cross-compression syndromes is discussed. Vascular loops and elongated arteries are normal structures present at birth.This work was supported by a grant from the AJ Roemmers Foundation     

Chondromalacia patellae: assessment with MR imaging

Magnetic resonance (MR) images of the posterior patellar hyaline articular cartilage were obtained in 23 subjects to determine if MR imaging could accurately demonstrate the patellar cartilage. Arthroscopy was used as the standard of reference. Three subjects were asymptomatic volunteers. In the remaining 20 who had patellofemoral pain, arthroscopy was performed before MR imaging in seven and afterward in 12; one did not undergo arthroscopy. MR imaging showed focal areas of swelling of the patellar cartilage, focal hypointensity, surface irregularity, areas of thinning, and areas of cartilage loss with exposure of subchondral bone. The surgical findings agreed with those from MR images in all seven patients who underwent arthroscopy before MR imaging and in ten of the 12 who underwent surgery afterward. MR imaging is an accurate means of examining the posterior patellar cartilage and should be considered as an alternative to diagnostic arthroscopy when chondromalacia patellae is suspected.     

Does preoperative needle localization lead to an increase in local breast cancer recurrence?

Between 1978 and 1981, 74 women with nonpalpable breast cancer underwent surgery after localization guides were placed. In 72 patients, guides were introduced parallel to the chest wall; in two the needle was positioned anteroposteriorly under computed tomographic guidance. Fifty-six cases (76%) were infiltrating cancer; 13 (17%), intraductal cancers; two (3%), inflammatory; and three (4%), lobular carcinoma in situ. Surgery was not used to treat the latter five patients. In the remaining 69 women, 42 (61%) were treated by means of modified radical mastectomy; six (9%), total mastectomy; 12 (17%), local excision and radiation therapy; and seven (10%), local excision alone; exact therapy for two women (3%) was unknown. At a minimum follow-up of 5 years, none of the 67 women in whom the parallel approach was used had a local recurrence. The authors conclude that preoperative placement of guides parallel to the chest wall does not appear to increase the risk of local breast cancer recurrence.     

5-HYDROXYTRYPTAMINE-INDUCED CONTRACTION OF THE MARMOSET AORTA IS MEDIATED BY A 5-HT1-LIKE RECEPTOR

1. 5-Hydroxytryptamine (5-HT) exerts both contractile and relaxant effects in the marmoset isolated aorta, actions that are unaffected by the 5-HT₂ antagonist ketanserin. The aim of the present study was to define the receptors mediating the contractile activity of 5-HT in the marmoset aorta.
2. Contractile responses were elicited in aortic rings that were either: (i) precontracted submaximally with the thromboxane A₂ agonist U44069 in order to amplify the responses; or (ii) exposed to N ^ω-nitro- L -arginine (100 μmol/L) plus LY 53857 (0.1 μmol/L; a 5-HT₂ receptor antagonist shown previously to inhibit relaxation). The effect of 5-HT on adenosine 3',5'-cyclic monophosphate (cAMP) formation was also investigated.
3. The effects of agonists and antagonists comprised: (i) agonist potencies in the order 5-carboxamidotryptamine > 5-HT > sumatriptan > 8-hydroxy-2-(di- n -propylamino)tetralin; (ii) inhibition of contractile action of 5-HT by the 5-HT_1D antagonist GR 127935; (iii) a contractile response to methysergide; (iv) a lack of effect of tropisetron, an antagonist of 5-HT₃ and 5-HT₄ receptors; and (v) inhibition of forskolin-stimulated cAMP formation by 5-HT (in the presence of LY 53857), indicative of negative coupling to adenylate cyclase.
4. The above effects fulfil the criteria for a 5-HT₁-like receptor. In view of the previous finding that this contractile response is insensitive to ketanserin, it is concluded that the contractile effects of 5-HT in the marmoset aorta are mediated exclusively by a 5-HT₁-like receptor.     

The role of electrophysiology in the evaluation of incontinence and prolapse

PURPOSE OF REVIEW: Apart from histopathology, electrophysiological methods are the only tests to reveal neuromuscular involvement in the absence of gross anatomical lesions. They have played a major role in establishing the neuromuscular lesion due to vaginal delivery as a risk factor for incontinence and pelvic organ prolapse, but there is no consensus on the usefulness of different methods. It is timely to reevaluate their validity, and their role in urogynecology. RECENT FINDINGS: The most important development is the move towards standardization of the diagnostic approach, based on computer assisted quantified techniques of concentric needle electromyography. Studies using less operator biased techniques have confirmed subtle pelvic floor muscle changes in parous women. Reports on usefulness of different tests as predictors of treatment outcome are controversial. SUMMARY: Standardization of concentric needle electromyography strengthened the position of this test as practical and informative. Neuromuscular changes following vaginal delivery have been reconfirmed, but the usefulness of particular electrophysiological tests in the individual patient needs to be further researched. Valid clinical neurophysiological methods remain valuable as research tools for incontinence and prolapse pathophysiology.     

Thyrotrophin estimation in diagnosis and treatment of childhood thyroid disorders

Serum thyrotrophin (TSH) was estimated by double-antibody radioimmunoassay in 200 children aged 2 months to 16 years with normal thyroid function. There was no apparent variation in TSH with age or sex and only 4 children had TSH levels greater than 5 muU/ml. High TSH values were obtained in 9 children with primary hypothyroidism, in 3 children with thyroiditis, and in one girl with a lingual thyroid. Moderately raised TSH was found in 3 girls with thyroiditis, 2 brothers with goitres due to enzyme defect, and a girl with an ectopic thyroid. In one girl with a defect of iodine organification and in 3 boys with thyroxine binding globulin deficiency the TSH levels were normal despite very low serum thyroxine values. Serum TSH was also estimated in 20 children during treatment for primary hypothyroidism. 3 of these children showed slightly raised TSH levels despite apparently adequate replacement therapy with L-thyroxine. One girl showed a very high TSH level 3 weeks after treatment had been temporarily withdrawn.