Dermatological manifestations of inherited cancer syndromes in children.

Various cutaneous signs presenting in childhood, for example café-au-lait macules, may have systemic cancer associations. Indeed, this may be the first manifestation of the underlying cancer predisposition. The syndromes covered in this review fall into four main categories: (i) DNA damage processing defects including Fanconi anaemia, ataxia telangiectasia, Bloom syndrome, Rothmund-Thomson syndrome, constitutional mismatch repair defects and xeroderma pigmentosum; (ii) signalling pathway defects, including naevoid basal cell carcinoma and Costello syndromes; (iii) primary immunodeficiency syndromes; and (iv) syndromes that do not fit this molecular classification, such as X-linked dyskeratosis congenita. This review focuses on the dermatological findings of these conditions. Some of these conditions exhibit a milder heterozygous phenotype and this should be elicited in the family history. Where the dermatological findings are subtle, a targeted family history can provide clues towards making a diagnosis. Nondermatological features of each condition are summarized too, together with molecular testing strategies, which will direct genetic counselling and screening. This review will enable the dermatologist and other clinicians in the early recognition and molecular confirmation of underlying cancer-predisposing syndromes. This allows the possibility of surveillance and prevention strategies to be initiated in a timely manner, in affected children and other at-risk family members.

[Gross haematuria as the primary symptom of extramedullary IgM plasmacytoma of the bladder]. / Makrohämaturie als Primärsymptom eines extramedullären IgM-Plasmozytoms der Harnblase.

Haematuria is the most common clinical symptom of bladder cancer. Besides antibiotic treatment of a probably existing urinary tract infection, ultrasonography of the urinary organs, diagnostic cystoscopy (with biopsy if needed), and radiologic evaluation of the upper urinary tract (intravenous urography, computed tomography or magnetic resonance urography, retrograde pyelography) should be done for further evaluation. Atypical manifestations of systemic diseases with bladder infiltration could feign the clinical appearance of chronic cystitis and hinder determination of the correct diagnosis. The case of a 40-year-old man with recurrent gross haematuria due to extremely rare bladder infiltration through an IgM plasmacytoma is presented.

Electrostatic influence of local cysteine environments on disulfide exchange kinetics.

The ionic strength dependence of the bimolecular rate constant for reaction of the negative disulfide 5,5'-dithiobis (2-nitrobenzoic acid) with cysteines in fragments of naturally occurring proteins was determined by stopped-flow spectroscopy. The Debye-Hückel relationship was applied to determine the effective charge at the cysteine and thereby determine the extent to which nearby neighbors in the primary sequence influence the kinetics. Corrections for the secondary salt effect on cysteine pKs were determined by direct spectrometric pH titration of sulfhydryl groups or by observation of the ionic strength dependence of kinetics of cysteine reaction with the neutral disulfide 2,2'-dithiodipyridine. Quantitative expressions was verified by model studies with N-acetyl-cystein. At ionic strengths equal to or greater than 20 mM, the net charge at the polypeptide cysteine site is the sum of the single negative charge of the thiolate anion and the charges of the amino acids immediately preceding and following the cysteine in the primary sequence. At lower ionic strengths, more distant residues influence kinetics. At pH 7.0, 23 degree C, and an ionic strength of 20 mM, rate constants for reaction of the negative disulfide with a cysteine having two positive neighbors, one positive and one neutral neighbor, or two neutral neighbors are 132000, 3350, and 367 s-1 M-1, respectively. This corresponds to a contribution to the activation energy of 0.65- 1.1 kcal/mol per ion pair involved in collision between the cysteine and disulfide regions. The results permit the estimation that cysteine local environments may provide a means of achieving a 10(6)-fold range in rate constants in disulfide exchange reactions in random-coil proteins. This range may prove useful in developing strategies for directing disulfide pairing in synthetic proteins.