Facioscapulohumeral muscular dystrophy (FSHD) is associated with a decreased number of D4Z4 repeats on chromosome 4q35. Diagnostic difficulties arise from atypical clinical presentations and from an overlap in D4Z4 numbers between controls and FSHD individuals. Thus, a molecular genetic test result with a borderline D4Z4 number has its limitations for the clinician wanting to differentiate between the diagnosis of FSHD and a myopathy presenting with FSHD-like symptoms.To investigate this problem in more detail we conducted a systematic study of 39 unrelated FSHD patients with borderline D4Z4 repeat numbers and 102 healthy controls. Our aim was threefold: [1] to define the molecular diagnostic cut-off point between FSHD cases and the control population, [2] to describe the myopathic spectrum in patients with borderline D4Z4 repeat numbers and [3] to look for correlations between D4Z4 number and clinical severity. The results indicate that there is no definite D4Z4 diagnostic cut-off point separating FSHD, FSHD-like myopathies and controls. A broad myopathic spectrum with four phenotypes (typical FSHD, facial-sparing FSHD, FSHD with atypical features, non-FSHD muscle disease) was found in the borderline region. The expected correlation of D4Z4 repeat number and clinical severity was not found. Therefore the molecular test is of limited help to differentiate FSHD from FSHDlike muscle disorders when the D4Z4 number is n = >or= 8.

With a new enzymatic method, the dietary influence of oxalate, glycine, protein, and ascorbic acid on serum and urinary oxalate has been examined. Healthy and oxalate stone-forming subjects were compared. Two doses of sodium oxalate (130 and 400 mg daily) were administered. The high dose induced significant hyperoxaluria. No changes of serum oxalate were seen. Neither glycine (4.5 g daily) nor protein (50 g daily, 50% animal protein) had any effect on serum or urinary oxalate. Urinary oxalate excretion did not increase upon ingestion of large amounts of ascorbic acid (1–6 g daily), but serum oxalate levels were significantly elevated. The value of severe dietary restrictions concerning the compounds examined here seems to be questionable, as a significant increase of urinary oxalate excretion is lacking.

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Considerable progress has been made regarding pathogenesis, diagnosis and conservative management of urolithiasis. The cause of the disease can now be determined in nearly 80% of the patients. New stone formation may be prevented in the majority of patients by selective medical treatment. The metabolic, physicochemical and clinical effects of diet, thiazides, allopurinol, sodium cellulose phosphate and potassium-sodium citrate (Oxalyt-C) are described in detail. Intrinsic problems involved in clinical trial with recurrent stone formers are discussed.

The oxalate content of urine is determined by means of oxalate oxidase and simple pH measurement. The enzyme specifically decarboxylates oxalate, producing two moles CO 2 per mole oxalate. The CO 2 diffuses into an alkaline buffer solution (Hallson, P. C. & Rose, G. A. (1974), Clin. Chim. Acta 55, 29-39) in the closed reaction vessel, and reduces the pH value, which is measured with an electrode. Only 125 native urine is required to measure oxalate concentrations in the range of 80 / to 1.6 mmol/1 (corresponding to 7 to 144 mg anhydrous oxalic acid per liter). The limit of detection is 10 nmol oxalate, and the accuracy is 101% with a coefficient of variation of 6%.The method described is insensitive to various interfering factors, such as reducing and oxidizing substances, cloudy or colored samples. It is therefore also suitable for oxalate determination in food technology and plant breeding. Bestimmung von Oxalat in Urin mit OxalafrOxidase: Vergleich mit Oxalat-DecarboxylaseZusammenfassung: Der Oxalatgehalt von Urin wird mittels Oxalat-Qxidase durch einfache pH-Messung bestimmt. Das Enzym decarboxyltert spezifisch Oxalat, wobei je Mol Oxalat zwei Mol CO 2 entstehen. Durch Diffusion des CO 2 in eine alkalische Pufferlösung (Hallson, P. C. & Rose, G. A. (1974), Clin. Chim. Acta 55, 29-39) in geschlossenen Reaktionsgefäßen erniedrigt sich der pH-Wert, der mit einer Elektrode gemessen wird. Dabei genügen 125 Nativ-Urin, um Oxalatkonzentrationen im Meßbereich von 80 / bis 1,6 mmol/1 (entsprechend 7 mg bis 144 mg wasserfreie Oxalsäure je 1) zu erfassen. Die Nachweisgrenze liegt bei 10 nmol Oxalat, die Richtigkeit beträgt 101% bei einem Variationskoeffizienten von 6%. Die beschriebene Methode zeichnet sich durch geringe Störanfälligkeit gegenüber verschiedenartigen Analysenproben aus. Reduzierende und oxidierende Substanzen, trübes und gefärbtes Untersuchungsmaterial stören nicht. Sie ist deshalb auch für Oxalatbestimmungen in der Lebensmitteltechnologie und Pflanzenzüchtung geeignet.