Angeborene Fehlinnervationssyndrome

Congenital cranial dysinnervation disorders (CCDDs) are responsible for 1–2% of infant strabismus cases. Insufficient innervation and misinnervation of aberrant nerve fibres lead to motility restrictions and synkinesis. We present the most common CCDDs and explain their pathogenesis and the resulting clinical features. Furthermore, we emphasize essential diagnostic steps and treatment aspects.     

DNA-ploidy studies in a keratocyst undergoing subsequent malignant transformation

Using techniques that allow flow cytometry to be performed on tissue stored in paraffin wax, we have examined the DNA content of cells from an odontogenic keratocyst which underwent malignant transformation. On histological examination, the primary lesion was an odontogenic keratocyst showing dysplastic changes within the squamous epithelium. Flow cytometry revealed a prominent, abnormal DNA stemline, which was also present in the subsequent squamous cell carcinoma.     

Variations in serum thyroxine concentrations with time after an oral replacement dose

Serum thyroxine concentrations were measured sequentially in eight healthy male volunteers after the oral administration of one of two brand name, commercially available thyroxine tablets. In all cases, levels peaked at 2 hours and did not return to baseline values until 24 hours after dosing. From 2 through 10 hours, statistically significant elevations in serum thyroxine concentrations were observed. Such fluctuations may be important in evaluating laboratory results in patients receiving replacement doses of thyroxine.     

Difference spectrophotometric assay of nitrazepam in tablet formulations

A difference spectrophotometric procedure is described for the assay of nitrazepam in tablet formulations. The method is based on the measurement of absorbance at 282 nm of a solution of the tablet extract in 0.1 M hydrochloric acid (pH 1) relative to that of an equimolar solution in 0.1 M sodium hydroxide (pH 13). The method is precise and selective for nitrazepam in the presence of the tablet excipients and 2-amino-5-nitrobenzophenone, the principal hydrolysis product of nitrazepam. The absence of a constant isosbestic point in the difference spectrum of nitrazepam during hydrolysis in alkaline solution indicates the presence of a previously unrecognized intermediate hydrolysis product.     

Radiology of obesity surgery

Modern imaging modalities are the key to prompt evaluation of the efficacy and complications of obesity surgery. These are divided into the early and late complications of gastric restrictive surgery and intestinal bypass surgery.