Use of X-ray micro tomography to study the microstructure of loose-packed and compacted milk powders.

The use of X-rays to evaluate food microstructure has developed considerably in recent years. In this work we used X-ray micro tomography (XMT) to visualize the microstructure of loose-packed and compacted samples of spray-dried skim milk powder (SMP) and whole milk powder (WMP) and to quantify the proportion of both interstitial and occluded air voids in each sample. Visual scrutiny of the acquired XMT images showed details of the microstructure of the milk powders such as the spherical morphology of the particles, the size of the particles and internal air voids of various sizes. Within loose-packed powders, the proportion of air voids was higher (13% average) in WMP than in SMP. This was reversed in the compacted powders, in which the proportion of air voids was higher in SMP. The disparity in the proportion of air voids in both loose-packed and compacted samples of SMP and WMP was attributed to the size, shape and surface properties of the particles.

Remnants of a 35-year-old ventriculo-atrial shunt presenting as orofacial pain.

A 36-year-old man presented to his general dental practitioner with pain in the right jaw and neck. This was initially treated as a dento-alveolar abscess. Three days later, he presented to the oral and maxillofacial unit with neck swelling to the right side. An ultrasound confirmed the swelling was due to thrombosis associated with remnants of a ventriculo-atrial (VA) shunt in the right internal jugular vein. This had been placed during the patient's infancy and apparently removed at the age of 8 years. The patient was treated conservatively with warfarin and Coamoxyclav. The patient made a full recovery and was placed on long-term anticoagulant therapy. The introduction of cerebral spinal fluid shunt procedures for the treatment of hydrocephalus has resulted in a reduction in the mortality rate from 80% to 15-20%. Various thrombo-embolic complications have been described with VA shunts. A thorough medical history is absolutely essential in order to identify uncommon causes of common presentations.

Isolated hypoglossal nerve palsy due to a vascular anomaly.

The case of a patient with an unusual cause of an isolated hypoglossal nerve palsy is presented. Magnetic resonance (MR) imaging demonstrated marked dilatation and ectasia of the right vertebral artery and basilar artery, thereby causing compression of the brainstem. It is therefore proposed that a dilated vascular loop compression of the nerve rootlets, as they exit the medulla, has caused the hypoglossal nerve palsy. This case demonstrates that excellent images can be obtained from MR imaging, and also emphasises that other pathologies must be considered in the differential diagnosis of hypoglossal nerve palsy.

Tuberculous parotitis.

Tuberculosis, though rare, should be considered in the differential diagnosis of a diffuse swelling of the parotid with enlarged cervical glands, particularly in young, feverish adults.

Theophylline assay on Kodak Ektachem DTSC--performance and interference by structurally-related compounds and salicylate.

Theophylline was measured with a Kodak Ektachem DTSC using its property of uncompetitive inhibition of alkaline phosphatase. Within- and between-batch reproducibility was satisfactory. Agreement with consensus mean values on quality assessment samples was good as was agreement on patients' samples with a high performance liquid chromatography reference method and an automated fluorescence polarisation immunoassay. At therapeutic theophylline concentrations, no interference was seen with caffeine, theobromine, 1,7-dimethylxanthine, 1,3-dimethyluric acid or 3-propylxanthine. 3-methylxanthine (a theophylline metabolite) gave a positive bias but the concentrations of this metabolite found in serum are such that the clinical significance of this finding is questionable. Salicylate at concentrations which might be found during therapy for paediatric rheumatoid arthritis also gave a positive bias.