A rapid and sensitive method for estimating low concentrations of albumin in human urine

A chemiluminescence immunoassay has been developed for the measurement of albumin concentrations in human urine, as an indicator of diabetic nephropathy. The assay involved competition between analyte albumin and an acridinium ester labelled albumin tracer for binding to a rabbit (anti-human albumin) antibody. Immune complexes were separated using sheep (anti-rabbit immunoglobulin G) antibodies coupled to paramagnetic particles. The total incubation time was ninety minutes at room temperature followed by sedimentation and washing of the solid-phase using a magnetic rack. Chemiluminescence emission was quantified rapidly (2 s) using a commercially available luminometer. The assay was sufficiently sensitive (10 ng/ml) for the detection of microalbuminuria with the advantages of rapidity and use of stable reagents. The assay correlated well with both RIA and rate nephelometry.     

Prolactin response to thyrotropin-releasing hormone stimulation and dopaminergic inhibition in benign breast disease

Pituitary function was tested in predefined clinical groups of benign breast disease under strictly controlled clinical and laboratory conditions. Two different tests of prolactin storage and control mechanisms, direct stimulation by thyrotropin-releasing hormone (TRH) and inhibition of dopaminergic control by domperidone, indicate a significant abnormality in patients with severe cyclical mastalgia and nodular breast disease (P less than 0.05 and P less than 0.002), but not in those with noncyclical mastalgia. No abnormalities of thyroid function were found.     

The effect of sinusoidal vibration on the uniformity of packing of powder beds

Sinusoidal vibration, at a number of defined sets of conditions, has been applied to packings of certain particle size fractions of lactose. The distribution of local porosity within these vibrated packings was determined using a gamma-ray attenuation technique, and could be compared with porosity data for samples not subjected to vibration. It was found that the application of vibration in a vertical mode markedly increased the uniformity of packing; horizontal vibration was less effective in this respect. The relationship between local porosity and position with a packing, observed in most non-vibrated samples, was generally absent from vibrated packings.     

Cortical structure of the pig mandible after the insertion of metallic implants into alveolar bone.

The effect of tooth extraction and endosseous metallic implants on the bone structure of adult pigs was studied using both densitometric and microradiographic techniques. Similar methods were used to study the bone structure of both growing and adult pig mandibles. The use of tetracycline and ³²P-labelled phosphate in vivo indicated that the porous bone deposited periosteally is the most metabolically active bone during growth. This formation occurs over almost the entire surface of the body of the mandible throughout life but, despite an overall density increase with age, the internal structural pattern established during development, is maintained. Both tooth extraction and the introduction of metallic endosseous implants stimulated further remodelling. Despite the different responses to tooth extraction and implantation, the internal structural pattern remained constant.     

Transient neonatal hyperthyrotrophinaemia: a serum abnormality due to transplacentally acquired antibody to thyroid stimulating hormone

In a screening programme for neonatal hypothyroidism an otherwise healthy female infant was found to have a high concentration of thyroid stimulating hormone in a filter paper blood spot and in serum. A high concentration was also found in the maternal serum. Mother and baby were both biochemically euthyroid with normal serum thyroxine concentrations. The apparently high concentration of thyroid stimulating hormone in the mother was due to the presence of an IgG antibody that bound to human but not bovine thyroid stimulating hormone. Maternal serum inhibited the action of human thyroid stimulating hormone in an in vitro bioassay for the hormone. It is suggested that the baby acquired the antibody transplacentally, especially as the concentration of thyroid stimulating hormone subsequently fell. It is concluded that maternal serum should be assayed for thyroid stimulating hormone when a neonate is found to have a high concentration of the hormone and a normal concentration of thyroxine to establish the incidence of this finding and to avoid inappropriate replacement treatment.     

Treatment of bone disease after jejunoileal bypass for obesity with oral 1 alpha-hydroxyvitamin D3.

The effects of oral 1 alpha-hydroxyvitamin D3 have been investigated in 12 patients with bone disease after jejunoileal bypass for obesity. Bone histology became normal or improved greatly after four to 12 months' treatment in eight patients but showed little change or worsened in four. There was a significant rise in plasma calcium and fall in plasma alkaline phosphatase concentration with 1 alpha-hydroxyvitamin D3 therapy in the patients with a good histological response. Administration of metronidazole and cotrimoxazole to two patients who had failed to respond to 1 alpha-hydroxyvitamin D3 resulted in clinical and biochemical improvement; in one of these patients histological improvement was also documented. It is concluded that oral 1 alpha-hydroxyvitamin D3 can be effective in healing post-bypass bone disease; the failure of some patients to respond may be related to bacterial contamination of the small intestine and in those patients antibiotics may also be indicated.