Effect of dopamine and atrial pacing on stunned myocardium

Low expression of the antimetastatic gene nm23 has been associated with shorter overall survival in breast cancer. To better understand the mechanism(s) of action of this protein, we compared the levels of the nm23 protein in 152 breast cancer samples with other factors known to be involved in metastasis or related to prognosis. There was no significant relationship between either of the nm23 isoforms and cathepsin D (Cat-D), urokinase plasminogen activator (uPA), its inhibitor (PAI-1), steroid hormone receptors or ploidy status. A marginal inverse correlation was observed between per cent S-phase and nm23-H1 expression (r = -0.193, P = 0.047) and a positive correlation was observed between uPA receptor (uPAR) and both nm23-H1 (r = 0.263, P = 0.0018) and nm23-H2 (r = 0.230, P = 0.0064). The nm23-H1 gene was transfected into MDA-MB-231 human breast cancer cells and 12 clones were selected, of which two were characterized extensively. We found no significant differences in Cat-D, uPA, PAI-1 or uPAR, as a function of nm23 expression in either the MDA-MB-231 cells or the transfected clones. Compared with the parent cell line, we did observe a dose-dependent decrease in growth factor-stimulated motility and a decrease in metastatic potential in two clones with four- and eightfold elevated nm23-H1 expression, whereas the proliferative activities were similar. We conclude that the decreased metastatic potential might be related to down-regulation of growth factor-stimulated motility.     

Quantification and identification of particle movement in epidermis after thermal injury

Skin samples from a rabbit hind limb were taken from controls and at 5 min, 2 and 6 hr after a mild thermal injury (60 degrees C for 1 min). Large aggregates of intercellular particles, usually ribosomal in appearance, were seen in 6 hr samples and were accompanied by some peripheral aggregates of particles and by granule-coated vesicles. These structures were present in earlier samples to a lesser extent and were absent from control material. Quantitative assessment showed that intercellular particles apparently increased up to 6 hr whereas peripheral aggregation was maximum at 2 hr. Histochemical analysis confirmed that the particles contained ribonucleoprotein. Other larger particles were seen occasionally and contained carbohydrate. Lymph draining the site showed cellular changes, little change in enzyme activities, and no aggregates of particles.     

Artificial feeding of Black infants

Analysis of milk formula feeds in a community where infant malnutrition is common, showed that overdilution of feeds is less frequent than expected. Many feeds were too concentrated. Modified and 'humanised' milks were more often and more seriously too strong than unmodified milks. An inadequate number and volume of milk feeds per day was probably more important in causing malnutrition than the strength of the feeds.     

Molecular genetic diagnosis of autosomal dominant polycystic kidney disease in a newborn with bilateral cystic kidneys detected prenatally and multiple skeletal malformations

We report a case of leiomyosarcoma of the pancreas. A spindle cell pattern at light microscopy, immunocytochemical reactivity with desmin, alpha-1-antitrypsin, vimentin and actin and ultrastructural features of smooth muscle differentiation help to establish the diagnosis.     

LH-RH-dependent synthesis of protein necessary for LH release from rat pituitary glands in vitro

Anterior pituitary glands of intact diestrous and gonadectomized female rats were incubated with a supramaximally active dose of LH-RH. Puromycin (P) and cycloheximide (C) did not consistently affect the LH release from glands of ovariectomized rats. In intact rats, LH release induced by LH-RH occurred in two phases, an initial one (relatively slow rate of release) and a secondary one (high rate of release). P and C had no effect on the initial phase, but prevented the secondary one. Pre-incubation with LH-RH prevented the effect of P and C added after 4 hours. Since P and C did not affect the total amount of LH present in media and hypophyses, the LH-released during the P- and C-sensitive phase is not newly formed LH. It is concluded that LH-RH induces the synthesis of protein which is necessary for LH-RH-induced LH release. The initial phase of LH release is made possible by protein already present in the glands at the beginning of the experiment.     

Pathomorphologic changes in the organs of rats following chronic inhalation exposure to liquid polyethylsiloxane

A chronic 90-day inhalation of polyethylsiloxane fluid at a concentration of 10 and 2 mg/m3 produced local irritation and general toxic effect on rats. Local irritation induced catarrhal-desqueamative tracheitis that was accompanied by a microfocal interstitial process in the lungs. The general toxic effect gave rise to interstitial myocarditis that was followed by focal cardiosclerosis and dystrophic lesions of vascular walls and areas of liver parenchyma. Changes in the thymus-lymph system and adrenal structure suggested prolonged protective tension of the animal body. A chronic 90-day inhalation of polyethylsiloxane at a concentration of 0.2 mg/m3 brought about no pathological lesions in the microstructure of animal organs.     

Alternative approach to a microprocessor teaching laboratory

A recent paper discussed the way in which microprocessors are being used for teaching computer science at Strathclyde University. This article discusses an alternative system being implemented at Rhodes University. The chief difference between the two is the attitude towards breakdowns.     

Urinary and kidney kallikrein in hypertensive rats

10 Patients with positive orthostatic dysregulation were investigated with regard to venous capacity, heart frequency and arterial blood pressure both lying down and sitting up. The venous capacity was reduced by 14% after dehydroergotamine (DHE) in the lying position, which is an expression of increased venous tone. There is no change in venous capacity following the administration of beta blockers in the lying position. Under orthostatic conditions beta blockers bring about an approximate normalization of the venous capacity reaction, whereas the abnormal response following placebo administration is only slightly altered by DHE.