The frequency of serological anti-zona pellucida activity in males, females and children.

945 human sera from children, fertile and infertile females, pregnant women and fertile and infertile males were tested for antibodies to porcine zona pellucida by immunofluorescence and the pronase-induced zona-lysis inhibition test. Positive sera were found in each of the groups examined, with a higher percentage of anti-zona activity in infertile, pregnant and menopausal women. There was no correlation between anti-sperm antibody titer and the incidence of anti-zona activity in either female or male human sera, nor did the occurrence of anti-zona activity correlate with a particular blood group type.

Uptake of 169Yb complexes in normal and tumour cells: influence of ligand and metabolic cell activity and stability of cellular association.

For better understanding of the accumulation of trivalent radiometal tracers in tumours, studies of uptake of different 169Yb complexes into cultured normal (V79/4) and tumour (KTCTL-2) cells were performed. Cellular uptake of 169Yb3+ is dependent on both the metabolic activity of the cells and the nature of the ligand used. Uptake of 169Yb3+ from the citrate complex is an active cellular transport process but not tumour-specific. The 169Yb-aminopolycarboxylic acid complexes are taken up via a different, unknown mechanism, and in higher amounts by the tumour cells than by the V79/4 cell line, but the general features of uptake were principally the same with the normal and the tumour cells. Uptake of the complexes studied leads to a stable association of cellular components, which is a good premise for the therapeutic use of trivalent radiometals.

A central pattern-generating network contributes to "reflex-reversal"-like leg motoneuron activity in the locust.

We introduce a new rhythmic preparation of the locust mesothoracic segment that exhibits long-lasting rhythmicity without pharmacological treatment. In most experiments, isolation of the locust mesothoracic ganglion from the anterior and posterior ganglia causes episodes of patterned activity to be generated in leg motoneurons that supply the femur-tibia (FT) joint. Flexor and extensor tibiae motoneuron pools exhibit alternating bursts of activity mostly composed of doublets and triplets of bursts. Motor activity during these episodes appears to be centrally generated because it persisted after complete deafferentation in 37% of the preparations; however, proprioceptive signals from the middle leg strongly influenced the patterning of motoneuron activity. Mimicking FT joint flexion by elongating the femoral chordotonal organ during an extensor burst terminates extensor activity and initiates flexor activity. The reverse is true for a mimicked extension during a flexor burst. This motor activity represents a reflex reversal that is typically observed in the locomotor state of the stick insect walking system. Our results provide evidence that this "reversed" reflex is caused by the action of central pattern-generating networks.

Evaluation of potential heart affine compounds by use of the isolated perfused rat heart.

99mTc-organocation complexes were screened for heart affinity using the isolated perfused rat heart. The 99mTc-I compounds are better extracted by the heart and retained in it than the 99mTc-III compounds. 99mTcCl2(DMPE)2+ shows low uptake (15%) and fast washout, but no impairment of uptake after incubation with human serum albumin(HSA), with a modified preparation, initial uptake is not much better (18%) but washout is clearly diminished. 99mTc(DMPE)3+ is taken up to a greater extent (33%) if administered solely, but when given in conjunction with HSA, uptake decreases to about 4% because of strong affinity of the complex to the protein, but this compound persists well in the tissue. Detergents like tween 80 and dioctylsulphosuccinate are able to cause higher uptake of 99mTc(DMPE)3+ even in the presence of HSA, thus indicating a diminished binding of the compound to the protein. 99mTc(CN-t-butyl)6+ shows very high uptake (80%) by the heart, which is only moderately diminished by addition of HSA (to 38%), and persists excellently in the myocardium. Basic features of the compounds such as accumulation in and elimination from the myocardium as well as plasma protein binding and their mutual relationships are well reflected by the isolated heart model.

Preparation of tin-albumin nanospheres for labelling with 99mTc and application in liver scintigraphy.

A modified method is described for the preparation of albumin nanospheres for labelling with 99mTc by investigating the absorption behaviour of tin as a reducing agent on albumin nanospheres. These albumin nanospheres can be used for studying the reticuloendothelial system, especially that of the liver. The labelling method is very simple, and the efficiency of labelling with 99mTc is higher than 97 per cent.

Hypoglycaemic activity of four plants used in Chilean popular medicine.

The hypoglycaemic activity of a 20% dried leaf infusion of Bauhinia candicans Benth. (Leguminosae), Galega officinalis L. (Leguminosae), Morus alba L. (Moraceae) and Rubus ulmifolius Schott. (Rosaceae), used for diabetes in Chilean popular medicine, was evaluated in alloxan and streptozotocin induced hyperglycaemic rats. In normal rats the different infusions did not modify significantly the glycaemia in the period studied, but in diabetic rats different results were observed, depending on the diabetogenic drug used. B. candicans and R. ulmifolius infusions elicited remarkable hypoglycaemic effects in both experimental models. B. candicans presented a greater decrease of glycaemia in alloxan diabetic rats (39%) and R. ulmifolius showed a similar activity in both alloxan and streptozotocin diabetic rats (28% and 29%). Activity-guided fractionation of R. ulmifolius showed that petroleum ether extracts elicited a marked hypoglycaemic effect (35%) in the streptozotocin induced model.