Factors influencing the stability of acid-precipitated polyvalent Bordetella pertussis bulk suspensions.

According to the statistical analysis of the potency values of acid precipitated polyvalent bulk suspensions of Bordetella pertussis, the potency of suspensions decreased below 8 IU/30 IOU during storage for 5 to 9.8 years. The average annual decrease over a 13-year period was 2.03 IU/30 IOU. The periodicity in the decrease of potency values was assumed to be connected with changes in the quality of the casein hydrolysate ingredient of the medium. Periodic functions employed to approach potency values with limits of 1 SD falling within the range of 64--156% indicated that the potency decreased below 8 IU/30 IOU after 9 years.     

Reproductive behavior and social organization in the sand tilefish,Malacanthus plumieri

Synopsis Observations on the Caribbean sand tilefish, Malacanthus plumieri, were made during 3 dive trips in the Bahamas (Feb., 1986; July, 1986; Jan., 1987) at depths from 5 to 30 m. Eighteen mating groups contained 1 to 5 females (x = 2.9). Seven male home ranges (encompassing female ranges within mating groups) measured 250 to 700 m². Of 134 paired rises recorded between 1733 and 1925 h EST, 38 had an observed cloud of gametes. Mating times are presented in relation to time of sunset and depth of water. Courtship begins with conspicuous looping behavior of the male as he swims to a female. Close pairing, criss-crossing, and low rises (<1.5 m) often precede a high quivering upward swim (1.5 to 6 m) which culminates in the release of a cloud of gametes at the apex. M. plumieri is compared to the protogynous hermaphroditic razorfishes, Xyrichtys pentadactylus and X. martinicensis, with regard to social organization, size of male home ranges in exposed sandy habitats near coral reefs, sexual size dimorphism, and sex ratio.     

A factor synthesized by rabbit periosteal fibroblasts stimulates bone resorption and collagenase production by connective tissue cells in vitro

Unstimulated monolayer cultures of confluent rabbit periosteal fibroblasts synthesize a factor that stimulates bone resorption in vitro. Furthermore it stimulates rabbit chondrocytes and mouse osteoblasts to synthesize collagenase. The factor has no effect on dead bone in culture, and its activity on live bone is mediated principally by osteoclasts, since it is 75% inhibited by salmon calcitonin. Characterization of the factor by gel filtration and isoelectric focusing indicates an M_r in the range 15 000–25 000 and a pI corresponding to approx. pH 4.7. These biological and physicochemical properties are similar to those reported for a factor released by peripheral blood monocytes. However, whereas human monocyte factor in both the crude and partially-purified state exhibits interleukin-1 activity, crude and fractionated periosteal fibroblast-conditioned medium does not. This is the first report of a conditioned medium containing a molecule like the monocyte-factor which appears to have no interleukin 1 activity. The factor may be synthesized by a wide range of cell types, and could have an important role in mediating connective tissue degradation during both physiological and pathological resorption.     

Double cortical control acting upon activities of intralaminar thalamic cells

We report the effects exerted by the cortex upon the intralaminar thalamic nucleic, as revealed by reversible blockade of the cortex with spreading depression in awake rats. Extracellular recordings of spontaneous activity were made simultaneously at thalamic and cortical sites. The effect of peripheral receptive field stimulation was to decrease activity of intralaminar thalamic cells. Cortical recordings revealed the cortical regions affected by spreading depression. Two type of cells were identified depending on the changes in their sensorial responses during the cortical spreading depression propagation. The first exhibited a tonic facilitating cortical control when the cortical spreading depression was located at A 8.0 to A 10.0. The second type exhibited a disappearance of the sensorial responses when cortical spreading depression was located at A 4.0 to A 8.0 and also displayed the tonic facilitating control. This indicates that two different identified cortical regions influenced the thalamic activity.     

Diabetes-induced rat hyposensitivity to compound 48/80

Rat mortality and contractile responses of isolated tracheas to compound 48/80 from rats made diabetic 4 days before by a single intravenous injection of alloxan and from diabetic rats that had been treated with insulin 6 h before were compared with control animals. Diabetic animals and tracheal segments from diabetic rats were significantly less responsive to compound 48/80 than control and insulin-treated diabetic animals. On the other hand, diabetic animals have a lower quantity of peritoneal mast cells than control rats, and insulin restored the normal quantity of cells in diabetic animals. These data indicate that diabetes elicits an hyposensitivity to compound 48/80, possibly related to a diabetes-induced decrease in the mast cell count.