Fluctuations of grass pollen content in the atmosphere of East Perugia and meteorological correlations (year 1989)

Summary Gramineae pollination from a pollen monitoring station located in the eastern suburb of Perugia and meteorological correlations are reported. The data refers to the year 1989. Grass pollen peak pollination was from May to July; in this period the influence of relative humidity and of temperature on pollen concentration was very high. Phenological observations, to identify the time of maximum stamen extension in the most common genera in the area, are also reported. During the period of investigation the counts of pollen grains over four-hour periods showed a regular diurnal rhythm with peaks of concentration in the four-hour period 16.00–20.00. Aerosporological data and meteorological data related to four-hour periods were correlated following different criteria.     

Aminergic neuron systems of lobsters: morphology and electrophysiology of octopamine-containing neurosecretory cells

In the American lobster (Homarus americanus) the biogenic amines serotonin and octopamine appear to play important and opposite roles in the regulation of aggressive behavior, in the establishment and/or maintenance of dominant and subordinate behavioral states and in the modulation of the associated postural stances and escape responses. The octopamine-containing neurosecretory neurons in the thoracic regions of the lobster ventral nerve cord fall into two morphological subgroups, the root octopamine cells, a classical neurohemal group with release regions along second thoracic roots, and the claw octopamine cells, a group that selectively innervates the claws. Cells of both subgroups have additional sets of endings within neuropil regions of ganglia of the ventral nerve cord. Octopamine neurosecretory neurons generally are silent, but when spontaneously active or when activated, they show large overshooting action potentials with prominent after-hyperpolarizations. Autoinhibition after high-frequency firing, which is also seen in other crustacean neurosecretory cells, is readily apparent in these cells. The cells show no spontaneous synaptic activity, but appear to be excited by a unitary source. Stimulation of lateral or medial giant axons, which excite serotonergic cells yielded no response in octopaminergic neurosecretory cells and no evidence for direct interactions between pairs of octopamine neurons, or between the octopaminergic and the serotonergic sets of neurosecretory neurons was found.     

Impaired beta-cell regeneration in perinatally malnourished rats: a study with STZ.

We investigated the mechanisms implicated in beta-cell mass reduction observed during late fetal and early postnatal malnutrition in the rat. Beta-cell regeneration, including proliferation and neogenesis, was studied after neonatal beta-cell destruction by streptozotocin (STZ). STZ was injected at birth and maternal food restriction was continued until weaning. Beta-cell mass, proliferation, and islet number were quantified by morphometrical measurements on pancreatic sections in STZ-injected normal (C-STZ) and malnourished (R-STZ) rats, with noninjected C and R rats as controls. At day 4, only 20% of the beta cell-mass remained in C-STZ rats. It regenerated to 50% that of noninjected controls, mainly through active neogenesis, as shown by the entire recovery of islet number/cm(2), and also through moderately increased beta-cell proliferation. In contrast, beta-cell mass from R-STZ animals poorly regenerated, despite a dramatic increase of beta-cell proliferation, because islet number/cm(2) recovered insufficiently. In conclusion, perinatal malnutrition impairs neogenesis and the capacity of beta-cell regeneration by neogenesis but preserves beta-cell proliferation, which remains the elective choice to increase beta-cell mass. These results provide an explanation for the impaired capacity of malnourished animals to adapt their beta-cell mass during aging or pregnancy, which aggravate glucose tolerance.     

The formation of L-3-phosphoglyceric acid by ribulose-1,5-bisphosphate carboxylase

A sensitive and reliable method to determine the stereochemical composition of 3-phosphoglyceric acid is presented. Results obtained with this method show that 3-phosphoglyceric acid formed in the ribulose-1,5-bisphosphate carboxylase reaction is a mixture of 10% L-3-PGA and 90% D-3-PGA.     

The effects of Eleutherococcus senticosus and Panax ginseng on steroidal hormone indices of stress and lymphocyte subset numbers in endurance athletes.

A clinical trial was undertaken to investigate the effects of Eleutherococcus senticosus (ES) and Panax ginseng (PG) on competitive club-level endurance athletes engaged in their normal in-season training. Participants were matched for training stress and received a 33% ethanolic extract (8 mL/day) containing either ES, PG (equivalent to 4 g and 2 g/day of dried root, respectively), or a placebo. A pre-test and post-test were used to evaluate the effects of six weeks of supplementation on cortisol, testosterone, and testosterone to cortisol ratio (TCR) as well as circulating numbers of total T-cells, T-helper cells (CD4), T-suppressor cells (CD8), CD4 to CD8 ratio, natural killer cells, and B lymphocytes. None of the immune system variables changed significantly nor showed any clear trend from pre to post test in any of the treatment groups. No significant change in testosterone, cortisol or TCR was observed in the PG group. In the ES group, however, TCR decreased by 28.7% from 0.0464 to 0.0331 (P=0.03). The main contribution to this decrease appeared to be a non-significant (P= 0.07) 31% trend towards increased cortisol rather than a very small non-significant (P = 0.36) 7% decrease in the calculated mean for testosterone. This result suggested that contrary to initial expectation, ES increased rather than decreased hormonal indices of stress, which may be consistent with animal research suggesting a threshold of stress below which ES increases the stress response and above which ES decreases the stress response.     

Influence of hirudin on the consumption of antithrombin III in experimental DIC

The effect of hirudin and heparin on thrombin-induced consumption of antithrombin III, fibrinogen and platelets was studied in a rat model. Antithrombin III is consumed by tolerated thrombin doses by about 20 per cent. Hirudin and heparin ameliorate the consumption of fibrinogen and platelets at the low thrombin dose used. At high thrombin doses, tolerated only during simultaneous administration of exogenous inhibitors, heparin leads to markedly increased consumption of anti-thrombin III, whereas hirudin does not. With either kind of treatment, the thrombin effect on fibrinogen and platelets is inhibited, however, hirudin acts independently of a cofactor in contrast to heparin.