The structure of locomotor activity in bilobectomized cockroaches (Blaberus fuscus)

Summary The aperiodic activity patterns of bilobectomized cockroaches can largely be described by simple stochastic regularities: a) there are no correlations between the lengths of successive activity bursts and rest pauses, b) the probabilities for the transition from activity to rest and from rest to activity are time-independent. The activity sequence is strongly influenced by singular temperature steps or temperature cycles.     

Calf thymus ribonuclease H IIa activity lacks ribonuclease H specificity

Summary Less purified fractions of ribonuclease H IIa activity of calf thymus display divalent cation-dependent ribonuclease H activity and divalent cation-independent ribonuclease activity. Because the ratio of the two enzyme activities does not change during successive chromatographic procedures, we suggest that ribonuclease H IIa activity is indeed able to degrade both ssRNA and the RNA moiety of RNA·DNA-hybrids. Ribonuclease H IIa activity can therefore be differentiated from calf thymus ribonuclease H I and H IIb by its lack of ribonuclease H specificity. The native molecular mass of ribonuclease H IIa activity is between 23 and 28 kDa. Under denaturing conditions a 23 kDa-protein band copurifies with the enzyme activity suggesting that this enzyme is monomeric.     

Calf thymus ribonuclease H IIa activity lacks ribonuclease H specificity.

Less purified fractions of ribonuclease H IIa activity of calf thymus display divalent cation-dependent ribonuclease H activity and divalent cation-independent ribonuclease activity. Because the ratio of the two enzyme activities does not change during successive chromatographic procedures, we suggest that ribonuclease H IIa activity is indeed able to degrade both ssRNA and the RNA moiety of RNA.DNA-hybrids. Ribonuclease H IIa activity can therefore be differentiated from calf thymus ribonuclease H I and H IIb by its lack of ribonuclease H specificity. The native molecular mass of ribonuclease H IIa activity is between 23 and 28 kDa. Under denaturing conditions a 23 kDa-protein band copurifies with the enzyme activity suggesting that this enzyme is monomeric.     

Effect of physical exercise on the specific activity of carbonic anhydrase isozyme in human erythrocytes

Summary Significant decreases in the levels of both carbonic anhydrase type B and total esterase activity of human erythrocytes were observed after physical exercise (bicycle ergometer, 150 W for 30 min). Since carbonic anhydrase B-dependent esterase activity likewise decreased, the decrease in the total esterase activity would be caused by the decrease of carbonic anhydrase B activity. The specific activity of carbonic anhydrase B tended to decrease after the exercise. On the other hand no such effects were noted for carbonic anhydrase type C.     

Chronic hydrogen peroxide intake and peroxide metabolizing enzyme activities in some tissues of mice and rats

Chronic daily intake of 0.5% H2O2 in drinking water decreased Se-dependent glutathione peroxidase (Se-GSHPx) activity in rat skeletal muscle, kidney and liver. Non-Se GSHPx activity decreased in kidney. Deprivation of drinking water decreased Se-GSHPx activity in kidney and non-Se GSHPx activity in kidney and liver. H2O2 intake decreased activity of catalase in rat skeletal muscle. H2O2 intake or water deprivation caused no changes in these enzyme activities in mice.     

Possible role of intestinal alkaline phosphatase activity in thiamine transport.

Thiamine deficiency caused a marked decrease of intestinal alkaline phosphatase (al-Pase) activity, but had no effect on the Ca++-ATPase activity and Ca++-absorption in rats. The al-Pase activity was significantly decreased 1 h after oral administration of ethanol at 0.5 and 2.5 g/kg. In contrast, Mg++-, Ca++-and (Na+ + K+)-ATPase activities did not change after the administration of ethanol. These findings show that the al-Pase activity, unlike the Ca++-ATPase activity, is not related to Ca++-absorption. A possible role of al-Pase activity in the active transport of thiamine in the intestine was discussed.     

Specificity of action of phospholipases of rat intestinal mucosa]

The total homogenate of rat intestine is devoid of C or D phospholipase activity. At pH 6,5 in the presence of phosphatidylcholines, it exhibits a B phospholipase activity and in the presence of exogen lysophosphatidylcholines an A1 lysophospholipase activity. At pH 8,5 the intestinal mucous membrane of a rat shows an isolated A2 phospholipase activity.     

Individual housing of rats causes divergent changes in spontaneous and reactive activity

Summary Individually- and group-housed rats were compared in an animal activity meter, after several periods of different housing. Individually-housed animals showed a decreased spontaneous activity which could only be observed when the initial activity in response to the new environment had declined. It is concluded that the well-known phenomenon of isolation-induced hyperactivity is not due to an elevated spontaneous activity but to a hyper-reactivity.     

Strain differences in the pattern and intensity of wheel running activity in laboratory rats

Summary Wheel running activity rhythms of three inbred rat strains, ACI/Ztm, BH/Ztm, and LEW/Ztm, were compared in order to evaluate the effect of genetic differences on circadian rhythm parameters. Significant strain differences were found in the general pattern of the activity rhythms and their characteristic periodicities as well as in the amount and duration of wheel running activity and the timing of activity onsets and offsets. The results suggest that genetic differences exist in the coupling of the multiple circadian oscillators that generate the overall pattern of wheel running activity.     

The human urinary gastric inhibitor displays blood-group activity

Summary The human urinary glycoprotein with gastric antisecretory activity displays a marked blood-group activity corresponding to the blood-group of the subject examined. Several studies exclude the possibility that the activity is due to contaminants.     

Strain differences in the pattern and intensity of wheel running activity in laboratory rats

Wheel running activity rhythms of three inbred rat strains, ACI/Ztm, BH/Ztm, and LEW/Ztm, were compared in order to evaluate the effect of genetic differences on circadian rhythm parameters. Significant strain differences were found in the general pattern of the activity rhythms and their characteristic periodicities as well as in the amount and duration of wheel running activity and the timing of activity onsets and offsets. The results suggest that genetic differences exist in the coupling of the multiple circadian oscillators that generate the overall pattern of wheel running activity.     

Digestive enzymes of some earthworms

Summary 4 species of tropical earthworms differed with regard to enzyme activity. The maximum activity of protease and of cellulase occurred in the posterior region of the gut of the earthworms. On the averageOctochaetona surensis shows maximum activity andDrawida calebi shows minimum activity for all the enzymes studied.     

Fucosidosis and blood group substances in the urine]

Glycopeptide and oligosaccharide fractions obtained from fucosidosis urine contains more Lea activity (4-8 fold) than control urine. Both fucosidosis fractions also contained Leb and H activities, no A activity in contrast to the salivary and erythrocyte phenotypes (A, Le a+ b-). The amount of Leb activity is lower in both fractions (1) and (2) than that of Leb control children (4-16 fold decrease). Blood group A activity was not detected at any concentration used (less than or equal to 50 fold-concentrated urine) whereas A activity was found in (A, Le a- b+) control urine. On the contrary, both fucosidosis fractions contained H activity, whereas A (Le a- b+) control children fractions had none (less than or equal to 50-fold concentrated urine). H and Leb activity might originate from Lea precursor apart from the "non-secretory" type of the patient.     

Lactate dehydrogenase activity in cell subpopulations of 7,12-dimethylbenz(a)anthracene-induced mammary tumors

Heterogeneity of cells in a solid tumor prevents direct assessment of enzyme activity of cell subpopulations by conventional homogenization techniques. Lactate dehydrogenase (LDH) activity before and after ovariectomy and following estrogen supplementation in density-defined cell subpopulations from DMBA-induced mammary tumors was determined. Different levels of LDH activity were found in different cell subpopulations. After ovariectomy the level of LDH activity declined. Restoration of the circulatory estrogen level resulted in increased enzyme activity. The highest level of LDH was found in a band which consisted mainly of poorly differentiated cells. This cell subpopulation also tended to be more responsive to endocrine manipulation.     

稻草还田少免耕对稻田土微生物及酶活性的影响

为探明少免耕和稻草覆盖对土壤生物特征的影响,合理利用稻草覆盖及耕作制度来保障土壤的可持续利用,研究了33％（约2500ks／hm^2）、67％（约5000kg／hm^2）、100％（约7500kg/hm^2）稻草覆盖少免耕对稻田土微生物区系及活性的影响。定位试验2年后,少免耕与稻草覆盖提高了稻田土好气性细菌数量、真菌数量和微生物活度,但厌气性细菌和放线菌的数量则略减少。33％和67％稻草还田时,翻耕土壤的好气性细菌和厌气性细菌数量均高于免耕和少耕土壤。33％稻草还田时,免耕和少耕土壤的放线菌和真菌数量均高于翻耕土壤。同时,少免耕提高了土壤木聚糖酶、纤维素酶、蛋白酶、脲酶、过氧化氢酶的活性,也提高了土壤微生物活度、氨化作用强度和硝化作用强度。少量稻草还田少耕要优于少量稻草还田翻耕和免耕。     

Dipeptidyl aminopeptidase in neonatal rat brain regions

Summary Changes in the activity of dipeptidyl aminopeptidase in rat pituitary gland and various brain regions were examined at 3, 5 and 20 weeks of age. The enzyme activity per g tissue wet weight in pituitary gland was the highest of all tissues studied. Subcellular distribution of the activity was also studied. The highest enzyme activity was found in a crude mitochondrial fraction including synaptosomes.     

Evidence of protein kinase activity in 2 murine oncornaviruses]

A protein kinase activity has been detected in two strains of murine Oncornaviruses, MSV/MLV and EFV. This activity phosphorylates not only endogenous viral proteins but also exogenous substrates (histones and phosvitin). The stimulation of enzyme activity by detergents along with the increase of specific activity in viruses treated with trypsin during purification suggest that the enzyme is located in the viral particle.     

Effects of Freund's complete adjuvant on the dirunal rhythms of neuroendocrine processes and ornithine decarboxylase activity in various tissues of male rats

The aim of this study was to investigate the effects of Freund's complete adjuvant (FCA) on the diurnal rhythms of hormonal parameters in serum and ornithine decarboxylase (ODC) activity in various tissues of male rats. On days 1–2 after FCA, increase of ODC activity (used to evaluate the level of activation) was observed in the hypothalamus, pituitary gland, adrenal medulla, adrenal cortex, liver and lymphoid tissues, while the ODC activity in the kidney was reduced. This was accompanied by an increase in serum corticosterone. On days 3–4 after FCA, ODC activity remained elevated in the pituitary gland, liver and lymphoid tissues, while the ODC activity in the testes and panceas was reduced; kidney ODC activity returned to baseline. This was associated with increased serum levels of prolactin (Prl) and luteinizing hormone, but decreased growth hormone, testosterone and insulin. The increase in ODC activity in the thymus, as well as the reduced ODC activity in the testes and kidney, can be obtained with paraffin. Furthermore, bromocryptine microcapsules (CBLA) reduced the FCA-induced increase of ODC activity in the pituitary gland, liver and lymphoid tissues (days 3–4) but did not affect the changes in other tissues. The increase in ODC activity in the pituitary gland, liver and lymphoid tissues is specific for FCA. A role for Prl in the induction of ODC in liver and lymphoid tissues is suggested by the fact that CBLA suppresses this enhancement.     

The human urinary gastric inhibitor displays blood-group activity.

The human urinary glycoprotein with gastric antisecretory activity displays a marked blood-group activity corresponding to the blood-group of the subject examined. Several studies exclude the possibility that the activity is due to contaminants.     

Eyestalks control of diurnal rhythm of acetylcholinesterase activity in the crabOziotelphusa senex senex

Summary The crab (Oziotelphusa) displays a diurnal rhythm of acetylcholinesterase activity, with maximal activity around midnight, alternating with minimal activity at noon. Bilateral eyestalk ablation eliminates the diurnal rhythm of acetylcholinesterase activity.Acknowledgments. We wish to express our gratitude to CSIR, New Delhi for providing financial support to PSR. Reprint requests should be addressed to Prof. R. Ramamurthi.