Effect of constant light on male sterility in the cotton leafworm Spodoptera littoralis

Females of the cotton leafworm (Spodoptera littoralis) reared in long day conditions (LD 16:8 h) and mated to males kept throughout the whole period of development in continuous light (LL) oviposit very small numbers of mostly sterile eggs. It was found that in control males reared from the first larval instar in long day conditions there was a large accumulation of euperene sperm bundles in their testes on day 1 after imaginal moult. On day 10 of adult life the number of the sperm bundles was very small. In males kept from the first instar in continuous light there was also high number of sperm bundles on day 1 after imaginal moult but it did not decrease significantly on day 10 as was observed in controls. Transfer of different developmental stages of S. littoralis from long day conditions to continuous light resulted in a big difference in the density of eupyrene sperm bundles in their testes. In control insects reared through the whole of their development in long day conditions there was a significant decrease in the density of eupyrene sperm bundles on day 10 of adult life. By contrast, in males in continuous light, regardless of their developmental stage when transferred, there was either no change in density of sperm bundles in day 10 adults or there was a significant increase in comparison with day 1 adults. The highest density of eupyrene sperm bundles was observed in day 10 adults when they were transferred to continuous light shortly before moulting to the last instar (as day 4 larvae in the last stadium or day 1 pupae). Generally, the density of eupyrene sperm bundles on day 10 of adult development was about 2–2.5 times higher in males in continuous light then those under long day conditions. The results presented here indicate that the last larval instar and the pupa are the stages most sensitive to constant light treatment, which greatly reduces the amount of eupyrene sperm bundles released from the testes.     

Temporal pattern in consumption of the first drink of the day in alcohol-dependent persons

Loss of control over drinking and the craving for alcohol are cardinal signs of alcohol dependence. Our clinical practice indicates that these cravings do not occur randomly during the day, but at the same times each day for the same patient. To validate this hypothesis that alcohol-dependent patients have a circadian rhythmic craving in their desire for their first drink of the day, we asked 217 persons diagnosed as alcohol-dependent according to DSM-IV criteria to complete a questionnaire that surveyed whether this craving occurred at a fixed time each day. Of the respondents, 82% reported it did; 87% of them could state the time of day they consumed their first daily drink; and 80% reported that the time of their first drink of the day did not vary much from one day to the next. The most frequent time of consuming the first drink of alcohol was between 09:00 and 11:00 h, and it was independent of the subjects' sleep-wake routine (the delay between the hours of wake-up and the time of the first urge for alcohol was 3:45 +/- 3:30 h) and lunch or dinner time. This rhythmicity seems to be a pertinent criterion for alcohol dependence syndrome.     

The effects of partner togetherness on salivary testosterone in women in long distance relationships

The present study examined whether women's testosterone levels are influenced by being with a sexual and romantic partner after a period of sexual abstinence. Women in long distance relationships (n = 15) provided five saliva samples: at least 1 week before seeing their partner (and at least 2 weeks since their last visit), the day before seeing their partner, when they were with their partner but prior to engaging in sexual activity, the day after their first sexual activity, and 3 days after they were separated from their partners. Salivary testosterone was lowest when participants had been away from their partners for at least 2 weeks and highest the day before they were to see their partners and the day after sexual activity. Results from this study indicated that women's testosterone increased both the day before they were with their partners and they day after they first engaged in sexual activity. However, something about initially reuniting with their partners returned their testosterone to baseline levels, which may be an effect of being in the same location as a partner, or just a state fluctuation due to nervousness or other psychological state.     

Production of sexual morphs by apterous virginoparae of Myzus persicae (Hemiptera: Aphididae) in relation to pre- and postnatal exposure to short day conditions

The production of males and females by apterae of a holocyclic clone of Myzus persicae (Sulzer) was studied in the laboratory by transferring apterous virginoparae from long day to short day conditions at different stages of their pre- and post-natal development. Prenatal exposure was also examined in nine additional clones coming from different regions of Greece. By increasing the number of short day cycles at 17 degrees C, the aphids switched to male production earlier and produced more males. The highest mean number of male progeny was observed in apterae that were transferred to short day conditions 13-14 days prenatally. Apterae that were transferred to short day conditions after the fourth nymphal instar produced only females. Apterous virginoparae were produced by aphids that were transferred to short day conditions 0-1 days prenatally or postnatally. Aphids, given short days prenatally or in the first instar, produced alate female progeny that were all gynoparae. The later the instar aphids were transferred to short day conditions the fewer the gynoparae produced among their female progeny. A reduction in the total number of progeny and embryos per ovariole was observed as aphids were transferred to short day conditions in earlier stages of their development. The increase in male production, which follows the increase in the duration of long night exposure, was also observed in the additional eight out of nine examined clones.     

Pollen collecting behaviour of Apis mellifera during one day

We left pollen traps in two hives at Hinojos (Huelva, Spain) for two days. We removed the pollen loads accumulating on the trays of the trap four times each day and studied their botanical origin. In the two days of sampling, the number of pollen resources and their relative intensity of exploitation varied through the day. Pollen collection was more diverse in the central parts of the day, whereas the use of resources tended to be progressively more uniform through the day.     

Frequency of sex chromatin in the buccal smear of newborn females and their mothers during first six days after delivery.

The frequencies of sex chromatin in the buccal smear of the newborn females and their mothers were low on the first post-partum day and it increased gradually during the second and third day. By the fourth and fifth day it stabilized and the incidence of sex chromatin both in the mothers and the children became similar, although the frequency on the first day was significantly lower in the newborn. The incidences of pyknotic cells in the buccal smears of the newborns and their mothers were highest on day one and these declined rapidly in the following days. The significance of these findings have been discussed.     

Erasing genomic imprinting memory in mouse clone embryos produced from day 11.5 primordial germ cells

Genomic imprinting is an epigenetic mechanism that causes functional differences between paternal and maternal genomes, and plays an essential role in mammalian development. Stage-specific changes in the DNA methylation patterns of imprinted genes suggest that their imprints are erased some time during the primordial germ cell (PGC) stage, before their gametic patterns are re-established during gametogenesis according to the sex of individuals. To define the exact timing and pattern of the erasure process, we have analyzed parental-origin-specific expression of imprinted genes and DNA methylation patterns of differentially methylated regions (DMRs) in embryos, each derived from a single day 11.5 to day 13.5 PGC by nuclear transfer. Cloned embryos produced from day 12.5 to day 13.5 PGCs showed growth retardation and early embryonic lethality around day 9.5. Imprinted genes lost their parental-origin-specific expression patterns completely and became biallelic or silenced. We confirmed that clones derived from both male and female PGCs gave the same result, demonstrating the existence of a common default state of genomic imprinting to male and female germlines. When we produced clone embryos from day 11.5 PGCs, their development was significantly improved, allowing them to survive until at least the day 11.5 embryonic stage. Interestingly, several intermediate states of genomic imprinting between somatic cell states and the default states were seen in these embryos. Loss of the monoallelic expression of imprinted genes proceeded in a step-wise manner coordinated specifically for each imprinted gene. DNA demethylation of the DMRs of the imprinted genes in exact accordance with the loss of their imprinted monoallelic expression was also observed. Analysis of DNA methylation in day 10.5 to day 12.5 PGCs demonstrated that PGC clones represented the DNA methylation status of donor PGCs well. These findings provide strong evidence that the erasure process of genomic imprinting memory proceeds in the day 10.5 to day 11.5 PGCs, with the timing precisely controlled for each imprinted gene. The nuclear transfer technique enabled us to analyze the imprinting status of each PGC and clearly demonstrated a close relationship between expression and DNA methylation patterns and the ability of imprinted genes to support development.     

RADIATION EFFECTS ON CELL POPULATIONS IN THE INTESTINAL EPITHELIUM OF MICE AND ITS THEORY

Mice were exposed to 1000 R of X-rays to their trunks and sacrificed every day up to the tenth day after exposure. Cell counts were made on histological sections of the duodenum. The cell counts in the crypts were reduced to about 50% of the control value on the first day after exposure. The cell counts began to recover on the third day and an overshoot of 170% was observed on the fourth day; thereafter the crypt cell counts tended to return to the control level. The cell counts on the villi reached their minimum value on the third day after exposure. Following an overshoot on the sixth day, the villus cell counts returned to the control level by the tenth day. The above experimental results were analysed using a two-compartment model with a feedback term. A logistic proliferation was assumed for the proliferative crypt cells, while for the postmitotic villus cells the compartment was assumed to be a first in-first out type. The calculated results with this model are in general consistent with the experimental ones. The model seems to possess some essential features of the dynamics of cell renewal in the intestinal mucosa.     

Changes in ecdysteroid and juvenile hormone levels in developing eggs of Bombyx mori

It is well-known that insect eggs can contain very high concentrations of ecdysteroids, which undergo drastic changes during embryogenesis. We found that this is equally valid for juvenile hormones. Three juvenile hormone-immunoreactive compounds were observed in developing Bombyx mori eggs. They were assumed to be juvenile hormones 1, 2 and 3 according to their retention time in HPLC. These hormones underwent drastic and sudden changes. In the space of one day their concentration was seen to rise rapidly from an undetectable level up to as high as 4 × 10^?6 micromoles per mg of eggs. Their presence was detected as early as the first day of embryonic development, as well as during the blastokinesis period (day 5 to day 9) and in late embryos (day 12 to day 14). Their relative concentrations varied greatly. On two occasions, day 1 and day 8, all three hormones were simultaneously present. Moreover, juvenile hormone 3 was present during the blastokinesis period, either alone or in combination with hormone 2. The latter was the only hormone present in late embryos, before hatching. Thus, with regard to both ecdysteroids (ecdysone and 20-hydroxyecdysone) and juvenile hormones, each day of embryonic development displayed a different hormonal pattern. These patterns undoubtedly constitute a “hormonal code” of embryogenesis control. While 20-hydroxyecdysone can be assumed to trigger cuticulogenesis in embryos as it does in larvae, the effects of the other hormones as well as their possible interactions are questionable.     

Microspectrophotometric study of the lipid content in regenerating connective tissue

An experimental quantitative histological investigation was performed to study lipids in cellular elements of the regenerated connective tissue. Flap wounds were cut on the back of white mice and granulation tissue dissected 1, 3, 7, 14 30 and 60 days after the operation was investigated. Lipids and cellular elements were revealed with Sudan III-IV black B and Nile blue. Lipid quantity was estimated by means of a modified scanning integrating microphotometer. The greatest amount of lipids in the cellular elements of the granulation tissue was revealed on the 3d day of the experiment, total optic density (TOD) of lipids in leucocytes was 0.83, TOD in histiocytes--0.6. On the 7th day the amount of lipids decreased, their TOD in leucocytes was 0.6, in histiocytes--0.4. By the 14th day only phospholipids were revealed, in histiocytes their TOD was 0.3. In subsequent days phospholipid contents continued decreasing and by the 30th day their TOD was 0.2. By the 60th day, when a scar was formed in the wound, in fact, there were no lipids in the cellular elements. The microphotometric investigation performed demonstrated qualitative and quantitative characteristics of lipids in the cellular elements of the granulation tissue in dynamics and their close dependence on the time of wound healing. It was also revealed that the regenerative process was accompanied by decreasing lipid amount in the cellular elements, and this phenomenon could be used as a peculiar test to prognosticate the process of wound healing.     

Observation of mucosal pathology after praziquantel treatment in experimental Fibricola seoulensis infection in rats

It is well known that the duodenum of mice or rats infected with Fibricola seoulensis shows atrophy of villi (shortening, blunting, widening, fusion) and hyperplasia of crypts. This study was performed to observe healing process of these pathological changes after deworming with anthelmintic treatment. Albino rats infected each with 1,000 metacercariae of F. seoulensis were treated with single dose of 10 mg/kg praziquantel on day 15 post-infection. On day 1, 3, 5, 7, 15, 21 and 28 after the treatment, they were sacrificed and their duodenums were histopathologically studied. Control (uninfected) rats showed their normal finger-like projections of duodenal villi and well arranged crypts. In comparison, untreated (infected) controls revealed severe mucosal changes characteristic of villous atrophy and crypt hyperplasia in their duodenum. The damaged duodenal mucosa was found to restore its normal morphology after praziquantel treatment; until day 3 post-treatment the mucosa was severely atrophied; on day 5 long and slender villi sometimes appeared among the fused and stout ones; after day 15 the villi were in their normalizing process. From this experiment, it was shown that the mucosal changes in the duodenum of rats caused by F. seoulensis infection were completely reversible in 21-28 days after anthelmintic treatment.     

Comparative study of clonal growth and differentiation of mesenchymal stromal cells from rat fetal liver at different developmental stages

Fetal liver during period of its hematopoietic activity contains mesenchymal stromal cells (MSC) that are known to play a major role in establishing hematopoietic microenvironment. These cells are capable of clonal growing and multilineage differentiation, but only limited data exist about changes in their properties during prenatal development. We compared cloning efficiency of MSC from liver of 14, 16 and 20 day rat fetuses and evaluated their potentials to in vitro osteo- and adipogenesis and in vivo chondrogenesis after whole organ ectopic transplantation. Content of clonogenic MSC in suspension of liver cells was maximal in 16 day fetuses and to a lesser extent in 20 day ones. MSC derived from 16 day fetuses demonstrated maximal potential to estimated lineages. Osteogenic potential of MSC from 14 day fetuses was comparable to whereas their adipogenic and chondrogenic abilities were inferior to that from 16 day fetuses. Cells from 20 day fetuses had only weak adipogenic potency and failed to differentiate into osteogenic of chondrogenic pathways. The results indicate that both number and differentiation potential of MSC in developing rat liver correlate with dynamics of hematopoiesis in this organ. Detected changes may be ascribed to the decline of hematopoiesis in liver and acquisition its definitive functions.     

Effects of exposure of pregnant rats to TRH on development of the pituitary-thyroid axis in their progeny

TRH (10 and 1000 micrograms/kg body weight (BW] was injected ip into pregnant rats daily from day 0 to 20 of pregnancy, and the pituitary-thyroid axis of their pups (Mat-TRH rats) was examined on days 0, 4, 10, 21 and 90 after birth. The pituitary TSH content of male Mat-TRH rats was significantly lower on day 4, and higher on day 10 than that of control rats. The serum TSH was significantly higher on day 10 (except female 10 micrograms/kg group). An exaggerated TSH response to exogenous TRH (10 micrograms/kg BW; ip) was observed on day 10 (males, 1000 micrograms/kg group). The serum T4 level of female Mat-TRH rats was low on day 4 (1000 micrograms/kg group), and higher on day 10. On days 21 and 90, the levels of pituitary TSH, serum TSH and T4 in Mat-TRH rats were similar to those in controls, but the TSH response to TRH was still exaggerated (1000 micrograms/kg group). No significant difference between control and TRH-treated mothers was seen on days 10 and 90 postpartum except for a decreased pituitary TSH content on day 10 in the 1000 micrograms/kg group. It is concluded that repeated administration of TRH to pregnant rats shows an effect on the pituitary-thyroid axis function of their progeny in later life.     

The causation of two scent-marking behaviour patterns in female hamsters (Mesocricetus auratus)

Social, olfactory, and oestrous cycle influences on the frequency of flank-marking and vaginal marking were studied in female hamsters. Vaginal marking was more frequent in the presence of males or their odours than females or their odours. Vaginal marking frequency was greatest the day before oestrus (day 4), intermediate on days 2 and 3, and zero on the oestrous day. The probable sexual advertisement functions of vaginal marking were discussed. In contrast, flank-marking by females was stimulated more by other female odours than by male odours. The frequency of flank-marking was elevated by agonistic encounters and was reduced by sexual encounters. Flank-marking seems to have functions related to functions of aggression among hamsters.     

Circulating glucose, insulin and ketone bodies and enzymes of ketone body utilization in brain mitochondria from suckling rats treated with high L-thyroxine doses

The neo-T4 syndrome was induced by subcutaneous administration of a total dose of (150 micrograms) L-thyroxine (T4) to rats from their first day of live. Neo-T4 animals and their controls were sacrificed at 2, 4, 8, 11, 14, 22 and 25 days of age. A decrease in body weight was observed from the second day of life, and a decrease in brain weight from the eighth day of life in the neo-T4 animals. Blood glucose and plasma insulin levels were decreased from 2nd day through 22nd day of life. Total plasma ketone bodies and beta-OH butyrate levels increased in the neo-T4 animals with respect to controls. until 8th day, although acetoacetate increased only until 4th day. The activity of key enzymes in the ketone bodies utilization pathway (3-hydroxybutyrate dehydrogenase, 3-oxoacid CoA-transferase and acetoacetyl-CoA thiolase) were also measured in the animals brain. We found an activation of 3-hydroxybutyrate dehydrogenase until 11th day and 3-oxoacid CoA-transferase until 14th day, but no change in acetoacetyl CoA-thiolase was observed. Ketone bodies play a key role as energy substrates and precursors of brain lipids during the period of intense growth and myelination of the CNS. Considering the alterations described in this paper it seems that neo-T4 syndrome could be an interesting model for studying metabolism of those substances in brain.     

Morpho-functional alterations of the adrenal cortex in rats with active and passive strategy of adaptive behavior

In rats with the active (KHA strain) and passive (KLA strain) coping strategies, a post-stress depression develops respectfully on the 1st or 10th day after the inescapable stress. The present study revealed an increase of adrenal weight and blood corticosterone levels on a day following the inescapable stress, as well as marked fluctuations of blood glucose in one and five days post-stress in KHA rats. By the 10th day, these indices returned their basal levels. In contrast, the stress reactivity of KLA rats was lower in all terms and their corticosterone levels remained reduced on the 10th day after stress. In KLA rats, the fasciculate zone was reduced but reticulated zone grew in Ith day following the stress, while in KHA rats the inescapable stress resulted in growth fasciculate zone and concomitant reduction of reticulate zone, both evident on the 10th post-stress day. The data indicate that the development of post-stress depression in KLA rats is probably associated with exhaustion of adrenocortical function.     

The differentiation of prolactin cells in an organ culture of chick embryo adenohypophysis

We have studied differentiation of prolactin cells in explants of cephalic and caudal parts of Rathke's pouch of 4.5 day and 5.5 day old chick embryos after their incubation in vitro lasting for 7-8 days. Indirect immunofluorescence using an antiserum against bovine prolactin was used to detect prolactin cells in the cultures. Differentiation of prolactin cells was detected regularly in explants of the cephalic lobe of the adenohypophysis anlage in 5.5 day old embryos; under certain growth conditions prolactin cells were found in explants of the same lobe in 4.5 day old embryos. Prolactin cells were either absent or found in small numbers in cultures of the caudal part of adenohypophysis of 5.5 day old embryos. Our results provide evidence for the appearance of the committed precursors of prolactin cells in the Rathke's pouch at late stages of its formation and for their regional localization in the cephalic part of the anlage. This localization is in correspondence with the distribution of differentiated cells of this type in definitive adenohypophysis.     

Differential metabolic response to 48 h food deprivation at different periods of pregnancy in the rat

Since during pregnancy the mother switches from an anabolic to a catabolic condition, the present study was addressed to determine the effect of 48 h food deprivation on days 7, 14 and 20 of pregnancy in the rat as compared to age matched virgin controls. Body weight, free of conceptus, decreased with food deprivation more in pregnant than in virgin rats, with fetal weight (day 20) also diminishing with maternal starvation. The decline of plasma glucose with food deprivation was greatest in 20 day pregnant rats. Insulin was highest in fed 14 day pregnant rats, and declined with food deprivation in all the groups, the effect being not significant in 7-day pregnant rats. Food deprivation increased plasma glycerol only in virgin and 20 day pregnant rats. Plasma NEFA and 3-hydroxybutyrate increased with food deprivation in all groups, the effect being highest in 20 day pregnant rats. Food deprivation decreased plasma triacylglycerols in 14 day pregnant rats but increased in 20 day pregnant rats. In 20-day fetuses, plasma levels of glucose, NEFA and triacylglycerols were lower than in their mothers when fed, and food deprivation caused a further decline in plasma glucose, whereas both NEFA and 3-hydroxybutyrate increased. Liver triacylglycerols concentration did not differ among the groups when fed, whereas food deprivation caused an increase in all pregnant rats and fetuses, the effect being highest in 20-day pregnant rats. Lipoprotein lipase (LPL) activity in adipose tissue was lower in 20 day pregnant rats than in any of the other groups when fed, and it decreased in all the groups with food deprivation, whereas in liver it was very low in all groups when fed and increased with food deprivation only in 20 day pregnant rats. A significant increase in liver LPL was found with food deprivation in 20 day fetuses, reaching higher values than their mothers. Thus, the response to food deprivation varies with the time of pregnancy, being lowest at mid pregnancy and greatest at late pregnancy, and although fetuses respond in the same direction as their mothers, they show a specific response in liver LPL activity.     

Serum lipids in 8- to 35-day-old Zucker rats

The serum concentrations of triacylglycerols, cholesterol, and phospholipids were measured in 8- to 35-day-old Zucker rats. The animals were killed at 35 days of age. and their phenotype is determined on the basis of the weight of their inguinal subcutaneous fat pads. The serum lipid concentrations in all the rats increased from the 8th day of life, reaching a maximum at day 17 to 21. Weaning produced a large decrease in the concentrations of all three types of lipids. In the obese rats, the serum concentration of triacylglycerols was significantly raised from day 35 of life, that of cholesterol from day 21, and that of phospholipids from as early as day 8. At this age this latter concentration nevertheless cannot be used as a factor for detecting the obese phenotype.     

Modifications of plasma prolactin levels and catecholamine content in an ectopic anterior pituitary gland transplanted under the kidney capsule

In order to study the possible role on prolactin secretion of the catecholamines present in ectopic pituitaries, female rats bearing an anterior pituitary graft under the kidney capsule since day 30 of life and their sham-operated controls, were sacrificed at 1, 2, 4, 7, 15, 30, 45 and 60 days after the operation. Data obtained showed a significant increase in plasma prolactin levels in grafted rats versus controls from the 4th day on after the grafting (p less than 0.01) until the 60th day (p less than 0.001). Dopamine content in the ectopic pituitary of grafted rats was higher than in their own in situ pituitaries or on those of sham-operated rats until day 45 being similar to them afterwards. Norepinephrine was also present in the pituitary graft but was not detected in the in situ pituitaries. The grafting of an anterior pituitary gland in an ectopic location was able to induce changes in the local catecholaminergic control of the prolactin secretion.