Thiazolidinediones Regulate the Level of ABC Transporters Expression on Lung Cancer Cells.

ATP binding cassette (ABC) transporters related to multidrug resistance (MDR) actively efflux various xenobio-tics from the cells across the cell membrane and decrease a drugs efficiency. Lung cancer is the leading cause of death among all types of cancer in the Czech Republic, and its incidence is still rising. Ciglitazone, rosiglitazone and troglitazone belonging to PPARγ agonist family (formerly used in diabetes mellitus treatment) were selected to investigate their capability to influence expression of ABC transporters on lung cancer cells. Therefore, the effect of PPARγ of agonists on transcription of following ABC transporters was investigated: multidrug resistance protein 1 (MDR1), multidrug resistance-associated protein 1 (MRP1), and breast cancer resistance protein (BCRP). We have investigated if these PPARγ agonists are substrates of ABC transporters using HL60 and HL60 derived cell lines (HL60-MDR1, HL60-MRP1, PLB-BCRP) by cytotoxicity test WST-1. We have mapped the changes in mRNA expression level of those transporters in A549 and HEK293 cells after PPARγ agonists treatment using quantitative reverse transcription real-time PCR (qRT-PCR). All three PPARγ agonists serve as substrates to at least one ABC transporter under study. PPARγ activation correlates with up-regulation of PTEN which may modulate the expression of ABC transporters through PI3K/ Akt signaling pathway. We have shown that rosiglitazone and troglitazone inhibit mRNA expression of MDR1 transporter in both cell lines whereas the expression of MRP1 in HEK293 cell was up-regulated after rosiglitazone treatment and the expression of MDR1 was upregulated after ciglitazone treatment.

Biologic importance and prognostic significance of selected clinicopathological parameters in patients with oral and oropharyngeal squamous cell carcinoma, with emphasis on smoking, protein p16(INK4a) expression, and HPV status.

The aim of this study is to evaluate the biologic importance and prognostic significance of selected clinicopathological parameters in patients with oral (OSCC) and oropharyngeal (OPSCC) squamous cell carcinoma, with emphasis on smoking, protein p16(INK4a) (p16) expression, and human papillomavirus (HPV) status.The study sample consisted of 48 patients with OSCC and 44 patients with OPSCC. Half of the patients were nonsmokers and the other half were gender-, age- and tumor localization-matched smokers. p16 expression was detected in 17/48 (35 %) OSCCs and in 36/44 (82 %) OPSCCs and HPV DNA was present in 7/48 (15 %) OSCCs and in 35/44 (80 %) OPSCCs. The sensitivity and specificity of p16 expression for HPV DNA presence were 0.74 and 0.88, respectively. The OPSCCs were more frequently basaloid (p < 0.001) while the OSCCs were more frequently conventional (p < 0.000001). The OSCCs were more likely to recur locally and to be the cause of death (p = 0.009 in both parameters).The HPV-positive tumors were more frequently localized in oropharynx, were basaloid SCCs and were p16- and HPV-positive (p < 0.000001 in all 4 parameters). The HPV-negative tumors were more frequently localized in oral cavity (p < 0.000001), more frequently asociated with local, regional and locoregional recurence (p = 0.011, p = 0.019 and p = 0.030, respectively) and with tumor-related death (p = 0.003). There was no significant difference with regard to smoking history (p > 0.05). The survival of patients with HPV-positive tumors was significantly longer (median 112 months; 95% CI 54 - 112 months) than that of patients with HPV-negative tumors (median 17 months; 95% CI 12 - 39 months) (p < 0.001). The HPV status of OSCC/OPSCC is an important biological and prognostic parameter and should be examined in all cases, using PCR or immunohistochemical detection of surrogate marker p16. Smoking itself does not seem to be an important prognostic factor.

Weaning of young rats: effect of time on behavior.

Male rats were weaned on the 15th, 16th, 17th, 25th, and 30th day of postnatal life. The rate of elaboration of the conditioned reflex at 8 months of age and the stability of the memory trace at 12 months were studied. Compared with rats weaned at 30 days of age, those weaned on day 15 elaborated the conditioned reflex much more slowly and the memory trace was less firm. Rats weaned on days 16 and 17 elaborated the conditioned reflex more quickly than rats weaned on day 15 but more slowly than those weaned on day 30. In all groups the memory trace showed the same stability and was significantly firmer than in rats weaned on day 15. The higher nervous activity of rats weaned at the age of 25 days more nearly resembles that of rats weaned at 15 days than the 30th day.

[Role of human papillomavirus in carcinogenesis of head and neck cancer]. / Uloha lidského papillomaviru v karcinogenezi nádoru hlavy a krku.

Head and neck squamous cell carcinomas develop predominantly in individuals over 40 years of age and more frequently in males. The strongest risk factors for this disease are long-term abuse of tobacco products and alcohol. Recently, several reports of increasing incidence of head and neck cancer in atypical population groups of females or young adults have been published, often in patients with no history of smoking or alcohol abuse. It seems highly probable that at least in a part of these cases, human papillomavirus (HPV) played an important etiological role. Some of the HPV types were proved to cause certain anogenital carcinomas, particularly cervical carcinoma. It seems that in some cases these very HPV types are also involved in head and neck carcinogenesis. Published data on the prevalence of HPV infection in head and neck squamous cell carcinomas vary in different studies. However, it is generally understood that the infection is more commonly present in carcinomas of the oropharynx and palatine tonsils than in oral cavity carcinomas. The hypothesis of sexual transmission of oncogenic HPV types has yet to be confirmed. It is not clear whether current HPV vaccines could possibly decrease the incidence of head and neck squamous carcinomas.

Influence of litter size on the RNA content of VMH and LHA in preweaning rats.

The nutritional status in the early postnatal period may significantly influence the development and functional activity of food intake regulating mechanisms. Therefore we investigated the weight gains and total RNA content of the ventromedial (VMH) and lateral (LHA) hypothalamic cells of rat pups in normal litters (8 pups/nest) and in reduced litters (2 pups/nest) reared permanently (from birth to weaning) or temporarily (from 1st to 5th day) in reduced nests. A significant decrease of weight gains was found in pups reared in reduced litters during the first 5 days which resulted in significant differences of body weight between the pups from normal and reduced litters on 5th day of life. On the 15th and 30th days, there were no significant differences in body weight between these animals, but the RNA content in VMH cells of pups reared in reduced litters was significantly increased on the 15th and 30th days. The RNA content in the LHA cells was unchanged. The results show that reducing a rat litter to 2 pups caused short-term undernutrition leading to permanent changes of the RNA content in the VMH neurons. The possible consequences of the permanently changed RNA content of this hypothalamic structure are discussed.

Influence of early undernutrition in rats on their body fat and RNA content in VMH neurons.

The RNA content of the ventromedial hypothalamus (VMH) and lateral hypothalamic area (LHA) neurons, and the epididymal, retroperitoneal, and liver fat content of 150-day-old male rats submitted to neonatal undernutrition, were investigated. The neonatal undernutrition was carried out by two different ways. First, by reducing the litters to two pups per nest from birth to weaning. The pups from normal litters (eight pups/nest) served as controls. Secondly, by separating half of the pups (four pups) from normal litters for 8 h daily during the first 5 postnatal days. The remaining nonseparated pups served as their controls. The data show that both groups of early undernourished pups had a significantly increased RNA content in the VMH neurons (RNA content in the LHA neurons was unchanged) and a significantly decreased epididymal, retroperitoneal, and liver fat content in comparison with their controls. The results indicate that early undernutrition leads to a permanent increase in the functional activity of VMH and alteration in fat metabolism in rats.

Food intake control and RNA content of hypothalamic neurons in infant rats.

The influence of glycerol, glucose and lysine administration on the total RNA content in individual neurons of the ventromedial hypothalamus (VMH) and lateral hypothalamus area (LHA) in infant male rats was studied. Sixty minutes after administration, the total RNA content of the VMH neurons significantly decreased--from 13th day after glycerol and from 17th day after the glucose and lysine administration. The total RNA content of LHA neurons significantly increased from 17th day after glycerol and glucose and on 25th day after lysine administration. The noted changes of the RNA content, and especially the changes of the RNA proportion in these hypothalamic regions are well corresponding with the onset of the hypophagic effect of glycerol, glucose and amino acids in infant rats. The oppositional changes of the RNA content of VMH and LHA neurons are in conformity with the different role of these hypothalamic centers in food intake control.

RNA content of neurons in the ventromedial nuclei and lateral hypothalamic area relative to feeding status.

The total RNA content of hypothalamic and cortex neurons in relation to the feeding status of adult male Wistar rats was studied. Experimental conditions including food deprivation (12 and 24 hours) and relative satiation (short-term refeeding, glucose or glycerol administration) changed in different ways the total RNA content of the neurons in the ventromedial hypothalamic nuclei (VMH) and in the lateral hypothalamic area (LHA) with respect to fasting or satiety. Only the long-term absence of food (24 hours) significantly increased the total RNA content of the VMH cells, while the RNA content of the LHA neurons significantly decreased in both the 12 and 24 hr fasted rats compared with those fed ad lib. The sixty minute free access to food after 12 or 24 hours of fasting fully reversed these changes. The short-term food intake significantly increased the RNA content of the LHA cells of the 12 and 24 hr fasted animals while the total RNA content of the VMH neurons significantly decreased only in the 24 hr fasted rats. The effect of glucose and glycerol administration on the RNA content of the LHA neurons (in 12 hr fasted rats) was similar to the effect of refeeding. One hour after giving glucose (1 g/kg b.wt.) or glycerol (300 mg/kg b.wt.) the total RNA content in the LHA neurons significantly increased. No changes in RNA content were observed in the neurons of the cortex when comparing the experimental and control rats. The results demonstrated the close relationship between the RNA content of the hypothalamic neurons and the feeding status.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain cell RNA: sexual differences in the rat.

Sexual differences in the total content of ribosomal RNA, established by cytophotometric measurements in neurones from selected brain regions, were studied in rats of the Wistar strain. In females of reproductive age, cyclic changes of RNA were synchronized with their oestrous cycle, the values being higher in the oestrous phase than in dioestrus. These changes were observed in pyramidal cells of the hippocampus and of the frontal cortex, in cells of anterior thalamus, of ventromedial and lateral hypothalamus and of tuberculi olfactorii. However, cycling cells were not disclosed in septum and thalamus posterior. A dependence upon the actual level of ovarial hormones was found in ventromedial hypothalamic cells only. In general, the RNA values in males of the same age corresponded to values of dioestrous females. The differences between newborn and 7-day-old pups were not marked enough and did not allow to define the critical period responsible for initiation of this sexual difference. In senescent rats, this difference persisted. During the stable phase of long-lasting dioestrus, the total RNA content in cells of the frontal cortex, hippocampus and hypothalamus was higher in females than in males of the same age which may suggest a faster reduction of this substance in aged males. The prolonged influence of oestrogens in the oestrous phase of the climacteric period (preceding the permanent dioestrus) decreased the RNA values in hippocampal and hypothalamic neurones even below the level established during the permanent dioestrus (and thus reached male values). On the contrary, in frontal cortical neurones, the female values remained higher in the permanent dioestrus as well as during long-lasting oestrus. A discussion concerns the possible participation of genetic determination and of the actual state of ovarial hormones in the manifestation of sexual differences in brain cells of the rat.

Oestrous cycle in septal rat females.

Bilateral lesions of the dorsal part of the septal area were produced in the brain of female rats of Wistar and Long-Evans stocks. The cytogram of their vaginal smears was evaluated repeatedly from the 30th day after surgery and permanent impairment of their oestrous cycle was found. In comparison with intact control females, oestrous phases were detected more frequently whereas dioestrous phases were observed less frequently. The proportions between the individual periods of the oestrous phase (i.e. pro-oestrus, oestrus and metoestrus) were equal in both septal and intact animals. No difference was found between the rat stocks used. Similarly, the previous life history of the rats which had been housed either in a socially impoverished environment (i.e. single cages) or in large communities (colonies) exerted no influence upon the postoperative impairment of the oestrous cycle.

Maternal behaviour in septal rat females.

Dorsal lesions of the septum influenced the maternal behaviour of Wistar and Long-Evans females, as well as of their hybrids, in a different way. The phenomenon of infanticide appeared in Wistar females only, whereas mothering was not impaired in others. However, the mouse-killing activity was not enhanced in Wistar females displaying infanticide. On the contrary, they exhibited xenoparental behaviour. If these females had grown up in a species-typical environment, characterized by enriched social stimulation during their critical developmental period, no impairment of maternal behaviour following dorsal septal lesions occurred. The ablation of the whole septum caused a break-down of maternal behaviour with the appearance of infanticide in all females regardless of their stock origin and their individual life history. The specific role of the septum in the control of maternal behaviour is discussed.

Milk fat concentration and growth of rat pups.

The relationship between milk fat concentration and the growth of rat pups from birth to the 20th day was investigated. A total of 36 first-time-lactating Wistar rats and 366 pups from litters of 8-12 were used. The concentration of milk fat was determined by the crematocrit method, on the 2nd, 5th, 10th, 15th, 20th and 25th day of lactation. A wide range of milk fat concentration with a great variability in each individual dam was observed during lactation. To correlate milk fat and pup's growth, the mean value of the milk fat of the individual mothers was calculated for the first 10 days from the values of the 2nd, 5th and 10th day of lactation, and for the second 10 days from the values of the 10th, 15th and 20th days. The results show that pups fed higher fat milk in the first 10 days of life grew faster than pups fed lower fat milk. A significant positive correlation (P < 0.001) was found between the fat concentration of milk and the weight gains of pups in the first 10 days, but not in the older groups. It indicates that the fat concentration of milk is important for the growth of pups mainly in the early postnatal period of life.

Visual evoked potential evidence for magnocellular system deficit in dyslexia.

Some recent studies on dyslexia have suggested a selective abnormality in the magnocellular visual pathway. To verify this hypothesis, we investigated motion-onset visual evoked potentials (VEPs) (predominantly testing the magnocellular system) as well as pattern-reversal VEPs (presumably testing the parvocellular system) in 20 dyslexics and 16 controls (both groups with a mean age of 10.0 years). Although the latencies and amplitudes of the main positive peak of pattern-reversal VEPs did not differ between the dyslexic and control group, the motion specific negative peak of motion-onset VEPs was significantly delayed (p < 0.001) in dyslexics. Our results confirm a selective magnocellular pathway disorder in dyslexics and indicate that the motion-onset VEPs might serve as an objective method for early diagnosis of dyslexia.

Acquisition of avoidance reaction in rats with different social experience in youth.

The acquisition of both active and passive avoidance response, the extinction of the former and the retention of the long-term memory trace of the latter were studied in 30- and 90-day-old male rats of the Wistar strain. The rats were in 3 groups which had had a different history between 15 and 30 days of age: (1) normally weaned rats lived from birth in a cage together with mother and siblings, i.e. under usual laboratory breeding conditions; (2) prematurely weaned rats lived under the same conditions for the first 15 days; after this period, their mother was removed from the cage; (3) community-reared rats had the same history up to 15 days of age; then they began to live in a community (5 connected cages) in contact with both young and adult rats from other cages. Ninety- day-old male rats acquired an active avoidance response at the same rate irrespective of their history in youth but 30-day-old rats were relatively slower if they had been prematurely weaned. Among both normally and prematurely weaned 30-day-old rats, the extinction was slower than in community-reared rats of the same age. Passive avoidance response was acquired by all rats at the same rate irrespective of their history and age. The long- term memory trace was always more stable in adult rats than in young ones.

Role of early experience in social behaviour of laboratory-bred female rats.

Social relationships among female laboratory-bred rats in a community are influenced by their early life history. When the rats were born and kept until adulthood under conventional breeding conditions, i.e. in single cages, and then used to form a community in which they gave birth, one female assumed the dominant role, with all others subordinate. The dominant female herded all young rats born in the community, irrespective of their age, in a single litter and suckled them. She accumulated food and wood shavings from other parts of the community near the nest and prevented access to the nest to all other community members including other females that had given birth. Subordinate females ceased to show maternal behaviour, including lactation, within 24 h (occasionally within 48 h). The mortality of the young until 15 days of age was high. This type of behaviour in a community was observed both with randomly chosen female rats and with rats selected as dominant and subordinate types in preceding experiments. Female rats born and reared in a community and rats living in a community from 15 to 30 days of age did not differentiate into dominant and subordinate types. All females retained their maternal behaviour, including lactation. Mortality of young rats was minimal. In most cases the females built one common nest; sometimes each female built her own nest. The results point to the decisive role of early experience in the development of maternal behaviour and in the occurrence of communal rearing of the young.

Effect of hyper- and hypothyroidism on the alpha-tocopherol concentration in serum and some organs of growing rats.

The finding of a raised alpha-tocopherol concentration in the heart muscle, liver, skeletal muscle and serum during experimental hyperthyroidism, lasting 30 days, made the authors assume that this cumulation is a transient phenomenon which would disappear during a prolonged metabolic disorder as a result of energetic breakdown of the organism. The purpose of the paper was to verify this view. The investigation with experimental hyper- and hypothyroidism was made in 120 rats with a mean weight of 160 g. To 60 animals daily 100 mug thyroxin were administered by the i.p. route, 48 animals were given 2.5 Carbimazol daily by mouth to induce hypothyroidism and 12 animals served as controls. The animals were fed the same diet. The effect of the administered preparations was examined after 20, 30, 40, 50 and 60 days. In hypothyroid animals the 50th day was omitted. The results revealed: 1. In hyperthyroid animals the body weight was almost constant to the end of the experiment. However these animals had a significantly raised weight of the heart muscle and liver, as compared with the remaining two groups. 2. In hyperthyroid animals the highest alpha-tocopherol concentration in the heart muscle and skeletal muscle was recorded after 20 days. During subsequent time intervals the alpha-tocopherol concentration in the heart muscle declined gradually. In the skeletal muscle a dramatic decline occurred after 40 days and proceeded to the end of the investigation when the recorded values were at the borderline of detectability. This finding confirmed the authors view that the alpha-tocopherol cumulation in muscle exposed to an increased work load is a transient phenomenon and disappears during prolonged hyperthyroidism before the breakdown of the organism. 3. In hyperthyroidism no correlation was found between the alpha-tocopherol concentration and the lipid content of organs and skeletal muscle. This correlation was found in hypothyroidism. 4. The alpha-tocopherol serum level in hyperthyroidism was significantly higher than in hypothyroidism. 5. In hyperthyroidism the alpha-tocopherol cumulation in liver increased gradually, and reached its maximum after 50 days. At a time when the alpha-tocopherol concentration in the heart muscle and skeletal muscle declined already, its liver concentration increased. This phenomenon may be associated with the increasing protein synthesis in the liver during hyperthyroidism, or with other phenomena which call for further investigation.

Hypocholesterolemic effect of ascorbic acid in maturity-onset diabetes mellitus.

A significantly lower vitamin C concentration has been found in the blood and particularly in the leukocytes of hypercholesterolemic diabetic patients than of healthy blood donors. Ascorbic acid administered in a dose of 500 mg per day for 12 months to metabolically stabilized hypercholesterolemic subjects with maturity-onset diabetes mellitus (diabetic diet without insulin or diabetic drugs) brought about a striking decline of cholesterolemia and a moderate decline of triglyceridemia. The serum lipid level in the control group given placebo remained unaltered. A daily administration of 500 mg of ascorbic acid for six months failed to affect the fasting level of serum immunoreactive insulin. It is assumed that the long-term administration of ascorbic acid to maturity-onset diabetics removed the tissue ascorbate deficiency and improved the liver ability to compensate the increased endogenous synthesis of cholesterol by its enhanced transformation to bile acids.

[Vitamins C and E in neonates and their mothers]. / Vitamíny C a E u novorozencu a jejich matek.

During the spring months serum levels of vitamin C and E were investigated in 49 women at the end of pregnancy and in their infants at the delivery and on the fifth day after birth. The authors found that 23.3% of the pregnant women (n = 43) who gave birth to mature, normal neonates were not adequately saturated with vitamin C during the spring months. Almost 13% of the infants (12.8%) had lower vitamin C levels on the fifth day after delivery. Two thirds of the mothers (67%) of premature infants (n = 6) had low vitamin C levels. The vitamin E levels in the pregnant women were adequate, 38% of the five-day-old infants had reduced vitamin E levels.

[The effect of natural and artificial nutrition on vitamin C and E levels in the normal infant]. / Vliv prirozené a umelé výzivy na hladiny vitamínu C a E u fyziologických kojencu.

During the spring months the vitamin C and E serum levels were assessed in 44 normal infants. In addition the serum levels of vitamins C and E were assessed in 17 breastfed infants and their mothers. Low vitamin C levels were recorded in five infants (12.2%). Of these four were bottlefed and one infant had a mixed; mostly formula diet. Two infants with a low vitamin C level had fruit juices and strained fruit. All breastfed infants were well saturated with vitamin C despite the reduced vitamin C level of one nursing mother. Low vitamin E levels were found in two infants (4.5%). Both infants were under six weeks and were bottlefed. After supplementation of the diet with nonmilky products the vitamin E levels rose in breastfed as well as bottlefed children. In breastfed infants older than six weeks the vitamin E levels were significantly higher (p less than 0.001), as compared with bottlefed infants. The results of the investigation confirmed that only breastfeeding or well adapted cows milk formula ensure an adequate vitamin C and E level in normal infants.

[Carotenemia]. / Karotenémie.

The authors demonstrate two infants with a yellow skin coloration which developed as a result of excessive dietary carotenoid intake. The yellow coloration, contrary to jaundice, did not affect the sclerae. Elevated blood carotenoid levels were found and a temporary increase of aminotransferases. In both infants lower IgA levels were recorded. After modification of the diet the yellow coloration disappeared and gradually the aminotransferases reached normal levels.