The altered expression of MHC-class II determinants on monocytes of cancer patients

Summary The expression of MHC class II determinants Ia.7 (detected by cross reactive mouse anti-Ia^k antibody) and HLA-DR on monocytes (MO) of gastric and colorectal cancer patients was examined. An increased proportion of MO bearing the Ia.7 determinant was found, while the number of MO expressing DR was not elevated. In gastric cancer patients the increased expression of the Ia.7 determinant was most pronounced in advanced cancer (stage IVA and IVB). The increased expression of this determinant was related to the presence of the tumour as the number of MO expressing Ia.7 decreased 6 months following surgical resection of the tumour. Further, the increased expression of Ia.7 on MO correlated with the tumour infiltration of the serosa. The Ia.7 determinants were mainly expressed on MO which also expressed the receptor for the Fc part of immunoglobulin. Immunostaining in cellular infiltrates surrounding the tumour revealed that Ia.7⁺ macrophages (MØ) were more numerous than in normal gastric mucosa and severe chronic gastritis and were mostly present in close proximity to tumour cells, while DR⁺ MØ were mainly localized within the stromal tissue of the tumour and their number was not increased in cancer infiltrates. These observations indicate that the Ia.7⁺ subpopulation of MØ may be involved in the anti-tumour response of the host.     

Hyperiodothyroninaemia of neonates, its significance for thermogenesis

Danowski et al. (1951) were probably the first who showed an increase of PBI in infants shortly after birth. Later a number of investigators presented further evidence on the increased thyroid gland function in newborns. This condition named "neonatal thyroid hyperactivity" [Fisher and Oddie, 1964] was described also in animals. The available data indicate that all the newborn mammals till now studied, independently of the maturation stage of development they reach at birth, display some features of thyroid hyperactivity, but in some it does not lead to hyperiodothyroninaemia. Interspecies differences coincide well with significance of the thyroid hormones for neonatal thermogenesis. There are few sequential studies of the three principal iodothyronines: T4, T3 and rT3 available at present. The most comprehensive data concern infants, newborn lambs and pigs. Immediately after birth, there is a sudden rise in serum thyroid hormone concentrations, with some species differences related to the degree of the increase and to the iodothyronines involved. The course of the postnatal hyperiodothyroninaemia is dependent on the maturation level reached at birth, food intake, and cooling relative to extrauterine environment. At least five main factors contribute to the immediate postnatal hyperiodothyroninaemia: 1) abrupt depletion of the preformed fetal hormonal iodine stores; 2) preferential T3 secretion; 3) increase in the T4 to T3 monodeiodination in the peripheral tissues; 4) a release of thyroid hormone content from peripheral reservoirs to plasma, and 5) action of other hormone(s) concomitantly released at birth. From the point of view of the thermal adaptability, the newborn mammals fall into two distinct groups: first, in which immediately after birth the metabolic rate decreases, and second, in which the metabolic rate increases, after cooling. Our understanding of the role and significance of hormonal factors involved in mechanisms of the postnatal thermogenesis is incomplete. However, some similarities in adaptation to cold in adults and in newborns seem to be relevant. Cold adaptation is accomplished by development of nonshivering thermogenesis (NST) depending on NA. The presence of brown adipose tissue (BAT) is essential for NA thermogenic action. According to the common opinion, based on data from laboratory animals and human baby, non-shivering thermogenesis, but not shivering, predominates in newborns. However, data from domestic animals indicate that shivering thermogenesis may be of comparable or greater thermogenic capacity than NST at birth. Besides, there are some newborns which have little or no BAT and associated NST.(ABSTRACT TRUNCATED AT 400 WORDS)     

Deoxynivalenol and 3-acetyldeoxynivalenol and Fusarium species in winter triticale

Fusarium species infecting heads of Triticale and mycotoxins presence in infected kernels and chaff were studied during two seasons. The most important species observed on infected heads were in 1986F. avenaceum (39%),F. nivale (21%),F. culmorum (20%),F. graminearum (14%), and others (6%). In 1987 after long and snowy winterF. nivale dominated (64%), followed byF. avenaceum (24%),F. culmorum (6%), andF. graminearum (5%). The mycotoxins deoxynivalenol (DON) and 3-acetyl DON were present in all 11 subsamples of kernels from heads infected byF. culmorum and/orF. Graminearum (1.6–16.4 mg and 0.7–2.4mg/kg, respectively). Chaff from the same subsamples contained 9.9–33.2mg/kg of DON and 5.2–16.0mg/kg of 3-AcDON. Kernels with visibleFusarium-damage contained 2.4–31.2 mg/kg of DON and 1.2–6.0 mg/kg of 3-AcDON. Remaining part of kernels without symptoms of visibleFusarium-damage contained only DON in an amount of 0.9–5.9 mg/kg.     

The effect of prostaglandin F2 alpha and its analogues on progesterone, estradiol and androgen production by the cultured bovine luteal cells

The effect of PGF2 alpha and its analogues on progesterone, estradiol and androgen production in cow corpus luteum in vitro was investigated. The cells derived from cow corpora lutea (CL) and collected in the early and middle luteal phases of the oestrus cycle were cultured as monolayers. The inhibitory effect was not apparent during the first 48 hr of culture, but appeared after this time and persisted through the remainder of the culture period. The direct luteolytic influence of PGF2 alpha was observed in the cultured cells and showed that this compound can act independently of the blood supply.     

Changes of enzyme activity in the rat liver at different age in circadian cycle

Most of the biological processes in the living organisms of both animals and man are known to be of rhythmical nature. Variability of enzymatic activity in circadian cycle depends on many factors among other on age, sexual maturity, diet as well as medication. The results obtained in our studies indicate, that the activity changes of acid phosphatase and ATP-ase Mg++ dependent in the liver of all the examined age groups were of 24 hour circadian rythm. As to the acid phosphatase activity the results of this experiments showed that in circadian cycle in all examined age groups there is only one peak of elevated activity. ATP-ase Mg++ dependent showed two activity peaks appearing at the same hour both in 30 and 60 days old animals. It should be noticed that the activities of ATP-ase Mg++ dependent in 100 day old animals were two times higher than in 30 and 60 days old rats.     

Nyctohemeral Rhythms of Gonadal, Thyroid and Pineal Function in the Hyperprolactinemic Male Rat

In young adult male rats bearing a donor anterior pituitary gland grafted for 3 weeks under a kidney capsule, serum prolactin (PRL) concentrations were elevated and exhibited a rhythm with the highest values in the light phase. Serum PRL in control animals did not exhibit a significant rhythm. Eutopic pituitary PRL content, manifesting a biphasic (12-hr) rhythm with crests during the day and night in controls, exhibited a similar pattern in grafted rats though an overall reduction in pituitary PRL content was seen in the grafted animals. Neither the normal biphasic serum testosterone rhythm nor the normal 24-hr rhythm (nocturnal surge) of pineal N-acetyltransferase activity and melatonin content were altered in the hyperprolactinemic rats. Serum thyroxine (T₄) and triiodothyronine (T₃) and their free indices (FT₄ I, FT₃ I) and serum thyrotropin (TSH) were highest during the day in controls and grafted rats and a 12-hr rhythmic component was detected in data for these variables. In the grafted animals, the 12-hr component was reflected in an additional peak at night detectable by testing of means. The overall serum T₄ FT₄ I, and TSH levels were lower in grafted rats though overall T₃ and FT₃I levels did not differ between grafted and controls. T₃ uptake (T₃ U) values were similar between controls and grafted rats, in both cases exhibiting a fall during the night. Changes in serum thyronines could not be explained by changes in serum binding as assessed by the T₃U₃ and thus may represent changes in thyroidal secretion of T₄. The rhythm in serum PRL of grafted rats suggests the presence of rhythmic circulating factor(s) capable of influencing ectopic lactotrophs. The reduced eutopic pituitary PRL content suggests a role for PRL in influencing eutopic lactotrophs in the pituitary-grafted hyperprolactinemic male rat model. Though circulating testosterone and pineal melatonin synthesis were not altered in this model, thyroid function appeared to be so.     

Tricyclic Imipramine Modification of the Circadian Rhythms of Hypothalamic Serotonin, its Precursors and Acid Catabolite in Individually Housed Rats

Circadian rhythms of serotonin (5HT), its precursors tryptophan (TP) and 5-hydroxy-tryptophan (5HTP) and its acid catabolite 5-hydroxy-indoleacetic acid (5HIAA), were determined in the hypothalamus of control rats and rats which had been treated continuously with subcutaneous imipramine (10 mg/kg/day) for 2 weeks.

Rats were individually housed and entrained to LD12:12. Controls showed the 5HT and TP peaks in the light and dark periods respectively, as reported in the literature, but no inverted correlation (antiphase) between SHT and 5HIAA rhythms.

Imipramine significantly modified circadian rhythm characteristics: the 5HT acrophase was advanced, that of TP and 5HIAA was delayed. Imipramine also significantly increased hypothalamic SHT and TP concentrations.     

Selected chromosome counts of the Czechoslovak flora I

Chromosome numbers of the following nine taxa of the Czechoslovak flora are given:Atriplex rosea L.,Cardamine resedifolia L.,Groenlandia densa (L.)Fourr.,Isoëtes lacustris L.,Lysimachia nemorum L.,Parnassia palustris L.,Phelipanche caesia (Rchb.) Soják,Rumex patientia L. subsp.patientia andSymphytum officinale L. s. str. A new chromosome number of 2n=80 is reported forRumex patientia L. subsp.patientia. Chromosome numbers of another five taxa are first reported from Czechoslovakia. Each of the ascertained chromosome counts is discussed with respect to hitherto known reports.