Monitoring the seeds of chronically irradiated indigenous populations of Plantago lanceolata L. Variability in the progeny

The results of the morphometric study of Plantago lanceolata L. grown, in nursery, from seeds of the first and second post-accident reproductions within the thirty-kilometer zone around the crippled Chernobyl reactor show no relationship between the alterations in some quantitative indices and the variability of gamma-radiation background in places where maternal plants grow.     

A cytogenetic study of the human chorion for the purpose of the prenatal diagnosis of hereditary diseases

Cytogenetical investigation of 50 diagnostic chorionic villus samples from women with a high risk of giving birth to babies with chromosomal and genic pathology, and of 128 chorionic samples obtained from medical abortions, both on the 8-12th weeks of gestation was performed by means of original direct chromosomal analysis. Chromosomal anomalies were found in 6 cases of diagnostic chorion biopsies (12%) and in 4 cases (3%) of medical abortions. The former group included 5 embryos with autosomal trisomy (4--Ts21 and 1--Ts13) and one embryo with monosomy 18. The latter group contained 2 embryos with X-chromosome monosomy and 2 other with chromosomal mosaicism. A significant prevalence of the female sex was found in the diagnostic group (sex ratio 0.56), but not in the medical abortion one (sex ratio 1.0). Analysis of routine chromosomal preparations and those after in situ hybridization with X-chromosome alfoid-probe YAP 1-10 revealed polyploidy in average in 0.8-1% chorion cells. The feasible causes of sex ratio distortion in embryos of diagnostic group and factors responsible for the rate of polyploidy are discussed. High reliability of originally elaborated direct "shaking-blotting" method of chromosomal preparations from chorionic villus samples is stressed.     

Allosteric effects of monoclonal antibodies on human growth hormone

We have previously shown that a monoclonal antibody (MAb) recognizing the human growth hormone (hGH) antigenic domain left exposed after binding to lactogenic receptors enhanced hGH binding probably through allosteric effects on the hormone binding site. Since receptors displaying different specificities would not recognize exactly the same hGH region, we explored whether some of our MAb could affect hGH binding to somatogenic receptors from rabbit liver and to human liver hGH-specific receptors.The effect of MAbAE5, AC8 and F11 on hGH binding was measured by determining the formation of¹²⁵I-MAb:hGH:receptor complexes using two different experimental approaches. Results from procedure A, which involved the previous binding of the hormone to microsomes before adding¹²⁵I-MAb, indicated that the hGH domain defined by epitopes AE5, AC8 and F11 is uncovered in the various hormone:receptor complexes.Procedure B was devised to reveal any alteration in the hGH molecule induced by the MAb. In this case preformed¹²⁵I-MAb:hGH complexes were added to microsomes. Data showed that¹²⁵I-MAb AE5:hGH complexes bound better to the various receptors than¹²⁵I-MAb AE5 to hGH:receptor complexes. On the contrary, hGH previously bound to¹²⁵I-MAb AC8 or¹²⁵I-MAb F11 was less recognized by the receptors than the free hormone. Furthermore, binding of MAb AE5 or MAb F11 to hGH 20 K (a natural hGH variant lacking residues 32–46) also enhanced its affinity to the various receptors whereas MAb AC8 did not inhibit hGH 20 K binding.Results indicated that MAb recognizing the hGH antigenic area that remains unmasked after binding to different membrane-bound receptors are able to affect hormone binding site. MAb would induce either positive or negative allosteric changes in the hormone region involved in its binding to lactogenic, somatogenic and hGH-specific receptors.     

Agave studies in Yucatan,Mexico. II. Nutritional value of the inflorescence peduncle and incipient domestication

Recent ethnobotanical exploration of henequen (Agave fourcroydes) in the Peninsula of Yucatan, Mexico, finds that inflorescence peduncles are used as emergency food and in the preparation of a fermented drink. Bromatological analysis and determination of total carbohydrates were made for the two length classes (ca. 3.30 m and ca. 0.60 m) which are consumed. The analysis of both the cultivated plant and its putative wild ancestor (Agave angustifolia) suggests that utilization of the inflorescence peduncles as food may have been involved in the initial stages of the history of its evolution under artificial selection, because the wild and the cultivated plants have similar palatability. The subsequent agricultural prevalence of annual crop species in the region was possibly responsible for the abandonment of henequen in the local diet. No significant differences are observed between the bromatological and total carbohydrate values of domesticated and wild plants. The preference for small inflorescence peduncles as a vegetable is a consequence of its significantly minor content of raw fiber and its larger content of total carbohydrates. As a fermented drink, longer peduncles are preferred because they provide more substrate material and because fiber can be eliminated by filtering. This agricultural byproduct, almost totally wasted, has potential value as a source of carbohydrates and raw fiber.     

Inhibition of pulsatile luteinizing hormone release by morphine microinjected into mesencephalic dorsal raphe

Blood samples were collected via jugular catheters from ovariectomized rats at 10-minute intervals for one hour before and two hours after microinjection of 0.5 μl of either saline vehicle or morphine sulfate (10 μg) into the dorsal raphe nucleus (DNR) or adjacent peri-aqueductal gray by means of chronically-implanted guide cannulae. LH was measured by radioimmunoassay and mean pre-injec post-injection values were compared for each rat (t test) as well as for each treatment group (paired t test). Neither saline in DRN nor morphine at other sites significantly altered circulating LH. A significant decrease in LH was observed following injection of morphine into DRN. This effect of morphine was prevented by pre treatment of the animals with the narcotic antagonist naltrexone (10 mg/kg i.v.), indicating the involvement of opiate receptors. These results indicate that DRN is one site at which systemically-administered morphine might act, and suggest the possibility of participation of this mechanism in modulation of LH release by endogenous opioids.     

Analysis of long-latency components of field potentials evoked by stimulation of the cerebral cortex and nerves in the cerebellar paramedian lobule

Field potentials evoked in the graunular layer of the cerebellar paramedian lobule of unanesthetized cats in response to stimulation of the sensomotor cortex and limb nerves contained slow negative waves, appearing after a long latent period, which were generated by granule cells. In the case of nerve stimulation this component was recorded both inside and outside the projection zone of the corresponding limb. Cortical stimulation by single stimuli or series of stimuli not more than 1.8–2.5 times above threshold strength led to the appearance of evoked potentials only inside the corresponding projection zone. The long-latency component of field potentials evoked by cerebral stimulation followed high frequencies of repetitive stimulation and was less sensitive to the action of barbital anesthesia than the analogous component of potentials evoked by nerve stimulation. In the case of combined cerebral and nerve stimulation the long-latency components underwent summation. It is concluded that mossy fibers of slowly-conducting spino- and cerebrocerebellar tracts innervate different granule cells in the cerebellar cortex.Institute of Problems in Information Transmission, Academy of Sciences of the USSR, Moscow. M. V. Lomonosov Moscow State University. Translated from Neirofiziologiya, Vol. 14, No. 4, pp. 379–385, July–August, 1982.     

Activation of expression of two immunoglobulin SN-genes in the American mink with Aleutian disease

110 ranch-raised minks were injected with the Aleutian disease virus. Allotypes of constant regions of gamma-heavy chains of the mink immunoglobulins secreted have been analysed during 3 months. Activation of the expression of two markers (H3 and/or H4) up to minor or to nominal level (above 200 micrograms/ml) was observed. No such enhancement of expression of two other allotypes (H6 and H8) was found. The results suggest that the expression of two mink immunoglobulin CH genes induced by viral infection has allotype-specific regulation.     

Changes in the polypeptide patterns of barley seedlings exposed to jasmonic Acid and salinity

Soluble and thylakoid membrane proteins of jasmonic acid (JA)-treated and salt-stressed barley (Hordeum vulgare L.) seedlings were investigated using 15% sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis. High JA concentrations induced marked quantitative and qualitative changes in polypeptide profiles concerning mainly the proteins with approximately equal mobility, as in NaCl-stressed plants. The most obvious increase in thylakoid polypeptide band intensity was at 55 to 57 kilodaltons (kD). The relative share of some polypeptides with apparent molecular masses above 66 kD and of polypeptides with lower molecular masses in the region of 20.5 to 15 kD was enhanced. At the same time, one new band at 31 to 31.5 kD was well expressed at 25 and 250 micromolar JA concentrations and became discernible in the 100 micromolar NaCl-treated plants. The intensity of some polypeptides of soluble proteins (molecular masses of 60, 47, 37, 30, and 23.4 kD) increased with increasing JA concentration, whereas the intensities of other polypeptide bands (55, 21.4, and 15 kD) decreased. Enhanced levels of 60-, 47-, 34-, and 30-kD polypeptides and reduced levels of 55- and 15-kD polypeptides were present in NaCl-treated plants. The appearance of one new polypeptide, of 25.1 kD, was observed only in NaCl-treated plants. At 100 millimolar NaCl, an eightfold increase in proline content was observed while at 250 micromolar JA, the proline content was threefold over the control. It is hypothesized that exogenously applied jasmonates act as stress agents. As such, they provoke alterations in the proline content and they can modulate typical stress responses by induction of stress proteins.     

Mink IgG-allotypes and Aleutian disease

IgG polymorphism (allotypes H3, H4, H6 and H8 of constant region of the gamma-chain) was investigated in healthy and affected with Aleutian disease (AD) minks from two Siberian and one Danish populations. In all three populations, the expression of H3 and H4 allotypes was strongly associated with AD. Among the AD minks the frequency of H6, H8 phenotype was found to be decreased, whereas the frequency of H3, H4, H6, H8 phenotype was significantly increased. At the same time, the populational distribution of the rest phenotypes was similar among healthy and AD minks. The H3, H4, H6, H8 minks showed the highest pathomorphological characteristics of AD. Based on the data concerning mink H3 and H4, and human Gm allotypes, their role as possible genetic markers for hereditary susceptibility to distinct disease is discussed.     

Effect of cAMP on the growth and development of luminescence in Photobacterium belozerskii

The effect of cAMP on the parameters characterizing the development of luminescence in Photobacterium belozerskii is discussed. An addition of cAMP to the culture medium shortened the latent time of luminescence development by 3--6 hours. The intensity of bacterial luminescence increased with a varying rate. During luminescence enhancement the rate of luciferase synthesis increased by a factor of 10 to 10(3). The rate of luciferase synthesis and the maxiumum level of bacterial luminescence when cultivated in the glycerol medium containing arginine and proline increased under the influence of cAMP by 100 and 40 times, respectively. After an addition to cAMP into the glucose medium these parameters of luminescence development increased only when the medium contained arginine. After an addition of cAMP into the glycerol medium the rate of bacterial growth increased two-fold. Possible mechanisms regulating luminescence development and cAMP involvement in these processes are discussed.