Salinity tolerance in different cultivars of barley (Hordeum vulgare L.)

Seven barley(Hordeum vulgäre L.) cultivars tested varied greatly in their responses to root medium salinity (electrical conductivity of 3, 5, 10, 15 and 20 dS nr^-1)-lant growth was relatively more adversely affected than seed germination. Dry/fresh mass ratio increased at higher salinity levels in all barley cultivars indicating reduced water uptake. Higher K/Na ratio in plant shoots compared to that in the root medium solution indicated selective uptake of K that seems to be among processes involved in tolerance of cultivars to salinity stress.     

Polarity of transport of 2-deoxy-D-glucose and D-glucose by cultured renal epithelia (LLC-PK1).

At least two types of glucose transporter exist in cultured renal epithelial cells, a Na(+)-glucose cotransporter (SGLT), capable of interacting with D-glucose but not 2-deoxy-D-glucose (2dglc) and a facilitated transporter (GLUT) capable of interacting with both D-glucose and 2dglc. In order to examine the polarity of transport in cultured renal epithelia, 2dglc and D-glucose uptakes were measured in confluent cultures of LLC-PK1 cells grown on collagen-coated filters that permitted access of medium to both sides of the monolayer. The rates of basolateral uptake of both 1 mM glucose (Km 3.6 mM) and 1 mM 2dglc (Km 1.5 mM) were greater than apical uptake rates and the (apical-to-basolateral)/(basolateral-to-apical) flux ratio was high for glucose (9.4) and low for 2dglc (0.8), thus, confirming the lack of interaction of 2dglc with the apical SGLT. Specific glucose transport inhibitor studies using phlorizin, phloretin and cytochalasin B confirmed the polarised distribution of SGLT and GLUT in LLC-PK1 cells. Basolateral sugar uptake could be altered by addition of insulin (1 mU/ml) which increased 2dglc uptake by 72% and glucose uptake by 50% and by addition of 20 mM glucose to the medium during cell culture which decreased 2dglc uptake capacity at confluence by 30%. During growth to confluence, 2dglc uptake increased to a maximum, then decreased at the time of confluence, coincident with a rise in uptake capacity for alpha-methyl-D-glucoside, a hexose that interacts only with the apical SGLT. It was concluded that the non-metabolisable sugar 2dglc was a useful, specific probe for GLUT in LLC-PK1 cells and that GLUT was localised at the basolateral membrane after confluence.     

Gender identification of shovelnose sturgeon using ultrasonic and endoscopic imagery and the application of the method to the pallid sturgeon

Monthly sampling of shovelnose sturgeon Scaphirhynchus platorynchus , a biological surrogate for the endangered pallid sturgeon Scaphirhynchus albus , was conducted to develop a multi‐seasonal profile of reproductive stages. Data collected included histological characteristics of gonads from wild caught fish and laboratory and field ultrasonic and endoscopic images. These data were used to compare effectiveness of ultrasonic and endoscopic techniques at identifying gender of adult shovelnose sturgeon at different reproductive stages. The least invasive method ( i.e . ultrasound) was least effective while the most invasive ( i.e . endoscope through an abdominal incision) was the most effective at identifying shovelnose sturgeon gender. In most cases, success rate for identifying males was greater than females, with success at identifying both genders greater in more advanced reproductive stages. Concomitantly, for most months average reproductive stage was more advanced for males than females. April and May were the months with the most advanced reproductive stage, and were the months when ultrasound was most effective. Methods were also applied in the Upper Missouri River to validate their use on pallid sturgeon Scaphirhynchus albus . Ultrasound was successful at identifying pallid sturgeon gender, however, endoscopic examination through the urogenital duct was only successful at identifying pallid sturgeon gender when the urogenital duct was not opaque.     

Neurogenic cholinergic dilation observed in isolated vessels of the skeletal muscles of cats (the caudal femoral artery)

Neuromediated behaviour of feline caudal femoral arteries was studied in vitro. Transmural stimulation of arteries, previously constricted by noradrenaline, caused an up to 58% relaxation of the induced tone. Atropine (10(-5) g/ml) blocked this response by 93%. The removal of endothelium did not affect the magnitude of the response. It is suggested that the caudal femoral artery is an example of a blood vessel which has muscarinic receptors located directly on its smooth muscles.     

Isoforms of myosin and actin in human, monkey and rat myometrium. Comparison of pregnant and non-pregnant uterus proteins

Using several electrophoretic procedures, we have compared the forms of myosin and actin in pregnant and non-pregnant uterus of woman, monkey (Macaca fascicularis) and rat. On non-dissociating gels, native myosin of the three species migrates as a single band, of identical mobility independently of the physiological state. Remigration of this band in dissociating conditions shows that it is constituted of two heavy chains of respectively 201 kDa and 205 kDa; the relative proportions of these two bands are different for the three animal species but do not vary during pregnancy. Using two-dimensional gel electrophoresis, we found that the 17-kDa light chain of purified uterus myosin exists under two isoelectric forms, the more acidic one becoming progressively predominant at the end of pregnancy in the human as in the monkey uterus, while we observed no changes in the rat. In two-dimensional gel electrophoresis, actin of human, monkey and rat uterus is present under three isoforms, the most basic one (the gamma form) increasing early in pregnancy in the two primate species but being always the most abundant form in the rat. The ATPase activity of human uterus myosin was found to be similar for the protein extracted from both pregnant and non-pregnant uterus. The changes observed in the 17-kDa light chain and in the actin isoforms might nevertheless participate in the modifications of contractility of the uterus during pregnancy of the primates.     

Slow Cortical Potentials Preceeding Visually Guided Saccades in Schizophrenics

The parameters of saccades and presaccadic slow potentials were studied in right-handed men with a dominant right eye, including 19 schizophrenics and 12 healthy subjects. For visual stimulation, three light-emitting diodes were used, which were located in the center of the visual field (the central fixation stimulus) and 10° to the right and left of it (peripheral stimuli). Two stimulation protocols were used: with a simultaneous switching off of the central fixation stimulus and switching on of the peripheral stimuli (test 1) and with an interstimulus gap of 200 ms (test 2). According to the latency, saccades were divided into anticipatory, express, and regular. Slow EEG potentials preceding regular saccades were analyzed. It was found that the proportion of anticipatory saccades is considerably higher than the normal value in schizophrenia. The analysis of the presaccadic potentials demonstrated a significant decrease in the amplitude of negative potentials in the vertex region at early stages of presaccadic preparation and its increase in the occipital region at late stages. Test 2 in the patients demonstrated an increase in the positivity focus in the frontal region of the right hemisphere. It was assumed that the alterations found in schizophrenia result from the deficit of frontal cortical fields.     

Quantitative analysis of the temporal pattern of somite formation in the mouse and rat. A simple and accurate method for age determination

The relation between the logarithm of the volume of the embryo and the number of somites was studied in the mouse and rat in the period of about 0-43 somites, a period characterized by a very rapid volume increase. A linear relation was found, and the variability of the individual observations around the straight line was rather small. Using a previously defined age estimate, i.e. the 'developmental age' based on the embryonic volume, we also found a linear relation between this age estimate and the number of somites. With the help of this straight line, the developmental age can be estimated from the number of somites with an accuracy of less than 0.1 day. Therefore, the developmental age can be considered a better age estimate than those based on the usual methods. The time needed to form a new somite was found to be constant in both species during the period studied. The length of the period differed, and was 1.68 h in the mouse and 2.24 h in the rat. However, the volume of the embryo at the time when a specific somite was formed (for instance the 25th) appeared to be the same in both species. Comparison of the volume of embryos, embedded in paraffin and Epon and sectioned, enabled us to estimate the shrinkage in Epon embryos. The volume after processing was approximately 62% of the original volume.     

Cutting edge: a novel mechanism for rescue of B cells from CD95/Fas-mediated apoptosis.

CD95-induced apoptosis contributes to the maintenance of homeostasis in both B and T lymphocyte-mediated immunity. B cells increase CD95 expression in response to activation signals and become susceptible to CD95-induced apoptosis. Protection from CD95-mediated death signals can be induced in mature B cells by signals delivered through the B cell Ag receptor. In this paper we demonstrate for the first time that rescue from apoptosis can occur independently of de novo protein synthesis. This rescue from apoptosis prevents activation of caspase 8, the apical caspase in the CD95 death pathway, and CD95-FADD (Fas-associated death domain containing protein) association does not occur normally. Thus B cell activation signals can biochemically modify proximal elements of the CD95 death pathway and regulate the sensitivity of cells to apoptosis induction at an early stage in programmed cell death.