Net Grain Research Articles

Expression of messenger ribonucleic acid and presence of immunoreactive proteins for epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha) and EGF/TGF alpha receptors and 125I-EGF binding sites in human fallopian tube.

Reverse transcription polymerase chain reaction (RT-PCR) revealed that the Fallopian tubes express epidermal growth factor (EGF), transforming growth factor (TGF alpha), and EGF receptor (EGF-R) mRNA. The RT-PCR product was verified by restriction enzyme digestion analysis. Immunohistochemically, EGF, TGF alpha, and EGF-R were localized in Fallopian tubes by use of specific antibodies to human EGF, mature fragments of human TGF alpha, and monoclonal antibodies to the extracellular binding domain of EGF-R. The tubal epithelial cells were the primary site of immunoreactive EGF, TGF alpha, and EGF-R, which were present to a lesser extent in the stromal cells, smooth muscle cell layers, fibroblasts of serosal tissue, and arterial endothelial and smooth muscle cells. Using antibodies generated against the amino and carboxy termini of TGF alpha precursor produced a similar cellular distribution to that observed for mature TGF alpha. The intensity of immunoreactive TGF alpha with these antibodies was similar to that seen with EGF. The ciliated and nonciliated epithelial cells in the ampullary and isthmus regions immunostained with similar intensity for EGF, TGF alpha, and EGF-R. The immunostaining for EGF, TGF alpha, and EGF-R was cycle-dependent, was considerably higher during late proliferative and early-to-mid-secretory phases than during early proliferative and late secretory phases of the menstrual cycle, and was reduced during the postmenopausal period. Specimens obtained 5-12 yr after tubal ligation immunostained for EGF, TGF alpha, and EGF-R similarly to sections from unligated tubes taken during the same phase of the cycle. Quantitative autoradiography of 125I-EGF binding generated a pattern similar to that of immunostaining for EGF-R binding. Net grain density/100 microns 2 calculated for different cell types indicated that the epithelial cells had a significantly higher grain density than did other tubal cell types (p < 0.05) without the cycle dependency seen in the immunohistochemical study. In summary, the results demonstrate that the human Fallopian tube expresses mRNA and contains immunoreactive proteins for EGF, TGF alpha, and EGF-R as well as binding sites for 125I-EGF. The cycle dependency and lower immunostaining in postmenopausal tubes suggest a potential regulation of their expression by ovarian steroids. The results imply the importance of EGF/TGF alpha in a variety of tubal biochemical and physiological functions and possibly early embryonic development.

Species Variation in the Genotoxicity of Batracylin

Batracylin (8-aminoisoindolo[1,2-b]quinazolin-1 2(10H)-one), an experimental chemotherapeutic agent, is a heterocyclic aryl amine. The presence of the free amino group suggests that this compound may be a carcinogen. Since many carcinogens or their product interact with DNA, the genotoxicity of batracylin was evaluated. The mutagenicity of batracylin was tested in Salmonella typhimurium (TA 98, TA 100, TA 102) with and without Aroclor-induced rat liver S9. Batracylin induced histidine revertants in all three strains with a higher number of mutants formed in the presence of S9. The maximum mutant incidence as well as the lowest concentration inducing a positive response was observed with TA 98 which detects frameshift mutations. Genotoxicity was further assessed by the induction of DNA repair in hepatocytes isolated from F-344 rats and two mouse strains differing in N-acetyltransferase activity. In hepatocytes from male F-344 rats, batracylin elicited DNA repair at concentrations of 5 × 10 −8 to 10 −6 M. Maximum repair was observed in both strains of mice at 5 × 10 −5 M batracylin, a concentration that was toxic to rat hepatocytes. Cells isolated from the rapid acetylator strain, C57BL/6J, tended to have higher net grain counts than observed with the slow acetylator (A/J) strain, although the differences were not statistically significant. These results demonstrate that batracylin is genotoxic in bacteria and mammalian cells. The species variation in the genotoxicity of batracylin is consistent with in vivo toxicity studies.

Challenges of trade and agricultural development for East/Central Europe and states of the former USSR

ABSTRACTThe agricultural transition in Central and Eastern Europe and the former USSR reflects a fundamental change in development strategy, and will have a profound impact on agricultural trade. The greatest impact will be indirect, through agriculture's contribution to general economic reform and acceleration of regional and global growth. The direct impact on trade in food and fiber will in aggregate consist of a fall in net imports. Most of the decline in net imports will derive from reduction in demand and improved utilization. Potential for productivity increase is substantial, but not all of the increased productivity will be reflected in the traditional supply response of increased production. Instead marginal resources will shift out of farming, and producers will restructure and adopt new technologies in pursuit of lower costs. Shifts in the commodity composition of trade will occur, and the changes in grain and livestock markets will be greatest. If the reform is successful, the former Soviet Union could become a modest net grain exporter instead of a large importer. Wheat would be the leading export grain, and levels of wheat exports and corn imports could become quite sensitive to relative prices on world markets.

Challenges of trade and agricultural development for East/Central Europe and states of the former USSR

The agricultural transition in Central and Eastern Europe and the former USSR reflects a fundamental change in development strategy, and will have a profound impact on agricultural trade. The greatest impact will be indirect, through agriculture's contribution to general economic reform and acceleration of regional and global growth. The direct impact on trade in food and fiber will in aggregate consist of a fall in net imports. Most of the decline in net imports will derive from reduction in demand and improved utilization. Potential for productivity increase is substantial, but not all of the increased productivity will be reflected in the traditional supply response of increased production. Instead marginal resources will shift out of farming, and producers will restructure and adopt new technologies in pursuit of lower costs. Shifts in the commodity composition of trade will occur, and the changes in grain and livestock markets will be greatest. If the reform is successful, the former Soviet Union could become a modest net grain exporter instead of a large importer. Wheat would be the leading export grain, and levels of wheat exports and corn imports could become quite sensitive to relative prices on world markets.

Cellular distribution of epidermal growth factor, transforming growth factor‐α, and epidermal growth factor receptor in fascia and peritoneum during healing in the rat: an autoradiographic and immunohistochemical study

The presence and cellular distribution of epidermal growth factor (EGF), TGF-alpha, and EGF-R were determined in the rat fascial and peritoneal tissue during healing of an incisional injury by means of immunohistochemistry and autoradiographic techniques. The immunostaining intensity for EGF in the regenerating wound area was substantially higher during the first 14 days, then decreased to near prewound levels during 14 to 35 days after surgery. Within the wound area, the most intense immunostaining occurred with inflammatory cells, followed by fascial striated muscle and arterioles, whereas fibroblasts in the regenerating area contained very low immunostaining intensity. The immunostaining pattern for TGF-alpha with the use of three separate polyclonal antibodies that were directed against the amino and carboxy termini of TGF-alpha precursor and a fragment of the mature 50-amino-acid form of TGF-alpha was similar to that seen with EGF and persisted until 28 days after injury. However, fibroblasts in the regenerating area immunostained intensely for TGF-alpha but not for EGF. Quantitative autoradiography of iodine 125-labeled EGF binding and immunohistochemical studies of the EGF-R with monoclonal antibodies that were directed against the extracellular binding domain of EGF-R demonstrated the presence of specific EGF-R in regenerating fascial and peritoneal tissue. Net grain density (100 microm(2)), representing specific binding of (125)I-EGF, was calculated for different cell types in the wound. The grain density over fascial striated muscle, migratory fibroblasts and peritoneal fibroblasts increased by two and one half, three, and four times, respectively, at 7 days and decreased to the values in adjacent unwounded tissue by 21 days after injury (p < 0.05). Immunostaining for the EGF-R generated similar patterns, which persisted for 14 days after injury. The grain density and immunostaining for EGF-R over the arterioles in the wound did not change during the course of healing and was similar to that of the uninjured regions. In summary, these observations indicate that the local levels of EGF, TGF-alpha, and EGF-R increase during the early phases of healing in fascial and peritoneal injury, which suggests a role for these growth factors in the normal mechanism of fascial/peritoneal wound healing and fibrous adhesion formation.

Barley Treated with Ethephon: I. Yield Components and Net Grain Yield

AbstractEthephon [(2‐chloroethyl)phosphonic acid] effectively reduces lodging in barley (Hordeum vulgare L.), but also may have positive or negative influences on grain yield and yield components even if lodging does not occur. The objective of this study was to investigate the effects of ethephon on yield and yield components of barley under western Canadian conditions. In 1987, 1988, and 1989 at Winnipeg MB, ‘Argyle’ conventional height and ‘Samson’ semidwarf barley were grown at 100 and 300 plants m−2 and treated with ethephon at Zadoks growth stage 35 or 45. At harvest, grain yield samples were taken by hand or by combine, and yield components were determined. When lodging occurred, Belgian lodging indices were determined. The two cultivars responded similarly to ethephon application. Hand‐harvested grain yields were either unaffected or reduced by ethephon, but combine‐harvested yield tended to be increased by ethephon in 1989 when lodging was severe in untreated plots. Reductions in hand‐harvested grain yield of ethephon‐treated plots were primarily due to reductions in kernels per spike, which occurred in all 3 yr for barley grown at both plant densities. Ethephon increased spikes per plant for barley grown at both 100 and 300 plants m−2 in 1987, which at the low plant density compensated for reductions in kernels per spike and kernel mass. Barley in ethephon‐treated plots tended to be delayed in maturity compared with untreated plots. This was particularly true in 1987 and 1989, when late tiller emergence was promoted to the greatest extent by ethephon when moisture conditions were favorable. The potential for ethephon to cause yield reductions restricts the use of ethephon in western Canada to situations where the risk of severe lodging is high.

Effect of ethinyl estradiol on endothelial permeability to 125I-labeled albumin in female rats

Endothelial permeability to albumin was studied in the thoracic aorta and cerebral capillaries of oophorectomized rats injected intramuscularly with ethinyl estradiol daily for 10 days. One hour prior to sacrifice, treated animals and their pair-fed controls were each injected intravenously with 1.3 μg of 125I-bovine serum albumin. Its passage into the aortic wall and the cerebral cortex was determined by autoradiography. Net grain counts were obtained separately in the inner and outer zones of the tunica media and in the ventral and dorsal regions of individual segments of the thoracic aorta, excluding branching sites. Separate counts were also obtained in sections of the frontal, right lateral and left lateral areas of the cerebral cortex, excluding the lumen of cerebral blood vessels. In the aorta, the average grain count was found to be significantly increased in estrogen treated rats in all except the ascending segment. This increase was comparable in the ventral and dorsal regions of the aortic wall and its magnitude did not differ significantly in the various segments, indicating a rather generalised effect of the hormone. The average grain count was significantly higher in the brain of treated rats than in the control. The magnitude of this increase was comparable in the three different areas of the cerebral cortex. Such findings point to a change in the blood-brain barrier leading to extravascular leakage of albumin into the adjoining cortical tissue. The present data indicate that synthetic estrogen administration led to enhanced endothelial permeability to albumin in the aorta and in cerebral capillaries. This confirms the results of an earlier study on the permeability of the aortic endothelium to perfused Evans blue-bound albumin in female rats.

Le problème des fourrages en Union Soviétique

The Soviet Feed Grain Problem. The recent Soviet purchase of 2.9 millions metric tons of feed grains from the United States has prompted speculation about the possibilities for continuing and expanding this trade. This paper focuses upon the domestic feed grain situation in the U.S.S.R. and the ongoing party program to improve thep roduction of livestock products and concludes that the problem contains many pitfalls for Soviet leaders, but that progress under this program seems inevitable. While it may be rational for the Soviet Union to import feed grains on a medium-term basis, it will probably remain a net grain exporter in the future. It is certainly premature to conclude that the Soviet Union is changing from its policy of autarky to one of mutual division of labor between East and West. Feed productivity in the Soviet Union has lagged behind demands over the past few years. While attempting to point out the comparative rationality of present measures being taken to solve the crisis in contrast to those of the preceding administration, this paper also attemps to depict some of the chronic weakness in this sector of the Soviet economy and how, in general, the eventual success of the party program does not necessarily justify the means.