Immunocytochemical Localization of Glutamine Synthetase in Organs of Phaseolus vulgaris L

Glutamine synthetase was localized in nodules, roots, stems, and leaves of red kidney bean (Phaseolus vulgaris L.) by immunocytochemistry. Affinity purified antibodies reactive with glutamine synthetase were prepared using purified nodule-enhanced glutamine synthetase. Immunogold labeling was observed in the cell cytoplasm in each plant organ. In nodules, the labeling was more intense in the infected cells than in the uninfected cells. No labeling was observed in nodule bacteroids, peribacteroid spaces, or in peribacteroid membranes, while previous reports of glutamine synthetase immunolabeling of legume nodules showed labeling in the bacteroid fraction. Significant labeling was observed in nodule proplastids which contained starch granules. Substantial labeling was also observed in leaf chloroplasts. No labeling was observed in other organelles including mitochondria, peroxisomes, and endoplasmic reticulum. Preimmune IgGs did not bind to any structure in the tissues examined.     

Alterations in antioxidant enzyme activities in the eyes, aorta and kidneys of diabetic rats relevant to the onset of oxidative stress

Profound changes in antioxidant enzyme activities were observed in a number of vascular tissues during the development of streptozotocin-induced diabetes in rats. In the eyes, there was an increase in superoxide dismutase activity at week 4 of diabetes. However, no difference in superoxide dismutase activity was observed between the control and diabetic animals at week 8. On the other hand, the diabetic state did not seem to affect the catalase activity in the eyes. There was a generalized increase in catalase activity of the eyes from week 4 to week 8 irrespective of the diabetic state. For glutathione peroxidase in the eyes, a decreased activity was observed in the diabetic animals at week 8, but not in week 4. A different pattern of enzyme activity changes was observed in the aorta where an increase in superoxide dismutase activity was observed in the diabetic group at week 4 but not in week 8. On the other hand, an increase in catalase activity was observed only at week 8 but not at week 4. Whereas there was no observed difference between the control and diabetic animals in glutathione peroxidase activity in the aorta, except for a generalized decrease from week 4 to week 8 in both groups of animals. In big contrast to the eyes and aorta where an increase in superoxide dismutase activity was observed at week 4 of diabetes, no change in kidney superoxide dismutase activity was noted at week 4 and a decrease was observed at week 8. A similar pattern of enzyme activity changes was observed for glutathione peroxidase in the kidneys. The catalase activity in the kidneys was not affected at all by the diabetic state at both week 4 and week 8. These results clearly demonstrate the active involvement of these antioxidant enzymes during the development of diabetes, and could be rationalized by the differential response of the tissues towards the different extent of oxidative stress imposed by the diabetic state on the different tissues.     

Short-term and long-term effects of brown and black masheri (pyrolysed tobacco product) on vitamin A and vitamin C levels in mice and hamsters

The short-term and long-term effects of two most commonly used brown and black masheri were studied in Swiss mice and Syrian golden hamsters. In short-term studies, both the types of masheri extracts (ME) at 3/4 LD50 dose given ip did not have any effect on either liver or plasma vitamin C levels (both species). However, a decrease in liver vitamin A was observed only in hamsters injected with black ME. Similar effect was not observed in mice injected with both the types of masheri extracts. In long-term studies, when both the types of masheri were fed through diet at 10% level for 20 months, no effect was observed on hepatic or plasma vitamin C levels in mice (both sexes), while an increase in vitamin C levels was observed in black masheri diet fed hamsters. A depletion in liver vitamin A was observed in hamsters fed both the types of masheri. Such an effect was observed only in black masheri diet fed Swiss mice (both sexes) and brown masheri diet fed Swiss females.     

EPR spectroscopic analysis of U7 hammerhead ribozyme dynamics during metal ion induced folding

Electron paramagnetic resonance (EPR) spectroscopy was used to examine changes in internal structure and dynamics of the hammerhead ribozyme upon metal ion induced folding, changes in pH, and the presence and absence of ribozyme inhibitors. A nitroxide spin-label was attached to nucleotide U7 of the HH16 catalytic core, and this modified ribozyme was observed to retain catalytic activity. U7 was shown by EPR spectroscopy to be more mobile in the ribozyme-product complex than in either the unfolded ribozyme or the ribozyme-substrate complex. A two-step divalent metal ion dependent folding pathway was observed for the ribozyme-substrate complex with a weak first transition observed at 0.25 mM Mg2+ and a strong second transition observed around 10 mM Mg2+, in agreement with studies using other biophysical and biochemical techniques. Previously, ribozyme activity was observed in the absence of divalent metal ions and the presence of high concentrations of monovalent metal ions, although the activity was less than that observed in the presence of divalent metal ions. Here, we observed similar dynamics for U7 in the presence of 4 M Na+ or Li+, which were distinctively different than that observed in the presence of 10 mM Mg2+, indicating that U7 of the catalytic core forms a different microenvironment under monovalent versus divalent metal ion conditions. Interestingly, the catalytically efficient microenvironment of U7 was similar to that observed in a solution containing 1 M Na+ upon addition of one divalent metal ion per ribozyme. In summary, these results demonstrate that changes in local dynamics, as detected by EPR spectroscopy, can be used to study conformational changes associated with RNA folding and function.     

M. pneumoniae respiratory diseases: clinical features--children

Chest X-ray findings were studied in 618 pediatric patients with M. pneumoniae respiratory infections. Of these, 472 (76 percent) had pneumonia. Pneumonia was most frequently observed in the lower lung field and least frequently in the upper lung field. The enlargement of hilar lymph nodes was observed in 34 percent of patients with M. pneumoniae pneumonia in contrast to 5 to 9 percent of patients with pneumonia due to other agents, suggesting that it was rather characteristic of M. pneumoniae pneumonia. It was observed in no patients below one year of age, in 41 percent of those aged one to five years, and then decreased with increase in age. Of children with M. pneumoniae respiratory infections, fever, pneumonia, and positive CF test were less frequently observed in infants below one year, showing that they have slighter symptoms; positive IHA test was less frequently observed and isolation of M. pneumoniae was more frequently observed, as compared to other age groups, among whom these findings were similar. It must be kept in mind, however, that fatal cases of M. pneumoniae pneumonia in infants were reported.     

Ultrastructural localization of basic proteins in Trypanosoma cruzi.

The postformalin ammoniacal silver (AS) and the ethanolic phosphotungstic acid (EPTA) techniques were applied in epimastigote and trypomastigote forms of the pathogenic protozoa Trypanosoma cruzi to detect basic proteins at the ultrastructural level. With both techniques, reaction was observed in the nucleus and in some cytoplasmic vacuoles. In the kinetoplast of epimastigotes, reaction was observed only at its periphery. In trypomastigotes, however, an intense reaction was observed in the spherical kinetoplast. With the ethanolic phosphotungstic acid technique, reaction was also observed in ribosomes and at the peripheral doublet microtubules of the flagellum. The filaments which form the paraflagellar structure did not react.     

Modeling differences in the vibration response characteristics of the human body

Mathematical models may provide a useful tool for the development and evaluation of seating systems for vibration mitigation. A five-degree-of-freedom (DOF) model was formulated based on the measured driving-point impedance and transmissibilities of major anatomical structures contributing to the observed resonance behaviors. The model was limited in its ability to simulate differences observed in the resonance behaviors of a broader population and was unable to simulate the multiple resonances observed in the thigh. This paper describes the effectiveness of a modified five DOF model in simulating the major resonance behaviors observed in the population using representative data from a 56 kg female and 75 kg male. In addition, the model was also evaluated for its ability to predict the effects of selected seat cushions. The modified lumped-parameter model improved the peak chest and spine transmissibility simulations. The model was effective in simulating both the lower impedance peak observed in the primary resonance region (4-8 Hz) and the prevalent impedance peak observed in the second resonance region (7-10 Hz) in the smaller subjects. However, the model was not effective in predicting the dampening observed in the second resonance peak with the use of cushions. Redistribution of the model coefficients for the legs and the consideration of coupling between the legs and other anatomical structures may further improve the ability of the lumped-parameter model to predict the effects of seating systems on vibration transmission in the human body.     

Ovarian expression of messenger RNA encoding the receptors for luteinizing hormone and follicle-stimulating hormone in a marsupial, the brushtail possum (Trichosurus vulpecula)

Both LH and FSH play a central role in controlling ovarian function in mammals. However, little is known about the type of ovarian cells that are responsive to LH and FSH in marsupials. We determined, using in situ hybridization, the localization of mRNA encoding the receptors (R) for LH and FSH in ovaries of brushtail possums. The mRNA encoding FSH-R was observed in granulosa cells of healthy follicles containing at least two complete layers of cells. The mRNA encoding LH-R was first observed in granulosa cells at the time of antrum formation. Cells of the theca interna expressed LH-R mRNA but not FSH-R mRNA. Neither FSH-R nor LH-R mRNA was detected in atretic follicles. Both FSH-R and LH-R mRNAs were observed in luteal tissue, but only LH-R mRNA was observed in interstitial cells. Granulosa cells from follicles of various sizes (0.5 to >2 mm in diameter) responded to LH and FSH treatment with an increase in cAMP synthesis. In contrast, luteal tissue did not respond to either FSH or LH treatment. In conclusion, expression of FSH-R in the brushtail possum ovary was similar to that observed in many eutherian mammals. However, active LH-R was expressed in granulosa cells much earlier in follicular development than has been previously observed. In addition, although mRNAs for both FSH-R and LH-R were observed, neither FSH nor LH treatment stimulated cAMP synthesis in luteal tissue.     

Diurnal difference in the amount of immunogold-labeled glucomannans detected with field emission scanning electron microscopy at the innermost surface of developing secondary walls of differentiating conifer tracheids

The differences between cell wall formation at night, when the tangential strain used as an index of the volumetric changes in differentiating cells is high, and in the day, when the tangential strain is low, were investigated in Cryptomeria japonica D. Don. Samples containing differentiating xylem were collected at 0500 hours and 1400 hours. The innermost surface of developing secondary walls in differentiating tracheids was observed by field emission scanning electron microscopy. In the specimens collected at 0500 hours, an amorphous material was observed covering the cellulose microfibrils. The cell wall surface was immunogold-labeled with an anti-glucomannan antiserum. After chlorite treatment, the amorphous material disappeared, and immunogold labeling was rarely observed. In the specimens collected at 1400 hours, cellulose microfibrils were clearly evident, and amorphous material and immunogold labeling were rarely observed. We thus confirmed that much amorphous material containing glucomannans is observed at night, when differentiating tracheids are turgid due to the increase in their volume, while the amorphous material was rarely observed during the day when cellulose microfibrils are clearly observed.     

青海高原不同海拔珠芽蓼叶绿体超微结构的比较

 用电子显微镜技术观察研究了生长于青海高原3个海拔地带(2500m、3200m、3980m)的珠芽蓼(polygonum viviparum L．)叶绿体的超微结构,发现随着海拔的升高,叶绿体结构呈现显著的变化趋势。2500m和3200m处叶绿体形状规则,分布在细胞边缘。3980m处叶绿体膨大变形,且分布在整个细胞当中。海拔升高,类囊体膜减少,膜垛叠程度减小。不同海拔珠芽蓼叶绿体的类囊体膜结构差异较大,特点显著。随海拔升高,珠芽蓼叶绿体破坏程度增加。主要表现为类囊体膜肿胀、类囊体膜溶解和叶绿体破裂。许多破裂的叶绿体中残留有发达的基粒和大而多的淀粉粒。珠芽蓼叶绿体的这些结构特征,既是环境胁迫的结果,又是植物适应性的表现。     

Analysis of mutation frequency following continuous and fractionated application of ethyleneimine and ethyl methanesulfonate to male sex cells of Drosophila melanogaster]

The increase in the frequency of recessive lethal sex-linked mutations induced by fractionated effect of ethylene imine (EI) an ethylmethanesulphonate (EMS) on mature sperm of Drosophila melanogaster was observed and compared uith prolonged treatment (8h) and with the additive effect. This effect of dose fractionation was observed in the case of the treatment of sperms in male gonads and in female spermathecas. The increase of the mutation frequency was noted by brood-pattern method after fractionated treatment of spermatocytes and spermatogonia only with EMS. This increase was not observed under the effect of EI on spermatocytes and spermatogonia because of the high sierilization activity of EI. Possible mechanisms of the effects observed are discussed.     

Damage to the erythrocyte membrane caused by chlorophenoxyacetic herbicides

We studied the damage caused to erythrocyte membranes by chlorophenoxyacetic herbicides. An increase in haemolysis was observed. The compounds investigated caused lipid bilayer damage by lipid peroxidation, as well as an increase in membrane fluidity at the 16th carbon atom of fatty acids was observed. Metabolites caused damage to membrane proteins - the free SH group content was increased. Higher toxicity of metabolites compared to basic compounds was observed.     

Adénylate-cyclase/Lipase: Induction des récepteurs hormonaux

An adenylate cyclase activity (AC) was found in guinea pig brown adipose tissue (BAT), since the tissue's apparition. This enzymatic activity increased during the development and showed high values at the end of gestation. An increase of AC units per cell was observed, in addition to the cell multiplication. A norepinephrine stimulation of AC activity was observed at the end of gestation: this regulating action disappeared in the first days of extrauterine life. Neither glucagon nor ACTH had any regulating role upon AC activity during fetal and newborn life. The basal lipolytic activity which was observed in BAT of fetuses (61rst day) and neonate dramatically decreased around the 15th day. A potent lipolysis activation by norepinephrine was observed, but only after birth. The correlation observed between these enzymatic activities in presence of norepinephrine seems to indicate that the AC/lipase system was involved in the neonatal thermogenesis of guinea pigs.     

The "echis carinatus venom" prothrombin assay in coumarin treated patients. A comparison with one-stage and immunological assays.

Prothrombin (factor II) was assayed in a group of coumarin treated patients using the Echis carinatus venom as thromboplastin. The levels obtained were comparable to those observed using the classical one-stage method. A good correlation was in fact observed between the two methods. The levels observed by the Echis carinatus method were definitely lower than those obtained using two immunological methods indicating that Echis carinatus venom activated, in our system, only normal prothrombin. However, even the levels obtained immunologically were slightly decreased, regardless of the method used, as compared to pooled normal plasma. In congenital prothrombin deficiency (homozygotes and heterozygotes) the level obtained by the Echis carinatus method was comparable to that observed by the one-stage method. On the contrary, in a congenital dysprothrombinemia (prothrombin Padua) a normal level was observed whereas the one-stage and two-stage methods yielded constantly levels of about 50% of normal.     

Adiaspiromycosis in a European beaver from Sweden

An infection with the rare mycosis Chrysosporium parvum was diagnosed in a European beaver (Castor fiber) shot in northern Sweden. The animal was in normal body condition and no signs of disease were observed. In the lungs a large number of nodules, up to 5 mm diameter, were observed. A large number of adiaspores were observed in the interstitium of the lungs and in the mediastinal lymph node. A chronic inflammatory reaction dominated by mononuclear leukocytes and giant cells was observed around the spores. This is the first report of adiaspiromycosis (Chrysosporium parvum) in the European beaver.     

Cell-to-cell coupling in early-stage bovine embryos: A preliminary report

Gap junction communication has been implicated in providing positional information within an embryo. This positional information is then used to direct the differentiation of the early embryo. To begin to gain an assessment of the cell-to-cell communication observed in the early bovine embryo, fluorescein (5%) was microinjected into single blastomeres of freshly collected embryos. Dye communication was not observed in any of the 8-to 16-cell stage embryos. Very limited dye coupling was observed in compact morula (18%) and expanded blastocysts (25%). Interestingly, none of the expanded blastocysts resulting from in vitro maturation and in vitro fertilization showed any dye coupling. The degree of coupling observed in the bovine embryo was less than that observed in compact morula mouse embryos, where almost all (95%) embryos showed dye coupling. This experimental data is discussed in context with previous electron microscopy data.     

Effects of fluoride emissions from a modern primary aluminum smelter on a local population of white-tailed deer (Odocoileus virginianus)

The influence of fluoride emissions from a modern aluminum smelter on concentrations of skeletal fluoride and dental fluorosis in a resident population of white-tailed deer was studied. The smelter was located on Mount Holly Plantation in South Carolina, and concentrations of skeletal fluoride in the deer collected at Mount Holly increased approximately five-fold 3 yr after the operation began. Increases in skeletal fluoride of less than two-fold were observed in deer obtained from Medway Plantation which has its nearest boundary 1.6 km from the smelter site. No dental fluorosis was observed in deer collected at Medway Plantation, but mild dental fluorosis was observed in a significant number of deer collected at Mount Holly Plantation. The dental fluorosis that was observed was not associated with incisor wear or with fluoride-induced molar wear. Osteofluorosis of mandibles or metacarpals was not observed in any of the deer obtained from either plantation. The data obtained from this study indicated that the presence of a modern aluminum smelter caused a detectable increase in concentration of skeletal fluoride in the resident population of white-tailed deer, but that no adverse health effects were seen.     

Cytochemical detection of carbohydrates in the Golgi complex of Leptomonas pessoai.

Using the periodic acid-thiosemicarbazide-silver proteinate technique, a positive reaction was observed on the membranes of the Golgi complex of Leptomonas pessoai. A positive reaction was also observed in other cytoplasmic membranes located near the Golgi complex. Structures which could represent reserve polysaccharides were not observed in the cytoplasm of Leptomonas pessoai.     

Acid alpha-glucosidase in Malaysians. Population studies and the occurrence of a new variant.

Acid alpha-glucosidase from the placenta was electrophoretically surveyed in a total of 633 Malaysians, 236 of Malay, 261 of Chinese and 136 of Indian ancestries. A new variant, alpha-glucosidase 3-1 was observed in 1 Malay and 3 Indians. A polymorphism for this enzyme was observed among Indians, but in Chinese and Malays variants are rare. Phenotype 2-1 was observed once in a Chinese and once in a Malay.