Adaptation of the Nauta Method for Use on Degenerating Fibers in Rat Cortex and Thalamus

Lesions produced in the cerebral cortex of rats were studied by Nauta's method for degeneration. The brains were perfused with physiological NaCl solution, followed by 10% neutral (CaCO₃) formalin. The brains were removed and stored in the formalin for 2 wk to 1 yr. Experimental modifications of the staining method showed that its sensitivity for fine degenerating fibers could he enhanced by the following changes: (a) omitting 0.05% potassium permanganate; (b) replacing the hydroquinone-oxalic acid mixture with 0.1% pyrogallol. Procedure: (1) frozen sections to water; (2) 0.5% phosphomolybdic acid, 45 min; (3) distilled water, 1 min; (4) 0.1% pyrogallol (aq.), 2 min; (5) distilled water, 3 washes of 1 min each; (6) 1.5% silver nitrate (aq.), 30 min; (7) distilled water, 1 min, (8) Laidlaw's ammoniated silver carbonate, 10110 sec; (9) Nauta's reducer, 1-2 min; (10) distilled water, 1 min; (11) 1.0% Na₂S₂O₃, 2 min; (12) distilled water 3 changes, 1 min each; (13) dehydrate, clear, and cover. This method gave equally good results on degenerating axons in both cortex and thalamus.     

黄芪种衣剂对黄芪品质的影响

通过以不同用量（种子干重的2%,4%,6%和8%）的黄芪种衣剂包衣种子为处理组,以ND牌种衣剂（种子干重的8%）包衣和空白种子为双对照组,比较研究在不同种子处理条件下,膜荚黄芪植物中黄芪甲苷含量、总黄酮含量及农药残留量发生变化情况。研究结果表明,黄芪种衣剂包衣处理后,明显增加了黄芪中有效成分黄芪甲苷、总黄酮的含量,且包衣所产生的农药残留可随植物生长完全降解掉,研究结果表明黄芪种衣剂的使用可以提高中药材黄芪的品质。     

Influence of hypercapnia on certain aspects of heat exchanges at room temperature in the rabbit

Heat production as well as heat loss from the surface of the ear and airways during and after hypercapnia induced by one hour inhalation of 10% mixture was studied in conscious rabbits. The arterial CO2 tension increased by about 45 mm Hg and pH fell by about 0.3. These changes were associated with decreasing of heat production while heat loss from the ears and airways increased significantly. Consequently the rectal temperature fell meanly by about 0.9 degrees C. The data show that fall of body temperature in the rabbits exposed on 10% CO2 at room temperature is due both to heat production changes and heat loss changes.     

Analysis of the postnatal growth of the mouse liver by estimating the hepatocyte count, their weight and ploidy

Changes in the total number of hepatocytes, their distribution by the ploidy classes, as well as changes in the protein content of the cells were studied in 0.5-6 month old mice. The data obtained made it possible to estimate quantitatively the contribution of different growth components: increase in cell number, hypertrophy and polyploidization of cells, to the total increase of the liver mass. From 2 weeks to 1 month, the liver mass is increased via polyploidization (by 70%) and hypertrophy (by 30%). From 1 to 2 months, the liver mass increases due to hyperplasia (by 65%) and polyploidization (35%). After 2 months, the liver growth is practically terminated. The calculated equivalent mass of the liver, i. e. derivative of all three growth components, coincides fairly well with the factual changes in the liver mass.     

Long-term changes in wood density and radial growth of Quercus petraea Liebl. in northern France since the middle of the nineteenth century

Long-term changes in sessile oak (Quercus petraea Liebl.) growth and wood density were studied using cores collected from 99 even-aged high forest stands between 56 and 187 years old, located in northeastern and north-central France. Growth and density trends were tested by analysis of variance and covariance. Two models were applied to two samples, sample A and sample B (sample B being a sub-sample with limited cambial age and calendar date ranges). Model 1 showed a significant increase in radial growth: +35%, +87% and +66% in earlywood width, latewood width and ring width, respectively, from 1811 to 1993 for sample A. Consequently, there was a positive trend in latewood ratio (+14%). A slight decrease in wood density was found: -3.3% and -5.4% for earlywood and latewood density, respectively. Despite an increase in latewood percentage, mean ring density showed a -2.0% decrease. Model 1 applied to a biomass indicator (density2ring width) showed a 62% increase from 10.4 to 16.8 kg m^-3 between 1811 and 1993 for sample A. Results for sample B were slightly different: the increase in latewood ratio was not detected. Model 2 showed a change with time in the positive hyperbolic relationship between mean density and ring width. The results are discussed. The decrease in wood density cannot be explained by N atmospheric deposition or by long-term changes in average temperature. Increasing atmospheric CO₂ levels cannot be invoked owing to the present lack of studies. Finally, hypotheses concerning long-term changes in wood anatomical characteristics are proposed.     

Estimation of the functional role of arterial pathways to the buttock circulation during treadmill walking in patients with claudication.

The aim of the study was to estimate the functional contribution of the arterial inflow pathways to the pelvic circulation during walking in patients with stage 2 lower extremity arterial disease. Transcutaneous oxygen pressure (Ptc(O(2))) changes during exercise can be used to estimate the severity of regional blood flow impairment while walking. Seventy patients with stable lower limb claudication were studied using a multivariate linear regression model. The relationship between exercise-induced buttock Ptc(O(2)) changes, the ipsilateral calf Ptc(O(2)) changes, and the arterial diameters of the pelvic arteriographic pathways were analyzed. The ipsilateral hypogastric and lumbar pathway, as well as the ipsilateral calf Ptc(O(2)) changes, were the only variables significantly related to buttock Ptc(O(2)) changes (r = 0.47; P < 0.001). Their normalized respective contribution to the regressive model was 39%, 19%, and 18%. None of the contralateral hypogastric, mesenteric, and sacral pathways or pathways stemming from the external iliac artery showed significant correlation to buttock Ptc(O(2)) changes. The ipsilateral hypogastric and ipsilateral lumbar pathways are the major pathways responsible for the functional buttock blood flow supply during walking. The role of contralateral hypogastric, inferior mesenteric, and median sacral pathways and arteries distal to the internal iliac trunk is negligible in the normal or compensatory blood flow supply. Distal Ptc(O(2)) decrease at exercise aggravates proximal Ptc(O(2)) decrease, possibly through the occurrence of a "steal phenomenon" of distal over proximal circulation during walking.     

滩涂池塘生态系统的光合能量利用及其影响因子

研究了江苏沿海滩涂不同养殖模式下初级生产力特征、能量利用率及其影响因子.结果表明,滩涂养殖水体浮游植物的初级生产力存在垂直分布、日变化和季节的动态变化,这种变化与太阳辐射强度有直接的关系.滩涂养殖水体净初级生产量平均值为(7.58±2.52) gO2/(m2 · d),只占毛产量的55.41%,太阳能转化为鲢、鳙鱼产量的生态效率为0.020%～0.029%,这些指标低于我国高产养殖塘,鱼塘生态系统结构有待进一步优化.浮游植物生物量、透明度、N/P值、Mg2+浓度等因素显著影响水体初级生产力的大小,多元逐步回归表明浮游植物叶绿素含量和到达水体表面的太阳辐射强度是初级生产力的最主要因子,其回归方程为:Pg =0.0785Cha+0.0577 Iλ0+1.346;n=22, FCha>F Iλ0>F0.1,而盐度、Na+、Cl-浓度影响不显著.     

Effects of pneumogastric nerve stimulation and injection of a beta 2 stimulant (terbutaline) on the lipid composition of the alveolar lining fluid and on pulmonary compliance in the rat

The effects of vagal stimulation and of terbutaline injection on lipidic composition of alveolar fluid and pulmonary compliance were studied. Three groups of rats were used: control, after right vagus nerve stimulation, after 0.2 mg terbutaline injection. The lungs of the rats were isolated. We studied pulmonary pressure-volume curves with air and we measured pulmonary compliance. We realised an alveolar lavage to obtain alveolar lipids. We observed: Vagus nerve stimulation and beta 2 agonist significantly increased fatty acids of total lipids respectively by 52.5% and 25.5% and phospholipids, respectively by 43.6% and 25.7%. beta 2 agonist did not change fatty acid composition of total lipids and phospholipids. Right vagus nerve stimulation increased the percentage of palmitic acid in phospholipids and decreased the percentage of saturated fatty acids and of palmitic acid in total lipids. Terbutaline injection induced more significant changes in pressure-volume curves and in pulmonary compliance than right vagus nerve stimulation. Our results suggest that both vagal stimulation and beta 2 agonists increase lipid release in alveolar lining, but only vagal stimulation modifies the composition of these lipids. These modifications could be, at least in part, correlated with the changes observed in the pressure-volume curves.     

Heterogeneity of the changes in cytoplasmic pH upon serum stimulation of quiescent fibroblasts

Addition of mitogens to quiescent cells results in rapid ionic changes in the cytoplasm, including pH. We studied the changes in cytoplasmic pH in single Swiss 3T3 cells upon serum stimulation using fluorescence ratio imaging microscopy. Quiescence was attained using two approaches, serum deprivation of subconfluent cells and confluence. All measurements were made in the presence of bicarbonate and the absence of other organic buffers. We also used BCECF coupled to dextran to avoid several artifacts associated with using BCECF-AM, including leakage and phototoxicity. Analysis of the changes in cytoplasmic pH demonstrated a dramatic heterogeneity in the responses of single cells. There were six basic classes of responses, 1) a fast alkalinization, reaching a maximum pH in approximately 2-5 min; 2) a slow alkalinization, reaching a maximum pH in 10-20 min; 3) a very slow alkalinization, not reaching a plateau pH within the measurement time; 4) no apparent change in pH during the measurement time; 5) an early transient acidification, followed by either a fast or slow alkalinization; and 6) an acidification, followed by alkalinization and then by a decrease to some intermediate pH. Subconfluent cells exhibited greater heterogeneity in response than confluent cells, with no single dominant class of response. The dominant (55%) response for confluent cells was a gradual alkalinization of approximately 0.01 pH units/min. A larger proportion (52%) of subconfluent cells exhibited an early transient acidification compared to confluent cells (7%). A significant proportion of both types of cells (23% subconfluent, 36% confluent) exhibited no change in cytoplasmic pH upon stimulation. In general, the kinetics of changes in cytoplasmic pH were significantly different from the published results with population averaging methods.     

Criteria of individual variations in the reactivity of the respiratory system

Individual variations of the respiratory system reactivity have been studied in experiments on rats. It is shown expedient to estimate reactivity of the respiratory system to hypoxic hypoxia by the pattern of changes in the total oxygen uptake. Animals demonstrating no essential changes in the oxygen uptake in response to hypoxia (11% O2) are referred to individuals with high reactivity of the respiratory system; those responding by a drastic decrease in the oxygen uptake--to animals with low reactivity of the respiratory system. A strong correlation is determined between the respiratory system reactivity and individual resistance of organism to acute hypoxic hypoxia.     

Molecular analysis of HEXA gene in Argentinean patients affected with Tay-Sachs disease: possible common origin of the prevalent c.459+5A>G mutation

Tay-Sachs disease (TSD) is a recessively inherited disorder caused by the deficient activity of hexosaminidase A due to mutations in the HEXA gene. Up to date there is no information regarding the molecular genetics of TSD in Argentinean patients. In the present study we have studied 17 Argentinean families affected by TSD, including 20 patients with the acute infantile form and 3 with the sub-acute form. Overall, we identified 14 different mutations accounting for 100% of the studied alleles. Eight mutations were novel: 5 were single base changes leading to drastic residue changes or truncated proteins, 2 were small deletions and one was an intronic mutation that may cause a splicing defect. Although the spectrum of mutations was highly heterogeneous, a high frequency of the c.459+5G>A mutation, previously described in different populations was found among the studied cohort. Haplotype analysis suggested that in these families the c.459+5G>A mutation might have arisen by a single mutational event.     

The nature of the adhesion of Corynebacterium rathayi to the cuticle of the infective larva of Anguina agrostis

The relationship between Corynebacterium rathayi and the infective second stage ‘dauer” larva (DL₂) of Anguina agrostis has been studied with particular regard to the nature and extent of bacterial adhesion to the nematode. Viability of the 1-year-old DL₂ was high, the number of dead specimens per gall only ranging from 5.1% to 8.3%. The DL₂ were exposed to C. rathayi either from cultures or galls and the numbers with and without adhering bacteria were counted. A total of 22,917 DL₂ from 15 galls were examined, the mean number of DL₂ per gall being 1,528. The mean percentage per gall of DL₂ with bacteria adhering was 42%. However there was much variability (from 0 to 98%). The significance of galls with DL₂ that did not succumb to bacterial adhesion is discussed. The sequence of events associated with the process of bacterial adhesion to the nematode cuticle was examined with the aid of the electron microscope. The process involves fusion of the glycocalyx with the bacterial capsule followed by thickening and, at times, displacement of the epicuticle together with changes in the main body of the cuticle. The possible nature of the process of adhesion is discussed.     

Laboratory Hints from the Literature: A Department Devoted To Abstracts Of Books and Papers From Other Joubnals Dealing With Stains and Microscopic Technic In General

Lesions produced in the cerebral cortex of rats were studied by Nauta's method for degeneration. The brains were perfused with physiological NaCl solution, followed by 10% neutral (CaCO₃) formalin. The brains were removed and stored in the formalin for 2 wk to 1 yr. Experimental modifications of the staining method showed that its sensitivity for fine degenerating fibers could he enhanced by the following changes: (a) omitting 0.05% potassium permanganate; (b) replacing the hydroquinone-oxalic acid mixture with 0.1% pyrogallol. Procedure: (1) frozen sections to water; (2) 0.5% phosphomolybdic acid, 45 min; (3) distilled water, 1 min; (4) 0.1% pyrogallol (aq.), 2 min; (5) distilled water, 3 washes of 1 min each; (6) 1.5% silver nitrate (aq.), 30 min; (7) distilled water, 1 min, (8) Laidlaw's ammoniated silver carbonate, 10110 sec; (9) Nauta's reducer, 1-2 min; (10) distilled water, 1 min; (11) 1.0% Na₂S₂O₃, 2 min; (12) distilled water 3 changes, 1 min each; (13) dehydrate, clear, and cover. This method gave equally good results on degenerating axons in both cortex and thalamus.     

Synaptic plasticity and humoral modulation of neuromuscular transmission in the lobster claw opener during the molt cycle

1. Neuromuscular properties of the lobster dactyl opener were studied at different stages of the molt cycle.2. Excitatory junctional potentials (EJPs) were found to be significantly larger in hard-shelled premolt lobsters than in soft-shelled postmolt animals.3. Inhibitory junctional potentials (IJPs) were larger in postmolt claw preparations than in premolt ones.4. Excitatory transmission was also monitored during superfusion with plasma samples obtained from lobsters in vartious stages of the molt cycle (postmolt = AB; intennolt = C; premolt = D₂).5. D₂ plasma increased EJP amplitude by an average of 28% relative to baseline levels (in saline), while AB plasma reduced EJP size by an average of 6%.6. Premolt and postmolt plasma produced opposite effects on quantal content (m); D₂; plasma increased m by a mean of 39%, whereas AB plasma caused a mean reduction by 10%, which suggests that humoral factors may act presynaptically to alter transmitter release.7. These results provide evidence of neuromuscular plasticity in the opener muscle during the molt cycle, and are consistent with changes in claw-opening behavior seen during this cycle.     

Adiponectin and the mediation of HDL-cholesterol change with improved lifestyle: the Look AHEAD Study

Adipose tissue dysfunction plays a key role in the development of the metabolic abnormalities characteristic of type 2 diabetes (T2DM) and participates actively in lipid metabolism. Adiponectin, found abundantly in circulation and a marker of adipose health, is decreased in obese persons with T2DM. We investigated whether the changes in adiponectin with an intensive lifestyle intervention (ILI) for weight loss could potentially mediate the increase in low HDL-cholesterol (HDL-C) with ILI. Adiponectin and its fractions were determined using an ELISA with selective protease treatment in 1,397 participants from Look AHEAD, a trial examining whether ILI will reduce cardiovascular events in overweight/obese subjects with T2DM when compared with a control arm, diabetes support and education (DSE). Multivariable regression and mediational analyses were performed for adiponectin and its high-molecular-weight (HMW) and non-HMW fractions. ILI increased baseline HDL-C by 9.7% and adiponectin by 11.9%; changes with DSE were 1.3% and 0.2%, respectively (P < 0.0001). In a model including changes in weight, fitness, triglycerides, and glucose control and that adjusted for demographics and medical history, adiponectin changes remained significantly associated with HDL-C change. Data supported the contribution of changes in both HMW- and non-HMW-adiponectin to the improvement in HDL-C with ILI     

Changes in the incretory structures of the kidneys and the heterogeneity of the medulla under acute water and salt loading in rats

Juxtaglomerular complex (JGA) and kidney medullar interstitial cells (IC) in rats in acute water and salt loadings were studied. The animals were killed 1 and 2 hours later after water 0.9% and 2% natrium chloride per os administration in quantity of 5%-7% per total body weight. Plasma osmolality and plasma renin activity (PRA) was determined. In light microscopy the granulation of the JGA-cells was in accordance with PRA in all the experiment. IC were not altered in water loading. Marked diminishing of lipid granulation of the IC in all zones of papilla at 2% salt loading was observed. In electron microscopy changes in distribution and density of lipid granules of the IC in all zones of the renal papilla were noted. The lesions showed the dystrophic and necrobiotic changes in some IC, especially in central zone of papilla.     

Duration of renal failure as risk factor for conjunctival squamous metaplasia

OBJECTIVE: To assess ocular surface changes in patients with chronic renal failure (CRF), to compare the results with the duration of illness. STUDY DESIGN: Impression cytology from 48 patients with CRF on regular hemodialysis and 16 age- and sex-matched control subjects were studied. Specimens were taken from the temporal bulbar conjunctiva using cellulose acetate filter paper. RESULTS: Among the patients with CRF who were ill for 0-10 years, 25 patients (78.1%) disclosed grade 0-1, and 7 patients (21.9%) disclosed grade 2-3 cytologic changes, whereas in those with the duration of CRF > 10 years, 9 patients (56.2%) had grade 0-1 and 7 patients (43.8%) had grade 2-3 changes. Specimens from the control group revealed 93.8% grade 0-1 and 6.2% grade 2-3 changes (p < 0.05). CONCLUSION: The ocular surfaces of patients with CRF differ significantly from those of normal individuals, and the severity of conjunctival changes is related to the duration of CRF.     

Efficiency of certain miscible oils and chlorpyriphos methyl insecticide against the soft scale insect,Kilifia acuminata Signoret (Homoptera: Coccidae) and their toxicities on rats

Abstract

The toxicity and efficacy of using three miscible oils; cabl-2, citrole and bio-dux and a chemical insecticide (chlorpyrifos-methyl) were studied against a soft scale insect, Kilifia acuminata (Signoret) infesting mango trees. The sub-chronic toxicity of tested chemicals on white albino rats was also studied. Considering the general mean number of K. acuminata stages after 3 months post spraying, chlorpyrifos methyl and capl-2 were the most efficient compounds followed by citrol and bio-dux in descending order. Chlorpyrifos-methyl was the most effective treatment for all months after spraying, the mean reduction percentage being 94.10, 91.63 and 92.00% while it gave the highest toxic effect after three months; 90.27, 87.84 and 89.73% reduction in infestation on pre-adult, adult and gravid female stages, respectively. Results also indicate that the general mean percent reduction in K. acuminata infestation were 82.62, 86.67, 78.87 and 89.28% in treated trees by citrole, cabl-2, bio-dux and chlorpyrifos-methyl, respectively. Citrole, bio-dux, cabl-2 and chlorpyrifos-methyl caused significant increase in WBCs counts, ALT and AST activities of treated rats after 15 and 30 days from treatment comparison with control. Changes occurring in the creatinine concentration showed a significant increase in rats treated with the tested chemicals 30 days from treatment, except in the case of bio-dux oil, while there were no significant changes after 15 days in rats treated with tested oils. On the contrary, tested chemicals caused a significant decrease in RBCs count and hemogobin values after 15 and 30 days form treatment, except in rats treated with bio-dux oil. Hemoglobin content showed no significant changes over the same periods.     

Alterations of contractility and sarcoplasmic reticulum function of rat heart in experimental hypo- and hyperthyroidism

Myocardial contractility and Ca2+-pump function of sarcoplasmic reticulum (SR) were studied on hearts of untreated, thyroidectomized and thyroxine-treated rats. In hypothyroid rats the contractile force, the maximum velocity of tension development and relaxation significantly decreased (by 73.2%, 68.2%; and 67.8%, respectively), while the time to peak tension was prolonged (by 25.9%) as compared with the control group. In hyperthyroidism opposite changes were found. Since the transport of calcium opposite changes were found. Since the transport of calcium by SR plays an important role in controlling contraction and, first of all, relaxation of muscle, function of the sarcoplasmic reticulum was also investigated under the above experimental conditions. In thyroidectomized rats the rate of Ca2+-uptake and Ca2+-activated ATPase activity of SR significantly decreased (by 31.7% and 61.0%, respectively), while Ca2+-binding remained unchanged. After thyroxine treatment both the Ca2+-uptake and binding capacity of SR were even decreased (by 25.6% and 12.9%, respectively), in spite of an increase in Ca2+-activated ATPase activity (by 67.3%). These changes in Ca2+ transport function of cardiac SR may only partially be responsible for the abnormalities in contraction and relaxation observed in hearts from hypo- and hyperthyroid rats.     

Inhibition of phosphatase activity prolongs NMDA-induced modification of the postsynaptic density

NMDA-induced modification of postsynaptic densities (PSDs) was studied by immunoelectron microscopy. Treatment of cultured hippocampal neurons with NMDA for 2 min promotes a 2.3 fold thickening of the PSD and a 4 fold increase in PSD-associated CaMKII immunolabel. These changes are reversed 5 min after the removal of NMDA and Ca²⁺ from the medium. In addition, following NMDA treatment, PSDs exhibit a 7.5 fold increase in labeling with an antibody specific to the (Thr286) phospho-form of CaMKII, indicating that CaMKII translocated to the PSD is phosphorylated. When the phosphatase inhibitors, calyculin A or okadaic acid, are included in the medium, the NMDA-induced thickening of the PSD as well as the increase in PSD-associated CaMKII immunolabeling are largely maintained (75% and 88% of the peak values respectively) at 5 min after removal of NMDA and Ca²⁺ from the medium. These results imply that NMDA receptors can mediate activity-induced changes in the PSD and that phosphatases of type 1 and/or 2A are involved in the reversal of these changes.