Testicular morphometry of rats with Walker 256 tumor supplemented with L-glutamine

Glutamine is often used to treat metabolic changes associated with anorexia-cachexia syndrome in patients with malignant neoplasms. Walker 256 tumor is an excellent model for studying these changes associated with cancer in different organs, including injuries in testicular functions. However, the effects of supplementing glutamine on testicular morphometry in this model have not yet been investigated. Thus, the objective of this study was to evaluate the effect of L-glutamine supplementation on testicular morphometry in rats transplanted with Walker 256 tumor cells. Forty puberty Wistar rats were divided into four groups: control without L-glutamine (C); control supplemented with L-glutamine (CG); inoculated with Walker 256 tumor cells (WT) and inoculated with Walker 256 tumor cells and supplemented with L-glutamine (WTG). The testicles were removed, weighed, fixed in Bouin, and included in paraffin for histomorphometric analysis. Walker 256 tumor caused quantitative changes in the tubular and intertubular compartments and tunica albuginea, with reductions in the percentages of lumen and tunica albuginea, number of Sertoli cells per gram of testis; number of Leydig cells; percentage of blood vessels and connective tissue in intertubule. However, glutamine supplementation prevented part of these changes caused by the tumor, presenting mainly a protective effect on the tunica albuginea and percentage of blood and lymph vessels in the intertubule. These results indicate the potential of L-glutamine was able to recover for testicular dysfunction associated with cancer.     

Effect of vasopressin gene expression on the growth of Walker 256 carcinosarcoma in rats

The growth pattern of the Walker 256 solid tumor has been studied in rats with different doses of the mutant vasopressin gene. In contrast to the vasopressin gene of normal WA rats, that of mutant Brattleboro rats has a deletion in the coding region that blocks expression at the translation level. The mutation is inherited as a recessive character and is expressed in homozygous Brattleboro rats as diabetes insipidus with an increased water consumption because of the absence of vasopressin in the blood. (WAG x Brattleboro) F1 hybrids have the same normal phenotype as WAG rats, including a low water consumption. Walker 256 carcinosarcoma, which is not strain-specific, intensely grows only in WAG and (WAG x Brattleboro) F1 rats. In these groups, the growth of the tumor leads to the animal death within approximately 30 days after the inoculation of tumor cells. In Brattleboro rats, the carcinosarcoma grows less intensely: the tumor node somewhat increases only within the first two weeks, after which the tumor began to decrease and eventually disappears altogether. Both characters exhibit a 100% concordance at the individual level.     

Brain catecholamine alterations accompanying development of anorexia in rats bearing the Walker 256 carcinoma

In the present study, the relationship between central catecholamine levels and the anorexia induced by Walker 256 carcinoma was investigated. Results indicate that the anorexia is not due to depletion of central catecholamines. Tumor bearing rats sacrificed at night, when spontaneous food intake is selectively depressed, showed increased norepinephrine levels in the hypothalamus, cortex and hippocampus and increased dopamine levels in the striatum, midbrain, and cortex. Increased nighttime hypothalamic norepinephrine levels were positively correlated with the magnitude of spontaneous food intake in tumor rats.     

Lifelong exposure to dietary fish oil alters macrophage responses in Walker 256 tumor-bearing rats

Supplementation of the diet with fish oil (FO) decreases growth of the Walker 256 tumor and decreases the cachexia associated with tumor-bearing. The mechanisms by which FO inhibits tumor growth and cachexia are unknown. Macrophages are very important in host defence against tumors since they produce several anti-tumor agents which in turn have been shown to be modified by dietary FO, but rarely in the setting of tumor bearing and never in relation to lifelong exposure. In this study, we compared the effects of supplementation of the diet of pregnant and lactating rats and subsequent supplementation of the offspring with coconut fat or FO on macrophage activities involved in anti-tumor defence. FO supplementation was able to induce an increase in phagocytosis, in O2-, H2O2, nitric oxide, and TNF-alpha production by macrophages and in lysosomal volume in non-tumor-bearing rats. However, phagocytosis, production of O2- and H2O2 and lysosomal volume were not affected by the FO diet when rats were bearing tumors, although nitric oxide production was higher in these animals. It appears that tumor bearing activates the innate immune system and that dietary FO has little effect on innate immunity in the presence of Walker 256 tumors. Thus, it is still unclear how FO decreases the growth of Walker 256 tumors and the associated cachexia.     

Transplantation characteristics of murine neoplasms after long-term frozen storage

Freezing of 34 murine neoplasms for 9 to 12 years in liquid nitrogen showed that (1) all the tumor lines were viable, although the mean survival time (MST) of 16 of these lines was prolonged when the neoplasms were injected directly from the frozen ampule into the appropriate recipients, (2) in most instances, when those lines with prolonged MST when injected from ampule to animal were then injected into a second generation of animals, the MST was similar to or lower than that seen after 1 hr of freezing, (3) and all tumor lines made resistant to chemotherapeutic agents remained resistant to these agents.     

A comparative PET study using different 11C-labelled amino acids in Walker 256 carcinosarcoma-bearing rats

In Walker 256 carcinosarcoma-bearing rats, the dynamic distribution of l-[1-^11C]tyrosine, l-[methyl-¹¹C]methionine, l-[1-¹¹C]methionine and d-[1-¹¹C]methionine has been measured by PET. An equivalent tumor-imaging potential was observed for each of the three l-amino acids. Thirty minutes after injection, the tumors accumulated 57% (P < 0.01) more ¹¹C-activity from l-[1-¹¹C]methionine than from l-[methyl-¹¹C]methionine. At the same point of time, the livers showed a 33% (P < 0.001) higher ¹¹C-uptake with l-[methyl-¹¹C]methionine than with l-[1-¹¹C]methionine. The dynamic tissue data are in agreement with the findings in experiments with ¹⁴C-analogs.     

Time-course changes in potential biomarkers detected using a metabonomic approach in Walker 256 tumor-bearing rats

A metabonomic approach based on complementary hydrophilic interaction chromatography and reversed-phase liquid chromatography combined with tandem mass spectrometry and time-course analysis of metabolites was implemented to find more reliable potential biomarkers in urine of Walker 256 tumor-bearing rats. A major challenge in metabonomics is distinguishing reliable biomarkers that are closely associated with the genesis and progression of diseases from those that are unrelated but altered significantly. In this study, these biomarkers were selected according to the change trends of discriminating metabolites during the genesis and progression of cancer. Seven consecutive batches of urine samples from preinoculation to 16 days after were collected and analyzed. Multivariate analysis revealed 87 discriminating metabolites. Time-course analysis of discriminating metabolites was used to select more reliable biomarkers with regular and reasonable change trends. Finally, 47 were found and 15 were identified including 12 carnitine derivatives, 2 amino acid derivatives, 1 nucleoside. On the basis of time-course behaviors of these potential biomarkers, we hypothesize such disruption might result from elevated cell proliferation, reduced β-oxidation of fatty acids, and poor renal tubular reabsorption. These studies demonstrate that this method can help to find more reliable potential biomarkers and provide valuable biochemical insights into metabolic alterations in tumor-bearing biosystems.     

Survival ofEscherichia coli after storage in various frozen menstrua

The effect of storage at –9 C onEscherichia coli was examined. In buffer or water, survival after three days was less than 40%. Dimethylsulfoxide (DMSO) (10%) and glycerol (10%) were very protective with over 90% survivors. Variability of replicate samples was greater with frozen than with non-frozen suspensions.With a slide culture technique, it was found that the time required for the thawed cells to complete their first division was increased up to a time equivalent to over two divisions, dependent upon the protective storage menstrua.Injury as shown by inability to grow on a minimal medium after thawing was negligible when the cells were frozen in DMSO or glycerol. Cells stored in frozen buffer were sensitive to a 20 min treatment with actinomycin D following thawing but cells frozen in glycerol or DMSO showed little death or injury. The results suggest that an alteration of the cell envelope is initially responsible for death by freezing.This work was supported in part by U.S. Public Health Service Research Grant EF-428 from the Division of Environmental Engineering and Food Protection.     

Sequential chromosome banding and in situ hybridization analysis.

Different combinations of chromosome N- or C-banding with in situ hybridization (ISH) or genomic in situ hybridization (GISH) were sequentially performed on metaphase chromosomes of wheat. A modified N-banding-ISH/GISH sequential procedure gave best results. Similarly, a modified C-banding - ISH/GISH procedure also gave satisfactory results. The variation of the hot acid treatment in the standard chromosome N- or C-banding procedures was the major factor affecting the resolution of the subsequent ISH and GISH. By the sequential chromosome banding - ISH/GISH analysis, multicopy DNA sequences and the breakpoints of wheat-alien translocations were directly allocated to specific chromosomes of wheat. The sequential chromosome banding- ISH/GISH technique should be widely applicable in genome mapping, especially in cytogenetic and molecular mapping of heterochromatic and euchromatic regions of plant and animal chromosomes.     

Sequential G- to R-banding for high resolution chromosome analysis

Summary A sequential staining protocol for revealing first G-and then R-bands on early metaphase chromosomes is presented. Lymphocyte cultures are synchronized with methotrexate, and released from the S-phase block with bromodeoxyuridine. The resulting early metaphase cells are initially G-banded with Wright's stain and then R-banded by the fluorescence plus Giemsa (FPG) technique.