Unit Wet Weight Of Tissue Research Articles

Absolute Quantification of Grapevine Red Blotch Virus in Grapevine Leaf and Petiole Tissues by Proteomics.

Grapevine red blotch is a recently identified viral disease that was first recognized in the Napa Valley of California. Infected plants showed foliar symptoms similar to leafroll, another grapevine viral disease, on vines testing negative for known grapevine leafroll-associated virus. Later, the Grapevine red blotch virus (GRBV) was independently discovered in the US states of California and New York and was demonstrated to be the causal agent of red blotch disease. Due to its wide occurrence in the United States, vector transmission, and impacts on grape industry, this virus has the potential to cause serious economic losses. Despite numerous attempts, it has yet not been possible to isolate or visualize viral particles from GRBV-infected plants, thereby hampering the development of a serological assay that would facilitate GRBV detection in grapevine. In this work, mass spectrometry approaches were applied in order to quantify GRBV in infected plants and identify potential biomarkers for viral infection. We present for the first time the physical detection on the protein level of the two GRBV genes V1 (coat protein) and V2 in grapevine tissue lysates. The GRBV coat protein load in petioles was determined to be in the range of 100–900 million copies per milligram wet weight by using three heavy isotope labeled reference peptides as internal standards. In leaves on the other hand, the V1 copy number per unit wet tissue weight appeared to be about six times lower than in petioles, and about 300 times lower in terms of protein concentration in the extractable protein mass, albeit these estimations could only be made with one reference peptide detectable in leaf extracts. Moreover, we found in leaf and petiole extracts of GRBV-infected plants a consistent upregulation of several enzymes involved in flavonoid biosynthesis by label-free shotgun proteomics, indicating the activation of a defense mechanism against GRBV, a plant response already described for Grapevine leafroll-associated virus infection on the transcriptome level. Finally and importantly, we identified some other microorganisms belonging to the grapevine leaf microbiota, two bacterial species (Novosphingobium sp. Rr 2-17 and Methylobacterium) and one virus, Grapevine rupestris stem pitting-associated virus.

Influence of field-based nutrient enrichment on the photobiology of the giant clam Tridacna maxima

Nutrients were added to 12 microatolls in One Tree Island lagoon every low tide for 13 mo to an initial concentration of 10 mu M (ammonium, N) and 2 mu M (phosphate, P). These concentrations remained above background for 2 to 3 h after addition. The addition of ammonium (N and NI-P but not P alone) significantly increased P, (gross photosynthesis) P,, (net photosynthesis) and R (respiration) per unit wet-tissue weight and cc (photosynthetic efficiency) in Tridacna maxima after 3 mo nutrient enrichment. These responses to small and transient changes in ammonium concentrations suggest that symbiotic clams are not nutrient-replete, and that even subtle changes in nutrients can have a measurable effect on photosynthesis. The same clams did not show significant differences in photosynthetic parameters 6 mo after the beginning of nutrient enrichment, suggesting that their previous responses had either been seasonal or that symbiotic clams such as T. maxima are able to adjust their photophysiology following external changes in nutrient concentrations.

Extinction coefficient of polymerized diaminobenzidine complexed with cobalt as final reaction product of histochemical oxidase reactions.

The extinction coefficient is essential for the conversion of cytophotometric (mean integrated) absorbance values into absolute units of enzyme activity, for instance expressed in terms of moles of substrate converted per unit time and per unit wet weight of tissue. The extinction coefficient of polymerized diaminobenzidine (polyDAB) complexed with cobalt as the final reaction product of oxidase reactions was estimated at 575 nm by comparison of the amounts of final reaction products formed after incubation of serial unfixed cryostat sections of rat kidney to demonstrate D-amino acid oxidase activity with either the tetrazolium salt method or the cerium-DAB-cobalt-hydrogen peroxide method. Both procedures resulted in similar localization patterns of final reaction product in a granular form in epithelial cells of proximal tubules in rat kidney. The granules were peroxisomes. Linear relationships were found for both methods between the specific amounts of final reaction product generated by D-amino acid oxidase activity and incubation time. The cerium salt method gave rise to 7.4 times higher absorbance values of final reaction product generated per unit time and per unit wet weight of tissue than the tetrazolium salt procedure. The extinction coefficient of tetranitro BT-formazan is 19,000 at 557 nm. Therefore, the cytophotometric extinction coefficient of the polyDAB-cobalt complex as final reaction product of oxidase reactions was established to be 140,000.

Importance of the intestine as a site of metformin‐stimulated glucose utilization

1. The intestine has been implicated as a site of increased glucose utilization by the antihyperglycaemic drug, metformin. This study makes a quantitative assessment of this effect. 2. Glucose utilization by the intestine and hind limb region was determined by arterial-venous glucose difference adjusted for blood flow rate in fasted rats receiving a hyperglycaemic hyperinsulinaemic infusion. 3. Intrajejunal administration of metformin, 250 mg kg-1, increased glucose disposal during the infusion procedure, associated with increased glucose utilization in the intestine by 69% and in the hind limb region by 40%. 4. Metformin, 250 mg kg-1, increased glucose disappearance during an intravenous glucose tolerance test. This was accompanied by increased uptake of tritiated 2-deoxy-D-glucose into the intestinal mucosa to a greater extent than into skeletal muscles (per unit wet weight of tissue). 5. The results demonstrate that the intestinal mucosa is a quantitatively important site of increased glucose utilization during the blood glucose-lowering effect of metformin.

Histologic Findings Are Not Correlated with Disaccharidase Activities in Infants with Protracted Diarrhea

SummaryHistologic assessment as well as information about the disaccharidase activity of the small intestinal mucosa can be useful in the management of patients with small intestinal mucosal damage. In an effort to determine whether the degree of small intestinal mucosal damage would be reflected in a corresponding reduction in disaccharidase activity, we compared small intestinal mucosal histology with the results of disaccharidase activity measured in per oral suction small intestinal biopsies obtained from 21 infants with protracted diarrhea. The degree of small intestinal mucosal damage was graded using a subjective score (i.e., 0 to 4+ damage) by a pathologist (P) and by a computer‐assisted digitizing system (to assess villus surface area, VSA, and villus/crypt ratio, V/C) in a blinded fashion. The mean (±SD) age of the infants was 2.5 ± 1.5 months, and the duration of diarrhea was 25.2 ± 11.5 days. There was good correlation between the results obtained from the digitizing system and from the pathologist: VSA versus P, r = 0.695; V/C versus P, r = 0.791; p = 0.0004. All infants demonstrated some degree of small intestinal mucosal damage. The mean (±SD) values for P, VSA, and V/C were 2.2 ± 1.3, 2.9 ± 0.9, and 0.9 ± 0.5, respectively. The mean values for lactase, sucrase, and maltase were 17.1 ± 17.0, 71.1 ± 54.0, and 224.3 ± 233 μmol/min/g protein, respectively. No correlation was observed between the histologic scoring results and lactase, sucrase, or maltase measurements. Expressing the disaccharidase activities per unit wet weight of tissue did not improve the correlations. Log transformation of the data also failed to improve the correlations. We conclude that extrapolation of disaccharidase activity from the results of histologic measurements in infants with protracted diarrhea is not reliable.

Histologic Findings Are Not Correlated with Disaccharidase Activities in Infants with Protracted Diarrhea

Histologic assessment as well as information about the disaccharidase activity of the small intestinal mucosa can be useful in the management of patients with small intestinal mucosal damage. In an effort to determine whether the degree of small intestinal mucosal damage would be reflected in a corresponding reduction in disaccharidase activity, we compared small intestinal mucosal histology with the results of disaccharidase activity measured in per oral suction small intestinal biopsies obtained from 21 infants with protracted diarrhea. The degree of small intestinal mucosal damage was graded using a subjective score (i.e., 0 to 4+ damage) by a pathologist (P) and by a computer-assisted digitizing system (to assess villus surface area, VSA, and villus/crypt ratio, V/C) in a blinded fashion. The mean (+/- SD) age of the infants was 2.5 +/- 1.5 months, and the duration of diarrhea was 25.2 +/- 11.5 days. There was good correlation between the results obtained from the digitizing system and from the pathologist: VSA versus P, r = 0.695; V/C versus P, r = 0.791; p = 0.0004. All infants demonstrated some degree of small intestinal mucosal damage. The mean (+/- SD) values for P, VSA, and V/C were 2.2 +/- 1.3, 2.9 +/- 0.9, and 0.9 +/- 0.5, respectively. The mean values for lactase, sucrase, and maltase were 17.1 +/- 17.0, 71.1 +/- 54.0, and 224.3 +/- 233 mumol/min/g protein, respectively. No correlation was observed between the histologic scoring results and lactase, sucrase, or maltase measurements. Expressing the disaccharidase activities per unit wet weight of tissue did not improve the correlations. Log transformation of the data also failed to improve the correlations.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationships between polyamine, deoxyribonucleic acid and oestrogen receptor binding site concentrations in human breast tumours

Concentrations of polyamines, DNA and oestrogen receptor (ER) binding sites have been estimated in 23 malignant and 2 benign breast tumours. Polyamine and DNA concentrations, expressed per unit wet weight of tissue, were significantly higher in ER-poor (< 10 fmol/mg cytosol protein) than in ER-rich tumours. Spermidine/spermine ratios were similar in ER-poor and ER-rich tumours. There was a relationship between polyamine and DNA levels and when polyamine concentrations were expressed per unit weight of DNA those in ER-poor tumours did not differ from those in ER-rich tumours. Possible reasons for these findings are discussed.

Cyclic AMP changes in guinea pig mammary gland and milk.

Cyclic AMP was measured in guinea pig mammary gland biopsies from midpregnancy through lactation and in daily milk samples throughout lactation. The results indicate that mammary gland cAMP levels rise sharply in late pregnancy to a prepartum peak and then drop abruptly at partus. This is similar to the pattern observed by others in rat and mouse although the guinea pig does not undergo a prepartum progesterone withdrawal. In animals with a 3-wk lactation period, milk cAMP concentration decreases approximately 40% between days 10 and 20, whereas the mammary gland level increases 22% per unit wet tissue weight. Although milk concentrations of lactose and cAMP are weakly correlated, a strong correlation exists between the total collected daily outputs of these two substances. The results suggest that, as lactation proceeds, mammary gland cAMP levels gradually increase, whereas milk cAMP levels decrease. Concurrently, lactose output decreases as lactation proceeds. These observations are consistent with first, a milk secretory route for regulating mammary gland cAMP levels (in addition to synthesis and hydrolysis), and second, an inhibitory action of cAMP on lactose synthesis.

Effect of androgens on protein synthesis and secretion in various regions of the rat epididymis, as analysed by two-dimensional gel electrophoresis

Protein synthesis and secretion has been quantified in three regions of the rat epididymis (initial segment, caput and cauda) by measuring the rate of incorporation of radioactive methionine by tissue pieces in vitro. The effect of androgens on protein synthesis and secretion was assessed by comparing tissue from untreated animals, castrated animals, and castrated animals receiving injections of testosterone propionate. Androgens caused up to a 2-fold increase in protein synthesis per unit wet weight of tissue. Qualitative effects of androgens on the types of proteins synthesized and secreted were assessed by two-dimensional gel electrophoresis. Androgens induced a differential response in the synthesis of secretory proteins in that some secretory proteins were androgen-regulated whereas others were not. Evidence was also obtained that protein synthesis and secretion in the initial segments of the epididymis responded to some local testicular factor in addition to androgen. The rate of decline in the synthesis of androgen-dependent secretory proteins following castration varied according to the protein. Moreover, the rate of decline in synthesis of the same protein varied markedly in different regions of the epididymis.

Uptake, Transport and Distribution of dl-α-Tocopheryl Acetate Compared to D-α-Tocopherol in Rainbow Trout (Salmo gairdneri)

The appearance of radioactivity after the oral administration of 3 µCi d-α-[5-methyl-3H]tocopherol and 10 µCi dl-α-[3′,4′-14C]tocopheryl acetate in plasma, liver, kidney, spleen and heart of rainbow trout showed an exponential increase up to 32 hours, followed by a plateau or slight decline from 32 to 64 hours. Radioactivity in the skeletal muscle increased exponentially up to 8 hours followed by a slower linear increase up to 64 hours. Comparisons of plasma 3H and 14C radioactivity suggested that the uptake of d-α-tocopherol (EOH) was 6 to 18 times greater than dl-α-tocopheryl acetate (EAc) in the first 4 hours and 2 to 3 times greater between 8 and 64 hours. At the plateau, the amount of 3H and 14C radioactivity incorporated per unit wet weight of tissue decreased in the order liver > kidney > plasma > spleen > heart » skeletal muscle. More than 87% of the 3H and 14C radioactivity after 16 hours was found to be free α-tocopherol in both plasma and liver. The radioactively labeled vitamins were bound primarily to plasma low-density lipoprotein (density 1.015 to 1.085). These studies support the hypothesis that the uptake, transport and distribution of EAc after hydrolysis in the gastrointestinal tract of trout follows a pattern similar to that of EOH.vitamin E uptake tissue distribution transport trout

Developmental changes in the activity of lipoprotein lipase (clearing-factor lipase) in rat lung, cardiac muscle, skeletal muscle and brown adipose tissue.

The lipoprotein lipase activity of the lung, skeletal muscle, heart muscle and brown adipose tissue of the rat was studied during the period from late foetal to adult life. The enzyme activity in all four tissues emerged substantially during the first 24th after birth. Subsequently, heart and lung enzyme activity remained relatively constant per unit wet weight of tissue. The enzyme activity present in brown adipose tissue and skeletal muscle was elevated per unit weight of tissue during suckling compared with other periods of life. Delivery of near-term foetuses stimulated the emergence of enzyme activity in all four tissues with the same time course as that evoked by normal delivery. The significance of the presence of the enzyme in the tissues and the activity changes which occurred during development are discussed in relation to possible mechanisms of control.

Some cellular characteristics of the epididymal adipose tissue in lean and obese-hyperglycaemic mice.

1. The nitrogen content, total water content,in vivo125l-albumin space, the number and size of adipocytes per unit wet weight of epididymal fat pad and the plasma volume have been studied in lean and obese mice, and in obese mice on chronic restriction of their food intake. — 2. There were fewer, larger adipocytes per unit wet weight of tissue (in young obese mice) with a proportional decrease in the vascular space and water content, and the same nitrogen content as had epididymal adipose tissue from lean mice. — 3. There was a reduction in the nitrogen content of epididymal adipose tissue from obese mice on a restricted diet. — 4. These findings are discussed in relation to the reduced glucose metabolism and lipolysis that are apparent when metabolic data are expressed per unit wet weight.

Fatty acid biosynthesis in rabbit mammary gland during pregnancy and early lactation.

The pattern of fatty acids synthesized by mammary-gland explants from rabbits during pregnancy and early lactation has been studied. From day 12 to day 18 of pregnancy, long-chain (C(14:0)-C(18:1)) fatty acids were the major products. From day 18 to day 21 of pregnancy there was an increase of up to 12-fold in the rate of fatty acid synthesis per unit wet weight of tissue that was almost exclusively caused by the synthesis of octanoic fatty acid and decanoic fatty acid, which are characteristic of rabbit milk. These medium-chain fatty acids were mainly incorporated into triglycerides. From day 22 to day 27 of pregnancy there was little change in the rate of fatty acid synthesis and the proportions of fatty acids synthesized were essentially the same as those synthesized by the lactating gland, i.e. 80-90% octanoic acid plus decanoic acid. About 2-4 days before parturition a second lipogenic stimulus occurred, although the pattern of fatty acids synthesized did not change.

Genetic Aspects of Adrenal and Hepatic Cortisol 2α- and 6β-Hydroxylation in Guinea Pigs: Developmental Pattern and Effect of Substrate Concentration

Initial rates of cortisol 2α- and 6β-hydroxylation were determined in liver whole homogenates from 2 guinea pig genotypes differing in their ability to hydroxylate cortisol (high and low producers). Under optimal conditions (pH, TPNH and tissue concentration) the subcellular distribution, developmental pattern and effect of substrate concentration have been studied. No significant difference was found between the 2 types in regard to the subcellular distribution of the enzymatic activities, which were primarily concentrated in the microsomal fraction. The developmental pattern of the cortisol 2α- and 6β-hydroxylase specific activities (on a unit wet tissue weight basis) of adrenal and liver homogenates from males and females of the 2 strains was determined at a substrate concentration of 10 μm. In the high producers there was an increase in the adrenal 2α- and 6β- hydroxylase specific activities after birth up to approximately 100 days of age. The much lower adrenal activities in the low producers increased after birth until the age of 60 days, then tended to level off, and after 150 days of age decreased. The activity in the fetal adrenal and liver of both strains was insignificant in comparison to that seen after birth. The hepatic 2α-hydroxylase specific activity of the high producers exhibited a characteristic rise around 7 days of age, while the 6β-hydroxylase exhibited a broader maximum between 7 and 30 days of age. The hepatic specific 6β-hydroxylase activity of the low producers exhibited a maximum between 30 and 60 days of age. The hepatic 2α-hydroxylase activity of the low producers remained insignificant in comparison to that of the high producers from birth to maturity. The high producer males after 60 days of age exhibited a higher slope in the increase of the adrenal specific enzymatic activities with age than did the females. There was no significant sex difference in the hepatic activities of either strain. The adrenal and hepatic 2α-hydroxylase and the adrenal 6β-hydroxylase specific activities of adult high producer males were approximately 10-fold higher than those of the low producers. The hepatic 6β- hydroxylase activity of high producers was only 1.5-fold higher than that of low producers. The adrenal 2α- and 6β-hydroxylase activities of high producers were approximately 100-fold higher than the corresponding hepatic activities. While the adrenal 2α-hydroxylase activity of the low producers was 100-fold higher than the hepatic activity, the corresponding 6β-hydroxylase activity was only 10-fold higher. A study was made of the effect of substrate concentration on the adrenal and hepatic 2α- and 6β-hydroxylase activities in the 2 strains. The results indicated the presence of multiple enzyme systems. Whereas the hepatic 2α-hydroxylase activity of the low producers approached that of the high producers as the cortisol substrate concentration was increased, the differences between the strains in the adrenal 2α- and 6β-hydroxylase activities persisted over a wide range of substrate concentrations. (Endocrinology86: 851, 1970)

Nucleic Acid Synthesis in Normal and Goitrous Rat Thyroid

Thiouracil, 2-thio-6-aminouracil and an iodine-deficient diet produced an enlargement of rat thyroid glands with a subsequent increase in the acid-soluble nucleotides and RNA per unit wet weight of tissue, while DNA content remained constant or decreased slightly. No change was observed in liver. The pattern of RNA nucleotides of both thyroid and liver was comparable in thiouracil- treated and untreated rats. Uridine phosphorylase and uridine kinase were both more than twice as active in thyroid glands from thiouracil-treated rats as compared to normal glands, while no difference in the activities of the 2 enzymes was observed in liver. Both uracil-2-14C and orotic acid-6-14C were incorporated into CMP and UMP of liver and thyroid RNA from treated and untreated animals. Uracil-2-14C incorporation was 3 times greater in thyroid tissue than in liver, but orotic acid-6-14C was only slightly higher in thyroid. Uracil-2-14C and orotic acid- 6-14C incorporation was increased in goitrous thyroid tissue. The incr...

Xanthine oxidase activity in regenerating liver.

The xanthine oxidase activity of mouse regenerating liver has been shown to be elevated during the period of rapid liver growth and proliferation. This increase is evident when the enzyme activity is expressed per unit wet tissue weight, per unit nitrogen, or per cell. The adrenal cortex probably plays only a minor role in implementing this phenomenon. Further augmentation of the xanthine oxidase level of regenerating liver is not induced by the administration of large quantities of the substrate, xanthine, to the animal.