Messungen zur Manipulation der Glucose-abhängigen Tumorsäuerung in vivo

On experimental rat tumors, preferentially on DS-Carcinosarcoma, special glass electrodes were used to measure and to register development of tissue-pH after injection of glucose into the rats.On tumor surface pH-values were lowered more quickly and increased much faster as in tumor depth. The lowest registered pH was about 5,9.High s. c. dosages of Insulin caused a marked decrease of pH-values for nearly one hour too. In metabole effective small tumors tumor acidity could be regulated satisfactory with administered glucose and insulin between pH 7,0 and 6,0.Determination of lactate concentration in tumor tissue, surrounding the electrode, indicated a linear correlation between pH-value und lactate concentration in the range between pH 6,0 and 7,0. Regression coefficient comes to — 40,9 ± 2,2 ×10-3 mMol/g wet weight and pH-unit.It is emphasized that according to the varying cell supply the compact tumor shows no homogeneity on pH-rates, acidification kinetics, and sensibility against acidotic cell lesion.Results are criticized with reference to other publications and their significance for the theory of tumor lesion by alkylating agents is discussed.

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Experimental model for in vivo determination of dietary fibre and its effect on the absorption of nutrients in the small intestine

British Journal Of Nutrition ◽

10.1079/bjn19810105 ◽

1981 ◽

Vol 45 (2) ◽

pp. 283-294 ◽

Cited By ~ 96

Author(s):

Ann-Sofie Sandberg ◽

H. Andersson ◽

B. Hallgren ◽

Kristina Hasselblad ◽

B. Isaksson ◽

...

Keyword(s):

Small Intestine ◽

Wheat Bran ◽

Dietary Fibre ◽

Dry Weight ◽

Direct Analysis ◽

Fresh Weight ◽

Wet Weight ◽

Definition Of

1. An experimental model for the determination of dietary fibre according to the definition of Trowell et al. (1976) is described. Food was subjected to in vivo digestion in ileostomy patients, and the ileostomy contents were collected quantitatively, the polysaccharide components of which were analysed by gas–liquid chromatography and the Klason lignin by gravimetric determination. The model was used for the determination of dietary fibre in AACC (American Association of Cereal Chemists), wheat bran and for studies on the extent of hydrolysis of wheat-bran fibre in the stomach and small intestine. The effect of wheat bran on ileostomy losses of nitrogen, starch and electrolytes was also investigated.2. Nine patients with established ileostomies were studied during two periods while on a constant low-fibre diet. In the second period 16 g AACC wheat bran/d was added to the diet. The ileostomy contents and duplicate portions of the diet were subjected to determinations of wet weight, dry weight, water content, fibre components, starch, N, sodium and potassium.3. The wet weight of ileostomy contents increased by 94 g/24 h and dry weight by 10 g/24 h after consumption of bran. The dietary fibre of AACC bran, determined as the increase in polysaccharides and lignin of ileostomy contents after consumption of bran, was 280 g/kg fresh weight (310 g/kg dry matter). Direct analysis of polysaccharides and lignin in bran gave a value of 306 g/kg fresh weight. Of the added bran hemicellulose and cellulose 80–100% and 75–100% respectively were recovered in ileostomy contents. There was no significant difference between the two periods in amount of N, starch and K found in the ileostomy contents. The Na excretion increased during the ‘bran’ period and correlated well with the wet weight of ileostomy contents.4. In conclusion, it seems probable that determination of dietary fibre by in vivo digestion in ileostomy patients comes very close to the theoretical definition of dietary fibre, as the influence of bacteria in the ileum seems small. Bacterial growth should be avoided by using a technique involving the change of ileostomy bags every 2 h and immediate deep-freezing of the ileostomy contents. True dietary fibre can be determined by direct analysis of polysaccharides and lignin in the food, at least in bran. Very little digestion of hemicellulose and cellulose from bran occurs in the stomach and small bowel. The 10–20% loss in some patients may be due to digestion by the gastric juice or to bacterial fermentation in the ileum, or both. The extra amount of faecal N after consumption of bran, reported by others, is probably produced in the large bowel.

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Significance of pH-value for meat quality of broilers: Influence of breed lines

Veterinarski glasnik ◽

10.2298/vetgl1302067r ◽

2013 ◽

Vol 67 (1-2) ◽

pp. 67-73 ◽

Cited By ~ 6

Author(s):

M. Ristic ◽

K. Damme

Keyword(s):

Meat Quality ◽

Ph Value ◽

Storage Period ◽

Breeding Line ◽

Breast Meat ◽

Ph Values ◽

And Gender

For determination of poultry quality shortly after slaughtering, physical criteria (pH-value, conductivity, colour, juice retention) are of importance. However, they are affected by breeding, transport, cooling and the storage period. PH-values of breast meat (genetically structured material) were recorded shortly after slaughtering (15 min p.m.) and differences between breeding line and gender were found (n=5109). The pH1-values ranged from 5.50 to 6.79. Male broilers showed significantly lower pH1-values than female ones (6.02:6.10). There were also significant differences concerning breeding line and gender. Meat quality (PSE, DFD) of broilers can be recorded quickly and accurately determining the pH1-value of breast meat. Threshold ranges to be considered are ? 5.8 (PSE), 5.9-6.2 (standard meat properties) and ? 6.3 (DFD). This classification is not to be compared to the deviation of pork.

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The pH measurement with glass electrode in an electromagnetic field

Journal of the Serbian Chemical Society ◽

10.2298/jsc160407082v ◽

2016 ◽

Vol 81 (12) ◽

pp. 1407-1414 ◽

Cited By ~ 1

Author(s):

Dragan Veselinovic ◽

Zoran Velikic

Keyword(s):

Electromagnetic Field ◽

Buffer Capacity ◽

Extreme Values ◽

Ph Value ◽

Radiation Power ◽

Glass Electrode ◽

Frequency Interval ◽

Buffer Solutions ◽

Ph Values ◽

Glass Electrodes

Measurements of pH values of buffer solutions (pH 4.0, 7.0 and 10.0) and distilled water have been performed with a glass electrode in electromagnetic field at the frequency interval of 10 MHz to 200 MHz and the output power of dispersed and reflected electromagnetic radiation of 0.01 W to 3 W. In all the cases, there occurred a reduction of pH values, i.e. a "recorded pH value" was obtained. The reduction appears within the applied frequency interval reaching extreme values at specific frequencies. The reduction of the pH values increases with the radiation power and depend of the solution buffer capacity. The effect of electromagnetic field on pH value change is exerted dominantly through the influence on glass electrodes.

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Growth-related changes of phosphorus metabolites in VX-2 carcinoma implanted into rabbit thigh muscle: in vivo 31P MR spectroscopy

Indian Journal of Animal Research ◽

10.18805/ijar.v0i0f.3798 ◽

2016 ◽

Author(s):

Hyeong-Kil Kim ◽

Gwang Woo Jeong ◽

Tae-Hoon Kim ◽

Gwang-Won Kim ◽

Jong-Bong Kim

Keyword(s):

Tumor Growth ◽

Intracellular Ph ◽

Tumor Necrosis ◽

Time Course ◽

Ph Value ◽

Thigh Muscle ◽

Ph Values ◽

Concentration Changes ◽

Phosphorus Metabolites

The purpose of this study was to evaluate the usefulness of in vivo 31P magnetic resonance spectroscopy (MRS) for monitoring changes in growth-related phosphate metabolite concentration and intracellular pH value in rabbit thigh muscle implanted with VX-2 carcinoma. The time-course magnetic resonance imaging (MRI) and in vivo 31P MRS were examined weekly in the course of 10 weeks following the onset of a VX-2 carcinoma implantation. The spectra were quantitatively analyzed to obtain vital information on the time course variation of the phosphorus metabolites and intracellular pH value according to the tumor growth. Elevation in the concentrations of phosphormonoesters (PME), inorganic phosphate (Pi), and phosphodiesters (PDE) was observed over the time course of 3-4 weeks after the implantation of VX2 carcinoma, while the rest of the metabolites, PCr and ATP tended to be constant. The concentration changes of PME, Pi, and PDE were positively correlated with the volumes of tumor necrosis. The intracellular pH values decreased with the time course of tumor growth and the volumes of tumor necrosis. In vivo 31P MRS is capable of non-invasive monitoring of intracellular pH values as well as the concentration changes of phosphate metabolites during tumor growth.

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Revisiting the fundamentals of p-nitrophenol analysis for its application in the quantification of lipases activity. A graphical update.

Uniciencia ◽

10.15359/ru.34-2.2 ◽

2020 ◽

Vol 34 (2) ◽

pp. 31-43

Author(s):

Randall Syedd-León ◽

Manuel Sandoval-Barrantes ◽

Humberto Trimiño-Vásquez ◽

Luis Roberto Villegas-Peñaranda ◽

Gerardo Rodríguez-Rodríguez

Keyword(s):

Lipase Activity ◽

Ph Value ◽

Protonated Form ◽

Spectrophotometric Analysis ◽

Spectrophotometric Methods ◽

Ph Values ◽

Reaction Media ◽

Activity Quantification

p-Nitrophenol (pNP) is a widely used compound for analytical determinations of several esterases (EC. 3.1.1.X), including lipases (E.C. 3.1.1.3). Most enzymatic measurements employ pNP derivatives such as esters, which are broken down by enzymatic hydrolysis, releasing pNP that is quantified by its absorbance at 410 nm. Although this type of methods was developed a few decades ago, the spectrophotometric analysis of pNP requires analytical measurements of pH and temperature to achieve reliable determinations. The aim of this paper is to offer a graphical update of how pH and temperature affect the p-nitrophenol absorbance at different wavelengths in lipase emulsified media, due to its relevance for the quantitative determination of lipase activity using spectrophotometric methods. To highlight the importance of each variable involved in this analysis, we dissolved pNP in emulsified media (for lipase activity quantification) at several pH values from 4.00 to 11.00, and measured its absorbance in a range of 270 nm – 500 nm and at several temperatures from 25°C to 50°C. The absorption patterns of pNP under the established conditions were graphed in 3D plots. The constructed 3D plots showed that, regardless of the temperature, below pH 6.00, pNP predominantly absorbs at 317 nm, due to the greater abundance of its protonated form, which is completely predominant at pH 3.50 and below. On the other hand, at pH 10.0 and above, the major absorption occurs at about 401 nm, confirming that the equilibrium is completely shifted to the pNP anionic form. These results also indicate that close to neutral pH value pNP, it displays a temperature dependence effect, increasing absorbance to 410 nm at higher temperatures. Due to many analytical determinations of enzymatic activities, the release of pNP is carried around pH 7.00. It is necessary to consider the determinant role of both pH and temperature over these measurements, how these variables must be strictly controlled, and how the calibration curves and blanks should take the reaction media pH and temperature into account.

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In vitro and in vivo nutrient digestibility in sheep of rations with and without residue from the extraction of tamarind pulp

Semina Ciências Agrárias ◽

10.5433/1679-0359.2015v36n6supl2p4507 ◽

2015 ◽

Vol 36 (6Supl2) ◽

pp. 4507

Author(s):

Luiz Juliano Valério Geron ◽

Fabiana Gomes da Costa ◽

Silvia Cristina de Aguiar ◽

Jocilaine Garcia ◽

Matheus Gonçalves Ribeiro ◽

...

Keyword(s):

Crude Protein ◽

Ammonia Nitrogen ◽

Nutrient Digestibility ◽

Neutral Detergent Fiber ◽

Acid Detergent Fiber ◽

Ruminal Fluid ◽

Ph Values

This study evaluated the digestibility of nutrients by, and parameters associated with, in vitro fermentation using different inocula (sheep ruminal fluid and feces) as well as the in vivo digestibility in sheep that were fed rations with 50% concentrate containing either no (0%) residue from the extraction of tamarind pulp (RETP) or 15% RETP. To determine the in vitro digestibility (IVD) of nutrients, two sheep, weighing 40.38 ± 2.10 kg, were used as inoculum donors. To determine the in vivo digestibility of nutrients, we used four sheep and a 3×2 factorial experimental design, with three methods of digestion of nutrients and two experimental rations (0% and 15% RETP). The variables were subjected to analysis of variance and the variables that showed differences at 5% probability were further analyzed using the Tukey test at 5% significance. The IVD using different inocula did not significantly differ (p>0.05) from the in vivo digestibility in sheep for dry matter (DM), organic matter (OM), and neutral detergent fiber (NDF). The different methods for determining nutrient digestibility did not affect (p>0.05) the digestibility of DM, OM, crude protein (CP), NDF, and acid detergent fiber (ADF) in rations with 0% and 15% RETP. However, the IVD of CP for rations containing 0% and 15% RETP incubated with both inocula was lower (p<0.05) than the CP digestibility in vivo. The in vivo digestibility of ADF for rations containing 0% and 15% RETP was higher (P<0.05) than the IVD using sheep ruminal fluid and feces as inocula. The pH values and concentration of ammonia nitrogen (NH3-N) after in vitro incubation for 24 h and the in vivo assay were not different (p>0.05) for the rations containing 0% and 15% RETP, but the pH and NH3-N of both fermented and rumen contents differed (p<0.05) depending on the inocula used and the in vivo assay. In summary, the digestibility of DM, OM, and NDF can be determined by the in vitro fermentation method using the ruminal fluid or feces of sheep as inocula in rations containing 0% or 15% RETP. However, in vitro fermentation is not a suitable method for the determination of pH and NH3-N concentration.

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The role of pH values in porcine reproductive tracts of male and female individuals

Biotechnology in Animal Husbandry ◽

10.2298/bah0804101s ◽

2008 ◽

Vol 24 (3-4) ◽

pp. 101-108 ◽

Cited By ~ 3

Author(s):

T. Smiljakovic ◽

S. Josipovic ◽

O. Kosovac ◽

N. Delic ◽

S. Aleksic ◽

...

Keyword(s):

Reproductive Tract ◽

Ph Value ◽

Rete Testis ◽

Female Reproductive Tract ◽

Ductus Deferens ◽

Male And Female ◽

Ph Values ◽

Small Peak

For a long time, in practice, and science, has been known that pH values of sperm and vagina are important for successful fertilization. In this investigation this fact was confirmed, and the goal was to investigate the role of pH values through whole reproductive tract of male and female individuals: testis, rete testis, epididymis, ductus deferens, Cowper's gland, vesicula seminalis, prostata, corpus cavernosus, corpus spongiosus, epitel tissue of penis tube, sperm, vagina, uterus, horn of uterus, oviduct, fimbrie ovarica, ovarium, follicular fluid. Measurement was performed in reproductive active males as well as before and after ovulation in females. Porcine reproductive tracts (per 15 female and male individuals) were collected from institute's slaughterhouse, immediately post mortem dissected, homogenised and pH values were measured (according to method Rede&Rahelic (1969)). Ovarium and follicular liquid have the highest pH values (7,4) in females, but a small peak in preovulatory oviduct is also present and corresponded to pH of sperm of reproductive fully active male individuals (pH=app.7,2). After fertilization pH in surrounding of zygot (through depolarisation of its membrane) in oviduct, and zygot which then has external decreased pH value moves to less pH values regions by the same principle, that means to uterus, (pH between 7,2 (horn) and 7,07(cervix)) in postovulatory female reproductive tract, where nidation of blastocyst occurs. This investigation could help to elucidate knowledge about reproductive physiology in vivo, giving importance to role of pH values along reproductive tract of male and female individuals.

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Application of membrane filters in determination of the adsorption of tetracycline hydrochloride on graphene oxide

Pharmacia ◽

10.3897/pharmacia.67.e57242 ◽

2020 ◽

Vol 67 (4) ◽

pp. 339-345

Author(s):

Mirza Dedic ◽

Sanjin Gutic ◽

Armina Gicevic ◽

Ervina Becic ◽

Belma Imamovic ◽

...

Keyword(s):

Graphene Oxide ◽

Adsorption Process ◽

Ph Value ◽

Tetracycline Hydrochloride ◽

Time Intervals ◽

Membrane Filters ◽

Ultrasonic Bath ◽

Ph Values ◽

Unique Approach

This paper shows the use of membrane filters in adsorption of solution of tetracycline hydrochloride on graphene materials. The adsorption process was monitored at different wavelengths, different pH values at certain time intervals. The absorbances of the solutions were measured by UV-Vis spectrophotometry at two wavelengths (275 nm and 356 nm), and three pH values (pH 4, pH 7 and pH 10) every 90 minutes for 6 hours of monitoring, with constant stirring in an ultrasonic bath. The results showed decrease in absorbance at both wavelength and in all three pH values which proved the adsorption of tetracycline hydrochloride on GO and rGO. The largest decrease in absorbance was 98.1%. The most suitable pH value for adsorption was pH 4. This paper used a unique approach to filtration through membrane filters, which in the future could lead to the development of membrane filters based on graphene materials.

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LABORATORY TRIAL OF PROTEIN DETERMINATION IN URINE USING DIFFERENT PH VALUES OF ACETIC ACID AND ACETATE BUFFER METHOD

Indonesian Journal of Medical Laboratory Science and Technology ◽

10.33086/ijmlst.v2i1.1459 ◽

2020 ◽

Vol 2 (1) ◽

pp. 34-41

Author(s):

Dinar Rahayu ◽

Tuti Rustiana

Keyword(s):

Acetic Acid ◽

Clinical Examination ◽

Ph Value ◽

Urine Ph ◽

Protein Determination ◽

Ph Values ◽

Significant Difference ◽

Laboratory Trial ◽

Acidic Urine

Abstract The determination of protein in urine is important in clinical examination along with other parameters in urine. The presence of protein in urine can be interpreted that there is a disorder in kidney. Acid and heat coagulations method is still widely used in many areas to determine protein in urine. In this method, the characteristic of protein that will precipitate in the presence of acid or if exposed to heat is deployed to gain information about the amount of protein. The greater amount of protein, the more prominence is the coagulation. Urine pH also varies according to the condition, classic acidosis will give an acidic urine and the presence of ammonium producing bacteria can cause basic urine. In this research acetic acid method with 6% of CH3COOH and pH value of 2,9 and buffer acetic with pH 4,5 are used to determine the certain amount of protein (+3 value, corresponds with 2-4 mg/dL protein in urine) in varied pH values of urine samples. To compare the results, first in control urine with pH 6,8 the results of both methods is compared and shows no significant different, then the Kruskall-Wallis test is used to compare the results in other pH values to control and the test is shown also there are no significant difference. This shows that either acetic acid at pH 2,9 or acetic buffer at pH 4,5 can be used to determine protein amount in urine.

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A New Approach for the Spectroscopic Detection of Different pH-Values

Materials Science Forum ◽

10.4028/www.scientific.net/msf.879.1606 ◽

2016 ◽

Vol 879 ◽

pp. 1606-1611

Author(s):

Christian Rogge ◽

Steffen Zinn ◽

Sylvio Schneider ◽

Roberto Francini ◽

Paolo Prosposito ◽

...

Keyword(s):

Ph Value ◽

Glass Fibers ◽

Bromothymol Blue ◽

Channel Structure ◽

Phenol Red ◽

Ph Indicator ◽

New Approach ◽

Ph Values ◽

Illumination System

The objective of the present work was the development of a micro-pH meter for the determination of the pH value within bioreactors with a volume of up to 200 μl in total. Two different prototypes of optodes were designed and tested. In a first approach spectroscopic analysis of bromothymol blue in a micro-sized-channel structure was carried out utilizing glass fibers, enabling measurements in sample volumes down to the range of picoliters. In a second approach a different illumination system consisting of a RGB-sensor and a LED light source was used. Phenol red was successfully applied as the pH indicator for this setup.

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