scholarly journals Root O 2 consumption, CO 2 production and tissue concentration profiles in chickpea, as influenced by environmental hypoxia

2020 ◽  
Vol 226 (2) ◽  
pp. 373-384 ◽  
Author(s):  
Timothy David Colmer ◽  
Anders Winkel ◽  
Lukasz Kotula ◽  
William Armstrong ◽  
Niels Peter Revsbech ◽  
...  
Keyword(s):  
Tissue Concentration ◽  
Concentration Profiles ◽  
Environmental Hypoxia

Comparative Tissue Concentration Profiles of Fentanyl and Alfentanil in Humans Predicted from Tissue/Blood Partition Data Obtained in Rats

1990 ◽  
Vol 72 (5) ◽  
pp. 865-873 ◽  
Author(s):  
Sven Björkman ◽  
Donald R. Stanski ◽  
Davide Verotta ◽  
Hideyoshi Harashima
Keyword(s):  
Tissue Concentration ◽  
Concentration Profiles

Quantitative Examination of Tissue Concentration Profiles Associated with Microdialysis

1992 ◽  
Vol 58 (3) ◽  
pp. 931-940 ◽  
Author(s):  
Kevin H. Dykstra ◽  
John K. Hsiao ◽  
Paul F. Morrison ◽  
Peter M. Bungay ◽  
Ivan N. MefFord ◽  
...  
Keyword(s):  
Tissue Concentration ◽  
Concentration Profiles ◽  
Quantitative Examination

Bidirectional peritoneal transport of immunoglobulin in rats: tissue concentration profiles

1992 ◽  
Vol 263 (1) ◽  
pp. F15-F23 ◽  
Author(s):  
M. F. Flessner ◽  
R. L. Dedrick ◽  
J. C. Reynolds
Keyword(s):  
Peritoneal Cavity ◽  
Protein Transport ◽  
Tissue Concentration ◽  
Water Flux ◽  
Intraperitoneal Administration ◽  
Capillary Density ◽  
Surrounding Tissue ◽  
Hypertonic Solution ◽  
Heterogeneous Structure ◽  
Concentration Profiles

Protein transport occurs between the blood and the peritoneal cavity during clinical procedures, but events within the surrounding tissue space are poorly understood. We used quantitative autoradiography to examine the tissue concentration profiles of immunoglobulin G (IgG) in regions surrounding the peritoneal cavity. We have varied the route of administration (intravenous or intraperitoneal), the osmolality of the dialysis solution (isotonic or hypertonic), and the time of analysis (20 or 200 min). After intravenous injection, IgG profiles were relatively flat in most tissues and were not affected by time or osmolality. Concentrations corresponded to the capillary density in specific tissues. After intraperitoneal administration, the IgG tissue profiles were significantly steeper than after intravenous administration. The tissue concentrations increased with time but decreased when a hypertonic solution was substituted for an isotonic solution. Hypertonic dialysis causes a water flux into the cavity, which dilutes the contents but does not prevent penetration of protein into the surrounding tissue. Based on IgG movement in tissue during hypertonic dialysis, the peritoneum appears to function as a heterogeneous structure, which allows osmotically induced water transport into the cavity in some regions with simultaneous transport of hydrostatic pressure-driven water and solute flow from the cavity into the tissue in other regions.

A distributed model of peritoneal-plasma transport: tissue concentration gradients

1985 ◽  
Vol 248 (3) ◽  
pp. F425-F435 ◽  
Author(s):  
M. F. Flessner ◽  
J. D. Fenstermacher ◽  
R. L. Dedrick ◽  
R. G. Blasberg
Keyword(s):  
Large Intestine ◽  
Tissue Concentration ◽  
Abdominal Cavity ◽  
Plasma Transport ◽  
Distributed Model ◽  
Concentration Profiles ◽  
Concentration Gradients ◽  
Transport Studies ◽  
Dialysis Solution ◽  
Tissue Fraction

Peritoneal dialysis transport studies were carried out in anesthetized rats. Injections of [14C]EDTA were made by intravenous bolus or intraperitoneal dialysis solution, and blood and peritoneal fluid samples were collected for 1 h. After death and rapid freezing of the animal, transverse sections through the abdominal cavity were cut for quantitative macroautoradiography. The plasma-to-peritoneal transport experiments with a clinical dialysis solution resulted in essentially horizontal concentration profiles versus distance in all tissues except large intestine. Estimates of the extracellular tissue fraction were: small intestine, 0.34; large intestine, 0.28; stomach, 0.30; uterus, 0.66; liver 0.35; diaphragm, 0.16; and anterior abdominal wall, 0.15. Similar experiments with an isotonic salt solution resulted in larger (13-300%) extracellular fractions in all tissues. In contrast, peritoneal-to-plasma transport studies demonstrated decreasing concentration profiles in all visceral tissues, with the first 90% of the gradient contained in the initial 400 micron of tissue from the peritoneum. Parietal tissue gradients were less steep and had higher concentration levels deep within the tissue than visceral tissues. Computer simulations using a distributed model approach compared favorably with the experimental measurements and established the validity of this approach.

Distribution of two model amino acids from cerebrospinal fluid to brain and blood

1982 ◽  
Vol 242 (2) ◽  
pp. F171-F180 ◽  
Author(s):  
J. D. Fenstermacher ◽  
H. Davson
Keyword(s):  
Tissue Distribution ◽  
Diffusion Coefficients ◽  
Tissue Concentration ◽  
Concentration Profiles ◽  
Brain Capillaries ◽  
Brain Capillary ◽  
Distribution Spaces ◽  
Perfusion Period ◽  
And Diffusion ◽  
Serial Brain

Ventriculocisternal perfusions of anesthetized rabbits were performed for 1-3 h with solutions containing radioactively labeled alpha-aminoisobutyric acid (AIB), cycloleucine (CYCL), and sucrose. Serial brain samples were taken at the conclusion of the perfusion period and assayed for radioactivity. Tissue concentration profiles were constructed from these data; tissue distribution spaces and diffusion coefficients (Dt) plus brain capillary transfer constants were estimated from the profiles. The Dt of sucrose was somewhat larger at 1 h than at 2 and 3 h. Tissue distribution spaces of 300-400% were found with AIB after 3 h. Inclusion of 5 mM AIB in the perfusate produced markedly lower tracer AIB spaces. The tissue distribution spaces of CYCL ranged from 100 to 400% and depended on the concentration of CYCL in the perfusate. A brain-to-blood transfer half time of 7.5 min was measured for CYCL. These findings demonstrate that sizable cellular uptake of CYCL and AIB occurs, that these processes are concentration dependent, and that the rates of influx and efflux across brain capillaries are similar.

Fine Structure of Type IV Glycogenosis

1981 ◽  
Vol 39 ◽  
pp. 464-465
Author(s):  
P.K. Simons
Keyword(s):  
Needle Biopsy ◽  
Tissue Concentration ◽  
Inborn Errors ◽  
Rare Type ◽  
Type Iv ◽  
Iron Copper ◽  
Proper Diagnosis ◽  
Type Iv Glycogenosis ◽  
Loss Of Appetite ◽  
Enzymatic Defect

Glycogenosis is defined as any condition in which the tissue concentration of glycogen is increased. There are currently ten recognized variants of glycogenosis that are heritable inborn errors of metabolism. The specific enzymatic defect in each of the variants is known or at least suspected. In all cases, the enzymatic defect prevents the proper metabolism or formation of the glycogen molecule. The clinical and histologic differences between the types of glycogenosis is important to a proper diagnosis after the presence of such a condition is realized. This study was initiated to examine the ultrastructure of the rare Type IV Glycogenosis (Amylopectinosis) of which there is very little morphologic characterization in the literature.Liver tissue was obtained by needle biopsy from a 12-month-old Oriental female who was originally admitted to the hospital after observation of poor development, loss of appetite, and hepatomegaly. The majority of the tissue was fixed for light microscopy in neutral buffered formalin and processed using routine and special staining procedures (reticulin, trichrome, iron, copper, PAS, PAS-diastase and PAS-pectinase.

Absolute SPECT/CT quantification of cerebral uptake of 99mTc-HMPAO for patients with neurocognitive disorders

2016 ◽  
Vol 55 (04) ◽  
pp. 158-165 ◽  
Author(s):  
Friedrich Welz ◽  
James Sanders ◽  
Torsten Kuwert ◽  
Juan Maler ◽  
Johannes Kornhuber ◽  
...  
Keyword(s):  
Tissue Concentration ◽  
Tracer Uptake ◽  
Planar Imaging ◽  
Quantitative Spect ◽  
Dementia Patients ◽  
Hmpao Spect ◽  
Patient Groups ◽  
The Absolute ◽  
99Mtc Hmpao

SummaryIt was reported from planar imaging studies that the cerebral uptake of injected 99mTc-HMPAO activity is about 4–7% in humans. Recent work has shown that modern SPECT/ CT devices are able to quantify the tissue concentration of radioactivity in vivo in absolute units (Bq/ml), while avoiding the limitations of planar techniques. The aims of this study were (a) to determine the cerebral uptake of 99mTc-HMPAO in absolute units in SPECT/CT, (b) to investigate potential differences in absolute tracer uptake for patients suspected of dementia. Patients, methods: We performed 99mTc-HMPAO SPECT/CT in 65 patients with suspected dementia. 99mTc-HMPAO uptake was determined using a previously published quantitative SPECT/CT protocol. The absolute HMPAO uptake and the results of a regionalized analysis were compared for MMSE and NINCDS-ADRDA based patient groups. Results: The mean absolute uptake of 99mTc-HMPAO for our patient population was 4.3 ± 0.8% of the injected dose. The uptake, as well as the regionalized analysis yielded significantly different results for low ( 23) and high (>23) MMSE groups and also for some of the NINCDS-ADRDA groups. Conclusion: Our results show that the absolute cerebral uptake of 99mTc-HMPAO is in the range of previously reported results, obtained by planar techniques. Absolute uptake is significantly different between the patient groups.

Chemical Effects and Predictive Factors in Premature Birth

2018 ◽  
Vol 69 (7) ◽  
pp. 1796-1801
Author(s):  
Adrian Neacsu ◽  
Alina Calin ◽  
Anca Daniela Braila ◽  
Dan Navolan ◽  
Mihai Dimitriu ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Premature Birth ◽  
Tissue Concentration ◽  
Premature Labor ◽  
New Born ◽  
Uterine Contractions ◽  
Chemical Effects ◽  
Equal Importance ◽  
Necrosis Factor

Premature birth is considered to be the consequence of independent alterations in the cervix and in the uterus. During labor, for full-term birth, as well as for premature birth, the cervix changes, from firm, long and closed, to soft and pliable, through a biochemical process characterized by the reshaping of the extracellular matrix and a growth of the tissue concentration of inflammatory mediators; the uterus proves an increase in contractility and sensitivity to endogenic hormones, such as oxytocin. Premature labor is associated with the premature activation of the release of cytokines in the decidua (mucosa lining uterus walls) and cervix. Interleukins IL-1 beta, IL-6, IL-8 and the alpha tumoral necrosis factor increase the production and activation of matrix metalloproteinases (MMP-1, MMP-3 and MMP-9) and of cathepsin S, which digests the collagen from the extracellular matrix of the cervix, causing the wiping and softening of the cervix. These cytokines are released by leukocytes in the myometer, leading to the production of prostaglandins and oxytocin, which stimulate uterine contractions. Therefore, the cervical shortening represented by ultrasound is believed to represent premature cervical softening. The obstetrical approach of aspects related to premature birth are based, considerably, on the prognosis expected by the obstetrician regarding the survival of the premature new-born baby, as well as the therapeutic variants to be followed. And not only survival is important, of equal importance is also the quality of life of underweight, immature new-born babies, who are considerably affected both physically, and intellectually.

Measured and Modelled Chlorinated Contaminant Distributions in the St. Clair River Water

1986 ◽  
Vol 21 (3) ◽  
pp. 332-343 ◽  
Author(s):  
C.H. Chan ◽  
Y.L. Lau ◽  
B.G. Oliver
Keyword(s):  
River Water ◽  
Suspended Sediment ◽  
Water Samples ◽  
Concentration Distribution ◽  
Suspended Solids ◽  
Industrial Area ◽  
Concentration Profiles ◽  
Detroit River ◽  
Chemical Partitioning ◽  
Transverse Mixing

Abstract The concentration distribution of hexachlorobutadiene (HCBD), pentachloro-benzene (QCB), hexachlorobenzene (HCB) and octachlorostyrene (OCS) in water samples from transects across the upper and lower St. Clair River and the upper Detroit River were determined on four occasions in 1985. The data show a plume of these contaminants from the Sarnia industrial area. The fluxes and concentration profiles of the contaminants at Port Lambton have been modelled success fully using a simple transverse mixing model. A study on the chemical partitioning between the “dissolved” and “suspended sediment” phases shows that an important contaminant fraction is carried in the river by the suspended solids, particularly for lipophilie compounds such as HCB and OCS,

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