Rapid in-vivo measurement of optical and physiological properties in human intraperitoneal tissues before and after photodynamic therapy

Author(s):  
H.-W. Wang ◽  
A. G. Yodh ◽  
T. C. Zhu ◽  
J. Metz ◽  
D. L. Fraker ◽  
...  
2005 ◽  
Author(s):  
Jarod C. Finlay ◽  
Timothy C. Zhu ◽  
Andreea Dimofte ◽  
Diana Stripp ◽  
S. B. Malkowicz ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1776
Author(s):  
Thi Thao Mai ◽  
Su Woong Yoo ◽  
Suhyun Park ◽  
Jin Young Kim ◽  
Kang-Ho Choi ◽  
...  

Vascular damage is one of the therapeutic mechanisms of photodynamic therapy (PDT). In particular, short-term PDT treatments can effectively destroy malignant lesions while minimizing damage to nonmalignant tissue. In this study, we investigate the feasibility of label-free quantitative photoacoustic microscopy (PAM) for monitoring the vasculature changes under the effect of PDT in mouse ear melanoma tumors. In particular, quantitative vasculature evaluation was conducted based on Hessian filter segmentation. Three-dimensional morphological PAM and depth-resolved images before and after PDT treatment were acquired. In addition, five quantitative vasculature parameters, including the PA signal, vessel diameter, vessel density, perfused vessel density, and vessel complexity, were analyzed to evaluate the influence of PDT on four different areas: Two melanoma tumors, and control and normal vessel areas. The quantitative and qualitative results successfully demonstrated the potential of the proposed PAM-based quantitative approach to evaluate the effectiveness of the PDT method.


1981 ◽  
Author(s):  
J L Ambrus ◽  
C M Ambrus ◽  
H Gastpar ◽  
P Spavento ◽  
S Gordon ◽  
...  

In stumptailed monkeys (Macaca arctoides) arteriovenous anastomoses were established. Into these an apparatus was inserted in which blood flows through a 20 micron pore diameter screen and blood pressure is recorded before and after the screen. Injection of 0.1 to 0.5 μgm of ADP or 1 to 2 vgm of serotonine resulted in rapid platelet aggregation on the screen even in heparinized animals. This increased pre-screen pressure and decreased post-screen pressure as recorded with strain gauges. From these data a platelet aggregation index is calculated. Platelet aggregation was significantly decreased by a series of agents which inhibit phosphodiesterases and stimulate release of prostacyclin. This includes several pyrimido- pyrimidine derivatives, methylxantine derivatives, and lmidazoquinazolinones. These agents increased circulation time of intravenously injected labeled polyploid ascites tumor cells. They decreased pulmonary embolism and thrombocytopenia following intravenous injection of tumor cells and decreased development of pulmonary metastases. These methods appear to be suitable to study platelet aggregation inhibitors and their mechanisms of action in vivo.


2006 ◽  
Vol 11 (3) ◽  
pp. 034029 ◽  
Author(s):  
Ann Johansson ◽  
Thomas Johansson ◽  
Marcelo Soto Thompson ◽  
Niels Bendsoe ◽  
Katarina Svanberg ◽  
...  

1994 ◽  
Vol 71 (04) ◽  
pp. 499-506 ◽  
Author(s):  
Mark W C Hatton ◽  
Bonnie Ross-Ouellet

SummaryThe behavior of 125I-labeled recombinant hirudin towards the uninjured and de-endothelialized rabbit aorta wall has been studied in vitro and in vivo to determine its usefulness as an indicator of thrombin activity associated with the aorta wall. Thrombin adsorbed to either sulfopropyl-Sephadex or heparin-Sepharose bound >95% of 125I-r-hirudin and the complex remained bound to the matrix. Binding of 125I-r-hirudin to the exposed aorta subendothelium (intima-media) in vitro was increased substantially if the tissue was pre-treated with thrombin; the quantity of l25I-r-hirudin bound to the de-endothelialized intima-media (i.e. balloon-injured in vitro) correlated positively with the quantity of bound 131I-thrombin (p <0.01). Aortas balloon-injured in vivo were measured for thrombin release from, and binding of 125I-r-hirudin to, the de-endothelialized intimal surface in vitro; 125I-r-hirudin binding correlated with the amount of active thrombin released (p <0.001). Uptake of 125I-r-hirudin by the aorta wall in vivo was proportional to the uptake of 131I-fibrinogen (as an indicator of thrombin activity) before and after balloon injury. After 30 min in the circulation, specific 125I-r-hirudin binding to the uninjured and de-endo- thelialized (at 1.5 h after injury) aorta wall was equivalent to 3.4 (± 2.5) and 25.6 (±18.1) fmol of thrombin/cm2 of intima-media, respectively. Possibly, only hirudin-accessible, glycosaminoglycan-bound thrombin is measured in this way.


1997 ◽  
Vol 78 (04) ◽  
pp. 1202-1208 ◽  
Author(s):  
Marianne Kjalke ◽  
Julie A Oliver ◽  
Dougald M Monroe ◽  
Maureane Hoffman ◽  
Mirella Ezban ◽  
...  

SummaryActive site-inactivated factor VIIa has potential as an antithrombotic agent. The effects of D-Phe-L-Phe-L-Arg-chloromethyl ketone-treated factor VIla (FFR-FVIIa) were evaluated in a cell-based system mimicking in vivo initiation of coagulation. FFR-FVIIa inhibited platelet activation (as measured by expression of P-selectin) and subsequent large-scale thrombin generation in a dose-dependent manner with IC50 values of 1.4 ± 0.8 nM (n = 8) and 0.9 ± 0.7 nM (n = 7), respectively. Kd for factor VIIa binding to monocytes ki for FFR-FVIIa competing with factor VIIa were similar (11.4 ± 0.8 pM and 10.6 ± 1.1 pM, respectively), showing that FFR-FVIIa binds to tissue factor in the tenase complex with the same affinity as factor VIIa. Using platelets from volunteers before and after ingestion of aspirin (1.3 g), there were no significant differences in the IC50 values of FFR-FVIIa [after aspirin ingestion, the IC50 values were 1.7 ± 0.9 nM (n = 8) for P-selectin expression, p = 0.37, and 1.4 ± 1.3 nM (n = 7) for thrombin generation, p = 0.38]. This shows that aspirin treatment of platelets does not influence the inhibition of tissue factor-initiated coagulation by FFR-FVIIa, probably because thrombin activation of platelets is not entirely dependent upon expression of thromboxane A2.


1999 ◽  
Vol 19 (04) ◽  
pp. 168-175 ◽  
Author(s):  
M. Weippert-Kretschmer ◽  
V. Kretschmer

SummaryPerioperative bleeding complications due to disorders of primary haemostasis are often underestimated. Routine determination of primary haemostasis is still problematic. The in vivo bleeding time (BT) shows low sensitivity and high variability. In this contribution the results and experiences with the IVBT having been obtained in various studies and during 10 years of routine use are reported. Patients and Methods: Blood donors before and after ASA ingestion, patients with thrombocytopenia as well as congenital and acquired platelet function disorders. Monitoring of desmopressin efficacy. IVBT with Thrombostat 4000 (tests with CaCl2 = TST-CaCl2 and ADP = TST-ADP) and PFA-100 (test cartridges with epinephrine = PFA-EPI and ADP = PFA-ADP). Results and Conclusions: IVBT becomes abnormal with platelet counts <100,000/μl. With platelet counts <50,000/μl the results are mostly outside the methodical range. IVBT proved clearly superior to BT in von Willebrand syndrome (vWS). All 16 patients with vWS were detected by PFA-EPI, whereas with BT 7 of 10 patients with moderate and 1 of 6 patients with mild forms of vWS were spotted. The majority of acquired and congenital platelet function disorders with relevant bleeding tendency were detectable by IVBT. Sometimes diagnostic problems arose in case of storage pool defect. Four to 12 h after ingestion of a single dose of 100 mg ASA the TST-CaCl2 became abnormal in all cases, the PFA-EPI only in 80%. However, the ASA sensitivity of TST-CaCl2 proved even too high when looking for perioperative bleeding complications in an urological study. Therefore, the lower ASS sensitivity of the PFA-100 seems to be rather advantageous for the estimation of a real bleeding risk. The good efficacy of desmopressin in the majority of cases with mild thrombocytopenia, congenital and acquired platelet function disorders and even ASS-induced platelet dysfunction could be proven by means of the IVBT. Thus IVBT may help to increase the reliability of the therapy. However, the IVBT with the PFA-100 is not yet fully developed. Nevertheless, routine use can be recommended when special methodical guidelines are followed.


2020 ◽  
Vol 1 (12) ◽  
pp. 40-42
Author(s):  
F. Yu. Daurova ◽  
D. I. Tomaeva ◽  
S. V. Podkopaeva ◽  
Yu. A. Taptun

Relevance: the reason for the development of complications in endodontic treatment is poor-quality instrumental treatment root canals.Aims: a study of the animicrobial action and clinical efficacy of high-frequency monopolar diathermocoagulation in the treatment of chronic forms of pulpitis.Materials and methods: 102 patients with various chronic forms of pulpitis were divided into three groups of 34 patients each. In the first two groups, high-frequency monopolar diathermocoagulation was used in endodontic treatment in different modes. In the third group, endodontic treatment was carried out without the use of diathermocoagulation (comparison group). The root canal microflora in chronic pulpitis in vivo was studied twice-before and after diathermocoagulation.Results: it was established that high-frequency monopolar diathermocoagulation in the effect mode is 3, power is 4 (4.1 W) and effect is 4, power is 4 (5.4 W) with an exposure time of 3 seconds, it has a pronounced antibacterial effect on all presented pathogenic microflora obtained from the root canals of the teeth.


Sign in / Sign up

Export Citation Format

Share Document