Fluorescence spectral techniques are very sensitive, and hence they are gaining importance in cancer detection. The biomarkers indicative of cancer could be identified and quantified by spectral or time domain fluorescence spectroscopy. The results of an investigation of time-resolved spectra of cellular components of blood obtained from cervical cancer patients and normal controls are given. The cancer indicative biomarker in this paper is porphyrin; it has a fluorescence decay time of 60% more in samples of cancer patients than those of normal controls. Based on such measurements, a randomized set comprising samples from cancer patients and controls (N=27 in total) could be classified with sensitivity (92%) and specificity (86%).
In the current study, the fluorescence emission spectra (FES) and Stokes shift spectra (SSS) of blood and urine samples of cervical cancer patients were obtained and compared to those of normal controls. Both spectra showed that the relative intensity of biomolecules such as porphyrin, collagen, Nicotinamide adenine dinucleotide, and flavin were quite out of proportion in cervical cancer patients. The biochemical mechanism for the elevation of these fluorophores is not yet definitive; nevertheless, these biomolecules could serve as tumor markers for diagnosis, screening, and follow-up of cervical cancers. To the best of our knowledge, this is the first report on FES and SSS of blood and urine of cervical cancer patients to give a sensitivity of 80% and specificity of 78%.
Liver cancer or hepatocellular carcinoma (HCC) is a serious malady with only 10% survival rate. HCC incidence and
mortality both are highest in China. This disease is detected and diagnosed by ultra sound, CT or MRI scans which are
quite expensive. Also the discrimination between cirrhosis and HCC are poor by this imaging technique. The
conventional tissue biopsy is quite invasive and painful. In this context, in the new diagnostic procedure presented in this
paper, all the three liver malfunctions, particularly liver cancer, could be detected and discriminated by the spectral
feature of blood and urine with accuracy about 80%. All that we need are 5 ml of blood and 5 ml of urine. Hence this
inexpensive non invasive, optical technique will have significant impact in screening, diagnosis and also prognosis of
HCC in large segment of people in the populous Asian countries.
Gleason score is the most common method of grading the virulence of prostate malignancy and is based on the
pathological assessment of morphology of cellular matrix. Since this involves the excision of the tissue, we are working
on a new, minimally invasive, non contact, procedure of spectral diagnosis of prostate malignancy. In this preliminary in
vitro study reported here, we have analyzed 27 tissue samples (normal control =7: benign=8: malignant =12) by Stokes'
shift spectra (SSS) to establish a one- to- one correlation between spectral grading and Gleason grading.
Histo pathological examination is the gold standard to discriminate between benign and malignant growth of tissue. But
this is invasive and stressful. Hence many non invasive imaging techniques, such as CT, MRI, PET, etc are employed,
each having certain advantages and disadvantages. In this context optical biopsy is a newly emerging technique, since it
employs non-ionizing radiation like light or laser, which could be shined directly or launched through optical fiber to
reach any part of the body.
This paper reports results of time resolved emission spectra of 24 excised tissue sample (normal control=12; benign=4;
malignant=8) of breast and prostate, employing a 390nm, 100 fs, Ti-Sapphire laser pulses.
The fluorescence decay times were measured using streak camera and fitted for single and bi- exponential decays with
reliability of 97%. Our results show the distinct difference between normal, benign and malignant tissues attributed
changes of NADH and FAD levels.
High false positives and over diagnosis is a major problem with management of prostate
cancer. A non-invasive or a minimally invasive technique to accurately distinguish
malignant prostate cancers from benign tumors will be extremely helpful to overcome
this problem.
In this paper, we had used three different fluorescence spectroscopy techniques viz.,
Fluorescence Emission Spectrum (FES), Stokes' Shift Spectrum (SSS) and Reflectance
Spectrum (RS) to discriminate benign prostate tumor tissues (N=12) and malignant
prostate cancer tissues (N=8). These fluorescence techniques were used to determine the
relative concentration of naturally occurring biomolecules such as tryptophan, elastin,
NADH and flavin which are found to be out of proportion in cancer tissues. Our studies
show that combining all three techniques, benign and malignant prostate tissues could be
classified with accuracy greater than 90%.
This preliminary report is based on in vitro spectroscopy analysis. However, by
employing fluorescence endoscopy techniques, this can be extended to in vivo analysis as
well. This technique has the potential to identify malignant prostate tissues without
surgery.
Conjugate Polymers are novel optoelectronic materials with wide range of
applications. In this paper, we present the results of fluorescence and laser excited amplified
emission spectra of MEH-PPV polymer, which has some surprising laser properties.
(MEH -PPV) is a complex macro molecule. When this is dissolved in liquids like,
tetra hydro furan (THF), it is very fluorescent, with quantum yield comparable to
conventional laser dyes. This polymer has absorption peak around 490nm and emission peak
at 560nm for a low concentration (1 micro molar). However for higher concentration (10
micro molar) it has a new band at 600nm, in emission only without any new band in
absorption. This is a strong indication of excimer formation.
When this particular solution is pumped by a 3rd harmonic of Nd-YAG laser (355nm
and 11 ns), the polymer underwent strong excitation and population inversion and amplified
spontaneous emission (ASE) at 600 nm only. For lower concentration, we could get
fluorescence only with a peak at 560 nm. That is, this particular polymer produces ASE and
hence laser only from the excimeric state. It is important note that most of the liquid laser
dyes do not produce laser from the excimeric state; other solutions which are easily
forming excimeric state do not laze. This appears to be the only liquid excimeric state laser.
Another important feature of the solution it is at least 10 times more stable than the
conventional laser dyes.
In this work, we had studied the Amplified Spontaneous Emission( ASE)
properties of polymer BEHP-co-MEH-PPV in THF, under pulsed laser excitation. In
our earlier communication, we had shown that MEH-PPV alone could produce ASE
under pulsed Nd: YAG laser excitation only in its excimeric state. A follow up study
reported here, on conjugated polymer shows that in BEHP-co-MEH-PPV, the BEH-PPPV
component is capable of forcing MEH-PPV to produce ASE at 560nm, which
appears to arise out of the monomeric state of MEH-PPV.
It is important to note that BEHP-PPV as a part of the compound could get
excited by pump laser pulse, and transfer its excitation energy internally to MEH-PV
helping MEH-PPV to produce ASE in non excimeric state. Also we had investigated
the energy-transfer process externally from the donor coumarin485 (C485) to acceptor
MEH-PPV By this processes also MEH- PPV could be forced to produce ASE from
the monomeric state
In this paper we present the results of a study to distinguish cervical cancer patients [
N=50] from healthy subjects [N=50] based on the Fluorescence Emission Spectra [FES]
and Stokes' Shift Spectra [SSS] of blood and urine. FES was obtained from the cellular
fraction of blood and urine by excitation at 400 nm. SSS was obtained from blood plasma
and urine with Δλ of 70nm. In the FES of blood cellular fraction, the ratio of intensity of
the two bands due to neutral porphyrin and basic porphyrin [I630 / I580] was 1 for
normal controls and 3 for cervical cancers. In the SSS of plasma, the average ratio of
intensity of the two bands due to tryptophan and collagen [I305 nm / I340 nm] was 1.9
for normal controls, 1.1 for early cervical cancers and 0.9 for advanced cervical cancers
In the SSS of urine, the ratio of intensity of the two bands due to flavin and NADH [I450
nm / I360 nm] was 0.2 for normal controls and 0.8 for cancer patients. A discriminant
analysis combining all three parameters showed a sensitivity of 80% and specificity of
78% for this technique. In this study we show that fluorescence spectroscopy of blood
and urine could develop into a promising technique for non-invasive diagnosis and
screening of cervical cancers and would appropriately supplement or complement
currently used techniques.
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