Yang Pu - Academia.edu (original) (raw)

Papers by Yang Pu

Research paper thumbnail of Functional vascular imaging by Photoacoustic Microscopy (PAM) and its biomedical application

Research paper thumbnail of Errata: Changes of collagen and nicotinamide adenine dinucleotide in human cancerous and normal prostate tissues studied using native fluorescence spectroscopy with selective excitation wavelength

Journal of Biomedical Optics, 2010

This article ͓J. Biomed. Opt. 15, 047008 ͑2010͔͒ was originally published online on 23 July 2010 ... more This article ͓J. Biomed. Opt. 15, 047008 ͑2010͔͒ was originally published online on 23 July 2010 with two errors in the author list. The author listed as "Wubao B. Wang" should have been listed as "Wubao Wang" and "Guichen C. Tang" should have been listed as "Guichen Tang." All versions of the article were corrected on 30 July 2010.

Research paper thumbnail of Intravital imaging by simultaneous label-free autofluorescence-multiharmonic microscopy

Nature communications, May 29, 2018

Intravital microscopy (IVM) emerged and matured as a powerful tool for elucidating pathways in bi... more Intravital microscopy (IVM) emerged and matured as a powerful tool for elucidating pathways in biological processes. Although label-free multiphoton IVM is attractive for its non-perturbative nature, its wide application has been hindered, mostly due to the limited contrast of each imaging modality and the challenge to integrate them. Here we introduce simultaneous label-free autofluorescence-multiharmonic (SLAM) microscopy, a single-excitation source nonlinear imaging platform that uses a custom-designed excitation window at 1110 nm and shaped ultrafast pulses at 10 MHz to enable fast (2-orders-of-magnitude improvement), simultaneous, and efficient acquisition of autofluorescence (FAD and NADH) and second/third harmonic generation from a wide array of cellular and extracellular components (e.g., tumor cells, immune cells, vesicles, and vessels) in living tissue using only 14 mW for extended time-lapse investigations. Our work demonstrates the versatility and efficiency of SLAM micr...

Research paper thumbnail of Using WeChat clinician-patient group communication data to identify symptom burdens in patients with uterine fibroids under focused ultrasound ablation surgery treatment :Qualitative Study (Preprint)

JMIR formative research, Nov 2, 2022

Background Unlike research project–based health data collection (questionnaires and interviews), ... more Background Unlike research project–based health data collection (questionnaires and interviews), social media platforms allow patients to freely discuss their health status and obtain peer support. Previous literature has pointed out that both public and private social platforms can serve as data sources for analysis. Objective This study aimed to use natural language processing (NLP) techniques to identify concerns regarding the postoperative quality of life and symptom burdens in patients with uterine fibroids after focused ultrasound ablation surgery. Methods Screenshots taken from clinician-patient WeChat groups were converted into free texts using image text recognition technology and used as the research object of this study. From 408 patients diagnosed with uterine fibroids in Chongqing Haifu Hospital between 2010 and 2020, we searched for symptom burdens in over 900,000 words of WeChat group chats. We first built a corpus of symptoms by manually coding 30% of the WeChat texts and then used regular expressions in Python to crawl symptom information from the remaining texts based on this corpus. We compared the results with a manual review (gold standard) of the same records. Finally, we analyzed the relationship between the population baseline data and conceptual symptoms; quantitative and qualitative results were examined. Results A total of 408 patients with uterine fibroids were included in the study; 190,000 words of free text were obtained after data cleaning. The mean age of the patients was 39.94 (SD 6.81) years, and their mean BMI was 22.18 (SD 2.78) kg/m2. The median reporting times of the 7 major symptoms were 21, 26, 57, 2, 18, 30, and 49 days. Logistic regression models identified preoperative menstrual duration (odds ratio [OR] 1.14, 95% CI 5.86-6.37; P=.009), age of menophania (OR –1.02 , 95% CI 11.96-13.47; P=.03), and the number (OR 2.34, 95% CI 1.45-1.83; P=.04) and size of fibroids (OR 0.12, 95% CI 2.43-3.51; P=.04) as significant risk factors for postoperative symptoms. Conclusions Unstructured free texts from social media platforms extracted by NLP technology can be used for analysis. By extracting the conceptual information about patients’ health-related quality of life, we can adopt personalized treatment for patients at different stages of recovery to improve their quality of life. Python-based text mining of free-text data can accurately extract symptom burden and save considerable time compared to manual review, maximizing the utility of the extant information in population-based electronic health records for comparative effectiveness research.

Research paper thumbnail of Optical Spectral Fingerprints of Tissues from Patients with Different Breast Cancer Histologies Using a Novel Fluorescence Spectroscopic Device

Technology in Cancer Research & Treatment, Oct 1, 2013

Research paper thumbnail of Combined spatial frequency spectroscopy analysis with visible resonance Raman for optical biopsy of human brain metastases of lung cancers

Journal of Innovative Optical Health Sciences, Mar 1, 2019

The purpose of this study is to examine optical spatial frequency spectroscopy analysis (SFSA) co... more The purpose of this study is to examine optical spatial frequency spectroscopy analysis (SFSA) combined with visible resonance Raman (VRR) spectroscopic method, for the¯rst time, to discriminate human brain metastases of lung cancers adenocarcinoma (ADC) and squamous cell carcinoma (SCC) from normal tissues. A total of 31 label-free micrographic images of three types † † Corresponding author.

Research paper thumbnail of Spectral analysis of tissues from patients with cancer using a portable spectroscopic diagnostic ratiometer unit

Proceedings of SPIE, May 8, 2014

ABSTRACT Spectral profiles of tissues from patients with breast carcinoma, malignant carcinoid an... more ABSTRACT Spectral profiles of tissues from patients with breast carcinoma, malignant carcinoid and non-small cell lung carcinoma were acquired using native fluorescence spectroscopy. A novel spectroscopic ratiometer device (S3-LED) with selective excitation wavelengths at 280 nm and 335 nm was used to produce the emission spectra of the key biomolecules, tryptophan and NADH, in the tissue samples. In each of the samples, analysis of emission intensity peaks from biomolecules showed increased 340 nm1440 nm and 340 nm1460 nm ratios in the malignant samples compared to their paired normal samples. This most likely represented increased tryptophan to NADH ratios in the malignant tissue samples compared to their paired normal samples. Among the non-small cell lung carcinoma and breast carcinomas, it appeared that tumors of very large size or poor differentiation had an even greater increase in the 340 nm/440 nm and 340 nm/460 nm ratios. In the samples of malignant carcinoid, which is known to be a highly metabolically active tumor, a marked increase in these ratios was also seen.

Research paper thumbnail of Prostate precancer detection by Stokes Shift Spectroscopy

Proceedings of SPIE, Feb 10, 2011

ABSTRACT Stokes Shift Spectroscopy (SSS) has emerged as a promising modality in the discriminatio... more ABSTRACT Stokes Shift Spectroscopy (SSS) has emerged as a promising modality in the discrimination of normal from different pathological prostate tissues. Stokes shift (SS) spectra is measured by simultaneously scanning both the excitation and emission wavelengths while keeping a fixed wavelength interval Δλ=20 nm between them. Characteristic, highly resolved peaks and significant spectral differences between normal and different pathological prostate tissues were observed. The SS spectra of normal, hyperplasia and malignant tissues shows the distinct peaks around 300, 345, 440 and 510 nm is attributed to tryptophan, collagen, NADH and flavin respectively. To quantify the spectral differences between normal and different pathological prostate tissues are verified by statistical analysis.

Research paper thumbnail of Spectral grading and Gleason grading of malignant prostate tissue using Stokes shift spectra

Proceedings of SPIE, Feb 9, 2012

ABSTRACT Gleason score is the most common method of grading the virulence of prostate malignancy ... more ABSTRACT 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.

Research paper thumbnail of Nonnegative constraint analysis of key fluorophores within human breast cancer using native fluorescence spectroscopy excited by selective wavelength of 300 nm

Proceedings of SPIE, Mar 11, 2015

ABSTRACT

Research paper thumbnail of Second and third NIR optical windows for imaging of bone microfractures

Proceedings of SPIE, May 8, 2014

ABSTRACT Microfractures in bone, secondary to repetitive stress, particularly in the lower extrem... more ABSTRACT Microfractures in bone, secondary to repetitive stress, particularly in the lower extremities, are an important problem for military recruits and for athletes. They also may occur in those with brittle bones, such as the elderly, or in patients taking bisphosphonates for osteoporosis. Microfractures can be early predictors of major bone fracture and may be as important as changes in bone density in predicting where and how likely a major fracture will occur. Unlike major bone fractures, microfractures can be difficult to detect by conventional methods. We explored a second NIR spectral window from 1,100 nm to 1,350 nm, and a third spectral window from 1,600 nm to 1,870 nm to image microfractures through tissue media. Due to a reduction in scattering at longer NIR wavelengths, employment of the second and third NIR windows may allow for deeper penetration into tissue and higher contrast images of microfractures underneath the skin.

Research paper thumbnail of High histologic grade and increased relative content of tryptophan in breast cancer using ratios from fingerprint fluorescence spectral peaks

Proceedings of SPIE, Mar 11, 2015

ABSTRACT Histologic grade is a very important, but underappreciated, parameter of breast cancer a... more ABSTRACT Histologic grade is a very important, but underappreciated, parameter of breast cancer aggressiveness. Despite its importance, it has historically not been included as one of the criteria for staging of this cancer. In this study, spectral fluorescence profiles from patients with breast carcinoma were acquired. Ratios of emission peaks at 340 over 440,460 nm from biomolecules in malignant and normal samples were calculated. Cancerous over normal ratios (double ratio (DR) method) were evaluated with respect to tumor characteristics. Increased tryptophan content in breast cancer tissues correlates strongly with high grade, but not with lymph node metastases, estrogen receptor, progesterone receptor or Her-2-Neu receptor status.

Research paper thumbnail of A comparison study of different excitation wavelengths to determine the relative content of key biomolecules in breast cancer and breast normal tissue

Proceedings of SPIE, Mar 11, 2015

ABSTRACT Fluorescence profiles from breast cancer and breast normal tissue samples with excitatio... more ABSTRACT Fluorescence profiles from breast cancer and breast normal tissue samples with excitation wavelengths at 280 nm and 340 nm were obtained using the conventional LS-50 Perkin-Elmer spectrometer. Fluorescence ratios from these tissue samples, demonstrated by emission peaks at 340 nm, 440 nm and 460 nm and likely representing tryptophan and NADH, show increased relative content of tryptophan in malignant samples. Double ratio (DR) techniques were used to measure the severity of disease. The single excitation double ratio (Single-DR) method utilizes the emission intensity peaks from the spectrum acquired using a single excitation of 280 nm; while the dual excitation double ratio (dual-DR) method utilizes the emission intensity peaks from the spectra acquired using an excitation of 280 nm and 340 nm. Single-DR and dual-DR from 13 patients with breast carcinoma were compared in terms of their efficiency to distinguish high from low/intermediate tumors. Similar results were found with both methods. Results suggest that dual excitation wavelengths may be as effective as single excitation wavelength in calculating the relative content of biomolecules in breast cancer tissue, as well as for the assessment of the malignant potential of these tumors.

Research paper thumbnail of Resonance Raman spectroscopy for human cancer detection of key molecules with clinical diagnosis

Proceedings of SPIE, Mar 19, 2013

ABSTRACT

Research paper thumbnail of Tryptophan as key biomarker to detect gastrointestinal tract cancer using non-negative biochemical analysis of native fluorescence and Stokes Shift spectroscopy

Proceedings of SPIE, Mar 11, 2015

ABSTRACT

Research paper thumbnail of Deep tissue imaging of microfracture and non-displaced fracture of bone using the second and third near-infrared therapeutic windows

Proceedings of SPIE, Mar 4, 2014

Near-infrared (NIR) light in the wavelengths of 700 nm to 2,000 nm has three NIR optical, or ther... more Near-infrared (NIR) light in the wavelengths of 700 nm to 2,000 nm has three NIR optical, or therapeutic, windows, which allow for deeper depth penetration in scattering tissue media. Microfractures secondary to repetitive stress, particularly in the lower extremities, are an important problem for military recruits and athletes. They also frequently occur in the elderly, or in patients taking bisphosphonates or denosumab. Microfractures can be early predictors of a major bone fracture. Using the second and third NIR therapeutic windows, we investigated the results from images of chicken bone and human tibial bone with microfractures and non-displaced fractures with and without overlying tissues of various thicknesses. Images of bone with microfractures and non-displaced fractures with tissue show scattering photons in the third NIR window with wavelengths between 1,650 nm and 1,870 nm are diminished and absorption is increased slightly from and second NIR windows. Results from images of fractured bones show the attenuation length of light through tissue in the third optical window to be larger than in the second therapeutic window. Use of these windows may aid in the detection of bone microfractures, and thus reduce the incidence of major bone fracture in susceptible groups.

Research paper thumbnail of Tumor margin detection using optical biopsy techniques

Proceedings of SPIE, Mar 17, 2014

Research paper thumbnail of Time-resolved fluorescence for breast cancer detection using an octreotate-indocyanine green derivative dye conjugate

Proceedings of SPIE, Mar 19, 2013

ABSTRACT Time-resolved fluorescence was used to investigate malignant and normal adjacent breast ... more ABSTRACT Time-resolved fluorescence was used to investigate malignant and normal adjacent breast tissues stained with a conjugate of indocyanine green and octreotate. A marked increase in fluorescence lifetime intensity was seen in the breast cancer sample compared to the normal sample. The fluorescent lifetimes were also investigated and showed similar fluorescence decay curves in stained malignant and normal breast tissue. These results confirm that somatostatin receptors occur on human breast carcinomas, suggest that the presence of somatostatin receptors should be investigated as a marker of breast cancer aggressiveness, and suggest that this conjugate might be used to detect the presence of residual breast cancer after surgery, allowing better assessment of tumor margins and reducing the need for second or repeat biopsies in selected patients. These results may also provide clues for designing future treatment options for breast cancer patients.

Research paper thumbnail of Brain metastasis detection by resonant Raman optical biopsy method

Proceedings of SPIE, Mar 17, 2014

Research paper thumbnail of Differences in fluorescence profiles from breast cancer tissues due to changes in relative tryptophan content via energy transfer: tryptophan content correlates with histologic grade and tumor size but not with lymph node metastases

Journal of Biomedical Optics, Dec 18, 2014

The correlation between histologic grade, an increasingly important measure of prognosis for pati... more The correlation between histologic grade, an increasingly important measure of prognosis for patients with breast cancer, and tryptophan levels from tissues of 15 breast carcinoma patients was investigated. Changes in the relative content of key native organic biomolecule tryptophan were seen from the fluorescence spectra of cancerous and paired normal tissues with excitation wavelengths of 280 and 300 nm. Due to a large spectral overlap and matching excitation-emission spectra, fluorescence resonance energy transfer from tryptophan-donor to reduced nicotinamide adenine dinucleotides-acceptor was noted. We used the ratios of fluorescence intensities at their spectral emission peaks, or spectral fingerprint peaks, at 340, 440, and 460 nm. Higher ratios correlated strongly with high histologic grade, while lower-grade tumors had low ratios. Large tumor size also correlated with high ratios, while the number of lymph node metastases, a major factor in staging, was not correlated with tryptophan levels. High histologic grade correlates strongly with increased content of tryptophan in breast cancer tissues and suggests that measurement of tryptophan content may be useful as a part of the evaluation of these patients.

Research paper thumbnail of Functional vascular imaging by Photoacoustic Microscopy (PAM) and its biomedical application

Research paper thumbnail of Errata: Changes of collagen and nicotinamide adenine dinucleotide in human cancerous and normal prostate tissues studied using native fluorescence spectroscopy with selective excitation wavelength

Journal of Biomedical Optics, 2010

This article ͓J. Biomed. Opt. 15, 047008 ͑2010͔͒ was originally published online on 23 July 2010 ... more This article ͓J. Biomed. Opt. 15, 047008 ͑2010͔͒ was originally published online on 23 July 2010 with two errors in the author list. The author listed as "Wubao B. Wang" should have been listed as "Wubao Wang" and "Guichen C. Tang" should have been listed as "Guichen Tang." All versions of the article were corrected on 30 July 2010.

Research paper thumbnail of Intravital imaging by simultaneous label-free autofluorescence-multiharmonic microscopy

Nature communications, May 29, 2018

Intravital microscopy (IVM) emerged and matured as a powerful tool for elucidating pathways in bi... more Intravital microscopy (IVM) emerged and matured as a powerful tool for elucidating pathways in biological processes. Although label-free multiphoton IVM is attractive for its non-perturbative nature, its wide application has been hindered, mostly due to the limited contrast of each imaging modality and the challenge to integrate them. Here we introduce simultaneous label-free autofluorescence-multiharmonic (SLAM) microscopy, a single-excitation source nonlinear imaging platform that uses a custom-designed excitation window at 1110 nm and shaped ultrafast pulses at 10 MHz to enable fast (2-orders-of-magnitude improvement), simultaneous, and efficient acquisition of autofluorescence (FAD and NADH) and second/third harmonic generation from a wide array of cellular and extracellular components (e.g., tumor cells, immune cells, vesicles, and vessels) in living tissue using only 14 mW for extended time-lapse investigations. Our work demonstrates the versatility and efficiency of SLAM micr...

Research paper thumbnail of Using WeChat clinician-patient group communication data to identify symptom burdens in patients with uterine fibroids under focused ultrasound ablation surgery treatment :Qualitative Study (Preprint)

JMIR formative research, Nov 2, 2022

Background Unlike research project–based health data collection (questionnaires and interviews), ... more Background Unlike research project–based health data collection (questionnaires and interviews), social media platforms allow patients to freely discuss their health status and obtain peer support. Previous literature has pointed out that both public and private social platforms can serve as data sources for analysis. Objective This study aimed to use natural language processing (NLP) techniques to identify concerns regarding the postoperative quality of life and symptom burdens in patients with uterine fibroids after focused ultrasound ablation surgery. Methods Screenshots taken from clinician-patient WeChat groups were converted into free texts using image text recognition technology and used as the research object of this study. From 408 patients diagnosed with uterine fibroids in Chongqing Haifu Hospital between 2010 and 2020, we searched for symptom burdens in over 900,000 words of WeChat group chats. We first built a corpus of symptoms by manually coding 30% of the WeChat texts and then used regular expressions in Python to crawl symptom information from the remaining texts based on this corpus. We compared the results with a manual review (gold standard) of the same records. Finally, we analyzed the relationship between the population baseline data and conceptual symptoms; quantitative and qualitative results were examined. Results A total of 408 patients with uterine fibroids were included in the study; 190,000 words of free text were obtained after data cleaning. The mean age of the patients was 39.94 (SD 6.81) years, and their mean BMI was 22.18 (SD 2.78) kg/m2. The median reporting times of the 7 major symptoms were 21, 26, 57, 2, 18, 30, and 49 days. Logistic regression models identified preoperative menstrual duration (odds ratio [OR] 1.14, 95% CI 5.86-6.37; P=.009), age of menophania (OR –1.02 , 95% CI 11.96-13.47; P=.03), and the number (OR 2.34, 95% CI 1.45-1.83; P=.04) and size of fibroids (OR 0.12, 95% CI 2.43-3.51; P=.04) as significant risk factors for postoperative symptoms. Conclusions Unstructured free texts from social media platforms extracted by NLP technology can be used for analysis. By extracting the conceptual information about patients’ health-related quality of life, we can adopt personalized treatment for patients at different stages of recovery to improve their quality of life. Python-based text mining of free-text data can accurately extract symptom burden and save considerable time compared to manual review, maximizing the utility of the extant information in population-based electronic health records for comparative effectiveness research.

Research paper thumbnail of Optical Spectral Fingerprints of Tissues from Patients with Different Breast Cancer Histologies Using a Novel Fluorescence Spectroscopic Device

Technology in Cancer Research & Treatment, Oct 1, 2013

Research paper thumbnail of Combined spatial frequency spectroscopy analysis with visible resonance Raman for optical biopsy of human brain metastases of lung cancers

Journal of Innovative Optical Health Sciences, Mar 1, 2019

The purpose of this study is to examine optical spatial frequency spectroscopy analysis (SFSA) co... more The purpose of this study is to examine optical spatial frequency spectroscopy analysis (SFSA) combined with visible resonance Raman (VRR) spectroscopic method, for the¯rst time, to discriminate human brain metastases of lung cancers adenocarcinoma (ADC) and squamous cell carcinoma (SCC) from normal tissues. A total of 31 label-free micrographic images of three types † † Corresponding author.

Research paper thumbnail of Spectral analysis of tissues from patients with cancer using a portable spectroscopic diagnostic ratiometer unit

Proceedings of SPIE, May 8, 2014

ABSTRACT Spectral profiles of tissues from patients with breast carcinoma, malignant carcinoid an... more ABSTRACT Spectral profiles of tissues from patients with breast carcinoma, malignant carcinoid and non-small cell lung carcinoma were acquired using native fluorescence spectroscopy. A novel spectroscopic ratiometer device (S3-LED) with selective excitation wavelengths at 280 nm and 335 nm was used to produce the emission spectra of the key biomolecules, tryptophan and NADH, in the tissue samples. In each of the samples, analysis of emission intensity peaks from biomolecules showed increased 340 nm1440 nm and 340 nm1460 nm ratios in the malignant samples compared to their paired normal samples. This most likely represented increased tryptophan to NADH ratios in the malignant tissue samples compared to their paired normal samples. Among the non-small cell lung carcinoma and breast carcinomas, it appeared that tumors of very large size or poor differentiation had an even greater increase in the 340 nm/440 nm and 340 nm/460 nm ratios. In the samples of malignant carcinoid, which is known to be a highly metabolically active tumor, a marked increase in these ratios was also seen.

Research paper thumbnail of Prostate precancer detection by Stokes Shift Spectroscopy

Proceedings of SPIE, Feb 10, 2011

ABSTRACT Stokes Shift Spectroscopy (SSS) has emerged as a promising modality in the discriminatio... more ABSTRACT Stokes Shift Spectroscopy (SSS) has emerged as a promising modality in the discrimination of normal from different pathological prostate tissues. Stokes shift (SS) spectra is measured by simultaneously scanning both the excitation and emission wavelengths while keeping a fixed wavelength interval Δλ=20 nm between them. Characteristic, highly resolved peaks and significant spectral differences between normal and different pathological prostate tissues were observed. The SS spectra of normal, hyperplasia and malignant tissues shows the distinct peaks around 300, 345, 440 and 510 nm is attributed to tryptophan, collagen, NADH and flavin respectively. To quantify the spectral differences between normal and different pathological prostate tissues are verified by statistical analysis.

Research paper thumbnail of Spectral grading and Gleason grading of malignant prostate tissue using Stokes shift spectra

Proceedings of SPIE, Feb 9, 2012

ABSTRACT Gleason score is the most common method of grading the virulence of prostate malignancy ... more ABSTRACT 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.

Research paper thumbnail of Nonnegative constraint analysis of key fluorophores within human breast cancer using native fluorescence spectroscopy excited by selective wavelength of 300 nm

Proceedings of SPIE, Mar 11, 2015

ABSTRACT

Research paper thumbnail of Second and third NIR optical windows for imaging of bone microfractures

Proceedings of SPIE, May 8, 2014

ABSTRACT Microfractures in bone, secondary to repetitive stress, particularly in the lower extrem... more ABSTRACT Microfractures in bone, secondary to repetitive stress, particularly in the lower extremities, are an important problem for military recruits and for athletes. They also may occur in those with brittle bones, such as the elderly, or in patients taking bisphosphonates for osteoporosis. Microfractures can be early predictors of major bone fracture and may be as important as changes in bone density in predicting where and how likely a major fracture will occur. Unlike major bone fractures, microfractures can be difficult to detect by conventional methods. We explored a second NIR spectral window from 1,100 nm to 1,350 nm, and a third spectral window from 1,600 nm to 1,870 nm to image microfractures through tissue media. Due to a reduction in scattering at longer NIR wavelengths, employment of the second and third NIR windows may allow for deeper penetration into tissue and higher contrast images of microfractures underneath the skin.

Research paper thumbnail of High histologic grade and increased relative content of tryptophan in breast cancer using ratios from fingerprint fluorescence spectral peaks

Proceedings of SPIE, Mar 11, 2015

ABSTRACT Histologic grade is a very important, but underappreciated, parameter of breast cancer a... more ABSTRACT Histologic grade is a very important, but underappreciated, parameter of breast cancer aggressiveness. Despite its importance, it has historically not been included as one of the criteria for staging of this cancer. In this study, spectral fluorescence profiles from patients with breast carcinoma were acquired. Ratios of emission peaks at 340 over 440,460 nm from biomolecules in malignant and normal samples were calculated. Cancerous over normal ratios (double ratio (DR) method) were evaluated with respect to tumor characteristics. Increased tryptophan content in breast cancer tissues correlates strongly with high grade, but not with lymph node metastases, estrogen receptor, progesterone receptor or Her-2-Neu receptor status.

Research paper thumbnail of A comparison study of different excitation wavelengths to determine the relative content of key biomolecules in breast cancer and breast normal tissue

Proceedings of SPIE, Mar 11, 2015

ABSTRACT Fluorescence profiles from breast cancer and breast normal tissue samples with excitatio... more ABSTRACT Fluorescence profiles from breast cancer and breast normal tissue samples with excitation wavelengths at 280 nm and 340 nm were obtained using the conventional LS-50 Perkin-Elmer spectrometer. Fluorescence ratios from these tissue samples, demonstrated by emission peaks at 340 nm, 440 nm and 460 nm and likely representing tryptophan and NADH, show increased relative content of tryptophan in malignant samples. Double ratio (DR) techniques were used to measure the severity of disease. The single excitation double ratio (Single-DR) method utilizes the emission intensity peaks from the spectrum acquired using a single excitation of 280 nm; while the dual excitation double ratio (dual-DR) method utilizes the emission intensity peaks from the spectra acquired using an excitation of 280 nm and 340 nm. Single-DR and dual-DR from 13 patients with breast carcinoma were compared in terms of their efficiency to distinguish high from low/intermediate tumors. Similar results were found with both methods. Results suggest that dual excitation wavelengths may be as effective as single excitation wavelength in calculating the relative content of biomolecules in breast cancer tissue, as well as for the assessment of the malignant potential of these tumors.

Research paper thumbnail of Resonance Raman spectroscopy for human cancer detection of key molecules with clinical diagnosis

Proceedings of SPIE, Mar 19, 2013

ABSTRACT

Research paper thumbnail of Tryptophan as key biomarker to detect gastrointestinal tract cancer using non-negative biochemical analysis of native fluorescence and Stokes Shift spectroscopy

Proceedings of SPIE, Mar 11, 2015

ABSTRACT

Research paper thumbnail of Deep tissue imaging of microfracture and non-displaced fracture of bone using the second and third near-infrared therapeutic windows

Proceedings of SPIE, Mar 4, 2014

Near-infrared (NIR) light in the wavelengths of 700 nm to 2,000 nm has three NIR optical, or ther... more Near-infrared (NIR) light in the wavelengths of 700 nm to 2,000 nm has three NIR optical, or therapeutic, windows, which allow for deeper depth penetration in scattering tissue media. Microfractures secondary to repetitive stress, particularly in the lower extremities, are an important problem for military recruits and athletes. They also frequently occur in the elderly, or in patients taking bisphosphonates or denosumab. Microfractures can be early predictors of a major bone fracture. Using the second and third NIR therapeutic windows, we investigated the results from images of chicken bone and human tibial bone with microfractures and non-displaced fractures with and without overlying tissues of various thicknesses. Images of bone with microfractures and non-displaced fractures with tissue show scattering photons in the third NIR window with wavelengths between 1,650 nm and 1,870 nm are diminished and absorption is increased slightly from and second NIR windows. Results from images of fractured bones show the attenuation length of light through tissue in the third optical window to be larger than in the second therapeutic window. Use of these windows may aid in the detection of bone microfractures, and thus reduce the incidence of major bone fracture in susceptible groups.

Research paper thumbnail of Tumor margin detection using optical biopsy techniques

Proceedings of SPIE, Mar 17, 2014

Research paper thumbnail of Time-resolved fluorescence for breast cancer detection using an octreotate-indocyanine green derivative dye conjugate

Proceedings of SPIE, Mar 19, 2013

ABSTRACT Time-resolved fluorescence was used to investigate malignant and normal adjacent breast ... more ABSTRACT Time-resolved fluorescence was used to investigate malignant and normal adjacent breast tissues stained with a conjugate of indocyanine green and octreotate. A marked increase in fluorescence lifetime intensity was seen in the breast cancer sample compared to the normal sample. The fluorescent lifetimes were also investigated and showed similar fluorescence decay curves in stained malignant and normal breast tissue. These results confirm that somatostatin receptors occur on human breast carcinomas, suggest that the presence of somatostatin receptors should be investigated as a marker of breast cancer aggressiveness, and suggest that this conjugate might be used to detect the presence of residual breast cancer after surgery, allowing better assessment of tumor margins and reducing the need for second or repeat biopsies in selected patients. These results may also provide clues for designing future treatment options for breast cancer patients.

Research paper thumbnail of Brain metastasis detection by resonant Raman optical biopsy method

Proceedings of SPIE, Mar 17, 2014

Research paper thumbnail of Differences in fluorescence profiles from breast cancer tissues due to changes in relative tryptophan content via energy transfer: tryptophan content correlates with histologic grade and tumor size but not with lymph node metastases

Journal of Biomedical Optics, Dec 18, 2014

The correlation between histologic grade, an increasingly important measure of prognosis for pati... more The correlation between histologic grade, an increasingly important measure of prognosis for patients with breast cancer, and tryptophan levels from tissues of 15 breast carcinoma patients was investigated. Changes in the relative content of key native organic biomolecule tryptophan were seen from the fluorescence spectra of cancerous and paired normal tissues with excitation wavelengths of 280 and 300 nm. Due to a large spectral overlap and matching excitation-emission spectra, fluorescence resonance energy transfer from tryptophan-donor to reduced nicotinamide adenine dinucleotides-acceptor was noted. We used the ratios of fluorescence intensities at their spectral emission peaks, or spectral fingerprint peaks, at 340, 440, and 460 nm. Higher ratios correlated strongly with high histologic grade, while lower-grade tumors had low ratios. Large tumor size also correlated with high ratios, while the number of lymph node metastases, a major factor in staging, was not correlated with tryptophan levels. High histologic grade correlates strongly with increased content of tryptophan in breast cancer tissues and suggests that measurement of tryptophan content may be useful as a part of the evaluation of these patients.