Harbans Singh

Laser opto-acoustic imaging of the breast : Detection of cancer angiogenesis

First clinical prototype laser optoacoustic imaging system (LOIS) for breast cancer detection was designed and fabricated using a compact Nd:YAG laser, fiberoptic light delivery system, a linear array of 12 wide-band acoustic transducers, and a data acquisition card operated by computer with original signal processing and image reconstruction code. Initially images of small absorbing spheres were recorded in the milk with optical properties resembling those of the breast at the wavelength of 1064-nm. The system was optimized for contrast, sensitivity and axial (in-depth) resolution. The small number of acoustic transducers (12), which in turn was determined by the system cost and the time of image acquisition limited the lateral resolution of the images. Clinical ex-vivo studies on radical mastectomy specimens were performed and compared with x-ray radiography, MRI and ultrasound imaging. The results of our pilot clinical studies showed pronounced opto-acoustic contrast of ~300% between breast tumors and normal breast tissues. This contrast substantially exceeds any other endogenous tissue contrast currently utilized in clinical ultrasonography, MRI and x-ray mammography. Based on literature data and our gross observations of tumor cross-sections we hypothesize that the opto-acoustic contrast results primarily from increased optical absorption in the dense microvascularity of the tumors. In patients receiving radiotherapy, tumors were found to contain enhances concentration of dense highly scattering fiberotic tissue.

Ceruloplasmin gene expression in human cancer cells.

The copper transport protein, ceruloplasmin, is suggested to have a role in cancer since it is involved in angiogenesis and neovascularization. In order to understand the role of ceruloplasmin in malignant cells, we have recently isolated and sequenced a human ceruloplasmin cDNA clone. In the present study, we have investigated the ceruloplasmin gene expression in human colon and breast cancer cell lines. The poly (A) RNA from human colon (WiDr) and human breast (MCF-7) cancer cell lines was analyzed for the presence of ceruloplasmin mRNA. The Northern blot analysis revealed the presence of a 3.7 kb band of ceruloplasmin mRNA in these cell lines. Dot blot analysis revealed that ceruloplasmin mRNA is at least three fold more abundant in tumor cells as compared to normal rat liver.

Traumatic atlanto-occipital dislocation : MRI and CT

Abstract CT and MRI were employed to help characterize an atlanto-occipital dislocation injury, providing useful information for planning surgical stabilization and directing rehabilitation.

Optoacoustic images of early cancer in forward and backward modes

Optoacoustic tomography combines advantages of pronounced optical contrast between different tissues and high resolution of ultrawide-band ultrasound imaging. Laser pulses may be effectively used to produce acoustic sources in tissue with enhanced optical absorption. Ultrasonic waves can propagate in biological tissue with minimal distortion and deliver diagnostic information to the surface of tissue, where they may be detected with temporal resolution by piezoelectric transducers. Current status of the optoacoustic tomography applied in early detection of cancerous lesions in the breast (utilizing forward mode) and in oral cavity (utilizing backward mode) is reviewed.

MRI of malignant fibrous histiocytoma of the spermatic cord.

Inguinal masses present the practitioner with an extensive differential diagnosis. This differential includes inguinal hernias, fluid collections such as hematomas and abscesses, hydrocele of the cord, varicocele, extension of a testicular tumor to the cord, and enlarged lymph nodes. Tumors originating from the spermatic cord such as leiomyosarcomas, liposarcomas, and malignant fibrous histiocytoma (MFH) are included as well. Imaging usually begins with ultrasound and less frequently with CT (1–5). This case demonstrates the role of MRI in the workup and staging of a spermatic cord mass.

Effect of Isoprinosine on Lymphocyte Proliferation and Natural Killer Cell Activity Following Thermal Injury

The effect of in vivo administration of Isoprinosine (ISO) on, i) the proliferation of splenic lymphocytes in response to the T-cell mitogen, concanavalin-A (Con-A) and, ii) the natural killer (NK) cell cytotoxicity was studied following a full skin thickness burn injury in a rat model. Administration of ISO (100 mg/kg body wt/day) twice daily, resulted in significant augmentation of the proliferative responses of lymphocytes compared to non-treated burned animals, at 7 days post injury. However, it did not effect the lymphoproliferation at 14 days post injury, the time period at which a complete suppression of lymphocyte proliferation was observed in burned non-treated animals. Also, the proliferation of lymphocytes from normal nonburned animals was not affected by treatment with ISO. ISO treatment of the burned animals resulted in a significant increase in the NK cytotoxicity compared to non-treated burned animals. As with Con-A responses, ISO administered to control nonburned animals did not have any effect on NK cell cytotoxicity. Our studies thus indicate that ISO can be a potential immunomodulator of suppressed immune function following thermal injury, particularly in patients whose lymphocyte responses to T cell mitogen Con-A are not completely suppressed.

Kinetics of lymphoproliferative responses following scald injury in a rat burn model

Splenic lymphocytes from scalded and nonscalded rats were studied for their proliferative response to phytohemagglutinin, and to allogeneic cells in a one-way mixed lymphocyte culture (MLC). A significant suppression of the proliferation of lymphocytes in both these assays was observed as early as 4 days postinjury as measured by the [3H]thymidine uptake studies. The lymphocyte response to PHA returned to normal levels by Day 21 postinjury, whereas the MLC responses continued to be suppressed. The MLC responses between nonburned and burned animals could be restored by the addition of a lymphokine-rich culture supernatant obtained from concanavalin A-activated lymphocytes from normal nonburned rats, as well as by the addition of purified human interleukin 2 (IL-2) and rat interleukin 2. However, the addition of purified human interleukin 1 and human interferon gamma (Hu-IFN-gamma) did not bring about a significant change in the proliferation of burned rat spleen cells in MLC. Cells from burned rats were also tested for the development of suppressive activity by adding splenic lymphocytes from 2-week postburn rats to an ongoing one-way MLC. The addition of lymphocytes from burned rats resulted in significant suppression (81%) of MLC responses among normal nonburned rats. The data suggest that the development of suppressor cells following burn injury along with a defect in production and/or uptake of IL-2 may be partly responsible for immune suppression following burn injury. Since the proliferative response of lymphocytes from thermally injured rats is suppressed in a similar fashion as that found in thermally injured patients, the rat appears to be a good model for the study of kinetics of immune suppression following burn injury.

Changes in the population of active rosette-forming cells: a sensitive index for mortality among thermal injury patients

Peripheral blood lymphocytes from normal and thermally injured patients were studied for their ability to form rosettes with sheep red blood cells (SRBC) by active E-rosette assay at different times postinjury. The population of active rosette forming cells (ARFC) was observed to be significantly lower (P less than 0.001) in thermal injury patients compared with the normal subjects. The age and sex of the patient did not seem to have any significant effect on the ARFC population or the total lymphocyte count. The degree of burn had a significant (P less than 0.05) effect on the ARFC population but not the total lymphocyte count during the first 10 days immediately after burn, with partial skin thickness burn patients having more ARFC compared with full skin thickness burn patients. Further analysis of the data revealed an important correlation between the per cent ARFC in peripheral blood and the survival of the patients. Patients who died from their injuries showed a continuous decline in ARFC over the period of study, whereas the patients who survived showed a gradual increase until the ARFC number returned to within the normal range. The observed differences in the ARFC population between survivors and non-survivors were apparent as early as the first 10 days postinjury. Thus, the percentage of ARFC in the total peripheral blood may be used as an index for the early identification of patients at a greater risk of mortality.

Effect of topical applications of silver sulfadiazine on the natural killer cell activity in a rat model of thermal injury.

The effect of topical application of silver sulfadiazine cream on the natural killer (NK) cell cytotoxicity was studied in a rat model of thermal injury. The rats were given a 30% total body surface area scald injury and the NK cell cytotoxicity was studied in rats at different days postinjury with or without treatment with silver sulfadiazine. The NK cell activity was observed to be significantly (P less than .0025) suppressed at day 7 postinjury in nontreated burned rats compared with control sham burned animals. Interestingly, in rats treated with silver sulfadiazine twice daily, no suppression in NK cell activity was observed. The application of base cream (without silver sulfadiazine) did not have any significant effect on the NK cell activity in burned rats. The data show that the effect of silver sulfadiazine on NK cell activity may be due to the sulfadiazine component, since the serum levels of sulfadiazine (33.7 +/- 1.9 micrograms/dL) were observed to be maximal at day 7 postinjury.

Laser optoacoustic imaging of breast cancer in vivo

A clinical prototype of the laser optoacoustic imaging system (LOIS) was employed for breast cancer detection and localization in patients with confirmed breast cancer and scheduled for radical mastectomy. The prototype LOIS used a single optical fiber for delivery of laser pulses, an arc shaped 32-element PVDF transducer array for ultrawide-band piezoelectric detection of optoacoustic signals and a single-channel data acquisition card for signal processing. The resonance ultrasound frequency of the 110 micrometers PVDF film was outside detectable range of ultrasound. Spatial resolution of the transducer array was slightly better than 1mm in radial direction and slightly worse than 1 mm in lateral direction. The system was optimized for contrast and sensitivity. Data acquisition, signal conditioning and image processing were significantly improved and optimized resulting in reduced image frame rate of 2 seconds employing 700 MHz Aphlon processor. The computer code for digital signal processing employed band-pass hyper-Gaussian filtering and denoising. An automatic recognition of the optoacoustic signal detected from the irradiated surface was implemented in order to visualize the breast surface and improve the accuracy of tumor localization. Radial back- projection algorithm was employed adopting combination of integration along spherical wavefronts and integration along planar wavefronts (as in Radon transform) for image reconstruction. The system performance was evaluated initially in breast tissue-like phantoms with embedded blood vessels. Clinical studies in breast cancer patients scheduled for surgical mastectomy were performed and compared with x-ray radiography, ultrasound and pathology reports.