Surface T- and B-cell markers on murine lymphomas and plasmacytomas

Seven murine lymphomas and three plasmacytomas were examined for the distribution of the theta antigen, immunoglobulin determinants, the receptor for Fc portion of antigen—antibody complexes and the receptor for the third component of complement. The theta-bearing tumours lacked C3 and Fc receptors and easily detectable surface immunoglobulin. The theta-negative lymphomas, while being morphologically lymphocytic, lacked all but the Fc receptors. One of the plasmacytomas possessed clearly detectable surface immunoglobulin. All three lacked the receptors for Fc and C3.     

Immediate breast reconstruction-impact on radiation management

Breast reconstruction is an option for women undergoing modified radical mastectomy due to a diagnosis of breast cancer. In certain patients, breast reconstruction is performed by insertion of a temporary tissue expander prior to the placement of permanent breast implants. Some of these patients, following mastectomy, may require chest wall irradiation to prevent loco regional relapse. The compatibility of radiation and tissue expanders placed in the chest wall is of major concern to the radiation oncologist. Clinically undetectable changes can occur in the tissue expander during the course of radiation therapy. This can lead to radiation treatment set-up changes, variation in tissue expansion resulting in unwanted cosmesis, and deviation from the prescribed radiation dose leading to over and/or under dosing of tumor burden. At Howard University hospital, a CT scan was utilized to evaluate the status of the temporary tissue expander during radiation treatment to enable us to prevent radiation treatment related complications resulting from dosimetric discrepancies. CT images of the tissue expander were obtained through the course of treatment. To avoid a 'geographic miss' the amount of fluid injected into the tissue expander was kept constant following patient's satisfaction with the size of the breast mound. The CT scans allowed better visualization of the prosthesis and its relation to the surrounding tumor bed. This technique ensured that anatomical changes occurring during radiation treatment, if any, were minimized. Repeated dosimetry evaluations showed no changes to the prescribed dose distribution. A CT of the reconstructed breast provides an important quality control. Further studies with greater number of patients are required for confirming this impact on radiation treatment.     

Ante mortem diagnosis of human rabies using saliva samples: comparison of real time and conventional RT-PCR techniques.

BACKGROUND: Rabies is an enzootic and fatal disease and is still a major problem in developing countries. Ante mortem diagnosis in human cases is necessary for medical management of the patient and to ensure appropriate post-exposure treatment of contacts. Both conventional RT-PCR and Real time PCR (TaqMan) have been described for the detection of rabies virus RNA from saliva and tissue respectively, however to date, there have been no studies comparing conventional and real time PCR assays for detection of rabies virus nucleic acid using saliva samples for ante mortem diagnosis. OBJECTIVES: In this study, we evaluated the utility of conventional RT-PCR and SYBR Green I Real time PCR in the ante mortem diagnosis of rabies using saliva samples. STUDY DESIGN: Saliva samples collected from twenty-four patients presenting with typical clinical manifestations of rabies were tested in the two assays. RESULTS: Amongst the 24 samples tested, 21 samples (87.5%) were positive by either of the two molecular methods. Of these 21, rabies virus RNA was detected in 6/21 in the conventional RT-PCR assay while SYBR Green I Real time PCR could detect RNA in 18/21 samples. CONCLUSION: Real time PCR assay was more sensitive than conventional RT-PCR assay (sensitivity 75% versus 37%, p=0.0189). This study highlights the utility of molecular diagnostic tests in establishing ante mortem diagnosis of rabies using saliva samples within a few hours.     

Low delay rate adaptive pacemaker using FPGA embedded piezoelectric sensor

Abstract

This paper presents the hardware implementation of low delay, power-efficient, rate-adaptive dual-chamber pacemaker (RDPM) using a piezoelectric sensor. Rate adaptive pacemaker has the ability to sense the patient’s activity by means of some special sensors and it controls the pacing rate according to the patient’s activity. Ideally, there should be no delay between sensing and the subsequent pacing operation performed by the pacemaker. However, delay in the responses of various components in the circuitry produces an accumulative delay effect in any practical circuit. Physical activity and the physiological needs of the patient can be easily adapted by the rate-responsive pacemakers using a wide range of sensor information. The piezo-electric sensor recognises the pressure on human muscles because of physical activity and converts it to an electrical signal, which is received by the pulse generator of the pacemaker. When the patient is in the rest mode, the heart rate is the only parameter that is to be detected by the pacemaker. Thus, the heart rate and the physical activity both are the inevitable parameters for the design of RDPM. Performance analysis of the proposed RDPM shows a significant reduction in the delay between sensing and pacing. Device utility analysis shows that the proposed design not only requires lesser memory but also reduces the number of components on the chip. Therefore, it becomes very clear that the proposed pacemaker design will consume much lesser power.     

Persistence of varicella-zoster virus DNA in blood mononuclear cells of patients with varicella or zoster

Varicella-zoster virus (VZV) DNA was detectable by in-situ hybridization in blood mononuclear cells (MNCs) of patients with varicella or zoster for 2–56 days after the onset of a rash. VZV DNA was present in many MNCs from one acute varicella patient 2 days after the onset of the rash and was rarely found in MNCs during acute zoster, convalescent zoster, and convalescent varicella. The morphology of MNCs containing VZV was heterogenous, although most viral-DNA-containing MNCs were large monocytoid cells. Serial examination of blood MNCs from one adult with varicella revealed VZV DNA up until 8 weeks, but not 16 weeks, after the appearance of the rash; parallel studies in four zoster patients showed VZV DNA up until 3 weeks, but not later than 7 weeks after the appearance of the rash. These results indicate that MNCs become infected with VZV during the primary encounter with VZV (varicella) and during reactivation (zoster) and that infection continues for weeks after the onset of the skin rash. Furthermore, the detection of VZV DNA in blood MNCs of uncomplicated zoster patients coincides with the period during which these patients experience pain.     

Influence of hypoxia on wavelength dependence of differential pathlength and near-infrared quantification

Continuous wave near-infrared spectroscopy (NIRS) measurements of cardiac correlated changes in attenuation in the adult human head were computed using a Fourier analysis technique that eliminates the positive error bias associated with the magnitude of the Fourier coefficient. These attenuation changes were used to determine wavelength dependence of differential pathlength, DP(lambda), at four stages during progressive hypoxia (21, 17, 13 and 9% FIO2) in normal volunteers. The effects of incorporating DP(lambda) into NIRS algorithms to compute relative concentration changes and absolute concentration of oxyhaemoglobin and deoxyhaemoglobin are discussed. Because variations in DP(lambda) are restricted to wavelengths below 780 nm, absolute concentration calculations are influenced by hypoxia-induced changes while relative concentrations are unaffected. However, even accounting for changes in DP(lambda) did not allow computation of physiologically reasonable absolute concentrations of the haemoglobin species.     

The mutational spectrum of brachydactyly type C

Growth/differentiation factor-5 (GDF5), also known as cartilage-derived morphogenetic protein-1 (CDMP-1), is a secreted signaling molecule that participates in skeletal morphogenesis. Heterozygous mutations in GDF5, which maps to human chromosome 20, occur in individuals with autosomal dominant brachydactyly type C (BDC). Here we show that BDC is locus homogeneous by reporting a GDF5 frameshift mutation segregating with the phenotype in a family whose trait was initially thought to map to human chromosome 12. We also describe heterozygous mutations in nine additional probands/families with BDC and show nonpenetrance in a mutation carrier. Finally, we show that mutant GDF5 polypeptides containing missense mutations in their active domains do not efficiently form disulfide-linked dimers when expressed in vitro. These data support the hypothesis that BDC results from functional haploinsufficiency for GDF5.     

Radiation-related cytological changes in oral malignant cells

Carcinoma of the oral cavity constitutes approximately 40% of overall malignant tumours in India, with an incidence of about 56,000 cases per year. Radiation responses in oral cancer cells by cytology have not been extensively studied. 102 patients with squamous cell carcinoma of the oral cavity treated by fractionated radiotherapy were studied. Serial scrape smears were taken from each tumour before and after irradiation. The abnormal nuclear counts per 1000 malignant cells were 1.6 and 14.1(p<0.001) for micronucleation, 0.9 and 5.5 (p<0.001) for nuclear budding, 7.6 and 28.1(p<0.001) for binucleation and 2.4 and 11.7(p<0.001) for multinucleation respectively. The study showed a significant rise in radiation induced cytological responses. In addition, radiation changes observed included abnormal and incomplete divisions of a nucleus, fibroblast like appearance cells, and enlargement of nuclear size as well as cytoplasmic granulation. These changes may have an important role to play in understanding the mechanism of cell killing after radiotherapy.     

Fast Adaptive Unsharp Masking with Programmable Mediaprocessors

Unsharp masking is a widely used image-enhancement method in medical imaging. Hardware-based solutions can be developed to support high computational demand for unsharp masking, but they suffer from limited flexibility. Software solutions can easily incorporate new features and modify key parameters, such as filtering kernel size, but they have not been able to meet the fast computing requirement. Modern programmable mediaprocessors can meet both fast computing and flexibility requirements, which will benefit medical image computing. In this article, we present fast adaptive unsharp masking on two leading mediaprocessors or high-end digital signal processors, Hitachi/Equator Technologies MAP-CA and Texas Instruments TMS320C64x. For a 2k × 2k 16-bit image, our adaptive unsharp masking with a 201 × 201 boxcar kernel takes 225 ms on a 300-MHz MAP-CA and 74 ms on a 600-MHz TMS320C64x. This fast unsharp masking enables technologists and/or physicians to adjust parameters interactively for optimal quality assurance and image viewing.     

Standardization for image characteristics in telemammography using genetic and nonlinear algorithms

As the soft copy reading and computer assisted diagnosis (CAD) in mammography become more and more important, the standardization of digital images becomes paramount. Telemammography and telemedicine requires the standardization for image characteristics, such as image resolution, bit-depth and intensity response. Soft copy reading and CAD in mammography are both dependent on the characteristics of the source of the digital data, either direct digital mammography or digitized screen-film mammography. An algorithm developed on images from one database may not perform well as on images from another database (with a different digitization). In this paper, we describe two methods based on a genetic algorithm and a nonlinear algorithm for standardization of digitized and digital mammography. The proposed standardization techniques are based on geometric and intensity transformations that are discovered using a set of calibration images. A set of transformation algorithm is used to search for the best standardization.