NISCAIR Online Periodicals Repository Collection: IJEB Vol.45(01) [January 2007]

Microrheologic dysfunctions in blood during malaria

Fri, 29 Dec 2006 22:58:59 GMT

Title: Microrheologic dysfunctions in blood during malaria

Authors: Jayavanth, Sanjay; Park, Bock Choon

Abstract: Among the Plasmodium variants that cause human malaria, vivax malaria is considered to be non-malignant. Recent research has indicated that severe vivax infection can turnout to be as pathological as falciparum. This review evidences microrheologic pathology in vivax malaria, similar to that as seen in malignant falciparum. The parasite invasion, internalization and growth in the RBC lead to membrane rigidification and progressive loss of deformability, rosetting and cytoadherence, enhanced aggregation, clumpy, non-deforming, sticky aggregates and chronic sedimentation profiles. A model that reflects the net effect of these changes is of clinical value to establish disease severity in specific malaria. In this respect an artificial neural network (ANN) model, implemented in malaria severity analysis, is discussed. Results of this model suggest that a good degree of severity classification (60 to 100%) can be achieved even with small sample size (malaria samples n=12, normal =10). With larger sample size, ANN may be very apt as microrheological model for severity analysis.

Page(s): 111-120

Development of a tele-stethoscope and its application in pediatric cardiology

Fri, 29 Dec 2006 22:58:59 GMT

Title: Development of a tele-stethoscope and its application in pediatric cardiology

Authors: Hedayioglu, F L; Mattos, S S; Moser, L; Lima, M E de

Abstract: Over the years, many attempts have been made to develop special stethoscopes for the teaching of auscultation. The objective of this article is to report on the experience with the development and implementation of an electronic stethoscope and a virtual library of cardiac sounds. There were four stages to this project: (1) the building of the prototype to acquire, filter and amplify the cardiac sounds, (2) the development of a software program to record, reproduce and visualize them, (3) the testing of the prototype in a clinical scenario, and (4) the development of an internet site, to store and display the sounds collected. The first two stages are now complete. The prototype underwent an initial evaluation in a clinical scenario within the Unit and during virtual out-patient clinical sessions. One hundred auscultations were recorded during these tests. They were reviewed and discussed on-line by a panel of experience cardiologists during the sessions. Although the sounds were considered “satisfactory” for diagnostic purposes by the cardiology team, they identified some qualitative differences in the electronic recorded auscultations, such as a higher pitch of the recorded sounds. Prospective clinical studies are now being conducted to further evaluate the interference of the electronic device in the physicians´ capability to diagnose different cardiac conditions. An internet site (www.caduceusvirtual.com.br/ auscultaped) was developed to host these cardiac auscultations. It is set as a library of cardiac sounds, catalogued by pathologies and already contains examples from auscultations of the majority of common congenital heart lesions, such as septal defects and valvar lesions.

Page(s): 86-92

Blood flow regulation in the cerebral microvasculature with an arcadal network: A numerical simulation

Fri, 29 Dec 2006 22:58:59 GMT

Title: Blood flow regulation in the cerebral microvasculature with an arcadal network: A numerical simulation

Authors: Niimi, Hideyuki; Komai, Yutaka; Yamaguchi, Saburo

Abstract: Blood flow regulation in the cerebral microvasculature with an arcadal network was investigated using a numerical simulation. A mathematical model for blood flow in the arcadal network, based on in vivo data of cat cerebral microvasculature and flow velocity was developed. The network model consists of 45 vessel segments and 25 branching points. To simulate microvascular response to blood flow, non-reactive (solid), cerebral arteriole-like, or skeletal muscle arteriole-like responses to wall shear stress were taken into account. Numerical calculation was carried out in the flow condition where the inlet (arterial) pressure was changed from 60 to 120 mmHg. Flow-rate in each efferent vessel and the mean flow-rate over all efferent vessels were evaluated for assessment of blood supply to the local area of cerebral tissue. The simulation demonstrated the wall shear stress-induced vasodilation in the arcadal network worked to maintain the blood flow at a constant level with pressure variable in a wide range. It is suggested that an individual microvessel (segment) should join in the regulatory process of flow, interacting with other microvessels (cooperative regulation).

Page(s): 41-47

Infrared spectroscopic analysis of tumor pathology

Fri, 29 Dec 2006 22:58:59 GMT

Title: Infrared spectroscopic analysis of tumor pathology

Authors: Mehrotra, Ranjana; Gupta, Alka; Kaushik, Ajeet; Prakash, Neeraj; Kandpal, Hem

Abstract: Infrared spectra of normal and malignant breast tissues were measured in the 600 cm^-1 to 4000 cm^-1 region. The measured spectroscopic features which are the spectroscopic fingerprints of the tissues contain the vital information about the malignant and normal tissues. Fourier Transform Infrared (FTIR) data on 25 cases of infiterating ductal carcinoma of breast with different grades of malignancy from patients of different age groups were analyzed. The samples were taken from the tumor sections of the tissue removed during surgery. Infrared spectra demonstrate significant spectral differences between the normal and the cancerous breast tissues. In particular changes in frequency and intensity in the spectra of protein, nucleic acid and glycogen vibrational modes as well as the band intensity ratios for lipid/proteins, protein/nucleic acids, protein/glycogen were observed. This allows to make a qualitative and semi quantitative evaluation of the changes in proliferation activity from normal to diseased tissue. It was evident that the sample to sample or patient to patient variations were small and the spectral differences between normal and diseased tissues were reproducible. The findings establish a framework for additional studies, which may enable us to establish a relation of the diseased state with its infrared spectra.

Page(s): 71-76