Robot-assisted catheter manipulation for intracardiac navigation

Objective  Manual navigation of intracardiac steerable catheters is inaccurate, requires dexterity for efficient manipulation of the catheter, and exposes the interventionalist to ionizing radiation. The objective of this research is to develop a system that replaces the interventionalists’s hands in catheter manipulation for accurate and semi-automatic tele-navigation of catheters. Methods  Based on a proposed kinematic model for the distal shaft of the catheter, a system has been developed for assisted navigation of intracardiac catheters. When the distal shaft of the catheter lies inside a cardiac chamber, a robotic apparatus is utilized for automatic steering of the catheter tip to reach designated targets within the chamber. Results  The catheter modeling was validated through the experiments on three swine. The robotic system could navigate the catheter tip to designated targets with a mean distance of 6.53 mm from the target. Conclusion  Preliminary in vivo studies demonstrate the feasible application of the system in catheter navigation and the validity of catheter modeling and control strategies.     

Intravenous administration of human umbilical cord blood reduces neurological deficit in the rat after traumatic brain injury

We measured the effect of treatment of traumatic brain injury (TBI) in the rat with human umbilical cord blood (HUCB) administered i.v.. HUCB cells were injected into the tail vein 24 h after TBI and the rats were sacrificed at day 28 after the treatment. The Rotarod test and the neurological severity score (NSS) were used to evaluate neurological function. The distribution of the donor cells in the brain, heart, lung, kidney, liver, spleen, bone marrow, and muscle were analyzed in recipient rats using immunohistochemical staining and laser confocal microscopy. HUCB cells injected i.v. significantly reduced motor and neurological deficits compared with control groups by day 28 after the treatment. The cells preferentially entered the brain and migrated into the parenchyma of the injured brain and expressed the neuronal markers, NeuN and MAP-2, and the astrocytic marker, GFAP. Some HUCB cells integrated into the vascular walls within the boundary zone of the injured area. Our data suggest that i.v. administration of HUCB may be useful in the treatment of TBI.     

Active amino acids of the Kell blood group protein and model of the ectodomain based on the structure of neutral endopeptidase 24.11

In addition to its importance in transfusion, Kell protein is a member of the M13 family of zinc endopeptidases and functions as an endothelin-3-converting enzyme. To obtain information on the structure of Kell protein we built a model based on the crystal structure of the ectodomain of neutral endopeptidase 24.11 (NEP). Similar to NEP, the Kell protein has 2 globular domains consisting mostly of alpha-helical segments. The domain situated closest to the membrane contains both the N- and C-terminal sequences and the enzyme-active site. The outer domain contains all of the amino acids whose substitutions lead to different Kell blood group phenotypes. In the model, the zinc peptidase inhibitor, phosphoramidon, was docked in the active site. Site-directed mutagenesis of amino acids in the active site was performed and the enzymatic activities of expressed mutant Kell proteins analyzed and compared with NEP. Our studies indicate that Kell and NEP use the same homologous amino acids in the coordination of zinc and in peptide hydrolysis. However, Kell uses different amino acids than NEP in substrate binding and appears to have more flexibility in the composition of amino acids allowed in the active site.     

Dural arteriovenous malformations of the skull base

Dural arteriovenous malformations (AVMs) are interesting lesions, which can present as diagnostic and therapeutic challenges. Such AVMs were initially described as located solely in the dural venous sinuses, but during the last decade researchers have discovered them in other locations such as the tentorium and foramen magnum. It is understandable that they can develop in other locations because numerous arteriovenous shunts normally occur all over the dura. Early reports emphasize that they are congenital; however, some investigators have proposed that they are acquired lesions arising after sinus thrombosis and trauma. They also have variable clinical features. From 1975 to 2000 we treated 400 AVMs, of which 46 were dural. Of these 46 dural AVMs, 18 could be classified as skull base AVMs. We restricted the designation of skull base AVMs to those AVMs located in the tentorium or adjacent to bones of the skull base. Two of these AVMs actually had their vascular nidus located in the bone. The common dural sinus AVMs were excluded from this category. The presenting clinical features of these skull base AVMs ranged from headache and pulsatile tinnitus to intracranial hemorrhage. They were treated by a combination of endovascular and microsurgical treatment. The majority of patients had a good clinical outcome. Skull base dural AVMs are an interesting clinical entity. Their clinical course, treatment and final outcome are variable depending on their location. They should be managed by a multidisciplinary approach.     

Dietary components and human platelet activity

Platelet hyperactivity is one of the most important factors responsible for the incidence of cardiovascular disease. There are many nutritive and non-nutritive compounds present in the diet which may affect platelet function in various ways. Recent discovery of anti-platelet factors in plants, vegetables and fruits provides a new dietary means for a long-term strategy to favorably modify human blood platelet activity. This review summarises the effects of these dietary components on human platelet function both in vitro and in vivo.     

Occupational injury proneness in Indian women: A survey in fish processing industries

A cross sectional survey was initiated to understand the frequency of occupational injury occurrence and the associated factors in the fish processing industries of western India involving 185 randomly selected women subjects. All the subjects were interviewed with the help of an interviewer-administered questionnaire to collect information regarding their personal, occupational and work related morbidity details (including details of occupational injuries). Logistic regression method was used to analyze the data in order to obtain the contribution of individual factors on occupational injuries. This study has shown that work related morbidity like blanching of hand (OR; 2.30, 95%CI; 1.12–4.74) and nature of job like grading (OR; 3.99, 95%CI; 1.41–11.27) and packing (OR; 5.68, 95%CI; 1.65–19.57) had a significant impact on injury causation. This study eventually concludes that apart from nature of job of fish processing workers occupational hazards prevailing in the work environment contribute significantly to the occurrence of work related injuries and prevention of such occupational hazards may help in protecting workers from occupational injuries also.