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Biomedical subjects

C Batich

Publications and source records attributed to C Batich.

11 recordsLinked to original sources
PubMed2006

Molecular modeling studies of the binding characteristics of phosphates to sevelamer hydrochloride--assessing a novel technique to reduce phosphates contamination.

Recent advances in the use of polymeric materials for the remediation of phosphate from aqueous systems, including biological environments, have prompted the use of computational techniques to determine which methods are feasible to model such complex systems and to model the mechanism of binding action. In particular, Sevelamer Hydrochloride (Renagel) is used as our model polymer. A relatively simple system is constructed with a dimer of Sevelamer Hydrochloride and four phosphate ions used for capture. This work reports on molecular dynamics and Monte Carlo simulations used to determine average structure, and points of intermolecular interaction, and calculate changes in volume after the successful capture of phosphate in our model. Our resulting volume changes are of the order of 20-25%, in comparison to experimental swelling measurements on similar systems, which have an average swelling of 50-60% in aqueous media.

Models, Molecular↗
PubMed2005

Detection, identification and mapping of iron anomalies in brain tissue using X-ray absorption spectroscopy.

This work describes a novel method for the detection, identification and mapping of anomalous iron compounds in mammalian brain tissue using X-ray absorption spectroscopy. We have located and identified individual iron anomalies in an avian tissue model associated with ferritin, biogenic magnetite and haemoglobin with a pixel resolution of less than 5 microm. This technique represents a breakthrough in the study of both intra- and extra-cellular iron compounds in brain tissue. The potential for high-resolution iron mapping using microfocused X-ray beams has direct application to investigations of the location and structural form of iron compounds associated with human neurodegenerative disorders--a problem which has vexed researchers for 50 years.

Absorptiometry, Photon↗
PubMed2005

In situ characterization and mapping of iron compounds in Alzheimer's disease tissue.

There is a well-established link between iron overload in the brain and pathology associated with neurodegeneration in a variety of disorders such as Alzheimer's (AD), Parkinson's (PD) and Huntington's (HD) diseases [1]. This association was first discovered in AD by Goodman in 1953 [2], where, in addition to abnormally high concentrations of iron in autopsy brain tissue, iron has also been shown to accumulate at sites of brain pathology such as senile plaques [3]. However, since this discovery, progress in understanding the origin, role and nature of iron compounds associated with neurodegeneration has been slow. Here we report, for the first time, the location and characterisation of iron compounds in human AD brain tissue sections. Iron fluorescence was mapped over a frontal-lobe tissue section from an Alzheimer's patient, and anomalous iron concentrations were identified using synchrotron X-ray absorption techniques at 5 mum spatial resolution. Concentrations of ferritin and magnetite, a magnetic iron oxide potentially indicating disrupted brain-iron metabolism, were evident. These results demonstrate a practical means of correlating iron compounds and disease pathology in-situ and have clear implications for disease pathogenesis and potential therapies.

Alzheimer Disease↗
PubMed1997

Materials used in urological devices.

The most commonly used materials in the manufacture of urological devices are discussed with respect to their application to urinary catheters, penile implants, testicular implants, artificial urinary sphincters, and urological stents. The manufacturing, physical properties, and general chemical and biological behavior of there materials are reviewed. Attention is paid to future research trends and the general condition of the field of urological device materials.

Biocompatible Materials↗
PubMed1996

In vitro measurement of silicone bleed from breast implants.

A method to measure gel bleed from intact silicone gel-filled breast implants was developed. This nondestructive technique permits accurate and reproducible serial measurements of silicone bleed from smooth wall breast implants (n=10) under simulated physiologic conditions in vitro. Gel bleed rates from new low bleed gel-filled implants and intact explants (unbarriered, low bleed, double lumen) were determined. These results demonstrate the reliability of this method to quantify silicone gel bleed and may permit a meaningful comparison of bleed rates from implants in the future.

Breast Implants↗
PubMed1990

Connective tissue repair in circumferential periodontal defects in dogs following use of a biodegradable membrane.

A biodegradable polylactic acid membrane was evaluated for its ability to enhance periodontal regeneration. In 8 Labrador dogs, circumferential defects were created around the maxillary 1st premolars. The defects were combination "1-wall vertical and horizontal". A membrane was adjusted to cover the defect on one side of the jaw, while the contralateral tooth served as control without membrane. After 3 months, healing was evaluated histologically. The results demonstrated that the amount of connective tissue repair with newly formed cementum approximated 50% of the defect height for both test and control groups. Thus, no advantage to the use of membrane was found, which is contradictory to the findings of our previous dog study using the same biodegradable membrane. The possible reasons for this difference in results are discussed relative to suggested mechanisms for membrane effects in periodontal regeneration.

Alveolar Process↗
PubMed1989

Toxic hydrolysis product from a biodegradable foam implant.

A commercially available mammary implant containing a soft polyester polyurethane foam shell has been examined for possible diamine hydrolysis products. Fourier Transform Infrared (FT-IR) analysis has shown ester and aromatic structures present in the intact foam shell. Vigorous hydrolysis conditions using NaOH have produced a mixture with large amounts of toluene diamine (TDA) present as determined by Gas Chromatography-Mass Spectrometry (GC/MS), and GC/FT-IR. There are numerous clinical reports of the degradation of this implant shell after implantation with incorporation of fragments into phagocytic cells at the implantation site. Recent reports have discussed late pain and other allergic reactions to this implant. Release of the known toxic material, TDA, is consistent with these observations and strongly suggests that an alternative material be used in this application.

Biodegradation, Environmental↗
PubMed1988

New attachment formation following controlled tissue regeneration using biodegradable membranes.

The present study evaluated the potential for reestablishment of connective tissue attachment after exclusion of the gingival connective tissue and epithelium during healing after periodontal surgery in a dog model. Buccal mucoperiosteal flaps were elevated in all four premolar regions in two dogs. The buccal bone was reduced to approximately 25% of its original level on 24 roots. Before the elevated flaps were replaced and sutured, membranes were adjusted to cover the exposed root surfaces. On eight surfaces Millipore filters were used and on eight surfaces biodegradable polylactic acid membranes were used. No membranes were placed over the remaining eight root surfaces which served as controls. After two months of healing, the animals were sacrificed and all the roots were subjected to histological analysis. In all of the roots covered with the polylactic acid membrane, newly formed cementum with inserting collagen fibers was observed and covered on the average 46% of the initial defect. Newly formed bone covered 39% of the initial defect. The roots covered by Millipore filters were characterized by significantly less new attachment and bone. In the control roots only minor new attachment was found in the bottom of the defect in some roots. The results suggest that the establishment of a connective tissue attachment is clearly favored by the placement of a polylactic acid membrane to exclude the epithelium and gingival connective tissue during healing.

Alveolectomy↗
PubMed1986

Custom-made vaginal balloons for strengthening circumvaginal musculature.

A technique for making individualized silicone rubber intravaginal balloons is described. The method entails investing alginate vaginal impressions in silicone rubber and casting a resin model which is then dipped repeatedly in a Silastic Dispersion (Dow Corning, Q7-2213). The range of forces developed by circumvaginal muscles during maximum contractions was determined to be 0.5-4 lbs. Pressure-volume relationships of the balloons showed that the pressure of filling fluid was an accurate replica of the mean pressure in the vagina.

Female↗