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Biomedical subjects

M M Moore

Publications and source records attributed to M M Moore.

At least 37 records · Page 2Linked to original sources
PubMed2000

Direct control of a computer from the human central nervous system.

We describe an invasive alternative to externally applied brain-computer interface (BCI) devices. This system requires implantation of a special electrode into the outer layers of the human neocortex. The recorded signals are transmitted to a nearby receiver and processed to drive a cursor on a computer monitor in front of the patient. Our present patient has learned to control the cursor for the production of synthetic speech and typing.

Biofeedback, Psychology↗
PubMed2000

Prevention of mechanical stretch-induced endothelial and smooth muscle cell injury in experimental vein grafts.

Vein grafts are subject to increased tensile stress due to exposure to arterial blood pressure, which has been hypothesized to induce endothelial cell (EC) and smooth muscle cell (SMC) injury. This study was designed to verify this hypothesis and to develop a tissue engineering approach that can be used to prevent these pathological events. Two experimental models were created in rats to achieve these goals: (1) a nonengineered vein graft with increased tensile stress, which was created by grafting a jugular vein into the abdominal aorta using a conventional end-to-end anastomotic technique; and (2) an engineered vein graft with reduced tensile stress, which was created by restricting a vein graft into a cylindrical sheath constructed using a polytetrafluoroethylene membrane. The integrity of ECs in these models was examined by using a silver nitrate staining method, and the integrity of SMCs was assessed by using a fluorescein phalloidin-labeling technique. It was found that nonengineered vein grafts were associated with early EC denudation with a change in EC coverage from 100 percent in normal jugular veins to 36 +/- 10, 28 +/- 12, 18 +/- 9, 44 +/- 15, 80 +/- 13, and 97 +/- 6 percent at 1 and 6 hours and 1, 5, 10, and 30 days, respectively. Similarly, rapid SMC actin filament degradation was found during the early period with a change in SMC coverage from approximately 94 percent in normal jugular veins to 80 +/- 10, 41 +/- 17, 25 +/- 9, 51 +/- 15, 79 +/- 15, 98 +/- 2 percent at 1 and 6 hours and 1, 5, 10, and 30 days, respectively, in nonengineered vein grafts. In engineered vein grafts with reduced tensile stress, EC denudation and SMC actin filament degradation were prevented significantly. These results suggested that mechanical stretch due to increased tensile stress contributed to EC and SMC injury in experimental vein grafts, and these pathological events could be partially prevented when tensile stress was reduced by using a biomechanical engineering approach.

Anastomosis, Surgical↗
PubMed2000

Adhesion of Aspergillus species to extracellular matrix proteins: evidence for involvement of negatively charged carbohydrates on the conidial surface.

Invasive lung disease caused by Aspergillus species is a potentially fatal infection in immunocompromised patients. The adhesion of Aspergillus fumigatus conidia to proteins in the basal lamina is thought to be an initial step in the development of invasive aspergillosis. The purpose of this study was to determine the mechanism of adhesion of A. fumigatus conidiospores to basal-lamina proteins and to determine whether conidia possess unique adhesins which allow them to colonize the host. We compared conidia from different Aspergillus species for the ability to bind to purified fibronectin and intact basal lamina. Adhesion assays using immobilized fibronectin or type II pneumocyte-derived basal lamina showed that A. fumigatus conidia bound significantly better than those of other Aspergillus species to both fibronectin and intact basal lamina. Neither desialylation nor complete deglycosylation of fibronectin decreased the binding of A. fumigatus conidia to fibronectin, suggesting that oligosaccharides on fibronectin were not involved in conidiospore binding. Further evidence for this hypothesis came from experiments using purified fragments of fibronectin; A. fumigatus conidia preferentially bound to the nonglycosylated 40-kDa fragment which contains the glycosaminoglycan (GAG) binding domain. Negatively charged carbohydrates, including dextran sulfate and heparin, as well as high-ionic-strength buffers, inhibited binding of A. fumigatus conidia to both fibronectin and intact basal lamina, suggesting that negatively charged carbohydrates on the surface of the conidium may bind to the GAG binding domain of fibronectin and other basal-lamina proteins. These data provide evidence for a novel mechanism of conidial attachment whereby adherence to fibronectin and other basal-lamina proteins is mediated via negatively charged carbohydrates on the conidial surface.

Aspergillus↗
PubMed2000

Apparent ipsilateral decrease in breast size at mammography: a sign of infiltrating lobular carcinoma.

PURPOSE: To assess if infiltrating lobular carcinoma (ILC) is associated with an ipsilateral mammographic decrease in breast size. MATERIALS AND METHODS: Mammographic change in size was evaluated by measuring the distance from the nipple to the pectoralis major muscle on the mediolateral oblique view of the diagnostic mammogram and on a preceding mammogram in 30 patients with ILC. Clinical, mammographic, and histopathologic findings were retrospectively reviewed. RESULTS: Five patients (17%) had an ipsilateral decrease in mammographic size. No patients noticed a physical decrease in breast size. Patients with an ipsilateral decrease in mammographic size most commonly had breast thickening at examination (four of five patients [80%], P < .001) and either a focal asymmetry density (three of five patients [60%]) or architectural distortion (one of five patients [20%]) at mammography; those patients with no change in size most commonly had a palpable mass (six of 25 patients [24%]) or normal findings (19 of 25 patients [76%]) and a mass (13 of 25 patients [52%]) at mammography. The mean tumor size was 66 mm for those with an ipsilateral size decrease and 16 mm for those with no size decrease (P < .001). At histologic analysis, tumors associated with an ipsilateral decrease in mammographic size had more diffuse involvement of the breast, and discrete masses were not seen. CONCLUSION: An apparent decrease in mammographic size may help identify cases of ILC, especially when associated with thickening at clinical examination and focal asymmetric density at mammography.

Adult↗
PubMed2000

Mutagenicity of trichloroethylene and its metabolites: implications for the risk assessment of trichloroethylene.

This article addresses the evidence that trichloroethylene (TCE) or its metabolites might mediate tumor formation via a mutagenic mode of action. We review and draw conclusions from the published mutagenicity and genotoxicity information for TCE and its metabolites, chloral hydrate (CH), dichloroacetic acid (DCA), trichloroacetic acid (TCA), trichloroethanol, S-(1, 2-dichlorovinyl)-l-cysteine (DCVC), and S-(1, 2-dichlorovinyl) glutathione (DCVG). The new U.S. Environmental Protection Agency proposed Cancer Risk Assessment Guidelines provide for an assessment of the key events involved in the development of specific tumors. Consistent with this thinking, we provide a new and general strategy for interpreting genotoxicity data that goes beyond a simple determination that the chemical is or is not genotoxic. For TCE, we conclude that the weight of the evidence argues that chemically induced mutation is unlikely to be a key event in the induction of human tumors that might be caused by TCE itself (as the parent compound) and its metabolites, CH, DCA, and TCA. This conclusion derives primarily from the fact that these chemicals require very high doses to be genotoxic. There is not enough information to draw any conclusions for trichloroethanol and the two trichloroethylene conjugates, DCVC and DCVG. There is some evidence that DCVC is a more potent mutagen than CH, DCA, or TCA. Unfortunately, definitive conclusions as to whether TCE will induce tumors in humans via a mutagenic mode of action cannot be drawn from the available information. More research, including the development and use of new techniques, is required before it is possible to make a definitive assessment as to whether chemically induced mutation is a key event in any human tumors resulting from exposure to TCE.

Animals↗
PubMed2000

Diagnosis of acromegaly in orofacial pain: two case reports.

Acromegaly is an uncommon condition, with an annual incidence in the UK of three per million. The gradual onset of the clinical features mean that often friends and relatives are unaware of the underlying pathology. In view of the morbidity, and indeed mortality, arising from undiagnosed cases, general dental practitioners and other healthcare workers should routinely take note of systemic as well as intra-oral changes occurring in their patients when seen on review. The association of paraesthesia, anaesthesia and pain with acromegaly is well documented. However, there appear to be few reports linking acromegaly with orofacial pain or dysaesthesia. This paper describes two such cases.

Acromegaly↗
PubMed2000

Allergy to a common component of resin-bonding systems: a case report.

Allergies to materials routinely used in dentistry are becoming more prevalent. The hydrophilic resin 2-hydroxyethyl methacrylate is a common constituent of systems designed to bond resin-based restorative materials to dentine. It has been considered to have a high sensitizing potential, although dental patient-related allergies to the resin appear to be rare. This report presents details of a patient who has such an allergy, which, it is suspected, manifested as an intra-oral lichenoid reaction to the closely approximating anterior restorations.

Aged↗
PubMed1999

Effects of arsenic exposure on the frequency of HPRT-mutant lymphocytes in a population of copper roasters in Antofagasta, Chile: a pilot study.

A pilot biomarker study was conducted to investigate the feasibility of using the hypoxanthine guanine phosphoribosyltransferase (HPRT) gene in peripheral blood lymphocytes as a biomarker for detecting genetic effects of arsenic exposure. Blood and urine samples were obtained from workers highly exposed to arsenic in a copper roasting plant in Antofagasta, Chile. Individuals were classified according to their job titles into three potential exposure groups: high, medium, and low. To confirm exposure, arsenic concentration was determined in urine samples. The HPRT mutant frequencies were measured in lymphocytes from 15 individuals ranging in age from 24 to 66 years. The mean mutant frequencies for the three exposure groups were: low (9 x 10(-6)), medium (11 x 10(-6)), and high (24 x 10(-6)). An increased mutant frequency was observed in the highly exposed group, but the response was so slight that it is not likely that this assay will be capable of providing dose-response information across a range of lower, more typical environmental arsenic levels.

Aged↗
PubMed1999

Long-term consequences following conservative management of epithelial ovarian cancer in an infertile patient.

A 35-year-old woman with primary infertility underwent an ovarian cystectomy for a 5 x 4 cm left adnexal mass. There was no macroscopic evidence of metastatic disease. The final pathology report revealed a poorly differentiated serous cystadenocarcinoma. Because the patient desired to retain child-bearing capacity, she refused a surgical staging of her ovarian cancer. She elected to receive combination chemotherapy. This was then followed by a negative reassessment laparotomy. The patient was diagnosed with recurrent, metastatic ovarian carcinoma 10 years later.

Adult↗
PubMed1999

Optimization of pyrene oxidation by Penicillium janthinellum using response-surface methodology.

At present, there is little information on the optimization of the degradation of polycyclic aromatic hydrocarbons (PAH) by deuteromycete filamentous fungi, a reaction catalyzed by cytochrome P450 monooxygenases. We utilized response-surface methodology to determine the optimal growth conditions for the oxidation of the PAH pyrene by Penicillium janthinellum SFU403, with respect to the variables glucose concentration, nitrate concentration and bioconversion time. Models were derived for the relationship between the variables tested and the level of the pyrene oxidation products. 1-pyrenol (1-PY) and pyrenequinones (PQ). Production of 1-PY and PQ were optimized by the same glucose and nitrate concentrations: 2.5% glucose and 1.5% sodium nitrate. The optimized 1-PY and PQ bioconversion times were 71 h and 73 h respectively. These conditions improved the yield of 1-PY by fivefold and PQ were more than 100-fold higher than the baseline levels obtained in this study. The optimized PQ yield represented 95% of the initial pyrene, thus the total optimised pyrene bioconversion to 1-PY and PQ was approximately 100%. Concentrations of glucose exceeding 4.0% repressed pyrene hydroxylation. Pyrene hydroxylation occurred almost exclusively during the deceleration phase of culture growth.

Biodegradation, Environmental↗
PubMed1999

Partial prevention of monocyte and granulocyte activation in experimental vein grafts by using a biomechanical engineering approach.

Leukocytes interact with endothelial cells and contribute to the development of vascular diseases such as thrombosis and atherosclerosis. These processes are possibly influenced by mechanical factors. This study focused on the role of mechanical stretch in the activation of monocytes and granulocytes in experimental vein grafts. Two models were created by using rats: a nonengineered vein graft with increased tensile stress, which was created by grafting a jugular vein into the abdominal aorta, and an engineered vein graft with reduced tensile stress, which was created by restricting the vein graft into a cylindrical sheath constructed by using fixative-treated intestinal tissue. The density of activated monocytes and granulocytes, which attached to the endothelium, and the distribution of the intercellular adhesion molecule (ICAM)-1 in endothelial cells were examined using immunohistological assays. It was found that, in nonengineered vein grafts, the density of activated monocytes and granulocytes increased significantly compared to that in normal jugular veins at day 1, 5, 10 and 20. At each observation time, the cell density in the proximal region of the nonengineered vein grafts was significantly higher than that in the middle and distal regions, and the cell density in the distal region was significantly higher than that in the middle region. These changes were associated with ICAM-1 clustering at day 1 and 5 and focal ICAM-1 un-regulation at day 10 and 20. In engineered vein grafts, the density of activated monocytes and granulocytes decreased significantly compared to that in nonengineered vein grafts at all observation times, although it was significantly higher than that in normal jugular veins. At each observation time, the cell density in the proximal and distal regions was significantly higher than that in the middle region, but no significant difference was found between the proximal and distal regions. ICAM-1 clustering along endothelial cell borders was found at day 1 and 5, but no apparent focal ICAM-1 up-regulation was found at day 10 and 20. These results suggested that mechanical stretch due to exposure to increased tensile stress contributed to the activation of monocytes and granulocytes in experimental vein grafts, and this event could be partially prevented by reducing tensile stress using a biomechanical engineering approach.

Analysis of Variance↗
PubMed1999

Use of fibrin sealant to reduce bleeding after needle liver biopsy in an anticoagulated canine model: work in progress.

PURPOSE: Needle biopsy of the liver is a common diagnostic procedure. Although relatively safe, bleeding remains a potential complication and may occur more frequently in patients with coagulopathy. The purpose of this study was to evaluate the utility of a fibrin sealant in preventing bleeding after a 15-gauge needle biopsy of the liver in a canine model heparinized to simulate coagulopathy. MATERIALS AND METHODS: Fibrin sealant was delivered to biopsy tract sites in eight dogs anticoagulated with heparin (activated clotting time 387 seconds +/- 94) using the same sheath system that was employed to obtain the biopsy specimen. RESULTS: The results demonstrated complete hemostasis in the sealant-plugged tracts as compared to controls. Continuous bleeding was observed in none of the fibrin sealant-treated sites, compared with all of the control biopsy sites (P = .0078). CONCLUSION: These results demonstrate the high degree of efficacy of fibrin sealant delivered through a sheath system in plugging liver biopsy tracts and eliminating bleeding in a severely coagulopathic animal model. This indicates that fibrin sealant use in cutting needle biopsies can reduce major and minor complications associated with the procedure.

Animals↗
PubMed1999

Age-related brain changes associated with motor function in healthy older people.

OBJECTIVE: To identify the MRI imaging findings associated with motor changes in healthy older people. DESIGN: A cross-sectional study. SETTING: A study of neurologic function in very healthy older people, the Oregon Brain Aging Study. PARTICIPANTS: Clinical and MRI data were examined in 50 very healthy older subjects (mean age = 85.1, SD = 7.2 years). MEASUREMENTS: Clinical measures (finger tapping, hand opening and closing, steps and time to walk 30 feet and timed standing on one foot) were dependent variables in multiple regression analyses using age and the following MRI measures as independent variables: total brain volume (TBV)/intracranial volume; ventricular volume/TBV; periventricular high signal/TBV; deep high signal/TBV. RESULTS: The number of steps and the time to walk 30 feet were each associated with periventricular high signal (steps: r = .58, P < .001; time: r = .60, P < .001) and ventricular volume (steps: r = .54, P < .001; time: r = .58, P < .001). These associations remained significant after adjusting for age. None of the other clinical variables was associated with the MRI volumes. CONCLUSIONS: Gait measures were associated significantly with periventricular high signal and ventricular volume. These CNS changes contribute to the cause of these important markers of aging.

Aged↗
PubMed1999

Diagnosis of blunt rupture of the right hemidiaphragm by technetium scan.

Traumatic rupture of the diaphragm, particularly of the right hemidiaphragm, may be occult and can be difficult to diagnose if laparotomy is not required for concomitant injury. Missed or delayed diagnosis of such injuries can produce life-threatening complications, such as intestinal herniation, ischemia, and necrosis. We present a case of traumatic rupture of the right hemidiaphragm that demonstrates the typically occult nature of this injury. The majority of right-sided injuries are diagnosed during laparotomy performed for other injuries. In those patients not requiring laparotomy, the diagnosis is usually delayed because this injury seldom produces clinical or radiographic findings that are either sensitive or specific. In this case, intraperitoneal injection of technetium sulfur colloid was used to establish the diagnosis of right diaphragm rupture, and an uncomplicated repair was undertaken.

Accidents, Traffic↗