Can Component Size in Total Knee Arthroplasty Be Predicted Preoperatively?-An Analysis of Patient Characteristics.

Accurately predicting component sizing in total knee arthroplasty (TKA) can ensure appropriate implants are readily available, avoiding complications from malsizing while also reducing cost by improving workflow efficiency through a reduction in instrumentation. This study investigated the utility of demographic variables to reliably predict TKA component sizes. A retrospective chart review of 337 patients undergoing primary TKA was performed.

The Risk of a Deep Infection Associated With Intraarticular Injections Before a Total Knee Arthroplasty.

The aim of the study is to identify the risks associated with an intraarticular injection before a total knee arthroplasty (TKA). A total of 1628 patients were retrospectively studied over a 7-year period. The patients were divided into 2 groups: patient who received an intraarticular injection before a TKA and patients who did not receive an injection before a TKA.

Delayed peroneal nerve palsy after total knee arthroplasty--a rare complication of tibial osteolysis.

We present a case of peroneal nerve palsy which occurred 12 years after primary total knee arthroplasty as a result of extensive tibial osteolysis. The tibial osteolytic cyst extended through a cortical defect in the proximal tibia into the anterolateral compartment of the leg causing compressive neuropathy of the peroneal nerve. Imaging included radiographs, CT scan and MRI.

RNA expression profiles from blood for the diagnosis of stroke and its causes.

A blood test to detect stroke and its causes would be particularly useful in babies, young children, and patients in intensive care units and for emergencies when imaging is difficult to obtain or is unavailable. Whole genome microarrays were used to show specific gene expression profiles in rats 24 hours after ischemic and hemorrhagic stroke, hypoxia, and hypoglycemia. These proof-of-principle studies revealed that groups of genes (called gene profiles) can distinguish ischemic stroke patients from controls within 3 to 24 hours after the strokes.

Molecular markers and mechanisms of stroke: RNA studies of blood in animals and humans.

Whole genome expression microarrays can be used to study gene expression in blood, which comes in part from leukocytes, immature platelets, and red blood cells. Since these cells are important in the pathogenesis of stroke, RNA provides an index of these cellular responses to stroke. Our studies in rats have shown specific gene expression changes 24  hours after ischemic stroke, hemorrhage, status epilepticus, hypoxia, hypoglycemia, global ischemia, and following brief focal ischemia that simulated transient ischemic attacks in humans.

White matter integrity and cortical metabolic associations in aging and dementia.

Background: Studies show that white matter hyperintensities, regardless of location, primarily affect frontal lobe metabolism and function. This report investigated how regional white matter integrity (measured as fractional anisotropy [FA]) relates to brain metabolism, to unravel the complex relationship between white matter changes and brain metabolism.

Objective: To elucidate the relationship between white matter integrity and gray matter metabolism using diffusion tensor imaging and fluorodeoxyglucose-positron emission tomography in a cohort of 16 subjects ranging from normal to demented (age, >55 years).

An inverse association of cardiovascular risk and frontal lobe glucose metabolism.

Objective: To investigate associations between vascular risk profile and cerebral glucose metabolism.

Methods: Subjects ranged from normal to having dementia (age >55 years) and underwent neuropsychological testing, MRI, and FDG PET scanning (n = 58). The Framingham Cardiovascular Risk Profile (FCRP) and its individual components were used as covariates in regression analyses with each PET scan using SPM2.

Cognitive and anatomic contributions of metabolic decline in Alzheimer disease and cerebrovascular disease.

Background: Alzheimer disease and cerebrovascular disease affect elderly persons through alterations in brain structure and metabolism that produce cognitive decline. Understanding how each disease contributes to dementia is essential from both a pathophysiologic and diagnostic perspective.

Objective: To elucidate how baseline cognitive function (episodic memory and executive function) and brain anatomy (white matter hyperintensities and hippocampal volume) are associated with baseline (positron emission tomography-1 [PET1]) and longitudinal (PET2) glucose metabolism in 38 subjects older than 55 years ranging from normal cognition, cognitive impairment without dementia, and dementia.

Evidence that plasmalogen is protective against oxidative stress in the rat brain.

The antioxidant capabilities of phosphatidylethanolamine plasmalogen (PlsEtn), in vivo, against lipid peroxidation were investigated via acute phosphine (PH(3)) administration in rats. Oxidative stress was assessed from measures of malondialdehyde and various enzyme activities, while NMR analyses of lipid and aqueous tissue extracts provided metabolic information in cerebellum, brainstem, and cortex. Brainstem had the highest basal [PlsEtn], and showed only moderate PH(3)-induced oxidative damage with no loss of ATP.

Brain imaging evidence of preclinical Alzheimer's disease in normal aging.

Objective: This study was designed to test the hypothesis that baseline glucose metabolism and medial temporal lobe brain volumes are predictive of cognitive decline in normal older people.

Methods: We performed positron emission tomography using [18F]fluorodeoxyglucose and structural magnetic resonance imaging at baseline in 60 cognitively normal community-dwelling older subjects who were part of a longitudinal cohort study. Subjects were followed for a mean of 3.

The effect of duration of macular detachment on results after the scleral buckle repair of primary, macula-off retinal detachments.

Purpose: To present a current series that determined the effect of duration of macular detachment (DMD) and patient age on postscleral buckle (SB) visual acuity (VA) and anatomic results.

Design: Retrospective, noncomparative, observational case series.

Participants: Ninety-four consecutive patients (94 eyes) with primary, uncomplicated, macula-off retinal detachments, a preoperative VA of 20/200 or worse, and a precise history of when macular function was lost.

External versus internal approach to the removal of metallic intraocular foreign bodies.

Objective: To review the management of metallic intraocular foreign bodies (IOFB) at a single institution and to compare the use of internal and external approaches for their removal.

Subjects And Methods: A retrospective review was conducted on 70 eyes from 70 patients who underwent surgical removal of a metallic IOFB with either an internal (vitrectomy followed by forceps or internal magnet use) or external approach (large electromagnet) by seven vitreoretinal surgeons at a single institution between 1973 and 1996. Visual acuity and complications occurring with the two approaches were the main outcome measures studied.

Delineation of the border zone of ischemic rabbit myocardium by a technetium-labeled nitroimidazole.

Delineation of viable ischemic myocardium is an important problem in nuclear cardiology. To determine the feasibility of using a technetium-labeled nitroimidazole as an indicator of ischemic myocardium at risk of infarction, we characterized the distribution of a 2-nitroimidazole-derivatized PnAO ligand and its 99mTc complex, 99mTcO(PnAO)-1-CH2-(2NI) (BMS-181321) in the ischemic territory of the left anterior descending (LAD) coronary artery of the rabbit. In preliminary experiments, the performance of 14C-deoxyglucose (14C-2DG) and 14C-misonidazole was assessed relative to apparent regional relative myocardial blood flow (rMBF) indicated by 99mTc-teboroxime using double-label autoradiography in the rabbit LAD occlusion model.

Myocardial kinetics of a putative hypoxic tissue marker, 99mTc-labeled nitroimidazole (BMS-181321), after regional ischemia and reperfusion.

Background: A new nitroimidazole complex, 99mTc-propylene amine oxime-1,2-nitroimidazole (BMS-181321), has been developed to allow the positive imaging of hypoxic myocardium by standard gamma camera techniques.

Methods And Results: To determine the myocardial kinetics of BMS-181321 during myocardial ischemia and reperfusion, seven open-chest swine were prepared according to a model of extracorporeal coronary perfusion in which left ventricular wall thickening (percent end-diastolic thickness) and substrate use in the left anterior descending (LAD) region ([14C]palmitate and [3H]glucose infusions) were determined. Measurements were obtained at baseline, during 40 minutes of ischemia produced by reducing flow in the LAD distribution by 60%, and during 70 minutes of reperfusion.

SPECT imaging of ischemic myocardium using a technetium-99m-nitroimidazole ligand.

Unlabelled: This investigation evaluates the efficacy of a 99mTc-labeled nitroimidazole (BMS-181321) in identifying oxygen-deprived tissue in two canine models of myocardial ischemia.

Methods: For both models (A and B), epicardial microvascular oxygen pressure (mPO2) was monitored by measuring the oxygen-dependent quenching of phosphorescence lifetime of Palladium mesotetra (4-carboxyphenyl) porphine. In Model A (beagles, n = 5), BMS-181321 was administered intravenously and a distal branch of the left anterior descending coronary artery (LAD) was ligated completely 40 sec later.

BATO complexes derived from dimethoxy dioximes: synthesis, characterization and biodistribution.

To prepare less lipophilic BATO complexes, two new methoxy-substituted dioximes were synthesized: cis-4,5-dimethoxycyclohexane-1,2-dione dioxime (DMCDO) and 1,4-dimethoxybutane-2,3-dione dioxime (DMDMG). 99mTcCl(DMCDO)3BMe (BMe = methylboronic acid) was prepared and characterized. Reversed-phase HPLC analyses of 99mTcCl(DMCDO)3BMe and 99mTcCl(DMCDO)3-p-TBA (p-TBA = p - tolylboronic acid) indicated that both of these complexes were mixtures of four enantiomeric pairs of diastereomers.

Imaging ischemic tissue at risk of infarction during stroke.

Autoradiograms obtained after middle cerebral artery occlusion (MCAO) in spontaneously hypertensive rats show that the 99mTc complex of a 2-nitroimidazole-derivatized propylene amine oxime (BMS-181321) is selectively retained in acutely ischemic brain before disruption of the blood-brain barrier (BBB), but not in the ischemic infarct. BMS-181321 is therefore a marker of ischemic tissue at risk of infarction and its uptake, unlike that of x-ray and magnetic resonance contrast agents, does not require disruption of the BBB. In keeping with this conclusion, we have found that the single-pass cerebral extraction fraction of BMS-181321 is 0.

The single-pass cerebral extraction and capillary permeability-surface area product of several putative cerebral blood flow imaging agents.

We have determined cerebral blood flow (CBF) and the single-pass cerebral extraction (E) of several putative agents for external imaging of CBF. Simultaneous measurements of blood flow and extraction were performed in 106 rats. For all agents, comparison of linear and exponential regressions of E on CBF indicates that this relationship can be described as linear over the range of flows studied.

Measurement of myocardial blood flow using a co-injection technique for technetium-99m-teboroxime, technetium-96-sestamibi and thallium-201.

We have compared apparent myocardial blood flow (MBFapparent) indicated by 99mTc-teboroxime, 96Tc-sestamibi and 201TI to true MBF indicated by radiolabeled microscopheres using a technique for the co-injection of four radionuclides in the same animal. Studies were performed using rats in a single-pass model to obtain global MBF and using dogs in a multiple-pass model to determine regional MBF. To provide a wide range of MBF, adenosine was administered intravenously and the left anterior descending coronary artery was then ligated in the dogs, or hypercapnia was induced by decreasing respiratory frequency in the rats.

'Depletion' of ATP by 2-deoxyglucose: secretion by electroporated human neutrophils is not restored by readdition of ATP.

Studies of intracellular signal transduction are facilitated by the use of permeabilized cell systems, which permit the ready manipulation of the cytosol. These model systems have helped to define the roles that small solutes, particularly Ca2+ and nucleotides, play in stimulus-response coupling. In circumstances where the full depletion of intracellular ATP contents is required, some investigators have resorted to prior treatment with metabolic toxins, with the expectation that the role of ATP in signal transduction could then be more unambiguously studied.

Dual effects of guanosine 5'-[gamma-thio]triphosphate on secretion by electroporated human neutrophils.

It is generally believed that G-proteins play stimulatory roles on cell activation. In contrast, we found that guanosine 5'-[gamma-thio]triphosphate (GTP[S]) was a potent inhibitor of Ca(2+)-induced secretion from specific granules (as monitored by vitamin B-12-binding protein). GTP[S] inhibition of specific-granule release occurred in the presence or absence of adenine nucleotides, required Mg2+ (1-3 mM), and was half-maximal at 30 microM-GTP[S].

Cyclic AMP inhibits secretion from electroporated human neutrophils.

It has long been known that intracellular cAMP inhibits and cGMP enhances intact neutrophil function. However, these effects are modest and require relatively high concentrations of the cyclic nucleotides. We decided to re-examine the effects of cyclic nucleotides on Ca2(+)-induced secretion by electroporated cells.