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Biomedical subjects

S E Anderson

Publications and source records attributed to S E Anderson.

At least 37 records · Page 2Linked to original sources
PubMed2002

Melorheostosis of the hand with complicating bony spur formation and bursal inflammation: diagnosis and treatment.

A 37-year old woman presented with intolerable pain associated with a slowly growing mass on the dorsum of the right hand. The radiographs were characteristic of melorheostosis involving the third and fourth metacarpals, with a cortical bony projection extending from the base of the third metacarpal eroding slightly into the fourth metacarpal, associated with bursal formation. Magnetic resonance imaging (MRI) demonstrated an inflamed bursal collection adjacent to the spur. This region corresponded to the patient's severe clinical, focal pain. To our knowledge, this is the first case report in which melorheostosis of the hand has been associated with bony spur formation and complicated by an inflamed bursa.

Adult↗
PubMed2002

Protein metabolism in lactating goats subjected to the insulin clamp.

A model of Leu and protein metabolism by the mammary gland and hind leg of lactating goats was constructed and evaluated from data collected by using [15N, 1-13C]Leu kinetics measured during amino acid (AA) infusion and a hyperinsulinemic-euglycemic clamp (IC). Goats were given continuous intravenous infusions of either saline or AA (65 g/d) for 7.5 d and from d 5 to 7.5 goats were subjected to IC. Arteriovenous kinetics were monitored on d 4 and 8 by continuous infusion (8 h) of [15N, 1-13C]Leu. Milk protein yield was increased by IC (+10%) and IC +AA (+21%), whereas AA infusion had no effect. The data were used to construct model equations that describe rates of protein synthesis and degradation, and from these equations, milk and muscle net protein synthesis were described. The model was unable to describe the observed responses in milk protein synthesis. Similar to observations in the literature, net protein gain by the hind leg increased with AA, IC, and IC + AA infusion, primarily through stimulation of protein synthesis by AA. For both tissues, IC depressed Leu oxidation, but only in the absence of AA infusion. Although the IC appears to regulate the ability of the mammary gland to coordinate blood flow and Leu catabolism in support of protein synthesis, our ability to construct a precise model describing mammary protein anabolism is still limited. In contrast, the response in protein anabolism of the hind-leg tissues of these midlactation goats was predicted well by the model, which indicate that the leg tissues were more sensitive to AA supply than the mammary gland.

Amino Acids↗
PubMed2001

Validation of an outcomes instrument for tonsil and adenoid disease.

OBJECTIVE: To design and validate a disease-specific health status instrument-the Tonsil and Adenoid Health Status Instrument-for use in children with tonsil and adenoid disease. DESIGN: Prospective psychometric and clinimetric instrument validation in 3 stages. SETTINGS: A tertiary academic pediatric specialty hospital and a tertiary academic hospital, in 2 different cities. PATIENTS/OTHER PARTICIPANTS: Children with tonsil and adenoid disease presenting for evaluation and treatment (n = 224). INTERVENTION/METHOD: Prospective instrument validation. Stage 1 consisted of initial item testing, reduction, and subscale construction; stage 2, reliability and validity testing, factor analysis, and final item reduction; and stage 3, responsiveness analysis. MAIN OUTCOME MEASURES: Test-retest and internal consistency reliability; content, construct, and criterion validity; orthogonal principal components factor analysis; and response sensitivity analysis. RESULTS: Factor analysis and item analysis confirmed 6 distinct subscales measuring different constructs (aspects) of disease-specific health status that are affected by tonsil and adenoid disease: eating and swallowing, airway and breathing, infections, health care utilization, cost of care, and behavior. For each subscale, the Tonsil and Adenoid Health Status Instrument demonstrated excellent test-retest reliability (r = 0.72-0.88) and internal consistency reliability (Cronbach alpha = .73-.87). Content validity was ensured during the design process. Construct validity was demonstrated by means of convergent and divergent validity with a global quality-of-life instrument (the Child Health Questionnaire, version PF28). Criterion validity was also satisfactory. Finally, the instrument was appropriately sensitive, with high standardized response means and effect sizes. CONCLUSIONS: The Tonsil and Adenoid Health Status Instrument is a valid, reliable, and sensitive instrument with 6 distinct subscales. This instrument has significant utility for outcomes research in children with tonsil and adenoid disease.

Adenoids↗
PubMed2001

Progressive melorheostosis in the peripheral and axial skeleton with associated vascular malformations: imaging findings over three decades.

A 28-year old woman presented with Léri's disease (melorheostosis) and the rare combination of complex vascular malformations and lymphatic anomalies. Multifocal melorheostosis was segmental and unilateral, located in the left axial and peripheral skeleton, fifth thoracic vertebral body, fifth rib. left upper limb and lumbosacral spine (third lumbar body to first sacral segment). Sacral involvement was associated with spinal canal stenosis. Additionally the patient had multiple nevi and had suffered from left hemiplegia since birth. Lymphangiectasia of the mesentery and thorax led to chylothorax resistant to therapy for which the patient underwent a pleuropericardiectomy. Death ensued due to respiratory failure.

Adult↗
PubMed2001

MR Imaging of sports-related pseudotumor in children: mid femoral diaphyseal periostitis at insertion site of adductor musculature.

OBJECTIVE: The objective of this study was to review the imaging appearance of the femurs of five patients who had been referred from outside institutions after presenting with thigh pain and being given a preliminary diagnosis of primary malignant bone tumor. Typically, when making a diagnosis, physicians place emphasis on the characteristic appearances of diseases on MR imaging, but such appearances may be misleading. An awareness of the specific MR imaging pattern of stress-related partial muscle avulsion can lead to the correct diagnosis. CONCLUSION: Femoral diaphyseal periostitis after a sports injury to the adductor musculature in children has a characteristic imaging appearance. This condition can initially appear to be misleadingly aggressive. Knowledge of the findings-particularly of the findings on MR imaging-in the proper clinical setting can help physicians make the correct diagnosis and eliminate unnecessary biopsy or inappropriate treatment.

Adolescent↗
PubMed2001

Effects of smoking and abstention from smoking on fibrinogen synthesis in humans.

Cigarette smoking and hyperfibrinogenaemia are both significant risk factors for the development of cardiovascular disease. Two studies are described here which aimed to establish the metabolic mechanism responsible for the raised plasma fibrinogen concentration observed in smokers. Chronic smokers had a significantly elevated absolute rate of fibrinogen synthesis (ASR) compared with non-smokers (22.7 +/- 1.3 mg/kg per day versus 16.0 +/- 1.3 mg/kg per day; means +/- S.E.M., P < 0.01), with plasma levels of fibrinogen significantly correlated with fibrinogen synthesis (r = 0.65, P = 0.04). Unlike fibrinogen, plasma albumin concentrations were lower in smokers than in non-smokers (45 +/- 0.4 versus 47 +/- 0.7 g/l, P < 0.05), but there was no difference in rates of albumin synthesis between the two groups. Two weeks cessation from smoking by previously chronic smokers was associated with a rapid and marked fall in plasma fibrinogen concentration (from 3.06 +/- 0.11 g/l to 2.49 +/- 0.14 g/l, P < 0.001), and a significant reduction in ASR (a 33% reduction, from 24.1 +/- 1.7 to 16.1 +/- 1.0 mg/kg per day, P < 0.001). These studies suggest a primary role for increased synthesis in producing the hyperfibrinogenaemia associated with smoking. Moreover, abstention from smoking for a period of only 2 weeks induces a significant decrease in the rate of fibrinogen synthesis by the liver, with a concomitant reduction in the plasma fibrinogen concentration.

Adult↗
PubMed2000

Hypertonic perfusion inhibits intracellular Na and Ca accumulation in hypoxic myocardium.

Much evidence supports the view that hypoxic/ischemic injury is largely due to increased intracellular Ca concentration ([Ca](i)) resulting from 1) decreased intracellular pH (pH(i)), 2) stimulated Na/H exchange that increases Na uptake and thus intracellular Na (Na(i)), and 3) decreased Na gradient that decreases or reverses net Ca transport via Na/Ca exchange. The Na/H exchanger (NHE) is also stimulated by hypertonic solutions; however, hypertonic media may inhibit NHE's response to changes in pH(i) (Cala PM and Maldonado HM. J Gen Physiol 103: 1035-1054, 1994). Thus we tested the hypothesis that hypertonic perfusion attenuates acid-induced increases in Na(i) in myocardium and, thereby, decreases Ca(i) accumulation during hypoxia. Rabbit hearts were Langendorff perfused with HEPES-buffered Krebs-Henseleit solution equilibrated with 100% O(2) or 100% N(2). Hypertonic perfusion began 5 min before hypoxia or normoxic acidification (NH(4)Cl washout). Na(i), [Ca](i), pH(i), and high-energy phosphates were measured by NMR. Control solutions were 295 mosM, and hypertonic solutions were adjusted to 305, 325, or 345 mosM by addition of NaCl or sucrose. During 60 min of hypoxia (295 mosM), Na(i) rose from 22+/-1 to 100+/-10 meq/kg dry wt while [Ca](i) rose from 347+/-11 to 1,306+/-89 nM. During hypertonic hypoxic perfusion (325 mosM), increases in Na(i) and [Ca](i) were reduced by 65 and 60%, respectively (P<0.05). Hypertonic perfusion also diminished Na uptake after normoxic acidification by 87% (P<0.05). The data are consistent with the hypothesis that mild hypertonic perfusion diminishes acid-induced Na accumulation and, thereby, decreases Na/Ca exchange-mediated Ca(i) accumulation during hypoxia.

Animals↗
PubMed1999

Quantitation of blood and plasma amino acids using isotope dilution electron impact gas chromatography/mass spectrometry with U-(13)C amino acids as internal standards.

A method to quantitate blood and plasma amino acids by isotope dilution gas chromatography/mass spectrometry (GC/mS) is described. Samples were spiked with U-(13)C amino acids as internal standards and the tert-butyldimethylsilyl derivatives (tBDMS) separated by capillary column gas chromatography. Linear regression curves, generated for individual amino acids, gave correlation coefficients of 0.9999. The reproducibility of the method was assessed from the analysis of 10 replicate blood and plasma samples. For most amino acids a coefficient of variance (CV) of </=1% was obtained with the exception of aspartate which gave a value of 1.8%. This was probably due to the low concentration of this amino acid in the samples analysed. Recovery of amino acids added to plasma was between 96 and 103%. The use of electron impact ionization (EI) allows the method to be used in laboratories where only the more basic GC/mS is available and reduces the time spent on instrument maintenance. The method should prove useful in areas of work where accurate and precise amino acid concentrations are required.

Amino Acids↗
PubMed1999

Pancreatitis-induced ascitic fluid and hepatocellular dysfunction in severe acute pancreatitis.

BACKGROUND: Multiple organ failure (MOF) is the most serious complication in severe acute pancreatitis, contributing to its high mortality. It has been suggested that changes of high-energy phosphates, intracellular pH, and intracellular cation homeostasis are closely related to hepatocellular injury associated with MOF. METHODS: Phosphorus metabolites, intracellular pH (pHi), and intracellular Na+ concentration ([Na+]i) were measured in rat livers in vivo using 31P and 23Na NMR spectroscopy after deoxycholic acid (DCA)-induced pancreatitis or intraperitoneal injection (ip) of pancreatitis-induced ascitic fluid (PAF). RESULTS: Two hours after induction of DCA-pancreatitis, the liver experienced significant intracellular acidosis (pHi = 6.99 +/- 0.16) and sodium loading (75 +/- 9 mM) and a reduction in its energy state (beta-ATP/Pi = 0.2 +/- 0.03 and Pi = 164 +/- 12). Although ip injection of PAF into healthy rats did not induce systemic hypotension, the livers under these conditions also developed severe disturbances in hepatocellular ion homeostasis and depletion of its bioenergetics. The longer the abdomen was exposed to the PAF, the worse the changes were. At 3 h after ip injection of PAF, hepatic [Na+]i significantly increased (42 +/- 3 mM) along with a significant decrease in pHi (7.30 +/- 0. 03). At 6 h after ip injection of PAF, the hepatic beta-ATP/Pi ratio decreased to 0.34 +/- 0.05 and Pi increased to 97 +/- 27. CONCLUSIONS: PAF induced severe hepatocellular acidosis, rapid accumulation of hepatic intracellular sodium, impaired hepatic cytosolic phosphorylation potential, and increased hepatic utilization of ATP. These effects may account for the eventual development of liver dysfunction associated with necrotizing pancreatitis.

Acute Disease↗
PubMed1999

Na-dependent changes in intracellular Ca in spontaneously hypertensive rat hearts.

To determine whether Na/Ca exchange is altered in primary hypertension, Na-dependent changes in intracellular Ca, ([Ca]i), were measured in isolated perfused hearts from Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Intracellular Na, (Nai, mEq/kg dry wt), and [Ca]i were measured by NMR spectroscopy. Control [Ca]i was less in WKY than SHR (176 +/- 18 vs 253 +/- 21 nmol/l; mean +/- S.E., P < 0.05), whereas Nai was not significantly different. One explanation for this is that net Na/Ca exchange flux is decreased in SHR. If this hypothesis is correct, the rate of Ca uptake in SHR should be less than WKY when Na/Ca exchange is reversed by decreasing the transmembrane Na gradient. The Na gradient was reduced by decreasing extracellular Na, ([Na]o) and/or by increasing [Na]i. To increase [Na]i, Na uptake was stimulated by acidification while Na extrusion by Na/K ATPase was inhibited by K-free perfusion. Seventeen minutes after acidification, Nai had increased but was not significantly different in SHR and WKY (18.0 +/- 2.3 to 57.4 +/- 7.6 vs 20.3 +/- 0.6 to 66.5 +/- 4.8 mEq/kg dry wt, respectively). Yet [Ca]i was greater in WKY than SHR (1768 +/- 142 vs 1201 +/- 90 nmol/l; P < 0.05). [Ca]i was also measured after decreasing [Na]o from 141 to 30 mmol/l. Fifteen minutes after reducing [Na]o, [Ca]i was greater in WKY than SHR (833 +/- 119 vs 425 +/- 94 nmol/l; P < 0.05). Thus for both protocols, decreasing the transmembrane Na gradient led to increased [Ca]i in both SHR and WKY, but less increase in SHR. The results are consistent with the hypothesis that Na/Ca exchange activity is less in SHR than WKY myocardium.

Adenosine Triphosphate↗
PubMed1998

Ischemic preconditioning: effects on pH, Na and Ca in newborn rabbit hearts during Ischemia/Reperfusion.

In adult hearts, ischemic preconditioning (PC) has been shown to decrease ischemia-induced changes in intracellular pH (pHi) and [Ca] ([Ca]i) and decrease associated injury. These results are consistent with the interpretation that PC decreases the stimulus for Na uptake via Na/H exchange, thereby decreasing intracellular Na (Nai) accumulation, and thus decreasing the change in force driving Na/Ca exchange, which otherwise contributes to ischemia-induced increases in [Ca]i. Given documented age-related differences in myocardial responses to ischemia, we tested the hypothesis that in newborn hearts, PC will diminish intracellular [H], Nai, and [Ca]i during ischemia/reperfusion. NMR was used to measure pHi, Nai, [Ca]i, ATP, and PCr in isolated newborn (4-7 days) rabbit hearts Langendorff-perfused with Krebs-Henseleit solution equilibrated with 95% O2/5% CO2 at 36+/-1 degrees C. Control hearts were perfused 30 min before initiating 40 min global ischemia followed by 40 min reperfusion. PC hearts were treated the same except four 5-min intervals of ischemia each followed by 10 min of perfusion which preceded global ischemia. At end ischemia, pHi was higher in PC than control hearts (6.31+/-0.03 v 5.83+/-0.05; P<0.05). Similarly, PC diminished Nai-accumulation during ischemia and reperfusion (P<0.05). Control Nai rose from 16.2+/-2.6 to 108.8+/-10.3 (mEq/kg dry weight) and recovered to 55.2+/-10.1 and the corresponding values for PC hearts were 25.6+/-6.2, 70.0+/-7.9 and 21.9+/-5.2. PC also improved [Ca]i recovery during reperfusion (P<0.05). Control [Ca]i rose from 418+/-43 to 1100+/-78 (nm/l) and recovered to 773+/-63, whereas in PC hearts the values were 382+/-40, 852+/-136 and 371+/-45, respectively. In addition, PC decreased coronary resistance during reperfusion (P<0.05) as reflected by lower perfusion pressures under constant flow conditions (65.9+/-1.5 v 56. 1+/-4.1 mmHg at end of reperfusion). Finally, PC improved recovery of left-ventricular developed pressure (LVDP-43.8+/-12.0 v 17.2+/-3. 0% of control; P<0.05) and diminished CK release (607+/-245 v 2432+/-639 IU/g dry weight; P<0.05) during reperfusion. The results are consistent with the hypothesis.

Adenosine Triphosphate↗
PubMed1998

The analysis of cyhexatin residues in apples, pears and kiwi fruit using inductively coupled plasma mass spectrometry as an initial screen for total tin, with confirmation by gas chromatography-mass spectrometry.

Inductively coupled plasma-mass spectrometry (ICP-MS) has been used to determine concentrations of total tin in samples of apples, pears and kiwi fruit, following acid digestion. It was found that the background levels of tin in these fruits were normally below 0.06 mg/kg, which was equivalent to the target reporting limit for cyhexatin for this work of 0.2 mg/kg. The procedure was used to screen a total of 72 retail samples. Three apple samples contained tin at concentrations greater than 0.06 mg/kg. These three samples were re-analysed by a second confirmatory method using gas chromatography-mass spectrometry (GC-MS) as the determinative step. Results obtained by this method demonstrated that in fact, none of the samples contained cyhexatin residues at or above a reporting limit of 0.1 mg/kg. The use of ICP-MS as a preliminary screen substantially reduced the number of samples requiring analysis by GC-MS, thus reducing the cost of the survey (in terms of staff hours) by approximately 30%. The screening method could potentially be applied to other organometallic pesticide residues.

Chromatography, Gas↗
PubMed1998

Closing the distance.

Geriatric technicians work in the field, providing a link between care providers and rural elderly patients. In this study, the new role enhanced patient outcomes and satisfaction.

Aged↗
PubMed1997

Ethylisopropylamiloride diminishes changes in intracellular Na, Ca and pH in ischemic newborn myocardium.

Numerous studies suggest that in adult hearts myocardial ischemic injury is in part the result of proton stimulation of Na/H exchange which increases intracellular Na (Nai) and thus leads to increases in intracellular Ca concentration ( [Ca]i) due to changes in Na/Ca exchange flux. Corollary to the hypothesis, inhibition of Na/H exchange diminishes Na and Ca accumulation and improves heart function after ischemia. To test this hypothesis and its corollary in newborn hearts, NMR spectroscopy was used to measure intracellular pH (pHi), Nai, [Ca]i, and high energy phosphates in isolated, 4-7-day-old rabbit hearts, Langendorff-perfused with Krebs-Henseleit solution at pH 7.4+/-0.5 equilibrated with 95% O2/5% CO2 at 36+/-1 degrees C. Control hearts were perfused for 30 min before initiating 40 min of global ischemia followed by 40 min of reperfusion. In a second group of hearts ethylisopropylamiloride (EIPA-10 microM) was added to the perfusate 20 min before global ischemia to inhibit Na/H exchange. After 15 min ischemia, pHi in EIPA-treated hearts (6.41+/-0.04) was higher than that of the control hearts (6.20+/-0.08; P<0.05). EIPA also limited the increase in Nai and [Ca]i during ischemia and improved Nai and [Ca]i recovery during reperfusion (P<0.05). Nai (mEq/kg dry weight) rose from 18. 1+/-3.2 to 110.6+/-14.0 and recovered to 53.3+/-12.3 in the control group. The corresponding Nai values for EIPA-treated hearts were 16. 2+/-2.4, 39.6+/-9.6 and 12.6+/-3.5, respectively. In control hearts [Ca]i (nM/l) rose from 332+/-42 to 1157+/-89 and recovered to 842+/-55, whereas in EIPA-treated hearts the values were 255+/-32, 616+/-69 and 298+/-34, respectively. EIPA also preserved cellular ATP during ischemia and reperfusion and diminished inorganic phosphate during reperfusion (P<0.05). Finally, EIPA treatment improved recovery of left ventricular developed pressure (68.2+/-8.9 v 16.2+/-3.6% of control) and limited myocardial injury as indicated by decreased total creatine kinase release during reperfusion (348+/-132 v 2432+/-639 IU/g dry weight). Thus, as in adults, the results from newborn hearts are consistent with the hypothesis.

Adenosine Triphosphate↗
PubMed1997

Primary total knee arthroplasty using the Genesis Total Knee Arthroplasty System: 3- to 6-year follow-up study of 105 knees.

This prospective study analyzed data from 105 primary total knee arthroplasties performed in 90 patients using the Genesis Total Knee Arthroplasty System. The 34 men and 56 women with a mean age of 68.7 years (range, 41-86 years) were evaluated at a mean follow-up period of 4.25 years (range, 3-6 years). Fifty-five procedures (52%) used cemented femoral and tibial components, 49 (47%) used cementless femoral and cemented tibial components, and 1 (1%) used cementless femoral and tibial components. The preoperative mean pain and function scores were 50 (range, 12-79) and 41 (range, 5-80), respectively. At the most recent follow-up evaluation, the mean pain score increased to 97 (range, 67-100), and the mean function score increased to 88 (range, 40-100). Mean preoperative range of motion was 104 degrees (range, 50 degrees-130 degrees) and increased to 116 degrees (range, 80 degrees-130 degrees) at most recent follow-up evaluation. Clinically, there were 100 excellent results (95%). 4 good results (4%), and 1 poor result (1%).

Aged↗