Biomedical subjects

M J Morris

Publications and source records attributed to M J Morris.

At least 55 records · Page 3Linked to original sources

PubMed1997

Detection of interstitial lung abnormalities on picture archive and communication system video monitors.

The purpose of this study was to compare the detection of interstitial lung abnormalities on video display workstation monitors between radiologists experienced with video image interpretation and radiologists who lack this experience. Twenty-four patients with interstitial lung abnormalities documented by high-resolution computed tomography (HRCT) and lung biopsy, and 26 control patients with no history of pulmonary disease or a normal HRCT and normal chest radiographs were studied. Images were acquired using storage phosphor digital radiography and displayed on 1,640 x 2,048 pixel resolution video monitors. Five board-certified radiologists evaluated the images in a blinded and randomized manner by using a six-point presence of abnormality grading scale. Three radiologists were from 1 to 4 years out of residency and considered to be experienced workstation monitor readers with between 1 to 3 years of video monitor image interpretation. For the inexperienced readers, one radiologist had no prior experience with reading images from a video monitor and was direct out of residency, and the other radiologist had less than 4 months of intermittent exposure and was 1 year out of residency. Sensitivity and specificity were determined for individual readers. Positive predictive values, negative predictive values, accuracy, and receiver-operating curves were also generated. A comparison was made between experienced and inexperienced readers. For readers experienced with video monitor image interpretation, the sensitivity ranged from 87.5% to 92%, specificity from 69% to 92%, positive predictive value (PPV) from 73% to 87.5%, negative predictive value (NPV) from 87% to 90%, and accuracy from 80% to 88%. For inexperienced readers, these values were sensitivity 58%, specificity 50% to 65%, PPV 52% to 61%, NPV 56.5% to 63%, and accuracy 54% to 62%. Comparing image interpretation between experienced and inexperienced readers, there were statistically significant differences for sensitivity (P < .01), specificity (P < .01), PPV (P < .05), NPV (P < .05), accuracy (P < .05), and area under the receiver operator curve (Az) (P < .01). Within the respective experienced and inexperienced groups, no statistical significant differences were present. Our results show that digitally acquired chest radiographs displayed on high-resolution workstation monitors are adequate for the detection of interstitial lung abnormalities when the images are interpreted by radiologists experienced with video image interpretation. Radiologists inexperienced with video monitor image interpretation, however, cannot reliably interpret images for the detection of interstitial lung abnormalities.

Adult↗

PubMed1997

Post-exercise depression of baroreflex slowing of the heart in humans.

In normal human subjects, we tested whether a 20- to 30-min period of rhythmic exercise, intended to provoke strong activation of the sympathetic nerves, would lead to prolonged inhibition of vagally mediated bradycardia evoked reflexly by stimulation of the baroreceptors by neck suction. Negative pressure within the neck cuff (-40 to -80 mmHg) reflexly evoked a reproducible increase in pulse interval. Following exercise, this increase in pulse interval was reduced from 444 +/- 104 ms to 76 +/- 57 ms (mean +/- SEM). Recovery time was 42 +/- 9 min. These findings demonstrate a prolonged attenuation of cardiac vagal action following rhythmic exercise in normal human subjects. It is known that neuropeptide Y (NPY) is released from cardiovascular sympathetic nerves, that it attenuates cardiac vagal action and that plasma levels of NPY are elevated for a prolonged period after exercise. Therefore, it is proposed that NPY, released from sympathetic nerves during exercise, attenuates reflexly evoked cardiac vagal action for a prolonged period after exercise ends.

Adult↗

PubMed1997

Lack of effect of age on the cardiovascular response to neuropeptide Y injection in the rat nucleus tractus solitarius.

1. Neuropeptide Y (NPY) is colocalized with catecholamines in central regions involved in blood pressure regulation and exerts depressor responses in the nucleus tractus solitarius (NTS). Ageing is accompanied by a decline in baroreflex function and a reduction in NPY concentrations in some brain areas. The present study investigated whether the cardiovascular response to NPY microinjection into the NTS and medullary NPY concentrations were conserved in aged rats. 2. Neuropeptide Y (6 pmol in 100 nL) unilaterally injected into the NTS of anaesthetized 3- or 17-month-old male Sprague-Dawley rats produced a prompt 9-10% fall in mean arterial pressure (MAP), which tended to last longer in aged rats. Decreases in heart rate (HR) observed following NPY administration into the NTS were modest but more prolonged than the depressor responses. ANOVA with repeated measures demonstrated no significant effect of age on the MAP or HR response to NPY injection into the NTS. Neuropeptide Y concentrations in the dorsomedial and ventrolateral medulla were not different between the two age groups. 3. Thus, the depressor and bradycardic responses to exogenous NPY administration in the NTS were maintained with age, in keeping with the observation of similar medullary NPY concentrations in adult and aged rats.

Aging↗

PubMed1997

Region-specific neuropeptide Y overflows at rest and during sympathetic activation in humans.

Neuropeptide Y coexists with norepinephrine in sympathetic nerves and is coreleased into the circulation on sympathetic activation. Little is known about the regional release of neuropeptide Y in humans under normal conditions or in pathophysiological situations of sympathetic activation or denervation. We measured plasma neuropeptide Y-like immunoreactivity and norepinephrine concentrations in samples taken from the brachial artery; coronary sinus; and internal jugular, antecubital, or hepatic veins in volunteers aged 20 to 64 years. Regional neuropeptide Y overflow at rest was calculated from venoarterial plasma concentration differences and plasma flow, and norepinephrine spillover was determined by [3H]norepinephrine infusion techniques. Cardiac release of neuropeptide Y and norepinephrine was examined in response to various stressors as well as in clinical models of sympathetic activation, cardiac failure, and denervation after cardiac transplantation. In healthy volunteers, cardiac, forearm, and jugular venous sample neuropeptide Y concentrations were similar to arterial levels. Hepatic vein plasma neuropeptide Y was greater than arterial both at rest (119 +/- 5% of arterial, n = 7) and after a meal (132 +/- 12%, n = 7), with neuropeptide Y overflows of 6 +/- 2 and 11 +/- 2 pmol/min, respectively. In contrast, hepatomesenteric norepinephrine spillover was not significantly increased by feeding. Although coronary sinus plasma norepinephrine concentrations increased significantly with the cardiac sympathetic activation accompanying mental arithmetic, coffee drinking, isotonic exercise, and bicycle exercise, only the latter powerful sympathetic stimulus increased neuropeptide Y overflow. Cardiac failure was associated with increased resting release of both norepinephrine and neuropeptide Y from the heart, whereas postcardiac transplant norepinephrine spillover from the heart was reduced. The net overflow of neuropeptide Y to plasma observed at rest across the hepatic circulation, but not the cardiac, forearm, or cerebral circulations, indicates that the gut, the liver, or both make a major contribution to systemic plasma neuropeptide Y levels in humans. Sympathetic activation by exercise produced a modest increase in cardiac neuropeptide Y overflow but to only approximately 25% of the resting input from the gut and without a change in arterial neuropeptide Y concentration. Plasma neuropeptide Y measurements are less sensitive than those of plasma norepinephrine concentrations as an index for quantifying sympathetic neural responses regulating the systemic circulation.

Adult↗

PubMed1997

Sleep apnea-hypopnea syndrome in a sample of veterans of the Persian Gulf War.

The prevalence of sleep apnea-hypopnea syndrome (SAHS) was investigated in a selected group of veterans of the Persian Gulf War at Brooke Army Medical Center. One hundred ninety-two self-referred patients participated in the full evaluation of the Comprehensive Clinical Evaluation Program (CCEP) for veterans of the Persian Gulf War. After completing an initial survey, an interview and examination were performed by staff internists. Forty-six participants with histories suggestive of a sleep disorder were referred for further evaluation. Those patients suspected of SAHS then completed a sleep disorders questionnaire and underwent standard nocturnal polysomnography (PSG). SAHS was defined as a respiratory disturbance index > or = 15 in a symptomatic patient. Fifteen of 46 patients undergoing PSG at this institution met criteria for SAHS. The majority of these patients had symptoms of fatigue and memory loss. Overall, 16 of the 192 patients (8.3%) in the CCEP of our institution were diagnosed with SAHS. SAHS may play a significant role in the symptom complex presented by many veterans of the Persian Gulf War.

Adult↗

PubMed1996

Altered in vivo catecholamine release in the hypothalamic paraventricular nucleus of the aged rat.

The effect of age on basal and stimulated noradrenaline release in the hypothalamic paraventricular nucleus (PVN) of the rat was examined by in vivo microdialysis. Microdialysis probes were inserted into the PVN of 3 and 18 month old anaesthetised Sprague Dawley rats and perfused with a modified Ringer solution. Following four basal 30-min collections, transmitter release was stimulated by perfusion with 100 mM potassium for one collection. After re-equilibration, blood pressure was raised 60 mmHg for 30 min by phenylephrine infusion (1-1.3 mg/kg) then a 2-h recovery period followed. Dialysate collections were injected directly onto a reverse phase HPLC-ECD (HPLC with electrochemical detection). Basal extracellular noradrenaline concentrations were found to be similar in adult and old animals. Basal dihydroxyphenylacetic acid (DOPAC) concentrations were significantly greater in old compared to adult rats (P < 0.05). Potassium depolarisation induced a significant increase in noradrenaline concentrations in both age groups (P < 0.001), however the noradrenaline response to potassium stimulation was significantly reduced in the aged rats (P < 0.05). Potassium-induced decreases in DOPAC and homovanillic acid (HVA) concentrations were seen in both age groups. Following phenylephrine infusion, a modest delayed reduction in noradrenaline levels, which failed to reach statistical significance, was seen. Phenylephrine-induced hypertension was associated with decreased DOPAC and HVA concentrations in adult (P < 0.05) and old (P < 0.05) rats, respectively. These results indicate that ageing is associated with changes in dopaminergic and noradrenergic activity in the PVN of the rat. A reduction in noradrenaline response to maximal stimulation induced by potassium depolarisation was observed with ageing. The alteration in the activity of the catecholaminergic pathways to the PVN induced by phenylephrine infusion appears to be age dependent.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1996

Difference between functional residual capacity and elastic equilibrium volume in patients with chronic obstructive pulmonary disease.

BACKGROUND: A study was performed to determine the elastic equilibrium volume (Vr) of the respiratory system in patients with chronic obstructive pulmonary disease (COPD). METHODS: Voluntary relaxed expiration from total lung capacity (TLC) was studied in three groups of subjects: seven patients with severe chronic airways obstruction (COPD), 10 normal subjects, and 15 subjects with restrictive disease. RESULTS: In the normal subjects and the patients with restrictive disease voluntary relaxed expiration from TLC stopped close to end tidal volume (FRC) and the volume expired in this manoeuvre was less than that expired in a slow vital capacity manoeuvre (SVC). In the patients with COPD the voluntary relaxed expiration continued beyond the end tidal volume (FRC) and the volume expired was not different from the SVC. Oesophageal (pleural) pressures and surface diaphragmatic EMG recordings in the patients with COPD supported the premise that relaxation was achieved. CONCLUSIONS: In patients with COPD, end tidal volume (FRC) is higher than the elastic equilibrium volume, Vr, of the respiratory system. This is in contrast to patients with restrictive disease and normal subjects in whom end tidal volume (FRC) is close to Vr. This study shows that, in patients with severe chronic obstructive pulmonary disease, Vr is at least as small as residual volume (RV).

Functional Residual Capacity↗

PubMed1996

Enzyme-linked immunosorbent assay for thrombin-antithrombin III complexes in horses.

OBJECTIVES: To adapt and characterize a human ELISA kit to quantify thrombin-antithrombin III (TAT) complexes in horses, and to evaluate TAT as a marker for hypercoagulation in horses. ANIMALS: 29 clinically normal horses used as controls, and 4 ill horses used to evaluate assay for known causes of hypercoagulation. PROCEDURE: A commercially available human sandwich-type ELISA kit with 2 antibodies against human thrombin and antithrombin III that bind selectively to their corresponding TAT antigenic sites was used. Equine TAT standards were made from purified equine thrombin and antithrombin III. Proteins diluted in a phosphate-buffered saline solution containing 0.1% Tween and 1 U of heparin/ ml were used to establish standard curves. Reference intervals for TAT concentration in citrated equine plasma, and intra- and interassay coefficients of variation were determined. RESULTS: Mean +/- SD values were 3.95 +/- 1.93 micrograms/L, with median of 3.18 micrograms/L and range of 1.95 to 9.03 micrograms/ L. One horse with cecal perforation had TAT concentration of 174.30 micrograms/L, and a horse infused IV with endotoxin had TAT concentration of 62.98 micrograms/L 12 hours after infusion. CONCLUSIONS: The data suggest that human TAT ELISA kits can be used to measure TAT concentration in citrated equine plasma, and that TAT is a marker for hypercoagulation in horses. CLINICAL RELEVANCE: Assays for equine TAT many help to further characterize the hypercoagulable state in horses.

Animals↗

PubMed1995

Neuropeptide Y potentiation of potassium-induced noradrenaline release in the hypothalamic paraventricular nucleus of the rat in vivo.

NPY is co-localised with catecholamines in the brain and periphery. Noradrenaline and NPY are present in high concentrations in the PVN of the hypothalamus, an area implicated in autonomic regulation. This microdialysis study examined whether NPY can modulate rat PVN noradrenaline release in vivo, as has been shown in vitro. Basal and K(+)-stimulated noradrenaline release was measured after i.c.v. administration of 2 nmol NPY or vehicle. No effect of NPY was observed on basal release, however a significant doubling of K(+)-induced release was observed, both 60 and 150 min following i.c.v. NPY. This raises the possibility that NPY may potentiate rather than inhibit brain noradrenaline release in vivo.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1995

Forced expiratory flow is reduced by 100% oxygen in patients with chronic obstructive pulmonary disease.

In order to determine the effect of breathing high fractional concentrations of oxygen on forced expiratory flow in individuals with chronic obstructive pulmonary disease (COPD), we studied 18 patients with moderately severe disease. The patients were studied breathing air, 100% oxygen, or a four-gas mixture in a randomized double-blind study design. The four-gas mixture (oxygen 21.0%, argon 48.6%, nitrogen 19.3%, and helium 11.1%) was calculated to have a density and viscosity similar to oxygen. During spirometric testing, breathing oxygen produced a detectable reduction in timed volumes by 1 minute that was sustained at 5 minutes (FEV1 reduction 4.9% at 1 minute and 6.3% at 5 minutes). Breathing the gas mixture for 5 minutes resulted in similar reductions in flow. We conclude that high concentrations of oxygen reduce forced expiratory flow in patients with airflow obstruction, an effect probably related to the increased density and viscosity relative to air. This reduction in forced expiratory flow may contribute to the deterioration seen when COPD patients with acute respiratory failure are treated with 100% oxygen.

Aged↗

PubMed1995

Recurrent bilateral spontaneous pneumothoraces associated with pulmonary angiocentric immunoproliferative lesion.

A 28-year-old man had a left pneumothorax and diffuse reticulonodular infiltrates. He subsequently had a right pneumothorax and manifested bilateral recurrences after treatment of the initial pneumothoraces. Pulmonary angiocentric immunoproliferative lesion was diagnosed by open lung biopsy. Treatment with combination chemotherapy improved the infiltrates, but failed to prevent another pneumothorax. Etiologic considerations for the recurrent pneumothoraces are proposed.

Adult↗

PubMed1995

Analysis of tidal expiratory flow pattern in the assessment of histamine-induced bronchoconstriction.

BACKGROUND: There are times in clinical practice when it would be useful to be able to assess the severity of airways obstruction from tidal breathing. Three indices of airways obstruction derived from analysis of resting tidal expiratory flow have previously been described: (1) Tme/TE = time to reach maximum expiratory flow/expiratory time; (2) Krs = decay constant of exponential fitted to tidal expiratory flow versus time curve; and (3) EV = extrapolated volume--that is, area under the curve when the fitted exponential is extrapolated to zero flow. In this paper a further index--dtr/TE, time from the beginning of expiration till the rapid decay of flow begins/expiratory time--is evaluated. The aim of this study was to assess the ability of these indices to detect mild airways obstruction. METHODS: A histamine bronchial provocation test was performed in 20 adult patients with a diagnosis of asthma or symptoms of cough and/or shortness of breath. Baseline forced expiratory volume in one second (FEV1), functional residual capacity (FRC), and specific inspiratory conductance (sGaw) were measured and the measurements repeated after the final inhalation of histamine. Expiratory flow patterns during quiet breathing over five consecutive representative breaths were analysed before and after histamine. The test was concluded in 12 subjects when FEV1 had decreased by 20% of the post saline value, and in the remaining eight after inhalation of 16 or 32 mg/ml histamine. RESULTS: FEV1, sGaw, FRC, Krs, EV, and dtr/TE were all different after histamine (paired t test). For Tme/TE no difference was shown. Change in EV detected change in end tidal volume but underestimated it compared with the change measured by body plethysmography. Percentage fall in Krs after histamine correlated with percentage fall in FEV1 (r = 0.527, Pearson correlation coefficient). This was of a similar order to the correlation between the percentage fall in sGaw and in FEV1 (r = 0.543). CONCLUSIONS: Analysis of expiratory tidal flow-time patterns predicted a decrease in FEV1 following histamine challenge as did measurement of sGaw. This analysis of tidal breathing would be useful in circumstances where forced expiratory manoeuvres are unreliable or inapplicable.

Adult↗

PubMed1994

Catecholamine release in the rat hypothalamic paraventricular nucleus in response to haemorrhage, desipramine and potassium.

In vivo microdialysis and HPLC were used to measure catecholamine release in the rat hypothalamic paraventricular nucleus (PVN) during haemorrhage. The effects of noradrenaline uptake blockade with 1 microM desipramine (DMI) and a depolarising concentration of potassium (100 mM) through the probe were also examined. Dialysis probes implanted in the PVN of urethane anesthetised rats were perfused with modified Ringer solution at 1.1 microliter/min. Thirty minute collections were analysed for DOPA, noradrenaline, DOPAC, HVA and 5-HIAA. Basal concentrations, in the absence of DMI, were: DOPA 203.6 +/- 44.0 pg/ml, noradrenaline 128.0 +/- 20.4 pg/ml; DOPAC 5.6 +/- 0.7, HVA 5.1 +/- 2.2 and 5-HIAA 87.2 +/- 17.8 ng/ml. Basal noradrenaline was doubled in the presence of DMI while basal and stimulated DOPA, DOPAC, HVA and 5-HIAA were not affected by DMI. Haemorrhage resulted in a significant noradrenaline release (48% over resting levels) in the presence of DMI (n = 10, P < 0.05); in the absence of DMI, a smaller and non-significant increase (30% over basal levels) was observed. Potassium-induced depolarisation caused a significant two- and four-fold increase in noradrenaline release (P < 0.001), with decreases in the dopamine metabolites DOPAC (31%, 44%) and HVA (35%, 28%), and the serotonin metabolite, 5-HIAA (41%, 33%), in the presence and absence of DMI, respectively. The catecholamine precursor DOPA did not vary throughout either experiment. The results indicate that haemorrhage induces a 48% increase in noradrenaline release in the rat PVN which provides evidence for a role of noradrenergic projections to the PVN in cardiovascular control.

Animals↗

PubMed1994

Empyema thoracis: medical aspects of evaluation and treatment.

Empyema thoracis is a disease that, despite centuries of study, still causes significant morbidity and mortality. Sixty-five cases were seen at Brooke Army Medical Center over an 8-year period (March 1, 1985, through March 1, 1993). The majority of the patients were men, older than 50 years of age, with significant underlying diseases. Pneumonia remains the most common single proximate cause of empyema. Gram-positive cocci are the most frequently isolated organisms; however, empyemas due to gram-negative organisms and anaerobes are associated with higher mortality. Pleural fluid gram stains proved to be an accurate but neglected diagnostic tool in guiding initial therapy. The choice of antibiotics seemed to have no discernible impact on mortality. Closed tube thoracostomy was the initial method of drainage in most patients and had an overall success rate of 50%. Empyemas that could not be effectively drained by a single chest tube were unlikely to be drained by additional closed maneuvers. There was an overall 22% case-fatality rate with most deaths related to our inability to eradicate the empyema.

Adolescent↗

PubMed1994

Age-related changes in neuropeptide Y content in brain and peripheral tissues of spontaneously hypertensive rats.

1. This study examined neuropeptide Y (NPY) concentrations in brain regions and peripheral tissues of young (3-4 months) and old (17-18 months) normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). 2. Neuropeptide Y-like immunoreactivity (NPY-LI) was determined in kidney, adrenal, heart ventricles, atria and four brain regions, cerebral cortex, hypothalamus, ventrolateral medulla (VLM) and dorsomedial medulla containing the nucleus tractus solitarius (NTS), by radio-immunoassay following acid extraction. 3. Significant age-related increases in organ weights were observed in atria, ventricle and kidney of both WKY and SHR (P < 0.01). In order to take into account tissue hypertrophy, NPY-LI data were analysed as pmol/g tissue as well as total pmol/tissue. 4. At each age, similar NPY-LI concentrations were observed in WKY and SHR in all brain regions. A significant age-induced decrease in NPY-LI concentration and total NPY content was found in the hypothalamus of both WKY and SHR (P < 0.01). 5. In the cardiac ventricle, decreases were observed in NPY-LI concentration with ageing, and in SHR relative to WKY; however, no differences were observed in total NPY-LI content. A significant age-related increase in adrenal NPY-LI concentration was observed. No age- or strain-related alterations in atrial or renal NPY-LI were detected, with the exception of an increase in total kidney NPY-LI in WKY with ageing. 6. Thus in the periphery, few changes in NPY-LI were observed with genetic hypertension or with ageing.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗

PubMed1994

Neuropeptide Y in cortisol-induced hypertension in male volunteers.

1. Cortisol-induced blood pressure rises in men are not accompanied by increases in plasma catecholamines. The present study examines the effects of cortisol on the sympathetic co-transmitter, neuropeptide Y (NPY). 2. Eight normal men were given cortisol 200 mg/day over 5 days and haemodynamic, metabolic and hormonal measures were taken. Plasma NPY-like immunoreactivity (NPY-LI) concentrations were measured by direct radio-immunoassay. 3. Cortisol significantly increased systolic, diastolic and mean arterial pressure, bodyweight, plasma glucose and total white cell concentration and decreased plasma potassium and total eosinophil count, as in previous studies. Plasma NPY concentrations were not altered significantly during cortisol treatment, but increased following cessation of cortisol treatment (P = 0.006). 4. The essentially unchanged pattern for NPY concentration with cortisol treatment resembles that previously reported for adrenaline and noradrenaline, but the increase in NPY on cortisol withdrawal was not seen for adrenaline or noradrenaline. These data do not support a role for sympathetic activation in the genesis of cortisol-induced hypertension.

Adult↗

PubMed1994

Precompetition anxiety in women volleyball players: a test of ZOF theory in a team sport.

Consistency in psychological factors is widely regarded to be important for successful performance in team sports, but the Zone of Optimal Function (ZOF) theory contends that athletes should exhibit considerable variability in the level of anxiety that will optimize performance. In an attempt to determine if tenets of ZOF theory held for athletes in a team sport, anxiety was measured using Spielberger's state-trait anxiety inventory (STAI) at the baseline and before easy and difficult competitions in nine members of a collegiate women's volleyball team. The ability to predict precompetition anxiety was assessed by having the athletes complete the STAI both 3 weeks and 2 days before each match according to how they thought they would feel 1 h before competition. Each athlete also completed the STAI on the basis of how she recalled feeling before her best competition. Four anxiety units were added and subtracted from this value to establish the ZOF of each player. Actual precompetition anxiety was assessed 1 h before each match. In accordance with ZOF theory, considerable variability was found in the range of optimal anxiety, and 55.5% of the team members reported performing best at either low or high levels of anxiety. The prediction of precompetition anxiety made 2 days before competition was significantly correlated to actual anxiety for the difficult match (r = 0.69, P < 0.05) but not the easy match (r = 0.21, P > 0.05). Predictions made 3 weeks before competition were not significant (P > 0.05). More (P < 0.05) of the player possessed anxiety levels within the ZOF for the difficult match compared with the easy match (77.7% versus 22.2%). In summary, athletes in the team sport of volleyball exhibit considerable variation in optimal precompetition anxiety in accordance with ZOF theory. As posited by ZOF theory, the athletes were able to predict anxiety before a difficult match accurately and were more likely to have anxiety levels with ZOF.

Adolescent↗

PubMed1993

Determination of tris(hydroxymethyl)aminomethane (tromethamine) in human plasma and urine by high-performance liquid chromatography with fluorescence detection.

Determination of tromethamine (2-amino-2-hydroxymethyl-1,3-propanediol) in human plasma and urine has been developed and validated. The method utilizes reversed-phase high-performance liquid chromatographic separation and fluorescence detection of a pre-column derivative. The assay was linear in the ranges of 1-200 micrograms/ml plasma and 5-500 micrograms/ml urine with accuracies (mean percent recovery) all within 10% of 100% and precisions (coefficient of variation) all less than 10%.

Chromatography, High Pressure Liquid↗