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Thin-layer and gas-liquid chromatographic procedures for the determination of perazine and its metabolites in human body fluids.

The quantitative determination of perazine, a neuroleptic drug, and its metabolites in body fluids is difficult in view of the low concentrations to be expected under therapeutic conditions as well as of the problem of convenient detectors. Different methods for extraction and measurement of perazine concentration in blood samples are discussed, with special consideration of partition coefficients and the properties of the chromatographic systems (thin-layer and gas-liquid chromatography). A new and simple method for rapid gas chromatographic determination of perazine is presented.

Antipsychotic Agents↗

Clinical evaluation of ketone bodies in body fluids of cows in late pregnancy and their fetuses.

Ketone body concentrations were determined in six body fluids of cows in late pregnancy and their fetuses (blood plasma and urine of cows, amniotic and allantoic fetal fluids, and fetal blood serum and urine) using the head-space gas chromatographic method. Physiological ratios O/T% of oxidized (acetone and acetoacetic acid) to total (acetone, isopropanol, acetoacetic and 3-hydroxybutyric acid) ketone bodies were below 10% in cow blood plasma and urine, fetal serum and urine, and allantoic fluid, and below 20% in amniotic fluid. A scheme for the evaluation of the degree and duration of ketosis based on the O/T% ratio is proposed. The existence of a renal regulatory mechanism for excretion of ketone bodies is suggested by analogy with the renal acidobasic regulation.

Allantoin↗

Blood and body fluid exposures during clinical training: relation to knowledge of universal precautions.

To investigate the relation between knowledge of universal precautions and rates of exposure to blood and body fluid during clinical training, a cohort of 155 students was surveyed following training in universal precautions and 18 months later. A total of 127 students (82%) participated; 58 (46%) experienced at least one exposure during the first clinical training year. Knowledge of universal precautions was inversely associated with the frequency of mucous membrane exposures (p .001); an apparent "dose-response" effect was evident (one-way analysis of variance; F = 5.2, p - 0.007). Students are frequently exposed to blood and body fluid during clinical training. Higher levels of retained knowledge about universal precautions are associated with a decreased risk of mucous membrane exposure.

Health Knowledge, Attitudes, Practice↗

Melatonin assays in body fluids.

A variety of methods now exist for the assay of melatonin in body fluids. Their relative merits are compared and the validation of one in particular (RIA) described. Physiological studies of melatonin by RIA have shown probable modulation of its secretion by gonadal steroids. The circadian activity maximum in the dark phase of one of the pineal melatonin synthesizing enzymes, N-acetyltransferase, is reflected in peripheral melatonin levels. Man, like all other species studied so far, has a dark phase rise in circulating melatonin. During the menstrual cycle, melatonin shows a luteal phase rise. Further evidence of pineal rhythmicity is found in seasonal melatonin variations in man. The study of the rhythmic properties of peripheral melatonin in man may provide important information on central nervous function.

Acetyltransferases↗

Detection of bacterial antigens in body fluids by the Phadebact system.

150 infected patients from 2 study centers had body fluids examined for presence of bacterial antigens (group B streptococcus, Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b) using the Pharmacia Phadebact system. The rates of detection of the pneumococcal antigens in the urine or serum of the patients with pneumococcal pneumonia, pneumococcal bacteremia and pneumococcal meningitis were 0.38, 0.47 and 0.5, respectively. The overall detection rate for H. influenzae infections was 0.92 and for group B streptococcal infections 0.87. Serum and urine from 100 non-infected patients were also tested for the presence of group B streptococcus, S. pneumoniae, N. meningitidis and H. influenzae type b antigens with only 1 false positive (H. influenzae type b).

Antigens, Bacterial↗

Time course of changes in blood pressure, aldosterone and body fluids during enalapril treatment: a double-blind randomized study vs hydrochlorothiazide plus propranolol in essential hypertension.

Aldosterone suppression is said to play a major role in the long term hypotensive efficacy of angiotensin converting enzyme inhibitors. However, in previous reports from other laboratories, plasma volume has been found mostly increased and sodium balance sometimes positive. The effects of the angiotensin converting enzyme inhibitor enalapril (10-40 mg/day, p.o., for 6 weeks) on blood pressure, body fluid volumes, renal function and plasma aldosterone were compared to those of hydrochlorothiazide (50 mg/day, p.o.) alone for 2 weeks and in association with propranolol (80-160 mg/day, p.o.) for 4 more weeks during a randomized double-blind parallel study in 14 essential hypertensives. Hydrochlorothiazide alone and in combination with propranolol induced slight and not significant change in either blood pressure and body fluids. The maximum hypotensive response to enalapril was achieved only after 2 weeks of continuous treatment possibly because after 1 week the hypotensive efficacy was lessened by a significant (P less than 0.05) fluid retention secondary to a transient and not significant fall in renal perfusion. At this time aldosterone was not significantly changed compared to pretreatment values. After 6 weeks on enalapril, blood pressure was significantly reduced, plasma aldosterone further but not significantly decreased and extracellular fluid volume was normal. These findings indicate that aldosterone suppression contributes to the blood pressure lowering effect of enalapril by offsetting the salt and water retention observed on starting treatment and due to direct vasodilation.

Adult↗

Determination of lithium in microlitre amounts of human body fluids at therapeutic and normal levels by stable isotope dilution and field desorption mass spectrometry.

The use of field desorption mass spectrometry for the determination of lithium in body fluids at therapeutic levels--ppm region--as well as at the normal level--ppb region--has been developed. The use of a stable isotope enriched internal standard, together with the outstanding sensitivity of field desorption for alkali cations and the high specificity of mass spectrometry, allows a quantitative determination of lithium in microlitre amounts of body fluids, such as plasma, saliva and urine. The assay allows a determination of lithium even at ultratrace concentrations where routine spectroscopic procedures cannot be applied. Analysis of plasma required a simple protein precipitation, whereas saliva and urine could be analysed without treatment. The precision of the data obtained ranged from 2--10%. The time consumption for one analysis in routine work is about 20--30 min.

Humans↗

Preoptic neuronal circuit: atrial natriuretic peptide-containing neurons are sensitive to acute and chronic alterations in body fluid volume.

Atrial antriuretic peptide (ANP) concentrations were determined in rostral preoptic midline structures (organum vasculosum laminae terminalis, periventricular and medial preoptic nuclei) and in the subfornical organ by radioimmunoassay in rats with acute volume load and volume depletion, as well as during water deprivation. ANP-containing neuronal elements in all four areas (to a lesser extent in the medial preoptic nucleus) reacted very sensitively to acute and chronic changes in body fluid volume: volume load resulted in an elevation, volume depletion in a depletion in ANP concentrations. These alterations were significant and completely matched changes in plasma ANP concentrations. Water deprivation increased ANP levels on the first experimental day, followed by a marked depletion in the organum vasculosum laminae terminalis, subfornical organ and the periventricular preoptic nucleus. It is hypothesized that three major neuropeptides (angiotensin II, vasopressin, ANP) regulate body fluid volume through a close neuronal network along a subfornical organ-preoptic-hypothalamic axis. The subfornical organ, which is very rich in angiotensin II and ANP receptors, serves as an open gate for circulating hormones and is neuronally interconnected with volume-sensitive ANP neurons in the preoptic area (organum vasculosum laminae terminalis and preoptic periventricular nucleus). Neurons in the subfornical organ and the preoptic area project to the supraoptic and paraventricular nuclei and control the activity of vasopressin-synthesizing neurosecretory cells.

Animals↗

[Seasonal variation in the content of free reducing sugars in body fluids of freshwater mollusk Lymnaea stagnalis].

Accumulation of certain mono- and disaccharides in body fluids of ectotherms in autumn and winter suggests their protective role in adaptation to near-zero temperatures. In this context, the effect of seasonal temperature variation on the content of free reducing sugars was studied in freshwater snail Lymnaea stagnalis. The summer and autumn carbohydrate spectrum essentially featured high concentrations of fructose and glucose. After 2.5-month hypobiosis (4 degrees C), the concentration of fructose and glucose decreased 35 and 12 times, respectively. Maltose and other disaccharides (presumably cellobiose) undetectable in summer became detectable in autumn before hypobiosis started. The subsequent level of maltose increased to almost reach the sharply decreased glucose level and to exceed the fructose level after 2.5-month hypobiosis. The involvement of maltose in the mechanisms of L. stagnalis adaptation to near-zero temperatures as a membrane protectant is proposed.

Adaptation, Physiological↗

Apatite-forming ability of carboxyl group-containing polymer gels in a simulated body fluid.

Carboxymethylated chitin, gellan gum, and curdlan gels were soaked in a simulated body fluid (SBF) having ion concentrations nearly equal to those of human blood plasma. Some of the gels had been soaked in a saturated Ca(OH)(2) solution, while others had not. The carboxymethylated chitin and gellan gum gels have carboxyl groups, while the curdlan gel has hydroxyl groups. None of the gels formed apatite on their surfaces in the SBF when they had not been subjected to the Ca(OH)(2) treatment, whereas the carboxymethylated chitin and gellan gum gels formed apatite on their surfaces when they had been subjected to the Ca(OH)(2) treatment. The curdlan gel did not form an apatite deposit even after the Ca(OH)(2) treatment. Apatite formation on the carboxymethylated chitin and gellan gum gels was attributed to the catalytic effect of their carboxyl groups for apatite nucleation, and acceleration of apatite nucleation from released Ca(2+) ions. This result provides a guiding principle for obtaining apatite-organic polymer fiber composites. This composite is expected to have an analogous structure to that of natural bone.

Apatites↗

Anticytotoxin activity of bovine sera and body fluids against Pasteurella haemolytica A1 cytotoxin.

Toxin neutralizing activity of bovine sera and body fluids against Pasteurella haemolytica type A1 cytotoxin was evaluated by 51Cr release assay using bovine peripheral blood mononuclear leukocytes as the target cells. Sera collected from precolostral calves did not exert anticytotoxin activity at 10(-1) or higher dilutions, whereas randomly selected complement fixing antibody-negative sera neutralized on average over 90% of cytotoxin activity at the 10(-1) dilution and less than 50% of the toxin activity at 10(-2) or higher serum dilutions. Nasal secretions and lung washings of some of the cattle tested also contained cytotoxin neutralizing activity. The antibody nature of the cytotoxin neutralizing activity was demonstrated by its neutralization with bovine immunoglobulin G2 purified from pooled seropositive sera. Sera from a group of cattle which were vaccinated with a potassium thiocyanate extract of P. haemolytica, but which subsequently developed fibrinous pneumonia after aerosol challenge with bovine herpesvirus 1 and P. haemolytica, had significantly lower anticytotoxin activity than sera from another group of cattle which did not develop the disease after similar vaccination and challenge. Cattle which survived a natural outbreak of shipping fever had higher anticytotoxin activity than those having fibrinous pneumonia in the aforementioned experimental group, although there was no statistical difference between them and a randomly selected CF seronegative group. It is probable that this cytotoxin neutralizing antibody exerts a beneficial effect in protection of cattle against pneumonic pasteurellosis.

Animals↗

Role of angiotensin converting enzyme inhibitors in essential and renal hypertension. Effects of captopril and enalapril on renin-angiotensin-aldosterone, renal function and hemodynamics, salt and water excretion, and body fluid composition.

Among the many generic classes of drugs currently being used for the treatment of hypertension, few, following long-term therapy, improve or correct the underlying renal function and hemodynamic abnormalities encountered in patients with sustained hypertension. This review focuses on the renal effects of the angiotensin converting enzyme inhibitors captopril and enalapril. Each drug is discussed in terms of its short- and long-term effects on the renin-angiotensin-aldosterone system, renal function and hemodynamics, salt and water excretion, and body fluid composition. Data are presented that demonstrate that enalapril, used alone or in combination with diuretic therapy, has the unique ability to control hypertension, to improve glomerular filtration rate and effective renal plasma/renal blood flow, and to decrease renal vascular resistance, without producing adverse effects on salt and water excretion or body fluid composition. If the safety of enalapril is confirmed in long-term studies, the drug will clearly assume a prominent role as either first- or second-step (in combination with a diuretic) therapy in the treatment of hypertension.

Body Fluids↗

Accumulation of deuterium oxide in body fluids after ingestion of D2O-labeled beverages.

A simple low-cost procedure was developed to compare the temporal profiles of deuterium oxide (D2O) accumulation in body fluids after ingestion of D2O-labeled solutions. D2O concentration was measured in plasma and saliva samples taken at various intervals after ingestion of 20 ml of D2O mixed with five solutions differing in carbohydrate and electrolyte concentrations. An infrared spectrometer was used to measure D2O in purified samples obtained after a 48-h incubation period during which the water (D2O and H2O) in the sample was equilibrated with an equal volume of distilled water in a sealed diffusion dish. The procedure yields 100% recoveries of 60-500 ppm D2O with an average precision of 5%. When compared with values for distilled water, D2O accumulation in serial samples of plasma and saliva was slower for ingested solutions containing 40 and 15% glucose and faster for hypotonic saline and a 6% carbohydrate-electrolyte solution. These differences appear to reflect known differences in gastric emptying and intestinal absorption of these beverages. Therefore this technique may provide a useful index of the rate of water uptake from ingested beverages into the body fluids.

Adult↗

Saliva as an alternative body fluid for therapeutic drug monitoring of the nonnucleoside reverse transcription inhibitor nevirapine.

The objective of this study was to evaluate the applicability of saliva as an alternative body fluid for therapeutic drug monitoring of nevirapine. The pharmacokinetics of nevirapine in plasma and saliva during a dosing interval was assessed in HIV-1-infected patients taking nevirapine (200 mg twice daily) to explore the relation between the concentration of nevirapine in plasma and saliva. To validate the anticipated relationship prospectively, single, paired plasma and saliva samples were obtained from nevirapine-treated HIV-1-infected outpatients. The plasma nevirapine concentration was strongly correlated with the salivary concentration. The mean saliva/plasma concentration ratio was 0.51 and was independent of the time after ingestion. Salivary nevirapine concentrations were used to estimate the corresponding plasma concentrations for 31 outpatients. Compared with the true plasma concentrations, the estimated concentrations were biased by -4.2%, with a precision of 13.3%. These data show a strong correlation between the salivary and plasma concentrations of nevirapine at a dosage of 200 mg twice daily. This relation has been validated prospectively, and the prediction of plasma concentrations was accurate and precise. Therefore, the authors conclude that saliva can be a useful body fluid for therapeutic drug monitoring of nevirapine.

Adult↗

[Determination of "middle molecules" presenting vitamin B12 molecular size in normal and uremic body fluids (author's transl)].

Uremic solutes with the molecular size of vitamin B12 are assumed to be toxic. An analytical method is proposed to detect and separate these solutes in body fluids using two combined techniques: gel filtration on Sephadex G-15 and ion-exchange chromatography on DEAE-Sephadex A-25. The vitamin B12 molecular size has been localized by ultrafiltration through membranes with a defined cut-off. Normal and uremic body fluids (urine, plasma, hemodialysis fluid) have been separated into 9 ultraviolet-absorbing peaks (a to i) by high-speed gel filtration. Peaks b and c present the molecular size of vitamin B12, 10--15 A molecular diameter in pH7 aqueous solution. Peak b, which correlates with uremic neuropathy, is separated into 6 sub-peaks (b1 to b6) by ion-exchange chromatography, sub-peak b4.2 is the only one to correlate with uremic neuropathy. The coefficient of variation in the integrated area of a single peak is 16%. This method gives the chromatographic prolife of the vitamin B12 molecular size from 500 microliter of uremic plasma or 100 microliter of normal urine within one hour.

Chromatography, Gel↗

Apatite formation on silica gel in simulated body fluid: its dependence on structures of silica gels prepared in different media.

It has been shown that the prerequisite for glasses and glass-ceramics to bond to living bone is the formation of a layer of biologically active bonelike apatite on their surfaces. The hydrated silica formed on the surfaces of glasses and glass-ceramics plays an important role in nucleating the apatite. In the present study, the structure of the hydrated silica responsible for the apatite nucleation was investigated in an accellular simulated body fluid with ion concentrations nearly equal to those of human blood plasma. Three kinds of porous silica gels were prepared by hydrolysis and polycondensation of tetraethoxysilane in pure water or in aqueous solution containing polyethylene glycol or polyacrylic acid. The silica gels prepared in aqueous solution containing polyethylene glycol or polyacrylic acid had micron-size interconnected pores, whereas the gel prepared in pure water did not. All the gels contained a large volume of nanometer-size pores, almost the same amounts of silanol groups and D2 defect, and showed a high dissolution rate of the silica. Despite this, only the gel prepared in the solution containing polyethylene glycol formed the apatite on its surface in the simulated body fluid. This indicates that only a certain type of structural unit of the silanol group is responsible for the apatite nucleation.

Acrylates↗