Application of the PrimRglo assay chemistry to multiplexed bead assays

In this unit, we describe a multiplex microsphere quantitative PCR. The system is based on the use of two additional oligonucleotides within a single tube PCR reaction. The first oligonucleotide is modified with a single base pair mismatch and is otherwise equivalent to a universal sequence added to the forward PCR primer. Further, this first extra oligonucleotide is coupled to Luminex microspheres. The second additional oligonucleotide is designed to be complementary to the universal sequence, and is modified with the fluorescent dye Cy3. As the PCR reaction proceeds, the second oligonucleotide is able to bind to the microspheres. Thus, quantitative monitoring of PCR progress takes place. The microsphere-mediated Cy3-detection is measured using flow cytometry directly after the PCR reaction. This allows a flow cytometer analysis from up to 150 different spheres and, therefore, multiple genes in one reaction. The multiplex microsphere qPCR is demonstrated using three target genes from Influenza A and Neisseria meningitidis. The multiplex microsphere system will enable a higher degree of multiplexing than is possible with currently available qPCR systems.

A randomized controlled trial of surgery vs steroid injection for carpal tunnel syndrome

BACKGROUND

Decompressive surgery and steroid injection are widely used forms of treatment for carpal tunnel syndrome (CTS) but there is no consensus on their effectiveness in comparison to each other. The authors evaluated the efficacy of surgery vs steroid injection in relieving symptoms in patients with CTS.

METHODS

The authors conducted a randomized, single blind, controlled trial. Fifty patients with electrophysiologically confirmed idiopathic CTS were randomized and assigned to open carpal tunnel release (25 patients) or to a single injection of steroid (25 patients). Patients were followed up at 6 and 20 weeks. The primary outcome was symptom relief in terms of the Global Symptom Score (GSS), which rates symptoms on a scale of 0 (no symptoms) to 50 (most severe). Nerve conduction studies and grip strength measurements were used as secondary outcome assessments.

RESULTS

At 20 weeks after randomization, patients who underwent surgery had greater symptomatic improvement than those who were injected. The mean improvement in GSS after 20 weeks was 24.2 (SD 11.0) in the surgery group vs 8.7 (SD 13.0) in the injection group (p < 0.001); surgical decompression also resulted in greater improvement in median nerve distal motor latencies and sensory nerve conduction velocity. Mean grip strength in the surgical group was reduced by 1.7 kg (SD 5.1) compared with a gain of 2.4 kg (SD 5.5) in the injection group.

CONCLUSION

Compared with steroid injection, open carpal tunnel release resulted in better symptomatic and neurophysiologic outcome but not grip strength in patients with idiopathic carpal tunnel syndrome over a 20-week period.

Triterpene antioxidants from ganoderma lucidum

Ganoderma lucidum was studied for its antioxidative activity by bioassay guided isolation in conjunction with in vitro tests. The powdered crude drug was treated with boiling water and the aqueous extract (Ex1) was further separated to obtain terpene and polysaccharide fractions. The two fractions and Ex1 were screened for their antioxidative effect against pyrogallol induced erythrocyte membrane oxidation and Fe (II)-ascorbic acid induced lipid peroxidation. All tested samples showed antioxidative activities in a dose dependent manner and the terpene fraction was found to possess the highest effect compared with the others. Chemical isolation of the terpene fraction resulted in the detection of ganoderic acids A, B, C and D, lucidenic acid B and ganodermanontriol as major ingredients.

Chinese herbal medicine and acupuncture. How do patients who consult family physicians use these therapies?

OBJECTIVE

To determine how a population of Chinese patients consulting family physicians in Vancouver use traditional Chinese medicine (TCM), specifically Chinese herbal medicine and acupuncture.

DESIGN

Bilingual survey (English and Chinese).

SETTING

Four family practices with predominantly Chinese patients in metropolitan Vancouver.

PARTICIPANTS

The 932 patients or family members who visited one of the practices.

MAIN OUTCOME MEASURES

Demographic characteristics; frequency and reason for visiting a family physician, Chinese herbalist, or acupuncturist; choice of practitioner if affected by one of 16 common conditions.

RESULTS

The study population was mostly Chinese and immigrant to Canada. Chinese herbal medicine was currently used by 28% (262/930) of respondents (more than one visit in the last year), and another 18% (172/930) were past users. Acupuncture was currently used by 7% (64/927) and had been used in the past by another 8% (71/927). Use of Chinese herbal medicine varied significantly (P < .01) according to age, sex, immigrant status, and ethnicity. Acupuncture use varied significantly only by age. The main reasons for consulting Chinese herbalists were infection (41%, 157/382), respiratory problems (11%, 42/382), and rheumatologic problems (10%, 38/382), whereas acupuncturists were consulted almost exclusively for rheumatologic problems (80%, 45/56).

CONCLUSIONS

Using TCM in conjunction with visiting family physicians was very popular among this predominantly Chinese study population. Patients with acute conditions, such as influenza, consulted both their family physicians and Chinese herbalists in quick succession. On the other hand, those suffering from more chronic conditions, such as rheumatologic diseases, were more likely to start using TCM after repeated visits to their family physicians.

Use of low-dose low molecular weight heparin in hemodialysis

We investigated the lowest effective dosage of low molecular weight (LMW) heparin for hemodialysis in comparison to unfractionated (UF) heparin. Initial hemodialysis sessions were undertaken in 10 uremic patients with UF heparin of the dose habitually required for each patient. Four-hour hemodialysis sessions were then undertaken with LMW heparin (nadroparin) in a single bolus (200 anti-Xa unit Institut Choay/kg [aXaU IC/kg], 175 aXaU IC/kg, 150 aXaU IC/kg, or 125 aXaU IC/kg; two sessions for each dosage). Anti-Xa levels and activated partial thromboplastin time (APTT) were monitored hourly during dialysis. Fiber bundle volume of dialyzer was measured before and after dialysis. Urea clearance was determined at the onset and completion of dialysis. There were no episodes of excessive bleeding, clotting of dialyzers, or clots in air traps with UF heparin or LMW heparin. A 35% increase in APTT above baseline was observed in all dialysis sessions 1 hour after LMW heparin bolus, but the APTT decreased rapidly thereafter. The anti-Xa levels exceeded 0.5 U/mL for all sessions using LMW heparin irrespective of the dosage. No significant reduction of urea clearance was found in dialysis with either UF or LMW heparin. No reduction of fiber bundle volume of dialyzer was observed in dialysis with either UF or LMW heparin, although a small reduction (3%) was observed in dialysis with LMW heparin at 125 aXaU IC/kg. We concluded that the use of LMW heparin for hemodialysis is safe and effective as compared with UF heparin. The lowest effective dosage can be reduced to 125 aXaU IC/kg in high-risk patients to reduce hemorrhagic complications.

Putaminal and thalamic hemorrhage in ethnic chinese living in Hong Kong

BACKGROUND

Hemorrhagic stroke is very common in the Chinese population, and it is one of the leading causes of mortality in Chinese communities. The risk factors to explain this high incidence are unknown. It is the purpose of this study to look into the features of hemorrhagic stroke in the Hong Kong Chinese.

METHODS

We conducted a prospective hospital-based study in which 60 consecutive Chinese patients with computed tomography diagnosis of putaminal or thalamic hemorrhage were included. Their demographic and clinical data were collected and analyzed.

RESULTS

Two major findings evolved from the present study. (1) Unlike the Western studies, the majority of our patients were about a decade younger; (2) 50% of the patients had previously diagnosed hypertension, but only 20% of these patients were compliant with their antihypertensive medication. Our results also suggested that low admission Glasgow Coma Scale scores, large hematoma size, and the presence of intraventricular blood were associated with poor outcomes.

CONCLUSIONS

This study concludes that hemorrhagic stroke is indeed a serious health problem in Hong Kong. Simple measures, such as improvement of health education and the primary care system in the management of hypertension, would help to reduce the incidence of hemorrhagic stroke.

Synthesis, antiinflammatory, and cytotoxic activities of 2-alkyl and 2-benzyl-2-dimethylaminomethyl-5-(E)-arylidene cyclopentanone hydrochlorides

PURPOSE

A series of 2-substituted-2-dimethylaminomethyl-5-(E)-arylidene cyclopentanones, 4 were synthesized. The main objective of this investigation was to explore the structural parameters necessary for antiinflammatory activity in this series of compounds, while keeping cytotoxic action to a minimum.

METHODS

The target compounds were synthesized in two steps commencing with 2-alkyl-cyclopentanones. Antiinflammatory, analgesic and cytotoxic activities were determined in rats. Cytotoxic results were examined in human cell lines.

RESULTS

Eight of the eighteen synthetic substances possessed significant antiinflammatory activity and twelve showed appreciable analgesic action. Cytotoxicity was minimal or non-existent for most of the compounds. The stability of one of the compounds, 4b in both aqueous and non-aqueous media, and an amine exchange reaction with aniline were used to explain the observed antiinflammatory and cytotoxic activities.

CONCLUSIONS

Unlike monosubstituted aminomethyl groups (Mannich bases) at the 2-position of 5-arylidene-2-cyclopentanones, a second substituent at the 2-position increases stability of the Mannich base and significantly decreases cytotoxic activity. Antiinflammatory and analgesic action is retained in many of the compounds, thus strongly indicating that these desired pharmacological results can be obtained without untoward damage to cells.

Synthesis and cytotoxic activities of the amine-exchange products of 2-dimethylaminomethyl-5-(E)-substituted arylidene cyclopentanones with anilines: 2-arylaminomethyl-5-(E)-arylidene cyclopentanones

A series of 2-arylaminomethyl, and 2-(4-morpholinylmethyl)-5-(E)-arylidene cyclopentanones have been synthesized via an amine-exchange reaction. Most of the compounds showed significant cytotoxic activities, in vitro, on various human cancer cell lines. Generally, compounds with a para-chloroanilino moiety were more active than those of other aniline derivatives. No apparent changes were observed by altering the substituents on the arylidene portion. For the majority of active compounds, leukemia is one of the most sensitive subpanels at both GI50 and TGI levels but the least sensitive one at the LC50 level. Colon cancer is one of the most sensitive subpanels in all three levels. COMPARE results indicated that the characteristics, and possibly the mechanism of the cytotoxic properties of the 2-arylaminomethyl derivatives might be different from that of the 2-dialkylaminomethyl derivatives previously reported.

Synthesis and anti-cancer activity of 2-alkylaminomethyl-5-(E)-alkylidene cyclopentanone hydrochlorides

A series of 2-alkylaminomethyl-5-(E)-alkylidene cyclopentanone hydrochlorides (2), have been synthesized and evaluated as anti-cancer agents. These compounds were designed as masked alpha-methylenecyclopentanones, which appear in many cytotoxic or anti-cancer natural products. Most of the synthesized compounds were found to be active towards various human cancer cell lines and many showed significant subpanel selectivity. For compounds containing the same alkylidene moiety (from C3 to C9), the dimethylaminomethyl analogs were more active than structures possessing morpholino-, pyrrolidino-, or piperidino-methyl groups. Alteration of the alkylidene moiety had little effect on anti-cancer potency. The mass spectrum of a glutathione adduct of 2h indicated that the mechanism of action for these anti-cancer agents may be related to the attack at the aminomethyl carbon atom by biological nucleophilic thiols.

Specialty services capitation contracting by HMOs

With health care moving toward prepaid services, HMOs are increasing their contracting activities. Author Linda Wong examines the results of research on the objectives, reasons, satisfaction levels and evaluation methods of 19 HMOs across the United States.

Characterization and kinetic analysis of the intracellular domain of human protein tyrosine phosphatase beta (HPTP beta) using synthetic phosphopeptides

The intracellular domain of human protein tyrosine phosphatase beta (HPTP beta) (44 kDa) was expressed in bacteria, purified using epitope 'tagging' immunoaffinity chromatography, and characterized with respect to kinetic profile, substrate specificity and potential modulators of enzyme activity. A chromogenic assay based on the Malachite Green method was employed for the detection of inorganic phosphate (Pi) released from phosphopeptides by HPTP beta. This assay, modified so as to improve its sensitivity, was adapted to a 96-well microtitre plate format, and provided linear detection between 50 and 1000 pmol of Pi. The cytoplasmic domain of HPTP beta was strongly inhibited by vanadate, molybdate, heparin, poly(Glu, Tyr) (4:1) and zinc ions. In order to explore the substrate preferences of this PTPase, we generated 13-residue synthetic phosphotyrosine-containing peptides that corresponded to sites of physiological tyrosine phosphorylation. HPTP beta demonstrated kcat. values between 76 and 258 s-1 using four different phosphopeptides. The substrate preference of HPTP beta was in the order srcTyr-527 > PDGF-RTyr-740 > ERK1Tyr-204 >> CSF-1RTyr-708 with Km values ranging from 140 microM to greater than 10 mM. The variations in affinity were probably due to differences among the four phosphopeptides compared, particularly with respect to the character of the charged amino acids flanking the phosphotyrosine residue.

Synthesis and biological evaluation of novel potent antagonists of the bombesin/gastrin releasing peptide receptor

This paper reports the synthesis and antagonist activity of 20 C-terminal analogues of gastrin releasing peptide (GRP). The ability of each analogue to inhibit bombesin (BN) stimulated amylase release from rat pancreatic acini was determined, and those showing antagonist activity were further evaluated for their ability to inhibit BN-stimulated [3H]thymidine uptake in serum-starved 3T3 cells. The assays also included two known peptide antagonists, C (Leu14,psi 13,14]BN) and H (N-pivaloyl-GRP20-25-(R)-2-methyl-4-nonylamide) as positive controls. On the basis of these assays we suggest that a des-Met27,Leu26-psi[CH2NHCOCH3]GRP C-terminal octapeptide imparts antagonist activity. The two most active compounds are peptides 14 ([D-Phe19,Leu26-psi(CH2NHCOCH3)]GRP19-26) and 18 ([D-Phe19,Gln20,Leu26-psi(CH2NHCOCH3)]GRP19++ +-26). In their ability to inhibit BN-stimulated [3H]thymidine uptake, the IC50 of peptides C, H, 14, and 18 were 43.2, 31.2, 2.7, and 32.5 nM, respectively. In conclusion, the novel C-terminal psi[CH2NHCOCH3] bond promises to be a useful peptide backbone modification for imparting antagonism in GRP/BN analogues.

Kinetics of the multi-step catalytic degradation of a polymer to its constituent subunits

The stepwise catalytic degradation of a polymer to its constituent subunits results in many molecules of polymers of shorter chain length. Using the Law of Mass Action, ordinary differential equations for each species can be obtained from the set of elementary reactions and these can be integrated to obtain species concentrations as a function of time. A special case of catalytic degradation of polymers, in which one subunit is released at each step, is examined. A mathematical dissertation on the kinetics of the series of reactions involved is presented. The solution of the set of differential equations involve tedious computations and cannot be easily adapted to the analysis of experimental data. Two additional methods of analysis are described. The first one makes use of the property that for any intermediary polymer whose initial and final concentrations are zero, the integral of its concentration with respect to time is inversely proportional to the degradation rate constant. Stepwise calculation of the rate constants can thus be obtained by determining the area under the concentration-time trajectories while the degradation rate constant of the first polymer is known. The second method makes use of the property that the maximum concentration attained by any individual intermediary polymer is inversely proportional to its degradation constant. These methods have the advantage of being simple since the degradation constants can be obtained stepwise from experimental data.

Effect of recombinant alpha 2 interferon with or without prednisone in Chinese HBsAg carrier children

Ninety Chinese hepatitis B surface antigen (HBsAg) carrier children, aged 2-17 years, positive for hepatitis B e antigen (HBeAg) and hepatitis B virus DNA on at least three occasions in 6 months, were randomized into 3 groups. Thirty children received syrup vitamin B complex as control, 29 received 6 weeks of placebo syrup followed by 16 weeks of recombinant alpha 2b-interferon [intron A (rIFN2b)], 5 x 10(6) u/m2 subcutaneously thrice weekly; and 31 received 6 weeks of syrup prednisone (0.6 mg/kg tailed to 0.2 mg/kg) followed by 16 weeks of recombinant alpha 2b-interferon as above. The placebo/prednisone syrup was given on a double-blind basis. At 24 months of follow-up, persistent loss of hepatitis B virus DNA occurred in none of the children in the control group, in one child receiving recombinant alpha 2b-interferon alone, who also seroconverted to anti-HBe and anti-HBs and in five children receiving interferon with steroid priming (p = 0.0571 compared with controls), with four seroconverting to anti-HBe and one also seroconverting to anti-HBs. A rise of transaminases to above twice the upper limit of normal levels during the first 7 months of follow-up occurred in one subject in the control group, four in the group receiving alpha 2b-interferon alone and nine in the group receiving recombinant alpha 2b-interferon with steroid priming (p = 0.0144 compared with controls). Side effects of the steroid were negligible; those of recombinant alpha 2b-interferon were transient and acceptable. We conclude that 6 weeks of prednisone followed by 16 weeks of recombinant alpha 2b-interferon is of use in inducing persistent loss of hepatitis B virus DNA (16.1 per cent) and e-seroconversion (12.9 per cent) in a proportion of Chinese HBsAg carrier children: the prednisone probably enhances the immunomodulatory effect of recombinant alpha 2b-interferon.

Peptidyl aminosteroids as potential new antiarrhythmic agents

The synthesis of peptidyl derivatives of the aminosteroid, amafalone (Am), is described. Six analogs were synthesized: the hydrochloride salts of Gly-Am (2) Ala-Gly-Am (3), D-Ala-Gly-Am (4), Pro-Am (6), Pro-Pro-Am (7), and D-Ala-Pro-Am (8). The peptide bonds were formed by the polymeric reagent method using polymeric hydroxybenzotriazole as the activating polymer. Peptidyl aminosteroids 2, 6, 7, and 8, when administered to rats intravenously, had protective antiarrhythmic effects similar to those of amafalone. By the oral route, less marked protection, in comparison to amafalone, was observed with 6, while 7 and 8 were disappointingly inactive.

Effects of scopolamine on antipredator defense reactions in wild and laboratory rats

Two experiments were designed to investigate the effects of scopolamine hydrobromide (0.25-1.0 mg/kg), and its methyl derivative, on the defensive reactions of rats to nonpainful threat stimuli. In the first experiment, over the dose range studied neither compound significantly altered avoidance, freezing, defensive threat or attack in wild Rattus rattus confronted by the experimenter and other predator-related stimuli. Scopolamine hydrobromide did, however, produce a dose-dependent increase in flight distance; this effect was not seen with the methyl compound, confirming central cholinergic mediation. In the second experiment, no dose of either compound significantly altered the behaviour of Long-Evans rats prior to cat exposure. During cat exposure, however, scopolamine hydrobromide (but not methyl scopolamine) increased the amount of time spent in the vicinity of the cat, increased scanning and rearing, and reduced grooming behaviour. Although reliable, the latter effects were not pronounced. Together, these data do not support a major involvement of central muscarinic receptor mechanisms in the regulation of defensive patterns in wild or laboratory rats.

A mathematical model on the analysis of a one-ligand, one-binding group system when an unknown amount of endogenous ligand is present

In the study of ligand-receptor interaction, binding studies using radiolabelled ligands are usually conducted and results analyzed according to the method originally described by Scatchard. When significant levels of endogenous ligands are present, assumption of a linear relationship between the bound-to-free ratio and the bound ligand may be erroneous and chemical methods have been described to resolve this problem. We present a mathematical approach to the system, using a method based on multiple regression of binding data. A three-dimensional graphic representation of the binding data analogous to the original Scatchard plot is proposed. When the endogenous and the exogenous ligands are different, the linear regression model is applicable only if their affinity constants are known. Non-linear curve-fitting computer programs should be used to resolve this problem when these constants are unknown.

Effect of pregnancy on ritodrine pharmacokinetics

Dosing regimens for ritodrine are based in large part on pharmacokinetic studies performed with nonpregnant subjects. Pregnancy is characterized by changes in renal blood flow, plasma volume, protein concentration, and hepatic function. These physiologic changes frequently alter drug pharmacokinetics. To define the effect of pregnancy on ritodrine kinetics, we compared ritodrine pharmacokinetics in four pregnant and four nonpregnant rhesus monkeys. Significant differences were demonstrated in the distribution phase half-life (0.40 +/- 0.08 hours in the pregnant monkeys and 0.21 +/- 0.03 hours in the nonpregnant animals), volume of distribution (1.99 +/- 0.94 L/kg in the pregnant monkeys and 4.75 +/- 0.90 L/kg in the nonpregnant animals), plasma clearance (18.8 +/- 7.1 ml/min/kg in the pregnant monkeys and 27.2 +/- 5.0 ml/min/kg in the nonpregnant animals), and disposition half-life (1.8 +/- 0.4 hours in the pregnant monkeys and 3.3 +/- 0.4 hours in the nonpregnant animals). Pregnant animals receiving ritodrine had higher steady-state plasma concentrations than nonpregnant animals (104 versus 53 ng/ml at an infusion rate of 2 micrograms/kg/min). These data indicate that dosing regimens for ritodrine based on studies of nonpregnant subjects may be subject to considerable error.

3,4-Dichlorobenzyloxyacetic acid is extensively metabolized to a taurine conjugate in rats

The metabolism of the antisickling agent 3,4-dichlorobenzyloxyacetic acid (3,4-DCBAA) was examined after ip administration to rats. Within 5 days after administration of radiolabeled 3,4-DCBAA, 77.4 +/- 4.6% of the dose was recovered in the urine and only 3.2 +/- 0.5% was recovered in the feces. Metabolites in the urine were isolated and characterized by HPLC, electron impact MS, and LC/MS, and their identities were confirmed by comparing their spectra with those of synthetic standards. Quantitation of these urinary metabolites revealed that the majority of the radioactive dose was excreted as a taurine conjugate (60.1 +/- 4.4%), while lesser amounts were excreted as 3,4-dichlorohippurate, unchanged 3,4-DCBAA, the glycine conjugate of 3,4-DCBAA, and a polar unknown which is believed to be glycolic acid. A pathway involving an initial O-dealkylation at the benzyl carbon of 3,4-DCBAA and proceeding through the glycine conjugation of 3,4-dichlorobenzoic acid has been proposed to explain the formation of 3,4-dichlorohippurate and the polar unknown. The extensive conjugation of 3,4-DCBAA with taurine is an unprecedented observation in rats, which usually utilize glycine for amino acid conjugation reactions. Further studies with 3,4-DCBAA may provide insight into the enzymatic mechanisms of taurine conjugation, which are not well defined at this time.

Enteritis cystica profunda: association with Crohn's disease

Enteritis cystica profunda (ECP), an uncommon condition, is characterized by nonneoplastic cystic spaces within the wall of the small bowel. The cases of two patients who had ECP in association with Crohn's disease are reported, and the role of mucosal damage in the pathogenesis of ECP is discussed. Pathologists must recognize this entity and distinguish it from adenocarcinoma, which may arise with increased frequency in the small bowel in patients with Crohn's disease.

Evaluation of the pharmacodynamics and pharmacokinetics of ritodrine when administered as a loading dose. On establishing a potentially useful drug administration regimen in cases of fetal distress

Inhibition of labor during the intrapartum period has been suggested as a method of managing acute fetal distress. In such cases, rapid tocolysis is desirable but, in high doses, beta-adrenergic-receptor agonists, such as ritodrine, may cause severe maternal hypotension that could aggravate the existing fetal distress. We undertook the present study to establish a safe infusion protocol for ritodrine that achieves high plasma concentration rapidly. Twelve nonpregnant female volunteers received, on separate days, three infusions of ritodrine, that is, 1, 2, and 3 mg, during a 2-minute period. The peak plasma concentration measured by high-performance liquid chromatography with electrochemical detection averaged 37, 74, and 100 ng/ml after the 1, 2, and 3 mg doses, respectively. Ritodrine concentrations decreased rapidly and with the 3 mg dose the ritodrine concentration was only 14 ng/ml after 15 minutes. The elimination phase half-life of ritodrine averaged 6.11 hours. None of the doses significantly affected systolic blood pressure but ritodrine increased heart rate and the plasma glucose level and decreased diastolic blood pressure and the plasma potassium concentration. Even at the highest infusion rate, the maximal changes in cardiovascular and metabolic variables were short-lived and clinically modest; heart rate increased 29 bpm, diastolic blood pressure decreased 8 mm Hg, glucose level increased 26 mg/dl, and potassium concentration decreased 0.6 mEq/L. These data indicate that high plasma concentrations of ritodrine can be achieved rapidly without serious side effects.

Reductive metabolism of furazolidone by Escherichia coli and rat liver in vitro

The metabolism of furazolidone by rat liver and Escherichia coli was characterized in vitro under aerobic and anaerobic incubation conditions. Rat liver 9000g supernatant rapidly metabolized 14C-furazo-lidone to more polar metabolites in the presence or absence of oxygen when NADPH was provided as a cofactor. At least five polar radiolabeled metabolites were detected in these incubations by high pressure liquid chromatography. Moreover, a significant (30-40%) proportion of the total radiolabeled metabolites remained tightly associated with liver protein despite repeated organic solvent extractions of the tissue. The major solvent-extractable metabolites produced under aerobic and anaerobic incubation conditions were isolated and analyzed by mass spectrometry. The mass spectra indicated that these derivatives possessed the same chemical structure. Subsequently, this metabolite was unequivocally identified as 3-(4-cyano-2-oxobutylideneamino)-2-oxazolidinone, an end product of reductive metabolism of the nitro group of furazolidone. The formation of the reduced metabolite under aerobic conditions indicated that this metabolic pathway was markedly less sensitive to oxygen than many previously studied nitroreduction reactions catalyzed by mammalian enzymes. This NADPH-dependent, oxygen-insensitive nitroreductase activity was further localized to the microsomal fraction of rat liver. E. coli also rapidly metabolized furazolidone (FZN) to a complex series of metabolites, including the reduced cyano metabolite, under both aerobic and anaerobic conditions. Sonic lysis of the bacteria released an NADPH-dependent, oxygen-insensitive nitroreductase which converted FZN to the cyano metabolite and other unidentified derivatives. The complete reduction of FZN by the solubilized bacterial enzyme was strongly inhibited by the addition of the thiol nucleophile glutathione to the incubation medium.

Effectiveness of phosphocitrate and N-sulpho-2-amino tricarballylate, a new analogue of phosphocitrate, in blocking hydroxyapatite induced crystal growth and calcium accumulation by matrix vesicles

Phosphocitrate and its analogue N-sulpho-2-amino tricarballylate were compared with ethane-1-hydroxy-1,1-diphosphonate for inhibition of calcium phosphate crystallization in hydroxyapatite induced crystal growth and 45Ca uptake by matrix vesicles. Phosphocitrate (1 microM) was the most potent inhibitor followed by ethane-1-hydroxy-1,1-diphosphonate and N-sulpho-2-amino tricarballylate, the latter requiring a high concentration (100 microM) to be equally effective as an inhibitor.

Analysis of ritodrine in serum by high-performance liquid chromatography with electrochemical detection

A sensitive and specific assay for ritodrine in serum was developed using high-performance liquid chromatography (HPLC) with electrochemical detection. Serum samples were alkalinized to pH 9.4 by the addition of a sodium carbonate buffer and extracted with ethyl acetate. The extracts were evaporated to dryness and the residues were reconstituted in the HPLC mobile phase and chromatographed on a octadecylsilane reverse-phase column. The detection of ritodrine was achieved by an electrochemical detector with a glassy carbon electrode. The sensitivity was 0.2 ng for on-column injection. The extraction efficiency was 80%.

Pharmacodynamics of ritodrine in pregnant women during preterm labor

We evaluated the relationship of ritodrine concentration to several maternal variables and to fetal heart rate in 17 women who received the drug for inhibition of preterm labor. Ritodrine was measured by high-performance liquid chromatography with electrochemical detection. Ritodrine increased maternal and fetal heart rate and decreased serum potassium in a dose-related manner, but wide variability was noted between patients and within individual patients. Tachyphylaxis of the maternal heart rate response to continuing treatment with ritodrine was seen in at least seven women. Maternal blood pressure, serum glucose concentration, and frequency of uterine contractions were changed by ritodrine treatment, but the changes in these variables were not closely correlated to the concentration of ritodrine (r less than or equal to 0.30 in all cases). The maximal infusion rate and the concentration of ritodrine in maternal serum after 4 hours of treatment were significantly (p less than 0.001) correlated with the frequency of uterine contractions prior to treatment. Successful inhibition of labor was achieved with serum concentrations of 15 to 31 ng/ml in 10 of 17 women; in six of the other seven women, labor could not be inhibited in spite of serum concentrations of 90 to 146 ng/ml. Side effects, such as hypotension, vomiting, chest discomfort, and shortness of breath, were most commonly observed when the infusion rate and concentration of ritodrine were increasing.

Metabolism of 7,12-dimethylbenz[a]anthracene by Cunninghamella elegans

The metabolites of 7,12-dimethylbenz[a]anthracene (DMBA), a carcinogenic polycyclic aromatic hydrocarbon, in cultures of Cunninghamella elegans were isolated by high-pressure liquid chromatography and characterized by UV spectroscopy and mass spectrometry. The major metabolites were DMBA-trans-8,9-dihydrodiol and DMBA-trans-3,4-dihydrodiol. The 7-hydroxymethyl and the 12-hydroxymethyl derivatives of these dihydrodiol metabolites were also formed. The metabolic profile described in this report contrasts with those obtained in our earlier experiments in which the incubation of DMBA with Pseudomonas aeruginosa and Penicillium notatum produced no dihydrodiol metabolites but only methyl-hydroxylated metabolites.

Comparative metabolism of 7,12-dimethylbenz[a]-anthracene and its non-carcinogenic 2-fluoro analogue by Syrian hamster embryo cells

The metabolism of 7,12-dimethylbenz[a]anthracene (DMBA) and its non-carcinogenic 2-fluoro analogue (2F-DMBA) by Syrian hamster embyro (SHE) cells has been studied using high pressure liquid chromatography (HPLC) and fluorescence spectroscopy. Metabolites produced by SHE cells were compared chromatographically to those produced on a larger scale by liver microsomal preparations and previously identified by gas chromatography and mass spectrometry. At least 2 (possibly 3) phenol metabolites, none of which appear to be in the A-ring, were formed from [3H] 2F-DMBA and totalled only 3% of the organic extractable activity present in the media at 24 h. On the other hand, 3 A-ring phenols (DMBA-2-ol, DMBA-3-ol and DMBA-4-ol) comprising almost 12% of the total organic extractable radioactivity at 24 h were identified as metabolites in SHE cell culture media. For both hydrocarbons the major organic extractable metabolite present at 24 h was the respective 8,9-dihydro-dihydroxydiol (DMBA 45%, 2F-DMBA 39%). Thus, substitution of fluorine for hydrogen at the 2-carbon of DMBA appears to block or greatly reduce the A-ring metabolism of this compound but has relatively little effect on D-ring oxidation. Therefore loss of the carcinogenic/mutagenic activity of DMBA correlates with the extent of A-ring metabolism including, possibly, the bay region diol epoxide.

Hemolytic disease of the newborn following maternal self-injection of blood

A teenage primigravida with no prior history of transfusion presented with anti-D, anti-C, and anti-E in her serum and subsequently developed anti-Fya. The infant had hemolytic disease of the newborn. The antibodies were provoked by the girl's self-injection of her partner's blood for emotional gratification. Clinicians and transfusion services should be aware that hemolytic disease of the newborn in a first pregnancy can be caused by self-inflicted maternal immunization. Close communication between clinicians and transfusion service is emphasized.

In vitro metabolism of selected fluoro analogs of 7,12-dimethylbenz[a]anthracene

We have compared the metabolite profiles generated from the rat liver incubation of monofluorinated derivatives of 7,12-dimethylbenz[a]anthracene. These monofluoro analogs are known to exhibit varying degrees of carcinogenicity. In this study we observed that the presence of fluorine substituents blocked metabolism at the fluorinated positions, some of which may be critical for biological activity. Furthermore, we also found that the fluorine substituents affected the chemical reactivity of the 5,6-arene oxide metabolites in terms of their ability to undergo methanolysis.

Comparison of six different criteria for judging the acceptability of sputum specimens

A series of 391 unselected expectorated sputum specimens was examined microscopically, and six different published criteria for judging the acceptability of the specimens were applied. Of the 391 specimens, 234 were found to be acceptable or unacceptable by all six criteria; 157 specimens were discrepant. By the criteria of Murray and Washington and of Barry, 25 and 23% of the specimens, respectively, were rejected; only 19 of 143 specimens which contained potential pathogens as part of their predominant microbial flora were rejected by both sets of criteria. The criteria described by Geckler et al. and Bartlett missed fewer potential pathogens; only 9 or 17% of the specimens, respectively, were found unacceptable. The criteria of Heineman and Radano and of Van Scoy resulted in the greatest percentages of specimens judged unacceptable (28 and 29%, respectively), including 19 and 24% of specimens containing potential pathogens. The reproducibility of sputum screening results was also assessed, comparing the method of Murray and Washington with that of Barry. Six separate slides were prepared from each of 45 different specimens: three samples with purulent or bloody flecks and three samples in which the specimens had been mixed with an applicator swab. Satisfactory reproducibility was observed with both criteria and both sampling methods; no significant differences in reproducibility could be documented in this limited series.

Microbial transformations of 7,2-dimethylbenz[a]anthracene

Microbial transformations of 7,12-dimethylbenz[a]anthracene, a carcinogenic polycyclic aromatic hydrocarbon, in cultures of Pseudomonas aeruginosa and Penicillium notatum were studied by high performance liquid chromatographic separation of metabolic fractions followed by gas chromatographic-mass spectrometric analysis of the metabolites. Two methyl-hydroxylated metabolites were identified in each of the incubations. The metabolic activation of the polycyclic aromatic hydrocarbon suggests a possible involvement of microorganisms in environmental carcinogenesis.

Complete separation by high performance liquid chromatography of metabolites of arachidonic acid from incubation with human and rabbit platelets

Separation of all major cyclooxygenase and lipoxygenase metabolites of arachidonic acid were obtained by high performance liquid chromatography (HPLC). A C18 reverse-phase column was used in ion suppression mode to separate underivatized metabolites of arachidonic acid isolated from human and rabbit platelets. The metabolites were monitored by measuring radioactivity or ultraviolet light absorption at 192 nm (absorption by double bonds). Comparisons of TLC and HPLC separations demonstrated that the HPLC separation of metabolites of [1-14C]arachidonic acid was quantitative. HPLC also resolved several metabolites that were not detected by scanning of TLC separations.

Oxidative metabolites of 7,12-dimethylbenz[a]anthracene. Further investigation of the K-region epoxide

Metabolism of 7,12-dimethylbenz[a]anthracene in rat liver 10,000 g supernatant fraction has been examined by combined gas chromatography-mass spectrometry subsequent to high-pressure liquid-chromatographic separation of the incubation mixture. In addition to the mono-, di-, and trihydroxylated oxidative metabolites usually associated with the biotransformation of polycyclic aromatic hydrocarbons, we observed the formation of a methanolysis product from the K-region epoxide intermediate during the workup procedure. The identification of this compound provides a direct evidence for the presence of the K-region epoxide in the metabolism mixture, and it serves as a convenient means to assay for this metabolite. Moreover, we detected the methanolysis derivative only from the K-region epoxide but none from the non-K-region counterparts. This finding suggests that the non-K-region epoxides undergo facile enzymatic and nonenzymatic hydrolysis and/or rearrangement reactions as soon as they are produced. On the other hand, the K-region epoxide possesses greater stability. It can remain longer in a metabolism mixture and react with methanol subsequently.

Mass spectral characterization of the K-region and non K-region dihydrodiols of 7,12-dimethylbenz (a) anthracene

Dihydrodiols are derived from intermediary arene oxides during the metabolism of polycyclic aromatic hydrocarbons. In this study, the mass spectra of the trimethylsilyl ether derivatives obtained from the 5,6-dihydrodiol and 8,9-dihydrodiol of 7,12-dimethylbenz [a] anthracene were compared. The mass spectral fragmentation patterns indicate some key features in distinguishing a K-region dihydrodiol from its non K-region isomer. The 8,9-dihydrodiol, a non K-region metabolite, exhibits a greater tendency to undergo a ring contraction fragmentation process while the K-region 5,6-dihydrodiol participates preferably in other fragmentation pathways. The data presented in this report will be useful in charcterizing K-region and nonK-region metabolic epoxidation of polycyclic aromatic hydrocarbons.

Preliminary studies on the mucus secretion of the wood wasp, Sirex noctilio F. I. Physicochemical and biochemical properties

The major component of S. noctilio mucus appears to be a protein-polysaccharide complex with probable molecular weight in the range 60000-100000. In aqueous solution the macromolecule undergoes slow spontaneous disaggregation to yield dialysable subunits of molecular weight 2000-6000 which retain all the physiological activity of the whole mucus. More rapid disaggregation is brought about by treatment of solutions with moderate concentrations of NaCl, KC1 OR CaCl2, or by heating. The native mucus contains amylase, esterase, phenoloxidase and proteolytic enzyme activities, and it is suggested that these enzymes may be responsible, at least in part, for the "natural" disaggregation process.

Methylation artifacts in the gas chromatography of serum extracts. Competitive suppression with trimethyl-d9 anilinium hydroxide

In the course of the identification of drugs in body fluids by gas chromatography-mass spectrometry we have observed the appearance of N-methyl derivatives of certain compounds such as phenobarbital and diphenylhydantoin, especially in extracts of serum. With the aid of deuterium labelled phenobarbital it could, however, be shown that the N-methyl derivatives are not endogenous metabolites but artifacts generated upon injection of the serum extract into the gas chromatograph. Conversely, derivatization with trimethyl-d9 anilinium hydroxide (TMAH-d9) demonstrated the absence of any undeuterated methyl derivative and this reagent should be useful for the detection of endogenous N-methyl derivative which would, of course, remain undetected when using unlabelled TMAH in the course of the conventional methylation technique. There are good indications that lecithin is the methylating agent in serum responsible for the formation of these artifacts.

Preliminary Studies on the Mucus Secretion of the Wood Wasp, Sirex Noctilio F. I. Physicochemical and Biochemical Properties

The major component of S. noctilio mucus appears to be a protein-polysaccharide complex with probable molecular weight in the range 60000-100000. In aqueous solution the macromolecule undergoes slow spontaneous disaggregation to yield dialysable subunits of molecular weight 2000-6000 which retain all the physiological activity of the whole mucus. More rapid disaggregation is brought about by treatment of solutions with moderate concentrations of NaC!, KCI or CaCI2 , or by heating. The native mucus contains amylase, esterase, phenoloxidase and proteolytic enzyme activities, and it is suggested that these enzymes may be responsible, at least in part, for the 'natural' disaggregation process.