Studies on effect of co-processing on palmyrah and maize starch mixtures using DOE approach

Starch mixture is an important approach in designing drug delivery system with modulated properties. The aim of the present work is to study the effect of pregelatinization on starch mixture by varying the concentration of palmyrah and maize starch. All the starch mixtures were statistically designed using 3² full factorial design. Further, the mixtures were characterized for physicochemical and drug release properties. The amylose content, water holding capacity (WHC), swelling and solubility power tend to increase with increase in pregelatinization time. The X-ray diffractogram (XRD) confirmed the reduction in crystallinity of starch mixture with increase in pregelatinization time. The FT-IR study confirmed the gelatinization characteristics of the mixture. All the pregelatinized starch mixture exhibited shear-thinning behavior. Micromeritic property of various starch mixture showed the good flow properties. Formulation with this novel excipient system, using paracetamol as model drug indicated its utility for immediate release dosage form.

Control and support models of help-seeking behavior in women experiencing domestic violence in India

In India, there is limited prioritization of domestic violence, which is seen as a private and family matter, and handled as a social responsibility rather than a complaint or crime. Despite the Domestic Violence Act, implemented in 2006, the widespread phenomenon of domestic violence across Indian states goes unreported. Using control and support models, this article aims to examine women's behavior in seeking help while dealing with partner violence. It is a population-based analytical cross-sectional study covering 14,507 married women from 18 states of India, selected through a systematic multistage sampling strategy. Both quantitative and qualitative methods were used to generate data. It was observed that legal complexities combined with social realities make the life of an average Indian woman insecure and miserable. Most women surveyed preferred the social-support model and opined that if they face domestic violence, they would seek help from their parents as the first option in the order of preference. The responses of women while dealing with domestic violence are often spontaneous and determined by the pressing need to resolve matters within the home/community, rather than addressing them in the public domain of state institutions where procedures are cumbersome and lengthy. A new integrated development model proposed by several communities aims to prevent domestic violence through the intervention of health care systems.

Domestic violence during pregnancy in India

Domestic violence can result in many negative health consequences for women's health and well-being. Studies on domestic violence illustrate that abused women in various settings had increased health problems such as injury, chronic pain, gastrointestinal, and gynecological signs including sexually transmitted diseases, depression, and posttraumatic stress disorder. This article tries to understand the association between domestic violence and pregnancy outcomes and other health consequences. The study was carried out in all the six zones of India that is, northern, southern, eastern, western, central, and northeast zones. The study design was conceived as an analytical cross sectional study with multicenter approach. Multistage sampling and then probability proportion to size (PPS) sampling were done. A total of 18 states were taken for the study with a total sample of 14,507 married women and 14,108 married men. Married men were considered from the neighboring villages to understand men's perspective. To understand the situation, women were interviewed using semistructured questionnaire as well as qualitative data like FGD and case studies. The result shows that domestic violence occurs during pregnancy across six zones. The situations become worse for women if her husband or family perceived the pregnancy to be a female child and there is a demand for male child. It has major health implications in accessing and utilizing antenatal care and immunization.

Study of glucose uptake activity of Helicteres isora Linn. fruits in L-6 cell lines

The effect of hot water extract of fruits of Helicteres isora on glucose uptake was studied in rodent skeletal muscle cells (L-6 cells) involved in glucose utilization. H. isora is an antidiabetic medicinal plant being used in Indian traditional medicine. Hot water extracts were analysed for glucose uptake activity and found to be significantly active at 200 mug/ml dose comparable with insulin and metformin. Elevation of glucose uptake by H. isora in association with glucose transport supported the upregulation of glucose uptake. It was concluded that hot water extract of H. isora activate glucose uptake in L-6 cell line of mouse skeletal muscles.

Correlates of relationship, psychological, and sexual behavioral factors for HIV risk among Indian women

The rate of HIV/AIDS among women in India is expected to rise yet few studies have examined factors related to HIV risk among Indian women. The objective of this prospective, cross-sectional study was to characterize similarities and differences in the relationships, psychological well-being, and sexual behaviors among Indian women (N=459). Both HIV positive (N=216) and negative (N=243) women from urban and rural areas in India were included in this study. Chi-square, analysis of variance, and logistic regression analyses revealed that in both geographic groups, HIV-positive women were significantly more likely to report marital dissatisfaction, a history of forced sex, domestic violence, depressive symptoms and husband's extra marital sex when compared to the HIV-negative women. Findings also indicate that specific factors related to the quality of the marital relationship such as domestic violence, martial dysfunction, and depressive symptoms may be related to HIV-related risks for women. Implications for future research and culturally relevant interventions are discussed.

Biosynthesis of vitamin B(6) in yeast: incorporation pattern of glucose

Two yeasts, Saccharomyces cerevisiae ATCC 7752 and Candida utilis ATCC 9256, were incubated in the presence of variously multiply (13)C-labeled samples of D-glucose. The (13)C incorporation pattern within pyridoxamine dihydrochloride, established by (13)C NMR spectroscopy, differed from that which had previously been found within pyridoxine, isolated from Escherichia coli. Thus, the origin of the carbon skeleton of vitamin B(6) in yeast differs substantially from its origin in E. coli. In particular, in yeast the distribution of (13)C within the C(5) chain C-2',2,3,4,4' of pyridoxamine corresponds to the distribution of (13)C within the C(5) chain C-1,2,3,4,5 of the ribose component of cytidine. It follows that the C(5) chains of pyridoxamine and of ribose originate from a common glucose-derived pentulose or pentose intermediate. By contrast, in E. coli the C(5) chain of pyridoxine is derived from 1-deoxy-D-xylulose 5-phosphate which, in turn, originates by condensation of pyruvic acid with glyceraldehyde 3-phosphate.

Evaluating contraceptive choice through the method-mix approach. An Indian Council of Medical Research (ICMR) task force study

The method-mix approach was used to evaluate informed contraceptive choices in the present study. A total of 8,077 potential clients were given a balanced presentation of all available contraceptive methods in the national program, ie, the CuT 200 intrauterine device (IUD), low-dose combined oral pills (OC), condom, and sterilization (female/male) along with a new method, Norplant(R).(1) The majority of women opted for spacing methods; among them, the IUD was preferred by about 60% of clients, followed by condoms (9%), OC (6%), and Norplant (5%). Sterilization, mainly female, was accepted by about 17% of the women making an informed choice. The economic status of couples did not influence the contraceptive choices, as all the methods were offered free of cost in the present study, which is the current practice in the national program. Illiterate women more often accepted sterilization (about 25%) than did literate women (15%). This is because illiterate women had more children; about 30% of illiterate women had three or more children, as opposed to 16.2% of literate women. However, literacy status did not influence the choice of any specific spacing method. The study also revealed that, by encouraging potential clients to make an informed choice, they could override the provider's bias while accepting a particular type of spacing method. This is evident from the observation that Norplant was the first choice of the provider for 35% of the women, whereas only 5% of women preferred and accepted Norplant. The present study stresses an urgent need to promote the practice of informed choices in the national program with a variety of contraceptive options-especially, spacing methods for improving contraceptive prevalence and reproductive health in the country.

Serum bupivacaine concentrations during continuous extrapleural infusion

PURPOSE

To determine the rate of increase in serum bupivacaine concentration during continuous extrapleural infusion.

METHODS

After thoracotomy for lobectomy under general anaesthesia, nine patients had an extrapleural catheter inserted, before chest closure, in a costovertebral gutter constructed surgically by lifting the parietal pleural. Bupivacaine 0.5% with epinephrine 1:200.000 was injected through the catheter as 0.3 ml.kg-1 bolus followed by 0.1 ml.kg-1.hr-1 for five days. Serum bupivacaine (free and total), albumin, alpha-1 acid glycoprotein concentrations were measured 15 min after injection and at 24 hr intervals for five days. Bupivacaine concentrations were determined by column liquid chromatography using solid phase extraction. Serum alpha-1 acid glycoprotein concentration was determined by nephelometry on QM 300 protein analyzer. Serum albumin concentration was determined by bromocresol green dye binding procedure on Hitachi 717 Autoanalyzer.

RESULTS

A continuous elevation in total serum bupivacaine was observed, with an average value of 0.75 microgram.ml-1 on day 1 to 2.77 micrograms.ml-1 on day 4 (P < 0.05). There was no increase in postoperative free serum bupivacaine concentration; average value of 177 pcg.ml-1 on day 1 and 249 pcg.ml-1 on day 4 (P = 0.92). Postoperative serum alpha-1 acid glycoprotein concentration showed a steady rise with an average value of 0.94 microgram.ml-1 on day 1 and 1.47 micrograms.ml-1 on day 4 (P < 0.05). No change was observed in post-operative serum albumin with an average value of 31.4 g.l-1 on day 1 and 31.3 g.l-1 on day 4.

CONCLUSION

Continuous extrapleural infusion of bupivacaine over five days after thoracotomy is associated with a steady increase in total serum bupivacaine concentration and no elevation in free serum bupivacaine concentration.

Optimization of the determination of 4-aminopyridine in human serum and urine by column liquid chromatography

Two convenient reversed-phase column liquid chromatographic procedures are described for the determination of 4-aminopyridine in human serum and urine. A 0.5-ml aliquot of serum after the addition of a 0.5-ml solution of 4-(aminomethyl)pyridine in 0.1 M Na2HPO4 as the internal standard is passed through a 1-ml BondElut C18 silica extraction column. The column is selectively washed to remove acidic, neutral and weakly basic compounds. The desired compounds are eluted with a 0.3-ml aliquot of 35% perchloric acid-methanol (1:100, v/v). A 10-microliters aliquot of the eluate is injected onto a 150 x 4.6 mm I.D. column packed with 5-microns C18 silica particles that is eluted at ambient temperature with a mobile phase containing octanesulfonic acid as the ion-pairing agent. The peaks are monitored at 263 nm. A. 0.25-ml aliquot of urine or 0.5 ml of serum is mixed with N-propionylprocainamide as the internal standard and subjected to benzoylation by Schotten Baumann reaction. The reaction mixture is adjusted to pH 5.5-6 and extracted with a BondElut C18 extraction column. An aliquot of the eluate is chromatographed at ambient temperature with a mobile phase containing tetramethylammonium perchlorate. The peaks are monitored at 278 nm.

Column liquid chromatographic determination of clozapine and N-desmethylclozapine in human serum using solid-phase extraction

A 0.5-ml aliquot of a serum sample, after the addition of a 50-microliters aliquot of a 5 microgram/ml solution of amoxapine as the internal standard, is vortex-mixed with 0.5 ml of acetonitrile and centrifuged. The supernatant is applied to a 1-ml BondElut C18 silica extraction column-conditioned with subsequent washings with 1 M HCL, methanol and water. After passing the sample at a slow rate, the column is washed twice with water and once with acetonitrile. The desired compounds are then eluted with a 0.25-ml aliquot of 35% perchloric acid-methanol (1:100, v/v). A 15 microliters aliquot of the eluate is injected onto a 150 x 4.6 mm I.D. column packed with 5-microns C8 silica particles and eluted at ambient temperature with a mobile phase of 0.1% tetramethylammonium perchlorate-acetonitrile (73:27, v/v) adjusted to pH 4.2 with 10% perchloric acid. The peaks are detected with an absorbance detector at 245 nm.

Column liquid chromatographic determination of paroxetine in human serum using solid-phase extraction

A 0.5-ml aliquot of a serum sample, after the addition of a 100-microliters aliquot of a 5 micrograms/ml solution of dibucaine as the internal standard, is vortex-mixed with 0.5 ml of acetonitrile and centrifuged. The supernatant is applied to a 1-ml BondElut C18 silica extraction column conditioned with subsequent washings with 1 M HCl, methanol and water. After passing the sample at a slow rate, the column is washed twice with water and once with acetonitrile. The desired compounds are then eluted with a 0.25-ml aliquot of 35% perchloric acid-methanol (1:40, v/v). A 7-microliters aliquot of the eluate is injected onto a 150 x 4.6 mm I.D. column packed with 5-microns C8 silica particles and eluted at ambient temperature with a mobile phase of 10 mM phosphate buffer-acetonitrile (2:1, v/v) (pH 3.2). The peaks are detected with a fluorescence detector (excitation at 295 nm, emission at 365 nm). The resulting chromatogram is clean with no extraneous peaks. Paroxetine and dibucaine give sharp peaks which are well separated from each other and from the solvent peaks. The extraction recovery of the drug and the internal standard is in the range of 90% which allows a highly sensitive determination of paroxetine.

Column liquid chromatographic determination of bupivacaine in human serum using solid-phase extraction

A convenient and economical procedure for the extraction of bupivacaine and its major metabolites, desbutylbupivacaine and 4'-hydroxybupivacaine, from serum is described. A 0.25-ml aliquot of 4 micrograms/ml solution of N-pentyl-2,6-pipecoloxylidide used as the internal standard and an equal volume of the serum sample are applied to a 1-ml BondElut C18 silica extraction column which has been conditioned by subsequent washing once with 1 M HCl, twice with methanol and once with water. After passing the sample at a slow rate, the column is washed twice with water and once with acetonitrile. The desired compounds are then eluted with a 0.25-ml aliquot of a mixture of 35% perchloric acid-methanol (1:40, v/v). A 5-microliters aliquot of the eluate is injected onto a 150 x 4.6 mm I.D. column packed with 5-microns C8 silica particles, which is eluted at ambient temperature with a mobile phase of acetonitrile-10 mM KH2PO4 (25:80, v/v) at a flow-rate of 1.5 ml/min. The peaks are detected at 205 nm. The extraction recovery of all the compounds is in the range of 90%. The chromatogram is clean and the desired peaks are well separated from each other and from the extraneous peaks.

Optimization of a column liquid chromatographic procedure for the determination of plasma salbutamol concentration

A reversed-phase column liquid chromatographic procedure with fluorescence detection for the determination of salbutamol in plasma is described. A l-ml aliquot of the sample, after the addition of bamethan as the internal standard, is passed through a Bond Elut silica extraction column. The column is selectively washed to remove neutral, acidic, and weakly basic compounds. The desired compounds are eluted with a l-ml aliquot of methanol. The eluate is evaporated under vacuum at ambient temperature and the residue is reconstituted in 40 microliters of the mobile phase which contains octanesulfonic acid as the ion-pairing reagent. The entire extract is injected onto a 150 x 4.6 mm I.D. column packed with 5-micron octylsilica particles. Peaks are detected with a fluorescence detector (excitation wavelength = 275 nm, emission wavelength = 310 nm). In the resulting chromatogram, salbutamol and the internal standard give sharp peaks that are well resolved from the extraneous peaks. The procedure allows the quantitation of salbutamol down to 0.2 ng/ml.

Use of traditional medical practitioners to delivery family planning services in Uttar Pradesh

This pilot study conducted in Muzaffarnagar district in the state of Uttar Pradesh, India, demonstrates the potential for using traditional medical practitioners in the delivery of family planning services after a brief training period. Practitioners participated continuously in the program for an intervention period of two years during which their services were accepted by the community. The impact of their involvement was reflected in increased knowledge of permanent as well as reversible contraceptive methods and in higher contraceptive use rates, especially of reversible methods adopted by women younger than 25 years (from 8 percent to 37 percent), in the intervention villages, as compared with increased knowledge and use (from 13 percent to 25 percent) of permanent methods alone in the control villages.

Influence of renal clearance on peripheral homovanillic acid measurements in healthy subjects and schizophrenic patients

In order to investigate the effect of renal clearance on plasma homovanillic acid (HVA) concentrations, we examined plasma concentration and urinary excretion of HVA and creatinine per 4 h over 24 h in eight male schizophrenic patients and eight healthy male subjects. Renal clearances of HVA and of creatinine were determined per 4 h period. No significant differences were found between groups in the total 24 h excretion of either HVA or creatinine. Although differences between groups in plasma HVA concentrations and urinary HVA excretion per 4 h did not reach statistical significance, the renal clearance of HVA was significantly lower in the patient group than in the control group. There was no difference between groups in creatinine clearance. Diurnal changes were seen in the renal clearance of HVA and creatinine in both groups. Renal HVA clearance decreased from 23.00-07.00 h, with a coincident decrease in urinary HVA excretion and an increase in plasma HVA concentration. We provide evidence that renal clearance is an important determinant of plasma HVA concentration, and should be considered when interpreting plasma HVA data.

Determination of plasma homovanillic acid by liquid chromatography with electrochemical detection

We describe a simple method for extracting homovanillic acid (HVA) from plasma. An aliquot of 0.5 ml of the internal standard solution (3-hydroxy-4-methoxycinnamic acid in 0.2 mol/l phosphoric acid) and 0.5 ml of the sample are applied to a 1-ml Bond Elut C18 column prewashed with methanol and 0.2 mol/l phosphoric acid. The sample is drawn through the column at low speed. The column is washed with water and eluted with dichloromethane. The eluate is evaporated under vacuum at ambient temperature and the residue reconstituted with 250 microliters of the mobile phase. A 10-microliters aliquot of the resulting solution is injected onto a 150 mm x 4.6 mm I.D. column packed with 5-microns octadecylsilyl silica particles (Beckman). Peaks are detected coulometrically in the screening-oxidation mode with E1 = +0.25 V and E2 = +0.38 V. In the resulting chromatogram, HVA and the internal standard give sharp peaks and are well separated from solvent and other endogenous electroactive acids. The extraction recovery is 90-95% which allows the determination of 0.5 microgram/l analyte.

Platelet alpha 2-adrenergic receptors in depressed patients and healthy volunteers: the effects of desipramine

Binding parameters (Bmax and Kd) of alpha 2-adrenergic receptors were studied in platelets from 14 depressed patients and 18 control subjects. Using 3H-clonidine (a partial alpha 2-adrenergic agonist) as the ligand and membranes, prepared from platelets isolated under physiological conditions, we found no significant differences in Bmax and Kd between medication free patients and control subjects. Platelet binding parameters in the depressed patients did not correlate with plasma levels of norepinephrine, epinephrine or MHPG. Age had a significant positive effect on platelet alpha 2-adrenergic receptor Bmax in both groups, and may have masked the patient-control differences. Treatment with desipramine for 28 days had no effect on the binding parameters in depressed patients when compared to pretreatment values. Adding desipramine to platelets of control subjects 'in vitro' did also not affect binding parameters. Our findings suggest that receptor binding studies with a partial alpha 2-adrenergic agonist in platelet membranes are not a useful model to test the hypothesis of a central supersensitive adrenergic system in depression.

Drug level monitoring: antidepressants

The determination of antidepressant drugs which act by blocking neuronal uptake of biogenic amines, because of their widespread use and high toxicity, remains one of the most commonly requested drug assays in clinical laboratories. Easy to use immunoassay reagents for the estimation of these drugs are commercially available. However, immunoassays have not been universally accepted because of high probability of these reagents producing false negative and false positive results. At present, column liquid chromatography with absorbance detection and coupled with solid-phase extraction is the most viable technique for a general procedure for the identification and determination of these drugs. The technique of liquid chromatography is economical, environmental friendly since water-miscible and biodegradable solvents can be used for extraction of drugs and their chromatographic separation, and amenable to full automation. New techniques of separation, such as supercritical fluid chromatography and capillary zone electrophoresis, have not yet been applied for the determination of therapeutic concentrations of antidepressants.

Improved sample preparation in determination of urinary metanephrines by liquid chromatography with electrochemical detection

In this relatively simple procedure for extracting metanephrines from urine, after an internal standard (4-hydroxy-3-methoxybenzylamine in 1 mmol/L HCl) is added, the sample is hydrolyzed in a boiling water bath, then treated with ammonia and alumina. Excess ammonia is removed under reduced pressure and the sample is applied to a 1-mL Bond Elut SCX column, which is washed, and metanephrines and internal standard are eluted with 0.5 mmol/L sodium acetate/acetonitrile (3/1 by vol). Of this elute, 5 microL is injected into a 15 cm x 4.6 mm (i.d.) column packed with 5-microns octadecylsilyl silica particles, which is eluted with a mobile phase containing tetramethylammonium perchlorate. Peaks are detected coulometrically at +0.28 V. In the resulting chromatogram, metanephrines give sharp peaks, well resolved from peaks for solvent and internal standard. There are no extraneous peaks for catechols or mono-oxygenated phenylethylamines. Results correlated well (r = 0.999, n = 13) with those by earlier described liquid-chromatography.

Improved sample preparation in determination of urinary metanephrines by liquid chromatography with electrochemical detection

In this relatively simple procedure for extracting metanephrines from urine, after an internal standard (4-hydroxy-3-methoxybenzylamine in 1 mmol/L HCl) is added, the sample is hydrolyzed in a boiling water bath, then treated with ammonia and alumina. Excess ammonia is removed under reduced pressure and the sample is applied to a 1-mL Bond Elut SCX column, which is washed, and metanephrines and internal standard are eluted with 0.5 mmol/L sodium acetate/acetonitrile (3/1 by vol). Of this elute, 5 microL is injected into a 15 cm x 4.6 mm (i.d.) column packed with 5-microns octadecylsilyl silica particles, which is eluted with a mobile phase containing tetramethylammonium perchlorate. Peaks are detected coulometrically at +0.28 V. In the resulting chromatogram, metanephrines give sharp peaks, well resolved from peaks for solvent and internal standard. There are no extraneous peaks for catechols or mono-oxygenated phenylethylamines. Results correlated well (r = 0.999, n = 13) with those by earlier described liquid-chromatography.

Concentration response relationships of amiodarone and desethylamiodarone

Twelve patients with frequent ventricular premature depolarizations (VPDs) received amiodarone, 600 mg/day, for up to 8 weeks. On days 0, 1, 4, 8, 15, 22, 36, and 57 of treatment, 24-hour ambulatory ECGs were obtained, and multiple blood samples were taken for determination of amiodarone and desethylamiodarone plasma concentrations. All patients had at least 75% suppression of VPDs. The mean duration of therapy before the onset of antiarrhythmic effect was 13.2 days (range 1 to 36 days). Trough amiodarone and desethylamiodarone plasma concentrations at the time of onset of antiarrhythmic effect were 0.86 +/- 0.48 mg/L and 0.23 +/- 0.15 mg/L, respectively. Sixty-seven percent of patients responded at amiodarone concentrations below 1.0 mg/L. For each patient there was a progressive decrease in frequency of VPDs as both amiodarone and desethylamiodarone concentrations increased. Regression modeling indicated that both amiodarone and desethylamiodarone plasma concentrations explained significant variability in the frequency of VPDs, and amiodarone and desethylamiodarone plasma concentrations were highly correlated with each other. There was a trend for desethylamiodarone to explain more variability in frequency of VPDs than amiodarone.

Determination of unconjugated 3-methoxy-4-hydroxyphenylglycol by liquid chromatography for monitoring inhibition of monoamine oxidase activity in plasma

We describe a simple method for extracting 3-methoxy-4-hydroxyphenylglycol (MHPG) from plasma. The sample is applied to a 1-mL "Extrelut" column (EM Industries) and eluted 15 min later with ethyl acetate. After mixing the eluate with pentane and back-extraction into water, we inject 25 or 50 microL of the aqueous phase onto a Beckman 15 cm x 4.6 mm (i.d.) column packed with 5-micron ODS particles (Beckman). Peaks are detected with a coulometric detector. The resulting chromatogram is clean, with few extraneous peaks. The extraction recovery of MHPG is 55-60%, which allows for detection of as little as 0.2 microgram of the analyte per liter. The decrease in the concentration of MHPG in plasma of patients treated with phenelzine agrees with the decrease in monoamine oxidase activity in platelets of these patients.

Determination of unconjugated 3-methoxy-4-hydroxyphenylglycol by liquid chromatography for monitoring inhibition of monoamine oxidase activity in plasma

We describe a simple method for extracting 3-methoxy-4-hydroxyphenylglycol (MHPG) from plasma. The sample is applied to a 1-mL "Extrelut" column (EM Industries) and eluted 15 min later with ethyl acetate. After mixing the eluate with pentane and back-extraction into water, we inject 25 or 50 microL of the aqueous phase onto a Beckman 15 cm x 4.6 mm (i.d.) column packed with 5-micron ODS particles (Beckman). Peaks are detected with a coulometric detector. The resulting chromatogram is clean, with few extraneous peaks. The extraction recovery of MHPG is 55-60%, which allows for detection of as little as 0.2 microgram of the analyte per liter. The decrease in the concentration of MHPG in plasma of patients treated with phenelzine agrees with the decrease in monoamine oxidase activity in platelets of these patients.

The role of the laboratory in acute poisoning: case histories

We describe case histories and management of four patients poisoned with different compounds. The role of the laboratory, particularly of toxicological analysis, in the management of poisoned patients is examined.

Liquid chromatographic determination of mexiletine and tocainide in human plasma with fluorescence detection after reaction with a modified o-phthalaldehyde reagent

A liquid chromatographic procedure for the determination of mexiletine or tocainide in human plasma is described. Plasma, after the addition of a homologue of mexiletine or of tocainide, is extracted with dichloromethane. The extract is evaporated and reconstituted in a non-aqueous o-phthalaldehyde--mercaptoethanol reagent. An aliquot of the solution is chromatographed on a reversed-phase Ultrasphere-octyl column. The peaks are detected by fluorescence (lambda ex = 350 nm and lambda em = 445 nm). The fluorescent derivatives of the drugs and internal standards are stable at room temperature and give symmetrical single peaks. Use of fluorescamine as a reagent to prepare fluorescent derivatives of mexiletine and tocainide prior to chromatography is also evaluated.

Liquid chromatographic determination of inhibition of monoamine oxidase activity in platelet rich plasma of depressed patients treated with phenelzine

Monitoring platelet monoamine oxidase activity in plasma of depressed patients receiving monoamine oxidase inhibitors is used as an indicator of therapeutic dosage and efficacy. In this study enzyme activity in platelets vs platelet rich plasma was compared. An aliquot of platelet rich plasma (PRP) was incubated with 4-hydroxy-3-methoxy-benzylamine as substrate. After stopping the enzymatic reaction, m-hydroxybenzaldehyde was added to the mixture as internal standard. The reaction mixture was extracted with toluene to isolate vanillin, the deamination product of the substrate, and the internal standard. The toluene layer was collected and back extracted into dilute tetramethylammonium hydroxide. An aliquot of the aqueous layer was chromatographed on a non-silica resin base reversed phase column with an alkaline phase. The peaks were detected by an absorbance detector at 350 nm. There was no significant difference in the decrease of monoamine oxidase activity when determined using platelet rich plasma versus washed platelets.

Drug level monitoring: sedative hypnotics

Barbiturates and other traditional non-barbiturate sedative hypnotics are still extensively prescribed for the treatment of insomnia. There are a number of situations where identification or quantitative determination of these agents in biological fluids is required. Gas-chromatography offers highly sensitive and specific procedures for the determination of these compounds. The use of a nitrogen-specific detector allows a relatively simple sample preparation for sensitive detection and the use of capillary columns with bonded liquid phase allows separation of barbiturates without derivatization. In recent years liquid chromatography has also been extensively applied to the determination of these compounds. Sensitivity and selectivity of detection of barbiturates have been improved with the use of an alkaline mobile phase. Immunoassays for the determination of therapeutic concentrations of phenobarbital are very popular as the assays can be rapidly performed automatically. Use of these techniques has been extended for emergency detection of barbiturate overdose and for monitoring high-dose pentobarbital therapy.

Specificity of the combined dexamethasone suppression and TRH/TSH tests in melancholia

Subjects for this study were 61 acute psychiatric inpatients. Forty two (42) qualified for a RDC diagnosis of Major Depressive Disorder (MDD) and 19 for other disorders. After a 7-10 days drug withdrawal period patients were subjected to the dexamethasone suppression and TRH/TSH tests. TSH was measured using a RIA. Cortisol was measured using a CPB technique. Eighteen (18) of the 42 MDD patients and 1 of the 19 others had an abnormal DST (sensitivity 43%, specificity 94%). Twenty two (22) depressed patients and 4 others had a blunted TSH response (sensitivity 52%, specificity 79%). Thirteen (13) depressives and none of the others had abnormal responses to both tests (sensitivity 31%, specificity 100%). DST nonsuppression alone and blunted TSH response alone were not a function of severity of illness, sex, age of onset, family history or RDC subtype. The 13 MDD patients with the combined neuroendocrine abnormality were more severely depressed, had longer episodes of illness, were older and had a later age of onset of their first episode. Our results add support to the suggestion that serial neuroendocrine challenge studies might be of particular relevance and significance in the diagnosis and management of elderly psychotic depressed patients.

Liquid chromatographic determination of urinary metanephrines after pre-column oxidation to vanillin

Urine after the addition of phenylephrine as internal standard is hydrolyzed and passed through a disposable BondElut SCX column. After washing the column, metanephrines and the internal standard are eluted with dilute ammonia. The eluate is treated with periodate and extracted with toluene. The toluene layer is collected and phenols are extracted into dilute tetramethylammonium hydroxide. An aliquot of the aqueous layer is chromatographed on a nonsilica resin base reversed phase column with an alkaline mobile phase. The peaks are detected by an absorbance detector at 350 nm. There is a baseline separation of vanillin formed by metanephrines and of m-hydroxybenzaldehyde formed by phenylephrine. The procedure is linear from 0.2 mg to 10 mg of metanephrine per liter of urine. The procedure has a high degree of specificity as the commonly prescribed antihypertensive drugs and their metabolites do not interfere.

Colorimetric determination of acetaminophen

A colorimetric procedure for the emergency determination of acetaminophen in plasma is described. Acetaminophen is extracted into ethyl acetate at physiological pH to eliminate salicylate, amino acids and other polar compounds. The extract is treated with Fuller's earth to remove bilirubin and with anhydrous sodium sulphate to remove traces of aqueous droplets containing proteins or uric acid. The extract is back-extracted into carbonate and simultaneously treated with Folin--Ciocalteau reagent to produce a stable colour complex.

Liquid-chromatographic determination of nadolol in plasma

We describe a liquid-chromatographic procedure for determining nadolol in plasma. After an analog of nadolol is added as internal standard, the plasma sample is passed through a disposable BondElut C18 column. After several column washes, nadolol and the internal standard are eluted with methanol, and the eluate is evaporated and reconstituted with the mobile phase (acetonitrile/water, perchloric acid, and tetramethylammonium hydroxide). An aliquot of the extract is chromatographed on a non-silica resin-base reversed-phase column. The peaks are detected by fluorescence (lambda ex = 265 nm and lambda em = 305). Drug and internal standard are well resolved, and only a few extraneous peaks appear. The standard curve ranges from 10 to 400 micrograms/L. We are using this procedure to determine steady-state concentrations of nadolol in patients receiving various dosages of nadolol along with other types of antihypertensive drugs.

Liquid-chromatographic determination of nadolol in plasma

We describe a liquid-chromatographic procedure for determining nadolol in plasma. After an analog of nadolol is added as internal standard, the plasma sample is passed through a disposable BondElut C18 column. After several column washes, nadolol and the internal standard are eluted with methanol, and the eluate is evaporated and reconstituted with the mobile phase (acetonitrile/water, perchloric acid, and tetramethylammonium hydroxide). An aliquot of the extract is chromatographed on a non-silica resin-base reversed-phase column. The peaks are detected by fluorescence (lambda ex = 265 nm and lambda em = 305). Drug and internal standard are well resolved, and only a few extraneous peaks appear. The standard curve ranges from 10 to 400 micrograms/L. We are using this procedure to determine steady-state concentrations of nadolol in patients receiving various dosages of nadolol along with other types of antihypertensive drugs.