Pharmacokinetics of betamethasone in twin and singleton pregnancy

OBJECTIVE

The aims of the study were to compare the pharmacokinetics of betamethasone in singleton pregnancy with the pharmacokinetics in twin pregnancy and to assess the adrenal suppression produced by betamethasone.

STUDY DESIGN

We measured serial betamethasone and cortisol levels in 30 singleton and 21 twin pregnancies after the first dose of betamethasone and calculated the pharmacokinetic parameters for betamethasone including volume of distribution, half-life, and clearance. We also measured cord and maternal blood levels of betamethasone at the birth of infants of 13 singleton and 9 twin pregnancies.

RESULTS

The half-life of betamethasone in mothers with twin pregnancies was significantly shorter than that in mothers with singleton pregnancies (7.2 +/-2.4 versus 9.0 +/- 2.7 hours; P <.017). Clearance of betamethasone in the twin pregnancies appeared greater than in singleton pregnancies (8.4 +/- 6.4 versus 5.7+/- 3.1 L/h; P =.06) but did not reach statistical significance. Volume of distribution was similar in the two groups. Because the time between the last dose of betamethasone and birth varied widely (range, 2-158 hours), mothers with a longer interval after treatment tended to have a higher cord-to-maternal betamethasone ratio than did mothers with a shorter interval in both twin and singleton pregnancies. This finding indicated delayed fetal clearance, but the correlation was weak (R (2) = 0.29 for twins and 0.08 for singletons).

CONCLUSION

The shorter half-life of betamethasone in twin pregnancy than in singleton pregnancy may cause the level of betamethasone to be subtherapeutic for lung maturation in twin pregnancy.

Circadian time of morning light administration and therapeutic response in winter depression

BACKGROUND

We investigated a possible mechanism of action for the antidepressant response to light-phase advances of the circadian clock-by measuring the onset of melatonin secretion before and after light treatment in the morning or evening.

METHODS

Plasma melatonin was sampled in 42 patients with seasonal affective disorder, in the evening or overnight while depressed and after 10 to 14 days of light therapy (10 000 lux for 30 minutes) when symptoms were reassessed.

RESULTS

Morning light produced phase advances of the melatonin rhythm, while evening light produced delays, the magnitude depending on the interval between melatonin onset and light exposure, or circadian time (morning, 7.5 to 11 hours; evening, 1.5 to 3 hours). Delays were larger the later the evening light (r = 0.40), while advances were larger the earlier the morning light (r = 0.50). Although depression ratings were similar with light at either time of day, response to morning light increased with the size of phase advances up to 2.7 hours (r = 0.44) regardless of baseline phase position, while there was no such correlation for evening light. In an expanded sample (N = 80) with the sleep midpoint used as a reference anchor for circadian time, early morning light exposure was superior to late morning and to evening exposure.

CONCLUSION

The antidepressant effect of light is potentiated by early-morning administration in circadian time, optimally about 8.5 hours after melatonin onset or 2.5 hours after the sleep midpoint.

Effects of electroconvulsive therapy on plasma vasopressin and oxytocin

BACKGROUND

Animal studies suggest that vasopressin has cognitive-enhancing properties and oxytocin may have amnestic effects. A clinical report suggests that the acute increase in oxytocin-associated neurophysin predicts clinical response to electroconvulsive therapy (ECT) in depressed patients.

METHODS

Medication-free patients with major depression were randomized to receive right unilateral or bilateral ECT administered with electrical stimulus intensity at either just above seizure threshold or at 150% above seizure threshold. The associations between plasma vasopressin, oxytocin, ECT treatment parameters, clinical outcome, and cognitive effects were assessed.

RESULTS

The sample comprised 55 patients. At the second ECT, patients receiving ECT at 150% above initial seizure threshold had significantly greater increases in plasma vasopressin than patients receiving low-dose ECT (ps < .01-.04), with no effects of electrode placement. At the second and ninth ECT treatments, the vasopressin or oxytocin surges were not associated with clinical improvement, seizure duration, time to orientation, or memory test performance. There were inverse trend-level associations between the acute surge in oxytocin levels at the ninth ECT and clinical response, contradicting a report in the literature.

CONCLUSIONS

Overall, these findings do not support the hypothesis that diencephalic seizure propagation is central to the mechanism of action of ECT.

Two-way cell traffic between mother and fetus: biologic and clinical implications

The bilateral trafficking of nucleated cells between the fetus and the mother was studied using polymerase chain reaction (PCR)-based systems sensitive enough to detect 1 target cell in 100,000 background cells. Sixty-six mother-baby pairs were recruited; maternal and cord blood samples were collected at delivery for DNA extraction. Cell trafficking was studied in informative cases using PCR-genotyping of polymorphic regions in the beta-globin cluster, the glutathione S-transferase M1 locus and the angiotensin converting enzyme gene. In addition, Y-PCR was also used in conjunction with these systems for the detection of fetal cells in maternal circulation. Fetal cells were detected in maternal peripheral blood in 26 of 51 cases whereas maternal cells were detected in 16 of 38 fetal umbilical cord blood samples. The proportion of umbilical samples with detectable maternal sequences was much higher than previously reported. In the 28 cases informative for both mother and baby, there was no obvious correlation between the cell traffic from mother to baby as compared to that from baby to mother. These findings may have implications for the use of cord blood for bone marrow transplantation, the vertical transmission of infectious agents, and the physiology of the feto-maternal relationship.

A study of the possible etiologic association of Epstein-Barr virus with reactive hemophagocytic syndrome in Hong Kong Chinese

The herpes group of viruses, particularly Epstein-Barr virus (EBV), has frequently been implicated in the causation of reactive hemophagocytic syndrome (RHS) in the Western populations. EBV has also been implicated in the rare fulminant form of RHS occurring in Oriental children. However, our previous adult-predominant study indicated little clinical and serological evidence of EBV infection in patients with RHS in Hong Kong. In the present study, we further examined this issue using a more sensitive and specific technique for the demonstration of EBV, ie, in situ hybridization for EBV encoded RNA (EBER). The 43 Chinese patients studied were mostly adults with a mean age of 44 years, and a male to female ratio of 1.5:1. About two-thirds (28) of patients had associated malignant lymphoma at the time of diagnosis. Five patients had documented infection (typhoid fever 2; systemic candidiasis 1; adenovirus pneumonia 1; viral encephalitis 1), and two had systemic lupus erythematosus. EBER signals were detected in only 11 cases (25.6%). All positive cases were associated with malignant lymphoma, and the positive signals were exclusively localized to the lymphoma cells but not in the histiocytes. On comparing the results (11 of 28 cases positive; 39.3%) with our previous data on EBER-expression in malignant lymphomas in Hong Kong, no significant difference is observed in the frequency of EBV-positivity between the two groups of lymphomas. Thus, a definite pathogenetic link between EBV and lymphoma-associated RHS cannot be established. However, the overrepresentation of T and T/NK lineage lymphoma in this sample of lymphoma-associated with RHS (61%) versus nonselected cases of lymphomas (31%) suggests that it is the T and T/NK cell origin of the lymphoma rather than the EBV positivity that predisposes to RHS. Notwithstanding the previous findings, EBER in situ hybridization may still serve as a useful adjunct in the investigation of patients with RHS, because the presence of EBER-positive cells should raise a strong suspicion of an underlying malignant lymphoma.

Relationships between circulating catecholamines and low frequency heart period variability as indices of cardiac sympathetic activity during mental stress

Heart rate increases during psychological stress are the product of cardiac sympathetic activation and parasympathetic withdrawal. Levels of plasma epinephrine (E) and norepinephrine (NE) have a long history as indicators of cardiac adrenergic activity and, accordingly, generally increase in response to psychological challenge. Recently, several investigators have suggested that indices derived from power spectral analysis of heart period variability (HPV) also may provide estimates of cardiac sympathetic nervous system activity. These indices include power in the low frequency band (0.04-0.15 Hz, LF), and the ratio of low to high frequency (0.15-0.50 Hz, HF) power (LF/HF). The relationship between spectral and neurohumoral indices during psychological stress has not been investigated. This issue was addressed by studying spectrally defined measures of HPV and levels of plasma E and NE in 34 normal subjects who participated in a study of responsiveness to a psychologically challenging arithmetic task. Heart rate (HR), LF and HF power, the LF/HF ratio, and blood pressure were measured during the 5-minute baseline and 5-minute task periods. Integrated samples of forearm venous blood were collected for both periods. E and NE were analyzed by high performance liquid chromatography. The task produced significant increases in HR, systolic and diastolic pressures, and NE. Of the 12 Pearson correlation coefficients used to examine the relationships between power spectral measures and catecholamines for the baseline, task, and delta values, none achieved statistical significance, suggesting little relationship between neurohumoral and spectral estimates of cardiac sympathetic activity. We conclude that under conditions of psychological stress, LF power provides no useful information about cardiac sympathetic activity, both because power in this frequency band falls whereas HR rises and because there is no relationship between LF power and plasma NE.

Fluphenazine plasma levels, dosage, efficacy, and side effects

OBJECTIVE

The authors sought to determine whether fluphenazine dose or plasma level predicts clinical improvement or side effects during acute treatment.

METHOD

Oral fluphenazine was given in fixed, randomized, double-blind doses (10, 20, or 30 mg/day) for 4 weeks to 72 inpatients with acute schizophrenic exacerbations. Outcome measures included percentage improvement in ratings of positive symptoms (hallucinations, delusions, and thought disorder), percentage improvement in negative symptoms, and maximum score for extrapyramidal symptoms. Response was defined as an improvement in positive symptoms of 40% or more.

RESULTS

The 42 responders had a shorter duration of illness, less chronic course, and lower rate of akathisia. Plasma level and dose did not differentiate responders and nonresponders, but they did predict percentage improvement in positive symptoms within the responder subgroup. Akathisia was more common and extrapyramidal symptoms were more severe at higher plasma levels.

CONCLUSIONS

Responders showed the greatest improvement at fluphenazine plasma levels above 1.0 ng/ml and doses above 0.20-0.25 mg/kg per day. Since the literature suggests that optimal plasma levels are similar during acute and maintenance treatment, monitoring of plasma levels may thus be useful. Conditions for applying the "responder-only" analytic strategy in future studies are discussed.

A study of the association of Epstein-Barr virus with Burkitt's lymphoma occurring in a Chinese population

There is a strong association (approximately 95%) of endemic Burkitt's lymphoma with Epstein-Barr virus (EBV), whereas the association is weak for the sporadic form occurring in Western countries (approximately 15%). In the Middle East, North Africa and South America, 60-80% of Burkitt's lymphomas harbour EBV. These epidemiological differences suggest that either the endemicity of EBV or socio-economic conditions, or both, may influence the pathogenetic role of EBV in Burkitt's lymphoma. Since only meagre data are available on Asians, this study was performed to address this issue by studying cases from Hong Kong, where EBV seroconversion occurs in the first few years of life but the socio-economic conditions approach those of Western countries. In situ hybridization for EBV encoded RNAs (EBERs) was performed on paraffin sections of 18 cases of Burkitt's lymphoma. Labelling of the neoplastic cells was detected in five cases (27.7%). In contrast, among 54 cases of B-cell lymphomas of various subtypes studied for comparison, signals for EBER were detected in only one case each of T-cell-rich large B-cell lymphoma, anaplastic large cell lymphoma and Reed-Sternberg-like cells occurring in B-cell chronic lymphocytic leukaemia/small lymphocytic lymphoma. The strong labelling with oligo-dT probe (which hybridized with the polyadenylated ends of mRNA) in all cases suggested that the negative results were genuine and not due to poor preservation of RNA in the tissues. Thus, among B-cell neoplasms occurring in Chinese, Burkitt's lymphoma shows a statistically stronger association (P < 0.01) with EBV than with other types of B-cell lymphoma.(ABSTRACT TRUNCATED AT 250 WORDS)

A time correlation study between reflectance spectroscopic cutaneous vasoconstriction and plasma corticosteroid concentration

Although cutaneous vasoconstriction assays are used as a primary screen for ranking the in vivo efficacy of new corticosteroids and in vivo human drug delivery studies, little is known about the relationship between the blanching reaction and corticosteroid tissue or plasma concentrations. We measured cutaneous vascular reactions in five volunteers, using an improved reflectance spectroscopic method, and a sensitive radioimmunoassay technique was employed to measure plasma betamethasone concentrations. Using a specially developed betamethasone-17-valerate patch prepared in BIO-PSA, constant corticosteroid release was ensured, and correlations between cutaneous blanching and plasma corticosteroid concentrations were calculated. Maximal skin blanching was documented 12 h post-application, whereas plasma corticosteroid concentrations peaked later, at 32 h post-application, when a paradoxical telangiectatic vasodilatation occurred. At 72 h post-application, when the plasma corticosteroid concentration was still above the 12 h level, this paradoxical vasodilatation was maximal. The corticosteroid-induced vascular reactions were mainly due to arterial haemoglobin (Oxy Haem), and both vasoconstriction and vasodilatation were related to changes in Oxy Haem. Our results suggest a dual, probably both time and concentration related, interaction between corticosteroids and dermal vessels in which lower concentrations at 6-12 h exposure caused vasoconstriction, but as the exposure time increased (> or = 24 h) paradoxical vasodilatation was induced, although plasma corticosteroid concentrations were still rising.

An endogenous aminoenkephalinase inhibitor: purification and characterization of Arg0-Met5-enkephalin from bovine striatum

Arg0-Met5-enkephalin (Arg0-MEK) was isolated from bovine striatum and purified to homogeneity. The peptide was extracted with trichloroacetic acid, followed by column chromatography successively on Bio-Sil C8, semipreparative HPLC Radial-Pak C18, fast protein liquid chromatography (FPLC) Mono S, HPLC Ultrasphere-ODS, Supelco C18, Lichromsorb C18, and mu Bondapak C18. The peptide content was followed by radioimmunoassay with an antibody against synthetic Met-enkephalin. For each of the six HPLC and FPLC systems, the elution time of the immunoreactive fractions coincided exactly with that of synthetic Arg0-MEK. The purified peptide showed a highly homogeneous profile in three different analytical HPLC systems. Its retention time and three-dimensional UV spectrum were identical to those of the synthetic Arg0-MEK. The structure of the purified material was identified by microsequencing as the hexapeptide Arg-Tyr-Gly-Gly-Phe-Met. Ninety percent of the purified peptide was in oxidized form containing equimolar amounts of Met-(R)- and Met-(S)-sulfoxide. The reduced Arg0-MEK inhibited aminoenkephalinase with a Ki of 2.2 microM, and its sulfoxide analogue inhibited it with a Ki of 8.9 microM. The reduced or oxidized peptide suppressed the electrically induced contraction of rat vas deferens with an ED50 of 5 microM, and the effect could be reversed by equimolar naloxone. Our data indicate that Arg0-MEK is an immediate Met-enkephalin precursor and an endogenous inhibitor.

Hypoxia after prenatal cocaine attenuates striatal dopamine and neurotrophic activity

We have previously shown that newborn rabbits exposed to cocaine prenatally have an altered cardiorespiratory response to hypoxia. We report the effect of postnatal hypoxia on brain DA and neurotrophic activity in New Zealand White rabbit pups (n = 41) born to cocaine-exposed does (30 mg/kg/day SC from days 7-15 of a 32-day gestation = COCaine) and control does (sterile H2O = VEHicle). Four to 6-day-old pups were exposed to 20 min of room air (0.21 fractional inspired oxygen tension, FIO2). One third of each group was then exposed to 20 min of either 0.15 (moderate hypoxia) or 0.08 (severe hypoxia) FIO2. Immediately following hypoxic challenge the pups were sacrificed. Striatal tissue extracts were subsequently assessed for DA and striatal trophic activity by monitoring the number of neuron specific enolase immunoreactive (NSEir) cells in mesencephalic culture following incubation with striatal extracts. Increasing the severity of hypoxia increased DA content (p < 0.005), but reduced DA activity (p < 0.0001) and trophic activity (p < 0.001). Cocaine exposure reduced striatal DA (p < 0.005) as well as NSEir (p < 0.001) in all conditions relative to vehicle-treated controls. These data suggest that prenatal cocaine exposure enhances the vulnerability of the DA system to the stress of hypoxia, possibly through alterations in neurotrophic activity.

Cerebrospinal fluid from patients with Parkinson's disease alters the survival of dopamine neurons in mesencephalic culture

We have previously demonstrated that extracts of striatal tissue from patients with Parkinson's disease (PD) increase the survival of dopamine neurons in mesencephalic cultures relative to striatal extracts from control patients. In the present study, ventricular cerebrospinal fluid (vCSF) from patients with PD, Alzheimer's disease (AD), and age-matched controls was similarly assessed. vCSF samples were separated into > 10-kDa and < 10-kDa fractions. Cultures incubated with the > 10-kDa fractions from PD and AD patients contained 73 and 13%, respectively, more tyrosine hydroxylase immunoreactive neurons than cultures incubated with vCSF from age-matched controls. This trophic activity was positively correlated with the trophic activity present in striatal extracts from the same patients. The < 10-kDa vCSF fractions from all patient groups inhibited culture growth. These data suggest that the trophic environment in the striatum is altered in PD and can be successfully monitored in CSF.

Plasma concentrations of betamethasone after topical application of betamethasone 17-valerate: comparison with oral administration

Plasma concentrations of betamethasone were measured by r.i.a. after oral administration of 0.6 mg betamethasone and topical application of betamethasone 17-valerate in the same five healthy subjects. Betamethasone 17-valerate was prepared as a suspension in medical grade pressure sensitive adhesive and applied to a 100 cm2 area on the back for 28 h. Mean maximum plasma concentrations were 5.0 and 0.24 ng ml-1 and mean AUC values were 75.4 and 7.74 ng ml-1 h after oral and topical administrations, respectively. The mean plasma elimination half-life of betamethasone after the removal of topical betamethasone 17-valerate was 16.6 h which was twice that after oral administration, 8.1 h. Betamethasone 17-valerate may require application to the skin more than twice daily.

Alterations in striatal neurotrophic activity induced by dopaminergic drugs

The administration of dopaminergic drugs induces a variety of compensatory responses ostensibly designed to reinstate normal dopamine (DA) tone. We have hypothesized that drug-induced alterations in striatal-derived neurotrophic activity contributes to these compensatory processes. This phenomenon has been studied by examining the growth of mesencephalic cultures incubated with cell-free extracts of striatal tissue taken from patients or rats treated with various drugs. Our results reveal that reducing striatal DA tone by administering the DA antagonist haloperidol, the DA neurotoxin 6-hydroxydopamine, or as occurs naturally in Parkinson's disease, increases striatal trophic activity. Conversely, increasing striatal DA tone by administering the indirect DA agonists amphetamine or levodopa reduces trophic activity in the striatum. Kainic acid lesions of the striatum similarly reduce this trophic activity. The implications of these drug-induced alterations in trophic activity are discussed and reviewed.

Effect of cocaine in early gestation on striatal dopamine and neurotrophic activity

Prenatal exposure to the dopamine (DA) agonist cocaine, even if limited to early gestation, is associated with impaired developmental outcome in the human infant. We investigated the possible role of neurotrophic factors in this process by evaluating 4- to 6-d-old New Zealand White rabbit pups (n = 14) born to cocaine-exposed does (30 mg/kg/d s.c. from days 7 to 15 of a 32-d gestation) and control does (sterile H2O). Cocaine exposure reduced striatal dopamine by 46% (t = 2.31; p < 0.05) and striatal 3,4-dihydroxyphenyl acetic acid by 49% (t = 2.44; p < 0.05). The number of neuron-specific enolase immunoreactive neurons in mesencephalic cultures incubated with striatal extracts from pups exposed to cocaine was reduced by 61% relative to the effect of striatal extracts from control pups (t = 4.84; p < 0.01). The present results suggest that the reduction in striatal dopamine observed may result from a cocaine-induced decrease in striatal trophic activity.

Post-dexamethasone cortisol levels and computerized tomographic findings in manic patients

The relations of post-dexamethasone cortisol levels to computerized tomography (CT) scan findings of lateral and third ventricle size and cortical sulcal prominence rated separately for frontal and parieto-occipital distributions were examined in 15 manic patients. Failure to suppress endogenous cortisol after a dexamethasone challenge was associated with larger third ventricles, but not to any of the other CT scan measures.

Geographical variation in prevalence of hepatitis B virus DNA in HBsAg negative patients

AIMS--To study the geographical variation of the prevalence of hepatitis B virus (HBV) DNA in hepatitis B surface antigen (HBsAg) negative subjects. METHODS--A nested polymerase chain reaction (PCR) assay was used to amplify the core region of HBV. The assay was able to detect 10 molecules of a full length HBV plasmid. RESULTS--When applied to HBsAg negative paraffin wax embedded liver samples from Italy, Hong Kong, and the United Kingdom, a geographical variation in the prevalence of HBV-DNA positivity was noted. Two of 18 (11%) of Italian samples and 2/29 (6.9%) of Hong Kong samples were positive for HBV-DNA while none of the 70 cases from the United Kingdom was positive by nested PCR. Contamination by plasmid DNA was excluded using a novel method based on heteroduplex formation. One HBV-DNA positive case had idiopathic chronic active hepatitis, but the diagnoses in the other three HBV-DNA positive cases did not suggest any aetiological connection between HBV-DNA positivity and liver pathology. CONCLUSIONS--HBV-DNA could be detected in the liver tissues of a proportion of HBsAg negative subjects. The prevalence of such cases is related to the endemic rate of a geographical region. The use of HBV PCR on paraffin wax embedded tissues will be valuable for future studies on the molecular epidemiology of HBV.

Detection of hepatitis B pre-core mutant by allele specific polymerase chain reaction

AIM

Development of a specific polymerase chain reaction (PCR) assay for detection of the pre-core, stop codon, mutant of hepatitis B virus (HBV).

METHODS

PCR primers, specific at the 3'-end for nucleotide 1896 of either the pre-core, stop codon, mutant or wild type HBV, were synthesised using published sequence data. Positive control templates for both types of virus were synthesised by the PCR, incorporating sequences specific for each virus type at the appropriate position. These templates were used to optimise the specificity of the procedure. Formalin fixed, paraffin wax embedded human tissue from acute or fulminant HBV hepatitis from Hong Kong or Oxford was then investigated for presence of mutant or wild type virus. The HBV DNA was amplified from this tissue using a two step procedure, with an initial amplification phase followed by a second diagnostic phase on optimally diluted target DNA.

RESULTS

Specific detection of mutant or wild type HBV was achieved. An important factor in determining specificity was the temperature of annealing, 70 degrees C proving to be highly specific. To overcome the inherent variation of target copy number in clinical samples and to provide an intrinsic positive control, it was important to generate and standardise the amount of target HBV used for the specific PCR. Two cases of fulminant hepatitis and four cases of acute hepatitis from Hong Kong, and one case of fulminant hepatitis from Oxford, contained only wild type HBV, with no evidence of a mutant virus.

CONCLUSION

This method can be applied to FFPE tissues. It is rapid, non-radioactive, and specific for the stop codon mutation at nucleotide 1896 of HBV. Preliminary investigation of a small number of cases of fulminant hepatitis from Oxford and Hong Kong showed only wild type virus. The result differs from results published from Japan and Israel.

Integration of human papillomavirus types 16 and 18 in cervical adenocarcinoma

AIMS

To determine which type of human papillomavirus (HPV) is associated with cervical adenocarcinoma and whether the virus was integrated or episomal in two continents.

METHODS

Biopsy specimens from the UK (n = 16) and South Africa (n = 22) were analysed by non-isotopic in situ hybridisation (NISH) for HPV types 6, 11, 16, 18, 31, 33, and 35 on archival biopsy specimens using digoxigenin labelled probes.

RESULTS

A total of 20 adenocarcinomas (53%) from both groups contained HPV DNA. In the UK group, seven and four cases contained HPV 18 (44%) and 16 (25%) respectively. In the South African group, nine cases contained HPV 18 (41%) while HPV DNA was not detectable in the other 13 cases. Hence HPV 18 was present in 80% of HPV positive adenocarcinomas.

CONCLUSIONS

The HPV 16 or 18 genome was integrated in all viral positive cases. In two cases HPV 18 was also present in an episomal form. These data indicate that HPV integration is common to cervical adenocarcinoma in two continents by the same methodology. The lower prevalence of HPV 18 detection in the South African group may have been due to the presence of other or unsequenced HPV types.

Dexamethasone suppression test in children with major depressive disorder

The authors report a study of 24-hour serial cortisol determinations, measured during baseline and after the administration of 0.25 and 0.5 mg of dexamethasone in a sample of predominantly outpatient children with major depressive disorder, nonaffective psychiatric controls, and normal controls. In this sample, 24-hour baseline cortisol and the dexamethasone suppression test (DST) do not discriminate between the three groups. In addition, the authors measured 24-hour serum dexamethasone levels. There were no significant between group differences in serum dexamethasone. These results raise questions as to the utility of this test in the diagnosis of affective disorders in children. Possible reasons for the discrepancies in the dexamethasone suppression test results between in- and outpatient studies are discussed.

Heteroduplex formation as a means to exclude contamination in virus detection using PCR

Images

Levodopa reduces the growth promoting effects of striatal extracts on rostral mesencephalic tegmentum cultures

Rats with unilateral 6-hydroxydopamine lesions (6-OHDA) of the mesencephalon and vehicle controls (SHAM) were chronically treated with carbidopa (CD) or CD plus levodopa (CD/LD) for 18 days. Seventy-two hours following the last treatment, ipsilateral striata, contralateral striata, and cerebellums from each treatment group were homogenized separately and the supernatant extracts were incubated with rostral mesencephalic tegmentum cultures. As indices of growth-promoting activity (GPA), number of viable neurons and their process lengths were measured 40 h later. In all cultures exposed to striatal extracts, the 6-OHDA lesion was associated with greater GPA than the SHAM extracts. CD/LD consumption reduced this GPA in a dose-dependent fashion in both the lesioned and the SHAM animals. These data suggest that denervation of the striatum enhances the production of a striatally derived neurotrophic factor, the production of which is sensitive to levodopa. Chronic levodopa treatment in Parkinson's disease may therefore contribute to disease progression by reducing the compensating effects of this neurotrophic factor on remaining mesencephalic neurons.

Serial dexamethasone suppression tests and plasma dexamethasone levels. Effects of clinical response to electroconvulsive therapy in major depression

Serial 1-mg dexamethasone suppression tests with concurrent plasma dexamethasone assessments were conducted in 58 patients with endogenous depression treated with electroconvulsive therapy (ECT). Plasma cortisol levels decreased significantly from pretreatment to immediately posttreatment, and they declined further during the first week after the ECT course, when patients remained drug free. Plasma dexamethasone levels showed an opposite pattern of progressive increases over these three time points. The progressive changes in plasma dexamethasone and cortisol levels seen during the week after ECT indicate that alterations in the bioavailability of dexamethasone and in hypothalamic-pituitary-adrenal axis function may be incomplete immediately after the ECT course. This may partly account for previous inconsistencies in serial dexamethasone suppression test findings with this treatment modality. The major finding was that clinical response was associated with increased plasma dexamethasone levels, whereas changes in cortisol levels were independent of clinical outcome. With ECT, changes in plasma dexamethasone levels may be more related to changes in clinical state than changes in postdexamethasone cortisol levels. The extent to which clinical recovery with other treatments in depression is associated with altered bioavailability of dexamethasone and perhaps other compounds is unknown and in need of investigation.

The potential use of a dopamine neuron antibody and a striatal-derived neurotrophic factor as diagnostic markers in Parkinson's disease

The cerebral spinal fluid (CSF) of patients with Parkinson's disease (PD) contains an antibody that immunocytochemically reacts with dopamine (DA) neurons in the substantia nigra (SN). This antibody was found in 78% of the CSF samples taken from patients with clinical PD. In contrast, only 3% of the CSF samples taken from control patients or patients with neurologic symptoms other than PD possessed this antibody. The production of this antibody might contribute to disease progression but does not appear to be the etiologic factor responsible for PD. In other experiments, concentrates of the CSF of patients with PD enhanced growth of mesencephalic cultures relative to control CSF. Both the antibody and the growth-promoting activity found in CSF are associated with degeneration of the SN and might therefore be useful as potential diagnostic markers for PD.

Effect of extended depot fluphenazine treatment and withdrawal on social and other behaviors of Cebus apella monkeys

To examine whether or not prolonged exposure to a depot neuroleptic has either residual or "tardive pathological" effects on normal behavior, 38 Cebus apella monkeys were observed daily for 108 weeks. The issue of stress influencing such effects was also addressed. During weeks 25-48 half of the monkeys received 0.22 mg/kg fluphenazine decanoate, IM, every 3 weeks, with the dose increased to 0.33 mg/kg during weeks 49-72. Behavioral measures were combined to form composite behavioral variables which quantify four major aspects of behavior: self- and environment-directed behavior, affiliation, aggression, and normal locomotor activity. Mean plasma fluphenazine levels at 48 h post-injection were 0.13 (+/- 0.03) ng/ml for injections 3-8 and 0.24 (+/- 0.07) ng/ml for injections 11-16. The pre-study null hypothesis that the four major aspects of behavior would not be adversely affected by this treatment during the drug-discontinuation phase of the study (weeks 73-108) was not statistically negated. There were highly significant decreases in self- and environment-directed behaviors and affiliation during the treatment periods, implying that treatment may contribute to the negative symptoms of treated schizophrenics. Stress reduced the above effects. Aggression showed some increase during early drug discontinuation, accentuated by stress. Recovery of normal (baseline) behavioral scores began by week 7 after the last treatment. Mild (bucco-lingual) tardive dyskinesias persisted in 30% of the animals for a prolonged time.

Single-dose pharmacokinetics of fluphenazine after fluphenazine decanoate administration

Fluphenazine decanoate is commonly used as part of maintenance treatment of schizophrenia, but its pharmacokinetics are poorly understood. We administered a single intramuscular dose of fluphenazine decanoate to nine patients and found that plasma fluphenazine level did not decline to 50% of the peak level by day 26 in any of the patients. This means that it has a long half-life measurable in months rather than weeks.

Acute dystonia during fixed-dose neuroleptic treatment

Eighty-six patients with acute psychotic exacerbations were treated with fixed dosage regimens of oral fluphenazine up to 10-30 mg/day in randomized, double-blind studies. Dystonic reactions occurred in 33.8% of the subjects at risk. Of these, 58% occurred by the third day, 88% by the fourth day, and 100% by the ninth day of treatment; most occurred later in the interdose interval. Significant predictors of dystonic reactions were higher fluphenazine mg/kg dosage and younger age. There was a trend toward a lower risk of dystonia in patients who received amobarbital sodium for agitation. Results are discussed in relation to possible mechanisms of neuroleptic-induced dystonia.

Application of the immunoperoxidase technique to cell block preparations from fine needle aspirates

Immunocytochemistry on fine needle aspiration (FNA) material has been mainly performed on cytologic preparations; there have been few reports on the use of FNA cell blocks. This study compared the intensity scores of immunoperoxidase staining on FNA cell block preparations from 21 breast, 12 thyroid and 10 lymph node aspirates with the scores on the corresponding surgically excised specimens. FNA materials for cell blocks were fixed in formalin and embedded in agar. Ten commercially available antibodies forming three panels were studied using standard peroxidase-antiperoxidase and avidin-biotin complex techniques. In general, the staining results on the FNA cell block sections agreed with those on the surgical specimens; in addition, there were fewer aberrant positive staining results and much less background staining in the cell block sections. These phenomena were most striking with the cytokeratin antibodies. It is concluded that immunoperoxidase staining on FNA cell block preparations is reliable; the advantages of the use of cell block sections as opposed to smears are discussed.

Direct radioimmunoassay procedure for plasma dexamethasone with a sensitivity at the picogram level

A simple radioimmunoassay (RIA) for the direct quantitation of plasma dexamethasone (DEX) at the picogram level has been developed. An antiserum with high specificity and avidity was obtained by the immunization of a carefully synthesized dexamethasone-21-succinyl-thyroglobulin with a high incorporation ratio. As little as 1 pg of DEX in 50 microL of plasma sample can be detected directly by this RIA without extraction and other purification procedures. Intra- and interassay coefficients of variation were 2.1 and 3.3% for plasma levels at 2.93 ng/mL or 2.3 and 7.2% for plasma levels at 0.88 ng/mL. Blank values for plasma of normal or pre-DEX patients were always under the detection limit (20 pg/mL). Excellent linearity (r = 0.9991-0.9999) was demonstrated between the serial dilutions of six plasma samples and their corresponding DEX concentrations. In single-dose DEX (0.25-1 mg) pharmacokinetic studies, plasma DEX was consistently detectable up to 24 h post dose. Compared with existing methods, this direct RIA demonstrates superior performance with regard to simplicity, sensitivity, specificity, and reproducibility. It also enables high sample throughput and has proven robust in our hands. This assay should be readily transferable to other laboratories for clinical or research purposes.

Anaplastic large cell Ki-1 lymphoma. Delineation of two morphological types

This report describes 16 cases of the recently recognized anaplastic large cell Ki-1 lymphoma. The disease showed a male:female ratio of 2.2:1 and a bimodal age distribution with peaks in the third and eighth decades. The clinical presentation was highly variable, with lymph node, skin, bone and gastrointestinal tract being the most commonly affected sites. The lymph nodes usually showed subtotal or sinusoidal involvement, and parenchymal fibrosis was common. The large neoplastic cells were almost invariably admixed with many reactive small lymphocytes, histiocytes and/or neutrophils. Two cytological types could be delineated: type I (pale cell, four cases) consisted of large polygonal cells with distinct pink-staining cell membrane and pale cytoplasm and pleomorphic nuclei showing marked chromatin clearing; and type II (basophilic cell, 12 cases) consisted of round or oval cells with basophilic cytoplasm and/or paranuclear pale hof, pleomorphic nuclei often reniform or lobulated and with frequent multinucleated wreath-like and Reed-Sternberg-like cells. Immunohistochemical studies showed that nine cases (56.3%) exhibited a T-cell phenotype, three cases (18.8%) each exhibited a B-cell or null-cell phenotype, while one case exhibited both T- and B-cell markers. Cutaneous involvement at presentation was associated with a favourable outcome, and spontaneous regression was common. For patients with non-cutaneous presentation, the prognosis was relatively good for young patients treated with aggressive chemotherapy, but was grave for old patients.

Plasma dexamethasone and cortisol levels in depressed outpatients

We investigated the 1-mg dexamethasone suppression test (DST) in 41 outpatients with major depressive disorder assessing the role of dexamethasone blood level, age and basal cortisol on DST results. Non-suppressors (approximately 25% of patients) had lower dexamethasone levels, and post-dexamethasone cortisol was negatively correlated with plasma dexamethasone; these findings were more significant after covarying out age and basal cortisol, factors that were also significantly associated to non-suppressors. A subgroup of patients (n = 19) also had 0.75-mg and 2.0-mg DST to evaluate whether a threshold dexamethasone blood level existed; a dexamethasone blood level greater than 1.5 ng/ml converted all non-suppressors to suppressors. Implications of these findings are discussed.

Response of the melatonin cycle to phototherapy for Seasonal Affective Disorder. Short note

It is well-established that human nocturnal melatonin secretion is suppressed by presentation of artificial light greater than 2,000 lux, a level that is also therapeutically effective in alleviating winter depression symptoms of Seasonal Affective Disorder [SAD]. Furthermore, early-morning bright light induces phase advances of the melatonin cycle in SAD patients (Lewy et al., 1987a). The functional significance of melatonin in SAD remains unclear. With plasma melatonin sampled at 20-min intervals in a series of overnight studies, we found marked phase delays of the cycle, relative to that previously reported for normals, in 4/5 depressed SAD patients. 2,500 lux light exposure at 6-8 a.m. resulted in exponentially declining melatonin levels that approached low daytime baselines within two hours (t1/2 = 45.52 min). All five patients showed clinical remissions as well as phase advances of the melatonin cycle of 0.75 to 3.27 hours (mean, 1.94 +/- 0.84 hours) after one week of daily exposure from 6-8 a.m. and p.m. These results suggest that the combination of early morning and early evening light exposures induces circadian phase adjustments similar to those of morning light alone, by impacting a photosensitive interval when, in SAD, melatonin secretion overshoots its normal nocturnal phase.

A highly sensitive and specific radioimmunoassay for quantitation of plasma fluphenazine

Antisera of high sensitivity and selectivity were obtained from rabbits immunized with conjugates of hemisuccinylated fluphenazine and porcine thyroglobulin. The antiserum selected (titer 1:6000) for the development of the RIA was obtained after a priming dose and a single iv booster injection three months later. This antiserum had negligible crossreactivity with known available metabolites of fluphenazine (FPZ) and an affinity constant of 2 X 10(10) L/mol. Tritiated FPZ was further purified by HPLC and used as a ligand. The method detects as little as 20 pg/mL of plasma (4 pg/RIA tube) after 1 mL of plasma is extracted. The extraction was performed at a basic pH with heptane: isoamyl alcohol (99:1); the solvent was then back extracted using an acetic phosphate buffer. Recoveries were uniformly high (88.6 +/- 2.1%), and this aqueous buffer extract was used directly in the RIA procedure. The assay has intra- and interassay coefficients of variation of 5.8 and 8.2%, respectively, in a plasma concentration of 95 pg/mL. Results using this procedure have been cross validated against an HPLC procedure (r = 0.952, slope = 1.032, intercept = 0.009, n = 18). In a single-dose FPZ study (10 mg, po), plasma FPZ levels in 25 normal volunteers could be monitored greater than 48 h post dose. Single plasma level profiles, after an initial injection of 12.5 mg of FPZ decanoate, could be measured greater than 36 d, and, in some cases, up to 100 d post dose.

Dexamethasone suppression test and plasma dexamethasone levels in bulimia

A 1-mg dexamethasone suppression test (DST) was carried out in 66 women with bulimia and in 26 age- and sex-matched controls. Blood samples were obtained at 4 PM on the day following dexamethasone ingestion, and levels of cortisol and of dexamethasone in the plasma were measured. Thirty-two percent of the patients vs only 7% of the controls had plasma cortisol levels of 140 nmol/L (5 micrograms/dL) or greater following the DST (a positive DST). The plasma levels of dexamethasone varied substantially, and there was a significant inverse relationship between the plasma level of cortisol and that of dexamethasone. Patients with positive DST results had lower levels of plasma dexamethasone than did those with negative DST results, and the mean plasma level of dexamethasone was lower in the bulimic group than in the control group. These results suggest that factors other than a disturbance of hypothalamic-pituitary-adrenal activity may contribute to positive DST results in bulimia.

Observations on N alpha-deacetylation of model amino acids and peptides: distribution and purification of a specific N-acyl amino acid releasing enzyme in rat brain

N alpha-Acyl amino acid releasing enzyme (NAARE), an enzyme cleaving acetylMet-Ala at the Met-Ala bond was purified from rat brain cytosol to apparent homogeneity by salt precipitation, gel filtration, and several steps of ion exchange. Levels of NAARE exceeded acylase measured with acetylmethionine in all brain regions and subcellular fractions examined: 60% was associated with cytosol and the remainder with debris or the crude nuclear and mitochondrial-synaptosomal subfractions. Activity was highest in pituitary and was approximately 0.5-0.6 that of liver or kidney. The purified enzyme preferentially hydrolyzed acetylmethionyl peptides: Km for acetylMet-Ala was 0.93; Vmax, 3.5 nmol-1 (kcat, 1185) with pH optimum of 8.9 as compared with 8.2 for acylases measured in cytosol. The purified enzyme was devoid of acylase and common exo- and endopeptidase contamination. Structure-activity relationships examined with synthetic formylated or acetylated peptides indicated no significant effects for di- or tripeptides if the second substituent was Ala, Ser, Asn, or Thr, but the activity was reduced 0.5-fold for Leu, a branched-chain amino acid. No hydrolysis was observed for polypeptides with five or more residues having N-terminal acetylated Tyr (enkephalin) or Ser (alpha-melanocyte-stimulating hormone, thymosin alpha 1), supporting the notion that the enzyme plays a role only in turnover of smaller peptides formed perhaps as a result of endopeptidase cleavage of proteins or polypeptides containing acetylated Met at the N terminus.