Identification of potential stroke targets by lentiviral vector mediated overexpression of HIF-1 alpha and HIF-2 alpha in a primary neuronal model of hypoxia

The identification of genes differentially regulated by ischemia will lead to an improved understanding of cell death pathways such as those involved in the neuronal loss observed following a stroke. Furthermore, the characterization of such pathways could facilitate the identification of novel targets for stroke therapy. We have used a novel approach to amplify differential gene expression patterns in a primary neuronal model of stroke by employing a lentiviral vector system to specifically bias the transcriptional activation of hypoxically regulated genes. Overexpression of the hypoxia-induced transcription factor subunits HIF-1 alpha and HIF-2 alpha elevated hypoxia-mediated transcription of many known HIF-regulated genes well above control levels. Furthermore, many potentially novel HIF-regulated genes were discovered that were not previously identified as hypoxically regulated. Most of the novel genes identified were activated by a combination of HIF-2 alpha overexpression and hypoxic insult. These included several genes with particular importance in cell survival pathways and of potential therapeutic value. Hypoxic induction of HIF-2 alpha may therefore be a critical factor in mediating protective responses against ischemic injury. Further investigation of the genes identified in this study may provide increased understanding of the neuronal response to hypoxia and may uncover novel therapeutic targets for the treatment of cerebral ischemia.

Genome of Geobacter sulfurreducens: metal reduction in subsurface environments

The complete genome sequence of Geobacter sulfurreducens, a delta-proteobacterium, reveals unsuspected capabilities, including evidence of aerobic metabolism, one-carbon and complex carbon metabolism, motility, and chemotactic behavior. These characteristics, coupled with the possession of many two-component sensors and many c-type cytochromes, reveal an ability to create alternative, redundant, electron transport networks and offer insights into the process of metal ion reduction in subsurface environments. As well as playing roles in the global cycling of metals and carbon, this organism clearly has the potential for use in bioremediation of radioactive metals and in the generation of electricity.

A general dental practice research network: impact of oral health in general dental practice patients

OBJECTIVE

To measure the subjective impact of oral health in a group of patients attending general dental practices in the North West of England and to investigate the attributes of dentists and practices in order to examine how such attributes might relate to patients' subjective perceptions of oral health.

DESIGN

Fifteen general dental practices conducting a simultaneous survey of attending patients and 15 practitioners from these practices providing information about their attitudes to treatment, prevention and various aspects of their surgery.

SETTING

General dental

OUTCOME MEASURES

Patient subjective impact scores. Relationships between practice and practitioner variables and patients' subjectively perceived oral health.

RESULTS

Fifteen practitioners with diverse practice attributes provided data on 718 patients. The mean total oral health impact score was 18.4. Twenty two per cent of patients had experienced pain in the four weeks before the survey and 11% had been unable to chew some foods. Fifty five per cent of the surveyed population had, in the previous year, worried about the appearance of their mouth and 65% had worried about their oral health in general. Dentists' beliefs were related to patient impact scores but practice attributes were not significantly associated with patients' impacts.

CONCLUSIONS

Fourteen percent of the differences in patients' subjectively perceived oral health can be attributed to dentist attitudes and attributes. Further research regarding the influence of dentists personality and professional beliefs on patients well-being needs to be undertaken.

A general dental practice research network--philosophy, activities and participant views

The importance of building research capability among general dental practitioners was highlighted when in 1996 a large tranche of money was released to support research and development in primary dental care. As a result of the links forged by this research opportunity, a group of primary dental care practitioners was recruited into a Primary Dental Network. This network was closely allied to an academic department and the aim was to develop the practitioners' research interest into research skills and finally into a research project. The group therefore attended a series of structured workshops, designed specifically to augment the practitioners' skills using a 'learning by doing' approach. Once the practitioners had acquired the relevant skills, they undertook a research project, which will be reported in a later paper.

Idiopathic familial temporal lobe epilepsy with febrile convulsions

Efforts to duplicate the genetic and molecular breakthroughs of autosomal dominant frontal lobe epilepsy have lead to increased interest in familial temporal lobe epilepsy. In this report we describe three kindreds. The epilepsy syndrome described manifests after the teenage years and was generally mild and treatment responsive. The predominant seizure types were simple and complex partial seizures, typical of mesial temporal onset. Some family members had febrile convulsions only and others had epilepsy without preceding febrile convulsions. Three patients had both febrile convulsions and temporal lobe epilepsy. High-resolution quantitative and qualitative MRI was normal. The syndrome in these three kindreds is distinct from temporal lobe epilepsy due to mesial temporal sclerosis and febrile convulsions and is probably a form of idiopathic localization related epilepsy. Its relation to other familial temporal lobe epilepsy phenotypes is discussed.

Oxidant stress in nephrotic syndrome: comparison of F(2)-isoprostanes and plasma antioxidant potential

BACKGROUND

The nephrotic syndrome (NS) is associated with an increased risk of coronary heart disease. Increased oxidant stress may contribute to this by means of hyperlipidaemia and/or hypoalbuminaemia. In this study we assessed the contributory role of oxidant stress, as measured by F(2)-isoprostanes and plasma oxygen radical absorbance capacity (ORAC), in subjects with NS.

METHODS

We studied 14 subjects with NS and 17 age- and sex-matched healthy non-proteinuric controls. Measurement of plasma and urinary F(2)-isoprostanes was carried out using a combination of silica and reverse-phase cartridges, high-performance liquid chromatography, and gas chromatography mass spectrometry using electron-capture negative ionization. The plasma ORAC assay measured the decrease in fluorescence of phycoerythrin added to plasma in the presence of a free-radical generator. The ORAC value (microM) was calculated as the ratio of the area under the fluorescence decay curve for plasma to the area under the fluorescence decay curve for a Trolox standard.

RESULTS

Plasma ORAC was significantly lower in NS patients compared with controls: mean (standard error) NS patients 3306 microM (286); controls 4882 microM (496), P=0.011. In univariate linear regression analysis, plasma albumin was significantly positively correlated with plasma ORAC (r=0.40, P=0.03). Plasma and urinary F(2)-isoprostanes did not differ significantly between NS and control groups.

CONCLUSIONS

This study demonstrates that in the NS there is decreased free-radical trapping capacity of plasma that is inversely correlated with hypoalbuminaemia, but no increase in plasma and urinary F(2)-isoprostanes. Decreased total plasma antioxidant potential in combination with hyperlipidaemia may contribute to the increased risk of cardiovascular disease seen in NS.

Expression characteristics of the transfer-related kilB gene product of Streptomyces plasmid pIJ101: implications for the plasmid spread function

Intermycelial transfer of Streptomyces plasmid pIJ101 occurs prior to cellular differentiation and is mediated by plasmid functions that are also required for production of zones of growth-inhibited recipient cells (i.e., pocks) that develop around individual donors during mating on agar medium. Several other pIJ101 functions, including that of the kilB gene, whose unregulated expression on pIJ101 is lethal, are required for normal pock size and so have been postulated to mediate intramycelial spread of the plasmid throughout recipient cells. Using antibodies raised against a KilB fusion protein expressed in Escherichia coli, native KilB protein was detected throughout development of pIJ101-containing Streptomyces lividans cells, with the concentration of KilB increasing dramatically and reaching a maximum during the final stages (i.e., sporulation and secondary metabolism) of cellular differentiation. Insertion of the kilB gene of pIJ101 into the S. lividans chromosome in cells lacking the pIJ101 KorB protein, which normally represses kilB gene transcription, resulted in elevated but still temporally increasing amounts of KilB. The increased expression or accumulation of the KilB spread protein throughout cellular differentiation of S. lividans, which leads to maximum KilB concentrations during developmental stages that occur far later than when intermycelial transfer of pIJ101 is mediated, supports the existence of a subsequent intramycelial component to the pIJ101 spread function. The results also suggest that intramycelial spread of pIJ101 molecules within the recipient extends beyond intercompartmental movements within the substrate mycelia and includes undetermined steps within the spore-yielding aerial hyphae as well.

Discriminant validity of the Wender Utah Rating Scale for attention-deficit/hyperactivity disorder in adults

The authors examined the factor structure and discriminant validity of the Wender Utah Rating Scale (WURS) in adults seeking evaluation for attention-deficit/hyperactivity disorder (ADHD). Three factors (Dysthymia, Oppositional/Defiant Behavior, and School Problems) accounted for 59.4% of the variance. In a stepwise discriminant function analysis, age and childhood school problems emerged as significant variables. The classification procedure correctly classified 64.5% of patients. Among those who did not have ADHD, only 57.5% were correctly classified compared with 72.1% among those with ADHD. The WURS is sensitive in detecting ADHD, but it misclassifies approximately half of those who do not have ADHD.

Airway hyperresponsiveness and airway obstruction in transgenic mice. Morphologic correlates in mice overexpressing interleukin (IL)-11 and IL-6 in the lung

Understanding the sources of variation in airway reactivity and airflow is important for unraveling the pathophysiology of asthma, obstructive lung disease, and other pulmonary disorders. Transgenic expression of two closely related cytokines in the mouse lung produced opposite effects on these parameters. Interleukin (IL)-6 did not alter basal airways resistance and decreased methacholine responsiveness, whereas IL-11 caused airways obstruction and increased airway responses to methacholine. To clarify these differences we examined histologic sections and used morphometry to compare bronchiolar and parenchymal dimensions in 1- to 2-mo-old transgenic mice expressing IL-6 or IL-11 and littermate control mice. Both transgenic strains showed similar emphysema-like airspace enlargement, nodular peribronchiolar collections of mononuclear cells, thickening of airway walls, and subepithelial airway fibrosis. When compared with littermate control mice, the IL-6 mice showed an approximately 50% increase in the caliber of their bronchioles and an increase in airway wall thickness that was in proportion to the increase in the size of their airways. In contrast, the remodeling response was more robust in the IL-11 transgenic mice. It was also seen in airways with normal external and luminal diameters and thus was out of proportion to the caliber of their airways. These results support the hypothesis that structural alterations and resulting caliber changes of respiratory airways can have important effects on airway physiology and reactivity.

Impact of prenatal care with reduced frequency of visits in a residency teaching program

OBJECTIVE

To determine if decreasing the number of prenatal visits for routine obstetric patients affects pregnancy outcome.

STUDY DESIGN

A historical control study was designed to include 734 deliveries from January 1 to December 31, 1991, in women who had prenatal care per American College of Obstetricians and Gynecologists Committee Opinion no. 79, January 1990, guidelines for uncomplicated obstetric care. A prospective study cohort of women with 711 deliveries from January 1 to December 31, 1994, underwent prenatal care with modified guidelines to include: first visit at 6-12 weeks to confirm dating and obtain initial laboratory data, second visit at 16-20 weeks to obtain maternal serum alpha-fetoprotein screening, third visit at 24-28 weeks for 28-week laboratory data, fourth visit at 32 weeks, fifth visit at 36 weeks, sixth visit at 38 weeks, seventh visit at 40 weeks and weekly thereafter. Pregnancy outcomes included estimated fetal weight, gestational age at delivery, preeclampsia, Apgar score at one and five minutes and delivery mode. Neonatal outcomes, including stillbirth rate, preterm delivery rate, intraventricular hemorrhage rate, bronchopulmonary dysplasia and neonatal mortality, were evaluated.

RESULTS

There were no statistically significant differences in perinatal or neonatal outcomes with decreased prenatal visits from an average of 12 per pregnancy to 8.

CONCLUSION

Prenatal visits can be decreased in a teaching hospital in women with uncomplicated pregnancies from the standard number, 12-14 visits, to an average of 7 or 8 per patient without adverse perinatal outcomes.

An open-label, multicentre, randomised phase 2 study of recombinant human granulocyte colony-stimulating factor (filgrastim) as an adjunct to combination chemotherapy in paediatric patients with metastatic neuroblastoma

Administration of combination chemotherapy to children with metastatic neuroblastoma induces profound myelosuppression resulting in chemotherapy treatment delays and febrile neutropenic episodes. The objective of this randomised multicentre study was to assess the incidence, duration and severity of neutropenia when filgrastim is added to induction chemotherapy administered to patients with metastatic neuroblastoma. In this study, 59 patients with metastatic neuroblastoma were randomised to receive chemotherapy (control group, n = 28) or chemotherapy plus filgrastim (filgrastim group, n = 31). Chemotherapy consisted of four cycles of cyclophosphamide, vincristine and doxorubicin (CADO) alternating at 21-day intervals with cisplatin and etoposide (CDDP-VP16). Filgrastim was administered subcutaneously at a dose of 5 micrograms/kg/day from day 7 for up to 14 days. The incidence of neutropenia (absolute neutrophil count [ANC] < 0.5 x 10(9)/l) in the filgrastim group was not reduced after the first CADO course. However, significant reductions were observed after courses 2, 3 and 4. The duration of neutropenia and of intravenous antibiotic use were significantly reduced in the filgrastim group over the whole study period (9 days versus 26 days, P < 0.001; 12 days versus 20 days, P = 0.04, respectively). However, the duration of hospitalisation and the incidence of febrile neutropenia were not significantly reduced. Compliance to treatment was good and the ability to administer chemotherapy without treatment delays was significantly better in the filgrastim group (P < 0.05). Event-free survival was greater in the filgrastim than in the control group (2.4 years versus 1.3 years; P = 0.072). Filgrastim is a beneficial adjunct to combination induction chemotherapy used in the treatment of metastatic neuroblastoma.

The LEC rat possesses reduced hepatic selenium, contributing to the severity of spontaneous hepatitis and sensitivity to carcinogenesis

The hepatic concentrations of copper, zinc, magnesium, calcium, and selenium were measured in LEC rats, which develop a spontaneous form of hepatitis at 3-4 months of age, and compared to trace metal concentrations in the LEA rat, its asymptomatic congenic strain. Consistent with results found by other groups, copper was found to accumulate within the liver of LEC rats to levels more than 50 times those measured in LEA rats. In addition, liver selenium concentration in LEC rats was found to be around 50% of that in LEA rats. The enzyme activity, and RNA for the selenium dependent enzyme, glutathione peroxidase, was also found to be reduced in LEC rat liver. These results indicate that hepatic selenium in the LEC rat is depleted and that, as a result of this, the capacity to protect cells from copper-induced free-radical damage is reduced.

Neuropsychological outcome of experimental manipulation of phenylalanine intake in treated phenylketonuria

Blood phenylalanine concentrations were experimentally increased for 3 months by means of a phenylalanine-complemented amino acid supplement in a group of 16 children aged 10-16 years with classical phenylketonuria who had been treated early and who had remained on the restricted diet. Average concentrations achieved during challenge were between 1000 and 1300 mumol/L. Psychological outcome was measured by a neuropsychological battery consisting of tests of verbal and spatial memory, attention and fine motor coordination. A triple-blind, repeated measures, randomized, crossover design was adopted to control for practice and expectancy effects. Subjects were assessed at baseline and at the end of the first and second phenylalanine manipulation periods. Significant interactions (ANOVA) emerged as predicted for phenylalanine concentrations, but similar crossover effects were not found for any of the neuropsychological tests. The results suggested that medium-term hyperphenylalaninaemia in treated PKU is not harmful to psychological functioning in older children and adolescents who have been continuously treated up to and beyond age 10 years, though the susceptibility of executive functions needs to be further researched. The findings add some weight to the idea that by late childhood the vulnerability of the nervous system to the neurotoxic influence of phenylalanine may be much reduced.

Adult attention-deficit hyperactivity disorder: assessment guidelines based on clinical presentation to a specialty clinic

Of 143 adults presenting for attention-deficit hyperactivity disorder (ADHD) evaluation, 46 (32%) clearly met diagnostic criteria, 46 (32%) clearly did not meet diagnostic criteria, and another 51 (36%) with current ADHD-like features did not meet criteria due to either a lack of childhood history and/or complicating severe psychiatric or substance abuse comorbidity. The three groups were similar in demographics, psychiatric diagnosis, psychiatric symptom severity, and functional impairment. Compared with the group not meeting ADHD criteria, patients with ADHD had more frequent histories of learning disability in childhood, poorer reading scores on the Wide-Range Achievement Test (WRAT), poorer scores on the Continuous Performance Test (CPT), and higher scores on the Wender-Utah Rating Scale (WURS) for ADHD. Patients in the ambiguous ADHD category had higher rates of current substance abuse than the other two groups. While this group resembled the non-ADHD group in having a low incidence of learning disability and normal reading scores, their poor performance on the CPT and high scores on the WURS more closely resembled those of ADHD patients. These findings suggest that there are a few rating scales, testing instruments, and lifetime history characteristics that help to clarify the difficult diagnostic distinction between adult patients who do and do not have ADHD.

Filgrastim to treat neutropenia and support myelosuppressive medication dosing in HIV infection. G-CSF 92105 Study Group

BACKGROUND

Patients with HIV infection frequently experience disease or treatment-related myelosuppression leading to neutropenia. Neutropenia often leads to dose-reduction or discontinuation of important myelosuppressive therapy.

OBJECTIVE

To examine the efficacy and safety of filgrastim for reversing neutropenia and determine the effect of this on use of myelosuppressive medications.

DESIGN

Open-label, non-comparative, multicentre study in 200 HIV-positive patients with neutropenia [absolute neutrophil count (ANC) < 1.0 x 10(9)/l]. Filgrastim was started at 1 microgram/kg/day subcutaneously for 28 days. This initial treatment phase was followed by a maintenance phase, using 300 micrograms on 1-7 days/week. In both phases the dose of filgrastim was adjusted to achieve an ANC of 2-5 x 10(9)/l.

RESULTS

Filgrastim reversed neutropenia in 98% of patients (ANC > or = 2 x 10(9)/l), with a median time to reversal of 2 days (range 1-16) and a median dose of 1 microgram/kg/day (range 0.5-10). Most patients (96%) achieved reversal of neutropenia with a filgrastim dose of < or = 300 micrograms/day (< or = 1 vial/day). Normal ANCs were then maintained with a median of 1 microgram/kg/day (range 0.22-10.6) during the treatment phase and 3 x 300 micrograms vials/week (range 1-7) during the maintenance phase. Ganciclovir, zidovudine, co-trimoxazole and pyrimethamine were the drugs most frequently considered to be causing neutropenia, and 83% of patients received one or more of these in the study. Filgrastim allowed > 80% of patients to increase or maintain dose-levels of these four medications or add them to their therapy. The number of these four medications received per patient increased by > 20% during filgrastim therapy. Filgrastim was well tolerated. CD4, CD8 and total lymphocyte counts all increased slightly, and there was no difference in HIV-1 p24 antigen levels.

CONCLUSION

Filgrastim rapidly reverses neutropenia and maintains normal ANC in patients with HIV infection. This allows greater use of myelosuppressive medications without the potentially life-threatening complications of neutropenia.

In vitro hydrogen production by glucose dehydrogenase and hydrogenase

A new in vitro enzymatic pathway for the generation of molecular hydrogen from glucose has been demonstrated. The reaction is based on the oxidation of glucose by Thermoplasma acidophilum glucose dehydrogenase with the concomitant oxidation of NADPH by Pyrococcus furiosus hydrogenase. Stoichiometric yields of hydrogen were produced from glucose with the continuous recycling of cofactor. This simple system may provide a method for the biological production of hydrogen from renewable sources. In addition, the other product of this reaction, gluconic acid, is a high-value chemical commodity.

Unraveling the extent of diversity within the order Planctomycetales

The phylogenetic positions of 22 isolates that morphologically resemble members of the family Planctomycetaceae were determined by sequence analysis of genes coding for 16S rRNA. While nine and eight isolates could be assigned to the genera Planctomyces and Pirellula, respectively, three strains grouped near Isosphaera pallida and one strain was closely related to Gemmata obscuriglobus. No isolate was found to be related to a previously described species of any of the four genera at the species level. Morphological characters and sequence idiosyncrasies of genes coding for 16S rRNA of the isolates generally correlated with features described for the four genera to which the isolates could be assigned. One strain stands phylogenetically isolated and may be representative of a novel genus of the family. Comparison with environmental clone sequences representing planctomycetes in soil and water revealed that three of the novel isolates were related to one clone of soil origin, but no close relationships between clones and the other new strains were found. The study reveals that the biodiversity of planctomycetes is significantly greater than was previously determined.

Serum insulin is a risk marker for coronary heart disease mortality in men but not in women

Serum insulin 1 h post-glucose load is examined in this prospective study of 2971 Caucasoid subjects aged > 20 years in 1966 and followed to 1989. The serum insulin levels as a continuous variable show no significant linear association with coronary heart disease (CHD) deaths in either sex after accounting for age by Cox proportional hazards analysis. In males the quintile classes of serum insulin show a striking U-shaped pattern with both the highest and lowest quintiles having significant associations with CHD deaths. In females the insulin quintiles show no direct association. Analysis for interactions of risk variables indicate that in females the relative protection of low cholesterol levels is abolished by hyperinsulinaemia after 12 years. Thus, serum insulin is not a direct aetiological risk factor for CHD. The findings suggest that the associations are likely to be due to confounding effects of unmeasured variables including lipid subfractions.

Chemosensitization of murine fibrosarcoma cells to drugs affected by the multidrug resistance phenotype by the antidepressant trazodone - an experimental-model for the reversal of intrinsic drug-resistance

A variety of resistance phenotypes to cytotoxic agents in bacteria, protozoa parasites and mammalian cells are mediated by evolutionarily conserved proteins of the mdr family. The finding that chloroquine resistance in the malarial parasite, Plasmodium falciparum, that is mediated by an mdr-1 gene product can be circumvented by tricyclic antidepressant drugs has stimulated the present study to assess whether this class of agents might also modulate the multidrug resistance (MDR) phenotype(s) in mammalian tumor cells. The possible chemosensitizing effects of nine antidepressant drugs have been tested against the UV-2237M murine fibrosarcoma line and its MDR variant. At nontoxic concentrations all nine antidepressants markedly enhanced the cytotoxicity of ADR against the parental cells but were much less effective against the MDR cells. The most active antidepressant, trazodone, also enhanced the cytotoxicities of vinblastine and vincristine, but not those of actinomycin D, mitomycin C, or 5-fluorouracil. The parental cells treated with trazodone exhibited an increased accumulation of intracellular ADR, but lacked detectable alterations in the expression and drug-binding activity of plasma membrane P-glycoprotein, and trazodone did not affect the activities of isolated protein kinase C and calmodulin. These data suggest that the antidepressant drug trazodone may be useful in the reversal of the intrinsic drug resistance of tumor cells that express low levels of P-glycoprotein.

Excitotoxic lesions of the pedunculopontine tegmental nucleus of the rat. II. Examination of eating and drinking, rotation, and reaching and grasping following unilateral ibotenate or quinolinate lesions

The pedunculopontine tegmental nucleus (PPTg) contains a population of cholinergic neurons thought to be part of the ascending reticular activating system, and non-cholinergic neurons. In the previous study it was shown that various excitotoxins made effective lesions of cholinergic neurons in the PPTg but that quinolinate made smaller lesions in the non-cholinergic population, making it more selective than any other excitotoxin. The purpose of the present experiment was, first, to make lesions of cholinergic neurons throughout the length of the PPTg by infusing toxin at two different sites within it; and second, to examine simple motor activities in rats bearing either quinolinate or ibotenate lesions of the PPTg, and contrast these with the deficits seen after 6-hydroxydopamine (6-OHDA) induced lesions of mesostriatal dopamine (DA)-containing neurons. Post-mortem examination was carried out using choline acetyltransferase (ChAT) and tyrosine hydroxylase (TOH) immunohistochemistry, and routine Nissl staining. Both quinolinate and ibotenate destroyed approximately 75% of ChAT-positive neurons in the PPTg, but damage to non-cholinergic neurons (assessed by Nissl staining) was twice as great following ibotenate as quinolinate. 6-OHDA induced almost complete lesions of mesostriatal DA neurons, assessed by TOH immunohistochemistry. DA depleted rats showed deficits in drinking and spilled more food in the first 2 weeks after surgery, and were unable to reach or grasp food pellets in the staircase test. They also showed strong ipsilateral turning in response to amphetamine and contralateral turning to apomorphine. Quinolinate lesioned rats had no eating or drinking impairment in the home cage but showed a reaching (though not grasping) disability in the staircase test. They had a mild ipsilateral bias following amphetamine. Ibotenate lesioned rats, despite having larger lesions than the quinolinate, showed no deficits in eating or drinking in the home cage, or reaching or grasping disabilities in the staircase test. They did have a mild contralateral bias in response to amphetamine. This dissociation of the effects of quinolinate and ibotenate lesions of the PPTg is consistent with the suggestion that the PPTg has two functionally distinct components, and is attributed to the differential lesion of non-cholinergic neurons by the two excitotoxins.

Rapid measurement of basic drugs in blood applied to clinical and forensic toxicology

A gas chromatographic method is presented to measure blood, serum or plasma concentrations of more than 40 basic drugs. The sensitivity is 0.05 mg/L or less, which represents medium-high therapeutic and overdose concentrations, and in many instances the major active metabolites are also quantified. The paper describes a single step extraction from basic solution into n-butyl acetate containing maprotiline internal standard. Disposable glass tubes are used, with direct chromatography of the upper organic layer. GLC analysis is conducted for 10 min isothermally on a packed column (3% SP2250) with nitrogen-phosphorus detection. The coefficient of variation (CV) of the assay is between 2% and 5%, and data on the reproducibility of retention times are presented.

Gas chromatographic measurement of cocaine in serum, plasma and whole blood

A gas chromatographic method is presented to measure cocaine in serum, plasma or blood. To reduce the in-vitro chemical and enzymic hydrolysis of cocaine, samples should be collected into fluoride oxalate tubes, frozen immediately and stored at -20 degrees C until analysis. Extractions are carried out in disposable glass tubes immersed in an ice-bath. The method uses a single step extraction from a mildly basic solution into n-butyl acetate containing maprotiline internal standard. A portion of the upper organic layer is chromatographed for 5 min isothermally on a packed column (3% SP2250) with nitrogen-phosphorus detection. The coefficient of variation (CV) of the assay is below 6% at 0.1 mg/L and the limit of accurate measurement is 0.02 mg/L. A case of acute cocaine intoxication is described to illustrate the application of the method.

Tissue aluminum concentrations stability over time, relationship to age, and dietary intake

Aluminum concentration was measured in serum, whole blood, hair, and urine by neutron activation analysis. Seventy-six nondemented subjects were investigated. Not all assays were done on all subjects (e.g., serum aluminum on 76 subjects, whole blood aluminum on 42 subjects), but tissue aluminum concentrations were estimated on more than one occasion on 32 subjects. The mean +/- SD aluminum concentration in serum was 0.219 +/- 0.063 micrograms/ml (N = 76), in whole blood 0.368 +/- 0.091 micrograms/ml (N = 42), in urine 0.092 +/- 0.076 micrograms/ml (N = 42), and in hair 6.42 +/- 2.22 micrograms/g (N = 42). Using product moment correlation coefficient there was no significant correlation between age and tissue aluminum concentrations, nor between dietary intake of aluminum and tissue aluminum. The tissue aluminum concentrations were not stable over time even when dietary intake was constant. Tissue aluminum concentrations were measured in 14 patients after 7 days of dietary control and repeated approximately 6 weeks later, again after 7 days of dietary control. There was no significant correlation between the two estimations in any tissue measured. These results suggest that raised tissue aluminum concentrations reported in Alzheimer's disease are not an exaggeration of a normal ageing process, are not likely to be simply secondary to increased dietary aluminum intake, and that Alzheimer's disease does not represent the chronic toxic effect of moderately raised aluminum levels at the upper end of the normal distribution.

Caesium levels in manic depressive psychosis

Concentrations of caesium were estimated in hair, whole blood, serum and urine by neutron activation analysis, in samples from manic patients, depressed patients, recovered manic patients, recovered depressed patients and normal controls. There was no difference in the concentration of caesium measured between the various diagnostic categories. These results contradict the findings of previous reports.

A study of physician preferences in the management of depression in the general medical setting

Although more than 30% of ambulatory medical patients are depressed, little is known about how their depression is managed in the primary care setting. We surveyed 282 primary care physicians at two internal medicine and four family medicine programs. We asked these physicians to describe how they actually managed depression in their depressed medical patients and how they would manage ten hypothetical depressed medical patients. Demographic and attitudinal data were also obtained. Physicians reported that they utilized a wide variety of treatments for their depressed patients. They indicated that they would recommend counseling twice as many depressed patients as they would recommend medicating or referring. Over 30% of the variance in self-reported preferences to recommend particular treatments for depression was accounted for by physician characteristics. Prior experience with a treatment strategy was a significant factor in predicting a recommendation for future use of a treatment independent of other considerations such as endorsement of positive attitudes about the efficacy or benefits of a treatment. Prior experience was also more important than physician sociodemographics as a predictive variable. The clinical and educational implications of these findings for psychiatrists and primary care physicians are discussed.

Career orientations of medical and pediatric residents

Educators have expressed concern about the declining percentage of graduating residents who choose an academic career. This study identifies characteristics of postgraduate physicians that are associated with intentions to pursue an academic career or a full-time private practice. Data were obtained from 299 residents in pediatrics and internal medicine at five academic medical centers in Southern California, using self-report questionnaires. Preference for an academic career was strongest among residents who were most satisfied with their work, were frequently sponsored by faculty, had published, or who either lived alone or were married to another professional. The likelihood of full-time private practice was strongest among residents who were less frequently sponsored by faculty, had not published, lived with others, were from certain medical schools, or were females. Training programs may wish to consider some of these factors in the selection of residents and in program development.

Antidepressants in concomitant chronic back pain and depression: doxepin and desipramine compared

Doxepin and desipramine at final doses of 188 and 173 mg/day, respectively, were compared in 36 volunteers with major affective or dysthymic disorder and chronic back pain. Both drugs produced significant decreases in depression, with an overall response rate of 70%; no significant difference was seen between groups. Pain ratings also decreased significantly in both groups (overall response rate = 50%); pain severity showed a better response to doxepin than to desipramine. While baseline pain, depression, and anxiety were correlated, treatment changes in these measures did not correlate. CSF beta-endorphin levels did not change with treatment. The usefulness of an antidepressant with anxiolytic properties, such as doxepin, is discussed.

Thiothixene plasma levels and clinical response in acute schizophrenia

Plasma levels of cis and trans thiothixene were compared to clinical response in 8 acutely schizophrenic inpatients. While absolute plasma levels did not appear to correlate with clinical condition, the data did suggest that increases or decreases in cis plasma levels correlated with corresponding improvements or deteriorations in clinical condition in thiothixene responsive patients. While the results are very preliminary, the authors suggest that future studies differentiate the cis and trans isomers, and analyze relative as well as absolute changes in plasma levels as compared to clinical changes.

Effects of alcohol on biliary lipids in the presence of a chronic biliary fistula

To investigate the effects of alcohol on bile volume and bile composition, dogs with a Thomas cannula and cannulated common ducts were given loading and maintenance doses of alcohol. Bile was analyzed for total bile salts, phospholipids and cholesterol. In dogs with partial interruption of the enterohepatic circulation, alcohol caused significant diminution of volume and outputs of bile salts and cholesterol. However, when a high bile flow was maintained by intravenous infusion of taurocholate sodium, the effects of alcohol on volume and total bile salts were no longer demonstrated. Fall in cholesterol output, nevertheless, persisted. These results show that alcohol causes significant changes in bile flow and biliary lipid composition and support the existence of a bile salt independent fraction of cholesterol secretion in the dog.