Hybrid Oleate-Iodide Ligand Shell for Air-Stable PbSe Nanocrystals and Superstructures

A postsynthetic treatment is presented to improve the air stability of PbSe nanocrystals (NCs) and PbSe square superstructures. The addition of z-type Pb(oleate)₂ ligands together with x-type iodide ligands creates a hybrid ligand shell containing both ligands. The air stability of the PbSe NCs is checked by enduring absorption spectroscopy under ambient conditions. With a combined NaI + Pb(oleate)₂ treatment, the absorption spectrum remains unchanged for several days under ambient conditions. Fourier transform infrared spectroscopy shows that the surface coordination of the oleate ligands changes by the chemical treatment: from mixed chelating bidentate + bridging to Pb for the pristine nanocrystals to almost exclusive chelating bidentate coordination after chemical passivation. The shift of the C-H stretching vibration shows that the oleate hydrocarbon layer is in a more liquidlike state after the chemical treatment, suggesting that oleate and iodide ligands are often present on adjacent surface positions.

Holarctic phylogeographic structure of Eurasian wigeon (Mareca penelope)

The Eurasian wigeon (Mareca penelope) is one of the most numerous migrant species of waterfowl in the Palearctic. Annually, significant part of the world’s wigeon population makes seasonal flights over distances from tens to thousands or more kilometers. According to different estimates based on banding data, five geographic populations of the species were described in the Palearctic. However, distinct borders between the populations have not been identified. At the same time, no phylogeographic studies have been carried out for the complete native range of wigeon so far. In addition to the fundamental importance of such a study, knowledge of the genetic structure of populations is necessary for the development of measures to increase the number of and preserve this valuable game species. The aim of our work was a phylogeographic analysis of the wigeon across its vast native range in the Palearctic including ducks wintering in North America. We examined genetic diversity and differentiation of wigeon populations identified with banding data, phylogenetic relationships of mtDNA haplotypes and demographic history of populations and species as a whole by sequencing a 661 base-pair 5’-fragment of the mitochondrial control region from 195 individual ducks collected throughout the Palearctic and Nearctic. Genetic diversity was high in all studied populations. A reconstruction of haplotypes phylogeny revealed the absence of geographic structure in the data. Nonetheless, analysis of molecular variance (AMOVA) identified two groups of populations: EuropeanSiberian and East Asian. The former included wigeons from Europe, Siberia and the Atlantic coast of North America, and the latter comprised ducks from Russian Far East, Kamchatka Peninsula, Chukotka Autonomous District, the Aleutian Islands, Alaska, and the Pacific coast of North America.

Use of test accuracy study design labels in NICE's diagnostic guidance

BACKGROUND

A variety of study designs are available to evaluate the accuracy of tests, but the terms used to describe these designs seem to lack clarity and standardization. We investigated if this was the case in the diagnostic guidance of the National Institute of Care and Health Excellence (NICE), an influential source of advice on the value of tests.

OBJECTIVES

To describe the range of study design terms and labels used to distinguish study designs in NICE Diagnostic Guidance and the underlying evidence reports.

METHODS

We carefully examined all NICE Diagnostic Guidance that has been developed from inception in 2011 until 2018 and the corresponding diagnostic assessment reports that summarized the evidence, focusing on guidance where tests were considered for diagnosis. We abstracted labels used to describe study designs and investigated what labels were used when studies were weighted differently because of their design (in terms of validity of evidence), in relevant sections. We made a descriptive analysis to assess the range of labels and also categorized labels by design features.

RESULTS

From a total of 36 pieces of guidance, 20 (56%) were eligible and 17 (47%) were included in our analysis. We identified 53 unique design labels, of which 19 (36%) were specific to diagnostic test accuracy designs. These referred to a total of 12 study design features. Labels were used in assigning different weights to studies in seven of the reports (41%) but never in the guidance documents.

CONCLUSION

Our study confirms a lack of clarity and standardization of test accuracy study design terms. There seems to be scope to reduce and harmonize the number of terms and still capture the design features that were deemed influential by those compiling the evidence reports. This should help decision makers in quickly identifying subgroups of included studies that should be weighted differently because their designs are more susceptible to bias.

Hemodynamic Effects of Gadodiamide Injection and Gadopentetate Dimeglumine in Anesthetized Dogs

A nonionic (gadodiamide injection) and an ionic (gadopentetate dimeglumine) contrast medium were compared for their effect on hemodynamics in the anesthetized, open-chest dog. Both agents were administered i.v. over 15 s at dosages of 1.0 and 1.5 mmol/kg, in randomized order. Both contrast agents resulted in transient but statistically significant decreases in aortic pressure, left ventricular pressure, indices of left ventricular contractility and relaxation, and systemic and pulmonary vascular resistance, and increases in aortic blood flow. At each dosage investigated, the changes associated with the administration of gadodiamide injection were of significantly smaller magnitude than those seen after gadopentetate dimeglumine and returned to preadministration levels sooner. The results from this study confirm that gadodiamide injection produces less severe alterations in hemodynamics than gadopentetate dimeglumine.

Prenatal negative life events increases cord blood IgE: interactions with dust mite allergen and maternal atopy

BACKGROUND

Prenatal exposure to both stress and aeroallergens (dust mite) may modulate the fetal immune system. These exposures may interact to affect the newborn immune response. We examined associations between prenatal maternal stress and cord blood total IgE in 403 predominately low-income minority infants enrolled in the Asthma Coalition on Community, Environment, and Social Stress (ACCESS) project. We also examined potential modifying effects of maternal atopy and maternal dust mite exposure.

METHODS

The Crisis in Family Systems survey was administered to mothers prenatally, and a negative life event domain score was derived to characterize stress. Dust mite allergen was quantified in dust from pregnant mothers' bedrooms. Cord blood was analyzed for total IgE. Using linear regression, we modeled the relationship of stress with cord blood IgE and interactions of stress with dust mite and/or maternal atopy, adjusting for potential confounders.

RESULTS

Higher prenatal maternal stress (β = 0.09; P = 0.01) was associated with increased cord blood IgE. The interactive effects between stress and dust mite groups (high vs low) were significantly different for children of atopic vs nonatopic mothers (P for three-way interaction = 0.005). Among children of atopic mothers, the positive association between stress and IgE was stronger in the high dust mite group. In children of mothers without a history of atopy, the positive association between stress and IgE was most evident in the low allergen group.

CONCLUSIONS

Prenatal stress was independently associated with elevated cord blood IgE. Mechanisms underlying stress effects on fetal immunomodulation may differ based on maternal atopic status.

Ambiguous genitalia in a fertile, unilaterally cryptorchid male miniature schnauzer dog

A 7-year-old male miniature schnauzer dog with unilateral cryptorchidism was presented for elective orchiectomy. Surgery to remove the cryptorchid testis revealed a fully formed uterus with horns attached to both testis and the body and cervix terminating at the prostate gland. The gross and microscopic diagnosis for the genital tract was persistent Müllerian duct syndrome with unilateral cryptorchidism. Additional associated lesions included cystic endometrial hyperplasia and a solitary, intratubular seminoma within the undescended testis. Persistent Müllerian duct syndrome is rare among domestic animals but is more common in miniature schnauzer dogs because of inheritance as an autosomal recessive trait.

[Interest of BNP value after cardiac resynchronisation therapy]

Cardiac resynchronisation therapy (CRT) induces, among responders, an early but sustained decrease of BNP levels. The changes of this parameter at 6 months, as well as its relative variations over the same time period, allow identification of the patients susceptible to benefit from CRT. Measurements of BNP levels might offer a useful tool for treatment optimisation in this particularly frail group of patients.

The prevalence of co-morbid depression in adults with Type 2 diabetes: a systematic review and meta-analysis

AIM

To conduct a systematic literature review in order to estimate the prevalence and odds ratio of clinically relevant depression in adults with Type 2 diabetes compared with those without.

METHODS

MEDLINE, EMBASE and PSYCINFO databases were searched using MeSH terms and free text to identify relevant controlled studies. Published reference lists were also examined. Study selection and appraisal were conducted independently by two reviewers and a meta-analysis was performed to synthesize and analyse the data.

RESULTS

Ten controlled studies including a total of 51 331 people were published between January 1980 and May 2005. The prevalence of depression was significantly higher in patients with Type 2 diabetes compared with those without [17.6 vs. 9.8%, OR = 1.6, 95%, confidence interval (CI) 1.2-2.0]. However, in most studies, patients with diabetes differed from those without on variables known to be associated with an increased risk of depression. The prevalence of depression was higher in females with diabetes (23.8%) compared with males (12.8%); however, the odds ratio for depression in patients with Type 2 diabetes compared with those without was higher in males (OR = 1.9, 95% CI 1.7-2.1) than females (OR = 1.3, 95% CI 1.2-1.4). Failure to report potential confounders prevented a more rigorous meta-analysis of risk.

CONCLUSION

We identified raised rates of depression in people with Type 2 diabetes, however, there is a need for well-controlled and better-reported studies to inform the development of effective treatments for depression in these patients.

The outcome of renal denervation for managing loin pain haematuria syndrome

OBJECTIVE

To evaluate the outcome of renal denervation for the treatment of loin pain-haematuria syndrome (LPHS), a rare syndrome of unknown cause associated with debilitating and intractable loin pain.

PATIENTS AND METHODS

The case notes of 32 patients having 41 renal denervations were reviewed. Data collected included patient demographics, possible causes, cure or not after renal denervation, time to recurrence of pain after denervation and further operative intervention for managing LPHS.

RESULTS

Full data were available for 24 patients (13 women; median age 43 years, range 28-74) having 33 denervations (eight bilateral and one repeat) with a median follow-up of 39.5 months. Most patients had no identifiable underlying cause although many had initially been diagnosed as having stone disease (42%) or pyelonephritis (25%), but with no corroborative evidence. All patients had been extensively investigated and had normal urine samples and cytology, and no abnormality on intravenous urography, renal tract ultrasonography and isotopic renography. Twenty-four renal denervations (73%) were followed by recurrent ipsilateral pain at a median (range) of 11 (0-120) months after surgery. Nine denervations (25%) in six men and two women were curative (median follow-up 16.5 months). Of those with recurrent pain, nine (38%) proceeded to nephrectomy, of whom three then developed loin pain on the contralateral side and two developed disabling wound pain. The analgesic requirement was less after eight non-curative denervations. There were no significant postoperative complications.

CONCLUSIONS

Renal denervation has only a 25% success rate for managing pain associated with LPHS and should be used cautiously for this indication. Men had more benefit from the treatment; a third of patients had less requirement for analgesic after non-curative denervation.

An AFLP-based genome-wide mapping strategy

To efficiently determine the chromosomal location of phenotypic mutants, we designed a genome-wide mapping strategy that can be used in any crop for which a dense AFLP (Amplified Fragment Length Polymorphism) map is available or can be made. The AFLP technique is particularly suitable to initiate map-based cloning projects because it detects many markers per reaction. First a standard set of AFLP primer combinations that results in a framework of AFLP markers well dispersed over the genome is selected. These primer combinations are applied to a limited number of mutant individuals from a segregating population to register linkage and non-linkage of the AFLP markers to the gene-of-interest. Further delineation of the area of interest is accomplished by analyzing the remaining recombinants and additional mutant individuals with AFLP markers that lie within the identified region. We illustrate the usefulness of the method by mapping three rotunda ( ron) leaf-form mutant loci of Arabidopsis thaliana and show that in the initial phase of map-based cloning projects a 400-600 kb interval can be identified for the average mutant locus within a few weeks. Once such an area is identified and before initiating the more time-consuming fine-mapping procedure, it is essential to examine publicly available databases for candidate genes and known mutants in the identified region. The 390-kb interval on chromosome 4 that harbors the ron2 mutation, also carries a known flower mutant, leunig ( lug); upon crossing, the two mutants appeared to be allelic. When no such candidates are found, the mapping procedure should be continued. We present a strategy to efficiently select recombinants that can be used for fine mapping.

Management of colonic injury following percutaneous nephrolithotomy

Injury to the colon during percutaneous nephrolithotomy is rare. There are no definitive management guidelines for this injury. We report a case of left-sided colonic injury diagnosed following percutaneous nephrolithotomy and suggest a treatment algorithm.

Bone loss associated with the use of LHRH agonists in prostate cancer

Hypogonadism is a recognised cause of osteoporosis in men. When patients with advanced prostate cancer are treated with luteinising hormone releasing hormone (LHRH) agonist analogues their circulating testosterone levels decline and these patients may develop fractures.We have undertaken a cross-sectional study on a cohort of patients treated with goserelin (n=41) and compared their bone density and bone turnover with patients with prostate cancer not on goserelin and elderly patients living in the community.There was no difference in bone density between the patients on treatment and those living in the community and there was a similar incidence of osteoporosis (50 and 42%, respectively). The bone marker measurements were higher in the treated patients: urine N-telopeptide (NTX) 80.1 (9) (mean (s.e.)) BCE/mmol, compared to 30.1 (2.9), P<0.001 in elderly patients; and bone alkaline phosphatase 41.9 (6.1) u/l in treated patients and 20.7 (1.5) in untreated prostate cancer patients, P<0.002. Patients on treatment with radionuclide scan evidence of metastases did not have higher bone marker values than those with negative scans.As increased bone turnover and low bone density are associated with enhanced risk of osteoporotic fractures, we suggest that patients on LHRH agonist analogues should receive advice and possibly anti-bone resorptive treatment with bisphosphonates to prevent further bone loss and fractures.Prostate Cancer and Prostatic Diseases (2001) 4, 161-166.

Intratesticular lipoma

Benign intratesticular lesions are rare. We describe the second reported case of an intratesticular lipoma and discuss the limitations of ultrasonography in differentiating benign from malignant conditions occurring within the testis.

A physical amplified fragment-length polymorphism map of Arabidopsis

We have positioned amplified fragment-length polymorphism (AFLP) markers directly on the genome sequence of a complex organism, Arabidopsis, by combining gel-based AFLP analysis with in silico restriction fragment analysis using the published genome sequence. For placement of the markers, we used information on restriction fragment size, four selective nucleotides, and the rough genetic position of the markers as deduced from the analysis of a limited number of Columbia (Col)/Landsberg (Ler) recombinant inbred lines. This approach allows for exact physical positioning of markers as opposed to the statistical localization resulting from traditional genetic mapping procedures. In addition, it is fast because no extensive segregation analysis is needed. In principle, the method can be applied to all organisms for which a complete or nearly complete genome sequence is available. We have located 1,267 AFLP Col/Ler markers resulting from 256 SacI+2, MseI+2 primer combinations to a physical position on the Arabidopsis genome. The positioning was verified by sequence analysis of 70 markers and by segregation analysis of two leaf-form mutants. Approximately 50% of the mapped Col/Ler AFLP markers can be used for segregation analysis in Col/C24, Col/Wassilewskija, or Col/Cape Verde Islands crosses. We present data on one such cross: the localization of a viviparous-like mutant segregating in a Col/C24 cross.

LH secretion and testosterone concentrations are blunted after resistance exercise in men

This study examined the hypothesis that exercise-induced changes in circulating testosterone would be centrally mediated via hypothalamic-pituitary release of luteinizing hormone (LH). We tested this hypothesis by examining overnight LH, total and free testosterone (TT and FT), and cortisol (C) concentrations in 10 young healthy men (21 +/- 1 yr) during two experimental sessions: a control and an acute heavy-resistance exercise bout (50 total sets consisting of squats, bench press, leg press, and latissimus dorsi pull-down). Exercise was performed from 1500 to 1700, and blood sampling began at 1700 and continued until 0600 the next morning. Blood was sampled every 10 min for LH and every hour for TT, FT, and C. Hormonal concentrations were determined via RIA, and the secretion characteristics of LH were analyzed with deconvolution analysis. When overnight postexercise concentrations were compared with control concentrations, no statistically significant (P < or = 0.05) differences were observed for LH half-life, LH pulse frequency, interpulse interval, pulse amplitude, or pulse mass. Significant differences were observed for LH production rate (13.6 +/- 4 and 17.9 +/- 5 IU. l distribution volume(-1) x day(-1) for exercise and control, respectively, a 24% reduction). For the ANOVA marginal main effect means due to condition, C was significantly elevated (5.9 +/- 0.7 vs. 4.0 +/- 0.4 microg/dl), while TT (464 +/- 23 vs. 529 +/- 32 ng/dl) and FT (15.6 +/- 0.7 vs. 18.3 +/- 0.9 pg/ml) were significantly decreased for the exercise condition. These data demonstrate that the decline in overnight testosterone concentrations after acute heavy-resistance exercise is accompanied by a blunted LH production rate and elevated C concentrations.

Increased patient satisfaction from transrectal ultrasonography and biopsy under sedation

OBJECTIVE

To determine the acceptability and patient satisfaction of transrectal biopsy undertaken with the patient under sedation. Patients and methods A retrospective questionnaire was sent to 100 patients who had undergone transrectal biopsy between January and August 1998. Levels of patient acceptability and satisfaction were assessed using visual analogue scales (VAS, with a maximum score of 10 being the least satisfactory or acceptable) and direct questions about the side-effects of the procedure. A subsequent prospective study was undertaken on 130 patients undergoing transrectal biopsy with sedation between January 1999 and January 2000.

RESULTS

The mean score for patient discomfort with sedation was 1.5, compared with 3.5 with no sedation. The overall satisfaction score improved from 3.1 to 0.9 with sedation. Complication rates were comparable, although slightly higher overall in the prospective group. Conclusion Sedation can significantly reduce patient discomfort and make the transrectal biopsy a more satisfactory experience for the patient. This is particularly important in the proportion of men who need to be considered for repeat biopsies.

A theoretical description of microdialysis with mass transport coupled to chemical events

A random-walk simulation of microdialysis is used to examine how a reaction that consumes analyte in the medium external to the probe affects the extraction and recovery processes. The simulations suggest that such a reaction can promote the extraction process while simultaneously inhibiting the recovery process, which appears to be consistent with recent experimental evidence of asymmetry in the extraction and recovery of the neurotransmitter, dopamine, during brain microdialysis. This suggests that quantitative microdialysis strategies that rely on the extraction fraction as a measure of the probe recovery value, such as the no-net-flux method, will produce an underestimate of the analyte concentration in the external medium when that analyte is consumed by a reaction in the external medium. Furthermore, if experimental conditions arise under which the kinetics of the reaction are changed, then changes in the extraction and recovery processes are likely to occur as well. The implications of these theoretical findings for the quantitative interpretation of in vivo microdialysis results obtained for the neurotransmitter dopamine are examined.

Changes in the kinetics of dopamine release and uptake have differential effects on the spatial distribution of extracellular dopamine concentration in rat striatum

The objective of this study was to examine whether the limited diffusion distance of dopamine in rat striatum produces spatial heterogeneity in the extracellular dopamine concentration on a dimensional scale of a few micrometers. Such heterogeneity would be significant because it would imply that the concentration of dopamine at a given receptor depends on the receptor's ultrastructural location. Spatially resolved measurements of extracellular dopamine were performed in the striatum of chloral hydrate-anesthetized rats with carbon fiber microdisk electrodes. Dopamine was monitored during electrical stimulation of the nigrostriatal pathway before and after administration of drugs that selectively affect the kinetics of evoked dopamine release and dopamine uptake. The effects of nomifensine (20 mg/kg), L-DOPA (250 mg/kg), and alpha-methyl-p-tyrosine (250 mg/kg) on the amplitude of the stimulation responses were examined. The outcome of these experiments was compared with predictions derived from a mathematical model that combines diffusion with the kinetics of release and uptake. The results demonstrate that the extracellular dopamine concentration is spatially heterogeneous on a micrometer scale and that changing the kinetics of dopamine release and uptake has different effects on this spatial distribution. The impact of these results on brain neurochemistry is considered.

Tibolone prevents atherosclerotic lesion formation in cholesterol-fed, ovariectomized rabbits

Tibolone (Org OD14), a synthetic steroid with estrogenic and progestogenic/androgenic properties, is clinically effective for the treatment of climacteric symptoms and the prevention and treatment of osteoporosis in postmenopausal women. The effect on atherogenesis, however, is not known. In the current study, we investigated the effect of tibolone in comparison with that of estradiol and norethisterone acetate on atherogenesis in 140 ovariectomized New Zealand White rabbits that had been induced by an atherogenic diet (0.4% cholesterol, 20 weeks). Tibolone at 18, 6, or 2 mg/d orally completely prevented cholesterol accumulation and fatty streak formation in the aorta; the impairment of endothelium-dependent smooth muscle relaxation of the aorta; and complex lesion formation after endothelial denudation in the carotid artery. Tibolone also reduced the increased postovariectomy plasma lipid concentrations. Analysis of the results, however, indicated that a substantial part of the strong, beneficial effects were plasma lipid independent. Compared with subcutaneous estradiol decanoate (150 microgram once weekly) and oral 17beta-estradiol (4 mg/d), the effects of tibolone were more pronounced at equipotent uterotropic activity. Norethisterone acetate (1 mg/d) did not affect atherosclerotic lesion formation. There are no indications that the progestogenic/androgenic properties of tibolone counteracted its atheroprotective effect on the vessel wall. Therefore, tibolone has the intrinsic potential to be a compound that protects the arterial vessel wall against atherosclerotic processes.

Characterization of tomato PHYB1 and identification of molecular defects in four mutant alleles

The structure of the gene encoding the apoprotein of phytochrome B (PHYB1) in tomato has been determined from genomic and cDNA sequences. In contrast to PHYA, PHYB1 lacks an intron upstream of the first ATG. A single transcription start site was found by 5' RACE at -116. Tomato PHYB1 spans 7 kb starting from the first ATG. The coding region is organized into four exons as for other angiosperm PHY. The deduced apoprotein consists of 1131 amino acids, with a molecular mass of 125.4 kDa. Tomato phytochrome B1 shares 78% and 74% identity with Arabidopsis phytochromes B and D, respectively. Along with the normally spliced full-length transcripts, sequences of reverse transcriptase-PCR clones revealed five types of alternative transcripts. Each type of alternative transcript was missing a considerable part of the coding region, including the chromophore-binding site. The four putative PHYB1 mutants in tomato, which are temporarily red-light insensitive (tri), were each confirmed to have a mutation in PHYB1. Each mutation arose from a different, single-base substitution. Allele tri1 is presumably a null because the mutation introduces a stop at codon 92. In tri3, val-238 is replaced by Phe. The importance of this valine residue is evidenced by the fact that the tri3 phenotype is as strong as that of tri1. Alleles tri2 and tri4 encode proteins truncated at their C-termini. The former lacks either 170 or 438 amino acids, depending upon which of two types of splicing occurs during transcript maturation, while the latter lacks 225.

Coupled effects of mass transfer and uptake kinetics on in vivo microdialysis of dopamine

Voltammetric microelectrodes and microdialysis probes were used simultaneously to monitor extracellular dopamine in rat striatum during electrical stimulation of the medial forebrain bundle. Microelectrodes were placed far away (1 mm) from, immediately adjacent to, and at the outlet of microdialysis probes. In drug-naive rats, electrical stimulation (45 Hz, 25 s) evoked a robust response at microelectrodes far away from the probes, but there was no response at microelectrodes adjacent to and at the outlet of the probes. After nomifensine administration (20 mg/kg i.p.), stimulation evoked robust responses at all three microelectrode placements. These results demonstrate first that evoked release in tissue adjacent to microdialysis probes is suppressed in comparison with evoked release in tissue far away from the probes and second that equilibration of the dopamine concentration in the extracellular fluid adjacent to and far away from the probes is prevented by the high-affinity dopamine transporter. Hence, models of microdialysis, which assume the properties of tissue to be spatially uniform, require modification to account for the distance that separates viable sites of evoked dopamine release from the probe. We introduce new mass transfer resistance parameters that qualitatively explain the observed effects of uptake inhibition on stimulation responses recorded with microdialysis and voltammetry.

The expression of light-regulated genes in the high-pigment-1 mutant of tomato

Three light-regulated genes, chlorophyll a/b-binding protein (CAB), ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit, and chalcone synthase (CHS), are demonstrated to be up-regulated in the high-pigment-1 (hp-1) mutant of tomato (Lycopersicon esculentum Mill. ) compared with wild type (WT). However, the pattern of up-regulation of the three genes depends on the light conditions, stage of development, and tissue studied. Compared with WT, the hp-1 mutant showed higher CAB gene expression in the dark after a single red-light pulse and in the pericarp of immature fruits. However, in vegetative tissues of light-grown seedlings and adult plants, CAB mRNA accumulation did not differ between WT and the hp-1 mutant. The ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit mRNA accumulated to a higher level in the hp-1 mutant than WT under all light conditions and tissues studied, whereas CHS gene expression was up-regulated in de-etiolated vegetative hp-1-mutant tissues only. The CAB and CHS genes were shown to be phytochrome regulated and both phytochrome A and B1 play a role in CAB gene expression. These observations support the hypothesis that the HP-1 protein plays a general repressive role in phytochrome signal transduction.

Further studies of elevated cerebrospinal fluid neuronal cell adhesion molecule in schizophrenia

BACKGROUND

The purposes of the present study were to attempt to replicate a previous finding of increased cerebrospinal fluid (CSF) neuronal cell adhesion molecule (N-CAM) in schizophrenia, and to assess whether the increases could be related to medication, clinical state effects, or brain structural measures.

METHODS

CSF N-CAM was measured by the Western blot technique in 45 DSM-III-R diagnosed male schizophrenic patients both on and off haloperidol treatment and in 20 healthy male control subjects.

RESULTS

CSF N-CAM was significantly increased in schizophrenic patients, with no overlap in the ranges, when compared to controls. There were no significant effects of medication or exacerbation on CSF N-CAM. No associations with measures of brain structure were found.

CONCLUSIONS

Because N-CAM levels were not shown to be different on and off treatment or in exacerbated versus nonexacerbated patients, the higher levels seen in schizophrenic patients may be inherent to the disorder and possibly related to neurodevelopment.

Somatotropin-dependent decrease in fatty acid synthase mRNA abundance in 3T3-F442A adipocytes is the result of a decrease in both gene transcription and mRNA stability

Somatotropin (ST) markedly decreases lipogenesis, fatty acid synthase (FAS) enzyme activity and mRNA abundance in pig adipocytes. The present study was conducted to determine whether the decrease in FAS mRNA in 3T3-F442A adipocytes was the result of a decrease in transcription of the FAS gene and/or a change in FAS mRNA stability. Insulin increased the abundance of FAS mRNA 2-13-fold and fatty acid synthesis 3-7-fold. Somatotropin decreased the stimulatory effect of insulin on the abundance of FAS mRNA and lipogenesis by 40-70% and 20-60% respectively. Subsequent run-on analyses demonstrated that the decrease observed in FAS mRNA in response to ST was associated with an 82% decrease in transcription; ST significantly shortened the half-life of FAS mRNA from 35 to 11 h. To corroborate the run-on analyses, cells were stably transfected with a pFAS-CAT5 (in which CAT stands for chloramphenicol acetyltransferase) reporter construct that contained 2195 bp of the 5' flanking region of the rat FAS gene. Insulin treatment increased FAS-CAT activity 4.7-fold. When ST was added to the insulin-containing medium there was an approx. 60% reduction in FAS-CAT activity. In summary, our results indicate that ST decreases FAS mRNA levels and that this is the result of a marked decrease in both transcription of the FAS gene and stability of the FAS mRNA.

GABA and brain abnormalities in schizophrenia

Some recent autopsy studies indicate that gamma-aminobutyric acid (GABA) function is decreased in brain areas that involve some of the well-described structural changes observed in schizophrenia. The current study examined the relationship between CSF and plasma GABA levels and brain structural measures in schizophrenia. Sixty-two drug-free, physically healthy male patients with schizophrenia (DSM-IIIR) were evaluated for plasma and CSF GABA, as well as brain structural measures on CT scans. Plasma levels of GABA were associated with prefrontal sulcal widening and VBRs, but not global sulcal widening in the schizophrenic patients. CSF GABA measures were not associated with brain structural measures, but were associated with age and age of onset. The significant relationship between plasma GABA, but not CSF GABA, and specific brain morphology measures in schizophrenic patients suggests that if GABA transmission is impaired in schizophrenia, it is a local, but not global, phenomenon.

Modeling voltammetry and microdialysis of striatal extracellular dopamine: the impact of dopamine uptake on extraction and recovery ratios

Numerical modeling was used as a means to examine the relationship between the outcome of in vivo voltammetry and microdialysis experiments and dopamine concentrations in the extracellular fluid of rat striatum. In the case of microdialysis, quantitative interpretation of results demands knowledge of the in vivo values for the extraction and recovery ratios of the probes toward dopamine. Equality of the extraction and recovery ratios is a necessary condition for the direct application of the no-net-flux method as a quantitative technique. Recent results have suggested that the extraction and recovery ratios are not equal, and this interpretation is now supported by theory. A new relationship between extraction and recovery is proposed.

Direct comparison of the response of voltammetry and microdialysis to electrically evoked release of striatal dopamine

Carbon fiber microelectrodes either were implanted directly into striatal tissue or were mounted into the outlet of microdialysis probes that were implanted into striatal tissue. This allowed voltammetry and microdialysis to be used under identical in vivo experimental conditions to monitor extracellular dopamine levels during electrical stimulation of the medial forebrain bundle both before and after uptake inhibition with nomifensine. The marked differences between the results obtained with each technique cannot be explained on the basis of their inherent analytical attributes (sensitivity, temporal response, etc.). The results demonstrate that the microdialysis recovery factor for endogenous dopamine increases after uptake inhibition, an observation that stands in contradiction to the existing theory and practice of the microdialysis technique. The observations led to the development of a numerical model that rationalizes the observations reported herein and that allows in vivo voltammetry and in vivo microdialysis results to be interpreted within a single theoretical framework.

Relation between contractile reserve and positron emission tomographic patterns of perfusion and glucose utilization in chronic ischemic left ventricular dysfunction: implications for identification of myocardial viability

OBJECTIVES

This study sought to determine the incidence and extent of dobutamine-induced contractile reserve in myocardial regions characterized by classical and new positron emission tomographic (PET) patterns in patients with chronic ischemic left ventricular dysfunction.

BACKGROUND

PET is considered the most accurate method for assessment of myocardial viability, which is traditionally identified by perfusion-metabolism mismatch.

METHODS

In 23 patients, segmental wall thickening expressed by four echocardiographic scores at rest and during low dose (5 and 10 microg/kg body weight per min) dobutamine infusion and regional myocardial uptake of potassium-38 and fluorine-18 fluorodeoxyglucose (F-18 FDG) during glucose clamp were compared in 16 corresponding segments.

RESULTS

Of a total of 368 segments, data analysis focused on 214 (58%) dyssynergic segments at baseline. Contractile reserve was identified with increasing incidence according to the six following PET patterns: 1) diminished perfusion and moderate reduction of F-18 FDG uptake (3 [11%] of 28 segments); 2) proportional reduction of perfusion and F-18 FDG uptake (10 [23%] of 43 segments); 3) perfusion-metabolism mismatch (19 [46%] of 41 segments); 4) preserved perfusion but moderate reduction of F-18 FDG uptake (13 [46%] of 27 segments); 5) preserved perfusion and F-18 FDG uptake (37 [59%] of 63 segments) compared with our normal database; and 6) normal perfusion but absolute increased F-18 FDG uptake (8 [73%] of 11 segments). In the latter category, only 7 of 24 segments had normal rest function. In dyssynergic segments with F-18 FDG uptake > or = 50% supplied by vessels with > or = 75% stenosis, improvement in contractility during dobutamine correlated with the presence of collateral channels.

CONCLUSIONS

Myocardial regions with the traditional mismatch pattern of viability show contractile reserve in slightly < 50%. In segments with moderate reduction of F-18 FDG uptake, the contractile response to dobutamine is linked to the level of rest perfusion. Most segments with preserved perfusion and increased F-18 FDG uptake have impaired rest function, but contractile reserve is still present. These data suggest that in chronic ischemic left ventricular dysfunction, myocardial hibernation is a heterogeneous condition.

Porcine somatotrophin differentially down-regulates expression of the GLUT4 and fatty acid synthase genes in pig adipose tissue

The present study was conducted to determine whether porcine somatotropin (pST) differentially regulates expression of the GLUT4 and fatty acid synthase (FAS) genes in pig adipose tissue. Three different experiments were conducted in which pigs were treated daily with different doses of pST for different time periods (7 or 14 d and from 60 to 90 kg of body wt). In these experiments, pST significantly and consistently decreased FAS mRNA levels (80%, 66% and 85%, respectively); however, GLUT4 mRNA was not affected by pST in two of the three experiments, and in the one showing an effect (Experiment 2), the decrease was less than observed for FAS (44%). Because of these results, we conducted subsequent experiments to see if the effects of pST on glucose metabolism in cultured pig adipose tissue (48 h) differed when glucose concentrations were changed from 1 to 5 mmol/L. These studies revealed that the antagonistic effect of pST on insulin action was more potent when glucose transport was saturated (5 mmol/L) than when glucose concentration limited glucose entry into the cell (1 mmol/L). In summary, these results suggest that the effects of pST on glucose transport in pig adipocytes are secondary to changes elicited by the hormone on intracellular glucose use for lipogenesis. When considered in the context of the decrease previously observed in glucose transport in pig adipocytes, the findings reported herein suggest that pST acts to decrease GLUT4 protein activity and/or distribution between the plasma membrane and the intracellular pool with little alteration in GLUT4 gene expression or total cell GLUT4 protein.

Predicting haloperidol treatment response in chronic schizophrenia

The study attempted to identify pretreatment characteristics of chronic schizophrenic patients that would predict remission in psychosis and amount of clinical improvement after treatment with haloperidol. Thirty-five acutely relapsed schizophrenic patients were entered into a blind 6-week treatment protocol. Pretreatment measures were assessed for prediction of both remission status (dichotomous) and for correlations with change in psychopathology (continuous). Later age of onset and higher plasma homovanillic acid values were significant predictors of remission status (model 1). However, higher cerebrospinal fluid levels of 3-methoxy-4-hydroxyphenylglycol, as well as indices of normal neurodevelopment, predicted larger changes in psychopathology. The results indicate that the definition of drug response determines the predictive variables. Dopaminergic activity seems to relate to the ability to reach remission, while noradrenergic activity relates to symptom intensity and reduction. In addition to catecholamine activity, neurodevelopmental changes determine response to haloperidol.

Developmental and light-regulated expression of individual members of the light-harvesting complex b gene family in Pinus palustris

Angiosperms requires light for multiple aspects of chloroplast development, including chlorophyll synthesis and induction of expression of the mRNAs encoding the major polypeptides of the light-harvesting complex of photosystem II (Lhcb genes). In contrast, many conifers, including pines, firs, and spruces, can accumulate chlorophyll and the light-harvesting chlorophyll a/b-binding proteins of photosystem II in complete darkness. To understand the factors responsible for the regulation of expression of individual Lhcb mRNAs in the pine Pinus palustris, we have prepared sequence-specific cDNA probes for each of three family members, Lhcb1*Pp1, Lhcb2*Pp1, and Lhcb2*Pp2, and have studied the expression of two of these, Lhcb1*Pp1 and Lhcb2*Pp2, in detail. The levels of expression of each sequence were disparate, and Lhcb1*Pp1-encoded transcripts were the most abundant in the light. Both Lhcb1*Pp1 and Lhcb2*Pp2 mRNAs were expressed in stems and cotyledons, but Lhcb1*Pp1 mRNA was present at about 10-fold lower levels in stems than in cotyledons, in contrast to Lhcb2*Pp2 mRNA, which was expressed at higher levels in stems than in cotyledons. Both Lhcb1*Pp1 and Lhcb2*Pp2 mRNAs were absent in embryos but were expressed during seedling development. The levels increased with age in both the light and the dark and in both cases were about 2-fold higher in the light than in the dark. Despite the expression of Lhcb1*Pp1 and Lhcb2*Pp2 mRNAs during development in darkness, the levels of both mRNAs increased in dark-grown seedlings given red light in the low fluence range within 2 h of treatment.

Monitoring body-core temperature from the trachea: comparison between pulmonary artery, tympanic, esophageal, and rectal temperatures

INTRODUCTION

We designed an endotracheal tube (ETT) for acquiring body-core temperature from the trachea. This ETT had two temperature sensors, one attached to the inside surface of the cuff, the other mounted on the ETT shaft underneath the cuff. The ETT was evaluated in vitro and in dogs to determine: 1) optimal position of temperature sensors and 2) the responsiveness, accuracy, and resistance to ventilatory artifacts.

METHODS

In vitro. An artificial trachea assessed the response-time and accuracy of ETT temperature sensors to abrupt temperature changes and ventilatory flow-rates. In vivo. Body temperature in 5 dogs was lowered to approximately 26 degrees C then elevated toward 39 degrees C using a heat exchanger during carotid-jugular bypass. ETT temperature measurements were compared simultaneously with those from the artificial trachea (in vitro) or from the pulmonary artery, tympanic cavity, esophagus, and rectum of dogs using dry and humidified gas.

RESULTS

Cuff temperature sensor responded quickly and accurately to temperature changes and was less prone than the tube sensor to ventilatory and humidity artifacts. During carotid-jugular bypass, in vivo tube and cuff mean temperatures averaged 1.4 degrees C and 0.36 degree C lower, respectively, than pulmonary artery temperatures. There were no statistical differences (P > 0.05) between cuff temperatures and those measured from the pulmonary artery, tympanic cavity, esophagus, and rectum. Heating and humidifying the inspiratory gas of dogs with a water-bath humidifer or heat moisture exchanger (HME) had minimal effects on the cuff temperature sensor. An in-line HME increased in vivo tube temperature from baseline values by 1.13 +/- 0.80 degree C, while cuff temperature increased by 0.21 +/- 0.24 degree C.

CONCLUSION

The cuff of the ETT is a reliable site for measuring body-core temperature in intubated patients.

The growth hormone-dependent decrease in hepatic fatty acid synthase mRNA is the result of a decrease in gene transcription

The present study was conducted to determine the chronic effects of porcine growth hormone administration on fatty acid synthase (FAS) mRNA abundance and gene transcription in growing rats. Growth hormone treatment increased growth rate approximately 27% (P<0.01). Porcine growth hormone decreased FAS mRNA levels by 55%. The reduction in FAS mRNA was due to a marked decrease in transcription of the FAS gene (decreased by 80%). In contrast, porcine growth hormone did not affect mRNA abundance or transcription rate of another insulin-regulated gene, phosphoenolpyruvate carboxykinase. In summary, our results have established that chronic treatment with growth hormone decreases FAS mRNA by decreasing the transcription rate of the gene. Furthermore, they suggest that the effects of growth hormone are specific and are not mediated by general changes in insulin-responsive gene expression in liver.

Predicting duration of clinical stability following haloperidol withdrawal in schizophrenic patients

Although chronic maintenance antipsychotic drug treatment is the most effective way of preventing relapse in schizophrenic patients, it is not very successful. A considerable number of patients relapse on medication, and many others do not take their medications as prescribed after leaving the hospital. Unfortunately, clinicians are not able to identify how long patients will remain clinically stable after drug discontinuation. To develop a model consisting of behavioral and monoaminergic variables to identify the risk of symptom exacerbation, we obtained in the week prior to haloperidol discontinuation global behavioral ratings and cerebrospinal fluid (CSF) values for monoamine metabolites in a sample of 109 DSM-III-R schizophrenic patients. Patients were followed until specific criteria for increases in psychosis were met for up to 1 year and then returned to antipsychotic drug treatment. Cox regression analysis identified predictors of the survival function, or the probability of relapse at a given time drug free. The best model indicated that increased psychosis, decreased anxiety, an increased CSF homovanillic acid (HVA) to 5-hydroxyindoleacetic acid (5-HIAA) ratio, and decreased CSF 3-methoxy-4-hydroxyphenylglycol (MHPG) prior to haloperidol withdrawal were associated with early increases in psychosis. Our study indicates that it is possible to identify those patients who are more likely to remain clinically stable without medication. When the model is validated, it will help clinicians assess the relapse risk over time, lower doses in treatment-resistant patients, and possibly determine the optimal time for aftercare visits following hospital discharge.

Regulatory effects of endogenous interleukin-1 receptor antagonist protein in immunoglobulin G immune complex-induced lung injury

IL-1 receptor antagonist (IL-1Ra) has regulatory effects on IL-1 activity both in vitro and in vivo. In the IgG immune complex model of lung injury in rats, exogenously administered human IL-1Ra suppressed neutrophil recruitment and ensuing lung injury. In this study, we sought to determine if endogenous rat IL-1Ra might regulate this lung-inflammatory response. By Northern blot analysis of lung mRNA and Western analysis of bronchoalveolar lavage (BAL) fluids, rat IL-1Ra expression was found to increase during development of inflammation in IgG immune complex-mediated alveolitis. By immunostaining, alveolar macrophages and recruited neutrophils were the apparent sources of IL-1Ra. In vivo blocking of endogenous IL-1Ra resulted in a 53% increase in lung vascular permeability and a 180% increase in BAL fluid neutrophils. In companion studies, a significant increase in IL-1beta was found, whereas no significant change in TNF-alpha activity was observed. Whereas the in vivo regulatory effects of IL-1R appear to be limited to IL-1beta, IL-10 regulates both IL-1beta and TNF-alpha in this model, reflected by a 48% increase in BAL IL-1beta in rats treated with anti-IL-10. These findings suggest that IL-1Ra is an intrinsic regulator of inflammatory injury after deposition of IgG immune complexes and that it regulates production of IL-1beta.

Involvement of N-methyl-D-aspartate receptor using excitatory amino acid neurotransmitters in control of pulsatile secretion of LH during sexual development in Holstein bull calves

The neuroendocrine mechanisms underlying the development of pulsatile release of LH in bull calves are poorly understood. The hypothesis that endogenous excitatory amino acids, working through N-methyl-D-aspartate (NMDA) receptors, are involved in the generation of pulsatile LH release during sexual maturation of bull calves was tested. Holstein bull calves were administered i.v. 0.001, 0.01 and 0.1 mg kg-1 body mass of MK-801, a specific noncompetitive NMDA receptor antagonist, on alternate days at 1, 12 and 24 weeks of age (n = 6 per dose), using a replicated 3 x 3 latin square design. Blood samples were obtained from jugular catheters at intervals of 10 min for 2 h before and 2 h after MK-801 treatment at 1 week and for periods of 4 h before and after MK-801 administration at 12 and 24 weeks of age. Plasma concentrations of LH were measured by a specific radioimmunoassay and pulsatile LH secretion was analysed using the Pulsar algorithm. Basal LH secretion at 1 week of age was low but was increased by 12 weeks (0.38 +/- 0.01 versus 1.38 +/- 0.11 ng ml-1; P < 0.001) with the establishment of frequent high amplitude pulses. Mean LH concentrations and pulse amplitude, but not frequency, were lower at 24 than at 12 weeks of age (0.88 +/- 0.08 versus 1.38 +/- 0.11 ng ml-1: P < 0.001, 1.74 +/- 0.14 versus 2.82 +/- 0.36 ng ml-1: P < 0.01, and 1.70 +/- 0.30 versus 1.70 +/- 0.41 in 4 h: P > 0.05, respectively). Administration of MK-801 did not affect LH secretion in 1- and 12-week-old calves.(ABSTRACT TRUNCATED AT 250 WORDS)

Increases in CSF levels of interleukin-2 in schizophrenia: effects of recurrence of psychosis and medication status

OBJECTIVE

Interleukin-2, traditionally viewed as solely involved in immunological events, has recently been shown to exert profound effects on the development and regulation of the central nervous system. This study examined the relationships between interleukin-2 in the CSF and plasma of schizophrenic patients and clinical measures, including relapse and medication status. Plasma and CSF interleukin-1 alpha levels were also measured to ascertain the specificity of changes in cytokine levels.

METHODS

Seventy-nine physically healthy male patients with schizophrenia (DSM-III-R) received diagnostic evaluation and behavioral ratings. Haloperidol treatment was withdrawn for up to 6 weeks and patients were evaluated for symptom recurrence. CSF and plasma were obtained by established procedures before haloperidol withdrawal (N = 79) and after (N = 64).

RESULTS

CSF levels of interleukin-1 alpha decreased significantly after haloperidol withdrawal but showed no relation to clinical status. In contrast, levels of CSF interleukin-2 were associated with recurrence of psychotic symptoms. Relapse-prone patients, examined both while medicated and after drug withdrawal, had significantly higher levels of CSF interleukin-2 than patients who did not relapse. CSF interleukin-2 level during haloperidol treatment was a significant predictor of worsening in psychosis.

CONCLUSIONS

Levels of interleukin-2, a molecule that plays both neurodevelopmental and neuroregulatory roles, may have a role in relapse in schizophrenia. Levels of CSF interleukin-2 appear to be affected by relapse mechanisms, while peripheral blood levels are not. These changes are specific to interleukin-2, since levels of interleukin-1 alpha were affected by medication withdrawal but not by change in clinical state.