Association between CYP2D6 *10 genotype and survival of breast cancer patients receiving tamoxifen treatment

BACKGROUND

Human cytochrome P450 2D6 (CYP2D6) genotype may affect the efficacy of tamoxifen treatment in Caucasian women with breast cancer. The most common polymorphism of CYP2D6 in Chinese women is variant 10 (188 C to T).

PATIENTS AND METHODS

Tamoxifen and 4-hydroxytamoxifen (4OHtam) were measured in the serum of 37 women with breast cancer who were receiving tamoxifen treatment. The association between CYP2D6 *10 genotype and survival was determined in a cohort of 293 women with breast cancer who received tamoxifen (n = 152) or who did not (n = 141).

RESULTS

The serum 4OHtam concentrations were significantly lower in women with the CYP2D6 *10 homozygous variant T/T genotype than in those with the homozygous wild-type C/C genotype (P = 0.04). Among tamoxifen-treated women, women with the T/T genotype had a significantly worse disease-free survival (DFS) than those with the C/C or C/T genotype, and the T/T genotype remained an independent prognostic factor of DFS in multivariate analysis (hazard ratio = 4.7; 95% confidence interval = 1.1-20.0; P = 0.04). Among women who did not receive tamoxifen, there was no significant association between CYP2D6 *10 genotype and survival.

CONCLUSION

In tamoxifen-treated patients, women with the CYP2D6 *10 T/T genotype have a lower 4OHtam level in the serum and a worse clinical outcome.

Low polarization dependent diffraction grating for wavelength demultimlexing

A low polarization dependent, high diffraction efficiency grating for wavelength demultiplexer is proposed, manufactured by standard crystallographic etching of Si surface. Light is incident and diffracted inside the wafer, which is covered with reflecting metal. Optimized groove form results in a flat spectral response for TE and TM polarizations.

Lsh, a member of the SNF2 family, is required for genome-wide methylation

Methylation patterns of the mammalian genome are thought to be crucial for development. The precise mechanisms designating specific genomic loci for methylation are not known. Targeted deletion of Lsh results in perinatal lethality with a rather normal development. We report here, however, that Lsh(-/-) mice show substantial loss of methylation throughout the genome. The hypomethylated loci comprise repetitive elements and single copy genes. This suggests that global genomic methylation is not absolutely required for normal embryogenesis. Based on the similarity of Lsh to other SNF2 chromatin remodeling proteins, it suggests that alteration of chromatin affects global methylation patterns in mice.

A novel strategy for organ allografts using sublethal (7 Gy) irradiation followed by injection of donor bone marrow cells via portal vein

A new strategy for organ allografts that does not require recourse to immunosuppressants is established in mice. The strategy includes sublethal (7 Gy) irradiation followed by the injection of donor bone marrow cells (BMCs) via the portal vein (P.V.) and organ allografts 1 day after irradiation. Irradiation doses (< or =7 Gy) are found to allow the recipients to survive without the need to reconstitute the BMCs, as the recipient hematolymphoid cells can gradually recover. One hundred percent of recipients irradiated with 7 Gy followed by either P.V. or i.v. injection of donor BMCs accept organ allografts (the skin, pancreas, and adrenal glands) for more than 1 year. However, organ allograft survival rates decrease when irradiation doses are reduced; the skin graft survival rate of mice treated with 6.5 Gy and P.V. injection of BMCs is 79%, whereas that of mice treated with 6.5 Gy and i.v. injection is 50%, indicating that the P.V. injection of BMCs induces persistent tolerance more effectively than the i.v. injection. H-2 typing reveals that almost all the hematolymphoid cells (>98%) in the peripheral blood and hematolymphoid organs are donor-derived even 1 year after the treatment (7 Gy and P.V.). The T cells are tolerant to both donor-type and host-type MHC determinants. The major mechanism underlying the persistent tolerance induced by this strategy seems to be because of clonal deletion. This simple and safe strategy would be of great advantage for human organ transplantation.

Isolation, characterization, and mapping of a novel human KRAB zinc finger protein encoding gene ZNF463

A novel human KRAB (Krüppel associated box) type zinc finger protein encoding gene, ZNF463, was obtained by mRNA differential display and RACE. It consists of 1904 nucleotides and encodes a protein of 463 amino acids with an amino-terminal KRAB domain and 12 carboxy-terminal C2H2 zinc finger units. The gene is mapped to chromosome 19q13.3 approximately 4 by FISH. As from Northern blot analysis ZNF463 is only expressed in testis, RT-PCR indicates that ZNF463 is expressed more highly in normal fertile adults than in fetus and azoospermic patients suggesting that it may play a role in human spermatogenesis.

Oligomerization of mu- and delta-opioid receptors. Generation of novel functional properties

The existence of dimers and oligomers for many G protein-coupled receptors has been described by us and others. Since many G protein-coupled receptor subtypes are highly homologous to each other, we examined whether closely related receptors may interact with each other directly and thus have the potential to create novel signaling units. Using mu- and delta-opioid receptors, we show that each receptor expressed individually was pharmacologically distinct and could be visualized following electrophoresis as monomers, homodimers, homotetramers, and higher molecular mass oligomers. When mu- and delta-opioid receptors were coexpressed, the highly selective synthetic agonists for each had reduced potency and altered rank order, whereas endomorphin-1 and Leu-enkephalin had enhanced affinity, suggesting the formation of a novel binding pocket. No heterodimers were visualized in the membranes coexpressing mu- and delta-receptors by the methods available. However, hetero-oligomers were identified by the ability to co-immunoprecipitate mu-receptors with delta-receptors and vice versa using differentially epitope-tagged receptors. In contrast to the individually expressed mu- and delta-receptors, the coexpressed receptors showed insensitivity to pertussis toxin and continued signal transduction, likely due to interaction with a different subtype of G protein. In this study, we provide, for the first time, evidence for the direct interaction of mu- and delta-opioid receptors to form oligomers, with the generation of novel pharmacology and G protein coupling properties.

Degradation of transcription factor RFX5 during the inhibition of both constitutive and interferon gamma-inducible major histocompatibility complex class I expression in chlamydia-infected cells

We have previously shown that the obligate intracellular pathogen chlamydia can suppress interferon (IFN)-gamma-inducible major histocompatibility complex (MHC) class II expression in infected cells by degrading upstream stimulation factor (USF)-1. We now report that chlamydia can also inhibit both constitutive and IFN-gamma-inducible MHC class I expression in the infected cells. The inhibition of MHC class I molecule expression correlates well with degradation of RFX5, an essential downstream transcription factor required for both the constitutive and IFN-gamma-inducible MHC class I expression. We further demonstrate that a lactacystin-sensitive proteasome-like activity identified in chlamydia-infected cell cytosolic fraction can degrade both USF-1 and RFX5. This proteasome-like activity is dependent on chlamydial but not host protein synthesis. Host preexisting proteasomes may not be required for the unique proteasome-like activity. These observations suggest that chlamydia-secreted factors may directly participate in the proteasome-like activity. Efforts to identify the chlamydial factors are underway. These findings provide novel information on the molecular mechanisms of chlamydial evasion of host immune recognition.

Development of mouse dendritic cells from lineage-negative c-kit(low) pluripotent hemopoietic stem cells in vitro

Dendritic cells (DCs) are essential for the presentation of antigens in the primary immune response. To examine the generation of DCs from hemopoietic stem cells in the bone marrow (BM), lineage-negative (Lin-)/CD71- bone marrow cells (BMCs) from C57BL/6 mice were separated into major histocompatibility complex (MHC) class Ihigh/ c-kit(low) and MHC class Ihigh/c-kit(low)(phenotypically c-kit-negative, but c-kit message only detected by reverse transcriptase-polymerase chain reaction) populations. A large number of cells with the morphological, phenotypical, and functional characteristics of DCs was generated from both c-kit(low) and c-kit(low) populations when cultured with a combination of cytokines (GM-CSF, tumor necrosis factor-a [TNF-a], interleukin 7 [IL-7], IL-3, stem cell factor [SCF], and flt3 ligand); the cytokine combination studies revealed that SCF and IL-3 in addition to GM-CSF and TNF-a are essential for DCs to be generated from these primitive populations. To our surprise most (>80%) generated cells expressed high levels of DC surface markers such as DEC205 and MHC class II, and they were potent stimulators in the primary allogeneic T cell activation. The development of DCs from c-kit(<low) cells was slower than that from c-kit(low) cells. These results indicate that c-kit(<low) cells are more primitive than c-kit(low) cells, although both c-kit*(low) cells and c-kit(<low) cells can differentiate into DCs. It should be noted that the combination of these cytokines selectively induces DCs from both c-kit(<low) and c-kit(low) cells in vitro, suggesting that the ex vivo expansion of DCs using these primitive cells would be applicable to immunotherapy.

Characterization of apelin, the ligand for the APJ receptor

The apelin peptide was recently discovered and demonstrated to be the endogenous ligand for the G protein-coupled receptor, APJ. A search of the GenBank databases retrieved a rat expressed sequence tag partially encoding the preproapelin sequence. The GenBank search also revealed a human sequence on chromosome Xq25-26.1, containing the gene encoding preproapelin. We have used the rat sequence to screen a rat brain cDNA library to obtain a cDNA encoding the full-length open reading frame of rat preproapelin. This cDNA encoded a protein of 77 amino acids, sharing an identity of 82% with human preproapelin. Northern and in situ hybridization analyses revealed both human and rat apelin and APJ to be expressed in the brain and periphery. Both sequence and mRNA expression distribution analyses revealed similarities between apelin and angiotensin II, suggesting they that share related physiological roles. A synthetic apelin peptide was injected intravenously into male Wistar rats, resulting in immediate lowering of both systolic and diastolic blood pressure, which persisted for several minutes. Intraperitoneal apelin injections induced an increase in drinking behavior within the first 30 min after injection, with a return to baseline within 1 h.

Experimental study of the protection of ischemic preconditioning to spinal cord ischemia

BACKGROUND

Since the advent of ischemic preconditioning in myocardium, more and more attention has been paid to ischemic preconditioning in the central nervous system (CNS). This study was designed to evaluate the protective effect of ischemic preconditioning on spinal cord ischemia.

METHODS

Interventional neuroradiological techniques were used to induce spinal cord ischemia in a rabbit model. Hydrogen electrode technique was used to determine the regional blood flow of the spinal cord. Catecholamines and their metabolites were measured by high performance liquid chromatography (HPLA). Spinal cord evoked potentials were recorded to show spinal cord neurofunction.

RESULTS

After 5 minutes ischemic preconditioning with 20 minutes reperfusion, the regional spinal cord blood flow (rSCBF) was increased, as may be seen by the slight increase of catecholamine, especially NE. This is in positive proportion to the cAMP and indicates the enhancement of the metabolic activities of the spinal cord. After 30 minutes of irreversible ischemia, the great increase in catecholamine caused vascular spasm, endotheliocyte fissure, multiple hemorrhagic suffusion, and necrosis, which would injure the spinal cord as a result. The slight increase of the rSCBF and the maintenance of the rSCBF after irreversible ischemia may enhance the protection of ischemic preconditioning to the spinal cord neurofunction, which was proved by spinal cord evoked potentials (SCEPs).

CONCLUSIONS

Our study showed that 5 minutes of ischemic preconditioning can increase the rSCBF, enhance the tolerance of the spinal cord to irreversible ischemia, and protect the neurofunction of the spinal cord. The biological mechanism of the protective effect of ischemic preconditioning to spinal cord ischemia should be further studied.

[Cloning of the idiopathic azoospermia related genes with mRNA differential display method]

OBJECTIVE

Defect of some genes related to spermatogenesis may result in male infertility with azoospermia. This study aimed to clone some of the genes.

METHODS

Testis tissues from a patient with idiopathic azoospermia and from a normal fathered man were investigated with an improved mRNA differential display approach.

RESULTS

Significant difference was observed between the two tissues in gene expression. Five differential expressed sequence-tags (ESTs) were cloned and sequenced. Homology analysis with software advanced BLAST 2.0 showed that one EST shared 100% homology with cosmid L27h9, which located in Huntington's disease region on 4p16.3; the other 4 showed very low homology with sequences in GenBank.

CONCLUSION

Azoospermia has complex genetic heterogeneity. A gene located in Huntington's disease region on 4p16.3 is expressed in human testis during the spermatogenesis, and a loss of its function may associate with azoospermia.

Chlamydia inhibits interferon gamma-inducible major histocompatibility complex class II expression by degradation of upstream stimulatory factor 1

We report that chlamydiae, which are obligate intracellular bacterial pathogens, can inhibit interferon (IFN)-gamma-inducible major histocompatibility complex (MHC) class II expression. However, the IFN-gamma-induced IFN regulatory factor-1 (IRF-1) and intercellular adhesion molecule 1 (ICAM-1) expression is not affected, suggesting that chlamydia may selectively target the IFN-gamma signaling pathways required for MHC class II expression. Chlamydial inhibition of MHC class II expression is correlated with degradation of upstream stimulatory factor (USF)-1, a constitutively and ubiquitously expressed transcription factor required for IFN-gamma induction of class II transactivator (CIITA) but not of IRF-1 and ICAM-1. CIITA is an obligate mediator of IFN-gamma-inducible MHC class II expression. Thus, diminished CIITA expression as a result of USF-1 degradation may account for the suppression of the IFN-gamma-inducible MHC class II in chlamydia-infected cells. These results reveal a novel immune evasion strategy used by the intracellular bacterial pathogen chlamydia that improves our understanding of the molecular basis of pathogenesis.

c-kit<low Pluripotent hemopoietic stem cells form CFU-S on day 16

Using Ly5 congenic mice, we characterized the early differentiation step of pluripotent hemopoietic stem cells. Lineage- (Lin-)/CD71- cells in the bone marrow cells were separated into major histocompatibility complex (MHC) class I(high)/c-kit(low) and MHC class I(high)/c-kit<low populations from C57BL/6 Ly5.1 male mice. These two populations (1,000 cells) were transplanted into lethally irradiated (5.5 Gy x 2) C57BL/6 Ly5.2 female mice. Colony-forming unit in spleen (CFU-S) assays were carried out on days 10, 12, 14, 16, and 20. In the mice that received c-kit(low) cells, CFU-S were first detected on day 12, and the CFU-S counts gradually increased. In contrast, no visible colony was detected until day 14 in the mice that received c-kit<low cells; CFU-S were first observed on day 16. Donor-derived (Ly5.1+) cells, such as B cells, T cells, and myeloid cells, were detected by fluorescence-activated cell sorter analyses, and donor-derived erythroid cells were detected by polymerase chain reaction analyses using Y-chromosome-specific primers. Donor-derived cells in the recipients of c-kit(low) cells were detected in the spleen, bone marrow, and peripheral blood on day 12 after transplantation, while they were detected on day 16 in the mice that received c-kit<low cells. Therefore, c-kit<low cells have the capacity not only to form CFU-S on day 16 but also to reconstitute the recipients with donor-derived hematolymphoid cells 16 days after transplantation.

Disruption of dopamine D1 receptor gene expression attenuates alcohol-seeking behavior

The role of the dopamine D1 receptor subtype in alcohol-seeking behaviors was studied in mice genetically deficient in dopamine D1 receptors (D1 -/-). In two-tube free choice limited (1-5 h) and continuous (24 h) access paradigms, mice were exposed to water and increasing concentrations of ethanol (3%, 6% and 12% w/v). Voluntary ethanol consumption and preference over water were markedly reduced in D1 -/- mice as compared to heterozygous (D1 +/-) and wild-type (D1 +/+) controls, whereas overall fluid consumption was comparable. When offered a single drinking tube containing alcohol as their only source of fluid for 24 h, D1 -/- mice continued to drink significantly less alcohol than D1 +/+ and D1 +/- mice. Dopamine D2 receptor blockade with sulpiride caused a small but significant reduction in alcohol intake and preference in D1 +/+ mice and attenuated residual alcohol drinking in D1 -/- mice. Dopamine D1 receptor blockade with SCH-23390 very effectively reduced alcohol intake in D1 +/+ and D1 +/- mice to the level seen in untreated D1 -/- mice. These findings suggest involvement of both dopamine D1 and D2 receptor mechanisms in alcohol-seeking behavior in mice; however, these implicate D1 receptors as having a more important role in the motivation for alcohol consumption.

The influence of impaired microvasculature on regional blood flow of the spinal cord after microsurgery

OBJECTIVE

To further investigate the impact of impaired microvasculature of spinal cord and its physiological compensation on postoperative morbidity after intramedullary microsurgery.

METHODS

In 120 cats, the segmental anterior longitudinal spinal arteries (ALSA), the posterior longitudinal spinal arteries (PLSA), and the unilateral radiculomedullary arteries (RMA) were selectively coagulated in different patterns. Hydrogen electrode technique was used to detect the changes of regional blood flow of the spinal cord at different segments. Benzidine dihydrochloride (BDHC) staining was used to observe the microvascular pattern of the spinal cord, tetrazolium chloride (TTC) staining was applied to morphometric analysis of the ischemic area, and hematoxylin-eosin staining was applied to histologic examination.

RESULTS

When the segmental ALSA was injured, the blood flow of the gray matter and white matter decreased greatly. Since the central arteries were the terminal blood supply arteries, no compensation occurred after the injury. The blood flow of the segment below the impaired segment hardly changed, indicating that the direction of the blood flow in ALSA altered to adapt the changes of the microvasculature. Injury to the unilateral PLSA and RMA at both cervical and lumbar area only caused a minor decrease in the regional blood flow, unless the perimedullary arterial system was considerably injured. In the thoracic medullary segment, the sparse microvasculature was the main cause for the segment vulnerable to ischemia and infarction. This was caused by not only the rarity of RMA as an anatomic factor, but also the small number and low activity of the neurons at this area. After microsurgery, the impairment and decompensation of the microvasculature were closely related to the ischemic volume of and pathological changes in the spinal cord.

CONCLUSION

The impairment and decompensation of microvasculature after microsurgery are the rudimentary causes of spinal cord ischemia. During operation, one should protect the terminal arteries to decrease the severity of injury to the perimedullary system, and do the best to avoid disturbance of microvasculature to accelerate the recovery of postoperative ischemia and neurological dysfunction of the spinal cord.

Inhibition of apoptosis in chlamydia-infected cells: blockade of mitochondrial cytochrome c release and caspase activation

We report that chlamydiae, which are obligate intracellular bacterial pathogens, possess a novel antiapoptotic mechanism. Chlamydia-infected host cells are profoundly resistant to apoptosis induced by a wide spectrum of proapoptotic stimuli including the kinase inhibitor staurosporine, the DNA-damaging agent etoposide, and several immunological apoptosis-inducing molecules such as tumor necrosis factor-alpha, Fas antibody, and granzyme B/perforin. The antiapoptotic activity was dependent on chlamydial but not host protein synthesis. These observations suggest that chlamydia may encode factors that interrupt many different host cell apoptotic pathways. We found that activation of the downstream caspase 3 and cleavage of poly (ADP-ribose) polymerase were inhibited in chlamydia-infected cells. Mitochondrial cytochrome c release into the cytosol induced by proapoptotic factors was also prevented by chlamydial infection. These observations suggest that chlamydial proteins may interrupt diverse apoptotic pathways by blocking mitochondrial cytochrome c release, a central step proposed to convert the upstream private pathways into an effector apoptotic pathway for amplification of downstream caspases. Thus, we have identified a chlamydial antiapoptosis mechanism(s) that will help define chlamydial pathogenesis and may also provide information about the central mechanisms regulating host cell apoptosis.

The relationship between the vas volume and the anatomic size of the vas deferens

The anatomic sizes of 210 vas segments from 107 volunteers of vasectomy were measured by computerized image graphic technique with microphotography. The mean equivalent-round, outer and inner diameters of the vas were 2.17 +/- 0.20 mm and 0.56 +/- 0.08 mm, respectively. The calculated thickness of vas wall was 0.81 +/- 0.21 mm. The maximal volumes of 124 vas segments (1 cm in length) were tested by injecting colored solution into vas lumen until vas rupture. The mean rupture volume of 1 cm vas lumen was 0.05 +/- 0.007 mL. A significant influence of the thickness of vas wall (p < 0.05) and body height (p < 0.05) on the rupture volume was noticed in stepwise regression analysis. A tunnel-like rupturing pattern was observed in morphological observation. The obtained rupture volume provides a security line in determining the injection volume of occlusive material or the size of the implanted contraceptive device.

Airway responsiveness in two inbred strains of mouse disparate in IgE and IL-4 production

The mouse provides an excellent model for genetic studies of asthma, which is characterized by airway hyperexcitability and hyperreactivity. The former is a function of the properties of the membrane of the airway smooth muscle (ASM), whereas the latter is a function, albeit indirectly, of the mechanical properties of the muscle contractile apparatus. The very small size of the muscle has in the past hampered its study. We report herein that contractile properties of tracheal smooth muscle (TSM) can be measured in mice. We examined TSM strips from two inbred strains of mouse, ASW and SJL, which are high and low IgE responders, respectively. Force-velocity relationships were measured in four groups of mice, two ASW (control and sensitized)/and two SJL (control and sensitized). Muscle strips from sensitized SJL mice exhibited shortening velocities (V0) and maximum shortening capacities (deltaLmax), that were significantly greater than those of the other groups. However, no difference was found between the two strains in maximal isometric force (P0). The two strains also showed differences in their potential to express cytokines such as interleukin-4 (IL-4) and IL-5 in ex vivo splenocyte cultures, as measured by the cytokines' messenger RNA (mRNA) and protein expression. The SJL strain, which exhibited TSM hyperreactivity, was found to produce significantly greater amounts of IL-4 than the ASW strain. We conclude that the altered contractile properties of TSM in sensitized SJL mice are independent of IgE response, but linked to increased amounts of IL-4.

A novel role for vitamin K1 in a tyrosine phosphorylation cascade during chick embryogenesis

The development of the embryo is dependent upon a highly coordinated repertoire of cell division, differentiation, and migration. Protein-tyrosine phosphorylation plays a pivotal role in the regulation of these processes. Vitamin K-dependent gamma-carboxylated proteins have been identified as ligands for a unique family (Tyro 3 and 7) of receptor tyrosine kinases (RTKs) with transforming ability. The involvement of vitamin K metabolism and function in two well characterized birth defects, warfarin embryopathy and vitamin K epoxide reductase deficiency, suggests that developmental signals from K-dependent pathways may be required for normal embryogenesis. Using a chick embryogenesis model, we now demonstrate the existence of a vitamin K1-dependent protein-tyrosine phosphorylation cascade involving c-Eyk, a member of the Tyro 12 family, and key intracellular proteins, including focal adhesion kinase (pp125FAK), paxillin, and pp60src. This cascade is sensitive to alteration in levels or metabolism of vitamin K1. These findings provide a major clue as to why, in the mammalian (and human) fetus, the K-dependent proteins are maintained in an undercarboxylated state, even to the point of placing the newborn at hemorrhagic risk. The precise regulation of vitamin K1-dependent regulatory pathways would appear to be critical for orderly embryogenesis.

Variety of molecular conformation of plasmid pUC18 DNA and solenoidally supercoiled DNA

The plasmid pUC18 DNA isolated from Escherichia coli HB101 were analyzed by two-dimensional agarose gel electrophoresis and hybridization. The results show that the DNA sample can be separated into six groups of different structural components. The plectonemically and solenoidally supercoiled pUC18 DNA coexist in it. These two different conformations of supercoiled DNA are interchangeable with the circumstances (ionic strength and type, etc.). The amount of solenoidally supercoiled pUC18 DNA in the samples can be changed by treatment of DNA topoisomerases. Under an electron microscope, the solenoidal supercoiling DNA has a round shape with an average diameter of 45 nm. The facts suggest that solenoidally supercoiled DNA be a structural entity independent of histones. The polymorphism of DNA structure may be important to packing of DNA in vivo.

[Diagnosis and treatment of interrupted aortic arch: report of 6 cases]

Six patients with interrupted aortic arch were operated on from Nov. 1986 to Jun. 1992. 4 patients were type A and 2 type B. The result was good except a patients of type A died early after operation. Two-stage operation was performed for 4 patients of type A, and 2 patients of type B accepted posterolateral incision. The aortic arch was constructed with artificial vessel. Cardiopulmonary bypass was set up with patients lying on back, then PDA was ligated and VSD closed. Pulmonary artery trunk reconstruction and VSD closing were performed. Three months after operation a patient died of septicemia caused by infection of incision.

Low endogenous dopamine function in brain predisposes to high alcohol preference and consumption: reversal by increasing synaptic dopamine

Using inbred strains of mice that differ widely in their innate preference for and consumption of ethanol, we demonstrate, in ethanol-preferring C57BL/6J (C57) mice, decreased dopamine (DA) content and turnover in the terminals of the mesolimbic and mesostriatal dopamine neurons, compared with ethanol-avoiding DBA/2J and BALBc mice. These data suggest that genetically determined hypodopaminergic function in these pathways plays a role in the predisposition to high voluntary intake of ethanol. DA turnover in these areas was selectively increased by ethanol in C57 mice, which suggests that these DA neurons are among the central substrates of ethanol action in brain. In keeping with this hypothesis, augmenting synaptic DA concentrations by enhancing the synthesis by L-3-4-dihydroxyphenylalanine with carbidopa, or by decreasing its degradation by monoamine oxidase-B blockade with selegiline, led to marked decreases in ethanol preference and in the high voluntary consumption of ethanol in C57 mice. The selegiline-mediated decrease in ethanol preference and drinking in C57 mice could be blocked selectively by D1 and D2 DA receptor antagonists, which suggests that DA activity at D1 and D2 receptors plays an important role in this behavior. Indeed, the high preference for ethanol in C57 animals could be attenuated by direct DA receptor activation by either D1 or D2 agonists.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of school children at high risk for fragile X syndrome utilizing buccal cell FMR-1 testing

We describe a pilot project utilizing saliva to identify the FMR-1 mutation in high-risk special education students from four public school districts in Colorado. The program included presentations to special education teachers regarding fragile X syndrome, parental consent for testing, completion of a behavior checklist by the teachers, identification of special education students at high risk for fragile X syndrome, subsequent brief examination of face and hands, collection of a saliva sample by either Gatorade swish or brushing of the inside of the cheek, and analysis for the FMR-1 mutation by PCR. Equivocal samples were studied by direct DNA testing using Southern blot analysis, and abnormal results were confirmed by a blood analysis for the FMR-1 mutation. Mutant individuals received genetic counseling and medical and educational assessments to optimize treatment and intervention. This pilot project was met with enthusiasm by the schools. Of the first 439 students evaluated, 68% were male with an average age of 7.75 years; 13% were mentally retarded or autistic. Most students referred for the evaluation were learning disabled (51%) and/or had an Attention Deficit Hyperactivity Disorder (ADHD) (35%). The overall prevalence of the FMR-1 mutation was 5 of 439 or 1.1%. This relatively low yield is probably due to the high number of non-retarded but learning disabled students tested. Of the mentally retarded patients tested, 3.5% were positive for the FMR-1 mutation; however, of the non-retarded or learning disabled patients, only 0.79% were FMR-1 positive.(ABSTRACT TRUNCATED AT 250 WORDS)

Corticotropin-releasing factor is altered in brains of animals with high preference for ethanol

Ethanol administered to rats has been shown to stimulate the hypothalamic-pituitary-adrenal axis. The present study describes alterations in brain CRF neuronal systems that accompanied the voluntary high consumption of ethanol by Wistar rats presented with a free choice between 6% ethanol and tap water. Hypothalamic CRF concentrations (outside median eminence) were significantly increased in animals with a high preference for ethanol whereas concentrations of CRF in neurointermediate pituitary and medulla-pons were significantly decreased. No changes of CRF levels were evident in median eminence, frontal cortex, midbrain, thalamus, or cerebellum. Brain CRF concentrations in two strains of mice with genetically determined differential alcohol preference were measured. In ethanol-naive mice, there were documented differences in CRF concentrations, with an increase in frontal cortex levels, and a decrease in medulla-pons levels in the ethanol-preferring strain (C57BL/6J) compared to the nonpreferring strain (C3H/CRGL/2). Thus, certain brain CRF neuronal systems are preferentially affected by high ethanol consumption, and pre-existing differences in these systems may even contribute to the development of a high preference for ethanol.

31P spectroscopy in thrombolytic treatment of experimental cerebral infarct

Ischemic changes produced by autogenous clot embolization of intracranial arteries were monitored by continuous surface-coil 31P spectroscopy in 12 rabbits: six were used as controls and six were treated intravenously with tissue-type plasminogen activator. The animals were sacrificed and the brains were fixed with intravital stains. The results indicate that spectral changes are reversible only when thrombolysis therapy is started within 30 min after ischemic changes are detected. The improvement of the 31P spectrum correlated with postmortem changes.

Microbore HPLC/mass spectrometry for the analysis of peptide mixtures using a continuous flow interface

Microbore HPLC techniques have been combined with fast atom bombardment mass spectrometry to provide HPLC/MS capabilities for the analysis of mixtures of peptides and small proteins. The interface between the liquid chromatograph and mass spectrometer is a continuous flow direct insertion probe which contains a fused silica capillary that delivers the eluting solvent to the FAB source of the mass spectrometer at a rate of 5-10 microL/min. Data are presented for the analysis of several mixtures of peptides ranging in molecular weights from about 900 to 6000 daltons. In addition, the analysis of 100 pmol of a tryptic digest of whale myoglobin is shown where 16 of the possible 19 peptides were identified in the mass range m/z 2200-250. The advantages of this approach to HPLC/MS are a relatively high sensitivity because of the low flow rates and low background, and the ability to detect high molecular weight compounds.

Increase in the brain regional depolarization-dependent Ca2+ uptake in rats preferring ethanol

The depolarization-dependent Ca2+ uptake system has been suggested to be involved in the release of transmitter and synaptic facilitation. It can be employed as an effective probe to study neurotransmission. Although ethanol has been shown to inhibit or facilitate neurotransmission very little is known about the intrinsic activity of neurotransmission in ethanol-preferring rats. Using the depolarization-dependent Ca2+ uptake system, we demonstrated that synaptic neurotransmission is more active in animals with moderate and high preference for ethanol. Results suggest that there are intrinsic differences in the brain regional neurotransmission among rats showing different degrees of preference for ethanol.

High sensitivity mass spectrometric determination of peptides: direct analysis of aqueous solutions

The high sensitivity analysis of peptides by fast atom bombardment mass spectrometry has been achieved using a continuous flow probe for the introduction of samples contained in aqueous solutions. Small aliquots of sample (0.5-1 microliter) are injected into a solvent flow containing water/glycerol (8:2). For several peptide samples tested whose molecular weights were between 1000 and 1500 daltons, molecular ions were selectively monitored at the 20 fmol level with a signal-to-chemical noise of about 4:1, and full scan data were obtained on about 5 pmol of sample. The increase in sensitivity observed using the continuous flow probe is shown to be a consequence of both the decrease in the chemical background noise and to the increase in ion yields obtained from the bombardment of aqueous sample solutions.

Chronic ethanol inhibits rat hippocampal "stimulus-secretion" coupling mechanism for 5-hydroxytryptamine in vitro

Effects of ethanol on serotonergic neurotransmission were investigated in crude mitochondrial fraction (P2 fraction) from rat brain hippocampus and hypothalamus. The [14C]5-HT preloaded P2 fraction was exposed to 45 mM KCl to induce 5-hydroxytryptamine release in vitro. Ethanol in vitro did not produce any significant inhibition of [14C]5-HT release until its concentration was greater than 100 mM. The K+-evoked 45Ca uptake of hippocampal P2 fraction was unaffected by 100 mM. However, 200 mM ethanol inhibited approximately 63% of K+-evoked 45Ca uptake. Chronic ethanol (10 g/kg/day) for 6 days inhibited [14C]5-HT release from hippocampus whereas it did not affect [14C]5-HT release from hypothalamus. Results indicate that chronic ethanol treatment may decrease serotonergic neurotransmission in selective brain regions. The reduction in 5-hydroxytryptamine release was the result of inhibition in "stimulus-secretion" coupling mechanism.

Peptide sequence analysis using exopeptidases with molecular analysis of the truncated polypeptides by mass spectrometry

Fast atom bombardment mass spectrometry is used for the analysis of the series of molecular products formed by the cleavage of polypeptide substrates with the exopeptidases carboxypeptidase Y and leucine aminopeptidase. By following the polypeptide molecular species rather than the released residues, sequence information is obtained regardless of the relative rates of cleavage of peptide bonds. In addition, unambiguous assignments of sequence can be made in the presence of multiple identical residues. The lower level of sensitivity for the analysis is in the picomole range. When carboxypeptidase Y is used, the method provides a specific and sensitive method for the sequencing of polypeptides from the C-terminus.

Amitriptyline and ethanol: pharmacokinetic and pharmacodynamic interaction

Amitriptyline has clinically important interactions with ethanol. Five healthy volunteers received 25 mg of amitriptyline orally, preceded by one hour and followed for eight hours by oral ethanol (or juice), dosed to achieve and maintain blood ethanol concentrations of 800 mg/l. In the presence of ethanol, amitriptyline free plasma concentrations were increased by a logarithmic mean of 204%, 186% and 127% at 1.5, 2, and 2.5 h, respectively, and amitriptyline free AUC0-8h was increased by 48% +/- 13% (means +/- SEM) (t = 5.21, p less than 0.01). Nortriptyline total AUC0-8h was increased by 26.6% +/- 12% (means +/- SEM) (t = 2.21, p less than 0.09). At the time of peak amitriptyline plasma concentrations, mean postural sway was increased over baseline by 92% with, and 2% without ethanol; likewise, mean short term memory (word recall) was decreased over baseline by 71% with, and 37% without ethanol. Ethanol increases free amitriptyline plasma concentrations most dramatically during the period of drug absorption; this is due to a decrease in amitriptyline hepatic clearance, resulting in decreased first-pass extraction. Together with the pharmacodynamic interaction, the kinetic changes provide a rationale for the toxicity of this combination and its deleterious effects on psychomotor skills.

Variability in heparin effect on serum drug binding

Heparinized saline was given to seven men and one woman, aged 21 to 42 yr, after a 14-hr fasting period and 2 hr after breakfast; blood was collected in nonoheparinized tubes. Diazepam (D alpha) and warfarin (W alpha) free fractions were determined in serum by equilibrium dialysis to which radiolabeled drug was added. After 50 U heparin (Harris LO14) intravenously, the maximum effect on D alpha, W alpha, and free fatty acids (FFA) developed in 5 min and lasted 20 to 30 min. D alpha rose and W alpha fell (p < 0.01) at 5 min. Cumulative doses of heparin increased FFAs (F4,16 = 18.29, p < 0.0005). D alpha rises (r = 0.73, p < 0.001) and W alpha falls (r = -0.74, p < 0.001) correlated with changes in FFAs. D alpha rises and W alpha falls were greater postprandially than in the fasted state (p < 0.01). Five subjects were randomly assigned up to 400 U intravenously of each of two different heparin lots (Harris LO14, and Organon LA39.) The FFA rises (reflecting heparin lipolytic activity, F1,32 = 179.62, p < 0.0005), D alpha rises (F1,32 = 34.22, p < 0.0005), and the W alpha falls (F1,32 = 33.20, p < 0.0005) by heparin Harris LO14 were greater than those by heparin Organon LA39. Although small doses of heparin, such as those in heparin locks, can affect drug binding, the extent and variability of the effect depends on the biologic activity of the heparin, and varies with manufacturer and lot, exact time of sampling, and eating.