Permanent repigmentation of piebaldism by erbium:YAG laser and autologous cultured epidermis

BACKGROUND

Several surgical techniques have been proposed for the treatment of piebaldism. These procedures, however, are poorly suited for the treatment of large leucodermal lesions, can cause scars and require multiple donor sites. Recently, it has been reported that autologous cultured epidermis induces scarless repigmentation of large vitiligo lesions, using a single small donor site.

OBJECTIVES

To induce permanent repigmentation of large achromic lesions in patients suffering from piebaldism by means of autologous cultured epidermal grafts using a rapid, simple and non-invasive surgical procedure.

METHODS

Six patients with piebaldism were enrolled in this study. Achromic epidermis was removed by means of appropriately set erbium:YAG laser and autologous cultured epidermal grafts were applied on to the recipient bed. Melanocyte content was evaluated by 3,4-dihydroxyphenylalanine reaction. The percentage of repigmentation was calculated using a semiautomatic image analysis system.

RESULTS

Autologous cultured epidermis, bearing a controlled number of melanocytes, induced repigmentation of all piebald lesions. The mean percentage repigmentation was 95.45% (2791.5 cm2 repigmented/2924.2 cm2 transplanted).

CONCLUSIONS

Autologous cultured epidermal grafts induce permanent and complete repigmentation of piebald lesions, in the absence of scars. Erbium:YAG laser surgery is a rapid and precise tool for disepithelialization, hence allowing treatment of large piebald lesions during a single surgical operation.

Measurement of the electric form factor of the neutron at Q2=0.5 and 1.0 GeV2/c2

The electric form factor of the neutron was determined from measurements of the d-->(e-->,e'n)p reaction for quasielastic kinematics. Polarized electrons were scattered off a polarized deuterated ammonia (15ND3) target in which the deuteron polarization was perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle detector. We find G(n)(E)=0.0526+/-0.0033(stat)+/-0.0026(sys) and 0.0454+/-0.0054+/-0.0037 at Q(2)=0.5 and 1.0 (GeV/c)(2), respectively.

Vlasov model using kinetic phase point trajectories

A method of solution of the collisionless Vlasov equation by following fixed collisionless phase point ("particle") trajectories (characteristics) in phase space is presented. It solves the coupled Vlasov Maxwell system self-consistently and employs the Leapfrog-Trapezoidal scheme to solve for the characteristics explicitly. It then uses the bilinear finite element interpolation scheme in phase space and maps vital instantaneous phase point information (distribution function) to a fixed background phase space mesh while retaining it at the phase point. The scheme is an enhanced second order one in time and fourth order in space. The code is then used to model a thermal plasma as well as two stream instability using mobile electrons and fixed background ions: the scheme being a momentum conserving one by construction allows energy conservation without assignment of particle shape functions; Langmuir waves are obtained with very good agreement with the Bohm-Gross dispersion relation; the two stream results do not show any numerically induced oscillations attributed to the initial well-ordered velocity distributions. Retention of the characteristics also minimized diffusion. Extensive numerical stability analysis deriving Courant condition for the scheme as well as behavior of computational modes are done in Appendix A, as well as estimating the impact of numerical diffusion in Appendix B. Two to five dimensional versions in phase space exist.

Rapid detection of enterovirus RNA in cerebrospinal fluid specimens with a novel single-tube real-time reverse transcription-PCR assay

A single-tube real-time reverse transcription-PCR (RT-PCR) assay for enterovirus detection in cerebrospinal fluid (CSF) was developed based on a fluorogenic probe and primers directed to highly conserved sequences in the 5' untranslated region of the enterovirus genome. Quantitative detection of enterovirus genome was demonstrated in a linear range spanning at least 5 logs. Endpoint titration experiments revealed that the in-tube detection limit of the assay was 11.8 enterovirus genome equivalents (95% detection rate) corresponding in our current extraction protocol to 592 enterovirus genome equivalents per ml of CSF. Twenty CSF specimens not suspected of viral meningitis were all found to be negative, and no cross-reactivity with herpes simplex virus type 1 and type 2, varicella-zoster virus, rhinovirus type 53, and influenza viruses A and B was observed. Nineteen CSF specimens from 70 patients suspected of viral meningitis were determined to be positive by PCR (27.1%), whereas only 17 were found to be positive by viral culture (24.3%). The sensitivity of the assay was 100% and the specificity was 96.2% compared to viral culture. Data from the real-time RT-PCR assay were available within 4 h. Our data suggest that the novel real-time RT-PCR assay may offer a reliable but significantly faster alternative to viral culture. Owing to the elimination of postamplification detection steps, its conduct required considerably less hands-on time and was associated with a substantially reduced carryover risk compared to previously described PCR-based enterovirus detection assays.

Three-dimensional accuracy and interfractional reproducibility of patient fixation and positioning using a stereotactic head mask system

PURPOSE

Conformal radiotherapy in the head and neck region requires precise and reproducible patient setup. The definition of safety margins around the clinical target volume has to take into account uncertainties of fixation and positioning. Data are presented to quantify the involved uncertainties for the system used.

METHODS AND MATERIALS

Interfractional reproducibility of fixation and positioning of a target point in the brain was evaluated by biplanar films. 118 film pairs obtained at 52 fractions in 4 patients were analyzed. The setup was verified at the actual treatment table position by diagnostic X-ray units aligned to the isocenter and by a stereotactic X-ray localization technique. The stereotactic coordinates of the treated isocenter, of fiducials on the mask, and of implanted internal markers within the patient were measured to determine systematic and random errors. The data are corrected for uncertainty of the localization method.

RESULTS

Displacements in target point positioning were 0.35 +/- 0.41 mm, 1.22 +/- 0.25 mm, and -0.74 +/- 0.32 mm in the x, y, and z direction, respectively. The reproducibility of the fixation of the patient's head within the mask was 0.48 mm (x), 0.67 mm (y), and 0.72 mm (z). Rotational uncertainties around an axis parallel to the x, y, and z axis were 0.72 degrees, 0.43 degrees, and 0.70 degrees, respectively. A simulation, based on the acquired data, yields a typical radial overall uncertainty for positioning and fixation of 1.80 +/- 0.60 mm.

CONCLUSIONS

The applied setup technique showed to be highly reproducible. The data suggest that for the applied technique, a safety margin between clinical and planning target volume of 1-2 mm along one axis is sufficient for a target at the base of skull.

Different allele distribution of a regulatory MAOA gene promoter polymorphism in antisocial and anxious-depressive alcoholics

Heritable factors account for approximately 40-60% of the total variance of liability to alcohol dependence. The present study tested whether a novel functional polymorphism in the promotor region of the X-chromosomal monoamine oxidase A gene (MAOA) was related to antisocial and anxious-depressive traits in alcoholics. Due to the X-chromosomal localization of the MAOA gene, psychobiological traits were compared separately for both genders of 298 male and 66 female alcoholics. In males, 30 of 59 alcoholics with antisocial personality disorder carried the low-activity 3-repeat allele in contrast to only 7 of 31 anxious-depressive alcoholics (51% vs. 23%; p = 0.02). Likewise, female anxious-depressive alcoholics showed a trend towards a low frequency of genotypes with the 3 repeat allele compared to female alcoholics without these symptoms (29% vs. 53%; p = 0.09). Taken together, these findings suggest that the 3-repeat allele of the MAOA polymorphism contributes modestly to the dimension of overand underreactive behaviors as possible antecedents of alcoholism.

The sex-determining gene doublesex in the fly Megaselia scalaris: conserved structure and sex-specific splicing

The well-known sex-determining cascade of Drosophila melanogaster serves as a paradigm for the pathway to sexual development in insects. But the primary sex-determining signal and the subsequent step, Sex-lethal (Sxl), have been shown not to be functionally conserved in non-Drosophila flies. We isolated doublesex (dsx), which is a downstream step in the cascade, from the phorid fly Megaselia scalaris, which is a distant relative of D. melanogaster. Conserved properties, e.g., sex-specific splicing, structure of the female-specific 3' splice site, a splicing enhancer region with binding motifs for the TRA2/RBP1/TRA complex that activates female-specific splicing in Drosophila, and conserved domains for DNA-binding and oligomerization in the putative DSX protein, indicate functional conservation of dsx in M. scalaris. Hence, the dsx step of the sex-determining pathway appears to be conserved among flies and probably in an even wider group of insects, as the analysis of a published cDNA from the silkmoth indicates.

Environmental risks to Canadian children travelling overseas

Canadian children and youth travelling overseas face numerous environmental risks, including trauma, extreme temperatures, sun exposure, high altitudes, environmental pollution, and a variety of bites, stings and envenomations. Because skilled emergency response is limited or nonexistent in places where serious illness or injury is most likely to occur, avoiding or limiting these risks is imperative. Travel and paediatric health care providers must be able to identify environmental risks and to advise parents appropriately. Anticipating potential dangers and planning preventive strategies in advance can reduce both parental anxiety and the risk to children.

Loco-regional thrombolysis for deep vein thrombosis: fact or fiction? A study of hemostatic parameters

Loco-regional thrombolysis for deep-vein thrombosis (DVT) has been claimed to be equally effective and safe compared with systemic thrombolysis. It is not known whether a loco-regional thrombolytic effect exists and of what it might consist. To investigate this issue, we studied eight patients with DVT undergoing loco-regional thrombolysis with 20 mg alteplase infused over 4 h in a dorsal foot-vein of the affected leg, while the leg was kept tightly bandaged; alteplase infusions were repeated every 24 h, the number of therapy cycles (TC) was seven, and full-dose heparin was given. For coagulation analyses, 'loco-regional' blood samples were taken from a vein of the affected leg and 'systemic' samples were taken from an antecubital vein. After a median number of six TC, good partial reperfusion was achieved in 4/8 patients, moderate partial reperfusion in 2/8, major bleedings occurred in 2/8, and minor bleedings in 1/8 patients. During the first TC, recombinant tissue-type plasminogen activator (rtPA) activity and antigen, as well as FgDPs and d-dimers, were elevated significantly loco-regionally over systemic values, and a complete breakdown of plasmin-inhibitor activity occurred with only a slight systemic reduction; no other differences were found. During successive TC, differences in rtPA-activity and -antigen levels decreased, and no significant differences were found for all other parameters. Thus, a local fibrinolytic effect was demonstrable during loco-regional thrombolysis for DVT; the magnitude of this effect diminished during successive TC, giving rise to the hypothesis that the fibrinolytic efficacy may be decreased due to growing, antifibrinolytic activity. The preserved, loco-regional plasmin-inhibitor activities during the later TC, in contrast to the complete breakdown during the first TC, suggest that part of the enhanced antifibrinolytic activity is due to loco-regionally increased plasmin-inhibitor activity. The ultimate goal of loco-regional thrombolysis, the induction of local fibrinolysis without systemic effects, has not, however, been achieved.

Evidence that the beta-catenin nuclear translocation assay allows for measuring presenilin 1 dysfunction

BACKGROUND

Mutations in the presenilin (PSEN) genes are responsible for the majority of early-onset Alzheimer disease (AD) cases. PSEN1 is a component of a high molecular weight, endoplasmic reticulum, membrane-bound protein complex, including beta-catenin. Pathogenic PSEN1 mutations were demonstrated to have an effect on beta-catenin and glycogen synthase kinase-3beta(GSK-3beta), two members of the wingless Wnt pathway. The nuclear translocation and the stability of beta-catenin, and the interaction between GSK3beta and PSEN1 were influenced.

MATERIALS AND METHODS

Stably transfected human embryonic kidney (HEK) 293 cells overexpressing wild-type (wt) and mutant (mt) PSEN1, treated with and without LiCl, were used to isolate cytoplasmic and nuclear fractions. By Western blot analysis, endogenous beta-catenin levels were examined. By analyzing cytosolic fractions of PSEN1, transfected and nontransfected HEK 293 cells, and total brain extracts of AD patients and controls, we evaluated the effect of PSEN1 overexpression on beta-catenin stability. Finally, we analyzed the effect of pathogenic PSEN1 mutations on the interaction between PSEN1 and GSK3beta by co-immunoprecipitation experiments.

RESULTS

We report reduced nuclear translocation of beta-catenin in cells stably expressing I143T, G384A, and T113-114ins PSEN1. The G384A PSEN1 mutation showed a similar pronounced effect on nuclear translocation of beta-catenin, as reported for processing of amyloid precursor protein (APP) into amyloid beta(Abeta). Overexpression of PSEN1 and the presence of pathogenic mutations in PSEN1 had no significant effect on the stability of beta-catenin. Nonspecific binding of overexpressed PSEN1 to endogenous GSK3beta was observed when GSK3beta was immunoprecipitated. Immunoprecipitation of PSEN1 in cells overexpressing PSEN1 and in native cells, however, did not result in co-immunoprecipitation of endogenous GSK3beta.

CONCLUSION

Our results further establish the nuclear translocation assay of beta-catenin as an adequate alternative for traditional Abeta measurement to evaluate the effect of PSEN1 mutations on biochemical processes. We detected no significant effect of overexpressed wt or mt PSEN1 on the stability of beta-catenin. Finally, co-immunoprecipitation between PSEN1 and GSK3beta was not observed in our experimental setup.

Mimicry of human IgE epitopes by anti-idiotypic antibodies

According to Jerne's network hypothesis, the binding site of an anti-idiotypic antibody also represents the internal image of an epitope present on a foreign, or even a self antigen. In recent years, antigen mimicry has been defined at the molecular level for some xeno-antigens. However, until now there has been no demonstration of structural mimicry between a human anti-idiotypic antibody and a self structure. To address this question, we used human IgE as the self structure and a well-defined anti-human IgE mAb (BSW17). We describe the isolation of two anti- idiotypic antibodies specific for the anti-IgE antibody BSW17 from a non-immune human Fab phage display library. Interestingly, these two anti-idiotypic antibodies mimic the same molecular surface region as a previously described IgE peptide mimotope isolated by panning on BSW17, but they cover a much larger epitope on the IgE molecule. Accordingly, immunisation of rabbits with the two anti-idiotypic antibodies induced high-affinity antibodies with the same characteristics as BSW17. Thus, our data demonstrate that it is possible to isolate anti-idiotypic antibodies derived from the human genome without the need for hyperimmunization, and confirm Jerne's hypothesis that both foreign antigens and self structures can be mimicked by our own immunoglobulins.

Sequence conservation and expression of the sex-lethal homologue in the fly Megaselia scalaris

Sex-lethal (Sxl) is Drosophila melanogaster's key regulating gene in the sex-determining cascade. Its homologue in Megaselia scalaris, the chromosome 3 gene Megsxl, codes for a protein with an overall similarity of 77% with the corresponding D. melanogaster sequence. Expression in M. scalaris, however, is very unlike that in D. melanogaster. Megsxl transcripts with a long ORF occur in both sexes. Differential splicing is conserved but not sex-specific. There are several splice variants, among them one is common to gonads and somatic tissues of all developmental stages investigated, one is specific for ovaries and embryos, and a third one is not found in ovaries. In the ovary, Megsxl is heavily transcribed in nurse cells and transported into eggs. These results suggest a non-sex-determining function during early embryogenesis; the presence of Megsxl RNA in testes and somatic tissues calls for other (or more) functions.

Transition to alcohol dependence: clinical and neurobiological considerations

The transition to alcohol dependence is supposed to occur during a critical period that begins with increased drinking and ends with a loss of control. This process may last about 3 to 4 years, and is modified by gender and accelerated by premorbid traits (e.g., novelty-seeking) and comorbid disorders (e.g., dissocial personality disorders according to ICD-10). Genetic disposition, environmental influences (e.g., stress), and sensitization by exposure are factors implicated in dependence that alter brain functions, some possibly in an irreversible way. Underlying neurobiological mechanisms that may have different time patterns are beginning to be characterized on a systemic, cellular, and molecular level. Repeated free choices of the rewarding compound seem to be necessary for the transition to dependence.

[Comparison of computer tomography and magnetic resonance tomography in the diagnosis of acute intracerebral hemorrhage]

BACKGROUND AND PURPOSE

Stroke symptoms are caused in 10 to 15% by intracerebral hemorrhage. From the clinical examination it is often impossible to differentiate intracerebral hemorrhage from cerebral ischemia. To exclude intracerebral hemorrhage as the cause of clinical symptoms a CT is usually performed. The aim of our study was a direct comparison of the sensitivity of Computed Tomography and MRI using different MR sequences for the detection of acute intracerebral hemorrhage.

METHODS

In 8 male Wistar rats intracerebral hemorrhage was induced by infusion of collagenase into the caudate nucleus. After 1hour the brains were subsequently imaged with CT and MRI using T2- and T1-weighted Spin Echo sequences, diffusion-weighted sequences, T2*-weighted gradient echo sequences and FLAIR-sequences. Visibility of the intracerebral hemorrhage was examined using a scoring system from 1 = not visible to 5 = excellent visible. Finally, the intracerebral hemorrhage was verified by histological staining.

RESULTS

In all animals, intracerebral hemorrhage was visible in T2*-weighted gradient echo and diffusion weighted MR images 1 h after infusion of collagenase. T2- and PD-weighted SE images were positive in 7/8 rats. T1-weighted images revealed signal changes in 5/8 rats, and FLAIR sequence was positive in 8/8 rats. In CT intracerebral hemorrhage was only visible in 3/8 rats. When measuring the increase of Hounsfield units within the suspected hemisphere we saw a mean increase of 7% compared to the normal hemisphere in 3/8 rats.

CONCLUSIONS

In this animal model, T2*-weighted magnetic resonance imaging proved to be the most sensitive imaging modality in the detection of acute intracerebral hemorrhage and is by far more sensitive than CT.

Evaluation of the Strep A OIA assay versus culture methods: ability to detect different quantities of group A Streptococcus

The Strep A OIA assay by Biostar (Boulder, Co., USA) is a unique optical immunoassay system for the rapid detection of Group A streptococcal carbohydrate. As part of a community-based pediatric cohort study of Group A Streptococcus (GAS) persistence following antibiotic therapy of pharyngitis, the performance of the Strep A OIA assay was compared with the amount of growth from standard throat swab culture methods. A total of 363 throat swabs taken over the course of the study was evaluated from 248 children between 2 and 18 years of age. Two culture methods were performed: an agar plate with the throat swab using Columbia agar base with 5% sheep blood incubated under an anaerobic environment for 48 h and Todd-Hewitt broth (THB) enhancement. The Strep A OIA was then performed. A total of 144 of 363 (39.7%) samples was positive for GAS by one or more of the laboratory tests across study visits: agar culture detected 132 of 144 (91.7%), THB culture detected 128 of 144 (88.9%), and the Strep A OIA assay detected 129 of 144 (89.6%). Complete agreement among all three laboratory tests was found for 333 of 363 (91.7%) of the samples. Agar culture results were comparable to THB cultures with a sensitivity of 96.9%, specificity of 96.6%, a positive predictive value of 93.9%, and a negative predictive value of 98.3%. Although the performance of the Strep A OIA assay had similar specificity (96.5%) and positive predictive value (93.8%) compared with the combined results of the two culture methods, the sensitivity (89.0%) and negative predictive value (93.6%) were lower. A significant difference (p < 0.001) was found in the ability of the Strep A OIA assay to detect agar culture-positive swabs that had a light growth (1+ or 2+) (63.0%) versus a moderate (3+) or heavy (4+) growth (98.1%) of GAS. Although the Strep A OIA assay allows GAS throat swab results to be reported an average of 24 h sooner than either of the cultures, the rapid assay was not as sensitive in detecting light growth GAS-positive cultures.

No influence of presenilin1 I143T and G384A mutations on endogenous tau phosphorylation in human and mouse neuroblastoma cells

Presenilin1 (PSEN1) 1143T and G384A mutations give rise to severe early-onset Alzheimer's disease in two extensively studied Belgian families. In the present study, we examined the effect of PSEN1 1143T and G384A mutations on tau phosphorylation in human SH-SY5Y and mouse Neuro-2a neuroblastoma cell lines that were transiently transfected with wild type (WT) or mutant PSEN1. With a phosphorylation independent antibody, no alteration in the electrophoretic mobility of tau was observed between wild type and mutant PSEN1 transfectants. Also, densitometric analysis of Tau1 immunoreactivity, characteristic of unphosphorylated tau, demonstrated no significant differences between WT and mutant PSEN1 transfectants. Our data suggest that in the cellular models we used, transient overexpression of 1143T and G384A mutant PSEN1 does not lead to increased tau phosphorylation.

Endotoxin adsorbent based on immobilized human serum albumin

Extracorporeal apheresis of endotoxins and pro-inflammatory cytokines is still a therapeutic option in the early hyper-inflammatory phase of gram-negative sepsis. There is therefore ongoing interest in adsorber materials suitable for that kind of clinical application. Here we describe lipopolysaccharide (LPS) and cytokine adsorption characteristics of a new adsorbent based on purified human serum albumin (HSA) covalently linked to macroporous polymer beads (iHSA). Multipoint attachment of HSA to acrylic beads via carboxyl groups of the protein resulted in an increased affinity to LPS. In adsorption experiments (adsorbent/ plasma ratio 1:3) a 70-80% reduction of limulus amoebocyte lysate (LAL) activity from 8.59+/-2.07 EU/ml (mean+/-SD) to 1.82+/-0.77 EU/ml (S. abortus equi; n=40) (p < 0.001) and from 115.13+/-53.76 EU/ml to 17.70+/-11.68 EU/ml (E. coli F583; n=6) (p < 0.01) was achieved. iHSA-purified plasma samples showed a decreased capability of inducing cytokine release from peripheral monocytes. Direct haemoperfusion of LPS pre-stimulated whole blood over iHSA resulted in decreased tumour necrosis factor alpha (TNFalpha) concentrations (30-40% reduction) whereas induced levels of interleukin (IL)-1beta and IL-6 were not affected. Depending on the means of immobilization, iHSA shows higher affinity for LPS than native albumin present in plasma. We demonstrated an efficient removal of LPS from plasma in vitro. Adsorption over immobilized HSA appears to be a simple and effective means of removing LPS and perhaps pro-inflammatory cytokines from the circulation.

Real-time imaging of the axonal transport of granules containing a tissue plasminogen activator/green fluorescent protein hybrid

A hybrid protein, tPA/GFP, consisting of rat tissue plasminogen activator (tPA) and green fluorescent protein (GFP) was expressed in PC12 cells and used to study the distribution, secretory behavior, and dynamics of secretory granules containing tPA in living cells with a neuronal phenotype. High-resolution images demonstrate that tPA/GFP has a growth cone-biased distribution in differentiated cells and that tPA/GFP is transported in granules of the regulated secretory pathway that colocalize with granules containing secretogranin II. Time-lapse images of secretion reveal that secretagogues induce substantial loss of cellular tPA/GFP fluorescence, most importantly from growth cones. Time-lapse images of the axonal transport of granules containing tPA/GFP reveal a surprising complexity to granule dynamics. Some granules undergo canonical fast axonal transport; others move somewhat more slowly, especially in highly fluorescent neurites. Most strikingly, granules traffic bidirectionally along neurites to an extent that depends on granule accumulation, and individual granules can reverse their direction of motion. The retrograde component of this bidirectional transport may help to maintain cellular homeostasis by transporting excess tPA/GFP back toward the cell body. The results presented here provide a novel view of the axonal transport of secretory granules. In addition, the results suggest that tPA is targeted for regulated secretion from growth cones of differentiated cells, strategically positioning tPA to degrade extracellular barriers or to activate other barrier-degrading proteases during axonal elongation.

Serotonin transporter gene variants in alcohol-dependent subjects with dissocial personality disorder

BACKGROUND

We tested the hypothesis that a functional biallelic repetitive element in the 5' regulatory region of the human serotonin transporter gene (SLC6A4) confers susceptibility to serotonin-related personality traits underlying alcohol dependence with dissocial behavior.

METHODS

The association study was focused on 64 alcohol-dependent subjects with a dissocial personality disorder (according to ICD-10) who were derived from 315 German alcohol-dependent subjects. The Tridimensional Personality Questionnaire (TPQ) was applied to assess personality dimensions in 101 alcohol-dependent men, including 39 dissocial alcoholics.

RESULTS

Our association analyses revealed a trend towards a higher frequency of the short (S) allele of the SLC6A4 polymorphism in dissocial alcoholics compared to 216 German controls (chi 2 = 2.81, df = 1, p = 0.094). Dissocial alcoholics carrying the S/S genotype exhibited significant lower scores of harm avoidance compared to those lacking it (U-test, p = 0.015). Significantly higher novelty seeking scores were obtained in dissocial alcoholics carrying the S allele relative to those lacking it (U-test, p = 0.021).

CONCLUSIONS

Our tentative association findings in dissocial alcoholics suggest that the S allele of the 5' regulatory SLC6A4 polymorphism confers susceptibility to a temperamental profile of high novelty seeking and low harm avoidance that has been postulated to underlie dissocial (type-2) alcoholism according to Cloninger's neurogenetic theory of personality.

Evaluation of structurally different carotenoids in Escherichia coli transformants as protectants against UV-B radiation

Escherichia coli cells transformed with several carotenogenic genes to mediate the formation of zeta-carotene, neurosporene, lycopene, beta-carotene, and zeaxanthin were exposed to UV-B radiation. Short-term kinetics revealed that endogenous levels of neurosporene and beta-carotene protected E. coli against irradiation with UV-B. Zeaxanthin protected against only the photosensitized UV-B treatment. All other carotenoids were ineffective.

Modification of alcohol withdrawal by the A9 allele of the dopamine transporter gene

OBJECTIVE

Determinants of individual vulnerability to alcohol withdrawal symptoms are largely unknown. Because of the substantial role of monoaminergic transporters in limiting time and space effects of synaptic neurotransmission, the dopamine transporter gene (DAT1; locus symbol: SLC6A3) was studied as a candidate gene possibly related to symptoms of uncomplicated alcohol withdrawal.

METHOD

In 48 chronically intoxicated alcoholics (diagnosed according to ICD-10), withdrawal symptoms were examined and the presence of a variable-number tandem repeat in the 3' untranslated region of the DAT1 gene was determined.

RESULTS

Withdrawal syndromes were more pronounced in the 22 patients carrying the nine-copy repeat than in the 26 patients without this variant. Multiple regression analysis revealed that 4% of the variance of withdrawal was explained by this genotype, whereas 16% was due to the amount of alcohol the patients reported having consumed in the month before detoxification.

CONCLUSIONS

The A9 allele of the dopamine transporter gene is associated with more severe effects of alcohol withdrawal, possibly because of modifications of the brain's capacity to compensate for long-term effects of ethanol on cerebral function.

Association analysis of a regulatory variation of the serotonin transporter gene with severe alcohol dependence

The present study tested the hypothesis that the short, low activity variant of a biallelic polymorphism in the 5' regulatory region of the human serotonin transporter (5-HTT) gene confers susceptibility to severe alcohol dependence marked by severe withdrawal symptoms. Applying a phenotype-genotype strategy, our population-based association analysis included 216 German controls and an extreme sample of 103 severely affected alcoholics who were selected from 315 German alcohol-dependent subjects by a history of alcohol withdrawal seizure or delirium. The frequency of the short allele (S) was significantly increased in the severely affected alcoholics, compared with that in the controls (X2 = 3.87, df = 1, nominal p = 0.049). The post-hoc exploration indicated that this allelic association resulted exclusively from a significant excess of the S/S genotype in the severely affected alcoholics (p = 0.035), suggesting a recessively acting effect. Consistently, we found a weak but significant correlation (p = 0.013) between the frequency of the S/S genotype and severity of withdrawal symptoms (WDS): no WDS [18.3%, odds ratio (OR) = 1.16], vegetative WDS only (21.8%, OR = 1.44), and severe WDS with either withdrawal seizure only or delirium only (25.0%, OR = 1.69), and both withdrawal seizure and delirium (30.8%, OR = 2.30). Further studies are required to test whether the tentative genotype-phenotype relationship occurred by chance or reflects a real genotypic association between a recessively modifying effect of the short variant of the functional 5-HTT promoter polymorphism and alcohol withdrawal vulnerability.