Thromboxane A2 is one of the cyclooxygenase products derived from

Thromboxane A2 is one of the cyclooxygenase products derived from arachidonic

acid, and acts on its cognate G protein-coupled receptor [thromboxane receptor (TP)]. We show here that TP in the striatum locally facilitates dopamine overflow. Intrastriatal injection of a TP agonist increased extracellular dopamine levels in the striatum as measured by in vivo microdialysis. TP stimulation also augmented electrically evoked dopamine overflow from striatal slices. Conversely, TP deficiency reduced dopamine overflow evoked by N-methyl-d-aspartic acid (NMDA) and acetylcholine in striatal slices. TP immunostaining showed that TP is enriched in vascular endothelial cells. Pharmacological blockade of nitric oxide (NO) synthesis and genetic deletion of endothelial NO synthase (eNOS) suppressed NMDA/acetylcholine-induced Dabrafenib cell line dopamine ITF2357 overflow. This involvement of NO was abolished in TP-deficient slices, suggesting a role for eNOS-derived NO synthesis in TP-mediated dopamine overflow. As a functional consequence of TP-mediated dopamine increase, a TP agonist suppressed GABAergic inhibitory postsynaptic currents in medium spiny neurons through a D2-like receptor-dependent mechanism. Finally, TP is involved in sucrose intake, a dopamine-dependent motivational behavior. These data suggest that TP stimulation in the striatum locally

facilitates dopamine overflow evoked by synaptic inputs via NO synthesis in endothelial cells. “
“Information processing in the vertebrate brain is thought to be mediated through distributed neural networks, but it is still unclear how sensory stimuli are encoded and detected by these networks, and what role synaptic inhibition CHIR-99021 ic50 plays in this process. Here we used a collision avoidance behavior in Xenopus tadpoles as a model for stimulus discrimination and recognition. We showed that the visual system of the tadpole is selective for behaviorally relevant looming stimuli, and that the detection of these

stimuli first occurs in the optic tectum. By comparing visually guided behavior, optic nerve recordings, excitatory and inhibitory synaptic currents, and the spike output of tectal neurons, we showed that collision detection in the tadpole relies on the emergent properties of distributed recurrent networks within the tectum. We found that synaptic inhibition was temporally correlated with excitation, and did not actively sculpt stimulus selectivity, but rather it regulated the amount of integration between direct inputs from the retina and recurrent inputs from the tectum. Both pharmacological suppression and enhancement of synaptic inhibition disrupted emergent selectivity for looming stimuli. Taken together these findings suggested that, by regulating the amount of network activity, inhibition plays a critical role in maintaining selective sensitivity to behaviorally-relevant visual stimuli.

Serum and synovial concentrations of galectin-3 were positively c

Serum and synovial concentrations of galectin-3 were positively correlated with total number of joints with active arthritis and with overall articular severity score. Selleck Autophagy inhibitor Patients with Larsen index and total radiographic score ≥ 1 had significant higher serum galectin-3 levels than patients with indices and scores < 1. Conclusions:  These results suggest that serum levels of galectin-3 are increased in active JIA children

and galectin-3 can be a new biomarker indicating JIA disease activity, severity and progression, although its increment is not disease-specific. “
“Low back pain is one of commonest problems prompting a visit to the family physician. Up to 5% of patients with chronic low back pain in the primary care setting are diagnosed as having spondyloarthritis, which includes the prototype disease ankylosing spondylitis. Making a diagnosis of ankylosing spondylitis is often delayed for years, leading to significant pain, impairment of quality of life, disability and productivity loss. A recent breakthrough in the treatment of spondyloarthritis Metformin manufacturer is the anti-tumor necrosis factor-alpha biologics, which lead to rapid relief of pain and inflammation,

and improvement in all clinical parameters of the disease. Patients with early spondyloarthritis often respond better than those with late established disease. With proper recognition of inflammatory back pain, and the use of magnetic resonance imaging, spondyloarthritis can now be diagnosed much earlier before features are evident on plain radiographs. Referral to the rheumatologist

based on onset of back pain (> 3 months) before the age of 45 years, and an inflammatory nature of the pain, or the presence of human leukocyte antigen-B27, or sacroiliitis by imaging, have been confirmed in multi-center international studies to be a pragmatic approach to enable early diagnosis of spondyloarthritis. This referral strategy has recently been adopted by the Hong Kong Society of Rheumatology for primary care physicians and non-rheumatology specialists. “
“To determine the prevalence of joint hypermobility (JH) among young Kuwaiti adults. This was a cross-sectional study of 390 randomly selected healthy undergraduate university students, aged 18–29 years Florfenicol from the Health Sciences Centre, Kuwait University, Safat, Kuwait. Beighton score at four peripheral sites bilaterally (knees, elbows, thumbs and fifth fingers) and forward flexion of the trunk were used to evaluate joint hypermobility. Any student who met four out of the nine criteria was considered hypermobile. Joint pain was documented in all subjects through personal interview. A total of 390 subjects (male : female ratio 1.0 : 0.9) were assessed. Of those, 87 (22.3%) were found to have JH: 60 (29.4%) males and 27 (14.5%) females, showing a significantly higher male predominance (P < 0.001). Beighton score was inversely correlated with age (ρ = −0.15, P = 0.003).

Multiplex PCR have also been shown to provide a low-cost alternat

Multiplex PCR have also been shown to provide a low-cost alternative to DNA probe

methods for rapid identification of MAC [17]. Biopsies from other normally sterile body sites can prove diagnostic. Stains of biopsy specimens from bone marrow, lymph node or liver may demonstrate acid-fast organisms or granulomata weeks before positive blood culture results are obtained [18,19]. Treatment regimens for DMAC. • Antimycobacterial treatment of DMAC requires combination therapy that should include a macrolide and ethambutol, with or without rifabutin (category Ib recommendation). Macrolide-containing regimens are associated with superior clinical outcomes in randomized clinical trials as compared to non-macrolide-containing regimens [20] (category Ib recommendation). Clarithromycin and azithromycin have both demonstrated clinical and microbiological activity in a number of studies; however, macrolide monotherapy is associated Selleckchem Mitomycin C with rapid emergence of resistance [21]. Clarithromycin has been studied more extensively than azithromycin and is associated with more rapid clearance of MAC from the blood [22,23]. However, azithromycin has fewer drug interactions and is better tolerated

[24]. The dose of clarithromycin should not exceed 500 mg bd as higher doses have been associated with excess mortality [25]. Emergence of macrolide resistance is associated with a return of clinical symptoms and/or increased bacterial

counts in some patients [21]. Therefore, addition of at least one further class is recommended. Ethambutol is the most commonly recommended second drug [25] and GBA3 its addition to combinations used for MAC treatment reduces the development of macrolide resistance [26,27]. Ethambutol does not interact with currently available antiretroviral agents. A third drug (usually rifabutin) may be included in the regimen. One randomized clinical trial demonstrated that the addition of rifabutin to the combination of clarithromycin and ethambutol improved survival and the chance of complete microbiological response during the study period, though not microbiological clearance at the primary end-point of 12 weeks or relapse rate, while another study showed it reduced emergence of drug resistance [28,29]. Rifabutin dosage should not exceed 300 mg/day (or 450 mg if given with efavirenz or 150 mg three times a week if given with ritonavir) as cases of uveitis have been reported with higher doses, especially when given with clarithromycin [30–32]. It should be noted that many of the benefits of rifabutin were described pre-HAART and the benefits may be more marginal if HAART is administered.

7% β-Gal activity was observed using 100 μM 2,2′-dipyridyl, an ir

7% β-Gal activity was observed using 100 μM 2,2′-dipyridyl, an iron chelator) compared with high-iron conditions Ku-0059436 supplier (50 μM FeCl3 and 50 μM haem, 34% and 26% β-Gal activity, respectively) (Fig. 4). The results suggested that repression of mbfA by IrrAt does not require iron or haem as a cofactor. To further identify amino acid residues that are important for the iron sensing of IrrAt in mediating the derepression of mbfA, the iron responsiveness of the mutant IrrAt proteins (pIRR38, pIRR45, pIRR65,

pIRR86, pIRR92, pIRR93, pIRR94, pIRR105, pIRR127, pIRRHHH and pIRRHHH86) in the iron regulation of mbfA-lacZ was compared with wild-type IrrAt (pIRR) (Fig. 4). A single mutation in IrrAt at H38, D86, H92, H93 or D105 led to a hyper-repressed phenotype in which the expression of mbfA-lacZ was low and was not derepressed in response to iron and haem (Fig. 4). These residues appeared to play a role in the iron responsiveness of IrrAt. Although single mutations at H45, H65 and H127 reduced the repressor activity of IrrAt, the mutant proteins still retained iron responsiveness (Fig. 4). In contrast, the H94 mutant protein showed a greater reduction in repressor activity, and its iron responsiveness was lost (Fig. 4). The results suggested that H45, H65, H94 and H127 may play a role in the DNA-binding selleck compound ability

of IrrAt. Moreover, H94 was involved in iron sensing by IrrAt. The iron responsiveness was also lost in the HHH mutant protein, which likely resulted from the mutation at H94 (Fig. 4). The HHH86 mutant protein showed a hyper-repressed phenotype (Fig. 4). In conclusion, site-directed mutagenesis analysis revealed that residues H45, H65, H94 and H127 and the HHH motif are important for the repressor function of IrrAt. Mutations at these key residues may cause changes in protein conformation, preventing the protein from functioning properly. Single mutations at H38, D86, H92, H93 and D105 led to a hyper-repressed phenotype

(Fig. 4), implying that these residues CYTH4 may be directly or indirectly involved in the iron or haem binding and the iron-responsive regulatory function of IrrAt. Interestingly, only mutation at D86 was able to restore the repressor function of IrrAt that lacked the HHH motif (Fig. 2b). Residue D86 of IrrAt is equivalent to E80 of FurPa (the structural zinc-binding site) and to E90 of FurHp (regulatory site S2) (Fig. 1). It is possible that the conformation of the HHH mutant protein may undergo further structural modifications due to the mutation of D86 such that the HHH86 mutant protein is readily able to interact with DNA and may lock the protein in its DNA-binding conformation, resulting in loss of iron responsiveness. Residue H94 of IrrAt is a part of the conserved HHH motif (Fig. 1), which is a domain involved in haem sensing and in the IrrBj and IrrRl regulatory switch through different mechanisms (Qi et al.

Registry Name: clinicaltrialsgov, Registration #: NCT00742469 H

Registry Name:, Registration #: NCT00742469. H. L. D. P. has consulted with, received honoraria for speaking, and has received research grants administered through his university from Salix Pharmaceutical Company; has research grants administered through his

university from Optimer Pharmaceuticals and IOMAI Corporation; has received an honorarium for consulting and/or speaking with McNeil Consumer Healthcare and Merck Vaccine Division. C. D. E. has received honoraria from Salix for speaking and consulting. Z. D. J. has consulted with, received honoraria for AZD1208 mw speaking, and has received research grants administered through her university from Saliux Pharmaceutical Company. W. P. F., A. S., and E. B. are employees of and hold stocks in Salix Pharmaceuticals,

learn more Inc. The other authors state they have no conflicts of interest to declare. “
“To investigate the impact of intermittent interleukin-2 (IL-2) plus combination antiretroviral therapy (cART) on HIV-1 entry co-receptor use. Primary HIV-1 isolates were obtained from 54 HIV-1-positive individuals at baseline and after 12 months using co-cultivation of peripheral blood mononuclear cells (PBMC) with activated PBMC of HIV-negative healthy donors. HIV-1 co-receptor use was determined on U87-CD4 cells. Fourteen out of the 21 (67%) IL-2-treated individuals harbouring a primary CCR5-dependent (R5) HIV-1 isolate at baseline confirmed an R5 virus

isolation after 12 months in contrast to 3 out of 7 (43%) of those receiving cART only. After 12 months, only 1 R5X4 HIV-1 isolate was obtained from 21 cART+IL-2-treated individuals infected with an R5 virus at entry (5%) vs. 2/7 (29%) patients receiving cART alone, as confirmed by a 5-year follow-up on some individuals. Intermittent IL-2 administration plus cART may prevent evolution towards CXCR4 usage in individuals infected with R5 HIV-1. Intermittent administration of recombinant interleukin-2 (IL-2) induces a stable increase in peripheral CD4 T cells [1,2], although not associated Adenosine triphosphate with long-term protective effects on HIV disease evolution [3–6]. As the evolution of HIV-1 co-receptor (CoR) use from CCR5 only (R5) to CXCR4 has been linked to a faster disease evolution independently of CD4 T cell counts and viremia levels [7–9] and IL-2 is known to upregulate the expression of CCR5 [10,11], we have investigated the potential impact of intermittent IL-2 therapy on HIV CoR use in HIV-positive individuals enrolled in a controlled trial of intermittent IL-2 administration plus combination antiretroviral therapy (cART) vs. cART alone. Peripheral blood mononuclear cells (PBMC) were obtained at baseline and after 12 months from 54/61 (88.5%) HIV-positive individuals enrolled in a controlled trial in which recombinant IL-2 plus cART vs. cART alone was tested [12].

1,2 Mortality rate is > 90% in untreated cases, with a 10-year su

1,2 Mortality rate is > 90% in untreated cases, with a 10-year survival check details rate of only 6–25%. Long-term medical

treatment can increase the 10-year survival rate to 80–83%.4,15 Our case shows that medical treatment of cerebral AE is still a challenge for physicians. It is often a progressive disease and the clinical outcome is poor despite years of high-dose anthelmintic treatment. The authors state they have no conflicts of interest to declare. “
“As those with HIV infection live longer, ‘non-AIDS’ condition associated with immunodeficiency and chronic inflammation are more common. We ask whether ‘non-HIV’ biomarkers improve differentiation of mortality risk among individuals initiating combination antiretroviral therapy (cART). Using Poisson models, we analysed data from the Veterans Aging Cohort Study (VACS) on HIV-infected veterans initiating cART between 1 January 1997 and 1 August 2002. Measurements included: HIV biomarkers

(CD4 cell count, HIV RNA and AIDS-defining conditions); ‘non-HIV’ biomarkers (haemoglobin, transaminases, platelets, creatinine, and hepatitis B and C serology); substance abuse or dependence (alcohol or drug); and age. Outcome was all cause mortality. We tested the discrimination (C statistics) of each biomarker group alone and in combination in development and validation data sets, over a range of survival intervals, and adjusting for missing data. Of veterans initiating cART, 9784 (72%) had complete data. Of these, 2566 died. Subjects were middle-aged (median age 45 years), mainly male (98%) and predominantly black (51%). HIV and ‘non-HIV’ markers were associated with each BMN-673 other (P<0.0001) and discriminated mortality (C statistics 0.68–0.73); when combined, discrimination improved (P<0.0001). Discrimination for the VACS Index was greater for shorter survival intervals [30-day C statistic 0.86, 95% confidence interval (CI) 0.80–0.91], but good for intervals of up to 8 years (C statistic 0.73, 95% CI 0.72–0.74). Results were robust to adjustment for missing data. When added to HIV biomarkers,

‘non-HIV’ biomarkers improve Tacrolimus (FK506) differentiation of mortality. When evaluated over similar intervals, the VACS Index discriminates as well as other established indices. After further validation, the VACS Index may provide a useful, integrated risk assessment for management and research. With the advent of combination antiretroviral therapy (cART), people with HIV infection are living longer [1–3] and experiencing fewer AIDS-defining events and more ‘non-AIDS’ events [4]. Further, the majority of deaths occurring among those on treatment are now classified as ‘non-AIDS’ (i.e. not attributable to one or more of the 26 AIDS-defining conditions identified by the Centers for Disease Control and Prevention) [5–8]. Until recently, most considered this the inevitable price of success – people are living long enough on cART to die of other causes.

One class of cells had an initial standing signal indicative of h

One class of cells had an initial standing signal indicative of high extracellular H+ adjacent to

the cell membrane; challenge with glutamate, kainate or high extracellular potassium induced an extracellular alkalinization. This alkalinization was reduced by the calcium channel blockers nifedipine and cobalt. A second class of cells displayed SAR245409 spontaneous oscillations in extracellular H+ that were abolished by cobalt, nifedipine and low extracellular calcium. A strong correlation between changes in intracellular calcium and extracellular proton flux was detected in experiments simultaneously monitoring intracellular calcium and extracellular H+. A third set of cells was characterized by a standing extracellular alkalinization which was turned into an acidic signal by cobalt. In this last set of cells, addition of glutamate or high extracellular potassium did not significantly alter the proton signal. Taken together, the response characteristics of all three sets of neurons are most parsimoniously explained by activation of a plasma membrane Ca2+ ATPase pump, with an extracellular alkalinization resulting from exchange of intracellular calcium for extracellular H+. These findings argue strongly against the hypothesis that H+ release from horizontal cells Wnt inhibitor mediates lateral

inhibition in the outer retina. “
“Tricyclic antidepressants (TCAs) have been used to treat melancholic depression, which has been associated

with elevated hypothalamic–pituitary–adrenocortical (HPA) axis activity, whereas patients suffering from atypical depression, which is often associated with decreased HPA axis activity, show preferential responsiveness to monoamine oxidase inhibitors (MAOIs). We previously reported drug-specific effects of the TCA imipramine and the MAOI phenelzine SSR128129E on HPA axis-relevant endpoints in mice that may explain differential antidepressant responses in melancholic vs. atypical depression. However, selective serotonin reuptake inhibitors (SSRIs) are reported to be effective in both melancholic and atypical depression. We therefore hypothesized that SSRIs would share HPA axis-related effects with either TCAs or MAOIs. To test this hypothesis, we measured HPA axis-relevant gene expression in male C57BL/6 mice treated for 5 weeks with 10 mg/kg/day fluoxetine. To control for potential fluoxetine-induced changes in glucocorticoid secretion, mice were adrenalectomized and given fixed levels of glucocorticoids. Fluoxetine decreased glucocorticoid receptor (GR) gene expression in the prefrontal cortex, amygdala, locus coeruleus and dorsal raphé nucleus, and increased locus coeruleus tyrosine hydroxylase and dorsal raphé nucleus tryptophan hydroxylase-2 (TPH2) gene expression.

Infants were randomly allocated at less than 48 hours of age to:

Infants were randomly allocated at less than 48 hours of age to: 6 weeks of zidovudine monotherapy; or 6 weeks of zidovudine with three doses of nevirapine in the first week of life; or 6 weeks of zidovudine, with nelfinavir and lamivudine for 2 weeks. Overall in this high-risk group the HIV transmission rate was 8.5%, and in multivariate analysis only ART arm and maternal viral load were significantly associated with transmission. For infants uninfected at birth, transmission was two-fold higher in the zidovudine-alone

arm compared to the multiple ART arms (P = 0.034). There was no significant difference in transmission rates between the two multiple ARV arms and neonatal neutropenia was significantly

higher in the three-drug arm. In a randomized African study, babies born to mothers presenting at delivery received single-dose nevirapine or single-dose nevirapine and 1 week of zidovudine. Of those HIV negative at learn more birth, 34 (7.7%) who received nevirapine plus zidovudine and 51 (12.1%) who received nevirapine alone were infected (P = 0.03): a protective efficacy of 36% for the dual combination [279]. However, in two other randomized African studies where the mothers received selleckchem short-course ART, for infants uninfected at birth there was no significant difference in transmission rate at 6 weeks for dual versus monotherapy short-course regimens to the infant: zidovudine plus lamivudine versus nevirapine [280]; or zidovudine plus nevirapine versus nevirapine [281]. PEP for the infant of an untreated mother should be given as soon as possible after delivery. There are no studies of time of initiation of combination PEP, but in a US cohort study a significantly reduced risk of transmission was only observed in infants commenced on zidovudine when this was started within 48 hours of birth [158]. For this reason, infant

Thalidomide PEP should only be started where a mother is found to be HIV positive after delivery if it is within 48–72 hours of birth. NSHPC data from the UK and Ireland 2001–2008 demonstrate how the clinical practice of combination PEP in neonates has increased over time [282]. In total, 99% of 8205 infants received any PEP, and for the 86% with data on type of PEP, 3% received dual and 11% triple. The use of triple PEP increased significantly over this period, from 43% to 71% for infants born to untreated women, and from 13% to 32% where mothers were viraemic despite cART. HIV infection status was known for 89% of infants with information on PEP; 14.7% of infants who received no PEP were infected (5 of 34, all born vaginally to untreated mothers), compared to 1% of those who received any PEP (72 of 7286). Among infants born vaginally to untreated mothers, those who received PEP were significantly less likely to be infected than those who did not (8.5% [4/47] vs. 45.5% [5/11], P = 0.002).

LCO developed the analysis plan and performed all the statisti

L.C.O. developed the analysis plan and performed all the statistical evaluations and models. B.G., R.I.M. and J.P. developed the instruments for data collection and the study database. J.S.M., J.S., B.C., O.G.M. and M.B.L. contributed to data collection and verification. W.H.B., L.C.O., M.H.L., A.L.R. and B.G. contributed to the process of writing the manuscript. J.S.M., J.S., M.B.L. and O.G.M. participated in the correction of the final version of the manuscript. “
“Chronic kidney

disease (CKD) is common in HIV-infected individuals, and is associated with mortality in both the HIV-infected and general populations. Urinary markers of tubular injury have been associated with future kidney disease risk, but associations with mortality are unknown. We evaluated the associations of urinary interleukin-18 (IL-18), liver fatty acid binding protein

(L-FABP), kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL) and the albumin-to-creatinine ratio (ACR) with 10-year, all-cause death in 908 HIV-infected women. Serum cystatin C was used to estimate the glomerular filtration rate (eGFRcys). There were 201 deaths during 9269 person-years of follow-up. After demographic adjustment, compared with the lowest tertile, the highest tertiles of IL-18 [hazard ratio (HR) 2.54; 95% confidence interval (CI) 1.75–3.68], KIM-1 (HR 2.04; 95% CI 1.44–2.89), NGAL (HR 1.50; 95% CI 1.05–2.14) and ACR (HR 1.63; 95% CI 1.13–2.36) were associated with Stem Cells inhibitor higher mortality. After multivariable adjustment including adjustment for eGFRcys, only the highest tertiles of IL-18 (HR 1.88; 95% CI 1.29–2.74) and ACR (HR 1.46; 95% CI 1.01–2.12) remained independently associated with mortality. Findings for KIM-1 were borderline (HR 1.41; 95% CI 0.99–2.02). We found a J-shaped association between L-FABP and mortality. Compared with persons in

the lowest tertile, the HR for the middle tertile of L-FABP was 0.67 (95% CI 0.46–0.98) after adjustment. Associations were stronger when IL-18, ACR and L-FABP were simultaneously included in models. Among HIV-infected Cell press women, some urinary markers of tubular injury are associated with mortality risk, independently of eGFRcys and ACR. These markers represent potential tools with which to identify early kidney injury in persons with HIV infection. “
“Improvements in neurocognitive (NC) function have been associated with commencing antiretroviral therapy in HIV-infected subjects. However, the dynamics of such improvements are poorly understood. We assessed changes in NC function via a validated computerized battery (CogState™, Melbourne, Victoria, Australia) at baseline and after 24 and 48 weeks in a subset of therapy-naïve neuro-asymptomatic HIV-infected subjects, randomized to commence three different antiretroviral regimens.

, 2011) Some of these factors are also produced by G217B (Holbro

, 2011). Some of these factors are also produced by G217B (Holbrook E.D., Youseff B.H., and Rappleye C.A., pers. commun.). Finally, only NAm1 strains produce an extracellular serine-protease activity (Zarnowski et al., 2007a). No studies Daporinad in vivo have been done to determine if any of these variations contribute to Histoplasma pathogenesis. The completion of genome sequences from multiple phylogenetic groups and the continued development and application of molecular genetic techniques are furthering our understanding of the pathogenic

mechanisms that underlie Histoplasma virulence. For two of the most studied strains, G186A and G217B, both conserved components (e.g., Cbp1, Sid1) and distinct factors (e.g., α-glucan, Yps3) shape the resultant pathogenesis (Table 1). Ensartinib in vivo The examples of AGS1 and YPS3 highlight the influence of dissimilar transcriptional regulation on variation between strains with highly similar genome sequences. Surprisingly few mechanistic studies have been performed with multiple

Histoplasma strains, making it difficult to extrapolate experimental results from one strain to the others. Based on the variation in the few virulence factors examined to date, additional aspects distinguishing Histoplasma strains are expected. Establishment of the relevance of such mechanistic differences to Histoplasma pathogenesis will require recognition of the dissimilarities between strains and performance of comparative studies using the molecular genetic tools now available. Research in the Rappleye lab is supported,

in part, by funding from the National Institutes of Health (research grant AI083335) and a T32 fellowship award AI654114 to J.E. “
“All diazotrophic filamentous cyanobacteria contain an uptake hydrogenase that is involved in the reoxidation of H2 produced during N2-fixation. In Nostoc punctiforme ATCC 29133, N2-fixation takes place in the microaerobic heterocysts, catalysed by a nitrogenase. Although the function of the uptake hydrogenase may be closely connected to that of nitrogenase, the localization in cyanobacteria has been under debate. Moreover, the subcellular localization new is not understood. To investigate the cellular and subcellular localization of the uptake hydrogenase in N. punctiforme, a reporter construct consisting of the green fluorescent protein (GFP) translationally fused to HupS, within the complete hupSL operon, was constructed and transferred into N. punctiforme on a self-replicative vector by electroporation. Expression of the complete HupS–GFP fusion protein was confirmed by Western blotting using GFP antibodies. The N. punctiforme culture expressing HupS–GFP was examined using laser scanning confocal microscopy, and fluorescence was exclusively detected in the heterocysts.