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M Pfeffer

Publications and source records attributed to M Pfeffer.

At least 19 recordsLinked to original sources
PubMed1999

[Persistent arthralgias in Ross-River-Virus disease after travel to the South Pacific].

HISTORY AND CLINICAL FINDINGS: A 57-year-old patient presented with malaise and severe persistent arthralgia of the left shoulder. He reported an acute illness with fever, generalized myalgia and arthralgias of the large joints which had started one month earlier during his flight back to Germany after a two weeks trip to the South Pacific. Physical examination showed extensive pain on palpation of the glenohumeral and acromioclavicular joints with impairment of active and passive mobility. Investigation of the cervical spine was normal. INVESTIGATIONS: Apart from elevated C-reactive protein and erythrocyte sedimentation rate levels, routine laboratory investigations were normal including negative immunodiagnostic tests for autoantibodies and various global infections that may be associated with arthritis. Immunofluorescence tests showed significant levels of specific IgM- and IgG-antibodies against Ross River virus (RRV) but not against other arboviruses endemic in the South Pacific and Australia (Dengue, West Nile, Chikungunya, Sindbis, Barmah Forest). This was confirmed by a positive RRV neutralisation test. Attempts at virus isolation and detection of viral RNA by PCR were not successful. TREATMENT AND COURSE: Symptomatic treatment with high doses of diclofenac quickly led to pain relief, and arthralgias receded within 10 days after begin of treatment. However, several bouts of arthralgia of the left shoulder and left knee occurred during a period of 4 months. CONCLUSIONS: Because of the current epidemiological situation in the South Pacific and Australia, infections by arboviruses like RRV should be considered in travellers returning from these areas with severe and persistent arthralgia of unknown origin, even in the absence of fever and other symptoms of acute infection.

Alphavirus Infections↗
PubMed1999

Transcription factors in neuroendocrine regulation: rhythmic changes in pCREB and ICER levels frame melatonin synthesis.

Neurotransmitter-driven activation of transcription factors is important for control of neuronal and neuroendocrine functions. We show with an in vivo approach that the norepinephrine cAMP-dependent rhythmic hormone production in rat pineal gland is accompanied by a temporally regulated switch in the ratio of a transcriptional activator, phosphorylated cAMP-responsive element-binding protein (pCREB), and a transcriptional inhibitor, inducible cAMP early repressor (ICER). pCREB accumulates endogenously at the beginning of the dark period and declines during the second half of the night. Concomitant with this decline, the amount of ICER rises. The changing ratio between pCREB and ICER shapes the in vivo dynamics in mRNA and, thus, protein levels of arylalkylamine-N-acetyltransferase, the rate-limiting enzyme of melatonin synthesis. Consequently, a silenced ICER expression in pinealocytes leads to a disinhibited arylalkylamine-N-acetyltransferase transcription and a primarily enhanced melatonin synthesis.

Animals↗
PubMed1999

Characterization of orthopoxviruses isolated from man and animals in Germany.

Fourteen orthopoxvirus strains isolated from humans, cats, a dog, a cow, and an elephant in Germany were characterized. All were classified as cowpox virus based on haemorrhagic lesions induced on the chorioallantoic membrane of chicken eggs and reactivity of a 160 kDa protein with anti-A-type inclusion protein hyperimmune serum in a Western blot. More detailed comparison of the isolates by restriction endonuclease mapping using HindIII and XhoI demonstrated a close relationship between all isolates and confirmed them as cowpox viruses. However, some minor differences between the isolates were detected which proved to be of epidemiological value. One group consisting of five closely related isolates contained a unique 4.0 kb HindIII fragment. In a Southern blot this fragment failed to hybridize with other cowpox virus isolates including the reference strain.

Amino Acid Sequence↗
PubMed1999

Sequencing of prototype viruses in the Venezuelan equine encephalitis antigenic complex.

The 5' nontranslated region (5'NTR) and nonstructural region nucleotide sequences of nine enzootic Venezuelan equine encephalitis (VEE) virus strains were determined, thus completing the genomic RNA sequences of all prototype strains. The full-length genomes, representing VEE virus antigenic subtypes I-VI, range in size from 11.3 to 11.5 kilobases, with 48-53% overall G+C contents. Size disparities result from subtype-related differences in the number and length of direct repeats in the C-terminal nonstructural protein 3 (nsP3) domain coding sequence and the 3'NTR, while G+C content disparities are attributable to strain-specific variations in base composition at the wobble position of the polyprotein codons. Highly-conserved protein components and one nonconserved protein domain constitute the VEE virus replicase polyproteins. Approximately 80% of deduced nsP1 and nsP4 amino acid residues are invariant, compared to less than 20% of C-terminal nsP3 domain residues. In two enzootic strains, C-terminal nsP3 domain sequences degenerate into little more than repetitive serine-rich blocks. Nonstructural region sequence information drawn from a cross-section of VEE virus subtypes clarifies features of alphavirus conserved sequence elements and proteinase recognition signals. As well, whole-genome comparative analysis supports the reclassification of VEE subtype-variety IF and subtype II viruses.

5' Untranslated Regions↗
PubMed1999

Candesartan in heart failure--assessment of reduction in mortality and morbidity (CHARM): rationale and design. Charm-Programme Investigators.

BACKGROUND: Chronic heart failure (CHF) is an increasing burden to health care. Pharmacological treatment with angiotensin-converting enzyme (ACE) inhibitors and beta blockers improve survival and reduce hospitalizations in patients with low left ventricular ejection fraction (LVEF). Despite these therapies, morbidity and mortality remains problematic. Furthermore, 30% to 50% of patients with CHF have a preserved LVEF. It is not known if treatments are of benefit in this group. DESIGN: Candesartan in Heart Failure-Assessment of Reduction in Mortality and Morbidity (CHARM) is a program designed to investigate the clinical usefulness of the long-acting angiotensin II type 1 receptor blocker, candesartan cilexetil, in a broad spectrum of patients with symptomatic heart failure. Patients with systolic dysfunction, tolerant or intolerant to an ACE-inhibitor, and patients with preserved systolic function are included. Specifically, the CHARM program consists of 3 independent, parallel, placebo-controlled studies in patients with (1) LVEF less than or equal to 40%, ACE-inhibitor treated (n = 2,300); (2) LVEF less than or equal to 40%, ACE-inhibitor intolerant (n = 1,700); (3) LVEF greater than 40%, not treated with ACE inhibitors (n = 2,500). The 3 studies will be combined to evaluate the effect of candesartan cilexetil on all-cause mortality in the broad spectrum of symptomatic heart failure. The primary objective in each trial is to evaluate the effects on the combined endpoint of cardiovascular mortality or CHF hospitalization. Other endpoints include the effects on myocardial infarction, all-cause hospitalization, and resource utilization. CHARM is intended to randomize 6,500 patients with symptomatic heart failure from 26 countries in Europe, the United States, Canada, South Africa, and Australia. The CHARM program started to enroll patients in March 1999. The follow-up period is a minimum of 2 years. The study is expected to end in the third quarter of 2002.

Adolescent↗
PubMed1999

Inducible cyclic AMP early repressor protein in rat pinealocytes: a highly sensitive natural reporter for regulated gene transcription.

Rhythmic activity of arylalkylamine N-acetyltransferase (AANAT) determines melatonin synthesis in rat pineal gland. The transcriptional regulation of AANAT involves the activating and inhibiting transcription factors of the cyclic AMP (cAMP)-signaling pathway, cAMP response element-binding protein and inducible cAMP early repressor (ICER), respectively. Activation of this pathway is centered around norepinephrine, stimulating beta(1)-adrenergic receptors, but various other transmitters can modulate melatonin biosynthesis. To compare the transcriptional impact of norepinephrine with that of other neurotransmitters on melatonin synthesis, we determined ICER protein levels in pinealocytes and, in parallel, hormone secretion. The dose-dependent inductions of ICER protein by norepinephrine, the beta(1)-adrenergic receptor agonist isoproterenol, vasoactive intestinal peptide, pituitary adenylate cyclase-activating polypeptide, and adenosine are correlated to regulatory dynamics in melatonin production. Importantly, ICER protein induction required lower ligand concentrations than the induction of melatonin biosynthesis. Although neuropeptide Y, glutamate, and vasopressin altered norepinephrine-stimulated hormone production without affecting ICER levels, the activation of voltage-gated cation channels increased ICER without affecting hormone synthesis. Sensitivity and versatility of ICER induction in pinealocytes make these neuroendocrine cells a valuable model system in which to study molecular interactions determining a regulated gene expression.

Acetylcholine↗
PubMed1999

Genetic evidence for the origins of Venezuelan equine encephalitis virus subtype IAB outbreaks.

Epizootics of Venezuelan equine encephalitis (VEE) involving subtype IAB viruses occurred sporadically in South, Central and North America from 1938 to 1973. Incompletely inactivated vaccines have long been suspected as a source of the later epizootics. We tested this hypothesis by sequencing the PE2 glycoprotein precursor (1,677 nucleotides) or 26S/nonstructural protein 4 (nsP4) genome regions (4,490 nucleotides) for isolates representing most major outbreaks. Two distinct IAB genotypes were identified: 1) 1940s Peruvian strains and 2) 1938-1973 isolates from South, Central, and North America. Nucleotide sequences of these two genotypes differed by 1.1%, while the latter group showed only 0.6% sequence diversity. Early VEE virus IAB strains that were used for inactivated vaccine preparation had sequences identical to those predicted by phylogenetic analyses to be ancestors of the 1960s-1970s outbreaks. These data support the hypothesis of a vaccine origin for many VEE outbreaks. However, continuous, cryptic circulation of IAB viruses cannot be ruled out as a source of epizootic emergence.

Amino Acid Sequence↗
PubMed1999

[Cowpox viruses in Germany: an analysis of 5 cases in 1998].

Five case reports on cowpox virus infections in cats, humans, and for the first time in a horse are presented. It becomes obvious that in most cases the diagnosis cowpox is suspected rather late, although fast and reliable diagnostic tools such as pathohistological examination and polymerase chain reaction are available. The threat of a zoonotic transmission mainly through cats is gaining importance. Although wild rodents have been claimed to be the reservoir and source for cowpox viruses in cats, very little is known about the epidemiology of cowpox virus. Based on the different genome organizations found in the German isolates, we conclude that various subtypes of cowpox virus are circulating in Germany at one time.

Animals↗
PubMed1998

Ontogeny of a diurnal rhythm in arylalkylamine-N-acetyltransferase mRNA in rat pineal gland.

Melatonin synthesis in the pineal gland of adult rats is linked to cAMP-dependent transcriptional and post-transcriptional regulatory mechanisms affecting its rate-limiting enzyme, the arylalkylamine-N-acetyltransferase (AA-NAT). During development of the pineal gland, neuronal control gains access to the earlier matured cAMP-signaling pathway to shape the day-night rhythm in AA-NAT enzymatic activity. By semiquantitative in situ hybridization we analyzed if the developmental onset of a rhythmic AA-NAT activity is correlated to a temporally parallel onset in AA-NAT transcription. We found that AA-NAT mRNA levels in rat pineal gland become rhythmic at postnatal day 5. Thus, AA-NAT gene transcription in rat pineal gland starts to show day-night differences shortly prior to the appearance of a rhythmic AA-NAT activity.

Animals↗
PubMed1998

The alphavirus 3'-nontranslated region: size heterogeneity and arrangement of repeated sequence elements.

The 3'-nontranslated region (NTR) of representative strains of all known alphavirus species was amplified by reverse transcription-polymerase chain reaction. For 23 of them, the 3'-NTR sequence was determined. Together with previously published data, this allowed an analysis of the 3'-NTR of the viruses in the genus Alphavirus. The length of the 3'-NTRs varied from 77 nt for Pixuna virus to 609 nt for Bebaru virus. The 19-nt conserved sequence element directly adjacent to the poly(A) tract was found in all viruses, supporting the hypothesis that this region is a cis-acting sequence element during viral replication and essential for virus growth in vitro. Within the 3'-NTR of all alphaviruses, repeated sequence elements of various numbers and lengths were found. Their composition was very consistent in both the Venezuelan equine encephalitis (VEE) and the Sindbis-like viruses, although their number was constant only within the latter group. For the VEE viruses, our data suggested that insertion events rather than deletions from an ancestor with a long 3'-NTR created the various number of repeated sequence elements. Among the remaining viruses, both the number and the composition of repeated sequence elements varied remarkedly.

Alphavirus↗
PubMed1998

Two-year time course and significance of neurohumoral activation in the Survival and Ventricular Enlargement (SAVE) Study.

AIMS: To describe the temporal evolution of neurohumoral activation in survivors of myocardial infarction with left ventricular dysfunction who are initially asymptomatic and to relate this to prognosis. METHODS AND RESULTS: Patients in the neurohumoral substudy (n = 534) of the Survival and Ventricular Enlargement (SAVE) study had their neurohormones measured at baseline, 3, 12 and 24 months post-infarction, were followed 38 +/- 7 months and had these values related to prognosis. All patients had a left ventricular ejection fraction < or = 40% early post-infarction. Atrial natriuretic peptide, aldosterone, norepinephrine and plasma renin activity decreased progressively over time. Patients with events had a persistent increase in these neurohormones with those dying within the first 24 months of follow-up having the greatest increase. Treatment with captopril affected only plasma renin activity (increase) and aldosterone (decrease). For patients who remained asymptomatic for the first 3 months post-infarction (n = 471), by multivariate analyses (all neurohormones together with non-neurohumoral risk factors), 3-month plasma atrial natriuretic peptide and aldosterone were the most closely related to the development of severe heart failure or to the combined end-points (cardiovascular death, myocardial infarction, or severe heart failure). No neurohormone was related to recurrent myocardial infarction or to cardiovascular mortality. When the last neurohormone measured prior to an event was considered along with non-neurohumoral risk factors (adjusted univariate), atrial natriuretic peptide, aldosterone, norepinephrine and epinephrine were associated with prognosis indicating that a time-dependent analysis identified a closer relationship between neurohormones and events than that identified by 3-month values. However, by multivariate analyses atrial natriuretic peptide was the only neurohormone associated with an event, being associated with the development of severe heart failure (P < 0.001) and the combined end-points (P = 0.022). However, when neurohormones were considered as binary variables, activated or non-activated (defined as > 1.96 SD above the mean of age-matched controls), an association between activation of norepinephrine prior to recurrent myocardial infarction (P < 0.001) and combined end-points (P < 0.01) and between activation of aldosterone and severe heart failure (P < 0.05) was identified. CONCLUSIONS: Neurohumoral activation decreases progressively post-infarction, but only in patients with a good prognosis. In patients with a left ventricular ejection fraction < or = 40% and asymptomatic post-infarction plasma atrial natriuretic peptide at 3 months, aldosterone levels appeared to be the neurohormones most closely associated with prognosis. Increased levels of atrial natriuretic peptide, aldosterone and norepinephrine appear to be temporally most closely associated with events.

Aldosterone↗
PubMed1998

Rhythmic variation in beta1-adrenergic receptor mRNA levels in the rat pineal gland: circadian and developmental regulation.

In the rat pineal gland noradrenaline is released in large quantities from sympathetic nerve endings at the onset of darkness, thereby driving rhythmic melatonin synthesis with elevated levels at night-time. Upon release, noradrenaline interacts with postsynaptic beta1-adrenergic receptors to activate the cyclic AMP signalling pathway. Well characterized third messengers of this signalling cascade affect cyclic AMP-inducible genes that are crucially involved in initiation, maintenance and termination of hormone production. Among these third messengers are CREB (cyclic AMP responsive element binding protein) as an activating and ICER (inducible cyclic AMP early repressor) as an inhibitory transcription factor. Because a cyclic AMP-inducible promoter element is present on the beta1-adrenergic receptor gene, the expression of the receptor itself may be under control of the cyclic AMP-signalling pathway. By in situ hybridization, Northern blot analysis and RT-PCR we demonstrate a day/night rhythm in beta1-adrenergic receptor mRNA in the rat pineal gland with elevated levels during the dark period. As this rhythm persists, under constant darkness but is abolished upon removal of the sympathetic innervation, it is truly circadian. A marked day/night difference in the levels of beta1-adrenergic receptor mRNA becomes evident only after postnatal day 10, coinciding with the appearance of a functional cyclic AMP signalling pathway in the rat pineal gland. Furthermore, targeting ICER expression by transfection of pinealocytes with an antisense ICER construct, clearly indicates that the levels of the beta1-adrenergic receptor mRNA are regulated by the cyclic AMP-signalling pathway in a feedback mechanism.

Animals↗
PubMed1998

Nucleotide sequences of the 26S mRNAs of the viruses defining the Venezuelan equine encephalitis antigenic complex.

Genetic relationships among viruses defining the Venezuelan equine encephalitis (VEE) virus antigenic complex were determined by analyzing the 3'-terminal 561 nucleotides of the nonstructural protein 4 gene and the entire 26S RNA region of the genome. New sequence information is reported for VEE 78V-3531 (VEE subtype-variety IF), Mucambo (IIIA), Tonate (IIIB), 71D-1252 (IIIC), Pixuna (IV), Cabassou (V), and AG80-663 (VI) viruses. The results reported here and by previous investigators largely support the current classification scheme of these viruses, while clearly identifying Everglades (II) as a subtype I virus. A genetic relationship between 78V-3531 (IF) and AG80-663 (VI) viruses contradicted previous serologic results. Mutations near the amino terminus of the E2 envelope proteins of Pixuna and AG80-663 viruses probably account for the previously reported low reactivity of the protective monoclonal antibody 1A2B-10 with these two viruses. Variations in the distribution of potential glycosylation sites in the E2 glycoprotein are discussed.

Amino Acid Sequence↗
PubMed1997

Additive beneficial effects of beta-blockers to angiotensin-converting enzyme inhibitors in the Survival and Ventricular Enlargement (SAVE) Study. SAVE Investigators.

OBJECTIVES: This study assessed whether treatment with a beta-adrenergic blocking agent in addition to the use of the angiotensin-converting enzyme (ACE) inhibitor captopril decreases cardiovascular mortality and morbidity in patients with asymptomatic left ventricular dysfunction after myocardial infarction (MI) and whether the presence of neurohumoral activation at the time of hospital discharge predicts the effects of beta-blocker treatment in these patients. BACKGROUND: Both beta-blockers and ACE inhibitors have been shown to have beneficial effects in patients with left ventricular dysfunction but no overt heart failure after MI. These patients often have persistent neurohumoral activation at the time of hospital discharge, and one would expect that patients with activation of the sympathetic nervous system derive the most benefit from treatment with beta-blockers. However, beta-blockers are underutilized in this high risk group of patients, and it is unknown whether their beneficial effects are additive to those of ACE inhibitors. METHODS: We performed a retrospective analysis of data from the Survival and Ventricular Enlargement (SAVE) study and its neurohumoral substudy. The relations between beta-blocker use at the time of randomization and neurohumoral activation and the subsequent development of cardiovascular events were analyzed by use of Cox proportional hazards models controlling for covariates. RESULTS: After adjustment for baseline imbalances, beta-blocker use was associated with a significant reduction in risk of cardiovascular death (30%, 95% confidence interval [CI] 12% to 44%) and development of heart failure (21%, 95% CI 3% to 36%), but the reduction in recurrent MI (11%, 95% CI 13% to 31%) was not significant. These reductions were independent of the use of captopril. Beta-blockers were not found to have a greater effect in patients with neurohumoral activation at the time of hospital discharge. CONCLUSIONS: The beneficial effects of beta-blocker use at the time of hospital discharge in patients with asymptomatic left ventricular dysfunction after MI appear to be additive to those of captopril and other interventions known to improve prognosis. Neurohumoral activation at the time of hospital discharge fails to identify those patients who will derive the greatest benefit from treatment with beta-blockers.

Adrenergic beta-Antagonists↗
PubMed1997

Specific detection of mousepox virus by polymerase chain reaction.

Polymerase chain reaction was applied to the rapid identification and detection of mousepox virus. This was accomplished by selection of primers targeting the A-type inclusion body protein gene. By investigating 20 strains belonging to five different species of the genus Orthopoxvirus, amplification was achieved only with the seven mousepox virus strains examined. The size of the resulting DNA fragment accounted for 116 base pairs and contained a recognition site for the restriction enzyme HindII, thus confirming its viral origin. Amplification of mousepox virus specific sequences was also possible from infected mouse lung tissue and serum.

Animals↗
PubMed1997

Genus-specific detection of alphaviruses by a semi-nested reverse transcription-polymerase chain reaction.

A reverse transcription-polymerase chain reaction (RT-PCR) was developed for the genus-specific detection of alphaviruses. Based on the available published sequences, degenerate primers were designed to ensure hybridization to a conserved region within the nonstructural protein 1 gene of all alphavirus species. The expected 434-basepair (bp) cDNA fragment was amplified from all 27 alphavirus species by using RNA extracted from 200 microl of infected cell culture supernatant. In addition, eight strains of Venezuelan equine encephalitis (VEE) virus and 10 strains of Sindbis virus were amplified. The viral origin of the amplicons was confirmed by restriction enzyme analysis and comparison with the expected cleavage pattern based on published sequence data. The PCR products of alphavirus species with thus far unknown nucleotide composition were sequenced. About 120 nucleotides downstream of the forward primer, a region showing sufficient homology for the design of another forward primer was found and used in a semi-nested PCR. The expected 310-bp semi-nested fragment was demonstrated for all viruses investigated. The sensitivity of the RT-PCR was about 1,200 plaque-forming units (PFU) for VEE virus reference strain Trinidad donkey. The detection limit after the semi-nested PCR was 1.2 PFU. The sensitivity was not hampered by the presence of human serum, thus making this test suitable for an application in viremic individuals. Chikungunya virus RNA was amplified from infected mouse brain tissue by the described RT-PCR assay. Our data suggest that the semi-nested RT-PCR may be applied as a highly sensitive alternative to virus isolation in the rapid screening and diagnosis of alphavirus infections, including post-mortem diagnosis. Phylogenetic analysis of the amplicon sequence data identified six genotypes within the Alphavirus genus.

Alphavirus↗
PubMed1996

Light-induced expression of transcription factor ICER (inducible cAMP early repressor) in rat suprachiasmatic nucleus is phase-restricted.

The mammalian hypothalamic suprachiasmatic nucleus (SCN) harbors an intrinsic circadian oscillator driving a variety of endogenous rhythms. SCN activity is entrained to environmental lighting conditions by photic information from the retina. Light-induced phase shifts involve cAMP and Ca2+ as second messengers and are linked to transcriptional and translational processes. Using in situ hybridization with a cDNA fragment of the cAMP responsive element modulator (CREM) isoform inducible cAMP early repressor (ICER) we demonstrate a light-induced upregulation of CREM mRNA in rat SCN during the second half of the night. Notably, ICER is the only member of the CREM family which is transcriptionally inducible. We suggest that a stimulus-induced upregulation of ICER expression can inhibit cAMP-inducible genes in rat SCN via its trans-repressing potency.

Animals↗