Comparison of the risk of hospital admission, need for ventilation, sepsis, pneumonitis and death among the recent monkeypox outbreak and historical outbreaks

BACKGROUND

The course of monkeypox can be severe. Our aim was to retrospectively compare the risk of hospital admission, the need for ventilation, sepsis, pneumonitis and death between the recent outbreak and historical outbreaks.

MATERIALS AND METHODS

Cases of monkeypox were retrieved from the TriNetX database and assigned to either cohort I (recent outbreak between May 1st and September 16th, 2022) and cohort II (historical outbreaks before May 1st, 2022). After matching for age distribution, statistical analysis was performed.

RESULTS

Of 640 patients with monkeypox 81 subjects per cohort remained after matching (mean age±standard deviation = 36.1±18.3 years). Within 56 days after diagnosis 10 patients per cohort were hospitalized (12.4%) and/or developed sepsis (12.4%). The risk of ventilation and pneumonitis were significantly lower among cohort I compared with cohort II (0 vs. 10 cases; risk difference = 12.4%; p = 0.001; Log-Rank test). No cases of death were recorded.

CONCLUSION

Even though monkeypox provides a risk of severe courses, the infection is self-limiting in most cases. Unlike past outbreaks, the risk of ventilation and pneumonitis may be relatively low among recent outbreaks.

Real-world evidence for beneficial effects of dipyrone in 4,278 patients with pulmonary hypertension - Analysis of the risk of ventilation, hospitalization, and agranulocytosis

INTRODUCTION

Dipyrone has been used as an analgesic for a century, but recently was proposed as a novel therapeutic strategy for the prevention and therapy of pulmonary hypertension (PH). The aim of this study was to analyze whether the risk for ventilation procedures and hospitalization was lower among patients with PH who used dipyrone compared to subjects who did not use dipyrone.

MATERIALS AND METHODS

Initially, patients with PH were retrieved from the TriNetX database, whereby subjects who used dipyrone were assigned to cohort I, and cohort II was formed by those individuals who did not use dipyrone. Both cohorts were matched for several variables. The outcomes were requirement for ventilation procedures and hospital admission, whereby the time window to record events was 5 years after diagnosis of PH. Subsequently, risk analysis was carried out, and risk ratio (RR) and odds ratio (OR) were calculated. In addition, the risk of agranulocytosis was determined for both cohorts.

RESULTS

Out of 741,875 individuals diagnosed with PH 4,282 and 737,593 patients were assigned to the cohorts I and II. After matching, each cohort accounted for 4,278 individuals. Among the cohorts I and II 10 and 187 individuals required ventilation procedures. The according risks of 0.2% vs. 4.4% were significantly different (p < 0.0001; Log-Rank test). RR and OR were 0.053 and 0.051. Within the cohorts I and II 10 and 1,195 subjects required hospital admission. The risks of hospitalization of 0,4% vs. 27.9% differed significantly (p < 0.0001). RR and OR were 0.016 and 0.012. Among the cohorts I and II 47 and 66 individuals were diagnosed with agranulocytosis, whereby no significance was found (p > 0.05).

CONCLUSIONS

The risk for ventilation measures and hospitalization among patients with PH was found to be significantly lower when dipyrone was used. Even though the underlying mechanisms remain unknown to date, they are supposedly mediated by an active metabolite of dipyrone. The obtained results appear to be promising for patients suffering from PH. Hence, the present study may encourage further research.

A retrospective case-control study for the comparison of 5-year survival rates: the role of adjuvant and neoadjuvant chemotherapy in craniofacial bone sarcoma in adults

Background

The impact of adjuvant or neoadjuvant chemotherapy in the treatment of craniofacial bone sarcomas has not been clarified. This study aimed to assess whether survival outcomes differed between patients who underwent adjuvant or neoadjuvant chemotherapy.

Methods

A retrospective search for adult patients diagnosed with malignant neoplasms of the craniofacial bones (International Classification of Diseases 10 codes C41.0-C41.1), within the past 20 years from the access date 28 April 2022, was conducted using the TriNetX network (TriNetX, Cambridge, MA, USA). Cohort I included patients who underwent adjuvant chemotherapy and cohort II included patients with neoadjuvant chemotherapy. A refined search for individuals that received common chemotherapeutic agents, such as methotrexate, doxorubicin, cisplatin, and/or ifosfamide, was conducted and patients were assigned to cohort A (adjuvant chemotherapy) and cohort B (neoadjuvant chemotherapy). Following matching for age and sex, Kaplan-Meier analysis was performed, and risk ratio, odds ratio (OR), and hazard ratio were calculated.

Results

Patients were assigned to two cohorts, with 181 patients each after matching. In cohorts I and II, 55 and 41 patients died, respectively. No significant differences were found between the two cohorts regarding the 5-year survival probability (I: 59.87% versus II: 68.45%; p = 0.076; log-rank test), or the risk of dying (I: 0.304 versus II: 0.227; risk difference: 0.077; p = 0.096). The risk analysis before matching for age and sex showed a significant survival benefit in cohort II (OR: 1.586; p = 0.0295; risk difference: 0.093). After a refined query to identify patients treated with methotrexate, doxorubicin, cisplatin, and/or ifosfamide, the two cohorts included 47 patients, respectively. In cohort A (adjuvant chemotherapy), 19 patients died, whereas 12 patients died in cohort B (neoadjuvant chemotherapy) within 5 years after diagnosis. Further analysis indicated a greater survival in cohort B, but the survival probability between the cohorts did not differ significantly (A: 43.55% versus B: 54.49%; p = 0.171).

Conclusion

The use of neoadjuvant chemotherapy may improve survival rates in patients with surgically treated craniofacial bone sarcomas. Due to the retrospective nature of this study, randomized controlled studies are required to derive treatment recommendations.

The risk of oral squamous cell carcinoma in patients with and without somatoform disorders including bruxism: A retrospective evaluation of 309,278 individuals

Background

The question arises if there is an association of psycho-emotional stress and chronic soft tissue injuries caused by bruxism somatoform disorders with oral squamous cell carcinoma (OSCC).

Methods

Patients with and without "somatoform disorders including psychogenic disturbances" (International Classification of Diseases [ICD]-10 code F45.8), and/or "unspecific behavioral syndromes" (F59), and/or "sleep related bruxism" (G47.63), and/or "other sleep disorders" (G47.8) were retrieved from the TriNetX network to gain cohort I. Cohort II was formed by patients without the aforementioned diagnoses, and by matching for age, gender, tobacco use, and alcohol abuse. After defining the primary outcome as "OSCC" (ICD-10 codes C00-C14), a Kaplan-Meier analysis was performed, and risk ratio (RR) and odds ratio (OR) were calculated.

Results

After matching, each cohort accounted for 154,639 patients (59.7% females; 40.3% males; mean current age (± standard deviation) = 43.4 ± 24.5 years). Among cohorts I and II, 907 and 763 patients, respectively, were diagnosed with OSCC within 5 years (risk of OSCC = 0.6% and 0.5%), whereby the risk difference was significant (p < 0.001; Log-Rank test). RR and OR were 1.19 (95% confidence interval (CI), lower = 1.08 and upper = 1.31) and 1.19 (95% CI, 1.08-1.31).

Conclusions

Psycho-emotional stress and/or chronic mucosal injuries may play a role in carcinogenesis. However, the results need to be interpreted cautiously due to limitations of the applied approach. It may thus far only be concluded that further research is necessary to investigate hypotheses regarding psychogenic carcinogenesis and tumor formation due to chronic tissue trauma.

Real-world evidence from over one-million COVID-19 vaccinations is consistent with reactivation of the varicella-zoster virus

BACKGROUND

Reactivation of the varicella-zoster virus (VZV), which causes herpes zoster (HZ, synonym: shingles) in humans, can be a rare adverse reaction to vaccines. Recently, reports of cases after COVID-19 vaccination have arisen.

OBJECTIVES

The aim of this study was to assess if the frequency of HZ is found to increase after COVID-19 vaccination in a large cohort, based on real-world data. As a hypothesis, the incidence of HZ was assumed to be significantly higher in subjects who received a COVID-19 vaccine (Cohort I) versus unvaccinated individuals (Cohort II).

METHODS

Initial cohorts of 1,095,086 vaccinated and 16,966,018 unvaccinated patients were retrieved from the TriNetX database, and were matched on age and gender in order to mitigate confounder bias.

RESULTS

After matching, each cohort accounted for 1,095,086 patients. For the vaccinated group (Cohort I), 2,204 subjects developed HZ within 60 days of COVID-19 vaccination, while among Cohort II, 1,223 patients were diagnosed with HZ within 60 days after having visited the clinic for any other reason (i.e., not vaccination). The risk of developing shingles was calculated as 0.20% and 0.11% for cohort I and cohort II, respectively. The difference was statistically highly significant (p < 0.0001; log-rank test). The risk ratio and odds ratio were 1.802 (95% confidence interval [CI] = 1.680; 1.932) and 1.804 (95% CI = 1.682; 1.934).

CONCLUSIONS

Consistent with the hypothesis, a higher incidence of HZ was statistically detectable post-COVID-19 vaccine. Accordingly, eruption of HZ may be a rare adverse drug reaction to COVID-19 vaccines. Even though the molecular basis of VZV reactivation remains murky, temporary compromising of VZV-specific T cell-mediated immunity may play a mechanistic role in post-vaccination pathogenesis of HZ. Note that VZV reactivation is a well-established phenomenon both with infections and with other vaccines (i.e., this adverse event is not COVID-specific).

Comparison of five-year survival rates among patients with oral squamous cell carcinoma with and without association with syphilis: a retrospective case-control study

BACKGROUND

Syphilis is an infectious disease that is at least discussed to be premalignant. This potential, combined with its general pathological impact, raises the question if syphilis increases mortality in oral cancer patients. The aim of the study was to assess if the five-year survival rates among patients suffering from oral squamous cell carcinoma (OSCC) with (cohort I) and without association with syphilis (cohort II) differ.

METHODS

Retrospective clinical data of patients diagnosed with OSCC (International Classification of Diseases [ICD]-10 codes C01-06) within the past 20 years from the access date September 25, 2021 were retrieved from the TriNetX network (TriNetX, Cambridge, Massachusetts, USA) to gain initial cohort 0. Subjects also diagnosed with syphilis (ICD-10 codes A51-53) were assigned to cohort I. Cohort II was comprised of the remaining individuals of cohort 0 by creating a group with the same number of patients as cohort I, and by matching for age and gender. Subsequently, Kaplan-Meier analysis and Cox proportional hazards regression were performed, and risk, odds and hazard ratios were calculated.

RESULTS

Of a total of 73,736 patients in cohort 0, 199 individuals were each assigned to cohort I and II. During the five-year period after tumor diagnosis, 39 and 30 patients in cohort I and II died. The five-year survival probabilities did not significantly differ between the cohorts (I vs. II = 74.19% vs. 75.01%; p = 0.52; Log-Rank test), nor the risk of dying (I vs. II = 19.6% vs. 15.08%; risk difference = 4.52%; p = 0.23). The calculated risk, odds and hazard ratios were 1.3 (95% confidence interval [CI] = 0.84; 2.00), 1.37 (95% CI = 0.81; 2.31) and 1.17 (95% CI = 0.73; 1.88), respectively.

CONCLUSIONS

The obtained results indicate that the survival rate of individuals with OSCC might not be negatively influenced if syphilis is present/associated. However, the results need to be interpreted cautiously due to limitations related to the retrospective approach, especially as data on the tumor staging were not accessible.

TRIAL REGISTRATION

Due to the retrospective nature of the study, no registration was necessary.

Onset of Oral Lichenoid Lesions and Oral Lichen Planus Following COVID-19 Vaccination: A Retrospective Analysis of about 300,000 Vaccinated Patients

Introduction: Onset of oral lichenoid lesions (OLL) or oral lichen planus (OLP) can be rare adverse reactions to vaccines. Recently, the first solitary cases were reported after COVID-19 vaccination. The aim of the present study was to assess if an increased frequency of OLL/OLP can be found after COVID-19 vaccination within a large real-world cohort. It was assumed that the incidence of OLL/OLP was significantly higher in subjects who received COVID-19 vaccine (cohort I) compared to individuals who were not vaccinated (cohort II). Patients and Methods: Initial cohorts of 274,481 vaccinated and 9,429,892 not vaccinated patients were retrieved from the TriNetX database (TriNetX, Cambridge, Massachusetts, USA), and matched for age, gender and the frequency of use of non-steroidal anti-inflammatory drugs, beta blockers, and angiotensin-converting enzyme inhibitors. Results: After matching each cohort, we accounted for 217,863 patients. Among cohort I, 146 individuals had developed OLL/OLP within 6 days after COVID-19 vaccination (88 and 58 subjects had received mRNA- and adenovirus vector-based vaccines), whereas in cohort II, 59 patients were newly diagnosed with OLL/OLP within 6 days after having visited the clinic for any other reason. The risk of developing OLL/OLP was calculated as 0.067% vs. 0.027%, for cohorts I and II, whereby the risk difference was highly significant (p < 0.001; log-rank test). RR and OR were 2.475 (95% CI = 1.829; 3.348) and 2.476 (95% CI = 1.830; 3.350), respectively. Discussion: The hypothesis was confirmed. Accordingly, the obtained results suggest that the onset of OLL/OLP is a rare adverse drug reaction to COVID-19 vaccines, especially to mRNA vaccines. Thus far, it remains unknown if specific components of the formulations cause a type IV hypersensitive reaction corresponding to OLL, or if the immune response post vaccination triggers a T cell-driven autoimmune reaction directed against the basal layer of keratinocytes of the oral mucosa in terms of OLP. Although OLL and OLP are both classified as premalignant lesions, spontaneous remission may be expected over time, at least in the case of OLL. Therefore, the presented findings should not place any limitation toward the use of COVID-19-vaccines in broad levels of the population.

Occasional paternal inheritance of the germline-restricted chromosome in songbirds

Songbirds have one special accessory chromosome, the so-called germline-restricted chromosome (GRC), which is only present in germline cells and absent from all somatic tissues. Earlier work on the zebra finch (Taeniopygia guttata castanotis) showed that the GRC is inherited only through the female line-like the mitochondria-and is eliminated from the sperm during spermatogenesis. Here, we show that the GRC has the potential to be paternally inherited. Confocal microscopy using GRC-specific fluorescent in situ hybridization probes indicated that a considerable fraction of sperm heads (1 to 19%) in zebra finch ejaculates still contained the GRC. In line with these cytogenetic data, sequencing of ejaculates revealed that individual males from two families differed strongly and consistently in the number of GRCs in their ejaculates. Examining a captive-bred male hybrid of the two zebra finch subspecies (T. g. guttata and T. g. castanotis) revealed that the mitochondria originated from a castanotis mother, whereas the GRC came from a guttata father. Moreover, analyzing GRC haplotypes across nine castanotis matrilines, estimated to have diverged for up to 250,000 y, showed surprisingly little variability among GRCs. This suggests that a single GRC haplotype has spread relatively recently across all examined matrilines. A few diagnostic GRC mutations that arose since this inferred spreading suggest that the GRC has continued to jump across matriline boundaries. Our findings raise the possibility that certain GRC haplotypes could selfishly spread through the population via occasional paternal transmission, thereby outcompeting other GRC haplotypes that were limited to strict maternal inheritance, even if this was partly detrimental to organismal fitness.

Factors influencing the presence of Candida dubliniensis and other non-albicans species in patients with oral lichen planus: a retrospective observational study

Objectives

The epidemiologic distribution of non-albicans species in the oral cavity of oral lichen planus (OLP) patients remains uncertain. Therefore, the aim of this study was to identify factors associated with the presence of C. dubliniensis and other non-albicans species. Furthermore, independent risk factors for Candida superinfection in OLP should be identified.

Material and methods

Epidemiologic data and microbiological findings from 268 symptomatic OLP patients who underwent continuous oral swab culture over a 5-year period (2015–2019) were retrospectively reviewed. Candida species identification and semi-quantification were obtained by culture on CHROMagar Candida, followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

Results

C. albicans was the most frequently isolated species (72.3%), followed by C. glabrata (7.3%), C. dubliniensis (5.8%), C. krusei and C. parapsilosis (both 2.6%). The presence of C. dubliniensis was significantly associated with tobacco smoking. Other non-albicans spp. were significantly more often detected in patients using removable dentures. Increasing age and the intake of psychotropic drugs were identified as independent risk factors of Candida superinfection in OLP.

Conclusion

In OLP patients, certain local and systemic factors increase the risk of carrying potentially drug-resistant Candida species and the development of Candida superinfection of OLP lesions.

Clinical relevance

Due to the frequent detection of non-albicans species in OLP, resistance or at least reduced sensitivity to azole antifungals should be expected, especially in smokers and patients using removable dentures. In the case of oral complaints, a superinfection with Candida should be considered, whereby older patients and patients taking psychotropic drugs have an increased risk for oral infection with Candida.

Highly Efficient Genome Modification of Cultured Primordial Germ Cells with Lentiviral Vectors to Generate Transgenic Songbirds

The ability to genetically manipulate organisms has led to significant insights into functional genomics in many species. In birds, manipulation of the genome is hindered by the inaccessibility of the one-cell embryo. During embryonic development, avian primordial germ cells (PGCs) migrate through the bloodstream and reach the gonadal anlage, where they develop into mature germ cells. Here, we explored the use of PGCs to produce transgenic offspring in the zebra finch, which is a major animal model for sexual brain differentiation, vocal learning, and vocal communication. Zebra finch PGCs (zfPGCs) obtained from embryonic blood significantly proliferated when cultured in an optimized culture medium and conserved the expression of germ and stem cell markers. Transduction of cultured zfPGCs with lentiviral vectors was highly efficient, leading to strong expression of the enhanced green fluorescent protein. Transduced zfPGCs were injected into the host embryo and transgenic songbirds were successfully generated.

Geographic patterns in seasonal changes of body mass, skull, and brain size of common shrews

Some small mammals exhibit Dehnel's Phenomenon, a drastic decrease in body mass, braincase, and brain size from summer to winter, followed by a regrowth in spring. This is accompanied by a re-organization of the brain and changes in other organs. The evolutionary link between these changes and seasonality remains unclear, although the intensity of change varies between locations as the phenomenon is thought to lead to energy savings during winter.Here we explored geographic variation of the intensity of Dehnel's Phenomenon in Sorex araneus. We compiled literature on seasonal changes in braincase size, brain, and body mass, supplemented by our own data from Poland, Germany, and Czech Republic.We analyzed the effect of geographic and climate variables on the intensity of change and patterns of brain re-organization.From summer to winter, the braincase height decreased by 13%, followed by 10% regrowth in spring. For body mass, the changes were -21%/+82%, respectively. Changes increased toward northeast. Several climate variables were correlated with these transformations, confirming a link of the intensity of the changes with environmental conditions. This relationship differed for the decrease versus regrowth, suggesting that they may have evolved under different selective pressures.We found no geographic trends explaining variability in the brain mass changes although they were similar (-21%/+10%) to those of the braincase size. Underlying patterns of change in brain organization in northeastern Poland were almost identical to the pattern observed in southern Germany. This indicates that local habitat characteristics may play a more important role in determining brain structure than broad scale geographic conditions.We discuss the techniques and criteria used for studying this phenomenon, as well as its potential presence in other taxa and the importance of distinguishing it from other kinds of seasonal variation.

Vocal tract anatomy of king penguins: morphological traits of two-voiced sound production

BACKGROUND

The astonishing variety of sounds that birds can produce has been the subject of many studies aiming to identify the underlying anatomical and physical mechanisms of sound production. An interesting feature of some bird vocalisations is the simultaneous production of two different frequencies. While most work has been focusing on songbirds, much less is known about dual-sound production in non-passerines, although their sound production organ, the syrinx, would technically allow many of them to produce "two voices". Here, we focus on the king penguin, a colonial seabird whose calls consist of two fundamental frequency bands and their respective harmonics. The calls are produced during courtship and for partner and offspring reunions and encode the birds' identity. We dissected, μCT-scanned and analysed the vocal tracts of six adult king penguins from Possession Island, Crozet Archipelago.

RESULTS

King penguins possess a bronchial type syrinx that, similarly to the songbird's tracheobronchial syrinx, has two sets of vibratory tissues, and thus two separate sound sources. Left and right medial labium differ consistently in diameter between 0.5 and 3.2%, with no laterality between left and right side. The trachea has a conical shape, increasing in diameter from caudal to cranial by 16%. About 80% of the king penguins' trachea is medially divided by a septum consisting of soft elastic tissue (septum trachealis medialis).

CONCLUSIONS

The king penguins' vocal tract appears to be mainly adapted to the life in a noisy colony of a species that relies on individual vocal recognition. The extent between the two voices encoding for individuality seems morphologically dictated by the length difference between left and right medial labium. The septum trachealis medialis might support this extent and could therefore be an important anatomical feature that aids in the individual recognition process.

Male age and its association with reproductive traits in captive and wild house sparrows

Evolutionary theory predicts that females seek extra‐pair fertilizations from high‐quality males. In socially monogamous bird species, it is often old males that are most successful in extra‐pair fertilizations. Adaptive models of female extra‐pair mate choice suggest that old males may produce offspring of higher genetic quality than young males because they have proven their survivability. However, old males are also more likely to show signs of reproductive senescence, such as reduced sperm quality. To better understand why old males account for a disproportionally large number of extra‐pair offspring and what the consequences of mating with old males are, we compared several sperm traits of both captive and wild house sparrows, Passer domesticus. Sperm morphological traits and cloacal protuberance volume (a proxy for sperm load) of old and young males did not differ substantially. However, old males delivered almost three times more sperm to the female's egg than young males. We discuss the possibility of a post‐copulatory advantage for old over young males and the consequences for females mated with old males.

Seasonal reversible size changes in the braincase and mass of common shrews are flexibly modified by environmental conditions

The growth of the vertebrate skull and brain is usually unidirectional and more or less stops when animals are adult. Red-toothed shrews break this rule. They seasonally shrink and regrow brain and skull size by 20% or more, presumably to save energy when conditions are harsh. The size change is anticipatory of environmental change and occurs in all individuals, but it is unknown whether its extent can be modulated by environmental conditions. We kept shrews under different conditions, monitored seasonal changes in skull size with series of X-rays, and compared them with free ranging animals. We found extensive differences in the pattern of skull size change between experimental groups. Skull size of shrews kept at constant temperature showed a steady decline, while the skull size changes of free ranging shrews and captive individuals exposed to natural temperature regimes were identical. In contrast, body mass never reached the spring values of free ranging shrews in either captive regime. The extent of this adaptive seasonal pattern can thus be flexibly adapted to current environmental conditions. Combining reversible size changes with such strong phenotypic plasticity may allow these small, non-hibernating predators with high metabolic rates to continue being successful in today's changing environments.

The Influence of Cold Atmospheric Plasma Irradiation on the Adhesive Bond Strength in Non-Demineralized and Demineralized Human Dentin: An In Vitro Study

Purpose:

While aiming at the use of Cold Atmospheric Plasmas (CAPs) in restorative dentistry, the present study intended to assess if plasma irradiation increases the Tensile Bond Strength (TBS) in non-demineralized and demineralized dentin.

Materials and Methods:

Forty-eight human dentin samples were assigned to three different treatment modalities: I: Plasma jet irradiation (CAP I); II: Dielectric barrier discharge plasma treatment (CAP II); and III: No plasma (control). In each group, half of the specimens had previously been demineralized. A fourth generation of adhesive and dental composite was applied to all of the samples. The testing of the TBS was performed after artificial aging.

Results:

In the non-demineralized dentin, the mean TBS values were significantly higher after using CAP II (16.95 MPa) than in the control samples (4.2 MPa; p = 0.001). Significantly higher TBS values were also obtained after irradiating the demineralized dentin with CAP I and CAP II (11.68 and 4.6 MPa) when compared to the control samples (0 MPa; p = 0.003 and 0.038). The differences between both of the plasma sources were only slightly significant (p = 0.05).

Conclusion:

CAPs can potentially enhance the adhesive/dentin interfacial bonding strength, whereby the underlying effects seem to depend on the type of plasma source and the degree of dentinal (de-) mineralization. In the non-demineralized dentin, after a complete caries excavation, dielectric barrier discharge devices might be favorable over the plasma jets, in order to improve the adhesive/dentin interfacial bonding. In contrast, the plasma jets could be more effective in the demineralized dentin after an incomplete caries excavation.

Profound reversible seasonal changes of individual skull size in a mammal

Postnatal size changes in most vertebrates are unidirectional and finite once the individual reaches full size [1]. In rare cases, changes of body length may occur in response to harsh environmental conditions. Such reactionary changes are distinct from seasonal, often anticipatory morphological changes, such as the reversible size change of some adult bird brains [2]. A unique pattern of profound anatomical change known as Dehnel's phenomenon has been described for the body, skull and brain size of red-toothed shrews and some mustelids [3-5]. The seasonal 20% decrease and 15% re-growth of the most common proxy, braincase height, were documented at population level from extracted skulls post-mortem. Quantifying intra-individual change had so far been methodologically prohibitive. Here, we followed the intra-individual change in skull size and body mass throughout the full cycle in wild recaptured shrews (Sorex araneus). Using X-ray images we showed that individuals decreased the size of their braincases in anticipation of winter by an average of 15.3%. Braincases then partially regrew in spring by 9.3%. Body mass decreased by 17.6% and then dramatically increased by 83.4% in spring. Thus, we demonstrate that the dramatic changes incurred by Dehnel's phenomenon occur in the individual's bone and other tissues.

Profound seasonal changes in brain size and architecture in the common shrew

The seasonal changes in brain size of some shrews represent the most drastic reversible transformation in the mammalian central nervous system known to date. Brain mass decreases 10-26% from summer to winter and regrows 9-16% in spring, but the underlying structural changes at the cellular level are not yet understood. Here, we describe the volumetric differences in brain structures between seasons and sexes of the common shrew (Sorex araneus) in detail, confirming that changes in different brain regions vary in the magnitude of change. Notably, shrews show a decrease in hypothalamus, thalamus, and hippocampal volume and later regrowth in spring, whereas neocortex and striatum volumes decrease in winter and do not recover in size. For some regions, males and females showed different patterns of seasonal change from each other. We also analyzed the underlying changes in neuron morphology. We observed a general decrease in soma size and total dendrite volume in the caudoputamen and anterior cingulate cortex. This neuronal retraction may partially explain the overall tissue shrinkage in winter. While not sufficient to explain the entire seasonal process, it represents a first step toward understanding the mechanisms beneath this remarkable phenomenon.

Effects of plasma jet, dielectric barrier discharge, photodynamic therapy and sodium hypochlorite on infected curved root canals

The aim of this investigation was to evaluate the effects of 2 different cold atmospheric plasma (CAP) sources, photodynamic therapy and sodium hypochlorite (NaOCl), on infected root canals. Therefore, 50 standardized curved human root canals were infected with Enterococcus faecalis and assigned to 5 groups-negative control (NC), plasma jet (CAP I), dielectric barrier discharge (CAP II), photodynamic therapy (PDT) and NaOCl + passive ultrasonic irrigation-for 30 s. Colony forming units (CFUs) were determined. NaOCl was significantly more effective at reducing CFUs than all test groups (P < .0001 [Mann-Whitney U test]) in both parts of the root canal. CFUs in PDT were significantly lower than those in CAP II (P = .015), and those in CAP I were lower than those in CAP II (P = .05). Among all other groups and in the apical parts, no significant differences were found (P > .05).

Cognitive skills of common shrews (Sorex araneus) vary with seasonal changes in skull size and brain mass

In a rare phenomenon, shrews and a few other species cope with seasonal environments by reducing and regrowing brain size, potentially at the cost of changes in cognitive abilities. Here, we confirm an extensive seasonal shrinkage (21.4%) and regrowth (17.0%) of brain mass in winter and spring, respectively, in the common shrew (Sorex araneus L.) in Southern Germany. In a spatial learning task experiment, individuals with reduced winter brain size covered larger distances to find food, compared with the relatively large-brained summer juveniles and regrown spring adults. By reducing their brain mass, these shrews may reduce their energetic demands, but at the cost of cognitive performance, implying a complex trade-off for coping with seasonally fluctuating resources. These results are relevant for our understanding of evolution and the dynamics of mammalian nervous systems in response to environmental changes.

Profound seasonal shrinking and regrowth of the ossified braincase in phylogenetically distant mammals with similar life histories

Ontogenetic changes in skull shape and size are ubiquitous in altricial vertebrates, but typically unidirectional and minimal in full-grown animals. Red-toothed shrews exhibit a rare exception, where the shape, mass and size of the skull, brain, and several major organs, show significant bidirectional seasonal changes. We now show a similar but male-biased shrinking (16%) and regrowth (8%) in the standardized braincase depth of least weasels (Mustela nivalis). Juvenile weasels also exhibit a growth overshoot, followed by a shrinkage period lasting until the end of their first winter. Only male weasels then regrow during their second summer. High-resolution CT scans suggest areas of the skull are affected differently during shrinking and regrowth in both species. This suggests multiple evolutionary drivers: while the shrinking likely facilitates survival during seasonal low resource availability in these high-metabolic mammals with year-round activity, the regrowth may be most strongly influenced by high investment into reproduction and territories, which is male-biased in the weasels. Our data provide evidence for convergent evolution of skull and thus brain shrinkage and regrowth, with important implications for understanding adaptations to changing environments and for applied research on the correlated changes in bone structure, brain size and the many other affected organs.

Premature exposure of dental implant cover screws. A retrospective evaluation of risk factors and influence on marginal peri-implant bone level changes

OBJECTIVES

The objectives of this study were to identify risk factors associated with the premature cover screw exposure (pCSE) at dental implants and to evaluate the influence of a pCSE on peri-implant marginal bone level (MBL) change compared to non-exposed implants.

MATERIALS AND METHODS

Retrospective data assessment from 165 patients (mean age = 54.0 ± 14.4 years) who received 395 submerged implants included demographic, health-related, and therapeutic variables which were analyzed for their respective impact. MBL change was detected at digital radiographs obtained from first- and second-stage surgeries.

RESULTS

pCSE were detected in 43 patients (26.1%) and 53 implants (13.4%). An increased frequency of exposure was significantly associated with (I) male gender (p = 0.012) at patient level and (II) the posterior region of the jaws (p = 0.005), implant systems with platform-matching cover screws, and a vertical distance of ≥0.5 mm between bone crest and the implant platform (both p < 0.001) at implant level. The decrease in mesial, distal, and total MBL differed significantly (mean total = 0.8 ± 0.7 vs. 0.3 ± 0.5; mean mesial = 0.8 ± 0.8 vs. 0.3 ± 0.6; mean distal = 0.8 ± 0.8 vs. 0.3 ± 0.6 mm; p < 0.001) between non-exposed and pCSE implants.

CONCLUSIONS

Male patients, implants with platform-matched cover screws, or when placed supracrestally or in posterior sites revealed significantly more pCSE, resulting in significantly decreased peri-implant MBL compared with non-exposed implants.

CLINICAL RELEVANCE

Patients with an enhanced risk of pCSE should follow frequent regular recalls during the healing period to enable for early diagnosis and intervention.

Drill-related root injury caused by intraoperative intermaxillary fixation: an analysis of 1067 screw applications

BACKGROUND/AIMS

Intermaxillary fixation is a standard procedure for the treatment of mandibular fractures or in orthognathic surgery. Predrilling for screws poses the risk of accidental tooth root injury, potentially leading to further pathological processes. Limited evidence about accidental tooth injury during intermaxillary fixation is available due to heterogenous study designs. The aim of this study was to evaluate the risk of root trauma using predrilled transgingival fixation screws and the clinical consequences for the affected teeth.

MATERIALS AND METHODS

In this retrospective study, the data of open reduction and internal fixation surgery files with intraoperative application of predrilled intermaxillary fixation screws were analysed. The postoperative radiographic images were evaluated for the occurrence of tooth root injury. Patients diagnosed with root injury were clinically followed up with respect to the dental health for the affected teeth.

RESULTS

A total of 133 radiologically diagnosed tooth root injuries were recorded (12.5% of screws). The median follow-up interval was 16 months (range: 3-77 months). The return rate was 49.5% for all patients. Of these, four of the injured teeth (3%) needed endodontic treatment. No toothache was reported, no tooth was lost, and no negative impact on periodontal health was clinically evident.

CONCLUSION

Intermaxillary fixation with predrilled transgingival screws is a safe way to manage mandibular fractures. The incidence of tooth root injury is not uncommon, but the adverse side effects are rare and the health of the affected teeth is mostly not compromised.

Outcomes of Endodontic Therapy Comparing Conventional Sodium Hypochlorite Irrigation with Passive Ultrasonic Irrigation Using Sodium Hypochlorite and Ethylenediaminetetraacetate. A Retrospective Analysis

The aim of the present study was to investigate the clinical outcomes of two different standardized endodontic irrigation protocols. It was assumed that the additional use of ethylenediaminetetraacetate (EDTA) and passive ultrasonic irrigation (PUI) would result in an increased rate of absence of symptoms and remission based on the periapical index (PAI) compared to passive irrigation using only sodium hypochlorite (NaOCl).

Data and radiographs from 199 teeth retrieved from the institutional endodontic database were analyzed retrospectively. In 106 teeth irrigation was performed using only NaOCl (protocol 1). Ninety-three teeth were irrigated using NaOCl and EDTA (protocol 2). Chlorhexidine (CHX) was additionally used in revision treatments in both groups. All irrigants in group 2 were activated by PUI.

Mean follow-up periods were: protocol 1 = 9.2 ± 4.4 and protocol 2 = 6.6 ± 2.5 months (p < 0.0001 (chi-square test). The frequencies of the PAI_masterpoint and PAI_follow-up scores did not differ significantly between teeth, which received either protocol 1 or 2 (p = 0.555 and 0.138). Statistical analysis revealed no significant association between treatment success (absence of clinical symptoms and PAI_follow-up = I or PAI_masterpoint > PAI_follow-up > I) and the applied protocol (success rates: protocol 1 = 72.6% vs. protocol 2 = 82.8%; p = 0.203). Furthermore, the frequency of extractions did not differ significantly between the two protocols (p = 0.102). No association was found between follow-up time and treatment success (p = 0.888).

The hypothesis was not confirmed. Even though the obtained success rate was higher after supplementing the irrigation protocol with EDTA and PUI, no significance was recorded. Hence, protocol 2 was not superior to protocol 1 regarding therapy success, at least within the limited follow-up period. It may be cautiously concluded that sufficient mechanical debridement combined with passive NaOCl irrigation results in comparably high success rates compared to EDTA and PUI.

Bactericidal efficacy of tissue tolerable plasma on microrough titanium dental implants: An in-vitro-study

Surface decontamination remains challenging in peri-implant infection therapy. To investigate the bactericidal efficacy of tissue tolerable plasma, S. mitis biofilms were created in vitro on 32 microrough titanium dental implants. Biofilm imaging was performed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The implants were either rinsed with 1% NaCl as negative control (C) or irradiated with a diode laser (DL) for 60 sec as positive control or plasma (TTP60, TTP120) for 60 or 120 sec. Subsequently, colony forming units (CFU) were counted. Post-treatment, implants were further examined using fluorescence microscopy (FM). Median CFU counts differed significantly between TTP60, TTP120 and C (2.19 and 2.2 vs. 3.29 log CFU/ml; p = 0.012 and 0.024). No significant difference was found between TTP60 and TTP120 (p = 0.958). Logarithmic reduction factors were (TTP60) 2.21, (TTP120) 1.93 and (DL) 0.59. Prior to treatment, CLSM and SEM detected adhering bacteria. Post-treatment FM recorded that the number of dead cells was higher using TTP compared to DL and C. In view of TTP's effectiveness, regardless of resistance patterns and absence of surface alteration, its use in peri-implant infection therapy is promising. The results encourage conducting clinical studies to investigate its impact on relevant parameters.

Adjuvant antifungal therapy using tissue tolerable plasma on oral mucosa and removable dentures in oral candidiasis patients: a randomised double-blinded split-mouth pilot study

Extended use of antimycotics in oral candidiasis therapy gives rise to problems related to fungal drug resistance. The aim of this pilot study was to investigate the efficacy of tissue tolerable plasma (TTP) in denture stomatitis patients. It was hypothesised that (I): erythema and (IIa): complaint remission would be accelerated and (IIb): colony forming unit (CFU) reduction would be improved. The halves of the upper jaws of eight patients were randomly assigned to control (nystatin, chlorhexidine and placebo treatment) and test sides (nystatin, chlorhexidine and TTP administered six times each 7 days). The patients and the investigators, who were different from the therapists, were both blinded. Compared to the control sides, the erythema surface was reduced significantly more extensively on the test sides between 2 and 6 weeks of antifungal therapy (P ≤ 0.05). Visual analogue scale values and the frequency of moderate or heavy growth of Candida post-treatment did not differ significantly between both sides (P > 0.05). The primary hypothesis was confirmed, which may be interpreted as an accelerated remission. As drug therapy is usually limited to the time in which signs of infection are present, TTP might help reducing antifungal use. Even though the secondary hypotheses were not confirmed, persistence of Candida might be only colonisation.

Bactericidal Efficacy of Cold Plasma at Different Depths of Infected Root Canals In Vitro

Objectives:

Cold plasma (CP) has been shown to be effective even against multiresistant microorganisms. As previous investigations on the effect of CP in root canals showed promising results, the aim of the present study was to analyze the bactericidal efficacy of CP in different depths of infected dentin.

Methods:

32 standardized root canals of human mandibular premolars were infected with Enterococcus faecalis and incubated for one week. Specimens were randomly selected for one of four disinfection methods: control (5mL NaCl), 5mL chlorhexidine (CHX), CP alone (CP), and a combination of 5mL CHX and cold plasma (CHX+CP). CHX was ultrasonically activated for 30s, while cold plasma was used for 60s in the root canals. Dentin samples at depths of 300, 500 and 800 µm were obtained and diluted serially. Colony forming units (CFUs) were counted on agar plates after 24h of incubation.

Results:

The highest overall logarithmic reduction factors (RF) were obtained from CHX+CP (log RF 3.56 p<0.01; Mann-Whitney U test), followed by CP (log RF 3.27 p<0.01) and CHX alone (log RF 2.65 p<0.01) related to the control. All disinfection methods showed significantly lower CFU counts compared to the control group in 300 µm and 800 µm (both p<0.01, Kruskal-Wallis test).

Discussion:

The adjuvant use of CP might be beneficial in highly infected root canals to improved disinfection. However, the disinfection effect against Enterococcus faecalis of CP is comparable to ultrasonically activated CHX.

Impact of platform switching on marginal peri-implant bone-level changes. A systematic review and meta-analysis

OBJECTIVE

To address the focused question, is there an impact of platform switching (PS) on marginal bone level (MBL) changes around endosseous implants compared to implants with platform matching (PM) implant-abutment configurations?

MATERIAL AND METHODS

A systematic literature search was conducted using electronic databases PubMed, Web of Science, Journals@Ovid Full Text and Embase, manual search for human randomized clinical trials (RCTs) and prospective clinical controlled cohort studies (PCCS) reporting on MBL changes at implants with PS-, compared with PM-implant-abutment connections, published between 2005 and June 2013.

RESULTS

Twenty-two publications were eligible for the systematic review. The qualitative analysis of 15 RCTs and seven PCCS revealed more studies (13 RCTs and three PCCS) showing a significantly less mean marginal bone loss around implants with PS- compared to PM-implant-abutment connections, indicating a clear tendency favoring the PS technique. A meta-analysis including 13 RCTs revealed a significantly less mean MBL change (0.49 mm [CI95% 0.38; 0.60]) at PS implants, compared with PM implants (1.01 mm [CI95% 0.62; 1.40] (P < 0.0001).

CONCLUSIONS

The meta-analysis revealed a significantly less mean MBL change at implants with a PS compared to PM-implant-abutment configuration. Studies included herein showed an unclear as well as high risk of bias mostly, and relatively short follow-up periods. The qualitative analysis revealed a tendency favoring the PS technique to prevent or minimize peri-implant marginal bone loss compared with PM technique. Due to heterogeneity of the included studies, their results require cautious interpretation.

Regulatory mechanisms of testosterone-stimulated song in the sensorimotor nucleus HVC of female songbirds

Background

In male birds, influence of the sex steroid hormone testosterone and its estrogenic metabolites on seasonal song behavior has been demonstrated for many species. In contrast, female song was only recently recognized to be widespread among songbird species, and to date, sex hormone effects on singing and brain regions controlling song development and production (song control nuclei) have been studied in females almost exclusively using domesticated canaries (Serinus canaria). However, domesticated female canaries hardly sing at all in normal circumstances and exhibit only very weak, if any, song seasonally under the natural photoperiod. By contrast, adult female European robins (Erithacus rubecula) routinely sing during the winter season, a time when they defend feeding territories and show elevated circulating testosterone levels. We therefore used wild female European robins captured in the fall to examine the effects of testosterone administration on song as well as on the anatomy and the transcriptome of the song control nucleus HVC (sic). The results obtained from female robins were compared to outcomes of a similar experiment done in female domesticated canaries.

Results

Testosterone treatment induced abundant song in female robins. Examination of HVC transcriptomes and histological analyses of song control nuclei showed testosterone-induced differentiation processes related to neuron growth and spacing, angiogenesis and neuron projection morphogenesis. Similar effects were found in female canaries treated with testosterone. In contrast, the expression of genes related to synaptic transmission was not enhanced in the HVC of testosterone treated female robins but was strongly up-regulated in female canaries. A comparison of the testosterone-stimulated transcriptomes indicated that brain-derived neurotrophic factor (BDNF) likely functions as a common mediator of the testosterone effects in HVC.

Conclusions

Testosterone-induced singing of female robins correlated with cellular differentiation processes in the HVC that were partially similar to those seen in the HVC of testosterone-treated female canaries. Other modes of testosterone action, notably related to synaptic transmission, appeared to be regulated in a more species-specific manner in the female HVC. Divergent effects of testosterone on the HVC of different species might be related to differences between species in regulatory mechanisms of the singing behavior.

Electronic supplementary material

The online version of this article (doi:10.1186/s12868-014-0128-0) contains supplementary material, which is available to authorized users.

Oral syphilis: a series of 5 cases

Syphilis is an infectious, usually sexually transmitted, disease caused by Treponema pallidum, subspecies pallidum. Because of the increasing prevalence in Europe during the past few years, dentists could be confronted with patients with oral manifestations of syphilis. Because oral lesions are highly contagious, it is vital to make the correct diagnosis quickly to initiate the proper therapy and to interrupt the chain of infection. We present the cases of 5 patients with syphilis-related oral lesions. These cases are representative because of their clinical presentation, age, and gender distribution and the diagnostic approach. The aim of the present report is to emphasize the importance of the dentist knowing and identifying syphilis in different stages to diagnose the disease and institute treatment at an early stage.

Maximized song learning of juvenile male zebra finches following BDNF expression in the HVC

During song learning, vocal patterns are matched to an auditory memory acquired from a tutor, a process involving sensorimotor feedback. Song sensorimotor learning and song production of birds is controlled by a set of interconnected brain nuclei, the song control system. In male zebra finches, the beginning of the sensorimotor phase of song learning parallels an increase of the brain-derived neurotrophic factor (BDNF) in just one part of the song control system, the forebrain nucleus HVC. We report here that transient BDNF-mRNA upregulation in the HVC results in a maximized copying of song syllables. Each treated bird shows motor learning to an extent similar to that of the selected best learners among untreated zebra finches. Because this result was not found following BDNF overexpression in the target areas of HVC within the song system, HVC-anchored mechanisms are limiting sensorimotor vocal learning.

Characterization and identification of the protein partners of Fn3 domain in FnTm2

Recently, a novel transmembrane protein was found to be up-regulated in the auditory learning pathway of birds and mammals. The protein, FnTm2, was predicted to have an extracellular fibronectin III (Fn3) domain and a single transmembrane domain. By contrast to other studied Fn3 domains the extracellular domain of FnTm2 bears several cysteine residues, which are predicted to form disulfide bonds. The Fn3 domain of the FnTm2 protein was expressed in DH5-α Escherichia coli (E. coli) cells, purified and characterized by circular dichroism (CD). In order to identify binding partners to Fn3, the isolated protein was incubated with bird brain lysate for a pull down treatment. Of the proteins recognized, myelin basic protein (MBP) was identified as a bona fide partner; it was further characterized for binding to Fn3 in vitro via fluorescence spectroscopy and confirmed via isothermal calorimetry (ITC).

Genomic resources for songbird research and their use in characterizing gene expression during brain development

Vocal learning and neuronal replacement have been studied extensively in songbirds, but until recently, few molecular and genomic tools for songbird research existed. Here we describe new molecular/genomic resources developed in our laboratory. We made cDNA libraries from zebra finch (Taeniopygia guttata) brains at different developmental stages. A total of 11,000 cDNA clones from these libraries, representing 5,866 unique gene transcripts, were randomly picked and sequenced from the 3' ends. A web-based database was established for clone tracking, sequence analysis, and functional annotations. Our cDNA libraries were not normalized. Sequencing ESTs without normalization produced many developmental stage-specific sequences, yielding insights into patterns of gene expression at different stages of brain development. In particular, the cDNA library made from brains at posthatching day 30-50, corresponding to the period of rapid song system development and song learning, has the most diverse and richest set of genes expressed. We also identified five microRNAs whose sequences are highly conserved between zebra finch and other species. We printed cDNA microarrays and profiled gene expression in the high vocal center of both adult male zebra finches and canaries (Serinus canaria). Genes differentially expressed in the high vocal center were identified from the microarray hybridization results. Selected genes were validated by in situ hybridization. Networks among the regulated genes were also identified. These resources provide songbird biologists with tools for genome annotation, comparative genomics, and microarray gene expression analysis.

FnTm2, a novel brain-specific transcript, is dynamically expressed in the song learning circuit of the zebra finch

Zebra finch males learn their song by imitation, a process influenced by social variables. The neural pathways for acquisition and production of learned song are known, but the cellular and molecular underpinnings are not. Here we describe a novel gene named "FnTm2" ("Phantom 2") that is predicted to encode a small protein (220 aa) with a single fibronectin type III domain and a single transmembrane domain. This gene shows great variability in its expression in song system neurons of the anterior forebrain pathway (AFP), a circuit that influences song discrimination and is necessary for normal song acquisition. AFP nuclei that express FnTm2 include the nucleus HVC (its Area X-projecting neurons), Area X, and LMAN (core and shell). FnTm2 expression does not correlate with singing behavior like the immediate early gene ZENK. It is expressed variably during sleeping hours and is not dependent on an intact song circuit. FnTm2's expression is sensitive to hearing, because in deafened birds its expression is substantially reduced in the core of LMAN. Furthermore, a comparison of FnTm2 expression between mice and zebra finches revealed a conserved pattern of expression in the "limbic system." We suggest that FnTm2 may be sensitive to affective and/or attentional states and thus may provide insights on how social variables influence the production and discrimination of learned vocalizations.

Expression profiling of intermingled long-range projection neurons harvested by laser capture microdissection

Gene expression data are most useful if they can be associated with specific cell types. This is particularly so in an organ such as the brain, where many different cell types lie in close proximity to each other. We used zebra finches (Taeniopygia guttata), fluorescent tracers and laser capture microdissection (LCM) to collect projection neurons and their RNAs from two interspersed populations from the same animal. RNA amplified from each cell class was reverse transcribed, fluorescently labeled, and hybridized to cDNA microarrays of genes expressed in the zebra finch brain. We applied strict fold-expression criteria, supplemented by statistical analysis, to single out genes that showed the most extreme and consistent differential expression between the two cell classes. Confirmation of the true expression pattern of these genes was made by in situ hybridization and Taqman quantitative PCR (qPCR). High quality RNA was obtained, too, from backfilled neurons birth-dated with bromodeoxyuridine (BrdU). We also quantified changes in the levels of three genes after singing behavior using qPCR. Thus, we have brought together a combination of techniques allowing for the molecular profiling of intermingled populations of projection neurons of known connectivity, age and experience, which should constitute a powerful tool for CNS research.

Replaceable neurons and neurodegenerative disease share depressed UCHL1 levels

Might there be systematic differences in gene expression between neurons that undergo spontaneous replacement in the adult brain and those that do not? We first explored this possibility in the high vocal center (HVC) of male zebra finches by using a combination of neuronal tracers, laser capture microdissection, and RNA profiling. HVC has two kinds of projection neurons, one of which continues to be produced and replaced in adulthood. HVC neurons of the replaceable kind showed a consistent and robust underexpression of the deubiquitination gene ubiquitin carboxyl-terminal hydrolase (UCHL1) that is involved with protein degradation. Singing behavior, known to increase the survival of adult-born HVC neurons in birds, significantly up-regulated the levels of UCHL1 in the replaceable neurons but not in their equally active nonreplaceable counterparts. We then looked in the mouse brain and found relatively low UCHL1 expression in granule neurons of the hippocampus and olfactory bulb, two well characterized types of replaceable neurons in mammals. UCHL1 dysfunction has been associated with neurodegeneration in Parkinson's, Alzheimer's, and Huntington's disease patients. In all these instances, reduced UCHL1 function may jeopardize the survival of CNS neurons.

Dynamics and localization of activin A expression in rat gastric ulcers

BACKGROUND

Activin A, the homodimer of the activin/inhibin betaA subunit, has been shown to participate in cutaneous wound healing. In this study we intended to determine its part in gastric ulceration.

METHODS

Activin A expression was studied by immunohistochemistry and in situ hybridization in acetic-acid-induced chronic gastric ulcers in rat. The dynamics of this process were also assessed by quantitative real time RT-PCR and RNase protection assays (RPA). The effects of different doses of this cytokine on epithelial and mesenchymal cell proliferation were quantitated in vitro.

RESULTS

Low amounts of activin A and its mRNA were expressed by epithelia, endothelia and fibroblasts in intact gastric tissue. Granulation tissue of gastric ulcers and gastric glands adjacent to the ulcer rim expressed markedly increased amounts of activin protein as well as activin/inhibin betaA mRNA. RPA and RT-PCR studies revealed a more than 3-fold increase in the relative abundance of this mRNA. Activin A did not affect the proliferation rate of fibroblasts and epithelial cells in vitro.

CONCLUSIONS

Activin A participates in gastric ulcer healing in a similar fashion as in cutaneous wounding. Its expression on protein and mRNA level is markedly increased in ulcer base and rim.

Upregulation and activation of the Nrf-1 transcription factor in the lesioned hippocampus

The Nrf-1 and Nrf-2 transcription factors play a pivotal role in the cellular defence against the toxic effects of reactive oxygen species (ROS). Although ROS are key effectors of neuronal death after ischaemic and traumatic brain injury, it is not known whether Nrf-1 and Nrf-2 are involved in neuroprotective signalling. Here, we analysed the temporal and spatial expression pattern of Nrf-1 and Nrf-2 after unilateral excitotoxic lesion of mouse hippocampus. In marked contrast to previous in vitro studies, where upregulation of these transcription factors on the mRNA level was never detected, we found a strong induction of Nrf-1 mRNA and protein expression in neurons of the lesioned hippocampus, accompanied by a weak elevation of Nrf-2 mRNA levels. Nrf-1 predominantly localized to the nucleus in the injured hippocampus. Furthermore, expression of the cytoprotective enzyme, heme oxygenase-1, a major target of Nrf-1 and Nrf-2 action, was coregulated with Nrf-1 in the same hippocampal neurons, suggesting that Nrf-1 is functionally active. Because Nrf-1 and Nrf-2 are potent inducers of various cytoprotective proteins, our data suggest a role of Nrf-1 and Nrf-2 in neuronal survival after acute brain injury.

The roles of activins in repair processes of the skin and the brain

A recent study from our laboratory demonstrated a strong upregulation of activin expression during cutaneous wound healing. To further analyze the role of activin A in skin morphogenesis and wound repair, we generated transgenic mice that overexpress activin A under the control of the keratin 14 promoter. The latter targets expression of transgenes to the basal, proliferating layer of the epidermis. Hetero- as well as homozygous transgenic animals were viable and fertile. However, they were smaller than non-transgenic littermates and they had smaller ears and shorter tails. Histological analysis of their skin revealed dermal hyperthickening, mainly due to the replacement of fatty tissue by connective tissue, and an increase in suprabasal, partially differentiated epidermal layers. After cutaneous injury, a strong enhancement of granulation tissue formation was observed. Furthermore, the extent of re-epithelialization was increased in some of the wounds. These data demonstrate that activin A is a potent stimulator of the wound healing process. Using an in vivo model of local brain injury, we found that activin A also plays a significant role in the early cellular response to neuronal damage. Expression of activin mRNA and protein is markedly upregulated within a few hours of injury. If applied exogenously, recombinant activin A is capable of rescuing neurons from acute cell death. Studying the interaction between bFGF, a well-established neuroprotective agent, which is currently being tested in stroke patients, and activin A, we arrived at the unexpected conclusion that it is the strong induction of activin A by bFGF which endows the latter with its beneficial actions in patients. These findings suggest that the development of substances directly targeting activin expression or receptor binding should offer new possibilities in the acute treatment of stroke and brain trauma.