A taste of wilderness: supplementary feeding of red deer (Cervus elaphus) increases individual bacterial microbiota diversity but lowers abundance of important gut symbionts

The gut microbiome plays a crucial role in the health and well-being of animals. It is especially critical for ruminants that depend on this bacterial community for digesting their food. In this study, we investigated the effects of management conditions and supplemental feeding on the gut bacterial microbiota of red deer (Cervus elaphus) in the Bavarian Forest National Park, Germany. Fecal samples were collected from free-ranging deer, deer within winter enclosures, and deer in permanent enclosures. The samples were analyzed by high-throughput sequencing of the 16 S rRNA gene. The results showed that the gut bacterial microbiota differed in diversity, abundance, and heterogeneity within and between the various management groups. Free-ranging deer exhibited lower alpha diversity compared with deer in enclosures, probably because of the food supplementation available to the animals within the enclosures. Free-living individuals also showed the highest beta diversity, indicating greater variability in foraging grounds and plant species selection. Moreover, free-ranging deer had the lowest abundance of potentially pathogenic bacterial taxa, suggesting a healthier gut microbiome. Winter-gated deer, which spent some time in enclosures, exhibited intermediate characteristics between free-ranging and all-year-gated deer. These findings suggest that the winter enclosure management strategy, including supplementary feeding with processed plants and crops, has a significant impact on the gut microbiome composition of red deer. Overall, this study provides important insights into the effects of management conditions, particularly winter enclosure practices, on the gut microbiome of red deer. Understanding these effects is crucial for assessing the potential health implications of management strategies and highlights the value of microbiota investigations as health marker.

Estimating effective survey duration in camera trap distance sampling surveys

Among other approaches, camera trap distance sampling (CTDS) is used to estimate animal abundance from unmarked populations. It was formulated for videos and observation distances are measured at predetermined 'snapshot moments'. Surveys recording still images with passive infrared motion sensors suffer from frequent periods where animals are not photographed, either because of technical delays before the camera can be triggered again (i.e. 'camera recovery time') or because they remain stationary and do not immediately retrigger the camera following camera recovery time (i.e. 'retrigger delays'). These effects need to be considered when calculating temporal survey effort to avoid downwardly biased abundance estimates. Here, we extend the CTDS model for passive infrared motion sensor recording of single images or short photo series. We propose estimating 'mean time intervals between triggers' as combined mean camera recovery time and mean retrigger delays from the time interval distribution of pairs of consecutive pictures, using a Gamma and Exponential function, respectively. We apply the approach to survey data on red deer, roe deer and wild boar. Mean time intervals between triggers were very similar when estimated empirically and when derived from the model-based approach. Depending on truncation times (i.e. the time interval between consecutive pictures beyond which data are discarded) and species, we estimated mean time intervals between retriggers between 8.28 and 15.05 s. Using a predefined snapshot interval, not accounting for these intervals, would lead to underestimated density by up to 96% due to overestimated temporal survey effort. The proposed approach is applicable to any taxa surveyed with camera traps. As programming of cameras to record still images is often preferred over video recording due to reduced consumption of energy and memory, we expect this approach to find broad application, also for other camera trap methods than CTDS.

Spatial variation in red deer density in a transboundary forest ecosystem

Forests in Europe are exposed to increasingly frequent and severe disturbances. The resulting changes in the structure and composition of forests can have profound consequences for the wildlife inhabiting them. Moreover, wildlife populations in Europe are often subjected to differential management regimes as they regularly extend across multiple national and administrative borders. The red deer Cervus elaphus population in the Bohemian Forest Ecosystem, straddling the Czech-German border, has experienced forest disturbances, primarily caused by windfalls and bark beetle Ips typographus outbreaks during the past decades. To adapt local management strategies to the changing environmental conditions and to coordinate them across the international border, reliable estimates of red deer density and abundance are highly sought-after by policymakers, wildlife managers, and stakeholders. Covering a 1081-km² study area, we conducted a transnational non-invasive DNA sampling study in 2018 that yielded 1578 genotyped DNA samples from 1120 individual red deer. Using spatial capture-recapture models, we estimated total and jurisdiction-specific abundance of red deer throughout the ecosystem and quantified the role of forest disturbance and differential management strategies in shaping spatial heterogeneity in red deer density. We hypothesised that (a) forest disturbances provide favourable habitat conditions (e.g., forage and cover), and (b) contrasting red deer management regimes in different jurisdictions create a differential risk landscape, ultimately shaping density distributions. Overall, we estimated that 2851 red deer (95% Credible Interval = 2609-3119) resided in the study area during the sampling period, with a relatively even overall sex ratio (1406 females, 95% CI = 1229-1612 and 1445 males, 95% CI = 1288-1626). The average red deer density was higher in Czechia (3.5 km^-2, 95% CI = 1.2-12.3) compared to Germany (2 km^-2, 95% CI = 0.2-11). The effect of forest disturbances on red deer density was context-dependent. Forest disturbances had a positive effect on red deer density at higher elevations and a negative effect at lower elevations, which could be explained by partial migration and its drivers in this population. Density of red deer was generally higher in management units where hunting is prohibited. In addition, we found that sex ratios differed between administrative units and were more balanced in the non-intervention zones. Our results show that the effect of forest disturbances on wild ungulates is modulated by additional factors, such as elevation and ungulate management practices. Overall density patterns and sex ratios suggested strong gradients in density between administrative units. With climate change increasing the severity and frequency of forest disturbances, population-level monitoring and management are becoming increasingly important, especially for wide-ranging species as both wildlife and global change transcend administrative boundaries.

Deer Behavior Affects Density Estimates With Camera Traps, but Is Outweighed by Spatial Variability

Density is a key trait of populations and an essential parameter in ecological research, wildlife conservation and management. Several models have been developed to estimate population density based on camera trapping data, including the random encounter model (REM) and camera trap distance sampling (CTDS). Both models need to account for variation in animal behavior that depends, for example, on the species and sex of the animals along with temporally varying environmental factors. We examined whether the density estimates of REM and CTDS can be improved for Europe’s most numerous deer species, by adjusting the behavior-related model parameters per species and accounting for differences in movement speeds between sexes, seasons, and years. Our results showed that bias through inadequate consideration of animal behavior was exceeded by the uncertainty of the density estimates, which was mainly influenced by variation in the number of independent observations between camera trap locations. The neglection of seasonal and annual differences in movement speed estimates for REM overestimated densities of red deer in autumn and spring by ca. 14%. This GPS telemetry-derived parameter was found to be most problematic for roe deer females in summer and spring when movement behavior was characterized by small-scale displacements relative to the intervals of the GPS fixes. In CTDS, density estimates of red deer improved foremost through the consideration of behavioral reactions to the camera traps (avoiding bias of max. 19%), while species-specific delays between photos had a larger effect for roe deer. In general, the applicability of both REM and CTDS would profit profoundly from improvements in their precision along with the reduction in bias achieved by exploiting the available information on animal behavior in the camera trap data.

The emergence of ecotypes in a parasitoid wasp: a case of incipient sympatric speciation in Hymenoptera?

Background

To understand which reproductive barriers initiate speciation is a major question in evolutionary research. Despite their high species numbers and specific biology, there are only few studies on speciation in Hymenoptera. This study aims to identify very early reproductive barriers in a local, sympatric population of Nasonia vitripennis (Walker 1836), a hymenopterous parasitoid of fly pupae. We studied ecological barriers, sexual barriers, and the reduction in F1-female offspring as a postmating barrier, as well as the population structure using microsatellites.

Results

We found considerable inbreeding within female strains and a population structure with either three or five subpopulation clusters defined by microsatellites. In addition, there are two ecotypes, one parasitizing fly pupae in bird nests and the other on carrion. The nest ecotype is mainly formed from one of the microsatellite clusters, the two or four remaining microsatellite clusters form the carrion ecotype. There was slight sexual isolation and a reduction in F1-female offspring between inbreeding strains from the same microsatellite clusters and the same ecotypes. Strains from different microsatellite clusters are separated by a reduction in F1-female offspring. Ecotypes are separated only by ecological barriers.

Conclusions

This is the first demonstration of very early reproductive barriers within a sympatric population of Hymenoptera. It demonstrates that sexual and premating barriers can precede ecological separation. This indicates the complexity of ecotype formation and highlights the general need for more studies within homogenous populations for the identification of the earliest barriers in the speciation process.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12862-021-01938-y.

Implementation of anesthesia quality indicators in Germany : A prospective, national, multicenter quality improvement study

BACKGROUND

In 2016 the German Society of Anesthesiology and Intensive Care Medicine (DGAI) and the Association of German Anesthetists (BDA) published 10 quality indicators (QI) to compare and improve the quality of anesthesia care in Germany. So far, there is no evidence for the feasibility of implementation of these QI in hospitals.

OBJECTIVE

This study tested the hypothesis that the implementation of the 10 QI is feasible in German hospitals.

MATERIAL AND METHODS

This prospective three-phase national multicenter quality improvement study was conducted in 15 German hospitals and 1 outpatient anesthesia center from March 2017 to February 2018. The trial consisted of an initial evaluation of pre-existing structures and processes by the heads of the participating anesthesia departments, followed by a 6-month implementation phase of the QI as well as a final re-evaluation phase. The implementation procedure was supported by web-based implementation aids ( www.qi-an.org ) and internal quality management programs. The primary endpoint was the difference in the number of implemented QI per center before and after implementation. Secondary endpoints were the number of newly implemented QI per center, the overall number of successful implementations of each QI, the identification of problems during the implementation as well as the kind of impediments preventing the QI implementation.

RESULTS

The average number of implemented QI increased from 5.8 to 6.8 (mean of the differences 1.1 ± 1.3; P < 0.01). Most frequently the QI perioperative morbidity and mortality report (5 centers) and the QI temperature management (4 centers) could be implemented. After the implementation phase, the QI incidence management and patient blood management were implemented in all 16 centers. Implementation of other quality indicators failed mainly due to a lack of time and lack of structural resources.

CONCLUSION

In this study the implementation of QI was proven to be mostly feasible in the participating German hospitals. Although several QI could be implemented with minor effort, more time, financial and structural resources would be required for some QI, such as the QI postoperative visit.

[Implementation of anesthesia quality indicators in Germany : A prospective, national, multicenter quality improvement study]

BACKGROUND

In 2016 the German Society of Anesthesiology and Intensive Care Medicine (DGAI) and the Association of German Anesthetists (BDA) published 10 quality indicators (QI) to compare and improve the quality of anesthesia care in Germany. So far, there is no evidence for the feasibility of implementation of these QI in hospitals.

OBJECTIVE

This study tested the hypothesis that the implementation of the 10 QI is feasible in German hospitals.

MATERIAL AND METHODS

This prospective three-phase national multicenter quality improvement study was conducted in 15 German hospitals and 1 outpatient anesthesia center from March 2017 to February 2018. The trial consisted of an initial evaluation of pre-existing structures and processes by the heads of the participating anesthesia departments, followed by a 6-month implementation phase of the QI as well as a final re-evaluation phase. The implementation procedure was supported by web-based implementation aids ( www.qi-an.org ) and internal quality management programs. The primary endpoint was the difference in the number of implemented QI per center before and after implementation. Secondary endpoints were the number of newly implemented QI per center, the overall number of successful implementations of each QI, the identification of problems during the implementation as well as the kind of impediments preventing the QI implementation.

RESULTS

The average number of implemented QI increased from 5.8 to 6.8 (mean of the differences 1.1 ± 1.3; P < 0.01). Most frequently the QI perioperative morbidity and mortality report (5 centers) and the QI temperature management (4 centers) could be implemented. After the implementation phase, the QI incidence management and patient blood management were implemented in all 16 centers. Implementation of other quality indicators failed mainly due to a lack of time and lack of structural resources.

CONCLUSION

In this study the implementation of QI was proven to be mostly feasible in the participating German hospitals. Although several QI could be implemented with minor effort, more time, financial and structural resources would be required for some QI, such as the QI postoperative visit.

Use of a novel vessel-sealing device for peripheral lung biopsy and lung lobectomy in a cadaveric model

OBJECTIVE

To evaluate the Caiman vessel-sealing device for peripheral lung biopsy and total lung lobectomy in cadaveric canine lung lobes.

MATERIAL AND METHODS

Twelve lung lobes were randomly assigned to peripheral lung biopsy (n=6) or total lung lobectomy (n=6) with the 12-mm Caiman vessel-sealing device. Lungs were connected to a ventilator set at 10 breaths per minute with an initial pressure of 5 cm H₂ O during the procedure. The lungs were submerged in water for leak testing and the pressure increased until leakage occurred.

RESULTS

Mean airway pressure at which leakage occurred was 39.17 ±13.20 cm H₂ O for peripheral lung biopsies and 38.33 ±13.67 cm H₂ O for total lung lobectomies. None of the samples leaked below 25 cm H₂ O, which is well above the physiologic airway pressure. Histologically, the largest bronchial diameter at the sealed area was 8.84 mm and the extent of collateral damage was approximately 2.7 mm in all specimens.

CLINICAL SIGNIFICANCE

The Caiman vessel-sealing device was successfully used for peripheral lung biopsy and total lung lobectomy in cadaveric canine lung lobes. All sealed lung lobes tolerated supra-physiologic airway pressure, displayed minimal collateral damage, and were of good diagnostic quality. Further experimental studies are needed to evaluate the clinical safety of the device for peripheral lung biopsy or total lung lobectomy.

Vasomotion of mice mesenteric arteries during low oxygen levels

Background

Ischemia of intestinal organs is a main cause of complications in surgical intensive care patients. Changes in the tonus of arteries contributing to vascular resistance play an important role in the determination of blood flow and thus oxygen supply of various abdominal organs. It is generally acknowledged that hypoxia itself is able to alter arterial tonus and thus blood flow.

Methods

The present study compared the effects of various degrees of hypoxia on second-order mesenteric arteries from male C57BL/6J mice. After vessel isolation and preparation, we assessed vessel diameter using an arteriograph perfusion chamber. Investigating mechanisms promoting hypoxia-induced vasodilatation, we performed experiments in Ca²⁺-containing and Ca²⁺-free solutions, and furthermore, Ca²⁺-influx was inhibited by NiCl₂, eNOS^−/−-, and TASK1^−/−-mice were investigated too.

Results

Mild hypoxia 14.4% O₂ induced, in 50% of mesenteric artery segments from wild-type (wt) mice, a vasodilatation; severe hypoxia recruited further segments responding with vasodilatation reaching 80% under anoxia. However, the extension of dilatation of luminal arterial diameter reduced from 1.96% ± 0.55 at 14.4% O₂ to 0.68% ± 0.13 under anoxia. Arteries exposed to hypoxia in Ca²⁺-free solution responded to lower oxygen levels with increasing degree of vasodilatation (0.85% ± 0.19 at 14.4% O₂ vs. 1.53% ± 0.42 at 2.7% O₂). Inhibition of voltage-gated Ca²⁺-influx using NiCl₂ completely diminished hypoxia-induced vasodilatation. Instead, all arterial segments investigated constricted. Furthermore, we did not observe altered hypoxia-induced vasomotion in eNOS^−/−- or TASK1^−/− mice compared to wt animals.

Conclusions

The present study demonstrated that hypoxic vasodilatation in mice mesenteric arteries is mediated by a NO-independent mechanism. In this experimental setting, we found evidence for Ca²⁺-mediated activation of ion channels causing hypoxic vasodilatation.

Electronic supplementary material

The online version of this article (10.1186/s40001-018-0335-8) contains supplementary material, which is available to authorized users.

STED microscopy visualizes energy deposition of single ions in a solid-state detector beyond diffraction limit

Fluorescent nuclear track detectors (FNTDs) allow for visualization of single-particle traversal in clinical ion beams. The point spread function of the confocal readout has so far hindered a more detailed characterization of the track spots-the ion's characteristic signature left in the FNTD. Here we report on the readout of the FNTD by optical nanoscopy, namely stimulated emission depletion microscopy. It was firstly possible to visualize the track spots of carbon ions and protons beyond the diffraction limit of conventional light microscopy with a resolving power of approximately 80 nm (confocal: 320 nm). A clear discrimination of the spatial width, defined by the full width half maximum of track spots from particles (proton and carbon ions), with a linear energy transfer (LET) ranging from approximately 2-1016 keV µm^-1 was possible. Results suggest that the width depends on LET but not on particle charge within the uncertainties. A discrimination of particle type by width thus does not seem possible (as well as with confocal microscopy). The increased resolution, however, could allow for refined determination of the cross-sectional area facing substantial energy deposition. This work could pave the way towards development of optical nanoscopy-based analysis of radiation-induced cellular response using cell-fluorescent ion track hybrid detectors.

Abstract P6-10-05: A pilot study of radiation (RT) and CTLA4-mediated checkpoint blockade with tremelimumab for the treatment of breast cancer brain metastases (BCBM)

This abstract was withdrawn by the authors.

Intravenous immunoglobulin in necrotizing fasciitis - A case report and review of recent literature

Introduction

Necrotizing fasciitis (NF) is an inflammatory disease of the soft tissue, which causes local tissue destruction and can lead to lethal septic shock. The therapy consists of early surgical treatment of the septic focus and an accompanying broad spectrum antibiotic therapy. Recent literature considers the additional use of immunoglobulin therapy in severe soft skin and tissue infections.

Presentation of case

In this report, we describe the case of a 33-year-old male patient treated at a university hospital intensive care unit because of an NF of his left leg. The patient rapidly developed a complicated septic disease after a minor superficial trauma. Despite intense microbiological diagnosis, no causative pathogens were identified. After non-responding to established broad anti-infective treatment, the patient received intravenous immunoglobulin, that rapidly improved his clinical condition.

Discussion

NF represents a disease processes, which is characterized by fulminant, widespread necrosis of soft tissue, systemic toxicity, and high mortality (>30%). Beside the surgical debridement and broad spectrum antibiotic therapy IVIg therapy might be an additional option in the treatment of NF. But the current literature supporting the use of IVIG in NF is largely based on retrospective or case-controlled studies, and only small randomized trials.

Conclusion

The demonstrated case suggests that IVIg treatment of patients with NF can be considered in case of hemodynamic unstable, critically ill patients. Although randomized controlled trials are missing, some patients might benefit from diminishing hyperinflammation by immunoglobins.

•

Necrotizing fasciitis (NF) is an inflammatory disease, which causes local tissue destruction up to lethal septic shock.

•

We describe the case of a 33-year-old male patient representing an NF of his left leg.

•

After non-responding to established broad anti-infective treatment, the patient received immunoglobulin (IVIg).

•

The presented case suggests that IVIg treatment of patients with NF might be considered in case of critically ill patients.

Stimulation of duodenal biopsies and whole blood from dogs with food-responsive chronic enteropathy and healthy dogs with Toll-like receptor ligands and probiotic Enterococcus faecium

The composition of the microbiome plays a significant role in the pathogenesis of inflammatory bowel disease (IBD) in humans and chronic enteropathies (CE) in dogs. The administration of probiotic micro-organisms is one way of modulating the microbiome, but experiments elucidating mechanisms of action of probiotics in the intestine of healthy and CE dogs are lacking. The aim of our study was to investigate the effects of different Toll-like receptor (TLR) ligands and Enterococcus faecium (EF) on ex vivo cultured duodenal samples and whole blood (WB) from dogs with food-responsive chronic enteropathy (FRE) when compared to healthy dogs. Biopsy stimulation was performed in 17 FRE and 11 healthy dogs; WB stimulation was performed in 16 FRE and 16 healthy dogs. Expression of TLR2, 4, 5 and 9, IL-17A, IL-22, IFNy, TNFα, IL-4, IL-10, TGFβ and PPARy was determined in biopsies by quantitative polymerase chain reaction (PCR). In addition, production of TNFα, IL-10, IFNy and IL-17A protein in WB and biopsy supernatants was assessed by ELISA. Treatment with individual TLR ligands or EF induced a variety of changes in the expression of different TLRs and cytokines, but not necessarily a consistent change with a single stimulating agent. Even though cytokine protein could not be detected in supernatants from ex vivo stimulated biopsies, we found TNFα protein responses in blood to be opposite of the transcriptional responses seen in the biopsies. Stimulation of canine duodenal biopsies with TLR ligands can potentially induce anti-inflammatory gene expression, especially in healthy tissue, whereas the effects of EF were limited.

Lethal cervical abscess following bisphosphonate related osteonecrosis of the jaw

CONTEXT

Bisphosphonates are common drugs used in the management of bone metabolic diseases. Because of their recently increased use, their adverse effects, especially bisphosphonate-related osteonecrosis of the jaw (BRONJ), are monitored more frequently. BRONJ is a critical challenge in craniofacial surgery and is difficult to treat. Its occurrence is either spontaneous or follows dentoalveolar surgery. Typical complications of BRONJ are painful exposed bone, pathological fractures, extra-oral fistula, and local infections.

OBJECTIVE

The aim of this paper is to report a rare case of bacterial embolism in the internal jugular vein after a BRONJ-induced submandibular abscess resulting in bacterial sepsis, multi-organ failure syndrome, and death.

CASE ILLUSTRATION

A 59-year-old female patient developed severe BRONJ (stage II) with recurrent abscesses after oral osteoporosis therapy with alendronic acid. A subsequent submandibular abscess led to bacterial embolism of the left internal jugular vein, causing sepsis and death.

DISCUSSION

Prevention, early detection and management of BRONJ remain a crucial challenge in craniofacial clinical practice. Despite several therapeutic approaches described in the current literature, none have undergone bedside application.

CONCLUSION

Considering this report of death after recurrent abscesses following BRONJ, the use of bisphosphonates should be carefully monitored in order to prevent such severe complications.

Co-occurrence of an intraventricular meningioma and cholesterol granuloma of the choroid plexus in a cat

A 12-year-old domestic shorthair cat was presented with neurologic signs localized to the forebrain. Magnetic resonance imaging (MRI) of the brain revealed a space occupying lesion within the third and the lateral ventricles. The lesion had areas of disparate signal characteristics and exerted a mass effect on the surrounding parenchyma and ventricular system. The histologic examination identified the co-existence of two intraventricular masses: a meningioma and a choroid plexus cholesterol granuloma.

Co-occurrence of an intraventricular meningioma and cholesterol granuloma of the choroid plexus in a cat

A 12-year-old domestic shorthair cat was presented with neurologic signs localized to the forebrain. Magnetic resonance imaging (MRI) of the brain revealed a space occupying lesion within the third and the lateral ventricles. The lesion had areas of disparate signal characteristics and exerted a mass effect on the surrounding parenchyma and ventricular system. The histologic examination identified the co-existence of two intraventricular masses: a meningioma and a choroid plexus cholesterol granuloma.

[Near-infrared spectroscopy in sepsis therapy : predictor of a low central venous oxygen saturation]

BACKGROUND

Early goal-directed hemodynamic optimization has become a cornerstone of sepsis therapy. One major defined goal is to achieve adequate central venous oxygen saturation (SO(2)). This study aimed to investigate the correlation between central venous SO(2) and frontal cerebral near-infrared spectroscopy (NIRS) measurement in patients with severe sepsis and septic shock. The NIRS method provides non-invasive measurement of regional oxygen saturation (rSO(2)) in tissues approximately 2 cm below the optical NIRS sensors which depends on arterial, capillary and venous blood. Thus this system gives site-specific real-time data about the balance of oxygen supply and demand.

METHODS

This was a secondary analysis from a prospective study of surgical intensive care (ICU) patients in the early phase of severe sepsis or septic shock. Bilateral cerebral rSO(2), central venous SO(2), arterial oxygen saturation (S(a)O(2)) and other surrogate parameters of oxygen supply, such as hemoglobin, partial pressure of oxygen and oxygen content in arterial blood were recorded.

RESULTS

A total of 16 ICU patients (4 women, median age 65.5 years) were included in the study. As sepsis focus an intra-abdominal infection was detected in 62.5 % of patients, severe pneumonia was determined in 31.3 % and skin and soft tissue infections were recognized in 12.5 %. At study inclusion 50 % of patients had septic shock, the median sequential organ failure assessment (SOFA) score was 10.2 (interquartile range 5.25-8.75) and the median acute physiology and chronic health evaluation II (APACHE II) score was 26 (range 23.25-29.75). Mortality at day 28 was 37.5 %. Minimum rSO(2) (median 58) and right-sided rSO(2) (median 58) values showed a significant correlation in the analysis of receiver operating characteristics (area under the curve 0.844, p= 0.045). A central venous SO(2)< 70 % was indicated by rSO(2)< 56.5 with sensitivity and specificity of 75 % and 100 %, respectively.

CONCLUSIONS

Cerebral NIRS could provide a fast and easily available side effect-free monitoring that could be used in addition to established procedures for goal-directed treatment in the early phase of sepsis. Further studies should be made in a larger population to verify the correlation found and to investigate the impact of NIRS-directed resuscitation treatment in early sepsis.

Hyperfine spectroscopy of the 1s(5)-2p(9) transition of 39Ar

We report on the first experimental determination of the hyperfine structure of the 1s(5)-2p(9) transition in (39)Ar. We give a detailed description of the sample preparation, spectroscopy cell cleaning, and spectroscopic setup. The resulting set of parameters consists of the hyperfine constants of the levels involved and the isotopic shift between (39)Ar and (40)Ar. With the achieved precision all laser frequencies necessary for the implementation of atom trap trace analysis for (39)Ar, i.e., laser cooling and repumping frequencies, are now known.

Characterization of C-, J- and V-region-genes of the feline T-cell receptor gamma

Lymphomas and leukemias are important neoplasias of domestic cats and human beings. In some cases it can be difficult to differentiate these tumors from reactive lymphatic hyperplasia. To overcome this problem, the diagnosis of lymphomas and leukemias in man is often supported by molecular techniques. To be able to establish such a technique in the cat we had to sequence the genes coding for the antigen receptors. As primary target in this study we choose the T-cell receptor gamma. Using 5'-and 3'-RACE techniques we were able to clone and sequence four different V-region genes, which can be clustered into two subgroups as well as six variants of the C-region gene. Additionally, we found eight J-region genes which can be classified into three subgroups. One of the V-region genes, six of the J-region genes and all C-region genes had not been described previously. All together we analysed 112 clones containing V- and J-region genes and 31 clones containing C-region genes. Sixty-six of these clones were full length containing the L-region as well as the 5'-UTR of the feline T-cell receptor gamma. The sequences of the V-region- and J-region-genes show sufficiently homologous areas that can be used to establish a small number of consensus-primers to be applied in molecular diagnosis of feline lymphomas and leukemias.

Extraventricular neurocytoma of the spinal cord in a dog

Central neurocytoma is a rare, prognostically favorable neuronal tumor of the human central nervous system, typically located intraventricularly near the foramen of Monro. Extraventricular cerebral neurocytomas and spinal tumors have also been reported. To date, however, neurocytomas have not been documented in domestic animal species. In this report, we describe a spinal cord tumor in a dog. The microscopic examination revealed tumor cells forming loosely packed clusters in some areas and palisades in other areas. In addition, they showed fine fibrillary neuropil-like areas of different sizes, sometimes resembling the "rosettes" of pineocytomas, as well as ependymoma-like perivascular pseudorosettes. The tumor cells had scant eosinophilic cytoplasm, with perinuclear halos, closely resembling the appearance of oligodendroglioma. Immunohistochemical staining showed expression of synaptophysin and neuron-specific enolase by tumor cells and pronounced in fibrillary areas. On the basis of histomorphology and immunohistochemical reactivity, the present tumor was diagnosed as extraventricular neurocytoma.

Multiple granulomas in three squirrel monkeys (Saimiri sciureus) caused by Mycobacterium microti

Mycobacterium microti, a member of the Mycobacterium tuberculosis complex, causes tuberculosis in small rodents and occasionally in other mammals including man. Three adult male squirrel monkeys, two with a history of lethargy, weakness and stridor and one with paralysis of the hind legs, were presented for necropsy. One of the two lethargic animals showed multiple granulomas in the mesentery, mesenteric lymph nodes, lung, liver, kidneys and spleen, while the other showed granulomas only in the lung. The animal with paralysis of the legs had an abscess-like lesion in the skeletal muscle of the neck, granulomas in the mesenteric and mediastinal lymph nodes, and a fracture of the thirteenth thoracic vertebra with severe lesions of the spinal cord. Histologically the granulomas showed typical features of tuberculous granulomas, i.e., central necrosis surrounded by epithelioid cells, multinucleated giant cells, inflammatory cells and a border of connective tissue. Ziehl-Neelsen stain demonstrated sporadic acid-fast bacilli within the granulomas, these organisms being identified as M. microti by microbiological and molecular methods.

Hypoxic increase in nitric oxidegeneration of rat sensory neurons requires activation of mitochondrial complex II and voltage-gated calcium channels

Recently, we have demonstrated that sensory neurons of rat lumbar dorsal root ganglia (DRG) respond to hypoxia with an activation of endothelial nitric oxide (NO) synthase (eNOS) resulting in enhanced NO production associated with mitochondria which contributes to resistance against hypoxia. Extracellular calcium is essential to this effect. In the present study on rat DRG slices, we set out to determine what types of calcium channels operate under hypoxia, and which upstream events contribute to their activation, thereby focusing upon mitochondrial complex II. Both the metallic ions Cd2+ and Ni2+, known to inhibit voltage-gated calcium channels and T-type channels, respectively, and verapamil and nifedipine, typical blocker of L-type calcium channels completely prevented the hypoxic neuronal NO generation. Inhibition of complex II by thenoyltrifluoroacetone at the ubiquinon binding site or by 3-nitropropionic acid at the substrate binding site largely diminished hypoxic-induced NO production while having an opposite effect under normoxia. An additional blockade of voltage-gated calcium channels entirely abolished the hypoxic response. The complex II inhibitor malonate inhibited both normoxic and hypoxic NO generation. These data show that complex II activity is required for increased hypoxic NO production. Since succinate dehydrogenase activity of complex II decreased at hypoxia, as measured by histochemistry and densitometry, we propose a hypoxia-induced functional switch of complex II from succinate dehydrogenase to fumarate reductase, which subsequently leads to activation of voltage-gated calcium channels resulting in increased NO production by eNOS.

Ethanol reduces excitability in a subgroup of primary sensory neurons by activation of BK(Ca) channels

Ethanol effects on the central nervous system have been well investigated and described in recent years; modulations, by ethanol, of several ligand-gated and voltage-gated ion channels have been found. In this paper, we describe a shortening of action potential duration (APD) by ethanol in approximately equal to 40% of small diameter neurons in rat dorsal root ganglia (DRG). In these neurons, designated as group A neurons, we observed an ethanol-induced increase in whole-cell outward-current. As iberiotoxin, a specific blocker of large-conductance calcium-activated K+ channels (BK(Ca) channels), blocks the effects of ethanol, we investigated the interaction between these channels and ethanol in outside-out patches. Open probability of BK(Ca) channels was increased 2-6 x depending on the concentration (40-80 mM approximately equal to 2-4 per thousand v/v) of ethanol. Functional consequences were a prolongation of the refractory period, which was reversible after addition of iberiotoxin, and reduced firing frequency during ethanol application. In contrast, another type of neuron (group B) showed a prolonged APD during application of ethanol which was irreversible in most cases. In 90% of cases, neurons of group A showed a positive staining for isolectin B4 (I-B4), a marker for nociceptive neurons. We suggest that the activation of BK(Ca) channels induced by clinically relevant concentrations of ethanol, the resulting modulations of APD and refractory period of DRG neurons, might contribute to clinically well-known ethanol-induced analgesia and paresthesia.

Acute iliac vein thrombosis in pregnancy treated successfully by streptokinase lysis: a case report

BACKGROUND

Postthrombotic syndrome is an important late complication after deep vein thrombosis in pregnancy. Thrombolytic agents are more efficient in preventing this condition but are rarely used in pregnant women.

CASE

A 22-year-old woman at 29 weeks of gestation presented with acute iliac vein thrombosis. After application of a heparin bolus, systemic streptokinase lysis was performed. Low-dose heparin therapy was continued for the remainder of the, otherwise unremarkable, pregnancy. Spontaneous delivery of a healthy girl was without complications and thromboprophylaxis with low-molecular heparin was continued.

CONCLUSION

Thrombolysis in pregnancy is possible and may help to prevent severe long-term sequelae of thrombosis in young women. Bleeding is a major risk, which must be considered and therapy should only be administered under close observation.

Muscarinic M2-receptors in rat thoracic dorsal root ganglia

The occurrence and distribution of the muscarinic M2-receptor subtype (M2R) was investigated in rat thoracic dorsal root ganglia (DRG). Messenger RNA for M2R was demonstrated by RT-PCR in total RNA from DRG. Immunoreactivity to M2R-protein was localized to 26% of sensory neurons, the majority of them (85%) belonging to the size class of 25-40 microm in diameter. Double-labeling (immuno)histochemistry revealed that all M2R-immunoreactive neurons bind the lectin, I-B4, whereas they are generally devoid of substance P-immunoreactivity. These data show the presence of M2R on a subpopulation of presumably nociceptive primary afferent neurons, thereby extending previous pharmacological and electrophysiological studies that indicated a role of M2R and/or M4R in inhibition of calcium channel currents in rat sensory neurons (Wanke, E., Bianchi, L., Mantegazza, M., Guatteo, E., Macinelli, E. and Ferroni, A., Muscarinic regulation of Ca2+ currents in rat sensory neurons: channel and receptor types, dose-response relationships and cross-talk pathways. Eur. J. Neurosci., 6 (1994) 381-391).

Resistance factors in colon cancer tissue and the adjacent normal colon tissue: glutathione S-transferases alpha and pi, glutathione and aldehyde dehydrogenase

Glutathione S-transferases (GST) alpha and pi, glutathione (GSH) and aldehyde dehydrogenase (ADH) were determined in colorectal cancer tissue specimens and in the adjacent normal colon tissue. The median contents in normal and cancer tissue were 8.1 (2.3-30.3) (5-95% quantiles) and 15.1 (5.3-50.3) microg/mg protein for GST pi (P = 0.035), 0.0 (0.0-1.4) and 0.4 (0.0-3.5) microg/mg protein for GST alpha (P = 0.019), 7.3 (1.3-22.7) and 5.6 (2.3-26.0) microg/mg protein for GSH (P = 0.171) and 30.8 (13.0-42.0) and 23.2 (9.0-32.9) microg/mg protein for ADH (P = 0.0017), respectively. Thus, the mean GST alpha and pi both significantly increased in colon cancer compared to the adjacent normal tissue, which underlines their importance as possible resistance factors. A highly significant correlation was obtained between the GSH content in colon cancer and normal tissue (P = 0.0017). Thus, the constitutive GSH expression seems to be maintained during tumor development. A similar correlation was obtained for ADH (P = 0.0075), but the median ADH was lower in cancer tissue compared to the adjacent normal tissue (P = 0.0017). Contrary to GSH and ADH, GST pi did not correlate between normal and colon cancer tissue. Whereas GSH and ADH correlated in normal colon tissue (P = 0.014), no significant correlation for GSH and ADH was observed in colon cancer tissue (P = 0.109). In conclusion, significant correlations between colon cancer and normal tissue were obtained, suggesting that the expression levels of these resistance factors are maintained during carcinogenesis in most patients.

Glutathione, glutathione S-transferase alpha and pi, and aldehyde dehydrogenase content in relationship to drug resistance in ovarian cancer

Glutathione, glutathione S-transferases alpha and pi, and aldehyde dehydrogenase are associated with resistance to carboplatin and/or cyclophosphamide in cell lines. Therefore, we examined whether the expression of these factors in ovarian cancer tissue specimens is associated with resistance of the patients to combination chemotherapy with cyclophosphamide/carboplatin. Ovarian cancer tissue specimens were taken intraoperatively from 139 patients and frozen in liquid nitrogen, and the contents of glutathione S-transferases alpha and pi, total glutathione, and aldehyde dehydrogenase activity were determined. No association between the levels of glutathione S-transferases alpha and pi or aldehyde dehydrogenase activity in tumor tissue and the survival time was observed in patients with primary ovarian cancer. Significantly higher levels of aldehyde dehydrogenase were observed in FIGO stage I and II compared to FIGO stage III and IV tumors (P = 0.019, Wilcoxon test, two sided). The median survival time was significantly longer in patients with primary ovarian cancer with a tumor glutathione content of <4.9 microg/mg protein compared to patients with a tumor glutathione content of > or =4.9 microg/mg protein (P = 0.047). However, glutathione was not an independent prognostic factor, but was significantly associated with FIGO stage resulting in higher levels in FIGO stage III and IV tumors than in FIGO stage I and II tumors (P = 0.0094, Wilcoxon test, two sided). In conclusion the glutathione content was associated with progression of ovarian carcinomas but neither glutathione nor glutathione S-transferases alpha and pi or aldehyde dehydrogenase were independent factors of resistance to cyclophosphamide/carboplatin.

Noninvasive assessment of regional cardiac adenosine using positron emission tomography

One of the early metabolic changes associated with myocardial ischemia is the breakdown of adenine nucleotides resulting in the enhanced production of adenosine. In order to image regional cardiac adenosine by positron emission tomography (PET) the enzymatic conversion of adenosine into [11C]-S-adenosylhomocysteine ([11C]SAH) was used in the presence of 11C-labeled homocysteine thiolactone (adenosine + [11C] - homocysteine-->[11C] - SAH + H2O). Following production of an experimental coronary constriction in anesthetized dogs carrier added 1-[11C]-D,L-homocysteine thiolactone (5-27 mCi, 30 mg/kg) was infused over 1 min. This intervention, while hemodynamically ineffective, increased the plasma homocysteine concentration from 2.5 to 306 microM, which thereafter declined with a T1/2 of 28 min to 97 microM after 60 min. During the first minutes following infusion of [11C] homocysteine, the radioactivity concentration in the blood pool, the nonischemic and the ischemic myocardium were similar. Between 20 and 60 min, however, the regional radioactivity concentration was highest in the perfusion area of the stenosed vessel: 6.6% compared to 5.2 and 5.2% of the injected dose per 1 I tissue. The elevated radioactivity concentration was strictly confined to the perfusion area of the occluded artery. Using [35S]-L-homocysteine (20 microCi; 30 mg/kg) chromatographic separation of SAH in tissue extracts confirmed that the radioactivity accumulation was due to trapping of adenosine in the cellular SAH-pool. These experiments provide first evidence that 1-[11C]homocysteine thiolactone can be successfully used to assess regional adenosine formation in the heart with PET via measurement of [11C] SAH accumulation.

Evidence for adenylate cyclase-coupled A1-adenosine receptors on ventricular cardiomyocytes from adult rat and dog heart

Isolated metabolically stable cardiomyocytes from adult rats and mongrel dogs were used to characterize the mechanism underlying the antiadrenergic effect of adenosine. In a system not affected by cellular heterogeneity, isoproterenol (3 x 10(-9) M - 10(-5) M) in the presence of adenosine deaminase (5U/ml) dose dependently increased cellular cAMP (5-80 pmol/mg). The effect of isoproterenol (0.1 microM) was inhibited by various adenosine derivatives, the rank order of potency being in the rat: (-)-N6-(R-phenyl-isopropyl)-adenosine (R-PIA) greater than 5'-N-ethylcarboxamidoadenosine (NECA) greater than S-PIA, and in the dog NECA greater than R-PIA greater than S-PIA. The cAMP increase induced by forskolin (1 microM) was attenuated in the rat by R-PIA. 8-phenyltheophylline (3 microM) antagonized the effect of R-PIA on isoproterenol-stimulated cAMP formation. Basal cAMP content was not influenced by R-PIA or NECA. Omission of adenosine deaminase from the incubation medium attenuated the isoproterenol-induced cAMP increase in the rat by about 30%. Our findings provide evidence for the presence of adenylate cyclase-coupled A1-adenosine receptors on cardiomyocytes which may mediate the antiadrenergic effect of adenosine in the heart.