[Safety of patient care on an interprofessional training ward in visceral surgery]

BACKGROUND

Interprofessional training wards (ITW) are increasingly being integrated into teaching and training concepts in visceral surgery clinics.

OBJECTIVE

How safe is patient care on an ITW in visceral surgery?

MATERIAL AND METHODS

Data collection took place from November 2021 to December 2022. In this nonrandomized prospective evaluation study the frequency and severity of adverse events (AE) in 3 groups of 100 patients each in a tertiary referral center hospital for visceral surgery were investigated. The groups consisted of patients on the ITW and on the conventional ward before and after implementation of the ITW. The Global Trigger Tool (GTT) was used to search for AE. Simultaneously, a survey of the treatment was conducted according to the Picker method to measure patient reported outcome.

RESULTS

Baseline characteristics and clinical outcome parameters of the patients in the three groups were comparable. The GTT analysis found 74 nonpreventable and 5 preventable AE in 63 (21%) of the patients and 12 AE occurred before the hospital stay. During the hospital stay 50 AE occurred in the operating theater and 17 on the conventional ward. None of the five preventable AE (in 1.7% of the patients) was caused by the treatment on the ITW. Patients rated the safety on the ITW better than in 90% of the hospitals included in the Picker benchmark cohort and as good as on the normal ward.

CONCLUSION

The GTT-based data as well as from the patients' point of view show that patient care on a carefully implemented ITW in visceral surgery is safe.

Oral health-related quality of life in patients with cleft lip and/or palate or Robin sequence

PURPOSE

To compare the oral health-related quality of life (OHRQoL) in patients with cleft lip and/or palate or Robin sequence versus a healthy control group using the Child Oral Health Impact Profile (COHIP-G19). Factors such as age, gender, and cleft type were considered.

METHODS

Over an 8-month period, the OHRQoL was surveyed by using the COHIP-G19 questionnaire. Included were patients with a craniofacial disorder (n = 61; average age 11.24 years) and a healthy control group (n = 70, average age 12.63 years) for a total of 131 patients (average age 11.99 years) from the Department of Orthodontics University Hospital Tübingen, Germany. These were divided into two age groups (6-11 years; 12-18 years).

RESULTS

Statistically, patients with a craniofacial disorder presented a significantly lower OHRQoL than the control group (p = 0.0055). In the craniofacial disorder group, older patients revealed a significantly (p = 0.005) lower OHRQoL than the younger patients. Female patients showed in nearly all groups a better OHRQoL than male patients, but this difference was not statistically significant (p > 0.05). Males with a craniofacial disorder scored significantly lower than males without (p = 0.016); females showed no differences between the groups. Visibility, location, and severity of the craniofacial malformation did not have a significant influence on the OHRQoL.

CONCLUSION

The occurrence of a craniofacial malformation impacted the OHRQoL especially in older and male affected patients, unrelated to the expression level or localization. An early instruction about oral health, rehabilitation and functional training should be considered in therapy.

Retrospective evaluation of the orthodontic treatment needs in primary school children with Robin sequence following Tübingen palatal plate therapy in infancy

INTRODUCTION

The aim of this study was to investigate the orthodontic treatment needs (OTN) of children with RS treated with the TPP in infancy compared to age- and sex-matched controls.

METHODS

The aim of this study was to investigate the orthodontic treatment needs (OTN) of children with RS treated with the TPP in infancy compared to age- and sex-matched controls.

RESULTS

In 21 children with RS (n = 23; 19 non-syndromic, 4 syndromic; average age 9.9 years) showed high OTN, which was significantly higher than in controls (n = 21). The latter of 9 controls had minor OTN, followed by 8 participants with borderline OTN. Regarding the intraoral picture, patients with RS had an increased open bite tendency. Without considering the presence of a cleft palate, 16 children with RS had high or very high OTN, compared to 4 of controls.

CONCLUSIONS

Patients with RS have significantly higher OTN than healthy controls, independent of cleft occurrence. RS is associated with dental anomalies and special skeletal growth patterns, both increasing malocclusion and negatively affecting dentoalveolar growth. This should raise awareness for identifying these needs and provide a comprehensive orthodontic treatment, where functional rehabilitation should be favored over aesthetic results.

Tooth agenesis in German orthodontic patients with non-syndromic craniofacial disorder: a retrospective evaluation of panoramic radiographs

Objectives

The study objective was to evaluate the tooth agenesis in German orthodontic patients with non-syndromic cleft lip and/or palate and Robin sequence compared to a control group without craniofacial disorder.

Materials/methods

A total of 108 panoramic radiographs were examined using the binary system of Tooth Agenesis Code (TAC) (excluding the third molar). Patients were divided into the craniofacial disorder group 1 (n = 43) and the healthy control group 2 (n = 65). Parameters such as skeletal class malformation, sex, localization of the cleft, craniofacial disorder, and interobserver reliability were assessed.

Results

Permanent tooth agenesis was observed in 44% of group 1 and 14% in group 2 with a statistically significant higher prevalence (p = 0.00162 (χ²)). Fourteen different TAC patterns were observed in group 1, ten of these occurring only once in separate patients. The distribution of the TAC codes in group 2 showed nine different possibilities of TAC code patterns; seven TACs were unique. In group 1, the most frequently absent teeth were the maxillary lateral incisor of the left side (30%); in group 2, the second premolar of the lower jaw on the right side (9%). Male patients with craniofacial disorder showed a higher percentage of tooth agenesis than female.

Conclusion

The data presented here shows a statistically significant higher prevalence of tooth agenesis in German patients with non-syndromic craniofacial disorder.

Clinical relevance

Radiographic evaluation enables the diagnosis of tooth agenesis. Recognizing early on the higher prevalence of tooth agenesis in patients exhibiting a craniofacial disorder is an important issue when developing long-term and comprehensive interdisciplinary treatment.

Technical note on introducing a digital workflow for newborns with craniofacial anomalies based on intraoral scans - part II: 3D printed Tübingen palatal plate prototype for newborns with Robin sequence

Background

Orthodontic treatment of newborns and infants with Robin-Sequence using the Tübingen Palatal Plate (TPP) is a complex procedure that could benefit from simplification through digitalization. The design of the velar extension (spur) and the palatal base determines the success of the treatment. Therefore, a prototype must be produced and inserted under endoscopic supervision in order to determine the appropriate shape, length and position of the spur. This technical note demonstrates a fully digital workflow for the design and manufacturing of a functional TPP prototype, based on an intraoral scan. This prototype can be altered and individualized digitally for each patient. After the shape and position of the spur have been optimized, the prototype is duplicated using a silicone mold. Then the definitive TPP is manufactured and inserted. We aim to present a workflow which facilitates the fitting procedure and does not require a conventional impression or a physical model to create the appliance.

Methods

As described in part I of this series, the intraoral scan is performed using the 3Shape TRIOS3 scanner and its corresponding acquisition software. The virtual model is rendered in the 3Shape ortho appliance designer and the base of the palatal plate is designed in the 3Shape dental designer. The palatal plate and the virtual model are then imported into Autodesk Meshmixer and a standardized spur is positioned and merged with the base. The TPP is exported in Standard Tessellation Language (STL) format and manufactured on a W2P Solflex 170 DLP printer using VOCO VPrint Splint material (MDR Class IIa).

Results

Based on an intraoral scan, the TPP prototype could be successfully manufactured and proved suitable for the patients’ treatment.

Conclusion

The new digital workflow for the design of the TPP can been successfully implemented into daily clinical routine in our facility. Patients could be alleviated from having to undergo conventional impression procedures and fitting of the TPP could be facilitated by producing multiple functional prototypes for endoscopic evaluation. Through rapid prototyping, the expenditure of the fitting process was reduced, which makes the TPP therapy more efficient and accessible to a wider range of clinicians.

Severe odontogenic infections with septic progress - a constant and increasing challenge: a retrospective analysis

Background

More than 90% of all infections in the head and neck region can be traced back to an odontogenic origin. In rare cases they can lead to sepsis, which may pose a vital threat to the patient. The purpose of this study was to analyse characteristics concerning etiology and progress of severe odontogenic infections with a fulminant development.

Methods

All patients with odontogenic infections requiring hospital admission were included in a retrospective analysis conducted from 02/2012 to 09/2017. Of 483 patients 16 patients (13 male, 3 female) showed severe exacerbation with septic progress. The average age was 52.8 years. All patients underwent at least one surgical procedure that involved an extraoral incision and drainage as well as high volume irrigation intraoperatively. At least one revision was required for four of the patients. Three patients showed an exceedingly severe disease progression with multiorgan dysfunction syndrome (MODS) and circulatory arrest. Antibiotic treatment was adjusted according to the results of an antibiogram and resistogram. Irrigation with saline was done several times a day.

Results

Sixteen patients showed odontogenic infections that spread over multiple maxillo-facial and cervical regions accompanied by septic laboratory signs. All these patients needed intensive care and a tracheostomy. The hospitalization period was 27.8 days on average. In 16 cases risk factors for the development of odontogenic abscesses like diabetes mellitus, obesity, chronic alcohol and nicotine abuse, rheumatism and poor oral hygiene were present. Intraoperative swabs showed a typical polymicrobial aerobic and anaerobic spectrum of oral bacteria, especially anaerobes and streptococci, mainly Streptocococcus viridans.

Conclusion

Odontogenic infections with fulminant progression should be treated based on clinical and imaging data with immediate surgical incision and drainage including elimination of odontogenic foci as well as intensified intra- and postoperative irrigation. If needed, repeat imaging followed by further incisions should be performed. Immediate antibiotic treatment adapted to the antibiogram is of utmost importance. A combination of tazobactam and piperacillin has proven to be a good first choice and can be recommended for abscesses that spread over multiple levels with initial signs of severe infections.

Termite soldiers contribute to social immunity by synthesizing potent oral secretions

The importance of soldiers to termite society defence has long been recognized, but the contribution of soldiers to other societal functions, such as colony immunity, is less well understood. We explore this issue by examining the role of soldiers in protecting nestmates against pathogen infection. Even though they are unable to engage in grooming behaviour, we find that the presence of soldiers of the Darwin termite, Mastotermes darwiniensis, significantly improves the survival of nestmates following entomopathogenic infection. We also show that the copious exocrine oral secretions produced by Darwin termite soldiers contain a high concentration of proteins involved in digestion, chemical biosynthesis, and immunity. The oral secretions produced by soldiers are sufficient to protect nestmates against infection, and they have potent inhibitory activity against a broad spectrum of microbes. Our findings support the view that soldiers may play an important role in colony immunity, and broaden our understanding of the possible function of soldiers during the origin of soldier-first societies.

Site-specific analysis of von Willebrand factor O-glycosylation

BACKGROUND

O-glycosylation of von Willebrand factor (VWF) affects many of its functions; however, there is currently no information on the occupancy of the 10 putative O-glycosylation sites.

OBJECTIVES

The aim of this study was the site-specific analysis of VWF O-glycosylation.

METHODS

Tryptic VWF-O-glycopeptides were isolated by lectin affinity chromatography and/or by reverse-phase high-performance liquid chromatography. Subsequently, the purified glycopeptides were analyzed by glycosidase digestion and mass spectrometry.

RESULTS

We found that all 10 predicted O-glycosylation sites in VWF are occupied. The majority of the glycan structures on all glycosylation sites is represented by disialyl core 1 O-glycan. The presence of core 2 O-glycan was also confirmed; interestingly, this structure was not evenly distributed among all 10 glycosylation sites. Analysis of the glycopeptides flanking the A1 domain revealed that generally more core-2-type O-glycan was present on the C-terminal Cluster 2 glycopeptide (encompassing T(1468) , T(1477) , S(1486) and T(1487) ) compared with the N-terminal Cluster 1 glycopeptide (encompassing T(1248) , T(1255) , T(1256) and S(1263) ). Disialosyl motifs were present on both glycopeptides flanking the A1 domain and on the glycosylation site T(2298) in the C1 domain. In addition, we identify sulfation of core 2 O-glycans and the presence of the rare Tn antigen.

CONCLUSIONS

This is the first study to describe the qualitative and semi-quantitative distribution of O-glycan structures on all 10 O-glycosylation sites, which will provide a valuable starting point for further studies exploring the functional and structural implications of O-glycosylation in VWF.

Impact of high dietary zinc on zinc accumulation, enzyme activity and proteomic profiles in the pancreas of piglets

The exocrine pancreas plays an important role in zinc homeostasis. Feeding very high (2000-3000mgzinc/kg diet) levels of zinc oxide to piglets for short periods is a common practice in the swine industry to improve performance and prevent diseases. The impact on pancreatic function and possible side effects during long-term feeding of high dietary zinc levels are still poorly understood. A total of 54 weaned piglets were either fed with low (57mg/kg, LZn), normal (164mg/kg, NZn) or high (2425mg/kg, HZn) zinc concentration in the diets. After 4 weeks of feeding, ten piglets per treatment were euthanized and pancreas samples were taken. Tissue zinc concentration and metallothionein abundance was greater with HZn compared with NZn and LZn (P<0.05). Similarly, activity of α-amylase, lipase, trypsin and chymotrypsin was higher with HZn as compared with NZn and LZn diets (P<0.05), whereas elastase activity was unchanged. Total trolox equivalent antioxidative capacity of pancreas tissue was higher with HZn diets compared with the other treatments (P<0.05). Pancreatic protein profiles of NZn and HZn fed piglets were obtained by 2D-DIGE technique and revealed 15 differentially expressed proteins out of 2100 detected spots (P<0.05). The differentially expressed proteins aldose reductase, eukaryotic elongation factor II and peroxiredoxin III were confirmed by immunoblotting. Identified proteins include zinc finger-containing transcription factors and proteins mainly associated with oxidative stress response and signal transduction in HZn compared with NZn pigs. Histologic examination however showed no morphologic changes. The results suggest that long-term supply of very high dietary zinc increases zinc and metallothionein concentration, and digestive enzyme activity, but also triggers oxidative stress reactions in the pancreas of young pigs. The data provide new insights into pancreatic function under outbalanced zinc homeostasis.

Endothelial barrier antigen-immunoreactivity is conversely associated with blood-brain barrier dysfunction after embolic stroke in rats

While the concept of the Neurovascular Unit (NVU) is increasingly considered for exploring mechanisms of tissue damage in ischemic stroke, immunohistochemical analyses are of interest to specifically visualize constituents like the endothelium. Changes in immunoreactivity have also been discussed to reflect functional aspects, e.g., the integrity of the blood-brain barrier (BBB). This study aimed to characterize the endothelial barrier antigen (EBA) as addressed by the antibody SMI-71 in a rat model of embolic stroke, considering FITC-albumin as BBB leakage marker and serum levels of BBB-associated matrix metalloproteinases (MMPs) to explore its functional significance. Five and 25 h after ischemia onset, regions with decreased BBB integrity exhibited a reduction in number and area of EBA-immunopositive vessels, while the stained area per vessel was not affected. Surprisingly, EBA content of remaining vessels tended to be increased in areas of BBB dysfunction. Analyses addressing this interrelation resulted in a significant and inverse correlation between the vessels’ EBA content and degree of BBB permeability. In conclusion, these data provide evidence for a functional relationship between EBA-immunoreactivity and BBB dysfunction in experimental ischemic stroke. Further studies are required to explore the underlying mechanisms of altered EBA-immunoreactivity, which might help to identify novel neuroprotective strategies.

Acute Cerebrovascular Disease in the Young

Background and Purpose—

Strokes have especially devastating implications if they occur early in life; however, only limited information exists on the characteristics of acute cerebrovascular disease in young adults. Although risk factors and manifestation of atherosclerosis are commonly associated with stroke in the elderly, recent data suggests different causes for stroke in the young. We initiated the prospective, multinational European study Stroke in Young Fabry Patients (sifap) to characterize a cohort of young stroke patients.

Methods—

Overall, 5023 patients aged 18 to 55 years with the diagnosis of ischemic stroke (3396), hemorrhagic stroke (271), transient ischemic attack (1071) were enrolled in 15 European countries and 47 centers between April 2007 and January 2010 undergoing a detailed, standardized, clinical, laboratory, and radiological protocol.

Results—

Median age in the overall cohort was 46 years. Definite Fabry disease was diagnosed in 0.5% (95% confidence interval, 0.4%–0.8%; n=27) of all patients; and probable Fabry disease in additional 18 patients. Males dominated the study population (2962/59%) whereas females outnumbered men (65.3%) among the youngest patients (18–24 years). About 80.5% of the patients had a first stroke. Silent infarcts on magnetic resonance imaging were seen in 20% of patients with a first-ever stroke, and in 11.4% of patients with transient ischemic attack and no history of a previous cerebrovascular event. The most common causes of ischemic stroke were large artery atherosclerosis (18.6%) and dissection (9.9%).

Conclusions—

Definite Fabry disease occurs in 0.5% and probable Fabry disease in further 0.4% of young stroke patients. Silent infarcts, white matter intensities, and classical risk factors were highly prevalent, emphasizing the need for new early preventive strategies.

Clinical Trial Registration Information—

URL: http://www.clinicaltrials.gov .Unique identifier: NCT00414583

Modification of the secondary structure of angiotensin II by substitution of hydrogen with Cs cations: an experimental and theoretical study

MALDI mass spectrometry in combination with post-source decay (PSD) analysis is a fast and easy to apply method for peptide sequencing. In this study, the PSD technique was used to investigate the influence of the adaption of one, two, and three caesium cations to angiotensin II in the gas phase. The PSD spectra of caesium-aggregated angiotensin II show far less fragmentation in comparison to the protonated one. In the case of singly (doubly) Cs(+) substituted angiotensin II, the PSD mass spectrum shows only fragments with one (two) Cs cation(s). These results are interpreted in terms of additional interactions of the caesium cation(s) with the peptide. In order to investigate this suggestion, the molecular structures were calculated with semi-empirical molecular dynamic (MD) simulations and further optimized at the quantum chemical level (BP86, SVP) of theory. On the one hand, secondary structures of Cs(+) substituted angiotensin II are more compact than the structure of protonated angiotensin II, indicating electrostatic interactions of the Cs cations and the heterocyclic structures. Moreover, oxyphilic interactions of the cations with the oxygen atoms of the peptide backbone also contribute as further van-der-Waals interactions of the Cs(+) substituted angiotensin II. These interactions are able to explain its higher stability due to reduced dissociation in comparison to the protonated angiotensin II. On the other hand, most MD simulations of doubly and triply Cs(+) substituted angiotensin II show a formation of a [2 Cs] cluster, surrounded by the peptide molecule. The formation of this cluster would explain the lack of singly Cs(+) substituted fragments in the PSD mass spectrum of doubly Cs(+) substituted angiotensin II.

Differences in the proteome of high-grade versus low-grade canine cutaneous mast cell tumours

Cutaneous mast cell tumours (MCTs) are the most common skin tumours in dogs. However, the molecular differences between benign tumours with a good prognosis and highly malignant, invasive and metastatic tumours with short survival times are for the most part unclear. In the present study the proteome of low-grade MCTs with a good prognosis was compared with that of poor-prognosis high-grade tumours independent of their mutational status of exon 11 of the KIT gene. Using two-dimensional difference gel electrophoresis and mass spectrometry, 13 proteins with a significant differential expression between the two groups were identified. Four stress response proteins (HSPA9, PDIA3, TCP1A and TCP1E) were significantly up-regulated in high-grade tumours, while proteins mainly associated with cell motility and metastasis had either increased (WDR1, ACTR3, ANXA6) or decreased (ANXA2, ACTB) expression levels. High-grade tumours also had a paradox down-regulation of transferrin, a protein that is usually up-regulated in neoplastic cells. The histologically observable dedifferentiation of high-grade tumours was reflected by decreased tryptase protein expression levels. Results of quantitative real-time RT-PCR analysis indicated that the differences in protein expression levels of most proteins were regulated at the transcript level. Based on these findings, it is hypothesized that high-grade MCT cells have a higher resistance to cellular stress and thus are able to better cope with the adverse environment in highly proliferating tumours independent of increased KIT signalling. It is noteworthy that some of the proteins identified have been proposed as therapeutic targets for human oncology and it will be interesting to evaluate their therapeutic and diagnostic potential for canine MCTs.

Lipophorin of lower density is formed during immune responses in the lepidopteran insect Galleria mellonella

Injection of heat-killed bacteria into larvae of the greater wax moth Galleria mellonella is followed by changes in lipoprotein composition in the hemolymph. Density gradient centrifugation experiments revealed that within the first four hours after injection, a part of larval lipoprotein, high-density lipophorin (HDLp), was converted into a lipoprotein of lower density. SDS-polyacrylamide gel electrophoresis analysis of the gradient fractions and sequencing of protein fragments, established that the exchangeable apolipoprotein apolipophorin III (apoLp-III), a potent immune-activator, was associated with this newly formed lipophorin. To investigate further the influence of lipophorin-associated apoLp-III on immune-related reactions, we performed in vitro studies with isolated hemocytes from G. mellonella and lipophorins from the sphinx moth Manduca sexta, as a natural source of high amounts of low-density lipophorin (LDLp) and HDLp. The hemocytes were activated to form superoxide radicals upon incubation with LDLp, but not with HDLp. Fluorescence-labeled LDLp was specifically taken up by granular cells. This process was inhibited by adding an excess of unlabeled LDLp, but not by HDLp. We hypothesize that larval lipophorin formed in vivo is an endogenous signal for immune activation, specifically mediated by the binding of lipid-associated apoLp-III to hemocyte membrane receptors.

Synaptic scaffolding proteins in rat brain. Ankyrin repeats of the multidomain Shank protein family interact with the cytoskeletal protein alpha-fodrin

The postsynaptic density is the ultrastructural entity containing the neurotransmitter reception apparatus of excitatory synapses in the brain. A recently identified family of multidomain proteins termed Src homology 3 domain and ankyrin repeat-containing (Shank), also known as proline-rich synapse-associated protein/somatostatin receptor-interacting protein, plays a central role in organizing the subsynaptic scaffold by interacting with several synaptic proteins including the glutamate receptors. We used the N-terminal ankyrin repeats of Shank1 and -3 to search for interacting proteins by yeast two-hybrid screening and by affinity chromatography. By cDNA sequencing and mass spectrometry the cytoskeletal protein alpha-fodrin was identified as an interacting molecule. The interaction was verified by pull-down assays and by coimmunoprecipitation experiments from transfected cells and brain extracts. Mapping of the interacting domains of alpha-fodrin revealed that the highly conserved spectrin repeat 21 is sufficient to bind to the ankyrin repeats. Both interacting partners are coexpressed widely in the rat brain and are colocalized in synapses of hippocampal cultures. Our data indicate that the Shank1 and -3 family members provide multiple independent connections between synaptic glutamate receptor complexes and the cytoskeleton.

Experimental and clinical evaluation of the PARIS centering catheter for delivery of endovascular gamma-irradiation of femoropopliteal stenoses

PURPOSE

To investigate the effect of aortic bifurcation and iliac geometry on centered endovascular irradiation (CEI) of femoropopliteal arteries and evaluate procedure-related complications.

MATERIALS AND METHODS

In an experimental tubing model, crossover delivery of the dummy wire by an afterloader using different sheaths (Type I: noncrossover; Type II: crossover, length 40 cm; Type III: crossover, length 65 cm) was examined at simulated angles between 20 degrees -100 degrees (aortic bifurcation) and 0 degrees -100 degrees (iliac vessels). In the clinical phase, 28 heparin-anticoagulated patients underwent percutaneous transluminal angioplasty (PTA) for femoropopliteal stenoses followed by CEI (192-iridium, 14 Gray at 2 mm depth of the vessel wall) delivered with the centering catheter (crossover from contralateral leg using a 65-cm-long 8F sheath in 13 patients, noncrossover from ipsilateral leg using a 10-cm 8F sheath in 15 patients). Measurement of the aortic bifurcation angle before advancement of the crossover sheath and rating of iliac artery tortuosity on both sides was retrospectively performed on angiograms. Fifteen controls received no post-PTA CEI.

RESULTS

Experimental delivery of the dummy wire was not possible at aortic angles less than 40 degrees with Type I, 60 degrees with Type II, and 30 degrees with Type III sheaths. Advancement of the centering catheter was possible in all patients. CEI failed in two patients with crossover (aortic angle <40 degrees ) and in one obese patient with antegrade approach because advancement of the dummy wire was impossible. Thromboembolism rate was 4.6% during irradiation (2.3% after PTA alone).

CONCLUSIONS

CEI in femoropopliteal arteries has a risk of procedure-related thromboembolic complications. Efficacy is affected by vessel geometry.

The Brucella suis homologue of the Agrobacterium tumefaciens chromosomal virulence operon chvE is essential for sugar utilization but not for survival in macrophages

Brucella strains possess an operon encoding type IV secretion machinery very similar to that coded by the Agrobacterium tumefaciens virB operon. Here we describe cloning of the Brucella suis homologue of the chvE-gguA-gguB operon of A. tumefaciens and characterize the sugar binding protein ChvE (78% identity), which in A. tumefaciens is involved in virulence gene expression. B. suis chvE is upstream of the putative sugar transporter-encoding genes gguA and gguB, also present in A. tumefaciens, but not adjacent to that of a LysR-type transcription regulator. Although results of Southern hybridization experiments suggested that the gene is present in all Brucella strains, the ChvE protein was detected only in B. suis and Brucella canis with A. tumefaciens ChvE-specific antisera, suggesting that chvE genes are differently expressed in different Brucella species. Analysis of cell growth of B. suis and of its chvE or gguA mutants in different media revealed that ChvE exhibited a sugar specificity similar to that of its A. tumefaciens homologue and that both ChvE and GguA were necessary for utilization of these sugars. Murine or human macrophage infections with B. suis chvE and gguA mutants resulted in multiplication similar to that of the wild-type strain, suggesting that virB expression was unaffected. These data indicate that the ChvE and GguA homologous proteins of B. suis are essential for the utilization of certain sugars but are not necessary for survival and replication inside macrophages.

First tryptophan-containing weak neurotoxin from cobra venom

With the purpose of studying structure-function relationships among weak neurotoxins (called so because of their low toxicity), we have isolated a toxin (WTX) from the venom of cobra Naja kaouthia using a combination of gel-filtration and ion-exchange chromatography. The amino acid sequence of the isolated toxin was determined by means of Edman degradation and MALDI mass spectrometry, the primary structure obtained being confirmed by 1H-NMR in the course of spatial structure analysis. The WTX sequence differs slightly from that of the toxin CM-9a isolated earlier from the same venom (Joubert and Taljaard, Hoppe-Seyler's Z. Physiol. Chem., 361 (1980) 425). The differences include an extra residue (Trp36) between Ser35 and Arg37 as well as interchanging of two residues (Tyr52 and Lys50) in the C-terminal part of the toxin molecule. These changes improve the alignment that can be made with other weak neurotoxin sequences. An extended sequence comparison reveals that WTX is the first case of a tryptophan-containing weak neurotoxin isolated from cobra venom. WTX was found to compete with radioiodinated alpha-bungarotoxin for binding to the membrane-bound nicotinic acetylcholine receptor from Torpedo californica.

[Cobra venom contains a protein belongs to the CRISP family]

Amino acid sequences of several fragments of the 25 k protein (molecular mass 24,953 Da) previously isolated from cobra Naja kaouthia (Kukhtina et al. Bioorg. Khim., 2000, vol. 26, pp. 803-807) were determined. Their comparison with the primary structures of known proteins showed that the 25 k protein belongs to the CRISP family and is the first protein of this type identified in cobra venoms.

Characterization of recombinant human nicotinamide mononucleotide adenylyl transferase (NMNAT), a nuclear enzyme essential for NAD synthesis

Nicotinamide mononucleotide adenylyl transferase (NMNAT) is an essential enzyme in all organisms, because it catalyzes a key step of NAD synthesis. However, little is known about the structure and regulation of this enzyme. In this study we established the primary structure of human NMNAT. The human sequence represents the first report of the primary structure of this enzyme for an organism higher than yeast. The enzyme was purified from human placenta and internal peptide sequences determined. Analysis of human DNA sequence data then permitted the cloning of a cDNA encoding this enzyme. Recombinant NMNAT exhibited catalytic properties similar to the originally purified enzyme. Human NMNAT (molecular weight 31932) consists of 279 amino acids and exhibits substantial structural differences to the enzymes from lower organisms. A putative nuclear localization signal was confirmed by immunofluorescence studies. NMNAT strongly inhibited recombinant human poly(ADP-ribose) polymerase 1, however, NMNAT was not modified by poly(ADP-ribose). NMNAT appears to be a substrate of nuclear kinases and contains at least three potential phosphorylation sites. Endogenous and recombinant NMNAT were phosphorylated in nuclear extracts in the presence of [gamma-(32)P]ATP. We propose that NMNAT's activity or interaction with nuclear proteins are likely to be modulated by phosphorylation.

Location of the polyamine binding site in the vestibule of the nicotinic acetylcholine receptor ion channel

To map the structure of a ligand-gated ion channel, we used the photolabile polyamine-containing toxin MR44 as photoaffinity label. MR44 binds with high affinity to the nicotinic acetylcholine receptor in its closed channel conformation. The binding stoichiometry was two molecules of MR44 per receptor monomer. Upon UV irradiation of the receptor-ligand complex, (125)I-MR44 was incorporated into the receptor alpha-subunit. From proteolytic mapping studies, we conclude that the site of (125)I-MR44 cross-linking is contained in the sequence alpha His-186 to alpha Leu-199, which is part of the extracellular domain of the receptor. This sequence partially overlaps in its C-terminal region with one of the three loops that form the agonist-binding site. The agonist carbachol and the competitive antagonist alpha-bungarotoxin had only minor influence on the photocross-linking of (125)I-MR44. The site where the hydrophobic head group of (125)I-MR44 binds must therefore be located outside the zone that is sterically influenced by agonist bound at the nicotinic acetylcholine receptor. In binding and photocross-linking experiments, the luminal noncompetitive inhibitors ethidium and triphenylmethylphosphonium were found to compete with (125)I-MR44. We conclude that the polyamine moiety of (125)I-MR44 interacts with the high affinity noncompetitive inhibitor site deep in the channel of the nicotinic acetylcholine receptor, while the aromatic ring of this compound binds in the upper part of the ion channel (i.e. in the vestibule) to a hydrophobic region on the alpha-subunit that is located in close proximity to the agonist binding site. The region of the alpha-subunit labeled by (125)I-MR44 should therefore be accessible from the luminal side of the vestibule.

Binding of polyamine-containing toxins in the vestibule of the nicotinic acetylcholine receptor ion channel

Several wasp venoms contain philanthotoxins (PhTXs) that act as noncompetitive inhibitors (NCIs) on cation-selective ion channels including the nicotinic acetylcholine receptor (nAChR). In the search for a ligand with high affinity and specificity for the nAChR we tested a series of newly developed PhTX analogues. Modulation of the structural elements of PhTXs can significantly influence their binding affinities. This approach resulted in the development of the photolabile compound MR44. In photoaffinity labelling studies 125I-MR44 was used to map the ligand-binding site at the Torpedo californica nAChR. Upon UV irradiation of the receptor-ligand complex, 125I-MR44 was mainly incorporated into the receptor alpha-subunit. Proteolytic mapping and microsequencing identified the site of 125I-MR44 cross-linking within the sequence alphaHis-186 to alphaLeu-199 that in its C-terminal region partially overlaps with the agonist-binding site. Since bound agonists had only minor influence on 125I-MR44 photocrosslinking, the site where the hydrophobic head group of 125I-MR44 binds must be located outside the zone that is sterically influenced by agonists bound at the nAChR. A possible site of interaction of 125I-MR44 would be the N-terminal region of the labelled sequence, in which aromatic amino-acid residues are accumulated. We suggest that the polyamine moiety of 125I-MR44 interacts with the high affinity non-competitive inhibitor site deep in the ion channel, while the aromatic ring of this compound binds in the vestibule of the nAChR to a hydrophobic region on the alpha-subunit that is located close to the agonist binding site.

Muscarinic toxin-like proteins from cobra venom

Three new polypeptides were isolated from the venom of the Thailand cobra Naja kaouthia and their amino-acid sequences determined. They consist of 65-amino-acid residues and have four disulfide bridges. A comparison of the amino-acid sequences of the new polypeptides with those of snake toxins shows that two of them (MTLP-1 and MTLP-2) share a high degree of similarity (55-74% sequence identity) with muscarinic toxins from the mamba. The third polypeptide (MTLP-3) is similar to muscarinic toxins with respect to the position of cysteine residues and the size of the disulfide-confined loops, but shows less similarity to these toxins (30-34% sequence identity). It is almost identical with a neurotoxin-like protein from Bungarus multicinctus (TrEMBL accession number Q9W727), the sequence of which has been deduced from cloned cDNA only. The binding affinities of the isolated muscarinic toxin-like proteins towards the different muscarinic acetylcholine receptor (mAChR) subtypes (m1-m5) was determined in competition experiments with N-[3H]methylscopolamine using membrane preparations from CHO-K1 cells, which express these receptors. We found that MTLP-1 competed weakly with radioactive ligand for binding to all mAChR subtypes. The most pronounced effect was observed for the m3 subtype; here an IC50 value of about 3 microM was determined. MTLP-2 had no effect on ligand binding to any of the mAChR subtypes at concentrations up to 1 microM. MTLP-1 showed no inhibitory effect on alpha-cobratoxin binding to the nicotinic acetylcholine receptor from Torpedo californica at concentrations up to 20 microM.

CREB-binding protein/p300 activates MyoD by acetylation

The myogenic protein MyoD requires two nuclear histone acetyltransferases, CREB-binding protein (CBP)/p300 and PCAF, to transactivate muscle promoters. MyoD is acetylated by PCAF in vitro, which seems to increase its affinity for DNA. We here show that MyoD is constitutively acetylated in muscle cells. In vitro, MyoD is acetylated both by CBP/p300 and by PCAF on two lysines located at the boundary of the DNA binding domain. MyoD acetylation by CBP/p300 (as well as by PCAF) increases its activity on a muscle-specific promoter, as assessed by microinjection experiments. MyoD mutants that cannot be acetylated in vitro are not activated in the functional assay. Our results provide direct evidence that MyoD acetylation functionally activates the protein and show that both PCAF and CBP/p300 are candidate enzymes for MyoD acetylation in vivo.

Characterization of an alpha-macroglobulin-like glycoprotein isolated from the plasma of the soft tick Ornithodoros moubata

We report the identification of the first representative of the alpha-2-macroglobulin family identified in terrestrial invertebrates. An abundant acidic glycoprotein was isolated from the plasma of the soft tick Ornithodoros moubata. Its molecular mass is about 420 kDa in the native state, whereas in SDS/PAGE it migrates as one band of 190 kDa under nonreducing conditions and a band of 92 kDa when reduced. Chemical deglycosylation reveals that it is composed of two different subunits, designated A and B. The N-terminal amino-acid sequence of subunit A is similar to the N-terminus of invertebrate alpha-2-macroglobulin. Sequence analysis of several internal peptides confirms that the tick protein belongs to the alpha-2-macroglobulin family, and the protein is therefore referred to as tick alpha-macroglobulin (TAM). Functional analyses strengthen this assignment. TAM inhibits trypsin and thermolysin cleavage of the high-molecular-weight substrate azocoll in a manner similar to that of bovine alpha-2-macroglobulin. This effect is abolished by pre-treatment of TAM with methylamine. In the presence of TAM, trypsin is protected against active-site inhibition by soybean trypsin inhibitor. We cloned and sequenced a PCR product containing sequences from both subunits and spanning the N-terminus of subunit B and the putative 'bait region' (a segment of alpha-2-macroglobulin which serves as target for various proteases). This indicates that the two subunits are generated from a precursor polypeptide by post-translational processing.

Purification and characterization of the lysozyme from the gut of the soft tick Ornithodoros moubata

The gut of the adult soft ticks Ornithodoros moubata displays high lytic activity against the bacteria Micrococcus luteus. The activity differed in the range of two orders of magnitude among individual animals and increased on average 4 fold during the first week following ingestion. In homogenates of first instar nymphs the activity was much lower increasing exponentially as nymphs neared the first molt. The protein responsible for this activity was purified out of gut contents of adult ticks by means of affinity adsorption on magnetic-chitin followed by two chromatography steps on cation exchange FPLC column MonoS. The homogeneous active protein has a mass of 14006 +/- 20 Daltons as determined by MALDI-TOF mass spectrometry. The N-terminal amino-acid sequence of this protein is K-V-Y-D-R-C-S-L-A-S-E-L-R with the highest similarity to the lysozyme from liver of rainbow trout and to lysozymes from digestive tracts of several mammals. The motif DRCSLA is specific for the digestive lysozymes of several dipteran insects. Based on this evidence, we have identified the protein as the tick gut lysozyme. The tick gut lysozyme has a pI near 9.7 and retains its full activity after treatment at 60 degrees C for 30 minutes. The pH optimum of the tick lysozyme was in the range from pH 5-7. Only marginal activity could be detected at pH > 8 which raises the question about the function of lysozyme in anti-bacterial defense in the environment of the tick gut.

Reverse physiology in drosophila: identification of a novel allatostatin-like neuropeptide and its cognate receptor structurally related to the mammalian somatostatin/galanin/opioid receptor family

By using degenerate oligonucleotide primers deduced from the conserved regions of the mammalian somatostatin receptors, a novel G-protein-coupled receptor from Drosophila melanogaster has been isolated exhibiting structural similarities to mammalian somatostatin/galanin/opioid receptors. To identify the bioactive ligand, a 'reverse physiology' strategy was used whereby orphan Drosophila receptor-expressing frog oocytes were screened against potential ligands. Agonistic activity was electrophysiologically recorded as inward potassium currents mediated through co-expressed G-protein-gated inwardly rectifying potassium channels (GIRK). Using this approach a novel peptide was purified from Drosophila head extracts. Mass spectrometry revealed an octapeptide of 925 Da with a sequence Ser-Arg-Pro-Tyr-Ser-Phe-Gly-Leu-NH(2) reminiscent of insect allatostatin peptides known to control diverse functions such as juvenile hormone synthesis during metamorphosis or visceral muscle contractions. Picomolar concentrations of the synthesized octapeptide activated the cognate receptor response mediated through GIRK1, indicating that we have isolated the 394-amino-acid Drosophila allatostatin receptor which is coupled to the Gi/Go class of G proteins.

Biochemical analysis of SopE from Salmonella typhimurium, a highly efficient guanosine nucleotide exchange factor for RhoGTPases

RhoGTPases are key regulators of eukaryotic cell physiology. The bacterial enteropathogen Salmonella typhimurium modulates host cell physiology by translocating specific toxins into the cytoplasm of host cells that induce responses such as apoptotic cell death in macrophages, the production of proinflammatory cytokines, the rearrangement of the host cell actin cytoskeleton (membrane ruffling), and bacterial entry into host cells. One of the translocated toxins is SopE, which has been shown to bind to RhoGTPases of the host cell and to activate RhoGTPase signaling. SopE is sufficient to induce profuse membrane ruffling in Cos cells and to facilitate efficient bacterial internalization. We show here that SopE belongs to a novel class of bacterial toxins that modulate RhoGTPase function by transient interaction. Surface plasmon resonance measurements revealed that the kinetics of formation and dissociation of the SopE.CDC42 complex are in the same order of magnitude as those described for complex formation of GTPases of the Ras superfamily with their cognate guanine nucleotide exchange factors (GEFs). In the presence of excess GDP, dissociation of the SopE.CDC42 complex was accelerated more than 1000-fold. SopE-mediated guanine nucleotide exchange was very efficient (e.g. exchange rates almost 10(5)-fold above the level of the uncatalyzed reaction; substrate affinity), and the kinetic constants were similar to those described for guanine nucleotide exchange mediated by CDC25 or RCC1. Far-UV CD spectroscopy revealed that SopE has a high content of alpha-helical structure, a feature also found in Dbl homology domains, Sec7-like domains, and the Ras-GEF domain of Sos. Despite the lack of any obvious sequence similarity, our data suggest that SopE may closely mimic eukaryotic GEFs.

Identification of melanin concentrating hormone (MCH) as the natural ligand for the orphan somatostatin-like receptor 1 (SLC-1)

To identify possible ligands of the orphan somatostatin-like receptor 1 (SLC-1), rat brain extracts were analyzed by using the functional expression system of Xenopus oocytes injected with cRNAs encoding SLC-1 and G protein-gated inwardly rectifying potassium channels (GIRK). A strong inward current was observed with crude rat brain extracts which upon further purification by cation exchange chromatography and high performance liquid chromatography (HPLC) yielded two peptides with a high agonist activity. Mass spectrometry and partial peptide sequencing revealed that one peptide is identical with the neuropeptide melanin concentrating hormone (MCH), the other represents a truncated version of MCH lacking the three N-terminal amino acid residues. Xenopus oocytes expressing the MCH receptor responded to nM concentrations of synthetic MCH not only by the activation of GIRK-mediated currents but also by the induction of Ca(2+) dependent chloride currents mediated by phospholipase C. This indicates that the MCH receptor can couple either to the G(i)- or G(q)-mediated signal transduction pathway, suggesting that MCH may serve for a number of distinct brain functions including food uptake behavior.

Insect immune activation by recombinant Galleria mellonella apolipophorin III(1)

Apolipophorin III (apoLp-III) is an exchangeable insect apolipoprotein. Its function, as currently understood, lies in the stabilization of low-density lipophorin particles (LDLp) crossing the hemocoel in phases of high energy consumption to deliver lipids from the fat body to the flight muscle cells. Recent studies with native Galleria mellonella-apoLp-III gave first indications of an unexpected role of that protein in insect immune activation. Here we report the immune activation by the recombinant protein, documenting a newly discovered correlation between lipid physiology and immune defense in insects. The complete cDNA sequence of G. mellonella-apoLp-III was identified by mixed oligonucleotide-primed amplification of cDNA (MOPAC), 3'-RACE-PCR, and cRACE-PCR. The sequence coding for the native protein was ligated into a pET-vector; this construct was transfected into Escherichia coli and overexpressed in the bacteria. Photometric turbidity assays with human low density lipoprotein (LDL) and transmission electron microscopy studies on apoLp-III-stabilized lipid discs revealed the full functionality of the isolated recombinant apoLp-III with regard to its lipid-association ability. For proving its immune-stimulating capacity, apoLp-III was injected into the hemocoel of last instar G. mellonella larvae and the antibacterial activity in cell-free hemolymph was determined 24 h later. As a result, the hemolymph samples of injected insects contained strongly increased antibacterial activities against E. coli as well as clearly enhanced lysozyme-like activities. From Northern blot analysis of total RNA from insects injected with apoLp-III or the bacterial immune provocator lipopolysaccharide, it could be concluded that the transcription rate of apoLp-III mRNA does not vary in comparison to untreated last instar larvae.

Seroprevalence and disease association of antineutrophil cytoplasmic autoantibodies and antigens in HIV infection

This prospective study was designed to determine the role of antineutrophil cytoplasmic autoantibodies (ANCA) in HIV-infected patients. Immunofluorescence tests (IFT) and enzyme-linked immunosorbent assays (ELISA) were applied to sera of 199 consecutive outpatients. In the IFT 20% were positive. An atypical ANCA pattern was demonstrated in 67% of these, 33% revealed a perinuclear staining (pANCA). Specific ELISA revealed proteinase 3 (n = 2), myeloperoxidase (n = 1), lysozyme (n = 2), lactoferrin (n = 1), cathepsin G (n = 1), and human leukocyte elastase (HLE, n = 6). The target antigen remained unidentified in 26 patients. Perinuclear ANCA-positive patients showed atypical antigens in eight of 13 cases; all six patients with anti-HLE revealed a pANCA pattern. The antigens of atypical ANCA-positive patients remained unidentified in 21 of 26 (81%) cases. No signs of vasculitis were present in the ANCA-positive patients. ANCA are frequently found in the sera of HIV-positive patients. They bind to a variety of antigens. No correlation was found between ANCA positivity and autoimmune or opportunistic diseases.

Butyrylcholinesterase is complexed with transferrin in chicken serum

The function of the enzyme butyrylcholinesterase (BChE) both in serum and in brain is unclear. In serum, BChE has been found complexed with several biomedically relevant proteins, with which it could function in concert. Here, the existence of a similar complex formed between BChE and sero-transferrin from adult chicken serum was elucidated. In order to identify both proteins unequivocally, we improved methods to highly purify the 81-kDa BChE and the coisolated 75-kDa transferrin, which then allowed us to tryptically digest and sequence the resulting peptides. The sequences as revealed for BChE peptides were highly identical to mammalian BChEs. A tight complex formation between the two proteins could be established (a) since transferrin is coisolated along with BChE over three steps including procainamide affinity chromatography, while transferrin alone is not bound to this affinity column, and (b) since imunoprecipitation experiments of whole serum with a transferrin-specific antiserum allows us to detect BChE in the precipitate with the BChE-specific monoclonal antibody 7D11. The possible biomedical implications of a complex between transferrin and BChE which here has been shown to exist in chicken serum are briefly discussed.

Primary structure of apolipophorin-III from the greater wax moth, Galleria mellonella

The complete amino acid sequence of apolipophorin-III (apoLp-III), a lipid-binding hemolymph protein from the greater wax moth, Galleria mellonella, was determined by protein sequencing. The mature protein consists of 163 amino acid residues forming a protein of 18,075.5 Da. Its sequence is similar to apoLp-III from other Lepidopteran species, but remarkably different from the apoLp-IIIs of insects from other orders. As shown by mass spectrometric analysis, the protein carries no modifications. Thus, all of its known physiological functions, including its recently discovered immune response-stimulating activity, must reside in the protein itself.

Purification and characterization of an inducible metalloprotease inhibitor from the hemolymph of greater wax moth larvae, Galleria mellonella

In this paper, we report the detection, purification and characterization of the first metalloprotease inhibitor (IMPI) from invertebrates. IMPI was purified from the hemolymph of last-instar larvae of Galleria mellonella by precipitation with trichloroacetic acid and heat followed by affinity chromatography on a thermolysin-Sepharose column and gel filtration or reverse-phase high-performance liquid chromatography. For the detection of inhibitor activity, a new azocoll assay was established. IMPI was only detectable in larvae that had been injected with bacterial or fungal provocators, suggesting that it is induced nonspecifically during the humoral immune response. Injection of larvae with IMPI rendered them resistant to thermolysin, in quantities that normally would be lethal for them. IMPI was shown to be specific for metalloproteases. The molecular mass of IMPI was determined by mass spectrometry to be 8360 Da. Purified IMPI was heterogeneous, owing to different degrees of glycosylation with hexose/hexosamine and deoxyhexose residues. Ten cysteine residues were found in the molecule, and these are presumed to form five disulfide bridges. The amino terminus was blocked, but a partial amino-acid sequence starting from the thermolysin cleavage site was determined; this sequence exhibited no similarity with other known proteins, suggesting that the IMPI represents a new type of protease inhibitor.

Sertraline in the treatment of panic disorder. A multi-site, double-blind, placebo-controlled, fixed-dose investigation

BACKGROUND

This study compared the efficacy and safety of sertraline to placebo in treating panic disorder.

METHOD

178 out-patients with panic disorder who exhibited at least four panic attacks during the four weeks prior to screening and three during the two weeks of lead-in were randomly assigned to 12 weeks of double-blind treatment with sertraline (50, 100 or 200 mg) or placebo.

RESULTS

Sertraline was superior to placebo in reducing the number of panic attacks, situational attacks, unexpected attacks, limited symptom attacks, and time spent worrying (all P < 0.01) and the Hamilton Anxiety Scale (P < 0.05), although Clinical Global Impression (Improvement) did not significantly differentiate groups at 12 weeks and at end-point. No serious adverse events were associated with sertraline. No dose relationship was found for adverse events; overall drop-out rates were not different for sertraline or placebo, although more sertraline-treated subjects discontinued for adverse events, typically early in the study. Only dry mouth and ejaculation failure (primarily ejaculation delay) were associated significantly with sertraline.

CONCLUSIONS

Sertraline was effective and safe in reducing panic attacks. Higher doses were no more effective than the 50 mg dose.