Distribution of saa gene variants in verocytotoxigenic Escherichia coli isolated from cattle and food

The pathogenesis of verocytotoxigenic Escherichia coli (VTEC) infection in humans is multifactorial, given that verocytotoxins are the principal virulence factor. Most strains causing serious diseases possess the eae gene that encodes the adhesin intimin, but its presence is not essential for virulence as some cases are caused by eae-negative strains. An autoagglutinating adhesin designated Saa was found in some eae-negative strains. This protein varies in size as a consequence of variation in the number of copies of a 37-aa repeat unit in the C-terminal region. Based on these findings, we designed PCR primers to amplify the region coding for these differences to detect saa gene variants present in VTEC strains isolated in Argentina from cattle and meat. The gene saa was detected in 36 (31.6%) eae-negative strains and 5 variants were found. Strains isolated from cattle possessed 4 saa variants, whereas 2 variants were present in isolates from meat. Saa variant 1 predominated (18 strains) and was distributed in strains isolated both from cattle and from meat. Our study revealed the existence of two novel saa variants, termed 4 and 5, which have a higher number of 111-bp repeats than saa genes previously studied.

Do predictive mechanisms improve the angular vestibulo-ocular reflex in vestibular neuritis?

Recovery from vestibular neuritis (VN) is often incomplete which leads to persistent vestibular imbalance during rapid head movements. Patients with unilateral vestibular lesions have a larger gain of the horizontal vestibulo-ocular reflex during active compared to passive head movements. To test whether this gain increase is related to predictive mechanisms we studied 15 patients with VN and 14 control subjects during predictable and unpredictable passive horizontal head impulses in the light and darkness. The vestibulo-ocular reflex showed a significantly shorter latency and higher gain in the light for predictable head impulses towards the ipsilesional side. However, this effect is small and might contribute but cannot exclusively account for the gain increase during active head movements.

Rat enamel contains RP59: a new context for a protein from osteogenic and haematopoietic precursor cells

We have recently identified a protein, RP59, in bone marrow cells and young osteoblasts, in cells involved in bone repair and in young erythroblasts and megakaryocytes. Here, we report immunohistochemical data at the light- and electron-microscope level indicating that RP59 is also present in newly secreted tooth enamel of the rat and in ameloblasts, the formative cells. In enamel matrix, RP59 was located proximal to secretory ameloblasts only, i.e. in newly secreted material. Distal enamel and enamel in association with maturation stage ameloblasts were unlabelled. Secretory ameloblasts contained RP59 in the matrix-proximal region including Tomes' processes, post-secretory ameloblasts in the cell-matrix interface. Western blotting of proteins from tooth germs identified RP59 as a band at 90 kD, co-migrating with RP59 from bone marrow and spleen. Antisera versus a chemically synthesised RP59 peptide and versus a bacteria-synthesised protein fragment reacted in the same manner. In situ hybridisation of tooth tissue revealed RP59 RNA specifically in ameloblasts. The reverse transcription/polymerase chain reaction method identified tooth RNA coding for RP59. Sequence analysis indicated that RP59 RNA from tooth and marrow had the same sequence. An internal sequence motif was found in rat RP59 resembling a signal implicated in secretion of the chicken "engrailed" gene product. The findings indicate that RP59 is a genuine product of ameloblasts and that it is secreted in the course of enamel formation together with other matrix components.

[AWMF-guideline: cocaine-, amphetamine-, ecstasy- and hallucinogen-related disorders]

Actually, guidelines for treatment of substance-related disorders were written under the overall control of the DG-Sucht e. V. and the DGPPN e. V. This appears within the framework of the Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaft (AWMF). The leading objective of these guidelines is the description of the current scientifically proven and evidence-based medicine in addiction to derive recommendations to therapy. In this context, the guideline for treatment of cocaine-, amphetamine-, ecstasy-, and halluzinogen-related disorders is introduced.

[Differences between anteroposterior and posterior spondylodesis in clinical scores]

The present study on spondylitis patients was carried out to compare prospectively results of clinical scores of patients treated with anteroposterior or anterior spondylodesis. A total of 22 patients with spondylitis were enrolled in the randomized trial to undergo an operation with anteroposterior or posterior spondylodesis. For quality of life adjustment, the SF-36 health survey was applied. Pain and disability were measured using the Oswestry low-back pain disability questionnaire and visual analogue scales (VAS). Twelve patients were assigned to undergo anteroposterior spondylodesis and ten patients anterior spondylodesis. Postoperative improvement of spinal function, general health, well being, back pain, and mobility could be observed in both groups of patients. Better results of patients treated with anterior spondylodesis compared with anteroposterior spondylodesis were seen. No statistical difference was found between the two groups at any time. The less invasive nature of anterior spondylodesis could be responsible for that result.Anterior spondylodesis should used if possible and deemed adequate because it causes less discomfort.

Virulence genes and intimin types of Shiga-toxin-producing Escherichia coli isolated from cattle and beef products in Argentina

A total of 153 Shiga-toxin-producing Escherichia coli (STEC) isolates from feces of cattle and beef products (hamburgers and ground beef) in Argentina were characterized in this study. PCR showed that 22 (14%) isolates carried stx1 genes, 113 (74%) possessed stx2 genes and 18 (12%) both stx1 and stx2. Intimin (eae), enterohemolysin (ehxA), and STEC autoagglutinating adhesin (saa) virulence genes were detected in 36 (24%), 70 (46%) and in 34 (22%) of the isolates, respectively. None of 34 saa-positive isolates carried the gene eae, and 31 were ehxA-positive. Fourteen (7 of serotype O26:H11 and 4 of serotype O5:H-) isolates had intimin b1, 16 isolates possessed intimin g1 (11 of serotype O145:H- and 5 of serotype O157:H7), 5 isolates had intimin type e1 (4 of serotypes O103:H- and O103:H2), and one isolate O111:H- showed intimin type q/g2. Although the 153 STEC isolates belonged to 63 different seropathotypes, only 12 accounted for 58% of isolates. Seropathotype ONT:H- stx2 (18 isolates) was the most common, followed by O171:H2 stx2 (12 isolates), etc. The majority (84%) of STEC isolates belonged to serotypes previously found in human STEC and 56% to serotypes associated with STEC isolated from patients with hemolytic uremic syndrome (HUS). Thus, this study confirms that cattle are a major reservoir of STEC pathogenic for humans. To our knowledge, this is the first study that described the presence of saa gene in STEC of serotypes O20:H19, O39:H49, O74:H28, O79:H19, O116:H21, O120:H19, O141:H7, O141:H8, O174:H21, and ONT:H21. The serotypes O120:H19 and O185:H7 were not previously reported in bovine STEC.

Inducible nonviral gene expression in the treatment of osteochondral defects

OBJECTIVE

The repair of osteochondral defects with chondrocytes genetically modified to express desired growth factors promises great potential in orthopaedic therapy. Controlled expression of the transgenes is required in many instances. The objective of the present study was to demonstrate the inducibility of tetracycline-responsive transgene expression in osteochondral defects in the knee joint filled with genetically modified chondrocyte implants.

METHODS

An expression plasmid containing the lacZ gene under the control of the minimal CMV promoter fused to the Tet-responsible element (TRE) as well as the reverse transactivator (rtTA2s-M2) was constructed and used to transfect isolated articular chondrocytes from New Zealand white rabbits. rtTA2s-M2 binds to the TRE in the presence of tetracycline and leads to the transcription of the transgene. Different concentrations of DNA and various DNA:lipid ratios were tested to determine best transfection conditions. Transfection efficiency and inducibility were analysed by histochemical analysis and flow-cytometry. To evaluate the system in vivo, collagen-sponges were seeded with transfected autologous chondrocytes and implanted in osteochondral defects in the knees of NZW-rabbits. Gene expression was induced by doxycycline and 3 weeks later, LacZ-expression in isolated knee joints was evaluated in histological sections by X-gal staining.

RESULTS

In vitro 13.5% (+/-1.32) of induced primary chondrocytes were LacZ-positive, while non-induced controls showed a background-staining in 0.6% (+/-0.2). In vivo, upon doxycycline treatment, induction of lacZ-gene-expression could be demonstrated in chondrocytes in 3-week-old, well-integrated implants.

CONCLUSION

For the first time, tetracycline-inducible gene expression is demonstrated to work in the treatment of osteochondral defects. This demonstrates the feasibility for a gene therapy-assisted approach using controlled expression of therapeutic growth factors from transplanted genetically modified chondrocytes.

Two new cytoforms of the Simulium damnosum complex (Diptera: Simuliidae) from Malawi and Tanzania and potential onchocerciasis vectors

During a distribution survey of Simulium damnosum s.l. around the Tukuyu onchocerciasis focus at the northern tip of Lake Malawi/Nyasa (Tanzania), we discovered two new cytoforms of the S. damnosum complex in onchocerciasis-free areas. The Nyika form is related to Simulium thyolense, a vector of onchocerciasis, and can be identified by the new inversion 3L-L on the long arm of chromosome 3. It was found breeding in five rivers in northern Malawi and neighbouring Tanzania and is assumed to be zoophilic. The Njombe form represents a member of the Sanje group of the complex and is characterized by the new diagnostic inversion 2L-35 on chromosome 2. So far, it is only known from around Njombe town in southern Tanzania, where it breeds at remarkably high altitudes. Anthropophily for the Njombe form is well known. The medical importance and systematic position of the new forms within the S. damnosum complex are discussed.

Erste Ergebnisse ventraler versus dorsaler Instrumentation nach Ausräumung und intervertebraler Fusion bei Spondylodiszitis

AIM

The present study on spondylodiscitis patients was carried out to compare prospectively and randomized the results of clinical and radiological outcomes of anterior versus posterior instrumentation after debridement and grafting. We aimed to make a recommendation concerning the optimum treatment of spondylodiscitis.

METHOD

A total of 22 patients with spondylodiscitis were enrolled in the randomized trial to undergo an operation with anterior or posterior instrumentation after debridement and fusion with autologous bone transplant. 12 patients (group 1) were assigned to posterior Universal Spine System stabilization. 10 patients (group 2) were treated with anterior VentroFix instrumentation. In a prospective clinical investigation we have examined both operative therapies with regard to clinical and radiological outcome. The follow-up was one year.

RESULTS

In patients with ventral Spondylodesis (group 2), prior recreation of patients was achieved in clinical examination and blood tests. Radiological results are even equivalent in both groups. Therefore we recommend ventral instrumentation as the superior surgical procedure. But the individual local situation has to enable ventral stabilization.

CONCLUSION

We found advantages with anterior instrumentation in comparison to posterior stabilization in patients with spondylodiscitis. Advantages of ventral stabilization cause early mobilization postoperatively without any increase in complication rates. Except for operation time and intraoperative blood loss, no statistical difference were was seen. Important is the individual indication for each method depending on anatomical and clinical signs. Ventral instrumentation should be restricted to cases with sufficient bone stock.

Influence of antibiotic prophylaxis on perioperative risk in traumatology with the new concept of clinic modelling randomized trials in animals

Background

Surgical outcome depends not only on different therapies, but also on different additionally applied measures like prophylaxis (antibiotics, heparin, etc.) and their complex interaction. The aim of this study was to establish a new concept of clinic modelling randomized trials (CMRTs) in rats (haemorrhagic shock model) to investigate the harmful or beneficial effects of antibiotic prophylaxis in trauma patients (evidence-based medicine). Elements of the clinical scenario and methodology of randomized trials were modelled as accurately as possible in this CMRT.

Methods

Conditions of the rat model (CMRT) were adapted to the methodology of clinical trials and the clinical scenario with respect to sample size calculation, blinding and randomized allocation in a two-block design (n = 20 animals per group), anaesthesia with fentanyl–droperidol, standardized operation (soft tissue damage, tibia fracture and nailing), antibiotic prophylaxis 1 h before operation (intravenous cefuroxime 20 mg kg−1 versus placebo (sodium chloride)), volume substitution (Ringer) and postoperative analgesia. The clinical situation of healthy (American Society of Anesthesiologists (ASA) grade I and II) and severely injured (ASA III and IV) patients was simulated in the CMRT by sham operation and preoperative blood-letting, respectively, to initiate a relevant shock (1·5 h of mean arterial pressure 50 mmHg, blood pressure measured in the femoral artery). The shock period was followed by resuscitation (volume loading) with Ringer solution 40 ml kg−1. The endpoint was the 21-day mortality rate. Fracture healing was documented by radiography.

Results

The animal model was established successfully. The required blood-letting for relevant shock was 20 ml kg−1. The mortality rate in animals without blood-letting simulating healthy patients (ASA I and II) was zero in the cefuroxime and in placebo groups (n = 20 per group). In the experiment with preoperative blood-letting (ASA III and IV, n = 20 per group) a clear but not significant trend in the mortality rate for the cefuroxime group (20 per cent) versus placebo (40 per cent) could be observed (1 d.f., P > 0·05, χ2 test). Disturbances of fracture healing did not occur.

Conclusion

The clinical impact (evidence based) of antibiotic prophylaxis in traumatology was demonstrated in these experiments. The influence of other currently used antibiotics in trauma patients could be investigated in such animal models (CMRTs) instead of expensive and time-consuming clinical trials. The results of this study suggest the advantage of prophylaxis with cefuroxime in severely injured patients. Other antibiotics and the pathophysiological mechanisms will be investigated in further studies.

[Epulis in a newborn. histogenetic comparison with a granular cell tumor in adults]

The congenital granular cell tumor is a rare lesion of newborns located on the alveolar ridge with a marked predilection for female infants. Histologically these tumors are characterized by large eosinophilic granular cells, similar to granular cell tumors in adults which are often seen as Abrikossoff tumors. Immunohistochemical studies revealed the different histogenesis and evolution of both these tumor entities. We report on a female newborn infant with a congenital epulis of the left anterior maxillary alveolar ridge. This case demonstrates a rare congenital tumor of newborns and reveals the histogenetic differences to granular cell tumors in adults.

Magnetofection: enhancing and targeting gene delivery by magnetic force in vitro and in vivo

Low efficiencies of nonviral gene vectors, the receptor-dependent host tropism of adenoviral or low titers of retroviral vectors limit their utility in gene therapy. To overcome these deficiencies, we associated gene vectors with superparamagnetic nanoparticles and targeted gene delivery by application of a magnetic field. This potentiated the efficacy of any vector up to several hundred-fold, allowed reduction of the duration of gene delivery to minutes, extended the host tropism of adenoviral vectors to nonpermissive cells and compensated for low retroviral titer. More importantly, the high transduction efficiency observed in vitro was reproduced in vivo with magnetic field-guided local transfection in the gastrointestinal tract and in blood vessels. Magnetofection provides a novel tool for high throughput gene screening in vitro and can help to overcome fundamental limitations to gene therapy in vivo.

Two cases of autochthonous Plasmodium falciparum malaria in Germany with evidence for local transmission by indigenous Anopheles plumbeus

Autochthonous Plasmodium falciparum malaria (PFM) in Central Europe has been reported repeatedly, transmission of the parasite being attributed to blood transfusion or imported P. falciparum-infected vectors. We report two cases of PFM in German children without travel history to malaria-endemic areas. Both infections occurred during a stay in a hospital where a child from Angola with chronic P. falciparum infection was hospitalized at the time. Known routes of transmission, such as imported mosquitoes or blood transfusion, were very unlikely or could be excluded, whereas evidence was obtained for transmission by the indigenous mosquito species Anopheles plumbeus.

Synthesis of cyclo-1,3-dien-5-ynes

Cyclo-1,3-dien-5-ynes with ring sizes from 10 to 14 (6a-e) have been prepared for the first time by using a five-step synthesis starting from the alkynols 7a-e. The final ring-closure was achieved by McMurry coupling of the alpha,omega-dialdehydes 12a-e with the complex TiCl3(DME)1.5. Thermal isomerization of the cyclodienynes leads to the corresponding benzocycloalkenes, and it has been shown that the ring size has a considerable influence on the temperature necessary for thermocylization.

Procalcitonin following elective partial liver resection--origin from the liver?

BACKGROUND

The origin of the inflammatory peptide procalcitonin (PCT) is still unknown. In the present study PCT concentrations in arterial and hepatic-venous blood were examined in patients undergoing elective partial liver resection (LR) using a fiberoptic pulmonary arterial catheter placed in a liver vein to obtain further information on the origin of PCT.

METHODS

In 28 patients (21 male/7 female; average age of 58.8+/-8.8 years) undergoing LR, arterial and hepatic venous PCT concentrations were measured during 24 h perioperatively. The parallel blood withdrawals occurred immediately before the Pringle maneuver (Hx), 2 min, 1, 2, 6, 12, and 24 h after Hx. Over the whole period, the oxygen saturation in hepatic venous blood (ShvO2) was monitored. PCT concentrations were assayed by immunoluminometry.

RESULTS

We observed a significant increase in PCT concentration already 6 h after Hx compared to the values before Hx. Twenty-four hours after Hx we found the highest plasma concentrations. It was conspicuous that hepatic venous PCT concentrations were always higher than the arterial ones (significantly from the 6th hour after Hx). There was no correlation between the courses of ShvO2 and PCT rise. A significant correlation was verified between Hx duration and PCT concentration measured 24 h after Hx both in the hepatic venous and arterial blood.

CONCLUSIONS

The results of our investigation can be interpreted as evidence that liver (or the hepatosplanchnicus?) is a source of PCT. The mechanism of PCT induction cannot be clarified by our study: whether the induction of PCT was caused by an endotoxin translocation during the impeded splanchnic outflow or by the direct surgery-induced lesion (hypoxia) of the liver remains unclear. However, the latter appears more probable because of the observed correlation between Hx duration and PCT concentration rise.