Increasing rates and clinical consequences of nalidixic acid-resistant isolates causing enteric fever in returned travellers: an 18-year experience

The purpose of this study was to examine the rate and clinical consequences of nalidixic acid-resistant (NAR) isolates in travellers with enteric fever presenting to a hospital in a developed country. We retrospectively examined microbiologically confirmed cases of enteric fever in adult returned travellers over an 18-year period presenting to two tertiary referral hospitals in Melbourne, Australia. There were 59 cases of Salmonella typhi infection, 43 cases of S. paratyphi A infection and two cases of S. paratyphi B infection. Most patients reported recent travel to India (36%) or Indonesia (29%). NAR isolates were commonly encountered (41% of all isolates), particularly from India (75%), Pakistan (80%) and Bangladesh (60%). The number of NAR isolates increased progressively after 2003. Patients with NAR isolates had prolonged mean fever clearance time (5.6 vs. 3.3 days, P = 0.03) and prolonged hospital stay (7.9 vs. 5.7 days, P = 0.02) compared to non-resistant isolates. This represents the largest report of NAR enteric fever in returned travellers. NAR isolates predominate in cases of enteric fever from South Asia and result in prolonged fever clearance time and hospital stay. Empiric therapy with alternative antibiotics such as ceftriaxone or azithromycin should be considered in patients with suspected enteric fever from this region.

ElePhant--an anatomical electronic phantom as simulation-system for otologic surgery

This paper describes the ElePhant (Electronic Phantom)-an anatomical correct simulation system based on 3D rapid prototyping models for the otologic intervention "Mastoidectomy". The anatomical structures of the head are created with plaster as base material using 3D-printing as rapid prototyping technology (RPT). Structures at risk, represented by electrically conductible material and fiber optics, are realized as an electric circuit and can be detected during the simulation of the surgical procedure. An accuracy study of 15 identical RPT-models compared to the 3D reconstructed CT-dataset of the patient showed that the mean accuracy is lower than the reconstructed CT layer thickness of 0.5 mm. An evaluation study of the ElePhant-system for "Mastoidectomy" was performed by 7 ENT-surgeons. The mean value of the study questionnaire (evaluation range from -2 (not at all) to +2 (very good)) was +1.2. The results showed that the ElePhant can simulate "Mastoidectomy" realistically. It is especially suitable for the simulation of the correct representation and position of the anatomical structures, realistic operation setting, and realistic milling properties of the bone structure. Furthermore it is applicable for training of surgeons.

[Nasal dermoid and sinus cysts in patients with cleft malformations]

BACKGROUND

Nasal dermoid sinus cysts are uncommon congenital lesions. They are usually isolated occurrences and are not associated with syndromes or additional malformations. The coincidence of both, cleft malformations and nasal dermoid sinus cysts, has seldom been reported.

CASE REPORTS

Within the last 2 years two patients with reconstructed cleft lip and palate and additional nasal dermoid sinus cysts underwent surgical removal. One patient with bilateral complete cleft lip exhibited a fistula from the medial third of the nasal dorsum up to the glabella. Another patient with unilateral cleft lip and Peters' plus syndrome had undergone removal of a nasal dermoid sinus cyst 12 years ago and was referred for management of recurrent disease.

DISCUSSION

Concerning the common cleft-dependent nose malformations with no midline nasal masses, there are reasons for the assumption that a coincidence of both anomalies might be accidental. Especially in Peters' plus syndrome no frequent occurrence of nasal dermoids has thus far been documented. However, the proximity and temporal closeness of an embryological pathway of the frontonasal region and lip development could also argue for a unique formation of both lesions. Complete surgical removal and plastic reconstruction simultaneously or in a second step are recommended.

Alteration of gene expression in rat colon mucosa after exercise

The development of colon cancer is highly influenced by lifestyle factors such as nutrition and physical inactivity. Detailed biological mechanisms are thus far unclear. The purpose of this study was to investigate the effects of regular treadmill exercise on gene expression in rat colon mucosa. For this purpose, 6-week-old male Wistar rats completed a stress-free voluntary treadmill exercise period of 12 weeks. Sedentary rats served as a control group. In the colon mucosa, steady-state mRNA expression levels of approximately 10,000 genes were compared between both groups by micro-array analysis (MWG rat 10K array). A total of 8846 mRNAs were detected above background level. Regular exercise led to a decreased expression of 47 genes at a threshold-factor of 2.0. Three genes were found to be up-regulated in the exercise group. The identified genes encode proteins involved in signal transduction (n=11), transport (n=8), immune system (n=7), cytoskeleton (n=6), protein targeting (n=6), metabolism (n=5), transcription (n=3) and vascularization (n=2). Among the genes regulated by regular exercise, the betaine-homocysteine methyltransferase 2 (BHMT2) seems to be of particular interest. Physical activity may protect against aberrant methylation by repressing the BHMT2 gene and thus contribute to a decreased risk of developing colon cancer. We have also identified vascular endothelial growth factor (VEGF), angiopoietin-2 (ANG-2) and calcium-independent phospholipase a2 (iPL-A2), all of them with markedly reduced transcript levels in the mucosa of active rats. In summary, our experiment presents the first gene expression pattern in rat colon mucosa following regular treadmill activity and represents an important step in understanding the molecular mechanisms responsible for the preventive effect of physical activity on the development of colon cancer.

Exercise Associated Genes in Rat Colon Mucosa: Upregulation of Ornithin Decarboxylase-1

Epidemiology has revealed that physical activity is an important lifestyle factor that reduces the risk of colon cancer. However, the underlying mechanisms of this protective effect have so far not been defined. The aim of this study was to identify molecular targets of physical activity in rat colon mucosa by employing our voluntary exercise model. Twenty male rats underwent a 12-week exercise program, with 9 additional rats serving as a control group. Running distances, body weights and heart weights as measures of physical adaptations were recorded, and changes in mRNA steady-state levels of marker genes involved in vascularization (VEGF, HIF-1 alpha, ODC-1), apoptosis (Bcl-2, PPAR gamma) and prostaglandin synthesis (COX-2) were determined by qRT-PCR. The four housekeeping genes GAPDH, beta-actin, 18S and ALDA served as reference genes. Recorded running distances showed great inter-individual differences resulting in three different groups of low (L-EX, < 2629 m/night; n=5), moderate (M-EX, 3003 - 7458 m/night; n=10) and high (H-EX, > 8314 m/night; n=5) physical activity. The M-EX and H-EX group revealed significant (p<0.05) adaptive changes with an increase in heart mass per kg body weight and a decrease in mean body weight. Amongst the marker genes studied by mRNA expression analysis only ODC-1 appears to be differentially expressed. Its 1.8-fold increased steady-state mRNA level in the H-EX group suggests that synthesis of polyamines may be increased by physical activity. This new finding could provide a link between extensive physical activity and its protective effects on colon cancer development.

Alterations of pancreatic beta-cell mass and islet number due to Ins2-controlled expression of Cre recombinase: RIP-Cre revisited; part 2

Tissue-specific disruption of genes by targeted expression of Cre recombinase in insulin-producing cells has been widely used to explore pathways involved in regulation of pancreatic beta-cell mass. One particular line of transgenic mice [B6.Cg-Tg(Ins2-cre)25Mgn/J], commonly called RIP-Cre, in which the expression of Cre recombinase is controlled by a short fragment of the rat insulin II gene promoter has been used on at least 20 genes in at least 27 studies. In the majority of these studies (15 out of 27) inactivation of the gene of interest was associated with alterations in islet architecture, islet mass, or pancreatic insulin content. We have tested the hypothesis that genomic integration or expression of Cre recombinase alone causes alterations of beta-cell mass by quantifying islet number and mass in RIP-Cre mice. We have observed a significant hypoplasia of beta-cells in young RIP-Cre mice, and a significant hyperplasia of islets in older RIP-Cre animals. These findings suggest that glucose intolerance and impaired insulin secretion previously described for younger RIP-Cre mice might be caused by transgene-associated islet hypoplasia, and that hyperplasia in older mice might reflect a compensatory response to transgene-related glucose intolerance.

Surgery on the lateral skull base with the navigated controlled drill employed for a mastoidectomy (pre clinical evaluation)

Patients who are treated with a mastoidectomy usually suffer from an inflammation of the petrosal bone. The intervention is a time consuming landmark based surgery and usually performed with a powered drill. Delicate risk structures must be respected. Navigated Control (NC) describes the control for a power driven instrument which is controlled by a surgeon and additionally controlled according to the position of the instrument relatively to a deliberated position known from a preoperatively segmented work space which excludes risk structures. The force of a drill can be regulated by the principle of NC. Following results were received: 1. Risk structure segmentation is feasible 2. The drill and a phantom can be registered. 3. With NC the resection is faster, more accurate and with no risk structures damage. 4. The phantom is suitable.