Nutritional supplementation for diabetic foot ulcers: the first RCT

OBJECTIVE

To determine if oral nutritional supplementation improved wound healing in malnourished patients with diabetic foot ulcers when compared with a placebo.

METHOD

This prospective randomised controlled double-blind trial involved patients aged over 60 with diabetes mellitus and a Wagner grade I-II foot ulcer of over four weeks' duration. Patients received either 400 ml (400 kcal) oral nutritional supplementation (n = 26) or 400 ml placebo (n = 27) daily for six months. Patients were followed monthly for six months and after one and two years.

RESULTS

A third of the patients were classified as having protein-energy malnutrition at inclusion, with no difference between the two groups. Critical leg ischaemia was more common in the intervention group than in the placebo group (p = 0.008). Nine patients in the intervention group (35%) and four in the placebo group (15%) dropped out of the study (not significant). Of those who completed the study, the wound had healed at six months in eight out of 23 patients (41%) (placebo) and in seven out of 17 (35%) (intervention) (not significant). Twenty-four per cent of patients with protein-energy malnutrition at inclusion had healed at six months compared with 50% of those without it (not significant).

CONCLUSION

This is the first study to evaluate the possible benefits of nutritional supplementation on diabetic foot ulcers. A third of patients were malnourished. We encountered several methodological problems and were unable to demonstrate an improved wound healing rate in these patients.

Position-effect variegation and z1 mediated white repression in the In(1)wis system in Drosophila melanogaster

We have characterized a new X-chromosomal inversion in Drosophila melanogaster, extending from just distal of white to just proximal of the bb locus. The inversion places the w-isoxanthopterinless (wis) allele close to heterochromatin and under the influence of position-effect variegation (PEV). The wis gene activity is also regulated by chromosome pairing-dependent z1-mediated repression. By changing the environment, using specific second site modifiers, altering the amount of heterochromatin, and disturbing the chromosome pairing, we have been able to separately affect the two regulatory phenomena and analyse their respective impact on the wis regulation. We provide evidence that under normal conditions PEV and z1 mediated white repression are additive. However, at extreme levels of wis repression by PEV, changes in the z1-mediated interactions are not observable. This indicates that PEV is epistatic to z1-mediated regulation of wis. We also show that deficiencies in the short arm of Y act as suppressors of the z1-mediated white repression. This suppression does not influence PEV and is thus not due to the lower amount of heterochromatin. We propose that nonhomologous chromosome pairing between X and Y is important for the synapsis-dependent z1-mediated repression of white transcription activity in this system.

Staphylococcus aureus, but not Staphylococcus epidermidis, modulates the oxidative response and induces apoptosis in human neutrophils

S. epidermidis is the most common isolate in foreign body infections. The aim of this study was to understand why S. epidermidis causes silent biomaterial infections. In view of the divergent inflammatory responses S. epidermidis and S. aureus cause in patients, we analyzed how they differ when interacting with human neutrophils. Neutrophils interacting with S. epidermidis strains isolated either from granulation tissue covering infected hip prostheses or from normal skin flora were tested by measuring the oxidative response as chemiluminescence and apoptosis as annexin V binding. Different S. aureus strains were tested in parallel. All S. epidermidis tested were unable to modulate the oxidative reaction in response to formyl-methionyl-leucyl-phenylalanine (fMLP) and did not provoke, but rather inhibited, apoptosis. In contrast, some S. aureus strains enhanced the oxidative reaction, and this priming capacity was linked to p38-mitogen-activated-protein-kinase (p38-MAPK) activation and induction of apoptosis. Our results may explain why S. epidermidis is a weak inducer of inflammation compared to S. aureus, and therefore responsible for the indolent and chronic course of S. epidermidis biomaterial infections.

Trainee anaesthetists understand their work in different ways: implications for specialist education

BACKGROUND

Traditionally, programmes for specialist education in anaesthesia and intensive care have been based on lists of attributes such as skills and knowledge. However, modern research in the science of teaching has shown that competence development is linked to changes in the way professionals understand their work. The aim of this study was to define the different ways in which trainee anaesthetists understand their work.

METHODS

Nineteen Swedish trainee anaesthetists were interviewed. The interviews sought the answers to three open-ended questions. (i). When do you feel you have been successful in your work? (ii). What is difficult or what hinders you in your work? (iii). What is the core of your anaesthesia work? Transcripts of the interviews were analysed by a phenomenographic approach, a research method aiming to determine the various ways a group of people understand a phenomenon.

RESULTS

Six ways of understanding their work were defined: giving anaesthesia according to a standard plan; taking responsibility for the patient's vital functions; minimizing the patient's suffering and making them feel safe; giving service to specialist doctors to facilitate their care of patients; organizing and leading the operating theatre and team; and developing one's own competence, using the experience gained from every new patient for learning.

CONCLUSIONS

Trainee anaesthetists understand their work in different ways. The trainee's understanding affects both his/her way of performing work tasks and how he/she develops new competences. A major task for teachers of anaesthesia is to create learning situations whereby trainees can focus on new aspects of their professional work and thus develop new ways of understanding it.

Impact of chronic and acute high-fat feeding on acute experimental pancreatitis complicated by endotoxinaemia

BACKGROUND

Obesity is associated with increased severity in patients with acute pancreatitis (AP). The underlying mechanisms are unknown. Genetically obese rats exhibit decreased survival rate in experimental AP, but the clinical relevance of this model of obesity may be questioned. It is proposed that development of organ failure in AP occurs in two stages: initial priming of leucocytes followed by a second inflammatory attack. The aim was to evaluate the impact of diet-induced obesity on outcome in a 'two-hit' model of AP.

METHODS

Lipopolysaccharide (LPS) was injected i.p. 3 h after retrograde bile duct infusion of sodium taurocholate in rats. Three experiments were done: 1) an LPS dose-response experiment, 2) chronic high-fat feeding (HF) for 16 weeks, and 3) acute HF for 10 days. Control rats received normal chow. Obesity, morphology and survival rate were assessed.

RESULTS

LPS dose-dependently decreased survival rate and increased morphological severity. HF increased weight, intra-abdominal and liver fat. Only acute HF induced hyperlipidaemia. In AP, acute obese rats exhibited less pancreatic inflammation, but total histological severity between groups was not different. In the chronic experiment only obese animals succumbed before 24 h of pancreatitis, but 72-h survival rate was not statistically different in either high-fat experiment.

CONCLUSION

An addition of LPS to AP decreases survival rate and intensifies the peri-pancreatic processes. Despite significant obesity, neither hyperlipidaemia nor increased intra-abdominal or hepatic fat influenced local pancreatic injury or survival negatively. The amount of fat per se seems not to be responsible for the deleterious influence of obesity on acute pancreatitis.

Early community outreach intervention in children with acquired brain injury

Ten patients with acquired brain injury were recruited over an 18 month period in the south-western health care region of Sweden in order to evaluate the costs and effectiveness of a multidisciplinary community outreach intervention programme. An experienced multidisciplinary project team was involved and patients underwent detailed functional, cognitive and motor assessments following initial contact within two weeks of injury, within six weeks of injury and at a 12-month follow-up. An individualized counselling programme was also offered. Of an expected recruitment number of 50 patients (based on epidemiological and population based figures) 10 children were reached, evaluated and followed; eight patients with traumatic brain injury (five severe, two moderate and one mild), and two patients with non-traumatic brain injury (both severe). At follow-up there was a significant improvement in motor function. No significant changes were seen in other areas of functional assessment or on neuropsychological measures although there were mild improvements in communication and behaviour functions. The financial costs per patient in the programme were deemed relatively modest compared with cost estimates of shorter-term in-patient rehabilitation. Time intensive interventions included supporting caregivers and school staff and the direct and indirect patient interventions were shown to enhance support and promote active involvement of local services.

Professional artist, good Samaritan, servant and co-ordinator: four ways of understanding the anaesthetist's work

BACKGROUND

Evaluating clinical competence among anaesthetists has so far focused mostly on theoretical knowledge and practical skills. According to theory, however, the way anaesthetists understand their own work has also greatly influenced the development of professional competence. The aim of this study was to investigate how anaesthetists understand their work.

METHODS

Nineteen Swedish anaesthetists were interviewed. The interviews were open and sought answers to three questions 1) When do you feel you have been successful in your work?; 2) What is difficult or what hinders you in your work?; and 3) What is the core of your professional anaesthesia work? Phenomenographic analysis was performed.

RESULTS

Four ways of understanding the anesthesiologists' professional work were found: 1) Give anaesthesia and control the patient's vital functions; 2) Help the patient, alleviate his/her pain and anxiety; 3) Give service to the whole hospital to facilitate the work of other doctors and nurses, caring for severely ill patients; and 4) Organize and direct the operation ward to make the operations list run smoothly.

CONCLUSIONS

This study shows that anaesthetists understand their work in qualitatively different ways, which can be assumed to affect their work actions and also the way their competence develops. This has implications for the education of anaesthetists; it is important to find ways of making anaesthetists in training consciously aware of the different ways their work can be understood, as this will give them better prerequisites for future competence development.

Influence of factor V Leiden on the development of neovascularisation secondary to central retinal vein occlusion

AIMS

To investigate if the presence of factor V Leiden has an influence on the prognosis in central retinal vein occlusion (CRVO).

METHODS

166 patients with CRVO were studied retrospectively. They were tested for factor V Leiden using DNA analysis. The presence of the mutation was studied in correlation with the development of neovascular complications 1 year after the thrombotic event.

RESULTS

56 of 166 patients (34%) developed neovascular complications after 1 year. In the patients who had the studied mutation 11 of 20 (55%) had developed neovascular complications after 1 year, compared to 45 of 146 patients (31%) in the group without factor V Leiden (p=0.04).

CONCLUSION

The presence of factor V Leiden seems to enhance the risk of developing neovascular complications in CRVO.

Evaluation and optimization of two complementary cross-flow ultrafiltration systems toward isolation of coastal surface water colloids

While colloidal phases in natural waters are important to the speciation and bioavailability of trace metals and organic compounds, accurate isolation of these submicron entities from their lower molecular-weight counterparts has proved challenging. Here, both laboratory and field experiments have been conducted to constrain integrity aspects of two different cross-flow filtration (CFF) systems. We tested both a commonly applied 5000 cm2 CFF system (Pellicon2, Millipore; manufacturer-specified 1 and 3 kDa cutoff) and a less studied mini-CFF system with a 50 cm2 membrane area (Pellicon Lab Scale XL, Millipore; with 5, 10, 100, and 1000 kDa cutoff). A natural water matrix amended with a series of fluorescently tagged colloidal probes was employed to demonstrate that a cross-flow ratio (CFR; retentate-to-permeate flux) > 15 was required for both of these systems to obtain high recoveries of colloids. Contrary to previous calibrations of CFF, also at colloid concentrations characteristic of natural waters, the established retention profiles for the colloid probes on these systems, when operated under CFR > 15, affirmed the manufacturer-specified cutoff values (in parentheses): 2.4 kDa (1 kDa), 3.3 kDa (3 kDa), 6.1 kDa (5 kDa) and 8.7 kD (10 kDa). A concentration factor (cf) > 10 was found necessary for the reliable determination of the colloidal pool of several elements in the surface waters of the open Baltic Sea. Application of CFR > 15 and cf > 10 returned recoveries around 100% for the studied organic carbon, Ca, Mo, Fe, Cu, and Ni on both systems. Furthermore, the trend of colloid association for the transition elements in the offshore Baltic surface waters followed expectations from their Irving-Williams series of coordination chemistry.

Obstructive jaundice results in increased liver expression of uncoupling protein 2 and intact skeletal muscle glucose metabolism in the rat

BACKGROUND

A majority of patients with pancreatic cancer have obstructive jaundice and diabetes with skeletal muscle insulin resistance. Surgery for these patients is associated with significant morbidity. Uncoupling protein 2 (UCP2) has been proposed to regulate energy expenditure and promote liver vulnerability. The effects of obstructive jaundice on muscle glucose metabolism and expression of UCP2 in liver and muscle are unknown.

METHODS

Rats were operated with bile duct ligation (BDL). After 7 days, UCP2 mRNA levels were determined in liver and muscle. Simultaneously, insulin-stimulated glucose transport and glycogen synthesis in skeletal muscle were analyzed in vitro.

RESULTS

The jaundiced rats lost more weight than pair-fed controls. UCP2 mRNA levels were increased 5-fold in liver but not in muscle in jaundiced rats compared to pair-fed controls. The jaundiced rats were hypoglycemic and hypoinsulinemic but demonstrated intact or enhanced insulin action on skeletal muscle glucose transport and glycogen synthesis in vitro. Muscle glycogen content was increased in the jaundiced rats.

CONCLUSIONS

Experimental obstructive jaundice in the rat is associated with increased liver expression of UCP2, rapid weight loss, and intact insulin action on skeletal muscle glucose metabolism. Obstructive jaundice, by upregulated liver UCP2, may contribute to the cachexia and high surgical morbidity observed in these patients, but not to skeletal muscle insulin resistance in pancreatic cancer patients.

The BTB/POZ domain of the regulatory proteins Bric à brac 1 (BAB1) and Bric à brac 2 (BAB2) interacts with the novel Drosophila TAF(II) factor BIP2/dTAF(II)155

The BTB/POZ domain is an evolutionarily conserved protein-protein interaction domain present in the N-terminal region of numerous transcription factors involved in development, chromatin remodeling, and human cancers. This domain is involved in homomeric and heteromeric associations with other BTB/POZ domains. The Drosophila BTB/POZ proteins Bric à brac 1 (BAB1) and Bric à brac 2 (BAB2) are developmentally regulated transcription factors which are involved in pattern formation along the proximo-distal axis of the leg and antenna, in the morphogenesis of the adult ovaries, and in the control of sexually dimorphic characters. We have identified partners of the BAB1 protein by using the two-hybrid system. The characterization of one of these proteins, called BIP2 for BAB Interacting Protein 2, is presented. BIP2 is a novel Drosophila TATA-box Protein Associated Factor (TAF(II)), also named dTAF(II)155. We show that the BTB/POZ domains of BAB1 and BAB2 are sufficient to mediate a direct interaction with BIP2/dTAF(II)155. This provides a direct link between these BTB/POZ transcription factors and the basal transcriptional machinery. We discuss the implications of the interaction between a BTB/POZ domain and a TAF(II) for the molecular mechanisms of transcriptional control mediated by BTB/POZ transcription factors.

Su(z)12, a novelDrosophilaPolycomb group gene that is conserved in vertebrates and plants

In both Drosophila and vertebrates, spatially restricted expression of HOX genes is controlled by the Polycomb group (PcG) repressors. Here we characterize a novel Drosophila PcG gene, Suppressor of zeste 12 (Su(z)12). Su(z)12 mutants exhibit very strong homeotic transformations and Su(z)12 function is required throughout development to maintain the repressed state of HOX genes. Unlike most other PcG mutations, Su(z)12 mutations are strong suppressors of position-effect variegation (PEV), suggesting that Su(z)12 also functions in heterochromatin-mediated repression. Furthermore, Su(z)12 function is required for germ cell development. The Su(z)12 protein is highly conserved in vertebrates and is related to the Arabidopsis proteins EMF2, FIS2 and VRN2. Notably, EMF2 is a repressor of floral homeotic genes. These results suggest that at least some of the regulatory machinery that controls homeotic gene expression is conserved between animals and plants.

Photopic 30 Hz flicker ERG as a predictor for rubeosis in central retinal vein occlusion

AIMS

To investigate the predictive value of the cone b-wave implicit time in the photopic compared with the scotopic 30 Hz flicker ERG for rubeosis in central retinal vein occlusion.

METHODS

44 patients with a central retinal vein occlusion were examined with full field electroretinogram (ERG).

RESULTS

The average implicit time in the photopic 30 Hz flicker ERG in patients who developed rubeosis (n=15) was 38.3 ms. In the patients who did not develop rubeosis (n=29) it was 31.3. The difference is statistically significant (p=0.0000000004).

CONCLUSION

The photopic cone b-wave implicit time in the 30 Hz flicker ERG is a good predictor for rubeosis.

Combined Phaco-Emulsification Cataract Extraction and Pars plana Vitrectomy without Intra-Ocular Lens Implantation

PURPOSE

To report the indications, surgical technique and visual outcome of combined phaco-emulsification cataract surgery and three-port pars plana vitrectomy (CPPV) in patients unsuitable for primary intra-ocular lens (IOL) implantation.

METHOD

A 4-year review in a tertiary referral hospital.

RESULTS

Thirty patients (30 eyes) had CPPV without primary IOL insertion. The patients had a mean pre-operative logMAR acuity of 1.81 (SD 0.49) which improved to 1.50 (SD 0.72) postoperatively (p = 0.036).

CONCLUSION

CPPV with primary IOL insertion is now an established surgical technique. This series suggests that patients with contra-indications to primary IOL insertion may also benefit from CPPV.

Role of CD18-dependent neutrophil recruitment in skin and intestinal wound healing

CD11/CD18 is an important adhesion molecule mediating recruitment of leukocytes, which, in turn, may cause postoperative injury in the skin and gastrointestinal tract. The objective of the present study was to investigate the effects of inhibiting the function of CD18 on surgery-induced dermal and intestinal infiltration of neutrophils and on the healing of surgical skin flaps and colonic anastomosis. A flap in the dorsal skin or an end-to-end colonic anastomosis were created in Sprague-Dawley rats. Skin necrosis and anastomotic breaking strength were analyzed 6 and 3 days after surgery, respectively. Tissue myeloperoxidase (MPO) was used as a marker of neutrophil recruitment. Administration of a monoclonal antibody directed against rat CD18 (WT.3, 2 mg/kg) significantly decreased dermal and anastomotic MPO activity by more than 80%. Passive immunization against CD18 significantly improved flap survival, i.e. the survival was 80% in the anti-CD18 antibody group as compared to 38% in the control group. In contrast, this passive immunization against CD18 had no effect on the reconstitution of the integrity of the colonic anastomosis, i.e. the anastomotic breaking strength was 1.3 +/- 0.1 and 1.3 +/- 0.3 N in the control and anti-CD18 antibody group, respectively. These findings suggest that specific inhibition of CD18 function and reduced neutrophil recruitment may improve the survival of experimental skin flaps and, thus, may represent a potential target for therapeutic intervention. In contrast, we also found that blocking CD18-dependent neutrophil infiltration in the intestine had no effect on breaking strength of colonic anastomosis. Thus, neutrophils may influence the wound-healing process differently in specific organs and this needs to be considered when applying an anti-inflammatory treatment regime in order to improve tissue healing.

Obesity increases the severity of acute experimental pancreatitis in the rat

BACKGROUND

Studies in patients with acute pancreatitis have shown a correlation between obesity and serious complications or a fatal outcome. However, the mechanisms by which obesity aggravates acute pancreatitis are not known. In the present study we used the sodium taurocholate model of pancreatitis to examine the effect of obesity on severity and outcome in acute experimental pancreatitis (AEP).

METHODS

AEP was induced at two degrees of severity by retrograde infusion of sodium taurocholate (0.2 ml x 3% or 0.4 ml x 3.5%) into the pancreatic duct of rats with obesity induced by high-fat diet, genetically obese (GO) rats or lean control rats. Surviving animals were sacrificed 72 h after induction of pancreatitis.

RESULTS

In the low-dose experiment, there were no significant differences in pancreatic histology or survival rate between the groups. In the high-dose experiment, the GO rats had a significantly lower 72-h survival rate than the high-fat obese (HFO) or lean control (LC) groups (GO 25% versus HFO 73%, P < 0.05; GO 25% versus LC 100%, P < 0.001). Survival rates in the high-dose experiment correlated strongly with basal liver fat content (R2 = 0.86). Pancreatic histology showed significantly more fat necrosis and a higher total pathological mean score in the HFO rats than in the LC animals (both P < 0.05).

CONCLUSIONS

Obesity had a negative influence on the outcome of necrotizing pancreatitis that was related to the magnitude of the pancreatic insult. The sodium taurocholate model in obese rats would be useful for future mechanistic studies of the effect of obesity on pancreatitis.

A 4D approach to the analysis of functional brain images: application to FMRI data

This paper presents a new approach to functional magnetic resonance imaging (FMRI) data analysis. The main difference lies in the view of what comprises an observation. Here we treat the data from one scanning session (comprising t volumes, say) as one observation. This is contrary to the conventional way of looking at the data where each session is treated as t different observations. Thus instead of viewing the v voxels comprising the 3D volume of the brain as the variables, we suggest the usage of the vt hypervoxels comprising the 4D volume of the brain-over-session as the variables. A linear model is fitted to the 4D volumes originating from different sessions. Parameter estimation and hypothesis testing in this model can be performed with standard techniques. The hypothesis testing generates 4D statistical images (SIs) to which any relevant test statistic can be applied. In this paper we describe two test statistics, one voxel based and one cluster based, that can be used to test a range of hypotheses. There are several benefits in treating the data from each session as one observation, two of which are: (i) the temporal characteristics of the signal can be investigated without an explicit model for the blood oxygenation level dependent (BOLD) contrast response function, and (ii) the observations (sessions) can be assumed to be independent and hence inference on the 4D SI can be made by nonparametric or Monte Carlo methods. The suggested 4D approach is applied to FMRI data and is shown to accurately detect the expected signal.

Painting of fourth, a chromosome-specific protein in Drosophila

Chromosome-specific gene regulation is known thus far only as a mechanism to equalize the transcriptional activity of the single male X chromosome with that of the two female X chromosomes. In Drosophila melanogaster, a complex including the five Male-Specific Lethal (MSL) proteins, "paints" the male X chromosome, mediating its hypertranscription. Here, with the molecular cloning of Painting of fourth (Pof), we describe a previously uncharacterized gene encoding a chromosome-specific protein in Drosophila. Unlike the MSL proteins, POF paints an autosome, the fourth chromosome of Drosophila melanogaster. Chromosome translocation analysis shows that the binding depends on an initiation site in the proximal region of chromosome 4 and spreads in cis to involve the entire chromosome. The spreading depends on sequences or structures specific to chromosome 4 and cannot extend to parts of other chromosomes translocated to the fourth. Spreading can also occur in trans to a paired homologue that lacks the initiation region. In the related species Drosophila busckii, POF paints the entire X chromosome exclusively in males, suggesting relationships between the fourth chromosome and the X and between POF complexes and dosage-compensation complexes.

Probing impulsive strain propagation with X-ray pulses

Pump-probe time-resolved x-ray diffraction of allowed and nearly forbidden reflections in InSb is used to follow the propagation of a coherent acoustic pulse generated by ultrafast laser excitation. The surface and bulk components of the strain could be simultaneously measured due to the large x-ray penetration depth. Comparison of the experimental data with dynamical diffraction simulations suggests that the conventional model for impulsively generated strain underestimates the partitioning of energy into coherent modes.

Pancreatic cancer cells require an EGF receptor-mediated autocrine pathway for proliferation in serum-free conditions

In-vitro and in-vivo studies have shown that autocrine growth factors and receptors are frequently expressed in human malignancies. Few of these studies, however, provide evidence that the identified autocrine pathway is functional. In this study, a functional autocrine growth pathway in pancreatic cancer has been identified using an in-vitro cell culture system. When pancreatic cancer cells were grown without change of medium, proliferation was greater than when either medium was replaced frequently (HPAF, CAPAN-2, PANC-1 or SW1990) or cells were grown in the presence of the EGF receptor tyrosine kinase inhibitor AG1478 or the MEK inhibitor PD098059 (HPAF or CAPAN-2). Activity of extracellular-regulated kinases (ERK) 1 and 2 and c- jun and c- fos mRNA levels were significantly elevated in CAPAN-2 cells cultured continuously in serum-free medium. Collectively, the observations indicate that the EGF receptor and the ERK MAP kinase pathway mediate autocrine signals. In contrast to previous reports, the GRP and IGF-I receptors were shown not to be required for autocrine effects on pancreatic cancer cell proliferation. Autocrine stimulation of the EGF receptor can contribute to sustained mitogenic activity and proliferation of pancreatic cancer cells.