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Biomedical subjects

A Paul

Publications and source records attributed to A Paul.

At least 55 records · Page 3Linked to original sources
PubMed2003

Obesity is a risk factor for recurrence after incisional hernia repair.

BACKGROUND: Any individualisation of incisional hernia repair requires a profound knowledge of risk factors for recurrence. METHODS: A series of 160 patients underwent incisional hernia repair and were prospectively followed up at 3, 6, 12, and 24 months after surgery. We analysed the importance of various variables to predict recurrence. RESULTS: An overall recurrence rate of 11% ( n=17) was observed. The risk for recurrence was not significantly affected by any of the clinical variables except for obesity ( P=0.03). Even when controlling for the influence of age, gender, hernia size, and surgical technique, obesity remained a significant predictor with a rate ratio of 1.10 per unit BMI (95%-CI: 1.02-1.18; P=0.01). CONCLUSION: This and other studies found hernia recurrence to be more likely in obese patients. Probably, such patients, therefore, should receive mesh rather than suture repair.

Adult↗
PubMed2003

Quasi-phase-matched generation of coherent extreme-ultraviolet light.

High-harmonic generation is a well-known method of producing coherent extreme-ultraviolet (EUV) light, with photon energies up to about 0.5 keV (refs 1, 2). This is achieved by focusing a femtosecond laser into a gas, and high harmonics of the fundamental laser frequency are radiated in the forward direction. However, although this process can generate high-energy photons, efficient high-harmonic generation has been demonstrated only for photon energies of the order 50-100 eV (ref. 5). Ionization of the gas prevents the laser and the EUV light from propagating at the same speed, which severely limits the conversion efficiency. Here we report a technique to overcome this problem, and demonstrate quasi-phase-matched frequency conversion of laser light into EUV. Using a modulated hollow-core waveguide to periodically vary the intensity of the laser light driving the conversion, we efficiently generate EUV light even in the presence of substantial ionization. The use of a modulated fibre shifts the energy spectrum of the high-harmonic light to significantly higher photon energies than would otherwise be possible. We expect that this technique could form the basis of coherent EUV sources for advanced lithography and high-resolution imaging applications. In future work, it might also be possible to generate isolated attosecond pulses.

Journal Article↗
PubMed2003

Soft tissue infections of the extremities in an orthopaedic centre in the UK.

OBJECTIVES: To determine the spectrum, and clinical impact of acute extremity soft tissue infections, encountered in the Orthopaedic service of an inner city hospital in UK. METHODS: Patients requiring admission for an acute limb soft tissue infection to the Orthopaedic unit of the Manchester Royal Infirmary, UK, between July 1996 and 2001 were identified from our database. Infections involving the groin and axilla, those developing within 30 days of a surgical procedure, and patients with chronic soft tissue ulcers or infections were not considered. RESULTS: Of 142 infections the majority were cellulitis (50%) and superficial abscesses (34.5%). Most were secondary to trauma (31.6%), human or animal bites (20%) and intravenous drug abuse (17.6%). Although most patients were young and otherwise healthy, ten developed significant complications: myonecrosis requiring below knee amputation (1), acute carpal tunnel syndrome (1), osteomyelitis (6), extensive skin loss requiring reconstruction (1), deep vein thrombosis (1). Seven hundred and eighty four hospital inpatient days and 143 operative interventions were devoted to these patients. The estimated cost for each episode of soft tissue infection was pound 1011. In 25% of cases earlier referral to a surgical service would have been more appropriate. CONCLUSIONS: Soft tissue infections of the extremities confer significant morbidity and impose an important burden on medical resources.

Adolescent↗
PubMed2003

Factors delaying surgical treatment of hip fractures in elderly patients.

BACKGROUND: Published guidelines recommend early surgical treatment of hip fractures in elderly patients. Understanding the factors that delay surgical intervention is essential in order to introduce changes that will facilitate early treatment. AIM: To determine the factors delaying surgical treatment of hip fractures in elderly patients for more than 24 h. PATIENTS AND METHODS: Assessment of 163 consecutive patients undergoing surgery for hip fractures at the trauma unit of Manchester Royal Infirmary. RESULTS: Only 72/163 (44.2%) patients had their operation within 24 h of presenting to hospital. The remaining 91 patients had a total of 239 days delay (in excess of the initial 24 h) for surgical treatment. Active medical problems (56.5%) and a wait for medical investigations (19.7%) caused most delays. Lack of operating theatre time and Sunday trauma lists caused 23.8% of delays. CONCLUSIONS: Medical problems account for most delays of surgical treatment of hip fractures. A multidisciplinary approach, with early input by medical and anaesthetic teams, is essential in managing such patients. Established protocols may reduce waiting times for essential investigations.

Aged↗
PubMed2003

Reduced delays in A&E for elderly patients with hip fractures.

Published guidelines recommend early transfer of patients with hip fractures to hospital wards and avoidance of unnecessary delays in A&E. We describe a protocol whereby the liaison of an orthopaedic trauma co-ordinator with A&E reduced A&E-to-ward transfer times by 43%. Following introduction of the new protocol, 39% of hip fracture patients were in a ward bed within 3 h of admission to A&E compared to 4% previously. The new protocol also reduces administrative workload for the on-call orthopaedic SHOs.

Aged↗
PubMed2002

Rheumatoid arthritis presenting as an invasive soft-tissue tumour.

BACKGROUND: We present two patients with advanced rheumatoid arthritis (RA) who were diagnosed as having malignant soft-tissue tumours on magnetic resonance scanning. They were tertiary referrals to a unit specialising in the management of soft-tissue sarcoma. CONCLUSIONS: Both of these tumours subsequently turned out to be benign complications of RA. In both of these cases, no mention was made on the initial radiological request form of the presence of RA. It is essential to give an adequate past medical history when requesting any radiological investigation.

Arthritis, Rheumatoid↗
PubMed2002

Laparoscopic resection of perforated Meckel's diverticulum in a patient with clinical symptoms of acute appendicitis.

We report the laparoscopic resection of a perforated Meckel's diverticulum (MD) found in a 14-year-old boy who presented with abdominal pain and nausea. There was rebound tenderness in the right lower quadrant of the abdomen, which appeared suspicious for acute appendicitis. The patient was referred to the operating room, and laparoscopic appendectomy was performed. With the appendix showing no macroscopic signs of inflammation, laparoscopy was continued and a perforated MD was identified 50 cm proximal to the ileocecal valve. The findings included pus and localized peritonitis between the ileal loops adjacent to the perforation site. The diverticulum was longitudinally resected with an Endo-Gia stapler. The histopathologic workup confirmed the diagnosis of a perforated MD. The patient completely recovered and was discharged 8 days after the procedures. At this writing, he is completely asymptomatic 6 months later. We conclude from our observation that laparoscopic resection of a perforated MD can be performed safely even when localized peritonitis is present. Inspection of the small intestine should be performed to exclude a symptomatic or perforated MD when the appendix does not show any signs of acute appendicitis.

Acute Disease↗
PubMed2002

[Incisional hernia repair in Germany at the crossroads: a comparison of two hospital surveys in 1995 and 2001].

INTRODUCTION: Incisional hernia repair has become a controversial issue in surgery. METHODS: To survey the current practice patterns of incisional hernia repair, a questionnaire was mailed to 2 380 surgical departments in Germany. Responses were received from 732 hospitals. The results of the current survey were compared with that of a similar survey performed in 1995. RESULTS: Overall, the incidence of incisional hernia surgery seems to have markedly increased. An increasing number of operations is performed in specialized large centres. Depending on hernia type (primary hernia < 5 cm, primary hernia > 5 cm, recurrent hernia) mesh materials have gained popularity (15 %, 67 %, and 79 %, respectively) as compared to 1995. Prolene(R) (34 %) and Vypro(R) (25 %) are the currently preferred meshes. The number of hospitals that use non-resorbable suturing material has doubled between 1995 (22 %) and 2001 (45 %). Interrupted suture are no longer the standard technique for fascia closure (80 % in 1995, 50 % in 2001). Autodermal skin graft and laparoscopic hernia repair are of little importance. Although literature data suggest high recurrence rates, most surgeons still expect that only 5-10 % of their primary or recurrent hernia repairs will fail. CONCLUSIONS: Incisional hernia repair is undergoing radical changes. However, it is unclear whether these changes in surgical techniques and materials were caused by the individual surgeon's clinical expertise, the recent publication of important trials, or the financial circumstances.

Cicatrix↗
PubMed2002

Intercomparison exercise of the PTB, BfS, MPA and PSI calibration facilities for radon gas concentration.

The traceability chain of one national reference laboratory (PTB) and three accredited radon calibration laboratories (BfS MPA and PSI) to internationally acknowledged radon gas standards is specified. As an additional tool for quality assurance, interchange of an electronic radon measuring instrument was used as a means for a relative comparison of the radon gas reference atmospheres. The instrument was exposed to radon gas activity concentrations between 500 Bq.m(-3) and 15 kBq.m(-3). Measured sensitivities of the participants agree well inside the range of specified calibration uncertainties.

Calibration↗
PubMed2001

Tyrosine residues in phospholipase Cgamma 2 essential for the enzyme function in B-cell signaling.

Phospholipase Cgamma (PLCgamma) isoforms are regulated through activation of tyrosine kinase-linked receptors. The importance of growth factor-stimulated phosphorylation of specific tyrosine residues has been documented for PLCgamma1; however, despite the critical importance of PLCgamma2 in B-cell signal transduction, neither the tyrosine kinase(s) that directly phosphorylate PLCgamma2 nor the sites in PLCgamma2 that become phosphorylated after stimulation are known. By measuring the ability of human PLCgamma2 to restore calcium responses to the B-cell receptor stimulation or oxidative stress in a B-cell line (DT40) deficient in PLCgamma2, we have demonstrated that two tyrosine residues, Tyr(753) and Tyr(759), were important for the PLCgamma2 signaling function. Furthermore, the double mutation Y753F/Y759F in PLCgamma2 resulted in a loss of tyrosine phosphorylation in stimulated DT40 cells. Of the two kinases that previously have been proposed to phosphorylate PLCgamma2, Btk, and Syk, purified Btk had much greater ability to phosphorylate recombinant PLCgamma2 in vitro, whereas Syk efficiently phosphorylated adapter protein BLNK. Using purified proteins to analyze the formation of complexes, we suggest that function of Syk is to phosphorylate BLNK, providing binding sites for PLCgamma2. Further analysis of PLCgamma2 tyrosine residues phosphorylated by Btk and several kinases from the Src family has suggested multiple sites of phosphorylation and, in the context of a peptide incorporating residues Tyr(753) and Tyr(759), shown preferential phosphorylation of Tyr(753).

Agammaglobulinaemia Tyrosine Kinase↗
PubMed2001

Proteinase-activated receptor-2-mediated activation of stress-activated protein kinases and inhibitory kappa B kinases in NCTC 2544 keratinocytes.

In this study we examined the regulation of the stress-activated protein (SAP) kinases and inhibitory kappa B kinases (IKKs) through stimulation of the novel G-protein-coupled receptor proteinase-activated receptor-2 in the human keratinocyte cell line NCTC2544. Trypsin and the peptide SLIGKV stimulated a time-dependent increase in both c-Jun N-terminal kinase and p38 mitogen-activated protein kinase activity. Trypsin also stimulated NF kappa B-DNA binding and the activation of the upstream kinases IKK alpha and -beta. Phorbol 12-myristate 13-acetate also strongly activated both SAP kinases and IKK isoforms, suggesting the potential for a protein kinase C-mediated regulatory mechanism underlying the effects of trypsin. Pre-incubation with selective protein kinase C (PKC) inhibitors GF109203X and Gö6983, or transfection of dominant negative (DN)-PKC alpha, abolished phorbol 12-myristate 13-acetate-mediated c-Jun N-terminal kinase activity, although it only partially inhibited the response to trypsin. In contrast, Gö6983 reduced trypsin-stimulated p38 mitogen-activated protein kinase activity to a greater extent than GF109203X, although DN-PKC alpha or PKC zeta had no substantial effect. Additionally, inhibitors of PKC partially reduced trypsin-stimulated IKK alpha activity but abolished that of IKK beta, whereas DN-PKC alpha but not DN-PKC zeta substantially reduced trypsin-stimulated Flag-IKK beta activity. This study shows for the first time proteinase-activated receptor-2-mediated stimulation of both SAP kinase and IKK signaling and differing roles for PKC isoforms in the regulation of each pathway.

Base Sequence↗
PubMed2001

Laparoscopic hernia repair in 2000. Update of the European Association for Endoscopic Surgery (EAES) Consensus Conference in Madrid, June 1994.

The 1994 meeting of the European Association for Endoscopic Surgery (E.A.E.S.) in Madrid highlighted a consensus-developing conference on the then new laparoscopic procedure for hernia repair. The conference was chaired by A. Paul from Cologne, Germany, and A. Fingerhut, from Poissy, France. The other members of the jury were B. Millat (France), L. Nyhus (USA), J. Himpens (Belgium), J.-L. Dulucq (France), V. Schumpelick (Germany), E. Laporte Rosello (Spain), C. Klaiber (Switzerland), J. Mouiel (France), P. Go (Netherlands), and J.-H. Alexandre (France). At that time, there were, in all, only three randomized trials available for analysis. Today, there are more than 60 trials and more than 12,500 patients have been entered into them. An update, presented this year in Vienna, is summarized herein.

Evidence-Based Medicine↗
PubMed2001

Extension of ischemic tolerance of porcine livers by cold preservation including postconditioning with gaseous oxygen.

BACKGROUND: Transplantation of organs from nonheartbeating donors was recommended to reduce organ shortage. In vitro experiments with rat livers have shown that the warm ischemic tolerance of the liver may be extended by persufflation with gaseous oxygen during cold storage. The qualification of this method for procurement of livers harvested after cardiac arrest was tested in an in vivo approach with pigs. METHODS: Livers from 15 donor pigs were explanted, heparinized, flushed with and stored in University of Wisconsin solution for 4 hr at 4 degrees C, and then implanted into 15 recipients. The organs were dissected immediately after cardiac arrest (group 1) or after 60 min of warm ischemia (groups 2 and 3). Group 2 livers received 75,000 IU of superoxide dismutase together with the flush solution and were persufflated with gaseous oxygen via the venous vascular system during cold storage. Main end point was survival after 5 days. Additionally, metabolic, functional and inflammatory criteria were measured in the blood. RESULTS: All animals of the groups 1 and 2 survived, all animals of group 3 died within 3 hr after reperfusion. In all groups the blood parameters reflected significant damage of the livers. However, the ischemic damage was comparable in the groups 1 and 2 whereas the livers of group 3 exhibited significantly higher levels of aspartate alanine aminotransferase and lactate dehydrogenase, and a significantly elongated partial thromboplastin time 1 hr after reperfusion (P=0.016). CONCLUSIONS: Venous systemic oxygen persufflation in combination with antioxidative medication is a promising new method of resuscitating ischemically altered livers from nonheartbeating donors for successful transplantation.

Animals↗