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Biomedical subjects

I Paul

Publications and source records attributed to I Paul.

At least 19 recordsLinked to original sources

Quantum critical end point for the Kondo volume collapse model.

The Kondo volume collapse describes valence transitions in f-electron metals and is characterized by a line of first order transitions in the pressure-temperature phase plane terminated at critical end points. We analyze the quantum critical end point, when the lower end point is tuned to T=0, and determine the specific heat, thermal expansion, and compressibility. We find that the inclusion of quantum critical fluctuations leads to a novel bifurcation of the first order phase line. Finally, we show that critical strain fluctuations can cause both, superconductivity and non-Fermi liquid behavior near the critical point.

Journal Article↗

Pre-operative plasma erythropoietin concentration and survival following surgery for non-small cell lung cancer.

BACKGROUND: Suppression of the effect of the hormone erythropoietin (EPO) on the bone marrow, and an inadequate EPO response to anaemia have been shown to be factors in the genesis of cancer related anaemia. Low haemoglobin (Hb) concentration pre-operatively has been shown to have prognostic significance in patients with surgically resected NSCLC. This study investigates the relationship between pre-operative EPO and survival in patients having surgery for NSCLC. METHODS: Pre-operative plasma EPO concentration and haemoglobin concentration were analysed in patients undergoing surgery for NSCLC between April 1998 and January 1999. Full follow-up was available for all patients. RESULTS: Forty two patients were included. Median EPO concentration was 9.4 mIU/ml, range (3.7-56.4) with 17 patients (40.4%) having values above the normal range. Median haemoglobin concentration was 13.3g/dl (range 8.5-16.8) with 15 patients (26%) anaemic pre-operatively. Pathological staging revealed 17 (40.4%) patients with stage I, 6 (14.3%) with stage II, 19 (45.3%) with stage III disease. Ten patients had irresectable disease. There was a significant difference in median EPO but not haemoglobin concentration, between the different pathological stages. Survival was significantly lower in patients with pre-operative EPO >10.5 mIU. CONCLUSIONS: Raised pre-operative EPO is associated with reduced survival in patients having surgery for NSCLC. Its measurement should be considered in the pre-operative assessment of patients undergoing surgery for NSCLC. Further research is required to further investigate the biological relationship between EPO and NSCLC.

Adult↗

Case-control study for risk factors for Q fever in southwest England and Northern Ireland.

Q fever (Coxiella burnetti) is thought to account for 1% (700 cases) of community acquired pneumonia in the United Kingdom each year, and can result in serious complications such as endocarditis. Although outbreaks have frequently been reported worldwide, the causes are often not clearly identified and there have been few studies of risk factors in sporadic cases. We conducted a matched case-control study. Cases of acute Q fever in people aged over 15 years in southwest England and Northern Ireland were identified from January 2002 to December 2004. Controls were matched for age, sex and the general practice at which they were registered. Questionnaires asking about contact with animals, and leisure and work activities, were posted to cases and controls. Questionnaires were completed by 39/50 (78%) of the cases and 90/180 (50%) of the controls. In the single variable analysis, occupational exposure to animals or animal products was the only risk factor associated with cases at the 5% level (P=0.05, odds ratio (OR) 3.4). Long term illness appeared to be significantly protective (P=0.03, OR 0.3). In multivariable analysis the strength of association between occupational exposure and illness remained high (OR 3.6, 95% confidence interval (CI) 0.9 to 14.8) and smoking emerged as a possible risk factor. This is the first case-control study to identify occupational exposure to animals or animal products as the most likely route of infection in sporadic cases as opposed to outbreaks.

Adult↗

Quantum correction to conductivity close to a ferromagnetic quantum critical point in two dimensions.

We study the temperature dependence of the conductivity due to quantum interference processes for a two-dimensional disordered itinerant electron system close to a ferromagnetic quantum critical point. Near the quantum critical point, the crossover between diffusive and ballistic regimes of quantum interference effects occurs at a temperature T*=1/taugamma(E(F)tau)2, where gamma is the parameter associated with the Landau damping of the spin fluctuations, tau is the impurity scattering time, and E(F) is the Fermi energy. For a generic choice of parameters, T* is smaller than the nominal crossover scale 1/tau. In the ballistic quantum critical regime, the conductivity behaves as T1/3.

Journal Article↗

Perforation of the lower thoracic oesophagus following crush injury to the chest and abdomen.

We report a case of perforation of the lower thoracic oesophagus following a crush injury to the chest and upper abdomen. A laparotomy was performed for abdominal injuries, and appropriately placed drains resulted in complete resolution of the oesophageal leak, 21 days following the injury. This case report demonstrates that a conservative approach to lower thoracic oesophageal perforations can be carried out successfully without the added morbidity of a thoracotomy, or risks of a direct repair.

Adult↗

Endoscopic transanal resection of rectal tumours using a urological resectoscope--still has a role in selected patients.

INTRODUCTION: Transanal resection of rectal villous adenomas or adenocarcinomas can be carried out using various modalities such as operative excision, fulguration, laser coagulation or cryotherapy. Transanal endoscopic microsurgery is currently not widely available. Transanal resection can provide effective palliation for locally advanced rectal tumours in patients unfit for abdomino-perineal excision of rectum. A urological resectoscope can be safely and repeatedly used to resect advanced primary or locally recurrent rectal tumours by colorectal surgeons with urological expertise. This study reports our experience of treating rectal lesions with endoscopic transanal resection (ETAR) using the urological resectoscope. METHODS: Patients were identified from one surgeons' prospectively collected operating data. Charts were retrieved and reviewed. RESULTS: Over a 13-year period a total of 43 ETAR procedures were carried out in 20 patients (11 males; mean age 74 years; range 54-92 years) using the urological resectoscope. Twelve (60%) patients had a single resection; 8 (40%) patients required more than one resection; the mean number of procedures per patient was 2.2 (range 1-8). The median interval between resections for recurrent disease (excluding planned repeat resections) was 340 days (range 168-2337 days). Histopathology revealed rectal adenoma (with varying degrees of dysplasia) in 11 (55%) patients and adenocarcinoma in 9 (45%). The majority (30; 70%) of resections were carried out in patients with benign disease, with 13 (30%) in patients with rectal adenocarcinoma. Mean operating time per resection was 25 min. Thirteen (30%) resections were carried out under spinal anaesthetic. There was no procedure related mortality. There were no cases of haemorrhage, rectal perforation, 'TUR syndrome' or pelvic sepsis. No patients with benign disease subsequently developed an invasive carcinoma. CONCLUSIONS: Accepting that this technique provides limited histopathological information regarding extent of resection and tumour clearance, our experience demonstrates that ETAR of rectal tumours using the urological resectoscope can provide a minimally invasive, effective and safe means of treating and palliating patients with benign and malignant rectal disease. There remains a place for this technique in selected patients.

Adenocarcinoma↗

The social and family dynamics behind the uptake of cataract surgery: findings from Kilimanjaro region, Tanzania.

AIMS: To describe and understand better the barriers that elderly cataract patients in Kilimanjaro region (Tanzania) experience at the family level in order to access surgery. METHODS: A phenomenological study carried out in the catchment area of a teaching hospital in Kilimanjaro Region. 60 semi-structured interviews were conducted with patients and ex-cataract patients. RESULTS: The perceived need for sight and for surgery appears partly socially constructed at the family level. It was found that women were less likely to express a need for sight for fear of being seen as a burden. Furthermore, young heads of family are more inclined to support old men than old women. The consensus is that asking children for help can be difficult. Going for cataract surgery must be seen as a social process where elderly patients might have to wait or negotiate support for weeks, months, or even years. CONCLUSIONS: Eye programmes must promote the benefits of cataract surgery to all family members, not just to the patient. A changing social climate, changing expectations of vision, and evolving cost sharing systems will have significant, sometimes contradictory, impacts on use of eye care services. Strategies for reaching those without access to financial resources need to be strengthened.

Aged↗

Can tonic accommodation predict surgical performance?

BACKGROUND: Pilots undergo many visual tests for both selection and assessment, and we know that there are many similarities between pilots and surgeons. Hence, it would not be unreasonable to bring similar visual tests into surgery. Tonic accommodation (TA) is a stable parameter that is adopted by the eye in the absence of any stimulation. Over recent years, surgery has undergone change from traditional open surgery to minimally invasive procedures, bringing many advantages. However, not every surgeon has the ability to perform under conditions where the operative field is represented on a flat monitor. METHOD: We determined the TA values in medical students and then correlated this with their performance on a virtual reality surgical simulator. RESULTS: We found that TA values predicted the number of errors made with the dominant hand, accounting for 27% of the variance. CONCLUSION: The data suggest that TA may play a role in the individual differences that are noted when surgeons perform laparoscopic surgery. Further studies are needed to evaluate the exact role of TA in surgical performance.

Accommodation, Ocular↗

Glycosylated molecular variants of C-reactive proteins from the major carp Catla catla in fresh and polluted aquatic environments.

Elevated level of pollutant specific glycosylated molecular variants of C-reactive protein have been purified to electrophoretic homogeneity from the sera of major carp, Catla catla confined in freshwater (CRP(N)) and water polluted with nonlethal doses of cadmium (CRP(Cd)), mercury (CRP(Hg)), phenol (CRP(Ph)) and hexachlorocyclohexane (CRP(Hex)). These CRPs differ amongst themselves in electrophoretic mobility, and in their carbohydrate content ranging from 20-50%. CRPs interact with pneumococcal C-polysaccharide (CPS) showing different binding constants. Both phosphorylcholine (PC) and calcium are indispensable for binding. Studies on amino acid compositions, electrophoretic analysis, isoelectric focusing, binding to PC & CPS and secondary structures of the purified CRPs indicate, that, they differ from each other. However, they share the common properties of a CRP, including pentraxin structure revealed by electron microscopy. Taken together, our results provide a new structural insight regarding the connection between the presence of unique molecular variants and probably the toxicity therein combated.

Amino Acids↗

[What is the role of aceclofenac in the therapeutic arsenal against chronic osteoarthritis pathologies?].

The aim of this article is to critically review the potential role of aceclofenac in the treatment of inflammatory pain and chronic osteoarticular disorder, based on its activity on the mediators of inflammation, its effect on cartilage remodeling and on the results of clinical studies comparing aceclofenac with other NSAIDs in these disorders. Aceclofenac has an outstanding anti-inflammatory profile, involving besides a classical inhibition of prostaglandins E2, a decrease in the expression of several cytokines including interleukin 1 and tumor necrosis factor alpha. It also inhibits activated oxygen species production and influences cells adhesion. Aceclofenac and its main metabolite, 4-hydroxyaceclofenac, has positive effects on cartilage anabolism combined with modulating effect of matrix catabolism. Clinically, aceclofenac has been consistently shown to have a similar efficacy than that of widely marketed NSAIDs and a tolerance profile at least as good, if not better than the profile observed for other NSAIDs in the treatment of osteoarthritis, rheumatoid arthritis and ankylosing spondylitis. As of today, no head to head comparison between aceclofenac and coxibs have been performed, nor for efficacy neither for tolerance. The specific profile of aceclofenac makes this NSAID an interesting candidate for long-term treatment of chronic rheumatic disorders as well as for treatment of acute inflammatory episodes.

Anti-Inflammatory Agents, Non-Steroidal↗

[Pilot study for the registration of acute myocardial infarction in the Liège area (Belgium)].

BACKGROUND: In 1998, a permanent registry of myocardial infarction was developed in the Liège area (Belgium) to provide updated, exhaustive and validated data on the morbidity and mortality from cardiovascular causes, to define the patients' profile, to identify myocardial infarction therapeutic strategies and to complete and make comparisons with data collected in other parts of the country through methodologically identical registers. METHODS: All acute coronary events lethal or non lethal among individuals from both genders aged from 25 to 69 years and living in the area were registered according to the methodology developed for the MONICA project (Multinational Monitoring of Trends and Determinants in Cardiovascular Diseases) of WHO. The three main selected data sources were: death certificates, general practitioners and cardiologists, hospitals. The events were categorised according to symptoms, cardiac enzymes, electrocardiogram, history of chronic ischaemic heart disease and necropsy findings. RESULTS: The coronary-event rates were 283/100,000 in men and 102/100,000 in women. The case fatality rate, 28 days after the onset of the symptoms, was 30.6% for men and 36.2% for women, and 77.5% of deaths occurred in the first 24 hours after the onset of the symptoms. CONCLUSION: The development of a myocardial infarction register at a regional level requires the involvement of all health professionals dealing with that pathology. Such register has valuable public health interests, providing exhaustive and validated data on the pathology and its evolution as well as useful information for improving therapeutic strategies and developing adapted preventive measures.

Adult↗

A case of a persistent left vena cava superior with atresia of the right atrial ostium of the coronary sinus.

A persistent left vena cava superior with an atretic ostium of the coronary sinus was found during the routine dissecting course in the embalmed cadaver of an 83-year-old woman who had died from cardiac infarction. The left vena cava superior was very narrow in diameter (4 mm), originated at the lateral part of the left vena brachiocephalica and ran down between the venae pulmonales sinistrae and the auricula sinistra. The vena cava opened into the sinus coronarius of the heart, which terminated as a blind sac due to an atretic ostium. The vena coronaria sinistra as well as the vena interventricularis posterior drained into the sinus coronarius. Congenital atresia of the coronary opening is a rare malformation and is usually associated with other anomalies. The congenital ostial atresia could be the cause of a persistent left vena cava superior, which then takes over the drainage of the cardiac veins.

Aged↗

Mapping the distribution of 3-hydroxylipins in the Mucorales using immunofluorescence microscopy.

The distribution of endogenous 3-hydroxylipins (3-OH oxylipins) in representatives of the Mucorales was mapped using immunofluorescence microscopy. Strains of each of the following genera were examined: Absidia, Actinomucor, Cunninghamella, Mortierella (subgenus Micromucor), Mortierella (subgenus Mortierella), Mucor and Rhizomucor. Immunofluorescence microscopy was carried out using an antibody that was raised against 3R-hydroxy-5Z,8Z, 11 Z, 14Z-eicosatetraenoic acid (3R-HETE), which cross-reacts with other 3-OH oxylipins. Subsequently, the occurrence and distribution of the antibody on the various reproductive stages of each fungus was noted. In Absidia, Actinomucor, Mortierella (subgenus Micromucor), Mucor and Rhizomucor, 3-OH oxylipins were found to be associated with the columellae and/or wall of the sporangium. In the representative of Cunninghamella, the 3-OH oxylipins were associated with the single-spored sporangiola. No 3-OH oxylipins were detected in the strains representing Mortierella (subgenus Mortierella).

Fatty Acids↗

Depressive vulnerability is not an independent risk factor for osteoporosis in postmenopausal women.

Major depression has been repeatedly but not consistently reported to be associated with low bone mineral density (BMD) and to an increased risk for fracture in women. We have investigated, in healthy postmenopausal women, whether depressive symptomatology, assessed by the General Health Questionnaire (GHQ), was associated to a significant decrease in BMD, hence supporting the hypothesis of an independent pathogenetic link between the two disorders. We investigated 121 postmenopausal women, aged 48-77 years, spontaneously attending a screening visit for osteoporosis in an outpatient facility. BMD of the spine and the non-dominant hip (total and neck areas) were measured by Dual Energy X-Ray absorptiometry. All subjects completed to the 'General Health Questionnaire' translated and validated in French. No significant correlations were observed between the GHQ score and BMD of the spine (P = 0.54), the total hip area (P = 0.65), or the femoral neck area (P = 0.65). No differences in terms of spinal or femoral BMD were observed between women with GHQ score < 5 or > or = 5. When comparing values of BMD between women within the upper and the lower quartiles for GHQ score, no difference was observed for spine (P = 0.69), total hip (P = 0.80), or femoral neck (P = 0.93). Similarly, GHQ scores were not significantly different when comparing women in the upper and lower quartiles of BMD distribution at the spine or the hip. In conclusion, notwithstanding the clinical pattern of postmenopausal osteoporosis can lead to depression and, on the other hand, hormonal and behavioral disturbances reported in depression might be enhancing factors for accelerated bone loss, our present results do not support the hypothesis that otherwise healthy postmenopausal women with increased depressive complaints are also more prone to exhibit osteoporotic fractures.

Aged↗

Increased serum mitogenic activity for arterial smooth muscle cells associated with relaxation and low educational level in human subjects with high but not low hostility traits: implications for atherogenesis.

Proliferation of arterial smooth muscle cells (aSMC) is a key component of atherogenesis. A sample of 225 volunteers, aged 21-65 years, was exposed to "frustration," "harassment," or "relaxation," after completing the 50-item Hostility subscale of the Minnesota Multiphasic Personality Inventory (MMPI). Whole blood was measured before and after exposure for platelet-derived growth factor (PDGF), and sera were evaluated for total and HDL cholesterol concentrations and PDGF-independent mitogenic activity (SMA). Blood pressure and pulse rate were also evaluated. Analyses of SMA (i.e., serum independent of PDGF) revealed an increase in mitogenic effect for cultured human aSMC when hostility was treated as a dichotomous modifier. Among high-hostility subjects, surprisingly, those in the relaxed group and those with a lower educational level were found to have a significant mitogen response; no significant effects were observed for the low-hostility groups. The data suggest that endogenous stresses may occur in high-hostility individuals when "relaxed," to influence proliferation of arterial smooth muscle cells, as a contribution to atherogenesis. In individuals with lower educational levels and higher hostility scores, lifestyle changes may play a role.

Adult↗

Ultrasound-assisted ankle arthrocentesis.

Difficulty is frequently encountered in performing ankle arthrocentesis. This report describes an ultrasound-assisted technique that can be readily learned by emergency physicians. It involves using the ultrasound beam to accurately locate the tibiotalar joint, thereby increasing the probability of obtaining joint fluid on aspiration.

Adult↗