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Biomedical subjects

P Borg

Publications and source records attributed to P Borg.

13 recordsLinked to original sources
PubMed2006

Successful weight maintenance preserves lower levels of oxidized LDL achieved by weight reduction in obese men.

OBJECTIVE: We studied the association between weight maintenance, oxidized low-density lipoprotein (ox-LDL) and other lipoproteins in obese men. METHODS: A 2-month weight reduction phase (WRP) with a very-low-energy diet was followed by a 6-month weight maintenance period and an unsupervised 2-year follow-up. Ninety men entered and 68 (76%) completed the study. Subjects were analyzed as one group and after division into two subgroups: 20 most successful men in maintaining the lost weight (subgroup 1) and the remaining (n=48) men (subgroup 2). Ox-LDL was measured by quantifying the amount of conjugated dienes in LDL particles. RESULTS: The mean (+/-s.d.) weight reduction at the end of the WRP (n=68) was 14% (confidence interval (CI) 12.9-14.7%, 14.5+/-4.2 kg, P<0.001). Ox-LDL decreased by 22% (CI 16.9-28.1, 12.3+/-15.4 micromol/l, P<0.001). At the end of the 2-year follow-up, the regain in weight from the end of the WRP was 11% (CI 9.0-12.4, 9.6+/-6.2 kg, P<0.001). The regain in ox-LDL was 30% (CI 18.7-41.2, 8.2+/-15.4 micromol/l, P<0.001). In subgroup 1 vs 2, the respective regains were 3% (CI 0.9-4.2, 2.2+/-3.0 kg, P=0.006) vs 14% (CI 12.7-15.6, 12.9+/-4.0 kg, P<0.001) regarding weight and 9% (2.0+/-6.9 micromol/l, P=NS) vs 39% (CI 23.7-53.9, 11.2+/-17.2 micromol/l, P</=0.001) in ox-LDL. CONCLUSION: The favorable changes seen in ox-LDL particles and serum lipids during weight reduction could be maintained by keeping the weight reduced, which may indicate decreased risk of atherosclerosis. But weight regain causes a resurge of ox-LDL.

Adult↗
PubMed2004

Food selection and eating behaviour during weight maintenance intervention and 2-y follow-up in obese men.

OBJECTIVE: The aim was to assess long-term changes in food consumption and eating behaviour during and 2 y after dietary counselling in weight-reduced obese men. DESIGN: Observational study from a randomised controlled trial. SETTING: Outpatient clinic of a research institute. SUBJECTS: A total of 36 subjects with complete data on food intake during the study. Subjects were obese (mean body mass index (BMI) 32.8 kg/m2) men aged 35-50 y, recruited by media advertising. INTERVENTIONS: Dietary counselling was included in 2 months weight reduction with very-low-energy-diet and in 6 months weight maintenance programme, which also included physical activity counselling. This was followed by a 23 months unsupervised follow-up with yearly assessments. Food intake was assessed six times during the study by 4-day food records. Eating behaviour was assessed by Three-Factor Eating Questionnaire (TFEQ). RESULTS: Increased consumption of low-fat cheese, low-fat margarine, vegetables and high-fibre bread, and decreased consumption of sugar, sausage, high-fat cheese, high-fat margarine, fat products and sweets were observed during dietary counselling. Most of these changes returned later to prestudy consumption level. The relapse in dietary changes was partly associated with scoring low in restraint and high in disinhibition and hunger. CONCLUSION: In obese men, long-term maintenance of dietary changes was difficult. New ways to ease self-monitoring and increase self-efficacy might be necessary to improve maintenance of dietary changes.

Adult↗
PubMed2002

Effects of walking or resistance training on weight loss maintenance in obese, middle-aged men: a randomized trial.

OBJECTIVE: To investigate whether walking or resistance training improves weight maintenance after weight loss when added to dietary counselling. DESIGN: Two months' weight reduction with very-low-energy-diet (VLED) followed by randomization into three groups (control, walking, resistance training) for 6 months' weight maintenance (WM) program and 23 months' unsupervised follow-up. During VLED and WM all groups received similar dietary counselling. SUBJECTS: The main inclusion criteria were BMI >30 kg/m(2), waist>100 cm and physical inactivity (exercise < or = once a week). Ninety healthy, obese (mean BMI 32.9 kg/m(2) and waist 112.5 cm), 35-50 y-old men started the study and 68 were measured at the end of the study. MEASUREMENTS: Weight and body composition assessed by underwater weighing. Exercise diaries and dietary records to assess energy balance. RESULTS: During VLED the mean body weight decreased from 106.0 (s.d. 9.9) kg to 91.7 (9.4) kg. Weight was regained mostly during follow-up and in the end of the study the mean weight in groups was 99.9-102.0 kg. Exercise training did not improve short or long-term weight maintenance when compared to the control group. However, resistance training attenuated the regain of body fat mass during WM (P=0.0l), but not during follow-up. In the combined groups the estimated total energy expenditure (EE) of reported physical activity was associated with less weight regain during WM. EE of 10.1 MJ/week was associated with maintaining weight after weight loss. EE of physical activity tended to decrease after WM in exercise groups due to poor long-term adherence to prescribed exercise. Energy intake seemed to increase during follow-up. CONCLUSION: Exercise training of moderate dose did not seem to improve long-term weight maintenance because of poor adherence to prescribed exercise.

Adult↗
PubMed2001

The validity of predicted body fat percentage from body mass index and from impedance in samples of five European populations.

OBJECTIVES: To test and compare the validity of a body mass index (BMI)-based prediction equation and an impedance-based prediction equation for body fat percentage among various European population groups. DESIGN: Cross-sectional observational study. SETTINGS: The study was performed in five different European centres: Maastricht and Wageningen (The Netherlands), Milan and Rome (Italy) and Tampere (Finland), where body composition studies are routinely performed. SUBJECTS: A total of 234 females and 182 males, aged 18-70 y, BMI 17.0-41.9 kg/m(2). METHODS: The reference method for body fat percentage (BF%(REF)) was either dual-energy X-ray absorptiometry (DXA) or densitometry (underwater weighing). Body fat percentage (BF%) was also predicted from BMI, age and sex (BF%(BMI)) or with a hand-held impedance analyser that uses in addition to arm impedance weight, height, age and sex as predictors (BF%(IMP)). RESULTS: The overall mean (+/-s.e.) bias (measured minus predicted) for BF%(BMI) was 0.2+/-0.3 (NS) and-0.7+/-0.3 (NS) in females and males, respectively. The bias of BF%(IMP) was 0.2+/-0.2 (NS) and 1.0+/-0.4 (P<0.01) for females and males, respectively. There were significant differences in biases among the centres. The biases were correlated with level of BF% and with age. After correction for differences in age and BF% between the centres the bias of BF%(BMI) was not significantly different from zero in each centre and was not different among the centres anymore. The bias of BF%(IMP) decreased after correction and was significant from zero and significant from the other centres only in males from Tampere. Generally, individual biases can be high, leading to a considerable misclassification of obesity. The individual misclassification was generally higher with the BMI-based prediction. CONCLUSIONS: The prediction formulas give generally good estimates of BF% on a group level in the five population samples, except for the males from Tampere. More comparative studies should be conducted to get better insight in the generalisation of prediction methods and formulas. Individual results and classifications have to be interpreted with caution.

Absorptiometry, Photon↗
PubMed2001

Stray radiofrequency current as a cause of urethral strictures after transurethral resection of the prostate.

PURPOSE: This study was designed to define the pattern and significance of stray currents induced by two electrosurgical generators (ESGs) in relation to urethral strictures forming after transurethral resection of the prostate (TURP). MATERIALS AND METHODS: A 24F resectoscope irrigated with glycine was activated at various power outputs in different modes, with intact loops and loops with faulty insulation, simulating TURP. The Valleylab and ERBE ESGs were compared for inducing capacitance. An ESG analyzer simulated tissue impedance and recorded the stray currents induced along the resectoscope sheath. A fresh pig liver was used for assessment of tissue damage caused by the currents. RESULTS: In the cutting mode, the ERBE ESG produced a mean stray current of 70 mA with an intact loop and 144 mA with a loop having faulty insulation. The Valleylab ESG produced 150 mA and 161 mA, respectively. In the coagulation mode, the ERBE ESG produced an average leakage current of 35 mA and, with a loop with faulty insulation, 40 mA. The Valleylab ESG produced 148 mA and 151 mA, respectively. CONCLUSIONS: Electrical injury may represent a significant cause of urethral stricture after transurethral electrosurgery. The critical power density of 7.5 W/cm2 (which is likely to cause a urethral burn) may be reached, especially with the use of loops with faulty insulation or nonconductive lubricating gel. The ERBE ESG produced significantly less capacitance, decreasing the risk of urethral electrical burn. Conductive gel prevents dangerous current concentration.

Electric Injuries↗
PubMed2000

Biosensor analysis of the interaction between immobilized human serum albumin and drug compounds for prediction of human serum albumin binding levels.

The interactions between a set of drugs, selected on the basis of reported human serum albumin (HSA) binding levels, and immobilized HSA were investigated using surface plasmon resonance technology. Major HSA binding sites were available after immobilization. The intensity of the signal obtained from the interaction of the drug with the HSA surface was correlated with the reported HSA binding level. Drugs were classified into groups corresponding to high, medium, or low HSA binding based on the injection of the drug at 80 microM concentration. A set of 10 drugs binding to alpha(1)-acid glycoprotein (AGP) was also investigated and correlated with reported AGP binding data. The throughput of the presented assay is 100 compounds/24 h, and the sample consumption is less than 100 microL (8 nmol).

Binding Sites↗
PubMed2000

Biosensor analysis of drug-target interactions: direct and competitive binding assays for investigation of interactions between thrombin and thrombin inhibitors.

The sensitivity of BIACORE technology is sufficient for detection and characterization of binding events involving low-molecular-weight compounds and their immobilized protein targets. The technology requires no labeling and provides information on the stability of the compound/target complex with a single injection of the compound. This is useful for qualifying hits obtained in a primary screen and in lead optimization. Although immobilized targets can be reused, the surface may slowly deteriorate, solvent effects can distort binding levels during injection of compounds, and some compounds may exhibit broad protein selectivity rather than target specificity. A reliable direct binding assay for compounds binding to immobilized thrombin using a combination of two reference surfaces, a dextran surface for subtraction and calibration of solvent effects and a protein surface for identification of compounds that tend to bind proteins, has been developed. Eleven compounds with known binding specificity to thrombin and 159 additional compounds were investigated. All compounds with known binding specificity were identified at 1 and 10 microM concentration. One additional compound was scored as positive. The direct binding assay compared favorably with two competitive assay formats, a surface competitive assay and a inhibitor in solution assay, that were examined in parallel.

Antithrombins↗
PubMed2000

[Use of methadone in the treatment of psychotic patients with heroin dependence].

Comorbidity of psychosis and substance abuse has gained increased attention for some time. However, pharmacological treatment for opioid dependence among psychotic patients is seldom described. We present the treatment of four opioid dependent psychotic patients with methadone and antipsychotic medication. Three of the four patients had initially a period of increased psychotic symptoms, but all four patients have shown marked improvement following the introduction of methadone. Compliance with treatment has increased, they have had enduring non-psychotic periods and a markedly reduced use of illegal substances. The results should obviously be interpreted with caution, given the small number of subjects. Further research is therefore important.

Adult↗
PubMed2000

Intended and stray radiofrequency electrical currents during resectoscopic surgery.

STUDY OBJECTIVE: To test the hypothesis that electrical burns of the genital tract and urethral strictures after hysteroscopic endometrial ablation and transurethral prostatectomy, respectively, are related to capacitive coupling and/or stray currents induced by intact and defective electrodes and/or resectoscopes. DESIGN: Basic in vitro measurements. SETTING: Laboratory. MATERIALS: Porcine muscle and liver, resectoscope, electrosurgical unit (ESU), and ESU analyzer. INTERVENTION: We measured electrical coagulation and cutting currents of rollerball and loop electrodes and the external sheath of the resectoscope from 80 to 200 W through a resistance load of 200 and 250 ohms, using intact electrodes and conditions simulating potential insulation defects along the shaft of the electrodes. MEASUREMENTS AND MAIN RESULTS: Approximately 20% to 25% of current was induced by capacitive coupling to the resectoscope sheath. Touching porcine muscle or liver with small areas of the sheath while the generator was activated resulted in superficial tissue burn. Surrounding large segments of the sheath with tissue did not result in visible burns, indicating that under normal conditions the sheath acts as a dispersive electrode. Defective insulation of distal segments of the electrodes resulted in 100% transfer of current to the sheath and caused extensive electrical burns of tissue in contact with the sheath. CONCLUSIONS: Capacitive coupled currents induced by intact resectoscopes and electrodes may cause thermal injury to surrounding tissue during prolonged resectoscopic surgery. Stray currents from defective insulation of the electrodes result in direct coupling of current to the telescope and sheath and cause extensive burns of surrounding tissues in contact with the sheath.

Animals↗
PubMed2000

Genital tract electrical burns during hysteroscopic endometrial ablation: report of 13 cases in the United States and Canada.

We investigated 13 alleged thermal injuries to the genital tract of women undergoing hysteroscopic endometrial ablation. Possible mechanisms proposed to explain these injuries are hot-weighted speculum, povidone-iodine scrub solution, inadequate rinsing of Cidex sterilizing solution, and electrical burns. The history, nature, and distribution, as well as experimental evidence strongly support the hypothesis that these injuries are electrical due to capacitive coupled currents induced onto the sheath of the resectoscope, and/or stray currents generated by arcing or direct coupling from defective electrode insulation to the telescope, electrifying the entire resectoscope.

Adult↗
PubMed2000

Electrical burn of urethra as cause of stricture after transurethral resection.

BACKGROUND AND PURPOSE: One of the most common complications of transurethral resection is urethral stricture. The exact etiology is still controversial. Postulated pathophysiology ranges from mechanical trauma to the urethra during the resection to inflammatory reaction secondary to local anesthesia. We propose electrical burn to the urethra as a contributory factor in some cases. MATERIALS AND METHODS: Electrical events during transurethral resection were simulated in vitro. The distribution of current was measured at the loop/rollerball and in the outer metal sheath. Both an intact loop/rollerball and loop/rollerball with faulty insulation were tested. Various power outputs simulating coagulation, cutting, and vaporization were used. Data were recorded both in settings where the outer metal sheath was and was not smeared with nonconductive lubricating gel. RESULTS: Approximately 20% of the total current output was shunted to the metal sheath when an intact loop/rollerball was used. One hundred percent of the current was short-circuited to the sheath when a loop/rollerball with faulty insulation was retracted into the sheath. Little current was detectable in the nonconductive lubricating gel. We then calculated the length of time required, in various settings, to reach tissue temperature of 45 degrees C, when protein denaturation starts. The higher the power output and the smaller the contacting surface area, the more likely it is for urethral burns to occur. CONCLUSION: Our in vitro experiment showed that urethral burns secondary to stray current in the resectoscope sheath are unlikely when an intact loop is used. However, urethral burns can occur when a loop/rollerball with faulty insulation is used, especially in combination with nonconductive gel that is dispersed unevenly within the urethra.

Animals↗