Experimental evidence that intra-specific competition in seagrass meadows reduces reproductive potential in the sea urchin Paracentrotus lividus (Lamarck)

To better understand the biological controls that regulate sea urchin dynamics, we studied the effects of potential inter- and intra-specific competition for food on several biological variables of the main sea urchin in the Mediterranean (Paracentrotus lividus). We carried out a caging experiment in which we manipulated sea urchin density (natural vs. high density) and herbivorous fish (Sarpa salpa) accessibility (free access vs. exclusion) in a Posidonia oceanica meadow. No evidence of competition between fish and urchins was detected. Neither density-dependent mortality nor changes in the somatic variables were found; however, we detected that intra-specific competition affected the reproductive potential of P. lividus. The gonad index of urchins at high population densities was ca. 30% lower than that of urchins at natural densities. As a spawning event had just occurred when urchins were collected, these differences probably reflect differences in reserve content, which may compromise the following reproductive period and decrease survival in the long term, as the gonads are also used as storage organs. For the time period studied, mortality rates appeared to be independent of local densities. The results indicate that a long-term negative feedback mechanism appears to take place in P. lividus in response to increased population density.

Prevalence of obesity and abdominal obesity in the Lausanne population.

BACKGROUND: Obesity can be defined using body mass index (BMI) or waist (abdominal obesity). Little information exists regarding its prevalence and determinants in Switzerland. Hence, we assessed the levels of obesity as defined by BMI or waist circumference in a Swiss population-based sample. METHODS: Cross-sectional, population-based non-stratified random sample of 3,249 women and 2,937 men aged 35-75 years living in Lausanne, Switzerland. Overall participation rate was 41%. RESULTS: In men, the prevalences of overweight (BMI > or =25 kg/m2) and obesity (BMI > or =30 kg/m2) were 45.5% and 16.9%, respectively, higher than in women (28.3% and 14.3%, respectively). The prevalence of abdominal obesity (waist > or =102 in men and > or =88 cm in women) was higher in women than in men (30.6% vs. 23.9%). Obesity and abdominal obesity increased with age and decreased with higher educational level in both genders. In women, the prevalence of obesity was lower among former and current smokers, whereas in men the prevalence of obesity was higher in former smokers but did not differ between current and never smokers. Multivariate analysis showed age to be positively related, and education and physical activity to be negatively related with obesity and abdominal obesity in both genders, whereas differential effects of smoking were found between genders. CONCLUSION: The prevalence of abdominal obesity is higher than BMI-derived obesity in the Swiss population. Women presented with more abdominal obesity than men. The association between smoking and obesity levels appears to differ between genders.

A phase I pharmacokinetic study of hypoxic abdominal stop-flow perfusion with gemcitabine in patients with advanced pancreatic cancer and refractory malignant ascites

PURPOSE: As no curative treatment for advanced pancreatic and biliary cancer with malignant ascites exists, new modalities possibly improving the response to available chemotherapies must be explored. This phase I study assesses the feasibility, tolerability and pharmacokinetics of a regional treatment of gemcitabine administered in escalating doses by the stop-flow approach to patients with advanced abdominal malignancies (adenocarcinoma of the pancreas, n = 8, and cholangiocarcinoma of the liver, n = 1). EXPERIMENTAL DESIGN: Gemcitabine at 500, 750 and 1,125 mg/m(2) was administered to three patients at each dose level by loco-regional chemotherapy, using hypoxic abdominal stop-flow perfusion. This was achieved by an aorto-caval occlusion by balloon catheters connected to an extracorporeal circuit. Gemcitabine and its main metabolite 2',2'-difluorodeoxyuridine (dFdU) concentrations were measured by high performance liquid chromatography with UV detection in the extracorporeal circuit during the 20 min of stop-flow perfusion, and in peripheral plasma for 420 min. Blood gases were monitored during the stop-flow perfusion and hypoxia was considered stringent if two of the following endpoints were met: pH </= 7.2, pO(2) nadir ratio </=0.70 or pCO(2) peak ratio >/=1.35. The tolerability of this procedure was also assessed. RESULTS: Stringent hypoxia was achieved in four patients. Very high levels of gemcitabine were rapidly reached in the extracorporeal circuit during the 20 min of stop-flow perfusion, with C (max) levels in the abdominal circuit of 246 (+/-37%), 2,039 (+/-77%) and 4,780 (+/-7.3%) mug/ml for the three dose levels 500, 750 and 1,125 mg/m(2), respectively. These C (max) were between 13 (+/-51%) and 290 (+/-12%) times higher than those measured in the peripheral plasma. Similarly, the abdominal exposure to gemcitabine, calculated as AUC(t0-20), was between 5.5 (+/-43%) and 200 (+/-66%)-fold higher than the systemic exposure. Loco-regional exposure to gemcitabine was statistically higher in presence of stringent hypoxia (P < 0.01 for C (max) and AUC(t0-20), both normalised to the gemcitabine dose). Toxicities were acceptable considering the complexity of the procedure and were mostly hepatic; it was not possible to differentiate the respective contributions of systemic and regional exposures. A significant correlation (P < 0.05) was found between systemic C (max) of gemcitabine and the nadir of both leucocytes and neutrophils. CONCLUSIONS: Regional exposure to gemcitabine-the current standard drug for advanced adenocarcinoma of the pancreas-can be markedly enhanced using an optimised hypoxic stop-flow perfusion technique, with acceptable toxicities up to a dose of 1,125 mg/m(2). However, the activity of gemcitabine under hypoxic conditions is not as firmly established as that of other drugs such as mitomycin C, melphalan or tirapazamine. Further studies of this investigational modality, but with bioreductive drugs, are therefore warranted first to evaluate the tolerance in a phase I study and later on to assess whether it does improve the response to chemotherapy.

Treatment of ruptured abdominal aortic aneurysm, a permanent challenge or a waste of resources? Prediction of outcome using a multi-organ-dysfunction score.

OBJECTIVES: in a retrospective study, attempts have been made to identify individual organ-dysfunction risk profiles influencing the outcome after surgery for ruptured abdominal aortic aneurysms. METHODS: out of 235 patients undergoing graft replacement for abdominal aortic aneurysms, 57 (53 men, four women, mean age 72 years [s.d. 8.8]) were treated for ruptured aneurysms in a 3-year period. Forty-eight preoperative, 13 intraoperative and 34 postoperative variables were evaluated statistically. A simple multi-organ dysfunction (MOD) score was adopted. RESULTS: the perioperative mortality was 32%. Three patients died intraoperatively, four within 48 h and 11 died later. A significant influence for pre-existing risk factors was identified only for cardiovascular diseases. Multiple linear-regression analysis indicated that a haemoglobin <90 g/l, systolic blood pressure <80 mmHg and ECG signs of ischaemia at admission were highly significant risk factors. The cause of death for patients, who died more than 48 h postoperatively, was mainly MOD. All patients with a MOD score >/=4 died (n=7). These patients required 27% of the intensive-care unit (ICU) days of all patients and 72% of the ICU days of the non-survivors. CONCLUSION: patients with ruptured aortic aneurysms from treatment should not be excluded. However, a physiological scoring system after 48 h appears justifiable in order to decide on the appropriateness of continual ICU support.

Traitement des tumeurs maligne du foie par radiologie interventionnelle: techniques intra-artérielles [Interventional radiology procedures for malignancies of the liver treatment: Intraarterial procedures].

Intraarterial procedures such as chemoembolization and radioembolization aim for the palliative treatment of advanced hepatocellular carcinoma (stage BCLC B and C with tumoral portal thrombosis). The combination of hepatic intraarterial chemotherapy and systemic chemotherapy can increase the probability of curing colorectal cancer with hepatic metastases not immediately accessible to surgical treatment or percutaneous ablation.

Biodistribution of anti-CEA F(ab')2 fragments after intra-arterial and intravenous injection in patients with liver metastases due to colorectal carcinoma.

The biodistribution of simultaneous intra-arterial and intravenous injections of a radiolabelled anti-CEA MAb F(ab')2 fragment was studied in three patients with liver metastases from colorectal cancer. Identical MAb fragments, labelled with either 125I or 131I, were injected over a period of 30 min into the hepatic artery and into a peripheral vein. After 1 or 2 days, biodistribution was measured in the surgically removed metastases, normal tissue samples and blood. By tissue radioactivity counting, tumour uptake in the range 6.3-9.1% of injected dose per gram was found. Superimposable metastasis-to-blood and metastasis-to-normal liver ratios were obtained for both iodine isotopes in all three patients. The results indicate that the intra-arterial injection of MAb F(ab')2 fragments gives no measurable advantage over more convenient injections into a peripheral vein.

Competição intra-específica entre Amaranthus hybridus L. e Amaranthus viridis L.

Ensaios de competição intra-específica foram conduzidos sobre Amaranthus viridis L. e A. hybridus L., a última espécie com dois biótipos distintos, tipo verde e tipo roxo. Os três ensaios, conduzidos separadamente, utilizaram cinco densidades de sementes por vaso. Em termos gerais, as sementes germinadas prontamente foram a razão do surgimento da próxima geração, visto que estabeleceram plântulas rapidamente e estas venceram em competição. A partir de certo número de sementes semeadas (20 por vaso), o número de plantas adultas obtidas revelou-se independente do número de sementes semeadas, o que indica que a capacidade de suporte do ambiente, ao invés do tamanho do banco de sementes no solo, é a razão da regulação do tamanho populacional; a mesma observação aplica-se à produção de matéria seca. Sob condições de competição, as espécies A. hybridus - tipo verde e A. viridis produziram maior quantidade de biomassa para reprodução (22% a 34%) do que A. hybridus - tipo roxo (15% a 18%). As primeiras, portanto, revelaram-se mais estrategistas-r que a última.

Le syndrome douloureux abdominal (SDA) aux urgences: quelle analgésie [Acute abdominal pain: what about analgesia]

Acute abdominal pain tends not to be treated by surgeons and emergency physicians. However, literature has become clear that analgesics are effective and do not disturb clinical examination, diagnostic process and do not delay surgery. Thus, early treatment of acute abdominal pain is recommended. In the absence of scientific evidence, protocols must be established by each institution and validated by quality process.

Laparoscopie abdominale: possibilités et limites [Abdominal laparoscopy: an update]

Laparoscopic surgery has become a standard approach for many interventions, including oncologic surgery. Laparoscopic instruments have been developed to allow advanced surgical procedure. Imaging and computer assistance in virtual reality or robotic procedure will certainly improve access to this surgery.

Body fat distribution in white and black women: different patterns of intraabdominal and subcutaneous abdominal adipose tissue utilization with weight loss.

BACKGROUND: Intraabdominal adipose tissue (IAAT) is the body fat depot most strongly related to disease risk. Weight reduction is advocated for overweight people to reduce total body fat and IAAT, although little is known about the effect of weight loss on abdominal fat distribution in different races. OBJECTIVE: We compared the effects of diet-induced weight loss on changes in abdominal fat distribution in white and black women. DESIGN: We studied 23 white and 23 black women, similar in age and body composition, in the overweight state [mean body mass index (BMI; in kg/m(2)): 28.8] and the normal-weight state (mean BMI: 24.0) and 38 never-overweight control women (mean BMI: 23.4). We measured total body fat by using a 4-compartment model, trunk fat by using dual-energy X-ray absorptiometry, and cross-sectional areas of IAAT (at the fourth and fifth lumbar vertebrae) and subcutaneous abdominal adipose tissue (SAAT) by using computed tomography. RESULTS: Weight loss was similar in white and black women (13.1 and 12.6 kg, respectively), as were losses of total fat, trunk fat, and waist circumference. However, white women lost more IAAT (P < 0.001) and less SAAT (P < 0.03) than did black women. Fat patterns regressed toward those of their respective control groups. Changes in waist circumference correlated with changes in IAAT in white women (r = 0.54, P < 0.05) but not in black women (r = 0.19, NS). CONCLUSIONS: Despite comparable decreases in total and trunk fat, white women lost more IAAT and less SAAT than did black women. Waist circumference was not a suitable surrogate marker for tracking changes in the visceral fat compartment in black women.

Variabilidade intra e intergenotípica em uma população de híbridos entre Leucaena leucocephala e L. diversifolia

O objetivo deste trabalho foi estimar a variabilidade de algumas características morfológicas em híbridos de Leucaena leucocephala e L. diversifolia (Leguminosae). Foram estabelecidos 20 genótipos, com 30 indivíduos cada, dispostos em seis blocos casualizados. As características morfológicas analisadas foram: comprimento de folha, número de pares de folíolos e foliólulos, número de nectários extraflorais; comprimento e largura de legumes e número de sementes por legume. O menor e o maior comprimento médio de folha foram, respectivamente, 8,6 cm e 30,6 cm. A população apresentou variação de 10,7 a 53,4 pares de foliólulos por folíolo. Em número de pares de folíolos por folha o menor valor médio foi 5,6 e o maior foi 20,3. A média de um nectário extrafloral por folha foi identificada na maioria dos indivíduos. O maior valor médio de número de sementes por legume foi 24,1 e o menor 5,0. Cinco genótipos se destacaram por sua uniformidade em relação às características analisadas.

Abdominal infections in the intensive care unit: characteristics, treatment and determinants of outcome.

BACKGROUND: Abdominal infections are frequent causes of sepsis and septic shock in the intensive care unit (ICU) and are associated with adverse outcomes. We analyzed the characteristics, treatments and outcome of ICU patients with abdominal infections using data extracted from a one-day point prevalence study, the Extended Prevalence of Infection in the ICU (EPIC) II. METHODS: EPIC II included 13,796 adult patients from 1,265 ICUs in 75 countries. Infection was defined using the International Sepsis Forum criteria. Microbiological analyses were performed locally. Participating ICUs provided patient follow-up until hospital discharge or for 60 days. RESULTS: Of the 7,087 infected patients, 1,392 (19.6%) had an abdominal infection on the study day (60% male, mean age 62 ± 16 years, SAPS II score 39 ± 16, SOFA score 7.6 ± 4.6). Microbiological cultures were positive in 931 (67%) patients, most commonly Gram-negative bacteria (48.0%). Antibiotics were administered to 1366 (98.1%) patients. Patients who had been in the ICU for ≤ 2 days prior to the study day had more Escherichia coli, methicillin-sensitive Staphylococcus aureus and anaerobic isolates, and fewer enterococci than patients who had been in the ICU longer. ICU and hospital mortality rates were 29.4% and 36.3%, respectively. ICU mortality was higher in patients with abdominal infections than in those with other infections (29.4% vs. 24.4%, p < 0.001). In multivariable analysis, hematological malignancy, mechanical ventilation, cirrhosis, need for renal replacement therapy and SAPS II score were independently associated with increased mortality. CONCLUSIONS: The characteristics, microbiology and antibiotic treatment of abdominal infections in critically ill patients are diverse. Mortality in patients with isolated abdominal infections was higher than in those who had other infections.