Comparative assessment of satellite- and drone-based vegetation indices to predict arthropod biomass in shrub-steppes.

Arthropod biomass is a key element in ecosystem functionality and a basic food item for many species. It must be estimated through traditional costly field sampling, normally at just a few sampling points. Arthropod biomass and plant productivity should be narrowly related because a large majority of arthropods are herbivorous, and others depend on these. Quantifying plant productivity with satellite or aerial vehicle imagery is an easy and fast procedure already tested and implemented in agriculture and field ecology. However, the capability of satellite or aerial vehicle imagery for quantifying arthropod biomass and its relationship with plant productivity has been scarcely addressed. Here, we used unmanned aerial vehicle (UAV) and satellite Sentinel-2 (S2) imagery to establish a relationship between plant productivity and arthropod biomass estimated through ground-truth field sampling in shrub steppes. We UAV-sampled seven plots of 47.6-72.3 ha at a 4-cm pixel resolution, subsequently downscaling spatial resolution to 50 cm resolution. In parallel, we used S2 imagery from the same and other dates and locations at 10-m spatial resolution. We related several vegetation indices (VIs) with arthropod biomass (epigeous, coprophagous, and four functional consumer groups: predatory, detritivore, phytophagous, and diverse) estimated at 41-48 sampling stations for UAV flying plots and in 67-79 sampling stations for S2. VIs derived from UAV were consistently and positively related to all arthropod biomass groups. Three out of seven and six out of seven S2-derived VIs were positively related to epigeous and coprophagous arthropod biomass, respectively. The blue normalized difference VI (BNDVI) and enhanced normalized difference VI (ENDVI) showed consistent and positive relationships with arthropod biomass, regardless of the arthropod group or spatial resolution. Our results showed that UAV and S2-VI imagery data may be viable and cost-efficient alternatives for quantifying arthropod biomass at large scales in shrub steppes. The relationship between VI and arthropod biomass is probably habitat-dependent, so future research should address this relationship and include several habitats to validate VIs as proxies of arthropod biomass.

Genetic consequences of interglacial isolation in a steppe bird.

In response to climate changes that have occurred during Pleistocene glacial cycles, taxa associated to steppe vegetation might have followed a pattern of historical evolution in which isolation and fragmentation of populations occurred during the short interglacials and expansion events occurred during the long glacial periods, in contrast to the pattern described for temperate species. Here, we use molecular genetic data to evaluate this idea in a steppe bird with Palaearctic distribution, the little bustard (Tetrax tetrax). Overall, extremely low genetic diversity and differentiation was observed among eight little bustard populations distributed in Spain and France. Mismatch distribution analyses showed that most little bustard populations expanded during cooling periods previous to, and just after, the last interglacial period (127,000-111,000 years before present), when steppe habitats were widespread across Europe. Coalescent-based methods suggested that glacial expansions have resulted in substantial admixture in Western Europe due to the existence of different interglacial refugia. Our results are consistent with a model of evolution and genetic consequences of Pleistocene cycles with low between-population genetic differentiation as a result of short-term isolation periods during interglacials and long-term exchange during glacial periods.

Clinical case report and literature review: metachronous colorectal splenic metastases.

A 52-year-old woman with a rising carcinoembryonic antigen CEA, no clinical or radiological findings, a negative colonoscopy, and a positron emission tomography (PET) scan that revealed an isolated hypermetabolic lesion in the spleen. The patient underwent splenectomy by laparoscopic surgery. The pathological study confirmed the presence of an isolated metastasis to the spleen. This case reveals the rare occurrence of isolated splenic metastases in the context of colorectal cancer and illustrates the role of PET when a patient shows a rising CEA with negative clinicoradiological studies.

Parotid gland metastasis of a breast cancer.

Parotid gland metastases from malignant tumors are extremely rare. A 61-year-old woman was diagnosed with an early breast cancer with no expression of oestrogen and progesterone receptors. Five years later the patient presented a tumour in parotid gland. After total parotidectomy, microscopic analysis of the gland demonstrated an invasive duct carcinoma (IDC) with positive expression of oestrogen receptor. The patient was treated with chemotherapy followed by complementary local radiotherapy. Diagnosis of a metastasic tumour in parotid gland poses a challenge. In our case an immunohistochemical study of oestrogen receptor was fundamental to establish a diagnosis.

[Transitional carcinoma of the ureter and ipsilateral synchronous renal cell carcinoma in hydronephrotic atrophic kidney: infrequent association]. / Carcinoma transicional de uréter y carcinoma ipsilateral sincrónico de células renales en riñón atrófico hidronefrótico: asociación infrecuente.

We report a new case of simultaneous occurrence of renal cell carcinoma and transitional cell carcinoma into ipsilateral ureter. A review of the literature to date indicates this is the 45 world-wide case and the 8 in the Spanish publications.

A comparative study of magnetic resonance cholangiography and direct cholangiography.

OBJECTIVE: Magnetic resonance cholangiopancreatography (MRCP) is a rapidly developing method for the noninvasive assessment of the biliary tree and pancreatic duct that obviates the need for contrast medium. We describe our experience with this new diagnostic imaging method in patients with obstruction of the biliary tree. We assessed both the location and cause of obstruction, and compared the results with direct cholangiography. METHODS: Between 1997 and 1998, 81 patients underwent MRCP at our facility. Two different image acquisition protocols (half-Fourier acquisition single-shot turbo spin-echo -HASTE- and rapid acquisition with relaxation enhancement -RARE-) for T2-weighted turbo spin echo sequences as well as cross-sectional fast multiplanar gradient-echo pulse (T1-weighted FL2D) and T2-weighted fast spin echo (T2 TSE) sequences were used. All patients underwent direct (either percutaneous or endoscopic retrograde) cholangiography or surgery for confirmation and/or treatment. The images obtained with MRCP were evaluated by two radiologists with expertise in biliary tree imaging who were unaware of the patient's clinical characteristics, and their diagnostic interpretations were compared with the findings obtained upon surgery or direct cholangiography. RESULTS: The sensitivity and specificity of MRCP in ruling out pathologies and detecting the presence of dilatation of the biliary tree were 100%. In assessing the level of the obstruction, sensitivity and specificity varied with location (intrahepatic/hilar, suprapancreatic, intrapancreatic or ampullary). Sensitivity in these locations was 100, 92, 69 and 86%, respectively, whereas specificity was 100, 94, 92 and 91%, respectively. In determining the cause of the obstruction, the results were variable depending on the cause: choledocholithiasis (sensitivity, 89%; specificity, 90%) malignant obstruction (sensitivity, 92%; specificity, 88%), benign stricture (sensitivity, 63%; specificity, 90%), and chronic pancreatitis (sensitivity, 50%; specificity, 99%). CONCLUSIONS: MRCP offered high diagnostic accuracy in the assessment of the occurrence and location of biliary obstruction. Sensitivity and specificity in establishing the cause varied, and were highest for choledocholithiasis and malignant obstruction. MRCP may be used instead of ERCP, which may then be reserved for patients who are likely to require surgery.

[Self-training in needle-knife sphincterotomy]. / Aprendizaje no tutelado de la esfinterotomía de aguja.

AIM: To analyze our experience in self-training in needle-knife sphincterotomy and to estimate the number of procedures necessary to reach competence in this technique. METHOD: Retrospective analysis of the first 60 needle-knife sphincterotomies performed, paying attention to success rates, the need for one or two attempts and the incidence and severity of early complications. The results were analyzed and divided into 2-year periods. The training period was subsequently determined using a qualitative method which combines the three above-mentioned criteria and sets competence level at 90%. RESULTS: Of the 60 attempted needle-knife sphincterotomies (five in Billroth-II patients), 54 (90%) were completed. The procedure was required in 20% of all the sphincterotomies completed. Needle-knife sphincterotomy was completed at the first attempt in 39 (65%) patients and complications appeared in 13 (22%), three (5%) of which were serious but not fatal. Analysis of 2 year periods showed an almost 100% increase in the total number of needle-knife sphincterotomies completed and in those completed at the first attempt, as well as a reduction in the complication rate, which subsequently stabilized at below 15%. Forty needle-knife sphincterotomies were needed to reach competence level. CONCLUSION: Needle-knife sphincterotomy can be learned without training from an endoscopist with experience in this technique. Competence can be reached after 40 procedures. Nevertheless, we propose an alternative method to our own to achieve competence in less time and with fewer complications.

Video-laparoscopic staging of gastric cancer. A prospective multicenter comparison with noninvasive techniques.

BACKGROUND: The high proportion of gastric carcinomas present in an unresectable stage, together with the emergence of multimodal treatments, increases the usefulness of objective staging methods that avoid unnecessary laparotomies. METHODS: A prospective evaluation of the accuracy of laparoscopy in the staging of 71 patients with gastric adenocarcinoma is presented. Serosal infiltration, retroperitoneal fixation, metastasis to lymph nodes, peritoneal and liver metastasis, and ascites were determined in the staging workup. Sensitivity, specificity, and predictive values were calculated and compared with those obtained with ultrasonography (US) and computed tomography (CT). RESULTS: The diagnostic accuracy of laparoscopy in the determination of resectability was 98.6%. Consequently, over 40% of patients were spared unnecessary laparotomies. Laparoscopy yielded diagnostic indices superior to US and CT for all the tumoral attributes studied. Our technique permits accurate assessment and pathologic verification of liver and the peritoneal and retroperitoneal extent of tumor invasion in the majority of patients. CONCLUSIONS: Laparoscopy in gastric adenocarcinoma is a reliable technique that provides accurate assessment of resectability and stage, thus avoiding unnecessary laparotomies in patients in whom surgical palliation is not indicated. A stepwise diagnostic workup combining imaging and minimally invasive techniques is proposed.

Epidemiology of primary sclerosing cholangitis in Spain. Spanish Association for the Study of the Liver.

The incidence of primary sclerosing cholangitis has been estimated on the basis of its frequent association with ulcerative colitis, but direct epidemiologic studies have not yet been carried out. In the current study we report a survey of clinical and epidemiological aspects of primary sclerosing cholangitis in Spain. A questionnaire was circulated to physicians in 33 hospitals throughout Spain to ascertain the number and the clinical, biochemical and immunologic characteristics of patients with primary sclerosing cholangitis from January 1, 1984 to December 31, 1988. Twenty-three centers, from 12 Spanish regions, covering a population of 19.23 million answered the questionnaire. Forty-three patients (60.5% males) with a mean age of 42.3 years (range 12 to 75 years) were seen during the 5-year period. At presentation, 16% of the cases were asymptomatic. Ulcerative colitis was present in 44.2% of cases, and one patient had Crohn's disease. The overall annual incidence ranged from 0.16 to 0.68 cases/million from 1985 to 1988, and the annual prevalence increased from 0.78 cases/million in 1984 to 2.24 cases/million in 1988. No geographical differences were found, but there was a trend to detect more cases in industrialized regions. In conclusion, there was a continuing rise in the annual incidence and prevalence of primary sclerosing cholangitis in Spain over a 5-year period.

Functional impairment of natural killer cells in active ulcerative colitis: reversion of the defective natural killer activity by interleukin 2.

We have studied the functional characteristics and clinical importance of the natural killer (NK) cytotoxicity of peripheral blood mononuclear cells (PBMNC) from patients with ulcerative colitis. Normal NK activity was observed in PBMNC from patients with inactive disease, but a pronounced decrease was found in those with active disease. Clinical change from active to inactive disease was associated with enhancement of the depressed NK activity. The impairment of NK cytotoxicity found in patients with active disese could not be ascribed to a deficient number of NK cells as the amounts of HNK-1+, CD16+ (Leu 11), and CD11b (OKM1) cells in PBMNC were within normal ranges. This defective cytotoxic PBMNC activity was normalised by short term (18 hour) incubation with recombinant interleukin 2 (rIL-2). Moreover, long term (5 day) incubation of these effector cells with rIL-2 induced strong cytotoxic activity against NK resistant and NK sensitive target cells in patients with active and inactive disease. We also found that both precursors and effectors of cytotoxic activity promoted by short term and long term incubation with rIL-2 of PBMNC from the patients showed the phenotype of NK cells (CD16+, CD3-). Taken together, these results show that active ulcerative colitis is associated with a defective function of NK cells that is found to be normal in the inactive stage of the disease. The possible pathogenic and therapeutic implications of these findings are discussed.

Efficacy of CDP-choline in the treatment of senile alterations in memory.

Alterations in membrane function may occur as a consequence of aging because of a decrease in the synthesis or an increase in the catabolism of choline and ethanolamine glycerophospholipids, leading to impairment in cognitive function. Experimental studies have shown that the administration of CDP-choline increases the total amount of phosphatidylcholine and other related phospholipids in the brain and in some cases may enhance neurotransmission. Clinical assessments and neuropsychologic tests in patients with cerebral insufficiency, chronic cerebrovascular disease, and dementia suggest that CDP-choline may improve some of the memory deficits associated with aging.

Levo-carnitine, its derivatives, and free fatty acids in serum, heart, liver, and muscle of both tumoral and alcoholic rats.

We present a comparative study of carnitine-related fatty acid metabolism in rats bearing a Yoshida sarcoma, in chronic alcoholic rats, and in control rats. Levels of levo-carnitine, acetylcarnitine, acylcarnitine, and free fatty acids were studied in serum and in different tissues--liver, heart, and skeletal muscle--of each group of rats. Chronic alcoholic rats showed high levels of free fatty acids and elevated levo-carnitine and acetylcarnitine levels relative to those of the controls. Biosynthesis of carnitine appeared to be increased, whereas fatty acid oxidation was depressed. Tumor-bearing rats also showed high levels of free fatty acids in both serum and tissues. However, levels of levo-carnitine were decreased in this group. It seems that the tumor not only utilizes the precursors of carnitine biosynthesis but also increases carnitine expenditure.

[Serum theophylline levels after oral administration in a group of asthmatic children]. / Niveles séricos de teofilina tras administración oral en un grupo de niños asmáticos.

Serum levels of theophylline were determined in 54 asthmatics children aged 3,92 +/- 2,45 years, who were taken oral theophylline at doses of 4,99 +/- 0,45 mg. The serum levels at 0 hours (9,22 +/- 4,90 mcg/ml) and at 2 hours (15,22 +/- 5,5 mcg/ml) showed a great variation, although they were taken similar doses. Two hours after ingestion, 34 patients showed levels between 10-20 mcg/ml in 10 children were less than 10 mcg/ml, and another 10 shown serum levels over 20 mcg/ml without symptoms. There was a good correlation between levels at 0 and 2 hours (p less than 0,002). These data may support the utility of doses employed. It is advisable knowing the individual response to theophylline for managing episodes of asthma in children, that can be made by only one determination 2 hours after ingestion.