Liver biopsy remains an important diagnostic tool in the management of liver disease. Complications, though infrequent, are potentially disastrous. Risks and discomfort can be minimized with good ...technique, although prospective data to prove the superiority of one method over another are often lacking. Image direction is preferred in all cases, as is a transjugular approach when bleeding risks are judged to be high. Bleeding is essentially a random event. Outpatient liver biopsy is appropriate in almost every instance if immediate hospitalization facilities are available. It should be more widely practiced. Liver biopsies should only be done if, after thoughtful assessment, benefits are thought to exceed risks.
The authors reviewed 23 cases of focal nodular hyperplasia and 13 cases of hepatic adenoma, all of which were confirmed pathologically. All solitary masses that exhibited normal or increased uptake ...of technetium 99m-sulfur colloid were shown to be hyperplasia; while previous criteria such as a central blood supply on angiograms or a central scar on computed tomography (CT) or ultrasound (US) scans were helpful, they were relatively infrequent. A mass that was slightly hypodense and homogeneous on a CT or US scan and highly vascular with an intense capillary stain on an angiogram was almost always hyperplasia. Acute hemorrhage within a focal hepatic tumor was common in adenoma but did not occur in hyperplasia.
Warming experiments are increasingly relied on to estimate plant responses to global climate change. For experiments to provide meaningful predictions of future responses, they should reflect the ...empirical record of responses to temperature variability and recent warming, including advances in the timing of flowering and leafing. We compared phenology (the timing of recurring life history events) in observational studies and warming experiments spanning four continents and 1,634 plant species using a common measure of temperature sensitivity (change in days per degree Celsius). We show that warming experiments underpredict advances in the timing of flowering and leafing by 8.5-fold and 4.0-fold, respectively, compared with long-term observations. For species that were common to both study types, the experimental results did not match the observational data in sign or magnitude. The observational data also showed that species that flower earliest in the spring have the highest temperature sensitivities, but this trend was not reflected in the experimental data. These significant mismatches seem to be unrelated to the study length or to the degree of manipulated warming in experiments. The discrepancy between experiments and observations, however, could arise from complex interactions among multiple drivers in the observational data, or it could arise from remediable artefacts in the experiments that result in lower irradiance and drier soils, thus dampening the phenological responses to manipulated warming. Our results introduce uncertainty into ecosystem models that are informed solely by experiments and suggest that responses to climate change that are predicted using such models should be re-evaluated.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Based on strict predefined histologic criteria, we identified 23 patients with hepatic adenoma and 41 patients with focal nodular hyperplasia seen at this institution between 1961 and 1980. Patients ...with hepatic adenoma were young and 91% were female. When a reliable history was available, 89% had used oral contraceptives; 53% presented acutely or with pain. Eleven of 11 radionuclide scans were abnormal; 15 of 15 angiograms showed a hypervascular mass with 7 of 15 showing areas of hypovascularity. Eighteen resections were performed with one operative death. Two tumors contained areas of unequivocal hepatocellular carcinoma. Fifteen of 18 patients followed for 82 +/- 11 mo were living and well and had discontinued oral contraceptives. Focal nodular hyperplasia patients were older, 88% were female, and 58% had used oral contraceptives. Their lesions were discovered accidentally. Seven of 12 radionuclide scans demonstrated voids, while 13 of 13 angiograms showed hypervascular lesions with no areas of hypovascularity. Seventeen tumors were resected. Twenty-three of 24 patients followed for 45 +/- 7 mo were living and well. One died of nonhepatic causes. Based on the findings of this review, we believe that if the clinical suspicion of hepatic adenoma or focal nodular hyperplasia is strong, elective laparotomy for diagnosis is usually the best approach. Hepatic adenoma should be resected if technically feasible. Intraoperative wedge biopsy is appropriate for focal nodular hyperplasia.
The risk of complications from percutaneous liver biopsy is low, but discomfort is common and complications require hospitalization in approximately 4% of patients. The optimal method of performing ...these biopsies is unknown. The goal of our study was to determine whether the use of ultrasonography in the biopsy room immediately prior to or during the procedure would lessen the risk of complications and to compare the safety and efficacy in obtaining tissue by use of a Trucut needle versus an automatic biopsy needle. Between 1992 and 1994, 836 patients were entered into a randomized study (489 in Rochester, MN; 347 in Barcelona, Spain). Patients were randomized immediately prior to liver biopsy into four groups: Trucut needle, or automatic biopsy needle, and with or without ultrasonography. Fisher's Exact Test and a logistic regression model were also used to assess the effect of needle and ultrasonography on the odds for complications. The four biopsy groups were well-matched at entry with respect to age, sex, underlying liver disease, hemoglobin, prothrombin time, and platelet count. The use of ultrasound was associated with a decreased rate of hospitalization for pain, hypotension, or bleeding (2 vs. 9, P < .05). No difference in safety was found between the two types of needles. The number of passes needed to obtain specimens was similar for all four groups. The average length of the specimen was slightly greater with ultrasonographic-guided biopsies (1.7 mm vs. 1.6 mm, P < .05) and with biopsies obtained using the automatic biopsy needle when compared with the Trucut needle (1.7 mm vs. 1.5 mm, P < .05), but this did not seem to be clinically important. The addition of ultrasonography reduces complications in patients undergoing percutaneous liver biopsy. The type of needle appears to offer little difference in safety or yield of diagnostic tissue. The use of ultrasonography for guidance of percutaneous liver biopsy will lead to a lower rate of complications. The value of this benefit must be weighed against the added cost of ultrasonographic guidance. (Hepatology 1996 May;23(5):1079-83)
We tested HemoQuant, a quantitative assay of fecal blood based on the fluorescence of heme-derived porphyrin, in 106 healthy volunteers, 170 patients with gastrointestinal symptoms but with normal ...diagnostic studies, 44 patients with gastrointestinal cancer, 75 patients with benign polyps, and 374 patients with a variety of other benign gastrointestinal lesions, including ulcers and erosions. In 98 per cent of the healthy volunteers, fecal hemoglobin concentrations were less than 2 mg per gram of stool. Levels were similarly low in stools from patients with symptoms and normal studies and in patients with relatively minor benign lesions. Within these groups, levels were slightly higher in those who had ingested red meat or aspirin. The fecal hemoglobin concentration was higher in patients with gastrointestinal cancer than in any other group, and 97 per cent of those with colorectal cancer had levels above 2 mg per gram. The sensitivity of HemoQuant was significantly greater than that of the guaiac test Hemoccult, particularly when heme was degraded or stools were dry. Intestinal degradation of heme to porphyrin can be measured separately by HemoQuant, and was greater when bleeding was from proximal lesions rather than distal ones. We conclude that HemoQuant is a more sensitive measure of gastrointestinal bleeding than Hemoccult, and that its capacity to measure degraded heme may be useful in indicating the anatomic site of bleeding.
In a double-blind trial, patients with type 1 diabetes and early-to-moderate diabetic kidney disease were randomly assigned to receive allopurinol, which may slow the decline in the glomerular ...filtration rate, or placebo. There were no clinically meaningful benefits of serum urate reduction on kidney outcomes with allopurinol therapy.
Visuo-spatial working memory (VSWM) for sequences is thought to be crucial for daily behaviors. Decades of research indicate that oscillations in the gamma and theta bands play important functional ...roles in the support of visuo-spatial working memory, but the vast majority of that research emphasizes measures of neural activity during memory retention. The primary aims of the present study were (1) to determine whether oscillatory dynamics in the Theta and Gamma ranges would reflect item-level sequence encoding during a computerized spatial span task, (2) to determine whether item-level sequence recall is also related to these neural oscillations, and (3) to determine the nature of potential changes to these processes in healthy cognitive aging. Results indicate that VSWM sequence encoding is related to later (∼700 ms) gamma band oscillatory dynamics and may be preserved in healthy older adults; high gamma power over midline frontal and posterior sites increased monotonically as items were added to the spatial sequence in both age groups. Item-level oscillatory dynamics during the recall of VSWM sequences were related only to theta-gamma phase amplitude coupling (PAC), which increased monotonically with serial position in both age groups. Results suggest that, despite a general decrease in frontal theta power during VSWM sequence recall in older adults, gamma band dynamics during encoding and theta-gamma PAC during retrieval play unique roles in VSWM and that the processes they reflect may be spared in healthy aging.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Nonalcoholic steatohepatitis is a poorly understood and hitherto unnamed liver disease that histologically mimics alcoholic hepatitis and that also may progress to cirrhosis. Described here are ...findings in 20 patients with nonalcoholic steatohepatitis of unknown cause. The biopsy specimens were characterized by the presence of striking fatty changes with evidence of lobular hepatitis, focal necroses with mixed inflammatory infiltrates, and, in most instances, Mallory bodies; Evidence of fibrosis was found in most specimens, and cirrhosis was diagnosed in biopsy tissue from three patients. The disease was more common in women. Most patients were moderately obese, and many had obesity-associated diseases, such as diabetes mellitus and cholelithiasis. Presence of hepatomegaly and mild abnormalities of liver function were common clinical findings. Currently, we know of no effective therapy.
PDF
