Prediction of Limb Salvage Following Percutaneous Vascular Intervention Using a Composite Tibial Artery Perfusion Score.

PURPOSE: To assess a novel tibial artery perfusion score (TPS) for predicting limb salvage in critical limb ischemia (CLI) patients undergoing percutaneous vascular intervention (PVI). PATIENTS AND METHODS: A consecutive cohort of 115 CLI patients undergoing PVI in 144 limbs from 2011 to 2016 was analyzed. TPS comprised a 27-point scale based on: (1) patent tibial vessels following PVI, (2) severity of calcification of the tibial arteries, (3) presence of an intact pedal arch following intervention, (4) whether or not revascularization was direct or indirect based on the target angiosome, (5) presence of angiosome blush at the completion of index intervention. Limbs were stratified into (1) High [21-27 points], (2) Medium [13-20 points], and (3) Low [0-12 points] TPS. Predictive value of TPS was evaluated using logistic regression and Cox proportional hazards models. RESULTS: The median follow-up was 15.7 months (range 0.4-69.9 months). Limb salvage in High, Medium, and Low TPS groups was 90.6%, 85.9%, and 55.6%, respectively, as freedom from the composite outcome: (1) limb complication resulting in death, (2) tibial bypass surgery, (3) above-the-knee amputation, or (4) below-the-knee amputation in patients without supratibial disease at the time of PVI. TPS was significantly associated with limb salvage defined as freedom from both the composite outcome and major amputation. CONCLUSIONS: Based on this preliminary investigation, TPS was associated with limb salvage in CLI limbs, particularly in high-risk limbs. Further validation in a prospective cohort may identify patients with high-risk limbs in need of closer surveillance and earlier reintervention. LEVEL OF EVIDENCE: Level IV, case series.

Bacterioplankton and organic carbon dynamics in the lower mesohaline chesapeake bay.

The mesohaline portion of the Chesapeake Bay is subject to annual summertime hypoxia and anoxia in waters beneath the pycnocline. This dissolved oxygen deficit is directly related to salinity-based stratification of the water column in combination with high levels of autochthonously produced organic matter and a very high abundance of metabolically active bacteria. Throughout the water column in the lower, mesohaline part of the bay, between the Potomac and Rappahannock rivers, near the southern limit of the mainstem anoxia, bacterial abundance often exceeded 10 x 10 cells per ml and bacterial production exceeded 7 x 10 cells per liter per day during summer. Bacterial biomass averaged 34% (range, 16 to 126%) of the phytoplankton biomass in summer. These values are equal to or greater than those found farther north in the bay, where the oxygen deficit is more severe. Seasonal variations in bacterial abundance and production were correlated with phytoplankton biomass (lag time, 7 to 14 days), particulate organic carbon and nitrogen, and particulate biochemical oxygen demand in spring; but during summer, they were significantly correlated only with dissolved biochemical oxygen demand. During summer, dissolved biochemical oxygen demand can account for 50 to 60% of the total biochemical oxygen demand throughout the water column and 80% in the bottom waters. There is a clear spring-summer seasonal shift in the production of organic matter and in the coupling of bacteria and autochthonous organic matter. The measurement of dissolved, microbially labile organic matter concentrations is crucial in understanding the trophic dynamics of the lower mesohaline part of the bay. The absolute levels of organic matter in the water column and the bacterial-organic carbon relationships suggest that a lower bay source of organic matter fuels the upper mesohaline bay oxygen deficits.

Acute copper and cupric ion toxicity in an estuarine microbial community.

Copper was acutely toxic to the estuarine microbial community of Middle Marshes, N.C. Under ambient water quality conditions, 10 mug of added total copper [Cu(II)] liter reduced the CFU bacterial abundance by up to 60% and inhibited the amino acid turnover rate (AATR) by as much as 30%. Copper toxicity, however, was a quantitative function of free cupric ion (Cu) activity that was not directly related to Cu(II) or ligand-bound copper. By using a nitrilotriacetic acid-cupric ion buffer to control pCu (-log Cu activity), it was found that an in situ pCu of 10.1 was bactericidal, reducing the CFU by 60%, but inhibited the AATR by only about 10%. A bacterial bioassay that was used to estimate the pCu in Cu(II)-treated Middle Marshes samples indicated that less than 0.5% of added Cu(II) was in the free cupric ion form. CFU was a more sensitive indicator of low-level copper stress than was AATR. When tested at different times, native microbial community responses to acute cupric ion stress were quantitatively quite similar even when there were large differences in bacterial abundances and in situ metabolic rates. Variations were observed in response to Cu(II) treatments at different times, but these were likely due to differences in water quality, which would quantitatively influence the distribution of copper complexes that were present. Asymptotic response curves suggest that some degree of copper resistance exists in this community. At a pCu of 8, more than 2 orders of magnitude above the minimum inhibitory level, the CFU was still 5 to 10% and the AATR was about 3% of the control values.

Chronic hepatitis: disease factors at diagnosis predictive of mortality.

PURPOSE: Chronic hepatitis is known to be a disease with substantial mortality. The purpose of this study was to identify prognostic factors in a large group of patients with chronic hepatitis. We also wanted to determine whether the aminopyrine breath test (ABT) is of additional prognostic value in evaluation of this disease. PATIENTS AND METHODS: We studied 94 patients who had had a biopsy-proven diagnosis and an ABT between June 1, 1977, and June 30, 1981. Clinical features and biochemical test results at the time of diagnosis were retrieved from medical records, and histologic severity was assessed by reviewing all liver biopsy specimens under code. Survival was determined at a mean of 60 months. Data were studied with a Cox proportional hazards model to identify predictors of mortality and to control for confounding variables. RESULTS: Cumulative mortality as of December 31, 1985, was 5 percent in chronic persistent hepatitis, 6 percent in chronic active hepatitis, 29 percent in chronic active hepatitis with bridging necrosis, and 53 percent in chronic active hepatitis with cirrhosis. Histologic severity was a predictor of death (p less than 0.005). Other predictors of mortality were disease caused by hepatitis B virus (p less than 0.005), a high alkaline phosphatase level (p less than 0.025), a low alanine aminotransaminase level (p less than 0.001), and a depressed ABT result (p less than 0.005). CONCLUSION: The results suggest that patients with chronic hepatitis with one or more of these risk factors have an increased mortality and should be followed closely for liver failure, which may necessitate medical therapy or surgical intervention.

Actinomycotic liver abscess. Case report and literature review.

A 28-year-old male with hepatic actinomycosis presented with several months of anorexia, weight loss, fever, night sweats, and mild right upper quadrant abdominal tenderness. Despite normal liver function tests, hepatic involvement was demonstrated by imaging studies. A liver biopsy and ultrasound-guided aspirate were, however, unrewarding. Laparotomy was, therefore, necessary to establish a definitive diagnosis. The patients was then successfully treated with intravenous penicillin followed by oral clindamycin. This case is presented to illustrate the diagnostic difficulties that may be encountered in such patients with hepatic actinomycosis.

Comparison of methods to measure acute metal and organometal toxicity to natural aquatic microbial communities.

Microbial communities in water from Baltimore Harbor and from the mainstem of Chesapeake Bay were examined for sensitivity to mercuric chloride, monomethyl mercury, stannic chloride, and tributyltin chloride. Acute toxicity was determined by measuring the effects of [3H]thymidine incorporation, [14C]glutamate incorporation and respiration, and viability as compared with those of controls. Minimum inhibitory concentrations were low for all metals (monomethyl mercury, less than 0.05 microgram liter-1; mercuric chloride, less than 1 microgram liter-1; tributyltin chloride, less than 5 micrograms liter-1) except stannic chloride (5 mg liter-1). In some cases, mercuric chloride and monomethyl mercury were equally toxic at comparable concentrations. The Chesapeake Bay community appeared to be slightly more sensitive to metal stress than the Baltimore Harbor community, but this was not true for all treatments or assays. For culturable bacteria the opposite result was found. Thymidine incorporation and glutamate metabolism were much more sensitive indicators of metal toxicity than was viability. To our knowledge, this is the first use of the thymidine incorporation method for ecotoxicology studies. We found it the easiest and fastest of the three methods; it is at least equal in sensitivity to metabolic measurements, and it likely measures the effects on greater portion of the natural community.

Characterization of microbial isolates from an estuarine ecosystem: relationship of hydrocarbon utilization to ambient hydrocarbon concentrations.

Water collected at 12 sites in the Neuse River estuary of North Carolina was analyzed for total viable counts on three isolation media (Trypticase soy agar [TSA], marine agar 2216, Sabouraud agar) and total hydrocarbons by fluorescence spectroscopy. Counts of 3.9 X 10(1) to 3.8 X 10(3) cells/ml were found for total heterotrophs, well within the range commonly reported for marine and estuarine waters. Generally, marine agar 2216 gave higher counts than TSA at stations with salinities greater than 6.0 mg/ml; TSA gave higher counts than marine agar 2216 at sites with salinities less than 4.0 mg/ml. The microbial species isolated on the three media agree well with those previously reported for estuarine microbial communities. Water analyses, using XAD-2 resin and fluorescence spectroscopy, revealed petroleum hydrocarbon concentrations in the range of 5 to 79 ng/ml. Representatives of the microbial species isolated from these communities were tested individually for their ability to grow using kerosene as a sole source of carbon and energy. At all but two stations, the majority of the species isolated were able to grow on hydrocarbons, indicating that this ability is widespread even in environments not subjected to high levels of hydrocarbon pollution.