Invasive mould disease in haematologic patients: comparison between fusariosis and aspergillosis.

OBJECTIVES: To compare the epidemiology, clinical presentation, diagnosis, treatment, and outcome of haematologic patients with invasive aspergillosis (IA) or invasive fusariosis (IF). METHODS: We retrospectively reviewed the charts of 36 patients with IA and 26 with IF diagnosed between 2006 and 2017 in haematologic patients, and compared baseline characteristics, coexisting exposures, clinical manifestations, treatment, and the outcome. RESULTS: Fever was more frequent in IF (96.2% vs. 63.9%, p 0.003), whereas pneumonia (88.9% vs. 50.0%, p 0.001) and sinusitis (63.9% vs. 38.5%, p 0.048) were more frequent in IA. Skin lesions and positive blood cultures occurred exclusively in patients with IF. Among patients with pneumonia, the halo sign was more frequent in IA (62.5% vs. 23.1%, p 0.02). Serum galactomannan was positive in 88.6% of patients with IA and in 73.3% with IF (p 0.18), with no differences in the median number of positive tests and galactomannan values. Positive serum galactomannan plus lung infiltrates was the predominant clinical presentation in IA and occurred in four of 13 patients with IF and lung involvement. The 30-day survival was 77.7% in IA and 46.1% in IF (p 0.01). CONCLUSIONS: IA and IF share the same epidemiologic scenario but different clinical presentations in the majority of cases, with disease in the airways in IA, and fever, metastatic skin lesions, and positive blood cultures in IF. However, a substantial proportion of patients with IF present with a clinical picture similar to IA, with fever, lung infiltrates, and positive serum galactomannan.

Predictors of fat-free mass loss 1 year after laparoscopic sleeve gastrectomy.

PURPOSE: Laparoscopic sleeve gastrectomy (LSG) is one of the most frequently performed bariatric surgery interventions because of its safety and efficacy. Nevertheless, concerns have been raised on its detrimental effect on patient nutritional state that can ultimately lead to the loss of fat-free mass (FFM). There is interest in identifying predictors for the early identification of patients at risk of this highly unwanted adverse because they could benefit of nutritional preventive interventions. Therefore, we investigated whether anthropometric parameters, body composition or resting energy expenditure (REE) measured before surgery could predict FFM loss 1 year after LSG. METHODS: Study design was retrospective observational. We retrieved data on body weight, BMI, body composition and REE before and 1 year after LSG from the medical files of 36 patients operated on by LSG at our institutions. Simple regression, the Oldham's method and multilevel analysis were used to identify predictors of FFM loss. RESULTS: Averaged percentage FFM loss 1 year after LSG was 17.0 ± 7.7% with significant differences between sexes (20.8 ± 6.6 in males and 12.2 ± 6.1% in females, p < 0.001). FFM loss was strongly predicted by pre-surgery FFM and this effect persisted also after correcting for the contribution of sex. CONCLUSIONS: High FFM values before surgery predict a more severe FFM loss after LSG. This factor could also account for the higher FFM loss in men than in women. Our finding could help in the early identification of patient requiring a nutritional support after LSG.

Potential Trace Metal Co-Limitation Controls on N2 Fixation and [Formula: see text] Uptake in Lakes with Varying Trophic Status.

The response of N2 fixation and [Formula: see text] uptake to environmental conditions and nutrient enrichment experiments in three western U.S. lake systems was studied (eutrophic Clear Lake; mesotrophic Walker Lake; oligotrophic Lake Tahoe). We tested the effect of additions of bioactive trace metals molybdenum as Mo(V) and iron (Fe) as well as phosphate (P), N2 fixation, [Formula: see text], carbon (C) fixation, chlorophyll a (Chla), and bacterial cell counts under both natural conditions and in mesocosm experiments. We found distinct background N2 fixation and [Formula: see text] uptake rates: highest at Clear Lake (N2 fixation: 44.7 ± 1.8 nmol N L(-1) h(-1)), intermediate at Walker Lake (N2 fixation: 1.7 ± 1.1 nmol N L(-1) h(-1); [Formula: see text] uptake: 113 ± 37 nmol N L(-1) h(-1)), and lowest at Lake Tahoe (N2 fixation: 0.1 ± 0.07 nmol N L(-1) h(-1); [Formula: see text] uptake: 37.2 ± 10.0 nmol N L(-1) h(-1)). N2 fixation was stimulated above control values with the addition of Fe and Pin Clear Lake (up to 50 and 63%, respectively); with Mo(V), Fe, and P in Walker Lake (up to 121, 990, and 85%, respectively); and with Mo(V) and P in Lake Tahoe (up to 475 and 21%, respectively). [Formula: see text] uptake showed the highest stimulation in Lake Tahoe during September 2010, with the addition of P and Mo(V) (∼84% for both). High responses to Mo(V) additions were also observed at some sites for C fixation (Lake Tahoe: 141%), Chla (Walker Lake: 54% and Clear Lake: 102%), and bacterial cell counts (Lake Tahoe: 61%). Overall our results suggest that co-limitation of nutrients is probably a common feature in lakes, and that some trace metals may play a crucial role in limiting N2 fixation and [Formula: see text] uptake activity, though primarily in non-eutrophic lakes.

Urinary excretion of 5-hydroxy-3-indoleacetic acid in dystimic/depressed, adult obese women: what correlations to hepatic steatosis?

The synthesis of serotonin at CNS level is influenced by diet. Moreover, insulin resistance is associated with lower serotonin levels. Visceral obesity, strictly linked to hepatic steatosis is specifically associated with mild to severe somatic affective-depressive symptom clusters. Previous data support the view that depression involves serotonergic systems, reflecting low levels of urinary 5- hydroxy-3-indoleacetic acid (5-HIAA). The 24-h urinary excretion of 5-HIAA was evaluated in 76 dystimic/depressed, obese/overweight females, divided into two groups, i.e., on a hyper-caloric diet, associated with a life style characterized by leisure time sedentary behavior (LTSB, 35 women), or on a normo-caloric diet, assisted by program-based strategies aimed at promoting physical activity participation (PAP, 41 women). Beck Depression Inventory (BDI) was carried out to score the severity of dystimia/depression. Anthropometric measures, metabolic indices, severity of hepatic steatosis at sonography and HOMA were studied. Urinary levels of 5-HIAA in controls and PAP groups were comparable with a great overlap, while in the LTSB group the urinary excretion of 5-HIAA was significantly reduced in respect to that of the PAP group and obviously compared to that of the control group, 3.4±1.4 mg/L versus 6.2±2.7 mg/L and 6.4±2.6 mg/L, respectively, ANOVA test, P= 0.001. Among metabolic indices, cholesterol, HDL-cholesterol, triglycerides and uric acid were not able to predict urinary concentrations of 5-HIAA, which were not associated with hepatic steatosis; vice versa, ferritin levels, and mainly HOMA values, were independent predictors of the urinary excretion of 5-HIAA (ß=0.235 and 0.45, respectively). Dystimia/depression severity was negatively predicted by urinary 5-HIAA levels in the sense that the highest BDI values were forecast by the lowest values of urinary 5-HIAA (ß= -0.72).The importance of measuring the 24-h urinary excretion of 5-HIAA in follow-ups could rely on a method simultaneously mirroring the well-being status, the adherence to physical activity, which leads to improved insulin sensitivity, and the eating habits acquired by dystimic/depressed overweight/obese patients. In contrast, the significance of the urinary 5-HIAA is reduced in evaluating the severity of hepatic steatosis, likely because it is a structured process.

Circulating levels of cytochrome C, gamma-glutamyl transferase, triglycerides and unconjugated bilirubin in overweight/obese patients with non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease, characterized by hepatocyte apoptosis, is distinct in fatty liver and non-alcoholic steatohepatitis, the more severe form. Apoptotic cell death is caspase-dependent and associated with mitochondrial membrane depolarization and cytochrome c release. Adhering to the hypothesis that the exposure of hepatocytes to free fatty acids, resulting in increased ROS production and mitochondrial damage, is balanced by the presence of antioxidant substances, circulating levels of gamma-glutamyl transferase, cytochrome c, triglycerides and unconjugated bilirubin were explored in patients suffering from non-alcoholic fatty liver disease with different severity. One hundred and eighty-six consecutive patients who presented recent ultrasound feature of bright liver without any liver disease of known origin were enrolled, eighty-nine of whom underwent liver biopsy. Forty-five subjects were allocated on the basis of histology in fatty liver group while 44 patients formed the group with non-alcoholic steatohepatitis. A cohort of 27 young, lean, apparently healthy individuals was selected as control group. The levels of gamma-glutamyl transferase were normal or slightly increased, while unconjugated bilirubin concentrations were elevated in all the spectra of non-alcoholic fatty liver disease. Comparing the present results with relevant findings from other studies dealing with diseases characterized by apoptosis, we did not find high circulating levels of cytochrome c in non-alcoholic fatty liver disease. What is more, our patients, categorized as suffering from simple fatty liver or from the more severe non-alcoholic steatohepatitis, had similar levels of cytochrome c and gamma-glutamyl transferase, p=0.19 and 0.11. Serum triglycerides were higher in patients with non-alcoholic fatty liver disease than in the healthy group, p=0.001. These findings likely reflect a balance between oxidative stress and anti-oxidant response rather than a lack of reliability of cytochrome c as a reliable biomarker of mitochondrial damage.

Hypolithic communities: important nitrogen sources in Antarctic desert soils.

Hypolithic microbial communities (i.e. cryptic microbial assemblages found on the undersides of translucent rocks) are major contributors of carbon input into the oligotrophic hyper-arid desert mineral soils of the Eastern Antarctic Dry Valleys. Here we demonstrate, for the first time, that hypolithic microbial communities possess both the genetic capacity for nitrogen fixation (i.e. the presence of nifH genes) and the ability to catalyse acetylene reduction, an accepted proxy for dinitrogen fixation. An estimate of the total contribution of these communities suggests that hypolithic communities are important contributors to fixed nitrogen budgets in Antarctic desert soils.

Effects of voriconazole on tacrolimus metabolism in a kidney transplant recipient.

Infection occurs frequently in the organ transplant recipients during the post-transplant period because of immunosuppression. Therefore, prophylactic antimicrobial agents are often used. The azole antifungals, widely prescribed prophylactically, are known to have many drug-drug interactions. This report presents a case of drug-drug interaction between voriconazole and tacrolimus in a kidney transplant recipient. Voriconazole treatment led to a dramatic increase in tacrolimus concentration that required its discontinuation in spite of the manufacturer's guidelines that recommend a reduction of tacrolimus dosage by one-third. The present drug-drug interaction can be attributed to a strong inhibitory effect on cytochrome P450-3A4 activity by voriconazole. When voriconazole and tacrolimus are coadministered, close monitoring of tacrolimus blood levels is recommended as the rule-of-thumb reduction of tacrolimus dose by one-third may not be satisfactory.

Long-term assessment of plasma lipids in transplant recipients treated with tacrolimus in relation to fatty liver.

Immunosuppression has improved graft and recipient survival in transplantation but is associated with possible adverse effects including cardiovascular diseases. The impact of tacrolimus on the lipidic profile has been debated for several years. Twenty-nine kidney transplant recipients on tacrolimus treatment were monitored for six years, and multiple laboratory parameters investigating the lipid asset, as well as glucose profile, were carried out. Tacrolimus has been responsible for significant changes in plasma lipid concentrations only for the first six months, but not for the remaining time of observation. Similarly, in the same periods, glycemic imbalance was highlighted. The liver enzyme activity showed a modest derangement during the tacrolimus treatment, suggesting the presence of lipid accumulation in the liver. Fatty liver reversed in the long term follow-up. Tacrolimus, although it is not a completely safe option in the first months of the immunosuppressive protocols in organ transplanted recipients, still retains a certain role in the long-term post-transplantation immunosuppressive approach with high cardiovascular risks.

Screening for tuberculosis on admission to highly endemic prisons? The case of Rio de Janeiro State prisons.

SETTING: Rio de Janeiro (RJ) State prisons, where tuberculosis (TB) is highly endemic. OBJECTIVE: To measure TB prevalence, identify risk factors and ascertain the most appropriate screening method among inmates of the RJ prisons. DESIGN: Systematic chest X-rays (CXRs) were performed in 1696 male inmates of three RJ prisons. Inmates were selected for sputum examination and culture if their CXRs showed evidence of any pulmonary, pleural or mediastinal abnormality. TB diagnosis was based on bacteriological results or, if bacteriological results were negative, on response to TB treatment. RESULTS: TB prevalence was 2.7% (46/1696), and 32/46 cases (69%) were bacteriologically confirmed, including 19 smear-positive cases. CXR lesions were extensive in 43% of cases. In the logistic regression model, TB-associated variables were being illiterate (adjusted OR 2.10, 95%CI 1.02-4.34), cough >or=3 weeks (aOR 2.85, 95%CI 1.54-5.27), history of TB treatment (aOR 3.61, 95%CI 1.76-7.39), and living in Rio City suburbs (aOR 4.54, 95%CI 1.02-20.07) and in Rio City (aOR 5.48, 95%CI 1.29-23.33). A screening based on cough >or=3 weeks followed by sputum smear examination would have identified only 9 of the 46 cases. CONCLUSION: These results call for screening on admission to prison based, if feasible, on CXR, and demonstrate the urgent need to improve detention conditions and medical assistance in police remand cells.

Does spleen volume play a role in patients with HCV-related chronic hepatitis?

As the lymphotropism of hepatitis C virus (HCV) has already been ascertained, and in the light of the fact that the immune defense system is an organized network composed of functionally interrelated tissues, this study was carried out to verify the possible involvement of spleen in HCV-related chronic hepatitis. In this cross-sectional study we measured spleen longitudinal diameter by ultrasound, beta2-microglobulin serum levels and splenic artery resistivity index (SARI) by Doppler in 51 patients treated with standard combined (Peg-Interferon plus Ribavirin) antiviral therapy. Thirty-three patients (17 females) completed the regimen and were compared to 31 controls (16 females). The mean basal values of spleen longitudinal diameter were higher in patients with chronic hepatitis than in controls, i.e., 116 mm (9.4) versus 102.7 mm (9.3), P = 0.0001. In the same patients a significant trend towards increased spleen longitudinal diameter was found after antiviral therapy, independently of the stage of HCV-related chronic hepatitis. The median values of the beta2-microglobulin concentrations were not significantly higher in the patients with HCV-related chronic hepatitis compared to controls, i.e., 1.3 (0.5-2.6) versus 1 (0.6-1.4), P = 0.16, although during the course of therapy they were significantly increased. SARI values of HCV-related chronic hepatitis patients were different from those of controls, but were unvaried compared to values at the end of treatment. Neither spleen measurements nor serum beta2-microglobulin levels were able to predict therapeutic response to antiviral therapy. A stimulation/expansion of lymphoid tissue was found in patients with HCV-related chronic hepatitis. Such evidence raises the question whether physicians should continue to prescribe antiviral therapy in non-responders and supports the use of a new scheme (SLD plus beta2-MG) to diagnose this ongoing, apparently reversible, but nevertheless dangerous immunologic process.

Quantification of sirolimus and everolimus by immunoassay techniques: test specificity and cross-reactivity evaluation.

The possible cross-reactivity of immunoassays with structurally-related drugs was investigated. Innofluor Certican (FPIA) calibrators were measured by using IMx Sirolimus assay (MEIA) and MEIA Sirolimus calibrators were analysed by using FPIA Certican assay. Drug concentrations were measured in 95 and 100 samples from renal transplanted patients (RTP) on sirolimus or everolimus treatment by using immunoassays and LC/ESI-MSMS. A high cross-reactivity was found both for MEIA and FPIA. High correlation degrees, confirmed by the Bland-Altman and the Eksborg tests, were found between drug concentrations measured in real samples by both immunoassays (r = 0.909 and r = 0.970, respectively). LC/ESI-MSMS analysis of samples containing sirolimus showed no positivity for everolimus. Similarly, samples from patients on treatment with everolimus resulted negative as far as regards sirolimus. MEIA and FPIA could be considered mutually reliable and accurate alternatives for the specific-drug immunoassay. It should be noticed that in patients switching from one drug to the other unreal overestimation of the blood levels of the current administered immunosuppressant can occur.

Amazon River enhances diazotrophy and carbon sequestration in the tropical North Atlantic Ocean.

The fresh water discharged by large rivers such as the Amazon is transported hundreds to thousands of kilometers away from the coast by surface plumes. The nutrients delivered by these river plumes contribute to enhanced primary production in the ocean, and the sinking flux of this new production results in carbon sequestration. Here, we report that the Amazon River plume supports N(2) fixation far from the mouth and provides important pathways for sequestration of atmospheric CO(2) in the western tropical North Atlantic (WTNA). We calculate that the sinking of carbon fixed by diazotrophs in the plume sequesters 1.7 Tmol of C annually, in addition to the sequestration of 0.6 Tmol of C yr(-1) of the new production supported by NO(3) delivered by the river. These processes revise our current understanding that the tropical North Atlantic is a source of 2.5 Tmol of C to the atmosphere [Mikaloff-Fletcher SE, et al. (2007) Inverse estimates of the oceanic sources and sinks of natural CO(2) and the implied oceanic carbon transport. Global Biogeochem Cycles 21, doi:10.1029/2006GB002751]. The enhancement of N(2) fixation and consequent C sequestration by tropical rivers appears to be a global phenomenon that is likely to be influenced by anthropogenic activity and climate change.

Stability of sirolimus and everolimus measured by immunoassay techniques in whole blood samples from kidney transplant patients.

The measurement of blood concentration of immunosuppressive drugs is strongly recommended because of the narrow therapeutic range. An important aspect in the therapeutic monitoring of a drug is its possible degradation. This paper is aimed at investigating the stability of two widely-used immunosuppressants, sirolimus and everolimus. Short (storage at 30 degrees C for 3 or 7 days) and long term (storage at -20 degrees C for 0-90 days with a single freeze-thaw cycle) stability of sirolimus and everolimus in whole blood samples from kidney transplant patients were examined by using MEIA and FPIA. Sirolimus and everolimus samples stored at 30 degrees C in light for up to a week showed a decrement in concentration of 5.2 percent and 6.1 percent, respectively. Our findings on long term stability for both sirolimus and everolimus highlight the possibility of storing samples at -20 degrees C for up to 90 days, without the need to use lower storage temperatures. The results have important implications for patients living far from laboratories where drug concentration is measured or when the storing of blood samples is needed for pharmacokinetic studies.

Impacts of atmospheric anthropogenic nitrogen on the open ocean.

Increasing quantities of atmospheric anthropogenic fixed nitrogen entering the open ocean could account for up to about a third of the ocean's external (nonrecycled) nitrogen supply and up to approximately 3% of the annual new marine biological production, approximately 0.3 petagram of carbon per year. This input could account for the production of up to approximately 1.6 teragrams of nitrous oxide (N2O) per year. Although approximately 10% of the ocean's drawdown of atmospheric anthropogenic carbon dioxide may result from this atmospheric nitrogen fertilization, leading to a decrease in radiative forcing, up to about two-thirds of this amount may be offset by the increase in N2O emissions. The effects of increasing atmospheric nitrogen deposition are expected to continue to grow in the future.

Could the depression of obese patients suffering from chronic hepatitis C be temporarily improved?

Depression is an usual finding in patients suffering from chronic hepatitis C. Development of moderate to severe depressive symptoms occurs frequently during pegylated interferon/ribavirin treatment and is generally predicted by baseline depression scores. Furthermore, the obese patients have been found to be twice as likely to suffer from anxiety, impaired social interaction, and depression when compared with the no obese population. In order to evaluate the efficacy of a pharmacological treatment of depression, 68 obese patients with chronic hepatitis C, under or not antiviral therapy, were selected and enrolled into this open, controlled pilot study. Our population was divided in two groups: 'on Selective Serotonin Reuptake Inhibitors plus support', with individual titration of medication to adequate side-effects, including thirty seven patients, and 'on only support', involving thirty one patients. Both groups were well balanced for gender, age and antiviral treatment. The selected patients had, at entry, a Beck Depression Inventory score of 24.5 +/- 8.1 (mean +/- SD). Therapeutic successful outcomes (a decreased score of >or= 10 units compared to the baseline) were statistically more frequent in antidepressant drug-treated group (P = 0.005); they were well predicted by dose of Selective Serotonin Reuptake Inhibitors. Thirty five percent of patients were non-responder to Selective Serotonin Reuptake Inhibitors. The drug tolerability was good. Nearly twenty percent of patients were responder to only support.

Acute pulmonary coccidioidomycosis: CT findings from 15 patients.

The aim of this study was to describe the CT scan abnormalities in 15 patients with acute pulmonary coccidioidomycosis. Retrospective analysis of chest CT scans from 15 patients with acute pulmonary coccidioidomycosis was performed. The final diagnosis included the finding of Coccidioides immitis in mycology and/or histopathology, complemented by serology. Two radiologists evaluated the CT scans to study the type, size, profusion and localization of the findings. The final decisions were defined by consensus. CT scans showed multiple bilateral nodules in 13 patients and solitary nodules associated with consolidation in 2 cases. The nodules had ill-defined contours, ranging from 0.5 cm to 3.0 cm in diameter, which were predominant in the lower lobes in 11 cases. Cavitation of nodules was observed in 13 cases and coalescence in 7. Nodule-associated abnormalities were found in 13 cases, comprising interlobular septal thickening (n = 7) and consolidations (n = 6). Other abnormalities included lymph node enlargement (n = 6) and small pleural effusion (n = 2). In conclusion, the main CT finding in patients with acute coccidioidomycosis was that of multiple nodules (0.5-3.0 cm) at the lungs bases; a significant proportion of the remaining cases also showed other abnormalities. A diagnosis of coccidioidomycosis must be considered in patients with multiple lung nodules that are either in, or have recently been transported to, areas of endemic mycosis.

Rhodococcus equi pneumonia in AIDS: high-resolution CT findings in five patients.

The aim of this study was to describe the high-resolution CT scan findings in five patients with AIDS and pulmonary infection due to Rhodococcus equi. The study included five patients with AIDS and proven R. equi infection. The CT scans were reviewed by two observers. The patients included four men and one woman ranging from 39 years to 49 years in age (mean 42 years). The findings included areas of consolidation (n=5) with single (n=1) or multiple cavitation (n=4), ground-glass opacities (n=5), centrilobular nodules (n=3), small centrilobular nodular opacities (n=3) and "tree in bud" opacities (n=3). None of the patients had pleural effusion or lymph node enlargement. The most common high-resolution CT manifestations of R. equi infection consist of areas of consolidation with cavitation, ground-glass opacities, nodules and a tree-in-bud pattern.

Prevalence of pulmonary tuberculosis and comparative evaluation of screening strategies in a Brazilian prison.

SETTING: A prison (1171 male inmates) in Rio de Janeiro, Brazil. OBJECTIVES: To determine the prevalence of active pulmonary tuberculosis (TB) and to assess the performance of several screening strategies. DESIGN: In a cross-sectional study, all inmates underwent chest radiographic screening. Subjects with abnormal findings underwent sputum smear examination and sputum culture. Taking this strategy as the reference, we assessed three targeted screening strategies to identify TB suspects: Strategy 1: cough >3 weeks; Strategy 2: WHO score > or = 5; Strategy 3: presence of at least one potentially TB-related symptom. RESULTS: The prevalence of TB cases was 4.6% (48/1052) and 2.7% for definite TB cases. If TB suspects identified by targeted screening had sputum smear examination alone, 37 (86.0%) of the 43 cases would have been missed by Strategy 1, 34/43 (79.1%) by Strategy 2 and 34/43 (79.1%) by Strategy 3. If TB suspects had both sputum smear examination and, for smear-negative subjects, chest radiography, respectively 28/43 (65.1%), 18/43 (41.9%) and 13/43 (30.2%) of cases would have been missed. CONCLUSION: All three targeted screening strategies were unreliable. Given the importance of early TB diagnosis in overcrowded and highly endemic settings, routine radiography-based screening may be warranted.

Nitrogen-fixing phylotypes of Chesapeake Bay and Neuse River estuary sediments.

Sediments often exhibit low rates of nitrogen fixation, despite the presence of elevated concentrations of inorganic nitrogen. The organisms that potentially fix nitrogen in sediments have not previously been identified. Amplification of nifH genes with degenerate primers was used to assess the diversity of diazotrophs in two distinct sediment systems, anoxic muds of Chesapeake Bay and shallow surficial sediments of the Neuse River. Phylogenetic analysis revealed that sequences obtained from mid-Chesapeake Bay, which receive high organic loading and are highly reducing, clustered closely with each other and with known anaerobic microorganisms, suggesting a low abundance of aerobic or facultative diazotrophs in these sediments. Sulfate reduction dominates in the surface, but methanogenesis becomes more important with depth. A thin (<1 cm) oxidized layer is present only in the spring. No archaeal nifH sequences were obtained from Chesapeake Bay. Sequences of nifH amplified from surficial sediments of the Neuse River were distant from Chesapeake Bay sequences and included nif phylotypes related to sequences previously reported from marine mats and the Spartina rhizosphere. Differences in environmental site characteristics appear to select for different types of sediment diazotrophs, which is reflected in the phylogenetic composition of amplified nifH sequences.

[Buruli ulcer. A case report]. / L'ulcera di Buruli. Caso clinico.

The authors report a case of skin infection, Buruli ulcer, which is widespread in several parts of Africa: Ghana, Uganda, Ivory Coast, Senegal and most central African countries. This infection is caused by Mycobacterium ulcerans which belongs to the non-tubercular species Mycobacterium. It resembles Mycobacterium tuberculosis in colour and morphology, but differs in its speed of growth, its nutritional requirements, its capacity to produce pigments with enzymatic activities, its heat sensitivity and its resistance to anti-tubercular agents. Mycobacterium infection follows the percutaneous inoculation of the latter and appears as a painless, erythematous nodule that develops central necrosis and ulceration. Initially, the lesion appears as skin necrosis leading to the ulceration of the dermis and epidermis. The histological lesion shows a coagulative necrosis of the deep dermis and epidermis with destruction of the nerves and blood vessels; interstitial edema is also present. Healing is accompanied by a granulomatous response and the affected area is generally covered by a depressed scar. The authors initially treated the case in question using a conservative approach. A gel (Intrasite Gel) was used whose properties allowed the destruction of necrotic tissue present on the ulcer bed and the stimulation of granulation tissue formation. The layer of gel was in turn covered with a triple layer of polyurethane which enabled the humidity of the lesion to be maintained constant, thus promoting healing and acting as a barrier against external germs. This treatment enabled the skin lesion to be completely sterilised in about 30 days using new dressings every 3 days. Surgical treatment then led to complete healing after a further 20 days.