Soil processes modify the composition of volatile organic compounds (VOCs) from CO2- and CH4-dominated geogenic and landfill gases: A comprehensive study

Degradation mechanisms affecting non-methane volatile organic compounds (VOCs) during gas uprising from different hypogenic sources to the surface were investigated through extensive sampling surveys in areas encompassing a high enthalpy hydrothermal system associated with active volcanism, a CH4-rich sedimentary basin and a municipal waste landfill. For a comprehensive framework, published data from medium-to-high enthalpy hydrothermal systems were also included. The investigated systems were characterised by peculiar VOC suites that reflected the conditions of the genetic environments in which temperature, contents of organic matter, and gas fugacity had a major role. Differences in VOC patterns between source (gas vents and landfill gas) and soil gases indicated VOC transformations in soil. Processes acting in soil preferentially degraded high-molecular weight alkanes with respect to the low-molecular weight ones. Alkenes and cyclics roughly behaved like alkanes. Thiophenes were degraded to a larger extent with respect to alkylated benzenes, which were more reactive than benzene. Furan appeared less degraded than its alkylated homologues. Dimethylsulfoxide was generally favoured with respect to dimethylsulfide. Limonene and camphene were relatively unstable under aerobic conditions, while α-pinene was recalcitrant. O-bearing organic compounds (i.e., aldehydes, esters, ketones, alcohols, organic acids and phenol) acted as intermediate products of the ongoing VOC degradations in soil. No evidence for the degradation of halogenated compounds and benzothiazole was observed. This study pointed out how soil degradation processes reduce hypogenic VOC emissions and the important role played by physicochemical and biological parameters on the effective VOC attenuation capacity of the soil.

CT and MR Imaging of Retroperitoneal Sarcomas: A Practical Guide for the Radiologist

Primary retroperitoneal sarcomas (RPS) represent around 10-16% of all sarcomas, with liposarcomas and leiomyosarcomas being the most common subtypes. RPS have some peculiar characteristics, imaging appearances, worse prognosis, and complications compared to other locations of sarcoma. Commonly, RPS primarily present as large masses, progressively encasing adjacent structures, causing mass effect, and complications. RPS diagnosis is often challenging, and these tumors may be overlooked; however, failure to recognize RPS characteristics leads to a worse prognosis for the patients. Surgery is the only recognized curative treatment, but the anatomical constraints of the retroperitoneum limit the ability to achieve wide resection margins; therefore, these tumors have a high rate of recurrence, and require long-term follow-up. The radiologist has an important role in the diagnosis of RPS, the definition of their extent, and their follow-up. Specific knowledge of the main imaging findings is required to reach an early diagnosis, and, ultimately, to guarantee the best patient management. This article provides an overview of the current knowledge regarding cross-sectional imaging features of patients with retroperitoneal sarcomas, presenting tips and tricks to improve imaging diagnosis of RPS.

Focal liver lesions in cirrhosis: Role of contrast-enhanced ultrasonography

Contrast-enhanced ultrasound (CEUS) represents a great innovation for the evaluation of focal liver lesions (FLLs). The main advantage of CEUS is the real-time imaging examination and the very low toxicity in patients with renal failure. Liver cirrhosis has been recognized as a major risk factor for the onset of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). HCC in liver cirrhosis develops as the last step of a complex that leads to the gradual transformation from regenerative nodule through dysplastic nodule to HCC. In patients with liver cirrhosis, a surveillance program is recommended consisting of ultrasound (US) for detecting small focal lesions. A wide spectrum of benign and malignant lesions other than HCC may be found in the cirrhotic liver and their differentiation is important to avoid errors in staging diseases that may preclude potentially curative therapies. Several published studies have explored the value of CEUS in liver cirrhosis and they have been shown to have excellent diagnostic and prognostic performances for the evaluation of non-invasive and efficient diagnosis of FLLs in patients at high risk for liver malignancies. The purpose of this article is to describe and discuss CEUS imaging findings of FLLs including HCC and ICC, all of which occur in cirrhotic livers with varying prevalence.

185 Diagnostic accuracy of dynamic stress myocardial CT perfusion as compared with invasive coronary physiology metrics in stented patients: preliminary results of the advantage II study

Aims

To compare the diagnostic performance of adenosine-stress dynamic myocardial perfusion assessed by CT (CTP) as compared with that of coronary CT angiography (CCTA) alone by using invasive fractional flow reserve (FFR) and index of microvascular resistance (IMR) as standard of reference. Diagnostic performance of CCTA for in-stent restenosis (ISR) detection is still challenging. Recently, CTP demonstrated additional specificity and diagnostic accuracy over CCTA alone in patients with previous stent implantation and suspected IRS or progression of coronary artery disease (CAD). However, no data are available in this clinical setting on the performance of CTP by using a new technique allowing for a non-invasive adjudication of regional myocardial blood flow (dynamic CTP) and to assess both macrovascular and microvascular disease status. Moreover, dynamic CTP was never compared vs. a comprehensive assessment of invasive coronary physiology (FFR and IMR).

Methods and results

We enrolled consecutive stable patients with previous coronary stenting referred for invasive coronary angiography (ICA) for clinical indication. All patients underwent dynamic stress myocardial CTP and rest CTP+CCTA by using a last generation scanner characterized by a 16-cm Z-axis coverage and fast (0.28 s) gantry rotation time. Invasive FFR and IMR were performed during ICA according to the standard practice. The diagnostic rate and diagnostic accuracy of CCTA and CTP were evaluated in a territory-based analyses vs. quantitative coronary angiography (QCA), FFR, and IMR. In 67 enrolled patients (55 men, mean age: 63.1 ± 8.2 years), the diagnostic rate (number of territories interpretable/number of territories evaluated) of CTP was significantly higher than that of CCTA (302/307 = 98.4% vs. 290/307 = 94.4%, P = 0.009). The interpretability of the combined CCTA/CTP approach was 99.7% (306/307 territories). When QCA was used as gold standard, CTP diagnostic accuracy was significantly higher than that of CCTA (84.4% vs. 80.1%, P = 0.01). When coronary physiology metrics were used as gold standard, CTP diagnostic accuracy was significantly higher than that of CCTA vs. both FFR (84.3% vs. 72.2%, P = 0.02) and IMR (83.3% vs. 70.2%, P = 0.02). The radiation exposure of CCTA+CTP was 8.7 ± 2.5 mSv.

Conclusions

In patients with coronary stents, dynamic CTP significantly improves diagnostic rate and accuracy of CCTA alone in comparison with both FFR and IMR. The non-invasive assessment of ISR is still challenging. The comprehensive assessment by cardiac CT provides anatomical combined to functional evaluation of coronary arteries in revascularized patients with good agreement with invasive physiological evaluation.

New frontiers in liver ultrasound: From mono to multi parametricity

Modern liver ultrasonography (US) has become a “one-stop shop” able to provide not only anatomic and morphologic but also functional information about vascularity, stiffness and other various liver tissue properties. Modern US techniques allow a quantitative assessment of various liver diseases. US scanning is no more limited to the visualized plane, but three-dimensional, volumetric acquisition and consequent post-processing are also possible. Further, US scan can be consistently merged and visualized in real time with Computed Tomography and Magnetic Resonance Imaging examinations. Effective and safe microbubble-based contrast agents allow a real time, dynamic study of contrast kinetic for the detection and characterization of focal liver lesions. Ultrasound can be used to guide loco-regional treatment of liver malignancies and to assess tumoral response either to interventional procedures or medical therapies. Microbubbles may also carry and deliver drugs under ultrasound exposure. US plays a crucial role in diagnosing, treating and monitoring focal and diffuse liver disease. On the basis of personal experience and literature data, this paper is aimed to review the main topics involving recent advances in the field of liver ultrasound.

Focal Pancreatic Lesions: Role of Contrast-Enhanced Ultrasonography

The introduction of contrast-enhanced ultrasonography (CEUS) has led to a significant improvement in the diagnostic accuracy of ultrasound in the characterization of a pancreatic mass. CEUS, by using a blood pool contrast agent, can provide dynamic information concerning macro- and micro-circulation of focal lesions and of normal parenchyma, without the use of ionizing radiation. On the basis of personal experience and literature data, the purpose of this article is to describe and discuss CEUS imaging findings of the main solid and cystic pancreatic lesions with varying prevalence.

Focal liver lesions: interobserver and intraobserver agreement of three-dimensional contrast-enhanced ultrasound-assisted volume measurements

PURPOSE

This study was conducted to assess the interobserver and intraobserver agreement of three-dimensional contrast-enhanced ultrasound (3D-CEUS) volume calculations of focal liver lesions (FLLs).

METHODS

Thirty-nine patients (15 men and 24 women; mean age, 55.4 years) with 39 FLLs (mean size, 3.1±1.8 cm; size range, 1 to 8 cm) prospectively underwent 3D-CEUS. Four readers calculated the volume of each lesion in an independent and blinded fashion in two separate sessions by means of a semi-automatic, commercially available proprietary software. The differences in lesion volumes (cm3) among sessions and readers were assessed using the Mann-Whitney U test and the Kruskal-Wallis test. Bland-Altman analysis was also performed. Intraclass correlation coefficients (ICCs) with 95% confidence intervals (95% CIs) were calculated. The statistical significance level was set at P<0.05.

RESULTS

Among readers, there were no statistically significant differences in the first (P=0.953) and second (P=0.592) reading sessions for volume calculations of the 39 FLLs, with almost perfect inter-reader agreement (ICC values of the first reading session, 0.996; 95% CI, 0.992 to 0.998 and ICC value of the second reading session, 0.994; 95% CI, 0.990 to 0.997, respectively). For each of the four readers, there were no significant differences in volume calculations between the two sessions (P=0.503-0.924), and the intrareader agreement was almost perfect for each reader (R1: ICC, 0.995; 95% CI, 0.991 to 0.998; R2: ICC, 0.995; 95% CI, 0.988 to 0.997; R3: ICC, 0.996; 95% CI, 0.992 to 0.998; R4: ICC, 0.985; 95% CI, 0.971 to 0.992).

CONCLUSION

3D-CEUS volume calculations provided consistent measurements across different readers with almost perfect intrareader agreement.

Volatile organic compounds (VOCs) in solid waste landfill cover soil: Chemical and isotopic composition vs. degradation processes

Landfills for solid waste disposal release to the atmosphere a large variety of volatile organic compounds (VOCs). Bacterial activity in landfill cover soils can play an important role in mitigating VOC emission. In order to evaluate the effects of degradation processes and characterize VOCs composition in landfill cover soil, gases from 60 sites and along 7 vertical profiles within the cover soil were collected for chemical and isotopic analysis at two undifferentiated urban solid waste disposal sites in Spain: (i) Pinto (Madrid) and (ii) Zurita (Fuerteventura, Canary Islands). The CO₂/CH₄ ratios and δ¹³C-CO₂ and δ¹³C-CH₄ values were controlled by either oxidation or reduction processes of landfill gas (LFG). VOCs were dominated by aromatics, alkanes and O-substituted compounds, with minor cyclics, terpenes, halogenated and S-substituted compounds. Degradation processes, depending on both (i) waste age and (ii) velocity of the uprising biogas through the soil cover, caused (i) an increase of degradation products (e.g., CO₂, O-substituted compounds) and (ii) a decrease of degradable components (e.g., CH₄, alkanes, alkylated aromatics, cyclic and S-substituted compounds). Terpenes, halogenated compounds, phenol and furans were unaffected by degradation processes and only depended on waste composition. These results highlight the fundamental role played by microbial activity in mitigating atmospheric emissions of VOCs from landfills. Nevertheless, the recalcitrant behaviour shown by compounds hazardous for health and environment remarks the importance of a correct landfill management that has to be carried out for years after the waste disposal activity is completed, since LFG emissions can persist for long time.

23-hour observation endocrine neck surgery: lessons learned from a case series of over 1700 patients

Although the surgical procedures concerning the thyroid and the parathyroid glands are considered safe, the possible occurrence of complications (mainly hematoma and hypocalcemia) limit the short stay surgery. At our institution a 23-hour-surgery with overnight hospital stay for endocrine neck surgical procedures was introduced since 2004. The present case series analyses the institutional results. Over 1913 endocrine neck surgery procedures, 1730 patients (90,2%) were managed according to this model. Among these patients, 92 suffered from hypocalcemia, 12 from airways obstruction due to the hematoma, 5 from bilateral nerve palsy. 15 more patients had unpredictable general disease compromising the short-stay surgery management. The goal of the discharge after 23 hours was achieved in 92,8% of cases with a mean hospital stay of 1,1days. The 23-hour observation with an overnight surgery is feasible and safe if the correct indications are observed. A considerable volume of specific activity is needed.

Paediatric ulcerative colitis surgery: Italian survey

BACKGROUND AND AIMS

Recent epidemiological studies showed an increase in ulcerative colitis among children, especially in its aggressive form, requiring surgical treatment. Although medical therapeutic strategies are standardized, there is still no consensus regarding indications, timing and kind of surgery. This study aimed to define the surgical management of paediatric ulcerative colitis and describe attitudes to it among paediatric surgeons.

METHODS

This was a retrospective cohort study. All national gastroenterology units were invited to participate. From January 2009 to December 2013, data on paediatric patients diagnosed with ulcerative colitis that required surgery were collected.

RESULTS

Seven units participated in the study. Seventy-one colectomies were performed (77.3% laparoscopically). Main surgical indications were a severe ulcerative colitis attack (33.8%) and no response to medical therapies (56.3%). A three-stage strategy was chosen in 71% of cases. Straight anastomosis was performed in 14% and J-pouch anastomosis in 86% of cases. A reconstructive laparoscopic approach was used in 58% of patients. Ileo-anal anastomosis was performed by the Knight-Griffen technique in 85.4% and by the pull-through technique in 9.1% of patients. Complications after colectomy, after reconstruction and after stoma closure were reported in 12.7, 19.3 and 35% of cases, respectively.

CONCLUSIONS

This study shows that there is general consensus regarding indications for surgery. The ideal surgical technique remains under debate. Laparoscopy is a procedure widely adopted for colectomy but its use in reconstructive surgery remains limited. Longer follow-up must be planned to define the quality of life of these patients.

A mini-library of TBA analogues containing 3'-3' and 5'-5' inversion of polarity sites

Several researches have been devoted to structure-activity relationship and to post-SELEX modifications of the thrombin binding aptamer (TBA), one of the first aptamers discovered by the SELEX methodology. However, no studies on TBA dealing with the effects of introduction of inversion of polarity sites have been reported yet. In this frame, we have undertaken the synthesis and the study of a mini-library composed of several TBA analogues containing a 3'-3' or a 5'-5' inversion of polarity site at different positions into the sequence. Particularly, in this article, we present preliminary results about their structural and biological properties.

Effect of the introduction of an A-residue into a quadruplex forming oligonucleotide containing a 5'-5' polarity of inversion site

Preliminary NMR studies on structure formed by sequence 3'-TGA-5'-5'-GGT-3' are described. We proposed the formation of a tetramolecular quadruplex in which strands are equivalent to each other and three G-tetrads are present. The possibility of the occurrence of an A-tetrad also is discussed.

Three-dimensional structure of the alpha-MSH-derived candidacidal peptide [Ac-CKPV]2

Previous research has shown that the immunomodulatory peptide alpha-melanocyte-stimulating hormone (alpha-MSH) and its carboxy-terminal tripeptide KPV (Lys-Pro-Val alpha-MSH11-13) have antimicrobial influences. By inserting a Cys-Cys linker between two units of KPV, we designed the dimer [Ac-CKPV]2 that showed excellent candidacidal effects in pilot tests and was the subject of further investigations. [Ac-CKPV]2 was active against azole-resistant Candida spp. Therefore, the molecule appeared a promising candidate for therapy of fungal infections and was the subject of a structural study. 1H-NMR and restrained mechanic and dynamic calculations suggest that the peptide adopts an extended backbone structure with a beta-turn-like structure. These results open a pathway to development of additional novel compounds that have candidacidal effects potentially useful against clinical infections.

Halipeptins A and B: two novel potent anti-inflammatory cyclic depsipeptides from the Vanuatu marine sponge Haliclona species

Two new metabolites, named halipeptins A and B, have been isolated from the marine sponge Haliclona sp. Their structures were determined by extensive use of one- and two-dimensional NMR experiments, mass spectrometry, and UV and IR spectroscopy. Halipeptin A is a novel 17-membered cyclic depsipeptide, consisting of five residues including two alanines (with L stereochemistry) and three new residues that appear to be previously undescribed from natural sources: 1,2-oxazetidine-4-methyl-4-carboxylic acid, 3-hydroxy-2,2,4-trimethyl-7-methoxydecanoic acid (HTMMD), and N-methyl-delta-hydroxyisoleucine. The HTMMD residue is substituted with 3-hydroxy-2,2,4-trimethyl-7-hydroxydecanoic acid in halipeptin B. Halipeptin A was found to possess very potent anti-inflammatory activity in vivo, causing about 60% inhibition of edema in mice at the dose of 300 microg/kg (i.p.).

Structural insight into human Zn(2+)-bound S100A2 from NMR and homology modeling

The S100 subfamily of EF-hand proteins is distinguished by the binding of Zn(2+) in addition to Ca(2+). In an effort to understand the role of Zn(2+) in modulating the activity of S100 proteins, we have carried out heteronuclear NMR studies of Zn(2+)-bound S100A2 and obtained near complete resonance assignments. This analysis revealed an equilibrium between multiple isoforms due to cis-trans isomerism of proline residues in flexible regions of the protein. The secondary structure of S100A2 has been determined based on the NMR chemical shift index (CSI) technique. The protein is found to possess essentially the same secondary structure found in other S100 proteins such as S100A6 and S100B. Homology models have been built based on the high resolution three-dimensional structures of other S100 proteins. The models predict two Zn(2+) binding clusters, one involving residues His17-Cys21-Cys93 and the other Cys2-His39, and with Cys86 participating in either the N-terminal or the C-terminal binding site.

Eight weeks of non-nightly use of zolpidem for primary insomnia

CONTEXT

Intermittent use (i.e., a few nights per week) of hypnotic medication is often recommended for the treatment of chronic insomnia despite an absence of efficacy and safety data using this regimen.

STUDY OBJECTIVES

To evaluate the clinical efficacy and safety of intermittent pharmacotherapy for chronic insomnia.

DESIGN AND SETTING

Randomized, double-blind, placebo-controlled, parallel groups, clinical trial at six sleep research sites.

PATIENTS

One hundred-sixty-three (115 women, 48 men; mean age 44.1+ SE. 0.9 years), DSM-IV-defined primary insomnia patients were randomized, 134 patients completed the study.

INTERVENTIONS

Eight weeks of treatment with either zolpidem 10 mg or placebo. Patients were instructed to take medication when they felt they needed it, but at least three and no more than five times per week.

MAIN OUTCOME MEASURES

Investigator and Patient Global Ratings were the primary outcome variables. Secondary measures from daily questionnaires to assess efficacy, rebound insomnia and drug taking behavior.

RESULTS

The Investigator's Global Rating indicated that intermittent use of zolpidem produced a significantly better therapeutic effect and significantly reduced insomnia severity throughout the 8-week study relative to placebo. Zolpidem was found to be effective in initiating and maintaining sleep on nights taken, as compared to placebo, based upon the Patient's Global Ratings and all subjective sleep variables. No evidence of rebound insomnia was found on nights that zolpidem was not taken. The number of nights a pill was taken did not differ between groups, nor did frequency of pill taking change in either group across the duration of the study. There were no significant effects of treatment upon quality of life or neurocognitive measures.

CONCLUSIONS

Zolpidem 10 mg is effective in treating insomnia when used intermittently, without evidence of discontinuation effects or increased frequency of pill taking.

Intravenous versus oral initial load of propafenone for conversion of recent-onset atrial fibrillation in the emergency room: a randomized trial

BACKGROUND

Non-valvular paroxysmal atrial fibrillation is a common clinical condition associated with a high risk of thromboembolism and hemodynamic problems which increase with the duration of arrhythmia. Therefore, even if arrhythmia ceases spontaneously within 24 hours in about half of the patients, a higher early conversion rate is desirable. Propafenone either by intravenous or oral load has been shown effective in conversion to sinus rhythm.

METHODS

We consecutively randomized all emergency patients with non-valvular atrial fibrillation lasting no more than 48 hours to either intravenous or oral initial load of propafenone. They all received further oral doses if still on atrial fibrillation after the initial load. Exclusion criteria were: mean ventricular rate < 65 b/min, age > 75 years, recent acute myocardial infarction, overt heart failure, conduction defects, ventricular preexcitation, thyroid dysfunction, renal or hepatic insufficiency, pregnancy, current treatment with propafenone or other antiarrhythmic drugs, and intolerance to propafenone. Primary and secondary end-points were the conversion to sinus rhythm within 12 and 48 hours of randomization respectively.

RESULTS

Ninety-seven patients were randomized to intravenous (n = 49) or oral (n = 48) treatment. Overall, sinus rhythm restoration occurred in 83.3% of patients within 12 hours and in 98.9% at 24 hours. Recovery rate resulted significantly greater for intravenous treatment at 1 and 3 hours (p < 0.001 and p = 0.001, respectively). At 6, 12 and 24 hours no significant difference between the two groups was observed (p = 0.77, p = 0.81 and p = 0.99, respectively). No patient needed treatment suspension.

CONCLUSIONS

In patients with recent-onset non-valvular atrial fibrillation treated with propafenone within 48 hours, conversion to sinus rhythm occurred in more than 80% within 12 hours. Even if intravenous initial load appears to be slightly more rapid, the oral way is easier to administer and cheaper. The choice may depend on the specific organization of the single emergency room.

Effects of petrosaspongiolide M, a novel phospholipase A2 inhibitor, on acute and chronic inflammation

The marine product petrosaspongiolide M is a novel inhibitor of phospholipase A2 (PLA2), showing selectivity for secretory PLA2 versus cytosolic PLA2, with a potency on the human synovial enzyme (group II) similar to that of manoalide. This compound was more potent than manoalide on bee venom PLA2 (group III) and had no effect on group I enzymes (Naja naja and porcine pancreatic PLA2). Inhibition of PLA2 was also observed in vivo in the zymosan-injected rat air pouch, on the secretory enzyme accumulated in the pouch exudate. Petrosaspongiolide M decreased carrageenan paw edema in mice after the oral administration of 5, 10, or 20 mg/kg. This marine metabolite (0.01-1.0 micromol/pouch) induced a dose-dependent reduction in the levels of prostaglandin (PG)E2, leukotriene B4, and tumor necrosis factor-alpha in the mouse air pouch injected with zymosan 4 h after the stimulus. It also had a weaker effect on cell migration. The inflammatory response of adjuvant arthritis was reduced by petrosaspongiolide M, which also inhibited leukotriene B4 levels in serum and PGE2 levels in paw homogenates. In contrast with indomethacin, this marine compound did not reduce PGE2 levels in stomach homogenates. Petrosaspongiolide M is a new inhibitor of secretory PLA2 in vitro and in vivo, with anti-inflammatory properties in acute and chronic inflammation.

Petrosaspongiolides M-R: new potent and selective phospholipase A2 inhibitors from the New Caledonian marine sponge Petrosaspongia nigra

Five new bioactive sesterterpenes (1-5) have been isolated from the New Caledonian marine sponge Petrosaspongia nigra Bergquist and named petrosaspongiolides M-R. Their chemical structures were determined from 1D and 2D NMR studies and MS data. All compounds inhibited different preparations of phospholipase A2 (PLA2) by irreversibly blocking these enzymes (particularly human synovial and bee venom, see Table 3), with IC50 values in the micromolar range. Interestingly, these compounds displayed a much lower activity (or no activity at all) toward porcine pancreas and Naja naja venom PLA2 enzymes. The most potent compound, 1 (IC50 1.6 and 0.6 microM for human synovial and bee venom PLA2 enzymes, respectively), was slightly more active than manoalide (6) (IC50 3.9 and 7.5 microM) under our experimental conditions. Compound 3 is more selective, inhibiting human synovial PLA2 to a greater extent than bee venom PLA2.

Severe community-acquired pneumonia: a possible role for Chlamydia pneumoniae

Between July 1992 and June 1993, 61 patients with severe community-acquired pneumonia were admitted to our semi-intensive care unit. For all patients chest X-ray, blood gas analysis while breathing room air, Gram stain and culture of bronchoaspirate, determination of acute and convalescent anti-body titers for Legionella pneumophila, Mycoplasma pneumoniae and Chlamydia pneumoniae, blood culture when body temperature was greater than 38 degrees C, and pharyngeal swab for C. pneumoniae detection by means of an indirect immunofluorescence test were obtained. Among the patients enrolled, 15 suffered from chronic obstructive pulmonary disease, 18 had serious chronic diseases, 9 were immunodeficient and 15 had cardiovascular diseases, and only 4 had no underlying disease. Etiologic diagnosis was reached in 30 cases (49%). As expected, due to the high rate of seriously ill patients, gram-negative pathogens were identified most commonly (15%), followed by Streptococcus pneumoniae (10%) and, surprisingly, by C. pneumoniae (10%). These data, showing the possible emergence of Pseudomonas aeruginosa and C. pneumoniae, warrant further studies in order to verify whether the epidemiological pattern of severe community-acquired pneumonia is actually changing.

A polygraphic study of systolic time intervals and their correlations with heart rate and workload during supine ergometry in one hundred normal subjects

The present study was designed to investigate systolic time intervals (STI) in 100 normal subjects undergoing continuous-maximal supine cycle ergometry and to search for possible linear correlations between STI (dependent variables) and heart rate, diastolic blood pressure, systolic blood pressure, age, sex, weight, and height (independent variables), by stepwise regression analysis. The only significant correlation discovered in the study was between the contractility index (isometric contraction time-ICT) and the total work produced by each participant. Exercise tolerance was limited primarily by shortening of the ICT interval, all subjects discontinuing the test when ICT reached 13.7 +/- 7 ms.

Influence of the heart rate on mean circumferential shortening velocity: echocardiographic study of 183 normal subjects

Echocardiography was used to explore the influence of independent variables (age, body surface area and heart rate) on the mean circumferential shortening velocity (MVCF) in 183 healthy subjects. Multiple stepwise regression analysis shows that heart rate is the only variable of the three just mentioned that influences MVCF. A regression equation is evolved and proposed as an index of MVCF correction for varying heart rates.

[Polygraphic study of left ventricular function in severe hepatitis cirrhosis]

Systolic time intervals have been investigated in 26 subjects with severe liver cirrhosis. The patients were subdivided as follows: 15 with alcoholic cirrhosis; 11 with post-necrotic cirrhosis. Systolic time intervals were recorded and measured according to the Weissler's method. The left ventricular ejection time was significantly shortened due to the low systemic vascular resistance, while the pre-ejection period was unchanged, denoting preserved myocardial contractility. The isometric contraction time was also significantly shortened, thus confirming a good myocardial response to increased pre-load due to hyperdynamic state. The cardiac performance as assessed by systolic time intervals, is unchanged in hepatic cirrhosis.

Evaluation of systolic time intervals in patients with angina pectoris

We have explored the systolic time intervals of 52 patients with angina pectoris at the time of their hospitalization in our wards. Our results are in close agreement with published data, essentially indicating prolongation of the preejection time and shortening of the ejection time. These alterations of systolic times can be interpreted pathophysiologically as as expressing reduced myocardial contractility. The long PEP-short LVET polygraph picture, occurring in the course of chronic ischemic heart disease, reveals the deficit of myocardial contractility at a stage of the disease at which clinical evidence of left ventricular failure is usually not yet detectable.

A polygraph study of ischemic heart disease: short-term prognosis of acute myocardial infarction based on early modifications of isometric contraction time

The authors have explored the early modifications of systolic time intervals in 90 patients hospitalized as emergency cases for acute myocardial infarction. From analysis and interpretation of the collected data they conclude that such modifications have considerable prognostic value. All patients fitting the specifications of NYHA classes I and II, but at the same time showing a shortening of the isometric contraction time to less than 39 +/- 1.4 ms turned out to constitute a high-risk group for the development of major mechanical and electrical complications in the next 2 weeks.

[Plasma and intra-erythrocyte variations in acid-base equilibrium in acute acidosis due to acetazolamide loading]

Plasma and red cell acid-base equilibrium was studied in 14 healthy subjects following the induction of acidosis by means of i.v. acetazolamide. It was found that changes in red cell values were significantly less marked than those in plasma.

[Acid-base equilibrium changes associated with acute pulmonary edema. Intra-erythrocytic findings and comparison with plasma values]

A study was made of intra-erythrocyte acid-base balance in 7 subjects with metabolic and 3 with mixed acidosis in the course of acute haemodynamic pulmonary oedema. Comparison with plasma values showed that, in metabolic acidosis, the buffers (bicarbonate) are evenly involved in the maintenance of hydrogen ion balance, whereas in mixed forms a greater demand is made on non-bicarbonate bases. Examination of this phenomenon and its quantitative evaluation are geared to intra-erythrocyte determinations of the acid-base balance, particularly to the very important B.E. index.

Is there a real treatment for stroke? Clinical and statistical comparison of different treatments in 300 patients

In the absence of universally accepted criteria for the medical treatment of stroke, we made a rigorously randomized comparative study of different treatments in 300 patients. One group of patients received only a general supportive treatment designed to ensure adequate supplies of water, electrolytes and calories, plus whatever was needed to prevent infection and correct extant associated pathology. Three other groups of patients were treated in the same way but were also given, respectively, one of the following medications: Hydergine (Sandoz) (a mixture of three ergot alkaloids), dexamethasone, and mannitol. No statistically significant difference emerged among any of the treatment groups and the reference group in terms of objective therapeutic results. The authors concluded that, at least with the dosage used in this study, none of the treatments proved more useful than conventional supportive therapy in the first 10 days after a stroke.

[Metabolic alkalosis. III. Spontaneous and experimental compensation mechanisms in plasma and erythrocytes]

Plasma and red cell acid-base balance were studied in 13 patients with metabolic alkalosis and 14 healthy subjects following the infusion of bicarbonate. Differences between the plasma and red cell patterns suggested that application of the results of plasma determinations to the body as a whole could be the cause of serious inaccuracies. Since the changes noted occurred in different combinations according to whether alkalinisation was acute or not, it is felt that cell response to a fall in (H+) varies in relation to the time available for compensation.

[Metabolic alkalosis. Relation between bicarbonate load and the behavior of blood lactic acid in the light of the intra-erythrocyte indices of the acid-base balance]

The plasma an intra-erythrocyte acid-base balance in man was studied, along with blood pyruvate and lactate levels, in acute metabolic alkalosis induced by i.v. infusion of bicarbonate. It was found that the red cell offers a satisfactory expression of the phenomena that occur in the intracellular space. The bicarbonate ion has difficulty in crossing the red cell membrane, while the production of lactate is seen as a fundamental compensation mechanism for rapid buffering of the extra base.

[Metabolic alkalosis. Compensation mechanisms in the light of new experimental data]

Changes in arterial blood and erythrocyte acid-base and electrolyte balance in the course of acute alkalinisation caused by bicarbonate loading showed that extracellular alkalosis has no significant effect on the concentration of intraerythrocyte bicarbonate concentration, though a marked increase in pH and electrolyte balance within the red cell is apparent. Erythrocyte alkalinisation may thus be seen as essentially due to the escape of H+ ions, while the entry of Na+ ions is the main device by which the law of electroneutrality is respected. The literature suggests that lactic acid offers a source of H+ ions for destruction of bicarbonate, whereas the diffusion of the ion lactate within the cell is compensated by the release of Cl-. In addition, the data now reported indicate that the red cell is a sufficiently valid model for the study of phenomena occurring within the intracellular compartment when a state of extracellular alkalinisation in created.