Cardiovascular changes during SCUBA diving: an underwater Doppler echocardiographic study.

AIM: Body immersion induces blood redistribution (from peripheral to intrathoracic vessels) and is a powerful autonomic stimulus (activating both parasympathetic and sympathetic systems). For these reasons, concerns have been raised about the safety of diving for subjects with previous heart disease. The aim of this study was to evaluate cardiovascular changes occurring during recreational SCUBA diving, as assessed by underwater Doppler echocardiography. METHODS: Eighteen healthy experienced divers underwent a 2D Doppler echocardiography basally, during two 15' steps of still SCUBA diving at different depths (10 m followed by 5 m) and shortly after the end of immersion. RESULTS: During dive, left ventricular (LV) diastolic volume and early left ventricular filling significantly increased (5 m vs. basal: P < 0.05 and P < 0.01, respectively), while both deceleration time of the early filling rate and late diastolic filling velocity significantly decreased (5 m and 10 m dive vs. basal: P < 0.01). LV volume increase and diastolic filling changes persisted at postdive evaluation, where a significant decrease in heart rate was also observed (P < 0.01 as compared to basal, 5-m and 10-m dive). CONCLUSION: This study documents that shallow-depth SCUBA diving induces LV enlargement and diastolic dysfunction. Direct underwater evaluation by Doppler echocardiography could be an appropriate tool for unmasking subjects at risk for underwater-related accidents.

Lung cancer in HIV-infected patients: the experience in Brescia from 1999 to 2009.

Lung cancer (LC) is the most common cancer among the non AIDS-defining malignancies in the highly active antiretroviral therapy (HAART) era. We described 23 HIV infected patients with a LC diagnosis followed in the Clinic of Tropical and Infectious Diseases of Brescia during the period of 1999-2009. All of these patients except two (n = 21, 91.3%) were cigarette smokers and all had at least one risk factor for developing cancer of the lung, or predisposing comorbidities, such as a COPD (chronic obstructive pulmonary disease) or a previous pneumonia. The median age at LC diagnosis was 53.6 years (range 21.2-71.4 years). Adenocarcinoma and squamous cell carcinoma were diagnosed in 10 cases (43.5%) respectively. In 21 subjects (91.3%) cancer was detected at stage IV with metastases. The median survival was 5.95 months. Greater intervention focused on the cessation of smoking is necessary, as well as the implementation of closer screening policies, especially in HIV-positive subjects with LC risk factors.

[Blood-borne infections in hemodialysis: facts and opinions]. / I virus a trasmissione ematica in dialidi: il parere dell'infettivolo.

The epidemiological impact of blood-borne infections (HCV, HBV and HIV) in dialysis is a major concern. In the past two decades the implementation of specific recommendations for prevention has been associated with a sharp reduction of the HBV and HCV incidence in this setting. Moreover, in recent years new therapeutic agents against these viruses were introduced, resulting in a marked improvement in clinical outcomes in subjects with normal kidney function. A collaborative effort between nephrologists and infectious disease specialists should be made to extend this improvement to chronic kidney disease patients.

[A case of community-acquired MRSA (CA-MRSA) sepsis complicated by meningoencephalitis and cerebral abscess, successfully treated with linezolid]. / Un caso di sespi da MRSA comunitario (CA-MRSA) complicata da meningoencefalite ed ascesso cerebrale trattato con successo con linezolid.

The authors describe a clinical case regarding a young female patient affected by sepsis due to methicillin-resistant Staphylococcus aureus (MRSA), associated to meningoencephalitis and cerebral abscess. The patient had no contact with hospitals in the months prior to illness and had always been healthy. She recovered thanks to linezolid therapy. The MRSA strain proved positive for Panton-Valentine leukocidin (PVL positive) and was therefore defined as community-acquired MRSA (CA-MRSA).

Cardiac function during breath-hold diving in humans: an echocardiographic study.

Breath-hold diving induces, in marine mammals, a reduction of cardiac output due to a decrease of both heart rate and stroke volume. Cardiovascular changes in humans during breath-hold diving are only partially known due to the technical difficulty of studying fully immersed subjects. Recently, a submersible echocardiograph has been developed, allowing a feasible assessment of cardiac anatomy and function of subjects during diving. Aim of the study was to evaluate, by Doppler-echocardiography, the cardiovascular changes inducedby breath-hold diving in humans. Ten male subjects were studied by Doppler echocardiography in dry conditions and during breath-hold diving at 3 m depth. In addition 14 male subjects were studied, using the same protocol, before and during breath-hold diving at 10 m depth. At 3 m depth significant reductions in heart rate (-17%), stroke volume (-17%), cardiac output (-29%), left atrial dimensions, and deceleration time of early diastolic transmitral flow (DTE) were observed. At 10 m depth similar but more pronounced changes occurred. In particular, increase in early transmitral flow velocity became significant (+33%), while DTE decreased by 34%. At both depths dimensions of right cardiac chambers remained unchanged. Breath-hold diving at shallow depth induced, in humans, cardiovascular changes qualitatively similar to those observed in natural divers such as seals. The reduced dimensions of left atrium associated to a left ventricular diastolic pattern resembling that of restrictive/constrictive heart disease, suggest that the hemodynamic effects of diving could be explained, at least in part, by a constriction exerted on the heart by the reduced chest volume and the increased blood content of the lungs. Finally, the absence of dimensional changes in the right chambers suggests that most of the pulmonary blood shift occurred before cardiac imaging.

[Prevention of nosocomial infections: surveillance based on microbiological data]. / Effetti del monitoraggio sistematico sulla prevenzione delle infezioni ospedaliere: la sorveglianza basata sui dati del laboratorio di microbiologia.

BACKGROUND: In the C. Poma Hospital of Mantua we have been using a system of continuous surveillance of nosocomial infections based on microbiological data for the past 4 years. This monitoring estimates the incidence of the microorganisms found in cultures, especially those at risk of causing nosocomial infections. MATERIALS AND METHODS: Since June 2001 microbiological data have been registered using the Mercurio-Dianoema software and elaborated by means of Microsoft Excel in order to obtain information about isolated bacteria, especially those resistant to antibiotics. RESULTS: Surveillance in "critical" wards revealed the presence of Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans in the intensive care unit in the period 2003-2005. The most frequent bacteria in hemodialysis have been coagulase-negative Staphylococci and Staphylococcus aureus, with variable methicillin resistance. CONCLUSION: The analysis of microbiological data has promoted effective measures to reduce the incidence of these bacteria (increased rules of good practice, hand washing, etc.). If nosocomial infections or high-risk microorganisms occur, assessments are carried out; monitoring of the antibiotic resistance of the bacteria is very important.

[Epidemiologic surveillance of multi-drug resistant Pseudomonas aeruginosa in Mantova Hospital (Italy)]. / Sorveglianza epidemiologica di Pseudomonas aeruginosa multiresistente nell'Ospedale di Mantova.

For the period 2002-2005 we verified and compared the data of the prevalence and resistance of Pseudomonas aeruginosa (PA) isolated in Mantova Hospital (Italy) with the data from the international database. From the first six-month period of 2004 a significant increase was found (9% vs 28.8%) in the prevalence of multi-drug resistant PA (MDR-PA). The principal wards involved were the Intensive Care Unit and the Department of Respiratory Diseases. A significant increase in resistance rates was observed for all antimicrobials tested, in particular for aztreonam, ceftazidime, ciprofloxacin, gentamycin and imipenem. The lowest dual resistance rates were observed between amikacina with piperacillin/tazobactam, while the highest were for those that included ciprofloxacin and beta-lactams (aztreonam, cefepime). In this study we confirm the importance of continuous surveillance of laboratory data and tightening local control measures for nosocomial infections in order to prevent the spread and selection of MDR-PA.

[Infection risk and personal protective devices]. / Rischio infettivo e dispositivi di protezione individuale.

The Aa discuss the evidence and recommendations for the use of personal protective equipment by health care practitioners in general care settings; the use of aprons, gowns, gloves, eye protections, face masks is valutated on the basis of an assessment of the risk of transmission of microrganisms to the patient or from the patient to health care practitioners. The primary uses of personal protective equipment are to protect staff and reduce opportunities for transmission of microrganisms in hospitals. A trend to eliminate the unnecessary wearing of aprons, gowns and masks in general care settings has evolved over the past twenty years due to the absence of evidence that they are effective.

Multiresistant Stenotrophomonas maltophilia tunneled CVC-related sepsis, treated with systemic and lock therapy.

In the last decade, a remarkable increase in the incidence of nosocomial Gram-negative infections has been observed. These pathogens represent a substantial problem in clinical practice, due to the high resistance profile of most commonly used antibiotics. This phenomenon is surely a co-factor that exposes these susceptible patients to infections caused by selected pathogens like multiresistant Gram-negative rods. A typical example is represented by VAP (ventilator-associated pneumonia) sustained by Acinetobacter spp., Pseudomonas aeruginosa, Bulkolderia cepacia. The Authors describe a case of a central venous cather (CVC)-related Stenotrophomonas maltophilia sepsis in a patient affected by solid tumor, successfully treated with systemic antibiotic therapy associated with "lock therapy". This combination was able to cure the infection, allowing the patient to continue chemotherapy and saving the in situ CVC. The surveillance of CVCs, good adherence to the protocols and guidelines and "good practice" are the cornerstones for the prevention of nosocomial infections.

Secondary mutations in the protease region of human immunodeficiency virus and virologic failure in drug-naive patients treated with protease inhibitor-based therapy.

The role of mutations in protease (PR) and reverse-transcriptase (RT) of human immunodeficiency virus (HIV) in predicting virologic failure was assessed in 248 antiretroviral-naive HIV-positive patients who began a PR inhibitor-containing antiretroviral regimen. Genotypic testing was performed on plasma samples stored before the start of therapy. Twenty-seven patients (10.9%) had mutations in the RT, 5 (2%) carried primary mutations in the PR, and 131 (52.8%) showed only secondary PR mutations. Virologic failure at week 24 occurred in 62 (25.0%) of 248 patients. There was a statistically significant correlation between virologic failure and the number of PR mutations (P= .04, chi(2) test). Mutations at codons 10 and 36 of PR (present in 39.3% and 40.0% of patients in whom treatment failed, respectively) were identified by stepwise logistic regression as the strongest predictors of virologic failure (odds ratio, 2.20; 95% confidence interval, 1.30-3.75; P= .004). If confirmed in independent studies, this result may justify the increased use of HIV genotyping in drug-naive patients requiring antiretroviral therapy.

Tolerability of twice-weekly rifabutin-isoniazid combinations versus daily isoniazid for latent tuberculosis in HIV-infected subjects: a pilot study.

The tolerability of and adherence to intermittent short-term rifabutin-isoniazid preventive treatment was assessed in subjects dually infected with Mycobacterium tuberculosis and the human immunodeficiency virus (HIV). In a randomised, open-label, phase II pilot study, 44 subjects received either rifabutin 300 mg and isoniazid 750 mg twice weekly for 3 months (group A, n = 16) or the same regimen with rifabutin at 600 mg (group B, n = 14), or isoniazid 300 mg/day for 6 months (group C, n = 14). Three, two and four subjects in groups A, B, and C, respectively, did not complete their treatment (one case of flu-like syndrome in group B; one methadone withdrawal syndrome in group A; and patient decision in two cases in group A and four in group C). Overall, adverse events were reported by four, nine, and seven subjects in groups A, B and C, respectively. Intermittent combined rifabutin + isoniazid for 3 months had lower default rates than daily standard isoniazid for 6 months. The regimen with rifabutin at 300 mg dose compared favourably to standard isoniazid, and warrants larger efficacy studies to assess its role for the prevention of latent tuberculosis in HIV-infected subjects.

Cardiac and humoral changes induced by recreational scuba diving.

The aim of this study was to evaluate the prevalence and the possible clinical relevance of circulating bubbles after a recreational scuba dive. Twenty healthy subjects (18 male, 2 female; age range 25-36 yr) underwent a Doppler-echocardiographic study in basal conditions and 1.9+/-0.2 h after a recreational scuba dive. Venous blood samples were taken just before the two ultrasonic studies to obtain leukocyte and platelet counts and plasma activity of angiotensin-converting enzyme (ACE; assumed as pulmonary endothelial damage marker). Circulating bubbles were observed in the right heart chambers of 12 subjects after the dive. The echocardiographic and humoral data were evaluated before and after diving in subjects with and without circulating bubbles. At the postdive evaluation, a significant increase in right ventricular dimensions (37.4+/-3.9 vs. 40.7+/-4.0 mm; P < 0.01) and a significant reduction of early diastolic filling velocities of both right (59.1+/-16.4 vs. 48.9+/-6.9 cm x s-(-1); P < 0.05) and left (76.2+/-9.9 vs. 67.5+/-10.2 cm x s(-1); P < 0.02) ventricle were observed in the group with circulating bubbles. In the same group, significant increases in ACE activity (92.9+/-41.1 vs. 105.9+/-41.7 U x liter(-1); P < 0.05), platelets (217+/-34 vs. 232+/-35 10(3) x microl(-1); P < 0.01), and granulocytes (3,704+/-715 x microl(-1) vs. 5,212+/-1,995 x microl(-1); P < 0.001) were observed. The bubble-free group showed only a postdive significant decrease of left ventricular early diastolic filling velocity (74+/-6.8 vs. 62.6+/-4.5 cm x s(-1); P < 0.005). These data may indicate that circulating gas bubbles are associated with cardiac changes, suggesting a right ventricular overload and an impairment of ventricular diastolic performance. Postdive humoral and hematologic changes are consistent with the hypothesis that "silent" gas bubbles may damage pulmonary endothelium and activate the reactive systems of the human body.

A randomized, double-blind trial on the use of a triple combination including nevirapine, a nonnucleoside reverse transcriptase HIV inhibitor, in antiretroviral-naive patients with advanced disease.

The immunologic and virologic activity of nevirapine in combination with two nucleosides (zidovudine [ZDV] and didanosine [ddI]) was evaluated in antiretroviral-naive patients with a CD4 count <200/mm3 or clinical AIDS. In all, 68 patients were enrolled in a 48-week double-blind, placebo-controlled trial. A group of 32 patients received ZDV + ddI + nevirapine, and 36 patients received ZDV + ddI. Primary efficacy parameters were the activity on HIV-1 RNA and on peripheral blood CD4+ cells, with differences between groups analyzed by the Wilcoxon's nonparametric two-sample test. Baseline RNA was high in both treatment groups (median values, 5.8 and 5.7 log10). RNA and CD4 responses were significantly higher with the triple combination (median RNA reductions, 2.69 versus 1.05 log10 at 24 weeks and 1.97 versus 1.20 log10 at 48 weeks; median CD4 increases, 81 versus 64 cells/mm3 at 24 weeks and 101 versus 27 cells/mm3 at 48 weeks). This study demonstrates that a triple combination of ZDV + ddI + nevirapine used as first-line regimen in antiretroviral-naive patients can induce sustained virologic and immunologic response in patients with low CD4 count or a previous diagnosis of AIDS.

Cryptococcal meningitis and intracranial tuberculoma in a patient with Waldenstrom's macroglobulinemia treated with fludarabine.

We report a patient with Waldenstrom's Macroglobulinemia who presented with cryptococcal meningitis followed by an intracranial tuberculoma during the 18 months period after termination of cytotoxic therapy with Fludarabine. Opportunistic infections due to intracellular organisms are extremely rare in the course of this malignancy and we review the predisposing factors of these infectious entities.

Successful nonoperative treatment of tuberculous spinal epidural abscess with cord compression: the role of magnetic resonance imaging.

A patient is described with a tuberculous spinal epidural abscess and signs of cord compression, who was successful treated without surgery. Magnetic resonance imaging, in addition to its role as a diagnostic tool, was helpful in monitoring the resolution of inflammation.