A multicenter experience on the prevalence of ARMC5 mutations in patients with primary bilateral macronodular adrenal hyperplasia: from genetic characterization to clinical phenotype

ARMC5 mutations have recently been identified as a common genetic cause of primary bilateral macronodular adrenal hyperplasia (PBMAH). We aimed to assess the prevalence of ARMC5 germline mutations and correlate genotype with phenotype in a large cohort of PBMAH patients. A multicenter study was performed, collecting patients from different endocrinology units in Italy. Seventy-one PBMAH patients were screened for small mutations and large rearrangements in the ARMC5 gene: 53 were cortisol-secreting (two with a family history of adrenal hyperplasia) and 18 were non-secreting cases of PBMAH. Non-mutated and mutated patients' clinical phenotypes were compared and related to the type of mutation. A likely causative germline ARMC5 mutation was only identified in cortisol-secreting PBMAH patients (one with a family history of adrenal hyperplasia and ten apparently sporadic cases). Screening in eight first-degree relatives of three index cases revealed four carriers of an ARMC5 mutation. Evidence of a second hit at somatic level was identified in five nodules. Mutated patients had higher cortisol levels (p = 0.062), and more severe hypertension and diabetes (p < 0.05). Adrenal glands were significantly larger, with a multinodular phenotype, in the mutant group (p < 0.01). No correlation emerged between type of mutation and clinical parameters. ARMC5 mutations are frequent in cortisol-secreting PBMAH and seem to be associated with a particular pattern of the adrenal masses. Their identification may have implications for the clinical care of PBMAH cases and their relatives.

Screening for mutations in the ISL1 gene in patients with thyroid dysgenesis

CONTEXT

Congenital hypothyroidism (CH) is a common endocrine disorder with an incidence of 1:3000- 4000 newborns. In 80-85% of cases, CH is caused by defects in thyroid organogenesis, resulting in absent, ectopically located, and/or severely reduced gland, all conditions indicated as "thyroid dysgenesis" (TD). A higher prevalence of congenital heart diseases has been documented in children with CH compared to the general population. This association suggests a possible pathogenic role of genes involved in both heart and thyroid development. Among these, it can be included Isl1, a transcription factor containing a LIM homeodomain that is expressed in both thyroid and heart during morphogenesis.

OBJECTIVE

In the present study, we investigate the role of ISL1 in the pathogenesis of TD.

SETTINGS AND PATIENTS

By single stranded conformational polymorphism, we screened for mutations the entire ISL1 coding sequence in 96 patients with TD and in 96 normal controls.

RESULTS

No mutations have been found in patients and controls.

CONCLUSION

Our data indicate that, despite the relevant role of ISL1 in thyroid and heart morphogenesis, mutations in its coding region are not associated with TD in our group of patients.

Use of the antiozonant ethylenediurea (EDU) in Italy: verification of the effects of ambient ozone on crop plants and trees and investigation of EDU's mode of action

Twenty-four experiments where EDU was used to protect plants from ozone (O(3)) in Italy are reviewed. Doses of 150 and 450 ppm EDU at 2-3 week intervals were successfully applied to alleviate O(3)-caused visible injury and growth reductions in crop and forest species respectively. EDU was mainly applied as soil drench to crops and by stem injection or infusion into trees. Visible injury was delayed and reduced but not completely. In investigations on mode of action, EDU was quickly (<2h) uptaken and translocated to the leaf apoplast where it persisted long (>8 days), as it cannot move via phloem. EDU did not enter cells, suggesting it does not directly affect cell metabolism. EDU delayed senescence, did not affect photosynthesis and foliar nitrogen content, and stimulated antioxidant responses to O(3) exposure. Preliminary results suggest developing an effective soil application method for forest trees is warranted.

Mutations in TAZ/WWTR1, a co-activator of NKX2.1 and PAX8 are not a frequent cause of thyroid dysgenesis

AIM

In 80-85% of cases, congenital hypothyroidism is associated with thyroid dysgenesis (TD), but only in a small percentage of cases mutations in thyroid transcription factors (NKX2.1, PAX8, FOXE1, and NKX2.5) have been associated with the disease. Several studies demonstrated that the activity of the transcription factors can be modulated by the interaction with other proteins, such as coactivators and co-repressors, and TAZ (transcriptional co-activator with PDZ-binding motif or WWTR1) is a co-activator interacting with both NKX2.1 and PAX8. In the present study we investigate the role of TAZ in the pathogenesis of TD.

MATERIAL AND METHODS

By Single Stranded Conformational Polymorphism, we screened the entire TAZ coding sequence for mutations in 96 patients with TD and in 96 normal controls.

RESULTS

No mutations were found in patients and controls, but we found several polymorphisms in both groups. No significant differences could be demonstrated in the prevalence of the mutations between patients and controls.

CONCLUSIONS

Our data indicate that TAZ mutations are not a cause of TD in the series of patients studied.

A brief review of moxifloxacin in the treatment of elderly patients with community-acquired pneumonia (CAP)

Community-acquired pneumonia (CAP) remains a common cause of morbidity and a potentially life-threatening illness throughout the world mainly in elderly patients. Initial antibacterial treatment, usually empirical, should be as effective as possible in order to assure rapid clinical resolution and reduce high rates of hospitalization and mortality especially affecting aged patients. New fluoroquinolones with potent activity against the most important respiratory pathogens including Streptococcus pneumoniae, a key pathogen mainly in old patients with CAP, have been recently suggested by several international guidelines as monotherapy for the treatment of most CAP patient categories. Among newer derivatives, moxifloxacin, an advanced generation 8-methoxy quinolone, has demonstrated good clinical and bacteriological efficacy in large, well designed clinical trials both in adults and old patients with CAP, achieving also in aged people efficacy comparable with that of standard treatments. Good pharmacokinetic characteristics such as excellent penetration into respiratory tract tissues and fluids, optimal bioavailability, simplicity of once-daily dosing, and good tolerability, represent potential advantages of moxifloxacin over other therapies. In addition, primarily due to a shorter length of hospital stay, moxifloxacin has been shown to save costs compared with standard therapy.

Treatment of hospital-acquired pneumonia caused by methicillin-resistant Staphylococcus aureus

Nosocomial pneumonia and ventilator-assisted pneumonia may be polymicrobial and can be caused by a wide spectrum of pathogens. Potentially multidrug-resistant microorganisms often represent the 'core' pathogens of the most severe infections. Among Gram-positive pathogens, methicillin-resistant Staphylococcus aureus (MRSA) plays a key role, mainly in mechanically ventilated patients or in patients with specific risk factors. The mainstay of treatment for MRSA pneumonia has been glycopeptide antibiotics, i.e. vancomycin and, to a lesser extent, teicoplanin. However, owing to its insufficient penetration into lung compartments, vancomycin may result in therapeutic failure or slow clinical responses. Moreover, vancomycin serum levels must be monitored in order to minimise nephrotoxicity and to maximise the concentration in the lung. Finally, the emergence of staphylococci isolates with reduced susceptibility to vancomycin suggests that glycopeptides should no longer be considered as first-line antibacterial agents for Gram-positive lung infections. Among new therapeutic options, linezolid may be an appropriate choice for MRSA pulmonary infections owing to its good pharmacokinetic profile in the lung and its acceptable tolerability, especially in patients with renal insufficiency or in those receiving other nephrotoxic agents. However, to contain the increasing emergence of drug resistance among hospitalised patients, these novel antimicrobial agents should be used judiciously, restricting their use to patients not responsive to, or intolerant of, glycopeptides. Other new drugs under development appear to be promising and deserve further evaluation.

Potentially multidrug-resistant non-fermentative Gram-negative pathogens causing nosocomial pneumonia

Owing to its high morbidity and mortality, nosocomial pneumonia represents a particularly serious illness and one of the most frequent complications in ventilated patients admitted to the Intensive Care Unit. Gram-negative microorganisms, such as Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia, are the most relevant pathogens responsible for particularly difficult-to-treat nosocomial pneumonia. The intrinsic resistance of these bacteria to many antimicrobial agents and, in addition, the variety of their increasingly recognised acquired resistance mechanisms make their management in the hospital setting problematic. Antimicrobials that retain the best activity against P. aeruginosa include carbapenems, piperacillin, cefepime, ceftazidime, ciprofloxacin and certain aminoglycosides, whilst carbapenems and sulphamethoxazole/trimethoprim remain the most active agents against A. baumannii and S. maltophilia, respectively. However, the growing emergence among these microorganisms of multidrug-resistant (MDR) isolates and the severity of associated infections call for potential alternative drugs. Sulbactam alone or in combination with ampicillin may represent an acceptable option for MDR A. baumannii as well as colistin, which also covers MDR P. aeruginosa. Newer fluoroquinolones and some tetracyclines may be alternative drugs both for MDR S. maltophilia and A. baumannii. However, large-scale controlled clinical trials are needed to confirm these promising therapeutic options.

New fluoroquinolones in lower respiratory tract infections and emerging patterns of pneumococcal resistance

The increasing resistance of Streptococcus pneumoniae, the most important community respiratory pathogen, to beta-lactams and other first-line antimicrobial agents usually employed for the empirical treatment of lower respiratory tract infections has led to the inclusion, in several current guidelines, of a fluoroquinolone with improved activity against pneumococci as the first choice agent for the management of such infections. The excellent microbiological, pharmacokinetic, and pharmacodynamic characteristics of the new fluoroquinolones (levofloxacin, moxifloxacin, gemifloxacin, and gatifloxacin) have encouraged their growing use, probably contributing to the emergence of fluoroquinolone-resistant pneumococci; although pneumococcal resistance to new fluoroquinolones is currently low, there is still concern about the potential for widespread emergence of resistance to these agents if they become indiscriminately used. Levofloxacin clinical failures have already been reported in the management of patients with pneumococcal community-acquired pneumonia; development of resistance in clinical isolates of S. pneumoniae has prompted a critical reexamination of the newer fluoroquinolones to assess their potency and to preserve their activity. An understanding of the pharmacokinetic and pharmacodynamic properties, allowing selection of the most potent fluoroquinolone, will reduce the opportunity for resistance to develop. Finally, a targeted use of these agents will maintain class efficacy.

[The epidemiology of adverse reactions to nonsteroidal anti-inflammatory drugs. Nimesulide is tolerated by patients with adverse reactions to NSAIDs and modulates in man the skin response to histamine and codeine]

We evaluated the tolerance to NIM in patients with adverse reactions to NSAIDs, expressed by urticaria-angioedema, bronchial asthma or erythema polymorphous on 92 patients among which 32 atopics affected by asthma, rhinitis or contact dermatitis. Challenge test has been performed with increasing amounts of NIM per os every 2 hrs to a maximum of 100 mg/dose. The last dosage was repeated every 12 hrs for 4 times more. No reactions were observed in 86 patients (93.4%). Moreover we evaluated the efficacy of NIM in modulating pomphoid cutaneous reaction to histamine (HIS) and codeine (COD). Three subjects were prick tested with HIS and COD solutions at different concentrations (0.1 to 10 mg/ml), before and after a 5 days therapy with NIM at different dosages/kg/die. At NIM dosages of 3.7 and 2.7 mg/kg/die we observed a strong reduction of pomphoid activity of both HIS and COD. No clear effects were detected at 2.2 mg/kg/die dosage. We assume a dose-related in vivo inhibitory effect of NIM on cutaneous mast cells releasability or a direct anti-histaminic effect. We point out the possible therapeutic role of NIM in the treatment of allergic flogosis at steroid and cromon's side.

The clinical nurse specialist role in product research and development

Think about the variety of products used each day in the critical care environment. They include everything from the most sophisticated monitors to the many disposable products. Most products function very well, but when they do not, do you wish you could talk to the person who designed that product? How can your input make medical products work better? The authors describe a career opportunity open to critical care nurses, that of a clinical nurse specialist for a medical products corporation, whose job it is to influence the design and quality of medical products.