Efficacy and safety of fosfomycin plus imipenem as rescue therapy for complicated bacteremia and endocarditis due to methicillin-resistant Staphylococcus aureus: a multicenter clinical trial

BACKGROUND

There is an urgent need for alternative rescue therapies in invasive infections caused by methicillin-resistant Staphylococcus aureus (MRSA). We assessed the clinical efficacy and safety of the combination of fosfomycin and imipenem as rescue therapy for MRSA infective endocarditis and complicated bacteremia.

METHODS

The trial was conducted between 2001 and 2010 in 3 Spanish hospitals. Adult patients with complicated MRSA bacteremia or endocarditis requiring rescue therapy were eligible for the study. Treatment with fosfomycin (2 g/6 hours IV) plus imipenem (1 g/6 hours IV) was started and monitored. The primary efficacy endpoints were percentage of sterile blood cultures at 72 hours and clinical success rate assessed at the test-of-cure visit (45 days after the end of therapy).

RESULTS

The combination was administered in 12 patients with endocarditis, 2 with vascular graft infection, and 2 with complicated bacteremia. Therapy had previously failed with vancomycin in 9 patients, daptomycin in 2, and sequential antibiotics in 5. Blood cultures were negative 72 hours after the first dose of the combination in all cases. The success rate was 69%, and only 1 of 5 deaths was related to the MRSA infection. Although the combination was safe in most patients (94%), a patient with liver cirrhosis died of multiorgan failure secondary to sodium overload. There were no episodes of breakthrough bacteremia or relapse.

CONCLUSIONS

Fosfomycin plus imipenem was an effective and safe combination when used as rescue therapy for complicated MRSA bloodstream infections and deserves further clinical evaluation as initial therapy in these infections.

Seasonality and incidental sinus abnormality reporting on MRI in an Australian climate

BACKGROUND

Incidental sinus mucosal abnormalities on MRI are a common finding. This study aims to investigate seasonality and reporting of these findings.

METHODOLOGY

Prospective, cross-sectional study of adult patients presenting for neuro-radiological assessment using MRI. 173 patients were recruited over `winter` and `summer` collection periods (mean maximum temperature 14.5(deg)C and 24.3(deg)C, respectively). Patients were classified as symptomatic for rhinosinusitis according to the European Position Paper on Rhinosinusitis and Nasal Polyps 2007 definition. A modified Lund Mackay score was used to assess sinus pathology. Mucosal thickening of > 3mm was considered pathological. Radiologist reports were reviewed for mention of incidental sinus abnormalities.

RESULTS

There was an incidental rate of 58.1% overall, with significantly more sinus abnormalities in winter. Sinus abnormalities were mentioned in 8.1% of radiologist reports, half of which were in asymptomatic patients. There were significantly more sinus abnormalities amongst symptomatic patients.

CONCLUSIONS

Incidental sinus changes on MRI are a common finding and are often reported on by radiologists. However, they bear little association with symptoms. Their prevalence is influenced by season and thus their significance is greater during cooler months. Specialist referral should be reserved for symptomatic patients that have failed medical therapy.

Calbindin D-28k immunoreactivity in the temporal neocortex in patients with Alzheimer's disease

Calbindin D-28k immunoreactivity in the temporal isocortex was examined in seven patients with Alzheimer's disease (AD) and in six controls. In normal brains, calbindin D-28k-immunoreactive cells were bitufted neurons, multipolar cells with ascending dendrites and large double-bouquet cells mainly located in layers II and III. Immunoreactive fibres were seen in the molecular layer and in vertical bundles in layers III and V/VI. Calbindin D-28k immunoreactivity was reduced in patients with AD, although with differences from one patient to another. Immunoreactivity was decreased in the plexus of the molecular layer and in the vertical bundles in the cellular layers in every case. Most patients had, also, decreased immunoreactivity in the dendritic arbors. The number of calbindin D-28k-immunoreactive cells was significantly decreased in three of five patients with moderate or severe dementia, and was normal in two cases with mild dementia.

Calbindin immunoreactivity in normal human temporal neocortex

Calbindin immunoreactivity in the temporal neocortex was examined in 4 subjects with no neurological, metabolic or malignant disease. The brains were obtained between 1 and 4 h after death and rapidly fixed by perfusion with 4% paraformaldehyde through the carotid arteries, cut into slabs, cryoprotected and stored at -80 degrees C. Sections of the whole left temporal lobe obtained with a freezing microtome were processed free-floating with a well known monoclonal antibody against calbindin according to the peroxidase-antiperoxidase (PAP) method. Calbindin-immunoreactive (CaBP-ir) neurons were found to be local-circuit neurons (interneurons) mainly distributed in the upper cortical layers (layers I, II and III), and were categorized as small multipolar neurons with ascending dendrites ramifying in the molecular layer, small bitufted cells, pyramid-like cells in layer II, horizontal neurons in the molecular layer, multipolar neurons with long descending dendrites, and large double-bouquet cells, some of them exhibiting a very long dendrite with claw-shaped terminals in layer V. Less than 10% of all CaBP-ir neurons were localized in the remaining cortical layers. Pyramidal cells were only very weakly or not stained at all. In addition, CaBP-ir fibres formed a dense plexus in the molecular layer, and vertical bundles 8-10 microns thick and 500-600 microns long, separated by blank spaces 20-40 microns wide were distributed in layers III and V/VI.(ABSTRACT TRUNCATED AT 250 WORDS)

Dermatomyositis-like syndrome caused by trichinae. Report of two cases

We report 2 cases of trichinosis in which the clinical features resembled dermatomyositis. In both cases, however, the diagnosis was established histologically by demonstrating trichina larvae in the patients' muscle biopsies. Indirect immunofluorescence and counterimmunoelectrophoresis techniques were used to confirm the diagnosis serologically.

Effect of casein and whey-protein solutions on caries experience and feeding patterns of the rat

Casein (bovine milk phosphoprotein) at 2 per cent (w/v) in drinking water reduced the extent of fissure and smooth-surface caries of male Sprague-Dawley rats consuming a solid cariogenic diet. Whey protein (the non-phosphorylated protein group of bovine milk) also at 2 per cent (w/v) in the drinking water produced a smaller reduction and only of fissure caries. There was no significant difference in salivary-gland function (as determined by protein concentration), or in the amount or frequency of cariogenic diet consumed. The finding that a 2 per cent solution of whey protein reduced the extent of fissure caries in animals consuming a solid diet containing 26 per cent whey protein suggests that the anticariogenic action is mediated by the protein being in solution. These results suggest a topical anticariogenic action for dietary protein.

Atrioventricular nodal dysfunction in patients with atrial septal defect. Abnormalities of conduction and reciprocal rhythms

Electrophysiologic studies were performed in 17 unselected patients (mean age, 20 years) with atrial septal defect (ASD) of the ostium secundum type. In nine (52.9 percent) signs were found of atrioventricular (A-V) nodal dysfunction, in seven (41.1 percent) prolonged A-H interval, and in three (17.6 percent) prolonged effective refractory period of A-V node and in five (29.4 percent) A-V nodal tachycardia and reentry. Three of the four cases showed anterograde conduction (Ae-H interval) faster than retrograde conduction (H-A3 interval) during the tachycardia. In one patient with reentry a similar phenomenon was observed. In the remaining patient the conduction time was reversed (Ae-H longer than H-Ae). In two patients infrahisian and intrahisian block (first and second degree) with persistence of the tachycardia was observed. Patent or latent abnormalities in A-V node function are a frequent finding in patients with ASD. In the sinus node, any kind of significant abnormality can be found.

Fascicular block within the His bundle

The findings in a patient with complete atrioventricular block and normal morphology and duration of the QRS complex are presented. A His bundle electrogram was obtained, which led to the location of the atrioventricular block within the His bundle. A careful review of the electrocardiograms obtained during the seven years preceding the onset of complete atrioventricular block showed a QRS complex with the features of left anterior hemiblock and a progressive impairment of atrioventricular conduction. From these data, we inferred that the different degrees of atrioventricular block and the left anterior hemiblock were caused by lesions within the His bundle involving the fibers destined for the left anterior division of the left branch. After the onset of complete atrioventricular block, with the subsidiary pacemaker located in the His bundle distal to the lesions, the QRS complex became normal, indicating the integrity of the bundle branches and fasciculi. The atrial and proximal His potential intervals and those between distal His and ventricular potentials were normal.

The ascending slope of the apexcardiogram. Its relationship with angiographic determination of left ventricular function

The relationship between the ascending slope of the apexcardiogram (ACG) and direct determination of left ventricular (LV) performance as assessed angiographically by measurement of the ejection fraction (EF), mean velocity of circumferential fiber shortening (mVcF), mean normalized systolic ejection rate (MNSER), and percentage of the systolic shortening of ventricular long axis (%L), were studied in 40 patients with a wide variety of cardiac diseases. The ascending slope correlated closely and significantly (P less than 0.05) with all of them: (1) EF (r = 0.774), (2) mVcF (r = 0.776), (3) MNSER (r = 0.767) and (4) %L (r = 0.668). In a control group of 10 normal subjects, phi was determined and compared with that obtained in patients with depressed LV function, the difference being statistically significant (P less than 0.01). Other noninvasive indices derived from simultaneous phono-mechano-cardiographic readings were also studied. The calibrated ACG did not correlate with any of the hemodynamic indices; however the calibrated carotidogram did correlate with the peak systolic aortic pressure (r = 0.503). The ratio preejection period/left ventricular ejection time correlated significantly, but less than previously reported with the EF (r = 0.574). We conclude that the value of phi leads to additional evidence supporting the use of quantitative ACG as a noninvasive measure of LV performance in patients with cardiac disease.

Anterograde and retrograde bradycardiac block in the His-Purkinje system. Finding in a patient with acute myocardial infarction

A patient with an acute inferior myocardial infarction developed a complete atrioventricular block and intermitent periods of atrioventricular conduction with QRS complexes showing right bundle branch block associated with left anterior hemiblock. Recordings of the His bundle electrogram showed that the atrioventricular block was infrahisian and that in periods of resumed atrioventricular conduction, the His-ventricle (H-V) interval was long. Ventricular escape beats showed concealed conduction to the atrioventricular node. Anterograde atrioventricular conduction was always resumed through the left posterior division when the preceding division when the preceding intervals between ventricular escape beats and the atrium (V-A intervals) were shorter than 580 msec. The same phenomenon occurred with right ventricular pacing. A retrograde His potential could be observed. Retrograde conduction of ventricular escape beats and ventricular paced beats was blocked if the H-V interval and the interval between the His bundle and the ventricular paced beat (H-V interval) were long (more than 600 msec and 550 msec, respectively). The existence of an intermittent anterograde and retrograde bradycardiac infrahisian block was inferred from the previously mentioned data; a fixed retrograde atrial nodal block was also present.

Bradycardia-dependent interatrial block with retrograde left atrial activation

A patient with a peculiar interatrial block is reported. The electrocardiogram showed a short PR interval and negative P waves in II, III, and aVF, which were preceded, 0-07 s earlier, by another positive P wave present in the right praecordial leads which were absent in the limb leads. From the study with His bundle electrograms, high right atrial electrograms, and bipolar oesophageal electrocardiograms, it could be proved that atrioventricular, His-Purkinje, and right intra-atrial conduction were normal, and that P waves recorded in limb leads represented left atrial depolarization; whereas the ones in the right praecordial leads corresponded to right atrial activation. The vectorial analysis from both P waves and atrial potentials showed that the left atrium was activated in a retrograde fashion, because of an interatrial block. This block was bradycardia dependent and it disappeared in the cycles shorter than 800 ms.