P643 A case of Fabry cardiomyopathy refractory to enzyme replacement therapy; the importance of early diagnosis and treatment in Fabry cardiomyopathy

A 56-year-old male was referred in order to identify Fabry disease after his older brother was confirmed as Fabry disease of cardiac variant type. He had been treated with hypertrophic cardiomyopathy (HCMP) five years ago. He didn’t have a history of hypertension. Blood pressure was 118/65 mmHg and pulse rate was 75 beats per minute. Serum creatinine was 1.07 mg/dl and estimated glomerular filtration rate was 75.2 ml/min. Cardiac enzymes including CK-MB and troponin-T were normal. There was no proteinuria on urinalysis. A 12-leads electrocardiogram revealed normal sinus rhythm with severe left ventricular hypertrophy (LVH) and strain pattern. Transthoracic echocardiogram (TTE) showed diffuse severe concentric hypertrophy of the left ventricle (LV) of an average ventricular wall thickness of 17 mm with normal systolic function (left ventricular ejection fraction (LVEF), 56%). TTE also revealed left ventricular outflow tract obstruction with systolic anterior motion of mitral valve. Right ventricle (RV) was also hypertrophied (RV free wall thickness, 7mm). Also, echocardiography revealed findings of diastolic dysfunction; left atrial enlargement, mitral inflow of a pseudo-normal pattern on pulsed wave Doppler image and an increased left ventricular filling pressure on tissue Doppler image (E/e’=20). Cardiac magnetic resonance imaging (MRI) revealed diffuse LV and RV hypertrophy and preserved LV systolic function with hypokinesia of mid-septal LV wall. Delayed hyper-enhancement (DHE) was not found within entire myocardium. A coronary CT angiography was performed because of regional wall motion abnormality but did not show any significant stenoses. He was confirmed as Fabry disease with the same genetic mutation as his brother. He did not present symptoms and signs of any other organs besides only myocardial hypertrophy. He received enzyme replacement therapy (ERT) with intravenous agalsidase-beta every other week via outpatient department for 3 years. Recently, TTE was performed and showed diffuse severe concentric LVH of an average ventricular wall thickness increased to 19 mm despite regularly ERT. Focal intramural and subepicardial DHE was newly developed at LV basal lateral and septal wall on cardiac MRI. Neutralizing antibody against agalsidase -beta was not found in serum.

Fabry disease of cardiac variant type can be delayed in diagnostic aspect because of absence of typical symptoms and signs. Despite the absence of neutralizing antibody, ERT did not prevent both further myocardial hypertrophy and myocardial fibrosis in patient with advanced myocardial hypertrophy caused by delayed diagnosis of Fabry disease. Suspicion of Fabry disease through detailed history taking including family history in patients with diffuse ventricular hypertrophy on an echocardiography can lead to early diagnosis and treatment and can result in improvement in a clinical outcome.

Evaluation of the utility of abdominal CT scans in the diagnosis, management, outcome and information given at discharge of patients with non-traumatic acute abdominal pain

OBJECTIVES

The role of CT imaging in the diagnosis and management of acute abdominal pain is well established, but its utility is limited in a minority of cases. The aim of this study was to quantify the degree to which radiological and clinical findings differ. Interobserver variability in CT reporting was also assessed.

METHODS

Clinical data and CT reports were analysed retrospectively for any discrepancies by comparing CT diagnosis, clinical diagnosis as stated on the discharge summary and final diagnosis (based on consensus review of all information). Blinded review of all CT imaging was performed to determine interobserver variability.

RESULTS

120 consecutive scans fulfilled the inclusion criteria (114 patients; 79 women; mean age 55 years). The correct clinical diagnosis was made in 87.5% of cases based on CT findings. The lack of intravenous contrast limited diagnostic interpretation in 6 of the 15 discrepant cases. CT was unable to define early inflammatory changes in three patients and early caecal carcinoma in one. A right paraduodenal internal hernia was difficult to detect in another patient. Interobserver agreement was 93%, but with a low kappa value of 0.27. A paradox exists due to an imbalance in the positive and negative agreement of 96% and 31%, respectively.

CONCLUSIONS

The utility of CT imaging in the diagnosis and management of patients presenting with acute abdominal pain is confirmed, but is limited in a minority of cases where poor negative interobserver agreement exists. Good communication to the reporting radiologist of the relevant patient history and clinical question becomes important.

Broadband ground-plane cloak

The possibility of cloaking an object from detection by electromagnetic waves has recently become a topic of considerable interest. The design of a cloak uses transformation optics, in which a conformal coordinate transformation is applied to Maxwell's equations to obtain a spatially distributed set of constitutive parameters that define the cloak. Here, we present an experimental realization of a cloak design that conceals a perturbation on a flat conducting plane, under which an object can be hidden. To match the complex spatial distribution of the required constitutive parameters, we constructed a metamaterial consisting of thousands of elements, the geometry of each element determined by an automated design process. The ground-plane cloak can be realized with the use of nonresonant metamaterial elements, resulting in a structure having a broad operational bandwidth (covering the range of 13 to 16 gigahertz in our experiment) and exhibiting extremely low loss. Our experimental results indicate that this type of cloak should scale well toward optical wavelengths.

Mechanistic scheme and effect of "extended sigh" as a recruitment maneuver in patients with acute respiratory distress syndrome: a preliminary study

OBJECTIVE

To devise a new form of sigh ("extended sigh") capable of providing a sufficient recruiting pressure x time, and to test it as a recruitment maneuver in patients with acute respiratory distress syndrome.

DESIGN

Prospective uncontrolled clinical trial.

SETTING

Medical intensive care unit of a university-affiliated hospital.

PATIENTS

Twenty consecutive patients diagnosed with acute respiratory distress syndrome (18 men, 2 women, age 59 +/- 10 yrs).

INTERVENTIONS

From baseline settings of tidal volume (Vt) 8 mL/kg and positive end-expiratory pressure (PEEP) 10 cm H2O on volume control mode with the high pressure limit at 40 cm H2O, the Vt-PEEP values were changed to 6-15, 4-20, and 2-25, each step being 30 secs (inflation phase). After Vt-PEEP 2-25, the mode was switched to continuous positive airway pressure of 30 cm H2O for a duration of 30 secs (pause), after which the baseline setting was resumed following the reverse sequence of inflation (deflation phase). This extended sigh was performed twice with 1 min of baseline ventilation between.

MEASUREMENTS AND RESULTS

Airway pressures and hemodynamic parameters were traced at each step during the extended sigh. Arterial blood gases and physiologic parameters were determined before the extended sigh (pre-extended sigh), at 5 mins after two extended sighs (post-extended sigh), and then every 15 mins for 1 hr. In our average patient, the recruiting pressure x time of the inflation phase was estimated to be 32.8-35.4 cm H2O x 90 secs. Compared with the inflation phase, inspiratory pause pressure of the deflation phase was lower at Vt-PEEP 6-15 (28.9 +/- 2.7 cm H2O vs. 27.3 +/- 2.8 cm H2O) and 4-20 (31.8 +/- 2.9 cm H2O vs. 31.1 +/- 2.9 cm H2O; both p <.05). Compared with pre-extended sigh, Pao2 (81.5 +/- 15.3 mm Hg vs. 104.8 +/- 25.0 mm Hg; p <.001) and static respiratory compliance both increased post-extended sigh (27.9 +/- 7.9 mL/cm H2O vs. 30.2 +/- 9.7 mL/cm H2O; p =.009). Improvement in these parameters was sustained above pre-extended sigh for the duration of the study. Major hemodynamic or respiratory complications were not noted during the study.

CONCLUSION

We present a new form of sigh (i.e., extended sigh) capable of achieving an augmented recruiting pressure x time through a prolonged inflation on a gradually increased end-expiratory pressure. In view of the sustained effect and absence of major complications in our patients, extended sigh could be a useful recruitment maneuver in acute respiratory distress syndrome.

A case of endobronchial actinomycosis

Actinomycosis is an infectious disease caused by certain Actinomyces species. Actinomyces are Gram-positive, non-spore forming organisms characterized by obligate or facultative anaerobic rods that normally inhabit anaerobic niches of the human oral cavity. Cervicofacial, abdominal, pelvic and thoracic infections of Actinomyces are not uncommon, but endobronchial actinomycosis is rarely reported. Endobronchial actinomycosis can be misdiagnosed as unresolving pneumonia, endobronchial lipoma or malignancies. Endobronchial actinomycosis should be included in the differential diagnosis of any endobronchial mass. We report a case of a 43-year-old man who presented with a productive cough and pulmonary consolidation at the right lower lobe on chest radiograph. Fiberoptic bronchoscopy revealed obstruction of the right superior segment of the lower bronchus with an exophytic endobronchial mass. Endobronchial actinomycosis was confirmed by demonstration of sulfur granules in the bronchoscopic biopsy of the mass. Intravenous administration of penicillin G followed by oral amoxacillin/clavulanic acid therapy for 3 months resulted in improving symptoms. Infiltrative consolidation on the chest X-ray was markedly decreased.

Microtubule-affinity regulating kinase (MARK) is tightly associated with neurofibrillary tangles in Alzheimer brain: a fluorescence resonance energy transfer study

Paired helical filaments, the main structural components of the neurofibrillary tangles in Alzheimer disease, consist of phosphorylated tau protein. Because the levels and degree of phosphorylation are significantly higher in paired helical filament (PHF)-derived tau than in normal adult tau, and because phosphorylation of tau severely disrupts microtubule stability, it is postulated that tau phosphorylation is an important step in PHF formation. The kinases and/or phosphatases that act in vivo to help induce such a pathological state of tau, however, are not yet known. In this study we implicate the non-proline directed kinase MARK in PHF-tau phosphorylation, by virtue of its close intermolecular association with the phosphorylated Ser262 epitope on PHF-tau as assessed by fluorescence resonance energy transfer. Moreover, because this tight enzyme-substrate association is observed in neurofibrillary tangles in Alzheimer tissue, we suggest that PHF-tau phosphorylation may occur to some extent on assembled PHF filaments.

Respiratory and haemodynamic effects of the prone position at two different levels of PEEP in a canine acute lung injury model

This study was designed to examine whether the oxygenation response in the prone position differs in magnitude depending on the level of positive end-expiratory pressure (PEEP) applied in the supine position, and whether cardiac output (CO) increases in the prone position. In seven supine dogs, acute lung injury was established by saline lavage (arterial oxygen tension (Pa,O2)/inspiratory oxygen fraction (FI,O2) 17.8+/-9.6 kPa (134+/-72 mmHg)), and inflection point (Pflex) of the respiratory system was measured (6.6+/-1.4 cmH2O). Pa,O2/FI,O2 and CO of the supine and prone positions were obtained under the application of low PEEP and then under optimal PEEP (2 cmH2O below and above Pflex, respectively). The net increase in Pa,O2/FI,O2 by prone positioning was greater at low PEEP (27.3+/-12.0 kPa (205+/-90 mmHg)) than at optimal PEEP (4.4+/-13.0 kPa (33+/-98 mmHg)) (p=0.006). CO decreased significantly with optimal PEEP in the supine position (2.4+/-0.5 versus 3.1+/-0.4 L x min(-1) at baseline, p<0.001), and increased to 3.4+/-0.6 and 3.6+/-0.7 L x min(-1) in the prone position at 5 min and 30 min, respectively (both p=0.018). When the dogs were turned supine at optimal PEEP, CO again decreased (2.4+/-0.5 L x min(-1), p<0.001). In conclusion, the prone position augmented the effect of relatively low positive end-expiratory pressure on oxygenation, and attenuated the haemodynamic impairment of relatively high positive end-expiratory pressure in a canine acute lung injury model.

Aequorea green fluorescent protein: simultaneous analysis of wild-type and blue-fluorescing mutant by flow cytometry

Aequorea green fluorescent protein (GFP) has been expressed in a variety of cell lines and host organisms. A recent report (Heim et al.: Proc Natl Acad Sci USA 91:12501-12504, 1994) has documented that a GFP mutant with a single amino acid substitution (tyrosine 66 to histidine; Y66H-GFP) elicits altered spectral properties. Whereas wild-type GFP emits with a maximum at approximately 509 nm (green fluorescence), Y66H-GFP fluoresces with a maximum at approximately 448 nm (blue fluorescence). In this study we employed available argon and krypton ion laser lines to investigate the impact of laser excitation wavelength on the detection of Y66H-GEP by flow cytometry. Using transiently transfected 293 cells, a cellular subpopulation with elevated blue fluorescence was detectable with excitation at 407 nm, but not with ultraviolet (UV), 458 nm, or 488 nm excitation. The blue-fluorescing cells were further documented to express Y66H-GFP by immunoblot analysis of sorted cells. Finally, we demonstrated the simultaneous analysis of both wild-type and Y66H-GFP in cotransfected 293 cells using 407 nm excitation while collecting blue fluorescence at 460 +/- 20 nm (Y66H-GFP) and green fluorescence at 525 +/- 25 nm (wild-type GFP). These studies illustrate the potential for assessing differential gene expression by simultaneously analyzing multiple GFP species with multiparameter flow cytometry.

Aequorea green fluorescent protein analysis by flow cytometry

The isolation and expression of the cDNA for the green fluorescent protein (GFP) from the bioluminescent jellyfish Aequorea victoria has highlighted its potential use as a marker for gene expression in a variety of cell types (Chalfie et al.: Science 263: 802-805, 1994). The longer wavelength peak (470 nm) of GFP's bimodal absorption spectrum better matches standard fluorescein filter sets; however, it has a considerably lower amplitude than the major absorption peak at 395. In an effort to increase the sensitivity of GFP with routinely available instrumentation, Heim et al. (Nature 373:663-664, 1995) have generated a GFP mutant (serine-65 to threonine; S65T-GFP) which possesses a single absorption peak centered at 490 nm. We have constructed this mutant in order to determine whether it or wild-type GFP (wt-GFP) afforded greater sensitivity when excited near their respective absorption maxima. Using the conventionally available 488 nm and ultraviolet (UV) laser lines from the argon ion laser as well as the 407 nm line from a krypton ion laser with enhanced violet emission, we were able to closely match the absorption maxima of both the S65T and wild-type forms of Aequorea GFP and analyze differences in fluorescence intensity of transiently transfected 293 cells with flow cytometry. The highest fluorescence signal was observed with 488 nm excitation of S65T-GFP relative to all other laser line/GFP pairs. The wt-GFP fluorescence intensity, in contrast, was significantly higher at 407 nm relative to either 488 nm or UV. These results were consistent with parallel spectrofluorometric analysis of the emission spectrum for wt-GFP and S65T-GFP. The relative contribution of cellular autofluorescence at each wavelength was also investigated and shown to be significantly reduced at 407 nm relative to either UV or 488 nm.

Synthesis and turnover of brain phosphoglycerides- results, methods of calculation and interpretation

The important problem of membrane assembly and disassembly can be studied by measurements of rates of tunrover of labeled components. After intracerebral injections of ethanolamine and glycerol into mice, we have found rapid and slow turnover pools of 1,2-diacyl-sn-glycero-3-phosphorylethanolamine (diacyl-GPE) and 1,2-diacyl-sn-glycero-3-phosphorylcholine (diacyl-GPC). We have described the methods for calculation of half-lives for two or more pools and for the calculation of the relative size of the pools. For mice injected between 5 and 8 weeks of age, the rapid turnover pools have a half-life of 1.5 and 1.8 days for diacyl-GPC and diacyl-Ge respectively. Corresponding half-lives for the slow turnover pools are 20 and 27 days. The slow turnover pools include 74% of the diacyl-GPC and 86% of the diacyl-Ge. These turnover rates are in agreement with the flux of fatty acids through the diacylglycerol pools. We have proposed that the rapid turnover pool may be the phosphoglycerides that are exchangable with cytosol carrier proteins and that the slow turnover may represent the catabolism of membrane segments including the intrinsic proteins.