Clinical and echocardiographic features of platypnea-orthodeoxia syndrome: a single-centre experience

Funding Acknowledgements

Type of funding sources: None.

Background

Platypnea-orthodeoxia syndrome (POS) is an uncommon condition characterized by dyspnoea and hypoxemia in the upright position that improves with recumbency.1 Possible causes are intracardiac shunt, pulmonary arteriovenous shunt, and V/Q mismatch.1,2 Echocardiography is the cornerstone of POS diagnosis, with special focus on atrial septal defect (ASD) morphology and right-to-left shunt confirmation.3

Purpose

To evaluate the clinical and echocardiographic features of patients presenting with POS due to a cardiac cause.

Methods

We performed a retrospective analysis of patients diagnosed with POS in our centre between 2015 January and 2021 August. Routine blood tests and transthoracic echocardiogram (TTE) were performed in all patients. Demographics, clinical presentation, blood test results, TTE information, and PFO closure procedure details were recorded.

Results

Seven patients were included, 85.7% female (n = 6). The median (IQR) age was 78 (72-85) years. The most prevalent cardiovascular risk factors were hypertension (100%; n = 7) and overweight/obesity (85.7%; n = 6). Two patients (28.6%) had chronic pulmonary disease. The most common symptoms were fatigue and exercise intolerance (n= 5; 71.4%) and the most frequent sign was persistent hypoxemia (n = 7; 100%), although 28.6% (n = 2) patients did not present the typical positional changes in peripheral oxygen saturation. Haemoglobin levels [14.1 (13.3-15.2)] were within the normal range and serum NTproBNP levels [656 (287-1196)] were slightly elevated. Left ventricle function was preserved in all patients; right ventricle morphology and function were normal in 85.7% (n = 6) patients, low probability of pulmonary hypertension in TTE was found in 85.7% (n = 6), and exuberant Eustachian valve was observed in 14.3% (n = 1). All patients presented atrial septal hypermobility, 87.5% (n = 6) meeting atrial septal aneurysm criteria. Patent foramen ovale was found in 85.7% of patients (n = 6) and ostium secundum ASD in 14.3% (n = 1). POS precipitating factors were aortic root dilation (28.6%; n = 2), chest trauma (14.3%; n = 1), right hip arthroplasty (14.3%; n = 1), atrial septal stretching regarding right volume overload (14.3%; n = 1). The underlying mechanism was unknown in 28.6% (n = 2) of patients. ASD closure was performed in 57.1% (n = 4) of patients: 75% (n = 3) showed residual shunt, but clinical improvement was reported by all. No acute complications were described, except for paroxysmal atrial fibrillation (14.3%; n = 1).

Conclusion

POS diagnosis depends on high clinical suspicion: the most common manifestations are fatigue and persistent hypoxemia. Typical positional changes in oxygen saturation are not present in all patients. Polycythaemia, right chambers dilation, and pulmonary hypertension are not common. Echocardiography is fundamental for diagnosis, allowing right-to-left shunt confirmation and ASD morphology evaluation to outline a successful closure procedure.

Artificial intelligence: an attempt to automate remote device follow-up

Funding Acknowledgements

Type of funding sources: None.

Introduction

Artificial intelligence (AI) through machine learning (ML) refers to the simulation of human intelligence with the capacity for achieving goals within computers. In electrophysiology, ML has many applications in electrocardiography, intracardiac mapping and cardiac implantable electronic devices (CIEDs).

Remote monitoring (RM) of patients equipped with CIEDs associates the analysis of event reports and calendar-based remote follow-ups (FU). ML applications have allowed for risk stratification, improved arrhythmia localisation and streamlined remote monitoring which may significantly reduce the workload faced by electrophysiologists.

Aim

To develop a system that automates cardiac implantable electronic devices remote follow-up.

Methods and Results

We created a Java software application, that uses the latest optical character recognition techniques combined with artificial intelligence and natural language processing to extract information from PDF reports of RM of CIEDs from different manufacturers. The current version is HIPAA (Health Insurance Portability and Accountability Act) complaint and runs on local computers only.

Using the current system, we were able to run and extract data from 30 remote follow-up PDF reports of Cardiac Implantable Defibrillators (ICDs) and Cardiac Resynchronization Therapy with Defibrillator (CRT-Ds).

Time taken from data extraction to conversion of all 30 device PDFs was under 5 minutes.

Process and data extracted are presented in the figure below. (Figure 1)

Conclusion

This machine learning algorithm proved that it is possible to facilitate and automate remote follow-up of cardiac implantable electronic devices.

In a near future this will allow to us to efficiently increase productivity, by speeding and facilitating interpretation of remote device follow-ups, leading to improvements in patientcare and precision cardiovascular medicine.

Furthermore, in the current and future pandemics it may help prevent unnecessary in-person medical visits, avoiding additional, unnecessary strain on an already overburdened and overwhelmed healthcare system, and saving costs. Abstract Figure 1

Cathodoluminescent screen imaging system for seeded blob detection in toroidal plasma experiment

We designed and built a diagnostic based on a cathodoluminescent screen for the detection of turbulent plasma structures with high spatial resolution. The screen is coated with a low threshold energy cathodoluminescent powder that emits light when exposed to a plasma. The emitted light is imaged with a fast frame camera combined with an image intensifier and an optical bandpass filter. The diagnostic is used to study turbulent structures and seeded blobs. The results are analyzed with pattern recognition algorithms to track the turbulent structures and study their evolution in time.

93 A hemodynamic challenge in assessment of echocardiographic mitral regurgitation severity

DIscussion

This case illustrates the importance of assessment of hemodynamic status of the patient during echocardiographic evaluation of mitral regurgitation severity, and presents a pharmacological strategy to compensate hypotensive effects of sedative agents used during TEE.

P235 A happy ending for a dancing thrombus on the right atrium

Discussion

Large right atrial thrombus in the setting of PTE is a clinical situation in which there is no consensus regarding clinical management. In most cases, management is dictated by haemodynamic status of the patient. In the setting of a hemodynamically stable patient, systemic anticoagulation can be an option. Surgery, fibrinolysis and percutaneous aspiration have also been advocated. Successful treatment of right heart thrombus with anticoagulation alone has been reported, but there are also reports of unsuccess with that strategy. This is a case of a successful treatment with anticoagulation alone and so, we currently consider that the choice of treatment strategy based on hemodynamic status continues to be the wisest strategy to adopt.

Abstract P235 Figure. Thrombus before and after

P862 A conservative strategy for a frequently fatal post-myocardial infarction mechanical complication

Discussion

Post-myocardial infarction ventricular septal defect (VSD) is a complication that, regardless of the treatment strategy has a high mortality rate, especially when patient presents in cardiogenic shock. However, when patient is stable and especially when comorbidities imposes a high interventional risk medical treatment can be an option. So far, this is a successful case of a medically managed post-myocardial infarction VSD.

Abstract P862 Figure. Ventricular Septal Defect

P872 A case of transient atrioventricular block: the role of cardiac magnetic resonance imaging

Discussion

Transient atrioventricular block is a well-known complication of myocarditis when there is involvement of the conduction system by the inflammatory reaction. However, in rare cases it can persist or recur. CMRI plays an important role in these cases. Gadolinium-enhanced CMRI can be used to access the extent of inflammation and cellular edema and delayed-enhanced CMRI can also be used to quantify scarring which has important prognostic value. CMRI can also play a crucial role in excluding infiltrative disorders with conduction system involvement. Also, in these patients, the transient aspect of atrioventricular block poses a challenge when deciding about permanent pacemaker insertion.

Abstract P872 Figure. Magnetic Ressonance IVS

P1366 Low-flow, low-gradient severe aortic stenosis: might mitral regurgitation be a culprit?

Introduction

According to current guidelines, given a patient with low-gradient (aortic valve maximum velocity < 4m/s and/or aortic valve mean gradient <40mmHg), aortic valve area (AVA) < 1cm2 and low-flow (stroke volume (SV) < 35mL/min/m2), with preserved left ventricle function (ejection fraction (EF) ≥50%), an integrated approach for assessment of aortic stenosis severity is proposed. We aimed to investigate whether mitral regurgitation can play a role in those cases, possibly being responsible for low antegrade systolic flow.

Methods

We retrospectively analysed 121 consecutive transthoracic echocardiograms (TTEs) of patients with severe aortic stenosis, with AVA < 1.0cm2 as assessed by continuity equation. Patients with low ejection fraction (< 50%) were excluded. We therefore included 84 patients (females 53,6%, mean age 79,1+-10 years). Stroke volume was assessed by Doppler at the left ventricle outflow tract (LVOT). We then compared the prevalence of more than mild mitral regurgitation among patients with low-gradient and low-flow and the other patients.

Results

15 patients had both low-gradient, low-flow and preserved ejection fraction. There was a significant association regarding the presence of more than mild mitral regurgitation among these patients (p = 0.028, OR = 4.7, CI 95% 1.1-20.1). In these patients, it was also observed a higher prevalence of atrial fibrillation (p = 0.03, OR = 6.9, CI 95% 1.74-27.1), lower longitudinal systolic function of right ventricle as measured by TAPSE (16.6 vs 21.5mm, p = 0.028), and a tendency towards higher left atrial volume (113 vs 87mL, p = 0.06).

Conclusions

Given the findings that the prevalence of more than mild mitral regurgitation is higher in patients with severe aortic stenosis as assessed by AVA with both low-gradient, low-flow and preserved ejection fraction, we suggest that the presence of more than mild mitral regurgitation should be considered on the approach of aortic stenosis classification of these patients.

P1298 A conservative strategy for an uncommon complication of endocarditis

Discussion

Infective endocarditis of mechanical prosthesis has different presentations depending on the involvement of prosthesis and periprosthetic structures, and it is associated with high morbidity and mortality. Pseudoaneurysm of the intervalvular fibrosa is an uncommon complication, furthermore when complicating with dissection to near structures such as RVOT and the PT in this case. Treatment is mainly surgical, however, in this case the surgical risk was too high due to comorbidities and a conservative strategy was adopted. It seems that it was a reasonable strategy as the patient evolution was unremarkable when regarding endocarditis. Unfortunately, he ended up dying from probably unrelated complications.

Abstract P1298 Figure. Pseudoaneurysm with fistulization

P3633Should we continue to routinely revascularize patients during valve surgery in optimal medical therapy era?

Background

Optimal management of stable obstructive coronary artery disease (CAD) in patients (pts) undergoing heart valve surgery remains controversial. The aim of the present study is to evaluate the effective prognostic role of CABG in pts undergoing valve surgery who had concomitant CAD.

Methods

We conducted a retrospective multicenter survival analysis using multivariable Cox models and Kaplan-Meier curves of consecutive pts undergoing valve surgery with or without concomitant CABG between January 2015 and February 2017.

Results

From 1196 consecutive pts undergoing valvular surgery in 3 portuguese centers, 257 (21.5%) were found to have obstructive CAD (55.6% male, mean age 74±8 y.o., mean follow-up time 16±8 months, aortic valve disease 78.8%). No coronary revascularization (R) was attempted in 177 pts, complete R was achieved in 40 and R was anatomically incomplete in the remaining 40 pts. Age (75 vs 77.3 y.o.; p=0.202), multivessel disease (46.3% vs 53.8%, p=0.270), aortic valve disease (91.0% vs 92.5%, p=0.683), left ventricular ejection fraction <40% (11.8% vs 19.4%, p=0.272) were comparable between nonrevascularized and revascularized pts; SYNTAX score was low and also similar in both groups (7±12 vs 7±5, p=0.856). Left main disease (8.5% vs 17.5%, p=0.034) and EUROSCORE IIrisk score (2.3±2 vs 3.2±2, p=0.011) was higher for those with any revascularization. Non-revascularized pts had significantly lower all-cause mortality at follow up than those with any R (10.2% vs 21.2%, p=0.016). However, both in-hospital (4% vs 7.5%, p=0.230) and cardiovascular mortality (6.9% vs 7.1%, p=1.00) were similar. In a multivariate analysis, independent predictors for all-cause mortality were: any surgical R (HR 4.52, CI95% 2.09–9.78), baseline atrial fibrillation (HR 2.51, CI95% 1.07–5.90), left main disease (HR 3.153, CI95% 1.26–7.90) and peripheral artery disease (HR 2.95, CI95% 1.036–8.421). All-cause mortality for pts with obstructive CAD was higher than in pts with no CAD (13.6% vs 6.2, p<0.001). Interestingly, however, after multivariable adjustment, complete R was not found to be protective as compared to no R (HR 0.79, IC 0.31–2.06, p=0.633)

Kaplan-Meier Plots

Conclusion

Significant CAD is associated with worse outcomes in pts undergoing valve surgery. In this study, standard angiographically-guided R was not associated with improved results. Randomized controlled trials are needed to further assess risk stratification and the role of coronary R of stable CAD in this setting.

P3628Contemporary coronary artery disease prevalence in a valvular heart disease population undergoing surgery

Background

Patients undergoing heart valve surgery are routinely evaluated for the presence of Coronary Artery Disease (CAD), with the standard practice of combining valve intervention with a revascularization procedure, notably Coronary Artery Bypass Graft (CABG). Older studies suggest rates as high as 50% prevalence of CAD in this population. However, CAD prevalence, its treatment and prognostic implication has been questioned recently.

Objectives

The goal of this study is to evaluate the baseline characteristics, prevalence of CAD and treatment strategies in a contemporary population with valvular heart disease (VHD) referred for valve surgery.

Methods

In a national multicentre registry, consecutive patients, from Jan 2015 to Dec 2016, with a formal indication for heart valve surgery referred for a pre-op routine coronary angiogram were systematically analysed. Baseline characteristics, valve pathology and CAD prevalence and patterns were determined. Obstructive CAD was defined as luminal angiographic stenosis ≥70% (≥50% for left main artery). The prognostic impact of the different valve disease and CAD treatment strategies were assessed.

Results

1175 patients (mean age 72.5±10.1; male 49.2%) fulfilled the clinical or echocardiographic indication for valve surgery by European guidelines. Valvular disease prevalence was: aortic stenosis (66.7%), aortic regurgitation (6.6%), mitral stenosis (6%), mitral regurgitation (19.2%), tricuspid regurgitation (7.5%). Mean follow-up time was 29.06±18.46 months. Prevalence of comorbidities was: Diabetes Mellitus (DM) 26%, chronic obstructive pulmonary disease (COPD) 5.7% and chronic kidney disease (CKD) 23.4%. Mean Euroscore II was 2.6%. Obstructive CAD was present in 27.3% patients. Mean Syntax score was 10.2 (<22 in 88%, 23–32 in 10.2% and >33 in 1.8%). Left main artery and 3-vessel disease were found in 13.1% and 11.8% of patients with CAD, respectively. Valvular surgery was ultimately performed in 80.3%. In patients with CAD, 57.3% were revascularized. All-cause mortality rate during follow-up was 12.9%, with 7.8% from cardiovascular causes. In univariate analysis DM, COPD, CKD, NYHA class, obstructive CAD and no surgery (p<0.05) were associate with mortality on follow up. In multivariate analysis obstructive CAD (OR 2.36, 95% CI 1.53–3.65, p<0.01) and no surgery (OR 6.05, 95% CI 3.95–9.30, p<0.01) persisted as independent all-cause mortality predictors.

Conclusion

In a contemporary cohort of patients with VHD and surgical indication, CAD prevalence is lower (27.3%) than described in literature. Mortality rates were higher in patients with obstructive CAD, worse NYHA functional class and in those who never underwent surgery.

Influence of framework Si/Al ratio and topology on electron transfers in zeolites

From experimental results on H-ZSM-5 and H-*BEA zeolites, it is shown that the stability of radical cations and of charge transfer complexes (CTC) is highly dependent on the distance between Brønsted sites and strong Lewis sites or Brønsted Strong Lewis Pairs (BSLPs).

Influence of hierarchization on electron transfers in structured MFI-type zeolites

H-ZSM-5 zeolite (Si/Al = 19.3) was hydrothermally synthesized. Alkaline and/or acid post-synthesis treatments were carried out to give rise to an interconnected mesoporous volume. The desilication treatment parameters have been tuned (temperature, organic base addition) to obtain a series of samples with increasing mesoporous volume and a constant number of acid sites. The physico-chemical properties of the resulting materials were fully characterized by many techniques (NMR, BET, PXRD, and pyridine thermal desorption followed by infrared spectroscopy). To assess the effect of post-treatments on sample reactivity, the charge separation processes between the zeolite framework and adsorbed trans-stilbene (t-St) molecule were investigated by UV-visible diffuse reflectance. The spectra obtained after t-St adsorption show clear differences depending on the applied post-treatments. It appears that the desilication treatments performed without acidic washing highly stabilize the radical cation resulting from the t-St spontaneous ionization. In contrast, by applying acidic washing after desilication, the ionization process becomes significantly weaker. The results show that the proportion of strong Lewis acid sites in the vicinity of Brønsted sites named Brønsted Strong Lewis Pairs (BSLP), are responsible for the amount of radical cations observed in the different samples. More precisely, it exists an optimal proportion of BSLP to achieve a high ionization rate. On the basis of the experimental results a mechanism for the formation of the t-St radical cation and the charge transfer complex (CTC) is proposed.

Leptin and its receptor: can they help to differentiate chromophobe renal cell carcinoma from renal oncocytoma?

One of the challenges in differentiating chromophobe renal cell carcinoma (chRCC) from benign renal oncocytoma (RO) is overlapping morphology between the two subtypes. The aim of this study was to investigate the usefulness of expression of leptin (Ob) and its receptor (ObR) in discriminating chRCC from RO. Sections from paraffin-embedded, formalin-fixed tumour nephrectomy specimens of 45 patients, made up of 30 chRCC (15 eosinophilic variant and 15 non-eosinophilic variant) and 15 RO, were used in this study. Samples (30) of clear cell RCC (ccRCC), the most common histological subtype, were used to verify staining patterns found by others in our cohort of Australasian patients. Matched morphologically normal non-cancer kidney tissues were included for each specimen. Sections were batch-immunostained using antibodies against Ob and ObR. Stained sections were digitally scanned using Aperio ImageScope, and the expression pattern of Ob and ObR was studied. In this cohort, male to female ratio was 2:1; median age was 64 (45-88 years); and median tumour size was 3.8 cm (range 1.2-18 cm). There were 47 (62.7%) T1, seven T2, 20 T3 and one T4 stage RCC. Two patients with ccRCC presented with metastases. Nuclear expression of Ob was significantly higher in RO compared with chRCC. The increased nuclear expression of Ob in RO compared with chRCC may be a useful aid in the difficult histological differentiation of RO from chRCC, especially eosinophilic variants of chRCC.

Identification of chemicals resulted in selective glycerol conversion as sustainable fuel on Pd-based anode nanocatalysts

Palladium-based nanoparticles were prepared using mild microwave-assisted heating.

The early days of pandemic (H1N1) 2009 virus infection in the central region of Portugal

BACKGROUND

The first case of pandemic (H1N1) 2009 virus infection was diagnosed in the central region of Portugal on June 16, 2009, in a woman infected in Canada.

METHODS

The aim of our study was, first to characterize the clinical and epidemiologic aspects of all the patients with clinical manifestations included in the definition of case for investigation with samples submitted to diagnosis of the pandemic (H1N1) 2009 virus infection, in the central region of Portugal; second to assess the precision of the case definition of case for investigation considered in the study according to the presence or the absence of fever at the moment of clinical observation. We reviewed the medical records of all the patients presenting with Influenza like-illness classified as case for investigation and the first cases of patients infected with the new pandemic (H1N1) 2009 virus, diagnosed in the central region of Portugal during the pandemic period between June and August, 2009, were analyzed. Real-time reverse-transcriptase polymerase-chain-reaction (RT-PCR) testing was used to confirm the pandemic (H1N1) 2009 virus infection. Data collection was performed on a standardized paper format in agreement with the General Health Directorate.

RESULTS AND DISCUSSION

Pandemic (H1N1) 2009 virus infection was confirmed in 255 patients. Overall, median age was 23 years and 42.7 % were included in the category of 20 to 29 years. Confirmed infection in patients with less than 2 years or greater than 50 years was a rare event. The first cases were imported from Europe, namely France, Spain and England. On a second phase, pandemic (H1N1) 2009 virus infection was acquired in the south of Portugal (Algarve), before de diagnosis of the first domestic case. The incidence rate for pandemic (H1N1) 2009 virus infection was 10.7 per 100,000 persons and was different according to the district. It was higher in the district of Coimbra and Guarda were the main roads connecting to Europe are. The median calculated incubation period for the for pandemic (H1N1) 2009 virus infection was 2 days. The length of the clinical manifestations until the patients look for medical observation had a median time of 2 days. All the cases were of mild to moderate severity. No deaths were observed.

CONCLUSIONS

The early days of pandemic (H1N1) 2009 virus infection was mild in our region. Most affected patients were young adults, with the extreme categories ages of life being spared. Early detection and diagnosis, combined with stringent isolation and treatment procedures could have slowed the spread of the infection in our region.

Patterns of healthy lifestyle and positive health attitudes in older Europeans

OBJECTIVES

To determine (i) the extent to which recommended lifestyle healthy behaviors are adopted and the existence of positive attitudes to health; (ii) the relative influence of socio-demographic variables on multiple healthy lifestyle behaviors and positive attitudes to health; (iii) the association between healthy lifestyle behaviors and positive attitudes to health.

DESIGN

Two distinct healthy behavioral measures were developed: (i) healthy lifestyles based on physical activity, no cigarette smoking, no/moderate alcohol drinking, maintaining a "healthy" weight and having no sleeping problems and (ii) positive health attitudes based on having positive emotional attitudes, such as: self-perceived good health status, being calm, peaceful and happy for most of the time, not expecting health to get worse and regular health check-ups. A composite healthy lifestyle index, ranging from 0 (none of behaviors met) to 5 (all behaviors met) was calculated by summing up the individual's scores for the five healthy lifestyle items. Afterwards, each individual's index was collapsed into three levels: 0-2 equivalent to 'level 1' (subjectively regarded as 'too low'), a score of 3 equivalent to 'level 2' ('fair') and 4-5 as 'level 3' satisfactory 'healthy lifestyle' practices. The same procedure was applied to the positive health attitudes index. Multinomial logistic regression analyses by a forward selection procedure were used to calculate the adjusted odds ratio (OR) with 95% confidence interval (95% CI).

PARTICIPANTS

A multi-national sample consisting of 638 older Europeans from 8 countries, aged 65-74 and 75+, living alone or with others.

RESULTS AND CONCLUSIONS

Maintaining a "healthy" weight was the most frequently cited factor in the healthy lifestyles index and therefore assumed to be the most important to the older Europeans in the study; positive attitudes to health were relatively low; participants achieved a 'satisfactory' level for healthy lifestyles index (level 3) more frequently than a satisfactory level for positive attitudes to health; having a satisfactory 'healthy lifestyle' was directly related to having a satisfactory level of positive attitudes to health based on the positive health attitudes index; income and geographical location in Europe appeared to be key predictors for meeting both the recommended healthy lifestyle factors in the index and having positive health attitudes however, the composition and nature of the study sample should be taken into consideration when considering the impact of the location on healthy lifestyles and attitudes to health across Europe.

[Natural history of fetal pyelocaliectasia]

INTRODUCTION

It is estimated that genitourinary anomalies comprise 20% of all antenatally detected fetal anomalies, and pyelocaliectasia is the most common one. Detection of antenatal dilatation of the urinary tract does not always indicate postnatal urinary tract obstruction or even a significant genitourinary anomaly. Most cases will improve spontaneously, representing a temporary physiologic impedence and do not require surgery.

MATERIALS AND METHODS

In a two-year period we studied 197 newborns, with prenatal pyelocaliectasia, without concomitant anomaly, delivered at Maternidade Dr. Daniel de Matos. In the postnatal follow-up period, the infants were followed at Pediatrics Department, at our Center.

RESULTS

A male predilection was found. Ultrasonic follow-up of the 197 infants showed that pyelocaliectasia resolved in 97%, while 3% still presented it in the postnatal ultrasound. Complementary renal evaluation, with voiding cystourethrography and radionuclide imaging, was realised in 29 (15%) infants to further characterize the abnormality detected in postnatal ultrasound. Surgery was performed in four (2%) children.

CONCLUSION

Prenatally diagnosed pyelocaliectasia may be safely observed, and surgical correction should be performed only if renal compromise occurs.

High-resolution heteronuclear correlation spectra between 31P and 27Al in microporous aluminophosphates

A solid-state nuclear magnetic resonance (NMR) experiment, which provides high-resolution two-dimensional heteronuclear correlation (HETCOR) spectra between 27Al and 31P, is described. The first part of the experiment uses triple-quantum or quintuple-quantum magic-angle spinning (MQMAS) NMR of spin-5/2 nuclei (27Al) to produce an isotropic echo that is unaffected by the second-order quadrupolar broadening. The magnetization is then transferred to the spin-1/2 (31P) nuclei via cross-polarization (CP), resulting in isotropic resolution in both spectral dimensions. To illustrate its usefulness, this method (referred to as MQHETCOR) is applied to two important microporous framework aluminophosphates, hydrated VPI-5 and AIPO4-40.

Novel microporous europium and terbium silicates

The synthesis and structural characterization of the first examples of microporous europium(III) and terbium(III) silicates (Na(4)K(2)X(2)Si(16)O(38) x 10H(2)O, X = Eu, Tb) are reported. The structure of these solids was solved by powder X-ray diffraction ab initio (direct) methods and further characterized by chemical analysis (EDS), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), (23)Na and (29)Si magic-angle spinning (MAS) NMR, and luminescence spectroscopy. Both materials display interesting photoluminescence properties and present potential for applications in optoelectronics. This work illustrates the possibility of combining in a given silicate microporosity and optical activity.

Effect of lithium on cyclosporin induced nephrotoxicity in rats

Psychoactive drugs provide essential intervention in the care of transplant recipients, yet little is known of their interaction with immunosuppressants such as cyclosporin (CSA). Lithium (Li) is an invaluable drug for the treatment of manic disorders in organ transplant patients. As both these drugs are known to produce renal toxicity, the concomitant use of CSA and Li may be potentially harmful. The present study was undertaken to investigate the effect of CSA and Li chloride individually and in combination on renal structure and function of rats. Male Sprague-Dawley rats were divided into the following eight groups of seven animals each: group I, control (vehicle only); group 2, Li (2 mEq/ kg i.p.) alone; group 3, CSA 12.5 mg/kg (subcutaneous); group 4, CSA 25 mg/kg; group 5, CSA 50 mg/kg; group 6, CSA 12.5 mg/kg + Li; group 7, CSA 25 mg/kg + Li; and group 8, CSA 50 mg/kg + Li. The drugs were given once a day for seven days; Li being administered 30 min before CSA. Twenty four hours after the last dose of drugs the animals were sacrificed and blood samples were analyzed for blood urea nitrogen (BUN), serum creatinine (SCr), CSA and Li levels. The left kidney was analyzed for malondialdehyde (MDA) and conjugated dienes (CD) levels and right kidney was used for histopathological studies. Our results showed that Li alone did not produce any significant renal toxicity, whereas CSA dose dependently caused structural and functional changes in kidneys. However, significantly higher structural and functional impairment was observed in the animals treated with Li plus CSA as compared to CSA alone treated animals. Several fold increase in blood Li level was also noticed in the rats concomitantly treated with CSA and Li. A significant increase in MDA and CD in the rats treated with CSA plus Li suggests the role of oxidative stress in drug induced nephrotoxicity. These findings clearly demonstrate that even non toxic doses of Li may significantly exacerbate CSA induced nephrotoxicity in rats. The enhanced nephrotoxicity following concomitant use of these drugs may be attributed to significant increase in the bioavailability of Li and enhanced oxidative stress. Further clinical studies are warranted to investigate the interaction of these nephrotoxic drugs in human subjects.

Effect of aluminum on neurological recovery in rats following spinal cord injury

OBJECT

This investigation was undertaken to study the effect of aluminum on neurobehavioral, electrophysiological, structural, and biochemical changes in rats following spinal cord injury (SCI).

METHODS

Adult male Sprague-Dawley rats classified into different groups were given aluminum sulfate-dosed drinking water in the concentrations of 0%, 0.25%, 0.5% and 1%, respectively. After 30 days of aluminum treatment, the animals were subjected to spinal cord trauma. Laminectomy was performed at T7-8 in anesthetized rats, followed by placement of a compression plate (2.2 x 5 mm) loaded with a 35-g weight over the exposed spinal cord for 5 minutes. Control animals underwent the same surgical procedure, but the compression injury was not induced (sham). Postoperative neurological function was assessed using the inclined-plane test and by obtaining a modified Tarlov score and vocal/sensory score daily for 10 days. Electrophysiological changes were assessed using corticomotor evoked potentials, whereas pathological changes were assessed by light microscopy. The level of vitamin E in the spinal cord was measured as an index of antioxidant defense. The behavioral, biochemical, and histological analyses were performed in a blinded fashion.

CONCLUSIONS

Analysis of results obtained in the behavioral studies revealed that the compression of spinal cord produced transient paraparesis in which a maximum motor deficit occurred at Day 1 following SCI and resolved over a period of 10 days. Administration of aluminum significantly impaired the recovery following SCI. Analysis of the results of the biochemical, electrophysiological, and histopathological studies also confirmed the deleterious effects of aluminum on recovery from SCI in rats.

Effect of pentaglobin and piperacillin on survival in a rat model of faecal peritonitis: importance of intervention timings

BACKGROUND

Faecal peritonitis is a progressive pathophysiological condition which may lead to multiple organ failure and death. The reason for the associated morbidity and mortality could be attributed to the fact that some of the subtle alterations in cellular function that occur during the early stage of peritonitis are unidentified and consequently missed, leading to inadequate or delayed intervention. Recent studies have shown that early treatment with antibiotic and antisera containing antibodies to lipopolysaccharide (immunoglobulin) improve the survival rate in these patients. The present investigation was undertaken to study the effect of pentaglobin and piperacillin with particular attention to time lag of drug intervention on animal survival following experimental peritonitis.

METHODS

Experimental peritonitis was produced by inoculating 1 ml/kg of faecal suspension (2:1 w/v in saline) into the peritoneal cavity. Two groups of animals were treated with pentaglobin (4 ml/kg) or piperacillin (1000 mg/kg) respectively, whereas rats in another group received both drugs simultaneously. The first dose of each drug was given at 4 h, 6 h, 8 h and 12 h after faecal inoculation followed by 3 additional doses at 8-h intervals. For biochemical studies, separate groups of animals were used in which the treatment was started 4 h after faecal inoculation and the animals were killed at 12 h after the treatment.

RESULTS

Both piperacillin and pentaglobin prolonged survival time of animals which received the treatment within 6 h of faecal insult. The combination of pentaglobin plus piperacillin produced better results as compared to the individual effect. There was a significant decrease in serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and increase in catalase following faeces-induced septicaemia, suggesting a significant increase in oxidative stress. The changes in enzyme levels were significantly attenuated by both the drugs.

CONCLUSION

The findings suggest that intervention with a combination of pentaglobin and antibiotics within 6 h of peritonitis might significantly improve survival rate in rat.