Fluvastatin-induced myofibrillar damage is associated with elevated ROS, and impaired fatty acid oxidation, and is preceded by mitochondrial morphological changes

Previously, we showed that fluvastatin treatment induces myofibrillar damage and mitochondrial phenotypes in the skeletal muscles of Drosophila. However, the sequential occurrence of mitochondrial phenotypes and myofibril damage remains elusive. To address this, we treated flies with fluvastatin for two and five days and examined their thorax flight muscles using confocal microscopy. In the two-day fluvastatin group, compared to the control, thorax flight muscles exhibited mitochondrial morphological changes, including fragmentation, rounding up and reduced content, while myofibrils remained organized in parallel. In the five-day fluvastatin treatment, not only did mitochondrial morphological changes become more pronounced, but myofibrils became severely disorganized with significantly increased thickness and spacing, along with myofilament abnormalities, suggesting myofibril damage. These findings suggest that fluvastatin-induced mitochondrial changes precede myofibril damage. Moreover, in the five-day fluvastatin group, the mitochondria demonstrated elevated H2O2 and impaired fatty acid oxidation compared to the control group, indicating potential mitochondrial dysfunction. Surprisingly, knocking down Hmgcr (Drosophila homolog of HMGCR) showed normal mitochondrial respiration in all parameters compared to controls or five-day fluvastatin treatment, which suggests that fluvastatin-induced mitochondrial dysfunction might be independent of Hmgcr inhibition. These results provide insights into the sequential occurrence of mitochondria and myofibril damage in statin-induced myopathy for future studies.

Differential Blood-Brain Barrier Transport and Cell Uptake of Cyclic Peptides In Vivo and In Vitro

The blood-brain barrier (BBB) poses major challenges to drug delivery to the CNS. SFTI-1 and kalata B1 are cyclic cell-penetrating peptides (cCPPs) with high potential to be used as scaffolds for drug delivery. We here studied their transport across the BBB and distribution within the brain to gauge the potential of these two cCPPs as scaffolds for CNS drugs. In a rat model, SFTI-1 exhibited, for a peptide, high extent of BBB transport with a partitioning of unbound SFTI-1 across the BBB, K_p,uu,brain, of 13%, while only 0.5% of kalata B1 equilibrated across the BBB. By contrast, kalata B1, but not SFTI-1, readily entered neural cells. SFTI-1, but not kalata B1, could be a potential CNS delivery scaffold for drugs directed to extracellular targets. These findings indicate that differences between the BBB transport and cellular uptake abilities of CPPs are crucial in the development of peptide scaffolds.

Midodrine in treatment of post coronary revascularization vasoplagia; pilot, open label, assessor blinded randomized clinical trial

Purpose

Post cardiac surgery hypotension and inotrope dependence are among major causes of prolonged intensive care unit (ICU) stay. Besides routine managements, catecholamine inotrope-vasopressors are the traditional treatment. However, there is an increasing interest to catecholamine-sparing agents, such as Midodrine, oral alfa1 agonist, in patients with vasoplegia. Up to now there are no randomized study with midodrine on post cardiac surgery patients.

Material and method

In this pilot, open label, assessor blind, randomized clinical trial from June 2020 to December 2021, 65 patients with refractory (more than 24 hours inotropes) hypotension after coronary revascularization were included. Patients were randomly assigned to receive Midodrine add-on therapy (10 mg stat and 5 mg po every 12 hours) or placebo add-on routine treatment. The primary outcome was liberation time from IV inotrope-support. Secondary outcomes were ICU admission time and total vasopressor dosage after randomization.

Results

32 patients enrolled in Midodrine group, with a mean age of 60.72, and 33 patients received placebo with mean age of 63.27. Median liberation time from inotrope was 27 hours in Midodrine group and 49 hours in placebo group (p=0.022). ICU admission time for Midodrine and placebo groups were 115 and 121 hours, respectively (p=0.990). Total vasopressor dosage after randomization were similar in two studied groups, 4352 μg in Midodrine group and 5637 μg in placebo group (p=0.405). No adverse event was observed in Midodrine group.

Conclusion

Midodrine add-on inotrope therapy was a safe medication with appropriate compliance in ICU admitted patients after cardiac surgery, which seems to decrease the inotrope dependent time.

Funding Acknowledgement

Type of funding sources: None.

Realistic approach to evaluate the effect of baseline lipid profile in post cardiac surgery: Restricted Cubic Spline model

Background

There are still many uncertainties in the association between lipid profile and post coronary artery bypass grafting (CABG) outcomes. Although simplifying the association to linear equations makes it understandable but cannot explain many findings.

Methods

Total 17,555 patients who underwent isolated CABG between 2014 and 2016 were evaluated. During the median follow-up of 75.24 months the Restricted Cubic Splines (RCS) estimated from the Cox regression model adjusted for all possible confounders was applied to show a nonlinear relationship of lipid profile contents with the “ln hazard ratio” of mortality and major cerebro-cardiac events.

Results

The relationship between LDL-C and HDL-C with all-cause mortality were non-linear (non-linear P were 0.004 and <0.001, respectively). The relationship between remnant cholesterol and all-cause mortality was linear (linearity P=0.023). Among men, those in the highest LDL-C level (Q4, LDL-C >114) and those in the lowest HDL-C level (Q1, HDL-C <30) showed a significantly higher risk of all-cause mortality compared to other groups (compared with Q3, LDL-C Q4, HR=1.16, 95% CI: 1.02–1.26, P=0.014; HDL-C Q1, HR=1.14, 95% CI: 1.01–1.31, P=0.041). Female patients in the lowest HDL-C level (Q1, HDL-C <30) showed a significantly higher (compared with Q3, HR=1.14, 95% CI: 1.01–1.31, P=0.028) and those in the highest HDL-C level (Q4, HDL-C >43) showed a significantly lower (compared with Q3, HR=0.74, 95% CI: 0.58–0.98, P=0.019) risk of all-cause mortality.

Conclusion

Determining a universal cut off for components of lipid profile may be misleading and should better be revised. Extreme values (very low or very high) for HDL-C and LDL-C have different effects on cardiovascular outcomes.

Funding Acknowledgement

Type of funding sources: None.

BMI modifies the effect of HDL on outcomes after coronary artery bypass grafting surgery

Background

While the important role of both high-density lipoprotein cholesterol (HDL-C) and body mass index (BMI) in the prognosis of coronary artery disease (CAD) is well known, the impact of BMI on the association between HDL-C and cardiovascular outcomes remains unclear.

Purpose

In this regard, we aimed to investigate whether BMI can modify the correlation between HDL-C levels and outcomes in patients who underwent coronary artery bypass grafting (CABG).

Methods

The present registry-based cohort study included patients who underwent isolated, elective, and first time CABG with 18≤BMI<35 kg/m2. The median follow-up period was 76.62 (75.71–77.52) months. The participants categorized into three groups based on BMI: 18.5≤BMI<25 kg/m2, 25≤BMI<30 kg/m2, and 30≤BMI<35 kg/m2. The Cox proportional hazards models and Restricted Cubic Splines (RCS) in the Cox models were applied to evaluate the association between HDL-C and all-cause mortality and occurrence of major adverse cardio-cerebrovascular events (MACCE) in different BMI categories.

Results

From 2006 to 2016, a total of 17309 patients (73% male, mean age 66.17±9.98) were included. Compared to other groups, diabetes, hypertension, dyslipidemia, and family history of coronary disease were more prevalent in patients with 30≤BMI<35 kg/m2 (P<0.05). Cox proportional hazards models did not show a significant correlation between each 1 mg/dl increase in HDL-C and risk of all-cause mortality and MACCE. In contrast, the results of RCS in the Cox models demonstrated a non-linear relationship between HDL-C and outcomes in patients with 30≤BMI<35 kg/m2, with higher levels of HDL-C, were paradoxically associated with a higher risk of all-cause mortality and MACCE in this BMI category. In the 3D presentation of the association between BMI, HDL-C and all-cause mortality, the highest risk of all-cause mortality was seen in low levels of HDL-C (HDL-C <20 mg/dl) and low or very high levels of BMI.

Conclusions

Very high HDL-C levels could be associated with a higher risk of adverse outcomes after CABG, in patients with 30≤BMI<35 kg/m2. These findings suggest a role of obesity in the function and properties of HDL-C thereby, it seems necessary to consider the concomitant conditions such as BMI when evaluating the risk of cardiovascular events.

Funding Acknowledgement

Type of funding sources: None.

Machine learning models for 1-year mortality prediction in hypertensive patients undergoing coronary artery bypass grafting surgery

Background

A significant proportion of patients undergoing coronary artery bypass grafting (CABG) surgery has a variety of comorbidities such as hypertension. Hypertensive patients tend to have poorer prognoses and higher mortality from acute coronary syndrome in short- and mid-term follow-ups. Machine learning (ML) prediction methods are now widely used in different clinical settings, operating more accurately and efficiently than clinicians and traditional scores in many instances.

Purpose

This study was designed to develop and evaluate the ML prediction models of 1-year mortality in hypertensive patients undergoing CABG in our institute during 2005–2015.

Methods

Several baseline and procedural characteristics of CABG hypertensive cases were collected. Train and test data were divided with the proportion of 70:30. Due to a high 1-year survival rate, the synthetic minority oversampling technique (SMOTE) was implemented. In addition, the optimal threshold for determination of sensitivity and specificity was found using 10-fold cross-validation in the train data. After performing feature selection using the random forest method, prediction models were developed using: Support Vector Machine (SVM), Naïve Bayes (NB), Logistic Regression (LR), K-Nearest Neighbors (K-NN), Extreme Gradient Boosting (XGB), and Random Forest (RF) algorithms. Area Under the ROC (Receiver Operating Characteristic) Curve (AUC) in addition to sensitivity, specificity, and accuracy were used to assess the performance of the models.

Results

Among 8943 hypertensive CABG patients with 1-year follow-up, the mean age was 68.27±9.29 years, of whom 303 died during the study period. Eleven features from a total of 26 were chosen to train the models. The most important prediction features being selected were total ventilation time, ejection fraction, triglyceride, and age. LR (AUC=0.819) and XGB (AUC=0.812) outperformed RF (AUC=0.804), NB (AUC=0.791), SVM (AUC=0.715) and KNN (AUC=0.718). The LR model demonstrated the highest specificity (83.00%) and accuracy (82.37%) while the XGB model was the most sensitive one (88.00%).

Conclusion

An applicable prediction system can help clinicians' decision-making for the risk of 1-year mortality in hypertensive CABG patients which may have higher death rate compared with normal population. Although LR, RF, and XGB performance were almost similar and more favourable than the other three, LR remained the most promising predictor, given its AUC.

Funding Acknowledgement

Type of funding sources: None.

Paracetamol (Acetaminophen) and its Effect on the Developing Mouse Brain

Paracetamol, or acetaminophen (AAP), is the most commonly used analgesic during pregnancy and early life. While therapeutic doses of AAP are considered harmless during these periods, recent findings in both humans and rodents suggest a link between developmental exposure to AAP and behavioral consequences later in life. The aim of this study is to evaluate the impact of neonatal exposure to clinically relevant doses of AAP on adult spontaneous behavior, habituation, memory, learning, and cognitive flexibility later in life using a mouse model. Markers of oxidative stress, axon outgrowth, and glutamatergic transmission were also investigated in the hippocampus during the first 24 h after exposure. In addition, potential long-term effects on synaptic density in the hippocampus have been investigated. In a home cage setting, mice neonatally exposed to AAP (30 + 30 mg/kg, 4 h apart) on postnatal day 10 displayed altered spontaneous behavior and changed habituation patterns later in life compared to controls. These mice also displayed reduced memory, learning and cognitive flexibility compared to control animals in the Morris water maze. An increase of markers for oxidative stress was observed in the hippocampus 6 h after AAP exposure. As AAP is the first choice treatment for pain and/or fever during pregnancy and early life, these results may be of great importance for risk assessment. Here we show that AAP can have persistent negative effects on brain development and suggest that AAP, despite the relatively low doses, is capable to induce acute oxidative stress in the hippocampus.

Clinical presentation, disease course, and outcome of COVID-19 in hospitalized patients with and without pre-existing cardiac disease: a cohort study across 18 countries

AIMS

Patients with cardiac disease are considered high risk for poor outcomes following hospitalization with COVID-19. The primary aim of this study was to evaluate heterogeneity in associations between various heart disease subtypes and in-hospital mortality.

METHODS AND RESULTS

We used data from the CAPACITY-COVID registry and LEOSS study. Multivariable Poisson regression models were fitted to assess the association between different types of pre-existing heart disease and in-hospital mortality. A total of 16 511 patients with COVID-19 were included (21.1% aged 66-75 years; 40.2% female) and 31.5% had a history of heart disease. Patients with heart disease were older, predominantly male, and often had other comorbid conditions when compared with those without. Mortality was higher in patients with cardiac disease (29.7%; n = 1545 vs. 15.9%; n = 1797). However, following multivariable adjustment, this difference was not significant [adjusted risk ratio (aRR) 1.08, 95% confidence interval (CI) 1.02-1.15; P = 0.12 (corrected for multiple testing)]. Associations with in-hospital mortality by heart disease subtypes differed considerably, with the strongest association for heart failure (aRR 1.19, 95% CI 1.10-1.30; P < 0.018) particularly for severe (New York Heart Association class III/IV) heart failure (aRR 1.41, 95% CI 1.20-1.64; P < 0.018). None of the other heart disease subtypes, including ischaemic heart disease, remained significant after multivariable adjustment. Serious cardiac complications were diagnosed in <1% of patients.

CONCLUSION

Considerable heterogeneity exists in the strength of association between heart disease subtypes and in-hospital mortality. Of all patients with heart disease, those with heart failure are at greatest risk of death when hospitalized with COVID-19. Serious cardiac complications are rare during hospitalization.

CG4928 Is Vital for Renal Function in Fruit Flies and Membrane Potential in Cells: A First In-Depth Characterization of the Putative Solute Carrier UNC93A

The number of transporter proteins that are not fully characterized is immense. Here, we used Drosophila melanogaster and human cell lines to perform a first in-depth characterization of CG4928, an ortholog to the human UNC93A, of which little is known. Solute carriers regulate and maintain biochemical pathways important for the body, and malfunctioning transport is associated with multiple diseases. Based on phylogenetic analysis, CG4928 is closely related to human UNC93A and has a secondary and a tertiary protein structure and folding similar to major facilitator superfamily transporters. Ubiquitous knockdown of CG4928 causes flies to have a reduced secretion rate from the Malpighian tubules; altering potassium content in the body and in the Malpighian tubules, homologous to the renal system; and results in the development of edema. The edema could be rescued by using amiloride, a common diuretic, and by maintaining the flies on ion-free diets. CG4928-overexpressing cells did not facilitate the transport of sugars and amino acids; however, proximity ligation assay revealed that CG4928 co-localized with TASK¹ channels. Overexpression of CG4928 resulted in induced apoptosis and cytotoxicity, which could be restored when cells were kept in high-sodium media. Furthermore, the basal membrane potential was observed to be disrupted. Taken together, the results indicate that CG4928 is of importance for generating the cellular membrane potential by an unknown manner. However, we speculate that it most likely acts as a regulator or transporter of potassium flows over the membrane.

Probable role for major facilitator superfamily domain containing 6 (MFSD6) in the brain during variable energy consumption

Purpose: The major facilitator superfamily (MFS) is known as the largest and most diverse superfamily containing human transporters, and these transporters are essential as they sustain the homeostasis within cellular compartments by moving substances over lipid membranes.Methods: We have identified a novel MFS protein, named Major facilitator superfamily domain containing 6 (MFSD6), and confirmed that it is phylogenetically related to the human Solute Carrier (SLC) transporter family. A homology model of MFSD6 revealed 12 predicted transmembrane segments (TMS) with the classical MFS fold between TMS 6 and 7.Results: Immunohistological analyses showed specific MFSD6 staining in neurons of wildtype mouse brain tissue, but no expression in astrocytes. Furthermore, we explored expression and probable function(s) of MFSD6 in relation to its phylogenetically related proteins, major facilitator superfamily domain containing 8 (MFSD8) and 10 (MFSD10), which is of interest as both these proteins are involved in diseases.Conclusions: We showed that expression levels of Mfsd6 and Mfsd10 were decreased with elevated or depleted energy consumption, while that of Mfsd8 remained unaffected.

SLC38A10 (SNAT10) is Located in ER and Golgi Compartments and Has a Role in Regulating Nascent Protein Synthesis

The solute carrier (SLC) family-38 of transporters has eleven members known to transport amino acids, with glutamine being a common substrate for ten of them, with SLC38A9 being the exception. In this study, we examine the subcellular localization of SNAT10 in several independent immortalized cell lines and stem cell-derived neurons. Co-localization studies confirmed the SNAT10 was specifically localized to secretory organelles. SNAT10 is expressed in both excitatory and inhibitory neurons in the mouse brain, predominantly in the endoplasmic reticulum, and in the Golgi apparatus. Knock-down experiments of SNAT10, using Slc38a10-specific siRNA in PC12 cells reduced nascent protein synthesis by more than 40%, suggesting that SNAT10 might play a role in signaling pathways that regulate protein synthesis, and may act as a transceptor in a similar fashion to what has been shown previously for SLC38A2 (SNAT2) and SNAT9(SLC38A9).

On the consistency of seismically imaged lower mantle slabs

The geoscience community is increasingly utilizing seismic tomography to interpret mantle heterogeneity and its links to past tectonic and geodynamic processes. To assess the robustness and distribution of positive seismic anomalies, inferred as subducted slabs, we create a set of vote maps for the lower mantle with 14 global P-wave or S-wave tomography models. Based on a depth-dependent threshold metric, an average of 20% of any given tomography model depth is identified as a potential slab. However, upon combining the 14 models, the most consistent positive wavespeed features are identified by an increasing vote count. An overall peak in the most robust anomalies is found between 1000-1400 km depth, followed by a decline to a minimum around 2000 km. While this trend could reflect reduced tomographic resolution in the middle mantle, we show that it may alternatively relate to real changes in the time-dependent subduction flux and/or a mid-lower mantle viscosity increase. An apparent secondary peak in agreement below 2500 km depth may reflect the degree-two lower mantle slow seismic structures. Vote maps illustrate the potential shortcomings of using a limited number or type of tomography models and slab threshold criteria.

[Risks acceptability related to obstetrical epidural analgesia]

OBJECTIVES

Evaluation of the acceptability of complications related to obstetrical epidural analgesia in two populations, parturients and anesthesiologists.

STUDY DESIGN

Prospective, transversal, single center study.

MATERIALS AND METHODS

Evaluation of the acceptability of complications associated with obstetric epidural analgesia performed using a questionnaire of six clinical scenarii in two populations: parturients cared at the University maternity of Nancy and anesthesiologists of Lorraine. Patients were interviewed by an anesthesiologist, physicians via Internet. Acceptability was assessed using two tools, the absolute acceptability with a visual analog scale and the relative acceptability obtained by classifying clinical scenario against each other, in ascending order of acceptability.

RESULTS

One hundred and forty-six parturients and 87 anesthetists assessed the acceptability of the different scenarios. The three less serious scenarios (hypotension, failure, dural tap) were acceptable for both populations. One case (spinal hematoma) was unacceptable for parturients. Three cases of varying severity (failure, dural tap, plexus injury with sequelae) were judged significantly less acceptable by patients than physicians (5.9 vs. 7.9 [P<0.001], 5.75 vs. 8.1 [P<0.01], 4.1 vs. 5.1 [P=0.035]). Multivariate analysis did not show any predictive factor of acceptability in both populations.

CONCLUSION

In this study, the overall acceptability of the inherent complications of epidural analgesia was good in the two populations. It was essentially based on the notion of severity and preventability. A large interindividual variability was observed and a better acceptance by the anesthesiologists.

Prevalence of left main coronary artery disease among patients with ischemic heart disease: insights from the Tehran Angiography Registry

AIM

This study was designed to investigate the prevalence of left main coronary artery (LMCA) significant stenosis among patients with stable angina (SA) or acute coronary syndromes (ACSs) and to assess the influence of demographic and clinical profiles on these findings.

METHODS

A review of the Angiography Registry demonstrated that 18137 patients had SA or ACSs. The patients' characteristics were compared in subgroups with and without LMCA disease.

RESULTS

Significant and minimal LMCA stenoses were found in 659 (3.6%) and 1157 (6.4%) patients, respectively. An unprotected LMCA disease was estimated in 609 (3.4%) subjects. A cumulative Logit Model analysis revealed the male gender (odds ratio [OR]=1.480, 95% confidence interval [CI]=1.287 to 1.703; P<0.001), diabetes mellitus (OR=1.158, 95% CI=1.029 to 1.303; P=0.015), dyslipidemia (OR=1.125, 95% CI=1.001 to 1.265; P=0.048), and aging (OR=1.028, 95% CI=1.022 to 1.034; P<0.001) as the independent predictors of LMCA stenosis with coexistent diseases in the rest of the coronary arteries. In the patients with normal or minimal stenoses of the other coronary arteries, cigarette smoking (OR=3.749, 95% CI=1.698 to 8.070) was found to be the independent risk factor of isolated LMCA disease. Luminal stenosis >50% in the right coronary artery, the left circumflex artery, and the left anterior descending artery was significantly more frequent in association with LMCA disease.

CONCLUSIONS

The patients with LMCA disease were more likely to be male, older, and have diabetes mellitus or dyslipidemia, whereas cigarette smoking was found as an independent predictor of isolated LMCA. There was a strong correlation between the severity of LMCA stenosis and coexistent diseases in the rest of the coronary arteries.

Expression of reverse cholesterol transport proteins ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI) in the retina and retinal pigment epithelium

AIMS

Excessive lipid accumulation in Bruch's membrane (BrM) is a hallmark of ageing, the major risk factor for age-related macular degeneration (AMD). Retinal pigment epithelial (RPE) cells may utilise reverse cholesterol transport (RCT) activity to move lipid into BrM, mediated through ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI).

METHODS

ABCA1 expression was assessed by reverse transcription polymerase chain reaction (RT-PCR) and western blotting of human RPE cell extracts. Lipid transport assays were performed using radiolabelled photoreceptor outer segments (POS). ABCA1 and SR-BI expression was examined in normal mouse eyes by immunofluorescence staining. BrMs of ABCA1 and SR-BI heterozygous mice were examined microscopically.

RESULTS

Human RPE cells expressed ABCA1 mRNA and protein. The ABCA1 and SR-BI inhibitor glyburide (also known as glibenclamide) abolished basal transport of POS-derived lipids in RPE cells in the presence of high-density lipoprotein. Mouse retina and RPE expressed ABCA1 and SR-BI. SR-BI was highly expressed in RPE. BrMs were significantly thickened in SR-BI heterozygous mice, but not in ABCA1 heterozygous mice.

CONCLUSION

RPE cells express ABCA1 and SR-BI. This implies a significant role for SR-BI and ABCA1 in lipid transport and RCT in the retina and RPE.

Non-invasive monitoring of commonly used intraocular drugs against endophthalmitis by Raman spectroscopy

PURPOSE

To develop a non-contact and non-invasive method for quantification of the local concentration of certain antibiotic and antifungal drugs in the eye.

STUDY DESIGN/MATERIALS AND METHODS

An integrated CCD-based Raman spectroscopic system designed specifically for ophthalmic applications was used to non-invasively detect the presence of ceftazidime and amphotericin B in ocular media. Specific Raman signatures of the above named drugs were determined for various concentrations that were injected through a needle in the aqueous humor of rabbit eyes in vivo. Raman spectra were subsequently acquired by focusing an argon laser beam within the anterior chamber of the eye.

RESULTS

Compared to ocular tissue, unique spectral features of ceftazidime appeared near 1,028, 1,506, 1,586, and 1,641 cm(-1). Amphotericin B exhibited its characteristic peaks at 1,156.5 and 1,556 cm(-1). The amplitude of the spectral peak corresponding to these drugs (acquired by 1 second exposure time and 25 mW of laser power) were determined to be linearly dependent on their local concentration in the anterior chamber of the eye.

CONCLUSIONS

Raman spectroscopy may offer an effective tool to non-invasively assess the local concentration of the delivered drugs within the ocular media. This technique potentially could be used to investigate the pharmacokinetics of intraocular drugs in vivo either from a releasing implant or a direct injection.

The respiratory and allergic manifestations of human myiasis caused by larvae of the sheep bot fly (Oestrus ovis): a report of 33 pharyngeal cases from southern Iran

Myiasis--the feeding of fly larvae on living mammals--may have various presentations, depending on the tissues or organs involved. The respiratory and non-respiratory manifestations of human pharyngeal myiasis caused by Oestrus ovis larvae in 33 patients from the Fars province, in southern Iran, are described here. All but one of the 33 cases were male and all lived in rural areas, in close contact with sheep and goats. The myiasis only occurred in spring and summer (April-September). Symptoms always appeared abruptly, all of the cases sensing the presence of foreign bodies in their throats, a burning sensation and itching in the throat being followed by cough and then various other respiratory, nasal, aural, and eye manifestations. Fly larvae were observed directly in the throats of five patients, and recovered in throat washings from all 33 cases. All of the larvae were identified as those of the sheep bot fly (Oestrus ovis). Removal of the larvae, by irrigation of the throat with a large volume of normal saline, provided an effective and fast treatment. In Iran at least, myiasis caused by Oestrus ovis larvae should be considered an occupational disease among farmers who keep sheep and goats.

Noninvasive detection of ganciclovir in ocular tissue by Raman spectroscopy: implication for monitoring of drug release

Treatment of various pathological conditions in ophthalmology, such as cytomegalovirus (CMV) retinopathy and endophthalmitis, requires a local drug intervention rather than a systemic approach. Accurate knowledge of intraocular drug concentration can permit the ophthalmologist to maintain drug levels within the therapeutic levels necessary for an optimal prognosis, while preventing or minimizing toxicity associated with drug overdose.

PURPOSE

To develop a noninvasive/noncontact method for quantification of the local concentration of ganciclovir in the ocular media.

METHODS

An integrated CCD-based Raman spectroscopic system designed specifically for ophthalmic applications was used to noninvasively detect the presence of ganciclovir in the ocular media. Various known concentrations of ganciclovir were injected into the aqueous humor of rabbit eyes in a pilot study, in vivo. Raman spectra were then acquired by focusing an argon laser beam within the anterior chamber of the eye. The specific Raman signature of ganciclovir was assessed at several concentrations.

RESULTS

Spectral features unique to ganciclovir were identified and distinguished from those of ocular tissue. The amplitudes of the spectral peaks corresponding to ganciclovir exhibited a linear dependence on the local concentration of the drug in the anterior chamber of the eye.

CONCLUSION

Raman spectroscopy may offer an effective tool for the noninvasive assessment of the local concentration of ganciclovir in the ocular media. This technique offers the potential to determine both the amount and the rate of the drug release from implants designed to deliver antiviral drugs locally within the eye. The availability of such data could enable the ophthalmologist to improve treatment efficacy by avoiding premature or late surgical replacement of the implants.

Lack of effect of high doses of inhaled morphine on exercise endurance in chronic obstructive pulmonary disease

Systemic opiates may relieve dyspnoea and improve exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). Small doses of inhaled opiates may have similar effects; however, recent studies have shown no benefit. We studied higher doses of inhaled morphine and measured systemic absorption to determine whether any beneficial actions are local or systemic. Twenty and 40 mg doses and 0.9% saline were nebulized in a randomized, double-blind study of 16 patients with stable COPD. Patients performed 6 min walk tests immediately after the nebulized test solution (Walk 1) and again 60 min later (Walk 2). Arterial oxygen saturation (Sa,O2), modified Borg dyspnoea score and cardiac frequency were recorded during each walk. There was no difference between placebo and either dose of nebulized morphine on these measurements. The higher dose of nebulized morphine achieved a higher plasma concentration. The highest plasma concentration was measured immediately after nebulization, and this decreased steadily in the hour thereafter (p<0.002). There was no correlation between the change in walk distance and the change in plasma morphine concentration after either dose of nebulized morphine. We conclude that higher doses of nebulized morphine do not improve exercise endurance or relieve dyspnoea in patients with chronic obstructive pulmonary disease, and that morphine is rapidly absorbed systemically after inhalation.