Hypotensive patient with superior vena cava obstruction diagnosed using resuscitative transesophageal echocardiography

BACKGROUND

Superior vena cava syndrome (SVCS) is a malignancy-related emergency. It is caused by obstruction of blood flow in the superior vena cava (SVC) secondary to intraluminal thrombosis, external compression, or direct invasion of tumor.

CASE SUMMARY

A 49-year-old male presented to the emergency department (ED) with acute hypoxemic respiratory failure. He was intubated and treated as pneumonia. Post-intubation, he became hypotensive, requiring fluid resuscitation and inotropic support. Resuscitative transesophageal echocardiography (TEE) showed external compression by a lung mass and an intraluminal thrombus causing SVC obstruction. Computed tomography (CT) angiography was performed, and it confirmed the TEE findings. A provisional diagnosis of lung carcinoma was made, and he underwent endovascular therapy for rapid symptomatic relief.

DISCUSSION

This case report highlights the role of resuscitative TEE in evaluating a hypotensive patient with clinical suspicion of SVCS at the emergency department. TEE performed at the bedside could help to diagnose and demonstrate the pathology causing SVCS in this case. TEE allowed high-quality image acquisition and was able to overcome the limitation of transthoracic echocardiography (TTE). TEE should be considered as an alternative ED imaging modality in the management of SVCS.

LEARNING POINTS

Transesophageal echocardiography (TEE)-guided transvenous pacing (TVP) in emergency department

BACKGROUND

Placement of a temporary pacemaker is a vital skill in the emergency setting in patients that present with life-threatening bradycardia. Transvenous pacing is the definitive method of stabilizing the arrhythmia compared to transcutaneous pacing, as it provides more comfort and better control of heart rate, until the insertion of a permanent pacemaker.

CASE REPORT

In this case report, we describe the steps using TEE to guide the insertion of transvenous pacer at the emergency department. Traditionally, the process of floating a transvenous pacer wire is performed "blindly" using landmarks and a monitoring ECG finding for capture, or under transthoracic echocardiography (TTE) ultrasound guidance. The blind procedure is associated with higher rate of failure and complications. While guidance using TTE is associated with higher success rates and fewer complications, inadequate imaging of the right side of the heart may limit the utility of this imaging modality. The use of transesophageal echocardiography (TEE) by emergency medicine and critical care physicians has gained traction in recent years due to its clear images and lack of interference with procedures being performed on the chest. In this article, we describe a protocol using TEE to guide the insertion of transvenous pacer through a case illustration.

Airway ultrasound to detect subglottic secretion above endotracheal tube cuff

BACKGROUND

Subglottic secretion had been proven as one of the causes of microaspiration and increased risk of ventilator-associated pneumonia (VAP). The role of ultrasound to detect subglottic secretion has not yet been established.

PURPOSE

The purpose of this study is to determine the sensitivity and specificity of upper airway ultrasound (US) in the detection of subglottic secretions as compared to computed tomography (CT) scanning.

MATERIAL AND METHODS

A prospective observational study was carried out in adult trauma patients requiring mechanical ventilation and cervical CT scan. All patients had an endotracheal tube cuff-pressure maintained between 20 and 30 cm H₂O. Airway US was performed at the bedside immediately before the patient was transferred to the CT scan suite. The sensitivity, specificity, and positive/negative predictive values (PPV, NPV) of the upper airway US detection of subglottic secretions were then calculated and compared with CT findings.

RESULTS

Fifty participants were consecutively included. Subglottic secretions were detected in 31 patients using upper airway US. The sensitivity and specificity of upper airway US in detecting subglottic secretion were 96.7% and 90%, respectively (PPV 93.5%, NPV 94.7%). 18 (58%) patients with subglottic secretions developed VAP during their ICU stay (p = 0.01). The area under the receiver operating curve (AUROC) was 0.977 (95% CI 0.936-1.00).

CONCLUSIONS

Upper airway US is a useful tool for detecting subglottic secretions with high sensitivity and specificity.

CLINICAL IMPLICATIONS

This study shows: 1. Upper airway US may aid in detecting subglottic secretions, which are linked to VAP. 2. Detecting subglottic secretions at the bedside aids in determining the best frequency of subglottic aspiration to clean the subglottic trachea. 3. Upper airway US may also aid in detecting the correct ETT position. Trial registration Clinicaltrials.gov.

CLINICALTRIALS

gov identifier NCT04739878 Date of registration 2nd May 2021 URL of trial registry record https://clinicaltrials.gov/ct2/show/NCT04739878 .

Inhaled volatile anesthetic gas for severe bronchospasm in the emergency department

Bronchospasm is caused by reversible constriction of the smooth muscles of the bronchial tree. This causes obstruction of the lower airways, which is commonly seen at the emergency department (ED) in patients with acute exacerbation of asthma or chronic obstructive pulmonary disease. Ventilation may be difficult in mechanically intubated patients with severe bronchospasm due to airflow limitation, air trapping, and high airway resistance. The beneficial effects of volatile inhaled anesthetic gas had been reported due to its bronchodilation properties. In this case series, we would like to share our experience delivering inhaled volatile anesthetic gas via a conserving device for three patients with refractory bronchospasm at the ED. Inhaled anesthetic gas is safe, feasible and should be considered as an alternative rescue therapy for ventilated patients with severe lower airway obstruction.

Worsening cardiac tamponade after pericardiocentesis in a patient with anterior mediastinum mass: a case report

Background

Mediastinal mass is an entity with variable pathology and clinical spectrum. Anterior mediastinal mass can result in severe symptoms due to involvement of surrounding vital structures such as the great vessels, trachea-bronchial tree, and heart. We highlight a case of cardiac tamponade in a patient with an anterior mediastinal mass that was paradoxically worsened after decompressive pericardiocentesis.

Case summary

A 21-year-old male presented to the emergency department (ED) with breathlessness and hypotension. Bedside focused cardiac ultrasound revealed cardiac tamponade which was made worse with an anterior mediastinal mass compressing the right heart chambers. The patient was intubated for respiratory failure, following which an ultrasound-guided pericardiocentesis was performed. Unexpectedly, his hemodynamic status worsened after aspiration of 1000 mL of pericardial fluid. A repeat focused cardiac ultrasound showed reduced pericardial effusion, but worsening of right heart chambers compression by the mediastinal mass. Re-expansion of the pericardium space with 600 mL of normal saline improved the patient’s vital signs, and reduced the right heart compression. Computed tomography was deferred due to the patient’s hemodynamic instability. Despite resuscitation with fluids and initiation of vasopressor, the patient’s condition deteriorated. He succumbed to his illness due to obstructive shock causing multi-organ failure. The autopsy showed a large anterior mediastinal mass, and histopathological examination confirmed the diagnosis of lymphoma.

Discussion

This case demonstrated the therapeutic challenges of managing a shock patient with anterior mediastinal mass, and massive pericardial effusion causing cardiac tamponade.

A novel in-plane technique ultrasound-guided pericardiocentesis via subcostal approach

Background

Cardiac tamponade occurs when fluid or blood, fills the pericardial space, and causes hemodynamic compromise due to compression of the heart. It is a potentially life-threatening condition, that requires rapid recognition and immediate treatment. Formerly, blind or surgical techniques were used, and it is associated with complications. Medical technology development has enabled us to perform the procedure safely, with the assistance of ultrasound devices. This article will highlight the novel use of an in-plane subcostal technique, as a safe option for pericardiocentesis in cardiac tamponade.

Case presentation

A 50-year-old man presented to the emergency department (ED) with shortness of breath and shock. He was intubated for respiratory distress. His bedside echocardiography showed cardiac tamponade. Ultrasound-guided pericardiocentesis was carried out using an in-plane technique, at the subcostal region, with a high-frequency linear ultrasound transducer. This particular method provided full visualization of needle trajectory throughout the procedure. It was successfully completed with no complications and patient’s hemodynamic status improved post-procedure. He was successfully discharged on day 13.

Conclusions

The in-plane subcostal pericardiocentesis is a safe, and simple approach that can be performed in the ED for patients with cardiac tamponade. We recommend this new in-plane method, with high-frequency linear transducer at the subcostal area as an alternative when cardiac window for other approaches cannot be visualized.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13089-022-00271-9.

Distribution and diversity of aquatic insects in different water bodies of Qatar

Aquatic insect fauna remains an important tool for bio indication of environmental disturbance, while maintaining a healthy aquatic system. The purpose of the study was to document and to identify the diversity and distribution patterns of aquatic insect, a highly ignored aspect from the Qatar. Following the standard procedures, the samples were collected from aquatic habitats during the period October 2015 to May 2017 on monthly basis. A total of 11,287 individuals, belonging to 6 orders were captured. Dipterans were the abundant with the percentages of 71.01 (n=8,015), while the lowest percentage was observed for Coleoptera 0.04 (n=05). Twelve insects families were identified, among these five were reported under Diptera, followed by Hemiptera (03), while Coleoptera, Tricoptera, Odonata, and Ephemeroptera were represented by single families. Among the selected localities, Dipterans were collected from 10 stations, followed by Hemiptera (9), Coleoptera (4), Odonota (4), Ephemeroptera (3) and Trichoptera (1) respectively. Among the water bodies samples, streams were the most preferred habitats (n=2,767), while drinking water pools were the least (27). Moreover, the highest Simpson diversity index of 1.48 and lowest of 0.47 was recorded for flooded sewage pool and plastic containers respectively, while the low evenness values were observed for ponds, and less than 1 Margalef's diversity values were seen for all habitats. This study documents the patterns of the diversity and distribution of aquatic insects, and provides a baseline for the future studies from Qatar.

Emergency physician-performed emergency bronchoscopy in cardiac arrest patient due to acute foreign body airway obstruction

As foreign body airway obstruction (FBAO) can be life-threatening, it has to be promptly diagnosed and treated. We report a case series of three patients presenting to the emergency department with cardiac arrest due to FBAO. In each case, ventilation was difficult due to high airway resistance. As FBAO was suspected, the emergency physician did a prompt flexible bronchoscopy to confirm the diagnosis and retrieve the foreign body. Flexible bronchoscopy is an important diagnostic and therapeutic tool for emergency airway management, and is a relatively safe procedure if performed by a trained personnel. The life-saving benefits of bronchoscopy outweigh the small risks of complications such as bleeding, desaturation and pneumothorax. In the three cases, the removal of the obstructing material led to immediate improvements in oxygenation and ventilation. The patients had return of spontaneous circulation after cardiopulmonary resuscitation and definite airway control.

Helmet continuous positive airway pressure vs. high flow nasal cannula oxygen in acute cardiogenic pulmonary oedema: a randomized controlled trial

AIMS 

Non-invasive ventilation represents an established treatment for acute cardiogenic pulmonary oedema (ACPO) although no data regarding the best ventilatory strategy are available. We aimed to compare the effectiveness of helmet CPAP (hCPAP) and high flow nasal cannula (HFNC) in the early treatment of ACPO.

METHODS AND RESULTS 

Single-centre randomized controlled trial of patients admitted to the emergency department due to ACPO with hypoxemia and dyspnoea on face mask oxygen therapy. Patients were randomly assigned with a 1:1 ratio to receive hCPAP or HFNC and FiO2 set to achieve an arterial oxygen saturation >94%. The primary outcome was a reduction in respiratory rate; secondary outcomes included changes in heart rate, PaO2/FiO2 ratio, Heart rate, Acidosis, Consciousness, Oxygenation, and Respiratory rate (HACOR) score, Dyspnoea Scale, and intubation rate. Data were collected before hCPAP/HFNC placement and after 1 h of treatment. Amongst 188 patients randomized, hCPAP was more effective than HFNC in reducing respiratory rate [-12 (95% CI; 11-13) vs. -9 (95% CI; 8-10), P < 0.001] and was associated with greater heart rate reduction [-20 (95% CI; 17-23) vs. -15 (95% CI; 12-18), P = 0.042], P/F ratio improvement [+149 (95% CI; 135-163) vs. +120 (95% CI; 107-132), P = 0.003] as well as in HACOR scores [6 (0-12) vs. 4 (2-9), P < 0.001] and Dyspnoea Scale [4 (1-7) vs. 3.5 (1-6), P = 0.003]. No differences in intubation rate were noted (P = 0.321).

CONCLUSION 

Amongst patients with ACPO, hCPAP resulted in a greater short-term improvement in respiratory and hemodynamic parameters as compared with HFNC.

TRIAL REGISTRATION 

Clinical trial submission: NMRR-17-1839-36966 (IIR). Registry name: Medical Research and Ethics Committee of Malaysia Ministry of Health. Clinicaltrials.gov identifier: NCT04005092. URL registry: https://clinicaltrials.gov/ct2/show/NCT04005092.

Resuscitative transesophageal echocardiography in the diagnosis of post-CABG loculated pericardial clot causing cardiac tamponade

Background

Pericardial effusion is a known complication of post-open cardiac surgery which can progress to life-threatening cardiac tamponade. Classical signs of tamponade such as hypotension and pulsus paradoxus are often absent. Diagnosing acute cardiac tamponade with transthoracic echocardiography (TTE) can be challenging in post-cardiac surgical patients due to distorted anatomy and limited scanning windows by the presence of surgical dressings or scar. Additionally, this patient population is more likely to have a loculated pericardial effusion, or an effusion that is isoechoic in appearance secondary to clotted blood. These findings can be challenging to visualize with traditional TTE. Missed diagnosis of cardiac tamponade due to loculated pericardial clot can result in delayed diagnosis and clinical management.

Case presentation

We report a case series that illustrates the diagnostic challenge and value of resuscitative transesophageal echocardiography (TEE) in the emergency department (ED) for the diagnosis of cardiac tamponade due to posterior loculated pericardial clot in post-surgical coronary artery bypass graft (CABG) patients.

Conclusions

Cardiac tamponade due to loculated posterior pericardial clot post-CABG requires prompt diagnosis and appropriate management to avoid the potential for hemodynamic instability. Transesophageal echocardiography allows a rapid diagnosis, early appropriate referral and an opportunity to institute appropriate therapeutic measures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13089-021-00225-7.

Shock due to superior vena cava obstruction detected with point of care ultrasound

Superior Vena Cava (SVC) syndrome is caused by SVC obstruction by external compression or intraluminal thrombus. Patients with the condition can present with upper body swelling, shortness of breath and shock. This case report highlights the use of point-of-care ultrasound (POCUS) to evaluate a patient with SVC syndrome in the emergency department. The test offers many advantages over computed tomography (CT), venography, and magnetic resonance imaging which are limited in hemodynamically unstable patients. A 60-year-old male presented with acute respiratory distress and shock. The POCUS showed the presence of a right lung consolidation and SVC thrombus. CT revealed the presence of a large mediastinal mass causing compression of the SVC with clot seen inside the vessel. The patient was thrombolysed with intravenous streptokinase and his hemodynamics improved. Further investigation confirmed the diagnosis of lymphoma. The SVC can be visualized with transthoracic echocardiography using either the suprasternal, right supraclavicular or right parasternal approach. In this case, the presence of consolidation of the right lung mass provided an acoustic window for the visualization of the SVC using the right parasternal view, thereby allowing for more rapid diagnosis and management.

Pericardial decompression syndrome: A complication of pericardiocentesis

Pericardial Decompression Syndrome (PDS) is an uncommon but life-threatening complication following pericardiocentesis for cardiac tamponade. We report PDS after pericardiocentesis in two patients that presented to the emergency department with cardiac tamponade. In both cases, pericardiocentesis was performed under ultrasound guidance using the left parasternal approach and approximately 1200-1500 mL of pericardial fluid was removed. Immediately after pericardiocentesis, the haemodynamic status of the patients improved. However, 2-3 h post decompression, both patients developed hypotension and pulmonary edema with reduced left ventricular function, suggestive of PDS. PDS is a condition that is described as paradoxical worsening of vital signs after successful decompression of the pericardium in the setting of acute tamponade. Three possible mechanisms explaining PDS are ischaemic, hemodynamic and autonomic processes. If PDS is unrecognized and untreated, it is associated with a high mortality rate secondary to pulmonary edema and cardiogenic shock. If managed urgently, the cardiopulmonary dysfunction in PDS is usually transient and largely reversible with supportive care.

Usage of airway ultrasound as an assessment and prediction tool of a difficult airway management

Airway assessment is important in emergency airway management. A difficult airway can lead to life-threatening complications. A perfect airway assessment tool does not exist and unanticipated difficulty will remain unforeseen. Current bedside clinical predictors of the difficult airway are unreliable but airway ultrasound can be used as an adjunct to predict difficult laryngoscopy. We report a case of a 60-year-old man presenting to the emergency department with shortness of breath, hoarseness of voice and stridor. Airway ultrasound revealed a large laryngeal mass narrowing the upper airway, extending to bilateral vocal cords with heterogenous echogenicity. In view of impending complete upper airway obstruction, acute respiratory distress and airway ultrasound findings, urgent emergency tracheostomy was chosen as definitive airway over endotracheal intubation or surgical cricothyroidotomy. Point of care ultrasound (POCUS) was used to evaluate this patient with severe upper airway obstruction. A laryngeal mass was detected by ultrasound and this pointed towards the presence of a difficult airway. POCUS was a good non-invasive tool used for airway assessment in this uncooperative and unstable patient. Ultrasound predictors of the difficult airway include the inability to visualize the hyoid bone, short hyomental distance ratio, high pretracheal anterior neck thickness and large tongue size. Besides airway assessment, ultrasound can also help to predict endotracheal tube size, confirm intubation and guide emergency airway procedures such as cricothyroidotomy and tracheostomy. Point of care ultrasound of the upper airway can be used in airway assessment to identify distorted airway anatomy, pathological lesions and guide treatment decisions.

Novel role of focused airway ultrasound in early airway assessment of suspected laryngeal trauma

Background

Upper airway injury secondary to blunt neck trauma can lead to upper airway obstruction and potentially cause a life-threatening condition. The most important aspect in the care of laryngeal trauma is to establish a secure airway. Focused airway ultrasound enables recognition of important upper airway structures, offers early opportunity to identify life-threatening upper airway injury, and allows assessment of the extent of injury. This information that can be obtained rapidly at the bedside has the potential to facilitate rapid intervention.

Case presentation

We report a case series that illustrate the diagnostic value of focused airway ultrasound in the diagnosis of laryngeal trauma in patients presenting with blunt neck injury.

Conclusion

Early recognition, appropriate triaging, accurate airway evaluation, and prompt management of such injuries are essential. In this case series, we introduce the potential role of focused airway ultrasound in suspected laryngeal trauma, and the correlation of these exam findings with that of computed tomography (CT) scanning, based on the Schaefer classification of laryngeal injury.

Brain network disintegration as a final common pathway for delirium: a systematic review and qualitative meta-analysis

Delirium is an acute neuropsychiatric syndrome characterized by altered levels of attention and awareness with cognitive deficits. It is most prevalent in elderly hospitalized patients and related to poor outcomes. Predisposing risk factors, such as older age, determine the baseline vulnerability for delirium, while precipitating factors, such as use of sedatives, trigger the syndrome. Risk factors are heterogeneous and the underlying biological mechanisms leading to vulnerability for delirium are poorly understood. We tested the hypothesis that delirium and its risk factors are associated with consistent brain network changes. We performed a systematic review and qualitative meta-analysis and included 126 brain network publications on delirium and its risk factors. Findings were evaluated after an assessment of methodological quality, providing N=99 studies of good or excellent quality on predisposing risk factors, N=10 on precipitation risk factors and N=7 on delirium. Delirium was consistently associated with functional network disruptions, including lower EEG connectivity strength and decreased fMRI network integration. Risk factors for delirium were associated with lower structural connectivity strength and less efficient structural network organization. Decreased connectivity strength and efficiency appear to characterize structural brain networks of patients at risk for delirium, possibly impairing the functional network, while functional network disintegration seems to be a final common pathway for the syndrome.

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Delirium is consistently associated with functional network impairments.

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Risk factors are associated with lower structural connectivity strength.

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Risk factors are associated with a less efficient structural network organization.

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Structural impairments make the functional network more vulnerable to deterioration.

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Functional network disintegration seems to be a final common pathway for delirium.

Aedes albopictus in urban and forested areas of Malaysia: A study of mitochondrial sequence variation using the CO1 marker

This study explores the use of a long fragment of the mitochondrial cytochrome oxidase subunit 1 (CO1) marker to elucidate the genetic diversity of Aedes albopictus sampled from urban and forested regions in Peninsular and East Malaysia. A total of 36 samples were collected from 5 localities from which its genetic variability was analysed. 33 distinct mtDNA haplotypes were identified following the amplification and sequencing of the concatenated CO1 gene. The analysed region of the CO1 gene identified substantial levels of genetic diversity among mosquitoes in urban populations and revealed unique genealogical relationships between local isolates as revealed in the haplotype network. This study highlights the reliability of the long CO1 fragment to identify genetic divergence of Aedes albopictus which can be utilized in forthcoming studies.

Updated abundance and distribution of Aedes albopictus (Skuse) (Diptera: Culicidae) in Penang Island, Malaysia

Reduction of dengue cases and forecast its risk, and identification of vectors breeding habitats and their abundance is the prime target in any dengue control programme. In this aspect, larval surveys were conducted in four localities in Penang Island between September 2015 to September 2016. The abundance of Aedes mosquitoes and their breeding habitat both indoor and outdoor were recorded. Aedes indices i.e. Container index (CI), House index (HI) and Breteau Index (BI) were calculated for dengue risk, besides the attraction and repulsion (RF) of 5 container type evaluation. Among a total of 2,415 potential habitats examined, 638 were found positive for immature stages of Aedes. A total of 23,319 immatures were collected from the selected areas. Aedes albopictus (93.7%) was the dominant species followed by Aedes aegypti (5.8%) and others (0.5%). Among the 5 container types, plastic type containers were the most productive (45.5%) whereas the natural containers (6.1%) were the least (P < 0.05). High values of Aedes indices showed that all selected localities are at risk of dengue due to high prevalence of Ae. albopictus. Rubber and natural type of containers were the most attractive breeding habitats for vectors of dengue. The results of this study provides an insight to the current distribution of dengue vectors, which may be crucial to the health authorities in vector management programmes in the future.

Lipopolysaccharide-induced memory impairment in rats: a model of Alzheimer's disease

Alzheimer's disease (AD) is a primary cause of dementia in the middle-aged and elderly worldwide. Animal models for AD are widely used to study the disease mechanisms as well as to test potential therapeutic agents for disease modification. Among the non-genetically manipulated neuroinflammation models for AD, lipopolysaccharide (LPS)-induced animal model is commonly used. This review paper aims to discuss the possible factors that influence rats' response following LPS injection. Factors such as dose of LPS, route of administration, nature and duration of exposure as well as age and gender of animal used should be taken into account when designing a study using LPS-induced memory impairment as model for AD.

Insight into potential mechanisms of hypobaric hypoxia-induced learning and memory deficit - Lessons from rat studies

Impairment of memory is one of the most frequently reported symptoms during sudden hypoxia exposure in human. Cortical atrophy has been linked to the impaired memory function and is suggested to occur with chronic high-altitude exposure. However, the precise molecular mechanism(s) of hypoxia-induced memory impairment remains an enigma. In this work, we review hypoxia-induced learning and memory deficit in human and rat studies. Based on data from rat studies using different protocols of continuous hypoxia, we try to elicit potential mechanisms of hypobaric hypoxia-induced memory deficit.

Determination and optimization of Vitamin B complex in xylanase enzyme treated polished rice by response surface methodology

The present study provides information about the concentrations of Vitamin B (thiamine, riboflavin, pyridoxine and niacin) in polished brown rice treated with xylanase. Xylanase enzyme was produced from Aspergillus awamori MTCC 9166. Brown rice was treated with 60-100% enzyme (40 ml of buffer -undiluted) for 30 to 150 min (with variation of 30 min) at 30 degrees C to 50 degrees C (with variation of 5 degrees C) to attain a saturated moisture level of 35.5 g100(-1)g .The enzyme acted upon selective degradation (polishing time 10-50 sec) of bran layer facilitating retention of more vital nutrients along with the vitamins. Vitamin B content, detected through HPLC and optimized by response surface methodology (RSM) with central composite design (CCRD), demonstrated that selective degradation of bran layers for polished rice facilitated increase of thiamine (57%), riboflavin (48%), pyridoxine (90%) and niacin (55%) concentration in bio polished rice over normally milled rice.Enzyme treated bio-polished rice was considered to be better source of vitamin B complex than mechanically milled rice, hence more nutritionally efficacious.

The Potential Role of Melatonin on Memory Function: Lessons from Rodent Studies

Pineal melatonin biosynthesis is regulated by the circadian clock located in the suprachiasmatic nucleus of the hypothalamus. Melatonin has been found to modulate the learning and memory process in human as well as in animals. Endogenous melatonin modulates the process of newly acquired information into long-term memory, while melatonin treatment has been found to reduce memory deficits in elderly people and in various animal models. However, the mechanisms mediating the enhancing effect of melatonin on memory remain elusive. This review intends to explore the possible mechanisms by looking at previous data on the effects of melatonin treatment on memory performance in rodents.

Clinical drug interactions: a holistic view

Every time a drug is administered to the animal to treat an ailment, no matter whether it is acute or chronic manifestation, it usually goes together with some other prescription medicine, OTC (Over the counter) formulation, herbs or even food. All the xenobiotics such as drugs, toxins and food components as well as the endogenous compound that are formed in the animal body as a routine phenomenon exert a stimulatory or inhibitory effect on the different physiological and biochemical processes going in the body. These effects may alter the normal metabolism and/or drug transport or its efficacy drastically and thus expose the man and animals to the risk of a potentially dangerous interaction. The present review discusses these potential reactions and their mechanisms that help in navigating the hazardous combinations of drugs with other medicines, food, herbs, vitamins and minerals with confidence.

Measurement of bioelectric and acoustic profile of breast tissue using hybrid magnetoacoustic method for cancer detection

This paper proposes a novel hybrid magnetoacoustic measurement (HMM) system aiming at breast cancer detection. HMM combines ultrasound and magnetism for the simultaneous assessment of bioelectric and acoustic profiles of breast tissue. HMM is demonstrated on breast tissue samples, which are exposed to 9.8 MHz ultrasound wave with the presence of a 0.25 Tesla static magnetic field. The interaction between the ultrasound wave and the magnetic field in the breast tissue results in Lorentz Force that produces a magnetoacoustic voltage output, proportional to breast tissue conductivity. Simultaneously, the ultrasound wave is sensed back by the ultrasound receiver for tissue acoustic evaluation. Experiments are performed on gel phantoms and real breast tissue samples harvested from laboratory mice. Ultrasound wave characterization results show that normal breast tissue experiences higher attenuation compared with cancerous tissue. The mean magnetoacoustic voltage results for normal tissue are lower than that for the cancerous tissue group. In conclusion, the combination of acoustic and bioelectric measurements is a promising approach for breast cancer diagnosis.

Pharmacokinetics of diclofenac and its interaction with enrofloxacin in sheep

The pharmacokinetics of diclofenac was investigated in sheep given diclofenac alone (1mgkg(-1), i.v. or i.m.) and in combination with enrofloxacin (5mgkg(-1), i.v.). The plasma concentration-time data following i.v. administration of diclofenac was best described by a two compartment open pharmacokinetic model. The elimination half-life (t(1/2beta)), area under concentration-time-curve (AUC), volume of distribution (Vd(area)), mean residence time (MRT) and total body clearance (Cl(B)) were 1.03+/-0.18h, 12.17+/-1.98microg h ml(-1), 0.14+/-0.02Lkg(-1), 1.36+/-0.16h and 0.10+/-0.02Lkg(-1)h(-1), respectively. Following i.m. administration of diclofenac alone and in conjunction with enrofloxacin, the plasma concentration-time data best fitted to a one compartment open model. The t(1/2beta), AUC, Vd(area), MRT and Cl(B) were 1.33+/-0.10h, 7.32+/-1.01microg h mL(-1), 0.13+/-0.01Lkg(-1) and 0.07+/-0.01Lkg(-1)h(-1), respectively. Co-administration of enrofloxacin did not affect Vd(area) and MRT but absorption rate constant (K(a)), beta, t1/2Ka, t1/2beta, AUC, AUMC, Cl(B) and bioavailability (F) were significantly increased. This may be due to direct inhibition of cytochrome P(450) isozymes by enrofloxacin. A dose of 1.4mgkg(-1) of diclofenac administered every 6h may be appropriate for use in sheep.

Removal of chromium and pentachlorophenol from tannery effluents

Three bacterial strains, including one Acinetobacter sp. PCP3, grown in the presence of minimal salt medium and pentachlorophenol (PCP) as sole carbon source in the chemostat showed higher utilization of PCP and adsorption of chromium. In sequential bioreactor, tannery effluents treated initially by bacterial consortium followed by fungus removed 90% and 67% chromium and PCP respectively, whereas in another set of bioreactor in which effluents was treated initially by fungi followed by bacteria could remove 64.7% and 58% chromium and PCP, respectively.

Effect of aqueous Euphorbia hirta leaf extract on gastrointestinal motility

The aqueous leaf extract of Euphorbia hirta decreased the gastrointestinal motility in normal rats and decreased the effect of castor oil-induced diarrhoea in mice.

Pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in goats given enrofloxacin alone and in combination with probenecid

The pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin were investigated in goats given enrofloxacin alone or in combination with probenecid. Enrofloxacin was administered i.m. at a dosage of 5 mg x kg(-1) alone or in conjunction with probenecid (40 mg x kg(-1), i.v.). Blood samples were drawn from the jugular vein at predetermined time intervals after drug injection. Plasma was separated and analysed simultaneously for enrofloxacin and ciprofloxacin by reverse-phase high performance liquid chromatography. The plasma concentration-time data for both enrofloxacin and ciprofloxacin were best described by a one-compartment open pharmacokinetic model. The elimination half-life (t(1/2beta)), area under the plasma concentration-time curve (AUC), volume of distribution (V(d(area))), mean residence time (MRT) and total systemic clearance (Cl(B)) were 1.39 h, 7.82 microg x h x mL, 1.52 L x kg(-1), 2.37 h and 802.9 mL x h(-1) x kg(-1), respectively. Enrofloxacin was metabolized to ciprofloxacin in goats and the ratio between the AUCs of ciprofloxacin and enrofloxacin was 0.34. The t(1/2beta), AUC and MRT of ciprofloxacin were 1.82 h, 2.55 microg x h x mL and 3.59 h, respectively. Following combined administration of probenecid and enrofloxacin in goats, the sum of concentrations of enrofloxacin and ciprofloxacin levels > or = 0.1 microg x mL(-1) persisted in plasma up to 12 h.Co-administration of probenecid did not affect the t(1/2beta), AUC, V(d (area)) and Cl(B) of enrofloxacin, whereas the values of t(1/2beta) (3.85 h), AUC (6.29 microg x h x mL), MRT (7.34 h) and metabolite ratio (0.86) of ciprofloxacin were significantly increased. The sum of both enrofloxacin and ciprofloxacin levels was > or = 0.1 microg x mL(-1) and was maintained in plasma up to 8 h in goats after i.m. administration of enrofloxacin alone. These data indicate that a 12 h dosing regime may be appropriate for use in goats.

Pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin after intramuscular administration of enrofloxacin in goats

The pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin were investigated in goats after a single intramuscular administration of enrofloxacin at 2.5 mg/kg body weight. The plasma concentrations of enrofloxacin and ciprofloxacin were determined simultaneously by a HPLC method. The peak concentrations (Cmax) of enrofloxacin (1.13 microg/ml) and ciprofloxacin (0.24 microg/ml) were observed at 0.8 and 1.2 h, respectively. The elimination half-life (t1/2beta), volume of distribution (Vd(area)), total body clearance (Cl(B)) and mean residence time (MRT) of enrofloxacin were 0.74 h, 1.42 L/kg, 1329 ml/h per kg and 1.54 h, respectively. The t1/2beta, area under the plasma concentration-time curve (AUC) and the MRT of ciprofloxacin were 1.38 h, 0.74 microg h/ml and 2.73 h, respectively. The metabolic conversion of enrofloxacin to ciprofloxacin was appreciable (36%) and the sum of the plasma concentrations of enrofloxacin and ciprofloxacin was maintained at or above 0.1 microg/ml for up to 4 h. Enrofloxacin appears to be useful for the treatment of goat diseases associated with pathogens sensitive to this drug.

Effects of endotoxin-induced fever and probenecid on disposition of enrofloxacin and its metabolite ciprofloxacin after intravascular administration of enrofloxacin in goats

Pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin were investigated in normal, febrile and probenecid-treated adult goats after single intravenous (i.v.) administration of enrofloxacin (5 mg/kg). Pharmacokinetic evaluation of the plasma concentration-time data of enrofloxacin and ciprofloxacin was performed using two- and one-compartment open models, respectively. Plasma enrofloxacin concentrations were significantly higher in febrile (0.75-7 h) and probenecid-treated (5-7 h) goats than in normal goats. The sum of enrofloxacin and ciprofloxacin concentrations in plasma > or =0.1 microg /mL was maintained up to 7 and 8 h in normal and febrile or probenecid-treated goats, respectively. The t1/2beta, AUC, MRT and ClB of enrofloxacin in normal animals were determined to be 1.14 h, 6.71 microg .h/mL, 1.5 h and 807 mL/h/kg, respectively. The fraction of enrofloxacin metabolized to ciprofloxacin was 28.8%. The Cmax., t1/2beta, AUC and MRT of ciprofloxacin in normal goats were 0.45 microg /mL, 1.79 h, 1.84 microg .h/mL and 3.34 h, respectively. As compared with normal goats, the values of t1/2beta (1.83 h), AUC (11.68 microg ? h/mL) and MRT (2.13 h) of enrofloxacin were significantly higher, whereas its ClB (430 mL/h/kg) and metabolite conversion to ciprofloxacin (8.5%) were lower in febrile goats. The Cmax. (0.18 microg /mL) and AUC (0.99 microg .h/mL) of ciprofloxacin were significantly decreased, whereas its t1/2beta (2.75 h) and MRT (4.58 h) were prolonged in febrile than in normal goats. Concomitant administration of probenecid (40 mg/kg, i.v.) with enrofloxacin did not significantly alter any of the pharmacokinetic variables of either enrofloxacin or ciprofloxacin in goats.

Malaria and Anopheles mosquitos in Malaysia

Until today, malaria is still one of the most important diseases in Malaysia. This is because Malaysia is located within the equatorial zone with high temperatures and humidities, usually important for the transmission of malaria. The number of malaria cases were estimated to be around 300,000 before the launching of the Malaria Eradication Program (MEP). The program was successful in reducing the numbers progressively during the 1967-1982 period. During the period 1980-1991, the highest number of malaria cases recorded for the country was 65,283 in 1989 (16,902 in Peninsular Malaysia, 47,545 in Sabah and 836 in Sarawak) whilst the lowest was 22,218 (10,069 in Peninsular Malaysia, 11,290 in Sabah and 859 in Sarawak) in 1983. In Malaysia, there are 434 species of mosquitos, representing 20 genera. Of these, 75 species are Anopheles that comprise of 2 subgenus, i.e. Anopheles and Cellia. Of the 75 species, only 9 have been reported as vectors: An. maculatus, An balabacensis, An. dirus, An. letifer An. campestris, An. sundaicus, An. donaldi, An. leucophyrus and An. flavirostris. The behavior, seasonal abundance, biting activities and breeding sites of these species are discussed.

Pharmacokinetics of gentamicin following single dose intravenous administration in normal and febrile goats

A pharmacokinetic study of gentamicin (5 mg/kg intravenous (i.v.)) was conducted first in clinically healthy female goats and then in the same goats after induction of fever by Escherichia coli endotoxin (0.2 microgram/kg i.v.). Rectal temperature increased 1 degrees to 1.5 degrees C in febrile goats. Differences in the blood serum concentrations of gentamicin were not observed at any time between febrile and normal goats. The disposition kinetics of gentamicin were described by a biexponential expression CP = Ae-alpha t + Be-beta t. Median values for the half-lives of gentamicin were 103.6 min in normal and 136.0 min in febrile goats. The apparent volume of distribution (Vd) was 263.3 ml/kg in the febrile goats which was not different from that in the normal goats (240.6 ml/kg). The volume of the central compartment (Vc) was almost identical in normal and febrile goats. The body clearance (Cl beta) was observed to be 1.7 and 1.6 ml/min.kg in normal and febrile goats, respectively. Dosage regimens for gentamicin were calculated on the basis of median kinetic data.