Optical and electronic properties of MgPc-Ch-diisoQ blend organic thin film as an active layer for photovoltaic cells

Organic photovoltaic cells are a promising technology for generating renewable energy from sunlight. These cells are made from organic materials, such as polymers or small molecules, and can be lightweight, flexible, and low-cost. Here, we have created a novel mixture of magnesium phthalocyanine (MgPc) and chlorophenyl ethyl diisoquinoline (Ch-diisoQ). A coating unit has been utilized in preparing MgPc, Ch-diisoQ, and MgPc-Ch-diisoQ films onto to FTO substrate. The MgPc-Ch-diisoQ film has a spherical and homogeneous surface morphology with a grain size of 15.9 nm. The optical absorption of the MgPc-Ch-diisoQ film was measured, and three distinct bands were observed at 800-600 nm, 600-400 nm, and 400-250 nm, with a band gap energy of 1.58 eV. The current density-voltage and capacitance-voltage measurements were performed to analyze the photoelectric properties of the three tested cells. The forward current density obtained from our investigated blend cell is more significant than that for each material by about 22%. The photovoltaic parameters (Voc, Isc, and FF) of the MgPc-Ch-diisoQ cell were found to be 0.45 V, 2.12 μA, and 0.4, respectively. We believe that our investigated MgPc-Ch-diisoQ film will be a promising active layer in organic solar cells.

Congenital diarrhea in a newborn infant: A case report

BACKGROUND

Microvillus inclusion disease (MVID) is a rare autosomal recessive cause of severe congenital diarrhea with significant morbidity and mortality. Definitive treatment involves bowel transplant. The diagnosis of this condition can be challenging and a few genetic panels are available for the identification of the most common mutations. We present the case of an infant with MVID due to a mutation not reported in the literature before.

CASE SUMMARY

We report the case of an infant transferred to our institution with severe diarrhea of unknown etiology, failure to thrive, and significant metabolic derangements. An extensive work-up including stool studies for common gastrointestinal pathogens, abdominal ultrasound, esophagogastroduodenoscopy with duodenal biopsy and flexible sigmoidoscopy failed to reveal a diagnosis. Multiple dietary and formula regimens were introduced but all resulted in voluminous diarrhea. She remained on total parenteral nutrition (TPN) for the duration of her hospital stay. Genetic testing was done and she was subsequently found to have a novel mutation in the MYO5B gene [homozygous mutation for MYO5B c.1462del, p. (Ile488Leufs*93)] giving us the diagnosis of MVID. She remains on TPN while awaiting bowel transplant at the time of the compilation of this case report.

CONCLUSION

We report a novel mutation involved in MVID and highlight the importance of considering this disease when faced with a newborn presenting with life threatening diarrhea. At the time of this publication, 232 allelic variations of this gene (MIM#606540) exist in National Center for Biotechnology Information's database. Our patient's mutation has not been reported in literature as a cause of MVID.

Improvement in Infection Prevention and Control Measures at The Children Hospital, Lahore. A My Child Matters Collaborative Project

Background: Overcrowding, lack of operational funds, and healthcare associated infections are major challenges at the Children Hospital Lahore, a public healthcare facility in Pakistan with 900 new pediatric cancer admissions annually. In 2014, a collaboration between My Child Matters (MCM), St. Jude Global Infectious Diseases Program (SJ-GID), and our institution was established to address these issues. Aim: To describe the effect of a collaborative improvement strategy on the infection prevention and control (IPC) standards in a pediatric oncology unit in a resource-limited setting. Methods: Our study was a prospective before-and-after study. We compare the WHO Hand Hygiene Self-Assessment Framework (HHSAF) and 4 modules of the St. Jude modified Infection Control Assessment Tool (ICAT) scores. Our strategy included: (1) creating a multidisciplinary team of pediatric hematology-oncology, infectious disease physicians, nurses, microbiologist, and a data manager, (2) engaging on monthly online IPC mentoring sessions with the SJ-GID and MCM mentors, (3) performing daily inpatient healthcare associated (HAI) surveillance rounds, and (4) providing regular hand hygiene training and compliance audits. Results: Our hand hygiene facility level per WHO scores increased from “Inadequate” during the baseline assessment to “Intermediate/Consolidation” by the end of 3-year implementation (122 vs 352 HHSAF scores). The sink: bed and hand sanitizer: bed ratios improved to 1:6 and 1:1 respectively. Six washrooms were added to our unit. ICAT general infection control module increased by 40% (45 vs 78 ICAT score) and hygiene compliance improved by 20% from baseline. Identification of HAI increased from baseline (4.07 vs 8.7 infections per 1000 patient days). A 25% of the isolates were multidrug-resistant microorganisms. Conclusion: Implementing a collaborative improvement strategy improved the IPC standards in our pediatric cancer center. The increase of HAI might be a result of a better surveillance and laboratory identification. Further targeted interventions should be develop to decrease HAI rates and infection-related morbidity and mortality in our population.

Clinically significant anatomical variation of the retropharyngeal internal carotid arteries

Although interpatient variations in the course and anatomy of extracranial internal carotid arteries (EICAs) have been described previously, intrapatient variability is rarely cited in the literature. Distance between EICAs and the pharyngeal wall is an important determinant of vascular injury risk. A retropharyngeal EICA has crucial implications in patients undergoing pharyngeal procedures, and important in otorhinolaryngology and emergency medicine. Surgical exploration without identification of anatomical landmarks, or emergent intubation in the emergency room poses high risk for EICA injury. Other critical clinical considerations include intra-arterial involvement of tonsillitis, peritonsillar abscesses, or parapharyngeal neoplasms due to close proximity to the EICA. We present 2 cases with short-term change in retropharyngeal course of EICA to highlight this further. Although no clear etiology for these changes has been identified, we hypothesize that embryology, weight alterations, atherosclerotic disease, and postradiation changes are contributory. Thus, one radiologic study does not exclude variation in vascular anatomy.

Modelling and characterisation of a ultrasound-actuated needle for improved visibility in ultrasound-guided regional anaesthesia and tissue biopsy

Clear needle visualisation is recognised as an unmet need for ultrasound guided percutaneous needle procedures including regional anaesthesia and tissue biopsy. With inadequate needle visibility, these procedures may result in serious complications or a failed operation. This paper reports analysis of the modal behaviour of a previously proposed ultrasound-actuated needle configuration, which may overcome this problem by improving needle visibility in colour Doppler imaging. It uses a piezoelectric transducer to actuate longitudinal resonant modes in needles (outer diameter 0.8-1.2mm, length>65mm). The factors that affect the needle's vibration mode are identified, including the needle length, the transducer's resonance frequency and the gripping position. Their effects are investigated using finite element modelling, with the conclusions validated experimentally. The actuated needle was inserted into porcine tissue up to 30mm depth and its visibility was observed under colour Doppler imaging. The piezoelectric transducer is able to generate longitudinal vibration with peak-to-peak amplitude up to 4μm at the needle tip with an actuating voltage of 20Vpp. Actuated in longitudinal vibration modes (distal mode at 27.6kHz and transducer mode at 42.2kHz) with a drive amplitude of 12-14Vpp, a 120mm needle is delineated as a coloured line in colour Doppler images, with both needle tip and shaft visualised. The improved needle visibility is maintained while the needle is advanced into the tissue, thus allowing tracking of the needle position in real time. Moreover, the needle tip is highlighted by strong coloured artefacts around the actuated needle generated by its flexural vibration. A limitation of the technique is that the transducer mode requires needles of specific lengths so that the needle's resonance frequency matches the transducer. This may restrict the choice of needle lengths in clinical applications.

Clinical management of dietary induced urolithiasis associated with balanoposthitis in a Boer goat

A Boer-Kajang cross male goat was presented to the Veterinary Hospital, University Malaysia Kelantan with a history of dysuria, hematuria and restlessness. The goat was intensively managed (confined to the pen) and fed with only palm kernel cake for the last three months. Physical examination revealed that the goat was dull, depressed, having an inflamed penis and prepuce with blood stained urine dripping from the penis. The differential diagnoses were obstructive urolithiasis, urinary tract infection and balanoposthitis. Based on the history, clinical signs, physical examination, urinalysis, ultrasonagraphy and feed analysis, the goat was diagnosed with obstructive urolithiasis and balanoposthitis. Treatment was instituted by amputation of the urethral process and retrograde urohydropulsion to relieve the blockade. Sulfadiazine-trimethoprim (Norodine®24) 15mg/kg, I.M; flunixin meglumine 2.2mg/kg, I.M; vitamin B complex 1ml/10kg, I.M and ammonium chloride 300mg/kg orally were administered. The goat responded well to treatment and was recovering well during a follow up visit.

Hypoxia modulates the activity of a series of clinically approved tyrosine kinase inhibitors

BACKGROUND AND PURPOSE

Hypoxia in tumours is known to cause resistance to conventional chemotherapeutic drugs. In contrast, little is known about the effects of hypoxia on targeted anti-cancer drugs. This study evaluated the effect of hypoxia on a series of clinically approved tyrosine kinase inhibitors (TKIs).

EXPERIMENTAL APPROACH

The effect of hypoxia (0.1% oxygen) on the activity of conventional cytotoxic drugs (5-fluorouracil, doxorubicin and vinblastine), the hypoxia-activated prodrug tirapazamine and 9 TKIs was determined in a panel of cell lines. Where hypoxia had a marked effect on chemosensitivity, Western blot analysis was conducted to determine the effect of hypoxia on target expression and the effect of TKIs on cell signalling response under aerobic and hypoxic conditions.

KEY RESULTS

Three patterns of chemosensitivity were observed: resistance under hypoxia, equitoxic activity against hypoxic and aerobic cells, and preferential cytotoxicity to hypoxic cells. Significant hypoxia selectivity (independent of HIF1) was observed in the case of dasatinib and this correlated with the ability of dasatinib to inhibit phosphorylation of Src at tyrosine 530. Sorafenib was significantly less effective under hypoxic conditions but resistance did not correlate with hypoxia-induced changes in Raf/MEK/ERK signalling.

CONCLUSIONS AND IMPLICATIONS

Hypoxia influences the activity of TKIs but in contrast to conventional cytotoxic drugs, preferential activity against hypoxic cells can occur. The search for hypoxia-targeted therapies has been long and fruitless and this study suggests that some clinically approved TKIs could preferentially target the hypoxic fraction of some tumour types.

Investigating the Catalytic Activity of Monoclinic Zirconia; Oxidation of Benzyl Alcohol in Aqueous Medium at Mild Conditions

The oxidation/degradation of benzyl alcohol in artificially contaminated water under atmospheric pressure by molecular oxygen/air over ZrO2(m) catalyst was investigated. Monoclinic phase ZrO2 was synthesized and characterized by modern techniques. Oxidation of benzyl alcohol in aqueous medium was carried out in a typical three necked double walled batch reactor equipped with thermometer and condenser. The rate of oxidation was affected by different reaction parameters such as speed of agitation, catalyst loading, temperature, concentration of substrate solution (46.3 – 185 mmol/L) and partial pressure of oxygen. Major products were detected with GC and UV spectrophotometer. Optimal conditions were setup for better catalytic activity of ZrO2(m). To sum up, catalytic oxidation of benzyl alcohol in aqueous medium by ZrO2(m) is a useful and cheaper method for the conversion of benzyl alcohol to valuable products as well as for the removal of benzyl alcohol from industrial waste water.

Removal of Triphenylmethane Dye from Aqueous Solution by Carbonaceous Adsorbent

Removal of acid blue 1 from aqueous solution on activated carbon produced from Salvadora oleoides was investigated. The samples were characterized by BET surface area, BJH pore volume and pore diameter, XRD, SEM, EDS and FTIR analysis. The surfaces contain functional groups like ketones and hydroxyl which disappeared at high activation temperature; relatively high amount of carbon w.r.t. oxygen was found with the increase in activation temperature; the increase in surface area and development of porous structures showed a positive effect on the adsorption capacity. Adsorption of the dye on carbon at 10 and 45°C showed that the first order, Bangham and Elovich and parabolic diffusion equations apply to the kinetic data. The adsorption rate increased with the temperature and with thermal activation of the sample. Thermodynamic parameters like ΔE≠, ΔH≠, ΔS≠ and ΔG≠ were calculated from the kinetic data. The negative values of ΔS≠ reflect decrease in the disorder of the system at the solid-solution interface during adsorption. Gibbs free energy (ΔG≠), which represents the driving force for the affinity of dye for the carbon, increased with the increase in activation temperature.

Investigating the Activity of Zirconia as a Catalyst and a Support for Noble Metals, in Green Oxidation of Cyclohexane

Green oxidation of cyclohexane by molecular oxygen was carried out over ZrO2 and noble metals (Pd and Pt) supported on zirconia in solvent free conditions. Studies have been carried out in a typical three-necked batch reactor. Reaction products were identified by GC and UV spectrophotometer. Reaction rates were determined as a function of temperature, partial pressure of oxygen, amount of catalyst, volume of reactants, agitation and reaction duration. The agitation effect and activation energy revealed the absence of mass transfer resistance. Experimental results unveiled the effect of morphology of ZrO2 on catalysis. 1.0 wt.% noble metal/ZrO2(m) was found more selective for cyclohexanol production at low temperature, agitation 900rpm and partial pressure of 101.325 KPa while at high temperature cyclohexanol was further oxidized to cyclohexanone. Comparison of Pt/ZrO2 and Pd/ZrO2 catalysts was made on the basis of reactivity and selectivity. Catalysts were characterized by using BET surface area and pore size analyzer, XRD and SEM. To conclude shortly, for the oxidation of cyclohexane, platinum or palladium supported on zirconia are selective, recyclable and could behave as truly heterogeneous catalysts.

Prevalence of rheumatic heart disease in school children of urban Lahore

OBJECTIVE

To determine the prevalence of rheumatic heart disease (RHD) among school children in urban and semiurban areas of Lahore, Pakistan.

METHODS

A cross-sectional survey of school children aged 5-15 years from 70 schools of urban and semiurban Lahore was carried out by a team of cardiologists. Children were screened by clinical examination and diagnosis confirmed by echocardiography. Sociodemographic data were also collected.

RESULTS

Of 24 980 children screened, 986 (3.9%) had a confirmed cardiac lesion; 546 had RHD, 440 had congenital heart disease. The prevalence of RHD was 21.9/1000 children screened (95% CI 20.1 to 23.7). Their mean (SD) age was 10.7 (2.6) years and the female:male ratio was 1.6:1. Most (92.5%) were unaware of the diagnosis and less than 2% were taking rheumatic prophylaxis. All children belonged to a low socioeconomic group and 67% were undernourished.

CONCLUSION

The prevalence of RHD in the urban school population of Lahore is among the highest in the world. The younger age of onset is a special feature and most are unaware of the diagnosis, and hence not receiving life-saving secondary prophylaxis.

Multiple bilateral cannon-ball lung metastases from carcinoma of the prostate: orchiedectomy induced remission

A 56-year-old man presented with lower urinary tract obstructive symptoms, hemoptysis and progressive dyspnoea. Digital rectal examination showed an enlarged nodular prostate and a tru-cut biopsy confirmed carcinoma prostate. Chest x-ray showed multiple bilateral cannon ball opacities suggestive of metastases. He underwent bilateral orchidectomy and follow up assessment showed significant clearing of the cannon-ball lesions in the lungs. He remained asymptomatic at follow up that has extended to 8 years.

Infective endocarditis in children--incidence, pattern, diagnosis and management in a developing country

BACKGROUND

In developing countries, patients with infective endocarditis are referred late, there is low yield of blood cultures and incidence of rheumatic heart disease is still high.

OBJECTIVE

Evaluate clinical pattern, assess diagnostic criteria in our settings and determine outcome.

SETTING

A tertiary referral center for paediatric and adult cardiology.

PATIENTS AND METHODS

All children with infective endocarditis admitted to a single center from April 1997 to March 2000 were analysed. The diagnosis was based on Duke's criteria, which proposed two major and six minor criteria. Minor criteria were expanded to include raised acute phase reactants and presence of newly diagnosed or increasing splenomegally. The patients were stratified as definite, possible and rejected cases.

RESULTS

Of 1402 hospital admissions, 45 patients fulfilled the diagnostic criteria for infective endocarditis giving an incidence of 32 per 1000 hospital admissions. The mean age was 7.9 +/- 4 years (4 months to 16 years) with only two patients under 1 year of age. Rheumatic heart disease was the underlying lesion in 24 patients (53%) while congenital heart lesions occurred in 20 patients (45%). Previous antibiotic treatment was given in 26 patients (58%) definitely. Blood cultures were positive in 21 patients (47%); Streptococcus Viridans being the most common organism, while vegetations on echocardiography were present in 32 patients (71%). Surgery was undertaken in four patients and five patients left against medical advise. Of 10 patients with aortic valve involvement, there were three deaths (30%) and overall mortality was 13% (six patients).

CONCLUSIONS

The incidence of infective endocarditis is 32 per 1000 (3.2%) hospital admissions in a tertiary paediatric cardiology referral center. Rheumatic heart disease is still the most common underlying heart lesion. Blood cultures are positive in less than 50% of cases and echocardiography in expert hands is a more sensitive tool in our set up. Mortality is still high and aortic valve involvement in particular, carried poor prognosis.

Successful occlusion of a coronary arteriovenous fistula using an Amplatzer duct occluder

In an 11-year old boy with a large coronary arteriovenous fistula between the left coronary artery and the right atrium, we achieved successful closure using a 10-8 Amplatzer Duct Occluder introduced from the right internal jugular vein. Angiography 6 weeks later showed complete occlusion of the fistula, with normal opacification of the left coronary arterial system. This technique may be used as an alternative to coils and surgery in selected patients.

Hypotensive action of coumarin glycosides from Daucus carota

Daucus carota (carrot) has been used in traditional medicine to treat hypertension. Activity-directed fractionation of aerial parts of D. carota resulted in the isolation of two cumarin glycosides coded as DC-2 and DC-3. Intravenous administration of these compounds caused a dose-dependent (1-10 mg/kg) fall in arterial blood pressure in normotensive anaesthetised rats. In the in vitro studies, both compounds caused a dose-dependent (10-200 microg/ml) inhibitory effect on spontaneously beating guinea pig atria as well as on the K+ -induced contractions of rabbit aorta at similar concentrations. These results indicate that DC-2 and DC-3 may be acting through blockade of calcium channels and this effect may be responsible for the blood pressure lowering effect of the compounds observed in the in vivo studies.

Management and outcome of infants and children with right atrial isomerism

OBJECTIVES

To assess the current results and outcome of surgery in infants and children with right atrial isomerism and complex congenital heart disease.

SETTING

Tertiary referral centre.

METHODS

20 consecutive children with right atrial isomerism and complex congenital heart disease underwent surgery over a 6 year period between August 1987 and July 1993. The results and outcome were analysed according to age, presentation, and surgical procedures.

RESULTS

Patients were divided into two groups depending on age at presentation and initial surgery: group A comprised 11 patients who required surgical intervention in the first month of life (mean age 5 days); and group B comprised nine patients who required initial surgical intervention after the first month of life (mean age 6.8 months). Seven (64%) of the 11 patients in group A had obstructed pulmonary venous drainage and ten (91%) had pulmonary atresia. There were seven early deaths (64%), including the five patients who required systemic to pulmonary artery shunt and simultaneous repair of obstructed pulmonary veins. The long-term survival rate in this group was 18% (two of 11). Pulmonary venous obstruction was present in two (22%) of the nine patients in group B and four (44%) had pulmonary atresia. There were no early deaths. One patient died after a second palliative procedure. There was one late sudden death. Four patients had a Fontan operation with no deaths. Two of the remaining three patients meet the Fontan criteria. The long-term survival rate in this group was 78% (seven of nine).

CONCLUSIONS

Surgical management of patients with right atrial isomerism who have complex congenital heart disease carries a high mortality and remains palliative. The overall survival rate was 45% (nine of 20); 18% in patients requiring surgery in the first month of life (group A) and 78% in patients requiring surgery after the first month of life (group B) (P < 0.001). Of the total of 20 patients, nine were potential candidates for a Fontan operation. Seven of these have undergone a Fontan procedure with five survivors.

Late systemic desaturation after total cavopulmonary shunt operations

OBJECTIVES

To assess the medium-term results of total cavopulmonary shunt operations in children with left atrial isomerism, interrupted inferior vena cava, and complex congenital heart defects.

BACKGROUND

Creation of a total cavopulmonary shunt provides very good interim palliation for children with interrupted inferior vena cava and complex congenital heart disease; however, longer term results after this operation have not been reported.

METHODS

Detailed follow up of six children who underwent creation of a total cavopulmonary shunt at a tertiary referral centre.

RESULTS

There were no early or late deaths. Oxygen saturations at discharge ranged from 89% to 92% (mean 90%). At last follow up (mean 4.7 years) saturations at rest ranged from 73% to 81% (mean 77%) (P < 0.05). All patients underwent exercise stress testing. At peak exercise oxygen saturations ranged from 62% to 87% (mean 71.5%) and during recovery from 68% to 85% (mean 78%). Cardiac catheterisation was performed in five patients with saturations of less than 80% at rest or peak exercise. No patient had pulmonary arteriovenous fistula. Systemic venous to hepatic venous collaterals were documented in four patients. These were localised below the diaphragm in three and above the diaphragm in one patient. The collateral vessel was successfully embolised in three of these patients, with a rise in resting oxygen saturations from 6 to 10% (mean 7%).

CONCLUSIONS

The development of systemic venous to hepatic venous collaterals is a common complication in patients who undergo a total cavopulmonary shunt operation. This can lead to significant desaturation at rest and during exercise. Detailed angiographic studies of the infradiaphragmatic system veins is required for diagnosis. Transcatheter embolisation of such vessels gives good relief.

Endocarditis with multiple intracardiac shunts: identification and repair

An 8-year-old boy who suffered from Hirschsprung's disease had development of tricuspid valve endocarditis that progressed to aortic root abscess formation, development of a fistulous communication between aorta and right atrium, atrial and ventricular septal defects, and a left ventricle to right atrium defect. Several surgical procedures were required. Operation consisted initially of closure of the septal defects and aortic valve repair. This was followed by homograft replacement of the aortic valve for persistent infection, and further closure of a left ventricle to right atrium fistula.

Influence of ethnic origin on the pattern of congenital heart defects in the first year of life

OBJECTIVE

To assess the prevalence and patterns of congenital heart defects in infants requiring hospital admission in a defined population and to determine the differences in ethnic groups.

DESIGN

A three year retrospective analysis of all hospital admissions for paediatric congenital heart defects in a single centre.

SETTING

Tertiary referral centre for infant cardiac services in the West Midlands region, United Kingdom.

PATIENTS AND METHODS

Indian, Pakistani, Bangladeshi and other individuals from the Indian subcontinent constitute 5.8% of the total population of the West Midlands region. Some 9% of infants, however, are Asian because of a high birth rate. All infants with confirmed congenital heart defects resident in this region who required hospital admission between April 1990 and March 1993 were classified as Asians and non-Asian, mainly white, infants.

RESULTS

Of 1111 infants with congenital heart defects born in the West Midlands and admitted to the hospital, 17.0% were Asian, significantly more than the percentage of Asian infants in the population (P < 0.0001). Asian infants had a higher proportion of complex congenital heart disease (7% v 2.1%, P < 0.001), whereas coarctation of the aorta was more common in non-Asian (3% v 9.1%, P = 0.003). Persistent arterial duct seemed to be more common in Asian children (16% v 10%, NS), but this group included preterm infants admitted for duct ligation. There was no significant difference between the two groups in the other nine categories of congenital heart defects.

CONCLUSIONS

The estimated prevalence of congenital heart defects requiring hospital admission was higher in Asian infants than in non-Asian (9.45 per 1000 v 4.56 per 1000, P < 0.0001). Complex congenital heart defects were more common in Asian infants whereas coarctation of the aorta was more common in non-Asian.

Effectiveness and safety of paediatric interventional cardiac catheterisation in a subregional cardiothoracic unit

OBJECTIVE

To assess the effectiveness and safety of paediatric interventional cardiac catheterization during the development of the service.

SETTING

Sub-regional Paediatric Cardiothoracic Centre.

PATIENTS AND METHODS

All paediatric admissions for cardiac catheterisation between January, 1985 and December, 1992. Data were collected on all patients in whom interventional cardiac catheterisation was performed excluding babies undergoing balloon atrial septostomy. Results were compared with those reported previously by the larger centres.

RESULTS

One hundred and seventy eight interventional procedures were performed in 158 patients, progressing from pulmonary valvuloplasty (1985) and aortic valvuloplasty (1986) to arterial duct occlusion and coil embolisation of shunts (1991). During the study period there was a rise in the number and variety of conditions for which interventional cardiac catheterisation was performed. In terms of morbidity, mortality and technical success, results compared favourably with those published from larger centres.

CONCLUSIONS

Interventional cardiac catheterisation in children can be established effectively and safely in a relatively smaller set up.

Congenitally divided left atrium: diagnostic pitfalls in cross-sectional echocardiography

A 20-month-old patient with a previously diagnosed atrial septal defect presented with acute heart failure. The clinical and echocardiographic features at admission to hospital were of a congenitally partitioned left atrium. At surgery a medially displaced and infolded left atrial appendage together with infolded left atrial wall was found, which gave a false appearance of a left atrial 'membrane'. This unusual arrangement was subsequently correctly identified by transoesophageal echocardiography. It is speculated that the abnormal orientation of the appendage may have produced a physiologic and haemodynamic situation akin to anomalous drainage of the pulmonary veins, which would account for the clinical features in this patient.

False aneurysm of the right ventricular outflow tract after total correction of tetralogy of Fallot: diagnosis by echocardiography and successful repair by neck cannulation for cardiopulmonary bypass

A case of false aneurysm related to the left side of the heart with a connection to the right ventricular outflow tract was found by echocardiography after complete repair of tetralogy of Fallot. Cardiopulmonary bypass was established by cannulating the right internal jugular vein and the ipsilateral common carotid artery. The aneurysm was then excised and the right ventricular outflow tract reconstructed by direct sutures.

Developmental regulation of antisense-mediated gene silencing in Dictyostelium

In Dictyostelium, the expression of antisense transcripts has been successfully used to reduce or eliminate gene expression. In most cases this occurs on the level of RNA stability resulting in a loss of both sense and antisense transcript accumulation. We here show that the antisense effect is regulated during the developmental cycle, i.e., in certain developmental stages and under certain developmental conditions, complementary RNAs appear not to interact with each other, resulting in a failure to abolish expression of the gene of interest. We find that this is not only the case with artificially introduced antisense constructs but also with the endogenous, antisense-regulated PSV-A gene. Our data demonstrate that antisense-mediated gene silencing is conferred by a biochemical machinery that is subject to regulation in vivo. The results provide a basis to better understand this machinery and to dissect the components. They may also explain the failure of some antisense experiments in Dictyostelium and possibly in other organisms.

Bioaccumulation of nickel and vanadium by clams (Meretrix meretrix) living in different salinities along the Saudi coast of the Arabian Gulf

The objective of this study was to investigate bioaccumulation of nickel (Ni) and vanadium (V) in clams living in different salinity regimes along the Saudi coast of the Arabian Gulf. Several hundred clam (Meretrix meretrix), sediment, and seawater samples were collected from 12 locations. Concentrations of Ni and V were determined in these samples using an inductively coupled argon plasma analyzer. Concentrations of Ni and V in the clams varied between 0.35 and 2.61 mg kg(-1) and between 0.13 and 0.35 mg kg(-1) wet tissue, respectively. Analysis of variance of the data revealed significant (P<0.01) inter- and intra-station variations in Ni concentrations in clams. In contrast, the mean concentration of V in clams from all the stations were statistically similar. Correlation between the biometric characteristics of clams and Ni and V concentrations were not statistically significant. Significant (P<0.05) geographical variations in Ni and V concentrations in the sediment samples were found, with relatively higher concentrations in the northern part of the Gulf where there are many oil fields. Ni and V in the sediments were significantly (P<0.05) correlated, suggesting a common contamination source for these elements. Interactions between Ni and V in clams and sediment were poor.

Carbohydrate metabolism in liver cirrhosis

Patients with cirrhosis of liver are more prone to have accompanying diabetes mellitus. The present study was conducted to investigate various biochemical parameters in patients with hepatic cirrhosis without diabetes. In these patients blood pyruvate, total bilirubin and globulin levels were elevated as compared to normal individuals. In contrast serum albumin level declined significantly whereas no significant change was observed in the concentrations of blood glucose, total proteins, total lipids, urea and serum cholesterol. These studies confirm the previous reports that carbohydrate metabolism is deranged in hepatic cirrhosis which may lead to diabetes mellitus.

Quantitation of pharmacologically-induced penile erections: the value of radionuclide phallography in the objective evaluation of erectile haemodynamics

This study combines the pharmacologically-induced penile erection (PIPE) technique with radionuclide phallography (RNP) for the non-invasive study of penile haemodynamic changes during erection. Penile erections produced by the intracavernosal injections of two different vasoactive drugs, prostaglandin E1 (PGE1) and papaverine HCl (PPV) were assessed by quantitation of the dynamic RNP and parameters of erection were defined and compared. PGE1 intracavernosal injections were seen to elicit a better erectile response than PPV. Dynamic radionuclide phallography was performed using 99Tcm-labelled autologous RBCs in five normally potent volunteers, sixteen patients with psychogenic impotence, seven patients with vasculogenic impotence (three arteriogenic, four venous leakage) and one patient with neurogenic impotence. Physical parameters of erection including the penile length and circumference changes during erection and the erectile angle were compared with the indices of penile blood flow and volume derived through quantitation of the RNP. There was a close correlation between the penogram index (an index of penile blood volume) and penile circumference increase during erection (r = 0.77, p less than 10(-6). The erectile angle, a measure of penile rigidity, correlated strongly (r = 0.82, p less than 10(-6) with the flow index, a measure of penile blood volume. Patterns specific to various categories of impotence were observed and these aided in the diagnosis, especially in equivocal cases with a suboptimal clinical response to the intracavernosal injection. Quantitative RNP offers a non-invasive method which allows direct objective assessment of the erectile response providing several quantitative parameters for analysis.

Metal contamination of drinking water from corrosion of distribution pipes

The objectives of this study were to evaluate metal contamination of drinking water resulting from the corrosion of distribution pipes and its significance to human health. A community in Dhahran, which is served from its own desalination facilities, was chosen for this study. About 150 drinking water samples were collected and analyzed for metal concentrations using an inductively coupled argon plasma analyzer. It was found that copper, iron and zinc in the drinking water increased during its transportation from the desalination plant to the consumers. This increase was related to the length and material of distribution pipes. Concentrations of copper and zinc were increased during overnight storage of water in the appliances. Metal concentrations found in this study are discussed with reference to human health.

A study of various factors affecting digestion of fish tissue prior to mercury determination

The effect of temperature on digestion, the acid combination and their quantities, and the time required for digestion of fish tissue were investigated using Hamour (Epinephelus tauvina) body tissue. Concentrations of Hg in fish tissue digested for four hours at 80 +/- 2 degrees C and 95 +/- 2 degrees C were statistically similar and significantly higher than in tissue digested at 60 +/- 2 degrees C. Eight acid combinations were investigated as digestion media and a 1:2 mixture of concentrated HNO3:H2SO4 proved to be the best. A quantity of 15 ml of this digestion media were found to be sufficient to digest approximately two grams of wet fish tissue. The use of 25 ml of digestion media resulted in significantly reduced Hg concentration whereas 10 ml was not sufficient to digest two grams of fish tissue. A digestion period of four to six hours at 80 degrees C was sufficient to oxidize the fish tissue. However, a two hour digestion resulted in reduced Hg values. Mercury determinations made from the samples prepared by the best combination of all the experimental conditions showed a good agreement with those of samples prepared in Teflon Acid Digestion Bombs. This study has pointed the necessity of developing a uniform standard procedure for digesting fish tissue prior to Hg determinations.