Potential of La-Doped SrTiO3 Thin Films Grown by Metal-Organic Vapor Phase Epitaxy for Thermoelectric Applications

La-doped SrTiO3 thin films with high structural quality were homoepitaxially grown by the metal-organic vapor phase epitaxy (MOVPE) technique. Thermogravimetric characterization of the metal-organic precursors determines suitable flash evaporator temperatures for transferring the liquid source materials in the gas phase of the reactor chamber. An adjustment of the charge carrier concentration in the films, which is necessary for optimizing the thermoelectric power factor, was performed by introducing a defined amount of the metal-organic compound La(tmhd)3 and tetraglyme to the liquid precursor solution. X-ray diffraction and atomic force microscopy verified the occurrence of the pure perovskite phase exhibiting a high structural quality for all La concentrations. The electrical conductivity of the films obtained from Hall-effect measurements increases linearly with the La concentration in the gas phase, which is attributed to the incorporation of La3+ ions on the Sr2+ perovskite sites by substitution inferred from photoemission spectroscopy. The resulting structural defects were discussed concerning the formation of occasional Ruddlesden-Popper-like defects. The thermoelectric properties determined by Seebeck measurements demonstrate the high potential of SrTiO3 thin films grown by MOVPE for thermoelectric applications.

Influence of Sr deficiency on structural and electrical properties of SrTiO3 thin films grown by metal-organic vapor phase epitaxy

Homoepitaxial growth of SrTiO3 thin films on 0.5 wt% niobium doped SrTiO3 (100) substrates with high structural perfection was developed using liquid-delivery spin metal-organic vapor phase epitaxy (MOVPE). Exploiting the advantage of adjusting the partial pressures of the individual constituents independently, we tuned the Sr/Ti ratio of the gas phase for realizing, stoichiometric, as well as Sr deficient layers. Quantitative energy dispersive X-ray spectroscopy in a scanning transmission electron microscope confirm Sr deficiency of up to 20% in nominally off-stoichiometrically grown films. Our MOVPE process allows to grow such layers in phase pure state and without extended defect formation. Indications for oxygen deficiency could not be identified. Sr deficient layers exhibit an increased permittivity of ɛr = 202 and a larger vertical lattice parameter. Current-voltage characteristics (IVCs) of metal-oxide-semiconductor (Pt/SrTiO3/SrTiO3:Nb) structures reveal that Sr deficient SrTiO3 films show an intrinsic resistive switching with on-off ratios of three orders of magnitude at RT and seven orders of magnitude at 10 K. There is strong evidence that a large deviation from stoichiometry pronounces the resistive switching behavior. IVCs conducted at 10 K indicate a defect-based mechanism instead of mass transport by ion diffusion. This is supported by in-situ STEM investigations that show filaments to form at significant higher voltages than those were resistive switching is observed in our samples.

Hypertriglyceridemia associated with eruptive xanthomas and lipemia retinalis in newly diagnosed diabetes mellitus

Severe hypertriglyceridemia can cause the deposit of lipids in the dermis (eruptive xanthomas) and in the retina (lipemia retinalis). Lipemia retinalis and eruptive xanthoma are occasionally seen in patients with diabetes mellitus and are thought to be due to abnormalities in the serum lipid fractions. Here a 15 year's old girl presented with typical symptoms of diabetes with skin lesions over hands and feet. On examination skin lesions were non-tender yellow papules with creamy-colored centers on extensor surfaces of the arms, hands and feet. Ophthalmoscopic examination showed creamy white retinal vessels with a faded pinkish white retinal back ground both in the periphery and posterior pole of the retina. Laboratory findings showed a grossly lipemic serum with markedly elevated serum levels of triglycerides 8869mg/dl cholesterol 498mg/dl. Her fasting blood glucose was 20.8mmol/l, 2 hours after breakfast was 50.5mmol/l and HbA1c was 14.6%. Eruptive xanthomas and lipaemia retinalis can occur in primary and secondary hyperlipoproteinemias, therefore a careful personal and family history as well as laboratory investigations is recommended in order to detect an underlying cause.

Prevalence of Metabolic Syndrome among Obese Children and Adolescents

Objectives: The Prevalence and magnitude of childhood obesity are increasing dramatically. The study was undertaken to see the prevalence of metabolic syndrome among children and adolescents with obesity, attending the Paediatric Endocrine OPD, BIRDEM. Methods: A cross sectional study was conducted from January 2006 to December 2008 among obese children and adolescents (6-18 years) attending Paediatric endocrine out patient department of BIRDEM. Children with any other endocrine disorder, dysmorphism/syndrome were excluded. Obesity was defined as BMIe”95th percentile for age and sex using CDC growth chart. Children underwent two-hour oral glucose tolerance test, anthropometric and blood pressure measurement. Fasting serum insulin and lipid profile were measured. Impaired glucose tolerance (IGT) was defined as fasting plasma glucose (FPG) <7 mmol/L and 2 hr post glucose load e”7.8 mmol/L to<11.1 mmol/L. Metabolic syndrome was identified if 3 or more of following criteria were met: BMI > 97th percentile for age and sex, high triglyceride (TGe”150 mg/dl), low high-density lipoprotein cholesterol (HDL cholesterol<40mg/dl), Systolic or diastolic blood pressure>95th percentile for age and sex, IGT. Results: A total of 161 children presented with obesity. Male to female ratio was 1.3:1. Mean age was 10.3±2.5 years. Metabolic syndrome was identified in 36.6% subjects (59 out of 161, twenty five male and 34 female). Higher BMI and hip circumference, systolic and diastolic hypertension, high TG, low HDL cholesterol and IGT were significantly associated with metabolic syndrome. Conclusions: The prevalence of metabolic syndrome is high among obese children and adolescents. Factors contributing towards obesity needs to be identified and strategies should be planned for prevention and management of this health problem. DOI: http://dx.doi.org/10.3329/birdem.v1i1.12382 Birdem Med J 2011; 1(1): 21-25

Prevalence of obesity among affluent school children in Dhaka

A cross sectional study was conducted in September 2006 in one of the private schools in Dhaka, Bangladesh to see the prevalence of obesity among affluent school children and adolescents. Informed consent was taken from school authority to take anthropometric measurement of all school children. Standing height was measured with a stadiometer and weight with a bathroom scale. Waist and hip circumference were measured with a measuring tape. The body mass index (BMI) was calculated using weight in kilogram/(height in meter)2 formula. Obesity was defined as BMI≥95th percentile for age and sex, over weight as BMI≥85th percentile for age and sex, normal weight as BMI between 5th and 84th percentile and underweight as BMI <5th percentile. Official centers for disease control (CDC) growth chart for boys and girls age 2-20 years was used. Children and adolescents were divided into group 1(3-5 years), Group 2(6-9years), group 3(10-13 years) and group 4(14-18 years). There were a total of 468 children and adolescents (male 266, female 202). In group 1 there were 110 children, in group 2 there were177 children, in group 3 and 4 there were 149 and 32 adolescents respectively. The prevalence of obesity was 17.9%, higher among males (19.9%), compared to females (15.3%). Obesity was highest (27.7%) in group 2, 14.5% in group 1, 10.7% in group 3 and 9.4% in group 4.

Prevalence of immunoglobulin E-mediated food allergy in 6-9-year-old urban schoolchildren in the eastern Black Sea region of Turkey

BACKGROUND

The prevalence of adverse reactions to food in childhood in Turkey is not known.

OBJECTIVE

We aimed to investigate the prevalence and characteristics of IgE-mediated food allergies (FAs) in 6-9-year-old urban schoolchildren.

METHODS

This cross-sectional study recruited 3500 of the randomly selected 6-9-year-old urban schoolchildren from the eastern Black Sea region of Turkey during 2006. Following a self-administered questionnaire completed by the parents and the child, consenting children were invited for skin prick tests (SPTs) and oral food challenges. Children with suspected IgE-mediated FA were skin prick tested with a predefined panel of food allergens (milk, hen's egg, soy, wheat, peanut, fish, and hazelnut), aeroallergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat, dog, Alternaria, grass pollen mix, weed pollen mix, and tree pollen mix), and food allergens reported in the questionnaire. All children with a positive SPT to any food were invited for a double-blind, placebo-controlled food challenge (DBPCFC). The prevalence of IgE-mediated FA was established using DBPCFCs.

RESULTS

The response rate to the questionnaire was 78.2% (2739/3500). The estimated prevalence of parental-reported IgE-mediated FA was 5.7% (156/2739) [95% confidence interval (CI), 4.83-6.57%]. The rate of sensitization to the food allergens was 33.1% (48/145) in the parental-reported group. The confirmed prevalence of IgE-mediated FA by means of DBPCFC in 6-9-year-old urban schoolchildren living in the eastern Black Sea region of Turkey was 0.80% (22/2739) (95% CI, 0.47-1.13%). The most common allergenic foods were beef (31.8%), cow's milk (18.1%), cocoa (18.1%), hen's egg (13.6%), and kiwi (13.6%).

CONCLUSIONS

The rate of reported IgE-mediated FA was significantly higher than clinically confirmed FA by means of DBPCFC (odds ratio, 7.46; 95% CI, 4.67-12.01; P<0.0001). The order of allergenic foods was different and somewhat unique to the eastern Black Sea region of Turkey when compared with western countries.

Impact of the Expanded Program of Immunization against hepatitis B infection in school children in Malaysia

The implementation of the Expanded Program of Immunization (EPI) in 1989 has dramatic impact on hepatitis B virus (HBV) infection in school children in Malaysia. A cross-sectional seroprevalence study of HBV infection in 190,077 school children aged 7-12 years from 1997 to 2003 showed a steady decline of HBV surface antigen (HBsAg) prevalence rate from 2.5% for children born in 1985 to 0.4% among school children born in 1996. The overall prevalence of HBsAg was 0.6%, 0.7% in males and 0.6% in females. Over 92.7% of school children had been vaccinated with HBV vaccine, in which 93.7% were vaccinated under the EPI and 6.3% on voluntary basis. The school children vaccinated under EPI had a 0.4% HBsAg carrier rate, which was significantly lower than school children vaccinated on a voluntary basis (HBsAg carrier rate 1.3%) and non-vaccinated school children (HBsAg carrier rate 2.7%), suggesting that HBV vaccination of infants was the most effective measure in preventing vertical transmission of HBV in the hyperendemic region.

Evaluation of three commercial rapid tests for detecting antibodies to human immunodeficiency virus

Determine HIV-1/2, Chembio HIV-1/2 STAT-PAK and PenTest are simple/rapid tests for the detection of antibodies to HIV-1 and HIV-2 in human whole blood, serum and plasma samples. The assay is one step and the result is read visually within 15 minutes. Using 92 known HIV-1 reactive sera and 108 known HIV-1 negative sera, the 3 HIV tests correctly identified all the known HIV-1 reactive and negative samples. The results indicated that Determine HIV-1/2, Chembio HIV-1/2 STAT-PAK and PenTest HIV are as sensitive and specific (100% concordance) as Microparticle Enzyme Immunoassay. The data indicated that these 3 HIV tests are effective testing systems for diagnosis of HIV infection in a situation when the conventional Enzyme Immunoassay is not suitable.

The effect of loratadine in exercise-induced asthma

AIMS

To assess the effect of loratadine in exercise induced asthma.

METHODS

Randomised, double blind, placebo controlled study of 10 mg oral loratadine, once daily for three days in 11 children. At the end of the treatment period FEV(1) was measured, and patients were exercised on a treadmill. FEV(1) measurements were repeated at intervals after exercise.

RESULTS

Loratadine significantly reduced the decrease in FEV(1) after exercise at two, five, 10, 15, and 30 minutes, compared with placebo (p < 0.05). However, the mean decrease in FEV(1) at five minutes was more than 15% of baseline in the loratadine group.

CONCLUSIONS

Loratadine reduces, but does not prevent, exercise induced asthma in children.

Morgagni hernia: an unexpected cause of respiratory complaints and a chest mass

Morgagni hernia (MH) is the least common type of congenital diaphragmatic hernias. Although its course is often asymptomatic, it may be associated with various respiratory and gastrointestinal symptoms. We describe 7 children with MH during a 5-year period in three pediatric centers in Turkey. All children had acute or chronic respiratory symptoms; cough was the most frequent. The diagnosis was made by posterior-anterior (PA) and lateral chest X-rays. The PA chest X-rays showed a homogenous mass in 2 and a gas-filled cystic image in 3 children in the right cardiophrenic angle. A retrocardiac homogeneous density in one child, and bilateral consolidation in lower lung areas in another child were also seen. All lateral chest X-rays showed gas-filled bowel loops above the diaphragm. The diagnosis was confirmed by barium-contrast radiograph. Four patients had five additional anomalies, i.e., ventricular septal defect, right inguinal hernia, congenital hip dislocation, pectus carinatum, and obstruction of the uretero-pelvic junction. All of the hernias were repaired by an abdominal approach. There were no complications or recurrences during follow-up. In conclusion, MH should be considered in the differential diagnosis of cases of long-standing respiratory symptoms and/or when an unexplained radiological image, especially on the right cardiophrenic area, is present.

The effect of indomethacin on hepatitis B virus replication in chronic healthy carriers

BACKGROUND

A chronic HBsAg carrier state, a major cause of viral spread in a community, is one of the consequences of hepatitis B virus (HBV) infection. Although successful immunization programs have been initiated to eliminate the virus, there is still a large number of people with HBV infection worldwide. This study was designed to investigate the effect of indomethacin treatment on HBV markers in humans, in comparison with a control group.

METHODS

In total, 65 chronic 'healthy' HBV carriers were involved in the study. Patients were divided randomly into two groups. Group I (n = 42) received oral indomethacin 75 mg daily for 6 months. Group II (n = 23) acted as control. Patients in both groups were followed up for 6 months, during which laboratory tests, including viral parameters, were performed periodically. Liver biopsy was done in 17 patients (11/42 of the indomethacin group and 6/23 of the control group).

RESULTS

All liver biopsies showed grade 0-2 and stage 0-1 HBV in both groups (P > 0.05). HBsAg positivity did not change in any patient in either group. Five patients who had positive HBeAg in group I became negative 4 months later, while patients in group II continued to be positive at 6 months (P < 0.001). Similarly, all patients receiving indomethacin exhibited a total anti-HBeAg immunoglobulin response at 6 months, while the control group remained the same during this period (P < 0.05). HBV DNA, as detected by polymerase chain reaction in 20/22 (91%), was negative in group I at the end of 6 months. No change was observed in group II (P = 0.007).

CONCLUSIONS

Although no biochemical analyses were performed on prostaglandins in the present study, the results suggest that the prostaglandin pathway may be involved in the pathogenesis of the immune response against HBV, and that the suppression of viral replication is achieved as indicated by the disappearance of HBeAg and HBV DNA in healthy chronic HBV carriers.

Cola drinks consumption and oesophagitis

For oesophageal epithelial changes to develop from gastro-oesophageal reflux disease (GORD), the character of the refluxate must be acid enough to cause injury. Experimentally, copious perfusion of the oesophagus with weak acid is quite harmless. However, hydrochloric acid alone with a pH below 3.0 may cause oesophageal injury. Cola drinks are strongly acidic (pH 2.5). This study analyses the influence of and possible interaction between cola consumption and oesophagitis. Twenty rats were divided into two groups of 10. The animals received saline (pH 7.0) or cola (pH 2.6) per OS with 24 h free access to these solutions. After the experiment the oesophagus was dissected. The mucosa was macroscopically and histopathologically examined, and flow cytometric analysis was used to look for proliferative activity. The histopathological analysis showed that there is no difference between saline and cola. But the findings of cell cycle analysis showed that the effects of cola and saline in inducing oesophageal mucosal damage are different. In the cola group the values were G0/G1, 7.33 +/- 2.88; S, 29.88 +/- 2.88; G2/M, 0.10 +/- 0.01; PI (proliferative-regenerative index), 29.76 +/- 2.88. The rat cell population g0/g1 phases were found to be low (p < 0.01), and the cell population S and PI phases were found to be significantly elevated compared with the control group (p < 0.01). (G0/G1, 79.30 +/- 5.97; S, 16.06 +/- 8.27; G2/M, 4.66 +/- 4.03; PI, 20.03 +/- 6.01). These results were reflected in the proliferative index, which is used as a measure of the regeneration index. The data show that cola has proliferative and regenerative effects on the oesophageal mucosa, and it is possible that its regenerative effect is caused as a result of an irritant effect.

Candida biotypes isolated from clinical specimens in Malaysia

The distribution of Candida species was examined using 1114 yeasts isolated from various clinical specimens. The isolates were identified by germ tube test, hyphal/pseudohyphae and chlamydoconidia production and carbohydrate assimilation test using ten carbohydrates (glucose, sucrose, trehalose, cellobiose, arabinose, galactose, mannitol, raffinose, lactose and maltose). Among the 1114 isolates studied, 9 species of Candida were identified and the relative frequency of isolation was C. albicans (44.2%), C. parapsilosis (26.0%), C. tropicalis (17.7%), C. glabrata (9.6%), C. krusei (1.2%), C. rugosa (0.6%), C. guilliermondii (0.2%), C. lusitaniae (0.08%) and C. kefyr (0.08%). Non-C. albicans was the most common Candida species isolated from blood, respiratory system, urine and skin. The isolate from vaginal swabs was predominantly C. albicans. 82.2% of C. glabrata and 64.2% of C. krusei isolated in this study were from vaginal swabs.

Evaluation of a rapid test for the detection of antibodies to human immunodeficiency virus type 1 and 2

Hema-Strip HIV-1/2 is a one-step rapid test for the detection of anti-HIV-1/2 antibodies in whole blood. The test requires no expensive equipment and the results are available within 10-15 min. Using 72 known HIV-1 positive samples and 780 high-risk prisoners, the sensitivity and specificity of Hema-Strip HIV-1/2 was found to be comparable to microparticle enzyme immunoassay (MEIA). The data also indicated that Hema-Strip HIV-1/2 is an effective alternate testing system to conventional ELISA where the use of ELISA is not suitable and the result of the HIV testing is needed urgently.

Evaluation of a rapid test for the detection of antibodies to human immunodeficiency virus type 1 and 2

Hema•Strip HIV-1/2 is a one-step rapid test for the detection of anti-HIV-1/2 antibodies in whole blood. The test requires no expensive equipment and the results are available within 10–15 min. Using 72 known HIV-1 positive samples and 780 high-risk prisoners, the sensitivity and specificity of Hema•Strip HIV-1/2 was found to be comparable to microparticle enzyme immunoassay (MEIA). The data also indicated that Hema•Strip HIV-1/2 is an effective alternate testing system to conventional ELISA where the use of ELISA is not suitable and the result of the HIV testing is needed urgently.

The inhibiting effect of cola on gastric mucosal cell cycle proliferation in humans

BACKGROUND

Acidic beverages may be involved in regulating the cell proliferation of the gastric mucosa. We therefore analyzed the interaction of Coca-Cola consumption and gastric mucosal proliferation by means of flow cytometry.

METHODS

Sixteen healthy students agreed to participate in this study. All volunteers underwent an oesophagogastroduodenoscopy after a 12-h overnight fast. Endoscopic changes in the gastric mucosa were determined quantitatively. One day later, after a 12-h overnight fast, all volunteers received standard Coca-Cola (200 ml, pH 2.6, 4 degrees C). One hour later all volunteers again underwent oesophagogastroduodenoscopy, to measure gastric mucosal damage. During both the first and the second endoscopy at least four biopsy specimens were taken from the antrum for flow cytometric analysis.

RESULTS

The endoscopic analysis showed that there was no difference before and after Coca-Cola consumption. However, the flow cytometric analysis showed that Coca-Cola inhibited the proliferation index and the S phase. Before Coca-Cola consumption G0/G1: 60 (57-62), G2/M: 0.6 (0.2-1), S: 40 (37-42), and PI: 0.40 (0.38-0.43) and after Coca-Cola consumption G0/G1: 70 (60-73), G2/M: 1.9 (1.2-2.5), S: 28 (26-32), and PI: 0.30 (0.27-0.34) the cell population G0/G1 and G2/M phases were significantly increased (P < 0.0001, 0.0003), and the cell population S and PI phases were significantly low compared with the pre-consumption data (P < 0.0002, 0.0001).

CONCLUSION

The cell cycle analysis reflects that Coca-Cola inhibits a crucial event in the cell cycle occurring at the G1/S border.

Short-term effects of budesonide, nedocromil sodium and salmeterol on bronchial hyperresponsiveness in childhood asthma

BACKGROUND

The effects of budesonide, nedocromil sodium and salmeterol on bronchial hyperresponsiveness were determined over a period of 3 weeks.

METHODS

Forty-three asymptomatic children (22 male, 21 female, aged 7-17 years) with mild-to-moderate asthma were evaluated. The study was placebo-controlled and double-blind. At the beginning the forced expiratory volume in 1 second (FEV1) was measured and a methacholine challenge was performed to determine PC20 (provocative concentration of inhaled methacholine required to reduce FEV1 by 20%). The patients in group I (n = 12), group II (n = 10), group III (n = 11), and group IV (n = 10) inhaled 200 micrograms of budesonide, 2 mg of nedocromil sodium, 25 micrograms of salmeterol and a placebo, respectively, twice a day over the period of 3 weeks. Then the methacholine PC20 values of all patients were measured again and the results were compared statistically with their previous values.

RESULTS

The statistical data revealed that the methacholine doses in PC20 before and after treatment were different in group I (P < 0.01). However, these differences were not statistically significant in the other groups (P > 0.05).

CONCLUSIONS

The short term usage of budesonide decreases bronchial hyperresponsiveness, but nedocromil sodium and salmeterol in the given dises do not affect bronchial hyperresponsiveness.

Acute bronchodilatory effect of salmeterol on methacholine-induced bronchoconstriction in childhood asthma

A review of the literature highlights the need for research, particularly on the acute bronchodilatory effect of salmeterol on bronchoconstriction in the pediatric age group. The present study attempted to evaluate the acute bronchodilatory effect of salmeterol on methacholine-induced bronchoconstriction in childhood asthma and to compare it with the effect of salbutamol. Forty-four asymptomatic children with mild-to-moderate asthma (23 boys and 21 girls; aged 7-17 years) were studied. At the beginning, the baseline forced expiratory volume in 1 s (FEV1) was measured, and the methacholine challenge was performed by doubling the dose to determine PC20 (provocative concentration of inhaled methacholine required to reduce FEV1 by 20%). At the same time, the transcutaneous arterial oxygen saturation (SaO2) was also measured. Each subject inhaled a single dose of 25 micrograms salmeterol (n: 23, group I) or 100 micrograms salbutamol (n: 21, group II) following the SaO2 measurement. The same measurements (FEV1, SaO2) were repeated 5 and 20 min after the inhalation. After inhalation of salmeterol or salbutamol, the differences between the values of FEV1 and SaO2 after 5 and 20 min were insignificant in both group I and group II (P > 0.05), although there was a significant improvement in both FEV1 and SaO2 after 5 and 20 min (P < 0.005). From these findings it was concluded that salmeterol can be considered as effective as salbutamol on methacholine-induced bronchoconstriction.

Portal and splanchnic haemodynamics in patients with advanced post-hepatitic cirrhosis and in healthy adults. Assessment with duplex Doppler ultrasound

PURPOSE

To assess portal and splanchnic haemodynamics, and splanchnic vascular resistance in patients with advanced post-hepatitic cirrhosis and in healthy volunteers, by means of duplex Doppler ultrasound (US).

MATERIAL AND METHODS

The duplex Doppler US examination was performed in 16 patients with cirrhosis and in 24 healthy volunteers. We investigated vessel diameters, mean flow velocities, and mean blood flows in the portal vein, the superior mesenteric artery (SMA), and the splenic artery (SA), and measured the resistive index values of SMA and SA.

RESULTS

The mean portal venous blood flow in patients with cirrhosis (829 +/- 264 ml/min) was not statistically different from those in the volunteers (734 +/- 194 ml/min). The ratio of the SMA and SA blood flows (621 ml/min) to the portal venous blood flow (734 ml/min) was 0.85 in the control subjects. The mean portal venous blood flow (1261 ml/min) and the portal venous velocity (14.6 cm/s) were higher in the patients with recanalized para-umbilical veins than in the volunteers and in the patients without recanalized para-umbilical veins. The SMA and SA blood flows were significantly increased in patients with cirrhosis compared with volunteers. Splanchnic inflow (the sum of the SMA and SA blood flows) was higher than the portal blood flow in patients with cirrhosis except in the subjects with recanalized para-umbilical veins. SMA and SA resistive index values were significantly higher in these patients than in the volunteers.

CONCLUSION

Splanchnic blood flow and splanchnic vascular impedance increased significantly in patients with advanced post-hepatitic cirrhosis. Splanchnic inflow must not exceed portal venous blood flow in patients with recanalized para-umbilical veins. Portal vein velocity and portal venous blood flow measurements alone are not useful parameters for discriminating patients with cirrhosis from healthy subjects.

Empyema in children

Empyemas develop following bacterial pneumonias, thoracic trauma and surgery which are still among the common diseases, causing illness and death throughout the developing world. With the advent of potent antibiotics the mortality of empyema has been drastically reduced. In this study 52 patients (29 boys and 23 girls) with thoracic empyema were evaluated retrospectively. In this series the causes of empyema were postpneumonic in 50 patients, esophageal anastomotic leak in one patient, and thoracic trauma in one patient. The diagnosis was suspected clinically and by the finding of a pleural effusion on chest roentgenogram. Definitive diagnosis was confirmed by pleural aspiration which pus was obtained. Responsible organisms included; Staphylococcus aureus, Streptococcus pneumonia, Haemophilus influenza, pseudomonas, and Klebsiella. The most common is Staphylococcus aureus. The patients were treated in various ways; 14 patients were treated with antibiotics and thoracentesis, 38 patients were treated with a closed tube thoracostomy. Eight of 38 patients had the chest tube converted to an open empyema tubes for long term management. Fourteen of 38 patients developed abcess formation. Nine of 14 patients were treated with computed tomography guided catheter placement, five patients encountered thoracotomy and decortication. In this article, appropriate treatment and result of long-term follow-up of empyema were evaluated.

The calpain cascade. Mu-calpain activates m-calpain

m-Calpain, which usually requires near-millimolar Ca2+ for activation, undergoes autolysis at 25 microM Ca2+ in the presence of mu-calpain. m-Calpain in itself exhibits no sign of autolysis around this Ca2+ concentration. Half-maximal rate of the reaction occurs at 30 microM Ca2+, showing that it is mu-calpain that catalyzes the limited proteolysis of m-calpain in an intermolecular reaction ("heterolysis"). This heterolytic step is accompanied by the activation of m-calpain: mu- and m-calpain preincubated together at 25 microM Ca2+ show significantly higher activity than the sum of activities of mu- and m-calpains preincubated separately. m-Calpain is sensitized to Ca2+ by mu-calpain-mediated activation: the half-maximal value of 160 microM for activation is lowered to 64 microM, which is similar to the shift found in m-calpain autoactivation. We suggest that these in vitro observations are relevant in vivo and the calpain cascade may play an important role in coordinating the functioning of calpains in living cells.

Autolysis parallels activation of mu-calpain

The kinetics of autolysis and activation of mu-calpain were measured with microtubule-associated protein 2 (MAP2) as a very sensitive substrate. The initial rate of MAP2 hydrolysis was found to be a linear function of the autolysed 76 kDa form of mu-calpain large subunit at both 10 and 300 microM Ca2+, and both straight lines intersected the origin. This finding supports the view that native mu-calpain is an inactive proenzyme and that activation is accompanied by autolysis. The first-order rate constant of autolysis, K1(aut), was determined at different Ca2+ concentrations: the half-maximal value was at pCa2+ = 3.7 (197 microM Ca2+), whereas the maximal value was 1.52 s-1, at 30 degrees C. The Ca(2+)-induced activation process was then monitored by using our novel, continuous fluorimetric assay with labelled MAP2 as substrate. The first-order rate constant of activation, k1(act), was derived as the reciprocal of the lag phase ('transit time') at the initial part of the progress curve: half-maximum was at pCa2+ = 3.8 (158 microM Ca2+) and the maximum value was 2.15 s-1. The good agreement between the kinetic parameters of mu-calpain autolysis and activation is remarkable. We claim that this is the first kinetically correct determination of the rate constant of autolysis of mu-calpain. Pre-activated mu-calpain has a Ca2+ requirement that is almost three orders of magnitude smaller [half-maximal activation at pCa2+ = 6.22 (0.6 microM Ca2+)]. We cannot exclude the possibility that the activation process involves other mechanistic steps, e.g. the rapid dissociation of the mu-calpain heterodimer, but we state that in our conditions in vitro autolysis and activation run in close parallel.

Mutual protection of microtubule-associated protein 2 (MAP2) and cyclic AMP-dependent protein kinase II against mu-calpain

Phosphorylation by adenosine-3',5'-cyclic monophosphate (cAMP)-dependent protein kinase (PKA), but not by Ca(++)-calmodulin-dependent protein kinase II (CaMK II), was shown earlier to protect microtubule-associated protein 2 (MAP2) from cleavage by m-calpain (Johnson and Foley: J Neurosci Res 34: 642-647, 1993). We reinvestigated this phenomenon with the physiologically more relevant mu-calpain and found a qualitatively similar but quantitatively different picture. We further demonstrate that 1) protection is biphasically dependent on the degree of phosphorylation; 2) Ca(++)-phospholipid-dependent protein kinase (PKC) has about the same effect as PKA; 3) the effects of kinases A and C are not additive; and 4) stripping of native MAP2 from its phosphate content (17.8 +/- 2.3 mol/mol) enhances calpainolysis 3.6-fold. A reciprocal effect between kinase A and MAP2 was found: the RII, but not the RI, regulatory subunit of kinase A, which was shown to bind specifically to MAP2, is protected by MAP2 from mu-calpain attack. It is suggested that the specific anchoring of kinase A-II on MAP2 may serve not only kinase targeting in the dendrites, but also protection from calpainolytic degradation.

Diagnostic value of the nasal provocation test with Dermatophagoides pteronyssinus in childhood asthma

We aimed to determine whether the nasal provocation test (NPT) with allergen could be used as a diagnostic test in asthmatic children with or without allergic rhinitis, and whether it had any effects on pulmonary function tests and arterial oxygen saturation (SaO2) values. Therefore, 25 asthmatic outpatients sensitive to Dermatophagoides pteronyssinus (Dp), aged 6-17 years, 12 having allergic rhinitis, and 10 nonatopic children as a control group were challenged intranasally with solution containing Dp extract by administration of a total dose of 800-1000 AU to both nasal cavities. Before the test and 10 min and 20 min after the administration of the allergen intranasally, the nasal expiratory peak flow (NEPF), pulmonary function tests, and SaO2 were measured. In the NPT, a decrease of 20% or more in NEPF and occurrence of nasal symptoms were considered to be positive. NPT was positive in all the asthmatic patients with or without allergic rhinitis, while all the children in the control group had a negative test. Compared to values prior to the test, values of FEV1 (forced expiratory volume in 1 s) and SaO2 showed no statistically significant decrease, and no clinically significant asthmatic reaction was observed in any of the groups. Our study suggests that in asthmatic children with or without allergic rhinitis, the NPT with allergen is a simple, safe, and useful diagnostic test.

An ultrasensitive, continuous fluorometric assay for calpain activity

A rapid, continuous assay for calcium-activated neutral protease activity is described. This assay is based on monitoring the elevation in fluorescence intensity that occurs upon calpainolytic digestion of dichlorotriazinylamino-fluorescein-labeled microtubule-associated protein 2. Tedious separation of peptide products from the protein substrate in this rapid assay is unnecessary, which thus offers two remarkable advantages over conventional caseinolytic assay procedures: (i) it raises sensitivity of detection by about three orders of magnitude, allowing the quantitative determination of calpain in the high picogram range in 10 min; and (ii) it permits a continuous detection of activity, which may prove invaluable in enzyme-mechanism studies that require pre-steady-state measurements. Other features and advantages of the assay, along with its limitations, are discussed in detail.

The value of CSF adenosine deaminase levels in the differential diagnosis of childhood meningitis

In this study, adenosine deaminase (ADA) levels of serum and cerebrospinal fluid (CSF) in a total 28 children (13 with bacterial meningitis, 5 with mumps meningoencephalitis and 10 with febrile convulsions) were determined. The comparisons between the serum values were insignificant (p greater than 0.05) but the CSF levels of the children with bacterial meningitis were higher than in the others (p less than 0.05). These findings suggest that serum ADA levels are not important in the diagnosis and differential diagnosis of these diseases. However, ADA levels of CSF may be useful in differentiating between bacterial and viral meningitis.

Consanguineous marriages in the province of Trabzon, Turkey

This study involved 999 married women, aged between 15 and 49, at the twelve health centres in the province of Trabzon in order to determine the ratio of consanguineous marriages, the factors affecting this situation, the ratios of abortion and the mortality of children in the first year. This ratio of consanguineous marriages was found 20 percent. The education levels of the great majority of these were low. The average age was 18. These were most frequently between children of paternal aunts and maternal uncles (39%) and these marriages, the ratio of abortion and children mortality were higher than others (P less than 0.05). Furthermore, it has been established that the kind of marriage has considerably decreased in Trabzon lately, but we believe that this reduction will be higher in the future since the education levels rapidly increase.

Therapy of regional lymphadenitis following BCG vaccination

In this study we presented 92 cases with regional lymphadenitis (over 1 cm in diameter) which was caused by BCG vaccination generally performed a few days after birth. The patients were divided into four therapy groups. In group I, the lymphadenitis in 26 cases was excised totally by a surgical operation and they improved in a median period of four weeks (average: 4.4). No therapy was applied in 33 patients constituting group II and their periods of improvement were 28 weeks (average: 29.1). Sixteen cases in group III were given isoniazid (INH) 10 mg/kg for six months in addition to total surgical excision and their healing period was 4.5 weeks (average: 4). Seventeen cases in group IV were administered only INH for six months and the median improvement period was found to be 27 weeks (average: 28.2). The statistical differences in terms of the improvement periods between groups I and III, and groups II and IV were found to be insignificant (p greater than 0.05) but these differences were significant between groups I and II, groups I and IV, groups II and III, and groups III and IV (p less than 0.05). These results show that spontaneous healing is possible. Total excision is the best therapy for BCG lymphadenitis in suppurative forms and INH has no effect in shortening the therapy period.

Pulmonary Hydatid Cysts and Tuberculosis in a Child – A Case Report

A 7 years old male child presented with history of cough, fever, haemoptysis and chest pain for 2 years. On examination he was moderately pale and wasted. Respiratory system examination revealed features of consolidation in both lungs. His provisional diagnosis was pulmonary tuberculosis. TC was 1500/cumm ESR- 70mm in first hour, MT was negative and sputum for AFB was also negative. Radiological finding of chest revealed two large well defined dense opacities in both mid and lower zones of both lungs and there was no calcification or air fluid level. CT scan of chest showed large irregular enhancing mass lesion having air fluid level in right lower zone, well defined cystic lesions in both lungs, no calcification was seen. On the basis of xray and CT scan report we reviewed our diagnosis as pulmonary hydatid disease. Tablet albendazole was started preoperatively. The cyst was removed surgically and specimen was sent for histopathology. Report showed hydatid cyst and pulmonary tuberculosis. So confirmed diagnosis was Hydatid cyst and pulmonary tuberculosis.He was treated with antitubercular drugs and continuation of tablet Albendazole for 6 months. He was followed up regularly and was doing well. DOI: http://dx.doi.org/10.3329/jbcps.v29i2.7956 (J Bangladesh Coll Phys Surg 2011; 29: 102-105)