Comparison of 16S rDNA-PCR amplification and culture of cerebrospinal fluid for diagnosis of bacterial meningitis

Early and accurate diagnosis of bacterial meningitis is of critical concern. Optimum and rapid laboratory facilities are not routinely available for detecting the etiologic agents of meningitis. The objective of this study was to compare polymerase chain reaction [PCR] assay with culture for detection of bacteria in central nervous system [CNS] samples from patients suspected to have meningitis. One-hundred CSF samples were obtained and divided into two parts. One part of samples was used for standard bacterial culture and gram staining. The remaining was used for DNA extraction. PCR assay was performed with universal primers for 16S rDNA gene of bacteria. Performance characteristics of the test were determined. The PCR method was able to detect bacteria in all 36 culture-positive and in 38 of 64 culture-negative cases showing sensitivity and specificity of 100% and 40.6% respectively. Positive predictive value was 48.6% and negative predictive value 100%, however, Kappa coefficient showed the correlation of the 2 methods to be at 0.33. There are advantages and disadvantages in performance characteristics of the conventional CSF culture and universal CSF 16S rDNA PCR. Therefore, it is recommended to use both methods in clinical practice, particularly in suspicious contaminated samples, with presumable presence of fastidious or slow growing bacteria because of antibiotic consumption

[Comparison of 16S rDNA-PCR amplification and culture of cerebrospinal fluid for diagnosis of bacterial meningitis]

Early and accurate diagnosis of bacterial meningitis is critical concern. Optimum and rapid laboratory facilities are not routinely available for detecting the etiologic agents of meningitis. The objective of this study was the comparison of polymerase chain reaction [PCR] assay with culture, for the detection of bacteria in CSF samples from patients suspected of meningitis in Hospitals of Qazvin. 100 CSF samples were obtained and divided in two parts. One part of samples was used for standard bacterial culture and gram staining. The remaining was used for DNA extraction. A PCR assay was performed with universal primers for 16S rDNA gene of bacteria. Performance characteristics of the test were determined. The PCR method was able to detect bacteria in 36 cultures [..] positive and in 38 of 64 cultures were negative cases, showing sensitivity, Specificity of 100% and 40.6% respectively. Positive predictive value [PPV] was 48.6% and its negative predictive value [NPV] was 100%, however, Kappa coefficient showed the correlation of 2 methods to be at 0.33. There are advantages and disadvantages in performance characteristics of the conventional CSF culture and universal CSF 16S rDNA PCR. Therefore, it is recommended to use both methods in clinical practices, particularly in suspicious contaminated samples, with presumable presence of fastidious or slow growing bacteria and antibiotic consumption

Survey of relationship between asthma and epilepsy

Asthma attacks can result in respiratory alkalosis and decreased level of Ionized calcium and cerebral Vasoconstriction. Different studies indicate that Alkalosis and decreased level of CO2 can increase convulsive activities and neuronal excitability. This condition may increase level of Dopamin and risk of convulsion. This study was conducted to survey the relationship between asthma and epilepsy. In an Analitical- cross sectional study 400 Asthmatic patients who were reffered to outpatient clinic of Tabriz university of Medical sciences from January 2004 to July 2006, were concurrently surveyed for Epilepsy too. The results analyzed with Z test for one proportion. Number of patients who had two disease of asthma and Epilepsy concurrently was 12 which 7 of them were male and 5 female respectively. Mean age of patients was 5 +/- 2/3 with confidence interval [Ci = 3/5 - 6/5] Comparison of Asthmatic patients who were epileptic with Normal population was significant [P=0/009] Considering epilepsy prevalence rate of%1 in normal population and%3 in asthmatic patients and risk of respiratory alkalosis in asthmatic it is slrongly recommended to have special attention to Asthma attacks, in epileptic too

Low magnesium concentration in erythrocytes of children with acute asthma

Magnesium [Mg] is the second most abundant intracellular cation and is involved in numerous physiological functions, including protein folding, intracellular signaling and enzyme catalysis. It has been shown that magnesium deficiency exacerbates pulmonary airways hyperreactivity. Several studies suggest that magnesium level has no effect on asthma but others had shown a contributory effect. Because of its intracellular abundance, the aim of this study was to determine if there was any difference in plasma and intracellular Mg concentrations of children with acute asthma compared to non asthmatic children. Twenty nine patients with acute asthma aged 2 to 11 years admitted to the emergency department of hospital and 37 non asthmatic children with the same age were included in our study. O.5 mL of heparinized whole blood samples of patients who were meeting inclusion criteria at the onset of admission with bronchoconstriction and before using any medication was drawn and it was immediately sent to the laboratory. Plasma and erthrocytes were separated and stored at -20C and later their Mg levels were quantified with atomic absorption spectrophotometry method. The average plasma and intracellular magnesium levels in patients were [0.79 +/- 0.098 mmol/L] and [1.17 +/- 0.27 mmol/ L] respectively. Results of 37 non asthmatic persons [plasma [0.85 +/- 0.1 mmol/L] and erythrocytes [1.33 +/- 0.21 mmol/ L]] showed that there was no significant difference between plasma Mg levels in two groups [p 0.06] but intracellular magnesium level was significantly lower [p 0.03] in patients group. These results indicate that intracellular Mg level may be a more accurate method to assess Mg level in patients with asthma. Hence, determination of Mg concentration in erythrocytes may be used in evaluation of asthma pathophysiology. There are recommendations for using intravenous Mg sulfate in acute asthma, and this study supports the rational for using it in emergency departments for acute severe asthma

study of malnutrition in Iranian patients with primary antibody deficiency

Nutrition is an important factor that influences immunity, and nutritional deficiencies can impair resistance to infections. Malnutrition is the most common cause of immunodeficiency worldwide. Trace elements such as zinc, selenium, iron, and copper can influence several components of immunity. Primary antibody deficiency disorders are a group of disorders characterized by an unusual susceptibility to infections and malnutrition. Impaired nutritional status has been reported in immunodeficient patients. The aim of this study was to determine anthropometric indices and trace elements status in these patients. Thirty-eight children [28 males, 10 females, aged 2-18 years] with primary antibody deficiency referring to Children's Medical Center of Tehran University of Medical Science were enrolled in this research. Primary immunodeficiency disorders consisting of CVID, XLA, IgA deficiency, IgG subclass deficiency, and hyper IgM were assessed. Anthropometric indices, comprised of height, weight that were measured and body mass index [BMI] was calculated. Height-for-age [HAZ], weight-for-height [WHZ] and weight-for-age [WAZ] were determined according to Z-score to study mild, moderate and severe malnutrition. Serum copper, zinc, selenium and iron levels were measured by an atomic absorption spectrometer. The most common disorders were CVID 52.5% and X-linked agammaglobulinaemia 27.5%. Based on BMI measurements 21.1% of patients had malnutrition. According to HAZ, 13.2%, 13.2% and 36.8% had severe, moderate and mild malnutrition, respectively. According to WAZ, 10.5%, 18.4% and 28.6% had severe, moderate and mild malnutrition, respectively. Regarding to WHZ, 14.3% and 28.6% had moderate and mild malnutrition, respectively. Low selenium levels and high copper levels were observed in 37.5% and 70.3%, respectively. Anthropometric data showed that the frequency of malnutrition in these patients was higher than the CDC standard. Low serum selenium levels and high serum copper levels were observed, suggesting further research is needed on these parameters. Most of the patients had serum zinc and iron levels within the normal range. It is recommeded that clinical immunologists and nutritionists should make a collective effort to provide these patients with standard or specialized diets so as to decrease the risk of infection