Complete conservation of an immunogenic gene (lcr1) in Leishmania infantum and Leishmania chagasi isolated from Iran, Spain and Brazil

BACKGROUND & OBJECTIVES

Kala-azar is the visceral and most severe form of leishmaniasis that leads to death if untreated. The causative agents of visceral leishmaniasis (VL) are members of Leishmania (L.) donovani complex which includes L. chagasi and L. infantum. Genome sequences have raised the question whether L. chagasi and L. infantum are synonymous or different. This question has important implications for clinical and epidemiological studies, evaluation of vaccines and drugs, and disease control. LCR1 is an immunogenic molecule discovered from L. chagasi with potential as a component of a Leishmania subunit vaccine. If this protein has potentials for being used in a vaccine or diagnostic testing, there should be little variability in this molecule between L. infantum isolates from diverse geographic regions. The aim of this study was to determine whether lcr1 of an Iranian strain of L. infantum was identical to lcr1 of both L. infantum strain from a different geographic region (Spain) and that of an L. chagasi isolate from Brazil.

METHODS

L. infantum isolated from an Iranian kala-azar patient was studied. Lcr1 from this isolate was PCR amplified, cloned, and studied by restriction digest analysis and sequencing.

RESULTS

The sequences of lcr1 of the Iranian L. infantum were completely identical at nucleotide level to lcr1 sequences of both the Spanish L. infantum and the Brazilian L. chagasi strains.

CONCLUSION

Complete conservation of the DNA sequence encoding for LCR1 molecule between geographically distinct Leishmania species adds credibility to the potential for LCR1 as a component of a subunit vaccine and diagnostic test for kala-azar.

Phylogenetic analysis in a recent controlled outbreak of Crimean-Congo haemorrhagic fever in the south of Iran, December 2008

Crimean-Congo haemorrhagic fever (CCHF) is a viral zoonotic disease with a high mortality rate in humans. The CCHF virus is transmitted to humans through the bite of Ixodid ticks or contact with blood or tissues of CCHF patients or infected livestock. In December 2008, a re-emerging outbreak of CCHF occurred in the southern part of Iran. Five people were hospitalised with sudden fever and haemorrhaging, and CCHF was confirmed by RT-PCR and serological assays. One of the cases had a fulminant course and died. Livestock was identified as the source of infection; all animals in the incriminated herd were serologically analysed and more than half of them were positive for CCHFV. We demonstrated that two routes of transmission played a role in this outbreak: contact with tissue and blood of infected livestock, and nosocomial transmission. Phylogenetic analyses helped to identify the origin of this transmission. This outbreak should be considered as a warning for the national CCHF surveillance system to avoid further outbreaks through robust prevention and control programmes.

Microbiological and SYBR green real-time PCR detection of major Fusarium head blight pathogens on wheat ears

Fusarium head blight (FHB) caused by several Fusarium species is one of the most serious diseases affecting wheat throughout the world. The efficiency of microbiological assays and real-time PCRto quantify major FHB pathogens in wheat ears after inoculation with F. graminearum, F. culmorum, F. avenaceum and F. poae undergreenhouse and field conditions were evaluated. The frequency of infected kernel, content of fungal biomass, disease severity and kernel weight were determined. To measure the fungal biomass an improved DNA extraction method and a SYBR Green real-time PCR were developed. The SYBR Green real-time PCR proved to be highly specific for individual detection of the species in a matrix including fungal and plant DNA. The effect of Fusarium infection on visible FHB severity, frequency of infected kernels and thousand-kernel mass (TKM) significantly depended on the Fusarium species/isolate. F. graminearum resulted in highest disease level, frequency of infected kernels, content of fungal biomass, and TKM reduction followed by F. culmorum, EF avenaceum and F. poae, respectively. The comparison of frequency and intensity of kernel colonization proved differences in aggressiveness and development of the fungi in the kernels. Only for F. graminearum, the most aggressive isolate, application of microbiological and real-time PCR assays gave similar results. For the other species, the intensity of kernel colonization was lower than expected from the frequency of infection.

Hard Ticks on Domestic Ruminants and their Seasonal Population Dynamics in Yazd Province, Iran

BACKGROUND

Ticks are the main vectors for transmission of different pathogens to human and animals. This survey was performed to find out distribution of ticks, which infested the domestic ruminants in Yazd Province, central Iran during year 2008-2009.

METHODS

A total number of 30 villages from both mountainous (20%) and plateau (80%) regions of the province were selected randomly. Ticks were colleted from the body of infested animals and transported to the laboratory of Medical Entomology, School of Public Health, Tehran University of Medical Sciences and then were identified to space level using valid identification key.

RESULTS

A total of 583 hard ticks were collected. The ticks were classified into three genera and 7 species including: Hyalomma dromedarii (55.92%), Hy. marginatum (13.20%), Hy. anatolicum (9.78%), Hy. detritum (4.98%), Hy. asiaticum (3.94%), Rhipicephalus sanguineus (11.84%), and Dermacentor marginatus (0.34%). The highest seasonal activities occurred in summer. The prevalence of the Ixodidae ticks was more evident in plateaus area in Yazd Province. Among the hosts including: cow, goat, sheep and camel, the ticks that collected from camel was more prevalent. The ratio of male was more than female ticks. Hyalomma. dromedarii was the predominant tick species and accounted for 55.92% of the ticks.

CONCLUSION

Some of the collected ticks may play an important role for transmission of vector borne disease to human; therefore, the results of this study will provide a clue for vectors of tick-borne diseases in the region for local authorities for implementation of disease control.

Platelet count and neonatal sepsis: a high prevalence of Enterobacter spp

INTRODUCTION

Sepsis is a common complication in the neonatal intensive care unit. It is most common in the smallest and most premature infants in whom the clinical presentation can be subtle and nonspecific. The objectives of the present study were to identify the most common organisms causing sepsis and their associations with thrombocytopenia.

METHODS

This is a retrospective case analysis of blood culture positive patients between March 2003 and July 2007 in a single centre. We enrolled 53 eligible neonates whose blood culture yielded positively for any organism. Blood for the culture was obtained from a peripheral vessel. The data was analysed for differences in platelet and neutrophil count in terms of the microorganisms causing sepsis using chi-square and Fisher's exact tests, analysis of variance and Kruskal-Wallis, as appropriate.

RESULTS

The most common organism in the blood culture was Enterobacter spp. with 21 cases (39.6 percent) and the least common was coagulase-positive Staphylococcus spp. The most common organisms in infants with normal weight and early onset sepsis were coagulase-positive Staphylococcus spp. (50 percent and 36.7 percent, respectively), while in other neonates with low birth weight, very low birth weight and late onset sepsis, the most common organism was Enterobacter spp. (40.9 percent, 71.4 percent and 47.8 percent, respectively). The patients with Enterobacter spp. sepsis had a higher incidence of thrombocytopenia. The mortality rate was 15.1 percent (8/53 cases), which was significantly higher among those with the Enterobacter spp. sepsis (five cases, p-value is 0.033).

CONCLUSION

Our study shows the changes in the pattern of late onset neonatal infections in the neonatal intensive care unit. Enterobacter spp. is the most common organism causing neonatal sepsis accompanying thrombocytopenia.

Discrete Fourier analysis of ultrasound RF time series for detection of prostate cancer

In this paper, we demonstrate that a set of six features extracted from the discrete Fourier transform of ultrasound Radio-Frequency (RF) time series can be used to detect prostate cancer with high sensitivity and specificity. Ultrasound RF time series refer to a series of echoes received from one spatial location of tissue while the imaging probe and the tissue are fixed in position. Our previous investigations have shown that at least one feature, fractal dimension, of these signals demonstrates strong correlation with the tissue microstructure. In the current paper, six new features that represent the frequency spectrum of the RF time series have been used, in conjunction with a neural network classification approach, to detect prostate cancer in regions of tissue as small as 0.03 cm2. Based on pathology results used as gold standard, we have acquired mean accuracy of 91%, mean sensitivity of 92% and mean specificity of 90% on seven human prostates.

Posttransplantation lymphoproliferative disorders in renal transplant recipients: report of over 20 years of experience

INTRODUCTION

Despite the benefits of immunosuppressive medications to improve graft function, they have several adverse effects, such as development of neoplasms in renal transplant recipients. Posttransplantation lymphoproliferative disorders (PTLDs) are not uncommon complications, so we conducted a study to evaluate the characteristics of affected patients.

METHODS

We enrolled 2117 kidney recipients from June 1984 to March 2004 in order to find pathological and clinical evidence of neoplasms. We collected and analyzed all data on PTLD patients.

RESULTS

Overall there were 46 recipients with different types of neoplasms, among which the most common types were diseases of the skin (24 cases, 52.2%), Kaposi's sarcoma (15 cases, 32.6%), and PTLD (14 cases, 30.4%). The mean (+/- SD) age of PTLD patients at the time of transplantation was 37.86 +/- 9.67 years and 42.8% were women. Median and mean (+/- SD) time interval to PTLD diagnosis were 38.5 and 50.35 +/- 41.7 months, respectively (range 1 to 146 months). Types of PTLD in these patients were kidney lymphoma (14.3%); gastrointestinal (14.3%); brain lymphoma; tonsils; palatine; Hodgkin's lymphoma, large cell lymphoma, and acute lymphoblastic lymphoma (each 7.1%), with 28.6% unspecified types. The 1-, 5-, and 10-year patient survival rates after transplantation were 71.4%, 51.4%, and 44.3%, respectively. Despite discontinuing immunosuppressive therapy in PTLD patients, five of six surviving had graft function up to a mean time of 105.4 +/- 57.6 months after transplantation.

CONCLUSION

Our findings showed that the prevalence of PTLD was 0.66%, which was less than reports from Western countries. The fact that there were surviving grafts for a considerable time despite discontinuing immunosuppressive therapy is of great importance.

Bone mineral density in Iranian adolescents and young adults with beta-thalassemia major

The authors investigated the prevalence of low bone mass in patients from Tehran, Iran, with beta-thalassemia major (n = 203), aged 10-20 years, and the potential risk factors for osteoporosis in this patient population. Prevalence of osteoporosis was 50.7% in lumbar spine, 10.8% in femur, and 7.9% in both regions with no significant difference between the two genders. The following factors were associated with low BMD: height for age and weight for age below 3rd percentile, delayed puberty or hypogonadism, age when Desferal (for iron chelation) was started, duration of Desferal therapy, and serum zinc. Low serum copper and 25(OH)D were not associated with low BMD.

Hyperlipidemia After Renal Transplantation and Its Relation to Graft and Patient Survival

INTRODUCTION

Hyperlipidemia is a multifactorial event that frequently develops following renal transplantation and may worsen the patient's prognosis. The aim of this study was to evaluate the incidence and concomitant factors for hyperlipidemia.

METHODS

We studied 687 renal transplant recipients from 1988 to 2004 using a cross-sectional design to determine the frequency of hypercholestrolemia and hypertriglyceridemia before and 1 month to 1 year after renal transplantation, to evaluate its relation to patient and graft prognosis in two medical centers in Iran. Cyclosporine was the constant part of immunosuppressive treatment in all study subjects.

RESULTS

One and 5-year graft survival times were 94.23% and 81.34%, respectively. The prevalence of hypercholestrolemia after transplantation was 59.9%. Mean (+/- 2 SE) serum cholesterol levels before and after transplantation were 161.15 +/- 3.81 and 213.83 +/- 4.53 mg/dL respectively (P=.000). Triglycerides levels, were 159.99 +/- 13.08 and 196.28 +/- 19.6 mg/dL respectively. There was no significant correlation between cyclosporine dose, graft and patient survivals, and severity of hyperlipidemia (determined by cholesterol and triglyceride levels).

CONCLUSIONS

Lipid metabolism abnormalities observed in this study were similar to other reports. There was no correlation with patient or graft survival. In addition, there may routes for development of hyperlipidemia other than adverse complications of immunosuppressive drugs.

Calcium and Phosphorus Metabolism Disturbances After Renal Transplantation

INTRODUCTION

Several studies have noted that, despite beneficial correction of abnormalities of mineral metabolism after successful renal transplantation, renal functional recovery is incomplete. Also, persistence of hyperparathyroidism and metabolic acidosis among patients with chronic impairment of graft function together with the use of loop diuretics and immunosuppressive drugs with adverse effects may alter mineral metabolism. We determined calcium and phosphorus levels in recipients.

METHODS

This cross-sectional study enrolled 398 recipients in 2 medical centers in Iran from 1988 to 2004 to evaluate serum calcium and phosphorus levels after 1 month in relation to graft and patient survivals. Cyclosporine was the constant part of the immunosuppressive treatment in all study subjects.

RESULTS

The median follow-up time was 8 months (range, 1-180 months). One and 10-year survival rates of patients were 97.9% and 91.1%. Mean (SD) serum calcium levels before and after transplantation were 8.79 (1.26) and 8.50 (1.39) mg/dL, respectively (P=.020). The mean (SD) phosphate levels before and after transplantation were 6.43 (2.42) and 3.64 (1.71) mg/dL, respectively (P=.000). There was no significant difference in survival considering changes in serum calcium and phosphorus levels. There was no correlation between serum calcium and phosphorus level changes among study patients.

CONCLUSIONS

Despite reports suggesting hypercalcemia as a posttransplantation finding, we did not observe this condition, but, consistent with other reports in this field, we observed a significant decrease in serum phosphorus levels showing correction of this mineral level.

Direct correlation functions of binary mixtures of hard Gaussian overlap molecules

We study the direct correlation function (DCF) of a classical fluid mixture of nonspherical molecules. The components of the mixture are two types of hard ellipsoidal molecules with different elongations, interacting through the hard Gaussian overlap (HGO) model. Two different approaches are used to calculate the DCFs of this fluid, and the results are compared. Here, the Pynn approximation [J. Chem. Phys. 60, 4579 (1974)] is extended to calculate the DCF of the binary mixtures of HGO molecules, then we use a formalism based on the weighted density functional theory introduced by Chamoux and Perera [J. Chem. Phys. 104, 1493 (1996)]. These results are fairly in agreement with each other. The pressure of this system is also calculated using the Fourier zero components of the DCF. The results are in agreement with the Monte Carlo molecular simulation.

Miners' exposure to radon and its decay products in some Iranian non-uranium underground mines

Measurements of radon, radon decay products and gamma exposure rate in 12 non-uranium underground mines have been carried out in order to estimate the occupational radiation exposure of miners. Continuous measurements of radon using pulse ionisation chambers and scintillation cell techniques were employed for these studies. Progenies of radon were collected on filter paper, and then a three-count procedure was used for the measurement. The equilibrium state between radon and its decay products has been determined. Concentrations of natural radionuclides ((226)Ra, (232)Th and (40)K) in ore and soil samples taken from various locations in each mine have been measured using a Canberra High Purity Germanium detector. Based on these measurements two ranges of dose were evident. Doses ranged from 0.1 to 1.52 mSv y(-1) for nine mines and from 10 to 31 mSv y(-1) for the other three mines. A separate grouping of the mines was recognised from radon concentrations, which varied from 2 Bq m(-3) to 10 kBq m(-3). In three of these mines, working level (WL) concentrations of the order of 36-1771 mWL were determined in different working areas. In all other mines, the concentrations were observed to be <45 mWL.

Density functional theory of liquid crystals and surface anchoring

This paper applies the density functional theory to confined liquid crystals comprising ellipsoidal shaped particles interacting through the hard Gaussian overlap (HGO) potential. The restricted orientation model proposed by Rickayzen [Mol. Phys. 95, 393 (1998)] is extended to study the surface anchoring. The excess free energy is calculated as a functional expansion of density around a reference homogeneous fluid. The pair direct correlation function (DCF) of a homogeneous HGO fluid is approximated, based on the Percus-Yevick DCF for hard spheres; the anisotropy is introduced by means of the closest approach parameter. The average number density and orientational order parameter profiles of a HGO fluid confined in between planar walls are obtained using a hard needle-wall potential to represent the particle-wall interactions. For short and long needle lengths, the homeotropic and planar anchoring are observed, respectively. For the bulk isotropic phase the calculated density and order parameter profiles are in agreement with the Monte Carlo simulation of Barmes and Cleaver [Phys. Rev. E 69, 61705 (2004)]. However, for the bulk nematic phase the theory gives the correct density profile between the walls. The correct order parameters are obtained close to the walls whereas for the region in the middle of the walls, the agreement is less satisfactory.

Density profile and order parameter of a hard ellipsoidal fluid confined to a slit

The density profile and order parameter of a fluid of hard axially symmetric ellipsoids confined in between two parallel hard walls is obtained by using the density functional theory. The required input direct correlation function of the homogeneous fluid is calculated by the variational method introduced by Marko (1989 Phys. Rev. 39 2050) and the modified closest approach method proposed by Rickayzen (1998 Mol. Phys. 95 393). Here the restricted orientation model, ROM, is extended to study a fluid comprising molecules which can be aligned in more than six directions, making it more representative of a normal fluid. The density profiles, the average number density and order parameter are obtained for different values of density and elongations. The results are in agreement with the previous theory and available Monte Carlo simulation results.