Post-autotomy regeneration of respiratory tree in sea cucumber Holothuria parva.

The respiratory trees present only in the class Holothuroidea and the rest of the echinoderms lack it. Only some holothurian species have the ability to regenerate their respiratory trees after autotomy. Therefore, respiratory trees could be considered as a suitable model to assess the regeneration mechanisms in animals. In the present study, the respiratory tree regeneration after posterior evisceration were examined in Holothuria parva during 75 days. Since autotomy reduces antioxidant defense in the organisms, in the present study alterations of antioxidant enzymes were also evaluated during the experiment. H. parva is the dominant intertidal species distributed in the north of the Persian Gulf. In the present study, H. parva ejected the left respiratory tree, the digestive tract and supportive mesenteries from the anus, about 1-2 min after potassium chloride injection. The closure of the opening at the posterior ends of the body was the first reaction to the injury. Seven days after evisceration, the small bud formed on the dorsal side of the cloaca which was covered with the coelomic epithelium of cloaca. The coelomic epithelium started to proliferate to undifferentiated cells on the apex of the buds. The primary respiratory tree consisted of the luminal cuboidal epithelium and thin connective tissue surrounded by the slender coelomic epithelium. This preliminary organ was observed at the apex of the buds, 13 days after evisceration. Gradually, myoepithelial cells arranged around a longitudinal axis and formed a circular muscle. The primitive branches of primary respiratory tree started to form 18 days after evisceration. Forty days after evisceration, the luminal epithelium of the respiratory tree had the same appearance as the intact luminal epithelium. The regenerated respiratory tree was histomorphologically very similar to an intact respiratory tree 56 days postevisceration, but unlike that, it was not yet wrapped around the intestine and was completely separate from it. Despite the development of the regenerating respiratory tree, no wrapping around the intestine was observed until the end of the experiment. According to the results, the activity of the catalase (CAT) and superoxide dismutase (SOD) in the muscle homogenate was significantly higher than the control 5 days after evisceration. The CAT and SOD levels gradually decreased in eviscerated animals. The lipid peroxidation level followed a decreasing trend in the eviscerated animals during the experiment. However, its value reduced to the control level at the end of the experiment.

Culture-negative endocarditis with neurologic presentations and dramatic response to heparin: a case report.

BACKGROUND: Blood culture-negative endocarditis (BCNE) is diagnosed in 2-7% of patients with infective endocarditis (IE) and recent antibiotic use is a known risk factor. Altered mental status may be a presenting symptom. Besides empiric antibiotics, intravenous anticoagulation using heparin may have a role in the management of such patients. CASE PRESENTATION: A 23-year-old male patient was referred to our center with fever, altered mental status and abnormal gait. Neurologic examination revealed Wernicke's aphasia. Cardiac auscultation revealed systolic murmur at the left sternal border. ECG (electrocardiogram) was unremarkable. Brain MRI showed multiple cerebellar lesions. Transthoracic echocardiography (TTE) demonstrated three large masses on the right ventricle (RV), tricuspid valve (TV), and anterior mitral valve (MV) leaflet. Blood cultures (three sets) were negative. Intravenous heparin therapy was administered. After 48 h, the second TTE demonstrated that one valvular lesion disappeared and the other two lesions showed a significant decrease in size. The patient's neurological symptoms resolved gradually. Further workup for collagen vascular disorders did not show any abnormality. CONCLUSION: BCNE should be considered in patients with fever and neurologic manifestations. TTE should be performed to detect valvular abnormalities. Intravenous heparin could be used in such patients when TTE demonstrate valvular vegetations.

Soil quality assessment using GIS-based chemometric approach and pollution indices: Nakhlak mining district, Central Iran.

This paper is a comprehensive assessment of the quality of soil in the Nakhlak mining district in Central Iran with special reference to potentially toxic metals. In this regard, an integrated approach involving geostatistical, correlation matrix, pollution indices, and chemical fractionation measurement is used to evaluate selected potentially toxic metals in soil samples. The fractionation of metals indicated a relatively high variability. Some metals (Mo, Ag, and Pb) showed important enrichment in the bioavailable fractions (i.e., exchangeable and carbonate), whereas the residual fraction mostly comprised Sb and Cr. The Cd, Zn, Co, Ni, Mo, Cu, and As were retained in Fe-Mn oxide and oxidizable fractions, suggesting that they may be released to the environment by changes in physicochemical conditions. The spatial variability patterns of 11 soil heavy metals (Ag, As, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, and Zn) were identified and mapped. The results demonstrated that Ag, As, Cd, Mo, Cu, Pb, Sb, and Zn pollution are associated with mineralized veins and mining operations in this area. Further environmental monitoring and remedial actions are required for management of soil heavy metals in the study area. The present study not only enhanced our knowledge regarding soil pollution in the study area but also introduced a better technique to analyze pollution indices by multivariate geostatistical methods.

Genotype and Phenotype of Echinococcus granulosus Derived from Wild Sheep (Ovis orientalis) in Iran.

The aim of the present study is to determine the characteristics of genotype and phenotype of Echinococcus granulosus derived from wild sheep and to compare them with the strains of E. granulosus sensu stricto (sheep-dog) and E. granulosus camel strain (camel-dog) in Iran. In Khojir National Park, near Tehran, Iran, a fertile hydatid cyst was recently found in the liver of a dead wild sheep (Ovis orientalis). The number of protoscolices (n=6,000) proved enough for an experimental infection in a dog. The characteristics of large and small hooks of metacestode were statistically determined as the sensu stricto strain but not the camel strain (P=0.5). To determine E. granulosus genotype, 20 adult worms of this type were collected from the infected dog. The second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA (rDNA) and cytochrome c oxidase 1 subunit (COX1) of the mitochondrial DNA were amplified from individual adult worm by PCR. Subsequently, the PCR product was sequenced by Sanger method. The lengths of ITS2 and COX1 sequences were 378 and 857 bp, respectively, for all the sequenced samples. The amplified DNA sequences from both ribosomal and mitochondrial genes were highly similar (99% and 98%, respectively) to that of the ovine strain in the GenBank database. The results of the present study indicate that the morpho-molecular features and characteristics of E. granulosus in the Iranian wild sheep are the same as those of the sheep-dog E. granulosus sensu stricto strain.

Simultaneous immunization of mice with Omp31 and TF provides protection against Brucella melitensis infection.

Brucella vaccines consisting of live attenuated Brucella strains are currently used in livestock, but safety concerns preclude their application in humans. Subunit vaccines have recently emerged as safe and efficacious alternatives in both humans and animals. In this study, subunit vaccines were developed that consisted of a recombinant outer membrane protein (rOmp31) and the trigger factor chaperone protein (rTF) of Brucella melitensis, either alone or in combination. BALB/c mice that were immunized with rOmp31+rTF showed comparable but slightly higher TF-specific IgG1 and IgG2a antibodies as compared to mice with rTF alone. Indeed, mice given this combination had titers of rOmp31-specific antibodies similar to those immunized with rOmp31 alone. In lymphocyte reactivation experiments, the splenocytes of immunized mice, whether given either of these antigens alone or as a cocktail, exhibited a strong antigen-specific recall proliferative response and expressed high amounts of IFN-γ, IL-12, IL-10 and IL-6. Both rTF and rTF+rOmp31 vaccinated mice exhibited significantly higher CD4 and CD8 levels compared to the PBS group. The combination of rOmp31 and rTF provided protection against B. melitensis infection comparable to that of vaccine strain Rev.1. In comparison to rTF alone, combination of rTF and rOmp31 caused only a slight increase in protection level. Although combination of rTF and rOmp31 caused a non-significant increase in IFN-γ induction, antibody level, proliferation index and CD4 and CD8 frequencies compared to rTF alone, its cumulative effects on aforesaid parameters may be viewed as a better efficacy.

Effect of Ketamine on Post-Tonsillectomy Sedation and Pain Relief.

INTRODUCTION: Tonsillectomy is the one of the most common types of surgery in children, and is often accompanied by post-operative pain and discomfort. Methods of pain control such as use of non-steroidal anti-inflammatory drugs (NSAIDs), narcotics, and local anesthetics have been used, but each have their own particular side effects. In this study we investigated the effect of ketamine on post-operative sedation and pain relief. MATERIALS AND METHODS: A total of 50 children aged between 5 and 12 years who were candidates for tonsillectomy were divided into two groups. The study group received ketamine-midazolam (ketamine 1 mg/kg, midazolam 0.1 mg/kg) and the control group received midazolam (0.1 mg/kg) in the pre-operative period. The same methods of anesthesia induction and maintenance were used in all patients. Pain score was assessed using the Wong-Baker Faces Pain Rating scale and sedation was evaluated using the Riker Sedation-Agitation scale at the time of extubation as well as 5, 10, 15, and 30 minutes and 1, 2, and 6 hours after surgery. RESULTS: The two groups were similar in terms of age, weight, gender and duration of surgery. Pain after 15 and 30 minutes and agitation after 10 and 15 minutes following extubation were lower in the study group (ketamine-midazolam). Mean consumption and time of first request for analgesia after surgery as well as incidence of post-operative vomiting were similar in the two groups. CONCLUSION: Adding ketamine to midazolam in pre-operative of tonsillectomy reduces agitation and post-operative pain in the first 30 minutes after surgery.

Immunization of mice with a novel recombinant molecular chaperon confers protection against Brucella melitensis infection.

Brucella spp. are zoonotic Gram-negative intracellular pathogens with the ability to survive and replicate in phagocytes. It has been shown that bacterial proteins expressed abundantly in this niche are stress-related proteins capable of triggering effective immune responses. BMEI1549 is a molecular chaperone designated DnaK that is expressed under stress conditions and helps to prevent formation of protein aggregates. In order to study the potential of DnaK as a prospective Brucella subunit vaccine, immunogenicity and protective efficacy of recombinant DnaK from Brucella melitensis was evaluated in BALB/c mice. The dnak gene was cloned, expressed in Escherichia coli, and the resulting recombinant protein used as subunit vaccine. DnaK-immunized mice showed a strong lymphocyte proliferative response to in vitro antigen stimulation. Although comparable levels of antigen-specific IgG2a and IgG1 were observed in immunized mice, high amounts of IFN-γ, IL-12 and IL-6, no detectable level of IL-4 and very low levels of IL-10 and IL-5 were produced by splenocytes of vaccinated mice suggesting induction of a Th1 dominant immune response by DnaK. Compared to control animals, mice vaccinated with DnaK exhibited a significant degree of protection against subsequent Brucella infection (p<0.001), albeit this protection was less than the protection conferred by Rev.1 (p<0.05). A further increase in protection was observed, when DnaK was combined with recombinant Omp31. Notably, this combination, as opposed to each component alone, induced statistically similar level of protection as induced by Rev.1 suggesting that DnaK could be viewed as a promising candidate for the development of a subunit vaccine against brucellosis.

Identification of a new immunogenic candidate conferring protection against Brucella melitensis infection in mice.

Identification of bacterial proteins that contribute to the replication and survival of the engulfed bacteria within phagolysosome is critical in the pathogenesis of intracellular bacteria. Heat shock proteins (HSPs) are molecular chaperones that prevent unwanted protein aggregation and protect the bacteria against cell stress. In order to study the potential of HspA for development of a Brucella subunit vaccine, immunogenicity and protective efficacy of recombinant HspA (rHspA) from Brucella melitensis was evaluated in BALB/c mice. The hspA gene was cloned in pDEST42 and the resulting recombinant protein was used as subunit vaccine. rHspA elicited mixed TH1/TH2 immune responses with higher titers of specific IgG1 than IgG2a. In lymphocyte transformation assay, splenocytes of immunized mice exhibited a strong recall proliferative response with high amounts of IFN-γ, IL-12, IL-10 and IL-6 and very low levels of IL-5 and IL-4 production. The protective effect of rHspA was evaluated by administering rHspA to mice that resulted in a significant reduction in bacterial load and high degree of protection against B. melitensis challenge compared to control mice (p<0.001). These results suggest that rHspA may be a useful candidate for the development of subunit vaccine against brucellosis.

Immune reactivity of Brucella melitensis-vaccinated rabbit serum with recombinant Omp31 and DnaK proteins.

BACKGROUND AND OBJECTIVES: Brucella melitensis infection is still a major health problem for human and cattle in developing countries and the Middle East. MATERIALS AND METHODS: In this study, in order to screen immunogenic candidate antigens for the development of a Brucella subunit vaccine, a cytoplasmic protein (DnaK) and an outer membrane protein (Omp31) of B. melitensis were cloned, expressed in E.coli BL21 and then purified using Ni-NTA agarose. Immunized serum was prepared from a rabbit inoculated with attenuated B. melitensis. RESULTS AND CONCLUSION: It was proved that immunized serum contains antibodies against recombinant Omp31 (rOmp31) and DnaK (rDnaK) by Western blot and ELISA assays. The results may suggest the importance of these proteins as subunit vaccines against B. melitensis as well as targets for immunotherapy.

Slime layer formation and the prevalence of mecA and aap genes in Staphylococcus epidermidis isolates.

INTRODUCTION: Staphylococcus epidermidis strains are frequently associated with catheter-related infection, acute bacteremia, and hospital-acquired infection. Some isolates produce an extracellular matrix called slime that may make them more resistant to antibiotics. The aim of this study was to determine antimicrobial resistance patterns, the prevalence of slime production, and the distribution of genes (mecA and aap, respectively) associated with these phenotypes in S. epidermidis nasal isolates from health-care personnel. METHODOLOGY: A descriptive cross-sectional study was performed on 163 nasal swabs from health-care staff (one swab per subject). S. epidermidis isolates were tested for slime production on congo red agar and antibiotic resistance. PCR-based screening for mecA and aap genes was performed upon the extracted DNA of S. epidermidis isolates. RESULTS: A total of 99 S. epidermidis strains were cultured from 58.9% of the study participants (n = 96). Of these strains, 34 (34.3%) isolates produced slime. A significant relation between slime production and resistance to penicillin 32(94%) , oxacillin 30(88%), tetracycline 20(59%), erythromycin 27(79%), and clindamycin 26(77%) was found. Respectively, 95.8% and 94.8% of all isolates were PCR-positive for mecA and aap, but only 59.8% of mecA+ strains were oxacillin-resistant and 37.3% of aap+ strains were slime producers. CONCLUSIONS: The surveillance of nasal colonization with slime-forming oxacillin-resistant S. epidermidis in health-care workers might be helpful in breaking the epidemiological chain of hospital-acquired infections.

The incidence of nosocomial toxigenic clostridium difficile associated diarrhea in Tehran tertiary medical centers.

Clostridium difficile is the most common cause of nosocomial diarrhea. It is usually a consequence of antibiotic treatment, But sporadic cases can occur. This study was aimed to determine the frequency of the nosocomial Clostridium difficile (C. difficile) associated diarrhea in Tehran University of Medical Sciences hospitals and study of antibacterial susceptibility of isolates. In this study a total of 942 stool samples from patients with nosocomial diarrhea that were hospitalized in Imam Khomeini hospital, Shariati hospital and Children clinical center were collected. The samples were cultured on a selective cycloserine cefoxitin fructose agar (CCFA) and incubated in anaerobic conditions, at 37°C for 5 days. Isolates were characterized to species level by conventional biochemical tests. Bacterial cytotoxicity was assayed on tissue culture (vero). Antimicrobial sensitivity of isolated toxigenic C. difficile were investigated by kirby Beuer method (disk diffusion). Our findings show that, of the total patients, 57 toxigenic C. difficile (6.1%) were isolated. Results of statistical analysis show significant differences between the rate of isolated toxigenic C. difficile and age group of patients (P<0.05). Among the wards of selected hospitals, in gastroenterology of Children clinical center, Toxigenic C. difficile was isolated from patients most frequently. The sensitivity of isolates to vancomycin, Chloramphenicol and ceftriaxone were higher than other antibiotics. Toxigenic C. difficile is a common hospital-acquired infection. The organism was found in 6.1% hospitalized patients. Further studies to evaluate the rate and role of toxigenic C. difficile in nosocomial diarrheal processes, ecological and pathogenic terms are suggested.

Intracorneal ring segment implantation for the management of keratoconus: safety and efficacy.

PURPOSE: To assess the safety and efficacy of intracorneal ring segment (Intacs, Addition Technology, Inc.) implantation in the management of keratoconus. SETTING: Department of Ophthalmology and Ophthalmic Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran. METHODS: This prospective case series comprised 30 keratoconic eyes (22 patients) with a clear central cornea that had Intacs implantation. All patients were contact-lens intolerant. The main outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, keratometry, and pachymetry. Patients were examined before Intacs implantation as well as 1 week and 1, 3, and 6 months postoperatively. RESULTS: The mean age of the 5 women and 17 men was 25.9 years +/- 5.29 (SD). The mean UCVA improved from 0.60 +/- 0.311 logMAR preoperatively to 0.29 +/- 0.20 logMAR 6 months postoperatively (P<.001) and the mean BSCVA, from 0.25 +/- 0.16 logMAR to 0.13 +/- 0.14 logMAR, respectively (P<.001). The mean spherical equivalent improved from -6.93 +/- 3.52 diopters (D) preoperatively to -3.23 +/- 2.81 D at 6 months and the mean refractive cylinder, from -4.65 +/- 1.85 D to -3.90 +/- 1.70 D, respectively. The mean keratometry decreased from 49.84 +/- 3.58 D preoperatively to 47.90 +/- 3.58 D postoperatively (P<.001). Three eyes had ring exposure, and 1 eye had bacterial keratitis and ring exposure. CONCLUSION: Intacs implantation appeared to be effective in improving UCVA and BSCVA in patients with mild to moderate keratoconus and contact-lens intolerance.

Rate of cultivable subgingival periodontopathogenic bacteria in chronic periodontitis.

Although microbiological studies have identified more than 400 bacterial species in periodontal pockets, only a limited number have been implicated as periodontal pathogens. The purpose of this study was to investigate the incidence of cultivable subgingival periodontopathogenic bacteria in chronic periodontitis. Bacterial samples were collected with sterile paper points from the deepest periodontal pockets ((5 mm) of 203 patients: 92 males and 111 females, aged 35-55 years. The samples were cultured under anaerobic and capnophilic conditions using selective and non-selective media. Isolates were characterized to species level by conventional biochemical tests and a commercial rapid test system. The isolates were Actinobacillus actinomycetemcomitans (26.8%), Porphyromonas gingivalis (21.9%), Capnocytophaga sputigena (16.7%), Eikenella corrodens (13.2%), Prevotella intermedia (10.5 %), Prevotella disiens (3.1%), Peptostreptococcus micros (2.9%), Capnocytophaga gingivalis (2.2%), Prevotella corporis (1.8%), Peptostreptococcus magnus (1.3%) and Fusobacterium nucleatum (0.4%). No periodontopathogenic bacterial growth was observed in 14 of the samples (6.2%). The number of samples associated with monobacterial growth and polybacterial growth were 74.9% and 18.2% respectively. It is concluded that the bacterial composition associated with a number of patients' samples is quite complex, and that some of cultivable anaerobic and capnophilic bacteria act as periodontal pathogens in chronic periodontitis.