Enhanced hippocampal long-term potentiation and learning by increased neuronal expression of tissue-type plasminogen activator in transgenic mice

Adult cortical neurons can produce tissue-type plasminogen activator (tPA), an extracellular protease that plays a critical role in fibrinolysis and tissue remodelling processes. There is growing evidence that extracellular proteolysis may be involved in synaptic plasticity, axonal remodelling and neurotoxicity in the adult central nervous system. Here we show that transgenic mice overexpressing tPA in post-natal neurons have increased and prolonged hippocampal long-term potentiation (LTP), and improved performance in spatial orientation learning tasks. Extracellular proteolysis catalysed by tPA may facilitate synaptic micro-remodelling, and thereby play a role in activity-dependent neuronal plasticity and learning.

Peripheral limb vascular malformations: an update of appropriate imaging and treatment options of a challenging condition

Peripheral vascular malformations encompass a wide spectrum of lesions that can present as an incidental finding or produce potentially life- or limb-threatening complications. They can have intra-articular and intraosseous extensions that will result in more diverse symptomology and present greater therapeutic challenges. Developments in classification, imaging and interventional techniques have helped to improve outcome. The onus is now placed on appropriate detailed preliminary imaging, diagnosis and classification to direct management and exclude other more common mimics. Radiologists are thus playing an increasingly important role in the multidisciplinary teams charged with the care of these patients. By fully understanding the imaging characteristics and image-guided procedures available, radiologists will be armed with the tools to meet these responsibilities. This review highlights the recent advances made in imaging and the options available in interventional therapy.

Plasma lipids in Iranians with sickle cell disease: hypocholesterolemia in sickle cell anemia and increase of HDL-cholesterol in sickle cell trait

BACKGROUND

The metabolism of lipids may be altered in sickle cell anemia and beta-thalassemia patients.

METHODS

Plasma lipids in 24 patients with sickle cell anemia (SS), 15 patients with sickle/beta-thalassemia (ST), 19 individuals with sickle cell trait (AS) and 62 healthy individuals (AA) were measured.

RESULT

Total cholesterol concentrations in both sexes with sickle cell anemia (SS males: 104.7, SS females: 142.7 mg/dl) and sickle/beta-thalassemia (ST males: 116.7, ST females: 137.5 mg/dl) were lower (P<0.05) than AS (AS males: 171.5, AS females: 185.4 mg/dl) and normal individuals (AA males: 173.7, AA females: 183.0 mg/dl). The mean HDL-cholesterol in males with SS (35.6 mg/dl) and ST (40.7 mg/dl) were (P=0.001) lower than AS males (58.9 mg/dl). However, the mean HDL-cholesterol in females with SS (43.2 mg/dl) was lower (P<0.001) than AS females (62.7 mg/dl). The mean LDL-cholesterol of males with SS (53.8 mg/dl) was lower (P<0.01) than AS (89.4 mg/dl) and control males (115.9 mg/dl). Males with ST had a lower (P<0.001) LDL-cholesterol (58.0 mg/dl) compared to control males. In females with SS the LDL-cholesterol (78.3 mg/dl) was lower (P<0.001) than control females (124.3 mg/dl). However, females with ST had lower (P<0.05) LDL-cholesterol (61.6 mg/dl) than AS (101.7 mg/dl) and control females. There was no significant difference in total concentrations of cholesterol and triglycerides between males and females with AS and those with normal hemoglobin. However, the HDL-cholesterol in both genders with AS was higher (P<0.001) than normal subjects. Also, the concentration of LDL-cholesterol in both males and females with AS was lower than control males (P<0.05) and females.

CONCLUSIONS

Hemolytic stress could be associated with a significant reduction in plasma lipids and lipoproteins. It appears that patients with sickle cell anemia and individuals with sickle cell trait are at a lower risk for coronary artery disease.

Detection and identification of non-tuberculous mycobacterial infections in 6,472 tuberculosis suspected patients

Between March 1993 and March 1994, 82 patients with infection by non-tuberculous mycobacteria (NTM) and 443 patients with tuberculosis (TB) were registered among 6,472 patients with suspected tuberculosis. Skin-test reactivity to purified protein derivative (PPD) in patients demonstrated indurations of 10-14 mm or more for the majority of patients in both groups. Most patients with NTM infection had abnormal chest roentgenograms showing sporadic infiltrations, nodular abscesses, and cavities resembling TB radiological evidence. The similarity in age range, PPD skin reaction, and radiological evidence in patients infected with NTM or Mycobacterium tuberculosis (MTB) can mislead the physician. Some NTM species were recovered more often than others. Mycobacterium fortuitum from 22 clinical specimens (26.8%); Mycobacterium gastric 19 (23.1%); and Mycobacterium terrae complex 15 (18.3%). The antimicrobial drug susceptibility tests of the isolated organisms showed that 42 (9.5%) isolates of MTB were resistant to isoniazid and 31 (7.0%) to streptomycin. a few strains (1.3%) were identified as being resistant to a combination of 3 primary drugs. These findings suggest that drug-resistant mycobacterial infections are becoming an important problem in the region.

Molecular epidemiology of bluetongue virus serotype 1 isolated in 2006 from Algeria

This study reports on an outbreak of disease that occurred in central Algeria during July 2006. Sheep in the affected area presented clinical signs typical of bluetongue (BT) disease. A total of 5245 sheep in the affected region were considered to be susceptible, with 263 cases and thirty-six deaths. Bluetongue virus (BTV) serotype 1 was isolated and identified as the causative agent. Segments 2, 7 and 10 of this virus were sequenced and compared with other isolates from Morocco, Italy, Portugal and France showing that they all belong to a 'western' BTV group/topotype and collectively represent a western Mediterranean lineage of BTV-1.

The effects of selenium and other micronutrients on the antioxidant activities and yield of corn (Zea mays L.) under drought stress

The effects of selenium (Se) on plant growth under drought stress and in the presence of micronutrients are yet to be investigated. Hence, in a field experiment in 2007 the effects of Se and micronutrients including iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), boron (B) and molybdenum (Mo) were evaluated on corn (Zea mays L.) grain yield under drought stress. Main- and sub-plots were devoted to irrigation (control and water stressed at the eight-leaf, blister and grain filling stages) and micronutrients treatments, respectively. Micronutrients were foliarly applied at 2 l ha(-1) at the six-leaf stage, one week before tasseling, using a corn fertilizer, called biomin containing (on the basis of dry weight percentage) Fe (2.6), Zn (4.1), Cu (1.5), Mn (2.6), B (1.5), Mo (0.5) and Mg (4.1). Se was used as sodium selenite (Na2SeO3), at the rate of 20 g ha(-1) two weeks before treating the plants with drought stress. Effects of drought stress on plant growth were determined based on the activity or level of antioxidants. With increasing the stress level, addition of Se or micronutrients significantly enhanced the antioxidant activity and level as well as corn grain yield. The interaction effects between Se and micronutrients adversely affected antioxidant activity as well as corn grain yield. Se addition at the grain filling stage resulted in the highest grain yield under drought stress. The single but not the combined use of Se or micronutrients can alleviate the unfavorable effects of drought stress on corn yield by affecting plant metabolism including antioxidant activity.

Lack of association between MTHFR C677T and A1298C polymorphisms and risk of childhood acute lymphoblastic leukemia in the Kurdish population from Western Iran

AIMS

Polymorphism in genes involved in folate metabolism may influence the susceptibility to acute lymphoblastic leukemia (ALL). The aim of the present study was to determine the role of the two most common polymorphisms of the 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene, MTHFR C677T and A1298C, and their interaction on the susceptibility to ALL.

METHODS

Seventy-two children with ALL and 109 age- and sex-matched healthy children from Western Iran were screened for MTHFR C677T and A1298C variants by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

The frequencies of MTHFR 677T and 1298C alleles in patients were 29.9% and 43.1%, respectively, that were higher than those in controls (24.8% and 38.1%, respectively). Logistic regression analysis was performed and its result in the odds ratios (ORs) for possession of either MTHFR 677T or 1298C allele was found to be 1.98 [95% confidence interval (CI) 0.72-5.4, p = 0.18] and 1.48 (95% CI 0.59-3.69, p = 0.4), respectively. Also the concomitant presence of both MTHFR 677T and 1298C alleles was not associated with the risk of ALL [OR = 2.12 (95% CI 0.8-5.7, p = 0.13)].

CONCLUSION

Our results in a homogenous population with Kurdish ethnic background indicated that neither the MTHFR 677T allele nor the MTHFR 1298C allele is associated with increased risk of ALL.

Paradoxical embolus illustrating speed of action of recombinant tissue plasminogen activator in massive pulmonary embolism

A case of a patient who presented with massive pulmonary embolism (PE) requiring thrombolysis with alteplase is reported. The subsequent presence of a patent foramen ovale and paradoxical embolism clinically demonstrated the speed of action of the recombinant tissue plasminogen activator. The advantage of this class of medication when considering the treatment options for a PE in an acute setting is highlighted.

Protective and Therapeutic Effects of Aloe Vera Gel on Ulcerative Colitis Induced by Acetic Acid in Rats

Ulcerative colitis (UC) is a chronic intestinal inflammation. Common clinical symptoms are weight loss, diarrhea, ulcers, and inflammation. Aloe vera (AV) has several medicinal properties including antioxidant, anti-inflammatory analgesic, and improvement of gastric and skin ulcers. This study aimed to investigate the protective and therapeutic effects of AV gel on acetic acid-induced UC in rats. UC was induced in 48 rats by injection of 4% acetic acid into the rectum. Protective and treatment groups received treatments 7 days before and after the induction of colitis, respectively. The negative control group, the positive control group, and AV groups received distilled water, sulfasalazine, and 50 and 300 mg/kg of gel extract, respectively. Water and food intake and body weight changes were recorded. The extent of the mucosal ulcers, colon tissue thickening, and mucosal bleeding were scored by the Gerald classification system score (microscopy observations). Slides of tissues were prepared for pathologic assay using the modified Wallace method (macroscopic observations). The results of the macroscopic and microscopic examination showed protective and therapeutic effects of 50 mg/kg dose of AV on acetic acid-induced colitis in rats which reduces the inflammation, ulcers and tissue damage compared with negative control (p < 0.05). There were no significant changes in the amount of water and food intake, body weight changes, and colon weight in protective and treatment groups. Based on the results, AV gel could be used to improve the symptoms of UC, as well as prevent people who are susceptible to the UC.

Partial characterization of a nonmicellar system of cholesterol solubilization in bile

We have shown that there were two distinctly separate cholesterol-containing fractions in human hepatic and gallbladder bile. In addition to mixed micelles that were composed of bile salts, cholesterol, and phospholipids and measured at approximately 25 A by quasi-elastic light scattering spectroscopy, there was a nonmicellar fraction made up of cholesterol and phospholipids with no, or only trace amount of bile salts. This fraction had a mean hydrodynamic radius of 600 A. When studied with electron microscopy, the fraction consisted of particle spherical in shape that measured 900-1,300 A in diameter and were monodisperse. This form of cholesterol had a low buoyant density of less than 1.05 g/ml by density gradient ultracentrifugation and eluted as a macromolecular aggregate (mol wt greater than 200,000) employing Sephadex G-75 chromatography. The quantity of nonmicellar cholesterol in bile correlated positively with the cholesterol saturation index (r = 0.649; P less than 0.001) and inversely with relative bile salt concentration (r = -0.572, P less than or equal to 0.03) and total lipid concentration (r = -0.844, P less than 0.0001). In vitro and in vivo addition of bile salts resulted in a shift of nonmicellar cholesterol to micellar cholesterol. In hepatic bile, nonmicellar cholesterol was the predominant and sometimes the exclusive form of cholesterol transport. When nucleation experiments were performed on gallbladder bile samples, the cholesterol that had nucleated were almost exclusively derived from the nonmicellar fraction.

Polymerase chain reaction of bacterial genomes with single universal primer: application to distinguishing mycobacteria species

The polymerase chain reaction with a single universal primer (UP-PCR) was applied to bacterial strains and mycobacteria isolates alongside conventional methods. A universal protocol of preparation of PCR samples from cultures representing Escherichia coli, Enterobacter aerogenes, Serratia marcescens, Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, Mycobacterium tuberculosis, Mycobacterium bovis, and several non-tuberculous mycobacteria was found to be reproducible and efficient with these organisms. The bands of UP-PCR products observed in an agarose gel after electrophoresis were species-specific and provided an efficient means of distinguishing bacterial species. The applicability of this approach to mycobacteria identification was assessed by comparing the DNA bands obtained for different strains. Three reference strains and 22 clinical isolates of M. tuberculosis and M. bovis produced very similar DNA banding patterns. They comprised a triplet of prominent and several minor fragments within the 200-500 base pair (bp) size range and were the easiest to interpret. The DNA profiles of unrelated mycobacteria clearly differed from each other when subjected to electrophoretic analysis and correlated well with results of culture method. The method provides a real promise of its application in clinical studies as a simple assay for distinguishing between tubercle bacilli.

Comparison of the risk factors and HPV types in males with anogenital warts with and without involvement of the urethral meatus in western Iran

BACKGROUND

Human papillomavirus (HPV)-induced lesions rarely develop in the urethral meatus (UM); however, their eradication can be problematic.

METHODS

A total of 22 patients with anogenital warts (AGWs) in the UM region and 22 patients with AGWs located at other anatomical sites were included in this cross-sectional study. The presence of human papillomavirus (HPV) types in biopsy samples was determined using the HPV Easy typing kit (GenID GmbH, Germany).

RESULTS

Although the patients in the AGW group with involvement of the UM had a higher incidence of reported multiple sexual partners (63.6% vs. 40.9%), larger meatus size (81.8% vs. 36.4%), and more frequent anal (36.4% vs. 18.2%) or unprotected sexual contact (68.2% vs. 36.4%) than those in the AGW group without UM involvement, only the duration of lesions (p = 0.04) and meatus size (p = 0.004) were significantly different in both groups. Low-risk HPV types were found in 75.0% and 69.2% of patients in the AGW groups with and without UM involvement, respectively.

CONCLUSION

We found that a larger UM size was more prone to the development of meatus AGWs; however, being married, delaying sexual debut, and avoidance of multiple sexual partners seemed to be associated with a decreased risk of development of AGWs, especially within the UM region.

To differentiate benign from malignant thyroid nodule comparison of sonography with FNAC findings

Objectives: To evaluate the diagnostic accuracy of sonography and Fine Needle Aspiration Cytology (FNAC).

Methodology: This follow-up study was approved by review board and conducted at Endocrine Clinic and Radiology Department of Imam Reza, Kermanshah. The patients were diagnosed to have thyroid nodule examined by FNA and Sonography suspicious malignant cases underwent surgery. Results were entered in SPSS 11.5 chi-Square and Fisher exact test applied to compare malignant and benign nodule characters.

Results: In this study 144 patients were examined and 14 cases (9.7%) had malignant nodule. Most of malignant nodules were single (p=0.001), solid (p < 0.001), hypo-echo (p=0.001), with irregular margins (p < 0.001) and with calcification (p=0.041). There was no significant relationship between malignancy and nodule size of larger than 15 mm (p=0.395). Compared with surgery, FNA sensitivity and specificity were calculated as 92.8% and 100% respectively.

Conclusion: Based on the result of this study, thyroid nodule size must not be considered as a criterion for malignancy and thyroid nodules of any size must be suspected as malignant. Important criteria for malignancy include irregular edges, being solid, hypoechogenicity and being a single nodule respectively. Compared with Surgery, FNA Sensitivity and specificity were calculated as 92.8% and 100% respectively.

Lipid peroxides in the serum of asphyxiated neonates

OBJECTIVE

Lipid peroxides (LPOs) are released when free radicals react with unsaturated fatty acids in cell membranes during hypoxic ischemic insult in neonates. We aimed to assess LPO concentrations in the serum of asphyxiated and non-asphyxiated neonates and examine their correlation with the severity of asphyxia.

STUDY DESIGN

This prospective cross-sectional study was conducted on a group of asphyxiated neonates and controls. Serum LPO concentrations was measured by enzyme-linked immunosorbent assay at 4-6 h of life in all subjects. Encephalopathy was classified according to Sarnat's stages into mild, moderate and severe at 12-24 h of life. LPO was compared between groups and was correlated with severity of encephalopathy and mortality.

RESULTS

A total of 90 infants were enrolled; of them 45 had asphyxia. Serum LPO (nmol ml(-1)) was significantly greater in the asphyxia group (6.9±3.01 vs 1.78±1.09, P<0.001). It correlated positively with severity of encephalopathy (P<0.001) and negatively with Apgar score at 5 min (r=-0.532, P<0.001) and with initial blood gases pH (r=-0.664, P<0.001). LPO measured greater concentrations in infants who died compared with asphyxiated survivors (11.64±1.31 vs 6.18±2.48, P=0.0004).

CONCLUSION

LPO was increased and correlated with severity of asphyxia as well as with mortality. Further studies are warranted to examine whether it is only a marker for outcome or a contributor in the pathogenesis of hypoxic-ischemic brain injury.

Interconversions of lipid aggregates in rat and model bile

The dynamic interchange of cholesterol and the phase transition between nonmicellar and micellar aggregates in rat and model bile were characterized with gel-permeation chromatography, quasi-elastic light scattering, turbidity measurements, and by radiolabeling lipid aggregates in bile. Cholesterol partitioned into either the micellar or nonmicellar phases independent of the lipid aggregate structure. In model bile, increasing bile salt concentrations led to a decrease in the relative proportion of nonmicellar aggregates beginning at 5 mM taurocholate (TC), while the relative cholesterol content of the nonmicellar fraction increased from 1.0 to 2.7 +/- 2.0 (means +/- SD). In rats, creation of a biliary fistula resulted in a decrease of bile salts from 41 to 4 mM. Mixed micelles increased from 25 to 120 A in radius, while nonmicellar aggregates increased from 180 to 800 A in radius. Addition of TC to model bile (cholesterol:lecithin = 1:1) vesicles with total lipid concentrations less than 7 mM yielded a progressive shift of vesicles (450 A) to mixed micelles (30 A). For mixtures with higher total lipid concentrations, addition of TC promoted substantial vesicle aggregation and resulted in formation of a third phase containing lipid aggregates larger in size than the initial vesicles. These results suggest that rapid exchange of cholesterol occurs in bile and that significant remodeling of vesicles can occur. These alterations in vesicles include both enrichment in cholesterol content and formation of larger aggregates during increases in bile salt concentration.

Acute hepatitis with portal and mesenteric vein thrombosis revealing SARS-CoV-2 infection: Case report and literature review

Novel coronavirus disease 2019 (COVID-19) is a single-stranded RNA virus identified for the first time in Wuhan, China, and it unfurls quickly worldwide. The corona virus 2019 is a systemic disease which develops a prothrombotic environment, and has an extensive spectrum of clinical presentations in the gastrointestinal and hepatobiliary systems. Ischemic hepatitis (hypoxic hepatitis) is one potential mechanism behind lessened perfusion of the liver. The portal and mesenteric vein thrombosis are extremely rare complications and unusual main manifestations of COVID-19. We report the case of a patient presented acute hepatitis with portal and mesenteric vein thrombosis revealing a SARS-CoV-2 infection. In addition, we discuss the most characteristic elements of the Impact of COVID-19 on liver Injury, and the mechanisms of this damage and the formation of thrombus in portal and mesenteric vein.

Soluble tumor necrosis factor (TNF) receptors are effective therapeutic agents in lethal endotoxemia and function simultaneously as both TNF carriers and TNF antagonists

Two forms (monomeric or dimeric) of the extracellular, ligand-binding portion of the human p80 cell-surface receptor for TNF were used to antagonize TNF activity in vitro and in vivo. The dimeric sTNFR:Fc molecule was a more potent inhibitor of TNF than the monomeric sTNFR (50 to 1000x), as assessed in vitro by inhibition of TNF binding or bioactivity and in vivo by protection of mice from an otherwise lethal injection of LPS. Surprisingly, the dimeric sTNFR:Fc construct demonstrated a beneficial effect even when administered 3 h after a lethal LPS injection (i.e., after serum TNF levels had peaked and receded). To study the mechanism by which the soluble TNFR functions in vivo, serum TNF levels were examined in mice given LPS in the presence or absence of soluble receptor. Administration of a mortality-reducing dose of sTNFR:Fc ablated the rise in serum TNF bioactivity that normally occurs in response to LPS. However, TNF bioactivity was revealed in these "TNF-negative" serum samples when the L929 bioassay was modified by inclusion of a mAb that blocks the binding of murine TNF to the human soluble TNFReceptor. These results indicate that the absence of direct cytolytic activity in the L929 assay was caused by neutralization of TNF, rather than to an absence of TNF in the serum. Moreover, administration of either monomeric sTNFR or low doses of dimeric sTNFR:Fc actually resulted in increased serum TNF levels compared to mice given LPS but no soluble receptor. However, these "agonistic" doses of soluble receptor did not lead to increased mortality when an LD60 dose of LPS was given. Thus, dimeric sTNFR are effective inhibitors of TNF and under some circumstances function simultaneously as both TNF "carriers" and antagonists of TNF biologic activity.