The facilitatory actions of snake venom phospholipase A2 neurotoxins at the neuromuscular junction are not mediated through voltage-gated K channels

Electrophysiological investigations have previously suggested that phospholipase A₂ (PLA₂) neurotoxins from snake venoms increase the release of acetylcholine (Ach) at the neuromuscular junction by blocking voltage-gated K⁺ channels in motor nerve terminals.We have tested some of the most potent presynaptically-acting neurotoxins from snake venoms, namely β-bungarotoxin (BuTx), taipoxin, notexin, crotoxin, ammodytoxin C and A (Amotx C & A), for effects on several types of cloned voltage-gated K⁺ channels (mKv1.1, rKv1.2, mKv1.3, hKv1.5 and mKv3.1) stably expressed in mammalian cell lines. By use of the whole-cell configuration of the patch clamp recording technique and concentrations of toxins greater than those required to affect acetylcholine release, these neurotoxins have been shown not to block any of these voltage-gated K⁺ channels. In addition, internal perfusion of the neurotoxins (100 μg/ml) into mouse B82 fibroblast cells that expressed rKv1.2 channels also did not substantially depress K⁺ currents. The results of this study suggest that the mechanism by which these neurotoxins increase the release of acetylcholine at the neuromuscular junction is not related to the direct blockage of voltage-activated Kv1.1, Kv1.2, Kv1.3, Kv1.5 and Kv3.1 K⁺ channels.     

Association of HLA class II allele and haplotype frequencies with chronic myelogenous leukemia and age-at-onset of the disease

Chronic myelogenous leukemia (CML) is characterized by the presence of Philadelphia chromosome resulting from bcr/abl translocation. To clarify the association between HLA class II allele and haplotype frequencies in CML, 50 patients referred to Hematology Oncology and Bone Marrow Transplantation (BMT) center, Shariaty Hospital, Tehran, Iran, were randomly selected and compared with a group of 80 unrelated healthy blood donor subjects. HLA class II alleles were determined by PCR-SSP method. The results showed that the frequencies of DQB1*03011 (P=0.01) and DQA1*0505 (P=0.05) were higher, while that of DQB1*03032 (P=0.04) was lower in patients than in the controls. Regarding age-at-onset, the frequency of HLA-DRB1*07 (P=0.03) and -DQA1*0201 (P=0.03) alleles were higher in patients younger than 35 years. The most frequent haplotypes in our CML patients were HLA-DRB1*11/-DQB1*03011/-DQA1*0505 (P=0.01) and HLA-DRB1*04/-DQB1*0302/-DQA1*03011 (P=0.02). In conclusion, it is suggested that positive and negative association in certain HLA alleles and haplotypes exist in Iranian patients with CML.     

Ten Years’ Experience in Surgical Treatment of Right Middle Lobe Syndrome

Purpose: In this study we present the clinical, radiological, pathological, bronchoscopic and surgical results of 40 patients with diagnosis of middle lobe syndrome who were referred to our thoracic surgery unit for surgical intervention in a 10 years period.Methods: Forty patients with obstructive and non-obstructive causes of middle lobe syndrome referred to our thoracic surgery unit. Clinical data were collected from the patients’ records in a ten years period. This study evaluates diagnostic approaches and surgical treatments in right middle lobe syndrome.Results: We studied 23 females (57.5%) and 17 males (42.5%) with a mean age of 31.7. Clinical findings were cough 95%, sputum 80% and intermittent hemoptysis in 50% of patients. Middle lobe collapse was seen in CT scan of all patients. Bronchiectasis was the most common pathologic finding (55%). Tuberculosis was not rare and was final pathology in 20% of patients. In three patients ruptured hydatid cyst was final finding. Surgery was done without mortality and with only minor complications.Conclusion: Lobectomy of right middle lobe is a good therapeutic option in these patients. Due to high prevalence of tuberculosis and hydatid cyst in Middle Eastern countries these two must be considered as causes of middle lobe syndrome.     

Silver nanoparticles production by two soil isolated bacteria,Bacillus thuringiensis and Enterobacter cloacae,and assessment of their cytotoxicity and wound healing effect in rats

Production of silver nanoparticles by Bacillus thuringiensis and Enterobacter cloacae was performed and confirmed through UV–visible spectrophotometry, transmission electron microscopy (TEM), and x‐ray diffraction (XRD) analyses. The 3‐(4,5‐dimethylthiazol‐2‐yl)?2,5‐diphenyltetrazolium bromide (MTT) assay using mouse fibroblast cell line NIH‐3T3 D4 was carried out and IC_50s of AgNPs were obtained. The nontoxic dose of each AgNPs solution was selected for wound healing assay. Thirty‐two rats were divided into four groups; two were used as the controls and two were treated by AgNPs that were produced by two bacterial strains. Results revealed that the produced AgNPs were amorphous, spherical in shapes, and had sizes under 100 nm. Histological analysis showed that AgNPs had better wound healing efficacy than the control groups. In conclusion, when the biologically produced AgNPs were used in vivo, they induced the epithelization, formation of the collagen bundles and fibroplasia and reduced the duration of completion of the epithelization and the angiogenesis.     

Significant therapeutic response to cysteamine cream in a melasma patient resistant to Kligman's formula

L‐Cysteamine is a biological antioxidant produced during the coenzyme A metabolism cycle and is naturally present in all mammalian cells. The efficacy of topical cysteamine for the treatment of melasma has been recently shown in two double‐blind, randomized, and placebo‐controlled clinical trials. Herein, we report a 44‐year‐old patient with melasma resistant to Kligman's formula (Pigmanorm cream), who was successfully treated with topical cysteamine as a new depigmenting agent. Skin colorimetric measurements, MASI score determination, and standard photographies after 2 and 4 months of once daily application of cysteamine cream showed a marked improvement of the hyperpigmented lesions. Telangiectasia and perilesional hypopigmentation improved rapidly after the discontinuation of Kligman's formula and starting the treatment with topical cysteamine. After 4 months, the therapeutic results were maintained through a biweekly application regimen of cysteamine cream. The use of cysteamine cream was well tolerated and did not induce any side effects during the 3‐year follow‐up of the patient. Cysteamine is a natural molecule with an excellent safety profile and known antimutagenic, antimelanoma, and anticarcinogenic effects. Considering the high efficacy of cysteamine cream, it is possible that it could replace mutagenic and carcinogenic depigmenting agents such as hydroquinone in near future.     

IGF1 promoter polymorphism and cranial growth in individuals born very preterm

Background: Major defects in the IGF1 gene are associated with severely reduced cranial and linear growth. The association between IGF1 promoter polymorphisms and growth is uncertain. Aims: To test the effect of the IGF1 192-bp allele on cranial and linear growth and body mass index (BMI) from birth until age 5 years, and on IQ and serum IGF-1 at age 19 years. Methods: In a birth cohort, including 285 individuals born at a gestational age <32 weeks from the Project On Preterm and Small-for-gestational age infants (POPS), cohort anthropometric measurements were analyzed. At age 19 years IGF1 genotype, serum IGF-1 level and IQ were determined. Regression analyses were performed with mixed models. Results: Homozygotes for the 192-bp allele had a slower cranial growth from birth until age 5 years, and a tendency towards less brain sparing and a slower linear growth compared to the other 2 genotype groups. IGF1 genotype was not associated with IQ or BMI development. Head circumference SDS at age 5 years was positively associated with IQ at age 19 years. Conclusion: Homozygosity for the IGF1 192-bp allele is associated with a slower cranial growth from birth until age 5 years in individuals born very preterm.     

Effects of opium addiction on bleeding after coronary artery bypass graft surgery: report from Iran

Purpose  

Opium abuse is a major type of drug abuse in Iran. This study was designed to find the possible relation between opium addiction and excessive bleeding after coronary artery bypass graft (CABG) surgery.