Design, synthesis, in vitro, and in silico evaluations of benzo[d]imidazole-amide-1,2,3-triazole-N-arylacetamide hybrids as new antidiabetic agents targeting α-glucosidase

α-Glucosidase as a carbohydrate-hydrolase enzyme is a crucial therapeutic target for type 2 diabetes. In this work, benzo[d]imidazole-amide containing 1,2,3-triazole-N-arylacetamide derivatives 8a-n were synthesized and evaluated for their inhibitory activity against α-glucosidase. In vitro α-glucosidase inhibition assay demonstrated that more than half of the title compounds with IC₅₀ values in the range of 49.0-668.5 μM were more potent than standard inhibitor acarbose (IC₅₀ = 750.0 µM). The most promising inhibitor was N-2-methylphenylacetamid derivative 8c. Kinetic study revealed that compound 8c (K_i = 40.0 µM) is a competitive inhibitor against α-glucosidase. Significantly, molecular docking and molecular dynamics studies on the most potent compound showed that this compound with a proper binding energy interacted with important amino acids of the α-glucosidase active site. Study on cytotoxicity of the most potent compounds 8c, 8e, and 8g demonstrated that these compounds did not show cytotoxic activity against the cancer and normal cell lines MCF-7 and HDF, respectively. Furthermore, the ADMET study predicted that compound 8c is likely to be orally active and non-cytotoxic.

Synthesis, ADMT prediction, and in vitro and in silico α-glucosidase inhibition evaluations of new quinoline-quinazolinone-thioacetamides

In this work, a new series of quinoline-quinazolinone-thioacetamide derivatives 9a-p were designed using a combination of effective pharmacophores of the potent α-glucosidase inhibitors. These compounds were synthesized by simple chemical reactions and evaluated for their anti-α-glucosidase activity. Among the tested compounds, compounds 9a, 9f, 9g, 9j, 9k, and 9m demonstrated significant inhibition effects in comparison to the positive control acarbose. Particularly, compound 9g with inhibitory activity around 83-fold more than acarbose exhibited the best anti-α-glucosidase activity. Compound 9g showed a competitive type of inhibition in the kinetic study, and the molecular simulation studies demonstrated that this compound with a favorable binding energy occupied the active site of α-glucosidase. Furthermore, in silico ADMET studies of the most potent compounds 9g, 9a, and 9f were performed to predict their drug-likeness, pharmacokinetic, and toxicity properties.

Design, synthesis, in vitro anti-α-glucosidase evaluations, and computational studies of new phthalimide-phenoxy-1,2,3-triazole-N-phenyl (or benzyl) acetamides as potential anti-diabetic agents

An important target in the treatment of type 2 diabetes is α-glucosidase. Inhibition of this enzyme led to delay in glucose absorption and decrease in postprandial hyperglycemia. A new series of phthalimide-phenoxy-1,2,3-triazole-N-phenyl (or benzyl) acetamides 11a-n were designed based on the reported potent α-glucosidase inhibitors. These compounds were synthesized and screened for their in vitro inhibitory activity against the latter enzyme. The majority of the evaluated compounds displayed high inhibition effects (IC₅₀ values in the range of 45.26 ± 0.03-491.68 ± 0.11 µM) as compared to the positive control acarbose (IC₅₀ value = 750.1 ± 0.23 µM). Among this series, compounds 11j and 11i represented the most potent α-glucosidase inhibitory activities with IC₅₀ values of 45.26 ± 0.03 and 46.25 ± 0.89 µM. Kinetic analysis revealed that the compound 11j is a competitive inhibitor with a K_i of 50.4 µM. Furthermore, the binding interactions of the most potent compounds in α-glucosidase active site were studied through molecular docking and molecular dynamics. The latter studies confirmed the obtained results through in vitro experiments. Furthermore, in silico pharmacokinetic study of the most potent compounds was also performed.

Natural inhibitors of SARS-CoV-2 main protease: structure based pharmacophore modeling, molecular docking and molecular dynamic simulation studies

Main protease (M^pro) plays a key role in replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study was designed for finding natural inhibitors of SARS-CoV-2 M^pro by in silico methods. To this end, the co-crystal structure of M^pro with telaprevir was explored and receptor-ligand pharmacophore models were developed and validated using pharmit. The database of “ZINC Natural Products” was screened, and 288 compounds were filtered according to pharmacophore features. In the next step, Lipinski’s rule of five was applied and absorption, distribution, metabolism, excretion, and toxicity (ADMET) of the filtered compounds were calculated using in silico methods. The resulted 15 compounds were docked into the active site of M^pro and those with the highest binding scores and better interaction including ZINC61991204, ZINC67910260, ZINC61991203, and ZINC08790293 were selected. Further analysis by molecular dynamic simulation studies showed that ZINC61991203 and ZINC08790293 dissociated from M^pro active site, while ZINC426421106 and ZINC5481346 were stable. Root mean square deviation (RMSD), radius of gyration (Rg), number of hydrogen bonds between ligand and protein during the time of simulation, and root mean square fluctuations (RMSF) of protein and ligands were calculated, and components of binding free energy were calculated using the molecular mechanic/Poisson-Boltzmann surface area (MM/PBSA) method. The result of all the analysis indicated that ZINC61991204 and ZINC67910260 are drug-like and nontoxic and have a high potential for inhibiting M^pro.

Design, synthesis, in vitro, and in silico enzymatic evaluations of thieno[2,3-b]quinoline-hydrazones as novel inhibitors for α-glucosidase

In the development of novel anti-α-glucosidase agents, we synthesized novel thieno[2,3-b]quinoline-hydrazones 9a-n by facile and efficient conventional chemical reactions. These compounds were characterized by IR, ¹H NMR, ¹³C NMR, and elemental analysis. Inhibitory activities of the title compounds were evaluated against yeast α-glucosidase. In particular, compounds 9c, 9d, and 9h exhibited high anti-α-glucosidase activity. Representatively, compound 9c with IC₅₀ = 1.3 µM, was 576-times more potent than positive control acarbose. Molecular docking study of the most active compounds showed that these compounds formed important binding interactions at α-glucosidase active site. Molecular dynamics study of compound 9c was also performed and the obtained results were compared with acarbose. Compounds 9c, 9d, and 9h were also evaluated for in silico druglikeness properties and ADMET prediction. These studies showed that the title most potent compounds could be exploited as drug candidates.

Gill lesions and mortality in common carp (Cyprinus carpio) with a dense bloom of Heterosigma-like algae in Khuzestan province

BACKGROUND

Widespread common carp (Cyprinus carpio) mortalities have been recorded in Khuzestan province fish farms in recent years. In summer of 2017 two cases of harmful algal bloom were encountered that led to massive mortality in common carp in Khuzestan, Iran.

AIMS

The aim of this study was to identify the possible etiologic agent of two mortalities with characteristic symptoms of gill lesions due to harmful algae.

METHODS

Water samples were collected and 5 moribund fishes were examined by histophatologic, scanning electron microscopic and PCR examination.

RESULTS

In wet smear preparations, a lot of algal cells and fragments, and sloughed, necrotic epithelial cells were observed between the lamellae. In histopathologic examination of gills, hyperplasia, necrosis and algal cells surrounded by hyperplastic cells were seen in tissue sections. No inflammatory cell aggregation was noticed. In scanning electron microscopic examination the algae was found attached to the gill surface (cell diameter: 8.5 ± 4.2 µm) with 2 equal flagella.

CONCLUSION

Phytoplankton analysis using direct microscopy and electron microscopy, morphologically resembling Heterosigma was identified, however, in PCR tests, Heterosigma analysis showed negative results, therefore the causative agent was called "Heterosigma-like" algae.

Vitamin D Receptor Gene Polymorphism: Association with Susceptibility to Early-Onset Breast Cancer in Iranian, BRCA1/2-Mutation Carrier and non-carrier Patients

Mounting evidences support that vitamin D insufficiency or deficiency is a risk factor of breast cancer. Vitamin D receptor (VDR) is expressed in more than 36 cell types in different organs as in cancerous cells. Numerous allelic variants of VDR gene have been identified in human populations. Association of FokI (rs2228570) and BsmI (rs1544410) single nucleotide polymorphisms (SNPs) in VDR gene with the risk of breast cancer have been investigated in several studies, however, the published data are still inconsistent. Here, we investigated BsmI and FokI polymorphisms in Iranian young (≤ 35 years old) breast cancer patient with known BRCA1/2 germline mutations. VDR gene polymorphisms were detected by restriction fragment length polymorphism (RFLP) analysis in a cohort of 203 breast cancer patients and 214 controls from Iran. There was a significant association between the bb and Bb genotypes of the BsmI and the increased risk of breast cancer (OR 1.74, CI 1.06-2.87 and OR 2.08, CI 1.31-3.29, respectively). This association was maintained in the subgroup of BRCA1/2 mutation non carriers (OR 1.90, CI 1.15-3.20 and OR 1.75, CI 1.07-2.87 for bb and Bb genotypes respectively) and in the subgroup of BRCA1/2 mutation non-carriers with a family history of breast and/or ovarian cancer (OR 1.81, CI 1.08-3.05 and OR 1.65, CI 1.00-2.70 for bb and Bb genotypes respectively). None of the FokI homozygous or heterozygous genotypes were associated with the risk of breast cancer. In summary, the BsmI polymorphism of VDR gene may be associated with the risk of breast cancer in Iranian women.

Human serum miR-34a as an indicator of exposure to ionizing radiation

Radiation exposure in industrial accidents or nuclear device attacks is a major public health concern. There is an urgent need for markers that rapidly identify people exposed to ionizing radiation (IR). Finding a blood-based marker is advantageous because of the ease of sample collection. This study was designed to test the hypothesis that serum miR-34a could serve as an indicator of exposure to IR. Therefore, 44 women with breast cancer, where radiotherapy was part of their therapeutic protocol, were investigated in this study. After demonstrating the appropriateness of our microRNA (miRNA) extraction efficiency and miRNA assay in human serum, we analyzed the miR-34a level in paired serum samples before and after radiotherapy. Fifty Gy X-ray irradiation in daily dose fractions of 2 Gy, 5 days per week, was used in this study. We demonstrated that IR significantly increased serum level of miR-34a. By measuring miR-34a in serum, we could distinguish irradiated patients with sensitivity of 65 % and specificity of 75 %. According to this study, serum miR-34a has the potential to be used as an indicator of radiation exposure.

Clinical translation of human microRNA 21 as a potential biomarker for exposure to ionizing radiation

This study investigated to what extent the serum microRNA 21 (miR-21) level alters in response to ionizing radiation (IR). Initially, we evaluated the appropriateness of our RNA extraction efficiency and microRNA assay in serum, and then investigated the serum miR-21 level in 4 patients with breast cancer in 4 stages: pre- and postoperation, at the beginning radiotherapy, and after 25 sessions of radiotherapy with a total of 50 Gy irradiation, as well as in 20 healthy volunteers. The initial analysis showed the appropriateness of our RNA extraction efficiency and microRNA assay in serum for identifying people exposed to IR. We then analyzed the serum miR-21 level in another group of 40 patients with breast cancer before and after radiotherapy. During our large-scale analysis, the miR-21 level before radiotherapy was comparable with healthy volunteers (P = 0.10) and increased significantly after radiotherapy (P < 0.001)-an indication that this could discriminate irradiated patients from nonirradiated ones with high specificity (75%) and sensitivity (80%). According to this study, serum miR-21 has the potential to be used as a biomarker for the identification of people exposed to ionizing radiation.

Human papillomavirus infection in lung vs. oral squamous cell carcinomas: a polymerase chain reaction study

The role of Human Papillomavirus (HPV) has been suspected in pathogenesis of various malignancies; however, the available data are not conclusive. This study aimed to determine and compare the frequency of HPV infection in oral and lung Squamous Cell Carcinoma (SCC) by a sensitive method. Sixty specimens of oral and lung SCC (30 cases each one) were reevaluated in Tabriz Imam Reza Centre in a 24 month period. Following genomic DNA extract, the Polymerase Chain Reaction (PCR) amplification was performed in presence of specific MY11 and MY09 primers for HPV infection. Three cervical specimens and a combination of PCR solution lacking DNA plus healthy persons' DNA samples were employed as positive and negative controls, respectively. The oral group was significantly older than the lung group (68.90 vs. 56.67 y, p < 0.001) with more males in the latter (83.3 vs. 60%; p = 0.04). Percentages of HPV infection in the oral and lung groups were comparable (20 vs. 10%, respectively; p = 0.47). Majority of patients with HPV infection were older than 60 years (88.9%) or male (88.9%). In the oral group, all these cases were well differentiated and the majority was of lower lip origin (83.3%). In the lung group, 66.7% of these specimens were moderately differentiated and the origin was bronchus in all cases. In conclusion, the rate of HPV infection in lung and oral SCC samples is rather lower than the previous reports in the literature. This rate is apparently higher in the oral than the lung SCC specimens.

Expression of epidermal growth factor receptor tyrosine kinase family in fine needle aspiration and permanent specimens of invasive lobular and ductal breast cancers

Recently, the role of HER-2/Neu gene amplification has been enthusiastically investigated in breast cancer. Determining the HER-2/Neu status could be achieved by evaluating either histologic samples or cytologic specimens obtained by Fine Needle Aspiration (FNA). This study aimed at determining the concordance of HER-2/Neu expression in FNA and histologic sections. FNA samples, as well as their corresponding histologic sections of 90 cases with breast cancer were evaluated in Tabriz Sina Teaching Center in a 13-month period of time. The immunohistochemistry was employed for determining the HER-2/Neu amplification for both methods. The concordance rate and agreement were determined between the two methods. Ninety specimens of women with a mean age of 50.93 +/- 10.64 (29-84) years were assessed. There were 84 cases with invasive ductal carcinoma and 6 cases with invasive lobular carcinoma. Lymph nodes were involved in 50 cases and there were vascular and neural involvement in 40 and 35 cases, respectively. Her-2/Neu was not detected in 27 cases (30%) with weak and strong amplifications in 47 (52.2%) and 16 (17.8%) cases of FNA specimens, respectively. Her-2/Neu was not detected in 29 cases (32.2%) with weak and strong amplifications in 42 (46.7%) and 19 (21.1%) cases of histologic specimens, respectively. The concordance rate was 70% between the two methods. The agree ment was statistically significant between the two methods, as well (kappa = 0.51, p < 0.001). HER-2/neu gene amplification can be reliably estimated by immunohistochemistry on breast cancer FNAs and a good correlation has been found between this and results on histological sections.

Cellular Response to Ionizing Radiation: A MicroRNA Story

MicroRNAs (miRNAs) represent a class of small non-coding RNA molecules that regulate gene expression at the post-transcriptional level. They play a crucial role in diverse cellular pathways. Ionizing radiation (IR) is one of the most important treatment protocols for patients that suffer from cancer and affects directly or indirectly cellular integration. Recently it has been discovered that microRNA-mediated gene regulation interferes with radio-related pathways in ionizing radiation. Here, we review the recent discoveries about miRNAs in cellular response to IR. Thoroughly understanding the mechanism of miRNAs in radiation response, it will be possible to design new strategies for improving radiotherapy efficiency and ultimately cancer treatment.

Effect of ghrelin on protein kinase C-ε and protein kinase C-δ gene expression in the pulmonary arterial smooth muscles of chronic hypoxic rats

INTRODUCTION

Protein kinase C (PKC), can be activated in pulmonary arterial smooth muscle cells during hypoxia, leading to hypoxic pulmonary vasoconstriction (HPV). Studies are going on to detect the strict PKC isoform involved in the phenomenon. It has been shown that ghrelin, a 28-amino-acid peptide, may protect lungs from HPV side effects, to some extent. The aim of study was to evaluate the effect of exogenous ghrelin on PKC-ε and PKC-δ gene expression during chronic hypoxia.

MATERIAL AND METHODS

Twenty-four adult male Wistar rats were divided randomly in 3 groups. Hypoxic rats with saline or ghrelin treatment were placed in a normobaric hypoxic chamber for 2 weeks. Controls remained in room air. PKC-ε and PKC-δ gene expression was measured by real-time RT-PCR.

RESULTS

Morphometric analysis showed that ghrelin reversed the hypoxia induced pulmonary artery wall thickness. In hypoxic animals, there was a 2- and 4-fold increment in PKC-ε and PKC- δ gene expression, respectively. Ghrelin treatment reduced the overexpression of PKC-ε and PKC-δ to control animals' value.

CONCLUSION

Ghrelin by decreasing the expression of PKC-ε and PKC-δ in hypoxic animals reduces the HPV. Although more studies are needed, it could be an honest deduction that ghrelin affects HPV in a multifunctional manner and might be used as a therapeutic agent in the future.

Expression of P27, Ki67 and P53 in squamous cell carcinoma, actinic keratosis and Bowen disease

This study aims at evaluating the expression of P27, Ki67 and P53 in Squamous Cell Carcinoma (SCC), Actinic Keratosis (AK) and Bowen Disease (BD) specimens. In an analytic-descriptive setting, skin biopsy specimens of 45 patients were evaluated in three 15-case groups including BD, AK and SCC specimens. Fifteen normal skin biopsy specimens were obtained and used as the control group. Immunohistochemical staining was performed in all the specimens and the expression rates and patterns of Ki67, P27 and P53 were determined. The results were compared between the four groups. Ki67 was expressed in 0.8, 23.7, 12.3 and 19.3% of the cells in the normal skin, AK, BD and SCC groups, respectively. No significant difference was seen between the three pathological conditions regarding the expression rate of Ki67. P27 was positive in 23.4, 26.2, 25.9 and 4.5% of specimens in the normal skin, AK, BD and SCC groups, respectively. This rate was significantly the lowest in the SCC group. P53 expression was detected in 26.6, 41.8 and 54.6% of the assessed cells in the AK, BD and SCC groups, respectively. There was no expression of P53 in the normal skin specimens. This rate was significantly the highest again in the SCC group. Based on these results, the quantitative and qualitative (pattern of distribution) evaluation of the expressions of Ki67, P27 and P53 may be helpful in differentiating malignant and premalignant epidermal lesions, particularly in unsatisfactory or fragmented specimens.

Copper binding to the PrP isoforms: a putative marker of their conformation and function

We show here that PrP(C), the normal isoform of the prion protein (PrP(Sc)), could be retained by a Cu(2+)-loaded resin through two different binding sites. Contrarily, PrP(Sc) was not retained at all by such resin. This constitutes a new prion-specific property of PrP(Sc), which in addition to protease resistance and beta-sheet content, may result from its aberrant conformation.

A protease-resistant prion protein isoform is present in urine of animals and humans affected with prion diseases

Prion protein (PrP)(Sc), the only known component of the prion, is present mostly in the brains of animals and humans affected with prion diseases. We now show that a protease-resistant PrP isoform can also be detected in the urine of hamsters, cattle, and humans suffering from transmissible spongiform encephalopathies. Most important, this PrP isoform (UPrP(Sc)) was also found in the urine of hamsters inoculated with prions long before the appearance of clinical signs. Interestingly, intracerebrally inoculation of hamsters with UPrP(Sc) did not cause clinical signs of prion disease even after 270 days, suggesting it differs in its pathogenic properties from brain PrP(Sc). We propose that the detection of UPrP(Sc) can be used to diagnose humans and animals incubating prion diseases, as well as to increase our understanding on the metabolism of PrP(Sc) in vivo.

Prion protein with an E200K mutation displays properties similar to those of the cellular isoform PrP(C)

Creutzfeldt-Jakob disease (CJD) in Libyan Jews, linked to the E200K mutation in PRNP (E200KCJD), is the most prevalent of the inherited prion diseases. As other prion diseases, E200KCJD is characterized by the brain accumulation of PrP(Sc), a pathologic conformational isoform of a normal glycoprotein denominated PrP(C). To investigate whether the E200K mutation is enough to de novo confer PrP(Sc) properties to mutant PrP, as suggested by experiments in Chinese hamster ovary cells, we examined the biochemical behavior of E200KPrP in brains and fibroblasts from sporadic as well as homozygous and heterozygous E200KCJD patients, asymptomatic transgenic mice carrying the E200K mutation, as well as in normal and scrapie-infected mouse neuroblastoma cells expressing E200KPrP. E200KPrP was examined for protease sensitivity, solubility in detergents, releasibility by phosphoinositol phospholypase-C and localization in cholesterol enriched membrane microdomains (rafts). In all tissues except in brains of CJD patients and ScN2a cells, E200KPrP displayed properties similar to those of PrP(C). Our results indicate that the E200K mutation does not automatically convey the properties of PrP(Sc) to new PrP molecules. A conversion process occurs mainly in the prion disease affected brain, suggesting the presence of a tissue-specific or age-dependent factor, in accord with the late onset nature of inherited CJD.

Further observations on the impact of a veterinary programme in Afghanistan on seasonal livestock mortality

This paper reports further results of a two year livestock mortality survey in Afghanistan, where a war of more than a decade had completely disrupted the veterinary field services. A questionnaire-based survey to measure the impact of a veterinary field programme indicated that average annual mortality in cattle, sheep, and goats was substantially lower in districts that received veterinary services (covered districts) than in districts without any veterinary services (control districts). The impact of the programme varies according to the season and the age group of the animals involved. The programme lacked impact in winter, in particular in adult small ruminants. The highest impact was noted in the spring and autumn for adult goats, and summer and autumn for adult sheep. The impact of the programme was also limited (in small ruminants even completely absent) during the suckling period in young animals. The highest impact was noted in the post-weaning period in small ruminants, when approximately four times more lambs and kids died in the control districts than in the covered districts. It was concluded that the major impact of the veterinary programme was achieved when animals are in contact with other flocks during grazing seasons, when parasitic and infectious diseases are present and against which the veterinary programme is directed. Additional inputs-including extension activities-are therefore required to improve the effect of the programme in the winter and in the neonatal period.

The anti-prion activity of Congo red. Putative mechanism

PrPSc, an abnormal conformational isoform of the normal prion protein, PrPC, is the only known component of the prion, a proteinacious agent that causes fatal neurodegenerative disorders in humans and other animals. The hallmark properties of PrPSc are its insolubility in nondenaturing detergents and its resistance to digestion by proteases. Anions such as Congo red (CR) have been shown to reduce the accumulation of PrPSc in a neuroblastoma cell line permanently infected with prions as well as to delay disease onset in rodents when administrated prophylactically. The mechanism by which such anti-prion agents operate is unknown. We show here that in vitro incubation with CR renders native PrPSc resistant to denaturation by boiling SDS. This resulted from PrPSc conformation, since neither the properties of PrPC nor those of predenatured PrPSc were changed by the addition of CR. CR-PrPSc could only be denatured by the addition of acidic 3 M guanidine thiocyanate. Since in vitro conversion experiments have suggested that partial denaturation may be required for PrPSc to serve as template in the PrPC --> PrPSc conversion, we propose that CR inhibits prion propagation by overstabilizing the conformation of PrPSc molecules.

Differential allelic expression of PrP mRNA in carriers of the E200K mutation

Creutzfeldt-Jakob disease (CJD) linked to the E200K mutation of the prion protein (PrP) gene presents with a wide range of age at disease onset. Since most patients are heterozygous for the mutation, we tested whether differential expression of mutant versus wild-type (wt) PrP may affect the age at disease onset in carriers of the mutation. We measured wt and mutant PrP protein and mRNA in Epstein-Barr virus (EBV)-transformed B cells of either E200K CJD patients or healthy E200K carriers. Our results suggests that while in most healthy carriers the expression of wt PrP was higher than that of E200K PrP, most of the E200K CJD patients express equal levels of both PrP proteins. Similar results were obtained for either PrP protein or PrP mRNA. These results suggest that preferential expression of PrP from the wt allele may modulate the outbreak of the disease in carriers of prion mutations. This notion is consistent with the results obtained in transgenic mice carrying a human PrP gene, which suggest that endogenous PrP protects mice from contracting scrapie after inoculation with human CJD brain. Similar mechanisms may prevail in other inherited diseases with variable phenotypes.

Detection of 14-3-3 protein in the CSF of genetic Creutzfeldt-Jakob disease

The 14-3-3 protein, a protein involved in signal transduction, is present in the CSF of patients with Creutzfeldt-Jakob disease (CJD) and not in patients with other dementing diseases. We show here that this is also true for patients with E200K CJD, but not for healthy carriers of the mutation.

Effect of scrapie infection on the activity of neuronal nitric-oxide synthase in brain and neuroblastoma cells

Nitric-oxide synthase (NOS) is responsible for the synthesis of nitric oxide which serves as a neural messenger in the central nervous system. NOS activity was markedly inhibited in brains of mice and hamsters and neuroblastoma cells infected with scrapie (ScN2a). The decrease in activity was in accordance with decreased NADPH-diaphorase-positive cells and decreased staining of NOS-positive cells demonstrated by specific anti-NOS antibodies. However, the specific nNOS mRNA in ScN2a was elevated when compared with normal neuroblastoma cells (N2a). Immunoblotting of fractions from these cell lines with an anti-nNOS monoclonal antibody revealed a band of nNOS from N2a and two bands with a lower molecular weight in ScN2a cells. Furthermore, NOS in ScN2a cells was insoluble in nondenaturing detergents. This insolubility is one of the landmark properties of PrPSc. It is, therefore, possible that nNOS in scrapie-infected cells and brains is aberrantly folded, resulting in an insoluble and inactive enzyme.

Livestock mortality in Afghanistan in districts with and without a veterinary programme

This paper reports on livestock mortality in Afghanistan where a war has been going on for more than a decade, with complete disruption of the veterinary field services. The study attempted to measure the impact of a veterinary field programme carried out mainly by paravets. The study also provides valuable data on the impact of diseases in the absence of any veterinary intervention. The veterinary programme, implemented by a Dutch non-governmental organisation (NGO) for approximately 3 years, consisted essentially of vaccination against major infectious diseases and administration of anthelmintic drugs for nematodes and liver flukes. Veterinary personnel were also involved in curative treatments. Livestock mortality figures were collected by questionnaire over a period of 2 years from more than 700 farmers in randomly selected villages in 4 covered districts with a veterinary programme and 4 control districts without a veterinary programme. The average annual mortality rates for calves, lambs and kids respectively were 16.2%, 17.3% and 19.1% in the covered areas, against 21.5%, 25.2% and 24.6% in the control areas. Adult mortality figures were 3.8%, 7.4% and 5.4% in the covered areas, against 5.3%, 13.6% and 15.6% in the control areas for cattle, sheep and goats respectively. The survey indicated significant differences (P < 0.01 in cattle, P < 0.001 in small ruminants) in livestock mortality between the control and covered areas and it is concluded that these differences were attributable to the presence or absence of the animal health programme.

Insoluble wild-type and protease-resistant mutant prion protein in brains of patients with inherited prion disease

We studied prion proteins (PrP) in skin and brains of Libyan Jews carrying the E200K mutation who died of familial Creutzfeldt-Jakob disease (CJD). Unexpectedly, studies with brain showed that PrP molecules encoded both by the wild-type (wt) and mutant alleles exhibit altered properties characteristic of the prion protein associated with prion diseases (PrPSc). Using monospecific antisera, we found that wtPrP was insoluble in the brains of three patients who were heterozygous for the E200K mutation, whereas mutant PrP was both insoluble and protease-resistant. Our results argue that both wild-type and mutant PrP undergo conformational changes and are particularly intriguing, because the normal isoform PrPc is soluble in nondenaturing detergents and is readily digested by proteases, whereas PrPSc is insoluble and resistant to proteolytic digestion. Our findings indicate that insoluble wtPrP represents a conformational intermediate, the first to be identified, within a pathway in which PrPc is converted to PrPSc.

Genetics and biochemistry of Creutzfeldt-Jakob disease in Libyan Jews

A focus of Creutzfeldt-Jakob disease (CJD) among Jews from Libyan origin was identified in Israel 20 years ago. The incidence of the disease in this ethnic group is about 100 times more than in the worldwide population. The consumption of lightly cooked sheep brain has been invoked to explain the high incidence of CJD in this community. The discovery of mutations in the PrP gene which segregates with other familial prion diseases such as Gerstmann-Straussler syndrome (GSS) lead us to perform a molecular genetic study and compare it to an epidemiological survey among the Libyan community. The epidemiological data suggests a very high familial incidence of CJD in this population and a molecular genetic research elucidated that CJD segregates with a point mutation at codon 200 of the PrP gene resulting in the substitution of Lysine for Glutamate. This mutation was found in some 40 CJD patients of Libyan origin and was not found in one Moroccan Jew suffering from CJD. It was also absent in almost 100 healthy Libyan controls above the age of 60. This result strongly supports a genetic etiology for CJD pathogenesis in the Libyan Jewish community and disregards the previous culinary hypothesis. The disease is vertically transmitted in autosomal dominant inheritance with unknown penetrance. All our patients were heterozygote for the mutation except one homozygote patient. The course of the disease in this patient was identical to the heterozygote patients, strongly arguing that inherited CJD displays complete phenotypic dominance.(ABSTRACT TRUNCATED AT 250 WORDS)

Heparin-like molecules bind differentially to prion-proteins and change their intracellular metabolic fate

PrPSc is the only known component of the scrapie prion. The difference between PrPSc and its normal isoform PrPc is probably conformational, since no difference has been found in the amino acid sequence or postranslational modifications between both proteins. Heparan sulfate (HS) has been shown to be a component of amyloid plaques in a number of diseases including the prion diseases. We now present evidence that PrP can specifically bind to heparin-like compounds and that this interaction might have a physiological significance. HS can increase the concentration of PrP in normal neuroblastoma cells, whereas low molecular weight heparin (LMWH) does not. In contrast, LMWH and other heparin-like molecules, excluding HS, can inhibit the synthesis of PrPSc in scrapie infected cells and reverse their phenotype back to normal as judged by measurement of PrPSc by immunoblotting and by infectivity experiments. Whether an interaction between PrP and glycosaminoglycans plays a direct role in the conversion of PrPc into PrPSc remains to be established.

Presence of prion protein in peripheral tissues of Libyan Jews with Creutzfeldt-Jakob disease

The prion protein (PrP) gene on chromosome 20 encodes a protein designated PrPC. An abnormal, protease-resistant isoform of PrPC, denoted PrPCJD or PrPSc, is present in the brains of patients with Creutzfeldt-Jakob disease (CJD). In Libyan Jews, CJD segregates with a point mutation at codon 200 of the PrP gene, resulting in the substitution of lysine for glutamate. In the present study, we examined the presence of PrP in fibroblasts and leukocytes derived from eight CJD patients with the codon 200 mutation. In cultured fibroblasts as well as in leukocytes, there was a significant increase in PrP as judged by immunocytochemistry in addition to immunoblotting. Most of the PrP in fibroblasts and leukocytes could be released from the external surface by phosphatidylinositol-specific phospholipase C, a property characteristic of PrPC. In leukocytes only, part of the protein was protease resistant, resembling PrPCJD. The concentration of PrP mRNA was similar in fibroblast lines derived from controls and CJD patients. These results suggest that in CJD patients carrying a mutation at codon 200 of the PrP gene, the metabolism of PrP, rather than PrP synthesis, is abnormal.

The initial slope of human tumor cell survival curves: its modification by the oxic cell sensitizer beta-arabinofuranosyladenine

The initial slope of the survival curve, which is a characteristic of each tumor cell line, varies with the histological group of the tumor. It is one of the factors on which clinical radioresponsiveness depends. The DNA dependant DNA polymerase inhibitor beta-ara A acts as an oxic cell sensitizer. This study was carried out on human tumor cell lines to look for a correlation between the degree of radiosensitization induced by beta-ara A and the radiosensitivity of a given cell line. Six human tumor cell lines with different radiosensitivities were used (the survival rate at 2 Gy and D ranged from 20 to 73% and from 1.2 to 3.2 Gy, respectively). beta-ara A had a major toxic effect on all cell lines but this varied greatly from one cell line to another and was concentration dependant; this toxic effect was taken into account when calculating the surviving fractions. For all cell lines, beta-ara A acted as an oxic radiosensitizer and the radiosensitization was concentration dependant. Analysis of the survival curves of the 6 cell lines using the linear quadratic model showed that concentrations of beta-ara A between 200 and 1000 microM induced an increase in the linear component while the quadratic component underwent no systematic change. The sensitizing enhancement ratio (SER) measured from the Ds ratios, varied greatly from one line to another. For example, at a concentration of 500 microM, the extreme values of Ds ratios were 1.5 and 2.6. The radiosensitization is greater, the higher the radiosensitivity of the cell line studied during exponential growth. The results do not favor the use of beta-ara A in the treatment of intrinsically radioresistant human tumors.

The effect of estradiol on human myelomonocytic cells. II. Mechanism of enhancing activity of colony formation

Elevated proportions of monocytes have previously been found in the blood of healthy women during the ovulation period as well as in other conditions associated with increased blood estradiol (E2). This phenomenon was explained, in part, by an augmenting effect which physiological concentrations of E2 may have on the development of granulocyte-macrophage (GM) colonies derived from normal peripheral blood mononuclear cells. To analyze this effect, we tested possible alternatives for the interaction between E2, colony-stimulating factor (CSF) and GM colony progenitor cells. E2 was found not to interact synergistically with CSF, but pre-treatment of the progenitor cells with E2 resulted in higher numbers of colonies in response to CSF. Moreover, E2 did not induce higher secretion of CSF but treatment with anti-CSF antibodies abolished the enhancing effect of E2. Based on these results, we suggest that the augmenting effect of E2 on GM colony formation is mediated by inducing the colony precursor cells to be more responsive to CSF. These findings may help to elucidate some of the complex relationships between estrogens, immune responses and hemopoiesis.

The effect of estradiol on human myelomonocytic cells. 1. Enhancement of colony formation

Cyclic changes were observed in the content of blood monocytes during the menstrual cycle of normal women. Elevated blood monocytes were found during the ovulation period as well as in other conditions which are associated with increased blood estradiol (E2). To understand the possible association between E2 and monocytosis, we analysed the in vitro effect of E2 on the development of myelomonocytic colonies in culture. E2 in physiological concentrations was found to increase the number of colonies developed from peripheral blood mononuclear cells (PBM) of both females and males. The optimal concentration for the augmenting effect on males' PBM was lower than that for females. Mononuclear cells derived from cord blood, which yielded much higher numbers of colonies than adult PBM, also responded to the stimulatory effect of E2. Estrone and estriol were less effective than E2 in adult PBM. In contrast, progesterone, diethylstilbestrol and testosterone did not affect the number of colonies at the range of physiological concentrations tested. The anti-estrogen Tamoxifen did not inhibit the stimulatory effect of E2. The augmenting effect of E2 on monomyelocytic colony formation may explain at least in part the increase in blood monocyte content of women with high E2 as well as other phenomena of macrophage and granulocyte changes associated with the menstrual cycle.

A new myelomonoblastic cell line (M20): analysis of properties, differentiation, and comparison with other established lines of similar origin

A new myelomonoblastic cell line (M20) was established from the peripheral blood of a ten-year-old child with acute myeloblastic leukemia, using an improved method for supporting the initial stages of cell proliferation. The addition of irradiated macrophage monolayers to the proliferating cells appeared to overcome the deterioration of the primary cultures and enable them to continue proliferating until they became independent of this environment. The cell line that developed consisted of myeloblasts and promyelocytes characterized by light and scanning electron microscopy, cytochemistry, and enzymatic activities. The cells expressed Fc receptors and WT1 antigens but did not exhibit HLA-DR, HMA1, Epstein-Barr virus nuclear antigen, and surface Ig. The M20 cells produced colonies when cultured in semisolid medium and secreted lysozyme, prostaglandin E2, and interleukin 1. An attempt was also made to analyse the position of the M20 cells in the scheme of differentiation of the myelomonocytic lineage using different approaches. Treatment of the cells with 12-O-tetradecanoyl phorbol 13-acetate induced their adherence to plastic surfaces and partial maturation to macrophages as judged by morphological criteria, cytochemistry, and enzyme activities. However, comparison of the M20 cells to other well-established myelomonoblastic cell lines did not reveal any pattern suggesting a possible relationship between surface markers, cell function, and differentiation pathway of the various cell lines tested. Establishment of additional cell lines and identification of new markers may assist in defining the mechanisms involved in normal differentiation and malignant transformation of this cell lineage. In addition, such cell lines may also provide a tool for the quantitative recovery of a variety of monokines.

Development of macrophage and granulocyte colonies from human peripheral blood

The presence of macrophage and granulocyte progenitor cells in the human peripheral blood enabled the establishment of colonies from this accessible tissue and obviated the need for bone marrow to achieve this task. We have developed a method of obtaining reproducible growth of macrophage/granulocyte colonies from human peripheral blood. Colonies of macrophages and granulocytes were obtained by plating peripheral blood mononuclear cells (PBM) in methylcellulose containing medium in the presence of medium conditioned by nonstimulated PBM (CM). At early stages of colony growth both macrophage and granulocyte colonies were detected while following 20-25 days in culture all colonies tested revealed monocyte-macrophage morphology. To obtain higher numbers of colonies, we tested different cell sources, different CM preparations and the effect of steroid hormones on colony development. We found that the mononuclear cells obtained from cord blood (CB) or from some patients with inflammatory bowel disease yielded much higher numbers of colonies than PBM from normal individuals. Colony development from these two sources did not depend on an external source of colony stimulating factor (CSF) but was augmented as a result of CSF supplementation. CM obtained from CB mononuclear cells as well as supernatants from some human monoblastic cell lines were similar in their CSF activity to CM from normal PBM and made possible the development of macrophage/granulocyte colonies. Higher numbers of colonies were induced by including physiological concentrations of estradiol in the culture medium, in the absence of external sources of CSF. The system described above enabled the analysis of cloned macrophages and their circulating progenitor cells as well as the assay of different preparations of CSF.

Marker analysis of cloned populations of human monocytes

The presence of myelomonocytic progenitor cells in human peripheral blood was used for the analysis of cloned populations of human monocytes. Colonies of granulocytes and macrophages were obtained by plating peripheral blood mononuclear cells (PBM) in methylcellulose containing medium in the presence of medium conditioned by nonstimulated PBM (CM). Following 20-25 days of incubation, most colonies were found to consist of cells with monocyte-macrophage morphology. Cloned populations of monocytes were tested for several monocyte membrane markers and compared to noncloned adherent monocytes. HLA-DR, 63D3, LeuM2 antigens and Fc receptors were expressed on cells from individual colonies in similar proportions to their expression on noncloned monocytes. Some colonies were uniform in their negative expression of the 63D3 antigen, as were the noncloned monocytes. Although the clonality of cells tested was not directly proven, these results indicated that at least for some monocyte markers, heterogeneous expression was obtained in monoclonal populations of monocytes. It is possible, however, that testing of additional markers and functions may reveal homogeneous clones of monocytes and suggest the existence of stable subsets.