The use of antiadhesins--a new prospective trend in preventing and treating infectious diseases (a foundation for the technologies for creating drugs in the 21st century)

The state and prospects of research on creation of antiadhesins--new generation drugs for preventing and treatment of infectious diseases, are analyzed in the paper. The elaboration of such drugs is based on the profound knowledge about the nature of viral, bacterial, fungal and other infectious agents of diseases, molecular mechanisms of their interactions with the affected organs and tissues which are based on the processes of carbohydrate-protein recognizing. Rapid development of such fields of science as glycobiology and lectinology has created the preconditions for artificial synthesis of oligosaccharides which mimicked the receptors and can interact with adhesive structures of the disease agents more intensively than their natural analogs and block them. This makes the interaction of the latter with the affected organs impossible. The intensive work on elaboration of natural drugs: antiadhesins, is carried out in most countries. Adhesins are not harmful for people and cannot provoke the development of resistance to them in the disease agents. Till recently Ukraine belonged to the number of countries where the fields of science mentioned above were intensively developed but, in connection with the present stagnation of science and even the artificial hindering of its development, the country gradually losses the position of a leader. Hence, one can conclude that when 10-15 years later the market of pharmaceutical products will be filled with antiadhesins, our country will not be on the list of their producers, if the authorities will spend funds to buy foreign drugs as before instead of stimulating the development and production of the home ones.     

HAH1 is a copper-binding protein with distinct amino acid residues mediating copper homeostasis and antioxidant defense

HAH1 is a 68-amino acid protein originally identified as a human homologue of Atx1p, a multi-copy suppressor of oxidative injury in sod1 delta yeast. Molecular modeling of HAH1 predicts a protein structure of two alpha-helices overlaying a four-stranded antiparallel beta-sheet with a potential metal binding site involving two conserved cysteine residues. Consistent with this model, in vitro studies with recombinant HAH1 directly demonstrated binding of Cu(I), and site-directed mutagenesis identified these cysteine residues as copper ligands. Expression of wild type and mutant HAH1 in atx1 delta yeast revealed the essential role of these cysteine residues in copper trafficking to the secretory compartment in vivo, as expression of a Cys-12/Cys-15 double mutant abrogated copper incorporation into the multicopper oxidase Fet3p. In contrast, mutation of the highly conserved lysine residues in the carboxyl terminus of HAH1 had no effect on copper trafficking to the secretory pathway but eliminated the antioxidant function of HAH1 in sod1 delta yeast. Taken together, these data support the concept of a unique copper coordination environment in HAH1 that permits this protein to function as an intracellular copper chaperone mediating distinct biological processes in eucaryotic cells.     

Arnold-Chiari malformation in a captive African lion cub

PURPOSE: Surgery and systemic chemotherapy offer modest benefit to patients with recurrent glioblastoma multiforme. These tumors are associated with rapid growth and progressive neurological deterioration. Radiosurgery offers a rational alternative treatment, delivering intensive local therapy. A pilot protocol to treat recurrent glioblastoma was developed using fractionated stereotactic radiosurgery with concurrent intravenous (i.v.) Taxol as a radiation sensitizer. METHODS AND MATERIALS: The treatment outcome was analyzed in 14 patients with recurrent glioblastoma treated with fractionated stereotactic radiosurgery and concurrent Taxol. Median tumor volume was 15.7 cc and patients received a mean radiation dose of 6.2 Gy at 90% isodose line, 4 times weekly. The median dose of Taxol was 120 mg/m2. RESULTS: The median survival was 14.2 months, 1-year survival was 50%. CONCLUSIONS: Survival for this small group of patients was similar to or better than historical controls or patients treated with single-fraction radiosurgery alone. This data should stimulate the investigation of both fractionated radiosurgery and the development of radiation sensitizers to further enhance treatment.     

Psychosocial factors in children with idiopathic musculoskeletal pain: a prospective, longitudinal study

To explore the role of psychosocial factors in the development and persistence of idiopathic musculoskeletal pain (IMP) in children, 23 children with IMP and 52 children with juvenile chronic arthritis (JCA) were compared at first admission to hospital and at 9 y follow-up. Semistructured interviews were performed at both assessments. At first admission, the prevalence of psychiatric diagnoses was high both in patients with IMP and patients with JCA, but patients with IMP more often had pain models, reported more school stress and more often lived with one biological parent. At follow-up, overall psychosocial functioning and level of chronic family difficulties were improved in both groups, but patients with IMP had a higher prevalence of psychiatric diagnoses and more chronic family difficulties and life events than patients with JCA. The persistence of IMP at follow-up was related to pain models, school stress, less parental education and more chronic family difficulties at first admission. Findings support the association between psychosocial factors and childhood IMP.     

In vitro expression of the diphtheria toxin A-chain gene under the control of human chorionic gonadotropin gene promoters as a means of directing toxicity to ovarian cancer cell lines

OBJECTIVE: Our goal was to determine whether toxicity of the diphtheria toxin A-chain gene regulated by the human chorionic gonadotropin promoter can be directed to malignant ovarian cell lines. STUDY DESIGN: Plasmids containing diphtheria toxin A-chain gene linked to the regulatory elements of the metalloergothioneine and human chorionic gonadotropin promoters were transfected into the cell lines. Expression of diphtheria toxin A-chain gene was determined by the inhibition of a cotransfected luciferase reporter gene. RESULTS: Cytotoxicity of the diphtheria toxin A-chain gene is shown in a dose-responsive manner. Transfection of a plasmid expressing the diphtheria toxin A-chain gene controlled by a constitutive promoter readily inhibits protein synthesis. Specific inhibition of luciferase protein synthesis occurs in ovarian cancer cells transfected with the diphtheria toxin A-chain gene under the control of the human chorionic gonadotropin promoters when compared with normal ovarian epithelial cells or fibroblasts. CONCLUSIONS: These data demonstrate the preferential expression of the diphtheria toxin A-chain gene, regulated by the human chorionic gonadotropin promoter, to ovarian cancer cell lines. This provides an avenue for targeting such cells for suicide, toxin, or cytokine genes.     

Hodgkin's disease in patients older than 70 years of age: a registry-based analysis

Between 1973 and 1993, 529 patients aged 15 years and over with Hodgkin's disease (HD) were entered into a lymphoma registry. Twenty-eight cases (1 only diagnosed at autopsy) of histologically proven HD in patients aged 70 years or older were identified. The distribution of sex, 'B' symptoms, histology and stage was not significantly different from that of younger patients, except for the fact that there were no patients aged 70 years or older with lymphocyte predominant HD. Nineteen patients were treated radically, 5 patients palliatively and 4 patients received no radiotherapy or chemotherapy. Three of the 14 patients treated with chemotherapy achieved the planned dose intensity. The cause-specific 5-year survival was 75% for patients aged 15-69 years and 28% for patients aged 70 years and over (logrank chi(2) = 43.7, P < 0.00001). The younger and older groups treated with radical intent had complete response rates of 97% and 74%, respectively (logrank chi(2) = 17.91, P < 0.00001) and relapse rates at 5 years of 27% and 56%, respectively (logrank chi(2) = 4.86, P = 0.0275). The main reason for the poorer prognosis of patients aged 70 years and over was the increasing difficulty of chemotherapy delivery associated with advancing age.     

Mechanical stress induces release of ATP from Ehrlich ascites tumor cells

The supernatant from a suspension of Ehrlich cells exposed to centrifugation at 700xg for 45 s induced a transient increase in the intracellular concentration of free, cytosolic Ca2+, [Ca2+]i, as well as activation of an outwardly rectifying whole-cell current when added to a suspension of non-stimulated cells. These effects were inhibited by suramin, a non-specific P2 receptor antagonist, and mimicked by ATP. Reversed phase HPLC analysis revealed that the supernatant from Ehrlich cells exposed to centrifugation contained 2. 6+/-0.2 microM ATP, and that the mechanical stress-induced release of ATP was inhibited by glibenclamide and verapamil, non-specific inhibitors of the cystic fibrosis transmembrane conductance regulator and P-glycoprotein, respectively. After trypan blue staining, less than 0.5% of the cells were unable to extrude the dye. Addition of extracellular ATP induced a suramin-sensitive, transient, concentration-dependent increase in [Ca2+]i, activation of an outwardly rectifying whole-cell current and a hyperpolarization of the plasma membrane. The ATP-induced hyperpolarization of the plasma membrane was strongly inhibited in the presence of charybdotoxin (ChTX), an inhibitor of several Ca2+-activated K+ channels, suggesting that stimulation of P2 receptors in Ehrlich cells evokes a Ca2+-activated K+ current. The relative potencies of several nucleotides (ATP, UTP, ADP, 2-MeSATP, alpha,beta-MeATP, bzATP) in eliciting an increase in [Ca2+]i, as well as the effect of repetitive addition of nucleotides were investigated. The results lead us to conclude that mechanical stimulation of Ehrlich cells leads to release of ATP, which in turn stimulates both P2Y1 and P2Y2 receptors, resulting in Ca2+ influx as well as release and activation of an outwardly rectifying whole-cell current.     

Differences in airway closure between normal and asthmatic subjects measured with single-photon emission computed tomography and technegas

The absence of a maximal dose-response plateau as well as gas trapping and increases in closing capacity (CC) suggest that increased airway closure is an important mechanical abnormality of asthmatic airways. We compared the extent and distribution of airway closure in 13 normal and in 23 asthmatic subjects. Airway closure (LVclosed) was measured with single-photon emission computed tomography (SPECT) and an inhaled Technegas bolus as the percentage of lung volume without Technegas (LVtrans), and with CC, using nitrogen washout. LVclosed was compared in the apical, middle and lower zones, each being of equal vertical height. Values of mean LVclosed +/- 95% confidence interval (CI) were similar in normal (30 +/- 6.0% LVtrans) and asthmatic subjects (30 +/- 7.8% LVtrans). In normal subjects, LVclosed correlated with both age (r = 0.89, p < 0. 01) and CC (r = 0.86, p < 0.01), was more extensive in the lower zone (58 +/- 18.8% LVtrans, p < 0.01) than in the middle and upper zones (17 +/- 8.7% and 26 +/- 8.2 LVtrans, respectively), and increased with age in both the middle and lower zones (r = 0.94 and r = 0.90, respectively, p < 0.01). In asthmatic subjects, LVclosed did not correlate with age; was greatest in the lower zone, intermediate in the middle zone, and lowest in the apical zone (59 +/- 13.2%, 22 +/- 5.8%, and 12 +/- 4.4% LVtrans, respectively, p < 0. 01); and correlated weakly with age in the middle zone only (r = 0. 46, p < 0.05). We conclude that there is a predictable pattern of airway closure in normal subjects and that it is primarily influenced by pulmonary elastic recoil. This pattern is lost in asthmatic subjects. This may be explained by an increased range of closing pressures and a patchy distribution of airway closure, probably secondary to allergic inflammation.     

Design and synthesis of bio-isosteres of thymidine triphosphate

This paper describes the design and synthesis of potential isosteres of triphosphates which should show enhanced metabolic stability and lipophilicity compared to triphosphates. The triphosphate isosteres were then linked to nucleosides and evaluated for their inhibitory activity against HIV infection.