Relationship between the binding sites for an alpha-conotoxin and snake venom neurotoxins in the nicotinic acetylcholine receptor from Torpedo californica

Photoinduced cross-links between the iodinated Lys26-p-azidobenzoyl derivative of neurotoxin II from Naja naja oxiana cobra venom and nicotinic acetylcholine receptor from Torpedo californica (AChR) have been studied in the presence of alpha-conotoxin GI from the marine snail C. geographus. Preincubation of the AChR-enriched membranes with increasing concentrations of alpha-conotoxin GI protects first the gamma subunit from photolabelling and then the delta subunit, the IC50 values being 0.76 and 5.01 microM, respectively. The results obtained, in view of the relevant data in literature, demonstrate that the (alpha + gamma) site, which is the high affinity site for d-tubocurarine, has also a higher affinity for an alpha-conotoxin than the (alpha + delta) containing site. The latter has a somewhat higher affinity than the (alpha + gamma) site towards some naturally occurring snake venom alpha-neurotoxins or their derivatives.     

Functional activity of peripheral blood neutrophils of rats during combined effects of hypoxia, hypercapnia and cooling

Functional activity of neutrophilic leukocytes was studied in blood of rats immediately following single and repeated gradual increase in carbon dioxide and decrease in oxygen concentrations with the ambient temperature at 2 to 3 degrees C. Phagocytic activity was shown to alter as the number of phagocytic neutrophilic granulocytes, absorptivity or the phagocytic index, and the coefficient of phagocytosis completeness were elevated and levels of oxygen-dependent and oxygen-independent metabolism were reduced.     

Eruption times of third molars in young rural Nigerians

The mechanical stability of proximal femoral osteotomies fixed by the tension band wire technique was studied in flexion-compression and torsion tests. The fixation consisted in crossing the section with two Kirschner wires and with a wire cerclage applied to the tension surface. The study was conducted in three steps. First, cyclinders of wood were cut either transversely or at 30 degrees of inclination in relation to the long axis of the specimen, and fixed with two Kirschner wires and a wire cerclage. We concluded that the inclination of the plane of section significantly increased the stability of fixation. No significant difference was observed when oblique sections were made in the reverse orientation. Second, 30 degrees subtrochanteric varus osteotomies were performed in dog femurs, so that the section plane was transverse in one group and oblique in another, after closing the osteotomy. In both groups the fixation was achieved by two Kirschner wires that crossed the osteotomy and a wire cerclage placed on the lateral cortex (tension surface). We concluded that inclination of the osteotomy plane increased the stability of osteosynthesis in bone specimens, as already seen with the wood pieces. Third, the stability of tension band wire fixation was compared with that provided by the AO/ASIF paediatric angled plate. Varus osteotomies (30 degrees) were created at the subtrochanteric level of paired dog femurs. On one side, the femur was fixed with Kirschner wires and a wire cerclage as described previously. For the other femur, the osteotomy was fixed with the angled plate. We found that both types of fixation presented the same stability in flexion-compression tests. However, under torsion the tension band wire fixation was 30%-50% less stable than the plate fixation.     

Effect of calmodulin on the activity of NAD-kinase from rabbit liver

It has been shown that rabbit liver NAD-kinase is a Ca(2+)-dependent, calmodulin-regulated enzyme. Differences were found between the sensitivity of the alpha- and beta-forms of the enzyme to calmodulin. The maximal activation of the NAD-kinase alpha-form was observed at a calmodulin/NAD-kinase ratio equal to 2, that of the beta-form--at 4. Further increases in the above parameter (up to 10) had no effect on the activity of the alpha-form, whereas that of the beta-form dropped down to the initial (basal) level.     

An alternative approach to the surgical correction on malpositions of the uterus]

Endosurgical correction of the uterus was carried out in 57 patients. Indications for surgery were improper positions of the uterus-retroversio, retrodeviatio uteri, excessive mobility of the uterus, and complaints of heaviness at the bottom of the abdomen, leukorrhea, pain of different type in the lower portions of the abdomen, profuse and long menses, dyspareunic pain upon deep penetration, reduced libido, a sensation of a foreign body in the vaginal cleft, urine incontinence upon strain. The mean age of the patients was 35 +/- 3 years. The disease duration varied from 1 to 8-9 years. In 9 women endosurgical correction of the uterus was combined with other interventions on the pelvic organs: colpoperine-orrhaphy with levator plasty was carried out in 5, laparoscopic myomectomy in 2, and dissection of intraperitoneal adhesions in 2 patients. In addition, surgical sterilization was carried out in 54 patients. After surgery the patients were administered only nonnarcotic analgetics. All the patients were discharged on days 2-3, those subjected to combined treatment on days 8-9. The patients were followed up for up to 2 years. The general and psychoemotional status of the majority of patients improved, and the incidence of such symptoms as leukorrhea, pain at the bottom of the abdomen, profuse and long menses was 4, 6, and 5 times reduced, respectively. Endosurgical correction of the uterus in women of a reproductive age should be a method of choice; it can be carried out separately or in combination with plasty of the vaginal walls.