Naja melanoleuca cobra venom contains two forms of complement-depleting factor (CVF)

Two forms of complement-depleting cobra venom factor (CVFm1 and CVFm2), possessing molecular masses of 142.6 kDa (CVFm1) and 143.1 kDa (CVFm2), according to MALDI mass-spectrometry, were isolated from the Naja melanoleuca cobra venom. As shown by polyacrylamide gel electrophoresis in the presence of SDS, both forms similarly to factor from the Naja kaouthia cobra venom (CVFk) consist of three polypeptide chains with molecular masses of about 70, 50, and 30 kDa, the two large subunits being glycosylated. As determined by MALDI mass-spectrometry, 30 kDa subunits of CVFm1 and CVFm2 have considerably different finger-prints of tryptic digests that suggests differences in their amino acid sequences. A study of activity in vivo has shown no significant differences in C3 consumption by CVFm1, CVFm2 and CVFk in mouse blood. However, as shown by an immunoassay method, they differ in their ability to activate the complement system via C3 conversion, the ratio of these activities for CVFm1:CVFm2:CVFk being 2.5:1.6:1. Kinetic studies using a hemolytic test showed that complement depletion by CVFm1 is faster than that by CVFm2. Thus, for the first time the presence in a single venom of two forms of CVF differing by both amino acid sequence and biological activity has been shown.     

Diagnosing vestibular hypofunction: an update

Journal of Neurology - Unilateral or bilateral vestibular hypofunction presents most commonly with symptoms of dizziness or postural imbalance and affects a large population. However, it is often...     

Variability in the Spatial Structure of the Central Loop in Cobra Cytotoxins Revealed by X-ray Analysis and Molecular Modeling

Cobra cytotoxins (CTs) belong to the three-fingered protein family and possess membrane activity. Here, we studied cytotoxin 13 from Naja naja cobra venom (CT13Nn). For the first time, a spatial model of CT13Nn with both “water” and “membrane” conformations of the central loop (loop-2) were determined by X-ray crystallography. The “water” conformation of the loop was frequently observed. It was similar to the structure of loop-2 of numerous CTs, determined by either NMR spectroscopy in aqueous solution, or the X-ray method. The “membrane” conformation is rare one and, to date has only been observed by NMR for a single cytotoxin 1 from N. oxiana (CT1No) in detergent micelle. Both CT13Nn and CT1No are S-type CTs. Membrane-binding of these CTs probably involves an additional step—the conformational transformation of the loop-2. To confirm this suggestion, we conducted molecular dynamics simulations of both CT1No and CT13Nn in the Highly Mimetic Membrane Model of palmitoiloleoylphosphatidylglycerol, starting with their “water” NMR models. We found that the both toxins transform their “water” conformation of loop-2 into the “membrane” one during the insertion process. This supports the hypothesis that the S-type CTs, unlike their P-type counterparts, require conformational adaptation of loop-2 during interaction with lipid membranes.     

Ultrasonic diagnosis of focal damages in thoracoscopic operations

5-year experience of developed in PAMS A.V. Vishnevsky Institute of Surgery RAMS ultrasonic examination (USE) of the lung in thoracoscopic operations for focal lung lesions (FLL) is presented. Pilot experience of ultrasonic topical and differential diagnosis of FII opens a new page in diagnosis of respiratory diseases. Over 5 years 74 USE of FLL were performed. FLL were found in 91% cases. Detailed topical diagnosis of allows to design the lung resection with the best functional result. In postoperative X-ray examination neither atelectases nor zones of stable hypoventilation were detected. Normal echographic picture of lung tissue and echosemiotics of different focal lesions are descubed. The experience of diagnosis by echographic signs of FLL shows teasibility of differentiation of hamartomas from tuberculomas and focal metastatic lesions. The payential of differential diagnosis is illustrated. Differential diagnosis supported enucleation in superficial hamartomas and resection in suspected malignant tumor or tuberculosis. Use of intraoperative USE in the majority of cases of focal lesions located both in depth of lung tissue and subpleurally warrants the success of operation in thoracoscopic variant.     

Endoscopic subfascial dissection of venous perforants in treatment of venous trophic ulcers of the legs

Endoscopic subfascial dissection was performed in patients with chronic venous insufficiency of CEAP class 4-6. 76 surgeries were performed in 68 patients. Mean age of the patients was 56 years. The causes of chronic venous insufficiency were varicose (37) and postthrombotic diseases. Trophic ulcers were in 46 patients. Thirty patients underwent earlier various phlebectomies, including Linton's surgery (6 patients). In 33 patients endoscopic subfascial dissection of venous perforants was combined with various phlebectomy, in 37 patients -- with excision of ulcer with following autodermoplasty few days after surgery. Endoscopic subfascial dissection was carried out with special surgical R.Wolf endoscope with 6 mm instrumental canal, and also standard laparoscopic optical devices "Olympus". Complications during surgery were seen in 2 patients: bleeding in subfascial space (1.3%) and perforation of tissues in ulcer zone (1.3%). In postoperative period long (up to 14 days) lymphorrhea and suppuration of surgical wound were in 2 (2.6%) patients. It is concluded that endoscopic approach is optimal for elimination of pathological reflux through venous perforants in complicated forms of chronic venous insufficiency of the lower extremities, including trophic ulcers resistant to treatment.     

First experience of endoscopic implantation of tissue expanders in plastic and reconstructive surgery

Background: Over the last 15 years, tissue expansion has been used in the treatment of 324 patients at the A. V. Vishnevsky Institute of Surgery. The principal drawbacks of the traditional technique for tissue expansion are the prolonged time needed to complete the process and a high rate of complications. With the traditional technique, the wound created by the implantation of the expander inhibits the expansion of the tissue until healing takes place, which requires 10–14 days. However, attempts to reduce of the length of the incision have been limited by the necessity to ensure good hemostasis in the expander pocket. We describe our initial experience with the endoscopic insertion of tissue expanders. Methods: We performed the endoscopic implantation of 20 tissue expanders in nine patients. Six patients had postburn scar deformities, one had congenital microtia, one had a capillary malformation, and one had a capillary malformation combined with postburn scar deformity. Tissue expanders were inserted in the head, face, neck, chest wall, scapular, shoulder, forearm, and calf regions. The endoscopic technique was specially adapted according to the features of the different anatomic sites. Endoscopy enabled creation of the expander pocket, with good control of hemostasis, through incisions 1 cm. The orientation of these incisions was parallel to forces of tension. Therefore, full expansion began immediately after placement of the expander, without any risk of postoperative wound dehiscence. The expanders were fully inflated intraoperatively accordingly to the principals followed in the traditional technique of implantation for inflation over a 3-week period. Further inflations were carried out regularly either daily or once every other day. Results: The average time required for the tissue expansion was 34 days, which was less than half the time needed with the traditional technique. All flaps remained extant after reconstruction with the expanded tissues. There were no complications. Conclusion: The advantages of the endoscopic implantation of tissue expanders are a reduction in expansion time, a shorter hospital stay, less patient discomfort, and the prevention of complications (hematoma, seroma, infection, wound dehiscence). Presented at the 10th International Congress of the European Association for Endoscopic Surgery (EAES), Lisbon, Portugal, 2–5 June 2002     

Application of chromatography methods for the diagnostics of systemic inflammation

Specific manifestations of systemic inflammation in patients with acute destructive cholecystitis in the postoperative period were studied by the methods of high-precision exclusive liquid chromatography with chromatograph "Trirotar" (Japan) with columns "Polysep G-5", "Toyopearl-Sw - 2000-2500". It was found that systemic inflammation was accompanied by active accumulation of middle- and low-molecular mass. Later their spectrum was found to change when going over to unfavorable clinical course. In patients with septic shock there occurred enrichment of the chromatographic picture spectrum with new peaks (substances which can be considered as endotoxins), decrease of the albumin concentration, as well as increase of dispersity of the biochemical composition of blood.