[Radiofrequency ablation of hepatic metastases: clinical results].

AIM: To establish the effectiveness of radiofrequency ablation in the treatment of metastatic hepatic lesions. PATIENTS AND METHODS: 104 pts with 231 metastases were treated with RFA. The volume of achieved destruction was assessed using imaging method and cytology. Patients were followed-up for 1-37 months. RESULTS: 87.3% of metastases < 3.0 cm, 50.9% of tumors sized 3.0-5.0 cm and 14.3% of metastases > 5.0 cm were completely destroyed. Major complications occurred in 7.5% of the patients. 34% of the ablated tumors recurred. CONCLUSIONS: The effectiveness of RFA metastases depends on the size and location of the lesion. Lesions adjacent to the gallblader and main bile ducts are risky for manipulation.

[Bolus percutaneous ethanol injections in hepatocellular carcinoma--clinical results].

AIM: To establish the effectiveness of large-volume percutaneous ethanol injection under general anesthesia (Shot-PEI) as a local method for destruction of large hepatocellular carcinoma (HCC). PATIENTS AND METHODS: 46 patients with 48 HCC were treated with Shot-PEI. 1-4 sessions per lesion were performed with 12-138 ml ethanol per session. RESULTS: Complete destruction was achieved in 43.8% of the tumors. Major complications occurred in 10.9% of the patients. Local recurrences were 19%. CONCLUSION: Shot-PEI is an effective method for destruction of large tumors and multiplies the therapeutic options in HCC.

[Radiofrequency ablation of recurrent intrahepatic cholangiocarcinoma: a case report].

A 45-years-old patient with recurrent intrahepatic cholangiocarcinoma 3 years after resection is described. 2 sessions of percutaneous radiofrequency ablation (RFA) were performed and complete destruction of the tumor was achieved. The patient was followed-up for 15 months by means of power-Doppler, CT and tumor markers. No local or heterotopic recurrences were observed. The case demonstrates the possibilities of RFA in the management of postoperative recurrences of intrahepatic cholangiocarcinoma and confirms the significance of the method in the complex approach to the liver tumors.

[Percutaneous puncture treatment of hepatic cystic echinococcosis under ultrasound guidance]. / Perkutanno punktsionno lechenie na kistichnata chernodrobna ekhinokokoza pod UZ kontrol.

Introducing of the alternative PAIR (puncture-aspiration-injection-reaspiration) method for treatment of hepatic echinococcosis in practice dates from 1992 year. A Working group dealing with the problems and standardization of the method has been created by WHO. The major aspects of this treatment are summarized in the bulletin of WHO of 1996 year. On the last World Congress of Ultrasound, held in Florence, Italy in 1999 this method was reported as safe and effective treatment modality. The necessity for further prospective studies was also emphasized. The aim of the Working group for performing of PAIR, created at the Clinical Centre of Gastroenterology, University Hospital "Queen Joanna" in 1999 is to report the preliminary results and declare the possibilities for its application. Nine patients (6 males, 3 females) with 11 cysts (I, II and IIIa types after Gharbi) measured 3-9 cm were punctured and followed up for a 6 months period. 95% ethanol was used as protoscolicidal agent with concomitant preventive oral treatment with Mebendazole. No serious complications were observed. In all patients separation of the germinative membrane was verified. 2/5 cysts < 3.5 cm completely disappeared, 7/11 diminished their size without signs of vitality, while 2/11 remained vital. One ofe the cysts had a biliary communication which necessitated the injection of 20% NaCl instead of ethanol. The serological ritres significantly decreased in all patients. The risk of anaphylaxis and seeding is negligible while keeping the technique of PAIR precisely. The PAIR treatment of hepatic echinococcosis presents great progress with its safety, low risk and excellent therapeutic results.

[The diagnostic approach in hepatic lesions--the role and place of laparoscopy with laparoscopic echography]. / Diagnostichen podkhod pri chernodrobnite lezii--rolia i miasto na laparoskopiiata s laparoskopska ekhografiia.

The study is designed to cases the potentials of laparoscopy with laparoscopic echography, and the role they play in the diagnostic algorithm, with the purpose to develop an optimal therapeutic approach to hepatic lesions. Laparoscope R. Wolf and 7.5 MHz linear transducer, obtained from the Aloka Company are employed in work. A total of 303 patients presenting primary and metastatic carcinoma of liver (58 and 145, respectively), cholangiocarcinoma (11), hemangioma(28), adenomatous hyperplasia (38) and other lesions (23) are studied. Morphologic verification of the diagnosis is done in over one third of cases. In 30 to 40 per cent of the series reviewed laparoscopic echography supplements the laparoscopic finding depending on the type of lesion. Without pretending to create a diagnostic algorithm in individual hepatic lesions, abiding to the following diagnostic approach is strongly recommended: stage one--echography (a noninvasive, not irradiating, cheap, readily accessible and often resolving method), stage two--noninvasive, stage three--invasive, stage four--preoperative or final (laparoscopy plus laparoscopic echography). In the event of properly established indications, the invasive methods of study (thin-needle biopsy under ultrasonographic control plus laparoscopy) may be considered as a second stage, without any need to apply the complete spectrum of examination accessible. Not infrequently, laparoscopy with laparoscopic ultrasonography play a crucial role in diagnosing liver lesions, exact determination of the stage and resectability of the neoplastic process, planning and shortening the duration of operation with simultaneous identification of intractable patients.

[Isolation of lymphocyte cultures from leukemic cattle and electron microscopic study of the leukemia virus]. / Poluchavane na limfotsitni kulturi ot bolni ot levkoza goveda na elektronnomikroskopsko prouchvane na virusa na levkozata.

Several methods were employed to obtain lymphocyte cultures from blood samples taken from normal cattle and from cattle affected with enzootic leukosis. Biologic and virologic experiments revealed that the cultures from diseased cattle contained an oncogenic leukosis virus, while those obtained from healthy animals were exempt from such virus. Electron microscopy was applied to study the morphologic aspects of the bovine leukosis virus with a total of 18 lymphocyte cultures. The viral particles noted were shown to have typical configuration and size of type C oncogenic viruses as described in the literature--possessing a central dense nucleotide and double membranes. Seen were also various stages in the development of the virus. Mature virus particles were likewise observed in a stable cell line FLK (percent of the virus) as well as in ultrathin cross sections of the spleen of leukosis-affected animals.

[New trends in the control of enzootic bovine leukemia in Bulgaria]. / Novi nasoki v borbata s enzootichnata levkoza po govedata u nas.

Experimental and literature data as well as personal observations with herds infected with enzootic bovine leukosis have revealed some new aspects that could be made use of in the control of the disease. The more important ones are stated: newborn calves of cows with positive leukosis response can be given untreated colostrum which has been shown to neutralize the virus; in individual regions and Agro-Industrial Complexes where sporadic cases of leukosis have been recorded isolation premises for positively reacting animals could be designed; cows in the last two months of pregnancy do not always give reliable results with the immunodiffusion test, so such animals should not be investigated at that time with this method.

[Role of vertical transmission and seminal fluid in the infectious leukemia process]. / Roliata na vertikalnoto predavane i semennata technost pri levkozniia infektsiozen protses.

Studied was the occasional role played by vertical transmission of the leukotic infection via the placenta under experimental conditions and in the field. Studies were also carried out to establish the transmission of the infection through the semen as well, using bull semen and test lambs as most susceptible to the virus of bovine leukosis. It was found that at the experimental infection of sheep with the bovine leukosis virus intraplacental infection of part of the fetuses took place. On dairy farms with a widely spread infection (more than 50 per cent) in cattle the newborn calves were found to respond positively immediately after birth and prior to sucking colostrum, having specific leukosis antibodies, though in a low percent. No transmission of leukosis was found with the semen of leujotic bulls.

[Importance of saliva and colostrum in leukemia transmission in cattle]. / Znachenieto na sliunkata i kolastrata pri predavane na levkozata u govedata.

Studied was the occasional role played by the saliva of leukotic cows in the transmission of the infection to test lambs along with the role of colostrum as a factor neutralizing the leukosis virus in experimentally infected lambs. It was found that bovine leukosis could be transmitted by the saliva of affected animals. Colostrum that contained hightiter specific antibodies was found to be effective in neutralizing the leukosis virus in newborn calves provided no subsidiary infection took place.

[Combined method (suspension-monolayer) of preparing an inactivated foot-and-mouth disease vaccine]. / Izgotviane na inaktivirana protivoshapna vaksina po kombiniran metod (suspenziia-monosloi).

Semiproductional and productional experiments were carried out to cultivate BHK21C13 cells in 30- and 250-litre fermentors, to produce F.M.D. virus in suspension and in roller, and to produce a F.M.D. vaccine in 500-litre automatic mixing containers, employing a combined method 'suspension-monolayer'. The F.M.D. virus that was replicated in suspension had a 10(-6,0-6,5) titer, and the virus that was obtained in monolayer - a 10(-7,0-8,0) titer. It was demonstrated that the F.M.D. vaccines that were produced after the combined method were sterile, innocuous, and immunogenic.

[Specific immunoprophylaxis trials with calves against foot-and-mouth disease]. / Opiti za spetsifichna imunoprofilaktika na teletata sreshtu shap.

Studies were conducted on vaccination of different age groups of calves with monovalent and biovalent vaccine against foot-and-mouth disease using various immunization patterns. The studies showed that passive immunity of calves impedes the building up of solid immunity. It is recommended on the basis of comparative studies of different immunization schemes to vaccinate calves under 6 months of age with double vaccine dose and to revaccinate them 1--2 months later. It was shown that calves aged 6 to 12 months react to vaccine against foot-and-mouth disease as adult animals but revaccination is also recommended to build up solid immunity. The influence is discussed of various factors hindering the building up of solid post vaccination immunity in young animals following vaccination with vaccine against foot-and-mouth disease.

[Laboratory trials of culturing BHK 21 C 13 cells in a roller using an enzymatic egg hydrolysate-based nutrient medium]. / Laboratorni opiti po kultivirane na kletki BHK 21 C 13 v roler pri izpolzvane na khranitelna sreda na baza iaichen enzimatichen khidrolizat.

Experiments were carried out to find the optimal conditions for the replication of BHK 21 C 13 cells in one 1 roller glassware with the use of a nutrient medium containing products of the enzymatic breakdown of white of egg. Studied was the sensitivity of these cells to the type C strain 'Hungary' of the foot-and-mouth disease virus. Two series of F. M. D. vaccines were produced, which proved to be sterile and innocuous for guinea pigs. Immunogenicity trials with regard to these animals revealed that the VD50 (vaccinal dose) values ranged from 0.12 to 0.26 cm3.

[Experiments to obtain and use an allergen for the diagnosis of leukemia in animals]. / Opiti za poluchavane i prilozhenie na alergen za diagnostika na levkozata po zhivotnite.

The tested allergen was obtained from a stable cell line FLK which produces leukosis virus type "C" for diagnostics of animal leukosis (cattle, sheep, pigs). It was found that the allergen is strictly specific and induces hypersensitivity of delayed type which is recorded best on the 24th h of injection. The most suitable site to inject the allergen proved to be the tail fold for cattle and sheep and the dorsal part of the ear--for pigs in dose of 0.2 cc. The allergen reaction correlates to a considerable degree with the serologic one (AGDS) but it does not detect all serologic reagents. It detects much larger percent of susceptible animal compared with the hematologic method. Data obtained give grounds to assume that the allergen reaction may be used for quick herd diagnostics of leukosis.

[Production and use of a nutrient medium with egg hydrolysate for monolayer reproduction of BHK 21/13 cells]. / Poluchavane i izpolzvane na khranitelna sreda s iaichen khidrolizat za monosloino razmnozhavane na kletki BHK 21/13.

Experiments aiming to reproduce BHK 21/13 cells in Roux retorts by use of a semi-synthetic nutrient medium, based on protein hydrolyzate synthetized by the authors, were carried out. Results obtained show that the lower peptides and free amino acids found in ovarian hydrolizate meet the requirements of the cell line in respect to quality and quantity. The successfull cultivation of BHK 21/13 cells in hydrolyzate medium made possible a considerable reduction in the percentage involvement of serum, which is usually used in the classical nutrient media of the type Eagle BME intended for the propagation of diploid cell strains.

[Study and identification of the respiratory syncytial virus isolated from a leukemic cow]. / Prouchvanie i identifitsirane na respiratorno-sintsitialen virus, izoliran ot levkemichno bolna krava.

A virus was isolated from the lymph nodes of a cow. By its cultural, physical, chemical, and biologic properties it proved identical with the standard bovine respiratory syncytial virus. It multiplied well in cell cultures of calf kidney at pH 7--7.5. Introduced in 20-day-old guinea pigs the virus caused anorexia, bristling up of hairs, stunting, and occasionally death. The inoculated guinea pigs developed pneumonia of a proliferative type with Langhans' giant cells. The interrlationship between the isolated virus and the standard oncorna virus, type C, is discussed.