Porcine splenic peptides (Polyerga) decrease the number of experimental lung metastases in mice.

Preparations of splenic peptides under the name of Polyerga are being tested in numerous experimental immunomodulating and antitumorous models and are also used during supportive treatment of tumorous patients. Further, the incidence of experimental lung metastases of melanoma cells in mice was significantly reduced if we used Polyerga preparations. The aim of our investigation was to determine whether Polyerga is active directly against tumor cells or whether its activity is manifested by modulating immune and other possible abilities of the organism. To clarify the problem glycopeptides containing Polyerga were incubated with melanoma B16F10 cells in vitro and the plating efficiency of these cells determined when cultivated in medium, or in medium with different doses of the same Polyerga preparation. The cells preincubated in medium only reacted to the addition of increasing doses of Polyerga, 150 pg or more, by raising colonies number. However, 24-h incubation of melanoma cells in the presence of 150 micrograms of Polyerga per ml significantly reduced the number of tumor cell colonies in comparison to the corresponding cell cultures previously not exposed to Polyerga. These in vitro studies were extended to in vivo application using C57B1/GoZgr mice injected i.v. with melanoma cells pretreated with Polyerga in vitro or previously not treated. A group of the treated mice was further injected i.p. with Polyerga. All the mice were killed at a particular time and the number of lung nodules determined. A significant difference to the control values was noticed in each group that used Polyerga, regardless of the exposure of melanoma cells to Polyerga in vitro, in vivo or to combined treatment. The efficiency of Polyerga application 7 days following i.v. injection of control melanoma cells (cultivated in medium only) when the nodules already exist, was further evaluated in a combined treatment using DTIC, a drug of choice in melanomas. The smallest incidence of experimental lung metastases was observed in the group exposed to the combination of DTIC and Polyerga. Polyerga preparation is thus active against melanoma cells, particularly in vivo and if combined with chemotherapy.

Proliferation and differentiation of ductular progenitor cells and littoral cells during the regeneration of the rat liver to CCl4/2-AAF injury.

Restoration of centrolobular injury induced by carbon tetrachloride (CCl4), when hepatocyte proliferation is inhibited by treatment with N-2-acetylaminofluorene (AAF), is accomplished by proliferation of ductular progenitor cells, that arise intraportally and extend into the liver lobule. This pattern contrasts to the restitutive proliferation of hepatocytes when AAF is not administered, and the proliferation of non-ductular periportal oval cells follows periportal necrosis induced by allyl alcohol. The expanding ducts stain for alphafetoprotein (AFP), OV-6, pan-cytokeratin (CKPan), and laminin. The neoductular proliferation is accompanied by fibronectin-positive Kupffer cells and desmin-positive stellate (Ito) cells, which may play critical roles not only in controlling proliferation and differentiation of ductular progenitor cells, but also in reestablishing hepatic cord structure. When AAF is discontinued 7 days after injury, clusters of small hepatocytes appear next to the neoductules. Some of these small hepatocytes, as well as some larger hepatocytes adjacent to the ducts, stain for AFP and for carbamoylphosphate synthetase I (CPS-I), suggesting that the ductular progenitor cells may differentiate into hepatocytes when AAF is withdrawn. The restitutive process is facilitated by clearing of the central necrotic zone by infiltrating macrophages and co-migration of mature hepatocytes, with Kupffer cells and stellate cells, into the necrotic zone.

The influence of ethanol addition on the determination of trace elements in aqueous solutions by ICAP.

The effect of the addition of ethanol to aqueous solutions of various trace elements (Ca, Cd, Mg, Cu and Ni) on their spectral line intensities in inductively coupled argon plasma (ICAP) was investigated. Using a relatively low ethanol content (up to 10%, v/v) an enhancement of both atomic and ionic lines was found but to a different extent. By optimization of experimental parameters, an improvement of the sensitivity of the multielemental analysis was obtained.

Matrix effect of barium on spectral line intensities and detection limits in inductively coupled plasma atomic emission spectroscopy.

The effect of four concentrations of Ba (as nitrate) on emission intensities of La(II) 337.7, Mg(I) 285.2, Mg(II) 279.1, Cd(I) 228.8, Cd(II) 226.5, Zn(I) 213.8 and Zn(II) 206.2 nm as a function of power and height above the load coil is studied. The detection limits of atomic and ionic lines of La, Mg, Zn and Cd with/without addition of Ba are reported. Low Ba concentration (0.001M) decreases the detection limit of the element of low ionization energy (La) while high Ba concentration (0.3M) decreases detection limits of the elements of high ionization energies (Cd and Zn) and increases the detection limit of the element of medium ionization energy (Mg).

Antiproliferative activity of some cis-/trans-platinum(II) complexes on HeLa cells.

Purpose of this work was to synthesize several cis-/trans- isomer pairs of the platinum(II) complexes, and study the extent and the mode of their antiproliferative activity on HeLa cells. Six platinum(II) isomer pairs have a general formula cis-/trans-[PtA2X2], where A is ligand: ammonia (NH3), pyridine (Py); and X is ligand: chloride ion (Cl-), bromide ion (Br-), iodide ion (I-), thiocyanato ion (SCN-); four compounds have different structural formulas, and these are cis-/trans-[Pt(NH2OH)2(NH3)2]Cl2, and cis-/trans-Pt(Gly)2, where Gly is bidentate glycinato ligand. Results of the MTT assay, showed that six cis- and one trans-platinum(II) complexes exhibited cytotoxicity (IC50) ranging between 5 and 33 microM. Most of the cis-platinum(II) isomers caused significant alteration of cell cycle phases progression, and induced apoptosis in degree that varied among different compounds, as evaluated using flowcytometry and morphological study. Spectrophotometric analysis (AAS) indicated that there is no correlation between intracellular platinum(II) accumulation and cytotoxicity of tested complexes.

Age-related changes in radiation-induced micronuclei among healthy adults.

The aim of the present study was to establish the extent of in vitro radioresponse of lymphocytes among 62 healthy adults of both genders and to estimate the distribution of baseline micronuclei and radiosensitivity among individuals of the study population using the cytochalasin block micronucleus test. A younger study group consisted of 10 males (mean age, 22.4 years; range, 21-27) and 12 females (mean age, 24.8 years; range, 20-29), whereas an older study group consisted of 18 males (mean age, 35.1 years; range, 30-44) and 22 females (mean age, 38.5 years; range, 30-48). For evaluation of radiosensitivity blood samples were irradiated in vitro using 60Co gamma-ray source. The radiation dose employed was 2 Gy, the dose rate 0.45 Gy/min. The study revealed a significant gender effect on baseline micronuclei favoring females (Z = 3.25, P < 0.001), while yields of radiation-induced micronuclei did not differ significantly (Z = 0.56, P < 0.56) between genders. The distribution of baseline micronuclei among the individuals tested followed Poisson distribution in both study groups and in both genders, whereas the distribution of radiosensitivity among individuals of the older study group did not fulfill Poisson expectations (Kolmogorov-Smirnof test, P < 0.01). In contrast to a nonsignificant difference in radiosensitivity between males and females of the same age group (Z = 1.97, P < 0.56), a statistically significant difference in radiosensitivity between younger and older group for both genders was found (Z = 3.03, P < 0.03). Since the individuals tested were healthy, the observed variability in radiation response is considered to be an early effect of ageing.

Investigation of the system: tri-n-butyl phosphate-n-tetradecane by gas-liquid chromatography.

The interaction of tri-n-butyl phosphate (TBP) with various solutes has been investigated by gas-liquid chromatography (GLC). In the case of benzene and chloroalkane solutes, the formation of 1:1 complexes has been assumed. The nonlinear behaviour of partition coefficients of the solutes with high TBP concentration in an inert solvent (n-tetradecane) has been explained in terms of the dimerization of TBP. Infinite dilution activity coefficients of the solutes and the corresponding excess partial molar functions have also been determined between 25.00 and 50.00 degrees C in increments of 5 degrees C.

Deep medical knowledge to design clinical guidelines.

Guideline-based care is becoming increasingly important given the surging costs and requirement for quality assessment of health care, and is likely to be a major application of knowledge-based technology into the health sector. Our preliminary experiences with implementing a paper-based guideline in a computer have shown problems that may prevent the dissemination and use by clinicians of the computer-based guideline. Based on these experiences, we propose that deep knowledge, often implicit in guidelines specification, is explicitly considered to provide more adequate support and thus promote its acceptability by clinicians.

Knowledge engineering for drug prescribing guidelines.

Prescribing drugs for the treatment of medical conditions is a very common activity for a doctor. Prescribing has enormous economic importance. Costs are rising quickly and there is an urgent need for doctors to have easy assess to advice about the cheapest, most effective therapy. On average 80% of GPs in the UK use a computer for their medical work and the figure is rising rapidly. Currently available systems provide only very simple checks and reminders. More sophisticated advice is provided by our prototype program. The program uses logic engineering to give advice, based on simple protocols for prescribing, tailored both to the condition being treated and the individual patient. The essential logical elements of the prescribing decision are discussed. These simple prescribing protocols may be the final common pathway for prescribing advice from many, more complex protocols for recommendations for drug treatment.

[Inhibition of growth of B16 melanoma caused by liver regeneration]. / Inhibicija rasta melanoma B16 izazvana regeneracijom jetara.

Phenomenon of spontaneous regression of cancer indicates that recovery from malignant disease can happen without the application of any so far known therapeutic treatment. The most of the self-cured patients have undergone surgical operation which did not eliminate entire tumor or did not affect malignant tissue at all. Furthermore, regression or reversion of tumors (transformation of tumor cells into normal, nonmalignant cells) can be achieved in plants or amphibia after exposure of tumor cells to the influence of normal, regenerating tissue. Thus, it seems that during tissue regeneration certain local changes in tissue happen (synthesis of some regulatory growth factors) which induce dying of tumor cells or modify main features of malignant cells. Previously we have studied growth of murine malignant tumors in regenerating tissue of liver and skin. Obtained results indicated that under the influence of regenerating tissue anaplasia of fibrosarcoma decreases, as well as do pigmentation and the incidence of live cells in melanoma B16 tissue. Thus, it is obvious that mechanism of regenerating tissue growth control, which can also change characteristics of tumor cells, exists in mammalia, too. In order to analyse whether the same homeostatic mechanism is responsible for the phenomenon of spontaneous regression of human cancer, we have analysed the growth of melanoma B16 in back limb of nonoperated and sham or partially hepatectomized mice. Regeneration of skin and abdominal wall tissue in sham hepatectomized animals slowed down tumor growth, while liver regeneration completely inhibited tumor progression. Tumor growth inhibition was result of tumor tissue necrosis which developed around blood vessels. However, the structure and integrity of blood vessels themselves was normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Exposure of workers in Tusnica coal mine.

The aim of this paper is to identify potential exposure of the workers in the coal mine Tusnica. The results of the investigation showed increased activity of brown coal up to 1060 ± 88 Bq kg(-1) for (238)U, 976 ± 30 Bq kg(-1) for (226)Ra and 118 ± 31 Bq kg(-1) for (232)Th. Dose rate measurements ranged from 0.07 to 0.25 µSv h(-1). The annual effective dose, taking into account external exposure to ambient gamma radiation and internal exposure due to inhalation of the resuspended dust, would be 1.6 mSv a(-1). The results presented lead to the conclusion that Tusnica coal mine contains brown coal with significant radioactivity, indicating that the working hours in the area should be regulated and the use of respiratory protective equipment is obligatory.

Survey of Vietnamese coffee beans for the presence of ochratoxigenic Aspergilli.

Vietnamese coffee beans were investigated for the presence of ochratoxigenic Aspergilli. Ninety-three percent of the coffee samples studied were positive for A. niger. No other ochratoxigenic species were present. HPLC analysis determined that 8.7% of the A. niger strains were positive for ochratoxin A (OA) production. There was no significant difference in the level of contamination or incidence of toxigenic strains in samples that had been rejected by manual sorting and those that were destined for human consumption. No OA-producing fungi were uncovered in a fresh coffee bean sample analysed, suggesting that the OA problem most likely occurs post-harvest.

Dietary cadmium may enhance the progression of hepatocellular tumors in hepatitis B transgenic mice.

The effect of high cadmium levels in the diet on development of primary hepatocellular carcinomas (PHC) in transgenic mice expressing hepatitis B surface antigen (high expressing lineage 50-4) was determined to test the hypothesis that the incidence of PHC in areas of the world with endemic hepatitis B infections is related to the amount of cadmium in the diet. Groups of transgenic 50-4 mice and non-transgenic litter-mates consumed a diet containing high (5 micrograms/g) or low (< 0.05 micrograms/g) cadmium concentrations ad libitum for up to 20 months. Grossly visible and microscopic changes in the livers were examined at different time points after initiation of the cadmium feeding (3, 6, 9, 14-15 and 18-20 months). Although there was no difference in the incidence of tumors in 50-4 male or female mice fed high or low cadmium diets, male mice fed with high cadmium had more poorly differentiated liver tumors than did low-cadmium fed male mice. These observations suggest that dietary cadmium levels do not affect the number of tumors, but may affect progression of the carcinogenic process leading to development of more poorly differentiated tumors. In addition, after uniform liver dysplasia at 6-13 months in all 50-4 mice, 'remodeling' of large areas of the liver with formation of normal appearing liver cords, admixed with dysplastic and nodular areas, was noted in both male and female aged 50-4 transgenic mice.

[Argyrophilic nucleolar organizers in squamous changes in bronchial epithelium]. / Argirofilni nukleolarni organizatori (AgNOR) u skvamoznim promenama epitela bronha.

Argyrophil technique for presentation of interphase nucleolar organiser regions (AgNOR) is becoming an important method in tumour pathology which is used in diagnosis and prognosis. The number of interphase AgNOR is in the strict correlation with the degree of cell proliferation. We have used this technique in evaluation of degree of differentiation and proliferation of squamous changes of the epithelium of the bronchial mucosa. The statistically significant differences were found (p < 0.01) in the number of AgNOR by nucleus in cells of benignant squamous metaplasia (3.31) and epidermoid bronchial carcinoma (5.34). On the basis of numerical values of AgNOR epidermoid bronchial carcinomas could be divided into the group with low proliferative capability (AgNOR < 5.34) and in the group with high degree of proliferation (AgNOR > 5.34). Prognosis of patients with tumours with the high AgNOR value is poorer and they require additional systemic chemotherapy regardless of the clinical state of the disease at the moment of surgical intervention.

Proliferation of hepatic lineage cells of normal C57BL and interleukin-6 knockout mice after cocaine-induced periportal injury.

The cellular response to periportal liver injury, induced by phenobarbital feeding and cocaine injection, is used to compare the restitutive proliferation of hepatocytes, cholangiocytes, and oval cells in the livers of normal control to those of interleukin-6 (IL-6) knockout mice. After this injury hepatocytes in noninjured middle and central zones start to proliferate first, followed by proliferation of cholangiocytes and intraportal oval cells. Proliferation of all cell types peaks at 2 days, but oval cells continue to proliferate and differentiate through days 4 and 6 as they reconstitute the necrotic zone. By day 10, the injured zone is completely repaired, and no dividing cells remain. During the first 3 to 4 days after injury, the number of proliferating hepatocytes, cholangiocytes, and sinusoidal cells is lower in IL-6 knockout mice than in normal mice, whereas the number of dividing oval cells is higher. However, overall repair of the injury is accomplished in the same time period in both groups. During repair of the periportal zone, oval cells acquire differentiation markers of hepatocytes as they cross the zone of injury. In conclusion, the phenobarbital/cocaine injury model is useful to study restitutive proliferation of mouse liver cell lineages. The proliferative response in IL-6 knockout mice shows that IL-6 is not required for proliferation of liver cells; timely repair of liver injury occurs in both normal and IL-6 knockout mice. Increased proliferation of oval cells in IL-6 knockout mice may compensate for the lower proliferation of other liver cell types.

[Teratogenic tumors of the mediastinum]. / Teratogeni tumori medijastinuma.

Primary teratogen tumors of the mediastinum are rarities in clinical and pathological practice. Their polymorphic histological picture and their enormous size provoke a great diagnostic difficulty. We analyze 85 primary teratogen tumors of the mediastinum (except those that were localized in thymus) which have been diagnosed in Institute for pulmonary diseases and tuberculosis, Clinical center of Serbia, between 1973 and 1991. Material for pathohistological evaluation was obtained by surgical resection of the whole tumor in 58 patients or by percutaneous needle aspiration biopsy in 47 patients. Malignant (immature or teratomas with malignant transformation) were present in 49 (57.65%) patients and benign (mature) teratomas in 36 (42.35%). The majority of benign (mature) teratomas (83.33%) were composed of a variety of tissue elements derived from all three germ layers and 16.67% show only ectodermal and mesodermal derivates. Malignant (immature) teratomas contained both epithelial and mesenchymal incompletely differentiated elements in 67.35% of cases and in 22.45% of cases only epithelial component undergoes malignant transformation. In our series there were two cases of primary seminoma of the mediastinum and one case of primary embryonal carcinoma, primary yolk sac tumor and primary choriocarcinoma of the mediastinum.

Participation of small intraportal stem cells in the restitutive response of the liver to periportal necrosis induced by allyl alcohol.

To determine the involvement of different hepatocyte populations in response to periportal injury, the restitutive response to allyl alcohol (AA) injury was examined. Adult female Sprague-Dawley rats were injected intraperitoneally (IP) with 0.62 mmol/kg AA, killed at 6, 9, 12, 33, 57, 81, and 153 hours after injection, and the livers were examined for injury and for restitutive proliferation by histology, autoradiography, and immunohistochemistry to detect alpha-fetoprotein (AFP), glutathione-s-transferase-p (GST-p), desmin, leukocyte common antigen, albumin, and monoclonal antibodies to liver cells: OV-6, H-4, and T-6. AA produces variable periportal liver necrosis predominantly at 6 to 12 hours. Proliferation of hepatocytes throughout the hepatic cord is seen early after injury in nonnecrotic areas: predominantly in zone II, but also in zones I and III, including some cells adjacent to the central vein. Within 2 to 3 days the necrotic zones are filled with small cells and by 1 week the liver architecture is essentially restored. During the active restitutive reaction from the immediate periportal rim the following cell phenotypes are seen: null cells: -->(AFP+, OV-6-, GST-p-) cells-->(AFP-, OV-6+, GST-p+) cells-->large (AFP-, OV-6-, GST-p-, H-4+) liver cells. Albumin staining was negative. We conclude that restitutive proliferation of periportal necrosis induced by AA appears to be accomplished by proliferation of intraportal (?stem) cells whose progeny differentiate and eventually repopulate the necrotic zone.

Cell kinetics of repair after allyl alcohol-induced liver necrosis in mice.

The cellular kinetics of repair and scarring which occurs after induction of periportal necrosis in mice by allyl alcohol were examined by histology and immunohistochemistry. Thirty-six six-week-old female C57BI/6J mice were injected intraperitoneally with two doses of allyl alcohol on day 0 and tissue sections were taken at various times and stained by haematoxylin and eosin or immunostained for proliferating cell nuclear antigen (PCNA), bile duct/oval cell marker A-6, and DNA fragments (apoptosis). Within 6 hours, periportal necrosis was seen extending to produce large zones of confluent, pan-acinar irregular necrosis, predominantly in the right and medial lobes with sparing of the left and caudate lobes. Restoration of liver mass was accomplished mainly by proliferation of mature hepatocytes in the surviving lobes of the liver (hyperplasia). In the right and medial lobes where necrosis was limited to the periportal zone, there was some, but much less, proliferation of small, oval periportal cells. The large necrotic zones in the right and median lobes shrank and were replaced by granulomatous inflammation. This cellular contribution of liver regeneration in the mouse was different from that previously reported in the rat and provides a means of inducing only a small proliferation of oval cells.

Antitumorous and immunomodulatory effects of the Viscum album L. preparation Isorel.

There are numerous data on the immunostimulative and antitumorous activity of various Viscum album tissue extracts. Isorel (Novipharm, Austria) is one of these compounds. We found that in mice an increased number of plaque-forming cells to sheep red blood cells (SRBC) followed the injection of Isorel together with SRBC. Further, survival time of a foreign skin graft was shortened if Isorel was applied at the correct time. Finally, suppressed immune reactivity in tumorous mice recovered following Isorel injection. Isorel was further shown to be cytotoxic to tumor cells in vitro. Its application to tumor-bearing mice could prolong their life but without any therapeutic effect. However, a combination of local irradiation and Isorel was very effective: following 43 Gy of local irradiation to a transplanted methylcholanthrene-induced fibrosarcoma (volume about 240 mm3) growing in syngeneic CBA/HZgr mice, the tumor disappeared in about 25% of the animals; the addition of Isorel increased the incidence of cured animals to over 65%. The combined action of Isorel, influencing tumor viability on the one hand and the host's immune reactivity on the other, seems to be favorable for its antitumor action in vivo.