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Biomedical subjects

H F Nowak

Publications and source records attributed to H F Nowak.

At least 37 records · Page 2Linked to original sources
PubMed1996

Ultrastructural analysis of pulmonary capillaries in the course of experimental lung emphysema.

Processes which occur within the capillaries of interalveolar septa play a major role in many lung diseases. In the present study, ultrastructural analysis of pulmonary capillaries was made at 7 days after intratracheal instillation of a proteolytic enzyme - papain, that is when macrophage cumulation within pulmonary tissue was maximal. Experimental animals (male Wistar rats) were injected with BCG vaccine, in doses that would stimulate the macrophage system to produce TNF-alpha. All the experimental groups, compared with the control, showed cumulation and increased adherence of monocytes, granulocytes and blood platelets to endothelium. Changes within endothelial cells manifesting their activation were observed. In the animals receiving papain or BCG, focal destruction of endothelial cells was found. The picture of vascular changes induced with papain and by simultaneous stimulation with BCG vaccine revealed a number of features similar to those found in the adult respiratory distress syndrome. The study proved usefulness of vascular perfusion as a method to analyze the vascular system, particularly in the processes progressing with activation and increased adhesion of inflammatory cells to the endothelium of pulmonary capillaries.

Animals↗
PubMed1996

The effect of local hrec TNF-alpha administration upon the spontaneous lung metastases in rats with Morris 5123 hepatoma.

The experiment used Morris hepatoma 5123 series growing in muscles of the right hind limb of Buffalo rats. The group I animals were given intratumor 4 doses of TNF-alpha and group II-8 doses of TNF-alpha (10 micrograms/day). Control groups (III and IV) consisted of rats with injected Morris hepatoma, which were given PBS solution instead of TNF-alpha. A decrease in the volume of neoplastic metastases was observed in groups I and II, compared with groups III and IV. At the same time an increase was found in the volume of metastatic tumors in group II (8 x TNF-alpha), compared with group I (4 x TNF-alpha). Histological and ultrastructural analysis of the pulmonary tissue revealed intensified fibrotic reactions and inflammatory infiltrations around the metastatic tumors. The change were much more enhanced in group II, which might affect the results of neoplastic metastatic volume measurements. We concluded that multiple human recombinant TNF-alpha, hrec TNF-alpha, local injections inhibited dissemination of tumor cells and prolonged the survival time of rats up to the 76th day of the follow-up.

Animals↗
PubMed1995

Inhibitory effect of the human recombinant tumor necrosis factor on the growth of the Morris hepatoma in rats.

The effect of the human recombinant tumor necrosis factor alpha (h rec TNF-alpha) on the transplantable Morris hepatoma 5123 was studied in Buffalo rats. The cytokine was repeatedly administered intratumorly (i.t.) in a dose of 1.5 x 10(4) U once a day in a cycle of four and eight days. The control groups consisted of animals given saline i.t. The experiments revealed an inhibitory effect of the h rec TNF-alpha upon the growth of neoplastic tumors. The biometric parameters of the tumors indicated that the inhibition of the Morris hepatoma was most effective after eight repeated doses of TNF. After injections of TNF-alpha, the tumors presented extensive hemorrhagic necrosis, the regressive alterations being found mainly in the central and intermediate tumor zones. In the early phase of the tumor growth, neoplastic tissue necrosis prevailed, as well as hemorrhages within the necrotic masses, necrosis of the blood vessel walls and thrombi in their lumina. In the later period, numerous fibres of the fibrous tissue, richly vascularized, occurred in the peripheral and intermediate zones. Clusters of eosinophilic granulocytes and macrophages with apoptotic bodies in the cytoplasm were seen on the border of the necrotic foci.

Animals↗
PubMed1995

Evaluation of biometric parameters of Morris hepatoma after application of human recombinant tumor necrosis factor.

The effect of human recombinant tumor necrosis factor alpha (h rec TNF-alpha) on the growth of Morris hepatoma 5123 implanted in the skeletal muscles of the thigh of Buffalo rats was investigated. The cytokine was repeatedly given in an intratumor administration (i.t.) in dose of 1.5 x 10(4) U once a day in regimens of four or eight days. Comparative groups consisted of animals which were given saline i.t. Control groups included healthy rats subjected to local cytokine effect. The experiments revealed an inhibitory effects of the preparation on the growth of tumors. Biometric parameters of the tumors induced indicated that the inhibition of Morris hepatoma was most effective after the eighth dose of h rec TNF-alpha. The administration of fourfold dose resulted in an initial loss of body mass increase. However, when injected eight times, the factor produced a relative tolerance reflected in minor reduction of actual body mass. The estimation of survival time in rats injected i.t. with h rec TNF-alpha, compared to those given saline, revealed statistically significant differences at the eighth repeated dose.

Animals↗
PubMed1995

The effect of activated alveolar macrophages on experimental lung emphysema development. III. Morphological analysis of the lung tissue and alveolar macrophages in situ.

Morphological (in light and transmission electron microscope) as well as morphometrical analysis of the lungs was performed on experimental, papain-induced lung emphysema. Development of emphysematous changes was studied seven days after a single intratracheal instillation of papain solution. The effect of alveolar macrophages (AM) activation by BCG-vaccine on changes in pulmonary tissue was analyzed. In the rats given BCG the number of AM increased and demonstrated enhanced activity. Increase in reticulin fibre density in places of AM cumulation, particularly in BCG+papain-treated rats was observed. The lungs of animals treated with BCG+papain showed enhancing of emphysema comparing with the papain-treated rats. Development of emphysematous changes, especially in BCG+papain-treated rats coexisted with cumulation of activated alveolar macrophages and collagen fibres as well as type II alveolar epithelial cells proliferation. Our data support the inflammatory-repair hypothesis of emphysema pathogenesis and indicate that AM regulate collagen production in the lung. Type II alveolar epithelial cells seem be important in lung injury and repair.

Animals↗
PubMed1994

Alveolar epithelial cells in experimental lung emphysema. Ultrastructural analysis of cells in situ in TEM.

A study was made of ultrastructural changes in alveolar epithelial cells after a single intratracheal papain injection. The experiment was carried out on male Wistar rats, of 180-220 g body weight. The animals were sacrificed after 1, 7, 14 and 28 days that followed proteolytic enzyme administration. The study revealed that the development of emphysematous changes in the rat lungs was accompanied by alterations in the epithelium of alveoli. In early stages of emphysema (up to 1 week), destructing changes dominated within the epithelial cells. Similar changes were observed in the endothelium of adjacent blood vessels. In later periods an increased number of type II pneumocytes were seen and focal accumulation of elastic and collagenic fibres was noticed in alveolar septa. Correlation was found between changes in the number of type II cells and their ultrastructure as well as between alveolar epithelium damage and alveolar septal interstitium alterations.

Animals↗
PubMed1994

Alveolar epithelial cells in experimental lung emphysema. Analysis of methods for type II pneumocyte identification among cells isolated from the respiratory tract of rats.

Total and differential counts of cells isolated from the lungs of Wistar rats with experimental emphysema were performed. Emphysema was induced by a single intratracheal dose of papain solution (20 mg/kg b.w.). Rats were sacrificed 1, 7, 14 and 28 days later. Cells were isolated from the lungs through multiple bronchoalveolar lavage. An attempt to identify type II pneumocytes was undertaken. Our observations suggest that none of the methods applied for identification of type II pneumocytes are completely specific. At the same time they stain type II cells and subpopulations of alveolar macrophages heavily loaded with phagocytized surfactant elements. However those methods are simple and enable an approximate evaluation of damage and regeneration processes in the extracellular alveolar lining layer and epithelium.

Animals↗
PubMed1993

[The effect of pentoxifylline on the degree of lung parenchyma injury after papain].

In the last years pentoxifylline (PTXF) has been successfully used in reducing acute injury of the lung parenchyma in ARDS. The authors have studied the effect of PTXF on degree of papain induced lung injury. Papain was administered intratracheally in a dose of 2 mg, 4 mg, 6 mg in 1 ml of PBS. The effect of papain on bronchoalveolar lavage characteristics was also evaluated. Wistar rats of both sexes were used in the experiment. The degree of lung destruction, reflected by interstitial hemorrhage was assessed by measuring hemoglobin content in the fluid of the lavaged lungs. The hemoglobin levels were assessed spectrofluorometrically with the use of the 414 nm wave length. A reduction of hemoglobin content was seen after PTXF administration only in animals receiving the lowest dosage of papain. However in all animals a decrease in the BAL neutrophil count was demonstrated. The protective effect of PTXF on pulmonary tissue in papain induced injury models and situations leading to development of ARDS may suggest a similar pathomechanism in both entities.

Animals↗
PubMed1993

[Pulmonary thromboembolism--random analysis of autopsy material].

In the study an analysis of 13216 autopsy materials was performed to evaluate a frequency of pulmonary thromboembolism incidence including localisation of detected changes. Pulmonary thromboembolism was determined in 5.5% autopsies, with evident increase in older subjects (up to 31.3% in 70-79 years old group). The most frequently (67.8%) pulmonary thromboembolism was observed in lobar and segmental arteries in a course of atherosclerosis (28.6%), neoplasmas (20.8%) and septic diseases (15.5%). In 25% cases of pulmonary thromboembolism has been diagnosed during clinical observations and has been confirmed by autopsy procedure.

Adolescent↗
PubMed1991

[Morphological changes of bone marrow in patients with bronchial and gastrointestinal carcinoma and hematological abnormalities in peripheral blood].

The authors carried out the morphological and clinical analysis of 200 cases patients suffering from carcinoma but not treated (104 cases of carcinoma of the bronchus, 30 cases of the stomach, 26 cases of the pancreas, 24 cases of the liver and gallbladder and 16 cases of the large intestine) and have estimated the hematological and bone marrow abnormalities. Most frequently occurring hematological changes in this group were: anaemia (28.5%), thrombocytopenia (22.4%), clinical symptoms of thrombosis (22.0%) and changes of bone marrow: sclerosis (42.5%), neoplastic metastases (30.0%), and atrophy (27.5%). In the examined cases the authors have not found any particular connection between the kind of hematological abnormalities and the kind of morphological changes of the bone marrow. The most common changes in the bone marrow which accompanied hematological abnormalities were neoplastic metastases and atrophy of the marrow especially in cases with anaemia and thrombocytopenia.

Adult↗
PubMed1990

[Morphological studies of the effects of protein-free diet and branched-chain amino acids (aminosteril-hepa (Frasenius)) on experimental thioacetamide-induced liver damage].

The studies were performed in two groups of rats in which experimental hepatic encephalopathy was induced with tioacetamide++. One group of rats on protein-free diet was given intraperitoneally a mixture of amino-acids (Aminosteril-Hepa), the other one was given proteins in the diet in a dose 1 g per kg of body weight. Histological and histochemical studies revealed that free-protein diet with a mixture of aliphatic polybranched amino-acids (Aminosteril-Hepa) inhibited hepatotoxic thioacetamide+ action on the rat liver.

Amino Acids↗
PubMed1990

[Effect of differentiated diet therapy on the clinical results and biochemical indicators in chronic hepatic encephalopathy].

Effects of differentiated diet with reduced proteins or diet without proteins with simultaneous use of lactulose or the preparation enriched with aliphatic amino acids with aminosteril-hepa chain on the clinical results and the ammonia, phenols, alpha-amino nitrogen, tyrosine, phenylalanine and tryptophan++ concentrations in the serum have been studied. It has been demonstrated that limitations of proteins in the diet or diet without proteins with the use of lactulose or amino acids mixtures above does not influence significantly the clinical amelioration or biochemical indices of encephalopathy or coma during the liver cirrhosis course. Homogenates of the liver and brain of patients who died due to encephalopathy and liver cirrhosis showed high contents of ammonia, tyrosine, phenylalanine and tryptophan++.

Amino Acids↗
PubMed1989

[Sclerosis and fibrosis of the bone marrow in lung and gastrointestinal tract cancers].

The authors analyzed the incidence of pathologic lesions of the bone marrow in the form of sclerosis and fibrosis in patients with lung and gastrointestinal tract (gastric, pancreatic, hepatic and bile duct) carcinomas. In the analysis of argentaffin and collagen fibres in the bone marrow we used Kundel's score modified by Bauermeister. The results obtained in the studied group were compared with the bone marrow of persons without neoplastic diseases and other disorders that might have affected the bone marrow. It was found that in patients with neoplastic disease and fibrosis of the bone marrow were quite frequent disturbances.

Aged↗
PubMed1989

[Pulmonary bone marrow embolism in nonselected autopsy material].

We analyzed the incidence of bone marrow emboli of the pulmonary arteries in nonselected autopsy material involving 620 cases. We evaluated the incidence of these emboli, age, sex, underlying disease and microscopic picture. It was found that bone marrow emboli of the pulmonary arteries occurred in 7% of cases, most frequently in patients aged from 50 to 69 years and they were located in the medium and small-lumen arteries. It was found that bone marrow emboli of the pulmonary arteries may complicate posttraumatic bone fractures, costal and sternal fractures in the course of reanimation as well as malignant neoplasms and shock.

Adult↗
PubMed1986

[Histopathologic and biochemical evaluation of the effect of cortisone on the liver in experimental post-alcoholic liver damage in the rabbit].

Possible protective effects of cortisone in experimental post-alcohol liver damage were evaluated in relation to dose and duration of treatment. Model examinations were undertaken in 100 rabbits divided into groups of 10. No protective effect of cortisone could be demonstrated. Treatment did not alter biochemical indices of liver function. Histologic examination revealed somewhat less extensive fatty changes following chronic alcohol exposure in animals receiving 1 mg cortisone per kilogram body weight.

Alanine Transaminase↗
PubMed1985

[Chronic pancreatitis as a predisposing factor in the development of pancreatic cancer. Histological and histochemical studies].

The frequency of hyperplasia, squamous metaplasia and dysplasia were examined in glandular tissue from 20 pancreatic specimens resected due to chronic inflammation. Hyperplasia of the epithelium of large pancreatic ducts with formation of papillomatous outgrowths was present in 6 cases. Epithelial hyperplasia of small ducts occurred in 10 cases. Dysplasia and squamous metaplasia of the epithelium of ducts, hypertrophy, hyperplasia and dysplasia of acinar cells were found in 7 cases. In 10 pancreatic specimens hypertrophy and hyperplasia of cells of the islets of Langerhans were noted. Increased histochemical reactions to dehydrogenases and proteinic thiol groups were present in epithelial cells which demonstrated hypertrophy, hyperplasia, metaplasia or dysplasia. Diminution of the PAS reaction to neutral glycoproteins and intensification of the reaction to acid glycoproteins were also noted in the ductal epithelium. The results obtained suggest that chronic inflammation of the pancreas should be clinically regarded as predisposing to the development of pancreatic cancer.

Adult↗
PubMed1985

[Effect of alcohol on the development of biochemical and morphologic findings of liver damage in the rabbit].

Ethanol 48% was applied to the experimental model in 3 examined groups of rabbits in different periods of administration and differentiated daily doses on order to investigate the influence of ethanol upon the formation of morphological and biochemical indices of the liver lesion. Biochemical investigations were carried out on 3 and 7 day of the experiment and repeated at week by intervalls. All the animals were dissected and morphological examinations of the liver were carried out. Total analysis of the results obtained of the biochemical and morphological examinations of the liver in 3 analysed groups of animals proved that the biochemical index of postalcoholic lesion of the liver was a rise in guanase activity, and not in activity aminotransferases. In the investigations of fat balance, however the increase of triglycerides and cholesterol was observed. Morphological examinations showed post-alcoholic lesions of the liver, especially intensified in animals under longlasting alcohol influence, but in reducted doses.

Alanine Transaminase↗