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Biomedical subjects

C J Kirkpatrick

Publications and source records attributed to C J Kirkpatrick.

At least 127 records · Page 7Linked to original sources
PubMed1991

Characterization of the new bladder cancer cell line HOK-1: expression of transitional, squamous and glandular differentiation patterns.

The new continuous cell line HOK-1 derived from a grade-III transitional-cell bladder carcinoma with foci of squamous and glandular differentiation was shown to retain this phenotypical heterogeneity for more than 45 passages in vitro. Electron microscopy revealed transitional as well as a considerable proportion of squamous carcinoma and adenocarcinoma cells. PAS-positive mucus was detected in numerous cells. These features were principally maintained when grown as multicellular spheroids and in nude mice. More pronounced signs of differentiation (i.e., expression of cytokeratins 10 and 11, formation of glandular structures) were found in xenograft tumours. Independently, cytokeratins 13, 18 and 19 were detected in vitro and in vivo, reflecting the urothelial origin. The line forms distinct colonies in soft agar, expresses Lewis-x and Lewis-y antigens and reacts with monoclonal antibodies (MAbs) against CEA, beta-HCG and URO-5. Cytogenetic analysis revealed several related clones with a rearrangement at chromosome 1 and loss of one X chromosome as common karyotypic changes in all clones. DNA content, as quantified by image analysis, showed a DNA stemline close to 2c. The new cell line HOK-1 can be used as an in vitro model to study the mechanisms of heterogeneous differentiation patterns in bladder cancer.

Aged↗
PubMed1991

Anatomic nature and surgical significance of anal sinus and anal intramuscular glands.

The nature of anal sinus and anal intramuscular glands is well known, but their origin is still discussed. In the past years a surprising new theory about the invagination of the proctodeum into the hindgut was put forward. Evidence supporting this theory would be the existence of an "anorectal band" and "epithelial debris" in the subanoderm formed during total or partial obliteration of the anal sinuses. To characterize these histological structures, the authors examined 62 autopsy specimens with conventional and special immunohistologic staining methods. In none of the examined specimens could the structures mentioned above be detected. Nearly 90 percent of our specimens contained the well known anal sinuses. In fetuses, neonatal deaths, and children, more than one-half of the anal sinuses were accompanied by anal intramuscular glands penetrating the internal anal sphincter, whereas in adult specimens the anal intramuscular glands were rare. Eight postoperative, idiopathic chronic anal fissures and three postoperative anal fistulas examined with the same staining procedures showed epithelial cells at the base of the fissures or fistulas in two cases (25 percent) and three cases (100 percent), respectively. The results reinforce the theory that anal sinuses and anal intramuscular glands are separate anatomic entities and indicate a new theory of anal development. For idiopathic, chronic anal diseases anal sinuses have little surgical significance. Anal intramuscular glands should be the anatomic correlate of anal fistulas.

Adolescent↗
PubMed1991

Fibrinogen degradation product-D, fibrinogen, and serum change polymorphonuclear granulocyte activity--possibly important post-trauma?

Severe trauma favors the susceptibility of patients to infection. It has been shown that proteins or protein fragments are responsible for an endogenous immunodepression. After trauma a coagulopathy accompanied by increased serum levels of fibrinogen degradation products (FDP) is often found. Therefore, we examined whether FDP-D can influence the activity of polymorphonuclear neutrophils (PMN). PMN-activation was measured by two different superoxide-specific methods (Cytochrome-C-test, INT-test). With both methods we found a decrease of PMN activity by FDP-D compared to fibrinogen. Albumin, which was used as a control protein, only influenced PMN activity in unphysiologically high concentrations. The third method used to quantify PMN activity was chemiluminescence, which is a more unspecific method since it is developed not only by oxygen radical species but also by activating the lipoxygenase pathway. In contrast to the superoxide specific tests we found an inhibitory effect of fibrinogen and also serum compared to FDP-D using chemiluminescence.

Cytochrome c Group↗
PubMed1991

Effect of fibrinogen fragments D and E on the adhesive properties of human granulocytes to venous endothelial cells.

In hyperfibrinolytic conditions, e.g. in disseminated intravascular coagulation or the adult respiratory distress syndrome, high levels of fibrinogen degradation products (FDPs) D and E are found in human plasma. This study investigates the influence of these fragments on cell attachment of human granulocytes in vitro. While leaving unaffected the adhesion of human umbilical vein endothelial cells (HUVEC) on gelatine-coated glass, both FDP fragments at 50 micrograms/ml inhibited granulocyte attachment to glass as well as to HUVEC monolayers. At the same concentration, the fragments diminished the superoxide release of stimulated granulocytes. These results suggest a modulatory role of pathologically elevated FDPs on the granulocyte function cascade.

Cell Adhesion↗
PubMed1991

Hemodynamic variables and plasma levels of PGI2, TXA2 and IL-6 in a porcine model of recurrent endotoxemia.

The pulmonary and systemic hemodynamic effects of recurrent endotoxemia were studied in pigs over a 48-hr period. Six pigs of the test group were given 0.5 micrograms/kg of an E. coli endotoxin (WO111: B4) over 60 min at the beginning and in the middle (22 hr) of the experiment. Three pigs given the same amount of physiological saline solution served as controls. The hemodynamic response to the first LPS injection was characterized by severe pulmonary hypertension, a significant increase in systemic vascular resistance, and a marked decrease in cardiac output. Circulating TxB2 levels were higher than those of 6-keto-PGF1 alpha levels, so that the first response to LPS is influenced by the vasoconstrictive actions of TxA2. With the second LPS application, the pulmonary response was attenuated, although a significant increase of pulmonary artery pressure and pulmonary vascular resistance occurred. Once again systemic vascular resistance rose and cardiac output decreased, but this time plasma levels of 6-keto-PGF1 alpha were greater than those of TxB2. Toward the end of the experiment, we noted the progressive onset of a hyperdynamic and hypotensive state. Systemic vascular resistant index decreased to 50% of the baseline value. IL-6, a cytokine of systemic importance during the course of septic shock, markedly and significantly peaked after each LPS injection. Circulating plasma levels in response to recurrent endotoxemia are described.

Animals↗
PubMed1991

[Myocarditis caused by Toxoplasma gondii and Aspergillus fumigatus after orthotopic heart transplantation].

This report describes the case of a 56-year-old patient, who died 53 days after orthotopic heart transplantation due to myocarditis caused by infection with Aspergillus fumigatus and Toxoplasma gondii. Aspergillosis was diagnosed by transthoracic needle aspiration of a pulmonary infiltration. Endomyocardial biopsy showed toxoplasma pseudocysts. Autopsy revealed myocardial infection with both infectious agents. Despite specific therapy, myocarditis determined the fatal outcome in this case. The value of invasive techniques for specific diagnosis of infectious diseases in immunocompromised patients is discussed.

Aspergillosis↗
PubMed1990

Migration assay for endothelial cells in multiwells. Application to studies on the effect of opioids.

An assay system is described which permits rapid and effective evaluation of endothelial cell repair, using cells growing in a monolayer. With this method it was possible to obtain highly significant results. For example, endothelial growth factor and heparin, significantly enhanced cell migration and/or proliferation, whereas beta-endorphin, an endogenous opioid, had no effect on the migration and/or proliferation of human umbilical vein endothelial cells. This model may be used to study the cell migration of a variety of cell types which under certain experimental conditions (e.g., irradiation) do not proliferate.

Cell Division↗
PubMed1990

In vitro studies on the expansion of endothelial cell monolayers on components of the basement membrane.

The purpose of the present study was to observe the expansion of a monolayer of endothelial cells over specific components of the basement membrane. This was performed in vitro in a monolayer expansion assay over 5 days. The control surface was uncoated glass in the form of coverslips. Test substances were coated at a concentration of 10 micrograms/ml. The highest expansion was obtained with a high molecular weight fragment mixture of collagen type IV (IV-F, consisting of 75, 120 and 140 KD fragments), followed by fibronectin. Collagens type I, III and IV tetramer gave similar results, less than fibronectin or collagen type IV-F, although all of the above basement membrane coatings promoted expansion significantly above that of the control (P less than 0.01). The poorest expansion was obtained with laminin, which was significantly less than the control. The pentapeptide GRGDS, related to the fibronectin cell binding region, gave expansion significantly below that of the intact fibronectin molecule, as did the intact collagen type IV molecule compared with type IV-F (P less than 0.025). This indicates that sequences of the fibronectin molecule other than the cell binding sequence may be involved in promoting endothelial cell expansion. In addition, the integrity of the collagen type IV molecule does not appear necessary for this effect. On the contrary, the higher movement on IV-F may represent an inherent repair mechanism in damaged endothelium. Autoradiographic studies show that endothelial cell proliferation at the expanding front is involved in the migration assay.

Amino Acid Sequence↗
PubMed1990

Adhesion and spreading of corneal endothelial cells on collagens type I and IV in vitro: a model to study mechanisms of endothelial repair.

In vitro assays using endothelial cells (EC, bovine corneal) were performed to study adhesion and spreading on collagen types I and IV. Adhesion was quantitatively analyzed by counting the EC under a light microscope. Spreading was determined by measuring cell area using a scanning electron microscope (SEM). Collagen types I, IV, and IV-F, a mixture of 70, 120, and 140 KD fragments of type IV, all promoted EC adhesion, Types IV and IV-F showed evidence of giving a more marked adhesion than type I. A study of cell area, carried out under identical conditions, such as those in the adhesion assay, showed that types I and IV-F, but not type IV, promoted cell spreading. This provides evidence that cell adhesion and spreading are indeed separate biological phenomena. Furthermore, the ability of fragments of type IV collagen to promote both cell adhesion and spreading may represent an inherent repair mechanism in damaged endothelium.

Animals↗
PubMed1990

Opioid influence on the adherence of granulocytes to human umbilical vein endothelial cells in vitro.

Recent studies revealed the existence of opioid receptors on human polymorphonuclear leukocytes (hPMN) and reported the effects of endogenous opioids on hPMN migration and adherence on glass or serum coated glass. Extending these studies, two different assay systems served to quantify the two basic events of adherence: attachment and spreading. hPMN in suspension were allowed to settle under the influence of beta-endorphin on human umbilical vein endothelial cells. After 30 and 240 sec the number of attached cells was enhanced 2.5-fold. Studying the spreading of cells, beta-endorphin increased the area 1.5-fold. Since adherence precedes the migration of hPMN through the endothelial layer towards foci of inflammation, the results suggest a modulatory role of endogenous opioids in defence mechanisms.

Adult↗
PubMed1990

Differential expansion of human endothelial monolayers on basement membrane and interstitial collagens, laminin and fibronectin in vitro.

In this study the ability of a human endothelial cell monolayer to expand over specific components of the basement membrane and extracellular matrix was investigated over a 5-day period. The method was intended as a model to study the mechanisms of endothelial regeneration. All components were coated onto sterile coverslips at a concentration of 10 micrograms/ml. The highest expansion was obtained on fibronectin, laminin and collagen type III, all three being statistically significantly greater than on the uncoated control surface (0.002 greater than p greater than 0.0001). Collagens types I and IV and a high molecular weight fragment mixture of type IV (IV-F, consisting of 75, 120 and 140 kD fragments) elicited approximately similar expansion rates, significantly higher than the control (0.02 greater than p greater than 0.003), although significantly lower (approximately 15%) than collagen type III, fibronectin and laminin (p less than 0.001). The high monolayer expansion on collagen type III is surprising, as it is a relatively minor biosynthetic product of the endothelial cell. It could, however, be of significance in wound healing, in which endothelial cells come into contact with this interstitial collagen. In addition, the similar results obtained with collagens IV and IV-F indicate that expansion of the endothelial monolayer is not dependent on the integrity of the tetrameric structure of type-IV collagen.

Basement Membrane↗
PubMed1990

[Comparative studies on collagen expression of chondrocytes in monolayer and spheroid culture].

Dedifferentiation of cells is well known in cell culture biology. This phenomenon is examined in comparative studies on collagen expression of chondrocytes in monolayer and spheroid culture. Immunohistochemical studies were carried out by the indirect peroxidase technique. In the differentiated state a positive reaction for collagen type II was found. This was lost as dedifferentiation took place, in which case positivity for collagen types I, III, and V increased.

Cartilage↗
PubMed1990

[DNA extraction and Southern blot analysis in paraffin embedded material].

DNA was extracted from formaldehyde fixed and paraffin embedded tissue by the use of a modified extraction protocol. In all cases the recovered DNA was more degraded than DNA from fresh or frozen tissue. Fixation times of more than 4 days made it impossible to use the extracted DNA for Southern Blotting; DNA from paraffinized tissues not older than 1 or 2 years could be used for Southern Blotting after digestion with restriction enzymes, but we did not succeed in showing bands with restriction fragments more than 10 kb in length. We conclude that SBA analysis for malignant lymphomas with DNA extracted from routinely paraffin-embedded tissues isn't possible, because the restriction fragments looked for are in many cases longer than 10 kb.

Blotting, Southern↗
PubMed1989

Interaction between endothelial cells and basement membrane components. In vitro studies on endothelial cell adhesion to collagen types I, III, IV and high molecular weight fragments of IV.

Understanding the mechanisms involved in maintaining the integrity of the vascular endothelium is fundamental to studies on atherosclerosis, thrombosis, inflammation and tumor invasion. One of the essential aspects is the relationship between the endothelial cell (EC) layer and the underlying components of the basement membrane (BM). The importance of the biological role of the individual components of the BM in the promotion of EC adhesion is investigated. In this study suspensions of bovine corneal ECs (BCECs; 5 x 10(4)/ml) were used to investigate the adhesion of EC to collagen type IV and a mixture of fragments of the tetrameric molecule (IV-F, consisting of 75, 120 and 140 kD fragments), as well as collagen types I and III, coated at a 10-micrograms/ml concentration onto glass coverslips in vitro. Adhesion was quantified after 2 h of interaction by direct counting in the light microscope following fixation of the adherent cells. Collagens type IV and IV-F markedly promoted BCEC adhesion both in the presence or absence of 10 or 50% fetal calf serum, indicating that the integrity of the tetrameric molecule is not required for EC adhesion to collagen type IV, but can be replaced by high molecular weight fragments. Collagens type I and III increased EC adhesion in the absence of serum, although not in the presence of serum. Indirect evidence for a possible role of fibronectin in EC adhesion to type-IV collagen is given by the ability of the tetrapeptide (Arg-Gly-Asp-Ser (10 micrograms) to temporarily block (15-30 min) the adhesion-promoting effect of type-IV collagen. The nature of the adhesion sequences on the fragments of type-IV collagen remains to be elucidated.

Amino Acid Sequence↗
PubMed1989

[Role of the endothelium in adult respiratory distress syndrome (ARDS): the present and future].

Various morphological studies indicate that the microcirculation plays a vital role in the development of ARDS. The significance of the structural and functional integrity of the endothelium for normal pulmonary function is supported by cell biological data. Biochemical studies in bronchoalveolar lavage and blood from ARDS-patients, coupled with studies in animals and endothelial cell cultures support the role of a variety of mediators such as complement factors, products of the coagulation cascade and fibrinolytic system, enzymes, endotoxins and metabolites of arachidonic acid. Of particular importance is the interaction between neutrophilic granulocytes and the endothelium, although the individual components of this interaction and the relationship between cellular and humoral factors remain unclear. Furthermore, the literature shows that it is still uncertain, how the data obtained from studies in vivo and in vitro can be applied to ARDS in humans. Future research in this field must come to terms with the cell biology and pathobiology of the pulmonary endothelium, a hitherto neglected aspect. In addition, studies are essential to investigate possible additive or synergistic effects of mediators on inflammatory and endothelial cells. Finally, the role of more recently discovered inflammatory mediators and modulators in the pathogenesis of ARDS requires clarification.

Animals↗