Biomedical subjects

A Kruse

Publications and source records attributed to A Kruse.

At least 109 records · Page 6Linked to original sources

PubMed1994

Prospective study of prevalence and endoscopic and histopathologic characteristics of duodenal polyps in patients submitted to upper endoscopy.

BACKGROUND: Retrospective studies of duodenal polyps have shown a prevalence of 0.3%-1.5% in patients referred to upper endoscopy, and histopathologic classifications have been inconsistent. METHODS: A prospective consecutive study was carried out in 584 patients referred to diagnostic upper endoscopy. Symptoms were registered on a questionnaire, endoscopic and histopathologic findings on standard forms. The same pathologist evaluated all biopsy specimens. RESULTS: Twenty-seven patients had polyps in the first and/or second part of the duodenum, for a prevalence 4.6%. Sixteen polyps were either inflammatory (nine polyps) or ectopic gastric mucosa (seven polyps). Both of these polyp types were practically always non-solitary, sessile, small, and located in the duodenal bulb. Seven polyps were covered by normal mucosa, three being endoscopically typical lipomas. Two polyps were adenomas (0.4% of all the patients and 7% of the polyps), and both were found in the descending part. One hyperplastic polyp of the gastric type and one case of fibrosis were found. CONCLUSIONS: 1) Duodenal polyps are found in 4.6% of patients referred to upper endoscopy and should therefore be looked for. 2) Multiple, small polyps in the duodenal bulb are always benign and need neither biopsy nor treatment (in patients with familial polyposis biopsy is recommended). 3) In the descending duodenum polyps are rare, but a substantial number of them are adenomas. Biopsy is therefore mandatory in this localization.

Adenoma↗

PubMed1994

[Relevance of transmission of Epstein-Barr virus through blood transfusion].

In order to investigate the risk of transmission of Epstein-Barr Virus (EBV) by red cell concentrates (RCCs, bottom and top system), we examined 15 EBV-seronegative pediatric patients who received EBV-seropositive red cell concentrates prior to and up to 11 weeks after transfusion. None of these children showed serological or clinical signs of active EBV infection. To further explore this situation we estimated the number of EBV genomes in RCCs in comparison with whole blood units and found a significant reduction (1-2 EBV genomes in one RCC compared with 600-700 in one whole blood unit, p < 0.1%). The use of modern leukocyte depletion systems dramatically reduces the number of EBV-positive cells in RCCs, minimizing the risk of EBV infection. As there were no hints of transmission of EBV in current transfusion practice, the provision of EBV-seronegative RCCs for patients with high risk of infection does not seem to be necessary.

Child↗

PubMed1993

Investigations of the lymphokine system in elderly individuals.

Elderly people are at risk from an increased incidence of infections. Therefore we have studied the correlation between the production of several immunological parameters such as interferon-gamma (IFN-gamma), interferon-alpha-2 (IFN-alpha-2), interleukin-2 (IL-2), soluble interleukin-2 receptors (sIL-2R) and interleukin-6 (IL-6) in young controls of 25-34 years old and old individuals with a minimum age of 65 years. All persons were selected according to the basic concept of the 'Senieur protocol'. Heparinized blood was taken and cultured in the whole-blood assay. The determination of all cytokines in the supernatants of stimulated cultures was done by the ELISA technique. We found significantly decreased levels of sIL-2R and IFN-alpha-2 after stimulation, whereas the values of IFN-gamma and IL-2 showed no significant difference between elderly and young persons. The values of IL-6 showed a distinct trend towards an increased synthesis for the elderly. We also studied the lymphocyte subpopulations T4 and T8 by flow cytometry. Elderly individuals showed a significantly increased T4/T8 ratio, caused by a slightly but not significantly decreased level of T8 cells. These results show that the elderly have decreased values of some immunological parameters such as IFN-alpha-2 and sIL-2R, which might explain an increased susceptibility of elderly individuals to bacterial and viral infections.

Adult↗

PubMed1993

Cytokine production of the human monocytic cell line Mono Mac 6 in comparison to mature monocytes in peripheral blood mononuclear cells.

Mono Mac 6 is a human monocytic cell line with several features of mature blood monocytes such as CD 14 antigen expression, phagocytotic ability, and the functional ability to produce cytokines. This line is often used as an in vitro model to demonstrate the actions of monocytes. In our study, the production of cytokines by Mono Mac 6 cells in response to various stimulants was analyzed and compared to that of mature monocytes in peripheral blood mononuclear cells (PBMC). Interestingly, the Mono Mac 6 cells produced IL-1 alpha/beta, IL-6, and TNF-alpha after induction with the lectin phytohaemagglutinin A (PHA), mainly known as a T cell activator. The amount of cytokine release did not decrease in the presence of polymyxin B (Pmb), an inhibitor of LPS-induced effects. Kinetic studies revealed maximum cytokine levels 24h after stimulation, whereas human PBMC produced higher yields of all cytokines and enhancement was observed up to 48 hours after induction. Stimulation with the superantigen derived from the supernatant of mycoplasma arthritidis (MAS) induced expression of IL-1 beta, IL-6, and TNF-alpha, whereas staphylococcus enterotoxin B (SEB) did not induce any cytokine release. Further experiments analyzed the ability of Mono Mac 6 cells to produce IFN-alpha which is an important characteristic of mature monocytes. The cells were induced either with inactivated Newcastle Disease Virus (NDV), Sendai Virus, or the synthetic stimulus poly I:C IFN-alpha expression was not detected on the transcriptional or the protein level. In addition, no co-expression of IL-1 and IL-6 was observed in response to these stimuli. Since NDV, Sendai Virus, and poly I:C represent strong IFN-alpha inducers in peripheral blood monocytes, these data indicate that Mono Mac 6 cells lack the ability to express IFN-alpha. In conclusion, our findings show that this cell line is a potent cytokine producer, but the capacity to produce IFN is apparently deficient.

Cell Line↗

PubMed1993

T-cell surface molecule expression and interferon-gamma production in human cord blood.

We investigated T-cell surface antigen expression and the production of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) by human cord and adult blood cells. Cord blood lymphocytes stimulated with Staphylococcus enterotoxin B (SEB) released only minimal titers of IFN-gamma and IL-2 in comparison with adult blood lymphocytes. Systematic analyses of several cell-surface molecules on untreated cord blood and adult blood T cells demonstrated a significant reduction of CD8+ subset numbers in cord blood. Furthermore, cord blood lymphocytes did not express the memory T-cell marker CD45RO. No differences were found in gamma/delta T-cell receptor (TCR), CD5, and CD25 antigen expression between untreated cord blood and adult blood. However, cord blood mononuclear cells showed a decreased CD25 antigen expression in comparison to those of adults following activation with SEB. These observations suggest that the decrease in the proportion of some T-cell subsets and the absence of CD45RO memory T cells may be responsible for the diminished lymphokine production of cord blood lymphocytes.

Adult↗

PubMed1993

Helium-neon laser irradiation induces effects on cytokine production at the protein and the mRNA level.

The construction of an in vitro model allowed an investigation of the basic functions of immunocompetent cells after laser irradiation. Among low-energy laser sources, the helium-neon (He-Ne) laser, with a wavelength of 632.8 nm, has often been found to produce photobiological effects including evidence of interference with immunological functions. Previous experiments revealed an influence of He-Ne laser irradiation on concentrations of interleukin-1 alpha (IL-1 alpha), tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), and interferon-gamma (IFN-gamma) in supernatants of cultures of human peripheral blood mononuclear cells (PBMC) with increased cytokine concentrations after irradiation of 18.9 J/cm2 and decreased concentrations after irradiation of 37.8 J/cm2. Now, the mechanisms involved were studied. Results showed that cytokine production of cells stimulated with phytohemagglutinin (PHA), concanavalin A (Con A), or bacterial lipopolysaccharide (LPS) was altered significantly after laser irradiation but not after stimulation with staphylococcus aureus enterotoxin B (SEB). In situ hybridization of IFN-gamma mRNA producing PBMC revealed that the number of positive cells was modulated similarly. The results were identical in cultures of enriched monocytes (M phi) or enriched T cells. Cells of the human monocytic cell line Mono Mac 6 were also influenced after LPS stimulation, whereas constitutively IL-2-producing Jurkat cells were not influenced by laser irradiation at any energy density. Analysis of the IL-2 receptor (IL-2R) and intercellular adhesion molecule-1 (ICAM-1) expression in PBMC showed partial down-regulation of both receptors at 37.8 J/cm2, but only after stimulation with PHA.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Adhesion Molecules↗

PubMed1993

Deficient interferon-alpha response of newborns in comparison to adults.

Human peripheral blood mononuclear cells (PBMC) respond efficiently to viral infections with interferon (IFN)-alpha production. Using Newcastle disease virus (NDV) and Sendai virus as inducers, our experiments with purified mononuclear cell populations of healthy adult volunteers showed that monocytes were the main IFN-alpha producers in these systems. Using an ELISA, which specifically recognized IFN-alpha 2, and a bioassay, in which all subtypes were detected, IFN-alpha 2 was a major subtype expressed. Furthermore, IFN-alpha release was higher after induction with NDV than after stimulation with Sendai virus. To compare the IFN-alpha response of adult PBMC to human cord blood mononuclear cells the cells were stimulated with NDV or Sendai virus. The IFN-alpha response of cord blood mononuclear cells to Sendai virus was slightly reduced compared to that of adult cells. However, IFN-alpha 2 was a major subtype produced. In contrast, when cord blood mononuclear cells were stimulated with NDV the IFN-alpha release was strongly diminished. Furthermore, IFN-alpha 2 was not the major subtype expressed. By in situ hybridization the number of IFN-alpha-producing cells was quantified. We found that 1% of adult PBMC and newborn leukocytes showed detectable IFN-alpha mRNA after stimulation with either Sendai virus or NDV. In conclusion, these data suggest that the ability of cord blood mononuclear cells to produce IFN-alpha is diminished compared to adult PBMC. This impaired IFN-alpha response is not based on a reduced number of IFN-alpha-producing cells, but rather due to underlying control mechanisms of the newborns that are different from the regulation of adult PBMC.

Adult↗

PubMed1992

[Check-ups of colorectal neoplasms--current practice].

In order to investigate the practice for control of patients with colorectal adenomata and cancer, a questionnaire investigation was carried out in 1990-1991 among 53 Danish surgical departments. The investigation revealed great differences in the control programmes offered to these patients as regards the methods, the intensity and duration. In addition, differences were present in the control pattern for adenomata in specialist departments as compared with the remaining departments where there was a tendency to very frequent but, on the other hand, brief control. On the basis of these results, it is considered necessary that a reference programme should be prepared on this subject.

Adenoma↗

PubMed1992

In situ hybridization of the mRNA for interferon-gamma, interferon-alpha E, interferon-beta, interleukin-1 beta and interleukin-6 and characterization of infiltrating cells in thyroid tissues.

Cytokine mRNA production in the thyroid tissues of patients with various thyroid diseases was analysed by in situ hybridization. In addition, infiltrating leukocytes were characterized by immunohistologic studies using the alkaline phosphatase anti-alkaline phosphatase (APAAP) staining technique. The following clinical material was investigated: two cases of Graves' disease, one with high and the other with a low amount of infiltrating leukocytes as well as two cases of non-toxic goitre also showing considerable quantities of infiltrating cells. The hybridization was performed on tissue sections with antisense probes for interferon-gamma (IFN-gamma), IFN-alpha E, IFN-beta, interleukin-6 (IL-6) and IL-1 beta. A small number of individual cells were found to express high levels of mRNA for IFN-gamma, IL-1 beta and measurable amounts of IL-6 throughout the tissue sections. However, IFN-alpha E or IFN-beta were not detected. Cytokine expressing cells were noted in the tissue of one patient with Graves' disease and in two cases with non-toxic goitre. In these samples a high amount of infiltrating leukocytes (CD45+) was detected, especially CD3+, CD8+, CD4+ and CD45RA+ T cells, in addition to B cells and macrophages. In one case an unusually large amount of T cell receptor gamma/delta+ (TcR gamma/delta+) cells was found. However, one sample of thyroid tissue derived from a patient with Graves' disease was poorly infiltrated and showed few cells expressing cytokines. In conclusion, using thyroid tissue as an example, our data suggest that the application of in situ hybridization with antisense RNA permits the study of cytokine production in tissues of both autoimmune and non-autoimmune origin.

Adult↗

PubMed1992

Endoscopic management of postoperative bile leaks.

Thirty-two patients aged 15-89 years developed postoperative bile leakage. Twenty-eight had undergone cholecystectomy, with choledocholithotomy in 11, and four had had miscellaneous operations. Endoscopic retrograde cholangiopancreatography (ERCP) was performed 2-75 days after operation and revealed leakage from the cystic duct stump in 19 cases, from a T tube track in five, from the gallbladder and liver abscess cavity in two and from the major bile ducts in six. Major bile duct lesions were not generally amenable to endoscopic treatment, but the remaining 26 patients were treated successfully with internal stenting (22) or endoscopic sphincterotomy (four); bile secretion in all cases stopped within 1 week. One patient with cholangitis after an ERCP procedure was managed by antibiotics; no other complication occurred and there were no deaths related to the procedure. ERCP procedures are well tolerated in the postoperative period and may be performed under sedation. ERCP is the method of choice for dealing with bile leakage and ERCP procedures are effective for the most common causes of postoperative bile leakage; complications are rare.

Adolescent↗

PubMed1992

Coping with health problems in old age. A longitudinal approach.

An analysis of medical, psychological, and social data of the Bonn Longitudinal Study on Aging, comparing a subgroup of the BOLSA sample, which developed different forms of chronic disease four to six years after the beginning of the study, and a healthy subsample, points to different patterns of coping in these two subgroups. The sequence of these response patterns provides some evidence for a special form of psychosocial competence of chronically ill aged persons, which developed in an 'accelerated' way in the ill group, and in a retarded way in the initially healthy group. The findings emphasize the need for continuing research into the psychosocial aspects of coping with chronic disease in old age.

Adaptation, Psychological↗

PubMed1992

Cytokine production after helium-neon laser irradiation in cultures of human peripheral blood mononuclear cells.

The effects of laser light on the immune system have not been extensively characterized. Low-power laser sources, such as the helium-neon (He-Ne) laser with a wavelength of 632.8 nm, have been found to produce photobiological effects with evidence of interference with immunological functions. We have investigated the effects of He-Ne laser irradiation on Ficoll-Hypaque-isolated human peripheral blood mononuclear cells (PBMC). Cultured cells were irradiated for various times at two selected intensities and then stimulated with different mitogens. The rate of incorporation of 3H-thymidine into the DNA of stimulated cells decreased with increasing energy density. The levels of interleukin-1 alpha (IL-1 alpha), interleukin-2 (IL-2), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in supernatants of the cultures were determined (irradiated either before or after stimulation). When stimulating cells after irradiation, significantly increased levels of all cytokines were detected after 30 min of irradiation (18.9 J cm-2), whereas after 60 min of irradiation (37.8 J cm-2) cytokine levels were found to be significantly decreased.

Cell Division↗

PubMed1992

Induction of cytokines in human whole blood cultures by a mitogen derived from Mycoplasma arthritidis and by staphylococcal enterotoxin B.

Mycoplasma arthritidis produces a so-far only partially characterized soluble material (MAS) that has a potent mitogenic effect on T lymphocytes of several species. Similar to staphylococcal enterotoxins and a number of related toxins secreted by other species of bacteria, nanogram quantities of these so-called superantigens are sufficient to induce significant amounts of cytokines in the supernatant of lymphocyte cultures. Induction of interleukin-6 (IL-6) by MAS in murine bone marrow-derived macrophages has recently been described. In our study, we examined the differential effects of MAS and Staphylococcus aureus enterotoxin B (SEB) on human blood cells. When compared to MAS, SEB induced a higher proliferative response and, accordingly, a higher release of IFN-gamma. In contrast, large amounts of the macrophage products IL-1, IL-6 and tumor necrosis factor alpha (TNF-alpha) were observed in supernatants of cell cultures stimulated with MAS, whereas only small amounts were induced by SEB. Staphylococci and mycoplasmas are responsible for a number of diseases with various symptoms in man and animals. Our results suggest that SEB and MAS show different qualities in lymphocyte and macrophage stimulation which may be relevant in the pathogenesis of diseases.

Antigens↗

PubMed1992

Interferon and lymphokine production by human placental and cord blood cells.

The placenta plays an important role in protecting the fetus from maternal infections and in preventing an effective immune response of the mother against the fetus. We compared lymphokine production by human placental leukocytes with that of adult and cord blood leukocytes. Decidual and adult blood lymphocytes synthesized comparable quantities of interferon-gamma (IFN-gamma) following incubation with phytohemagglutinin (PHA). In contrast, lymphocytes of cord blood and fetal placental tissue stimulated with PHA produced very low titers of IFN-gamma. This defect was less marked after stimulation with staphylococcus enterotoxin B (SEB). In the presence of SEB, cord blood cells produced interleukin-2 (IL-2) and significant amounts of IFN-gamma. Production of IL-4 could not be detected. Collectively, these results indicate that fetal T lymphocytes show certain defects of lymphokine production.

Enzyme-Linked Immunosorbent Assay↗

PubMed1992

Pituitary histology in Cushing's disease.

OBJECTIVE: We assessed pituitary histology in patients with Cushing's disease. DESIGN: Systematic histological assessment of pituitary tissue removed at surgery. PATIENTS: Thirty-six consecutive patients cured from Cushing's disease by transsphenoidal neurosurgery. MEASUREMENTS: Microscopical examination of all available tissue removed at operation. RESULTS: After selective removal of tissue supposed to represent an adenoma in 25 patients this could be histologically verified in 18. In the 11 patients who had undergone a total hypophysectomy an adenoma could be demonstrated in three patients only, despite a systematic search of the entire pituitary gland. Only in 21 of the 36 cured patients (58%) could an adenoma be verified. CONCLUSIONS: Combining the present results with previous reports there is strong reason to believe that in some patients with Cushing's disease no histological lesion in the pituitary is verifiable.

Adenoma↗

PubMed1992

Pressure and blood flow in pituitary adenomas measured during transsphenoidal surgery.

In 48 patients undergoing transsphenoidal surgery for pituitary adenoma, the intrasellar pressure was recorded during surgery. In 14 patients, adenoma blood flow was measured with the technique of local injection of 133xenon. Median intrasellar pressure was 30 mmHg (range 8-62), n = 48, and median adenoma blood flow was 8 ml/100 g/min (range 0-37), n = 14. In two patients, blood flow in the anterior pituitary gland was measured, and values of 26 and 22 ml/100 g/min were obtained. The finding that intrasellar pressure is above central venous and intracranial pressure suggests the possibility that the adenoma and the anterior pituitary gland are supplied not only with venous blood, but receive an additional arterial supply at a less than normal arterial pressure. In three cases perfusion pressures that caused arrest of adenoma blood flow were found, and these observations are discussed with reference to pituitary apoplexy.

Adenoma↗

PubMed1992

Induction of cytokines in human peripheral blood and spleen cells by the Mycoplasma arthritidis-derived superantigen.

Recently, the mitogenic effects of the Mycoplasma arthritidis supernatant, MAS, and the induction of interferon-gamma (IFN-gamma) and interleukin-6 (IL-6) by MAS have been described. In the present series of experiments we investigated human peripheral blood mononuclear cells (PBM) and human spleen cells with respect to their production of these and other cytokines. In human spleen cell cultures and PBM, MAS induced the synthesis of interleukin-1 alpha (IL-1 alpha) and IL-1 beta. Both interleukins were secreted faster and in higher amounts by PBM. IL-6 was also induced by MAS in PBM and human spleen cells. The amounts of IL-6 measured by ELISA were higher in PBM, whereas the biological activity of IL-6 was higher in spleen cell cultures. T-cell products such as IL-2, IL-4, and IFN-gamma were also induced by MAS in PBM and spleen cells. The kinetics of IFN-gamma and IL-4 induction were negatively correlated. In PBM we found low levels of IL-4 and high IFN-gamma induction, whereas in spleen cells high titers of IL-4 and low IFN-gamma titers were observed. Collectively, our results indicate that MAS induces different networks of cytokine interactions depending on the organ from which the cells are derived.

Antigens↗

PubMed1991

[Removal of a displaced nasopharyngeal tube from the esophagus using an inflated catheter].

A safe and easily employed method of removal of a blunt foreign body from the oesophagus is described. The present case was a newly born infant with Pierre Robin's syndrome and congenital heart disease. A nasal tube had become displaced and the clinical condition did not permit endoscopic removal. By means of an inflatable balloon catheter introduced through the tube to the stomach, the foreign body could be removed without difficulty.

Catheterization↗