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Biomedical subjects

N Obel

Publications and source records attributed to N Obel.

At least 55 records · Page 3Linked to original sources

Catheter drainage of pleural fluid collections and pneumothorax.

A technique for virtually atraumatic placement of small size chest catheters for suction drainage of pleural effusions and pneumothorax in the dog and cat is described. Thirty-nine dogs and two cats were treated for pyothorax (10 cases), hydrothorax (eight), chylothorax (three), haemothorax (three), haemothorax/ pneumothorax (three) and pneumothorax (14). In all 41 cases, thin or viscous fluid and/or air were efficiently drained. The mean period of drainage was four days (range, 0.5 to 18 days). The average amount of fluid removed from each patient in 24 hours was 530 ml in pyothorax cases (range, 140 to 1100 ml) and 1300 ml in the other cases (range, 20 to 5000 ml). In 40 cases there were no complications related to the procedure. One dog with severe pleural adhesions was euthanased because of lung perforation and pneumothorax secondary to misplacement of the catheter.

Animals↗

Soluble tumor necrosis factor (TNF) receptors conserve TNF bioactivity in meningitis patient spinal fluid.

The content of tumor necrosis factor (TNF)-alpha antigen and the bioactivity of soluble TNF receptor type II (sTNF-RII) in cerebrospinal fluid (CSF) from 29 patients with meningeal symptoms and fever were examined. Immunoreactive TNF was demonstrated in CSF from 4 of 7 patients with bacterial meningitis. In 3 of 8 patients with aseptic meningitis, CSF also contained TNF, but TNF bioactivity was confined to samples from patients with bacterial meningitis. Bioactive TNF was exclusively in high-performance liquid chromatography fractions containing 30- to 60-kDa proteins. Lipopolysaccharide induced down-regulation, possibly after shedding of granulocyte surface membrane TNF-RII. Consistently, there was a statistically significant correlation between sTNF-RII and CSF leukocyte counts. Bioactive TNF was found only in CSF containing >1 ng of sTNF-RII/mL; samples without TNF bioactivity contained less sTNF-RII. Thus, a stabilizing effect of sTNF-RII on the oligomeric cytokine in vivo is plausible.

Cells, Cultured↗

Serological and clinical findings in patients with serological evidence of reactivated Epstein-Barr virus infection.

IgM directed against Epstein-Barr virus (EBV) early antigen (IgM-EA) has been established as an early marker of EBV infection and IgG directed against Epstein-Barr virus nuclear antigen I (IgG-EBNA-1) as a late marker. Simultaneous seropositivity to IgM-EA and IgG-EBNA has therefore been proposed as indicating reactivation of latent EBV infection. We have studied 191 patients with serological evidence of reactivated EBV infection with regard to clinical presentation, antibodies directed against EBV viral capsid antigen (IgM-VCA, IgG-VCA), cytomegalovirus (IgM-CMV), human herpesvirus 6 (IgM-HHV-6). IgM rheumatoid factor (IgM-RF), anti-nuclear or anti-cytoplasmic antibodies (ANA/ACA), and total IgM. The clinical manifestations varied considerably, but a diagnosis was established in 121 of the patients. The diversity of the clinical diagnosis probably reflects common reasons for requesting an EBV serological test rather than clinical manifestations of reactivated EBV infection. Only 5.8% of the patients with "serological EBV reactivation" gave a positive result for IgM-VCA. We conclude that "serological EBV reactivation" does not represent an entity relating to clinical manifestations, but probably reflects a non-specific activation of the immune system.

Antibodies, Viral↗

Effects of methotrexate, sulphasalazine and aurothiomalate on polymorphonuclear leucocytes in rheumatoid arthritis.

The aim of the study was to evaluate the effects of treatment with methotrexate, sulphasalazine and aurothiomalate on polymorphonuclear leucocytes (PMN) in rheumatoid arthritis (RA). Circulating PMNs from 58 RA patients treated with either methotrexate (n = 27), sulphasalazine (n = 16) or aurothiomalate (n = 15) were assayed for their chemotactic capacity and generation of superoxide anions. The expression of CD18/CD11b was measured for 17 RA patients treated with methotrexate. Chemotaxis and generation of superoxide anions were not affected by any of the three drugs. We found no difference in the expression of CD18/CD11b in RA patients treated with methotrexate compared to healthy subjects. Further methotrexate and aurothiomalate did not in vitro alter chemotaxis, generation of superoxide anion or expression of CD18/CD11b on normal PMNs. In conclusion we found no evidence that the effect of methotrexate, aurothiomalate or sulphasalazine in RA can be explained by modulation of chemotactic ability or superoxide anion generation of peripheral circulating PMNs.

Adult↗

Behavioural studies in healthy ponies subjected to short-term forced recumbency aiming at an adjunctive treatment in an acute attack of laminitis.

The authors postulated that a period of forced recumbency during an acute attack of laminitis may counteract the disabling effects on the secondary epidermal laminae. On the basis of this concept a study was made of the behavior of three healthy Shetland ponies when placed in a box in which the ceiling was too low for a standing position but allowed comfortable sternal recumbency. When the height of the box was about 125% of the vertical distance between the withers and the sternum, the ponies lay calmly during most of the experimental period and the rare attempts at rising did not seem to put any major load on the hoofs. The possibility of using short-term forced recumbency as adjunctive treatment in an acute attack of equine laminitis is discussed.

Acute Disease↗

Quantification of neutrophil chemotaxis: a comparison of stereological and 51Cr-labelling methods.

A stereological method has been used to estimate the number of migrated polymorphonuclear leukocytes in a multipore filter assay. The estimates have been compared to those obtained with conventional 51Cr-labelling methods. The precision of the estimates in individual subjects with the two methods was similar, and in both cases the contribution to the interindividual variance made by the methods was small compared to the biological variance. However, the 51Cr-labelling method resulted in a significant reduction in the fraction of neutrophils that migrated as well as a delay in the chemotactic response. Optimal assay conditions with regard to sample size, cell concentration, incubation time and chemoattractant fMLP concentration have been established for the stereological method and the virtues of the two techniques discussed.

Chemotaxis, Leukocyte↗

Evaluation of Abbott TestPack RSV and an in-house RSV ELISA for detection of respiratory syncytial virus in respiratory tract aspirates.

The Abbott TestPack RSV was compared with an in-house RSV enzyme-linked immunosorbent assay (ELISA) for detection of respiratory syncytial virus (RSV) antigen. Nasopharyngeal specimens were obtained from 121 inpatients. RSV antigen was detected in 46 specimens by the Abbott TestPack, 42 of these being confirmed by the in-house RSV ELISA. Of the 75 specimens tested negative in the Abbott TestPack RSV, one was found positive by the in-house RSV ELISA. The sensitivity and specificity of the Abbott TestPack RSV versus the RSV ELISA were 98% and 95% respectively.

Antigens, Viral↗

Chronic ulcerating acyclovir-resistant varicella zoster lesions in an AIDS patient.

We describe a 28-year-old HIV-infected woman with AIDS, defined by cerebral toxoplasmosis and a CD4-count of less than 10 x 10(6) cells/I, who, after several eruptions of genital herpes and typical dermatomal herpes zoster, all successfully treated with acyclovir, developed chronic cutaneous ulcerating lesions on a finger and on the tibia. The lesions were found to contain varicella zoster virus antigen but repeated treatment courses with acyclovir were unsuccessful. After a course of intravenous foscarnet the lesions resolved. They recurred after discontinuation of foscarnet but finally responded to a second course of treatment.

AIDS-Related Opportunistic Infections↗

Impaired neutrophil chemotaxis after cardiac surgery.

Chemotaxis of circulating peripheral neutrophils was studied in 12 patients undergoing elective cardiac surgery. Tests of neutrophil chemotaxis were made preoperatively and 16-20 hours postoperatively, using a multipore filter assay. Statistically significant postoperative decrease was demonstrated in both stimulated and random neutrophil migration (p = 0.012 and p = 0.009, respectively). Although the peripheral neutrophil count showed a statistically significant postoperative increase (p = 0.001), the increase did not correlate to the decrease in neutrophil chemotaxis. Nor could correlation be demonstrated between the altered neutrophil chemotaxis and any per- or postoperative variables.

Anesthesia, General↗

Improved vaccination response during ranitidine treatment, and increased plasma histamine concentrations, in patients with B cell chronic lymphocytic leukemia.

Patients with B cell chronic lymphocytic leukemia (B-CLL) have decreased capacity to mount relevant antibody responses upon immunization, and development of hypogammaglobulinemia is part of the natural history of the disease. We investigated the influence of histamine type-2 (H2) receptor blockade by ranitidine on the in vivo antibody production in B-CLL patients following vaccination. Anti-polysaccharide antibodies in B-CLL patients, vaccinated with a tetanus-toxoid conjugated vaccine against Haemophilus influenzae type-B (Hib), reached long-term protective levels in more than 90% of B-CLL patients randomized to ranitidine treatment, as compared to 43% of the untreated patients (P = 0.024). No difference in the response to vaccination against influenza virus types A and B protein could be detected between the two groups. Plasma histamine levels were 2-fold to 20-fold higher in 23 out of 31 B-CLL patients, compared to normal controls, and these levels showed a significant positive correlation to disease duration. These findings indicate the possibility of improving in vivo antibody production against a highly relevant pathogen in B-CLL patients by histamine type-2 receptor blockade, and the combined finding of an immune-stimulatory effect of ranitidine and increased plasma histamine levels, strongly suggests the involvement of histamine in the pathogenesis of B-CLL immunodeficiency.

Adjuvants, Immunologic↗

Evaluation of a method for measurement of intracellular killing of Staphylococcus aureus in human neutrophil granulocytes.

A modified method for measurement of intracellular killing of Staphylococcus aureus in human neutrophil granulocytes is described. After phagocytosis of S. aureus the extracellular bacteria were sufficiently removed by repeated centrifugations and washings of the granulocytes. The optimal conditions for incubation of granulocytes for measurement of intracellular killing were found to be 37 degrees C in the presence of 5% CO2. Under these conditions, stable pH, the viability and the capacity of the granulocytes for superoxide anion generation were preserved. The number of intracellular viable bacteria was determined after lysis of the granulocytes, which should be done in H2O at pH 11 to ensure sufficient cell lysis. The kinetics and individual variation of the intracellular killing are described. The intra- or extracellular location of surviving bacteria was studied. After approximately 8 h incubation we observed intracellular growth of S. aureus followed by lysis of granulocytes and extracellular growth of bacteria. Consequently, the incubation period should not be extended beyond 5 to 8 h when the assay is used to study the effects of antibiotics on intracellular killing.

Adult↗

A transtracheal catheter for recording the static tracheal pressure in the exercising horse.

After giving an account of the principles of pressure measurement in flowing air and a review of the literature on tracheal catheters, the authors describe the construction, the introduction and the function of their own transtracheal catheter. This is a teflon catheter with several side-ports which is introduced into the cervical trachea by a guide technique. After introduction, the catheter is stiffened by the insertion of 2 steel wires. The catheter was studied in model experiments concerning: a) the ability to measure the static pressure in flowing air, and b) the dynamic accuracy of a recording system built up around the catheter. The results indicated that the intratracheal pressure sensed in exercising horses well reflected the static pressure, and that the dynamic accuracy of the recording system was good to about 60 Hz. The present technique of recording the intratracheal pressure was used on 122 occasions in 69 exercising horses with only one complication referable to the catheter occurring. The transtracheal route of catheterisation may be superior, as catheters introduced by this route do not appear to influence the function of the pharynx and larynx. In contrast, nasotracheal catheters that traverse the larynx, might interfere with the respiratory function.

Airway Resistance↗

Normal oxidative activity and chemotaxis of circulating neutrophils in patients treated with photopheresis.

In photopheresis peripheral leukocytes are exposed to photoactivated 8-methoxypsoralen in an extra-corporeal flow system. The present study was performed to characterize the effect of photopheresis upon the function of peripheral circulating neutrophils. Superoxide generating capacity and chemotactic ability of peripheral circulating neutrophils were tested in seven patients immediately before and after treatment with photopheresis. Superoxide generation stimulated by phorbol-12-myristate-13-acetate and N-formyl-methionyl-leucyl-phenylalanine (fMLP) and fMLP-induced chemotaxis were found not to be influenced by photopheresis. We conclude that circulating neutrophils obtained from patients treated with photopheresis possess normal superoxide-generating capacity and chemotactic ability.

Adult↗

Microscopic examination of sperm as the diagnostic clue in a case of Schistosoma haematobium infection.

Early diagnosis and treatment of Schistosoma haematobium infections is imperative to prevent chronic manifestations of the disease. Microscopical examination of urine and faeces, and rectal biopsy are widely used standard methods for the rapid diagnosis of schistosomiasis. We report a case in whom numerous Schistosoma haematobium eggs were demonstrated in sperm, even though repeated examination of urine and rectal biopsies had been futile. It is concluded that the case presented demonstrates the importance of using sperm as an alternative sample material when schistosoma eggs are not found in conventional sample materials from male patients suspected of being infected with Schistosoma haematobium.

Adult↗

Preserved oxidative activity and chemotaxis of circulating neutrophils in patients with acute myocardial infarction.

The neutrophil granulocyte seems to be intimately involved in the destructive processes leading to myocardial damage observed in ischaemic/reperfusion injuries. The process may cause stress to the peripheral circulating neutrophils leading to exhaustion and decreased function. We conducted a study in which the function of peripheral neutrophil granulocytes was measured in 21 patients with an acute myocardial infarction 0-24 and 48-72 h after the onset of symptoms. Ten patients received thrombolytic treatment (streptokinase). Neutrophil function was judged by superoxide generating capacity and chemotactic ability. Compared to healthy controls neutrophil function was found to be preserved in patients with myocardial infarction. Furthermore, streptokinase treatment of the patients did not modulate neutrophil function. In-vitro studies demonstrated that low concentrations of streptokinase (12-300 U.ml-1) or recombinant plasminogen activator (0.12 micrograms.ml(-1)-3.0 micrograms.ml-1) did not influence neutrophil superoxide generation. However, at higher concentrations (100-10,000 U.ml-1 and 10-100 micrograms.ml-1 respectively) both thrombolytics induced a significant increase in phorbol myristate acetate-stimulated superoxide generation. Neither of the thrombolytics influenced neutrophil chemotaxis in vitro. It is concluded that neither myocardial infarction nor streptokinase treatment decrease superoxide generating capacity or chemotactic ability of circulating neutrophils.

Adult↗

Phagocytosis and stimulation of the respiratory burst in neutrophils by Pneumocystis carinii.

Phagocytosis and superoxide production of neutrophils stimulated with Pneumocystis carinii were studied using P. carinii obtained from rats and neutrophils and serum from healthy blood donors. Superoxide generation increased in a dose-related way to the number of pneumocysts added and was significantly higher when the parasites were opsonized. The use of heat-inactivated serum for opsonization reduced superoxide production somewhat, but not significantly. Preincubation of neutrophils with recombinant human granulocyte-macrophage colony-stimulating factor (rHuGM-CSF) increased superoxide production in neutrophils stimulated with pneumocysts from 7.0 to 9.6 fmol/cell/20 min; however, the production in unstimulated cells increased by the same amount. Activation of the respiratory burst was paralleled by phagocytosis, and very few phagocytic vacuoles were found in neutrophils stimulated with unopsonized pneumocysts. By electron microscopy, various stages of cyst degradation were seen.

Animals↗

Normal immunological status in four patients with ectrodactyly-ectodermal dysplasia-clefting syndrome (EEC-syndrome).

Lobster-claw deformity of the extremities, clefting of the primary and secondary palate, ectodermal dysplasia, and atresia of the lacrimal system are common features of the ectrodactyly-ectodermal dysplasia-clefting syndrome (EEC-syndrome). The patients often suffer from repeated infections of eyes, upper respiratory tract and urogenital system. To exclude an immunodeficiency as cause of the infectious predisposition in patients with EEC-syndrome, we screened the immunosystem in four related patients with EEC-syndrome. All patients were found to present normal immunoglobulin production, complement activity, lymphocyte-, and granulocyte function. We conclude that recurrent infections observed in the EEC-syndrome are not caused by an immunological defect, but seem to result solely from anatomical anomalies.

Abnormalities, Multiple↗

Methyl mercury, mercuric chloride, and silver lactate decrease superoxide anion formation and chemotaxis in human polymorphonuclear leucocytes.

Cytotoxic effects of mercuric chloride, methyl mercury, and silver lactate on polymorphonuclear leucocytes have been examined by assaying superoxide anion formation capability and chemotaxis of metal-exposed cells. Both superoxide anion formation and chemotaxis were negatively affected by all three metal compounds. Both bacteriotoxic functions were affected in a dose-dependent fashion, the functional deficits were seen at doses not affecting cell viability. Dose-response curves were remarkably similar for all three compounds. The bacteriotoxic capacity of polymorphonuclear leucocytes may be hampered by mercury and silver.

Cell Survival↗