Biomedical subjects

K Agren

Publications and source records attributed to K Agren.

10 recordsLinked to original sources

PubMed2000

The nasopharynx and the middle ear. Inflammatory reactions in middle ear disease.

The host-parasite interactions in the nasopharynx with bacterial colonization and antigen uptake in the lymphoid tissue, the adenoid, has an impact on the maturation of local and systemic immunity. The adenoid is a part of mucosa associated lymphoid tissue and is responsible for both effector and inductor functions in the nasopharynx. Increasing evidence supports the role of serum antibody in protecting the middle ear cavity from disease. There is evidence for a minor immunologic defect in a number of children with recurrent episodes of AOM.

Adenoids↗

PubMed1999

What is wrong in chronic adenoiditis/tonsillitis immunological factor.

The local immune response in adenoid and tonsil tissue can be visualized and the complexity of the cytokine network and effector molecule expression has not been illustrated in several different tonsillar entities. Many factors still remain to be learned in order to help us to understand the interactions between microorganisms and host in peripheral lymphatic tissue.

Adenoids↗

PubMed1998

Children with nocturnal upper airway obstruction: postoperative orthodontic and respiratory improvement.

UNLABELLED: Twenty children, aged 4-9 years, underwent adeno/tonsillectomy because of unequivocal anamnestic nocturnal obstructive breathing. Preoperatively, apnea-hypopnea index was > 5 in 10 cases only, AI > 1 in 17. Nineteen children had signs of increased respiratory labour in movement recordings and inspiratory EMG-activity. Oxygen desaturation index was 0 in 7 children, and nadir SaO2 was > or = 90% in 10. Cephalometry and dentition study models initially revealed significant changes, chiefly lateral cross-bite (n = 11) and vertical growth direction of the mandible. Tonsillar size or duration of disease was not correlated with the severity of polysomnographic findings, nor were orthodontic variables. Symptoms disappeared promptly postoperatively. After one year, respiratory recordings were normalized or improved in the majority of children, and orthodontic variables normalized or improved in all children. CONCLUSION: Oximetry and airflow recordings may be normal in children who benefit from treatment of anamnestic nocturnal obstruction. Craniofacial deformities are common and improve significantly with surgical treatment of the airway obstruction.

Adenoidectomy↗

PubMed1996

The production of immunoregulatory cytokines is localized to the extrafollicular area of human tonsils.

The localization and production at the single cell level of 19 different human cytokines, IL-1 alpha, IL-1 beta, IL-1ra, IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, TNF alpha, TNF beta, IFN gamma, GM-CSF, G-CSF, and TGF beta 1-3, were studied in cryopreserved tonsillar tissue using immunohistochemical staining. The cytokine producing cells, with the exception of IL-1 expressing cells, had a characteristic morphology due to the accumulation of cytokine onto the Golgi organelle. The production of each cytokine was localized to specific compartments in tonsillar tissue sections from children with tonsillar hypertrophy or recurrent tonsillitis in the resting state. Immunoregulatory cytokines such as IL-2, IL-3, IL-4, G-CSF, GM-CSF and TGF beta were produced in the extrafollicular area and entrapped on the cell membranes as well as in pudels in the extracellular matrix surrounding the producer cells. The dominating cytokines both in tissues from recurrent tonsillitis and tonsillar hypertrophy were GM-CSF, G-CSF, and TGF beta 1-3 which were synthezised predominantly in the reticular crypt site. IL-1 alpha, beta and IL-1ra, on the other hand, were localized to the surface and crypt epithelium and to scattered regions in the extrafollicular area. IL-2, IL-6, IFN gamma and IL-10 were found much more often in sections obtained from recurrent tonsillitis tissue compared with those from tonsillar hypertrophy. Reversely, an excessive production of IL-4 was noted in tonsillar hypertrophy compared with that in recurrent tonsillitis. Thus, concomitant production of multiple cytokines was evident with similarities but also differences in cytokine pattern between the two groups studied. The data suggest that T-cell mediated B-cell activation and differentiation take place in the extrafollicular area. Children with recurrent tonsillitis had a higher amount of B-cells and monocytes compared with children with tonsillar hypertrophy. However, the number of CD3, CD4, CD8 or cytoplasmic Ig-positive cells did not differ between the two groups.

Cell Movement↗

PubMed1995

Upregulated local cytokine production in recurrent tonsillitis compared with tonsillar hypertrophy.

In children with recurrent tonsillitis there may be persistent antigen deposition in tonsil tissue. even between exacerbations. If so, upregulation of immunocompetent cells should occur continuously, in contrast to tonsil tissue from children with tonsillar hypertrophy. The cytokine pattern was studied in cell suspensions prepared from tonsils obtained from 12 children undergoing tonsillectomy. The study group comprised 6 children with recurrent tonsillitis and 6 who had a history of tonsillar hypertrophy causing sleep apnea. Cytokine-producing cells (IL-1alpha, IL-1beta, TNFalpha, IL-6, IL-8, IL-2, IFNgamma, TNFbeta, IL-10 and IL-4) were characterized at the single-cell level by use of cytokine-specific monoclonal antibodies and indirect immunofluorescence technique. A constitutive production of IL-1alpha, IL-1beta, TNFalpha, and IL-8 was found in both groups (10-300/10(5) cells). However, the frequency of spontaneous IL-2, IFNgamma, TNFalpha, IL-6 and IL-10 was consistently low (10 +/- 10 cells) in both groups. Following restimulation by T-cell receptor ligation, using immobilized anti-CD3 mAb, with concentrations chosen so that it did not activate resting cells, increased frequencies of TNFalpha, IL-6, IL-8, IL-2, IFNgamma, IL-4 and 1L-10 synthesizing cells were induced in the recurrent tonsillitis group. Significantly higher incidences of IL-1beta, IL-6 and IL-2 producing cells were found in the recurrent tonsillitis group (60-200/10(5) cells, p <0.05). Microbiological evaluation in the tonsil tissue could not reveal tiny differences between the studied groups regarding bacterial or viral pathogens. However, this does not exclude persistent increased intracellular deposition of microbial antigens as a possible explanation for the elevated incidence of IL-1beta, TNF-alpha, IL-6, IL-8, IL-2, IFNgamma, IL-10 and IL-4 expressing cells noticed in patients with recurrent tonsillitis.

Cells, Cultured↗

PubMed1994

Concomitant in vivo production of 19 different cytokines in human tonsils.

Accumulating data indicate that cytokines, peptides involved in regulation of both physiological and pathological immune responses, are produced predominantly at the site of local antigen stimulation. Cytokine-producing cells were detected at the protein level in human tonsil tissue obtained from children with recurrent tonsillitis or infectious mononucleosis (IM). Concomitant production of 19 different human cytokines, interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1 receptor antagonist (ra), IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF, tumour necrosis factor-alpha (TNF-alpha), TNF-beta, interferon-gamma (IFN-gamma) and transforming growth factor-beta 1-3 (TGF-beta 1-3), was identified at a single-cell level by indirect immunohistochemical staining procedures and use of carefully selected cytokine-specific antibodies (Ab). Fresh frozen sections were fixed with 4% paraformaldehyde and permeabilized by 0.1% saponin treatment, eluting cholesterol from the cell-surface membrane and the Golgi complex. The intracellular localization of all cytokines, except IL-1 and IL-1ra, was demonstrated by a characteristic local cytoplasmic perinuclear configuration in producer cells. In addition, the immunoreactivity for certain cytokines (IL-2, IL-4, IL-5, G-CSF and GM-CSF) was expressed on the cell membranes and extended over a large extracellular area encompassing the producer cell. Localization of the cytokine to the Golgi organelle was established by co-staining with a monoclonal antibody (mAb) specific to the Golgi complex. Both the extra- and intracellular cytokine staining reactions could be blocked by preincubation of the cytokine-specific Ab with the corresponding purified natural or recombinant cytokine. A complex cytokine pattern was established in both groups studied, where most T-helper type 1 (Th1) and Th2 lymphokines were expressed in the tonsils but at different frequencies and localizations. Cells expressing IL-4, IL-5, IL-10 and IL-13, (Th2 response) were evident at higher frequencies in recurrent tonsillitis compared to sections from IM, which were associated with a more pronounced IL-2, IFN-gamma and TNF-beta expression.

Acute Disease↗

PubMed1990

Effect of amoxycillin/clavulanic acid on the aerobic and anaerobic tonsillar microflora in the treatment of recurrent tonsillitis.

30 patients with recurrent tonsillitis were treated with amoxycillin/clavulanic acid (500 mg/125 mg) t.i.d. for 10 days. The most often isolated potential aerobic pathogenic bacteria were Staphylococcus aureus, Streptococcus milleri and Haemophilus parainfluenzae. Group A streptococci were isolated from 7 patients. Anaerobic cocci and Bacteroides species were the dominating anaerobic bacteria isolated from the tonsils. Tonsillar cultures were taken before antibiotic treatment started, on days 11-12, day 30, and day 90. Beta-lactamase producing aerobic and anaerobic bacteria were present in 13 patients prior to treatment, on days 11-12 in 18 patients, on day 30 in 15 patients, and on day 90 in 13 patients. Group A streptococci were eradicated in 6/7 patients. In the aerobic tonsillar microflora, the numbers of viridans streptococci decreased during treatment but were normalized after 30 days. Only minor changes in the numbers of other aerobic microorganisms occurred during the investigation. The effect on the anaerobic microflora was minor and no new colonizing microorganisms were isolated during or after antibiotic treatment. All patients except one were cured on days 11-12. Five patients had another episode of tonsillitis during the observation period of 3 months. The antibiotic treatment was well tolerated in most patients and mild adverse events such as nausea, vomiting and diarrhoea were observed in 3 patients.

Adolescent↗

PubMed1989

Local versus general anaesthesia in tonsillectomy.

Thirty-eight patients, suitable for tonsillectomy under local anaesthesia, were randomized and operated on under either local or general anaesthesia. The following parameters were compared: time in the operating room, duration of the operation, peroperative haemorrhage, number of ligatures required for haemostasis, postoperative haemorrhage, infection and weight loss. Post-operative discomfort was assessed using a visual analogue scale and a water drinking test. The total consumption of analgesic drugs in the post-operative period was recorded. The investigation shows that tonsillectomy under local anaesthesia, in suitable patients, is a safe alternative to tonsillectomy under general anaesthesia, and that considerable resources can be saved if the operation is performed with local anaesthesia.

Adult↗

PubMedDate not supplied

Evaluation of some prognostic factors in small squamous cell carcinoma of the mobile tongue: a multicenter study in Sweden.

In a retrospective study of 58 patients from all over Sweden, treated for small squamous cell carcinoma of the mobile tongue (T1N0M0), different prognostic factors were evaluated. A partial glossectomy was performed as primary treatment in all patients. The cancer recurred in 28 (38%) of 58 patients. One of 7 patients with only local recurrence, and 9 of 14 with recurrence in the neck died of their disease. The relative survival rate was 77%. Of the prognostic factors tested, tumor thickness was found to be the most significant. In patients with tumor thickness was found to be the most significant. In patients with tumor thickness exceeding 10 mm, recurrences occurred in 58% (P less than 0.0048), and 87% (P less than 0.0164) died of their cancer. This represents a statistically significant higher degree when compared with tumor thickness of less than 10 mm. Elective treatment of the neck nodes is recommended in epidermoid cancer of the mobile tongue when tumor thickness exceeds 10 mm, even in stage I tumors (i.e., the surface extension diameter is smaller than 20 mm at most).

Adult↗

PubMedDate not supplied

Haemophilus influenzae and Streptococcus pyogenes group A challenge induce a Th1 type of cytokine response in cells obtained from tonsillar hypertrophy and recurrent tonsillitis.

We have previously shown that tonsil tissue both from children with tonsillar hypertrophy and recurrent tonsillitis is colonized and invaded by Haemophilus influenzae and Streptococcus pyogenes group A. In order to evaluate if these bacteria are involved in the immunopathogenesis of these two conditions, tonsillar cells from both groups were stimulated in vitro with intact, heat-inactivated H. influenzae or S. pyogenes A. The immunoreactivity was evaluated by assessing the induction of cytokine production (IL-1 alpha, IL-1 beta, TNF-alpha, IL-6, IL-8, IL-2, IFN-gamma, IL-4, TNF-beta and IL-10), which was detected at the single-cell level. All cytokines studied except IL-4 were induced in both groups after stimulation with H. influenzae or S. pyogenes A. The dominating cytokines were IL-1 beta, IFN-gamma and TNF-beta. No major differences in the cytokine pattern or number of cytokine-producing cells were noticed between the two patient cohorts after H. influenzae stimulation. Activation by S. pyogenes A bacteria gave rise to higher frequencies of IFN-gamma- and TNF-beta-synthesizing cells in the recurrent tonsillitis group. The incidence of CD4-, CD8-positive T cells and CD40-positive B cells was comparable between the two groups while the MAC-387-positive macrophages were significantly higher in the recurrent tonsillitis groups. In conclusion, a Th1 type of cytokine response was found in both groups following stimulation with H. influenzae or S. pyogenes A.

Antigens, Bacterial↗