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Biomedical subjects

M Tamm

Publications and source records attributed to M Tamm.

106 records · Page 6Linked to original sources
PubMed1995

Intracellular interleukin 6 mediates platelet-derived growth factor-induced proliferation of nontransformed cells.

The functional relevance of interleukin 6 (IL-6) in platelet-derived growth factor (PDGF)-induced cell growth was evaluated in cultures of human fibroblasts, vascular smooth muscle cells, and mesangial cells. The three isoforms of the PDGF--namely, PDGF-AA, -AB, and -BB--induced the expression of the IL-6 gene and proliferation of the nontransformed cells. PDGF-induced transcription, translation, and secretion of IL-6 were diminished in the presence of IL-6 antisense oligonucleotides. While neutralizing anti-IL-6 antibodies failed to affect the growth factor-dependent cell proliferation, IL-6 antisense oligonucleotides inhibited cell division. In addition, IL-6 antisense oligonucleotides abolished PDGF-induced transcription of the genes coding for the cell division cycle 2-related protein (CDC2) and proliferating cell nuclear antigen (PCNA), both of which are regulated in a cell cycle-dependent manner. It is concluded that PDGF-dependent proliferation of nontransformed cells involves the action of intracellular IL-6.

Base Sequence↗
PubMed1995

Ca(2+)-channel blockers modulate the expression of interleukin-6 and interleukin-8 genes in human vascular smooth muscle cells.

Ca(2+)-channel blockers at therapeutic concentrations were shown to modulate several processes underlying inflammation, such as growth factor-mediated activation of genes coding for the low density lipoprotein receptor and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase in human vascular smooth muscle cells (VSMC) (Block et al., 1991), and for interleukins in human mesangial cells (Roth et al., 1992). Two Ca(2+)-channel blockers, Manidipine (Roth et al., 1992) and Verapamil (Walz et al., 1990) have been shown to induce the expression of the gene coding for interleukin-6 (IL-6). Here we demonstrate that the four Ca(2+)-channel blockers, Amlodipine, Felodipine, Isradipine and Manidipine, at nanomolar concentrations, activate the transcription of the genes encoding IL-6 and IL-8 in primary human VSMC and fibroblasts. Ca(2+)-channel blocker-induced transcription is subsequently followed by secretion of the two ILs into the growth medium of the cells. In addition, we compared the action of the Ca(2+)-channel blockers with that of propranolol, a beta-adrenoceptor antagonist, or with furosemide, a diuretic, all of which are known to lower blood pressure. However, in contrast to the dihydropyridines, the two latter drugs failed to affect the expression of the two IL genes.

Adrenergic beta-Antagonists↗
PubMed1995

Exercise capacity as a predictor of postoperative complications in lung resection candidates.

Exercise testing with measurement of maximal oxygen uptake (VO2max) is increasingly used in the assessment of lung resection candidates, but its predictive value for postoperative complications remains controversial. We therefore sought to determine the prognostic value of VO2max compared with other pulmonary function tests. A consecutive group of 80 patients (mean age 61 yr; 57 males and 23 females) scheduled for lung resection (62 malignancies, 12 benign disorders, and 6 carcinoids) underwent pulmonary function tests and symptom-limited cycle ergometry. All patients underwent lung resections: 21 pneumonectomies, 45 lobectomies, and 14 segmental or wedge resections. Group A (64 patients, 80%) had an uneventful postoperative course, whereas Group B (16 patients, 20%) had complications; 3 of them died (4% overall mortality rate). In a stepwise logistic regression analysis used to determine independent risk factors for postoperative complications (within 30 d), VO2max expressed as a percentage of predicted (84 +/- 19 for Group A versus 61 +/- 11 for Group B) proved to be the best predictor (predictive value 85.5%). Although VO2max expressed in absolute values (ml/kg/min) was also highly predictive (79.5%), a ROC curve analysis proved the percentage predicted values to be significantly more sensitive. Of 9 patients with a VO2max < 60% of predicted, 8 had complications, including all 3 patients who died after resections of more than one lobe (sensitivity 50%, specificity 98%). The estimated probability (probit model SAS software package) of suffering no complication was 0.9 for VO2max > 75% of predicted and 0.1 for a VO2max < 43%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Early diagnosis of cytomegalovirus infection and disease in patients following kidney transplantation].

For early diagnosis of cytomegalovirus (CMV) infection after renal transplantation, 18 patients were monitored within the first 3 months. Blood leukocytes were assayed weekly for the presence of the CMV matrix protein p65 (antigenemia assay) and CMV DNA by the polymerase chain reaction (PCR). In 12 out of 18 patients, 70 (37.8%) of 185 blood samples were positive by antigenemia assay or by PCR. 49 and 115 samples concurrently were positive and negative by both tests. 8 blood samples were positive only by the antigenemia assay and 13 only by PCR. Therefore, the relative sensitivity of PCR and of antigenemia assay was 88.6% and 81.4% respectively. In 9 of 10 patients who were pre-transplant CMV seropositive and in 4 of 7 patients who were pre-transplant CMV seronegative and received a graft from a seropositive donor, CMV infection was detected by positive antigenemia and/or PCR. Four of these patients developed CMV disease. In all these patients, antigenemia assay and PCR were positive 7 to 16 days prior to onset of clinical symptoms. Antigenemia and PCR are rapid and sensitive methods for the detection of CMV infection 1 to 2 weeks prior to disease. In addition, the semi-quantitative assay of antigenemia enables monitoring of the efficacy of antiviral therapy.

Cytomegalovirus↗
PubMed1994

Donor and recipient predicted lung volume and lung size after heart-lung transplantation.

Lung volumes after heart-lung transplantation (HLT) were recorded and compared with measurements at the time of assessment for surgery and the predicted values for recipients. The influence of donor lung size and recipients' underlying lung disease was evaluated. All patients underwent HLT between April 1984 and April 1991, and only those 82 who survived for at least 6 mo were studied. Mean total lung capacity (TLC) at preoperative assessment was 112% (SD = 28%) of the value predicted for recipients. One month after HLT, mean TLC was 83% (SD = 15%) of the predicted value but increased to 100% (SD = 15%) after 9 mo. No further change in average TLC occurred for 5 yr subsequently. The mean TLC of patients with emphysema before surgery was 164% (SD = 26%) of the predicted value and fell to the predicted value within 1 mo of HLT. The TLC in patients with primary pulmonary hypertension before surgery was close to the predicted value, but postoperative predicted TLC was achieved later than in emphysema patients. A donor-versus-recipient difference in TLC of more than 1L at the time of assessment did not influence the adaptation to the predicted value. FEV1 and vital capacity (VC) rose from means of 70% (SD = 25%) and 63% (SD = 20%) at 1 mo to 96% (SD = 27%) and 91% (SD = 18%), respectively, at 9 mo after HLT. After HLT, TLC returns to the predicted value for the recipient, and not to the preoperative TLC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Mycoplasma hominis empyema following pleuropneumonia in late pregnancy].

Mycoplasma hominis (M. hominis) frequently colonizes the genital tract, but is rarely isolated from the respiratory tract. Dissemination of M. hominis has been documented in women with a febrile illness after delivery. Spontaneous recovery is the rule. A 32-year-old woman in the 29th week of pregnancy was hospitalized for pneumonia. She had to be ventilated for respiratory insufficiency and thoracic empyema. The child was delivered by section due to signs of stress in cardiotocography. In the ensuing days the mother's condition worsened, with fever, weight loss and persistent pleural effusion. Even after decortication and treatment with ceftriaxone fever and pleural effusion persisted. M. hominis was found in pleural fluid cultures. Treatment with doxycycline led to rapid defervescence and an improvement of the patient's condition.

Adult↗
PubMed1990

[Hyperkalemic emergency: causes, diagnosis and therapy].

Eight patients with life threatening hyperkalemia were treated in the intensive care unit over a period of 2 years. Serum potassium at admission was 7.1-11.2. Two patients had to be resuscitated and 3 exhibited quadriplegia or paralyses but were alert. Seven showed marked ECG change: in 5 the QRS-complexes were extremely broadened and in one case an AV-rhythm was observed; the atrial wave was absent in all 7 patients. Renal failure was present in 7 of 8 patients. In 6 of these 8 cases drugs were also involved in the development of hyperkalemia. The following therapeutic procedure is recommended for hyperkalemia: (1) injection of calcium, (2) inhalation or injection of beta 2-mimetics (well documented in the literature; clinical experience limited), (3) insulin and glucose i.v., (4) sodium bicarbonate, but only in case of metabolic acidosis, (5) hemodialysis, (6) cation exchange resins or furosemide in non-acute situations.

Acute Kidney Injury↗
PubMedDate not supplied

Increased prevalence of perennial allergic rhinitis in patients with obstructive sleep apnea.

BACKGROUND: Impaired nasal breathing is a risk factor for obstructive sleep apnea syndrome (OSAS). OBJECTIVES: The aim of this study was to determine whether atopy to perennial allergens and existence of perennial allergic rhinitis was a risk factor for OSAS. METHODS: In a case-control study, we compared the proportions of OSAS patients with atopy to perennial allergens and perennial allergic rhinitis to the proportions in patients with chronic obstructive pulmonary disease (COPD). Seventy-two OSAS patients (mean age 60.7 years; 79.4% male) and 44 COPD patients (mean age 63.6 years; 88.6% male) were selected from a hospital outpatients' clinic in Switzerland. All patients completed a respiratory symptom questionnaire, performed spirometry and had a skin prick test for atopy. RESULTS: OSAS patients were significantly heavier than COPD patients (BMI 32.4 +/- (SD) 6.6 vs. 29.2 +/- 6.6 kg/m2, p = 0.04) and had a better lung function than COPD patients (FEV1% predicted 91.3 +/- 19.2 vs. 51.6 +/- 18.9%, p < 0.001). Patients with OSAS were more likely to be sensitized to perennial allergens such as house dust mite (23.6 vs. 4.5%, p = 0.009) and dog (18 vs. 4.5%, p = 0.04) than the COPD patients. Perennial allergic rhinitis (having nose problems [nasal obstruction and/or runny nose and/or sneezing] all year and being atopic to at least one perennial allergen) was reported in 11% of OSAS patients but in only 2.3% of COPD patients (p = 0.15). CONCLUSION: We conclude that subjects with OSAS may have an increased risk of being allergic to perennial allergens and suffer from perennial rhinitis. Awareness of this risk may have important consideration in the clinical situation.

Administration, Intranasal↗
PubMedDate not supplied

Lung transplantation: management and complications.

Lung transplantation has become an accepted treatment modality for end stage lung disease including emphysema, fibrosing alveolitis, cystic fibrosis, pulmonary hypertension and bronchiectasis. Despite the use of potent immunosuppressive drugs, acute rejection occurs frequently, especially in the first few weeks and months after transplantation. Bacterial, viral and fungal infections frequently occur in lung transplant recipients. Rapid diagnosis and adequate treatment of infections is needed. The side effects with the use of long term immunosuppressive agents includes renal toxicity, hypertension, neurotoxicity, hyperlipidemia, leucopoenia, hyperglycaemia, weight gain, osteoporosis and malignancy. However, obliterative bronchiolitis (OB) which is regarded as a chronic rejection process remains the dominant cause of morbidity and mortality in the long-term survivors of lung transplantation. This article focuses on the postoperative and long term management of lung transplant recipients.

Humans↗
PubMedDate not supplied

Impaired proliferative response to concanavalin A in patients with rheumatoid arthritis: a consequence of drug-induced T-lymphocyte damage.

The proliferation of peripheral mononuclear cells in response to pokeweed mitogen (PWM) and concanavalin A (Con A) was studied in rheumatoid arthritis (RA). In order to discover possible defects in either of the cell types involved, enriched T-cells from RA patients and healthy controls were stimulated in cultures reconstituted with purified autologous or allogeneic monocytes. A diminished response to Con A but not to PWM was observed. Whereas RA monocytes were shown to exhibit intact accessory functions, the reduction in response to Con A had to be attributed to an impaired proliferative capacity of the patients' T-cells. This defect was shown as unlikely to be related to the disease itself, but rather to be caused by therapies involving corticosteroids and immunosuppressive drugs.

Adrenal Cortex Hormones↗