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Biomedical subjects

P Vuorinen

Publications and source records attributed to P Vuorinen.

At least 19 recordsLinked to original sources

Mycobacterium tuberculosis complex is not detected by DNA amplification assay in sputum specimens of patients with lung scars due to past pulmonary tuberculosis.

OBJECTIVE: To evaluate detection of false-positive sputum amplification assay results in former tuberculosis patients with residual pulmonary scars. DESIGN: A total of 268 sputum specimens from 25 war veterans with tuberculosis during 1940-1959, without adequate chemotherapy, and 19 subjects effectively treated for cavitary tuberculosis during 1980-1993 were tested by smear, culture and DNA amplification, as were 34 controls with no history of tuberculosis or pulmonary scars. RESULTS: No active tuberculosis cases were identified. All specimens were negative on DNA amplification and smear. Eight specimens from six subjects were positive on culture, revealing atypical mycobacteria. CONCLUSION: No genetic Mycobacterium tuberculosis material in sputum specimens of subjects with residual lesions of pulmonary tuberculosis and no false-positive amplification results were detected.

Adult↗

Normal CSF neuron-specific enolase and S-100 protein levels in patients with recent non-complicated tonic-clonic seizures.

PURPOSE: Increased concentrations of the nervous-system-specific proteins neuron-specific enolase (NSE) and S-100 protein (S-100) have been measured with lesions in the CNS. Elevated levels of serum NSE (s-NSE) have been found in status epilepticus, but also after single epileptic seizures. Because larger studies addressing cerebrospinal fluid (CSF) levels of NSE or S-100 have not been performed, we measured CSF NSE and S-100 after tonic-clonic seizures to search for evidence of neuronal and glial damage. METHODS: 22 consecutive patients with single, previously undiagnosed and untreated tonic-clonic seizures were studied. Serum and CSF samples were collected within 24 h after seizure. 18 serum and CSF samples were measured from a control group. RESULTS: The mean CSF NSE was 8.9 ng/ml (range 0-28 ng/ml) and s-NSE 8.2 ng/ml (range 5-15 ng/ml) in the patient group. The mean concentrations in the control group were 13.1 ng/ml (range 3-24 ng/ml) and 8.0 ng/ml (range 5-12 ng/ml) respectively. The mean CSF S-100 was 3.17 microg/l (range 1.45-7.02 microg/l) and serum S-100 0.05 microg/l (range 0-0.32 microg/l), and in controls 3.19 microg/l (range 1.52-5.13 microg/l) and 0.08 microg/l (range 0-0.28 microg/l). CONCLUSION: There were no significant differences between the mean concentrations of NSE or S-100 in CSF and serum between the epileptic group and controls. These results do not confirm the previous observation of elevated NSE-levels after tonic-clonic seizures, which argues against neuronal or glial damage after uncomplicated tonic-clonic seizures in unmedicated patients.

Adolescent↗

Evaluation of commercial DNA and rRNA amplification assays for assessment of treatment outcome in pulmonary tuberculosis patients.

To evaluate the clinical utility of the DNA and RNA amplification assays in monitoring the efficacy of tuberculosis treatment, 416 sputum specimens collected from 15 smear-positive tuberculosis patients during and after treatment were tested for the presence of Mycobacterium tuberculosis by microscopy, culture, polymerase chain reaction (Cobas Amplicor Mycobacterium Tuberculosis Test; Roche, Switzerland) and AMTDT 2 (Amplified Mycobacterium Tuberculosis Direct Test; Gen Probe, USA). All patients were cured, and no relapses were found. Results of both amplification assays re mained positive longer than results of either smear or culture. Four of 15 patients were positive by polymerase chain reaction and/or AMTDT 2 at the completion of treatment. Subsequent sputum specimens from these patients converted to negative within 2.5-12 months. The present data do not support the routine use of qualitative amplification assays for monitoring the treatment response of smear-positive tuberculosis patients.

Adult↗

Comparison of a transcription-mediated amplification assay and polymerase chain reaction for detection of Chlamydia trachomatis in first-void urine.

The performance of a commercial transcription-mediated amplification (TMA) assay (Gen-Probe Amplified Chlamydia trachomatis Assay; Gen-Probe, USA) was compared with that of the Roche Cobas Amplicor CT/NG polymerase chain reaction (PCR) (F. Hoffmann-La Roche, Switzerland) for detection of Chlamydia trachomatis in urine specimens. First-void urine specimens were collected from 658 patients: 320 men and 338 women. The results of the two tests were identical for 650 (98.8%) of the 658 patients. Among them, the test results were uniformly positive for 72 patients: 39 men and 33 women. In the cases in which the initial results of TMA assay and PCR were discrepant the specimens were reanalyzed and tested by an alternative TMA assay and a major outer membrane protein-based PCR. After analysis of discrepant results. 74 specimens (11.2%) were considered positive. All positive results were correctly identified by TMA assay, whereas PCR gave two false-negative and six false-positive results.

Chlamydia Infections↗

Induction of beta-2-microglobulin release in vitro by chronic lymphocytic leukaemia cells: relation to total protein synthesis.

The in vitro production of beta2-M by B-CLL cells from 27 patients was investigated. In all cases, low spontaneous beta2-M release was observed. The production of beta2-M was enhanced to various extents when induced with 13 different stimulants and their combinations including IL-2, TNFalpha, SAC and TPA. Beta2-M release was 3.8-fold (range from 1.9 to 9.2-fold) in cultures stimulated with TPA (10 ng/ml), compared with the spontaneous release, and even faster if TNFalpha or IL-2 were added. A strong correlation was revealed between beta2-M production and the total protein synthesis of leukaemic cells when the latter was assessed using 14C-L-leucine incorporation. Hence, both beta2-M release and leucine incorporation are promising activation markers for CLL B-lymphocytes.

Aged↗

Detection of Mycobacterium tuberculosis complex in sputum specimens by the automated Roche Cobas Amplicor Mycobacterium Tuberculosis Test.

Three hundred twenty-four sputum specimens from 151 patients with suspected active pulmonary tuberculosis were tested for the presence of the Mycobacterium tuberculosis complex with auramine fluorochrome stain and automated PCR assay (Roche Cobas Amplicor Mycobacterium Tuberculosis Test [MTB]). The results were compared with those of the conventional Löwenstein-Jensen tube culture and the BACTEC radiometer liquid culture. A total of 76 specimens from 32 patients were culture positive for M. tuberculosis. In addition, 37 specimens from 15 patients were smear and culture positive for other Mycobacterium species but negative by the present nucleic acid amplification method and thus were not included in the comparison. Compared with culture, the sensitivities, specificities, and positive and negative predictive values for acid-fast smear were 67, 98, 93, and 91% and those for the Cobas Amplicor MTB were 83, 99, 97, and 95%, respectively. When three consecutive sputum specimens per patient could be obtained, the sensitivity of the Cobas Amplicor MTB improved to 91%, whereas the sensitivity of the acid-fast smear remained unchanged.

Adult↗

Nitric oxide-releasing oxatriazole derivatives inhibit human lymphocyte proliferation by a cyclic GMP-independent mechanism.

Two novel nitric oxide (NO)-releasing oxatriazole derivatives, GEA 3162 and GEA 3175, and an earlier known NO donor, S-nitroso-N-acetylpenicillamine (SNAP), inhibited cell proliferation and enhanced cGMP production in a concentration-dependent manner in human lymphocytes activated by lectin mitogen concanavalin A (ConA). The possible mediator role of cGMP in the antiproliferative action of NO donors was tested by pharmacological means. An inhibitor of guanylate cyclase, 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one, inhibited NO donor-induced cGMP production, whereas the antiproliferative action of NO donors remained unaltered. Phosphodiesterase inhibitors zaprinast and 3-isobutyl-1-methylxanthine potentiated and prolonged NO donor-induced increase in the concentrations of cGMP but did not enhance the antiproliferative action of NO donors. In addition, two analogs of cGMP, 8-bromo-cGMP and a more cell-permeable compound, 8-p-chlorophenylthio-cGMP, did not inhibit ConA-stimulated lymphocyte proliferation when used in concentrations of up to 300 microM. At millimolar concentrations, 8-bromo-cGMP had a moderate inhibitory action. These results suggest that nitric oxide-releasing oxatriazole derivatives inhibit proliferative responses in human lymphocytes by a cGMP-independent manner.

1-Methyl-3-isobutylxanthine↗

Inhibition of human lymphocyte proliferation by nitric oxide-releasing oxatriazole derivatives.

The effects of novel nitric oxide (NO)-releasing oxatriazole derivatives GEA 3162 and GEA 3175 were studied on cell proliferation and cGMP synthesis in human peripheral blood mononuclear cells stimulated with a lectin mitogen concanavalin A. GEA 3162 (1-30 microM) and GEA 3175 (3-30 microM) inhibited mononuclear cell proliferation in a dose-dependent manner being more potent than the earlier known NO-donor S-nitroso-N-acetylpenicillamine. The inhibitory action was more pronounced when submaximally stimulating concentrations of concanavalin A (0.1 and 1 microg/ml) were used and no inhibition was seen when concanavalin A concentrations were increased up to 10 microg/ml. The antiproliferative concentrations of GEA 3162, GEA 3175 and S-nitroso-N-acetylpenicillamine induced a rapid and transient increase in cGMP production in mononuclear cells cultured in the presence of concanavalin A. Both the antiproliferative action and the increased cGMP production were attenuated when red blood cells were added into the cultures indicating that NO is responsible for both of these actions. An analogue of cGMP, 8-bromo-cGMP (0.1-3 mM) reduced concanavalin A-induced proliferation in a dose-dependent manner suggesting that cGMP may be involved in the antiproliferative action of NO-donors. NO-releasing compounds have immunosuppressive actions which offer therapeutic possibilities and should be kept in mind as potential adverse events when these compounds are used in other indications.

Cell Division↗

3-Morpholino-sydnonimine-induced suppression of human neutrophil degranulation is not mediated by cyclic GMP, nitric oxide or peroxynitrite: inhibition of the increase in intracellular free calcium concentration by N-morpholino-iminoacetonitrile, a metabolite of 3-morpholino-sydnonimine.

This study was designed to clarify the mechanism of the inhibitory action of a nitric oxide (NO) donor 3-morpholino-sydnonimine (SIN-1) on human neutrophil degranulation. SIN-1 (100-1000 microM) inhibited degranulation (beta-glucuronidase release) in a concentration-dependent manner and concomitantly increased the levels of cGMP in human neutrophils in suspension. However, further studies suggested that neither NO nor increase in cGMP levels were mediating the inhibitory effect of SIN-1 on human neutrophil degranulation because 1) red blood cells or 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl added as NO scavengers did not inhibit the effect; 2) inhibitors of cGMP synthesis (methylene blue) or phosphodiesterases (3-isobutyl-1-methylxanthine) did not produce changes in cell function correlating with the changes in cGMP. SIN-1 releases both nitric oxide and superoxide, which together form peroxynitrite. Chemically synthesized peroxynitrite (1-100 microM) did not inhibit, but at high concentrations (1000-2350 microM), it potentiated FMLP-induced beta-glucuronidase release from neutrophils. Thus formation of peroxynitrite from SIN-1 does not explain its inhibitory effects on neutrophil degranulation. The NO-deficient metabolite of SIN-1, SIN-1C (330-1000 microM) inhibited human neutrophil degranulation in a concentration-dependent manner similar to that of SIN-1 and reduced the increase in intracellular free calcium induced by N-formyl-L-methionyl-L-leucyl-L-phenylalanine. C88-3934 (330-1000 microM), another NO-deficient sydnonimine metabolite, also inhibited human neutrophil degranulation. In conclusion, the data shows that the NO-donor SIN-1 inhibits human neutrophil degranulation in a cGMP-, NO-, and peroxynitrite-independent manner, probably because of the formation of more stable active metabolites such as SIN-1C. The results demonstrate that studies on the role of NO and/or peroxynitrite carried out with SIN-1 and other NO-donors should be carefully re-evaluated as to whether the effects found are really attributable to NO or peroxynitrite and that in future studies, it will be crucial to carry out control experiments with the NO-deficient metabolites in any studies with sydnonimine NO-donors.

Acetonitriles↗

Comparison of manual Amplicor PCR, Cobas Amplicor PCR, and LCx assays for detection of Chlamydia trachomatis infection in women by using urine specimens.

We compared the Roche Amplicor PCR, Roche Cobas Amplicor PCR, and Abbott LCx assays by using urine specimens for the detection of Chlamydia trachomatis infections in a female population. First-catch urine and endocervical swab specimens were collected from a total of 442 patients. Urine specimens were tested by the manual Roche Amplicor PCR, the automatic Roche Cobas Amplicor PCR, and the Abbott LCx assays as instructed by the manufacturers. For the Cobas Amplicor PCR, the internal control protocol was used for every specimen to reveal the presence of polymerase inhibitors. Cell culture of cervical specimens was used as a reference method. Of 442 patients, 50 (11.3%) were confirmed to have chlamydial infection. The diagnostic sensitivity and specificity of cell culture with cervical swab specimens were 88 and 100%, respectively. With urine specimens the sensitivity and specificity for the manual Amplicor PCR assay were 100 and 99.7%, respectively; those for the automatic Cobas Amplicor PCR assay were 94 and 99.2%, respectively; and those for the LCx assay were 94 and 100%, respectively. Thus, all amplification methods with urine specimens proved to be highly sensitive and specific for the detection of C. trachomatis infection in women. No statistically significant differences in the test performances could be demonstrated for specimens from this population. All three amplification techniques with urine specimens proved to be superior to cell culture with cervical swab specimens in diagnosing C. trachomatis infections in women.

Chlamydia Infections↗

Evaluation of the Gen-Probe Chlamydia trachomatis transcription-mediated amplification assay with urine specimens from women.

We evaluated the Gen-Probe Chlamydia trachomatis transcription-mediated amplification (TMA) assay with urine specimens for the detection of C. trachomatis infections in women. The novel test, based on the isothermal amplification of chlamydial RNA, was compared with the Roche Amplicor PCR with urine and cell culture with endocervical specimens. First-catch urine and endocervical swab specimens were collected from a total of 561 patients, of whom 70 (12.3%) were confirmed to have chlamydial infection. The diagnostic sensitivity and specificity of TMA with urine were 91.4 and 99.6%, respectively, and those of Amplicor PCR were 97.1 and 99.8%, respectively. By repeated analysis of the specimens with discrepant results, the sensitivity of TMA could be increased to 99%, indicating that some methodological improvements in the assay are still to be expected. The sensitivity of PCR could be increased to 100% by the elimination of DNA polymerase inhibitors in a repeated analysis. The sensitivity and specificity of cell culture with cervical specimens were 85.7 and 100%, respectively. The results indicate that TMA with urine specimens from women is a sensitive and specific assay for the detection of C. trachomatis, providing a new noninvasive technique for the screening of chlamydial infections in women.

Bacteriological Techniques↗

Mode of cytostatic action of mesoionic oxatriazole nitric oxide donors in proliferating human hematopoietic cells.

The cytopathological effects of the novel nitric oxide (NO)-releasing, mesoionic 3-aryl-substituted oxatriazole-5-imine derivatives GEA 3162 and GEA 3175, and a reference NO donor SIN-1 were investigated in proliferating human hematopoietic cells. The GEA compounds (10-50 microM) induced rapid surface changes, which progressed as peculiar deep indentations and strictures in human leukemic T cells (MOLT-3) in 30 min. An excess of red cells partially prevented these surface changes. GEA 3162-treated MOLT-3 cells became permeable to ethidium bromide and lost their ability to be stained by acridine orange after 5 h of exposure. GEA 3162 and GEA 3175 suppressed thymidine and uridine incorporation in a dose-dependent manner, reflecting the inhibition of DNA and RNA synthesis respectively. In addition, the GEA compounds inhibited the growth of human bone marrow stem cells, CFU-GM colonies being more susceptible to the cytostatic action than BFU-E. The reference compound SIN-1 had comparative cytostatic effects at ten times greater concentrations (500 microM). We conclude that NO-releasing mesoionic oxatriazole derivatives have cytostatic action against human malignant and non-malignant hematopoietic cells, supporting the value of NO-releasing and NO-inducing compounds as anti-cancer agents.

Antineoplastic Agents↗

Nitric oxide as a regulator of prostacyclin synthesis in cultured rat heart endothelial cells.

The effects of nitric oxide (NO) and its second messenger cyclic guanosine monophosphate (cGMT) on prostacyclin (PGI2) synthesis were studied in cultured rat heart endothelial cells using three different non-enzymatic nitric oxide releasing substances as well as inhibitors of nitric oxide synthase and of soluble guanylate cyclase. Production of prostacyclin, measured as 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), was stimulated up to 1.7 fold in endothelial cells treated with the NO donors SIN-1 (3-morpholino sydnonimine), GEA 3162 (3-aryl-substituted oxatriazole imine) and GEA 3175 (3-aryl-substituted oxatriazole sulfonyl), chloride). In each case the synthesis of cGMP increase as much as 40-100 fold. An inhibitor of NO synthase, NG-nitro-L-arginine methyl ester (L-NAME), decreased the basal production of 6-keto-PGF1 alpha in non-stimulated endothelial cells, an effect that could be reversed by the NO donors SIN-1, GEA 3162 and GEA 3175. cGMP formation in the L-NAME treated endothelial cells was unaltered. The guanylate cyclase inhibitors, methylene blue (100 mumol/l) and LY83583 (100 mumol/l), caused a 1.5-10 fold increase in 6-keto-PGF1 alpha production while NO-donor-stimulated endothelial cGMP production was decreased by 10 to 90%. However, when SIN-1 was used as a stimulant, LY83583 had no significant effect on the production of cGMP. These findings support the hypothesis that NO stimulates prostacyclin production directly by activating cyclooxygenase. The results also suggest that NO could have an indirect effect on prostacyclin production via cGMP.

6-Ketoprostaglandin F1 alpha↗

Nitric oxide-donating properties of mesoionic 3-aryl substituted oxatriazole-5-imine derivatives.

1. The nitric oxide (NO)-releasing properties of two new mesoionic 3-aryl substituted oxatriazole-5-imine derivatives (GEA 3162 and GEA 3175) were characterized and compared with the known NO-donors 3-morpholino-sydnonimine (SIN-1) and S-nitroso-N-acetylpenicillamine (SNAP). 2. GEA 3162, GEA 3175, SIN-1 and SNAP inhibited adenosine 5'-diphosphate-induced platelet aggregation (IC50 values 0.18, 0.39, 3.73 and 2.12 microM, respectively). All four compounds induced a dose-dependent and more than 4 fold increase in cyclic GMP in platelets. The increase in cyclic GMP concentration was potentiated more than 1.5 fold by a phosphodiesterase inhibitor, zaprinast (10 microM) and inhibited 38-97% by oxyhaemoglobin (10-45 microM). 3. All of the four compounds studied converted oxyhaemoglobin to methaemoglobin and formed a paramagnetic NO-haemoglobin complex. All but GEA 3175 formed nitrite and nitrate in phosphate buffer. During a 40 min incubation, GEA 3162, SIN-1 and SNAP (100 microM) produced 50-70 microM NO2- + NO3- as determined by high performance liquid chromatography. The release of NO and NO2 by GEA 3175 was increased 140 fold in the presence of human plasma (0.14 and 19.7 ppb in the absence and presence of 1% human plasma, respectively) as analyzed by ozone chemiluminescence. 4. The results suggest that the mesoionic 3-aryl substituted oxatriazole-5-imine derivatives GEA 3162 and GEA 3175 as well as SIN-1 and SNAP release nitric oxide.

Blood Platelets↗

Detection of Chlamydia trachomatis infections in women by Amplicor PCR: comparison of diagnostic performance with urine and cervical specimens.

We used the Roche Amplicor PCR assay to compare urine and cervical swabs as sample material in the detection of Chlamydia trachomatis causing genital infections. The diagnostic performance of Amplicor PCR was compared with that of cell culture and the Gen-Probe PACE 2 assay with cervical specimens. If discrepant from other results, the specimens negative by PCR were diluted and reanalyzed to reveal PCR inhibitors. Of 666 patients, 39 (5.9%) were confirmed to have chlamydial infection. The respective sensitivity and specificity of Amplicor PCR were as follows: urine specimens, 82.0 and 99.7%; cervical specimens, 82.0 and 99.8%. Those for cell culture with cervical specimens were 84.6 and 100%. For the Gen-Probe PACE 2 assay, the sensitivity and specificity with cervical specimens were 79.5 and 100%, respectively. Without the effect of PCR inhibitors, the sensitivity of PCR with urine would have been 97.4%. Provided that the problems currently caused by inhibitors will be solved, the Amplicor PCR assay with urine specimens offers a tempting alternative for the diagnosis of C. trachomatis infection in women.

Bacteriological Techniques↗

Inhibition of human neutrophil function by tolfenamic acid involves inhibition of Ca2+ influx.

The present work was designed to study the pharmacological control of the receptor-mediated activation of human neutrophils by tolfenamic acid (2(-)[(3-chloro-2-methylphenyl)-amino]benzoic acid). Tolfenamic acid inhibited in a concentration-dependent manner the degranulation response and Ca2+ influx in neutrophils activated either by the chemotactic peptide fMLP (N-formyl-methionyl-leucylphenylalanine) or Ca2+ ionophore A23187 (calcimycin). When fMLP was used to activate neutrophils, tolfenamic acid (30 microM) reduced Ca2+ influx by 50% and degranulation by 20%. A23187-triggered Ca2+ influx and degranulation were inhibited by 60% and 40%, respectively, by 30 microM tolfenamic acid. Tolfenamic acid did not inhibit the release of Ca2+ from intracellular stores induced either by fMLP or A23187. To confirm the inhibition of receptor-mediated cation influx by tolfenamic acid, the agonist induced Mn2+ influx was studied in Ca2+ free medium. Tolfenamic acid (10-30 microM) reduced fMLP-stimulated Mn2+ influx in neutrophils in a concentration-dependent manner. The simultaneous Ca2+ release from intracellular stores was not affected. Protein kinase C activity in sonicated human neutrophils and the purified enzyme from rat brain were inhibited by the protein kinase inhibitor H-7 (1-(5-isoquinolinylsulfonyl)-2-methylpiperazine) but not by tolfenamic acid. Both failed to inhibit neutrophil degranulation induced by phorbol myristate acetate, a protein kinase C activator. Tolfenamic acid (100 microM) increased the cellular cAMP levels up to 1.3-fold in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine. No effects on cellular cGMP levels were found.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗