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Biomedical subjects

T Salmi

Publications and source records attributed to T Salmi.

At least 19 recordsLinked to original sources
PubMed2006

Mesoporous silica material TUD-1 as a drug delivery system.

For the first time the feasibility of siliceous mesoporous material TUD-1 (Technische Universiteit Delft) for drug delivery was studied. Model drug, ibuprofen, was adsorbed into TUD-1 mesopores via a soaking procedure. Characterizations with nitrogen adsorption, XRD, TG, HPLC and DSC demonstrated the successful inclusion of ibuprofen into TUD-1 host. The amount of ibuprofen adsorbed into the nanoreservoir of TUD-1 material was higher than reported for other mesoporous silica drug carriers (drug/carrier 49.5 wt.%). Drug release studies in vitro (HBSS buffer pH 5.5) demonstrated a fast and unrestricted liberation of ibuprofen, with 96% released at 210 min of the dissolution assay. The drug dissolution profile of TUD-1 material with the random, foam-like three-dimensional mesopore network and high accessibility to the dissolution medium was found to be much faster (kinetic constant k = 10.7) and more diffusion based (release constant n = 0.64) compared to a mesoporous MCM-41 material with smaller, unidirectional mesopore channels (k = 4.7, n = 0.71). Also, the mesoporous carriers were found to significantly increase the dissolution rate of ibuprofen, when compared to the pure crystalline form of the drug (k = 0.6, n = 0.96). TUD-1 was constituted as a potential drug delivery device with fast release property, with prospective applications in the formulation of poorly soluble drug compounds.

Adsorption↗
PubMed2006

Synthesis of Pt modified ZSM-5 and beta zeolite catalysts: influence of ultrasonic irradiation and preparation methods on physico-chemical and catalytic properties in pentane isomerization.

Influence of preparation methods and ultrasound irradiation on physico-chemical and catalytic properties was investigated by synthesizing Pt-ZSM-5 and Pt-Beta catalysts by in-situ and impregnation methods and applying ultrasound irradiation to synthesis gel mixture of ZSM-5 and Beta zeolites. It was concluded from the X-ray powder diffraction patterns of Pt-ZSM-5 and Pt-Beta zeolite catalysts that introduction of Pt by in-situ method and ultrasound irradiation did not influence the structures of ZSM-5 and Beta zeolites. Morphology of ZSM-5 and Beta zeolites were investigated by scanning electron microscopy. SEM micrographs showed that the Pt-ZSM-5-IS-US catalyst synthesized by in-situ method with ultrasound irradiation resulted in smaller crystals of ZSM-5 than Pt-ZSM-5-IS catalyst prepared without ultrasound irradiation. Furthermore SEM micrographs of Pt-Beta-11-IS-US zeolite synthesized using ultrasound irradiation showed much smaller crystals than Pt-Beta-11-IM indicating that ultrasound irradiation had a significant effect on the morphology of Beta zeolite. Conversion of n-pentane and selectivity to iso-pentane over the Pt-ZSM-5-IS-US zeolite catalysts prepared by ultrasound irradiation during in-situ introduction of platinum was higher than the catalysts prepared without the ultrasound irradiation. Furthermore ultrasound irradiated and in-situ synthesized Pt-Beta-11-IS-US catalyst also showed higher selectivity to iso-pentane than Pt-H-Beta-11-IM prepared by impregnation method.

Journal Article↗
PubMed2004

Effect of ultrasound in enantioselective hydrogenation of 1-phenyl-1,2-propanedione: comparison of catalyst activation, solvents and supports.

The enantioselective hydrogenation of 1-phenyl-1,2-propanedione was carried out over Pt/Al2O3, Pt/SiO2, Pt/SF (silica fiber), Pt/C catalysts modified with cinchonidine under ultrasonic irradiation. The initial rate, regioselectivity and enantioselectivity were investigated for different catalyst pretreatments, solvents and ultrasonic powers. The ultrasound effects were very catalyst dependent. The sonication significantly enhanced enantioselectivity and activity of the Pt/SF (silica fiber) catalyst. For the other Pt supported catalysts the reaction rate, enantioselectivity and regioselectivity increased moderately. The choice of solvent influenced the impact of ultrasound effect, namely in mesitylene, which has the lowest vapor pressure, the highest ultrasound enhancement was observed. The effect of sonication on catalysts surface was studied by transmission electron microscopy and scanning electron microscopy (SEM). No significant change in the metal particle size distribution due to sonication was observed. However, in the case of the Pt/SF catalyst, acoustic irradiation induced morphological changes on the catalyst particle surface (SEM), which might be the cause for enhancement of the initial reaction rate and enantioselectivity.

Catalysis↗
PubMed2004

Adolescents with learning disorders have atypical EEG correlation indices. I. Correlation indices during visual discrimination.

OBJECTIVE: To find out whether 14-16-year-old pupils with visual perception disabilities have atypical EEG activation patterns during visual discrimination. METHODS: EEG correlation indices (EEGCIs), based on the waveform characteristics of two EEG signals, were used as measures of slow joint activation of cortical regions during visual discrimination in pupils with visual perception disabilities. RESULTS: During visual discrimination low EEGCIs were seen between the left temporal and both parieto-occipital EEG channels in pupils with visual perception disabilities and in pupils with a poor occupational outcome. The pupils with low performance intelligence and those with difficulties in the visual discrimination task had low EEGCIs within the left hemisphere. The left hemispheric dominance of the findings is suggested to reflect the psychophysiology of the task since visual discrimination demands attention to details (local processing) and is thus supposed to be more strongly represented in the left hemisphere. CONCLUSIONS: During visual discrimination, low EEGCIs were seen in the posterior and left hemispheric regions of pupils with disabilities in visual perception and visual discrimination and with a poor occupational outcome. SIGNIFICANCE: Low EEGCIs in posterior and left hemispheric regions during visual discrimination can to some extent be seen as neurophysiological markers for visual perception disabilities and a poor occupational outcome and imply an increased need for adjustment of the educational curriculum and a need for occupational guidance.

Adolescent↗
PubMed2004

Adolescents with learning disorders have atypical EEG correlation indices. II. Correlation indices during reading.

OBJECTIVE: To find out whether 14-16 year old reading and writing impaired pupils have atypical EEG activation patterns during reading. METHODS: EEG correlation indices (EEGCIs), based on the waveform characteristics of two EEG signals, were used as measurers of slow joint activation of cortical regions during reading in pupils with reading and writing impairment. RESULTS: Reading was associated with high EEGCIs within the right hemisphere in reading and writing impaired pupils. The finding is analogous to the results of an earlier study [Byring, Electroencephalogr. Clin. Neurophysiol. 63 (1986) 1] in boys with spelling disabilities. The activation in the right hemisphere might represent a compensation for a left hemisphere dysfunction in pupils with reading and writing impairment during reading, as suggested by a number of functional neuroimaging studies. This interpretation was corroborated by high EEGCIs especially in those impaired pupils who had a good occupational outcome. CONCLUSIONS: EEGCIs during reading are high within the right hemisphere in pupils with reading and writing impairment. SIGNIFICANCE: High EEGCIs within the right hemisphere during reading might be considered neurophysiological markers for reading and writing impairment.

Adolescent↗
PubMed2004

Utilisation of on-line acoustic irradiation as a means to counter-effect catalyst deactivation in heterogeneous catalysis.

The effect of power ultrasound has been studied in the hydrogenation of 1-phenyl-1,2-propanedione (enantioselective hydrogenation) and linoleic acid (fat hardening). Furthermore the hydrogenation of d-xylose to xylitol and citral to citronellal and citronellol were studied under the influence of acoustic irradiation. We have investigated the effect of on-line acoustic irradiation of these heterogeneously catalysed liquid-gas-solid systems in which it was found to counter-effect catalyst deactivation, increase the reaction velocity and to enhance the selectivity of various heterogeneously catalysed reactions.

Acoustics↗
PubMed2003

Delayed sphincter repair for obstetric ruptures: analysis of failure.

OBJECTIVE: The aim of this study was to examine the clinical results after anterior anal sphincter repair in patients with obstetric trauma and to evaluate possible risk factors for poor outcome. PATIENTS AND METHODS: In years 1990-99 anterior anal sphincter repair for anal incontinence due to obstetric trauma was performed in 39 patients at Helsinki University Central Hospital. Clinical examination with Parks' classification and patients' questionnaire with endoanal ultrasound (EAUS) were done before and after surgery. Pudendal nerve terminal motor latency (PNTML) was measured postoperatively. The median follow-up time after the operation was 22 months (range 2-99). RESULTS: The follow-up results of the patients' questionnaire for 12 patients (31%) were good, for 15 patients (38%) acceptable and for 12 patients (31%) poor. Postoperative EAUS showed sphincter overlap in 28 (72%) patients but a defect was still found in 11 (28%) patients. A defect found on postoperative EAUS correlated with poor clinical result according to Parks' (R = 0.8, P < 0.01) and patients' questionnaire results (R = 0.7, P < 0.01). Patients with poor clinical results (Parks III/IV) were statistically significantly older (median 63 years, range 26-73) than those with favourable results (Parks I/II) (median 45 years, range 27-79) (P < 0.05). Further, the duration of incontinence symptoms correlated with poor functional results (R=0.4, P < 0.05). CONCLUSION: After obstetric trauma anterior anal repair gives acceptable short-term clinical results. EAUS investigation is easy and harmless to perform and should be used pre- and post-operatively. Advanced age, pre-operative signs of perineal descent, long-lasting severe incontinence symptoms and a persistent defect on postoperative EAUS seem to be related to poor clinical result.

Adult↗
PubMed2002

Axial myopathy--an unrecognised entity.

Axial myopathy (AM) is a rare neuromuscular disorder characterised by selective involvement of the spinal muscles with a bent spine and/or drooping head as leading clinical features. We here report the results of clinical, histopathological, MRI, molecular genetics and electrophysiological investigations carried out on six patients affected by pure axial myopathy. Symptoms appeared within an age range of 35 to 56 years. The first symptoms were difficulty in keeping the trunk and head in an upright position. Both bent spine and dropped head were reduced in a supine position. The disease was slowly progressive. Muscle strength examination and muscle imaging revealed involvement of the spinal and neck extensor muscles only. Serum CK was normal to slightly increased. EMG and muscle biopsy specimens obtained from spinal muscles showed an advanced chronic myopathic pattern. We conclude that axial myopathy may be much more common than previously thought, because gradual progression of cervical kyphosis may often be explained as a feature of normal ageing or as an associated sign of several neurological disorders and vertebral degeneration diseases.

Aged↗
PubMed2001

The effect of esophageal pressure monitoring on nasal airway resistance.

OBJECTIVE: Artificial obstruction of nasal airflow has been shown to increase the amount of apneas and arousals. An esophageal catheter inserted through the nasal cavity is used in sleep studies to show intrathoracic pressure variations as sign of obstructive apneas and increased respiratory resistance. This study evaluates the effect of transnasal esophageal catheter on nasal airflow. STUDY DESIGN AND SETTING: Fifty patients with problem snoring referred to our ENT clinic underwent overnight limited sleep study with an esophageal catheter. Nasal airway resistance was measured the following morning with active anterior rhinomanometry. After exclusion of 17 measurements, the results of 33 patients were compared with same parameters obtained earlier without nasal manipulation. RESULTS AND CONCLUSION: The ipsilateral nasal resistance was clearly elevated when measured with a catheter used overnight compared with the control measurement (P < 0.05). However, the combined nasal resistance was not significantly increased in this material with patent nasal airways. In patients with already compromised nasal airflow, the possibility of clinically relevant changes in nasal airflow during catheter use should be taken in account.

Adult↗
PubMed2000

Early signs of critical illness polyneuropathy in ICU patients with systemic inflammatory response syndrome or sepsis.

OBJECTIVE: To evaluate with electromyography the incidence and the time of appearance of neuromuscular abnormality in patients with systemic inflammatory response syndrome (SIRS) and/or sepsis. DESIGN: Follow-up study. SETTING: Intensive care unit of Helsinki University Hospital, Finland. PATIENTS: Nine mechanically ventilated patients with SIRS and/or sepsis. INTERVENTIONS: Electromyography and conduction velocity measurements on the 2nd-5th day after admission to the intensive care unit. MEASUREMENTS AND RESULTS: In all nine patients electromyography revealed signs of neuromuscular abnormality. The means of compound muscle action potential amplitudes of the median and ulnar nerves were decreased. Fibrillation was observed in four patients out of nine. CONCLUSION: Because neuromuscular abnormalities seem to develop earlier than previously reported, electroneuromyography should be used more frequently as a diagnostic test.

Adult↗
PubMed2000

Sleep alterations in juvenile neuronal ceroid-lipofuscinosis.

In juvenile neuronal ceroid-lipofuscinosis (JNCL), sleep disorders are common. The purpose of this study was to investigate the sleep structure of 28 patients with JNCL compared with healthy controls subjects and to clarify the pathophysiology underlying the sleep disturbances in these patients. Each of 28 patients with JNCL (age range = 6-27 years), with or without sleep complaints, underwent one night of polysomnography. Electroencephalographic, electro-oculographic, electromyographic, and electrocardiographic findings were recorded. Sleep was scored and analyzed visually. The sleep parameters of the patients were compared with those of healthy control subjects. In most of the patients, the total sleep time, sleep efficiency, and percentages of rapid eye movement (REM) and non-REM (NREM) stage 2 sleep were significantly decreased, and the percentages of NREM stage 1 and slow-wave sleep and the number of nocturnal awakenings significantly increased. The percentage of NREM stage 1 and the number of awakenings increased with age and clinical stage. Paroxysmal epileptiform activity during light sleep (NREM stages 1-2) and high-amplitude delta-wave activity with intermingled sharp waves during slow-wave sleep were characteristic of the recordings. The present study revealed that in patients with JNCL, sleep is consistently altered.

Adolescent↗
PubMed2000

The effect of physical training on skeletal muscle in patients with chronic heart failure.

BACKGROUND: The improvement of exercise capacity in patients with chronic heart failure (CHF) by physical training has been connected with reversal of the abnormalities in muscle fiber distribution and with the reduced activity of the enzymes of oxidative metabolism in skeletal muscle. However, the change in fiber type distribution induced by training is controversial and in previous studies the activities of the rate-limiting enzymes of the metabolic pathways have not been measured. AIMS: To examine the effect of dynamic training on percentage distribution of muscle fibers, on activities of the rate-limiting enzymes of the metabolic pathways and on electrophysiology in skeletal muscle. METHODS: A total of 27 patients with stable CHF (NYHA class II-III) were randomized to a training (N=12) or a control (N=15) group. The training group exercised on a bicycle ergometer for 30 min three times a week for 3 months using a load corresponding to 50-60% of their peak oxygen consumption. This was followed by a 3-month training period at home according to personal instructions. The control group did not change its physical activities. We studied muscle histology and measured the activities of the rate-limiting enzymes of anaerobic glycolysis (phosphofructokinase, PFK), glycogenolysis (phosphorylase), citric acid cycle (alpha-ketoglurate dehydrogenase, KGDH) and fatty acid oxidation (carnitinepalmitoyl transferase I and II, CPT I and II) from biopsies of the vastus lateralis muscle at baseline and after 3 and 6 months. Muscle strength and strength endurance with surface EMG and macro EMG of the right knee extensors were also determined. RESULTS: Exercise capacity, particularly submaximal, improved in the training group. The activity of PFK rose significantly but that of the other enzymes did not when compared with the change in the controls. Training had no effect on the percentage distribution of slow-twitch and fast-twitch muscle fibers or on capillary density around these fibers in skeletal muscle. Maximum voluntary force, strength endurance and the function of motor units remained unaffected. CONCLUSIONS: Dynamic training results in improved exercise endurance in CHF. In skeletal muscle, the capacity of anaerobic glycolysis is increased but that of the citric acid cycle and fatty acid oxidation is not. Furthermore, the improvement in exercise endurance seems to be independent of changes in the percentage distribution of muscle fibers, capillarity or electrophysiological factors.

Electromyography↗
PubMed2000

Palatal myoclonus and clicking tinnitus in a 12-year-old girl--case report.

Palatal myoclonus is a rare neurological disorder of the soft palate and other oropharyngeal muscles, which causes clicking tinnitus. The latter is audible both to the patient and to an observer. The aetiology may be a brain stem lesion, and it is only rarely that a cause cannot be identified. The condition has been described in adults, but seldom in children. We present here a case of palatal myoclonus with distressing tinnitus in a 12-year-old girl and its successful treatment with electromyography (EMG)-guided injections of Clostridium botulinum toxin.

Anti-Dyskinesia Agents↗
PubMed2000

Craniofacial growth of immature rats following administration of vincristine and doxorubicin.

The aim of the present study was to investigate the possible short-term effect of two anti-neoplastic drugs, vincristine and doxorubicin, on the craniofacial skeleton in young rats. On the basis of findings from pilot experiments, one dose of 0.0375 mg/kg vincristine or 1.0 mg/kg doxorubicin was given parenterally to inbred Long-Evans/Turku rats at 10 or 30 days of age, and followed up until 30 or 50 days, respectively. Some 30-day-old rats received two additional doses of the drugs, 3 and 6 days after the first injection. Controls were given physiological saline. A total of 310 rats were used: 40 for the pilot study, 180 medicated, and 90 control animals for the experiment itself. The weights of the rats were recorded, a number of craniofacial dimensions were measured, and the neurocranial volume determined in the case of the most severely affected rats. The weight gain of the younger rats was retarded, as was that of the older rats that received repeated drug injections. Most dimensions of the craniofacial skeleton were significantly smaller in the vincristine-treated young animals, and following multiple injections of vincristine or doxorubicin also in the older ones when compared with the controls. Contrary to the general pattern, the measurements of the foramen magnum increased in the older rats, a feature associated with the decrease in brain cavity volume observed in those that received vincristine. These findings indicate that anti-neoplastic agents can have a short-term adverse effect on the craniofacial growth and that the morphological changes are differential, rather than uniform.

Age Factors↗
PubMed1998

Long-term results from a phase II study of single agent paclitaxel (Taxol) in previously platinum treated patients with advanced ovarian cancer: the Nordic experience.

BACKGROUND: Owing to the wide spread perception of a possible benefit from paclitaxel in the second-line situation the Nordic Gynecologic Oncology Group (NGOG) conducted two prospective phase II studies of paclitaxel single agent treatment (175 mg/m2, three-hour i.v. infusion with standard pre-medication every third week) in patients with relapsing or progressing epithelial ovarian cancer following platinum. PATIENTS AND METHODS: Between 1992-1994 138 patients in total were enrolled of whom 136 received paclitaxel and were included in the toxicity and survival analysis, while 112 were evaluable for response. RESULTS: The overall response rate (CR + PR) was 28% with 16 patients achieving a CR (14%). The estimated median (range) time to progression was 4.1 (0.7-60.7) months. The projected four-year overall survival was 7%, with a median (range) of 9.6 (0.3-60.7) months. A multivariate logistic regression analysis showed that platinum resistance, and WHO performance status at baseline, independently correlated with survival at all three time points (median survival time 9.6, 18, and 24 months). Patients with platinum sensitive tumors and WHO performance status 0 had a median survival of 25.6 months compared to 7.0 months for the rest of the patients (P < or = 0.0001). No serious toxicity was registered. CONCLUSION: Paclitaxel could safely be administered in an outpatient setting using this schedule. Patients with platinum sensitive tumors and a good performance status were most likely to survive. However, these patients are also most likely to respond to re-treatment with a platinum compound. With reference to the reasonably good tumor control and limited toxicity observed in this study, we conclude that paclitaxel single agent therapy is a viable option in the salvage situation, which in some patients can give long-lasting responses. However, although responses can be induced in a significant number of patients, the survival figures remain poor.

Adult↗
PubMed1998

Reproducibility of oximetry with a static charge-sensitive bed in evaluation of obstructive sleep apnoea.

The reproducibility of overnight polygraphic recording with oximetry, the use of a static charge-sensitive bed (SCSB), thermistors and a body position sensor was assessed in diagnosing obstructive sleep apnoea syndrome (OSAS). Forty-six patients with a clinical suspicion of OSAS underwent a repeat recording. No treatment for OSAS and no change in patient characteristics was allowed between duplicate nights. Between repeated recordings significant correlations were found for ODI4, time spent at SaO2 < 90% and the mean nadir SaO2. Good agreement was found in concordance of classification of ODI4, time spent at SaO2 < 90% and body movements. The combination of oximetry, thermistors, SCSB and body position sensor has a good reproducibility as an affordable screening method in the evaluation of OSAS.

Adolescent↗
PubMed1997

Molecular mechanism of a mild phenotype in coagulation factor XIII (FXIII) deficiency: a splicing mutation permitting partial correct splicing of FXIII A-subunit mRNA.

Congenital factor XIII (FXIII) deficiency is potentially a severe bleeding disorder, but in some cases, the symptoms may be fairly mild. In this study, we have characterized the molecular mechanism of a mild phenotype of FXIII A-subunit deficiency in a Finnish family with two affected sisters, one of whom has even had two successful pregnancies without regular substitution therapy. In the screening tests for FXIII deficiency, no A-subunit could be detected, but by using more sensitive assays, a minute amount of functional A-subunit was seen. 3H-putrescine incorporation assay showed distinct FXIII activity at the level of 0.35% of controls, and also the fibrin cross-linking pattern in the patients clotted plasma showed partial gamma-gamma dimerization. In Western blot analysis, a faint band of full-length FXIII A-subunit was detected in the patients' platelets. The patients have previously been identified as heterozygotes for the Arg661 --> Stop mutation. Here we report a T --> C transition at position +6 of intron C in their other allele. The transition affected splicing of FXIII mRNA resulting in low steady state levels of several variant mRNA transcripts. One transcript contained sequences of intron C, whereas two transcripts resulted from skipping of one or two exons. Additionally, correctly spliced mRNA lacking the Arg661 --> Stop mutation of the maternal allele could be detected. These results demonstrate that a mutation in splice donor site of intron C can result in several variant mRNA transcripts and even permit partial correct splicing of FXIII mRNA. Further, even the minute amount of correctly processed mRNA is sufficient for producing protein capable of gamma-gamma dimerization of fibrin. This is a rare example of an inherited functional human disorder in which a mutation affecting splicing still permits some correct splicing to occur and this has a beneficial effect to the phenotype of the patients.

DNA Mutational Analysis↗