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Biomedical subjects

T Kallio

Publications and source records attributed to T Kallio.

29 records · Page 2Linked to original sources
PubMed1993

Distraction bone healing.

Bone formation by distraction was studied using three different experimental models: (1) Physeal distraction of the sheep radius was performed in 20 animals. (2) Distraction after osteotomy of the radius was carried out in 39 sheep. (3) Mandibular distraction after osteotomy was performed in 17 sheep. Formation of the organic matrix and osteogenesis were studied by radiographic, histologic, and biochemical methods as well as by electron microscopy. The mode of osteogenesis was essentially similar in all of these distraction models. Bone formation was preceded by organization of the collagenous matrix in the distraction area. In the beginning of the distraction, the gap was composed of a heterogeneous cell population, with large polymorphic fibroblast-like cells. The cells in the central part differentiated into fibroblasts, which remained functionally active as long as distraction proceeded. During physeal distraction, bone formed from the epiphyseal and metaphyseal sides as well as from the surrounding perichondrium. Also, in osteotomy distraction of both tubular bone and mandible, bone formed centripetally from the osteotomized bone ends toward the center of the gap. The organic matrix was composed almost solely of Type I collagen in the earliest stages, suggesting that the mode of osteogenesis differs from bone repair by fracture callus. The structure of the distracted segment was mainly lamellar trabecular. Corticalization of the lengthened bone segment occurred gradually after several months.

Animals↗
PubMed1991

Assessment of blood echogenicity as an alternative measure to erythrocyte sedimentation rate.

OBJECTIVE: To determine the relation between erythrocyte sedimentation rate and blood echogenicity and whether measurement of erythrocyte sedimentation rate could be replaced by measurement of blood echogenicity in monitoring acute phase reactions. DESIGN: Simultaneous measurement of echogenicity of flowing blood and erythrocyte sedimentation rate in blood samples and comparison of results. SETTING: A radiological department in a university hospital. SUBJECTS: 83 patients with a suspected venous thrombosis and 36 healthy volunteers. MAIN OUTCOME MEASURES: Correlations between the erythrocyte sedimentation rate, packed cell volume, and echogenicity of flowing blood. RESULTS: Blood echogenicity correlated poorly with the packed cell volume, but strongly correlated with the erythrocyte sedimentation rate (when the packed cell volume was within reference limits) (correlation coefficient = 0.73). Blood samples with a greatly raised erythrocyte sedimentation rate were highly echogenic. Only one of the 30 samples with an erythrocyte sedimentation rate below 10 mm in first hour had a higher echogenicity than the least echogenic sample of the 19 with a sedimentation rate above 30 mm in first hour. CONCLUSIONS: Echogenicity of flowing blood correlates with the erythrocyte sedimentation rate and its measurement may compete with conventional methods for evaluating the long term changes in acute phase reactions. Also, it has the added advantage that non-invasive in vivo measurements of blood echogenicity may become possible.

Acute-Phase Reaction↗
PubMed1990

The effect of naftidrofuryl on red blood cell aggregation detected in vitro with ultrasound.

Red blood cell aggregates are mainly responsible for the echogenicity of flowing blood. Thus, ultrasound can be used to observe the degree of red blood cell aggregation in slow flow conditions. We quantified blood echogenicity to study aggregation tendency of red blood cells in blood of patients with claudication, patients with suspected venous thrombosis, and normal volunteers without and with in vitro addition of naftidrofuryl (10(-6) M). Normal volunteers showed lower original echogenicity than any group of patients, and claudication patients showed the highest echogenicity. Naftidrofuryl caused a fall in mean echogenicity in all groups, and its effect was pronounced on blood samples with a high original echogenicity.

Aged↗
PubMed1989

The in vitro echogenicity of flowing blood in patients with vascular disease and the effect of naftidrofuryl.

Blood echogenicity was measured in four patient groups with circulatory disturbances (myocardial infarction, stroke, claudication, and deep venous thrombosis) at hospital admission and one week later. The recording was done by an A-mode ultrasonic method at three shear rates down to 4.1 s-1. The rheological effects of adding an anti-aggregatory drug, naftidrofuryl, was tested in vitro at concentrations ranging from 10(-8)-10(-6) M. Echogenicity was lowest in blood from healthy volunteers and significantly greater in blood from patients with claudication. The in vitro addition of naftidrofuryl significantly lowered the echogenicity of blood samples taken from patients with venous thrombosis in the lower extremities. The authors suggest that increased blood echogenicity, which can be pharmacologically manipulated, may be a nonspecific indicator of disease.

Blood Sedimentation↗
PubMed1989

The effect of radiographic contrast media on ultrasonically detectable red blood cell aggregation in vitro.

We investigated the effect of radiographic contrast media (RCM) on red blood cell (RBC) aggregation by analyzing echogenicity of flowing blood before and after the addition of 2%, 20%, 50% or 95% volume of undiluted meglumine diatrizoate, iohexol, sodium meglumine ioxaglate, or iopamidol and equiosmolar volume concentration of saline. This was done both by stepwise increasing the concentration with minimal mixing and by stepwise decreasing the concentrations with more efficient mixing. All contrast media caused a drop in blood echogenicity after a proper mixing when compared with saline addition. After minimal stirring, both meglumine diatrozoate and iohexol caused a significant increase in blood echogenicity at volume concentrations over 50%. The paper demonstrates that earlier findings of both increased and decreased RBC aggregation following exposure to RCM can be reproduced and that the result depends on experimental setup. In diatrizoate and iohexol RBC aggregates disappear after mixing (increasing the shear rate) or when the RCM/blood mixture is diluted. After dispersement, the abnormal RBC aggregates will not reform.

Blood↗
PubMed1988

A new ultrasonic technique for quantifying blood echogenicity.

The echogenicity of blood varies with the conditions of flow. This study introduces a new technique for quantifying blood echogenicity and includes digitalization of the signal from an A-mode ultrasound scanner, integration, subtraction, and computer analysis of the signal. Shear rate (directly proportional to velocity) had an inverse relationship to the blood echogenicity. Hemodilution with Ringer's solution and with low-molecular-weight dextran 1 decreased blood echogenicity, whereas the addition of a macromolecular protein (dextran 70) increased blood echogenicity. This technique makes possible a quantitative analysis of the factors affecting blood echogenicity.

Blood Circulation↗
PubMed1984

Accumulation of pyrophosphate correlates with the increased level of nucleoside triphosphates in Escherichia coli.

We measured the concentration of nucleoside triphosphates and inorganic pyrophosphate in Escherichia coli in conditions where nucleotide synthesis or nucleic acid synthesis was inhibited. The inhibitors that brought about an accumulation of some of the four ribonucleoside triphosphates also increased the pyrophosphate level. In a pyrimidine auxotrophic strain uracil starvation led to simultaneous accumulation of ATP and pyrophosphate, and they both rapidly returned to normal level when starvation was relieved. These results indicate the possible involvement of pyrophosphate in the reactions leading to the accumulation of nucleoside triphosphates.

Adenosine Triphosphate↗
PubMedDate not supplied

The handicap code of the ICIDH, adapted for children aged 6-7 years. Classification Group of the Nordic Neuropediatric Association.

The handicap section of the ICIDH was developed with the experience of adults in mind. In its original form the H Code is not immediately applicable to young children with disabilities. The Classification Group of the Nordic Neuropediatric Association has developed an adaptation of the H Code for use in children aged 6-7 years, and the adaptation is presented in this paper.

Activities of Daily Living↗
PubMedDate not supplied

High peritoneal permeability predisposes to hepatic steatosis in diabetic continuous ambulatory peritoneal dialysis patients receiving intraperitoneal insulin.

OBJECTIVE: To evaluate hepatic fat accumulation in diabetic patients taking intraperitoneal or subcutaneous insulin treatment during continuous ambulatory peritoneal dialysis (CAPD). DESIGN: Cross-sectional study. SETTING: Tertiary-care university hospital. PATIENTS: We studied 16 patients with diabetic end-stage renal disease currently treated with CAPD. Median age was 42 years (range: 34-70 years), duration of diabetes was 27.5 years (range: 17-39 years), and duration of CAPD was 16.5 months (range: 2-59 months). OUTCOME MEASURES: Ultrasound measures of liver steatotic area and thickness, peritoneal equilibration test (PET), weekly Kt/V urea, protein catabolic rate (PCR), hemoglobin A1c (HbA1c), lipoproteins, alanine aminotransferase, alkaline phosphatase, insulin dose, and dialysate glucose load. RESULTS: Focal hepatic fat accumulation was found. The location of steatosis was subcapsular; a negligible amount was periportal. Hepatic subcapsular steatosis was present in 7 of 8 patients taking insulin intraperitoneally and in 0 of 8 patients taking insulin subcutaneously. The maximal thickness of subcapsular steatosis correlated directly with peritoneal transport rate (2-hour dialysate-to-plasma creatinine ratio in PET, r = 0.80, p < 0.05) and inversely with PCR (r = -0.82, p < 0.05). The area of the lesions correlated directly with body weight (r = 0.80, p < 0.05) and inversely with weekly Kt/V urea (r = -0.90, p < 0.01). CONCLUSIONS: Intraperitoneal insulin, together with glucose-based peritoneal dialysate, induces hepatic subcapsular steatosis. The amount of hepatic subcapsular steatosis increases when peritoneal transfer rate and body weight are high.

Adult↗
PubMedDate not supplied

A-mode ultrasonic detection of slow flow velocities in vitro.

The lower limits of detection of moving particles was studied with a sensitive A-mode scanner. Particles of two different sizes (25 microns and 90 microns) were perfused with different velocities in two different tubes. The motion of single latex particles with a diameter of 90 microns could be demonstrated in both tubes. The A-mode scanner had no lower limit in detecting motion of the 90 microns particles.

Blood Flow Velocity↗