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Biomedical subjects

A L Kairento

Publications and source records attributed to A L Kairento.

At least 19 recordsLinked to original sources
PubMed1989

Gastric emptying and serum insulin levels after intake of glucose-polymer solutions.

To examine the gastric emptying characteristics of four drinks varying in carbohydrate composition and concentration, five men ingested 600 ml of one of the different drinks on four separate occasions. All drinks contained Na+ 71 mmol.l-1, Cl- 60 mmol.l-1, Mg+2 5 mmol.l-1 and citrate 7 mmol.l-1; the carbohydrate component was either 3% glucose, 3% glucose-polymer (GP), 5% GP or 10% GP. With 99mTc-diethylene-triaminepenta-acetic acid (DTPA) as a marker, a scintillation camera and computer were used to measure the rate of gastric emptying. The half-emptying times (T 1/2) were inversely related to the glucose content of the solutions. The T 1/2 for 3% PG was 22.4 +/- 4.4 min (mean +/- SE) and for 10% GP 50 +/- 3.3 min (p less than 0.005). There was no significant difference in T 1/2 between the 3% glucose and 3% GP solutions. The increments in blood glucose (highest blood levels from 7.4 +/- 0.3 mmol.l-1 to 8.9 +/- 0.8 mmol.l-1), serum insulin (from 28 +/- 6 mU.l-1 to 77 +/- 13 mU.l-1) and C-peptide (from 3.6 +/- 0.4 micrograms.l-1 to 5.8 +/- 0.9 micrograms.l-1) were related to the amount of carbohydrate ingested. In all cases the serum insulin levels were high enough to inhibit the liberation of free fatty acids from the adipose tissue. It is concluded that the amount of carbohydrate in glucosyl units in the solution is a major determinant of gastric emptying.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Comparative evaluation of [123I]14-p-iodophenyl-beta-methyltetradecanoic acid and thallium-201 in the detection of infarcted areas in the dog heart using SPECT.

The concept of using beta-methyl-branched long-chain fatty acids for assessment of myocardial fatty acid uptake and perfusion was extended to the use of radioiodinated fatty acid with stabilization of iodine on the omega-phenyl ring. Beagle dogs were injected with thallium-201 and imaged 15 min after injection. The next day the dogs were infarcted by occluding the LAD, and 2 h later they were injected with [123I]14-p-iodophenyl-beta-methyltetradecanoic acid [123I]BMTDA and imaged for 90 min using a gated SPECT procedure. Maximum uptake of BMTDA in the heart was reached 2 min post injection and the activity level remained constant in the heart during the imaging period. The activity ratio of target to nontarget areas in the tomographic slices was significantly better for the BMTDA imaging compared to 201Tl (P greater than 0.01).

Animals↗
PubMed1988

No effect of growth hormone on recovery of load-protected bone. Cortical bone mass and strength studied in rabbits.

The effect of human growth hormone on the recovery of a previously atrophied diaphyseal bone, stress-shielded by plating, was studied in 56 adult rabbits using the contralateral tibia as a control. At removal of the plates, an initial 40 per cent reduction of torsional strength was seen. The strength was normalized in 3 weeks. A concomitant reduction of bone mineral density was normalized in 1.5 weeks. No difference in the rate of strength regeneration was found between growth hormone-treated rabbits and controls. In the treated rabbits an increase in cortical bone area due to subperiosteal new bone formation was seen in previously plated bones, as well as in sham-operated bones.

Animals↗
PubMed1986

Localization of melanoma with radiolabelled monoclonal antibody fragments and iodoamphetamine.

In two melanoma patients, metastases accumulated both 99mTc-labelled monoclonal anti-tumor F(ab')2 fragments and N-isopropyl-p-(123I)-iodoamphetamine. Small metastatic deposits were localized only by labelled antibody, for which a higher target-to-nontarget ratio was observed than for radioiodoamphetamine, indicating that immunoscintigraphy may be the more sensitive method. In these two patients positive immunohistochemical staining for the antibody used was observed, whereas in a third patient, with no concentration of labelled antibody, the staining result was negative showing the specificity of the immunoscintigraphy findings. It is possible that the accumulation of radio-iodoamphetamine is due to binding to melanin but this is not certain as tissue samples from one of the two patients with positive scintigrams did not contain stainable melanin.

Adult↗
PubMed1985

Positron emission tomography in oncology--the Massachusetts General Hospital experience.

Positron tomography has been used to measure blood flow, oxygen utilization, and glucose metabolism in soft-tissue tumors in rabbits and in human tumors in extremities. Both blood flow and oxygen utilization were increased in tumor in contrast to normal muscle tissue. Oxygen extraction fraction was, however, decreased in tumor. The most sensitive indicator of tumor growth was the glucose metabolic rate. The effect of irradiation was observed by blood flow measurements in human tumors and by blood flow and oxygen utilization in tumors in rabbits. Blood flow increased both in tumor and normal muscle tissue during irradiation and decreased afterwards. Oxygen utilization decreased in tumor and increased in normal tissue during irradiation.

Animals↗
PubMed1985

Comparative measurement of regional blood flow, oxygen and glucose utilisation in soft tissue tumour of rabbit with positron imaging.

The C15O2 and 15O2 steady state techniques have been used to quantitatively measure regional blood flow (RBF) and regional oxygen utilisation (ROU) in a rabbit tumour model. RBF values of 4.6 +/- 0.6 ml min/100 cc were measured for normal muscle tissue and 11.0 +/- 3.0 ml/min/100 cc for tumour surface. Corresponding values for ROU were 18.3 +/- 3.5 mumol/min/100 cc for normal tissue and 39.7 +/- 20.1 mumol/min/100 cc for tumour surface. 18F-2-fluoro-2-deoxy-D-glucose (2FDG) was used in the same tumour model to measure glucose metabolic rate. The values obtained were 4.3 +/- 2.1 mumol/min/100 cc for normal muscle tissue and 53.8 +/- 18.3 mumol/min/100 cc for tumour tissue. Tumour growth was followed with a series of measurements of blood flow, oxygen, and glucose metabolism at intervals of 1 week. Tumour-to-muscle ratios increased more rapidly with time for 2FDG than for oxygen utilisation and blood flow. The effect of radiation on tumour and normal tissue was followed by measurements of RBF and ROU. RBF values increased both in tumour and normal muscle tissue during radiation and decreased during one week after radiation. ROU-values decreased (30%) in tumour and increased (45%) in normal muscle tissue during radiation. Even at one week after radiation, ROU-values were 30% lower in tumour and 45% higher in normal muscle tissue than before radiation.

Animals↗
PubMed1984

Quantitative hippurate renography.

Effective renal plasma flow (ERPF) was determined by registration of 131I-hippurate radioactivity over the heart and calculation of the disappearance constants after fitting a three-exponential function to the measured time-activity curve. Right and left kidney ERPF was calculated both by a method of tangents and a new method of summed pulses from the time interval 1-2 min after injection of the tracer. The summed pulses method is less prone to errors and is therefore recommended for use in clinical practice. Age-dependent reference values for ERPF are reported.

Adolescent↗
PubMed1983

Long-term controlled trial with diphosphonate in patients with osteolytic bone metastases.

Thirty-four normocalcaemic women with multiple osteolytic bone metastases from breast cancer were randomly allocated to treatment with disodium dichloromethylene diphosphonate (Cl2MDP) 1600 mg/day orally (17) or placebo (17) for 3-9 months. Fasting urinary hydroxyproline/creatinine and calcium/creatinine ratios declined in the Cl2MDP group but not in the placebo group. Four patients in the placebo group died from hypercalcaemia. New bone metastases were more common in patients on placebo and these patients also required more analgesic drugs than those on Cl2MDP. Cl2MDP seemed to reduce bone pain and bone resorption and prevent the development of hypercalcaemia caused by osteolytic metastases. The formation of new bone metastases and the growth of old ones seemed to be retarded by Cl2MDP.

Adult↗
PubMed1983

Quantitation of regional cerebral glucose metabolism.

Kinetic analysis of 18F-labeled 2-fluoro-2-deoxy-D-glucose (2FDG) has been carried out in 28 studies on 25 subjects. The object of the analysis was to determine the practical problems of quantitation of glucose metabolic rate (GMR) using the Sokoloff model with 2FDG. We found that arterial and venous plasma concentration of 2FDG yielded equivalent values of the integrated plasma concentration (IPC*) and that one arterial or venous plasma sample at 30 min serves to predict IPC* to within +/- 7%. These observations suggest that quantitation is indeed possible in such subjects without using complex arterial or venous sampling procedures. The average values of K1, K2, and K3 are observed to be 0.14 +/- 0.08, 0.20 +/- 0.10, and 0.030 +/- 0.012 min-1. The data are consistent with a value of lumped constant of 0.4 and a considerable spread in global values of GMR (30%) in an unselected group of subjects.

Blood Glucose↗
PubMed1983

Regional blood-flow measurement in rabbit soft-tissue tumor with positron imaging using the C15O2 steady-state and labeled microspheres.

The C15O2 steady-state method, with tomographic measurement of H215O, has been used to measure blood flow in normal muscle tissue and a soft-tissue tumor (V2) in rabbits. the method has been validated in a rabbit tumor model by comparison of the data with that observed using microspheres labeled with Sc-46 and Ga-68. The blood-flow values found with the C15O2 steady-state method, after correction for tissue blood volume, agree well with values gained with labeled microspheres. The effect of blood volume on apparent blood flow in tumor was about 50%. The tissue/blood partition coefficients were 0.94 +/- 0.05 for healthy tissue and 1.16 +/- 0.15 for tumor tissue. After correction for partition coefficient and blood-volume effects, the blood-flow value for normal tissue was 4.1 +/- 1.3 ml/min-100 cc, and for the tumor tissue 10.7 +/- 2.3 ml/min-100 cc.

Animals↗
PubMed1982

Seasonal variation of urinary calcium and oxalate excretion, serum 25(OH)D3 and albumin level in relation to renal stone formation.

Seasonal variations in urinary calcium and oxalate excretion, serum 25(OH)D3 and albumin level were studied in 11 normo- and 11 hypercalciuric renal stone-formers, in 10 healthy subjects and in 14 long-stay hospital patients during one year. Serum albumin levels increased significantly during May--October in all four groups, whereas no significant changes occurred in serum calcium values when adjusted for differences in serum albumin concentration. Serum 25(OH)D3 level, urinary calcium and oxalate excretion were significantly higher during May--October than November--April in all except the long-stay hospital patients, whose corresponding values showed no seasonal changes and whose serum 25(OH)D3 levels as well as urinary calcium excretion were significantly lower than in the other three groups. The serum 25(OH)D3 level was significantly higher throughout the year in hypercalciuric than normocalciuric stone-formers. The hypercalciuric patients also passed more stones than the normocalciuric patients during a period of 9 years. There was a positive correlation between serum 25(OH)D3 and urinary calcium, between serum 25(OH)D3 and stone episodes and between urinary calcium and stone episodes. Because of this positive correlation, it might be useful to concentrate preventive therapy for recurrent renal stones to the light period only.

Adult↗
PubMed1981

Use of hormone receptors in scintigraphy of the ovaries.

Based on the mechanism of hormone receptors, luteinizing hormone (LH) labelled with 123-iodine was used as tracer in scintigraphy of rabbit ovaries. The ovaries were visualized in static pictures 6-15 min after injection except in the case where the rabbit was pre-injected with 10 micrograms of cold LH. 3.1% of the injected activity was found in the ovaries 14 h after injection.

Animals↗
PubMed1981

Hormonal pattern in prostatic cancer. I. Correlation with local extent of tumour, presence of metastases and grade of differentiation.

In 32 subjects with histologically and/or cytologically verified prostatic cancer the hormonal pattern was studied by assaying 18 plasma and urinary hormones or groups of hormones. The tumours were classified according to the UICC classification system and the hormone values were correlated to the local extent of the tumour (T classification), the presence of metastases (M classification) and the differentiation of grade (G classification). It was found that patients with metastases had significantly higher plasma oestradiol and lower testosterone/oestradiol and testosterone/oestrone plus oestradiol ratios as compared to those subjects without metastases. In subjects with moderately or poorly differentiated tumours plasma oestrone + oestradiol was significantly higher and the testosterone/oestrone + oestradiol ratio was significantly lower than in the subjects with well differentiated tumours. In the various TNM classification groups no obvious trends were found with regard to urinary hormones and no significant differences between the groups for plasma FSH, LH, prolactin, progesterone and cortisol were observed. It is concluded that in more advanced cases with metastatic cancer and when tumours are less well differentiated the androgen/oestrogen ratio may be decreased. These alterations have no diagnostic significance because of greater overlapping of individual results between the various groups of patients.

Age Factors↗
PubMed1981

Hormonal pattern in prostatic cancer. II. Correlation with primary response to endocrine treatment.

In 32 subjects with histologically and/or cytologically verified prostatic cancer the hormonal pattern was studied by assaying 18 plasma and urinary hormones or groups of hormones and relating the values to the response to endocrine treatment. Total orchidectomy (orchiepididymectomy) was performed on 9 patients, subcapsular orchidectomy on 13 patients and oestrogen therapy with Estradurin was given in 4 patients. Six patients had total orchidectomy followed by estrogen therapy. With few exceptions all values were within the normal range. The only significant exceptions were the high urinary oestrogen values and the low urinary oestrone + oestradiol/oestriol ratio observed as compared to healthy males working in a factory. No urinary hormone values or ratios of hormone values could be used for the prediction of prognosis in prostatic carcinoma patients. However, the ratios of plasma testosterone/oestradiol (T/Oe2) and testosterone/prolactin (T/Prl) were found to give good information with regard to the response to endocrine treatment. High values for one or both of these ratios meant a good response to treatment in all subjects without exception in this material. Subjects with both ratios low had a good response to endocrine treatment in 50% of the cases. No other plasma hormones measured were of any help prognostically. It is concluded that by measuring the T/Oe2 and T/Prl ratios it seems possible to select a group of patients with favourable primary response to endocrine treatment.

Aged↗
PubMed1980

Use of the modulation transfer function in comparing the visual outcome units of gamma camera.

Modulation transfer function (MTF) was used in comparing the visual outcome units of gamma camera. Polaroid camera system and Micro Dot imager were studied using Polaroid film type 105 positive/negative and Kodak SO-179 X-ray film. It was proved that resolution in the Micro Dot imager is better than in the Polaroid camera system used, especially near the surface of the measuring object.

Gamma Rays↗