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Biomedical subjects

V Kempi

Publications and source records attributed to V Kempi.

At least 19 recordsLinked to original sources
PubMed1992

Constrained least-squares restoration and renogram deconvolution: a comparison by simulation.

Before deconvolution can be used in renography, it is necessary to decide whether the renal function is sufficiently good to allow it. To see if this decision can be circumvented, an iterative constrained least-squares restoration (CLSR) method was implemented in which the point of termination of the iteration occurs when a residual vector has a value less than an estimate of the noise in the original renogram curve. The technique was compared with the matrix algorithm and with direct FFT division. The comparison was achieved by deconvolving simulated renogram data with differing transit time spectra and statistics. As expected, the FFT technique produced results of little value whereas the CLSR and matrix methods produced values of mean transit time (MTT) that differed slightly from the expected results. Analysis indicated that the matrix approach was superior when the percentage noise component was less than 6% and vice versa. No technique produced useful transit time spectra. As the CLSR technique produced better results than the matrix method in simulations with relatively long MTTs and high noise, it seems reasonable to suggest that it might be used for renogram deconvolution without the need for previous inspection of the curves.

Humans↗
PubMed1992

Renal function not impaired by hip arthroplasty. A prospective study of 26 patients.

To evaluate the importance of various changes during major surgery, 26 patients, electively chosen for total hip replacement (THR), were investigated for renal function preoperatively and postoperatively. In most of the patients, surgery was performed ad modum Charnley (n 25), and anesthesia was given mainly by continuous administration of bupivacaine or mepivacaine through an epidural catheter. Postoperatively, there was an improvement in glomerular filtration rate (GFR) and a reduction in renal concentrating ability (RCA), but no change in diurnal albumin excretion. No correlation was found between the change in GFR and, e.g., the degree of peroperative hypotension, bleeding, transfusions, or volume of infusions. There was a correlation between the impairment of RCA and the lowering of serum albumin concentration. In 3 patients the GFR was slightly impaired. The risk of contracting severe, acute renal failure seems low in THR performed on patients with reduced or normal kidney function.

Acute Kidney Injury↗
PubMed1990

Long-term effect of dopaminergic drugs in restless legs. A 2-year follow-up.

Thirty patients with restless legs syndrome, who initially had all responded well to treatment with levodopa and benserazide, were studied as to the long-term effect of the drugs (at least 2 years). During the 2-year period, two patients were switched from levodopa to bromocriptine. Two patients no longer needed levodopa; one of them had developed paraplegia and in the other the symptoms of restless legs syndrome had disappeared completely. The remaining 26 patients continued to use levodopa. Eight patients maintained the original dose, nine had to use an increased dose, and nine found a decreased dose to be sufficient. The only side effect was transient nausea reported by two of the 30 patients. The study showed that the relief of symptoms of restless legs syndrome by dopaminergic drugs does not wear off with the passage of time, that side effects are minimal even with long-term use, and that the dose needed to obtain relief may increase as well as decrease.

Adolescent↗
PubMed1990

A study of so-called hypochondriasis.

Twenty-four patients with unexplained somatic complaints were subjected to a thorough somatic examination. Only when the examination proved negative was the patient entered into the study. The patients were clinically appraised according to criteria given in DSM-III. Generalized anxiety disorder (GAD) was diagnosed in 12, somatization disorder (SD) in 8, and hypochondriasis in 4 patients. Seventeen of the 24 patients agreed to participate in biochemical investigations including a TRH load, a dexamethasone test, and a determination of the monoamine metabolites 5-HIAA and HVA in cerebrospinal fluid (CSF). A normal TSH increase and a normal suppression of cortisol were registered. The HVA values correlated significantly with the 5-HIAA values as well as with the alexithymia scores. Concerning alexithymia and maturity level, no difference as to social class was found. The patients filled in a Zung depression chart. The Zung scale and the 5-HIAA values were both inconsistent with depressive illness. In so-called hypochondriasis a long-term relationship, including selected somatic and biochemical examinations and thorough information, was crucial in abating the patient's distrust and thus the need for health care.

Adult↗
PubMed1990

Cholescintigraphy versus infusion cholecystography in acute cholecystitis.

Patients with the clinical diagnosis of acute cholecystitis were studied with intravenous cholecystography and cholescintigraphy. The two examinations alternated in a random order. The final diagnosis was ascertained by surgery in most patients. Either cholecystography or cholescintigraphy could be used in the diagnostics of patients with suspected acute cholecystitis. The methods have about the same accuracy. However, cholescintigraphy is performed more easily and more rapidly than intravenous cholecystography.

Acute Disease↗
PubMed1988

Deconvolution analysis of renograms obtained with simultaneously administered 99mTc-DTPA and 131I-hippuran.

Seventy patients were studied with a dual radionuclide technique. The conventional renograms and the blood curve were subjected to deconvolution analysis using the matrix algorithm method, and the following curve data calculated from the retention functions: absolute and relative amplitudes, minimum time of the retention function, maximum time of the retention function and mean transit time. The findings with the two radiopharmaceuticals 99mTc-DTPA and 131I-Hippuran were compared under normal and pathological conditions. The correlations between the data with 99mTc-DTPA and those with 131I-Hippuran were highly significant (p less than 0.01). So was the correlation between the absolute amplitude of the retention curve and the rate of uptake based on the corresponding renogram (p less than 0.01). Due to the difference in the renal handling of the two tracers, longer maximum times were obtained with 99mTc-DTPA. The mean transit times were also longer with 99mTc-DTPA, except in kidneys with parenchymal insufficiency. The highest amplitudes were found in normal kidneys, while the lowest values were observed in parenchymal insufficiency. In the group with acute ureteral obstruction, the mean transit times tended to be increased. The maximum times were even more increased. With both tracers it is possible to distinguish between the three groups of renal conditions studied here: Normal, parenchymal insufficiency, and acute ureteral obstruction.

Acute Disease↗
PubMed1987

A FORTRAN program for deconvolution analysis using the matrix algorithm method with special reference to renography.

A FORTRAN IV program is presented for deconvolution analysis using the matrix algorithm method. With the deconvolution technique retention functions are calculated from time-activity curve data representing both kidneys and blood background. The program computes for each kidney the minimum and maximum time of the retention function. It also calculates the initial amplitudes, absolute as well as relative, and the mean transit time of the retention functions. The design of the program allows for optional reviews of intermediate outputs at important stages. It also allows for the plotting of conventional time-activity curves of both kidneys corrected for blood background. Finally, the program plots the retention functions and some of their characteristics.

Algorithms↗
PubMed1985

A FORTRAN program for ranking and for calculation of Spearman's correlation coefficient.

A FORTRAN IV program is presented for ranking data in ascending order. The ranks corrected for ties are printed together with the corresponding raw data, if requested. After ranking, the Spearman's rank correlation coefficient, rs, as well as the corresponding t-value, can be calculated. In these calculations corrections are made for tied values.

Biometry↗
PubMed1985

Bile flow before and after cholecystectomy: a study with 99mTc-HIDA.

Computer-assisted 99mTc-HIDA cholescintigraphy was performed before and after elective cholecystectomy in 24 patients. Preoperative cholecystography had shown gallstones in a well visualized gallbladder in 12 of the patients, and in 12 the gallbladder had not been visualized. Liver function tests gave normal results in all 24 patients, and peroperative cholangiography showed no common duct stones in any patient. In the series with functioning gallbladder, comparison of the preoperative and postoperative scintigrams showed that cholecystectomy was followed by significantly earlier visualization of the lower part of the common duct and of the duodenum. The number of times that passage of activity to the duodenum was observed also rose significantly. Comparison of the time-activity curves showed that after cholecystectomy the liver activity reached its maximum value significantly earlier post-injection as compared with the preoperative values. All of these changes were absent in the series with nonfunctioning gallbladder. Removal of a functioning gallbladder results in accelerated, though still irregular flow of activity to the duodenum.

Adult↗
PubMed1985

In vitro interaction between venous blood clots and radiopharmaceuticals.

Clots of 1 ml venous blood formed in glass tubes after 10 min at room temperature were incubated at 37 degrees C with the radiopharmaceutical to be studied. Methods for quality control of the radiopharmaceuticals were compared. Gel chromatography scanning was found to give reliable information. The incorporation into the clot was studied at different pH values and after various time intervals. The highest incorporation was found for 125I-fibrinogen and for 99mTc-macroaggregates of albumin, followed by 99mTc-sulphur colloid and 99mTc-streptokinase at pH less than 2. The titrated initial dose of 99mTc-streptokinase was studied at various pH levels. The lysing effect was less in the pH range 1-2.5, where the best labeling yield was obtained. The inactivation of streptokinase by the labeling procedure was also studied with immunoelectrophoresis and decomposition of casein. In vitro studies of the interaction of radiopharmaceuticals with clots add information for the clinical use of radiopharmaceuticals for thrombus localization.

Fibrinogen↗
PubMed1984

Filling of the gallbladder as studied by computer-assisted Tc-99m HIDA scintigraphy: concise communication.

Gallbladder filling was studied using computer-assisted cholescintigraphy in normal subjects who had fasted overnight. The gallbladder tended to visualize earlier than the distal part of the common bile duct. It appeared at approximately the same time regardless of whether or not there was passage of activity into the duodenum. This suggests that filling is not dependent on contraction of the sphincter of Oddi. Sequential images demonstrated that the activity entering the gallbladder rapidly reached the fundus. Time-activity curves showed a gradual buildup of activity in the bile ducts followed by sudden entrance into the gallbladder. Time-activity curves of the gallbladder's proximal and distal parts showed signs of an exchange of activity, suggesting that the gallbladder's motor function is not quiescent during fasting. Gallbladder motility could explain the periodic irregularities on the time-activity curve. These irregularities were smaller but not less frequent after morphine administration.

Adult↗
PubMed1983

Evaluation of renal function parameters with simultaneously administered 99mTc-DTPA and 131I-hippuran.

The present study aimed at comparing two renal function tests using 99mTc-DTPA (diethylene triamine penta acetic acid) and 131I-labeled hippuran (o-hippuric acid). A mixture of 80 MBq 99mTc-DTPA and 7.4 MBq 131I-hippuran in a total volume of 1.5 ml or less was injected into an arm-vein. Both radiopharmaceuticals have identical initial distributions in the blood pool when injected in this manner. Seventy-two patients were studied with the present dual radionuclide technique. The following parameters were derived from the renogram: area under curve, uptake ratio, Tmax, decrease ratio, excretion ratio, and rate of decrease. The parameters for 99mTc-DTPA and 131I-hippuran were compared for various kidney groups. Generally the renographic parameters were well correlated. Apart from the systematic differences due to different modes of renal excretion, the curve patterns virtually agreed. The differences that were observed between the two tracers lacked clinical significance.

Humans↗
PubMed1983

Jaundice in acute cholecystitis without common duct stones.

Patients with acute cholecystitis without common duct stones were studied pre- and postoperatively with 99mTc-HIDA scintigraphy. The resulting hepatic time-activity curves were analyzed. Preoperative serum bilirubin levels were closely correlated with hepatic discharge but not with hepatic uptake of the radiopharmaceutical. Cholecystectomy resulted in prompt improvement of hepatic discharge but did not affect uptake. In acute as well as in chronic cholecystitis cholangiograms taken before removal of the gallbladder were compared with those taken after. In acute cholecystitis the former view frequently showed medial displacement of the biliary tract and incomplete filling of its proximal part. Displacement of the duct was also apparent in comparisons of pre- and postoperative scintigrams. Jaundice in acute cholecystitis is due to reduced excretion which may be caused by pressure on the ducts by the distended gallbladder.

Acute Disease↗
PubMed1981

A radionuclide study on the effectiveness of drainage after elective cholecystectomy.

Passive drainage after elective cholecystectomy was studied in six patients. Their erythrocytes were labeled in vitro with technetium-99mTc and injected via the drain after operation. After one hour, we were able to recover labeled erythrocytes and free pertechnetate from peripheral blood. After 24 hours, a large part of the injected erythrocytes had been evacuated via the drain. In eight patients subjected to cholecystectomy, 99mTc-HIDA was injected intravenously after the operation. In four cases, in which the gallbladder bed was raw, the activity ratio discharge/blood rapidly reached extremely high values. In the other four cases, in which the liver surface had not been denuded, the ratio was much lower. Passive drainage is a useful device for evacuation intra-abdominal bile or hemolysed blood after cholecystectomy, especially when the gallbladder bed has been denuded.

Abdomen↗
PubMed1978

Measurement of vesicoureteral reflux with intravenous 99mTc-DTPA compared to radiographic cystography.

The results of a 99mTc-DTPA study of vesicoureteral reflux in 51 children with recurrent urinary tract infections were compared with those of radiographic micturition cystourethrography. Reflux, shown by either of the two methods, was regarded as an indication of the disorder. Neither method was regarded as a standard reference method. Agreement between the two methods was obtained in 90 of 102 renal units, i.e., ureter and/or renal pelvis (88%). Statistical analysis performed on the remaining 12 cases showed that the two procedures usually gave similar results.

Adolescent↗
PubMed1976

Nephrotic syndrome due to subacute glomerulonephritis -- association with hydrocarbon exposure?

A 59-year-old man developed a nephrotic syndrome 40 days after hydrocarbon exposure of 3 days' duration. Renal biopsy gave evidence of a subacute proliferative glomerulonephritis. A lasting remission was obtained with immunosuppressive therapy. The case history is discussed in the light of recent studies indicating a causal relationship between hydrocarbon exposure and glomerulonephritis. The reversible nature of the disease in the present case is discussed in relation to the disease in experimental animals induced by a single administration of heterologus antigen.

Environmental Exposure↗
PubMed1976

Effect of flow material ski boots on foot circulation.

The effect of modern "flow material" ski boots on foot circulation was studied. Pressure inside a flow material ski boot was found to be markedly higher than in a conventional ski boot. In some places the pressure exceeded the diastolic pressure in the foot. 113mIndium chloride, which when injected intravenously is bound to transferrin was used for blood pool scanning. In healthy young volunteers the uptake of radioactivity in the two feet--one with and one without a ski boot--was compared. The activity level of the foot with the ski boot was significantly lower than in the other foot. After corrections were made for absorption by the boot, a significant difference remained. Plethysmographic studies were performed with a mercury strain gauge using a ski boot in which a hole was cut over the big toe. No difference was demonstrated between the blood pressure at the leg just above the boot top and at the big toe. The arterial pulse wave at the big toe was altered; i.e., there was an absence of a dichrotic wave. Intramuscular perfusion was studied with 133xenon. The disappearance curve in a foot with a boot was more shallow than that in a bare foot. Unbuckling resulted in an immediate fall in radioactivity, the disappearance curve then becoming identical to that of the bare foot. The results indicate that when flow material ski boots are to be used by skiers who are not in the habit of unbuckling for short intervals, buckle tension should not be too high.

Blood Circulation↗