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Biomedical subjects

K Liewendahl

Publications and source records attributed to K Liewendahl.

At least 19 recordsLinked to original sources
PubMed1992

Interictal brain 99Tc-HM-PAO SPECT hypoperfusion in patients with unstable partial epilepsy and normal CT.

Brain perfusion was studied interictally with 99mTc-HM-PAO SPECT in 47 adult patients with partial epilepsy and normal brain CT. Epilepsy was classified as secondarily generalized in 24 patients, as complex partial in 17 patients and as simple partial in 6 patients. In 24 patients good seizure control was not achieved as these patients had a median number of 78 seizures during the preceding month, while in the rest of the patients seizure control was relatively good (less than 6 seizures during preceding month). Local brain hypoperfusion was observed in 41 or 87% of the patients. Hypoperfusion was located close to the EEG foci in 76% and equally often with temporal and frontal foci. Hypoperfusion and the EEG focus were located on the same side in 83%. Hypoperfusion was more frequent in secondarily generalized epilepsy and simple partial epilepsy than in complex partial epilepsy. Left-sided hypoperfusion was especially associated with complex partial epilepsy. It is likely that the significant epileptogenic brain area was revealed in patients with SPECT focus and EEG focus in the same brain area. In one of our patients MRI showed a small temporal lesion which on successful removal was identified as a low-grade oligodendroglioma. Abnormalities of regional brain uptake of HM-PAO demonstrated by SPECT in patients with partial epilepsy and normal brain CT give further information about pathophysiology in partial epilepsy; this may be of use both for selecting appropriate therapy and in presurgical localization of foci.

Adult↗
PubMed1992

Fatty acid-induced increase in serum dialyzable free thyroxine after physical exercise: implication for nonthyroidal illness.

In 14 healthy males, prolonged running exercise resulted in a mean 25% increase in serum free T4 (FT4) concentration (P less than 0.001) which was significantly correlated (P less than 0.01-0.02) with an over 5-fold increase in the concentration of serum FFA and the FFA/albumin molar ratio. Hemoconcentration, as reflected in a mean 19% increase in serum albumin, caused an increase in serum T4-binding globulin and therefore also in serum total T4. As there was no change in the serum T4/T4-binding globulin molar ratio, the rise in serum FT4 was probably not caused, or only partly caused, by an exercise-induced shift of T4 from the extravascular to the intravascular compartment. Neither is it likely that the mean 41% increase in serum TSH observed after exercise, partly owing to hemoconcentration, was the reason for the increase in serum FT4 and T4 as there was no correlation between the increases in the TSH and thyroid hormone levels. Further support for the assumption that the elevation in serum FT4 after exercise was FFA-induced was provided by the observation that addition of 2.5 mmol/L oleic acid to normal serum in vitro resulted in a 33% increase in serum FT4 (P less than 0.001). There is an association between increased concentrations of serum FT4 and unsaturated FFA in patients with various nonthyroidal illnesses according to earlier observations, but it is unlikely, in the light of the present data from healthy subjects, that FFA are directly involved in raising the serum FT4 concentration in nonthyroidal illnesses patients unless the serum FFA concentration exceeds 2 mmol/L or the FFA/albumin molar ratio rises above 2.5.

Adult↗
PubMed1992

Platelet splenic transit times in idiopathic thrombocytopenic purpura. Compartmental vs. non-compartmental model.

Platelet splenic transit times following injection of autologous or homologous 111In-labeled platelets were studied in 42 patients with idiopathic thrombocytopenic purpura. The transit times were determined by two methods from the splenic time-activity curves recorded with a gamma camera: closed two-compartmental model and non-compartmental model (deconvolution analysis). By compartmental analysis the mean splenic transit time for platelets was 6.3 +/- 0.3 min (mean +/- S.E.) and by non-compartmental analysis 7.6 +/- 0.4 min for all cases studied. The mean splenic transit time for autologous platelets was significantly (p less than 0.001) shorter (5.1 +/- 0.3 min) in patients with platelet-associated IgG (measured by platelet suspension immunofluorescence test) than in those with no autoantibodies (7.1 +/- 0.4 min), when the compartmental model was employed. There was no significant difference between mean transit times for autologous platelets in antibody positive and negative patients when deconvolution analysis was applied, but the residue of the splenic transfer function was lower for antibody positive than negative patients (7.2 +/- 1.0% vs. 11.7 +/- 1.6%, p less than 0.05). It is concluded that in idiopathic thrombocytopenic purpura the presence of platelet-associated autoantibodies expands the splenic platelet pool and reduces recirculation of platelets.

Adolescent↗
PubMed1991

99Tcm-HMPAO SPECT in suspected dementia.

To evaluate the usefulness of 99Tcm-hexamethylpropyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) in suspected dementia we studied 160 consecutively imaged elderly patients from our hospital's memory disorder clinic. The diagnosis was based on clinical data, laboratory tests, neuropsychological examination, computed tomography (CT) and EEG. The patients were divided into six diagnostic categories: Alzheimer's disease (AD), multi-infarct dementia (MID), frontal lobe-type dementia (FTD), vascular encephalopathy not fulfilling the criteria of dementia, specific organic conditions, and psychiatric disorders. SPECT images were assessed without knowing the clinical diagnosis, and divided into AD pattern, FTD pattern, MID pattern, abnormal but unclassifiable, and normal. Twenty-three of 36 patients with clinical AD, 25/33 patients with clinical MID, and 2/5 patients with clinical TFD had compatible SPECT patterns. SPECT distinguished AD from MID in the majority (80%) of cases. In patients with depression or anxiety SPECT was abnormal in 16/21 cases, suggesting that SPECT may give early clues to the presence of an underlying organic disease in such elderly patients. Thus, SPECT with 99Tcm-HMPAO seems to be useful in the diagnosis of suspected dementia.

Aged↗
PubMed1991

Hormonal changes in severely uncontrolled type 1 (insulin-dependent) diabetes mellitus.

To investigate endocrinological changes associated with severely uncontrolled type 1 (insulin-dependent) diabetes mellitus 27 patients (19 men, eight women) with ketoacidosis or severe ketonuria (= group 1) were examined on admission and after recovery. For comparison 13 non-ketotic patients (seven men, six women), admitted for adjustment of treatment because of poor diabetic control (= group 2), and 20 healthy controls were studied. On admission, the serum testosterone levels in men were lower in group 1 (15.1 +/- 2.0 nmol l-1) (mean +/- SEM) than in group 2 (27.2 +/- 2.8 nmol l-1) (p less than 0.01) and healthy controls (20.6 +/- 2.0 nmol l-1) (p less than 0.05). During treatment the testosterone levels in group 1 rapidly rose to the control level. The serum oestradiol levels in women were low in group 1 both on admission and discharge. The serum prolactin levels were low in female patients in group 1 (119 +/- 17 mIU l-1) compared with the women in group 2 (315 +/- 75 mIU l-1) (p less than 0.05). On admission the serum cortisol levels were higher and their response to 1 mg of dexamethasone was weaker in group 1 than in group 2 and healthy controls. After recovery the serum cortisol levels fell by 15% (p less than 0.01) and the response to 1 mg of dexamethasone returned to normal in group 1. In group 1 during treatment the serum free T4 and reverse T3 levels fell, and the T3 levels rose, whereas the thyroid stimulating hormone (TSH) levels and their responses to TRH remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Immunolymphoscintigraphy and immunoscintigraphy of ovarian and fallopian tube cancer using F(ab')2 fragments of monoclonal antibody OC 125.

We have used immunolymphoscintigraphy (ILS) alone or in combination with immunoscintigraphy with 131I-labeled F(ab')2 fragments of monoclonal OC 125 antibodies to improve detection of retroperitoneal lymph node metastases of ovarian and fallopian tube cancer. ILS was carried out with bilateral dorsopedal s.c. injections on nine patients and with bilateral iliopelvic injections into the ischiorectal fossa on two other patients. Radioimaging was performed 2-4 times between 0 and 5 days. An additional dose of labeled antibody fragments was given i.v., and imaging was done 2-3 days later. Conventional immunoscintigraphy without preceding ILS was carried out on another nine patients. Dorsopedal ILS improved detection of pelvic and paraaortic lymph node metastases. Malignant lymph nodes were detectable as early as 3 h after s.c. injection of the tracer. Combined results of ILS and immunoscintigraphy in 16 surgically verified cases indicated a true positive finding in 9 patients, true negative finding in 5, false positive in one, and false negative in 1. Calculated from these figures the sensitivity, specificity, and accuracy of the method were 90, 83, and 88%, respectively. Involved lymph nodes were found more frequently in those patients whose serum CA 125 concentration was elevated demonstrating that an elevated serum CA 125 level does not preclude successful radioimmunodetection.

Adult↗
PubMed1990

Anti-melanoma antibodies bind preferentially to diploid metastases in immunoscintigraphy.

Immunoscintigraphy with 99Tcm-labelled anti-melanoma monoclonal antibody F(ab')2- fragments was performed in 23 patients with histologically verified metastatic melanoma. Immunoscintigraphy was positive in 14 patients and all known metastases were detected in eight patients, five of whom had only one lesion. Lesion localization and detectability were as follows: 12/13 (92%) cutaneous and subcutaneous, 11/14 (79%) lymph node, 5/7 (71%) bone, 3/6 (50%) lung and 1/5 (20%) abdominal metastases were visualized. Despite its high specificity--no false positive immunoscintigrams--the low sensitivity of this method in detecting deep metastases hampers its usability. The false negative results were not due to lack of antigen expression as positive immunostaining results were observed also in specimens from patients with negative immunoscintigrams. Flow cytometric analysis of the metastases revealed that in 7/8 (88%) patients with diploid tumours had positive immunoscintigrams but only 7/15 (47%) patients with aneuploid tumours. These results show that the diagnostic accuracy of melanoma immunoscintigraphy can be improved by selecting patients not only by testing for the antigen but also on the basis of DNA analysis of an accessible lesion.

Abdominal Neoplasms↗
PubMed1990

Prostate tumour markers as an aid in the staging of prostatic cancer.

Serum acid phosphatase activity (ACP), prostate specific phosphatase (PAP) and prostate specific antigen (PSA) were measured in 100 patients with prostatic cancer. The patients were divided into 4 groups: T1-2 MO, T3-4 MO and M1 patients with less than or equal to 10 or greater than 10 metastatic foci in bone scintigraphy. The mean serum ACP levels were almost identical in the T1-2 MO and T3-4 MO groups and there was no significant difference between the mean PAP values. Significantly higher PSA levels were observed in the MO patients in the extracapsular category compared with those in the intracapsular category. The mean serum levels of all 3 tumour markers were significantly higher in the M1 than in the MO category. PSA seems to be the marker of choice as a diagnostic aid for differentiating between patients with intracapsular and those with extracapsular tumour growth. In prostatic cancer patients with bone metastases these markers were of similar value for staging the disease.

Acid Phosphatase↗
PubMed1990

The development of nuclear medicine imaging.

Great progress has been made in nuclear medicine imaging during the forty years this imaging modality has existed. Advances have been made both in the area of instrumentation and radiopharmaceuticals. The development started with a single detector system but now imaging devices can produce tomograms displayed three-dimensionally on graphic monitors. The general trend in the production of radiopharmaceuticals has been the development of highly specific compounds for mapping of biological structures and functions.

Gamma Cameras↗
PubMed1990

Compartmental analysis of short-lived platelet dynamics.

111In-labelled platelets were used for analysing platelet dynamics in 43 patients with idiopathic thrombocytopenic purpura (ITP). The detected time-activity curves, recorded with a gamma camera, were analysed by three methods: two- and three-compartment models, and an open model in which only the splenic curve was analysed. In the two-compartment model the mean rate constant from blood to spleen was 0.328 +/- 0.028 min-1 (mean +/- SEM) and from spleen to blood 0.061 +/- 0.007 min-1, whereas in the three-compartment model the corresponding values were 0.236 +/- 0.020 and 0.044 +/- 0.007 min-1, respectively. The mean rate constant from blood to liver was 0.466 +/- 0.149 min-1 and from liver to blood 0.341 +/- 0.106 min-1 as derived from the three-compartment model. The rate constant from spleen to blood, as determined from the three-compartment model, was significantly higher in patients with a strongly positive result for platelet-associated auto-antibodies (platelet suspension immunofluorescence test (PSIFT] than in patients with a negative PSIFT. The mean hepatic net rate in patients with a high level of antibodies is into the liver, while in patients with little or no antibodies the net rate is into the blood pool. The mean half-life for the fast component of the inverted splenic curve was 2.5 +/- 0.2 min and for the slow component 16 +/- 2 min. In patients with a strongly positive PSIFT the half-life for the slow component was significantly longer than in patients with a negative PSIFT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Assessment of thyroid status by laboratory methods: developments and perspectives.

Serum protein-bound iodine and in vivo radioiodine tests were employed for over three decades although their usefulness was hampered by interference from iodinated compounds. Tests reflecting thyroid hormone action were therefore used for additional information on thyroid status. Competitive saturation analysis of serum T4 was introduced in the 60s. RIAs for T4 and T3 were not developed until ten years later because of problems in raising polyclonal antibodies to small haptens. Methods for FT4 and FT3 based on equilibrium dialysis of serum labelled with radioiodinated hormone emerged in the 60s, and in the 70s sensitive RIAs enabled direct determination of free hormone concentrations in serum dialysate. Dialysis and ultrafiltration methods are tedious and therefore various free hormone indices, based on total hormone concentrations and tests for unoccupied thyroid hormone-binding sites, have been used right up to our times. In the 80s rapid assays for FT4 and FT3 based on varying principles were developed particularly by commercial companies. Free hormone assays utilizing thyroid hormone analogs as tracers have been criticized because binding of analogs to serum proteins results in spurious values in conditions characterized by thyroid hormone-binding protein abnormalities. Bioassay of TSH was not adopted by the clinical service laboratory because of insufficient analytical sensitivity. The first immunological TSH assay, based on cross-reaction of human and bovine TSH in a hemagglutination inhibition test, was also too insensitive for practical purposes. RIAs for direct determination of normal TSH concentrations were developed in the 60s. The breakthrough in measurement of low TSH concentrations occurred in the 80s with the advent of immunometric assays utilizing monoclonal antibodies. Recently chemiluminescence, fluorescence and enzyme labels have been used for the development of non-isotopic methods for thyroid hormones and TSH. Immunoassay systems for bed-side measurement of analyte concentrations are being developed and immunosensors for continuous monitoring of analyte levels will probably be available in the future.

Dialysis↗
PubMed1990

Imaging of soft-tissue sarcomas with indium-111-labeled monoclonal antimyosin Fab fragments.

Some soft-tissue sarcomas contain intracellular myosin. We therefore studied the possibility of localizing various soft-tissue sarcomas with 111In-labeled monoclonal antibody Fab fragments binding specifically to myosin, assuming that damage to the cell membrane could expose intracellular myosin. Nineteen patients with different types of soft-tissue sarcomas were studied. Eighteen patients were found to have abnormal antibody uptakes. Antibody uptake was not observed in an additional patient operated for a benign tumor (gastric leiomyoma). The immunoscintigraphy results were generally in good agreement with those of other radiologic findings (computed tomography, ultrasound, magnetic resonance imaging). Surprisingly, the immunohistochemistry results showed that tumors not stainable for myosin can also be imaged with antimyosin. Thus, the mechanism of antibody uptake does not seem to be related entirely to specific antigen recognition. Irrespective of the exact mechanism for the uptake of labeled antibody this method appears to be useful for localizing soft-tissue sarcomas.

Adult↗
PubMed1989

The evaluation of a chemiluminescent assay for free thyroxine by comparison with equilibrium dialysis in clinical samples.

We have investigated the diagnostic performance of a chemiluminescence immunoassay for free thyroxine (Ciba Corning Magic Lite) in comparison with equilibrium dialysis. Agreement between the methods was satisfactory across a wide range of samples including those from patients with non-thyroidal illness. The results suggest that the chemiluminescence immunoassay is not subject to the artefacts of widely used analogue tracer methods for free thyroxine estimation.

Adolescent↗
PubMed1989

Brain perfusion defect size in SPECT predicts outcome in cerebral infarction.

The results of previous reports on the usefulness of brain perfusion single photon emission computed tomography (SPECT) in predicting the outcome of patients with acute cerebral infarction are conflicting. We therefore studied brain perfusion in 64 patients with a single supratentorial infarction. Contradictory to previous results the perfusion defect volume estimated from transversal and coronal slices correlated significantly with both presenting clinical findings and outcome. Although the clinical status at admission also correlated well with outcome, there was a subgroup of patients in which the favourable outcome was predicted only by SPECT and not by physical or any other examination at admission.

Adult↗