Scintigraphy with 99mTc-labeled heat-altered erythrocytes in diagnosing hyposplenia: prospective comparison to 99mTc-labeled colloids and colour-coded duplex ultrasonography.

AIM: Ultrasound may be a cheap alternative to scintigraphic determination of splenic function. We directly compared nanocolloid scintigraphy (NS), scintigraphy with heat-altered erythrocytes (ES), and colour-coded Doppler sonography (DS) in patients with chronic inflammatory bowel disease (CIBD). PATIENTS, METHODS: 35 patients were included into the study. Clearance rates were determined in ES, spleen/liver ratios (SLR) were measured scintigraphically in ES/NS. In DS, spleen size, echogenicity, and vascular resistance indices (RI) were determined. The results were compared to each other, to the clinical activity scores for CIBD, and to the course of the disease. RESULTS: Based on the blood erythrocyte clearance serving as standard, patients had a good (19 patients), impaired (5), or missing splenic function (11). There was a good correlation of the clearance to SLR in ES (0.63, p < 0.01). The 10 min / 45 min ES clearance showed a high correlation (Spearman-Rho 0.87, p < 0.01). The SLR in ES at 2, 5, 10 and 45 min also correlated well with each other (Spearman-Rho > 0.9, p < 0.01; SLR > 3.45 normal splenic function, SLR < 1.22 indicated hyposplenia). There were no correlations between the results of NS, DS, Howell-Jolly-bodies, or clinical parameters. Only ES and the erythrocyte clearance correlated well. Howell-Jolly-Bodies detected 1 of 11 patients with hyposplenia while false-positive in 4. CONCLUSION: Ultrasound and colloid scintigraphy show a low correlation with clearance of heat-altered erythrocytes. Only ES shows a good correlation in patients with CIBD. The clearance at 10 min already reliably determines splenic function. SLR may be determined after 10 minutes and is predictive of normal function if above 3.45 while SLR < 1.2 indicated hyposplenia.

MtDNA mutations associated with sideroblastic anaemia cause a defect of mitochondrial cytochrome c oxidase.

We have recently described heteroplasmic mutations of mitochondrial DNA in patients suffering from sideroblastic anaemia. The mutations change conserved residues 1280 and M273 in subunit I of cytochrome oxidase, the terminal enzyme of the mitochondrial respiratory chain. As a step towards elucidating the pathogenic mechanism, we studied the biochemical consequences of the mutations by transferring mtDNA from these patients' platelets into a permanent human cell line lacking a mitochondrial genome. Mutation-induced changes of the enzyme and the energy metabolism of the cells were characterised in the transmitochondrial cell lines. One of the mutations resulted in a decreased cellular concentration of the enzyme and a corresponding decrease in activity. The second mutation changed the structure around the binuclear centre and forced the cells to rely more strongly on glycolysis.

Fast dynamic contrast-enhanced colour-coded MRI in uterine cervix carcinoma: useful for tumour staging?

OBJECTIVE: To quantify first-pass enhancement of cervix carcinoma using fast dynamic MRI. To assess the accuracy of dynamic contrast-enhanced colour-coded MRI for determining tumour invasion into surrounding pelvic tissues. METHODS: Gadolinium enhanced dynamic MRI at one image every 2 s was performed in 47 patients with cervical carcinoma and five controls. First-pass contrast enhancement of cervix carcinoma and surrounding pelvic tissues was quantified. Automated colour-coded images were constructed using the dynamic parameters slope, amplitude and timing of enhancement. Of 47 patients, 28 underwent surgery and colour coded images were correlated with histological findings. RESULTS: First-pass contrast enhancement imaging of cervix carcinoma required a temporal resolution of dynamic MRI of one image every 3-4 s. Cervix carcinoma first-pass was more rapid and intense than that of other pelvic tissues (P<0.001) with the exception of normal myometrium (P>0.05). Binary colour coding, however, was not reliable for tumour delineation or for accurate assessment of tumour invasion into the parametria or the bladder wall. Overestimation of the extent of tumour invasion occurred in 15, 16 and nine out of 28 patients, respectively, using amplitude, slope and timing of enhancement as parameters. CONCLUSION: Dynamic contrast-enhanced colour-coded MRI of cervix carcinoma has limited value for assessing the extent of tumour spread and tumour staging.