Synergistic action of tiazofurin with hypoxanthine and allopurinol in human neuroectodermal tumor cell lines.

The activity of IMP dehydrogenase (EC 1.2.1.14), the key enzyme of de novo guanylate biosynthesis, was shown to be increased in tumor cells. Tiazofurin (TR), a potent and specific inhibitor of this enzyme, proved to be effective in the treatment of refractory granulocytic leukemia in blast crisis. We examined the effects of tiazofurin as a single agent and in combination with hypoxanthine and allopurinol in six different neuroectodermal tumor cell lines, the STA-BT-3 and 146-18 human glioblastoma cell lines, the SK-N-SH, LA-N-1 and LA-N-5 human neuroblastoma cell lines, and the STA-ET-1 Ewing tumor cell line. Tiazofurin inhibited tumor cell growth with IC50 values between 2.2 microM (LA-N-1 cell line) and 550 microM (LA-N-5 cells) and caused a significant decrease of intracellular GTP pools (GTP concentrations decreased to 39-79% of control). Incorporation of [8-14C]guanine into GTP pools was determined as a measure of guanylate salvage activity; incubation with 100 microM hypoxanthine caused a 62-96% inhibition of the salvage pathway. Incubation with tiazofurin (100 microM) and hypoxanthine (100 microM) synergistically inhibited tumor cell growth, and the addition of allopurinol (100 microM) strengthened these effects. Therefore, this drug combination, inhibiting guanylate de novo and salvage pathways, may prove useful in the treatment of human neuroectodermal tumors.

The effect of cordocentesis on umbilical and middle cerebral artery blood flow velocity waveforms.

OBJECTIVE: To investigate the effect of cordocentesis on the umbilical and fetal cerebral circulation. DESIGN: Cross sectional study. SETTING: Department of Obstetrics and Gynaecology, Regional Referral Centre for Fetal Medicine, Klagenfurt Hospital, Austria. SUBJECTS: Thirty pregnant women undergoing diagnostic cordocentesis at 18 to 38 weeks' gestation. INTERVENTIONS: The pulsatility index (PI) in the umbilical artery and fetal middle cerebral artery was measured by pulsed Doppler ultrasound before and immediately after cordocentesis. MAIN OUTCOME MEASURES: Change in umbilical artery PI and middle cerebral artery PI. RESULTS: Cordocentesis was associated with a significant decrease in both umbilical artery PI (median -0.18, range -2.21 to 1.5, P < 0.004) and middle cerebral artery PI (mean -0.15, SD 0.32, P < 0.03) and the decrease in umbilical artery PI was most marked when cordocentesis was performed transplacentally. In four cases, there were absent or reversed frequencies at the end of diastole (EDF) in the umbilical artery before cordocentesis, and in all cases there were positive EDF after the procedure. In contrast, one of the 26 cases with positive EDF developed reversed EDF following the procedure. CONCLUSIONS: Acute alterations in the waveforms from both the umbilical and fetal cerebral circulation can be induced by cordocentesis. The decrease in resistance in the fetoplacental circulation could be attributed to the release of vasodilators, and the increase in resistance observed in some cases could be secondary to arterial vasospasm. Better understanding of the underlying mechanisms might help in making cordocentesis a safer procedure.

[Doppler flow measurements of the uterine artery. A prognostic factor for success in treatment by IVF?]. / Doppler-Flow-Messungen in der Arteria uterina. Ein Prognosefaktor für den Erfolg bei der Behandlung durch IVF?

117 patients treated for infertility with IVF-ET were included in a prospective study to evaluate the prognostic value of Doppler-flow measurements in the uterine artery on the day of oocyte retrieval. The PI was calculated after transabdominal pulsed Duplex-Doppler-flow measurement in the uterine artery, which was localised in the B-scan or using a colour Doppler. The success of the IVF procedure could be predicted statistically significant for both--pregnant or not--(p = 0.0316) and--ongoing pregnancy or first trimester abortion--(p = 0.0079) by better uterine flow. At the same time the diameter of the endometrium was measured. There is only a statistical trend for better results in cases with larger endometrial diameter comparing pregnant and non-pregnant patients (p = 0.0708). The results suggest that the uterine flow measurements might be helpful in selecting cycles for successful embryo transfer.

Cytotoxicity, differentiating activity and metabolism of tiazofurin in human neuroblastoma cells.

The IMP dehydrogenase inhibitor, tiazofurin (TR)-2-beta-D-ribofuranosylthiazole-4-carboxamide, which exhibited oncolytic activity in patients with chronic myelogenous leukaemia (CML) in blast crisis was found to inhibit the growth of human neuroblastoma SK-N-SH cells with an IC50 of 4.2 microM. TR treatment of cells perturbed nucleic acid and catecholamine pathways. As biochemical markers of TR action decreased cellular GTP pools, increased inosine and hypoxanthine concentrations and depleted dopamine content were found. Incubation of tumour specimens obtained from paediatric patients with grade-IV neuroblastoma with TR resulted in the formation of the active metabolite, thiazole-4-carboxamide adenine dinucleotide, in concentrations sufficient to inhibit tumour growth. Cytotoxic and biochemical effects of TR were enhanced by combining it with allopurinol (an inhibitor of xanthine dehydrogenase), and hypoxanthine (an alternate substrate for hypoxanthine-guanine phosphoribosyltransferase). Induction of transdifferentiation of SK-N-SH cells from a neuroblast to an epitheloid, substrate-adherent phenotype was more pronounced with TR than with all-trans-retinoic acid. Transdifferentiating treatment with TR resulted in a 2-fold-enhanced sensitivity towards adriamycin. However, differentiation with all-trans-retinoic acid rendered the cells more resistant to adriamycin. Our results suggest that TR might be a promising agent for the treatment of children suffering from neuroblastoma.

Potential for diagnosing imminent risk to appropriate- and small-for-gestational-age fetuses by Doppler sonographic examination of umbilical and cerebral arterial blood flow.

In a prospective study, 215 pregnancies of known gestational age were investigated using Doppler sonography. Multiple pregnancies and pregnancies complicated by fetal malformations were excluded. A pulsed Doppler machine was used to record the flow velocity waveforms in the umbilical artery (UA) and middle cerebral artery (MCA). The pulsatility index (PI) of both vessels and the ratio of PI UA to PI MCA were calculated. A total of 127 pregnancies ended in the birth of appropriate-for-gestational age babies with no perinatal problems; these formed the normal group (Group A). Of the 88 pregnancies which made up the risk group, 17 were appropriate-for-gestational age babies with perinatal problems (Group B), 55 were small-for-gestational-age babies with no perinatal problems (Group C), and 16 were small-for-gestational age babies with perinatal problems (Group D). Normal ranges were calculated based on the results for Group A; the measured values for the risk groups were then compared to these. There were highly significant differences between values obtained from the risk groups and those of Group A with the exception of the umbilical artery in Group B and the middle cerebral artery in Group C. The best results came from the values for MCA in Group B (sensitivity = 71%), UA in Group D (sensitivity = 75%), and the PI ratio UA : MCA in Group D (sensitivity = 81%). The sensitivity for the ratio in Group D increased to 93% if only the last measurement for each patient taken within 14 days of delivery was analyzed. A drop in the MCA PI in appropriate-for-gestational-age fetuses was the best indicator of imminent risk of hypoxemia. The PI ratio of UA : MCA is valuable in monitoring small-for-gestational-age fetuses, particularly those with high UA PI levels, as a rise in the ratio provides an early indication of fetal risk.

[Doppler ultrasound of the umbilical artery in fetuses with sonographically abnormal findings and/or chromosome abnormalities (corrected)]. / Doppler-Sonographie der Arteria umbilicalis bei Feten mit sonographisch auffälligem Befund und/oder Chromosomenanomalien [corrected].

We performed 77 Doppler blood flow studies of the umbilical artery in 45 foetuses with malformations and/or chromosomal abnormalities. 20 foetuses had chromosomal abnormalities and 34 records of the second and third trimester were analysed. In 25 foetuses with malformations, but without chromosomal abnormalities, 43 investigations were performed between 21st and 40th weeks of gestation. In the second trimester, 3 of 11 foetuses with chromosomal abnormalities had an absence of enddiastolic flow velocities, whereas the other foetuses had pulsatility indices within the range for foetuses with a normal karyotype. In the third trimester, 7 of 10 foetuses with chromosomal abnormalities had pathological Doppler findings. Four cases had absent or reversed enddiastolic (ARED) flow velocities. Altogether 10 of 13 foetuses beyond the 19th weeks of gestation had pathological Doppler findings (sensitivity = 77%). The structure and the function of the placenta is influenced by the abnormal karyotype, which is demonstrated by pathological Doppler findings. Only 3 of 43 investigations in foetuses with malformations but normal karyotype, showed abnormal PI values and there was no case of ARED flow. In a group of 24 foetuses with ARED flow, 6 foetuses had chromosomal abnormalities. All foetuses with malformations and ARED flow had an abnormal karyotype. Prenatal chromosome analyses of foetuses with suspicious sonographic findings, revealed a rate of 29% chromosomal abnormalities, nearly all of them with a maternal age under 35 years. Whereas Doppler sonography cannot exclude chromosomal abnormalities before the 20th weeks of gestation, there is a good correlation between chromosomal abnormalities and abnormal Doppler findings later on.(ABSTRACT TRUNCATED AT 250 WORDS)

[Complications of radical operation of uterine cancer. Closure of the peritoneal defects--yes or no?]. / Komplikationen nach Radikaloperation der Uteruskarzinome. Verschluss der Peritonealdefekte--ja oder nein?

The case reports of 70 patients (including 12 cases of endometrial carcinoma operated by the same method) were evaluated for postoperative complications such as pathological changes in the iv-pyelograms, incidence of haemorrhage or haematomas at the operation site, and for the frequency of lymphatic cysts. In addition, the amount of secretion and the duration of drainage were recorded. In 26 patients, the wounds of the parietal peritoneum were sutured, in 44 women, the pelvic peritoneum was left open after primary occlusion of the vaginal vault. If the two groups are compared with respect to the incidence of complications, the results are: pathologic postoperative ivP: 3.4:1; haemorrhage or haematomas: 5:1; lymphatic cysts: 1.6:1. The duration of drainage was almost the same in both groups (1.1:1), but the amount of liquid drained was less in the peritonealised group (0.5:1). These data and the fact, that the overall morbidity in the "open peritoneum" group was significantly lower, leads us to recommend strongly that leaving the pelvic peritoneum open provides evident advantages compared with the traditional procedure. In addition, a marked reduction of the operation time is achieved. Negative consequences, such as postoperative ileus, did not occur.

[What is the contribution of Doppler sonography of the umbilical artery in diagnosis of intrauterine growth retardation?]. / Was bringt die Dopplersonographie der Arteria umbilicalis bei der Diagnose einer intrauterinen Wachstumsretardierung?

Pulsed Dopplersonography of the umbilical artery was performed in 155 singleton high-risk pregnancies without malformations or chromosomal abnormalities. 59 foetuses were classified as foetuses with intrauterine growth retardation (IUGR). 46 of them had a birth weight below the tenth percentile. In 20 cases the pulsatility index (PI) was elevated (sensitivity: 44%). In all there were 50 neonates with a birth weight below the tenth percentile, 46 of whom were detected by biometry (sensitivity: 92%). 8 dystrophic neonates with a biometry that revealed IUGR were compromised by perinatal asphyxia. In six cases operative delivery was necessary and two cases with reversed diastolic flow ended in intrauterine foetal death. 7 of those foetuses had an elevated PI. The sensitivity of Dopplersonography in this group was 88%, the negative predictive value 97%. The positive predictive value with regard to a dystrophic neonate can be improved from 78% to 91%, if compared with biometry alone. Summing up, Dopplersonography of the umbilical artery can distinguish very well between IUGR foetuses at risk of perinatal morbidity or mortality and those IUGR foetuses with sufficient placental circulation who are, therefore, not at risk.

[Fetal cerebral and renal circulation--a longitudinal study in the 2d half of pregnancy]. / Untersuchungen des fetalen zerebralen und renalen Blutflusses--eine Longitudinalstudie in der zweiten Schwangerschaftshälfte.

In a prospective longitudinal study 34 women were subjected to the following investigations 4-weekly from the 23rd to the 41st week of pregnancy: Doppler sonography of the umbilical artery, arteria cerebri media (ACM) and arteria renalis (AR), fetal biometry, estimation of the amniotic fluid volume and cardiotocography (CTG). 30 pregnancies ended in the birth of normal weight babies with no perinatal problems and in 108 examinations blood flow velocity waveforms of high quality were recorded in each vessel. We calculated the pulsatility index (PI), which was always within the normal range for the umbilical artery. Regression analysis was used to derive the 90% confidence intervals for the PI of ACM and AR and the PI ratio AR/ACM. A linear relationship was found between the AR PI and gestational age, while the relationship between the ACM PI and gestational age is better described by a quadratic equation. In both vessels a fall in PI was observed with advancing gestation. In the renal artery waveforms with absence of end-diastolic flow velocities were recorded up to 34 weeks only. CTG was assessed by the Fischer score, which showed a highly significant, positive correlation with gestational age (r = 0.316), but no correlation with the PI of the middle cerebral artery. The amniotic fluid volume showed a negative correlation with gestational age (r = -0.19), but no correlation with the PI of the renal artery.

L-arginine reduces glomerular basement membrane collagen N epsilon-carboxymethyllysine in the diabetic db/db mouse.

The present study was carried out to examine the effect of L-arginine on advanced stage nonenzymatic glycosylation end products in glomerular basement membrane (GBM) as represented by carboxymethyllysine (CML). Twelve db/db mice were given a solution containing a daily dosage of L-arginine of 50 mg/kg body weight orally. Twelve db/db mice served as controls. At the end of the 4-months study period treated animals had significantly lower concentrations of CML (0.084 +/- 0.008, 0.071-0.098 nmol/mumol OH-proline; mean +/- SD, range, p less than 0.01) compared to untreated controls (0.11 +/- 0.018, 0.095-0.152 nmol/mumol OH-proline). In addition, there was a significant positive correlation between GBM thickness and concentrations of CML (r = 0.86, p less than 0.001). We conclude that reduction of CML concentrations in treated db/db mice possibly reflects a beneficial effect of L-arginine on advanced stage nonenzymatic glycosylation end-products in GBM. In addition, measuring CML concentrations might have future clinical implications as a noninvasive parameter for basement membrane thickening.

Spontaneous remission of urinary tract obstruction and ascites in a fetus with posterior urethral valves.

We report a case of posterior urethral valves with its typical sonographic findings. The initial diagnosis of an infravesical obstruction was made at 18 weeks gestation based on the finding of an enlarged fetal bladder and bilateral dilated renal pelves. Weekly observations showed no change in bladder size until 27 weeks gestation. At this time there was a significant increase in dilatation, the bladder wall was thickened and at 28 weeks a large amount of fetal ascites was diagnosed, but there was no oligohydramnios. Fetal urine investigations following ultrasound-guided puncture of the fetal bladder revealed hypotonic urine and adequate renal function. Hence no vesicoamniotic drainage was performed. At 32 weeks, spontaneous remission of ascites and reduction of the bladder dilatation were noted. The fetus was delivered vaginally at term. Follow-up of the newborn during the 1st year of life is reported. At the age of 1 year the infant shows good renal function with a serum creatinine of 0.33 mg/dl. This case shows that spontaneous remission of fetal urinary tract obstruction as a consequence of posterior urethral valves is possible. The sequence of events leading to spontaneous remission and the favorable outcome is discussed.

[Doppler ultrasound of the umbilical artery of the dystrophic child]. / Dopplersonographie der Arteria umbilicalis beim dystrophen Kind.

In a group of 810 singleton pregnancies without malformations or chromosomal abnormalities blood flow velocity wave forms of the umbilical artery were recorded in the third trimester by means of a pulsed duplex Doppler system. We calculated the pulsatility index (PI). 133 newborn with a birthweight below the 10th centile were classified as small-for-gestational-age (SGA) (prevalence: 16%). The sensitivity of the test (elevated PI) for these neonates is 52% and the specificity 97%, the positive predictive value is 78% and the negative predictive value 91%. Therefore, Doppler Sonography of the umbilical artery is not an appropriate screening test to identify SGA babies prenatally. The results for jeopardized SGA babies (caesarean section because of pathological CTG traces, transfer to the neonatal intensive care unit) are much better. 31 out of 133 belonged to that group. For these foetuses, the sensitivity of the test is 94% and the negative predictive value 97%. Hence, Doppler Sonography of the umbilical artery allows very well to identify the endangered SGA foetuses on the one hand and to exclude foetal jeopardy with a normal PI on the other.

[Holoprosencephaly: criteria and consequences for prenatal diagnosis]. / Holoprosenzephalie: Kriterien und Konsequenzen der pränatalen Diagnostik.

Two cases of prenatal diagnosis of holoprosencephaly are described. The characteristic sonographic findings in the second trimester were: microcephaly, absence of the midline echo, hypotelorism and typically flattened profile without sufficient configuration of the nose. Both foetuses had midline facial clefts, one of which was diagnosed prenatally. One case demonstrated a dorsal intracranial cyst. Analysis of the karyotype after foetal blood sampling and amniocentesis revealed translocation trisomy 13 in one case. The mother of this foetus had a balanced translocation 13/14. This foetus also had many extracranial abnormalities in contrast to the other foetus, which had a normal karyotype. Additionally we report of the prenatal diagnosis of a third case with cyclopia and trisomy 13. The findings of the autopsy of the foetuses are described and the criteria for prenatal diagnosis are compared to those found in the literature.

[The in vitro fertilization program in Klagenfurt]. / In-vitro-Fertilisationsprogramm in Klagenfurt.

690 infertile patients have been treated with IVF since 1984 in Klagenfurt. All patients who asked for IVF/ET treatment are included in this study without any selection. The data therefore show the effective chance to become pregnant. The majority of the patients was infertile due to tubal-factor, underwent two treatment cycles only and was stimulated with a simple clomid-scheme. Oocyte retrieval has been performed via laparoscope only in the beginning; for three years already it is done transvaginally under ultrasound control. Depending on the number of transferred embryos the pregnancy rate varies and reaches 35% in triple-transfers. Until now 140 clinical pregnancies could be achieved and 72 women gave birth to 78 healthy children. Therefore our patients can count on an average pregnancy rate of 20.3% and an 10.4 baby-take-home rate.

[Reference values for the pulsatility index and the resistance index of blood flow curves of the umbilical artery and fetal aorta in the 3d trimester]. / Referenzwerte für den Pulsatilitätsindex und den Resistance-Index von Blutflusskurven der Arteria umbilicalis und der fetalen Aorta im dritten Trimenon.

In 209 pregnancies without complications we recorded blood velocity waveforms of the umbilical artery and the foetal aorta between 29 and 42 weeks of gestation by means of a Duplex-pulsed Doppler system (umbilical artery: n = 276; foetal aorta: n = 244). We calculated the pulsatility index (PI) and the resistance index (RI). Both indices were normally distributed. The regression lines and reference ranges for the 95% confidence intervals are shown. The PI as well as the RI of waveforms of the umbilical artery demonstrated a significant fall with increasing gestation. The PI of the foetal aorta demonstrated a gentle, non-significant fall; RI showed no changes throughout the third trimester. Comparisons with the reference ranges published by other authors are discussed.

[The value of fetal blood flow measurements in intrauterine growth retardation in comparison with E3 and human placental lactogen determinations]. / Wertigkeit von fetalen Blutflussmessungen bei intrauteriner Wachstumsretardierung im Vergleich zu E3- und HPL-Bestimmungen.

In 110 pregnancies, repeated examinations of unconjugated E3 and HPL levels in maternal serum were carried out as well as repeated duplex pulsed doppler flow measurements in the umbilical artery and the fetal aorta. In 30 cases the fetuses were suspected to be growth retarded (group A), 5 small for date babies were not detected by routine ultrasound (group B) and 75 were normal control cases (group C). 17 fetuses of group A proved to be really SGA-babies (birthweight less than 10. percentile). The evaluation of the results indicates a higher sensitivity of the flow measurements in the diagnosis of growth retardation compared with the hormonal parameters (flow: 65%, E3: 12%, HPL: 29%). Above all, Doppler sonography is very reliable in distinguishing between growth retarded fetuses, at risk or not at risk.

Doppler blood flow velocity waveforms in the fetal renal artery.

In 19 out of 20 human fetuses we recorded blood velocity waveforms in the renal artery by means of a duplex Doppler sector scanner. One fetus was at 22 weeks gestation, 7 fetuses were between 32 and 35 weeks, and 12 fetuses between 36 and 40 weeks. There was no evidence of intrauterine growth retardation and there was a normal quantity of amniotic fluid in all pregnancies. We also recorded waveforms in the umbilical artery, the descending aorta, and the internal carotid artery. The RI in these vessels showed normal values in all cases. There was no end-diastolic flow in four of the seven fetuses studied at 32 to 35 weeks gestation. The mean RI of fetuses with end-diastolic flow was 0.86 (SD 0.03). The interpretations of these results, and ideas for future studies are discussed.

[Comparison of the clinical value of 2 frequently used indices of fetal blood flow analysis (pulsatility index PI and resistance index RI)]. / Vergleich der klinischen Wertigkeit zweier zur fetalen Blutflussanalyse häufig verwendeter Indices (Pulsatilitätsindex PI und Resistanceindex RI).

249 blood-flow measurements were carried out with pulsed Doppler-ultrasound in the umbilical arteries and the descending aorta of 188 fetuses. The PI and the RI of the recorded flowpatterns were calculated. In a retrospective study we then calculated the validity of the prediction of a pathological fetal outcome, i.e. a SGA-fetus and/or perinatal morbidity, for both indices. The sensitivity of the PI is 63%, the specificity was 98%, the sensitivity of the RI was 40%, and the specificity 98%. Therefore the sensitivity of the PI is significantly higher than that of the RI (p less than 0.05). In the second, prospective part of the study these results could be verified by means of an equivalent number of measurements to the first group (n = 249) with 178 fetuses. All the jeopardized fetuses with IUGR and perinatal morbidity (n = 13) were detected by an increased PI, but even in this group the sensitivity of the RI was only 54%. The possible reasons for these results are discussed, taking into account the different characteristics of the two indices and the influence of the heart rate on both of them.