Electron-Beam-Initiated Crosslinking of Methacrylated Alginate and Diacrylated Poly(ethylene glycol) Hydrogels

An ideal wound dressing not only needs to absorb excess exudate but should also allow for a moist wound-healing environment as well as being mechanically strong. Such a dressing can be achieved by combining both a natural (alginate) and synthetic (poly(ethylene glycol) polymer. Interestingly, using an electron beam on (meth)acrylated polymers allows their covalent crosslinking without the use of toxic photo-initiators. The goal of this work was to crosslink alginate at different methacrylation degrees (26.1 and 53.5% of the repeating units) with diacrylated poly(ethylene glycol) (PEGDA) using electron-beam irradiation at different doses to create strong, transparent hydrogels. Infrared spectroscopy showed that both polymers were homogeneously distributed within the irradiated hydrogel. Rheology showed that the addition of PEGDA into alginate with a high degree of methacrylation and a polymer concentration of 6 wt/v% improved the storage modulus up to 15,867 ± 1102 Pa. Gel fractions > 90% and swelling ratios ranging from 10 to 250 times its own weight were obtained. It was observed that the higher the storage modulus, the more limited the swelling ratio due to a more crosslinked network. Finally, all species were highly transparent, with transmittance values > 80%. This may be beneficial for the visual inspection of healing progression. Furthermore, these polymers may eventually be used as carriers of photosensitizers, which is favorable in applications such as photodynamic therapy.

Photosensitizer-loaded hydrogels for photodynamic inactivation of multirestistant bacteria in wounds

Photodynamic treatment is a promising tool for the therapy of multidrug-resistant bacteria. In this study, we highlight photosensitizer-loaded hydrogels as an application system for infected wounds. The poly(ethylene glycol) diacrylate-based and electron beam-polymerized hydrogels were mechanically stable and transparent. They were loaded with two photoactive, porphyrin-based drugs - tetrakis(1 methylpyridinium-4-yl)porphyrin p-toluenesulfonate (TMPyP) and tetrahydroporphyrin - p toluenesulfonate (THPTS). The hydrogels released a sufficient amount of the photosensitizers (up to 300 μmol l-1), relevant for efficiency. The antimicrobial effectivity of loaded hydrogels was investigated in a tissue-like system as well as in a liquid system against a multiresistant Escherichia coli. In both systems, light induced eradication was possible. In contrast, hydrogels alone showed only minor antimicrobial activity. Furthermore, the loaded hydrogels were successfully tested against seven multidrug-resistant bacterial strains, namely Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli and Achromobacter xylosoxidans. The eradication of these pathogens, except A. xylosoxidans, was successfully demonstrated. In general, TMPyP-loaded hydrogels were more effective than THPTS-loaded ones. Nevertheless, both photosensitizers displayed effectivity against all investigated bacteria strains. Taken together, our data demonstrate that photosensitizer-loaded hydrogels are a promising new tool to improve the treatment of wounds infected with problematic bacterial pathogens.

Controlled Electron-Beam Synthesis of Transparent Hydrogels for Drug Delivery Applications

In this study, we highlight hydrogels prepared by electron-beam polymerization. In general, the electron-beam-polymerized hydrogels showed improved mechanical and optical transmittances compared to the conventional UV-cured hydrogels. They were more elastic and had a higher crosslinking density. Additionally, they were transparent over a broader wavelength range. The dependence of the mechanical and optical properties of the hydrogels on the number of single differential and total irradiation doses was analyzed in detail. The hydrogels were prepared for usage as a drug delivery material with methylene blue as a drug model. In the first set of experiments, methylene blue was loaded reversibly after the hydrogel synthesis. Electron-beam-polymerized hydrogels incorporated twice as much methylene blue compared to the UV-polymerized gels. Furthermore, the release of the model drug was found to depend on the crosslinking degree of the hydrogels. In addition, electron-beam polymerization enabled the irreversible binding of the drug molecules if they were mixed with monomers before polymerization.

Photocatalytic degradation and toxicity evaluation of diclofenac by nanotubular titanium dioxide–PES membrane in a static and continuous setup

Diclofenac is a commonly used anti-inflammatory drug, which has been found in surface waters. TiO₂ nanotubes with a polymer microfiltration membrane showed high photocatalytic degradation of diclofenac combined with an excellent membrane performance and long term stability.

S3-Guidelines for the Treatment of Inflammatory Breast Disease during the Lactation Period: AWMF Guidelines, Registry No. 015/071 (short version) AWMF Leitlinien-Register Nr. 015/071 (Kurzfassung)

Breastfeeding is widely acknowledged to be the best and most complete form of nutrition for healthy infants born at term and is associated with numerous benefits in terms of infants' health, growth, immunity and development. However, breastfeeding problems often result in early weaning. Standardized treatment recommendations for breastfeeding-related diseases are necessary to optimize the care offered to breastfeeding women. Evidence and consensus based guidelines for the treatment of puerperal mastitis, sore nipples, engorgement and blocked ducts were developed on the initiative of the National Breastfeeding Committee. These guidelines were developed in accordance with the criteria set up by the Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF), the Association of Scientific Medical Societies in Germany. The recommendations were drawn up by an interdisciplinary group of experts and were based on a systematic search and evaluation of the literature but also took clinical experience into account. Additionally good clinical practice (GCP) in terms of expert opinion was formulated in cases where scientific investigations could not be performed or were not aimed for. This article presents a summary of the recommendations of the S3-guidelines.

[Changes in MR images in pre-eclampsia and eclampsia]

BACKGROUND

Pre-eclampsia affects 2% of pregnancies. This multisystem disorder is a major cause of maternal, foetal and neonatal mortality and morbidity. Neurological manifestations of eclampsia are headache, nausea, vomiting, cortical blindness and recurrent seizures.

OBJECTIVE

The purpose of this study was to determine whether the neurological symptoms correlate with MR imaging findings.

RESULTS

In a patient with eclamptic seizure and another one with blindness due to pre-eclampsia, the white matter hyperintensities on T (2)-weighted MR and FLAIRsequence images could be demonstrated in the occipital region and in the basal ganglia. Within 3-5 days all neurological symptoms and radiological abnormalities had resolved.

CONCLUSION

These cerebral lesions could be classified as posterior reversible encephalopathy syndrome (PRES) or as reversible leukoencephalopathy syndrome (PLES). Thus, MRI supports differential diagnosis regarding non pregnancy-related cerebral disease and can be helpful for therapy planning in cases of pre-eclampsia.

The Use of i. v. Bisphosphonate in Pregnancy-Associated Osteoporosis - Case Study

OBJECTIVE

Diagnosis of pregnancy-associated osteoporosis is often delayed and therapeutic interventions insufficient.

STUDY DESIGN

A 28-year-old patient (BMI=18.6) with no additional risks for osteoporosis experienced acute lumbosacral pain two months postpartum, while lactating. After conservative therapy, thoracic and lumbar spine were X-rayed: severe pregnancy-associated osteoporosis with vertebral fractures was diagnosed. 2-year treatment with i. v. bisphosphonate ibandronate was initiated (2 mg every 3 months) and calcium and vitamin D supplementation.

RESULTS

Rapid improvement was observed. Conclusion: In cases with multiple fractures i. v. bisphosphonate leads to substantial decrease of symptoms and further fractures and significant increase of bone mass density (BMD).

CONCLUSION

In severe cases of pregnancy-associated osteoporosis with multiple fractures i. v. biphosphonate therapy leads to a decrease of symptoms and fracture risk and an increase of bone mass density (BMD).

[Quality of data transfer in perinatal data -- experience of a centre]

BACKGROUND

A sufficient quality of data transfer from written patient records to electronic data processing is a precondition for a reasonable usage of perinatal data. However the quality of data transfer of the almost 200 characteristics routinely recorded at each delivery is largely unknown.

MATERIALS AND METHODS

The quality of data transfer of 33 characteristics in 350 randomly selected singleton deliveries of the women's clinic of the University of Marburg from 2002 and 2003 has been checked by comparing electronically recorded data with the original written documents.

RESULTS

The quality of data transfer of the tested characteristics turned out to be heterogeneous. Characteristics necessary to calculate quality indicators show a very high data quality when excluding the characteristic attendance of a paediatrician. The quality of data transfer of characteristics denoting time as well as blood gas analysis are heterogeneous. Characteristics with a low quality of data transfer are associated with ambiguous instructions, the fact that the coding obstetrician is not dealing in the first instance with the item being encoded and the characteristics are of no immediate relevance for delivery, as well as difficult application of the software.

CONCLUSION

The quality of data transfer of the characteristics collected in perinatal surveys needs to be validated. The type and amount of data being collected should be reassessed considering improvements of data quality.

Fetal lung development in pregnancies of diabetic women assessed by quantitative ultrasonic tissue characterization

OBJECTIVES

This study was performed to compare quantitative ultrasonic tissue characterization of the fetal lung at different gestational ages in uncontrolled diabetic patients with that in normal uncomplicated pregnancies.

METHODS

A total of 44 women at 24-37 weeks' gestation with the diagnosis of diabetes in pregnancy were enrolled. Data were compared to those of the control group, which consisted of 140 women with uncomplicated pregnancies of the same gestational age. Longitudinal and transverse sections of the fetal thorax and upper abdomen were examined. A region of interest of constant size was defined and the tissue-specific gray scale was determined by using interactive software.

RESULTS

Compared with normal pregnancies, fetal lungs of diabetic pregnancies have a higher echogenicity between 28 and 37 weeks of gestation. The lung mean gray values (MGV) only differed significantly between 30 and 31 weeks of gestation in the group with diabetes (P = 0.033) compared to the control group. The MGV of the liver in diabetic and normal pregnancies is similar during pregnancy, significant differences being found only at 30-31 weeks of gestation (P = 0.038). The lung-to-liver ratio in the control group showed a significant increase from 24 to 31 weeks and a slight non-significant decrease after 31 weeks. The ratio in the group with diabetes increased slightly up to week 33 and decreased slightly afterwards.

CONCLUSION

Fetal lung MGV in uncontrolled diabetic pregnancies compared to that in uncomplicated pregnancies differs significantly only between 30 and 31 weeks of gestation.

[Dynamics of thrombin-antithrombin-III complex (TAT-III) and prothrombin fragments F1 + 2 during labour with and without aprotinin administration]

OBJECTIVE

The aim of this study was to determine if aprotinin could affect postpartal fibrinolysis when given at the latest 15 min before delivery and if there is a difference between normal delivery and caesarean section. Furthermore we wanted to examine if the thrombin-antithrombin-III-complex (TAT-III) and prothrombin fragments F1 + 2 changed in the peripartal period and if prethrombotic stages could be recognized.

PATIENTS AND METHODS

84 patients (15 - 44 years of age) have been examined (41 normal deliveries, 43 cesarean sections). After giving informed consent and randomization, 30 of these patients were administered 1 Mio KIE aprotinin (Trasylol(R)) at the latest 15 min before delivery (15 normal deliveries, 15 cesarean sections). The results of TAT-III, prothrombin fragments F1 + 2, factor VIII and partial thromboplastin-time (PTT) were collected shortly before and after delivery and 30 and 120 min after detachment of the placenta.

RESULTS

Normal deliveries without aprotinin showed a significant increase of TAT-III and an evident increase of prothrombin fragments F1 + 2. After administration of aprotinin this increase was significantly lower. The increase of TAT-III and prothrombin fragments F1 + 2 in patients with caesarean sections was evidently lower than in normal deliveries and was not influenced significantly by aprotinin. Factor VIII and partial thromboplastin time (PTT) showed no relevant changes in all study groups.

DISCUSSION AND CONCLUSION

The consumption of coagulation and fibrinolysis factors induced by delivery of the child and detachment of the placenta can be reduced after administration of aprotinin given at the latest 10 - 18 min before partus. This could be used in therapy and prophylactic treatment in high-risk patients (e. g., pre-eclampsia, HELLP syndrome, etc.).

Evaluierung der Reproduzierbarkeit dopplersonographischer Messungen in der Geburtshilfe

BACKGROUND

Are obstetric doppler ultrasonographic measurements of the fetal and maternal flow parameters reproducible?

PATIENTS AND METHODS

For internal quality management, doppler ultrasonographic measurements were performed on 81 patients (random screening sample) with an Acuson Sequoia Ultrasound at the Universitätsfrauenklinik Marburg. Successively two experienced investigators measured the umbilical artery, medial cerebral artery, and the uterine arteries. The correlation between the measurements of the two investigators was presented in a spread chart. In order to exclude systematic differences between the measurements, linear regression was analyzed and the distance to the abscissa was calculated. A relative divergence of more than 20% was determined as a non corresponding measurement.

RESULTS

The distance of the linear regression to the abscissa was calculated for the four vessels: umbilical artery 0.4 (95% CI; 0.124 - 0.486), medial cerebral artery 0.9 (95% CI; 0.534 - 1.264), right uterine artery 0.2 (95% CI; 0.124 - 0.305), and left uterine artery 0.2 (95% CI; 0.121 - 0.317). Concerning the four arteries, a divergence of more than 20% between the two investigators was found: umbilical artery 16%, medial cerebral artery 42%, right uterine artery 28%, and left uterine artery 37%.

CONCLUSIONS

Because the interobserver variability was surprisingly high and acceptable correlation could be stated only for the umbilical artery, internal quality standards are essential. Routine use of different devices should be made after careful consideration only, especially if clinical decisions are to be based on them.

[Changes of fibrinolysis during labour with and without aprotinin application]

OBJECTIVE

The aim of this study was to determine (a) if alpha-2-antiplasmin, plasminogen and plasminogen-activator-inhibitors (PAI 1 - 4) change in the peripartal period, (b) if these changes are explainable by the detachment of the placenta and the release of coagulation factors, and (c) if aprotinin could affect postpartal fibrinolysis when given shortly before delivery.

PATIENTS AND METHODS

84 patients have been examined (41 normal deliveries, 43 cesarean sections). After informed consent and randomization, 30 of these patients were administered 1 million KIU aprotinin (Trasylol(R)) at the latest 15 minutes before delivery (15 normal deliveries, 15 cesarean sections). The results of PAI (1 - 4), alpha-2-antiplasmin and plasminogen were collected shortly before and after delivery and 30 and 120 min after detachment of the placenta.

RESULTS

Normal deliveries and cesarean sections without aprotinin showed an evident decrease of PAI (1 - 4) after delivery while alpha-2-antiplasmin and plasminogen values did not change. After administration of aprotinin the activity of PAI (1 - 4) increased slightly after labour in normal deliveries and cesarean sections and then slowly decreased later. alpha-2-Antiplasmin levels increased post partum and then decreased to the original values. Plasminogen did not change. There were no significant differences between normal deliveries and cesarean sections with regard to the three parameters studied in this work.

DISCUSSION AND CONCLUSION

Changes in PAI (1 - 4) and alpha-2-antiplasmin after administration of aprotinin could be the result of a minimal demand on the fibrinolytic system. Finally, aprotinin can reduce the consumption of coagulation and fibrinolysis factors induced by detachment of the placenta. This could be used in therapy and prophylactic treatment in high-risk patients (e.g., pre-eclampsia, HELLP syndrome, etc.).

[Fetal pulse oximetry during risk deliveries in German clinics--a representative national survey in 81 obstetric departments]

BACKGROUND

The development of a new technique to evaluate the normal fetal acid-base balance in risk deliveries with pathological fetal heart rate has been seen with great expectations over the last years. The aim of this representative survey was to ask for the actual status of the fetal pulse oximetry in clinical use in German delivery rooms and to analyze hopes, expectations and system errors. PATIENTS RESPECTIVELY AND METHODS: Collecting data were done by a representative, time limited anonymous questionnaire in all German clinics who used Nellcors fetal pulse oximetry N-400 in measuring fetal arterial saturation in the years 1995 - 1999 during risk deliveries with non-reassuring fetal heart rate.

RESULTS

With 66,6 % of the departments participating a number of 54 clinics returned the questionnaires. An average of 4.5 times per month fetal pulse oximetry was used per clinic and in over 90 % of all cases the handling and fixation of the sensor was without problems. There is qualified staff in every clinic and regarding the satisfaction with this system an average note of 2.8 was assigned. Fetal pulse oximetry will be established in some years to replace fetal blood analysis and to reduce operative deliveries. Technical problems in cases of insufficient sensor fixation at the fetal head and with the re-sterilization of fetal sensors must be solved in the future.

CONCLUSIONS

Fetal pulse oximetry will be incorporated as the third method of monitoring the fetus during labor.

[Effect of modified labor posture on oxygenation of the fetus--a pulse oximetry study]

BACKGROUND

The evaluation of the birth position and its effects on maternal and fetal wellbeing has been a topic of perinatal research over the last decades. The aim of our observational study was to determine the effects of a modified and vertical maternal position on fetal oxygen saturation measured by pulse oximetry.

METHODS

Fetal oxygen saturation was measured by pulse oximetry in 56 labouring women randomly and successively adopting the supine position in 96.4%, the sitting position in 25.0%, the standing position in 14.3% and the prone position in 12.5%. The statistical analysis addressed the integrated 10 minutes period of SpO2 registrations before versus after adopting the modified position. Furthermore the mean values and the standard deviation (SD) for the total registration periods of different birth position was calculated.

RESULTS

While the supine position induced a reduction in oxygen saturation, sitting and prone position were favorable for fetal oxygenation as compared to horizontal position.

DISCUSSION

These findings implicate a clinical benefit of the modified birth position.

24 hour-CTG monitoring: comparison of normal pregnancies and pregnancies with placenta insufficiency

AIMS

Routinely antepartal CTG will be recorded for 30 minutes to obtain normal resting phases, a decrease of irregulatory due to hypoxia or to differentiate these from each other. In case of early onset of hypoxia first pathological findings might only be seen by chance in incidentally recorded CTG. The goal of this study was, if a continuous 24 hour-CTG will allow an earlier detection of beginning hypoxia in case of placental insufficiency compared to a routine CTG of 30 minutes.

METHODS

21 normal pregnancies and 17 patients with placental insufficiency of > or = 36 weeks had 24 hour-CTG's by means of telemetry. In both study groups fetal heart rate (FHR) tracing included a full qualitative and quantitative description. Comparison of the results of both groups was done to look for early signs of pathological findings concerning reduced fetal well-being.

RESULTS

In comparison to normal pregnancies patients with placental insufficiency had in 4.5% oscillation frequency type A and an increase of saltatory and silent oscillation. The number of accelerations and Dip 0 was significantly reduced as well as accelerations in combination with undulatory oscillation. Baseline tachycardia and bradycardia showed significantly increasing quantity.

CONCLUSIONS

24 hour-CTG is a good screening method to detect early onset of hypoxia in case of beginning placental insufficiency. The failure to find any clinically significant difference in the diurnal variation of both groups suggests, that less than 24 hour testing is required. 8 hour-CTG could be a compromise and a big help to detect a fetus at risk earlier.

Changes in lymphocyte subsets during pregnancy and post-partum in cases of beginning eclampsia

AIMS

The goal of the present retrospective study was to examine the peripheral blood lymphocytes for expression of phenotypic and activation markers concerning the development of hypertension in pregnancy.

METHODS

16 women (aged 25-43 years; mean 35.1) developing hypertension in the third trimester (week 25-34) have had blood samples taken in the first (< 14 weeks), the second (week 14-23), the third trimester (week 24-35), in late pregnancy (week 36-termination of pregnancy) and within 1 week post-partum, The control group consisted of 16 age-matched pregnant healthy women, who underwent the same regime. All blood samples were taken in the morning, stored at room temperature and stained within 6 hours and measured within 24 hours. Kruskal-Wallis analysis of variance between both groups was done with multiple comparison according to Dunn.

RESULTS

Comparing both groups, the total white cell count was significantly increased in all pregnancies and post-partum. In case of hypertension in pregnancy the cell numbers of suppressor/cytotoxic (CD 8+) and CD 56(+)-activated T cells showed a significant increase in the first trimester (< 14 weeks) [p < 0.05] and decreased thereafter to normal values. In the second trimester (week 14-23) helper/inducer lymphocytes and CD 56+/CD 3+ lymphocytes decreased in case of pre-ecclampsia and cytotoxic lymphocytes elevated [p < 0.05]. In the third trimester (week 24-35) there was no difference in both study groups and in late pregnancy (week 36-termination) there were only small differences without statistical significance. Within 1 week postnatal the value of Il-2 receptor T lymphocytes decreased in the group of pre-eclampsia in comparison to normal pregnancies [p < 0.05].

CONCLUSIONS

Regarding the major changes in activated T cells in both study groups no specific pattern of lymphocyte subsets in case of pre-eclampsia could be found in comparison to healthy pregnant women. Further investigations should focus on functional activation and/or suppression of the cellular immune system. Perhaps this could lead to a screening test for pre-eclampsia in future, which is non-invasive for the patient and economic for our social community because it might reduce medical costs.

[Detection of fetal cells in maternal blood with magnetically activated cell sorging (MACS) and EGF receptor antibody MAb 425]

BACKGROUND

In this study separation and enrichment of fetal trophoblastcells have been investigated in venous blood of pregnant women, in order to see, if this non-risk method can replace invasive methods of gaining fetal cells for antenatal diagnosis.

MATERIAL AND METHODS

First investigation of antigen-patterns of fetal cells, placenta-tissue and leucocytes as well as of different MAb 425-concentrations in chorioncells, A-431-cells and leucocytes was done, thereafter staining of A 431-cells, staining and evidence of A 431-leucocytes mixtures (group 1: n = 11), staining of chorioncells, staining and evidence of chorioncell-leucocytes mixtures (group 2: n = 13), staining and evidence of leucocyctes of nonpregnant (group 3: n = 18) and pregnant women (group 4: n = 6). A FACScan was used. Antigen patterns of fetal cells, placenta tissue and leucocytes were tested by means of specific antibodies.

RESULTS

Almost all chorioncell-cultures have been EGF-receptor positive, whereas leucocytes were negative. For separation of trophoblastcells the EGF-receptor was the most suitable. 18 leucocyte samples of non-pregnant and 6 of pregnant women were tested. There were no significant differences either concerning staining with MAb 425 or in evidence in the MiniMACS. In pregnant women there was no sufficient number of EGF-receptor-positive cells available, in order to recognize, if these cells were of fetal origin.

CONCLUSIONS

Before trophoblastcells could be used for antenatal diagnosis potential influences concerning presence time and separation of these cells should be investigated.

DISCUSSION

We did not have enough fetal cells for further cytogenetic investigations. One reason for not enough evidence of fetal cells could be a lack of capacity of the MiniMACS. There were probably none or not enough trophoblastcells in the maternal blood. Which parameters could be of influence, is not yet known.

The prediction of fetal acidosis by means of intrapartum fetal pulse oximetry

OBJECTIVES

The study's objectives were to verify a threshold value for fetal arterial oxygen saturation as the critical boundary for fetal compromise during labor and to investigate a method of predicting acidosis caused by hypoxemia.

STUDY DESIGN

In a multicenter study involving 3 German obstetric centers, a total of 400 deliveries were monitored by fetal pulse oximetry (Nellcor-Puritan-Bennett Model N-400 Oxygen Saturation Monitor and FS-14 Sensor; Nellcor, Inc, Pleasanton, Calif). The durations of low (</=30%), medium (31%-60%), and high (>60%) fetal arterial oxygen saturations during the measurement were compared between neonates with a pH <7.15 versus >/=7.15 and a base excess <-12 mmol/L versus >-12 mmol/L in the umbilical artery post partum and in neonates with an Apgar score <7 versus >/=7 by Mann-Whitney U test. In 121 of the pulse oximetry measurements the durations of low, medium, and high fetal arterial oxygen saturations were measured from one fetal scalp blood sampling to the next and correlated with the change of scalp blood pH between samplings. Multiple regression analysis was performed to estimate the expected change of pH between 2 fetal scalp blood samplings, and receiver operating characteristic analysis was done to define a minimum duration of low fetal arterial oxygen saturation values to exclude or predict a significant decline of pH.

RESULTS

Neonates with a 1-minute Apgar score <7 differed from those with 1-minute Apgar score >/=7 significantly in the duration of low fetal arterial oxygen saturation but not in the durations of medium and high fetal arterial oxygen saturations. The duration of low fetal arterial oxygen saturation had been significantly longer in children with pH <7.15 or base excess <-12 mmol/L in the umbilical artery compared with those with a pH >/=7.15 or base excess >/=-12 mmol/L. The duration of high fetal arterial oxygen saturation was significantly shorter for children with a pH <7.15 or base excess <12 mmol/L than for those with a pH >/=7.15 or base excess >/=12 mmol/L. There was no difference in the groups with respect to the duration of medium fetal arterial oxygen saturation values. The duration of low fetal arterial oxygen saturation proved to be the best predictor of a decline of scalp pH between 2 fetal scalp blood samples. The pH declined significantly with a longer duration of low fetal arterial oxygen saturation (0.02 per 10 minutes). No decrease of pH by more than 0.05 was observed unless fetal arterial oxygen saturation had remained at </=30% for >/=10 minutes.

CONCLUSION

An arterial oxygen saturation of 30% was confirmed as the critical boundary for fetal compromise during labor. The development of acidosis seems to be predictable by the duration of hypoxemia, as indicated by fetal arterial oxygen saturation </=30%.

Predictive agreement between the fetal arterial oxygen saturation and fetal scalp pH: results of the German multicenter study

OBJECTIVE

To discuss and substantiate the 30% critical threshold of fetal arterial oxygen saturation and to complete the puzzle with low fetal arterial oxygen saturation and low scalp pH data, scalp samples have been performed while fetal arterial oxygen saturation registration during labor was in place and while the saturation was < or = 30%.

STUDY DESIGN

Between 1993 and 1996, 46 term fetuses during active labor had parallel arterial oxygen saturation registration by pulse oximetry combined with cardiotocograph. They include patients in whom the saturation was < or = 30% for at least 10 minutes. In these cases scalp pH sample values have been obtained simultaneously. Outcome data, Apgar scores, cord gases, and whether the infants were transferred to the neonatal intensive care unit have been examined. Compared with this, there were other cases during labor that had also parallel fetal arterial oxygen saturation and cardiotocographic registration, where the saturation was > 30%. Also in these cases scalp pH was determined to support and demonstrate the predictive value of fetal arterial oxygen saturation for scalp pH, especially in the low ranges. All 46 fetuses were evaluated during periods of nonreassuring cardiotocograph with Nellcor N-400 Fetal Oxygen Saturation Monitoring Systems and FS 14 B sensors in a multicenter study involving three German obstetric centers. Receiver operating characteristic analysis was done on all raw data, as well as the receiver operating characteristic curve from the preceding analysis.

RESULTS

These data validate the critical threshold of 30% fetal arterial oxygen saturation and show an extremely good separation of "good" versus "bad" at a fetal arterial oxygen saturation of 30%, especially when seen in conjunction with data points that are > 7.20. Data at < or = 7.20 scalp pH and < 30% fetal arterial oxygen saturation can be a big help in calculating the sensitivity and specificity of fetal arterial oxygen saturation in predicting neonatal outcome (e.g., Apgar score, cord pH).

CONCLUSION

Low fetal arterial oxygen saturation data of < 30% for at least 10 minutes or longer correlate significantly with low scalp pH values and have a predictive value concerning fetal outcome.

Changes in lymphocyte subsets during normal pregnancy

Peripheral blood lymphocytes from healthy women were studied during pregnancy and postnatally, and were compared with lymphocytes from an age-matched non-pregnant control group. Compared with non-pregnant women, the total white cell count was significantly increased at all pregnancies and also post-partum. In pregnancy the absolute number and percentage of T lymphocytes was slightly elevated while almost no changes in B cells were found. No significant changes were found in the percentage of suppressor/cytotoxic (CD8+), of helper/inducer (CD4+) T lymphocytes, nor of CD4+/CD8+ ratio at any stage of pregnancy and puerperium. The most remarkable changes of the immune system occurred in the group of HLA-DR+ and CD56+ activated T cells. The cell numbers showed a significant increase in the first trimester (< 14 weeks) and decreased slightly from stage to stage. Lower values in NK (natural killer) cells and higher levels of IL-2 receptor positive T lymphocytes did not reach significant levels of change.

[The resorptive behavior of a low-molecular weight humic substance after a single oral administration to the rat]

By labeling HS 1500 with a radioactive 14C, it was proven that after oral application and under certain circumstances, low amounts of low molecular humic acids are for a short time absorbed from the gastrointestinal tract. But the biological availability of the substance is very low (less than 0.1% of the applied high doses). The plasma concentration curve assumes a first order kinetic for invasion and excretion. After oral application of 500 mg/kg b.w. HS 1500 the half life period was 1.5 hours and maximum plasma concentration was 3 micrograms/ml. The result obtained indicate that HS 1500 is toxicological riskless after oral administration. Taking into account the pharmacokinetic data, residues of the substance in animal tissues can be ruled out with high significance.

[Balloon mitral valve commissurotomy in pregnancy]

HISTORY AND CLINICAL FINDINGS

A 31-year-old woman with known postrheumatic mitral valve stenosis developed for the first time left heart failure in the 19th week of her fifth pregnancy. After intensive drug treatment she was in stage 3 (New York Heart Association classification). Apart from that the patient was in a good general condition and obstetrical status was according to the estimated duration of pregnancy. Auscultation revealed an apical diastolic murmur and mitral opening snap.

INVESTIGATIONS

Echocardiography demonstrated a mitral valve opening area of 0.85 cm2 (pressure-half time method); the mean gradient was 19 mm Hg.

TREATMENT AND COURSE

Because of the severity of the findings a percutaneous transvenous balloon valvotomy (according to Inoue) was performed in the 27th week of pregnancy, after careful lead shielding of abdomen and pelvis. Radiological screening time was 10 min. The invasively measured transvalvar pressure gradient was reduced from 28 to 4 mm Hg, echocardiographically determined mitral opening area increased to 1.5 cm2. Delivery was induced in the 36th week of pregnancy because of third-degree renal pelvis congestion. A healthy child, weighing 2850 g was delivered vaginally.

CONCLUSION

High-grade symptomatic mitral stenosis can, if necessary, be treated with a low-risk to mother and child by percutaneous balloon valvotomy.

[The effect of a low molecular weight synthetic humic substance on pre- and postnatal development in rats]

The influence of a low molecular synthetic humic substance (HS 1500) on pre- and postnatal development of rats was investigated. After oral application of 1000 mg/kg and 2000 mg/kg b. w. HS 1500 during the period of organogenesis (6th to 15th day p. c.) and from 16th day p. c. up to weaning neither adverse effects in the mothers nor in the fetuses were reported. The occurrence of a single malformation (gastroschisis) after application of 1000 mg/kg b. w. from day 6 to 15 of pregnancy, few ossifications of phalanges and differences in swimming behaviour are not regarded as the effect of the substance. In conclusion, the oral use of HS 1500 in the treatment of gastrointestinal diseases in animals during pregnancy is regarded to be riskless.

Immunmodulating cytokines induce term and preterm parturition

The aim of our study was to investigate if cytokines, which are able to cause preterm delivery is case of intraamniotic infection, also participate in the mechanisms of normal term labor. Therefore we estimated cytokine concentrations in cercicovaginal secretions of 96 patients, divided into four different collectives. In collective A (women with spontaneous term labor) cytokine concentrations raised from a median level of 278 pg/ml for Il-1 beta and 263 pg/ml for Il-6 in early term labor to a median level of 3351 pg/ml for Il-1 beta and 39,442 pg/ml for Il-6 at complete cervical dilatation. TNF-alpha-exclusively appeared after spontaneous rupture of fetal membranes. In collective B and C (women with preterm rupture of fetal membranes) cytokine concentrations declined from a maximum level of 1425 pg/ml for TNF-alpha, 12,982 pg/ml for Il-1 beta and 29,727 pg/ml for Il-6 soon after preterm rupture of membranes to a minimum level of 93 pg/ml for TNF-alpha, 851 pg/ml for Il-1 beta and 780 pg/ml for Il-6 with remission of labor in case of successful tocolytic treatment. High concentrations reappeared with the onset of labor, unresponsive to tocolysis. In collective D (women with intact membranes) TNF-alpha was not detectable and Il-1 beta and II-6 appeared exclusively in the presence of labor. Our results suggest, that normal term labor may be controlled by biochemical processes, similar to infection-associated signal transduction, which is commonly accepted to induce preterm labor.

[The effect of a low molecular weight synthetic humic substance on selected reproductive parameters of male rats]

Influences of the low molecular humic substance HS 1500 on parameters of organs (testis weight, epididymis weight), FSH-, and LH-levels in plasma as well as on the spermatogenesis of male rats were studied. After a daily oral application of 1000 mg/kg b.w. and 2000 mg/kg b.w., respectively over a period of 60 days (40th to 100th day of life) only 2 animals of the high dose group were observed with bilateral testicular atrophy. Despite of the two animals with testicular atrophy no significant differences between treated and control rats were observed with respect to testis morphology and spermatogenesis. There is no evidence whether the differences between the hormone levels and the testicular atrophy revealed is regarded to a HS 1500-effect or not. But otherwise a direct influence of HS 1500 can be ruled out with high certainty. Possibly because of the thin covering layer on the gastrointestinal mucous membrane formed by HS 1500, the absorption of nutritive substances is inhibited. Therefore the growth of sensitive organs like testis and epididymis, in the development period, can be decreased. Nevertheless, even after long time application the spermatogenesis is not influenced.

[Fetal reflectance pulse oximetry sub partu. Experiences--prognostic significance and consequences--goals]

Reflectance pulse oximetry is a new method to monitor the fetus during labour in order to get a better assessment of the fetus's condition than by CTG interpretation alone. In this study the method is investigated with regard to its prognostic value concerning fetal outcome and complications possibly due to its application: Increased uterine bleeding, umbilical cord complications, amniotic infection syndrome. Arterial oxygen saturation was continuously recorded during labour in a total of 122 patients with a gestational age between 37 and 42 weeks and correlated to the umbilical cord-pH post partum and, if available, to intrapartum fetal blood gas analysis. 30% seems to be a threshold value below which oxygen saturation should not drop for a longer period of time. A post partum pH < 7.2 can be expected in more than 50% of the cases in which the saturation remains below this value for more than ten minutes. The application of the fetal pulse oximeter sensor did not affect maternal or fetal morbidity.

[Cytokines in the diagnosis of amniotic infection syndrome]

Accumulating evidence indicates an association between intraamniotic infection and raising concentrations of amniotic cytokines, resulting in preterm labor and preterm rupture of fetal membranes, because these cytokines are able to stimulate prostaglandin biosynthesis. Therefore the purpose of our study was to investigate if quantitative determination of Il-1 beta, Il-6, Il-8 and TNF-a in amniotic fluid may be a practicable method to diagnose intraamniotic infection. Since invasive amniocentesis doesn't allow repeated cytokine detection, in case of preterm rupture of fetal membranes, amniotic fluid also was obtained by placing a sterile gauze and cotton pad into the women's vagina, absorbing draining amniotic fluid for cytokine detection. Our results clearly indicate that Il-1 beta and TNF-a are not detectable in normal pregnancy, while Il-6 and Il-8 are produced in low, but constant levels. In contrast, in amniotic fluid of patients with intraamniotic infection high amounts of Il-6 and Il-8 were found, while Il-1 beta and TNF-a bioactivity became measurable, indicating that biosynthesis was activated. These results demonstrate, that infection associated cytokines detectable in amniotic fluid are highly sensitive markers for intraamniotic infection. In case of preterm rupture of fetal membranes recovery of amniotic fluid from a vaginal pad allows monitoring of cytokine bioactivity in daily intervals to control success of antibiotic treatment.

[Congenital candida infections]

Congenital candida infection is a rare disease, although the incidence of candida vaginitis during pregnancy is high. We report on five cases each showing patterns considered typical for candida infection. The infective agent can cause chorioamnionitis even in the presence of intact fetal membranes. An intrauterine device (IUD) has been proved to be a risk factor for a congenital candida infection. The pathogenetic significance of contamination with candida for the fetus appears to depend largely on gestational age. A premature infant with a birth-weight less than 1500 g presented with bilateral candida endophthalmitis which was cured by intravenous Fluconazole therapy. Another premature infant weighing 800 g at birth developed a systemic candida infection. The other three more mature infants had milder symptoms, two of them presented with cutaneous candidiasis.

[The use of the HET-CAM test for the determination of the irritating effects of humic acids]

Using the synthetic humic acid product HS 1500 and the native product Sodium-Humate, the suitability of the HET-CAM-test to evaluate irritating effects was tested. Neither sensitizing nor irritating properties were detectable in concentrations of up to 10% in either humic acid solution. This leads us to the conclusion that both products are very mildly acting substances on mucous membranes and skin, causing no irritative effects. In order to improve the certainty of these results, it is still currently recommended to carry out the Draize-test in addition to the HET-CAM procedure (SPIELMANN, 1992). We are convinced that the HET-CAM-test can be a very useful first step in distinguishing between irritative and non irritative substances and in protecting animals from pain, even in the event that the results of both tests do not clearly correspond to each other. Taking into account the results of our experiments, a modified HET-CAM-test also seems to be useful to predict the antiphlogistic effects of chemical substances.

[The effect of ecotoxicological processes on animal husbandry in industrial countries]

This paper describes results of ecotoxicological investigations concerning the effects of industrial pollutants on farm animals. By means of simultaneous experiments using dusts from lignite-filters and sedimentation-filters as well as sulfur dioxide (SO2) as stress models and by using studies on farm animals in pollutant-burden regions of eastern Germany it could be shown, that pollutants can lead to disorders of health, efficiency and behaviour, like o. g. heavy metals, and to contamination of food of animal origin. Dusts, resulting from combustion of lignite and SO2 initiate non specific effects in the organism and it is only difficult to determine their part on the decrease of productivity and metabolic disorder of farm animals in pollutant regions.

[The hexobarbital sleeping time in a pharmacologico-toxicological experiment with special reference to age and chronobiologically-limited variations in Wistar rat strain WIST/Lppt]

Investigations were performed to determine the hexobarbital sleeping time (HST) of a strain of Wistar rats (WIST/Lppt). Another aim of the studies was to demonstrate possibilities to use the HST as a method to get additional informations during pharmacological and toxicological experiments. The age--and sex--dependent changes in the hexobarbital sleeping time of the investigated strain of rats are in coincidence with results of other authors, using different rat strains. Additionally, the HST more or less depends on circadian and circannual rhythm. It was stated that the HST as a prescreening-method before starting investigations in detail is of great importance.

[The tolerance and residue accumulation of sodium-2,2-dichloropropionate (Dalapon) administered over 90 days to dairy cows]

The influence of the pesticide Sodium-2,2-dichlorpropionate (Na-DCP; Dalapon) was investigated on dairy cows concerning of its effect on ability and health condition. The investigations were carried out in practice using several parameters (feeding, efficiency, haematological and clinicochemical parameters, tests of the slaughtered organisms including their patho-histological examination). The arising of residues was controlled in milk, organs and tissue as well. The pesticide was daily applied orally with the feedstuff in 3 different dosages (2.5, 10, 30 mg/kg b. w./d). Feedstuff consumption, results of milk production and milk quality were not influenced by Na-DCP. The presented results can not verify with safety the insignificant alterations of some clinicochemical parameters (Creatinine, Bilirubin). Direct after the deposit of Dalapon in all samples of milk, organs and tissue residues of this pesticide could be observed. The maximum tolerable residue levels for animal in the ex-GDR were exceeded under these conditions.

[The enteral absorption of iron (II) from humic acid-iron complexes in suckling piglets using radiolabeled iron (59Fe)]

Bioavailability of iron (II) bounded as a chelate to macromolecular humic acids was investigated in two different concentrations using retention rates of 59Fe in piglets (age: 24 h). Investigations period was from 3 hrs. to 21 days following application. 21 days after a single oral application of the humic-acid-iron-complexes, 25% of the total Fe was detected in the animal, distributed in the erythrocytes (80%), muscles and bones (8% respectively) and liver (4%). For the first time in veterinary medicine these results enable a combined therapy of enteric and iron-deficiency syndrome by using only one drug. Recommendation for dosing is provided.