Ni-base superalloy single crystal (SX) mosaicity characterized by the Rotation Vector Base Line Electron Back Scatter Diffraction (RVB-EBSD) method

In the present work we present the Rotation Vector Base Line Electron Back Scatter Diffraction (RVB-EBSD) method, a new correlative orientation imaging method for scanning electron microscopy (OIM/SEM). The RVB-EBSD method was developed to study crystal mosaicity in as-cast Ni-base superalloy single crystals (SX). The technique allows to quantify small crystallographic deviation angles between individual dendrites and to interpret associated accommodation processes in terms of geometrically necessary dislocations (GNDs). The RVB-EBSD method was inspired by previous seminal approaches which use cross correlation EBSD procedures. It applies Gaussian band pass filtering to improve the quality of more than 500 000 experimental patterns. A rotation vector approximation and a correction procedure, which relies on a base line function, are used. The method moreover features a novel way of intuitive color coding which allows to easily appreciate essential features of crystal mosaicity. The present work describes the key elements of the method and shows examples which demonstrate its potential.

Bioactivity and electrochemical behavior of hydroxyapatite-silicon-multi walled carbon nano-tubes composite coatings synthesized by EPD on NiTi alloys in simulated body fluid

In order to improve the surface bioactivity of NiTi bone implant and corrosion resistance, hydroxyapatite coating with addition of 20wt% silicon, 1wt% multi walled carbon nano-tubes and both of them were deposited on a NiTi substrate using a cathodic electrophoretic method. The apatite formation ability was estimated using immersion test in the simulated body fluid for 10days. The SEM images of the surface of coatings after immersion in simulated body fluid show that the presence of silicon in the hydroxyapatite coatings accelerates in vitro growth of apatite layer on the coatings. The Open-circuit potential and electrochemical impedance spectroscopy were measured to evaluate the electrochemical behavior of the coatings in the simulated body fluid at 37°C. The results indicate that the compact structure of hydroxyapatite-20wt% silicon and hydroxyapatite-20wt% silicon-1wt% multi walled carbon nano-tubes coatings could efficiently increase the corrosion resistance of NiTi substrate.

Polyethylene wear particles induce TLR 2 upregulation in the synovial layer of mice

A cellular and receptor mediated response to ultra-high-molecular-weight-polyethylene (UHMWPE) wear particles results in a release of proinflammatory cytokines and induces an inflammatory reaction causing osteolysis in total joint replacement. This investigation offers insight into the toll-like receptor (TLR) mediated activation by polyethylene wear particles in the synovial layer of mice. We hypothesized that, similar to recent in vitro results, UHMWPE particles lead to an upregulation of TLR 1 and 2 and TLR 4 in vivo in the synovial tissue of mice as well. Therefore, UHMWPE particles were generated in a common knee simulator according to the ISO standard, separated by acid digestion and determined by scanning electron microscopy. Endotoxin was removed using a method based on ultracentrifugation. A particle suspension (50 μl; 0.1 vol./vol.%) was injected into the left knee joint of female Balb/c mice (n = 8). In a control group, phosphate-buffered saline was injected into the left knee of Balb/c mice (n = 8). The mice were sacrificed after 7 days. Immunohistochemical staining was performed with TLR 1, 2 and 4 polyclonal antibodies for Balb/c mice and evaluated by light microscopy. The particle-stimulated group showed a thickened synovial layer, an increased cellular infiltration and a TLR 2-upregulation in the synovial layer compared to the control group. An increased expression of TLR 1 and TLR 4 could not be demonstrated. These results indicate a mainly TLR 2-induced inflammation to polyethylene wear debris in the synovial layer of mice.

[Postoperative pain management after minimally invasive hysterectomy: thoracic epidural analgesia versus intravenous patient-controlled analgesia]

BACKGROUND

In view of the development of innovative and non-traumatic surgical techniques, postoperative pain management should be carried out depending on the invasiveness of the intervention. In the present study two analgesic strategies were compared in patients undergoing minimally invasive hysterectomy: epidural analgesia (EDA) and intravenous patient-controlled analgesia (iv-PCA).

MATERIAL AND METHODS

For this prospective case controlled study 60 women with benign uterine diseases undergoing vaginal hysterectomy (VH) or laparoscopically assisted vaginal hysterectomy (LAVH) were enrolled. Patients were divided for analysis into two groups (n=30 each) according to the postoperative analgesic strategy (EDA group versus iv-PCA group). A matched-pair analysis was applied (matching criteria: risk assessment, surgeon and age of patient) to minimize the differences between both groups. Patients were evaluated with respect to the extent of pain determined by a numeric rating scale (NRS 0-10 scale), analgesic consumption, rate of postoperative nausea and vomiting (PONV), mobilization from bed, oral intake of nutrition, complications, duration of stay in the recovery room as well as hospital stay and health-related quality of life (SF-36 Health Survey; collected before and 6 weeks after surgery).

RESULTS

Laparoscopically assisted removal of the uterus was carried out in 22 women and by vaginal hysterectomy in 38 women. No significant differences between the study groups were seen in the duration of surgery (iv-PCA 58 ± 25 min versus EDA 60 ± 26 min). Demographic data of both groups as well as intraoperative hemodynamic and respiratory parameters were comparable to a great extent. Compared to the iv-PCA group, women in the EDA group showed lower NRS values (p<0.01): recovery room admission 4.7 ± 2.5 iv-PCA vs. 0.9 ± 1.3 EDA, recovery room discharge 3.8 ± 1.8 iv-PCA vs. 1.0 ± 1.2 EDA, day of surgery at 8 p.m. 5.0 ± 2.1 iv-PCA vs. 1.8 ± 2.3 EDA and first postoperative day at 8 a.m. 3.5 ± 1.7 iv-PCA vs. 1.9 ± 2.2 EDA. In addition, less PONV (iv-PCA 9/30 vs. EDA 1/30, p<0.01), less shivering (iv-PCA 8/30 vs. EDA 2/30, p<0.05), reduced fatigue (iv-PCA 26/30 vs. EDA 9/30, p<0.05) and a lower consumption of analgesics were found. Average postoperative requirement for piritramide in the iv-PCA group was 7 mg (range 0-24 mg) on the day of surgery and 5 mg (0-39 mg) on the first postoperative day. In the EDA group no opiate medication was given postoperatively (p<0.01). Duration of stay in the recovery room was shorter in the EDA group (71 ± 32 min vs. 50 ± 13 min, p<0.05). Hospital stay was 5 days on average in both groups. There were no surgical complications or epidural catheter-related complications. Because of urinary retention catheterization of the bladder had to be made in 3 patients of the iv-PCA group and 13 patients of the EDA group (p<0.05). Furthermore, the possibility to take a shower postoperatively was restricted in the EDA group because the epidural catheter was in place and thereby hygiene concerns. Regarding the early oral nutritional intake as well as postoperative mobilization, no significant differences between groups were found. In comparison with the preoperative status, the results regarding health-related quality of life were significantly better for both groups after a follow-up of 6 weeks (p<0.01); however, this effect was especially pronounced in the EDA group (p<0.05).

CONCLUSIONS

To reduce the number of patients suffering from postoperative pain a procedure-specific pain management should be developed. The results of this study have shown that even in minimally invasive surgery, such as vaginal hysterectomy and laparoscopically assisted vaginal hysterectomy there are some advantages for epidural analgesia compared to intravenous patient-controlled analgesia. In particular reduced pain intensity, lower need for analgesics and reduced occurrence of PONV can lead to excellent patient comfort, fast recovery as well as positive effects on health-related quality of life. However, there are also some disadvantages such as an increased rate of urinary retention and restriction of mobility.

The biocompatibility of dense and porous Nickel-Titanium produced by selective laser melting

Nickel-Titanium shape memory alloys (NiTi-SMA) are of biomedical interest due to their unusual range of pure elastic deformability and their elastic modulus, which is closer to that of bone than any other metallic or ceramic material. Newly developed porous NiTi, produced by Selective Laser Melting (SLM), is currently under investigation as a potential carrier material for human mesenchymal stem cells (hMSC). SLM enables the production of highly complex and tailor-made implants for patients on the basis of CT data. Such implants could be used for the reconstruction of the skull, face, or pelvis. hMSC are a promising cell type for regenerative medicine and tissue engineering due to their ability to support the regeneration of critical size bone defects. Loading porous SLM-NiTi implants with autologous hMSC may enhance bone growth and healing for critical bone defects. The purpose of this study was to assess whether porous SLM-NiTi is a suitable carrier for hMSC. Specimens of varying porosity and surface structure were fabricated via SLM. hMSC were cultured for 8 days on NiTi specimens, and cell viability was analyzed using two-color fluorescence staining. Viable cells were detected on all specimens after 8 days of cell culture. Cell morphology and surface topography were analyzed by scanning electron microscopy (SEM). Cell morphology and surface topology were dependent on the orientation of the specimens during SLM production. The Nickel ion release can be reduced significantly by aligned laser processing conditions. The presented results clearly attest that both dense SLM-NiTi and porous SLM-NiTi are suitable carriers for hMSC. Nevertheless, before carrying out in vivo studies, some work on optimization of the manufacturing process and post-processing is required.

Do cement nanotubes exist?

Using atomistic simulations, this work indicates that cement nanotubes can exist. The chemically compatible nanotubes are constructed from the two main minerals in ordinary Portland cement pastes, namely calcium hydroxide and a calcium silicate hydrate called tobermorite. These results show that such nanotubes are stable and have outstanding mechanical properties, unique characteristics that make them ideally suitable for nanoscale reinforcements of cements.

Functional interactions within the newborn brain investigated by adaptive coherence analysis of EEG

To assess functional cortical organization in newborns during quiet sleep we investigated instantaneous interhemispheric coherences in six healthy full-term subjects using linked ear reference and average reference. Tracé alternant was the most frequent EEG pattern during quiet sleep of these newborns and consists of burst and interburst periods. The calculation of coherence was performed by means of time-variant autoregressive models on the basis of Kalman filtering. Coherence changes simultaneously with the appearance of these burst and interburst periods. The highest level of coherence was observed during burst periods in comparison with interburst periods. The lowest level of coherence was observed just before the burst started. During burst, maximal coherence was reached at different moments--late in the low frequency band (0.5-1.5 Hz; about 3 s after the burst started) and earlier in higher frequency bands (> 2 Hz, about 2 s). Interhemispheric coherence depended on the region being investigated. A significant level of coherence could be observed over frontal, temporal and occipital regions. Our data demonstrate significant modification of interhemispheric coherence during quiet sleep of full-term newborns and, irrespective of the immaturity of the brain, these coherences differ significantly between cortical regions.

Spectral analysis of electroencephalogram during sleep-related apneas in pre-term and term born infants in the first weeks of life

OBJECTIVES

A correlation between sudden infant death syndrome (SIDS) and apnea has been discussed in a variety of studies. We analyzed polysomnographic data in 51 infants and investigated correlations between the manifestation of apneas and changes in EEG pattern.

METHODS

Measurements were performed by means of the commercial polysomnographic device 'ALICE III'. Spectral analysis of certain parts of the registered EEG was performed.

RESULTS

During apnea a reduction of the EEG amplitude was seen. The extent of the decrease differed slightly between the frequency bands.

CONCLUSIONS

According to the widespread agreement that a lower voltage of electrical brain activity is a fundamental sign of waking up, we hypothesize that the observed change might be an immature type of arousal reaction.

Brain dysmaturity index for automatic detection of high-risk infants

The definition of an electroencephalographic (EEG)-based brain dysmaturity index that could allow automatic detection of neonates who deviate from expected ontogenetic patterns is proposed. The investigation was performed in a group of 94 term and preterm infants (28-112 weeks postconceptional age). For each neonate, one continuous two-channel EEG of 1-6 hours was recorded. The cluster analysis of different age groups was performed with a self-referential neural network. The network performed a nonlinear discriminant analysis; the synaptic strength of input nodes indicates the relevance of an individual EEG feature. The most relevant EEG features are given by the average amplitude in the delta and theta bands and by the relative amplitudes of beta-1/theta and beta-1/delta, respectively. The correlation between the frequency shifts and the postconceptional age agreed with measures of brain dysmaturity in healthy preterm neonates. Thus the presented trend in early EEG development demonstrates that it is possible to establish clinically relevant age dysmaturity scores.

[Doppler ultrasound monitoring of cerebral circulation during neonatal intensive care with special reference to artificial respiration]

BACKGROUND

Doppler sonographic data from routine cerebral ultrasonic examination of mechanically ventilated premature neonates were analyzed in order to find out which intensive care influence factors take effect on the cerebral circulation. It was to be demonstrated if Doppler sonographic results are changed by current intensive medical influences especially mechanically ventilation.

PATIENTS AND METHODS

In 24 premature neonates (mean gestational age 29.6 +/- 4 weeks, mean birth weight 1367 +/- 660 g) treated with mechanical ventilation for IRDS cerebral blood flow parameters were assessed by pulsed Doppler sonography. A single Doppler sonographic investigation was performed during the first week of life (median: day 5). Doppler flow velocity waveforms were obtained, and resistance index (RI) and pulsatility index (PI) values were calculated from the anterior cerebral arteries (ACA) as well as from the internal carotid artery (ACI). Oscillometrically measured blood pressure, pH, pCO2, and parameters of mechanical ventilation were registered.

RESULTS

Besides the well established influence of pCO2 and blood pressure parameters of mechanical ventilation PEEP and time of inspiration have an influence on cerebral blood flow.

CONCLUSIONS

Our results demonstrate the impact of mechanical ventilation on cerebral blood flow and therefore indicate the necessity of Doppler sonographic monitoring during mechanical ventilation. To our knowledge this is the first report about the influence of mechanical ventilation on cerebral blood flow in neonates.

Clinical relevance of age-dependent EEG signatures in the detection of neonates at high risk for apnea

Age dependent EEG signatures were detected in the EEG of 71 neonates of 28-100 weeks of conceptional age (CA). Using the new method presented, neonates were automatically classified in three age groups (28-35 weeks CA), (36-40 weeks CA) and (41-100 weeks CA). Analysis was performed employing relative distance functions for the complete frequency spectra of the EEG registered by electrodes in C3 and C4 positions. The analysis was successful in automatic identification of individuals showing EEG anomalies. Polysomnographic analysis demonstrated these to be apnea risk patients. Accordingly, a purely EEG based detection of neonates that are medically at risk becomes feasible.

[Monitoring kidney function during neonatal intensive care: comparison between Doppler ultrasound findings and renal function parameters]

33 neonates between 4th and 7th day of life were enrolled in the study. The data of renal Doppler sonography were compared to renal excretion parameters. In infants with respiratory distress a decrease of creatinine clearance as well as an increase of fractional sodium excretion were associated with reduced peak systolic flow velocity in the A. renalis. The results suggest the importance of the Doppler sonography in the monitoring of the renal function in the newborn intensive care.

Fructose 2,6-bisphosphate induces irreversible transitions in cell-free extracts of rat liver

The effect of fructose 2,6-bisphosphate on the dynamics of the 6-phosphofructo-1-kinase/fructose-1,6-bisphosphatase cycle is investigated in a cell-free extract of rat liver under steady-state conditions. Bistability emerges on the basis of the reciprocal allosteric modulation of 6-phosphofructo-1-kinase and fructose-1,6-bisphosphatase. Under conditions of bistability fructose 2,6-bisphosphate may cause transitions between alternative steady states. However, in contrast to what is frequently observed in bistable systems, within a broad range of experimental conditions these transitions proceed irreversibly from states with high ATP to states characterized by low ATP.

Bistability and damped oscillations in the fructose 6-phosphate/fructose 1,6-bisphosphate cycle in cell-free extracts from rat liver

The dynamics of the fructose 6-phosphate/fructose 1,6-bisphosphate substrate cycle was investigated in cell-free extracts from rat liver. Under conditions of continuous substrate supply different types of stationary states and damped oscillations were observed experimentally and found to be in qualitative agreement with theoretical predictions. Changing the adenylate energy charge of the substrate supply, bistability was shown to be related to irreversible transitions between functionally different branches of stable stationary states.

Penile sympathic skin response in erectile dysfunction

Penile sympathic skin response (PSSR) was measured in 20 normal patients and in 46 patients with erectile dysfunction (ED). PSSR could be registered in 80% of normal patients. The latencies were 1,100-1,600 ms. In patients with ED, latencies were 1,240-3,640 ms. A reproducible normal latency of PSSR (< 1,600 ms) indicates a normal sympathic innervation of the penis. Long latencies (> 1,800 ms) indicate neuropathy of unmyelinated nerval fibers. The loss of a reproducible answer however allows no exact diagnostic information. PSSR is a useful diagnostic test for detecting neuropathy of unmyelinated nerval fibers as a possible cause of ED.

[School performance of former premature infants in the first four years of school]

School achievement during the first four grades was analysed by means of subject marks in 203 prematurely born and in 140 maturely born children. In subjects referring to behaviour in the classroom, no statistically significant differences in average marks could be found between prematurely born children and the control group. The average marks in performance subjects were slightly higher in the subgroup of very prematurely born children. However, statistically significant lower marks were observed in the subject of sports only, and for formerly immature children also in the subject of manual training. The higher the educational level of the mothers, the better the average marks without sports. No relationships between school performance and manifestation of postnatal risk factor like Apgar score, blood gas values and duration of oxygen dependency could be seen. These results demonstrate that school performance of former premature infants lies within the normal variance of their grade.

[The renal effects of dopamine therapy in premature infants in the first week of life]

It is known that Dopamine therapy induces loss of water and sodium on the first or second days of life. On the other hand, no studies have been published on renal function under long-term therapy. In our study we could prove an altered excretion of water and sodium as well as fractional sodium excretion in preterm infants who received dopamine for at least the first week of life. Conclusions for clinical practice are drawn.

[Diagnostic possibilities and limits of 4-electrode rheoencephalography in premature infants with risk of brain damage]

Diagnostic value of cerebral electrical impedance for recognizing the risk of cerebral damage was analysed in 63 premature infants with postnatal respiratory disturbance during the first 4 weeks of life. Relationship between clinical risk factors like gestational age, Apgar scores, blood gas values on the one hand and impedance parameter of pulse volume, flow velocity and periphereal vascular resistance on the other were studied by means of correlation as well as variance analysis. Decrease of gestational age, Apgar score and increasing severity of respiratory disturbance cause statistically significant lowering of impedance parameters indicating reduction of volume, flow velocity and periphereal resistance in cerebral circulation by extreme immaturity, serious asphyxia as well as idiopathic respiratory distress syndrome. On contrast no statistically significant difference could be found between infants with and without intraventricular haemorrhages. However, significant differences were seen between group of patients only. Because of intercorrelation of risk factors and distinct variance no critical level of impedance parameters could be defined for the individual patient.

[Studies on the predictive value and prognostic significance of compliance measurements in artificially ventilated newborn infants]

In 29 mechanical ventilated preterm infants the compliance of the respiratory system (Crs) was determined. Newborn infants with severe respiratory distress syndrome show a decreased Crs. A significant correlation could be proved between the Crs and the pCO2 as well as the inspiratory pressure. The second estimation of the Crs after 48 hours refers to the prognosis of the ventilated newborn infants.

[Prognostic value of Doppler ultrasound blood flow measurements in the anterior cerebral artery of premature infants]

The relationships between doppler-sonographic determination of systolic, diastolic flow velocity and pulsation index in the A. cerebri anterior and developmental outcome at 12 month of age were studied by means of multivariate variance and discriminance analysis. The study involves 92 preterm infants, in whom flow measurement were performed in the first 3 days and the second week of life. The influence of additional perinatal risk factors like Apgar score, blood gas values and type of intensive care were taken in consideration: Doppler-sonographic flow parameters were found to be necessary coefficients of statistically significant discriminant functions, which differentiate between infants with normal or delayed psycho-motoric development or cerebral palsy. However, in comparison to the other risk factors their weight for differentiation is low. Parameters of immediate postnatal adaptation like apgar score and blood gas values decide quality of developmental outcome in infants with as well as without ultrasonographically proven neonatal brain damage. In infants with neonatal ventricular hemorrhages only a distinct influence of immaturity was observed additionally.

Regulation of the fructose 6-phosphate/fructose 2,6-bisphosphate cycle by enzyme phosphorylation and sn-glycerol 3-phosphate

The regulation of the Fru-6-P/Fru-2,6-P2 cycle by the cooperation of allosteric and covalent mechanisms was investigated in a reconstituted enzyme system under in vitro conditions. Phosphorylation of the bifunctional enzyme exerts a much stronger effect than sn-glycerol 3-phosphate in lowering the quasi-stationary concentration of fructose 2,6-bisphosphate and in increasing the critical concentration of the fructose phosphates, respectively. However, sn-glycerol 3-phosphate is able to strongly amplify the decrease of the quasi-stationary concentration of fructose 2,6-bisphosphate due to phosphorylation. The experiments can be described by a mathematical model involving rate equations for the dephosphorylated and the phosphorylated PFD-2 and FBPase-2. The results are compared with data from the literature obtained under in vivo conditions.

[Sonographic diagnosis of gastroesophageal reflux in infancy]

The gastroesophageal reflux is a common problem in the pediatric clinical practice in the 1st year of life. Its diagnosis is mainly based on the x-ray and the measurement of the esophageal pH. Our investigation shows the possibility of the ultrasonographical diagnosis of this disturbance. We could demonstrate a good correlation between the x-ray and the ultrasonographical findings. A continuous lasting gastroesophageal reflux which takes more than 5 minutes points to a pathologic reflux pattern with the well known complications. Thus, ultrasonographical investigation should perform before an extensive diagnostic is taken into consideration.

Differentiation of healthy newborns and newborns-at-risk by spectral analysis of heart rate fluctuations and respiratory movements

Neonatal heart rate and its interaction with respiration were computerized by spectral and coherence analysis (FFT) to differentiate healthy newborns (n = 9) from newborns with mild neonatal risk (n = 20). An increased mean heart rate and decreased total variability have been found in newborns-at-risk. Respiratory Sinus Arrhythmia is diminished in newborns-at-risk possibly caused by an impairment of autonomic brain stem function. Furthermore, Respiratory Sinus Arrhythmia holds a central position in differentiating healthy newborns and newborns-at-risk with and without neurological abnormalities during the first year of life. Respiratory Sinus Arrhythmia is diminished in newborns-at-risk showing these abnormalities. None of the parameters discriminates between the two groups of risk infants. The final prognostic value of our results must be confirmed in further clinical follow-up examinations.

[Significance of trial vacuum extraction in the framework of obstetric surgery in vertex presentation]

On the basis of a clinical study of 76 infants born by trial vacuum extraction from the pelvic inlet, 57 infants were examined retrospectively with regard to early and late morbidity after "successful" trial vacuum extraction. In 34 cases surgery was indicated because of fetal distress; in 23 children the operation was performed because of a standstill at the pelvic inlet. The results were compared with a group of infants delivered by vacuum and forceps extraction from the centre of the pelvis (or the pelvic floor) or cesarean section in consequence of fetal distress. The results indicate the high risk for children born by trial vacuum extraction, especially in cases of fetal distress. In addition to statistically significant lower Apgar scores and a statistically significant higher acidosis morbidity (p less than 0.05) as compared to other obstetric operations, there is also a statistically significant greater number of "striking" and "injured" children as opposed to those delivered by vacuum or forceps extraction from the centre of the pelvis (or the pelvic floor) or by cesarean section in consequence of fetal distress. These neurological deviations represent primarily the static-motoric and speech development, and are analogous to late morbidity after births from breech presentation. The findings confirm the clinical impression that trial vacuum extraction-especially in cases of fetal distress at the pelvic inlet-represent an additional risk to the child. In such cases cesarean section is the only alternative method of delivery.

[Early and late morbidity of underweight (LBW) newborn infants following breech presentation in relation to the mode of delivery]

The influence of type of delivery on neonatal mortality, frequency of disturbances in adaptation to extrauterine life, and incidence of deviations in psychomotoric development was examined retrospectively in 126 low birthweight infants born in breech presentation. 65 infants were born by cesarean section, 61 by vaginal delivery. The control group involves 270 low birthweight infants born spontaneously in vertex presentation. In the weight categories of 1500 to 2500 g neonatal mortality, frequency of pathologic Apgar-scores, acidosis morbidity, incidence of severe respiratory distress, and percentage of psychomotoric handicaps were found to be lower in infants born by cesarean section compared to vaginally born newborns. However, only some of the differences between both groups were statistically significant. In newborn infants weighing less than 1500 g at birth an improved outcome after abdominal delivery could not be demonstrated.

[Factor VIII activity and factor VIII-associated antigen in healthy newborns and in newborns with stressing perinatal factors]

Factor VIII coagulation activity (VIII:C) and factor VIII associated antigen (VIII:AGN) were determined in healthy newborns and in children with charging perinatal factors ("risk children"). VIII:C values of healthy newborns may be compared with those of grown-ups with normal coagulation. Risk children have somewhat higher values than newborns, the difference, however, being statistically not significant. The concentration of VIII:AGN is clearly increased in both groups on the first day of life. Moreover, VIII:AGN is being eliminated more slowly in risk children. The increased VIII:AGN concentrations are considered as a sequel of stress conditions caused by birth, whereas the discrepancy between VIII:C and VIII:AGN is due to a thrombin effect.

[Morbidity studies, following continuous electronic and biochemical monitoring of 1,000 childbirths (author's transl)]

A group of 1,000 electronically and biochemically monitored children of high-risk deliveries was examined for morbidity up to the age of one year.--Transfer to the Paediatric Hospital of Jena University had been necessary for 147 newborns for low weight and/or impaired adaptation. Sixteen of 18 neurologically conspicuous children, which had temporarily displayed electro-encephalographic or echo-encephalographic pathological or marginal findings, did no longer exhibit any neurological deficiency or signs of impaired intelligence, when re-examined after ten months. Only two children had severe disorders in terms of infantile cerebral paresis, one of them with a genetically determined disease (Morbus Langdon Down).--Incidence of infantile cerebral paresis dropped from more than three to something between one and two per cent owing the antepartum, intrapartum, and postpartum intensive monitoring as well as to intensive neonatal care. It is assumed that this will act to decrease the number of children with mental retardation.

Factor VIII activity and factor VIII related antigen in newborns

Factor VIII procoagulant activity and factor VIII related antigen were examined in 20 full-term and preterm newborn infants during the first days of life. The control group involved 15 adults volunteers. Factor VIII activity was estimated by a one-stage test and factor VIII related antigen was determined by immunelectrophoresis according to Laurell, using our own rabbit antiserum. The following results were obtained:--Factor VIII activity during the first 3 days of life did not differ from the normal range of the adult controls.--The concentration of factor VIII related antigen in newborns was markedly higher than in adults on the first, and to a lesser extent on the second, day of life.--The antigen concentration decreases on the second and following days of life to adult levels. The cause of this discrepancy cannot be completely explained but possible reasons are discussed.

Calorimetric, 13C NMR, and 31P NMR studies on the interaction of some phenothiazine derivatives with dipalmitoyl phosphatidylcholine model membranes

1. The dipalmitoyl phosphatidylcholine/water system was employed to study the interaction of phenothiazines with model membranes. In particular the effects of the drugs upon the lipid phase transition were examined using differential scanning calorimetry and NMR spectroscopy. The studied phenothiazines have peripheral (diethazine) or central (chlorpromazine) properties. 2. Both drugs were observed to lower the phase transition temperature of dipalmitoyl phosphatidylcholine. The molar activity of chlorpromazine is somewhat higher than of diethazine. At low concentrations the drugs affect the dipalmitoyl phosphatidylcholine pretransition endotherm. 3. In the 13C NMR spectra of the drug-containing samples the signal of the trimethylammonium group of dipalmitoyl phosphatidylcholine is broadened, whereas a narrowing of the signal of the fatty-acid chain methylene groups is observed. Further, addition of the phenothiazines causes higher values of the effective chemical shift anisotropy of the 31P in the phosphate group, in comparison to the pure dipalmitoyl phosphatidylcholine sample. 4. The results obtained by three different techniques indicate a higher fluidity in the fatty-acid chain region and a mobility reduction of the polar headgroup of the dipalmitoyl phosphatidylcholine molecules in the presence of the phenothiazines. These phenomena can be well accounted for by a model for the incorporation of the phenothiazines in the dipalmitoyl phosphatidyl-choline bilayer, in which the dialkylaminoalkyl chains are located near the polar headgroups and the ring system does not penetrate far beyond the glycerol backbone into the hydrocarbon phase.