In vitro measurement of flow rate variability in neonatal IV therapy with and without the use of check valves.

BACKGROUND: In multi-infusion IV therapy, the actual volume delivered to the neonate can vary over time. To reduce flow rate variability, check valves can be used. A check valve allows flow through the valve in only one direction. OBJECTIVE: To evaluate flow rate variability in a low flow dual-infusion setup with and without check valves. METHODS: The effect of changing the height of and adding syringes to the IV-administration set was tested with and without check valves in an in vitro dual-infusion setup with in-line flow meters. The pre-programmed flow rates were 2.5 and 0.1 ml/h. RESULTS: Twenty-four tests of 90 minutes were performed. Time to reach 75% of the pre-programmed 0.1 ml/h flow rate was >20 minutes. The highest total delivered volume during a test was (mean ± SD) 56 ± 8% of the expected delivery for tests without check valves, and diminished to 12 ± 24% of the expected delivery for check valves with a higher opening pressure. CONCLUSIONS: The actual flows and the total delivered volume in low flow dual-infusion setups are less than expected on the pre-programmed flow-rate. These findings emphasize the need for the development of more accurate delivery systems for drugs and fluids in neonatology. Caregivers should be aware of these findings, and optimise the delivery of IV substances by making use of check valves with low opening pressures and by minimising compliance and volume of the IV-administration set. Furthermore, changes in the relative height between pumps and catheter tip should be minimized.

An improved, disposable indwelling intrauterine tube ("smit sleeve") not requiring retaining stitches for brachy-radiotherapy for carcinoma of the cervix.

OBJECTIVE: The objective was to improve the design of the indwelling-intrauterine tube (IIUT) for brachy-radiotherapy of cervical cancer or sleeve, specifically one that would not require stitching to retain it properly in the uterus for periods of one to two weeks and to ensure hygiene by making them disposable, thinner, lighter, more economical, as well as more user-friendly for doctor and patient alike, and to satisfy new developments in terms of computed tomography (CT) and magnetic resonance imaging (MRI) compatibility. MATERIALS AND METHODS: Injection moulding of carefully-selected medical grade polymers enabled ten improvements to the original sleeve; some were impossible to achieve with lathe turned items. The most important innovation was the addition of two delicate and very soft "wings" to the sleeves near the tips The sleeves were used in 50 consecutive patients with advanced carcinoma of the cervix. Metal markers could be eliminated by adding barium to the polymers. RESULTS: Not a single sleeve fell out in any of the 50 patients. No complications related to the use of the sleeves were observed. These sleeves are now used exclusively in this clinic. CONCLUSIONS: The improvements were very successful; none fell out and no suturing was required, which made them still more cost-effective and more comfortable to patients.

Outcome of pregnancies complicated by oligohydramnios or anhydramnios of renal origin.

OBJECTIVE: To evaluate the outcome of fetuses with oligohydramnios due to kidney anomalies. METHODS: A retrospective study was performed of all pregnancies diagnosed with oligohydramnios and associated kidney anomalies during the period 2000-2008. Outcome included pregnancy outcome, mortality, and morbidity. Morbidity included renal function based on the glomerular filtration rate (GFR) during follow-up. RESULTS: A total of 71 pregnancies were evaluated; 36 fetuses presented on ultrasound with cystic dysplasia, 15 with polycystic kidney disease (PKD) and 20 with hydronephrosis. Twenty-three (32%) had associated anomalies. In 49 fetuses (69%), the diagnosis had been made before 24 weeks of gestational age (GA); 41 of those pregnancies were terminated. Twenty-five neonates were live born: 10 survived, 15 died. Prognostic factors for survival included GA at diagnosis (32.2 weeks for survivors vs 28.1 weeks for non-survivors; P = 0.02), diagnosis of hydronephrosis (7 in the survivors vs 4 in the non-survivors: P = 0.05), isolated anomaly (9 in the survivors vs 7 in the non-survivors: P = 0.04). Severity of oligohydramnios (1 case of anhydramnios in the survivors vs 7 in the non-survivors: P = 0.08) was not significant. The 1-year GFR was below 50 mL/min.1.73 m(2) in four of the ten survivors. CONCLUSION: The prognosis of early onset renal oligohydramnios is poor. Predictive determinants of survival are: GA at diagnosis, nature of renal anomaly (hydronephrosis vs other), and presence of associated anomalies.

Could the eventual results of the NSABP* 39/RTOG** 0413 trial for partial breast irradiation (PBI) be improved by combining spherical applicators and whole breast irradiation? Radiobiology suggests it may.

There may be unacceptable risks associated with the relatively large single doses of irradiation prescribed over five days instead of over six weeks for three of the four trial arms of the NSABP39/RTOG 0413 clinical trial seeking to enlist 4,300 patients. The first arm prescribes 60 Gray (Gy) in two Gy fractions over six weeks, which is the present standard. The dose implications of the other three arms with reference to this standard were examined using the ID2 formalism. Particularly poor (non-homogeneous) dose distributions characterise spherical applicators like "MammoSite" used as a sole device for accelerated partial breast irradiation (APBI). The alternative treatment, APBI done by 3-D conformal radiation, may also have a drawback, namely a sudden sharp cut-off in dose which may cause cosmetic problems due to circumscribed fibrosis and edema. Some recently published results from this trial reveal an alarming level of complications. The possible causes of these complications and poor cosmetic outcomes and how to avoid them are examined. An obstacle to the more widespread use of the "MammoSite type of device is that the device is not allowed closer than 5-7 mm from the skin or ribs; a possible remedy for this restriction is offered. It is also intended to make the relevant radiobiological principles usable for surgical oncologists.

Development and growth in very preterm infants in relation to NIDCAP in a Dutch NICU: two years of follow-up.

AIM: To study development and growth in relation to newborn individualized developmental and assessment program (NIDCAP) for infants born with a gestational age of less than 30 weeks. METHODS: Developmental outcome of surviving infants, 25 in the NIDCAP group and 24 in the conventional care group, in a prospective phase-lag cohort study performed in a Dutch level III neonatal intensive care unit (NICU) was compared. Main outcome measure was the Bayley scales of infant development-II (BSID-II) at 24 months corrected age. Secondary outcomes were neurobehavioral and developmental outcome and growth at term, 6, 12 and 24 months. RESULTS: Accounting for group differences and known outcome predictors no significant differences were seen between both care groups in BSID-II at 24 months. At term age NIDCAP infants scored statistically significant lower on neurobehavioral competence; motor system (median [IQR] 4.8 [2.9-5.0] vs. 5.2 [4.3-5.7], p = 0.021) and autonomic stability (median [IQR] 5.7 [4.8-6.7] vs. 7.0 [6.0-7.7], p = 0.001). No differences were seen in other developmental outcomes. After adjustment for background differences, growth parameters were comparable between groups during the first 24 months of life. CONCLUSION: At present, the strength of conclusions to be drawn about the effect of NIDCAP on developmental outcome or growth at 24 months of age is restricted. Further studies employing standardized assessment approaches including choice of measurement instruments and time points are needed.

Using virtual reality for evaluation of fetal ambiguous genitalia.

OBJECTIVE: The utility of a virtual reality system was examined in the visualization of three-dimensional (3D) ultrasound images of fetal ambiguous genitalia. METHODS: In 2005, fetal ambiguous genitalia were diagnosed in four patients referred to our department for prenatal ultrasound assessment. The patients were examined by two-dimensional (2D) and 3D ultrasound and, subsequently, the volumes obtained on 3D ultrasound were visualized in the BARCO I-Space virtual reality system. This system projects stereoscopic images on three walls and the floor of a small 'room', allowing several viewers to see a 3D 'hologram' of the data being visualized. The results of 2D and 3D ultrasound examination and the virtual reality images of the I-Space were compared with diagnoses made postpartum. RESULTS: In all cases, prenatal diagnosis was unclear based on 2D ultrasound alone. Surface rendering of 3D data provided an impression of ambiguity, but diagnosis based on these data proved incorrect at birth in three cases. Conclusions based on the evaluation of 3D volumes in virtual reality best fitted the postpartum diagnosis in all cases. CONCLUSIONS: This study suggests that by evaluation of the genitals in the I-Space, a better impression of genital ambiguity can be established. Binocular depth perception appeared particularly useful in distinguishing either a micropenis or enlarged clitoris from labia minora, since it helps in the estimation of size and position. Therefore, we see potential for the application of virtual reality not only for the evaluation of fetal ambiguous genitalia, but in all those cases where depth perception would improve the visualization of anatomical structures.

Maternal temperature during labour.

OBJECTIVE: The aim of this study was to describe the variation of normal maternal temperature during labour. Design A prospective cohort study. SETTING: Two hospitals in Amsterdam, the Netherlands. POPULATION: All women with a live singleton pregnancy and a gestational age of 36 weeks or more admitted to the delivery ward from June 2000 to January 2002. METHODS: Maternal temperature was measured rectally every 2-3 hours from admission until the beginning of second stage, and 1-hour postpartum. Normal labour (n = 843) was defined as gestational age > or =37 weeks, spontaneous onset of labour, rupture of membranes <18 hours before birth, normal progress of labour without the need for augmentation or epidural analgesia and spontaneous vaginal delivery of a healthy infant. The remaining group was classified as abnormal (n = 2209). MAIN OUTCOME MEASURES: Rectal measured temperature in degrees Celsius. RESULTS: The mean temperature during labour in the complete study population increased from 37.1 degrees C at the beginning of labour to 37.4 degrees C after 22 hours. Temperature in the abnormal labour group was equal to the normal labour group during the first 3 hours of labour (P > 0.05) but increased thereafter. CONCLUSIONS: At the beginning of labour, temperature was 37.1 degrees C. Temperature increased slowly during labour and was 37.4 degrees C (2SD 1.2) after 22 hours. The upper 2SD limit for normal temperature did not follow a circadian pattern and time of day is not relevant for the classification of normal versus elevated temperature.

Individualized developmental care in a Dutch NICU: short-term clinical outcome.

AIM: To compare the short-term clinical outcomes of Newborn Individualized Developmental Care and Assessment Program (NIDCAP) and conventional care. METHODS: A prospective phase-lag cohort study was performed in a Dutch tertiary level neonatal intensive care unit (NICU). Infants born before 30 weeks of gestational age (GA) were included, 26 in the conventional and 25 in the NIDCAP group. Outcomes were respiratory status, cerebral ultrasound findings, growth and length of NICU stay. RESULTS: At study entry, NIDCAP infants had a lower birth weight (mean [SD]: 1043 [191] vs. 1154 [174] g, p = 0.044), were more often small for GA (8 vs. 2, p = 0.038), had smaller head circumferences (mean [SD]: 25.1 [1.3] vs. 26.1 [1.8] cm, p = 0.041) and were less often multiples (6 vs. 14, p = 0.029) than conventional care infants. During NICU stay, more infants in the NIDCAP group developed pneumonia (9 vs. 3, p = 0.040) due to nosocomial infections. After adjustment for these differences, a decreased risk for more severe cerebral damage in favour of NIDCAP was seen (Odds ratio: 0.12, 95% CI: 0.03-0.46, p = 0.002). No differences were observed for the other outcomes. CONCLUSIONS: We conclude with precaution that in this phase-lag cohort study NIDCAP may have resulted in less severe cerebral damage, but was not associated with other clinical outcomes. In light of these findings, NIDCAP deserves further exploration.

[Withholding treatment in terminally-ill newborns with Islamic parents]. / Abstineren bij ernstig zieke pasgeborenen van islamitische ouders.

End-of-life decisions for terminally-ill newborn infants are usually made with the consent of parents as well as physicians, but may occasionally involve disagreement about which decision is in the best interest of the child. Paediatricians, while acting in accordance with the principle of respecting the autonomy of the parents, may collide with their own motive of avoiding pointless suffering of the infant. Based on their religious beliefs Islamic parents may not consent to an end-of-life decision. Three newborn girls who eventually died had been suffering from a skeletal dysplasia and a serious bronchopulmonary dysplasia, serious intractable deterioration after surgery for necrotising enterocolitis, and trisomy 18 respectively. In the first two cases there was no preceding consensus between parents and physicians and the girls died after more suffering than the paediatrician found acceptable. The physicians should aspire to prevent conflict situations by paying sufficient attention to the differences in beliefs. This demands that physicians understand and respect different beliefs and that they are able to communicate on the subject of these differences. It is important to Islamic parents that the natural course allows Allah to exercise his authority over life and death, and human dignity. Doing the best for the child is often more important than respect for patient or parent autonomy.

Oesophageal atresia in premature infants: an analysis of morbidity and mortality over a period of 20 years.

AIM: To determine the morbidity and mortality of premature infants born with oesophageal atresia (OA) and to evaluate historical changes in morbidity and mortality over time. METHODS: Retrospective analysis of morbidity and mortality of all patients admitted for OA, with or without tracheo-oesophageal fistula, between 1982 and 2002. RESULTS: The study group consisted of 197 consecutive patients, of whom 55 (28%) were premature and 21 (11%) very premature. Type A atresia was found more often in very premature and premature infants than in those born at term (p = 0.02). Type E atresia was not found in the premature group (p = 0.004). At least one associated congenital anomaly was also present in 121 patients (61%). Postoperative complications developed more often in very premature and premature infants than in those born at term (p < 0.001). Gastro-oesophageal reflux was diagnosed in 32/76 premature infants and in 41/121 term infants (p = 0.001). Mortality among very premature and premature infants was higher than among those born at term (p = 0.003). Withdrawal of treatment was the most frequent cause of death. CONCLUSION: Premature infants with OA have a higher morbidity and mortality than term infants with OA. The complications of prematurity contribute significantly to morbidity and mortality in premature infants with OA. There is no reason to refrain from the standard treatment of OA in premature infants with no severe associated congenital anomalies.

Early versus late treatment of posthaemorrhagic ventricular dilatation: results of a retrospective study from five neonatal intensive care units in The Netherlands.

UNLABELLED: Posthaemorrhagic ventricular dilatation (PHVD) in very preterm infants carries a poor prognosis. As earlier studies have failed to show a benefit of early intervention, it is recommended that PHVD be first treated when head circumference is rapidly increasing and/or when symptoms of raised intracranial pressure develop. Infants with PHVD, admitted to 5 of the 10 Dutch neonatal intensive care units were studied retrospectively, to investigate whether there was a difference in the time of onset of treatment of PHVD and, if so, whether this was associated with a difference in the requirement of a ventriculo-peritoneal (VP) shunt and/or neurodevelopmental outcome. The surviving infants with a gestational age <34 wk, born between 1992 and 1996, diagnosed as having a grade III haemorrhage according to Papile on cranial ultrasound and who developed PHVD were included in the study. PHVD was defined as a ventricular index (VI) exceeding the 97th percentile according to Levene (1981), and severe PHVD as a VI crossing the p 97 + 4 mm line. Ninety-five infants met the entry criteria. Intervention was not deemed necessary in 22 infants, because of lack of progression. In 31 infants lumbar punctures (LP) were done before the p 97 + 4 mm line was crossed (early intervention). In 20/31 infants, stabilization occurred. In 9 a subcutaneous reservoir was placed, with subsequent stabilization in 6. In 5/31 infants a VP shunt was eventually inserted. In 42 infants treatment was started once the p 97 + 4 mm line was crossed (late intervention). In 30 infants LPs were performed and in 17 of these a VP shunt was eventually inserted. In 11 infants a subcutaneous reservoir was immediately inserted and in 8 of these infants a VP shunt was needed. In one infant a VP shunt was immediately inserted, without any other form of treatment. Infants with late intervention crossed the p 97 + 4 mm earlier (p 0.03) and needed a shunt (26/42; 62%) more often than those with early intervention (5/31; 16%). Early LP was associated with a strongly reduced risk of VP-shunting (odds ratio = 0.22, 95% confidence interval: 0.08-0.62). The number of infants who developed a moderate or severe handicap was also higher (11/42; 26%) in the late intervention group, compared with those not requiring any intervention (3/22; 14%) or treated early (5/31; 16%). CONCLUSION: In this retrospective study, infants receiving late intervention required shunt insertion significantly more often than those treated early. A randomized prospective intervention study, comparing early and late drainage, is required to further assess the role of earlier intervention.

Stereotactic proton beam therapy of skull base meningiomas.

PURPOSE: To review outcomes for patients with skull base meningiomas treated using the stereotactic proton beam at the National Accelerator Center (NAC), Republic of South Africa. METHODS AND MATERIALS: Since 1993, 27 patients with intracranial meningiomas have been treated stereotactically with protons at NAC. Of those, 23 were located on the skull base, were large or had complex shapes, and were treated with radical intent. Both stereotactic radiotherapy (SRT, 16 or more fractions) and hypofractionated stereotactic radiotherapy (HSRT, 3 fractions) were used. Eighteen patients underwent proton HSRT, while 5 patients were treated with SRT. The mean target volume for the HSRT group was 15.6 cm(3) (range 2.6-63 cm(3)). The mean ICRU reference dose was 20.3 cobalt Gray equivalent (CGyE), and the mean minimum planning target dose was 16.3 CGyE. The mean clinical and radiologic follow-up periods were 40 and 31 months respectively. The mean volume in the SRT group was 43.7 cm(3), with ICRU reference doses ranging from 54 CGyE in 27 fractions to 61.6 CGyE in 16 fractions. RESULTS: In the HSRT group, 16/18 (89%) of patients remained clinically stable or improved, while 2/18 (11%) deteriorated. Radiologic control was achieved in 88% of patients, while 2 patients had a marginal failure. Among the 5 SRT patients, 2 were clinically better, and 3 remained stable. All SRT patients achieved radiologic control. Three patients (13%), 2 of them in the HSRT group, suffered permanent neurologic deficits. Analyzing different dose/fractionation schedules, an alpha/beta value of 3.7 Gy for meningiomas is estimated. CONCLUSION: Proton irradiation is effective and safe in controlling large and complex-shaped skull base meningiomas.

Assessment of electroporation by flow cytometry.

BACKGROUND: Electroporation accomplishes transient permeabilization of cells and thus aids in the uptake of drugs. The method has been employed clinically in the treatment of dermatological tumors with bleomycin. The conditions of electroporation are still largely empirical and information is lacking as to the interrelationships among voltage pulse height, pulse number and toxicity, cell permeation, drug uptake, and effects on drug toxicity. We used propidium iodide (PI) and flow cytometry to define cell permeation into cytoplasmic and nuclear compartments to determine the improvements of drug toxicity that can be accomplished by electroporation. METHODS: Human squamous carcinoma cells of defined TP53 status and normal human epithelial cells were subjected to electroporation using a square wave pulse generator in the range of 0-5,000 V/cm. Flow cytometry served to establish entry of the drug reporter, PI, into the cytoplasm and nucleus. A dye staining method served to establish cell survival and to determine the toxicity of bleomycin alone, electroporation alone, and electroporation with bleomycin. RESULTS: The electric field intensity (EFI) required to produce 50% permeabilization (EP(50)) is cell type dependent. The EP(50) varied from 1,465 to 2,027 V/cm. An EFI below 900 V/cm is growth stimulatory whereas an EFI in excess of 1,000 V/cm is growth inhibitory. An EFI of 1,000 V/cm is sufficient to increase bleomycin toxicity by a factor of 2-3. A differential electroporation efficiency is observed between normal and tumor cells. CONCLUSIONS: Tumor cells can be targeted preferentially at electroporation voltages where normal cells are less permeable.

Liberal diagnosis and treatment of intrauterine infection reduces early-onset neonatal group B streptococcal infection but not sepsis by other pathogens.

OBJECTIVE: Comparison of the incidence and case fatality of early-onset group B streptococcus sepsis and sepsis caused by other pathogens in neonates after change of management of intrauterine infection. METHODS: All infants delivered from 1988 through 1997 at a gestational age > or = 24 weeks with a birth weight > or = 500 gram without lethal congenital abnormalities were eligible for inclusion. Infants delivered by cesarean section before the onset of labor or rupture of membranes were excluded. During the first period (1988-1991) intrauterine infection was diagnosed by a temperature > 38 degrees C, during the second period (1992-1997) this diagnosis was made at a lower temperature (> or = 37.8 degrees C) or by fetal tachycardia > or = 160/min. Treatment of intrauterine infection was similar during both periods with 3 x 2 gram amoxicillin and 1 x 240 mg gentamicin every 24 hours intravenously during labor. Prophylactic treatment during labor was only given to women with a history of an earlier infant with early-onset group B streptococcus sepsis. RESULTS: During the first period 6,103 infants were included, during the second period 8,504. Intrauterine infection was diagnosed and treated more often in the second period (7.1% vs. 2.6%). The incidence of early-onset group B streptococcus sepsis was significantly lower in the second period than in the first period [0.2% vs. 0.4%; OR 0.5 (0.3-0.9)] and survival without disability higher [80% vs. 52%; OR 4.5 (1.4-16.5)]. However, in both periods the overall incidence of neonatal sepsis (3.6% vs. 3.5%) and overall mortality because of sepsis (14.3% vs.13.1%) were similar. CONCLUSIONS: Although the early detection of clinical signs of intrauterine infection might have been effective for the prevention of serious sequelae of early-onset group B streptococcus sepsis the overall incidence and mortality from neonatal sepsis remained unchanged. Evaluation of preventive measures for early-onset group B streptococcus sepsis should always take the incidence of neonatal sepsis caused by other pathogens into account.

Somatosensory evoked potentials in very preterm infants.

OBJECTIVE: Cross-sectional and longitudinal reference values of cortical N(1) peak latency of the median nerve SEP in very preterm infants. METHODS: In infants in a placebo control group within an L-thyroxine supplementation trial, born at less than 30 weeks' gestation, cortical N(1) peak latency was measured at 2 weeks, at term and at 6 months corrected age. Cross-sectional N(1) latency values obtained in 50 infants and complete series of longitudinal values obtained in 15 infants were analyzed in relation to postmenstrual age (PMA). RESULTS: Mean N(1) latency decreased from 66 ms at 2 weeks to 38 ms at term and 20 ms at 6 months corrected age. Possible confounding factors did not have any significant effect on N(1) latency at 2 weeks or at term age except cranial ultrasound abnormalities at 2 weeks of age. CONCLUSIONS: Longitudinal N(1) latency values were consistent with cross-sectional N(1) latency values. The observed N(1) latency at term and at 6 months corrected age suggest that extrauterine maturation of the somatosensory pathway in infants born at less than 30 weeks' gestation is delayed by extrauterine life.

Neurologic development of the newborn and young child in relation to maternal thyroid function.

A prospective observational study was performed in pregnant women with known thyroid disease. We studied the effect of maternal thyroid function in the first half of pregnancy on the neurologic development of the infant in the first 2 y of life. Clinical and thyroid function data were collected from 20 pregnant women with known thyroid disease and their newborn children. Infants were divided into three groups according to their maternal thyroid function within the first half of pregnancy: Group A (n = 7): maternal subclinical hypothyroidism, Group B (n = 6): maternal euthyroidism, and Group C (n = 7): maternal hyperthyroidism or subclinical hyperthyroidism. Neurophysiologic, i.e. motor nerve conduction velocity and somatosensory evoked potentials and neurologic and developmental (Bayley scales) assessments were done. One infant, born to a mother with Graves' disease, developed transient hyperthyroidism. At the age of 6 and 12 mo, the mean mental developmental index (MDI) score was 16 points lower for infants in Group A than for those in Group B (p = 0.03 and 0.02, respectively). At the age of 24 mo, the mean MDI score was 6 points lower, which was not statistically significant. Neurophysiologic and neurologic assessments and the mean Psychomotor Developmental scores did not differ among the three groups. In conclusion, maternal subclinical hypothyroidism in the first half of pregnancy was associated with a lower mean MDI score in their infants during the first year of life.

Radiation related prognostic factors in radiation oncology.

1. The outcome of a course of radiotherapy is very dependent on the dose per fraction. The smaller the dose per fraction, as a general rule, the better the sparing of the late reacting normal tissues. 2. Overall treatment time is important, especially for tumours with a rapid doubling time. In such a case, the ideal of small doses per fraction (to save late reacting tissues) as well as a short overall treatment time (to offset the effect of repopulating) can be achieved by small doses per fraction applied two to three times per day, including Saturdays or weekends. 3. The BED (biologically effective dose) is a simple to use formula indicating the effects of fractionation. The most important term in the formula is the alpha/beta ratio which is available from experimental work for many tumours and tissues and can be looked up. As a guide, an alpha/beta ratio of 10 for early (acute) reaction and for tumour effects, and an alpha/beta ratio of 2 for late effects plus normal tissue complications can be used. 4. The application of the BED demonstrates that for HDR intracavitary therapy for cervical carcinoma, the biologically relevant dose lateral to point M(A) falls very much more rapidly than the nominal dose. Line sources are shown by comparison with other published reports, not to be intrinsically inferior to tandem ring/tandem ovoid systems and may have advantages the more cumbersome systems do not have, and may have the large advantage of allowing multiple small fractions without anaesthesia. For the particular line source system under discussion, water in a 40 cm3 Foleys bulb is used as the protecting medium for the posterior bladder wall and the anterior rectum. This particular system allows fraction sizes far smaller than 9.1 Gy at point (M)A, e.g. 3 Gy, which bestows an even greater benefit in terms of the therapeutic ratio according to BED10 and BED2 calculations.

Motor nerve conduction velocity in very preterm infants.

Sufficient reference values for motor nerve conduction velocity (MNCV) in very preterm infants are not yet available. In the placebo infants within an L-thyroxine supplementation trial, born at less than 30 weeks' gestation, ulnar and posterior tibial MNCV measurements were performed shortly after birth. Repeated measurements were done at 2 weeks, at term, and at 6 months corrected age. Cross-sectional MNCV values obtained in 50 infants and longitudinal MNCV values obtained in 15 infants were analyzed in relation to postmenstrual age (PMA). Mean ulnar MNCV increased from 13 to 44 m/s and mean tibial MNCV from 11 to 37 m/s. Motor nerve conduction velocity was clearly related to PMA. Longitudinal MNCV values were consistent with cross-sectional MNCV values. Possible confounding factors did not have any significant effect on MNCV. In the ulnar nerve, extrauterine maturation during the first 2 weeks of life was delayed compared with intrauterine maturation.