Changes of tissue creatine concentrations upon oral supplementation of creatine-monohydrate in various animal species

Creatine is a nutritional supplement with major application as ergogenic and neuroprotective substrate. Varying supplementation protocols differing in dosage and duration have been applied but systematic studies of total creatine (creatine and phosphocreatine) content in the various organs of interest are lacking. We investigated changes of total creatine concentrations in brain, muscle, heart, kidney, liver, lung and venous/portal plasma of guinea pigs, mice and rats in response to 2-8 weeks oral creatine-monohydrate supplementation (1.3-2 g/kg/d; 1.4-2.8% of dietary intake). Analysis of creatine and phosphocreatine content was performed by high performance liquid chromatography. Total creatine was determined as the sum of creatine and phosphocreatine. Presupplementation total creatine concentrations were high in brain, skeletal and heart muscle (10-22 micromol/g wet weight), and low in liver, kidney and lung (5-8 micromol/g wet weight). During creatine supplementation, the relative increase of total creatine was low (15-55% of presupplementation values) in organs with high presupplementation concentrations, and high (260-500% of presupplementation values) in organs with low presupplementation concentrations. The increase of total creatine concentrations was most pronounced after 4 weeks of supplementation. In muscle, brain, kidney and lungs, an additional increase (p<0.01) was observed between 2-4 and 2-8 weeks of supplementation. Absolute concentrations of phosphocreatine increased, but there was no increase of the relative (percentual) proportion of phosphocreatine (14-45%) during supplementation. Statistical comparison of total creatine concentrations across the species revealed no systematically differences in organ distribution and in time points of supplementation. Results suggest that in organs with low presupplementation creatine levels (liver, kidney), a major determinant of creatine uptake is an extra-intracellular concentration gradient. In organs with high presupplementation total creatine levels like brain, skeletal and heart muscle, the maximum capacity of creatine accumulation is low compared to other organs. A supplementation period of 2 to 4 weeks is necessary for significant augmentation of the creatine pool in these organs.

[Communication barriers in the management of immigrants and their children. An analysis and possible solutions based on case reports]

Up to 41% of patients treated in health care institutions and hospitals in Vienna are non-German-speaking. As one half of the foreign population of Vienna speaks little or no German, their treatment in health care institutions is a difficult issue. Based on exemplary case reports, linguistic and socio-cultural communication barriers in health care are presented and the problematic area of foreign-language communication is analysed. Misunderstandings due to communication barriers not only have a negative financial impact on health care economy, they also complicate the individual care of these patients. Based on the experience gained thus far and in concurrence with the developments in other European countries, the use of professional interpreters who combine their role as linguistic intermediaries with the cultural features of foreign-language patients (community interpreters) should be encouraged. The use of specifically trained internal hospital staff is recommended as well. A concept to coordinate central organisations that provide interpreters in the public field may substantially enhance the quality and efficiency of health care in this special situation.

[Prevalence of sleep disorders in school children between 11 and 15 years of age]

Little is known about sleep disorders in children and adolescents that might affect physical and emotional well-being. Depending on age and size of the cohort group, and differences in questionnaires, prevalence varies between 1-43% in international studies. We examined the prevalence of symptoms characteristic of sleep disorders in school aged children with a questionnaire which allows indication of symptoms by the children themselves.

METHODS

An anonymous questionnaire, based on the German Dresden questionnaire, with 22 questions concerning the main symptoms of obstructive sleep apnea syndrome (OSAS), general symptoms of para- and insomnia as well as sociodemographic data, was developed. 332 pupils (age: 11-15 y, mean: 12.75 y; median: 12 y; 56% female, 44% male) in 2 high schools in Vienna were investigated.

RESULTS

28% (n = 93/332) of the examined group reported snoring (the main symptom of OSAS) and/or insomnia (night waking almost every night) or parasomnia (nightmares, night terrors or sleepwalking almost every night). 15% (n = 14/93) of this subgroup reported snoring and para- or insomnia coincidentally. Girls were affected more frequently than boys by nocturnal awakening (79% vs. 56%, p < 0.001) and nightmares (64% vs. 52%, p < 0.01). The snoring group (21% (71/332) of all examined children) was affected more frequently by mouth dryness (16% vs. 4%, p < 0.001), pallor (7% vs. 3%, p < 0.01), night sweats (6% vs. 1%, p < 0.05) and from the following sleep disorders: nightmares (10% vs. 2%, p < 0.01), night terrors (4% vs. 1.5%, p < 0.001), sleepwalking (1.4% vs. 1%, p < 0.05) and nocturnal awakening (16% vs. 5%, p < 0.01).

DISCUSSION

Almost every fifth child reports about at least one main symptom characteristic of OSAS. The statistically significant relation between symptoms of OSAS and non-organic sleep disorders shows the necessity of interdisciplinary focusing on sleep disorders. Further epidemiological studies need to be carried out in order to clarify the role of sleep anamnesis in the diagnosis and management of sleep disorders during childhood.

[Orthostasis in halothane anesthesia. A model situation for studying cerebrovascular autoregulation in infants]

Halothane causes impairment of cerebrovascular reactivity and autoregulation. We used transcranial Doppler sonography (TCD) to investigate the reaction patterns of cerebral blood flow velocities (CBFV) during a standardized orthostatic maneuver after premedication and during halothane anesthesia in infants. After premedication orthostasis led to no significant changes in CBFV. During halothane anesthesia CBFV was significantly higher than after premedication, and orthostasis induced a significant decrease in CBFV compared to values obtained in horizontal position. Heart rate and mean blood pressure were significantly lower than before medication during halothane anesthesia. The observed changes in CBFV during halothane anesthesia represent a characteristic pattern of impaired cerebral autoregulation. The changes in CBFV and heart rate demonstrate that neither systemic nor cerebral hemodynamics compensate for hydrostatic inducement during halothane anesthesia. The tilting test is a useful tool for determining cerebral autoregulation capacity in infants.

[Heart rate variability--physiology, methods of registration and application in pediatric sleep laboratory]

Heart rate variability (HRV) has become the focus of interest of a multitude of investigations being a parameter that can easily be recorded. Accepted clinical indications in adults include evaluation of diabetic neuropathy and prediction of prognosis after myocardial infarction in adults. In children, HRV is regularly being registered in the pediatric sleep laboratory in sleep related breathing disorders, after apparent life threatening events, or in infants with assumed increased risk for sudden infant death syndrome. However, uniform interpretation criteria have not been established in these situations, at least partially due to insufficient understanding of physiology and pathophysiology of HRV in this age group. In this overview, current knowledge on HRV in infants and children is summarized and its clinical relevance discussed. In addition, technical requirements and methods of analysis which have a major impact on calculated parameters are being presented.

[Viennese SIDS prevention campaign-- a quality management project]

At the 4th Austrian SIDS Consensus Meeting (1998), consultation was the focus of attention. Secure sleep, the Vienna SIDS prevention campaign, is an information campaign in cooperation with the children's hospitals of Vienna with the aim of reducing the incidence of SIDS in and around Vienna. The campaign was intended to spread awareness concerning care measures to reduce SIDS as well as to reduce SIDS related anxiety (SRA) among anxious parents. The Vienna SIDS prevention campaign is a quality management project, the core of which is consultation. Demands upon the structural quality of a SIDS consultation office include the expertise, communication skills and psychological competence of the consulting team. This can be achieved through interdisciplinary continuing education, international networking and training in communication skills. Priority is given to supporting care for the client by an interdisciplinary team headed by a case manager with the required communication skills. The qualitative outcome is defined by a primary objective medical goal (reduction of SIDS mortality) and a secondary subjective psychological goal (reduction of SRA). It also includes raising effectiveness and efficiency through optimal consultation and, finally, reducing costs by saving expenditure for monitors. The quality of SIDS consultation can be measured by evaluating satisfaction in patients as well as among co-workers.

[Evaluation of the cardiorespiratory monitor SpiroGuard C for infants. Improved registration of respiratory events by new sensors and intelligent alarm management system]

OBJECTIVES

The SpiroGuard C is a commercially available cardiorespiratory monitor working with field plethysmography, wireless signal transmission and a novel alarm management system. In order to determine the recognition rates for central, mixed and obstructive apneas, a prospective clinical trial was performed comparing frequency and kind of signals from the monitor with those simultaneously registered by polysomnographic studies.

DESIGN

Normal respiratory and alarm signals of the monitor under investigation were integrated into a polysomnographic setting. All central, mixed and obstructive apneas lasting more than 10 seconds as well as all alarms obtained from the monitor were evaluated.

RESULTS

47 series of monitor recordings could be evaluated in parallel to polysomnographic studies: the detection rate for central apneas was 298/328 (90.85%), for mixed apneas 9/41 (21.95%) and for obstructive apneas 0/36 (0%). Out of the total of 708 registered alarms 359 (50.71%) were false alarms, 307 (43.36%) were apnea-related and 42/708 (5.93%) were alarms due to technical problems. 177 of the 359 false alarms (49.30%) occurred during apneas that were shorter than 10 seconds, 119 (33.15%) were related to bad signal quality, and 55 (15.32%) were caused by movement artifacts.

CONCLUSION

The recognition rate for central apneas was high (> 90%), while sensitivity for mixed and obstructive apneas was not satisfactory. Approximately half of the alarms were false alarms. These could be reduced by setting the apnea detection time to > 15 seconds, by tighter fastening of the respiration belt (improving the signal transmission), and by turning off the instrument when the child is awake and physically active. The wireless system renders the SpiroGuard C an attractive alternative for home monitoring.

SIDS related anxiety--a risk factor analysis

BACKGROUND

The growing public interest in the Sudden Infant Death Syndrome (SIDS) has led to a new psychological problem--SIDS related anxiety (SRA). General public awareness, unfavourable experience in the past, present problems with the infant or insufficient support from the family may lead or contribute to SRA.

OBJECTIVE

The study was conducted to explore which of these factors contribute most to the development of SRA.

PATIENTS AND METHODS

Families visiting our outpatient clinic during 18 months were interviewed by means of a structured questionnaire. We assessed demographic data, obstetric history, experience of child loss, pregnancy and delivery complications, infant morbidity, family-child interaction, family support and the relation of each of these single factors to SRA.

RESULTS

Of 169 families, 58% (98/169) admitted to suffer from SRA and 21% (32/156) from severe SRA. We found a strong and significant relationship between previous experience of child loss and SRA (OR: 2.95, 95% CI: 1.43-6.09, P < 0.005) and between pregnancy complications and SRA (OR: 2.19, 95% CI: 1.18-4.08, P < 0.05). There were no significant relationships between SRA and either delivery complications, child morbidity, impaired family-child interaction or insufficient support from the family.

CONCLUSIONS

SRA occurs in an unexpectedly large proportion of families visiting a SIDS counseling clinic. SRA must be taken seriously, and psychological or psychotherapeutic help should be offered. Prevention of SRA should include psychological care for families who experience loss of children or high-risk pregnancies.

[4th Austrian SIDS Consensus-Consultation and the Viennese SIDS prevention campaign "Secure Sleep"]

Despite numerous investigations the pathophysiologic mechanisms of SIDS have not been fully elucidated. In large epidemiologic studies highly variable SIDS mortality rates were noted between different countries and cultures. This presumably is due not only to differences in diagnostics and classification of SIDS but also in lifestyle and newborn care. The common denominator is the identification and prevention of the main risk factors: smoking, sleeping in the prone position, over-heating, wrong "bedding". SIDS prevention campaigns that have focussed upon these risk factors have led to a dramatic reduction in the incidence of SIDS. In preparation for the SIDS prevention campaign of Vienna ("Safe Sleep") the content, strategy and procedure of the Austrian prevention campaigns were analysed. The current focus is to convey a clear and uniform message in personal conversations before and after birth of the child. These conversations with parents are the most important tool to detect SIDS related anxiety and a possibly increased risk of SIDS. In the last 30 years various polysomnographic parameters were published that were associated with an increased risk of SIDS. Today there is international consent that polysomnography is not an efficient screening method to demonstrate increased risk of SIDS. Therefore the use of polysomnography, besides research purposes, has been limited to investigating clinical symptoms of infants and children. Concerning monitoring it is important to note that--in contrast to the undisputed importance of monitoring breathing disorders--the effectiveness in SIDS prevention is unproven. State of the art are instruments that monitor heart and breathing rate and have adequate storage functions. The duration of monitoring should encompass the symptomatic period as well as a safety period of three months. The monitor should not be routinely prescribed for a year. The guiding principle is "As short as possible with stringent indication". Prerequisite for the monitoring is good instruction of the parents and a continuous consultation by competent outpatient clinics.

Cerebral Doppler sonography of the neonate. A résumé after 20 years and future aspects

Up until recently the evaluation of CVR (analysis of pulsatility) had been a priority in Doppler sonography. In preterm and term infants with open fontanels and sutures this information is restricted despite its value in extreme situations. Continuous Doppler sonography allows a new approach to monitoring pathophysiologic processes. In connection with improved data recording and processing as well as progress in monitoring blood pressure and central venous pressure, new noninvasive methods of surveillance become possible. Thanks to these methods experimental and clinical research has increasingly gained insight on the autonomic nervous system over the last few years (e.g., m- and r-wave analysis during continuous measurement of arterial blood pressure and heart rate). Already well-known and newly developed functional tests (e.g., tilting test, CO2-reactivity, phase shift, and so forth) will further improve our understanding of physiologic processes and help us develop individual therapy concepts for the newborn.

Cerebral blood flow velocities in an infant with moyamoya disease

Moyamoya disease is a progressive cerebrovascular disorder with bilateral occlusion of the basal circulation and development of collateral blood supply. In a 6-month-old female with multifocal ischemic infarctions, transcranial pulsed Doppler sonography revealed extremely high and low cerebral blood flow velocities, dampened waveforms, reversed flow, and musical murmurs. Magnetic resonance angiography revealed different degrees of vascular stenosis and an abnormal collateral network. Moyamoya disease was confirmed by conventional angiography at the age of 10.5 months. Pulsed-wave transcranial Doppler sonography is a noninvasive screening method in infants at risk of moyamoya disease.

Are adult transcranial Doppler systems suitable for application in neonates?

Transcranial Doppler systems have not been available for monitoring of cerebral blood flow velocities in neonates because of potential hazardous effects of energy output from standard instruments developed for adult application. Aim of the study was to test commercially available transcranial Doppler instruments for their applicability in neonates and to develop guidelines for adaptation for safe neonatal use. Energy output of five commercially available transcranial Doppler instruments was measured with a hydrophone system and a radiation force balance. At the highest setting and at the nominal 10% attenuation level, five out of five and two out of five instruments, respectively, had an energy output above the recommended limits. Power reduction was not linear in one instrument. Evaluation of safety devices (alarm, freeze mode, energy reduction facilities, display of energy values) showed that none of the tested instruments had an optimal setting for safe neonatal application.

CONCLUSION

Commercially available transcranial Doppler instruments should be evaluated critically for their energy output prior to their application in neonates. Special software for neonatal application of transcranial Doppler systems should be developed in order to provide extremely low energy output levels and devices for indication of duration of Doppler insonation and energy output.

[Pregnancy and neonatal screening in Austria]

In Austria neonatal mortality remains higher than in comparable industrial countries. For this reason the Austrian Academy of Sciences published a study (Köck Ch., Kytir J., Münz R.: Risiko Süglingstod, Plädoyer für eine gesundheitspolitische Reform, Franz Deuticke, Wien 1988) comprising a historical review, an analysis of the present situation and proposals for improvement of the public health care programmes for pregnant women, mothers and neonates. Furthermore, current Austrian health policy is criticized on the basis of two concrete examples (the neonatal mass screening programme for inherited metabolic diseases and compulsory ultrasound screening in pregnancy). However, the authors reach their conclusions from incompletely cited and subjectively (partly falsely) interpreted scientific literature, with misleading consequences. Reviewing the literature in a more complete way, we wish to point out the superficial character of the research carried out by the authors. This kind of work should not serve as a basis for decisions in public health policy.

[Congenital metabolic diseases as a cause of acute illnesses in the neonatal period]

Inborn errors of metabolism occurring in the neonatal period both comprise diseases with clinical onset immediately after birth and diseases with clinical onset after a symptom free interval. Organ damage caused by inherited metabolic diseases can occur already in utero or--depending on oral food intake--during the first postnatal days. Unselective screening methods are applied in neonatal mass screening programs for the early detection of metabolic diseases. In cases of unspecific clinical symptoms selective screening procedures may provide an effective diagnostic tool. If a patient with suspected metabolic disease dies, body fluids and organ biopsies should be preserved for further investigations. The establishment of a genotypspecific (enzyme) diagnosis needs time and cost consuming biochemical procedures. It is a prior condition for prenatal diagnosis in further pregnancies.

[The value of prenatal ultrasound screening exemplified by abnormalities of the urogenital system. Data from the Styrian malformation register 1985 to 1987]

Over a three-year period (1985 to 1987), the number of fetal malformations was entered into Styrian Malformation Register (SMR). The data were compared with those of the Austrian Ministry of Health. The SMR collected 137 cases of urinary tract malformations, but only six appeared in the Health Ministry statistics. This discrepancy resulted from the different data collection methods. Presently only a small percentage of fetal abnormalities is officially registered. Using the example of urinary tract malformations this paper shows the value of prenatal ultrasound screening. Such infants must be treated soon after delivery to avoid progression of parenchymal damage. Ultrasound examinations should not be restricted to pregnant women at defined risk. Registration of all prenatally diagnosed--or missed--malformations is a quality-control measurement and improves prenatal diagnosis.