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Biomedical subjects

Thomas M Berger

Publications and source records attributed to Thomas M Berger.

17 recordsLinked to original sources

Hepatocerebral mitochondrial DNA depletion syndrome caused by deoxyguanosine kinase (DGUOK) mutations.

BACKGROUND: Autosomal recessive mutations in deoxyguanosine kinase (DGUOK) have been identified in the hepatocerebral form of mitochondrial DNA (mtDNA) depletion syndrome. OBJECTIVES: To describe the clinical spectrum of DGUOK-related mtDNA depletion syndrome in 6 children and to summarize the literature. RESULTS: We identified pathogenic mutations in DGUOK in 6 children with the hepatocerebral form of mtDNA depletion syndrome. We describe the clinical, neuroradiologic, histologic, and genetic features in these children. All children showed severe hepatopathy, while involvement of other organs (skeletal muscle and brain) was variable. We identified 5 novel mutations (1 of them in 2 children) and 2 previously described mutations. Three different mutations affected the initial methionine, suggesting a mutational hot spot. One of our patients underwent liver transplantation; pathologic findings revealed (in addition to diffuse hepatopathy) a hepatocellular carcinoma, implying a possible link between mtDNA depletion syndrome and tumorigenesis. CONCLUSION: We studied 12 children with infantile hepatoencephalopathies and mtDNA depletion syndrome and found pathogenic DGUOK mutations in 6, suggesting that this gene defect is a frequent but not an exclusive cause of the hepatic form of mtDNA depletion syndrome.

Child, Preschool↗

Population-based study of bronchopulmonary dysplasia in very low birth weight infants in Switzerland.

UNLABELLED: In Switzerland, data are collected prospectively by collaborators from all nine neonatal intensive care units and their affiliated paediatric units caring for neonates, to determine survival and (pulmonary) outcome of infants with birth weights ranging from 501 to 1500 g. To assess the pulmonary outcome of very low birth weight (VLBW) infants in Switzerland in 1996 and 2000, factors associated with bronchopulmonary dysplasia (BPD) were identified and compared with pulmonary outcomes from the Vermont Oxford Network data. BPD was defined as a requirement for supplemental oxygen at 36 weeks postmenstrual age. Complete data were available for 600 and 636 VLBW infants in 1996 and in 2000, respectively. Mortality rates in Switzerland were significantly higher (1996: 19.2%, 2000: 20.8%) than in the Vermont Oxford Network (1996: 14%, 2000: 14%). Expressed as percentage of infants still hospitalised at 36 weeks postmenstrual age, 16.7% and 13.2% of Swiss VLBW infants were diagnosed with BPD in 1996 and 2000, respectively. These rates were significantly lower than in the Vermont Oxford Network (1996: 28%, 2000: 35%). Infants exposed to factors previously shown to be associated with BPD were investigated: in Switzerland, infants with a history of surfactant replacement therapy and/or mechanical ventilation had a significantly higher rate of BPD in both cohorts. Infants with postnatal transport, sepsis proven by positive blood culture and patent ductus arteriosus had a higher BPD rate only in the 1996 cohort. Between 1996 and 2000, mortality rates and incidence of BPD in VLBW infants remained unchanged in Switzerland. BPD rates in Switzerland are lower than those found in the Vermont Oxford Network whereas a mortality rate comparison displays an inverted picture. We suspect that these effects are interrelated and may be due in part to a selective approach of Swiss neonatologists to resuscitation of infants in the smallest birth weight stratum. CONCLUSION: The factors listed above have apparently become less important in the context of bronchopulmonary dysplasia and other influences, including prenatal conditions, will need to be investigated.

Bronchopulmonary Dysplasia↗

Neonatal dexamethasone induces premature microvascular maturation of the alveolar capillary network.

Postnatal glucocorticoid treatment of preterm infants was mimicked by treating newborn rats with dexamethasone (0.1-0.01 microg/g, days 1-4). This regimen has been shown to cause delayed alveolarization. Knowing that microvascular maturation (transformation of double- to single-layered capillary networks in alveolar septa) and septal thinning prevent further alveolarization, we measured septal maturation on electron photomicrographs in treated and control animals. In treated rats and before day 10, we observed a premature nonreversing microvascular maturation and a transient septal thinning, which both appeared focally. In vascular casts of both groups, we observed contacts between the two capillary layers of immature alveolar septa, which were predictive for capillary fusions. Studying serial electron microscopic sections of human lungs, we were able to confirm the postulated fusion process for the first time. We conclude that alveolar microvascular maturation indeed occurs by capillary fusion and that the dexamethasone-induced impairment of alveolarization is associated with focal premature capillary fusion.

Animals↗

Paediatric anaesthesia and inhalation agents.

Inhalation agents are amongst the mainstays of paediatric anaesthesia, as children are often induced by mask before venous access is obtained. Children do not like needles and obtaining venous access in an awake and moving child can be very demanding. Safety aspects are of particular importance in paediatric anaesthesia. Therefore, the possibility of monitoring end-tidal concentrations facilitates correct dosing in all patients, from the preterm infant weighing less than 1000 g to the adult-sized adolescent. For induction, sevoflurane has nearly universally replaced halothane, leading to increased cardiovascular safety. The main disadvantages of inhalation agents, especially sevoflurane and desflurane, are delirious behaviour and agitated states during emergence. In addition, there remains uncertainty regarding the relevance of the cerebral stimulating pattern of some of these agents. Inhalation anaesthesia has a long tradition, whereas the experience with propofol is comparatively small. The incidence and clinical relevance of the propofol infusion syndrome during clinical anaesthesia are still unknown. Inhalation anaesthesia is still considered to be the gold standard by the overwhelming majority of paediatric anaesthetists world-wide, however, intravenous techniques can be an attractive alternative in specific clinical situations.

Anesthesia, General↗

Impact of improved survival of very low-birth-weight infants on incidence and severity of bronchopulmonary dysplasia.

BACKGROUND: It has been suggested that improved survival of very low birth weight (VLBW) infants may have resulted in increased numbers of patients with bronchopulmonary dysplasia (BPD). GOAL: To determine the impact of changes in mortality on the incidence and/or severity of BPD in three different time periods with distinct respiratory support strategies. METHODS: Retrospective single center cohort study of VLBW infants: Cohort A (1986-1990): pre-surfactant era, use of conventional intermittent mandatory ventilation (IMV); cohort B (1993-1994): use of synthetic surfactant, nasopharyngeal continuous positive airway pressure (CPAP) and conventional IMV; cohort C (2000-2001): use of natural surfactant, early nasal prong CPAP, synchronized IMV with tidal volume monitoring and high frequency oscillatory ventilation (HFOV). BPD was classified as mild, moderate or severe according to Jobe and Bancalari. RESULTS: The median gestational ages and birth weights were 28 3/7 weeks and 1,120 g for cohort A (n = 97), 30 0/7 weeks and 1,340 g for cohort B (n = 100), and 29 1/7 weeks and 1,200 g for cohort C (n = 135). The use of partial or complete courses of antenatal corticosteroids (ANC) increased over time (58%, 72%, and 82%, p = 0.003). There was a 50% reduction of mortality between each time period with mortality rates of 30%, 14% and 7% in cohorts A, B and C, respectively (p < 0.001). The overall incidence of BPD was 26% in the pre-surfactant era, 11% during the mid-1990s and 19% in the most recent time period (r = -0.05, p = 0.36). Moderate and severe forms of BPD decreased over time and were seen in 11% in cohort A, 3% in cohort B and 2% in cohort C (p = 0.008). CONCLUSION: Changes in neonatal care of VLBW infants, including increased use of ANC and modified respiratory support strategies, have resulted in dramatically improved survival rates over the past 15 years without increasing moderate to severe pulmonary morbidity.

Adrenal Cortex Hormones↗

Regional anaesthetic techniques for neonatal surgery: indications and selection of techniques.

The goal of neonatal care is to optimise the outcome of term and preterm infants with minimal suffering. Neonates are rare patients for the anaesthetist, therefore personal and even global experiences are limited. This chapter focuses on strategies for dealing with common clinical situations, e.g. heel lancing, obtaining vascular access, circumcision, hernia repair and pyloric stenosis, as well as major neonatal surgery. With the exception of heel lancing, regional techniques are useful in all cases. However, a careful risk-benefit analysis is mandatory, especially when considering more invasive techniques such as epidural catheters.

Anesthesia, Conduction↗

Recent developments in paediatric regional anaesthesia.

PURPOSE OF REVIEW: This review will focus on recently published data concerning side effects and complications of paediatric regional anaesthesia, putting into perspective the currently used techniques. RECENT FINDINGS: Penile block is clearly a technique with a very large benefit and minimal side effects. Ilioinguinal nerve block, on the other hand, quite commonly leads to complications. Single-shot caudal anaesthesia is considered a safe and effective technique; however, even with this widely used block, complications such as sacral osteomyelitis can occur. Recent review articles have focussed on the role of additives for prolonging the duration of paediatric caudal anaesthesia. The use of ketamine or s-ketamine as an additive appears to be most promising for the future. SUMMARY: Paediatric regional anaesthesia is now widely used for postoperative pain relief in children. However, a careful risk-benefit analysis is always mandatory before such medical interventions are undertaken.

Journal Article↗

Fetal intracranial injuries in a preterm infant after maternal motor vehicle accident: a case report.

OBJECTIVE: To present a case of fetal intracranial injuries in a preterm infant after maternal motor vehicle accident and to review the relevant literature. DESIGN: Case report. SETTING: Neonatal and pediatric intensive care unit of a children's hospital. PATIENT: Preterm infant (gestational age, 30-6/7 wks) with intracranial injuries after maternal motor vehicle accident. RESULTS: Whereas the mother had only a closed femur fracture, her infant sustained subdural, subarachnoid, and intracerebral hemorrhages in the left parietal and temporal lobes most likely attributable to direct fetal trauma. Massive fetomaternal hemorrhage may have led additionally to hypoxia-ischemia contributing indirectly to the injury. At the last follow-up visit (chronological age, 20 months; corrected age, 18 months), there was evidence of a persistent right-sided hemiparesis in an otherwise normally developed infant. CONCLUSIONS: Motor vehicle accidents during pregnancy can be associated with fetal mortality and significant morbidity, even in the absence of severe maternal injuries. Direct (hemorrhagic) and indirect (hypoxic-ischemic) intracranial injuries should be actively sought with appropriate imaging studies.

Accidents, Traffic↗

Prevention of vitamin K deficiency bleeding with oral mixed micellar phylloquinone: results of a 6-year surveillance in Switzerland.

UNLABELLED: In 1995, a new form of vitamin K prophylaxis with two oral doses of 2 mg mixed micellar phylloquinone (Konakion MM) on the 1st and 4th day of life was introduced in Switzerland. It was hoped that this new galenic preparation of phylloquinone would protect infants with insufficient or absent bile acid excretion from late vitamin K deficiency bleeding (VKDB). Subsequently, the occurrence of VKDB was monitored prospectively between July 1, 1995 and June 30, 2001 with the help of the Swiss Paediatric Surveillance Unit (SPSU). Over a period of 6 years (475,000 deliveries), there were no cases of early (<24 h of age), one case of classical (2-7 days of life), and 18 cases of late (1-12 weeks) VKDB fulfilling standard case definitions. In 13/18 patients with late VKDB there was pre-existing liver disease and in 4/18 patients, parents had refused prophylaxis. The incidence of late VKDB for infants with completed Konakion MM prophylaxis was 2.31/100,000 (95% CI: 1.16-4.14) and for the entire population 3.79/100,000 (95% CI: 2.24-5.98). There was only one case of late VKDB after complete prophylaxis in an infant without underlying liver disease. CONCLUSION: two oral doses of 2 mg of a mixed micellar vitamin K preparation failed to abolish VKDB. The recommendations for vitamin K prophylaxis in Switzerland have therefore been changed to include a third dose at 4 weeks of age. Starting on January 1, 2004, the incidence of vitamin K deficiency bleeding will again be monitored prospectively by the Swiss Paediatric Surveillance Unit.

Administration, Oral↗

Congenital laryngotracheo-oesophageal cleft: successful ventilation with the Laryngeal Mask Airway.

A congenital laryngotracheo-oesophageal cleft is a rare airway malformation which results from incomplete separation of the larynx and trachea from the hypopharynx and oesophagus. Patients usually present with stridor, aspiration and cyanosis associated with feeding. For early diagnosis, a high index of suspicion is needed. Unless an appropriate diagnostic approach is taken, the diagnosis can be missed. The successful ventilation of a neonate with the Laryngeal Mask Airway is described.

Esophagus↗

Hyponatremia in a pediatric stroke patient: syndrome of inappropriate antidiuretic hormone secretion or cerebral salt wasting?

OBJECTIVE: To determine the potential role of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in the pathogenesis of cerebral salt wasting. DESIGN: Clinical case report. SETTING: Regional pediatric intensive care unit. PATIENT: A 3-yr-old boy with a cerebral infarct secondary to traumatic carotid artery dissection who developed hyponatremia associated with weight loss and excessive renal sodium excretion on the sixth day after hospitalization. MEASUREMENTS AND MAIN RESULTS: Plasma concentrations of ANP, BNP, antidiuretic hormone, and renin were determined serially and compared with concentrations measured in a group of eight healthy children undergoing elective surgical procedures. Compared with controls, ANP and BNP plasma concentrations on the eighth day after hospitalization were increased 1.9-fold and 7.7-fold, respectively. Thereafter, the course of ANP and BNP paralleled that of sodium and H2O excretion and remained elevated until the 14th (BNP) and 16th (ANP) days after hospitalization. Serum antidiuretic hormone and renin concentrations were within normal ranges during the entire observation period. CONCLUSION: Cerebral salt wasting is associated with elevated plasma concentrations of ANP and BNP. Natriuretic peptides may play a role in the pathogenesis of this syndrome.

Atrial Natriuretic Factor↗