Relationship between myoelectric activity in masticatory muscles and bite force

Myoelectric activity in the anterior and posterior temporalis and in the masseter muscle was assessed in five subjects biting unilaterally on a bite fork at 50, 100 and 200 N for 60 s. The bite fork was placed between the right first premolars and the first molars. The ipsilateral muscle activity was recorded first, and the contralateral side was evaluated 1 wk later. The relationship between exerted force and EMG-activity was expressed as ratios between EMG-activity and related bite force. EMG-activity increased with increasing force for all muscles tested. Linearity was found for the anterior temporal muscle, but not for the other muscles. Four of the subjects participated in an endurance test, exerting maximum bite force on the right side for as long as possible. The EMG activity of the right masseter muscle was closely related to bite force, in contrast to the other tested muscles. The activity of the left muscles increased at the end of the endurance test.     

A Prospective Study of Rotavirus Infections in Neonatal and Maternity Wards

ABSTRACT. The occurrence and symptomatology of rotavirus infections was studied at three maternity wards and one neonatal unit. Rotavirus was identified in 12.7% of 553 infants and 1.3% of 542 mothers at the maternity wards. Infections were more frequent in a mixed obstetric/ gynecology ward than in the pure obstetric wards. Only 10% of the infants had symptomatic infections. Subgroups of rotavirus was determined in 41 infants: 22 of subgroup I and 19 of subgroup II, which is the subgroup accounting for the majority of childhood gastroenteritis. Rotavirus was found in faecal samples from 37% of the infants at the neonatal unit during an eight-month survey. A seasonal variation with most infections during colder months was seen. Subgroup determination was possible in 29 cases, 14 subgroup I and 15 subgroup II. Fifteen per cent of the infections demonstrated diarrheal symptoms. No significant difference among other clinical data registered was seen among rotavirus infected compared to the non-infected infants. We conclude that neonatal rotavirus infections occur as an endemic infection at our maternity wards possibly combined with infections due to external sources of virus in mixed wards and neonatal units     

Psychological Consequences of Neonatal Screening for α1 Antitrypsin Deficiency (ATD)

ABSTRACT. The parents of 61 children with ATD typically attended repeated doctor's appointments concerning the child's ATD during the first years of life. Many (30-40 %) of the parents felt somewhat relieved about the ATD after the first appointment. Parental attitudes toward the appointments varied considerably within the sample, being related to the physician's reported knowledgeability-understandability regarding ATD and emotional supportiveness (toward mothers). Most parents were positive and few were negative toward the child's ATD having been identified at this age. Repeated blood tests for the child's liver function were experienced negatively by most parents. The parents'recommendations concerning screening and follow-up of ATD in children are presented.     

Psychological Consequences of Neonatal Screening for α1-Antitrypsin Deficiency

ABSTRACT. Medical record information and retrospective parental reports at interview indicated that the 61 families were typically first contacted about the child's α₁-antitrypsin deficiency (ATD) during its first 6 months of life, when a physician called the mother on the telephone and told her at least something about the child's ATD. Most parents felt they had received unclear or inadequate information. A majority initially conceived of ATD as representing an imminent, serious danger to the child's health. Most of the mothers (78 %) and many of the fathers (58%) reported having immediately had negative emotional reactions, most often worry, anxiety and fear. These reactions were often long-lasting and, in mothers, typically strong.     

Sympathetic and cardiovascular activity during cataplexy in narcolepsy

Autonomic nervous system activity changes have been described during cataplexy as playing a role in triggering it. To confirm these previous findings, we investigated the time course of sympathetic and cardiovascular activities during cataplexy. We made for the first time microneurographic recordings of 10 cataplectic episodes in three patients with hypocretin‐deficient narcolepsy. During microneurography, muscle sympathetic nerve activity (MSNA) was recorded simultaneously with heart rate (HR), respiratory movements, arterial finger blood pressure (BP), electroencephalography, electro‐oculogram and superficial electromyogram. Results showed no significant autonomic changes before the onset of the cataplectic episodes. Cataplexy was associated with a significant increase in MSNA and BP compared with baseline, whereas HR was markedly decreased. An irregular breathing pattern mainly characterized by apnea typically occurred during the attacks. In conclusion, our findings did not show significant changes in autonomic activity prior to cataplexy onset, ruling out a triggering role of the autonomic system. However, cataplexy was associated with co‐activation of sympathetic and parasympathetic autonomic systems, a pattern reminiscent of that reported during the vigilance reaction in animals.