不同剂量维生素D补充在早产儿中的应用研究

目的 评估不同剂量维生素D补充对胎龄≤34周早产儿出院时维生素D水平的影响,为早产儿生后合理补充维生素D提供依据。方法 选择2019年1月—2020年6月在博罗县妇幼保健计划生育服务中心出生的胎龄≤34周早产儿67例,在完全肠内喂养后开始口服维生素D,并随机分为维生素D低剂量组(n=32)和高剂量组(n=35),比较两组患儿出院时25(OH)D水平、维生素D缺乏/不足的比例及相关不良反应发生率。结果 两组患儿出生时脐带血25(OH)D水平、维生素D缺乏/不足发生率比较,差异无统计学意义(P＞0.05);出院时高剂量组血清25(OH)D水平明显高于低剂量组、维生素D缺乏/不足发生率明显低于低剂量组(t=2.872、χ²=4.189,P＜0.05),但高剂量组出院时维生素D缺乏/不足发生率仍为28.6%。结论 对于胎龄≤34周的早产儿,给予补充维生素D 800 U/d可明显改善患儿出院时维生素D缺乏或不足的情况,但对于胎龄更小、出生体重更低的超低出生体重儿,可能需要更大剂量的维生素D补充。     

Potential Association between Zika Infection and Microcephaly during 2007 Fever Outbreak,Gabon

Although Zika virus (ZIKV) circulates in sub-Saharan Africa, no case of ZIKV-associated microcephaly has thus far been reported. Here, we report evidence of a possible association between a 2007 outbreak of febrile illness and an increase in microcephaly and possibly ZIKV infection in Gabon.     

COVID-19 and Infant Hospitalizations for Seasonal Respiratory Virus Infections,New Zealand, 2020

In March 2020, a national elimination strategy for coronavirus disease was introduced in New Zealand. Since then, hospitalizations for lower respiratory tract infection among infants <2 years of age and cases of respiratory syncytial or influenza virus infection have dramatically decreased. These findings indicate additional benefits of coronavirus disease control strategies.     

Effects of priming duration on retention over the first 1 1/2 years of life

Exposing individuals to an isolated component (a prime) of a prior event alleviates its forgetting. Two experiments with 120 human infants between 3 and 18 months of age determined the minimum duration of a prime that can reactivate a forgotten memory and how long the reactivated memory persists. Infants learned an operant task, forgot it, were exposed to the prime, and later were tested for renewed retention. In Experiment 1, the minimum duration of an effective prime decreased logarithmically with age, but was always longer than the duration of a mere glance. In Experiment 2, the reactivated memory was forgotten twice as fast after a minimum-duration prime as after a full-length one, irrespective of priming delay and infant age. These data reveal that the minimum effective prime duration psychophysically equates the accessibility of forgotten memories. We conclude that priming is perceptually based with effects that are organized on a ratio (log) scale.     

Urinaryα 1 as an index of proximal tubular function in early infancy

Urinary ₁-microglobulin (U-A₁M) was measured in healthy term infants on days 1, 4, 7, 14, 28, 90 and 180 of life. U-A₁M was high until day 14 and declined thereafter. It was significantly correlated with urinary ₂-microglobulin (U-B₂M) throughout the study, but not with serum A₁M on days 1 or 7. Similar to U-B₂M, U-A₁M in the clinically stable term infants with intrauterine growth retardation (n=4–7) was not elevated on days 1–7. In the sick infants who needed immediate resuscitatio at birth (n=4–8), U-A₁M as well as U-B₂M was high on days 1–7 and then decreased to normal levels, suggesting that U-A₁M can be used as a sensitive marker of acute proximal tubular damage and its recovery. These observations indicate that U-A₁M is a useful index of proximal tubular function in early infancy.     

Premature infants in car seats: effect of sleep state on breathing

SUMMARY  Previous studies have shown that premature infants may be at risk for hypoxemia and bradycardia when placed in standard car seats. However, the relationship of such breathing abnormalities to sleep state have not been studied. The purpose of the present study was to investigate the effect of car seat positioning on respiratory patterns in preterm infants during sleep and to evaluate their relationship to sleep state. Complete polysomnography, including sleep and breathing parameters, was performed on twenty-eight premature infants. Each infant was randomly assigned to the car seat or prone (crib) position for the first recording period. Following the recording of at least two sleep cycles, the position was reversed. The percentage of active and quiet sleep was calculated and breathing parameters were measured. In the car seat, the infants spent significantly more time in active sleep and less time in quiet sleep than in the prone position, of the respiratory parameters, periodic breathing (PB) was significantly higher in the car seat. The presence of at least one abnormal breathing events (bradycardia, desaturation, PB apnoea) was also significantly higher in the car seat. An analysis of variance (ANOVA) of PB revealed significant sleep-state effect (active vs. quiet sleep), but no significant condition or interaction effects, indicating that PB was more frequent in active sleep regardless of the sleeping condition. It is concluded that increased active sleep in the car seat condition, rather than the positioning of the infant in the seat per se, may account for the increase in periodic breathing and possibly other breathing abnormalities reported in car seats.     

Laser Doppler velocimetry in retinal arteries of infants

The present study was conducted to assess the feasibility of laser Doppler velocimetry in young infants, as a prelude to ultimately undertaking such measurements in premature infants. A portable, unidirectional laser Doppler velocimeter was developed based on a Kowa RC-2 hand-held fundus camera. Six infants between 1 and 21 weeks of age were studied. Relative red blood cell velocity (f_max) at the centre of retinal arteries was measured over approximately 10 heart cycles. A pulsatility parameter (P=1–f_max.dia/f_max.sys), a summary index of vascular status, was determined from the average diastolic and systolic values of f_max. Velocity waveforms were obtained in four of the six infants. Arterial pulsatility for the group was 0.63±0.13. Precise non-invasive measurement of arterial red blood cell velocity waveforms in young infants was achieved. The high signal-to-noise ratio and temporal resolution of this data suggest that relative measurements of retinal blood flow may permit assessment of haemodynamic changes in premature infants.     

新生儿严重脑室内出血连续腰穿的疗效

目的为了治疗和预防脑室内出血后脑积水的发生和发展,改善新生儿严重脑室内出血的不良预后。方法1989年以来,对19例在出生后早期经头颅B超诊断为严重脑室内出血（IVH）患儿进行了连续腰穿（LP）治疗。结果有效16例,自动出院1例,失败2例。有效率为84．2％。有效16例初次LP日龄为14．6±5．7d,疗程23．4±12d,平均LP次数9．3±4．7次,平均LP间隔期3．1±1．6d,平均每次放液量6．7±2ml,LP治疗后起效天数为10．1±7．8d。2例在连续LP的同时联用乙酰唑胺治疗亦取得显著疗效。16例平均随访月龄为3．2±1月,体格发育均正常,B超显示12例脑室形态正常,4例脑室呈稳定的轻度增大。失败的2例初次LP迟,初期LP间隔期延长为7－9d,放液量＜5ml。同期另有17例严重IVH患儿未予LP治疗。其中4例并发脑积水,5例自动出院,4例早期死亡,余4例其后脑室形态稳定。结论连续LP不失为治疗新生儿严重IVH实用安全有效的方法,LP疗效欠佳时可联用乙酰唑胺治疗。