Beta‐2 transferrin is detectable for 14 days whether refrigerated or stored at room temperature

Background

The effect of time and temperature on beta‐2 transferrin stability in cerebrospinal fluid (CSF) is not well established. After collecting nasal CSF for testing, beta‐2 transferrin has been found to be stable and detectable for 1 week, whether being refrigerated or stored at room temperature. The purpose of this study was to determine if beta‐2 transferrin remained detectable longer than 1 week and whether refrigeration improved its detectability.

Methods

In patients undergoing therapeutic CSF diversion, 2‐mL CSF samples were collected from 18 patients. The samples were divided and stored either at room temperature, or at 4°C, and tested for beta‐2 transferrin at 7 and 14 days. CSF was collected from external ventricular drains (EVDs) (n = 15), lumbar drains (n = 2), and subdural drains (n = 1).

Results

Of the 18 CSF samples originally testing positive for beta‐2 transferrin, none turned negative at 7 or 14 days, in both the refrigerated and room temperature groups (95% confidence interval [CI], 0% to 18.5%).

Conclusion

Beta‐2 transferrin remained detectable for 14 days in all CSF samples, regardless of being stored at 4°C or room temperature.

     

神经外科术后患者静脉输注替考拉宁脑脊液药物浓度研究

目的了解神经外科术后患者静脉输注替考拉宁时脑脊液药物浓度,探讨神经外科手术破坏血脑屏障后是否可增加脑脊液药物浓度,以及药物持续泵入对脑脊液药物浓度的影响。方法选择神经外科术后留置术区/脑室引流管的患者,分为常规给药组(替考拉宁400 mg,30 min泵入,1次/12 h重复给药)和持续给药组(替考拉宁400 mg,30 min泵入,再以200 mg,1次/6 h持续泵入),于给药后相应时间点采集脑脊液标本检测替考拉宁浓度。结果常规给药组脑脊液替考拉宁浓度泵入后即刻浓度为(0.004±0.0123)mg/L,泵入后1 h达峰值(0.712±1.028)mg/L,后逐渐下降,泵入后12、18、24 h分别为(0.254±0.222)、(0.173±0.152)、(0.355±0.207)mg/L。持续给药组脑脊液替考拉宁泵入后即刻浓度为(0.017±0.020)mg/L,4 h后达峰值(0.587±0.255)mg/L,泵入后6、12、18、24 h分别为(0.429±0.416)、(0.325±0.254)、(0.476±0.686)、(0.318±0.464)mg/L,6 h后药物浓度相对稳定,介于(0.318±0.464)~(0.476±0.686)mg/L。常规给药组、持续给药组的AUC0—24 h分别为5.590 mg/L·h、9.082 mg/L·h。两组患者仅峰值附近区域替考拉宁浓度达到凝固酶阴性葡萄球菌(CNS)MIC50,但其浓度高于CNS MIC50的时间占整个给药时间的比例远小于50%;两组患者脑脊液替考拉宁浓度均未能达到金黄色葡萄球菌MIC50。结论持续输注替考拉宁后,患者脑脊液药物浓度较常规给药组有所增加,但仍未能达所要求的MIC;结合血药浓度的实验,血液浓度增高有利于脑脊液药物浓度增加,可考虑适当增加剂量以达到临床治疗目的。     

A comparison of spontaneous and CSF added CFU-MG colony formation in healthy,sick and hypotrophic pre-term infants

Summary Myelopoietic progenitor cells (CFU-MG) have been studied from peripheral blood of healthy, sick, and hypotrophic pre-term infants. Methylcellulose cultures were prepared simultaneously with and without exogenous colony stimulating factor. It was found that large numbers of circulating CFU-M are present at birth in healthy infants, smaller numbers in sick infants, and very few in hypotrophic infants. Exogenous CSF increases the number of colonies in cultures of healthy infants at birth. A limiting factor in spontaneous colony formation is the production of CSF by the cells in culture. This is particularly evident in sick infants. During the postnatal course similar levels of circulating CFUc, higher than in adult blood, are found in all three groups of pre-term infants.Supported by grants from the Deutsche Forschungsgemeinschaft (Pr 75/8) and from the Niedersächsisches Ministerium für Wissenschaft und Kunst     

Predictors of thermal response and lesion size in patients undergoing magnetic resonance-guided focused ultrasound thalamotomy

Magnetic resonance-guided focused ultrasound (MRgFUS) is being increasingly utilized in the treatment of movement disorders such as essential tremor (ET) and Parkinson’s disease (PD). Whilst skull density ratio (SDR) has previously been correlated with achieving lesional temperature rises, other patient factors such as brain and cerebrospinal fluid (CSF) volume have not previously been investigated. We aimed to investigate the effect of brain and CSF volumes on lesional temperature rises, as well as the effect of brain and CSF volumes and SDR on post-treatment lesion sizes. Fifty-four consecutive patients were studied with patient and treatment-related variables collected along with post-treatment lesion sizes. Linear regression analysis identified that SDR alone was associated with lesional temperatures. Both SDR and brain atrophy were associated with post-treatment lesion sizes on linear regression analysis. On multiple linear regression analysis SDR was significantly associated with post-treatment lesion size, and the association between brain atrophy and lesion sizes approached significance, a finding that warrants further investigation.     

Non-invasive assessment of cerebrospinal fluid flow dynamics using phase-contrast magnetic resonance imaging in communicating hydrocephalus

This work aims to evaluate the changes in cerebrospinal fluid (CSF) hydrodynamics in patients diagnosed with communicating hydrocephalus. Besides, we establish the relationship between CSF flow dynamic parameters on the midbrain aqueduct and intracranial pressure (ICP). CSF hydrodynamics analysis was performed using Phase-Contrast Magnetic Resonance Imaging (PC‐MRI) techniques on the midbrain aqueduct of 41 patients diagnosed with communicating hydrocephalus and 22 healthy volunteers. The correlation between CSF average flow in the midbrain aqueduct and intracranial pressure measured by Lumbar Puncture (LP) was assessed in patients with hydrocephalus. Pearson correlation coefficient was used to establish the correction between the average CSF flow of midbrain aqueduct and ICP. CSF dynamic parameters of the midbrain aqueduct in hydrocephalus patients, including peak positive velocity (7.348 cm/s), average velocity (0.623 cm/s), average flow (50.799 mm³/s), and regions of interest (ROI) area (9.978 mm²) were significantly higher than in the healthy controls (p < 0.05). This was after adjusting the age, gender, heart rate, systolic blood pressure, diastolic blood pressure, and body mass index. However, only the peak negative velocity of the midbrain aqueduct did not significantly differ between the groups (p = 0.209). A positive correlation was noted between the average flow (AF) of the midbrain aqueducts and ICP in hydrocephalus patients (y (AF) = 0.386× (ICP)−33.738, r = 0.787, p < 0.05). Reference data of CSF flow dynamic parameters was obtained through the PC-MRI in middle-aged healthy volunteers and communicating hydrocephalus patients. Although the sample size was constrained, this study has significant contributions. For instance, a significant correlation was noted between the average CSF flow of the aqueduct and ICP. This therefore provides a reference for clinicians to monitor ICP in patients with hydrocephalus.