Connectomic assessment of injury burden and longitudinal structural network alterations in moderate‐to‐severe traumatic brain injury

Traumatic brain injury (TBI) is a major public health problem. Caused by external mechanical forces, a major characteristic of TBI is the shearing of axons across the white matter, which causes structural connectivity disruptions between brain regions. This diffuse injury leads to cognitive deficits, frequently requiring rehabilitation. Heterogeneity is another characteristic of TBI as severity and cognitive sequelae of the disease have a wide variation across patients, posing a big challenge for treatment. Thus, measures assessing network‐wide structural connectivity disruptions in TBI are necessary to quantify injury burden of individuals, which would help in achieving personalized treatment, patient monitoring, and rehabilitation planning. Despite TBI being a disconnectivity syndrome, connectomic assessment of structural disconnectivity has been relatively limited. In this study, we propose a novel connectomic measure that we call network normality score (NNS) to capture the integrity of structural connectivity in TBI patients by leveraging two major characteristics of the disease: diffuseness of axonal injury and heterogeneity of the disease. Over a longitudinal cohort of moderate‐to‐severe TBI patients, we demonstrate that structural network topology of patients is more heterogeneous and significantly different than that of healthy controls at 3 months postinjury, where dissimilarity further increases up to 12 months. We also show that NNS captures injury burden as quantified by posttraumatic amnesia and that alterations in the structural brain network is not related to cognitive recovery. Finally, we compare NNS to major graph theory measures used in TBI literature and demonstrate the superiority of NNS in characterizing the disease.     

Controlled ovarian hyperstimulation: are we monitoring the appropriate sex-steroid hormones?

We prospectively evaluated the behavior of serum 17-hydroxyprogesterone (17-OHP), sex-steroid hormones, and C-reactive protein (CRP) levels in 27 patients during controlled ovarian hyperstimulation (COH) for in vitro fertilization (IVF). While routine measurement of COH via serum 17-OHP may replace estradiol (E(2)) and progesterone levels, additional studies are needed to elucidate the ceiling level of serum 17-OHP beyond which intervention is required to prevent severe ovarian hyperstimulation syndrome.     

Experimentelle Forschung

Ohne Zusammenfassung     

Gehirn,Nerven

Ohne Zusammenfassung     

CHEMICAL AND IMMUNOLOGICAL STUDIES ON THE AGENT PRODUCING LEUKOSIS AND SARCOMA OF FOWLS

The activity of the agent producing sarcoma or leukosis in material deposited by high speed centrifugation is the same as that of the original crude extracts. Material sedimentable at high speed containing approximately 10^–5 mg. N produces tumors at the site of injection. Small quantities of material sedimentable at high speed are present in normal chicken sera, and about twice as much in leukemic sera (strain 1). Normal chicken and mouse spleens and all other human and mouse tissues examined contain large amounts of material sedimentable at high speed. Extraction of leukemic blood cells with saline yields little additional virus. The washed cells readily produce leukosis even after irradiation with amounts of x-rays sufficient to destroy the leukemic cells but not the virus. Freezing at –60°C. preserves the activity of the high speed deposits for at least 6 months. Addition of 5 per cent of saturated Na₂SO₄ solution slightly delays deterioration of high speed deposits in the ice box. Most of the agent measured by inoculation of chickens and the fraction sedimentable at high speed measured by its nitrogen content is precipitated by one-third saturation with sodium sulfate.