Central venous oxygen saturation monitoring: role in adult donor care?

Monitoring oxygen saturation of blood drawn from a catheter placed within the superior vena cava (Scvo2) has recently been promoted as a substitute for evaluating oxygen saturation of mixed venous blood drawn from the pulmonary artery (Svo2). The Svo2 reflects the balance between oxygen delivery and oxygen consumption throughout the body and, among critically ill patients, may be helpful for assessing resuscitation, cardiac function, or oxygen homeostasis end points. Use of Scvo2 instead has been promoted because of its easier access and recent use during resuscitation of patients with severe infections. Although data from healthy subjects and critically ill patients are available, no study has been done among organ donors to evaluate customary values for either Scvo2 or Svo2 or how well the values correspond. After loss of oxygen consumption in the brain following brain death, the customary values for these variables may be different from values in other groups of patients. Therefore, until donor-specific normative values for these important parameters are identified, we do not recommend that Scvo2 be used to evaluate the balance between donor oxygen consumption and delivery or as a variable to guide treatment.     

Role of Estrogen in Regulation of Morphology and Synaptic Connectivity in Female Rat Subiculum

Estrogen is reported to exert neuroprotective influences on the cornu ammonis as well as the dentate gyrus, two of the three components of the hippocampal memory system. Subiculum, the third and the output component of this system, plays a vital role in retrieval of previously learnt information (recall tasks). We undertook these studies to understand estrogen's role in regulating the synaptic connectivity, neurotransmission and neural degeneration in subiculum. For this, we used brains of aged (16–18 months) post-estropausal female Wistar rats, and compared them with those of adult (4–5 months) ovary-intact, ovariectomized, ova riectomized-vehicle treated and ova riectomized-estrogen treated rats. The vehicle (sesame oil) and estrogen therapy. (17β estradiol, E2) were administered as daily subcutaneous injections (0.1 mg/kg of E2 in 0.1 ml vehicle) for 30 days. Serum estradiol assay was done to determine the levels of circulating serum estradiol levels. Brains were processed for Cresyl Violet, Golgi staining and Immunohistochemical studies [using anti-synaptophysin antibody].Our results indicate that estrogen deficiency (induced by normal ageing or by ovariectomy) results in subicular neuronal degenerative changes, decreased synaptic connectivity and reduced dendritic arborization, most of which are reasonably reversed with estrogen replenishment. These studies suggest a unique role of estrogen in preventing and even reversing the senile neurodegenerative changes in female subiculum.     

Dengue hemorrhagic fever: a rare cause of pituitary tumor hemorrhage and reversible vision loss

Dengue hemorrhagic fever leading to hemorrhage in pituitary adenoma is not reported till date: We herein report the first case of bilateral visual loss secondary to pituitary adenoma hemorrhage associated with dengue hemorrhagic fever. Urgent transnasal trans sphenoidal decompression of the macroadenoma prevented permanent visual loss in this patient. Pituitary apoplexy should be considered as differential diagnosis of visual deterioration apart from retinal hemorrhage, maculopathy, and optic neuropathy in cases of dengue hemorrhagic fever. Early decompression of optic nerves helped in the restoration of vision.     

Role of color Doppler indices in predicting disease-free survival of breast cancer patients during neoadjuvant chemotherapy

The aim of our study was to evaluate whether blood flow in locally advanced and inflammatory breast cancer before and after neoadjuvant chemotherapy using color Doppler ultrasonography can be used to monitor the response to therapy and identify possible correlations between survival and various Doppler indices. Fifty patients with breast cancer underwent Doppler evaluation of the tumor with determination of Doppler indices such as pulsatility index (PI), resistive index (RI), and peak systolic velocity (PSV). RI and PI decreased in 27 (54%) and 20 (40%) patients, respectively, and increased in 23 (46%) and 30 (60%) patients, respectively. Thirty (60%) patients showed a decrease in PSV and 20 (40%) patients an increase. Patients with an intratumoral blood flow velocity increase after chemotherapy had a greater likelihood of local recurrence and metastasis compared with patients in whom flow velocity decreased after chemotherapy. The study also confirmed a greater correlation between Doppler PSV and clinical assessment. Tumor flow velocity measured by Doppler ultrasound can be used as an independent marker of disease-free survival in patients with breast cancer.