Factors contributing to the minimum water column stability and timing of the winter turnover in the Ogouchi reservoir.

Turnover in lakes and reservoirs causes circulation in the water column from the bottom to the surface when the water column stability becomes low. Previous studies commonly mentioned that turnover occurs when stratification indices become small, but the threshold is rarely discussed. While turnover phenomena have been extensively studied by evaluating changes in bottom dissolved oxygen (DO), the relationship between the disappearance of hypoxia and water temperature indices has not been determined. This study focused on the factors influencing the minimum thermal gradient (TG) and Schmidt Stability Index (SSI), and the timing of turnover events using DO as an indicator of mixing in the Ogouchi reservoir from 1992 to 2001. The results showed that the occurrence of minimum TG and SSI is mainly driven by inflow retention time and average maximum wind speed. Moreover, minimum air temperature and outflow retention time have few contributions to minimum SSI. It was found that 7 out of 10 years exhibited full winter turnover, while the remaining years showed incomplete mixing with persistent hypoxia at the reservoir bottom. This study identifies four cases based on onset thresholds of 0.0035 °C m-1 for TG and 30 J m-2 for SSI to explain turnover event: Case 1: an ideal state with stratification indices below the threshold, resulting in the disappearance of hypoxia; Case 2: indices above the threshold sustain hypoxia; Case 3: an irregular state where the indices exceed the threshold, yet hypoxia disappears; and Case 4: an unexpected persistence of hypoxia despite being below the threshold. The majority of the years (70 percent) were explained by thresholds. The multiple regression analysis indicated the importance of wind speed on the turnover event. Therefore, the effect of wind shear was analyzed for 30 percent of the years that cannot be explained by thresholds (cases 3 and 4). Case 3 shows turnover occurrence due to strong accumulated wind shear, despite exceeding thresholds. Conversely, Case 4 reveals weak wind shear preventing bottom water upwelling, even below thresholds. In conclusion, the precise TG and SSI thresholds for the onset of turnover event were determined using DO data. The thresholds explained the occurrence and non-occurrence of turnover event in most of the years and wind speed clarified unexplained cases by thresholds. The presented method successfully evaluated the timing of turnover and can be applicable elsewhere.

Spontaneous regression of congenital brain tumors: a report of two cases.

BACKGROUND: Vanishing brain tumor is defined as spontaneously disappearing or decreasing of the initial brain mass volume to ≤ 70% before establishing the definitive diagnosis. The condition is rare and can be attributed to different factors. The exact mechanism is under debate, but the increasing rate and accuracy of neuroimaging studies and occurrence of similar scenario in other pathologies rather than brain tumors can be of particular importance in finding vanishing brain lesions. CASE REPORT: We present two unusual cases of congenital brain masses which underwent spontaneous shrinkage within the first months of life. CONCLUSION: The condition is scarcely observed in congenital brain masses. As congenital brain lesions are distinct entities with peculiar characteristics, this rare phenomenon may reflect different aspects in this age group.

Isolated primary spinal epidural hydatid cyst in a child with progressive paraparesis.

BACKGROUND: Primary spinal hydatid cyst is a rare but serious condition which occurs in about 1% of patients with hydatid disease. This disease may result in severe spinal cord compression presenting with various neurological deficits. CASE REPORT: A 3-year-old boy was referred to our center with progressive weakness of lower limbs, frequency, and urinary incontinence. His parents did not report back pain during child's illness. Lumbar magnetic resonance imaging (MRI) revealed an extradural well-defined thin-walled cystic lesion at L4 to S3 vertebral levels without enhancement. The cyst had compressed the thecal sac associated with bone scalloping of vertebral bodies and posterior elements. Osteoplastic laminectomy of L4-L5 and laminectomy of S1-S3 was done. Intraoperative and histopathological findings indicated an epidural hydatid cyst. CONCLUSION: Although spinal hydatid cysts are rare but might be considered in the differential diagnosis of any patient with signs and symptoms of spinal cord compression. The pathophysiology, clinical manifestations, epidemiology, diagnosis, and surgical treatment of extradural hydatid cyst are discussed.

Contralateral facial nerve paresis subsequent to posterior fossa meningioma surgery in a child: case report.

INTRODUCTION: Meningiomas are relatively uncommon neoplasms in the pediatric population and posterior fossa is a very rare location for these tumors. Only a few cases of contralateral cranial nerve deficits have been reported but no cases of pediatric meningioma with contralateral facial nerve paresis have been documented in literature. CEREBELLOPONTINE ANGLE MENINGIOMA WHO CASE REPORT: We present a 4 year old girl with found postoperative contralateral facial nerve paresis. DISCUSSION: The possible pathogenesis and literature review concerning this complication are discussed. The mechanisms leading to this complication could be distortion of brainstem, traction during resection and subsequent compression of brainstem against the contralateral petrous or tentorium.

A prospective study of prenatal ventriculomegaly: natural course, survival, and neurodevelopmental status.

OBJECTIVE: Prenatal ventriculomegaly (VM) is classified as mild, moderate, or severe on the basis of the diameter of the atrium. Neurodevelopmental status in prenatal VM is associated with various factors such as the course of VM, VM type, progression, and associated anomalies. In this study, the authors aimed to evaluate neurodevelopmental outcome in patients with prenatal VM and to detect possible associated risk factors. METHODS: In this study, 73 pregnancies with VM who were referred to Children's Medical Center, Tehran, Iran, between 2019 and 2021 were prospectively followed. They were followed up every 2-4 weeks with ultrasonography (US) before delivery and were then observed for an average time of 14.6 months. The authors collected demographic and ultrasound information, associated abnormalities, pregnancy outcomes, and developmental status according to Centers for Disease Control criteria. RESULTS: The mean gestational age at the time of diagnosis was 28.1 weeks, and 46.6% of fetuses were female. According to the first US, 46.6% had mild, 21.9% had moderate, and 31.5% had severe VM. Serial US scans showed that VM had regressed in 20.5% of patients, remained stable in 35.6%, and progressed in 43.8%. Other cranial abnormalities were detected in 38.4% of fetuses. During follow-up, 62.5% of cases had normal developmental status, 26.6% had mild delay, and 10.9% had severe neurodevelopmental delay. Pregnancy was terminated in 9 (12.3%) cases. Normal neurodevelopment was reported in 75.8% of patients with mild VM versus 50% of those with severe VM (p = 0.19). Neurodevelopmental status was normal in 72.5% of cases without other cranial abnormalities (p = 0.018) and in 86.7% of cases with regression of VM (p = 0.028). CONCLUSIONS: Despite analysis of different factors in prenatal VM, only progression of VM and associated cranial abnormalities had significant relationships with neurodevelopmental prognosis.

Prenatal ventriculomegaly: natural course, survival, and neurodevelopmental status.

OBJECTIVE: Prenatal ventriculomegaly is classified as mild, moderate, or severe based on the atrium diameter. The natural course and intrauterine progression of mild and moderate ventriculomegaly associated with the neurodevelopmental status of these children has been widely reported. METHODS: One hundred twenty-two pregnancies with mild and moderate ventriculomegaly referred to the pediatric neurosurgery clinic of Children's Medical Center between 2010 and 2018 were retrospectively studied. The authors collected demographic and first and sequential ultrasonographic information, associated abnormalities, information about pregnancy outcomes, and the latest developmental status of these children according to Centers for Disease Control and Prevention criteria by calling parents at least 1 year after birth. RESULTS: The mean gestational age at the time of diagnosis was 29.1 weeks, and 53% of fetuses were female. The width of the atrium was registered precisely in 106 cases, in which 61% had mild and 39% had moderate ventriculomegaly. Information on serial ultrasound scans was collected in 84 cases in which ventriculomegaly regressed in 5, remained stable in 67, and progressed in 12 patients. Fourteen cases (29.7%) in the mild ventriculomegaly group and 6 cases (16.2%) in the moderate group had associated abnormalities, with corpus callosum agenesis as the most frequent abnormality. The survival rate was 80% in mild and 89.4% in moderate ventriculomegaly. Considering survival to live birth and progression of the ventriculomegaly, the survival rate was 100% in regressed, 97% in stable, and 41.6% in progressed ventricular width groups (p < 0.001). Neurodevelopmental status was evaluated in 73 cases and found to be normal in 69.8% of the cases; 16.4% of children had mild delay, and 5.4% and 8.2% of cases were diagnosed with moderate and severe delays, respectively. CONCLUSIONS: In spite of a high rate of missed data in our retrospective study, most patients with mild or moderate ventriculomegaly had a stable or regressed course. Most cases had near-normal developmental status. Prospective studies with a larger sample size and detailed developmental evaluation tests are needed to answer the questions related to the natural course, survival, and prognosis of prenatal ventriculomegaly.

The data set development for the National Spinal Cord Injury Registry of Iran (NSCIR-IR): progress toward improving the quality of care.

STUDY DESIGN: Descriptive study. OBJECTIVES: The aim of this manuscript is to describe the development process of the data set for the National Spinal Cord Injury Registry of Iran (NSCIR-IR). SETTING: SCI community in Iran. METHODS: The NSCIR-IR data set was developed in 8 months, from March 2015 to October 2015. An expert panel of 14 members was formed. After a review of data sets of similar registries in developed countries, the selection and modification of the basic framework were performed over 16 meetings, based on the objectives and feasibility of the registry. RESULTS: The final version of the data set was composed of 376 data elements including sociodemographic, hospital admission, injury incidence, prehospital procedures, emergency department visit, medical history, vertebral injury, spinal cord injury details, interventions, complications, and discharge data. It also includes 163 components of the International Standards for the Neurologic Classification of Spinal Cord Injury (ISNCSCI) and 65 data elements related to quality of life, pressure ulcers, pain, and spasticity. CONCLUSION: The NSCIR-IR data set was developed in order to meet the quality improvement objectives of the registry. The process was centered around choosing the data elements assessing care provided to individuals in the acute and chronic phases of SCI in hospital settings. The International Spinal Cord Injury Data Set was selected as a basic framework, helped by comparison with data from other countries. Expert panel modifications facilitated the implementation of the registry process with the current clinical workflow in hospitals.

White Matter Tract Alterations in Drug-Naïve Parkinson's Disease Patients With Excessive Daytime Sleepiness.

Excessive daytime sleepiness (EDS) is relatively frequent in patients with Parkinson's disease (PD), having a prominent burden on patients' quality of life and causing dangerous events such as motor-vehicle accidents. Previous studies have indicated the role of certain neural tracts in the pathophysiology of sleep disturbances, especially in PD patients. We hypothesized that white matter integrity and connectivity might be altered in patients with PD and EDS. Therefore, this study investigated brain white matter microstructure alterations in patients with Parkinson's disease with EDS (PD-EDS) compared to healthy controls and PD patients without EDS (PD-nEDS). Diffusion MRI connectometry was used to carry out group analysis between PD patients with and without EDS and healthy individuals. EDS in PD patients is associated with decreased connectivity in the left and right fornix, left and right inferior longitudinal fasciculus (ILF), left inferior and middle cerebellar peduncles in comparison to PD-nEDS group. These differences between PD-EDS and PD-nEDS patients reflects microstructural changes with respect to sleep-related circuits, which can pave the way for future investigations considering EDS pathogenesis in Parkinson's disease.

Role of p38/MAPKs in Alzheimer's disease: implications for amyloid beta toxicity targeted therapy.

A myriad of environmental and genetic factors, as well as the physiologic process of aging, contribute to Alzheimer's disease (AD) pathology. Neuroinflammation is and has been a focus of interest, as a common gateway for initiation of many of the underlying pathologies of AD. Amyloid beta (Aß) toxicity, increasing RAGE expression, tau hyperphosphorylation, induction of apoptosis, and deregulated autophagy are among other mechanisms, partly entangled and being explained by activation of mitogen-activated protein kinase (MAPK) and MAPK signaling. p38 MAPK is the most essential regulator of Aß induced toxicity from this family. p38 induces NF-κB activation, glutamate excitotoxicity, and disruption of synaptic plasticity, which are other implications of all justifying the p38 MAPK as a potential target to break the vicious Aß toxicity cycle. Until recently, many in vivo and in vitro studies have investigated the effects of p38 MAPK inhibitors in AD. The pyridinyl imidazole compounds SB202190 and SB203580 have shown promising anti-apoptotic results in vivo. MW108 inhibits activation of p38 and is able to postpone cognitive decline in animal models. The PD169316, with anti-inflammatory, anti-oxidative, and anti-apoptotic features, has improved spatial memory in vivo. Natural compounds from Camellia sinensis (green tea), polyphenols from olive oil, pinocembrin from propolis, and the puerarine extract isoflavones, have shown strong anti-apoptotic features, mediated by p38 MAPK inhibition. Use of these drug targets is limited due to central nervous system side effects or cross-reactivity with other kinases, predicting the low efficacy of these drugs in clinical trials.