Detecting a Defective Casing Seal at the Top of a Bedrock Aquifer.

An improperly sealed casing can produce a direct hydraulic connection between two or more originally isolated aquifers with important consequences regarding groundwater quantity and quality. A recent study by Richard et al. (2014) investigated a monitoring well installed in a fractured rock aquifer with a defective casing seal at the soil-bedrock interface. A hydraulic short circuit was detected that produced some leakage between the rock and the overlying deposits. A falling-head permeability test performed in this well showed that the usual method of data interpretation is not valid in this particular case due to the presence of a piezometric error. This error is the direct result of the preferential flow originating from the hydraulic short circuit and the subsequent re-equilibration of the piezometric levels of both aquifers in the vicinity of the inlet and the outlet of the defective seal. Numerical simulations of groundwater circulation around the well support the observed impact of the hydraulic short circuit on the results of the falling-head permeability test. These observations demonstrate that a properly designed falling-head permeability test may be useful in the detection of defective casing seals.

Disease severity and treatment in adolescent idiopathic scoliosis: the impact of race and economic status.

BACKGROUND CONTEXT: Ethnic disparities have been documented in the incidence and treatment of many diseases. Additionally, race and socioeconomic status (SES) have been shown to affect disease severity and access to care in the recent orthopedic literature. PURPOSE: To assess the role, if any, that race, SES, and health insurance type play in disease severity and treatment decisions in patients with adolescent idiopathic scoliosis. STUDY DESIGN: Retrospective chart review. PATIENT SAMPLE: Pediatric patients seen in a single surgeon's practice over 6 years (2004-2009). OUTCOME MEASURES: Treatment modality (observation, bracing, or surgery). METHODS: Data were obtained from 403 patients seen over 6 years (2004-2009). A patient-reported questionnaire was used to collect race, age, family income, and parent marital status data. Race was self-reported as "Asian," "black or African American," "Hispanic or Latino," "white or Caucasian," or "Other." Socioeconomic status was determined using family income and type of health insurance as indicators. Major curve magnitude and prescribed initial treatment (observation, brace, or surgery) were assessed from physician records. An independent sample t test was used to detect differences in curve magnitude of the different racial groups. A Pearson chi-square analysis was used to detect group differences for curves in surgical patients, defined as curves greater than 40°, and their initial treatment. RESULTS: Patients self-identified with one of the following racial groups: white (N=219), black (N=86), Hispanic (N=44), Asian (N=37), or Other (N=17). Mean curve magnitude was greater in black than in white patients (33° vs. 28°, p<.05). Black patients were more likely to present with curves in the surgical range (34% vs. 24%, p<.05) and were more likely to have surgery as their initial treatment than white patients (34% vs. 19%, p<.05). Black patients had more limited health care plans and lower incomes compared with whites (p<.001). Patients with higher access insurance plans presented at a younger age than patients with more limited access plans, irrespective of race (13.6 vs. 14.1, p<.05). There was no difference in Cobb angle at presentation by income or type of insurance. CONCLUSIONS: Curve magnitude and percentage of patients with curves in the surgical range were greater in black than in white patients. There was no difference in age on presentation or treatment offered across all racial groups. Black patients were more likely to have surgery as their initial treatment than white patients. While race did have an impact on disease severity in this single surgeon's practice, SES did not.

Triple positivity of HBsAg, anti-HCV antibody, and HIV and their influence on CD4+ lymphocyte levels in the highly HIV infected population of Abeokuta, Nigeria.

BACKGROUND: Few studies exist on hospital-based seroprevalence of triple positivity of HIV/HBV/HCV in Nigeria. OBJECTIVES: The study aimed at determining the triple positivity of HIV, HBsAg and HCV among HIV-infected individuals in Abeokuta, Nigeria and defining the influence of these triple infections on CD4+ counts of HIV-infected individuals as antiretroviral therapy improves in Nigeria. METHODS: Enumeration of CD4+ levels in 183 HIV-infected persons was done with Partec Flow Cytometer. Seropositivity of HBsAg and anti-HCV antibody was detected with rapid kits. RESULTS: From the result obtained, significance variance (p<0.05) existed between HIV positive persons and persons who tested positive to HIV/HBV/HCV triple infection before and after the commencement of HAART. Of these infections, 31(16.9%) had HBV/HCV/HIV triple infection, while 152(83.1%) had HIV mono infection only, 56(30.6%) had HBV/HIV dual infection only and 43(23.5%) had HCV/HIV dual infection only. Significant variance (p<0.05) also existed between subjects with CD4 counts of <200 cells/µl, 200-499 cells/µl and >500 cells/µl. Highest seroprevalence of HIV (35.0%) was found in age groups 35-44 years and >65 years had the least (2.7%). Significant variance (p<0.05) also existed in the progression of CD4+ lymphocytes cells between subjects with persistent decrease (32.3%) in CD4+ lymphocytes cells and those with fluctuation in their CD4+ lymphocytes cells (12.9%) after the commencement of ART. CONCLUSION: The study further confirms that triple positivity of HIV/HBV/HCV infection is common in Abeokuta, Nigeria. Testing of these triple infections should be a big concern in the best choice and commencement of ART. Also, the study showed that consistent and prolonged use of HAART had a positive impact on the CD4 count of HIV-infected individuals.

Effects of the noradrenergic system in rat white matter exposed to oxygen-glucose deprivation in vitro.

Norepinephrine (NE) is released in excess into the extracellular space during oxygen-glucose deprivation (OGD) in brain, increasing neuronal metabolism and aggravating glutamate excitoxicity. We used isolated rat optic nerve and spinal cord dorsal columns to determine whether the noradrenergic system influences axonal damage in white matter. Tissue was studied electrophysiologically by recording the compound action potential (CAP) before and after exposure to 60 min of OGD at 36 degrees C. Depleting catecholamine stores with reserpine was protective and improved CAP recovery after 1 h of reperfusion from 17% (control) to 35%. Adding NE during OGD decreased CAP recovery to 8%, and adding NE to reserpine during OGD eliminated the protective effect of the latter. Selective inhibitors of Na(+)-dependent norepinephrine transport desipramine and nisoxetine improved recovery to 58% and 44%, respectively. alpha2 adrenergic receptor agonists UK14,304 and medetomidine improved CAP recovery to 41% and 46% after 1 h of OGD. Curiously, alpha2 antagonists alone were also highly protective (e.g., atipamezole: 86% CAP recovery), at concentrations that did not affect baseline excitability. The protective effect of alpha2 receptor modulation was corroborated by imaging fluorescent Ca(2+) and Na(+) indicators within axons during OGD. Both agonists and antagonists significantly reduced axonal Ca(2+) and Na(+) accumulation in injured axons. These data suggest that the noradrenergic system plays an active role in the pathophysiology of axonal ischemia and that alpha2 receptor modulation may be useful against white matter injury.

Chemical anatomy of the human ventral striatum and adjacent basal forebrain structures.

Calbindin D-28k (CB), calretinin (CR), substance P (SP), limbic system-associated membrane protein (LAMP), choline acetyltransferase (ChAT), and acetylcholinesterase (AChE) were used as chemical markers to investigate the organization of the ventral striatum (VST) and adjacent structures in healthy human individuals. No clear boundary could be established between the dorsal striatum and the VST, and the core/shell subdivisions of nucleus accumbens (Acb) could be distinguished only at the midrostrocaudal level of the VST. The CB-poor shell displayed intense immunostaining for SP and CR but only weak staining for LAMP. By contrast, the core was weakly stained for SP and CR and moderately stained for LAMP and CB. There was no difference between shell and core with regard to the cholinergic markers. The Acb harbored numerous ChAT- and CR-immunoreactive cell bodies, the latter being distributed according to a marked, mediolaterally increasing gradient. The size of the ChAT- and CR-immunoreactive perikarya in the Acb varied according to their location in the core and shell. The VST was surrounded by a chemically heterogeneous group of cell clusters referred to as interface islands. The CR-rich caudal portion of the VST merged with the bed nucleus of the stria terminalis dorsally and the diagonal band of Broca ventromedially, the latter two structures displaying complex immunostaining patterns. The claustrum was markedly enriched in LAMP and harbored different types of CR- and CB-immunopositive neurons. These results demonstrate that the neurochemical organization of the human VST is strikingly complex and exhibits a greater heterogeneity than the dorsal striatum.