GnRH agonist-associated pituitary apoplexy: a case series and review of the literature.

PURPOSE: To examine the clinical presentation and longitudinal outcome of Pituitary Apoplexy (PA) after gonadotropin-releasing hormone agonist (GnRHa) in a series of patients and compare to prior reports. METHODS: A retrospective chart review was performed on seven patients receiving GnRHa who developed PA. Prior reported cases were analyzed. RESULTS: Six men (median age 72 years) with prostate cancer and one woman (aged 22 years) undergoing oocyte donation presented with PA between 1990 and 2020. Most presented with within 24 h of the first dose, but two developed PA 1 to 5 months after GnRHa initiation. The main clinical manifestations were headache (100%), nausea and vomiting (86%). While no patients had a previously known pituitary tumor, all had imaging demonstrating sellar mass and/or hemorrhage at presentation. Among those surgically treated (5/7), 80% (4/5) of patients had pathologic specimens that stained positive for gonadotropins; the remaining patient's pathologic specimen was necrotic. At the time of PA, the most common pituitary dysfunction was hypocortisolism. Central adrenal insufficiency and central hypothyroidism were reversible in a subset. Pituitary imaging remained stable. CONCLUSIONS: This is the first report of a case series with PA after GnRHa administration with longitudinal follow-up. Although infrequent, PA can be life-threatening and should be suspected among patients receiving GnRHa, with or without a known pituitary adenoma, who develop acute headache, nausea and/or vomiting. Since hypopituitarism was reversible in a subset, ongoing pituitary function testing may be indicated.

Risk Factors for Retinal Detachment: A Case-Control Study.

OBJECTIVE: The aim of this study was to investigate risk factors for retinal detachment or tear (RD/T), and follow up two studies that found increased risk from work-related heavy lifting. METHODS: We conducted a case-control study including 200 cases of RD/T and 415 controls. Participants completed a questionnaire covering general health, vision, and physical exertion. Multiple logistic regression and propensity score matching was used to control confounding and estimate independent effects. RESULTS: RD/T risk was increased by one lifting measure: current regular lifting of more than 30 lbs (>13.6 kg). In the population aged less than 65 years, the odds ratio comparing those with/without heavy lifting was 1.81, 95% confidence interval = 1.08 to 3.04. CONCLUSION: Occupational heavy lifting may represent a risk factor for RD/T, but further research is needed in populations with frequent heavy physical exertion to more precisely quantify the risk.

Oxygen isotope ratios in primate bone carbonate reflect amount of leaves and vertical stratification in the diet.

The stable isotopic biogeochemistry of free-ranging primates is a unique tool to assess dietary and ecological adaptions among sympatric populations. The present study tested the hypothesis that oxygen isotopes in the bone carbonate of five primate and four ungulate species that live in Kibale National Park, Uganda, would show minimal variability since the species obtain water from a single water source. Bones were analyzed for stable carbon (δ(13) C) and oxygen (δ(18) O) isotope ratios. Results for apatite δ(13) C are consistent with all species feeding in a closed forest habitat and do not exhibit niche partitioning. δ(18) O values, in contrast, cluster by species and correlate positively with the relative contribution of leaves to the whole diet are likely also modified by vertical niche partitioning between taxa within the forest canopy. These results show that biochemical markers from naturally deceased primate remains can aid our understanding of how living animals exploit available resources. Am. J. Primatol. 78:1086-1097, 2016 © 2015 Wiley Periodicals, Inc.

Fe(II) uptake on natural montmorillonites. II. Surface complexation modeling.

Fe(II) sorption edges and isotherms have been measured on low structural Fe-content montmorillonite (STx) and high structural Fe-content montmorillonite (SWy) under anoxic (O2 < 0.1 ppm) and strongly reducing conditions (Eh = -0.64 V). Under anoxic conditions Fe(II) sorption on SWy was significantly higher than on STx, whereas the sorption under reducing conditions was essentially the same. The uptake behavior of Fe(II) on STx under all redox conditions (Eh = +0.28 to -0.64 V) and SWy under reducing conditions (Eh = -0.64 V) was consistent with previous measurements made on other divalent transition metals. All of the sorption data could be modeled with the two-site protolysis nonelectrostatic surface complexation and cation exchange (2SPNE SC/CE) sorption model including an additional surface complexation reaction for Fe(II) which involved the surface oxidation of ferrous iron surface complexes (≡S(S,W)OFe(+)) to ferric iron surface complexes (≡S(S,W)OFe(2+)) on both the strong and weak sites. The electron acceptor sites on the montmorillonite are postulated to be the structural Fe(III).

Fe(II) sorption on a synthetic montmorillonite. A combined macroscopic and spectroscopic study.

Extended X-ray absorption fine structure (EXAFS) and Mössbauer spectroscopy combined with macroscopic sorption experiments were employed to investigate the sorption mechanism of Fe(II) on an iron-free synthetic montmorillonite (Na-IFM). Batch sorption experiments were performed to measure the Fe(II) uptake on Na-IFM at trace concentrations as a function of pH and as a function of sorbate concentration at pH 6.2 and 6.7 under anoxic conditions (O2 < 0.1 ppm). A two-site protolysis nonelectrostatic surface complexation and cation exchange sorption model was used to quantitatively describe the uptake of Fe(II) on Na-IFM. Two types of clay surface binding sites were required to model the Fe(II) sorption, the so-called strong (≡S(S)OH) and weak (≡S(W)OH) sites. EXAFS data show spectroscopic differences between Fe sorbed at low and medium absorber concentrations that were chosen to be characteristic for sorption on strong and weak sites, respectively. Data analysis indicates that Fe is located in the continuity of the octahedral sheet at trans-symmetric sites. Mössbauer spectroscopy measurements confirmed that iron sorbed on the weak edge sites is predominantly present as Fe(II), whereas a significant part of surface-bound Fe(III) was produced on the strong sites (∼12% vs ∼37% Fe(III) species to total sorbed Fe).

Molecular modeling and functional confirmation of a predicted fatty acid binding site of mitochondrial aspartate aminotransferase.

Molecular interactions are necessary for proteins to perform their functions. The identification of a putative plasma membrane fatty acid transporter as mitochondrial aspartate aminotransferase (mAsp-AT) indicated that the protein must have a fatty acid binding site. Molecular modeling suggests that such a site exists in the form of a 500-Å(3) hydrophobic cleft on the surface of the molecule and identifies specific amino acid residues that are likely to be important for binding. The modeling and comparison with the cytosolic isoform indicated that two residues (Arg201 and Ala219) were likely to be important to the structure and function of the binding site. These residues were mutated to determine if they were essential to that function. Expression constructs with wild-type or mutated cDNAs were produced for bacteria and eukaryotic cells. Proteins expressed in Escherichia coli were tested for oleate binding affinity, which was decreased in the mutant proteins. 3T3 fibroblasts were transfected with expression constructs for both normal and mutated forms. Plasma membrane expression was documented by indirect immunofluorescence before [(3)H]oleic acid uptake kinetics were assayed. The V(max) for uptake was significantly increased by overexpression of the wild-type protein but changed little after transfection with mutated proteins, despite their presence on the plasma membrane. The hydrophobic cleft in mAsp-AT can serve as a fatty acid binding site. Specific residues are essential for normal fatty acid binding, without which fatty acid uptake is compromised. These results confirm the function of this protein as a fatty acid binding protein.

A spectroscopic characterization and quantification of m(III)/clay mineral outer-sphere complexes.

For the long-term safety assessment of deep radioactive waste repositories an understanding of the interactions of actinides with mineral surfaces at a molecular level is necessary. The retention/mobility of the released radionuclides is strongly dependent on sorption/desorption reactions at mineral surfaces. Thus, a quantitative understanding of the uptake mechanisms of actinides on clay minerals will make an important contribution to long-term safety assessments. Using time-resolved laser fluorescence spectroscopy (TRLFS), it was possible to differentiate between nonsorbed aquo ions and outer-sphere sorbed Cm(III) onto different montmorillonites. In addition, Cm(III)/clay outer-sphere complexation at different ionic strengths using NaCI as the background electrolyte is quantified. Finally, the results are verified by sorption model calculations.

Diffusion of 22Na and 85Sr in montmorillonite: evidence of interlayer diffusion being the dominant pathway at high compaction.

A mechanistic understanding of transport phenomena in compacted clays is essential for the use of such materials as engineered barrier systems for the safe geological disposal of radioactive wastes. The present contribution is a first step in the development of an integrative treatment of the properties of tracer cations in compacted bentonites with respect to diffusion and sorption. The diffusion of 22Na and 85Sr in highly compacted montmorillonite and kaolinite is investigated as a function of the "external salt concentration" (NaClO4), i.e., of the solution in equilibrium with the clay. Consistent results were obtained from through-diffusion experiments and tracer profile analysis. Knowledge of genuine diffusion coefficients of the filter plates turned out to be crucial in cases where the diffusive resistance of the filter plates was similar to that of the clay. Diffusion coefficients formally calculated on the basis of the tracer concentration gradient in the external aqueous phase, and the sorption distribution ratios were found to decrease with increasing external salt concentration in the case of montmorillonite. In a logarithmic representation of these data, a slope of -1 was obtained for the monovalent 22Na, whereas the slope was -2 for the divalent 85Sr. In the case of kaolinite, diffusion coefficients were independent of the external salt concentration. It is postulated that the diffusion of the tracer cation through the interlayer water is the dominant pathway in compacted swelling clays under the experimental conditions tested. Effective diffusion coefficients, based on a tracer concentration gradient in the interlayer water of the clay, were found to be independent of the composition of the external aqueous phase. The latter gradient is assumed to be a function of the external salt concentration, according to a calculated distribution of the tracer cation between free pore water and the interlayer water via cation exchange.

Lipid metabolism and liver inflammation. I. Hepatic fatty acid uptake: possible role in steatosis.

Hepatic steatosis is a growing public health concern. Nonalcoholic fatty liver is increasingly common in Western societies and may lead to steatohepatitis, fibrosis, and cirrhosis, possibly triggered by lipid peroxidation. The relation of fatty liver to obesity, type II diabetes, and/or metabolic syndrome is significant. One aspect these related disorders share is increased serum-free fatty acids, which may be taken up by hepatocytes. Uptake of fatty acids in excess of metabolic requirements will lead to storage as triglycerides, resulting in steatosis and providing substrate for lipid peroxidation. Fatty acid uptake may be crucial to understanding steatosis.

Association between mild vascular cognitive impairment and impaired activities of daily living in older stroke survivors without dementia.

OBJECTIVES: To determine the relationship between mild vascular cognitive impairment (mVCI) and functional disability in older stroke survivors without dementia. DESIGN: Cohort study. SETTING: Stroke patients from representative hospital-based stroke registers. PARTICIPANTS: Three hundred thirty-nine stroke survivors without dementia, aged 75 and older. MEASUREMENTS: Neuropsychological assessments were completed 3 months poststroke. Activities of daily living (ADLs) were evaluated using the Bristol scale. Operationalized criteria, including cognitive impairment no dementia (CIND), were applied for mVCI. RESULTS: Significant impairments of ADLs were evident in mVCI (CIND vs no CIND; basic care: z=3.2; P=.001, intermediate care: z=3.6; P<.001, complex management: z=4.5; P<.001) but varied according to the profile of cognitive impairments. Patients with attentional or global impairments had more severe functional disability than patients with isolated memory deficits, with an intermediate level of dysfunction in patients with executive impairments. CONCLUSION: The findings emphasize the importance of identifying early cognitive impairments to optimize rehabilitation, care planning, and secondary prevention of dementia in stroke patients.

Increased hepatocellular uptake of long chain fatty acids occurs by different mechanisms in fatty livers due to obesity or excess ethanol use, contributing to development of steatohepatitis in both settings.

Long chain fatty acids (LCFA) enter cells by both facilitated transport and diffusion, the former accounting for > or = 90%. Facilitated LCFA transport is up-regulated in adipocytes from obese rats, mice, and humans. To clarify the role of hepatocellular LCFA uptake in hepatic steatosis (fatty liver), [3H]-oleic acid (OA) uptake was studied in hepatocytes isolated from Zucker fatty(Z) and control(C) and ethanol-fed(E) Wistar rats, and demonstrated both saturable and non-saturable components, each a function of the unbound OA concentration ([OAu]). The uptake Vmax was identical in C and Z animals, but was increased 2.4-fold in E animals (p < 0.01). The non-saturable uptake rate constant did not differ between groups. Plasma LCFAs averaged 600 microM in C and E and 1,200 microM in Z animals. Total LCFA uptake averaged 1.35, 2.78 and 3.54 pmol/sec/50,000 cells in C, Z, and E animals, respectively. A 2-fold uptake increase in Z animals, in which Vmax was unaltered, entirely reflected the increased plasma LCFA concentration, whereas the 2.6-fold increase in E animals, in which plasma LCFA were not increased, resulted from up-regulation of facilitated transport. Thus, while increased hepatic LCFA uptake contributes to pathogenesis of hepatic steatosis in both obesity and excessive ethanol consumption, the mechanisms differ.

Anisotropic diffusion in layered argillaceous rocks: a case study with Opalinus Clay.

Anisotropic diffusion was studied in Opalinus Clay, a potential host rock for disposal of spent fuel, vitrified high-level waste, and long-lived intermediate-level waste in Switzerland. Diffusion parallel to the bedding was measured using a radial through-diffusion technique and diffusion perpendicular to the bedding bythe classical (planar) through-diffusion technique. The samples used were from Mont Terri (MT) and from Benken (BE). Diffusion of HTO, 36Cl-, and 22Na+ parallel and perpendicular to the bedding was studied under confining pressures of 7 MPa (MT) and 14 MPa (BE). The results indicate that diffusion parallel to the bedding is faster than diffusion perpendicular to the bedding by a factor of 4-6 for the three radionuclides, indicating that the Opalinus Clay is anisotropic. This might be explained by smaller path lengths (tortuosity) for species diffusing parallel to the fabric. The degree of anisotropy is slightly smaller for Opalinus Clay from Mont Terri than from Benken. This is due to the lower overburden pressure in Mont Terri resulting in a lower preferential orientation of the clay platelets.

Lipid metabolism in hepatic steatosis.

Hepatic steatosis is a consequence of both obesity and ethanol use. Nonalcoholic steatosis (NASH) resemble alcoholic steatosis and steatohepatitis. Both exhibit increased hepatocellular triglycerides(TG), reflecting an increase in long chain fatty acids (LCFA). LCFA enter cells by both facilitated transport and passive diffusion. A driving force for both is the plasma unbound LCFA concentration ([LCFAu]). In both obese rodents and obese patients, adipocyte LCFA uptake via both facilitated transport and diffusion is increased. However, the LCFA uptake Vmax in hepatocytes is not increased in obese animals. Nevertheless, total LCFA uptake in obese rodents is increased ~3-fold, reflecting increased plasma LCFA concentrations. With advancing obesity, resistance to the antilipolytic effects of insulin results in increased lipolysis within the omental fat depot, a consequent further rise in portal venous LCFA, and an even greater rise in portal [LCFAu]. This causes a further increase in hepatocellular LCFA uptake, increased intracellular generation of reactive oxygen species (ROS), and transition from simple steatosis to NASH. By contrast, in rodent hepatocytes and in human hepatoma cell lines, ethanol up-regulates the LCFA uptake Vmax. Consequently, although plasma LCFA are unaltered, hepatocellular LCFA uptake in ethanol-fed rats is also increased~3-fold, leading to increased ROS generation and evolution of alcoholic hepatitis. Thus, while increased hepatic LCFA uptake contributes to the pathogenesis of both NASH and alcoholic hepatitis,the underlying mechanisms differ. Recognizing these mechanistic differences is important in developing strategies for both prevention and treatment of these conditions.

White matter hyperintensities are associated with impairment of memory, attention, and global cognitive performance in older stroke patients.

BACKGROUND: The importance of white matter hyperintensities (WMH) for cognitive performance in older stroke patients is largely unknown. We hypothesized that processing speed and executive dysfunction will be associated with frontal WMH whereas impaired memory will be associated with temporal WMH. METHODS: Neuropsychological assessments using the Cambridge Cognitive Examination (CAMCOG) and the Cognitive Drug Research (CDR) were completed for 96 stroke survivors aged older than 75 and 23 age-matched controls. Magnetic resonance imaging whole-brain axial FLAIR images were undertaken to visualize WMH and an automated threshold technique was used to determine their volume. RESULTS: In comparison to controls, the stroke patients had significantly greater volume of WMH in all key areas. Within the stroke group, a consistent pattern of significant association was identified between total and frontal WHM volumes and attention and processing speed tasks (eg, choice reaction time [right: R=0.24 P=0.02; left: R=0.26, P=0.01]), but not with executive function. There were significant associations between memory and temporal WMH volumes (right: R=0.27, P=0.008; left: R=0.20, P=0.047). CONCLUSIONS: In older stroke patients, cognitive processing speed and performance on measures of attention are significantly associated with WMH volume, particularly in the frontal lobe regions, whereas memory impairment is associated with the volume of temporal lobe WMH.

Leptin and insulin modulate nutrient partitioning and weight loss in ob/ob mice through regulation of long-chain fatty acid uptake by adipocytes.

Leptin treatment of ob/ob mice leads to weight loss appreciably greater than that in pair-fed mice. To test whether this "extra" weight loss is mediated by leptin-induced alterations in nutrient partitioning, the effects in ob/ob mice of subcutaneous leptin infusion (500 ng/h for 0.5 vs. normal C57BL/6J controls). Adipocyte mRNA levels for plasma membrane fatty acid binding protein and fatty acid translocase, putative fatty acid transporters that are up-regulated three- to fourfold in adipocytes from ob/ob mice, had also normalized by d 21. The initial changes in V(max) preceded decreases in food intake and body weight by at least 24 h. In pair-fed mice, insulin levels, V(max) and body weight all declined more slowly than in leptin-treated mice, and all remained significantly elevated compared with normal values at d 21. The data suggest that insulin up-regulates and leptin down-regulates adipocyte fatty acid uptake, leading to alterations in fatty acid partitioning that affect adiposity.

Porewater chemistry in compacted re-saturated MX-80 bentonite.

Bentonites of various types are being investigated in many countries as backfill materials in high-level radioactive waste disposal concepts. Being able to understand the chemistry of the porewater in compacted bentonite is very important since it is critical to predicting radionuclide solubilities and to the synthesis of sorption data bases, and hence to repository safety studies. In this paper, porewater compositions in compacted bentonites are calculated, taking into consideration such factors as montmorillonite swelling, semi-permeable membrane effects, very low "free water" volumes, and the highly effective buffering characteristics of the exchangeable cations and the amphoteric edge sites. The former buffer the cation concentrations and the latter fix the pH in the porewater of a re-saturated bentonite. The above considerations are used in conjunction with previously measured physico-chemical characterisation data on MX-80 powder to calculate porewater compositions in compacted bentonites. For the MX-80 material specified, the porewaters calculated for initial dry densities between 1200 and 1600 kg m(-3) had relatively high ionic strengths (I approximately 0.3 M), similar cation concentrations and a pH equal to 8.0. The porewaters changed from being Na(2)SO(4)-rich at 1200 kg m(-3) to a NaCl/Na(2)SO(4) type water at 1600 kg m(-3).

Th uptake on montmorillonite: a powder and polarized extended X-ray absorption fine structure (EXAFS) study.

The uptake process of Th(IV) onto montmorillonite was studied using powder and polarized-EXAFS (P-EXAFS) spectroscopy. Sorption samples were prepared in 0.1 M NaClO(4) solutions either undersaturated (pH 2 and 3, [Th](initial): 2.7x10(-6) to 4x10(-4) M) or supersatured (pH 5, [Th](initial): 4.3x10(-5) to 4x10(-4) M) with respect to amorphous ThO(2). Th loading varied between 1-157 micromol/g at pH 3 and 14-166 micromol/g at pH 5 and equaled 41 micromol/g at pH 2. At pH 5 and high surface loading the EXAFS spectrum resembled that of amorphous Th(OH)(4), suggesting the precipitation of a Th hydrous hydroxide. At low and intermediate surface coverage two O coordination shells at approximately 2.24 and approximately 2.48 A, and one Si shell at 3.81-3.88 A, were systematically observed regardless of pH. The formation of Th nucleation products and Th-Si solution complexes and the sorption of Th on a silica precipitate were excluded from the EXAFS spectra analysis and solution chemistry. In these conditions, Th was shown to bond the montmorillonite surface by sharing double corners with Si tetrahedra. This structural interpretation is consistent with surface coverage calculations which showed that the edge sites were saturated in the two highest concentrated samples (34 and 157 micromol/g) at pH 3.