Age‐related changes in brain energetics and phospholipid metabolism

Evidence suggests that mitochondria undergo functional and morphological changes with age. This study aimed to investigate the relationship of brain energy metabolism to healthy aging by assessing tissue specific differences in metabolites observable by phosphorus (³¹P) MRS. ³¹P MRSI at 4 Tesla (T) was performed on 34 volunteers, aged 21–84, screened to exclude serious medical and psychiatric diagnoses. Linear mixed effects models were used to analyze the effects of age on phosphorus metabolite concentrations, intracellular magnesium and pH estimates in brain tissue. A significant age associated decrease in brain pH (?0.53% per decade), increase in PCr (1.1% per decade) and decrease in PME (1.7% per decade) were found in total tissue, with PCr effects localized to the gray matter. An increase in beta NTP as a function of age (1% per decade) approached significance (p = 0.052). There were no effects demonstrated with increasing age for intracellular magnesium, PDE or inorganic phosphate. This study reports the effects of healthy aging on brain chemistry in the gray matter versus white matter using ³¹P MRS measures of high energy phosphates, pH and membrane metabolism. Increased PCr, increased beta NTP (reflecting ATP) and reduced pH may reflect altered energy production with healthy aging. Unlike some previous studies of aging and brain chemistry, this study examined healthy, non‐demented and psychiatrically stable older adults and specifically analyzed gray‐white matter differences in brain metabolism. Copyright © 2009 John Wiley & Sons, Ltd.     

Kidney involvement and renal manifestations in non-Hodgkin's lymphoma and lymphocytic leukemia: a retrospective study in 700 patients

Renal involvement as part of systemic lymphoma (LY) is quite frequent, however, primary extranodal renal non-Hodgkin's lymphoma (NHL) is extremely rare, and only about 65 cases have been reported in the world literature. In a retrospective study of renal manifestations in 700 patients with documented LY and chronic lymphocytic leukemia (CLL) seen at our hospital during 1986-95, 83 patients had signs of acute renal failure. Only five of these had proven renal infiltration, but none of them satisfied the criteria for primary renal LY. Glomerulonephritis (GN) has also rarely been reported in association with LY and CLL, and only 37 glomerular lesions in NHL and 42 in CLL have been documented, respectively. GN may precede, coexist, or follow the diagnosis of LY by several years. Of the 42 cases of CLL reported worldwide, 36 had nephrotic syndrome. Renal failure was seen in about one third. The most common glomerular lesion reported is membranoproliferative GN, followed by membranous GN. In our study, we found only five biopsy-proven cases with GN amongst the 700 patients seen. In this report we also briefly describe some rare interesting associated renal syndromes in CLL and NHL.     

Reactive oxygen and nitrogen intermediates in the relationship between mammalian hosts and microbial pathogens

This review summarizes recent evidence from knock-out mice on the role of reactive oxygen intermediates and reactive nitrogen intermediates (RNI) in mammalian immunity. Reflections on redundancy in immunity help explain an apparent paradox: the phagocyte oxidase and inducible nitric oxide synthase are each nonredundant, and yet also mutually redundant, in host defense. In combination, the contribution of these two enzymes appears to be greater than previously appreciated. The remainder of this review focuses on a relatively new field, the basis of microbial resistance to RNI. Experimental tuberculosis provides an important example of an extended, dynamic balance between host and pathogen in which RNI play a major role. In diseases such as tuberculosis, a molecular understanding of host-pathogen interactions requires characterization of the defenses used by microbes against RNI, analogous to our understanding of defenses against reactive oxygen intermediates. Genetic and biochemical approaches have identified candidates for RNI-resistance genes in Mycobacterium tuberculosis and other pathogens.     

Additive value of low-dose dobutamine to technetium-99m sestamibi-gated single-photon emission computed tomography for prediction of wall motion improvement in patients undergoing coronary artery bypass graft

BACKGROUND: The two most useful methods for myocardial viability assessment are perfusion imaging and dobutamine echocardiography. HYPOTHESIS: The present study investigated the additive value of a new method, dobutamine technetium 99m (99mTc)-sestamibi-gated single-photon emission computed tomography (SPECT), which combines these two modalities, to the prediction of wall motion improvement after revascularization. METHODS: Fifty-five consecutive patients with ischemic cardiomyopathy, who were referred for viability evaluation, underwent resting and dobutamine (dose, 5-10 microkg/kg/min) gated SPECT with 99mTc-sestamibi. Of these patients, 36 underwent coronary artery bypass graft (CABG) within 1 month of the study and 32 had repeat resting gated SPECT within 1 year. Global and regional wall motion, wall thickness, and perfusion were simultaneously analyzed at rest and after dobutamine using the 20-segment model; the sestamibi uptake and wall motion response to dobutamine of each segment were rated quantitatively. Based on these findings, the segments were categorized as normal, viable, or nonviable. The predictive values for wall motion improvement were assessed by perfusion, using cutoffs of 50 and 60% of sestamibi uptake, and thereafter by the addition of dobutamine response in the segments that were rated nonviable. RESULTS: Of the 1,080 myocardial segments studied, 906 (84%) had abnormal wall motion and were analyzed for viability. Concordance between perfusion and wall motion response to dobutamine was 60% with the 50% cutoff of sestamibi uptake, and increased to 65% with the 60% sestamibi cutoff (p < 0.04). The respective predictive values of wall motion improvement using the 50 and 60% cutoff points were as follows: sensitivity 93 and 70%, respectively, (p < 0.01); specificity 59 and 86% (p < 0.001), respectively; accuracy 77% for both. The addition of the wall motion response to dobutamine to the assessment of the nonviable segments by perfusion (60% cutoff) increased the sensitivity from 70 to 85% (p = 0.001) and the negative predictive value from 70 to 81% (p = 0.009); the positive predictive value remained high (86 vs. 82%). No additive value of wall motion response to dobutamine was demonstrated for nonviable segments by perfusion with a 50% cutoff. CONCLUSION: Dobutamine sestamibi-gated SPECT is a feasible method for the analysis of myocardial perfusion, function, and contractile reserve of individual myocardial segments in patients with ischemic cardiomyopathy. Viability assessment based on a threshold of 60% uptake of sestamibi, with the addition of the wall motion response to dobutamine in the nonviable segments, seems to yield better predictive values for wall motion improvement after CABG.     

Internal jugular venous thrombosis after in vitro fertilization

Internal jugular vein thrombosis is an uncommon entity with high morbidity and an increased risk of mortality. Spontaneous clotting of the internal jugular vein without any known risk factors is virtually unheard of, and intravenous drug use is the most common cause for thrombosis. Assisted reproductive techniques alone or in conjunction with ovarian hyperstimulation syndrome seem to predispose patients for thrombosis of the internal jugular vein. We present the case of a patient who, after in vitro fertilization, developed ovarian hyperstimulation syndrome and clotted the internal jugular vein. In the setting of the Emergency Department, the norm should be to "rule out internal jugular venous thrombosis" in pregnant patients who have undergone in vitro fertilization and present with neck pain, with or without swelling or distended collaterals.     

Differential attraction of Aedes albopictus in the field to flowers, fruits and honeydew

Sugar is the main source of energy for the activities of mosquitoes; however, information on the vital sugar feeding of Aedes albopictus in the field is scanty and often anecdotal. Using glue traps and baits, we evaluated the attraction of Ae. albopictus to 28 different, potential sugar sources. Control traps were baited with either sugar–water solution or water alone, and since there was no significant difference between these controls, the water control was used as the standard for comparison. The total catch amounted to 1347 females and 1127 males. An attraction index (mean number of mosquitoes attracted to the baits/mean number of mosquitoes attracted to the control) was used to compare the relative attraction of the baits. The attraction index of significantly attractive baits ranged from 2.5 to 50.0 and the index of others ranged from 0.50 to 2.75. None of the baits were repellent. Significantly high attraction was observed for four of six ornamental flowers (Tamarix chinensis, Vitex agnus-castus, Polygonum baldchuanicum, Buddleja davidii), four of eleven wild flowers (Prosopis farcta, Ziziphus spina-christi, Polygonum equisetiforme, Ceratonia siliqua), the only tested seed pod when damaged and fermenting (C. siliqua), and all five of the tested fruits: Opuntia ficus indica (sabra), Ficus carica (fig), Punica granatum (pomegranate, damaged), Eriobotyra japonica (loquat), and Rubus sanctus (raspberry). Unlike damaged, fermenting carob seed pods and pomegranates, the fresh fruits were not attractive. Attraction to foliage soiled with honeydew excretion of three different aphid species was also not significant. The potential to use attractive sugar sources for mosquito control is discussed.     

Patches of synchronized activity in the cerebellar cortex evoked by mossy-fiber stimulation: Questioning the role of parallel fibers

The discrepancy between the structural longitudinal organization of the parallel-fiber system in the cerebellar cortex and the functional mosaic-like organization of the cortex has provoked controversial theories about the flow of information in the cerebellum. We address this issue by characterizing the spatiotemporal organization of neuronal activity in the cerebellar cortex by using optical imaging of voltage-sensitive dyes in isolated guinea-pig cerebellum. Parallel-fiber stimulation evoked a narrow beam of activity, which propagated along the parallel fibers. Stimulation of the mossy fibers elicited a circular, nonpropagating patch of synchronized activity. These results strongly support the hypothesis that a beam of parallel fibers, activated by a focal group of granule cells, fails to activate the Purkinje cells along most of its length. It is thus the ascending axon of the granule cell, and not its parallel branches, that activates and defines the basic functional modules of the cerebellar cortex.     

Lymphoma with multi gene rearrangement on the level of immunoglobulin heavy chain,light chains,and T-cell receptor β chain

A unique case with diffuse mixed malignant lymphoma was investigated for gene rearrangement on the level of T-cell receptor (TCR), heavy chain immunoglobulin (Ig), and both light chains. Cell phenotype was examined with immunofluorescence techniques using antibodies against surface immunoglobulins (Slg) and the kappa and lambda light chains. Monoclonal antibodies were used against CD3, CD4, CD5, CD8, CD10, CD19, CD22, HLA-DR, and TdT. Gene rearrangement analysis for monoclonality determination was carried out with restricted DNA (EcoR I and Hind III) hybridized with one of the following ³²P-labelled probes: T-cell receptor (TCR |gb), immunoglobulin heavy chain (JH), k light chain, and |gl light chain. Phenotyping of the cell population from the excised lymph node (LN) revealed the presence of 66% B-cells and 35% T-cells. Most of the B cells (94%) expressed μ heavy chain only. Expression of both light chains was negligible (k = 7% and λ = 2%). Gene rearrangement, which indicates monoclonality, was positive on the level of TCR, Ig heavy chain, and both light chains. The data obtained suggests a neoplastic transforming event in lymphoid stem cells, which preceded the subsequent differentiation process into either B or T lymphoma. Am. J. Hematol. 56:219–223, 1997. © 1997 Wiley-Liss, Inc.