Renal artery aneurysm endovascular repair.

A 68-year-old woman with a left renal artery aneurysm underwent successful endovascular repair with the use of a commercial type self-expanding stent-graft. Complete aneurysm exclusion was achieved after stent-graft expansion. A side branch vessel was occluded after stent-placement, resulting in a small upper lobe renal perfusion defect. There were no other complications. The aneurysm remained excluded and its greatest diameter has been reduced from 2.6 cm to 1.95 cm, 10 months after treatment. Renal function remained normal.     

Effects of tumor necrosis factor alpha on parathyroid hormone-induced increases in osteoblastic cell cyclic AMP

Summary Tumor necrosis factor α (10⁻¹⁰–10⁻⁸M) had no effects on cyclic AMP production by the osteoblastic osteosarcomal cells, Saos-2 and G292, or normal rat calvarial cells. The cytokine did, however, inhibit the parathyroid hormone (PTH)-induced effect on cyclic AMP in the Saos-2 and normal rat osteoblastic cells. This inhibitory effect did not occur on prostaglandin E₂-induced cyclic AMP increases in the osteoblastic cells. Interleukin-1 (10 U/ml −100 U/ml) did not produce any effect on basal levels or PTH-induced cyclic AMP increases in these cells.     

α<Subscript>2β</Subscript> adrenoreceptor 301–303 deletion polymorphism in polycystic ovary syndrome

α_2β adrenoreceptor 301–303 deletion polymorphism does not influence basal metabolic rate, insulin resistance or weight gain in Greek women with polycystic ovary syndrome.     

Primate motor cortex and free arm movements to visual targets in three-dimensional space. II. Coding of the direction of movement by a neuronal population

We describe a code by which a population of motor cortical neurons could determine uniquely the direction of reaching movements in three-dimensional space. The population consisted of 475 directionally tuned cells whose functional properties are described in the preceding paper (Schwartz et al., 1988). Each cell discharged at the highest rate with movements in its "preferred direction" and at progressively lower rates with movements in directions away from the preferred one. The neuronal population code assumes that for a particular movement direction each cell makes a vectorial contribution ("votes") with direction in the cell's preferred direction and magnitude proportional to the change in the cell's discharge rate associated with the particular direction of movement. The vector sum of these contributions is the outcome of the population code (the "neuronal population vector") and points in the direction of movement in space well before the movement begins.     

Tolerance in TCR/Cognate Antigen Double-Transgenic Mice Mediated by Incomplete Thymic Deletion and Peripheral Receptor Downregulation

Influenza nucleoprotein (NP)-specific T-cell receptor transgenic mice (F5) were crossed with transgenic mice expressing the cognate antigenic protein under the control of the H- 2K^b promoter. Double-transgenic mice show negative selection of thymocytes at the CD4⁺8⁺TCR¹⁰ to CD4⁺8⁺TCR^hi transition stage. A few CD8 T cells, however, escape clonal deletion, and in the peripheral lymphoid organs of these mice, they exhibit low levels of the transgenic receptor and upregulated levels of the CD44 memory marker. Such cells do not proliferate upon exposure to antigen stimulation in vivo or ex vivo, however, they can develop low but detectable levels of antigen-specific cytotoxic function after stimulation in vitro in the presence of IL-2.     

Genetic association between the phospholipase A2 gene and unipolar affective disorder: a multicentre case-control study

The co-segregation in one pedigree of bipolar affective disorder with Darier's disease whose gene is on chromosome 12q23-q24.1, and findings from linkage and association studies with the neighbouring gene of phospholipase A2 (PLA2) indicate that PLA2 may be considered as a candidate gene for affective disorders. All relevant genetic association studies, however, were conducted on bipolar patients. In the present study, the possible association between the PLA2 gene and unipolar affective disorder was examined on 321 unipolar patients and 604 controls (all personally interviewed), recruited from six countries (Belgium, Bulgaria, Croatia, Germany, Greece, and Italy) participating in the European Collaborative Project on Affective Disorders. After controlling for population group and gender, one of the eight alleles of the investigated marker (allele 7) was found to be more frequent among unipolar patients with more than three major depressive episodes than among controls (P<0.01); genotypic association was also observed, under the dominant model of genetic transmission (P<0.02). In addition, presence of allele 7 was correlated with a higher frequency of depressive episodes (P<0.02). These findings suggest that structural variations at the PLA2 gene or the chromosomal region around it may confer susceptibility for unipolar affective disorder.     

A reinvestigation of the cross-reactivity between Klebsiella and HLA-B27 in the aetiology of ankylosing spondylitis.

The existence of cross-reactivity between Klebsiella antigens and cells from donors who are HLA-B27 positive and exhibit ankylosing spondylitis (AS) has been reinvestigated. Cells and antisera from different laboratories have been tested together using simultaneously microcytoxicity, chromium release and enzyme linked immunosorbent assays (ELISA). No reproducible interaction has been found. Mitogenic stimulation did not induce cross-reactivity and 'transformation' of B27+AS- cells by Klebsiella culture supernatants failed. Two transformed cell lines from B27+ AS+ donors exhibited specific cross reaction with two anti-Klebsiella antisera but only by chromium release. Immunoprecipitation with these cells and antisera showed the absence of any AS+ -specific antigen. It is concluded that the involvement of Klebsiella in ankylosing spondylitis through simple immunological cross-reactivity or through interaction with HLA-B27 is unlikely.     

Motor cortical activity in a memorized delay task

Summary Two rhesus monkeys were trained to move a handle on a two-dimensional (2D) working surface in directions specified by a light at the plane. They first captured with the handle a light on the center of the plane and then moved the handle in the direction indicated by a peripheral light (cue signal). The signal to move (go signal) was given by turning off the center light. The following tasks were used: (a) In the non-delay task the peripheral light was turned on at the same time as the center light went off. (b) In the memorized delay task the peripheral light stayed on for 300 ms and the center light was turned off 450–750 ms later. Finally, (c) in the non-memorized delay task the peripheral light stayed on continuously whereas the center light went off 750–1050 ms after the peripheral light came on. Recordings in the arm area of the motor cortex (N= 171 cells) showed changes in single cell activity in all tasks. In both delay tasks, the neuronal population vector calculated every 20 ms after the onset of the peripheral light pointed in the direction of the upcoming movement, which was instructed by the cue light. Moreover, the strength of the population signal showed an initial peak shortly after the cue onset in both the memorized and non-memorized delay tasks but it maintained a higher level during the memorized delay period, as compared to the non-memorized task. These results indicate that the motor cortex is involved in encoding and holding in memory directional information concerning a visually cued arm movement and that these processes can be visualized using neuronal population vector analysis.     

Cro mutants of phage 434.

Phage 434 cro⁴³⁴ mutants have been isolated and characterized as plaque formers on groN bacteria, which block wild-type 434 and λ development at the level of action of the N gene product (Georgopoulos, 1971). Like the corresponding λ cro^λ mutants, they map within the immunity region and to the right of the cI gene, they overproduce the exonuclease gene product, they are unable to propagate on wild-type bacteria (especially at 42°), and in mixed infections they suppress the growth of heteroimmune but not homoimmune cro⁺ phage.