Choriocarcinoma metastatic to the lung. A cytologic study with identification of human choriogonadotropin with an immunoperoxidase technique

A case of choriocarcinoma metastatic to the lung following a previous hydatidiform mole is presented. It was possible to make definitive identification of trophoblastic elements on a needle aspiration biopsy using an immunoperoxidase staining technique, thus avoiding diagnostic thoracotomy prior to therapeutic intervention. A method of immunoperoxidase staining of previously fixed and Papanicolaou-stained needle aspiration biopsy specimens is also described, and other uses of the immunoperoxidase technique on needle biopsy specimens are discussed.     

Increased anxiety-like behavior and enhanced synaptic efficacy in the amygdala of GluR5 knockout mice

GABAergic transmission in the amygdala modulates the expression of anxiety. Understanding the interplay between GABAergic transmission and excitatory circuits in the amygdala is, therefore, critical for understanding the neurobiological basis of anxiety. Here, we used a multi-disciplinary approach to demonstrate that GluR5-containing kainate receptors regulate local inhibitory circuits, modulate the excitatory transmission from the basolateral amygdala to the central amygdala, and control behavioral anxiety. Genetic deletion of GluR5 or local injection of a GluR5 antagonist into the basolateral amygdala increases anxiety-like behavior. Activation of GluR5 selectively depolarized inhibitory neurons, thereby increasing GABA release and contributing to tonic GABA current in the basolateral amygdala. The enhanced GABAergic transmission leads to reduced excitatory inputs in the central amygdala. Our results suggest that GluR5 is a key regulator of inhibitory circuits in the amygdala and highlight the potential use of GluR5-specific drugs in the treatment of pathological anxiety.     

Residue 3 of β2-microglobulin affects binding of class I MHC molecules by the W6/32 antibody

 Previous studies of class I MHC molecules have shown that the owl monkey (Aotus) possesses at least two variants of the β₂-microglobulin (β₂m) protein. These two variants have different isoelectric points, and exhibit differential reactivity with the monoclonal antibody W6/32. We report cDNA sequences of the B2m gene, from W6/32-positive and W6/32-negative Aotus cell lines. The two β₂m variants we identified exhibit a single amino acid difference at position three. An arginine residue at position 3 was correlated with W6/32 reactivity, whereas histidine was associated with non-reactivity. W6/32 reactivity was conferred to a W6/32-negative Aotus cell line when it was transfected with the B2m from the W6/32-positive cell line. Residue 3 of β₂m is located at the surface of the class I molecule. It is also close to position 121 of the MHC class I heavy chain, which has previously been shown to influence W6/32 antibody binding. We conclude that W6/32 binds a compact epitope on the class I molecule that includes both residue 3 of β₂m and residue 121 of the heavy chain. We examined the distribution of the two β₂m motifs in a sample Aotus population using an allele-specific polymerase chain reaction assay. The pattern of β₂m segregation we observed matches that which was defined previously by serology. Additionally, we identified laboratory-born hybrid animals who possess both variants of β₂m. Received: 1 April 1998 / Received: 3 July 1998     

The design and synthesis of purine inhibitors of CDK2. III

Cyclin-dependent kinases (CDKs) belong to a class of enzymes that control the ability of a cell to enter into and proceed through the cell division cycle. Using purine as a scaffold, we have synthesized a number of nanomolar inhibitors of CDK-2/cyclin E. In this report, the synthesis of a series of piperidine-substituted purine analogs will be presented, as well as some of their in vitro and in vivo biological effects.     

SM22beta encodes a lineage-restricted cytoskeletal protein with a unique developmentally regulated pattern of expression

Cytoskeletal proteins play important roles in regulating cellular morphology, cytokinesis and intracellular signaling. In this report, we describe a developmentally regulated gene encoding a novel cell lineage-restricted cytoskeletal protein, designated SM22beta. SM22beta shares high-grade sequence identity with the smooth muscle cell (SMC)-specific protein, SM22alpha, the neuron-specific protein, NP25, and the Drosophila melanogaster flight muscle-specific protein, mp20. The mouse SM22beta cDNA encodes a 199-amino acid polypeptide that contains a single conserved calponin-like repeat domain. During mouse embryonic development, the SM22beta gene is expressed in a temporally and spatially regulated pattern in the tunica media of arteries and veins, endocardium and compact layer of the myocardium, bronchial epithelium and mesenchyme of the lung, gastrointestinal epithelium and cartilaginous primordia. During postnatal development, SM22beta is co-expressed with SM22alpha in arterial and venous SMCs. In addition, SM22beta is expressed at high levels in the bronchial epithelium and lung mesenchyme, gastrointestinal epithelial cells and in the cartilagenous and periosteal layer of bones. Three-dimensional deconvolution microscopic analyses of A7r5 SMCs revealed that SM22beta co-localizes with SM22alpha to cytoskeletal actin filaments. Taken together, these data demonstrate that SM22beta is a novel actin-associated protein with a unique cell lineage-restricted pattern of expression.     

Utility of poly(ethylene glycol) conjugation to create prodrugs of amphotericin B

This paper reports on the synthesis, safety, and efficacy of a series of water-soluble derivatives of poly(ethylene glycol) (PEG)-conjugated amphotericin B (AmB). PEG 40 000 attached to the sugar amino group of AmB via labile carbamate and carbonate linkages was examined. The synthetic program conducted for this investigation provided a series of disubstituted PEG-AmB derivatives which had in vitro PEG half-life of hydrolyses rates in rat plasma varying between 1 and 3 h. Importantly, all conjugates demonstrated less than 6% hydrolysis following 24 h incubation in pH 7.4 phosphate buffer at 25 degrees C and showed solubilities greater than 46 mg/mL in aqueous solutions. The solubility of AmB in the conjugates increased up to approximately 200 times compared to unmodified AmB in saline. As a major finding, this investigation demonstrated that conjugation of PEG to AmB could produce conjugates that were significantly (6x) less toxic than AmB-deoxycholate and maintained, or even had enhanced, in vivo antifungal activity.     

Occupational magnetic field exposures of garment workers: results of personal and survey measurements

To explore the feasibility of performing an epidemiologic study of female breast cancer and magnetic field (MF) exposures, we chose to study garment workers, who reportedly have some of the highest MF exposures. We collected personal exposure (PE, n = 48) and survey measurements (n = 77) near commercial sewing machines at three garment facilities and conducted a pilot interview among 25 garment workers asking about exposure duration, activities, and machine characteristics. MF levels were higher for older machines with alternating current (AC) than newer machines with direct current (DC) motors. MF levels were comparable for both idling and sewing activities. Most interviewed workers could describe duration of exposure and machine type (automatic/manual), but not other machine characteristics. Measurements were lower than previously reported for garment workers but were higher than exposures to most women. A historical exposure assessment can be conducted by linking duration of exposure with reconstructed exposure measurements but may be limited by the accuracy of work history data.     

The tetraspanin CD9 associates with transmembrane TGF-alpha and regulates TGF-alpha-induced EGF receptor activation and cell proliferation

Transforming growth factor-alpha (TGF-alpha) is a member of the EGF growth factor family. Both transmembrane TGF-alpha and the proteolytically released soluble TGF-alpha can bind to the EGF/TGF-alpha tyrosine kinase receptor (EGFR) and activate the EGFR-induced signaling pathways. We now demonstrate that transmembrane TGF-alpha physically interacts with CD9, a protein with four membrane spanning domains that is frequently coexpressed with TGF-alpha in carcinomas. This interaction was mediated through the extracellular domain of transmembrane TGF-alpha. CD9 expression strongly decreased the growth factor- and PMA- induced proteolytic conversions of transmembrane to soluble TGF-alpha and strongly enhanced the TGF- alpha-induced EGFR activation, presumably in conjunction with increased expression of transmembrane TGF-alpha. In juxtacrine assays, the CD9-induced EGFR hyperactivation by transmembrane TGF-alpha resulted in increased proliferation. In contrast, CD9 coexpression with transmembrane TGF-alpha decreased the autocrine growth stimulatory effect of TGF-alpha in epithelial cells. This decrease was associated with increased expression of the cdk inhibitor, p21(CIP1). These data reveal that the association of CD9 with transmembrane TGF-alpha regulates ligand-induced activation of the EGFR, and results in altered cell proliferation.