A new class of phytoalexins from grapevines

Summary Novel phytoalexins which have been isolated from grapevine leaves are oligomeric forms of the trihydroxy stilbene resveratrol, which co-occurs with these compounds. The characterization of one of these phytoalexins as a resveratrol dimer, designated -viniferin, is described as well as a model for its biosynthesis from resveratrol.     

Arylpyridyl-thiosemicarbazones: A new class of anti-juvenile hormones active against Lepidoptera

Summary A new class of anti-juvenile hormone agents is described. Active anti-juvenile hormone compounds were either diazine thiosemicarbazones or aryl substituted pyridyl thiosemicarbazones, synthesized from substituted benzaldehydes. While many analogs in these classes showed feeding and growth inhibition in a variety of insects, a select group caused formation of precocious pupal characteristics inAgrotis ipsilon (black cutworm) andHeliothis virescens (tobacco budworm) and black cuticle and precocious pupae inManduca sexta (tobacco hornworm). They were active only by diet incorporation. The symptoms of precocious development could be reversed by co-administration of a juvenoid. One of the active compounds was shown to inhibit juvenile hormone biosynthesis in vitro by corpora allata of the cockroachDiploptera punctata. However, none of the compounds were active inhibitors of purified chicken liver prenyl transferase.     

Velocity sedimentation of tumor cells: A comparison of methods

Summary Tumor cells isolated from a murine fibrosarcoma were grown in primary culture for two days and then separated on a basis of size by velocity sedimentation. Centrifugal elutriation and STAPUT methods were compared for their ability to isolate biophysically unique tumor subpopulations. The isolated cell fractions were assayed for cell number, incorporation of triatiated thymidine and Coulter volume. Both methods were comparable with regard to ability to separate tumor cells on a basis of size. Elutriation had the advantage of speed but required sophisticated equipment. The STAPUT method was less expensive but required somewhat longer times for separation.Supported in part by NIH-NCI grants No. CA-06294 and CA-18628.     

Cephalothin-treated normal red cells: A new type of PNH-like cells

Riassunto Emazie umane normali trattate con cefalotina, in opportune condizioni sperimentali, si comportano in alcuni test di emolisi in vitro (test di emolisi acida, test di sensibilità agli isoanticorpi freddi) in modo simile alle emazie della emoglobinuria parossistica notturna (EPN) (emazie simil-EPN). A differenza di altri tipi di emazie simil-EPN, queste emazie danno anche un test di Coombs diretto positivo, di tipo non. Viene avanzata l'ipotesi che la lesione responsabile del comportamento simil-EPN di queste emazie sia da ricercare in una alterazione delle proteine stromali.     

A gelatin sponge model for studying tumor growth: quantitation of tumor cells and leukocytes in the CHO tumor

A gelatin sponge model system for tumor cell inoculation and retrieval of tumor-associated leukocytes is described. Gelatin sponges pre-implanted in nude mice harboring tumorigenic Chinese hamster ovary cells (line CHO) were examined at 2 and 11 days after injection of tumor cells for tumor cell content and leukocyte accumulation after digesting the sponge matrix in collagenase solution. The data indicate a progressive influx of host cells consisting primarily of macrophages, neutrophils and lymphocytes. The total number of viable tumor cells as well as the fraction of surviving tumor cells with clonogenic potential also increased with tumor age. Blank sponges not harboring tumor cells elicited an inflammatory response in the animals which did not change appreciably with length of sponge residence. However, when the sponges were harboring tumor cells, the accumulation of host leukocytes far exceeded that which occurred in blank sponges. This observation suggests a host response directed toward the tumor which is absent in animals bearing blank sponges. Apart from providing anchorage for injected cells, the gelatin sponge, by virtue of its digestibility in collagenase, makes possible the easy retrieval and precise quantitation of tumor-associated host cells.     

A method for injection and transplantation of nuclei and cells inDrosophila eggs

Summary Microinjection ofDrosophila eggs using the principle of thermal expansion is described. The eggs, mounted on cover slips with adhesive, are slightly dried to avoid the formation of exudate and then covered with fluorocarbon oil. Injections are made with a specially designed electrically controlled micropipette.     

A gelatin sponge model for studying tumor growth: quantitation of tumor cells and leukocytes in the CHO tumor

Summary A gelatin sponge model system for tumor cell inoculation and retrieval of tumor-associated leukocytes is described. Gelatin sponges pre-implanted in nude mice harboring tumorigenic Chinese hamster ovary cells (line CHO) were examined at 2 and 11 days after injection of tumor cells for tumor cell content and leukocyte accumulation after digesting the sponge matrix in collagenase solution.The data indicate a progressive influx of host cells consisting primarily of macrophages, neutrophils and lymphocytes. The total number of viable tumor cells as well as the fraction of surviving tumor cells with clonogenic potential also increased with tumor age. Blank sponges not harboring tumor cells elicited an inflammatory response in the animals which did not change appreciably with length of sponge residence. However, when the sponges were harboring tumor cells, the accumulation of host leukocytes far exceeded that which occurred in blank sponges. This observation suggests a host response directed toward the tumor which is absent in animals bearing blank sponges. Apart from providing anchorage for injected cells, the gelatin sponge, by virtue of its digestibility in collagenase, makes possible the easy retrieval and precise quantitation of tumor-associated host cells.Supported by the United States Department of Energy and National Institutes of Health Grant P41-RR01315.     

Rosette formation of tumor cells with concanavalin A treated erythrocytes

Summary Trypsinized human erythrocytes were incubated with concanavalin A at 4°C. After removal of free concanavalin A, the erythrocytes were incubated with Ehrlich ascites tumor cells at 37°C. The erythrocytes formed rosettes with the tumor cells.     

A one-drop cryoscope: The tonicity of frog and goldfish sera

Zusammenfassung Es wird eine einfache Modifikation eines Kryoskopes zur objektiven Messung von Gefrierpunktserniedrigungen im Bereiche von 20 µl beschrieben. Das Instrument eignet sich u.a. zur Bestimmung der Gefrierpunktserniedrigungen des Wirbeltierblutes.

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This work was supported by Grant 619A from the Damon Runyon Memorial Fund for Cancer Research, Publication No. 109 of the Department of Biology, Wayne State University.     

The polycystins: a novel class of membrane-associated proteins involved in renal cystic disease

Polycystin-1, polycystin-2 and polycystin-L are the predicted protein products of the PKD1, PKD2 and PKDL genes, respectively. Mutations in PKD1 and PKD2 are responsible for almost all cases of autosomal dominant polycystic kidney disease (ADPKD). This condition is one of the commonest mendelian disorders of man with a prevalence of 1:800 and is responsible for nearly 10% of cases of end-stage renal failure in adults. The cloning of PKD1 and PKD2 in recent years has provided the initial steps in defining the mechanisms underlying renal cyst formation in this condition, with the aim of defining pharmacological and genetic interventions that may ameliorate the diverse and often serious clinical manifestations of this disease. The PKD genes share regions of sequence similarity, and all predict integral membrane proteins. Whilst the predicted protein domain structure of polycystin-1 suggests it is involved in cell-cell or cell-matrix interactions, the similarity of polycystin-2 and polycystin-L to the pore-forming domains of some cation channels suggests that they all form subunits of a large plasma membrane ion channel. In the few years since the cloning of the PKD genes, a consensus that defines the range of mutations, expression pattern, interactions and functional domains of these genes and their protein products is emerging. This review will therefore attempt to summarise these data and provide an insight in to the key areas in which polycystin research is unravelling the mechanisms involved in renal cyst formation. Received 22 February 1999; received after revision 5 July 1999; accepted 6 July 1999     

Cytological investigations with a new class of cytotoxic agents: Methylhydrazine derivatives

Zusammenfassung Mittels cytologischer Untersuchungen wurde versucht, einen Einblick in den Wirkungsmechanismus der tumorhemmenden Methylhydrazinverbindungen zu gewinnen. 1-Methyl-2-benzyl-hydrazinphosphat bewirkt beim Ehrlich-Ascites-Carcinom der Maus einen Abfall des Mitoseindexes, eine Verschiebung des Mitosephasenindexes zugunsten der Metaphase sowie das Auftreten von Chromatidbrüchen. Diese Befunde werden diskutiert.     

Tumour inhibitory effects of a new class of cytotoxic agents: Methylhydrazine derivatives

Zusammenfassung Die tumorhemmende Wirkung einer neuen Klasse von Cytostatica (Methylhydrazinderivate) wird beschrieben. Das Wachstum des Ehrlich-Carcinoms in solider und ascitischer Form, des Crocker Sarkoms S 180, des Walker-Carcinosarkoms 256 und des Uterus-Epithelioms T 8 wird deutlich gehemmt. 1-Methyl-2-p-(isopropylcarbamoyl)benzyl-hydrazin-hydrochlorid (I) und 1-Methyl-2-p-allophanoylbenzyl-hydrazin-hydrobromid (II) zeichnen sich durch besonders starke cytostatische Aktivität aus.