Human platelets exert cytotoxic effects on tumor cells

Monocytes are thought to play a role in host resistance to tumor cell growth in animals and humans. In addition, platelets are known to be involved in tumor metastases. To investigate the interaction of these two cell types and their effect on tumor cells, human monocytes and platelets were examined using an in vitro monocyte-tumor cell cytotoxicity assay. Monocytes alone resulted in 32% +/- 1.5 (mean +/- SEM) tumor cell kill. When platelets were added to monocytes in a 1:1 ratio, an increase in cytotoxicity to 61% +/- 3.2 was observed. The cytotoxicity noted when platelets were added to a fixed number of monocytes and tumor cells was dependent on the number of platelets added. A decrease in cytotoxicity from 32% +/- 1.5 to 12% +/- 2.3 was observed when contaminating platelets were removed from monocyte preparations. Platelets added to tumor cells in the absence of any monocytes were also toxic, resulting in a maximum kill of 95% at a 4:1 platelet/tumor cell ratio. Secreted products of freshly isolated platelets may be responsible for much of the observed cytotoxicity, since supernatants from the platelets were toxic for tumor cells. Platelets pretreated with a cyclooxygenase inhibitor (ASA) or a lipoxygenase inhibitor had decreased cytotoxicity compared with untreated platelets. Our results indicate that products of platelet arachidonate metabolism are toxic for tumor cell lines. They also suggest that the role of the platelet must be considered when studying monocyte-tumor cell cytotoxicity.     

Hairy cell leukemia and myelomatosis: chance association or clinical manifestations of the same B-cell disease spectrum

We describe three patients who had typical features of hairy cell leukemia (HCL) and multiple myeloma (MM) at the same time. In two, both diagnoses were made within a short period of time, and in the third, HCL had been present for 2 yr before the appearance of a paraprotein, bone lesions, and plasma-cell infiltrates established the diagnosis of MM. Although this association has not been previously reported, cases of HCL with osteolytic lesions or a paraprotein band have been described. The cases described may represent clinical manifestations of closely related disorders arising from divergent differentiation from a common B-cell precursor rather than a chance association.     

Salt-dependent conformational diversity of alternating poly (Glu-Leu)

Alternating poly(Glu-Leu) was synthesized by the condensation of the corresponding dipeptide p-nitrophenyl ester at high concentration. It exhibits a random coil structure in pure water at neutral pH. Addition of monovalent cations, such as NH⁺₄ to a final 0.1 M solution, induces a transition to a water soluble β-structure. The salt effect is quite selective since no transition was observed with Li⁺, Na⁺ or Cs⁺ ions. Addition of 0.5 equiv. of calcium, cobalt or manganese chlorides per glutamyl residue induces similar coil to β-sheet transitions. No polymer precipitation was observed at these very low salt concentrations. Addition of 0.5 equiv. of Cu²⁺ or 0.15 equiv. of Fe³⁺ induces a coil to α-helix transition. Molecular modeling has been used to understand tentatively the main factors controlling the different conformations observed with the various metal ions. © Munksgaard 1997.     

Treatment of vaginal agenesis with modified Abbé-Mclndoe technique

In a patient with vaginal agenesis reconstruction of the neovagina is very important both functionally and psychologically. The absent vagina can be constructed either by surgery or by an intermittent pressure technique defined by Frank. In this paper simple modification is presented which has good anatomical and functional results. For a young woman without a vagina the ideal operation should create a vagina in one stage and at the same time produce a cosmetically attractive scar. This goal can be achieved by the Abbé-McIndoe technique. A modification using a meshed split thickness skin graft for lining the neovagina is presented. Between 1985–1991 in our clinic, 46 patients were treated. A follow-up study has been performed and biopsies were taken from this neovagina; these showed normal vaginal mucosa.     

Gingival and mucosal reactions after intensive chlorhexidine gel treatment with or without oral hygiene measures

Abstract – The aim of this study was to elucidate whether soft tissue reactions during chlorhexidine (CHX) treatment might be associated with meticulous oral hygiene measures. A commercially available 1% chlorhexidine digluconate gel (Hibitane Dental Gel) was applied in a custom tray for the mandibular arch, 10 min daily, for 14 days. A split mouth approach was used to allow evaluation of the effect of oral hygiene measures with toothbrush, toothpaste, and dental floss on one side of the arch. During the treatment period, 8 out of 12 subjects developed gingival and/or mucosal reactions appearing as white patches or ulcerations. Both the gingival reactions on the buccal marginal gingiva and the mucosal reactions near the margin of the custom tray occurred only when the gel treatment was combined with meticulous oral hygiene measures. The white patches, which could easily be detached, leaving ulcerated areas, consisted entirely of stratified squamous epithelium. The findings suggest that intensive treatment with chlorhexidine gel, in individually fitted custom trays, combined with meticulous oral hygiene measures may induce toxic effects on the surface layers of the gingiva and mucosa.     

Brown tumor in normocalcemic child

Summary Brown tumor as the only and initial symptom of normocalcemic hyperparathyroidism in childhood is a very rare pathology. A 7-year-old girl with normocalcemic hyperparathyroidism and brown tumor of her mandible is presented.     

Urinary Excretion of I131-Diodrast Injected Intraventricularly in Communicating Hydrocephalus and Aqueduct Stenosis

Nine cases of expansive infantile hydro-cephalus were investigated by injecting Small amounts of I¹³¹-Diodrast intra-ventricularly. Urinary excretion of the tracer was determined during the first 4-5 hours after injection. The cumulative excretion of Diodrast from the C.S.F. differs in cases with communicating hydrocephalus from those with stenosis of the aqueduct. The investigation is rapid and easily performed and has not produced any side effects.