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A Cramer

Publications and source records attributed to A Cramer.

11 recordsLinked to original sources
PubMed1991

Somatostatin analogues inhibit angiogenesis in the chick chorioallantoic membrane.

The mechanism responsible for alterations in tumor growth following administration of somatostatin analogues is unknown. Somatostatin analogues, SMS 201-995 and RC-160, have demonstrated the potential to inhibit both tumor growth and vascularity, in vivo and in vitro. We hypothesized that SMS and RC-160 inhibit angiogenesis and this inhibition may alter tumor growth. To test this hypothesis, 2 mm methylcellulose disks containing concentrations of SMS 201-995 and RC-160 at 0, 0.5, 2.5, or 50 micrograms per disk, were implanted on the chorioallantoic membrane (CAM) of 6- to 7-day-old shell-less chick embryos. Inhibition of blood vessel growth in the region of the disk was visually assessed 24-36 hr following disk implantation and graded (0-4) based on the radius of the zone of inhibition from the center of the disk. The overall incidence of inhibition for the somatostatin analogues at concentrations of 0.5, 2.5, and 50 micrograms per disk was 13, 56, and 61% for SMS and 27, 49, and 68% for RC-160, respectively. Overall incidence of inhibition for the positive (inhibitory) control was 70.5% and those for buffer (negative) controls were 3-14%. Somatostatin analogues were associated in a dose-related fashion with both a greater percentage of inhibition of blood vessel growth and an increased grade of inhibition. Inhibition of angiogenesis may be a mechanism responsible for the tumor regression observed in vivo following SMS or RC-160 therapy.

Allantois↗
PubMed1982

Immunoblastic sarcoma: morphologic criteria and the distinction of B and T cell types.

Immunologic concepts have facilitated the recognition within the histiocytic lymphoma group of the Rappaport classification of five diagnostic categories of lymphoma (follicular center cell lymphoma large cleaved and large non-cleaved types, immunoblastic sarcoma B cell type, immunoblastic sarcoma T cell type and 'true histiocytic lymphoma'). The first four of these 'large cell lymphomas' are closely related biologically and are difficult to distinguish histologically. This paper purports to examine the morphologic criteria employed in the differential diagnosis of these four large cell lymphomas in an objective manner, utilizing carefully prepared histologic sections from 24 cases of lymphoma that had been subjected to detailed B and T cell characterization by surface marker methods. 18 morphologic criteria were evaluated by four observers independently. The results show that reliable histologic distinctions can be made on histologic grounds in a proportion of cases only and that individual criteria show more overlap within diagnostic criteria than previously recognized. This is attributed in part to the close biologic relationship of these neoplasms. It is also recognized that the morphologic criteria are subtle and that the pathologist should have the advantage of auxiliary techniques--cytochemistry, immunohistology, surface marker techniques--to achieve reliable distinction of functional types within the diffuse histiocytic group of Rappaport.

B-Lymphocytes↗
PubMedDate not supplied

An in vitro evaluation of the marginal integrity of a porcelain inlay system.

There is currently no consensus of opinion regarding form of the finish line for porcelain inlays. This study compared beveled and nonbeveled finishing lines. Twenty-four Class II MOD cavities of a standardised design were prepared in extracted premolar teeth. Twelve were finished using a half enamel occlusal bevel and 12 were not beveled. Porcelain inlays were fabricated and luted with a dual-polymerizing resin material. The completed restorations were stored in water, thermocycled, and analysed using a scanning electron microscope. The quality of the enamel/composite resin interface was found to be considerably better than that of the inlay/composite resin interface. The adaptation of composite resin to enamel was of equal quality for both beveled and nonbeveled preparations.

Composite Resins↗