Tommie Sue Tralka

Seroprevalence and Ethnic Differences in Helicobacter pylori Infection among Adults in the United States

The seroprevalence of Helicobacter pylori infection was examined in the adult US population and among different ethnic groups. Stored sera from 7465 adult participants in the first phase of the third National Health and Nutritional Examination Survey (1988-1991) were tested with a sensitive and specific IgG ELISA, to diagnose infection. Seroprevalence of H. pylori among all participants was 32. 5%. This increased with age, from 16.7% for persons 20-29 years old to 56.9% for those > or =70 years old. Age-adjusted prevalence was substantially higher among non-Hispanic blacks (52.7%) and Mexican Americans (61.6%) than among non-Hispanic whites (26.2%). After controlling for age and other associated factors, the odds ratios relative to non-Hispanic whites decreased for non-Hispanic blacks, from 3.9 (95% confidence interval [CI], 3.1-4.9) to 3.3 (95% CI, 2. 6-4.2), and for Mexican Americans, from 6.3 (95% CI, 4.8-8.3) to 2.3 (95% CI, 1.6-3.5). The high prevalence of H. pylori infection among non-Hispanic blacks and Mexican Americans is partially explained by other factors associated with infection.

Electron microscopic observations on formation of pulmonary metastases

The development of pulmonary metastases after local surgical control of malignant tumors has represented a major cause of treatment failure in a variety of neoplasms. The metastatic process has been a subject of considerable interest, investigation, and speculation for many years, but it remains as a poorly characterized and little understood phenomenon. The formation of blood-borne metastases is generally considered to involve several steps, including: (1) growth of a primary tumor with eventual shedding of viable malignant cells into the blood, either directly through vascular invasion or indirectly by lymphatic drainage; (2) transport of tumor cell emboli through the circulation to distant organs; (3) arrest of blood-borne malignant cells in distant vascular beds; (4) penetration of vascular walls by embolized tumor cells; and (5) growth of metastasized malignant cells in the parenchyma of target organs. Histologic investigations of the metastatic process were undertaken early [ 181. Various initial studies of experimental metastases in animal neoplasms indicated that once malignant cells shed from a primary tumor reach the venous circulation, they are carried to the capillary bed of target organs where the cells become arrested prior to invasion of the target organ parenchyma [ 11, 24,251. The initial attachment of circulating tumor cells to the capillary endothelium of distant organs has been regarded as a crucial step in metastasis [6, 131. Numerous investigations have suggested that circulating tumor cells embolize to target organs, where they arrest in vascular channels and attach to the endothelium prior to invading the surrounding tissue parenchyma [4, 5, 26, 271. Various workers have proposed that the attachment of embolized malignant cells to the vascular walls is largely dependent upon entrapment of the tumor embolus within a thrombus or fibrin meshwork [2, 8, 17, 28, 291. Such a thrombus might serve to stabilize the tumor emboli within the vessels until the cells are able to penetrate the endothehum and establish metastatic foci within the perivascular connective tissue. Despite active research efforts, there have been relatively small amounts of data concerning the mechanisms involved in the arrest of circulating tumor cells and their method of growth in metastatic sites [9, 16, 301. Recently, electron microscopic investigations have attempted to characterize events in metastasis formation through examination of embolic tumor cells arrested within vascular beds [12, 141. Jones and coworkers [12] investigated the sequence of events in experimental pulmonary metastases of the Walker 256 carcinosarcoma in rats, utilizing both electron microscopy and fibrin-specific immunofluorescence. These investigators demonstrated that after intravenous injection, tumor cells were arrested in pulmonary capillaries and were surrounded by a thrombus formed from ag-

A controlled analysis of the transjugular intrahepatic portosystemic shunt in liver transplant recipients

BACKGROUND The transjugular intrahepatic portosystemic shunt (TIPS) is an important treatment for complications of portal hypertension. As some authors have suggested that TIPS may facilitate liver transplantation technically, the objective of this study was to determine the impact of TIPS on the liver transplant operation and its outcome. METHODS The analysis was designed as a retrospective cohort study using a multicenter database. Fifty-five patients with TIPS were matched with 55 controls on the basis of 10 pretransplant laboratory, clinical, and demographic features. TIPS patients and control patients were compared with regard to duration of surgery, intraoperative blood product usage, liver and renal function, volume of ascites, survival, and hospital stay. For confirmatory purposes, a parallel analysis using linear regression methods was performed. RESULTS By matched analysis, TIPS patients had less ascites at surgery (mean 0.9+/-0.20 vs. 2.2+/-0.37 L, P=0.005) and a slightly shorter time from incision to cross-clamp (mean 2.1+/-0.10 vs. 2.5+/-0.15 hr, P=0.03). However, there were not significant differences for total operative time (mean 6.0+/-0.17 vs. 6.3+/-0.25 hr, P=1.00), blood product usage, or any other outcome variable. Regression analysis confirmed these results. CONCLUSIONS TIPS does not significantly impact the course of liver transplantation surgery. Therefore, preoperative portal decompression solely to facilitate liver transplantation is not an appropriate indication for TIPS.

Unusual Intranuclear Inclusions in Malignant Fibrous Histiocytoma: Presence in Primary Tumor

We describe previously unreported intranuclear inclusions in 2 cases of malignant fibrous histiocytoma. The inclusions were found in 2-10% of the tumor cells removed from the patients and in 2-10% of the cells examined in tumor tissue xenotransplanted in nude mice. By stereo electron microscopy the inclusions are closely packed undulating fibrils 18-23 nm in diameter. They are sometimes associated with fibrillary bodies. They closely resemble the inclusions reported in some animals inoculated with serum from patients with non-A non-B hepatitis; however, their nature at present is unknown.

Ultrastructural and tissue culture studies of a thymic lymphoma induced by persistent antigenic stimulation and immunosuppression

Ultrastructural and immunologic studies were done on a malignant T-cell lymphoma of a BALB/c mouse grown in tissue culture. The original tumor was induced by coincident persistent antigenic stimulation and chronic immunosuppression. The lymphoma cells grew in tissue culture in a biphasic pattern: lymphoid cells proliferated in suspension and histiocytic cells attached to the bottom of the culture flask. While the lymphoid cells retained their T-cell specificities, the differentiating histiocytic cells showed diminishing Theta-antigenic sites and finally lost such specificities entirely. It is suggested that the Theta-negative histiocytes may be “end cells” with a limited proliferation capacity, while lymphoid T-cells are proliferating stem cells with a certain differentiating potential. Differentiation towards histiocytes apparently occurs simultaneously with the loss of T-cell characteristics. Ein in der BALB/c Maus durch regelmäßige Rinderalbumininjektionen bei gleichzeitiger Azathiopringabe erzeugtes T-Zell Lymphosarkom wächst in der Kultur als permanente Lymphoblastenreihe mit partieller Theta-Antigenexpression an der Cytoplasmamembran. Bei fortlaufender Kultur kommt es zur Absiedlung von Zellen, die zu Phagocyten differenzieren und schließlich als Monolayer auf dem Boden der Kulturflasche wachsen. Mit zunehmender phagocytärer Ausdifferenzierung dieser Zellen nimmt ihre Oberflächen-Theta-Antigendichte ab bis zum vollständigen Fehlen bei differenzierten Phagocyten. Da Phagocyten eine begrenzte Überlebenszeit und Vermehrungsfähigkeit zeigen und sich nicht zu lymphoiden Zellen rückverwandeln, andererseits jedoch Suspensionskulturen von Lymphoblasten trotz wiederholter Entnahme von phagocytären Zellen diese laufend weiter absiedeln, wird angenommen, daß Theta-positive Lymphoblasten sich zu Theta-negativen Phagocyten umwandeln können.

Butyrate increases type-A and type-R virus-like particles in BKV-transformed hamster spleen cells.

Abstract A cell line derived from hamster spleen transformed by human papovavirus BK was adapted to grow in 5 mM butyrate. Ultrastructurally, the butyrate-adapted cells were found to contain large numbers of type-R and intracytoplasmic type-A virus-like particles (VLP). In contrast, the unadapted cells contained only rare VLP. Treatment of the unadapted cells with nontoxic and toxic concentrations of butyrate for 24 and 48 hr failed to induce VLP, indicating the importance of butyrate adaptation in the induction of VLP. The increase in type-R VLP was stable after removal of the adapted cells from butyrate; however, the increase in type-A VLP was not.