VH gene analysis of primary cutaneous B-cell lymphomas: evidence for ongoing somatic hypermutation and isotype switching

Primary cutaneous B-cell lymphomas are B-cell non-Hodgkin's lymphomas that arise in the skin. The major subtypes discerned are follicle center cell lymphomas, immunocytomas (marginal zone B-cell lymphomas), and large B-cell lymphomas of the leg. In this study, we analyzed the variable heavy chain (VH) genes of 7 of these lymphomas, ie, 4 follicle center cell lymphomas (diffuse large-cell lymphomas) and 3 immunocytomas. We show that all these lymphomas carry heavily mutated VH genes, with no obvious bias in VH gene usage. The low ratios of replacement versus silent mutations observed in the framework regions of 5 of the 7 lymphomas suggest that the structure of the B-cell antigen receptor was preserved, as in normal B cells that are selected for antibody expression. Moreover, evidence for ongoing mutation was obtained in 3 immunocytomas and in one lymphoma of large-cell type. In addition, in 1 immunocytoma, both IgG- and IgA-expressing clones were found, indicative of isotype switching. Our data provide insight into the biology of primary cutaneous B-cell lymphomas and may be of significance for their classification.     

Injection drug users' practices and attitudes toward intervention and potential for reducing the transmission of HIV

Miami is one of the major centers of illegal drug activity and has a significant proportion of AIDS cases among injection drug users (IDUs). Since Needle Exchange Programs (NEP) are illegal and therefore do not exist in the state of Florida, other strategies must play a large role in reducing the transmission of HIV among IDUs. In order to effectively communicate with IDUs about needle safety, it is necessary to understand the practices and culture of IDUs, including where and how the needle/syringes are obtained and used. Data from recent studies conducted in Miami and other local sites indicate that IDUs inject frequently, averaging more than 1,000 per year, per person. While the vast majority of IDUs feel it is very important to clean needles and to use a needle only one time, these sentiments are not always practiced. Furthermore, data indicate that the context where shooting takes place must be considered in the planning of HIV risk reduction interventions. These findings suggest the importance of understanding patterns of drug use, attitudes toward intervention, and the cultural context where risky behaviors occur. Although Needle Exchange Programs are illegal in Florida, intervention programs must still stress the importance of using only new needles, but since new needles cannot always be obtained, IDUs should be taught and motivated not to use contaminated drug paraphernalia.     

Successful treatment with fluconazole of protothecosis developing at the site of an intralesional corticosteroid injection

We report a case of cutaneous protothecosis treated successfully with oral fluconazole. Fluconazole appears to be an effective alternative to conventional drugs for the treatment of cutaneous protothecosis. Cutaneous protothecosis is an uncommon infection due to achlorophyllic, saprophytic, algae-like unicellular organisms of the genus Prototheca that occurs mainly in immunocompromised patients. To date there is no standard treatment regimen. Surgical excision, oral ketoconazole, intravenous amphotericin B alone or in combination with oral tetracycline have been reported to be effective in the management of protothecosis. We report a 55-year-old immunocompetent woman with cutaneous protothecosis which developed at the site of intralesional triamcinolone acetonide injection, who was successfully treated with oral fluconazole.     

Chromosomal localization of the human gene encoding the 51-kDa subunit of mitochondrial complex I (NDUFV1) to 11q13

The 51-kDa flavoprotein subunit of mitochondrial NADH:ubiquinone oxidoreductase (Complex I) [NADH dehydrogenase (ubiquinone), flavoprotein 1 (51 kDa); EC 1.6.5.3] plays an important role in the formation of the NADH-binding site and is believed to be the principal site of entry for electrons donated by NADH into the respiratory chain. Human cDNA fragments of the 51-kDa protein were generated by polymerase chain reaction and used to localize the gene (NDUFV1) for this subunit to 11q13 by two separate techniques. This region of the human genome is strongly implicated in a number of different forms of cancer.     

Evaluation issues in the Drake Chemical Workers Notification and Health Registry Study

The Drake Chemical Workers' Health Registry combined notification of workers about bladder cancer risk with access to a free program for screening and diagnosis. Evaluation of the project has given rise to several findings and new research questions. Findings in this article illustrate the following evaluation issues: 1) studying the combination of strategies that are most effective and cost effective to notify workers of their disease risks, 2) determining the realistic yield from strategies to gain participation in health screening and other protective services for notified workers, 3) identifying the notification strategies that were most effective for different kinds of participants, 4) using process evaluation to identify key activities for ensuring continued participation of cohort members in screening, and 5) examining the extent to which participants are willing to quit smoking to protect their health.     

Increased apoptosis accompanies neoplastic development in the human colorectum

A disturbance in the balance between cell proliferation and cell loss, or apoptosis, may underlie neoplastic development. Therefore, we determined spontaneous apoptotic and proliferative rates in normal, hyperplastic, adenomatous, and malignant colorectal epithelia. In paired sections, DNA strand breaks were detected using the terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling assay, and apoptotic cells were also identified in H&E-stained slides by morphological criteria. Cell proliferation, bcl-2, and p53 expression were analyzed using specific monoclonal antibodies. In normal mucosa, luminal epithelial cells demonstrated higher rates of apoptosis compared to cells in the proliferative zone. Neoplastic transformation was associated with a significant increase in rates of apoptosis and proliferation. However, apoptosis, but not proliferation, decreased at the adenoma-to-carcinoma transition coincident with expression of mutant p53. In carcinomas, both mutant p53 and bcl-2 protein levels were associated with attenuated apoptotic rates. In conclusion, apoptosis is an important regulator of growth in normal and neoplastic colorectal epithelia. Increased apoptosis and proliferation accompany neoplastic transformation, suggesting that an alteration in apoptotic rates is an important event in colorectal carcinogenesis. Furthermore, the imbalance in these processes found in carcinomas may facilitate tumor growth and progression.     

ACC Oxidase in Papaya Sections After Heat Treatment

The effect of heat treatment on 1-aminocyclopropane-1-carboxylate (ACC) oxidase in excised sections of papaya (Carica papaya L). ‘Kapoho’ fruit immersed in hot water baths was analyzed as kinetics of a set of consecutive reactions. Treatments were at 23, 28, 33, and 38°C which would be encountered during initial treatments of whole fruits during heating to fruit-center temperatures of 47°C and above. The response of ACC oxidase was considered as two consecutive reactions, one for production and one for degradation. Activation energies were compared to those reported at 43°C to 51°C. The implications of the analyses were confirmed by results for a whole-fruit hot-water dip.     

Role of Lean Tissue on the Formation of N-Nitrosothiazolidine in Raw Bacon

Lean tissue, separated from whole bacon, was found to contain the precursors for N-nitrosothiazolidine (NTHZ), a nitrosamine formed when cured meats are smoked during processing. Of the various treatments investigated, cure incorporation of sodium ascorbate and liquid smoke yielded the lowest NTHZ values.     

Family planning: an essential component of prenatal care

This nation's traditional approach to improving maternal and infant health has been prenatal care. But evidence is mounting that additional progress in reducing maternal and infant morbidity and mortality will depend, at least in part, on the care that a woman receives before she conceives. The studies reviewed in this paper indicate that increasing the interval between deliveries and preventing or delaying pregnancies among women at high risk could lower the rate of low birthweight (LBW). Since reducing the rate of unintended pregnancies would also reduce the number of pregnancies in women at high risk of LBW because of race, age, late or no prenatal care, and unhealthy behaviors, the prevention of unintended pregnancies would also reduce LBW. Unfortunately, prenatal care, as experienced by many women, devotes little attention to these family planning issues. Many women do not realize the importance of family planning to their own health and that of their children. Prenatal care providers should include instruction about the importance of pregnancy planning and encourage women to continue receiving health care between pregnancies. If the health of women and infants is to be improved, society must be willing to provide health services to women of reproductive age even when they are not pregnant.