Mycosis fungoides in relation to environmental exposures and immune response: a case-control study.

Mycosis fungoides is a cutaneous T-cell lymphoma of unknown etiology, thought to be a rare sequela of chronic antigenic stimulation that may occur, for example, with exposure to contact allergens. To explore this possibility, we interviewed 174 patients with mycosis fungoides and 294 randomly selected control subjects in the San Francisco, Los Angeles, and Seattle areas concerning their lifetime histories of employment, chemical exposures, allergy, atopy, and certain medical conditions. Patients reported higher prevalence of cancers other than the non-Hodgkin's lymphomas and skin cancers (relative risk = 3.3, P less than .001) and were more likely than controls to burn when exposed to the sun (for nonblacks, relative risk = 1.7, P = .01). The latter difference may reflect a manifestation rather than a precursor of the disease. We found no consistent or biologically plausible differences between patients and controls with respect to types of jobs held, or to occupational or vocational exposures to chemicals. These findings do not support the hypothesis that persistent antigenic stimulation by contact allergens is etiologically important in the pathogenesis of mycosis fungoides.

Predicting the functional consequences of non-synonymous single nucleotide polymorphisms: structure-based assessment of amino acid variation.

We have developed a formalism and a computational method for analyzing the potential functional consequences of non-synonymous single nucleotide polymorphisms. Our approach uses a structural model and phylogenetic information to derive a selection of structure and sequence-based features serving as indicators of an amino acid polymorphim's effect on function. The feature values can be integrated into a probabilistic assessment of whether an amino acid polymorphism will affect the function or stability of a target protein. The method has been validated with data sets of unbiased mutations in the lac repressor and lysoyzyme. Applying our methodology to recent surveys of genetic variation in the coding regions of clinically important genes, we estimate that approximately 26-32 % of the natural non-synonymous single nucleotide polymorphisms have effects on function. This estimate suggests that a typical person will have about 6240-12,800 heterozygous loci that encode proteins with functional variation due to natural amino acid polymorphism.

Retrovirus-mediated gene transfer into canine thyroid using an ex vivo strategy.

We describe studies in a canine model aimed at establishing methods for ex vivo gene delivery to thyroid follicular cells. Canine follicular cells were harvested from tissue obtained by unilateral lobectomy, grown in thyrotropin-containing media, and transduced with amphotropic retroviral vectors carrying Escherichia coli beta-galactosidase or Tn7 neomycin-resistance genes. Up to 30% of cells were transduced with retroviral vectors containing the neomycin resistance gene, and transduced cells could be selected with G418. Significantly, transduced and selected cells exhibited the morphology of thyroid follicular cells and continued to express thyroglobulin. To assess the viability of cultivated and transduced cells for transplantation, cells were stained with the vital fluorescent dye DiI, recovered by trypsinization, and transplanted into the contralateral thyroid lobe of autologous animals. Engraftment was demonstrated by fluorescence microscopy and identification of proviral sequences 7-10 days after transplantation. Proviral transcripts were evident using coupled reverse transcription and the polymerase chain reaction using total RNA from transplanted glands. Thyroid follicular cells may represent an attractive target for gene therapy due to their proliferative potential, their large protein synthetic and secretory capacity, and their susceptibility to regulation. The thyroid might be a target for therapy of congenital or acquired thyroid diseases as well as disorders requiring regulated expression of proteins in the circulation. This work demonstrates the feasibility of ex vivo gene delivery to thyroid follicular cells that may be used in future investigations.

Multiple domain protein diagnostic patterns.

We have implemented an iterative algorithm for the identification of diagnostic patterns from sets of multiple-domain proteins, where domains need not be common to all the proteins in the defining set. Our algorithm was applied to sequences gathered using a variety of methods, including BLAST, common keywords, and common E.C. numbers. In all cases, useful diagnostic patterns were obtained, possessing both high sensitivity and specificity. The patterns were found to correlate in several cases with both functional and structural domains. Patterns generated from a large number of sequence families were analyzed for probable multiple-domain structure.

Allergic contact dermatitis: novel immunohistologic features.

Leu-8 is a novel antigen expressed by the majority of mature T cells and certain other cells. Recent studies of the allogeneic mixed leukocyte reaction indicate that both Leu-8+ and Leu-8- subsets of Leu-3+ T cells have important functions in cell-mediated immunity in vitro. In order to determine whether Leu-3+8+ and/or Leu-3+8- T cells are present in cell-mediated immune reactions in vivo, we studied the immunohistology of allergic contact dermatitis in 8 biopsies from 8 patients with positive patch tests and 3 biopsies from 2 patients with Rhus dermatitis. Both Leu-3+8+ and Leu-3+8- T cells were present in each biopsy. Only 1 case had a definite minority of the Leu-3+8+ subset. These results suggest that, analogous to in vitro systems, both Leu-8+ and Leu-8- subsets of Leu-3+ T cells are involved in cell-mediated immunity in vivo. HLA-DR+ keratinocytes were present in only 3 of 11 biopsies at days 3-7. No HLA-DQ+ keratinocytes were identified. We also confirmed prior findings that Leu-3+ cells are the predominant T-cell population, Langerhans cells are increased, and B cells and NK cells are rare. Furthermore, Tac and Ki-67 expression by T cells and Leu-3 expression by Langerhans cells tended to increase over time.

Effective cryopreservation and long-term storage of primary human hepatocytes with recovery of viability, differentiation, and replicative potential.

Despite reports of successful cryopreservation of primary human hepatocytes, existing methods do not produce sufficient recovery of viable cells to meet the needs of basic research or clinical trials of hepatocellular transplantation. We now describe a protocol for efficient cryopreservation of primary human hepatocytes using University of Wisconsin (UW) solution, fetal bovine serum, and dimethyl sulfoxide (DMSO). This method provides > 90% viability of differentiated, primary human hepatocytes 8 mo after cryopreservation as measured by trypan blue exclusion, preserves hepatocyte morphology, liver-specific gene expression (alpha 1 antitrypsin), and replication. The effectiveness of UW solution as a cryopreservative agent suggests that metabolic as well as ultrastructural factors may be important in the effective cryopreservation of primary human hepatocytes. The present method represents an effective protocol for cryopreserving differentiated primary human hepatocytes for research. This method may allow characterization and banking of human hepatocytes for clinical applications, including hepatocellular transplantation and hepatic assist devices.

Electrophilic 18F from a Siemens 11 MeV proton-only cyclotron.

Because more and more PET centres are using small proton cyclotrons there is a renewed interest in methods for the production of electrophilic 18F by proton irradiation of [18O]O2. A method for the routine production of clinically useful quantities of [18F]F2 having a specific activity of 35 Ci/mmol has been developed and implemented using an 11 MeV proton cyclotron and [18O]O2. Based on the yield, purity, reproducibility, and specific activity of [18F]F2 this is the most efficient method reported thus far.

Gene transfer into human thyroid follicular cells.

The authors established a means of effective gene transfer into human thyroid follicular cells via retroviral-mediated mechanisms. Using specific harvest and culture techniques, we investigated the selection of human thyroid cells in serum-free media. Normal adult human thyroid tissue was obtained after thyroidectomy from fresh specimens sent for frozen-section analysis. Follicular cells were harvested and grown in hormonally defined, serum-free media to prevent fibroblast growth with selection for differentiated function assessed by immunohistochemical staining for thyroglobulin. The efficiency of gene transfer into human thyroid cells was compared between the zen-beta-gal and LNL6 retroviral vectors. The zen-beta-gal retrovirus encodes the product beta-galactosidase, and gene expression was demonstrated by histochemical staining in 0.1% to 1% of the cells. An improved efficiency of 2% to 3% transduction was demonstrated using the LNL6 vector which carries the gene for neomycin resistance (NEO-R). Polymerase chain reaction (PCR) identification of the integrated proviral sequence (NEO-R gene) with Southern blot confirmation was used to quantitate LNL6 transductions and compare confluent versus actively dividing cell cultures. Follicular cell gene therapy has significant potential for treating congenital or acquired diseases of the thyroid as well as disorders of circulating proteins such as diabetes, hypopituitarism, and hemophilia. The ability to culture human follicular cells and perform effective gene transfer is paramount in the eventual realization of thyroid gene therapy.

Depressive symptoms by self-report in adolescence: phase I of the development of a questionnaire for depression by self-report.

As the first step in validating a criteria-based, self-report depression questionnaire specifically for children and adolescents and to determine the prevalence of self-reported depressive symptoms, we studied 3,294 high school students of mixed ethnic background in a large urban school district. They completed the Weinberg Screening Affective Scale. The 21-item Beck Depression Inventory was also completed to allow comparison with a previous study. The prevalence of clinically significant depressive symptoms suggesting depression by self-report ranged from 18% on the Beck Depression Inventory to 13% on the Weinberg Screening Affective Scale. Hispanic females had the highest scores, while white males had the lowest. Being behind in school, female, and nonwhite predicted more self-reported depressive symptoms.

Medicolegal aspects of occupational skin diseases.

Skin diseases, including chemical burns, are the most frequently reported of all occupational illnesses. More than 90 per cent of work-related dermatologic problems are contact dermatitis, and there is rarely anything about the location and appearance of these lesions to differentiate clearly from a dermatitis of nonoccupational origin. A complete and time-consuming history must therefore be taken, including documentation of nonwork activities.

The dermatologist and workers' compensation. Theory and practice.

Workers' compensation law is poorly understood by many physicians, including dermatologists. The tenets of this law throughout the country are basic and fairly straight forward, and the most important of them are nearly the same for all of the states. By understanding how the law operates and what is required of physicians, helping patients with their work-related dermatoses can be a gratifying experience.

Reactions to thimerosal in hepatitis B vaccines.

Hypersensitivity to thimerosal in vaccines has been reported to induce persistent local reactions, urticarial and generalized exanthematic eruptions, and, in the case of the hepatitis B vaccine, urticaria with asthma. The authors describe two cases of extensive reactions, one in a patient who did not form antibodies to the principal vaccine antigen. Although not all thimerosal-sensitive patients develop adverse reactions to vaccines containing this material, there is a potential risk, and the reactions can be very long lasting.

Alstroemeria. A new and potent allergen for florists.

Alstroemeria (Peruvian or Inca lily) has found particular favor because of its beauty and durability. However, it may induce a dermatitis so severe that workers have to change jobs. The dermatitis is chronic, with fissuring at the tips of the fingers bilaterally. Itching is often a less prominent symptom. Preventative measures are of little benefit, and many floral shops are vanishing the plant.

Hand eczema: the atopic subject and work.

Of the large number of young persons entering the work force each year, few choose their work with more than cursory consideration of their physical ability to perform it. This is especially true of atopic persons. When the first manifestation of the disease is hand eczema triggered by the first work experience, often after the subject has undergone many months of training, the answer becomes very difficult. It often requires a job change, with accompanying economic and personal loss. When the work is responsible for aggravation or activation of the condition, the entire gamut of social services comes into play, including medical, legal, rehabilitation, and workers compensation. These lead, after months and often years, to job changes that may or may not alleviate or ameliorate the condition. For these reasons dermatologists need to have greater awareness of the position of the atopic subject in the workplace.

Skin conditions of musicians.

Although skin conditions among musicians are uncommon, when they do occur, they may cause considerable discomfort and disability. The pattern of the condition very often indicates the instrument played.

A nonextraction approach to crowded dentitions in young children: early recognition and treatment.

A total of 22 cases that were diagnosed as having space discrepancy problems in the deciduous and early mixed dentitions showed that treatment by early expansion therapy with Crozat appliances had eliminated the need for extraction of deciduous canines or permanent premolars.