[Utilization of transcutaneous anesthetics during heart catheterization]

OBJECTIVES

Assess the efficacy of an anesthetic cream for cardiac catheterization.

PATIENTS AND METHODS

Percutaneous anesthesia was studied in a series of 100 consecutive patients undergoing cardiac catheterization. The anesthesia was composed with an eutetic mixture of local anesthetics and applied precisely over the puncture area in a randomized controlled study. After admission, patients were randomized into two groups: 50 patients received lidocaine infiltration and 50 patients received associated cream and infiltration. Percutaneous anesthesia was to be applied 2 hours before entering the operating room.

RESULTS

No complication developed with this cream combined with lidocaine infiltration. Serum concentration indicated very low levels which were very well tolerated. Patient comfort improved with the anesthetic cream-lidocaine infiltration association.

CONCLUSION

The use of an anesthetic cream is safe and effective, especially combined with lidocaine infiltration during cardiac catheterization. Cost is high and the association might be reserved for special indications (obesity, children).

Identification and functional analysis of hPRP17, the human homologue of the PRP17/CDC40 yeast gene involved in splicing and cell cycle control

The PRP17 gene of the yeast Saccharomyces cerevisiae encodes a protein that participates in the second step of the splicing reaction. It was found recently that the yeast PRP17 gene is identical to the cell division cycle CDC40 gene. The PRP17/CDC40 gene codes for a protein with several copies of the WD repeat, a motif found in a large family of proteins that play important roles in signal transduction, cell cycle progression, splicing, transcription, and development. In this report, we describe the identification of human, nematode, and fission yeast homologues of the PRP17/CDC40 gene of S. cerevisiae. The newly identified proteins share homology with the budding yeast protein throughout their entire sequence, with the similarity being greatest in the C-terminal two thirds that includes the conserved WD repeats. We show that a yeast-human chimera, carrying the C-terminal two thirds of the hPRP17 protein, is able to complement the cell cycle and splicing defects of a yeast prp17 mutant. Moreover, the yeast and yeast-human chimeric proteins co-precipitate the intron-exon 2 lariat intermediate and the intron lariat product, providing evidence that these proteins are spliceosome-associated. These results show the functional conservation of the Prp17 proteins in evolution and suggest that the second step of splicing takes place by a similar mechanism throughout eukaryotes.

Translating good will into good words

Physicians often are uncomfortable talking with patients about unfavorable diagnoses and advance care planning; patients, in turn, require reassurance, uncomplicated language and promises that their wishes will be respected. Steven Levy, M.D., discusses the steps providers should take in talking with patients at the end of life.

Amiodarone in atrial fibrillation

Oral amiodarone may be used in the prevention of recurrences of paroxysmal atrial fibrillation (AF) or in chronic AF following electrical cardioversion or for pharmacological cardioversion of AF. The use of amiodarone for rate control of AF is also discussed in this article. Recent reports have shown that low-dose amiodarone is effective in preventing recurrence following cardioversion, but there have been no long-term controlled or comparative studies to support this. Thus amiodarone is not recommended as a first-line drug for preventing recurrences of AF. Results on the use of amiodarone in the prevention of paroxysmal AF have been equivocal; this may be attributed to differences in defining paroxysmal AF. The use of low-dose amiodarone, alone or in combination with a class I agent, may be beneficial in patients with AF but long-term studies to determine the safety and efficacy of the drug are required.

Sequences and expression of six new members of the tetraspanin/TM4SF family

Tetraspanins (or TM4SF) are expressed in a wide variety of species and regulate cell adhesion, migration, proliferation and differentiation. We have identified and sequenced six new members of the tetraspanin family, called Tspan-1-6, from human cDNA. Amino acid sequence analysis of the Tspans highlights conserved residues which may be critical to tetraspanin structure and function. The Tspans are differentially expressed in human tissues.

CD81 (TAPA-1): a molecule involved in signal transduction and cell adhesion in the immune system

CD81 (TAPA-1) is a widely expressed cell-surface protein involved in an astonishing variety of biologic responses. It has been cloned independently several times for different functional effects and is reported to influence adhesion, morphology, activation, proliferation, and differentiation of B, T, and other cells. On B cells CD81 is part of a complex with CD21, CD19, and Leu13. This complex reduces the threshold for B cell activation via the B cell receptor by bridging Ag specific recognition and CD21-mediated complement recognition. Similarly on T cells CD81 associates with CD4 and CD8 and provides a costimulatory signal with CD3. In fetal thymic organ culture, mAb to CD81 block maturation of CD4-CD8- thymocytes, and expression of CD81 on CHO cells endows those cells with the ability to support T cell maturation. However, CD81-deficient mice express normal numbers and subsets of T cells. These mice do exhibit diminished antibody responses to protein antigens. CD81 is also physically and functionally associated with several integrins. Anti-CD81 can activate integrin alpha 4 beta 1 (VLA-4) on B cells, facilitating their adhesion to tonsilar interfollicular stroma. Similarly, anti-CD81 can activate alpha L beta 2 (LFA-1) on human thymocytes. CD81 can also affect cognate B-T cell interactions because anti-CD81 increases IL-4 synthesis by T cells responding to antigen presented by B cells but not by monocytes. The tetraspanin superfamily (or TM4SF) includes CD81, CD9, CD37, CD53, CD63, CD82, CD151, and an increasing number of additional proteins. Like CD81, several tetraspanins are involved in cell adhesion, motility, and metastasis, as well as cell activation and signal transduction.

Xlandscape: the graphical display of word frequencies in sequences

MOTIVATION

To provide a graphical interface for the generation, display and manipulation of a sequence landscape that will run on all X-windows-based Unix workstations.

RESULTS

The sequence landscape approach enables the representation of the frequency of occurrence of all query sequence sub-words within a database. The landscape approach can detect tandem and other repeating word motifs, specific sub-words that are over-represented words in a particular database using Markov probability and the preference for sub-words belonging to either one of two databases. All these features aid in the classification of a query sequence. Given the open-text format for sequences and databases, the Xlandscape tool can be applied to a wide range of problems.

CD81 on B cells promotes interleukin 4 secretion and antibody production during T helper type 2 immune responses

Mice lacking CD81 (TAPA-1), a widely expressed tetraspanin molecule, have impaired antibody responses to protein antigens. This defect is specific to antigens that preferentially stimulate a T helper 2 response (ovalbumin or keyhole limpet hemocyanin in alum) and is only seen with T cell-dependent antigens. Absence of CD81 on B cells is sufficient to cause the defect. Also, antigen-specific interleukin (IL) 4 production is greatly reduced in the spleen and lymph nodes of CD81-null mice compared with heterozygous littermates. Thus, expression of CD81 on B cells is critical for inducing optimal IL-4 and antibody production during T helper 2 responses. These findings suggest that CD81 may interact with a ligand on T cells to signal IL-4 production. By using a soluble form of CD81 as a probe, a putative ligand for CD81 was identified on a subset of B and T cells. Two possible models for the interaction of CD81 on B cells with a potential ligand on either B or T cells are proposed.

Long-term effects of cicletanine on secondary pulmonary hypertension

Cicletanine, a furopyridine-derivative drug, was shown to enhance the production of endogenous prostacyclin. The potent vasodilating properties of prostacyclin are used to treat severe primary pulmonary hypertension. Prostacyclin has a short half-life and can be administered only as an i.v. infusion. The aim of this study was to evaluate the effects of cicletanine on pulmonary artery hypertension (PAH) resulting from chronic obstructive lung disease (COLD). In a double-blind controlled study, we evaluated the effects of short- and long-term administration of cicletanine (50 mg daily, orally) on hemodynamics and blood gases of patients with PAH resulting from COLD. The initial dose of 50 mg of cicletanine had no effect. A significant decrease in the mean pulmonary artery pressure (15%) and in total pulmonary resistance (20%) was observed after 3 or 12 months of treatment in the cicletanine group (11 patients), when compared with placebo (12 patients). PaO2 decreased slightly in the cicletanine group, but the difference from the control group was not significant. These results suggest that long-term treatment with cicletanine can induce effective pulmonary vasodilation in patients with PAH caused by COLD and that this is probably responsible for a small venous admixture.

Gene organization and chromosome location of the neural-specific RNA binding protein Elavl4

We have isolated the gene that encodes the neural-specific RNA binding protein HuD in the mouse (Elavl4), and have mapped its location to the mid-distal region of chromosome 4, close to the neurological mutant clasper. The coding region of the Elavl4 gene covers approximately 44 kb; the first two RNA binding domains (RBDs) that are homologous to the two RBDs found in the Drosophila sex-lethal gene are each encoded in two exons, whereas the third RBD is encoded in a single exon. Elavl4 mRNAs are alternatively spliced in the region between RBDs 2 and 3 due to the variable use of two micro-exons, and RNase protection analysis indicates that two of four possible splice variants are the predominant isoforms expressed in the central nervous system. The high degree of sequence conservation between the Hu proteins suggests that the exon organization of all the Hu protein genes will be similar, if not identical, to the Elavl4 gene.

Idiotype vaccines for non-Hodgkin's lymphoma induce polyclonal immune responses that cover mutated tumor idiotypes: comparison of different vaccine formulations

The idiotype (Id) of the Ig expressed on the surface of non-Hodgkin's lymphoma cells is a suitable target for immunotherapy. Indeed, treatment with monoclonal anti-Id antibodies (Abs) can induce long-lasting clinical remissions. However, some of the treated patients relapse with a tumor expressing Ig with point mutations in the idio recognized by the particular monoclonal antibody (MoAb). The alternative approach of active immunization with tumor Id can cure the disease in mice with established tumors and is now being studied in clinical trials. Here, we tested the hypothesis that active immunization with the idiotype would evoke a polyclonal immune response that would cover mutated tumor variants. As a test system, we chose the tumor from a patient who had achieved a complete remission after therapy with anti-Id Ab but subsequently relapsed with a mutated tumor variant no longer binding the treatment Ab. Mice were immunized with proteins and genetic vaccines derived from the original tumor, including (1) Id-keyhole limpet hemocyanin protein, (2) Id single-chain variable fragment (scFv) granulocyte-macrophage colony-stimulating factor (GM-CSF) protein, (3) DNA encoding the Id, and (4) an adenovirus encoding the Id. All immunized mice developed a specific immune response detecting tumor-derived Id proteins from the original tumor and from all tumor variants. We conclude that active immunization with tumor Id can induce a polyclonal immune response and therefore may prevent the escape of mutated tumor variants.

DNA vaccination with cytokine fusion constructs biases the immune response to ovalbumin

DNA vaccination may work through direct transfection of antigen presenting cells (APC), or by secretion of the encoded protein by muscle or skin cells for uptake by APC. If cytokines are attached to the antigen, they may influence APC or responding T cells to drive the response toward a Th1 or Th2 direction, and/or potentiate it in an antigen-specific manner. To test this concept, expression vectors were constructed containing the ovalbumin (OVA) gene either alone, or linked to cytokine genes including GM-CSF, IFN-gamma, IL-2, IL-4, IL-12, or a sequence encoding nine amino acids of IL-1 beta. These constructs expressed OVA-cytokine fusion proteins in vitro which retained cytokine bioactivity. C57BL/6 mice were injected intramuscularly with the DNA constructs. Little if any OVA-specific antibody was produced in response to any of the DNA constructs, except for OVA-IL-4. However, lymphocytes from BALB/c mice vaccinated with OVA-IL-12 and OVA-IL-1 beta constructs produced more IFN-gamma and less IL-4 during in vitro restimulation assays than did other groups. All constructs elicited OVA-specific cytotoxic responses which were maintained or even increased over 16 weeks. The OVA-IL-12 and OVA-IL-1 beta peptide constructs elicited the strongest cytotoxic responses at 2 weeks postinjection. Cytotoxic responses were seen in all animals, even those lacking OVA-specific Ab, and were not related to Ab level. These studies indicate that the humoral, cytokine, and cytotoxic responses to DNA vaccination can be effectively altered by certain cytokine fusion constructs.

Orthotopic liver transplantation with preservation of portocaval flow compared with venovenous bypass

Conventional liver transplantation requires cross-clamping of the hepatic pedicle and inferior vena cava, leading to severe hemodynamic and metabolic disturbances, usually attenuated by the use of venovenous bypass. A more recent surgical technique, piggyback with temporary portocaval shunting, preserves both caval and portal blood flows. The aim of this study was to compare the two methods prospectively. Forty-four patients with chronic liver disease were studied. Local anatomic conditions guided the surgeon to choose the easiest way to remove the native liver. Anesthetic management was standardized. Hemodynamic and metabolic changes were assessed by use of routine tests at specific periods. Graft function was evaluated by measurement of aminotransferases and monoethylglycinexylidide (MEGX) test 12, 24, 48, and 72 hours postoperatively. Conventional liver transplantation with venovenous bypass was performed in 26 patients, and the piggyback with temporary portocaval shunting was performed in 15 patients. ANOVA showed that cardiac output and systemic oxygen delivery were better maintained before revascularization in the piggyback group. Metabolic changes were comparable, and hyperfibrinolytic activity was detected in both groups. Graft function was comparable and satisfactory within the 3 first postoperative days. Piggyback with temporary portocaval shunting provided better intraoperative hemodynamics and tissue oxygenation than liver transplantation with venovenous bypass.

Dose-ranging study of the clinical efficacy of twice-daily triamcinolone acetonide inhalation aerosol in moderately severe asthma

OBJECTIVES

This multicenter, double-blind, placebo-controlled study evaluated the dose response to 6 weeks of triamcinolone acetonide inhalation aerosol (TAA, 100 microg per puff) in patients with moderately severe asthma.

STUDY DESIGN

A total of 285 patients were randomly assigned to treatment with 1, 2, 4, or 8 puffs TAA (total daily doses of 200, 400, 800, and 1,600 microg, respectively), administered twice daily, or matching placebos. Efficacy was assessed by changes in FEV1, asthma symptom scores, albuterol use, and peak flow rates.

RESULTS

Linear trend analyses showed a dose response for all efficacy variables across the dose range of 200 to 1,600 microg daily. Therapeutic activity was evident at a dose of 200 microg daily for all variables, with significant clinical efficacy (p<0.05) demonstrated for all doses except for reduction in inhaled albuterol use which achieved statistical significance at 400 microg/d. Daily doses of 400 microg and higher showed response plateaus at 3 weeks of treatment that were maintained for the remainder of the trial. The incidence of adverse events was similar in all treatment groups, although more patients treated with TAA reported pharyngitis in a dose-related manner.

CONCLUSIONS

Our findings suggest that most patients with chronic, moderately severe asthma can be treated adequately with doses of TAA between 200 microg (1 puff bid) and 800 microg (4 puffs bid) daily. At this dose range, clinically significant improvements are evident in symptoms, pulmonary function, and rescue medication use.

Society for Healthcare Epidemiology of America and Infectious Diseases Society of America Joint Committee on the Prevention of Antimicrobial Resistance: guidelines for the prevention of antimicrobial resistance in hospitals

Antimicrobial resistance results in increased morbidity, mortality, and costs of health care. Prevention of the emergence of resistance and the dissemination of resistant microorganisms will reduce these adverse effects and their attendant costs. Appropriate antimicrobial stewardship that includes optimal selection, dose, and duration of treatment, as well as control of antibiotic use, will prevent or slow the emergence of resistance among microorganisms. A comprehensively applied infection control program will interdict the dissemination of resistant strains.

Biochemical, histomorphometric and densitometric changes in patients with multiple myeloma: effects of glucocorticoid therapy and disease activity

It is unknown whether bone changes which can occur in multiple myeloma (MM) are due to cytokine-induced osteoclastic bone resorption from a clone of abnormal plasma cells or high-dose glucocorticoid therapy. We studied 25 MM patients treated for 1-12 years with combination chemotherapy, subdivided into two groups. Group 1 consisted of 12 patients with stage I and II myeloma and group 2 consisted of 13 patients with stage III MM. Their serum biochemistry, tetracycline-labelled bone histomorphometry and bone densitometry were compared to age- and sex-matched controls. Patients with MM demonstrated increased indices of bone resorption (P < 0.001 versus controls) and, to a lesser extent, increased indices of bone formation (P < 0.01 versus controls). No patient had evidence of a mineralization defect. Lumbar spine, femoral neck and total body bone mineral density measurements (BMD) were significantly lower in group 2 compared with group 1 (P < 0.05). Following 12 months of therapy, lumbar spine BMD decreased by 6.6% (95% CI, 2.7% to -9.3%) and femoral neck BMD decreased by 9.5% (95% CI, -3.2% to -15.9%). In a stepwise regression analysis, cumulative prednisolone dosage (B Coef. = -0.39; P = 0.03) and plasma cell infiltrate (B Coef. = -0.08; P = 0.05) were the most important predictors of lumbar spine bone loss, whereas serum paraprotein (B Coef.= -0.35; P = 0.02) and plasma cell infiltrate (B Coef. = -0.20; P = 0.04) were the most important predictors of femoral neck bone loss. We conclude that MM is characterized by high bone turnover with osteoblast-osteoclast uncoupling. Both disease activity and high-dose glucocorticoid therapy may be responsible for the ongoing bone loss seen with MM.

Applications of S-layers

The wealth of information existing on the general principle of S-layers has revealed a broad application potential. The most relevant features exploited in applied S-layer research are: (i) pores passing through S-layers show identical size and morphology and are in the range of ultrafiltration membranes; (ii) functional groups on the surface and in the pores are aligned in well-defined positions and orientations and accessible for binding functional molecules in very precise fashion; (iii) isolated S-layer subunits from many organisms are capable of recrystallizing as closed monolayers onto solid supports at the air-water interface, on lipid monolayers or onto the surface of liposomes. Particularly their repetitive physicochemical properties down to the subnanometer scale make S-layers unique structures for functionalization of surfaces and interfaces down to the ultimate resolution limit. The following review focuses on selected applications in biotechnology, diagnostics, vaccine development, biomimetic membranes, supramolecular engineering and nanotechnology. Despite progress in the characterization of S-layers and the exploitation of S-layers for the applications described in this chapter, it is clear that the field lags behind others (e.g. enzyme engineering) in applying recent advances in protein engineering. Genetic modification and targeted chemical modification would allow several possibilities including the manipulation of pore permeation properties, the introduction of switches to open and close the pores, and the covalent attachment to surfaces or other macromolecules through defined sites on the S-layer protein. The application of protein engineering to S-layers will require the development of straightforward expression systems, the development of simple assays for assembly and function that are suitable for the rapid screening of numerous mutants and the acquisition of structural information at atomic resolution. Attention should be given to these areas in the coming years.

An ovalbumin-IL-12 fusion protein is more effective than ovalbumin plus free recombinant IL-12 in inducing a T helper cell type 1-dominated immune response and inhibiting antigen-specific IgE production

Optimal treatment of allergic diseases requires that the cytokine profile of allergen-specific T cells be redirected, with the conversion of Th2 profiles into Th1 cytokine profiles. This conversion, however, is difficult, since Th2 effector cells have relatively fixed cytokine profiles. To more effectively redirect the cytokine profiles of T cells, we constructed a cytokine fusion protein that contained the Ag OVA, fused to IL-12. Immunization with the OVA-IL-12 fusion protein induced anti-OVA IgG2a Ab and large quantities of OVA-specific IFN-gamma production. The Ag specificity of this response was dependent upon covalent linkage of Ag and IL-12, since immunization of mice with OVA alone induced little or no IFN-gamma, while immunization with OVA and free rIL-12 enhanced T cell production of IFN-gamma, but the IFN-gamma production was not OVA specific. To examine the effects of OVA-IL-12 in reversing ongoing Th2-dominated immune responses, BALB/c mice previously primed with OVA in alum to induce a Th2-dominated response, were vaccinated with the OVA-IL-12 protein. In such mice, OVA-IL-12 was much more effective than OVA plus free rIL-12 in significantly increasing Ag-specific IFN-gamma production and significantly decreasing Ag-specific IL-4 production. Moreover, OVA-IL-12 increased serum anti-OVA IgG2a and decreased anti-OVA IgE. These studies indicate that OVA-IL-12 can convert immune responses characterized by high IL-4 and high IgE synthesis into Th1-dominated responses in an Ag-specific manner.

The tetraspanin superfamily: molecular facilitators

A legacy of molecular evolution is the formation of gene families encoding proteins that often serve related functions. One such family gaining recent attention is the tetraspanin superfamily, whose membership has grown to nearly 20 known genes since its discovery in 1990. All encode cell-surface proteins that span the membrane four times, forming two extracellular loops. Some of these genes are found in organisms as primitive as schistosomes and nematodes. Alternately known as the transmembrane 4 (TM4) superfamily or the TM4SF, 4TM, or tetraspan family, we propose here that the name tetraspanins be used for the purpose of standardization. What do the tetraspanins do? Awaiting definitive functional studies, we can only put together pieces of a puzzle that has been built by raising antibodies against these proteins and looking at their distribution, associations, and functions. A brief overview indicates that some tetraspanins are found in virtually all tissues (CD81, CD82, CD9, CD63), whereas others are highly restricted, such as CD37 (B cells) or CD53 (lymphoid and myeloid cells). Many of these proteins have a flair for promiscuous associations with other molecules, including lineage-specific proteins, integrins, and other tetraspanins. In terms of function, they are involved in diverse processes such as cell activation and proliferation, adhesion and motility, differentiation, and cancer. We propose that these functions may all relate to their ability to act as "molecular facilitators," grouping specific cell-surface proteins and thus increasing the formation and stability of functional signaling complexes.

An ovalbumin-IL-12 fusion protein is more effective than ovalbumin plus free recombinant IL-12 in inducing a T helper cell type 1-dominated immune response and inhibiting antigen-specific IgE production

Optimal treatment of allergic diseases requires that the cytokine profile of allergen-specific T cells be redirected, with the conversion of Th2 profiles into Th1 cytokine profiles. This conversion, however, is difficult, since Th2 effector cells have relatively fixed cytokine profiles. To more effectively redirect the cytokine profiles of T cells, we constructed a cytokine fusion protein that contained the Ag OVA, fused to IL-12. Immunization with the OVA-IL-12 fusion protein induced anti-OVA IgG2a Ab and large quantities of OVA-specific IFN-gamma production. The Ag specificity of this response was dependent upon covalent linkage of Ag and IL-12, since immunization of mice with OVA alone induced little or no IFN-gamma, while immunization with OVA and free rIL-12 enhanced T cell production of IFN-gamma, but the IFN-gamma production was not OVA specific. To examine the effects of OVA-IL-12 in reversing ongoing Th2-dominated immune responses, BALB/c mice previously primed with OVA in alum to induce a Th2-dominated response, were vaccinated with the OVA-IL-12 protein. In such mice, OVA-IL-12 was much more effective than OVA plus free rIL-12 in significantly increasing Ag-specific IFN-gamma production and significantly decreasing Ag-specific IL-4 production. Moreover, OVA-IL-12 increased serum anti-OVA IgG2a and decreased anti-OVA IgE. These studies indicate that OVA-IL-12 can convert immune responses characterized by high IL-4 and high IgE synthesis into Th1-dominated responses in an Ag-specific manner.