Strong opioids and non-cancer chronic pain in Catalonia. An analysis of the family physicians prescription patterns. / Opioides fuertes y dolor crónico no oncológico en Cataluña. Análisis del patrón de prescripción por parte de los médicos de familia.

OBJECTIVE: To identify family doctor prescription patterns for strong opioids for chronic, non-cancer-related pain. MATERIALS AND METHODS: Design A descriptive study based on a self-administered email questionnaire. LOCATION: All primary health care centres in Catalonia. PARTICIPANTS: 3,602 family doctors, all members of the Catalan Society of Family and Community Medicine. INTERVENTIONS: Email survey of Catalan family doctors. MAIN MEASUREMENTS: Demographic data, number of patients treated with potent opioids for chronic non-cancer pain, type of opioid used and indications, prescribing patterns and relationship with the Pain Management Unit. RESULTS: A total of 551 answers were obtained from 3,602 questionnaires sent (response rate of 15.3%), in which 480 physicians (87%) prescribed strong opioids for musculoskeletal pain, 268 (48.6%) prescribed ultra-rapid fentanyl and 434 (78.7%) reduced benzodiazepines dosage when prescribing potent opioids. The most common adverse effects were constipation and nausea. The main problems related with opioid prescription were improper use (341, 71%) and patient and/or practitioner reluctance (87, 18.1%). The assessment of the relationship with Pain Management Units was 2±1 (on a 1 to 5 scale), with communication (271, 52.2%) and accessibility (141, 27.1%) being the areas most in need of improvement. CONCLUSIONS: Opioid prescribing patterns generally follow clinical guidelines (e.g. reduction of benzodiazepine use or dose titration). However, there are some areas of improvement, such as sparse use of laxatives or use of ultra-rapid opioids for unapproved indications and in patients with no background opioid therapy. Family doctors perceive patient reluctance to adhere to the prescribed treatment, and call for specific training and better relationships with Pain Management Units.

The use of Salmonella schottmulleri for mapping and separation of human lymphocyte subpopulations.

Human lymphocyte subpopulations (B cells, B1, B2, T1, T2, T3, and T4 cells; our denomination) have been previously identified and isolated by bacterial adherence and functional differences between them have been demonstrated. Here we examined the binding properties of Salmonella schottmulleri to human lymphocytes in peripheral blood smears and found that it binds to more lymphocyte subpopulations, namely B, T1, T2 and T3 cells, than any bacteria previously tested. Thus, using only four bacteria: Salmonella schottmulleri, Brucella melitensis, Arizona hinshawii and Bacillus globigii we identified in blood smears B cells, two B and four T cell subpopulations. When we used gelatin-coupled monolayers of Sal. schottmulleri to isolate lymphocyte subpopulations, we showed that the nonadherent (T4) cells could be efficiently separated from the adherent cells. Furthermore, we tested the isolated subpopulations for natural killing (NK) activity and for antibody-dependent cell-mediated cytotoxicity (ADCC). Using both NK and ADCC assays, we observed a significantly higher cytotoxic activity in the nonadherent cell population than in the unseparated or adherent cell populations. Also the nonadherent cells contained most of the lymphocytes that have receptors for the Fc portion of IgG and those cells described as large granular lymphocytes. We concluded that Sal. schottmulleri is a valuable new reagent for the identification and separation of human lymphocyte subpopulations.

Circannual variations in the B cell/T cell ratio in normal human peripheral blood.

In previous studies we have shown that B cells and subpopulations of T cells can be identified in blood smears with bacteria used as markers that bind spontaneously to lymphocytes. We have also identified Ig-bearing cells by using an Escherichia coli coated with anti-human Ig antibody. Here we determined the absolute values and the percentage of B cells and of other lymphocyte subpopulations in the peripheral blood of six normal donors every 2 mo for 1 yr. we found that the total leukocyte counts and the total number of lymphocytes remained unchanged throughout the year, whereas the percentage of B cells in the coldest month was at almost twice the level observed in summer. The percentage of cells that bind Arizona hinshawii ans Salmonella schottmülleri remained practically unchanged during the entire year. A variation was noted in the ratio between T1 and T2 cells, which also appears to be seasonally related. We speculate that hormonal factors, probably corticosteroids, are responsible for changes in the traffic of some lymphocyte subpopulations.

Factors affecting the differential counting of human lymphocyte subpopulations in blood smears.

We have previously used the antibody-mediated binding of bacteria to identify Ig-bearing cells and the natural binding of bacteria to identify several lymphocyte subpopulations. By using bacteria this identification can be carried out in conventional blood smears since bacteria are small and easily distinguished from all blood elements. To develop a standardized method for identification of lymphocyte subpopulations that may become useful in clinical laboratories, we investigated here several parameters that might affect the safety and accuracy of the test, and that might simplify the procedure. We found that: (1) the rosettes formed between bacteria and lymphocytes cannot be disrupted by vigorous handling; (2) the ability fo form rosettes is a stable property of the bacterial strains; (3) for optimal results the blood sample must not be stored for more than 4 hr at 25 degrees C and the entire procedure must be performed in medium supplemented with 6% bovine serum albumin; (4) a large excess of anti-Ig antibody is required for the optimal coating of bacteria to detect Ig-bearing cells; (5) both the antibody-coated bacteria and formaldehyde-fixed bacteria can be stored at 4 degrees C or at -20 degrees C for at least 6 months; (6) the buffy coat from the blood sample can be used instead of the whole blood to reduce the time required for reading the smears; and (7) some of the pathogenic bacteria can be killed by autoclaving without modifying their binding properties. A complete and simple method which uses the bacterial adherence for the identification of lymphocyte subpopulations in blood smears is presented.

Relationship between bacterial binding to lymphocytes and clinical features in chronic lymphocytic leukemia.

In previous studies we showed that spontaneous bacterial adherence can be used to identify human lymphocyte subpopulations and to demonstrate variable binding patterns in chronic lymphocytic leukemia (CLL). In this study, 10 strains of bacteria of different genera and species were used in blood smears from 24 CLL patients to determine the percentages of lymphocytes that bind bacteria. From these percentages, binding indices were calculated. The symptoms and other laboratory tests were independently recorded and the stages determined. When the two sets of data were compared, relatively low binding indices were found in symptomatic patients or in Stages III and IV; relatively high binding indices were found in asymptomatic patients or in Stages I and II. We suggest that with progression of leukemia, lymphocytes with less "lectin" recognition potential are selected and escape any control mechanism of proliferation.

Binding of bacteria from the genus Brucella to human B lymphocytes.

In previous studies, we have shown that various lymphocyte subpopulations bind different strains of bacteria of different genera and species. Among these bacteria was a strain of Brucella melitensis which bound to all human B lymphocytes. To determine whether the binding of B. melitensis to human B lymphocytes was strain, species, or genus characteristic, we tested the binding of B. melitensis, Brucella abortus, Brucella ovis, Brucella suis, Brucella canis and Brucella neotomae to human normal and leukemic B lymphocytes. The binding of different Brucella species to B lymphocytes was determined by single- and double-labeling experiments in which a strain of Escherichia coli, coated with anti-light chain antibodies, was used as a marker for B cells. As in previous experiments, we found that B. melitensis and antibody-coated E. coli bound to the same cells. Also, we found that all the other species of bacteria tested bound to the B lymphocytes, normal or leukemic. B. ovis and B. neotomae, which are not human pathogens, bound to fewer B lymphocytes than did the human pathogens B. abortus, B. melitensis, B. suis, and B. canis. Furthermore, we found that the quality of rosettes formed by the nonpathogenic bacteria with the lymphocytes, i.e., the number of bacteria per lymphocytes, was lower than that of pathogenic Brucella species. We conclude that all of the Brucella species tested have the ability to bind to human B lymphocytes, but that only those which are human pathogens bind firmly to all B lymphocytes and may be used as reliable markers for these cells. We also suggest that the binding of Brucella species to B lymphocytes may have some bearing on the pathogenesis of brucellosis in humans.

The use of mutants of Escherichia coli for the identification of human lymphocyte subpopulations in blood smears.

In previous work we have shown that some bacteria can bind to human lymphocytes and can be used to identify lymphocyte subpopulations in conventionally stained blood smears. These bacteria are of different species or genera, which makes it difficult to study the binding mechanism. Also, the main marker for B cells, Brucella melitensis, is of very small size and highly pathogenic. Here we show that B cells as well as some of the T cell subpopulations can be identified by different mutants obtained from a strain of an Escherichia coli. Two procedures were used to generate mutants. First, E. coli-YS57 (pro-his-trp-) was mutagenized with N-methyl-N'-nitro-N-nitrosoguanidine and the binding to mouse spleen cells was used as a selective pressure. Second, phage-resistant mutants of E. coli-YS57 were obtained and tested for the ability to bind to lymphocytes. Out of 10 strains selected by the former procedure, 5 bound to a significant number of human lymphocytes. All four phage-resistant mutants bound to human lymphocytes. Out of the total of nine mutants that bound to lymphocytes, six bound consistently, i.e., they bound to similar percentages of peripheral blood lymphocytes from different normal donors. One phage-resistant mutant, E. coli USC-106, bound only to B cells. The subpopulations of lymphocytes identified by the mutants were essentially the same as those identified by different species or genera of bacteria. We concluded that E. coli mutants can be obtained that identify human lymphocyte subpopulations and that one of these mutants recognizes B cells; these mutants may be used to study the nature of the receptors for bacteria on lymphocytes, which appear to have a lectin-like nature.

The relationship between the percentage of circulating B cells, corticosteroid levels, and other immunologic parameters in thermally injured patients.

Thermal injury is known to induce alterations in the immune system, but the precise mechanisms have yet to be elucidated. We investigated the temporal relationship between serum and urine corticosteroid levels, the number of circulating B cells, serum immunoglobulin levels, and delayed hypersensitivity reactions in the postburn period. Fifteen adult patients (mean age, 44 years) admitted with thermal burns greater than 20% body surface area (BSA) (mean, 50%) were evaluated during four postburn periods. Using a bacterial adherence assay in blood smears, we observed an increased percentage of B lymphocytes (20.3%) in the early postburn period compared to normal controls obtained during the same time period (13.1%). The percentage of B cells gradually decreased during the subsequent 4 weeks and was not influenced by the eventual clinical outcome. The changes in B-cell percentage were paralleled by changes in the level of urine 17-hydroxysteroids. Serum IgG concentrations were low during the initial postburn period in survivors and nonsurvivors and returned to normal and above-normal levels in the late postburn period in both groups. The delayed hypersensitivity skin test reactions were also depressed in the immediate postburn period and returned to normal only in the surviving group at the end of the second postburn week. We speculate that the increased endogenous secretion of stress hormones results in an increase in circulating B cells secondary to their release from lymphoid organs and that the normalization of hormone levels as wound healing ensued was associated with the return of B cells to the lymphoid organs. This lymphocyte redistribution may result in polyclonal cellular interactions, with subsequent B-cell activation, and increased IgG production.

The use of bacteria as markers of leukemic lymphocytes and for the isolation of natural killer cells.

Human lymphocyte subpopulations as well as leukemic lymphocytes can be identified and enumerated in blood smears by using bacteria that bind spontaneously to lymphocytes or by using bacteria to which antibodies are chemically coupled. The mechanism of natural binding of bacteria to lymphocytes was shown to involve a lectin on the lymphocyte surface and a carbohydrate on the bacteria. Also, we found that natural killer (NK) cells can be separated by negative selection using monolayers of bacteria. A subpopulation of T cells, identified by their binding of B. globigii, was shown to be suppressors for NK cells.