Differences in molecular sensitization profiles between a Spanish and Latin American mite allergic patients.

BACKGROUND AND OBJECTIVE: To analyze the sensitization pattern to Dermatophagoides pteronyssinus and to associate the diagnostic findings and clinical severity in 218 allergic patients from two different continents. METHODS: Mite allergic patients were recruited by the Allergology departments from Latin America (n=88: Colombia, Costa Rica and Guatemala) and Spain (N=130). All patients had allergic rhinitis with or without asthma and positive skin prick test results to D. pteronyssinus. Specific IgE levels to D. pteronyssinus, D. farinae, Der p 1, Der p 2, and Der p 23 were quantified by ImmunoCAP system (ThermoFisher Scientific). Allergenic profile was also determined by western blot. Comparative Statistical analysis was performed by GraphPad software. RESULTS: Patients recognized most frequently Der p 2 (79%) followed by Der p 1 (73%), and Der p 23 (69%) allergens. The percentage of asthmatic patients increases with the number of sensitizations however none statistically significant differences were found. Interestingly, asthmatic patients presented the highest median levels of total IgE and specific IgE levels of D. pteronyssinus and molecular allergens, mainly Der p 2. Analysing the two different populations, Spanish patients were predominantly sensitized to Der p 2 (88.46%) and Der p 1 (83.84%), whereas Latin American population were more sensitized to Der p 23. CONCLUSION: Our data support the relevance of Der p 2 in mite allergy as the major allergen, with the high number of patients sensitized to it and its importance in the development of asthma. Sensitization to Der p 23 was more important in Latin America.

The effects of chemotherapy with bleomycin, etoposide, and cis-platinum on telomeres in rat male germ cells.

Co-administration of bleomycin, etoposide, and cis-platinum (BEP) has increased the 5-year survival rate of testis cancer patients to over 90%; however, this treatment induces chemotoxic effects on male germ cells. Treatment of male rats with BEP, using a similar schedule to that used in man, affects reproductive organ weights and sperm count, motility, and DNA integrity, as well as pup survival rates. Telomeres, specialized structures at the termini of chromosomes, play an important role in the maintenance of genetic stability. In previous studies, we demonstrated, using a spermatogonial cell line, that cis-platinum and bleomycin damage telomeres and that cis-platinum also inhibits telomerase activity. Our objective here was to test the hypothesis that in vivo exposure to the BEP regimen used to treat testis cancer targets telomeres in the male germ line. Adult male Brown Norway rats received chronic treatment with a BEP regimen. DNA double strand breaks were increased significantly in zygotene germ cells, as assessed by γ-H2AX immunofluorescence. Interestingly, treatment with this BEP regimen increased γ-H2AX foci in the telomere region of zygotene spermatocytes, but not in other germ cell types, such as pachytene cells, round spermatids, or elongating spermatids. Mean telomere lengths were reduced in zygotene, pachytene, round spermatid, elongating spermatid and cauda epididymal spermatozoa compared with the saline control group. Thus, telomere lengths did not recover during germ cell development. These studies demonstrate that BEP treatment is associated with an effect on telomeres.

Paternal exposure to testis cancer chemotherapeutics alters sperm fertilizing capacity and affects gene expression in the eight-cell stage rat embryo.

Treatment of testicular cancer includes the coadministration of bleomycin, etoposide and cis-platinum (BEP); however, along with its therapeutic benefit, BEP exposure results in extensive reproductive chemotoxic effects, including alterations to sperm chromatin integrity. As an intact paternal genome is essential for successful fertilization and embryogenesis, we assessed the effect of paternal exposure to BEP on sperm fertilization capacity and the resulting consequences on early embryonic gene expression. Adult male Brown Norway rats received a 9-week treatment with BEP or saline and then were sacrificed immediately or subject to a 9-week recovery period. HSP90AA1, HSP90B1 and PDIA3, involved in spermatozoa-egg interactions, were overexpressed in BEP-exposed spermatozoa after the 9-week treatment period; overexpression was also observed in spermatozoa from BEP-treated rats after 9 weeks of recovery. These proteins were localized to the plasma membrane of the sperm head; this localization may facilitate their role in spermatozoa-egg interactions as the highest staining intensities were observed in capacitated spermatozoa. The fertilization potential of spermatozoa was determined by in vitro fertilization with oocytes from unexposed naturally cycling female rats. Interestingly, the fertilization potential of spermatozoa following a 9-week recovery period from BEP treatment was significantly enhanced compared with controls. Moreover, stem cell transcription factors, involved in the regulation of a plethora of early embryonic events, were upregulated by more than twofold in eight-cell stage embryos sired by BEP recovery males compared with controls; this suggests that there are potential deleterious effects on embryo development well after termination of BEP exposure.

Use and outcomes of venous thromboembolism prophylaxis after spinal fusion surgery.

BACKGROUND: The number of spinal fusion operations in the USA is rapidly rising, but little is known about optimal venous thromboembolism prophylaxis after spinal surgery. OBJECTIVES: To examine the use of and outcomes associated with venous thromboembolism prophylaxis after spinal fusion surgery in a cohort of 244 US hospitals. PATIENTS/METHODS: We identified all patients with a principal procedure code for spinal fusion surgery in hospitals participating in the Premier Perspective database from 2003 to 2005, and searched for receipt of pharmacologic prophylaxis (subcutaneous unfractionated heparin, low molecular weight heparin, or fondaparinux) and/or mechanical prophylaxis (compression devices and elastic stockings) within the first 7 days after surgery. We also searched for discharge diagnosis codes for venous thromboembolism and postoperative hemorrhage during the index hospitalization and within 30 days after surgery. RESULTS: Among 80,183 spinal fusions performed during the time period, cervical fusions were the most common (49.0%), followed by lumbar fusions (47.8%). Thromboembolism prophylaxis was administered to 60.6% of patients within the first week postoperatively, with the most frequent form being mechanical prophylaxis alone (47.6%). Of the 244 hospitals, 26.2% provided prophylaxis to ≥ 90% of their patients undergoing spinal fusion; however, 33.2% provided prophylaxis to fewer than 50% of their patients. The rate of diagnosed venous thromboembolism within 30 days after surgery was 0.45%, and the rate of postoperative hemorrhage was 1.1%. CONCLUSIONS: Substantial variation exists in the use of thromboembolism prophylaxis after spinal fusion surgery in the USA. Nevertheless, overall rates of diagnosed thromboembolism after spinal fusion appear to be low.

Respiratory infection in asthma.

Ever since the first decades of the 20th century, some authors have given respiratory infection triggered by bacteria an etiologic role in bronchial asthma, focusing on infection and the asthmatic response. In 1995 our group already presented a study in this sense on nasal secretion cultures and the relationship between IgE and sensitization to allergens. There is a significant association between patients with sensitization to Dermatophagoides, high levels of total IgE, and positive culture to Staphylococcus aureus. Following studies by Norn, we performed a study with 40 children, aged 2-14 years, where we observed that children with sensitization to mites and a positive culture had higher levels of histamine release than did children with negative culture and controls, the differences being significant. We also found, like other authors, that the joint presence of Staphylococcus aureus and Derrmatophagoides pteronyssinus potentiates antigen-specific histamine release. In recent years, with the increasing prevalence of bronchial asthma being studied, the role that infection could play in this increase is being considered again among other factors. As participants of the ISAAC project and using the same methods as in this study, we performed a simultaneous questionnaire with questions related with triggering and contributing factors, etc., including respiratory infection. We found an association between having had more than three episodes of "bronchitis" with fever and lasting for longer than seven days in the last year and having ever had asthma (OR 29.09). This association is still greater with having had wheezing in the last 12 months (OR 43.26), a finding that it is also associated with requiring attention in an emergency room (OR 30.65). From these results, we concluded that respiratory infection is an aggravating factor of asthma, something we already knew. In order to have our own experience, we studied serum interleukin 4 (IL-4) and interferon gamma (IFNgamma) in a sample of 41 children aged 3 to 17 years. The most frequent values of IL-4 ranged between 0.25 and 0.40 ng, and very low dispersion was found in the sample, which did not allow correlation with other parameters. Regarding IFNgamma, we found values between < 5 pg/ml and 605 pg/ml. When we studied children under treatment with antigen-specific immunotherapy, we observed mean values of IFNgamma of 115.86 pg/ml, whereas the ones who did not follow this treatment or had followed it for less than one year had a mean of 66.06 pg/ml, these differences being significant (p = 0.035), and proving a Th1 response to immunotherapy. This significance is not found if children who have been under immunotherapy for less than one year are included. When we studied children with bacterial immunotherapy, we found that the mean IFNgamma value in children under immunotherapy for longer than one year was 56.4 pg/ml, whereas in children with no immunotherapy it was 101.75 pg/ml (p = 0.034). We conclude that bacterial immunotherapy modifies the Thl response, inhibiting it in those children with greater susceptibility to infections.

Allergy to pine nut.

BACKGROUND: food allergy is highly prevalent in our environment, especially among atopic patients. Pinus pinea is common in our region and its fruit, the pine nut, is allergologically important. Several cases have been reported in the literature that demonstrate the existence of common antigenic bands between pine nut and almond. In this study we try to assess this finding and the possible existence of common allergens by in vitro techniques. METHODS AND RESULTS: we present a 10-year-old boy, previously diagnosed of seasonal rhinoconjunctivitis with sensitisation to grass and olive pollen, who had an anaphylactic reaction after eating pine nut. We performed in vivo (prick test, prick-by-prick) and in vitro tests (total and specific IgE determinations [CAP-FEIA]), histamine release test, and immunoblotting (SDS-PAGE). We also reviewed the literature through the MEDLINE database in PubMed. CONCLUSIONS: because pine nut is commonly consumed in our environment, the prevalence of allergic reactions is probably considerable and these reactions take place at an early age. We demonstrate the existence of common antigenic proteins between pine nut and peanuts.

Flow cytometric basophil activation test: a review.

Flow cytometry is a technique enabling the analysis of physical and biological characteristics of cells or other biological particles when labeled with antibodies coupled to fluorochromes or other dyes. The basophil activation test (BAT), also called flow-cytometric allergen stimulation test (FAST) [commercially available under the name of Flow CAST (Bühlmann Laboratories) or BASOTEST (Beckton-Dickinson)] is based on the in vitro allergen-induced specific activation of basophils. This assay rests on the demonstration of some membrane protein markers that appear after exposure to the allergen. This paper reviews some of the literature about the use of this technique in the investigation of immediate-type allergies to inhalant allergens, drugs, and foods, as well as our own experience with this diagnostic technique. Flow cytometry is a reliable method for the quantification of basophil activation after allergenic stimulus in vitro and in vivo. It also enables us to detect allergic and pseudoallergic reactions because of other mechanisms than allergen-specific IgE antibodies. Further clinical evaluation of this technique will allow validation and better establishment of its diagnostic value in allergy.

Excessive antibiotic use for acute respiratory infections in the United States.

Estimating the amount and cost of excess antibiotic use in ambulatory practice and identifying the conditions that account for most excess use are necessary to guide intervention and policy decisions. Data from the 1998 National Ambulatory Medical Care Survey, a sample survey of United States ambulatory physician practices, was used to estimate primary care office visits and antibiotic prescription rates for acute respiratory infections. Weight-averaged antibiotic costs were calculated with use of 1996 prescription marketing data and adjusted for inflation. In 1998, an estimated 76 million primary care office visits for acute respiratory infections resulted in 41 million antibiotic prescriptions. Antibiotic prescriptions in excess of the number expected to treat bacterial infections amounted to 55% (22.6 million) of all antibiotics prescribed for acute respiratory infections, at a cost of approximately $726 million. Upper respiratory tract infections (not otherwise specified), pharyngitis, and bronchitis were the conditions associated with the greatest amount of excess use. This study documents that the amount and cost of excessive antibiotic use for acute respiratory infections by primary care physicians are substantial and establishes potential target rates for antibiotic treatment of selected conditions.

Impact of reducing antibiotic prescribing for acute bronchitis on patient satisfaction.

CONTEXT: Using a patient and clinician educational intervention, we successfully reduced antibiotic use for uncomplicated acute bronchitis. The impact of this intervention on patient satisfaction is not known. OBJECTIVE: To evaluate whether a strategy for reducing antibiotic use in acute bronchitis affects satisfaction among adult patients. DESIGN: Telephone survey administered 1 to 4 weeks after an office visit for acute bronchitis. SETTING: Two outpatient clinics belonging to a group-model HMO in the Denver, Colorado, metropolitan area. The intervention clinic had received a patient and office-based educational intervention that successfully reduced antibiotic prescribing for acute bronchitis during the previous winter. The control clinic received only the office-based materials, an intervention that did not reduce antibiotic prescribing. OUTCOME: Overall satisfaction with the episode of care. RESULTS: Antibiotics were prescribed to 64% and 85% of survey respondents at the intervention (n = 102) and control clinics (n = 164), respectively (P < 0.001). Patient satisfaction with the visit did not differ between intervention and control clinics (69% of intervention and 63% of control clinic patients reported very good or excellent satisfaction, P > 0.2). After adjustment for patient age, sex, duration of illness before the visit, reason for visit, and clinician specialty, there was no difference between intervention and control clinics in the proportion of patients reporting very good or excellent satisfaction (adjusted relative risk for high satisfaction at the intervention clinic, 1.1 [95% CI, 0.81 to 1.3]). CONCLUSION: A patient- and clinician-oriented educational intervention that reduces antibiotic treatment of adults with uncomplicated acute bronchitis does not appear to reduce satisfaction with care.

Measuring antibiotic prescribing practices among ambulatory physicians: accuracy of administrative claims data.

To assess the accuracy of administrative claims data for measuring antibiotic prescribing behavior, we conducted a stratified randomized medical record review of office visits by children with pharyngitis, and adults with acute bronchitis, to primary care physicians in Colorado in 1998. The diagnoses of pharyngitis (n = 422) and acute bronchitis (n = 497) based on administrative data were verified in 83% and 79%, respectively, of medical records. The sensitivity, specificity, and positive predictive value of administrative data in identifying antibiotic treatment for pharyngitis was 68%, 91%, and 90%, respectively, and for bronchitis was 79%, 84% and 98%, respectively. The sensitivity, specificity, and negative predictive value of administrative data in identifying group A streptococcal test ordering for pharyngitis was 71%, 86%, and 30%, respectively. Absence of testing in administrative data (when present in the medical record) was more frequent among visits to physicians associated with a capitated health plan. We conclude that administrative claims data are accurate sources for measuring and profiling antibiotic prescribing practices in ambulatory practice, although they underestimate actual antibiotic treatment decisions by individual physicians. Measuring and profiling antibiotic prescribing behavior in relation to group A streptococcal test utilization may overestimate inappropriate antibiotic treatment by physicians enrolled in capitated contracts.

Antibiotic prescribing for patients with colds, upper respiratory tract infections, and bronchitis: A national study of hospital-based emergency departments.

STUDY OBJECTIVE: Antibiotics are often used to treat viral upper respiratory tract infections, even though they are usually ineffective. However, frequent inappropriate antibiotic use contributes to the emergence of drug-resistant bacterial pathogens. This study used a national database to evaluate antibiotic use in treating upper respiratory tract infections in emergency departments. METHODS: Data were obtained from the 1996 National Hospital Ambulatory Medical Care Survey. Antibiotic prescribing rates were examined for colds, upper respiratory tract infections, and acute bronchitis. Patients with comorbid conditions or secondary diagnoses, such as chronic obstructive pulmonary disease, pneumonia, sinusitis, and HIV, were excluded. Bivariate and multivariate analyses were used to assess predictors of antibiotic use. RESULTS: Overall, there were an estimated 2.7 million ED visits for colds, upper respiratory tract infections, and bronchitis by children and adults in 1996. Antibiotics were prescribed for 24.2% (95% CI 18.9, 29.5) of patients with common colds and upper respiratory tract infections and for 42.2% (95% CI 35.2, 49.2) of patients with bronchitis. There were no significant associations between antibiotic use and patient race, sex, Hispanic ethnicity, geographic location, or source of payment. Antibiotics were prescribed less often by interns or residents than by staff or other physicians (odds ratio 0.43; 95% CI 0.19, 0.98), and patients younger than 18 years were less likely to receive antibiotics than adults (odds ratio 0.32; 95% CI 0.20, 0.52). Smokers were 4.3 (95% CI 2.2, 8.3) times more likely to receive antibiotics than nonsmokers. CONCLUSION: Antibiotics are commonly prescribed for ED patients with upper respiratory tract infections even though they are usually ineffective in otherwise healthy adults. Efforts should be made to reduce inappropriate antibiotic use for the sake of containing costs, preventing side effects, and limiting the spread of antibiotic resistance.

Regulation of smooth muscle alpha-actin promoter by vasopressin and platelet-derived growth factor in rat aortic vascular smooth muscle cells.

Vasoconstrictors such as arginine vasopressin (AVP) and angiotensin II (Ang II) have been shown to increase protein and mRNA levels of smooth muscle alpha-actin (SM-alpha-actin) in vascular smooth muscle cells. In the same cells, platelet-derived growth factor (PDGF) decreased SM-alpha-actin protein and mRNA. The rat SM-alpha-actin promoter that has recently been isolated contains two E-boxes and three CC(A/T)6GG (CArG) elements. To examine regulation of the SM-alpha-actin promoter, a 765-bp region of the rat SM-alpha-actin gene was ligated into chloramphenicol acetyltransferase (CAT)-containing vectors and transfected into rat aortic vascular smooth muscle cells. Stimulation of cells with either AVP or Ang II increased CAT activity 5- to 10-fold. PDGF was able to completely block the AVP-induced increase in CAT activity. To identify regions of the promoter responsible for both the AVP stimulation and PDGF inhibition of promoter activity, a series of truncation mutants were prepared and transfected into vascular smooth muscle cells. Truncation of both E-boxes and the most distal CArG element did not qualitatively alter either AVP-induced stimulation of CAT activity or PDGF inhibition. However, removal of the middle CArG element resulted in a loss of AVP stimulation. These studies indicate that the AVP-induced elevation and PDGF-induced inhibition of SM-alpha-actin levels in vascular smooth muscle cells are mediated at least in part through regulation of the SM-alpha-actin promoter. The critical region of the promoter mediating this effect involves at a minimum one of the CArG elements.

Correlation of plasma angiotensin II concentration and plasma renin activity during acute hypoxia in dogs.

The effects of isocapnic hypoxia on plasma renin activity (PRA) and angiotensin II (AII) concentration were studied in anaesthetized, artificially ventilated dogs. Regression analysis of plasma AII concentration vs PRA, both measured by radioimmunoassay (RIA), was used as an index of converting enzyme activity in vivo. PaO2 decreased from 82 to 30 mmHg but regression analysis did not reveal any inhibition of AII production within the limits of detection of this method (less than 20% inhibition). We conclude that systemic converting enzyme activity, assessed by in vivo measurement and correlation of PRA and AII, is not inhibited by severe hypoxia.

Role of the renin-angiotensin system in the control of vasopressin and ACTH secretion during the development of renal hypertension in dogs.

Experiments were performed to determine if the activation of the renin-angiotensin system that occurs during the development of two-kidney, one clip Goldblatt hypertension in dogs is accompanied by increases in vasopressin and adrenocorticotrophic hormone (ACTH) secretion. Following renal artery constriction, there were marked increases in arterial blood pressure, plasma renin activity (PRA), and plasma angiotensin II (AII) concentration. These changes were accompanied by an increase in plasma vasopressin concentration during the second week following constriction, and there were significant correlations between plasma vasopressin concentration and PRA (r = 0.57, p less than 0.001), and between plasma vasopressin concentration and plasma AII concentration (r = 0.59, p less than 0.001). In contrast, plasma corticosteroid concentration, used as an index of changes in ACTH secretion, did not change significantly. Acute blockade of the renin-angiotensin system with captopril or saralasin produced the expected changes in blood pressure, PRA, and plasma AII concentration but did not decrease plasma vasopressin or corticosteroid concentrations. These results indicate that during the development of renal hypertension in dogs, there may be an interaction between the renin-angiotensin system and vasopressin, but not between the renin-angiotensin system and the pituitary-adrenal axis. They also show that the antihypertensive action of captopril in this experimental model is not mediated via suppression of vasopressin, ACTH, or corticosteroid secretion.

Role of vasopressin in blood pressure regulation during adrenal insufficiency.

The effect of adrenal insufficiency on the plasma concentrations of two vasoactive hormones, vasopressin and angiotensin II, was studied in conscious dogs. In addition the role of vasopressin in the maintenance of blood pressure during adrenal insufficiency was studied using [1-(beta-mercapto-beta, beta-cyclopentamethylenepropionic acid),2-(O-methyl)tyrosine]arginine vasopressin, a specific antagonist of the vasoconstrictor action of vasopressin. Dogs were bilaterally adrenalectomized and maintained on daily cortisol and deoxycorticosterone acetate injections. Withdrawal of steroids for 4 days resulted in a 4-fold increase in plasma vasopressin concentration (P less than 0.05) and a 3-fold increase in plasma angiotensin II concentration (P less than 0.001); mean arterial pressure did not change significantly. Administration of the vasopressin antagonist in adrenalectomized dogs maintained on steroids had no effect on blood pressure. In marked contrast, vasopressin blockade in dogs with adrenal insufficiency decreased mean arterial pressure by 22 +/- 5 mm Hg (P less than 0.001). These results demonstrate the plasma angiotensin II and vasopressin concentrations increase during adrenal insufficiency in conscious dogs, and that vasopressin plays an important role in blood pressure regulation in this hypovolemic state.

Distal splenorenal shunt vs. portal-systemic shunt: current status of a controlled trial.

A prospective controlled comparison of portal-systemic (PSS) and distal splenorenal shunts (DSRS) in cirrhotic patients who had survived hemorrhage from esophagogastric varices was undertaken 5 yr ago at five hospitals by the Boston-New Haven Collaborative Liver Group. The clinical and endoscopic criteria for massive hemorrhage were satisfied in 155 patients. Thirty-four patients were excluded, primarily because of uncontrolled hemorrhage. Thirty-four were rejected because the were poor operative risks and 21 because they did not satisfy criteria. Thirteen patients refused to participate; the remaining 53 were randomized; 29 to receive PSS and 24, DSRS. The two groups were similar in clinical, laboratory, and manometric characteristics. The DSRS group was older and tended to have had more previous hemorrhages. Followup ranged from 1 to 56 months (mean 21). After PSS, which was performed by 10 different surgeons, 6 patients died during the hospital admission (21%) compared to 2 after DSRS (12%). There were 6 late deaths in the PSS group and 4 in the DSRS group. Portal-systemic encephalopathy occurred in 5 of the 23 survivors of PSS (23%), and in 6 of the 19 who survived DSRS (32%. Two patients in the PSS group bled (9%), 1 after thrombosis and 1 after stenosis of the shunt. Three patients in the DSRS group bled (16%) and all had thrombosis of the shunt. PSS was associated with an unexplained but inordinately high operative mortality. Although the DSRS was accomplished with an acceptably low operative mortality, it was associated with frequent portal-systemic encephalopathy, shunt occlusion, and recurrent hemorrhage. Similar incidences of portal-systemic encephalopathy, shunt occlusion, and recurrent hemorrhage were observed in the PSS group. More patients and longer followup are necessary to determine which of these portal decompressive procedures is superior.