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PubMed2001

Prevalence, characteristics and diabetes risk associated with transient maternally acquired islet antibodies and persistent islet antibodies in offspring of parents with type 1 diabetes.

Accurate assessment of type 1 diabetes risk in young children requires discrimination between antibodies that are produced by the child and antibodies acquired through the placenta from an islet antibody-positive mother. We studied 682 offspring from mothers with type 1 diabetes and 329 offspring from fathers with type 1 diabetes and nondiabetic mothers for insulin (auto)antibodies, glutamic acid decarboxylase antibodies, and tyrosine phosphatase IA-2 antibodies before age 1 yr and again at age 2 yr to ascertain transience or persistence. Antibodies were detected at age 9 months in 5 (1.5%) offspring from fathers with type 1 diabetes; all were insulin (auto)antibodies only, all persisted and developed multiple antibodies, and 1 developed type 1 diabetes. In contrast, 31 (4.5%) offspring from mothers with type 1 diabetes had antibodies at 9 months; 12 (1.8%) persisted at age 2 yr, and 19 (2.8%) did not persist, suggestive of transient residual maternal antibodies. Multiple antibodies at 9 months were usually persistent (3 of 4 offspring), as were single insulin (auto)antibodies in offspring from mothers with type 1 diabetes (8 of 13 offspring), whereas persistent glutamic acid decarboxylase antibodies (1 of 12) and tyrosine phosphatase IA-2 antibodies (0 of 2) were rare. Offspring with persistent antibodies at age 9 months had a high type 1 diabetes risk (100% by age 5 yr for those with multiple antibodies and 27% for single antibodies at 9 months), whereas offspring with transient antibodies had 0% type 1 diabetes risk (P < 0.01). Transience was associated with very high antibody levels at birth. For insulin (auto)antibodies, the measurement of subclass was also informative. Residual maternal antibody was indicated by similar insulin (auto)antibodies subclasses at 9 months and at birth, whereas different subclasses were indicative of nonmaternal antibody. Moreover, the presence of IgG1-insulin (auto)antibodies was associated with antibody persistence and type 1 diabetes risk. These strategies are helpful in discriminating high and low risk antibodies before age 1 yr and should be important for prognosis and reducing unnecessary parent anxiety.

Autoantibodies↗
PubMed1999

Measuring persistent cough in children in epidemiological studies: development of a questionnaire and assessment of prevalence in two countries.

STUDY OBJECTIVE: Cough is a common symptom in children that is frequently encountered in general practice. However, most of the information on the prevalence of persistent cough has come from studies that use different, often ambiguous, definitions for persistent cough. It is therefore important that a validated questionnaire to accurately measure persistent cough is developed and is appropriate for use in different age groups of children and in different cultures. Such a questionnaire is essential for accurately measuring the prevalence of persistent cough and the factors associated with its occurrence. DESIGN: A parent-administered respiratory questionnaire was developed and administered twice during a 3-week interval pilot study to test repeatability. The questionnaire was then administered to a randomly selected cross-section of Australian children aged 5 to 7 years old and 8 to 11 years old (N = 511 and N = 654, respectively), and to 566 Nigerian children aged 8 to 11 years old. RESULTS: The new questionnaire was reliable, with most of the questions having a kappa value of above 0.6. The prevalence of persistent cough was similar in younger and older Australian children, but significantly less in Nigerian children (p < 0.001). Also, persistent cough was more prevalent in children of high rather than low socioeconomic status among older Australian children (p = 0.04). CONCLUSIONS: The newly developed questionnaire will be an important tool in epidemiological studies for measuring the prevalence, morbidity, and risk factors of persistent cough in childhood. Although our findings showed that persistent cough does not occur more frequently in younger than in older Australian children, it is more frequent in Australian than in Nigerian children.

Australia↗
PubMed2005

Bacterial persistence: a model of survival in changing environments.

The persistence phenotype is an epigenetic trait exhibited by a subpopulation of bacteria, characterized by slow growth coupled with an ability to survive antibiotic treatment. The phenotype is acquired via a spontaneous, reversible switch between normal and persister cells. These observations suggest that clonal bacterial populations may use persister cells, whose slow division rate under growth conditions leads to lower population fitness, as an "insurance policy" against antibiotic encounters. We present a model of Escherichia coli persistence, and using experimentally derived parameters for both wild type and a mutant strain (hipQ) with markedly different switching rates, we show how fitness loss due to slow persister growth pays off as a risk-reducing strategy. We demonstrate that wild-type persistence is suited for environments in which antibiotic stress is a rare event. The optimal rate of switching between normal and persister cells is found to depend strongly on the frequency of environmental changes and only weakly on the selective pressures of any given environment. In contrast to typical examples of adaptations to features of a single environment, persistence appears to constitute an adaptation that is tuned to the distribution of environmental change.

Algorithms↗
PubMed2004

Tympanic membrane abnormalities and hearing levels at the ages of 5 and 6 years in relation to persistent otitis media and tympanostomy tube insertion in the first 3 years of life: a prospective study incorporating a randomized clinical trial.

OBJECTIVE: One current practice guideline recommends myringotomy with tympanostomy tube insertion (M&T) for young children in whom middle-ear effusion (MEE) has persisted for 3 months, and another recommends the procedure after MEE has persisted for 4 to 6 months provided that a bilateral hearing loss of > or=20 dB is present. Sequelae of M&T are not uncommon, but the extent to which these sequelae are attributable to M&T itself or to the middle-ear disease that prompted the procedure or to both has not been clear. Our objective in the present study was to examine the prevalence of various tympanic membrane (TM) abnormalities in otherwise healthy children at the age of 5 years and hearing levels at the age of 6 years in relation to persistent MEE and M&T in the children's first 3 years of life. METHODS: In a prospective study of child development in relation to early-life otitis media, we randomly assigned 429 children who met specified criteria regarding the persistence of MEE in their first 3 years of life to undergo M&T either promptly (the "early-treatment" group) or after a defined extended period if MEE remained present (the "late-treatment" group). We also followed a representative sample of 241 children who ranged from having no MEE to having MEE whose cumulative duration fell just short of meeting randomization criteria for the clinical trial (the "nontrial" group). Most of the children in each group underwent both otomicroscopic examination at the age of 5 years and audiometric testing at the age of 6 years, at times when they were free of MEE. Among these children, M&T had been performed in 82.3% of those in the early-treatment group, 38.1% of those in the late-treatment group, and 3.0% of those in the nontrial group. RESULTS: At the age of 5 years, we found 1 or more types of TM abnormality in 1 or both ears in 70.7%, 42.5%, and 9.5% of the children in the early-treatment, late-treatment, and nontrial groups, respectively. Within the 3 groups, however, among children who received tubes, the proportions who had an abnormality of some type were similar, namely, 82.6%, 80.4%, and 83.3%, respectively. The corresponding proportions among children who had not received tubes were 15.4%, 19.3%, and 7.2%, respectively. Segmental atrophy and tympanosclerosis were the most common abnormalities found. At the age of 6 years, mean pure-tone average audiometric thresholds in the early-treatment, late-treatment, and nontrial groups, respectively, were 6.18 dB, 5.49 dB, and 4.63 dB in left ears and 6.17 dB, 6.02 dB, and 4.32 dB in right ears. The thresholds in the early- and late-treatment groups did not differ significantly, but the thresholds in the early- and late-treatment groups were each significantly higher than in the nontrial group. Within the early- and late-treatment groups, we found no significant relation between hearing levels and the presence or type of TM abnormalities. CONCLUSION: In otherwise healthy children who have persistent MEE during their first 3 years of life, ready resort to M&T results in far more TM abnormalities at age 5 than does selective management in which most children do not receive the procedure. With these differing approaches, however, hearing levels at age 6 do not differ. Regardless of whether children with persistent early-life MEE receive M&T, they have more TM abnormalities at age 5 and negligibly poorer hearing at age 6 than do children who had less or no otitis media. Longer term otologic and audiologic outcomes of persistent early-life MEE and of M&T remain to be determined. In view of 1) the present findings and the remaining uncertainties concerning sequelae, 2) the fact that M&T involves certain immediate risks--albeit minimal--and substantial cost, and 3) previously reported findings in the study's randomized clinical trial that show no developmental advantage at ages 3 and 4 years accruing from children's having received prompt M&T, a prolonged period of watchful waiting seems desirable in otherwise healthy children who are younger than 3 years and have persistent, asymptomatic MEE that is not complicated by sensorineural or severe conductive hearing loss, balance dysfunction, or severe TM retraction.

Age Factors↗
PubMed2005

Decreased persistence to cholinesterase inhibitor therapy with concomitant use of drugs that can impair cognition.

STUDY OBJECTIVES: To assess persistence with cholinesterase inhibitor therapy 6 months after the start of treatment, and to determine whether the likelihood of persistence is associated with the coprescription of drugs that can impair cognition. DESIGN: Retrospective cohort study. SETTING: Community (home residence) or long-term care facility. PATIENTS: A total of 1183 patients enrolled in the Rhode Island Medicaid program, aged 45 years or older, who were dispensed a cholinesterase inhibitor from January 1, 2000-June 30, 2002. MEASUREMENTS AND MAIN RESULTS: Patients were considered persistent with treatment if they filled at least five prescriptions for a 1-month supply of the same cholinesterase inhibitor, without an extended gap in days between refills. We compared rates of persistence among patients receiving and those not receiving drugs that can impair cognition. Covariates assessed were patient age, sex, race, and care setting. Approximately one in four patients discontinued cholinesterase inhibitor therapy within 6 months. Patients aged 85 years or older were more persistent than younger patients (77% vs 71%, p<0.05). Caucasian patients were more likely to be persistent than non-Caucasian patients (74% vs 52%, p<0.001). Patients living in the community were less likely to persist than those residing in long-term care facilities (58% vs 76%, p<0.001). After adjusting for race and care setting, patients who were prescribed drugs that can impair cognition were more likely not to have persisted with cholinesterase inhibitor therapy at 6 months than those who did not receive such drugs (odds ratio 1.56, 95% confidence interval 1.13-2.16). CONCLUSION: A substantial percentage of patients who began receiving cholinesterase inhibitor therapy had discontinued the therapy within 6 months. Many patients also received prescriptions for agents that can impair cognition. Our findings indicated a modest but statistically significant increase in likelihood of treatment discontinuation among patients who also received prescriptions for drugs that can impair cognition. Iatrogenic causes of dementia are important to recognize and address so that therapies for enhancing cognition can be fully effective.

Age Factors↗
PubMed2005

Drug persistency of two cholinesterase inhibitors: rivastigmine versus donepezil in elderly patients with Alzheimer's disease.

OBJECTIVES: To compare persistency rates and persistency days in patients with Alzheimer's disease (AD) who initiated therapy with either rivastigmine or donepezil, and to identify factors influencing persistency in a real-world setting. DESIGN AND METHODS: This study used data collected by MarketScan from 1 January 1999 to 31 December 2002. Patients were included if they were newly diagnosed with AD and filled at least one prescription for rivastigmine or donepezil between 1 July 2000 and 30 June 2001, were > or =65 years of age on the index prescription date, and had continuous health and prescription insurance during the entire study period. Patients were excluded if they filled a prescription for any cholinesterase inhibitor during the 18 months prior to initiation of the study drugs. Patients who refilled their initial cholinesterase inhibitor prescription within a permissible gap of 60 days after depleting the drug supply from the prior prescription were considered to be persistent. Sensitivity analysis was performed to test the robustness of the persistency definition. The Kaplan-Meier method was used to determine persistency rates across time and Cox proportional hazards models were used to estimate relative risks of discontinuation or switch with adjustment for other covariates, and to identify factors significantly influencing persistency of the study drugs. RESULTS: Of the newly treated AD patients, the proportion of rivastigmine and donepezil patients who continued their medication was the same (47%; p = 0.5). On average, rivastigmine users continuously used their medication for 234 days (median 312 days) while those taking donepezil used their medication for 235 days (median 315 days) [p = 0.91]. Patients were more likely to discontinue or switch their initial cholinesterase inhibitor if they used a central nervous system (CNS) medication before initiation of therapy (relative risk [RR] = 1.23; 95% CI 1.01, 1.51 without adjustment for study variables; RR = 1.30; 95% CI 1.05, 1.60 with adjustment for study variables). On the other hand, patients were less likely to discontinue their cholinesterase inhibitor if they visited their physician office frequently (RR = 0.24; 95% CI 0.18, 0.32 without adjustment; RR = 0.23; 95% CI 0.17, 0.30 with adjustment) or if they were hospitalised after initiation of their cholinesterase inhibitor therapy (RR = 0.60; 95% CI 0.39, 0.91 without adjustment; RR = 0.65; 95% CI 0.42, 0.99 with adjustment). CONCLUSION: Patients who were newly diagnosed with AD and initiated therapy with either rivastigmine or donepezil had similar levels of persistency with their initial AD therapy in a real-world setting.

Aged↗
PubMed2001

Study of cattle persistently infected with bovine viral diarrhea virus that lack detectable virus in serum.

OBJECTIVE: To determine whether cattle persistently infected with bovine viral diarrhea virus (BVDV) that lack virus detectable in serum by use of the immunoperoxidase microtiter assay (IPMA) can transmit the virus to susceptible herdmates and determine prevalence of these cattle. DESIGN: Clinical trial and serologic survey. SAMPLE POPULATION: 2 cattle and 1,952 blood samples. PROCEDURE: A persistently infected cow in which virus could not be detected in serum was housed with a BVDV-seronegative steer. Blood and nasal swab specimens were tested via virus isolation and serum virus neutralization. Parallel WBC preparations and sera from blood samples of 1,952 adult cows were screened for BVDV by use of IPMA. RESULTS: The steer seroconverted to BVDV within 4 weeks of contact with the cow. Virus was detected in sera and WBC of 5 adult cows that were verified as persistently infected by retest 3 weeks later. Cattle persistently infected with BVDV in which virus could not be detected in both serum and WBC by use of IPMA were not found. CONCLUSION AND CLINICAL RELEVANCE: Cattle persistently infected with BVDV in which virus cannot be detected in serum by use of IPMA may serve as virus reservoirs for infecting susceptible cattle. Persistent infection was detected at a prevalence of 0.26%. Screening adult cattle by use of IPMA on serum samples appears to be a reliable means of detecting persistent infection with BVDV. Prevalence of cattle persistently infected with BVDV that have negative results of IPMA on serum is extremely low.

Animals↗
PubMed1993

Measuring persistence and personality characteristics of adolescents.

The concept of persistence (to hold firmly and steadfastly to some purpose or task) has been reportedly related to personality development, motivation, and locus of control. However, there is a dearth of research on persistence primarily because a widely accepted and validated measure of persistence is lacking. A 1987 measure, the Persistence Scale for Children by Lufi and Cohen, has been the subject of validation and reliability studies. The present paper is a description of its use with 50 adolescents and the correlations between persistence and the adolescents' personality characteristics, based on Cattell's High School Personality Questionnaire. Correlations between persistence and HSPQ personality characteristics were significant. Replication with a larger sample and continued use in the study of persistence is discussed as well as persistence in relation to adolescent development.

Adolescent↗
PubMed2004

Persistent and dormant tubercle bacilli and latent tuberculosis.

Tubercle bacillus has remarkable ability to persist in the human host and has caused latent infection in one third of the world population. The current tuberculosis (TB) chemotherapy while effective in killing growing bacilli is largely ineffective in killing persistent or dormant bacilli, leading to prolonged therapy. There is considerable recent interest to study mechanisms of persistence and dormancy in mycobacteria. Meanwhile, there is also confusion about the use of terminology of dormant and persistent bacilli. Different models of mycobacterial persistence have been established. Various mycobacterial factors have recently been identified that may be involved in persistence or dormancy and resuscitation of dormant organisms. The phenotypic resistance to antituberculosis drugs in persistent and dormant bacilli presents a major challenge for effective control of the disease. The host immune system is critical in controlling latent TB infection from reactivation. A recent interesting observation is the reactivation of latent TB infection by anti-TNF-alpha antibody used as a treatment for rheumatoid arthritis and Crohn's disease. The role of psychoneuroendocrinological factors in TB, which is often ignored in the era of modern chemotherapy but could be important for controlling latent infection, is also briefly reviewed. There is recent interest to develop new TB drugs that target persistent and dormant bacilli and also immunotherapeutic agents that enhance chemotherapy and better control latent infection. The complex interaction between the bacteria, drugs, host and the environment underscores the need for a combined approach that incorporates chemotherapy, immunotherapeutic agents, improved socioeconomic, nutritional and even conducive psychological factors for more effective control of TB and latent TB.

Antitubercular Agents↗
PubMed2006

Genetic evaluation and best prediction of lactation persistency.

Cows with high persistency tend to produce less milk than expected at the beginning of lactation and more than expected at the end. Best prediction of persistency was calculated as a function of a trait-specific standard lactation curve and a linear regression of test-day deviations on days in milk. Regression coefficients were deviations from a balance point to make yield and persistency phenotypically uncorrelated. The objectives of this study were to calculate (co)variance components and breeding values for best predictions of persistency of milk (PM), fat (PF), protein (PP), and SCS (PSCS) in Holstein cows. Data included 8,682,138 lactations from 4,375,938 cows calving since 1997, and 39,354 sires were evaluated. Sire estimated breeding values (EBV) for PM, PF, and PP were similar and ranged from -0.70 to 0.75 for PM; EBV for PSCS ranged from -0.37 to 0.28. Regressions of sire EBV on birth year were near zero (<0.003) but positive for PM, PF, and PP, and negative for PSCS. Genetic correlations of PM, PF, and PP with PSCS were moderate and favorable, indicating that increasing SCS decreases yield traits, as expected. Genetic correlations among yield and persistency were low to moderate and ranged from -0.09 (PSCS) to 0.18 (PF). This definition of persistency may be more useful than those used in test-day models, which are often correlated with yield. Routine genetic evaluations for persistency are feasible and may allow for improved predictions of yield traits. As calving intervals increase, persistency may have greater value.

Animals↗
PubMed2006

Genetic analysis of persistency in the israeli holstein population by the multitrait animal model.

Persistency was defined as the predicted milk production 180 d after peak divided by peak production (in %). Heritability of persistency in a multitrait analysis including parities 1 through 5 increased from 0.16 to 0.27 from first through third parity, and then declined through fifth parity. Genetic correlations for persistency between consecutive parities were all > 0.8. First-parity genetic correlations of the traits included in the Israeli selection index with persistency were all < 0.1, except for fertility and herdlife, which were 0.20 and 0.25; whereas second-parity genetic correlations of persistency with the 3 milk production traits were all > 0.34, and the genetic correlation with fertility was only 0.10. The genetic correlation between second-parity persistency and herdlife was 0.58. Persistency in the Israeli Holstein population was analyzed by the multitrait animal model. The genetic trend since 1985 for the multiparity index was 0.22% persistency/yr, even though there was no direct selection on persistency.

Animals↗
PubMed2000

Persistent Listeria monocytogenes strains show enhanced adherence to food contact surface after short contact times.

Adherence of 3 persistent and 14 nonpersistent Listeria monocytogenes strains to stainless steel surfaces after short and long contact times was investigated. L. monocytogenes strains were obtained from poultry plants and an ice cream plant throughout several years. Adherence tests were performed in tryptic soy broth at 25 degrees C for 1, 2, and 72 h. Test surfaces were rinsed after the contact time, and attached cells were stained with acridine orange and enumerated with an epifluorescence microscope. The persistent poultry plant strains showed adherence 2- to 11-fold higher than the nonpersistent strains following 1- and 2-h contact times. The adherence of the persistent ice cream plant strain after 1- and 2-h contact times was higher than most of the nonpersistent strains. Seven of 12 nonpersistent ice cream strains showed an adherence of less than half that of the persistent strain. After 72 h, the differences in adherence were not as marked, since half the nonpersistent strains had reached adherence levels comparable with the persistent strains. In fact, three nonpersistent strains showed even higher adherence than the persistent strains. Thus, results of this study reveal that persistent L. monocytogenes strains show enhanced adherence at short contact times, promoting their survival in food processing facilities and possibly having an effect on initiation of persistent plant contamination.

Animals↗
PubMed2002

Transfer of persistent Listeria monocytogenes contamination between food-processing plants associated with a dicing machine.

The possibility of the transfer of persistent Listeria monocytogenes contamination from one plant to another with a dicing machine was evaluated, and possible reasons for persistent contamination were analyzed. A dicing machine that diced cooked meat products was transferred from plant A to plant B and then to plant C. After the transfer of the dicing machine, L. monocytogenes PFGE type I, originally found in plant A, was soon also found in plants B and C. This L. monocytogenes PFGE type I caused persistent contamination of the dicing lines in plants B and C. The persistent L. monocytogenes strain and three nonpersistent L. monocytogenes strains found in the dicing line of plant C were tested for adherence to stainless steel surfaces and minimal inhibitory concentrations of a quaternary ammonium compound and sodium hypochlorite, disinfectants widely used in the dicing lines. The persistent strain showed significantly higher adherence to stainless steel surfaces than did the nonpersistent strains. The minimal inhibitory concentrations of sodium hypochlorite were similar for all strains, and the minimal inhibitory concentrations of the quaternary ammonium compound for three of the L. monocytogenes PFGE types, including the persistent PFGE type, were high. All persistent L. monocytogenes PFGE type I isolates were found in an area with high hygienic standards, with the dicing machine being the first point of contamination. These observations show that the dicing machine sustained the contamination and suggest that the dicing machine transferred the persistent L. monocytogenes PFGE type from one plant to another.

Animals↗
PubMed1976

Effect of thyroid hormone on initiation of persistent oestrus in the rat.

When rats are exposed to continuous illumination persistent oestrus and polyfollicular ovaries develop. Thyroidectomy at 24 days of age (juvenile rats) prevents the onset of persistent oestrus and polyfollicular ovaries under exposure to constant light, and irregular ovulation continues to occur. Replacement with 1.75 microng L-thyroxine in these rats produces a prolonged oestrus. However, in adult persistent-oestrous rats (90 days after exposure to continous illumination) thyroidectomy does not interrupt persistent vaginal cornification. In rats receiving 100 microng of testosterone propionate subcutaneously at 5 days of age, persistent oestrus and polyfollicular ovaries develop. Thyroidectomy at 24 days of age (juvenile) prevents the onset of persistent oestrus and the development of polyfollicular ovaries, however, ovulation is not observed. Replacement treatment with 1.75 microng L-thyroxine in these rats produces a prolonged oestrus and polyfollicular ovaries. However, in adult persistent oestrus rats, thyroidectomy at 130 days does not interrup persistent vaginal cornification. From these facts, it may be inferred that circulation of a physiological level of thyroid hormone in juvenile rats is necessary for the development of oestrogen binding receptors in the hypothalamus. Therefore, a hypothyroid state during the juvenile stage interferes with the development and maturation of hypothalamic controlled pituitary ovarian function.

Age Factors↗
PubMed2001

Characteristics of children hospitalized with severe dehydration and persistent diarrhoea in Bangladesh.

The study analyzed data from a systematic sample of children, aged less than five years, who presented with persistent diarrhoea (diarrhoea of more than 14 days duration). It aims to differentiate (a) non-severe persistent diarrhoea (with no or mild dehydration) and (b) severe persistent diarrhoea (with moderate or severe dehydration), and to identify individual characteristics associated with severe persistent diarrhoea. In total, 7,505 patients, who represented a 4% systematic sample of the patient population, were seen during January 1993-December 1995. Of them, 297 (4%) presented with persistent diarrhoea. The male:female ratio was 2:1. Eighty-three percent of them had mild or no dehydration, and 17% had moderate or severe dehydration. Severe malnutrition of the study patients defined as weight-for-age z-score < -3, weight-for-length z-score < -3 and length-for-age z-score < -3 were 33.9%, 9.7%, and 22.7% respectively. Only 3% had oedematous malnutrition, and 11% had xerophthalmia. Factors independently associated with severe persistent diarrhoea by logistic regression analyses were: number of watery stool > 10 times during the last 24 hours prior to admission (OR, 10.0; CI, 1.2-87, p = 0.03), lower respiratory tract infection (OR, 111; CI, 4.2-2955, p = 0.004), and lack of mothers' education (OR, 7.8; CI, 1.4-41.9, p = 0.016) after controlling for confounders. Awareness and health education of mothers or caregivers and better case management during acute diarrhoeal episode might prevent the development of severe persistent diarrhoea in young children. In addition, children with severe persistent diarrhoea might need special attention to have adequate rehydration and control of extraintestinal infections, including respiratory tract infection.

Bangladesh↗
PubMedDate not supplied

[Occupational asthma: role of airway inflammation and remodelling in persistent respiratory symptoms and bronchial hyper-responsiveness].

BACKGROUND: Until the late 1970's occupational asthma (OA) was considered reversible once patients were removed from exposure. Unfortunately, respiratory symptoms and non-specific bronchial hyper-responsiveness (NSBH) persist in about two-thirds of patients for years after removal from the offending agent. OBJECTIVES AND METHODS: This review focuses on the role of airways inflammation and remodelling in persistent respiratory symptoms and NSBH after cessation of occupational exposure. RESULTS: Even though cessation of exposure does not always result in remission of OA, symptoms, airways calibre and NSBH do improve in many patients. Although improvements in FEV1 and NSBH tend to reach a plateau 1-2 years after workers leave exposure, reversing NSBH may take much longer and respiratory symptoms and NSBH can persist in subjects removed from exposurefor >10 yrs. Long-term treatment with inhaled corticosteroids (ICS) induces a small but significant improvement in respiratory symptoms and in quality of life and a decrease in NSBH. Prolonged exposure and respiratory symptoms, marked airway obstruction and NSBH, high total cell, eosinophil and neutrophil counts in bronchoalveolar lavage fluid, a strong reaction during specific inhalation challenge, and delayed treatment with ICS have been identified as prognostic factors of unfavourable outcome. If exposure persists, OA tends to deteriorate in many patients but regular long-term treatment with ICS and long-acting beta2-agonists seems to stabilize the outcome. Soon after the last exposure inflammatory cell infiltrates, including eosinophils, and increased thickness of sub-epithelial collagen have been observed. When time since removal from exposure was longer, persistence of respiratory symptoms and NSBH was associated with airway inflammation, remodelling and hypersensitivity to the offending agent. Thickness of sub-epithelial collagen and specific airway sensitivity were reduced after prolonged non-exposure to isocyanates, although NSBH and airway inflammation persisted. CONCLUSIONS: Pathologic features are similar in OA and non-occupational asthma. The main factors of favourable outcome are early removal from exposure and a mild airway obstruction and NSBH at diagnosis. Persistence of airway inflammation years after removal from exposure suggests this process may become independent of the offending agent. The role of remodelling on persistence of OA needs to be clarified further.

Asthma↗
PubMed2005

Factors predicting persistence of high-risk human papillomavirus (HPV) infections in women prospectively followed-up in three New Independent States (NIS) of the former Soviet Union.

BACKGROUND: We completed an analysis of the factors predicting the persistence of high risk (HR) HPV infections in women participating in a multicenter screening trial in three NIS countries. METHODS: The 543 baseline HR HPV-positive women included in this analysis are derived from a sub-cohort of 887 women who were prospectively followed-up for a mean of 21.6 months (range: 0.5-42.9) as a part of a multi-center screening study in three NIS countries (the NIS cohort study; n = 3,187 women). Of these 543 women, 273 showed persistent HR-HPV in serial Hybrid Capture II (HCII) testing during the follow-up (Group 1), whereas 270 women cleared their infection (Group 2). These two groups were compared with their epidemiological, clinical, and virological data (HCII, PCR) to disclose the factors predicting persistent HR-HPV infection. RESULTS: Women with persistent HR-HPV infections were significantly younger (27.3 yrs) than those who cleared their infection (29.1 yrs) (p = 0.006), and their follow-up time was shorter; 14.1 and 21 months, respectively (p = 0.0001). Both variables were treated as confounders in the multivariate analyses. Of the 66 recorded epidemiological variables, only being a current smoker proved to be an independent predictor (OR 1.693; 95% CI 1.114-2.573; p=0.014). Baseline colposcopy, biopsy or Pap smear did not predict HPV persistence, whereas an incident or persistent abnormal Pap during the follow-up were independent predictors in a multivariate model (p = 0.005), together with the high viral load (HCII RLU/CO at 100 pg/ml cut-off), and HR HPV positive PCR test (p = 0.0001). When all significant variables were entered in the regression model, only the follow-up time (OR 0.950, 95% CI 0.924-0.976; p = 0.0001) and HR-HPV positive PCR (OR 4.169, 95% CI 1.741-9.987; p = 0.001), remained independent predictors. CONCLUSIONS: While several factors were related to HR-HPV persistence in univariate analysis and when adjusted for age and follow-up time as confounders, the only independent predictors in the multivariate regression model were follow-up time and HR-HPV positive PCR. Clearly more data are needed on type-specific persistence and HPV integration as its predictors.

Adult↗
PubMed1989

Persistent bacteremia due to coagulase-negative staphylococci in low birth weight neonates.

During a 6-month period in 1987, 13 low birth weight neonates without indwelling central intravascular catheters had persistent (positive blood cultures for greater than or equal to 6 days) coagulase-negative staphylococcal bacteremia despite adequate antibiotic therapy. Daily blood cultures remained persistently positive for a mean of 13 days (range 6 to 25 days). This group of infants was compared with other low birth weight infants with similar birth weights and nonpersistent coagulase-negative staphylococcal bacteremia, defined as two or more positive blood cultures accompanied by supporting clinical manifestations of sepsis. During this period, coagulase-negative staphylococcal represented 29% of all bacteremias, and 33% of coagulase-negative staphylococcal bacteremias were persistent. Other than soft tissue abscesses, none of the infants with persistent coagulase-negative staphylococcal bacteremia had a defined focus of infection. Abdominal distention (P = .001) and thrombocytopenia (P less than .03) occurred significantly more frequently in the patients with persistent coagulase-negative staphylococcal bacteremia than in those with nonpersistent bacteremia. Of the 13 patients with persistent coagulase-negative staphylococcal bacteremia, 2 received methicillin and 11 received vancomycin. No antibiotic tolerance to either antibiotic could be demonstrated. Serum concentrations of vancomycin far exceeded the minimum bactericidal concentration in all cases in which vancomycin was prescribed. No in vitro differences could be demonstrated between persistent and nonpersistent coagulase-negative staphylococcal strains for slime production, biotype, proteins from modified whole cell lysates developed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and opsonophagocytosis by adult neutrophils in the presence of pooled human sera. Additionally, plasmid profile analysis and phage typing revealed no common strain causing the persistent bacteremia.(ABSTRACT TRUNCATED AT 250 WORDS)

Amikacin↗