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PubMed1986

Effects of prophylactic chemotherapy for persistent trophoblastic disease in patients with complete hydatidiform mole.

Seventy-one patients with complete hydatidiform mole were prospectively randomized into two groups: one group (39 patients) was treated with a single course of methotrexate and citrovorum factor rescue as chemoprophylaxis; the other group (32 patients) was not treated. After molar evacuation, four patients from the treated group (10.3%) and ten patients from the untreated group (31.3%) developed persistent trophoblastic disease. The time interval from evacuation of the mole to diagnosis of persistent trophoblastic disease was longer in the treated group than in the untreated group (9.5 +/- 2.4 weeks versus 5.1 +/- 1.6 weeks, P less than .05). Among high-risk patients, there was a lower incidence of persistent trophoblastic disease in the treated group than in the untreated group (14.3 versus 47.4%, P less than .05). Among low-risk patients there was no difference between the groups (5.6 versus 7.7%, P greater than .05). All 14 patients with persistent trophoblastic disease achieved complete remission with therapeutic chemotherapy. More courses of chemotherapy were required until complete remission in the treated group than in the untreated group (2.5 +/- 0.5 versus 1.4 +/- 0.5, P less than .005). These findings suggest that even though chemoprophylaxis reduces the incidence of persistent trophoblastic disease in patients at high risk, it increases tumor resistance and morbidity. Although prophylactic chemotherapy with methotrexate and citrovorum factor rescue may be helpful for high-risk patients who cannot be followed or whose compliance is in question, careful follow-up remains the most important way to identify patients who should receive chemotherapy.

Adult↗
PubMed1988

Depressed humoral immune responses to surface antigens of Giardia lamblia in persistent giardiasis.

The specific anti-plasma membrane- or surface-specific serum antibodies to Mr 82,000 antigen of Giardia lamblia trophozoites in cases of persistent and nonpersistent giardiasis in a pediatric population indicated significantly low concentrations of these antibodies in patients with persistent giardiasis. There was an insignificant difference in the amount of antibodies to whole trophozoite extract in persistent and nonpersistent giardiasis or asymptomatic carriers. The acute/nonpersistent cases had predominantly IgM class antigiardial antibodies, whereas persistent and asymptomatic carriers had antigiardial antibodies of the IgG class. The inability of persistent cases of giardiasis to clear infection appears to be related to low concentrations of antiplasma membrane/anti-Mr 82,000 antigiardial antibodies.

Animals↗
PubMed1997

Cefprozil treatment of persistent and recurrent acute otitis media.

OBJECTIVE: We identified the pathogens causing persistent and recurrent acute otitis media (AOM) and the clinical efficacy of cefprozil as treatment. STUDY DESIGN: This was a noncomparative, open label multicenter trial. Children ages 6 months to 12 years with signs and symptoms of AOM and evidence of middle ear effusion, as confirmed by pneumatic otoscopy or tympanometry, underwent tympanocentesis and subsequent treatment with cefprozil (15 mg/kg given twice daily) for 10 days. Patients with recurrent otitis media or failure of previous antibiotic therapy or prophylaxis were particularly sought for the study. RESULTS: Two hundred sixty-two (99%) of 265 enrolled children were considered evaluable. The median age of the study group was 1 year. Ninety-eight (37%) of the children had a history (within 30 days) of prior antibiotic use. Ninety-seven (37%) met our definition of recurrent AOM, 48 (18%) met our definition of persistent AOM and 132 (50%) children had 3 or more previous episodes of acute otitis media within 12 months before study. Eighty-two (31%) of the enrollment tympanocentesis had no growth, 150 (57%) had a single bacterial pathogen and 29 (11%) had multiple bacterial pathogens. Of the 93 Streptococcus pneumoniae pretreatment isolates, 50 (54%) were penicillin-susceptible, 12 (13%) were penicillin-intermediate resistant and 31 (33%) were penicillin-resistant. Of the 75 Haemophilus influenzae pretreatment isolates, 42 (56%) produced beta-lactamase as did 4 (27%) of the 15 Moraxella catarrhalis strains. A satisfactory clinical response by pathogen was found in 75% (70 of 93) with S. pneumoniae, 75% (56 of 75) with H. influenzae and 93% (13 of 14) with M. catarrhalis; the response with single pathogen infections was higher than those with multiple pathogens (118 of 150 (78%) and 17 of 29 (59%), respectively; P = 0.03). The response for patients with isolates of S. pneumoniae that were penicillin-susceptible, -intermediate or -resistant were 39 of 50 (78%), 11 of 12 (92%) and 21 of 31 (68%), respectively. Older children had a satisfactory clinical outcome more frequently than younger children (P < 0.001), and the response to therapy varied for persistent, recurrent and recently untreated AOM (P < 0.01). CONCLUSION: Persistent and recurrent AOM involves the same pathogens as recently untreated AOM but bacteria with reduced antibiotic susceptibility may be more frequently present. This noncomparative study suggests that cefprozil 30 mg/kg/day given in two divided doses for 10 days may be effective in the treatment of children with persistent and recurrent AOM.

Acute Disease↗
PubMed1997

Association of torovirus with acute and persistent diarrhea in children.

OBJECTIVE: To study the etiologic role of toroviruses as a cause of gastroenteritis in humans. METHODS: The design was a case-control study. We compared the rate of torovirus detection in fecal specimens from a selection of children with acute or persistent diarrhea and controls without diarrhea from a study of childhood diarrhea in an urban Brazilian slum. Stool samples were coded and tested in a blinded fashion for the presence of torovirus antigen by enzyme-linked immunosorbent assay, other enteropathogens, toxins and fecal leukocytes. RESULTS: Thirty-three children with acute diarrhea, 41 children with persistent diarrhea and 17 controls were enlisted in the study. Torovirus antigen was detected in 9 (27%) samples from children with acute diarrhea, 11 (27%) samples from children with persistent diarrhea and none of the samples from controls (P < 0.05). In addition the presence of enteroaggregative E. coli was associated with persistent diarrhea and the presence of Cryptosporidium oocysts was common although not significant (P = 0.08); torovirus and Cryptosporidium occurred in different subsets of samples, whereas torovirus and enteroaggregative Escherichia coli were commonly found in combination. CONCLUSIONS: These data indicate that toroviruses, alone or in combination with enteroaggregative E. coli, may play a pathogenic role in acute and possibly persistent diarrhea. Further studies are warranted to determine the etiologic role of toroviruses in gastroenteritis.

Acute Disease↗
PubMed1994

Characterization of a persistent inhibitory action of L-364,718 on cholecystokinin-stimulated enzyme secretion in pancreatic acini.

Examining the actions of L-364,718 on rat pancreatic acini, we found that L-364,718 causes persistent inhibition of cholecystokinin (CCK)-8-stimulated enzyme secretion in acini that were first incubated with L-364,718, washed repeatedly, and then reincubated with CCK-8. This inhibition is maximal after as little as 5 s of first incubation with L-364,718, is unaltered by reducing the temperature of the first incubation from 37 to 4 degrees C and is specific for CCK-8 in that carbachol-stimulated enzyme secretion is unaltered. The inhibitory potency of L-364,718 added to the first incubation followed by washing and reincubation with CCK-8 is nearly the same as when L-364,718 is added together with CCK-8 in the same incubation. The persistent inhibitory action of L-364,718 is not attributable to residual free L-364,718 in the bulk phase of the second incubation medium. In addition, L-364,718 does not cause persistent inhibition by binding irreversibly to CCK receptors because the binding reaction is completely reversible and the persistent inhibition can be surmounted with appropriate concentrations of CCK-8. When acini are first incubated with L-364,718 and washed repeatedly, approximately 0.2% of the original L-364,718 remains trapped in a microenvironment within the acini. This trapping presumably results in a sufficiently high concentration of L-364,718 to produce its persistent, albeit surmountable inhibition.

Amylases↗
PubMed2001

Determinants of persistent and recurrent Chlamydia trachomatis infection in young women: results of a multicenter cohort study.

BACKGROUND: Sequelae of genital Chlamydia trachomatis infection in women are more strongly linked to repeat infections than to initial ones, and persistent or subsequent infections foster continued transmission. OBJECTIVE: To identify factors associated with persistent and recurrent chlamydial infection in young women that might influence prevention strategies. METHODS: Teenage and young adult women with uncomplicated C trachomatis infection attending reproductive health, sexually transmitted disease, and adolescent medicine clinics in five US cities were recruited to a cohort study. Persistent or recurrent chlamydial infection was detected by ligase chain reaction (LCR) testing of urine 1 month and 4 months after treatment. RESULTS: Among 1,194 women treated for chlamydial infection, 792 (66.4%) returned for the first follow-up visit, 50 (6.3 %) of whom had positive LCR results. At that visit, women who resumed sex since treatment were more likely to have chlamydial infection (relative risk [RR], 2.0; 95% CI, 1.03-3.9), as were those who did not complete treatment (RR, 3.4; 95% CI, 1.6-7.3). Among women who tested negative for C trachomatis at the first follow-up visit, 36 (7.1%) of 505 had positive results by LCR at the second follow-up visit. Reinfection at this visit was not clearly associated with having a new sex partner or other sexual behavior risks; new infection was likely due to resumption of sex with untreated partners. Overall, 13.4% of women had persistent infection or became reinfected after a median of 4.3 months, a rate of 33 infections per 1,000 person months. CONCLUSIONS: Persistent or recurrent infection is very common in young women with chlamydial infection. Improved strategies are needed to assure treatment of women's male sex partners. Rescreening, or retesting of women for chlamydial infection a few months after treatment, also is recommended as a routine chlamydia prevention strategy.

Adolescent↗
PubMed2004

Factors related to the onset and persistence of chronic back pain in the community: results from a general population follow-up study.

INTRODUCTION: We compared the prevalence of chronic back pain (CBP) at two points 4 years apart and examined socio-demographic, health, and pain-related factors associated with its onset and persistence. METHOD: A random population sample of 2,184 adults was surveyed in 1996 and resurveyed in 2000. The questionnaire included chronic pain case definition questions (pain for 3 months or longer); the cause (1996) or site (2000) of any chronic pain; the Chronic Pain Grade questionnaire; the Level of Expressed Need (LEN) questionnaire; the SF-36 general health questionnaire; and demographic questions. Those with CBP in 1996 and 2000 had "persistent" CBP; those with CBP in 1996 but not 2000 had "recovered" CBP; those with CBP in 2000 but not 1996 had "new" CBP. RESULTS: Corrected response rates were 82.3% (1996) and 83.0% (2000). The sample prevalence of CBP was 16% (1996) and 27% (2000). Factors in 1996 independently associated with "persistent" compared with "recovered" CBP were preexisting arthritis, high LEN, poor mental health, and not living alone. Factors independently predicting "new" CBP compared with no previous CBP were previous chronic pain elsewhere and poor physical health. "Persistent" CBP was associated with more severe pain, higher LEN, and poorer general health than "new" CBP. DISCUSSION: CBP is a common and lasting problem, whose persistence and onset are predicted by clinical (especially pain) and help-seeking behavior factors, rather than socio-demographic. Prevention should focus on these factors.

Adult↗
PubMed2005

Evaluation of a new DNA test compared with the lactose hydrogen breath test for the diagnosis of lactase non-persistence.

BACKGROUND AND AIMS: Recent publications have found that the CC genotype of the DNA variant -13910 T/C upstream of the LCT gene is associated with lactase non-persistence. We therefore compared the value of DNA testing for this variant (DNA test) with the lactose hydrogen breath test (H2 test), which is the clinical standard for the diagnosis of lactase non-persistence. PATIENTS AND METHODS: One hundred and twenty-three consecutive patients with suspected lactose malabsorption were tested for the presence of the -13910 T/C variant by polymerase chain reaction-restriction fragment length polymorphism analysis. These patients also underwent the H2 test after ingestion of 50 g lactose. RESULTS: Thirty-seven subjects had a CC genotype of the -13910 T>C polymorphism suggesting lactase non-persistence; 36 (97%) had also a positive H2 test. Eighty-six subjects had either a TC or a TT genotype suggestive of lactase persistence. Seventy-four (86%) of these tested negative on the H2 test, while 12 patients had a positive H2 test. In eight of these 12 patients duodenal biopsies showed no evidence of small bowel disease. One patient carrying a CC genotype had a negative H2 test. In this patient the rise in serum glucose after oral lactose was normal, furthermore H2 non-excretion was also excluded. CONCLUSIONS: An excellent correlation is observed between a CC genotype and a positive H2 test, whereas the correlation between a TC or TT genotype and a negative H2 test result is less strong. Analysis of the -13910 T/C variant can be considered a good test for predicting the presence of lactase non-persistence in a patient population with suspected lactose malabsorption.

Adolescent↗
PubMed2003

Persistence of psychiatric disorders in pediatric settings.

OBJECTIVE: To examine the longitudinal course of subthreshold and full-criteria child psychiatric disorders. METHOD: Nine hundred ninety-six children, aged 4 to 9 years, from a representative sample of pediatric primary care practices participated in a 1-year follow-up in 1989-1990. Parent interviews included the Diagnostic Interview Schedule for Children, measures of psychosocial problems, stress, social support, possible child abuse, and sociodemographics. RESULTS: The initial prevalence of full and subthreshold disorders was 18.8% and 14.0%, respectively. Full and subthreshold disorders were associated with impairment. Approximately 37% of children with full disorders had persistent disorders. Persistence was more common among boys than girls, particularly when comorbidity was present. Children with initial subthreshold disorders only were five times more likely than those without disorder to develop a full disorder. Persistence of full disorders was associated with high initial symptoms. Among boys, persistence was linked to possible child abuse, whereas among girls it was associated with full externalizing disorders that were accompanied by subthreshold internalizing disorders. CONCLUSIONS: Intervention may be particularly crucial when a high number of symptoms and/or both internalizing and externalizing problems are present. Underscoring the importance of family-centered rather than child-centered interventions, boys whose parents reported possible child abuse were more likely to have persistent disorders.

Child↗
PubMed2005

Rate and determinants of 10-year persistence with antihypertensive drugs.

OBJECTIVE: To assess the proportion of patients starting with antihypertensive drug treatment who continued treatment for at least 10 years. DESIGN: A retrospective cohort study. SETTING: The PHARMO record linkage system containing drug dispensing records from community pharmacies and linked hospital discharge records of approximately 950 000 subjects. PARTICIPANTS: Patients who started using antihypertensive drugs (two or more prescriptions) in 1992 and did not receive a prescription for any antihypertensive drug in the 365 days preceding the first prescription. MAIN OUTCOME MEASURE: Persistence with antihypertensive drugs until 10 years. RESULTS: Among a total of 2325 patients who started using antihypertensive drugs, 39% used continuously during the 10 years of follow-up. Approximately 22% temporarily discontinued and restarted treatment, whereas 39% of patients discontinued permanently. Older patients were more persistent than younger patients [20-39 years: odds ratio (OR) 2.08; 95% confidence interval (CI) 1.52-2.84; 40-59 years: (reference), > or = 60 years: OR 0.69; 95% CI 0.54-0.89]. More patients who started with diuretics (reference) and beta blockers (OR 1.15; 95% CI 0.87-1.52) discontinued compared with those who started with dihydropyridine calcium antagonists (OR 0.54; 95% CI 0.34-0.84), and angiotensin-converting enzyme (ACE) inhibitors (OR 0.38; 95% CI 0.27-0.55). Patients who started with combination therapy (OR 0.29; 95% CI 0.14-0.54 compared with diuretics) or patients who were initially treated by a cardiologist (OR 0.82; 95% CI 0.61-0.97) or internist (OR 0.80; 95% CI 0.62-0.98 compared with general practitioners) also showed higher persistence. CONCLUSION: Long-term persistence in daily practice is low compared with persistence observed in randomized clinical trials and should be considered in the choice of a first-line antihypertensive agent.

Adrenergic beta-Antagonists↗
PubMed2004

Dramatic healing of an allergic corneal ulcer persistent for 6 months by amniotic membrane patching in a patient with atopic keratoconjunctivitis: a case report.

PURPOSE: To present a case of allergic corneal ulcer in a patient with atopic keratoconjunctivitis (AKC) that was persistent for 6 months and healed by amniotic membrane patching. CASE REPORT: A 27-year-old male patient with a corneal ulcer associated with AKC persistent for 6 months despite conventional treatment underwent amniotic membrane patching. On removal of the amniotic membrane patch after 1 week, the corneal ulcer that had been persistent for 6 months had healed completely. CONCLUSION: We experienced a case with corneal ulcer that was persistent for 6 months and healed dramatically within 1 week with improved vision and corneal clarity. In such severe and persistent cases requiring rapid epithelialization, amniotic membrane should be considered as an adjunct to conventional therapy.

Adult↗
PubMed2006

Tuberculous lymphadenitis as a cause of persistent cervical lymphadenopathy in children from a tuberculosis-endemic area.

BACKGROUND: Cervical lymphadenitis is the most common form of extrapulmonary tuberculosis in children, although its relative contribution as a cause of persistent cervical adenopathy is not well-documented. The aim of this study was to determine the relative contribution of tuberculous lymphadenitis as a cause of persistent cervical adenopathy in a tuberculosis-endemic setting and to document its clinical presentation at the primary health care level. METHODS: A prospective descriptive study was conducted from February 2003 through October 200 at 5 primary health care clinics in Cape Town, South Africa. The study included all children younger than 13 years presenting with persistent cervical adenopathy to the local primary health care clinic. RESULTS: A total of 158 children were evaluated of whom 35 (22.2%) were diagnosed with tuberculous lymphadenitis. Bacteriologic confirmation was achieved in 27 of 35 (77.1%) children; all 35 responded to standard antituberculosis treatment. The majority of those without tuberculous lymphadenitis (105 of 123, 85.4%) had a visible superficial lesion in the area drained by the affected nodes. In children with persistent lymphadenopathy > or =2 x 2 cm, tuberculosis lymphadenitis was diagnosed in 31 of 33 (93.9%); specificity was 98.4%, sensitivity was 88.6% and the positive predictive value was 93.4%. CONCLUSION: Children commonly present with persistent cervical adenopathy to the primary health care clinic. The use of a simple clinical algorithm provided an accurate diagnosis of tuberculous lymphadenitis in the study setting. Fine needle aspirations provided a rapid and definitive diagnosis in the majority of children and will have added diagnostic value in settings where alternative diagnoses are more likely.

Algorithms↗
PubMed2004

Whooping cough metapopulation dynamics in tropical conditions: disease persistence and impact of vaccination.

Recent insights in compiling metapopulation models and infectious disease dynamics have enabled a better understanding of spatial and temporal persistence of diseases. The concept of the critical community size (CCS) has been developed with major consideration on analyses of whooping cough and measles dynamics from temperate countries for which large datasets are available. However, few studies have questioned the generality of CCS curves for other regions, i.e. tropical areas, mainly because data are very sparse. This work constitutes, to our knowledge, the first study of whooping cough persistence in a tropical area, in a rural part of Senegal (Western Africa) where the population has been followed for 20 years. In this small community, the CCS is not reached even if we observe CCS-like curves showing persistence increasing with population size. In addition, our analysis supports the idea that vaccination has impacted the spatiotemporal dynamics and persistence of the disease. These findings suggest the need for more comparative analyses of spatio-temporal data series from a wide range of contrasted countries, for example developed and developing nations, so as to have a better understanding of vaccination effects on disease dynamics and persistence.

Humans↗
PubMed1994

Inactivation-resistant channels underlying the persistent sodium current in rat ventricular myocytes.

Single-channel sodium currents that could be blocked with TTX were elicited by depolarizing voltage pulses in either cell-attached or inside-out patches from rat ventricular myocytes. A transient burst of channels was followed by late-opening (persistent) channels with low open probability. Conditioning depolarizing pre-pulses that inactivated transient channels and 'chattering' late-opening channels had no effect on persistent channels. The open probability of persistent channels reached a maximum at more negative potentials than transient channels. Between -70 mV and -40 mV, the average open time of persistent channels increased, whereas the average open time of transient channels did not change significantly, so the open times of the two channels diverged as the potential became more positive. The conductance of transient and persistent channels was similar, and the conductance of both kinds of channel increased at more depolarized potentials.

Animals↗
PubMed2006

Modelling population persistence on islands: mammal introductions in the New Zealand archipelago.

Islands are likely to differ in their susceptibility to colonization or invasion due to variation in factors that affect population persistence, including island area, climatic severity and habitat modification. We tested the importance of these factors in explaining the persistence of 164 introductions of six mammal species to 85 islands in the New Zealand archipelago using survival analysis and model selection techniques. As predicted by the theory of stochastic population growth, extinction risk was the greatest in the period immediately following introduction, declining rapidly to low probability by ca 25 years. This suggests that initially small populations were at greatest risk of extinction and that populations which survived for 25 years were likely to persist subsequently for much longer. Islands in the New Zealand archipelago become colder and windier with increasing latitude, and the probability of mammal populations persisting on islands declined steeply with increasing latitude. Hence, our results suggest that climatic suitability was an important determinant of the outcome of these invasions. The form of the relationship between latitude and persistence probability differed among species, emphasizing that the outcome of colonization attempts is species-environment specific.

Animals↗
PubMed1975

The production of a temperature-sensitive persistent measles virus infection.

A persistent infection of measles virus was established in HEp2 cells. All cells contained virus antigen when tested by specific immunofluorescence and approx. 50% were positive by haemadsorption. Infectious virus released into the supernatant medium was usually equivalent to no more than 0-001 p.f.u./cell, but between 10 and 40% of the infected cells produced plaques when plated on Vero cells. Passage of persistently infected cultures in the presence of measles antibody had no effect on the proportion of antigen-positive cells. Virus obtained from the supernatant medium of persistently infected cultures was temperature sensitive at 39-5 degrees C when tested on Vero cells whereas the original non-persistent virus produced infections on Vero cells at 39-8 degrees C. On passage of the persistently infected culture at 39-5 degrees C most of the surface antigens disappeared within 24 h whereas the intracellular virus antigens had not totally disappeared until the 5th passage.

Antigens, Viral↗
PubMed1976

Characterization of measles viruses in establishment of persistent infections in human lymphoid cell line.

Human lymphoid cells (NC-37) were infected with attenuated measles vaccine virus (Schwarz, AIK-C, and CAM-70 strains), subacute sclerosing panencephalitis virus (Mantooth and Halle strains), neurovirulent TYCSA strain, and wild type virus (Edmonston and Toyoshima strains) at an input multiplicity of 0-01. These strains were divided into two groups by their capacity to establish carrier states. CAM-70, Toyoshima, and Edmonston strains did not set up persistent infections in NC-37 cells, whereas AIK-C strain induced chronic cyclic infection and the Schwarz, TYCSA, Mantooth and Halle strains could set up persistent infections and furthermore two types of persistent infections were recognizable. Cells persistently infected with Schwarz strain contained nucleocapsid structures in both nucleus and cytoplasm, and produced infectious virus of 10(4) to 10(5) p.f.u./ml over 100 days after the inoculation of the virus but the cap-formation of measles antigens on the cell membrane was seldom observed. However, in cells persistently infected with TYCSA strain, nucleocapsid structures were rarely observed in the nucleus, but the cap-formation of measles antigens on the cell membrane was often observed. The titre of carried virus was always higher than the number of cells in the range of 10(6) to 10(7) p.f.u./ml. Mantooth strain was similar to Schwarz strain and Halle strain was similar to TYCSA strain in the properties of their carrier states. These carrier states were stable and the cells grew normally for over one year.

Antigens, Viral↗
PubMed1979

Comparison of the antigens produced by foamy virus in a cytolytic and a persistent infection of HEp2 cells.

The antigens from cytolytic infections of HEp2 cells by type I simian foamy virus produced two multicomponent precipitation lines when tested by immunodiffusion with the homologous hyperimmune rabbit antiserum. The antigens obtained from a non-productive infection of MK5 virus in HEp2 cells produced only those precipitation lines which corresponded with the inner lines obtained from the cytolytic infection. Similarly, hyperimmune rabbit antiserum against antigens extracted from the persistent infection lacked the antibody which was responsible for the outer lines of precipitation. Indirect immunofluorescence with acetone-fixed and unfixed cells using the homologous and heterologous sera confirmed the absence of antigens in the persistent infection and showed that an antigen is produced in the persistently infected cells which is either absent or present in very small amounts in cytolytically infected cells. Neutralization experiments and ether treatment suggested that the missing antigens in the persistent infection were the envelope components of foamy virus. It is proposed that the persistent infection has properties in common with some infections by RNA tumour viruses.

Antigens, Viral↗