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PubMed1989

Ureaplasmal pneumonia and sepsis associated with persistent pulmonary hypertension of the newborn.

Ureaplasma urealyticum was isolated from the lower respiratory tract of three infants with persistent pulmonary hypertension of the newborn. In one, cultures positive for U urealyticum were obtained on multiple occasions from trachea, blood, and pleural fluid prior to the infant's death on postnatal day 6. Autopsy findings confirmed the presence of severe pneumonia and the organism was again recovered from multiple sites. A second infant had no apparent predisposing factors for development of persistent pulmonary hypertension of the newborn but U urealyticum and Staphylococcus epidermidis were recovered from the trachea antemortem and from lung tissue obtained during autopsy on the 12th postnatal day. The third infant had persistent pulmonary hypertension of the newborn and a pulmonary infiltrate within hours after birth with tracheal cultures positive for both U urealyticum and Mycoplasma hominis. Erythromycin was given for ten days, and the infant gradually improved. Prolonged ventilation with supplemental oxygen was necessary, and chronic lung disease developed. This is the first report of neonatal ureaplasmal pneumonia with sepsis and persistent pulmonary hypertension of the newborn as well as the first time a microorganism other than streptococci has been specifically implicated in the pathogenesis of persistent pulmonary hypertension of the newborn. Respiratory infections with U urealyticum or other bacteria should be considered as possible causative or contributory factors in infants with persistent pulmonary hypertension of the newborn.

Female↗
PubMed2005

Surgical treatment of persistent macrocheilia in patients with Melkersson-Rosenthal syndrome and cheilitis granulomatosa.

BACKGROUND: Various conservative methods for treatment of labial swelling in patients with cheilitis granulomatosa have been attempted, often with only moderate success and sometimes with persistent disfiguring lip swelling. Severe macrocheilia can produce an unaesthetic facial deformity associated with functional disturbances. In patients with persistent macrocheilia, reduction cheiloplasty with excision of excess tissue may be indicated when conservative treatment has proven ineffective in reducing swelling but may have been successful in stabilizing disease. OBJECTIVE: To evaluate long-term results after reduction cheiloplasty in patients with macrocheilia caused by Melkersson-Rosenthal syndrome or cheilitis granulomatosa. DESIGN: Follow-up study in 7 patients with severe persisting macrocheilia, including 3 patients with Melkersson-Rosenthal syndrome and 4 patients with cheilitis granulomatosa in a stable state of disease, treated by reduction cheiloplasty at our hospital between January 1, 1987, and December 31, 2002. Preoperative and postoperative medical histories were obtained, and criteria for the success of surgical treatment were evaluated by clinical examination. Different techniques of reduction cheiloplasty are described and demonstrated in representative cases of severe macrocheilia. RESULTS: Surgical treatment in all 7 patients showed satisfying aesthetic and functional outcomes that persisted throughout follow-up (median follow-up, 6.5 years). CONCLUSIONS: Reduction cheiloplasty is an effective method to correct persistent macrocheilia and improve lip aesthetics in patients with Melkersson-Rosenthal syndrome or granulomatous cheilitis in the persistent state of disease. With careful planning, proper sequencing of treatment, and proficiency in the various surgical techniques, optimal results can be achieved.

Adolescent↗
PubMed2000

Relationship between persistence of abdominal symptoms and successful outcome after cholecystectomy.

BACKGROUND: Patients frequently have persistent abdominal symptoms after undergoing cholecystectomy. The relationship between abdominal symptoms and biliary dysfunction is often unclear. OBJECTIVES: To describe the persistence rate of abdominal symptoms in a large cohort of patients after elective cholecystectomy, to identify predictors of symptom persistence and operative success, to understand which symptoms improve after cholecystectomy, and to describe the important determinants of an unsuccessful operation. METHODS: Secondary analysis of a prospective, multisite cohort study of 2481 patients undergoing elective cholecystectomy. RESULTS: The mean +/- SD number of abdominal symptoms per patient decreased from 3.1 +/- 2.0 to 1.1 +/- 1.3; 27% of patients who identified a symptom as most bothersome before surgery still had the symptom 6 months after surgery. Symptom persistence rates ranged from 5.6% (vomiting) to 40.2% (gas/flatulence). A balance score that quantified the abdominal symptom mix between dyspeptic and biliary symptoms shifted after surgery to the dyspeptic category. Predictors of persistence of a most bothersome symptom were dyspeptic symptom category, worse operative risk and self-rated health status, symptom duration longer than 6 months, and no previous episodes of acute cholecystitis. The major correlate of not achieving a very successful outcome (15.2% of patients) was the presence of postoperative abdominal pain. Other predictors included worse self-rated health status and physical functioning, symptom duration longer than 6 months before surgery, and no previous episodes of acute cholecystitis. CONCLUSIONS: Symptoms categorized as dyspeptic were more likely to persist than were biliary symptoms, although all symptoms showed a decrease in prevalence after cholecystectomy. More attention to the rationale for gallbladder removal and clarification of patient expectations for symptom relief might be necessary to improve outcomes after elective cholecystectomy.

Adolescent↗
PubMed2006

Association of persistent right ventricular dysfunction at hospital discharge after acute pulmonary embolism with recurrent thromboembolic events.

BACKGROUND: In patients with acute pulmonary embolism, right ventricular dysfunction (RVD) on hospital admission is a predictor of adverse short-term clinical outcome. The aim of this study was to evaluate the prognostic value of RVD persistence at hospital discharge with regard to the likelihood of recurrent venous thromboembolism (VTE). METHODS: Echocardiography was used to assess RVD on admission and before hospital discharge in 301 consecutive patients with the first episode of acute pulmonary embolism occurring from January 1998 through July 2004. Right ventricular dysfunction was diagnosed in the presence of 1 or more of the following: right ventricular dilation (without hypertrophy), paradoxical septal systolic motion, and Doppler evidence of pulmonary hypertension. Patients were followed up at 2, 6, and 12 months and yearly thereafter. The primary end point was symptomatic, recurrent fatal or nonfatal VTE. RESULTS: Patients were categorized as those (1) without RVD (155 patients [51.5%]), (2) with RVD regression (RVD on admission but not at discharge; 87 patients [28.9%]), and (3) with persistent RVD (RVD on admission and at discharge; 59 patients [19.6%]). After a mean +/- SD of 3.1 +/- 2.7 years, patients with RVD persistence showed an increased risk of recurrent VTE (14 patients, 9.2% patient-years) compared with those without RVD (15 patients, 3.1% patient-years) or RVD regression (3 patients, 1.1% patient-years) (P = .001). Six of 8 deaths related to pulmonary embolism occurred in patients with RVD persistence. At multivariate analysis, adjusted by anticoagulant treatment duration, RVD persistence was an independent predictor of recurrent VTE (hazard ratio, 3.79; P<.001). CONCLUSION: Persistent RVD at hospital discharge after an acute pulmonary embolism is associated with recurrent VTE.

Acute Disease↗
PubMed1990

Persistent and recurrent neovascularization after krypton laser photocoagulation for neovascular lesions of age-related macular degeneration. Macular Photocoagulation Study Group.

The persistence and recurrence of choroidal neovascularization after initial treatment with laser photocoagulation have been shown to be major contributors to loss of visual acuity. The 247 eyes assigned to krypton red laser photocoagulation in the Age-Related Macular Degeneration Study-Krypton Laser were examined to describe the incidence, timing, visual impact, and potential risk factors for persistence and recurrence. Persistent neovascularization detected within 6 weeks of initial treatment was observed in 32% of treated eyes, and recurrent neovascularization was estimated by life-table methods to develop in an additional 47% over a 5-year period. Both persistence and recurrence were accompanied by an increased frequency of severe visual loss. The persistence rate among eyes having 10% or more of the foveal side of the neovascular membrane not covered by treatment was twice as high as in eyes having more extensive coverage. Patients having a fellow eye with a neovascular membrane or scar, a fellow eye with 20 or more drusen in the central macula, or a fellow eye with nongeographic atrophy at initial visit had more recurrences than patients without these characteristics. Ophthalmologists treating similar lesions may be able to reduce persistent neovascularization and the associated visual loss by covering the entire lesion with treatment.

Age Factors↗
PubMed2000

Are signs and symptoms associated with persistent corneal abrasions in children?

BACKGROUND: Corneal abrasions are common eye injuries in children. Most are treated with antibiotic drops or ointment, patching of the affected eye, and follow-up within 24 hours to confirm resolution by fluorescein examination. OBJECTIVE: To determine if signs and symptoms at follow-up were associated with the presence of a persistent corneal abrasion or abnormal visual acuity. DESIGN: Retrospective case series. SETTING: A children's hospital. PATIENTS: Children who were aged 4 years or older with the diagnosis of corneal abrasion between May 1992 and December 1996 and who had a follow-up examination. RESULTS: Seventy-seven patients (57% male) were enrolled (median age, 7 years). The respective sensitivities, specificities, positive predictive values, and negative predictive values of selective signs and symptoms for persistent abrasions were as follows: for pain, 53%, 93%, 80%, and 80%; for photophobia, 57%, 100%, 100%, and 80%; for redness, 100%, 46%, 44%, and 100%; for pain and redness, 40%, 96%, 80%, and 80%; and for at least 1 sign or symptom, 95%, 48%, 47%, and 95%. Twenty-six patients had persistent corneal abrasions at follow-up. Six of these 26 patients were symptom free at follow-up, and 15 patients had only redness as a persistent sign. Five patients had abnormal visual acuity, one of whom was asymptomatic. All 3 patients with complications were symptomatic. CONCLUSIONS: Signs and symptoms are inconsistently associated with persistent corneal abrasions. Asymptomatic patients may have persistent corneal abrasions, suggesting the need for selective follow-ups.

Adolescent↗
PubMed1986

Persistent tardive dyskinesia in bipolar patients.

The prevalence and outcome of persistent tardive dyskinesia (TD) was studied in 131 bipolar patients. There were 34 cases of persistent TD in the subgroup (n = 96) with a history of neuroleptic treatment (prevalence, 35.4%; 95% confidence interval, 25% to 45%); there were no cases of persistent TD in the subgroup (n = 35) without such treatment history. Except in one patient, signs of TD persisted in spite of lithium carbonate treatment in 23 patients (median duration, 16 months; range, five to 24 months), of whom 15 remained off of a neuroleptic regimen during the study period for a median duration of 14 months (range, four to 24 months). Using multiple regression analysis, two variables were found to predict the presence of persistent TD and account for 36% of the variance: longer cumulative duration of maintenance neuroleptic treatment and shorter duration of previous lithium carbonate treatment. There appears to be a significant risk of persistent TD among neuroleptic-treated bipolar patients. High-risk subgroups within this category need to be identified.

Adult↗
PubMed2001

Persistent human papillomavirus infection as a predictor of cervical intraepithelial neoplasia.

CONTEXT: Human papillomavirus (HPV) infection is believed to be the central cause of cervical cancer, although most of the epidemiological evidence has come from retrospective, case-control studies, which do not provide information on the dynamics of cumulative or persistent exposure to HPV infection. OBJECTIVE: To assess the risks of cervical neoplasia related to prior persistent HPV infections. DESIGN AND SETTING: Longitudinal study of the natural history of HPV infection and cervical neoplasia in women residing in the city of São Paulo, Brazil, which was conducted between November 1993 and March 1997 and involved repeated measurements of HPV and lesions with follow-up until June 2000. PARTICIPANTS: A total of 1611 women with no cytological lesions at enrollment and HPV test results available from the first 2 visits. MAIN OUTCOME MEASURE: Cervical specimens taken for Papanicolaou cytology and HPV testing every 4 months in the first year and twice yearly thereafter. Incident cervical cancer precursor lesions ascertained by expert review of all cytology smears. RESULTS: The incidence rate of squamous intraepithelial lesions (SILs) was 0.73 per 1000 women-months (95% confidence interval [CI], 0.5-0.9) among women free of HPV at the 2 initial visits and 8.68 (95% CI, 2.3-15.1) among women with HPV type 16 or 18 infections persisting over both visits. Relative to those negative for HPV oncogenic types at both initial visits, the relative risk (RR) of incident SIL was 10.19 (95% CI, 5.9-17.6) for persistent infections with any known oncogenic HPV types. The equivalent RR of incident high-grade SIL was 11.67 (95% CI, 4.1-33.3). The RRs of lesions were considerably higher for persistent infections with HPV type 16 or 18. CONCLUSION: A strong relationship exists between persistent HPV infections and SIL incidence, particularly for HPV types 16 and 18.

Adult↗
PubMedDate not supplied

Long-term persistence in use of statin therapy in elderly patients.

CONTEXT: Knowledge of long-term persistence with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) therapy is limited because previous studies have observed patients for short periods of time, in closely monitored clinical trials, or in other unrepresentative settings. OBJECTIVE: To describe the patterns and predictors of long-term persistence with statin therapy in an elderly US population. DESIGN, SETTING, AND PATIENTS: Retrospective cohort study including 34 501 enrollees in the New Jersey Medicaid and Pharmaceutical Assistance to the Aged and Disabled programs who were 65 years of age and older, initiated statin treatment between 1990 and 1998, and who were followed up until death, disenrollment, or December 31, 1999. MAIN OUTCOME MEASURES: Proportion of days covered (PDC) by a statin in each quarter during the first year of therapy and every 6 months thereafter; predictors of suboptimal persistence during each interval (PDC <80%) were identified using generalized linear models for repeated measures. RESULTS: The mean PDC was 79% in the first 3 months of treatment, 56% in the second quarter, and 42% after 120 months. Only 1 patient in 4 maintained a PDC of at least 80% after 5 years. The proportion of patients with a PDC less than 80% increased in a log-linear manner, comprising 40%, 61%, and 68% of the cohort after 3, 12, and 120 months, respectively. Independent predictors of poor long-term persistence included nonwhite race, lower income, older age, less cardiovascular morbidity at initiation of therapy, depression, dementia, and occurrence of coronary heart disease events after starting treatment. Patients who initiated therapy between 1996-1998 were 21% to 25% more likely to have a PDC of at least 80% than those who started in 1990. CONCLUSIONS: Persistence with statin therapy in older patients declines substantially over time, with the greatest drop occurring in the first 6 months of treatment. Despite slightly better persistence among patients who began treatment in recent years, long-term use remains low. Interventions are needed early in treatment and among high-risk groups, including those who experience coronary heart disease events after initiating treatment.

Aged↗
PubMed1999

Apolipoprotein A-IV-2 allele: association of its worldwide distribution with adult persistence of lactase and speculation on its function and origin.

Apolipoprotein A-IV (apo A-IV) is a 46-Kd plasma glycoprotein that may play a major role in intestinal lipid absorption. A genetic polymorphism in the apo A-IV gene, apo A-IV-2, encodes a His-->Gln substitution at codon 360 that alters the biological function of this apolipoprotein. As the worldwide distribution of the apo A-IV-2 allele appeared similar to the frequency of a genetic polymorphism that determines the persistence of lactase into adulthood, we examined the relationship between the apo A-IV-2 and lactase persistence polymorphisms by compiling the prevalence of adult lactase persistence in all populations in which the frequency of the apo A-IV-2 allele has been determined. Across 29 groups, there was an extremely strong correlation (4 = 0.937, P < 0.000001) between apo A-IV-2 allele frequency and the prevalence of adult lactase persistence. Apo A-IV-2 allele frequency was highest in Iceland, an ancient Viking colony, and decreased across Europe in a north-to-south and west-to-east gradient, generally following hypothetical isoclines for the lactase persistence gene. There were no correlations between the population frequencies of the apo E2, E3, or E4 alleles and either the prevalence of lactase persistence or the frequency of the apo A-IV-2 allele. In light of the effects of the apo A-IV-2 polymorphism on lipid metabolism, we speculate that the apo A-IV-2 allele may have originated in ancient Scandinavia, spread by conferring a nutritional advantage in the setting of a lifelong high milkfat intake, and was later carried southwards by the Viking incursions into Europe.

Alleles↗
PubMed2005

Impact of persistent hip or knee pain on overall health status in elderly people: a longitudinal population study.

OBJECTIVE: To investigate hip or knee symptoms in older persons from a longitudinal, population perspective, and to determine the impact of persistent hip or knee pain on general health status over time. METHODS: A postal questionnaire was sent to a random sample of 5,500 individuals ages > or = 65 years containing the Short Form 36 (SF-36) general health survey, Lequesne hip and knee indices, and a hip/knee pain severity item. Respondents reporting hip or knee symptoms at baseline received an identical questionnaire 12 months later. Respondents were classified into a persistent pain group with either hip or knee pain at both baseline and followup, and a non-persistent pain group who reported hip or knee pain at baseline but no pain at followup. RESULTS: At baseline, 1,305 (40.7%) of 3,210 eligible respondents reported hip or knee pain. At 1 year, 1,072 (82.1%) of 1,305 individuals responded, of whom 820 (76.5%) remained symptomatic (the persistent group). In multivariate analysis, baseline factors identified as strongly related to having persistent pain were maximum Lequesne score (odds ratio [OR] 1.09, P < 0.001), maximum hip/knee pain score (OR 1.61, P < 0.001), and number of painful hip and knee joints at baseline (OR 1.48, P = 0.004). Following adjustment for age, sex, and baseline score, differences in mean SF-36 change scores of the 2 groups were significant for all dimensions except for mental health. CONCLUSION: In older persons, a symptomatic hip or knee frequently progresses in terms of worsening symptoms and accrual of other symptomatic hip or knee joints. The impact of persistent symptoms on general health is substantial.

Aged↗
PubMed2006

Sox3 expression identifies neural progenitors in persistent neonatal and adult mouse forebrain germinative zones.

Neural precursors persist throughout life in the rodent forebrain subventricular zone (SVZ) and hippocampal dentate gyrus. The regulation of persistent neural stem cells is poorly understood, in part because of the lack of neural progenitor markers. The Sox B1 subfamily of HMG-box transcription factors (Sox1-3) is expressed by precursors in the embryonic nervous system, where these factors maintain neural progenitors in an undifferentiated state while suppressing neuronal differentiation. Sox2 expression persists in germinative zones of the adult rodent brain, but Sox3 expression in the postnatal brain remains largely unexplored. Here we examine Sox3 expression in the neonatal and adult mouse brain to gain insight into its potential involvement in regulating persistent neural stem cells and neurogenesis. We also investigate Sox3 expression during expansion and neural differentiation of postnatal mouse SVZ neural stem cell and human embryonic stem cell (hESC) cultures. We find that Sox3 is expressed transiently by proliferating and differentiating neural progenitors in the SVZ-olfactory bulb pathway and dentate gyrus. Sox3 immunoreactivity also persists in specific postmitotic neuronal populations. In vitro, high Sox3 protein expression levels in undifferentiated, SVZ-derived neurospheres decline markedly with differentiation. Sox3 immunoreactivity in hESCs appears upon differentiation to neural progenitors and then decreases as cells differentiate further into neurons. These findings suggest that Sox3 labels specific stages of hESC-derived and murine neonatal and adult neural progenitors and are consistent with a role for Sox3 in neural stem cell maintenance. Persistent Sox3 expression in some mature neuronal populations suggests additional undefined roles for Sox3 in neuronal function.

Animals↗
PubMed1989

Genetic epidemiology of persistent islet cell antibodies among IDDM patients.

The persistence of cytoplasmic islet cell antibodies (ICA) more than a year after diagnosis of insulin-dependent diabetes mellitus (IDDM) was investigated in 43 families with at least two children with IDDM. The prevalence of persistent ICA among IDDM patients was 16%. Persistence of ICA appeared to be familial in that siblings with IDDM were significantly more concordant for the presence or for the absence of ICA than expected by chance (P = 0.04). Patients with persistent ICA were older on average at onset of IDDM than patients without persistent ICA after adjusting for duration of disease (P = 0.004). Persistence of ICA was not significantly associated with HLA DR type, immunoglobulin genotype, insulin allele class, sex, history of viral diseases, or prior vaccinations.

Autoantibodies↗
PubMed1977

A persistent infection of baby hamster kidney-21 cells with mumps virus and the role of temperature-sensitive variants.

A persistent infection of baby hamster kidney-21 (BHK-21) cells with mumps virus (BHKpi) was maintained for over 60 cell passages in the absence of antiserum. Viral persistence was demonstrated in the cultures by hemadsorption, immunofluorescence, multinucleate syncytia, and released mumps virus at the level of 10(2)--10(3) fluorescent focus-forming units/ml. No detectable levels of interferon were found in cultures persistently infected with mumps virus. Approximately 85--95% of the cells contained viral antigens. Nuclear fluorescence was observed in the persistently infected cells. Mumps virus from persistently infected clutures (MuVpi) was more heat-labile than wild-type mumps (MuVo) when subjected to 40 degrees C. BHKpi cells had a more rapid doubling time and a higher cloning efficiency in soft agar in comparison to BHK-21 cells. MuVpi was also found to be temperature-sensitive. The temperature-sensitivity of MuVpi was determined by the efficiency of plating at 33 degrees and 39 degrees C. MuVpi readily established a persistent infection in BHK-21 cells with less cytopathology than MuVo, and released temperature-sensitive virus.

Animals↗
PubMed2004

Human papillomavirus type specific DNA and RNA persistence--implications for cervical disease progression and monitoring.

In 2000, we monitored the course and persistence of human papillomavirus (HPV) infection in 54 women who were HPV positive and free of any cytological disease using HPV-DNA genotyping with a linear array assay (baseline). The impact of HPV infection on development of cervical cytological abnormality (dyskaryosis) was monitored by repeat HPV genotyping and cytological assessment 2 years later. Detection of mRNA transcripts of known HPV oncogenes E6 and E7 using NASBA methodology and specific molecular beacons for five common HPV types was also performed at both time points. A total of 11/54 (20%) women developed dyskaryosis after 2 years with 31/54 and 23/54 women exhibiting transient and persistent infections respectively, as monitored by DNA genotyping. Women who maintained type-specific persistent HPV infection were significantly more likely to develop dyskaryosis compared to those who exhibited a transient infection (P = 0.001). The presence of HPV mRNA E6/E7 transcripts was less sensitive but more specific for the detection of disease at follow up. Moreover, women who were DNA positive and also positive for mRNA transcripts at baseline were significantly more likely to harbour persistent infection compared to those in whom DNA only was detected at baseline (P = 0.013). This study highlights the importance of detecting persistent type specific HPV infection to identify those women more at risk of developing cervical abnormalities, either by repeated DNA genotyping, or potentially by RNA based techniques that may be more predictive of persistent infection if performed at a single time point.

Adult↗
PubMed2005

Evidence for persistence of adenovirus in the tear film a decade following conjunctivitis.

Chronic papillary conjunctivitis has been described following adenoviral conjunctivitis. It is unknown however, how long adenovirus is able to persist in the tear film and conjunctiva. To determine if adenovirus persists in the ocular surface following adenoviral conjunctivitis, 304 patients with a history of adenovirus conjunctivitis from whom an adenovirus had been isolated 10 years previously were sent a questionnaire regarding persistent or recurrent symptoms and were invited to attend. Patients were examined and samples of tears and conjunctival cells were collected from both eyes using tear film washes, filter paper, and swabs, the latter for virus isolation. Extracted DNA from the ocular samples was amplified using primers for herpes simplex virus (thymidine kinase) and adenovirus (hexon) genes. Adenovirus amplicons were sequenced and compared to original serotype. Thirty patients attended, 19 of whom had persistent papillary conjunctivitis. Evidence of adenovirus DNA was detected in 17 of 30 patients, 15 of whom also had evidence of a chronic papillary conjunctivitis. Adenovirus DNA was significantly associated with papillary conjunctivitis (P = 0.03). Adenovirus amplicons were successfully sequenced from six patients. Four patients harbored type 3 adenovirus, the same serotype with which they were infected originally 10 years previously. Two patients were infected originally with adenovirus serotype 3 but the current serotype was type 4. Infection of the ocular surface with adenovirus may predispose to the development of a persistent or recurrent conjunctivitis, the presence of which, appears to be associated with evidence of long term persistence of adenovirus DNA.

Adenovirus Infections, Human↗
PubMed1995

Effect of persistent mouse hepatitis virus infection on MHC class I expression in murine astrocytes.

Neurotropic strains of mouse hepatitis virus (MHV) have been used extensively for the study of viral pathogenesis in the central nervous system (CNS), serving as models for human neurological diseases such as multiple sclerosis (MS). MHV strains A59 and JHMV both cause acute and chronic encephalomyelitis and demyelination in susceptible strains of mice and rats. In acute disease, CNS damage is most likely the result of lytic infection in neurons and oligodendrocytes, and death can be prevented by the adoptive transfer of Class I-restricted CD8+ T cells. However, in later stages of the disease induced by some MHV strains, virus tends to be restricted to astrocytes in a nonlytic infection, and the immune response appears to contribute to CNS damage. These data lead us to suggest that the astrocyte may play a central role in the neuropathogenesis of MHV infection. Consistent with this possibility, A59 has been reported to induce the expression of Class I molecules of the major histocompatibility complex (MHC) in glial cells following infection in vivo and in vitro. In this communication, we have examined the influence of persistent infection by both A59 and JHMV on MHC Class I expression in primary murine astrocytes. Persistence was characterized by the presence of intracellular viral antigen and mRNA in the absence of detectable infectious virus particles. Under these conditions, JHMV, but not A59, inhibited constitutive expression of the H-2 Kb molecule, with the magnitude of inhibition increasing with postinfection time. A59 was not able to induce Class I during persistence, presumably due to the lack of infectious virus particles. Class I expression was restored by the addition of gamma-interferon (IFN-gamma) to astrocytes persistently infected with either A59 or JHMV. Thus, Class I inhibition is not a permanent consequence of JHMV persistence, and persistence does not interfere with normal signalling pathways for Class I induction.

Animals↗
PubMed2006

Prenatal diagnosis of absent right and persistent left superior vena cava.

OBJECTIVE: Persistence of left superior vena cava (LSVC) is a known variant of the systemic venous return. In the setting of an otherwise structurally normal heart, absence of the right superior vena cava (RSVC) but persistence of the LSVC is rare. METHODS: We describe the prenatal findings of a fetus with absent right and persistent LSVC. RESULTS: A dichorionic diamniotic twin pregnancy was referred to our centre with cardiac disproportion. Twin A had disproportion at four-chamber level, an absent right but persistent LSVC draining to an enlarged coronary sinus and a hypoplastic transverse aortic arch (<2 mm). Postnatal echocardiography of the asymptomatic baby confirmed the prenatal diagnosis, and serial echocardiograms demonstrated general hypoplasia of the aortic arch but no discrete coarctation (CoA). No intervention was required and the baby is thriving aged 10 months. CONCLUSION: Persistence of LSVC is a known variant of the systemic venous return. In the setting of an otherwise structurally normal heart, absence of the right but persistence of LSVC is rare.

Adult↗