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PubMed1976

Uptake and persistence of pesticides in cultured human cells.

The uptake and persistence of 14C-labeled pesticides in cultur-s of human embryonic lung diploid cells were studied. Chlordimeform, DDT, parathion, aldrin and dieldrin were selected as test compounds. Results obtained from these experiments divided the chemical into two groups. The first group consisted of three chemical DDT, aldrin and dieldrin which are generally classified as persistent insecticides while the second group was composed of chlordimeform and parathion, generally considered to be non-persistent insecticides. The rate of initial cellular incorporation of first group was approximately 20 to 70 times greater than the non-persistent insecticides. During the course of an incubation, the amounts of pesticide taken up by the cells decreased gradually.

Aldrin↗

PubMed1992

Persistent measles virus infection enhances major histocompatibility complex class I expression and immunogenicity of murine neuroblastoma cells.

The effect of persistent measles virus infection on the expression of major histocompatibility complex (MHC) class I antigens was studied. Mouse neuroblastoma cells C1300, clone NS20Y, were persistently infected with the Edmonston strain of measles virus. The persistently infected cell line, NS20Y/MS, expressed augmented levels of both H-2Kk and H-2Dd MHC class I glycoproteins. Activation of two interferon(IFN)-induced enzymes, known to be part of the IFN system: (2'-5')oligoadenylate synthetase and double-stranded-RNA-activated protein kinase, was detected. Measles-virus-infected cells elicited cytotoxic T lymphocytes that recognized and lysed virus-infected and uninfected neuroblastoma cells in an H-2-restricted fashion. Furthermore, immunization of mice with persistently infected cells conferred resistance to tumor growth after challenge with the highly malignant NS20Y cells. The rationale for using measles virus for immunotherapy is that most patients develop lifelong immunity after recovery or vaccination from this infection. Patients developing cancer are likely to have memory cells. A secondary response induced by measles-virus-infected cells may therefore induce an efficient immune response against non-infected tumour cells.

2',5'-Oligoadenylate Synthetase↗

PubMed1984

Coxsackievirus B3 persistence and myocarditis in NFR nu/nu and +/nu mice.

NFR nude (nu/nu) and euthymic (+/nu) littermates were infected with coxsackievirus B3 (CBV-3) and assayed for virus persistence in the heart, pancreas and spleen, for development of myocarditis and for antibody production. The virus grew to higher titer and persisted longer in hearts of nu/nu mice. In both types of mice there was comparable myocarditis with a mononuclear cell inflammatory response, and there was some evidence of chronic lesions for up to 21 days in +/nu and 28 days in nu/nu mice. Antibody of the IgM class was present at 7 days in both strains of mice. Thereafter, +/nu mice produced high titers of virus-specific IgG antibody, while nu/nu mice produced little or no viral IgG antibody. The persistence of virus for up to 28 days in NFR nude mice is longer than has been reported previously, and offers an opportunity for further study of the role of T-cells in virus persistence and myocarditis.

Animals↗

PubMed1995

Persistent catalepsy associated with severe dyskinesias in rats treated with chronic injections of haloperidol decanoate.

Patients who develop persistent parkinsonism while on chronic neuroleptic therapy may be predisposed towards the development of tardive dyskinesia (TD). We investigated this issue in an animal model of TD by examining the association between catalepsy and the syndrome of neuroleptic-induced vacuous chewing movements (VCMs). VCMs were measured every 3 weeks for 33 weeks while rats received injections of haloperidol decanoate. Catalepsy was measured after the second through the seventh injections of the depot neuroleptic. There were no correlations between the severity of catalepsy scores after the second or third injections of haloperidol and the severity of the overall VCM syndrome. However, the severity of the catalepsy score following the third through seventh injections of haloperidol strongly correlated with the concurrent number of VCMs. Persistent high catalepsy scores across the six catalepsy rating sessions were strongly associated with the development of persistent severe VCMs. These findings suggest that, to the extent that persistent parkinsonian signs in humans are associated with a propensity towards the development of TD, the VCM syndrome in rats is at least a partially faithful animal model of this relationship.

Animals↗

PubMedDate not supplied

Vitreous haemorrhage and other ocular complications of a persistent hyaloid artery.

PURPOSE: To report ocular complications of a persistent hyaloid artery. METHODS: We studied eight patients with persistent hyaloid artery. RESULTS: Seven patients showed strabismus and very low visual acuity (< or = 0.12) of one eye. Despite correction of refractive errors, cataract surgery and occlusion therapy for amblyopia, visual acuity had not improved in these cases. Four patients showed nystagmus. Four had progression of unilateral cataract. In two cases, a 24-year-old women and a 4-months-old boy, a vitreous haemorrhage had occurred due to rupture of a hyaloid artery, in the woman's case probably due to a spontaneous posterior vitreous detachment. CONCLUSION: A persistent hyaloid artery may be associated with strabismus, cataract, amblyopia and nystagmus. Despite amblyopia treatment, the prognosis of visual acuity of the involved eye is unfavourable. A persistent hyaloid artery may cause vitreous haemorrhage.

Adolescent↗

PubMed2002

Persistence and vulnerability: retaining biodiversity in the landscape and in protected areas.

An objective of biodiversity conservation activities is to minimize the exposure of biodiversity features to threatening processes and to ensure, as far as possible, that biodiversity persists in the landscape. We discuss how issues of vulnerability and persistence can and should be addressed at all stages of the conservation planning and implementation process. Procedures for estimating the likelihood of persistence and for measuring degrees of vulnerability at different spatial and temporal scales using subjective assessments, rules of thumb and analytical and simulation models are reviewed. The application of information on vulnerability and persistence to conservation planning and management is discussed under the headings of natural dynamics, replication of protection, levels of representation, source and sink population structures, refuges and critical resources, reserve design, habitat fragmentation and levels of management.

Animals↗

PubMedDate not supplied

The role of excitatory amino acid receptors and intracellular messengers in persistent nociception after tissue injury in rats.

Increased pain sensitivity (hyperalgesia) and persistent nociception following peripheral tissue injury depends both on an increase in the sensitivity of primary afferent nociceptors at the site of injury (peripheral sensitization), and on an increase in the excitability of neurons in the central nervous system (central sensitization). We will review evidence that central sensitization, and the persistent nociception it leads to, are dependent on an action of glutamate and aspartate at excitatory amino acid (EAA) receptors. Additional evidence will be presented implicating a role of various intracellular second messengers that are coupled to EAA receptors (nitric oxide, arachidonic acid, and protein kinase C) to central sensitization and persistent nociception following tissue injury. Finally, we will examine the evidence for a contribution of molecular events, including noxious stimulus-induced expression of immediate-early genes such as c-fos to persistent nociception.

Afferent Pathways↗

PubMed1997

Is the persistence of isolated GH deficiency in adulthood predicted by anatomical hypothalamic-pituitary alterations?

The aim of this study was to verify the persistence in adulthood of GH deficiency diagnosed in childhood and treated with hGH in childhood and to study whether anatomical hypothalamic-pituitary alterations evaluated by magnetic resonance (MR) imaging could predict it. To this goal, in six GHD adults (3 males and 3 females aged 17.2-24.5 yr, BMI 21.8 +/- 1.3), we studied anterior pituitary hormone response to GHRH (1 microgram/kg iv)+pyridostigmine (120 mg po)+ GnRH (100 micrograms iv) +TRH (400 micrograms iv)+hCRH (100 micrograms iv) as well as brain MR imaging. In childhood, the diagnosis of severe isolated GHD had been done based on auxological findings as well as on GH response < 7 micrograms/L after two classical provocative stimuli. In the present study, hormonal responses showed the persistence of severe isolated GHD in 4 out of 6 patients (peak, mean +/- SEM: 3.8 +/- 0.6, range 2.6-4.8 micrograms/L). In these patients, IGF-I levels were found low or low-normal. In other 2 patients, a clear GH response to stimulation (peak: 51.3 and 43.0 micrograms/L, respectively) together with normal IGF-I levels were found. No other anterior pituitary hormone deficiency was present in all subjects. MR imaging showed pituitary hypoplasia in all patients with persistent GHD; in 2 out of them, pituitary stalk interruption and ectopic neurohypophysis was also present. On the other hand, MR imaging showed normal hypothalamo-pituitary morphology in the 2 subjects with normal somatotrope response. In conclusion, our present data indicate that testing with a potent stimulus such as GHRH+pyridostigmine is a reliable method to assess the persistence of GH deficiency which associates with anatomical hypothalamic-pituitary alterations at the MR imaging. Patients with transient GH deficiency in childhood and normal pituitary GH reserve in adulthood have normal hypothalamic-pituitary MR imaging.

Adolescent↗

PubMed1999

[Early diagnosis and reoperation in persistent primary hyperparathyroidism].

INTRODUCTION: The persistence rate of primary hyperparathyroidism after cervical exploration was estimated and early diagnosis and reoperation were evaluated in a prospective study. METHODS: Between 1 August 1987 and 31 October 1998, 370 patients underwent surgery. The postoperative course is known in 94.6 % of these patients (follow-up 1 month-10 years, median 24 months). RESULTS: Cervical exploration was successful in 97.5 % (n = 353) of the 361 patients with the first manifestation of primary hyperparathyroidism and in all patients with recurrence or persistence of the disease after initial operation elsewhere. In persistent primary hyperparathyroidism serum calcium levels remained elevated 4 days after surgery (n = 9, 2.5 %). Localization studies, preferably with (99m)Tc-MIBI-scintigraphy were attempted during the first postoperative week and could be performed in 4 patients. Four patients wished the procedure to be performed later. CONCLUSION: Within one week after the initial intervention the diagnosis of persistent primary hyperparathyroidism can be established and localization studies as well as cervical reexploration can be carried out. An interval of 3 months from the initial operation to reexploration of the parathyroid area is recommended if the reexploration is impossible within one week. Mediastinal reoperations or surgical interventions in the neck sparing the perithyroid area may be carried out without consideration of specific intervals.

Adenoma↗

PubMed2004

Persistence of candiduria in ICU catheterized patients is not linked to adherence and proteolytic activities of Candida strains.

OBJECTIVE: In this study, the patients who developed asymptomatic candiduria in the intensive care unit were followed prospectively for the persistence of candiduria after the replacement of indwelling urethral catheter and the correlation between persistence and virulence factors (proteinase enzyme activity and epithelial adhesion) was assessed. DESIGN: Prospective study. SETTING: Intensive care unit and mycology laboratory at a university hospital. PATIENTS: Thirty-four patients with asymptomatic candiduria were included in the study. RESULTS: Candiduria persisted in 19 of 34 patients(56%; group 1) and cleared in 15 of 34 patients(44%; group 2) after urinary catheters were changed. When the virulence factors (epithelial adhesion and proteinase activity) and distribution of Candida spp. were compared between two groups, no statistically significant correlation was found. CONCLUSION: The host immune response might be more important than virulence factors of Candida spp. for persistence of candiduria.

Adolescent↗

PubMed2001

Persistent site-specific defects after reconstructive pelvic surgery.

Our objective was to determine the persistence rates of site-specific defects after reconstructive pelvic surgery. We conducted a retrospective analysis of the post-operative outcome for 77 patients with pelvic support defects. Forty-five patients in the abdominal group underwent a Burch procedure, paravaginal repair and sacral colpopexy when indicated; 32 patients in the vaginal group had a sacrospinous vault fixation with or without colporrhaphy. A chi2 test, Wilcoxon's two-sample test. Wilcoxon's signed-rank test and multivariate logistic regression model were used for data analysis. The two groups were similar in age, weight, parity and menopausal status. There was significant improvement of all defects except in the vaginal group, which showed a higher rate of persistent paravaginal defects (68.7 vs. 13.3%, P = 0.001). After adjusting for potential confounders, there was no difference in the rates of apical and anterior wall defects between the two groups. The odds ratio for persistent paravaginal defects in the vaginal group was 8.9 (95% CI: 2.3-34). The choice of surgical procedure is the most important factor determining the rate of persistent pelvic support defects. Lateral wall defects must be addressed at the time of reconstructive surgery.

Adult↗

PubMed2004

Persistent renal cortical scintigram defects in children 2 years after urinary tract infection.

BACKGROUND: Renal cortical scintigraphic studies challenge the role of vesicoureteric reflux in renal scar development, emphasizing instead the part played by acute pyelonephritis. OBJECTIVE: To determine the prevalence of renal cortical defects in a child cohort 2 years after the child's first diagnosed urinary tract infection and to analyze the relationship of these defects with acute illness variables, primary vesicoureteric reflux and recurrent infections. MATERIALS AND METHODS: In a prospective cohort study, 193 children younger than 5 years with their first proven urinary tract infection underwent renal sonography, voiding cystourethrogram, and renal cortical scintigraphy within 15 days of diagnosis. Two years later, 150 of the 193 children, or 77.7%, had a further renal cortical scintigram, including 75, or 86.2%, of the 87 children who had acute scintigraphic defects. The relationship of cortical defects to age, gender, pre-treatment symptom duration, hospitalization, presence and grade of vesicoureteric reflux, and recurrent urinary tract infections was evaluated. RESULTS: Overall, 20 of the 150 (13.3%; 95% confidence interval (CI) 8.3, 19.8) children had persistent defects 2 years after infection. This included 20 of 75 (26.7%; 95% CI 17.1, 38.1) with initially abnormal scintigrams. No new defects were detected. Although acute defects were more common in the young, those with persistent defects were older (median ages 16.4 vs. 6.8 months, P=0.004) than those with transient abnormalities. After adjustment for age, persistent defects were no longer associated with gender and were not predicted by acute illness variables, primary vesicoureteric reflux or recurrent infections. CONCLUSIONS: Renal cortical scintigraphic defects persisted in approximately one-quarter of young children after their first proven urinary tract infection. The associated clinical features, however, failed to predict scar formation. It is possible that some of the scintigraphic defects preceded the infection by arising from either previously undiagnosed acute pyelonephritis or from underlying congenital dysplasia. The etiology of scars may be best addressed by determining whether prevention of urinary tract infections from birth avoids post-natal scar acquisition or extension.

Chi-Square Distribution↗

PubMed2007

Contrast-enhanced magnetic resonance angiography of persistent fifth aortic arch in children.

BACKGROUND: Cine angiography and echocardiography have been utilized to diagnose congenital aortic arch anomalies. However, the visualization of great vessels by echocardiography is limited, while cine angiography requires cardiac catheterization with ionizing radiation. Contrast-enhanced magnetic resonance angiography (MRA) is a noninvasive modality suitable for visualization of congenital aortic arch anomalies. OBJECTIVE: To evaluate the utility of contrast-enhanced MRA in the diagnosis of persistent fifth aortic arch, a rare congenital aortic arch anomaly, and to compare the diagnostic accuracy of MRA with that of echocardiography and cine angiography. MATERIALS AND METHODS: In four pediatric patients, contrast-enhanced MRA studies were performed for diagnosing persistent fifth aortic arch. The findings of MRA were compared with echocardiographic findings and confirmed by cine angiography and operation. RESULTS: Transthoracic surface echocardiography noted an aberrant vessel arising from the ascending aorta in two of four patients; the etiology of this vessel was uncertain. In the other two patients a diagnosis of coarctation was made. Of the four patients, only one was diagnosed with interruption of the aortic arch. Contrast-enhanced MRA clarified uncertain echocardiographic findings, enabling the correct diagnosis of persistent fifth aortic arch with fourth aortic arch interruption in all four patients. CONCLUSION: Contrast-enhanced MRA is a safe, accurate, and fast imaging technique for the evaluation of persistent fifth aortic arch and may obviate the need for conventional cine angiography. Cardiac catheterization may be reserved for some types of complicated congenital heart disease and for obtaining hemodynamic information.

Aorta, Thoracic↗

PubMed2002

Normocalcemia and persistent elevated serum concentrations of 1-84 parathyroid hormone after operation for sporadic parathyroid adenoma: evidence of increased morbidity from cardiovascular disease.

Elevated serum concentrations of 1-84 parathyroid hormone (PTH) after operation for sporadic parathyroid adenoma have been reported in previous studies, years after operation for primary hyperparathyroidism (pHPT). The cause and significance of this finding have not been elucidated. Primary hyperparathyroidism was diagnosed in 195 patients from January 1987 to December 1998. Operation for pHPT was performed in 124 patients. To evaluate long-term effects of elevated serum 1-84 PTH, biochemical variables and pre- and postoperative diseases were investigated from hospital case records. Of the 124 patients operated on, 103 had a solitary adenoma. Among these patients, 60 had normal serum concentrations of 1-84 PTH and calcium postoperatively, 38 patients had follow-up for more than 12 months (range 12-207 months-group A). Persistent elevated serum concentrations of 1-84 PTH and normocalcemia were found in 23 patients. Fourteen patients had follow-up for more than 12 months (range 15-76 months-group B). Two patients had persistent pHPT, and 18 were normocalcemic, but in this retrospective study data on serum 1-84 PTH were not available. No significant differences were found between groups A and B at the time of diagnosis concerning clinical characteristics. More that 12 months after operation for pHPT, the patients in group B, with persistent elevated serum concentrations of 1-84 PTH, had a significantly (c2 = 11, p = 0.005, and power of test 0.66) higher frequency of cardiovascular diseases from ischemic heart disease and hypertension. Persistent elevated serum concentrations of 1-84 PTH after operation for sporadic parathyroid adenoma may be associated with development of cardiovascular disease. This group of patients therefore needs lifelong control and, possibly, medical intervention.

Adenoma↗

PubMed1999

Persistent inward currents in cultured Retzius cells of the medicinal leech.

Current-clamp studies of cultured leech Retzius cells revealed inward rectification in the form of slow voltage sags in response to membrane hyperpolarization. Sag responses were eliminated in Na(+)-free saline and blocked by Cs+, but not Ba2+. Voltage clamp experiments revealed a Cs(+)-sensitive inward current activated by hyperpolarization negative to -70 mV. Cs+ decreased the frequency of spontaneous impulses in Retzius cells of intact ganglia. Plateau potentials were evoked in Retzius cells following block of Ca2+ influx with Ni2+ and suppression of K+ currents with internal tetraethylammonium. Plateau potentials continued to be expressed with Li+ as the charge carrier, but were eliminated when Na+ was replaced with N-methyl-D-glucamine. A persistent Na+ current with similar pharmacology that activated positive to -40 mV and reached its peak amplitude near -5 mV was identified in voltage-clamp experiments. Inactivation of the persistent Na+ current was slow and incomplete. The current was revealed by slow voltage ramps and persisted for the duration of 5-s voltage steps. Persistent Na+ current may underlie Na(+)-dependent bursting recorded in neurons of intact ganglia exposed to Ca2(+)-channel blockers.

Animals↗

PubMed2002

The character of variant persistent müllerian-duct structures.

To categorize variant persistent müllerian-duct derivatives (MDD) in males and determine their related clinical presentations for further management, five male patients with retained MDDs from abnormal müllerian remnants were studied. They comprised one patient with persistent müllerian-duct syndrome, one with transverse testicular ectopia, two with mixed gonadal dysgenesis, and one with a müllerian-duct cyst. Removal of persistent müllerian-duct structures and genitoplasty were done in selected patients. Categorization of patients with persistent MDDs permits further understanding of the pathogenesis and facilitates the choice of treatment.

Adolescent↗

PubMed2005

Persistent rectal prolapse in children: sclerotherapy and surgical management.

Persistent rectal prolapse is an uncommon but distressing condition in children. Significant controversy exists regarding its surgical management. The aim of this study was to identify a successful management strategy for persistent rectal prolapse in the paediatric population. Records of all children with rectal prolapse treated surgically at Birmingham Children's Hospital between 1995 and 2003 were retrospectively reviewed. Demographic data, clinical presentation, investigations, treatment modality, complications, and outcome were recorded. Inclusion criteria for the study were failure of conservative management leading to operative treatment. An exclusion criterion was cystic fibrosis. A total of 24 patients with persistent rectal prolapse were identified. Two children with cystic fibrosis were excluded from the analysis. Children below the age of 5 years, group I (n=17), were successfully managed by submucous hypertonic saline injections. Eighty-three percent (14/17) were cured by injection sclerotherapy in this group, 12/14 (71%) requiring one injection and 2/14 requiring a second injection. In the three (17.6%) children in group I in whom sclerotherapy failed, cow's milk protein (CMP) allergy was identified as the causative factor. Children older than 5, group II (n=5), either had behavioural problems (n=3) or were autistic (n=2). This group of children with adult-type, full-thickness rectal prolapse were found to be refractory to initial attempts of injection sclerotherapy. All five children were successfully managed with surgical correction. We conclude that rectal submucous hypertonic saline injections are highly effective for managing early-onset idiopathic childhood rectal prolapse. CMP allergy should be considered in young children with recurrent rectal prolapse. We recommend early definitive corrective surgery in older children with persistent rectal prolapse, as they do not respond to conservative measures or injection sclerotherapy.

Child, Preschool↗

PubMed2001

A case of persistent endometriosis after total hysterectomy with both salpingo-oophorectomy managed by radiation therapy.

Persistent endometriosis after total hysterectomy and both salpingo-oophorectomy (TH with BSO) is a rare condition and the etiology is uncertain. The exact incidence of persistent endometriosis after definitive surgery is not known. In addition, the treatment of persistent endometriosis after complete surgical excision is controversial. We report a case of persistent endometriosis with vaginal and sigmoid-colonic invasion after TH with BSO. The lesions were not responsive to hormonal therapy. The patient was managed successfully by therapeutic pelvic radiation.

Adult↗