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PubMed1997

Megaureter in childhood: conservative or surgical management?

Antenatal and incidentally diagnosed megaureters can be safely treated conservatively after careful work up by combined imaging technics. Serial and repeated imaging are non the less usually necessary to confirm the diagnosis. This aspect could be fastidious and expensive. In case of symptoms, breakthrough infections or loss of kidney function, surgical treatment should be considered and good results can be expected. Refluxing megaureter has to be considered as high grade reflux and surgical approach is more often suggested. The authors have reviewed the experience of 139 patients with megaureters treated in the last decade to illustrate those facts.

Child↗
PubMed2000

Helicobacter pylori infection influences nocturnal gastric acid breakthrough.

BACKGROUND: Nocturnal gastric acid breakthrough is defined as night-time periods when gastrin pH falls below 4.0 for greater than 1h during administration of a proton pump inhibitor. This phenomenon is a serious problem for patients who require strict control of their gastric acid secretions. AIM: To investigate the prevalence of nocturnal gastric acid breakthrough in Japanese subjects during administration of rabeprazole, and to clarify the relationship between Helicobacter pylori infection and nocturnal gastric acid breakthrough. METHODS: Thirty-one normal male volunteers were examined by ambulatory 24 h gastric pH monitoring four times: without medication, after a morning or an evening dose of 20 mg rabeprazole, and after administration of an H2-receptor antagonist at bedtime, in addition to the morning dose of rabeprazole. H. pylori infection was determined by the 13C-urea breath test and an assay for serum anti-H. pylori antibody. RESULT: Nocturnal gastric acid breakthrough was observed in 12 patients (39%) after the morning dose of 20 mg rabeprazole. In all cases, nocturnal gastric acid breakthrough was inhibited completely by administration of the H2-receptor antagonist at bedtime. Only one patient with nocturnal gastric acid breakthrough had H. pylori infection. CONCLUSION: The absence of H. pylori infection appears to be closely related to the occurrence of nocturnal gastric acid breakthrough during dosing with a proton pump inhibitor.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

HBV genotypic resistance to lamivudine in kidney recipients and hemodialyzed patients.

BACKGROUND: Lamivudine is a potent inhibitor of human immunodeficiency virus reverse transcriptase and hepatitis B virus (HBV) DNA polymerase. Its overall efficiency is clearly hampered by relapse at discontinuation and by risk of genotypic resistance. We describe herein the first cases of HBV resistance to lamivudine in kidney recipients and hemodialyzed patients. METHODS: We analyzed 26 HBV-infected kidney recipients and five hemodialyzed patients treated with lamivudine who became serum HBV DNA-negative (by Digene test). The biological and virological follow-up identified breakthrough as defined by the reappearance of serum HBV DNA. In two cases of breakthrough, HBV DNA was amplified and sequenced through the polymerase domain, including the YMDD motif, before the beginning of treatment and at time of breakthrough to determine genotypic mutations. RESULTS: Ten breakthroughs (reappearance of serum HBV DNA) were observed after a median follow-up of 11 months in eight kidney recipients and two hemodialyzed patients after a median duration of treatment of 16.5 (from 4 to 31) months of treatment. Previous HBe/anti-HBe seroconversion was not observed in the patients who escaped. In two kidney recipients, the comparison of HBV-DNA sequences before the treatment and after the breakthrough identified in one case a mutation of the highly conserved YMDD motif (YVDD), whereas in the second case, no genotypic mutation was observed in the sequenced region. CONCLUSION: We report the first cases of HBV genotypic resistance to lamivudine in kidney recipients and hemodialysis patients. Genotypic resistance is observed after 4-31 months of therapy. The YMDD mutation does not account for all cases of virological escape.

Adult↗
PubMed1987

[Clinical polymorphism of circumscribed intracerebral hematomas].

Using clinical and a series of additional methods of examination, including computer-aided tomography, the authors studied 46 cases of limited (without breakthrough of blood into the CSF) intracerebral hematomas (LIH) which constituted 22% of the total number of the examined patients with brain hemorrhages. It has been established that in the majority of the cases of LIH (87%) the diagnosis of the stroke nature was difficult to make without computer-aided tomography. It was shown that the characteristics of the clinical picture and course of LIH were determined by the absence of breakthrough of blood into the CSF system, a relatively small size of hematoma, a mild degree of dislocational manifestations and their slow evolution. Three main variants of the clinical course of LIH were identified. The course of the disorder was usually favourable; the lethal outcome occurred in only 15.2% of the cases. The authors draw attention to the expediency of conducting computerized tomography over time and to the necessity of taking into account the status of the homeostasis system in the treatment of such patients.

Aged↗
PubMed2005

Risk factors and outcome for nosocomial breakthrough candidaemia.

OBJECTIVES: To describe all cases of nosocomial candidaemia that occurred in patients in use of anti-fungals. METHODS: Retrospective cohort study (1995-2003). Breakthrough candidaemia was defined as the occurrence of candidaemia in a patient receiving at least 3 days of systemic anti-fungal therapy. Patients with breakthrough candidaemia were compared to patients with non-breakthrough candidaemia. RESULTS: During the period of study, 20 patients had breakthrough candidaemia, and 40% of them had cancer. While most of these episodes occurred with amphotericin B, some patients received low-dose regimens of fluconazole or ketoconazole in association with ranitidine. Non-Candida albicans species caused 75% of these infections, mainly Candida parapsilosis (30%). When compared to controls (n=171), the breakthrough group had more frequently mucositis, longer stay in the intensive care unit, and longer periods of hyperalimentation, mechanical ventilation, urinary catheter and broad-spectrum antibiotics. Candida isolation from sites other than blood occurred more frequently in the breakthrough group. Mortality rate and Candida species distribution were similar among groups. CONCLUSIONS: C. parapsilosis was the main aetiology of breakthrough candidaemia. Common risk factors included mucositis, isolation of Candida from sites other than blood, use of broad-spectrum antibiotics, and invasive medical procedures. No difference in the mortality rate was observed.

Adolescent↗
PubMed2001

Breakthrough fungaemia in neonates and infants caused by Candida albicans and Candida parapsilosis susceptible to fluconazole in vitro.

Breakthrough fungaemias due to Candida albicans and Candida parapsilosis appearing during fluconazole therapy in neonates and infants were assessed for risk factors and outcome. Forty fungaemias occurred during therapy with fluconazole within a 12 year national survey and were compared with 161 cases of non-breakthrough paediatric fungaemias. The agar disc diffusion test method was used for antifungal susceptibility testing and the Vitek system for species identification. Univariate and multivariate analysis for risk factors for breakthrough fungaemia were carried out. All the fungaemias were a result of strains susceptible to fluconazole at 0.25-4 mg/L in vitro [C. albicans (85%) and C. parapsilosis (15%)]. The mean number of positive blood cultures per episode was 2.2. Sixteen children had 'early' breakthrough fungaemias (within 4-5 days) and 24 fungaemias appeared on day 6 and later. Mean fluconazole MICs in the 'early' group were 1.2, and 2.8 mg/L in the 'late' group (P < 0.03, t-test). However, no difference was observed in the average dose of fluconazole used in the two groups. Neonatal age, total parenteral nutrition, very low birth weight, before surgery, central or umbilical venous catheterization and artificial ventilation were all significantly related to breakthrough fungaemia in univariate analysis but only central or umbilical venous catheterization were significant in multivariate analysis. The outcome of breakthrough fungaemia was better overall and attributable mortalities in non-breakthrough fungaemia was significantly higher in comparison with breakthrough fungaemia.

Antifungal Agents↗
PubMed2025

Risk Factors for Breakthrough Acute SARS-CoV-2 Infections in Fully Vaccinated Individuals: A Case-Control Study Nested in a Prospective Cohort in Medelln, Colombia.

To effectively curb coronavirus disease 2019 (COVID-19), it is essential to understand the risk factors for breakthrough acute infections of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) despite vaccination. We conducted a case-control study to assess risk factors for acute SARS-CoV-2 infections requiring hospitalization in vaccinated individuals. The study included 50 vaccinated patients who experienced breakthrough infections requiring hospitalization (inpatient cohort) and 250 control participants from the outpatient cohort of the "Genomic Surveillance and Immune Response Monitoring for COVID-19 in the Metropolitan Area of the Aburr&#xe1; Valley, Medell&#xed;n-Colombia". Demographic characteristics, vaccination status, and immune responses were compared between cases and controls using multivariate logistic regression. Advanced age (&#x2265;&#x2009;65 years), male sex, high-risk comorbidities, and immunosuppression were associated with an increased risk of breakthrough SARS-CoV-2 infections despite prior vaccination. In contrast, receipt of a booster dose and the presence of neutralizing antibodies were linked to a reduced risk of such infections. This study identifies key risk and protective factors associated with breakthrough SARS-CoV-2 infections. Derived from a high-middle-income setting, these real-world findings provide valuable insights to guide targeted vaccination strategies for vulnerable populations.

Humans↗
PubMed1989

Normal perfusion pressure breakthrough complicating surgery for the vein of Galen malformation: report of three cases.

Three cases are described of infants who developed malignant brain swelling (and in one case hemorrhage) after surgery for vein of Galen malformations. The cause for the brain swelling was felt to be due to hyperperfusion, or the "normal perfusion pressure breakthrough" syndrome. Although well-described for cerebral parenchymal arteriovenous malformations, cases of this complication occurring in vein of Galen malformations have not previously been reported. It is concluded from these cases that infants with large arteriovenous shunts, as attested by cardiac failure and cerebral atrophy, have an increased risk of developing this complication.

Brain Edema↗
PubMed2006

Intrauterine shunt for obstructive hydrocephalus--still not ready.

OBJECTIVE: To determine the safety and efficacy of ventriculoamniotic shunt placement through a hysterotomy in the second trimester of pregnancy as treatment for isolated obstructive hydrocephalus. METHODS: Between 1999 and 2003, four pregnancies with isolated fetal obstructive hydrocephalus in the second trimester were treated at Vanderbilt University Medical Center. Preoperatively, all fetuses underwent serial ultrasonographic examinations and an ultrafast magnetic resonance imaging to confirm isolated aqueductal stenosis. A normal fetal karyotype and negative polymerase chain reaction or culture of the amniotic fluid for cytomegalovirus and toxoplasmosis were obtained. Serial enlargement of the lateral ventricles >1.5 mm/week and fetal macrocephaly were documented. Using epidural and GETA, a standard ultrasmall ventricular catheter and valve were inserted via a hysterotomy. The distal catheter, rather than being inserted into the fetal peritoneum, exited between the fetal scapulae. Patients were discharged home from the hospital, and the remainder of their prenatal care was provided by their local obstetrician. After delivery, the distal drain was converted to a ventriculoperitoneal shunt. RESULTS: Cases were performed at 23 6/7, 25 5/7, 26 4/7, and 26 5/7 weeks. Shunts performed well during pregnancy, and were intact at delivery. Deliveries occurred at 34 1/7, 27 1/7, 28, and 32 4/7 weeks. Birthweights were 2,010, 907, 1,200, and 2,220 g. All Apgar scores were normal. Case 1 developed a neonatal shunt infection, and is now developmentally delayed, with swallowing dysfunction, hearing deficits and a poor pupillary response. Case 2 developed neonatal sepsis and is now developmentally delayed. Case 3 delivered preterm due to chorioamnionitis, and neonatal death occurred from sepsis. Case 4 is developmentally delayed. CONCLUSIONS: Ventriculoamniotic shunt can be placed through a hysterotomy, overcoming many of the technical difficulties of earlier percutaneous shunts. However, recent developments in fetal imaging and molecular genetics have not improved case selection. Unless new breakthroughs occur, fetal shunting cannot reasonably be expected to improve perinatal outcome.

Cerebrospinal Fluid Shunts↗
PubMed1996

Development of anti-interferon antibodies and breakthrough hepatitis during treatment for HCV infection in haemophiliacs.

The development of anti-interferon antibodies may lead to treatment failure during interferon therapy. We have studied the development of such antibodies in a group of 39 haemophiliacs receiving interferon-alpha 2a for chronic hepatitis C virus (HCV) infection. Anti-interferon antibodies developed in five (13%) patients and were associated with "breakthrough hepatitis' in three cases. There was an association between the development of anti-interferon antibodies and infection with HCV genotype 3a (P = 0.01). This study suggests that the development of anti-interferon antibodies may lead to treatment failure in a proportion of haemophiliacs with HCV infection. The association with genotype 3a has not previously been reported. Monitoring for the development of breakthrough hepatitis due to anti-interferon antibodies may provide the opportunity to develop strategies to overcome their effects.

Adolescent↗
PubMed2006

Applied tracer tests in fractured rock: Can we predict natural gradient solute transport more accurately than fracture and matrix parameters?

Applied tracer tests provide a means to estimate aquifer parameters in fractured rock. The traditional approach to analysing these tests has been using a single fracture model to find the parameter values that generate the best fit to the measured breakthrough curve. In many cases, the ultimate aim is to predict solute transport under the natural gradient. Usually, no confidence limits are placed on parameter values and the impact of parameter errors on predictions of solute transport is not discussed. The assumption inherent in this approach is that the parameters determined under forced conditions will enable prediction of solute transport under the natural gradient. This paper considers the parameter and prediction uncertainty that might arise from analysis of breakthrough curves obtained from forced gradient applied tracer tests. By adding noise to an exact solution for transport in a single fracture in a porous matrix we create multiple realisations of an initial breakthrough curve. A least squares fitting routine is used to obtain a fit to each realisation, yielding a range of parameter values rather than a single set of absolute values. The suite of parameters is then used to make predictions of solute transport under lower hydraulic gradients and the uncertainty of estimated parameters and subsequent predictions of solute transport is compared. The results of this study show that predictions of breakthrough curve characteristics (first inflection point time, peak arrival time and peak concentration) for groundwater flow speeds with orders of magnitude smaller than that at which a test is conducted can sometimes be determined even more accurately than the fracture and matrix parameters.

Geological Phenomena↗
PubMed2002

Nucleoside analogues for chronic hepatitis B: antiviral efficacy and viral resistance.

Nucleoside analogues have been recently introduced in the management of chronic hepatitis B virus (HBV) infection. They mainly act by inhibition of HBV polymerase activity resulting in decrease of viral replication. They are administered orally, and most of them have an excellent tolerance and safety profile. Lamivudine is the only nucleoside analogue licensed for chronic hepatitis B. It has potent activity against HBV, and a 12-month course achieves clearance of hepatitis B e antigen (HBeAg) in 20-30% of HBeAg-positive patients and both biochemical and virological remission in more than 65-70% of HBeAg-negative chronic hepatitis B patients. Famciclovir and ganciclovir are less effective, whereas other nucleoside or nucleotide analogues, such as adefovir, entecavir, and emtricitabine, are currently under evaluation. Prolonged effective antiviral therapy is required for eradication of chronic HBV infection, but long-term treatment with nucleoside analogues has been found to be associated with progressively increasing rates of viral resistance because of emergence of resistant HBV mutant strains. Virological breakthroughs usually develop after the first 6 months of lamivudine monotherapy, and their rate ranges between 15% and 30% at 12 months and exceeds 50% after 3 yr of therapy. Resistant HBV mutant strains harbor point mutations in the HBV polymerase gene and predominantly in the well-conserved YMDD motif. Although resistant HBV strains may have impaired replication capacity compared with the wild HBV, their clinical significance has not been completely clarified yet. No significant biochemical or clinical event may develop in some cases, whereas severe biochemical breakthroughs with or without deterioration of liver function may develop in others. To date, there is no proven effective therapy for the resistant HBV mutant strains, although adefovir and entecavir seem to be interesting candidates.

2-Aminopurine↗
PubMed2006

Discovery of invisible extra fronts in single-component frontal analysis in liquid chromatography.

Frontal analysis (FA) is often used in the "staircase mode", in which the solute concentration in the eluent increases stepwise. We demonstrate here in the single-component case, that all eluted breakthrough curves (fronts) for the second and subsequent steps consist solely of displaced plateau molecules. The newly introduced molecules (i.e., the introduced mass) instead elute later, in a breakthrough front hidden from detection, i.e., the mass front. These effects were studied using experimentally verified numerical calculations, the mass fronts being visualized using an enantiomer pair in an achiral separation system. Notably, the mass front displays no self-sharpening effects, even under strongly nonlinear conditions. Instead, the front is sigmoidal in shape.

Adsorption↗
PubMed2001

Oscillatory electroosmosis-enhanced intra/inter-particle liquid transport and its primary applications in the preparative electrochromatography of proteins.

The concept of generating an oscillatory electroosmotic flux inside the porous particle to enhance the intra-particle mass transport was presented and a new kind of electrochromatography carried out in a five-compartment electrolyzer were developed. The adsorbent was packed in the central compartment, while the neighboring compartments were used as the elution compartments and the electrode compartments, respectively. Chromatographic separations of human serum albumin on Blue Sepharose Fast Flow, bovine serum albumin (BSA) on DEAE-Sepharose Fast Flow, and BSA on hydroxyapatite were carried out, respectively. The adsorption isotherms were shown to be independent of electric field, while the increase in the electric field strength resulted in a linear increase in the magnitude of electroosmotic flux and the improvement of the breakthrough behavior in all cases. The experiment results have demonstrated the effectiveness of the oscillatory electroosmosis in enhancing intra- and inter-particle mass transport and its high potential to large-scale chromatography.

Adsorption↗
PubMedDate not supplied

Evolution of management for Budd-Chiari syndrome: a team's view from 2564 patients.

AIM: Exploring the development of therapy for a formerly rare and life-threatening disorder, Budd-Chiari syndrome (BCS). METHODS: From 1981 to 2003, 2677 patients with BCS were admitted including 2546 cases that underwent intervention. Therapeutic means included 170 membranotomies, 181 cavoatrial shunts, 312 mesoatrial shunts including mesocavoatrial shunt, 67 mesojugular shunts, 232 radical resections, 1289 PTA, and 295 miscellaneous procedures. RESULTS: Patients treated in the first decade had an effective rate of 77.7%, patency for various approaches was approximately 60-90% at 7 years. In our early experience, 55.7% patients underwent shunts, 26.1% had the transcardiac membranotomy and only 0.8% the interventional modality. Recently this has shifted to 16.2%, 5.2%, and 55.6%, respectively (P < 0.01). In the early phase, 11.6% of patients were classified as stage I (less clinical severity), and 28.6% patients in stage IV (most severe). In contrast, recent patients, they were 56.1% and 4.8% (P < 0.01). CONCLUSION: Chronologically, therapy has evolved from the relatively simple to the more complex (such as variety of shunts and radical correction) procedures, and finally, the interventional approaches as the main modality. However, for patients with type II (long segment occlusion in the inferior vena cava), major procedures maintain an essential role, especially the mesocavoatrial shunt. For those with type III (the HV lesions), shunts remain the procedures of choice. This increased use of the interventional methods is a reflection of greater clinical awareness and more frequent detection of much less severe cases. In stark contrast is declining numbers of advanced cases, signalling a landmark breakthrough in the management of BCS.

Adolescent↗
PubMed1989

Efficacy of drug prophylaxis.

With the spread of chloroquine resistant Plasmodium falciparum the control of malaria has become increasingly complex. In recent years, particular concern has arisen over how best to prevent malaria in non-immune international travellers. Prior to the recognition of the potential toxicity of some antimalarial drugs, malaria preventive guidelines switched from chloroquine to the newer compound antimalarial drugs and to amodiaquine; this adjustment was made when sentinel cases alerted clinicians that breakthrough infections occurred in travellers to East Africa taking chloroquine prophylaxis. Changes were also supported by data derived from field studies illustrating the effectiveness of these drugs for therapy in indigenous populations. However, international studies have now documented serious adverse reactions to pyrimethamine/dapsone, pyrimethamine/sulphadoxine, and amodiaquine, and caution is required with their use. Rates in British users concur with international estimates. Specialists preparing malaria preventive guidelines have, therefore, preferred to recommend the use of relatively safe antimalarial drugs, like chloroquine and proguanil, provided they offer non-immune travellers adequate protection against P. falciparum infections. Substantial difficulty has arisen, however, in the definition of 'adequate protection'. Field studies in indigenous communities with partial immunity can provide concise biological measures of parasite resistance to drugs. Unfortunately, these data cannot be used directly to determine the expected efficacy of chemoprophylactic drugs in non-immune populations. The transmission of malaria and the degree and intensity of resistance vary even within small geographical areas. Comprehensive patterns of resistance cannot be mapped out on a countrywide or regional basis for logistic reasons, and are restricted focally to discrete study locations.(ABSTRACT TRUNCATED AT 250 WORDS)

Africa↗