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Biomedical subjects

R M Berger

Publications and source records attributed to R M Berger.

At least 19 recordsLinked to original sources
PubMed2002

Snare retrieval of intracranial thrombus in patients with acute stroke.

Intravenous or intraarterial thrombolysis of intracranial emboli is becoming an accepted clinical treatment modality for acute ischemic stroke, but not all emboli respond to the lytic drug regimens available today. If drug therapy fails, mechanical retrieval seems warranted. Four patients whose condition was resistant to intravenous and intraarterial thrombolytic drug treatment underwent at least partial clot removal with use of a snare, and almost immediate clinical improvement was noted. A fifth patient's clot was removed before lytic drugs were administered. All five patients, who presented with a sudden onset of stroke, were evaluated by arterial angiography; then, after a failed trial of intraarterial fibrinolytic drugs, they were treated by passing a 2- or 4-mm snare through a microcatheter. The snare wire was guided around the thrombus, gently brought back toward the microcatheter-but not into it-and the entire microcatheter and snare assembly was then removed. In four of the five cases, follow-up angiography performed immediately after the retrieval showed wider distal branches than normal. Follow-up computed tomography results were abnormal in all cases, showing hyperdense material in the territory that was previously ischemic. This hyperdensity subsided within 48 hours in all but one patient who developed small parenchymal hemorrhages; however, he remained asymptomatic. The snare device offers an additional or alternative therapy until completely effective thrombolytic agents become available. Although use of a snare is not ideal, device improvements should make the retrieval less technically challenging and more effective. There is a need for improved mechanical extraction devices, especially in light of the patient improvement that occurred. This experience also suggests that immediate removal of a mature clot could reduce the total time of brain ischemia more quickly than administration of thrombolytic drugs.

Adult↗
PubMed2001

[Primary pulmonary hypertension: new treatment options].

Primary pulmonary hypertension (PPH) is a rare, progressive and life-threatening pulmonary vascular disease of unknown aetiology, which results in elevated pulmonary vascular resistance, pulmonary hypertension and eventually right ventricle failure. PPH occurs in all age groups, but most frequently in women aged 20-30 years old. The mean survival after the onset of symptoms is 2-3 years. Although the disease remains incurable at present, major advances in treatment options have been made during the last 10 years. This had led to a considerable improvement in extended survival and the quality of life in a substantial number of PPH patients. At present the most important treatment options include anticoagulants, calcium channel antagonists, chronic prostacyclin therapy (cost of this only reimbursed by health insurers in the Netherlands since 1999) and if needs be lung or heart-lung transplantation. Chronic continuous intravenous administration of epoprostenol is burdensome for the patient and requires adequate patient selection and a well-developed intramural and extramural infrastructure.

Adult↗
PubMed2001

The semi-elective use of the pulmonary artery flotation catheter in children with progressive pulmonary hypertension or left ventricular dysfunction.

OBJECTIVE: To describe the experience with the semi-elective use of the pulmonary artery flotation catheter in pediatric patients with progressive pulmonary hypertension or left ventricular dysfunction. DESIGN: Prospective study. SETTING: Pediatric intensive care unit in a tertiary care center. PATIENTS: Seven consecutive children with pulmonary hypertension and ten children with left ventricular dysfunction. INTERVENTIONS: Drug-response studies were performed using a pulmonary artery flotation catheter. Cardiac index, systemic and pulmonary blood pressure, and occlusion pressure were measured during incremental doses of calcium channel blocker (diltiazem) that were administered to children with pulmonary hypertension and during incremental doses of nitroglycerine and angiotensin-converting enzyme-inhibitor (captopril) that were administered to patients with left ventricular dysfunction. MAIN RESULTS: Four patients (60%) with pulmonary hypertension were identified as responders to calcium channel blockers, resulting in maintenance therapy with high-dose diltiazem in three of them. Nine patients (90%) with left ventricular dysfunction showed a >15% increase in cardiac index with vasodilator therapy. Eleven patients (65%) developed fever during the procedure. Nine patients (53%) had a high probability of bacterial infection. Seven patients (40%) died within 3.5 months after the procedure. Fever, infection, and mortality appeared to occur more frequently in patients in New York Heart Association classes III and IV. CONCLUSIONS: The use of a pulmonary artery flotation catheter enables us to optimize medical treatment strategies in the individual child with progressive pulmonary hypertension or left ventricular dysfunction. Children with left ventricular dysfunction in poor clinical condition showed a high mortality rate post or propter the procedure. In our opinion, drug-response studies using pulmonary artery flotation catheters in patients with left ventricular dysfunction should be performed in a relatively early stage of the disease.

Journal Article↗
PubMed2001

Does reversal of ischemia on diffusion-weighted imaging reflect higher apparent diffusion coefficient values?

This study investigated whether ischemia on diffusion-weighted imaging (DWI) that reverses has higher apparent diffusion coefficients (ADCs). A patient treated with thrombolytics was evaluated with serial magnetic resonance imaging studies before treatment, at 3 and 14 days and at 4 weeks. A 100.01-cm3 left frontoparietal stroke on baseline DWI was only 18.11 cm3 (18%) on 4-week fluid attenuated inversion recovery. The mean ADC was 7.43 x 10(-3) mm2/s in the 6 regions that reversed and 7.31 x 10(-3) mm2/s in the 6 regions that persisted (P < .036). With thrombolytic treatment, large ischemic lesions on DWI may reverse, and these areas display higher mean ADCs.

Brain Ischemia↗
PubMed2001

Altered arterial expression patterns of inducible and endothelial nitric oxide synthase in pulmonary plexogenic arteriopathy caused by congenital heart disease.

Flow-associated pulmonary hypertension leads to pulmonary plexogenic arteriopathy (PPA), a specific pulmonary vascular disease that includes vascular lesions characterized by abnormal vasodilatation and endothelial cell proliferation. Increased local production of NO has been suggested in this condition. Because reported data on the expression of endothelial NO-synthase (ecNOS) have been contradictory, we speculated that the expression of the inducible isoform of NOS (iNOS) is enhanced in this form of pulmonary hypertension. We investigated immunohistochemically the expression of ecNOS and iNOS in lung tissue of patients with flow-associated pulmonary hypertension (n = 18) and compared the findings with those in patients with increased pulmonary blood flow but normal pulmonary artery pressure (n = 10), with congestive vasculopathy (n = 6) and control subjects (n = 4). Immunoreactivity for ecNOS and iNOS was present both in normal and diseased pulmonary arteries. Marked immunoreactivity to both isoforms was present within the advanced lesions of PPA, including plexiform lesions. Semiquantitative analysis of immunoreactivity, both for ecNOS and iNOS, showed no correlation with the severity of morphologic vascular lesions (p = 0.29 and p = 0.23, respectively). In contrast to ecNOS, immunoreactivity for iNOS was increased in patients with flow-associated pulmonary hypertension compared with other patients (p = 0.02). The present study has demonstrated enhanced expression of iNOS in patients at risk for advanced PPA, but not in patients with other forms of pulmonary arteriopathy. Moreover, high expression of both ecNOS and iNOS were present in advanced lesions of PPA. These data suggest differentiated roles for different isoforms of NOS in the pathogenesis of this specific pulmonary arteriopathy.

Analysis of Variance↗
PubMed2000

Enhanced expression of vascular endothelial growth factor in pulmonary plexogenic arteriopathy due to congenital heart disease.

Congenital heart disease (CHD) leading to increased pulmonary blood pressure and flow is an important cause of pulmonary plexogenic arteriopathy (PPA). This type of arteriopathy tends to progress to an irreversible stage, hallmarked histologically by the emergence of a number of characteristic lesions, which include concentric laminar intimal proliferation and fibrosis, and plexiform lesions. The pathogenesis of these lesions, which connote a very poor prognosis, is not well understood. Since endothelial cell proliferation has been demonstrated in these lesions, it was hypothesized that vascular endothelial growth factor (VEGF), a key mediator of angiogenesis, might play a role in their pathogenesis. Thirty-nine patients with various types of CHD, who underwent cardiac catheterization and subsequent cardiac surgery, were studied prospectively. On the basis of a detailed assessment of the type of cardiac defect, the haemodynamic abnormalities, and the histopathological features evident from open lung biopsies, taken in all instances, patients were histologically grouped into cases with moderate PPA (n=18), advanced PPA (n=7), pulmonary congestive vasculopathy (PCV, n=5), and controls lacking pulmonary hypertension or increased pulmonary blood flow (n=4). Five patients were excluded from analysis because of inadequate sample size or quality. The presence of VEGF was assessed immunohistochemically using standard procedures and was correlated with haemodynamic and histological data. Immunoreactive VEGF was detected in pulmonary arterial smooth muscle cells and endothelial cells in 13 out of 34 cases and was more frequent and more pronounced in patients with the histological lesions of advanced PPA than in those with moderate PPA (p<0.01). VEGF positivity was particularly prominent in the lesions characteristic of advanced PPA. No difference in VEGF expression was observed between controls, PVC, and moderate PPA cases. Measured haemodynamic parameters did not differ significantly between VEGF-positive and VEGF-negative cases. We conclude that VEGF may play a role in the angioproliferative changes of advanced PPA.

Child↗
PubMed2000

Autoimmune lymphoproliferative syndrome (ALPS) in a child from consanguineous parents: a dominant or recessive disease?

Autoimmune lymphoproliferative syndrome (ALPS) is characterized by autoimmune features and lymphoproliferations and is generally caused by defective Fas-mediated apoptosis. This report describes a child with clinical features of ALPS without detectable Fas expression on freshly isolated blood leukocytes. Detection of FAS transcripts via real-time quantitative PCR made a severe transcriptional defect unlikely. Sequencing of the FAS gene revealed a 20-nucleotide duplication in the last exon affecting the cytoplasmic signaling domain. The patient was homozygous for this mutation, whereas the consanguineous parents and the siblings were heterozygous. The patient reported here is a human homologue of the Fas-null mouse, inasmuch as she carries an autosomal homozygous mutation in the FAS gene and she shows the severe and accelerated ALPS phenotype. The heterozygous family members did not have the ALPS phenotype, indicating that the disease-causing FAS mutation in this family is autosomal recessive.

Autoimmune Diseases↗
PubMed1999

Vascular rings: a rare cause of common respiratory symptoms.

Upper airway symptoms or dysphagia may be caused by vascular anomalies, forming a ring around the trachea, oesophagus or both. To analyse the clinical presentation, use of various diagnostic techniques, treatment and follow-up we carried out a retrospective study of 38 children who had been diagnosed with a vascular ring between 1981 and 1996. We found 74% of the vascular rings to be symptomatic, with inspiratory stridor and wheezing as the main complaints. The delay between the onset of symptoms and diagnosis of a vascular ring in patients without associated anomalies ranged from 1 to 84 mo. Associated anomalies were found in 53% of cases and 80% of these anomalies consisted of associated cardiovascular malformations. Oesophagography proved to be a valuable diagnostic technique when a vascular ring was suspected. Echocardiography appeared to be of little value for the diagnosis of a vascular ring, but was essential to exclude associated cardiovascular malformations. Although angiography has always been considered to be the gold standard in the determination of the exact anatomy of vascular rings, increasing evidence is available that CT scan or MRI may replace this role. Mortality was related to co-existent tracheal deformities in 5/6 cases. Of the remaining, preoperatively symptomatic patients, relief of symptoms was achieved immediately after surgery in 43% and within 4 y after surgery in 57%. Prolonged and recurrent respiratory complaints or dysphagia in infancy or childhood should alert the paediatrician to the possibility of a vascular ring.

Aorta, Thoracic↗
PubMed1998

[Sudden death in young persons caused by arrhythmogenic right ventricular dysplasia].

A previously healthy boy aged 14 developed persistent ventricular tachycardia while engaged in sports; ultrasonography revealed arrhythmogenic right ventricular dysplasia (ARVD). He was treated with a class III antiarrhythmic drug but nevertheless died 4 years later during recreational activities. An uncle of the boy was found to have died suddenly on a playing field, 25 years previously at the age of 20. In ARVD, fibrolipomatous areas in the right ventricle lead to dilations of the wall where (sometimes fatal) re-entrant tachycardias may develop. An autosomal dominant heredity with variable expression and penetrance is considered probable, while the genetic defect was located recently. Examination and, if necessary, pharmacotherapy of relatives of an ARVD patient may reduce the risk of a fatal arrhythmia.

Adolescent↗
PubMed1998

Heparin as a risk factor for perigraft seroma complicating the modified Blalock-Taussig shunt.

OBJECTIVE: The purpose of this study was to determine the risk factors associated with the occurrence of perigraft seromas complicating systemic-to-pulmonary polytetrafluoroethylene grafts. METHODS: Clinical and perioperative variables were reexamined, blinded for the outcome variable perigraft seroma, in 60 patients undergoing 67 consecutive graft procedures in a 3.5-year period. RESULTS: Eight cases of perigraft seroma were diagnosed in six patients. Univariate analysis revealed age (p = 0.02), a diagnosis of pulmonary atresia with ventricular septal defect and systemic-pulmonary collaterals (p = 0.001), reimplantation of collaterals during the procedure (p < 0.001), and intravenous heparin administered after operation (p < 0.0001) as risk factors for symptomatic perigraft seroma. Multivariable analysis defined heparin as the only significant factor associated with symptomatic perigraft seroma. Consolidation of the upper lobe on chest radiograph, ipsilateral to the shunt, directly after operation (p = 0.01), but especially 8 to 10 days after operation (p < 0.0001), or the need for prolonged drainage of pleural fluid (p < 0.0001) were correlated with the occurrence of perigraft seroma. Perigraft seroma led to four early rethoracotomies in three patients and to accelerated corrective surgery in three cases. Consolidation and absent perfusion of lung segments persisted in two patients. CONCLUSIONS: Our data suggest that the use of heparin leads to an increased risk of perigraft seroma, complicating systemic-pulmonary polytetrafluoroethylene grafts. Prolonged pleural drainage and/or postoperative consolidation of the upper lobe indicate the development of symptomatic perigraft seroma. Treatment is controversial and results are unpredictable. Expectative management seems to be justified so long as permitted by the clinical condition.

Anastomosis, Surgical↗
PubMed1996

A predictive model to estimate the risk of serious bacterial infections in febrile infants.

UNLABELLED: Low risk criteria have been defined to identify febrile infants unlikely to have serious bacterial infection (SBI). Using these criteria approximately 40% of all febrile infants can be defined as being at low risk. Of the remaining infants (60%) only 10%-20% have an SBI. No adequate criteria exist to identify these infants. All infants aged 2 weeks-1 year, presenting during a 1-year-period with rectal temperature > or = 38.0 degrees C to the Sophia Children's Hospital were included in a prospective study. Infants with a history of prematurity, perinatal complications, known underlying disease, antibiotic treatment or vaccination during the preceding 48 h were excluded. Clinical and laboratory variables at presentation were evaluated by a multivariate logistic regression model using SBI as the dependent variable. By using likelihood ratios a predictive model was derived, providing a post test probability of SBI for every individual patient. Of the 138 infants included in the study, 33 (24%) had SBI. Logistic regression analysis defined C-reactive protein (CRP), duration of fever, standardized clinical impression score, a history of diarrhoea and focal signs of infection as independent predictors of SBI. CONCLUSION: CRP, duration of fever, the "standardized clinical impression score", a history of diarrhoea and focal signs of infection were the independent, most powerful predictors of SBI in febrile infants, identified by logistic regression analysis. Although the predictive model is not validated for direct clinical use, it illustrates the clinical potential of the used technique. This technique offers the advantage of assess the probability of SBI in every individual infant. This probability will form the best basis for well-founded decisions in the management of the individual febrile infant.

Bacterial Infections↗
PubMed1995

Evaluation of the pulmonary vasculature and dynamics with intravascular ultrasound imaging in children and infants.

The ability to assess the pulmonary vasculature in pulmonary vascular disease by hemodynamic or histologic evaluation is limited. We sought to determine the feasibility of intravascular ultrasound techniques in infants and children and to assess simultaneously the morphology and dynamics of pulmonary arteries. Patients were seen in the Department of Pediatrics, Division of Pediatric Cardiology, Sophia Children's Hospital, Rotterdam, The Netherlands. We performed intravascular ultrasound imaging in 11 pediatric patients with congenital heart disease undergoing cardiac catheterization. Luminal diameter, area, and pulsatility were determined at two to five sites in the pulmonary branches. Pulmonary vascular reaction to 100% oxygen inhalation was studied. Patients weighed 4.1-51.0 kg (21.8 +/- 16.3 kg, mean +/- SD). Luminal diameters, areas, and pulsatilities could be determined reproducibly in arteries with diameters from 1.6 to 9.3 mm. In total 39 sites were studied in 11 patients. Pulsatility was related to vessel size (r = 0.81), although a substantial interindividual variation was present. After 100% oxygen inhalation, pulsatility increased in all arteries (from 20.0 +/- 3.3% to 25.9 +/- 2.9%, p < 0.05), and vasodilatation could be directly visualized, most prominently in the smallest arteries (percentage change in diameter, mean 7.4 +/- 2.8% versus -2.8 +/- 3.1% in the largest arteries, p < 0.001). Measurement of wall thickness was not feasible, but specific changes in the appearance of the wall structure could be recognized in a patient with severely elevated pulmonary vascular resistance. The specific advantages of intravascular ultrasound in assessing pulmonary vascular disease are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Study of pertussis vaccines in infants: comparison of response to acellular pertussis DTP vaccines containing 25 micrograms of FHA and either 25 or 8 micrograms of PT with response to whole-cell pertussis DTP vaccine.

Clinical and serological responses of infants to primary vaccination with diphtheria-tetanus-acellular pertussis (DTPa) vaccines containing 25 micrograms of filamentous haemagglutinin (FHA) and either 25 or 8 micrograms of pertussis toxoid (PT) were compared in a double-blind randomized study with responses of infants receiving whole-cell pertussis DTP vaccine (DTPw). In total, 308 healthy infants were enrolled to receive three vaccine doses at 3, 4 and 5 months of age. DTPa recipients had significantly lower incidences of local reactions and fever than the DTPw recipients. No differences in reactogenicity were observed between DTPa groups receiving 8 and 25 micrograms doses of PT. After vaccination, an immune response to PT was seen in 96% of 25 micrograms PT DTPa recipients, 94% of DTPw recipients and 86% of 8 micrograms PT DTPa recipients. The geometric mean anti-PT neutralizing antibody titre was significantly higher for 25 micrograms PT dose recipients (34.9 Chinese hamster ovary (CHO)) as compared with 8 micrograms PT dose recipients (21.0 CHO). The results support the use of the higher dose of PT in acellular pertussis vaccine preparations.

Adhesins, Bacterial↗