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J J Meuzelaar

Publications and source records attributed to J J Meuzelaar.

At least 19 recordsLinked to original sources
PubMed2001

No cytogenetic evidence for involvement of gene(s) at 2p16 in sporadic cardiac myxomas: cytogenetic changes in ten sporadic cardiac myxomas.

Cardiac myxomas are significant causes of cardiovascular morbidity and mortality. Their genetic background is presently unknown. Recently, linkage analysis in cardiac myxomas of Carney complex patients has indicated that 2p16 and 17q2 might carry genes responsible for the development of hereditary cardiac myxomas. Less is known about sporadic cardiac myxomas. To date, cytogenetic analysis has been performed on 13 sporadic cases, and no specific rearrangement has been deduced. We studied 15 sporadic cardiac myxomas and reviewed the literature. Ten of the present cases revealed abnormal karyotypes with clonal and nonclonal rearrangements including dicentric chromosomes and telomeric associations. No cytogenetic evidence was found for a role of 2p16 in the development of sporadic cases. Region 17q2 was involved in structural rearrangements, but to a lesser extent than other regions. Structural rearrangements involving regions 12p1 and 17p1 are more frequently present and might therefore harbor genes important for the development of sporadic cardiac myxomas.

Adult↗
PubMed2000

Preoperative staging of non-small-cell lung cancer with positron-emission tomography.

BACKGROUND: Determining the stage of non-small-cell lung cancer often requires multiple preoperative tests and invasive procedures. Whole-body positron-emission tomography (PET) may simplify and improve the evaluation of patients with this tumor. METHODS: We prospectively compared the ability of a standard approach to staging (computed tomography [CT], ultrasonography, bone scanning, and, when indicated, needle biopsies) and one involving PET to detect metastases in mediastinal lymph nodes and at distant sites in 102 patients with resectable non-small-cell lung cancer. The presence of mediastinal metastatic disease was confirmed histopathologically. Distant metastases that were detected by PET were further evaluated by standard imaging tests and biopsies. Patients were followed postoperatively for six months by standard methods to detect occult metastases. Logistic-regression analysis was used to evaluate the ability of PET and CT to identify malignant mediastinal lymph nodes. RESULTS: The sensitivity and specificity of PET for the detection of mediastinal metastases were 91 percent (95 percent confidence interval, 81 to 100 percent) and 86 percent (95 percent confidence interval, 78 to 94 percent), respectively. The corresponding values for CT were 75 percent (95 percent confidence interval, 60 to 90 percent) and 66 percent (95 percent confidence interval, 55 to 77 percent). When the results of PET and CT were adjusted for each other, only PET results were positively correlated with the histopathological findings in mediastinal lymph nodes (P<0.001). PET identified distant metastases that had not been found by standard methods in 11 of 102 patients. The sensitivity and specificity of PET for the detection of both mediastinal and distant metastatic disease were 95 percent (95 percent confidence interval, 88 to 100 percent) and 83 percent (95 percent confidence interval, 74 to 92 percent), respectively. The use of PET to identify the stage of the disease resulted in a different stage from the one determined by standard methods in 62 patients: the stage was lowered in 20 and raised in 42. CONCLUSIONS: PET improves the rate of detection of local and distant metastases in patients with non-small-cell lung cancer.

Adult↗
PubMed1999

[Dyspnea caused by bullae in a muscular dystrophy patient on chronic intermittent ventilatory support].

A 65-year-old patient, ex-smoker, with facioscapulohumeral muscular dystrophy (FSHD) had been on home non invasive ventilatory support for three years when he experienced gradual increase of dyspnoea. The chest radiograph showed large bullae occupying most of the right hemithorax, with compression of lung tissue, mediastinal shift, and compression of the left lower lobe. Bullectomy resulted in rapid clinical and radiographic improvement. This is the first report of beneficial effects of emergency bullectomy in FSHD. Bullectomy has proved most successful in patients with localized bullae and compression of surrounding lung tissue. Patients with respiratory infections and bronchiectasis benefit less.

Aged↗
PubMed1999

[Pleural empyema in mechanically ventilated patients with pneumonia].

Two males aged 41 and 32 years developed pneumonia which responded inadequately to antibiotic treatment and necessitated mechanical ventilation. It was only after surgical and digital opening, drainage of pus pockets and daily pleural lavage that the clinical picture improved. The microorganisms cultured from both patients included Streptococcus milleri, probably acquired by aspiration. Thoracic empyema as a complication of pneumonia is clinically recognised by lack of response to antimicrobial agents. For the diagnosis, ultrasonographic and CT imaging, followed by pleural puncture are used. Simple parapneumonic effusions are managed by drainage with or without rinsing with normal saline, while in advanced empyema, instillations with fibrinolytic agents have proved safe and effective. Sometimes, video-assisted thoracoscopic or conventional surgery is necessary to clear the pleural space, while in complicated cases, extensive surgical procedures are warranted.

Adult↗
PubMed1998

Thymic cyst haemorrhages and transient cholestasis in a 4-week-old infant.

UNLABELLED: We report a 4-week-old boy with acute respiratory distress, due to massive haemorrhages in multiple thymic cysts. A right hemithymectomy was performed because of mechanical obstruction of the trachea by the cysts. The origin of the multilocular thymic cysts remained unclear. Most likely, these haemorrhages were caused by vitamin K deficiency, although the infant received vitamin K prophylaxis. In addition, he developed transient cholestasis, but the aetiology remained unclear. It is postulated that massive haemorrhages in thymic cysts produce large amounts of bilirubin, causing sludging of bile excretions in the liver. Four weeks after the operation, all laboratory findings were normal and 6 months after the operation the boy is still healthy. CONCLUSION: This case report shows that respiratory distress in an infant can be caused by multiple haemorrhages in multilocular thymic cysts.

Cholestasis↗
PubMed1996

[Results of 75 lung transplantations performed in Groningen in 1990-1995. Lung Transplantation Group Groningen].

OBJECTIVE: To describe the development of the lung transplantation programme in Groningen, and the results of single and bilateral lung transplantations in the first 75 consecutive patients, up to December 1995. DESIGN: Retrospective. SETTING: Academic Hospital Groningen, the Netherlands. METHODS: The results of the lung transplantation programme were evaluated retrospectively. RESULTS: In November 1990 the first unilateral lung transplantation was performed in Groningen in a patient with pulmonary fibrosis. In February 1991 a national lung transplantation programme for the Netherlands was instituted in Groningen by the government. Of 500 patients referred from all over the Netherlands from 1990 to December 1995, 75 were transplanted, 16 unilaterally and 59 bilaterally. The actuarial survival for all patients was 85% after 1 year and 72% after 2 years. After transplantation 16 patients died (21%) after 15 months follow-up (median). Early mortality (5%) was caused by graft failure, late mortality (16%) by chronic rejection and lymphoproliferative disease. The mean time on the transplantation waiting list was 9.3 months; it increased during the programme. The limiting factor for further expansion of the programme was caused by donor scarcity. The lungs from only 16% of the multiorgan donors reported by Eurotransplant to our centre could be transplanted. CONCLUSION: The results of the lung transplantation programme in Groningen are good but with an increasing number of lung transplantation centres in the Eurotransplant region the further development of lung transplantation in the Netherlands will depend mainly on the availability of lung donors from the Netherlands.

Adolescent↗
PubMed1996

Effects of isoproterenol infusion on the myocardial uptake of fatty acids and other substrates in lambs with an aortopulmonary shunt.

Isoproterenol, used in the management of infants with left-to-right shunts and circulatory congestion, increases myocardial work load and oxygen consumption. In addition, it may selectively enhance myocardial fatty acid utilization. The less efficient oxidation of FFA could induce an oxygen wasting effect and thus further increase myocardial oxygen consumption. The combination of such an oxygen wasting effect and the chrono- and inotropic effects of isoproterenol could induce an imbalance between myocardial oxygen supply and demand in hearts of which resting oxygen consumption is already elevated. We studied myocardial substrate uptake (FFA, triglycerides, glucose, lactate, pyruvate, beta-OH-butyrate, and acetoacetate) in 10 7-wk-old lambs with an aortopulmonary left-to-right shunt (57 +/- 4% of left ventricular output, mean +/- SEM) and 9 control lambs during isoproterenol infusion (0.1 mumol.min-1.kg-1). Myocardial blood flow and oxygen consumption increased in both groups but less in shunt than in control lambs because of the smaller rise in heart rate in the shunt lambs. The arterial FFA concentration increased 3-fold in both groups and was not different between the two groups. The FFA arteriocoronary sinus difference, however, was not affected by the isoproterenol infusion. The myocardial FFA uptake thus followed the changes in myocardial blood flow and did not increase more in shunt than in control lambs. Isoproterenol infusion does, in spite of a 3-fold increase in arterial FFA concentration, not induce a shift toward a greater percentage uptake of fatty acids compared with other substrates in lambs with aortopulmonary left-to-right shunt, so that the possibility of an oxygen wasting effect can be ruled out as an unwanted side effect.

Animals↗
PubMed1995

Rearrangements involving 12p12 in two cases of cardiac myxoma.

Recently, we reported on the cytogenetic analysis of a case of cardiac myxoma, revealing a 46,XY,der(7)t(7;17)(p21;p11), add (10) (q22), add (12) (p12), del(17)(p11) chromosomal pattern. In this article we present the cytogenetic analysis of another case of cardiac myxoma, in which we found several clonal and nonclonal abnormalities including dicentric chromosomes and telomeric associations (tas). One of the clonal aberrations was a translocation between chromosomes 1 and 12, involving a breakpoint at 12p12, as observed in the case described earlier. This finding suggest that 12p12 might play an important role in the histogenesis of cardiac myxomas.

Aged↗
PubMed1994

Effects of exercise and isoproterenol on hemodynamics and myocardial VO2 in lambs with aortopulmonary shunts.

To compare hemodynamic changes induced by isoproterenol and exercise stress tests in individuals with and without left ventricular volume load, we studied 10 lambs with an aortopulmonary shunt [58 +/- 4% (SE) of left ventricular output] 2 wk after the shunt was created. Two studies, isoproterenol infusion at 0.1 microgram.kg-1.min-1 and treadmill exercise at 76 +/- 4% of predetermined maximal O2 consumption (VO2) were performed in each lamb in random order on different days. Identical experiments were performed in nine lambs without shunts. Isoproterenol and exercise induced similar changes in heart rate (43 +/- 5%); systemic (72 +/- 7%), pulmonary (35 +/- 3%), and shunt blood flows (8 +/- 6%); and stroke volume (NS) in shunt lambs. Aortic systolic pressure increased less during isoproterenol infusion than during exercise (7 +/- 3 vs. 27 +/- 5%), and left atrial pressure decreased during isoproterenol infusion (-23 +/- 4%) but changed in an opposite direction during exercise (7 +/- 6%). These changes were accompanied by a smaller increase in myocardial VO2 during isoproterenol infusion than during exercise (5.0 +/- 0.7 to 5.3 +/- 0.6 and 5.3 +/- 0.8 to 7.3 +/- 0.9 mumol.beat-1 x 100 g-1, respectively). In control lambs, stroke volume decreased during isoproterenol infusion despite an equal decrease in left atrial pressure as in shunt lambs. In conclusion, isoproterenol better stimulates the blood flow changes during exercise in shunt than in control lambs probably because of their higher ventricular filling pressures. In interpreting isoproterenol stress tests it should, however, be kept in mind that these changes are realized at a lower work load for the heart.

Animals↗
PubMed1994

Pneumatosis intestinalis and active cytomegaloviral infection after lung transplantation. Groningen Lung Transplant Group.

Pneumatosis intestinalis occurred in a patient with a primary cytomegaloviral (CMV) infection with pneumonitis 6 weeks after single lung transplantation for primary pulmonary hypertension. The possible causal relationship between pneumatosis intestinalis, an uncommon disorder with an obscure pathogenesis, and active CMV infection has been observed before; however, to our knowledge, this is the first report of this combination after lung transplantation. The patient had no abdominal complaints, and after treatment of the CMV infection, the pneumatosis intestinalis resolved spontaneously. The early diagnosis of active CMV infection and the prevention of unnecessary abdominal surgery were essential in this case.

Adult↗
PubMed1993

Myocardial blood flow and VO2 in lambs with an aortopulmonary shunt during strenuous exercise.

To determine how much myocardial O2 consumption (VO2) would increase during an additional load on the heart in shunt as compared with control lambs, we studied 12 7-wk-old lambs with an aortopulmonary left-to-right shunt (59 +/- 3% of left ventricular output, mean +/- SE) and 11 control lambs during exercise at 80% of their predetermined peak VO2 (VO2peak), at 12 +/- 1 days after surgery. During exercise, systolic aortic pressure increased by 25% in the two groups. Left atrial pressure and left ventricular stroke volume did not change significantly and remained considerably higher in shunt than in control lambs. Heart rate, however, increased less in shunt than in control lambs (163 +/- 8 to 235 +/- 8 vs. 107 +/- 7 to 230 +/- 8 beats/min). The same was true for left ventricular myocardial blood flow (245 +/- 19 to 391 +/- 27 vs. 128 +/- 10 to 320 +/- 45 ml.min-1 x 100 g-1) and myocardial VO2 (847 +/- 101 to 1,692 +/- 136 vs. 528 +/- 58 to 1,579 +/- 178 mumol O2 x min-1 x 100 g-1). We conclude that, despite the volume load, myocardial VO2 of shunt lambs does not increase to a greater extent than in control lambs during a considerable additional load on the heart.

Anastomosis, Surgical↗
PubMed1993

Myocardial substrate uptake in lambs with and without aortopulmonary shunts during strenuous exercise.

Increased myocardial fatty acid uptake during acute exercise could adversely affect myocardial O2 consumption in lambs with left-to-right shunts, which would be unfavorable in view of their decreased coronary blood flow reserve. Therefore, we studied myocardial substrate uptake (glucose, lactate, pyruvate, free fatty acids, triglycerides, beta-hydroxybutyrate, and acetoacetate) in 10 7-wk-old lambs with an aortopulmonary left-to-right shunt [61 +/- 3% (SE) of left ventricular output] and 9 control lambs during strenuous treadmill exercise. The hemodynamic reaction to exercise was similar in shunt and control lambs. The peripheral metabolic response to exercise was also similar in the two groups: glucose free fatty acids, and, most prominently, lactate concentrations increased. Myocardial O2 consumption increased but less in shunt than in control lambs because of a smaller increase in heart rate. In both groups myocardial lactate uptake increased substantially at the cost of other substrates, providing the heart with 40% of its oxidative metabolism. Fatty acid uptake was not different between the two groups. In conclusion, our data reveal no essential differences in myocardial substrate uptake between shunt and control lambs during a substantial circulatory load.

Animals↗