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Biomedical subjects

R J Snijder

Publications and source records attributed to R J Snijder.

13 recordsLinked to original sources
PubMed2006

Embolization of pulmonary arteriovenous malformations and decrease in prevalence of migraine.

OBJECTIVE: To determine if embolization of pulmonary arteriovenous malformations (PAVMs) decreases the occurrence of migraine. METHODS: All 105 patients with hereditary hemorrhagic telangiectasia (HHT), minimum age 16 years, who underwent an embolization of PAVM in our hospital between June 1995 and April 2004, were included in this study. A structured headache questionnaire was sent to all patients and focused on two periods: 1 year before and at least 6 months after embolization. Two independent neurologists diagnosed migraine according to the International Headache Society criteria. RESULTS: Eighty-four patients (80%) sent back the questionnaire (mean age 47.8 +/- 15.1 years, 51 female). Median follow-up time was 48 months (first quartile: 23 months; third quartile: 66 months). The overall prevalence of migraine decreased from 45.2% before to 34.5% after embolization (p = 0.01). The prevalence of migraine with aura decreased from 33.3% before to 19.0% after embolization (p = 0.002). The severity of headache attacks decreased in patients who still had migraine (p = 0.15) or migraine with aura after embolization (p = 0.11). CONCLUSION: Embolization of pulmonary arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia seems to be related to a decrease in prevalence of migraine, suggesting that the presence of a right-to-left shunt rather than the localization of this shunt plays a causative role in the pathogenesis of migraine.

Adult↗
PubMed2005

Genotype-phenotype relationship in hereditary haemorrhagic telangiectasia.

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by vascular malformations in multiple organ systems, resulting in mucocutaneous telangiectases and arteriovenous malformations predominantly in the lungs (pulmonary arteriovenous malformation; PAVM), brain (cerebral arteriovenous malformation; CAVM), and liver (hepatic arteriovenous malformation; HAVM). Mutations in the ENG and ALK-1 genes lead to HHT1 and HHT2 respectively. In this study, a genotype-phenotype analysis was performed. A uniform and well classified large group of HHT patients and their family members were screened for HHT manifestations. Groups of patients with a clinically confirmed diagnosis and/or genetically established diagnosis (HHT1 or HHT2) were compared. The frequency of PAVM, CAVM, HAVM, and gastrointestinal telangiectases were determined to establish the genotype-phenotype relationship. The analysis revealed differences between HHT1 and HHT2 and within HHT1 and HHT2 between men and women. PAVMs and CAVMs occur more often in HHT1, whereas HAVMs are more frequent in HHT2. Furthermore, there is a higher prevalence of PAVM in women compared with men in HHT1. In HHT1 and HHT2, there is a higher frequency of HAVM in women. HHT1 has a distinct, more severe phenotype than HHT2. There is a difference in the presence of symptoms between men and women. With these data, genetic counselling can be given more accurately when the family mutation is known.

Activin Receptors, Type II↗
PubMed2004

Hereditary hemorrhagic telangiectasia: ENG and ALK-1 mutations in Dutch patients.

Hereditary hemorrhagic telangiectasia (HHT) or Rendu-Osler-Weber disease is an autosomal dominant disorder characterized by an aberrant vascular development. The resulting vascular lesions range from smaller mucocutaneous telangiectases to large visceral arteriovenous malformations, especially in the skin, lung, gastrointestinal tract and the brain. Mutations in the genes encoding endoglin (ENG, chromosome 9q34) and activin A receptor type-like kinase 1 (ALK-1, also named ACVRL1, chromosome 12q13) are associated with HHT1 and HHT2, respectively. We report here on the genetic and molecular heterogeneity found in the HHT population in the Netherlands. Probands of 104 apparently unrelated families were studied and we performed sequence analysis on both the ENG gene and ALK-1 gene. In most of the probands, we found a mutation in one of the two genes: 53% in the ENG gene and 40% in the ALK-1 gene. In 7% of the families no ENG or ALK1 mutation was found. The mutations detected were deletions, insertions, nonsense, missense and splice site mutations. The majority were novel mutations.

Activin Receptors, Type I↗
PubMed2002

[Pulmonary thromboendarterectomy: an effective surgical treatment for cor pulmonale due to chronic pulmonary emboli].

OBJECTIVE: To evaluate the initial experience with pulmonary thromboendarterectomy for cor pulmonale due to chronic pulmonary embolism. METHOD: In the period 1 April 1996 to 31 October 2001, 18 patients with right ventricular failure due to chronic thromboembolic pulmonary hypertension were operated on. Their mean age was 54 (SD: 14) years. Preoperatively, all of the patients were in functional New York Heart Association (NYHA) class III or IV. Pulmonary angiography revealed pulmonary hypertension with an increased pulmonary vascular resistance, as well as typical angiographic signs of unresolved chronic emboli. Pulmonary thromboendarterectomy was performed via median sternotomy, using extracorporeal circulation and intermittent deep hypothermic circulatory arrest. The patients were monitored via the outpatients' department. RESULTS: From a technical viewpoint, the procedure was performed successfully in all of the patients. Initially the pulmonary thromboendarterectomy was performed unilaterally (n = 7), which did not decrease pulmonary artery pressure significantly. The following 11 patients were treated bilaterally; in them thromboendarterectomy required an average of circulatory arrest totalling 64 (SD: 30) min with 161 (SD: 35) min of myocardial ischemia. After bilateral pulmonary thromboendarterectomy, the pulmonary artery pressure decreased from 45 (SD: 13) to 28 (SD: 9) mmHg (p = 0.001). Reperfusion pulmonary oedema, requiring prolonged ventilation, occurred in 3 patients. There was no operative or later mortality. At a mean follow-up of 28 (SD: 19) months, all but one of the patients were in functional NYHA class I or II. Echocardiography revealed reduced right ventricular dimensions and pulmonary artery pressures. One patient, with mainly distally located obstructions, exhibited no substantial improvement. CONCLUSION: The initial experience with pulmonary thromboendarterectomy for patients with cor pulmonale due to chronic pulmonary emboli demonstrated satisfactory mid-term follow-up data.

Chronic Disease↗
PubMed2000

Lenograstim as support for ACE chemotherapy of small-cell lung cancer: a phase III, multicenter, randomized study.

This phase III study was conducted to evaluate the usefulness of lenograstim as support for ACE (doxorubicin, cyclophosphamide, and etoposide) chemotherapy in previously untreated patients with small-cell lung cancer. Patients were randomized to receive up to six 3-week cycles of either ACE alone (n = 139) or ACE with lenograstim support (150 microg/m2/day subcutaneously, days 4-13, n = 141). Compared with the chemotherapy-alone group, the lenograstim support group was more likely to achieve neutrophil recovery (absolute neutrophil count, > or =1.5 x 10(9) cells/l) by day 14 (95.8-100% vs. 14.3-24.1% across the cycles) and less likely to experience at least one infectious episode (36.7 vs. 54.0%; p = 0.004), chemotherapy delay (51.8 vs. 56.2%; NS), or dose reduction (17.3 vs. 27.7%; p = 0.037). Objective response and event-free and overall survival rates were similar. Lenograstim was well tolerated. Lenograstim may allow the interval between cycles of ACE to be reduced to 2 weeks; such dose intensification may lead to more favorable objective response and survival rates.

Adjuvants, Immunologic↗
PubMed1998

Survival in resected stage I lung cancer with residual tumor at the bronchial resection margin.

BACKGROUND: Sometimes microscopic residual tumor is found at the bronchial resection margin despite an apparently complete resection of lung cancer. This may adversely affect the patient's prognosis. Its impact on survival is unclear. METHODS: The records of 834 patients with resected stage I non-small cell lung cancer were studied. Patients with complete resection were assigned to the complete resection group (n = 802); patients with microscopic residual tumor at the bronchial resection margin that was accepted were assigned to the residual tumor group (n = 23). Residual tumor was classified as carcinoma in situ, mucosal residual disease, or peribronchial residual disease. RESULTS: The 5-year survival in the patients in the complete resection group was 54%; it was 58% in the residual tumor group with carcinoma in situ and 27.3% in the residual tumor group with invasive tumor (mucosal residual disease or peribronchial residual disease). The difference in survival between patients in the complete resection group and patients in the residual tumor group with invasive tumor was significant (p = 0.03). CONCLUSIONS: The presence of mucosal or peribronchial residual disease, but not carcinoma in situ, at the bronchial resection margin in patients with stage I non-small cell lung cancer has an adverse effect on survival.

Aged↗
PubMed1998

Evaluation of PCR, culture, and serology for diagnosis of Chlamydia pneumoniae respiratory infections.

We prospectively studied 156 patients with a diagnosis of community-acquired pneumonia requiring admission. Several respiratory specimens were obtained for the detection of Chlamydia pneumoniae by cell culture and PCR. Three serum samples were obtained from each patient. Serological diagnosis of a C. pneumoniae infection was determined by the microimmunofluorescence (MIF) test, the complement fixation (CF) test, and recombinant lipopolysaccharide (LPS) enzyme-linked immunosorbent assay (ELISA; referred to as the rDNA LPS ELISA). Twenty-three patients (15%) had serological results compatible with acute C. pneumoniae infection; nine (39%) of these subjects were C. pneumoniae PCR positive. Twenty-two patients (14%) had positive PCR results without serological evidence of an acute C. pneumoniae infection. An attempt was made to calculate the sensitivities and specificities of the MIF test, rDNA LPS ELISA, and PCR for the diagnosis of chlamydial community-acquired pneumonia. Several "gold standards" were defined. Generally, the sensitivities of the rDNA LPS ELISA and MIF were comparable, while the sensitivity of the CF test was shown to be very low. Independent of the gold standard used, the best PCR results were obtained with nasopharyngeal specimens. However, the predictive value of a positive C. pneumoniae PCR result for patients with community-acquired pneumonia remains unknown and may be low. Although a widely accepted gold standard is still lacking, the rDNA LPS ELISA may currently be the preferred tool for diagnosing acute respiratory Chlamydia infections in routine clinical practice. However, the MIF test remains the method of choice for determining the prevalence of C. pneumoniae infections in a given community.

Adolescent↗
PubMed1997

Lymph node type as a prognostic factor for survival in T2 N1 M0 non-small cell lung carcinoma.

BACKGROUND: Patients with stage II non-small cell lung carcinoma represent a group with varying 5-year survival rates. The influence of specific types of lymph node involvement on survival was investigated. METHODS: Of 2,009 patients operated on from 1977 through 1993, the cases of 391 patients with pathologic T2 N1 M0 disease were reviewed. The N1 status was refined into lymph node involvement by direct extension or by metastases in lobar or hilar lymph nodes. RESULTS: The cumulative 5-year survival rate of all hospital survivors (n = 369) was 37.8%. The 5-year survival rate of patients with lobar metastases was superior to that of patients with hilar metastases (57.3% versus 30.3%; p = 0.0028) and that of patients with lymph node involvement by direct extension (57.3% versus 39.1%; p = 0.03). The survival rate did not differ between those with hilar metastases and those with direct extension. Survival was significantly poorer in patients with visceral pleural involvement, in patients with adenocarcinoma, and in patients older than 60 years. Survival was not related to sex, type of resection, central growth, or tumor size. CONCLUSIONS: Survival differs according to the type of lymph node involvement: lobar lymph node metastasis seems to be an early stage of the disease, whereas hilar lymph node metastasis represents a more advanced form. However, in T2 N1 M0 disease, other factors besides nodal status also seem to play an important role in postoperative survival.

Carcinoma, Bronchogenic↗
PubMed1997

Diagnosis of Chlamydia pneumoniae infection in patients with chronic obstructive pulmonary disease by micro-immunofluorescence and ELISA.

The incidence of Chlamydia pneumoniae infection was determined in patients with chronic obstructive pulmonary diseases (COPD) by prospective serial serology. Chlamydia-specific IgG, IgM and IgA antibodies were detected with a recombinant DNA lipopolysaccharide (LPS) ELISA as well as with a micro-immunofluorescence (MIF) assay with C. pneumoniae elementary bodies. From 271 consecutive COPD patients who visited the outpatient clinic of the department of pulmonary diseases (211 males, 60 females, age range 34-88 years, mean age 66 SD 10 years), blood samples (n = 1058) were taken every 2-7 months; the observation period ranged from 3 to 19 months (mean 15 SD 4). The prevalence of chlamydial IgG was 72% with the MIF and 53% with the rDNA LPS ELISA. More than 90% of the COPD patients had no significant changes in their chlamydia-specific IgG, IgA and IgM titres in either test during the observation period. Seven (3%) patients had MIF results indicating acute C. pneumoniae infection during their surveillance period, of whom five were confirmed by rDNA LPS ELISA. Eleven (4%) additional patients were infected during observation, as determined by rDNA LPS ELISA only. These patients had significantly elevated C. pneumoniae-specific IgG and IgA MIF titres, as compared with the patients without infection. All 18 patients with serological evidence of acute infection during their surveillance period were re-tested in a commercial MIF test that can distinguish between C. pneumoniae, C. trachomatis and C. psittaci LPS-specific antibodies, but no evidence of C. trachomatis or C. psittaci infection was found. The incidence of chlamydial infection was 2.2 and 5.3/100 person-years, when diagnosed by MIF and rDNA LPS ELISA, respectively. It is concluded that the rDNA LPS chlamydia assay may currently be the most sensitive serological tool for diagnosing recent respiratory chlamydia infections and that C. pneumoniae infection occurs frequently in COPD patients.

Adult↗
PubMed1996

Type of lymph node involvement influences survival rates in T1N1M0 non-small cell lung carcinoma. Lymph node involvement by direct extension compared with lobar and hilar node metastases.

Stage II non-small cell lung cancer represents a group of patients with varying 5-year survival rates. Of 2,009 patients, we reviewed 58 patients with pT1N1M0 disease operated on from 1977 through 1994. The N1 status was refined into lymph node involvement by direct extension and/or involvement by metastases (lobar or hilar). The cumulative 5-year survival of all hospital survivors (n = 57) was 45.7%. The 5-year survival of patients with N1 direct extension was superior to survival of patients with N1 metastases (68.6% vs 31.2%; p = 0.0038). Survival of patients with N1 direct extension was better then survival of patients with N1 hilar metastases (p = 0.0006), but did not differ from survival of patients with lobar metastases. Survival was not related to histologic features, sex, and type of resection. Recurrence of malignancy occurred less in patients with N1 direct extension. In patients with N1 hilar nodes, the most common pattern was distant metastases. Survival differs according to the type of lymph node involvement: "direct extension" seems to be an early stage of the disease, while lymph node metastases represent a more advanced form.

Adult↗
PubMed1994

[Pulmonary hypertension following use of fenfluramine for obesity].

Pulmonary hypertension was diagnosed in a 41-year-old woman after 16 months' use of fenfluramine as a treatment for obesity. Despite discontinuation, pulmonary pressure remained elevated. Drug-induced pulmonary hypertension is rare but has been reported relatively often after use of the sympathicomimetic agent aminorexfumarate, but also, although more rarely, of fenfluramine.

Adult↗
PubMed1992

Age-related interference with Chlamydia pneumoniae microimmunofluorescence serology due to circulating rheumatoid factor.

Microimmunofluorescence (MIF) serology is commonly used in the diagnosis of chlamydial infections. In the MIF assay, Chlamydia pneumoniae elementary bodies were used to detect C. pneumoniae immunoglobulin G (IgG) and IgM antibodies in paired serum samples from 286 patients with respiratory illnesses. In 69 patients, MIF serology was compared with C. pneumoniae cultures. All C. pneumoniae cultures remained negative. However, 205 (71%) of 286 patients were C. pneumoniae antibody positive and 64 (22%) had MIF test results indicating recent infection; 11 showed a fourfold increase in IgG titer, 18 had IgG titers of greater than or equal to 1:512, and 41 had IgM titers of greater than or equal to 1:16. In 35 (55%) of 64 patients, a recent-infection diagnosis was based on C. pneumoniae IgM antibodies only. However, 78% of C. pneumoniae IgM-positive patients had circulating rheumatoid factor (RF) by rheumatoid arthritis latex assay. RF positivity increased with age. After absorption with anti-human IgG, all C. pneumoniae IgM-positive sera became C. pneumoniae IgM negative in the MIF assay. Twenty-five patients with active rheumatoid arthritis but without respiratory illness were also tested; 14 were C. pneumoniae IgG positive and C. pneumoniae IgM positive as well. Absorption of IgG from these RF-containing sera invariably resulted in disappearance of reactivity in the MIF IgM assay. We conclude that with age the serologic diagnosis of recent C. pneumoniae infection becomes increasingly prone to false-positive results unless sera are routinely absorbed prior to MIF IgM testing.

Adult↗