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W Moolenaar

Publications and source records attributed to W Moolenaar.

14 recordsLinked to original sources
PubMed1996

Cholesterol crystal embolization in the Netherlands.

OBJECTIVE: To clarify the incidence and clinical features of cholesterol crystal embolization (CCE). METHODS: Analysis of the relevant data of 842 diagnosed cases of CCE filed in the Dutch National Pathology Information System from 1973 through 1994. RESULTS: No report of CCE was recorded from 1973 through 1979. Since then, its incidence rose from 0.9 case per million population in 1980 to 6.0 cases per million population in 1985, but stabilized thereafter. Among autopsy reports, the relative percentage of CCE was similar over the years, with 0.35% in 1982 and 0.30% in 1994 (mean 0.31% range, 0.20% to 0.42%). Nine patients in whom CCE was found in their renal transplant were excluded from the study. Thus, among a total of 833 elderly (mean age, 72.1 years), predominantly male (73.9%) patients, 1066 CCE sites were found in 323 biopsy reports, 264 resection reports, and 287 autopsy reports. CONCLUSION: In the Dutch population, CCE is reported steadily, with an average frequency of 6.2 cases per million population per year since 1985. It occurs predominantly in elderly men with a history of atherosclerotic disease and hypertension. Symptoms may be absent, go unrecognized, or mimic other disease processes. It can also be a coincidental finding. The primary CCE site is the kidney, followed by the skin and gastrointestinal tract.

Aged↗
PubMed1996

Cholesterol crystal embolization to liver, gallbladder, and pancreas.

We retrospectively studied the clinical features of all 44 patients (35 men, 9 women, mean age 74.5 years) registered with a diagnosis of hepatic, biliary, and/or pancreatic cholesterol crystal embolization (CCE) in the Dutch National Pathology Information System (DNPIS) from 1973 through 1994. Liver CCE was found in 12 (11 autopsies and 1 biopsy), gallbladder CCE in 2 (resection specimens), pancreas CCE in 19 (18 autopsies and 1 biopsy), and both liver and pancreas CCE in 11 (all autopsies) patients. Five patients presented with focal liver cell necrosis, 1 with acalculous necrotizing cholecystitis, 1 with chronic cholecystitis, 10 with necrotizing pancreatitis, and 1 with chronic fibrosating pancreatitis. Four patients died of CCE-induced pancreatitis. Nineteen patients died as a consequence of other CCE sites. These were reported in 37 patients. All patients had a history of atherosclerotic vascular disease. In half the patients a possibly CCE provoking factor (vascular surgery and/or cannulation, anticoagulant treatment) was present. We conclude that liver cell necrosis, cholecystitis, and pancreatitis may be caused by CCE, particularly in elderly male patients with a history of atherosclerosis.

Aged↗
PubMed1996

Cholesterol crystal embolisation to the alimentary tract.

The features of cholesterol crystal embolisation (CCE) to the alimentary tract were studied by retrospective analysis of the clinical and pathological data of 96 patients (70 men, 26 women, mean age 73.8 (58-95) years) with this diagnosis in the Dutch national pathology information system (Pathologisch Anatomisch Landelijk Geautomatiseerd Archief (PALGA)) from 1973-92. In the 96 patients, 130 CCE sites were found throughout the alimentary tract, mostly in the colon (42.3%). Most patients had a history of atherosclerotic disease and presented with abdominal pain, diarrhoea, or gastrointestinal bleeding, sometimes after surgical or radiological vascular procedures. A number were taking oral anticoagulant treatment. The diagnosis of CCE had been considered before the histological diagnosis in only 11 patients. In the remaining cases, ischaemic colitis, tumour, and inflammatory bowel disease were suggested in the differential diagnosis. A premortem diagnosis of CCE was made in 70.8% of the cases. In 24 of the 35 necropsy examinations, CCE seemed to be directly or indirectly related to the cause of death. It is concluded that in this unselected, homogenous group of patients, CCE sites were most frequently found in the colon. They generally presented with abdominal pain, diarrhoea, and gastrointestinal blood loss. CCE often mimicked common gastrointestinal disease, leading to incorrect diagnosis.

Aged↗
PubMed1996

Triple therapy vs. amoxicillin plus omeprazole for treatment of Helicobacter pylori infection: a multicenter, prospective, randomized, controlled study of efficacy and side effects.

OBJECTIVE: this study compares the efficacy and side effects of the two commonly used treatment regimens for Helicobacter pylori infection. METHODS: 118 patients with culture-proven H. pylori infection (61 with duodenal ulcer, 19 with gastric ulcer, three with both duodenal and gastric ulcer, and 35 with non-ulcer dyspepsia) were randomized to receive either triple therapy (tetracycline 250 mg, metronidazole 250 mg, colloidal bismuth subcitrate 120 mg, four times daily) for 14 days or amoxicillin 1000 mg and omeprazole 40 mg both twice daily for 14 days. The isolated H. pylori strain was metronidazole susceptible in 93%. Antral biopsy samples were taken for culture, urease testing, histology and, in most patients, for PCR at least 6 wk after treatment. A separate corpus sample was taken for culture. Eradication was defined as the absence of H. pylori in all specimens. In seven cases, when only histology was doubtfully positive, and all other tests including PCR were negative, a 13C-urea breath test was performed, the result of which was recorded by the patient on a semi-quantitative scale. RESULTS: H. pylori was eradicated by triple therapy in 96.3% and by amoxicillin/omeprazole in 77.2% of the patients (p = 0.008). Side effects occurred more often with triple therapy (72.7% vs. 50.8%; p< 0.05) but were mild in most cases. Severe side effects occurred equally in both treatment groups. CONCLUSIONS: When the prevalence of metronidazole resistance is low, triple therapy is more effective than amoxicillin/omeprazole. Side effects occur more often in triple therapy but are mild in most cases.

Adult↗
PubMed1995

Gastrointestinal blood loss due to cholesterol crystal embolization.

Gastrointestinal blood loss in elderly atherosclerotic patients may be due to cholesterol crystal embolization (CCE) leading to ischemic lesions in the gastrointestinal tract. The diagnosis of CCE is favored by accompanying clinical or biochemical signs, such as blue toes, renal insufficiency, and eosinophilia. Our report describes the clinical data of four patients with gastrointestinal blood loss due to CCE. In two the bleeding source was in the duodenum, and in the other two the source was in the distal colon. The diagnosis was made by histological examination of endoscopic biopsies in three and of a sigmoid resection specimen in one. Provoking factors were anticoagulant therapy in one, anticoagulant therapy and aortography in another, and aortography followed by aorta bifurcation prosthesis implantation in the third, whereas no provoking factor could be identified in the remaining patient. Accompanying signs included eosinophilia in one, a blue toe with renal insufficiency in one, and retinal cholesterol crystals in another patient. Our findings, in line with previous reports, highlight the importance of CCE in the differential diagnosis of gastrointestinal blood loss in elderly patients.

Aged↗
PubMed1994

Short report: clarithromycin, an alternative to metronidazole in the triple therapy of Helicobacter pylori infection.

BACKGROUND: Triple therapy for Helicobacter pylori using metronidazole is less effective in patients with a metronidazole resistant strain. Moreover, metronidazole is responsible for many side-effects. This open study examined the efficacy and side-effects of a triple treatment regimen substituting clarithromycin for metronidazole. METHODS: 36 patients with a H. pylori infection, proven by culture, were treated with tripotassium dicitrato bismuthate 120 mg q.d.s., tetracycline 250 mg q.d.s. and clarithromycin 250 mg q.d.s. for 10 days. Eradication was defined as a negative culture and histological examination of antral biopsy specimens, taken at least 6 weeks after completion of the treatment. RESULTS: Eradication was achieved in 26 patients (72%). The treatment was well tolerated with only 4 (11%) of the patients having significant side-effects. CONCLUSION: Triple therapy with clarithromycin seems to be less effective than standard triple treatment when the prevalence of metronidazole resistance is low. It is suggested, however, that this combination could be a valuable alternative in areas with a high prevalence of metronidazole resistance.

Adult↗
PubMed1991

T-cell receptors and ICAM-1 expression in renal allografts during rejection.

Sixty-two biopsies taken from 38 kidney grafts were studied for 15 histological and 10 immunohistological parameters. The biopsies were divided into three groups, according to the clinical diagnosis at the time they were performed: group 1, rejection (n = 43); group 2, other causes of dysfunction (n = 10); and group 3, stable function (n = 9). Histological signs of acute rejection included diffuse interstitial infiltrate, tubular basement membrane damage, mononuclear leukocyte infiltration, and congestion of the peritubular capillaries. Immunoperoxidase staining with monoclonal antibodies to ten markers showed a statistically significant association between detection of T-cell receptor subunits alpha-beta (TcR2) and gamma-delta (TcR1) on infiltrating lymphocytes and of intercellular adhesion molecule-1 (ICAM-1) in tubular cells and acute rejection. These results suggest that T-cell receptors and ICAM-1 may be useful markers to differentiate acute rejection from renal graft dysfunctions due to other abnormalities.

Adult↗
PubMed1991

Cholesterol crystal embolization and the digestive system.

Atherosclerotic vascular disease can give rise to provoked or spontaneous cholesterol crystal embolization to organ systems. Lodging in downstream arterioles, these crystals can produce granuloma formation, infarction, ulceration, and perforation. Histologic sections of the tissue concerned invariably show pathognomonic empty needle-shaped clefts left by the crystals after processing of the material. In the digestive system these events can cascade to many and often misleading presentations. They can be the cause of massive bleeding, acute acalculous cholecystitis, pancreatitis, or teleangiectasis with chronic intractable blood loss. Owing to the progressive nature of the disease the treatment options described in this paper can only give temporary, but nevertheless often worthwhile relief.

Arterioles↗
PubMed1990

A pseudosubstrate peptide inhibits protein kinase C-mediated phosphorylation in permeabilized Rat-1 cells.

Activation of protein kinase C (PKC) in Rat-1 fibroblasts leads to rapid phosphorylation of an 80-kDa protein, a major substrate of PKC. Digitonin-permeabilized cells perfectly supported this early response. Introduction of a PKC pseudosubstrate peptide inhibited 80 kDa phosphorylation with an IC50 of 1 microM, while a control peptide had no effect. The results indicate that this semi-intact cell system can be used in combination with the inhibitory pseudosubstrate peptide to study the involvement of PKC in cellular processes.

Adenosine Triphosphate↗
PubMed1990

High-affinity epidermal growth factor binding is specifically reduced by a monoclonal antibody, and appears necessary for early responses.

We have tested the effects of an mAb directed against the protein core of the extracellular domain of the human EGF receptor (mAb108), on the binding of EGF, and on the early responses of cells to EGF presentation. We used NIH 3T3 cells devoid of murine EGF receptor, transfected with a cDNA encoding the full-length human EGF receptor gene, and fully responsive to EGF. The binding to saturation of mAb108 to the surface of these cells at 4 degrees C and at other temperatures specifically reduced high-affinity binding of EGF, but did not change the dissociation constant or the estimated number of binding sites for low-affinity binding of EGF. The kinetics of EGF binding to the transfected cells were measured to determine the effects of the mAb on the initial rate of EGF binding at 37 degrees C. Interestingly, high-affinity EGF receptor bound EGF with an intrinsic on-rate constant 40-fold higher (9.8 x 10(6) M-1.s-1) than did low-affinity receptor (2.5 x 10(5) M-1.s-1), whereas the off-rate constants, measured at 4 degrees C were similar. Cells treated with the mAb or with phorbol myristate acetate displayed single on-rate constants similar to that for the low-affinity receptors. At low doses of EGF ranging from 0.4 to 1.2 nM, pretreatment of cells with mAb108 inhibited by 50-100% all of the early responses tested, including stimulation of tyrosine-specific phosphorylation of the EGF receptor, turnover of phosphatidyl inositol, elevation of cytoplasmic pH, and release of Ca2+ from intracellular stores. At saturating doses of EGF (20 nM) the inhibition of these early responses by prebinding of mAb108 was overcome. On the basis of these results, we propose that the high-affinity EGF receptors are necessary for EGF receptor signal transduction.

Animals↗
PubMed1989

Ischemic colitis and acalculous necrotizing cholecystitis as rare manifestations of cholesterol emboli in the same patient.

A case is reported of a patient with ischemic colitis and acalculous necrotizing cholecystitis, rare manifestations of cholesterol emboli in one patient. Cholesterol emboli are often encountered at autopsy, suggesting that such abnormalities frequently are missed during life time, as happened initially in our patient. We conclude that multisystemic disease in elderly patients can be due to cholesterol emboli. The sooner the diagnosis is made, the more beneficial prophylactical measures will be.

Aged↗
PubMed1988

201Tl-99mTc subtraction scintigraphy in secondary hyperparathyroidism of chronic renal failure.

In a group of 14 patients with chronic renal failure and secondary hyperparathyroidism, subtraction scintigraphy with 201Tl and 99mTc for parathyroid localisation was performed prior to subtotal parathyroidectomy. Fourteen of 38 (37%) enlarged hyperplastic glands found at first operation corresponded with the hot spots seen on the preoperative scans. Four of five (80%) found at a second operation had also been detected this way preoperatively. Postoperative scans were performed in nine patients. All hot foci seen on the preoperative scans had disappeared. In two patients new hot spots emerged correlating with known residual parathyroid tissue, and also in one patient with recurrent secondary hyperparathyroidism. We conclude that this diagnostic method is of limited value prior to the first neck exploration in secondary hyperparathyroidism of chronic renal failure. However it might be a useful method in the evaluation of patients with signs of persistent or recurrent hyperparathyroidism.

Female↗