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P M Netten

Publications and source records attributed to P M Netten.

28 records · Page 2Linked to original sources
PubMed1993

A clinical comparison of two laser Doppler instruments. Fiber-optic probe versus integrated probe.

Two instruments for laser Doppler fluxmetry were compared; a diode laser (Diodopp) with a He-Ne gas laser (Periflux Pf1d). Spatial variability during baseline registration and temporal variability during 3 standardized provocation tests (suprasystolic occlusion, tilting and inspiratory gasp) were evaluated in 20 healthy volunteers. The coefficient of variation (= CV) of the registrations on four adjacent places did not show any significant difference between both instruments. The biological zero obtained during 5 minutes vascular occlusion was always zero with the Diodopp and 4 (3-5) (median, [minimum-maximum]) Perfusion Units with the Periflux. The hyperaemic response measured by both instruments was less pronounced during the Diodopp registration (percentage LDF increase 173% (15-350) vs 354% (86-1100), p < 0.001). Although the CV of the LDF parameters obtained by the Diodopp during the standardized provocation tests was almost always lower then with the Periflux, only occasionally the differences reached statistical significance. We concluded that both laser Doppler instruments are of equal value. The reproducibility of the Diodopp is slightly better, but the hyperaemic response after occlusion is registrated in a different way by both instruments.

Adult↗
PubMed1992

An automated computerized method using Finapres for measuring cardiovascular reflexes.

1. The major drawback of the cardiovascular reflex tests used to study autonomic failure is the time involved in calculating the results. To overcome this disadvantage, we have developed an automated computerized program using a FINger Arterial PRESsure instrument for the measurement of beat-to-beat heart rate and blood pressure on a finger. 2. This program calculates heart rate variability during three standardized tests, forced breathing, standing up and the Valsalva manoeuvre, and records blood pressure values in response to standing up and sustained handgrip. The time taken to perform the test and to calculate the results is usually 25 min. 3. The reproducibility of the tests in 21 normal subjects was comparable with the reproducibility obtained with conventional test methods using an ECG and a sphygmomanometer. 4. In addition, we determined the age-dependent normal values of the seven test parameters in 124 subjects aged 20-90 years. 5. Using this program in 10 patients with longstanding (14-50 years) complicated diabetes, in each of them four or more abnormal test results were found.

Adult↗
PubMed1992

Evaluation of infectious diabetic foot complications with indium-111-labeled human nonspecific immunoglobulin G.

Osteomyelitis of the foot is a well-known complication of diabetes mellitus. In this study, the validity of 111In-labeled human nonspecific immunoglobulin G (IgG) scintigraphy was studied in 16 diabetic patients with foot ulcers, gangrene or painful Charcot joints. In all patients, plain radiographs, conventional bone scan images and 111In-IgG images were recorded. The results were verified by histologic examination of surgical specimens in patients who did not respond to antibiotic treatment within 2-3 wk (10 lesions) or long-term clinical follow-up of at least 6-mo (16 lesions). On the bone scans, all seven osteomyelitic foci were detected. However, 19 additional foci not due to osteomyelitis were seen. The absence of true-negative bone scans in this study resulted in a specificity of 0%. On the plain radiographs, four of seven osteomyelitis foci were detected; for 111In-IgG scintigraphy, six of seven (sensitivity 57% and 86%, respectively). Plain radiographs correctly ruled out osteomyelitis in 15 of 19 lesions, 111In-IgG scintigraphy in 16 of 19 (specificity 79% and 84%, respectively). All imaging procedures gave false-positive results in penetrating ulcers over the calcaneus in two patients and in one patient with a Charcot joint, most likely due to recent fractures. A false-negative 111In-IgG study was observed in a patient with severe arterial angiopathy. Accurate estimation of probable osteomyelitis was not possible from the results of soft-tissue cultures, since in only 6 of 12 positive cultures, osteomyelitic foci could be proven. Indium-111-IgG scintigraphy can contribute to adequate evaluation of osteomyelitis in diabetic foot complications because it improves specificity when compared to bone scan and radiographic findings and improves sensitivity in comparison to plain radiographs.

Adult↗
PubMed1991

Sjögren's syndrome complicated by cryoglobulinaemia and acute renal failure.

A patient is described with Sjögren's syndrome and an IgM-kappa gammopathy. With time cryoglobulins, the cause of acute renal failure, could be detected. The kidney biopsy showed a proliferative glomerulonephritis as is frequently seen with mixed cryoglobulinaemia. Plasmapheresis and immunosuppression resulted in long-term improvement of kidney function. The differential diagnosis of acute renal failure of glomerular origin in a patient with Sjögren's syndrome is discussed. This case report illustrates once more the consequences of monoclonal B-cell lymphocyte activation in Sjögren's syndrome.

Acute Kidney Injury↗
PubMed1990

Intravenous magnesium supplementation during cisdiammine-dichloroplatinum administration prevents hypomagnesemia.

Ten patients with disseminated testicular cancer were studied during 3 cycles of 20 mg/m2/day x 5 d CDDP combined with bleomycin and vinblastine or etoposide. Five of the patients (= group A) received 0.4 mmol KCl/kg/day and 0.3 mmol MgCl2/kg/day; the other five (= group B) received only KCl intravenously during the CDDP infusions. In group A no decrease of serum and red blood cell Mg concentration was noted. In group B the serum Mg concentration decreased from 0.84 +/- 0.04 mmol/l to 0.57 +/- 0.10 (p less than 0.001) on day 47, to 0.64 +/- 0.08 (p less than 0.005) on day 50 and to 0.72 +/- 0.02 (p less than 0.05) on day 57. The Mg concentration in the red blood cells decreased, but not significantly in group B. Furthermore, the fractional calcium excretion in group B was significantly lower than in group A during the CDDP infusions.

Adult↗
PubMed1989

Ephedrine improves microcirculation in the diabetic neuropathic foot.

A diabetic patient is described who developed one-sided neuropathic ulceration. Noninvasive microvascular measurements during distant cooling and inspiratory gasp revealed signs of sympathetic denervation. The initially elevated total skin blood flow measured by laser Doppler equipment and decreased capillary perfusion as determined by transcutaneous oxygen tension measurements were both partially restored after treatment with the alpha 1-sympathicomimetic ephedrine. The improvement occurred once more after rechallenge. In conclusion this study further supports the hypothesis of a capillary steal phenomenon caused by extreme vasodilation within sympathetically denervated arteriovenous shunt vessels.

Blood Gas Monitoring, Transcutaneous↗
PubMedDate not supplied

Evaluation of two sympathetic cutaneous vasomotor reflexes using laser Doppler fluxmetry.

Disturbances in sympathetic cutaneous vasomotor reflexes may be of pathogenetic importance in several microvascular problems. Laser Doppler fluxmetry (LDF) enables one to study the influence of sympathetic reflexes on skin blood flow. A matter of concern is the high variability of skin blood flow and its reactivity to sympathetic reflex test resulting in a poor reproducibility. In this study we evaluated two sympathetic stimulation tests, distant cooling and inspiratory gasp, and their influence on LDF-measured skin blood flow of the pulp of the big toe in 63 healthy volunteers. No age or sex dependency of the LDF test results was found. Absolute and relative LDF decrease during distant cooling was highly variable between the subjects (LDF decrease, mean +/-SD: 0.7 +/- 5.3%) compared to an LDF decrease of 46.5 +/- 3.1% during an inspiratory gasp test. The reproducibility, however, was better for the distant cooling test [coefficient of variation (CV): distant cooling: 5.8%, inspiratory gasp test: 35.4%]. With the use of a thermostatically controlled LDF probe holder fixed at a temperature of 36 degrees C, the short-term reproducibility of the two sympathetic vasomotor tests did not improve, probably because of a steady increase in baseline skin blood flow during the test. Surprisingly long-term variability of the percentage LDF decrease during the inspiratory gasp test, performed with the heated LDF probe, was lower compared to the short-term variability (CV 19.2 vs. 39.0%, p < 0.05). In conclusion to study sympathetic skin vasomotor reflexes with LDF, vasoconstriction during the inspiratory gasp test was more uniform compared to the distant cooling test, although the latter was more reproducible. Measuring skin blood flow reactivity with a heated LDF probe (36 degrees C) did not improve reproducibility.

Adult↗
PubMedDate not supplied

Skin vasomotor reflexes during inspiratory gasp: standardization by spirometric control does not improve reproducibility.

Arteriovenous anastomoses (AVA) in skin microcirculation are mediated by the sympathetic stimuli. The inspiratory gasp test (IG test) triggers the sympathetic nervous system, resulting in a decrease in AVA skin blood flow, as measured by laser Doppler fluxmetry (LDF). We studied the reproducibility of the IG test under carefully standardized respiratory conditions. In each of 19 healthy (young) volunteers with a mean skin temperature during the experiment above 28 degrees C 13 IG tests were performed, either under spirometric control or uncontrolled and by using a negative pressure transducer. Starting the IG test end-inspiratory results in the most pronounced absolute LDF decrease [140 PU (70-490)], median (minimum-maximum) as compared to starting end-expiratory [100 PU (40-260)] and during inspiration [110 PU (50-350)], respectively, p < 0.001 and p < 0.001. Inspiration as fast as possible results in a larger absolute LDF decrease [150 PU (40-450)], compared to inspiration in 5 s [120 PU (60-340); p < 0.02] and in 10 s [130 PU (40-350); p < 0.05]. Continuously sucking negative mouth pressure results in a larger LDF decrease [140 PU (30-420)] in comparison with taking one deep breath and holding it for 10 s [110 PU (30-270); p < 0.01]. However, standardization of the IG test did not improve its reproducibility.

Adult↗