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Biomedical subjects

V Fidler

Publications and source records attributed to V Fidler.

At least 55 records · Page 3Linked to original sources
PubMed1994

Hereditary tyrosinemia type I: a new clinical classification with difference in prognosis on dietary treatment.

Hereditary tyrosinemia type I (McKusick 27670) is a heterogeneous disease with poor prognosis, yet there are few reports of the long-term prognosis. It is therefore difficult to decide on the treatment for individual patients. We have conducted an international survey of patients with tyrosinemia type I and examined the probability of survival on dietary treatment and the causes of death in 108 patients with tyrosinemia type I. The survival after the onset of symptoms varied with the age at onset; the earlier the symptoms developed the poorer the outlook. Liver failure and recurrent bleeding (67%), hepatocellular carcinoma (17%) and the porphyria-like syndrome with respiratory failure (10%) were the most common causes of death. The 1- and 2-yr survival probability after the onset of symptoms in patients in whom symptoms developed before 2 mo, between 2 and 6 mo and after 6 mo were 38%/29%, 74%/74% and 96%/96%, respectively. On the basis of these survival rates, a new classification--which is important with respect to choices in treatment--is proposed: very early (onset of symptoms < 2 mo), early (2 to 6 mo) and late presenting form (> 6 mo).

Cause of Death↗
PubMed1993

Walking speed of normal subjects and amputees: aspects of validity of gait analysis.

This study investigated some aspects of the validity of walking speed recording in 15 normal subjects, 16 trans-femoral amputees and 8 knee disarticulation amputees. The variability and test-retest reliability of walking speed and the influence of simultaneous recording of EMG and goniometry on comfortable and fast walking speeds were studied. The variability between sessions was mainly determined by the variance within each session. The variance of speed within sessions while walking with fast speed, was higher when walking without equipment than when walking with equipment. The variances of speed within sessions of the normal subjects were higher than those for both amputee groups. The test-retest reliability, expressed by the intra-class correlation coefficient, was good: between 0.83 and 0.98. The speed when walking without equipment was significantly higher both in normal subjects and amputees than the speed when walking with equipment.

Adolescent↗
PubMed1993

Comparison of gait using a Multiflex foot versus a Quantum foot in knee disarticulation amputees.

The subjective responses and gait patterns of unilateral knee disarticulation amputees wearing prostheses fitted first with the Multiflex foot and then with the Quantum foot were studied. Nine amputees were included in the trial. A questionnaire asked the amputees about their preference for one of the feet. Gait analysis was performed measuring temporal parameters and goniometry of hips, knees and ankles in the sagittal and frontal planes. There was a slight preference for the Quantum foot. Preference seemed not to be related to physical characteristics of the amputees nor to gait parameters. There were no differences in gait as far as the temporal factors were concerned. The main differences in the range of motion of the joints were in the frontal plane: the eversion-inversion movement of the ankle and the adduction-abduction movement of the hip. During walking at comfortable speed with the Multiflex foot the ankle and hip range of motion averaged 2.1 and 3.1 degrees respectively, less than during walking with the Quantum foot.

Adult↗
PubMed1993

Mechanism of biliary lipid secretion in the rat: a role for bile acid-independent bile flow?

Bile acid-induced lipid secretion was compared in unanesthetized normal control and Groningen Yellow Wistar rats during variations in endogenous bile acid output. Groningen Yellow rats express a genetic defect in the biliary secretion of various organic anions. During a 5-hr period after interruption of the enterohepatic circulation, bile acid secretion decreased from 36.4 +/- 1.8 to 1.9 +/- 0.3 mumol per 30 min in normal control rats and from 37.1 +/- 2.8 to 1.8 +/- 0.2 mumol per 30 min in Groningen Yellow rats, respectively (mean +/- S.E.M., n = 5). The relationship between bile acid secretion and bile flow showed similar slopes (normal control, 8.74 +/- 0.44 microliter/mumol and Groningen Yellow rats, 7.71 +/- 0.42 microliter/mumol) but different y-intercepts (normal control, 243 +/- 8 and Groningen Yellow, 127 +/- 4 microliters per 30 min; p < 0.001), corresponding to a 47% reduction of the bile acid-independent fraction of bile flow in Groningen Yellow rats. During the course of the experiment, the ratio of lipids (phospholipids plus cholesterol) to bile acids increased in both strains more than threefold but was permanently higher in Groningen Yellow than in normal control rats (p = 0.035), implying that Groningen Yellow rats continuously secreted more lipid per bile acid. No differences in bile acid pool composition or in bile canalicular membrane composition and fluidity between the two strains were detected. The results indicate that apart from previously demonstrated factors (bile acid concentration, bile acid composition and hydrophilic organic anion concentration in bile), another parameter affects the efficacy of bile acids to induce biliary lipid secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Colonization of burns and the duration of hospital stay of severely burned patients.

In a retrospective study the influence of several factors on the length of hospital stay of severely burned patients (at least 24% total body surface area) has been investigated. The influence of these factors was studied by means of the Cox model survival analysis with time-varying covariates. Seventy-one patients were included in this study. The mean age was 32 years (range 1-82 years), the mean total body surface area burned 40% (range 24-80%) and the mean full-thickness area burned 32% (range 10-70%). The length of hospital stay was positively correlated with the extent of the burned area and with the age of the patient. Wound colonization with Enterobacteriaceae or with a combination of Pseudomonas spp. and Staphylococcus aureus was also associated with a prolonged stay in hospital.

Adolescent↗
PubMed1992

Study of myocardial regional wall motion parameter's accuracy by software perfusion phantom.

Gated perfusion myocardial scintigraphy permits simultaneous evaluation of perfusion as well as regional contractile function of the left ventricle. Fourier analysis of regional myocardial spatial movement with respect to the myocardial geometric centre gives circular amplitude and phase profiles of ventricular contraction, in addition to regional maximum activity that represents an index of perfusion. To introduce such combined perfusion-contraction analysis the accuracy of the indices mentioned above should be evaluated for different doses of radioactivity typically administered to a patient. A mathematical software phantom, consisting of a half circularly profiled ring activity embedded in uniform background activity and noise generated by a Poisson-shaped random number generator, was constructed and used for this purpose. A 64 x 64 matrix and sequence of 16 frames per study was used. The maximum number of counts per pixel ranged from 10 to 100, simulating low count thallium and high count rate Tc-MIBI-gated studies. The relative standard error analysis (R.S.E.) with a 95.5% confidence level for a thallium type of 10 counts per pixel study exceeded 11%, while it reached acceptable values below 3% for studies with 60 and more counts per pixel. These results indicate that high count rate gated technetium-MIBI myocardial perfusion studies could also be used for reliable left ventricular regional wall motion evaluation.

Gated Blood-Pool Imaging↗
PubMed1992

Glomerular macrophage modulation affects mesangial expansion in the rat after renal ablation.

Recent studies have provided evidence for the involvement of macrophages (m phi) in various types of human and experimental glomerular disease. The aim of the present study was to examine the effect of m phi depletion on glomerular injury after 3/4 renal ablation in the rat. This "remnant kidney" model is a widely used experimental model of focal and segmental glomerulosclerosis. Sustained glomerular m phi depletion was induced in remnant kidney rats by a regimen of sublethal triple systemic X-irradiation with shielding of the kidney remnants. Groups of 8 X-irradiated and 8 non-irradiated rats were studied at 5, 9, and 13 weeks after renal ablation. X-irradiated rats showed severe peripheral blood leukopenia at 5 and 9 weeks which had normalized at 13 weeks. The number of remnant glomerular m phi (immunohistochemistry with the monoclonal antibody ED1) in X-irradiated rats at 5 weeks was significantly lower when compared to non-irradiated remnant kidney rats. A rebound effect occurred at 9 and 13 weeks with increased m phi in remnant glomeruli of X-irradiated rats. Light microscopic examination disclosed significantly lower semiquantitative scores for mesangial cellularity and mesangial matrix expansion in remnant glomeruli of X-irradiated rats at 5 weeks when compared to non-irradiated remnant kidney rats. Mesangial matrix expansion had increased in X-irradiated rats at 9 and 13 weeks after ablation coincident with elevated glomerular m phi at these intervals. Multiple linear regression analysis indicated a highly significant contribution of m phi to the best fitting regression model predicting mesangial matrix expansion (multiple r2 = 0.81). In conclusion, these data provide evidence for a contributory role of m phi in the evolution of glomerular injury in the rat after renal ablation.

Animals↗
PubMed1991

Nanosecond fluorescence of tryptophans in cytochrome P-450scc (CYP11A1): effect of substrate binding.

Fluorescence of eight tryptophan residues in cytochrome P-450scc with bound endogenous cholesterol could be fitted with a two component model: a single exponential and a "top-hat" distribution of lifetimes as the second component. The short-lived component (tau 1 about 700 ps) does not change significantly upon binding of substrate (22R-hydroxycholesterol). The parameters of the long-lived component (central lifetime tau m about 3.4 ns) change upon binding of carbon monoxide and substrate. 22R-hydroxycholesterol binding broadens the distribution of the long-lived component; that is the heterogeneity of the Trp environment is increased when this substrate displaces the endogenous cholesterol.

Adrenal Glands↗
PubMed1991

Effect of selective elimination of the oral flora on mucositis in irradiated head and neck cancer patients.

Recently it has been reported that chlorhexidine 0.1% rinsing was not successful in eradication of gram-negative bacilli in patients who have head and neck cancer. These bacilli could play a role in irradiation mucositis. This study reports the effect of lozenges containing 2 mg polymyxin E, 1.8 mg tobramycin, and 10 mg amphotericin B qid on the oropharyngeal flora in 15 irradiated head and neck cancer patients. The results were compared with those of a previous study in two groups of 15 patients comparing chlorhexidine rinsing with placebo. In all patients using lozenges, eradication of gram-negative bacilli and yeasts was achieved within 3 weeks. A significant increase of enterococci was found. Mucositis was significantly reduced compared with the previous two groups. All patients showed erythema only, whereas 80% of both the placebo and chlorhexidine rinsing patients suffered from severe mucositis, with signs of pseudomembranes developing from the third week of conventional irradiation protocol. The effect of selective elimination of gram-negative bacilli from the oropharynx and the prevention of severe mucositis may be explained by the eradication of these bacteria and/or neutralization of salivary endotoxin, released by gram-negative bacilli, mediating the inflammatory processes.

Adolescent↗
PubMed1991

[Comparative animal experiment studies of the effect of exogenous collagen on healing of a deep skin wound].

The high number of available wound dressings as well as the scientific reports about this topic indicates that the problem of an ideal wound dressing material is not jet solved. In the last 30 years lot of scientific reports about collagen as wound covering has been published. The positive effect of collagen by this application on a wound is well-known. We investigated the effect of a collagen sponge on healing of full thickness wound in rats. The animals were divided in two control and two experimental groups. In the control groups there were air exposed wounds as well as wounds covered with paraffin gauze. In the experimental groups the wounds were covered with natural reconstituted collagen sponge as well as with chemically prepared sponge. All results were compared. The wounds with collagen sponge covering healed significantly faster. Also the quality of the wound healing was better in the experimental groups.

Animals↗
PubMed1991

Vibration perception threshold, complaints and sensory examination in diabetic patients.

The vibration perception threshold (VPT) was investigated by means of a biothesiometer among 40 patients with insulin dependent diabetes mellitus. The age as well as the duration of the disease affected the VPT. However, a correlation between the VPT and the rate of metabolic control measured through the glycolysed Hb (HbAlc) could not be demonstrated. In early stages abnormalities were already detectable in the feet. The VPT was elevated in 13 of 20 patients with sensory complaints and in 4 of 20 patients without complaints. Routine neurological examinations such as light touch and pinprick sensation were less sensitive to diagnose neuropathy. In detecting early signs of diabetic neuropathy in an outpatient population the determination of the VPT is a sensitive tool.

Adolescent↗
PubMed1991

Hand-held myometry: reference values.

In thirteen major muscle groups of 50 healthy females and 50 males, aged 20-60 years, maximum voluntary contraction was measured with a hand-held dynamometer. The intrasession variation, the left-right variation, and the fifth and fiftieth centile values were calculated. The ratio of two observations within one session ranged from 0.85 to 1.18 and the ratio of left to right ranged from 0.82 to 1.22 (95% reference limits). In 20 volunteers the repeatability was tested after one week. The ratio of averages of three measurements in two successive weeks ranged from 0.82 to 1.23 (95% reference limits). There were only small differences between muscle groups concerning these ratios. A significant relation with age and weight/Quetelet Index could be demonstrated in some muscle groups. The mean strength of females is approximately two thirds of the strength of males. The data may be useful as reference values in the application of hand-held myometry.

Adult↗
PubMed1991

Computer-assisted analysis of normal second trimester fetal heart rate patterns.

A software package for computer-assisted analysis of antenatal fetal heart rate (FHR) patterns has been commercially available from 1989. Reference ranges for the third trimester of pregnancy have been established. In order to obtain reference values for the second trimester, one hour FHR recordings were made between 20 and 29 weeks gestation in 77 women with uncomplicated pregnancies. There was a significant increase of (medium term) FHR variation and of the number of accelerations from 20 to 29 weeks (r = 0.48, p less than 0.01 and r = 0.34, p less than 0.01 respectively). The lower limit of normal FHR variation (mean--2 SD's) increased from 18 msec at 20 weeks to 28 msec at 28 weeks. Furthermore, a 30 minute recording appeared to be sufficient to obtain a reliable impression of FHR variation. Short term FHR variation, a measure of FHR variation that facilitates the identification of sinusoidal FHR patterns, also increased significantly between 20 and 29 weeks (r = 0.61, p less than 0.01). Delerations (greater than 20 beats/min and greater than or equal to 30 seconds) were present in 54% of the recordings and are a more or less common phenomenon at this age. It is concluded that during the second trimester FHR variation differs considerably from that in the third trimester. This should be taken into account in the interpretation of second trimester FHR records.

Cardiotocography↗
PubMed1991

Determinants of focal and segmental glomerulosclerosis in the rat after renal ablation. Evidence for involvement of macrophages and lipids.

The present study was undertaken to estimate the relative impact of a number of clinicopathologic and glomerular structural changes on severity and composition of focal and segmental glomerular sclerosis (FGS) in rats subjected to renal ablation. Groups of eight 1 1/2-nephrectomized (Nx) and sham-operated (Sh) male Wistar rats were studied at intervals of 2, 4, 8, 12, and 16 weeks. At sacrifice, kidney tissue was embedded in glycolmethacrylate to achieve optimal morphology for light microscopy, immunohistochemistry, and morphometry. FGS lesions were defined by the presence of focal and segmental glomerular scarring and collapse of the glomerular tuft with increased mesangial cellularity (MC), mesangial matrix expansion (MME), and adhesions between the tuft and Bowman's capsule (Adh). The severity of FGS and extent of MC, MME, and Adh was graded seimquantitatively to establish an injury score. The dependence of FGS injury score and of the scores of MC, MME, and Adh on a variety of clinicopathologic and glomerular structural alterations, taking account of possible correlations among them, was estimated with partial correlation and multiple linear regression analysis. The structural parameters included hyalinosis (H, PAS stain), glomerular lipid deposits (GLD, Oil Red O stain), glomerular volume expansion (GVE, morphometry), glomerular cellular proliferation (labeling of S-phase cells by 5 bromo-2'-deoxyuridine, BrdU)--and glomerular influx of macrophages (m phi), T cells, natural killer cells, and granulocytes (immunohistochemistry with mouse monoclonal antibodies). The clinicopathologic variables were urinary protein excretion (UP), fasting serum cholesterol levels (FChol), body weight (BW), total wet kidney weight (KW), heart weight (HW), and systolic blood pressure (SBP). The best fitting linear regression model, explaining 91% of the total variation of the FGS injury score (multiple r2 = 0.91), included UP as the main clinical, and H as the main structural variable. MC was explained best by BrdU incorporation (multiple r2 = 0.77). The optimal regression model describing MME contained the variables H, m phi, and FChol (multiple r2 = 0.84). The extent of Adh formation was optimally described by UP, m phi, and FChol (multiple r2 = .88). In conclusion, although none of these statistically significant associations indicate causal relationships, they identify - in addition to UP, H, and cellular proliferation - FChol as a major clinical determinant and glomerular m phi influx as a major structural alteration associated with FGS in the setting of renal ablation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Chlorhexidine inactivation by saliva.

Chlorhexidine mouth rinsing is commonly used for oral flora reduction. Indigenous microorganisms (viridans streptococci) are significantly suppressed, while "hospital-acquired" gram-negative bacilli are not affected in vivo. To explain the discrepancies between good in vitro and poor in vivo activity of chlorhexidine, minimum bactericidal concentration values for 120 isolates were studied by means of a standard dilution method in fresh whole saliva, broth, and glucose 5%. Both saliva and broth significantly reduced the bactericidal activity of chlorhexidine against all microorganisms tested as compared to glucose 5% (p less than 0.01). Minimum bactericidal concentrations for indigenous flora were significantly lower than the values obtained for the "hospital-acquired" microorganisms (p less than 0.05). These observations of chlorhexidine inactivation by saliva may explain why chlorhexidine mouth rinsing is of limited value in decontaminating the oral cavity.

Analysis of Variance↗
PubMed1990

[Use of phase images in radionuclide ventriculography for topical diagnosis of Wolff-Parkinson-White syndrome and sources of pathologic rhythm of the heart ventricles].

The paper presents the results of the mapping of various types of the Wolff-Parkinson-White syndrome and ventricular arrhythmias by using phase images of radionuclide ventriculograms as compared to 12 leads and electrophysiological studies. Phase images are a highly informative method that supplements an electrophysiological study in the topical diagnosis of abnormal tracts and ventricular arrhythmias.

Adolescent↗