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Biomedical subjects

J A Faber

Publications and source records attributed to J A Faber.

At least 37 records · Page 2Linked to original sources
PubMed1994

Symptomatology of patients with oligodontia.

The aims of the present study were: (i) to identify the association of patterns of congenitally missing teeth with combinations of ectodermal symptoms occurring in patients with oligodontia; and (ii) to propose a diagnostic scheme for the general practitioner. For this study 167 patients with oligodontia, both isolated and as part of a syndrome, and 135 healthy controls were interviewed and documented. Chi-square tests, logistic regression and correspondence analysis were used to evaluate and test differences between the groups and associations between the congenitally missing teeth and ectodermal symptoms. No significant differences were found between the control group and the patients with isolated oligodontia with exception of the skin. It could be concluded from the present study that there were no clear associations between congenitally missing teeth, either individually or patterns, and the ectodermal symptoms or combinations of ectodermal symptoms. However, it could be concluded that if the most stable teeth are missing, or if the number of missing teeth is large the patient should be examined carefully for symptoms of ectodermal dysplasia. Using logistic regression a patient could be classified as having isolated oligodontia or oligodontia as part of a syndrome with a specificity and sensitivity of 88.2%.

Abnormalities, Multiple↗
PubMed1994

Recurrent syncope and quadriplegia.

A 72-year-old man had posturally induced syncopal episodes, followed by quadriparesis, coma, and death. Neuroimaging studies supported the clinical diagnosis confirmed by neuropathological findings.

Aged↗
PubMed1993

A novel flow cytometric assay for the quantification of adhesion of subsets within a heterogeneous cell population; analysis of lymphocyte function-associated antigen-1 (LFA-1)-mediated binding of bone marrow-derived primary tumour cells of patients with multiple myeloma.

In a previous study the expression of the adhesion molecule LFA-1 on tumour cells in patients suffering from multiple myeloma (MM) was correlated with growth of the malignant plasma cells in vivo. Here we describe a novel in vitro flow cytometric adhesion assay (FCAA) which, based on scatter and fluorescence properties, was used to analyse the contribution of the LFA-1/intercellular adhesion molecule-1 (ICAM-1) adhesion pathway in the binding of bone marrow (BM)-derived LFA-1-positive primary tumour cells of patients with MM to interferon-gamma (IFN-gamma)-activated, ICAM-1-positive, human venous umbilical endothelial cells (huVEC) in vitro. To validate the FCAA, cells from different myeloma cell lines were labelled with the fluorescent dye CFDA or stained for CD38 expression, and LFA-1-mediated adhesion to IFN-gamma-activated endothelial cells was quantified. Results obtained with the FCAA were compared with a conventional adhesion assay employing 51Cr-labelled cells. Statistical analysis revealed that both assays gave similar results. This allowed analysis of the contribution of LFA-1 to the adhesive potential of malignant plasma cells in bone marrow mononuclear cells (BMMC) from MM patients to IFN-gamma-activated endothelial cells. The results prove that LFA-1 expressed on bone marrow-derived plasma cells from MM patients can be used for cellular adhesion to ICAM-1 expressed on adherent growing cells, and are suggestive for a role of the LFA-1/ICAM-1 adhesion pathway in the pathophysiology of MM. The FCAA described in this study is a generally applicable assay, allowing analysis of the interaction of distinct subpopulations with in vitro grown adherent cells of different origin.

Bone Marrow Cells↗
PubMed1993

Diagnostic value of orthopedic tests in patients with temporomandibular disorders.

For a better definition of diagnostic subgroups of patients with temporomandibular disorders (TMD), clinical orthopedic tests have been developed for the masticatory system, for use together with the commonly used active movement tests and palpation. In the present study, the characteristics and additional diagnostic value of four orthopedic tests--namely, passive opening, the joint play test, compression, and the static pain test--were determined for a patient group, diagnostic subgroups, and a control group. Significant differences among the scores of the tests in the different groups indicated that all six orthopedic tests contributed to the diagnostic process. Because of the close functional relationship of the masticatory system, most information was obtained when patients indicated where pain occurred during the different tests. Logistic regression techniques were used for determination of the relative diagnostic value of each orthopedic test in the diagnostic process. Active movement was the most powerful test for distinguishing the different subgroups. Palpation and passive opening were additionally useful for distinguishing between patients and control subjects and between the subgroups of arthrogenous and myogenous patients. Besides active movement, both compression and the joint play test played a minor role in the distinction of subgroups of arthrogenous patients. It may be concluded that in routine clinical practice, besides history taking and conventional radiography, a functional examination consisting of active movements, passive opening, and palpation provides valuable diagnostic information. In patients with a specific diagnostic problem, one of the other additional tests might be indicated.

Adult↗
PubMed1992

Thrombus regression in deep venous thrombosis. Quantification of spontaneous thrombolysis with duplex scanning.

BACKGROUND: Thrombus regression in heparin-treated, acute deep venous thrombosis of the lower extremity is poorly documented in the literature; different rates of thrombus resolution and recanalization are reported. METHODS AND RESULTS: In a prospective follow-up study, duplex scanning was used to evaluate the thrombus regression in patients with documented acute femoropopliteal thrombosis. Eighty vein segments in 20 legs of 18 patients were subjected to repeat duplex scans at 1, 3, 6, 12, and 26 weeks after diagnosis; 49 segments showed thrombus at diagnosis. The popliteal vein showed the highest thrombus load at diagnosis, followed in descending order by the superficial femoral, profunda femoris, and common femoral vein segments (p less than 0.001). Thrombus regression was significant (p less than 0.001) in all segments and proceeded at an exponential rate that was equal in the different vein segments of the upper leg. Both thrombus resolution and recanalization appeared to be a function of the initial thrombus load and could not be related to individual vein segments. Recanalization was seen in 23 of 31 initially occluded segments and occurred within the first 6 weeks after diagnosis in 20 of 23 segments. Extension of thrombus despite anticoagulant therapy was observed in 15 vein segments and was not related to the initial thrombosis score (p = 0.1) or individual vein segments (p = 0.23). Thrombus extension in seven patients with prethrombotic conditions was not different (p = 0.9) from the other patients. CONCLUSIONS: Duplex scanning is an important noninvasive tool to quantify thrombus regression in acute deep venous thrombosis in detail without unnecessary discomfort to the patient.

Female↗
PubMed1992

Algometry. Measuring pain threshold, method and characteristics in healthy subjects.

A pressure algometer was tested using a specially designed protocol in 28 healthy adult males and females. Two observers examined the pressure threshold (PT) of local tenderness at the joints of the wrists, elbows, knees, ankles, and at the paravertebral tissues. Several characteristics of the instrument were found. There were no significant differences in PT's between the same points on either side of the body (r = 0.738-0.934). A large source of variance was the measurement of one area within short time intervals. No significant differences in means were found between the two observers for the paravertebral points, while significant differences were found at the peripheral joints. Male subjects had significantly higher PT's than females. The PT's of the paravertebral tissues decreased in a cranial direction, while PT's of the peripheral joints showed similar levels. There was no significant influence on observing PT's on different dates or in a different order.

Adult↗
PubMed1991

Myelination as an expression of the functional maturity of the brain.

A prospective cross-sectional study was performed on hydrocephalic infants and children. MRI was used to assess the state of myelination and to quantify the intracranial cerebrospinal fluid (CSF) volume repeatedly in all children. At the same time, neurodevelopmental testing was performed. A positive correlation was found between the progress of myelination and psychomotor development, but there were no significant correlations between CSF volume and myelination or between CSF volume and psychomotor development. This study provides strong evidence in favour of Flechsig's thesis that myelination expresses the functional maturity of the brain. The interdependency of neuronal maturation and progress of myelination are discussed.

Brain↗
PubMed1991

Bandage lenses: collagen shield vs. hydrogel lens.

We compared the behavior of a 70% water content hydrogel lens to a 24-hour collagen shield in 11 healthy volunteers. Corneal swelling was measured by means of ultrasound pachymetry. After 24 hours of continuous wear, mean corneal thickness increased 26.4 microns (4%) with the hydrogel lens and 17.9 microns (3%) with the collagen shield, a difference that was not significant at the P less than 0.05 level. Both the hydrogel lens and the corneal shield were well tolerated. Ocular discomfort was slightly greater with the collagen shield. We assume that this is related to the reduction in visual acuity and subsequent loss of binocular vision with the collagen shield. The development of a fully transparent collagen shield would enhance patient compliance and facilitate assessment of the corneal and intraocular status in eye disease.

Adult↗
PubMed1990

Age-dependent changes in localized proton and phosphorus MR spectroscopy of the brain.

After birth the human brain is subject to major maturational changes, which are associated with changes in the biochemical composition of the brain and brain metabolism. Magnetic resonance (MR) spectroscopy has special capabilities in the analysis of in vivo metabolism. Volume-selective proton and phosphorus MR spectroscopy of the brain was performed on a 1.5-T magnet in 41 healthy children aged 1 month to 16 years. With advancing age, phosphorus spectra revealed a decrease in the ratios of phosphomonoesters (PMEs) to beta-adenosine triphosphate (ATP) and PMEs to phosphocreatine (PCr) and an increase in the ratios of phosphodiesters to beta-ATP, PCr to beta-ATP, and PCr to inorganic phosphate (Pi). No significant changes were observed in Pi/beta-ATP and pH. No changes occurred after the age of 3 years. Proton spectroscopy revealed an increase in the ratios of N-acetylaspartate (NAA) to choline (Ch) and NAA to creatine (Cr) and a decrease in Ch/Cr with increasing age. The most rapid changes were noted during the first 3 years of life, but changes were still observed at the age of 16 years.

Adenosine Triphosphate↗
PubMed1990

Cholecystectomy and colon cancer.

A hospital-based case-control study on the possible relationship between cholecystectomy and colon cancer is described. In all, 569 cases and 1,129 controls were included in the study. Controls were patients who had been admitted either with another malignant disease (lung cancer or breast cancer), or because of benign gastrointestinal diseases. No differences with regard to colon cancer risk were observed between the two control groups. The crude odds ratio (OR) after cholecystectomy for colon cancer was 2.1 [95% CL (confidence limits) = 1.5; 2.9]. No significant difference in risk between males (OR = 2.0; 95% CL = 1.1; 3.6) and females (OR = 2.1; 95% CL = 1.4; 3.2) was found. A significant inverse relationship was found between the relative risk for colon cancer and sublocalization of the colon cancer, the highest relative risk (RR) found proximal in the colon. A decreasing risk with increasing interval between cholecystectomy and date of diagnosis of colon cancer was found. It is hypothesized that the apparent association between cholecystectomy and colon cancer does not reflect a necessary cause-effect relationship, but is rather an epiphenomenon representing a diminished exposure level to other etiologic factors.

Adult↗
PubMed1989

Macrocephalies--a differentiated approach.

We present a clinical study of 43 macrocephalic children with a normal rate of headgrowth. The aims of the study were an evaluation of the usual criteria of macrocephaly and the drafting of a differentiated approach to the investigation of macrocephalics. Firstly, the value of head measurement in evaluating intracranial volume was assessed. As a golden standard for the intracranial volume the volume obtained by means of a CT-scan technique was used. It appeared that only about 30% of the variance of the intracranial volume was determined by the occipito-frontal circumference (OFC). A better estimation of the intracranial volume of the macrocephalic children was obtained by means of the "Utrecht Head Measure", the product of OFC-squared and the head height. Based on length measurements taken from CT-scans, the macrocephalic children were divided into three subgroups: megalencephaly (n = 15), extraventricular obstructive hydrocephalus (n = 5) and communicating hydrocephalus (n = 23). The clinical pictures of the megalencephalic and hydrocephalic children appeared to differ substantially. The megalencephalic subgroup had less neurological symptoms and physical abnormalities and showed a higher intelligence or a more advanced development or both. On the basis of our experience and theoretical considerations guidelines were developed for the assessment of patients with macrocephaly and a normal rate of head growth with a differentiated approach for megalencephalic and hydrocephalic patients.

Brain↗
PubMed1989

Magnetic resonance imaging of the cerebral aqueduct. Signal intensity time curves demonstrated by fast acquisition with multiple excitation (FAME).

Using cardiac-gated fast acquisition with multiple excitation (FAME), time curves of the cerebral aqueduct signals were derived in 19 healthy volunteers and 14 patients. A mean curve of the normal subjects was determined during systole. A relatively stable point of time was found at 270 msec after the R-wave supposed to be the reversal of the flow of cerebral-spinal fluid in the aqueduct. Different curves were noticed in complete aqueductal obstruction (n = 2); in other pathologic states, such as cerebral tumor (n = 3), normal pressure hydrocephalus (n = 3), and brain atrophy (n = 1), no different signal time curves were observed. Parameters such as aqueduct diameter, cerebro-spinal fluid volume and brain compliance are probably other important factors in aqueduct liquor flow.

Adolescent↗
PubMed1988

Paranormal healing and hypertension.

A prospective randomised trial was carried out to see whether paranormal healing by laying on of hands might reduce blood pressure in essential hypertension and whether such an effect might be due to a paranormal, psychological, or placebo factor. Patients were randomised to three treatment groups: paranormal healing by laying on of hands (n = 40), paranormal healing at a distance (n = 37), and no paranormal healing (controls; n = 38). Healing at a distance and no paranormal healing were investigated double blind. Systolic and diastolic blood pressures were significantly reduced in all three groups at week 15 (mean reduction (95% confidence interval) 17.1 (14.0 to 20.2)/8.3 (6.6 to 10.0) mm Hg). Only the successive reductions in diastolic blood pressures among the groups from week to week were significantly different. Each week diastolic pressure was consistently lower (average 1.9 mm Hg) after healing at a distance compared with control, but on paired comparison these differences were not significant. Probably week to week variations among the groups accounted for any differences noted. In this study no treatment was consistently better than another and the data cannot therefore be taken as evidence of a paranormal effect on blood pressure. Probably the fall in blood pressure in all three groups either was caused by the psychosocial approach or was a placebo effect of the trial itself.

Blood Pressure↗
PubMed1988

Effects of cadmium exposure on feeding of freshwater planktonic crustaceans.

1. Effects of cadmium exposure (0.010-0.100 ppm) on food consumption and assimilation rates of crustacean zooplankton from 2 lakes were studied in laboratory using radioisotope (14C) technique. 2. The inhibiting effects were significant 48 hr after Cd-exposure, but not after 20 hr exposure. 3. Daphnia spp. were the most affected cladocerans; copepods, especially the cyclopoids, appeared less sensitive. 4. The decrease in assimilation rates was much more marked than in the consumption rates. 5. The 14C-technique offers quick and sensitive means of studying the effects of heavy metal toxicity.

Animals↗
PubMed1988

Intracranial spaces in childhood macrocephaly: comparison of length measurements and volume calculations.

CT scanning was done to calculate the volume of intracranial spaces in children with the purpose of developing a reliable method of differentiating the various causes of macrocephaly. The technique has been applied to the CT scans of 60 apparently normal children, and the resulting graphs show the normal relationship between intracranial volumes and age from birth to 15 years. The measurements for 25 children with macrocephaly and normal rate of growth of head circumference were then compared with the reference values. It was possible to make accurate differentiations between megalencephaly, extraventricular hydrocephalus and communicating hydrocephalus. The advantage of this technique in relation to length measurements on CT scans is discussed. The authors advocate the estimation of the product of head circumference and head height as a much more reliable indication of normal and deviant head-size than head circumference alone.

Brain↗
PubMed1988

Effect of probing depth and bleeding tendency on the reproducibility of probing depth measurements.

The aim of this study was to determine the influence of the probing depth and the bleeding tendency on the reproducibility of probing depth measurements. Duplicate probing depth and bleeding tendency measurements were performed at 717 interproximal sites in 13 subjects. Analysis indicated that the factor probing depth had a larger effect on the accuracy of probing depth measurements than the factor bleeding tendency.

Adult↗
PubMed1988

Accuracy of repeated single versus averages of repeated duplicates of probing depth measurements.

The present study aims to determine to which extent averages or deepest recordings of repeated duplicates of probing depth measurements may increase the accuracy as compared to repeated single measurements. In total, 1247 sites were recorded in 8 patients with advanced periodontitis. The patients had received initial treatment. Each site was probed 4 times with time intervals of 100 min. The standard deviation of differences between repeated single measurements of 0.97 mm decreased with a factor square root of 2 to 0.69 mm for differences between averages of repeated duplicates of measurements. Differences between the averages and the deepest recordings of repeated duplicates of measurements showed a non-Gaussian distribution. This implies that the type-I error can not be computed on the basis of the standard deviation of the error with the use of parametric statistical analysis. The best estimate for the type-I error is the observed frequency of differences. The type-I error for differences of 3 mm or more between repeated single measurements decreased from 1.5% to 0.9% and 0.2%, when deepest recordings and averages of repeated duplicates of measurements, respectively, were compared.

Adult↗