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Biomedical subjects

J Oosting

Publications and source records attributed to J Oosting.

At least 19 recordsLinked to original sources
PubMed1992

Blood pressure response to routine restorative dental treatment with and without local anesthesia. Continuous noninvasive blood pressure registration with a finger manometer.

A continuous noninvasive blood pressure registration with the Finapres finger manometer was carried out during routine dental treatment, with and without local anesthesia. Forty patients (21 male), 21 to 64 years of age, were studied. Blood pressure was recorded continuously from 10 minutes before dental treatment to 10 minutes after treatment was completed. No local anesthetic was used in 25 patients. In 15 patients (seven men) local anesthetic was used. All patients showed a considerable blood pressure variation. During treatment a significant mean blood pressure increase was registered in the patients treated without local anesthesia. In the patients treated with local anesthesia no significant mean blood pressure changes during dental treatment could be established. However, during the actual administration of the local anesthetic solution a transient blood pressure increase was found, followed by a decrease shortly after removal of the needle from the mouth. After treatment of both groups of patients, a mean blood pressure decrease was established.

Adult↗
PubMed1992

Microwave irradiation and cross-linking of collagen.

In a multifactorial experiment, dermal sheep collagen was treated in diluted glutaraldehyde solutions, 70% ethyl alcohol, Cialit 1:5000, and distilled water for 1, 3 and 5 min, respectively, in combination with microwave irradiation at different temperature settings. The shrinkage temperature indicating the degree of cross-linking achieved was then determined. Treatment in 0.65% glutaraldehyde with microwave irradiation setting for 60 degrees C resulted in the maximum shrinkage temperature within 1 min, whilst at the lower setting of 50 degrees C, the maximum shrinkage temperature for both glutaraldehyde solutions is only reached after 5 min. Neither microwave irradiation by itself, Cialit or ethyl alcohol induce cross-linking of collagen fibres. These findings are relevant for implant studies.

Animals↗
PubMed1992

Recollections of general anaesthesia: a survey of anaesthesiological practice.

In order to identify the factors to which patients attach importance when undergoing general anaesthesia, 678 patients were retrospectively asked about their recollections of previous anaesthetics during routine preoperative screening over a period of 14 months. The most frequently mentioned recollections concerned the post-anaesthetic period, followed by recollections of the induction of anaesthesia. From the post-anaesthetic period, nausea/vomiting and drowsiness were most often cited. The number of anaesthetics previously undergone had no influence on the reports of the two most frequently mentioned complaints. The rate of nausea/vomiting in this series was 21.0%. The number of patients reporting nausea/vomiting following an anaesthetic has not changed over the years. The last 250 patients were asked to assess the quality of their anaesthetics on a 5-point scale. More than a quarter of the patients were not satisfied with the anaesthesia. No correlation was found between the assessment of the anaesthesia and complaints about nausea/vomiting and drowsiness. The possible role of psychological factors in the origin of complaints about anaesthesia is discussed.

Adolescent↗
PubMed1992

Effects of epidural and spinal anesthesia on blood rheology.

This study was designed to compare the influence of epidural and spinal anesthesia on blood viscosity. We studied 22 patients, ASA classification I, who underwent elective knee or ankle arthroscopy and received epidural (n = 11) or spinal (n = 11) anesthesia with plain bupivacaine, and 10 control volunteers, who did not undergo surgery or receive anesthesia. There were significant decreases in hematocrit, plasma viscosity, and whole-blood viscosity at high (70 s-1), medium (0.5 s-1), and low (0.05 s-1) shear rates. The magnitude of changes was similar in all groups but occurred earlier in the control group (between 10 and 30 min) and after spinal administration (between 10 and 30 min) rather than after epidural administration (between 30 and 60 min) of bupivacaine. Only spinal anesthesia was associated with a decrease in erythrocyte deformability. The observed rheologic changes are attributed to hemodilution from the intravenous administration of fluids and the redistribution of fluid in the intravascular and extravascular compartments after sympathetic blockade and to postural changes rather than the effect of bupivacaine on blood elements.

Adult↗
PubMed1992

Pulmonary function and stress response after laparoscopic cholecystectomy: comparison with subcostal incision and influence of thoracic epidural analgesia.

Laparoscopic cholecystectomy (LPC) is increasingly used to treat symptomatic cholelithiasis. We compared the effects of cholecystectomy by subcostal incision to those of LPC on lung function and endocrine metabolic response. The effects of thoracic epidural analgesia for LPC were studied as well. Thirty patients undergoing elective cholecystectomy under general anesthesia were allocated to three study groups: group I, cholecystectomy by subcostal incision; group II, LPC; group III, LPC and epidural analgesia with 0.5% bupivacaine with epinephrine, followed by continuous epidural infusion of 6 mL of 0.5% bupivacaine. Forced vital capacity (FVC), peak expiratory flow, and forced expiratory volume in 1 s were measured with the patients in a half-sitting position. In all groups, sustained decreases in FVC, forced expiratory volume in 1 s, and peak expiratory flow were observed up to 24 h after surgery. Reduction of FVC was significantly more in group I compared with groups II and III (P less than 0.05). The FVC in group I decreased from 3.8 +/- 0.42 (SD) to 1.1 +/- 0.27 L (P less than 0.01), in group II from 3.6 +/- 1.46 to 2.1 +/- 0.94 L (P less than 0.05), and in group III from 3.8 +/- 0.92 to 2.8 +/- 0.90 L (P less than 0.05). In all groups, plasma glucose and cortisol increased after surgery compared with baseline levels (P less than 0.05). At 240 min after surgery, a small but significant decrease of cortisol was measured in group III (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Detecting medical problems in dentistry: a survey of 4,087 patients in The Netherlands.

OBJECTIVES: This study was conducted to determine whether a medical history could be an effective means of detecting medical problems in dental patients. METHODS: A risk-related patient-administered medical questionnaire was completed by 4,087 patients in 47 dental practices. The data collected were summarized by means of descriptive statistics; the number of medical problems and the relationship between these problems and the age of the patient were analyzed. RESULTS: In all, 37.2% of these patients reported at least one medical problem. Hypertension, chronic bronchitis, allergies and medication were the items most frequently mentioned. The frequencies of heart disease, hypertension, endocrinologic and neurologic disorders increased with age, while allergies and chronic obstructive pulmonary disease were evenly distributed over the different age groups. The differences between the health of the patients in the various dental practices were not significant. CONCLUSIONS: On the basis of these results, it can be concluded that taking a medical history by means of a patient-administered questionnaire is an effective method of detecting medical problems of dental patients.

Adolescent↗
PubMed1992

Effects of human epidermal growth factor on endothelial wound healing of human corneas.

Paired human donor corneas (age, 73 +/- 12 yr), preserved in organ culture medium, were used to evaluate the effect of human epidermal growth factor (hEGF) on endothelial wound closure rate (WCR), on morphometric parameters (cell size, shape, and density), and on cell division in the wound area. The endothelium of the corneas was mechanically wounded (area, 4.9 +/- 0.9 mm2). For each pair, one cornea was treated with 10 ng/ml hEGF, while the mate served as control. WCR was assessed by daily staining of the corneas with trypan blue. Morphometric data were obtained after alizarin staining. Mitotic activity was assessed using 3H-thymidine autoradiography. Addition of hEGF significantly increased the WCR compared to the control group. In the closed wound (between 4-9 d), the mean cell size in the center averaged 1940 microns2 in the control group and 1287 microns2 in the hEGF-treated group (P less than 0.01). Fifteen days after wounding, the mean cell sizes averaged 1910 microns2 and 1427 microns2 in the control and hEGF-treated group, respectively (P less than 0.01). All corneas exposed to hEGF had higher endothelial cell densities than the control corneas. In the early stages of wound closure, the cells in the transitional zone in hEGF-treated corneas had a somewhat more elongated shape. However, hEGF did not affect the final cell shape within the closed wound. Autoradiographic results revealed that hEGF accelerated DNA-synthesis, although only to a limited extent. The results indicate that, in human corneas, hEGF promotes endothelial wound healing predominantly by cell migration, at least in corneas from senior donors.

Adult↗
PubMed1991

Pyruvate kinase activity and isozyme composition in normal fibrous tissue and fibroblastic proliferations.

Pyruvate kinase (PK) was studied in 57 fibroblastic and fibrohistiocytic proliferations and normal fibrous tissue (n = 10). The specific activity was significantly increased in malignant tumors (1.67 +/- 0.25) compared with normal tissue (0.26 +/- 0.04; P less than 0.001) and benign proliferations (0.52 +/- 0.05; P less than 0.005). Although an overlap exists between aggressive fibromatosis and the benign group, high values of PK activity are indicative of Grade 2 and 3 malignancy. Significant shifts in isozyme pattern, favoring the expression of K-type subunits were found in tumors with a metastasizing potential and aggressive fibromatosis. These changes in the isozyme pattern of PK in aggressive fibromatosis may act as another argument to place them in the category of malignant fibroblastic tumors.

Adult↗
PubMed1991

Corneal endothelial cell morphology under permanent wear of rigid contact lenses.

The influence of the permanent wear of rigid high Dk-lenses (nominal Dk 71 or 92) with elliptical geometry on the corneal endothelium was assessed. For this purpose the endothelium of 16 patients was compared by specular microscopy before and after the permanent wear. The wearing time of the lenses varied between 7 and 24 months. Computerized morphometric analysis of the photographs revealed that the variability in cell size (polymegathism) and in cell shape (pleomorphism) did not change during the wearing period. It is suggested that this is due to the high gas-permeability and the elliptical geometry of the contact lenses.

Adolescent↗
PubMed1991

Influence of changes in arterial carbon dioxide tension on the electroencephalogram and posterior tibial nerve somatosensory cortical evoked potentials during alfentanil/nitrous oxide anesthesia.

The effects of variation of arterial CO2 tension (PaCO2) on the electroencephalogram (EEG) and posterior tibial nerve somatosensory cortical evoked potentials (PTN-SCEP) during opioid/N2O anesthesia have not been well documented. We studied the effects of hypocapnia (PaCO2 approximately 23 mmHg) and hypercapnia (PaCO2 approximately 50 mmHg) during steady-state alfentanil/N2O anesthesia in 16 patients. EEG and PTN-SCEP were recorded continuously, while PaCO2 was altered in 15-min intervals by varying the inspired CO2 concentration. Hypocapnia caused significant increases in power in the delta, theta, and beta bands (P less than 0.01), with the greatest increase observed in the alpha band. Relative power increased in the alpha band but remained unchanged in the delta, theta, and beta bands. Median frequency and 95% spectral edge frequency were unaltered during hypocapnia. In contrast, hypercapnia caused a significant decrease of power in the alpha and beta bands, whereas delta and theta power remained unchanged. This was reflected in a significant decrease of the 95% spectral edge frequency, from 8.9 (6.7-11.6) to 7.0 (5.6-8.6) Hz. All EEG parameters returned to normal upon restoration of normocapnia. There was a significant negative correlation between power in the alpha band and end-tidal CO2 in all patients (r = 0.47 to -0.89). PTN-SCEP latencies and amplitudes were not significantly different from control values during hypocapnia and hypercapnia. It is concluded that variations in PaCO2 within the limits 20-50 mmHg produce substantial changes in the EEG power spectrum, especially in the alpha band (8-12 Hz), but do not alter PTN-SCEP.

Adult↗
PubMed1991

Piezogenic papules of the feet in healthy children and their possible relation with connective tissue disorders.

Piezogenic papules (PP) are pressure-induced lesions that appear on the heels while bearing weight, due to herniation of fat tissue into the dermis. They are present in the majority of adults. Because of the poor quality of connective tissue in hereditary disorders of connective tissue, such as the Ehlers-Danlos syndrome, it has been suggested that PP would be larger in number and diameter in this group of disorders. If papules are present, they might be painful as well. In view of this hypothesis 322 healthy pupils aged 4 to 13 years from a Dutch primary school were examined in order to study the prevalence and characteristics of piezogenic papules and signs of connective tissue disorders (Ehlers-Danlos) such as hypermobility and skin fragility. Of the 322 children investigated, 72% had one or more PP, the average number being five, with a mean diameter of 3.3 mm. The mean papule diameter increased with age and body weight. None of the papules were painful. Hypermobile joints occurred in 4.3% of the children. Mean body weight was the same in hypermobile and nonhypermobile children of the same age. The numbers of PP were equal in both groups, as was the number of children with and without PP. None of the children showed skin fragility. Our conclusion is that PP are present in the majority of healthy children, and are never painful.

Adolescent↗
PubMed1991

Continuous ambulatory peritoneal dialysis (CAPD) in patients with diabetic nephropathy.

A 3-centre study was done to analyse the results of 70 patients with end-stage renal disease caused by diabetic nephropathy and treated with CAPD. Fifty patients had insulin-dependent diabetes (mean age 42, mean duration of diabetes 24 yr); 20 had non-insulin-dependent diabetes (mean age 61, mean duration 15 yr). Total treatment time was 1563 months and ranged from one to 83 months (median 18). Patient survival was 86% at 1 yr and 33% at 4 yr. Technique survival was 87% and 63%. Cox's multiple hazard regression analysis showed that age above 45 yr (relative risk 2.2), systolic hypertension (2.6) and cardiac disease (2.2) at the start of CAPD were associated with shorter patient survival. Metabolic control was good. Haemoglobin rose during the first 3 months. Plasma creatinine concentration increased with time, probably due to the loss of residual renal function. HbA1c levels were in the normal range for 60% of the patients. Mean hospital stay was 42 days per year, 26 as a consequence of vascular complications and 16 due to peritonitis and catheter-related problems. We conclude that CAPD is a good renal replacement modality for patients with diabetic renal failure. The patient survival is dependent on age, systolic hypertension and cardiac disease at the start of CAPD.

Adult↗
PubMed1990

Coactivation of jaw muscles: recruitment order and level as a function of bite force direction and magnitude.

The aim of this study was to obtain insight into the coactivation behaviour of the jaw muscles under various a priori defined static loading conditions of the mandible. As the masticatory system is mechanically redundant, an infinite number of recruitment patterns is theoretically possible to produce a certain bite force. Using a three-component force transducer and a feedback method, subjects could be instructed to produce a bite force of specific direction and magnitude under simultaneous registration of the EMG activity of anterior and posterior temporal, masseter and digastric muscles on each side. Forces were measured at the second premolars. Vertical, anterior, posterior, lateral and medial force directions were examined; in each direction force levels between 50 N and maximal voluntary force were produced. The results show that for all muscles the bite force-EMG relationship obeys a straight-line fit for forces exceeding 50 N. The relationship varies with bite force direction, except in the case of the digastric muscles. Variation is small for the anterior temporal and large for the posterior temporal and masseter muscles. The relative activation of muscles for a particular force in a particular direction in unique, despite the redundancy.

Adult↗
PubMed1990

Cyclosporin A levels in suction-blister fluid of patients with psoriasis treated systemically.

Oral cyclosporin A (CyA) is highly effective in the treatment of psoriasis. The long-term use is limited by dose-dependent side-effects, and the local concentration of CyA is a determining factor in treatment. The concentration of CyA in suction-blister fluid (SBF) and in whole blood was assessed using a polyclonal radioimmunoassay (RIA). This was carried out in patients with psoriasis following a single dose of CyA and while on adequate oral treatment with the drug. Peak blister fluid levels ranged from 32 to 170 ng/ml, and whole blood levels from 1250 to 2540 ng/ml. CyA trough levels (12 h following taking the drug) in the blister fluid ranged from 22 to 113 ng/ml, and in whole blood from 148 to 935 ng/ml. The trough concentrations in SBF were approximately 10% of whole blood trough levels.

Adult↗
PubMed1990

Activity of glycolytic enzymes and glucose-6-phosphate dehydrogenase in smooth muscle proliferation.

The specific activity of hexokinase, phosphofructokinase, aldolase, enolase, pyruvate kinase and glucose-6-phosphate dehydrogenase was measured in 41 smooth muscle cell tumors: 20 leiomyomas and 21 cases of leiomyosarcoma. Statistical analysis revealed no significant differences in specific activity between normal smooth muscle tissue and the benign and malignant tumors originating from it. Quantification of the isozyme composition of pyruvate kinase showed a significant shift in isozyme pattern towards K-type subunits in leiomyosarcomas as compared to leiomyomas.

Fructose-Bisphosphate Aldolase↗
PubMed1989

Predictors of foetal and neonatal mortality in Curaçao, Netherlands Antilles. A multivariate analysis.

In Curaçao a systematic and comprehensive investigation of numerous factors, potentially associated with an increased risk of foetal and neonatal mortality, was carried out in a 2-year period (1984-85). The inquiry was restricted to singleton births. Data on 205 women who experienced pregnancy loss were compared with those on 913 women who did not sustain foetal or neonatal loss. Data comprised information on maternal characteristics, clinical course of pregnancy and delivery, and neonatal characteristics. Of 130 factors measured, 14 were entered into a multivariate analysis. From the analysis 5 risk factors emerged as significant predictors of mortality: gestational age, birth weight, sex, foetal presentation and congenital anomalies. Factors such as social class, marital status, maternal age and parity were not associated with an increased risk of foetal and neonatal mortality in Curaçao.

Adult↗