Biomedical subjects

J Hermans

Publications and source records attributed to J Hermans.

At least 271 records · Page 15Linked to original sources

PubMed1994

Pressure sores and pressure-decreasing mattresses: controlled clinical trial.

Pressure sores are a problem, especially in elderly patients. Our study was designed to determine the effectiveness in pressure-sore prevention of a new interface-pressure decreasing mattress. In a prospective randomised controlled clinical trial we tested the Comfortex DeCube mattress (Comfortex, Winona, USA) against our standard hospital mattress in 44 patients with femoral-neck fracture and concomitant high pressure-sore risk score. In addition both groups were treated according to the Dutch consensus protocol for the prevention of pressure sores. On admission and 1 and 2 weeks after admission, pressure sores were graded. The two groups were similar in patient characteristics and pressure-sore risk factors. At 1 week, 25% of the patients nursed on the DeCube mattress and 64% of the patients nursed on the standard mattress had clinically relevant pressure sores (grade 2 or more). At 2 weeks the figures were 24% and 68%, respectively. The maximum score over the several body regions of the pressure-sore grading, measured on a 5-point sale, was significantly different in favour of the DeCube mattress at 1 week (p = 0.0043) and 2 weeks (p = 0.0067) postoperatively. We show that the occurrence of pressure sores and their severity can be significantly reduced when patients at risk are nursed on an interface-pressure decreasing mattress.

Aged↗

PubMed1994

Backbone flexibility and stability of reverse turn conformation in a model system.

Molecular dynamics simulations have been used to study differences in propensity to form a disulfide-bridged turn conformation by peptides with sequence Ac-Cys-Pro-Xaa-Cys-NMe. The calculations were limited to three peptides, with Xaa = Aib, Gly and Val. The experimental differences in propensity (in terms of free energy differences delta delta G degree) were reproduced within 2 kJ/mol. The use of a reduced 1-4 non-bonded interaction potential was tested in this system, but was found to give slightly worse agreement with experiment. The stability of alternate conformations was determined systematically. Type I and II turn conformations of the Aib compound have similar free energy; the Val compound is most stable in a type I turn conformation (by 8 kJ/mol), while the Gly compound is most stable in a type II turn conformation (by 5 kJ/mol). Different backbone conformations were obtained for the valine compound in simulations in solution and in the crystal. It is concluded that turn conformations with psi i+2 near 0, as typically seen in proteins, are stabilized by intramolecular hydrogen bonding in the confined environment. However, when exposed to solvent, hydrogen bonds with water stabilize conformations with larger or smaller values of psi i+2 that are more similar to free energy minima in the isolated, terminally blocked, residue.

Amino Acid Sequence↗

PubMed1994

Lymph node classification systems in cutaneous T-cell lymphoma. Evidence for the utility of the Working Formulation of Non-Hodgkin's Lymphomas for Clinical Usage.

BACKGROUND: This study was undertaken to compare three classification schemes used to evaluate lymph nodes (LN) obtained from patients with cutaneous T-cell lymphoma (CTCL): a modified Rappaport classification, the National Cancer Institute-Veterans Administration (NCI-VA) classification based on the relative numbers of cerebriform cells in the paracortical areas, and the Dutch classification based on the presence of cerebriform cells with large nuclei in mycosis fungoides (MF) and diffuse infiltration by cerebriform cells in Sézary syndrome. METHODS: A study set of 195 LN obtained from patients with CTCL (MF, Sézary syndrome, and nonepidermotropic T-cell lymphomas) and 14 LN from patients with benign dermatoses was reviewed independently by three groups of pathologists familiar with each classification system. RESULTS: Each classification system provided useful prognostic information. However, contrary to prior reports, no significant difference in survival was apparent in patients with uneffaced LN when classified according to the NCI-VA (LN0-2 versus LN3) or Dutch (Gr0-1 versus Gr2) ratings. In addition, all classification systems demonstrated a poor survival time associated with effaced LN. By combining results from the modified Rappaport and Dutch classifications, three prognostic groups could be identified based on cell morphology: a low-grade category with a small cell histologic subtype (median survival time, 40 months); a high-grade immunoblastic subtype (median survival time, 9 months) composed of cells with an oval nucleus containing a large, usually solitary central nucleolus; and an intermediate-grade category composed of all cases without the distinctive small cell and immunoblastic morphologies (median survival time, 26 months). CONCLUSIONS: The authors propose that clearly involved LN in CTCL can be categorized on the basis of cell morphology into prognostic groups analogous to what has been proposed for the Working Formulation for Non-Hodgkin's Lymphomas for Clinical Usage.

Cell Transformation, Neoplastic↗

PubMed1994

Magnetic resonance relaxation times of normal tissue in the course of chemotherapy: a study in patients with bone sarcoma.

To study the effect of chemotherapy on normal fat, skeletal muscle, and bone marrow, T1 and T2 relaxation times were measured in 15 patients with bone sarcoma before and after each cycle of preoperative chemotherapy. A section plane containing the tumor and if possible the nonaffected extremity was imaged with combined multiecho spin echo and inversion recovery pulse sequences. T1 and T2 relaxation times were calculated in the normal-appearing tissues. Although some variation was found in the values in the individual patient and between patients, no systematic changes of relaxation times of fat, muscle, or bone marrow occurred in the course of treatment. We conclude that the chemotherapy used in bone sarcoma has no effect on relaxation times of normal fat, muscle, and bone marrow, and that therefore these tissues may serve as a reference for the signal intensity of tumor.

Adipose Tissue↗

PubMed1994

Monitoring the effect of chemotherapy in Ewing's sarcoma of bone with MR imaging.

Magnetic resonance (MR) imaging was performed in 26 patients with Ewing's sarcoma of bone preceding and following neoadjuvant chemotherapy, to assess tumour response non-invasively prior to surgery. T1- and T2-weighted spin echo images were obtained. Changes including intra- and extramedullary signal intensities, tumour demarcation, tumour volume and the appearance of residual extramedullary tumour were compared with histopathology of the resected specimens. Reduction of tumour volume was significantly higher in good responders. Other single parameters did not correlate with histologic tumour response. However, when several MR parameters summarized in a classification system were combined, a positive correlation with histopathologic response was found. A limited decrease of tumour volume (< 25%) and/or residual soft tissue mass following chemotherapy correlated with a poor response. An inhomogeneous, well-defined cuff of abnormal tissue encircling the bone and/or radiological disappearance of the soft tissue tumour component following chemotherapy correlated with good response. Twenty-three out of 26 patients were correctly classified by MR as good or poor responders. Minimal residual disease (< 10% of the entire tumour volume), observed histologically, could not be identified with MR imaging. Tumour volume reduction and residual extramedullary tumour, rather than changes of signal intensity, are major features for evaluating the response to chemotherapy in Ewing's sarcoma.

Adolescent↗

PubMed1994

Expression of glomerular extracellular matrix components in human diabetic nephropathy: decrease of heparan sulphate in the glomerular basement membrane.

Diabetic nephropathy is characterized by albuminuria which proceeds to overt proteinuria. The highly negatively stained HS side chain of heparan sulphate proteoglycan (HSPG) is a major determinant of the charge-dependent permeability of the GBM. We set out to study the presence of HS and HSPG in the GBM of patients with diabetic nephropathy using newly developed monoclonal antibodies, and to compare HSPG expression to the expression of other previously investigated glomerular extracellular matrix compounds. Immunohistochemically, glomerular extracellular matrix components were analysed in 14 renal biopsies of patients with diabetic nephropathy and compared with those of normal control subjects. Monoclonal antibodies used were: JM403 against the HS side chain of GBM HSPG and JM72 against the HSPG-core protein. Also, a polyclonal antiserum (B31) against human GBM-HSPG-core protein was used. Additionally, antibodies were used against collagen types I, III, IV and against alpha 1 (IV)NC, alpha 3(IV)NC and fibronectin. Staining was scored for intensity and for staining pattern by four independent observers who had no previous knowledge of the sample origin. No glomerular staining was seen for collagen type I. Collagen type III was present in some diabetic nodules. Anti-collagen type IV showed a decreased GBM staining in patients with diabetic nephropathy (p = 0.04). With anti-alpha 1 (IV)NC no changes in GBM staining intensity were observed; with anti-alpha 3 (IV)NC brilliant GBM staining was seen in both groups. Increased mesangial staining (p = 0.003) was seen with anti-collagen type IV in biopsies with nodular lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

Anterior rectocele: assessment with radiographic defecography, dynamic magnetic resonance imaging, and physical examination.

PURPOSE: The aim of this study was to devise a measuring method for an anterior rectocele on standardized defecographies and magnetic resonance images (MRI) to quantify anterior rectocele and to test whether this could substantiate clinical decision making for operative treatment for anterior rectocele. METHODS: Quantitative analysis by the measuring method as proposed was compared with qualitative scores on defecographies and MRI from the same patients. Thirty-eight patients with symptoms compatible with an anterior rectocele were subjected to physical examination in the left decubitis position and supine position and to defecography. Findings on defecography were compared with findings on physical examination. Thirteen patients were examined before and after surgical correction of the anterior rectocele for a total of 51 qualitative and quantitative examinations. The group of operated patients was analyzed for treatment results. Nineteen controls were included. RESULTS: Sixty-six radiographs of 33 defecographies were qualified in three grading classes and quantified with the proposed method by two observers. The mean measured value of the anterior rectocele in the three subjective grading classes is significantly different (P < 0.001). Anterior rectoceles qualified as severe had a measured value of 20 mm or more in 96 percent of the radiographs. Lower gradings were never > 20 mm. On MRI severe anterior rectoceles were not scored and measured values did not correlate with qualitative scores. When findings on physical examination were compared with defecographic measurement, the coefficient of correlation (r) between the radiologic assessment and clinical examination in the left decubitis position is r = 0.87, for the examination in the supine position, r = 0.77. All 15 cases scored as severe anterior rectocele in the left decubitis position had a measured anterior rectocele of > or = 20 mm. In the 13 cases that received surgery, there was a significant reduction of the anterior rectocele (P < 0.001) and clinical improvement. Patients with small or moderate anterior rectocele on physical examination with a size > or = 20 mm on defecography were cured by surgical correction. None of the controls had an anterior rectocele on physical examination or an anterior rectocele > or = 20 mm on defecography. CONCLUSIONS: An anterior rectocele with a size of 20 mm or more corresponds with a qualitative score of "severe" on radiographic defecography. Physical examination for anterior rectocele in the left decubitis position corresponds best with quantitative radiographic assessment and anterior rectocele with a size > or = 20 mm on defecography is pathologic. Patients with complaints compatible with anterior rectocele can be assessed in objective and quantitative terms by radiography and can be successfully surgically treated, even if at physical examination the anterior rectocele is not classified as large, provided that dynamic defecography shows an anterior rectocele of > or = 20 mm. The potential of dynamic MRI with regard to anterior rectoceles presently seems absent.

Adult↗

PubMed1994

Microvascular decompression for trigeminal neuralgia: a critical reappraisal.

The results of posterior fossa explorations for trigeminal neuralgia over the period 1980-1990 in 58 patients and in 59 procedures were studied retrospectively. In 51 procedures vascular compression was treated by microvascular decompression (MVD). In the absence of such a compression, partial sensory rhizotomy (PSR) was performed in 5 cases and only adhesiolysis of thickened arachnoidea in 2 cases. In one additional case the procedure was terminated prematurely due to the development of cerebellar edema. Two months postoperatively a good or fair result was obtained in 80% of the procedures. At long-term follow-up (mean 77.3 months, range 8-146 months), a good or fair result was maintained in 71%. There was no significant difference in outcome between the MVD group and the other procedures, or between the three groups formed according to the type of vascular compression. However, in the group of 10 patients with a history of a procedure affecting the trigeminal ganglion or nerve root the result was worse. In the group of 41 MVD patients rendered free of pain at 2 months postoperatively, 8 patients perceived a recurrence. The annual recurrence rate was calculated to be 2.6%. There was no mortality in this series but the morbidity rate was 22% including 1.7% persistent neurological deficit. Compared to the literature results of percutaneous controlled differential thermocoagulation (PCDT), the recurrence and failure rates in the present series appear to be more or less the same. As neither of the two is an unequivocally more effective treatment, we are of the opinion that the less invasive procedure should be preferred.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Prosthetic valve endocarditis: analysis of risk factors for mortality.

Between 1975 and 1990, 70 episodes of prosthetic valve endocarditis (PVE) were diagnosed in 65 patients at Leiden University Hospital. The overall mortality rate was 27%. Antecedent endocarditis attributable to the same micro-organism (mortality 63%, P = 0.02) and Staphylococcus aureus as the causative micro-organism (mortality 100%, P = 0.001) were significant predictors for mortality. Sex, type and position of the valve and therapy had no significant influence on the mortality. All patients infected with S. aureus died, irrespective of whether they received medical treatment alone or in combination with surgery. None of the patients with streption, endocarditis had abscesses at reoperation; the mortality rate for this group was 14%. Abscess formation, especially in aortic valves, was the most important finding at reoperation and corresponded with a mortality rate of 55%. Ring abscesses occurred equally in patients with mechanical and bioprosthetic valves. Seven of the 15 patients (47%) with significant prosthetic valve dehiscence died. In patients with mitral valve endocarditis, localized dehiscence of the valve was observed. In conclusion a previous endocarditis attributable to the same micro-organism and the causative micro-organism (S. aureus) were important risk factors for mortality due to PVE.

Adolescent↗

PubMed1994

Proliferation profile of benign and premalignant cervical epithelium as established by PCNA staining pattern.

Since immunohistochemical detection of proliferating cell nuclear antigen (PCNA) is closely related to the cell cycle, this method can be used to visualize proliferative activity in paraffin sections of benign and premalignant cervical lesions. This was done in two types of benign lesions, immature and mature metaplasia, and the three types of CIN (I, II, and III). PCNA staining was assessed as heavy, faint, or negative nuclei in the deep, middle, and superficial layers of the epithelium. In the analysis of variance, significant differences between the three layers and between the five groups were found. The PCNA values can be helpful to distinguish immature metaplasia from CIN I. The values for PCNA-positive (heavy+faint) for an individual lesion at the three layers constitute its proliferation profile. The PCNA profiles of the CIN lesions differ fundamentally from the metaplasia profiles. It is conceivable that for an individual CIN lesion, PCNA staining might be prognostically more valuable than its CIN grade.

Cell Division↗

PubMed1994

Evaluation of the effects of radiotherapy on macroprolactinomas using the decline rate of serum prolactin levels as a dynamic parameter.

The effect of radiotherapy (24- > 50 Gy) on serum prolactin levels was studied in 28 patients with macroprolactinomas. All had been treated with surgery and 21 had also received bromocriptine interim therapy. Serum prolactin levels decreased in a log-linear fashion with time, both in the patients who never received bromocriptine and those who were treated with this drug. The decline rate of serum prolactin, which thus represented the effect of radiotherapy, was independent of intercurrent bromocriptine therapy, radiation dose and variables such as pre-radiation prolactin levels, tumour grade and tumour extension. During the course of follow-up (3-24 years) serum prolactin normalized in eight patients (28.6%). It is proposed to use the decline rates as a dynamic parameter to predict normalization time and time required for continuance of dopaminergic drug therapy.

Adult↗

PubMed1994

Serum eosinophil cationic protein (ECP) in chronic asthma. Relationship to spirometry, flow-volume curves, PC20, and exacerbations.

Serum ECP was measured in a double-blind study in relation to spirometry, flow-volume curves, and histamine PC20 (30-s tidal breathing method, normal value > 32 mg ml-1) in 20 chronic asthmatic patients (five male), mean age 48.9 yr (SD 11.0), once a month and at additional visits due to acute exacerbations over a 6-month period. All patients were on maintenance inhaled corticosteroid therapy. Serum ECP was considered elevated at > or = 20 micrograms l-1. ECP showed significant negative correlations with lung function, especially when ECP was elevated (45/143 observations): r = -0.48, -0.48, and -0.49 for respectively FEV1, PEF, and MMEF (all at baseline and as % predicted, P = 0.001), the best correlation being with FEV1/FVC ratio (r = -0.61, P < 0.001). PC20 only had a weak overall correlation with ECP (r = -0.21, P = 0.015). Eosinophilia at > or = 0.400 x 10(9) cells l-1 (38/143 observations) did not show any significant correlations with the lung function variables. The patients were subdivided into three groups according to exacerbations. Group A consisted of seven patients with suspected infectious exacerbations (mean 1.4), group B of six patients with suspected inflammatory exacerbations (mean 3.2), and group C of seven patients who did not experience any symptomatic exacerbations. A significant difference in mean ECP was found between group B and A (33.1 vs. 10.2, P = 0.003). Group B also differed significantly from group A with respect to lung function and PC20, but not to atopy, lung function and PC20 being lower and variability higher in group B. The findings of this study suggest that serum ECP is a sensitive marker of inflammatory airflow obstruction in chronic asthma. Elevated ECP seems to denote patients at risk from inflammatory exacerbations, resulting in practical implications for the therapeutic management of chronic asthma.

Adult↗

PubMed1994

Optimal treatment of adrenocortical carcinoma with mitotane: results in a consecutive series of 96 patients.

Mitotane is considered to be the drug of choice for patients with inoperable, recurrent and metastatic adrenocortical carcinoma, although a favourable effect of this drug on survival has never been documented. We evaluated the efficacy of mitotane treatment of 96 patients with adrenocortical carcinoma followed up in our department between 1959 and 1992. Complete tumour resection was the goal of the initial treatment. Mitotane treatment was classified according to serum trough concentrations on maintenance therapy: low (< 14 mg l-1) or high (> or = 14 mg l-1). Total tumour resection was feasible in 47 patients (49%), and subtotal resection was performed in 37 patients (39%). Patients who underwent total tumour resection survived significantly longer than those who did not (P < 0.001). Adjuvant mitotane therapy (n = 11) did not influence survival after total resection. Sixty-two patients were given mitotane treatment at some time during their illness, only 30 of whom reached high maintenance serum levels. Mitotane treatment with high serum levels had an independently favourable influence on patient survival, using univariate (P < 0.01) and multivariate analysis (P = 0.01). Mitotane treatment resulting in low serum levels was tantamount to not giving mitotane at all. We conclude that mitotane treatment in adrenocortical carcinoma is effective only when high serum levels can be achieved.

Adolescent↗

PubMed1994

Prevalence of depressive symptoms and depressive disorder in primary care patients over 65 years of age.

The aim of this study was to estimate the prevalence of depressive symptoms and depressive disorder (ICHPPC-2-defined) in patients over 65 years of age. A cross-sectional, partly two-phased, study was performed in general practices in The Netherlands. A total of 384 consecutive patients aged 65 and above, 116 men and 268 women were included, both during practice visits and home visits. Depressive symptoms were recorded with the Zung Self-rating Depression Scale, the Geriatric Depression Scale, and with physician ratings. Assessments of depressive disorder were based on an adaptation of interview ratings with the Montgomery Asberg Depression Rating Scale. The proportion of patients considered to have depressive symptoms ranged from 11 to 29% of patients, depending on the self-report instrument and the cut-off point. According to interviews a depressive disorder was estimated to be present in 17%. The high prevalence of depressive symptoms and depressive disorder suggest a higher index of suspicion of depression in elderly general practice patients.

Aged↗

PubMed1994

The short-term effect of intravenous nitroglycerin on haematocrit; an additional benefit in patients with myocardial ischaemia?

Organic nitrates exert their effect by direct inhibition of vascular tone, resulting in decreased myocardial oxygen demand and improved oxygen supply. Less well known is the effect of nitrates on blood rheology. To evaluate the haemodiluting effect of intravenous nitroglycerin we studied 70 consecutive patients admitted to our coronary care unit. The study group consisted of 51 patients with acute chest pain who were treated with nitroglycerin intravenously in a dose between 1 and 5 mg.h-1 during the first 24 h of admission; 19 patients without this treatment were used as controls. In the study group, values of haemoglobin, haematocrit, serum protein and serum albumin, as indirect parameters of haemodilution, all decreased significantly within 24 h, irrespective of the final diagnosis. Similar values were found in the control group. The mean decrease in the haemoglobin value was 0.92 (SD = 0.55) mmol.l-1 vs controls -0.05 (SD = 0.48) mmol.l-1, P < 0.05; the mean decrease in haematocrit was 0.047 (SD = 0.032) vs controls 0.000 (SD = 0.023), P < 0.05. Similar decreases were found in serum protein and albumin values. It is concluded that intravenous nitroglycerin causes a significant decrease in haemoglobin and haematocrit values within 24 h of administration. This altered hemorheologic state may, besides the well known direct vascular effects of nitroglycerin, contribute to the protective effect of nitroglycerin in acute myocardial ischaemia. The effects of nitroglycerin, and the possible mechanisms underlying the decrease in haemoglobin and haematocrit values, will be discussed.

Aged↗

PubMed1994

Suggestions for the optimization of the initial tobramycin dose in adolescent and adult patients with cystic fibrosis.

Clinical pharmacokinetic data of intravenously administered tobramycin in 34 patients with cystic fibrosis (CF) were correlated with patient parameters. Patients began tobramycin therapy with 10 mg/kg/day in three divided doses. Peak and trough serum concentrations were measured. Tobramycin dose was adjusted to a 30 min postdose peak of 10 mg/L and a predose trough of 1 mg/L. Pharmacokinetic data were calculated according to a one-compartment open model and were correlated with clinical data. Tobramycin half-life and total body clearance did not correlate with age, actual body weight, lean body mass, height, or body surface area. Tobramycin volume of distribution correlated with actual body weight (p < 0.02), lean body mass (p < 0.002), height (p < 0.05), and body surface area (p < 0.01), but not with age. The required daily dose after adjustment to a peak serum concentration of 10 mg/L and a trough level of 1 mg/L correlated with lean body mass (p < 0.02) and body surface area (p < 0.05). Based on our findings, the initial daily dose of tobramycin in patients with CF should be calculated by lean body mass rather than actual body weight or body surface area. A formula is presented to calculate the initial daily dose of tobramycin in CF patients who have normal renal function. Monitoring of tobramycin serum levels remains, however, necessary.

Adolescent↗

PubMed1994

The Phadiatop test compared with RAST, with the CAP system; proposal for a third Phadiatop outcome: "inconclusive".

In 19 general practices, blood samples were obtained from 361 patients aged 12 years or older with chronic nasal symptoms. The Phadiatop test and a panel of RASTs to common inhalant allergens were performed on all sera with the recently introduced Pharmacia CAP system. The RAST panel was accepted as the standard. The sensitivity of the Phadiatop was 94% (95% confidence interval (CI): 89-97%), the specificity 98% (95% CI: 95-99%), the positive predictive value 97% (95% CI: 94-99%), and the negative predictive value 95% (95% CI: 91-98%). It is noteworthy that these values are very similar to those found in hospital outpatient departments. It was possible to reduce further the small percentage of false outcomes by replacing the cutoff point of the Phadiatop ratio of 1.00 by the two cutoff points 0.75 and 1.15. This resulted in three possible outcomes: a highly predictive positive outcome, a highly predictive negative outcome, and an "inconclusive" outcome. Alternatively, the cutoff point of 1.00 may be maintained while attaching the annotation "borderline" to all positive or negative Phadiatop outcomes where the Phadiatop ratio is between 0.75 and 1.15. By this simple method, physicians are alerted to the possibility of a false outcome; on the basis of the case history and other clinical findings, they can then decide whether further testing should be done.

Administration, Inhalation↗

PubMed1994

No effect of intramuscular gold therapy on serological parameters of Helicobacter pylori infection in patients with rheumatoid arthritis: a 12 month prospective study.

OBJECTIVES: To assess prospectively the influence of intramuscular gold therapy on Helicobacter pylori serology in patients with rheumatoid arthritis (RA). METHODS: Fifty patients with RA were started on intramuscular gold or chloroquine, as the control group and were followed serologically for H pylori infection for 12 months. RESULTS: Twelve patients treated with gold and eight control patients treated with chloroquine, all with serological evidence for H pylori infection, showed no significant decline of IgA and IgG anti-H pylori antibody levels or serum pepsinogen A and C levels. Total serum IgA and IgG levels declined significantly during gold therapy, while they remained unchanged during chloroquine therapy. CONCLUSIONS: Intramuscular gold therapy in patients with RA does not influence the serological parameters of H pylori infection.

Antibodies, Bacterial↗