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Biomedical subjects

J de Lange

Publications and source records attributed to J de Lange.

At least 19 recordsLinked to original sources
PubMed2004

[Treatment of snoring and sleep apnea. Maxillo-mandibular advancement osteotomy].

In this article, a patient is presented who was treated by a maxillo-mandibular advancement osteotomy, in order to increase the volume of the oropharynx as a final treatment of the obstructive sleep apnea syndrome. This syndrome is a common affliction, characterized by excessive daytime sleepiness and unintentionally falling asleep. It can be diagnosed by patient history and polysomnography. Nasal-continuous positive airway pressure is the golden standard of treatment. However, in mild to moderate cases of the syndrome, treatment with a mandibular reposition appliance is also an option. The extraoral device of the first treatment option as well as the intraoral appliance of the second treatment option are demanding patients' compliance. Therefore, research into other treatments is necessary. The initial results of the advancement osteotomy among six patients were very good and in accordance with other literature reports. These results justify further research to clarify the importance of this treatment option of the obstructive sleep apnea syndrome.

Humans↗
PubMed2003

[A mistake in the picture processing procedure?].

A 12-year old boy was referred to an orthodontist. During examination of his dental status a swelling was seen at the right side of his palate. Further examination demonstrated a central giant cell granuloma. This is a rare benign tumor that often causes local destruction of the bone and displacement of teeth. Surgical curettage of these large central giant cell granulomas gives mulilations of the jaws and loss of teeth and tooth germs. Furthermore, it has a high recurrence rate. Therefore, calcitonin was chosen as an alternative therapy.

Calcitonin↗
PubMed2001

The quality of nursing home care: do the opinions of family members change after implementation of emotion-oriented care?

OBJECTIVE: The present study focuses on opinions on the quality of nursing home care of family members of nursing home residents with dementia. Furthermore, we examined whether family members' appreciation of the care increased as a result of the implementation of emotion-oriented care. DESIGN: Randomized clinical trial. INSTRUMENT: An 18-item questionnaire was developed. The following subjects were addressed: communication activities between staff and family members; satisfaction regarding contacts with staff; the extent to which family members can participate in care; the contact that family members experience with the person with dementia, and opinions about the way in which nursing staff treat residents. RESULTS: Most family members already had a positive opinion on the nursing home care prior to the implementation of emotion-oriented care. The most positive assessment concerned the way in which nursing staff treated residents. The lowest scores concerned communication activities between ward staff and family members. Comparison of the first and end measurements showed that in general opinions on the quality of care did not change. STUDY LIMITATIONS: A large number of incomplete questionnaires made it impossible to conduct factor analysis on the classification of the questions in various sections and therefore allowed us only to make statements at the item level. CONCLUSIONS: For the most part family members had a positive opinion on the nursing home care. In general, implementation of emotion-oriented care did not lead to a more positive assessment. Despite the generally accepted notion that involving family members in care is important, family members were regularly treated as outsiders. This demonstrates that there is room for improvement in the communication by nursing home staff with family members (e.g. more frequent contacts and information about the illness).

Activities of Daily Living↗
PubMed1999

Clarithromycin as a single-modality treatment in mycobacterial avium-intracellular infections.

Atypical mycobacterial infections are frequently associated with chronic cervical lymphadenopathy, particularly in children between 1 and 5 years of age. The treatment of choice is regarded to be "optimal" surgical treatment, which often requires wide excision of affected lymph nodes. Although surgical excision is a reliable treatment, it has obvious drawbacks. Because branches of the peripheral facial nerve may be intimately involved in the inflammatory reaction, damage is a potential complication. In addition, keloid scars and wound breakdown are possible complications. Successful drug treatment is hampered by poor susceptibility of the Mycobacterium avium-intracellulare and Mycobacterium scrofulaceum strains to antimicrobial drugs. Reports of results with clarithromycin in the treatment of patients with AIDS who are infected with the M avium complex, however, are promising. The cases of 2 children with infections caused by the M avium complex, resulting in preauricular and cervical lymphadenitis, are described. Treatment with clarithromycin as a monotherapy led to complete healing without recurrence.

Anti-Bacterial Agents↗
PubMed1999

Treatment of central giant cell granuloma of the jaw with calcitonin.

Giant cell granuloma of the jaw is a benign lesion that may cause local destruction of bone and displacement of teeth. The common therapy is curettage or resection, which may be associated with loss of teeth and, in younger patients, loss of dental germs. An alternative treatment has recently been introduced, in which patients receive a daily dose of calcitonin. Four patients who have been treated with calcitonin in various concentrations for at least 1 year are reported. In all patients, complete remission of the giant cell granuloma was observed, without signs of recurrence. The working mechanism of calcitonin is discussed, as are length of treatment and optimal dose.

Adolescent↗
PubMed1999

[New residents of residential care homes for the elderly. The problems of elders with mental disorders].

The article reports on a study involving participants in six projects set up jointly by mental health care facilities and homes for the elderly. The projects were designed to offer protection and guidance in residential homes to older people whose psychiatric problems have rendered them permanently dependent on professional care. The primary focus of the study was on their problems and care needs. Structured interviews were conducted with 136 residents and with their supporting and treating staff. The older people presented an atypical pattern of symptoms. The supporting staff and the treating staff both cited the unsociable, apathetic behaviour of the residents as the most serious problem, followed by emotional problems. Only 37% of the residents were free of cognitive problems, and only 18% had no physical impairments. Although the projects were specifically designed for older people suffering long-term mental instability, more than a quarter of the residents turned out to have had little or no contact with mental health care services. Many had even been admitted to the projects with no prior psychiatric assessment. The study recommends that the projects mobilise more mental health expertise in carrying out needs assessment. To help alleviate the residents' apathy, in-service training programmers for the care staff should focus not on psychopathology alone, but also on ways to create a more stimulating residential and social atmosphere.

Aged↗
PubMed1996

[Nurses' experiences with euthanasia in AIDS patients].

This article describes the experiences of nurses concerning the activities related to euthanasia of patients with aids. The nurses were employed in departments where relatively young, mature people wanted to arrange their own death. Our findings are based on six in-depth interviews with experienced nurses, that are part of a qualitative study into the experiences of nurses in taking leave of terminal patients with aids. The research strategy was based on the Grounded Theory. In order to analyse the experiences of the nurses, four phases were distinguished: set date and time unto application of lethal agent; application unto becoming unconscious; unconsciousness to death; death until transferring the body from the unit. Feelings that occur when taking leave of the patient, if not already taken care of at an earlier instant, play a major role in the phase from application to becoming unconscious. The fact that a deadly agent is being administered can generate feelings of guilt and anxiety. The period from unconsciousness to death is one of waiting. During this period nurses feel alienated and alone. The nurses indicated explicitly that an adequate preparation, evaluation and support are extremely important.

Acquired Immunodeficiency Syndrome↗
PubMed1994

The rate of percutaneous permeation of xylene, measured using the "perfused pig ear" model, is dependent on the effective protein concentration in the perfusing medium.

In order to study the dermal permeation of compounds through the skin, an in vitro model was developed which utilized pig ears perfused with autologous pig blood (de Lange, J., van Eck, P., Elliott, G. R., de Kort, W. L. A. M., and Wolthuis, O. L. (1992). J. Pharmacol. Toxicol. Methods 27, 71-77). In the present article we investigated to what extent the rate of permeation of xylene through pig ear skin is dependent on the perfusion medium used. Pig ears were exposed to xylene (10 cm2 area) for a 4-hr period (30 degrees C, relative humidity of 40-60%) and the perfusate was analyzed for xylene using gas chromatography. The rates of permeation of xylene for whole blood, blood depleted of white blood cells, and a buffer containing 4.5% albumin were similar (+/- 300 ng/min/cm2). The rate of penetration was fivefold higher when pig plasma was used and ninefold lower when albumin was excluded from the buffer. Using the buffer, we found that the rate of permeation of xylene was proportional to flow (constant protein concentration) and protein concentration (constant flow). Our data demonstrate that the measured permeation rate for xylene is, to a large degree, dependent on the effective protein concentration (mg/min) passing through the ear. Differences in this parameter could explain the variations in rates of permeation found using the different perfusion media. To avoid problems associated with the choice of receptor fluid for permeation experiments, we suggest that full blood remains the vehicle of choice, although the practical perfusion period is limited to about 6 hr. If longer perfusion periods are required, then it should be possible to reproduce results obtained with whole blood by choosing an appropriate buffer.

Animals↗
PubMed1994

Analysis of changes in proteoglycan content in murine articular cartilage using image analysis.

The extracellular matrix of articular cartilage consists mainly of type II collagen and large aggregating proteoglycan (aggrecan). During arthritis and other joint diseases, the proteoglycan (PG) level of cartilage matrix is diminished, leading to impairment of normal joint function. A new method is described for measuring the changes in PG content of murine articular cartilage. The method is based on the automated densitometric analysis of patellar cartilage of standard, safranin O-stained sections of whole murine knee joints. It appeared to be possible to measure optical density in parallel layers of articular cartilage with high reproducibility. Approximately 25 sections can be evaluated within 1 h. Measuring a single section 10 times resulted in a coefficient of variation (CV) of 0.1-1.4%. A mean CV of 5-14% was calculated when a group of 18 sections was analyzed in quintuplicate. To validate the procedure, changes in PG content induced by arthritis or by intra-articular injection of TGFbeta-1 were analyzed by the image analysis method, the dimethylmethylene blue (DMB) assay and by visual grading. Although not a quantitive method, the newly developed image analysis method appeared to be more sensitive in detecting significant change in PG content of murine articular cartilage than the DMB method or visual grading. The image analysis method makes it possible to measure changes in PG content of specific areas of articular cartilage with higher sensitivity than the DMB method and eliminating the bias inherent to visual grading by human observers.

Animals↗
PubMed1992

Therapeutic efficacy of HI-6 in soman-poisoned marmoset monkeys.

The therapeutic efficacy of the oxime HI-6 against intoxication with the irreversible cholinesterase (ChE) inhibitor soman was tested in marmoset monkeys. Five out of six marmosets, intoxicated with 5 x LD50 soman and treated immediately with diazepam (0.2 mg.kg-1 iv) and 15 sec later with atropine (0.5 mg.kg-1 im) and HI-6 (50 mg.kg-1 im), survived for more than 24 hr. One of these animals died after 4 days. In the HI-6-treated marmosets blood ChE activity was inhibited at a rate slower than that in three animals treated similarly but with saline instead of HI-6. The latter marmosets died within 8 min after soman. HI-6 achieved its plasma peak 5 min after injection and was eliminated with a t1/2 of about 40 min. In a second experiment similarly treated marmosets were euthanized at 5 min (three saline-treated animals) or at 10 min (three HI-6-treated animals) after the soman intoxication to enable the determination of acetylcholinesterase (AChE) activities in diaphragm and brain tissue. In addition, in these animals blood AChE and butyrylcholine esterase (BuChE) activities were determined. Low AChE activities were encountered in diaphragms and brains. These levels were not significantly different between saline- and HI-6-treated marmosets. In vitro treatment with HI-6 at 40 min after soman still led to an increase of the AChE activity, which was significant in diaphragm, suggesting that postmortem AChE inhibition had occurred. The ratio of AChE to BuChE in blood was significantly enhanced in HI-6-treated animals, indicating that HI-6 preferentially reactivated AChE. It is concluded that (i) HI-6 is an effective treatment against soman poisoning in marmosets and (ii) AChE reactivation or protection by HI-6 contributed to the survival of the animals.

Acetylcholinesterase↗
PubMed1992

The isolated blood-perfused pig ear: an inexpensive and animal-saving model for skin penetration studies.

To overcome most of the disadvantages of current models to investigate percutaneous penetration of drugs or toxic substances, a model is proposed here based on the isolated pig ear, which is obtained at the slaughterhouse, and perfused with oxygenated blood from the same pig. To determine the viability of the preparations, we measured glucose consumption and lactate production as metabolic parameters, Na+ and K+ ions, as well as lactate dehydrogenase activity in blood as markers for cell damage, whereas vasomotor reactivity was assessed by administering noradrenaline and isoxsuprine. After 60 min of equilibration, only insignificant changes in these parameters were observed during the subsequent 3-hr test period (longer periods were not tested). A slight weight increase was noted during the total period 4 hr, presumably due to slight edema formation. On the basis of several types of measurements, such as in vivo blood flow and ear temperature and in vitro glucose metabolism, standard procedures were developed. It is concluded that this technique offers an easy to handle, cost-efficient, and animal-saving model for skin penetration studies that lacks most of the disadvantages of existing models.

Animal Testing Alternatives↗
PubMed1991

Therapy of organophosphate poisoning in the rat by direct effects of oximes unrelated to ChE reactivation.

Isolated rat diaphragm preparations treated with soman or with the irreversible and oxime resistant cholinesterase (ChE) inhibitor S27 showed a considerable recovery of neuromuscular transmission (NMT) during incubation with the (bis)pyridinium oximes HI-6, HGG-12, P2S and obidoxime. In the soman-treated preparations this NMT recovery was predominantly caused by reactivation of acetylcholinesterase (AChE) but in the S27-treated preparations it was caused by a direct (pharmacological) effect unrelated to enzyme reactivation. Atropinized rats were artificially ventilated after injection with 3 x LD50 soman for 3 h and then treated with HI-6, i.e. at a time when oxime reactivation of soman inhibited ChE is no longer possible. Nevertheless, these rats started to breathe spontaneously and 50-60% survived more than 24 h, whereas all control animals (saline instead of HI-6) died within 10 min after artificial ventilation was terminated. In such animals no significant reactivation of ChE activity at various time intervals following HI-6 treatment was found, either in the diaphragms or in the brains. There was a significant amount of NMT (50%) in vitro in diaphragms obtained from these animals. This NMT did not improve in vitro in the presence of HI-6 and was not inhibited by soman administered to the medium. It is concluded that in this case the NMT found was based on synaptic adaptation to the continued inhibition of ChE and that the survival of the animals might be due to a combination of this synaptic adaptation and central direct effects of HI-6.

Animals↗
PubMed1989

In vitro degradation of the stereoisomers of soman in guinea-pig, mouse and human skin.

The fate of the four stereoisomers of soman [C(-)P(+), C(+)P(+), C(+)P(-) and C(-)P(-)] was studied by incubating 10 microM C(+/-)P(+/-)-soman at pH 7.4 and 37 degrees for various periods in the presence or absence of homogenates (1:10 and 1:20 w/v) of guinea-pig, mouse or human skin. The remaining concentrations of the soman isomers were determined gas chromatographically. Similar rates of spontaneous (non-enzymatic) hydrolysis (K = 0.005 min-1) were found for the four isomers of soman. Hydrolysis of the toxic (C(+/-)P(-)-isomers is not accelerated in the presence of the skin homogenates. In contrast, the non-toxic C(+/-)P(+)-isomers are enzymatically hydrolysed. As the amount of proteins present in the homogenates varied the rate constants for enzyme hydrolysis per protein concentration were calculated. Except for the high hydrolysis rate constant of greater than 0.127/min.g.l for C(+)P(+) in human skin, these values were almost similar (0.031-0.045/min.g.l) for the skin homogenates tested. Irreversible binding sites for the four soman-stereoisomers are only found in homogenates of mouse skin; 122-195 pmol soman-isomer are bound per mg protein. After preincubation of mouse homogenate with 10 microM soman during 18 hr at 0-4 degrees no further binding of the isomers was detected. It is concluded that skin of the three species tested does not contain enzymes that degrade the toxic C(+/-)P(-)-isomers of soman, whereas phosphorylphosphatase activity for the C(+/-)P(+)-isomers is present in the skin of all three species. Binding sites for all four soman isomers are only present in mouse skin.

Animals↗