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S A Duursma

Publications and source records attributed to S A Duursma.

At least 19 recordsLinked to original sources
PubMed1996

[Favorable results of minimally invasive surgery in the treatment of primary hyperparathyroidism].

OBJECTIVE: To study the appropriateness of minimally invasive surgical treatment of primary hyperparathyroidism. DESIGN: Prospective. SETTING: University Hospital Utrecht, the Netherlands. METHOD: In patients with primary hyperparathyroidism, parathyroid adenomas were located preoperatively by means of Doppler assisted ultrasonography and spiral computer tomography. If the results were positive, minimally invasive surgery was performed. RESULTS: Minimally invasive surgery was carried out in 13 out of 15 successive patients with good results (the serum calcium and parathyroid hormone levels returned to normal). Two patients were subjected to conventional neck exploration, also with good results (preoperatively several adenomas were suspected in one, while no adenoma was seen in the other). CONCLUSION: It can be calculated that minimally invasive surgery will probably suffice in 60-70% of the patients with primary hyperparathyroidism, so that conventional neck exploration can be avoided.

Adenoma↗
PubMed1996

Absolute bioavailability of fluoride from disodium monofluorophosphate and enteric-coated sodium fluoride tablets.

OBJECTIVES: The absolute bioavailability and other pharmacokinetic parameters of two fluoride formulations were investigated in 13 healthy volunteers, aged 61-70 years. METHODS: The following formulations were administered, under fasting conditions, in a single-dose three-way cross-over design: tablets of 76 mg disodium monofluoro phosphate (MFP, equivalent to 10.0 mg F- ion), enteric-coated (e.c.) tablets of 25 mg sodium fluoride (NaFor, equivalent of 11.3 mg F- ion), and an isoosmotic aqueous injection solution (4 ml) of 22.1 mg sodium fluoride (NaFiv, equivalent of 10.0 mg F- ion). There was a wash-out period of at least one week between each administration. Blood was sampled before and during a 24-hour period after administration. For F- excretion urine was sampled 48 hours before (baseline) and over the 48 hours after the administration. RESULTS: The mean t1/2 values of the three formulations were 8.3, 8.7 and 8.3 h for MFP, NaFor and NaFiv respectively, and were not significant different. Mean Cmax after MFP was significantly higher than after NaFor [344 vs 142 micrograms.l-1]. Mean tmax for MFP was shorter than for NaFor [1.1 vs 4.6 h]. MFP had significantly higher bioavailability [102.8%] than NaFor [64.2%]. CONCLUSION: The MFP formulation showed higher bioavailability with smaller variation than the NaFor formulation. MFP is preferable, therefore, for fluoride therapy in clinical practice, and changing from NaFor to MFP will require adjustment of the dose.

Administration, Oral↗
PubMed1996

Dementia in resuscitation policy: a prospective study of a psychogeriatric ward in a Dutch general teaching hospital.

Resuscitation decisions during the first 6 weeks were analysed for 97 admissions to a psychogeriatric ward of a general teaching hospital. Seventy-seven patients (79%) had a written 'do not resuscitate' (DNR) order on admission and 74 patients (875) had a written DNR order after 6 weeks. Morbidity was assessed with a pre-arrest morbidity (PAM) index and a modified PAM index (MPI). Dementia influenced the presence of a DNR order, both because lack of effectiveness of CPR and lack of quality of life. Age was related to a DNR order. The MPI was associated with the presence of a written DNR order, while the PAM score failed to reach significance. Six weeks after admission DNR orders were predictable by the four variables of dementia, the use of antidepressants, age and PAM, in that order. The association of the use of antidepressants with the presence of a written DNR order was surprising. The use of antidepressants is not the same as the diagnosis of depression. Because of the design, our results cannot permit any conclusion whether depression acts as an additional factor considered in decision-making in psychogeriatric patients. We suggest that depression and its correlates should be considered in discussions and studies about DNR.

Aged↗
PubMed1995

Effects of methotrexate on human osteoblasts in vitro: modulation by 1,25-dihydroxyvitamin D3.

This study was designed to investigate whether methotrexate (MTX), used in the treatment of rheumatoid arthritis (RA), affects proliferation and differentiation of human osteoblasts in culture. The effects of MTX were assessed by analyzing markers of proliferation and differentiation of human trabecular bone-derived osteoblast-like cells cultured in the presence or absence of 1,25-dihydroxyvitamin D3 (1,25[OH]2D3). Treatment of the osteoblastic cells with MTX resulted in a strong dose-dependent inhibition of cell proliferation with half maximal response at a dose of 30 nM. MTX did not interfere with cellular alkaline phosphatase (AP) activity, the number of cells expressing cytochemical AP, or basal osteocalcin production. Addition of 1,25(OH)2D3 to the cultures caused an enhanced AP expression and osteocalcin production coinciding with a decreased osteoblast proliferation. Coincubation of 1,25(OH)2D3 with MTX in doses > or = 100 nM further inhibited osteoblast growth and induced a significant stimulation of AP expression and activity, and production of osteocalcin above the values reached in the 1,25(OH)2D3 cultures. In conclusion, MTX proved to be a potent inhibitor of osteoblast proliferation but did not affect basal osteoblastic phenotypic expression. In the presence of the osteoblast differentiation-promoter, 1,25(OH)2D3, MTX further inhibited cell growth which was associated with enhanced AP activity and osteocalcin production. Thus, MTX may have profound effects on bone metabolism and remodeling by interfering with bone cell turnover.

Alkaline Phosphatase↗
PubMed1995

Comparison of the action of 17 beta-estradiol and progestins with insulin-like growth factors-I/-II and transforming growth factor-beta 1 on the growth of normal adult human bone-forming cells.

Endogenous growth factors may be involved in the prevention of bone loss by estrogen and progestins in postmenopausal women. The present study was performed to compare the action of estrogen/progestins on bone-derived cells with the effects of exogenously added purified growth factors. Human osteoblast-like (HOB) cells were incubated with 17 beta-estradiol (E2), progesterone (P), dydrogesterone (DD), 20 alpha-dihydroxydydrogesterone (DHD), with and without the growth factors, insulin-like growth factors-I/-II (IGF-I/-II) or transforming growth factor-beta type 1 (TGF-beta 1) for 24 h under serum-free conditions. Cell growth and DNA synthesis were assessed by spectophotometrical analysis of total cell number and immunochemical detection of BrdU incorporation, respectively. Compared with the sex steroids, incubation of the cells with IGF-I or TGF-beta 1 resulted in at least a two-fold increase of total HOB cell numbers. No difference in stimulating HOB growth was observed between IGF-II and the female sex steroids E2 and P. Combining IGF-I/-II or TGF-beta 1 with either E2 or P did not result in a significantly further increase in the human osteoblast-like cell growth. In conclusion, the bone anabolic growth factors, IGF-I and TGF-beta 1, may be more important regulators of osteoblast proliferation than the female sex steroids. An interaction of estrogen/gestagens with the growth factors IGF-I/-II or TGF-beta 1 was not evident from the growth of human bone-forming cells in short-term cultures.

Aged↗
PubMed1994

Euthanasia: the Dutch experience.

Although rules about euthanasia have been developed in the Netherlands, euthanasia has not been legalized. We review the historical aspects of euthanasia, its definition and why no distinction is now made between active and passive euthanasia in the Netherlands. The guidelines for euthanasia, in use in the Utrecht University Hospital, are presented and the result of some studies on euthanasia is discussed. Non-treatment decisions were taken in 17.5% of all deaths in 1990 but only 1.8% of all deaths were the result of euthanasia. Life-terminating acts without explicit and persistent request of the patients occurred in 0.8% of all deaths. The most common reasons for requests for euthanasia were loss of dignity in 57%, pain in 46%, distressing mode of dying in 46% and being dependent on others in 33%. Of all medical decisions concerning the end of life 79% related to patients older than 65 years. The guidelines for euthanasia developed in the Netherlands support both patient and physician in the request for euthanasia.

Aged↗
PubMed1994

The frequency of "do-not-resuscitate" order in aged in-patients: effect of patient- and non-patient-related factors.

OBJECTIVE: The purpose of this study was to examine the effect of patient- and non-patient-related factors (co-morbidity, demographics, and method of surveillance) on the frequency of "do-not-resuscitate" (DNR) orders in aged inpatients. METHODS: On a geriatric ward, during three different periods within 1 year, we used two different methods of data collection (with or without a form) and two different time-frames (prevalence or incidence) in studying the frequency of DNR orders, demographic data and the Pre-Arrest Morbidity (PAM) Index. RESULTS: In a sample of 261 patients the DNR decision was related to patient-related factors, including the PAM score and age. Only 3 patients with a score above 4 had no DNR order and in the group of 142 patients > 83 years 85 (59.9%) had a DNR order, compared to 52 (43.7%) of the 119 patients of 83 years or less (p < 0.05). In contrast, gender and marital status were not related to the presence of a DNR order. The variables PAM score, age, form and time-frame classified 76.6% of the cardiopulmonary resuscitation (CPR) decisions correctly and 71.5% of the DNR decisions correctly. Without attention to the resuscitation decision, the written DNR order frequency decreased significantly from 64-59% to 23%. An explanation for this variance may be the passive process of data collection, a non-patient-related factor. CONCLUSIONS: The DNR decision is related to the PAM index score and age. The variance in DNR decisions is partly related to the method of data collection, a non-patient-related factor in DNR decision-making. Without attention to the DNR/CPR decision, the DNR frequency decreased markedly.

Age Factors↗
PubMed1993

Review: patient-related predictors of cardiopulmonary resuscitation of hospitalized patients.

We reviewed 32 studies to determine whether patient-related factors predict the effectiveness of cardiopulmonary resuscitation (CPR) of hospitalized patients. Limitations of individual studies are described. Single factors and multiple factors, as used in the Pre-arrest Morbidity (PAM) Index, were examined for their ability to predict CPR outcome. Although certain clinical conditions appear to predict CPR survival best, other individual patient-related factors influence the effectiveness of CPR. The PAM Index is superior to single factors in predicting survival after CPR in hospitalized patients, possibly because it is multifactorial. As some studies reveal efficacy of only some of the variables of the PAM Index, a modification of the PAM Index is proposed as an effective tool for predicting CPR outcome. Such a modification may offer geriatricians a practical basis on which some difficult 'do not resuscitate' decisions can be based.

Aged↗
PubMed1993

Resuscitation decisions on a Dutch geriatric ward.

The use of 'do not resuscitate' (DNR) orders was analysed on a Dutch geriatric ward for a 4-month period. Of 148 admissions, 68 (58%) received a written DNR order. The use of DNR orders was significantly influenced by age (> 83 years) and the pre-arrest morbidity (PAM) index. PAM > 4 almost always resulted in a DNR order, and PAM score was the only significant contribution to DNR orders under regression analysis. The issuing of DNR orders by geriatric residents was compared with independent assessments by the other two health-care team members. In 50% of cases where significant comorbidity was zero, at least one of the team suggested a reason for a DNR order, with a mean of 1.9 reasons. The most commonly cited reasons were age (24%), depression (20%) and poor prognosis (18%). To evaluate non-patient-related factors involved in DNR decisions, we studied the involvement of patient or family in the decision, and the extent of agreement between health-care team members. Only 3% of patients and 24% of families were involved in the DNR decision. Disagreement with the residents' decisions was 20% for staff nurses and 17% for consultants. Physicians use factors besides comorbidity to make DNR decisions, and further study of such factors is necessary for the development of standardized DNR policies.

Age Factors↗
PubMed1992

Stimulatory effects of estrogen and progesterone on proliferation and differentiation of normal human osteoblast-like cells in vitro.

Here we report that osteoblast-like cells derived from female and male adult human trabecular bone are able to directly respond to 17 beta-estradiol (E2) and progesterone (P). In short-term (1 day) cultures using serum-free and phenol red-free medium, both steroid hormones were found to stimulate DNA synthesis and growth of the human osteoblast-like cells. P was more potent in stimulating osteoblast growth compared to E2. On the other hand, E2 showed a stronger differentiation-inducing effect as determined by analysis of the number of cells displaying cytochemical alkaline phosphatase (AP) activity, a marker for the mature osteoblast phenotype. Combination of E2 and P resulted in a further increase in DNA synthesis, but did not further affect the number of cells expressing AP activity. In conclusion, female sex steroids may be involved in regulating bone mass in human adults via a direct anabolic action on the bone forming cells.

Alkaline Phosphatase↗
PubMed1992

Epidemiology of hip fractures in The Netherlands: women compared with men.

In this retrospective study the epidemiology of hip fractures in The Netherlands was evaluated. The number of hip fractures over the period 1972-1987 was collected from the Dutch Centre for Health Care Information (Stichting Informatiecentrum voor de Gezondheidszorg, SIG). The demographic data were collected from the Dutch Centre for Statistics (Centraal bureau voor de Statistiek, CBS). The age-adjusted incidence of hip fractures for both women and men 50 years of age and over, increased linearly over the period 1972-1987. There was also a linear rise in the age-adjusted incidence of hip fractures in women and men 65 years of age and over, but the rise in incidence was equal in both sexes. After the age of 50 years women and men showed an equal proportional increase in the age-specific incidence of hip fractures by 5-year age groups. This proportional increase was independent of the calendar year studied during the period 1972-1987. The increase over time in the age-adjusted incidence of hip fractures in inhabitants 50 years of age and over is the result of changes that act well before the age of 50 years, because the proportional increase in the age-specific incidence of these fractures after the age of 50 years did not change over the period studied. The cohort analysis showed that the age-specific incidence of hip fractures in more recently born birth cohorts is higher than that in birth cohorts born long ago. This observation agrees with the other observations.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1992

Is 1 mg of estradiol valerate or 0.625 mg of conjugated estrogens sufficient for all women to prevent menopausal bone loss?

Bone mineral content was measured by dual photon absorptiometry in 35 women who needed estrogen replacement therapy but did not want the addition of progestogens because they did not want regular bleeding. A total of 23 women were treated with estradiol valerate 1 mg per day over a mean period of 3.7 years; 12 women received conjugated estrogens 0.625 mg per day over a mean period of 5.3 years. The mean values of bone mineral content in both groups did not change. In the women on estradiol valerate, 61% had a decrease, and in those on conjugated estrogens, 67% had a decrease in bone mineral content. However, the calculated decrease per year was within the limits of the intraindividual reproducibility of the measurements. A difference between two measurements with a decrease of > 1.0 g hydroxyapatite/year over a period of > 3 years is larger than the limits of the intraindividual reproducibility. A decrease in bone mineral content > 1.0 g hydroxyapatite/year over a mean period of 3.98 years, SD 0.35, was observed in six of 23 (26%) of the women on estradiol valerate with a mean decrease of 5.28 g hydroxyapatite, SD 0.97. Only one of 12 (8%) of the women on conjugated estrogens had a decrease of 6.1 g hydroxyapatite over a period of 5.2 years. Periodic measurement of bone mineral is recommended in women on estrogen replacement therapy with estradiol valerate 1 mg per day or conjugated estrogens 0.625 mg per day for prevention of postmenopausal bone loss.

Adult↗