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Biomedical subjects

R Schouten

Publications and source records attributed to R Schouten.

At least 19 recordsLinked to original sources
PubMed2006

Re-operation after laparoscopic adjustable gastric banding leads to a further decrease in BMI and obesity-related co-morbidities: results in 33 patients.

BACKGROUND: Laparoscopic adjustable gastric banding (LAGB) is a safe technique with few direct postoperative complications. However, long-term complications such as slippage and pouch dilatation are a well-known problem and re-operations are necessary in a substantial number of patients. In this study, the results of laparoscopic re-operations after LAGB are evaluated. METHODS: 33 patients had a re-operation because of failed LAGB. 29 patients had major re-operation and 4 patients minor re-operation under local anesthesia. The charts of these patients were retrospectively studied. RESULTS: Mean time between the first band placement and re-operation was 28.1 +/- 17.6 months. The cause of band dysfunction was anterior slippage (n=17), band erosion (n=5), band intolerance (n=3), posterior slippage (n=2) and band leakage (n=2). Symptoms of band dysfunction were vomiting (n=16), pyrosis (n=13), nausea (n=8), retrosternal pain (n=11) and regurgitation (n=5). Laparoscopic refixation of the band was performed in 19 patients: the band was replaced in 4 patients while in 1 patient the band was removed; in 3 patients, the laparoscopic procedure was converted to open surgery; 5 patients underwent conversion to a bypass procedure (biliopancreatic diversion in 3 and gastric bypass in 2). There were no direct postoperative complications except for wound infections (n=2). Postoperative follow-up was 100% with a mean period of 34 +/- 19 months. BMI decreased further from 37.5 +/- 6.4 kg/m(2) before re-operation to 33 +/- 7 kg/m(2). Obesity-related co-morbidity also decreased further or completely dissolved. 3 patients (9%) again developed anterior slippage and a second laparoscopic re-operation was necessary. CONCLUSIONS: A laparoscopic re-operation for band-related complications after LAGB is safe and feasible. With band slippage, a laparoscopic refixation was possible in 89%. Re-operation leads to further decrease in BMI and obesity-related co-morbidities.

Adult↗
PubMed2000

Workplace violence and psychiatric practice.

The authors provide an overview of what is known about workplace violence and discuss how to deal with issues of workplace violence that arise in clinical practice. They review myths and facts about workplace violence, including research on prevention. Legal issues relating to the psychiatrist as employer and the Americans with Disability Act are presented. General principles of violence assessment are reviewed and the authors then discuss the psychiatrist as consultant to the workplace and as clinician treating a victim or perpetrator of workplace violence. Three cases illustrate the general principles provided.

Adult↗
PubMed1998

Intracranial haemodynamics during attenuated responses to electroconvulsive therapy in the presence of an intracerebral aneurysm.

OBJECTIVES: This report describes successful anaesthesia and electroconvulsive therapy (ECT) in a patient with an unruptured basilar artery aneurysm. ECT is associated with a hyperdynamic state characterised by arterial hypertension, tachycardia, and considerably increased cerebral blood flow rate and velocity. These responses pose an increased risk for subarachnoid haemorrhage when an intracranial aneurysm coexists. METHODS: A 54 year old woman presented for ECT. She had a 20 year history of major depression which was unresponsive to three different antidepressant drugs. There was also an unruptured 5 mm saccular aneurysm at the basilar tip, which had been documented by cerebral angiography, but its size had remained unchanged for the previous four years. After she declined surgical intervention, she gave informed consent for ECT. During a series of seven ECT sessions middle cerebral artery flow velocity was recorded by a pulsed transcranial Doppler ultrasonography system. She was pretreated with 50 mg oral atenolol daily, continuing up to the day of the last ECT and immediately before each treatment, sodium nitroprusside was infused at a rate of 30 microg/min, to reduce systolic arterial pressure to 90-95 mm Hg. RESULTS: Systolic flow velocity during the awake state ranged from 62-75 cm/s, remaining initially unchanged with sodium nitroprusside infusion. After induction of anaesthesia (0.5 mg/kg methohexitone and 0.9 mg/kg succinylcholine), flow velocities decreased to 39-54 cm/s, reaching maximal values of 90 cm/s (only 20% above baseline) after ECT. These flow velocities recorded post-ECT were considerably below the more than twofold increase recorded when no attenuating drugs were used. Systolic arterial blood pressure reached maximal values of 110-140 mm Hg and heart rate did not exceed 66 bpm. Rapid awakening followed each treatment, no focal or global neurological signs were apparent, and the patient was discharged in remission. CONCLUSION: In a patient with major depression and a coexisting intracerebral saccular aneurysm who was treated with ECT, the combination of beta blockade with atenolol and intravenous infusion of sodium nitroprusside prevented tachycardia and hypertension, and greatly attenuated the expected increase in flow velocity in the middle cerebral artery.

Basilar Artery↗
PubMed1997

A lack of radiation-induced ornithine decarboxylase activity prevents enhanced reactivation of herpes simplex virus and is linked to non-cancer proneness in xeroderma pigmentosum patients.

Patients with xeroderma pigmentosum (XP), a DNA repair disorder, run a large risk of developing skin cancer in sun-exposed areas. Cancer proneness in these patients correlates with a mammalian SOS-like response, "enhanced reactivation (ER) of viruses." Here, we report that radiation-induced activation of the ornithine decarboxylase (ODC) gene, a putative proto-oncogene, is required for this response. Various diploid fibroblast strains derived from a non-cancer-prone subclass of XP patients, which lack the ER response, were irradiated with 2 J/m2 and assessed for gene induction. In these fibroblasts, an absence of induction of ODC by UV-C was observed at the levels of mRNA, protein, and enzyme activity. This lack of induction is quite specific because the genes for fos and collagenase were induced as they were in normal XP cells. The apparent linkage between non-cancer proneness and a lack of ER and ODC induction was confirmed in a fibroblast strain derived from a patient with another DNA repair disorder, trichothiodystrophy, which does not lead to cancer proneness: in these cells, no induction of the ER response nor of ODC occurs after UV-C irradiation. Repair deficiency, however, is not essential because the simultaneous lack of ODC and ER induction after 10 J/m2 UV-C was found in at least one repair-proficient fibroblast. Next, a specific inhibitor of ODC, difluoromethylornithine, at a dose of 10 mM, completely blocked the ER response in cultured normal skin fibroblasts, suggesting that the ODC enzyme is in fact essential for the ER response. Difluoromethylornithine, although it did not affect other processes such as DNA repair, leads to a block in the cell division cycle at the G1-S transition. Interestingly, other blockers of this transition, wortmannin (500 nM) and mimosine (100 mM), also decreased the ER response. Finally, the ER and ODC responses also seem to be linked after treatment with X-irradiation (3 Gy), suggesting that both are part of a general response to DNA damage, at least in human skin fibroblasts. Apart from the abnormal ER and ODC responses, fibroblasts from non-tumor-prone XP patients react in the same way to radiation as do fibroblasts from tumor-prone XP patients with respect to other parameters. Thus, the lack of ODC induction after radiation may help to protect XP patients against skin carcinogenesis.

Cell Cycle↗
PubMed1996

Temperature-sensitive mutant p53 (ala143) interferes transiently with DNA-synthesis and cell-cycle progression in Saos-2 cells.

It has been demonstrated that temperature-sensitive mutant p53 (val-->ala143) inhibits cell-proliferation at the permissive temperature, albeit to a lesser extent than wild-type p53 (Zhang et al.: EMBO J 13:2535-2544, 1994). We have studied its effect on the cell-cycle by dual-parameter flow cytometry, extended pulse-labeling, and pulse-chase experiments. p53ala143 interferes in Saos-2 cells at three levels with cell-cycle progression at permissive temperatures: it caused a G1-arrest, a reduced rate of DNA synthesis during S, and a prolonged G2/M. Strikingly, all these effects are transient. Continued culturing at 32 degrees C resulted in normal cell-cycle progression. Abrogation of the G1-block occurred even in the presence of high p21Waf1 protein levels, a negative cell-cycle regulator of which the expression is induced by wild-type p53.

Bone Neoplasms↗
PubMed1995

Different regulation of p53 stability in UV-irradiated normal and DNA repair deficient human cells.

The stabilization of p53 protein was studied after UV exposure of normal human skin fibroblasts and cells derived from patients suffering from xeroderma pigmentosum (XP) and trichothiodystrophy (TTD). The data show that p53 is transiently stabilized both in UV-irradiated normal and repair deficient cells. However, particularly at later times after UV irradiation, stabilization of p53 persists much longer in repair deficient XP and TTD cells than in normal cells. The stabilization of p53 was found to be dose-dependent in normal and XP cells. These results indicate that unremoved DNA damage could possibly be responsible for the induction of transient stabilization of p53.

3T3 Cells↗
PubMed1995

Comparative effects of esmolol and labetalol to attenuate hyperdynamic states after electroconvulsive therapy.

We studied 18 patients (age range, 53-90 yr) with at least one cardiovascular risk factor who were treated with electroconvulsive therapy (ECT) and compared effects of five pretreatments: no drug; esmolol, 1.3 or 4.4 mg/kg; or labetalol, 0.13 or 0.44 mg/kg. Each patient received all five treatments, during a series of five ECT sessions. Pretreatment was administered as a bolus within 10 s of induction or anesthesia. Doses of methohexital and succinylcholine were constant for the series of treatments and the assignment to no drug or to drug and dose was determined by randomized block design. Measurements of systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR) were recorded during the awake state and 1, 3, 5, and 10 min after the seizure. The deviation of ST segments from baseline was measured by an electrocardiogram (ECG) monitor equipped with ST-segment analysis software. The results (mean +/- SEM) show that without pretreatment, there were significant (P < 0.05) peak increases in SBP and HR (55 +/- 5 mm Hg and 37 +/- 6 bpm, respectively), recorded 1 min after the seizure. Comparable reductions (by approximately 50%) in these peak values were achieved after esmolol (1.3 mg/kg) or labetalol (0.13 mg/kg), and cardiovascular responses were nearly eliminated after the same drugs in doses of 4.4 and 0.44 mg/kg, respectively. The deviation of ST-segment values from baseline in any lead was not measurably influenced by either antihypertensive drug. SBP values were lower after labetalol 10 min after the seizure, but not after esmolol. Asystolic time after the seizure was not significantly longer with either drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1992

Electroconvulsive therapy treatment of depression in a patient with adult GM2 gangliosidosis.

Adult GM2 gangliosidosis is a rare disorder that often presents with both neurological and psychiatric syndromes. Effective treatment of the psychotic and affective symptoms associated with this disorder has been complicated by poor treatment response and the concern that many psychotropic agents may worsen the underlying gangliosidosis. We report the successful use of electroconvulsive therapy for treatment of severe depression in a young man with adult GM2 gangliosidosis.

Adult↗
PubMed1990

Aftermath of the Rogers decision: assessing the costs.

The Massachusetts Supreme Judicial Court's decision in Rogers v. Commissioner is generally regarded as an important right to refuse treatment decision requiring maximum judicial involvement in the treatment of nonconsenting patients. Since courts and legislators in other jurisdictions have looked to Rogers for guidance on right to refuse treatment issues, and since some have adopted it as a model, it is essential for lawmakers to understand the economic realities of the Massachusetts experience and the commitment of resources required by this model. The authors review these realities, suggesting that there are distinct reasons for considering this particular model "cost ineffective" in preserving patients' rights.

Cost-Benefit Analysis↗
PubMed1989

Impaired recovery and mutagenic SOS-like responses in ataxia telangiectasia cells.

Radiosensitive fibroblasts from patients with ataxia telangiectasia (AT) were studied for their proficiency in two putative eukaryotic SOS-like responses, namely the enhanced reactivation (ER) and enhanced mutagenesis of damaged viruses infecting pre-irradiated versus mock-treated cells. A previous report indicated that, unlike normal human cells, a line of AT fibroblasts (AT5BIVA) could not be induced to express ER of damaged parvovirus H-1, a single-stranded DNA virus, by UV- or X-irradiation. In the present study, AT5BIVA fibroblasts were also distinguished from normal cells by the inability of the former to achieve enhanced mutagenesis of damaged H-1 virus upon cell UV-irradiation. In contrast, dose-response and time-course experiments revealed normal levels of ER of Herpes simplex virus 1, a double-stranded DNA virus, in X- or UV-irradiated AT5BIVA cells. Taken together, these data point to a possible deficiency of AT cells in a conditioned mutagenic process that contributes to a greater extent to the recovery of damaged single-stranded than double-stranded DNA. Such a defect may concern the replication of damaged DNA or the generation of signals promoting the latter process and may be related to the lack of radiation-induced delay that is typical of AT cell DNA synthesis.

Ataxia Telangiectasia↗
PubMed1988

Absence of induction of enhanced reactivation of herpes simplex virus in cells from xeroderma pigmentosum patients without skin cancer.

The time course of appearance of enhanced reactivation (ER) and enhanced mutagenesis (EM) of herpes simplex virus type 1 were studied in UV-irradiated stationary cultures of xeroderma pigmentosum (XP) fibroblasts. In some of the XP cells EM followed similar kinetics of appearance as ER. Maximal activities occurred when infection was delayed 1 or 2 days after cell treatment. However, in certain XP cells only induction of the EM response was observed, whereas ER was absent. Interestingly, the latter XP cells had been obtained from patients who had not yet developed skin cancer at the time they were described in the literature, whereas the former XP patients had already developed skin tumors. This suggests that the ER response may somehow be involved in the process of oncogenic transformation. Dose-response studies of ER in XP cells from tumor-bearing patients showed that ER is maximally induced with a UV dose of 40 Jm-2 given to the virus. Normal levels of ER were observed in 14 different normal human skin fibroblasts, indicating that the ER- phenotype does not occur in normal cells or at least more rarely than in XP cells.

Adolescent↗
PubMed1987

[Cells of patients with ataxia telangiectasia show a normal capacity of radio-induced reactivation of damaged HSV-1 virus].

Herpes Simplex Virus (HSV-1) was used to probe the expression of enhanced reactivation (ER) in cells from patients with ataxia telangiectasia (AT). The survival of UV-irradiated HSV-1 was increased as a result of UV- or X-preirradiation of both AT and normal cells. This result contrasts with our previous observation showing that contrary to normal cells AT cells are deficient for ER of a single-stranded DNA parvovirus. A difference between the molecular processes underlying ER of single- and double-stranded DNA viruses might explain these results.

Animals↗
PubMed1985

UVB doses in maintenance psoriasis phototherapy versus solar UVB exposure.

A possible increase in the risk of skin cancer in psoriatic patients treated with long-term maintenance UVB phototherapy was assessed by comparing the cumulative doses of UVB with the amount of UVB received from sunlight by normal healthy people. The biologically-effective UVB dose (termed UVB(EE) ) was measured using polysulphone film and worn as a badge by individuals with either an indoor or an outdoor occupation during 4 summer months of 1983 in The Netherlands (52 degrees N). The calculated mean annual UV-B(EE) doses were 5.9 J/cm2 for persons with an indoor occupation and 134 J/cm2 for those with an outdoor occupation. The UVB(EE) doses received by psoriasis patients during an initial course of phototherapy, as well as during maintenance treatment, were also estimated and gave a mean value of 22 J/cm2. Mean annual amounts of solar UVB(EE) exposure were calculated and compared with the administered doses of UVB(EE) during maintenance phototherapy. A dose-response model is described in order to estimate the increased incidence of non-melanoma skin cancer associated with such therapy. The cumulative incidence among patients who received maintenance phototherapy for several decades was calculated to be a factor of 2.5 to 7.5 higher than the incidence among individuals with an outdoor occupation.

Humans↗