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Biomedical subjects

S Peters

Publications and source records attributed to S Peters.

At least 37 records · Page 2Linked to original sources
PubMed2004

Patients and nurses determine variation in adherence to guidelines at Dutch hospitals more than internists or settings.

AIMS: To measure adherence to recently developed diabetes guidelines at Dutch hospital outpatient clinics and distinguish determinants for variations in care on hospital, internist and patient levels. METHODS: Thirteen general hospitals with 58 internists recruited 1950 diabetic patients. Data were extracted from medical files (n = 1915) and from patient questionnaires (n = 1465). Multilevel logistic regression analysis was performed to explain differences in adherence rates to the guidelines. RESULTS: Adherence to process measures was high, except for the examination of feet, calculation of the body mass index and patient education activities (the mean of 12 process measures was 64%). Adherence to intermediate outcome indicators was moderate. The mean percentage of patients with HbA(1c) < 7.0% was 23%. Adherence variation on a hospital level was very small (0.6-7.9%), on an internist level moderate (0.4-18.8%) and on a patient level high (74.4-98.8%). Adherence to all process measures and most of the intermediate outcome indicators was highest in the patients seen by a diabetes specialist nurse. DISCUSSION: More focus on patient involvement in diabetic care and the contribution of diabetes specialist nurses may be important factors in improving the quality of diabetes care.

Body Mass Index↗
PubMed2004

The effect of immunomodulatory treatment on multiple sclerosis fatigue.

OBJECTIVE: To assess the effects of glatiramer acetate and beta interferon on fatigue in multiple sclerosis. METHODS: Fatigue was measured at baseline and six months using the fatigue impact scale (FIS). Groups (glatiramer acetate and beta interferon) were evaluated for the proportion improved, using Fisher's exact test. Logistic regression analysis assessed the relation between treatment group and improvement and controlled for confounding variables. RESULTS: Six month paired FIS assessments were available for 218 patients (76% female). Ages ranged between 19 and 61 years, with 86% having relapsing-remitting disease. Glatiramer acetate was used by 61% and beta interferon by 39%. At baseline, total FIS and subscale scores were comparable in the two groups. More patients improved on glatiramer acetate than on beta interferon on total FIS (24.8% v 12.9%, p = 0.033; adjusted odds ratio = 2.36, 95% confidence interval 1.03 to 5.42), and on physical (28.6% v 14.1%, p = 0.013) and cognitive subscales (21.1% v 10.6%, p = 0.045). Logistic regression analysis confirmed the association between glatiramer acetate use and improved fatigue, after accounting for baseline group differences. CONCLUSIONS: The odds of reduced multiple sclerosis fatigue were around twice as great with glatiramer acetate treatment as with beta interferon. Confirmation of this result is required.

Adjuvants, Immunologic↗
PubMed2003

A coconut left atrium 23 years after mitral valve replacement for chronic mitral stenosis.

We present the case of a 65 year-old female who was admitted to the hospital because of deterioration of chronic dyspnea. Twenty-three years prior to this admission, mitral valve replacement for chronic mitral stenosis was performed using a Starr-Edwards caged-ball prosthesis. There was severe pulmonary hypertension. On transthoracic echocardiography and on cineradiography, the function of the mitral valve prosthesis was unimpaired. However, cineradiography showed extensive mural calcification of the left atrium; we report this remarkable finding.

Aged↗
PubMed2003

Depressed mood and executive dysfunction in early Parkinson's disease.

OBJECTIVES: Studies on neuropsychological functions in early Parkinson's disease (PD) have reported changes with respect to memory and executive control related to dysfunction of fronto-striatal circuitry. The question has been raised, however, whether these findings are at least partly influenced by depression, which as such can also lead to cognitive impairments that depend on the functional integrity of the prefrontal cortex. MATERIAL AND METHODS: In the present investigation early non-depressed PD patients (NPD), early PD patients with mild depressive symptoms (DPD), patients with primary depression (DEP) and healthy controls (HC) completed a range of neuropsychological tests. RESULTS: Group comparisons revealed impairments of DPD patients in comparison with HC with respect to verbal fluency, short-term memory and concept formation. In addition they showed mild working-memory deficits. CONCLUSIONS: In summary the present results indicate that depressed mood in early PD may exacerbate cognitive impairments. Thus careful assessment of affective variables in PD should be an integral part of the treatment of PD.

Depressive Disorder↗
PubMed2003

[Initial use of risperidone in the treatment of acutely exacerbated schizophrenic patients--an interim analysis].

OBJECTIVE: The effectiveness of atypical antipsychotic agents in the treatment of acute schizophrenic episodes is still a subject of controversial debate. The objective, therefore, was to investigate the efficacy and tolerability of an initial therapy with the atypical antipsychotic agent risperidone in acutely exacerbated patients under the conditions of clinical practice. A sub-analysis was performed to show if highly agitated and aggressive patients may profit from an initial risperidone therapy as well. MATERIAL AND METHODS: In a still ongoing prospective multicentre observational trial, schizophrenic patients with acute exacerbations treated with risperidone within 24 hours of in-patient admission were observed for six weeks. Patients showing a total score of > or = 15 in the items "excitement", "hostility" and "uncooperativeness" of the Positive and Negative Syndrome Scale (PANSS) were defined as highly agitated patients. Evaluation of efficacy was carried out according to a modified PANSS, the Clinical Global Impression (CGI) and the Brief Psychiatric Rating Scale (BPRS). RESULTS: 1,117 patients were evaluated. An improvement of all parameters was shown in the whole study group (51 % males, age 39.8 + 14.3 years, paranoid schizophrenia in 70.1 % of cases) and in particular in the subgroup of highly agitated patients. In these patients (n = 163), a greater improvement of symptoms was observed. Only in 4,1 % of cases was risperidone discontinued because of side effects. At the end of the observation, the mean dosage was 5.1 mg/day in both groups. More than 50 % of the patients were finally treated with a risperidone monotherapy. CONCLUSION: The initial acute treatment with risperidone proves to be effective and safe even for highly agitated schizophrenic patients under the conditions of clinical practice.

Acute Disease↗
PubMed2002

Brain development, song learning and mate choice in birds: a review and experimental test of the "nutritional stress hypothesis".

The nutritional stress hypothesis explains how learned features of song, such as complexity and local dialect structure, can serve as indicators of male quality of interest to females in mate choice. The link between song and quality comes about because the brain structures underlying song learning largely develop during the first few months post-hatching. During this same period, songbirds are likely to be subject to nutritional and other stresses. Only individuals faring well in the face of stress are able to invest the resources in brain development necessary to optimize song learning. Learned features of song thus become reliable indicators of male quality, with reliability maintained by the developmental costs of song. We review the background and assumptions of the nutritional stress hypothesis, and present new experimental data demonstrating an effect of nestling nutrition on nestling growth, brain development, and song learning, providing support for a key prediction of the hypothesis.

Age Factors↗
PubMed2002

[Bilateral carotid dissection. A not to underestimate cause of neurological loss after road accident].

The dissection of the internal carotid artery is a rare complication of acceleration traumas of the upper spine. 30% of these dissections are caused by road accidents and again less than 30% of these occur bilateral as shown here. The symptoms are fronto-temporal and periorbital starting headaches spreading out to the occiput and Horner's syndrome. Complete hemiplegia as in our case is an impressive exception but the doctor in attendance should think of the carotid dissection. The exclusion of this complication is obligatory because treatment and outcome depend on it.The dynamic effects of bilateral carotid dissections may, as shown here, lead to relapsing cerebral infarctions with persisting neurologic deficits up to manifest hemiparesis. But restitution can be accomplished if early diagnosed by DSA and/or MRI. Therapy of choice is early prevention of persisting neurologic deficits using effective dosed heparin and depending on the residual lumen of the vessel oral anticoagulants or platelet antagonists for one year.

Accidents, Traffic↗
PubMed2002

[Pilot study of the effectiveness of combination therapy with reduced dose alteplase and the glycoprotein IIb/IIIa antagonist tirofiban in acute myocardial infarct].

In a pilot study with a total of 43 patients (31 males, 12 females) at a mean age of 64.2 +/- 12.1 years, the efficacy of a combination of a reduced dosage of alteplase (50 mg) and tirofiban with a start infusion of 0.4 microgram/kg/min over half an hour and an infusion rate of 0.10 microgram/kg/min over 12 h (PRISM-PLUS, modified) in four patients and a bolus of 10 micrograms/kg over 3 minutes and an infusion rate of 0.15 microgram/kg/min over 24 h (RESTORE, modified) in 39 patients were tested in acute myocardial infarction with regard to patency of infarct vessel and TIMI flow according to coronary angiography after 60 minutes, 30-day mortality and bleeding complications. The use of tirofiban in the PRISM-PLUS dosage led to an infarct vessel patency of 25% with TIMI III flow in one case. There were no complications in the next 30 days in this group. The use of tirofiban in the RESTORE dosage led to an infarct-vessel patency of 87%, a TIMI III flow in 79%, a 30-day mortality of 2.6% and a slight PCI-associated bleeding complication in one case. The combination of alteplase in a reduced dosage and tirofiban with a single bolus and an infusion rate according to the RESTORE study with satisfactory efficacy and low complication rate seems to be useful in the management of acute myocardial infarction.

Adult↗
PubMed2002

Use of the medial adipofascial flap of the leg for coverage of full-thickness burns exposing the tibial crest.

Bone exposure constitutes a frequent and difficult problem in burn patients. Where free flaps remain indicated in tibial osteomyelitis, a pedicled fascial or adipofascial flap provides an excellent alternative for coverage of simple tibial crest exposure. In fact, the adipofascial tissue of the anteromedial aspect of the leg can be mobilized over the whole length of the tibia. It is vascularized by the saphenous artery and the posterior tibial artery perforators. This pattern of blood supply allows a wide range of use for any size of burn defect in this area. Therefore, this local pedicled flap provides an excellent solution for coverage of the exposed tibia after severe burns.

Burns↗
PubMed2002

Progress of visual dysfunction in Parkinson's disease.

Studies on progression of Parkinson's disease (PD) mainly focus on the nigrostriatal dopaminergic decline, but not on the visual system. We determined progression of (i) disturbed color vision, assessed with the Farnsworth-Munsell 100 Hue test (FMT) and (ii) intensity of PD in 18 patients. Significant differences occurred between (i) initial FMT error scores and follow-up results 3 years later (P=0.002) and analogously (ii) scored intensity of PD (P=0.002). A relation between computed differences of FMT error scores and rated activities of daily living appeared. Deterioration of color vision progresses in PD.

Color Perception↗
PubMed2001

The white spot syndrome virus DNA genome sequence.

White spot syndrome virus (WSSV) is at present a major scourge to worldwide shrimp cultivation. We have determined the entire sequence of the double-stranded, circular DNA genome of WSSV, which contains 292,967 nucleotides encompassing 184 major open reading frames (ORFs). Only 6% of the WSSV ORFs have putative homologues in databases, mainly representing genes encoding enzymes for nucleotide metabolism, DNA replication, and protein modification. The remaining ORFs are mostly unassigned, except for five, which encode structural virion proteins. Unique features of WSSV are the presence of a very long ORF of 18,234 nucleotides, with unknown function, a collagen-like ORF, and nine regions, dispersed along the genome, each containing a variable number of 250-bp tandem repeats. The collective information on WSSV and the phylogenetic analysis on the viral DNA polymerase suggest that WSSV differs profoundly from all presently known viruses and that it is a representative of a new virus family.

Animals↗
PubMed2001

Toward a concept of stretch-coupling in smooth muscle. I. Anatomy of intestinal segmentation and sleeve contractions.

Motility patterns and their structural basis were studied by video analysis, light and electron microscopy on the physiologically distended gut from normal and W/W(v) suckling mice and normal adult mice. Empty or diltiazem-relaxed intestine were used as references. In contrast to conventional primary aldehyde fixation, a brief primary fixation with osmic acid before aldehydes preserved the visible contraction patterns and revealed dynamic increases in the number of peg-and-socket junctions coupling muscle cells mutually and with interstitial cells of Cajal (ICC). In tissue engaged in segmentation, the major increase was in the circular muscle and involved the ICC-DMP (integrated in the circular muscle layer at the site of the deep muscular plexus), whereas the increase during sleeve contractions was in the longitudinal muscle and involved the ICC-AP (located at the site of Auerbach's plexus). The number and distribution of gap junctions were unaffected. Area analysis of cell profiles supported the involvement of circular muscle in segmentation, but longitudinal muscle alone in sleeve contractions. The gut of both normal and W/W(v) sucklings (and adults) contracted during segmentation at frequencies close to reported slow-wave frequencies. In W/W(v) sucklings, ICC-AP were absent whereas ICC-DMP were present in adult configuration. Before Day 8 pp gap junctions were seen only between ICC-DMP. In the sucklings ICC-DMP may be responsible for rapid circumferential coordination and pacemaking of ring contractions. The geometry, organization, and dynamic regulation of peg-and-socket junctions strongly suggest a crucial role in coordination of smooth muscle and pacemakers, probably as stretch sensors, mediating a 'stretch-coupling' in the system.

Animals↗
PubMed2001

[Characteristics and functions of melanin in retinal pigment epithelium].

Melanin granules in the retinal pigment epithelium (RPE) have many important functions which are not yet completely understood. Melanin in the RPE protects the cell from damage caused by oxidative stress. This pigment acts as a free radical sink and diminishes cytotoxic lipid peroxidation. Thus, melanin protects against light toxicity and against cytotoxic effects caused by ocular inflammation. Many enzymes, e.g. superoxide dismutase or carboanhydrase, are only activated in the presence of zinc. Melanin can store zinc and release it when required. The absence of melanin in patients with oculocutaneous albinism is accompanied by photophobia, poor visual acuity and nystagmus. Furthermore melanin is said to protect against damaging lipofuscin accumulation in the RPE. Melanosomes are involved in the lysosomal degradation pathways and possibly take part in the degradation of rod outer segments (ROS) in the RPE.

Albinism, Oculocutaneous↗
PubMed2001

[Adipofascial flaps of the frontal-internal part of the leg: an alternative to free flaps for the repair of skin loss from the knee to the ankle. Report of a clinical experience with 17 cases].

Leg coverage remains a difficult challenge for plastic surgeon, especially in certain areas. Although treatment of osteomyelitis is well established, coverage of bone, tendinous or hardware exposure remain controversial. In these selected cases, adiposofascial pedicled flaps should constitute a interesting solution. The multiples vascular supplies to the adiposofascial tissue of the medial side of the leg constitute de basis of this flap family. These condition allows an extreme adaptability to a wide range of defect with maximal satisfaction.

Dermatologic Surgical Procedures↗
PubMed2001

Prevention of venous thromboembolism in critically ill surgery patients: a cross-sectional study.

BACKGROUND: The risk for venous thromboembolism (VTE) and the risk for bleeding among critically ill surgical patients are both important in the early postoperative period. MATERIALS AND METHODS: To record VTE prophylaxis prescribed for surgical patients in the intensive care unit (ICU) within the first postoperative week. We conducted a prospective observational cross-sectional study of Canadian university affiliated ICUs. RESULTS: Of 29 ICU Directors approached, 28 (96.6%) participated, representing 34 ICUs and 589 ICU beds across Canada. Among 89 patients, surgical procedures were 32 abdominal (36.0%), 19 vascular (21.3%), 10 orthopedic (11.2%), 9 trauma (10.1%), 8 neurologic (9.0%), 5 thoracic (5.6%), 5 gynecologic (5.6%), and 1 for necrotizing fasciitis (1.1%). VTE prophylaxis with unfractionated heparin, low molecular weight heparin, and intermittent pneumatic compression was used in 35 of 89 (39.3%), 8 of 89 (9.0%), and 9 of 89 (10.1%) patients, respectively, whereas 8 of 89 (9.0%) patients were receiving therapeutic anticoagulation. Two methods of VTE prophylaxis were prescribed for 20 of 89 (22.5%) patients. Prophylaxis with unfractionated or low molecular weight heparin was significantly less likely to be prescribed for postoperative ICU patients requiring mechanical ventilation compared with those weaned from mechanical ventilation (odds ratio [OR] 0.36, P =.03). The use of intermittent pneumatic compression devices was significantly associated with current hemorrhage (OR 13.5, P =.02), and risk for future hemorrhage (OR 19.3, P =.001). CONCLUSIONS: VTE prevention for surgical ICU patients within the first postoperative week appear to be individualized, and influenced by current and future risks of thrombosis and bleeding.

Adult↗
PubMed2001

Vascular Parkinsonism: a case report and review of the literature.

Vascular Parkinsonism (VP) is characterised by sudden onset and rapid progression of clinical symptoms, absent or poor response to dopamine substitution therapy, and postural instability with shuffling gait and absence of tremor, making it a clinically distinct entity from idiopathic Parkinson's disease (IPD). Furthermore, it displays certain typical findings in neurological investigations. We report on a patient presenting features of VP associated with an intracerebral lesion not ascribed to VP to date, namely an isolated ischaemic focal lesion located in the left cerebral peduncle between the substantia nigra and nucleus ruber as evidenced by magnetic resonance imaging (MRI). The pathophysiological organic correlate for contralateral extrapyramidal symptoms in this patient may be an interruption of nigro-thalamic projection, interrupting the final subcortical station in the cortic-striato-pallido-nigro-thalamico-cortical loop central to the pathophysiology of parkinsonian syndromes. Non-response t o levodopa therapy could be a consequence of disruption of the cortico-basal ganglia-cortical loop on account of ischaemic destruction of subcortico-cortical axons, the underlying pathology, therefore, not being the result of a loss of nigral dopaminergic neurons or striatal dopamine deficiency pathogonomonic of IPD. To our knowledge, this is the first case of clinically manifest VP to be described with a single lesion in the contralateral cerebral peduncle between the substantia nigra and nucleus ruber, and suggests alternative intracerebral patterns for the distribution of disease-causing lesions in VP, and possibly new pathophysiological explanations for the nature of this disease.

Basal Ganglia Diseases↗
PubMed2001

Resistance to nucleoside analog reverse transcriptase inhibitors mediated by human immunodeficiency virus type 1 p6 protein.

Resistance of human immunodeficiency virus type 1 (HIV-1) to antiretroviral agents results from target gene mutation within the pol gene, which encodes the viral protease, reverse transcriptase (RT), and integrase. We speculated that mutations in genes other that the drug target could lead to drug resistance. For this purpose, the p1-p6(gag)-p6(pol) region of HIV-1, placed immediately upstream of pol, was analyzed. This region has the potential to alter Pol through frameshift regulation (p1), through improved packaging of viral enzymes (p6(Gag)), or by changes in activation of the viral protease (p6(Pol)). Duplication of the proline-rich p6(Gag) PTAP motif, necessary for late viral cycle activities, was identified in plasma virus from 47 of 222 (21.2%) patients treated with nucleoside analog RT inhibitor (NRTI) antiretroviral therapy but was identified very rarely from drug-naïve individuals. Molecular clones carrying a 3-amino-acid duplication, APPAPP (transframe duplication SPTSPT in p6(Pol)), displayed a delay in protein maturation; however, they packaged a 34% excess of RT and exhibited a marked competitive growth advantage in the presence of NRTIs. This phenotype is reminiscent of the inoculum effect described in bacteriology, where a larger input, or a greater infectivity of an organism with a wild-type antimicrobial target, leads to escape from drug pressure and a higher MIC in vitro. Though the mechanism by which the PTAP region participates in viral maturation is not known, duplication of this proline-rich motif could improve assembly and packaging at membrane locations, resulting in the observed phenotype of increased infectivity and drug resistance.

Amino Acid Sequence↗