Onderzoekingen over de invloed van denervatie van de genitalia op het paringsgedrag bij de rat

De experimenten welke in dit proefschrift beschreven worden, hebben tot doel inzicht te verkrijgen in de gevolgen van denervatie van de geslachtsorganen voor het paringsgedrag bij de rat. Daar de autonome innervatie van de geslachtsorganen hierbij belangrijk is, zal allereerst op schematische wijze de anatomie van het perifere autonome zenuwstelsel zoals dat bij zoogdieren georganiseerd is, besproken worden. Een uitvoeriger beschrijving van de anatomie en functie van het autonome zenuwstelsel is gegeven door Kunz (1953) en Piek (1970). Daarop volgt een beschrijving van twee belangrijke componenten van het paringsgedrag van manlijke zoogdieren, namelijk de erectie en de ejaculatie. Tenslotte zal het paringsgedrag van de rat aan de orde komen

Late seizures following a first symptomatic brain infarct are related to large infarcts involving the posterior area around the lateral sulcus

Controversies exist concerning factors that contribute to the occurrence of epileptic seizures after stroke. Therefore, we studied prospectively the occurrence of seizures in 322 patients with a first-ever CT-confirmed symptomatic territorial brain infarct involving the cortex. We also studied potential risk factors for seizures, and gave special attention to cortical infarct location. Fifty-four patients developed post-stroke seizures. We distinguished between early- and late-onset seizures, occurring within two weeks following stroke-onset, or later than two weeks, respectively. We found that patients of 65 years or older with a cardioembolic brain infarct involving the middle temporal or post-central gyrus, had an almost eight times increased risk of early-onset seizures, whereas patients with a large brain infarct involving the supramarginal or superior temporal gyrus, had a five times increased risk of late-onset seizures. We conclude that risk factors and epileptogenic cortical areas for post brain infarct seizures can be identified, which however, differ between early- and late-onset seizures. These two seizure types may also differ in terms of seizure mechanism. Our findings may influence the decision on prophylactic treatment with antiepileptic drugs in stroke patients

Comparison of seven sets of criteria used for the diagnosis of vascular dementia

At least seven different sets of criteria are commonly used for the diagnosis of vascular dementia (VaD). These are the ischemic scales (IS) of Hachinski, Rosen and Loeb, the criteria from the DSM-III-R, those outlined by Erkinjuntti et al., the State of California Alzheimer''s Disease Diagnostic and Treatment Centers (ADDTC) and the international workgroup of the American National Institute of Neurological Disorders and Stroke (NINDS) and the European ''Association Internationale pour la Recherche et l''Enseignement en Neurosciences''. To investigate the differences and similarities of these criteria, we applied them to a sample of 124 demented patients from the Maastricht Memory Clinic. Only 8 patients were diagnosed as having VaD by all criteria. Depending on which criteria were used, the frequencies of VaD and Alzheimer''s disease (AD) ranged from 6 to 32%, and from 48 to 56%, respectively. The IS of Hachinski and Rosen resulted in the highest frequencies of VaD, whereas the criteria of Erkinjuntti and those from the ADDTC and the NINDS workgroup yielded the lowest. The number of patients with VaD was reduced substantially when neuroradiological data and the temporal relationship between stroke and dementia were taken into consideration. We conclude that the seven sets of criteria cannot be regarded as interchangeable. Differences in the criteria for VaD and AD may be an overlooked source of interstudy variance

Estimating the Magnitude of Genetic Factors by Calculating the Genetic Relative Risk of Stroke in First-Ever Lacunar Stroke Patients

BACKGROUND: Positive family history of stroke is an independent risk factor for lacunar stroke. However, the magnitude of familial aggregation of a certain disease is better evaluated by the genetic relative risk. This is calculated by dividing the prevalence of specific disease in family members of patients by the prevalence of this disease in the general population. In a cohort of lacunar stroke patients, who were subtyped clinically and radiologically, we determined the genetic relative risk of stroke. METHODS: By questionnaire and additional interview, we obtained a complete first-degree family history of stroke. The prevalence of stroke in first-degree relatives of these lacunar stroke patients was compared to the self-reported prevalence of stroke in a Dutch community based cohort of elderly volunteers. Secondly, the influence of proband characteristics and family composition on parental and sibling history of stroke were evaluated. PRINCIPAL FINDINGS: We collected data of 1066 first-degree relatives of 195 lacunar stroke patients. Strokes occurred in 13.5% of first-degree relatives. The genetic relative risk was 2.94 (95%CI 2.45-3.53) for overall first-degree relatives, 4.52 (95%CI 3.61-5.65) for patients' parents and 2.10 (95%CI 1.63-2.69) for patients' siblings. Age of proband and proband status for hypertension influenced the chance of having a parent with a history of stroke whereas the likelihood of having a concordant sibling increased with sibship size. CONCLUSIONS: We found an increased genetic relative risk of stroke in first-degree relatives of patients with lacunar stroke. Our data warrant further genomic research in this well-defined high risk population for stroke

Tumors Widely Express Hundreds of Embryonic Germline Genes.

We have recently described a class of 756 genes that are widely expressed in cancers, but are normally restricted to adult germ cells, referred to as germ cell cancer genes (GC genes). We hypothesized that carcinogenesis involves the reactivation of biomolecular processes and regulatory mechanisms that, under normal circumstances, are restricted to germline development. This would imply that cancer cells share gene expression profiles with primordial germ cells (PGCs). We therefore compared the transcriptomes of human PGCs (hPGCs) and PGC-like cells (PGCLCs) with 17,382 samples from 54 healthy somatic tissues (GTEx) and 11,003 samples from 33 tumor types (TCGA), and identified 672 GC genes, expanding the known GC gene pool by 387 genes (51%). We found that GC genes are expressed in clusters that are often expressed in multiple tumor types. Moreover, the amount of GC gene expression correlates with poor survival in patients with lung adenocarcinoma. As GC genes specific to the embryonic germline are not expressed in any adult tissue, targeting these in cancer treatment may result in fewer side effects than targeting conventional cancer/testis (CT) or GC genes and may preserve fertility. We anticipate that our extended GC dataset enables improved understanding of tumor development and may provide multiple novel targets for cancer treatment development

A pseudointegrable Andreev billiard

A circular Andreev billiard in a uniform magnetic field is studied. It is demonstrated that the classical dynamics is pseudointegrable in the same sense as for rational polygonal billiards. The relation to a specific polygon, the asymmetric barrier billiard, is discussed. Numerical evidence is presented indicating that the Poincare map is typically weak mixing on the invariant sets. This link between these different classes of dynamical systems throws some light on the proximity effect in chaotic Andreev billiards.Comment: 5 pages, 5 figures, to appear in PR

Prognostic Factors for Distress After Genetic Testing for Hereditary Cancer

The psychological impact of an unfavorable genetic test result for counselees at risk for hereditary cancer seems to be limited: only 10-20 % of counselees have psychological problems after testing positive for a known familial mutation. The objective of this study was to find prognostic factors that can predict which counselees are most likely to develop psychological problems after presymptomatic genetic testing. Counselees with a 50 % risk of BRCA1/2 or Lynch syndrome completed questionnaires at three time-points: after receiving a written invitation for a genetic counseling intake (T1), 2-3 days after receiving their DNA test result (T2), and 4-6 weeks later (T3). The psychological impact of the genetic test result was examined shortly and 4-6 weeks after learning their test result. Subsequently, the influence of various potentially prognostic factors on psychological impact were examined in the whole group. Data from 165 counselees were analyzed. Counselees with an unfavorable outcome did not have more emotional distress, but showed significantly more cancer worries 4-6 weeks after learning their test result. Prognostic factors for cancer worries after genetic testing were pre-existing cancer worries, being single, a high risk perception of getting cancer, and an unfavorable test result. Emotional distress was best predicted by pre-existing cancer worries and pre-existing emotional distress. The psychological impact of an unfavorable genetic test result appears considerable if it is measured as "worries about cancer." Genetic counselors should provide additional guidance to counselees with many cancer worries, emotional distress, a high risk perception or a weak social network