Detachable shape-memory sewing ring for heart valves

The novel sewing ring concept consists of a detachable ring snap connection between valve housing or stent and suture cuff. The suture cuff itself is a memory metal ring of nickel-titanium (NiTi) that is embedded within a textile fabric torus. After a special training program the ring can assume two geometric shapes when alternately cooled and heated. Due to this physical property, the sewing ring can be safely fixed within a groove of the housing or stent by changing between room and physiological temperature. This allows the surgeon first to implant the sewing ring followed by arbitrary positioning and final fixation of the valve by the shape-memory effect. Additional advantages are an increased stiffening of the valve base for minimizing potential leaflet dysfunction, and reduced time and risk of implantation, particularly when a reoperation is necessary.     

Radiosensitivity of microscopic tumours of a transplantable mammary adenocarcinoma in mice.

Evidence is presented that microscopic tumours (of a transplantable murine mammary carcinoma, M8013X) grow faster than larger, palpable, tumours. Microscopic tumours are also more radiosensitive than larger tumours. The decrease in radiosensitivity in larger tumours is prevented to a large extent by misonidazole, which has no significant effect on the radiosensitivity of microscopic tumours. The retardation in growth rate which occurs after the fast microscopic growth is probably related to the appearance of hypoxic cells. Both the decrease in growth rate and the progressive development of hypoxia may be caused by the relatively poorer blood flow in larger tumours. Part of the radioresistance in "large" tumours ( approximately 250 mm3) seems to be due to factors other than hypoxia; maybe cell-kinetic factors also play a role. The intrinsic radiosensitivity of tumour cells in microscopic tumours was assessed by means of a modified latency test: the Dq and Do were 2.2 and 2.5 Gy respectively. A number of factors which may influence the reliability of these estimates are discussed.     

A comparison in cosmetic outcome between per-operative interstitial breast implants and delayed interstitial breast implants after external beam radiotherapy.

BACKGROUND AND PURPOSE: Interstitial implants for brachytherapy boost in the breast conserving therapy of breast cancer can be performed in two ways; implants during the tumor excision (per-operative implants) or after the external beam therapy (delayed interstitial implants). Differences in cosmetic outcome were investigated. PATIENTS AND METHODS: Cosmetic results in 47 patients having a per-operative implant were compared to 123 patients having a delayed interstitial implant in a matched case-control study. Cosmesis was scored on a four-point-scale varying from 0 (excellent) to 3 (poor). RESULTS: After mean follow-up of 63 months, three observers found no difference in cosmetic outcome between the two groups after adjustment for variables found to be related with cosmesis (difference in mean score 0.50, P=0.26). Implant volume at 100% isodose was not found to differ (P=0.084) between the per-operative group (mean 102 cm3, S.D. 34 cm3) and the delayed group (mean 93 cm3, S.D. 29 cm3). CONCLUSIONS: Performing per-operative implants has not led to smaller implants. The method of performing brachytherapy does not result in marked differences in cosmetic outcome.     

Informed consent, parental awareness, and reasons for participating in a randomised controlled study

BACKGROUND: The informed consent procedure plays a central role in randomised controlled trials but has only been explored in a few studies on children. AIM: To assess the quality of the informed consent process in a paediatric setting. METHODS: A questionnaire was sent to parents who volunteered their child (230 children) for a randomised, double blind, placebo controlled trial of ibuprofen syrup to prevent recurrent febrile seizures. RESULTS: 181 (79%) parents responded. On average, 73% of parents were aware of the major study characteristics. A few had difficulty understanding the information provided. Major factors in parents granting approval were the contribution to clinical science (51%) and benefit to the child (32%). Sociodemographic status did not influence initial participation but west European origin of the father was associated with willingness to participate in future trials. 89% of participants felt positive about the informed consent procedure; however, 25% stated that they felt obliged to participate. Although their reasons for granting approval and their evaluation of the informed consent procedure did not differ, relatively more were hesitant about participating in future. Parents appreciated the investigator being on call 24 hours a day (38%) and the extra medical care and information provided (37%) as advantages of participation. Disadvantages were mainly the time consuming aspects and the work involved (23%). CONCLUSIONS: Parents' understanding of trial characteristics might be improved by designing less difficult informed consent forms and by the investigator giving extra attention and information to non-west European parents. Adequate measures should be taken to avoid parents feeling obliged to participate, rather than giving true informed consent.     

Pachymeningitis luetica: a case report

Pachymeningitis luetica is extremely rare in developed countries. We describe a 41-year-old male patient with pachymeningitis luetica, multiple ischaemic infarctions, and severe hydrocephalus. The delay in making the diagnosis contributed to patient's death. Rapid diagnosis is essential on the slightest suspicion of an infection by Treponema pallidum, because timely treatment with antibiotics is effective.     

Being circadian or not: vasopressin release in cultured SCN mirrors behavior in adult voles

We studied vasopressin (AVP) release patterns from organotypic suprachiasmatic nucleus (SCN) cultures obtained from circadian rhythmic and non-rhythmic voles. All eight SCN cultures made from non-rhythmic voles did not produce any circadian pattern in AVP release, while five out of six SCN cultures of rhythmic voles produced significant (circadian) peak values. The total amount of AVP released was 2-fold higher in SCN cultures from rhythmic vole. These data confirm our previously formulated AVP release deficit hypothesis for nonrhythmic voles, and suggest that AVP in the vole SCN plays an important role in mediating output of its circadian clock, regulating circadian organization of locomotor behavior.     

Psychological Problems among Head and Neck Cancer Patients in Relation to Utilization of Healthcare and Informal Care and Costs in the First Two Years after Diagnosis

Background: To investigate associations between psychological problems and the use of healthcare and informal care and total costs among head and neck cancer (HNC) patients. Method: Data were used of the NETherlands QUality of Life and Biomedical Cohort study. Anxiety and depression disorder (diagnostic interview), distress, symptoms of anxiety and depression (HADS), and fear of cancer recurrence (FCR) and cancer worry scale (CWS) were measured at baseline and at 12-month follow-up. Care use and costs (questionnaire) were measured at baseline, 3-, 6-, 12-, and 24-month follow-up. Associations between psychological problems and care use/costs were investigated using logistic and multiple regression analyses. Results: Data of 558 patients were used. Distress, symptoms of anxiety or depression, FCR, and/or anxiety disorder at baseline were significantly associated with higher use of primary care, supportive care, and/or informal care (odds ratios (ORs) between 1.55 and 4.76). Symptoms of anxiety, FCR, and/or depression disorder at 12-month follow-up were significantly associated with use of primary care, supportive care, and/or informal care (ORs between 1.74 and 6.42). Distress, symptoms of anxiety, and FCR at baseline were associated with higher total costs. Discussion: HNC patients with psychological problems make more use of healthcare and informal care and have higher costs. This is not the result of worse clinical outcomes.