Studies in the radiobiology of osteoradionecrosis and their clinical significance

The radiobiology of osteoradionecrosis is a complex of cellular death and cellular functional impairments from radiation energy transfers. Four studies of irradiated patients and a data base from 536 patients with osteoradionecrosis revealed separate pathophysiologic conditions for osteoradionecrosis induced by early trauma, osteoradionecrosis induced by late trauma, and spontaneous osteoradionecrosis. A large body of data suggested useful clinical guidelines for the management of irradiated patients. The guidelines, in part, include a recommendation for deferring radiation treatment for 21 days after tissue wounding, if possible; a relative contraindication to wounding tissue during a radiation course; a recommendation for the use of hyperbaric oxygen before wounding; and a strong recommendation to provide comprehensive dental care to the irradiated patient.     

Effect of compressive follower preload on the flexion-extension response of the human lumbar spine.

Traditional experimental methods are unable to study the kinematics of whole lumbar spine specimens under physiologic compressive preloads because the spine without active musculature buckles under just 120 N of vertical load. However, the lumbar spine can support a compressive load of physiologic magnitude (up to 1200 N) without collapsing if the load is applied along a follower load path. This study tested the hypothesis that the load-displacement response of the lumbar spine in flexion-extension is affected by the magnitude of the follower preload and the follower preload path. Twenty-one fresh human cadaveric lumbar spines were tested in flexion-extension under increasing compressive follower preload applied along two distinctly different optimized preload paths. The first (neutral) preload path was considered optimum if the specimen underwent the least angular change in its lordosis when the full range of preload (0-1200 N) was applied in its neutral posture. The second (flexed) preload path was optimized for an intermediate specimen posture between neutral and full flexion. A twofold increase in flexion stiffness occurred around the neutral posture as the preload was increased from 0 to 1200 N. The preload magnitude (400 N and larger) significantly affected the range of motion (ROM), with a 25% decrease at 1200 N preload applied along the neutral path. When the preload was applied along a path optimized for an intermediate forward-flexed posture, only a 15% decrease in ROM occurred at 1200 N. The results demonstrate that whole lumbar spine specimens can be subjected to compressive follower preloads of in vivo magnitudes while allowing physiologic mobility under flexion-extension moments. The optimized follower preload provides a method to simulate the resultant vector of the muscles that allow the spine to support physiologic compressive loads induced during flexion-extension activities.     

Analysis of a protocol for an autologous blood transfusion program for total joint replacement surgery

This retrospective study analysed an autologous blood transfusion program for total joint replacement surgery. A group of 99 patients receiving autologous blood transfusion was compared with a control group of 55 patients. One-unit phlebotomies were done 14 and 7 days before surgery. The whole blood was transfused intraoperatively. Preoperative hemoglobin values were within the normal range for all patient groups except the female autologous blood group for which the mean value was 122 +/- 11.3 g/L. Due to perioperative hemodilution, the postoperative hemoglobin values were substantially lower than preoperative values for all groups. Mean intraoperative blood loss was similar for the autologous and control groups (650 to 750 ml). No adverse reactions were associated with the autologous transfusions and 74% of the autologous group received autologous blood only. From this analysis a 3-week, three-unit preoperative collection was proposed for future use. A standardized protocol will allow logistical ease and implementation of the program for various surgical procedures.     

Nutrition and somatomedin. XVI: Somatomedins and somatomedin inhibitors in fasted and refed rats

Nutritional deprivation is associated with poor growth and decreased levels of net circulating somatomedin activity, as measured by bioassay. Since somatomedin activity reflects the contributions both of somatomedins (which stimulate cartilage) and of somatomedin inhibitors (which antagonize the ability of the somatomedins to stimulate cartilage), we asked if changes in net somatomedin activity could involve progressive underlying alterations in levels of both somatomedins and somatomedin inhibitors. Groups of rats were killed during three days of fasting and 24 hours of refeeding. Fasting was associated with a rise in serum beta-hydroxybutyrate from 1.6 to 12.6 mmol/L after one day, followed by a decline to 4 mmol/L at three days. Somatomedins (low-MW) were separated from somatomedin inhibitors (high-MW) by gel permeation chromatography at acid pH on Sephadex G-50 and TSK-2000 HPLC. Somatomedins fell 35% after one day of fasting, and decreased to 59% below control levels after three days (P less than .05). Somatomedins did not change with six hours of refeeding, but then rose rapidly, reaching control levels after 24 hours. Somatomedins were correlated with change in weight (r = .41, P less than .05), but not with glucose or beta-hydroxybutyrate. Inhibitors rose to 195% above control-levels after one day of fasting, and continued to rise to 375% above control after three days (P less than .01). In contrast to the delayed change in somatomedins with refeeding, there was an abrupt fall in inhibitors (41% below three-day fasted levels after six hours), returning to control levels after 24 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Élaboration d’un guide d’information SOR SAVOIR PATIENT à l’usage des personnes malades et de leurs proches sur la vie intime et sexuelle pendant et après un cancer : l’étape d’état des lieux

Since 1998, the French National Federation of Comprehensive Cancer Centres (FNCLCC) has led an information program dedicated to patients and their relatives: the SOR SAVOIR PATIENT (SSP) program. The program is provided by the FNCLCC, the twenty French regional cancer centres (CLCC), the National League Against Cancer (LCC), the French National Cancer Institute (INCa), the French Hospital Federation (FHF), the National Oncology Federation of Regional and University Hospitals (FNCCHRU), the French Oncology Federation of General Hospitals (FFCHG), the National Private Hospital Union for Oncology (UNHPC), the International Union Against Cancer (UICC) and a large number of learned societies. The methodology of the program adheres to the quality criteria established for publishing documents containing information for patients. Issues related to the sexual health of cancer patients and their partners too often remain underestimated and even completely neglected by health professionals, although healthcare providers are increasingly interested in this area and patients frequently confront them with questions about this aspect of their lives. The development of an SOR SAVOIR PATIENT informational guide on the various issues related to sexuality during and after cancer treatment constitutes a first step in addressing the needs of cancer patients and others concerned. This article describes the first stage in the development of a specific SOR SAVOIR PATIENT guide that focuses on the general availability of informational material in French on the sexual health of patients and their partners during and after cancer treatment.     

Tricyclic antidepressant overdose. A review

Significant advances in diagnosis and management of tricyclic antidepressant overdose have occurred in recent years. This article reviews epidemiologic, pharmacologic, and therapeutic information to provide a systematic approach to these potentially life-threatening overdoses. The tricyclics are discussed as a group, with individual drugs specified when established differences exist.     

What is the most useful and cost-effective strategy to screen for left ventricular systolic dysfunction in clinical practice?: reply

We agree with many of the comments made by Yamada et al.,¹namely that the ECG and NTproBNP are fundamental tests usedin the diagnosis of heart failure and that     

Examining preferences for allocating health care gains

This study is part of a programme to elicit and examine community preferences for health care in different contexts. Data were obtained from a group of predominantly Australian health care decision-makers. A short questionnaire contained six valuation questions and four demographic questions. The six valuation questions posed choices where equal health gains were to be allocated to different population groups based upon: age; sex; current health; socio-economic status; across time; and across different numbers of individuals. The results provide some evidence that respondents were prepared to discriminate between health gains derived in different contexts especially where health gains were to be allocated between groups of different health status and over time. Further research is planned and the possible implications for health policy, and in particular for resource allocation in health care, are briefly discussed.     

The effects of various indwelling ureteral catheter materials on the normal canine ureter

In an attempt to objectively evaluate the biocompatibility of materials commonly used for ureteral stenting, stent-catheters made of four different materials were placed randomly in 31 ureters of 19 mongrel dogs. Animals underwent urography at four weeks and were sacrificed at six weeks. Mild hydronephrosis was noted in eight instances, essentially unrelated to specific material. Silicone, C-flex and polyurethane stents caused a similar, mild degree of ureteral edema, but ureters stented with Silitek demonstrated fairly marked edema. Epithelial ulceration and erosion, often severe, occurred with all polyurethane stents, and rarely with the three other materials. All materials differed statistically from controls, and C-flex caused less reaction overall than polyurethane, indicating differences in biocompatibility of the various materials which may be relevant to their use in patients undergoing long-term ureteral stenting. In practical terms, these suggest that certain materials, notably silicone and C-flex, are more suitable for ureteral stenting than others.