Carboxylated molecules regulate magnesium content of amorphous calcium carbonates during calcification

With the realization that many calcified skeletons form by processes involving a precursor phase of amorphous calcium carbonate (ACC), a new paradigm for mineralization is emerging. There is evidence the Mg content in biogenic ACC is regulated by carboxylated (acidic) proteins and other macromolecules, but the physical basis for such a process is unknown. We test the hypothesis that ACC compositions express a systematic relationship to the chemistry of carboxyl-rich biomolecules. A series of inorganic control experiments were conducted to establish the dependence of Mg/Ca ratios in ACC on solution composition. We then determined the influence of a suite of simple carboxylated organic acids on Mg content. Molecules with a strong affinity for binding Ca compared with Mg promote the formation of Mg-enriched ACC that is compositionally equivalent to high-magnesium calcites and dolomite. Measurements show Mg/Ca ratios are controlled by a predictable dependence upon the binding properties of the organic molecules. The trend appears rooted in the conformation and electrostatic potential topology of each molecule, but dynamic factors also may be involved. The dependence suggests a physical basis for reports that specific sequences of calcifying proteins are critical to modulating mineralization. Insights from this study may provide a plausible explanation for why some biogenic carbonates and carbonaceous cements often contain higher Mg signatures than those that are possible by classical crystal growth processes. The findings reiterate the controls of microenvironment on mineralization and suggest an origin of compositional offsets, or vital effects, long recognized by the paleoclimate community.     

Assessment of a daily online implanted fiducial marker‐guided prostate radiotherapy process

The aims of this study were to investigate whether intrafraction prostate motion can affect the accuracy of online prostate positioning using implanted fiducial markers and to determine the effect of prostate rotations on the accuracy of the software‐predicted set‐up correction shifts. Eleven patients were treated with implanted prostate fiducial markers and online set‐up corrections. Orthogonal electronic portal images were acquired to determine couch shifts before treatment. Verification images were also acquired during treatment to assess whether intrafraction motion had occurred. A limitation of the online image registration software is that it does not allow for in‐plane prostate rotations (evident on lateral portal images) when aligning marker positions. The accuracy of couch shifts was assessed by repeating the registration measurements with separate software that incorporates full in‐plane prostate rotations. Additional treatment time required for online positioning was also measured. For the patient group, the overall postalignment systematic prostate errors were less than 1.5 mm (1 standard deviation) in all directions (range 0.2–3.9 mm). The random prostate errors ranged from 0.8 to 3.3 mm (1 standard deviation). One patient exhibited intrafraction prostate motion, resulting in a postalignment prostate set‐up error of more than 10 mm for one fraction. In 14 of 35 fractions, the postalignment prostate set‐up error was greater than 5 mm in the anterior–posterior direction for this patient. Maximum prostate rotations measured from the lateral images varied from 2° to 20° for the patients. The differences between set‐up shifts determined by the online software without in‐plane rotations to align markers, and with rotations applied, was less than 1 mm (root mean square), with a maximum difference of 4.1 mm. Intrafraction prostate motion was found to reduce the effectiveness of the online set‐up for one of the patients. A larger study is required to determine the magnitude of this problem for the patient population. The inability in the current software to incorporate in‐plane prostate rotations is a limitation that should not introduce large errors, provided that the treatment isocentre is positioned near the centre of the prostate.     

Cognitive distraction and women's sexual functioning

Past research on the role of cognitive distraction in sexual dysfunction typically has focused on males and has been conducted in the laboratory using artificial stimuli. In the current study, young adult women (N = 74) with coital experience completed questionnaires regarding cognitive distraction and their sexuality. Those women who reported greater cognitive distraction during sexual activity with a partner also reported relatively lower sexual esteem, less sexual satisfaction, less consistent orgasms, and higher incidence of pretending orgasm even after the women's general affect, sexual desire, general self-focus, general sexual attitudes, and body dissatisfaction were statistically controlled. Results are discussed with regard to directions for future research and implications for sex therapy.     

Shared care in gastroenterology: GPs' views of open access to out-patient follow-up for patients with inflammatory bowel disease

OBJECTIVE: The aim of this study was to ascertain GPs' views about open access to out-patient follow-up for patients with inflammatory bowel disease (IBD). METHODS: Semi-structured interviews and a postal survey were carried out in general practices in West Glamorgan UK, each with at least one IBD patient taking part in a randomized trial of open access versus routine follow-up, which has been reported elsewhere. A total of 112 GPs from 53 general practices who referred the 180 study patients to specialist gastroenterological care in Neath or Swansea were included in the study. Main outcome measures were GPs' experience of the trial; preferences between methods of out-patient follow-up; and their views about enhancing open access follow-up. RESULTS: Sixty-nine GPs from 40 practices took part in the practice-specific data collection and 91 returned 156 patient-specific questionnaires. They expressed a strong preference for open access follow-up, for both specific patients (108/156 patients) and IBD patients in general (47/69 GPs). Preference for extending open access follow-up to other chronic conditions was not so strong (21/69 GPs). A substantial number of GPs considered their experience of the trial limited (30/69), and few GPs were aware of the shared care guideline distributed before the trial started (8/69). Few GPs encountered any problems in the management of the study patients (9/69) and <50% of the GPs used a Cumulative Encounter Form (29/69) developed for the study. Most GPs were supportive of giving patients written guidelines (56/69) and establishing a gastroenterological (GI) nurse practitioner (45/69). CONCLUSIONS: Open access follow-up of patients with IBD is supported by GPs. The approach would probably be improved by the distribution of written information to patients, the establishment of a GI nurse practitioner and an integrated approach between the nurse, hospital specialist, GP and patient.     

移植肾功能延迟恢复的护理体会

1临床资料我院1997-11/2004-11共行肾移植562(男386,女176)例,期中87例患者出现移植肾功能延迟恢复(DGF),男性58例,女性29例,年龄16～62(平均38.5)岁.术后常规服免疫抑制剂:环孢素,强的松,骁悉.发生DGF最早术后第4日,最晚20 d,均采用综合治疗措施,纠正水、电解质紊乱,控制血压,预防感染等,同时对不同原因引起的DGF采用相应的治疗、护理.85例患者均在术后3wk左右肾功能恢复,2例因并发症死亡.     

Breathing,sleep state,and rectal temperature oscillations.

Overheating may cause terminal apnoea and cot death. Rectal temperature and breathing patterns were examined in normal infants at home during the first 6 months of life. Twenty one infants had continuous overnight rectal temperature and breathing recordings for 429 nights (mean 20.4 nights, range 7-30) spaced over the first six months of life. Periods when breathing was ''regular'' were directly marked on single night records. Sleep state was determined from respiratory variables. ''Regular'' breathing was a reliable marker of ''quiet'' sleep (specificity 93%). The duration of ''quiet'' sleep increased from 6 to 22 minutes from two weeks to three months of age and then remained static, as did the proportion of sleep spent in the quiet phase (9% to 34%). Rectal temperature fell during 66% of quiet sleep and usually rose during rapid eye movement (REM) sleep. The drop in rectal temperature was maximal at the start of quiet sleep, whereas the maximum rise during REM sleep was reached after 10 to 15 minutes. Oscillations in rectal temperature are associated with changes in sleep and breathing state. The maturation of rectal temperature patterns during the first six months of life are closely related to a maturation of sleep state and breathing patterns.     

Metabolic effects of growth hormone treatment: an early predictor of growth response?

Fourteen children receiving one year of recombinant human growth hormone (rhGH) treatment underwent measurement of serial changes in body composition (measured by skinfold thickness, bioelectrical impedance, and H2(18)O dilution), resting energy expenditure (REE, estimated by ventilated hood indirect calorimetry), and total free living daily energy expenditure (TEE, measured by the doubly labelled water technique). Mean height velocity increased from 4.9 to 8.6 cm/year after six months of treatment. Fat free mass (FFM) increased more during the first six weeks (24.4 g/day) than from six to 26 weeks of treatment (6.8 g/day); fat mass decreased by 7.2 g/day and 1.1 g/day respectively. The six week increase in REE (kJ/day) was maintained after six months of treatment, though expressed per kilogram FFM (kJ/kgFFM/day), returned to pretreatment values by three months. Height velocity increases at six months correlated with six week changes in fat mass measured by skinfold thickness and REE, though use of this relationship to predict growth response in individuals is limited by the wide 95% prediction intervals. No significant changes in growth, body composition, or energy expenditure were observed between six and 12 months of treatment, in either patients who had initially responded well to treatment or those who were poor initial responders to treatment and who had their dose of rhGH doubled after six months.     

Accuracy of passive ankle joint positioning during quiet stance in young and elderly subjects

Age-related postural deficits elicit compensatory mechanisms such as ankle dorsiflexion in the elderly. To gain further insight into this problem, the ability to match an ankle angle during quiet stance was studied in 12 elderly and 12 young subjects. Following an initial single limb angular perturbation presented in the ±4° range, a subject had to return a tilt platform to level, as determined by the nonperturbed limb. Elderly subjects exhibited significant positive (0.9°) over-shoot of the level position, in contrast to young subjects who matched ankle angle with a mean error of −0.1°. The elderly group also exhibited an increase in positioning error for angular displacements in the range between −1 and +1°. The results document age-related postural changes in ankle positioning which might affect postural stability in older adults.     

Multiple myeloma: evaluation by CT

Although patients who have multiple myeloma usually have straightforward clinical symptoms and corroborative radiographs, in some instances, these patients will present atypically, with symptoms suggesting active disease but radiographs that are normal or nonspecific. We reviewed the records of 32 patients who had documented multiple myeloma and had undergone CT examinations, assessing the value of those examinations. Although CT is not indicated in all patients who have multiple myeloma, it is especially useful in patients who have bone pain and normal or nonspecific radiographs. CT provided confirmatory information in all cases in which lesions were seen on radiographs. CT also frequently demonstrated a greater extent of disease than could be appreciated on the radiographs.