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1.
Summary Mitotic index of the bone marrow cells was studied in femoral bone marrow of mice given 313 kBq239Pu kg–1. The attention was turned to the femoral midshaft and the mitose concentration, intensified by Colcemid stathmokinetic effect, was evaluated in a sampling field from endosteal surface to the central venous canal, throughout 68 weeks. It has been found that the plutonium effect in the sampling band is rather uniform except the points in subendosteal zone early after plutonium injection, where the mitotic index was reduced in such a way that the mitotic gradient, observed in controls, was affected. The mitotic activity in femoral diaphysis of plutonium injected mice was mobilized approximately till the 30th week of contamination. Later it deteriorated progressively. The results are discussed and should not be regarded as representative for the entire bone marrow hemopoiesis.  相似文献   

2.
The famous and oft-quoted maxim “Do no harm” should not be thought of as the first principle of medical ethics. The documents of the Hippocratic tradition and clinical experience indicate that a more appropriate and helpful first principle would be “Above all, be useful.” The concept of usefulness implicitly rests at the very heart of medicine itself and the physician-patient relationship. The failure to adhere to this concept undermines the physician-patient relationship, dissolves the distinction between quacks and physicians, and destroys the integrity of the medical profession. The determination of useful medical treatment belongs to both physicians and patients. Any decision to initiate, continue, or discontinue diagnostic or therapeutic action has both a medical and a personal value component; the former properly belongs to physicians and the latter to patients. Practicing medicine with the intent of producing benefit and being useful to the patient is far more fundamental than practicing medicine to avoid harm.  相似文献   

3.
Radiation effects on mortality from solid cancers other than lung, liver, and bone cancer in the Mayak worker cohort: 1948–2008. The cohort of Mayak Production Association (PA) workers in Russia offers a unique opportunity to study the effects of prolonged low dose rate external gamma exposures and exposure to plutonium in a working age population. We examined radiation effects on the risk of mortality from solid cancers excluding sites of primary plutonium deposition (lung, liver, and bone surface) among 25,757 workers who were first employed in 1948–1982. During the period 1948–2008, there were 1,825 deaths from cancers other than lung, liver and bone. Using colon dose as a representative external dose, a linear dose response model described the data well. The excess relative risk per Gray for external gamma exposure was 0.16 (95% CI: 0.07 – 0.26) when unadjusted for plutonium exposure and 0.12 (95% CI 0.03 – 0.21) when adjusted for plutonium dose and monitoring status. There was no significant effect modification by sex or attained age. Plutonium exposure was not significantly associated with the group of cancers analyzed after adjusting for monitoring status. Site-specific risks were uncertainly estimated but positive for 13 of the 15 sites evaluated with a statistically significant estimate only for esophageal cancer. Comparison with estimates based on the acute exposures in atomic bomb survivors suggests that the excess relative risk per Gray for prolonged external exposure in Mayak workers may be lower than that for acute exposure but, given the uncertainties, the possibility of equal effects cannot be dismissed.  相似文献   

4.
This paper describes the experiencesof physicians-in-training at a public hospitalin Nairobi, Kenya, where medical professionalspractice in an environment characterized byboth significant lack of resources andpatients with HIV/AIDS in historicallyunprecedented numbers. The data reported hereare part of a larger study examining ethicaldilemmas in medical education and practiceamong physicians in East Africa. Aquestionnaire and semi-structured interviewwere completed by fifty residents in fourmedical specialties, examining social andemotional supports, personal and professionalsources of stress, emotional numbing anddisengagement from patients and peers, andsymptoms of post-traumatic stress anddepression. The factors affecting residentwell-being are found in this study to be morecomplex than previous interviews suggested. This study highlights the fact that as a resultof working in an environment characterized by poor communication among hospital staff aswell as a lack of resources and high numbersof patients with HIV/AIDS, residents'perceptions of themselves – their technicalproficiency, their ability to care and feel forothers and themselves, and for some theirentire sense of self – are significantlyaffected. Also affected are the patients theywork to treat.  相似文献   

5.
Catechol-O-methyltransferase (COMT) exists as two isoenzymes, a membrane-bound form (MB–COMT) and a soluble form (S–COMT), with different roles in the metabolism of catecholamines and other catechol compounds. This report documents an HPLC assay for separate estimation of S–COMT and MB–COMT activity and examines activities of the two isoezymes among different rat tissues and in human and rat erythrocytes. Activities of MB–COMT and S–COMT varied widely among tissues. There were higher activities of S–COMT than MB–COMT in all tissues except the adrenal medulla where MB–COMT was the predominant isoenzyme, consistent with the importance of this tissue and MB–COMT for the O-methylation of catecholamines. MB–COMT and S–COMT in rat and human erythrocytes showed divergent levels and patterns of activity. The assay represents a rapid and accurate method for quantifying MB–COMT and S–COMT in various tissues and examining the relative roles of COMT isoenzymes in the metabolism of catechol compounds in health and disease.  相似文献   

6.
Fifty-two pharmacologically treated hypertensive patients were randomized to one of four treatment groups: (1) diastolic blood pressure biofeedback, (2) progressive deep muscle relaxation training, (3) self-directed relaxation training, or (4) medication alone. Data collection occurred during baseline, treatment, and 1-year follow-up phases in a laboratory, a medical clinic, and the patient's own home. Patients from all four groups combined showed mean blood pressure reductions of –10.2/–5.5 mm Hg on clinic recordings and –2.4/–.7 mm Hg on home recordings, which were maintained throughout the follow-up period. There were no significant differences among the four groups in terms of blood pressure reduction. Patients given adjunctive behavioral treatment showed significantly larger reductions in medication usage compared to patients treated with medication alone, but there were no significant differences among the three behaviorally treated groups. Patients who showed medication reductions did not show subsequent blood pressure elevation. The results suggest that combined behavioral and pharmacological therapy may be superior to pharmacological therapy alone in the treatment of essential hypertension.This research was supported in part by NIH research grant number HL27698. The contribution of Jacquelyn Bain is gratefully acknowledged. We thank Merrell-National Laboratories for providing Metahydrin that was used by some of the patients in this study.  相似文献   

7.
A total of 134 cases of H7N9 influenza infection were identified in 12 provinces of China between March 25 and September 31, 2013. Of these, 46 cases occurred in Zhejiang Province. We carried out a preliminary comparison of characteristics between rural and urban H7N9 cases from Zhejiang Province, China. Field investigations were conducted for each confirmed H7N9 case. A standardized questionnaire was used to collect information about demographics, exposure history, clinical signs and symptoms, timelines of medical visits and care after onset of illness. Of the 46 H7N9 cases in Zhejiang Province identified between March 25 and September 31, 2013, there were 16 rural cases and 30 urban cases. Compared to urban cases, there was a higher proportion of females among the rural cases [11/16 (69%) vs. 6/30 (20%), P = 0.001]. Among the rural cases, 14/15 (93%) with available data had a history of recent poultry exposure, which was significantly higher than that among urban cases (64%, P = 0.038). More patients from the rural group had a history of breeding poultry compared with those from the urban group [38% (6/16) vs. 10% (3/30), respectively; P = 0.025]. Interestingly, the median number of medical visits of patients from rural areas was higher than that of patients from urban areas (P = 0.046). There was no difference between the two groups in terms of age distribution, fatality rate, incubation period, symptoms, and underlying medical conditions. In conclusion, compared to patients from urban areas, more patients from rural areas were female, had an exposure history, had a history of breeding poultry, and had a higher number of medical visits. These findings indicate that there are different exposure patterns between patients living in rural and urban areas and that more rural cases were infected through backyard poultry breeding.  相似文献   

8.
The information about disease burden and epidemiology of invasive listeriosis in Asia is scarce. From 2000 to 2013, a total of 338 patients with invasive listeriosis (bacteremia, meningitis, and peritonitis) were treated at four medical centers in Taiwan. The incidence (per 10,000 admissions) of invasive listeriosis increased significantly during the 14-year period among the four centers (0.15 in 2000 and >1.25 during 2010–2012) and at each of the four medical centers. Among these patients, 45.9% were elderly (>65 years old) and 3.3% were less than one year of age. More than one-third (36.7%) of the patients acquired invasive listeriosis in the spring (April to June). Among the 132 preserved Listeria monocytogenes isolates analyzed, the most frequently isolated PCR serogroup-sequence type (ST) was IIb-ST87 (23.5%), followed by IIa-ST378 (19.7%) and IIa-ST155 (12.1%). Isolation of PCR serogroups IIb and IVb increased significantly with year, with a predominance of IIb-ST87 isolates (23.5%) and IIb-ST 228 isolates emerging in 2013. A total of 12 different randomly amplified polymorphic DNA (RAPD) patterns (Patterns I to XII) were identified among the 112 L. monocytogenes isolates belonging to eight main PCR serogroup-STs. Identical RAPD patterns were found among the isolates exhibiting the same PCR serogroup-ST. In conclusion, our study revealed that during 2000–2013, listeriosis at four medical centers in Taiwan was caused by heterogeneous strains and that the upsurge in incidence beginning in 2005 was caused by at least two predominant clones.  相似文献   

9.
10.
The 1990s were a period of considerable economic and social instability in Kazakhstan. The current study documents information on the growth performance of children living in Kazalinsk district in the far west of Kazakhstan over this turbulent period. Using anthropometric data of children, from random samples collected in 1992, 1994 and 2000, we investigate changes in body size of 4.0–4.9-year-old children over the 8-year-study period. Between 1992 and 2000, there was no statistically significant change in body size of 4.0–4.9-year-old boys, but 4.0–4.9-year-old girls became significantly smaller. This may have resulted from the prolonged period of economic instability in Kazakhstan. Furthermore, using detailed dietary intake data collected in 1994, evidence is presented to support a suggestion that the different responses to economic hardship, evidenced in the achieved body size of boys and girls, may have been influenced by gender-discrimination in household food allocation.  相似文献   

11.

Objectives

Previous clinical audits of COPD have provided relevant information about medical intervention in exacerbation admissions. The present study aims to evaluate adherence to current guidelines in COPD through a clinical audit.

Methods

This is a pilot clinical audit performed in hospital outpatient respiratory clinics in Andalusia, Spain (eight provinces with more than 8 million inhabitants), including 9 centers (20% of the public centers in the area) between 2013 and 2014. Cases with an established diagnosis of COPD based on risk factors, clinical symptoms, and a post-bronchodilator FEV1/FVC ratio of less than 0.70 were deemed eligible. The performance of the outpatient clinics was benchmarked against three guidance documents available at the time of the audit. The appropriateness of the performance was categorized as excellent (>80%), good (60−80%), adequate (40−59%), inadequate (20−39%), and highly inadequate (<20%).

Results

During the audit, 621 clinical records were audited. Adherence to the different guidelines presented a considerable variability among the different participating hospitals, with an excellent or good adherence for symptom recording, MRC or CAT use, smoking status evaluation, spirometry, or bronchodilation therapy. The most outstanding areas for improvement were the use of the BODE index, the monitoring of treatments, the determination of alpha1-antitrypsin, the performance of exercise testing, and vaccination recommendations.

Conclusions

The present study reflects the situation of clinical care for COPD patients in specialized secondary care outpatient clinics. Adherence to clinical guidelines shows considerable variability in outpatient clinics managing COPD patients, and some aspects of the clinical care can clearly be improved.  相似文献   

12.
Summary The present investigation documents morphological characteristics of human Sertoli cells of aged males. Testicular material was obtained from 35 patients (age 62–84 years) with carcinoma of the prostate who had received no previous anticancer therapy. As revealed by light and electron microscopy the appearance of the germinal epithelium showed great individual variations. In all cases examined, however, the occurrence of multinucleate Sertoli cells was a common finding. In seminiferous tubules with intact spermatogenesis these cells closely resembled the normally occurring variants, whereas they displayed features reminiscent of immaturity in the absence of germ cells. It is hypothesized that the nuclei of Sertoli cells in the special situation of aging may resume the capacity to divide, an ability normally restricted to immature cells. Thus, mitosis without subsequent cytokinesis might be an explanation for the formation of multinucleate Sertoli cells.The authors wish to thank Dr. R. Hubmann, Hamburg, for kindly supplying the testicular material. The excellent technical assistance of Mrs. E. Roosen-Runge, Mrs. E. Schäfer, and Mrs. A. Stromeyer is gratefully acknowledgedSupported by grants from the Deutsche ForschungsgemeinschaftPresented in part at the Kleinkonferenz der Deutschen Forschungsgemeinschaft, Schloß Auel, October 3–5, 1980  相似文献   

13.

Objective

To evaluate the clinical impact of chromosomal microarray (CMA) on the management of paediatric patients in Hong Kong.

Methods

We performed NimbleGen 135k oligonucleotide array on 327 children with intellectual disability (ID)/developmental delay (DD), autism spectrum disorders (ASD), and/or multiple congenital anomalies (MCAs) in a university-affiliated paediatric unit from January 2011 to May 2013. The medical records of patients were reviewed in September 2013, focusing on the pathogenic/likely pathogenic CMA findings and their “clinical actionability” based on established criteria.

Results

Thirty-seven patients were reported to have pathogenic/likely pathogenic results, while 40 had findings of unknown significance. This gives a detection rate of 11% for clinically significant (pathogenic/likely pathogenic) findings. The significant findings have prompted clinical actions in 28 out of 37 patients (75.7%), while the findings with unknown significance have led to further management recommendation in only 1 patient (p<0.001). Nineteen out of the 28 management recommendations are “evidence-based” on either practice guidelines endorsed by a professional society (n = 9, Level 1) or peer-reviewed publications making medical management recommendation (n = 10, Level 2). CMA results impact medical management by precipitating referral to a specialist (n = 24); diagnostic testing (n = 25), surveillance of complications (n = 19), interventional procedure (n = 7), medication (n = 15) or lifestyle modification (n = 12).

Conclusion

The application of CMA in children with ID/DD, ASD, and/or MCAs in Hong Kong results in a diagnostic yield of ∼11% for pathogenic/likely pathogenic results. Importantly the yield for clinically actionable results is 8.6%. We advocate using diagnostic yield of clinically actionable results to evaluate CMA as it provides information of both clinical validity and clinical utility. Furthermore, it incorporates evidence-based medicine into the practice of genomic medicine. The same framework can be applied to other genomic testing strategies enabled by next-generation sequencing.  相似文献   

14.

Background

Publication of clinical research findings in prominent journals influences health beliefs and medical practice, in part by engendering news coverage. Randomized controlled trials (RCTs) should be most influential in guiding clinical practice. We determined whether study design of clinical research published in high-impact journals influences media coverage.

Methods and Findings

We compared the incidence and amount of media coverage of RCTs with that of observational studies published in the top 7 medical journals between 1 January 2013 and 31 March 2013. We specifically assessed media coverage of the most rigorous RCTs, those with >1000 participants that reported ‘hard’ outcomes. There was no difference between RCTs and observational studies in coverage by major newspapers or news agencies, or in total number of news stories generated (all P>0.63). Large RCTs reporting ‘hard’ outcomes did not generate more news coverage than small RCTs that reported surrogate outcomes and observational studies (all P>0.32). RCTs were more likely than observational studies to attract a journal editorial (70% vs 46%, P = 0.003), but less likely to be the subject of a journal press release (17% vs 50%, P<0.001). Large RCTs that reported ‘hard’ outcomes did not attract an editorial more frequently than other studies (61% vs 58%, P>0.99), nor were they more likely to be the subject of a journal press release (14% vs 38%, P = 0.14).

Conclusions

The design of clinical studies whose results are published in high-impact medical journals is not associated with the likelihood or amount of ensuing news coverage.  相似文献   

15.
Liver cancer mortality risks were evaluated in 11,000 workers who started working at the "Mayak" Production Association in 1948-1958 and who were exposed to both internally deposited plutonium and external gamma radiation. Comparisons with Russian liver cancer incidence rates indicate excess risk, especially among those with detectable plutonium body burdens and among female workers in the plutonium plant. Comparisons within the Mayak worker cohort which evaluate the role of plutonium body burden with adjustment for cumulative external dose indicate excess risk among workers with burdens estimated to exceed 7.4 kBq (relative risk = 17; 95% CI = 8. 0-36) and among workers in the plutonium plant who did not have routine plutonium monitoring data based on urine measurements (relative risk = 2.8; 95% CI = 1.3-6.2). In addition, analyses treating the estimated plutonium body burden as a continuous variable indicate increasing risk with increasing burden (P < 0.001). Relative risks tended to be higher for females than for males, probably because of the lower baseline risk and the higher levels of plutonium measured in females. Because of limitations in current plutonium dosimetry, no attempt was made to quantify liver cancer risks from plutonium in terms of organ dose, and risk from external dose could not be reliably evaluated.  相似文献   

16.
The consolidation of the scientific publishing industry has been the topic of much debate within and outside the scientific community, especially in relation to major publishers’ high profit margins. However, the share of scientific output published in the journals of these major publishers, as well as its evolution over time and across various disciplines, has not yet been analyzed. This paper provides such analysis, based on 45 million documents indexed in the Web of Science over the period 1973-2013. It shows that in both natural and medical sciences (NMS) and social sciences and humanities (SSH), Reed-Elsevier, Wiley-Blackwell, Springer, and Taylor & Francis increased their share of the published output, especially since the advent of the digital era (mid-1990s). Combined, the top five most prolific publishers account for more than 50% of all papers published in 2013. Disciplines of the social sciences have the highest level of concentration (70% of papers from the top five publishers), while the humanities have remained relatively independent (20% from top five publishers). NMS disciplines are in between, mainly because of the strength of their scientific societies, such as the ACS in chemistry or APS in physics. The paper also examines the migration of journals between small and big publishing houses and explores the effect of publisher change on citation impact. It concludes with a discussion on the economics of scholarly publishing.  相似文献   

17.
《Inorganica chimica acta》2006,359(1):237-242
We determined structural parameters for the near-neighbor surrounding of plutonium(III) in complexes with humic and fulvic acids at pH 1 and for the purpose of comparison also for the plutonium(III) aquo ion by means of X-ray absorption fine structure (XAFS) spectroscopy. It could be shown that in the complexes with humic substances as well as in the plutonium(III) aquo ion sample the trivalent oxidation state of plutonium was stable within the time of the experiment. In the humate and fulvate complexes, the plutonium(III) is surrounded by about eight oxygen atoms with an average Pu–O distance of 2.48 ± 0.02 Å. The structural parameters determined for plutonium(III)–humate and –fulvate complexes were compared to structural parameters of plutonium(III) and plutonium(IV) aquo ions.  相似文献   

18.
Wound contamination with plutonium was simulated in rats by injection into either muscle or subcutaneous tissue. The distribution after the injection of plutonium nitrate indicated that: (i) clearance from the contaminated tissue was due mainly to the movement of soluble complexes of plutonium, principally to the skeleton and liver, but also involved slower movement of polymerized, particulate plutonium to lymph nodes; (ii) clearance of soluble plutonium, and hence the overall state of clearance, was dependent on the tissue fluid flow through the contiminated tissue and the mass of plutonium deposited; (iii) lymphatic clearance of particulate plutonium resulted in the release of some particles into the circulation and subsequent uptake by the liver. Intramuscular deposition of small plutonium dioxide particles (approximately 1 nm in diameter) resulted in a greater rate of clearance of plutonium than deposition of the nitrate. Although the solubility of these particles was evident from the level of skeletal uptake of plutonium, a high level of excretion indicated that some plutonium was filtered into the urine in an undissolved form.  相似文献   

19.
BackgroundConsensus statements and clinical practice guidelines are widely available for enhancing the care of cancer patients. Despite subtle differences in their definition and purpose, these terms are often used interchangeably. We systematically assessed the methodological quality of consensus statements and clinical practice guidelines published in three commonly read, geographically diverse, cancer-specific journals. Methods Consensus statements and clinical practice guidelines published between January 2005 and September 2013 in Current Oncology, European Journal of Cancer and Journal of Clinical Oncology were evaluated. Each publication was assessed using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) rigour of development and editorial independence domains. For assessment of transparency of document development, 7 additional items were taken from the Institute of Medicine’s standards for practice guidelines and the Journal of Clinical Oncology guidelines for authors of guidance documents.MethodsConsensus statements and clinical practice guidelines published between January 2005 and September 2013 in Current Oncology, European Journal of Cancer and Journal of Clinical Oncology were evaluated. Each publication was assessed using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) rigour of development and editorial independence domains. For assessment of transparency of document development, 7 additional items were taken from the Institute of Medicine''s standards for practice guidelines and the Journal of Clinical Oncology guidelines for authors of guidance documents.FindingsThirty-four consensus statements and 67 clinical practice guidelines were evaluated. The rigour of development score for consensus statements over the three journals was 32% lower than that of clinical practice guidelines. The editorial independence score was 15% lower for consensus statements than clinical practice guidelines. One journal scored consistently lower than the others over both domains. No journals adhered to all the items related to the transparency of document development. One journal’s consensus statements endorsed a product made by the sponsoring pharmaceutical company in 64% of cases.ConclusionGuidance documents are an essential part of oncology care and should be subjected to a rigorous and validated development process. Consensus statements had lower methodological quality than clinical practice guidelines using AGREE II. At a minimum, journals should ensure that that all consensus statements and clinical practice guidelines adhere to AGREE II criteria. Journals should consider explicitly requiring guidelines to declare pharmaceutical company sponsorship and to identify the sponsor’s product to enhance transparency.  相似文献   

20.
Recent developments in infertility treatment, as well as medical and ethical concern to preserve the fertilizing ability of male subjects potentially at risk, led to the inception of a sperm cryobank in our medical center in 1996. Up to the end of the year 2000, 64 young men displaying higher semen values than generally required were accepted as donors, while 305 married (mean age 32.5, range 22–54) and 381 single women (mean age 41.2, range 27–50) were treated by artificial insemination donor (AID), resulting in 251 conceptions. Besides, 437 male subjects aged 15–61 requested sperm cryopreservation. Methodological considerations about sperm cryopreservation, and behavioral implications therefrom, are evaluated.  相似文献   

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