Clinical “case series”: a concept analysis

Objectives

To analyze the concept of “case series” in the medical literature compared with case reports.

Methods

A PubMed search for articles published during 2009 which had “case series” in their title was performed. A total number of 621 articles were retrieved. 586 papers were included in the analysis and 35 were excluded (18 were commentary letters, 5 were not in English, and twelve could not be retrieved by our Library). The number of patients and category of these articles were analyzed.

Results

The median (range) of the number of cases of articles having “case series” in their title was 7 (1–6432) cases. 186/ 586 articles had less than 5 cases (31.7%, 95% CI (28.3–35.1%)). The median (range) of the number of cases of articles having “case report” as their publication type was 4 (1–178) cases. Out of the 219 articles categorized as case reports 114 (52.1%, 95% CI (45.6–58.6%)) had less than five cases.

Conclusions

The concept of “case series” is not well defined in the literature and does not reflect a specific research design. We suggest that a case series should have more than four patients while four paitents or less should be reported individually as case reports.     

HPLC和络合-UV法测定特非那丁颗粒剂的含量

目的：用ＨＰＬＣ和电荷转移络合ＵＶ法分别测定特非那丁粒剂的含量,并对测定结果进行比较,方法：ＨＰＬＣ法,色谱柱：ＳｐｈｅｒｉｓｏｒｂＣ８（１５０＊４．６ｍｍ,５μｍ）;流动相：甲醇－０．１ｍｏｌ／Ｌ三乙胺磷酸缓冲液（８０：２０）,检测波长２３５ｎｍ。电荷转移络合ＵＶ法,利用碘与ＴＦＮ在氯仿中形成电荷转移络合物的原理,在紫外２９４ｎｍ的波长处测定ＴＦＮ的含量。结果：两法测定的线性范围和平均回收率分别     

Homocysteine and risk of age‐related macular degeneration: a systematic review and meta‐analysis

There is still no agreement on total plasma homocysteine (tHcy) role in age‐related macular degeneration (AMD), the leading cause of new blindness in industrialized countries. We performed a systematic review and meta‐analysis of the published data on the correlation between tHcy and AMD. MEDLINE/PubMed and ISI Web of Sciences searches were performed according to MOOSE guidelines. Case–control studies were eligible for inclusion. Participants and controls were AMD patients and subjects without AMD. The main outcome measure was wet AMD. Homocysteine level was the main exposure variable. Data were pooled using a random‐effects model. Twelve case–control studies were identified: 10 assessed wet AMD, four dry AMD, one early AMD, one late AMD, and one any AMD. As for wet AMD, there was a total of 453 cases and 514 controls. Mean tHcy was on average 1.1 μmol/l (95% confidence interval [CI] = 0.96–1.25) greater in wet AMD cases, but there was evidence of extreme between‐study heterogeneity (p < 0.001, I² = 91.8%). In a model homogenous for age, including six wet AMD studies (214 cases, 274 controls), mean tHcy was on average 0.58 μmol/l (95% CI = 0.35–0.73) greater in the case group, a not statistically significant result (p = 0.144) associated with moderate heterogeneity (I² = 39.2%). Our meta‐analysis indicates that there is some weak evidence that increased tHcy might be associated with wet AMD; however, this result should be interpreted cautiously, because of a marked between‐study heterogeneity and the possible effect of publication bias. Future studies, preferably of cohort design, are necessary before any firm conclusions on the putative role of increased tHcy on AMD can be drawn.     

Capsular block syndrome after implantation of an accommodating intraocular lens

A patient presented with capsular block syndrome (CBS) 1 month after cataract surgery. An unexpected postoperative myopia linked to shallowing of the anterior chamber was evident. The 1540 microm IOL shift was sufficient to give useful spectacle-free near vision. A neodymium:YAG laser peripheral anterior capsulotomy enabled the intracapsular liquid to flow into the anterior chamber, allowing normal placement of a 1CU IOL (HumanOptics AG) but revealing the limited accommodative ability of the IOL to cover the dioptric range from reading distance to infinity. The visual outcome of the patient is in accord with that in other studies of the effective of IOL shifting.     

Mycosis fungoides and Sézary syndrome: Current challenges in assessment,management and prognostic markers

Mycosis fungoides and Sézary syndrome are the most common variants of the cutaneous T‐cell lymphomas. Assessment of a patient with a suspected diagnosis requires thorough history taking and physical examination, in combination with skin biopsy. In some cases flow cytometry, molecular studies and imaging are also required in order to diagnose and stage the disease. Staging is derived from the tumour‐node‐metastasis‐blood classification and is currently our best attempt to stratify prognosis and hence guide management in this complex disease. Many other clinical, biological and pathological factors may help to distinguish groups at risk and predict prognosis more accurately. Management remains heavily guided by staging, such that patients with early‐stage disease generally begin treatment with skin‐directed or local therapies and those with advanced‐stage disease have many treatment options, including chemotherapy, the use of biological agents, local and total body radiotherapy, as well as haematopoietic stem cell transplantation. Besides staging, many other patient‐related factors influence the treatment strategy, particularly where symptom relief is paramount. There are many challenges remaining in the study of Mycosis fungoides and Sézary syndrome and, given the rarity of the disease, concerted worldwide efforts are required to conduct efficient and effective research.     

Does a reduced glucose intake prevent hyperglycemia in children early after cardiac surgery? a randomized controlled crossover study

Introduction

Hyperglycemia in children after cardiac surgery can be treated with intensive insulin therapy, but hypoglycemia is a potential serious side effect. The aim of this study was to investigate the effects of reducing glucose intake below standard intakes to prevent hyperglycemia, on blood glucose concentrations, glucose kinetics and protein catabolism in children after cardiac surgery with cardiopulmonary bypass (CPB).

Methods

Subjects received a 4-hour low glucose (LG; 2.5 mg/kg per minute) and a 4-hour standard glucose (SG; 5.0 mg/kg per minute) infusion in a randomized blinded crossover setting. Simultaneously, an 8-hour stable isotope tracer protocol was conducted to determine glucose and leucine kinetics. Data are presented as mean ± SD or median (IQR); comparison was made by paired samples t test.

Results

Eleven subjects (age 5.1 (20.2) months) were studied 9.5 ± 1.9 hours post-cardiac surgery. Blood glucose concentrations were lower during LG than SG (LG 7.3 ± 0.7 vs. SG 9.3 ± 1.8 mmol/L; P < 0.01), although the glycemic target (4.0-6.0 mmol/L) was not achieved. No hypoglycemic events occurred. Endogenous glucose production was higher during LG than SG (LG 2.9 ± 0.8 vs. SG 1.5 ± 1.1 mg/kg per minute; P = 0.02), due to increased glycogenolysis (LG 1.0 ± 0.6 vs. SG 0.0 ± 1.0 mg/kg per minute; P < 0.05). Leucine balance, indicating protein balance, was negative but not affected by glucose intake (LG -54.8 ± 14.6 vs. SG -58.8 ± 16.7 μmol/kg per hour; P = 0.57).

Conclusions

Currently recommended glucose intakes aggravated hyperglycemia in children early after cardiac surgery with CPB. Reduced glucose intake decreased blood glucose concentrations without causing hypoglycemia or affecting protein catabolism, but increased glycogenolysis.

Trial registration

Dutch trial register NTR2079.     

倾斜试验中真假阳性的血流动力学和神经激素的研究

目的探讨血管迷走性晕厥患者和正常人倾斜试验阳性时不同的触发机制.方法倾斜试验采用静息平卧10min和80°直立30min.心脏监测仪连续监测心率和血压.试验阳性标准为晕厥先兆伴收缩压＜90imHg(1mmHg=O.133kPa)和(或)心率＜60次/min.超声心动图于基础平卧,直立2min和每隔3min直至试验结束时连续记录左室内径及降低速率,左室短轴缩短分数(SF)和每分心输出量(CO).同时测量平卧和直立时儿茶酚胺血浆浓度.试验分组为正常自愿者且倾斜试验阴性者8例(组1),平均年龄(34±5)岁;正常自愿者伴倾斜试验阳性者8例(组2),平均年龄(31±6)岁;原因不明晕厥伴倾斜试验阳性者16例(组3),平均年龄(30±9)岁.结果三组间年龄、性别以及基础状态下心率,平均动脉压、左室内径、SF、CO和儿茶酚胺血浆浓度无明显差异.直立时各组发生改变为(1)组3出现阳性反应时间明显短于组2[(10±4)min比(17±8)min,P＜0.05];(2)组3平均动脉压有即刻和持续性降低;(3)组3左室舒张末期内径降低速率明显大于其他两组;(4)SF在组3显著增强;(5)肾上腺素浓度在组3升高显著,试验终止时组1为(65±35)pg/ml,组2为(78±29)pg/ml,组3为(126±80)pg/ml(P均＜0.05);去甲肾上腺素在三组均增高但组间比较差异无显著性.结论血管迷走性晕厥患者和部分正常人倾斜试验虽均呈阳性反应,但血流动力学反应和触发机制不同.前者可能与外周血管张力异常,回心血量及左室容量聚降,肾上腺素分泌增多,促使左室收缩力增强触发Bezold-Jarisch神经反射有关;而后者在发生假阳性反应时,其左室内径和SF及肾上腺素血浆浓度与阴性组无明显不同.倾斜试验时血管迷走性晕厥患者肾上腺素分泌异常在血管舒缩反应损害和左室收缩力异常方面可能起恶化作用.