主动脉弓分支变异螺旋CT三维成像解剖学研究

目的：探讨多层螺旋CT（MSCT）血管成像对主动脉弓分支变异的诊断能力及其三维影像解剖特征。方法：对500例接受MSCT胸部及头颈部增强扫描的患者进行回顾性动脉期三维重建，结合横断面、容积重建（VR）、多平面重建（MPR）及最大密度投影（MIP）观察主动脉弓分支变异情况。结果：84．4％（422例）为正常型，即头臂干、左颈总动脉、左锁骨下动脉从右向左分别起自于主动脉弓，15．6％（78例）为变异型。本组共发现8种不同类型的变异，包括头臂干与左颈总动脉共干分出9．4％（47例），左侧椎动脉于左颈总动脉和左锁骨下动脉之间起源于主动脉弓3．6％（18例），头臂干与左颈总动脉共干分出伴左侧椎动脉起源于主动脉弓1．0％（5例），左右颈总动脉共干伴迷走右锁骨下动脉0．6％（3例），左右颈总动脉分别从主动脉弓发出伴迷走右锁骨下动脉0．4％（2例），左侧椎动脉与左锁骨下动脉从主动脉弓共干分出0．2％（1例），右位主动脉弓伴相关结构变异0．4％（2例）。结论：主动脉弓分支的解剖变异较为复杂，CTA三维成像能予以较好的评价。     

Microsatellite instability in gastric intestinal metaplasia in patients with and without gastric cancer

The role and significance of microsatellite instability (MSI) in gastric carcinogenesis remain unknown. This study determined the chronology of MSI in gastric carcinogenesis by examining intestinal metaplasia (IM) from patients with and without gastric cancer. DNA was obtained from gastric specimens of 75 patients with gastric IM (30 cancer, 26 peptic ulcer, and 19 chronic gastritis patients) and was amplified with a set of eight microsatellite markers. Eight (26. 7%) tumors and seven (9.3%) IM samples (three from cancer-free patients) displayed high-level MSI (three or more loci altered). Low-level MSI (one or two loci altered) was detected in 50% of the tumors, in 40% of IM samples coexisting with cancer, and in 38% of IM tissues of cancer-free individuals. Among the 30 cancer patients, microsatellites were more frequently altered in IM coexisting with tumors that showed MSI (P = 0.003). In addition, patients with low-level MSI in the tumor tissues were more likely to have active Helicobacter pylori infection than those with stable tumors (P = 0.02). In conclusion, this study indicates that MSI occurs not only in gastric IM of patients with gastric carcinoma, but also in IM of cancer-free individuals. These data suggest that the progressive accumulation of MSI in areas of IM may contribute to gastric cancer development, representing an important molecular event in the multistep gastric carcinogenesis cascade.     

Nocturnal myocardial ischemia and cardiac arrhythmia in patients with sleep apnea with and without coronary heart disease

Summary To study the effect of apnea and hypoventilation-induced hypoxemia on the heart, we carried out polysomnographic recordings over; 4 nights with electrocardiographic tracings in 30 patients with and without coronary heart disease. Evaluations of the data were based on the 2nd and 4th nights. In six subjects, five with coronary heart disease, we found 85 episodes of nocturnal ischemia, mainly during REM sleep (83.5%), high apnea activity, and sustained and progressive hypoxemia. Complex ventricular ectopy was observed in 14/13 patients (nights 2/4) and repetitive ventricular ectopy in 5/3. There was no significant difference in the quality and quantity of ventricular ectopy during wake and sleep states between the CHD group and the control group. In one patient ventricular bigeminy was observed only at a threshold of SaO₂ below 60%. Bradyarrhythmia was made evident in four subjects from the CHD group and correlated mainly with apnea activity. We suppose that patients with sleep apnea and CHD are at cardiac risk because coronary heart disease can be aggravated by insufficient arterial oxygen supply due to cumulative phases of apnea and hypoventilation. The reduced hypoxic tolerance of the heart may lead to myocardial ischemia: and increased electrical instability.Abbreviations AI apnea index (apnea episodes per hour) - bpm beats per minute (heart rate) - CHD coronary heart disease - NREM non-rapid eye movement - PVC premature ventricular contraction - REM rapid eye movement - SRBD sleep-related breathing disorders     

The anatomical and clinical details of the pterygoid canal: a three-dimensional reconstructive virtual anatomic evaluation based on CT

Purpose

To delineate the pterygoid canal (PC) configuration and its position in relation to surrounding important anatomical landmarks using three-dimensional reconstructive technology based on CT for the Chinese.

Methods

The computerized tomography arteriography (CTA) data of 137 patients were retrospectively evaluated using neuroimaging three-dimensional reconstructive software. The morphological parameters of the PC as well as the spatial relationship and distance between the PC relative to internal carotid artery (ICA) and the foramen rotundum were evaluated.

Results

83.9 % of the PC can be identified by our neuroimaging three-dimensional reconstructive software. The mean distance from the PC to the ICA was 2.6 ± 1.2 mm. The mean distance between medial aspects of bilateral ICA was 19.6 ± 2.7 mm. The distal vertical and horizontal distances between the PC and foramen rotundum were 5.2 ± 3.2 and 6.1 ± 2.8 mm, respectively. All the proximal end of the PC were inferior-lateral to the ICA. The PC mainly (92.9 %) ran posteriorly with a medial to lateral direction. The distance from the PC to ICA was positively correlated with the distance between bilateral ICA and the distal diameter of the PC. The vertical distance between the PC and foramen rotundum was positively correlated with the length of the PC and the horizontal distance between the PC and foramen rotundum.

Conclusions

Understanding the configuration and spatial relationship of the PC may be helpful to improve the accuracy and safety of operation during the expanded transnasal endoscopic approaches to skull base. The three-dimensional reconstructive virtual anatomic technology may be a useful tool to delineate the PC configuration and its position to surrounding important anatomical landmarks.     

膝骨性关节炎患者胫骨软骨下骨超微结构改变的CT评价

文题释义： 膝骨性关节炎：是一种以渐进性的关节损伤为主要特征,并最终导致患者关节疼痛甚至残疾,极大地降低患者生活质量。 CT：利用精确准直的X射线束、γ射线、超声波等,与灵敏度极高的探测器一同围绕人体的某一部位作一个接一个的断面扫描,具有扫描时间快、图像清晰等特点。 背景：软骨下骨的改变在膝骨性关节炎的作用得到了越来越多的重视,但是既往研究主要以动物为观察对象,由于动物与人存在差异,因而直接在人体关节内获得相关数据是非常必要的。 目的：通过CT技术评价非膝骨性关节炎患者与膝骨性关节炎患者软骨下骨板及软骨下骨超微结构的区别,来探讨软骨下骨在膝骨性关节炎疾病的发生和发展中的作用。 方法：于2016年7月至2018年7月在郑州市骨科医院影像科就诊患者中,收集30例膝骨性关节炎患者(膝骨性关节炎组)及30例非膝骨性关节炎患者(非膝骨性关节炎组)的CT扫描数据,使用MIMICS软件比较2组胫骨平台内外侧软骨下骨板以及软骨下骨小梁超微结构。试验于2016-06-10经郑州市骨科医院伦理委员会审批通过,审批号为2016医院伦审第004号。 结果与结论：①与非膝骨性关节炎组相比,膝骨性关节炎组软骨下骨板在外侧部位和内侧部位骨密度都明显增加,孔隙率则出现显著的下降,而软骨下骨板厚度内侧部分较非膝骨性关节炎组显著增厚;②膝骨性关节炎软骨下骨小梁同样存在明显变化,表现为膝骨性关节炎组内外侧软骨下骨骨小梁厚度较非膝骨性关节炎组均明显增加,同时内侧松质骨分离度也较非膝骨性关节炎组低;膝骨性关节炎组结构模型指数和连接密度值低于非膝骨性关节炎组;③结果表明,膝骨性关节炎患者胫骨软骨下骨板及软骨下骨松质骨的改变主要在于超微结构稳态的破坏,这一改变可能是膝骨性关节炎发病原因之一。 ORCID: 0000-0002-9805-3084(白玉) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Biochemical evaluation of patients with cancer-associated hypercalcemia: evidence for humoral and nonhumoral groups

In 50 consecutive patients with cancer-associated hypercalcemia, we measured nephrogenous cyclic AMP, tubular phosphorus threshold, fasting calcium excretion, plasma 1,25-dihydroxyvitamin D, and immunoreactive parathyroid hormone as determined by four region-specific antiserums. Nephrogenous cyclic AMP excretion was elevated in 41 patients and suppressed in nine (means, 5.85 vs. 0.51 nmol per 100 ml of glomerular filtrate). There was no overlap between these groups. When compared with 15 patients with primary hyperparathyroidism, the group with increased cyclic AMP excretion had similar reductions in tubular phosphorus threshold; higher fasting calcium excretion (means, 0.66 vs. 0.25 mg per 100 ml of glomerular filtrate, P < 0.01); marked reductions in 1,25-dihydroxyvitamin D (means, 20 vs. 83 pg per milliliter, P < 0.001); and lower levels of immunoreactive parathyroid hormone in all four assays. The data suggest that elevated excretion of nephrogenous cyclic AMP may be a useful marker of humorally mediated cancer-associated hypercalcemia, that this type of hypercalcemia is common, that the humoral factor responsible for this syndrome is not native 1-84 parathyroid hormone, and that the various subtypes of cancer-associated hypercalcemia are biochemically distinguishable from primary hyperparathyroidism.     

3T MRI-based anatomy of the anterolateral knee ligament in patients with and without an ACL-rupture: Implications for anatomical anterolateral ligament reconstruction

BackgroundAnterior cruciate ligament (ACL) rupture is often accompanied by an injury to the anterolateral ligament (ALL) of the knee. Detailed knowledge of the ALL attachments in ACL-ruptured patients is essential for an anatomical ALL reconstruction to avoid knee over-constraint and successfully treat the residual rotational instability. The aim of the present study was to investigate the three-dimensional (3D), topographic anatomy of the ALL attachment in both ACL-ruptured and ACL-intact patients using 3 Tesla magnetic resonance imaging (3T MRI).MethodsIn the present, retrospective case-control study, the magnetic resonance images of 90 knees with an ACL-rupture and 90 matched-controlled subjects, who suffered a non-contact knee injury without an ACL-rupture, were used to create 3D models of the knee. The femoral and tibial ALL footprints were outlined on each model, and their position was measured using an anatomical coordinate system.ResultsThe femoral origin of the ALL was located 4.9 ± 2.8 mm posterior and 3.8 ± 2.4 mm proximal to the lateral epicondyle in a non-isometric location in control subjects. In ACL-ruptured patients, it was located in a more posterior and distal, at 6.0 ± 1.9 mm posterior and 2.4 ± 1.7 mm proximal to the lateral epicondyle (p < 0.01), also in a non-isometric location. No difference was found in the tibial ALL insertion between groups.ConclusionThe femoral ALL origin was significantly different in ACL-ruptured patients compared to ACL-intact patients. The recommended femoral tunnel position for the anatomical ALL reconstruction, does not represent the femoral ALL origin in the ACL-ruptured knee.     

CT灌注成像在急性缺血性卒中患者诊断及预后评估中的应用

目的 探讨CT灌注成像在急性缺血性卒中（AIS）患者诊断及预后评估中的应用价值。方法 回顾性研究。纳入2020年2月—2021年7月河南省直第三人民医院收治的AIS患者104例,其中,男61例、女43例,年龄46~81（62.7±12.3）岁。患者均接受急诊脑CT灌注成像检查,获取核心梗死面积,以及脑血流量（CBF）、脑血容量（CBV）、对比剂平均通过时间（MTT）和峰值时间（TTP）等CT灌注成像血流动力学参数,对比分析患者脑梗死区和缺血半暗带脑组织间CBF、CBV、MTT、TTP值的差异。以《中国急性缺血性脑卒中诊疗指南2018》为金标准,分析CT灌注成像AIS患者的检出率。入院时进行美国国立卫生研究院卒中量表（NIHSS）评分评估患者神经功能状态。治疗后3个月采用改良Rankin量表（mRS）评分评估患者预后,并按照预后评估结果进行分组观察。采用logistic回归分析AIS预后的预测因素。结果 本组104例AIS患者中,经CT灌注成像检查显示梗死区及半暗带血流异常者共96例（检出率为92.31%）。CT灌注成像检出的96例中,mRS评分评估预后良好者69例、预后不良者27例。脑梗死区和缺血半暗带分别与健侧对应部位的正常脑组织相比,CBF、CBV值降低,MTT、TTP延长,差异均有统计学意义（P值均<0.05）。预后不良组核心梗死面积、发病至溶栓时间及高脂血症比例、NIHSS评分及缺血半暗带CT灌注参数MTT、TTP均高于预后良好组,CT灌注参数CBF、CBV均低于预后良好组,差异均有统计学意义（P值均<0.05）。logistic回归分析结果显示,核心梗死面积、发病至溶栓时间、高脂血症,NIHSS评分,以及缺血半暗带CT灌注成像血流动力学参数CBF、CBV、MTT、TTP等均是AIS患者预后的预测因素（P值均<0.05）。结论 CT灌注成像检查可快速反映脑部组织灌注损伤情况,对AIS患者的及时诊断具有重要意义;且CT灌注成像血流动力学参数可有效反映AIS患者溶栓治疗后受累血管再通情况,为其预后评估提供一定依据。     

Reduction of motion blurring artifacts using respiratory gated CT in sinogram space: a quantitative evaluation

Techniques have been developed for reducing motion blurring artifacts by using respiratory gated computed tomography (CT) in sinogram space and quantitatively evaluating the artifact reduction. A synthetic sinogram was built from multiple scans intercepting a respiratory gating window. A gated CT image was then reconstructed using the filtered back-projection algorithm. Wedge phantoms, developed for quantifying the motion artifact reduction, were scanned while being moved using a computer-controlled linear stage. The resulting artifacts appeared between the high and low density regions as an apparent feature with a Hounsfield value that was the average of the two regions. A CT profile through these regions was fit using two error functions, each modeling the partial-volume averaging characteristics for the unmoving phantom. The motion artifact was quantified by determining the apparent distance between the two functions. The blurring artifact had a linear relationship with both the speed and the tangent of the wedge angles. When gating was employed, the blurring artifact was reduced systematically at the air-phantom interface. The gated image of phantoms moving at 20 mm/s showed similar blurring artifacts as the nongated image of phantoms moving at 10 mm/s. Nine patients were also scanned using the synchronized respiratory motion technique. Image artifacts were evaluated in the diaphragm, where high contrast interfaces intercepted the imaging plane. For patients, this respiratory gating technique reduced the blurring artifacts by 9%-41% at the lung-diaphragm interface.     

连续性血液净化在老年重症脓毒症病人中安全观察

目的探讨连续性血液净化对老年重症脓毒症病人的应用安全性。方法选择26例重症脓毒症病人,其中男性17例,女性9例;年龄71～89岁,平均年龄77-2岁。在常规治疗基础上,应用连续血液净化疗法,每次治疗24．48h．置换液以前稀释方式输入,血流量200—250mL/min,置换液流速3000—4000mL/h,采用普通肝素或无肝素抗凝。结果18例好转而转入普通病房继续治疗,5例因并发多脏器功能衰竭死亡,2例因心肺复苏后脑功能衰竭死亡,1例因经济原因放弃治疗。病人平均动脉压、心率和氧合指数[P（O2）FiO2]均有所改善（P〈0．05）;治疗前后血乳酸、白细胞、C-反应蛋白、降钙素原及白细胞介素-6下降明显（P〈0．05）,急性生理学及慢性健康状况评分Ⅱ（APACHEⅡ）亦较治疗前降低（P〈0．05）。结论连续性血液净化疗法对老年重症脓毒症病人并非禁忌,病人在治疗过程中血流动力学稳定,可以有效地改善预后。     

Mental stress-induced ischemia in patients with coronary artery disease: echocardiographic characteristics and relation to exercise-induced ischemia

Objective The aims of this study were to investigate the incidence and parameters associated with myocardial ischemia during mental stress (MS) as measured by echocardiography and to evaluate the relation between MS-induced and exercise-induced myocardial ischemia. Methods Study participants were 79 patients (63 men; mean [M] [standard deviation {SD}] age = 52 [8] years) with angiographically confirmed coronary artery disease and previous positive exercise test result. The MS protocol consisted of mental arithmetic and anger recall task. The patients performed a treadmill exercise test 15 to 20 minutes after the MS task. Data of post-MS exercise were compared with previous exercise stress test results. Results The frequency of echocardiographic abnormalities was 35% in response to the mental arithmetic task, compared with 61% with anger recall and 96% with exercise (p < .001, exercise versus MS). Electrocardiogram abnormalities and chest pain were substantially less common during MS than were echocardiographic abnormalities. Independent predictors of MS-induced myocardial ischemia were: wall motion score index at rest (p = .02), peak systolic blood pressure (p = .005), and increase in rate-pressure product (p = .004) during MS. The duration of exercise stress test was significantly shorter (p < .001) when MS preceded the exercise and in the case of earlier exercise (M [SD] = 4.4 [1.9] versus 6.7 [2.2] minutes for patients positive on MS and 5.7 [1.9] versus 8.0 [2.3] minutes for patients negative on MS). Conclusions Echocardiography can be successfully used to document myocardial ischemia induced by MS. MS-induced ischemia was associated with an increase in hemodynamic parameters during MS and worse function of the left ventricle. MS may shorten the duration of subsequent exercise stress testing and can potentiate exercise-induced ischemia in susceptible patients with coronary artery disease.     

Hypertrophic cardiomyopathy and sudden death in the young: pathologic evidence of myocardial ischemia

The mechanism underlying cardiac arrest in patients with hypertrophic cardiomyopathy (HC) is intriguing. In the clinical setting, myocardial ischemia has long been incriminated, particularly in the young. Among 274 cardiovascular sudden deaths in the young (< or = 35 years), 19 (7.0%), 14 males and 5 females, median age 23 years, had HC. Familial occurrence of HC was ascertained in 3 (16%). SD occurred on effort in 6 (31%). Previous syncope occurred in 5 and palpitations in 3. Basal electrocardiogram (ECG) was abnormal in 7 of 8 available cases. Hypertrophy was septal asymmetric in 14. Gross examination showed large isolated or multiple septal scars in 11 (58%); at histomorphometry, the mean percent area of fibrosis of the septal myocardium was 18.6 +/- 6. Four showed a deep intramyocardial course of the left anterior descending coronary artery. At histology, myocardial disarray involved 30 +/- 16% of the septal myocardium; evidence of acute-subacute myocardial necrosis was present in 14 (74%), 1 of them with a regional acute myocardial infarction. By comparing hearts with (n = 11) and without (n = 8) areas of scar-type fibrosis, we found a statistically significant difference in terms of age (25.5 +/- 5.4 v 15.5 +/- 12.4 years, P = .04), septal thickness (25.4 +/- 5.4 v 15.4 +/- 4.9 mm, P < .001), percent increase of septal thickness versus normal value for age and sex (46.2 +/- 15 v 25.2 +/- 13.6%, P < .01) and mean score of small vessel disease (1.7 +/- 0.4 v 1.2 +/- 0.4, P = .04). Linear regression analysis showed a positive correlation of percent area of replacement fibrosis with septal thickness (P = .01) and with mean score of small vessel disease (P < .01). In conclusion, our pathologic findings of ischemic damage, either acute-subacute or in the form of fibrotic scars, support the clinical evidence that ischemia occurs in the natural history of HC and may contribute to life-threatening electrical instability.     

Interrelated neuropsychological and anatomical evidence of hippocampal pathology in the at-risk mental state

BACKGROUND: Verbal learning and memory deficits are frequent among patients with schizophrenia and correlate with reduced magnetic resonance imaging (MRI) volumes of the hippocampus in these patients. A crucial question is the extent to which interrelated structural-functional deficits of the hippocampus reflect a vulnerability to schizophrenia, as opposed to the disorder per se. METHOD: We combined brain structural measures and the Rey Auditory Verbal Learning Test (RAVLT) to assess hippocampal structure and function in 36 never-medicated individuals suspected to be in early (EPS) or late prodromal states (LPS) of schizophrenia relative to 30 healthy controls. RESULTS: Group comparisons revealed bilaterally reduced MRI hippocampal volumes in both EPS and LPS subjects. In LPS subjects but not in EPS subjects, these reductions were correlated with poorer performance in RAVLT delayed recall. CONCLUSIONS: Our findings suggest progressive and interrelated structural-functional pathology of the hippocampus, as prodromal symptoms and behaviours accumulate, and the level of risk for psychosis increases. Given the inverse correlation of learning and memory deficits with social and vocational functioning in established schizophrenia, our findings substantiate the rationale for developing preventive treatment strategies that maintain cognitive capacities in the at-risk mental state.     

Evolution of the human hand: approaches to acquiring, analysing and interpreting the anatomical evidence

The discovery of fossil hand bones from an early human ancestor at Olduvai Gorge in 1960, at the same level as primitive stone tools, generated a debate about the role of tools in the evolution of the human hand that has raged to the present day. Could the Olduvai hand have made the tools? Did the human hand evolve as an adaptation to tool making and tool use? The debate has been fueled by anatomical studies comparing living and fossil human and nonhuman primate hands, and by experimental observations. These have assessed the relative abilities of apes and humans to manufacture the Oldowan tools, but consensus has been hampered by disagreements about how to translate experimental data from living species into quantitative models for predicting the performance of fossil hands. Such models are now beginning to take shape as new techniques are applied to the capture, management and analysis of data on kinetic and kinematic variables ranging from hand joint structure, muscle mechanics, and the distribution and density of bone to joint movements and muscle recruitment during manipulative behaviour. The systematic comparative studies are highlighting a functional complex of features in the human hand facilitating a distinctive repertoire of grips that are apparently more effective for stone tool making than grips characterising various nonhuman primate species. The new techniques are identifying skeletal variables whose form may provide clues to the potential of fossil hominid hands for one‐handed firm precision grips and fine precision manoeuvering movements, both of which are essential for habitual and effective tool making and tool use.     

锥形束CT研究正畸治疗前后的单侧后牙正锁合的髁突变化

目的 应用锥形束CT(CBCT)研究分析单侧后牙正锁合患者的双侧髁突形态及其在关节窝内位置的差异,以及正锁合解除后,患者髁突形态及位置的代偿性改建情况,以期为正畸临床诊疗提供早期依据。方法 选择单侧后牙正锁合18～28岁患者20例为实验组,同期选择安氏Ⅰ类轻度拥挤错颌18~30岁患者25例为对照组,进行面部锥形束CT拍摄,利用3D Examvision成像系统软件进行三维重建,描记测量髁突形态及位置的点和线,对7个不同的测量值进行统计学分析。结果 正畸治疗前,对照组左右两侧髁突形态及其在关节窝内的位置差异无统计学意义（P＞0.05）,实验组正锁合侧关节窝深度及髁突高度高于非锁合侧,差异具有统计学意义（t=13.271,t=15.278, P＜0.01）。正畸治疗正锁合并稳定保持3个月后,实验组正锁合侧关节前间隙、关节后间隙变化与治疗前相比差异具有统计学意义（t=5.524,t=-5.119,P＜0.01）,关节前间隙治疗前大于治疗后; 关节后间隙治疗前小于治疗后。实验组非锁合侧治疗前后髁突形态及其位置变化的差异无统计学意义（P＞0.05）。结论 单侧后牙正锁合患者双侧髁突形态及其在关节窝内的位置存在差异,矫治正锁合并稳定保持3个月后,锁合侧关节有向前下移动的趋势,而髁突形态并无明显变化。     

Antibody response to a major humanPneumocystis carinii surface antigen in patients without evidence of immunosuppression and in patients with suspected atypical pneumonia

IgG and IgM antibodies to a purified humanPneumocystis carinii surface antigen (gp95) were measured in 694 serum specimens from two different population groups using an EIA technique. In a population of 441 patients with no evidence of immunosuppression, the percentage of persons positive for IgG antibodies to gp95 was significantly lower in the age group 1 to 9 years (30 %, 23/77) compared to persons 10 to 19 years old (56 %, 49/88). In the age group 1 to 14 years there was a significant correlation between the percentage of persons with IgG antibodies to gp95 and age. In 106 consecutive patients under evaluation due to atypical pneumonia, 76 patients showed no change in the titre of antibodies toLegionella spp. orMycoplasma pneumoniae in two consecutive serum samples. Three of these 76 patients (4 %) demonstrated an increase in the level of IgG antibodies to gp95 in the paired samples. One of these patients had a verifiedPneumocystis carinii pneumonia, and the two others were elderly men in whom no microbiological diagnosis of the pneumonia was established. Thus, it is concluded that IgG antibodies to gp95 develop in the majority of nonimmunosuppressed persons before the age of 13. Furthermore,Pneumocystis carinii pneumonia should be considered in the differential diagnosis in patients suspected of having atypical pneumonia.     

B cells and the intestinal microbiome in time,space and place

The gut immune system is shaped by the continuous interaction with the microbiota. Here we dissect temporal, spatial and contextual layers of gut B cell responses. The microbiota impacts on the selection of the developing pool of pre-immune B cells that serves as substrate for B cell activation, expansion and differentiation. However, various aspects of the gut B cell response display unique features. In particular, occurrence of somatically mutated B cells, chronic gut germinal centers in T cell-deficient settings and polyreactive binding of gut IgA to the microbiota questioned the nature and microbiota-specificity of gut germinal centers. We propose a model to reconcile these observations incorporating recent work demonstrating microbiota-specificity of gut germinal centers. We speculate that adjuvant effects of the microbiota might modify permissiveness for B cell to enter and exit gut germinal centers. We propose that separating aspects of time, space and place facilitate the occasionally puzzling discussion of gut B cell responses to the microbiota.     

Further evidence of the absence of measles virus genome sequence in full thickness intestinal specimens from patients with Crohn's disease

Specimens of macroscopically inflamed and normal intestine along with mesenteric lymph nodes were obtained at resection from patients with Crohn's disease. The samples were systematically examined by RT-PCR-nested PCR targeting N, M and H gene regions of the measles virus genome. None of the samples examined gave any evidence of the persistence of measles virus in the intestine of Crohn's disease patients. The study supports previous findings produced by this laboratory and others using highly sensitive measles virus specific PCR diagnostic technology.     

Behavioral and anatomical evidence for electroreception in the bottlenose dolphin (Tursiops truncatus)

In the order of cetacean, the ability to detect bioelectric fields has, up to now, only been demonstrated in the Guiana dolphin (Sotalia guianensis) and is suggested to facilitate benthic feeding. As this foraging strategy has also been reported for bottlenose dolphins (Tursiops truncatus), we studied electroreception in this species by combining an anatomical analysis of “vibrissal crypts” as potential electroreceptors from neonate and adult animals with a behavioral experiment. In the latter, four bottlenose dolphins were trained on a go/no-go paradigm with acoustic stimuli and afterward tested for stimulus generalization within and across modalities using acoustic, optical, mechanical, and electric stimuli. While neonates still possess almost complete vibrissal follicles including a hair shaft, hair papilla, and cavernous sinus, adult bottlenose dolphins lack these features. Thus, their “vibrissal crypts” show a similar postnatal morphological transformation from a mechanoreceptor to an electroreceptor as in Sotalia. However, innervation density was high and almost equal in both, neonate as well as adult animals. In the stimulus generalization tests the dolphins transferred the go/no-go response within and across modalities. Although all dolphins responded spontaneously to the first presentation of a weak electric field, only three of them showed perfect transfer in this modality by responding continuously to electric field amplitudes of 1.5 mV cm⁻¹, successively reduced to 0.5 mV cm⁻¹. Electroreception can explain short-range prey detection in crater-feeding bottlenose dolphins. The fact that this is the second odontocete species with experimental evidence for electroreception suggests that it might be widespread in this marine mammal group.