Dysfunction of duplicated pair rice histone acetyltransferases causes segregation distortion and an interspecific reproductive barrier

Postzygotic reproductive isolation, which results in the irreversible divergence of species, is commonly accompanied by hybrid sterility, necrosis/weakness, or lethality in the F1 or other offspring generations. Here we show that the loss of function of HWS1 and HWS2, a couple of duplicated paralogs, together confer complete interspecific incompatibility between Asian and African rice. Both of these non-Mendelian determinants encode the putative Esa1-associated factor 6 (EAF6) protein, which functions as a characteristic subunit of the histone H4 acetyltransferase complex regulating transcriptional activation via genome-wide histone modification. The proliferating tapetum and inappropriate polar nuclei arrangement cause defective pollen and seeds in F2 hybrid offspring due to the recombinant HWS1/2-mediated misregulation of vitamin (biotin and thiamine) metabolism and lipid synthesis. Evolutionary analysis of HWS1/2 suggests that this gene pair has undergone incomplete lineage sorting (ILS) and multiple gene duplication events during speciation. Our findings have not only uncovered a pair of speciation genes that control hybrid breakdown but also illustrate a passive mechanism that could be scaled up and used in the guidance and optimization of hybrid breeding applications for distant hybridization.

Optimization of rice panicle architecture by specifically suppressing ligand-receptor pairs

Rice panicle architecture determines the grain number per panicle and therefore impacts grain yield. The OsER1-OsMKKK10-OsMKK4-OsMPK6 pathway shapes panicle architecture by regulating cytokinin metabolism. However, the specific upstream ligands perceived by the OsER1 receptor are unknown. Here, we report that the EPIDERMAL PATTERNING FACTOR (EPF)/EPF-LIKE (EPFL) small secreted peptide family members OsEPFL6, OsEPFL7, OsEPFL8, and OsEPFL9 synergistically contribute to rice panicle morphogenesis by recognizing the OsER1 receptor and activating the mitogen-activated protein kinase cascade. Notably, OsEPFL6, OsEPFL7, OsEPFL8, and OsEPFL9 negatively regulate spikelet number per panicle, but OsEPFL8 also controls rice spikelet fertility. A osepfl6 osepfl7 osepfl9 triple mutant had significantly enhanced grain yield without affecting spikelet fertility, suggesting that specifically suppressing the OsEPFL6-OsER1, OsEPFL7-OsER1, and OsEPFL9-OsER1 ligand-receptor pairs can optimize rice panicle architecture. These findings provide a framework for fundamental understanding of the role of ligand-receptor signaling in rice panicle development and demonstrate a potential method to overcome the trade-off between spikelet number and fertility.

A genetic module at one locus in rice protects chloroplasts to enhance thermotolerance

How the plasma membrane senses external heat-stress signals to communicate with chloroplasts to orchestrate thermotolerance remains elusive. We identified a quantitative trait locus, Thermo-tolerance 3 (TT3), consisting of two genes, TT3.1 and TT3.2, that interact together to enhance rice thermotolerance and reduce grain-yield losses caused by heat stress. Upon heat stress, plasma membrane-localized E3 ligase TT3.1 translocates to the endosomes, on which TT3.1 ubiquitinates chloroplast precursor protein TT3.2 for vacuolar degradation, implying that TT3.1 might serve as a potential thermosensor. Lesser accumulated, mature TT3.2 proteins in chloroplasts are essential for protecting thylakoids from heat stress. Our findings not only reveal a TT3.1-TT3.2 genetic module at one locus that transduces heat signals from plasma membrane to chloroplasts but also provide the strategy for breeding highly thermotolerant crops.

[Relationship between auditory hallucination and regional homogeneity of functional magnetic resonance imaging in first-episode childhood and adolescence-onset schizophrenia]

Objective: To investigate the characteristics of regional homogeneity (ReHo) of the resting-state magnetic resonance imaging (fMRI) in first-episode childhood and adolescence-onset schizophrenia (CAOS) and to analyze the relationship between the severity of auditory hallucinations and ReHo. Methods: Seventy-nine cases of first-episode CAOS patients (case group) aged 10 to 16 were collected from October 2017 to December 2019 in the Second Affiliated Hospital of Xinxiang Medical University. There were 28 males and 51 females with a mean age of (14.1±1.3) years. And meantime, 32 healthy children matched with the patients in baseline data were selected as healthy controls (HCs). The patients with CAOS were divided into three groups according to the auditory verbal hallucinations (AVH) assessment of positive symptoms scale (SAPS): non-AVH group (0-1 point), 20 cases; mild-to-moderate AVH group (2-3 points), 36 cases; severe AVH group (4-5 points), 23 cases. The severity of psychiatric symptoms was evaluated using the Positive and Negative Syndrome Scale (PANSS). ReHo analysis was performed on the resting state fMRI scan data of all subjects. Covariance analysis (ages was used as a covariate) was performed between the case group and the HCs, and the three case groups were analyzed to find the different brain areas. Finally, covariance analysis (ages as a covariate) was performed on ReHo values between the case group and the HCs, and among the three groups of patients. Correlation analysis was conducted between the ReHo values in different brain regions and PANSS scores, as well as AVH scores. Results: Compared with the HCs, the decreased ReHo of patients were mainly located in the left superior frontal gyrus, right superior temporal gyrus, left central anterior gyrus, and right central anterior gyrus (all P<0.05). Besides, the ReHo deficits were in the right superior temporal gyrus, left middle frontal gyrus, precuneus lobe, and left central anterior gyrus among the three groups (all P<0.05). Moreover, the severe-AVH group showed decreased ReHo values in precuneus lobe compared with the non-AVH group (P<0.05), and showed decreased ReHo values in left middle frontal gyrus and left central anterior gyrus compared with the mild-to-moderate AVH group (both P<0.05). Furthermore, the ReHo in the right superior temporal gyrus and the left anterior central gyrus were negatively correlated with the AVH score (rs=-0.34, -0.32, P<0.05); and the positive symptom score was negatively correlated with the ReHo in the right superior temporal lobe (r=-0.23, P<0.05). Conclusion: Firstly, decreased ReHo is found in multiple brain regions in CAOS. Secondly, the occurrence of auditory hallucinations may be related to the abnormal activity of local neurons in the resting state. Consequently, Abnormal brain function may be the underlying neural basis for the first-episode CAOS.

[Brain gray matter volume alterations and cognitive function in first-episode childhood-and adolescence-onset schizophrenia]

Objective: To investigate the abnormal changes of gray matter volume and its relationship with cognitive function in first-episode childhood- and adolescence-onset schizophrenia. Methods: A total of 39 (aged 10-16 years) first-episode childhood- and adolescence-onset schizophrenia (patient group) were recruited from the inpatient departments of Second Affiliated Hospital of Xinxiang Medical University between 2014 and 2016, meanwhile, 30 age-, sex- and education years-matched healthy children and adolescents (control group) were also enrolled. All the subjects underwent 3.0 T magnetic resonance imaging (MRI) scan. The volume of gray matter in two groups was compared by voxel based morphometric method (VBM). MATRICS Consensus Cognitive Battery (MCCB) and the Stroop Color and Word Test (SCWT) were employed to evaluate the cognitive function of the two groups, and the relationship between the abnormal gray matter region and the cognitive function in the two group was analyzed. Results: Compared with the control group, brain gray matter volume in the right insula, left inferior frontal gyrus, the left limbic edge were significantly decreased (t=-5.303, -5.302, and -6.211; all P<0.05). Trail making test scores in the patient group were higher than those of the control group (t=3.22, P<0.01). However, scores of symbol coding, HVLT-R, BVMT-R, word fluency, digital span, maze test, word, color and color word were lower than those of the control group (t=-6.41, -5.42, -7.77, -5.59, -8.78, -6.99, -6.98, -6.47 and 4.84, all P<0.01). Pearson correlation analysis showed that the right insula was positively correlated with the BVMT-R and maze test scores, and the left inferior frontal gyrus was positively correlated with the maze scores in the patient group (r=0.32, 0.50 and 0.45, all P<0.05). The left inferior frontal gyrus was positively correlated with the digital span in control group (r=0.46, P<0.05). Conclusion: The first-episode childhood-and adolescence-onset schizophrenia exhibits abnormal changes of gray matter volume and cognitive function, and the pathophysiological mechanisms of a wide range of cognitive impairments may be related to abnormal volume changes of gray matter.

[Expressions and prognostic significance of PTEN and PD-1 protein in patients with classical Hodgkin's lymphoma]

目的

分析肿瘤免疫耐受信号通路的重要因子PD-1和PTEN在经典型霍奇金淋巴瘤（CHL）患者中的表达及其与患者临床特征和预后的相关性。

方法

回顾性分析2003年2月至2013年8月诊治的56例CHL患者的临床资料。采用免疫组织化学染色法检测CHL患者PD-1和PTEN蛋白的表达，采用原位杂交法检测EBV及EBV编码的小mRNA（EBER），并结合患者的临床特征与生存状态进行相关性分析。

结果

①56例患者中，男34例，女22例，中位年龄25（7~71）岁，PTEN阳性者11例（19.64%），PD-1阳性者14例（25.00%）。②PTEN和PD-1表达呈正相关（rs=0.320，P=0.016）；PTEN表达与Ann Arbor分期、IPS评分和有无大包块（≥5 cm）明显相关，PD-1仅与有无大包块相关（P值均<0.05）。③中位随访43（5~86）个月，多因素分析结果显示：年龄≥45岁（P<0.001）、IPS评分>2分（P=0.026）、EBER阳性（P=0.004）、PTEN蛋白高表达（P=0.035）是影响患者5年总生存的不良预后因素，也是影响5年无进展生存的不良预后因素（P值分别为0.007、0.014、0.002、0.024）。

结论

肿瘤免疫逃逸信号通路因子PTEN与CHL患者的预后相关，对CHL患者的预后判断有一定作用，同时也为CHL的免疫治疗提供了新思路和理论依据。

In situ heating TEM observations on carbide formation and α-Fe recrystallization in twinned martensite

The microstructural evolution of twinned martensite in water-quenched Fe–1.6 C (wt.%) alloys upon in situ heating was investigated using transmission electron microscopy (TEM). In the as-quenched samples, a high density of a body-centred cubic (bcc) {112} 〈111〉 -type twinning structure exists in the martensite structure. Upon in situ heating to approximately 200–250 °C, carbides (mainly θ-Fe₃C cementite) accompanying a detwinning process were observed only in the originally twinned region. The carbides were absent in the originally untwinned (twin-free) region. The experimental results have suggested that the formation of the carbides depends on the twinning-boundary ω-Fe metastable phase, which can be stabilised by interstitial carbon atoms. When the specimens were heated, the twinning-boundary ω-Fe(C) transformed into carbide (mainly θ-Fe₃C cementite) particles on the original {112} twinning planes. Further heating resulted in substantial recrystallisation of α-Fe fine particles, which formed immediately after martensite transformation. The results presented here should be helpful in understanding the microstructural evolution of various carbon steels.

Lath formation mechanisms and twinning as lath martensite substructures in an ultra low-carbon iron alloy

Lath martensite is the dominant microstructural feature in quenched low-carbon Fe-C alloys. Its formation mechanism is not clear, despite extensive research. The microstructure of an Fe-0.05 C (wt.%) alloy water-quenched at various austenitizing temperatures has been investigated using transmission electron microscopy and a novel lath formation mechanism has been proposed. Body-centered cubic {112}〈111〉-type twin can be retained inside laths in the samples quenched at temperatures from 1050 °C to 1200 °C. The formation mechanism of laths with a twin substructure has been explained based on the twin structure as an initial product of martensitic transformation. A detailed detwinning mechanism in the auto-tempering process has also been discussed, because auto-tempering is inevitable during the quenching of low-carbon Fe-C alloys. The driving force for the detwinning is the instability of ω-Fe(C) particles, which are located only at the twinning boundary region. The twin boundary can move through the ω ↔ bcc transition in which the ω phase region represents the twin boundary.

[Operative treatment of delayed acetabular fractures through combined anterior and Kocher-Langenbeck approaches]

Objective: To discuss the clinical outcomes of treating delayed acetabular fractures by combined anterior and posterior approach. Methods: A retrospective analysis was conducted of 31 delayed acetabular fractures from February 2012 to February 2017 in the First Affiliated Hospital of Chongqing Medical University, including 18 males and 13 females with age of 48.5 years(23 to 67 years) .The injury to the operation time was 35.9 days(22 to 183 days). Of these 31 cases, there were 6 cases of transverse and posterior wall fracture, 8 cases with anterior column+ posterior half transverse fracture, 12 cases with double column fracture and 5 cases of "T" type fracture according to Letournel-Judet classification.All fractures were treated combined anterior and Kocher-Langenbeck approaches, including 13 cases of ilioinguinal approach+ Kocher-Langenbeck(K-L approach), 4 cases of extensile acetabular approach, 7 cases of stoppa approach + K-L approach and 7 cases of side rectus femoris approach.Correlation was analyzed by Pearson correlation regression testing. Results: Follow up to August 2017, all patients were followed up with 36.0 months(from 6 to 55 months). As calculated, the restorational effect was positively with result of the X-ray film and the clinical effect(r=0.823, 0.856; both P<0.05). The evaluation was conducted with Matta's reduction criteria: there were 11 cases classified as anatomic reduction(35.5%), 13 cases as satisfactory reduction(41.9%), and 7 cases as unsatisfactory reduction(22.6%). Excellent and good rate was 77.4%. Functional reductions were categorized by the standard of Matta hip score: 8 excellent cases(25.8%), 11 good cases(35.5%), 8 fail cases(25.8%), and 4 poor cases(12.9%). Conclusion: The treatment of delayed acetabular fracture by combined anterior and posterior approach can fully exposure the anterior and posterior acetabular fcloumns, which is beneficial to the release and fixation of the old acetabular fractures.

[Fractional amplitude of low-frequency fluctuations in childhood and adolescence-onset schizophrenia: a resting state fMRI study]

Objective: To explore the whole brain activity features of childhood and adolescence-onset schizophrenia using resting state fMRI. Methods: A total of 63 childhood and adolescence-onset schizophrenia patients (patients group), admitted to the second affiliated hospital of Xinxiang Medical University from October 2013 to October 2015 and fulfilled our inclusion criteria, and 39 healthy controls with age, sex and education matched (control group) were enrolled, then a resting-state fMRI scan was conducted for each participant. Fractional amplitude of low-frequency fluctuations (fALFF) approach was used to explore the differences of resting-state brain function between patients and controls. Results: Compared with the healthy control group, patients group showed significantly decreased fALFF in left superior temporal gyrus and parietal lobe (MNI coordinate: x=-42, -57; y=-3, -21; z=-12, 9; voxels: 22, 32; t=-4.792 3, -5.269 7; Alphasim corrected, corrected P<0.05); patients group showed significantly increased fALFF in left frontal lobe and medial frontal gyrus, right superior frontal gyrus, Postcentral Gyrus, caudate, (MNI coordinate: x=-42, -21, 12, 27, 15; y=54, 39, 48, -18, 15; z=0, 21, 33, 30, 9; voxels: 12, 21, 17, 28, 18; t=4.784 8, 4.90 7, 4.861 5, 5.444 1, 4.270 4; Alphasim corrected, corrected P<0.05). When included age as a covariant, the analysis found that the brain region with significant fALFF change was the left thalamus with decreased fALFF (MNI coordinate: x=-6, y=-12, z=24; voxels: 9; t=-4.268 4; Alphasim corrected, corrected P<0.05) in patients group, while for other brain regions, there was no obvious change in the fALFF, compared with healthy group. Conclusion: Compared with control group, the results indicate that there are intrinsic brain activity abnormalities of some brain regions in childhood and adolescence-onset schizophrenia.

The development of a room temperature electron cyclotron resonance ion source (Lanzhou electron cyclotron resonance ion source No. 4) with evaporative cooling technology at Institute of Modern Physics

LECR4 (Lanzhou electron cyclotron resonance ion source No. 4) has been successfully constructed at IMP and has also been connected with the Low Energy Beam Transport (LEBT) and Radio Frequency Quadrupole (RFQ) systems. These source magnet coils are cooled through evaporative cooling technology, which is the first attempt with an ECR ion source in the world. The maximum mirror field is 2.5 T (with iron plug) and the effective plasma chamber volume is 1.2 l. It was designed to be operated at 18 GHz and aimed to produce intense multiple charge state heavy ion beams for the linear injector project SSC-Linac at IMP. In February 2014, the first analyzed beam at 18 GHz was extracted. During about three months' commissioning, some outstanding results have been achieved, such as 1.97 emA of O(6+), 1.7 emA of Ar(8+), 1.07 emA of Ar(9+), and 118 euA of Bi(28+). The source has also successfully delivered O(5+) and Ar(8+) ion beams for RFQ commissioning in April 2014. This paper will give a brief overview of the design of LECR4. Then, the latest results of this source at 18 GHz will be presented.

Application of evaporative cooling technology in super-high power density magnet

Evaporative cooling technology utilizes phase-change heat transfer mode to achieve the cooling for heating equipment. The heat transfer capacity of evaporative cooling technology is far more than air or water cooling technology. The Electron Cyclotron Resonance ion source magnet is a typical super-high power density magnet, and the evaporative cooling technology is an ideal cooling method for the coils of magnet. In this paper we show the structure and process of coils and the special design of flow channels of coolant for an experiment magnet model. Additionally, the heat transfer circulation is presented and analyzed. By the finite element method, the flow channels are optimized to rationally allocate coolant and to reduce the temperature of coils. For the experiment model, the current density of copper wire of coils is 19 A/mm(2), and the coil-windows current density is larger than 12 A/mm(2). The max temperature of coils is below 80 °C, and the total heat is about 200 kW.

Progress of a room temperature electron cyclotron resonance ion source using evaporative cooling technology at Institute of Modern Physics

A new room temperature ECR ion source, Lanzhou Electron Cyclotron Resonance ion source No. 4 (LECR4, previously named DRAGON), is under intense construction at Institute of Modern Physics. LECR4 is designed to operate with 18 GHz microwave frequency. The maximum axial magnetic fields are 2.3 T at injection and 1.3 T at extraction, and the radial field at the plasma chamber wall of 76 mm inner diameter is 1.0-1.2 T. One of the unique features for LECR4 is that its axial solenoids are winded with solid square copper wires which are immersed in a kind of special evaporative cooling medium for cooling purpose. Till now, a prototype of the cooling system has been successfully constructed and tested, which has demonstrated that the cooling efficiency of the designed system could meet the requirements of LECR4 under the routine operation conditions. All the main components of the ion source have been completed. Assembly and commissioning is ongoing. The latest developments and test results will be presented in this paper.

Immunological study of allogeneic mesenchymal stem cells during bone formation

Autologous mesenchymal stem cells (MSCs) are limited in their clinical application because tissue-engineered bone cannot be pre-fabricated. Allogeneic MSCs are readily available but carry the risk of transplant rejection. It is not yet clear whether allogeneic MSCs can induce a rejection response during bone formation. In this study, two strains of genetically unmatched mini-pigs were used as experimental animals to study the immunological changes in MSCs in vitro and in vivo when generating bone. Mini-pig MSCs showed low immunogenicity during osteogenesis both in vitro and in vivo, indicating that allogeneic MSCs had little or no immunogenicity in osteosis. In conclusion, allogeneic MSCs are an important source of seed cells for the tissue engineering of bone. This favours the clinical application of pre-constructed tissue-engineered bone.

Subcellular membrane impairment and application of phospholipase A2 inhibitors in endotoxic shock

The study aims at elucidating the mechanism involved in the cell dysfunction or impairment and the protective effects of phospholipase A2 (PLA2) inhibitors in endotoxin shock. Thirty-four rabbits were divided randomly into four groups: (1) normal control group (NC, n = 6), receiving saline intravenously; (2) endotoxin shock group (ES, n = 12), receiving 3 mg/kg of E. coli endotoxin; (3) chloroquine pretreated group (CQ, n = 8), receiving 3 mg/kg of chloroquine 3 min before endotoxin injection and (4) chlorpromazine pretreated group (CPZ, n = 8), receiving 0.3 mg/kg of chlorpromazine 30 min before endotoxin injection. Hepatic mitochondria were extracted either 8 h after commencement of the experiment or when the animals died for detecting PLA2 activity, membrane fluidity, membrane bound succinate dehydrogenate (SDH) and malondialdehyde (MDA). Mitochondria of the lung, heart and kidney were also used for detection of the membrane fluidity. It was revealed that the survival rate of 8 h was 100% (NC), 58% (ES), 87.5% (CQ) and 75% (CPZ), respectively. Mean arterial pressure (MAP) dropped soon after endotoxin injection and descended continuously afterwards in the ES group (P < 0.01). Fluorescence polarization, microviscosity and anisotrophy with a DPH probe were elevated above control levels (P < 0.01). SDH was decreased obviously following endotoxin infusion (P < 0.01). Chloroquine and chlorpromazine, serving as PLA2 inhibitors, could abate cellular dysfunction and increase survival rate. It is proposed that PLA2 plays a pivotal role in cellular injury in endotoxin shock. PLA2 inhibitor might serve as a useful adjunct in combating sepsis and shock.

Enhanced immunogenicity in mice with hepatitis B vaccine complexed to human hepatitis B immunoglobulin

Purified human hepatitis B immunoglobulin (HBIG) was complexed to plasma derived hepatitis B vaccine (HBVac) at different concentrations and used to immunize Balb/c mice. An enhanced humoral immune response was observed when HBVac was complexed to HBIG in excess of antigen, compared to that immunized with the vaccine alone. Proliferation of splenic lymphocytes was detected when mice were immunized with HBIG complexed to HBVac (0.2-1 microgram), whereas in mice immunized only with HBVac at one microgram, no lymphocyte proliferation was observed. The enhanced immunogenicity of HBIG: HBVac is T cell dependent. The importance of using critical ratio of HBIG and HBVac is indicated, and future application of this complex for vaccination of low- or nonresponders to the present HBVac, as well as for treatment of chronic hepatitis B patients is discussed.

Giant solitary synovial chondromatosis

The purpose of this report is to describe giant solitary synovial chondromatosis, a previously unrecognized feature of synovial chondromatosis that may histologically and radiographically mimic a malignant neoplasm. Giant solitary synovial chondroma is an intra- and/or extraarticular lesion measuring over 1 cm in size and sometimes as large as 20 cm. The radiographic appearance is that of a large, well-marginated mass either of irregular feathery calcification from coalescence of multiple small synovial chondromas, or a rounded calcified mass from the growth of a single synovial chondroma. Radiographically, giant solitary synovial chondromatosis may appear similar to chondrosarcoma and parosteal osteosarcoma.

MRI of extraskeletal osteosarcoma

We report four cases of extraskeletal osteosarcoma of the thigh to illustrate MRI findings of this rare neoplasm. Calcifications or osteoid material were not discernible in these tumors on MRI or conventional radiography. Three tumors were well demarcated on MRI and corresponded to pseudoencapsulation on radiologic-pathologic correlation. These three tumors were heterogeneous in appearance and were hyperintense to muscle on T1-weighted imaging and demonstrated high signal intensity on T2-weighted imaging. In the fourth tumor, which occupied almost the entire thigh, MRI before and after intravenous gadopentetate dimeglumine administration revealed cystic, hemorrhagic, and solid components. Pathological examination revealed a cystic hemorrhagic cavity containing necrotic and viable tumor and a large solid tumor component. The MRI findings in extraskeletal osteosarcoma are non-specific. However, in the appropriate age group the differential diagnosis of a soft-tissue mass in the thigh should include extraskeletal osteosarcoma, even in the absence of radiographically discernible calcifications or osteoid material within the soft-tissue mass.

Diagnosis of eosinophilic granuloma of bone by fine-needle aspiration with concurrent institution of therapy: a cytologic, histologic, clinical, and radiologic study of 27 cases

Twenty-seven patients with eosinophilic granuloma (EG) of bone seen at our institution between 1979 and 1991 underwent fine-needle aspiration (FNA) with or without concurrent Tru-Cut biopsy. The 16 males and 11 females ranged in age from 2 1/2 to 61 years (median, 10 yr). Twenty-four patients had monostotic lesions. The clinicoradiologic differential diagnosis included osteomyelitis and Ewing's sarcoma (young patients) and primary and metastatic malignancies (older patients). Twenty-four of 28 FNAs (one patient had two FNAs) were diagnostic of EG, and 10 cases were diagnosed by FNA alone. Smears in these cases showed histiocytes, often with grooved or infolded nuclei, and abundant eosinophils. Multinucleated giant cells, foamy histiocytes, neutrophils, lymphocytes, and plasma cells were present in variable numbers. Four FNAs were misdiagnosed: two as osteomyelitis where smears contained abundant neutrophils, sparse eosinophils, and histiocytes misinterpreted as foamy histiocytes, and two as metastatic carcinoma (in adults) where histiocytes in a scant specimen (one case) and skin appendiceal structures without lesional tissue (one case) were misinterpreted. These cases were correctly diagnosed on repeat FNA (one case), Tru-Cut (two cases), or excisional biopsy (one case); however, three cases diagnosed by FNA had nondiagnostic concurrent Tru-Cut biopsies. Treatment consisted of intralesional injection of 125 mg of methylprednisolone (22 cases). Progressive or complete healing of all lesions occurred. FNA is a rapid and useful technique for the immediate diagnosis of EG that allows concurrent institution of therapy.

Chondrosarcoma: MR imaging with pathologic correlation

Magnetic resonance (MR) images of 21 surgically confirmed chondrosarcomas were retrospectively reviewed in conjunction with plain radiographs and computed tomographic scans and correlated with pathologic findings. The tumors appeared lobulated, and signal intensity, as analyzed visually (intermediate on T1-weighted, high on T2-weighted images), was similar for all lesions, regardless of pathologic type. Size of lesion was not an indicator of grade. The appearances of mesenchymal and dedifferentiated chondrosarcomas mimicked that of conventional chondrosarcoma. Extraskeletal chondrosarcoma was visualized as a lobulated soft-tissue mass. In all cases, MR imaging accurately depicted intraosseous and soft-tissue extent of tumor noted at surgery and pathologic examination. Histologic type or grade of chondrosarcoma generally cannot be characterized on the basis of visual analysis of signal intensity noted on routine MR images. However, MR imaging is excellent for exact delineation of tumor extent.

Down syndrome. Clinical review of ocular features

A total of 187 medical records of Down syndrome individuals over a 10-year period were reviewed retrospectively for strabismus, myopia, hyperopia, astigmatism, nystagmus, cataract, glaucoma, and other significant eye findings. This study showed that a higher proportion of these individuals than reported in previous studies had strabismus (57%). Refractive errors of myopia (22.5%), hyperopia (20.9%) and astigmatism (22%) were common. The primary care physician needs to be aware of the specific eye problems of Down syndrome individuals so that he or she may initiate or refer the patient for appropriate ophthalmologic care, because most of the eye findings in Down syndrome are treatable. Significant visual loss, a usually avoidable event in Down syndrome, should occur rarely.

Visual pathway abnormalities in albinism and infantile nystagmus: VECPs and stereoacuity measurements

The visual pathway of albinos is characterized by abnormal optic nerve fiber decussation with increased contralateral projection. This results in hemispheric asymmetry of monocular visually evoked cortical potentials (VECPs) and may be related to lack of stereopsis. Flash VECP, Random Dot E (RDE), and Titmus stereotest data were collected from 40 nystagmus patients, 19 albino and 21 with normal pigmentation. Data were compared with results obtained from 19 race- and age-matched normal subjects. All albino patients demonstrated hemispheric VECP asymmetries exceeding +/- 2.0 standard deviations from the normal mean, showing either delayed ipsilateral P latency (88%), reduced ipsilateral P amplitude (59%), or both (47%). None of the normally pigmented infantile nystagmus patients exceeded this criteria on either VECP measure. While only one albinotic patient showed positive RDE and stereofly results, 86% of normally pigmented nystagmus patients passed the stereofly test, 60% demonstrated 400 sec (Titmus) stereopsis, and 66% showed positive RDE results. These findings reveal that normally pigmented infantile nystagmus patients have variable degrees of stereopsis and no excessive abnormalities of optic nerve fiber decussation as evidenced by flash VECP. Additionally, this study verifies visual pathway abnormalities and the lack of stereopsis in albino nystagmus patients.

Association of microneme antigens of Plasmodium brasilianum merozoites with knobs and other parasite-induced structures in host erythrocytes

The localization of Plasmodium brasilianum antigens, common to merozoite micronemes and parasite-induced structures in the host erythrocyte, was determined by means of immunogold electron microscopy and monoclonal antibodies directed against blood stages of this parasite. All monoclonal antibodies reacted with micronemes. In addition, some reacted with either knob protrusions or caveolae of the host erythrocyte membrane; one reacted with a parasite-derived antigen present in the erythrocyte cytoplasm. Gold particles appeared over the membranes of ring-infected cells before the appearance of knobs and caveolae. We hypothesize that at least some knob- and caveolae-associated antigens of P. brasilianum are inserted into the erythrocyte membrane at the time of merozoite invasion.

Nasal-oropharyngoscopy: a simple test to evaluate lacrimal duct function in children

Obstruction of the lacrimal drainage system is a common problem in pediatric ophthalmology. We describe a simple office test which allows the patency of the lacrimal drainage system to be visualized.