红鲫与湘江野鲤杂交的受精细胞学研究

红鲫成熟卵直径680—720μm;卵膜孔为精子入卵的唯一通道,包括前庭和精孔管两部分;精孔管内径约5μm。湘江野鲤精子头部直径约2.5μm。在通常情况下,红鲫卵为单精受精。尽管红鲫与湘江野鲤不同属,但杂交仍具有正常的受精细胞学程序。红鲫卵子处于第二次成熟分裂中期接受湘江野鲤精子入卵,精子入卵5min后,出现明显的精子星光;15min后,雄性原核及雌性原核形成;25min后,雌、雄性原核融合;30min后、开始卵裂,发现1个受精卵切片上有4个即将融合的原核,这可能是由于双精受精所致。     

普通小麦与长穗偃麦草杂种及其衍生材料的细胞遗传学特性

对十倍体长穗偃麦草(Thinopyrum ponticum)与普通小麦杂交F1及其与普通小麦回交BC1F1的形态学和细胞学特性进行了分析。结果表明,长穗偃麦草与普通小麦‘兰考矮早八’衍生F1(‘兰考小偃麦’)的根尖细胞染色体数为56条;花粉母细胞减数分裂中期Ⅰ染色体构型平均值为19.81Ⅰ+15.78Ⅱ+0.75Ⅲ+0.59Ⅳ;基因组荧光原位杂交(GISH)显示,兰考小偃麦中含有35条完整的长穗偃麦草和21条小麦染色体。‘兰考小偃麦’/‘科育818’和‘兰考小偃麦’/‘Cp02-3-5-5’杂交F1的根尖细胞染色体数及其所遗传的长穗偃麦草染色体数分别为50~52和16~22条,且存在染色体易位;花粉母细胞减数分裂中期Ⅰ平均染色体构型为14.54Ⅰ+17.40Ⅱ+0.55Ⅲ+0.14Ⅳ,平均49.4%的细胞出现多价体(三价体或四价体)。这些材料为创造小麦-长穗偃麦草新种质奠定了基础。     

12种酢浆草属植物核型分析

【目的】为了从细胞学角度明确12种酢浆草属（Oxalis）植物核型特征与亲缘关系,探究酢浆草属植物染色体的多样性,进一步为酢浆草种质资源鉴定与杂交育种亲本选择提供参考。【方法】应用根尖压片法对酢浆草属12个物种植物有丝分裂中期的染色体形态、数目及其核型进行观察分析。【结果】结果表明：（1）7个物种的染色体数目为首次报道,5种已报道物种中,兔耳酢浆草（O. fabaefolia）和黄花酢浆草（O. pes-caprae）染色体数目与前人报道一致,其余3种,与先前报道存在差异,其中2n=26为酢浆草属植物中首次报道的染色体数目,共发现7种染色体基数,其中x=13为首次报道,倍性范围从2x~6x;实际染色体大小范围为0.27~2.23 μm,着丝点位置为中部着丝点区（m）和亚中部着丝点区（sm）,核型类型共4种,核型不对称系数范围为56.31%~65.40%。（2）12种酢浆草属植物中兔耳酢浆草最为进化,扁平酢浆草（O. compressa）最为原始。（3）根据染色体核型相似性可将12个酢浆草属植物划分为4组。【结论】研究认为,12个酢浆草属物种具有广泛的核型多样性,核型分类结果与前人形态学分类不完全一致。     

Thin layer compared to direct smear in thyroid fine needle aspiration

The efficacy of preparing thyroid fine needle aspirations (FNAs) by the thin layer as opposed to the direct smear method has not been evaluated sufficiently in a regional laboratory setting. At the Foothills Hospital (Calgary, Canada), the method of processing thyroid FNAs was changed from direct smear to thin layer in January 1996. The results of 327 patients who had direct smear from 1994 to 1995 were compared to 401 who had thin layer between 1996 and 1997. While there were no significant differences across a broad range of quality indicators, thin layer showed a trend towards a higher proportion of true benign diagnoses (31% vs 24%), a lower proportion of inadequate specimens (41% vs 50%) and, most importantly, a lower false negative rate (3% vs 9%). In conclusion, the changeover to thin layer did not compromise the interpretation of thyroid FNAs.     

Biliary brushing cytology

Biliary tract brush specimens are fast becoming the method of choice in the evaluation of patients who present with biliary tract strictures. Although the specificity is high, sensitivity rates for the detection of malignancy are generally low on cytological sampling. New liquid-based preparations and ancillary tests have emerged with the intent of addressing this issue. This review focuses on the current schemata used in the diagnosis of biliary tract lesions and the current available modalities which aid in the diagnosis of cholangiocarcinoma.     

Cytology of colorectal adenomas

A study of the cytological appearances of benign and malignant colorectal adenomatous polyps is reported. The aim of the study was to characterize the cytological features of adenomatous polyps and predict the likelihood of malignancy using cytology. A five grade classification of colorectal cytology has been developed and the characteristic appearances of cells from adenomatous polyps are described. The reproducibility of cytological diagnosis based on this classification has been tested in 120 smears from normal mucosa and adenomatous polyps (including polyp cancers). Correlation with histology was achieved in 88% and correlation of the cytological diagnosis between two observers was achieved in 84%. We conclude that cytology can be used reliably as an adjunct to histology in the assessment of malignancy of adenomatous polyps.     

Transthoracic fine needle aspiration cytology of lung for suspected malignancy: an audit of cytological findings with histopathological correlation

Transthoracic fine needle aspiration cytology (TFNAC) is an invasive procedure and should therefore be subject to regular review. We report an audit of TFNAC from 146 patients. One hundred and thirty‐six samples (93%) were adequate and 86 were malignant, 16 suspicious and 34 contained no malignant cells. TFNAC was the sole means of diagnosis of malignancy in 55 patients. However, further pathological data were available in 58 of the adequate samples; TFNAC was malignant in 31, suspicious in eight and contained no malignant cells in 19. All malignant TFNAC were confirmed (absolute sensitivity=85%; positive predictive value=100%); as were five of eight with suspicious cytology. Of 19 patients with negative TFNAC, nine were subsequently found to have a malignancy (specificity=68%).     

Human papillomavirus infection in the cervix of pregnant females in Hong Kong

Routine cytological examination and HPV-DNA probing were performed on cervical cells obtained from 215 pregnant Chinese females. The procedure utilized the specific binding of a mixture of complementary [32P]-labelled RNA probes to membrane-bound target HPV DNA types 6, 11, 16, 18, 31, 33 and 35. Positive results for HPV-DNA were obtained in 11/215 (5%) of the cases. The cervical smears were routinely processed and in 3/215 (1.5%) cases a cytological diagnosis of wart virus infection was made. All three were included in the 11 probe-positive cases. Using similar molecular biological techniques, pregnant Western females have an incidence of HPV infection of the cervix which is up to five times that of the present series. This is an unexpected finding in view of the fact that the incidence of cervical cancer is higher in Chinese women than American women.     

Protein bodies of seeds: Ultrastructure,biochemistry, biosynthesis and degradation

Typical organelles for protein storage occur in seeds, protein bodies are found in haploid, diploid or triploid tissues and are single membrane bound. In some plants, they exhibit inclusions (globoid and crystalloid), but not in Gramineae endosperm or in Leguminosae cotyledons. A relationship between species and protein body ultrastructure can be put forward. The chemical composition is based mainly on storage proteins and phytic acid but, hydrolytic enzymes(protease and phytase), cations and ribonucleic acids are also present. Other minor biochemical components include oxalic acid, carbohydrates (excluding starch) and lipids. The locations of the storage proteins, enzymes and phytin are described. Protein body ontogeny during seed maturation has given rise to much controversy: are they plastidic or vacuolar? Recent studies on the location of proteosynthesis show that protein bodies are probably synthesized in endoplasmic reticulum lumen and that the Golgi apparatus plays an important role in storage protein synthesis. During germination protein bodies swell and fuse, giving rise to the cell central vacuole, while the integrity of the membrane is maintained. Protein bodies may be considered as being an example of tonoplast origin from endo-plasmic reticulum.     

Benign follicular thyroid lesions versus follicular variant of papillary carcinoma: differentiation by architectural pattern

Differentiation between benign and malignant follicular lesions is one of the difficult diagnostic areas in thyroid fine needle aspiration (FNA). Nuclear criteria are usually used to distinguish between them. In this study the microarchitectural pattern of common benign follicular lesions, namely nodular hyperplasia (NH) and follicular adenoma (FA) were analysed in comparison with those of follicular variant of papillary carcinoma (FVPC) in order to aid in their differentiation. The FNA smears of histologically proven cases of FVPC, NH and FA were reviewed and compared. The microarchitectural features of FVPC, NH and FA were described. Three cytological features--multi-layered rosettes, branching monolayered sheets and balls of thick pinkish colloid--were exclusively observed in FVPC. Hyperplastic papillae with intact follicles and colloid were frequently seen in NH, 83% and 100%, respectively. Albeit less frequently, they were also noted in FVPC, 25% and 75% of cases, respectively. These overlapping features make the distinction between FVPC and NH sometimes difficult; however, assessing the smears for the specific features of FVPC may help in their differentiation. None of the aforementioned microscopic findings with the exception of the seldom presence of colloid were documented in FA. The crowded clusters of follicular cells were seen both in FA and FVPC; however, they were complex and branching in the latter and round to oval in the former. Finally, smears with good recovery of material are indispensable for the identification of these helpful microarchitectural patterns.