Mercuric Chloride Poisoning Due to Ingestion of a Stool Fixative

Abstract

We present a case of ingestion of a commonly used stool fixative containing 675?mg of mercuric chloride per 15 mL vial. Early chelator therapy with dimercaprol and aggressive hydration were initiated and the patient remained asymptomatic. Safety packaging of this product is recommended.     

Permeability studies of the labyrinth in the guinea pig placenta

Summary A surgical procedure was developed for cannulation of umbilical vessels in the guinea pig placenta. This approach allows an administration of electron opaque tracers, perfusion of fixatives and injection of corrosion casting compounds with minimal disturbance to the fetus and the placenta.Supported by grants from the Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET) and the Alexander von Humboldt Stiftung     

三种固定液对角蛋白反应的影响

本研究对13例人的正常涎腺经三种固定双固定后的组织标本进行了11种角蛋白单克隆抗体的免疫组化染色.其中5例腮腺和3例颌下腺分别同时用常规Formalin固定,Bouin’s液固定,Carnoy‘s液固定.染色采用ABC法,结果发现:Carnoy固定者,K_8、K_18、K_19和K_8.12的染色效果最好.其导管染色比Bouin‘s和Formalin固定者染色强而明确,尤其K_8和K_8.12不仅在导管中呈现强阳性,而且腺泡也呈阳性;而K_(17)和K_(L1)没有看出明显的染色差别;K_(14)、K_(10)、K_(13)、K_(17)、K_(20)的染色几乎全为阴性,与常规中性缓冲Formalin固定者结果一致.     

Liquid fixation of endometrial brush cytology ensures a well-preserved,representative cell sample with frequent tissue correlation

Endometrium was obtained by brushing 656 hysterectomy specimens with a MedScand cytobrush (Hollywood, FL) in order to evaluate linking an easy-to-use liquid fixative with brush-sampling of the endometrium, and to determine the fixative's operating characteristics when applied to brush-sampling the endometrium. Liquid-fixed brush-samples yielded 4 to 6 slides per case, and any one slide accurately represented the case diagnosis. Tissue fragments were incidentally collected by the brush in 524 cases (79.9%), were least often obtained from senile and weakly proliferative endometria, and were always obtained from high-grade endometrial hyperplasias and carcinomas. With tissue fragments obtained by brush-sampling, the diagnosis matched that of the hysterectomy endometrium. Cytology alone separated benign endometrium from high-grade atypical hyperplasia and carcinoma, showing that clinical decision-making can be based on endometrial brush cytology collected into a liquid fixative. Furthermore, the addition of tissue-fragment histology increased the diagnostic accuracy of the endometrial brushing procedure to 92.5% overall and 100% for high-grade atypical hyperplasias and carcinomas. At this juncture, we advocate endometrial brushing as a sensitive and generally specific case-finding technique; and perhaps as experience teaches us to distinguish low-grade nontypical hyperplasias from purely physiological changes of the endometrium, it may become accepted as a definitive diagnostic method. The advantages of examining a liquid-fixed suspension are that 1) because these preparations are homogeneous from slide to slide, with any one slide affording the same diagnosis as any other slide from the same case, the number of slides examined may be greatly reduced, and 2) tissue fragments can be used to quality-control the cytology diagnosis in the majority of cases, especially in cases of endometrial hyperplasia and carcinoma. Diagn Cytopathol 1996;14:367–373. © 1996 Wiley-Liss, Inc.     

Preservation of testicular tissue before fixation: Die Aufbewahrung von Hodengewebe vor einer Fixierung

An optimum evaluation of testicular tissue for diagnostic purposes is only possible by means of the semithin-section-technique, which implies fixation in glutaraldehyde/OsO4 followed by embedding in Epon. Since in clinical departments adequate fixatives are not always available, various storage conditions until further processing were tested. Testicular tissues from 5 men, who underwent orchidectomy, were stored for different periods in solutions of Ringer, 0.9% NaCl, Macrodex, Dextran, 1640 Medium or in a humid chamber either at room temperature or at 4 degrees C, subsequently fixed and then studied by means of light and electron microscopy. Under most conditions, primary spermatocytes and Leydig cells disintegrated rather quickly, while spermatogonia, spermatids and Sertoli cells without fixation were relatively well preserved up to 5 hrs. For optimum preservation the storage of testicular tissue in a humid chamber at 4 degrees C is recommended.     

Expression of estrogen and progesterone receptors in cytologic specimens using various fixatives

Estrogen and progesterone receptor reactivity may be useful in identifying possible primary sites of metastatic disease or directing therapy in tumors of the female genital tract, including breast, ovary, and endometrium. Various methods have been described for the immunocytochemical evaluation of estrogen receptor (ER) and progesterone receptor (PR) status of cytologic specimens but our results have been variable. We evaluated the effectiveness of various fixatives [cytospin collection fluid, Shandon, Pittsburgh, PA (SH); ethanol (ETH); and formalin (FOR)] for fixation of smears (SM) and cell block (CB) material. The percentage and intensity of tumor nuclei of SM, CB, and tissue sections (TS) stained for ER and PR by the avidin-biotin-peroxidase complex technique were compared. Samples were considered ER or PR positive when ≥20% of tumor nuclei were stained. The sensitivity of ER analysis of SMs and CBs in each fixative compared to formalin-fixed paraffin-embedded tissue sections were as follows, SM (SH) 88%, SM (ETH) 14%, CB (SH) 58%, CB (ETH) 43%, and CB (FOR) 70%. The sensitivity of PR determination on SMs and CBs was SM (SH) 71%, SM (ETH) 6.0%, CB (SH) 25%, CB (ETH) 33%, CB (FOR) 80%. These findings indicate that of the fixatives evaluated for ER analysis SMs fixed in SH provided the best results. For PR evaluation, CBs fixed in FOR gave the best results. Diagn Cytopathol 1996;15:78–83. © 1996 Wiley-Liss, Inc.     

Immunostaining of cell preparations: A comparative evaluation of common fixatives and protocols

Immunostaining of cytologic preparations has been beset by problems of inconsistency, high background staining, and the requirement of different fixatives for different antigens. This study sought to identify a universal fixative and a simple fixation protocol suitable for a wide range of tissue antigens commonly employed for cytologic diagnosis. In an analysis of 23 fixation protocols involving acetone, acetone/methanol, acetone/formalin, glutaraldehyde, ethanol, methanol, and formal saline, fixation in 0.1% formal saline overnight at 27°C followed by 10 min fixation in 100% ethanol produced the most consistent and optimal preservation of immunoreactivity which could be further enhanced by pre-treatment with microwaves for epitope retrieval. Blocking of endogenous peroxidase was not necessary with this fixation protocol. Provided the smears were well air-dried (for at least 14 hr) prior to immersion in formal saline, there was no need to employ adhesive-coated glass slides. The smears could be kept at 27°C (room temperature) for at least 7 days and at −70°C for 5 wk without loss of immunoreactivity as air-dried smears or after fixation in formal saline. One hundred percent acetone and 100% ethanol produced good morphology and immunoreactivity but a high level of background staining, whereas acetone-based mixtures resulted in inconsistent immunostaining. Diagn Cytopathol 1996;15:167–174. © 1996 Wiley-Liss, Inc.     

Comparison of current methods used to detect Cryptosporidium oocysts in stools

In this review all of the methods that are currently in use for the investigation of Cryptosporidium in stool material are highlighted and critically discussed. It appears that more qualifications and background knowledge in this field regarding the diagnosis of the Cryptosporidium parasite is required. Furthermore, there is no standardization for the protocols that are commonly used to either detect oocysts in faeces or to diagnose the Cryptosporidium infection. It is therefore necessary to initiate further education and research that will assist in improving the accuracy of the diagnosis of Cryptosporidium oocysts in the faecal micro-cosmos. Where ambient concentrations of oocysts are low in stool material, detection becomes a formidable task. Procedures for ring tests and the standardization of multi-laboratory testing are recommended. It is also necessary to enhance the routine surveillance capacity of cryptosporidiosis and to improve the safety against it, considering the fact that this disease is under diagnosed and under reported. This review is intended to stimulate research that could lead to future improvements and further developments in monitoring the diagnostic methodologies that will assist in harmonizing Cryptosporidium oocysts in stool diagnosis.     

Immunodetection of Parkin protein in vertebrate and invertebrate brains: a comparative study using specific antibodies

Parkin is an intracellular protein that plays a significant role in the etiopathogenesis of autosomal recessive juvenile parkinsonism. Using immunoblot methods, we found Parkin isoforms varying from 54 to 58 kDa in rat, mouse, bird, frog and fruit-fly brains. Immunocytochemical studies carried out in rats, mice and birds demonstrated multiple cell types bearing the phenotype for Parkin throughout telencephalic, diencephalic, mesencephalic and metencephalic brain structures. While in some instances Parkin-containing neurons tended to be grouped into clusters, the majority of these labeled nerve cells were widely scattered throughout the neuraxis. The topographical distribution and organizational pattern of Parkin within major functional brain circuits was comparable in both rats and mice. However, the subcellular localization of Parkin was found to vary significantly as a function of antibody reactivity. A consistent cytoplasmic labeling for Parkin was observed in rodent tissue incubated with a polyclonal antibody raised against the human Parkin protein and having an identical amino-acid sequence with that of the rat. In contrast, rodent tissue alternately incubated with a polyclonal antibody raised against a different region of the same human Parkin protein but having 10 mismatched amino-acid sequence changes with those of the rat and mouse, resulted in nuclear labeling for Parkin in rat but not mouse neurons. This difference in epitope recognition, however, was reversed when mouse brain tissue was heated at 80 degrees C, apparently unmasking target epitopes against which the antisera were directed. Collectively, these results show a high degree of conservation in the cellular identity of Parkin in animals as different as drosophilids and mammals and points to the possibility that the biochemical specificities of Parkin, including analogous functional roles, may have been conserved during the course of evolution.     

免疫细胞化学中不同固定剂对核蛋白检测效果的影响

目的：观察免疫细胞化学中不同固定剂对乳癌易感基因（brcal）和表皮生长因子（epidermal growth factor,EGF）在MCF－7细胞中的亚细胞分布的影响。方法：采用免疫细胞化学的方法,按照ABC试剂盒提供的操作步骤观察用不同固定剂及不同缓冲液时BRCA1和EGF在MCF－7细胞中定位情况。结果：如果细胞用3．7％的甲醛－PBS溶液固定,抗体稀释液及细胞冲洗液皆用PBS,则BRCA1和EGF均着色于细胞浆;若用3．7％的甲醛－PBS溶液固定细胞,而抗体稀释液及细胞冲洗液更换为含有0．1％吐温20或0．05％TritonX-100的PBS,则BPCA1和EGF均主要着色于细胞核。结果还表明,用纯甲醇、95％乙醇或冰醋酸：甲醇（1：3）固定细胞,无论是单用PBS或是含有化学去垢剂的PBS作为抗体稀释液及细胞冲洗液,BRCA1和EGF均主要着色于细胞核。结论：用免疫细胞化学技术检测细胞核蛋白时,最好选用甲醇作为固定剂。如果用甲醛固定细胞,建议用能给核膜打孔的化学去垢剂进一步处理细胞,否则会导致错误结果出现。