植物胚囊发育的细胞与分子生物学研究

综述了植物胚囊发育的细胞及分子生物学研究进展 ,并对该领域的进一步研究和发展提出了问题     

罗汉果胚轴培养再生植株及其细胞学观察

以罗汉果胚轴为外植体,探讨了不同培养基对胚轴不定芽再生的影响,并进行了再生不定芽的细胞学观察.结果表明:胚轴在改良的MS+4 mg.L-16-BA+1 mg.L-1IAA的固体培养基中,不定芽分化平均每瓶高达7.6个;单芽段一步生根成苗.细胞学观察结果表明:不定芽和体细胞胚起源于胚轴形成的愈伤组织表层;不定根起源于愈伤组织内部.     

Pulmonary function measurements immediately after exercise are correlated with neutrophil percentage in tracheal aspirates in horses with poor racing performance

Inflammatory airway disease (IAD) is common in racehorses, and is a cause of wastage in the industry. IAD has been diagnosed by measurement of percent neutrophils (N%) in tracheal aspirates (TA). The aim of this study was to investigate whether spirometric indices of pulmonary function were correlated with N% in TAs. Limits to breathing were measured by analyses of relationships between relative times and relative respiratory gas flows during inspiration and expiration in individual breaths recorded after exercise. Horses with higher N% had significantly lower relative gas flows at the same relative times during inspiration and expiration, suggesting a limit to breathing. These findings confirm a physiological basis for the measurement of N% in TA after exercise for diagnosis of IAD. Spirometric pulmonary function testing using analyses of individual breaths after exercise has application for assessment of pulmonary function and poor exercise performance.     

龙牙楤木体细胞胚胎发生的细胞组织学研究

以龙牙楤木幼芽为外植体,在改良MS培养基上以体细胞胚胎发生获得了再生植株并对其发生过程进行了组织切片和扫描电镜观察。结果表明:龙牙楤木体细胞胚胎发生为典型的单细胞起源。其胚性原始细胞既有内起源,又有外起源。     

EFFECTS OF METRIZAMIDE MYELOGRAPHY ON CEREBROSPINAL FLUID ANALYSIS IN THE DOG

The effect of metrizamide myelography on the composition of cerebrospinal fluid (CSF) was studied. Seven dogs received an intracisternal injection of metrizamide. An intracisternal puncture was performed in three additional dogs that did not receive metrizamide. CSF was collected before myelography and 24, 72, and 144 hours after myelography from all dogs. A significant increase in the percentage of neutrophils (p<0.05) and a pleocytosis noted 24 hours after myelography (p<0.02) were attributed to the effect of metrizamide. Significant increases in total protein concentration (p<0.001) and erythrocyte count (p<0.05), and a decrease in the percentage of small mononuclear cells (p<0.01) were attributed to repeated intracisternal puncture. No significant changes were observed for CSF creatine phosphokinase activity or the percentage of large mononuclear cells.     

Computerized Cytomorphometric Analysis of Nuclear Area,Nuclear Perimeter and Mean Nuclear Diameter in Spontaneous Canine Mammary Gland Tumours

Fifty-two spontaneous canine mammary gland tumours (fibroadenomas (n = 8), tubulopapillary carcinomas (n = 9), solid carcinomas (n = 6), anaplastic carcinomas (n = 7), fibrosarcomas (n = 9), liposarcomas (n = 9) and osteosarcomas (n = 4) were analysed by computer-assisted nuclear morphometry in Hemacolor-stained cytological specimens. Computerized cytomorphometry was performed and the nuclear area, nuclear perimeter and mean nuclear diameter of investigated tumours were assessed. A minimum of 100 nuclei per lesion were examined. The statistical analysis revealed statistically significant differences between benign and malignant neoplasms. The results indicated that computer-assisted nuclear morphometry could be used as an additional method for differentiation of benign from malignant canine mammary gland tumours in cytological specimens.     

Liver aspirate from a Shar Pei dog

A 5-year-old, neutered male, Shar Pei dog was presented with weight loss, anorexia, lethargy, stranguria, and distal limb edema. Clinicopathologic abnormalities included anemia, an inflammatory leukogram, azotemia, icterus, urinary tract infection, and hepatomegaly with a markedly hypoechoic liver. Cytologic findings in a fine-needle aspirate of the liver included large amounts of amorphous, pink, extracellular matrix between hepatocytes. The amorphous material was congophilic using Congo red stain on a hepatic cytology specimen and green birefringent areas were observed under polarized light, confirming the presence of amyloid. The dog was euthanized and a necropsy was done. Histopathologic evaluation using H&E and Congo red staining confirmed amyloid deposits within the liver, kidneys, intestinal vessels, pancreas, and mesenteric ganglia. Immunohistochemical staining of liver and kidney sections using anti-AA amyloid and anti-P component antibodies confirmed the presence of AA amyloid. In this case, we demonstrated that Congo red staining and polarized light microscopy are a useful diagnostic technique in cytologic specimens of suitable thickness for confirming the presence of amyloid.     

Coelomic mass in a rock dove (Columba livia)

A 15-year-old domestic rock dove (Columbia livia) was presented to the Service de Médecine Zoologique of the Université de Montréal with a 10-day history of lethargy and chronic weight loss of 1-year duration. Ultrasonographic evaluation of the coelomic cavity revealed the presence of effusion and a well-defined mass containing variably sized hypoechoic nodules of unknown origin. Cytologic evaluation of fine-needle aspirates of the mass indicated a malignant epithelial tumor consisting of round cells arranged individually and in clusters, with large nuclei, prominent nucleoli, moderate anisocytosis and anisokaryosis, atypical mitoses, occasional binucleation and multinucleation, and large numbers of ruptured cells. A diagnosis of seminoma was established on histologic sections obtained at necropsy. The cytologic features of this tumor were similar to those of canine seminomas except for the presence of lymphocytes, which were not observed in significant numbers in cytologic smears or histologic sections. Seminoma should be included in the differential diagnosis for a space-occupying mass causing organ displacement within the coelomic cavity of a male bird.     

Microscopic detection of Leptospira bacterial organisms in urine sediment from a young dog with leptospirosis and a review of the pathobiology and diagnosis of canine leptospirosis

Samples collected from an 11-month-old Dachshund-mix dog with a history of acute azotemia, fever, and enlarged and irregular kidneys were received at the Colorado State Veterinary Diagnostic Laboratory (CSU VDL). The submitting veterinarians were concerned about lymphoma versus acute nephritis/pyelonephritis. The CSU clinical pathology laboratory received urine for urinalysis and kidney aspirates for cytologic evaluation. Urine had also been submitted for aerobic culture and Leptospirosis PCR, and serum was submitted for Lepto-5 microscopic agglutination testing (MAT). Upon examination of a wet mount of the urine sediment, technical staff noted “vibrating” clumps of granular-appearing material throughout the slide, which prompted the preparation of a stained sediment slide for pathologist review. Very small, faintly staining organisms were observed, and an attempt was made to picture-match these with published reports of Leptospira in dog urine, but none could be found. In addition, some references claimed that Leptospira organisms are not seen in urine with light microscopy. The suspicion that these organisms were Leptospira sp. was supported by the MAT results and later confirmed by PCR. The organisms subsequently exhibited strong positive immunolabeling for the Leptospira antigen. This case report provides a searchable record of Leptospira organisms visualized by routine light microscopy in dog urine during natural infection and a review of canine leptospirosis pathobiology and diagnosis.