A new method for scanning and transmission electron microscopy of synaptic vesicles isolated from the cerebral cortex.

Spheroid and flattened synaptic vesicles were isolated from the brain homogenate of guinea pigs by a modified purification method. For scanning and transmission electron microscopy, a simple dipping method of preparation was developed and used. The purest and richest fraction of synaptic vesicles was obtained from a 0.1 M sucrose fraction of density gradients. The pellets of synaptic vesicles were easily resuspended without aggregate after ultracentrifugation at 40,000 rpm for 5 min. The isolated synaptic vesicles were dispersed as a monolayer on the surface of a copper grid covered with Formvar membrane. Adequate contrast was obtained by metal impregnation of specimens and gold coating at magnifications as high as 100,000 times using an acceleration voltage of 25 to 40 kV. The specimens were fixed in 0.75% glutaraldehyde (0.1 M phosphate buffer, pH 7.3) and then postfixed in 1% osmium tetroxide. After dipping for 1 to 2 min each in tannic acid, phosphotungstic acid, lead citrate and uranyl acetate, they were dehydrated with graded ethanol and coated with gold by ion sputtering at 400 to 560 volts for 4 min. The preparation method is reported on and technical problems are discussed.

Renal vein thrombosis in stillborn infant of diabetic mother.

A second rare autopsy case of renal vein thrombosis in a stillborn female infant of a diabetic mother and the first after oxytocin induction is reported. Correlative light and electron microscopic studies were conducted. Extensive thrombosis from main to small cortical branches of the left renal vein was encountered causing hemorrhagic infarction of the left kidney. Newly formed hemorrhagic infarction and thrombosis of several small veins in the cortex of the right kidney were discovered. Hyperplasia of the pancreatic islets of Langerhans was observed. The literature was reviewed and the pathogenesis and clinical aspects were discussed.

A new type of mucolipidosis associated with hereditary thrombocytopathy and color blindness.

Autopsy findings of a 22-year-old Japanese male who showed the symptoms of both mucopolysaccharidosis and sphingolipidosis are reported. The patient had a gargoyle-like face, bone change with cherry-red spot and absence of mucopolysacchariduria, and moreover accompanied by hereditary thrombocytopathy and color blindness. Autopsy findings were almost the same as those of mucopolysaccharidosis, histochemically and electron microscopically. Unique findings were, however, present in the hepatocytes, another inclusion containing dense fine granuloreticular structures was found electron microscopically. Some foamy cells in the lymph nodes, liver including sinusiodal cells, bone marrow and spleen contained intracytoplasmic sudanophilic substance in the form of moderate electron dense globules by electron microscopy. The outstanding finding of the enzymatic activity was the decrease of beta-galactosidase in the liver and brain.

Electron microscopic study on the response of the normal canine brain to boron-neutron capture therapy.

The response of normal cerebral tissue of dogs to boron-neutron capture therapy by the currently available improved method was studied by electron microscopy. Peripheral blood capillaries of the neutron-irradiated area in the left cerebral hemisphere were compared with their counterparts in the shielded and non-irradiated right hemisphere. No ultrastructural changes, as those noted in classical method of boron-neutron irradiation by the improved technique of boron-neutron capture therapy. There was no swelling of endothelial cells, disappearance of cristae of mitochondria, increased pinocytosis, disappearance of ribosomes, enlargement of Golgi apparatus, or increased appearance of endoplasmic reticulum. Basement membrane was not disrupted and was uniform. Pericytes, synaptosomes, and other glial elements remained intact. In contrast to the old clinical trials up to 1961, the renewed boron-neutron capture therapy is regarded not to cause serious damage to the central nervous system.

Studies on preparation technique of human erythrocytes for clinical scanning electron microscopy.

Various methods of preparation were tested and modified in order to establish a proper method of preparing normal and pathological human erythrocytes for scanning electron microscopy. Morphological changes after various preparation techniques, such as echinocytosis, spherocytosis, elliptocytosis and knizocytosis were studied and evaluated statistically. The best method, so far obtained to preserve 99% of normal erythrocytes as biconcave discocytes, was that of venous blood without anticoagulants or acid-citrate-dextrose, washed with physiological saline at 37 degrees C, fixed in 0.75% glutaraldehyde in 0.1 M phosphate buffer, pH 7.3 (318 mosmol), postfixed in 1% osmium tetroxide, dehydrated with graded ethanol and amyl acetate, dried with critical point drying method, and coated with carbon and gold.