Spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder characterized by degeneration of motor neurons of the spinal cord. Three different forms of childhood SMA have been recognized on the basis of age at onset and clinical course: Werdnig-Hoffmann disease (type-1), the intermediate form (type-II) and Kugelberg-Welander disease (type-III). A gene termed 'survival of motor neuron' (SMN) has been recognized as the disease-causing gene in SMA. SMN encodes a protein located within a novel nuclear structure and interacts with RNA-binding proteins. To elucidate the molecular mechanism underlying the pathogenesis of the disease, we examined the expression of the SMN gene in both controls and SMA patients by western blot and immunohistochemical analyses using antibodies raised against the SMN protein. The present study shows a marked deficiency of the SMN protein in SMA.

Correlation between severity and SMN protein level in spinal muscular atrophy.

现代神经科学研究技术 = Modern techniques in neuroscience research

Unusual cytoskeleton abnormalities were found in the brains of 28 individuals afflicted with adult onset dementia. Most conspicuous were small spindle-shaped argyrophilic grains loosely scattered throughout the neuropil. Additionally, coiled bodies of silver-stained filaments were encountered, mainly located within the white matter close to the cortical grey matter. Argyrophilic grains and coiled bodies contained dense accumulations of straight filaments with a diameter of about 9 nm. The argyrophilic grains were found in abundance within sector CA1 of the Ammon's horn and layer Pre-beta of the entorhinal region. A slightly less dense scattering of the grains occurred in layer IIIab of the adjoining temporal isocortex, insular cortex and orbitofrontal cortex. The basolateral amygdaloid complex and the hypothalamic lateral tuberal nucleus were the most affected subcortical structures. Deeper brain stem nuclei merely showed a sparse number of grains or were devoid of them. Eighty brains of demented individuals were examined. Forty-eight of them showed the features of Alzheimer's disease and four showed the features of Pick's disease. Twenty-eight cases revealed the abnormalities under consideration. Ten showed exclusively argyrophilic grains and coiled bodies, while 16 also had neuritic plaques, neurofibrillary tangles, and neuropil threads. One of the 28 cases was associated with Parkinson's disease and one showed features of both Parkinson's and Alzheimer's disease. Twenty brains of non-demented individuals of about the same age and devoid or almost devoid of Alzheimer changes were used as controls. None of the control brains showed the presence of argyrophilic grains and coiled bodies. These changes, therefore, are considered the morphological substrate of an unknown disease associated with adult onset dementia.

Cortical and subcortical argyrophilic grains characterize a disease associated with adult onset dementia

A method is described in which selective silver staining of Alzheimer's neurofibrillary changes is combined with staining of cell nuclei, Nissl material, and lipofuscin granules. Formalin fixed, paraffin embedded sections of human autopsy tissue are silver stained according to a method proposed by Gallyas. Lipofuscin is stained by crotonaldehyde fuchsin following performic acid oxidation. Nissl substance is visualized by either Darrow red or gallocyanin-chrome alum staining. Architectonic units showing the specific pathology and the neuronal types prone to develop the neurofibrillary changes can be recognized using this technique.

Silver Impregnation of Alzheimer's Neurofibrillary Changes Counterstained for Basophilic Material and Lipofuscin Pigment

Potassium concentration and number of neurons in cultures of dissociated ganglia

The new cresyl echt violet acetate, of which three different batches have been tested, proves to be a very useful Nissl stain. It is especially valuable for formalin-fixed, frozen-sectioned material. By using a buffered staining bath and controlled timing in dehydration it is possible, on paraffin embedded material, to use these dyes as progressive stains apparently specific for nucleic acids. With a saturated aqueous solution of the dye, especially when a mordant of lithium carbonate is used, it is possible to stain material that has been preserved in formalin for several years and also material from which nucleic acids have been removed. The dye is useful also for staining celloidin embedded material. With the buffered stain proposed, differentiation is much easier than with older methods which included a gross overstaining and a long destaining procedure.

An Evaluation of Cresyl Echt Violet Acetate as a Nissl Stain

A dye, which is probably a cationic chelate, has been separated from a gallocyanin-chrome alum staining solution and prepared in the dry form. This dye is apparently the major staining compound. To prepare the chelate or dye, dissolve 150 mg of gallocyanin and 15 gm of chrome alum in 100 ml of distilled water and boil for 10-20 min, cool, filter, wash the precipitate with sufficient distilled water to restore the volume of the filtrate to 100 ml, then add concentrated NH4OH until the pH is raised to 8-8.5. Filter, with suction, through a medium porosity fritted glass funnel. Wash with 100-200 ml of anhydrous ethyl ether and air dry the precipitate. This ratio of chrome alum to gallocyanin and the 10-20 min boiling time are optimal for preparation of the staining solution, which may be used either for staining or for separation of the chelate in its dry form. From the dried chelate, the staining solution is prepared as a 3% solution in1 N H2SO4 and a staining time of 16-24 hr is required. No differentiatio...

The gallocyanin-chrome alum stain; influence of methods of preparation on its activity and separation of active staining compound.

A new red basic dye, which has specificities similar to blue basic dyes and which exhibits metachromasia, has been named Darrow red, and is now commercially available. In a staining solution, prepared as indicated, it is stable for about 1 mo. Procedure: Dissolve 50 mg of Darrow red in 200 ml of 0.2 M acetic acid. Boil gently for 10 min; cool and filter. Stain frozen sections or decerated and hydrated mounted paraffin sections 20-30 min. Differentiate and dehydrate rapidly in 50, 70 and 95% ethyl alcohols followed by n-butyl alcohol, xylene and covering in synthetic resin.

Darrow red, a new basic dye.

Aldehyde blockage, methylation, acetylation, amine blockage, and 4 min, 30 min and 24 hr deamination of paraffin sections of cat spinal cord were followed by staining with Lendrum's phloxine-tartrazine, Luxol fast blue MBS, PAS, phosphotungstic acid-hematoxylin, and Weil stains. Only the effects on staining of myelin are reported. These histochemical procedures separated the 5 stains into 3 groups: (1) phloxine-tartrazine and Luxol fast blue, (2) PAS, and (3) Weil and phosphotungstic acid-hematoxylin. The 3 patterns indicate that these stains may attach to 3 different reactive molecular sites in the sections. For the Weil and phosphotungstic acid-hematoxylin, such reactive sites are probably a secondary or tertiary amine or both.

Iron Hematoxylin Chelates: II. Histochemistry of Myelin Sheath Stains

: A compound, which is probably a cationic chelate, can be isolated as a dry powder from a hematoxylinchrome alum lake. In aqueous acid solution this compound is an excellent nuclear stain which is extremely selective, very resistant to acids and alcohols, and self-limiting. Staining time may vary from 20 min to 16 hr without causing significant differences in staining intensity. To prepare the dry stain, dissolve 10 gm of hematoxylin, 10 gm of NaOH and 70 gm of chrome alum in 600 ml of distilled water, boil 20 min, cool and filter, allowing the filtrate to drop into 3.5 liters of absolute alcohol. Filter off the precipitate formed in the alcohol, and air dry it at room temperature. The staining solution is prepared by dissolving 3 gm of the dried precipitate in 100 ml of 3% HCl. (Author)

Margaret M. Powers

Papers

An Evaluation of Cresyl Echt Violet Acetate as a Nissl Stain

The gallocyanin-chrome alum stain; influence of methods of preparation on its activity and separation of active staining compound.

Darrow red, a new basic dye.

Iron Hematoxylin Chelates: II. Histochemistry of Myelin Sheath Stains

A self-limiting, highly selective chromiumhematoxylin stain,