One of the problems in the study of mammary carcinomas is the cellular heterogeneity which they present. The use of a specific histochemical marker can help to distinguish the two principal cellular types found in the mammary gland; the epithelial and myoepithelial cells.

Mammary glands of female Balb/C mice of different ages were removed and fixed in 1.5% glutaraldehyde in 0.1M cacodylate buffer pH 7.2 with 1% sucrose. After two hours of fixation at 4°C, the material was washed in 0.1M cacodylate buffer, sectioned with a Smith-Farquar microtome set at 70-100u, and incubated for the histochemical detection of ATPases. The tissue was then washed again with 0.1M cacodylate buffer, postfixed in 1% osmium tetroxide, dehydrated, and embedded in an Epon-Araldite mixture.

For the Mg++ dependent ATPase the conventional method of Wachstein and Meisel was followed. The Mg++ dependent ATPase is localized in the plasma membranes of the epithelial and myoepithelial cells (Fig. 1).

Several techniques have been developed for the quantitative microchemical analysis of thin foils. These procedures require that in an alloy AB the measured intensity ratio, IA/IB frora the foil be independent of foil thickness. Cliff and Lorimer find that this condition is met in all cases they have examined whereas Jacobs and Baborovska show data where absorption of longer wavelength X-rays was apparent.

The present study was undertaken to evaluate these procedures for the combination of a scanning transmission electron microscope (JEOL JSEM 200) and an energy dispersive analyzer (Ortec).

Several types of mammalian sensory receptor cells possess modified cilia which may play a primary role in stimulus detection. Axonemes and basal apparatus from other types of cilia and flagella have been isolated, characterized and compared in detail. In this communication we report results of what may be the first attempt to isolate and characterize such structures from a sensory cilium, the bovine retinal rod outer segment.

Bovine eyes were obtained from a nearby abattoir, the retinas were removed and swirled vigorously in a cold solution of 50% sucrose, 5 mM Tris, 2 mM MgCl2, pH 7.5, to detach outer segments. The suspension was then filtered through cheesecloth and the filtrate was centrifuged at 20,000 rpm for 1 hr. Rod outer segments were collected from the solution surface, diluted, layered onto a continuous sucrose gradient (25-38% sucrose in Tris MgCl2 buffer) and centrifuged for 3-12 hrs. at 10,000 rpm.

Recently, the late R. Shiromizu carried out studies to establish the limits of metastability in the Cu-Be system. Con-currently, we engaged in parallel research, but with a broader emphasis on the microstructures concomitant with quenching, aging and reversion. A complete report covering 0.16 to 2.1 wt.% Be will be published elsewhere; certain unique structures are presented below.

Alloys of >0.8 wt.% Be quenched from the α (f.c.c.) region exhibit weak {110} tweed strain contrast. Direct lattice imaging did not detect discrete particles in this condition, whereas rather high densities of {100} G.P. Zone plates in regular stairstep array were revealed after aging at temperatures well below the G.P.Z. solvus.

This paper discusses the latest developments and results obtained from a field emission scanning transmission microscope. Some features of the instrument have already been described. The microscope has been in routine operation for more than two years at accelerating voltages of 80 and 100kV. Over this period a number of (111) and (310) oriented tungsten tips have been fitted and operated for varying periods in order to access the minimum lifetime to be expected. No tip has yet failed in service, and the (111) tip in current use has given more than 500 hours of stable and trouble free operation, in a vacuum of 3 to 5 x 10-11 torr.

Many of the TEM studies of radiation damage in crystalline materials have been directed toward illucidating the nature, number density, and size distributions of the primary structural defects resulting from the displacement of atoms from their normal lattice sites, i.e., "black spots." The "black spots" have been identified as either nonresolvable dislocation loops or planar clusters of self interstitials or vacancies by TEM techniques and diffraction contrast theories that are described in the book by Hirsch, et al. and the reviews by Ruhle and Eyre. An indispensable part of the studies of point defect clusters is the identification of their character (vacancy or interstitial).

If aluminum is anodized in a bath, such as sulfuric acid, in which the anodic oxide coating has appreciable solubility, then the oxide layer may grow to a thickness of many microns. The resulting film can be regarded as consisting of two layers, a thin barrier layer adjoining the surface of. the metal, and an outer thick film containing pores. The latter convey the electrolyte to the barrier layer, permitting continued oxidation.

We have examined the structure of a number of sulfuric acid anodized films to assess the applicability of the two principal models of the pore structure. The older model represented the pores as rather regularly spaced, uniform channels running nearly normal to the oxide surface, separated by walls of amorphous alumina. Although conceived as starshaped rather than circular in cross-section, experimental evidence has pointed to the latter. In this ideal model, the porous film was made up of hexagonal cells of amorphous alumina, each containing a central pore.

The illumination system of the conventional transmission electron microscope is designed to provide an adequate level of coherent illumination over the field of view being examined. The additional requirement of providing the maximum possible current into very small (sub-micron) focussed spots, as is required by X-ray microanalysis for example, necessitates a probe forming lens with a very short working distance and has previously been met by using either a mini-lens or the prefield of the objective lens when used in the Single-Field Condenser-Objective mode.

The SFCO gives the smallest spot size and aberration parameters but suffers from the disadvantage that the illumination and imaging fields are not independently controllable.

Our studies of mammary tumor virus have included the application of the unlabeled antibody enzyme method of Sternberger to mammary tumor derived mouse cells in culture and observation with an electron microscope. The method avoids the extravagance of covalent binding of indicator molecules (horseradish peroxidase) with precious antibody locator molecules by relying instead upon specific antibody-antigen linkages. Our reagents included: Primary Antibody, rabbit anti-murine mammary tumor virus (MuMTV) which was antiserum 113 AV-2; Secondary Antibody, goat anti-rabbit IgG gamma chain (Cappel Laboratories); andthe Indicator, rabbit anti-horseradish peroxidase - horseradish peroxidase complex (PAP) (Cappel Labs.). Dilutions and washes were made in 0.05 M Tris 0.15 M saline buffered to pH 7.4. Cell monolayers, after light fixation in glutaraldehyde, were incubated in place by a protocol adapted from Sternberger and Graham and Karnovsky, then embedded by our usual method for monolayers. Reagents were confined to specific areas by neoprene 0-rings (Parker Seal Co.) reducing the amount of reagent needed to 50 microliters, 1/6th of that required to wet a 35 mm petri dish.

Small amounts of nickel are added to titanium to improve the crevice corrosion resistance but this results in an alloy which has sheet fabrication difficulties and is subject to the formation of large Ti2Ni precipitates. These large precipitates can serve as local corrosion sites; but in a smaller more widely dispersed form, they can have a beneficial effect on crevice corrosion resistance. The purpose of the present work is to show that the addition of a small amount of Mo to the Ti-1.5Ni alloy reduces the Ti2Ni precipitate size and produces a more elongated grained microstructure. It has recently been reported that small additions of Mo to Ti-0.8 to lw/o Ni alloys produce good crevice corrosion resistance and improved fabrication properties.

Pseudofolliculitis barbae (PF) is a dermatological disorder affecting approximately 50%. of black men who shave. The disease is characterized by ingrown hairs and attendant papules, pustules or vesicles ("razor bumps") which can occur over the entire beard area but which are most prevalent in the submandibular region. While it is generally accepted that the disease is of biological origin, PF appears to be triggered by shaving which in turn leads to the immediate cause of the disorder, ingrown hair formation. However, differences of opinion exist as to the basic etiology of PF--that is, how ingrown hair formation occurs in certain individuals and not others. Therefore a comparison of the skin, hair and post-shave beard hair regrowth patterns of "normal" and PF-prone black and white men by scanning electron microscopic (SEM) examination of polyethylene replicas was undertaken to determine the causes of ingrown hair formation.