Leishmania major: in vitro ultrastructural study of the paraxial rod of promastigotes.

The flagellum of Leishmania major promastigotes has an intraflagellar structure known as the paraxial rod (PAR) which extends from a point halfway in the flagellar pocket to the tip of the flagellum, lying opposite the axonemal microtubule doublets 4-7. An expansion of the axonemal plasma membrane envelops the PAR and may provide desmosomal attachment at the orifice of the flagellar pocket. The complex organization of the 4-6 nm thick filaments in the PAR was studied by us in cross, oblique, longitudinal and tangential sections by electron microscope.

Ultrastructural study of a corneal keloid.

A 69-year-old man developed keloid overgrowth on his left cornea in response to an injury from a fingernail. The lesion was removed by superficial lamellar keratectomy and was studied by electron microscopy, and light microscopy after immunoperoxidase staining for actin. The surgical specimen revealed disorganised, anteriorly atrophied and posteriorly vascularised connective tissue stroma.

Conjunctival ophthalmomyiasis caused by the sheep nasal botfly (Oestrus ovis).

Three patients had conjunctival ophthalmomyiasis caused by the ovine nasal botfly. All patients had a sudden onset of redness, tearing, and foreign-body sensation of the affected eye. One to nine Oestrus ovis first-instar larvae were removed from the bulbar or palpebral conjunctiva of each patient.

Sexual dimorphism on the immune responses of the snake, Psammophis sibilans.

Recent trends in research have documented the influence of sex factors on the immune response of higher vertebrates. The present study is the first to indicate the existence of sex-dependent differences in the immune potentiality in reptiles. In optimal seasonal conditions, kinetics of the primary anti-rat erythrocytes (RRBC) antibody response were compared in individual male and female snakes, Psammophis sibilans.

Orbital myiasis.

Invasion of the orbit by dipterous fly larvae is a rarely reported from of myiasis. We present a 65-year-old man with orbital myiasis caused by the tissue obligatory larvae of the Old World screw-worm fly Chrysomyia bezziana Villeneuve. Larvae were found invading the orbital apex and exenteration was carried out to prevent intracranial invasion.

Ultrastructural studies on sporogony of Babesia microti in salivary gland cells of the tick Ixodes dammini.

Tick larvae were permitted to feed on infected hamsters and then allowed to molt. Nymphs were examined just prior to feeding on uninfected hamsters or at timed intervals thereafter. Invasion of the salivary gland by B.

A device for serially mounting 0.5-2.0 micrometer sections of 1-2 millimeter epon embedded tissue blocks for light microscopy.

The construction and operation of a simple device for serially mounting small Epon sections for light microscopy are described. This device allows the middle portion of the slide to serve both as a shallow reservoir behind the knife edge for flotation of serially oriented sections, and as a miniature hot plate for the subsequent flattening and adhesion of the sections. The advantages of this device, which gave consistently good results with Epon embedded Argas (Persicargas) arboreus tick tissues, are discussed.