Invasive colitis and hepatitis due to previously uncharacterized spirochetes in patients with advanced human immunodeficiency virus infection.

We describe three patients with advanced human immunodeficiency virus (HIV) infection, two with colitis and one with cholestatic hepatitis, for whom results of detailed endoscopic and histologic studies were suggestive of invasive spirochetosis. In the two patients with colitis, colonoscopic evaluation revealed either diffuse ulcerations or pustules; in both cases, there was histologic evidence of extensive superficial cell necrosis and infiltration of the mucosa and lamina propria with acute inflammatory cells. Spirochetes in the mucosa and crypts were visualized by Warthin-Starry silver staining. Morphologically similar spirochetes throughout the liver specimen from the patient with cholestatic hepatitis were demonstrated by Warthin-Starry silver staining. Analysis with electron microscopy revealed these organisms to be loosely coiled spirochetes. Despite extensive evaluation, no other pathogens were identified. Invasive spirochetal infection, as defined by the results of Warthin-Starry silver staining of involved tissues, should be considered in the differential diagnosis of patients with HIV infection who have otherwise unexplained colitis or cholestatic hepatitis.

Evaluation of new transport medium for detection of herpes simplex virus by culture and direct enzyme-linked immunosorbent assay.

The transport medium Multi-Microbe Media (M4) was evaluated prospectively by culture and direct enzyme-linked immunosorbent assay (ELISA) for detection of herpes simplex virus from 473 specimens. In addition, 377 specimens in Bartels Viral Transport Medium were evaluated. By using culture as a "gold standard," the ELISA sensitivity was approximately 85%, while the specificities exceeded 96% for both media.

Supplemental complement component C9 enhances the capacity of neonatal serum to kill multiple isolates of pathogenic Escherichia coli.

Previous studies demonstrated that, compared with adult serum, neonatal serum contained a diminished concentration of complement component C9 and that supplemental C9 enhanced the capacity of neonatal serum to kill an isolate of Escherichia coli. Therefore, experiments were designed to determine the mechanisms by which supplemental C9 enhances the bactericidal capacity of neonatal serum and to determine whether supplemental C9 enhances the capacity of neonatal serum to kill several different pathogenic strains of E. coli. A radiobinding assay and immunogold electron microscopy using a monoclonal anti-C9 antibody revealed that, compared with 40% adult serum, neonatal serum deposited a diminished quantity of C9 onto E. coli O7w:K1:NM. Supplemental C9 (75 mg/L) significantly enhanced the quantity of C9 deposited by the neonatal serum. Treatment with 10 mM MgEGTA (a mixture of 100 mM MgCl2 and 100 mM EGTA that blocks activation of the classic complement pathway but leaves the alternative pathway intact) abolished the capacity of neonatal serum to deposit C9 and to kill the bacteria. Supplemental C9 enhanced the capacity of neonatal serum to kill eight different blood isolates of E. coli. Therefore, supplemental C9 enhanced the capacity of neonatal serum to kill E. coli by increasing the total quantity of C9 deposited via activation of the classic complement pathway. Neonatal serum contained sufficient quantities of classic pathway components, other than C9, to deposit the supplemental C9 onto E. coli and to enhance bacterial killing. The bactericidal activity of neonatal serum against multiple isolates of pathogenic E. coli was increased after C9 supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of actin in developing outer hair cells in the gerbil.

During the two weeks following the onset of cochlear function in the gerbil, active cochlear processes appear to mature. The active cochlear processes likely involve outer hair cells with their specialized lateral wall structures, including the subsurface cisternae and associated cytoskeletal elements. We have previously demonstrated that the subsurface cisternae mature gradually during the time that active cochlear processes mature in the gerbil. In the study reported here, we used postembedding immunocytochemical electron microscopy to investigate whether actin labelling associated with the cortical cytoskeleton of the gerbil outer hair cell increased concomitantly. In contrast to the gradual development of the subsurface cisternae, actin labelling in the region of the cortical cytoskeleton significantly increased during the onset of cochlear function and maintained this level during the time that active cochlear processes mature. Thus, it appears that increased actin adjacent to the lateral plasma membrane of the outer hair cell is related to the onset of cochlear function rather than to the maturation of active cochlear processes.

Actin distribution along the lateral wall of gerbil outer hair cells.

Outer hair cells can contract parallel to their long axis, and it has been hypothesized that actin may play a role in this contraction. In this study, actin distribution was examined in the gerbil organ of Corti using postembedment immunoelectron microscopy. In addition to regions typically labelled by actin antibodies and observed by epifluorescence--the cuticular plate, stereocilia, and supporting cell processes--these procedures preserved the ultrastructure of the cell and allowed us to demonstrate actin reactivity along the lateral wall of the outer hair cells between the subsurface cisterns and the plasma membrane. This region is the location of structures (pillars and cortical cytoskeleton) though to be associated with contraction of the outer hair cells.

Origin and colocalization of CGRP- and SP-reactive nerves in cat airway epithelium.

A combination of neuroanatomic techniques was used to examine the origin and neuropeptide content of nerve fibers in the airway epithelium of adult cats. By the use of immunocytochemical methods, the peptides substance P (SP) and calcitonin gene-related peptide (CGRP) were colocalized in airway epithelial nerve fibers. Two days after wheat germ agglutinin (WGA) was injected into the nodose ganglion, fibers containing WGA immunoreactivity (IR) were detected in the airway epithelium. SP-like immunoreactivity (LI) and CGRP-LI were demonstrated separately in the WGA-IR fibers, establishing their origin from nerve cell bodies of nodose ganglion. Vagal transection inferior to the nodose ganglion reduced the number of SP- and CGRP-IR fibers by greater than 90% in ipsilateral airways. In contralateral airways, SP-IR fibers were substantially reduced, whereas the effect on CGRP-IR fibers was not statistically significant. Vagotomy superior to the nodose ganglion did not alter the density of peptide-IR fibers. The results prove that SP- and CGRP-IR nerve fibers of cat airway epithelium originate from nerve cell bodies in the nodose ganglion and that SP- and CGRP-like peptides may be stored together in some nerve fibers of the airway epithelium.

Co-localization of vasoactive intestinal peptide- and substance P-containing nerves in cat bronchi.

The occurrence of vasoactive intestinal peptide (VIP) and substance P in nerve fibers within the lung is well established, and both VIP- and substance P-containing nerve fibers are known to supply pulmonary vascular and bronchial smooth muscle and submucosal glands. In the present study, we have investigated the co-localization of these two peptides in cat lung. The co-localization procedure follows a standard immunocytochemical protocol except that the primary and labeled secondary antisera each contain a combination of two antisera allowing the simultaneous detection of two antigens in a single tissue section. Using fluorescence microscopy, VIP- and substance P-containing nerve fibers were co-localized in bronchial smooth muscle, in the walls of pulmonary and bronchial arteries, and around submucosal glands. VIP and substance P were also co-localized in nerve cell bodies that comprised the intrinsic airway ganglia. Substance P-containing nerve fibers were observed within the bronchial epithelium, but VIP was not present at this location. The co-localization of VIP and substance P in the same nerve fibers suggests that airway and pulmonary vascular function may be partially regulated by the simultaneous or sequential release of VIP and substance P from the same nerve fibers. The results also suggest that, in addition to extrinsic nerve fibers that contain substance P, the airways of cats are supplied by substance P-containing nerve fibers that originate from intrinsic nerve cell bodies.

Ultrastructural colocalization of the bioactive mediators 5-hydroxytryptamine and bombesin in endocrine cells of human fetal airways.

Endocrine cells in the airway epithelium of human fetal lungs are known to contain an amine, 5-hydroxytryptamine (5HT), and a peptide, bombesin (BOM). These mediators may be involved in regulating smooth muscle and secretory activity in the airways as well as in development of the fetal lung. However, the exact endocrine cell type that contains 5HT and BOM has not been described at the ultrastructural level. This investigation provides immunocytochemical evidence that 5HT and BOM are stored in a single cell type, the P1 cell. Thin sections of airways from human fetal lungs were incubated either in anti-5HT antiserum (diluted 1:3000) or in anti-BOM antiserum (diluted 1:600) and then labeled with affinity purified goat anti-rabbit IgG coupled to 16 nm gold particles. For colocalization, thin sections were incubated on one side to demonstrate 5HT and on the other side to demonstrate BOM. Two different sizes of gold particles (10 and 30 nm) were coupled to IgGs and used for the labeled second antibodies. Controls consisted of absorbing of the primary antiserum with an excess of either 5HT or BOM. 5HT- and BOM -like immunoreactivities were observed in the dense-core vesicles (DCV) of P1 cells, and it was apparent from serial sections that 5HT and BOM labeling was sometimes present in the same P1 cells. Sections labeled for 5HT on one side with large gold particles and for BOM on the other side with small gold particles revealed that 5HT- and BOM-like immunoreactivities were located in the same DCV.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructural immunocytochemical localization of 5-hydroxytryptamine in gastric enterochromaffin cells.

Enterochromaffin (EC) cells in the gastrointestinal tract are known to contain 5-hydroxytryptamine (5HT). The probable ultrastructural localization of 5HT in the dense core vesicles ( DCVs ) of EC cells is based on the use of histochemical techniques, such as argentaffinity and the potassium dichromate reaction. In the present paper we describe an immunocytochemical method for specifically localizing 5HT in EC cells by electron microscopy. Pieces of mucosa from the pyloric region of the rabbit stomach were prepared for electron microscopy by fixation in 0.5% glutaraldehyde-picric acid-formaldehyde without osmication , and then embedded in LX-112. Thick sections (1 micron) were mounted on glass slides and processed for the fluorescence immunocytochemical localization of 5HT. Thin sections (60-90 nm) were mounted on formvar-coated slot grids and processed for the ultrastructural immunocytochemical localization of 5HT. Both the thick and thin sections were processed by an identical procedure, beginning with a 30-min incubation in anti-5HT antiserum diluted 1:1400, followed by an IgG-FITC-gold-labeled second antibody. Fluorescent EC cells were consistently observed in the thick sections of gastric mucosa. By carefully trimming and sectioning the adjacent block face, the identical EC cell could be identified by electron microscopy. A quantitative analysis revealed the number of gold particles in EC cells to be significantly greater over the cores of DCVs than over the non-core cytoplasm or over the nucleus. Absorption of the primary antiserum with 5HT abolished all labeling, while absorption with a 5HT precursor, 5-hydroxytryptophan, did not significantly reduce core labeling. Non-EC epithelial cells were not labeled. These results demonstrate that immunoreactive 5HT in EC cells is stored in the cores of DCVs .

Fibronectin and cell shape in vivo: studies on the endometrium during pregnancy.

The rat endometrium during pregnancy was used as a model system to study fibronectin in vivo. Fibronectin distribution on stromal fibroblasts, as determined by indirect immunofluorescence staining, was studied in relationship to cell shape during decidual transformation. Fibroblasts of the estrus endometrial stroma were elongated cells with a fibrillar pattern of fibronectin on their surfaces. During days 1-6 of pregnancy, as these elongated cells acquired a round morphology, fibronectin changed first to a patched distribution on the cells'a surfaces and then disappeared. The change in fibronectin was specific for the fibroblasts since over the same time period there was no decrease in fibronectin found associated with blood vessels or in the epithelial-stromal basement membrane. These results support the proposed relationship between cell surface fibronectin and cell shape that has been inferred from in vitro experiments. After implantation, fibronectin distribution was studied in relationship to the position of the conceptus. In the stroma proximal to the implanting conceptus, fibronectin was absent except around blood vessels, which may help explain how decidual tissue could act as a barrier to trophoblast invasion. Finally, fibronectin distribution was studied in the uterus after parturition. Debris in the uterine lumen was coated with fibronectin, which may be important in the rapid removal of this material by phagocytic cells. Also, fibronectin associated with the epithelial-stromal basement membrane was reorganized after reepithelialization had occurred.