Immunohistochemical evidence of the extracellular localization of calcium-activated neutral protease (CANP) in rabbit skeletal muscle, lung and aorta

The subcellular localization of calcium-activated neutral protease requiring a millimolar calcium concentration (m-CANP) was examined by light and electron microscopy in various tissues of the rabbit, using an immunoperoxidase method with a monoclonal antibody (1C6D1). In skeletal muscles, specific staining for m-CANP was recognized on collagen fibrils (ca 40 nm in diameter) with a periodic banding pattern. In the lung, dense reaction products were precipitated on elastic fibers under the bronchial epithelia. In the aorta, tunica intima and adventitia were intensely stained. Dense reaction products were observed on collagen fibrils and elastic fibers. Basal laminae, on the other hand, were not stained by anti m-CANP antibody in these tissues. These findings suggest that m-CANP may be involved in the regulation of the structure and function of the extracellular matrix.

Optic nerve regeneration by peripheral nerve transplant

We studied the morphology of regenerated retinal ganglion cells and their axons in adult rodents after axotomy and autologous transplantation of the sciatic nerve. Regenerated ganglion cells, backlabeled with rhodamine dextran, were of similar size to or larger than those of intact cells in control animals. Dendrites and occasionally axons as well showed abnormal morphologies in most cells, though some cells appeared quite normal. Cross-sections of the regenerated axons, observed by electron microscopy, were always attached to either the Schwann cell cytoplasm or the basal lamina. The immunoreactive structures to anti-laminin antibody were quite irregular in the cross-sectioned graft and, compared with those of the intact sciatic nerve, they were generally smaller. Their appearance closely resembled that of the basal lamina in the graft observed by electron microscopy. These observations, taken together, suggest that the laminin-rich basal laminae of Schwann cells are essentially important for the regeneration of retinal axons in adult rodents.

The effect of fixatives and paraffin embedding on the histochemical reactivity of a monoclonal antibody against human type IV collagen (JK-199)

A new monoclonal antibody (JK-199) was found to react with basement membranes on paraffin-embedded tissue sections without prior enzyme digestion. JK-199 was shown to react with isolated type IV collagen treated by any of four different fixatives--PLP, 4% formalin, modified Zamboni's (0.2% picric acid, 4% paraformaldehyde in 0.1 M phosphate buffer, pH 7.4) or Bouin's--applied for 6 h at room temperature and incubated at 60 degrees C for 30 min to simulate routine tissue processing. None of the fixatives was able to alter the reactivity of JK-199 with isolated type IV collagen. In the human placenta, specific and intense staining of basement membranes was demonstrated on paraffin sections fixed with any of the four fixatives. In human skin, basement membranes were fully demonstrated on paraffin sections fixed by PLP fixative or by 4% formalin, but only partially on sections fixed by picric acid-containing fixatives. Optimal results, i.e., with the least non-specific or incomplete staining, were obtained on PLP-fixed paraffin-embedded tissues. In PLP-fixed paraffin sections of the kidney, skeletal muscle, and small intestine, all basement membranes were stained intensely by this antibody (JK-199) at the expected locations. The results indicate that JK-199 may be widely applicable for the analysis of basement membrane kinetics, including developmental processes or pathological conditions.

Lack of muscularis mucosa and the occurrence of Boerhaave's syndrome

Six patients with spontaneous rupture of the esophagus (Boerhaave's syndrome) were surgically treated in the Department of Surgery II, Kyushu University. Two patients underwent esophageal resection. Histopathologic examinations revealed the absence of muscularis mucosa around the sites of esophageal rupture in these two patients. In the patient treated most recently, serial histologic investigation demonstrated that the lack of muscularis mucosa existed not only around but also along the longitudinal extension of the site of rupture. This finding suggests that lack of muscularis mucosa in the esophageal wall may be one cause of spontaneous rupture of the esophagus.

Immunoelectron microscopical evidence that type V collagen is a fibrillar collagen: importance for an aggregating capability of the preparation for reconstituting banding fibrils

Type V collagen has already been shown, in many immunohistochemical studies, to be widely distributed in connective tissues. Its supramolecular structure, however, has been unclear. We demonstrate that the major aggregates formed from type V collagen solution in vitro are fine fibrils with a D-periodic banding pattern. Further, by using the immunogold labeling method, we find that these fibrils react strongly with anti-type V collagen antibody. Electronmicroscopic examination showed three kinds of aggregate: fine fibrils with periodic banding pattern, fine fibrils without banding pattern, and non-fibrillar materials. Both striated and nonstriated fibrils, when incubated with rat polyclonal anti-human type V collagen IgG followed by incubation with 15 nm-gold conjugated goat anti-rat IgG, were labeled with colloidal gold. We conclude that type V can be classified as a fibrillar collagen. Also, from the present findings together with previous studies, we believe type V collagen may exist in vivo in various connective tissues as fine fibrils with a 67 nm-periodic banding pattern, by itself, or with type I or type III fibrillar collagen, being located between, and connecting the basal lamina and interstitial collagen fibers.

Growth rate of human fibroblasts is repressed by the culture within reconstituted collagen matrix but not by the culture on the matrix

Effect of reconstituted type I collagen gel on in vitro growth of fibroblasts was examined. A prolonged lag period was observed by culture either on the surface of three-dimensional collagen gel ("on-gel") or within the gels ("in-gel") as compared with the culture on plastic dishes. The rate of cell proliferation in logarithmic phase growth was repressed by the culture "in-gel" but not by the culture "on-gel". The differential growth rates between "in-gel" culture and "on-gel" culture should be ascribed to difference in distributions of interacting sites between cell and collagen fibrils. The repression of cell growth was more marked in a contracting collagen gel which contains higher density of collagen fibrils. The cell density in contracted gel per unit cross-section area was found to be much lower than that of confluent monolayer culture. These results suggest that the repression of cell growth by collagen fibrils in the three-dimensional gels is not due to direct cell-cell contact, but due to the distribution and number of contact sites between a cell and collagen fibrils.

Characterization of a monoclonal antibody against human placenta type IV collagen by immunoelectroblotting, antibody-coupled affinity chromatography, and immunohistochemical localization

We have produced four monoclonal antibodies against type IV collagen obtained from human placenta. An antibody with a high titer by ELISA, named JK-199, reacted not only with type IV collagen in the triple-helical conformation but also with thermally denatured chains. After affinity chromatography on JK-199 antibody-coupled resin, the amino acid composition and CD spectrum of the affinity-purified peptides from the crude pepsin extract of human placenta were typical of those of human type IV collagen in the triple-helical conformation. On SDS-polyacrylamide gel electrophoresis, the purified protein showed only one broad band with a molecular weight of approximately 260,000 before reduction and six smaller peptide bands after reduction. On immunoelectroblotting, JK-199 reacted with all six peptide bands. Immunohistochemically, typical basement membranes were exclusively and strongly stained with JK-199 on frozen sections of PLP-fixed human placentas without any enzymatic pretreatment in the routine immunoperoxidase method. Judging from these findings, it is concluded that the epitopes of type IV collagen that reacted with JK-199 are exposed on the surface of basement membranes. This antibody should be useful for identification of type IV collagen in normal or pathological basement membranes or other structures.

Comparison of axial banding patterns in fibrils of type V collagen and type I collagen

Type V collagen and type I collagen were obtained from human placenta, essentially by salt fractionation. Precipitates were formed from mixed solutions of type V collagen and type I collagen in various ratios. They were incubated at 37 degrees C for 1 hour and negatively stained with 0.5% uranyl acetate (pH 4.4) at 37 degrees C. The specimens, seen by electron microscopy, were fibrils with a D-periodic banding pattern. Axial electron density profiles of collagen fibrils were obtained from selected electron micrographs by densitometric tracing. The slit width corresponded to 1.5 nm. The relative electron densities of overlap region vs. hole region were lower than 20% in fine fibrils containing a significant amount of type V collagen. It is suggested that the overlap region of such collagen fibrils may be loosely packed, being accessible to uranyl acetate, or the hole region may be filled by larger non-collagenous portions of type V collagen, resulting in loss of the light and dark alternation. Six to 8 white transverse lines were discerned per period and labeled consecutively with Arabic numerals. White lines 2 and 5 tended to merge with lines 1 and 4, respectively, in collagen fibrils formed from a solution containing a significant amount of type I collagen or pure type I collagen. The eight white lines corresponded to c2, c1, b2, b1, a4, a1, e1 and d with reference to their locations in the D-period. The locations of white lines in collagen fibrils which contain significant amount of type V collagen were identical with those in type I collagen fibrils. This is consistent with the primary structure that the axial distribution of charged amino acids in type V collagen is quite similar to that in type I collagen.

Type V collagen in splenic reticular fibers of the macaque monkey

The distribution of type I, III and V collagens in the monkey spleen was examined by indirect immunofluorescent microscopy and immunoelectron microscopy, and compared with that of reticular fibers revealed by a silver impregnation method. Type I collagen was localized on reticular fibers in the white pulps and on coarse reticular fibers in the splenic cords. Type III collagen was localized on the reticular fibers in the white pulps, and on the coarse reticular fibers and a limited number of fine reticular fibers, in the splenic cords. The anti-type V collagen antibody reacted with annular reticular fibers around the splenic sinuses, as well as with the reticular fibers in the white pulps and with the coarse and fine reticular fibers in the splenic cords. Thus, the distribution pattern of fibers that reacted with the anti-type V collagen antibody was very similar to that of the reticular fibers revealed by the silver impregnation method. Electron-microscopically, the fine reticular fibers in the splenic cords were composed of collagen fibrils, 30-50 nm in diameter, and amorphous substances. They were covered by reticular cell processes. By immunoperoxidase labeling with the anti-type V collagen antibody, electron-dense reaction products were found over the collagen fibrils with a banding pattern. These results indicate that type V collagen is an indispensable component of the reticular fibers.

Clinical application of the pattern electroretinogram with lid skin electrode

Pattern evoked potentials were recorded simultaneously with an electrode placed on the skin of the lower eyelid, gold foil electrodes hooked on the right and left eyelids, and a skin electrode at Oz in normal subjects and in patients with optic nerve and macular diseases. Peak latencies and amplitudes of the pattern electroretinogram (PERG) were compared between the two electrodes. In both records, the peak latency showed no difference at 56.7 +/- 2.9 ms (mean +/- S.D.), while the amplitude of the PERG with the lid skin electrode was at 1.2 +/- 0.3 microV, approximately one-third of that obtained with the gold foil electrode. Although the skin electrode did not always record responses as well as the gold foil, its advantages recommend its use in clinical cases.

Improved Kupffer's gold chloride method for demonstrating the stellate cells storing retinol (vitamin A) in the liver and extrahepatic organs of vertebrates

This paper describes our modification of the classical gold chloride technique for the demonstration of the perisinusoidal stellate cells in the liver. The results of the method as introduced by von Kupffer (1876) are unpredictable. Using our modification, high quality gold preparations can be obtained. The method allows selective staining of retinol (vitamin A)-storing stellate cells in the liver and extrahepatic organs of various vertebrates. The sensitivity of the reaction is comparable to that of the fluorescence method for retinol. The technique is simple and the preparations keep for several years. Formol fixed specimens can be counterstained with Sudan III or hematoxylin. We have also developed a simple technique for making "sinusoid-net preparations," removing the parenchymal cells by supersonication. The clear visualization of the stellate cells that results has made it possible to study the distribution of these cells.

Follow-up studies in pattern VECP in demyelinating diseases in children

Demyelinating disease in children is known to be relatively rare. We report three cases defined as Devic's disease, acute disseminated encephalomyelitis, and multiple sclerosis. Follow-up studies of pattern appearance-disappearance visual evoked cortical potentials (VECPs) and pattern reversal steady state VECPs were performed. Results showed delays of appearance-disappearance VECPs that improved to shorter latencies with the improvement of visual acuity; however, recovery of VECPs was found to be behind the recovery of subjective vision. On the other hand, steady-state VECPs showed no normal waveforms even when vision recovered. Recovery of steady-state VECPs was found to be far behind that of transient VECPs and vision.

Pattern disappearance visually evoked cortical potential in the diseases of visual pathway

Visually evoked cortical potentials in response to pattern-appearance, -disappearance, and -reversal stimuli were studied in normal subjects and in patients suffering from optic neuritis. It was found in normal subjects that pattern disappearance VECPs were as reliable as the pattern reversal ones. On the other hand, the appearance response showed interindividual differences which made its evaluation rather difficult. The same was true in the records of the patients. Both the mean peak latencies of the disappearance responses and those of the pattern reversal ones were prolonged significantly in optic neuritis, compared with those obtained from normal subjects. We concluded that the peak latencies of the disappearance response could be more confidently used than those of the appearance response for diagnosing optic neuritis.

In vitro formation of hybrid fibrils of type V collagen and type I collagen. Limited growth of type I collagen into thick fibrils by type V collagen

Type V collagen and type I collagen were obtained from human placentas by pepsin treatment, followed by salt fractionation. The precipitates formed at 37 degrees C from a mixed solution of type V collagen and type I collagen, reacted with antibodies to either type V collagen or type I collagen. The precipitates seen by electron microscopy were fine flexible fibrils, with a D-periodic banding pattern. The average diameter of hybrid fibrils was smaller than 50 nm, when the proportion of type V collagen exceeded that of type I collagen. Type V collagen directly interacts with type I collagen in forming hybrid fibrils, resulting in limitation of the growth of type I collagen fibrils into thicker fibrils. We propose that the fibrils with a predominant type V collagen content may occur in the pericellular environment of various tissues, as a basic structure in connecting basal laminae with interstitial collagen fibrils.

In vitro formation of fine fibrils with a D-periodic banding pattern from type V collagen

Type V collagen was isolated from human placenta by limited pepsin treatment and purified by salt fractionation. A solution of type V collagen was dialyzed at 4 degrees C against phosphate-buffered saline or against 0.02 M Na2HPO4. Aggregates formed under these in vitro conditions from a pure type V collagen solution were examined by electron microscopy. The aggregates were fine flexible fibrils. The fibrils formed during incubation at 25 degrees C were of relatively uniform diameter, 34.8 +/- 9.1 nm and did not show an axial banding pattern. When the specimen was incubated at 37 degrees C, the fibrils were of slightly larger diameter, 38.2 +/- 9.1 nm and almost all the fibrils had the axial repeat pattern of 67 nm. The ability of type V collagen to form banding fibrils is discussed in relation in the localization of the collagen in tissues.

Fluctuation in the development of various skeletal muscles in the chick embryo, with special reference to AChE activity and the formation of neuromuscular junctions

Acetylcholinesterase (AChE)-rich cytoplasmic granules in the developing myofibers increased remarkably until the establishment of neuromuscular junctions and thereafter decreased rapidly, whereas junctional AChE activities continued to increase (K. Wake, 1976, Cell Tissue Res. 173, 383-400). In the present paper, during the developmental course of the chick embryo, the temporal and regional gradients in differentiation of skeletal muscles at various sites were examined with special reference to the fluctuation of intracellular AChE activity. AChE-rich granules in each muscle throughout the whole body of chick embryos were observed. Since the distribution pattern of these granules changed regularly in the course of the muscle fiber development, advances of muscle differentiation in various sites of the body were compared. (1) The process of muscle development is more advanced in the trunk muscles than in the limb muscles. (2) The dorsal trunk muscles differentiate one day earlier than the ventral ones. (3) Within the same limb, proximal muscles differentiate approximately 24 hr ahead of distal ones. (4) The development of posterior limb muscles advances faster than that of anterior limb muscles. (5) Within the thigh muscles, the flexor muscles tend to differentiate earlier than the extensor muscles.