Morphology of capillary-like structures in a three-dimensional aorta/collagen gel culture

The morphology of capillary-like tubes was investigated by electron microscopy (TEM and SEM) using an in vitro model of capillarogenesis (aorta/collagen type I gel). This model allowed morphological comparisons with in vivo capillaries and an evaluation of the functional maturity of the endothelium to be made. The lumina developing in vitro were demarcated by endothelial cells of varying thickness (0.1-2 microns). Pericytes were resting on the outside. The endothelial cells were characterized by contacts of varying length with tight and gap junctions and occasional indentations. The inner surface exhibited areas both with pronounced and without any endocytotic activity. In addition to a large Golgi apparatus, a varying number of cell organelles occurred depending on the thickness of the endothelium. Bundles consisting of microfilaments were often located underneath the outer cell membrane and in the vicinity of contact areas. A lamina densa was in the process of formation. The capillaries grown in vitro closely resembled those in vivo and showed a high degree of differentiation. Hence, this in vitro model allows the study of a number of functions of endothelial cells.

Formation of new capillary-like tubes in a three-dimensional in vitro model (aorta/collagen gel)

Direct sprouting (angiogenesis) does not occur during the formation of capillary-like tubes in an aorta/ collagen gel in the in vitro model. However, emigration of cells which stretch, arrange themselves side by side, form contacts (unspecific, tight and gap junctions), develop a lumen and show differentiation of endothelial cells (including the formation of a lamina densa and the appearance of pericytes) have been observed, i.e. vasculogenesis occurs. The origin of long, stretched cells is not known with certainty. They possibly represent smooth muscle cells. In addition, other cell types have been found, such as fibrocyte-like and fibroblast-like cells, elastoblasts, fat cells, monocytes and macrophages. All these cells are able to produce factors that promote the formation of new capillaries. Hence, a knowledge of these cells appears to be important for the analysis of in vitro systems. Moreover, the occurrence of these cell types must be considered when assessing possible effects.

Identification of protein transport complexes in the chloroplastic envelope membranes via chemical cross-linking

Transport of cytoplasmically synthesized proteins into chloroplasts uses an import machinery present in the envelope membranes. To identify the components of this machinery and to begin to examine how these components interact during transport, chemical cross-linking was performed on intact chloroplasts containing precursor proteins trapped at a particular stage of transport by ATP limitation. Large cross-linked complexes were observed using three different reversible homobifunctional cross-linkers. Three outer envelope membrane proteins (OEP86, OEP75, and OEP34) and one inner envelope membrane protein (IEP110), previously reported to be involved in protein import, were identified as components of these complexes. In addition to these membrane proteins, a stromal member of the hsp100 family, ClpC, was also present in the complexes. We propose that ClpC functions as a molecular chaperone, cooperating with other components to accomplish the transport of precursor proteins into chloroplasts. We also propose that each envelope membrane contains distinct translocation complexes and that a portion of these interact to form contact sites even in the absence of precursor proteins.

Stable association of chloroplastic precursors with protein translocation complexes that contain proteins from both envelope membranes and a stromal Hsp100 molecular chaperone

Cytoplasmically synthesized precursors interact with translocation components in both the outer and inner envelope membranes during transport into chloroplasts. Using co-immunoprecipitation techniques, with antibodies specific to known translocation components, we identified stable interactions between precursor proteins and their associated membrane translocation components in detergent-solubilized chloroplastic membrane fractions. Antibodies specific to the outer envelope translocation components OEP75 and OEP34, the inner envelope translocation component IEP110 and the stromal Hsp100, ClpC, specifically co-immunoprecipitated precursor proteins under limiting ATP conditions, a stage we have called docking. A portion of these same translocation components was co-immunoprecipitated as a complex, and could also be detected by co-sedimentation through a sucrose density gradient. ClpC was observed only in complexes with those precursors utilizing the general import apparatus, and its interaction with precursor-containing translocation complexes was destabilized by ATP. Finally, ClpC was co-immunoprecipitated with a portion of the translocation components of both outer and inner envelope membranes, even in the absence of added precursors. We discuss possible roles for stromal Hsp100 in protein import and mechanisms of precursor binding in chloroplasts.

Unilateral anomalous left common carotid artery; a case report

An anomaly of the left common carotid artery was observed in a Japanese male cadaver during an anatomy class at the Saitama Medical School in 1995. The superior thyroid, lingual and facial arteries arose from the common carotid artery, and the posterior auricular, maxillary and superficial temporal arteries arose from the common carotid artery by a common trunk. The occipital and ascending pharyngeal arteries arose from the internal carotid artery. The left carotid body (glomus caroticum) was observed to be slightly below the lingual artery, behind the common carotid artery, and it was located at the level of the intervertebral disk between C2 and C3 or at the same level as the right carotid body. The carotid body was richly innervated by a branch of the glossopharyngeal nerve and by a plexus of sympathetic fibers from the vagus and glossopharyngeal nerves. We assumed that the artery above the level of the carotid body was the internal carotid artery; there was no specific external carotid artery and all branches of the external carotid artery arose from the internal carotid artery.

Ultrastructure of the lamina propria of the human vocal fold

We studied three-dimensional arrangement of collagen fibers and elastic fibers in the human vocal fold by scanning electron microscopy after digesting cellular elements and collagen fibers with formic acid treatment and cellular elements and elastic fibers with 10% sodium hydroxide. The superficial layer consisted of clusters of collagen fibers and fine elastic fibers running straight or coiled. The intermediate layer consisted of thick bundles of collagen and elastic fibers running longitudinally and fine coiled elastic fibers. The deep layer consisted of coil elastic fibers and dense collagen bundles. Collagen fibers may have a role of maintaining the organization of vocal folds even during vibration, and elastic fibers act to rapidly restore the vocal folds to their original form. We also studied the distribution of oxytalan fibers in vocal folds by aldehyde-fucusin staining. Oxytalan fibers were distributed throughout the connective tissue of the vocal folds, and a large number of fibers was present just under the epithelial basement membrane and around the muscle fibers. If these fibers are damaged and lose their functions, vibration of the vocal folds will be impaired.

Topology of IEP110, a component of the chloroplastic protein import machinery present in the inner envelope membrane

Proteins from both the inner and outer envelope membranes are engaged in the recognition and translocation of precursor proteins into chloroplasts. A 110 kDa protein of the chloroplastic inner envelope membrane was identified as a component of the protein import apparatus by two methods. First, this protein was part of a 600 kDa complex generated by cross-linking of precursors trapped in the translocation process. Second, solubilization with detergents of chloroplasts containing trapped precursors resulted in the identification of a complex containing both radiolabeled precursor and IEP110. Trypsin treatment of intact purified chloroplasts was used to study the topology of IEP110. The protease treatment left the inner membrane intact while simultaneously degrading domains of inner envelope proteins exposed to the intermembrane space. About 90 kDa of IEP110 was proteolitically removed, indicating that large portions protrude into the intermembrane space. Hydropathy analysis of the protein sequence deduced from the isolated cDNA clone in addition to Western blot analysis using an antiserum of IEP110 specific to the N-terminal 20 kDa, suggests that the N-terminus serves to anchor the protein in the membrane. We speculate that IEP110 could be involved in the formation of translocation contact sites due to its specific topology.

The necessity of adjusting the dosage of zonisamide when coadministered with other anti-epileptic drugs

Zonisamide (ZNS), a new anti-epileptic drug that exhibits a wide anti-epileptic spectrum, is commonly prescribed concomitantly with other anti-epileptic drugs. The interaction between ZNS and other anti-epileptic drugs was investigated in epileptic patients. The steady state plasma levels of all the anti-epileptic drugs were measured by high-performance liquid chromatography. The concomitant administration of phenobarbital (PB), phenytoin (PHT), or carbamazepine (CBZ) with ZNS significantly decreased the ratio of the steady state plasma concentration to the administered dose (C/D ratio) of ZNS, whereas clonazepam (CZP) and valproic acid (VPA) when administered concomitantly with ZNS did not change the C/D ratio. Significant negative correlations were observed between the C/D ratio of ZNS and the doses of PB, PHT, CBZ, and VPA. On the other hand, the ratio of the plasma concentration of carbamazepine-10,11-epoxide (CBZ-E), the major active metabolite of CBZ, to the plasma concentration of CBZ was significantly decreased by concomitant administration with ZNS, indicating that ZNS inhibits the metabolism of CBZ. These findings show that when ZNS is administered concomitantly with these anti-epileptic drugs, it is necessary to monitor the plasma concentration of ZNS in order to adjust its dosage.

The interaction between pindolol and epinephrine contained in local anesthetic solution to the left ventricular diastolic filling velocity in normal subjects

To evaluate the interaction between the nonselective beta-blocker, pindolol, and epinephrine contained in a local anesthetic solution, the left ventricular diastolic filling velocity was examined with pulsed Doppler echocardiography. Arterial blood pressure (BP), the R-R interval on the electrocardiogram (RR), and Doppler echo-cardiographic measurements were recorded in seven healthy volunteers after 45 micrograms of epinephrine contained in lidocaine (L-E) was injected in the maxilla after pretreatment with 5 mg of pindolol. The administration of L-E caused the elevation of BP and an increase in RR interval. Peak early (E) and peak atrial (A) filling velocities decreased, whereas isovolumic relaxation time (IVRT) and diastolic filling period (DFP) were prolonged. Although the ratio of E to A (E/A) remained unchanged, E/A/DFP was reduced. In contrast, when L-E was given without pindolol pretreatment, RR interval was shortened and BP was unchanged. The increase of both E and A velocities and the shortening of both IVRT and DFP were observed. E/A remained unchanged but E/A/DFP was increased. These results suggested that L-E caused opposite effects on the left ventricular filling velocity in the presence or absence of pindolol. We conclude that epinephrine activates the left ventricular relaxation rate but impairs it in the presence of pindolol.

Pharmaceutical evaluation of carbamazepine suppositories in rats

The absorption of carbamazepine (CBZ) after rectal administration in the form of a suppository was studied in rats. CBZ suppositories were prepared with Witepsol H-15 (H-15), Witepsol S-55 (S-55) or polyethylene glycol 6000 (PEG) bases by moulding procedure. An in vitro investigation was undertaken using a dissolution apparatus. The in vitro dissolution rate of CBZ showed marked differences among the bases in the order PEG > H-15 > S-55. An in vivo study demonstrated marked differences in the time required to reach peak plasma concentration (Tmax) of CBZ after rectal and oral administration: the absorption of CBZ from PEG base was the most prolonged among these bases (in the order PEG > H-15 > S-55 > ORAL). Comparison of the area under the plasma concentration-time curve (AUC) of CBZ after rectal administration of the three different suppositories with those after intravenous and oral administration showed no significant differences in the AUC among the five preparations. These results suggest the possibility that CBZ suppositories can replace oral treatment for epilepsy.

Recurrent hemangiopericytoma of the liver: report of a case

We present herein the case of a 63-year-old man with a locally recurrent hemangiopericytoma in the hepatic hilum. The patient presented to our hospital for the investigation of elevated transaminases 6 years after undergoing resection of a hemangiopericytoma followed by chemotherapy at another hospital. Various imaging techniques demonstrated a well-circumscribed, hypervascular tumor with central necrosis in the hepatic hilum. Establishing a preoperative diagnosis would have been difficult without the information that he had previously had a hemangiopericytoma of the abdominal cavity. An extended right hepatic lobectomy was performed and histopathological examination confirmed the diagnosis of recurrent hemangiopericytoma. Although hemangiopericytoma is a rare tumor, the clinical presentation and radiologic features of this case were fairly typical.

Basement membrane formation of fetal mouse intestinal epithelial cells in organoid cultures

Basement membrane formation of fetal mouse intestinal epithelial cells was investigated in organoid cultures. Intestinal cells were dissociated with a commercial collagenase/dispase preparation, and the cells were grown at high density on a membrane filter at the interface between the medium and air. This type of culture allows the histotypical reorganization of cells. After 2 days in culture, epithelial cells began to accumulate on the surface, in particular the periphery of the culture. These cells were usually cuboid, and small vesicles were formed in the center of the culture. Laminin-positive material was observed at peripheral sites. However, no basement membrane could be identified beneath the epithelial cells at the electron-microscopic level. After 3 days, epithelial cells that had gathered at the periphery became columnar in shape. Laminin-positive material extended across the surface of the culture. However, the vesicles formed in the center of the culture were not associated with laminin-positive material. Basement membrane was observed by electron microscopy at some sites beneath groups of epithelial cells, but did not extend continuously beneath these cells. Some epithelial cells made contact with the underlying mesenchymal cells through the discontinuous basement membrane via intercellular contacts. After 5-6 days, the surface of the culture was almost completely covered with epithelial cells and, at some sites, villus-like structures were visible. Laminin-positive material was clearly detectable under epithelial cells, as well as around epithelial vesicles located in the center of the culture. By electron microscopy, basement membrane was clearly visible between the epithelial and mesenchymal cells. After 9 days, villus-like structures were rarely observed. After 3 weeks, the cell mass had become smaller and villi had disappeared. Basement membrane was extensively folded and no basement membrane was visible at some sites. Formation of basement membrane by epithelial cells in monolayer culture occurs in an incomplete and irregular manner. It occurs rapidly in organoid cultures that include mesenchyme and epithelium. The organoid culture used here should be a useful tool for studies of the formation and degeneration of the basement membrane as well as interactions between the epithelium and mesenchyme.

[The measurement of insulin antibodies and insulin autoantibodies by enzyme-linked immunosorbent assay using recombinant human insulin antigen and its clinical application]

Insulin antibodies (IA) are detectable in the sera of most insulin-treated patients with diabetes mellitus. Antibodies to exogenous insulin sometimes cause clinical symptoms of insulin resistance, allergy, and local lipoatrophy. Although the frequency of these complications has diminished with the use of highly purified porcine insulin or recombinant human insulin, there are some patients with high titer of IA. Autoantibodies to insulin (IAA) are also described. IAA has been reported to be in association with both insulin-dependent diabetes mellitus (IDDM) and polyendocrine autoimmune disease. For many years these antibodies have been measured by radiobinding assay (RBA) in which the complexes are precipitated non-specifically by polyethylene glycol. In the present study we developed a rapid and quantitative enzyme-linked immunosorbent assay (ELISA) method for measuring IA and IAA using recombinant human insulin antigen. We applied this method to the samples obtained from patients with diabetes mellitus and autoimmune thyroid disease and then compared the results with those obtained from the RBA method. The calibration curve for ELISA was derived from the dilution curve of a single serum from a patient positive for insulin antibody, and the results were expressed arbitrarily as ELISA UNIT. The calibration curve was approximately linear on the log-log scale within the range of 0.1-2.0 at optical density (OD)450nm, (6.25-200 ELISA UNIT). The intra-assay (CV = 2.3-3.1%) and inter-assay (CV = 2.8-7.2%) precisions were acceptable. Recovery rate varied from 74.5% to 118.5% and dilution experiments showed good linearity. Specificity was demonstrated by substituting purified human IgG for the test serum and glucagon for insulin. Except for hemoglobin, coexisting substances in serum had almost no effect on ELISA. The range of ELISA UNIT (Mean +/- SD) of 83 normal sera was 12.7 +/- 4.6. Positivity for IA by ELISA (> normal Mean + 3SD) was 11 out of 58 (19.0%) and 26 out of 55 (47.3%) in patients with IDDM and with non-insulin-dependent diabetes mellitus (NIDDM) who were treated with insulin, respectively. Positivity for IAA by ELISA was 5 out of 173 (2.8%) and 1 out of 20 (5.0%) in patients with NIDDM without insulin therapy and hyperthyroidism due to Graves' disease, respectively. However, by RBA, we detected 4 other cases positive for IAA in NIDDM without insulin therapy and one case in Graves' disease. The present study demonstrates that the newly developed method of ELISA using recombinant human insulin antigen is clinically useful for measuring IA and IAA.

Mass propagation of shoots of Stevia rebaudiana using a large scale bioreactor

A procedure for the mass propagation of multiple shoots of Stevia rebaudiana is described. Isolated shoot primordia were used as the inoculum to obtain clusters of shoot primordia. Such clusters were grown in a 500 liter bioreactor to obtain shoots. A total of 64.6 Kg of shoots were propagated from 460 g of the inoculated shoot primordia. These shoots were easily acclimatized in soil.

Changes associated with the basal lamina during metamorphosis of Xenopus laevis

We examined the changes in the morphology of the basal lamina of the colon, abdominal wall and tail muscles of tadpoles during metamorphosis and compared our results to those previously obtained for the small intestine. At the early stage of metamorphic climax (stages 60-62), we observed a curving of the basal lamina along the processes of the epithelial cells. At a later stage of metamorphic climax (stages 63-66), more extensive curving and folding of the basal lamina were observed. The basal lamina of the mesothelial cells in the abdominal wall did not change extensively as compared to the colon. Folded basal lamina was observed among degenerated muscle cells. Our results suggest that the folding of the basal lamina depends on the degree of deformation of the particular organ, which occurs mainly by physical factors such as the shortening or shrinking of the organ due to cellular degeneration. Cells that are newly differentiated produce an additional basal lamina, which results in transient doubling or layering. The combination of physical factors and cell differentiation results in a basal lamina that is more complex and contains folds and layers.

Stimulation of potato (Solanum tuberosum L.) tuberization by semicontinuous liquid medium surface level control

A procedure for the mass propagation of potato (Solanum tuberosum L.) tubers using a laboratory scale jar fermentor is described. Tuberization was clearly suppressed when the shoots were completely submerged in the liquid medium. Tubers were mainly formed at the medium surface. When shoots were cultured by the semi-continuous medium surface level control method, in which the medium surface level was raised or lowered throughout the culture period, tubers were induced and developed in every area in the jar fermentor. Tubers propagated by this method contained about 18 % (w/w) dry matter, slightly less than in field grown tubers, but most of the tubers weighing more than 0.2 g(FW) sprouted under room condition, without any acclimatization, during 3 month after the culture.

Phenotypic modulation and elastin formation of cultured aortic smooth muscle cells grown on and within collagen gels

Aortic smooth muscle cells (SMC) were grown on and within collagen gels and their phenotype and elastin formation were examined. Cells grown on the gels showed multilayer growth with nodule formation. They contained many ribosomes and microfilament bundles with dense bodies. In contrast, cells grown within collagen gels did not form nodules. When collagen gels containing SMC were manually detached from the culture dish, the cells were found to be of the synthetic phenotype with well-developed rough endoplasmic reticulum (ER) and Golgi complexes, but few microfilament bundles. There were numerous elastin deposits in the intercellular spaces. Our findings suggest that the physical property of the substrate affects the phenotype and function of the SMC.

Cell shape and arrangement of cultured aortic smooth muscle cells grown on collagen gels

Aortic smooth muscle cells (SMC) grown on conventional plastic culture dishes have morphological and functional properties of dedifferentiated cells in subculture. We examined the influence of collagen gels on the cell shape and arrangement. The cells grown on collagen gels showed a multilayered growth with formation of nodules. When the edge of the collagen gels was detached from the culture dish, the shape and arrangement of cells on the edge differed from that of the central, still attached region. The cells grown on floating collagen gels exhibited a spindle-like shape and were arranged in concentric circles. These findings suggest that the physical property of the substrate influences the cell shape and arrangement.