Synthesis of C-ring aromatic taxoids and evaluation of their multi-drug resistance reversing activity

The C-aromatic taxoids were synthesized to develop effective inhibitors against drug efflux mediated by p-glycoproteins. Among those tested using multi-drug resistant tumor cells (2780AD), the benzoate 11 exhibited significant activity as potent as verapamil, a well-established MDR reversing agent.

Synthesis and evaluation of artificial taxoids with antitumor and multi-drug resistance reversing activities

Artificial taxoids were synthesized and subjected to evaluation of their ability of multi-drug resistance reversing and antitumor activities. While the taxoid 4 could not increase cellular accumulation of vincristine in multi-drug resistant tumor cells, the C4-hydroxy analog 15 showed significant effect. However, these compounds showed weak activities on growth inhibition of cancer cells.

Prospective echocardiographic analysis of progressive obstruction of the proximal pulmonary artery in congenital heart disease and obstructed pulmonary flow

BACKGROUND

It is uncertain whether proximal pulmonary artery (PA) obstruction exists soon after birth and whether its progress relates directly to postnatal ductal constriction in congenital heart disease and obstructed pulmonary flow.

METHODS

Serial morphometric analyses of the PA branches by echocardiogram were performed in 28 patients (mean age at initial study 2.5 days) until severe constriction of the ductus occurred (mean age 47 days). These patients were divided into 2 groups by subsequent angiographic or postmortem confirmation; 10 with proximal PA obstruction (group 1) and 18 without obstruction (group 2).

RESULTS

At the time of initial examination, the mean indexed diameter of the proximal PA on the side of the ductus arteriosus in group 1 was significantly smaller than that on the contralateral side (5.2+/-0.7 versus 9.0+/-0.7 mm/BSA0.5, P < .001) or that in group 2 (8.0+/-0.4 mm/BSA0.5, P < .001). In group 1, 8 patients had a proximal PA index on the ductal side < or = 5.5 mm/BSA0.5, which was less than those of any group 2 patients. After severe constriction of the ductus, the proximal PA index on the ductal side further decreased only in group 1 (P < .01).

CONCLUSIONS

These data indicate that unilateral obstructive lesion of branch PA is present shortly after birth and its progression relates directly to ductal constriction. Neonates with branch PA obstruction can be identified on their initial echocardiogram as having a proximal PA index on the ductal side < or = 5.5 mm/BSA0.5.

Basal cell carcinoma cells resemble follicular matrix cells rather than follicular bulge cells: immunohistochemical and ultrastructural comparative studies

To detail the histogenetic relationship between basal cell carcinoma (BCC) and hair follicles, we immunohistochemically compared BCC cells to follicular matrix cells and follicular bulge cells using a panel of monoclonal antibodies against melanocytes, cytokeratins, subepidermal extracellular matrix components, and bullous pemphigoid (BP) sera, as well as using electron microscopy. Cytokeratin expression patterns were not consistent with the variety in types of cytokeratins and in cases of BCC. The distribution of some extracellular matrix components was not only linear along the interfaces of BCC tumor nests and stroma, and follicular matrix and follicular papilla; granular deposits were also seen in the stroma and follicular papilla, whereas they were only linearly distributed along the follicular bulge. The BP antigens and integrin alpha 6, which were absent in BCC and follicular matrix, were expressed in the follicular bulge area. Electron microscopically, hemidesmosomes were poorly organized in these three tissues, but the lamina densa was incomplete in BCC and follicular matrix, whereas the lamina densa in the follicular bulge area was continuous. These morphologic similarities between BCC and follicular matrix cells, and coexistence of melanocytes in the BCC tumor nest strongly suggest the differentiation of BCC toward the follicular matrix cells.

Drug eruption due to Bufferin showing erythema exsudativum multiforme with a photo-recall-like phenomenon

A 21-year-old woman who had been taking several kinds of analgesics to treat dysmenorrhea developed episodic attacks of a purpuric macular eruption and a burning sensation on unexposed areas of the upper chest and back where she had sustained severe sunburn eight months earlier. Target-like lesions developed on these areas after intake of Bufferin, a combination of aspirin and dialuminate. After the eruptions had abated following systemic administration of a corticosteroid agent, a challenge test was performed, using a quarter of a tablet of Bufferin. The patient developed a temporary burning sensation and a erythematous color on the previously sunburned skin. We diagnosed this case as a drug eruption due to Bufferin showing erythema exsudativium multiforme with a photo-recall-like phenomenon. In our case, skin tests would be useful to confirm the causal drug.

Effect of suture closure of coronary artery fistula on aneurysmal coronary artery and myocardial ischemia

This study indicates the importance of coronary angiography and myocardial scintigraphy on long-term follow-up of patients after surgery for coronary arterial fistula in view of the progression to coronary artery obstruction and myocardial ischemia.

Successful prenatal exclusion of an unspecified subtype of severe epidermolysis bullosa

BACKGROUND

In most cases of prenatal diagnosis of epidermolysis bullosa (EB), the subtype of severe EB from which the fetus is at risk is identified by studying the specimens of the proband. In this study, the parents of a child with an unspecified subtype of severe EB sought prenatal diagnosis for their second and third pregnancies.

METHODS

The firstborn of a couple (the proband) suffered generalized blistering and erosions of the skin present from delivery, and died on the 11th postnatal day of severe EB of an unspecified type. The only diagnostic specimen available from the first infant was a conventionally stained skin section for light microscopy that showed the dermo-epidermal separation. For prenatal diagnosis in the second and third pregnancies, fetal skin biopsies were performed at 19 weeks of gestation.

RESULTS

In both cases, fetal skin showed no ultrastructural abnormalities and no evidence of dermo-epidermal separation. Indirect immunofluorescence was positive for monoclonal antibodies against type VII collagen, laminin 5, uncein, alpha6 and beta4 integrins, BPAG2, and HD1/plectin, which are known to be reduced or absent in specific subsets of severe EB. The pregnancies were therefore continued, and normal healthy second and third children were delivered.

CONCLUSIONS

Fetal skin biopsy, together with a panel of newly developed monoclonal antibodies, provided reliable prenatal diagnosis in the present family in which preliminary information of the EB proband was limited.

[Color Doppler signal enhancement with SH/TH-508 in pancreatic tumors]

In this report, we showed the efficacy of a new contrast agent (SH/TA-508, Schering AG, Germany) for color Doppler imaging of the pancreatic tumors. In pancreatic ductal cancer, no enhancement of the lesion was observed, but vascular invasion by cancer became to be easily evaluated. On the other hand, hypervascular tumors such as islet cell tumor and cystadenocarcinoma, were increased in color Doppler signals of vessels by SH/TA-508. We concluded that SH/TA-508 was useful for evaluating the vascular invasion by pancreatic cancer as well as vascularity of hypervascular mass and solid component of cystic neoplasma.

Pasteurella multocida toxin and Bordetella bronchiseptica dermonecrotizing toxin elicit similar effects on cultured cells by different mechanisms

We compared the effects of Pasteurella multocida toxin (PMT) with Bordetella bronchiseptica dermonecrotizing toxin (DNT) at a cellular level under same conditions. Both PMT and DNT cause actin stress fiber formation in MC3T3-E1 cells which is known to be regulated by the small GTP-binding protein Rho. DNT induced mobility shifts of Rho on SDS-polyacrylamide gel electrophoresis, indicating direct modification as reported elsewhere. In contrast, no alternations in the electrophoretic mobility of Rho were found in lysates from PMT-treated cells. PMT but not DNT increased the intracellular level of inositol phosphates, indicating the elevation of phospholipase C (PLC) activity in the PMT-treated cells. These results indicate that PMT does not have Rho as a target but activates PLC. The formation of actin stress fiber by PMT seems to be stimulated through the indirect activation of Rho, which resides downstream of PLC, PMT and DNT seem to elicit similar toxic effects, at least in part, through the activation of Rho.

Establishment and characterization of a novel in vitro angiogenesis model using a microvascular endothelial cell line, F-2C, cultured in chemically defined medium

The behavior of vascular endothelial cells (EC) is an important factor in the processes involved in angiogenesis, but the regulatory mechanisms of angiogenesis, especially underlying the tubulogenesis by EC are not yet clear. Although a number of in vitro experimental models of tubulogenesis have been developed by use of cultured EC, most of those models are too complex to be easily handled and further, the culture media are usually supplemented with serum, creating problems in interpretation of experimental results. To generate a simple in vitro angiogenesis study model under serum-free culture conditions, we adapted a murine microvascular endothelial cell line, F-2, to a chemically defined medium, Cos Medium 001, and successfully established a subline of F-2, designated F-2C, which revealed a unique growth pattern. In Cos Medium 001, F-2C proliferates in a cobblestone pattern at an early growth stage, but, at a late growth stage, spontaneously differentiates to form three-dimensional honeycomblike tubular structures without the supplementation of any specific factors. The cell aggregation activity of F-2C in the presence of Ca2+ was much greater than that of F-2. The amount of subendothelial matrix deposited by F-2C was significantly higher than that by F-2, and increased prominently after the F-2C cells reached the differentiating stage of tubulogenesis. These findings indicate that F-2C is a new EC line in which tubulogenesis is spontaneously induced by the marked deposition of basement membrane analog to the subendothelial matrix and by the enhancement of presumable cadherin activity. We suggest that this cell line, F-2C, represents a simple and useful in vitro angiogenesis model.

Clostridium perfringens enterotoxin utilizes two structurally related membrane proteins as functional receptors in vivo

Human and mouse cDNAs showing homology to the Clostridium perfringens enterotoxin (CPE) receptor gene (CPE-R) from Vero cells (DDBJ/EMBL/GenBankTM accession no. D88492) (Katahira, J., Inoue, N., Horiguchi, Y., Matsuda, M., and Sugimoto, N. (1997) J. Cell Biol. 136, 1239-1247) were cloned. They were classified into two groups, the Vero cell CPE receptor homologues and rat androgen withdrawal apoptosis protein (RVP1; accession no. M74067) homologues, based on the similarities of primary amino acid sequences. L929 cells that were originally insensitive to CPE became sensitive to CPE on their transfection with cDNAs encoding either the CPE receptor or RVP1 homologues, indicating that these gene products are not only structurally similar but also functionally active as receptors for CPE. By binding assay, the human RVP1 homologue showed differences in affinity and capacity of binding from those of the human CPE receptor. Northern blot analysis showed that mouse homologues of the CPE receptor and RVP1 are expressed abundantly in mouse small intestine. The expression of CPE-R mRNA in the small intestine was restricted to cryptic enterocytes, indicating that the CPE receptor is expressed in intestinal epithelial cells. These results are consistent with reports that CPE binds to the small intestinal cells via two different kinds of receptors. High levels of expression of CPE-R and/or RVP1 mRNA were also detected in other organs, including the lungs, liver, and kidneys, but only low levels were expressed in heart and skeletal muscles. These results indicate that CPE uses structurally related cellular proteins as functional receptors in vivo and that organs that have not so far been recognized as CPE-sensitive have the potential to be targets of CPE.

Bordetella bronchiseptica dermonecrotizing toxin induces reorganization of actin stress fibers through deamidation of Gln-63 of the GTP-binding protein Rho

Bordetella dermonecrotizing toxin causes assembly of actin stress fibers and focal adhesions in some cultured cells and induces mobility shifts of the small GTP-binding protein Rho on electrophoresis. We attempted to clarify the molecular basis of the toxin action on Rho. Analysis of the amino acid sequence of toxin-treated RhoA revealed the deamidation of Gln-63 to Glu. The substitution of Glu for Gln-63 of RhoA by site-directed mutagenesis caused a mobility shift on electrophoresis, which was indistinguishable from that of the toxin-treated RhoA. Neither mutant RhoA-bearing Glu-63 nor toxin-treated RhoA significantly differed from untreated wild type RhoA in guanosine 5'-[gamma-thio]triphosphate binding activity but both showed a 10-fold reduction in GTP hydrolysis activity relative to untreated RhoA. C3H10T1/2 cells transfected with cDNA of the mutant RhoA bearing Glu-63 showed extensive formation of actin stress fibers similar to the toxin-treated cells. These results indicate that the toxin catalyzes deamidation of Gln-63 of Rho and renders it constitutively active, leading to formation of actin stress fibers.

Three-dimensional cultures of keratinocytes and an application to in vitro-amyloid production of cutaneous amyloidosis

Some three-dimensional culture models of the skin were reviewed including our systems using a collagen dermal substitute and a matrix dermal substitute. No obvious junctional structures, such as hemidesmosomes and the lamina densa, were formed between the basal keratinocytes and the dermal substitutes, when the cytoplasmic membrane of the basal keratinocytes directly faced the collagenous materials. On the other hand, when the cytoplasmic membrane of the basal keratinocytes faced the preformed basement membrane, the type IV collagen film, or the extracellular matrix gel, an organized interaction occurred between the basal keratinocytes and the dermal substitute through hemidesmosomes and a rudimentary lamina densa. Keratinocyte differentiation in the suprabasal layers seemed to be closely related to such a basal cell differentiation. Our preliminary examination of the experimental amyloid production by the epidermal sheet from the lesional skin of patients with primary localized cutaneous amyloidosis suggested that the basal cells in the transplanted lesional epidermis produced amyloid fibrils in our in vitro culture model. This is another use of the three-dimensional culture models of the skin in addition to the application of the systems to wound treatment.

Roles of E- and P-cadherin in the human skin

The Ca(2+)-dependent cell-cell adhesion molecules, termed cadherins, are subdivided into several subclasses. E (epithelial)- and P (placental)-cadherins are involved in the selective adhesion of epidermal cells. E-cadherin is expressed on the cell surfaces of all epidermal layers and P-cadherin is expressed only on the surfaces of basal cells. Ultrastructural studies have shown that E-cadherin is distributed on the plasma membranes of keratinocytes with a condensation in the intercellular space of the desmosomes. During human skin development P-cadherin expression is spatiotemporally controlled and closely related to the segregation of basal layers as well as to the arrangement of epidermal cells into eccrine ducts. In human skin diseases E-cadherin expression is markedly reduced on the acantholytic cells of tissues in pemphigus and Darier's disease. Cell adhesion molecules are now considered to play a significant role in the cellular connections of cancer and metastatic cells. Reduced expression of E-cadherin on invasive neoplastic cells has been demonstrated for cancers of the stomach, liver, breast, and several other organs. This reduced or unstable expression of E- and P-cadherin is observed in squamous cell carcinoma, malignant melanoma, and Paget's disease, but cadherin expression is conserved in basal cell carcinoma. Keratinocytes cultured in high calcium produce much more intense immunofluorescence of intercellular E- and P-cadherin than those cells grown in low calcium. E-cadherins on the plasma membrane of the keratinocytes are shifted to desmosomes under physiological conditions, and therein may express an adhesion function in association with other desmosomal cadherins. Soluble E-cadherins in sera are elevated in various skin diseases including bullous pemphigoid, pemphigus vulgaris, and psoriasis, but not in patients with burns. Markedly high levels in soluble E-cadherin are demonstrated in patients with metastatic cancers.

In vivo evidence of the critical role of cadherin-5 in murine vascular integrity

Vascular endothelial cell-cell adhesion is crucial for the regulation of vascular functions and is associated with many circulatory disorders. We isolated a rat monoclonal antibody (VECD1) recognizing the mouse vascular endothelial cell adhesion molecule and found that it inhibited vascular endothelial cell-cell association. We sequenced a full-length cDNA of the antigen that was identical to mouse cadherin-5. L-cells transfected with its cDNA acquired cell-cell adhesiveness, and these transfectants reacted with VECD1 at cell-cell contact areas. We studied the role of mouse cadherin-5 in vascular functions. The addition of VECD1 antibody to a cultured vascular endothelial cell line (F-2) caused the detachment of each cell. Although normal F-2 cells formed tubular structures on Matrigel, VECD1 disturbed the tubulogenesis. VECD1 also increased the permeability through the F-2 cell layer. To clarify the in vivo function of mouse cadherin-5, we intraperitoneally injected the hybridomas producing VECD1 into adult mice. Severe venous stasis and subcutaneous hemorrhage were induced within several days after the injection, resulting in the early death of the animals. These findings are evidence of an essential role of cadherin-5 in the regulation of vascular endothelial cell-cell adhesion in vivo.

Botulinolysin, a thiol-activated hemolysin produced by Clostridium botulinum, inhibits endothelium-dependent relaxation of rat aortic ring

The effects of botulinolysin (Blyn), a thiol-activated hemolysin produced by Clostridium botulinum, on contractility of rat aortic ring were studied in order to clarify an underlying mechanism of vasoconstriction by the toxin observed previously as an increase in perfusion pressure in isolated rat organs. Blyn (30 hemolytic units/ml; HU/ml) itself did not elicit any apparent change in resting tension of the ring. Contractile tension elicited by a high concentration of phenylephrine in endothelium-intact rings increased significantly after treatment with Blyn (30 HU/ml), while phenylephrine-induced contraction of endothelium-denuded rings was not influenced by toxin treatment. In rings with intact endothelium, acetylcholine (ACh)-induced relaxation was significantly inhibited after treatment with Blyn (30, 10, 1 HU/ml). In contrast, relaxation of denuded rings by sodium nitroprusside was not affected by toxin treatment (30 HU/ml). Arginine (10(-4) M) partly reversed the inhibition of ACh-induced relaxation by the toxin (1 HU/ml). Endothelium-dependent relaxation by histamine or adenosine triphosphate was also inhibited by Blyn (1 HU/ml), but the relaxation elicited by calcium ionophore A23187 was not influenced by the toxin. The results indicate that Blyn acts on endothelium and inhibits agonist-induced endothelium-dependent relaxation of blood vessels.

Mosaic expression of uncein and 180-kDa bullous pemphigoid antigen in generalized atrophic benign epidermolysis bullosa

Immunofluorescence microscopy of epidermodermal junction components in serial cryosections from the perilesional skin of a patient with generalized atrophic benign epidermolysis bullosa (GABEB) showed broken line-like staining of both BPAG2 (180-kDa bullous pemphigoid antigen) and uncein (antigen of 19-DEJ-1 monoclonal antibody), whereas integrin alpha 6 and laminin 5 were continuously expressed along the basement membrane zone. Immunoelectron microscopy revealed a mosaic distribution of the BPAG2/uncein positive and negative cells. BPAG2, a candidate protein of GABEB, probably has a close connection with uncein, and anchoring filament component.

Foot ulcer due to arteriovenous malformation: report of a case

A 41-year-old woman had erosive eruptions surrounded by irregularly shaped pigmentation on the lateral aspect of her right foot, where she had noted gradually increasing warmth and pain for 10 years. The eruptions waxed and waned without complete healing, and an ulcer which had formed one year previously did not respond to topical treatments. Arteriography performed on the right lower extremity disclosed multiple diffuse arteriovenous malformations in the right lower leg and foot. The ulcer was treated by bed rest, surgical debridement, and topical application of bucladesine sodium ointment. After three months, the ulcer healed, leaving a shallow scar and pigmentation.

Molecular cloning and functional characterization of the receptor for Clostridium perfringens enterotoxin

A cDNA encoding the Clostridium perfringens enterotoxin receptor gene (CPE-R) was cloned from an expression library of enterotoxin-sensitive Vero cells. The nucleotide sequence of CPE-R showed that the enterotoxin receptor consists of 209 amino acids with a calculated molecular mass of 22,029 D. This receptor is highly hydrophobic, contains four putative transmembrane segments, and has significant similarity to the rat androgen withdrawal apoptosis protein RVP1 and the mouse oligodendrocyte specific protein, the functions of which are unknown. The expression of CPE-R was detected in the enterotoxin-sensitive Vero, Hep3B, and Intestine 407 cell lines, but not in the enterotoxin-insensitive K562 and JY cell lines. The CPE-R gene product expressed in enterotoxin-resistant L929 cells bound to enterotoxin specifically and directly and with high affinity and rendered the cells sensitive to the toxin, indicating that the cloned receptor is functional. Results showed that enterotoxin could not assemble into a complex with a defined structure unless it interacted with the receptor. From these results, it is proposed that the enterotoxin receptor is required for both target cell recognition and pore formation in the cell membrane.

Bordetella bronchiseptica dermonecrotizing toxin, which activates a small GTP-binding protein rho, induces membrane organelle proliferation and caveolae formation

We recently demonstrated that Bordetella bronchiseptica dermonecrotizing toxin (DNT) modifies a small GTP-binding protein rho and causes assembly of actin stress fibers and focal adhesions in MC3T3-E1 cells, indicating that DNT activates the function of rho protein (Horiguchi et al., 1995, J. Cell Sci. 108, 3243-3251). In this study, we examined by electron microscopy ultrastructural changes in DNT-treated MC3T3-E1 cells under conditions in which DNT elicited the above morphological changes. We found that DNT induced proliferation of cytoplasmic membrane organelles, such as Golgi apparatus, smooth and rough endoplasmic reticulum, and mitochondria, and formation of plasmalemmal caveolae. Therefore we examined also the effect of Clostridium botulinum C3 exoenzyme (C3), which has been known to ADP-ribosylate and inactivate rho protein, and found that C3 exoenzyme inhibited the development of membrane organelles in the MC3T3-E1 cells. These findings show that proliferation of membrane organelles and caveolae formation are controlled by the function of rho, which is the target of DNT action.

Intraductal papillary adenocarcinoma with mucin hypersecretion and coexistent invasive ductal carcinoma of the pancreas with apparent topographic separation

We report a 66-year-old man who had a cystic intraductal papillary adenocarcinoma containing a papillary adenoma, in the head of the pancreas and a coexistent invasive, well differentiated solid tubular adenocarcinoma in the tail of the pancreas. He was hospitalized with acute epigastralgia. Computed tomography demonstrated a multilocular cystic mass in the head of the pancreas and a solid tumor in the tail. Endoscopic retrograde pancreatography showed mucin secretion from an enlarged papilla of Vater, marked dilatation of the main pancreatic duct in the head and body, cystic dilatation of the uncinate branch, and irregular narrowing of the main pancreatic duct in the tail. Total pancreatectomy was performed. Between the cystic tumor and the solid tumor there was a distance of 4.8 cm of normal pancreatic parenchyma and duct, recognized both grossly and microscopically. The patient died 35 months after the operation. At autopsy, peritonitis carcinomatosa was found in the abdominal cavity. Microscopically, disseminated nodules were also well differentiated tubular adenocarcinoma. The apparent anatomic separation of these two tumors within the pancreas is extremely unusual.

Spontaneous autoimmune skin lesions of MRL/n mice: autoimmune disease-prone genetic background in relation to Fas-defect MRL/1pr mice

The autoimmune-prone MRL/Mp-lpr/lpr (MRL/lpr) mouse is characterized by the lpr mutation, which is a defect in the Fas antigen. Since Fas mediates apoptosis, this defect results in CD4-CD8- double negative T-cell proliferation, lupus nephritis, and macroscopic lupus erythematosus-like skin lesions. The control counterpart of MRL/lpr mouse is the MRL/Mp-+/+ (MRL/n) mouse, which lacks the lpr mutation and is almost normal during the first 6 mo of life. The lpr mutation, however, accelerates autoimmune phenomena in MRL/lpr mice. Thus, it is important to investigate autoimmune diseases like systemic lupus erythematosis in relation to the autoimmune disease-prone genetic background of MRL/n mice. We found that skin lesions in aged MRL/n mice had unique characteristics. The first characteristic is spontaneous occurrence, and the second is epidermal cell nuclear immunostaining with IgGs by direct immunofluorescence. The skin lesions in aged MRL/n mice showed milder inflammation than in MRL/lpr mice. A homogeneous pattern of epidermal cell nuclear staining was always associated with nuclear staining in kidney cells and also correlated with the in vitro binding of sera to keratinocytes cultured from newborn MRL/n mice. These results suggest that the skin lesions of aged MRL/n mice are a good model for certain types of cutaneous lupus erythematosus and also can provide new insights into the long-standing controversy whether epidermal cell nuclear staining occurs in vivo.